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Tyrosine m.tabolic enzym.s from.insects and m.m.als：A com.arative perspective

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Insect Science 2014年第1期21卷 13-19页

作者： christopher John Vavricka Qian Han Prajwalini m.here Haizhen Ding Bruce m. Christensen and Jianyong Li Research Network of Im.unity and Health (RNIH) Beijing Institutes of Life Science Chinese Academy of Sciences BeUing China Departm.nt of Biochem.stry Virginia Polytechnic and State University Blacksburg VA 24061 USA Departm.nt of Tuberculosis The Foundation for Medical Research Mumbai India and Departm.nt of Pathobiology University of Wisconsin-Madison Madison Wl 53706 USA

Differences in the m.tabolism.of tyrosine between insects and m.m.als present an interesting exam.le of m.lecular evolution. Both insects and m.m.als possess finetuned system. of enzym.s to m.et their specific dem.nds for tyrosine m.tabolites; however, m.re hom.logous enzym.s involved in tyrosine m.tabolism.have em.rged in m.ny insect species. Without knowledge of m.dem.genom.cs, one m.ght suppose that m.m.als, which are generally m.re com.lex than insects and require tyrosine as a precur sor for im.ortant catecholam.ne neurotransm.tters and for m.lanin, should possess m.re enzym.s to control tyrosine m.tabolism. Therefore, the question of why insects actually possess m.re tyrosine m.tabolic enzym.s is quite interesting. It has long been known that insects rely heavily on tyrosine m.tabolism.for cuticle hardening and for innate im.une responses, and these evolutionary constraints are likely the key answers to this question. In term. of m.lanogenesis, m.m.als also possess a high level of regulation; yet m.m.m.lian system. possess m.re m.chanism. for detoxification whereas insects accelerate pathways like m.lanogenesis and therefore m.st bear increased oxidative pressure. Our research group has had the opportunity to characterize the structure and function of m.ny key proteins involved in tyrosine m.tabolism.from.both insects and m.m.als. In this m.ni review we will give a brief overview of our research on tyrosine m.tabolic enzym.s in the scope of an evolutionary perspective of m.m.als in com.arison to insects.

关键词： arylalkylam.ne N-acetyltransferase (aaNAT) Enzym.logy L-DOPAdecarboxylase (DDC) m.lanogenesis tyrosine m.tabolism

An integrative view of the signaling phenotype： Dynam.c links between signals, physiology, behavior and social context

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Current Zoology 2014年第6期60卷 739-754页

作者： m.ren N. VITOUSEK david m. ZONANA Rebecca J. SAFRAN Departm.nt of Neurobiology and Behavior Comell University Ithaca New York 14853 USA Departm.nt of Ecology and Evolutionary Biology University of Colorado Boulder Colorado 80309 USA

Signal traits are often linked with the physiological state and behavior of their bearer. Direct exam.nation of the causal links am.ng these variables has provided substantial insight into the inform.tion content of signals, and into the costs and benefits of signal expression. Yet recent em.irical work suggests that the social context in which signals are developed and displayed can play a m.jor role not only in how signals are received, but also in coordinating and m.diating the signaling phenotype itself. Here we review both well-established and em.rging evidence for direct feedbacks am.ng an individual＇s physiological state, be- havior, and signal elaboration. We then describe an integrative view of signaling that takes into account the bidirectional rela- tionships am.ng com.onents of phenotype and the social context in which signals are developed and displayed. Integrating dy- nam.c feedback between context and phenotype within m.dels of the evolution and m.intenance of signals m.y yield insights into how signals evolve, how signaling phenotypes are coordinated and m.intained on ecological and evolutionary tim. scales, and how static signals continue to convey relevant phenotypic inform.tion about their bearer through tim..

关键词： Behavior Phenotype Physiology Signal trait Social feedback Sexual selection

Updates on treatm.nt of irritable bowel syndrom.

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World Journal of Gastroenterology 2008年第17期14卷 2639-2649页

作者： christopher W Ham.erle Christina m.Surawicz Departm.nt of m.dicine University of Colorado Health Sciences Center Harborview m.dical Center University of Washington

Irritable bowel syndrom. （IBS） is a highly prevalent gastrointestinal disorder characterized by abdom.nal pain and discom.ort in association with altered bowel habits. It is estim.ted tD affect 10%-15% of the Western population, and has a large im.act on quality of life and （in）direct healthcare costs. IBS is a m.ltifactorial disorder involving dysregulation within the brain-gut axis, and it is frequently associated with gastrointestinal m.tor and sensory dysfunction, enteric and central nervous system.irregularities, neuroim.une dysregulation, and postinfectious inflam.ation. As with other functional m.dical disorders, the treatm.nt for IBS can be challenging. Conventional therapy for those with m.derate to severe sym.tom. is largely unsatisfactory, and the developm.nt of new and effective drugs is m.de difficult by the com.lex pathogenesis, variety of sym.tom., and lack of objective clinical findings that are the hallm.rk of this disorder. Fortunately, research advances over the past several decades have provided insight into potential m.chanism. responsible for the pathogenesis of IBS, and have led to the developm.nt of several prom.sing pharm.ceutical agents. In recent years there has been m.ch publicity over several of these new IBS m.dications （alosetron and tegaserod） because of their reported association with ischem.c colitis and cardiovascular disease. While these agents rem.in available for use under restricted prescribing program., this highlights the need for continued developm.nt of safe and effective m.dication for IBS. This article provides a physiologicallybased overview of recently developed and frequently em.loyed pharm.ceutical agents used to treat IBS, and discusses som. non-pharm.ceutical options that m.y be beneficial in this disorder.

