简介：Objective.Tostudytheeffectofecdysterone(ECR)onbeta-amyloidpeptidefragment25-35(Aβ25-35)-inducedPC12cellcytotoxicity,andfurthertoexporeitsmechanism.Methods:PC12survialwasmonitoredbyLDHreleaseand3-(4,5-dimethylthiazol-yl-2,5-diphenyhetrazoliumbromide(MTT)assays.Thecontentofmalondi-

简介：Alzheimer’sdisease(AD)isthemostcommontypeofdementiainelderlypopulation.WithagrowingagingpopulationnotonlyintheUnitedStatesbutalsointheworldwide,ADconstitutesanemergentpublichealthproblem.Overdecades,theprevailinghypothesiswasthatneurodegenerationmightresultfromoneortwoofthespecificlesions

简介：随着IM软件市场竞争的日趋激烈,MSN与腾讯QQ为了巩固自己的一片领土相继推出新的版本。新年伊始,腾讯推出了最新版本QQ2003IIIbeta4,它的体积也达到了恐怖的12M,而与前几个版本相比,此次的更新可谓是意义非凡……

简介：导读：讨论如何解决MicrosoftVisualC++2005中在加载程序锁定期间调用MSIL函数的问题。

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简介：BACKGROUND:PreparationofGinkgoleafhasbeenwidelyusedtoimprovecognitivedeficitsanddementia,inparticularinAlzheimer'sdiseasepatients.However,theprecisemechanismofactionofGinkgoleafremainsunclear.OBJECTIVE:ToexploretheeffectofGinkgoBilobaextract(Egb761),Ginaton,onβ-secretaseexpressioninrathippocampalneuronalculturesfollowingchronichypoxicandhypoglycemicconditions.DESIGN,TIMEANDSETTNG:Completelybyrandomized,groupingstudy.TheexperimentwasperformedattheLaboratoryofMolecularImaging,SoutheastUniversitybetweenAugust2006andAugust2007.MATERIALS:Atotalof128Wistarratsaged24hourswereselected,andhippocampalneuronswereharvestedforprimarycultures.METHODS:Onday7,primaryhippocampalneuronalculturesweretreatedwithEgb761(0,25,50,100,150,and200μg/mL)underhypoxic/hypoglycemicorhypoglycemiccultureconditionsfor12,24,and36hours,respectively.Hippocampalneuronsculturedinprimaryculturemediumservedascontrol.MAINOUTCOMEMEASURES:Cellviabilitywasassayedusing3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide(MTT);fluorescencedetectionofβ-secretaseactivitywasperformed;WesternBlotwasusedtomeasureβ-secretaseexpression.RESULTS:Cellviabilityunderhypoxic/hypoglycemicorhypoglycemiccultureconditionswassignificantlylessthancontrolcells(P<0.05).Underhypoxic/hypoglycemicorhypoglycemiccultureconditions,treatmentwith25μg/mLEgb761didnotaltercellviability.However,>25μg/mLEgb761inducedgreatercellviability(P<0.05).Nodifferenceswereobservedbetweenhypoxic/hypoglycemicorhypoglycemiccells(P>0.05).α-secretaseactivitywasincreasedafter12hoursinhypoxic/hypoglycemicculture(P<0.01).Therewerenosignificantdifferencesbetweenthe12-,24-,or36-hourEgb761groupsandthehypoxic/hypoglycemicgroups(P>0.05).β-secretaseactivitywasgreaterafter12,24,and36hoursinhypoxic/hypoglycemiccultureconditions,comp

