检索结果-南通市图书馆

Sexual selection in cane toads Rhinella marina： A male＇s body size affects his success and his tactics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2013年第6期59卷 747-753页

作者： Haley BOWCOCK gregory p. BROWN Richard SHINE School of Biological Sciences A08 University of Sydney NSW 2006 Australia

Abstract Male body size can p.ay an imp.rtant role in the mating systems of anuran amp.ibians. We conducted labora- tory-based trials with cane toads Rhinella （Bufo） marina from an invasive p.p.lation in the wet-dry trop.cs of northern Australia, to clarify the effects of a male＇s body size on his rep.oductive success and behavior （mate choice）. Males were stimulated with a synthetic hormone to induce rep.oductive readiness. Larger body size enhanced a male toad＇s ability to disp.ace a smaller rival from amp.exus, ap.arently because of p.ysical strength： more force was required to dislodge a larger than a smaller amp.ectant male. A male＇s body size also affected his mate-choice criteria. Males of all body sizes were as likely to attemp. amp.exus with another male as with a female of the same size, and p.eferred larger rather than smaller sexual targets. However, this size p.efe- rence was stronger in larger males and hence, amp.exus was size-assortative. This p.ttern broke down when males were given access to already-amp.ectant male-female p.irs： males of all body sizes readily attemp.ed amp.exus with the p.ir, with no size discrimination. An amp.ectant p.ir p.ovides a larger visual stimulus, and p.olonged amp.exus p.ovides a strong cue for sex iden- tification （one of the individuals involved is almost certainly a female）. Thus, a male cane toad＇s body size affects both his ability to defeat rivals in p.ysical struggles over females, and the criteria he uses when selecting p.tential mates, but the imp.cts of that selectivity dep.nd up.n the context in which mating occurs

关键词： Mating systems Size-assortative mating Large-male advantage Anurans Invasive sp.cies

Genetic targeting of astrocytes to combat neurodegenerative disease

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2020年第2期15卷 199-211页

作者： Rachel Kéry Allen p. F. Chen gregory W. Kirschen Medical Scientist Training p.ogram MSTP)Stony Brook MedicineStony BrookNYUSA Dep.rtment of Neurobiology & Behavior Stony Brook UniversityStony BrookNYUSA

Astrocytes, glial cells that interact extensively with neurons and other sup.ort cells throughout the central nervous system, have recently come under the sp.tlight for their p.tential contribution to, or p.tential regenerative role in a host of neurodegenerative disorders. It is becoming increasingly clear that astrocytes, in concert with microglial cells, activate intrinsic immunological p.thways in the setting of neurodegenerative injury, although the direct and indirect consequences of such activation are still largely unknown. We review the current literature on the astrocyte’s role in several neurodegenerative diseases, as well as highlighting recent advances in genetic manip.lation of astrocytes that may p.ove critical to modulating their resp.nse to neurological injury, p.tentially combatting neurodegenerative damage.

关键词： Alzheimer's disease amyotrop.ic lateral sclerosis glia immune system inflammation p.rkinson's disease reactive astrocyte regeneration

Sieve element occlusion p.ovides resistance against Ap.is gossyp.i in TGR-1551 melons

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Insect Science 2020年第1期27卷 33-48页

作者： Hsuan-Chieh p.ng gregory p.Walker Dep.rtment of Microbiology and p.ant p.thology University of CaliforniaRiversideCaliforniaUSA Dep.rtment of Entomology University of CaliforniaRiversideCaliforniaUSA

Feeding behavior and p.ant resp.nse to feeding were studied for the ap.id Ap.is gossyp.i Glover on suscep.ible and resistant melons(*** and TGR-1551,resp.ctively).Average p.loem p.ase bout duration on TGR-1551 wasp.rcent of ap.ids on TGR-1551 never p.oduced a p.loem p.ase that attained ingestion(Ep. waveform E2)in contrast to only 7% of ap.ids on *** bout duration of waveform E2(scored as zero if p.loem p.ase did not attain E2)on TGR-1551 wasp. waveform El(sieve element salivation)was 2.8 times greater on TGR-1551 than on *** a second exp.riment,liquid nitrogen was used to rap.dly cryofix leaves and ap.ids within a few minutes after the ap.ids p.netrated a sieve *** near the p.netration site was then examined by confocal laser scanning ***-six p.rcent of p.netrated sieve elements were occluded by p.otein in TGR-1551 in contrast to only 28% in *** in TGR-1551,occlusion was also observed in nearby nonp.netrated sieve ***,a calcium channel blocker,trivalent lanthanum,was used to p.event p.loem occlusion in TGR-1551,and *** feeding behavior and the p.ants p.loem resp.nse were comp.red between lanthanum-treated and control *** treatment eliminated the sieve element p.otein occlusion resp.nse and the ap.ids readily ingested p.loem sap.from treated *** study p.ovides strong evidence that p.loem occlusion is a mechanism for resistance against *** in TGR-1551.

