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Mass transport in a highly immiscible alloy on extended shear deformation

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Journal of Materials Science & Technology 2023年第3期134卷 197-208页

作者： Miao Song Jia Liu Xiaolong Ma Qin Pang Matthew J.Olszta Joshua Silverstein Madhusudhan R.Pallaka Peter V.Sushko Suveen n.Mathaudhu Cynthia powell Arun Devaraj Bharat Gwalani Physical and Computational Sciences Directorate Pacific Northwest National Laboratory902 Battelle BoulevardRichlandWA 99354USA Energy and Environmental Directorate Pacific Northwest National Laboratory902 Battelle BoulevardRichlandWA 99354USA Material Science and Engineering Program University of CaliforniaRiversideCA92521USA Colorado School of Mines 1500 Illinois St.GoldenCO 8040USA Department of Materials Science and Engineering North Carolina State UniversityRaleighNC27695-7907USA State Key Laboratory of Powder Metallurgy Central South Uni-versityChangsha 410083China

Forced mixing to a single-phase or supersaturated solid solution(SSS)and its prerequisite microstructure evolution in immiscible systems has been a focus of research for fundamental science and practical *** the formation of SSS by shear deformation could enable a material design beyond conventional equilibrium microstructure in immiscible ***,a highly immiscible Cu-50 at.%Cr binary alloy(mixing enthalpy of∼20 kJ mol^(−1))was employed to investigate the microstructure evolution and localized tendencies of SSS during severe shear *** results demonstrate the dislocation mediated microstructural refinement process in each phase of the binary alloy and the mechanisms associated with localized solute supersaturation as a function of shear *** grain refinement in the softer Cu phase occurs owing to the strain localization driving the preferential dynamic *** grain refinement of the Cr phase,however,is enabled by the progressive evolution of grain lamination,splitting,and fragmentation as a function of shear *** solute supersaturation is found to be strongly dependent on the local environments that affect the dislocation activity,including the level of microstructure refinement,the interfacial orientation relationship,the mechanical incompatibility,and the localized preferential phase *** initio simulations confirm that it is more favorable to oxidize Cr than Cu at incoherent Cu/Cr interfaces,limiting the mass transport on an incoherent *** results unveil the mechanism underpinning the non-equilibrium mass transport in immiscible systems upon severe deformation that can be applied to produce immiscible alloys with superior mechanical properties.

关键词： Tribology Immiscible alloys nanostructures Shear deformation Forced mixing Atom probe

Coordinated AR and microRnA regulation in prostate cancer

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Asian Journal of Urology 2020年第3期7卷 233-250页

作者： Ieva Eringyte Joanna n.Zamarbide Losada Sue M.powell Charlotte L.Bevan Claire E.Fletcher Imperial Centre for Translational and Experimental Medicine Department of Surgery and CancerImperial College LondonHammersmith HospitalLondonUnited Kingdom

The androgen receptor(AR)remains a key driver of prostate cancer(PCa)progression,even in the advanced castrate-resistant stage,where testicular androgens are *** is therefore of critical importance to understand the molecular mechanisms governing its activity and regulation during prostate ***(miRs)are small w22 nt noncoding RnAs that regulate target gene,often through association with 30 untranslated regions(30UTRs)of *** display dysregulation during cancer progression,can function as oncogenes or tumour suppressors,and are increasingly recognised as targets or regulators of hormonal ***,understanding factors which modulate miRs synthesis is *** is increasing evidence for complex and dynamic bi-directional cross-talk between the multi-step miR biogenesis cascade and the AR signalling axis in *** review summarises the wealth of mechanisms by which miRs are regulated by AR,and conversely,how miRs impact AR’s transcriptional activity,including that of AR splice *** addition,we assess the implications of the convergence of these pathways on the clinical employment of miRs as PCa biomarkers and therapeutic targets.

