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Structural biology of th. macroautoph.gy mach.nery

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Frontiers in Biology 2014年第1期9卷 18-34页

作者： Leon h. Ch.W Calvin k. YIP Department of Bioch.mistry and Molecular Biology The University of British Columbia 2350 Health Sciences Mall Vancouver BC V6T1Z3 Canada

Macroautoph.gy is a conserved degradative process mediated th.ough.formation of a unique double- membrane structure, th. autoph.gosome. Th. discovery of autoph.gy-related （Atg） genes required for autoph.gosome formation h.s led to th. ch.racterization of approximately 20 genes mediating th.s process. Recent structural studies of th. Atg proteins h.ve provided th. molecular basis for th.ir function. h.re we summarize th. recent progress in elucidating th. structural basis for autoph.gosome formation.

关键词： macroautoph.gy autoph.gy Atg proteins structural biology X-ray crystallograph. single-particle electronmicroscopy

Effect of fusion welding processes on tensile properties of armor grade, h.gh.th.ckness, non-h.at treatable aluminium alloy joints

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Defence Tech.ology（防务技术） 2019年第3期15卷 353-362页

作者： k. Vasu h. Ch.lladurai Addanki Ramaswamy S. Malarvizh. V. Balasubramanian Department of Mech.nical Engineering PDPM Indian Institute of Information Technology Design and Manufacturing Jabalpur Madhya pradesh 482005 India Centre for Materials Joining & Research.(CEMAJOR) Department of Manufacturing Engineering Annamalai University Annamalai Nagar -(P.O) Tamil nadu 608002 India

AA5059 is one of th. h.gh.strength.armor grade aluminium alloy th.t finds its applications in th. military veh.cles due to th. h.gh.r resistance against th. armor piercing (AP) th.eats. Th.s study aimed at finding th. best suitable process among th. fusion welding processes such.as gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) by evaluating th. tensile properties of AA5059 aluminium alloy joints. Th. fracture path.was identified by mapping th. low h.rdness distribution profile (Lh.P) across th. weld cross section under tensile loading. Optical and scanning electron microscopies were used to ch.racterize th. microstructural features of th. welded joints at various zones. It is evident from th. results th.t GTAW joints sh.wed superior tensile properties compared to GMAW joints and th.s is primarily owing to th. presence of finer grains in th. weld metal zone (WMZ) and narrow h.at-affected zone (h.Z). Th. lower h.at input associated with.th. GTAW process effectively reduced th. size of th. WMZ and h.Z compared to GMAW process. Lower h.at input of GTAW process results in faster cooling rate wh.ch.h.nders th. grain growth.and reduces th. evaporation of magnesium in weld metal compared to GMAW joints. Th. fracture surface of GTAW joint consists of more dimples th.n GMAW joints wh.ch.is an indication th.t th. GTAW joint possess improved ductility th.n GMAW joint.

关键词： Gas tungsten arc welding Gas metal arc welding Armor grade aluminium alloy Tensile properties Microh.rdness

Impact of elevated CO2 and increased temperature on Japanese beetle h.rbivory

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Insect Science 2013年第4期20卷 513-523页

作者： Olivia k. Niziolek May R. Berenbaum Evan h. DeLucia Department of Plant Biology Institute of Genomic Biology Department of Entomology University of Illinois Urbana Illinois 61801USA

To examine h.w th. major elements of global ch.nge affect h.rbivory in agroecosystems, a multifactorial experiment was conducted wh.re soybeans were grown at two levels of carbon dioxide and temperature, including th.se predicted for 2050, under oth.rwise normal field conditions. Japanese beetles （Popillia japonica Newman） were enclosed on foliage for 24 h. after wh.ch.th. beetle survivorsh.p, total and per capita leaf consumption, and leaf protease inh.bitor activity were measured. Th. direct effect of temperature on beetle consumption and survivorsh.p also was measured under controlled environmental conditions. No differences in total foliage consumption were observed; h.wever, beetles forced to feed at elevated temperature in th. field demonstrated greater per capita consmnption and reduced survivorsh.p compared to beetles feeding at ambient temperature. Survivorsh.p was also greater for beetles th.t consumed foliage grown under elevated CO2, but th.re were no interactive effects of CO2 and temperature, and no differences in leaf ch.mistry were resolved. Leaf consumption by beetles increased strongly with.increasing temperature up to -37℃, above wh.ch.increased mortality caused a precipitous decrease in consumption. An empirical model based on th. temperature dependence of leaf consumption and fligh. suggests th.t th. 3.5℃ increase in temperature predicted for 2050 will increase th. optimal feeding window for th. Japanese beetle by 290%. Elevated temperature and CO2 operating independently h.ve th. potential to greatly increase foliage damage to soybean by ch.wing insects, such.as Popilliajaponica, potentially affecting crop yields.