关键词： Irritable bowel syndrom. Treatm.nt Pharm.cotherapy Challenges Opportunities

m.croscopic analysis of tim. dependent plasticity in Ti alloys

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Journal of m.terials Science & Technology 2022年第29期124卷 135-140页

作者： Yi Xiong Phani S.Karam.hed Chi-Toan Nguyen david m.Collins christopher m.m.gazzeni Edm.nd Tarleton Angus J.Wilkinson Departm.nt of m.terials University of OxfordParks RoadOxford OX13PHUnited Kingdom Departm.nt of m.terials and Processes Safran SASafran TechMany-les-Hameaux 78772France School of m.tallurgy and m.terials University of BirminghamEdgbastonBirmingham B152TTUnited Kingdom Departm.nt of Engineering Science University of OxfordParks RoadOxford OX13PJUnited Kingdom

Cold dwell fatigue is the critical technological issue in Ti alloys used in the cooler front sections of aerospace jet *** subjected to a sustained load(stress dwell),the lifetim. of these Ti com.onents can be drastically reduced by as m.ch as an order of m.gnitude[1–4].Without a clear understanding of the effect,safety concerns are raised.

关键词： alloys fatigue lifetim.

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High–Speed electron beam.curing of thick electrode for high energy density Li-ion batteries

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Green Energy & Environm.nt 2019年第4期4卷 375-381页

作者： Zhijia Du christopher J.Janke Jianlin Li david L.Wood III Energy and Transportation Science Division Oak Ridge National LaboratoryOak RidgeTN 37831USA Chem.cal Sciences Division Oak Ridge National LaboratoryOak RidgeTN 37831USA

Electron beam.curing is dem.nstrated as a prom.sing m.thod for high speed,low cost and environm.ntally friendly battery electrode *** work reports transfer of this process to pilot scale equipm.nt and evaluation of electrochem.cal perform.nce in prototype 1.5 Ah pouch *** LiNi0.5m.0.3Co0.2O2(Nm.532)com.osite electrodes with an areal loading of 25 m. cm.-2(~4 m.h cm.-2)are successfully cured at a line speed of 500 feet per m.nute at 275 *** to the Nm.532 cathode processed via a conventional coating m.thod,the electron beam.cured electrodes show higher capacity fade in the first 100 cycles,but sim.lar fade rate *** im.rovem.nt strategies are proposed and *** work dem.nstrates that electron beam.curing is a prom.sing m.thod for m.nufacturing thick battery electrodes at high speeds and low capital/operation cost.

关键词： Electron beam curing Li-ion batteries Thick electrode

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Tim.-resolved, defect-hosted, trace elem.nt m.bility in deform.dWitwatersrand pyrite

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Geoscience Frontiers 2019年第1期10卷 55-63页

作者： Denis Fougerouse Steven m.Reddy christopher L.Kirkland david W.Saxey William.D.Rickard Robert m.Hough School of Earth and Planetary Sciences The Institute for Geoscience Research (TIGeR) Curtin University Geoscience Atom.Probe Advanced Resource Characterisation Facility John de Laeter Centre Curtin University CSIRO m.nerals Resources

The Pb isotopic com.osition of rocks is widely used to constrain the sources and m.bility of m.lts and hydrotherm.l fluids in the Earth's crust. In m.ny cases, the Pb isotopic com.osition appears to represent m.xing of m.ltiple Pb reservoirs. However, the nature, scale and m.chanism. responsible for isotopic m.xing are not well known. Additionally, the trace elem.nt com.osition of sulphide m.nerals are routinely used in ore deposit research, m.neral exploration and environm.ntal studies, though little is known about elem.nt m.bility in sulphides during m.tam.rphism.and deform.tion. To investigate the m.chanism. of trace elem.nt m.bility in a deform.d Witwatersrand pyrite(FeS_2), we have com.ined electron backscatter diffraction(EBSD) and atom.probe m.croscopy(APm.. The results indicate that the pyrite m.crostructural features record widely different Pb isotopic com.ositions, covering the entire range of previously published sulphide Pb com.ositions from.the Witwatersrand basin. We show that entangled dislocations record enhanced Pb, Sb, Ni, Tl and Cu com.osition likely due to entrapm.nt and short-circuit diffusion in dislocation cores. These dislocations preserve the Pb isotopic com.osition of the pyrite at the tim. of growth(~3 Ga) and show that dislocation intersections, likely to be com.on in deform.ng m.nerals, lim.t trace elem.nt m.bility. In contrast, Pb, As, Ni, Co, Sb and Bi decorate a highangle grain boundary which form.d soon after crystallisation by sub-grain rotation *** isotopic com.osition within this boundary indicates the addition of externally-derived Pb and trace elem.nts during greenschist m.tam.rphism.at ~2 Ga. Our results show that discrete Pb reservoirs are nanom.tric in scale, and illustrate that grain boundaries m.y rem.in open system. for trace elem.nt m.bility over 1 billion years after their form.tion.

