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A Bayesian Neural Network approach to study dissolved oxygen in Southern Ocean water masses

Oxygen plays a critical role in the health of marine ecosystems. As oceanic O2 concentration decreases to hypoxic levels, marine organisms’ habitability decreases rapidly. However, identifying the physical patterns driving this reduction in dissolved oxygen remains challenging. This study employs a Bayesian Neural Network (BNN) to analyze the uncertainty in dissolved oxygen forecasts. The method’s significance lies in its ability to assess oxygen forecasts’ uncertainty with evolving physical dynamics. The BNN model outperforms traditional linear regression and persistence methods, particularly under changing climate conditions. Our approach leverages three Explainable AI (XAI) techniques—Integrated Gradients, Gradient SHAP , and DeepLIFT—to provide meaningful interpretations of 2- and 8-year forecasts. The XAI analysis reveals that buoyancy frequency and eddy kinetic energy is a critical predictor for short-term forecasts across the North Atlantic Deep Water (NADW), Upper Circumpolar Deep Water (UCDW), masses. While the LCDW variability emphasizes also a role played by advection processes, such as salinity, over short and long timescales.

• Speaker: Gian Giacomo Navarra, Princeton University
• Wednesday 26 March 2025, 15:30-16:30
• Venue: BAS Seminar Room 330b.
• Series: British Antarctic Survey - Polar Oceans seminar series; organiser: birgal.

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Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D5EE00494B, Review ArticleLiyu Zhu, Yu Cao, Ting Xu, Hongbin Yang, Luying Wang, Lin Dai, Fusheng Pan, Chaoji Chen, Chuanling Si
Covalent organic frameworks (COFs) are a class of porous crystalline materials based on reticular and dynamic covalent chemistry. Flexible molecular design strategies, tunable porosity, modifiable frameworks, and atomically precise structures...
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Title to be confirmed

Abstract to be confirmed

Link to join virtually: https://cam-ac-uk.zoom.us/j/87421957265

This talk is being recorded. If you do not wish to be seen in the recording, please avoid sitting in the front three rows of seats in the lecture theatre. Any questions asked will also be included in the recording. The recording will be made available on the Department’s webpage

• Speaker: Speaker to be confirmed
• Wednesday 28 May 2025, 15:05-15:55
• Venue: Lecture Theatre 1, Computer Laboratory, William Gates Building.
• Series: Wednesday Seminars - Department of Computer Science and Technology ; organiser: Ben Karniely.

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Title to be confirmed

Abstract to be confirmed

Link to join virtually: https://cam-ac-uk.zoom.us/j/87421957265

This talk is being recorded. If you do not wish to be seen in the recording, please avoid sitting in the front three rows of seats in the lecture theatre. Any questions asked will also be included in the recording. The recording will be made available on the Department’s webpage

• Speaker: Professor Gabriele Gradoni - Institute for Communication Systems, University of Surrey and visiting academic at the Department of Computer Science and Technology, University of Cambridge
• Wednesday 04 June 2025, 15:05-15:55
• Venue: Lecture Theatre 1, Computer Laboratory, William Gates Building.
• Series: Wednesday Seminars - Department of Computer Science and Technology ; organiser: Ben Karniely.

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Title to be confirmed

Abstract to be confirmed

Link to join virtually: https://cam-ac-uk.zoom.us/j/87421957265

This talk is being recorded. If you do not wish to be seen in the recording, please avoid sitting in the front three rows of seats in the lecture theatre. Any questions asked will also be included in the recording. The recording will be made available on the Department’s webpage

• Speaker: Dr Elliott Wu - Department of Engineering, University of Cambridge
• Wednesday 21 May 2025, 15:05-15:55
• Venue: Lecture Theatre 1, Computer Laboratory, William Gates Building.
• Series: Wednesday Seminars - Department of Computer Science and Technology ; organiser: Ben Karniely.

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Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D4EE06021K, Review ArticleNafees Ahmad, Jun Yuan, Yingping Zou
Non-fullerene acceptors-based organic solar cells (NF-OSCs) have achieved notable advancement during the past few years. Recently, the power conversion efficiency (PCE) has surpassed 20 % due to the development of...
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Walter Kohn: the theoretical physicist who created DFT and won the Nobel Prize for Chemistry

Density Functional Theory (DFT) has become one of the most highly cited techniques in science, widely used for simulations in physics, chemistry, materials science and biology. The modern form of DFT was invented by Walter Kohn after a remarkable personal journey which included escaping on the Kindertransport to England on almost the last train out of Vienna in August 1939, and then being interned in Canada deep in a forest miles from civilisation. Despite these disadvantages, Walter Kohn was able to have an exceptional academic career in theoretical solid state physics which culminated in DFT and the Nobel Prize (but for Chemistry, not Physics). Drawing on fresh insights from his recent biography Walter Kohn: From Kindertransport and Internment to DFT and the Nobel Prize , David Clary will describe the remarkable life, career and science of Walter Kohn.

