Thermal barrier coatings (TBCs) can effectively protect the alloy substrate of hot components in aeroengines or land-based gas turbines by the thermal insulation and corrosion/erosion resistance of ...the ceramic top coat. However, the continuous pursuit of a higher operating temperature leads to degradation, delamination, and premature failure of the top coat. Both new ceramic materials and new coating structures must be developed to meet the demand for future advanced TBC systems. In this paper, the latest progress of some new ceramic materials is first reviewed. Then, a comprehensive spalling mechanism of the ceramic top coat is summarized to understand the dependence of lifetime on various factors such as oxidation scale growth, ceramic sintering, erosion, and calcium-magnesium-aluminium-silicate (CMAS) molten salt corrosion. Finally, new structural design methods for high-performance TBCs are discussed from the perspectives of lamellar, columnar, and nanostructure inclusions. The latest developments of ceramic top coat will be presented in terms of material selection, structural design, and failure mechanism, and the comprehensive guidance will be provided for the development of next-generation advanced TBCs with higher temperature resistance, better thermal insulation, and longer lifetime.
A new approach was designed to synthesize tin‐nanoparticles encapsulated in elastic hollow carbon spheres (TNHCs) with uniform size, in which tin nanoparticles with a diameter <100 nm were ...encapsulated in one thin hollow carbon sphere. The content of tin is up to over 70% by weight, andthe void volume inside the TNHCsis as high as 70–80%, which can accommodate the volume after expansion. This tin‐based nanocomposite exhibits a great potential as an anode materials for lithium‐ion batteries.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
COVID-19 is associated with 5.1% mortality. Although the virological, epidemiological, clinical, and management outcome features of COVID-19 patients have been defined rapidly, the inflammatory and ...immune profiles require definition as they influence pathogenesis and clinical expression of COVID-19. Here we show lymphopenia, selective loss of CD4+ T cells, CD8+ T cells and NK cells, excessive T-cell activation and high expression of T-cell inhibitory molecules are more prominent in severe cases than in those with mild disease. CD8+ T cells in patients with severe disease express high levels of cytotoxic molecules. Histochemical studies of lung tissue from one fatality show sub-anatomical distributions of SARS-CoV-2 RNA and massive infiltration of T cells and macrophages. Thus, aberrant activation and dysregulation of CD8+ T cells occur in patients with severe COVID-19 disease, an effect that might be for pathogenesis of SARS-CoV-2 infection and indicate that immune-based targets for therapeutic interventions constitute a promising treatment for severe COVID-19 patients.
Oxidative dehydrogenation of propane to olefins is a promising alternative route to industrialized direct dehydrogenation, but encounters the difficulty in selectivity control for olefins because of ...the overoxidation reactions that produce a substantial amount of undesired CO2. Here we report edge‐hydroxylated boron nitride, a metal‐free catalyst, that efficiently catalyzed dehydrogenation of propane to propylene with superior selectivity (80.2 %) but with only negligible CO2 formation (0.5 %) at a given propane conversion of 20.6 %. Remarkable stability was evidenced by the operation of a 300 h test with steady conversion and product selectivity. The active BNO. site, generated dynamically through hydrogen ion of B−OH groups by molecular oxygen, triggered propane dehydrogenation by selectively breaking the C−H bond but simultaneously shut off the pathway of propylene overoxidation towards CO2.
Olefin generation without a metal: Edge‐hydroxylated boron nitride shows superior selectivity for the oxidative dehydrogenation of propane to propylene with only negligible CO2 formation. The dynamically generated active BNO. site triggers propane dehydrogenation by selectively breaking the C−H bond by concomitantly avoiding propylene oxidation to CO2.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Depending on the reactant property and reaction mechanism, one major regioisomer can be favored in a reaction that involves multiple active sites. Herein, an orthogonal regulation of nucleophilic and ...electrophilic sites in the regiodivergent hydroamination of isoprene with indazoles is demonstrated. Under Pd‐hydride catalysis, the 1,2‐ or 4,3‐insertion pathway with respect to the electrophilic sites on isoprene could be controlled by the choice of ligands. In terms of the nucleophilic sites on indazoles, the reaction occurs at either the N1‐ or N2‐position of indazoles is governed by the acid co‐catalysts. Preliminary experimental studies have been performed to rationalize the mechanism and regioselectivity. This study not only contributes a practical tool for selective functionalization of isoprene, but also provides a guide to manipulate the regioselectivity for the N‐functionalization of indazoles.
