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NanoManufacturing

Michael De Volder, Engineering Department - IfM

Studying at Cambridge

Nanoscience News

Thu 04 Jun 12:00: Update on novel human astrovirus replication and disease

From All Talks (aka the CURE list). Published on Jan 26, 2020.

Update on novel human astrovirus replication and disease

Abstract not available

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Three-Dimensional Cavity-Coupled Metamaterials for Plasmonic Color and Real-time Colorimetric Biosensor

By Peimin Lu from RSC - Nanoscale latest articles. Published on Jan 26, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR10343K, Paper
Jia Zhu, Guanzhou Lin, Yun Huang, Kenan Zhang, Meizhang Wu, Wengang Wu, Peimin Lu
Plasmonic structure color has significant potential for visual biochemical sensing by simple instrumentation or even naked eye. Herein, we present a visual and real-time sensing strategy for refraction index sensing...
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Observation of non‐FCC Copper in Alkynyl‐Protected Cu53 Nanoclusters

By Mei Qu, Fu-Qiang Zhang, Dian-Hui Wang, Huan Li, Juan-Juan Hou, Xian-Ming Zhang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 25, 2020.

Despite the great effort, the only feasible access to non face‐centered cubic ( FCC ) copper is by physical vapor deposition under high vacuum. We report the first observation of non‐ FCC copper in a series of alkynyl protected Cu 53 nanoclusters (NCs) obtained from solution phase synthesis. Determined by single‐crystal X‐ray crystallography, the total structures of Cu 53 (C≡CPhPh) 9 (dppp) 6 Cl 3 (NO 3 ) 9 and its two derivatives reveal their most prominent feature: an ABABC stacking sequence involving 41 Cu atoms. It can be regarded as a mixed FCC and HCP structure, which gives strong evidence that Cu can be arranged in non‐ FCC lattice at ambient condition when proper ligands are provided. To gain a deeper understanding of the formation mechanism of Cu NCs, characterization methods including X‐ray absorption fine structure, XPS, ESI‐MS, UV‐vis, Auger spectroscopies and DFT calculations are carried out. It is revealed that Cu II successively coordinated with introduced ligands and changed to Cu I after bonding with phosphine. The following addition of NaBH 4 and the aging step further reduced it to the title NC. Their applications in homocoupling of phenylacetylene are also studied.

Divergent Synthesis of Vinyl−, Benzyl− and Borylsilanes through Aryl to Alkyl 1,5‐Palladium Migration/Coupling Sequences

By Dongbing Zhao, Jie-Lian Han, Ying Qin, Cheng-Wei Ju from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 25, 2020.

Organosilicon compounds have been extensively utilized both in industry and academy. Study on synthesis of diverse organosilanes is highly appealing. “Through‐space” metal/hydrogen shift allows functionalization of C−H bonds on a remote site that are otherwise difficult to achieve. However, until now, aryl to alkyl 1,5‐palladium migration process seems to have not been presented. We herein report remote olefination, arylation and borylation of methyl group on silicon to access diverse vinyl−, benzyl− and borylated silanes, which constitute the unique C( sp 3 )−H transformation based on a 1,5‐palladium migration process.

Stable pyrrole‐linked bioconjugates through tetrazine‐triggered azanorbornadiene fragmentation

By Enrique Gil de Montes, Alena Istrate, Claudio Navo, Ester Jiménez-Moreno, Emily Hoyt, Francisco Corzana, Inmaculada Robina, Gonzalo Jiménez-Osés, Antonio Moreno-Vargas, Gonçalo J. L. Bernardes from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 25, 2020.

We have developed an azanorbornadiene bromovinyl sulfone reagent that allows cysteine‐selective bioconjugation. Subsequent reaction with  dipyridyl tetrazine led to bond‐cleavage and formation of a pyrrole‐linked conjugate. The latter involves ligation of the tetrazine to the azanorbornadiene‐tagged protein through  inverse electron demand Diels–Alder cycloaddition  with subsequent double  retro ‐Diels–Alder reactions to form a stable pyrrole linkage. The sequence of site‐selective bioconjugation followed by bioorthogonal bond‐cleavage was efficiently employed for the labelling of three different proteins. This method benefits from easy preparation of these reagents, selectivity for cysteine, and stability after reaction with a commercial tetrazine, which lends it to the routine preparation of protein conjugates for chemical biology studies.

Tue 18 Feb 14:30: On some unlikely intersections for values and orbits of rational functions

From All Talks (aka the CURE list). Published on Jan 25, 2020.

On some unlikely intersections for values and orbits of rational functions

For given rational functions f_1, ... ,f_s defined over a number field K, Bombieri, Masser and Zannier (1999) proved that the algebraic numbers alpha for which the values f_1(alpha),... , f_s(alpha) are multiplicatively dependent are of bounded height (unless this is false for an obvious reason).

Motivated by this, we present recent finiteness results on multiplicative relations of values of rational functions at arguments restricted to the maximal abelian extension of K. We go even further and discuss the presence of multiplicative relations modulo finitely generated groups, posing some open questions. If time allows, we will present some finiteness results regarding the presence of powers of S-integers in orbits of polynomial dynamical systems.

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Environment‐Recognizing DNA Computation Circuit‐Controlled Intracellular Transport of Molecular Payloads for mRNA Imaging

By Wang Huihui, Tao Li, Pai Peng, Qiwei Wang, Yi Du, Zhijin Tian from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 25, 2020.

Programming intelligent DNA nanocarriers for targeted transport of molecular payloads (e.g. antisense oligonucleotides) in living cells has attracted extensive attentions. In vivo activation of these nanocarriers usually relies on external light irradiation. An emerging interest is to enable them to automatically recognize the intracellular surroundings and thereby be activated in situ under the logic control of programmed DNA computation circuits. Towards this goal, here we integrate DNA computation circuits with framework nucleic acid (FNA) nanocarriers that consist of a truncated square pyramid (TSP) cage and a built‐in duplex cargo containing an antisense strand of the target mRNA. An i‐motif and ATP aptamer embedded in TSP are employed as logic controlling units to respond to endogenous proton and ATP inside subcellular compartments, triggering the release of the sensing element for fluorescent mRNA imaging. Given the abnormal levels of extra‐/intracellular pH and ATP in tumor tissues, our logic‐controlled FNA devices are of benefit to target drug delivery and precise disease treatment.

High ethylene selectivity in methanol‐to‐olefin (MTO) reaction over MOR nanosheets

By Kun Lu, Ju Huang, Li Ren, Chao Li, Yejun Guan, Bingwen Hu, Hao Xu, Jingang Jiang, Yanhang Ma, Peng Wu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 25, 2020.

Precisely controlled crystal growth endows zeolites with special textural and catalytic properties. A nanosheet mordenite zeolite with a thickness of ~11 nm, named as MOR‐NS, has been prepared using a well‐designed gemini‐type amphiphilic surfactant as bifunctional structure‐directing agent (SDA). Its benzyl diquarternary ammonium cations structurally directed the formation of MOR topology, whereas the long and hydrophobic hexadecyl tailing group prevented the extensive crystal growth along b axis. This kind of orientated crystallization took place through the inorganic‐organic interaction between silica species and SDA molecules existing in the whole process. The thin MOR nanosheets, with highly exposed (010) planes and 8‐membered ring (MR) windows therein, exhibited an extremely higher ethylene selectivity (42.1%) for methanol‐to‐olefin reactions when compared with conventional bulk MOR crystals (3.3%). Moreover, MOR‐NS also possessed hierarchical structure and larger external surface area, making it a promising catalyst for processing bulky reactions like the alkylation of anisole with benzyl alcohol.

EPR distance measurements on long non‐coding RNAs empowered by genetic alphabet expansion transcription

By Christof Domnick, Frank Eggert, Christine Wuebben, Lisa Bornewasser, Gregor Hagelueken, Olav Schiemann, Stephanie Kath-Schorr from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 25, 2020.

Unnatural base pairs meet EPR: We here present a novel nitroxide spin label‐containing RNA triphosphate TPT3 NO and its application for site‐specific spin labeling of RNA via in vitro transcription using an expanded genetic alphabet. Our strategy allows the facile preparation of spin labeled RNAs with sizes ranging from short RNA oligonucleotides to large, complex RNA molecules with over 370 nucleotides by standard in vitro transcription. As proof of concept, inter‐spin distance distributions are measured by pulsed electron paramagnetic resonance (EPR) spectroscopy in short self‐complementary RNA sequences and in a well‐studied 185 nucleotide non‐coding RNA, the B. subtilis glmS ribozyme. The approach is then applied to probe for the first time the folding of the 377 nucleotide long A‐region of the long non‐coding RNA Xist, by PELDOR.

Catalytic Regioselective Isomerization of 2,2‐Disubstituted Oxetanes to Homoallylic Alcohols.

By Antoni Riera, Albert Cabré, Sergi Rafael, Giuseppe Sciortino, Gregori Ujaque, Agusti LLedos, Xavier Verdaguer from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 25, 2020.

The selective isomerization of strained heterocyclic compounds is an important tool in organic synthesis. An unprecedented regioselective isomerization of 2,2‐disubstituted oxetanes to homoallylic alcohols is described. The use of tris(pentafluorophenyl)borane (B(C6F5)3), a commercially available Lewis acid was key to obtain good yields and selectivities since other Lewis acids afforded mixtures of isomers and substantial polymerization. The reaction took place under exceptionally mild conditions and very low catalyst loading (0.5 mol %). DFT calculations disclose the mechanistic features of the isomerization and account for the high selectivity displayed by the B(C6F5)3 catalyst. The synthetic applicability of the new reaction is demonstrated by the preparation of γ‐chiral alcohols using iridium catalyzed asymmetric hydrogenation.

Calixarene‐Based Supramolecular AIE Dots with Highly Inhibited Nonradiative Decay and Intersystem Crossing for Ultrasensitive Fluorescence Image‐Guided Cancer Surgery

By Chao Chen, Xiang Ni, Han-Wen Tian, Qian Liu, Dong-Sheng Guo, Dan Ding from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 25, 2020.

Molecular motion‐associated organic molecules such as aggregation‐induced emission luminogens (AIEgens) for disease phototheranostics are attracting increasing attention; however, how to optimally harvest absorbed excitation energy for advanced fluorescence imaging/diagnosis and concurrently avoid unnecessary phototoxicity during bioimaging process is still challenging. To address this issue, herein, we report that the host‐guest complexation between calix[5]arene and AIEgen can significantly turn off both the energy dissipation pathways of intersystem crossing and thermal deactivation, enabling the absorbed excitation energy mostly focusing on fluorescence emission. The co‐assembly of calix[5]arene amphiphiles and AIEgens affords highly emissive supramolecular AIE nanodots thanks to their interaction extremely restricting the intramolecular motion of AIEgens, which also show negligible cytotoxic reactive oxygen species generation. In vivo studies with a peritoneal carcinomatosis‐bearing mouse model indicate that such supramolecular AIE dots have rather low in vivo side toxicity and can serve as a superior fluorescent bioprobe for ultrasensitive fluorescence image‐guided cancer surgery.

Melamine foam and cellulose nanofiber co-mediated assembly of graphene nanoplatelets to construct three-dimensional network towards advanced phase change material

By Yong Wang from RSC - Nanoscale latest articles. Published on Jan 25, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR10696K, Paper
Fei Xue, Xin-zheng Jin, Wen-yan Wang, Xiaodong Qi, Jinghui Yang, Yong Wang
Organic phase change materials (OPCMs) play a great role in energy management for their large phase change enthalpy, but the intrinsic low thermal conductivity (TC) and bad encapsulation severely restrict...
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Compromising science by ignorant instrument calibration ‐ need to revisit half a century of published XPS data

By Grzegorz Greczynski, Lars Hultman from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

X‐ray photoelectron spectroscopy (XPS) is an indispensable technique in modern materials science for the determination of chemical bonding as evidenced by more than 10000 XPS papers published annually. A literature survey reveals that in the vast majority of cases an incorrect referencing of the binding energy scale is used, neglecting warnings that have been formulated from the early days of the technique. Consequences for the data reliability are disastrous and decades of XPS work require revisiting. The purpose of this Viewpoint is to highlight the existing problems, review the criticism and suggest ways forward.

An Unconventional Transient Phase with Cycloidal Order of Polarization in Energy‐Storage Antiferroelectric PbZrO3

By Xian‐Kui Wei, Chun‐Lin Jia, Hong‐Chu Du, Krystian Roleder, Joachim Mayer, Rafal E. Dunin‐Borkowski from Wiley: Advanced Materials: Table of Contents. Published on Jan 24, 2020.

Antiferroelectrics are an important material system for electrostatic energy storage. However, the associated antiferroelectric–ferroelectric transition has not been clarified in the past decades. Driven by electron‐beam irradiation, time‐ and atomic‐resolution electron microscopy unveils a novel ferrodistortive phase, characteristic of a cycloidal polarization order, during the phase‐transition process. This opens up a field to search for ferroelectrics with noncollinear polarization orders. Abstract Antiferroelectric‐based dielectric capacitors are receiving tremendous attention for their outstanding energy‐storage performance and extraordinary flexibility in collecting pulsed powers. Nevertheless, the in situ atomic‐scale structural‐evolution pathway, inherently coupling to the energy storage process, has not been elucidated for the ultimate mechanistic understanding so far. Here, time‐ and atomic‐resolution structural phase evolution in antiferroelectric PbZrO3 during storage of energy from the electron‐beam illumination is reported. By employing state‐of‐the‐art negative‐spherical‐aberration imaging technique, the quantitative transmission electron microscopy study presented herein clarifies that the hierarchical evolution of polar oxygen octahedra associated with the unit‐cell volume change and polarization rotation accounts for the stepwise antiferroelectric‐to‐ferroelectric phase transition. In particular, an unconventional ferroelectric category—the ferrodistortive phase characteristic of a unique cycloidal polarization order—is established during the dynamic structure investigation. Through clarifying the atomic‐scale phase transformation pathway, findings of this work unveil a new territory to explore novel ferrodistortive phases in energy‐storage materials with the nonpolar‐to‐polar phase transitions.

Barrierless Free Charge Generation in the High‐Performance PM6:Y6 Bulk Heterojunction Non‐Fullerene Solar Cell

By Lorena Perdigón‐Toro, Huotian Zhang, Anastasia Markina, Jun Yuan, Seyed Mehrdad Hosseini, Christian M. Wolff, Guangzheng Zuo, Martin Stolterfoht, Yingping Zou, Feng Gao, Denis Andrienko, Safa Shoaee, Dieter Neher from Wiley: Advanced Materials: Table of Contents. Published on Jan 24, 2020.

The efficiency of photocurrent generation is studied in the high‐efficiency non‐fullerene PM6:Y6 blend, using a combination of field‐ and temperature‐dependent optoelectronic measurements. These experiments reveal barrierless free charge generation, despite a small driving force. Theoretical modeling suggests the existence of a large electrostatic interfacial field, which pushes charges away from the donor–acceptor interface. Abstract Organic solar cells are currently experiencing a second golden age thanks to the development of novel non‐fullerene acceptors (NFAs). Surprisingly, some of these blends exhibit high efficiencies despite a low energy offset at the heterojunction. Herein, free charge generation in the high‐performance blend of the donor polymer PM6 with the NFA Y6 is thoroughly investigated as a function of internal field, temperature and excitation energy. Results show that photocurrent generation is essentially barrierless with near‐unity efficiency, regardless of excitation energy. Efficient charge separation is maintained over a wide temperature range, down to 100 K, despite the small driving force for charge generation. Studies on a blend with a low concentration of the NFA, measurements of the energetic disorder, and theoretical modeling suggest that CT state dissociation is assisted by the electrostatic interfacial field which for Y6 is large enough to compensate the Coulomb dissociation barrier.

Development of Copper Nanoclusters for In Vitro and In Vivo Theranostic Applications

By Wing‐Fu Lai, Wing‐Tak Wong, Andrey L. Rogach from Wiley: Advanced Materials: Table of Contents. Published on Jan 24, 2020.

Copper nanoclusters are an emerging class of fluorophores which can be synthesized using “top‐down” or “bottom‐up” approaches. Their emissive and physiological performance can be enhanced by using various techniques, ranging from surface engineering to size manipulation, for theranostic applications. Abstract Theranostics refers to the incorporation of therapeutic and diagnostic functions into one material system. An important class of nanomaterials exploited for theranostics is metal nanoclusters (NCs). In contrast to gold and silver NCs, copper is an essential trace element for humans. It can be more easily removed from the body. This, along with the low cost of copper that offers potential large‐scale nanotechnology applications, means that copper NCs have attracted great interest in recent years. The latest advances in the design, synthesis, surface engineering, and applications of copper NCs in disease diagnosis, monitoring, and treatment are reviewed. Strategies to control and enhance the emission of copper NCs are considered. With this synopsis of the up‐to‐date development of copper NCs as theranostic agents, it is hoped that insights and directions for translating current advances from the laboratory to the clinic can be further advanced and accelerated.

Enlightening Materials with Photoswitches

By Alexis Goulet‐Hanssens, Fabian Eisenreich, Stefan Hecht from Wiley: Advanced Materials: Table of Contents. Published on Jan 24, 2020.

Controlling material properties with light is key for the development of optical technologies. In this context, molecular photoswitches have become powerful tools to induce structural changes, which can be translated and amplified to the macroscopic materials and device level. The implementation of photoswitches into a variety of materials, ranging from amorphous to crystalline, and their multifaceted operating principles are reviewed. Abstract Incorporating molecular photoswitches into various materials provides unique opportunities for controlling their properties and functions with high spatiotemporal resolution using remote optical stimuli. The great and largely still untapped potential of these photoresponsive systems has not yet been fully exploited due to the fundamental challenges in harnessing geometrical and electronic changes on the molecular level to modulate macroscopic and bulk material properties. Herein, progress made during the past decade in the field of photoswitchable materials is highlighted. After pointing to some general design principles, materials with an increasing order of the integrated photoswitchable units are discussed, spanning the range from amorphous settings over surfaces/interfaces and supramolecular ensembles, to liquid crystalline and crystalline phases. Finally, some potential future directions are pointed out in the conclusion. In view of the exciting recent achievements in the field, the future emergence and further development of light‐driven and optically programmable (inter)active materials and systems are eagerly anticipated.

The Role of Reverse Intersystem Crossing Using a TADF‐Type Acceptor Molecule on the Device Stability of Exciplex‐Based Organic Light‐Emitting Diodes

By Thanh Ba Nguyen, Hajime Nakanotani, Takuji Hatakeyama, Chihaya Adachi from Wiley: Advanced Materials: Table of Contents. Published on Jan 24, 2020.

The role of reverse intersystem crossing in the acceptor molecule on the device stability of exciplex based organic light‐emitting diodes is revealed. The addition of an electron‐donating unit onto the acceptor core can be prevented molecular degradation, and the TADF ability can also recycle triplet energy as exciplex emission, resulted in, significant improvement of the device lifetime is achieved. Abstract Exciplex system exhibiting thermally activated delayed fluorescence (TADF) holds a considerable potential to improve organic light‐emitting diode (OLED) performances. However, the operational lifetime of current exciplex‐based devices, unfortunately, falls far behind the requirement for commercialization. Herein, rationally choosing a TADF‐type electron acceptor molecule is reported as a new strategy to enhance OLEDs' operating lifetime. A comprehensive study of the exciplex system containing 9,9′,9′′‐triphenyl‐9H,9′H,9′′H‐3,3′:6′,3′′‐tercarbazole (Tris‐PCz) and triazine (TRZ) derivatives clarifies the relationship between unwanted carrier recombination on acceptor molecules, TADF property of acceptors, and the device degradation event. By employing a proposed “exciton recycling” strategy, a threefold increased operational lifetime can be achieved while still maintaining high‐performance OLED properties. In particular, a stable blue OLED that employs this strategy is successfully demonstrated. This research provides an important step for exciplex‐based devices toward the significant improvement of operational stability.

Nanoscale Guiding of Infrared Light with Hyperbolic Volume and Surface Polaritons in van der Waals Material Ribbons

By Irene Dolado, Francisco Javier Alfaro‐Mozaz, Peining Li, Elizaveta Nikulina, Andrei Bylinkin, Song Liu, James H. Edgar, Felix Casanova, Luis E. Hueso, Pablo Alonso‐González, Saül Vélez, Alexey Y. Nikitin, Rainer Hillenbrand from Wiley: Advanced Materials: Table of Contents. Published on Jan 24, 2020.

Infrared nanoimaging and theoretical simulations are applied to study phonon polariton waveguide modes in nanoscale hexagonal boron nitride ribbons. Fundamental volume and hybridized surface modes are identified. Most importantly, the symmetrically hybridized surface mode does not exhibit a cutoff width, and thus allows for linear waveguiding of infrared energy in the narrowest ribbons that can be fabricated. Abstract Van der Waals (vdW) materials host a variety of polaritons, which make them an emerging material platform for manipulating light at the nanoscale. Due to the layered structure of vdW materials, the polaritons can exhibit a hyperbolic dispersion and propagate as nanoscale‐confined volume modes in thin flakes. On the other hand, surface‐confined modes can be found at the flake edges. Surprisingly, the guiding of these modes in ribbons—representing typical linear waveguide structures—is widely unexplored. Here, a detailed study of hyperbolic phonon polaritons propagating in hexagonal boron nitride ribbons is reported. Employing infrared nanoimaging, a variety of modes are observed. Particularly, the fundamental volume waveguide mode that exhibits a cutoff width is identified, which, interestingly, can be lowered by reducing the waveguide thickness. Further, hybridization of the surface modes and their evolution with varying frequency and waveguide width are observed. Most importantly, it is demonstrated that the symmetrically hybridized surface mode does not exhibit a cutoff width, and thus enables linear waveguiding of the polaritons in arbitrarily narrow ribbons. The experimental data, supported by simulations, establish a solid basis for the understanding of hyperbolic polaritons in linear waveguides, which is of critical importance for their application in future photonic devices.

Interphases, Interfaces, and Surfaces of Active Materials in Rechargeable Batteries and Perovskite Solar Cells

By Chaofeng Liu, Jifeng Yuan, Robert Masse, Xiaoxiao Jia, Wenchao Bi, Zachary Neale, Ting Shen, Meng Xu, Meng Tian, Jiqi Zheng, Jianjun Tian, Guozhong Cao from Wiley: Advanced Materials: Table of Contents. Published on Jan 24, 2020.

Interfaces provide reactive zones and interphases stabilize electronic device operation. Understanding and designing interfaces and interphases represent an effective and efficient way for developing high‐performance rechargeable batteries and perovskite solar cells. Abstract The ever‐increasing demand for clean sustainable energy has driven tremendous worldwide investment in the design and exploration of new active materials for energy conversion and energy‐storage devices. Tailoring the surfaces of and interfaces between different materials is one of the surest and best studied paths to enable high‐energy‐density batteries and high‐efficiency solar cells. Metal‐halide perovskite solar cells (PSCs) are one of the most promising photovoltaic materials due to their unprecedented development, with their record power conversion efficiency (PCE) rocketing beyond 25% in less than 10 years. Such progress is achieved largely through the control of crystallinity and surface/interface defects. Rechargeable batteries (RBs) reversibly convert electrical and chemical potential energy through redox reactions at the interfaces between the electrodes and electrolyte. The (electro)chemical and optoelectronic compatibility between active components are essential design considerations to optimize power conversion and energy storage performance. A focused discussion and critical analysis on the formation and functions of the interfaces and interphases of the active materials in these devices is provided, and prospective strategies used to overcome current challenges are described. These strategies revolve around manipulating the chemical compositions, defects, stability, and passivation of the various interfaces of RBs and PSCs.

High Compression‐Induced Conductivity in a Layered Cu–Br Perovskite

By Adam Jaffe, Stephanie A. Mack, Yu Lin, Wendy L. Mao, Jeffrey B. Neaton, Hemamala I. Karunadasa from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Layered Cu–Cl perovskites show an electronic conductivity of 10−4 S cm−1 only above 50 GPa. In contrast, an analogous Cu‐Br perovskite exhibits a conductivity as high as 10−3 S cm−1 at only 2.6 GPa. Substitution of Br for Cl brings compression‐induced conductivity of layered copper‐halide perovskites to more technologically accessible pressures. Abstract We show that the onset pressure for appreciable conductivity in layered copper‐halide perovskites can decrease by ca. 50 GPa upon replacement of Cl with Br. Layered Cu–Cl perovskites require pressures >50 GPa to show a conductivity of 10−4 S cm−1, whereas here a Cu–Br congener, (EA)2CuBr4 (EA=ethylammonium), exhibits conductivity as high as 2×10−3 S cm−1 at only 2.6 GPa, and 0.17 S cm−1 at 59 GPa. Substitution of higher‐energy Br 4p for Cl 3p orbitals lowers the charge‐transfer band gap of the perovskite by 0.9 eV. This 1.7 eV band gap decreases to 0.3 eV at 65 GPa. High‐pressure X‐ray diffraction, optical absorption, and transport measurements, and density functional theory calculations allow us to track compression‐induced structural and electronic changes. The notable enhancement of the Br perovskite's electronic response to pressure may be attributed to more diffuse Br valence orbitals relative to Cl orbitals. This work brings the compression‐induced conductivity of Cu‐halide perovskites to more technologically accessible pressures.

Synthesis and Properties of 2,3‐Diethynyl‐1,3‐Butadienes

By Madison J. Sowden, Jas S. Ward, Michael S. Sherburn from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Diene to be chiral: The first general synthesis of 2,3‐diethynyl‐1,3‐butadienes (DEBDs) uses commodity precursors and involves, as a key step, an unprecedented twofold Sonogashira‐type cross‐coupling of a 2‐butyne‐1,4‐diol derivative. The value of DEBDs as building blocks for novel expanded dendralenes and expanded radialenes is also demonstrated. The latter exhibit an unprecedented form of atropisomerism. Abstract The first general preparative access to compounds of the 2,3‐diethynyl‐1,3‐butadiene (DEBD) class is reported. The synthesis involves a one‐pot, twofold Sonogashira‐type, Pd0‐catalyzed coupling of two terminal alkynes and a carbonate derivative of a 2‐butyne‐1,4‐diol. The synthesis is broad in scope and members of this structural family are kinetically stable enough to be handled using standard laboratory techniques at ambient temperature. They decompose primarily through heat‐promoted cyclodimerizations, which are impeded by alkyl substitution and accelerated by aryl or alkenyl substitution. An iterative sequence of these unprecedented Sonogashira‐type couplings generates a new type of expanded dendralene. A suitably substituted DEBD carrying two terminal alkyne groups undergoes Glaser–Eglinton cyclo‐oligomerization to produce a new class of expanded radialenes, which are chiral due to restricted rotation about their 1,3‐butadiene units. The structural features giving rise to atropisomerism in these compounds are distinct from those reported previously.

High‐Resolution Electrochemical Mapping of the Hydrogen Evolution Reaction on Transition‐Metal Dichalcogenide Nanosheets

By Yasufumi Takahashi, Yu Kobayashi, Ziqian Wang, Yoshikazu Ito, Masato Ota, Hiroki Ida, Akichika Kumatani, Keisuke Miyazawa, Takeshi Fujita, Hitoshi Shiku, Yuri E. Korchev, Yasumitsu Miyata, Takeshi Fukuma, Mingwei Chen, Tomokazu Matsue from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Nanoscale electrochemical cell: Understanding the hydrogen evolution reaction (HER) mechanism of MoS2 nanosheets requires a comprehensive understanding of the quantitative electrochemical properties and the distribution of active sites in real space. Scanning electrochemical cell microscopy (SECCM) is used to image and quantitatively analyze HER catalytically active sites in 1H MoS2 nanosheets. Abstract High‐resolution scanning electrochemical cell microscopy (SECCM) is used to image and quantitatively analyze the hydrogen evolution reaction (HER) catalytically active sites of 1H‐MoS2 nanosheets, MoS2, and WS2 heteronanosheets. Using a 20 nm radius nanopipette and hopping mode scanning, the resolution of SECCM was beyond the optical microscopy limit and visualized a small triangular MoS2 nanosheet with a side length of ca. 130 nm. The electrochemical cell provides local cyclic voltammograms with a nanoscale spatial resolution for visualizing HER active sites as electrochemical images. The HER activity difference of edge, terrace, and heterojunction of MoS2 and WS2 were revealed. The SECCM imaging directly visualized the relationship of HER activity and number of MoS2 nanosheet layers and unveiled the heterogeneous aging state of MoS2 nanosheets. SECCM can be used for improving local HER activities by producing sulfur vacancies using electrochemical reaction at the selected region.

An Adaptable N‐Heterocyclic Carbene Macrocycle Hosting Copper in Three Oxidation States

By Yang Liu, Stefan G. Resch, Iris Klawitter, George E. Cutsail, Serhiy Demeshko, Sebastian Dechert, Fritz E. Kühn, Serena DeBeer, Franc Meyer from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Kupfer(III)Macrocyclische LigandenN‐heterocyclische CarbeneOxidationsstufenRöntgenabsorptionsspektroskopieA neutral hybrid macrocycle L with two trans‐positioned N‐heterocyclic carbene (NHC) and two pyridine donors can adapt to the different geometric and electronic preferences of CuI, CuII, and CuIII. This allows isolation of a series of complexes hosting Cu in all three oxidation states, and their reversible interconversion at moderate potentials and with minor structural rearrangement. Abstract A neutral hybrid macrocycle with two trans‐positioned N‐heterocyclic carbenes (NHCs) and two pyridine donors hosts copper in three oxidation states (+I–+III) in a series of structurally characterized complexes (1–3). Redox interconversion of [LCu]+/2+/3+ is electrochemically (quasi)reversible and occurs at moderate potentials (E1/2=−0.45 V and +0.82 V (vs. Fc/Fc+)). A linear CNHC‐Cu‐CNHC arrangement and hemilability of the two pyridine donors allows the ligand to adapt to the different stereoelectronic and coordination requirements of CuI versus CuII/CuIII. Analytical methods such as NMR, UV/Vis, IR, electron paramagnetic resonance, and Cu Kβ high‐energy‐resolution fluorescence detection X‐ray absorption spectroscopies, as well as DFT calculations, give insight into the geometric and electronic structures of the complexes. The XAS signatures of 1–3 are textbook examples for CuI, CuII, and CuIII species. Facile 2‐electron interconversion combined with the exposure of two basic pyridine N sites in the reduced CuI form suggest that [LCu]+/2+/3+ may operate in catalysis via coupled 2 e−/2 H+ transfer.

Photoacoustic Imaging Quantifies Drug Release from Nanocarriers via Redox Chemistry of Dye‐Labeled Cargo

By Ananthakrishnan Soundaram Jeevarathinam, Jeanne E. Lemaster, Fang Chen, Eric Zhao, Jesse V. Jokerst from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A covalently linked paclitaxel–methylene blue conjugate (PTX‐MB) is used for real‐time monitoring of drug release from nanocarriers via photoacoustic imaging. The PTX‐MB remained in acoustically silent form when encapsulated in poly(lactic‐co‐glycolic acid) (PLGA) nanoparticles. After release, PTX‐MB instantly oxidized to the photoacoustically active form to report quantity and biodistribution. Abstract We report a new approach to monitor drug release from nanocarriers via a paclitaxel–methylene blue conjugate (PTX‐MB) with redox activity. This construct is in a photoacoustically silent reduced state inside poly(lactic‐co‐glycolic acid) (PLGA) nanoparticles (PTX‐MB@PLGA NPs). During release, PTX‐MB is spontaneously oxidized to produce a concentration‐dependent photoacoustic signal. An in vitro drug‐release study showed an initial burst release (25 %) between 0–24 h and a sustained release between 24–120 h with a cumulative release of 40.6 % and a 670‐fold increase in photoacoustic signal. An in vivo murine drug release showed a photoacoustic signal enhancement of up to 649 % after 10 hours. PTX‐MB@PLGA NPs showed an IC50 of 78 μg mL−1 and 44.7±4.8 % decrease of tumor burden in an orthotopic model of colon cancer via luciferase‐positive CT26 cells.

Fusion of Different Crosslinked Polymers Based on Dynamic Disulfide Exchange

By Ayuko Tsuruoka, Akira Takahashi, Daisuke Aoki, Hideyuki Otsuka from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Reversible link: The fusion of two different polymer networks by the dynamic behavior of bis(2,2,6,6‐tetramethylpiperidin‐1‐yl)disulfide (BiTEMPS) at the interface between different crosslinked polymers is reported. This fusion was accomplished by simply mixing and hot‐pressing powdered crosslinked polymers containing BiTEMPS units. Abstract Crosslinked polymers (CLPs) exhibit exceptional mechanical properties as well as good chemical and solvent resistance. However, their reprocessing, recycling, and modification remain difficult. One promising approach to overcome this limitation is to introduce dynamic covalent bonds that enable chain‐exchange reactions and network‐structure rearrangements in identical polymer networks (A–A fusion), resulting in self‐healing and reprocessing properties. Reported here is the fusion of two distinct polymer networks (A–B fusion) by the dynamic behavior of bis(2,2,6,6‐tetramethylpiperidin‐1‐yl)disulfide (BiTEMPS) at the interface between different CLPs. The appearance, swelling behavior, and mechanical properties of the fused samples indicate exchange reactions of the BiTEMPS units and the formation of topological bonds at the interface, commensurate with the generation of a CLP that exhibits tunable properties.

Tue 28 Jan 14:00: Patterns and Szemerédi phenomena in random fractals

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Patterns and Szemerédi phenomena in random fractals

I will talk about a joint work with Ville Suomala in which we find sharp dimension thresholds for the existence of various patterns in fractal percolation sets. Some of the configurations we study are homothetic copies of finite sets, angles and volumes of simplices. In the spirit of Szemeréti-type results in random discrete sets, we also study the corresponding problems in sets of positive natural measure.

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A Flexible Carbon Nanotube Sen‐Memory Device

By Ting‐Yu Qu, Yun Sun, Mao‐Lin Chen, Zhi‐Bo Liu, Qian‐Bing Zhu, Bing‐Wei Wang, Tian‐Yang Zhao, Chi Liu, Jun Tan, Song Qiu, Qing‐Wen Li, Zheng Han, Wei Wang, Hui‐Ming Cheng, Dong‐Ming Sun from Wiley: Advanced Materials: Table of Contents. Published on Jan 24, 2020.

Transformative nanodevices incorporate emerging nanotechnologies to meet future data‐intensive applications. A new flexible carbon nanotube transformative device named “sen‐memory” is developed, showing fused sensing‐and‐memory functionality and large scalability. The sen‐memory matrix realizes an in situ writing of optical data into nonvolatile memory without an auxiliary gate bias and the photogenerated pattern can be stored for a couple of years. Abstract In a modern electronics system, charge‐coupled devices and data storage devices are the two most indispensable components. Although there has been rapid and independent progress in their development during the last three decades, a cofunctionality of both sensing and memory at single‐unit level is yet premature for flexible electronics. For wearable electronics that work in ultralow power conditions and involve strains, conventional sensing‐and‐memory systems suffer from low sensitivity and are not able to directly transform sensed information into sufficient memory. Here, a new transformative device is demonstrated, which is called “sen‐memory”, that exhibits the dual functionality of sensing and memory in a monolithic integrated circuit. The active channel of the device is formed by a carbon nanotube thin film and the floating gate is formed by a controllably oxidized aluminum nanoparticle array for electrical‐ and optical‐programming. The device exhibits a high on–off current ratio of ≈106, a long‐term retention of ≈108 s, and durable flexibility at a bending strain of 0.4%. It is shown that the device senses a photogenerated pattern in seconds at zero bias and memorizes an image for a couple of years.

Mon 16 Mar 13:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Title to be confirmed

Abstract not available

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Mon 03 Feb 14:00: Atmospherically significant reactions of Criegee intermediates

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Atmospherically significant reactions of Criegee intermediates

The oxidative removal of volatile organic compounds from the Earth’s atmosphere is mostly by reactions initiated by hydroxyl (OH) radicals. However, there is growing recognition of the importance of reactions of ozone with unsaturated organic compounds, both as a source of OH and of other reactive intermediates. This talk will focus on the chemistry of carbonyl oxides (more commonly known as Criegee intermediates) produced by ozone reactions with alkenes. The zwitterionic / biradical character of the Criegee intermediates causes unusual reaction pathways with trace organic atmospheric constituents such as alcohols and carboxylic acids. The products of these reactions are polar, highly oxygenated organic species, the low vapour pressures of which encourage growth of secondary organic aerosol particles. The Bristol group’s studies combine laboratory measurements of reaction rates, synchrotron-based photoionization and mass spectrometry identification of reaction products, calculations of reaction pathways and kinetics, and modelling of the atmospheric chemistry to assess the importance of this Criegee intermediate chemistry in the troposphere.

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DNAzyme‐Mediated Genetically Encoded Sensors for Ratiometric Imaging of Metal Ions in Living Cells

By Mengyi Xiong, Zhenglin Yang, Ryan J. Lake, Junjie Li, Shanni Hong, Huanhuan Fan, Xiao‐Bing Zhang, Yi Lu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Metal ion sensing: Metal‐specific RNA‐cleaving DNAzymes were used to regulate the expression of fluorescent proteins. This strategy has expanded the range of genetically encoded fluorescent protein‐based sensors for metal ions significantly. Abstract Genetically encoded fluorescent proteins (FPs) have been used for metal ion detection. However, their applications are restricted to a limited number of metal ions owing to the lack of available metal‐binding proteins or peptides that can be fused to FPs and the difficulty in transforming the binding of metal ions into a change of fluorescent signal. We report herein the use of Mg2+‐specific 10–23 or Zn2+‐specific 8–17 RNA‐cleaving DNAzymes to regulate the expression of FPs as a new class of ratiometric fluorescent sensors for metal ions. Specifically, we demonstrate the use of DNAzymes to suppress the expression of Clover2, a variant of the green FP (GFP), by cleaving the mRNA of Clover2, while the expression of Ruby2, a mutant of the red FP (RFP), is not affected. The Mg2+ or Zn2+ in HeLa cells can be detected using both confocal imaging and flow cytometry. Since a wide variety of metal‐specific DNAzymes can be obtained, this method can likely be applied to imaging many other metal ions, expanding the range of the current genetically encoded fluorescent protein‐based sensors.

Photosynthetic Tumor Oxygenation by Photosensitizer‐Containing Cyanobacteria for Enhanced Photodynamic Therapy

By Minfeng Huo, Liying Wang, Linlin Zhang, Chenyang Wei, Yu Chen, Jianlin Shi from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A breath of fresh air: Cyanobacteria containing the photosensitizer chlorin e6 (ce6) have been designed to increase tumor oxygen levels by photosynthesis. The photosensitizer converts the oxygen produced by the cyanobacteria to singlet oxygen under laser irradiation for tumor therapy both in vitro and in vivo. This strategy enhances type‐II photodynamic therapy of hypoxic tumors. Abstract Sustained tumor oxygenation is of critical importance during type‐II photodynamic therapy (PDT), which depends on the intratumoral oxygen level for the generation of reactive oxygen species. Herein, the modification of photosynthetic cyanobacteria with the photosensitizer chlorin e6 (ce6) to form ce6‐integrated photosensitive cells, termed ceCyan, is reported. Upon 660 nm laser irradiation, sustained photosynthetic O2 evolution by the cyanobacteria and the immediate generation of reactive singlet oxygen species (1O2) by the integrated photosensitizer could be almost simultaneously achieved for tumor therapy using type‐II PDT both in vitro and in vivo. This work contributes a conceptual while practical paradigm for biocompatible and effective PDT using hybrid microorganisms, displaying a bright future in clinical PDT by microbiotic nanomedicine.

3‐O‐Sulfation of Heparan Sulfate Enhances Tau Interaction and Cellular Uptake

By Jing Zhao, Yanan Zhu, Xuehong Song, Yuanyuan Xiao, Guowei Su, Xinyue Liu, Zhangjie Wang, Yongmei Xu, Jian Liu, David Eliezer, Trudy F. Ramlall, Guy Lippens, James Gibson, Fuming Zhang, Robert J. Linhardt, Lianchun Wang, Chunyu Wang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Strengthened interactions: The rare 3‐O‐sulfation (3‐O‐S) of heparan sulfate (HS) enhances the tau–HS interaction and cellular uptake of tau, suggesting an important role for 3‐O‐S in the transcellular spread of tau pathology in Alzheimer's disease (AD). This work suggests a novel strategy for disease‐modifying treatment of AD by targeting the tau/HS interface. Abstract Prion‐like transcellular spreading of tau in Alzheimer's Disease (AD) is mediated by tau binding to cell surface heparan sulfate (HS). However, the structural determinants for tau–HS interaction are not well understood. Microarray and SPR assays of structurally defined HS oligosaccharides show that a rare 3‐O‐sulfation (3‐O‐S) of HS significantly enhances tau binding. In Hs3st1−/− (HS 3‐O‐sulfotransferase‐1 knockout) cells, reduced 3‐O‐S levels of HS diminished both cell surface binding and internalization of tau. In a cell culture, the addition of a 3‐O‐S HS 12‐mer reduced both tau cell surface binding and cellular uptake. NMR titrations mapped 3‐O‐S binding sites to the microtubule binding repeat 2 (R2) and proline‐rich region 2 (PRR2) of tau. Tau is only the seventh protein currently known to recognize HS 3‐O‐sulfation. Our work demonstrates that this rare 3‐O‐sulfation enhances tau–HS binding and likely the transcellular spread of tau, providing a novel target for disease‐modifying treatment of AD and other tauopathies.

Ti3C2: An Ideal Co‐catalyst?

By Biao Wang, Mengye Wang, Fangyan Liu, Qian Zhang, Shan Yao, Xiaolong Liu, Feng Huang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

It is graphene quantum dots (GQDs) derived from Ti3C2, rather than 2D Ti3C2 itself, that play the role of co‐catalyst for La2Ti2O7/Ti3C2 (LTC) composites during the photocatalytic reaction. Abstract How 2D Ti3C2 enhances photocatalytic efficiency remains unclear. Now, it is shown that it is graphene quantum dots (GQDs) derived from Ti3C2, rather than 2D Ti3C2 itself, that play the role of co‐catalyst for La2Ti2O7/Ti3C2 (LTC) composites during the photocatalytic reaction. After modification of Ti3C2 derivatives, the photocatalytic efficiency of La2Ti2O7 is enhanced 16 times over pure La2Ti2O7. Solid‐state NMR, Raman, and HRTEM results confirm the existence of GQDs in Ti3C2 and LTC composites. The GQDs are formed during the chemical change from Ti3AlC2 to Ti3C2 via HF etching, as Ti atoms are removed and unsaturated carbon bonds are left, which react with each other to form sp2 π‐conjugation GQDs. 2D Ti3C2 is completely oxidized to COx modified TiOx species, causing Ti3C2 to lose its electrical conductivity and the role as co‐catalyst. GQDs largely suppress the photogenerated charge recombination of La2Ti2O7, as revealed by the photoluminescence (PL) and transient photocurrent.

Iridium(III)‐Catalyzed Intermolecular C(sp3)−H Insertion Reaction of Quinoid Carbene: A Radical Mechanism

By Hai‐Xu Wang, Yann Richard, Qingyun Wan, Cong‐Ying Zhou, Chi‐Ming Che from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

On the rebound: Direct intermolecular C(sp3)−H arylation is achieved by an IrIII/porphyrin‐catalyzed formal quinoid carbene (QC) insertion reaction through a stepwise radical mechanism. This reaction is enabled by the hydrogen‐atom transfer (HAT) reactivity of the metal‐QC intermediate, and the subsequent radical rebound step is facilitated by an electrophilic IrIII center that preserves the radical character of the QC ligand. Abstract Described herein is an IrIII/porphyrin‐catalyzed intermolecular C(sp3)−H insertion reaction of a quinoid carbene (QC). The reaction was designed by harnessing the hydrogen‐atom transfer (HAT) reactivity of a metal‐QC species with aliphatic substrates followed by a radical rebound process to afford C−H arylation products. This methodology is efficient for the arylation of activated hydrocarbons such as 1,4‐cyclohexadienes (down to 40 min reaction time, up to 99 % yield, up to 1.0 g scale). It features unique regioselectivity, which is mainly governed by steric effects, as the insertion into primary C−H bonds is favored over secondary and/or tertiary C−H bonds in the substituted cyclohexene substrates. Mechanistic studies revealed a radical mechanism for the reaction.

Antiperovskite Intermetallic Nanoparticles for Enhanced Oxygen Reduction

By Hao Zhang, Wei Xia, Haoming Shen, Wenhan Guo, Zibin Liang, Kexin Zhang, Yingxiao Wu, Bingjun Zhu, Ruqiang Zou from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

ORR or nothing: Cobalt is an oxygen reduction reaction (ORR) inert metal, however, it can now be activated for this reaction by forming the intermetallic antiperovskite phase Co3InC0.7N0.3. Tailoring the C/N ratio strengthens both the desorption and the hydrogenation step thus optimizing ORR activity. Abstract Antiperovskite Co3InC0.7N0.3 nanomaterials with highly enhanced oxygen reduction reaction (ORR) performance were prepared by tuning nitrogen contents through a metal–organic framework (MOF)‐derived strategy. The nanomaterial surpasses all reported noble‐metal‐free antiperovskites and even most perovskites in terms of onset potential (0.957 V at J=0.1 mA cm−2) and half‐wave potential (0.854 V). The OER and zinc–air battery performance demonstrate its multifunctional oxygen catalytic activities. DFT calculation was performed and for the first time, a 4 e− dissociative ORR pathway on (200) facets of antiperovskite was revealed. Free energy studies showed that nitrogen substitution could strengthen the OH desorption as well as hydrogenation that accounts for the enhanced ORR performance. This work expands the scope for material design via tailoring the nitrogen contents for optimal reaction free energy and hence performance of the antiperovskite system.

Controllable Conversion of CO2 on Non‐Metallic Gold Clusters

By Dan Yang, Wei Pei, Si Zhou, Jijun Zhao, Weiping Ding, Yan Zhu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Non‐metallic gold clusters (Au9, Au11 and Au36) exhibit a atomicity‐dependent catalytic performance for the hydrogenation of CO2, selectively determining the reaction pathways towards C1 or C2 products. The exceptional properties of the non‐metallic gold clusters highlight the importance of pursuing non‐metallic metal clusters for catalytic applications. Abstract Gold nanoparticles in metallic or plasmonic state have been widely used to catalyze homogeneous and heterogeneous reactions. However, the catalytic behavior of gold catalysts in non‐metallic or excitonic state remain elusive. Atomically precise Aun clusters (n=number of gold atoms) bridge the gap between non‐metallic and metallic catalysts and offer new opportunities for unveiling the hidden properties of gold catalysts in the metallic, transition regime, and non‐metallic states. Here, we report the controllable conversion of CO2 over three non‐metallic Aun clusters, including Au9, Au11, and Au36, towards different target products: methane produced on Au9, ethanol on Au11, and formic acid on Au36. Structural information encoded in the non‐metallic clusters permits a precise correlation of atomic structure with catalytic properties and hence, provides molecular‐level insight into distinct reaction channels of CO2 hydrogenation over the three non‐metallic Au catalysts.

Control of Intramolecular Hydrogen Bonding in a Conformation‐Switchable Helical‐Spring Polymer by Solvent and Temperature

By Young‐Jae Jin, Toshiki Aoki, Giseop Kwak from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Uncoiled: A poly(phenylacetylene) derivative with a helical‐spring backbone stabilized by intramolecular hydrogen bonding responds to solvent and heat stimuli in a precisely controlled manner. The responses are visible as color fading and recovery during the process of conformational change and helix–coil transformations. Abstract A substituted poly(phenylacetylene) derivative (PPAHB) with two hydroxymethyl groups at the meta position of the side phenyl ring was examined as a conformation‐switchable helical spring polymer that responds to solvent and heat stimuli in a precisely controlled manner. Intramolecular hydrogen bonds, which cause the helical structure of the polymer, were broken and re‐formed by adjusting the hydrogen‐bonding strength values (pKHB) of various combinations of solvents or by varying the temperature. In this process, a reversible conformational change from cis–cisoid to cis–transoid, accompanied by a phase transition in the form of a helix‐coil transformation occurred, with the polymer exhibiting critical changes of color fading and recovery in specific environments. These results demonstrate that PPAHB can be used as either a pKHB indicator or a thermometer. The color changes of the polymer solution are described in detail based on spectroscopic analyses and thermodynamic considerations.

Phosphine‐Catalyzed [4+1] Cycloadditions of Allenes with Methyl Ketimines, Enamines, and a Primary Amine

By Ze‐Hun Cao, Yu‐Hao Wang, Subarna Jyoti Kalita, Uwe Schneider, Yi‐Yong Huang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Phosphine‐catalyzed [4+1] cycloadditions of an allene with methyl ketimines and enamines via 1,4‐(bis)electrophilic α,β‐unsaturated ketenyl phosphonium intermediate have been demonstrated to give cyclopentenoyl enamines and imines, respectively. Abstract Unprecedented phosphine‐catalyzed [4+1] cycloadditions of allenyl imides have been discovered using various N‐based substrates including methyl ketimines, enamines, and a primary amine. These transformations provide a one‐pot access to cyclopentenoyl enamines and imines, or (chiral) γ‐lactams through two geminal C−C bond or two C−N bond formations, respectively. Several P‐based key intermediates including a 1,4‐(bis)electrophilic α,β‐unsaturated ketenyl phosphonium species have been detected by 31P NMR and HRMS analyses, which shed light on the postulated catalytic cycle. The synthetic utility of this new chemistry has been demonstrated through a gram‐scaling up of the catalytic reaction as well as regioselective hydrogenation and double condensation to form cyclopentanoyl enamines and fused pyrazole building blocks, respectively.

Programming DNA Nanoassembly for Enhanced Photodynamic Therapy

By Min Pan, Qunying Jiang, Junlin Sun, Zhen Xu, Yizhuo Zhou, Li Zhang, Xiaoqing Liu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Designer DNA nanosponges relieve hypoxia‐associated resistance and enhance photodynamic therapy (PDT). The facile assembly process, robust in vitro and in vivo therapeutic efficacy, and good biosafety demonstrate a practical platform of PDT for biomedical applications. This approach also suggests that DNA nanotechnology has great potential for advanced therapeutics. Abstract Photodynamic therapy (PDT) has extraordinary promise for the treatment of many cancers. However, its clinical progress is impaired by the intrinsic hypoxic tumor microenvironment that limits PDT efficacy and the safety concern associated with biological specificity of photosensitizers or vehicles. Now it is demonstrated that rationally designed DNA nanosponges can load and delivery photosensitizer effectively, target tumor precisely, and relieve hypoxia‐associated resistance remarkably to enhance the efficacy of PDT. Specifically, the approach exhibits a facile assembly process, provides programmable and versatile nanocarriers, and enables robust in vitro and in vivo anti‐cancer efficacy with excellent biosafety. These findings represent a practical and safe approach by designer DNA nanoassemblies to combat cancer effectively and suggest a powerful strategy for broad biomedical application of PDT.

Imidazotetrazines as Weighable Diazomethane Surrogates for Esterifications and Cyclopropanations

By Riley L. Svec, Paul J. Hergenrother from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

From patient to flask: Temozolomide (the standard of care for glioblastoma) and other imidazotetrazine compounds are repurposed into synthetic reagents. The prodrugs release alkyl diazonium species under aqueous conditions and were thus employed to conduct the two most widely used reactions of diazomethane, esterifications and cyclopropanations. Abstract Diazomethane is one of the most versatile reagents in organic synthesis, but its utility is limited by its hazardous nature. Although alternative methods exist to perform the unique chemistry of diazomethane, these suffer from diminished reactivity and/or correspondingly harsher conditions. Herein, we describe the repurposing of imidazotetrazines (such as temozolomide, TMZ, the standard of care for glioblastoma) for use as synthetic precursors of alkyl diazonium reagents. TMZ was employed to conduct esterifications and metal‐catalyzed cyclopropanations, and results show that methyl ester formation from a wide variety of substrates is especially efficient and operationally simple. TMZ is a commercially available solid that is non‐explosive and non‐toxic, and should find broad utility as a replacement for diazomethane.

Magnetic Field Directed Rare‐Earth Separations

By Robert F. Higgins, Thibault Cheisson, Bren E. Cole, Brian C. Manor, Patrick J. Carroll, Eric J. Schelter from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Subtle differences: Rare‐earth separations generally rely on small differences in the ionic radii of the trivalent oxidation state. A process for the separation of rare‐earth elements has been developed which is enhanced by the presence of an external magnetic field. Abstract The separation of rare‐earth ions from one another is challenging due to their chemical and physical similarities. Nearly all rare‐earth separations rely upon small changes in ionic radii to direct speciation or reactivity. Herein, we show that the intrinsic magnetic properties of the rare‐earth ions impact the separations of light/heavy and selected heavy/heavy binary mixtures. Using TriNOx3− ([{(2‐tBuNO)C6H4CH2}3N]3−) rare‐earth complexes, we efficiently and selectively crystallized heavy rare earths (Tb–Yb) from a mixture with light rare earths (La and Nd) in the presence of an external Fe14Nd2B magnet, concomitant with the introduction of a concentration gradient (decrease in temperature). The optimal separation was observed for an equimolar mixture of La:Dy, which gave an enrichment factor of EFLa:Dy=297±31 for the solid fraction, compared to EFLa:Dy=159±22 in the absence of the field, and achieving a 99.7 % pure Dy sample in one step. These results indicate that the application of a magnetic field can improve performance in a molecular separation system for paramagnetic rare‐earth cations.

Highly Selective Recovery of Lanthanides by Using a Layered Vanadate with Acid and Radiation Resistance

By Haiyan Sun, Yang Liu, Jian Lin, Zenghui Yue, Weian Li, Jiance Jin, Qian Sun, Yuejie Ai, Meiling Feng, Xiaoying Huang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

The selective recovery of lanthanides is realized by a simple crystalline vanadate with acid and radiation resistance. It shows high capacities, excellent selectivity for lanthanides, and convenient elution. The adsorption mechanism is revealed by calculations and XPS, EXAFS, Raman, and elemental analysis. This supports the development of crystalline vanadates for environmental remediation. Abstract It is of vital importance to capture lanthanides (nuclear fission products) from waste solutions for radionuclide remediation owing to their hazards. The effective separation of lanthanides are achieved by an acid/base‐stable and radiation‐resistant vanadate, namely, [Me2NH2]V3O7 (1). It exhibits high adsorption capacities for lanthanides (qmEu=161.4 mg g−1; qmSm=139.2 mg g−1). And high adsorption capacities are maintained over a pH range of 2.0–6.9 (qmEu=75.1 mg g−1 at low pH of 2.5). It displays high selectivity for Eu3+ (simulant of An3+) against a large excess of interfering ions. It can efficiently separate Eu3+ and Cs+ (or Sr2+) with the highest separation factor SFEu/Cs of 156 (SFEu/Sr of 134) to date. The adsorption mechanism is revealed by calculations and XPS, EXAFS, Raman, and elemental analyses. These merits combined with facile synthesis and convenient elution makes the title vanadate a promising lanthanide scavenger for environmental remediation.

Developing Luminescent Ratiometric Thermometers Based on a Covalent Organic Framework (COF)

By Anna M. Kaczmarek, Ying‐Ya Liu, Mariusz K. Kaczmarek, Hengshuo Liu, Flavia Artizzu, Luís D. Carlos, Pascal Van Der Voort from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A hot candidate: Covalent organic frameworks (COFs) are reported to be an excellent support for the grafting of lanthanide ions/complexes and allow the development of novel types of luminescent thermometers. A unique behavior, that is, no thermal quenching of the Tb3+ emission, is observed in these LnCOF materials. Abstract Covalent Organic Frameworks (COFs), an emerging class of crystalline porous materials, are proposed as a new type of support for grafting lanthanide ions (Ln3+) and employing these hybrid materials as ratiometric luminescent thermometers. A TpBpy‐COF—prepared from 1,3,5‐triformylphloroglucinol (Tp) and 2,2′‐bipyridine‐5,5′‐diamine (Bpy) grafted with Eu/Tb and Dy acetylacetone (acac) complexes can be successfully used as a luminescent thermometer in the 10–360 K (Eu) and 280–440 K (Tb) ranges with good sensing properties (thermal sensitivity up to 1.403 % K−1, temperature uncertainty δT

Temperature‐Directed Micellar Morphological Transformation Using CABC‐Block Copolymers and Its Applications in Encapsulation and Hidden Segment

By Jie Zheng, Chen Chen, Atsushi Goto from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Designed CABC asymmetric multi‐block copolymers were used to attain unique temperature‐directed reversible micellar morphological transformation. This transformation gives rise to a conceptually new controlled encapsulation–release system and a hidden‐segment interfacial system. Abstract A temperature‐directed micellar morphological transformation was developed using CABC multi‐block copolymers with a hydrophobic block A, a hydrophilic block B, and a thermally responsive block C with a lower critical solution temperature (LCST). The micellar structure was switched from a star (below LCST) to a flower (above LCST). The transition temperature was tunable in a wide range (11–90 °C) by varying the C monomer composition. The large difference in the loading capacity between the star and flower enabled efficient encapsulation and controlled release of external molecules. Unlike conventional systems, the present star‐to‐flower transformation keeps micellar structures and hence does not liberate polymers but only external molecules selectively. Another application is a hidden functional segment. A functional segment is hidden (shielded) below the LCST and exposed to interact with external molecules or surfaces above the LCST.

In Situ Generation and Stabilization of Accessible Cu/Cu2O Heterojunctions inside Organic Frameworks for Highly Efficient Catalysis

By Kai Chen, Jia‐Long Ling, Chuan‐De Wu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A strategy to generate and stabilize Cu/Cu2O nanojunctions inside porous organic frameworks is developed by controlled pyrolysis of metal–organic frameworks. This results in a composite material that consists of easily accessed Cu/Cu2O heterojunctions inside porous organic matrices that exhibit excellent catalytic properties in the hydrogenation of furfural into furfuryl alcohol. Abstract Heterostructural metal/metal oxides are the very promising substituents of noble‐metal catalysts; however, generation and further stabilization of accessible metal/metal oxide heterojunctions are very difficult. A strategy to encapsulate and stabilize Cu/Cu2O nanojunctions in porous organic frameworks in situ is developed by tuning the acrylate contents in copper‐based metal–organic frameworks (Cu‐MOFs) and the pyrolytic conditions. The acrylate groups play important roles on improving the polymerization degree of organic frameworks and generating and stabilizing highly dispersed and accessible Cu/Cu2O heteronanojunctions. As a result, pyrolysis of the MOF ZJU‐199, consisting of three acrylates per ligand, generates abundant heterostructural Cu/Cu2O discrete domains inside porous organic matrices at 350 °C, demonstrating excellent catalytic properties in liquid‐phase hydrogenation of furfural into furfuryl alcohol, which are much superior to the non‐noble metal‐based catalysts.

Model‐Based Nanoengineered Pharmacokinetics of Iron‐Doped Copper Oxide for Nanomedical Applications

By Hendrik Naatz, Bella B. Manshian, Carla Rios Luci, Vasiliki Tsikourkitoudi, Yiannis Deligiannakis, Johannes Birkenstock, Suman Pokhrel, Lutz Mädler, Stefaan J. Soenen from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A pharmacokinetic model: Dissolution kinetics from iron‐doped copper oxide nanoparticles were modelled to establish structure–release relationships. With those finely tuned kinetics, a cancer treatment orthogonal to conventional chemotherapy was achieved both in vitro and in vivo. Immunization of all animals occurred, rendering them protected against tumor relapse, even upon re‐engraftment of tumor cells. Abstract The progress in nanomedicine (NM) using nanoparticles (NPs) is mainly based on drug carriers for the delivery of classical chemotherapeutics. As low NM delivery rates limit therapeutic efficacy, an entirely different approach was investigated. A homologous series of engineered CuO NPs was designed for dual purposes (carrier and drug) with a direct chemical composition–biological functionality relationship. Model‐based dissolution kinetics of CuO NPs in the cellular interior at post‐exposure conditions were controlled through Fe‐doping for intra/extra cellular Cu2+ and biological outcome. Through controlled ion release and reactions taking place in the cellular interior, tumors could be treated selectively, in vitro and in vivo. Locally administered NPs enabled tumor cells apoptosis and stimulated systemic anti‐cancer immune responses. We clearly show therapeutic effects without tumor cells relapse post‐treatment with 6 % Fe‐doped CuO NPs combined with myeloid‐derived suppressor cell silencing.

Synthesis, Structure, and Reactivity of 5‐(Aryl)dibenzothiophenium Triflates

By Kevin Kafuta, André Korzun, Marvin Böhm, Christopher Golz, Manuel Alcarazo from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Easy on, easy off: 5‐(aryl)dibenzothiophenium triflates were prepared by highly selective metal‐free C−H sulfenylation of arenes. Interestingly, these salts undergo site‐selective Suzuki–Miyaura coupling in the presence of C−I bonds, enabling the iterative synthesis of polyaromatics. Abstract A synthetic protocol for the preparation of 5‐(aryl)dibenzothiophenium salts starting from inexpensive dibenzothiophene S‐oxide and simple arenes is reported. The scope of the method regarding the nature of the arene is evaluated, intermediates along the reaction sequence have been trapped, and side‐reactions identified. In addition, the X‐ray structures of a complete set of these salts are reported and their reactivities studied. Specifically, chemoselective Suzuki coupling is observed at the dibenzothiophenium in the presence of iodides.

Radical Acylfluoroalkylation of Olefins through N‐Heterocyclic Carbene Organocatalysis

By Jun‐Long Li, Yan‐Qing Liu, Wen‐Lin Zou, Rong Zeng, Xiang Zhang, Yue Liu, Bo Han, Yu He, Hai‐Jun Leng, Qing‐Zhu Li from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Organocatalytic acylfluoroalkylation: A multicomponent radical acylfluoroalkylation of olefins through NHC organocatalysis was developed, and over 120 examples of fluoroketones were facilely accessed from simple materials. Moreover, a dearomative difunctionalization of indoles could be readily achieved in a highly diastereoselective manner. The generality and practicality were highlighted by the late‐stage modification of drug skeletons. Abstract Fluorinated ketones are widely prevalent in numerous biologically interesting molecules, and the development of novel transformations to access these structures is an important task in organic synthesis. Herein, we report the multicomponent radical acylfluoroalkylation of a variety of olefins in the presence of various commercially available aromatic aldehydes and fluoroalkyl reagents through N‐heterocyclic carbene organocatalysis. With this protocol, over 120 examples of functionalized ketones with diverse fluorine substituents have been synthesized in up to 99 % yield with complete regioselectivity. The generality of this catalytic strategy was further highlighted by its successful application in the late‐stage functionalization of pharmaceutical skeletons. Excellent diastereoselectivity could be achieved in the reactions forging multiple stereocenters. In addition, preliminary results have been achieved on the catalytic asymmetric variant of the olefin difunctionalization process.