• Speaker: Prof. Sir David Clary, FRS (University of Oxford)
• Thursday 22 May 2025, 14:00-15:30
• Venue: TCM Seminar Room.
• Series: Theory of Condensed Matter; organiser: Bo Peng.

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Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D5EE00144G, Review ArticleJizhong Zhao, Xiaoxuan Fan, Hongxiang Xie, Yi Luo, Zhifeng Li, Xiao Peng, Guangming Tao, Zhong Lin Wang, Kai Dong
Mechano-electric conversion fibers (MECFs) represent a groundbreaking innovation in smart textiles, integrating the high-efficiency mechanical energy conversion of triboelectric nanogenerators (TENGs) with superior wearability and comfort inherent in textile materials....
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This study explores the synergistic interplay between oxygen reduction reaction and NH4 + storage, and harnesses the synergy for the successful development of a high-rate and highly stable ammonium ion air battery (AIAB). The assembled AIAB demonstrates outstanding rate performance (89 mAh g−1 at 15 A g−1), high energy density (78 Wh kg−1 at 9369 W kg−1), and exceptional cycling stability at 10 A g−1.

Abstract

Ammonium ion batteries (AIBs) offer cost-effectiveness, nontoxicity, and eco-friendly attributes in energy storage technology. However, the constrained capacity and poor stability of conventional cathode materials have impeded their widespread adoption. Herein, a synergistic approach is introduced to overcome these challenges, by enhancing the air cathode with NH4 + and simultaneously leveraging atmospheric oxygen as a reservoir for NH4 + storage. Notably, NH4 + significantly enhances the oxygen reduction reaction (ORR) performance in neutral environments. Through in situ Raman spectroscopy and quantum density functional theory calculations, it is elucidated how NH4 + can act as a proton donor, replacing H2O in neutral media and reducing energy barriers in the protonation of *O2 − and *O, thereby accelerating ORR kinetics. The resulting ammonium ion-air battery, comprising an air cathode and a polymer (PNP) anode, showcases impressive metrics: high energy density of 78 Wh kg−1 and power density of 9369 W kg−1 at 1 A g−1, an initial capacity of 94.3 mAh g−1 and exceptional cycling stability (70.4% capacity retention after 12 500 cycles) at 10 A g−1. This pioneering research highlights the synergistic relationship between ORR and NH4 + storage and opens up new avenues for the design and advancement of innovative, sustainable, and environment-friendly AIBs.

A novel ionizing radiation-responsive delivery system is designed for the precise expression of anti-TREM2 single-chain antibody fragments (scFv) using an engineered probiotic, Escherichia coli Nissle 1917 (EcN), to modulate immunotherapy.

Abstract

Preoperative neoadjuvant radio-chemotherapy is a cornerstone in the treatment of low rectal cancer, yet its effectiveness can be limited by the insensitivity of some patients, profoundly impacting their quality of life. Through preliminary research, it is found that TREM2+ macrophages play a pivotal role in the non-responsiveness to immunotherapy. To address this challenge, a novel ionizing radiation-responsive delivery system is developed for the precise expression of anti-TREM2 single-chain antibody fragments (scFv) using an engineered probiotic, Escherichia coli Nissle 1917 (EcN), to modulate immunotherapy. The released anti-TREM2 scFv can be precisely targeted and delivered to the tumor site via the engineered EcN outer membrane vesicles (OMVs), thereby reversing the immunosuppressive tumor microenvironment and enhancing tumor therapeutic efficiency when used in combination with the αPD-L1 immune checkpoint inhibitor. Additionally, these engineered bacteria can be further modified to enhance the intestinal colonization capabilities through oral administration, thereby regulating the gut microbiota and its metabolic byproducts. Consequently, the ionizing radiation-responsive drug delivery system based on the engineered bacteria not only introduces a promising new therapeutic option for low rectal cancer but also showcases the potential to finely tune immune responses within the intricate tumor microenvironment, paving the way for innovative strategies in tumor radio-immunotherapy.

