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High power generation of adaptive laser beams in a Nd：YVO4 MOPA system

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Chinese Optics Letters 2017年第12期15卷 24-28页

作者： S. H. Noh d. J. Kim J. W. Kim department of Photonics and Nanoelectronics Hanyang University ERICA Ansan 15588 South Korea

We report efficient power scaling of the laser output with an adaptive bemn profile from an Nd：YAG dual-cavity master oscillator using a three-stage end-pumped Nd：YVO4 amplifier. We succeed ill the last switching of an excited laser mode by modulating an acousto-optic modulator loss in a dual-cavity master oscillator, thereby achieving temporal modulation of the output beam profile. The outputs from the master oscillator are amplified via a three-stage power amplifier yielding 36.6, 40.5, and 45.4 W of the maximum output at 116.8 W of incident pump power for the transverse electromagnetic, Laguerre-Gaussian, and quasi-top-hat beam, respectively. The prospects for further power scaling and applications via the dual-cavity master-oscillator power-amplifier （MOPA） system are considered.

关键词： High power generation of adaptive laser beams in a Nd:YVO4 MOPA system Nd

Application of grouped detrital zircon analyses to determine provenance and closely approximate true depositional age:Early Cretaceous McMurray-Clearwater succession,Canada

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Geoscience Frontiers 2021年第2期12卷 877-892页

作者： L.Rinke-Hardekopf S.E.dashtgard C.Huang H.d.Gibson Applied Research in Ichnology and Sedimentology(ARISE)Group Dept.of Earth SciencesSimon Fraser University8888 University DriveBurnabyBC V5A 1S6Canada

In the Lower CretaceousMcMurray-Clearwater succession of the intracontinental Alberta Foreland Basin,Canada,detrital zircon U-Pb geochronology samples(referred to herein as dZ samples)have been used to interpret the strata as representing a paleo-continental-scale drainage ***,the majority of dZ samples are relatively small(n≈90–100),and syndepositional dZ(i.e.,crystallization ageder than depositional age)are *** has forced a reliance on dinocysts with long stratigraphic ranges to chronostratigraphically subdivide the McMurray-Clearwater succession rather than employing maximum depositional ages(MdAs)derived from dZ ***,43 dZ samples(taken from20 subsurface cores)are assigned to 1 of 5 stratigraphic intervals,and in each stratigraphic interval all associated dZ samples are combined to produce a grouped dZ *** and comparison of individual and grouped dZ samples are used to(1)assess variability in provenance through time and space,and(2)assess the accuracy of chronostratigraphically subdividing the succession using *** the main paleo-drainage axis,a comparison of dissimilarity between dZ samples from the same stratigraphic interval,as well as between stratigraphic intervals,reveals increasing average dissimilarity between individual dZ samples and their respective grouped dZ samplewith increasing spatial separation of *** data indicate that in the McMurray depocenter some sediment is sourced from local tributaries,leading to geographical provenance *** for all 43 dZ samples and groupedMdAs(gMdAs)for the 5 grouped dZ samples are compared to an ash-derived absolute age and existing *** theMcMurray Formation,comparison of MdAs to gMdAs shows that in basins with rare syndepositional dZ,the gMdA method improved depositional age estimates by transforming low-confidence MdAs(e.g.,youngest single grains)into high-confidence(multi-grain)*** the Clearwater Formationwhere

关键词： detrital zircon Maximum depositional age Provenance variability Intracontinental foreland basin McMurray-Clearwater succession

In vitro and in vivo application of RNA interference for targeting genes involved in peritrophic matrix synthesis in a lepidopteran system

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Insect Science 2013年第1期20卷 92-100页

作者： Umut Toprak doug Baldwin Martin Erlandson Cedric Gillott Stephanie Harris dwayne d. Hegedus Agriculture and Agri-Food Canada Ottawa Ontario Canada department of Biology University of Saskatchewan Canada department of Plant Protection Faculty of Agriculture University of Ankara Turkey department of Food and Bioproduct Sciences University of Saskatchewan Saskatoon SK Canada