2019 Awards of the Materials Research Society

By from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Graphical Abstract: Angew. Chem. Int. Ed. 5/2020

By from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Frontispiece: 3‐O‐Sulfation of Heparan Sulfate Enhances Tau Interaction and Cellular Uptake

By Jing Zhao, Yanan Zhu, Xuehong Song, Yuanyuan Xiao, Guowei Su, Xinyue Liu, Zhangjie Wang, Yongmei Xu, Jian Liu, David Eliezer, Trudy F. Ramlall, Guy Lippens, James Gibson, Fuming Zhang, Robert J. Linhardt, Lianchun Wang, Chunyu Wang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Proteins L. Wang, C. Wang, and co‐workers report in their Research Article on page 1818 how a rare 3‐O‐sulfation of heparan sulfate significantly enhances tau binding and cellular uptake of tau, thus providing a novel target for treating Alzheimer′s disease.

Inside Back Cover: Model‐Based Nanoengineered Pharmacokinetics of Iron‐Doped Copper Oxide for Nanomedical Applications (Angew. Chem. Int. Ed. 5/2020)

By Hendrik Naatz, Bella B. Manshian, Carla Rios Luci, Vasiliki Tsikourkitoudi, Yiannis Deligiannakis, Johannes Birkenstock, Suman Pokhrel, Lutz Mädler, Stefaan J. Soenen from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

The controlled dissolution kinetics of iron‐doped copper oxide nanoparticles are applied in targeted nanomedicine. In their Research Article on page 1828, L. Mädler, S. J. Soenen et al. present a model‐based approach for adjusting the dissolution kinetics and intracellular release of copper that opens a therapeutic window for cancer treatment. Copper homeostasis regulates elevated copper levels for the slow release in peripheral cells but is insufficient for the fast release in cancer cells.

Back Cover: Developing Luminescent Ratiometric Thermometers Based on a Covalent Organic Framework (COF) (Angew. Chem. Int. Ed. 5/2020)

By Anna M. Kaczmarek, Ying‐Ya Liu, Mariusz K. Kaczmarek, Hengshuo Liu, Flavia Artizzu, Luís D. Carlos, Pascal Van Der Voort from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Covalent organic frameworks (COFs) can be grafted with Eu3+ and Tb3+ complexes, which decrease the pore size of the material when attached to the COF. As reported by A. M. Kaczmarek, L. D. Carlos et al. in their Research Article on page 1932, the Eu3+ and Tb3+ ions emit red and green light, respectively, and allow the system to be used as a luminescence thermometer. This is the first reported example of a COF material being used for this application.

Inside Cover: Radical Acylfluoroalkylation of Olefins through N‐Heterocyclic Carbene Organocatalysis (Angew. Chem. Int. Ed. 5/2020)

By Jun‐Long Li, Yan‐Qing Liu, Wen‐Lin Zou, Rong Zeng, Xiang Zhang, Yue Liu, Bo Han, Yu He, Hai‐Jun Leng, Qing‐Zhu Li from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

The multicomponent acylfluoroalkylation of olefins through N‐heterocyclic carbene (NHC) organocatalysis is presented by J.‐L. Li, B. Han, Q.‐Z. Li and co‐workers in their Research Article page 1863. A broad spectrum of olefins, including styrenes, cyclic alkenes, indoles, vinyl ethers, vinyl esters, and unactivated alkenes, are compatible with this system. The generality of this method is further highlighted by the late‐stage modification of pharmaceutical skeletons.

Cover Picture: Programming DNA Nanoassembly for Enhanced Photodynamic Therapy (Angew. Chem. Int. Ed. 5/2020)

By Min Pan, Qunying Jiang, Junlin Sun, Zhen Xu, Yizhuo Zhou, Li Zhang, Xiaoqing Liu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Designer DNA nanosponges can enhance the efficacy of photodynamic therapy by relieving hypoxia‐associated resistance, as reported by X. Liu et al. in their Research Article on page 1897. The programmable DNA assembly provides a safe and effective approach for in vitro and in vivo cancer treatment.

Direct C−H Bond Borylation of (Hetero)Arenes: Evolution from Noble Metal to Metal Free

By Yahui Li, Xiao‐Feng Wu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Impressive developments in the direct C−H bond borylation of (hetero)arenes have been achieved in the past decades. The applied catalysts are shifting from noble metals to metal‐free systems. This Highlight gives a brief summary of this evolution and focuses on recent elegant work in this field. Abstract Organoboron compounds are among the most versatile and useful building blocks in modern synthetic chemistry. The past decades have seen impressive developments in the direct C−H bond borylation of (hetero)arenes in which the applied catalysts are shifting from noble metals to metal‐free systems. This Highlight gives a brief summary on this evolution and focuses on recent elegant work in this field.

Surface Plasmon Resonance Microscopy: From Single‐Molecule Sensing to Single‐Cell Imaging

By Xiao‐Li Zhou, Yunze Yang, Shaopeng Wang, Xian‐Wei Liu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Surface plasmon resonance microscopy has emerged as a versatile platform for single‐molecule sensing and single‐cell imaging with high spatiotemporal resolution. This Minireview highlights the recent advances in the SPRM‐based analysis of single entities. Future challenges and their limitations as well as potential research directions are discussed. Abstract Surface plasmon resonance microscopy (SPRM) is a versatile platform for chemical and biological sensing and imaging. Great progress in exploring its applications, ranging from single‐molecule sensing to single‐cell imaging, has been made. In this Minireview, we introduce the principles and instrumentation of SPRM. We also summarize the broad and exciting applications of SPRM to the analysis of single entities. Finally, we discuss the challenges and limitations associated with SPRM and potential solutions.

Aromatic Chemistry in the Excited State: Facilitating Metal‐Free Substitutions and Cross‐Couplings

By Wenbo Liu, Jianbin Li, Chia‐Yu Huang, Chao‐Jun Li from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

How exciting! For aromatic substitutions and cross‐couplings, photochemical reactions provide an alternative to the classical reactions under thermal control. This Minireview summarizes the recent rapid progress of light‐enabled transition‐metal‐free aromatic reactions and discusses different reactivity modes of excited aryl electrophiles with nucleophiles from the mechanistic perspective. Abstract Transition‐metal‐catalyzed cross‐couplings between aromatic electrophiles and nucleophiles have revolutionized modern chemical syntheses. Nevertheless, transition‐metal‐free approaches are preferable, considering the various issues caused by metal catalysts. This Minireview summarizes the recent progress in the light‐enabled transition‐metal‐free formation of carbon–carbon and carbon–heteroatom bonds in aromatics, which opens a new avenue in aromatic reactions. From the mechanistic perspective, it classifies different reaction types of aryl electrophiles in an excited state with various nucleophiles. We believe this will provide more rationales for metal‐free aromatic substitutions and cross‐couplings with light, and guide the development of novel transformations of aromatic compounds facilitated by light.

Water: How Does It Influence the CaCO3 Formation?

By Huachuan Du, Esther Amstad from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

The fascinating properties of biomineral‐based materials produced by nature have inspired much work dedicated to the formation of biominerals. The current understanding of the formation of CaCO3, one of the most abundant biominerals, is summarized in this Review with special emphasis on the role of water in mediating the formation of CaCO3, an often overlooked aspect that is of high relevance. Abstract Nature produces biomineral‐based materials with a fascinating set of properties using only a limited number of elements. This set of properties is obtained by closely controlling the structure and local composition of the biominerals. We are far from achieving the same degree of control over the properties of synthetic biomineral‐based composites. One reason for this inferior control is our incomplete understanding of the influence of the synthesis conditions and additives on the structure and composition of the forming biominerals. In this Review, we provide an overview of the current understanding of the influence of synthesis conditions and additives during different formation stages of CaCO3, one of the most abundant biominerals, on the structure, composition, and properties of the resulting CaCO3 crystals. In addition, we summarize currently known means to tune these parameters. Throughout the Review, we put special emphasis on the role of water in mediating the formation of CaCO3 and thereby influencing its structure and properties, an often overlooked aspect that is of high relevance.

Photoinduced Radical Borylation of Alkyl Bromides Catalyzed by 4‐Phenylpyridine

By Li Zhang, Zhong‐Qian Wu, Lei Jiao from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

To B or not to Br: A visible‐light‐induced organocatalytic borylation reaction of unactivated alkyl bromides was developed. This reaction exhibits a broad substrate scope, and mechanistic studies revealed a novel nucleophilic substitution/photoinduced radical formation pathway. Abstract Utilizing pyridine catalysis, we developed a visible‐light‐induced transition‐metal‐free radical borylation reaction of unactivated alkyl bromides that features a broad substrate scope and mild reaction conditions. Mechanistic studies revealed a novel nucleophilic substitution/photoinduced radical formation pathway, which could be utilized to trigger a variety of radical processes.

Revealing the Nature of Singlet Fission under the Veil of Internal Conversion

By Long Wang, Shuming Bai, Yishi Wu, Yanping Liu, Jiannian Yao, Hongbing Fu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Deactivate by fission: An efficient intramolecular singlet fission (iSF) process, rather than detrimental internal conversion, is shown to be responsible for excited‐state deactivation in isoindigo derivatives. The 1(TT) states are generated nearly quantitatively in solution and can further split into two independent free triplets with a yield of about 180 % in solid thin films. Abstract Singlet fission (SF) holds the potential to boost the maximum power conversion efficiency of photovoltaic devices. Internal conversion (IC) has been considered as one of the major competitive deactivation pathways to transform excitation energy into heat. Now, using time‐resolved spectroscopy and theoretical calculation, it is demonstrated that, instead of a conventional IC pathway, an unexpected intramolecular singlet fission (iSF) process is responsible for excited state deactivation in isoindigo derivatives. The 1TT state could form at ultrafast rate and nearly quantitatively in solution. In solid films, the slipped stacked intermolecular packing of a thiophene‐functionalized derivative leads to efficient triplet pair separation, giving rise to an overall triplet yield of 181 %. This work not only enriches the pool of iSF‐capable materials, but also contributes to a better understanding of the iSF mechanism, which could be relevant for designing new SF sensitizers.

On the Products of Cholesterol Autoxidation in Phospholipid Bilayers and the Formation of Secosterols Derived Therefrom

By Emily L. Schaefer, Nadia Zopyrus, Zosia A. M. Zielinski, Glenn A. Facey, Derek A. Pratt from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Cholesterol autoxidation in phospholipid bilayers yields a similar product distribution to that observed in solution, where the epimers of the 7‐hydroperoxide (7‐OOH) are the main products. However, unlike in solution, vitamin E does not affect this product distribution. Cholesterol 7α‐OOH, but not 7β‐OOH, undergoes Hock fragmentation to yield novel 6,7‐epoxides and electrophilic A‐ring cleavage products largely indistinguishable from toxic secosterols. Abstract In homogenous solution, cholesterol autoxidation leads to a mixture of epimers of 5 primary products, whose concentrations vary in the presence/absence of antioxidants, such as vitamin E. Two of the products (5α‐OOH and 6β‐OOH) undergo Hock fragmentation to yield electrophilic secosterols implicated in disease. Herein, we show that the product distribution is similar in phospholipid bilayers, in that the 7‐OOHs are the major products, but the presence/absence of vitamin E has no effect on the distribution. Cholesterol 7α‐OOH, but not 7β‐OOH, undergoes Hock fragmentation to yield a mixture of unprecedented A‐ring cleavage products and 6,7‐epoxides. When subjected to typical derivatization conditions, 7α‐OOH yields products with essentially indistinguishable chromatographic and spectroscopic features from the previously identified secosterols, casting further doubt on their controversial origin from endogenous O3.

Hole and Electron Doping of the 4d Transition‐Metal Oxyhydride LaSr3NiRuO4H4

By Lun Jin, Michael A. Hayward from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Partially occupied: Hole or electron doping the oxyhydride LaSr3NiRuO4H4 creates a system with partial occupancy in the Ni/Ru –H 1s bands located in the (Ni/Ru)H2 sheets of these phases, which are analogous to the Cu –O 2p bands present in the CuO2 sheets of hole‐doped superconducting cuprates. Abstract Hole or electron doping of phases prepared by topochemical reactions (e.g. anion deintercalation or anion‐exchange) is extremely challenging as these low‐temperature conversion reactions are typically very sensitive to the electron counts of precursor phases. Herein we report the successful hole and electron doping of the transition‐metal oxyhydride LaSr3NiRuO4H4 by first preparing precursors in the range LaxSr4−xNiRuO8 0.5

Large‐Scale Synthesis of MOF‐Derived Superporous Carbon Aerogels with Extraordinary Adsorption Capacity for Organic Solvents

By Chaohai Wang, Jeonghun Kim, Jing Tang, Jongbeom Na, Yong‐Mook Kang, Minjun Kim, Hyunsoo Lim, Yoshio Bando, Jiansheng Li, Yusuke Yamauchi from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Walking on air: Metal–organic framework (MOF)‐based carbon aerogels (CAs) were fabricated through a simple and sustainable strategy on a large scale. The obtained CAs show a highly interconnected porous structure with low density (24 mg cm−3), a high specific surface area (516 m2 g−1), and a large pore volume (0.58 cm−3 g−1). The resulting CAs show significant potential for application in the adsorption of organic pollutants. Abstract Carbon aerogels (CAs) with 3D interconnected networks hold promise for application in areas such as pollutant treatment, energy storage, and electrocatalysis. In spite of this, it remains challenging to synthesize high‐performance CAs on a large scale in a simple and sustainable manner. We report an eco‐friendly method for the scalable synthesis of ultralight and superporous CAs by using cheap and widely available agarose (AG) biomass as the carbon precursor. Zeolitic imidazolate framework‐8 (ZIF‐8) with high porosity is introduced into the AG aerogels to increase the specific surface area and enable heteroatom doping. After pyrolysis under inert atmosphere, the ZIF‐8/AG‐derived nitrogen‐doped CAs show a highly interconnected porous mazelike structure with a low density of 24 mg cm−3, a high specific surface area of 516 m2 g−1, and a large pore volume of 0.58 cm−3 g−1. The resulting CAs exhibit significant potential for application in the adsorption of organic pollutants.

Amine‐Responsive Disassembly of AuI–CuI Double Salts for Oxidative Carbonylation

By Yanwei Cao, Jian‐Gong Yang, Yi Deng, Shengchun Wang, Qi Liu, Chaoren Shen, Wei Lu, Chi‐Ming Che, Yong Chen, Lin He from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Disassembly for catalysis: A sensitive amine‐induced disassembly of self‐assembled AuI‐CuI double salts was observed. Stimulated by the finding and understanding on this dynamic feature, a synergistic catalytic system for the oxidative carbonylation of primary and secondary amines (51 examples) to ureas and carbamates has been developed. Abstract A sensitive amine‐responsive disassembly of self‐assembled AuI‐CuI double salts was observed and its utilization for the synergistic catalysis was enlightened. Investigation of the disassembly of [Au(NHC)2][CuI2] revealed the contribution of Cu‐assisted ligand exchange of N‐heterocyclic carbene (NHC) by amine in [Au(NHC)2]+ and the capacity of [CuI2]− on the oxidative step. By integrating the implicative information coded in the responsive behavior and inherent catalytic functions of d10 metal complexes, a catalyst for the oxidative carbonylation of amines was developed. The advantages of this method were clearly reflected on mild reaction conditions and the significantly expanded scope (51 examples); both primary and steric secondary amines can be employed as substrates. The cooperative reactivity from Au and Cu centers, as an indispensable prerequisite for the excellent catalytic performance, was validated in the synthesis of (un)symmetric ureas and carbamates.

Stereoselective Base‐Catalyzed 1,1‐Silaboration of Terminal Alkynes

By Yiting Gu, Yaya Duan, Yangyang Shen, Ruben Martin from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A base‐catalyzed reaction for atom‐economical 1,1‐silaboration of terminal alkynes is described. This method features mild conditions and exquisite stereoselectivity. It offers a complementary approach to conventional 1,2‐ or 1,1‐difunctionalization techniques that typically require transition‐metal complexes or stoichiometric organometallic reagents, and an opportunity to build molecular complexity through subsequent C−Si and C−B cleavage. Abstract A base‐catalyzed reaction that enables stereoselective 1,1‐silaboration of terminal alkynes is described. This method not only offers a new strategy to functionalize simple and readily accessible alkynes beyond 1,2‐difunctionalization, but also provides an unconventional atom‐ and step‐economical approach to rapidly and reliably access versatile geminal silylboranes in the absence of transition metals and with exquisite stereoselectivity.

Tetrabenzononacene: “Butterfly Wings” Stabilize the Core

By Matthias Müller, Steffen Maier, Olena Tverskoy, Frank Rominger, Jan Freudenberg, Uwe H. F. Bunz from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Attachment of four benzo units electronically stabilizes a nonacene core without heteroatom substitution at/on the aromatic backbone. The four benzo units blueshift the absorption spectrum in comparison to a linear nonacene and significantly increase the stability in the solid state. Abstract In combination with bulky substituents at the core, fourfold benzannulation at the cata‐positions stabilizes a nonacene sufficiently to allow its isolation and characterization by 1H NMR and X‐ray analysis. The four benzo units blueshift the absorption spectrum in comparison to a solely linear nonacene, but significantly increase the stability in the solid state.

Nickel‐Catalyzed Inter‐ and Intramolecular Aryl Thioether Metathesis by Reversible Arylation

By Tristan Delcaillau, Alessandro Bismuto, Zhong Lian, Bill Morandi from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Ch‐ch‐change S: A nickel‐catalyzed aryl thioether metathesis with high functional‐group tolerance was developed, with bis(dicyclohexylphosphino)ethane (dcype) being essential to promote the reaction. Synthetically challenging macrocycles were obtained in good yield in an unusual example of ring‐closing metathesis that does not involve alkene bonds. In‐depth organometallic studies support a reversible Ni0/NiII pathway to product formation. Abstract A nickel‐catalyzed aryl thioether metathesis has been developed to access high‐value thioethers. 1,2‐Bis(dicyclohexylphosphino)ethane (dcype) is essential to promote this highly functional‐group‐tolerant reaction. Furthermore, synthetically challenging macrocycles could be obtained in good yield in an unusual example of ring‐closing metathesis that does not involve alkene bonds. In‐depth organometallic studies support a reversible Ni0/NiII pathway to product formation. Overall, this work not only provides a more sustainable alternative to previous catalytic systems based on Pd, but also presents new applications and mechanistic information that are highly relevant to the further development and application of unusual single‐bond metathesis reactions.

Effective Utilization of NIR Wavelengths for Photo‐Controlled Polymerization: Penetration Through Thick Barriers and Parallel Solar Syntheses

By Zilong Wu, Kenward Jung, Cyrille Boyer from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Walking on sunshine: An efficient far‐red‐ and NIR‐light‐mediated RAFT photopolymerization utilizing phthalocyanines as a photosensitizer is presented. The use of longer wavelengths permits polymerization by irradiating through barriers. Furthermore, long wavelength photochemistry may be used in conjunction with existing photocatalysts to enable more optimized usage of solar irradiation for chemical syntheses. Abstract This contribution details an efficient and controlled photopolymerization regulated by far‐red (λ=680 nm) and NIR (λ=780 and 850 nm) light in the presence of aluminium phthalocyanine and aluminium naphthalocyanine. Initiating radicals are generated by photosensitization of peroxides affording an effective strategy that provides controlled polymerization of a variety of monomers with excellent living characteristics. Critically, long wavelength irradiation provides penetration through thick barriers, affording unprecedented rates of controlled polymerization that can open new and exciting applications. Furthermore, a more optimized approach to performing solar syntheses is presented. By combining the narrow Q‐bands of these photocatalysts with others possessing complementary absorptions, layered, independent polymerizations and organic transformations may be performed in parallel under a single broadband emission source, such as sunlight.

Highly Acidic Conjugate‐Base‐Stabilized Carboxylic Acids Catalyze Enantioselective oxa‐Pictet–Spengler Reactions with Ketals

By Zhengbo Zhu, Minami Odagi, Chenfei Zhao, Khalil A. Abboud, Helmi Ulrika Kirm, Jaan Saame, Märt Lõkov, Ivo Leito, Daniel Seidel from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A chiral carboxylic acid catalyst exerts control over asymmetric cyclizations of acyclic ketone‐derived trisubstituted oxocarbenium ions, thereby providing access to highly enantioenriched dihydropyran products containing a tetrasubstituted stereogenic center. The high acidity of the carboxylic acid catalyst is largely derived from stabilization of the carboxylate conjugate base through intramolecular anion‐binding to a thiourea site. Abstract Acyclic ketone‐derived oxocarbenium ions are involved as intermediates in numerous reactions that provide valuable products, however, they have thus far eluded efforts aimed at asymmetric catalysis. We report that a readily accessible chiral carboxylic acid catalyst exerts control over asymmetric cyclizations of acyclic ketone‐derived trisubstituted oxocarbenium ions, thereby providing access to highly enantioenriched dihydropyran products containing a tetrasubstituted stereogenic center. The high acidity of the carboxylic acid catalyst, which exceeds that of the well‐known chiral phosphoric acid catalyst TRIP, is largely derived from stabilization of the carboxylate conjugate base through intramolecular anion‐binding to a thiourea site.

Photochemical Carbopyridylation of Alkenes Using N‐Alkenoxypyridinium Salts as Bifunctional Reagents

By Gangadhar Rao Mathi, Yujin Jeong, Yonghoon Moon, Sungwoo Hong from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

On the double: Visible‐light‐induced carbopyridylation of alkenes has been achieved using N‐alkenoxypyridinium salts as both α‐carbonyl radical precursors and pyridine sources. Regioselective addition of an α‐carbonyl radical onto an olefin followed by pyridylation led to the introduction of two valuable chemical entities in an atom‐economical fashion to eventually provide synthetically useful γ‐pyridyl ketones. Abstract N‐Alkenoxypyridinium salts have been used as synthons for the umpolung reaction of enolates for the preparation of α‐functionalized carbonyl compounds. In contrast, we found that the photoreduction of N‐alkenoxypyridinium salts generates α‐carbonyl radicals after cleavage of the N−O bond, thereby allowing simultaneous incorporation of α‐keto and pyridyl groups across unactivated alkenes. In the process, the formed α‐carbonyl radicals engage unactivated alkenes to afford alkyl radical intermediates poised for subsequent addition to pyridinium salts, which ultimately affords a variety of γ‐pyridyl ketones under mild reaction conditions. This transformation is characterized by a broad substrate scope and good functional‐group compatibility, and the utility of this transformation was further demonstrated by the late‐stage functionalization of complex biorelevant molecules.

Organic–Inorganic Copolymerization for a Homogenous Composite without an Interphase Boundary

By Yadong Yu, Zhao Mu, Biao Jin, Zhaoming Liu, Ruikang Tang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Organic and inorganic copolymerization by using acrylamide monomers and calcium phosphate oligomers as precursors results in an organic–inorganic composite without an interphase boundary. The material features significant mechanical enhancements that are due to the unique advantage of the homogenous composite structure. Abstract Ionic oligomers and their crosslinking implies a possibility to produce novel organic–inorganic composites by copolymerization. Using organic acrylamide monomers and inorganic calcium phosphate oligomers as precursors, uniformly structured polyacrylamide (PAM)‐calcium phosphate copolymer is prepared by an organic–inorganic copolymerization. In contrast to the previous PAM‐based composites by mixing inorganic components into polymers, the copolymerized material has no interphase boundary owing to the homogenous incorporation of the organic and inorganic units at molecular level, resulting in a complete and continuous hybrid network. The participation of the ionic binding effect in the crosslinking process can substantially improve the mechanical strength; the copolymer can reach a modulus and hardness of 35.14±1.91 GPa and 1.34±0.09 GPa, respectively, which are far superior to any other PAM‐based composites.

Amidation, Esterification, and Thioesterification of a Carboxyl‐Functionalized Covalent Organic Framework

By Lei Guo, Shang Jia, Christian S. Diercks, Xuejing Yang, Sultan A. Alshmimri, Omar M. Yaghi from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Versatile platform: A novel highly crystalline two‐dimensional covalent organic framework (COF) bearing pre‐installed carboxyl groups is reported. The carboxylic acids enable facile post‐synthetic modification by amidation, esterification, and thioesterfication for introduction of virtually any functionality to the framework. Abstract Three new post‐synthetic modification reactions, namely amidation, esterification, and thioesterification, were demonstrated on a novel highly crystalline two‐dimensional covalent organic framework (COF), COF‐616, bearing pre‐installed carboxyl groups. The strategy can be used to introduce a large variety of functional groups into COFs and the modifications can be carried out under mild reaction conditions, with high yields, and an easy work‐up protocol. As a proof of concept, various chelating functionalities were successfully incorporated into COF‐616 to yield a family of adsorbents for efficient removal of several contaminants in the water.

A Light‐Triggerable Nanoparticle Library for the Controlled Release of Non‐Coding RNAs

By Josephine Blersch, Vitor Francisco, Catarina Rebelo, Adrian Jiménez‐Balsa, Helena Antunes, Carlo Gonzato, Sandra Pinto, Susana Simões, Klaus Liedl, Karsten Haupt, Lino Ferreira from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A light‐sensitive nanoparticle library was synthesized to deliver non‐coding RNAs. Six formulations were more efficient (up to 500 %) than commercially available lipofectamine in gene‐knockdown activity. These formulations showed differential internalization by skin cells and the endosomal escape was rapid (minutes range). The utility of these light‐triggerable nanoparticles was demonstrated in the context of wound healing. Abstract RNA‐based therapies offer a wide range of therapeutic interventions including the treatment of skin diseases; however, the strategies to efficiently deliver these biomolecules are still limited due to obstacles related to the cellular uptake and cytoplasmic delivery. Herein, we report the synthesis of a triggerable polymeric nanoparticle (NP) library composed of 160 formulations, presenting physico‐chemical diversity and differential responsiveness to light. Six formulations were more efficient (up to 500 %) than commercially available lipofectamine in gene‐knockdown activity. These formulations showed differential internalization by skin cells and the endosomal escape was rapid (minutes range). The NPs were effective in the release of siRNA and miRNA. Acute skin wounds treated with the top hit NP complexed with miRNA‐150‐5p healed faster than wounds treated with scrambled miRNA. Light‐activatable NPs offer a new strategy to topically deliver non‐coding RNAs.

Efficient Heterogeneous Palladium‐Catalyzed Oxidative Cascade Reactions of Enallenols to Furan and Oxaborole Derivatives

By Man‐Bo Li, Daniels Posevins, Antoine Geoffroy, Can Zhu, Jan‐E. Bäckvall from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Heterogeneous ligand: A highly efficient heterogeneous palladium‐catalyzed oxidative cyclization of enallenols is developed here for the construction of highly substituted furan and oxaborole derivatives. The support (AmP‐MCF) of the heterogeneous catalyst (Pd‐AmP‐MCF) protect Pd species from aggregating to Pd black during the catalytic cycle, which leads to the high Pd efficiency of Pd‐AmP‐MCF. Abstract A heterogeneous palladium‐catalyzed oxidative cyclization of enallenols has been developed for the construction of highly substituted furan and oxaborole derivatives. The heterogeneous catalyst (Pd‐AmP‐MCF) exhibits high activity, high site‐ and stereoselectivity, and efficient palladium recyclability in the transformations.

Site‐Selective, Modular Diversification of Polyhalogenated Aryl Fluorosulfates (ArOSO2F) Enabled by an Air‐Stable PdI Dimer

By Marvin Mendel, Indrek Kalvet, Daniel Hupperich, Guillaume Magnin, Franziska Schoenebeck from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Diversity: The rapid, modular, substrate‐independent and fully predictable functionalization of polysubstituted arenes bearing C−OSO2F, C−Br, and C−Cl sites at room temperature is showcased. In this way the arene unit can be functionalized in the presence of a fluorosulfate group or the latter can serve as a triflate surrogate. Abstract Since 2014, the interest in aryl fluorosulfates (ArOSO2F) as well as their implementation in powerful applications has continuously grown. In this context, the enabling capability of ArOSO2F will strongly depend on the substitution pattern of the arene, which ultimately dictates its overall function as drug candidate, material, or bio‐linker. This report showcases the modular, substrate‐independent, and fully predictable, selective functionalization of polysubstituted arenes bearing C−OSO2F, C−Br, and C−Cl sites, which makes it possible to diversify the arene in the presence of OSO2F or utilize OSO2F as a triflate surrogate. Sequential and triply selective arylations and alkylations were realized within minutes at room temperature, using a single and air‐stable PdI dimer.

Low‐Temperature Synthesis of Honeycomb CuP2@C in Molten ZnCl2 Salt for High‐Performance Lithium Ion Batteries

By Zhiliang Liu, Shaolei Yang, Bingxue Sun, Piaoping Yang, Jie Zheng, Xingguo Li from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A low‐temperature method is used to synthesize honeycomb‐like phosphorus‐rich CuP2@C nanostructure for high‐performance lithium‐ion batteries through PCl3 reduction and in situ phosphorization of MOF derived Cu@C. Simultaneous reduction of PCl3 and SnCl4 on a mechanically activated Na surface and in situ combination into phosphide has a high phosphorizing efficiency and good control of Sn4P3 nucleation size. Abstract Phosphorus‐rich metal phosphides have very high lithium storage capacities, but they are difficult to prepare. A low‐temperature phosphorization method based on Mg reducing PCl3 in ZnCl2 molten salt at 300 °C is developed to synthesize phosphorus‐rich CuP2@C from a Cu‐MOF derived Cu@C composite. Abnormal oxidation of Cu by Zn2+ in the molten salt is observed, which leads to the porous honeycomb nanostructure and homogeneously distributed ultrafine CuP2 nanocrystals. The honeycomb CuP2@C exhibits excellent lithium storage performance with high reversible capacity (1146 mAh g−1 at 0.2 A g−1) and superior cycling stability (720 mAh g−1 after 600 cycles at 1.0 A g−1), showing the promising application of P‐rich metal phosphides in lithium ion batteries.

A Stable Cyclic (R2SnAu)3 Anion Having In‐Plane σ‐Möbius Aromaticity

By Liliang Wang, Jian Xu, Mitsuo Kira, Liping Yan, Xu‐Qiong Xiao, Zhifang Li from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A cyclic (R2SnAu)3 anion has been synthesized as a stable blue salt with K+(THF)6 by reaction of a dialkylstannylene with R′3PAuCl (R′=Et, Ph) and reduction with KC8. The six‐membered (SnAu)3 ring is planar and highly symmetric. Whereas cyclic Au3− with four valence electrons is an unstable anti‐aromatic anion, the (R2SnAu)3 anion with three divalent tin ligands is a stable σ aromatic anion with an unprecedented Möbius orbital array. Abstract A cyclic (R2SnAu)3 anion (3−, R2Sn=2,2,5,5‐tetrakis(trimethylsilyl)‐1‐stannacyclopentane‐1,1‐diyl) has been synthesized as a stable blue salt with K+(THF)6 through the reaction of stable dialkylstannylene 1 with R′3PAuCl (R′=Et, Ph) followed by the reduction with KC8. Crystallographic and NMR analysis shows that the six‐membered (SnAu)3 ring of 3− is planar and highly symmetric with an equal distance of six Au−Sn bonds. A UV/Vis spectrum of 3− in hexane reveals an intense absorption maximum at 598 nm. While cyclic Au3− with four valence electrons is known as unstable anti‐aromatic anion, 3− with three divalent tin ligands is stable σ aromatic anion with an unprecedented Möbius orbital array as predicted by the perturbation MO and CCSD analysis of 3−.

Dodecatwistarene Imides with Zigzag‐Twisted Conformation for Organic Electronics

By Guogang Liu, Chengyi Xiao, Fabrizia Negri, Yan Li, Zhaohui Wang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

1D nonplanar graphene nanoribbon, namely dodecatwistarene imide featuring twelve linearly fused benzene rings, was obtained by Pd‐catalyzed Stille coupling and C−H activation. It has a zigzag‐twisted conformation with the pendulum angle of 53°, and is very stable even when heated up to 250 °C. An organic field‐effect transistor based on it exhibits electron mobility up to 1.5 cm2 V−1 s−1. Abstract 1D nonplanar graphene nanoribbons generally have three possible conformers: helical, zigzag, and mixed conformations. Now, a kind of 1D nonplanar graphene nanoribbon, namely dodecatwistarene imides featuring twelve linearly fused benzene rings, was obtained by bottom‐up synthesis of palladium‐catalyzed Stille coupling and C−H activation. Single‐crystal X‐ray diffraction analyses revealed that it displays a zigzag‐twisted conformation caused by steric hindrance between imide groups and neighboring annulated benzene rings with the pendulum angle of 53°. This conformation is very stable and could not convert into other conformations even when heated up to 250 °C for 6 h. Despite of the highly twisted topology, organic field‐effect transistor based on it exhibits electron mobility up to 1.5 cm2 V−1 s−1 after annealing.

Copper‐Catalyzed Enantioselective Allylic Alkylation with a γ‐Butyrolactone‐Derived Silyl Ketene Acetal

By Carina I. Jette, Z. Jaron Tong, Ryan G. Hadt, Brian M. Stoltz from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A Cu‐catalyzed enantioselective allylic alkylation using a γ‐butyrolactone‐derived silyl ketene acetal as a nucleophile is reported. Critical to the development of this work was the identification of a novel mono‐picolinamide ligand with the appropriate steric and electronic properties to afford the desired alkylation products in high yields and high levels of enantiomeric excess. Abstract Herein, we report a Cu‐catalyzed enantioselective allylic alkylation using a γ‐butyrolactone‐derived silyl ketene acetal. Critical to the development of this work was the identification of a novel mono‐picolinamide ligand with the appropriate steric and electronic properties to afford the desired products in high yield (up to 96 %) and high ee (up to 95 %). Aryl, aliphatic, and unsubstituted allylic chlorides bearing a broad range of functionality are well‐tolerated. Spectroscopic studies reveal that a CuI species is likely the active catalyst, and DFT calculations suggest ligand sterics play an important role in determining Cu coordination and thus catalyst geometry.

Palladium‐Catalyzed Enantioselective Cacchi Reaction: Asymmetric Synthesis of Axially Chiral 2,3‐Disubstituted Indoles

By Yu‐Ping He, Hua Wu, Qian Wang, Jieping Zhu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Axially chiral indoles: In the presence of a chiral QuinoxP*PdII complex, two simple achiral building blocks undergo cyclizative cross‐coupling to afford 2,3‐disubstituted indoles bearing a C2‐aryl chiral axis in high yields and enantioselectivity. The indole ring is constructed de novo in this process and a complexation‐induced chirality transfer is proposed to account for the observed enantioselectivity. Abstract We report herein the first examples of a palladium‐catalyzed enantioselective Cacchi reaction for the synthesis of indoles bearing a chiral C2‐aryl axis. In the presence of a catalytic amount of Pd(OAc)2 and (R,R)‐QuinoxP* ligand, reaction of N‐aryl(alkyl)sulfonyl‐2‐alkynylanilides with arylboronic acids under oxygen atmosphere afforded enantioenriched 2,3‐disubstituted indoles in high yields and enantioselectivity. The indole ring is constructed de novo in this process and a complexation‐induced chirality transfer is proposed to account for the observed enantioselectivity.

The Chemical Potential of Plasmonic Excitations

By Sungju Yu, Prashant K. Jain from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Shine a light: In photoredox reactions driven by localized surface plasmon resonances, plasmonic excitations contribute a chemical potential. This chemical potential depends on the concentration (intensity) of the light. Abstract By the photoexcitation of localized surface plasmon resonances of metal nanoparticles, one can generate reaction equivalents for driving redox reactions. We show that, in such cases, there is a chemical potential contributed by the plasmonic excitation. This chemical potential is a function of the concentration of light, as we determine from the light‐intensity‐dependent activity in the plasmon‐excitation‐driven reduction of CO2 on Au nanoparticles. Our finding allows the treatment of plasmonic excitation as a reagent in chemical reactions; the chemical potential of this reagent is tunable by the light intensity.

Microporosity of a Guanidinium Organodisulfonate Hydrogen‐Bonded Framework

By Ivana Brekalo, David E. Deliz, Leonard J. Barbour, Michael D. Ward, Tomislav Friščić, K. Travis Holman from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Pores now found! The porous polymorph of guanidinium 1,4‐benzenedisulfonate, G2BDS, one of the simplest members of an archetypal class of hydrogen‐bonded frameworks, was prepared from its acetone solvate by single‐crystal‐to‐single‐crystal (SC‐SC) desolvation. The persistent porosity, phase behavior, and gas sorption characteristics are described. Abstract Guanidinium organosulfonates (GSs) are a large and well‐explored archetypal family of hydrogen‐bonded organic host frameworks that have, over the past 25 years, been regarded as nonporous. Reported here is the only example to date of a conventionally microporous GS host phase, namely guanidinium 1,4‐benzenedisulfonate (p‐G2BDS). p‐G2BDS is obtained from its acetone solvate, AcMe@G2BDS, by single‐crystal‐to‐single‐crystal (SC‐SC) desolvation, and exhibits a Type I low‐temperature/pressure N2 sorption isotherm (SABET=408.7(2) m2 g−1, 77 K). SC‐SC sorption of N2, CO2, Xe, and AcMe by p‐G2BDS is explored under various conditions and X‐ray diffraction provides a measurement of the high‐pressure, room temperature Xe and CO2 sorption isotherms. Though p‐G2BDS is formally metastable relative to the “collapsed”, nonporous polymorph, np‐G2BDS, a sample of p‐G2BDS survived for almost two decades under ambient conditions. np‐G2BDS reverts to zCO2@p‐G2BDS or yXe@p‐G2BDS (y,z=variable) when pressure of CO2 or Xe, respectively, is applied.

Enriched Surface Oxygen Vacancies of Photoanodes by Photoetching with Enhanced Charge Separation

By Shijia Feng, Tuo Wang, Bin Liu, Congling Hu, Lulu Li, Zhi‐Jian Zhao, Jinlong Gong from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Surface oxygen vacancies play a significant role in BiVO4 photoanodes during the solar water splitting. Photoetching effectively introduce the surface oxygen vacancies on BiVO4 photoanodes, which enhances the charge separation at the BiVO4/electrolyte interface. Abstract A facile photoetching approach is described that alleviates the negative effects from bulk defects by confining the oxygen vacancy (Ovac) at the surface of BiVO4 photoanode, by 10‐minute photoetching. This strategy could induce enriched Ovac at the surface of BiVO4, which avoids the formation of excessive bulk defects. A mechanism is proposed to explain the enhanced charge separation at the BiVO4 /electrolyte interface, which is supported by density functional theory (DFT) calculations. The optimized BiVO4 with enriched surface Ovac presents the highest photocurrent among undoped BiVO4 photoanodes. Upon loading FeOOH/NiOOH cocatalysts, photoetched BiVO4 photoanode reaches a considerable water oxidation photocurrent of 3.0 mA cm−2 at 0.6 V vs. reversible hydrogen electrode. An unbiased solar‐to‐hydrogen conversion efficiency of 3.5 % is realized by this BiVO4 photoanode and a Si photocathode under 1 sun illumination.

Catalytic Stereoselective Borylative Transannular Reactions

By Jana Sendra, Ruben Manzano, Efraim Reyes, Jose L. Vicario, Elena Fernández from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Copper‐catalyzed conjugate borylation can be used to trigger highly diastereoselective and enantioselective transannular reactions that enable the construction of complex bicyclic scaffolds. Abstract Medium‐sized carbocycles containing an α,β‐unsaturated ketone moiety as Michael acceptor site and a ketone moiety as internal electrophilic site are ideal substrates to conduct Cu(I)‐catalyzed conjugated borylation followed by electrophilic intramolecular trapping that results into a pioneer transannular borylative ring closing reaction. The relative configuration of three adjacent stereocenters is controlled, giving access to a single diastereoisomer for a wide range of substrates tested. Moreover, when a chiral ligand is incorporated, the reaction provides enantioenriched polycyclic products with up to 99 % ee.

Site‐Selective Late‐Stage Aromatic [18F]Fluorination via Aryl Sulfonium Salts

By Peng Xu, Da Zhao, Florian Berger, Aboubakr Hamad, Jens Rickmeier, Roland Petzold, Mykhailo Kondratiuk, Kostiantyn Bohdan, Tobias Ritter from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A broadly applicable and site‐selective late‐stage aromatic [18F]fluorination reaction is reported. A collection of three electronically different dibenzothiophenes enables 18F labeling of a series of small complex molecules. Abstract Site‐selective functionalization of C−H bonds in small complex molecules is a long‐standing challenge in organic chemistry. Herein, we report a broadly applicable and site‐selective aromatic C−H dibenzothiophenylation reaction. The conceptual advantage of this transformation is further demonstrated through the two‐step C−H [18F]fluorination of a series of marketed small‐molecule drugs.

Self‐Stabilized and Strongly Adhesive Supramolecular Polymer Protective Layer Enables Ultrahigh‐Rate and Large‐Capacity Lithium‐Metal Anode

By Gang Wang, Chao Chen, Yunhua Chen, Xiongwu Kang, Chenghao Yang, Fei Wang, Yong Liu, Xunhui Xiong from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Stick with it: An adhesive and self‐healable supramolecular copolymer, comprising of pendant poly(ethylene oxide) segments and ureido‐pyrimidinone (Upy) hydrogen‐bonding moieties, has been developed and employed as a protection layer of a Li anode. This layer is self‐stabilizing because of a spontaneous reaction between the UPy groups and Li, enabling dendrite‐free cycling at a high areal capacity and current density. Abstract Constructing a solid electrolyte interface (SEI) is a highly effective approach to overcome the poor reversibility of lithium (Li) metal anodes. Herein, an adhesive and self‐healable supramolecular copolymer, comprising of pendant poly(ethylene oxide) (PEO) segments and ureido‐pyrimidinone (UPy) quadruple‐hydrogen‐bonding moieties, is developed as a protection layer of Li anode by a simple drop‐coating. The protection performance of in‐situ‐formed LiPEO–UPy SEI layer is significantly enhanced owing to the strong binding and improved stability arising from a spontaneous reaction between UPy groups and Li metal. An ultrathin (approximately 70 nm) LiPEO–UPy layer can contribute to stable and dendrite‐free cycling at a high areal capacity of 10 mAh cm−2 at 5 mA cm−2 for 1000 h. This coating together with the promising electrochemical performance offers a new strategy for the development of dendrite‐free metal anodes.

Sequence‐Dependent Stereodivergent Allylic Alkylation/Fluorination of Acyclic Ketones

By Xi‐Jia Liu, Shicheng Jin, Wen‐Yun Zhang, Qiang‐Qiang Liu, Chao Zheng, Shu‐Li You from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Four of a kind: α‐Pyridyl‐α‐fluoroketones with vicinal tertiary and quaternary stereocenters were synthesized efficiently from α‐pyridylketones by asymmetric allylation and electrophilic fluorination. All four possible stereoisomers of the products were prepared from the same starting materials by simply adjusting the reaction sequence of asymmetric allylic alkylation and fluorination and varying the absolute configuration of the Ir catalyst (see scheme). Abstract The stereodivergent iridium‐catalyzed allylic alkylation and fluorination of acyclic ketones is described. α‐Pyridyl‐α‐fluoroketones with vicinal tertiary and quaternary stereocenters were obtained in moderate to excellent yields and stereoselectivities. Distinct from known stereodivergent synthesis, for which two different chiral catalysts are required in general, herein we report a sequence‐dependent stereodivergent synthesis. With only a single chiral Ir catalyst, all four possible stereoisomers of the products were prepared from the same starting materials by simply adjusting the sequence of asymmetric allylic alkylation and fluorination and varying the absolute configuration of the Ir catalyst.

Controlled Synthesis of a Vacancy‐Defect Single‐Atom Catalyst for Boosting CO2 Electroreduction

By Xin Rong, Hong‐Juan Wang, Xiu‐Li Lu, Rui Si, Tong‐Bu Lu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A vacancy defect was controllably constructed at the Ni site in a nickel single‐atom catalyst. It shows significantly enhanced electrocatalytic activity and selectivity for CO2‐to‐CO conversion compared with the Ni‐N4 catalyst. Abstract The reaction of precursors containing both nitrogen and oxygen atoms with NiII under 500 °C can generate a N/O mixing coordinated Ni‐N3O single‐atom catalyst (SAC) in which the oxygen atom can be gradually removed under high temperature due to the weaker Ni−O interaction, resulting in a vacancy‐defect Ni‐N3‐V SAC at Ni site under 800 °C. For the reaction of NiII with the precursor simply containing nitrogen atoms, only a no‐vacancy‐defect Ni‐N4 SAC was obtained. Experimental and DFT calculations reveal that the presence of a vacancy‐defect in Ni‐N3‐V SAC can dramatically boost the electrocatalytic activity for CO2 reduction, with extremely high CO2 reduction current density of 65 mA cm−2 and high Faradaic efficiency over 90 % at −0.9 V vs. RHE, as well as a record high turnover frequency of 1.35×105 h−1, much higher than those of Ni‐N4 SAC, and being one of the best reported electrocatalysts for CO2‐to‐CO conversion to date.

Responsive Exosome Nano‐bioconjugates for Synergistic Cancer Therapy

By Weidong Nie, Guanghao Wu, Jinfeng Zhang, Li‐Li Huang, Jingjing Ding, Anqi Jiang, Yahui Zhang, Yanhong Liu, Jingchao Li, Kanyi Pu, Hai‐Yan Xie from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Ok, take a bite: Responsive exosome nano‐bioconjugates were constructed by engineering M1 exosomes with aCD47 and aSIRPα linked with a pH‐sensitive bond. After systemic administration, the synergism of specific targeting by aCD47, blocking of “don't eat me” signaling by aCD47 and aSIRPα, and M2 reprogramming by M1 exosomes resulted in a potent anticancer effect. Abstract Exosomes hold great potential in therapeutic development. However, native exosomes usually induce insufficient effects in vivo and simply act as drug delivery vehicles. Herein, we synthesize responsive exosome nano‐bioconjugates for cancer therapy. Azide‐modified exosomes derived from M1 macrophages are conjugated with dibenzocyclooctyne‐modified antibodies of CD47 and SIRPα (aCD47 and aSIRPα) through pH‐sensitive linkers. After systemic administration, the nano‐bioconjugates can actively target tumors through the specific recognition between aCD47 and CD47 on the tumor cell surface. In the acidic tumor microenvironment, the benzoic‐imine bonds of the nano‐bioconjugates are cleaved to release aSIRPα and aCD47 that can, respectively, block SIRPα on macrophages and CD47, leading to abolished “don't eat me” signaling and improved phagocytosis of macrophages. Meanwhile, the native M1 exosomes effectively reprogram the macrophages from pro‐tumoral M2 to anti‐tumoral M1.

Silaboration of [1.1.1]Propellane: A Storable Feedstock for Bicyclo[1.1.1]pentane Derivatives

By Masaki Kondo, Junichiro Kanazawa, Tomohiro Ichikawa, Takumi Shimokawa, Yuki Nagashima, Kazunori Miyamoto, Masanobu Uchiyama from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Silaboration of [1.1.1]propellane enabled direct introduction of B and Si functional groups onto the bicyclo[1.1.1]pentane (BCP) scaffold in high yield under mild, additive‐free conditions. The silaborated BCP can be obtained on a gram scale in a single step without the need for column chromatography purification, and is storable and easy to handle, providing a versatile synthetic intermediate for BCP derivatives. Abstract The silaboration of [1.1.1]propellane enables direct introduction of B and Si functional groups onto the bicyclo[1.1.1]pentane (BCP) scaffold in high yield under mild, additive‐free conditions. The silaborated BCP can be obtained on a gram‐scale in a single step without the need for column‐chromatographic purification, and is storable and easy to handle, providing a versatile synthetic intermediate for BCP derivatives. We also describe various conversions of the C−B/C−Si bonds on the BCP scaffold, including development of a modified Suzuki–Miyaura cross‐coupling reaction at the highly sterically hindered bridgehead sp3 carbon center of the BCP skeleton using a combination of highly activated BCP boronic esters, copper(I) oxide, and a PdCl2(dppf) catalyst system.

Thomas P. Russell

By from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

“My greatest achievement has been successfully introducing students to research and seeing the lightbulb come on in their heads. The most exciting thing about my research is pursuing the unknown …” Find out more about Thomas P. Russell in his Author Profile.

Simultaneous Optical Tuning of Hole and Electron Transport in Ambipolar WSe2 Interfaced with a Bicomponent Photochromic Layer: From High‐Mobility Transistors to Flexible Multilevel Memories

By Haixin Qiu, Zhaoyang Liu, Yifan Yao, Martin Herder, Stefan Hecht, Paolo Samorì from Wiley: Advanced Materials: Table of Contents. Published on Jan 24, 2020.

Optically switchable multilevel field‐effect transistors (FETs) based on 2D ambipolar WSe2 are realized by interfacing it with a bicomponent photochromic diarylethene blend. Electron and hole transport can be simultaneously modulated by remote light control. These FETs also show 126 distinct output current levels and are compatible to work on flexible substrates, demonstrating their potential for flexible multilevel nonvolatile memories. Abstract The interfacing of 2D materials (2DMs) with photochromic molecules provides an efficient solution to reversibly modulate their outstanding electronic properties and offers a versatile platform for the development of multifunctional field‐effect transistors (FETs). Herein, optically switchable multilevel high‐mobility FETs based on few‐layer ambipolar WSe2 are realized by applying on its surface a suitably designed bicomponent diarylethene (DAE) blend, in which both hole and electron transport can be simultaneously modulated for over 20 cycles. The high output current modulation efficiency (97% for holes and 52% for electrons) ensures 128 distinct current levels, corresponding to a data storage capacity of 7 bit. The device is also implemented on a flexible and transparent poly(ethylene terephthalate) substrate, rendering 2DM/DAE hybrid structures promising candidates for flexible multilevel nonvolatile memories.

Fri 31 Jan 13:00: Signatures of Modified Gravity in Black Hole Quasinormal Modes

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Signatures of Modified Gravity in Black Hole Quasinormal Modes

I will describe how signatures of modified gravity, in particular scalar tensor theories of gravity, can arise when studying black hole quasinormal modes. In particular I will look at black holes both with and without hair in Horndeski gravity, and discuss how we might constrain fundamental parameters of Horndeski theory through black hole spectroscopy.

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Mon 09 Mar 13:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Title to be confirmed

Abstract not available

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Mon 27 Jan 18:00: G I TAYLOR LECTURE - The Silent Flight of the Owl

From All Talks (aka the CURE list). Published on Jan 24, 2020.

G I TAYLOR LECTURE - The Silent Flight of the Owl

When hunting many, but not all, species of owl manage to fly almost silently in the audible frequency range of both themselves and their prey. A complete understanding of how this is done has yet to be found, but it is believed that three rather unusual features of the owl wing and feathers play a significant role. These features include a leading-edge comb of barbs, a porous and flexible trailing edge brush, and a particularly unusual microstructure in the feathers which leads to a velvet-like wing suction surface. Although the first feature is found on other raptors, the second two are quite unique to owls which hunt in acoustic stealth. In this talk I will describe a range of theoretical and experimental research which has been conducted to attempt to understand these mechanisms. It is well-known in other contexts, including aircraft landing noise and wind turbines, that a turbulent boundary layer passing over a wing trailing edge is a potentially potent source of noise, and so a particular focus of our work has been to investigate the ways in which the owl’s adaptations may have weakened this noise mechanism. An owl-inspired trailing-edge noise control device will be described.

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Axially Chiral TADF‐Active Enantiomers Designed for Efficient Blue Circularly Polarized Electroluminescence

By Meng Li, Yin‐Feng Wang, Dongdong Zhang, Lian Duan, Chuan‐Feng Chen from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Let′s twist again: Axially chiral molecules with thermally activated delayed fluorescence and circularly polarized electroluminescence (CPEL) are presented. CP‐OLEDs based on these molecules display high efficiencies and blue CPEL with large gEL values. Abstract The use of a chiral, emitting skeleton for axially chiral enantiomers showing activity in thermally activated delayed fluorescence (TADF) with circularly polarized electroluminescence (CPEL) is proposed. A pair of chiral stable enantiomers, (−)‐(S)‐Cz‐Ax‐CN and (+)‐(R)‐Cz‐Ax‐CN, was designed and synthesized. The enantiomers, both exhibiting intramolecular π‐conjugated charge transfer (CT) and spatial CT, show TADF activities with a small singlet–triplet energy difference (ΔEST) of 0.029 eV and mirror‐image circularly polarized luminescence (CPL) activities with large glum values. Notably, CP‐OLEDs based on the enantiomers feature blue electroluminescence centered at 468 nm with external quantum efficiencies (EQEs) of 12.5 and 12.7 %, and also show intense CPEL with gEL values of −1.2×10−2 and +1.4×10−2, respectively. These are the first CP‐OLEDs based on TADF‐active enantiomers with efficient blue CPEL.

Enantiomorphic Microvortex‐Enabled Supramolecular Sensing of Racemic Amino Acids by Using Achiral Building Blocks

By Yike Li, Chao Liu, Xuan Bai, Fei Tian, Guoqing Hu, Jiashu Sun from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Spin me round: An enantiomorphic microvortex‐enabled supramolecular sensing system for the quantitative detection of racemic or enantiomeric amino acids was developed. The system has unique advantages including straightforward operation, rapid detection, and no use of chiral additives. Abstract Chiral analysis of bioactive molecules is of increasing significance in chemical and life sciences. However, the quantitative detection of a racemic mixture of enantiomers is a challenging task, which relies on complicated and time‐consuming multiple steps of chiral derivatization, chiral separation, and spectroscopic measurement. Herein, we show that, without the use of chiral molecules or pretreatment steps, the co‐assembly of amino acids with achiral TPPS4 monomers controlled by enantiomorphic microvortices allows quantitative detection of racemic or enantiomeric amino acids, through analysis of the sign and magnitude of supramolecular chirality in different outlets of a microfluidic platform. A model demonstrates that chiral microvortices can induce an initial chiral bias by bending the sheet structure, resulting in supramolecular self‐assembly of TPPS4 and amino acids of compatible chirality by the self‐sorting. This sensing system may find versatile applications in chiral sensing.

Synthesis of Axially Chiral Biaryl‐2‐amines by PdII‐Catalyzed Free‐Amine‐Directed Atroposelective C−H Olefination

By Bei‐Bei Zhan, Lei Wang, Jun Luo, Xu‐Feng Lin, Bing‐Feng Shi from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A free amine group can be used as a directing group to synthesize axially chiral biaryl compounds by a PdII‐catalyzed atroposelective C−H olefination. Good yields and high enantioselectivities (up to 97 % ee) can be achieved by using chiral spiro phosphoric acid (SPA) as an efficient ligand. The amount of ligand can be reduced to 1 mol % without loss of enantiocontrol in a gram‐scale synthesis. Abstract A simple and ubiquitously present group, free amine, is used as a directing group to synthesize axially chiral biaryl compounds by PdII‐catalyzed atroposelective C−H olefination. A broad range of axially chiral biaryl‐2‐amines can be obtained in good yields with high enantioselectivities (up to 97 % ee). Chiral spiro phosphoric acid (SPA) proved to be an efficient ligand and the loading could be reduced to 1 mol % without erosion of enantiocontrol in gram‐scale synthesis. The resulting axially chiral biaryl‐2‐amines also provide a platform for the synthesis of a set of chiral ligands.

A Hexagonal Planar Metal Complex

By Michael E. Tauchert, Jun Okuda from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Flattened: A six‐coordinate [ML3Z3]‐type transition‐metal complex with a hexagonal planar geometry has been isolated and characterized, extending the scope of six‐coordinate metal coordination compounds to those with a geometry beyond octahedral and trigonal prismatic. Abstract A six‐coordinate [ML3Z3]‐type transition‐metal complex with a hexagonal planar geometry has been isolated and characterized, extending the scope of six‐coordinate metal coordination compounds to those with a geometry beyond octahedral and trigonal prismatic.

Boron‐Induced Electronic‐Structure Reformation of CoP Nanoparticles Drives Enhanced pH‐Universal Hydrogen Evolution

By Erping Cao, Zhimin Chen, Hao Wu, Peng Yu, Ying Wang, Fei Xiao, Shuo Chen, Shichao Du, Ying Xie, Yiqun Wu, Zhiyu Ren from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

The importance of B in HERnest: Boron is introduced into CoP nanoparticles anchored on carbon nanotubes to form a robust pH‐universal hydrogen evolution reaction (HER) catalyst. The boron has a relatively low electronegativity and refines the electronic structure of the CoP catalytic sites, thus enhances the electrical conductivity and optimizes the free energy of H adsorption, leading to improved electrocatalytic H2 production. Abstract Even though transition‐metal phosphides (TMPs) have been developed as promising alternatives to Pt catalyst for the hydrogen evolution reaction (HER), further improvement of their performance requires fine regulation of the TMP sites related to their specific electronic structure. Herein, for the first time, boron (B)‐modulated electrocatalytic characteristics in CoP anchored on the carbon nanotubes (B‐CoP/CNT) with impressive HER activities over a wide pH range are reported. The HER performance surpasses commercial Pt/C in both neutral and alkaline media at large current density (>100 mA cm−2). A combined experimental and theoretical study identified that the B dopant could reform the local electronic configuration and atomic arrangement of bonded Co and adjacent P atoms, enhance the electrons’ delocalization capacity of Co atoms for high electrical conductivity, and optimize the free energy of H adsorption and H2 desorption on the active sites for better HER kinetics.

Surface Engineering of g‐C3N4 by Stacked BiOBr Sheets Rich in Oxygen Vacancies for Boosting Photocatalytic Performance

By Dongni Liu, Dongyun Chen, Najun Li, Qingfeng Xu, Hua Li, Jinghui He, Jianmei Lu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

BiOBr nanoflowers, sheet‐stacked and rich in oxygen vacancies, are prepared by a simple solvothermal process and form a heterojunction with graphitic carbon nitride. Oxygen vacancies and the heterojunction synergistically promote photocatalysis, achieving a NO degradation effect of 63 % and 96 % selectivity of carbonaceous products for CO2 conversion. Abstract BiOBr containing surface oxygen vacancies (OVs) was prepared by a simple solvothermal method and combined with graphitic carbon nitride (g‐C3N4) to construct a heterojunction for photocatalytic oxidation of nitric oxide (NO) and reduction of carbon dioxide (CO2). The formation of the heterojunction enhanced the transfer and separation efficiency of photogenerated carriers. Furthermore, the surface OVs sufficiently exposed catalytically active sites, and enabled capture of photoexcited electrons at the surface of the catalyst. Internal recombination of photogenerated charges was also limited, which contributed to generation of more active oxygen for NO oxidation. Heterojunction and OVs worked together to form a spatial conductive network framework, which achieved 63 % NO removal, 96 % selectivity for carbonaceous products (that is, CO and CH4). The stability of the catalyst was confirmed by cycling experiments and X‐ray diffraction and transmission electron microscopy after NO removal.

Hiroshi Kitagawa

By from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

“The secrets of being a successful scientist are dreams, imagination, and lots of effort. The biggest challenge facing scientists is the room‐temperature superconductor …” Find out more about Hiroshi Kitagawa in his Author Profile.

Generation and Reactivity of Amidyl Radicals: Manganese‐Mediated Atom‐Transfer Reaction

By Run‐Zhou Liu, Jinxia Li, Jun Sun, Xian‐Guan Liu, Shuanglin Qu, Ping Li, Bo Zhang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Out of the blue: A visible‐light‐driven manganese‐mediated protocol for generation of amidyl radicals from amines is described. This novel strategy enables site‐selective chlorination of unactivated C(sp3)−H bonds of aliphatic amines and intra/intermolecular chloroaminations of unactivated alkenes. These reactions feature a broad substrate scope, good functional‐group tolerance, and scalability. Abstract A simple and efficient protocol to generate amidyl radicals from amine functionalities through a manganese‐mediated atom‐transfer reaction has been developed. This approach employs an earth‐abundant and inexpensive manganese complex, Mn2(CO)10, as the catalyst and visible light as the energy input. Using this strategy, site‐selective chlorination of unactivated C(sp3)−H bonds of aliphatic amines and intramolecular/intermolecular chloroaminations of unactivated alkenes were readily realized under mild reaction conditions, thus providing efficient access to a range of synthetically valuable alkyl chlorides, chlorinated pyrrolidines, and vicinal chloroamine derivatives. These practical reactions exhibit a broad substrate scope and tolerate a wide array of functional groups, and complex molecules including various marketed drug derivatives.

O‐Doped Nanographenes: The Pyrano/Pyrylium Route Towards Semiconducting Cationic Mixed‐Valence Complexes

By Luka Ðorđević, Cataldo Valentini, Nicola Demitri, Cécile Mézière, Magali Allain, Marc Sallé, Andrea Folli, Damien Murphy, Samuel Mañas‐Valero, Eugenio Coronado, Davide Bonifazi from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

My O my! O‐doped nanographenes derived from the π‐extension of pyrene are reported. The compounds are highly fluorescent and feature low oxidation potentials. Electric measurements of single crystals of mixed‐valence salts show a semiconducting behavior with a remarkably high conductivity at room temperature. Abstract Herein we report an efficient synthesis to prepare O‐doped nanographenes derived from the π‐extension of pyrene. The derivatives are highly fluorescent and feature low oxidation potentials. Using electrooxidation, crystals of cationic mixed‐valence (MV) complexes were grown in which the organic salts organize into face‐to‐face π‐stacks, a favorable solid‐state arrangement for organic electronics. Variable‐temperature electron paramagnetic resonance (EPR) measurements and relaxation studies suggest a strong electron delocalization along the longitudinal axis of the columnar π‐stacking architectures. Electric measurements of single crystals of the MV salts show a semiconducting behavior with a remarkably high conductivity at room temperature. These findings support the notion that π‐extension of heteroatom‐doped polycyclic aromatic hydrocarbons is an attractive approach to fabricate nanographenes with a broad spectrum of semiconducting properties and high charge mobilities.

Exploiting the Bulk Photovoltaic Effect in a 2D Trilayered Hybrid Ferroelectric for Highly Sensitive Polarized Light Detection

By Yu Peng, Xitao Liu, Zhihua Sun, Chengmin Ji, Lina Li, Zhenyue Wu, Sasa Wang, Yunpeng Yao, Maochun Hong, Junhua Luo from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Seeing the light: The realization of BPVE‐driven polarized light detection in a two‐dimensional trilayered perovskite ferroelectric is presented. This material exhibits a super‐high polarization ratio. Abstract Polarized light detection is attracting increasing attention for its wide applications ranging from optical switches to high‐resolution photodetectors. Two‐dimensional (2D) hybrid perovskite‐type ferroelectrics combining inherent light polarization dependence of bulk photovoltaic effect (BPVE) with excellent semiconducting performance present significant possibilities. Now, the BPVE‐driven highly sensitive polarized light detection in a 2D trilayered hybrid perovskite ferroelectric, (allyammonium)2(ethylammonium)2Pb3Br10 (1), is presented. It shows a superior BPVE with near‐band gap photovoltage of ca. 2.5 V and high on/off switching ratio of current (ca. 104). Driven by the superior BPVE, 1 exhibits highly sensitive polarized light detection with a polarization ratio as high as ca. 15, which is far more beyond than those of structural anisotropy‐based monocomponent devices. This is the first realization of BPVE‐driven polarized light detection in hybrid perovskite ferroelectrics.

