Molecular characterization and functional expression of opioid receptor-libe_1 receptor

INTRODUCTIONOpioidactsinthecentralandperipheralnervoussystem(CNSandPNS)to'producenumerouspharmacologicaleffects.Repetitiveorcontinuoususeofopioids,however,causesdrugtoleranceanddependence.Threesubtypesofopioidreceptors,termedp)6,andK,havebeencloned.TheyarecoupledtotheinhibitoryGproteinandnegativelyregulateadenylylcyclasell].RecentlyanewG-proteincoupledreceptortermedopioidreceptor-likereceptor(ORLI)whichbelongstothenewlycharacterizedopioidreceptorsubfamilyhadbeenclonedfromhumanbrainst…     

Exact Controllability of Age-Structured Predator-Prey Populations

1IntroductionT5e劝dysisd8贝ami。dpTdatO。preynit。ti。is4iquitousinthebiologicalworldandlsd。id既曲ienit。estan6ipeceto。IOgy．Thetheoretidstudydpredation晌hadahghistoryho。lugwiththe。nalworkofInne．aandVolt。,andcontin。tobeofwid聊readinterest咖y．仇iiithelateof1980’s,most…ator－pteystUdieshavebudonInteractingspedeswithoutsg。sin．－Cture（forexmple,sce［1」,［2」,［3」and［4］）．HOwever,asthelin阿mceof明卜s刎cmreInpoPulaMnhasbecomemorewidelyrecognized,thereisanIn－er。lugnum…     

NEW MATERIAL OF HSISOSUCHUS CHUNGKINGENSIS FROM SICHUAN, CHINA

AnewspecimenofHIitoIuchuschungkingensis,inc1udingthecraniumandmostofthep0stcranium,wascollectedbyone0fus(X.-M-Li)inearlyl960sfr0mthJurassicsandstoneoftheSangqia0area,Yongchuancounty,about60kmsouthwesIofChongqing.Thisspecimenpr0babIyrepresentsayoungadult0rasubadu1t,a5indicatedbyitssmal1size(lessthan2/3length0fthetype,basedontheskul]proportion)andopensuturesbetweenpalatalelements.lnthepresentpaperwewillredescribeH.chungkingensisindetailbasedonb0ththetypeandnewlydis-coveredspecimensinordertoc…     

A NEW PADDLEFISH FROM THE UPPER JURASSIC OF NORTHEAST CHINA

orderAdpenseriformesBerg,l94oFaedyPolyodontidaeBonaparte,l838Genu8Protopsephuru8gen.nov.TyPespede8P.liuigen.etsp.nov.Protopsephuru8liuigen.etsp.nov.(Fig.1Ipl.1)HolotypeAnearlycompletefishanditscounterpart,lackingpartofitscau-dalfin.GMV2032-la,b.Horizonandl0ealityUpperJurassicYixianF0rmation,S0ngzhangzivillage,LingyuanCounty,LiaoningProvince.Diagn0chPadd1efishofmiddlesizewithtotallengthreachinglm0rmore.Rostralpartisaboutl/40fthefishlengthwithmanyr0stralsandrareste1latebones.Derm0sphe…     

PHYLOGENETIC RELATIONSHIP OF HSISOSUCHUS

ThePoposauridae,representedbyPostosuchus(Chatterjee,1985),washypothe-sizedbymostworkersmentionedaboveasthesistergroupoftheCrocodylomor-pha.Consequently,PostotuchusandDibothrosuchus(Wu,l986;WuandChatterjee,l993),thebestknownsphenosuchian,arechosenastwosuccessiveoutgroupswhenpolarizingthecharacterstatesusedinthisstudy.Asmentionedintheearlierpa-per(Lietal.,l994),Hsisosuchusismorphologica1lyratherprimitiveinanumberofaspects,suchasthepresenceofalargeantorbitalfenestra,thepairedfrontals,theanter…     