In situ repair and surface reconstruction of oxidized copper (Cu) (Cu foil, Cu nanowires, Cu nanoparticles) is achieved by solvothermal reaction. The experimental data and Density functional theory calculations demonstrate that (111) crystal-plane reconstruction enhances the oxidation resistance of the metal, and the method is equally applicable to the Ag nanomaterials (Ag nanowires, Ag nanocubes), which also exhibits good oxidation resistance.

Abstract

The in situ repair of oxidized copper (Cu) surfaces while constructing a superior protective layer is critical for sustainable development and the efficient utilization of metallic materials. Here, a simple solvothermal treatment is presented to repair oxidized Cu surfaces (Cu foils, nanowires, and nanocubes) and reconstruct an antioxidant layer with an ordered (111) crystal-plane (Cu-SC) in situ. Electrochemical measurements reveal that the corrosion rate of Cu-SC in 0.1 m NaOH is reduced to 1.99 × 10−3 mm yr−¹, a fivefold improvement over pristine Cu (1.00 × 10− 2 mm yr−¹). Density functional theory calculations confirm that the reconstructed (111) surface reduces oxygen molecule adsorption, significantly hinders oxygen atom diffusion into the bulk and continuous adsorption on surface. Anti-counterfeiting labels fabricated from Cu-SC nanowires exhibit exceptional durability, retaining reliable authentication accuracy after 144 h at 85 °C/85% relative humidity and 2000 bending cycles. The enhanced anti-oxidation properties of Cu-SC ensure the stability of its microstructures, which are critical for deep learning-based authentication, allowing precise feature extraction and accurate label verification even under extreme conditions. These results highlight the potential of (111) surface reconstruction for enhancing material stability, enabling advanced anti-counterfeiting applications, and promoting the sustainable utilization of metallic materials.

A cost-effective ternary Prussian blue analog is synthesized via structural regulation to achieve the compatibility of high capacity and long lifespan for sodium-ion batteries within a wide temperature range. Mn and Cu synergistically enhances conductivity, operating voltage, and stability, suppressing Jahn–Teller distortions. This design enables high-loading 18650-type cells with exceptional electrochemical performance, supporting grid-scale energy storage.

Abstract

High-performance, cost-effective cathodes are essential for grid-scale sodium-ion batteries (SIBs). Prussian blue analogs (PBAs) have shown great potential as SIB cathodes, but achieving both high capacity and long lifespan remains challenging. In this study, a series of low-cost ternary PBAs synthesized through structural regulation is presented to simultaneously achieve high capacity, stable cycling performance, and broad temperature adaptability. Among them, CuHCF-3 demonstrates a specific capacity of 132.4 mAh g−1 with 73.3% capacity retention over 1000 cycles. In-depth analyses, using in situ techniques and density functional theory calculations, reveal a highly reversible three-phase transition (monoclinic ↔ cubic ↔ tetragonal) in Na1.96Cu0.45Mn0.55[Fe(CN)6]0.91·□0.09·2.14H2O (CuHCF-3), which is driven by synergistic interactions between Mn and Cu. Mn enhances conductivity, increases the operating voltage, and introduces additional redox centers, while Cu mitigates the Jahn–Teller distortions associated with Mn and buffers volume changes during cycling. This structural synergy results in excellent temperature stability across a wide temperature range (−20 to 55 °C). 18650-type cylindrical cells based on CuHCF-3 with high loading density achieve 73.54% capacity retention over 850 cycles. This study offers valuable insights for designing durable, high-capacity electrode materials for SIB energy storage applications.

The peptide-oligonucleotide (PON) nanohybrids can be readily fabricated by the bioorthogonal click reaction between PEG5-P7-R9-(G-DOPA)4-HPGGPQ-H8-C-DBCO and miRNA-124-A5-(CH2)6-Azido, which achieve targeted delivery to the lesion sites, robust penetration through cell membrane, efficient scavenging of intracellular ROS, as well as timely escape from the endolysosomes of macrophages, inhibiting proinflammatory M1 polarization and osteoclast differentiation, eventually attenuating arthritic bone destruction and systemic osteoporosis.

