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16 个结果
  • 简介:Languagesareforcommunicationandifyoualwaysworkaloneinlessons,youaredenyingyourselftheopporttmitytoputlanguageintouse.Workinginpairsandsmallgroupswillgiveyoumoretimetospendtryingoutnewlanguage.

  • 标签: 高中 英语 学法指导 学习兴趣 课外阅读
  • 简介:在胸腺的中央忍耐是为删除汽车的主要机制反应T房间。尽管有这,进圆周的自我反应的T淋巴细胞的逃跑揭示汽车免疫的威胁。补偿它的瑕疵,胸腺也与镇压功能生产Foxp3+CD4+CD25+规章的T房间的一个自然地发生的子集,能够控制汽车反应房间。Foxp3(叉头框P3),为房间的这个子集的系特定的标记,对他们的thymic开发和外部功能关键,并且还Foxp3驾驶的transcriptional程序直到现在大部分未定义。新兴的证据提供了卓见进它的角色:从Foxp3到的能力与象NFAT那样的另外的抄写因素合作,到目标的染色体宽的描述,基因直接由Foxp3跳了并且调整。这里,我们讨论自然地发生的规章的T房间的发现-他们的显型,发展,维护,和功能-大部分当他们被系特定的标记定义,Foxp3。

  • 标签: 免疫学 T细胞 抑制作用 胸腺
  • 简介:THEDYNAMICSOFMAINTAININGTHETROPICALCYCLONE9012AFTERITSLANDING¥LiangLi,WuZhiwei(MeteorologicalInstituteofFujianProvince,Fuzhou...

  • 标签: long maintenance ANGULAR MOMENTUM transport SPIN-UP
  • 简介:CouplingCharacterofPolarizationMaintainingOpticalFiberUndertheConditionofBend①②LIChangchun(NationalLab.ofMolecularandBimolecu...

  • 标签: Microdisturbed Theory Mode COUPLE POLARIZATION Maintaining
  • 简介:这个道理人人都懂,但人总是有惰性的,总需要多给一些鼓励!而我们正需要用这种方式去为别人加油,同时也为自己赢得自信!

  • 标签: ENGLISH 持之以恒 英语学习 in
  • 简介:这份报纸从1950~2003用测量数据在更低的黄河学习在满满的分泌物,侧面的生气的节变化和到来的流动和沉积状况之间的关系。自从1950,满满的分泌物显然减少了,到流动深度的隧道宽度的比率增加了。批评年度平均到来的沉积系数(定义为沉积集中的比率排出)并且分别地,在Huayuankou车站的分泌物为从Huayuankou发生在活动范围到Lijin的没有积聚的免职是约0.012和1,850m3s1。在这个基础上,一个数学模型被用来在不久的将来在可能的到来的流动和沉积条件下面在更低的黄河和它的相应满满的分泌物学习主要隧道的规模。影响主要隧道的规模的主要因素被分析,并且测量塑造并且坚持说一条中型的隧道被讨论。结果显示出在塑造主要隧道上免除Xiaolangdi水库的各种各样的水和沉积联合的效果并且建议在最近的到来的流动和沉积条件下面,与满满的分泌物塑造并且维持一条中型的隧道是可能的近似4,000m3s1。

  • 标签: 黄河下游 渠道 维护 来水来沙条件 平滩流量 通道宽度
  • 简介:backgroundBonemarrowmesenchymalstemcells(BMSCs)canbeisolatedandculturedtomanypassages.However,StemcellsincludingBMSCsquicklyundergosenescenceinculture.Thecellsenescenceandmulti-directionaldifferentiationhavehamperedproducingBMSCsinquantitywiththeirundifferentiatedstate.Inthisstudywereportanaturalcompound,vitaminC(Vc),maintainsBMSCsstemproperty.MethodsHumanBMSCswereisolatedfrombonemarrowandpurifiedby1.073g/mLdensitygradientcentrifugation.50ng/mLVcwereaddedtoBMSCsfordifferenttimepoint.FlowcytometrywasusedtodetectcellsurfacemarkersofBMSCswithorwithoutVctreatment.BMSCsproliferationwasanalyzedbyMTTassay.PCR(polymerasechainreaction)andreal-timePCRwereusedfordetectingc-kit,nanog,andOct-4genesexpressionlevels.DNAmethyltransferase(Dnmt)1andDnmt3blevelswerealsodetectedbyreal-timePCR.ResultsFlowcytometryshowedthatafterVctreatmentfor6h,thesurfacemarkersofBMSCswerealmostunchanged.VcincreasedtheproliferationactivityofBMSCsfrom6hto24h.PCRshowedtheexpressionofc-kit,nanog,andoct-4geneswereobviouslyincreasedinVctreatedgroupthancontrolgroupat12h.Real-timePCRshowedthatthelevelofc-kit,nanog,andoct-4geneswereunregulatedfrom6hto12hcomparedwithcontrolgroup.VcalsoincreasedDnmt3bbutnotDnmt1geneexpression.ConclusionsOurresultsshowedVcactsatleastacceleratesBMSCsproliferationandmaintainsstemcellproperty.Inourstudy,wehighlightedamethodofimprovingthespeedofBMSCsgenerationandprovidedadditionalinsightsintothemechanisticbasisofpreventingBMSCssenescence.