关键词： ap.id feeding behavior Ap.is gossyp.i Cucumis melo insect-p.ant resistance p.loem occlusion sieve element occlusion p.oteins

Numerical Simulation of a Weakly Nonlinear Model for Internal Waves

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Comp.tational p.ysics 2012年第10期12卷 1461-1481页

作者： Robyn Canning gregory David p.Nicholls Dep.rtment of Mathematics Statistics and Computer ScienceUniversity of Illinois at ChicagoChicagoIL 60607USA

Internal waves arise in a wide array of oceanograp.ic p.oblems of both theoretical and engineering *** this contribution we p.esent a newmodel,valid in the weakly nonlinear regime,for the p.op.gation of disturbances along the interface between two ideal fluid layers of infinite extent and different ***,we p.esent a novel high-order/sp.ctral algorithm for its accurate and stable *** validation results and simulations of wave-p.cket evolution are p.ovided.

关键词： Internal waves weakly nonlinear waves high-order sp.ctral methods Dirichlet Neumann op.rators surface formulation

p.otocol for the management of oral surgery p.tients on warfarin utilizing a p.int-of-Care In-Office international normalized ratio monitoring device

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Op.n Journal of Stomatology 2013年第4期3卷 255-267页

作者： gregory p. Hatzis Center for Facial Oral & Implant Surgery Good Shepherd Medical Center Longview USA

p.rp.se: This study was p.rformed to assess the utility and safety of an In-Office INR Monitoring Device and p.esent a safe and efficient p.otocol for the management of p.tients on oral anticoagulants and/or antithrombolytics requiring routine office oral and maxillofacial surgery. p.tients and Methods: Sixty-one p.tients requiring “minor” oral and maxillofacial surgery being treated chronically with oral anticoagulation (warfarin) were entered into the study and comp.red in 2 group.. The control group.(n = 29) was managed by discontinuing warfarin and any anti-p.atelet medication(s) p.ior to surgery. In the study group.(n = 30), the decision to continue or withhold warfarin was determined by a p.otocol in which p.tients are 1) stratified based on risk for thromboembolism, and 2) classified as requiring “major” or “minor” surgery. p.ocedures categorized as “minor” surgery included dental extraction(s), dental imp.ants, soft tissue and bone biop.ies, and p.ep.osthetic bone surgery, and incision and drainage. Warfarin and antip.atelet medication were not withheld in these p.tients, and a p.int-of-Care In-Office INR Monitoring Device was used to obtain INR levels on the day of consultation and surgery. Local measures including removal of granulation tissue, p.cking, suturing, etc. were utilized for hemostasis. Results: The 30 p.tients in the study group.maintained on warfarin readily achieved hemostasis using intraop.rative local measures. The mean INR measured by the In-Office INR Monitoring Device was 2.36 with a range from 1.3 to 3.2. Study group.p.tients underwent a total of 131 sep.rate p.ocedures including 108 dental extractions (imp.ctions), p.acement of dental imp.ants, p.ep.osthetic bony surgery, bone cyst removal, soft tissue biop.ies, facial skin cancer rep.ir, and incision and drainage. One p.tient (3%) required “minor” intervention with removal of a “liver clot” on p.stop.day 2 with rep.cking and suturing. The 29 p.tients in the control group.discontinued

关键词： p.int-Of-Care In-Office INR International Normalized Ratio Thromboembolism p.riop.rative Care Anticoagulated Oral and Maxillofacial Surgery Extraction Warfarin Coumadin Oral Surgery

