Feed aggregator

The CeO2- x -suspension electrolyte is initially proposed to regulate the Zn[(H2O)6]2+ solvation structure and alters the inner Helmholtz plane to accelerate Zn[(H2O)6]2+ desolvation, achieving a homogenized electric field and uniform ion flux kinetics. Consequently, the suspen sion electrolyte achieves a service life exceeding 6500 h at 0 °C and demonstrates outstanding rate performance at −20 °C, highlighting its practical potential for AZMBs.

Abstract

The conventional electrolyte for rechargeable aqueous zinc metal batteries (AZMBs) breeds many problems such as Zn dendrite growth and side reaction of hydrogen evolution reaction, which are fundamentally attributed to the uneven ion flux owing to the high barriers of desolvation and diffusion of Zn[(H2O)6]2+ clusters. Herein, to modulate the [Zn(H2O)6]2+ solvation structure, the suspension electrolyte engineering employed with electron-delocalized catalytic nanoparticles is initially proposed to expedite desolvation kinetics. As a proof, the electron-density-adjustable CeO2- x is introduced into the commercial electrolyte and preferentially adsorbed on the Zn surface, regulating the Zn[(H2O)6]2+ structure. Meanwhile, the defect-rich CeO2- x redistributes the localized space electric field to uniformize ion flux kinetics and inhibits dendrite growth, as confirmed by a series of theoretical simulations, spectroscopical and experimental measurements. Encouragingly, the CeO2- x decorated suspension electrolyte enables a long stability over 1200 cycles at 5 mA cm−2 and an extended lifespan exceeding 6500 h with lower overpotentials of 34 mV under 0 °C. Matched with polyaniline cathodes, the full cells with suspension electrolyte exhibit a capacity-retention of 96.75% at 1 A g−1 under −20 °C as well as a long lifespan of up to 400 cycles in a large-areal pouch cell, showcasing promising potentials of suspension electrolyte for practical AZMBs.

An eye-drop nano-formulation of catalase self-assembled with cysteine-modified chitosan is designed. The obtained nanoparticles after eye-drop administration could form disulfide bonds with the mucin layer of the team film to achieve enhanced precorneal adhesion, so as to continuously eliminate excessive reactive oxygen species accumulated in the ocular surface to suppress inflammation, resulting in effective treatment of dry eye disease.

Abstract

Dry eye disease (DED), the most prevalent ophthalmological condition worldwide, can cause severe ocular discomfort and even visual impairment. Effective yet safe therapeutics for severe DED are still highly demanded. Herein, considering the important role of excessive reactive oxygen species (ROS) in triggering DED, an eye-drop nano-formulation of catalase (CAT) self-assembled with cysteine-modified chitosan (CS-Cys) is designed for DED treatment. Upon eye-drop administration of CS-Cys/CAT nanoparticles, CS-Cys can form disulfide bonds with abundant thiols in the mucin layer of the tear film, anchoring catalase to the corneal surface. Thus the excess ROS accumulated on the ocular surface can be effectively eliminated, resulting in a regulated tear microenvironment. In mouse and rabbit models, it is verified that CS-Cys/CAT eye drops can offer excellent therapeutic effects, especially in promoting the recovery of damaged epithelium and increasing tear secretion. Remarkably, CS-Cys/CAT eye drops showed notably better therapeutic performance than clinically used cyclosporin and dexamethasone, as well as several new DED drugs in clinical trials. Thus, the work presents a unique nanoparticulate eye-drop-based ocular delivery system to allow prolonged ocular retention of protein therapeutics, and such nanoformulation formulated by fully biocompatible/biodegradable components possesses significant translational potential for effective and safe DED treatment.

Increasing InAs CQD size exposes diverse facets and edges, bringing challenges for effective passivation. This work introduces a mixed-halide passivation strategy to stabilize these facets and edges, doubling anti-oxidation ability and boosting mobility. The resulting photodetectors achieve 75% EQE, 10 ns response time, and 50 h operational stability (10% loss) at 1140 nm, advancing InAs CQD photodetector performance.

Abstract

Lead-free III-V colloidal quantum dots (CQDs) are of significant interest for their potential in near-infrared (NIR) to short-wave infrared (SWIR) photodetection. However, achieving effective surface passivation remains challenging, especially as larger CQD sizes introduce more complex surface facets and compositions while shifting the absorption peak from the NIR to the SWIR range. In this study, a mixed-halide passivation strategy is developed for large InAs CQDs, an approach that led to a doubling in anti-oxidation ability and achieves a hole mobility of 0.03 cm2 Vs−1. These in turn led to a T90 lifetime of 50 h and enhanced operating stability in photodetectors operating at 1140 nm. Density functional theory (DFT) simulations and facet characterization indicate that exposed facets and edges are well passivated using a mixture of indium halides, which provide a stronger desorption energy compared to single-halide passivation. This approach yields photodetectors with an external quantum efficiency (EQE) of 75% and a response time of 10 ns, an advance for InAs photodetectors operating at 1140 nm.

