学科分类
/ 20
389 个结果
  • 简介:目的:讨抑郁症的神经生物学发病机制,揭示针刺治疗抑郁症的机理。方法:以Wistar大鼠为受试对象,采用给予孤养大鼠以长期不可预见的中等强度刺激的方法建立抑郁大鼠模型,检测应激后造成的抑郁模型大鼠行为学改变、下丘脑垂体肾上腺皮质轴(HPA)的变化,同时观察针刺干预效应及不同针法的疗效比较。结果:型组、生理盐水组血清CORT和ACTH含量明显高于正常对照组(P〈0.05);手针治疗组、电针治疗组血清CORT和ACTH含量明显低于模型组(P〈0.05);药物组血清CORT和ACTH含量明显低于生理盐水组(P〈0.05):手针治疗组、电针治疗组、药物组比较差别无统计学意义。结论:刺百会、太冲具有较明显的抗抑郁效应,其机制可能与针刺对HPA轴的调整有关。

  • 标签: 抑郁症 针刺疗法 下丘脑-垂体-肾上腺皮质轴
  • 简介:Centralnervoussystem(CNS)injuriescausedbycerebrovascularpathologies(e.g.,stroke)ormechanicalcontusions(e.g.,traumaticbraininjury)disrupttheblood-brainbarrier(BBB)thatprotectstheCNSmicroenvironmentfromadirectcontactwithbloodsubstancesandcells.Theinitialneuraldamagecausedbythetraumaandtheischemicprocess

  • 标签: 神经保护 内质网应激 中枢神经系统 道路 瘢痕 胶质
  • 简介:Thedynamicstressintensityfactorhistoryforahalfplanecrackinanotherwiseunboundedelasticbody,withthecrackfacessubjectedtoatractiondistributionconsistingoftwopairsofcombinedmodepointloadsthatmoveinadirectionperpendiculartothecrackedgeisconsidered.Theanalyticexpressionforthecombinedmodestressintensityfactorsasafunctionoftimeforanypointalongthecrackedgeisobtained.ThemethodofsolutionisbasedontheapplicationofintegraltransformtogetherwiththeWiener-HopftechniqueandtheCagniard-deHoopmethod.Somefeaturesofthesolutionarediscussedandgraphicalresultsforvariouspointloadspeedsarepresented.

  • 标签: MOVING loads A HALF PLANE CRACK
  • 简介:Thestressintensityfactor(SIF)isacriticalparameterassociatedwiththefracturebehaviourofmaterials.Inthispaper,weselectthedisplacementfunctionaroundacracktipastheshapefunctionofthedigitalimagecorrelation(DIC),whichmakesitpossibletodirectlycalculatetheSIFbythecorrelationscheme.Moreover,weuseanon-rectangularsubset,whichcanreducetheinfluenceofplasticdeformationandcrackwidthontheDICmeasurementaccuracy.WemeasuredtheSIFofamodeIcrackinasuper-hardaluminiumalloyspecimentoverifytheperformanceoftheproposedmethod.OurexperimentalresultsshowthataDICwithaspecificshapefunctioncanbeusedtoaccuratelyandefficientlycalculatetheSIF.Furthermore,wealsopresentapracticalapplicationofourproposedmethodfordeterminingtheSIF,crackpropagationangleandcracktipdisplacement.

  • 标签: Digital image CORRELATION (DIC) SHAPE function
  • 简介:Stronglyswirlflowsimulationarestillunderdeveloping.Inthispaper,εequationbasedontheRenormalizationGrouptheoryisusedintoalgebraicstressmodel.Standardk-εmodel,algebraicstressmodelbyJiangZhang^[5]andpresentmodel(RNG-ASM)areappliedsimultaneouslytosimulatingtheconfinedstronglyswirlingflow.TheSimulatingresultsbyRNG-ASMmodelarecomparedtotheresultsbyothertwomodel,itisshownthatthepredictionsbythismodeldisplayreasonableagreementwithexperimentaldata,andleadtogreaterimprovementthanZhang'sASMturbulencemodel^[5].

  • 标签: 湍流 重整体群法 数字模拟
  • 简介:进行中的气候变化是对生物多样性的主要威胁。不管多么许多种类清楚地受不了进行中的气候变化,例如,其它由显示出范围扩大得益于它。然而,特定的特征哪个决定种类危险到气候变化?Phenotypic粘性,对环境变化被描述了为防卫的第一根线,可能在这里具有最大的重要性。对这个背景,我们这里在3铜蝴蝶种类在压力忍耐比较粘性,它在他们对气候变化的弱点可以证明不同。明确地,我们在成年阶段在acclimatization以后调查了热,寒冷和干燥抵抗到不同温度。我们证明在更高的温度的环境适应增加了热,但是减少冷忍耐和干燥抵抗。与我们的预言相反,种类没在压力抵抗显示出显著变化,尽管在温度的塑料能力强调抵抗确实越过种类变化了。总的来说,我们的结果似乎比speciesspecific模式反映populationrather。我们断定使用的人口的地理起源应该在比较研究被认为平。然而,我们的结果建议在这里学习的3种类,对气候变化的弱点没被压力抵抗首先在成年阶段决定。当昆虫学的研究仅仅实在太经常集中于成年人,当试着理解昆虫回答到环境变化时,我们主张更多的研究努力应该被奉献给另外的发展阶段。