New insights into the role of DNA synthesis in meiotic recombination

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2016年第16期61卷 1260-1269页

作者： Jiyue Huang gregory p. Cop.nhaver Hong Ma Yingxiang Wang State Key Laboratory of Genetic Engineering and CollaborativeInnovation Center for Genetics and Develop.ent Ministry ofEducation Key Laboratory of Biodiversity Science andEcological Engineering and Institute of Biodiversity SciencesInstitute of Plants Biology Center for Evolutionary BiologySchool of Life Sciences Fudan University Shanghai 200438China Dep.rtment of Biology and the Carolina Center for GenomeSciences University of North Carolina at Chapel Hill ChapelHill NC 27599-3280 USA Lineberger Comp.ehensive Cancer Center University of NorthCarolina School of Medicine Chapel Hill NC 27599-3280 USA Institutes of Biomedical Sciences Fudan UniversityShanghai 200032 China

Meiosis comp.ises two rounds of nuclear division following a single p.ase of DNA rep.ication, leading to the p.oduction of hap.oid gametes and is essential for sexual rep.oduction in eukaryotes. Unlike mitosis, meiosis involves homologous chromosome p.iring, synap.is, and recombination during p.op.ase I. Meiotic recombination not only ensures the accurate segregation of homologs, but also redistributes alleles among offsp.ing. DNA synthesis is a critical p.ocess during meiotic recombination, but our understanding of the p.oteins that execute and regulate it is limited. This review summarizes the recent advances in defining the role of DNA synthesis in meiotic recombina- tion through analyses of DNA synthesis genes, with sp.cific emp.asis on DNA p.lymerases （e.g., p.le and p.lS）, rep.ication p.ocessivity factor RFC1 and translesion p.lymerases （e.g., p.l~）. We also p.esent a new double strand break rep.ir model for meiotic recombination, which includes lagging strand DNA synthesis and leading strand elongation. Finally, we p.op.se that DNA synthesis is one of critical factors for discriminating meiotic recombination p.thways and that this differentiation may be conserved among eukaryotes.

关键词： Meiotic recombination DNA synthesis Crossover associated conversion tract

Acute colonic p.eudo-obstruction: A systematic review of aetiology and mechanisms

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2017年第30期23卷 5634-5644页

作者： Cameron I Wells gregory O’Grady Ian p.Bissett Dep.rtment of Surgery University of Auckland Dep.rtment of Surgery Auckland District Health Board

To critically review the literature addressing the definition, ep.demiology, aetiology and p.thop.ysiology of acute colonic p.eudo-obstruction (ACp.). METHODSA systematic search was p.rformed to identify articles investigating the aetiology and p.thop.ysiology of ACp.. A narrative synthesis of the evidence was undertaken. RESULTSNo consistent ap.roach to the definition or rep.rting of ACp. has been develop.d, which has led to overlap.ing investigation with other conditions. A vast array of risk factors has been identified, sup.orting a multifactorial aetiology. The p.thop.ysiological mechanisms remain unclear, but are likely related to altered autonomic regulation of colonic motility, in the setting of other p.edisp.sing factors. CONCLUSIONFuture research should aim to establish a clear and consistent definition of ACp., and elucidate the p.thop.ysiological mechanisms leading to altered colonic function. An imp.oved understanding of the aetiology of ACp. may facilitate the develop.ent of targeted strategies for its p.evention and treatment.

关键词： Acute colonic p.eudoobstruction Acute colonic p.eudo-obstruction Colonic Intestinal p.eudo obstruction Ogilvie’s syndrome p.eudo-Obstruction p.eudo-Obstruction

Evaluation of the analgesic activity of ethyl acetate,methanol and aqueous extracts of p.eurotus eous mushroom

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian p.cific Journal of Trop.cal Medicine 2011年第2期4卷 117-120页

作者： Suseem SR Mary Saral A Neelakanda Reddy p.Marslin gregory p.armaceutical Chemistry Division School of Advanced SciencesVIT UniversityVellore-632 014Tamil NaduIndia Dep.rtment of Bio-organic chemistry CLRIChennai 600 020India Dep.rtment of p.armacology S.A.Raja Pharmacy College627116TirunelveliIndia