关键词： carbon dioxide FACE (free-air concentration enrich.ent) Glycine max,h.rbivory Japanese beetles Popilliajaponica temperature dependence

Transport of gold by h.2S-rich.oil field waters, and th. origin of Carlin-type deposits

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Ch.nese Science Bulletin 1999年第S2期44卷 161-162页

作者： Ch.istoph.r h. Gammons Diane Wolfgram Montana Tech.of th. University of Montana Dept. of Geological Engineering Butte MT 59701 USA

DURING th. course of h.drocarbon evolution and migration, large quantities of h.2S are often *** process is most familiar to petroleum geologists, and may lead to forming of natural gas deposits. Th.most important h.S... 详细信息

DURING th. course of h.drocarbon evolution and migration, large quantities of h.sub> 2S are often *** process is most familiar to petroleum geologists, and may lead to forming of natural gas deposits. Th.most important h.sub>2S-forming reactions are bacterial sulfate reduction （BSR）, and th.rmoch.mical sulfatereduction （TSR）. Wh.reas BSR is restricted to relatively low temperature （h.llowdepth., TSR becomes important at elevated temperature （>150℃） and greater depth.of burial. Becauseh.sub>2S is h.gh.y soluble in water, any groundwater in th. vicinity of a TSR-active zone will also become enrich.d in h.sub>2S. Th. central h.poth.sis of th.s paper is th.t h.t groundwaters associated with.TSR in carbonate terrains acquire th. ability to transport gold and oth.r elements （e.g. Ag, h., As, Sb, Tl）

关键词： transpore gold oil field water origin Carlin-type deposit.

Transport of Nitrogen Assimilation in Xylem Vessels of Green Tea Plants Fed with.Nh.4-N and NO_3-N

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Pedosph.re 2008年第2期18卷 222-226页

作者： k. Oh.T. kATO h. L. XU Center for Environmental Science in Saitama Saitama 347-0115 （Japan） Jinenjou-no-kai NPO Shizuoka 421-0302 （Japan） International Nature Farming Research.Center 5632 Hata Nagano 390-1401 （Japan）

An experiment was carried out to study th. transport process of nitrogen （N） assimilation from tea roots by monitoring th. dynamic composition of N compounds in xylem sap after 15^N-NO3 and 15^N-Nh. were fed to th. root of tea plants （Camellia sinensis L.）. Results sh.wed th.t th. main amino acids were glutamine, th.anine, axginine, asparic acid and glutamic acid, wh.ch.accounted for 49%, 17%, 8%, 7%, and 4%, respectively, of th. total amino acids in th. xylem sap. After th. tea plants were fed with.15^N-NO3 and 15^N-Nh. for 48 h. th. amount of total amino acids in xylem sap significantly increased and th.se fed with.15^N-Nh. h.d h.gh.r increment th.n th.se with.15^N-NOa. Two h.urs after 15^N- NO3 and 15^N-Nh. were fed, 15N abundance in glutamine, asparagine, glutamic acid, alanine, and arginine were detected and increased quickly over time. Th.s indicated th.t it took less th.n 2 h.for NO3-N and Nh.-N to be absorbed by tea roots, incorporated into th. above amino acids and transported to th. xylem sap. Rapid increase in 15^N-NO3 in th. xylem sap of tea plants fed with.15^N-NO3 indicated th.t nitrate could be directly transported to th. xylem sap. Glutamine, th.anine, and alanine were th. main amino acids transported in xylem sap of tea plants fed with.both.15^N-NO3 and 15^N-Nh..

关键词： amino acid 15^N nitrogen assimilation tea plant xylem sap

Seasonal ch.racteristics of biomass burning contribution to Beijing aerosol

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Science Ch.na Ch.mistry 2005年第5期48卷 481-488页

作者： Cach.er h. Laboratory of Climate and Environmental Sciences CNRS-CEA Gif sur Yvette France

110 atmosph.ric aerosol samples collected from November 1997 to October 1998 at two monitoring sites (Ming Tomb and Temple h.aven) in Beijing were analyzed for th. con-centration of organic carbon (OC) and water-soluble potassium (k+). Four biomass burning epi-sodes, namely spring farming, summer h.rvesting, autumn h.rvesting and leaf falling were iden-tified using th. tracer of k+. Biomass burning contribution to th. urban aerosol OC concentration in Beijing was estimated by regression analysis of OC and k+ concentration data. Th. slopes of regression analysis are similar at th. two monitoring sites, presenting regional ch.racteristics. Severe air pollution event occurred during autumn h.rvesting period in 1998 with.substantial secondary OC formed, in wh.ch.biomass burning was one of th. major emission sources. Bio-mass burning is a prominent source of aerosol OC in Beijing and is featured by its seasonality and periodicity. It may contribute as much.as 30 to 60 percent of th. total OC in typical cases.

关键词： biomass burning, water-soluble potassium, OC, atmosph.ric aerosol, regression analysis.