The midgut of most insects is lined with a semipermeable acellular tube, the peritrophic matrix （PM）, composed of chitin and proteins. Although various genes encoding PM proteins have been characterized, our understanding of their roles in PM structure and function is very limited. One promising approach for obtaining functional information is RNA interference, which has been used to reduce the levels of specific mRNAs using double-stranded RNAs administered to larvae by either injection or feeding. Although this method is well documented in dipterans and coleopterans, reports of its success in lepidopterans are varied. In the current study, the silencing midgut genes encoding PM proteins （insect intestinal mucin 1, insect intestinal mucin 4, PM protein 1） and the chitin biosynthetic or modifying enzymes （chitin synthase-B and chitin deacetylase 1） in a noctuid lepidopteran, Mamestra configurata, was examined in vitro and in vivo. In vitro studies in primary midgut epithelial cell preparations revealed an acute and rapid silencing （by 24 h） for the gene encoding chitin deacetylase 1 and a slower rate of silencing （by 72 h） for the gene encoding PM protein 1. Genes encoding insect intestinal mucins were slightly silenced by 72 h, whereas no silencing was detected for the gene encoding chitin synthase-B. In vivo experiments focused on chitin deacetylase 1, as the gene was silenced to the greatest extent in vitro. Continuous feeding of neonates and fourth instar larvae with double-stranded RNA resulted in silencing of chitin deacetylase 1 by 24 and 36 h, respectively. Feeding a single dose to neonates also resulted in silencing by 24 h. The current study demonstrates that genes encoding PM proteins can be silenced and outlines conditions for RNA interference by per os feeding in lepidopterans.

关键词： chitin deacetylase chitin synthase-B lepidoptera peritrophic matrix,peritrophin RNA interference

Suicide transport blockade of motor neuron survival generates a focal graded injury and functional deficit

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作者： edited by d&Ad.

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Neural Regeneration Research 2021年第7期16卷 1281-1287页

作者： Allison S.Liang Joanna E.Pagano Christopher A.Chrzan Randall d.McKinnon department of Neurosurgery Rutgers-Robert Wood Johnson Medical SchoolPiscatawayNJUSA Member The Cancer Institute of New JerseyNew BrunswickNJUSA

We describe a pre-clinical spinal cord motor neuron injury model that is minimal invasive, reproducible, focal and easily applied to small *** axonal transport of a pro-apoptotic phosphatidylinosotol 3'-kinase inhibitor, wortmannin, via the sciatic nerve results in loss of ipsilateral lumbar motor neurons proportional to the level of drug *** neuron loss was detected by choline acetyltransferase(ChAT) immunostaining and with a transgenic thy1-eGFP *** short half-life of wortmannin generates minimal wound spread, and wortmannin does not affect axon transport, as determined by co-injection of a pseudorabies virus *** quantitative transcript analysis, we found that ChAT transcripts significantly decreased at 14 days post-delivery of 1 μg wortmannin, relative to sham controls, and remained low after 90 *** effects were observed with 200 ng and 100 ng *** also generated a transient and significant increase in astrocyte Gfap transcripts after 14 days with a return to control levels at 90 *** mice had hind limb spasticity and a forced motor function defect that was quantified using a water exit *** rapidly exit a shallow water tray, and wortmannin treated animals were up to 12-fold slower, a phenotype that persisted for at least 3 *** the focal delivery of wortmannin to motor neurons generates a reproducible and scalable injury that can facilitate quantitative studies on neural regeneration and *** efficacy of sciatic nerve suicide transport can also explain neurotoxin-mediated selective loss of motor neurons in diseases such as amyotrophic lateral *** procedures were performed at Rutgers under established Institutional Animal Care and Use protocols(eIACUC_TR201800022, approved on March 20, 2018).

关键词： amyotrophic lateral sclerosis injury motor function motor neuron PI3'kinase sciatic nerve suicide transport wortmannin

A unique binding pocket induced by a noncanonical SAH mimic to develop potent and selective PRMT inhibitors

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Acta Pharmaceutica Sinica B 2023年第12期13卷 4893-4905页

作者： Youchao deng Xiaosheng Song Iredia d.Iyamu Aiping dong Jinrong Min Rong Huang department of Medicinal Chemistry and Molecular Pharmacology Center for Cancer ResearchInstitute for Drug DiscoveryPurdue UniversityWest LafayetteIN 47907USA Structural Genomics Consortium and department of Physiology University of TorontoTorontoOntario M5G 1L7Canada Hubei Key Laboratory of Genetic Regulation and Integrative Biology School of Life SciencesCentral China Normal UniversityWuhan 430079China Xiangya School of Pharmaceutical Sciences Central South UniversityChangsha 410013China

Protein arginine methyltransferases(PRMTs)are attractive targets for developing therapeutic agents,but selective PRMT inhibitors targeting the cofactor SAM binding site are ***,we report the discovery of a noncanonical but less polar SAH surrogate Yd1113 by replacing the benzyl guanidine of a pan-PRMT inhibitor with a benzyl urea,potently and selectively inhibiting PRMT3/4/***,crystal structures reveal that the benzyl urea moiety of Yd1113 induces a unique and novel hydrophobic binding pocket in PRMT3/4,providing a structural basis for the *** addition,Yd1113 can be modified by introducing a substrate mimic to form a“T-shaped”bisubstrate analogue Yd1290 to engage both the SAM and substrate binding pockets,exhibiting potent and selective inhibition to typeⅠPRMTs(IC_(50)demonstrated the promise of Yd1113 as a general SAH mimic to build potent and selective PRMT inhibitors.