5,6,12,13‐Tetraazaperopyrenes as Unique Photonic and Mechanochromic Fluorophores

By Wei Yuan, Junjie Cheng, Xiaopei Li, Mengjiao Wu, Yi Han, Chunmei Yan, Gang Zou, Klaus Müllen, Yulan Chen from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Regioselective N‐doping of peropyrenes for fluorescent tailored microcrystals were achieved. 5,6,12,13‐tetraazaperopyrene derivatives were synthesized, the crystals of which showed excellent optical waveguide properties and exceptional mechanochromic fluorescence. Abstract 5,6,12,13‐Tetraazaperopyrenes with different number of tert‐butyl groups (c‐TAPP‐T, c‐TAPP‐H) were synthesized, via four‐fold Bischler–Napieralski cyclization as the key step. As deduced from the single‐crystal structures and optical properties, N‐doping and substitution type allow for a precise control of intermolecular interactions. Compared to the reported 1,3,8,10‐tetraazaperopyrenes, significantly different packing modes were found in 5,6,12,13‐tetraazaperopyrenes. Going from c‐TAPP‐T to c‐TAPP‐H, two additional tert‐butyl groups lead to different preferential growth directions, affording 1D and 2D microcrystals, respectively. Most importantly, both microcrystals exhibit excellent optical waveguide properties with extraordinarily low loss coefficients and unique polarization features. Although c‐TAPP‐H possesses a rigid and planar core, its crystals display an exceptional mechanochromic fluorescence, which, again, depends on the mode of molecular packing.

Artificial Light‐Harvesting Complexes Enable Rieske Oxygenase Catalyzed Hydroxylations in Non‐Photosynthetic cells

By F. Feyza Özgen, Michael E. Runda, Bastien O. Burek, Peter Wied, Jonathan Z. Bloh, Robert Kourist, Sandy Schmidt from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Illuminate me! The photoactivation of Rieske dioxygenases in the absence of glucose or any cofactor was successfully conducted using several photosensitizers for the bioconversion of three different substrates and hence this represents the first example of a photoinduced Rieske system. Abstract In this study, we coupled a well‐established whole‐cell system based on E. coli via light‐harvesting complexes to Rieske oxygenase (RO)‐catalyzed hydroxylations in vivo. Although these enzymes represent very promising biocatalysts, their practical applicability is hampered by their dependency on NAD(P)H as well as their multicomponent nature and intrinsic instability in cell‐free systems. In order to explore the boundaries of E. coli as chassis for artificial photosynthesis, and due to the reported instability of ROs, we used these challenging enzymes as a model system. The light‐driven approach relies on light‐harvesting complexes such as eosin Y, 5(6)‐carboxyeosin, and rose bengal and sacrificial electron donors (EDTA, MOPS, and MES) that were easily taken up by the cells. The obtained product formations of up to 1.3 g L−1 and rates of up to 1.6 mm h−1 demonstrate that this is a comparable approach to typical whole‐cell transformations in E. coli. The applicability of this photocatalytic synthesis has been demonstrated and represents the first example of a photoinduced RO system.

Substrate‐Independent Magnetic Bistability in Monolayers of the Single‐Molecule Magnet Dy2ScN@C80 on Metals and Insulators

By Denis S. Krylov, Sebastian Schimmel, Vasilii Dubrovin, Fupin Liu, T. T. Nhung Nguyen, Lukas Spree, Chia‐Hsiang Chen, Georgios Velkos, Claudiu Bulbucan, Rasmus Westerström, Michał Studniarek, Jan Dreiser, Christian Hess, Bernd Büchner, Stanislav M. Avdoshenko, Alexey A. Popov from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Monolayers of Dy2ScN@C80 exhibit magnetic hysteresis on Au, Ag, and MgO|Ag substrates. The substrates influence the ordering of the endohedral cluster, but does not affect the width of the hysteresis. The carbon cage protects the endohedral magnetic cluster and thus ensures that it sustains magnetic bistability. Abstract Magnetic hysteresis is demonstrated for monolayers of the single‐molecule magnet (SMM) Dy2ScN@C80 deposited on Au(111), Ag(100), and MgO|Ag(100) surfaces by vacuum sublimation. The topography and electronic structure of Dy2ScN@C80 adsorbed on Au(111) were studied by STM. X‐ray magnetic CD studies show that the Dy2ScN@C80 monolayers exhibit similarly broad magnetic hysteresis independent on the substrate used, but the orientation of the Dy2ScN cluster depends strongly on the surface. DFT calculations show that the extent of the electronic interaction of the fullerene molecules with the surface is increasing dramatically from MgO to Au(111) and Ag(100). However, the charge redistribution at the fullerene‐surface interface is fully absorbed by the carbon cage, leaving the state of the endohedral cluster intact. This Faraday cage effect of the fullerene preserves the magnetic bistability of fullerene‐SMMs on conducting substrates and facilitates their application in molecular spintronics.

Iron‐Catalyzed Direct Oxidative Alkylation and Hydroxylation of Indolin‐2‐ones with Alkyl‐Substituted N‐Heteroarenes

By Ren‐Ming Hu, Dong‐Yang Han, Ning Li, Jie Huang, Yu Feng, Da‐Zhen Xu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Iron clad: The direct alkylation and hydroxylation reaction between two different C(sp3)−H bonds, indolin‐2‐ones and alkyl‐substituted N‐heteroarenes, is reported. The reaction is catalyzed by a simple iron salt and employs air (molecular oxygen) as the terminal oxidant and oxygen source for the synthesis of O‐containing compounds, producing only water as the byproduct. Abstract Presented herein is the first direct alkylation and hydroxylation reaction between two different C(sp3)−H bonds, indolin‐2‐ones and alkyl‐substituted N‐heteroarenes, through an oxidative cross‐coupling reaction. The reaction is catalyzed by a simple iron salt under mild ligand‐free and base‐free conditions. The reaction is environmentally benign, employs air (molecular oxygen) as the terminal oxidant and oxygen source for the synthesis of O‐containing compounds, and produces only water as the byproduct.

Molybdenum Carbide‐Oxide Heterostructures: In Situ Surface Reconfiguration toward Efficient Electrocatalytic Hydrogen Evolution

By Liuqing He, Wenbiao Zhang, Qijie Mo, Wenjie Huang, Lichun Yang, Qingsheng Gao from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

In situ surface reconfiguration of Mo2C‐MoOx is uncovered for electrocatalytic hydrogen evolution. The benchmarking performance of Pt‐free electrocatalysts is reached through optimized hydrogen binding to Mo=O bonded Mo2C surfaces. Abstract Heterostructured Mo2C‐MoOx on carbon cloth (Mo2C‐MoOx/CC), as a model of easily oxidized electrocatalysts under ambient conditions, is investigated to uncover surface reconfiguration during the hydrogen evolution reaction (HER). Raman spectroscopy combined with electrochemical tests demonstrates that the MoVI oxides on the surface are in situ reduced to MoIV, accomplishing promoted HER in acidic condition. As indicated by density functional theoretical calculations, the in situ reduced surface with terminal Mo=O moieties can effectively bring the negative ΔGH* on bare Mo2C close to a thermodynamic neutral value, addressing difficult H* desorption toward fast HER kinetics. The optimized Mo2C‐MoOx/CC only requires a low overpotential (η10) of 60 mV at −10 mA cm−2 in 1.0 m HClO4, outperforming Mo2C/CC and most non‐precious electrocatalysts. In situ surface reconfiguration are shown on W2C‐WOx, highlighting the significance to boost various metal‐carbides and to identify active sites.

Stable Salts of Heteroleptic Iron Carbonyl/Nitrosyl Cations

By Jan Bohnenberger, Ingo Krossing from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Ready to use…! Two novel iron carbonyl/nitrosyl cations in the elusive oxidation state +I are now easily accessible as stable salts of the weakly coordinating anion [F‐{Al(ORF)3}2]−. They may serve as simple model systems for the investigation of the nature of the Fe−NO bond to further understand the (bio‐)chemistry of iron nitrosyl complexes. Abstract The oxidation of Fe(CO)5 with the [NO]+ salt of the weakly coordinating perfluoroalkoxyaluminate anion [F‐{Al(ORF)3}2]− (RF=C(CF3)3) leads to stable salts of the 18 valence electron (VE) species [Fe(CO)4(NO)]+ and [Fe(CO)(NO)3]+ with the Enemark–Feltham numbers of {FeNO}8 and {FeNO}10. This finally concludes the triad of heteroleptic iron carbonyl/nitrosyl complexes, since the first discovery of the anionic ([Fe(CO)3(NO)]−) and neutral ([Fe(CO)2(NO)2]) species over 80 years ago. Both complexes were fully characterized (IR, Raman, NMR, UV/Vis, scXRD, pXRD) and are stable at room temperature under inert conditions over months and may serve as useful starting materials for further investigations.

Dimensional Reduction of Cs2AgBiBr6: A 2D Hybrid Double Perovskite with Strong Polarization Sensitivity

By Yaobin Li, Tao Yang, Zhiyun Xu, Xitao Liu, Xiaoying Huang, Shiguo Han, Yi Liu, Maofan Li, Junhua Luo, Zhihua Sun from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

A lead‐free hybrid double perovskite, (i‐PA)2AgBiCsBr7, has been designed through dimensional reduction of the 3D prototype of Cs2AgBiBr6. Its unique quantum‐confined 2D bilayered motif results in the natural anisotropy of physical attributes, which accounts for its polarization‐sensitive response with large dichroic ratios. Abstract By dimensional reduction of the 3D motif of Cs2AgBiBr6, a lead‐free 2D hybrid double perovskite, (i‐PA)2CsAgBiBr7 (1, i‐PA=isopentylammonium), was successfully designed. It adopts a quantum‐confined bilayered structure with alternating organic and inorganic sheets. Strikingly, the unique 2D architecture endows it highly anisotropic nature of physical properties, including electric conductivity and optical absorption (the ratio αb/αc=1.9 at 405 nm). Such anisotropy attributes result in the strong polarization‐sensitive responses with large dichroic ratios up to 1.35, being comparable to some 2D inorganic materials. This is the first study on the hybrid double perovskites with strong polarization sensitivity. A crystal device of 1 also exhibits rapid response speed (ca. 200 μs) and excellent stabilities. The family of 2D hybrid double perovskites are promising optoelectronic candidates, and this work paves a new pathway for exploring new green polarization‐sensitive materials.

Image‐Based Morphological Profiling Identifies a Lysosomotropic, Iron‐Sequestering Autophagy Inhibitor

By Luca Laraia, Guillaume Garivet, Daniel J. Foley, Nadine Kaiser, Sebastian Müller, Sarah Zinken, Thomas Pinkert, Julian Wilke, Dale Corkery, Axel Pahl, Sonja Sievers, Petra Janning, Christoph Arenz, Yaowen Wu, Raphaël Rodriguez, Herbert Waldmann from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

I heard you paint cells: Morphological profiling using the “cell painting” assay revealed that autoquin impairs lysosomal integrity, iron homeostasis, and autophagy. Abstract Chemical proteomics is widely applied in small‐molecule target identification. However, in general it does not identify non‐protein small‐molecule targets, and thus, alternative methods for target identification are in high demand. We report the discovery of the autophagy inhibitor autoquin and the identification of its molecular mode of action using image‐based morphological profiling in the cell painting assay. A compound‐induced fingerprint representing changes in 579 cellular parameters revealed that autoquin accumulates in lysosomes and inhibits their fusion with autophagosomes. In addition, autoquin sequesters Fe2+ in lysosomes, resulting in an increase of lysosomal reactive oxygen species and ultimately cell death. Such a mechanism of action would have been challenging to unravel by current methods. This work demonstrates the potential of the cell painting assay to deconvolute modes of action of small molecules, warranting wider application in chemical biology.

Thu 20 Feb 18:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Title to be confirmed

Abstract not available

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Thu 20 Feb 18:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Title to be confirmed

Abstract not available

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Thu 06 Feb 13:00: Decoding Transcriptional Regulation and Kinetics Using Single-Cell Transcriptomics. Host: Michael Imbeault

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Decoding Transcriptional Regulation and Kinetics Using Single-Cell Transcriptomics.

The advancement of single-cell RNA -sequencing (scRNA-seq) has opened up for transcriptome-wide analyses of transcriptional regulation and dynamics. My lab developed full-length scRNA-seq protocols (e.g. Smart-seq2 and Smart-seq3) that we use to study patterns of gene expression and regulation at single cell resolution. We recently inferred transcriptional burst kinetics for thousands of endogenous genes using allele-resolved scRNA-seq, which revealed that core promoter elements and enhancers control burst size and frequency, respectively3. We have inferred allelic waiting times between consecutive bursts based on mRNA degradation rates that we are now comparing to direct readouts from 4sU-based labelling of newly transcribed RNAs in single cells4. Having transcriptome-wide readouts of bursting kinetics enables more detailed investigations into patterns of transcriptional dynamics in response to the perturbation of transcriptional regulators and co-factors, which we are actively pursuing. Moreover, we are exploring how human genetic variation affects bursting kinetics to be able to distinguish the contributions of specific DNA -binding proteins to either burst size or frequency mediated regulation. Altogether, transcriptome-wide single-cell measurements of gene expression enable quantitative investigation of the episodic transcription of our genes and opens up for mechanistic inquiries into how genomic sequence elements are read by trans-factors to control transcriptional burst sizes and frequencies. Moreover, I will introduce our recent Smart-seq3 method that provides unique abilities to count RNAs at both allele and isoform resolution.

Host: Michael Imbeault

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Wed 26 Feb 14:00: Bioinspired Nano- and Microstructured Surfaces: From Analysis and Replication to Applications

From Materials Chemistry Research Interest Group. Published on Jan 24, 2020.

Bioinspired Nano- and Microstructured Surfaces: From Analysis and Replication to Applications

Abstract not available

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Wed 26 Feb 14:00: Bioinspired Nano- and Microstructured Surfaces: From Analysis and Replication to Applications

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Bioinspired Nano- and Microstructured Surfaces: From Analysis and Replication to Applications

Abstract not available

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Mixed polyanionic compounds as positive electrodes in low‐cost electrochemical energy storage

By Yuanqi Lan, Wenjiao Yao, Xiaolong He, Tianyi Song, Yongbing Tang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Low cost electrochemical energy storage systems (EESSs) are urgently demanded to promote the application of renewable energy sources such as wind, solar, etc. Learning from the history of lithium‐ion batteries, the cost of EESSs depends mainly on charge‐carrier ions and redox centers in electrodes, and their performances are limited by positive electrodes. In this scenario, the minireview evaluates several EESSs candidates, and summarizes the known mixed polyanionic compounds (MPCs)—a family with robust frameworks and large channels for ion storage and migration. After comprehensive analysis, it is pointed out that a deeper exploration of MPCs may generate numbers of novel crystallographic‐interesting compounds and excellent cathode materials for low‐cost energy storage applications.

Thu 30 Jan 15:00: Candida recognition and manipulation of NK cells. Host: Dr Francesco Colucci (fc287@medschl.cam.ac.uk)

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Candida recognition and manipulation of NK cells.

Abstract not available

Host: Dr Francesco Colucci (fc287@medschl.cam.ac.uk)

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Thu 30 Jan 03:00: Candida recognition and manipulation of NK cells. Host: Dr Francesco Colucci (fc287@medschl.cam.ac.uk)

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Candida recognition and manipulation of NK cells.

Abstract not available

Host: Dr Francesco Colucci (fc287@medschl.cam.ac.uk)

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Fri 13 Mar 16:00: Dynamic Topography of Borborema Province and Surrounding Regions of Brazil

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Dynamic Topography of Borborema Province and Surrounding Regions of Brazil

Abstract not available

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Mon 04 May 15:00: Using CO2 to Your Advantage

From Materials Chemistry Research Interest Group. Published on Jan 24, 2020.

Using CO2 to Your Advantage

Abstract not available

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Mon 04 May 15:00: Using CO2 to Your Advantage

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Using CO2 to Your Advantage

Abstract not available

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Tue 28 Jan 16:00: Computational Neuroscience Journal Club

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Computational Neuroscience Journal Club

We will discuss: A distributional code for value in dopamine-based reinforcement learning, Will Dabney, Zeb Kurth-Nelson, Naoshige Uchida, Clara Kwon Starkweather, Demis Hassabis, Rémi Munos & Matthew Botvinick, Nature (2020), https://doi.org/10.1038/s41586-019-1924-6

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Tue 28 Jan 16:00: Computational Neuroscience Journal Club

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Computational Neuroscience Journal Club

We will discuss: A distributional code for value in dopamine-based reinforcement learning, Will Dabney, Zeb Kurth-Nelson, Naoshige Uchida, Clara Kwon Starkweather, Demis Hassabis, Rémi Munos & Matthew Botvinick, Nature (2020), https://doi.org/10.1038/s41586-019-1924-6

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Isothiourea‐Catalyzed Atropselective Acylation of Biaryl Phenols via Sequential Desymmetrization / Kinetic Resolution

By Elizabeth Munday, Markas Grove, Taisiiaa Feoktistova, Alexander Breukner, Daniel Walden, Claire Young, Alexandra Slawin, Andrew Campbell, Paul Ha-Yeon Cheong, Andrew David Smith from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Axially chiral phenols are attractive targets in organic synthesis. This motif is central to many natural products and widely used as precursors to, or directly, as chiral ligands and catalysts. Despite their utility few simple catalytic methods are available for their synthesis in high enantiopurity. Herein the atropselective acylation of a range of symmetric biaryl diols is investigated using isothiourea catalysis. Studies on a model biaryl diol substrate shows that the high product er observed in the process is a result of two successive enantioselective reactions consisting of an initial enantioselective desymmetrization coupled with a second chiroablative kinetic resolution. Extension of this process to a range of substrates, including a challenging tetraorthosubstituted biaryl diol, led to highly enantioenriched products (14 examples, up to 98:2 er), with either HyperBTM or BTM identified as the optimal catalyst depending upon the substitution pattern within the substrate. Computation has been used to understand the factors that lead to high enantiocontrol in this process, with maintenance of planarity to maximize a 1,5‐S•••O interaction within the key acyl ammonium intermediate identified as the major feature that determines atropselective acylation and thus product enantioselectivity.

The Effect of the Polyaromatic Hydrocarbon in the Formation of Fullerenes

By Bo Wu, Li Jiang, Yi Luo, Chunru Wang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

We go together: Evidence is presented that the formation pathway of C60 during arc‐discharge synthesis is fragment assembly, while the production of C2m (m=35, 38, 39) is enhanced by building‐block splicing. Several features of the building blocks are proposed to predict their influence on the formation of larger C2n fullerenes (n≥42). This provides insight into the formation of fullerenes, which is crucial to improve the yield of larger fullerenes. Abstract Tremendous advances in nanoscience have been made since the discovery of fullerenes. However, the short timescale of the growth process and high‐energy conditions of synthesis result in severe constraints to investigation of the mechanism of fullerene formation. In this work, we attempted to reveal the formation process by analyzing the variation in the yield of fullerenes under different conditions. Experiments and theoretical analysis show that the formation of fullerenes could be affected by the addition of polycyclic aromatic compounds. It is proposed that the formation of C60 during arc‐discharge synthesis is fragment assembling, while the yield of C2m (m=35, 38, 39) is strongly enhanced by building‐block splicing. In addition, several features of the building blocks are put forward to predict the extent of their influence to the formation of larger fullerenes C2n (n≥42). This work not only provides essential insight into the formation process of fullerenes, but more importantly also paves the way to improving the yield of larger fullerenes selectively.

Nanoporous Palladium Hydride for Electrocatalytic N2 Reduction under Ambient Conditions

By Wence Xu, Guilan Fan, Jialiang Chen, Jinhan Li, Le Zhang, Shengli Zhu, Xuncheng Su, Fangyi Cheng, Jun Chen from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Nanoporous palladium hydride synthesized by chemical dealloying and in situ hydrogen injection exhibits remarkable performance for electrocatalytic nitrogen fixation. A high NH3 yield (20.4 μg h−1 mg−1) and Faradaic efficiency (43.6 %) is obtained owing to fast kinetics of the activation and effective conversion of N2 into adsorbed intermediate *N2H. Abstract The electrocatalytic nitrogen reduction reaction (NRR) is an alternative eco‐friendly strategy for sustainable N2 fixation with renewable energy. However, NRR suffers from sluggish kinetics owing to difficult N2 adsorption and N≡N cleavage. Now, nanoporous palladium hydride is reported as electrocatalyst for electrochemical N2 reduction under ambient conditions, achieving a high ammonia yield rate of 20.4 μg h−1 mg−1 with a Faradaic efficiency of 43.6 % at low overpotential of 150 mV. Isotopic hydrogen labeling studies suggest the involvement of lattice hydrogen atoms in the hydride as active hydrogen source. In situ Raman analysis and density functional theory (DFT) calculations further reveal the reduction of energy barrier for the rate‐limiting *N2H formation step. The unique protonation mode of palladium hydride would provide a new insight on designing efficient and robust electrocatalysts for nitrogen fixation.

Mon 10 Feb 11:00: Present day anthropogenic climate forcings: The impact of including Earth System interactions

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Present day anthropogenic climate forcings: The impact of including Earth System interactions

Quantifying forcings from anthropogenic perturbations to the Earth System (ES) is important for understanding changes in climate since the pre-industrial period. In this presentation, we quantify and analyse a wide range of present-day (PD) anthropogenic climate forcings with the UK’s Earth System Model (ESM), UKESM1 , following the protocols defined by the Radiative Forcing Model Intercomparison Project (RFMIP) and the Aerosol and Chemistry Model Intercomparison Project (AerChemMIP). In particular, by quantifying effective radiative forcings (ERFs) that include rapid adjustments within a full ESM , it enables the role of various climate-chemistry-aerosol-cloud feedbacks to be quantified.

By including feedbacks between greenhouse gases, stratospheric and tropospheric ozone, aerosols, and clouds, some of which act non-linearly, this work demonstrates the importance of ES interactions when quantifying climate forcing. It also suggests that rapid adjustments need to include chemical as well as physical adjustments to fully account for complex ES interactions.

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Single‐Atom Iron Boosts Electrochemiluminescence

By Wenling Gu, Hengjia Wang, Lei Jiao, Yu Wu, Yuxin Chen, Liuyong Hu, Jingming Gong, Dan Du, Chengzhou Zhu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 24, 2020.

Boosting luminescence: The traditional luminol–H2O2 electrochemiluminescence (ECL) sensing platform suffers from self‐decomposition of H2O2 at room temperature, hampering its application for quantitative analysis. Single‐atom iron boosts luminol ECL by in situ generating reactive oxygen species, achieving sensitive detection of antioxidants. Abstract The traditional luminol–H2O2 electrochemiluminescence (ECL) sensing platform suffers from self‐decomposition of H2O2 at room temperature, hampering its application for quantitative analysis. In this work, for the first time we employ iron single‐atom catalysts (Fe‐N‐C SACs) as an advanced co‐reactant accelerator to directly reduce the dissolved oxygen (O2) to reactive oxygen species (ROS). Owing to the unique electronic structure and catalytic activity of Fe‐N‐C SACs, large amounts of ROS are efficiently produced, which then react with the luminol anion radical and significantly amplify the luminol ECL emission. Under the optimum conditions, a Fe‐N‐C SACs–luminol ECL sensor for antioxidant capacity measurement was developed with a good linear range from 0.8 μm to 1.0 mm of Trolox.

Thu 27 Feb 11:30: TBC

From All Talks (aka the CURE list). Published on Jan 24, 2020.

TBC

Abstract not available

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Thu 27 Feb 16:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Title to be confirmed

Abstract not available

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Thu 20 Feb 16:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 24, 2020.

Title to be confirmed

Abstract not available

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[ASAP] Quantification of Material Gradients in Core/Shell Nanocrystals Using EXAFS Spectroscopy

By Klaus Boldt*†, Stuart Bartlett‡, Nicholas Kirkwood¶, and Bernt Johannessen§ from Nano Letters: Latest Articles (ACS Publications). Published on Jan 24, 2020.

TOC Graphic

Nano Letters
DOI: 10.1021/acs.nanolett.9b04143

[ASAP] Basal Nanosuit of Graphite for High-Energy Hybrid Li Batteries

By Yuanming Liu†‡, Xianying Qin†, Fang Liu†‡, Binhua Huang†‡, Shaoqiong Zhang†‡, Feiyu Kang†‡, and Baohua Li*† from ACS Nano: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b07706

[ASAP] Peptide-Driven Shape Control of Low-Dimensional DNA Nanostructures

By Chan-Jin Kim, Ji-eun Park, Xiaole Hu, Shine K. Albert, and So-Jung Park* from ACS Nano: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b09312

[ASAP] Graphene Oxide-Grafted Magnetic Nanorings Mediated Magnetothermodynamic Therapy Favoring Reactive Oxygen Species-Related Immune Response for Enhanced Antitumor Efficacy

By Xiaoli Liu†‡??, Bin Yan†?, Yao Li‡?, Xiaowei Ma‡?, Wangbo Jiao§, Kejian Shi#, Tingbin Zhang§, Shizhu Chen?¶, Yuan He§, Xing-Jie Liang‡?, and Haiming Fan*†§ from ACS Nano: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b08320

[ASAP] Amyloid–Polyphenol Hybrid Nanofilaments Mitigate Colitis and Regulate Gut Microbial Dysbiosis

By Bing Hu*†, Shijie Yu†, Ce Shi‡, Jie Gu§, Yun Shao?, Quan Chen?, Yunqi Li‡, and Raffaele Mezzenga¶ from ACS Nano: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b09125

[ASAP] Rapid Intestinal Uptake and Targeted Delivery to the Liver Endothelium Using Orally Administered Silver Sulfide Quantum Dots

By Nicholas J. Hunt†‡§?, Glen P. Lockwood†‡?, Frank H. Le Couteur†, Peter A. G. McCourt??, Nidhi Singla?, Sun Woo Sophie Kang†‡§, Andrew Burgess†§, Zdenka Kuncic?#?, David G. Le Couteur†‡§?, and Victoria C. Cogger*†‡§? from ACS Nano: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b06071

[ASAP] 1,2-Amino Alcohols via Cr/Photoredox Dual-Catalyzed Addition of a-Amino Carbanion Equivalents to Carbonyls

By J. Luca Schwarz‡, Roman Kleinmans‡, Tiffany O. Paulisch, and Frank Glorius* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12053

[ASAP] High Interfacial-Energy Interphase Promoting Safe Lithium Metal Batteries

By Sufu Liu†‡, Xiao Ji†, Jie Yue†, Singyuk Hou†, Pengfei Wang†, Chunyu Cui†, Ji Chen†, Bowen Shao§, Jingru Li‡, Fudong Han*§, Jiangping Tu*‡, and Chunsheng Wang*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11750

[ASAP] The Doping Mechanism of Halide Perovskite Unveiled by Alkaline Earth Metals

By Nga Phung†¶, Roberto Fe´lix†¶, Daniele Meggiolaro‡§, Amran Al-Ashouri†, Gabrielle Sousa e Silva†, Claudia Hartmann†, Juanita Hidalgo?, Hans Ko¨bler†, Edoardo Mosconi‡§, Barry Lai?, Rene Gunder†, Meng Li†#?, Kai-Li Wang#, Zhao-Kui Wang#, Kaiqi Nie†#, Evelyn Handick†, Regan G. Wilks†, Jose A. Marquez†, Bernd Rech†?, Thomas Unold†, Juan-Pablo Correa-Baena?, Steve Albrecht†?, Filippo De Angelis‡§?, Marcus Ba¨r†??, and Antonio Abate*†¦ from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11637

[ASAP] uMBD: A Materials-Ready Dispersion Correction That Uniformly Treats Metallic, Ionic, and van der Waals Bonding

By Minho Kim†‡?, Won June Kim§?, Timothy Gould?, Eok Kyun Lee*†, Se´bastien Lebe`gue*‡, and Hyungjun Kim*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11589

[ASAP] Stereoelectronic Effects Impact Glycan Recognition

By Caitlin M. McMahon†?§, Christine R. Isabella†§, Ian W. Windsor†, Paul Kosma?, Ronald T. Raines†, and Laura L. Kiessling*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11699

[ASAP] Sequence–Structure–Binding Relationships Reveal Adhesion Behavior of the Car9 Solid-Binding Peptide: An Integrated Experimental and Simulation Study

By Brittney Hellner†, Sarah Alamdari†, Harley Pyles‡§, Shuai Zhang#?, Arushi Prakash†, Kayla G. Sprenger†, James J. De Yoreo#?, David Baker‡§?, Jim Pfaendtner*†, and Franc¸ois Baneyx*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11617

[ASAP] Catalyzing the Hydrodefluorination of CF3-Substituted Alkenes by PhSiH3. H Transfer from a Nickel Hydride

By Chengbo Yao, Shuai Wang†, Jack Norton*, and Matthew Hammond from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b13757

[ASAP] A Single Point Mutation Converts GH84 O-GlcNAc Hydrolases into Phosphorylases: Experimental and Theoretical Evidence

By David Teze*†‡#, Joan Coines§#, Llui´s Raich§?, Valentina Kalichuk‡, Claude Solleux‡, Charles Tellier‡, Corinne Andre´-Miral‡, Birte Svensson*†, and Carme Rovira*§? from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b09655

[ASAP] Total Synthesis and Biological Evaluation of Tiancimycins A and B, Yangpumicin A, and Related Anthraquinone-Fused Enediyne Antitumor Antibiotics

By K. C. Nicolaou*†, Dipendu Das†?, Yong Lu†?, Subhrajit Rout†?, Emmanuel N. Pitsinos†§, Joseph Lyssikatos#, Alexander Schammel#, Joseph Sandoval#, Mikhail Hammond#, Monette Aujay#, and Julia Gavrilyuk# from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12522

[ASAP] Tunable Adhesion from Stoichiometry-Controlled and Sequence-Defined Supramolecular Polymers Emerges Hierarchically from Cyanostar-Stabilized Anion–Anion Linkages

By Wei Zhao†, Joshua Tropp‡, Bo Qiao†§, Maren Pink†, Jason D. Azoulay‡, and Amar H. Flood*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12645

[ASAP] Effects of Covalency on Anionic Redox Chemistry in Semiquinoid-Based Metal–Organic Frameworks

By Michael E. Ziebel†‡, Carlo Alberto Gaggioli§, Ari B. Turkiewicz†, Won Ryu?, Laura Gagliardi§, and Jeffrey R. Long*†‡? from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b13050

[ASAP] Modularly Designed Peptide Nanoprodrug Augments Antitumor Immunity of PD-L1 Checkpoint Blockade by Targeting Indoleamine 2,3-Dioxygenase

By Xuexiang Han†‡#, Keman Cheng†§#, Ying Xu†#, Yazhou Wang†, Huan Min†, Yinlong Zhang†‡, Xiao Zhao†‡, Ruifang Zhao†‡, Gregory J. Anderson?, Lei Ren§, Guangjun Nie*†‡, and Yiye Li*†‡ from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12232

[ASAP] Direct and Scalable Electroreduction of Triphenylphosphine Oxide to Triphenylphosphine

By Shuhei Manabe, Curt M. Wong, and Christo S. Sevov* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12112

[ASAP] Ketone Synthesis from Benzyldiboronates and Esters: Leveraging a-Boryl Carbanions for Carbon–Carbon Bond Formation

By Boran Lee and Paul J. Chirik* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11944

[ASAP] Metathetical Exchange between Metal–Metal Triple Bonds

By Joshua D. Queen, Alice C. Phung, Christine A. Caputo†, James C. Fettinger, and Philip P. Power* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 24, 2020.

Journal of the American Chemical Society
DOI: 10.1021/jacs.9b13604

Author Correction: Artificial water channels enable fast and selective water permeation through water-wire networks

By Manish Kumar from Nature Nanotechnology - Issue - nature.com science feeds. Published on Jan 24, 2020.

Nature Nanotechnology, Published online: 24 January 2020; doi:10.1038/s41565-020-0640-6

Author Correction: Artificial water channels enable fast and selective water permeation through water-wire networks

Rational Design, Synthesis, Adsorption Principles and Applications of Metal Oxide Adsorbents: A Review

By Ji-Jun Zou from RSC - Nanoscale latest articles. Published on Jan 24, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR09274A, Review Article
Li Wang, Chengxiang Shi, Li Wang, Lun Pan, Xiangwen Zhang, Ji-Jun Zou
The shortage of water resource and increasingly serious water pollution drive the development of high-efficiency water treatment technology. Among a variety of technologies, adsorption is widely used in environmental remediation....
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Molecular Complementarity and Structural Heterogeneity within Co-assembled Peptide β-Sheet Nanofibers

By Anant K. Paravastu from RSC - Nanoscale latest articles. Published on Jan 24, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR08725G, Paper
Kong Ming Wong, Yiming Wang, Dilon T Seroski, Grant E Larkin, Gregory A Hudalla, Anil K Mehta, Carol Hall, Anant K. Paravastu
Self-assembling peptides have garnered an increasing amount of interest as a functional biomaterial for medical and biotechnological applications. Recently, β-sheet peptide designs utilizing complementary pairs of peptides composed of charged...
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CO2-Triggered Reversible Phase Transfer of Graphene Quantum Dots for Visible Light-Promoted Amines Oxidation

By Run Li from RSC - Nanoscale latest articles. Published on Jan 24, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR10195K, Paper
Xian Jun Tu, Qin Wang, Feng Zhang, Fang Lan, Hongbo Liu, Run Li
Emerging as novel photoluminescent nanomaterials, carbon dots have attracted increasing attentions in photocatalytic application such as hydrogen evolution, carbon dioxide reduction, pollutants degradation and organic synthesis. However, it is always...
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Effect of hydrodynamic inter-particle interaction on orbital motion of dielectric nanoparticles driven by an optical vortex

By Satoyuki Kawano from RSC - Nanoscale latest articles. Published on Jan 24, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR10591C, Paper
Tetsuro Tsuji, Ryoji Nakatsuka, Kichitaro Nakajima, Kentaro Doi, Satoyuki Kawano
We experimentally and theoretically characterize dielectric nano- and microparticle orbital motion induced by an optical vortex of the Laguerre–Gaussian beam. The key to stable orbiting of dielectric nanoparticles is hydrodynamic...
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Improve charge injection of the edge aligned MoS2/MoO2 hybrid nanosheets for highly robust and efficient electrocatalysis of H2 production

By Liangxu Lin from RSC - Nanoscale latest articles. Published on Jan 24, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR10578F, Paper
Shuaishuai Li, Li Zhao, Shulai Lei, Aiping Liu, Jun Chen, Chaorong Li, Huaping Wu, Liangxu Lin
Molybdenum disulfide (MoS2) can be an efficient electro-catalyst for hydrogen evolution reaction (HER) alternative to precious metals, but significant efforts are still needed to further improve the efficiency. Among various...
The content of this RSS Feed (c) The Royal Society of Chemistry

Structural identification of percolation of nanoparticles

By Julian Oberdisse from RSC - Nanoscale latest articles. Published on Jan 24, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR09395H, Paper
Dafne Musino, Anne-Caroline Genix, Edouard Chauveau, Thomas Bizien, Julian Oberdisse
We propose a method relying on structural measurements by small-angle scattering to quantitatively follow aggregation of nanoparticles (NPs) in concentrated colloidal assemblies or suspensions up to percolation, regardless of complex...
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Optomechanical resonating probe for very high frequency sensing of atomic forces

By Ivan Favero from RSC - Nanoscale latest articles. Published on Jan 24, 2020.

Nanoscale, 2020, Advance Article
DOI: 10.1039/C9NR09690F, Communication
Pierre Etienne Allain, Lucien Schwab, Colin Mismer, Marc Gely, Estelle Mairiaux, Maxime Hermouet, Benjamin Walter, Giuseppe Leo, Sébastien Hentz, Marc Faucher, Guillaume Jourdan, Bernard Legrand, Ivan Favero
An optomechanical probe is introduced that operates at very high frequency, opening up a pathway to the measurement of atomic forces at shorter timescale.
To cite this article before page numbers are assigned, use the DOI form of citation above.
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Transition-metal phthalocyanine monolayers as new Chern insulators

By Lei Gu from RSC - Nanoscale latest articles. Published on Jan 24, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR09817H, Paper
Ruqian Wu, Jie Li, Lei Gu
To explore new materials for the realization of the quantum anomalous Hall effect (QAHE), we studied electronic, magnetic and topological properties of transition-metal phthalocyanine (TMPc) monolayers in a square lattice....
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Parahydrogen‐induced Hyperpolarization of Gases

By Kirill V. Kovtunov, Igor V. Koptyug, Marianna Fekete, Simon B. Duckett, Thomas Theis, Baptiste Joalland, Eduard Y Chekmenev from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Imaging of gases is a major challenge for any modality including MRI. NMR and MRI signals are directly proportional to the nuclear spin density and the degree of alignment of nuclear spins with applied static magnetic field, which is called nuclear spin polarization. The level of nuclear spin polarization is typically very low, i.e ., one hundred thousandth of the potential maximum at 1.5 T and a physiologically relevant temperature. As a result, MRI typically focusses on imaging highly concentrated tissue water. Hyperpolarization methods transiently increases nuclear spin polarizations up to unity, yielding corresponding gains in MRI signal level of several orders of magnitude that enable the 3D imaging of dilute biomolecules including gases. Parahydrogen‐induced polarization is a fast, highly scalable, and low‐cost hyperpolarization technique. The focus of this Minireview is to highlight selected advances in the field of parahydrogen‐induced polarization for the production of hyperpolarized compounds, which can be potentially employed as inhalable contrast agents.

Electron configuration modulation of Ni single‐atoms for remarkably elevated photocatalytic hydrogen evolution

By Xixiong Jin, Rongyan Wang, Lingxia Zhang, Rui Si, Meng Shen, Min Wang, Jianjian Tian, Jianlin Shi from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

The emerging metal single‐atom catalyst has aroused extensive attentions in multiple fields such as clean energy, environmental protection, biomedicine, etc. Unfortunately, though it has been proved to be highly active, the origins of the activity of the single‐atom sites remain unrevealed to date due to the lack of deep insight on electronic level. Herein, we have constructed partially‐oxidized Ni single‐atom sites in polymeric carbon nitride (CN), which elevates the photocatalytic performance of by over 30 times. It has been revealed that the 3d orbital of the partially oxidized Ni single‐atom sites is filled with unpaired d‐electrons which are ready to be excited under irradiation. Such an electron configuration results in elevated light response, conductivity, charge separation and mobility of the photocatalyst concurrently, thus largely augmenting the photocatalytic performance.

Exploiting a C–N bond Forming Cytochrome P450 Monooxygenase for C–S Bond Formation

By Iori Morita, Takahiro Mori, Takaaki Mitsuhashi, Shotaro Hoshino, Yoshimasa Taniguchi, Takashi Kikuchi, Kei Nagae, Norihiro Nasu, Makoto Fujita, Tomohiko Ohwada, Ikuro Abe from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Cytochrome P450 monooxygenases catalyze a wide range of oxidative transformations. TleB, a P450 monooxygenase involved in the biosynthesis of teleocidin, catalyzes C–S bond formation through both oxidation‐mediated and radical‐mediated mechanisms to generate a sulfur‐containing indolactam and an unusual 6/5/8 tricyclic compound. These results may enable the production of new unnatural compounds using enzymes as biocatalysts. Abstract C–S bond formation reactions are widely distributed in the biosynthesis of biologically active molecules, and thus have received much attention over the past decades. Herein, we report intramolecular C–S bond formation by a P450 monooxygenase, TleB, which normally catalyzes a C−N bond formation in teleocidin biosynthesis. Based on the proposed reaction mechanism of TleB, a thiol‐substituted substrate analogue was synthesized and tested in the enzyme reaction, which afforded the unprecedented sulfur‐containing thio‐indolactam V, in addition to an unusual indole‐fused 6/5/8‐tricyclic product whose structure was determined by the crystalline sponge method. Interestingly, conformational analysis revealed that the SOFA conformation is stable in thio‐indolactam V, in sharp contrast to the major TWIST form in indolactam V, resulting in differences in their biological activities.

Enhanced Surface Interactions Enable Fast Li+ Conduction in Oxide/Polymer Composite Electrolyte

By Nan Wu, Po‐Hsiu Chien, Yumin Qian, Yutao Li, Henghui Xu, Nicholas S. Grundish, Biyi Xu, Haibo Jin, Yan‐Yan Hu, Guihua Yu, John B. Goodenough from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

The strong interaction between the surface oxygen vacancies of GDC/LSGM and the TFSI− anions in the composite polymer electrolyte changes Li+ distribution in two local environments, and the population increase of mobile Li+ ions in A2 significantly enhances the Li+ conductivity of the composite electrolyte. Abstract Li+‐conducting oxides are considered better ceramic fillers than Li+‐insulating oxides for improving Li+ conductivity in composite polymer electrolytes owing to their ability to conduct Li+ through the ceramic oxide as well as across the oxide/polymer interface. Here we use two Li+‐insulating oxides (fluorite Gd0.1Ce0.9O1.95 and perovskite La0.8Sr0.2Ga0.8Mg0.2O2.55) with a high concentration of oxygen vacancies to demonstrate two oxide/poly(ethylene oxide) (PEO)‐based polymer composite electrolytes, each with a Li+ conductivity above 10−4 S cm−1 at 30 °C. Li solid‐state NMR results show an increase in Li+ ions (>10 %) occupying the more mobile A2 environment in the composite electrolytes. This increase in A2‐site occupancy originates from the strong interaction between the O2− of Li‐salt anion and the surface oxygen vacancies of each oxide and contributes to the more facile Li+ transport. All‐solid‐state Li‐metal cells with these composite electrolytes demonstrate a small interfacial resistance with good cycling performance at 35 °C.

Gold(I)‐Catalyzed Cycloisomerization of 3‐Alkoxyl‐1,6‐diynes: A Facile Access to Bicyclo[2.2.1]hept‐5‐en‐2‐one

By A. Stephen K. Hashmi, Chao Hu, Tao Wang, Matthias Rudolph, Thomas Oeser, Abdullah M. Asiri from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

A novel gold‐catalyzed cycloisomerization of 1,6‐diynes was achieved, providing an atom‐economic approach to a diverse set of bicyclo[2.2.1]hept‐5‐en‐2‐one in moderate to good yields. With unsymmetrical starting materials with two different internal alkynyl substituents, to some extent, the regioselectivity could be controlled by both electronic and steric factors. This unprecedented reactivity pattern may inspire new and unconventional strategies for the preparation of bridged ring Systems.

Multi‐Step Crystallization of Self‐Organized Spiral Eutectics

By Saman Moniri, Hrishikesh Bale, Tobias Volkenandt, Yeqing Wang, Jianrong Gao, Tianxiang Lu, Kai Sun, Robert O. Ritchie, Ashwin J. Shahani from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

Eutectic crystallization involves the growth of solid phases from a liquid. This work investigates the origins of certain eutectics that grow into spiral geometry. The results demonstrate that the spiral formation follows a two‐step process, wherein the first step is mediated by the low solid–liquid interfacial energy of a precursor phase, and the second step by crystallographic defects on the precursor. Abstract A method for the solidification of metallic alloys involving spiral self‐organization is presented as a new strategy for producing large‐area chiral patterns with emergent structural and optical properties, with attention to the underlying mechanism and dynamics. This study reports the discovery of a new growth mode for metastable, two‐phase spiral patterns from a liquid metal. Crystallization proceeds via a non‐classical, two‐step pathway consisting of the initial formation of a polytetrahedral seed crystal, followed by ordering of two solid phases that nucleate heterogeneously on the seed and grow in a strongly coupled fashion. Crystallographic defects within the seed provide a template for spiral self‐organization. These observations demonstrate the ubiquity of defect‐mediated growth in multi‐phase materials and establish a pathway toward bottom‐up synthesis of chiral materials with an inter‐phase spacing comparable to the wavelength of infrared light. Given that liquids often possess polytetrahedral short‐range order, our results are applicable to many systems undergoing multi‐step crystallization.

Nanoparticle Drug Delivery Can Reduce the Hepatotoxicity of Therapeutic Cargo

By Feifei Yang, Yusra Medik, Liantao Li, Xi Tian, Dong Fu, Kim L. R. Brouwer, Kyle Wagner, Bo Sun, Hossein Sendi, Yu Mi, Andrew Z. Wang from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

Hepatotoxicity is a key concern in the clinical translation of nanomedicine due to nanotherapeutics' high accumulation in the liver. It is shown that nanotherapeutics have lower hepatotoxicity than their small‐molecule counterparts. It is further shown that the uptake of nanotherapeutics by macrophages in the liver is the key factor in the reduced hepatotoxicity. Abstract Hepatotoxicity is a key concern in the clinical translation of nanotherapeutics because preclinical studies have consistently shown that nanotherapeutics accumulates extensively in the liver. However, clinical‐stage nanotherapeutics have not shown increased hepatotoxicity. Factors that can contribute to the hepatotoxicity of nanotherapeutics beyond the intrinsic hepatotoxicity of nanoparticles (NPs) are poorly understood. Because of this knowledge gap, clinical translation efforts have avoided hepatotoxic molecules. By examining the hepatotoxicity of nanoformulations of known hepatotoxic compounds, it is demonstrated that nanotherapeutics are associated with lower hepatotoxicity than their small‐molecule counterparts. It is also found that the reduced hepatotoxicity is related to the uptake of nanotherapeutics by macrophages in the liver. These findings can facilitate further development and clinical translation of nanotherapeutics.

Demonstration of a Broadband Photodetector Based on a Two‐Dimensional Metal–Organic Framework

By Himani Arora, Renhao Dong, Tommaso Venanzi, Jens Zscharschuch, Harald Schneider, Manfred Helm, Xinliang Feng, Enrique Cánovas, Artur Erbe from Wiley: Advanced Materials: Table of Contents. Published on Jan 23, 2020.

2D metal–organic framework (MOF) films of Fe3(THT)2(NH4)3 are employed as an active element in a two‐terminal photodetector device, operating in the UV‐to‐NIR region. Owing to small bandgap of the MOF samples (≈0.45 eV), the photodetectors are best operated at 77 K. This is attributed to the suppression of thermally activated charge carriers at low temperatures, leading to improved performance of the device. Abstract Metal–organic frameworks (MOFs) are emerging as an appealing class of highly tailorable electrically conducting materials with potential applications in optoelectronics. Yet, the realization of their proof‐of‐concept devices remains a daunting challenge, attributed to their poor electrical properties. Following recent work on a semiconducting Fe3(THT)2(NH4)3 (THT: 2,3,6,7,10,11‐triphenylenehexathiol) 2D MOF with record‐high mobility and band‐like charge transport, here, an Fe3(THT)2(NH4)3 MOF‐based photodetector operating in photoconductive mode capable of detecting a broad wavelength range from UV to NIR (400–1575 nm) is demonstrated. The narrow IR bandgap of the active layer (≈0.45 eV) constrains the performance of the photodetector at room temperature by band‐to‐band thermal excitation of charge carriers. At 77 K, the device performance is significantly improved; two orders of magnitude higher voltage responsivity, lower noise equivalent power, and higher specific detectivity of 7 × 108 cm Hz1/2 W−1 are achieved under 785 nm excitation. These figures of merit are retained over the analyzed spectral region (400–1575 nm) and are commensurate to those obtained with the first demonstrations of graphene‐ and black‐phosphorus‐based photodetectors. This work demonstrates the feasibility of integrating conjugated MOFs as an active element into broadband photodetectors, thus bridging the gap between materials' synthesis and technological applications.

Rapid, label‐free optical spectroscopy platform for diagnosis of heparin‐induced thrombocytopenia

By Zufang Huang, Soumik Siddhanta, Gang Zheng, Thomas Kickler, Ishan Barman from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

In this study, we propose the use of surface‐enhanced Raman spectroscopy (SERS) to determine spectral markers that can aid in the recognition of heparin‐induced thrombocytopenia (HIT), a difficult‐to‐diagnose immune‐related complication that often leads to limb ischemia and thromboembolism . The ability to produce distinct molecular signatures without requiring addition of exogenous labels enables unbiased inquiry and makes SERS an attractive complementary diagnostic tool for various complex pathologies. Specifically, we have designed a new plasmonic capillary flow platform that offers ultrasensitive , label‐free measurement capability as well as efficient handling of blood serum samples. The optimized capillary channel shows excellent reproducibility and long‐term stability and, crucially, provides an alternative diagnostic rubric for determination of HIT by leveraging machine‐learning based classification of the spectroscopic data. With further refinement, we envision that a portable Raman instrument could be combined with the capillary‐based SERS analytical tool for rapid, non‐destructive determination of HIT in the clinical laboratory, without perturbing the existing diagnostic workflow.

Engineering Iron‐Nickel Nanoparticles for Magnetically‐Induced CO2 Methanation in Continuous Flow

By Déborah De Masi, Juan M. Asensio, Pier-Francesco Fazzini, Lise-Marie Lacroix, Bruno Chaudret from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Induction heating of magnetic nanoparticles (NPs) has been recently explored as a new methodology to activate heterogeneous catalytic reactions. This approach requires the design and the synthesis of nano‐objects displaying both a high heating power and an excellent catalytic activity. Here, using a surface engineering approach, we report for the first time the use of bimetallic NPs for magnetically‐induced CO2 methanation which acts both as heating agent and as catalyst. Thus, we describe the organometallic synthesis of Fe30Ni70 NPs, displaying high heating powers at low magnetic field amplitudes. These NPs are active but only slightly selective for CH4 after deposition on SirAlOx due to the presence of an iron rich shell (25 mL·min‐1, 25 mT, 300 kHz, conversion 71%, methane selectivity 65%). Remarkably, a proper surface engineering consisting in depositing a thin Ni layer leads to Fe30Ni70@Ni NPs displaying a very high activity for CO2 hydrogenation and a full selectivity. For the first time, a quantitative yield in methane is obtained at low magnetic field and mild conditions (25 mL·min‐1, 19 mT, 300 kHz, conversion 100%, methane selectivity 100%).

Complete Switch of Directional Selectivity in the Formal Hydroalkylation of 1,3‐Dienes and Enynes with Simple Hydrazones

By Leiyang Lv, Lin Yu, Zihang Qiu, Chao-Jun Li from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Controlling reaction selectivity is a permanent pursuit for chemists. In particular, regio‐selective catalysis, which exploits and/or overcomes innate steric and electronic bias to deliver diverse regio‐enriched products from the same starting materials, represents a powerful tool for divergent synthesis. Recently, our group reported the 1,2‐Markovnikov hydroalkylation of 1,3‐dienes with simple hydrazones to generate branched allylic compounds when a nickel catalyst was used. As part of the effort, herein we show that a complete switch of Markovnikov to anti‐Markovnikov directionality is obtained by slightly changing to a ruthenium catalyst, thus providing a direct and efficient access to the homoallylic products exclusively. Isotopic substitution experiments indicate that no reversible hydro‐metallation across the metal‐π‐allyl system occurred under ruthenium catalysis. Moreover, this protocol is also applicable to the regio‐specific hydro‐alkylation of the distal C=C bond of 1,3‐enynes.

Fri 21 Feb 16:00: Kilometer-scale structure inside the Hawaiian ULVZ

From All Talks (aka the CURE list). Published on Jan 23, 2020.

Kilometer-scale structure inside the Hawaiian ULVZ

Abstract not available

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Thu 20 Feb 14:00: Exploiting Sparsity in Semidefinite and Sum of Squares Programming

From All Talks (aka the CURE list). Published on Jan 23, 2020.

Exploiting Sparsity in Semidefinite and Sum of Squares Programming

Semidefinite and sum of squares optimization have found a wide range of applications, including control theory, fluid dynamics, machine learning, and power systems. In theory they can be solved in polynomial time using interior-point methods. However, these methods are only practical for small- to medium- sized problem instances.

For large instances, it is essential to exploit or even impose sparsity and structure within the problem in order to solve the associated programs efficiently. In this talk I will present recent results on the analysis and design of networked systems, where chordal sparsity can be used to decompose the resulting SDPs, and solve an equivalent set of smaller semidefinite constraints. I will also discuss how sparsity and operator-splitting methods can be used to speed up computation of large SDPs and introduce our open-source solver CDCS . Lastly, I will extend the decomposition result on SDPs to SOS optimization with polynomial constraints, revealing a practical way to connect SOS optimization and DSOS /SDSOS optimization for sparse problem instances.

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Fri 28 Feb 16:00: Conditioning waveform tomography with Sobolev gradients

From All Talks (aka the CURE list). Published on Jan 23, 2020.

Conditioning waveform tomography with Sobolev gradients

Abstract not available

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Fri 14 Feb 16:00: The effect of equilibrium stress on the elastic tensor

From All Talks (aka the CURE list). Published on Jan 23, 2020.

The effect of equilibrium stress on the elastic tensor

Abstract not available

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Fri 07 Feb 16:00: Crustal Flow and Formation in Iceland from Seismic Anisotropy

From All Talks (aka the CURE list). Published on Jan 23, 2020.

Crustal Flow and Formation in Iceland from Seismic Anisotropy

Abstract not available

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Wed 29 Jan 16:00: Ancient DNA, extinction, domestication and the cost of modern farming

From All Talks (aka the CURE list). Published on Jan 23, 2020.

Ancient DNA, extinction, domestication and the cost of modern farming

Beginning with dogs over 15,000 years ago, the domestication of plants and animals has played a key role in the development of modern societies. Given its fundamental importance, a vast body of literature from a wide variety of academic disciplines has explored the origins of domestication. Ancient DNA in particular, obtained both modern and archaeological samples, have had a tremendous impact on our understanding of animal domestication, not only allowing us to retrace their geographic and temporal origin but also to understand fundamental evolutionary processes. Here I will present recent work from my group, on pigs, dogs and chickens that highlights how ancient DNA is revolutionising our understanding of their history.

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Radially inwardly aligned hierarchical porous carbon for ultra‐long‐life lithium‐sulfur batteries

By Zhisheng Yu, Menglan Liu, Daying Guo, Jiahui Wang, Xing Chen, Jun Li, Huile Jin, Zhi Yang, Xi'an Chen, Shun Wang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Rational design of hollow micro‐ and/or nano‐structured cathodes as sulfur hosts has shown the appealing potential for high‐performance lithium‐sulfur batteries. However, the hard control of infusing sulfur into a desirable hollow hosts and poor interactions between high loading sulfur and electrolyte as two serious issues hinder their further commercial applications. Herein, we designed a kind of hierarchical porous hollow carbon nanospheres with radially inwardly aligned supporting ribs to mitigate these problems. Such radially well‐aligned porous structure could fasten the efficient sulfur infusion and maximize sulfur utilization owing to the well‐ordered pore channels. This highly organized internal carbon skeleton can also enhance the electronic conductivity. The prepared hollow carbon nanospheres with further nitrogen‐doping as the sulfur host material exhibit good capacity and excellent cycling performance (0.044% capacity degradation per each cycle for 1000 cycles). This novel radially inwardly aligned hierarchical porous structure provides a new strategy for hollow material development applying in energy storage systems.

Specific Binding of a D‐RNA G‐Quadruplex Structure with an L‐RNA Aptamer

By Chun-Yin Chan, Chun Kit Kwok from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

G‐quadruplex (G4) structures are of general importance in chemistry and biology, such as biosensing, gene regulation, and cancers. Although a large repertoire of G4‐binding tools has been developed, there is so far no aptamer being developed to interact with G4. Moreover, the G4 selectivity of current toolkits is very limited. Herein, we report the first L‐RNA aptamer that targets D‐RNA G‐quadruplex (rG4). Using TERRA rG4 as an example, our results reveal that this new L‐RNA aptamer, Ap3‐7, folds into a unique secondary structure, exhibits high G4 selectivity and interferes with TERRA rG4‐RHAU53 binding effectively. Our novel approach and findings open up a new door in further developing G4‐specific tools for diverse applications.

Phosphine‐Based Covalent Organic Framework for the Controlled Synthesis of Broad‐Scope Ultrafine Nanoparticles

By Rao Tao, Xiran Shen, Yiming Hu, Kun Kang, Yaqian Zheng, Shichang Luo, Shiyu Yang, Wenliang Li, Shuanglong Lu, Yinghua Jin, Li Qiu, Wei Zhang from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

A phosphine‐based covalent organic framework (COF) is constructed and used as a scaffold for size‐controlled synthesis of stable and highly dispersed unltrafine mono‐ and bimetallic nanoparticles. The obtained Phos‐COF‐supported Pd, Pt, Au, and Pd/Au nanoparticles exhibit excellent catalytic activities toward the cross‐coupling, reduction, and tandem one‐pot cross‐coupling and reduction reactions. Abstract In this work, a phosphine‐based covalent organic framework (Phos‐COF‐1) is successfully synthesized and employed as a template for the confined growth of broad‐scope nanoparticles (NPs). Ascribed to the ordered distribution of phosphine coordination sites in the well‐defined pores, various stable and well‐dispersed ultrafine metal NPs including Pd, Pt, Au, and bimetallic PdAuNPs with narrow size distributions are successfully prepared as determined by transmission electron microscopy, X‐ray photoelectron spectroscopy, inductively coupled plasma, and powder X‐ray diffraction analyses. It is also demonstrated that the as‐prepared Phos‐COF‐1‐supported ultrafine NPs exhibit excellent catalytic activities and recyclability toward the Suzuki–Miyaura coupling reaction, reduction of nitro‐phenol and 1‐bromo‐4‐nitrobenzene, and even tandem coupling and reduction of p‐nitroiodobenzene. This work will open many new possibilities for preparing COF‐supported ultrafine NPs with good dispersity and stability for a broad range of applications.

Photocontrolled Hierarchical Self‐Assembly of Anisotropic Micropatterns of Nanofibers onto Isotropic Surfaces

By Christiaan Vet, Leire Gartzia‐Rivero, Philip Schäfer, Guillaume Raffy, André Del Guerzo from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

Hierarchical self‐assembly into nanofibers is achieved using a visible light triggered photoconversion of a diketone pro‐gelator into an anthracenic gelator. Separate photocontrol of nucleation and growth leads to patterning of nanofibers onto isotropic surfaces. Collective growth can result in 79% oriented anisotropic micropatterns emitting linearly polarized light. These can be juxtaposed with chosen orientations. Abstract Hierarchical self‐assembly is achieved using a visible light triggered photoreaction. A pro‐gelator, α‐diketone‐2,3‐didecyloxyanthracene, is photoconverted into a low molecular weight gelator, 2,3‐didecyloxyanthracene (DDOA), that self‐assembles into nanofibers. Spatial confinement and patterns of these nanofibers onto a surface are achieved by localizing initial nucleation with a focused laser and photogenerate subsequent fiber growth with the laser or gentler wide‐field irradiation. Remarkably, collective growth of nanofibers results in anisotropic micropatterns with orientation factors (OF) reaching 79%, resulting in collective emission of linearly polarized light. The OF, distance of collective growth and fiber density, are controlled by the photoirradiation conditions and the balance of interactions between DDOA aggregates and the glass surface. An unprecedented juxtaposition of orthogonally oriented nanofiber patterns on an isotropic surface is achieved with individual control of the fibers' main direction. In perspective, this photochemical method can be extended to a large variety of self‐assembling molecules.

Identifying Phase‐Dependent Electrochemical Stripping Performance of FeOOH Nanorod: Evidence from Kinetic Simulation and Analyte–Material Interactions

By Meng Yang, Yi‐Xiang Li, Min Jiang, Pei‐Hua Li, Shi‐Hua Chen, Jin‐Huai Liu, Chu‐Hong Lin, Xing‐Jiu Huang, Wen‐Qing Liu from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

α‐ and β‐FeOOH nanorods with diamond‐ and square‐shaped cross‐sections are synthesized. The phase‐dependent electrosensitivity toward Pb(II) on α‐FeOOH is about 17‐fold higher than β‐FeOOH. Combining kinetic simulation with analyte–material interaction studies, the kinetics in Pb(II) detection are identified, revealing that the phase‐dependent adsorption capacity is the main factor leading to distinct sensitivities on α‐ and β‐FeOOH. Abstract Metal hydroxide nanomaterials are widely applied in the energy and environment fields. The electrochemical performance of such materials is strongly dependent on their crystal phases. However, as there are always multiple factors relating to the phase‐dependent electrochemistry, it is still difficult to identify the determining one. The well‐defined crystal phases of α‐ and β‐FeOOH nanorods are characterized through the transmission electron microscopy by a series of rotation toward one rod, where the cross‐section shape and the growth direction along the [001] crystalline are first verified for 1D FeOOH nanostructures. The electrosensitivity of the two materials toward Pb(II) is tested, where α‐FeOOH performs an outstanding sensitivity whilst it is only modest for β‐FeOOH. Experiments via Fourier transform infrared spectroscopy, X‐ray absorption fine structure (XAFS), etc., show that α‐FeOOH presents a larger Pb(II) adsorption capacity due to more surficial hydroxyl groups and weaker PbO bond strength. The reaction kinetics are simulated and the adsorption capacity is found to be the determining factor for the distinct Pb(II) sensitivities. Combining experiment with simulation, this work reveals the physical insights of the phase‐dependent electrochemistry for FeOOH and provides guidelines for the functional application of metal hydroxide nanomaterials.

Photocatalytically Active Graphitic Carbon Nitride as an Effective and Safe 2D Material for In Vitro and In Vivo Photodynamic Therapy

By Hadiseh Taheri, Mehmet Altay Unal, Melike Sevim, Cansu Gurcan, Okan Ekim, Ahmet Ceylan, Zois Syrgiannis, Konstantinos C. Christoforidis, Susanna Bosi, Ozge Ozgenç, Manuel José Gómez, Mine Turktas Erken, Çigdem Soydal, Zafer Eroğlu, Ceylan Verda Bitirim, Umut Cagin, Fikret Arı, Asuman Ozen, Ozlem Kuçuk, Lucia Gemma Delogu, Maurizio Prato, Önder Metin, Açelya Yilmazer from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

Yilmazer and co‐workers show that photoexcitation of g‐C3N4 can be used effectively in a photodynamic therapy (PDT) protocol for cancer therapy without using any other nanocarrier, additional photosensitizer, or a chemotherapeutic drug. The efficacy of this g‐C3N4‐based system is evaluated for both in vitro and in vivo PDT by supporting the observed phenomenon through molecular mechanisms obtained via both transcriptomic and proteomic analysis. Abstract Thanks to its photocatalytic property, graphitic carbon nitride (g‐C3N4) is a promising candidate in various applications including nanomedicine. However, studies focusing on the suitability of g‐C3N4 for cancer therapy are very limited and possible underlying molecular mechanisms are unknown. Here, it is demonstrated that photoexcitation of g‐C3N4 can be used effectively in photodynamic therapy, without using any other carrier or additional photosensitizer. Upon light exposure, g‐C3N4 treatment kills cancer cells, without the need of any other nanosystem or chemotherapeutic drug. The material is efficiently taken up by tumor cells in vitro. The transcriptome and proteome of g‐C3N4 and light treated cells show activation in pathways related to both oxidative stress, cell death, and apoptosis which strongly suggests that only when combined with light exposure, g‐C3N4 is able to kill cancer cells. Systemic administration of the mesoporous form results in elimination from urinary bladder without any systemic toxicity. Administration of the material significantly decreases tumor volume when combined with local light treatment. This study paves the way for the future use of not only g‐C3N4 but also other 2D nanomaterials in cancer therapy.