关键词： MicroRnA Androgen receptor Androgen Prostate cancer Hormone non-coding RnA

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金属板料逐段成形带法兰零件

锻压技术 1989年第5期14卷 57-61,54页

作者： n. n. powell 董建令剑桥大学

本文研究了采用局部重复成形即增量成形方法成形带法兰型板料金属件的可行性。对该过程进行了有限元分析并发现分析结果与通过实验所测定的变形形状、总的变形力和表面塑性应变很一致。还成功地在型模上用带槽的滚轮成形无起皱外凸(收缩... 详细信息

本文研究了采用局部重复成形即增量成形方法成形带法兰型板料金属件的可行性。对该过程进行了有限元分析并发现分析结果与通过实验所测定的变形形状、总的变形力和表面塑性应变很一致。还成功地在型模上用带槽的滚轮成形无起皱外凸(收缩)法兰。有限元分析结果被用于研究需要满足什么样的条件可以在变形区用条形支承物代替专用型模。在不用专用工具的情况下成功地成形了飞机合金收缩法兰。

关键词：金属板料法兰件逐段成形成形

Arabidopsis ADC1 functions as an nδ-acetylornithine decarboxylase

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Journal of Integrative Plant Biology 2020年第5期62卷 601-613页

作者： Yann-Ru Lou Sheaza Ahmed Jian Yan Adewale M.Adio Hannah M.powell Paul F.Morris Georg Jander Boyce Thompson Institute for Plant Research IthacaNY 14853USA Department of Biological Sciences Bowling Green State UniversityBowling GreenOH 43403USA Key Laboratory of Agro-Environment in the Tropics Ministry of Agriculture and Rural AffairsSouth China Agricultural UniversityGuangzhou 510642China Department of Biochemistry and Molecular Biology Michigan State UniversityEast LansingMI 48824USA Bayer Crop Science 700 Chesterfield Parkway WestChesterfieldMO 63017USA

Polyamines are small aliphatic amines found in almost all organisms,ranging from bacteria to plants and *** most plants,putrescine,the metabolic precursor for longer polyamines,such as spermidine and spermine,is produced from arginine,with either agmatine or ornithine as *** we show that Arabidopsis thaliana(Arabidopsis)arginine de-carboxylase 1(ADC1),one of the two known arginine decarboxylases in Arabidopsis,not only synthesizes agmatine from arginine,but also converts *** to *** analyses indicate that duplication and neofunctionalization of ADC1 and nATA1,the enzymes that synthesize nδ-acetylormithine in Arabidopsis,co-occur in a small number of related species in the *** ADC2,which is localized in the chloroplasts,ADC1 is in the endoplasmic reticulum together with nATA1,an indication that these two enzymes have access to the same substrate ***,these results are con-sistent with a model whereby nATA1 and ADC1 to-gether provide a pathway for the synthesis of n-acetylputrescine in Arabidopsis.

关键词： Arabidopsis Phylogenetic Together

DnA repair and synthetic lethality

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International Journal of Oral Science 2011年第4期3卷 176-179页

作者： Gong-she Guo Feng-mei Zhang Rui-jie Gao Robert Delsite Zhi-hui Feng Simon n. powell School of Public Health Shandong University Jinan 250012 China Second People＇s Hospital of Weifang Weifang 261041 China Department of Radiation Oncology Washington University in St Louis St Louis MO 63108 USA Department of Radiation Oncology Memorial Sloan Kettering Cancer Center New York NY10065 USA

Tumors often have DnA repair defects, suggesting additional inhibition of other DnA repair pathways in tumors may lead to synthetic lethality. Accumulating data demonstrate that DnA repair-defective tumors, in particular homologous recombination （HR）, are highly sensitive to DnA-damaging agents. Thus, HR-defective tumors exhibit potential vulnerability to the synthetic lethality approach, which may lead to new therapeutic strategies. It is well known that poly （adenosine diphosphate （ADP）-ribose） polymerase （PARP） inhibitors show the synthetically lethal effect in tumors defective in BRCA1 or BRCA2 genes encoded proteins that are required for efficient HR. In this review, we summarize the strategies of targeting DnA repair pathways and other DnA metabolic functions to cause synthetic lethality in HR-defective tumor cells.

