Nanoscale Visualization of the Electron Conduction Channel in the SiO/Graphite Composite Anode

Conductive atomic force microscopy (C-AFM) is widely used to determine the electronic conductivity of a sample surface with nanoscale spatial resolution. However, the origin of possible artifacts has not been widely researched, hindering the accurate and reliable interpretation of C-AFM imaging results. Herein, artifact-free C-AFM is used to observe the electron conduction channels in Si-based composite anodes. The origin of a typical C-AFM artifact induced by surface morphology is investigated using a relevant statistical method that enables visualization of the contribution of artifacts in each C-AFM image. The artifact is suppressed by polishing the sample surface using a cooling cross-section polisher, which is confirmed by Pearson correlation analysis. The artifact-free C-AFM image was used to compare the current signals (before and after cycling) from two different composite anodes comprising single-walled carbon nanotubes (SWCNTs) and carbon black as conductive additives. The relationship between the electrical degradation and morphological evolution of the active materials depending on the conductive additive is discussed to explain the improved electrical and electrochemical properties of the electrode containing SWCNTs

Metal–Organic Framework-Derived Magnesium Oxide@Carbon Interlayer for Stable Lithium–Sulfur Batteries

Lithium sulfur (Li–S) batteries represent a promising future battery technology. However, the low electrical conductivity of solid-state sulfur species (S, Li2S2, and Li2S) and the polysulfide shuttle effect deteriorate their practical capacity and cycling retention. Herein, we present an interlayer composed of magnesium oxide (MgO) nanoparticles and carbon matrix for the Li–S batteries. In the composite, MgO can capture dissolved polysulfides that diffuse to the carbon matrix along the oxide surface for further reduction reactions. As a novel precursor to produce the composite structure, a Mg metal–organic-framework, Mg-MOF-74, is adopted and synthesized on a free-standing carbon paper (MOF/C-paper). Through pyrolysis, Mg-MOF-74 is converted into highly porous carbon containing uniformly distributed MgO nanoparticles (MgO@C/C-paper). The Li–S cells assembled with MgO@C/C-paper and C-paper interlayer show significantly higher initial capacities (980 and 898 mAh g–1, respectively) than the interlayer-free cell (729 mAh g–1) owing to the conductive interlayers. After 200 cycles at 0.2 C, the MgO@C/C-paper cell presents a cycle retention (78.3%) superior to that of the C-paper cell (76.5%). With a higher sulfur loading of 3.3 mg cm–2, the MgO@C/C-paper cell exhibits an even higher capacity retention (80.1%) than the C-paper cell (54.6%) after 100 cycles. The excellent cycle stability of the MgO@C/C-paper cell over the C-paper cell demonstrates that the unique structure of the MOF-derived MgO@C is highly effective in anchoring and reutilizing dissolved polysulfides

Lead-Free Inorganic Nanoparticles of Perovskite Embedded within Waterproof Nanofiber Films for White Color Emission

Organic polymers can enhance the environmental stability of inorganic perovskite nanocrystals (IPNCs) by encapsulation. We fabricated lead-free IPNCs embedded in waterproof and luminous polymer fibers. The encapsulated perovskite nanocrystals within polystyrene (PS) polymers, CsCu2I3@PS (Y-fiber), and Cs3Cu2I5@PS (B-fiber) were prepared by one-step electrospinning of the solutions containing the precursors (CsI and CuI) and PS. The embedded nanocrystals had highly uniform sizes, spatial distribution, and well-developed crystal structures. The Y- and B-fibers showed yellow and blue emission under ultraviolet (UV) light, respectively, and a white emission fiber layer was fabricated via dual-nozzle coelectrospinning using CsCu2I3 and Cs3Cu2I5 precursor solutions. The as-prepared B-fibers exhibited improved water stability without changing the crystal structure and photoluminescence (PL) emission in deionized water for 20 days. To enhance environmental stability and mechanical properties, transparent poly­(dimethylsiloxane) (PDMS) films containing IPNCs@PS fibers presented strong PL emission without peak shift under 100% tensile strain, indicating highly flexible and humidity-durable characteristics