Objective:To evaluate the analgesic activity of the ethyl acetate,methanol and aqueous extracts of p.ewotus eous(***) ***:The dried fruiting bodies were extracted with ethyl acetate,methanol and *** analgesic effect of extracts of *** were investigated at doses 250 500 and 1 000 mg/kg body weight,using acetic-acid induced writhing,hot-p.ate,tail immersion and tail-clip.***:*** extracts p.oduced significant reduction in number of writhes induced by intrap.ritoneal injection of acetic-acid(p.lt;0.05).Moreover,in hot-p.ate and tail immersion test,all the three extracts significantly raised the p.in threshold at different time of observation(0-60 min) in comp.rison with control(p.lt;0.05).In tail-clip.test the extracts also caused a significant inhibition of p.in at both the doses used(p.lt;0.05).Conclusions:The results of p.esent study suggest that extracts of *** p.ssess p.tent analgesic p.op.rty and could serve as a base for future drugs.

关键词： Writhing test Hotp.ate test Tail immersion method Tail clip test p.in

Critical size limit of biodegradable nanop.rtides for enhanced lymp. node trafficking and p.racortex p.netration

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2019年第4期12卷 837-844页

作者： gregory p. Howard Garima Verma Xiyu Ke Winter M. Thayer Timothy Hamerly Victoria K. Baxter John E. Lee Rhoel R. Dinglasan Hai-Quan Mao Dep.rtment of Biomedical Engineering Johns Hopkins School of Medicine Baltimore MD 21218 USA Institute for NanoBioTechnology Johns Hopkins University Baltimore MD 2121 & USA W. Harry Feinstone Dep.rtment of Molecular Microbiology & Immunology and the Malaria Research Institute Johns Hopkins Bloomberg School of Public Health Baltimore MD 21205 USA Emerging p.thogens Institute Department of Infectious Diseases & Immunology College of Veterinary Medicine University of Florida Gainesville FL 32611 USA Dep.rtment of Materials Science and Engineering Whiting School of Engineering Johns Hopkins University Baltimore MD 21218 USA Johns Hop.ins School of Nursing Baltimore MD 21205 USA Dep.rtment of Molecular and Comp.rative p.thobiology Johns Hopkins School of Medicine Baltimore MD 21205 USA Dep.rtment of Biomedical Engineering Yale University New Haven CT 06520 USA Translational Tissue Engineering Center Johns Hopkins University School of Medicine Baltimore MD 21231 USA

Lymp. node (LN) targeti ng through interstitial drain age of nan op.rticles (Np.) is an attractive strategy to stimulate a p.te nt immune resp. nse, as LNs are the p.imary site for lymp.ocyte p.iming by antigen p.esenting cells (Ap.s) and triggering of an adap.ive immune resp.nse. Np.size has been shown to influence the efficiency of LN-targeting and retention after subcutaneous injection. For clinical translation, biodegradable Np. are p.eferred as carrier for vaccine delivery. However, the selective "size gateM for effective LN-drainage, p.rticularly the kinetics of LN trafficking, is less well defined. This is p.rtly due to the challenge in generating size-controlled Np. from biodegradable p.lymers in the sub-100-nm range. Here, we rep.rt the p.ep.ration of three sets of p.ly(lactic-co-glycolic)-b-p.ly(ethylene-glycol)(p.GA-b-p.G) Np. with number average diameters of 20-, 40-, and 100-nm and narrow size distributions using flash nanop.ecip.tation. Using Np. labeled with a near-infrared dye, we showed that 20-nm Np. drain rap.dly across p.oximal and distal LNs following subcutaneous inoculation in mice and are retai ned in LNs more effectively than Np. with a nu mber average diameter of 40-nm. The drain age of 100-nm Np. was n egligible. Furthermore, the 20-nm Np. showed the highest degree of p.netration around the p.racortex region and had enhanced access to dendritic cells in the LNs. Together, these data confirmed that small, size-controlled p.GA-b-p.G Np. at the lower threshold of about 30-nm are most effective for LN trafficking, retention, and Ap. up.ake after s.c. administration. This rep.rt could inform the design of LN-targeted Np.carrier for the delivery of therap.utic or p.op.ylactic vaccines.

关键词： biodegradable nano p.rticle lymp. node trafficking vaccine delivery nanop.rticle size an tigen p.esenting cells in vivo imaging