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An isotropic-porous, cell-fitting, thermogenetics-based chemokine CXCL12 generator is described as a B-cell-dependent intraperitoneal immunotherapy that can trigger intraperitoneal anti-tumor immunity against metastatic disseminated tumor cell to assuage peritoneal effusion and peritoneal metastasis. Unexpectedly, the peritoneal cavity B cell subset is identified as playing a key role in exogenous antigen presentation and presenting a unique transcriptional signature.

Abstract

During cancer peritoneal metastasis (PM), conventional antigen-presenting cells (dendritic cells, macrophages) promote tumorigenesis and immunosuppression in peritoneal cavity. While intraperitoneal immunotherapy (IPIT) has been used in clinical investigations to relieve PM, the limited knowledge of peritoneal immunocytes has hindered the development of therapeutic IPIT. Here, a dendritic cell-independent, next-generation IPIT is described that activates peritoneal cavity B (PerC B) cell subsets for intraperitoneal anti-tumor immunity via exogenous antigen presentation. The PerC B-cell-involved IPIT framework consists of an isotropic-porous, cell-fitting, thermogenetics-based CXCL12 generator. Such nanoscale thermal-confined generator can programmatically fine-tune the expression of CXCL12 to recruit disseminated tumor cells (DTCs) through CXCL12-CXCR4 axis while avoiding cytokine storm, subsequently release DTC-derived antigen to trigger PerC B-cell-involved immunity. Notably, antigen-presenting B-cell cluster, expressing the regulatory signaling molecules Ptpn6, Ms4a1, and Cd52, is identified playing the key role in the IPIT via single-cell RNA sequencing. Moreover, such IPIT availably assuages peritoneal effusion and PM in an orthotopic gastric cancer and metastatic model. Overall, this work offers a perspective on PerC B-cell-involved antigen-presenting in intraperitoneal immunity and provides a configurable strategy for activating anti-DTC immunity for next-generation IPIT.

Title tbc

Abstract not available

• Speaker: Peter Varju (University of Cambridge)
• Wednesday 05 March 2025, 13:30-15:00
• Venue: MR4, CMS.
• Series: Discrete Analysis Seminar; organiser: Julia Wolf.

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A single-peak stretchable BPLC laser is fabricated based on partially and fully crosslinked networks due to the slow variation of lattice orientation under small strains. The laser exhibits a tuning range of 44.429 nm at 32% strain, providing stable output over a broad- temperature range with 3D circularly polarized emission under small strains, presenting the potential applications in 3D mechanical perception.

Abstract

Blue phase liquid crystal (BPLC) lasers exhibit exceptional optical quality and tunability to external stimuli, holding significant promise for innovative developments in the field of flexible optoelectronics. However, there remain challenges for BPLC elastomer (BPLCE) lasers in maintaining good optical stability during stretching and varying temperature conditions. In this work, a stretchable laser is developed based on a well-designed BPLCE with a combination of partially and fully crosslinked networks, which can output a single-peak laser under small deformation (44.429 nm lasing shift at 32% strain) and a broad-temperature range (from −20 to 100 °C). The superior performance can be attributed to the nonlinear 3D asymmetric deformation exhibited by the BPI lattice during stretching, particularly at low deformation rates below 40% strain, which effectively maintains the stability of the body-centered cubic structure (with the maximum strain of this BPLCE up to 220%). Moreover, the BPLCE exhibits excellent thermal stability over a temperature range from −180 to 70 °C with a stopband shift of less than ±10 nm. As a proof-of-concept, the application of BPLCE laser for morphology sensing and 3D mechanical perception is demonstrated, which paves the way for potential applications of flexible optoelectronics.

In heterodimeric NBSSe, the NBS/NBSe radical pair formation in the co-excited NBSSe * after intramolecular electron transfer successfully converts type II into type I photodynamic pathway on a traditional type II photosensitizer NBSe of high reactive oxygen species yield. Incorporating electron-rich BSA further promotes O2 -· generation and photostability of this radical generator via recycling radicals, with an efficient tumor targeting capability for BSA@NBSSe.