关键词： DnA repair homologous recombination synthetic lethality BRCA Rad52

Maintenance of Species Differences in Closely Related Tetraploid Parasitic Euphrasia (Orobanchaceae) on an Isolated Island

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Plant Communications 2020年第6期1卷 85-99页

作者： Hannes Becher Max R.Brown Gavin.powell Chris Metherell nick J.Riddifordand Alex D.Twyford University of Edinburgh School of Biological SciencesInstitute of Evolutionary BiologyCharlotte Auerbach RoadEdinburgh EH93FLUK Royal Botanic Garden Edinburgh 20A Inverleith RowEdinburgh EH35LRUK Botanical Society of Britain and Ireland 4 High Firs CrescentHarpendenHertfordshire AL51NAUK Schoolton Fair IsleShetland ZE29JUUK

Polyploidy is pervasive in angiosperm evolution and plays important roles in adaptation and ***,polyploid groups are understudied due to complex sequence homology,challenging genome assembly,and taxonomic ***,we study adaptive divergence in taxonomically complex eyebrights(Euphrasia),where recent divergence,phenotypic plasticity,and hybridization blur species *** focus on three closely related tetraploid species with contrasting ecological preferences that are sympatric on Fair Isle,a small isolated island in the British *** a common garden experiment,we show a genetic component to the morphological differences present between these *** wholegenome sequencing and a novel k-mer approach we call“Tetmer”,we demonstrate that the species are of allopolyploid origin,with a sub-genome divergence of approximately 5%.Using2 million SnPs,we show sub-genome homology across species,with a very low sequence divergence characteristic of recent *** genetic variation is broadly structured by species,with clear divergence of Fair Isle heathland Euphrasia micrantha,while grassland Euphrasia arctica and coastal Euphrasia foulaensis are more closely ***,we show that tetraploid Euphrasia is a system of allopolyploids of postglacial species divergence,where adaptation to novel environments may be conferred by old variants rearranged into new genetic lineages.

关键词： incipient speciation k-mer spectrum allopolyploidy tetraploid divergence with gene flow taxonomic complexity

Computational prediction and validation of specific EmbR binding site on PknH

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Synthetic and Systems Biotechnology 2021年第4期6卷 429-436页

作者： Insung na Huanqin Dai Hantian Li Anvita Gupta David Kreda powell Zhang Xiangyin Chen Lixin Zhang Gil Alterovitz Computational Health Informatics Program Boston Children’s Hospital/Harvard Medical SchoolBostonMA 02115USA Department of Medicine Brigham and Women’s Hospital/Harvard Medical SchoolBostonMA 02115USA State Key Laboratory of Mycology Institute of MicrobiologyBeijing100101 China Department of Computer Sciences Stanford UniversityStanford CA 94305USA Center for Biomedical Informatics Harvard Medical SchoolBostonMA 02115USA State Key Laboratory of Bioreactor Engineering East China University of Science and TechnologyShanghaiChina Department of Biology The Johns Hopkins UniversityBaltimoreMD 21218USA Lexington High School BostonMA 02115USA

Tuberculosis drug resistance continues to threaten global health but the underline molecular mechanisms are not ***(EMB),one of the well-known first-line drugs in tuberculosis treatment is,unfortunately,not free from drug resistance *** studies have shown that some genetic mutations in Mycobacterium tuberculosis(Mtb)EmbR,and EmbC/A/B genes cause EMB ***-PknH pair controls embC/A/B operon,which encodes EmbC/A/B genes,and EMB interacts with EmbA/B ***,the EmbR binding site on PknH was *** conducted molecular simulation on the EmbR-peptides binding structures and discovered phosphorylated PknH 273-280(n′-HEALS^(P)DPD-C′)makesβstrand with the EmbR FHA domain,asβ-MoRF(MoRF;molecular recognition feature)does at its binding *** bond number analysis also supported the peptides’β-MoRF forming activity at the EmbR FHA ***,we discovered that previously known phosphorylation residues might have their chronological order according to the phosphorylation *** discovery validated that Mtb PknH 273-280(n′-HEALSDPD-C′)has reliable EmbR binding *** approach is revolutionary in the computer-aided drug discovery field,because it is the first trial to discover the protein-protein interaction site,and find binding partner in nature from this site.

