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Nano Research 2021年第6期14卷 1625-1649页

作者： Hui Cai Yiling Yu Yu-Chuan Lin Alexander A.Puretzky david b.geohegan Kai Xiao Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTN37831USA

Two-dimensional(2D)materials hold great promise for applications in optoelectronics,quantum information science,and energy conversion due to their remarkable properties imbued by their physical *** heterogeneities in their intrinsic structure are the major challenges limiting their synthesis and predictable properties,they also provide a pathway to controllably tune the properties and broaden the potential of 2D *** that can be tailored,including defects,dopants,strain,edges,and layer stackings offer transformative opportunities in heterogeneous 2D materials through the introduction of novel properties for technological *** article provides a review of recent progress in studying heterogeneities in 2D *** review uses examples from our work to develop a strategy to understand the heterogeneities across multiple length scales to link the effect of heterogeneity at the nanoscale with the macroscale properties of 2D *** describe specific types of heterogeneities and explore novel synthesis and processing methods for their controlled production with example of the potential impact and applications enabled by their intriguing ***,we provide a perspective on how to extend the range of tunable properties through further engineering the heterogeneities in 2D materials.

关键词： wo-dimensional(2D)materials heterogeneity defect strain grain boundary heterostructures phase

Deep learning analysis of defect and phase evolution during electron beam-induced transformations in WS_(2)

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npj Computational Materials 2019年第1期5卷 1039-1046页

作者： Artem Maksov Ondrej Dyck Kai Wang Kai Xiao david b.geohegan bobby G.Sumpter Rama K.Vasudevan Stephen Jesse Sergei V.Kalinin Maxim Ziatdinov Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTN 37831USA Institute for Functional Imaging of Materials Oak Ridge National LaboratoryOak RidgeTN 37831USA bredesen Center for Interdisciplinary Research University of TennesseeKnoxvilleTN 37996USA Computational Sciences&Engineering Division Oak Ridge National LaboratoryOak RidgeTN 37831USA

Recent advances in scanning transmission electron microscopy(STEM)allow the real-time visualization of solid-state transformations in materials,including those induced by an electron beam and temperature,with atomic ***,despite the ever-expanding capabilities for high-resolution data acquisition,the inferred information about kinetics and thermodynamics of the process,and single defect dynamics and interactions is *** is due to the inherent limitations of manual ex situ analysis of the collected volumes of *** circumvent this problem,we developed a deep-learning framework for dynamic STEM imaging that is trained to find the lattice defects and apply it for mapping solid state reactions and transformations in layered WS_(2).The trained deep-learning model allows extracting thousands of lattice defects from raw STEM data in a matter of seconds,which are then classified into different categories using unsupervised clustering *** further expanded our framework to extract parameters of diffusion for sulfur vacancies and analyzed transition probabilities associated with switching between different configurations of defect complexes consisting of Mo dopant and sulfur vacancy,providing insight into pointdefect dynamics and *** approach is universal and its application to beam-induced reactions allows mapping chemical transformation pathways in solids at the atomic level.

关键词： defect beam sulfur

Mapping mesoscopic phase evolution during E-beam induced transformations via deep learning of atomically resolved images

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npj Computational Materials 2018年第1期4卷 396-404页

作者： Rama K.Vasudevan Nouamane Laanait Erik M.Ferragut Kai Wang david b.geohegan Kai Xiao Maxim Ziatdinov Stephen Jesse Ondrej Dyck Sergei V.Kalinin Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTN 37831USA Institute for Functional Imaging of Materials Oak Ridge National LaboratoryOak RidgeTN 37831USA Computational Sciences and Engineering Division Oak Ridge National LaboratoryOak RidgeTN 37831USA Quantum Computing Institute Oak Ridge National LaboratoryOak RidgeTN 37831USA UnitedHealth Group PO Box 1459Minneapolis 55440 MNUSA

Understanding transformations under electron beam irradiation requires mapping the structural phases and their evolution in real *** date,this has mostly been a manual endeavor comprising difficult frame-by-frame analysis that is simultaneously tedious and prone to ***,we turn toward the use of deep convolutional neural networks(DCNN)to automatically determine the bravais lattice symmetry present in atomically resolved images.A DCNN is trained to identify the bravais lattice class given a 2D fast Fourier transform of the input ***-Carlo dropout is used for determining the prediction probability,and results are shown for both simulated and real atomically resolved images from scanning tunneling microscopy and scanning transmission electron microscopy.A reduced representation of the final layer output allows to visualize the separation of classes in the DCNN and agrees with physical *** then apply the trained network to electron beam-induced transformations in WS2,which allows tracking and determination of growth rate of *** highlight two key aspects of these results:(1)it shows that DCNNs can be trained to recognize diffraction patterns,which is markedly different from the typical“real image”cases and(2)it provides a method with inbuilt uncertainty quantification,allowing the real-time analysis of phases present in atomically resolved images.