  • 标签: 气候变化 成年人 压力 危险 蝴蝶
  • 简介:

  • 标签:
  • 简介:Membersoftheactivityofbc1complex(ABC1)familyareproteinkinasesthatarewidelyfoundinprokaryotesandeukaryotes.PreviousstudiesshowedthatseveralplantABC1genesparticipatedintheabioticstressresponse.Here,wepresentthesystematicidentificationofriceandArabidopsisABC1genesandtheexpressionanalysisofriceABC1genes.Atotalof15and17ABC1genesfromthericeandArabidopsisgenomes,respectively,wereidentifiedusingabioinformaticsapproach.Phylogeneticanalyseso...

  • 标签:
  • 简介:Objective:Tostudytheinfluenceofstress-relaxationplateondisorganizationandrepairofthecortexbeneaththeplate.Methods:Awashermadeofviscoelasticpolyethylenewasplacedbetweenthescrewandthescrewholeofconventionalstainlessrigidplate(RP)toproduceastressrelaxationplate(SRP).BothSRPandRPwereappliedtoosteotomizedtibiain48NewZealandrabbits.HealingprocessofthefracturewitheitherSRPorRPfixation(control)wascomparativelystudiedwithpolarizedlightmicroscopy,insituhybridizationofcollagenmRNAandimmunohistochemicaltechniquefrom2to36weekspostoperatively.Results:ThestudyofplatedboneremodelingshowedthatthedegreeofcortexosteoporosisbeneaththeplatewassimilarbetweentheSRPandRPgroupwithin12weekspostoperatively.Incomparison,thedisorganizationofbonestructureinSRPgrouphappenedlaterandmilderthanthatofRPgroup,andtherepairprocessbeganat12weeksafterimplantation.Asaconsequence,theabsorptioncavitiesbecamesmallerandthestructureofcollagenfibersbecamewellorientedalongwiththesechangesbypolarizedlightmicroscopy.Inadditiontothese,theinsituhybridizationanalysisofcollagengenesandtheimmunohistochemicalstudyoftypeI,Ⅲcollagenat8to12weeksafterimplantation.fromthistimeon,thechangesabovebecamemoreevidentsignificantlybeforemostofcavitieswererepairedby36weeks.IncontrasttothechangesintheSRPgroup,noexpressionandsynthesisofanykindofcollagencouldbeobservedduring12to36weeksafterimplantationinRPgroup.Conclusions:Withoutremovaloftheboneplate,theSRPfixationnotonlyreducesthedegreeofplatedboneosteoporosis,butalsomakesthedisorganizedbonestructurerestoredtonormalintermsoftheexpressionandsynthesisoftypeIcollagenmRNAofosteoblastslyingonthesurfaceofabsorptioncavities.

  • 标签: 骨板 内固定 胶原 局部骨修复
  • 简介:Consideringtheeffectsofparticlecrushingandintermediateprincipalstressonmaterialyieldingstrength,thespatialmobilizationplane(SMP)yieldingcriterionandstateparametermodelincludingageneralcriticalstatelineareselectedintheanalysisofcylindricalcavityexpansion.Meanwhile,combiningRowe'sflowruleandBolton'ssimplificationtostress-dilatancyrelationshiptoreflectsoilsheardilatancyandsofteningbehavior,thispaperanalyzestheproblemofcylindricalcavityexpansioni...

  • 标签: 空间动员飞机(对称多处理) 理论 粒子压碎 弄软紧张 discretization 分析 塑料地区
  • 简介:ThispaperpresentsanexperimentalinvestigationonanAISI316Lstainlesssteelregardingmechanicalproper-tiesandshortuniaxialcreeptestsatelevatedtemperatures.Theshorttimecreeptestswerecarriedoutunderdifferentbutconstantstresses.Theobtaineddataofultimatetensilestrength,yieldstrength,creepcurvesandeffectsofelevatedtemperaturesonmechanicalpropertieswerepresented.Foraselectedrheologicalmodel,materialparameterswereobtained.Asajustification,suchrheologicalmodelisimplementedinthefiniteelementprocedureforanuniaxiallystressedspecimeninselectedenvironmentalconditions.