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简介：Severalstudieshavedemonstratedthattheamountofbeta-amyloid(Aβ)proteininthebraincanbeloweredbydown-regulatingAβproduction,promotingAβdegradation,reducingAβoligomerizationordeposition,therebyalleviatingsymptomsofAlzheimer'sdisease.Curcuminhasbeenknowntobeaperoxisomeproliferatoractivatedreceptorgamma(PPARγ)agonistandcanobviouslyinhibitAβproductionandoligomerization.Thisstudyinvestigatedtheeffectsofcurcuminontheβ-siteAPPcleavingenzyme1(BACE1)activityandPPARγexpressioninhumanneuroblastomaSH-SY5Ycells,andvalidatedtheinhibitoryeffectsofcurcuminonAβ40/42expressioninthebrain.ResultsrevealedthatPPARγmRNAandproteinexpressioninthehumanneuroblastomaSH-SY5Ycellssignificantlyincreasedwithincreasingcurcuminconcentrationandtimecourse(P<0.05);BACE1mRNAandproteinexpressionandAβ40/42productionsignificantlydecreasedwithincreasingcurcuminconcentrationandtimecourse(P<0.05).ThechangesinPPARγandBACE1expressionduringAβproductioncouldbereversedbythePPARγantagonistGW9662.ThesefindingsindicatethatcurcuminreducedAβproductionbyactivatingPPARγexpressionandinhibitingBACE1expressioninaconcentration-andtime-dependentmanner.

简介：很多研究调查了外部煽动性的索引，包括根据痴呆的子类型的血浆cytokines和相关分子，然而并非在温和认知缺陷(媒体控制接口)。在这研究，我们使用了复合cytokine试金作为amnestic和non-amnestic与媒体控制接口subtyped在病人估计22cytokines的血浆层次，根据认知特征。当比较血浆生长因素，chemokines和cytokines的层次时，血浆单核白血球铺平趋化性的蛋白质3(MCP-3)，并且贝它神经生长因素(在这二的-NGF)组织，他们被发现比在non-amnestic媒体控制接口病人在amnestic媒体控制接口病人显著地更高级，在好久调整和性以后。这建议血浆MCP-3和-NGF可能在区分媒体控制接口的子类型是有用的。

简介：目的探讨Beta角判断替牙期与恒牙期前牙反[牙合]患者颅面矢状关系的可靠程度。方法应用X线头颅定位侧位片，比较替牙期与恒牙期前牙反[牙合]患者的Beta角、ANB角、Wits值和APDI指数的差异，并进行相关性和变异程度分析。结果替牙期与恒牙期前牙反[牙合]患者Beta角间差异有统计学意义（P〈0．05）；Beta角与ANB角、Wits值和APDI指数显著相关（P〈0．05），但变异较ANB角和Wits值小，与APDI指数接近。结论Beta角可准确评价前牙反[牙合]患者的颌骨矢状关系。

简介：最近浏览器市场可谓狼烟四起、群雄争霸、热门非凡，微软发布IE8Beta2的热浪还未消退，谷歌已经耐不住寂寞，突然重拳出击，推出谷歌浏览器（GoogleChrome），以初生牛犊不怕虎的气势向IE的垄断地位发起挑战。在浏览器领域，IE可以说是名副其实的老将，而谷歌浏览器则是不折不扣的新兵，在这场老将新兵的巅峰对决中谁将最后胜出，占据龙头老大的位置，我们且不先下结论，还是来看看它们各自有哪些特色功能，哪款浏览器更适合你吧。

简介：摘要目的评估新型冠状病毒灭活疫苗免疫人群和小鼠血清对变异株(Delta株和Beta株)的交叉中和活性。方法各取20份人群常规两剂基础免疫血清、三剂加强免疫血清和两剂小鼠免疫血清作为实验材料，采用新型冠状病毒原型株、Delta和Beta变异株3株病毒，在生物安全三级实验室中采用微量中和试验检测中和抗体。通过分析不同稀释度血清对固定剂量病毒的中和活性，计算血清阳性率和抗体几何平均滴度(geometric mean titer, GMT)，评估免疫血清的交叉中和水平。结果人免疫血清对不同变异株的阳性率均大于95%；基础免疫后，接种者血清对原型株、Delta和Beta变异株的中和抗体GMT分别为109、41和15，与原型株比较，针对Delta和Beta变异株的中和抗体GMT分别下降2.7倍和7.3倍；加强免疫后，接种者血清对原型株、Delta和Beta株的中和抗体GMT分别为446、190和86，与原型株比较，针对Delta和Beta变异株的中和抗体GMT分别下降2.3倍和5.2倍。小鼠免疫血清对不同变异株的阳性率均为100%；对原型株、Delta和Beta变异株的中和抗体GMT分别为2 037、862和408，与原型株比较，针对Delta和Beta变异株的中和抗体GMT分别下降2.4倍和5.0倍。结论新型冠状病毒灭活疫苗免疫后的人群和小鼠血清均可对Delta和Beta变异株产生一定水平的中和保护，且人群加强免疫后可产生更高水平的中和抗体和交叉中和抗体，为该疫苗的临床应用和保护效果评估提供了重要参考。