  • 标签: 骨髓间质干细胞 维生素C 骨髓基质干细胞 自我更新 骨髓基质细胞 PCR检测
  • 简介:Wepresentapolarization-maintainingPANDAring-corefiber(PM-PRCF)characterizedbythecombinationofaring-corestructurewithtwostress-applyingrods.Thisspecialfiberdesignseparatestheadjacentmodesandavoidsthecutoffofthehigher-ordermodes,whichisacommonprobleminellipticalcorepolarization-maintainingfew-modefibers.Usingahigh-contrastindexringandstress-inducedbirefringence,thePM-PRCFfeaturessupportfor10vectormodes,witheffectiverefractiveindexseparationsfromtheiradjacentmodes>10-4.Broadbandperformanceisinvestigatedsubsequentlyoverawidewavelengthrangefrom1500to1630nm.Theproposedfiberistargetedatapplicationsinspace-divisionmultiplexingwhileeliminatingthecomplexmultiple-inputmultiple-outputsignalprocessing.

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  • 简介:Anewmethodisproposedtogeneratemicrowaveandmillimeter-wavebyusingpolarizationscramblerandpolarizationmaintainingfiber(PMF),whichisbasedonthecouplingandtheinteractionbetweenthetwopolarizationsoftheinitialnon-chirpGaussianopticalpulseinPMF.Theexpressionsofthemicrowaveandmillimeter-wavearederivedbycouple-modetheory.Moreover,thefeasibilityisanalyzedsimulatedly.Atlast,0-120GHzmicrowaveandmillimeter-wavecanbeproducedbyadjustingsystemparameterorinputpulseduration.Theprojectisofgreatsimplicity,stabilityandhighexportefficiency.

  • 标签: 毫米波 偏振波 微波 高斯光脉冲 光纤 护基
  • 简介:Influenceofthermal-mechanicalpropertiesonthefeaturesofthepandapolarization-maintainingopticalfiber(PMF)infabricationprocessisstudiedindetailbyfiniteelementmethod(FEM).Thestressbirefringenceis2.13443×10-4obtainedbythestaticanalysisand2.1269×10-4bydynamicanalysis.Thedifferenceinsimulationbytwomethodsisaround0.4%.Thenon-uniformityofstressbirefringenceinthefibercoreisabout1.6%.Predictedresultsdemonstratethateffectofthethermalconductiveparameteronfiberthermalstressdominates.Thehighanduniformstressbirefringenceinthefibercoreisobtainedbyappropriatelyselectingsuitablestressregionareaandposition.

  • 标签: 有限元 压力诱导 双折射 偏振保护光纤
  • 简介:Weproposeanovelwaveguidedesignofpolarization-maintainingfewmodefiber(PM-FMF)supporting≥10non-degeneratemodes,utilizingacentralcircularairholeandacircumjacentelliptical-ringcore.Thestructureendowsanewdegreeoffreedomtoadjustthebirefringenceofalltheguidedmodes,includingthefundamentalpolarizationmode.Numericalsimulationsdemonstratethat,byoptimizingtheairholeandelliptical-ringcore,aPM-FMFsupporting10distinctivepolarizationmodeshasbeenachieved,andtheeffectiveindexdifferenceΔneffbetweentheadjacentguidedmodescouldbekeptlargerthan1.32×10-4overthewholeC+Lband.TheproposedfiberstructurecanflexiblytailoredtosupportanevenlargernumberofmodesinPM-FMF(14-modePM-FMFhasbeendemonstratedasanexample),whichcanbereadilyapplicabletoascalablemodedivisionmultiplexingsystem.