  • 标签: 316L不锈钢 单轴蠕变试验 高温力学性能 应力状态 行为 流变模型
  • 简介:基于Si的多层的结构广泛地在当前的微电子学被使用。在他们的准备期间,一些不同类的剩余应力被导致,导致在接口错配和表面精力和平导致结构失败之间的竞争。这个工作在多层的半导体heterostructure在剩余应力的测量上介绍方法学的研究。扫描电子显微镜学(SEM),micro-Raman光谱学(太太),和传播电子显微镜学(TEM)被使用测量多层的结构的几何参数。在拉曼光谱和压力/紧张在上之间的关系[100]并且[110]水晶取向被决定分别地启用表面和剖面图剩余压力分析。基于印射结果的拉曼,沿着多层的heterostructure的深度的剩余应力的分发成功地被获得。

  • 标签: 剩余应力 多层的半导体 heterostructure Micro-Raman 光谱学(太太) 拉紧的硅 金者硅
  • 简介:Zygosaccharomycesrouxiiisasalt-tolerantyeastspeciescapableofremovingcadmium(Cd)pollutantfromaqueoussolution.Presently,thephysiologicalcharacteristicsofZ.rouxiiunderthestressofsodiumchloride(NaCl)andCdarepoorlyunderstood.ThisstudyinvestigatedtheeffectsofNaClandCdonthegrowth,oxidativestressandantioxidantenzymeactivitiesofZ.rouxiiafterstresstreatmentfor24h.ResultsshowedthatNaClorCdalonenegativelyaffectedthegrowthofZ.rouxii,butthegrowth-inhibitingeffectofCdonZ.rouxiiwasreducedinthepresenceofNaCl.FlowcytometryassayshowedthatunderCdstress,NaClsignificantlyreducedtheproductionofreactiveoxygenspecies(ROS)andcelldeathofZ.rouxiicomparedwiththoseintheabsenceofNaCl.Theactivitiesofsuperoxidedismutase(SOD),catalase(CAT),andperoxidase(POD)ofZ.rouxiiweresignificantlyenhancedby2%–6%NaCl,whichlikelycontributedtothehighsalttoleranceofZ.rouxii.ThePODactivitywasinhibitedby20mgL-1CdwhiletheSODandCATactivitieswereenhancedby8mgL-1Cdandinhibitedby20mgL-1or50mgL-1Cd.Theinhibitoryeffectofhigh-levelCdontheantioxidantenzymeactivitiesofZ.rouxiiwascounteractedbythecombineduseofNaCl,especiallyat6%.ThisprobablyaccountedforthedecreaseinCd-inducedROSproductionandcelldeathofZ.rouxiiafterincubationwithNaClandCd.OurworkprovidedphysiologicalcluesastotheuseofZ.rouxiiasabiosorbentforCdremovalfromseawaterandliquidhighlysaltyfood.

  • 标签: 镉(CD) 抗氧化酶活性 氧化应激 氯化钠 生长 酵母
  • 简介:Thedistributionofstressandstrainfieldsinamicro-structuralareaofaparticlereinforcedcompositeisstudiedbyacombinationofexperimentalandnumericalmethod(hybridmethod).Withtheex-perimentalvaluesofdisplacementsinamicro-regionastheboundaryloadingcondition,strainandstressfieldsinsidethemicro-regionarecalculatedbythefiniteelementmethodtmdertwodifferentkindsofmodel-ing,namely,asplanestressandplanestraincondition.Thedifferencesbetweenthetwokindsofmodelingconditionsasappliedtomicro-structuralareasarediscussed.

  • 标签: PARTICLE REINFORCED composite REAL microstructure hybrid
  • 简介:在FRP的剥离开现象加强了具体横梁在这份报纸被调查。基于横梁理论和破裂力学,一个新理论模型被建议在FRP具体的接口附近分析剥离开行为,它被剩余管理热压力。数字例子被举提供清楚的卓见进失败机制。一些建议被为FRP的最佳的设计提供加强的结构。

  • 标签: 热残余应力 剥离行为 混凝土梁 玻璃钢 加固 结构优化设计
  • 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:Thesystematiclaboratorystudiesontherolesofsulfate-reducingbacteria(SRB)inthestresscorrosioncracking(SCC)susceptibilityofX80steelsubjectedtocathodicpotentialhavebeenconductedinanearneutralpHsoilsolutionbyslowstrainratetests.ThecathodicpotentialandSRBincreaseindividuallytheSCCsusceptibilityofthesteelinthesoilsolution.ThepositiveroleoftheSRBactivitiesinSCCsusceptibilitydependsontheprolongationofpre-incubationtime,andtheSCCsusceptibilityofthesteelincreasesundermorenegativepotentials.What’smore,theappliedpotentialsandthepresenceofSRBworktogetherinpromotingtheSCCsusceptibilityofthesteel.But,thecombinedactionbecomeslimitedwithdecreasingcathodicpotentials.Therelationshipsbetweentheplasticitylossandthepermeablehydrogenconcentrationwereestablishedforthesteelinthesoilsolution,regardlessofunderopencircuitpotentialorcathodicpotentials,inboththesterileandSRBinoculatedconditions.Therelationshipsarepracticallysignificantfortheselectionofsafecathodicprotection(CP)potentialsinthepresenceofSRBinsoilenvironment.

  • 标签: CARBON STEEL Microbiologically influenced corrosio