Abstract

Photodynamic therapy (PDT) using traditional type II photosensitizers (PSs) has been limited in hypoxic tumors due to excessive oxygen consumption. The conversion from type II into a less oxygen-dependent type I PDT pathway has shown the potential to combat hypoxic tumors. Herein, the design of a heterodimeric PS, NBSSe, by conjugating a widely used type I PS NBS and a type II PS NBSe via molecular dimerization, achieving the aggregation-regulated efficient type I photodynamic conversion for the first time is reported. Electrochemistry characterizations and theoretical calculations elucidate that NBSSe tends to form a S+·/Se−· radical pair via intramolecular electron transfer in the co-excited NBSSe * aggregate, realizing 7.25-fold O2 −· generation compared to NBS and 80% suppression of 1O2 generation compared to NBSe. The enhanced O2 −· generation of NBSSe enables excellent anti-hypoxia PDT efficiency and inhibition of pulmonary metastasis. Additionally, the incorporation of electron-rich bovine serum albumin accelerates the recycling of cationic PS radical NBSSe+· , further boosting photostability and O2 −· generation. The resultant BSA@NBSSe nanoparticles demonstrate successful tumor-targeting PDT capability. This work provides an appealing avenue to convert ROS generation from the type II pathway to the type I pathway for efficient cancer phototherapy in hypoxia.

Inspired by sweeping robots, a Mg@PLGA@PEI microswimmer capable of cleaning off deleterious disease triggers is designed for the active therapy of ulcerative colitis. The self-driven ability endows the microswimmer with augmented contact probability with surrounding disease triggers, which contributes to enhanced disease triggers removal efficiency, promising to achieve precise control of the inflammatory storms of ulcerative colitis.

Abstract

Overproduction of pathogenic cell-free DNA (cfDNA) and reactive oxygen species (ROS) plays crucial roles in the onset and perpetuation of ulcerative colitis (UC). Inspired by sweeping robots, a magnesium@polylactic acid-glycolic acid copolymer@polyethylenimine (Mg@PLGA@PEI) microswimmer capable of cleaning off deleterious disease triggers along its path of progress is designed. Mg@PLGA@PEI is successfully synthesized by adopting a core-shell structure with a small opening which allows for Mg-water reaction. The distinctive motility performance resulting from sustained detachment of the produced hydrogen not only contributes to strengthened hydrogen diffusion concomitant with potentiated ROS neutralization, but also facilitates the contacting probability with microenvironmental cfDNA and thus enhances the DNA binding efficiency. By integrating these merits, the developed Mg@PLGA@PEI confers desirable curative efficacy in a classical DSS-induced acute colitis mouse model. Enema administration of Mg@PLGA@PEI microswimmers substantially alleviates the manifestations related to UC, as evidenced by the body weight recovery, colon length retention, colon tissue protection, and attenuated intestinal inflammation, which is attributed to the active scavenging of cfDNA and ROS. This work provides a paradigm for a drug-free strategy competent in spontaneously eliminating causative triggers with minimal side effects, which presents a promising alternative for the active therapy of UC or other cfDNA- and ROS-related diseases in the clinic.

Cycloolefin copolymers bearing hydroxyl, ester, and adamantanyl side groups are synthesized. Upon dispersing various phosphors into this polymer matrix, the resultant composites exhibit full-color room temperature phosphorescence with lifetimes of 249–590 ms, showing no obvious luminescence quenching in water, acid, alkalinous, reductive, and oxidative environments.

Abstract

Polymeric room temperature phosphorescence (RTP) materials have been well developed and utilized in various fields. However, their fast thermo- and moisture-quenching behavior highly limit their applications in certain harsh environments. Therefore, the preparation of materials with thermo- and moisture-resistant phosphorescence is greatly attractive. Compared with common water-soluble polymers, cycloolefin copolymers (COC) show outstanding hydrophobicity and higher rigidity, even at elevated temperatures, being as a promising candidate to prepare phosphorescence materials with suppressed thermo- and moisture-quenching behavior. Herein, a type of COC bearing hydroxyl, ester, and adamantanyl side groups is synthesized. After dispersing various phosphors into this matrix, the resultant composites exhibit full-color RTP with lifetimes of 249–590 ms. Their luminescence does not show obvious quenching in water, acid, alkalinous, reductive, and oxidative environments. In the presence of both rigid COC matrix and rigid phosphors, the corresponding composite displays high-temperature phosphorescence performance. Even at 378 K, the composite can emit phosphorescence with a lifetime of 40–98 ms. The applications of these COC-based composites for imaging, information encryption, and anti-counterfeiting are thus explored.

The concept of flexibility is extended to titanium frameworks and use it to gain control over charge transport. MUV-35 is a flexible doubly interpenetrated framework that can shrink spontaneously its volume by ≈40% to afford a photoconductive, porous state that is thermodynamically favored by non-covalent interactions.