A Unified Mechanism on the Formation of Acenes, Helicenes, and Phenacenes in the Gas Phase

By Long Zhao, Ralf I. Kaiser, Bo Xu, Utuq Ablikim, Musahid Ahmed, Mikhail M. Evseev, Eugene K. Bashkirov, Valeriy N. Azyazov, Alexander M. Mebel from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Cold comfort farm: Polycyclic aromatic hydrocarbons (PAHs) can be formed through molecular mass growth processes via ring annulation reactions at low temperatures. This mechanism, mediated through a barrierless, vinylacetylene based gas‐phase chemistry, challenges ideas that molecular mass growth processes to give PAHs require elevated temperatures. Abstract A unified low‐temperature reaction mechanism on the formation of acenes, phenacenes, and helicenes—polycyclic aromatic hydrocarbons (PAHs) that are distinct via the linear, zigzag, and ortho‐condensed arrangements of fused benzene rings—is revealed. This mechanism is mediated through a barrierless, vinylacetylene mediated gas‐phase chemistry utilizing tetracene, [4]phenacene, and [4]helicene as benchmarks contesting established ideas that molecular mass growth processes to PAHs transpire at elevated temperatures. This mechanism opens up an isomer‐selective route to aromatic structures involving submerged reaction barriers, resonantly stabilized free‐radical intermediates, and systematic ring annulation potentially yielding molecular wires along with racemic mixtures of helicenes in deep space. Connecting helicene templates to the Origins of Life ultimately changes our hypothesis on interstellar carbon chemistry.

Antibody‐Free Hydrogel with the Synergistic Effect of Cell Imprinting and Boronate Affinity: Toward the Selective Capture and Release of Undamaged Circulating Tumor Cells

By Lukuan Liu, Chengyong Dong, Xinwei Li, Senwu Li, Baofu Ma, Baofeng Zhao, Xiao Li, Zhen Liang, Kaiguang Yang, Lihua Zhang, Yukui Zhang from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

A universal strategy is proposed for the fabrication of an antibody‐free hydrogel that has a synergistic effect by featuring microinterfaces obtained by cell imprinting and molecular recognition conferred by boronate affinity. This 3‐AAPBA‐assisted cell‐imprinted hydrogel not only captures target tumor cells from blood with high efficiency and selectivity but also releases undamaged cells. Abstract The selective and highly efficient capture of circulating tumor cells (CTCs) from blood and their subsequent release without damage are very important for the early diagnosis of tumors and for understanding the mechanism of metastasis. Herein, a universal strategy is proposed for the fabrication of an antibody‐free hydrogel that has a synergistic effect by featuring microinterfaces obtained by cell imprinting and molecular recognition conferred by boronate affinity. With this artificial antibody, highly efficient capture of human hepatocarcinoma SMMC‐7721 cells is achieved: as many as 90.3 ± 1.4% (n = 3) cells are captured when 1 × 105 SMMC‐7721 cells are incubated on a 4.5 cm2 hydrogel, and 99% of these captured cells are subsequently released without any loss of proliferation ability. In the presence of 1000 times as many nontarget cells, namely, leukaemia Jurkat cells, the SMMC‐7721 cells can be captured with an enrichment factor as high as 13.5 ± 3.2 (n = 3), demonstrating the superior selectivity of the artificial antibody for the capture of the targeted CTCs. Most importantly, the SMMC‐7721 cells can be successfully captured even when spiked into whole blood, indicating the great promise of this approach for the further molecular characterization of CTCs.

ZIF‐8@ZIF‐67‐Derived Nitrogen‐Doped Porous Carbon Confined CoP Polyhedron Targeting Superior Potassium‐Ion Storage

By Yuyang Yi, Wen Zhao, Zhihan Zeng, Chaohui Wei, Chen Lu, Yuanlong Shao, Wenyue Guo, Shixue Dou, Jingyu Sun from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

ZIF‐8@ZIF‐67 derived nitrogen‐doped carbon confined CoP polyhedrons (NC@CoP/NC) are employed as an innovative potassium ion battery (KIB) anode material. Batteries fabricated using this material exhibit a high cycling stability (capacity retention of 93% after 100 cycles at 100 mA g−1) and an outstanding rate performance (≈200 mAh g−1 at 2000 mA g−1). Abstract Potassium ion batteries (KIB) have become a compelling energy‐storage system owing to their cost effectiveness and the high abundance of potassium in comparison with lithium. However, its practical applications have been thwarted by a series of challenges, including marked volume expansion and sluggish reaction kinetics caused by the large radius of potassium ions. In line with this, the exploration of reliable anode materials affording high electrical conductivity, sufficient active sites, and structural robustness is the key. The synthesis of ZIF‐8@ZIF‐67 derived nitrogen‐doped porous carbon confined CoP polyhedron architectures (NC@CoP/NC) to function as innovative KIB anode materials is reported. Such composites enable an outstanding rate performance to harvest a capacity of ≈200 mAh g−1 at 2000 mA g−1. Additionally, a high cycling stability can be gained by maintaining a high capacity retention of 93% after 100 cycles at 100 mA g−1. Furthermore, the potassium ion storage mechanism of the NC@CoP/NC anode is systematically probed through theoretical simulations and experimental characterization. This contribution may offer an innovative and feasible route of emerging anode design toward high performance KIBs.

Unveiling Latent Photoreactivity of Imines

By Daisuke Uraguchi, Yuto Tsuchiya, Tsuyoshi Ohtani, Takafumi Enomoto, Shigeyuki Masaoka, Daisuke Yokogawa, Takashi Ooi from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

The debut of the imines into photochemistry was escorted by the installation of an electron‐donating group at the imino carbon atom and an electron‐withdrawing group at the imino nitrogen atom to form a donor–acceptor (D‐A)‐type imine entity pertinent to extension of the excited‐state lifetime. Abstract Unlike carbonyl compounds, it has long been common understanding that excited imines show virtually no photoreactivity, and hence their properties and potential utility in chemical science remain largely unexplored. Now, a strategy is presented for eliciting latent photoreactivity of imines based on the introduction of a donor–acceptor (D‐A) structure to extend the lifetime of their photoexcited states. A series of spectroscopic analyses and density functional theory calculations reveal unique photophysical properties of the D‐A‐type imines. Furthermore, the reactivity of the D‐A‐type imines is demonstrated by using them as a photoredox catalyst for atom‐transfer radical addition. These findings illuminate a previously neglected chemical space in the field of photochemistry, which will be exploited by taking advantage of the inherent structural modularity of imines.

Self‐Assembly of Highly Stable Zirconium(IV) Coordination Cages with Aggregation Induced Emission Molecular Rotors for Live‐Cell Imaging

By Jinqiao Dong, Yutong Pan, Heng Wang, Kuiwei Yang, Lingmei Liu, Zhiwei Qiao, Yi Di Yuan, Shing Bo Peh, Jian Zhang, Leilei Shi, Hong Liang, Yu Han, Xiaopeng Li, Jianwen Jiang, Bin Liu, Dan Zhao from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Highly stable coordination cages with trinuclear zirconium vertices and flexible carboxyl‐decorated tetraphenylethylene (TPE) spacers were formed by self‐assembly. The two water‐stable cages exhibit impressive aggregation‐induced emission (AIE) characteristics contributed by the molecular rotors and can be employed as biological fluorescent probes for live‐cell imaging. Abstract The self‐assembly of highly stable zirconium(IV)‐based coordination cages with aggregation induced emission (AIE) molecular rotors for in vitro bio‐imaging is reported. The two coordination cages, NUS‐100 and NUS‐101, are assembled from the highly stable trinuclear zirconium vertices and two flexible carboxyl‐decorated tetraphenylethylene (TPE) spacers. Extensive experimental and theoretical results show that the emissive intensity of the coordination cages can be controlled by restricting the dynamics of AIE‐active molecular rotors though multiple external stimuli. Because the two coordination cages have excellent chemical stability in aqueous solutions (pH stability: 2–10) and impressive AIE characteristics contributed by the molecular rotors, they can be employed as novel biological fluorescent probes for in vitro live‐cell imaging.

Biosynthesis of the N–N‐Bond‐Containing Compound l‐Alanosine

By Menghua Wang, Haruka Niikura, Hai‐Yan He, Phillip Daniel‐Ivad, Katherine S. Ryan from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

A means to an N−N: Among N‐N‐bond‐containing compounds, biosynthetic routes to diazeniumdiolates remain enigmatic. The biosynthetic pathway for the diazeniumdiolate‐containing amino acid l‐alanosine was elucidated. The two nitrogen atoms in the diazeniumdiolate of l‐alanosine are shown to be derived from glutamic acid and aspartic acid, and the early steps of the biosynthetic pathway were elucidated by using both in vitro and in vivo approaches. Abstract The formation of a N−N bond is a unique biochemical transformation, and nature employs diverse biosynthetic strategies to activate nitrogen for bond formation. Among molecules that contain a N−N bond, biosynthetic routes to diazeniumdiolates remain enigmatic. We here report the biosynthetic pathway for the diazeniumdiolate‐containing amino acid l‐alanosine. Our work reveals that the two nitrogen atoms in the diazeniumdiolate of l‐alanosine arise from glutamic acid and aspartic acid, and we clarify the early steps of the biosynthetic pathway by using both in vitro and in vivo approaches. Our work demonstrates a peptidyl‐carrier‐protein‐based mechanism for activation of the precursor l‐diaminopropionate, and we also show that nitric oxide can participate in non‐enzymatic diazeniumdiolate formation. Furthermore, we demonstrate that the gene alnA, which encodes a fusion protein with an N‐terminal cupin domain and a C‐terminal AraC‐like DNA‐binding domain, is required for alanosine biosynthesis.

Visible‐Light‐Induced Selective Defluoroborylation of Polyfluoroarenes, gem‐Difluoroalkenes, and Trifluoromethylalkenes

By Wengang Xu, Heming Jiang, Jing Leng, Han‐Wee Ong, Jie Wu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

A practical and selective defluoroborylation of polyfluoroarenes, gem‐difluoroalkenes, and trifluoromethylalkenes was developed through photoredox and hydrogen atom transfer‐induced B−H activation to synthesize fluorinated organoboranes as the building blocks for value‐added organofluorine compounds. Abstract Fluorinated organoboranes serve as versatile synthetic precursors for the preparation of value‐added fluorinated organic compounds. Recent progress has been mainly focused on the transition‐metal catalyzed defluoroborylation. Herein, we report a photocatalytic defluoroborylation platform through direct B−H activation of N‐heterocyclic carbene boranes, through the synergistic merger of a photoredox catalyst and a hydrogen atom transfer catalyst. This atom‐economic and operationally simple protocol has enabled defluoroborylation of an extremely broad scope of multifluorinated substrates including polyfluoroarenes, gem‐difluoroalkenes, and trifluoromethylalkenes in a highly selective fashion. Intriguingly, the defluoroborylation protocol can be transition‐metal free, and the regioselectivity obtained is complementary to the reported transition‐metal‐catalysis in many cases.

Three‐dimensional Octameric Assembly of Icosahedral M13 Units in [Au8Ag57(Dppp)4(C6H11S)32Cl2]Cl and [Au8Ag55(Dppp)4(C6H11S)34][BPh4]2 Derivative

By Shan Jin, Manman Zhou, Xi Kang, Xiaowu Li, Wenjun Du, Xiao Wei, Shuang Chen, Shuxin Wang, Manzhou Zhu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

After the Gold Rush: Clusters of icosahedral M13 three‐dimensional (3D) assembly [Au8Ag57(Dppp)4(C6H11S)32Cl2]+, and its derivative [Au8Ag55(Dppp)4(C6H11S)34]2+, were synthesized. Interpenetration permits the assembly of icosahedral nanobuilding blocks and the 3D packing pattern of M13 units from low‐ to high‐dimensional clusters. Key: Dppp=1,3‐bis(diphenylphosphino)propane. Abstract The high‐dimensional (that is, three‐dimensional (3D)) assembly of nanomaterials is an effective means of improving their properties; however, achieving this assembly at the atomic level remains challenging. Herein, we obtained a novel nanocluster, [Au8Ag57(Dppp)4(C6H11S)32Cl2]Cl (Dppp=1,3‐bis(diphenylphosphino)propane) showing a 3D octameric assembly mode involving the kernel penetration of eight complete icosahedral Au@Ag10Au2 units for the first time. The atomically precise structure was determined by single‐crystal X‐ray diffraction, and further confirmed by thermogravimetric analysis, X‐ray photoelectron spectroscopy, and electrospray ionization mass spectrometry measurements. Furthermore, ligand‐induced transformation prompted the conversion of [Au8Ag57(Dppp)4(C6H11S)32Cl2]Cl, with complete octameric fusion into [Au8Ag55(Dppp)4(C6H11S)34][BPh4]2, with incomplete octameric fusion. These observations will hopefully facilitate further research on the assembly of M13 nanobuilding blocks.

Photocontrolled Iodine‐Mediated Reversible‐Deactivation Radical Polymerization System: Solution Polymerization of Methacrylates by Irradiation with NIR LED Light

By Chun Tian, Peng Wang, Yuanyuan Ni, Lifen Zhang, Zhenping Cheng, Xiulin Zhu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

At length: NIR photocontrolled iodine‐mediated reversible‐deactivation radical polymerization of various methacrylates, without an external photocatalyst, was developed under irradiation with 730 nm LED light at room temperature. 2‐Iodo‐2‐methylpropionitrile serves as the initiator and a special carbonyl solvent (e.g., 1,3‐dimethyl‐2‐imidazolidinone, DMI) serves as the catalyst. Abstract Herein, near‐infrared (NIR) photocontrolled iodide‐mediated reversible‐deactivation radical polymerization (RDRP) of methacrylates, without an external photocatalyst, was developed using an alkyl iodide (e.g., 2‐iodo‐2‐methylpropionitrile) as the initiator at room temperature. This example is the first use of a series of special solvents containing carbonyl groups (e.g., 1,3‐dimethyl‐2‐imidazolidinone) as both solvent and catalyst for photocontrolled RDRP using long‐wavelength (λmax=730 nm) irradiation. The polymerization system comprises monomer, alkyl iodide initiator, and solvent. Well‐defined polymers were synthesized with excellent control over the molecular weights and molecular weight distributions (Mw/Mn

A nano‐shield design for separators to resist dendrites of lithium metal battery

By Jie Liang, Qiyuan Chen, Xiangbiao Liao, Pengcheng Yao, Bin Zhu, Guangxin Lv, Xinyu Wang, Xi Chen, Jia Zhu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Lithium metal anodes are among the most promising candidates for high energy density batteries. However, the long‐standing issue of lithium dendrites growth during repeated charge and discharge cycles, which often leads to short circuit by puncturing the porous separator, impedes its practical application. Here, inspired by the defensive armor shield, we provide a morphological design “nano‐shield” for separators to resist dendrites. Through both mechanical analysis and experiment, it is revealed that the separator protected by this nano‐shield can effectively inhibit the penetration of lithium dendrites by reducing stress intensity and providing high tortuosity , a nd therefore mitigate the short circuit of Li metal batteries. More than 110 h of lithium plating life is achieved in Li/Li cell tests, which is among the longest cycle life of lithium metal anode and five times longer than that of blank separators. This new aspect of morphological and mechanical design combining both theoretical understanding and experimental results not only provides an alternative pathway for extending lifetime of lithium metal anodes, but also sheds a light on the role of separator engineering for various electrochemical energy storage devices .

Iridium‐catalyzed enantioselective hydrogenation of oxocarbenium ions: a case of ionic hydrogenation

By Tilong Yang, Yongjie Sun, Heng Wang, Zhenyang Lin, Jialin Wen, Xumu Zhang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Compared to the classic “inner‐sphere” transition metal catalyzed homogeneous hydrogenation reactions, ionic hydrogenation has been a far less explored area. This type of hydrogenation reaction, however, has its advantages for some challenging substrates such as unsaturated intermediates. We herein report an iridium‐catalyzed hydrogenation of oxocarbenium ions to afford chiral isochromans smoothly with high enantioselectivities. A variety of functionalities are compatible with this catalytic system. In the presence of catalytic amount of Brønsted acid HCl, α‐chloroether was in situ generated and subsequentially reduced. Kinetic studies suggested 1st‐order kinetics in the substrate and half‐order kinetics in the catalyst. A positive nonlinear effect, together with the half kinetic order, revealed a dimerization off the catalytic cycle. Several possible reaction pathways based on the monomeric iridium catalyst were proposed and DFT computational studies revealed an ionic hydrogenation pathway. Chloride abstraction and the cleavage of dihydrogen occur at the same step.

Radical Dehydroxymethylative Fluorination of Carbohydrates and Divergent Transformations of the Resulting Reverse Glycosyl Fluorides

By Xin Zhou, Han Ding, Pengwei Chen, Li Liu, Qikai Sun, Xianyang Wang, Peng Wang, Zhihua Lv, Ming Li from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Sweet fluorination: The radical dehydroxymethylative fluorination of carbohydrate alcohols affords a wide arrange of reverse glycosyl fluorides (RGFs) in good to excellent yields. Catalytic C−F bond activation of these products and further transformations with various nucleophiles demonstrate the potential of this method in late‐stage carbohydrate diversification. Abstract A mild and convenient method for the synthesis of reverse glycosyl fluorides (RGFs) has been developed that is based on the silver‐promoted radical dehydroxymethylative fluorination of carbohydrates. A salient feature of the reaction is that furanoid and pyranoid carbohydrates furnish structurally diverse RGFs bearing a wide variety of functional groups in good to excellent yields. Intramolecular hydrogen atom transfer experiments revealed that the reaction involves an underexploited radical fluorination that proceeds via β‐fragmentation of sugar‐derived primary alkoxyl radicals. Structurally divergent RGFs were obtained by catalytic C−F bond activation, and our method thus offers a concise and efficient strategy for the synthesis of reverse glycosides by late‐stage diversification of RGFs. The potential of this method is showcased by the preparation and diversification of sotagliflozin, leading to the discovery of a promising SGLT2 inhibitor candidate.

Phosphanylalanes and Phosphanylgallanes Stabilized only by a Lewis Base

By Michael A. K. Weinhart, Anna S. Lisovenko, Alexey Y. Timoshkin, Manfred Scheer from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Back to bases: The first parent phosphanylalanes and ‐gallanes stabilized only by a Lewis base were synthesized. These compounds are accessible via a salt metathesis reaction of LB⋅E′H2Cl and LiPH2⋅DME and a H2 elimination reaction between LB⋅E′H3 and PH3, respectively. Abstract The synthesis and characterization of the first parent phosphanylalane and phosphanylgallane stabilized only by a Lewis base (LB) are reported. The corresponding substituted compounds, such as IDipp⋅GaH2PCy2 (1) (IDipp=1,3‐bis(2,6‐diisopropylphenyl)‐imidazolin‐2‐ylidene) were obtained by the reaction of LiPCy2 with IDipp⋅GaH2Cl. However, the LB‐stabilized parent compounds IDipp⋅GaH2PH2 (3) and IDipp⋅AlH2PH2 (4) were prepared via a salt metathesis of LiPH2⋅DME with IDipp⋅E′H2Cl (E′=Ga, Al) or by H2‐elimination reactions of IDipp⋅E′H3 (E′=Ga, Al) and PH3, respectively. The compounds could be isolated as crystalline solids and completely characterized. Supporting DFT computations gave insight into the reaction pathways as well as into the stability of these compounds with respect to their decomposition behavior.

Crystallization‐Induced Reversal from Dark to Bright Excited States for Construction of Solid‐Emission‐Tunable Squaraines

By Shuaijun Yang, Ping‐An Yin, Lin Li, Qian Peng, Xinggui Gu, Ge Gao, Jingsong You, Ben Zhong Tang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

A unique squaraine, CIEE‐SQ, exhibits strong emission in the crystal, undergoing crystallization‐induced reverse from dark 1(n+σ,π*) to bright 1(π,π*) excited states. Such an excited state can be tuned by an unexpected temperature‐triggered single‐crystal to single‐crystal reversible transformation. Co‐crystallization between CIEE‐SQ and chloroform largely boosts the fluorescence. Abstract Squaraines (SQs) with tunable emission in the solid state is of great importance for various demands; however a remaining challenge is emission quenching upon aggregation. Herein, a unique SQ, named as CIEE‐SQ, is designed to exhibit strong emission in crystal, undergoing crystallization‐induced reverse from dark 1(n+σ,π*) to bright 1(π,π*) excited states. Such an excited state of CIEE‐SQ can be subtly tuned by molecular conformation changes during the unexpected temperature‐triggered single‐crystal to single‐crystal (SCSC) reversible transformation. Furthermore, co‐crystallization between CIEE‐SQ and chloroform largely stabilize the 1(π,π*) state, enhancing the transition dipole moment and decreasing the reorganization energy to boost the fluorescence, which is promising in data encryption and decryption.

Cooperative Catalysis for the Highly Diastereo‐ and Enantioselective [4+3]‐Cycloannulation of ortho‐Quinone Methides and Carbonyl Ylides

By Arun Suneja, Henning Jakob Loui, Christoph Schneider from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

It takes two: A combination of Rh2(OAc)4 and a chiral phosphoric acid catalyzes the in situ generation of transient carbonyl ylides and chiral hydrogen‐bonded ortho‐quinone methides through cooperative catalytic cycles. These transient species then undergo a highly diastereo‐ and enantioselective cycloannulation to afford a broad range of functionalized oxa‐bridged dibenzooxacines featuring two quaternary and one tertiary stereogenic centers. Abstract We describe herein a highly diastereo‐ and enantioselective [4+3]‐cycloannulation of ortho‐quinone methides and carbonyl ylides to furnish functionalized oxa‐bridged dibenzooxacines with excellent yields and stereoselectivity in a single synthetic step. The combination of rhodium and chiral phosphoric acid catalysis working in concert to generate both transient intermediates in situ provides direct access to complex bicyclic products with two quaternary and one tertiary stereogenic centers. The products may be further functionalized into valuable and enantiomerically highly enriched building blocks.

Mechanical Distension Induces Serotonin Release from Intestine as Revealed by Stretchable Electrochemical Sensing

By Yan‐Ling Liu, Yan Chen, Wen‐Ting Fan, Pan Cao, Jing Yan, Xing‐Zhong Zhao, Wei‐Guo Dong, Wei‐Hua Huang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

The role of endogenous serotonin in different intestinal motility patterns is highly controversial. A stretchable sensor with high sensitivity, and antifouling and decontamination properties is presented. The sensor was inserted into the lumen of an intestine model to achieve real‐time monitoring of distension‐evoked serotonin release. Abstract The role of endogenous serotonin (5‐HT) in gastrointestinal motility is still highly controversial. Although electrochemical techniques allow for direct and real‐time recording of biomolecules, the dynamic monitoring of 5‐HT release from elastic and tubular intestine during motor reflexes remains a great challenge because of the specific peristalsis patterns and inevitable passivation of the sensing interface. A stretchable sensor with antifouling and decontamination properties was assembled from gold nanotubes, titanium dioxide nanoparticles, and carbon nanotubes. The sandwich‐like structure endowed the sensor with satisfying mechanical stability and electrochemical performance, high resistance against physical adsorption, and superior efficiency in the photodegradation of biofouling molecules. Insertion of the sensor into the lumen of rat ileum (the last section of the small intestine) successfully mimics intestinal peristalsis, and simultaneous real‐time monitoring of distension‐evoked 5‐HT release was possible for the first time. Our results unambiguously reveal that mechanical distension of the intestine induces endogenous 5‐HT overflow, and 5‐HT level is closely associated with the physiological or pathological states of the intestine.

Chirality‐Driven Transportation and Oxidation Prevention by Chiral Selenium Nanoparticles

By Yanyu Huang, Yuanting Fu, Mengting Li, Dawei Jiang, Christopher J. Kutyreff, Jonathan W. Engle, Xiaoli Lan, Weibo Cai, Tianfeng Chen from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

From benchtop to bedside? Selenium nanoparticles decorated with glutathione enantiomers (l‐, d‐, and dl‐forms) display distinct biodistributions in mice as determined by PET imaging with 64Cu‐radiolabeling. One extrapolation of this selectivity is that l‐G@SeNPs prevent palmitic acid caused oxidative damage by facilitative uptake into insulinoma cells. Abstract The chirality of nanoparticles directly influences their transport and biological effects under physiological conditions, but the details of this phenomenon have rarely been explored. Herein, chiral GSH‐anchored selenium nanoparticles (G@SeNPs) are fabricated to investigate the effect of their chirality on their transport and antioxidant activity. G@SeNPs modified with different enantiomers show opposite handedness with a tunable circular dichroism signal. Noninvasive positron emission tomography imaging clearly reveals that 64Cu‐labeled l‐G@SeNPs experience distinctly different transport among the major organs from that of their d‐and dl‐counterparts, demonstrating that the chirality of the G@SeNPs influences the biodistribution and kinetics. Taking advantage of the strong homologous cell adhesion and uptake, l‐G@SeNPs have been shown here to effectively prevent oxidation damage caused by palmitic acid in insulinoma cells.

Molecularly Engineered Macrophage‐Derived Exosomes with Inflammation Tropism and Intrinsic Heme Biosynthesis for Atherosclerosis Treatment

By Guanghao Wu, Jinfeng Zhang, Qianru Zhao, Wanru Zhuang, Jingjing Ding, Chi Zhang, Haijun Gao, Dai‐Wen Pang, Kanyi Pu, Hai‐Yan Xie from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

M2 macrophage‐derived exosomes molecularly engineered with the drug hexyl 5‐aminolevulinate hydrochloride (HAL) can actively target and transmigrate to atherosclerotic lesions, wherein the biosynthesis and metabolism of heme induced by HAL produces CO and bilirubin. This, along with the anti‐inflammatory cytokines in exosomes, acts to significantly alleviate atherosclerosis. Abstract Atherosclerosis (AS) is a major contributor to cardiovascular diseases worldwide, and alleviating inflammation is a promising strategy for AS treatment. Here, we report molecularly engineered M2 macrophage‐derived exosomes (M2 Exo) with inflammation‐tropism and anti‐inflammatory capabilities for AS imaging and therapy. M2 Exo are derived from M2 macrophages and further electroporated with FDA‐approved hexyl 5‐aminolevulinate hydrochloride (HAL). After systematic administration, the engineered M2 Exo exhibit excellent inflammation‐tropism and anti‐inflammation effects via the surface‐bonded chemokine receptors and the anti‐inflammatory cytokines released from the anti‐inflammatory M2 macrophages. Moreover, the encapsulated HAL can undergo intrinsic biosynthesis and metabolism of heme to generate anti‐inflammatory carbon monoxide and bilirubin, which further enhance the anti‐inflammation effects and finally alleviate AS. Meanwhile, the intermediate protoporphyrin IX (PpIX) of the heme biosynthesis pathway permits the fluorescence imaging and tracking of AS.

Uncovering the Shuttle Effect in Organic Batteries and Counter‐Strategies Thereof: A Case Study of the N,N′‐Dimethylphenazine Cathode

By Vincent Wing‐hei Lau, Igor Moudrakovski, Junghoon Yang, Jiliang Zhang, Yong‐Mook Kang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Whodunnit? The detrimental shuttle effect in organic batteries is proposed to be based on electron hopping through a self‐exchange process, rather than by molecular diffusion as conventionally understood. The findings have led to two counter‐strategies to inhibit this shuttle mechanism. Abstract The main drawback of organic electrode materials is their solubility in the electrolyte, leading to the shuttle effect. Using N,N′‐dimethylphenazine (DMPZ) as a highly soluble cathode material, and its PF6− and triflimide salts as models for its first oxidation state, a poor correlation was found between solubility and battery operability. Extensive electrochemical experiments suggest that the shuttle effect is unlikely to be mediated by molecular diffusion as commonly understood, but rather by electron‐hopping via the electron self‐exchange reaction based on spectroscopic results. These findings led to two counter‐strategies to prevent the hopping process: the pre‐treatment of the anode to form a solid–electrolyte interface and using DMPZ salt rather than neutral DMPZ as the active material. These strategies improved coulombic efficiency and capacity retention, demonstrating that solubility of organic materials does not necessarily exclude their applications in batteries.

Molecular‐Sieving Membrane by Partitioning the Channels in Ultrafiltration Membrane by In Situ Polymerization

By Pengpeng Shao, Ruxin Yao, Ge Li, Mengxi Zhang, Shuai Yuan, Xiaoqi Wang, Yuhao Zhu, Xianming Zhang, Lin Zhang, Xiao Feng, Bo Wang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Confined‐polymerization partitioning in commercial ultrafiltration membrane pores is reported to prepare gas molecular‐sieving membranes. Besides remarkable hydrogen purification performance, outstanding long‐term stability and aging resistance are achieved owing to the creation of intrinsic micropores by crosslinking of multi‐functionalized rigid building units. Abstract Commercial ultrafiltration membranes have proliferated globally for water treatment. However, their pore sizes are too large to sieve gases. Conjugated microporous polymers (CMPs) feature well‐developed microporosity yet are difficult to be fabricated into membranes. Herein, we report a strategy to prepare molecular‐sieving membranes by partitioning the mesoscopic channels in water ultrafiltration membrane (PSU) into ultra‐micropores by space‐confined polymerization of multi‐functionalized rigid building units. Nine CMP@PSU membranes were obtained, and their separation performance for H2/CO2, H2/N2, and H2/CH4 pairs surpass the Robeson upper bound and rival against the best of those reported membranes. Furthermore, highly crosslinked skeletons inside the channels result in the structural robustness and transfer into the excellent aging resistance of the CMP@PSU. This strategy may shed light on the design and fabrication of high‐performance polymeric gas separation membranes.

Ruthenium(II)‐Catalyzed Asymmetric Inert C−H Bond Activation Assisted by a Chiral Transient Directing Group

By Guozhu Li, Qinzhe Liu, Laxmaiah Vasamsetty, Weicong Guo, Jun Wang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Assisted by a chiral transient directing group, a highly enantioselective ruthenium‐catalyzed intramolecular hydroarylation, by means of an inert C−H activation process, has been realized in up to 98 % yield and 99 % ee by using the readily available and inexpensive metal catalyst [Ru(p‐cymene)Cl2]2 (5 mol %) and a chiral primary amine (20 mol %). Abstract A ruthenium(II)‐catalyzed asymmetric intramolecular hydroarylation assisted by a chiral transient directing group has been developed. A series of 2,3‐dihydrobenzofurans bearing chiral all‐carbon quaternary stereocenters have been prepared in remarkably high yields (up to 98 %) and enantioselectivities (up to >99 % ee). By this methodology, a novel asymmetric total synthesis of CB2 receptor agonist MDA7 has been successfully developed.

Photodissociation Mechanisms of Major Mercury(II) Species in the Atmospheric Chemical Cycle of Mercury

By Antonio Francés‐Monerris, Javier Carmona‐García, A. Ulises Acuña, Juan Z. Dávalos, Carlos A. Cuevas, Douglas E. Kinnison, Joseph S. Francisco, Alfonso Saiz‐Lopez, Daniel Roca‐Sanjuán from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

The ultimate fate of mercury in the atmosphere is elemental Hg. This result is based on non‐adiabatic dynamics simulations, which were used to construct a complete quantitative mechanism of the photochemical and thermal conversion of atmospheric HgII, HgI, and Hg0 compounds. Abstract Mercury is a contaminant of global concern that is transported throughout the atmosphere as elemental mercury Hg0 and its oxidized forms HgI and HgII. The efficient gas‐phase photolysis of HgII and HgI has recently been reported. However, whether the photolysis of HgII leads to other stable HgII species, to HgI, or to Hg0 and its competition with thermal reactivity remain unknown. Herein, we show that all oxidized forms of mercury rapidly revert directly and indirectly to Hg0 by photolysis. Results are based on non‐adiabatic dynamics simulations, in which the photoproduct ratios were determined with maximum errors of 3%. We construct for the first time a complete quantitative mechanism of the photochemical and thermal conversion between atmospheric HgII, HgI, and Hg0 compounds. These results reveal new fundamental chemistry that has broad implications for the global atmospheric Hg cycle. Thus, photoreduction clearly competes with thermal oxidation, with Hg0 being the main photoproduct of HgII photolysis in the atmosphere, which significantly increases the lifetime of this metal in the environment.

A Supramolecular‐Based Dual‐Wavelength Phototherapeutic Agent with Broad‐Spectrum Antimicrobial Activity Against Drug‐Resistant Bacteria

By Zhi‐Hao Yu, Xingshu Li, Fugui Xu, Xi‐Le Hu, Jiatao Yan, Nahyun Kwon, Guo‐Rong Chen, Tingting Tang, Xiaojing Dong, Yiyong Mai, Daijie Chen, Juyoung Yoon, Xiao‐Peng He, He Tian from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Antibacterial steamroller: Polycationic porphyrin and water‐dispersible graphene nanoribbons self‐assemble into a supramolecular nanocomposite that combines both photodynamic and photothermal therapy for the treatment of bacterial infections. The nanocomposite exhibits an impressive antimicrobial activity that leads to the complete annihilation of a wide spectrum of Gram‐positive, Gram‐negative, and drug‐resistant bacteria. Abstract With the ever‐increasing threat posed by the multi‐drug resistance of bacteria, the development of non‐antibiotic agents for the broad‐spectrum eradication of clinically prevalent superbugs remains a global challenge. Here, we demonstrate the simple supramolecular self‐assembly of structurally defined graphene nanoribbons (GNRs) with a cationic porphyrin (Pp4N) to afford unique one‐dimensional wire‐like GNR superstructures coated with Pp4N nanoparticles. This Pp4N/GNR nanocomposite displays excellent dual‐modal properties with significant reactive‐oxygen‐species (ROS) production (in photodynamic therapy) and temperature elevation (in photothermal therapy) upon light irradiation at 660 and 808 nm, respectively. This combined approach proved synergistic, providing an impressive antimicrobial effect that led to the complete annihilation of a wide spectrum of Gram‐positive, Gram‐negative, and drug‐resistant bacteria both in vitro and in vivo. The study also unveils the promise of GNRs as a new platform to develop dual‐modal antimicrobial agents that are able to overcome antibiotic resistance.

A Supported Bismuth Halide Perovskite Photocatalyst for Selective Aliphatic and Aromatic C–H Bond Activation

By Yitao Dai, Corentin Poidevin, Cristina Ochoa‐Hernández, Alexander A. Auer, Harun Tüysüz from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Better with bismuth: A range of mesoporous‐silica‐supported small bismuth halide perovskite nanoparticles were prepared. They were found to be very promising photocatalysts for selective aromatic and aliphatic C−H bond activation under visible‐light illumination. Abstract Direct selective oxidation of hydrocarbons to oxygenates by O2 is challenging. Catalysts are limited by the low activity and narrow application scope, and the main focus is on active C−H bonds at benzylic positions. In this work, stable, lead‐free, Cs3Bi2Br9 halide perovskites are integrated within the pore channels of mesoporous SBA‐15 silica and demonstrate their photocatalytic potentials for C−H bond activation. The composite photocatalysts can effectively oxidize hydrocarbons (C5 to C16 including aromatic and aliphatic alkanes) with a conversion rate up to 32900 μmol gcat−1 h−1 and excellent selectivity (>99 %) towards aldehydes and ketones under visible‐light irradiation. Isotopic labeling, in situ spectroscopic studies, and DFT calculations reveal that well‐dispersed small perovskite nanoparticles (2–5 nm) possess enhanced electron–hole separation and a close contact with hydrocarbons that facilitates C(sp3)−H bond activation by photoinduced charges.

Phenol‐Derived Carbon Sealant Inspired by a Coalification Process

By Yunhan Lee, Kiwoo Jun, Kyueui Lee, Young Chang Seo, Changyoung Jeong, Munja Kim, Il‐Kwon Oh, Haeshin Lee from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

The phenol‐derived carbon sealant inspired by the coalification process was developed by thermal annealing of a polyphenolic compounds. The compounds undergo oxidation for surface functionalization and the reductive annealing for developing electrically conductive properties. The resulting sealant, which is a conductive graphitic carbon material, can seal graphene fragments physically and electrically. Abstract Recently, emerging functions utilizing phenolic molecules, such as surface functionalizing agents or bioadhesives, have attracted significant interest. However, the most important role of phenolic compounds is to produce carbonized plant matter called “coal”, which is widely used as an energy source in nearly all countries. Coalification is a long‐term, high‐temperature process in which phenols are converted into conducting carbonized matter. This study focuses on mimicking coalification processes to create conducting sealants from non‐conducting phenolic compounds by heat treatment. We demonstrate that a phenolic adhesive, tri‐hydroxybenzene (known as pyrogallol), and polyethylenimine mixture initially acts as an adhesive sealant that can be converted to a conducting carbon sealing material. The conductivity of the phenolic sealant is about 850 Ω−1 cm−1, which is an approximately two‐fold enhancement of the performance of carbon matter. Applications of the biomimetic adhesives described herein include conducting defect sealants in carbon nanomaterials and conducting binders for metal/carbon or ceramic/carbon composites.

Enriching and Quantifying Porous Single Layer 2D Polymers by Exfoliation of Chemically Modified van der Waals Crystals

By Ralph Z. Lange, Kevin Synnatschke, Haoyuan Qi, Niklas Huber, Gregor Hofer, Baokun Liang, Christian Huck, Annemarie Pucci, Ute Kaiser, Claudia Backes, A. Dieter Schlüter from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

A 2D polymer with pyrylium groups is transformed into a 2D polymer with pyridine groups by exposure to gaseous ammonia. Liquid phase exfoliation of the latter yields nanosheet dispersions, which can be size‐selected using centrifugation cascades. Nanosheet quantification shows that the exfoliation is comparable to graphite, demonstrating the promising potential of this approach, which could also be applied to covalent organic frameworks. Abstract 2D polymer sheets with six positively charged pyrylium groups at each pore edge in a stacked single crystal can be transformed into a 2D polymer with six pyridines per pore by exposure to gaseous ammonia. This reaction furnishes still a crystalline material with tunable protonation degree at regular nano‐sized pores promising as separation membrane. The exfoliation is compared for both 2D polymers with the latter being superior. Its liquid phase exfoliation yields nanosheet dispersions, which can be size‐selected using centrifugation cascades. Monolayer contents of ≈30 % are achieved with ≈130 nm sized sheets in mg quantities, corresponding to tens of trillions of monolayers. Quantification of nanosheet sizes, layer number and mass shows that this exfoliation is comparable to graphite. Thus, we expect that recent advances in exfoliation of graphite or inorganic crystals (e.g. scale‐up, printing etc.) can be directly applied to this 2D polymer as well as to covalent organic frameworks.

Target Self‐Enhanced Selectivity in Metal‐Specific DNAzymes

By Po‐Jung Jimmy Huang, Donatien Rochambeau, Hanadi F. Sleiman, Juewen Liu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

The more the merrier: Better selectivity for Zn2+ ions is shown for DNAzymes that bind more metal ions. This selectivity is exemplified by using a series of in vitro selected DNAzymes that contain a single metal ligand modification at the cleavage junction. Abstract Highly selective recognition of metal ions by rational ligand design is challenging, and simple metal binding by biological ligands is often obscured by nonspecific interactions. In this work, binding‐triggered catalysis is used and metal selectivity is greatly increased by increasing the number of metal ions involved, as exemplified in a series of in vitro selected RNA‐cleaving DNAzymes. The cleavage junction is modified with a glycyl–histidine‐functionalized tertiary amine moiety to provide multiple potential metal coordination sites. DNAzymes that bind 1, 2, and 3 Zn2+ ions, increased their selectivity for Zn2+ over Co2+ ions from approximately 20‐, 1000‐, to 5000‐fold, respectively. This study offers important insights into metal recognition by combining rational ligand design and combinatorial selection, and it provides a set of new DNAzymes with excellent selectivity for Zn2+ ions.

Nickel Poisoning of a Cracking Catalyst Unravelled by Single‐Particle X‐ray Fluorescence‐Diffraction‐Absorption Tomography

By Marianna Gambino, Martin Veselý, Matthias Filez, Ramon Oord, Dario Ferreira Sanchez, Daniel Grolimund, Nikolai Nesterenko, Delphine Minoux, Marianne Maquet, Florian Meirer, Bert M. Weckhuysen from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

The young poisoner′s handbook: X‐ray fluorescence, diffraction and absorption (μXRF‐μXRD‐μXAS) tomography and confocal fluorescence microscopy (CFM) are combined as a powerful method to determine the effect of Ni poisoning within real‐life fluid catalytic cracking (FCC) catalyst single particles. Abstract Ni contamination from crude oil in the fluid catalytic cracking (FCC) process is one of the primary sources of catalyst deactivation, thereby promoting dehydrogenation–hydrogenation and speeding up coke growth. Herein, single‐particle X‐ray fluorescence, diffraction and absorption (μXRF‐μXRD‐μXAS) tomography is used in combination with confocal fluorescence microscopy (CFM) after thiophene staining to spatially resolve Ni interaction with catalyst components and study zeolite degradation, including the processes of dealumination and Brønsted acid sites distribution changes. The comparison between a Ni‐lean particle, exposed to hydrotreated feedstock, and a Ni‐rich one, exposed to non‐hydrotreated feedstock, reveals a preferential interaction of Ni, found in co‐localization with Fe, with the γ‐Al2O3 matrix, leading to the formation of spinel‐type hotspots. Although both particles show similar surface zeolite degradation, the Ni‐rich particle displays higher dealumination and a clear Brønsted acidity drop.

Covalent Adaptable Networks with Tunable Exchange Rates Based on Reversible Thiol–yne Cross‐Linking

By Niels Van Herck, Diederick Maes, Kamil Unal, Marc Guerre, Johan M. Winne, Filip E. Du Prez from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Controlling reactivity: Reversible thiol–yne cross‐linking is enabled via the double Michael addition of thiols on activated alkynes. The rate of dynamic thiol exchange is manipulated by means of electronic substituents on the activated alkyne, offering a new versatile dynamic platform for the development of covalent adaptable networks. Abstract The design of covalent adaptable networks (CANs) relies on the ability to trigger the rearrangement of bonds within a polymer network. Simple activated alkynes are now used as versatile reversible cross‐linkers for thiols. The click‐like thiol–yne cross‐linking reaction readily enables network synthesis from polythiols through a double Michael addition with a reversible and tunable second addition step. The resulting thioacetal cross‐linking moieties are robust but dynamic linkages. A series of different activated alkynes have been synthesized and systematically probed for their ability to produce dynamic thioacetal linkages, both in kinetic studies of small molecule models, as well as in stress relaxation and creep measurements on thiol–yne‐based CANs. The results are further rationalized by DFT calculations, showing that the bond exchange rates can be significantly influenced by the choice of the activated alkyne cross‐linker.

Stabilization of the Oxidation State +IV in Siloxide‐Supported Terbium Compounds

By Aurélien R. Willauer, Chad T. Palumbo, Rosario Scopelliti, Ivica Zivkovic, Iskander Douair, Laurent Maron, Marinella Mazzanti from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

TbIV is here to stay: The terbium(IV) complex [Tb(OSiPh3)4(MeCN)2] contains labile ligands but shows high stability as a result of a strong π(O−Tb) interaction. Non‐binding counterions contribute to the stability of TbIV in solution by destabilizing the oxidation state +III, while alkali ions promote TbIV/TbIII electron transfer. Abstract The synthesis of lanthanides other than cerium in the oxidation state +IV has remained a desirable but unmet target until recently, when two examples of TbIV with saturated coordination spheres were isolated. Here we report the third example of an isolated molecular complex of terbium(IV), where the supporting siloxide ligands do not saturate the coordination sphere. The fully characterized six‐coordinate complex [TbIV(OSiPh3)4(MeCN)2], 2‐TbPh, shows high stability and the labile MeCN ligands can be replaced by phosphinoxide ligands. Computational studies suggest that the stability is due to a strong π(O−Tb) interaction which is stronger than in the previously reported TbIV complexes. Cyclic‐voltammetry experiments demonstrate that non‐binding counterions contribute to the stability of TbIV in solution by destabilizing the +III oxidation state, while alkali ions promote TbIV/TbIII electron transfer.

Polymerizations Mediated by Well‐Defined Rhodium Complexes

By Nicholas Sheng Loong Tan, Andrew B. Lowe from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Rhodium chains: This Minireview details the current state‐of‐the‐art relating to (co)polymerizations mediated by well‐defined RhI‐ethynyl, vinyl, and aryl complexes. The focus is on RhI species suitable for the (co)polymerization of phenylacetylenes, arylisocyanides, as well as propargyl esters and amides. Abstract This Minireview details the current state‐of‐the‐art relating to (co)polymerizations mediated by well‐defined RhI‐ethynyl, vinyl, and aryl complexes. In particular, we focus on RhI species suitable for the (co)polymerization of phenylacetylenes, arylisocyanides, as well as propargyl esters and amides.

[SnI8{Fe(CO)4}4]2+: Highly Coordinated Sn+III8 Subunit with Fragile Carbonyl Clips

By Silke Wolf, Ralf Köppe, Theresa Block, Rainer Pöttgen, Peter W. Roesky, Claus Feldmann from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

You're clinging! In a clip‐like fashion, Fe(CO)4 groups surround a central SnI8 subunit in [SnI8{Fe(CO)4}4]2+, which has an unprecedentedly high coordination of tin with the most voluminous, stable halide. Abstract [SnI8{Fe(CO)4}4][Al2Cl7]2 contains the [SnI8{Fe(CO)4}4]2+ cation with an unprecedented highly coordinated, bicapped SnI8 prism. Given the eightfold coordination with the most voluminous stable halide, it is all the more surprising that this SnI8 arrangement is surrounded only by fragile Fe(CO)4 groups in a clip‐like fashion. Inspite of a predominantly ionic bonding situation in [SnI8{Fe(CO)4}4]2+, the I−⋅⋅⋅I− distances are considerably shortened (down to 371 pm) and significantly less than the van der Waals distance (420 pm). The title compound is characterized by single‐crystal structure analysis, spectroscopic methods (EDXS, FTIR, Raman, UV/Vis, Mössbauer), thermogravimetry, and density functional theory methods.

Philip Leverhulme Prizes for Chemistry 2019

By from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Gold‐Catalyzed Atroposelective Synthesis of 1,1′‐Binaphthalene‐2,3′‐diols

By Jianwei Zhang, Martin Simon, Christopher Golz, Manuel Alcarazo from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Remote control: Two methyl groups strategically located at the backbone of the imidazolium component of a gold‐based catalyst are essential to deliver the desired binapthol compounds in up to 97 % ee. Abstract A highly atroposelective (up to 97 % ee) Au‐catalyzed synthesis of 1,1′‐binaphthalene‐2,3′‐diols is reported starting from a range of substituted benzyl alkynones. Essential for the achievement of high enantioselectivity during the key assembly of the naphto‐3‐ol unit is the use of TADDOL‐derived α‐cationic phosphonites as ancillary ligands. Preliminary results demonstrate that the transformation of the obtained binaphthyls into axially chiral monodentate phosphines is possible without degradation of enantiopurity.

Selective Expression of Chromophores in a Single Molecule: Soft Organic Crystals Exhibiting Full‐Colour Tunability and Dynamic Triplet‐Exciton Behaviours

By Wenlang Li, Qiuyi Huang, Zhu Mao, Juan Zhao, Huiyan Wu, Junru Chen, Zhan Yang, Yang Li, Zhiyong Yang, Yi Zhang, Matthew P. Aldred, Zhenguo Chi from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Crystal clear colours: Selective expression of chromophores is achieved in a soft organic molecule. In response to various external stimuli, full‐colour emissions from ten different individual single crystals and dynamic triplet‐exciton behaviours can be realized via the competition between different chromophores for emission. Abstract Soft luminescent materials are attractive for optoelectronic applications, however, switching dominant chromophores for property enrichment remains a challenge. Herein, we report the first case of a soft organic molecule (DOS) featuring selective expression of chromophores. In response to various external stimuli, different chromophores of DOS can take turns working through conformation changes, exhibiting full‐colour emissions peaking from 469 nm to 583 nm from ten individual single crystals. Dynamic triplet‐exciton behaviours including thermally activated delayed fluorescence (TADF), room‐temperature phosphorescence (RTP), mechanoluminescence (ML), and distinct mechano‐responsive luminescence (MRL) can all be realized. This novel designed DOS molecule provides a multifunctional platform for detection of volatile organic compounds (VOCs), multicolour dynamic displays, sensing, anticounterfeiting, and hopefully many others.

Tue 04 Feb 10:00: Reversible Catalysis in Redox Matrices

From Materials Chemistry Research Interest Group. Published on Jan 23, 2020.

Reversible Catalysis in Redox Matrices

Abstract not available

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Tue 04 Feb 10:00: Reversible Catalysis in Redox Matrices

From All Talks (aka the CURE list). Published on Jan 23, 2020.

Reversible Catalysis in Redox Matrices

Abstract not available

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Determination of complex small molecule structures using molecular alignment simulation

By Alain Ibáñez de Opakua, Frederik Klama, Ikenna E Ndukwe, Gary E Martin, Thomas R Williamson, Markus Zweckstetter from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 23, 2020.

Correct structural assignment of small molecules and natural products is critical for drug discovery and organic chemistry. Anisotropy‐based NMR spectroscopy is a powerful tool for structural assignment of organic molecules, but relies on utilization of a medium that disrupts the isotropic motion of molecules in organic solvents. Here, we establish a quantitative correlation between the atomic structure of the alignment medium, the molecular structure of the small molecule and molecule‐specific anisotropic NMR parameters. The quantitative correlation uses an accurate three‐dimensional molecular alignment model that predicts residual dipolar couplings of small molecules aligned by poly( γ ‐benzyl‐ʟ‐glutamate). The technique facilitates reliable determination of the correct stereoisomer and enables unequivocal, rapid determination of complex molecular structures from extremely sparse NMR   data.

Circulating Exosomal miR‐20b‐5p Inhibition Restores Wnt9b Signaling and Reverses Diabetes‐Associated Impaired Wound Healing

By Yuan Xiong, Lang Chen, Chenchen Yan, Wu Zhou, Yori Endo, Jing Liu, Liangcong Hu, Yiqiang Hu, Bobin Mi, Guohui Liu from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

The study results suggest that diabetic plasma exosomes inhibit cutaneous wound healing by influencing the angiogenic activity of vascular endothelial cells both in vitro and in vivo. The enrichment of miR‐20b‐5p in exosomes plays an important role in impairing wound healing via inhibition of the Wnt9b/β‐catenin signaling pathway. Abstract At present, developing therapeutic strategies to improve wound healing in individuals with diabetes remains challenging. Exosomes represent a promising nanomaterial from which microRNAs (miRNAs) can be isolated. These miRNAs have the potential to exert therapeutic effects, and thus, determining the potential therapeutic contributions of specific miRNAs circulating in exosomes is of great importance. In the present study, circulating exosomal miRNAs are identified in diabetic patients and assessed for their roles in the context of diabetic wound healing. A significant upregulation of miR‐20b‐5p is observed in exosomes isolated from patients with type 2 diabetes mellitus (T2DM), and this miRNA is able to suppress human umbilical vein endothelial cell angiogenesis via regulation of Wnt9b/β‐catenin signaling. It is found that the application of either miR‐20b‐5p or diabetic exosomes to wound sites is sufficient to slow wound healing and angiogenesis. In diabetic mice, it is found that knocking out miR‐20b‐5p significantly enhances wound healing and promotes wound angiogenesis. Together, these findings thus provide strong evidence that miR‐20b‐5p is highly enriched in exosomes from patients with T2DM and can be transferred to cells of the vascular endothelium, where it targets Wnt9b signaling to negatively regulate cell functionality and angiogenesis.

Direct Growth of Perovskite Crystals on Metallic Electrodes for High‐Performance Electronic and Optoelectronic Devices

By Jia Liu, Fengjing Liu, Haining Liu, Rui Hou, Junyi Yue, Jinzhong Cai, Zhisheng Peng, Julienne Impundu, Liming Xie, Yong Jun Li, Lianfeng Sun from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

A strategy is proposed to construct high‐performance electronic and optoelectronic devices by directly growing perovskite crystals on microscale prepatterned metallic electrodes in liquid phase. The well‐contacted perovskite/metal interfaces ensure these heterostructures to serve as high‐performance field effect transistors and excellent photodetector devices, where the photoconductive response is proved to be band‐bending‐assisted separation of photoexcited carriers at Schottky barrier. Abstract Metal halide perovskite has attracted enhanced interest for its diverse electronic and optoelectronic applications. However, the fabrication of micro‐ or nanoscale crystalline perovskite functional devices remains a great challenge due to the fragility, solvent, and heat sensitivity of perovskite crystals. Here, a strategy is proposed to fabricate electronic and optoelectronic devices by directly growing perovskite crystals on microscale metallic structures in liquid phase. The well‐contacted perovskite/metal interfaces ensure these heterostructures serve as high‐performance field effect transistors (FETs) and excellent photodetector devices. When serving as an FET, the on/off ratio is as large as 106 and the mobility reaches up to ≈2.3 cm2 V−1 s−1. A photodetector is displayed with high photoconductive switching ratio of ≈106 and short response time of ≈4 ms. Furthermore, the photoconductive response is proved to be band‐bending‐assisted separation of photoexcited carriers at the Schottky barrier of the silver and p‐type perovskites.

The Regulatory Functionality of Exosomes Derived from hUMSCs in 3D Culture for Alzheimer's Disease Therapy

By Lingyan Yang, Yuanxin Zhai, Ying Hao, Zhanchi Zhu, Guosheng Cheng from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

The 3D scaffold as cultural matrix has a significant impact on the expressions of miRNAs and proteins in human umbilical cord mesenchymal stem cells‐derived exosomes compared to that by the conventional 2D culture system. Through their special cargos, exosomes derived from 3D culture could effectively reduce Aβ accumulation and ameliorate cognitive decline, exhibiting great potential in Alzheimer's disease therapy. Abstract Reducing amyloid‐β (Aβ) accumulation could be a potential therapeutic approach for Alzheimer's disease (AD). Particular functional biomolecules in exosomes vested by the microenvironment in which the original cells resided can be transferred to recipient cells to improve pathological conditions. However, there are few reports addressing whether exosomes derived from cells cultured on scaffolds with varying dimension can reduce Aβ deposition or ameliorate cognitive decline for AD therapy. Herein, both 3D graphene scaffold and 2D graphene film are used as the matrix for human umbilical cord mesenchymal stem cell culture, from which the supernatants are obtained to isolate exosomes. The levels of 195 kinds of miRNAs and proteins, including neprilysin, insulin‐degrading enzyme and heat shock protein 70, in 3D‐cultured exosomes (3D‐Exo) are dramatically different from those obtained from 2D culture. Hence, 3D‐Exo could up‐regulate the expression of α‐secretase and down‐regulate the β‐secretase to reduce Aβ production in both AD pathology cells and transgenic mice, through their special cargo. With rescuing Aβ pathology, 3D‐Exo exerts enhanced therapeutic effects on ameliorating the memory and cognitive deficits in AD mice. These findings provide a novel clinical application for scaffold materials and functional exosomes derived from stem cells.

A Lithium‐Organic Primary Battery

By Pengfei Sun, Panxing Bai, Zifeng Chen, Hai Su, Jixing Yang, Kang Xu, Yunhua Xu from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

A novel lithium‐organic primary battery chemistry is demonstrated by activating the irreversible reaction of anthraquinone cathode by fluoroethylene carbonate, which delivers a high specific capacity of 575 mAh g−1 and density of 1300 Wh kg−1. The mechanism is systematically investigated and revealed to be that the carbonyl groups are electrochemically reduced to methylene accompanied by generation of a large amount of salts. Abstract Lithium primary batteries are still widely used in military, aerospace, medical, and civilian applications despite the omnipresence of rechargeable Li‐ion batteries. However, these current primary chemistries are exclusively based on inorganic materials with high cost, low energy density or severe safety concerns. Here, a novel lithium‐organic primary battery chemistry that operates through a synergetic reduction of 9,10‐anthraquinone (AQ) and fluoroethylene carbonate (FEC) is reported. In FEC‐presence, the equilibrium between the carbonyl and enol structures is disabled, and replaced by an irreversible process that corresponds to a large capacity along with methylene and inorganic salts (such as LiF, Li2CO3) generated as products. This irreversible chemistry of AQ yields a high energy density of 1300 Wh/(kg of AQ) at a stable discharge voltage platform of 2.4 V as well as high rate capability (up to 313 mAh g−1 at a current density of 1000 mA g−1), wide temperature range of operation (−40 to 40 °C) and low self‐discharge rate. Combined with the advantages of low toxicity, facile and diverse synthesis methods, and easy accessibility of AQ, Li‐organic primary battery chemistry promises a new battery candidate for applications that requires low cost, high environmental friendliness, and high energy density.

Rapid and Digital Detection of Inflammatory Biomarkers Enabled by a Novel Portable Nanoplasmonic Imager

By Alexander Belushkin, Filiz Yesilkoy, Juan Jose González‐López, Juan Carlos Ruiz‐Rodríguez, Ricard Ferrer, Anna Fàbrega, Hatice Altug from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

A novel portable optical biosensor based on nanoparticle‐enhanced digital plasmonic imaging is reported to assist sepsis diagnosis, enabling rapid and sensitive detection of blood‐circulating disease biomarkers. The low‐cost device is tested with patient samples in a hospital and is shown to provide performance equivalent to gold‐standard laboratory tests. Abstract New point‐of‐care diagnostic devices are urgently needed for rapid and accurate diagnosis, particularly in the management of life‐threatening infections and sepsis, where immediate treatment is key. Sepsis is a critical condition caused by systemic response to infection, with chances of survival drastically decreasing every hour. A novel portable biosensor based on nanoparticle‐enhanced digital plasmonic imaging is reported for rapid and sensitive detection of two sepsis‐related inflammatory biomarkers, procalcitonin (PCT) and C‐reactive protein (CRP) directly from blood serum. The device achieves outstanding limit of detection of 21.3 pg mL−1 for PCT and 36 pg mL−1 for CRP, and dynamic range of at least three orders of magnitude. The portable device is deployed at Vall d'Hebron University Hospital in Spain and tested with a wide range of patient samples with sepsis, noninfectious systemic inflammatory response syndrome (SIRS), and healthy subjects. The results are validated against ultimate clinical diagnosis and currently used immunoassays, and show that the device provides accurate and robust performance equivalent to gold‐standard laboratory tests. Importantly, the plasmonic imager can enable identification of PCT levels typical of sepsis and SIRS patients in less than 15 min. The compact and low‐cost device is a promising solution for assisting rapid and accurate on‐site sepsis diagnosis.

Reversible Polymorphic Transition and Hysteresis‐Driven Phase Selectivity in Single‐Crystalline C8‐BTBT Rods

By Min‐Woo Kim, Sooncheol Kwon, Jehan Kim, Changhoon Lee, Ina Park, Ji Hoon Shim, Il‐Seok Jeong, Yong‐Ryun Jo, Byoungwook Park, Joo‐Hyung Lee, Kwanghee Lee, Bong‐Joong Kim from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

A polymorph of a single crystalline 2,7‐dioctyl[1] benzothieno[3,2‐b][1]benzothio‐phene rod, synthesized on a low molecular weight poly(methyl methacrylate) exhibits a reversible change in resistivity by 5.5 orders with hysteresis during thermal cycling. Varying cycling temperatures lead to diverse resistivities near room temperature, important for nonvolatile multivalue memories. The polymorph transforms as molecules tilt and thus, only a homogeneous single‐crystalline phase appears at each temperature. Abstract Organic semiconductors (OSCs) are highly susceptible to the formation of metastable polymorphs that are often transformed by external stimuli. However, thermally reversible transformations in OSCs with stability have not been achieved due to weak van der Waals forces, and poor phase homogeneity and crystallinity. Here, a polymorph of a single crystalline 2,7‐dioctyl[1] benzothieno[3,2‐b][1]benzothio‐phene rod on a low molecular weight poly(methyl methacrylate) (≈120k) that limits crystal coarsening during solvent vapor annealing is fabricated. Molecules in the polymorph lie down slightly toward the substrate compared to the equilibrium state, inducing an order of greater resistivity. During thermal cycling, the polymorph exhibits a reversible change in resistivity by 5.5 orders with hysteresis; this transition is stable toward bias and thermal cycling. Remarkably, varying cycling temperatures leads to diverse resistivities near room temperature, important for nonvolatile multivalue memories. These trends persist in the carrier mobility and on/off ratio of the polymorph field‐effect transistor. A combination of in situ grazing incident wide angle X‐ray scattering analyses, visualization for electronic and structural analysis simulations, and density functional theory calculations reveals that molecular tilt governs the charge transport characteristics; the polymorph transforms as molecules tilt, and thereby, only a homogeneous single‐crystalline phase appears at each temperature.

Metal–Semiconductor Phase Twinned Hierarchical MoS2 Nanowires with Expanded Interlayers for Sodium‐Ion Batteries with Ultralong Cycle Life

By Wei Ye, Fangfang Wu, Nianxiang Shi, Han Zhou, Qianqian Chi, Weihua Chen, Shiyu Du, Peng Gao, Haibo Li, Shenglin Xiong from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

The synthesis of metal–semiconductor phase twinned hierarchical MoS2 nanowires with expanded interlayers of 9.63 Å (mixed phase twinned hierarchical MoS2 nanowires) using MoO3 nanobelts as a self‐sacrificed template results in a high reversible capacity, unprecedented cycling life, and excellent rate capability as anode materials for sodium‐ion batteries due to their expanded interlayers, enhanced electronic conductivity, and structure stability. Abstract Sodium‐ion batteries (SIBs) are considered a prospective candidate for large‐scale energy storage due to the merits of abundant sodium resources and low cost. However, a lack of suitable advanced anode materials has hindered further applications. Herein, metal–semiconductor mixed phase twinned hierarchical (MPTH) MoS2 nanowires with an expanded interlayer (9.63 Å) are engineered and prepared using MoO3 nanobelts as a self‐sacrificed template in the presence of a trace amount of (NH4)6Mo7O24·4H2O as initiator. The greatly expanded interlayer spacing accelerates Na+ insertion/extraction kinetics, and the metal–semiconductor mixed phase enhances electron transfer ability and stabilizes electrode structure during cycling. Benefiting from the structural merits, the MPTH MoS2 electrode delivers high reversible capacities of 200 mAh g−1 at 0.1 A g−1 for 200 cycles and 154 mAh g−1 at 1 A g−1 for 2450 cycles in the voltage range of 0.4–3.0 V. Strikingly, the electrode maintains 6500 cycles at a current density of 2 A g−1, corresponding to a capacity retention of 82.8% of the 2nd cycle, overwhelming the all reported MoS2 cycling results. This study provides an alternative strategy to boost SIB cycling performance in terms of reversible capacity by virtue of interlayer expansion and structure stability.