关键词： PRMTs Structure based inhibitor design Benzyl urea Noncanonical SAH mimic Homocysteine binding pocket Crystal structure

Ir-Catalyzed Asymmetric Hydrogenation of α-Alkylidene β-Lactams and Cyclobutanones

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Chinese Journal of Chemistry 2018年第7期36卷 612-618页

作者： Jingzhao Xia Yu Nie Guoqiang Yang Yangang Liu Ilya d. Gridnev Wanbin Zhang Shanghai Key Laboratory for Molecular Engineering of Chiral drugs School of Pharmacy Shanghai Jiao Tong University 800 Dongchuan Road Shanghai 200240 China School of Chemistry and Chemical Engineering Shanghai Jiao Tong University 800 Dongchuan Road Shanghai 200240 China department of Chemistry Graduate School of Science Tohoku University Aramaki 3-6 Aoba-ku Sendai 9808578 Japan

Chiral β-Iactams and cyclobutanones are present in numerous natural and pharmaceutical products. The stereoselective construction of chiral four-membered cyclic compounds is an ongoing challenge for the chemical community. Herein, we report a highly stereocontrolled construction of four-membered ring （mini-sized） β-lactams and cyclobutanones via an Ir/In-BiphPHOX-catalyzed asymmetric hydrogenation, providing the corresponding optically active four-membered ring carbonyl products bearing an α-chiral carbon center with excellent yields （up to 99%） and enantioselectivities （up to 98%） under mild reaction conditions （1.0-2.5 bar H2 for 1.0-10 h）. The reaction presents wide substrate scope. diverse transformations of the catalyzed products were also conducted to show the potential utility of this protocol.

关键词： β-lactam cyclobutanone iridium phosphine-oxazoline ligand asymmetric hydrogenation

Investigations on the Corrosion Behaviour and Structural Characteristics of Low Temperature Nitrided and Carburised Austenitic Stainless Steel

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材料热处理学报 2004年第5期25卷 311-315页

作者： d. Mnter H.-J. Spies H. Biermann Chr. Eckstein department of Materials Engineering Technische Universitat Bergakademie Freiberg 09599 Freiberg/ GermanyDepartment of Materials Engineering Technische Universitat Bergakademie Freiberg 09599 Freiberg/ GermanyDepartment of Materials Engineering Technische Universitat Bergakademie Freiberg 09599 Freiberg/ GermanyCorrosion laboratory Steel-Centre-Freiberg (SZF) Research centre of the Technische Universitat Bergakademie Freiberg 09599 Freiberg/ Germany

The wear resistance of austenitic stainless steels can be improved by thermo-chemical surface treatment with nitrogen and carbon. However, it is possible that the corrosion resistance will be impaired by the precipitation of chromiumnitrid or -carbide. The present contribution deals with investigations of the corrosion behaviour and structural characteristics of a low temperature nitrided and carburised austenitic stainless steel. The material investigated was AISI 316L (X2CrNiMol7-12-2) austenitic stainless steel. A commercial plasma-nitriding unit (pulsed dc) was used for the nitriding and carburising process. Additional samples were treated by the gasoxinitriding process for a comparison between plasma- and gasoxinitriding. The nitrided and carburised layer of austenitic stainless steel consists of the nitrogen or carbon S-phase (expanded austenite), respectively. X-ray diffraction investigations show the typical shift of the peaks to lower angles, indicating expansion of the fee lattice. Also the X-ray diffraction technique was employed to study the residual stresses in the nitrogen and carbon S-phase. The corrosion behaviour of surface engineered samples was investigated with electrochemical methods. Anodic potentiodynamic polarisation curves were recorded for testing the resistance against general corrosion (in H2SO4) and pitting corrosion (in NaCl).

关键词：奥氏体不锈钢腐蚀低温渗氮低温渗碳残留应力

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巨头企业股价下跌硅谷阴影挥之不去

商业周刊（中文版） 2018年第24期 24-25页

作者： sarah Ponczek Jeran Wittenstein 杨熙(译) 不详

史蒂夫·霍夫曼(Steve Hoffman)拿起话筒,散发出硅谷乐观主义的光芒。他身穿标志性蓝紫格子衬衫,高亢的声音在水泥墙房间内回荡。他对自己的创业孵化器成就十分自得,飞快报出一连串他帮助推进的公司名字:Instagram、Etsy、***、Foursqu... 详细信息

史蒂夫·霍夫曼(Steve Hoffman)拿起话筒,散发出硅谷乐观主义的光芒。他身穿标志性蓝紫格子衬衫,高亢的声音在水泥墙房间内回荡。他对自己的创业孵化器成就十分自得,飞快报出一连串他帮助推进的公司名字:Instagram、Etsy、***、Foursquare。

关键词：硅谷阴影股价企业创业孵化器乐观主义霍夫曼标志性