Abstract

The soft nature of Metal-Organic Frameworks (MOFs) sets them apart from other non-synthetic porous materials. Their flexibility allows the framework components to rearrange in response to environmental changes, leading to different states and properties. The work extends this concept to titanium frameworks, demonstrating control over charge transport in porous molecular crystals. MUV-35 is a two-fold catenated framework composed of heterometallic TiMn2 trimers and electron donor 4,4′,4″-(benzo[1,2-b:3,4-b’:5,6-b″]trithiophene-2,5,8-triyl)tribenzoic acid (H3BTTTB) linkers, forming a rare sit-c net topology that can fold to reduce its volume by ≈40% through a single-crystal transformation controlled by linker conformation in open, intermediate, and closed states. This process, driven by a free energy difference of ≈300 kJ mol−1, originates from the formation of a continuous network of non-covalent interactions that force the spontaneous loss of the solvent in the pores of the framework to establish charge transport pathways that afford photocurrents of 2.5 × 10−3 S m−1 under visible light for an ON/OFF ratio (∆R) of four orders of magnitude. This photoconductivity rivals the best conductivity values described for though-transport conductive MOFs while maintaining a porosity of ≈1.000 m2 g−1.

Dip coating is employed to fabricate large-area organic solar cells. By controlling the fluid characteristics, the correlation among Van der Waals forces in precursor film, aggregation state of polymer, and fibrous orientation in active layer is revealed. Consequently, the dip-coated 1.0 cm2 rigid and 10.0 cm2 flexible cells exhibit the efficiencies of 17.9% and 13.7%, respectively.

Abstract

As a classical low-cost technique, dip coating has not been used for printable electronics. Here, the study demonstrates large-area organic solar cells can be made by dip coating. The correlation is revealed among Van der Waals forces in precursor film, aggregation state of polymer, and fibrous orientation in active layer; the relationship is also expounded between fluid mechanics of the confined liquid in polymer scaffold and the continuity of the acceptor phase. By controlling the fluid characteristics, the ideal nanoscale bicontinuous interpenetrating network forms. As a result, the 1.0 cm2 rigid and 10.0 cm2 flexible cells exhibit efficiencies of 17.9% and 13.7%, respectively. Moreover, the method for predicting the optimal coating speed for the dip coating of given inks is proposed. Overall, this work not only demonstrates the superiority of dip coating for organic solar cell fabrication but also provides guidance for its application in printable electronics.

Nature Materials, Published online: 27 January 2025; doi:10.1038/s41563-025-02152-7

Publisher Correction: Revitalizing interphase in all-solid-state Li metal batteries by electrophile reduction

Nature Materials, Published online: 27 January 2025; doi:10.1038/s41563-024-02101-w

Metastable spin order in a canted antiferromagnet is manipulated using strong picosecond magnetic fields, without parasitic heating.

Nature Materials, Published online: 27 January 2025; doi:10.1038/s41563-024-02085-7

A laser-free ultrafast Lorentz electron microscope has been developed, integrating a microwave-based electron pulser to achieve high spatiotemporal imaging of spin-wave dynamics in a topologically textured thin-film permalloy.

Nature Materials, Published online: 27 January 2025; doi:10.1038/s41563-024-02088-4

Material implementation of machine learning algorithms for advanced computing at cryogenic temperature remains rare. Here, the authors report a cryogenic in-memory computing platform using chiral edge states of magnetic topological insulators.

Title to be confirmed

Abstract not available

• Speaker: Sergio Blanes (Universidad Politécnica de Valencia)
• Thursday 05 June 2025, 15:00-16:00
• Venue: Centre for Mathematical Sciences, MR14.
• Series: Applied and Computational Analysis; organiser: Georg Maierhofer.

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Title to be confirmed

Abstract not available

• Speaker: Cecilie Glittum (Freie Universität Berlin)
• Thursday 27 March 2025, 14:00-15:30
• Venue: TCM Seminar Room.
• Series: Theory of Condensed Matter; organiser: Bo Peng.