几种旋尾目寄生线虫的研究

在W.Yorke与P.A.Maplestone(1926)的著作里,旋尾总科(Spiruroidea Raillietet Henry,1915)和丝虫总科(Filarioidea Weinland,1858;Stiles,1907)是两个独立的总科。Chitwood(1933),与(1940)等把上述两类和驼形类(CamallanataChitwood,1936)合并成为旋尾目(Spirurida Chitwood,1933)。     

A Lipidomic Study of the Effects of N-methyl-N′-nitro-N-nitrosoguanidine on Sphingomyelin Metabolism

Systems biology is a new and rapidly developing research area in which,by quantitativelydescribing the interaction among all the individual components of a cell,a systems-level understanding of abiological response can be achieved.Therefore,it requires high-throughput measurement technologies forbiological molecules,such as genomic and proteomic approaches for DNA/RNA and protein,respectively.Recently,a new concept,lipidomics,which utilizes the mass spectrometry(MS)method for lipid analysis,has been proposed.Using this lipidomic approach,the effects of N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)on sphingomyelin metabolism,a major class of sphingolipids,were evaluated.Sphingomyelin moleculeswere extracted from cells and analyzed by matrix-assisted laser desorption ionization-time of flight MS.Itwas found that MNNG induced profound changes in sphingomyelin metabolism,including the appearance ofsome new sphingomyelin species and the disappearance of some others,and the concentrations of severalsphmgomyelin species also changed.This was accompanied by the redistribution of acid sphingomyelinase(ASM),a key player in sphingomyelin metabolism.On the other hand,imipramine,an inhibitor of ASM,caused the accumulation of sphingomyelin.It also prevented some of the effects of MNNG,as well as theredistribution of ASM.Taken together,these data suggested that the lipidomic approach is highly effectivefor the systematic analysis of cellular lipids metabolism.     

加强科研管理工作,营造科研创新环境

随着我国科研工作的发展和科技体制改革的不断深化,科学研究领域的竞争也日益激烈。加强医院科研管理,强化科技意识,提高管理水平,对推动医学科学技术的发展具有十分重要的意义。近年来,我院深化改革,走科技兴院的道路,制定一系列科研奖励政策,不断充实完善基础研究设施建设,加     

Proton NMR investigation of heme and surrounding proton in low-spin cyanide-ligated bacterial hemoglobin fromVitreoscilla

1H NMR spectra of low-spin cyanide-ligated bacterial hemoglobin from Vitreoscilla (VtHb-CN) are reported. The assignments of the 1H NMR spectra of VtHb-CN have been made through MCOSY, NOESY, 1D TOE and SUPERWEFT experiments. Almost all resonance peaks of heme and ligated His85 are identified. The spin-lattice relaxation time T1's and the variation relationships of chemical shifts of these peaks with temperature have been acquired, from which the distances between the measured protons and Fe3 , and the diamagnetic chemical shifts have been acquired, respectively. The ionization constants of pKa's of ligated His85 are determined through pH titration of chemical shift, which is 4.95 for ligated His85 C2H proton. The lower pKa is attributed to the influence of the Fe3 of carrying positive charge and the coordination of His85 and Fe3 of heme.     

Functional difference between Sinorhizobium meliloti NifA and Enterobacter cloacae NifA

The nifA gene is an important regulatory gene and its product, NifA protein, regulates the expression of many nif genes involved in the nitrogen fixation process. We introduced multiple copies of the constitutively expressed Sinorhizobium meliloti (Sm) or Enterobacter cloacae (Ec) nifA gene into both the nifA mutant strain SmY and the wild-type strain Sm1021. Root nodules produced by SmY containing a constitutively expressed Sm nifA gene were capable of fixing nitrogen, while nodules produced by SmY containing the EC nifA gene remained unable to fix nitrogen, as is the case for SmY itself. However, transfer of an additional Sm nifA gene into Sm1021 improved the nitrogen-fixing efficiency of root nodules to a greater extent than that observed upon transfer of the EC nifA gene into Sm1021. Comparative analysis of amino acid sequences between Sm NifA and EC NifA showed that the N-terminal domain was the least similar, but this domain is indispensable for complementation of the Fix-phenotype of SmY by Sm Ni