Remote Control of Mechanical Forces via Mitochondrial‐Targeted Magnetic Nanospinners for Efficient Cancer Treatment

By Mengwei Chen, Jiaojiao Wu, Peng Ning, Jingjing Wang, Zuan Ma, Liqun Huang, Gustavo R. Plaza, Yajing Shen, Chang Xu, Yu Han, Maciej S. Lesniak, Zhongmin Liu, Yu Cheng from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

The 20 nm nanocube with mitochondrial‐targeting properties is designed for efficient cancer destruction. Under a rotating magnetic field (RMF) at 15 Hz and 40 mT, it works as a spinner applying the magnetomechanical destruction to the mitochondria of cancer cells. Both in vitro and in vivo studies show that the nanospinners can destroy the cancer cells and inhibit the tumor growth. Abstract In cells, mechanical forces play a key role in impacting cell behaviors, including adhesion, differentiation, migration, and death. Herein, a 20 nm mitochondria‐targeted zinc‐doped iron oxide nanocube is designed as a nanospinner to exert mechanical forces under a rotating magnetic field (RMF) at 15 Hz and 40 mT to fight against cancer. The nanospinners can efficiently target the mitochondria of cancer cells. By means of the RMF, the nanocubes assemble in alignment with the external field and produce a localized mechanical force to impair the cancer cells. Both in vitro and in vivo studies show that the nanospinners can damage the cancer cells and reduce the brain tumor growth rate after the application of the RMF. This nanoplatform provides an effective magnetomechanical approach to treat deep‐seated tumors in a spatiotemporal fashion.

Chiromagnetic Plasmonic Nanoassemblies with Magnetic Field Modulated Chiral Activity

By Xiaoling Wu, Changlong Hao, Liguang Xu, Hua Kuang, Chuanlai Xu from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

Directionally and reversibly switching optical chirality is achieved by magnetic field modulation of Au@Fe3O4 core–satellite nanostructures. The nanostructures exhibit chiral activity in the UV–visible range, and their circular dichroism signal is enhanced 12 times under the magnetic field. This magnetic field‐modulated optical activity may be pivotal for photonic devices, information communication, as well as chiral metamaterials. Abstract Chiral plasmonic nanoassemblies, which exhibit outstanding chiroptical activity in the visible or near‐infrared region, are popular candidates in molecular sensing, polarized nanophotonics, and biomedical applications. Their optical chirality can be modulated by manipulating chemical molecule stimuli or replacing the building blocks. However, instead of irreversible chemical or material changes, real‐time control of optical activity is desired for reversible and noninvasive physical regulating methods, which is a challenging research field. Here, the directionally and reversibly switching optical chirality of magneto‐plasmonic nanoassemblies is demonstrated by the application of an external magnetic field. The gold‐magnetic nanoparticles core–satellite (Au@Fe3O4) nanostructures exhibit chiral activity in the UV–visible range, and the circular dichroism signal is 12 times greater under the magnetic field. Significantly, the chiral signal can be reversed by regulating the direction of the applied magnetic field. The attained magnetic field‐regulated chirality is attributed to the large contributions of the magnetic dipole moments to polarization rotation. This magnetic field‐modulated optical activity may be pivotal for photonic devices, information communication, as well as chiral metamaterials.

Flossing DNA in a Dual Nanopore Device

By Xu Liu, Philip Zimny, Yuning Zhang, Ankit Rana, Roland Nagel, Walter Reisner, William B. Dunbar from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

Active voltage control flosses each DNA bidirectionally to produce multiple electrical scans of a region of the molecule. These scans are then combined to produce averaged intertag distance estimates, which can be used for genome mapping. Abstract Solid‐state nanopores are a single‐molecule technique that can provide access to biomolecular information that is otherwise masked by ensemble averaging. A promising application uses pores and barcoding chemistries to map molecular motifs along single DNA molecules. Despite recent research breakthroughs, however, it remains challenging to overcome molecular noise to fully exploit single‐molecule data. Here, an active control technique termed “flossing” that uses a dual nanopore device is presented to trap a proteintagged DNA molecule and up to 100's of back‐and‐forth electrical scans of the molecule are performed in a few seconds. The protein motifs bound to 48.5 kb λ‐DNA are used as detectable features for active triggering of the bidirectional control. Molecular noise is suppressed by averaging the multiscan data to produce averaged intertag distance estimates that are comparable to their known values. Since nanopore feature‐mapping applications require DNA linearization when passing through the pore, a key advantage of flossing is that trans‐pore linearization is increased to >98% by the second scan, compared to 35% for single nanopore passage of the same set of molecules. In concert with barcoding methods, the dual‐pore flossing technique could enable genome mapping and structural variation applications, or mapping loci of epigenetic relevance.

Atomic‐Scale Fabrication of In‐Plane Heterojunctions of Few‐Layer MoS2 via In Situ Scanning Transmission Electron Microscopy

By Kuo‐Lun Tai, Chun‐Wei Huang, Ren‐Fong Cai, Guan‐Min Huang, Yi‐Tang Tseng, Jun Chen, Wen‐Wei Wu from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

The hybrids of heterojunctions of few‐layer MoS2 are fabricated in terms of diverse layer variation and stacking configuration. The salient dynamics inherent in few‐layer MoS2 are investigated and first observed at the atomic scale, including scrolling, folding, etching, and restructuring. These structures set the stage for further quantum investigation and energy harvesting. Abstract Layered MoS2 is a prospective candidate for use in energy harvesting, valleytronics, and nanoelectronics. Its properties strongly related to its stacking configuration and the number of layers. Due to its atomically thin nature, understanding the atomic‐level and structural modifications of 2D transition metal dichalcogenides is still underdeveloped, particularly the spatial control and selective precision. Therefore, the development of nanofabrication techniques is essential. Here, an atomic‐scale approach used to sculpt 2D few‐layer MoS2 into lateral heterojunctions via in situ scanning/transmission electron microscopy (STEM/TEM) is developed. The dynamic evolution is tracked using ultrafast and high‐resolution filming equipment. The assembly behaviors inherent to few‐layer 2D‐materials are observed during the process and included the following: scrolling, folding, etching, and restructuring. Atomic resolution STEM is employed to identify the layer variation and stacking sequence for this new 2D‐architecture. Subsequent energy‐dispersive X‐ray spectroscopy and electron energy loss spectroscopy analyses are performed to corroborate the elemental distribution. This sculpting technique that is established allows for the formation of sub‐10 nm features, produces diverse nanostructures, and preserves the crystallinity of the material. The lateral heterointerfaces created in this study also pave the way for the design of quantum‐relevant geometries, flexible optoelectronics, and energy storage devices.

Suppressing Cation Migration and Reducing Particle Cracks in a Layered Fe‐Based Cathode for Advanced Sodium‐Ion Batteries

By Jialu Xu, Zhen Han, Kezhu Jiang, Peilai Bai, Yue Liang, Xiaoyu Zhang, Peng Wang, Shaohua Guo, Haoshen Zhou from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

The Ru‐doping sodium electrode retains stable structure during sodium extraction, suppressing Fe‐ion migration and reducing particle cracks via Ru doping. Furthermore, Na4FeRuO6 delivers larger capacity, and better cycling performance compared to NaFeO2, which demonstrates a correlation between the improved electrode performance and the stable structure. Abstract Sodium‐ion batteries have huge potential in large‐scale energy storage applications. Layered Fe‐based oxides are one of the desirable cathode materials due to abundance in the earth crust and high activity in electrochemical processes. However, Fe‐ion migration to Na layers is one of the major hurdles leading to irreversible structural degradation. Herein, it is revealed that distinct Fe‐ion migration in cycling NaFeO2 (NFO) should be mainly responsible for the strong local lattice strain and resulting particle cracks, all of which results in the deterioration of electrochemical performance. More importantly, a strategy of Ru doping could effectively suppress the Fe‐ion migration and then reduce the local lattice strain and the particle cracks, finally to greatly enhance the sodium storage performance. Atomic‐scale characterization shows that NFO electrode after cycling presents the intense lattice strain locally, accompanied by the remarkable particle cracks. Whereas, Ru‐doped NFO electrode maintains the well‐ordered layered structure by inhibiting the Fe–O distortion, so as to eliminate the resulting side effect. As a result, Ru‐doped NFO could greatly improve the comprehensive electrochemical performance by delivering a reversible capacity of 120 mA h g−1, about 80% capacity retention after 100 cycles. The findings provide new insights for designing high‐performance electrodes for sodium‐ion batteries.

Biodegradable Nanocarriers Resembling Extracellular Vesicles Deliver Genetic Material with the Highest Efficiency to Various Cell Types

By Yana Tarakanchikova, Jamal Alzubi, Valentina Pennucci, Marie Follo, Boris Kochergin, Albert Muslimov, Ilya Skovorodkin, Seppo Vainio, Maria N. Antipina, Vsevolod Atkin, Alexey Popov, Igor Meglinski, Toni Cathomen, Tatjana I. Cornu, Dmitry A. Gorin, Gleb B. Sukhorukov, Irina Nazarenko from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

This work demonstrates a new tool for the transfer of genetic material. The developed biodegradable polyelectrolyte nanocapsules exhibit high levels of uptake and transfer to various cell types, including hematopoietic stem cells. A co‐transfer and regulated release of several types of RNAs or DNAs are possible using this approach, and are able to revolutionize gene transfer technology. Abstract Efficient delivery of genetic material to primary cells remains challenging. Here, efficient transfer of genetic material is presented using synthetic biodegradable nanocarriers, resembling extracellular vesicles in their biomechanical properties. This is based on two main technological achievements: generation of soft biodegradable polyelectrolyte capsules in nanosize and efficient application of the nanocapsules for co‐transfer of different RNAs to tumor cell lines and primary cells, including hematopoietic progenitor cells and primary T cells. Near to 100% efficiency is reached using only 2.5 × 10−4 pmol of siRNA, and 1 × 10−3 nmol of mRNA per cell, which is several magnitude orders below the amounts reported for any of methods published so far. The data show that biodegradable nanocapsules represent a universal and highly efficient biomimetic platform for the transfer of genetic material with the utmost potential to revolutionize gene transfer technology in vitro and in vivo.

Controlling Nanoscale Thermal Expansion of Monolayer Transition Metal Dichalcogenides by Alloy Engineering

By Xuan Hu, Zahra Hemmat, Leily Majidi, John Cavin, Rohan Mishra, Amin Salehi‐Khojin, Serdar Ogut, Robert F. Klie from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

Alloy engineering is used to control the thermal expansion (TEC) of 2D transition metal dichalcogenides, such as Mo1−xWxS2. In‐situ heating experiments in a scanning transmission electron microscope are combined with electron energy‐loss spectroscopy to determine the temperature‐dependent bulk plasmon peak shift. Combined with first‐principles modeling, the TEC is directly determined, showing a strong dependence on the chemical composition in Mo1−xWxS2. Abstract 2D materials, such as transition metal dichalcogenides (TMDs), graphene, and boron nitride, are seen as promising materials for future high power/high frequency electronics. However, the large difference in the thermal expansion coefficient (TEC) between many of these 2D materials could impose a serious challenge for the design of monolayer‐material‐based nanodevices. To address this challenge, alloy engineering of TMDs is used to tailor their TECs. Here, in situ heating experiments in a scanning transmission electron microscope are combined with electron energy‐loss spectroscopy and first‐principles modeling of monolayer Mo1−xWxS2 with different alloying concentrations to determine the TEC. Significant changes in the TEC are seen as a function of chemical composition in Mo1−xWxS2, with the smallest TEC being reported for a configuration with the highest entropy. This study provides key insights into understanding the nanoscale phenomena that control TEC values of 2D materials.

0D Cs3Cu2X5 (X = I, Br, and Cl) Nanocrystals: Colloidal Syntheses and Optical Properties

By Zhishan Luo, Qian Li, Liming Zhang, Xiaotong Wu, Li Tan, Chao Zou, Yejing Liu, Zewei Quan from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

0D all‐inorganic Cs3Cu2X5 (X = I, Br, and Cl) nanocrystals (NCs) with orthorhombic structure and well‐defined morphologies are produced. The NCs exhibit a continuous redshift of broadband blue‐green photoluminescence emissions in the range of 445–527 nm as X is changed from I to Br and Cl, which are attributed to their intrinsic self‐trapped exciton emission characteristics. Abstract 0D lead‐free metal halide nanocrystals (NCs) are an emerging class of materials with intriguing optical properties. Herein, colloidal synthetic routes are presented for the production of 0D Cs3Cu2X5 (X = I, Br, and Cl) NCs with orthorhombic structure and well‐defined morphologies. All these Cs3Cu2X5 NCs exhibit broadband blue‐green photoluminescence (PL) emissions in the range of 445–527 nm with large Stokes shifts, which are attributed to their intrinsic self‐trapped exciton (STE) emission characteristics. The high PL quantum yield of 48.7% is obtained from Cs3Cu2Cl5 NCs, while Cs3Cu2I5 NCs exhibit considerable air stability over 45 days. Intriguingly, as X is changed from I to Br and Cl, Cs3Cu2X5 NCs exhibit a continuous redshift of emission peaks, which is contrary to the blueshift in CsPbX3 perovskite NCs.

Selective Liquid Sliding Surfaces with Springtail‐Inspired Concave Mushroom‐Like Micropillar Arrays

By Seong Min Kang, Ji Seong Choi from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

A selective liquid sliding surface is presented by utilizing the concave mushroom tip shape, inspired from the cuticular structure of springtail. The reentrant concave tip arrays present two remarkable properties: i) “omniphobicity” with deionized water (γw = 72.1 mN m−1) and mineral oil (γo = 28 mN m−1), and ii) “selective liquid sliding” where the roll‐off angle of oil is lower than water. Abstract Herein, a mushroom‐like reentrant structure is proposed, inspired by springtails, to create a selective liquid sliding surface by implementing a simple yet sturdy silicon fabrication and lithography method. The fabricated arrays display high structural fidelity, presenting a novel geometry of a concave tip. The mushroom‐like head shape of these structures is found to have superomniphobicity, which is independent of a variation of temperatures for even low surface tension liquids such as mineral oil. A design rule for the novel cap of the proposed structures, which results in a selective liquid sliding property with deionized (DI) water and mineral oil, is also investigated. It is demonstrated that oil starts to slide at a roll‐off angle (ROA) 10° and then DI water rolls off at ROA 15° on the same fabricated transparent and flexible surface with repeatable durability.

2D Antimony–Arsenic Alloys

By Matthieu Fortin‐Deschênes, Olga Waller, Qi An, Maureen J. Lagos, Gianluigi A. Botton, Hong Guo, Oussama Moutanabbir from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

This work shows the first experimental demonstration of the growth of 2D arsenic–antimony alloys. The growth is achieved by solid‐source molecular beam epitaxy. This novel family of group V 2D alloys presents a rich playground to achieve highly tunable properties for integration in scalable nanoscale and quantum technologies. Abstract Alloying in group V 2D materials and heterostructures is an effective degree of freedom to tailor and enhance their physical properties. Up to date, black arsenic‐phosphorus is the only 2D group V alloy that has been experimentally achieved by exfoliation, leaving all other possible alloys in the realm of theoretical predictions. Herein, the existence of an additional alloy consisting of 2D antimony arsenide (2D‐AsxSb1−x) grown by molecular beam epitaxy on group IV semiconductor substrates and graphene is demonstrated. The atomic mixing of As and Sb in the lattice of the grown 2D layers is confirmed by low‐energy electron diffraction, Raman spectroscopy, and X‐ray photoelectron spectroscopy. The As content in 2D‐AsxSb1−x is shown to depend linearly on the As4/Sb4 deposition rate ratio and As concentrations up to 15 at% are reached. The grown 2D alloys are found to be stable in ambient conditions in a timescale of weeks but to oxidize after longer exposure to air. This study lays the groundwork for a better control of the growth and alloying of group V 2D materials, which is critical to study their basic physical properties and integrate them in novel applications.

Controlling Photoluminescence Enhancement and Energy Transfer in WS2:hBN:WS2 Vertical Stacks by Precise Interlayer Distances

By Wenshuo Xu, Daichi Kozawa, Yingqiu Zhou, Yizhi Wang, Yuewen Sheng, Tian Jiang, Michael S. Strano, Jamie H. Warner from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

Vertical heterostructures of WS2:hBN:WS2 exhibit photoluminescence enhancement due to interlayer energy transfer, derived from differences in the doping levels. The interlayer interactions are tuned by accurately controlling the thickness of the hBN barrier between the two WS2 vertical stacked layers, along with the strain in WS2 and temperature. Abstract 2D semiconducting transition metal dichalcogenides (TMDs) are endowed with fascinating optical properties especially in their monolayer limit. Insulating hBN films possessing customizable thickness can act as a separation barrier to dictate the interactions between TMDs. In this work, vertical layered heterostructures (VLHs) of WS2:hBN:WS2 are fabricated utilizing chemical vapor deposition (CVD)‐grown materials, and the optical performance is evaluated through photoluminescence (PL) spectroscopy. Apart from the prohibited indirect optical transition due to the insertion of hBN spacers, the variation in the doping level of WS2 drives energy transfer to arise from the layer with lower quantum efficiency to the other layer with higher quantum efficiency, whereby the total PL yield of the heterosystem is increased and the stack exhibits a higher PL intensity compared to the sum of those in the two WS2 constituents. Such doping effects originate from the interfaces that WS2 monolayers reside on and interact with. The electron density in the WS2 is also controlled and subsequent modulation of PL in the heterostructure is demonstrated by applying back‐gated voltages. Other influential factors include the strain in WS2 and temperature. Being able to tune the energy transfer in the VLHs may expand the development of photonic applications in 2D systems.

Microsphere‐Like SiO2/MXene Hybrid Material Enabling High Performance Anode for Lithium Ion Batteries

By Ge Mu, Daobin Mu, Borong Wu, Chengwei Ma, Jiaying Bi, Ling Zhang, Hao Yang, Feng Wu from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

Microsphere‐like SiO2/MXene hybrid material is designed and successfully synthesized through the combination of the Stöber method and spray drying. The bonding effect between SiO2 nanoparticles and MXene matrix boosts the structural stability of entire microspheres. The SiO2/MXene anode enables high initial coulombic efficiency, high reversible capacity, superior cycling stability, and high areal capacity at high mass loading. Abstract To address the non‐negligible volume expansion and the inherent poor electronic conductivity of silica (SiO2) material, microsphere‐like SiO2/MXene hybrid material is designed and successfully synthesized through the combination of the Stöber method and spray drying. The SiO2 nanoparticles are firmly anchored on the laminated MXene by the bonding effect, which boosts the structural stability during the long‐term cycling process. The MXene matrix not only possesses high elasticity to buffer the volume variation of SiO2 nanoparticles, but also promotes the transfer of electrons and lithium ions. Moreover, the microsphere wrapped with ductile MXene film reduces the specific surface area, relieves the side reactions, and enhances the coulombic efficiency. Therefore, superior electrochemical performance including high reversible capacity, outstanding cycle stability, high coulombic efficiency, especially in the first cycle, excellent rate capability as well as high areal capacity are acquired for SiO2/MXene microspheres anode.

Masthead: (Small 3/2020)

By from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

Optical Biosensors: Rapid and Digital Detection of Inflammatory Biomarkers Enabled by a Novel Portable Nanoplasmonic Imager (Small 3/2020)

By Alexander Belushkin, Filiz Yesilkoy, Juan Jose González‐López, Juan Carlos Ruiz‐Rodríguez, Ricard Ferrer, Anna Fàbrega, Hatice Altug from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

In article number 1906108, Anna Fàbrega, Hatice Altug, and co‐workers present a portable optical biosensor based on nanoparticle‐enhanced digital plasmonic imaging to assist sepsis diagnosis, enabling rapid and sensitive detection of blood‐circulating disease biomarkers. The low‐cost device is tested with patient samples in a hospital and is shown to provide performance equivalent to gold‐standard laboratory tests.

Few‐Layer MoS2: Atomic‐Scale Fabrication of In‐Plane Heterojunctions of Few‐Layer MoS2 via In Situ Scanning Transmission Electron Microscopy (Small 3/2020)

By Kuo‐Lun Tai, Chun‐Wei Huang, Ren‐Fong Cai, Guan‐Min Huang, Yi‐Tang Tseng, Jun Chen, Wen‐Wei Wu from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

In article number 1905516, Wen‐Wei Wu and co‐workers fabricate the hybrids of heterojunctions of few‐layer MoS2 in terms of diverse layer variation and stacking configuration, through in‐situ scanning/transmission electron microscopy heating. The salient dynamics inherent in few‐layer MoS2 are investigated and first observed at the atomic scale, including scrolling, folding, etching, and restructuring. These structures set the stage for further quantum investigation and energy harvesting.

Organic Semiconductors: Reversible Polymorphic Transition and Hysteresis‐Driven Phase Selectivity in Single‐Crystalline C8‐BTBT Rods (Small 3/2020)

By Min‐Woo Kim, Sooncheol Kwon, Jehan Kim, Changhoon Lee, Ina Park, Ji Hoon Shim, Il‐Seok Jeong, Yong‐Ryun Jo, Byoungwook Park, Joo‐Hyung Lee, Kwanghee Lee, Bong‐Joong Kim from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

In article number 1906109, Kwanghee Lee, Bong‐Joong Kim, and co‐workers synthesize a polymorph of a single crystalline 2,7‐dioctyl[1] benzothieno[3,2‐b][1]benzothio‐phene (C8‐BTBT) rod on a low molecular weight poly(methyl methacrylate) (PMMA), which exhibits a reversible change in resistivity by 5.5 orders with hysteresis during thermal cycling. Varying cycling temperatures leads to diverse resistivities near room temperature, important for non‐volatile multivalue memories. The polymorph transforms as molecules tilt, thus only a homogeneous single‐crystalline phase appears at each temperature.

Alloy Engineering: Controlling Nanoscale Thermal Expansion of Monolayer Transition Metal Dichalcogenides by Alloy Engineering (Small 3/2020)

By Xuan Hu, Zahra Hemmat, Leily Majidi, John Cavin, Rohan Mishra, Amin Salehi‐Khojin, Serdar Ogut, Robert F. Klie from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

In article number 1905892, Robert F. Klie and co‐workers show that alloy engineering can be used to control the thermal expansion (TEC) of 2D materials, including the transition metal dichalcogenide Mo1−xWxS2. Using a combination of atomic‐resolution scanning transmission electron microscopy imaging and electron spectroscopy at elevated temperature with first‐principles modeling, the dependence of the TEC on the chemical composition of Mo1−xWxS2 is demonstrated. Image credit: John Cavin, Washington University in St. Louis.

New Advances in In Vivo Applications of Gated Mesoporous Silica as Drug Delivery Nanocarriers

By Alba García‐Fernández, Elena Aznar, Ramón Martínez‐Máñez, Félix Sancenón from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

A comprehensive overview of mesoporous‐silica‐based gated materials used for drug delivery applications in in vivo models, published from 2016 to date, is presented. The discussed examples are divided by taking into account the stimuli used to trigger payload release from the gated materials (pH changes, redox reactions, enzymes, light, temperature, magnetic fields, ultrasounds, and small molecules). Abstract One appealing concept in the field of hybrid materials is related to the design of gated materials. These materials are prepared in such a way that the release of chemical or biochemical species from voids of porous supports to a solution is triggered upon the application of external stimuli. Such gated materials are mainly composed of two subunits: i) a porous inorganic scaffold in which a cargo is stored, and ii) certain molecular or supramolecular entities, grafted onto the external surface, that can control mass transport from the interior of the pores. On the basis of this concept, a large number of examples are developed in the past ten years. A comprehensive overview of gated materials used in drug delivery applications in in vivo models from 2016 to date is thus given here.

Thu 13 Feb 16:00: Gravitational wave probes of new physics

From All Talks (aka the CURE list). Published on Jan 23, 2020.

Gravitational wave probes of new physics

I will give an overview on gravitational waves from phase transitions, and then focus on specific hidden sector scenarios such as dark photons or axions, and discuss how they could be probed by future gravitational wave observations in pulsar timing arrays, space and ground based detectors.

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Thu 30 Jan 14:00: The genome landscape: consequences of repetitive DNA organization and evolution in diploid and polyploid crops Host: Anne Ferguson-Smith

From All Talks (aka the CURE list). Published on Jan 23, 2020.

The genome landscape: consequences of repetitive DNA organization and evolution in diploid and polyploid crops

As in other species, repetitive DNA makes up the majority of the plant genome, including shorter and longer tandem repeats, DNA transposons and retrotransposons. These are often the most rapidly evolving component of the genome, but many aspects of their evolution are difficult to study because of the high copy numbers and degeneracy. Rapid evolution means the elements can provide useful markers for evolution, particularly in species that are polyploid containing several related genomes. Other elements are related to pararetroviruses, and may have a role in plant virus protection. The functions of repeats may range from epigenetic through genetic, and I will discuss these in relation to evolutionary constraints – “Nothing in Biology Makes Sense Except in the Light of Evolution” as stated by Theodosius Dobzhansky, and “The history of all organisms is inscribed in the chromosomes” as noted by Hitoshi Kihara. We can develop models of drivers and mechanisms. New work I will discuss is exploiting long, single-molecule DNA sequencing (Nanopore), for the first time, to give insight into the organization of arrays of tandem repeats, their interspersion with retroelements, and other rearrangements. Preliminary results show insertion of particular retroelements into tandem arrays of 8.5kb 45S rDNA units, although we have concerns about sequencing artefacts in some situations. Our somewhat out-of-date website www.molcyt.com gives some details of our programme.

Host: Anne Ferguson-Smith

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Electromagnetic Shielding of Monolayer MXene Assemblies

By Taeyeong Yun, Hyerim Kim, Aamir Iqbal, Yong Soo Cho, Gang San Lee, Myung‐Ki Kim, Seon Joon Kim, Daesin Kim, Yury Gogotsi, Sang Ouk Kim, Chong Min Koo from Wiley: Advanced Materials: Table of Contents. Published on Jan 23, 2020.

Self‐assembly of monolayer MXene and systematic exploration of electromagnetic interference shielding behavior of 2D Ti3C2Tx MXene are presented. Theoretical models explain the shielding mechanism below skin depth. A monolayer assembled MXene film (2.3 nm) and 24‐layer film (≈55 nm) offer ≈20% and 99% shielding, respectively. The extraordinarily large absolute shielding effectiveness reached 3.89 × 106 dB cm2 g−1. Abstract Miniaturization of electronics demands electromagnetic interference (EMI) shielding of nanoscale dimension. The authors report a systematic exploration of EMI shielding behavior of 2D Ti3C2Tx MXene assembled films over a broad range of film thicknesses, monolayer by monolayer. Theoretical models are used to explain the shielding mechanism below skin depth, where multiple reflection becomes significant, along with the surface reflection and bulk absorption of electromagnetic radiation. While a monolayer assembled film offers ≈20% shielding of electromagnetic waves, a 24‐layer film of ≈55 nm thickness demonstrates 99% shielding (20 dB), revealing an extraordinarily large absolute shielding effectiveness (3.89 × 106 dB cm2 g−1). This remarkable performance of nanometer‐thin solution processable MXene proposes a paradigm shift in shielding of lightweight, portable, and compact next‐generation electronic devices.

Versatile Macroscale Concentration Gradients of Nanoparticles in Soft Nanocomposites

By Patricia Taladriz‐Blanco, Barbara Rothen‐Rutishauser, Alke Petri‐Fink, Sandor Balog from Wiley: Small: Table of Contents. Published on Jan 23, 2020.

Nanoparticle gradient materials encounter Taylor dispersion. The synergism of two physical phenomena—translational self‐diffusion and shear‐driven dispersion in laminar flow—gives access to an exceptionally high degree of flexibility in the design and creation of scalable and programmable long‐range concentration gradients of nanoparticles in solidifiable liquid matrices. Abstract Nanocomposite materials benefit from the diverse physicochemical properties featured by nanoparticles, and the presence of nanoparticle concentration gradients can lend functions to macroscopic materials beyond the realm of classical nanocomposites. It is shown here that linearity and time‐shift invariance obtained via the synergism of two independent physical phenomena—translational self‐diffusion and shear‐driven dispersion—may give access to an exceptionally high degree of flexibility in the design of scalable and programmable long‐range concentration gradients of nanoparticles in solidifiable liquid matrices.

Wed 19 Feb 14:15: The KKP conjecture for minimal adjoint orbits

From All Talks (aka the CURE list). Published on Jan 23, 2020.

The KKP conjecture for minimal adjoint orbits

I will explain a construction of symplectic Lefschetz fibrations on adjoint orbits, give examples and an application to mirror symmetry. I will then show that our construction produces a family of examples satisfying the Kontsevich-Katzarkov-Pantev conjecture (this is joint work with Ballico, San Martin, and Rubilar).

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Fri 06 Mar 14:00: Optical superresolution microscopy of molecular mechanisms of disease

From All Talks (aka the CURE list). Published on Jan 23, 2020.

Optical superresolution microscopy of molecular mechanisms of disease

Key Words: nanoscopy, live cell imaging, neurodegeneration, protein self-assembly reactions

The self-assembly of proteins into ordered macromolecular structures is fundamental to a variety of diseases, for example in neurodegeneration, where misfolded proteins aggregate into toxic fibrillar shapes, or during virus replication, where the assembly of functional virions in the host cell is a tightly organized process. In this talk, I will give an overview of optical imaging techniques (1-3) that allow us to gain insights into protein self-assembly reactions in vitro (4 – 7), in cells (8 – 10), and in live model organisms of disease (11). In particular, we wish to understand how proteins nucleate to form functional or toxic structures and to correlate such information with biological phenotypes. I will show how single molecule localization microscopy, and developments in high speed structured illumination microscopy are capable of tracking the aggregation of proteins in vitro and in vivo, and how such data are interpreted in the context of disease (11-17).

References: (1) F. Stroehl and C.F. Kaminski, Optica (2016) (2) M. Fantham and C.F. Kaminski, Nat. Phot. (2016) (3) F. Stroehl et al., Sci. Rep. (2016) (4) G.S. Kaminski Schierle, et al, JACS (2011) (5) D. Pinotsi et al, Nano Letters (2013) (6) R. Laine et al, Nat. Comms (2018) (7) R. Laine et al, eLife (2018) (8) E. Avezov et al., Nat. Cell Biol.(2018) (9) D. Pinotsi et al, PNAS (2016) (10) M. Lu et al, JBC (2019) (11) G.S. Kaminski Schierle et al, ChemPhysChem (2011) (12) C. Michel, et al, JBC (2014) (13) T. Murakami, et al, Neuron (2015) (14) H. Wong, et al, Neuron (2017) (15) G. Fusco, et al, Nat. Comms. (2016) (16) S. Qamar, et al, Cell (2018) (17) J. Lautenschlaeger et al., Nat. Comms. (2018)

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[ASAP] The Strongest Size in Gradient Nanograined Metals

By Penghui Cao*†‡ from Nano Letters: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Nano Letters
DOI: 10.1021/acs.nanolett.9b05202

[ASAP] Borophene Concentric Superlattices via Self-Assembly of Twin Boundaries

By Liren Liu†, Zhuhua Zhang*†, Xiaolong Liu‡, Xiaoyu Xuan†, Boris I. Yakobson§, Mark C. Hersam*‡??, and Wanlin Guo*† from Nano Letters: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Nano Letters
DOI: 10.1021/acs.nanolett.9b04798

[ASAP] Direct Observation of the Linear Dichroism Transition in Two-Dimensional Palladium Diselenide

By Juan Yu‡†°, Xiaofei Kuang†°, Yuanji Gao‡, Yunpeng Wang‡, Keqiu Chen§, Zhongke Ding§, Jia Liu?, Chunxiao Cong?, Jun He*‡, Zongwen Liu*#, and Yanping Liu*‡?• from Nano Letters: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Nano Letters
DOI: 10.1021/acs.nanolett.9b04598

[ASAP] Radio-Frequency-Detected Fast Charge Sensing in Undoped Silicon Quantum Dots

By Akito Noiri*†‡, Kenta Takeda†‡, Jun Yoneda†#, Takashi Nakajima†, Tetsuo Kodera¶, and Seigo Tarucha*† from Nano Letters: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Nano Letters
DOI: 10.1021/acs.nanolett.9b03847

[ASAP] Low-Power Switching through Disorder and Carrier Localization in Bismuth-Doped Germanium Telluride Phase Change Memory Nanowires

By Gaurav Modi, Eric A. Stach, and Ritesh Agarwal* from ACS Nano: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b08986

[ASAP] Interlayer Decoupling in 30° Twisted Bilayer Graphene Quasicrystal

By Bing Deng†¶, Binbin Wang‡¶, Ning Li§?¶, Rongtan Li?, Yani Wang†, Jilin Tang†#, Qiang Fu?, Zhen Tian‡, Peng Gao*§?, Jiamin Xue*‡, and Hailin Peng*† from ACS Nano: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b07091

[ASAP] Learning from Artemisinin: Bioinspired Design of a Reaction-Based Fluorescent Probe for the Selective Sensing of Labile Heme in Complex Biosystems

By Shuai Xu†, Hong-Wen Liu†, Lanlan Chen‡, Jie Yuan†, Yongchao Liu†, Lili Teng†, Shuang-Yan Huan†, Lin Yuan†, Xiao-Bing Zhang*†, and Weihong Tan† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11245

[ASAP] Capture and Release of Singlet Oxygen in Coordination-Driven Self-Assembled Organoplatinum(II) Metallacycles

By Yan-Qin He†‡#, Werner Fudickar§#, Jian-Hong Tang*‡, Heng Wang?, Xiaopeng Li?, Jun Han†, Zhengping Wang†, Min Liu†, Yu-Wu Zhong?, Torsten Linker*§, and Peter J. Stang*‡ from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12693

[ASAP] Frustrated Lewis-Pair-Meditated Selective Single Fluoride Substitution in Trifluoromethyl Groups

By Dipendu Mandal†, Richa Gupta†, Amit K. Jaiswal, and Rowan D. Young* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12167

[ASAP] Optical Control of Small Molecule-Induced Protein Degradation

By Yuta Naro‡, Kristie Darrah‡, and Alexander Deiters* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12718

[ASAP] Capture of the Sulfur Monoxide–Hydroxyl Radical Complex

By Changyun Chen†?, Bo Lu†?, Xiaofang Zhao†, Weiyu Qian†, Jie Liu†, Tarek Trabelsi‡, Joseph S. Francisco*‡, Jie Qin§, Jun Li*§, Lina Wang#, and Xiaoqing Zeng*†# from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12152

[ASAP] Self-Assembly, Structural Transformation, and Guest-Binding Properties of Supramolecular Assemblies with Triangular Metal–Metal Bonded Units

By Li-Juan Wang†, Xin Li†, Sha Bai, Yao-Yu Wang, and Ying-Feng Han* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12309

[ASAP] Manipulating On/Off Single-Molecule Magnet Behavior in a Dy(III)-Based Photochromic Complex

By Yu-Juan Ma‡†, Ji-Xiang Hu‡†, Song-De Han†, Jie Pan†, Jin-Hua Li†, and Guo-Ming Wang*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b13461

[ASAP] Mechanism of Molecular Oxygen Diffusion in a Hypoxia-Sensing Prolyl Hydroxylase Using Multiscale Simulation

By Carmen Domene*†‡§, Christian Jorgensen‡, and Christopher J. Schofield*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b09236

[ASAP] Fast Li+ Conduction Mechanism and Interfacial Chemistry of a NASICON/Polymer Composite Electrolyte

By Nan Wu†‡?, Po-Hsiu Chien§??, Yutao Li*†, Andrei Dolocan†, Henghui Xu†, Biyi Xu†, Nicholas S. Grundish†, Haibo Jin‡, Yan-Yan Hu§?, and John B. Goodenough*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12233

[ASAP] N-Heterocyclic Carbenes as Reversible Exciton-Delocalizing Ligands for Photoluminescent Quantum Dots

By Dana E. Westmoreland, Rafael Lo´pez-Arteaga, and Emily A. Weiss* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b13605

[ASAP] Structure-Guided Improvement of a Dual HPIV3/RSV Fusion Inhibitor

By Victor K. Outlaw†, Jennifer T. Lemke†, Yun Zhu‡§, Samuel H. Gellman*†, Matteo Porotto*‡??, and Anne Moscona*‡?#? from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 23, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11548

How Metallic are Noble-Metal Clusters? Static Screening and Polarizability in Quantum-Sized Silver and Gold Nanoparticles

By Hans-Christian Weissker from RSC - Nanoscale latest articles. Published on Jan 23, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR08608K, Paper
Rajarshi Sinha-Roy, Pablo García-González, Hans-Christian Weissker
Metallicity of nanoparticles can be defined in different ways. One possibility is to look at the degree to which external fields are screened inside the object. This screening would be...
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PLGA protein nanocarrier with made-to-order fluorescence/MRI/PET imaging modalities

By Anna Roig from RSC - Nanoscale latest articles. Published on Jan 23, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR10620K, Paper
Open Access Open Access
Yajie Zhang, Miguel García-Gabilondo, Alba Grayston, Irene Veronika Judith Feiner, Irene Anton-Sales, Rodrigo A. Loiola, Jordi Llop, Pedro Ramos-Cabrer, Ignasi Barba, David Garcia-Dorado, Fabien Gosselet, Anna Rosell, Anna Roig
Developing multifunctional and biocompatible drug delivery nanoplatforms that integrate high drug loading capacity together with multiple imaging modalities while at the same time avoiding cross interferences is extremely challenging. Here,...
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Direct identification of the herpes simplex virus UL27 gene through single particle manipulation and optical detection using a micromagnetic array

By Gil U. Lee from RSC - Nanoscale latest articles. Published on Jan 23, 2020.

Nanoscale, 2020, Advance Article
DOI: 10.1039/C9NR10362G, Paper
Peng Li, Dhruv Gandhi, Marina Mutas, Yin-Fen Ran, Michael Carr, Stefano Rampini, William Hall, Gil U. Lee
The UL27 gene of Human simplex virus-1 has been identified through hybridization to superparamagnetic particles and identification on a microfabricated magnet array with integrated optical detector.
To cite this article before page numbers are assigned, use the DOI form of citation above.
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Nanoparticle translocation across the lung surfactant film regulated by grafting polymers

By Guoqing Hu from RSC - Nanoscale latest articles. Published on Jan 23, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR09251J, Paper
Xuan Bai, Mujun Li, Guoqing Hu
Nanoparticle-based pulmonary drug delivery has gained significant attention due to its ease of administration, increased bioavailability, and reduced side effects caused by high systemic dosage. Being delivered into the deep...
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Wideband saturable absorption in Metal-organic frameworks (MOFs) for mode-locking Er- and Tm-doped fiber laser

By Zheng Zheng from RSC - Nanoscale latest articles. Published on Jan 23, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR09330C, Paper
Qian Zhang, Xiantao Jiang, Meng Zhang, Xinxin Jin, Han Zhang, Zheng Zheng
We fabricate a Metal-organic frameworks (MOFs) Saturable absorber (SA) based on a microfiber. Nonlinear optical absorption of the MOFs SA is characterized systmatically. The modulation depth is measured to be...
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Encapsulation of MnFe2O4 Nanoparticles into Carbon Framework with Superior Rate Capability for Lithium Ion Battery

By Yafei Liu from RSC - Nanoscale latest articles. Published on Jan 23, 2020.

Nanoscale, 2020, Accepted Manuscript
DOI: 10.1039/C9NR10002D, Paper
Yijing Wang, Weiqin Li, Cuihua An, Huinan Guo, Yan Zhang, Kai Chen, Zeting Zhang, Guishu Liu, Yafei Liu
Binary transition metal oxides (BTMOs) have been regarded as one of the most hopeful anode materials for lithium ion batteries (LIBs), owing to their high theoretical capacity, excellent electrochemical activity...
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Tue 28 Jan 14:30: Distribution of Hecke eigenvalues

From All Talks (aka the CURE list). Published on Jan 22, 2020.

Distribution of Hecke eigenvalues

There are many difficult conjectures about automorphic representations, many of which seem to be out of reach at the moment. It has therefore become increasingly popular to study instead families of automorphic representations and their statistical properties, which allows for additional analytic techniques to be used.

In my talk I want to discuss the distribution of Hecke eigenvalues or, in other words, Satake parameters in the family of spherical unramified automorphic representations of split classical groups. We obtain an effective distribution of the Satake parameters, when we order the family according to the size of analytic conductor. This has applications to various questions in number theory, for example, low-lying zeros in families of automorphic L-functions, but also yields an effective Weyl law for the underlying locally symmetric space. This is joint work with T. Finis.

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Advanced Se3P4@C Anode with Exceptional Cycling Life for High Performance Potassium‐Ion Batteries

By Bing Li, Ziyao He, Jiawei Zhao, Wentao Liu, Yangyang Feng, Jiangxuan Song from Wiley: Small: Table of Contents. Published on Jan 22, 2020.

A Se3P4@C anode with high capacity and exceptional cycling life is developed for potassium‐ion batteries. The synergistic effect between Se and P atom as well as the carbon host in the composite is clarified for playing a critical role in the excellent electrochemical performance. Abstract Potassium‐ion batteries have attracted increasing attention for next‐generation energy storage systems due to their high energy density and abundance of potassium. However, the lack of suitable anode highly hampers its practical application due to the large ionic radius of K+. Herein, a Se3P4@mesoporous carbon (Se3P4@C) composite is reported as a high‐performance anode for potassium‐ion batteries. The Se3P4@C composite is synthesized through an in situ combination reaction between red phosphorus and Se within a porous carbon matrix. In this way, the nano‐sized Se3P4 is well confined in the porous carbon and thus exhibits a close contact with the carbon matrix. This can significantly improve the conductivity and alleviate the volume change during the cycling process. As a result, the Se3P4@C exhibits a high reversible initial capacity of 1036.8 mAh g−1 at a current density of 50 mA g−1 as well as an excellent cycle performance with a capacity decay of 0.07% per cycle over 300 cycles under 1000 mA g−1. In terms of high specific capacity and stable cycling performance, the Se3P4@C anode is a promising candidate for advanced potassium‐ion batteries.

Iridium‐Catalyzed Silylation of Five‐Membered Heteroarenes: High Sterically Derived Selectivity from a Pyridyl‐Imidazoline Ligand

By Caleb Karmel, Camille Z. Rubel, Elena V. Kharitonova, John F. Hartwig from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

The steric effects of substituents on five‐membered rings are less pronounced than those on six‐membered rings because of the difference in bond angles. Thus, the regioselectivities of reactions that occur with selectivities dictated by steric effects, such as the borylation of C‐H bonds, have been poor in many cases. We report that the silylation of five‐membered ring heteroarenes occurs with high sterically derived regioselectivity when catalyzed by the combination of [Ir(cod)(OMe)] 2 and a phenanthroline ligand or a new pyridyl‐imidazoline ligand that further increases the regioselectivity. The silylation reactions with these catalysts produce high yields of heteroarylsilanes from functionalization at the most sterically accessible C–H bonds of these rings under conditions that the borylation of C–H bonds with previously reported catalysts formed mixtures of products or products that are unstable. The heteroarylsilane products undergo cross‐coupling reactions and substitution reactions with ipso selectivity to generate heteroarenes that bear halogen, aryl and perfluoroalkyl substituents.

Unexpected Giant Microwave Conductivity in a Nominally Silent BiFeO3 Domain Wall

By Yen‐Lin Huang, Lu Zheng, Peng Chen, Xiaoxing Cheng, Shang‐Lin Hsu, Tiannan Yang, Xiaoyu Wu, Louis Ponet, Ramamoorthy Ramesh, Long‐Qing Chen, Sergey Artyukhin, Ying‐Hao Chu, Keji Lai from Wiley: Advanced Materials: Table of Contents. Published on Jan 22, 2020.

The microwave conductivity of ferroelectric domain walls is crucial for their applications in high‐speed electronics. Herein, a giant gigahertz conductivity is observed in certain BiFeO3 domain walls, whose nominal configuration preludes alternating current (ac) conduction. This unexpected phenomenon is explained by the imbalanced polarization across the wall, which couples to the microwave field and induces power dissipation. Abstract Nanoelectronic devices based on ferroelectric domain walls (DWs), such as memories, transistors, and rectifiers, have been demonstrated in recent years. Practical high‐speed electronics, on the other hand, usually demand operation frequencies in the gigahertz (GHz) regime, where the effect of dipolar oscillation is important. Herein, an unexpected giant GHz conductivity on the order of 103 S m−1 is observed in certain BiFeO3 DWs, which is about 100 000 times greater than the carrier‐induced direct current (dc) conductivity of the same walls. Surprisingly, the nominal configuration of the DWs precludes the alternating current (ac) conduction under an excitation electric field perpendicular to the surface. Theoretical analysis shows that the inclined DWs are stressed asymmetrically near the film surface, whereas the vertical walls in a control sample are not. The resultant imbalanced polarization profile can then couple to the out‐of‐plane microwave fields and induce power dissipation, which is confirmed by the phase‐field modeling. Since the contributions from mobile‐carrier conduction and bound‐charge oscillation to the ac conductivity are equivalent in a microwave circuit, the research on local structural dynamics may open a new avenue to implement DW nano‐devices for radio‐frequency applications.

Controlling Single Molecule Conductance by Chemical Reaction

By Tomasz Michnowicz, Bogdana Borca, Rémi Pétuya, Verena Schendel, Marcel Pristl, Ivan Pentegov, Ulrike Kraft, Hagen Klauk, Peter Wahl, Pingo Mutombo, Pavel Jelínek, Andrés Arnau, Uta Schlickum, Klaus Kern from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

Among the prerequisites for the progress of single‐molecule‐based electronic devices are a better understanding of the electronic properties at the individual molecular level and the development of methods to tune the charge transport through molecular junctions. Scanning Tunneling Microscopy (STM) is an ideal tool not only for the characterization, but also for the manipulation of single atoms and molecules on surfaces. The conductance through a single molecule can be measured by contacting the molecule with atomic precision and forming a molecular bridge between the metallic STM tip electrode and the metallic surface electrode. The parameters affecting the conductance are mainly related to their electronic structure and to the coupling to the metallic electrodes. Here, the experimental and theoretical analyses are focused on single tetracenothiophene molecules and demonstrate that an in‐situ‐induced direct desulfurization reaction of the thiophene moiety strongly improves the molecular anchoring by forming covalent bonds between molecular carbon and copper surface atoms. This bond formation leads to an increase of the conductance by about 50% compared to the initial state.

A Microfluidic Ion Sensor Array

By Chunxiao Wu, John Selberg, Brian Nguyen, Pattawong Pansodtee, Manping Jia, Harika Dechiraju, Mircea Teodorescu, Marco Rolandi from Wiley: Small: Table of Contents. Published on Jan 22, 2020.

This work demonstrates an ion‐selective microelectrode array platform for cell culture environment monitoring. The fabrication of the device involves a sequence of steps, including photolithography for patterning traces, electrodeposition for surface modification, and a unique microfluidic strategy for membrane patterning. The system enables simultaneous recording of the ion concentrations of Na+, K+, and Cl− with high sensitivity and selectivity. Abstract A balanced concentration of ions is essential for biological processes to occur. For example, [H+] gradients power adenosine triphosphate synthesis, dynamic changes in [K+] and [Na+] create action potentials in neuronal communication, and [Cl−] contributes to maintaining appropriate cell membrane voltage. Sensing ionic concentration is thus important for monitoring and regulating many biological processes. This work demonstrates an ion‐selective microelectrode array that simultaneously and independently senses [K+], [Na+], and [Cl−] in electrolyte solutions. To obtain ion specificity, the required ion‐selective membranes are patterned using microfluidics. As a proof of concept, the change in ionic concentration is monitored during cell proliferation in a cell culture medium. This microelectrode array can easily be integrated in lab‐on‐a‐chip approaches to physiology and biological research and applications.

Wed 05 Feb 19:30: Understanding and exploiting self-assembly in liquid crystals on multiple length scales

From All Talks (aka the CURE list). Published on Jan 22, 2020.

Understanding and exploiting self-assembly in liquid crystals on multiple length scales

We are all familiar with the concept of materials as solids, liquids and gases. There is a fourth state of matter that exist between solid and liquid states known as liquid crystalline state.

Liquid crystals elegantly combine characteristics of the conventional solid and isotropic liquid and are a fascinating class of opto-electronic materials. The most familiar application of liquid crystals is the liquid crystal displays or LCDs. There are a number of liquid crystal phases and they show unique molecular arrangements and functionalities.

In this presentation, I will outline some of the amazing complex molecular and supramolecular self-assembled structures formed by liquid crystal molecules. I will explain promising methods of exploiting the self-assembled architectures to create novel functional and responsive materials and devices. One of them is by using liquid crystals as a medium to confine nano and microparticles. The effect of dispersing non spherical litho-particles, influence of particle geometry and nature on the physical properties of the colloid will be discussed. The second method is physically transferring the structural features of liquid crystals into polymers by imprinting or templating. Templated structures offer great potential in understanding interfacial interactions between liquid crystals and polymers at the nanoscale. The templated structures allow the use of an assured templated matrix rather than the molecular details of individual chemical compounds to exhibit complex three dimensional ordering. Experimental results of templating one of the recently discovered liquid crystal phases, the twist bend nematic phase, will be shown. The third method is a bottom-up strategy of preparing controlled nano- and micro- structures by combining the spontaneous self-assembly of liquid crystals with nanophase separation behaviour of copolymers. This procedure offers new way of controlling the orientation of the polymer due to controllable interfacial interactions between the liquid crystalline components and air and substrate.

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A Dual Threat: Redox‐Activity and Electronic Structures of Well‐Defined Donor‐Acceptor Fulleretic Covalent‐Organic Materials

By Natalia B. Shustova, Gabrielle A. Leith, Allison M. Rice, Brandon J. Yarbrough, Anna A. Berseneva, Richard T. Ly, Charles N. Buck, Amy J. Brandt, Donna A. Chen, Benjamin W. Lamm, Morgan Stefik, Kenneth S. Stephenson, Mark D. Smith, Aaron K. Vannucci, Perry J. Pellechia, Sophya Garashchuk, Denis Chusov from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

The effect of donor (D)‐acceptor (A) alignment on the materials electronic structure was probed for the first time using novel purely organic porous crystalline materials with covalently integrated two‐ and three‐dimensional acceptors. The first studies towards estimation of charge transfer rates as a function of acceptor stacking are in line with the experimentally observed, drastic ( ca  eight‐fold) conductivity enhancement. Redox behavior of prepared materials, which are the first studies of this kind reported for any buckyball‐ or t etracyanoquinodimethane ‐integrated crystalline porous scaffolds to date, was evaluated. Moreover, in parallel with tailoring the D‐A alignment responsible for “static” changes in materials properties, an external stimulus was applied for the first time to this class of materials for “dynamic” control of the materials’ electronic profiles. Overall, the discussed D‐A strategic design, in combination with stimuli‐controlled electronic behavior, redox activity, and modularity could be used as a blueprint for the development of electroactive and conductive multidimensional and multifunctional crystalline porous materials.

Mitochondrial DNA‐targeted IrIII‐Containing Metallohelices with Tunable Photodynamic Therapy Efficacy in Cancer Cells

By Xuezhao Li, Jinguo Wu, Lei Wang, Cheng He, Liyong Chen, Yang Jiao, Chunying Duan from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

The development of DNA‐targeted photodynamic therapy (PDT) agents for cancer treatment has drawn substantial attention. Here, the design and synthesis of dinuclear Ir III ‐containing luminescent metallohelices with tunable PDT efficacy that targeting mitochondrial DNA in cancer cells are reported. The metallohelices are fabricated using the dynamic imine‐coupling chemistry between aldehyde end‐capped fac‐Ir(ppy) 3 handles and linear alkanediamine spacers, followed by the reduction of the imine‐linkages. Interestingly, the length and odd‐even character of the diamine alkyl linker determined the stereochemical structures (helicates vs mesocates). In contrast to the helicates, the mesocates exhibit improved therapeutic effects for inducing cell apoptosis upon white light irradiation . Molecular docking studies indicate that the mesocates, with a proper length of diamine spacers, show stronger DNA‐binding affinities in a minor groove manner. This study highlights the potential of DNA‐targeting Ir III ‐containing metallohelices as PDT agents and demonstrates that altering the structures of metallohelices can have profound effects on PDT cytotoxicity.

Intracellular Electrochemical Nanomeasurements Reveal that Exocytosis of Molecules at Living Neurons is Subquantal and Complex

By Anna Larsson, Soodabeh Majdi, Alexander Oleinick, Irina Svir, Christian Amatore, Andrew G. Ewing from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

Since the early work of Bernard Katz, the process of cellular chemical communication via exocytosis, quantal release, has been considered to be all or none. Recent evidence has shown exocytosis to be partial or ‘subquantal’ at single‐cell model systems, but there is a need to understand this at communicating nerve cells. Partial release allows nerve cells to control the signal at the site of release during individual events, where the smaller the fraction released, the greater the range of regulation. Here we show that the fraction of the vesicular octopamine content released from a living  Drosophila  larval neuromuscular neuron is very small. The percentage of released molecules was found to be only 4.5% for simple events and 10.7% for complex (i.e., oscillating or flickering) events. This large content, combined with partial release controlled by fluctuations of the fusion pore, offers presynaptic plasticity that can be widely regulated.

Layer‐by‐Layer Assembled Oxide Nanoparticle Electrodes with High Transparency, Electrical Conductivity, and Electrochemical Activity by Reducing Organic Linker‐Induced Oxygen Vacancies

By Ikjun Cho, Yongkwon Song, Sanghyuk Cheong, Younghoon Kim, Jinhan Cho from Wiley: Small: Table of Contents. Published on Jan 22, 2020.

Highly transparent and conductive electrodes are realized by oxygen‐vacancy‐controlled layer‐by‐layer assembly. Extremely small hydrazine molecules with chemically reducing properties effectively reduce the separation distance between neighboring indium tin oxide nanoparticles (ITO NPs) and induce oxygen vacancy states within ITO NPs, resulting in significantly enhanced electrical properties of electrodes. Abstract Solution‐processable transparent conducting oxide (TCO) nanoparticle (NP)–based electrodes are limited by their low electrical conductivity, which originates from the low level of oxygen vacancies within NPs and the contact resistance between neighboring NPs. Additionally, these electrodes suffer from the troublesome trade‐off between electrical conductivity and optical transmittance and the restricted shape of substrates (i.e., only flat substrates). An oxygen‐vacancy‐controlled indium tin oxide (ITO) NP‐based electrode is introduced using carbon‐free molecular linkers with strong chemically reducing properties. Specifically, ITO NPs are layer‐by‐layer assembled with extremely small hydrazine monohydrate linkers composed of two amine groups, followed by thermal annealing. This approach markedly improves the electrical conductivity of ITO NP‐based electrodes by significantly increasing the level of oxygen vacancies and decreasing the interparticle distance (i.e., contact resistance) without sacrificing optical transmittance. The prepared electrodes surpass the optical/electrical performance of TCO NP‐based electrodes reported to date. Additionally, the nanostructured ITO NP films can be applied to more complex geometric substrates beyond flat substrates, and furthermore exhibit a prominent electrochemical activity. This approach can provide an important basis for developing a wide range of highly functional transparent conducting electrodes.

Symmetry‐Reduction Enhanced Polarization‐Sensitive Photodetection in Core–Shell SbI3/Sb2O3 van der Waals Heterostructure

By Mengqi Xiao, Huai Yang, Wanfu Shen, Chunguang Hu, Kai Zhao, Qiang Gao, Longfei Pan, Liyuan Liu, Chengliang Wang, Guozhen Shen, Hui‐Xiong Deng, Hongyu Wen, Zhongming Wei from Wiley: Small: Table of Contents. Published on Jan 22, 2020.

Core–shell SbI3/Sb2O3 nanowires are synthesized and fabricated as polarization‐sensitive photodetectors. SbI3/Sb2O3 nanowires possess high anisotropy crystal structure due to symmetry reduction, which facilitate superior polarized detectivity from UV to visible light. Abstract Structural symmetry is a simple way to quantify the anisotropic properties of materials toward unique device applications including anisotropic transportation and polarization‐sensitive photodetection. The enhancement of anisotropy can be achieved by artificial symmetry‐reduction design. A core–shell SbI3/Sb2O3 nanowire, a heterostructure bonded by van der Waals forces, is introduced as an example of enhancing the performance of polarization‐sensitive photodetectors via symmetry reduction. The structural, vibrational, and optical anisotropies of such core–shell nanostructures are systematically investigated. It is found that the anisotropic absorbance of a core–shell nanowire is obviously higher than that of two single compounds from both theoretical and experimental investigations. Anisotropic photocurrents of the polarization‐sensitive photodetectors based on these core–shell SbI3/Sb2O3 van der Waals nanowires are measured ranging from ultraviolet (UV) to visible light (360–532 nm). Compared with other van der Waals 1D materials, low anisotropy ratio (Imax/Imin) is measured based on SbI3 but a device based on this core–shell nanowire possesses a relatively high anisotropy ratio of ≈3.14 under 450 nm polarized light. This work shows that the low‐symmetrical core–shell van der Waals heterostructure has large potential to be applied in wide range polarization‐sensitive photodetectors.

B,N Codoped Graphitic Nanotubes Loaded with Co Nanoparticles as Superior Sulfur Host for Advanced Li–S Batteries

By Zhuosen Wang, Jiadong Shen, Shaomin Ji, Xijun Xu, Shiyong Zuo, Zhengbo Liu, Dechao Zhang, Renzong Hu, Liuzhang Ouyang, Jun Liu, Min Zhu from Wiley: Small: Table of Contents. Published on Jan 22, 2020.

Bean‐like B,N codoped carbon nanotubes loaded with Co nanoparticles (Co@BNTs) are fabricated. In this nanostructure, the loaded Co nanoparticles and codoped B,N sites significantly suppress the “shuttle effect” by strong chemical interaction and offer more active sites to catalyze the redox reaction of sulfur cathode. Abstract Lithium–sulfur batteries (LSBs) are considered as one of the best candidates for novel rechargeable batteries due to their high energy densities and abundant required materials. However, the poor conductivity and large volume expansion of sulfur and the “shuttle effect” of lithium polysulfides (LPSs) have significantly hindered the development and successful commercialization of LSBs. Bean‐like B,N codoped carbon nanotubes loaded with Co nanoparticles (Co@BNTs), which can act as advanced sulfur hosts for the novel LSB cathode, are fabricated. Uniform graphitic nanotubes improve the conductivity of the electrode and load more electroactive sulfur and buffer volume expansion during the electrochemical reaction. In addition, loaded Co nanoparticles and codoped B,N sites can significantly suppress the “shuttle effect” of LPSs with strong chemical interaction. It is established that the Co nanoparticles and codoped B,N can provide more active sites to catalyze the redox reaction of sulfur cathode. This stable Co@BNTs‐S cathode displays an exceptional electrochemical performance (1160 mA h g−1 after 200 cycles at 0.1 C) and outstanding stable cycle performance (1008 mA h g−1 after 400 cycles at 1.0 C with an extremely low attenuation rate of 0.038% per cycle).

Titanium Incorporation into Zr‐Porphyrinic Metal–Organic Frameworks with Enhanced Antibacterial Activity against Multidrug‐Resistant Pathogens

By Mian Chen, Zhou Long, Ruihua Dong, Le Wang, Jiangjiang Zhang, Sixiang Li, Xiaohui Zhao, Xiandeng Hou, Huawu Shao, Xingyu Jiang from Wiley: Small: Table of Contents. Published on Jan 22, 2020.

This study uses metal–organic frameworks alone without any added antibacterial ingredients as the nonantibiotic agent for photodynamic therapy of chronic wounds infected by multidrug‐resistant bacteria. The Ti incorporation could greatly boost the generation of reactive oxygen species for effective elimination of multidrug‐resistant bacteria, and the validated biocompatibility of PCN‐224(Zr/Ti) would ensure the biosafety for photodynamic therapy. Abstract This study uses metal–organic frameworks (MOFs) alone without any added antibacterial ingredients as the nonantibiotic agent for photodynamic therapy (PDT) of chronic wounds infected by multidrug‐resistant (MDR) bacteria. Nanoparticles (NPs) of MOFs (PCN‐224) are incorporated with titanium through a facile cation exchange strategy. The obtained bimetallic PCN‐224(Zr/Ti) shows greatly enhanced photocatalytic performance for the generation of reactive oxygen species under visible light, which is responsible for the effective antibacterial activities. The PCN‐224(Zr/Ti) NPs are loaded onto lactic‐co‐glycolic acid nanofibers to prepare a wound dressing, which shows high biocompatibility and minimal cytotoxicity. The wound dressing is efficient for PDT‐based in vivo healing of the chronic wound infected by MDR bacteria. Most importantly, this work does not involve any additional antibacterial agents, which is facile, low cost, and in particular, greatly explores the potential of MOFs as a powerful nonantibiotic agent in PDT.

Wed 11 Mar 16:00: A zero-item personality test? Predicting personality traits from social media data

From All Talks (aka the CURE list). Published on Jan 22, 2020.

A zero-item personality test? Predicting personality traits from social media data

Many researchers, including myself (e.g. Kosinski, Graepel & Stillwell, 2013), have published papers showing that psychological traits like personality and intelligence can be predicted from the digital footprints people leave behind when they use online services like social media. But are these predictions psychometrically reliable, valid, and unbiased? The Facebook Cambridge Analytica scandal clearly demonstrates that the public is uneasy when they feel their data was misused, but on the other hand the public also likes their data to be used to personalise recommendations and services. Ultimately, should this technology be used in practice, and if so under what conditions?

Dr. David Stillwell is Lecturer in Big Data Analytics and Quantitative Social Science at Judge Business School in the University of Cambridge. He is also Academic Director of the Psychometrics Centre. David studies the links between big data and psychology; his research with 6 million social media users found that the computer can predict a user’s personality as accurately as their spouse can. Follow up research found that personalizing an advert to the recipient’s psychology is more effective than generic ads. David has also published research using various big data sources to show that spending money on products and services that match one’s personality leads to greater life satisfaction, that people tend to date others who have a similar personality, and that people who swear seem to be more honest.

Twitter: @david_stillwell

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Fri 21 Feb 14:00: Geometry and rheology of epithelial monolayers

From All Talks (aka the CURE list). Published on Jan 22, 2020.

Geometry and rheology of epithelial monolayers

Abstract not available

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Thu 05 Mar 16:00: Forensic explosives analysis

From All Talks (aka the CURE list). Published on Jan 22, 2020.

Forensic explosives analysis

Robust and reliable forensic analysis is important for criminal cases in which the misuse of explosives or other energetic materials is suspected. The outcomes of such analysis can help to direct investigations and, ultimately, support the Criminal Justice System through expert testimony. In the mainland UK, forensic analysis of explosive materials is undertaken by the Forensic Explosives Laboratory (FEL), part of the Defence Science and Technology Laboratory (Dstl).

Prior to joining the SMF Group in 2019, Mike was the Technical Lead for Capability Development at FEL and, in particular, was heavily involved in the development and validation of the tools and techniques used across the laboratory. In this talk, Mike will discuss some of the projects he has been involved with throughout his career and the unique challenges of delivering research and development in a forensic context. In so doing, he will explain some aspects of explosives chemistry as well as relevant analytical techniques and the communication of results to the Criminal Justice System.