A strategy that integrates the Ir/Mn co-mixing and the strong oxide-support interaction modulation through plasma defect engineering is used for the development of the catalysts that follow the oxide path mechanism for the oxygen-evolution reaction (OER). The obtained catalyst shows exceptional OER activity and remarkable stability in the acid media.

Abstract

Developing efficient and stable catalysts that facilitate the oxygen-evolution reaction (OER) through an oxide-path mechanism (OPM) is of considerable interest. However, it remains a significant challenge due to the stringent structural requirements of these catalysts. This work reports that using a strategy that integrates the Ir/Mn co-mixing and the strong oxide-support interaction (SOSI) modulation, efficient and stable Ir-based catalysts that follow the OPM for the acidic OER can be developed. The strategy mainly relies on optimizing the distance of oxygeneous intermediate adsorption sites by the Ir/Mn co-mixing and modulating the SOSI of the catalysts through plasma defect engineering to trigger the OPM pathway with a lower energy barrier. The density-functional-theory (DFT) calculations reveal a strong electronic coupling between Ir and Mn via the Ir─O─Mn bond and a ready coupling of oxygeneous adsorbed on the Ir site with those on the Mn site, leading to an asymmetric oxygen coupling for the OER. The developed catalyst merely requires an overpotential of 240 mV to drive 10 mA cm−2 with the Ir mass-activity > 75 times higher than that of the IrO2. When used in the proton-exchange-membrane water-electrolyzers, it shows high performance and excellent stability at an industrial-level current density of 1.0 A cm−2.

Fractional Charge and Fractional Statistics & how they are connected

After a review of the history of the subject, I will discuss the claim that fractional charge by itself implies fractional statistics, and show that there is a loophole in the original argument for why this is the case. I will then provide an improved argument that also assumes that the system is in a fractional quantum Hall state. First I give a heuristic version of the argument and then a formal one. I also point out the failure of the original argument is connected to a 1-form t´Hooft anomaly in a Chern-Simons theory.

• Speaker: Prof. Thors Hans Hansson (Stockholm)
• Wednesday 26 March 2025, 16:00-17:30
• Venue: TCM Seminar Room.
• Series: Theory of Condensed Matter; organiser: Bo Peng.

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Nature Materials, Published online: 24 March 2025; doi:10.1038/s41563-025-02184-z

Lipid nanoparticles formulated with ionizable lipids inspired by brain-targeting small molecules facilitate the delivery of mRNA past the blood–brain barrier and into the brain.

Nature Materials, Published online: 24 March 2025; doi:10.1038/s41563-025-02162-5

Extracellular anisotropic stresses trigger fibroblast transition into myofibroblasts by the mechanical self-reinforcement of cell–extracellular matrix interactions.

Nature Materials, Published online: 24 March 2025; doi:10.1038/s41563-025-02170-5

The authors review the mechanisms of resistive switching in monolayer and bulk forms of two-dimensional layered materials, providing insights into atomic motions and electronic transport across interfaces.

Nature Materials, Published online: 24 March 2025; doi:10.1038/s41563-025-02180-3

Exploiting the intrinsic response of magic-angle twisted bilayer graphene to resonant terahertz radiation, the interplay between electron interactions and quantum geometry is studied in such flat-band systems.

Nature Materials, Published online: 24 March 2025; doi:10.1038/s41563-025-02185-y

A superlattice structure of gold tetrahedra formed via a surface-promoted pathway is reported. The octo-diamond crystal is achiral, but exhibits bilayers of left- and right-handed chiral motifs with chiroptical plasmonic responses.

Nature Nanotechnology, Published online: 24 March 2025; doi:10.1038/s41565-025-01895-3

A graphene-nanopocket-protected pure Pt nanocatalyst has been reported for heavy-duty-vehicle fuel cells that deliver high power density, high efficiency and exceptional durability with >200,000-h projected lifetime.

Nature Nanotechnology, Published online: 24 March 2025; doi:10.1038/s41565-025-01893-5

Carbon–hydrogen and carbon–deuterium bonding in organic polymers were mapped in real space with single-nanometre spatial resolution using a monochromated transmission electron microscope.

Title to be confirmed

Abstract not available

• Speaker: Jujian Zhang (Imperial College London) and Arnaud Mayeux (The Hebrew University of Jerusalem)
• Thursday 19 June 2025, 17:00-18:00
• Venue: MR14 Centre for Mathematical Sciences.
• Series: Formalisation of mathematics with interactive theorem provers ; organiser: Anand Rao Tadipatri.