The Pd‐catalyzed regiodivergent coupling reactions between indazoles and isoprene have been developed through the orthogonal regulation of nucleophilic and electrophilic sites.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Skeletal reorganization reactions have emerged as an intriguing tool for converting readily available compounds into complicated molecules inaccessible by traditional methods. Herein, we report a ...unique skeleton‐reorganizing coupling reaction of cycloheptatriene and cycloalkenones with amines. In the presence of Rh/acid catalysis, cycloheptatriene can selectively couple with anilines to deliver fused 1,2‐dihydroquinoline products. Mechanistic studies indicate that the retro‐Mannich type ring‐opening and subsequent intramolecular Povarov reaction account for the ring reorganization. Our mechanistic studies also revealed that skeleton‐reorganizing amination between anilines and cycloalkenones can be achieved with acid. The synthetic utilization of this skeleton‐reorganizing coupling reaction was showcased with a gram‐scale reaction, synthetic derivatizations, and the late‐stage modification of commercial drugs.
An unusual catalytic coupling reaction of cycloheptatriene and cycloalkenones with amines proceeds through a skeleton‐reorganization process for the selective synthesis of fused 1,2‐dihydroquinolines. Mechanistic studies indicate that the reactions proceed through a retro‐Mannich‐type ring‐opening and a subsequent intramolecular Povarov process.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Single-cell omics is the fastest-growing type of genomics data in the literature and public genomics repositories. Leveraging the growing repository of labeled datasets and transferring labels from ...existing datasets to newly generated datasets will empower the exploration of single-cell omics data. However, the current label transfer methods have limited performance, largely due to the intrinsic heterogeneity among cell populations and extrinsic differences between datasets. Here, we present a robust graph artificial intelligence model, single-cell Graph Convolutional Network (scGCN), to achieve effective knowledge transfer across disparate datasets. Through benchmarking with other label transfer methods on a total of 30 single cell omics datasets, scGCN consistently demonstrates superior accuracy on leveraging cells from different tissues, platforms, and species, as well as cells profiled at different molecular layers. scGCN is implemented as an integrated workflow as a python software, which is available at https://github.com/QSong-github/scGCN .
Aberrant activation of Bruton’s tyrosine kinase (BTK) plays an important role in pathogenesis of B-cell lymphomas, suggesting that inhibition of BTK is useful in the treatment of hematological ...malignancies. The discovery of a more selective on-target covalent BTK inhibitor is of high value. Herein, we disclose the discovery and preclinical characterization of a potent, selective, and irreversible BTK inhibitor as our clinical candidate by using in vitro potency, selectivity, pharmacokinetics (PK), and in vivo pharmacodynamic for prioritizing compounds. Compound BGB-3111 (31a, Zanubrutinib) demonstrates (i) potent activity against BTK and excellent selectivity over other TEC, EGFR and Src family kinases, (ii) desirable ADME, excellent in vivo pharmacodynamic in mice and efficacy in OCI-LY10 xenograft models.
Ultrathin, 2D organic layers of sub‐ten nanometer thicknesses and high aspect ratios have received a great deal of attention for their graphene‐like topological features and emerging properties. ...Rational synthetic strategies have led to the realization of periodic 2D layers with unprecedented structural precision. Herein, recent progress on the synthesis of 2D organic layers, including methods based on both non‐covalent and covalent interactions, is summarized, and potential applications are highlighted. Such 2D organic nanostructures have a brilliant future as prospective multifunctional materials, showing great promise as platforms for engineering novel optoelectronic, interfacial, and bioactive properties.
Two‐dimensional organic layers of molecular thickness and large surface area attract great interest from both synthetic chemists and materials scientists. Impressive synthetic progress has been made toward the fabrication of isolated layers with structural precision reaching the atomic level. The most recent synthetic advances are highlighted and linked to their functional perspectives.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Plant trichomes serve as a highly suitable model for investigating cell differentiation at the single‐cell level. The regulatory genes involved in unicellular trichome development in Arabidopsis ...thaliana have been intensively studied, but genes regulating multicellular trichome development in plants remain unclear. Here, we characterized Cucumis sativus (cucumber) trichomes as representative multicellular and unbranched structures, and identified Micro‐trichome (Mict), using map‐based cloning in an F₂ segregating population of 7,936 individuals generated from a spontaneous mict mutant. In mict plants, trichomes in both leaves and fruits, are small, poorly developed, and denser than in the wild type. Sequence analysis revealed that a 2,649‐bp genomic deletion, spanning the first and second exons, occurred in a plant‐specific class I homeodomain‐leucine zipper gene. Tissue‐specific expression analysis indicated that Mict is strongly expressed in the trichome cells. Transcriptome profiling identified potential targets of Mict including putative homologs of genes known in other systems to regulate trichome development, meristem determinacy, and hormone responsiveness. Phylogenic analysis charted the relationships among putative homologs in angiosperms. Our paper represents initial steps toward understanding the development of multicellular trichomes.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
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