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Wed 22 Apr 13:00: The role of FoxN3 in the development of the chondrocranium and associated head muscles in the African Clawed-frog, Xenopus laevis

From All Talks (aka the CURE list). Published on Jan 22, 2020.

The role of FoxN3 in the development of the chondrocranium and associated head muscles in the African Clawed-frog, Xenopus laevis

Studies of chondrocranium evolution and development has led to the discovery of major genes and mechanisms that govern its early development. However, many of the genetic interactions forming the gene regulatory network controlling cell condensation, chondrogenesis and morphogenesis of the chondrocranium are still poorly understood. FoxN3 has been reported to be crucial for the normal development of neural crest-derived elements of the chondrocranium and its associated muscles in Xenopus laevis. But the genetic interactions by which FoxN3 regulates chondrogenesis and muscle development in the head of X. laevis are still poorly known. We used Morpholino-mediated knock down in combination with qRT-PCR and whole-mount in situ hybridization to analyse potential target genes of FoxN3. The temporal and spatial expressions of different cartilage, muscle and joint markers as well as cell adhesion molecules are changed following FoxN3 depletion. Expression of N-CAM and N-Cadherin is decreased throughout development and expression of genes important for cartilage formation (Sox-9, Col2α1, Runx-2) is delayed. Joint markers (Gdf5/6) and genes (Dlx5/6) important for regional specification are also down-regulated. Additionally, expression levels of key myogenic genes such as MyoD and of structural muscle genes are reduced compared to control embryos. This results in smaller cartilage and muscle anlagen and incomplete development of neural crest-, but not mesodermal-, derived elements of the chondrocranium. Additionally, FoxN3 is important for the formation of the intermediate domain during joint development in the head of X. laevis. It seems that FoxN3 plays a key role upstream of a complex gene regulatory network maintaining normal cartilage and joint formation of the chondrocranium and proper development of the muscles connected to it.

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Intrinsically Low Thermal Conductivity and High Carrier Mobility in Dual Topological Quantum Material, n‐type BiTe

By Kanishka Biswas, Manisha Samanta, Koushik Pal, Umesh V. Waghmare from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

The grand challenge in thermoelectrics is to achieve the intrinsically low thermal conductivity in crystalline solids while maintaining the high carrier mobility (µ). While topological quantum materials such as topological insulator (TI) or topological crystalline insulator (TCI) can exhibit high µ, weak topological insulators (WTI) are of interest due to their layered hetero‐structural nature which is intriguing for exhibiting low lattice thermal conductivity (κlat). BiTe, a unique member of the (Bi2)m(Bi2Te3)n homologous series (where m:n = 1:2), possesses both the quantum states, TCI and WTI, which is distinct from the conventional strong TI, Bi2Te3 (where m:n = 0:1). In BiTe, Bi‐Bi zigzag bilayer is sandwiched between the Te‐Bi‐Te‐Bi‐Te quintuple layers bonded via weak van der Waals interactions. Here, we report intrinsically low κlat of 0.47‐ 0.8 W/mK in the 300‐650 K range in BiTe due to the presence of low energy optical phonon branches which originate primarily from the localized vibrations of Bi bilayer. These soft optical modes couple strongly with the acoustic modes, hindering the propagation of acoustic phonons, resulting in a low κlat. BiTe exhibits negative Seebeck coefficients attributing to n‐type electronic conduction. BiTe possesses high µ of ~ 516 cm2/Vs and 707 cm2/Vs along parallel and perpendicular to the spark plasma sintering (SPS) directions, respectively, at room temperature. Electronic structure of BiTe reveals that multiple band extrema in the conduction bands with nearly linear dispersion in a narrow energy window (~25 meV) corresponding to the thermal energy at room temperature, resulting in a facile conduction channel; hence supports manifestation of high µ.

Thu 06 Feb 15:00: The SPHERE project

From All Talks (aka the CURE list). Published on Jan 22, 2020.

The SPHERE project

Abstract: SPHERE started in 2013 with the aim to create the “Ultimate Behavioural Sensing Machine” – a set of capabilities that could capture aspects of free-living human behaviour over long periods of time that have traditionally been very difficult or impossible to acquire. The SPHERE technology includes environmental, wearable and video sensing. The talk will describe the technologies developed and integrated, some of the real world challenges encountered and will show some of the data obtained so far from hundreds of people around the UK. The talk will also describe opportunities to access that data for research purposes.

Bio: Professor Ian Craddock has a cross-Faculty position as Institutional Lead for Digital Health at the University of Bristol. He is a Fellow of the IEEE and the IET . He has had research leadership roles in both academia (including the flagship EPSRC SPHERE project 2013-2021) and industry (as Director of Toshiba’s Bristol Research Laboratory 2011-2019).

He has long-standing interests in electronics, computer science, healthcare and in ethics. He has chaired numerous national grant review panels, served on national research strategy boards and is a panel member for REF2021 , the UK’s national audit of University research quality.

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Modulation of Prins Cyclization by Vibrational Strong Coupling

By Kenji Hirai, Rie Takeda, James A. Hutchison, Hiroshi Uji-i from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

Light‐molecule strong coupling has emerged within the last decade as an entirely new method to control chemical reactions. A few years ago it was discovered that the chemical reactivity could be altered by vibrational strong coupling (VSC). While the potential of VSC in organic chemistry appears enormous, only a limited number of reactions have been investigated under VSC to date, including solvolysis and deprotection reactions. Here we investigate the effect of VSC on a series of aldehydes and ketones undergoing Prins cyclization, an important synthetic step in pharmaceutical chemistry. We observe a decrease of the second‐order rate constant with VSC of the reactant carbonyl stretching groups. We measure an increased activation energy due to VSC, but proportional changes in activation enthalpy and entropy suggest no substantive change in reaction pathway. The addition of common cycloaddition reactions to the stable of VSC‐modified chemical reactions is another step towards establishing VSC as a genuine tool for synthetic chemistry.

Phosphorus vacancies boost electrocatalytic hydrogen evolution by two orders of magnitude

By Jingjing Duan, Sheng Chen, César Ortíz‐Ledón, Mietek Jaroniec, Shizhang Qiao from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

Vacancy engineering is an effective strategy to manipulate the electronic structure of electrocatalysts to improve their performance; while few reports focus on phosphorus vacancies (Pv). Herein, we report the creation of Pv in metal phosphides and investigate their role in alkaline electrocatalytic hydrogen evolution reaction (HER). The Pv‐modified catalyst requires a minimum onset potential of 0 mV vs RHE, a small overpotential of 27.7 mV to achieve 10 mA cm ‐2 geometric current density and a Tafel slope of 30.88 mV dec ‐1 , even outperforms Pt/C benchmark (32.7 mV@10 mA cm ‐2 and 30.90 mV dec ‐1 ). This catalyst also displays superior stability up to 504 hours without any decay. Experimental analysis and density functional theory calculations suggest Pv can weaken the hybridization of Ni 3d and P 2p orbitals, enriching the electron density of Ni and P atoms nearby Pv, facilitating H* desorption process, contributing to outstanding HER activity and facile kinetics.

Layered‐Perovskite Nanowires with Long‐Range Orientational Order for Ultrasensitive Photodetectors

By Yingjie Zhao, Yuchen Qiu, Hanfei Gao, Jiangang Feng, Gaosong Chen, Lei Jiang, Yuchen Wu from Wiley: Advanced Materials: Table of Contents. Published on Jan 22, 2020.

2D‐perovskite single‐crystalline nanowire arrays are realized by the synergy of solvent engineering and the capillary‐bridge lithography technique. Nucleation of layered perovskites occurring at liquid–air interfaces and unidirectional growth along the dewetting direction are demonstrated. Single‐crystalline nanowire arrays integrate ultralow noises and considerable photocurrents, yielding ultrasensitive photodetectors with responsivity exceeding 1.1 × 104 A W−1 and detectivity exceeding 9.1 × 1015 Jones. Abstract 2D layered metal‐halide perovskites combine efficient exciton radiative recombination in crystal interior with long‐distance free‐carrier conduction at layer edges, which are promising candidates for realizing high‐performance photovoltaic, light‐emission and photodetection devices. The anisotropic electrical conductivity in layered perovskites imposes an additional requirement of orientational control for enabling favorable charge transport. However, rational fabrication of single‐crystalline nanostructures with pure crystallographic orientation is still elusive. Herein, large‐scale pure (101)‐orientated 2D‐perovskite single‐crystalline nanowire arrays are realized by combining solvent engineering with the capillary‐bridge lithography technique. Ordered nucleation at liquid–air interface and unidirectional growth along the dewetting direction are demonstrated by fluorescence microscopy and grazing‐incidence X‐ray scattering in discrete capillary bridges. In consideration of crystal interior exhibiting high resistance arising from the serial insulating organic barriers and ultrafast dissociation of excitons to generate long‐lived free carriers at layer edges, ultrasensitive photodetectors are demonstrated with average responsivity exceeding 1.1 × 104 A W−1 and detectivity exceeding 9.1 × 1015 Jones.

Thu 06 Feb 13:00: Are star lawyers also better lawyers?

From All Talks (aka the CURE list). Published on Jan 22, 2020.

Are star lawyers also better lawyers?

We study the performance of dominant law firms (“stars”) in litigation brought against publicly traded corporations. We use insurance coverage as a benchmark for expected settlement amounts, to separate to what extent (a) stars reach more favorable settlements on any lawsuit (a performance or treatment effect) or (b) stars are retained in lawsuits where a favorable settlement is ex ante more likely (a selection effect). Our findings indicate the latter, and that star firms have an economically small impact on settlement amounts. This result is not explained by measurement error or over-/under-insurance. The extent to which stars are associated with improvements in corporate governance also appears limited. The stars’ large market share and the high fees they earn may be justified by their ability to reduce uncertainty about the lawsuit outcome or by frictions, such as aggressive marketing and limited client sophistication and bargaining power, which limits the stars’ clients’ ability to turn to other law firms.

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Synthesis and Reactivity of Cationic Boron Complexes Distorted by Pyridine‐based Pincer Ligands: Isolation of a Photochemical Hofmann‐Martius‐type Intermediate

By Trevor Janes, Yael Diskin-Posner, David Milstein from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

A family of cationic boron complexes was synthesized, using a dianilidopyridine pincer ligand, which imposes in‐plane distortion of the geometry at boron towards T‐shaped. Reactivity of these cations toward hydride and base was investigated, and the utility of these cations as precursors to a variety of π‐conjugated BN heterocycles was demonstrated. 300 nm irradiation of a deprotonated pincer boron complex triggered a C‐N cleavage/C‐C formation yielding a dearomatized boryl imine, which has a structure akin to the long‐proposed intermediate in the photochemical Hofmann‐Martius rearrangement. The photo‐rearrangement triggers relief of the distortion imposed by the pincer ligand.

Enantioselective Construction of Axially Chiral Amino Sulfide Vinyl Arenes via Chiral Sulfide‐Catalyzed Electrophilic Carbothiolation of Alkynes

By Xiaodan Zhao, Yaoyu Liang, Jieying Ji, Xiaoyan Zhang, Quanbin Jiang, Jie Luo from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

Enantioselective construction of axially chiral compounds via electrophilic carbothiolation of alkynes is disclosed for the first time. This enantioselective transformation is enabled by the use of Ts‐protected bifunctional sulfide catalyst and Ms‐protected ortho‐alkynylaryl amines. Both electrophilic arylthiolating and electrophilic trifluoromethylthiolating reagents are suitable for this reaction. The obtained products of axially chiral vinyl‐aryl amino sulfides can be easily converted into biaryl amino sulfides, biaryl amino sulfoxides, biaryl amines, vinyl‐aryl amines, and other valuable difunctionalized compounds.

Fri 07 Feb 14:00: On Statistical Learning for Individualized Decision Making with Complex Data

From All Talks (aka the CURE list). Published on Jan 22, 2020.

On Statistical Learning for Individualized Decision Making with Complex Data

In this talk, I will present my research on individualized decision making with modern complex data. In precision medicine, individualizing the treatment decision rule can capture patients’ heterogeneous response towards treatment. In finance, individualizing the investment decision rule can improve individual’s financial well-being. In a ride-sharing company, individualizing the order dispatching strategy can increase its revenue and customer satisfaction. With the fast development of new technology, modern datasets often consist of massive observations, high-dimensional covariates and are characterized by some degree of heterogeneity. The talk is divided into two parts. In the first part, I will focus on the data heterogeneity and introduce a new maximin-projection learning for recommending an overall individualized decision rule based on the observed data from different populations with heterogeneity in optimal individualized decision making. In the second part, I will briefly summarize the statistical learning methods I’ve developed for individualized decision making with complex data.

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Homonuclear Decoupling in 1H NMR of Solids by Remote Correlation

By Pinelopi Moutzouri, Federico Paruzzo, Bruno Simões de Almeida, Gabriele Stevanato, Lyndon Emsley from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

The typical linewidths of  1 H NMR spectra of powdered organic solids at 111 kHz magic angle spinning (MAS) are of the order of a few hundred Hertz. While this is remarkable  in comparison to the tens of kHz observed in spectra of static samples, it is still the key limit to the use of  1 H in solid‐state NMR, especially for complex systems. Here, we demonstrate a novel strategy to further improve the spectral resolution. We show that the anti‐z‐COSY experiment can be used to reduce the residual line broadening of  1 H NMR spectra of powdered organic solids. Results obtained with the anti‐z‐COSY sequence at 100 kHz MAS on thymol,  β ‐AspAla, and strychnine  show an improvement in resolution of up to a factor of two compared to conventional spectra acquired at the same spinning rate.

Thu 28 May 14:15: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 22, 2020.

Title to be confirmed

Abstract not available

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Structural Modification of Triphenylamine Derivatives vs the Minimization of Carrier Losses for Efficient Perovskite Solar Cells.

By Emilio Jose Palomares, Cristina Rodríguez-Seco, Maria Mendez, Cristina Roldan-Carmona, Ravi Pudi, Md. K. Nazeeruddin from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

Three hole transport materials (HTMs) based on a substituted triphenylamine moiety have been synthetized and successfully employed in triple‐cation mixed‐halide PSCs, reaching efficiencies of 19.4%. The efficiencies, comparable to those obtained using spiro‐OMeTAD, point them out as promising candidates for easily attainable and cost‐effective alternatives for PSCs, given their facile synthesis from commercially available materials. Interestingly, although all these HTMs present close chemical and physical properties, they provide different carrier recombination kinetics. Our results demonstrate that is feasible through the molecular design of the HTM to minimize carrier losses and, thus, increase the solar cell efficiencies.

Metal‐Organic Frameworks for the Exploit of Distance between Active Sites in Efficient Photocatalysis

By Yufei Shu, Xuan Gong, Zhuo Jiang, Lingxiang Lu, Xiaohui Xu, Chao Wang, Hexiang Deng from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

Discoveries of the accurate spatial arrangement of active sites in biological systems and the cooperation between them to achieve high catalytic efficiency are two major events in biology. However, precise tuning of these aspects is largely missing in the design of artificial catalysts. Here, we used a series of metal‐organic frameworks (MOFs), not only overcame the limit of distance between active sites in bio‐systems, but also unveiled the critical role of this distance for efficient catalysis. A linear correlation was established between photocatalytic activity and the reciprocal of inter active site distance, where smaller distance led to higher activity. Moreover, we found that vacancies created at selected crystallographic positions of MOFs further promoted their photocatalytic efficiency. MOF‐525‐J33 with 15.6 Å inter active site distance and 33% vacancies exhibited unprecedented high turnover frequency of 29.5 h ‐1 in visible light driven acceptorless dehydrogenation of tetrahydroquinoline at room temperature.

Mon 10 Feb 18:00: Modern Molecular Science and How It Is Changing Our Life

From All Talks (aka the CURE list). Published on Jan 22, 2020.

Modern Molecular Science and How It Is Changing Our Life

Abstract not available

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Thu 20 Feb 11:30: Towards the control of transition to turbulence

From All Talks (aka the CURE list). Published on Jan 22, 2020.

Towards the control of transition to turbulence

Transition to turbulence is a common instability in which a laminar flow evolves into spatio-temporal chaos. It affects a number of applications involving the displacement of fluid such as fluid transport and aerodynamics. When a flow transitions to turbulence, wall friction and drag increase, impacting negatively the above applications and creating the need for control. The engineering literature has, so far, mainly focused on alleviating the effects of turbulence. We take a different approach: we do not consider fully developed turbulent flows but rather aim to postpone the transition to it.

In this talk, we will consider one of the simplest examples of transitional flows (plane Couette flow), where transition occurs through a finite-amplitude instability: a perturbation of sufficient energy is necessary to trigger transition. We will discuss two ideas to facilitate the control of transition. Firstly, we will assess the robustness of the laminar flow by computing the probability that random perturbations transition as a function of their amplitude. Secondly, as transition involves spatially localized turbulent spots, we will discuss the dynamics of steady spatially localized solutions and determine under which conditions they yield long-lasting chaos. Both of these ideas will be presented in the absence of control to establish a benchmark and will then be tested in the presence of a well-studied control strategy. Quantitative conclusions on the efficiency of the control will be drawn.

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Thu 13 Feb 11:30: Rocking the boat: The physics of kayaks, canoes and rowing

From All Talks (aka the CURE list). Published on Jan 22, 2020.

Rocking the boat: The physics of kayaks, canoes and rowing

In this talk I will present two topics related to the physics of boat sports: The first explains the shape of a kayak – and why it’s different to a dolphin. The second explains how to beat Olympic records by choosing the correct water depth!

More than a century ago, J.H. Michell derived an integral formula for the wave drag on a moving body, using the approximation of a slender body in an irrotational, inviscid fluid (Michell 1898). The major shortcoming of this formula is that, due to the reversibility of the steady potential flow formulation, it predicts no difference in the wave drag when an object with front-back asymmetry moves forwards or backwards. However, anyone who has tried to row a dinghy in the wrong direction would argue differently! In the first part of my talk, I will discuss recent experimental observations investigating the effects of body asymmetry on wave drag, and show that these effects can be replicated by modifying Michell’s theory to include the growth of a symmetry-breaking boundary layer. I will demonstrate that asymmetry can have either a positive or a negative effect on drag, depending on the depth of motion and the Froude number, explaining the difference in shape between a kayak and a dolphin.

Another factor which strongly affects the wave drag is the water depth. Olympic race courses have a minimum depth requirement of 3m, but with boats as long as 18m, rowers are likely to generate waves in both the deep (dispersive) and shallow (non-dispersive) regimes at various moments during a race. Entering from deep to shallow water is accompanied by a focusing of the wave drag near the shallow wave speed – and hence the emergence of co-existing fast and slow solution branches. In the second half of my talk, I will describe the non-linear dynamics of such motion, including sketches of possible bifurcation patterns and hysteresis routes during a race. I will demonstrate the existence of both dead and anti-dead regions of shallow water – and how they may be responsible for recent Olympic records.

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Wed 19 Feb 14:15: Nuclear Quantum Effects – Fast and Accurate

From All Talks (aka the CURE list). Published on Jan 22, 2020.

Nuclear Quantum Effects – Fast and Accurate

Quantum nuclear effects plays a central role in determining properties of systems that contain light nuclei. For instance, the large deviation of the heat capacity of a solid from the Delong’s Petit limit and of the particle momentum distribution from the Maxwell-Boltzmann behaviour are direct manifestations of the quantum nature of nuclei. While these effects can be accurately modelled in atomistic simulations by employing the imaginary time path integral (PI) technique [1], the high computational cost of running PI simulations has prevented their widespread use. In this talk, I will introduce molecular dynamics based methods [2, 3, 4, 5] that substantially reduce the computational cost of PI simulations and their implementation in an open source software i-PI. [6] Going beyond benchmarks, I will demonstrate the relevance of these advances by studying different properties and classes of materials – such as the proton momentum distribution in water that relates to the local structure of protons in ice [4] and facilitates interpretation of complex Deep Inelastic Neutron scattering experiments, quantum effects that facilitate isotope separation in porous organic cages [7], tuning of thermal properties of metal-organic cages loaded with greenhouse gases [5], and quantitative estimation of quantum mechanical effects that stabilize pharmaceutically active molecular crystals [8] – at a fraction of the computational cost if using conventional techniques. References [1] David Chandler and Peter G. Wolynes. Exploiting the isomorphism between quantum theory and classical statistical mechanics of polyatomic fluids. The Journal of Chemical Physics, 74(7):4078– 4095, April 1981. [2] V. Kapil, J. VandeVondele, and M. Ceriotti. Accurate molecular dynamics and nuclear quantum effects at low cost by multiple steps in real and imaginary time: Using density functional theory to accelerate wavefunction methods. The Journal of Chemical Physics, 144(5):054111, February 2016. [3] Venkat Kapil, J ̈org Behler, and Michele Ceriotti. High order path integrals made easy. The Journal of Chemical Physics, 145(23):234103, December 2016. [4] Venkat Kapil, Alice Cuzzocrea, and Michele Ceriotti. Anisotropy of the Proton Momentum Distribution in Water. The Journal of Physical Chemistry B, 122(22):6048–6054, June 2018. [5] Venkat Kapil, Jelle Wieme, Steven Vandenbrande, Aran Lamaire, Veronique Van Speybroeck, and Michele Ceriotti. Modeling the Structural and Thermal Properties of Loaded Metal–Organic Frameworks. An Interplay of Quantum and Anharmonic Fluctuations. Journal of Chemical Theory and Computation, 15(5):3237–3249, May 2019. [6] Venkat Kapil, Mariana Rossi, Ondrej Marsalek, Riccardo Petraglia, Yair Litman, Thomas Spura, Bingqing Cheng, Alice Cuzzocrea, Robert H. Meißner, David M. Wilkins, Benjamin A. Hel- frecht, Przemysl􏰀aw Juda, S ́ebastien P. Bienvenue, Wei Fang, Jan Kessler, Igor Poltavsky, Steven Vandenbrande, Jelle Wieme, Clemence Corminboeuf, Thomas D. Ku ̈hne, David E. Manolopou- los, Thomas E. Markland, Jeremy O. Richardson, Alexandre Tkatchenko, Gareth A. Tribello, Veronique Van Speybroeck, and Michele Ceriotti. i-PI 2.0: A universal force engine for advanced molecular simulations. Computer Physics Communications, 236:214–223, March 2019. [7] Ming Liu, Linda Zhang, Marc A. Little, Venkat Kapil, Michele Ceriotti, Siyuan Yang, Lifeng Ding, Daniel L. Holden, Rafael Balderas-Xicoht ́encatl, Donglin He, Rob Clowes, Samantha Y. Chong, Gisela Schu ̈tz, Linjiang Chen, Michael Hirscher, and Andrew I. Cooper. Barely porous organic cages for hydrogen isotope separation. Science, 366(6465):613–620, November 2019. [8] Venkat Kapil, Edgar Engel, Mariana Rossi, and Michele Ceriotti. Assessment of Approxi- mate Methods for Anharmonic Free Energies. Journal of Chemical Theory and Computation, 15(11):5845–5857, November 2019.

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Molecular Semiconductors for Logic Operations: Dead‐End or Bright Future?

By Guillaume Schweicher, Guillaume Garbay, Rémy Jouclas, François Vibert, Félix Devaux, Yves H. Geerts from Wiley: Advanced Materials: Table of Contents. Published on Jan 22, 2020.

Organic semiconductors for logic operation are currently facing a crisis because charge carrier mobility tends to level off, the industrial interest is fading away, and more than half of transport measurements in transistors are stained by errors. However, the field remains particularly rich of opportunities for new academic and even industrial developments if fundamental issues are addressed. Abstract The field of organic electronics has been prolific in the last couple of years, leading to the design and synthesis of several molecular semiconductors presenting a mobility in excess of 10 cm2 V−1 s−1. However, it is also started to recently falter, as a result of doubtful mobility extractions and reduced industrial interest. This critical review addresses the community of chemists and materials scientists to share with it a critical analysis of the best performing molecular semiconductors and of the inherent charge transport physics that takes place in them. The goal is to inspire chemists and materials scientists and to give them hope that the field of molecular semiconductors for logic operations is not engaged into a dead end. To the contrary, it offers plenty of research opportunities in materials chemistry.

Asymmetric Three‐Component Heck/Amination of Nonconjugated Cyclodienes

By Jianrong Steve Zhou, Daoyong Zhu, Yonggui Robin Chi, Zhiwei Jiao, Théo P Gonçalves, Kuo-Wei Huang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 22, 2020.

Asymmetric Heck/amination of nonconjugated cyclodienes proceeds to give substituted cyclohexenylamines in good enantioselectivity and exclusive trans configurations. Substituted chiral cyclohexylamines are becoming increasingly important in drug discovery. Suitable amines in this reaction include primary and secondary anilines, indoline and benzylamines. A weakly‐donating diphosphite, Kelliphite forms a deep unsymmetrical pocket, which is essential for stereoselective anti‐attack of external amines.

[ASAP] Site-Specific Sodiation Mechanisms of Selenium in Microporous Carbon Host

By Fre´de´ric A. Perras*†, Sooyeon Hwang‡, Yixian Wang§, Ethan C. Self?, Pengcheng Liu§, Rana Biswas†?#, Sudhan Nagarajan§, Viet Hung Pham§, Yixin Xu‡?, J. Anibal Boscoboinik‡, Dong Su‡, Jagjit Nanda?, Marek Pruski†¶, and David Mitlin*§ from Nano Letters: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Nano Letters
DOI: 10.1021/acs.nanolett.9b03797

[ASAP] Liposome Imaging in Optically Cleared Tissues

By Abdullah Muhammad Syed†?, Presley MacMillan‡?, Jessica Ngai†§?, Stefan Wilhelm?, Shrey Sindhwani†, Benjamin R. Kingston†, Jamie L. Y. Wu†, Pablo Llano-Sua´rez?, Zachary Pengju Lin†, Ben Ouyang†, Zaina Kahiel#, Suresh Gadde#, and Warren C. W. Chan*†‡§¶? from Nano Letters: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Nano Letters
DOI: 10.1021/acs.nanolett.9b04853

[ASAP] Alkali Cation Doping for Improving the Structural Stability of 2D Perovskite in 3D/2D PSCs

By Chang Liu*†§, Jingsong Sun‡, Wen Liang Tan‡, Jianfeng Lu§, Thomas R. Gengenbach?, Christopher R. McNeill‡, Ziyi Ge†, Yi-Bing Cheng‡?, and Udo Bach*§ from Nano Letters: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Nano Letters
DOI: 10.1021/acs.nanolett.9b04661

[ASAP] Therapeutic Contact Lens for Scavenging Excessive Reactive Oxygen Species on the Ocular Surface

By Seung Woo Choi†, Bong Geun Cha‡, and Jaeyun Kim*†‡§? from ACS Nano: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b10145

[ASAP] Correction to Quercetin-Modified Metal–Organic Frameworks for Dual Sensitization of Radiotherapy in Tumor Tissues by Inhibiting the Carbonic Anhydrase IX

By Tengchuang Ma, Yunduo Liu, Qiong Wu, Lifang Luo, Yali Cui, Xinghua Wang, Xiuwei Chen*, Longfei Tan*, and Xianwei Meng* from ACS Nano: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b09760

[ASAP] Electronic Structures and Reactivity Profiles of Aryl Nitrenoid-Bridged Dicopper Complexes

By Kurtis M. Carsch†, James T. Lukens‡, Ida M. DiMucci‡, Diana A. Iovan†, Shao-Liang Zheng†, Kyle M. Lancaster*‡, and Theodore A. Betley*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b09616

[ASAP] Ultrafast Dynamics and Vibrational Relaxation in Six-Coordinate Heme Proteins Revealed by Femtosecond Stimulated Raman Spectroscopy

By Carino Ferrante†‡?, Giovanni Batignani*†?, Emanuele Pontecorvo†?, Linda C. Montemiglio§, Marten H. Vos?, and Tullio Scopigno*†‡ from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b10560

[ASAP] Understanding the Electron-Doping Mechanism in Potassium-Intercalated Single-Walled Carbon Nanotubes

By Claudia Kro¨ckel†, Mari´a Rosa Preciado-Rivas‡, Victor Alexander Torres-Sa´nchez‡, Duncan J. Mowbray‡, Stephanie Reich§, Frank Hauke†, Julio C. Chaco´n-Torres*‡, and Andreas Hirsch*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11370

[ASAP] Direct Observation of the Reduction of Aryl Halides by a Photoexcited Perylene Diimide Radical Anion

By Charles J. Zeman, IV†?, Soojin Kim‡?, Fang Zhang*§, and Kirk S. Schanze*‡ from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b13027

[ASAP] Stereoelectronic and Resonance Effects on the Rate of Ring Opening of N-Cyclopropyl-Based Single Electron Transfer Probes

By Michelle L. Grimm, N. Kamrudin Suleman†, Amber N. Hancock‡, Jared N. Spencer§, Travis Dudding?, Rozhin Rowshanpour?, Neal Castagnoli, Jr., and James M. Tanko* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12617

[ASAP] Ir-Catalyzed Atroposelective Desymmetrization of Heterobiaryls: Hydroarylation of Vinyl Ethers and Bicycloalkenes

By Antonio Romero-Arenas†, Valenti´n Hornillos†§, Javier Iglesias-Sigu¨enza§, Rosario Ferna´ndez*§, Joaqui´n Lo´pez-Serrano*‡, Abel Ros*†§, and Jose´ M. Lassaletta*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12858

[ASAP] Chemo- and Regioselective Synthesis of Acyl-Cyclohexenes by a Tandem Acceptorless Dehydrogenation-[1,5]-Hydride Shift Cascade

By Lewis B. Smith, Roly J. Armstrong, Daniel Matheau-Raven, and Timothy J. Donohoe* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12296

[ASAP] Abiotic Mimic of Endogenous Tissue Inhibitors of Metalloproteinases: Engineering Synthetic Polymer Nanoparticles for Use as a Broad-Spectrum Metalloproteinase Inhibitor

By Masahiko Nakamoto, Di Zhao, Olivia Rose Benice, Shih-Hui Lee, and Kenneth J. Shea* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11481

[ASAP] A Model for the Emergence of RNA from a Prebiotically Plausible Mixture of Ribonucleotides, Arabinonucleotides, and 2'-Deoxynucleotides

By Seohyun Chris Kim†‡, Lijun Zhou†‡, Wen Zhang†‡, Derek K. O’Flaherty†‡§, Valeria Rondo-Brovetto†‡, and Jack W. Szostak*†‡ from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11239

[ASAP] Controlling the Nucleation and Growth Orientation of Nanocrystalline Carbon Films during Plasma-Assisted Deposition: A Reactive Molecular Dynamics/Monte Carlo Study

By Di Zhang†, Linfa Peng†, Xiaobo Li†, Peiyun Yi*†, and Xinmin Lai*†‡ from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12845

[ASAP] A Porous Covalent Organic Framework with Voided Square Grid Topology for Atmospheric Water Harvesting

By Ha L. Nguyen†‡, Nikita Hanikel†‡, Steven J. Lyle†, Chenhui Zhu§, Davide M. Proserpio??, and Omar M. Yaghi*†? from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b13094

[ASAP] Unusual Electrochemical Properties of Low-Doped Boron-Doped Diamond Electrodes Containing sp2 Carbon

By Jing Xu†, Yasuyuki Yokota‡, Raymond A. Wong‡, Yousoo Kim‡, and Yasuaki Einaga*†§ from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11183

[ASAP] Mechanically Gated Degradable Polymers

By Yangju Lin, Tatiana B. Kouznetsova, and Stephen L. Craig* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b13359

[ASAP] Conjugating Aptamer and Mitomycin C with Reductant-Responsive Linker Leading to Synergistically Enhanced Anticancer Effect

By Qiuxia Yang†?, Zhengyu Deng†?, Dan Wang†, Jiaxuan He†, Dailiang Zhang†, Yan Tan†, Tianhuan Peng†, Xue-Qiang Wang*†, and Weihong Tan*†‡§ from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12409

[ASAP] Reduced Recombination and Capacitor-like Charge Buildup in an Organic Heterojunction

By Kyra N. Schwarz†§, Paul B. Geraghty‡§, Valerie D. Mitchell‡§, Saeed-Uz-Zaman Khan?, Oskar J. Sandberg#, Nasim Zarrabi#, Bryan Kudisch†, Jegadesan Subbiah‡§, Trevor A. Smith§, Barry P. Rand??, Ardalan Armin#, Gregory D. Scholes*†§, David J. Jones‡§, and Kenneth P. Ghiggino*§ from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12526

[ASAP] Synthesis of Cyclobutane-Fused Tetracyclic Scaffolds via Visible-Light Photocatalysis for Building Molecular Complexity

By Martins S. Oderinde*†, Edna Mao†, Antonio Ramirez‡, Joseph Pawluczyk†, Christine Jorge§, Lyndon A. M. Cornelius†, James Kempson†, Muthalagu Vetrichelvan?, Manivel Pitchai?, Anuradha Gupta?, Arun Kumar Gupta?, Nicholas A. Meanwell†, Arvind Mathur†, and T. G. Murali Dhar*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12129

[ASAP] Host–Guest-Induced Electron Transfer Triggers Radical-Cation Catalysis

By Rebecca L. Spicer†, Athanasios D. Stergiou§, Tom A. Young‡, Fernanda Duarte*‡, Mark D. Symes*§, and Paul J. Lusby*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11273

[ASAP] A Polymer with “Locked” Degradability: Superior Backbone Stability and Accessible Degradability Enabled by Mechanophore Installation

By Tze-Gang Hsu†, Junfeng Zhou†, Hsin-Wei Su†, Briana R. Schrage‡, Christopher J. Ziegler‡, and Junpeng Wang*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 22, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12482

Tue 04 Feb 14:00: Mixing and cut-off for random walks on finite fields and random polynomials

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Mixing and cut-off for random walks on finite fields and random polynomials

I will report on joint work with Peter Varjú in which we investigate the ax+b random walk on a finite field F_p. Work from the 1990s by Chung-Diaconis-Graham established good upper bounds on mixing time when a=2. We refine their methods to understand the case when a is arbitrary in F_p. Using our previous work on irreducibility of polynomials of large degree, we obtain sharp bounds for the mixing time and prove, conditionally on the Generalized Riemann Hypothesis, that a sharp cut-off occurs.

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Approaching the Integer‐Charge Transfer Regime in Molecularly Doped Oligothiophenes by Efficient Decarboxylative Cross‐Coupling

By Jiang Tian Liu, Hannes Hase, Sarah Taylor, Ingo Salzmann, Pat Forgione from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

A library of symmetrical linear oligothiophene has been prepared employing decarboxylative cross‐coupling reaction as the key transformation. We utilized thiophene potassium carboxylate salts as cross‐coupling partners without the need of co‐catalyst, base, or additives. This method demonstrates complete chemoselectivity and is a comprehensive greener approach compared to the existing methodologies. The modularity of this approach is demonstrated with the preparation of discreet oligothiophenes with up to 10 thiophene repeat units. Symmetrical oligothiophenes represent prototypical organic semiconductors and allow us to spectroscopically assess their response to molecular electrical doping regarding the degree of charge transfer as a function of the chain length. We find evidence that the critical length for integer charge transfer as it is found in the polythiophene limit to be not more than 10 thiophene units, which highlights the potential of long discreet oligothiophenes for their use in organic electronic applications as doped conduction or injection layers.

Deconstructive Reorganization: De Novo Synthesis of Hydroxylated Benzofuran

By Shifa Zhu, Ling Zhang, Tongxiang Cao, Huanfeng Jiang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

An unprecedented deconstructive reorganization strategy for the de novo synthesis of hydroxylated benzofurans from kojic acid‐ or maltol‐derived alkynes is reported. In this reaction, both the benzene and furan rings were simultaneously constructed, whereas the pyrone moiety of the kojic acid or maltol was deconstructed and then reorganized into the benzene ring as a six‐carbon component. Through this strategy, at least one free hydroxyl group was introduced into the benzene ring in a substitution‐pattern tunable fashion without protection‐deprotection and redox adjustment. With this method, a large number of hydroxylated benzofuran derivatives with different substitution‐patterns have been prepared efficiently. This methodology has also been shown as the key step in a collective total synthesis of hydroxylated benzofuran‐containing natural products (11 examples).

Enantioselective Synthesis of 1,12‐Disubstituted [4]Helicenes

By Manuel Alcarazo, Thierry Hartung, Rafael Machleid, Martin Simon, Christopher Golz from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

A highly enantioselective synthesis of 1,12‐disubstituted [4]carbohelicenes is reported. Key for the synthetic route developed is a Au‐catalysed intramolecular alkyne hydroarylation step, which is achieved with good to excellent regio‐ and enantioselectivity levels employing TADDOL‐derived α‐cationic phosphonites as ancillary ligands. Moreover, an appropriate design of the substrate makes possible the assembling of [4]helicenes of different substitution patterns, thus demonstration the synthetic utility of the method. The absolute stereochemistry of the newly prepared structures was determined by X‐ray crystallography; their photophysical characterization is reported as well.

Molecular Fluorescence Imaging Spectroscopy for Mapping Low Concentrations of Red Lake Pigments: Van Gogh’s Painting The Olive Orchard

By Kathryn A. Dooley, Annalisa Chieli, Aldo Romani, Stijn Legrand, Costanza Miliani, Koen Janssens, John Delaney from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

Vincent van Gogh used fugitive red lake pigments that have faded in some paintings. Mapping their distribution is key to understanding how his paintings have changed with time. While red lake pigments can be identified from microsamples, in situ identification and mapping remains a challenge. This paper explores the ability of molecular fluorescence imaging spectroscopy to identify and, more importantly, map residual non‐degraded red lakes. The high sensitivity of this method enabled identification of the emission spectra of eosin (tetrabromine fluorescein) lake mixed with lead or zinc white at lower concentrations than elemental X‐ray fluorescence (XRF) spectroscopy used on account of bromine. The molecular fluorescence mapping of residual eosin and two carmine red lakes in van Gogh’s The Olive Orchard is demonstrated and compared with XRF imaging spectroscopy. The red lakes are consistent with the composition of paint tubes known to be used by van Gogh.

A Smart Autocatalytic DNAzyme Biocircuit for in vivo Amplified MicroRNA Imaging

By Jie Wei, Huimin Wang, Qiong Wu, Xue Gong, Kang Ma, Xiaoqing Liu, Fuan Wang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

DNAzymes have been recognized as promising transducing agents for visualizing endogenous biomarkers, while their inefficient intracellular delivery (including blunt responsibility) and limited amplification capacity (including insufficient cofactor supply) preclude their extensive biological applications. Here an exquisite autocatalytic DNAzyme (ACD) biocircuit is constructed for in vivo amplified microRNA imaging based on honeycomb MnO 2 nanosponge (hMNS)‐sustained hybridization chain reaction (HCR) and DNAzyme biocatalysis. The versatile hMNS scaffolds not only deliver DNA probes, but also supply appropriate Mn 2+ ‐DNAzyme cofactors and intelligent magnetic resonance imaging (MRI) agents into cancer cells. Through the subsequent synergistic cross‐activation between HCR and DNAzyme amplicons, the ACD amplifier turns the limited miRNA‐recognition into tremendously amplified readout, thus contributing to the accurate tumor diagnosis. As a robust sensing strategy, the intelligent autocatalytic amplifier realized the microRNA imaging in vivo, thus showing great promise in clinical theranostic.

Toward High‐Energy‐Density Lithium Metal Batteries: Opportunities and Challenges for Solid Organic Electrolytes

By Xiaoen Wang, Robert Kerr, Fangfang Chen, Nicolas Goujon, Jennifer M. Pringle, David Mecerreyes, Maria Forsyth, Patrick C. Howlett from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

High‐energy‐density and safe solid‐state lithium batteries are vital to advance today's consumer electronic and automobile applications. The advances in electromaterials research at Deakin University are summarized, with a focus on alternative solid electrolyte designs, including organic ionic plastic crystals, novel polymer electrolytes, and high capacity cathodes. Abstract With increasing demands for safe, high capacity energy storage to support personal electronics, newer devices such as unmanned aerial vehicles, as well as the commercialization of electric vehicles, current energy storage technologies are facing increased challenges. Although alternative batteries have been intensively investigated, lithium (Li) batteries are still recognized as the preferred energy storage solution for the consumer electronics markets and next generation automobiles. However, the commercialized Li batteries still have disadvantages, such as low capacities, potential safety issues, and unfavorable cycling life. Therefore, the design and development of electromaterials toward high‐energy‐density, long‐life‐span Li batteries with improved safety is a focus for researchers in the field of energy materials. Herein, recent advances in the development of novel organic electrolytes are summarized toward solid‐state Li batteries with higher energy density and improved safety. On the basis of new insights into ionic conduction and design principles of organic‐based solid‐state electrolytes, specific strategies toward developing these electrolytes for Li metal anodes, high‐energy‐density cathode materials (e.g., high voltage materials), as well as the optimization of cathode formulations are outlined. Finally, prospects for next generation solid‐state electrolytes are also proposed.

Plasmonic Elastic Capsules as Colorimetric Reversible pH‐Microsensors

By Céline Burel, Alexandre Teolis, Ahmed Alsayed, Christopher B. Murray, Bertrand Donnio, Rémi Dreyfus from Wiley: Small: Table of Contents. Published on Jan 21, 2020.

Plasmocapsules made of optically active plasmonic gold nanoparticles and pH‐responsive polyacrylate are used as pH microsensors. Upon pH change, the polymer shell of the plasmocapsules swells or shrinks. Concomitantly, the distance between the gold nanoparticles embedded in the polymeric matrix varies, resulting in a color change. Each single plasmocapsule is a reversible independent microsensor over a large range of pH. Abstract There is a crucial need for effective and easily dispersible colloidal microsensors able to detect local pH changes before irreversible damages caused by demineralization, corrosion, or biofilms occur. One class of such microsensors is based on molecular dyes encapsulated or dispersed either in polymer matrices or in liquid systems exhibiting different colors upon pH variations. They are efficient but often rely on sophisticated and costly syntheses, and present significant risks of leakage and photobleaching damages, which is detrimental for mainstream applications. Another approach consists of exploiting the distance‐dependent plasmonic properties of metallic nanoparticles. Still, assembling nanoparticles into dispersible colloidal pH‐sensitive sensors remains a challenge. Here, it is shown how to combine optically active plasmonic gold nanoparticles and pH‐responsive thin shells into “plasmocapsules.” Upon pH change, plasmocapsules swell or shrink. Concomitantly, the distance between the gold nanoparticles embedded in the polymeric matrix varies, resulting in an unambiguous color change. Billions of micron‐size sensors can thus be easily fabricated. They are nonintrusive, reusable, and sense local pH changes. Each plasmocapsule is an independent reversible microsensor over a large pH range. Finally, their potential use for the detection of bacterial growth is demonstrated, thus proving that plasmocapsules are a new class of sensing materials.

In Vitro Light‐Up Visualization of Subunit‐Specific Enzyme by an AIE Probe via Restriction of Single Molecular Motion

By Tienan Zang, Yachen Xie, Sa Su, Qianqian Chen, Feiran Liu, Jing Jing, Rubo Zhang, Guangle Niu, Xiaoling Zhang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

Generally, enzymes contain several subunits to maintain different biological functions in live systems. However, it still remains a great challenge for specific discrimination of one subunit over another. Toward this end, we present the first fluorescent probe TPEMA for highly specific detection of B subunit of cytosolic creatine (CK) kinase isoenzyme (CK‐B). Due to its aggregation‐induced emission property, TPEMA shows highly boosted emission toward CK‐B with fast response time and very low interference from other analytes including M subunit of CK (CK‐M). With the aid of Job's plot assay, ITC assay and molecular dynamics simulation, for the first time we directly confirmed that the remarkably enhanced fluorescence of TPEMA in the presence of CK‐B results from the restriction of single molecular motion in the cavity. Selective wash‐free fluorescence imaging of CK‐B in macrophages under different treatments was successfully demonstrated. This work can shed much light on future fluorescent probes for light‐up detection of other subunit‐specific enzymes.

Bioinspired Artificial Tobacco Mosaic Virus with Combined Oncolytic Properties to Completely Destroy Multidrug‐Resistant Cancer

By Huayu Wu, Dan Zhong, Zhijun Zhang, Yachao Li, Xiao Zhang, Yunkun Li, Zhuangzhuang Zhang, Xianghui Xu, Jun Yang, Zhongwei Gu from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Artificial tobacco mosaic virus (ATMV), which highly mimicks both the typical elongated structure and biobehavior of natural TMVs, is ingeniously endowed with robust oncolytic properties, achieving composite therapies to completely defeat large‐sized drug‐resistant colon tumors. This work provides broad possibilities for novel virus‐like strategies that optimize the morphological features of versatile oncolytic functions to address complicated cancer environments. Abstract Although biomimetic virus‐like strategies have been widely used in antitumor applications, construction of uniquely shaped virus‐like agents and optimization of their specific morphological features to achieve diverse antitumor functions are worthwhile pursuits. Here, a novel strategy to construct an artificial tobacco mosaic virus (ATMV) that closely mimics the structure of the rod‐like tobacco mosaic virus (TMV) is developed. The supramolecular array is self‐assembled from small, repeated subunits of tailor‐made capsid‐mimicking dendrons onto RGD‐modified single‐walled carbon nanotube to construct the ATMVs with high structural stability. The ATMVs are tactfully designed with shielding, targeting, and arming approaches, including shielding the viruses against premature elimination, selectively targeting tumor tissue, and arming the viruses with oncolytic abilities. The elongated particles are concealed in blood until they arrived at a tumor site, then they induce robust composite oncolytic processes including cytomembrane penetration, endoplasmic reticulum disruption to cause Ca2+ release, chemotherapeutic delivery, and photothermal therapy. Excitingly, the ATMVs not only lyse primary infected cells, but permeate adjacent cells for secondary infection, spreading cell‐to‐cell and continuing to induce lysis even deep in solid tumors. This work inspires a uniquely shaped virus‐like agent with tactically optimized oncolytic functions that completely defeated large drug‐resistant colon tumor (LoVo/Adr, ≈500 mm3).

An Excitation Navigating Energy Migration of Lanthanide Ions in Upconversion Nanoparticles

By Zhendong Lei, Xiao Ling, Qingsong Mei, Shuai Fu, Jing Zhang, Yong Zhang from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Energy migration of a single lanthanide activator ion in a novel dumbbell‐shaped upconversion nanoparticle is navigated along favored electronic transitions pathway at specific excitation wavelengths, resulting in orthogonal emission properties. Such specially designed nanoparticles are further explored for simultaneous imaging latent fingerprint and analysis of trace amounts of explosive residues in fingerprint. Abstract Upconversion nanoparticles (UCNPs) doped with lanthanide ions that possess ladder‐like energy levels can give out multiple emissions at specific ultra‐violet or visible wavelengths irrespective of excitation light. However, precisely controlling energy migration processes between different energy levels of the same lanthanide ion to generate switchable emissions remains elusive. Herein, a novel dumbbell‐shaped UCNP is reported with upconverted red emission switched to green emission when excitation wavelength changed from 980 to 808 nm. The sensitizer Yb ions are doped with activator Er ions and energy modulator Mn ions in NaYF4 core nanocrystal coated with an inner NaYF4:Yb shell to generate red emission after harvesting 980 nm excitation light, while an outer NaNdF4:Yb shell is coated to form a dumbbell shape to generate green emission upon 808 nm excitation. Such specially designed UCNPs with switchable green and red emissions are further explored for imaging of latent fingerprint and detection of explosive residues in the fingerprint simultaneously. This work suggests a novel research interest in fine‐tuning of upconversion emissions through precisely controlling energy migration processes of the same lanthanide activator ion. Furthermore, use of these nanoparticles in other applications such as simultaneous dual‐color imaging or orthogonal bidirectional photoactivation can be explored.

Anti‐aromatic vs. induced paratropicity: synthesis and interrogation of a dihydro‐diazatrioxa[9]circulene with a proton placed directly above the central ring

By Michael Pittelkow, Stephan K. Pedersen, Kristina Eriksen, Nataliya N. Karaush-Karmazin, Boris Minaev, Hans Ågren, Gleb V. Baryshnikov from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

We present a high yielding intramolecular oxidative coupling within a diazadioxa[10]helicene to give a dihydro‐diazatrioxa[9]circulene. This is the first [n]circulene containing more the eight ortho annulated rings (n>8). The single crystal X‐ray structure reveals a tight columnar packing, with a proton from a pendant naphthalene moiety centred directly above the central 9‐membered ring. This distinct environment induces a significant magnetic deshielding effect on that particular proton as determined by 1 H‐NMR spectroscopy. The origin of the deshielding effect is investigated computationally by NICS values. It is established that the deshielding effect originates from an induced paratropic ring current from the seven aromatic rings of the [9]circulene structure, and not due to the nine‐membered ring being antiaromatic. UV/vis spectroscopy reveals efficient conjugation in the prepared diazatrioxa[9]circulene compared to the parent helical azaoxa[10]helicenes, and DFT calculations, including energy levels, confirm the experimental observations.

Parathyroid Hormone Derivative with Reduced Osteoclastic Activity Promoted Bone Regeneration via Synergistic Bone Remodeling and Angiogenesis

By Jinghuan Huang, Dan Lin, Zhanying Wei, Qi Li, Jin Zheng, Qixin Zheng, Lin Cai, Xiaolin Li, Yuan Yuan, Jingfeng Li from Wiley: Small: Table of Contents. Published on Jan 21, 2020.

Parathyroid hormone (PTH) is a potential bone repair agent, but its application is limited due to overwhelming osteoclastic activity. PTHrP‐2 is created by structural modification and shows controlled release characteristics, enhanced pro‐osteogenic and proangiogenic properties. Surprisingly, the modification of PTH reduces its pro‐osteoclastic properties. Therefore, PTHrP‐2 can be used in local bone repair and extends the application scope of PTH. Abstract Osteogenesis, osteoclastogenesis, and angiogenesis are the most important processes in bone repair. Parathyroid hormone (PTH) has pro‐osteogenic, pro‐osteoclastogenic, and proangiogenic effects and may be a candidate for use in bone defect repair. However, the local application of PTH to bone defects is counterproductive due to its excessive osteoclastic and bone resorptive effects. In this study, a PTH derivative, PTHrP‐2, is developed that can be applied to local bone defects. First, a modified peptide with a calcium‐binding repeat glutamine tail undergoes controlled local release from a ceramic material and is shown to be a better fit for the repair process than the unmodified peptide. Second, the modified peptide is shown to have strong pro‐osteogenic activity due to mineralization and its facilitation of serine (Ser) phosphorylation. Third, the modified peptide is shown to maintain the pro‐osteoclastogenic and proangiogenic properties of the unmodified peptide, but its pro‐osteoclastogenic activity is reduced compared to that of the unmodified peptide. The reduced pro‐osteoclastogenic and increased pro‐osteogenic properties of the modified peptide reverse the imbalance between osteoblasts and osteoclasts with local PTH application and shift bone resorption to bone regeneration.

Li/Garnet Interface Stabilization by Thermal‐decomposition Vapor Deposition of an Amorphous Carbon Layer

By Wuliang Feng, Xiaoli Dong, Xiang Zhang, Zhengzhe Lai, Panlong Li, Congxiao Wang, Yonggang Wang, Yongyao Xia from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

Applying interlayers is the main strategy to address the large area specific resistance (ASR) of Li/garnet interface. However, studies on eliminating the Li 2 CO 3 and LiOH interfacial lithiophobic contaminants are still insufficient. Here, we propose thermal‐decomposition vapor deposition (TVD) of a carbon modification layer on Li 6.75 La 3 Zr 1.75 Ta 0.25 O 12 (LLZTO), which provides a contaminant‐free surface. Due to the protection of the carbon layer, the air stability of LLZTO is also improved. Moreover, owing to the amorphous structure of the low graphitized carbon (LGC), instant lithiation is achieved, and the ASR of the Li/LLZTO interface is reduced to 9 Ω cm 2 . Lithium volatilization and Zr 4+ reduction are also controllable during TVD. Compared with its high graphitized carbon counterpart (HGC), the LGC‐modified Li/LLZTO interface displays a higher critical current density of 1.2 mA/cm 2 , as well as moderate Li plating and stripping, which provides enhanced polarization voltage stability.

Variable‐Wavelength Quick Scanning Nanofocused X‐Ray Microscopy for In Situ Strain and Tilt Mapping

By Marie‐Ingrid Richard, Thomas W. Cornelius, Florian Lauraux, Jean‐Baptiste Molin, Christoph Kirchlechner, Steven J. Leake, Jérôme Carnis, Tobias U. Schülli, Ludovic Thilly, Olivier Thomas from Wiley: Small: Table of Contents. Published on Jan 21, 2020.

Variable‐wavelength quick scanning X‐ray microscopy is demonstrated to be a new in situ tool that provides access both to the rotation of the crystalline lattice and to the strain field inside micro‐ and nanostructures under mechanical load. It offers new opportunities to study the mechanical behavior at small scales in situ as well as in heavy and complex environments. Abstract Compression of micropillars is followed in situ by a quick nanofocused X‐ray scanning microscopy technique combined with 3D reciprocal space mapping. Compared to other attempts using X‐ray nanobeams, it avoids any motion or vibration that would lead to a destruction of the sample. The technique consists of scanning both the energy of the incident nanofocused X‐ray beam and the in‐plane translations of the focusing optics along the X‐ray beam. Here, the approach by imaging the strain and lattice orientation of Si micropillars and their pedestals during in situ compression is demonstrated. Varying the energy of the incident beam instead of rocking the sample and mapping the focusing optics instead of moving the sample supplies a vibration‐free measurement of the reciprocal space maps without removal of the mechanical load. The maps of strain and lattice orientation are in good agreement with the ones recorded by ordinary rocking‐curve scans. Variable‐wavelength quick scanning X‐ray microscopy opens the route for in situ strain and tilt mapping toward more diverse and complex materials environments, especially where sample manipulation is difficult.

Binary Chiral Nanoparticles Exhibit Amplified Optical Activity and Enhanced Refractive Index Sensitivity

By Lin Yang, Proloy Nandi, Yicong Ma, Junjun Liu, Utkur Mirsaidov, Zhifeng Huang from Wiley: Small: Table of Contents. Published on Jan 21, 2020.

The host chiral nanoparticles (CNPs) are alloyed with metals, induced by physical vapor deposition‐caused heating effect, to generate binary CNPs. The alloying not only induces the plasmonic optical activity (OA) of the dopant metals and the created alloys, but also causes the host to amplify in the plasmonic OA and enhances the refractive index sensitivity. Abstract Metallic chiral nanoparticles (CNPs) with a nominal helical pitch (P) of sub‐10 nm contain inherent chirality and are promisingly applied to diverse prominent enantiomer‐related applications. However, the sub‐wavelength P physically results in weak optical activity (OA) to prohibit the development of these applications. Herein, a facile method to amplify the CNPs' OA by alloying the host CNPs with metals through a three‐step layer‐by‐layer glancing angle deposition (GLAD) method is devised. Promoted by the GLAD‐induced heating effect, the solute metallic atoms diffuse into the host CNPs to create binary alloy CNPs. Chiral alloying not only induces the plasmonic OA of the diffused solute and the created alloys but also amplifies that of the host CNPs, generally occurring for alloying Ag CNPs with diverse metals (including Cu, Au, Al, and Fe) and alloying Cu CNPs with Ag. Furthermore, the chiral alloying leads to an enhancement of refractive index sensitivity of the CNPs. The alloy CNPs with amplified plasmonic OA pave the way for potentially developing important chirality‐related applications in the fields of heterogeneous asymmetric catalysis, enantiodifferentiation, enantioseparation, biosensing, and bioimaging.

Biomedical Applications of Calixarenes: State‐of‐the‐Art and Perspectives

By Yu-Chen Pan, Xin-Yue Hu, Dong-Sheng Guo from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

Calixarenes (CAs), representing the third generation of supramolecular hosts and one of the most widely studied macrocyclic scaffolds, offer (almost) unlimited possibilities due to their ease of modification, which allows one to establish a large molecular library as a material basis for diverse biomedical applications. Moreover, CAs and their derivatives engage in various non‐covalent interactions for the facile recognition of guests including bioactive molecules and are also important building blocks for the fabrication of supramolecular architectures. In view of their molecular recognition and self‐assembly properties, CAs are extensively applied in biosensing, bioimaging, and drug/gene delivery. Additionally, some CA derivatives exhibit biological activities and can therefore be used as new therapeutic agents. Herein, we summarize the diverse biomedical applications of CAs including in‐vitro diagnosis (biosensing), in‐vivo diagnosis (bioimaging), and therapy.

Unveiling the Activity Origin of Copper‐based Electrocatalyst for Selective Nitrate Reduction to Ammonia

By Yuting Wang, Wei Zhou, Ranran Jia, Yifu Yu, Bin Zhang from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

Unveiling the active phase of catalytic materials under reaction conditions is important for the designed construction of efficient electrocatalysts for selective nitrate reduction to ammonia. Here, we probed the origin of the prominent activity enhancement for CuO (Faradaic efficiency: 95.8%, Selectivity: 81.2%) toward selective nitrate electroreduction to ammonia. 15 N isotope labeling experiments proved that ammonia originated from nitrate reduction. Both the 1 H nuclear magnetic resonance (NMR) spectra and colorimetric methods were performed to quantify ammonia. In situ Raman and ex situ experiments revealed that CuO was electrochemically converted into Cu/Cu 2 O, which serves as an active phase. The combined results of online differential electrochemical mass spectrometry (DEMS) and density functional theory (DFT) calculations demonstrated that the electron transfer from Cu 2 O to Cu at the interface could facilitate the formation of * NOH intermediate and suppress the hydrogen evolution reaction, leading to high selectivity and Faradaic efficiency.

Synthesis of a hemispherical geodesic phenine framework via a polygon assembling strategy

By Tatsuru Mio, Koki Ikemoto, Sota Sato, Hiroyuki Isobe from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

A synthetic strategy to construct large geodesic structures of phenine (1,3,5‐trisubstituted benzene) was devised. The strategy assembled five pentagons on an omphalos pentagon and, bridging peripheral pentagons, furnished five additional hexagons. Thirty phenine units were synthetically assembled to afford a large C 220 H 180 molecule having a phenine framework isoreticular to a hemispherical, bisected segment of C 60 . Although a hemispherical structure of the phenine framework was suggested by solution‐phase NMR spectra, the crystallographic analysis revealed an ovally deformed structure of the molecule. In‐depth structural analyses including theoretical calculations showed that fluctuations at biaryl torsions allowed for the structural deformations and, at the same time, that the dynamic fluctuations resulted in the spectroscopic observation of the hemispherical structure as a time‐averaged structure.

Enantioselective Total Synthesis of Macfarlandin C, a Spongian Diterpenoid Harboring a Concave‐Substituted cis‐Dioxabicyclo[3.3.0]octanone Fragment

By Larry E. Overman, Tyler K. Allred, André P. Dieskau, Peng Zhao, Gregory L. Lackner from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

The enantioselective total synthesis of the rearranged spongian diterpenoid (–)‐macfarlandin C is reported. This is the first synthesis of a rearranged spongian diterpenoid in which the bulky hydrocarbon fragment is joined via a quaternary carbon to the highly hindered concave face of the cis‐2,8‐dioxabicyclo[3.3.0]octan‐3‐one moiety. The strategy involves a late‐stage fragment coupling between a tertiary carbon radical and an electrophilic butenolide resulting in the stereoselective formation of vicinal quaternary and tertiary stereocenters. A stereoselective Mukaiyama hydration that orients a pendant carboxymethyl side chain cis to the bulky octahydronapthalene substituent was pivotal in fashioning the challenging concave‐substituted cis‐dioxabicyclo[3.3.0]octanone fragment.

Wed 04 Mar 16:00: Trisections and the Thom conjecture

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Trisections and the Thom conjecture

The classical degree-genus formula computes the genus of a nonsingular algebraic curve in the complex projective plane. The well-known Thom conjecture posits that this is a lower bound on the genus of smoothly embedded, oriented and connected surface in CP^2. The conjecture was first proved twenty-five years ago by Kronheimer and Mrowka, using Seiberg-Witten invariants. In this talk, we will describe a new proof of the conjecture that combines contact geometry with the novel theory of bridge trisections of knotted surfaces. Notably, the proof completely avoids any gauge theory or pseudoholomorphic curve techniques.

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Thu 12 Mar 14:30: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Title to be confirmed

Abstract not available

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Thu 06 Feb 14:30: Graphs with forbidden induced subgraphs

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Graphs with forbidden induced subgraphs

Ramsey’s Theorem tells us that every graph on n vertices contains a complete subgraph or independent set of size about log n. Considering random graphs shows that this is all we can expect: for most graphs, the largest complete subgraph or independent set has size O(log n). But what if we consider graphs G that do not contain some specific induced subgraph H? Erdos and Hajnal conjectured in the 1980s that in this case G must have a complete subgraph or independent set of size at least |G|^c, for some c=c(H). The Erdos-Hajnal conjecture remains open, but we will discuss some recent progress and related results. This talk includes joint work with Maria Chudnovsky, Jacob Fox, Paul Seymour and Sophie Spirkl.

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Thu 30 Jan 14:30: Inequalities on projected volumes

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Inequalities on projected volumes

Given $2n – 1$ real numbers $x_A$ indexed by the non-empty subsets $A \subset \{ 1,\ldots,n \}$, is it possible to construct a body $T$ in $Rn$ such that $x_A = \| T_A \|$, where $\| T_A \|$ is the $\| A \|$-dimensional volume of the projection of $T$ onto the subspace spanned by the axes of $A$? As it is more convenient to take logarithms, we denote by $\psi_n$ the set of all vectors $x$ for which there is a body $T$ such that $x_A = \log \| T_A \|$ for all $A$. Bollob\’as and Thomason showed that $\psi_n$ is containd in the polyhedral cone defined by the class of `uniform cover inequalities’. Tao and Zeng conjectured that the convex hull of $\psi_n$ is equal to the cone given by the uniform cover inequalities.

We show that this conjecture is not right, but is `nearly’ right.

Joint work with Imre Leader and Eero Raty.

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Wed 29 Jan 16:00: Tribalism in War and Peace: The nature and evolution of ideological epistemology and its significance for modern social science

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Tribalism in War and Peace: The nature and evolution of ideological epistemology and its significance for modern social science

Because of a long history of intergroup conflict, humans evolved to be tribal. These tribal tendencies can lead individuals to sacrifice sound reasoning and judgmental accuracy in order to conform to and defend the views of their ingroup. Political tribes are one of the most salient forms of modern tribal identity, and so politics likely triggers these tribal tendencies, leading to ideologically distorted information processing. My work has shown that these ideological biases exist in similar degrees in liberals and conservatives, but certain sacred concerns can lead to stronger biases in one group than in the other. Liberals have sacred concerns about traditionally conceived disadvantaged groups, and thus liberals are more biased than conservatives when evaluating information with significance to such groups. And because social scientists are overwhelmingly liberal, these sacred concerns may have biased and may continue to bias the conclusions drawn by social scientists.