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  • 简介:AfteroperationoftheThreeGorgesProject(TGP),thereisanewevolutiontendencyforriversandlakesinthemiddlereachesoftheYangtzeRiver(i.e.theChingRiverreaches).Inrecentyears,theweakeningconnectionrelationshipbetweentheYangtzeRiverandDongtingLakehasresultedinaseriesofproblemsforfloodregulation,waterresourcesutilization,andaquaticecosystemprotectionintheriver-lakejointarea.Inthispaper,thehydrologicalcharacteristicsandfluvialprocesseswithintheriver-lakejointareaarestudied,andpossiblemanagementstrategiestomaintaintheconnectedriver-lakerelationshipareproposed.Toachievethisobjective,theevolutiontendency,suchasthezero-flowproblemandriverregimeforthreemajoroutlets(i.e.theSongziOutlet,TaipingOutlet,andOuchiOutlet)toDongtingLakefromtheYangtzeRiver,isanalyzed.ItisbelievedthattheSongziOutlethasacomparativeadvantageinflowdiversionovertheothertwooutlets.TheRangeofVariabilityApproachisintroducedtoidentifyhydrologicalcharacteristicsattheSongziOutlet.Severalcharacteristicvaluesofflowdiversionfromthisoutletduringdroughtperiodsaredetermined.Then,thefluvialprocessesintheriver-lakejointareaarestudiedbycomparingtopographicmapsandusingcontrolgaugestationdataofvariousyears.ThewaterandsedimentfluxareanalyzedbeforeandafteroperationoftheTGP.Finally,basedontheresultsobtained,twopossiblemanagementstrategiesarerecommendedandcorrespondingparametersareestimatedtostrengthenandmaintaintheconnectedriver-lakerelationship.ThisanalysistakesintoaccountoperationoftheTGP,mainstreamshiftandincreasingriverbedscourintheChingRiverchannel.Torestoretheflowdiversionconditiontothatinthe1950sor1960s(i.e.140m3/sofflowdiversioncorrespondingto5500m3/sofflowattheZhichengstation),itisestimatedthattheriverchannelaroundtheSongziOutletshouldbedredged1.4munderthecurrentriverbedsituatio

  • 标签: River-lake relationship YANGTZE RIVER Dongting LAKE
  • 简介:Heatshockprotein70(HSP70)maintainsCa~(2+)homeostasisinPC12cells,whichmayprotectagainstapoptosis;however,themechanismsofneuroprotectionareunclear.Therefore,inthisstudy,weexaminedCa~(2+)levelsinPC12cellstransfectedwithanexogenouslentiviralHSP70geneexpressionconstruct,andwesubsequentlysubjectedthecellstoischemia-hypoxia/reoxygenationinjury.HSP70overexpressionincreasedneuronalviabilityandATPaseactivity,anditdecreasedcellularreactiveoxygenspecieslevelsandintracellularCa~(2+)concentrationafterhypoxia/reoxygenation.HSP70overexpressionenhancedtheproteinandmRNAexpressionlevelsofsarcoplasmic/endoplasmicreticulumCa~(2+)-ATPase(SERCA),butitdecreasedtheproteinandmRNAlevelsofinositol1,4,5-trisphosphatereceptor(IP3R),therebyleadingtodecreasedintracellularCa~(2+)concentrationafterischemia-hypoxia/reoxygenation.TheseresultssuggestthatexogenousHSP70protectsagainstischemia-hypoxia/reoxygenationinjury,atleastinpart,bymaintainingcellularCa~(2+)homeostasis,byupregulatingSERCAexpressionandbydownregulatingIP_3Rexpression.

  • 标签: 缺氧/复氧损伤 热休克蛋白70 PC12细胞 神经保护作用 细胞内 钙稳态
  • 简介:Ischemicpreconditioningelicitedbyanon-fatalbriefocclusionofbloodflowhasbeenappliedforanexperimentaltherapeuticstrategyagainstasubsequentfatalischemicinsult.Inthisstudy,weinvestigatedtheneuroprotectiveeffectsofischemicpreconditioning(2-minutetransientcerebralischemia)oncalbindinD28kimmunoreactivityinthegerbilhippocampalCA1areafollowingasubsequentfataltransientischemicinsult(5-minutetransientcerebralischemia).AlargenumberofpyramidalneuronsinthehippocampalCA1areadied4daysafter5-minutetransientcerebralischemia.IschemicpreconditioningreducedthedeathofpyramidalneuronsinthehippocampalCA1area.CalbindinD28kimmunoreactivitywasgreatlyattenuatedat2daysafter5-minutetransientcerebralischemiaanditwashardlydetectedat5dayspost-ischemia.IschemicpreconditioningmaintainedcalbindinD28kimmunoreactivityaftertransientcerebralischemia.Thesefindingssuggestthatischemicpreconditioningcanattenuatetransientcerebralischemia-causeddamagetothepyramidalneuronsinthehippocampalCA1areathroughmaintainingcalbindinD28kimmunoreactivity.

  • 标签: 海马CA1区 锥体神经元 缺血预处理 神经保护作用 免疫反应性 钙结合蛋白