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The Chow Ring of the Moduli Stack of Hyperelliptic Prym Pairs

The study of intersection theory on moduli spaces and stacks has a rich history, beginning with Mumford’s seminal 1983 paper, where he introduced the Chow ring with rational coefficients for the moduli space of smooth pointed curves of a given genus and its Deligne–Mumford compactification. This framework was later extended by Vistoli to Deligne–Mumford stacks, by Edidin and Graham to quotient stacks, and more generally by Kresch to both integral and rational coefficients. Since then, extensive research has been devoted to computing the intersection theory of various moduli stacks.

In this talk, we will focus on the integral version of Chow rings, which is generally less well understood. I will first review some known results in this direction. I will then outline the computation of the integral Chow ring of the moduli stack of hyperelliptic Prym curves, which are étale double covers of hyperelliptic curves—a result that Alessio Cela and I recently obtained. In the case of genus two, our results recover a previous computation by Cela and Lopez.

• Speaker: Alberto landi, Brown University
• Friday 28 March 2025, 14:15-15:15
• Venue: CMS MR13.
• Series: Algebraic Geometry Seminar; organiser: Dhruv Ranganathan.

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Irreducibility of Severi varieties on toric surfaces

Severi varieties parametrize integral curves of fixed geometric genus in a given linear system on a surface. In this talk, I will discuss the classical question of whether Severi varieties are irreducible and its relation to the irreducibility of other moduli spaces of curves. I will indicate how tropical methods can be used to answer such irreducibility questions. The new results are from ongoing joint work with Xiang He and Ilya Tyomkin.

• Speaker: Karl Christ, Università degli studi di Torino
• Tuesday 25 March 2025, 14:15-15:15
• Venue: CMS MR13.
• Series: Algebraic Geometry Seminar; organiser: Dhruv Ranganathan.

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Brill-Noether loci of pencils with prescribed ramification

The geometry of curves carrying pencils with prescribed ramification is regulated by the so called adjusted Brill-Noether number. In this talk I will discuss the problem of existence and dimension of Brill-Noether varieties in this context and compare it to the classical one without imposed ramification. The new results are based on joint work with Andreas Leopold Knutsen.

• Speaker: Sara Torelli, Università degli studi di Torino.
• Tuesday 25 March 2025, 10:00-11:00
• Venue: CMS MR13.
• Series: Algebraic Geometry Seminar; organiser: Dhruv Ranganathan.

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Woe is Me!: Spatial Logic and Memory in the OIMOI Inscriptions of Selinous

In the ancient Greek city-state of Selinous in Sicily, there is a unique set of funerary inscriptions which directly lament the fate of the deceased. This formula lacks precedent elsewhere in the Greek world, and I explore how the content of these inscriptions interact with the space on which they are laid out, the memorial stones themselves, and the surrounding landscape. I argue that the negative space employed in many of the inscriptions speaks just as forcefully as the text itself, and that it renders memory in terms of absence, not presence.

• Speaker: Campbell Rosener
• Tuesday 20 May 2025, 13:10-14:00
• Venue: Richard King room, Darwin College.
• Series: Darwin College Humanities and Social Sciences Seminars; organiser: Matthew Jones.

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Professor Awen Gallimore, Co-Director of Systems Immunity Research Institute, Cardiff University

This Cambridge Immunology and Medicine Seminar will take place on Thursday 27 March 2025, starting at 4:00pm, in the Ground Floor Lecture Theatre, Jeffrey Cheah Biomedical Centre (JCBC)

Speaker: Professor Awen Gallimore, Co-Director of Systems Immunity Research Institute, Cardiff University

Title: TBC

Host: Maike De La Roche & Tim Halim, CRUK Cambridge Institute

Refreshments will be available following the seminar.

• Speaker: Professor Awen Gallimore, Co-Director of Systems Immunity Research Institute, Cardiff University
• Thursday 27 March 2025, 16:00-17:00
• Venue: Lecture Theatre, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus.
• Series: Cambridge Immunology Network Seminar Series; organiser: Ruth Paton.

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Field-induced Multi-Q⃗ States in a Pyrochlore Heisenberg Magnet

In this talk, I will present a recent work on the J1-J3b classical Heisenberg model on the pyrochlore lattice in the presence of a magnetic field. We construct exact ground states of the model, which are non-coplanar multi-Q⃗ spin configurations with a large magnetic unit cell. Using linear spin wave theory, we show that entropy favours these multi-Q⃗ states at low temperatures in high magnetic fields. This is confirmed by Monte Carlo simulations, which we also use to map out a phase diagram. Lastly, we calculate the zero-temperature dynamical structure factor. Besides the usual Goldstone modes associated with the ordering Q⃗s, we find high-intensity gapless modes at momenta where there are no Bragg peaks.

• Speaker: Cecilie Glittum (Helmholtz-Zentum 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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Surgical data using LLMs

Abstract not available

• Speaker: Hugo Georgenthum
• Friday 21 March 2025, 17:00-17:45
• Venue: Lecture Theatre 2, Computer Laboratory, William Gates Building.
• Series: Foundation AI; organiser: Pietro Lio.

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