Cory Clark received her PhD in Social Psychology from University of California, Irvine in 2014, and she is currently an Assistant Professor of Social Psychology at Durham University. She has two main programs of research, examining (1) how punitive desires shape beliefs about human agency and moral responsibility, and (2) how political biases influence evaluations of science. She also co-hosts a podcast, Psyphilopod, which covers psychology, philosophy, politics, and academic culture.

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Thu 26 Mar 18:45: A trillion trees – A trillion reasons to thrive!

From All Talks (aka the CURE list). Published on Jan 21, 2020.

A trillion trees – A trillion reasons to thrive!

Stuart Dainton , will introduce this international project and explain that it is not just about planting trees but that their vision is to see one trillion trees re-grown, saved from loss and better protected around the world by 2050. He will talk about how this worldwide collaborative project aims to do this and to work towards a world where people and nature can thrive.

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Thu 21 May 14:15: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Title to be confirmed

Abstract not available

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Thu 06 Feb 16:00: Field emitters at atomic scale: Insights from density functional theory

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Field emitters at atomic scale: Insights from density functional theory

Abstract not available

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Wed 18 Nov 15:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Title to be confirmed

Abstract not available

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Wed 21 Oct 15:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Title to be confirmed

Abstract not available

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Wed 07 Oct 15:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Title to be confirmed

Abstract not available

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Wed 24 Jun 15:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Title to be confirmed

Abstract not available

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Thu 30 Jan 15:30: Pick your poison: insecticides and locust control in colonial Kenya

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Pick your poison: insecticides and locust control in colonial Kenya

Literature on the use of insecticides in the tropics after 1945 is preoccupied with the WHO ’s Malaria Eradication Programme. This scholarship describes a form of technological hubris in which scientists rushed to deploy the quick fix of DDT on the widest possible scale, fuelled by belief in the power of Western science and buoyed by Allied victory. This paper focuses on trials to control locusts in Kenya after 1945 using synthetic insecticides to tell a different story. It shows that approaches to the use of new synthetic insecticides in Britain’s African colonies were often informed by debate about the relative costs of different locust control measures. This reflected the weaker economic position of Britain in comparison to the USA , backers of the WHO programme, but more importantly, regimes of locust control that used substances such as gammexane were evaluated in Kenya against pre-existing methods. In other words, the notion that DDT and related chemicals were wonder weapons of such power that they marked a radical departure from past measures, and quickly rendered all previous insect control methods obsolete, is not borne out by this study. The use of the new insecticides was dependent upon calculations of advantage versus cost in comparison to well-established existing methods. In addition, previous experience with arsenic bait and pyrethrum shaped the testing and deployment of gammexane in significant ways, including evaluation of its toxicity. The perception of the new chemicals as part of a continuum of poisons also informed the attitudes of Kenyan herdsmen. Their suspicion of gammexane was not merely the result of a distrust of Western science and the colonial government, but arose directly from the experience of seeing their cattle poisoned by arsenic bait during the interwar years.

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Thu 06 Feb 15:30: On pluralism in psychiatry

From All Talks (aka the CURE list). Published on Jan 21, 2020.

On pluralism in psychiatry

I have argued that pluralism about methods and/or theories is good for science, because it can increase empirical success, but bad for scientific authority, because it hinders consensus. Psychiatry has been dominated by a single conceptual framework for the last forty years (the DSM framework) and enjoyed considerable professional authority. Because of the ‘crisis of validity’, this dominance has recently given way to a pluralist situation in which several different approaches to disease nosology are being developed. In addition to the DSM framework, there is the RDoC program, the network approach, the mechanistic property cluster approach, and others. My paper will explore the challenges and difficulties of working with pluralism in psychiatry, making constructive suggestions for future research.

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Thu 20 Feb 15:30: The case for modelled democracy

From All Talks (aka the CURE list). Published on Jan 21, 2020.

The case for modelled democracy

The fact that most of us are ignorant on politically relevant matters presents a problem for democracy. In light of this, some have suggested that we impose epistemic constraints on democratic participation, and specifically that the franchise be restricted along competency lines – a suggestion that in turn runs the risk of violating a long-standing condition on political legitimacy to the effect that legitimate political arrangements cannot be open to reasonable objections. In this talk, I outline a way to solve the problem of public ignorance without restricting the franchise. The proposal involves filtering the electoral input of a universal franchise through a statistical model that simulates what the public’s political preferences would be, were it informed on politically relevant matters. The result is modelled democracy. I make the case that such democracy both solves the problem of public ignorance and satisfies the aforementioned condition on legitimacy.

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Thu 27 Feb 15:30: 'I am rhapsodic man': Alexander von Humboldt in search of himself

From All Talks (aka the CURE list). Published on Jan 21, 2020.

'I am rhapsodic man': Alexander von Humboldt in search of himself

In recent years, Alexander von Humboldt (1769–1859) has resurfaced as a heroic, public figure. Popular accounts and new text editions suggest that the Prussian-born scholar is one of us in the 21st century: ecological in his thinking, democratic in his beliefs, and far ahead of his own epoch. In contrast, Andreas Daum calls for carefully historicizing Humboldt. Based on an ongoing biographical project, his talk will concentrate on the 1790s, when the young Humboldt pursued widespread research interests and simultaneously tried to reconcile his divergent passions. Rather than navigating on a straightforward course toward his American journey and a future era, Humboldt became entangled in the uncertainties of the revolutionary times that surrounded him. He embarked on a rhapsodic search of himself as a mensch, researcher and friend to his male companions.

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Thu 05 Mar 15:30: Postcolonial blood infrastructures of hepatitis B (a view from West Africa)

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Postcolonial blood infrastructures of hepatitis B (a view from West Africa)

The development of serological markers for hepatitis B infection kindled a rush, beginning in the late 1960s, for West African blood (as well as liver tissues). These tissues were processed – mostly or in part in the US and France – to generate evidence of an aetiological link between persistent viral infection and cirrhotic/cancerousliver damage; to map out patterns of viral circulation; and to evaluate the efficacy of the first human blood-derived hepatitis B vaccines. The exchange of blood (and liver bits) as research material was, from the outset, coproduced with modes and moments of viral contact among bloodstreams, as well as the prospect and practice of modulating immunities by relocating antigens between bodies. By speaking of ‘blood infrastructures’, I want to draw attention not only to the material underpinnings (and economies) of research on, exposure to and immunization against hepatitis B in the 1970s–1980s – including in Mali, Senegal and The Gambia – but also to explore how their respective stakes, interactions and geographies were entangled. These entanglements, I suggest, illuminate key postcolonial dimensions of, and thus persisting inequalities in, hepatitis B knowledge and antibody production.

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Thu 23 Apr 15:30: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Title to be confirmed

Abstract not available

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Thu 30 Apr 15:30: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Title to be confirmed

Abstract not available

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Thu 07 May 15:30: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Thu 21 May 15:30: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Title to be confirmed

Abstract not available

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Wed 13 May 15:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Title to be confirmed

Abstract not available

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Wed 10 Jun 15:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Title to be confirmed

Abstract not available

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Wed 11 Mar 15:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Title to be confirmed

Abstract not available

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Wed 12 Feb 15:00: Arterial redox signalling in the control of bood pressure under inflammatory conditions

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Arterial redox signalling in the control of bood pressure under inflammatory conditions

Under inflammatory conditions, the haem-containing indoleamine 2,3-dioxygenase 1 is expressed in arterial endothelial cells. In the presence of hydrogen peroxide, the endothelial enzyme generates 1O2 and that this is associated with the stereoselective oxidation of L-tryptophan to a tricyclic hydroperoxide via a previously unrecognized oxidative activation of the dioxygenase activity. The tryptophan-derived hydroperoxide acts in vivo as a signalling molecule, inducing arterial relaxation and decreasing blood pressure; this activity is dependent on Cys42 of protein kinase G1α. Our findings demonstrate a pathophysiological role for singlet oxygen in mammals through formation of an amino acid-derived hydroperoxide that regulates vascular tone and blood pressure under inflammatory conditions.

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Materials Science at Nankai: A Special Issue Dedicated to the 100th Anniversary of Nankai University

By Jialiang Xu, Fangyi Cheng, Xian‐He Bu, Jun Chen from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Masthead: (Adv. Mater. 3/2020)

By from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Contents: (Adv. Mater. 3/2020)

By from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Integrated Optoelectronics: Integrated Perovskite/Bulk‐Heterojunction Organic Solar Cells (Adv. Mater. 3/2020)

By Yongsheng Liu, Yongsheng Chen from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

In article number 1805843, Yongsheng Chen and Yongsheng Liu review integrated perovskite/bulk‐heterojunction (BHJ) organic solar cells (IPOSCs), which have recently emerged, and which could take the advantage of tandem cells using both perovskite and near‐infrared organic materials for wide‐range sunlight absorption. Combined with the reserved high open‐circuit voltage (VOC), efficiencies close to or even exceeding the Shockley–Queisser limit of single‐junction cells are expected.

Nanoadditive Manufacturing: Self‐Limiting Assembly Approaches for Nanoadditive Manufacturing of Electronic Thin Films and Devices (Adv. Mater. 3/2020)

By Zhao Wang, Yu Kang, Sanchuan Zhao, Jian Zhu from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Nanoadditive manufacturing, a promising solution‐based technique for the precise control of electronic film growth and device fabrication, is summarized by Jian Zhu and co‐workers in article number 1806480. The focus is particularly on the approaches of Langmuir–Blodgett assembly and layer‐by‐layer assembly, with a summary of manufactured thin‐film conductors, semiconductors, and dielectrics, and their applications in various electronics.

Metasurfaces: Metasurface‐Empowered Optical Multiplexing and Multifunction (Adv. Mater. 3/2020)

By Shuqi Chen, Wenwei Liu, Zhancheng Li, Hua Cheng, Jianguo Tian from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

In article number 1805912, Shuqi Chen and co‐workers present the development of multiplexing and multifunctional metasurfaces, which enable concurrent tasks through a dramatic compact design. The fundamental properties, design strategies, and applications of multiplexing and multifunctional metasurfaces are discussed. With the development of deep sub‐wavelength nanostructures, such multiplexing and multifunctional metasurfaces will have a deeper and deeper impact on modern photonics, quantum optics, and related techniques.

Printed Wearable Electronics: Recent Development of Printed Micro‐Supercapacitors: Printable Materials, Printing Technologies, and Perspectives (Adv. Mater. 3/2020)

By Hongpeng Li, Jiajie Liang from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

In article number 1805864, Jiajie Liang and Hongpeng Li review the recent progress in the preparation of functional ink systems for printed and wearable micro‐supercapacitors (MSCs), encompassing electrode materials, conductor materials, and electrolytes. Various issues that hinder the full materialization of widespread adoption of printed MSCs, the next steps to overcome these issues, and an in‐depth analysis of further scientific and technical challenges are also discussed.

Nankai University (Adv. Mater. 3/2020)

By from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Nankai University is a historical and prominent university in China. It was established in 1919 by the two famous patriotic educators, Mr. Xiu Yan and Boling Zhang, since when Nankai has become one of China's leading universities. It is a key comprehensive and research‐oriented university with the widest range of disciplines, featuring a perfect balance between the humanities and the sciences.

Nankai University (Adv. Mater. 3/2020)

By from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

This special issue presents a snapshot of work carried out by the faculty members from different colleges of Nankai University, to celebrate its 100th Anniversary. A broad spectrum of cutting‐edge research into advanced materials is covered, showcasing the research efforts and advances at the interface between materials science and chemistry, physics, life sciences, on the campus at Nankai University.

Nonlinear Optical Perovskites: Halide Perovskites for Nonlinear Optics (Adv. Mater. 3/2020)

By Jialiang Xu, Xinyue Li, Jianbo Xiong, Chunqing Yuan, Sergey Semin, Theo Rasing, Xian‐He Bu from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Halide perovskites are a promising platform for the construction of nonlinear optical materials in light of their structural diversity, high hyperpolarizability, and bandgap tunability. In article number 1806736, Jialiang Xu, Xian‐He Bu, and co‐workers review the current state of the art in purely inorganic and in organic–inorganic‐hybrid halide perovskites as nonlinear optical materials and discuss their potential for various nonlinear photonic applications.

DNA Hydrogels and Microgels for Biosensing and Biomedical Applications

By Fengyun Li, Danya Lyu, Shuo Liu, Weiwei Guo from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Smart DNA hydrogels and microgels are promising materials for biosensing and biomedical applications because of the specific molecular recognition capability, high‐precision assembly, programmable functions, and excellent biocompatibility of functional DNA. Recent progress in the development and applications of smart DNA hydrogels and microgels is summarized and current challenges and future prospects are discussed. Abstract DNA hydrogels, which take advantage of the unique properties of functional DNA motifs, such as specific molecular recognition, programmable and high‐precision assembly, multifunctionality, and excellent biocompatibility, have attracted increasing research interest in the past two decades in diverse fields, especially in biosensing and biomedical applications. The responsiveness of smart DNA hydrogels to external stimuli by changing their swelling volume, crosslinking density, and optical or mechanical properties has facilitated the development of DNA‐hydrogel‐based in vitro biosensing systems and actuators. Furthermore, reducing the sizes of DNA hydrogels to the micro‐ and nanoscale leads to better responsiveness and delivery capacity, thereby making them excellent candidates for rapid detection, in vivo real‐time sensing, and drug release applications. Here, the recent progress in the development of smart DNA hydrogels and DNA microgels for biosensing and biomedical applications is summarized, and the current challenges as well as future prospects are also discussed.

Tailorable Dynamics in Nonlinear Optical Metasurfaces

By Mengxin Ren, Wei Cai, Jingjun Xu from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Finding a material with tailorable nonlinearities would be a major breakthrough in nonlinear optics, which in turn promises a bright future for developing multifunctional nonlinear optical devices based on monolithic material frameworks. Recent progress in tailorable nonlinear optical dynamics in metasurfaces is reviewed, and the development trends of nonlinear metasurfaces for weak‐light nonlinear photonics and devices are explored. Abstract Controlling light with light is essential for all‐optical switching, data processing in optical communications and computing. Until now, all‐optical control of light has relied almost exclusively on nonlinear optical interactions in materials. Achieving giant nonlinearities under low light intensity is essential for weak‐light nonlinear optics. In the past decades, such weak‐light nonlinear phenomena have been demonstrated in photorefractive and photochromic materials. However, their bulky size and slow speed have hindered practical applications. Metasurfaces, which enhance light–matter interactions at the nanoscale, provide a new framework with tailorable nonlinearities for weak‐light nonlinear dynamics. Current advances in nonlinear metasurfaces are introduced, with a special emphasis on all‐optical light controls. The tuning of the nonlinearity values using metasurfaces, including enhancement and sign reversal is presented. The tailoring of the transient behaviors of nonlinearities in metasurfaces to achieve femtosecond switching speed is also discussed. Furthermore, the impact of quantum effects from the metasurface on the nonlinearities is introduced. Finally, an outlook on the future development of this energetic field is offered.

Recent Progress in Lithium Niobate: Optical Damage, Defect Simulation, and On‐Chip Devices

By Yongfa Kong, Fang Bo, Weiwei Wang, Dahuai Zheng, Hongde Liu, Guoquan Zhang, Romano Rupp, Jingjun Xu from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Lithium niobate (LN) is often dubbed as the “silicon of nonlinear optics” or “silicon of photonics”. It has played a prominent role in many breakthroughs in the past two decades. An overview of recent progress in optical damage, defect simulation, and on‐chip devices of LN is presented, and nonlinear optical effects, in particular photorefractive effects, are briefly reviewed. Abstract Lithium niobate (LN) is one of the most important synthetic crystals. In the past two decades, many breakthroughs have been made in material technology, theoretical understanding, and application of LN crystals. Recent progress in optical damage, defect simulation, and on‐chip devices of LN are explored. Optical damage is one of the main obstacles for the practical usage of LN crystals. Recent results reveal that doping with ZrO2 not only leads to better optical damage resistance in the visible but also improves resistance in the ultraviolet region. It is still awkward to extract defect characteristics and their relationship with the physical properties of LN crystals directly from experimental investigations. Recent simulations provide detailed descriptions of intrinsic defect models, the site occupation of dopants and the variation of energy levels due to extrinsic defects. LN is considered to be one of the most promising platforms for integrated photonics. Benefiting from advances in smart‐cut, direct wafer bonding and layer transfer techniques, great progress has been made in the past decade for LNs on insulators. Recent progress on on‐chip LN micro‐photonic devices and nonlinear optical effects, in particular photorefractive effects, are briefly reviewed.

Metasurface‐Empowered Optical Multiplexing and Multifunction

By Shuqi Chen, Wenwei Liu, Zhancheng Li, Hua Cheng, Jianguo Tian from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Metasurfaces enabling concurrent tasks through a dramatic compact design have drawn great interest from the scientific community due to their profound potential in integrated photonic systems. A classification of multiplexing and multifunctional metasurfaces is provided, the evolving trends are discussed, and the development of integrated and on‐chip multifunctional metasurfaces is summarized. Abstract Metasurfaces are planar photonic elements composed of subwavelength nanostructures, which can deeply interact with light and exploit new degrees of freedom (DOF) to manipulate optical fields. In the past decade, metasurfaces have drawn great interest from the scientific community due to their profound potential to arbitrarily control light. Here, recent developments of multiplexing and multifunctional metasurfaces, which enable concurrent tasks through a dramatic compact design, are reviewed. The fundamental properties, design strategies, and applications of multiplexing and multifunctional metasurfaces are then discussed. First, recent progress on angular momentum multiplexing, including its behavior under different incident conditions, is considered. Second, a detailed overview of polarization‐controlled, wavelength‐selective, angle‐selective, and reconfigurable multiplexing/multifunctional metasurfaces is provided. Then, the integrated and on‐chip design of multifunctional metasurfaces is addressed. Finally, future directions and potential applications are presented.

Toward Cluster Materials with Ordered Structures via Self‐Assembly of Heterocluster Janus Molecules

By Li‐Jun Ren, Hong‐Kai Liu, Han Wu, Min‐Biao Hu, Wei Wang from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Inspired by lipid self‐assembly and nanocluster functionalities, the design and subsequent creation of a series of heterocluster Janus molecules (HCJMs) are pioneered. Owing to efficient shape control, HCJMs self‐assemble into nanostructures that can go beyond those of predicated nanoaggregates of traditional amphiphiles. Thus, an efficient strategy for bridging the gap between clusters and cluster materials is established. Abstract Cluster materials have attracted much attention because of their unique chemical and physical properties, hitherto unseen in bulk materials. Inspired by the lipid self‐assembly principle, a series of heterocluster Janus molecules (HCJMs) with atomic precision have been rationally designed and synthesized by connecting different clusters via covalent bonds for the construction of nanomaterials and nano‐objects. Due to their amphiphilicity, HCJMs self‐assemble into cluster‐containing nanomaterials or nano‐objects with versatile ordered structures beyond those observed in conventional crystals. Their hybrid composition and nanoscale size are also greatly advantageous in the study of their fine structure by electron microscopy techniques, and enable their formation mechanisms to be unraveled. Finally, the influence of the characteristics of the HCJMs on the structure and properties of the self‐assembled nano‐objects are explored comprehensively. This synthesis strategy will promote further development of cluster materials with advanced functions via rational molecular design toward the construction of hierarchical nanostructures via molecular self‐assembly.

Nitric‐Oxide‐Releasing Biomaterial Regulation of the Stem Cell Microenvironment in Regenerative Medicine

By Adam C. Midgley, Yongzhen Wei, Zongjin Li, Deling Kong, Qiang Zhao from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Nitric oxide (NO), a gasotransmitter, is found to have unprecedented actions in the regulation of stem cell function and subsequent influence over the regenerative tissue microenvironment, offering an attractive solution to the limitations associated with stem cell therapy alone. Recent advances in biomaterial carriers for combined stem cell and NO therapy are assessed. Abstract Stem cell therapy has proven to be an attractive solution for the treatment of degenerative diseases or injury. However, poor cell engraftment and survival within injured tissues limits the successful use of stem cell therapy within the clinical setting. Nitric oxide (NO) is an important signaling molecule involved in various physiological processes. Emerging evidence supports NO's diverse roles in modulating stem cell behavior, including survival, migration, differentiation, and paracrine secretion of proregenerative factors. Thus, there has been a shift in research focus to concentrate efforts on the delivery of therapeutic concentration ranges of NO to the target tissue sites. Combinatory therapies utilizing biomaterials that control NO generation and support stem cell delivery can be holistic and synergistic approaches to significantly improve tissue regeneration. Here, the focus is on recent developments of various therapeutic platforms, engineered to both transport NO and to enhance stem‐cell‐mediated regeneration of damaged tissues. New and emerging revelations of how the stem cell microenvironment can be regulated by NO‐releasing biomaterials are also highlighted.

Cyclodextrin‐Based Multistimuli‐Responsive Supramolecular Assemblies and Their Biological Functions

By Ying‐Ming Zhang, Yao‐Hua Liu, Yu Liu from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Recent progress in cyclodextrin‐based multistimuli‐responsive supramolecular assemblies is systematically reviewed, their biological functions are presented by selecting some representative examples, and future perspectives and challenges in this promising field are discussed. Abstract Cyclodextrins (CDs), which are a class of cyclic oligosaccharides extracted from the enzymatic degradation of starch, are often utilized in molecular recognition and assembly constructs, primarily via host–guest interactions in water. In this review, recent progress in CD‐based supramolecular nanoassemblies that are sensitive to chemical, biological, and physical stimuli is updated and reviewed, and intriguing examples of the biological functions of these nanoassemblies are presented, including pH‐ and redox‐responsive drug and gene delivery, enzyme‐activated specific cargo release, photoswitchable morphological interconversion, microtubular aggregation, and cell–cell communication, as well as a geomagnetism‐controlled nanosystem for the suppression of tumor invasion and metastasis. Moreover, future perspectives and challenges in the fabrication of intelligent CD‐based biofunctional materials are also discussed at the end of this review, which is expected to promote the translational development of these nanomaterials in the biomedical field.

3D Graphene‐Based Macrostructures for Water Treatment

By Haitao Wang, Xueyue Mi, Yi Li, Sihui Zhan from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

The assembly of individual graphene nanosheets into 3D macrostructures provides an effective way to resolve the challenges met in their practical application. The recent advances in 3D graphene‐based macrostructures for water treatment are highlighted. A perspective on outstanding problems, future opportunities, and challenges is also provided. Abstract Recently, 3D graphene‐based macrostructures (3D GBMs) have gained increased attention due to their immense application potential in water treatment. The unique structural features (e.g., large surface area and physically interconnected porous network) as well as fascinating properties (e.g., high electrical conductivity, excellent chemical/thermal stability, ultralightness, and high solar‐to‐thermal conversion efficiency) render 3D GBMs as promising materials for water purification through adsorption, capacitive deionization, and solar distillation. Moreover, 3D GBMs can serve as scaffolds to immobilize powder nanomaterials to build monolithic adsorbents and photo‐/electrocatalysts, which significantly broadens their potential applications in water treatment. Here, recent advances in their synthesis and application toward water purification are highlighted. Remaining challenges and future perspectives are elaborated to highlight future research directions.

Multicenter Metal–Organic Framework‐Based Ratiometric Fluorescent Sensors

By Shuangyan Wu, Hui Min, Wei Shi, Peng Cheng from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Recent advances in both the strategies for the synthesis of MOF‐based ratiometric fluorescent sensors and their potential application in sensing pH values, ions, organic molecules, and biomolecules are summarized, with the aim of providing fundamentals for future studies of MOF‐based ratiometric fluorescent sensors. Abstract Metal–organic frameworks (MOFs) with multiple emission centers are newly emerging as ratiometric sensors owing to their high sensitivity and high selectivity toward a wide range of targeted functional species. Energy transfer between the light‐absorbing group and emission centers and between different emission centers is the key to rationally design and synthesize MOF‐based ratiometric sensors. A good match between the energy levels of the light‐absorbing groups and emission centers is the prerequisite for MOF‐based sensors to exhibit multiple emissions, and a good match of the MOF‐based sensors and those of the targeted species can increase the sensitivity and selectivity, but this match is highly challenging to obtain via synthesis. MOFs with multiple emission centers can be produced by functionalizing MOFs with multiple lanthanide centers, organic luminophores, dyes, carbon dots, and other such emissive groups. In this progress report, recent advances in the strategies for synthesizing MOFs with multiple emission centers and their applications for ratiometric sensing of solution conditions, including the pH value, and ion, organic molecule, and biomolecule concentrations, are summarized, as are the related sensing mechanisms.

Mimicking Molecular Chaperones to Regulate Protein Folding

By Fei‐He Ma, Chang Li, Yang Liu, Linqi Shi from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Artificial systems that mimic the functions of molecular chaperones are promising for biomedical applications. The recent state‐of‐the‐art progress in artificial chaperone systems and their applications are systematically summarized, giving deep insight into the principles and trends for the development of novel artificial chaperone systems to solve essential problems in biomedicine. Abstract Folding and unfolding are essential ways for a protein to regulate its biological activity. The misfolding of proteins usually reduces or completely compromises their biological functions, which eventually causes a wide range of diseases including neurodegeneration diseases, type II diabetes, and cancers. Therefore, materials that can regulate protein folding and maintain proteostasis are of significant biological and medical importance. In living organisms, molecular chaperones are a family of proteins that maintain proteostasis by interacting with, stabilizing, and repairing various non‐native proteins. In the past few decades, efforts have been made to create artificial systems to mimic the structure and biological functions of nature chaperonins. Herein, recent progress in the design and construction of materials that mimic different kinds of natural molecular chaperones is summarized. The fabrication methods, construction rules, and working mechanisms of these artificial chaperone systems are described. The application of these materials in enhancing the thermal stability of proteins, assisting de novo folding of proteins, and preventing formation of toxic protein aggregates is also highlighted and explored. Finally, the challenges and potential in the field of chaperone‐mimetic materials are discussed.

Regulating the Photophysical Property of Organic/Polymer Optical Agents for Promoted Cancer Phototheranostics

By Chao Chen, Hanlin Ou, Ruihua Liu, Dan Ding from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

The main strategies for regulating the photophysical properties of organic/polymer optical agents to achieve superior biomedical applications in cancer diagnosis/phototheranosis are highlighted. The approaches of nanoengineering and molecular design, which can lead to optimized effectiveness of required biomedical function, are discussed. Abstract On the basis of the Jablonski diagram, the photophysical properties of optical agents are highly associated with biomedical function and efficacy. Herein, the focus is on organic/polymer optical agents and the recent progress in the main strategies for regulating their photophysical properties to achieve superior cancer diagnosis/phototheranostics applications are highlighted. Both the approaches of nanoengineering and molecular design, which can lead to optimized effectiveness of required biomedical function, are discussed.

Integrated Perovskite/Bulk‐Heterojunction Organic Solar Cells

By Yongsheng Liu, Yongsheng Chen from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Integrated perovskite/bulk‐heterojunction (BHJ) organic solar cells have shown great potential to further improve their performance by combining the advantages of perovskite solar cells and near‐infrared (NIR) BHJ organic solar cells. Combining with the maintained high VOC, higher efficiencies are expected by fully optimizing the perovskite layers and NIR BHJ layers through device engineering and materials innovations. Abstract The recently emerged integrated perovskite/bulk‐heterojunction (BHJ) organic solar cells (IPOSCs) without any recombination layers have generated wide attention. This type of device structure can take the advantages of tandem cells using both perovskite solar and near‐infrared (NIR) BHJ organic solar materials for wide‐range sunlight absorption and the simple fabrication of single junction cells, as the low bandgap BHJ layer can provide additional light harvesting in the NIR region and the high open‐circuit voltage can be maintained at the same time. This progress report highlights the recent developments in such IPOSCs and the possible challenges ahead. In addition, the recent development of perovskite solar cells and NIR organic solar cells is also covered to fully underline the importance and potential of IPOSCs.

Semitransparent Perovskite Solar Cells: From Materials and Devices to Applications

By Biao Shi, Linrui Duan, Ying Zhao, Jingshan Luo, Xiaodan Zhang from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Semi‐transparent perovskite solar cells (ST‐PSCs) have received great attention due to their promising applications in many areas, such as building integrated photovoltaics (BIPV), tandem devices, and wearable electronics. A general overview of recent advances in ST‐PSCs from materials and devices to applications is provided, and presented alongside some personal perspectives on their future development. Abstract Semitransparent solar cells (ST‐SCs) have received great attention due to their promising application in many areas, such as building integrated photovoltaics (BIPVs), tandem devices, and wearable electronics. In the past decade, perovskite solar cells (PSCs) have revolutionized the field of photovoltaics (PVs) with their high efficiencies and facile preparation processes. Due to their large absorption coefficient and bandgap tunability, perovskites offer new opportunities to ST‐SCs. Here, a general overview is provided on the recent advances in ST‐PSCs from materials and devices to applications and some personal perspectives on the future development of ST‐PSCs.

Low‐Cost Counter‐Electrode Materials for Dye‐Sensitized and Perovskite Solar Cells

By Guo‐Ran Li, Xue‐Ping Gao from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Low‐cost counter materials for dye‐sensitized and perovskite solar cells are summarized, with a focus on the regular patterns that appear in their intrinsic features and structural design. Abstract It is undoubtable that the use of solar energy will continue to increase. Solar cells that convert solar energy directly to electricity are one of the most convenient and important photoelectric conversion devices. Though silicon‐based solar cells and thin‐film solar cells have been commercialized, developing low‐cost and highly efficient solar cells to meet future needs is still a long‐term challenge. Some emerging solar‐cell types, such as dye‐sensitized and perovskite, are approaching acceptable performance levels, but their costs remain too high. To obtain a higher performance–price ratio, it is necessary to find new low‐cost counter materials to replace conventional precious metal electrodes (Pt, Au, and Ag) in these emerging solar cells. In recent years, the number of counter‐electrode materials available, and their scope for further improvement, has expanded for dye‐sensitized and perovskite solar cells. Generally regular patterns in the intrinsic features and structural design of counter materials for emerging solar cells, in particular from an electrochemical perspective and their effects on cost and efficiency, are explored. It is hoped that this recapitulative analysis will help to make clear what has been achieved and what still remains for the development of cost‐effective counter‐electrode materials in emerging solar cells.

Halide Perovskites for Nonlinear Optics

By Jialiang Xu, Xinyue Li, Jianbo Xiong, Chunqing Yuan, Sergey Semin, Theo Rasing, Xian‐He Bu from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Halide perovskites are a promising platform for the construction of nonlinear optical materials in light of their structural diversity, high hyperpolarizability, and bandgap tunability. The current state of the art in purely inorganic and organic–inorganic hybrid halide perovskites as nonlinear optical materials is reviewed and their potential in various nonlinear photonic applications is discussed. Abstract Halide perovskites provide an ideal platform for engineering highly promising semiconductor materials for a wide range of applications in optoelectronic devices, such as photovoltaics, light‐emitting diodes, photodetectors, and lasers. More recently, increasing research efforts have been directed toward the nonlinear optical properties of halide perovskites because of their unique chemical and electronic properties, which are of crucial importance for advancing their applications in next‐generation photonic devices. Here, the current state of the art in the field of nonlinear optics (NLO) in halide perovskite materials is reviewed. Halide perovskites are categorized into hybrid organic/inorganic and pure inorganic ones, and their second‐, third‐, and higher‐order NLO properties are summarized. The performance of halide perovskite materials in NLO devices such as upconversion lasers and ultrafast laser modulators is analyzed. Several potential perspectives and research directions of these promising materials for nonlinear optics are presented.

Binder‐Free Electrodes for Advanced Sodium‐Ion Batteries

By Ting Jin, Qingqing Han, Lifang Jiao from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Binder‐free electrodes possess great merits with fast electron transport and increased energy density, and so provide a fascinating opportunity for the creation of high‐performance sodium‐ion batteries. Template‐free methods mainly combine with graphene, carbon nanotubes, and carbon nanofibers, while template‐assisted methods are based on carbon (e.g., carbon paper, carbon cloth, etc.) and metal substrates (e.g., Cu foil, Ti foil, Ni foam, etc.). Abstract Sodium‐ion batteries (SIBs) have recently emerged as one of the favored contenders for use in medium and large‐scale stationary energy storage owing to the abundance of the resources required to fabricate them, their low cost, and the fact that have properties similar to equivalent Li batteries. However, their development also faces challenges such as poor cycling stability and unsatisfying rate performance. In traditional electrodes, binders are commonly used to integrate individual active materials with conductive additives. Unfortunately, binders are generally electrochemically inactive and insulating, which reduces the overall energy density and leads to poor cycling stability. Therefore, binder‐free electrodes provide great opportunity for high‐performance SIBs in terms of both improved electronic conductivity and electrochemical reaction reversibility. This Progress Report provides an overview of the recent progress in binder‐free electrodes for SIBs. It focuses on the current challenges of binder‐free electrodes and provides an outlook for their future in energy conversion and storage.

Enzyme‐Instructed Self‐Assembly (EISA) and Hydrogelation of Peptides

By Jie Gao, Jie Zhan, Zhimou Yang from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Enzyme‐instructed self‐assembly (EISA) has several unique properties and advantages in preparing biofunctional supramolecular nanomaterials from peptides. Recent progress in this area is reviewed, with a focus on in situ EISA, precursor involved EISA, controlling peptide folding by EISA, and the combination of other methods with EISA. The perspectives and challenges are also discussed. Abstract Self‐assembly is a powerful tool for constructing supramolecular materials for many applications, ranging from energy harvesting to biomedicine. Among the methods to prepare supramolecular materials for biomedical applications, enzyme‐instructed self‐assembly (EISA) has several advantages. Herein, the unique properties and advantages of EISA in preparing biofunctional supramolecular nanomaterials and hydrogels from peptides are highlighted. EISA can trigger molecular self‐assembly in situ. Therefore, using overexpression enzymes in disease sites, supramolecular materials can be formed in situ to improve the selectivity and efficacy of the treatment. The precursor may be involved during the EISA process, and it is actually a two‐component self‐assembly process. The precursor can help to stabilize the assembled nanostructures of hydrophobic peptides formed by EISA. More importantly, the precursor may determine the outcome of molecular self‐assembly. Recently, it was also observed that EISA can kinetically control the peptide folding and morphology and cellular uptake behavior of supramolecular nanomaterials. With the combination of other methods to trigger molecular self‐assembly, researchers can form supramolecular nanomaterials in a more precise mode and sometimes under spatiotemporal control. EISA is a powerful and unique methodology to prepare supramolecular biofunctional materials that cannot be generated from other common methods.

Recent Development of Printed Micro‐Supercapacitors: Printable Materials, Printing Technologies, and Perspectives

By Hongpeng Li, Jiajie Liang from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Printed micro‐supercapacitors, with in‐plane interdigital configurations created by printing technology, have been touted as a promising miniaturized energy‐storage device to provide a continuous power supply to drive wearable on‐chip integrated electronics. Critical printable materials and printing techniques are presented to push forward the full materialization of widespread adoption of printed micro‐supercapacitors. Abstract The rapid progression of portable and wearable electronics has necessitated the development of high‐performing, miniaturized energy‐storage devices with flexible form factors and high energy and power delivery. Printed micro‐supercapacitors (MSCs), with in‐plane interdigital configurations, is touted as a promising choice to fulfill these requirements. New printing technologies can assemble MSCs with fiscal and environmental benefits, large form factors, and at high throughputs, qualities not afforded with conventional microfabrication technologies. Here, recent progress in the preparation of functional ink systems for wearable MSCs, encompassing electrode materials, conductor materials, and electrolytes, is presented. First, a comprehensive background of the fundamentals of printing technology is introduced, with discussions focusing on methods of improving ink functionality while simultaneously retaining good printability. Second, various printing techniques to ensure manufacturable scaling of wearable MSCs with high areal electrochemical performance and small footprint are explored. Within the scope of these two topics, various issues that hinder the full materialization of widespread adoption of printed MSC and next steps to overcome these issues are discussed. Further deep dives in scientific and technical challenges are also presented, including limited functionality of the inks, low printing resolution, overlay accuracy, and complex encapsulation.

Self‐Supported Transition‐Metal‐Based Electrocatalysts for Hydrogen and Oxygen Evolution

By Hongming Sun, Zhenhua Yan, Fangming Liu, Wence Xu, Fangyi Cheng, Jun Chen from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Self‐supported transition‐metal hydrogen and oxygen evolution electrocatalysts combining advantages of low cost, high mechanical strength, abundant exposed active sites, and facile charge transfer are attractive for water electrolysis. An overview of recent progress is presented by highlighting the materials selection, electrode structure design, electrocatalytic property investigation, and performance enhancement strategies of example self‐supported electrodes. Abstract Electrochemical water splitting is a promising technology for sustainable conversion, storage, and transport of hydrogen energy. Searching for earth‐abundant hydrogen/oxygen evolution reaction (HER/OER) electrocatalysts with high activity and durability to replace noble‐metal‐based catalysts plays paramount importance in the scalable application of water electrolysis. A freestanding electrode architecture is highly attractive as compared to the conventional coated powdery form because of enhanced kinetics and stability. Herein, recent progress in developing transition‐metal‐based HER/OER electrocatalytic materials is reviewed with selected examples of chalcogenides, phosphides, carbides, nitrides, alloys, phosphates, oxides, hydroxides, and oxyhydroxides. Focusing on self‐supported electrodes, the latest advances in their structural design, controllable synthesis, mechanistic understanding, and strategies for performance enhancement are presented. Remaining challenges and future perspectives for the further development of self‐supported electrocatalysts are also discussed.

Molecularly Imprinted Nanoparticles for Biomedical Applications

By Huiqi Zhang from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Molecularly imprinted nanoparticles (nanoMIPs) represent an emerging class of biomedically important synthetic receptors owing to their high affinity and selectivity, excellent stability, easy preparation, low cost, biocompatibility, and multifunctionality. Recent progress of nanoMIP design and their biomedical applications in immunoassays, drug delivery, bioimaging, and biomimetic nanomedicine are summarized, and the challenges and opportunities in current nanoMIP biomedical research are discussed. Abstract Molecularly imprinted polymers (MIPs) are synthetic receptors with tailor‐made recognition sites for target molecules. Their high affinity and selectivity, excellent stability, easy preparation, and low cost make them promising substitutes to biological receptors in many applications where molecular recognition is important. In particular, spherical MIP nanoparticles (or nanoMIPs) with diameters typically below 200 nm have drawn great attention because of their high surface‐area‐to‐volume ratio, easy removal of templates, rapid binding kinetics, good dispersion and handling ability, undemanding functionalization and surface modification, and their high compatibility with various nanodevices and in vivo biomedical applications. Recent years have witnessed significant progress made in the preparation of advanced functional nanoMIPs, which has eventually led to the rapid expansion of the MIP applications from the traditional separation and catalysis fields to the burgeoning biomedical areas. Here, a comprehensive overview of key recent advances made in the preparation of nanoMIPs and their important biomedical applications (including immunoassays, drug delivery, bioimaging, and biomimetic nanomedicine) is presented. The pros and cons of each synthetic strategy for nanoMIPs and their biomedical applications are discussed and the present challenges and future perspectives of the biomedical applications of nanoMIPs are also highlighted.

Formation of CX Bonds in CO2 Chemical Fixation Catalyzed by Metal−Organic Frameworks

By Sheng‐Li Hou, Jie Dong, Bin Zhao from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

The transformation of CO2 into value‐added chemicals has received particular attention in recent years. The formation of covalent bonds between CO2 and substrates catalyzed by metal–organic frameworks are summarized. The catalytic mechanism of generating different CX bonds is discussed. The critical challenges and potential solutions, future opportunities and prospects in this field are also covered. Abstract Transformation of CO2 based on metal−organic framework (MOF) catalysts is becoming a hot research topic, not only because it will help to reduce greenhouse gas emission, but also because it will allow for the production of valuable chemicals. In addition, a large number of impressive products have been synthesized by utilizing CO2. In fact, it is the formation of new covalent bonds between CO2 and substrate molecules that successfully result in CO2 solidly inserting into the products, and only four types of new CX bonds, including CH, CC, CN, and CO bonds, are observed in this exploration. An overview of recent progress in constructing CX bonds for CO2 conversion catalyzed by various MOF catalysts is provided. The catalytic mechanism of generating different CX bonds is further discussed according to both structural features of MOFs and the interactions among CO2, substrates, as well as MOFs. The future opportunities and challenges in this field are also tentatively covered.

Ultrathin 2D Rare‐Earth Nanomaterials: Compositions, Syntheses, and Applications

By Jun Xu, Xiaoyun Chen, Yueshan Xu, Yaping Du, Chunhua Yan from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Incorporation of rare‐earth elements into the layers of ultrathin 2D nanomaterials yields an emerging class of functional materials with unique optical, magnetic, and catalytic properties. All families of ultrathin 2D rare‐earth nanomaterials are reviewed, focusing on their compositions, syntheses, and applications. Abstract Ultrathin 2D nanomaterials possess promising properties due to electron confinement within single or a few atom layers. As an emerging class of functional materials, ultrathin 2D rare‐earth nanomaterials may incorporate the unique optical, magnetic, and catalytic behaviors of rare‐earth elements into layers, exhibiting great potential in various applications such as optoelectronics, magnetic devices, transistors, high‐efficiency catalysts, etc. Despite its importance, reviews on ultrathin 2D rare‐earth nanomaterials or related topics are rare and only focus on a certain family of ultrathin 2D rare‐earth nanomaterials. This work is the first comprehensive review in this impressive field, which covers all families of ultrathin 2D rare‐earth nanomaterials, illustrating their compositions, syntheses, and applications. After summarizing the current achievements, the challenges and opportunities of future research on ultrathin 2D rare‐earth nanomaterials are evaluated.

Self‐Limiting Assembly Approaches for Nanoadditive Manufacturing of Electronic Thin Films and Devices

By Zhao Wang, Yu Kang, Sanchuan Zhao, Jian Zhu from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

Nanoadditive manufacturing of functional nanofilms through layer‐by‐layer (LbL) deposition of electronically desired components is an important approach to realize the precise control of solution‐based film growth and device fabrication. Such manufacturing approaches are summarized, particularly focusing on Langmuir–Blodgett assembly and LbL assembly. LbL‐manufactured electronic materials are reviewed with detailed discussion of their electronic applications. Abstract Most electronics consist of functional thin films with tens of nanometer thicknesses. It is usually challenging to control the growth of these thin films using conventional solution‐based approaches. Nanoadditive manufacturing, a method to deposit electronically desired molecules, polymers, or nanomaterials in a layer‐by‐layer (LbL) fashion, has emerged as a promising technique for the precise control of film growth and device fabrication. Here, basic principles of nanoadditive manufacturing approaches with self‐limiting characteristics are summarized with a particular focus on Langmuir–Blodgett assembly and LbL assembly. Additively manufactured electronic thin films with properties of conductors, semiconductors, and dielectrics are reviewed, followed by a discussion of their application in various electronics, such as field‐effect transistors, sensors, memory devices, photodetectors, light‐emitting diodes, and electrochromic devices. Finally, challenges and future developments of these approaches are proposed. The resulting analysis reveals promising opportunities of nanoadditive manufacturing for the solution‐based fabrication of electronic devices.

Metal–Organic Framework Materials for the Separation and Purification of Light Hydrocarbons

By Wen‐Gang Cui, Tong‐Liang Hu, Xian‐He Bu from Wiley: Advanced Materials: Table of Contents. Published on Jan 21, 2020.

The recent advances of using metal–organic framework (MOF) materials as separating agents in the separation and purification of light hydrocarbons mixtures are summarized. The existing challenges and possible research directions related to the further exploration of porous MOFs in this very active field are also presented. Abstract The separation and purification of light hydrocarbons (LHs) mixtures is one of the most significantly important but energy demanding processes in the petrochemical industry. As an alternative technology to energy intensive traditional separation methods, such as distillation, absorption, extraction, etc., adsorptive separation using selective solid adsorbents could potentially not only lower energy cost but also offer higher efficiency. The need to develop solid materials for the efficiently selective adsorption of LHs molecules, under mild conditions, is therefore of paramount importance and urgency. Metal–organic frameworks (MOFs), emerging as a relatively new class of porous organic–inorganic hybrid materials, have shown promise for addressing this challenging task due to their unparalleled features. Herein, recent advances of using MOFs as separating agents for the separation and purification of LHs, including the purification of CH4, and the separations of alkynes/alkenes, alkanes/alkenes, C5–C6–C7 normal/isoalkanes, and C8 alkylaromatics, are summarized. The relationships among the structural and compositional features of the newly synthesized MOF materials and their separation properties and mechanisms are highlighted. Finally, the existing challenges and possible research directions related to the further exploration of porous MOFs in this very active field are also discussed.

Wed 04 Mar 13:00: Learning from sociological case studies

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Learning from sociological case studies

Abstract not available

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Wed 26 Feb 13:00: Epistemic engagement, aesthetic value and scientific practice

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Epistemic engagement, aesthetic value and scientific practice

I provide an account of the relationship between aesthetic sensibility and knowledge, with a focus on scientific practice. Cognitivist accounts, such as that recently defended by Derek Turner, problematically conflate ‘partial sensitivity’ – the idea that aesthetic appreciation partly depends on doxastic states – and factivity, the idea that those beliefs need to be true. Rejecting factivity, I develop a notion of ‘epistemic engagement’: partaking genuinely in a knowledge-directed process of coming to epistemic judgements, and suggest that this better accommodates the relationship between the aesthetic and the epistemic. Scientific training (and other epistemic-directed activities), I argue, involve ‘attunement’: the co-option of aesthetic judgements towards epistemic ends. This view has consequences for the justification of aesthetic judgment in science, namely, the locus of justification are those processes of attunement, not the aesthetic judgements themselves.

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Wed 29 Jan 13:00: Creativity and AI

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Creativity and AI

In March 2016, DeepMind’s computer program AlphaGo surprised the world by defeating the world-champion Go player, Lee Sedol. AlphaGo has a novel, surprising and valuable style of play, and has been recognized as ‘creative’ by the AI and Go communities. This paper examines whether AlphaGo engages in creative problem solving according to the standards of comparative psychology. I conclude that although AlphaGo lacks one important aspect of creative problem solving found in animals (domain generality) it exhibits a different capacity for creativity: namely, the ability to transform a conceptual space through something akin to instrumental conditioning. This analysis has consequences for how we think about creativity in humans and AI.

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Wed 12 Feb 13:00: The good news about killing people

From All Talks (aka the CURE list). Published on Jan 21, 2020.

The good news about killing people

Modern economics has designed a body of theory for how to make decisions involving irreversible outcomes. Motivated by this theory, we propose a ‘Good News Principle’ for the decision to kill one’s self or others, which states that such a decision depends on the quantity and probability of future good news (supporting not killing), but not of future bad news (supporting killing). We then derive this principle as a theorem of a simple consequentialist model for irreversible acts.

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Wed 05 Feb 13:00: The search for invertebrate consciousness

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Tue 04 Feb 13:10: "Whatever they (weigh) will be given to him in plenty”: Commemorative Objects as Expression of Mercantile Religious Identities in the Ancient Near East

From All Talks (aka the CURE list). Published on Jan 21, 2020.

"Whatever they (weigh) will be given to him in plenty”: Commemorative Objects as Expression of Mercantile Religious Identities in the Ancient Near East

Throughout the history of Mesopotamian commemorative practice, individuals often included their professional title such as scribe, temple administrator, merchant, etc. within their inscription and thus signaled their social status and social network in their message to the god(s) and, perhaps even their peers. This paper will focus on the commemorative inscriptions and dedicatory practices of one such professional group that is highly represented in commemorative inscriptions of the third and second millennia: the merchant (dam-gàr/tamkārum). Through a holistic analysis of the textual content, material, object type, and archaeological context of these inscribed objects, we can better understand the merchants’ access to raw materials, access to the temple, and relationships with other professional groups, officials, and the royal family. Furthermore, one can explore how understand how merchants viewed themselves with regards to their work and how that work shaped their access to, and ways of communicating, with the divine. These mercantile dedicatory and commemorative practices will be discussed within the larger framework of greater religious beliefs and practices that intersected with the professional lifeways of merchants as well as extant knowledge on the social status and networks of these highly connected and mobile people in the ancient Near East.

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Tue 11 Feb 13:10: Frequent job changes can signal poor work attitude and reduce employability

From All Talks (aka the CURE list). Published on Jan 21, 2020.

Frequent job changes can signal poor work attitude and reduce employability

We study whether employment history provides information about a worker’s “work attitude,” i.e., the tendency to act cooperatively and reliably in the workplace. We conjecture that, holding all else equal, frequent job changes can indicate poor work attitude and that this information is transmitted through employment histories. We find support for this hypothesis across three studies that employ complementary lab, field, and survey experiments, as well as in labor market panel data. First, a tightly controlled laboratory labor market experiment demonstrates that prior employment information allows employers to screen for reliable and cooperative workers and that these workers obtain better employment outcomes. Second, we conduct a field experiment that varies the frequency of job changes in applicants’ resumes and find that those with fewer job changes receive substantially more callbacks from prospective employers. Third, a survey experiment with Human Resources professionals confirms that the resume manipulations in the field study create different perceptions of work attitude and that these largely account for the callback differences. Finally, we find evidence consistent with our hypothesized relationships in empirical labor market data. Our work highlights the potential importance of job history as a signal of work attitude in labor markets, and points to a potential cost of frequent job changes

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Catalytic Enantioselective Direct Aldol Addition of Aryl Ketones to α‐Fluorinated Ketones

By Connor Jack Thomson, David M Barber, Darren James Dixon from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 21, 2020.

The catalytic enantioselective synthesis of α‐fluorinated chiral tertiary alcohols from (hetero)aryl methyl ketones is described. The use of a bifunctional iminophosphorane (BIMP) superbase was found to facilitate direct aldol addition by providing the strong Brønsted basicity required for rapid aryl enolate formation. The new synthetic protocol is easy to perform and tolerates a broad range of functionalities and heterocycles with high enantioselectivity (up to >99:1 er). Multi‐gram scalability has been demonstrated along with catalyst recovery and recycling. NMR studies identified a 1400‐fold rate enhancement under BIMP catalysis, compared to the current state of the art catalytic system. The utility of the aldol products has been highlighted with the synthesis of various enantioenriched building blocks and heterocycles, including 1,3‐aminoalcohol, 1,3‐diol, oxetane and isoxazoline derivatives.

Dynamic Passivation in Perovskite Quantum Dots for Specific Ammonia Detection at Room Temperature

By Hui Huang, Mingwei Hao, Yilong Song, Song Dang, Xiaoting Liu, Qingfeng Dong from Wiley: Small: Table of Contents. Published on Jan 21, 2020.

Ammonia gas can effectively passivate surface defects of perovskite quantum dots with enhanced photoluminescence, which enables a specific recognition behavior toward ammonia at room‐temperature. The turn‐on mode sensor, with high sensitivity and selectivity, shows a fast and fully reversible response and a wide detection range and a limit of detection of 8.85 ppm. Abstract Perovskite structured CsPbX3 (X = Cl, Br, or I) quantum dots (QDs) have attracted considerable interest in the past few years due to their excellent optoelectronic properties. Surface passivation is one of the main pathways to optimize the optoelectrical performance of perovskite QDs, in which the amino group plays an important role for the corresponding interaction between lead and halide. In this work, it is found that ammonia gas could dramatically increase photoluminescence of purified QDs and effectively passivate surface defects of perovskite QDs introduced during purification, which is a reversible process. This phenomenon makes perovskite QDs a kind of ideal candidate for detection of ammonia gas at room temperature. This QD film sensor displays specific recognition behavior toward ammonia gas due to its significant fluorescence enhancement, while depressed luminescence in case of other gases. The sensor, in turn‐on mode, shows a wide detection range from 25 to 350 ppm with a limit of detection as low as 8.85 ppm. Meanwhile, a fast response time of ≈10 s is achieved, and the recovery time is ≈30 s. The fully reversible, high sensitivity and selectivity characteristics make CsPbBr3 QDs ideal active materials for room‐temperature ammonia sensing.

[ASAP] Ambipolar Resistive Switching in an Ultrathin Surface-Supported Metal–Organic Framework Vertical Heterojunction

By Luiz G. S. Albano†, Tatiana P. Vello†‡, Davi H. S. de Camargo†§, Ricardo M. L. da Silva†§, Antonio C. M. Padilha†, Adalberto Fazzio†, and Carlos C. B. Bufon*†‡§ from Nano Letters: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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Nano Letters
DOI: 10.1021/acs.nanolett.9b04355

[ASAP] Probing Single-Particle Electrocatalytic Activity at Facet-Controlled Gold Nanocrystals

By Myunghoon Choi‡, Natasha P. Siepser‡, Soojin Jeong‡, Yi Wang, Gargi Jagdale, Xingchen Ye*, and Lane A. Baker* from Nano Letters: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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Nano Letters
DOI: 10.1021/acs.nanolett.9b04640

[ASAP] Functional Group Mapping by Electron Beam Vibrational Spectroscopy from Nanoscale Volumes

By Sean M. Collins*†#, Demie M. Kepaptsoglou‡§, Jingwei Hou†?, Christopher W. Ashling†, Guillaume Radtke||, Thomas D. Bennett†, Paul A. Midgley†, and Quentin M. Ramasse‡? from Nano Letters: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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Nano Letters
DOI: 10.1021/acs.nanolett.9b04732

[ASAP] Stochastic Stress Jumps Due to Soliton Dynamics in Two-Dimensional van der Waals Interfaces

By SunPhil Kim†, Emil Annevelink†, Edmund Han‡, Jaehyung Yu†, Pinshane Y. Huang‡, Elif Ertekin†, and Arend M. van der Zande*† from Nano Letters: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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Nano Letters
DOI: 10.1021/acs.nanolett.9b04619

[ASAP] Unusual Hole and Electron Midgap States and Orbital Reconstructions Induced Huge Ferroelectric Tunneling Electroresistance in BaTiO3/SrTiO3

By Xiao Chi†§??, Han Wang??, Rui Guo??, Thomas J. Whitcher†?, Xiaojiang Yu†, Ping Yang†, Xiaobing Yan?, Mark B. H. Breese†‡, Kian Ping Loh*§?#, Jingsheng Chen*§, and Andrivo Rusydi*†‡?#?? from Nano Letters: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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Nano Letters
DOI: 10.1021/acs.nanolett.9b04390

[ASAP] Artificial Wooden Nacre: A High Specific Strength Engineering Material

By Yipeng Chen†, Jinzhou Fu‡, Baokang Dang†, Qingfeng Sun*†, Huiqiao Li*‡§, and Tianyou Zhai‡§ from ACS Nano: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b08647

[ASAP] Self-Assembly of Aromatic Amino Acid Enantiomers into Supramolecular Materials of High Rigidity

By Santu Bera†, Bin Xue‡, Pavel Rehak?, Guy Jacoby?, Wei Ji†, Linda J. W. Shimon§, Roy Beck?, Petr Kra´l?¶, Yi Cao‡, and Ehud Gazit*† from ACS Nano: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b07307

[ASAP] 3D-Printed Ultra-Robust Surface-Doped Porous Silicone Sensors for Wearable Biomonitoring

By Elham Davoodi†‡#, Hossein Montazerian‡#§?, Reihaneh Haghniaz‡#, Armin Rashidi§, Samad Ahadian‡#, Amir Sheikhi‡#?, Jun Chen‡, Ali Khademhosseini‡#¶, Abbas S. Milani§, Mina Hoorfar?, and Ehsan Toyserkani*† from ACS Nano: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b06283

[ASAP] Cytosolic NQO1 Enzyme-Activated Near-Infrared Fluorescence Imaging and Photodynamic Therapy with Polymeric Vesicles

By Chenzhi Yao†, Yamin Li†, Zhixiong Wang‡, Chengzhou Song†, Xianglong Hu*‡, and Shiyong Liu*† from ACS Nano: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b08285

[ASAP] Three-Dimensional Perovskite Nanophotonic Wire Array-Based Light-Emitting Diodes with Significantly Improved Efficiency and Stability

By Qianpeng Zhang†, Daquan Zhang†‡, Leilei Gu†‡, Kwong-Hoi Tsui†, Swapnadeep Poddar†, Yu Fu†‡, Lei Shu†, and Zhiyong Fan*†‡ from ACS Nano: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b06663

[ASAP] Nanoparticles Encapsulating Nitrosylated Maytansine To Enhance Radiation Therapy

By Shi Gao†¶, Weizhong Zhang‡¶, Renjie Wang†¶, Sean P. Hopkins§, Jonathan C. Spagnoli‡, Mohammed Racin‡, Lin Bai†, Lu Li†, Wen Jiang‡, Xueyuan Yang‡, Chaebin Lee‡, Koichi Nagata?, Elizabeth W. Howerth?, Hitesh Handa§, Jin Xie*‡, Qingjie Ma*†, and Anil Kumar*‡ from ACS Nano: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b05976

[ASAP] Black Phosphorus High-Frequency Transistors with Local Contact Bias

By Cheng Li†?, Kuanchen Xiong‡?, Lei Li‡?, Qiushi Guo†, Xiaolong Chen†, Asher Madjar‡, Kenji Watanabe§, Takashi Taniguchi§, James C. M. Hwang*‡, and Fengnian Xia*† from ACS Nano: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b08834

[ASAP] Correction to Terminating DNA Tile Assembly with Nanostructured Caps

By Deepak K. Agrawal, Ruoyu Jiang, Seth Reinhart, Abdul M. Mohammed, Tyler D. Jorgenson, and Rebecca Schulman* from ACS Nano: Latest Articles (ACS Publications). Published on Jan 21, 2020.

ACS Nano
DOI: 10.1021/acsnano.0c00359

[ASAP] Engineering Substrate Interaction To Improve Hydrogen Evolution Catalysis of Monolayer MoS2 Films beyond Pt

By Guoqing Li†, Zehua Chen‡, Yifan Li§, Du Zhang‡, Weitao Yang‡, Yuanyue Liu§, and Linyou Cao*†?? from ACS Nano: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b07324

[ASAP] Digital Programming Graphene Oxide Liquid Crystalline Hybrid Hydrogel by Shearing Microlithography

By Jingyu Ma†, Senpeng Lin‡, Yanqiu Jiang†, Peng Li†, Hengjie Zhang‡, Zhen Xu*†, Huaping Wu*‡, Pengcheng Lin§, Josef Breu?, Weiwei Gao†, and Chao Gao*† from ACS Nano: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b09503

[ASAP] Spectroscopic and Magneto-Optical Signatures of Cu1+ and Cu2+ Defects in Copper Indium Sulfide Quantum Dots

By Addis Fuhr†‡, Hyeong Jin Yun†, Scott A. Crooker§, and Victor I. Klimov*† from ACS Nano: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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ACS Nano
DOI: 10.1021/acsnano.9b09181

[ASAP] Porous Nanosheet Assembly for Macrocyclization and Self-Release

By Xin Liu†?, Xiaobin Zhou†?, Bowen Shen†, Yongju Kim‡, Huaxin Wang†, Wanting Pan†, Jehan Kim§, and Myongsoo Lee*† from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11004

[ASAP] Harnessing Applied Potential: Selective ß-Hydrocarboxylation of Substituted Olefins

By Anas Alkayal, Volodymyr Tabas, Stephanie Montanaro, Iain A. Wright, Andrei V. Malkov*, and Benjamin R. Buckley* from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b13305

[ASAP] On-Surface Dehydro-Diels–Alder Reaction of Dibromo-bis(phenylethynyl)benzene

By Marco Di Giovannantonio†?, Ashok Keerthi‡§?, Jose´ I. Urgel†, Martin Baumgarten‡, Xinliang Feng?, Pascal Ruffieux†, Akimitsu Narita‡?, Roman Fasel*†#, and Klaus Mu¨llen*‡ from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b11755

[ASAP] NMR Experiments for Studies of Dilute and Condensed Protein Phases: Application to the Phase-Separating Protein CAPRIN1

By Leo E. Wong†‡§?, Tae Hun Kim†‡§??, D. Ranjith Muhandiram†‡§, Julie D. Forman-Kay‡?, and Lewis E. Kay*†‡§? from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12208

[ASAP] Redox-Active Phenanthrenequinone Triangles in Aqueous Rechargeable Zinc Batteries

By Kwan Woo Nam†, Heejin Kim‡, Yassine Beldjoudi†, Tae-woo Kwon†, Dong Jun Kim*§, and J. Fraser Stoddart*†§? from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b12436

[ASAP] Per-Residue Program of Multiple Backbone Dihedral Angles of ß-Peptoids via Backbone Substitutions

By Jumpei Morimoto*†?, Jungyeon Kim†?, Daisuke Kuroda†‡, Satoru Nagatoishi§, Kouhei Tsumoto†‡§, and Shinsuke Sando*†‡ from Journal of the American Chemical Society: Latest Articles (ACS Publications). Published on Jan 21, 2020.

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Journal of the American Chemical Society
DOI: 10.1021/jacs.9b10496

Call for Nominations: Carbon Journal Prize 2020

From Carbon. Published on .

The journal Carbon and its publisher Elsevier will be awarding the Carbon Journal Prize, given for “an outstanding Ph.D. thesis in carbon material science and technology”.

An ultrasensitive colorimetric test for the detection of somatic rare mutations in DNA

By Paola Valentini from RSC - Nanoscale latest articles. Published on Jan 21, 2020.

Nanoscale, 2020, Advance Article
DOI: 10.1039/C9NR10030J, Communication
Gayatri Udayan, Alessandra Marsella, Paola Valentini
We developed a rapid test to detect rare somatic point mutations in DNA by the naked-eye, with minimal instrumentation.
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RNA–DNA hybrid nanoshapes that self-assemble dependent on ligand binding

By Thomas Hermann from RSC - Nanoscale latest articles. Published on Jan 21, 2020.

Nanoscale, 2020, Advance Article
DOI: 10.1039/C9NR09706F, Paper
Shi Chen, Thomas Hermann
Composite nanoshapes self-assemble from RNA and DNA modules by coupling ligand binding to the formation of circularly closed structures.
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Atomic Modulation Triggering Improved Performance of MoO3 Nanobelts for Fiber‐Shaped Supercapacitors

By Si Liu, Cuixia Xu, Hui Yang, Guangsheng Qian, Shugui Hua, Jie Liu, Xusheng Zheng, Xihong Lu from Wiley: Small: Table of Contents. Published on Jan 20, 2020.