关键词： beam evolution atomic

The great catastrophe: causes of the Permo-Triassic marine mass extinction

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National Science Review 2024年第1期11卷 37-50页

作者： Paul b.Wignall david P.G.bond School of Earth & Environment University of Leeds School of Environmental Sciences University of Hull

The marine losses during the Permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). Planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the crisis to a ～55 kyr interval straddling the Permo-Triassic boundary. Many of the losses occur at the beginning and end of this interval painting a picture of a two-phase extinction. Improved knowledge of the extinction has been supported by numerous geochemical studies that allow diverse proposed extinction mechanisms to be studied. A transition from oxygenated to anoxic-euxinic conditions is seen in most sections globally, although the intensity and timing shows regional variability. Decreased ocean ventilation coincides with rapidly rising temperatures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting support from geochemical proxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrophic changes at the end of the Permian was likely Siberian Trap eruptions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. Volcanic winter episodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these episodes(boreal latitudes

关键词： ocean anoxia ocean acidification siltation productivity collapse volcanic winter

Author Correction:Deep learning analysis of defect and phase evolution during electron beam-induced transformations in WS_(2)

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npj Computational Materials 2020年第1期6卷 1547-1547页

作者： Artem Maksov Ondrej Dyck Kai Wang Kai Xiao david b.geohegan bobby G.Sumpter Rama K.Vasudevan Stephen Jesse Sergei V.Kalinin Maxim Ziatdinov Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge USA Institute for Functional Imaging of Materials Oak Ridge National Laboratory Oak Ridge USA bredesen Center for Interdisciplinary Research University of Tennessee Knoxville USA Computational Sciences & Engineering Division Oak Ridge National Laboratory Oak Ridge USA

The original version of the published Article omitted a statement from the Acknowledgements *** Acknowledgements have been updated to include the following:The work on microscopy and synthesis was supported by the *** of Energy,Office of Science,basic Energy Sciences,Materials Sciences and Engineering Division(R.K.V.,S.V.K.,K.W.,K.X.,D.G.).The HTML and PDF versions of the Article have been corrected.

关键词： basic Deep HTML

Author Correction:Mapping mesoscopic phase evolution during E-beam induced transformations via deep learning of atomically resolved images

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npj Computational Materials 2018年第1期4卷 8-8页

In the original version of this Article the term‘rhombohedral’was used incorrectly in place of‘oblique’,and the term‘rhombohedral’was used in Supplementary Figure 5 to describe the simulated lattice but we had instead simulated a rectangular centered *** mentions of‘rhombohedral’have been corrected to‘oblique’in the manuscript,Fig.2 and Fig.4–6,and Supplementary ***,‘centered rectangle’has been corrected to‘rectangular centered lattice’throughout the manuscript to avoid any confusion in terminology.

关键词： centered oblique Figure

A metabolic signalling role for arginine in liver cancer

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Life Metabolism 2024年第1期3卷 1-3页

作者： david Sokolov Lucas b.Sullivan Human biology Division Fred Hutchinson Cancer CenterSeattleWA 98109United States

In addition to their canonical roles in biosynthetic pathways,metabolites can be active participants in oncogenic signal-ling,but our understanding of these signalling mechanisms is *** a recent article published in Cell,Mossmann et *** a novel signalling role for accumulated arginine in hepato-cellular carcinoma(HCC)mediated by the RNA splicing factor and transcriptional modifier RNA-binding protein 39(RbM39).

关键词： incomplete cancer

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Rational molecular design of efficient yellow-red dendrimer TADF for solution-processed OLEDs: a combined effect of substitution position and strength of the donors

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Science China Chemistry 2024年第5期67卷 1613-1623页

作者： Changfeng Si Dianming Sun Tomas Matulaitis david b.Cordes Alexandra M.Z.Slawin Eli Zysman-Colman Organic Semiconductor Centre EaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsKY169STUK

The development of high-performance solution-processed red organic light-emitting diodes(OLEDs) remains a challenge,particularly in terms of maintaining efficiency at high luminance. Here, we designed and synthesized four novel orange-red thermally activated delayed fluorescence(TADF) dendrimers that are solution-processable: 2GCz bP, 2DPACz bP, 2FbP2GCz and 2FbP2DPACz. We systematically investigated the effect of substitution position and strength of donors on the optoelectronic properties. The reverse intersystem crossing rate constant(kRISC) of the emitters having donors substituted at positions 11and 12 of the dibenzo[a,c]phenazine(bP) is more than 10-times faster than that of compounds substituted having donors substituted at positions 3 and 6. Compound 2DPACz bP, containing stronger donors than 2GCz bP, exhibits a red-shifted emission and smaller singlet-triplet energy splitting, ΔE_(ST), of 0.01 e V. The solution-processed OLED with 10 wt% 2DPACz bP doped in m CP emitted at 640 nm and showed a maximum external quantum efficiency(EQE_(max)) of 7.8%, which was effectively maintained out to a luminance of 1,000 cd m-2. Such a device's performance at relevant display luminance is among the highest for solution-processed red TADF OLEDs. The efficiency of the devices was improved significantly by using 4Cz IPN as an assistant dopant in a hyperfluorescence(HF) configuration, where the 2DPACz bP HF device shows an EQEmaxof 20.0% at λEL of 605 nm and remains high at 11.8% at a luminance of 1,000 cd m-2, which makes this device one of the highest efficiency orange-to-red HF SP-OLEDs to date.