Abstract

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by excessive inflammation, pathological bone resorption, and systemic osteoporosis. It lacks effective treatment due to the complex pathogenesis. Gene therapy, especially targeted oligonucleotide (ON) delivery therapy, offers a new prospect for the precise treatment of RA. Nevertheless, the clinical application of ON delivery therapy still faces various challenges such as the rapid enzymolysis by RNAse, the lack of tissue targeting ability, difficulty in cell membrane penetration, and the incapability of endolysosomal escape. To address these issues, a novel kind of engineered peptide and oligonucleotide (PON) nanohybrids are designed and fabricated, which provide various advantages including good biosafety, inflammatory region-targeted delivery, cell membrane penetration, reactive oxygen species (ROS) scavenging, and endolysosomal escape. The PON nanohybrids produce promising effects in suppressing inflammatory responses and osteoclastogenesis of macrophages via multiple signaling pathways. In vivo administration of PON nanohybrids not only ameliorates local joint bone destruction and systemic osteoporosis in the pathological state, but also demonstrates good prophylactic effects against the rapid progression of RA disease. In conclusion, the study presents a promising strategy for precise RA treatment and broadens the biomedical applications of gene therapy based on delivery system.

A sandwich-like device for stick-slip perception is developed, featuring a deformable bioinspired ridge layer with capability of lateral deformation and fast recovery. Coupled with magnetized functionality, the morphological transformation is capable to induce periodical electrical pulses which allows to revisit the stick-slip process when human fingertip scans across a specific surface.

Abstract

“Stick-slip” phenomenon that occurs when human fingertip scans across a specific surface is essential to perceive the interactions between skin and the surface. Understanding the “stick-slip” behavior is important for bionic flexible system in applications from advanced robotics to intelligent tactile sensors. However, it is often overlooked owing to the limitations to mimic the soft skin that can tangentially deform/recover with informative electrical feedback. Here, a sandwich-type device with deformable ridge-layer is proposed to analyze the characteristic of stick/slip states in “stick-slip” process. Specifically, it is observed that fast recovery of the sensing architecture is caused by dynamic slip phase that generates periodical signals based on principle of induction. The results experimentally show that periods of the electrical pulses are dependent on factors such as inherent properties (e.g., modulus and geometry) and operational parameters (e.g., scanning speed and normal load), which is consistent with the theoretical model. Furthermore, it is found that the transition between “stick-slip” and full slip could qualitatively reflect interfacial properties such as moisture, roughness, and topology. It is expected that the results can strengthen the understanding of “stick-slip” behavior when fingertip interacts with a surface and provide guidance of flexible sensor design to enrich the biomimetic perceptions.

DNA-directed assembly offers a powerful strategy for constructing structured photonic nanomaterials with precise spatial control. This review provides a comprehensive overview of recent advancements in DNA-assembled photonic nanomaterials for diagnostics and therapeutics, highlighting key design principles, functionalization strategies, and optical effects that enhance their performance in biomedical applications.

Abstract

DNA-directed assembly has emerged as a versatile and powerful approach for constructing complex structured materials. By leveraging the programmability of DNA nanotechnology, highly organized photonic systems can be developed to optimize light-matter interactions for improved diagnostics and therapeutic outcomes. These systems enable precise spatial arrangement of photonic components, minimizing material usage, and simplifying fabrication processes. DNA nanostructures, such as DNA origami, provide a robust platform for building multifunctional photonic devices with tailored optical properties. This review highlights recent progress in DNA-directed assembly of photonic nanomaterials, focusing on their applications in diagnostics and therapeutics. It provides an overview of the latest advancements in the field, discussing the principles of DNA-directed assembly, strategies for functionalizing photonic building blocks, innovations in assembly design, and the resulting optical effects that drive these developments. The review also explores how these photonic architectures contribute to diagnostic and therapeutic applications, emphasizing their potential to create efficient and effective photonic systems tailored to specific healthcare needs.

The air-operated assembly of aqueous Fe-ion batteries is realized by a very unexpected finding when excess acid is introduced into the traditional aqueous FeSO4 electrolyte. A proton/O2 competitive mechanism for the as-detected ultra-low dissolved O2 and reduced coordinated O2 in the Fe2+ solvated shell is revealed.

Abstract

Fe2+ have emerged as the ideal charge carriers to construct aqueous batteries as one of the most competitive candidates for next-generation low-cost and safe energy storage. Unfortunately, the fast oxidation of Fe2+ into Fe3+ at ambient conditions inevitably requires the assembly process of the cells in an oxygen-free glovebox. Up to date, direct air assembly of aqueous Fe-ion battery remains very desirable yet highly challenge. Here oxidation of Fe2+ is found at ambient condition and is completely inhibited in an acidic electrolyte. A proton/O2 competitive mechanism in the acidic electrolyte is revealed with reduced coordinated O2 in the Fe2+ solvated shell for this unexpected finding. Based on this surprise, for the first time, air-operated assembly of iron-ion batteries is realized. Meanwhile, it is found that the acidic environment induces the in situ growth of active α-FeOOH derivate on the VOPO4·2H2O surface. Strikingly, the acidic electrolyte enables an air-operated Fe-ion battery with a high specific capacity of 192 mAh g−1 and ultrastable cycling stability over 1300 cycles at 0.1 A g−1. This work makes a break through on the air-assembly of Fe-ion battery without oxygen-free glovebox. It also reveals previously unknown proton/O2 competitive mechanisms in the Fe2+ solvated shell and cathode surface chemistry for aqueous Fe2+ storage.