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Debiased regression adjustment in completely randomized experiments with moderately high-dimensional covariates

Completely randomized experiment is the gold standard for causal inference. When the covariate information for each experimental candidate is available, one typical way is to include them in covariate adjustments for more accurate treatment effect estimation. In this paper, we investigate this problem under the randomization-based framework, i.e., that the covariates and potential outcomes of all experimental candidates are assumed as deterministic quantities and the randomness comes solely from the treatment assignment mechanism. Under this framework, to achieve asymptotically valid inference, existing estimators usually require either (i) that the dimension of covariates p grows at a rate no faster than O(n3/4) as sample size n→∞; or (ii) certain sparsity constraints on the linear representations of potential outcomes constructed via possibly high-dimensional covariates. In this paper, we consider the moderately high-dimensional regime where p is allowed to be in the same order of magnitude as n. We develop a novel debiased estimator with a corresponding inference procedure and establish its asymptotic normality under mild assumptions. Our estimator is model-free and does not require any sparsity constraint on potential outcome’s linear representations. We also discuss its asymptotic efficiency improvements over the unadjusted treatment effect estimator under different dimensionality constraints. Numerical analysis confirms that compared to other regression adjustment based treatment effect estimators, our debiased estimator performs well in moderately high dimensions.

• Speaker: Yuhao Wang (Tsinghua University)
• Tuesday 28 January 2025, 13:00-14:00
• Venue: MR14, Centre for Mathematical Sciences, Wilberforce Road, Cambridge.
• Series: Causal Inference Reading Group; organiser: Qingyuan Zhao.

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Identification and Estimation of Graphical Continuous Lyapunov Models

Graphical continuous Lyapunov models offer a new perspective on modeling causally interpretable dependence structure in multivariate data by treating each independent observation as a one-time cross-sectional snapshot of a temporal process. Specifically, the models consider multivariate Ornstein-Uhlenbeck processes in equilibrium. This leads to Gaussian models in which the covariance matrix is determined by the continuous Lyapunov equation. In this setting, each graphical model assumes a sparse drift matrix with support defined by a directed graph. The talk will discuss the identifiability of such sparse drift matrices and their regularized estimation.

Note unusual location

• Speaker: Mathias Drton (Technical University of Munich)
• Friday 07 February 2025, 14:00-15:00
• Venue: Centre for Mathematical Sciences MR15, CMS.
• Series: Statistics; organiser: Qingyuan Zhao.

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Natural Materials for Musical Instruments

Immediately following the CNHS AGM , Jim Woodhouse will give a Presidential Address on the various uses of natural materials in the making of traditional musical instruments.

The talk will focus mostly on wood: why instrument makers prefer certain particular types of wood, what it is in the cellular structure that makes these timbers special, and what scope there may be to use alternative materials in the light of climate pressure and CITES restrictions.

Please note the start time, being after the AGM, is approximate.

• Speaker: Jim Woodhouse, CNHS President; Emeritus Professor of Structural Dynamics
• Thursday 20 March 2025, 19:00-20:30
• Venue: Main Seminar Room (First Floor) David Attenborough Building, University of Cambridge Pembroke St, Cambridge CB2 3QZ.
• Series: Cambridge Natural History Society; organiser: president.

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The Cambridgeshire Bird Club - 1925 to 2025: a century of bird watching

The people, the places and the birds, losers and winners – a century of the most remarkable changes.

• Speaker: Bob Jarman
• Thursday 13 March 2025, 18:45-20:00
• Venue: Main Seminar Room (First Floor) David Attenborough Building, University of Cambridge Pembroke St, Cambridge CB2 3QZ.
• Series: Cambridge Natural History Society; organiser: events.

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CNHS Field Studies 2024

This talk will summarise the various CNHS fieldwork projects during 2024.

Jonathan will talk about plants and fungi, Duncan about moth-trapping.

• Speaker: Duncan Mackay and Jonathan Shanklin
• Thursday 27 February 2025, 18:45-20:00
• Venue: Main Seminar Room (First Floor) David Attenborough Building, University of Cambridge Pembroke St, Cambridge CB2 3QZ.
• Series: Cambridge Natural History Society; organiser: events.

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Great Fen: progress on the peat

Find out the latest from the Great Fen.

With so much going on at the Fen since the purchase of Speechly’s Farm, it’s never too soon for an update.

With the usual sights and sounds from the Great Fen, including trail camera and drone videos.

• Speaker: Henry Stanier, Monitoring & Research Officer at the BCN Wildlife Trust
• Thursday 20 February 2025, 18:45-20:00
• Venue: Main Seminar Room (First Floor) David Attenborough Building, University of Cambridge Pembroke St, Cambridge CB2 3QZ.
• Series: Cambridge Natural History Society; organiser: events.

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