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Herein, the microstructure stability of a newly developed hot‐working die (HWD700) steel at elevated temperatures up to 700 °C is investigated using transmission electron microscopy (TEM), selected‐area electron diffraction, energy‐dispersive spectrometer, and high‐resolution transmission electron microscope. The results show that the HWD700 steel exhibits a higher thermal stability than the commercial H13 steel when the temperature is up to 700 °C. After quenching and tempering, high densities of intra‐lath rodlike and inter‐lath spherical MC nano‐carbides and inter‐lath strip‐like M7C3 nano‐carbides are observed in the HWD700 steel. These carbides remain nanoscale at temperatures up to 700 °C. For comparison, rod‐shaped MC nano‐carbides in the tempered H13 steel tend to coarsen and transform into larger M23C6 carbides at temperatures up to 650 °C. The TEM observation further reveals that the interface misfit between the MC nano‐carbide and matrix in the HWD700 steel is as low as 0.88%, lower than that of 14.8% in the H13 steel. This can be the main reason for the improved stability of the HWD700 steel by pinning dislocations and grain boundaries and thereby hindering the recrystallization process at an elevated temperature. [ABSTRACT FROM AUTHOR]

Interfacial atomic configuration plays a vital role in the structural stability and functionality of nanocomposites composed of metal nanoparticles (NPs) and two−dimensional semiconductors. In situ transmission electron microscope (TEM) provides a real−time technique to observe the interface structure at atomic resolution. Herein, we loaded bimetallic NiPt truncated octahedral NPs (TONPs) on MoS2 nanosheets and constructed a NiPt TONPs/MoS2 heterostructure. The interfacial structure evolution of NiPt TONPs on MoS2 was in situ investigated using aberration−corrected TEM. It was observed that some NiPt TONPs exhibited lattice matching with MoS2 and displayed remarkable stability under electron beam irradiation. Intriguingly, the rotation of an individual NiPt TONP can be triggered by the electron beam to match the MoS2 lattice underneath. Furthermore, the coalescence kinetics of NiPt TONPs can be quantitatively described by the relationship between neck radius (r) and time (t), expressed as rn = Kt. Our work offers a detailed analysis of the lattice alignment relationship of NiPt TONPs on MoS2, which may enlighten the design and preparation of stable bimetallic metal NPs/MoS2 heterostructures. [ABSTRACT FROM AUTHOR]

Understanding the mechanism of nucleation and growth of nanocrystals is crucial for designing and regulating the structure and properties of nanocrystals. However, the process from molecules to nanocrystals remains unclear because of the rapid and complicated dynamics of evolution under reaction conditions. Here, the complete evolution process of solid‐phase chloroplatinic acid during the electron beam irradiation triggered reduction and nucleation of platinum nanocrystals is recorded. Aberration‐corrected environmental transmission electron microscopy is used for direct visualization of the dynamic evolution from H2PtCl6 to Pt nanocrystals at the atomic scale, including the formation and growth of amorphous clusters, crystallization, and growth of clusters, and the ripening of Pt nanocrystals. At the first two stages, there exists a critical size of ≈2.0 nm, which represents the start of crystallization. Crystallization from the center and density fluctuation are observed in the second stage of the crystallization of a few clusters with a size obviously larger than the critical size. The work provides valuable information to understand the kinetics of the early stage of nanocrystal nucleation and crystallization at atomic scale. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) MoS2 with appealing physical properties is a promising candidate for next-generation electronic and optoelectronic devices, where the ultrathin MoS2 is usually laid on or gated by a dielectric oxide layer. The oxide/MoS2 interfaces widely existing in these devices have significant impacts on the carrier transport of the MoS2 channel by diverse interface interactions. Artificial design of the oxide/MoS2 interfaces would provide an effective way to break through the performance limit of the 2D devices but has yet been well explored. Here, we report a high-performance MoS2-based phototransistor with an enhanced photoresponse by interfacing few-layer MoS2 with an ultrathin TiO2 layer. The TiO2 is deposited on MoS2 through the oxidation of an e-beam-evaporated ultrathin Ti layer. Upon a visible-light illumination, the fabricated TiO2/MoS2 phototransistor exhibits a responsivity of up to 2,199 A/W at a gate voltage of 60 V and a detectivity of up to 1.67 × 1013 Jones at a zero-gate voltage under a power density of 23.2 µW/mm2. These values are 4.0 and 4.2 times those of the pure MoS2 phototransistor. The significantly enhanced photoresponse of TiO2/MoS2 device can be attributed to both interface charge transfer and photogating effects. Our results not only provide valuable insights into the interactions at TiO2/MoS2 interface, but also may inspire new approach to develop other novel optoelectronic devices based on 2D layered materials. [ABSTRACT FROM AUTHOR]

Highly uniform dispersed bimetallic Pt3Zn alloy nanocrystals (NCs) with unique geometries are obtained via a facile one‐pot synthesis process by regulating different reductants. To investigate the morphology and composition of the prepared catalysts, the transmission electron microscopy, X‐ray diffraction and X‐ray photoelectron spectroscopy are utilized. Electrochemical measurements reveal that the Pt3Zn NCs significantly exhibited larger electrochemically active surface areas and excellent catalytic activity towards electro‐oxidation of methanol and ethanol in comparison to the commercial Pt/C. The optimized Pt3Zn (AA) NCs exhibit excellent mass activities in both methanol oxidation reaction (1251.4 mA mgPt−1) and ethanol oxidation reaction (975.7 mA mgPt−1) in acidic media, which are respectively 4.28 times and 3.02 times higher than those of commercial Pt/C. Moreover, the Pt3Zn NCs show a higher stability and better resistance to the COads poisoning. The activity enhancements are attributed to electronic effects and a bifunctional mechanism. [ABSTRACT FROM AUTHOR]