Centimeter-scale arrays of single nanoparticles, generated through either Dip Pen Nanolithography or Polymer Pen Lithography, allow for the discovery of novel nanomaterials at an unprecedented scale. The development of phase-separating hydrophobic nanoreactors bypasses element-specific chemistry limitations, enabling the synthesis of polyelemental metal and metal oxide nanoparticle megalibraries from at least 52 metal elements with an almost infinite number of chemical combinations in a single experiment.

Abstract

Phase-separating nanoreactors, generated through either Dip Pen Nanolithography (DPN) or Polymer Pen Lithography (PPL) and capable of single nanoparticle formation, are compatible with almost every relevant element from the periodic table. This advance overcomes one of the most daunting limitations in high throughput materials discovery, specifically enabling the synthesis of broad swaths of the materials genome. Indeed, the platform is compatible with at least 52 metal elements of interest and almost an infinite number of combinations. In particular, it is discovered that surface-confined, attoliter-volume reactors made of polystyrene (PS) mixtures can be preloaded with metal salts spanning all but the alkali metals and subsequently transformed into single- or multi-component nanoparticles of well-defined dimensions. This is done in a three-step process, which initially involves the facilitation of precursor precipitation and localization with toluene vapor, followed by plasma treatment to remove the polymer reactor component, and then heating from 400–900 °C, depending upon precursor and desired end-state (degree of reduction and crystallinity). These phase-separating nanoreactors are used to produce metal and metal oxide nanoparticles, depending upon conditions, in a substrate-general manner.

Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D5EE00073D, PaperWenwu Zhou, Yunhe Cai, Shuo Wan, Yi Li, Xiaoying Xiong, Fangchong Zhang, Huiting Fu, Qingdong Zheng
The surface post-treatment of perovskite films is regarded as one of the most effective methods for enhancing the performance of perovskite solar cells (PSCs) and is essential for achieving high-efficiency...
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Asymmetry in Supposedly Equivalent Facts: Pre-training Bias in Large Language Models

Understanding and mitigating hallucinations in Large Language Models (LLMs) is crucial for ensuring reliable content generation. While previous research has primarily focused on “when” LLMs hallucinate, our work explains “why” and directly links model behaviour to the pre-training data that forms their prior knowledge. Specifically, we demonstrate that an asymmetry exists in the recognition of logically equivalent facts, which can be attributed to frequency discrepancies of entities appearing as subjects versus objects. Given that most pre-training datasets are inaccessible, we leverage the fully open-source OLMo series by indexing its Dolma dataset to estimate entity frequencies. Using relational facts (represented as triples) from Wikidata5M, we construct probing datasets to isolate this effect. Our experiments reveal that facts with a high-frequency subject and a low-frequency object are better recognised than their inverse, despite their logical equivalence. The pattern reverses in low-to-high frequency settings, and no statistically significant asymmetry emerges when both entities are high-frequency. These findings underscore the influential role of pre-training data in shaping model predictions and provide insights for inferring the characteristics of pre-training data in closed or partially closed LLMs.

• Speaker: Zifeng Ding (University of Cambridge)
• Friday 09 May 2025, 12:00-13:00
• Venue: Room SS03 with Hybrid Format. Here is the Zoom link for those that wish to join online: https://cam-ac-uk.zoom.us/j/4751389294?pwd=Z2ZOSDk0eG1wZldVWG1GVVhrTzFIZz09.
• Series: NLIP Seminar Series; organiser: Suchir Salhan.

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Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D5EE00542F, PaperPengfei Ding, Xugang Rong, Daobin Yang, Xueliang Yu, Zhenxin Shao, Hongqian Wang, Xiaochun Liao, Xinyue Cao, Jie Wu, Lin Xie, Jintao Zhu, Fei Chen, Guo Chen, Yan Huang, Ziyi Ge
The majority of host/guest materials used in organic solar cells (OSCs) are currently synthesized via Stille reaction, which suffers from poor atom/step economics, low cost-effectiveness, and environmental risks. Therefore, organic...
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