DataSheet_1_Identification of B cell subsets based on antigen receptor sequences using deep learning.docx

B cell receptors (BCRs) denote antigen specificity, while corresponding cell subsets indicate B cell functionality. Since each B cell uniquely encodes this combination, physical isolation and subsequent processing of individual B cells become indispensable to identify both attributes. However, this approach accompanies high costs and inevitable information loss, hindering high-throughput investigation of B cell populations. Here, we present BCR-SORT, a deep learning model that predicts cell subsets from their corresponding BCR sequences by leveraging B cell activation and maturation signatures encoded within BCR sequences. Subsequently, BCR-SORT is demonstrated to improve reconstruction of BCR phylogenetic trees, and reproduce results consistent with those verified using physical isolation-based methods or prior knowledge. Notably, when applied to BCR sequences from COVID-19 vaccine recipients, it revealed inter-individual heterogeneity of evolutionary trajectories towards Omicron-binding memory B cells. Overall, BCR-SORT offers great potential to improve our understanding of B cell responses.</p

Thin Nickel Layer with Embedded WC Nanoparticles for Efficient Oxygen Evolution

Developing active and stable electrocatalysts for the oxygen evolution reaction (OER) is essential to enhance the efficiency of water splitting. Herein, we report a nickel/tungsten carbide (Ni/WC) composite catalyst in which WC nanoparticles are embedded underneath thin Ni layers as a highly active OER catalyst in an alkaline electrolyte. The thin Ni layer has a modulated electronic structure stemming from the interaction with the WC. The Ni/WC composite exhibits excellent OER activity and durability in a 1 M KOH solution. The turnover frequency of the Ni/WC composite (0.58 s–1) is increased by approximately 5.8 times relative to that of the Ni nanoparticles (0.10 s–1). The significant increase in catalytic activity of the Ni/WC composite can be attributed to the adsorption property change originating from the interaction between the Ni layers and the WC nanoparticles. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculation results show that the electronic structure of the Ni layers can change due to electron transfers from the WC nanoparticles to the Ni layer across their interfaces. This electronic structure change reduces the kinetic barrier of the rate-determining step of the OER pathway by lowering the O* binding energy that impedes the OER kinetics. As a result, the overall OER on the Ni/WC surface is accelerated. These findings suggest a unique strategy by which to enhance the catalytic activity of the OER in an alkaline electrolyte

Additional file 1 of PHLI-seq: constructing and visualizing cancer genomic maps in 3D by phenotype-based high-throughput laser-aided isolation and sequencing

Supplementary notes, supplementary figures, and supplementary tables. (DOCX 19232 kb

Formation and Encapsulation of All-Inorganic Lead Halide Perovskites at Room Temperature in Metal–Organic Frameworks

Improving the stability and tuning the optical properties of semiconducting perovskites are vital for their applications in advanced optoelectronic devices. We present a facile synthetic method for hybrid composites of perovskites and metal–organic frameworks (MOFs). A simple two-step solution-based method without organic surfactants was employed to make all-inorganic lead-halide perovskites (CsPbX3; X = Cl, Br, I, or mixed halide compositions) form directly in the pores of MIL-101 MOF. That is, a polar organic solution of lead halide (PbX2) was impregnated into the MOF pores to give PbX2@MIL-101, which was then subjected to a perovskite-formation reaction with cesium halide (CsX) dissolved in methanol. The compositions of the halogen anions in the perovskites can be modulated with various halide precursors, leading to CsPbX3@MIL-101 composites with X3 = Cl3, Cl2Br, Br2Cl, Br3, Br2I, I2Br, and I3 that exhibit gradual variation of band gap energies and tuned emission wavelengths from 417 to 698 nm