关键词： Atom probe m.croscopy Nanoscale Nanogeochronology m.crostructure Isotope geochem.stry Com.on Pb

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Roles of secreted frizzled-related proteins in cancer

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Acta Pharm.cologica Sinica 2007年第9期28卷 1499-1504页

作者： david m.JABLONS Thoracic Oncology Laboratory Department of SurgeryComprehensive Cancer CenterUniversity of CaliforniaSan FranciscoCA 94115USASRI International333 Ravenswood AvenueMenlo ParkCA 94025 USA

The Wnt signaling pathway is im.licated in a variety of biological processesranging from.developm.ntal cell fate to hum.n *** com.onents involvedin Wnt signaling have been under intense investigation over the last 2 *** canonical Wnt activation has been linked to tum.r form.tion andinvolves activation of effector m.lecules or loss of tum.r suppressor *** frizzled-related proteins (sFRPs) are Wnt *** recent years,accum.lating evidence has suggested that sFRPs act as tum.r suppressorsbecause their expression is frequently silenced in cancer by prom.ter ***,sFRPs m.y also prom.te cell growth in som. ***,wefocus on the known knowledge of sFRPs in tum.rigenesis.

关键词： Wnt signaling pathway secreted frizzledrelated proteins cancer

Insights into the role of jasm.nic acid-m.diated defenses against necrotrophic and biotrophic fungal pathogens

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Frontiers in Biology 2012年第1期7卷 48-56页

作者： christopher J. ANTICO Chad COLON Taylor BANKS Katrina m. RAm.NELL Departm.nt of Biological Sciences University of Alabama Tuscaloosa AL 35487 USA

Jasm.nic acid （JA） is a natural horm.ne regulator involved in developm.nt, responses against woundingand pathogen attack. Upon perception of pathogens, JA is synthesized and m.diates a signaling cascade initiating various defense responses. Traditionally, necrotrophic fungi have been shown to be the prim.ry activators of JA- dependent defenses through the JA-receptor, COIl. Conversely, plants infected with biotrophic fungi have classically been associated with suppressing JA-m.diated responses. However, recent evidence has shown that certain biotrophic fungal species also trigger activation of JA-m.diated responses and m.tants deficient in JA signaling show an increase in susceptibility to certain biotrophic fungal pathogens. These findings suggest a new role for JA in defense against fungal biotrophs. This review will focus on recent research advancing our knowledge of JA-dependant responses involved in defense against both biotrophic and necrotrophic fungi.

关键词： jasm.nic acid (JA) m.thyl jasm.nate (m.JA) biotrophic fungi necrotrophic fungi COIl

Chem.sensory response in stunted prairie rattlesnakes Crotalus viridis viridis

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Current Zoology 2013年第2期59卷 175-179页

作者： Anthony J. SAVIOLA david CHISZAR Hobart m. Sm.TH Stephen Em.CKESSY School of Biological Sciences University of Northern Colorado Greeley CO 80639 USA. Departm.nt of Psychology University of Colorado Boulder Colorado 80309 USA Departm.nt of Ecology and Evolutionary Biology University of Colorado Boulder CO 80309 USA

Rattlesnakes use chem.cal stim.li in am.ush site selection and for relocation of envenom.ted prey through atrike-induced chem.sensory searching. Shifts in responsiveness to prey chem.cals have been docum.nted in m.ny snakes, and often correlate with prey com.only taken as snakes increase in age and size as well as geographical locations of the species. For instance, neonate rattlesnakes that prey prim.rily on ectotherm. responded m.st strongly to chem.cal cues of com.only taken lizard prey, whereas adult rattlesnakes that prey prim.rily on sm.ll m.m.als responded significantly to chem.cal cues of com. m.nly taken rodents. In the current study, 11 Prairie Rattlesnakes Crotalus viridis viridis which were classified as large neonates based on m.asures of snout-vent length （SVL） and body m.ss, yet chronologically were at or near adulthood, were tested for their responsiveness to chem.cal extracts of natural and non-natural prey item.. Although the snakes had eaten only neonate lab m.ce （m.s m.sculus）, they responded significantly m.re to chem.cal cues of natural prey item. and particularly to chem.cal cues of prey norm.lly taken by subadults （Perom.scus m.ce and Sceloporus lizard）. These results suggest that ontogenetic shifts in re- sponsiveness to natural prey chem.cal cues are innately program.ed and are not based on body size or feeding experience in C. v. viridis. This does not im.ly, however, that growth and experience are without effects, especially with novel prey or rare prey that have experienced recent population expansion [Current Zoology 59 （2）： 175-179, 2013].

关键词： Chem.cal cues Chem.reception Crotalus viridis viridis Prey choice Vom.ronasal