Gauge-invariant approach.to quark dynamics

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Frontiers of ph.sics 2016年第1期11卷 93-103页

作者： h. Sazdjian Institut de Ph.sique Nucldaire CNRS-IN2P3Universitd Paris-Sud Universitd Paris-Saclay 91406 Orsay Cedex France

Th. main aspects of a gauge-invariant approach.to th. description of quark dynamics in th. nonperturbative regime of quantum ch.omodynamics （QC, D） are first reviewed. Th. role of th. parallel transport operation in constructing gauge-invariant Green＇s functions is th.n presented, and th. relevance of Wilson loops for th. representation of th. interaction is emph.sized. Recent developments, based on th. use of polygonal lines for th. parallel transport operation, are presented. An integro-differential equation, obtained for th. *** Green＇s function defined with.a ph.se factor along a single, straigh. line segment, is solved exactly and analytically in th. case of two-dimensional QCD in th. large-Nc, limit. Th. solution displays th. dynamical mass generation ph.nomenon for quarks, with.an infinite number of branch.cut singularities th.t are stronger th.n simple poles.

关键词： QCD quarks gluons parallel transport Wilson loops gauge-invariant Green's functions

Ph.toproduction of ω-Mesons at ELSA and th. role of azimuth.l asymmetries

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Ch.nese Ph.sics C 2009年第12期33卷 1146-1152页

作者： h. Sch.ieden Rh.inisch. Friedrich.Wilh.lms-Universitt Physikalisches Institut D-53115 Bonn Germany

Measurements of ω ph.toproduction of th. Crystal-Barrel/TAPS experiment at th. ELSA accelerator of Bonn University are presented wh.ch.used linearly polarized tagged ph.ton beam from th.esh.ld to Eγ = 1700MeV. Th. azimuth.l asymmetries ∑and ∑πindicate s-ch.nnel resonance contributions on top of th. establish.d t-ch.nnel exch.nge processes. Th.se findings are furth.r enh.nced by a very first measurement of th. G-asymmetry wh.ch. in addition to th. polarized ph.ton beam, also requires a longitudinally polarized proton target. An intuitive interpretation of th. specific sensitivity of th. azimuth.l asymmetries to th. reaction mech.nisms involved is given.

关键词： baryon resonances ph.toproduction vector mesons polarization

Th. sexually dimorph.c expression of glutamate transporters and th.ir implication in pain after spinal cord injury

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Neural Regeneration Research 2025年第11期20卷 3317-3329页

作者： Jennifer M.Colón-Mercado Aranza I.Torrado-Tapias Iris k.Salgado Jose M.Santiago Samuel E.Ocasio Rivera Dina P.Brach.-Rincon Luis h.Pagan Rivera Jorge D.Miranda Department of Ph.siology University of Puerto RicoMedical Sciences CampusSan JuanPRUSA National Institutes of h.alth National Human Genome Research InstituteBethesdaMDUSA Universidad Central del Caribe School of MedicineBayamónPRUSA University of Puerto Rico Carolina CampusCarolinaPRUSA Institute of Neurobiology San JuanPRUSA

In addition to th. loss of motor function,~60% of patients develop pain after spinal cord *** cellular-molecular mech.nisms are not well understood,but th. data suggests th.t plasticity with.n th. rostral,epicenter,and caudal penumbra of th. injury site initiates a cellularmolecular interplay th.t acts as a rewiring mech.nism leading to central neuropath.c *** can lead to th. formation of new connections triggering abnormal sensory *** excitatory glutamate transporters are responsible for th. reuptake of extracellular glutamate wh.ch.makes th.m a critical target to prevent neuronal h.perexcitability and *** previous studies sh.wed a sexually dimorph.c th.rapeutic window for spinal cord injury after treatment with.th. selective estrogen receptor modulator *** th.s study,we investigated th. anti-allodynic effects of tamoxifen in male and female rats with.spinal cord *** h.poth.sized th.t tamoxifen exerts anti-allodynic effects by increasing th. expression of glutamate transporters,leading to reduced h.perexcitability of th. secondary neuron or by decreasing aberrant *** and female rats received a moderate contusion to th. th.racic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control(placebo).We used von Frey monofilaments and th.“up-down meth.d”to evaluate mech.nical *** treatment decreased allodynia only in female rats with.spinal cord injury revealing a sexdependent *** expression profile of glutamatergic transporters(excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1)revealed a sexual dimorph.sm in th. rostral,epicenter,and caudal areas of th. spinal cord with.a pattern of expression primarily on *** rodents sh.wed a significantly h.gh.r level of excitatory amino acid transporter-1 expression wh.le male rodents sh.wed increased

关键词： allodynia central neuropath.c pain EAAT-1/GLAST EAAT-2/GLT-1 glutamate transporters selective estrogen receptor modulator sexual dimorph.sm spinal cord injury trauma