关键词： thermally activated delayed fluorescence solution-processing red OLEDs dibenzo[a,c]phenazine dendrimers

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A systematic scoping review of study methodology for randomized controlled trials investigating probiotics in athletic and physically active populations

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Journal of Sport and Health Science 2024年第1期13卷 61-71页

作者： Alex E.Mohr david b.Pyne Geovana Silva Fogaça Leite Deborah Akins Jamie Pugh College of Health Solutions Arizona State UniversityPhoenixAZ 85004USA Research Institute for Sport and Exercise University of CanberraCanberraACT 2617Australia Laboratory of Functional Fermented Food Faculty of Pharmaceutical SciencesUniversity of São PauloSão Paulo 05508-030Brazil Research Institute for Sport and Exercise Sciences Liverpool John Moores UniversityLiverpool L33AFUK

background:The purported ergogenic and health effects of probiotics have been a topic of great intrigue among researchers,practitioners,and the lay public *** has also been an increased research focus within the realm of sports science and exercise medicine on the athletic gut ***,compared to other ergogenic aids and dietary supplements,probiotics present unique study *** objectives of this systematic scoping review were to identify and characterize study methodologies of randomized controlled trials investigating supplementation with probiotics in athletes and physically active ***:Four databases(MEDLINE,CINAHL,Cochrane CENTRAL,and Cochrane Database of Systematic Reviews)were searched for randomized controlled studies involving healthy athletes or physically active *** intervention with probiotics and inclusion of a control and/or placebo group were *** peer-reviewed articles in English were considered,and there were no date *** were extracted and presented in tabular form to detail study protocols,characteristics,and *** in randomized controlled trials was determined with the Rob 2.0 ***:A total of 45 studies were included in the review,with 35 using a parallel group design and 10 using a cross-over *** half the studies used a single probiotic and the other half a multi-strain *** probiotic dose ranged from 2×10^(8)to 1×10^(11)colony forming units daily,and the length of intervention was between 7 and 150 *** than half the studies directly assessed gastrointestinal symptoms,gut permeability,or the gut *** sex ratio of participants was heavily weighted toward males,and only 3 studies exclusively investigated ***-level adverse events were reported in only 2 studies,although the methodology of reporting varied *** risk of bias was generally low,although details on randomization were lacking in some s

关键词： Exercise Experimental methodology Gastrointestinal symptoms Gut microbiota Probiotic supplementation

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Inflammatory Factor IL1αInduces Aberrant Astrocyte Proliferation in Spinal Cord Injury Through the Grin2c/Ca^(2+)/CaMK2b Pathway

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Neuroscience bulletin 2024年第4期40卷 421-438页

作者： Yu Xia Lu Ding Changlin Zhang Qi Xu Ming Shi Tianshun Gao Feng-Quan Zhou david Y.b.Deng Scientific Research Center The Seventh Affiliated Hospital of Sun Yat-sen UniversityShenzhen518107China Department of Gynecology The Seventh Affiliated Hospital of Sun Yat-sen UniversityShenzhen518107China Pelvic Floor Disorders Center The Seventh Affiliated Hospital of Sun Yat-sen UniversityShenzhen518107China big Data Center The Seventh Affiliated Hospital of Sun Yat-sen UniversityShenzhen518107China Sir Run Run Shaw Hospital Zhejiang University School of MedicineHangzhou310016China Orthopaedic and Neurological Repair Center The Seventh Affiliated Hospital of Sun Yat-sen UniversityShenzhen518107China

Spinal cord injury(SCI)is one of the most devastating traumas,and the aberrant proliferation of astrocytes usually causes neurological ***,the mechanism underlying astrocyte over-proliferation after SCI is ***2c(glutamate ionotropic receptor type 2c)plays an essential role in cell *** bioinformatic analysis indicated that Grin2c and Ca^(2+)transport functions were inhibited in astrocytes after *** of Grin2c stimulated astrocyte proliferation by inhibiting the Ca^(2+)/calmodulin-dependent protein kinase 2b(CaMK2b)pathway in *** screening different inflammatory factors,interleukin 1α(IL1α)was further found to inhibit Grin2c/Ca^(2+)/CaMK2b and enhance astrocyte proliferation in an oxidative damage *** of IL1αusing neutralizing antibody resulted in increased Grin2c expression and the inhibition of astrocyte proliferation ***,this study suggests that IL1αpromotes astrocyte proliferation by suppressing the Grin2c/Ca^(2+)/CaMK2b pathway after SCI,revealing a novel pathological mechanism of astrocyte proliferation,and may provide potential targets for SCI repair.

关键词： IL1α Grin2c Astrocyte Spinal cord injury