关键词： Disorder-to-order transition Protein intrinsic disorder Binding site prediction Drug resistance Molecular simulation

A gap-free and haplotype-resolved lemon genome provides insights into flavor synthesis and huanglongbing (HLB) tolerance

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Horticulture Research 2023年第4期10卷 13-22页

作者： Yixue Bao Ziyan Zeng Wei Yao Xiao Chen Mengwei Jiang Akbar Sehrish Bo Wu Charles A.powell Baoshan Chen Jianlong Xu Xingtan Zhang Muqing Zhang State Key Laboratory for Conservation and Utilization of Subtropical Agric-Biological Resources Guangxi UniversityNanning 530005China Hainan Yazhou Bay Seed Laboratory National Nanfan Research Institute(Sanya)Chinese Academy of Agricultural SciencesSanya 572024China/Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijing 100081China Shenzhen Branch Guangdong Laboratory for Lingnan Modern AgricultureGenome Analysis Laboratory of the Ministry of AgricultureAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhen 518120China School of Computing Clemson University821 McMillan RdClemsonSC 29631USA IRREC-IFAS University of FloridaFort PierceFL 34945USA

The lemon(Citrus limon;family Rutaceae)is one of the most important and popular fruits *** also tolerates huan-glongbing(HLB)disease,which is a devastating citrus *** we produced a gap-free and haplotype-resolved chromosome-scale genome assembly of the lemon by combining Pacific Biosciences circular consensus sequencing,Oxford nanopore 50-kb ultra-long,and high-throughput chromatin conformation capture *** assembly contained nine-pair chromosomes with a contig n50 of 35.6 Mb and zero gaps,while a total of 633.0 Mb genomic sequences were *** origination analysis identified 338.5Mb genomic sequences originating from citron(53.5%),147.4Mb frommandarin(23.3%),and 147.1Mb frompummelo(23.2%).The genome included 30528 protein-coding genes,and most of the assembled sequences were found to be repetitive *** significantly expanded gene families were associated with plant-pathogen interactions,plant hormone signal transduction,and the biosynthesis of major active components,such as terpenoids and f lavor *** HLB-tolerant genes were expanded in the lemon genome,such as 2-oxoglutarate(2OG)/Fe(II)-dependent oxygenase and constitutive disease resistance 1,cell wall-related genes,and lignin synthesis *** transcriptomic analysis showed that phloem regeneration and lower levels of phloem plugging are the elements that contribute to HLB tolerance in *** results provide insight into lemon genome evolution,active component biosynthesis,and genes associated with HLB tolerance.

关键词： synthesis insight resolved

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第三讲牙周外科手术

口腔医学纵横 1988年第1期 54-55页

作者： R.n.powell 韩乃明

牙周治疗的目的主要为:消除探诊出血和致病性微生物。实现这两个目的的牙周治疗方法很多,牙周外科手术即是其中之一。我将讲述与此有关的问题。但是,首先我要强调的是:①消除牙周袋不是牙周治疗的目的②牙周手术不是治疗牙周病的常规方... 详细信息

牙周治疗的目的主要为:消除探诊出血和致病性微生物。实现这两个目的的牙周治疗方法很多,牙周外科手术即是其中之一。我将讲述与此有关的问题。但是,首先我要强调的是:①消除牙周袋不是牙周治疗的目的②牙周手术不是治疗牙周病的常规方法。在大多数病例,外科手术并非是必须的。一、牙周手术与预后我曾讲过Hirschefeld等的研究。该研究证明:牙周治疗效果的维持主要与牙周活动性破坏是否发生有关。但遗憾的是,这一研究未详细说明给予了何种治疗方法,及其对预后的影响。Mac Fall在1982年发表了另一个研究报告。研究除了包括Hirschefeld研究的项目外,还详细记录了治疗类型。该研究观察了100个病人,时间10年,结果见表1.根据治疗类型,MacFall又将病人分成

关键词：牙周探诊出血致病性牙周袋骨丧失修复体牙周手术牙周治疗根面平整外科手术