The morphology and structural stability of metal/2D semiconductor interfaces strongly affect the performance of 2D electronic devices and synergistic catalysis. However, the structural evolution at the interfaces has not been well explored particularly at atomic resolution. In this work, we study the structural evolution of Au nanoparticles (NPs) on few-layer MoS2 by high resolution transmission electron microscope (HRTEM) and quantitative high-angle annular dark field scanning TEM. It is found that in the transition of Au from nanoparticles to dendrites, a dynamically epitaxial alignment between Au and MoS2 lattices is formed, and Moiré patterns can be directly observed in HRTEM images due to the mismatch between Au and MoS2 lattices. This epitaxial alignment can occur in ambient conditions, and can also be accelerated by the irradiation of high-energy electron beam. In situ observation clearly reveals the rotation of Au NPs, the atom migration inside Au NPs, and the transfer of Au atoms between neighboring Au NPs, finally leading to the formation of epitaxially aligned Au dendrites on MoS2. The structural evolution of metal/2D semiconductor interfaces at atomic scale can provide valuable information for the design and fabrication of the metal/2D semiconductor nano-devices with desired physical and chemical performances. [ABSTRACT FROM AUTHOR]

5a: The representative ALP staining images of Azo+si-glp-1r-1 and Azo+si-glp-1r-2 are the same The authors provided the raw data for validation. Retraction Note: Stem Cell Research & Therapy (2018) 9:57 https://doi.org/10.1186/s13287-... The Editors-in-Chief have retracted this article at the authors' request. Retraction Note: Azoramide, a novel regulator, favors adipogenesis against osteogenesis through inhibiting the GLP-1 receptor-PKA- -catenin pathway. [Extracted from the article]

COVID-19 mRNA vaccine-associated dermatomyositis (DM) with the anti-TIF-1y-positive case was first reported in 2021.[2] Two reports about MDA5-DM patients after mRNA or adenovirus vector COVID-19 vaccines were searched out in the PubMed, Science Direct and SCOPUS by June 2022.[[3]] We first reported an MDA5-DM with rapid progressive interstitial lung disease (RP-ILD) patient after an inactivation COVID-19 vaccine, exhibiting time course of the disease development. Dear Editor, During the epidemic of COVID-19 disease worldwide, applying COVID-19 vaccination can effectively protect humans from serious symptoms and help reduce long-term effects.[1] However, COVID-19 vaccines have been linked to some potential side effects. A case of Anti-MDA5-Positive dermatomyositis after inactivated COVID-19 vaccine. [Extracted from the article]

Metal sulfides electrodeposition in sulfur cathodes mitigates the shuttle effect of polysulfides to achieve high Coulombic efficiency in secondary metal-sulfur batteries. However, fundamental understanding of metal sulfides electrodeposition and kinetics mechanism remains limited. Here using room-temperature sodium-sulfur cells as a model system, we report a Mo5N6 cathode material that enables efficient Na2S electrodeposition to achieve an initial discharge capacity of 512 mAh g−1 at a specific current of 1 675 mA g−1, and a final discharge capacity of 186 mAh g−1 after 10,000 cycles. Combined analyses from synchrotron-based spectroscopic characterizations, electrochemical kinetics measurements and density functional theory computations confirm that the high d-band position results in a low Na2S2 dissociation free energy for Mo5N6. This promotes Na2S electrodeposition, and thereby favours long-term cell cycling performance. Incomplete conversion of sodium polysulfides represents a significant issue in room-temperature sodium-sulfur batteries. Here, the authors propose Mo5N6 as an electrocatalyst for efficient Na2S electrodeposition and improved cell cycling performances. [ABSTRACT FROM AUTHOR]

Background: The reciprocal fate decision of mesenchymal stem cells (MSCs) to either bone or adipocytes is determined by Wnt-related signaling and the glucagon-like peptide-1 receptor (GLP-1R). Azoramide, an ER stress alleviator, was reported to have an antidiabetic effect. In this study, we investigated the function of azoramide in regulating the lineage determination of MSCs for either adipogenic or osteogenic differentiation. Methods: In this study, microcomputed tomography and histological analysis on bone morphogenetic protein (BMP)2-induced parietal periosteum bone formation assays, C3H10T1/2 and mouse bone marrow MSC-derived bone formation and adipogenesis assays, and specific staining for bone tissue and lipid droplets were used to evaluate the role of azoramide on the lineage determination of MSC differentiation. Cells were harvested for Western blot and quantitative real-time polymerase chain reaction (PCR), and immunofluorescence staining was used to explore the potential mechanism of azoramide for regulating MSC differentiation. Results: Based on MSC-derived bone formation assays both in vivo and in vitro, azoramide treatment displayed a cell fate determining ability in favor of adipogenesis over osteogenesis. Further mechanistic characterizations disclosed that both the GLP-1R agonist peptide exendin-4 (Ex-4) and GLP-1R small interfering (si)RNA abrogated azoramide dual effects. Moreover, cAMP-protein kinase A (PKA)-mediated nuclear β-catenin activity was responsible for the negative function of azoramide on bone formation in favor of adipogenesis. Conclusions: These data provide the first evidence to show that azoramide may serve as an antagonist against GLP-1R in MSC lineage determination. [ABSTRACT FROM AUTHOR]