The demonstration of sulfur‐doped MoO3−x nanobelts as the anode for high‐performance fiber‐shaped supercapacitors is reported. The Mo sites in MoO3 are intentionally modulated at the atomic level through sulfur doping strategy, where sulfur could be introduced into the MoO6 octahedron along with oxygen vacancies to intrinsically tune the bond environment around Mo sites and thus boost the charge storage kinetics. Abstract Asymmetric supercapacitors (ASCs) are emerging as a new class of energy storage devices that could potentially meet the increasing power and energy demand for next‐generation portable and flexible electronics. Yet, the energy density of ASC is severely limited by the low capacitance of the anode side, which commonly uses the carbon‐based nanomaterials. Here, the demonstration of sulfur‐doped MoO3−x nanobelts (denoted as S‐MoO3−x) as the anode for high‐performance fiber‐shaped ASC are reported. The Mo sites in MoO3 are intentionally modulated at the atomic level through sulfur doping, where sulfur could be introduced into the MoO6 octahedron to intrinsically tune the covalency character of bonds around Mo sites and thus boost the charge storage kinetics of S‐MoO3−x. Moreover, the oxygen defects are occurring along with sulfur‐doping in MoO3, enabling efficient electron transport. As expected, the fiber‐shaped S‐MoO3−x achieves outstanding capacitance with good rate capability and long cycling life. More impressively, the fiber‐shaped ASC based on S‐MoO3−x anode delivers extremely high volumetric capacitance of 6.19 F cm−3 at 0.5 mA cm−1, which makes it promising as one of the most attractive candidates of anode materials for high‐performance fiber‐shaped ASCs.

Direct Imprinting of Quasi‐3D Nanophotonic Structures into Colloidal Quantum‐Dot Devices

By Xin Tang, Menglu Chen, Matthew M. Ackerman, Christopher Melnychuk, Philippe Guyot‐Sionnest from Wiley: Advanced Materials: Table of Contents. Published on Jan 20, 2020.

The direct fabrication of functional quasi‐3D nanophotonic structures into colloidal quantum dots (CQDs) films is demonstrated by one‐step imprinting with well‐controlled precision in both vertical and lateral directions. Functional optical structures on CQDs or within CQDs are fabricated without degrading the optical and electrical properties of CQDs. Abstract Three‐dimensional (3D) subwavelength nanostructures have emerged and triggered tremendous excitement because of their advantages over the two‐dimensional (2D) counterparts in fields of plasmonics, photonic crystals, and metamaterials. However, the fabrication and integration of 3D nanophotonic structures with colloidal quantum dots (CQDs) faces several technological obstacles, as conventional lithographic and etching techniques may affect the surface chemistry of colloidal nanomaterials. Here, the direct fabrication of functional quasi‐3D nanophotonic structures into CQD films is demonstrated by one‐step imprinting with well‐controlled precision in both vertical and lateral directions. To showcase the potential of this technique, diffraction gratings, bilayer wire‐grid polarizers, and resonant metal mesh long‐pass filters are imprinted on CQD films without degrading the optical and electrical properties of CQD. Furthermore, a dual‐diode CQD detector into an unprecedented mid‐wave infrared two‐channel polarization detector is functionalized by embedding an imprinted bilayer wire‐grid polarizer within the CQDs. The results show that this approach offers a feasible pathway to combine quasi‐3D nanostructures with colloidal materials‐based optoelectronics and access a new level of light manipulation.

Lithium‐Battery Anode Gains Additional Functionality for Neuromorphic Computing through Metal–Insulator Phase Separation

By Juan Carlos Gonzalez‐Rosillo, Moran Balaish, Zachary D. Hood, Neel Nadkarni, Dimitrios Fraggedakis, Kun Joong Kim, Kaitlyn M. Mullin, Reto Pfenninger, Martin Z. Bazant, Jennifer L. M. Rupp from Wiley: Advanced Materials: Table of Contents. Published on Jan 20, 2020.

Lithium titanates, originally developed as Li‐ion battery anode materials, are proposed here as a new memristive‐based neuromorphic computing hardware. By controlling the lithiation degree and using ex‐ and in‐operando spectroscopy, a switching mechanism in which the metal–insulator transition results from electrically driven phase separation of Li4Ti5O12 and Li7Ti5O12 is proposed through a theoretical framework based on nonequilibrium thermodynamics. Abstract Specialized hardware for neural networks requires materials with tunable symmetry, retention, and speed at low power consumption. The study proposes lithium titanates, originally developed as Li‐ion battery anode materials, as promising candidates for memristive‐based neuromorphic computing hardware. By using ex‐ and in operando spectroscopy to monitor the lithium filling and emptying of structural positions during electrochemical measurements, the study also investigates the controlled formation of a metallic phase (Li7Ti5O12) percolating through an insulating medium (Li4Ti5O12) with no volume changes under voltage bias, thereby controlling the spatially averaged conductivity of the film device. A theoretical model to explain the observed hysteretic switching behavior based on electrochemical nonequilibrium thermodynamics is presented, in which the metal‐insulator transition results from electrically driven phase separation of Li4Ti5O12 and Li7Ti5O12. Ability of highly lithiated phase of Li7Ti5O12 for Deep Neural Network applications is reported, given the large retentions and symmetry, and opportunity for the low lithiated phase of Li4Ti5O12 toward Spiking Neural Network applications, due to the shorter retention and large resistance changes. The findings pave the way for lithium oxides to enable thin‐film memristive devices with adjustable symmetry and retention.

Lithium‐Ion Battery Separators for Ionic‐Liquid Electrolytes: A Review

By Candice F. J. Francis, Ilias L. Kyratzis, Adam S. Best from Wiley: Advanced Materials: Table of Contents. Published on Jan 20, 2020.

Separators with different processing methods, polymers, additives, and different ionic liquid (IL) electrolytes are reviewed, specifically, separator morphology and ionic conductivity with IL electrolyte. A compatible separator must be developed before ionic liquid electrolytes can be used in commercial lithium‐ion batteries. The challenge of a suitable separator for IL electrolytes is not solved yet. Abstract Ionic liquids (ILs) are widely studied as a safer alternative electrolyte for lithium‐ion batteries. The properties of IL electrolytes compared to conventional electrolytes make them more thermally stable, but they also have poor wetting with commercial separators. In a lithium‐ion battery, the electrolyte should completely wet out the separator and electrodes to reduce the cell internal resistance. Investigations of cell materials with IL electrolytes have shown that the wetting issues in IL–electrolyte cells are most likely due to poor separator compatibility, not electrode compatibility. A compatible separator must be developed before IL electrolytes can be used in commercial lithium‐ion batteries. Herein, separators for IL electrolytes, including commercial and novel separators, are reviewed. Separators with different processing methods, polymers, additives, and different IL electrolytes are considered. Collated, the separator studies show a strong correlation between ionic conductivity and membrane porosity, even more than the electrolyte type. The challenge of a suitable separator for IL electrolytes is not solved yet. Herein, it is revealed that a separator for IL electrolytes will most likely require a combination of high thermal and mechanical stability polymer, ceramic additives, and an optimized manufacturing process.

Structural‐Phase Catalytic Redox Reactions in Energy and Environmental Applications

By Nasir Uddin, Huayang Zhang, Yaping Du, Guohua Jia, Shaobin Wang, Zongyou Yin from Wiley: Advanced Materials: Table of Contents. Published on Jan 20, 2020.

A library of structural phase engineering materials is presented and carefully reviewed, highlighting first the key progress of electrochemical processes in energy conversion, then photochemical and photoelectrochemical processes, and finally the three catalytic processes in environmental decontamination. Finally, the research gap and future promise in this field are highlighted. Abstract The structure–property engineering of phase‐based materials for redox‐reactive energy conversion and environmental decontamination nanosystems, which are crucial for achieving feasible and sustainable energy and environment treatment technology, is discussed. An exhaustive overview of redox reaction processes, including electrocatalysis, photocatalysis, and photoelectrocatalysis, is given. Through examples of applications of these redox reactions, how structural phase engineering (SPE) strategies can influence the catalytic activity, selectivity, and stability is constructively reviewed and discussed. As observed, to date, much progress has been made in SPE to improve catalytic redox reactions. However, a number of highly intriguing, unresolved issues remain to be discussed, including solar photon‐to‐exciton conversion efficiency, exciton dissociation into active reductive/oxidative electrons/holes, dual‐ and multiphase junctions, selective adsorption/desorption, performance stability, sustainability, etc. To conclude, key challenges and prospects with SPE‐assisted redox reaction systems are highlighted, where further development for the advanced engineering of phase‐based materials will accelerate the sustainable (active, reliable, and scalable) production of valuable chemicals and energy, as well as facilitate environmental treatment.

Tue 04 Feb 14:30: Twisted orbital integrals and irreducible components of affine Deligne-Lusztig varieties

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Twisted orbital integrals and irreducible components of affine Deligne-Lusztig varieties

Affine Deligne-Lusztig varieties (ADLV) naturally arise in the study of Shimura varieties and Rapoport-Zink spaces; their irreducible components give rise to an interesting class of cycles on the special fiber of Shimura varieties. In a joint work with Y. Zhu, we give a description of the top-dimensional irreducible components of ADLV ’s modulo the action of a natural symmetry group, verifying a conjecture of M. Chen and X. Zhu. In a work in progress with X. He and Y. Zhu, we use the previous result to obtain a description of the irreducible components of the basic locus of certain Shimura varieties in terms of a class set for an inner form of the structure group, generalizing classical results of Deuring and Serre. A key input for our approach is an analysis of certain twisted orbital integrals using techniques from local harmonic analysis.

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Understanding the activity of Co‐N4‐xCx in atomic metal catalysts for oxygen reduction catalysis

By Xiangdong Yao, Qin Yang, Yi Jia, Fenfei Wei, Linzhou Zhuang, Dongjiang Yang, Jizi Liu, Xin Wang, Sen Lin, Pei Yuan from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 20, 2020.

Atomic metal catalysis (AMC) provides an effective way to enhance activity for oxygen reduction reaction, especially, atomic cobalt anchored on nitrogen‐doped carbon materials have been extensively reported. The carbon‐hosted Co‐N 4 structure was widely considered as the active sites, however, it is very rare to investigate the activity of Co partially coordinated with N, e.g. Co‐N 4‐x C x . Herein, we investigate the activity of Co‐N 4‐x C x with tunable coordination environment as the active sites for oxygen reduction reaction (ORR) catalysis. The defect (di‐vacancies) on carbon is essential for the formation of Co‐N 4‐x C x . N species play two important roles in promoting the intrinsic activity of atomic metal catalyst, e.g. N coordinated with Co to manipulate the reactivity through the modification of electronic distribution and N helped to trap more Co to increase the number of active sites. The clear identification of the role of defect and N in tunable interaction with certain atomic Co site for ORR may provide the principles for rational design of atomic metal electrocatalysts.

Towards Long‐Term Photostability of Novel Nickel Hydroxide/BiVO4 Photoanodes via in‐situ Catalyst Tuning

By Lei Wang, Rui-Ting Gao, Dan He, Lijun Wu, Kan Hu, Xianhu Liu, Yiguo Su from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 20, 2020.

Increasing long‐term photostability of BiVO 4 photoanode is an important issue for solar water splitting, NiOOH oxygen evolution catalyst (OEC) has a fast water oxidation kinetics compared to FeOOH OEC.  However, it generally shows a relatively lower photoresponse and poor stability compared to FeOOH due to the more substantial interface recombination at the NiOOH/ BiVO 4 junction. In this work, we utilize a feasible plasma etching approach to reduce both interface/surface recombination at NiOOH/ BiVO 4 and NiOOH/electrolyte junctions. Further, adding Fe 2+ into the borate buffer electrolyte alleviates the active but unstable character of etched‐NiOOH/BiVO 4 , leading to an outstanding oxygen evolution over 200 h. The improved charge transfer and photostability can be attributed to the active defects and a mixture of NiOOH/NiO/Ni in OEC induced by plasma etching treatment. Metallic Ni acts as the ion source for the in‐situ generation of the NiFe OEC over long‐term durability.

Thu 02 Apr 16:30: Title: How Language Began: A Peircean Approach to Language Evolution There will be a tea and coffee reception from 4pm.

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Title: How Language Began: A Peircean Approach to Language Evolution

Abstract: In this talk I will discuss on-going work on the semeiotic origins of human language, based on archaeological evidence on Homo erectus culture, especially the ergology of this hominin species. I will argue that the core of human language is the productive, cultural generation of symbols. While all animals use signs – mainly indexes and icons – humans, due to their larger brains – are the most effective generators of symbols. The number and complexity of human symbols entails the “universal grammar” and “speculative grammars” of the 13th century Modistae and the 19th/20th century work of C.S. Peirce, including important logical principles, e.g. Peirce’s “reduction theorem” which predicts that no predicate in any language can have more than three basic arguments (i.e. more than a valency of 3 – without combining additional predicates). The focus will be on the archaeological record, however, and the strong evidence that erectus’s brain was modern in most essential respects, as shown by their symbolization in tool construction, their ocean travels, and their settlement patterns. One thesis of this work is that no special “language organ” is or was required for language to emerge and that, as Everett (2012, 2017, and 2018) argue, language is a cultural-cognitive tool that is not directly genetic, but an invented cultural tool, underwritten by the human brain’s general cognitive power.

There will be a tea and coffee reception from 4pm.

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Wed 19 Feb 16:30: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Title to be confirmed

Abstract not available

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Synthesis of Anisotropic ZnSe Nanorods with Zinc‐Blende Crystal Structure

By Jiajia Ning, Stephen V. Kershaw, Andrey L. Rogach from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 20, 2020.

Compared with the well explored cadmium based one‐dimensional nanorods (NRs), it is still a big challenge to produce heavy‐metal free II‐VI semiconductor analogues with a controlled size, shape and crystal structure. Herein, we report a synthetic strategy towards ZnSe NRs with a zinc‐blende crystal structure, where use of the anisotropic nuclei produced via a high temperature selenium injection favors anisotropic growth. Elongated ZnSe NRs were produced from anisotropic ZnSe nuclei, while spherical ZnSe nanocrystals were obtained starting from isotropic nuclei. The different free energy at (111) and (220) planes in anisotropic ZnSe nuclei induces the anisotropic growth for ZnSe NRs along direction. Proper choice of the capping ligand (1‐dodecanethiol) has an important implication for the formation of anisotropic ZnSe nuclei, and has also allowed us to control the diameter of the final ZnSe NRs via limiting the growth of the (220) crystal plane of anisotropic ZnSe nuclei.

Emerging Cubic Chirality in γCD‐MOF for Fabricating Circularly Polarized Luminescent Crystalline Materials and Size Effect

By Liangyu Hu, Kun Li, weili Shang, Xuefeng Zhu, Minghua Liu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 20, 2020.

As an important chiral MOFs, the chiral feature of γCD‐MOF, especially the emergent cubic void was not unveiled so far. Herein, through the host‐guest interaction between γCD‐MOF and achiral luminophores with different charges and sizes, we revealed the unique cubic chirality of the emerging void in γCD‐MOF as well as a size effect on CPL induction for the first time. Numerous achiral luminophores could be integrated into γCD‐MOF and emitted significantly boosted circularly polarized luminescence. While the small sized luminophores preferred to be loaded into the intrinsic void of γCD, the large ones were selectively encapsulated into the cubic void. Interestingly, when the size of the guest luminophores was close to the cubic size, it showed determined and strong negative CPL. Otherwise, either positive or negative CPL was induced. This work not only showed an insightful understanding of the emergent cubic chirality of γCD‐MOF, but also provided a general platform for the preparation of crystalline CPL materials.

Thu 05 Mar 14:30: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Title to be confirmed

Abstract not available

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Thu 13 Feb 14:30: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Title to be confirmed

Abstract not available

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C‐C bond formation in syngas conversion over Zn sites grafted on ZSM‐5

By Yuxiang Chen, Ke Gong, Feng Jiao, Xiulian Pan, Guangjin Hou, Rui Si, Xinhe Bao from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 20, 2020.

Despite significant progress achieved in Fischer‐Tropsch synthesis (FTS) technology, the selectivity control remains a challenge in syngas conversion. Herein, we demonstrate that zinc ion‐exchanged ZSM‐5 steers syngas conversion toward ethane with a selectivity in hydrocarbons (excluding CO 2 ) reaching as high as 87% at 20% CO conversion. NMR spectroscopy, X‐ray absorption spectroscopy and X‐ray fluorescence indicate that the selective pathway toward ethane is likely attributed to the Zn sites grafted within the ZSM‐5 pores. Quasi‐in‐situ solid state NMR detects C 2 species of acetyl [‐COCH 3 ] bonding with an oxygen, ethyl [‐CH 2 CH 3 ] bonding with a Zn site, and epoxyethane molecules adsorbing on a Zn site and a Brønsted acid site of the catalyst, respectively. These could provide some insights to C‐C bond formation during ethane formation. Interestingly, this selective reaction pathway toward ethane appears to be general, because a series of other Zn 2+ ion‐exchanged aluminosilicate zeolites with different topologies e.g. SSZ‐13, MCM‐22, ZSM‐12 all give predominantly ethane. By contrast, a physical mixture of ZnO‐ZSM‐5 favors formation of hydrocarbons beyond C 3+ . These results provide an important guidance for tuning the product selectivity in syngas conversion.

Programmable Assembly of Nano‐architectures through Designing Anisotropic DNA Origami Patches

By Mingyang Wang, Lizhi Dai, Jialin Duan, Zhiyuan Ding, Peng Wang, Zheng Li, Hang Xing, Ye Tian from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 20, 2020.

Programmable assembly of nanoparticles towards well‐defined architectures has attracted much attention due to their tailored properties resulted from coupling effects. However, ways to develop general and precise approaches to control the binding modes between nanoparticles (NPs) when fabricating designed architectures remain a significant challenge due to the difficulty in manipulating the accurate positions of the functional patches on the surface of NPs. Here, we develop a strategy to encage spherical NPs into pre‐designed octahedral DNA origami frames (DOFs) through DNA base‐pairings. The DOFs logically define the arrangements of functional patches in three dimensions, due to the programmability of DNA hybridization, and thus control the binding modes of the “caged” nanoparticle with designed anisotropy. By applying the node‐and‐spacer approach, which was widely used in crystal engineering to design coordination polymers, we are able to rationally design patchy NPs with lower symmetry encoded to assemble a series of nano‐architectures with high‐order geometries.

Controllable Synthesis of Graphdiyne Nanoribbons

By Weixiang Zhou, Han Shen, Yan Zeng, Yuanping Yi, Zicheng Zuo, Yongjun Li, Yuliang Li from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 20, 2020.

Graphdiyne nanoribbons with high chemical precision are of great significance for further understanding the intrinsic properties of graphdiyne and the relationship between structure and properties. However, the reliable synthesis of graphdiyne nanoribbons with chemical precision remains a blank and a significant challenge. Here we reported a facile method for fabrication of grahdiyne nanoribbons with uniform width through stepwise inter‐ and intramolecular Glaser‐Hay coupling reaction of ethynyl groups. The synthetic ribbons were interwoven into nanotextiles by π‐π stacking and were applied for protective coating of Li‐electrode in Li‐ion batteries, which efficiently suppressed the growth of the Li dendrites during cycling and prolonged the life span of Li‐metal batteries.

p‐ and m‐Phenylene Bridged Carbon Centred Diradicals with CAAC‐Scaffolds: Analogues of Thiele and Schlenk Hydrocarbons

By Anukul Jana, Avijit Maiti, Jessica Stubbe, Nicolás I. Neuman, Pankaj Kalita, Prakash Duari, Carola Schulzke, Vadapalli Chandrasekhar, Biprajit Sarkar from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 20, 2020.

Diradicals have been of tremendous interest for over a century ever since the first reports of p ‐ and m ‐phenylene‐bridged diphenylmethylradicals in 1904 by Thiele and 1915 by Schlenk. Herein, we report the first examples of cyclic(alkyl)(amino)carbene (CAAC)‐analogues of Thiele's hydrocarbon, a Kekulé diradical, and Schlenk's hydrocarbon, a non‐Kekulé diradical without using CAAC as a precursor. The CAAC analogue of Thiele's hydrocarbon has a singlet ground state, whereas the CAAC analogue of Schlenk's hydrocarbon contains two unpaired electrons. The latter was found to be in equilibrium with its dimer, which is formed by an intermolecular double head‐to‐tail dimerization. Our disclosed straightforward synthetic methodology is modular and can be extended for the generation of redox‐active organic compounds.

Single‐Atom‐Enzyme as Efficient Multiple Reactive Oxygen and Nitrogen Species Scavenger for Sepsis Management

By Jinsong Ren, Fangfang Cao, Lu Zhang, Yawen You, Lirong Zheng, Xiaogang Qu from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 20, 2020.

Sepsis, characterized by immoderate production of multiple reactive oxygen and nitrogen species (RONS), continues to cause high morbidity and mortality worldwide. Despite the progress made with nanozymes, the efficient antioxidant therapy that could fast eliminate all of these RONS remains challenging, owing largely to the specificity and low activity of exploited nanozymes. Herein, we report a novel single‐atom‐enzyme, Co/PMCS, featuring with atomically dispersed coordinatively unsaturated active Co‐porphyrin centers, can fast obliterate multiple RONS to alleviate sepsis. Co/PMCS can eliminate O2•‐ and H2O2 by mimicking superoxide dismutase, catalase and glutathione peroxidase, while remove •OH via the oxidative‐reduction cycle, exhibiting markedly higher activity than nanozymes. Notably, it can also scavenge •NO through the formation of nitrosyl‐metal complex, hardly accomplished by the current nanozymes. Eventually, it can reduce proinflammatory cytokine level, protect organs from damage and confer a distinct survival advantage to the infected sepsis mice, demonstrating a promising agent for antioxidative therapy.

“Self‐Lockable” Liquid‐Crystalline Diels‐Alder Dynamic Network Actuators with Room Temperature Programmability and Solution‐Reprocessability

By Zhichao Jiang, Yaoyu Xiao, Lu Yin, Li Han, Yue Zhao from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 20, 2020.

Novel main‐chain liquid crystalline polyesters were designed and synthesized to demonstrate liquid crystalline Diels‐Alder dynamic networks (LCDANs) for soft actuator applications. These materials exhibit unprecedented ease for actuator programming and reprocessing compared to existing liquid crystalline network (LCN) systems. Following cooling from around 125 o C, LCDANs can be deformed with aligned mesogens self‐locked at room temperature by slowly formed DA bonds, which allows for the making of solid 3D actuators capable of reversible shape transformation, and strip walker and wheel capable of light‐driven locomotion upon either thermally or optically induced order‐disorder phase transition. Any actuator can readily be erased at 125 o C and reprogrammed into a new one under ambient conditions. Moreover, LCDANs can be processed directly from melt (e.g. fiber drawing) and, being dissolvable in solution, from solution as well (e.g. casting tubular actuators), which cannot be achieved with liquid crystalline dynamic networks using exchangeable covalent bonds (vitrimers). The combined attributes of LCDANs are a significant progress toward developing easily programmable/processable LCN actuators.

Mon 27 Jan 13:00: Cambridge Design Partnership - Think Small: Embedded Software FTW! Food provided

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Cambridge Design Partnership - Think Small: Embedded Software FTW!

Cambridge Design Partnership is a multi-disciplinary design consultancy. Software engineers Tom Vajzovic and Jason Mashinchi talk about the unique opportunities and limitations of embedded software, as well as trends in in the embedded industry and lessons that may be more broadly applicable.

Food provided

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Wed 19 Feb 13:45: On the size of subsets of F_p^n without p distinct elements summing to zero

From All Talks (aka the CURE list). Published on Jan 20, 2020.

On the size of subsets of F_p^n without p distinct elements summing to zero

Let us fix a prime p. The Erdös-Ginzburg-Ziv problem asks for the minimum integer s such that any collection of s points in the lattice Z&Hatn contains p points whose centroid is also a lattice point in Z&Hatn. For large n, this is essentially equivalent to asking for the maximum size of a subset of F_p^n without p distinct elements summing to zero.

In this talk, we discuss a new upper bound for this problem for any fixed prime p\geq 5 and large n. Our proof uses the so-called multi-colored sum-free theorem which is a consequence of the Croot-Lev-Pach polynomial method, as well as some new combinatorial ideas.

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Tue 28 Jan 11:30: Stem Cells: It’s All About the Neighborhood Hosted by: Ben Simons & Emma Rawlins

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Stem Cells: It’s All About the Neighborhood

Abstract not available

Hosted by: Ben Simons & Emma Rawlins

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Tue 10 Mar 16:00: TBC

From All Talks (aka the CURE list). Published on Jan 20, 2020.

TBC

Abstract not available

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Tue 10 Mar 16:00: TBC

From All Talks (aka the CURE list). Published on Jan 20, 2020.

TBC

Abstract not available

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Tue 28 Apr 16:00: DUNE - Precision Neutrino Physics of the Future

From All Talks (aka the CURE list). Published on Jan 20, 2020.

DUNE - Precision Neutrino Physics of the Future

Abstract not available

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Tue 18 Feb 16:00: CMS HGCal upgrade

From All Talks (aka the CURE list). Published on Jan 20, 2020.

CMS HGCal upgrade

Abstract not available

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Tue 28 Jan 16:00: Anubis

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Anubis

Abstract not available

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Tue 11 Feb 16:00: TBC

From All Talks (aka the CURE list). Published on Jan 20, 2020.

TBC

Abstract not available

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Tue 19 May 16:00: Neutrino interactions and long-baseline oscillation experiments

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Neutrino interactions and long-baseline oscillation experiments

Abstract not available

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Mon 09 Mar 13:00: Hydrological networks and flow of the Greenland ice sheet

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Hydrological networks and flow of the Greenland ice sheet

Glaciers drain ice sheets by transporting ice from the interior to the coast where ice is discharged into the sea as icebergs. In Greenland, glaciers are flowing faster, posing a global risk of accelerated sea level rise. In this talk I report outcomes from the interdisciplinary RESPONDER project (www.erc-responder.eu), which is investigating hydrological networks and flow of the Greenland ice sheet. Using GPS -assisted drones with high accuracy, the team tracked meltwater pathways and found surface water to descend rapidly to the bed when supraglacial lakes are intercepted by extensional fractures forming along pre-existing structural weaknesses. We used a hot-water drill to gain access to the bed at specific targets, which included the shore of a rapidly draining lake, and the drained lake floor where a hydrological connection supplied a significant, but varying amount of surface water directly to the basal drainage system. With sensors deployed at the bed and within the ice, we observed the basal conditions that drive fast glacier flow.

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Thu 06 Feb 16:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Title to be confirmed

Abstract not available

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Mon 09 Mar 16:30: Striatal circuits underlying sensorimotor functions Host: Hugh Robinson

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Striatal circuits underlying sensorimotor functions

Abstract not available

Host: Hugh Robinson

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Mon 24 Feb 16:30: Title to be confirmed Host: Fabian Grabenhorst

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Title to be confirmed

Abstract not available

Host: Fabian Grabenhorst

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Mon 10 Feb 16:30: Title to be confirmed Host: Wolfram Schultz

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Title to be confirmed

Abstract not available

Host: Wolfram Schultz

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Mon 03 Feb 16:30: Title to be confirmed Host: Mate Lengyel

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Title to be confirmed

Abstract not available

Host: Mate Lengyel

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Mon 27 Jan 16:30: The mammalian circadian clock: genes, cells and circuits Host: Sue Jones

From All Talks (aka the CURE list). Published on Jan 20, 2020.

The mammalian circadian clock: genes, cells and circuits

Abstract not available

Host: Sue Jones

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Photoactivated Artificial Molecular Machines that Can Perform Tasks

By Stefano Corra, Massimiliano Curcio, Massimo Baroncini, Serena Silvi, Alberto Credi from Wiley: Advanced Materials: Table of Contents. Published on Jan 20, 2020.

Artificial molecular machines powered by light can nowadays be integrated in organized environments such that the molecular movements can be harnessed to execute a task. The resulting functional devices and materials can lead to radical innovation in catalysis, microfluidics soft robotics, medical diagnostics and therapy, and solar energy conversion. Abstract Research on artificial photoactivated molecular machines has moved in recent years from a basic scientific endeavor toward a more applicative effort. Nowadays, the prospect of reproducing the operation of natural nanomachines with artificial counterparts is no longer a dream but a concrete possibility. The progress toward the construction of molecular‐machine‐based devices and materials in which light irradiation results in the execution of a task as a result of nanoscale movements is illustrated here. After a brief description of a few basic types of photoactivated molecular machines, significant examples of their exploitation to perform predetermined functions are presented. These include switchable catalysts, nanoactuators that interact with cellular membranes, transporters of small molecular cargos, and active joints capable of mechanically coupling molecular‐scale movements. Investigations aimed at harnessing the collective operation of a multitude of molecular machines organized in arrays to perform tasks at the microscale and macroscale in hard and soft materials are also reviewed. Surfaces, gels, liquid crystals, polymers, and self‐assembled nanostructures are described wherein the nanoscale movement of embedded molecular machines is amplified, allowing the realization of muscle‐like actuators, microfluidic devices, and polymeric materials for light energy transduction and storage.

Soft Lattice and Defect Covalency Rationalize Tolerance of β‐CsPbI3 Perovskite Solar Cells to Native Defects

By Weibin Chu, Wissam A. Saidi, Jin Zhao, Oleg V. Prezhdo from Wiley: Angewandte Chemie International Edition: Table of Contents. Published on Jan 20, 2020.

Although all‐inorganic lead halide perovskite solar cells have shown tremendous improvement over the past few years, they are still inferior to the hybrid organic‐inorganic perovskites in the solar power conversion efficiency. Recently, a conceptually new β‐CsPbI 3 perovskite has demonstrated an impressive 18.4% efficiency combined with good thermodynamic stability at ambient conditions. We use ab initio non‐adiabatic molecular dynamics to show that native point defects in β‐CsPbI 3 are generally benign for non‐radiative charge recombination, regardless of whether they introduce shallow or deep trap states. Moreover, formation of new covalently bound species in the presence of defects slows down the recombination. These results indicate that halide perovskites do not follow the simple models used to explain defect‐mediated charge recombination in the conventional semiconductors. The strong tolerance of electron‐hole recombination against defects arises due to the softness of the perovskite lattice, which permits separation of electrons and holes upon defect formation, and allows only low‐frequency vibrations to couple to the electronic subsystem. Both factors decrease significantly the non‐adiabatic coupling and slow down the dissipation of electronic energy to heat. We suggest that a halide‐rich synthesis environment may further improve the efficiency, and propose that strong defect tolerance is general to metal halide perovskites because they exhibit much lower bulk moduli compared to the conventional semiconductors used in photovoltaic, photocatalytic, electrocatalytic, lasing, light‐emitting, detecting and other opto‐electronic devices.

Spaser Nanoparticles for Ultranarrow Bandwidth STED Super‐Resolution Imaging

By Zhaoshuai Gao, Jian‐Hua Wang, Pei Song, Bin Kang, Jing‐Juan Xu, Hong‐Yuan Chen from Wiley: Advanced Materials: Table of Contents. Published on Jan 20, 2020.

Super‐resolution microscopy, as a powerful tool of seeing abundant spatial details, typically can only distinguish a few distinct targets at a time due to the spectral crosstalk between fluorophores. Here, a narrow spectral linewidth (3.8 nm) particles named as spaser nanoparticles are introduced as a probe to realize ultranarrow bandwidth super‐resolution imaging, which can expect to eliminate the spectral crosstalk thoroughly. Abstract Super‐resolution microscopy, as a powerful tool of seeing abundant spatial details, typically can only distinguish a few distinct targets at a time due to the spectral crosstalk between fluorophores. Spaser (i.e., surface plasmon laser) nanoprobes, which confine lasing emission into nanoscale, offer an opportunity to eliminate such obstacle. Here, realized is narrow band stimulated emission depletion (STED) nanoscopy on spaser nanoparticles by collecting the coherent spasing signals. Demonstrated are the physics concept and feasibility of erasing spaser emission by using a depletion beam to suppress the population inversion, which lays the foundation of spaser‐based STED super‐resolution. Thanks to the small size (47 nm) and narrow spectral linewidth (3.8 nm) of the spaser nanoparticles, a 74 nm spatial resolution in STED imaging within an acquisition bandwidth of 10 nm is finally obtained. These spaser nanoparticles, if multiplexing with different wavelengths, in principle, allow for spectral‐multiplexed imaging, sensing, cytometry, and light operation of a large number of targets all at once.

Lateral 2D WSe2 p–n Homojunction Formed by Efficient Charge‐Carrier‐Type Modulation for High‐Performance Optoelectronics

By Jiacheng Sun, Yuyan Wang, Shaoqiang Guo, Bensong Wan, Lianqing Dong, Youdi Gu, Cheng Song, Caofeng Pan, Qinghua Zhang, Lin Gu, Feng Pan, Junying Zhang from Wiley: Advanced Materials: Table of Contents. Published on Jan 20, 2020.

A novel and facile electron doping of 2D WSe2 by cetyltrimethyl ammonium bromide (CTAB) is achieved to form a high‐quality lateral p–n homojunction with superior optoelectronic properties. The high switching light ratio (≈105), superior photoresponsivity (30 A W−1), and specific detectivity (over 1011 Jones) of the device demonstrate its promising applications for high‐sensitive photodetector and low‐power photoelectronic devices. Abstract As unique building blocks for next‐generation optoelectronics, high‐quality 2D p–n junctions based on semiconducting transition metal dichalcogenides (TMDs) have attracted wide interest, which are urgent to be exploited. Herein, a novel and facile electron doping of WSe2 by cetyltrimethyl ammonium bromide (CTAB) is achieved for the first time to form a high‐quality intramolecular p–n junction with superior optoelectronic properties. Efficient manipulation of charge carrier type and density in TMDs via electron transfer between Br− in CTAB and TMDs is proposed theoretically by density functional theory (DFT) calculations. Compared with the intrinsic WSe2 photodetector, the switching light ratio (Ilight/Idark) of the p–n junction device can be enhanced by 103, and the temporal response is also dramatically improved. The device possesses a responsivity of 30 A W−1, with a specific detectivity of over 1011 Jones. In addition, the mechanism of charge transfer in CTAB‐doped 2D WSe2 and WS2 are investigated by designing high‐performance field effect transistors. Besides the scientific insight into the effective manipulation of 2D materials by chemical doping, this work presents a promising applicable approach toward next‐generation photoelectronic devices with high efficiency.

Thu 05 Mar 16:00: Jet substructure and top-taggers for highly boosted tops

From All Talks (aka the CURE list). Published on Jan 20, 2020.

Jet substructure and top-taggers for highly boosted tops

We study, from the viewpoint of QCD , top taggers that exploit jet substructure for identifying highly boosted top quarks. To understand the problem we take the example of the CMS top tagger, one of the early standard methods introduced and used in experimental studies. We find that the tagger is IRC unsafe and modify it to make it amenable to our QCD studies while retaining the performance (signal significance) of the original CMS tagger. We then study the main factors that influence the performance of top taggers for high p_t top jets including the effects of radiation constraints imposed by the taggers on the signal and the QCD background, introduce new methods for top tagging, and highlight some directions for future studies.

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Large-area single-crystal AB-bilayer and ABA-trilayer graphene grown on a Cu/Ni(111) foil

By Rodney S. Ruoff from Nature Nanotechnology - Issue - nature.com science feeds. Published on Jan 20, 2020.

Nature Nanotechnology, Published online: 20 January 2020; doi:10.1038/s41565-019-0622-8

Large-area, high-quality AB-stacked bilayer and ABA-stacked trilayer graphene films have been achieved, with fine control of Ni content, on single-crystal Cu/Ni(111) alloy foils.

Regioselective magnetization in semiconducting nanorods

By Edward H. Sargent from Nature Nanotechnology - Issue - nature.com science feeds. Published on Jan 20, 2020.

Nature Nanotechnology, Published online: 20 January 2020; doi:10.1038/s41565-019-0606-8

A double-buffer-layer engineering strategy enables the selective growth of magnetic materials at specific locations on a wide variety of semiconducting nanorods.

Controlled transformation of skyrmions and antiskyrmions in a non-centrosymmetric magnet

By Yoshinori Tokura from Nature Nanotechnology - Issue - nature.com science feeds. Published on Jan 20, 2020.

Nature Nanotechnology, Published online: 20 January 2020; doi:10.1038/s41565-019-0616-6

Skyrmions and antiskyrmions are nanometric spin whirls with opposite topological charges. In the Heusler magnet Mn1.4Pt0.9Pd0.1Sn, modulations of the orientation and strength of an in-plane magnetic field induces the transformation from antiskyrmions to non-topological bubbles and skyrmions.

Single-molecule resonance Raman effect in a plasmonic nanocavity

By Yousoo Kim from Nature Nanotechnology - Issue - nature.com science feeds. Published on Jan 20, 2020.

Nature Nanotechnology, Published online: 20 January 2020; doi:10.1038/s41565-019-0614-8

Tip-enhanced Raman spectroscopy can provide chemical sensitivity at a single-molecule level. Measurements on individual molecules adsorbed on a thin salt layer unveil that components of the electric field perpendicular to the tip provide sensitivity to the symmetry of the vibrational modes of the molecule.

Single-molecule tautomerization tracking through space- and time-resolved fluorescence spectroscopy

By Guillaume Schull from Nature Nanotechnology - Issue - nature.com science feeds. Published on Jan 20, 2020.

Nature Nanotechnology, Published online: 20 January 2020; doi:10.1038/s41565-019-0620-x

Tautomerization, the interconversion between two constitutional isomers of a molecule, plays a major role in chemistry. The combination of hyper-resolved fluorescence microscopy with time-correlated measurements and spectral selection enables the identification and in-depth characterization of a tautomerization reaction within a single molecular switch.

Two layers are better than one

By Ayelet Vilan from Nature Materials - Issue - nature.com science feeds. Published on Jan 20, 2020.

Nature Materials, Published online: 20 January 2020; doi:10.1038/s41563-019-0588-9

Fullerene–triethylene glycol monomers are shown to form self-assembled bilayers on Au with an exchangeable upper layer. These structures are as versatile as thiol-based self-assembled monolayers while showing enhanced robustness.

Thiol-free self-assembled oligoethylene glycols enable robust air-stable molecular electronics

By Ryan C. Chiechi from Nature Materials - Issue - nature.com science feeds. Published on Jan 20, 2020.

Nature Materials, Published online: 20 January 2020; doi:10.1038/s41563-019-0587-x

Chemisorbed molecules combining glycol-ether moieties and fullerenes are shown to form uniform and air-stable self-assembled bilayers on coinage metals, and are amenable to versatile functionalization by in-place exchange of the top layer.

Protease-activated receptor signalling initiates α5β1-integrin-mediated adhesion in non-haematopoietic cells

By Daniel J. Müller from Nature Materials - Issue - nature.com science feeds. Published on Jan 20, 2020.

Nature Materials, Published online: 20 January 2020; doi:10.1038/s41563-019-0580-4

As in haematopoietic cells and platelets, agonist binding to protease-activated receptors PAR1 and PAR2 in non-haematopoietic cells also triggers signalling pathways that lead to α5β1-integrin-mediated cell adhesion.

Electronic structure of the parent compound of superconducting infinite-layer nickelates

By W. S. Lee from Nature Materials - Issue - nature.com science feeds. Published on Jan 20, 2020.

Nature Materials, Published online: 20 January 2020; doi:10.1038/s41563-019-0585-z

X-ray spectroscopy and density functional theory are used to show that the electronic structure of the parent compound of superconducting infinite-layer nickelates, while similar to the copper-based high-temperature superconductors, has significant differences.

Fatigue of graphene

By Tobin Filleter from Nature Materials - Issue - nature.com science feeds. Published on Jan 20, 2020.

Nature Materials, Published online: 20 January 2020; doi:10.1038/s41563-019-0586-y

Mechanical fatigue occurs under cyclic stress much lower than the tensile strength, but this has not been investigated for 2D materials. Here, graphene is found to have a fatigue life of 109 cycles.

Voltage decay and redox asymmetry mitigation by reversible cation migration in lithium-rich layered oxide electrodes

By Kisuk Kang from Nature Materials - Issue - nature.com science feeds. Published on Jan 20, 2020.

Nature Materials, Published online: 20 January 2020; doi:10.1038/s41563-019-0572-4

The use of high-energy-density lithium-rich layered-oxide electrodes in batteries is hindered by voltage decay on cycling. Improving the reversible cation migration by altering oxygen stacking is shown to suppress voltage decay and redox asymmetry in lithium-rich nickel manganese oxides.

Live cell single molecule tracking and localization microscopy of bioorthogonally labeled plasma membrane proteins

By Natalie Elia from RSC - Nanoscale latest articles. Published on Jan 20, 2020.

Nanoscale, 2020, Advance Article
DOI: 10.1039/C9NR08594G, Paper
Open Access Open Access
Andres I. König, Raya Sorkin, Ariel Alon, Dikla Nachmias, Kalyan Dhara, Guy Brand, Ofer Yifrach, Eyal Arbely, Yael Roichman, Natalie Elia
Visualizing the spatiotemporal organization of plasma membrane proteins at the nanoscale by combining live-cell single-molecule applications with direct fluorescent dye labeling via genetic code expansion and bioorthogonal chemistry.
To cite this article before page numbers are assigned, use the DOI form of citation above.
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Single Atom Array Mimic on Ultrathin MOF Nanosheets Boosts the Safety and Life of Lithium–Sulfur Batteries

By Yiju Li, Shuangyan Lin, Dandan Wang, Tingting Gao, Jianwei Song, Peng Zhou, Zhikun Xu, Zhenghao Yang, Ni Xiao, Shaojun Guo from Wiley: Advanced Materials: Table of Contents. Published on Jan 19, 2020.

A “single atom array mimic” on ultrathin metal–organic framework (MOF) nanosheets can be utilized in the bifunctional separator to simultaneously suppress Li dendrite growth and alleviate polysulfide shuttling. The assembled lithium–sulfur (Li–S) batteries with a bifunctional separator display high specific capacity and long‐term cyclic stability. Abstract The development of Li–S batteries is largely impeded by the growth of Li dendrites and polysulfide shuttling. To solve these two problems simultaneously, herein the study reports a “single atom array mimic” on ultrathin metal organic framework (MOF) nanosheet‐based bifunctional separator for achieving the highly safe and long life Li–S batteries. In the designed separator, the periodically arranged cobalt atoms coordinated with oxygen atoms (CoO4 moieties) exposed on the surface of ultrathin MOF nanosheets, “single atom array mimic”, can greatly homogenize Li ion flux through the strong Li ion adsorption with O atoms at the interface between anode and separator, leading to stable Li striping/plating. Meantime, at the cathode side, the Co single atom array mimic serves as “traps” to suppress polysulfide shuttling by Lewis acid‐base interaction. As a result, the Li–S coin cells with the bifunctional separator exhibit a long cycle life with an ultralow capacity decay of 0.07% per cycle over 600 cycles. Even with a high sulfur loading of 7.8 mg cm−2, an areal capacity of 5.0 mAh cm−2 can be remained after 200 cycles. Moreover, the assembled Li–S pouch cell displays stable cycling performance under various bending angles, demonstrating the potential for practical applications.

Mechanically and Electronically Robust Transparent Organohydrogel Fibers

By Jianchun Song, Shuo Chen, Lijie Sun, Yifan Guo, Luzhi Zhang, Shuliang Wang, Huixia Xuan, Qingbao Guan, Zhengwei You from Wiley: Advanced Materials: Table of Contents. Published on Jan 19, 2020.

Hydrogel fibers are continuously manufactured based on a unique physical and covalent hybrid crosslinking mechanism. Then, a portion of the water in the hydrogel fibers is replaced by glycerin to produce organohydrogel fibers. The resulting organohydrogel fibers not only have excellent antifreezing (5 months), and transparency, but also show robust mechanical and electrical properties. Abstract Stretchable conductive fibers are key elements for next‐generation flexible electronics. Most existing conductive fibers are electron‐based, opaque, relatively rigid, and show a significant increase in resistance during stretching. Accordingly, soft, stretchable, and transparent ion‐conductive hydrogel fibers have attracted significant attention. However, hydrogel fibers are difficult to manufacture and easy to dry and freeze, which significantly hinders their wide range of applications. Herein, organohydrogel fibers are designed to address these challenges. First, a newly designed hybrid crosslinking strategy continuously wet‐spins hydrogel fibers, which are transformed into organohydrogel fibers by simple solvent replacement. The organohydrogel fibers show excellent antifreezing (5 months), transparency, and stretchability. The predominantly covalently crosslinked network ensures the fibers have a high dynamic mechanical stability with negligible hysteresis and creep, from which previous conductive fibers usually suffer. Accordingly, strain sensors made from the organohydrogel fibers accurately capture high‐frequency (4 Hz) and high‐speed (24 cm s−1) motion and exhibit little drift for 1000 stretch–release cycles, and are powerful for detecting rapid cyclic motions such as engine valves and are difficult to reach by previously reported conductive fibers. The organohydrogel fibers also demonstrate potential as wearable anisotropic sensors, data gloves, soft electrodes, and optical fibers.

Ultrathin Ni(0)‐Embedded Ni(OH)2 Heterostructured Nanosheets with Enhanced Electrochemical Overall Water Splitting

By Lei Dai, Zhe‐Ning Chen, Liuxiao Li, Peiqun Yin, Zhengqing Liu, Hua Zhang from Wiley: Advanced Materials: Table of Contents. Published on Jan 19, 2020.

The heterostructured Ni/Ni(OH)2 nanosheets synthesized using a partial reduction strategy are used as an efficient multifunctional electrocatalyst for hydrogen evolution reaction, oxygen evolution reaction, and overall water splitting. This work opens up new opportunities in the rational design of cost‐effective and highly efficient multifunctional electrocatalysts for renewable energy conversion. Abstract The efficiency of splitting water into hydrogen and oxygen is highly dependent on the catalyst used. Herein, ultrathin Ni(0)‐embedded Ni(OH)2 heterostructured nanosheets, referred to as Ni/Ni(OH)2 nanosheets, with superior water splitting activity are synthesized by a partial reduction strategy. This synthetic strategy confers the heterostructured Ni/Ni(OH)2 nanosheets with abundant Ni(0)‐Ni(II) active interfaces for hydrogen evolution reaction (HER) and Ni(II) defects as transitional active sites for oxygen evolution reaction (OER). The obtained Ni/Ni(OH)2 nanosheets exhibit noble metal‐like electrocatalytic activities toward overall water splitting in alkaline condition, to offer 10 mA cm−2 in HER and OER, the required overpotentials are only 77 and 270 mV, respectively. Based on such an outstanding activity, a water splitting electrolysis cell using the Ni/Ni(OH)2 nanosheets as the cathode and anode electrocatalysts has been successfully built. When the output voltage of the electrolytic cell is 1.59 V, a current density of 10 mA cm−2 can be obtained. Moreover, the durability of Ni/Ni(OH)2 nanosheets in the alkaline electrolyte is much better than that of noble metals. No obvious performance decay is observed after 20 h of catalysis. This facile strategy paves the way for designing highly active non‐precious‐metal catalyst to generate both hydrogen and oxygen by electrolyzing water at room temperature.

Tue 11 Feb 14:15: D-ultrafilter monads

From All Talks (aka the CURE list). Published on Jan 18, 2020.

D-ultrafilter monads

The ultrafilter monad on sets is the codensity monad of the embedding of finite sets into Set, as proved by Kennison and Gildenhuys (1971). In this talk I will present a notion of D-ultrafilter on an object of a category K which generalizes the one of an ultrafilter on a set, where D is a cogenerator of K. Working in a complete, symmetric monoidal closed category, with a ‘nice cogenerator D, the corresponding D-ultrafilter monad is the codensity monad of the embedding of finitely presentable objects of K; moreover, it is a submonad of the double-dualization monad relative to D. This is illustrated by several examples, including commutative varieties and categories of posets and graphs. I will also discuss a generalization with the above embedding replaced by the embedding of a small full subcategory into a complete category, with A containing a cogenerating set of K. This is based on joint work with Jiri Adámek.

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Mon 17 Feb 15:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 18, 2020.

Title to be confirmed

Abstract not available

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Fri 06 Mar 16:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 18, 2020.

Title to be confirmed

Abstract not available

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Fri 28 Feb 16:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 18, 2020.

Title to be confirmed

Abstract not available

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Wed 12 Feb 16:30: Representations and subgroups of SL(4), with applications to physics

From All Talks (aka the CURE list). Published on Jan 18, 2020.

Representations and subgroups of SL(4), with applications to physics

The real 15-dimensional Lie group SL(4,R) contains pairwise disjoint subgroups GL(1,R), SU(2), SL(3,R) and SL(2,C). Apart from a technical difference in the real form, which can be adjusted by suitable multiplications by i, these are the same as the groups U(1), SU(2), SU(3) and SL(2,C) that are used in the standard model of particle physics. By removing the naive assumption that disjoint groups necessarily commute, it is possible to reproduce the entire group-theoretical foundation of particle physics inside SL(4,R).

The failure of commutativity provides a mechanism for explaining (some of) the unexplained parameters of the standard model. The representation theory of SL(4,R) provides a classification of particles that is coarser than the standard model, and thereby permits a more flexible view of the relationships between (for example) electron, proton and neutron.

Putting all this together with the local coordinate transformation group of general relativity, which is also isomorphic to SL(4,R), suggests ways in which the two theories may not be as incompatible as has been thought for the past 80 years or so.

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3D‐Printed Structure Boosts the Kinetics and Intrinsic Capacitance of Pseudocapacitive Graphene Aerogels

By Bin Yao, Swetha Chandrasekaran, Haozhe Zhang, Annie Ma, Junzhe Kang, Lei Zhang, Xihong Lu, Fang Qian, Cheng Zhu, Eric B. Duoss, Christopher M. Spadaccini, Marcus A. Worsley, Yat Li from Wiley: Advanced Materials: Table of Contents. Published on Jan 17, 2020.

A surface‐functionalized 3D‐printed graphene aerogel achieves a benchmark areal capacitance of 2195 mF cm−2 and an ultrahigh intrinsic capacitance of 309.1 µF cm−2. This work for the first time demonstrates the essential role of 3D‐printed porous structure for simultaneously boosting the kinetics and intrinsic capacitance of thick carbon electrodes with high mass loadings. Abstract The performance of pseudocapacitive electrodes at fast charging rates are typically limited by the slow kinetics of Faradaic reactions and sluggish ion diffusion in the bulk structure. This is particularly problematic for thick electrodes and electrodes highly loaded with active materials. Here, a surface‐functionalized 3D‐printed graphene aerogel (SF‐3D GA) is presented that achieves not only a benchmark areal capacitance of 2195 mF cm−2 at a high current density of 100 mA cm−2 but also an ultrahigh intrinsic capacitance of 309.1 µF cm−2 even at a high mass loading of 12.8 mg cm−2. Importantly, the kinetic analysis reveals that the capacitance of SF‐3D GA electrode is primarily (93.3%) contributed from fast kinetic processes. This is because the 3D‐printed electrode has an open structure that ensures excellent coverage of functional groups on carbon surface and facilitates the ion accessibility of these surface functional groups even at high current densities and large mass loading/electrode thickness. An asymmetric device assembled with SF‐3D GA as anode and 3D‐printed GA decorated with MnO2 as cathode achieves a remarkable energy density of 0.65 mWh cm−2 at an ultrahigh power density of 164.5 mW cm−2, outperforming carbon‐based supercapacitors operated at the same power density.

Wed 12 Feb 16:00: Feeling good, doing good: The potential of positive self-directed emotions to motivate prosociality

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Feeling good, doing good: The potential of positive self-directed emotions to motivate prosociality

Faced with global challenges, such as environmental degradation, social inequality, and discrimination against marginalized societal groups, identifying strategies to promote concern for the well-being of others and to encourage prosocial action is of high relevance. Caring about others and acting prosocially, however, takes up emotional and cognitive resources of which humans only have a limited amount. In this research I suggest that addressing the fundamental human need of establishing and maintaining a positive self-image may free up resources to engage in prosociality. I explore the potential of positive self-directed emotions in a suite of studies across two cultural contexts, the United States and Nigeria, looking at pro-environmental decision making, charitable giving and volunteering, as well as discrimination against marginalized societal groups.

Dr. Claudia R. Schneider received her PhD in Psychology from Columbia University, where she worked at the Centre for Research on Environmental Decisions, the Earth Institute. As an Ivy League Exchange Scholar she furthermore held a graduate research position at Princeton University. She currently works as a Research Associate at the Winton Centre for Risk and Evidence Communication and the Cambridge Social Decision-Making Laboratory, University of Cambridge. Her research explores avenues to address society-level social issues, such as climate change mitigation, intergroup conflict, and the balanced and transparent communication of evidence.

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Thu 13 Feb 16:00: Modelling energy dissipation at surfaces

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Modelling energy dissipation at surfaces

In the dawning age of sustainability, energy harvesting and (concomitant) dissipation at interfaces play a crucial role for processes that feed and fuel our modern societies. The most obvious dissipation channel is given by vibrations of the surface atoms (phonons), but also electron-hole pair excitations can play an important role. I am going to present some of our recent attempts to quantify the effects of both of these channels by further developing and applying computer simulations.

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Large Area Self‐Assembled Ultrathin Polyimine Nanofilms Formed at the Liquid–Liquid Interface Used for Molecular Separation

By Karishma Tiwari, Pulak Sarkar, Solagna Modak, Harwinder Singh, Sumit Kumar Pramanik, Santanu Karan, Amitava Das from Wiley: Advanced Materials: Table of Contents. Published on Jan 17, 2020.

Polyimine nanofilm composite membranes are prepared by transferring freestanding polyimine nanofilms onto polyacrylonitrile support and utilize them for selective separation of dyes and salts with molecular area cut‐off of ≈1.5 nm2 (equivalent to MWCO of ≈800 g mol−1). Nanofilms are made by self‐assembly of imine oligomers at water–xylene interface followed by water catalyzed reversible condensation polymerization. Abstract Separation membranes with higher molecular weight cut‐offs are needed to separate ions and small molecules from a mixed feed. The molecular sieving phenomenon can be utilized to separate smaller species with well‐defined dimensions from a mixture. Here, the formation of freestanding polyimine nanofilms with thicknesses down to ≈14 nm synthesized via self‐assembly of pre‐synthesized imine oligomers is reported. Nanofilms are fabricated at the water–xylene interface followed by reversible condensation of polymerization according to the Pieranski theory. Polyimine nanofilm composite membranes are made via transferring the freestanding nanofilm onto ultrafiltration supports. High water permeance of 49.5 L m‐2 h−1 bar−1 is achieved with a complete rejection of brilliant blue‐R (BBR; molecular weight = 825 g mol−1) and no more than 10% rejection of monovalent and divalent salts. However, for a mixed feed of BBR dye and monovalent salt, the salt rejection is increased to ≈18%. Membranes are also capable of separating small dyes (e.g., methyl orange; MO; molecular weight = 327 g mol−1) from a mixed feed of BBR and MO. Considering a thickness of ≈14 nm and its separation efficiency, the present membrane has significance in separation processes.

Fri 06 Mar 13:15: Towards predicting gene expression from DNA sequence

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Towards predicting gene expression from DNA sequence

Abstract not available

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Fri 21 Feb 13:15: Dissecting tissue mechanics in the early chicken embryo

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Dissecting tissue mechanics in the early chicken embryo

Abstract not available

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Fri 14 Feb 13:15: The mechanical regulation of brain development

From All Talks (aka the CURE list). Published on Jan 17, 2020.

The mechanical regulation of brain development

Abstract not available

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Fri 07 Feb 13:15: Repairing DNA damage in developing germ cells

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Repairing DNA damage in developing germ cells

Abstract not available

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Fri 31 Jan 13:15: Mechanics and mechanisms of tube morphogenesis

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Mechanics and mechanisms of tube morphogenesis

Abstract not available

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Thu 06 Feb 13:00: What is High-Performance Computing and why does it matter? Lunch provided

From All Talks (aka the CURE list). Published on Jan 17, 2020.

What is High-Performance Computing and why does it matter?

High-Performance Computing usually refers to scientific computing done at scale using supercomputers. Supercomputers touch all our lives through weather forecasting, cancer research, financial modelling, industrial design and more although few members of the public have heard of them. In this talk Rosemary will give an introduction to the industry and related technologies: Who owns the world’s supercomputers? What they are used for? What do the workloads look like? How does a supercomputer differ from any other large distributed system, datacenter or cloud? If you wanted to build a supercomputer, how would you go about it?

About Rosemary: Dr Rosemary Francis is the founder and CEO of Ellexus, the I/O profiling company. Rosemary obtained her PhD in Computer Architecture from the Cambridge University Computer Lab after studying computer science at Newnham in 2002. After working in the chip design industry, Rosemary founded Ellexus to help manage the complex tool chains needed for semiconductor design. Ellexus now works with high performance computing organisations around the world such as Qualcomm and Decode Genomics. Ellexus has solutions for monitoring application I/O, detecting file-system dependencies and optimising scientific workloads, both on-prem and in the cloud.

Lunch provided

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Tue 10 Mar 13:30: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Title to be confirmed

Abstract not available

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Tue 03 Mar 13:30: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Title to be confirmed

Abstract not available

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Tue 25 Feb 13:30: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Title to be confirmed

Abstract not available

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Tue 18 Feb 14:00: The optimal matching problem

From All Talks (aka the CURE list). Published on Jan 17, 2020.

The optimal matching problem

The optimal matching problem is about the rate of convergence in Wasserstein distance of the empirical measure of iid uniform points to the Lebesgue measure. We will start by reviewing the macroscopic behaviour of the matching problem and will then report on recent results on the mesoscopic behaviour in the thermodynamic regime. These results rely on a quantitative large-scale linearization of the Monge-Ampere equation through the Poisson equation. This is based on joint work with Michael Goldman and Felix Otto.

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Tue 18 Feb 13:30: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Title to be confirmed

Abstract not available

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Tue 11 Feb 14:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Title to be confirmed

Abstract not available

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Tue 04 Feb 14:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Title to be confirmed

Abstract not available

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Tue 28 Jan 13:30: TBC

From All Talks (aka the CURE list). Published on Jan 17, 2020.

TBC

Abstract not available

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Wed 19 Feb 16:00: An arithmetic count of rational plane curves

From All Talks (aka the CURE list). Published on Jan 17, 2020.

An arithmetic count of rational plane curves

A rational plane curve of degree d is a polynomial map from the line to the plane of degree d. There are finitely many such curves passing through 3d-1 points, and the number of them is independent of (generically) chosen points over the complex numbers. The problem of determining these numbers was solved by Kontsevich with a recursive formula with connections to string theory. Over the real numbers, one can obtain a fixed number by weighting real rational curves by their Welschinger invariant, and work of Solomon identifies this invariant with a local degree. It is a feature of A1-homotopy theory that analogous real and complex results can indicate the presence of a common generalization, valid over a general field. For generically chosen points with coordinates in chosen fields, we give such a generalization, providing an arithmetic count of rational plane curves over fields of characteristic not 2 or 3. This is joint work with Jesse Kass, Marc Levine, and Jake Solomon.

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Mon 24 Feb 13:00: How mixed is the ocean mixed layer?

From All Talks (aka the CURE list). Published on Jan 17, 2020.

How mixed is the ocean mixed layer?

Abstract not available

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Fri 14 Feb 14:00: Resonant Ultrasound Spectroscopy: characterisation of elastic and anelastic behaviour of metals, ceramics and functional oxides associated with ferroic, multiferroic and normal-superconductor phase transitions

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Resonant Ultrasound Spectroscopy: characterisation of elastic and anelastic behaviour of metals, ceramics and functional oxides associated with ferroic, multiferroic and normal-superconductor phase transitions

Resonant ultrasound spectroscopy (RUS) has proved to be a powerful method for routine investigation of the elastic and anelastic properties of small polycrystalline or single crystal samples of metals, minerals and functional oxides. The ideal shape is a rectangular parallelepiped with edge dimensions in the range 1-5 mm. This is placed lightly between two piezoelectric transducers, one of which stimulates natural acoustic resonances in the frequency range 0.1 – 1.2 MHz and the second of which detects them. Elastic moduli which determine each individual resonance mode scale with f2 and the acoustic loss is determined as the inverse mechanical quality factor, Q-1 = f/f, where f is the resonance frequency and f is its width at half maximum height. Because no glue is required to keep the sample in place, it is easy to design instruments in which RUS spectra can be collected over wide temperature intervals and with the possibility of adding simultaneous electric and/or magnetic fields. The main instrument in Cambridge uses a cryogen-free Oxford Instruments Teslatron to access temperatures down to 2 K with an external magnetic field of up to 14 Teslas. The high temperature instruments allow routine data collection at temperatures up to 1200 C.

Applications include the quantitative determination of bulk and shear moduli of ceramics and metal alloys and the use of characteristic Debye-like loss behaviour to detect, for example, hydrogen in steel. The main application in Cambridge has been to investigate the role and dynamics of strain coupling arising at phase transitions, which may be ferroelectric, (anti)ferromagnetic, ferroelastic, multiferroic, relaxor, Jahn-Teller, superconducting, etc. Examples of the methodology and overall approach will be given of the elastic and anelastic behaviour associated with phase transitions in a number of materials, including (Ca,Sr)TiO3 perovskites, the multiferroic perovskite GdMnO3, the helical magnet Cu2SeO3 and the unconventional superconductor, Ba(Fe0.957Co0.043)2As2.

Review article: Journal of Physics: Condensed Matter 26, 263201 (2015)

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Mon 03 Feb 15:00: Variations on Gehring’s lemma

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Variations on Gehring’s lemma

The classical Gehring’s lemma asserts that the reverse Hölder inequality is an open ended condition. This is relevant, for instance, in the regularity theory of elliptic PDEs, the higher gradient integrability of a solution being a prototypical example of the phenomenon. In this talk, I will discuss some new variants of Gehring’s lemma and its applications with focus on time dependent PDEs and non-local problems.

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Wed 12 Feb 14:15: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Title to be confirmed

Abstract not available

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Thu 12 Mar 15:00: Systematic Rateless Coding for Efficient Data Transport in Data Centres

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Systematic Rateless Coding for Efficient Data Transport in Data Centres

Abstract: The talk is about SCDP , a novel, general purpose data transport protocol for data centres that, in contrast to all other protocols proposed to date, natively supports one-to-many and many-to-one data communication, which is extremely common in modern data centres. SCDP does so without compromising on efficiency for short and long unicast flows. SCDP achieves this by integrating RaptorQ codes with receiver-driven data transport, in-network packet trimming and Multi-Level Feedback Queuing (MLFQ); (1) RaptorQ codes enable efficient one-to-many and many-to-one data transport; (2) on top of RaptorQ codes, receiver-driven flow control, in combination with in-network packet trimming, enable efficient usage of network resources as well as multi-path transport and packet spraying for all transport modes. Incast and Outcast are eliminated; (3) the systematic nature of RaptorQ codes, in combination with MLFQ , enable fast, decoding-free completion of short flows. We extensively evaluate SCDP in a wide range of simulated scenarios with realistic data centre workloads. For one-to-many and many-to-one transport sessions, SCDP performs significantly better compared to NDP . For short and long unicast flows, SCDP performs equally well or better compared to NDP .

Bio: Mohammed Alasmar received his Ph.D from the Department of Informatics, University of Sussex, in October 2019. His research is about designing and implementing robust data transport in data centres, with a focus on distributed storage systems. Since November 2018, he has been working as a Cloud Engineer at MAVIS Broadcast Ltd in Brighton, UK.

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Thu 12 Mar 16:00: Title to be confirmed

From All Talks (aka the CURE list). Published on Jan 17, 2020.

Title to be confirmed

Abstract not available

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