简介：美国加州Beta油田与我国辽东湾SZ36-1油田具有相似的特点。Beta油田具油稠(平均比重0.96)、埋深适中、含油井段长、储层疏松易出砂等特点。壳牌石油公司采用了防砂系统,电潜泵采油,注水保持压力以及多井槽、弯导管平台钻井等工艺措施,取得了较好的效益、笔者通过Beta油田与SZ36-1油田的对比,对开发SZ36-1油田试验区开发井网、完井工艺、采油方式以及钻井平台选型等,提出了建议.

简介：Multiplesclerosis(MS)isachronicautoimmunediseaseofthecentralnervoussystem(CNS)characterizedbycoexistingprocessesofinflammation,demyelination,axonalneurodegeneration,andgliosis.Itisthemostcommondisablingneurologicaldiseaseinyoungadulthood.Althoughautoimmuneinflammationcontributestoaxonalpathology

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简介：BACKGROUND:Ithasbeendemonstratedthattransforminggrowthfactor-β(TGF-β)andbrain-derivedneurotrophicfactor(BDNF)caninducestemcelldifferentiationintoneuron-likecells.OBJECTIVE:ToinvestigatetheefficacyofTGF-βandBDNFatinducingthedifferentiationofadultratbonemarrowstromalcells(BMSCs)intoneuron-likecells,bothincombinationoralone.DESIGN,TIMEANDSETTING:AcomparativeobservationexperimentwasperformedattheDepartmentofOrthopedics,FirstAffiliatedHospitalofLiaoningMedicalUniversitybetweenOctober2007andJanuary2008.MATERIALS:TGF-βandBDNFwerepurchasedfromSigma,USA;mouseanti-ratneuronspecificenolase,neurofilamentandglialfibrillaryacidicproteinwerepurchasedfromBeijingHMHLBiochemLtd.,China.METHODS:BMSCswereisolatedfromratsaged4weeksandincubatedwithTGF-β(1μg/L)and/orBDNF(50μg/mL).MAINOUTCOMEMEASURES:Expressionofneuron-specificenolase,neurofilamentandglialfibrillaryacidicproteinweredeterminedbyimmunocytochemistry.RESULTS:BMSCsdifferentiatedintoneuron-likecellsfollowinginductionofTGF-βandBDNF,andexpressedbothneuron-specificenolaseandneurofilament.ThepercentofpositivecellswassignificantlygreaterinthecombinationgroupthanthoseinducedwithTGF-βorBDNFalone(P<0.01).CONCLUSION:TreatmentofBMSCswithacombinationofTGF-βandBDNFinduceddifferentiationintoneuron-likecells,withtheinductionbeingsignificantlygreaterthanwithTGF-βorBDNFalone.

简介：1-methyl-4-phenylpyridiniumion(MPP+)inducesendoplasmicreticulumstressandactivatescaspase-12inPC12cells,leadingtoneuronalapoptosis.However,theunderlyingmolecularmechanismremainsunknown.Thepresentstudyinvestigatedtheregulatoryeffectsofnervegrowthfactor(Aktactivator)andlithiumchloride(glycogensynthasekinase-3βinhibitor)ontheendoplasmicreticulumstresssignalingpathway.TheresultsrevealedthatMPP+inducedexpressionofBipandC/EBPhomologousprotein.TheupregulationofBipandC/EBPhomologousprotein,aswellasthedecreasedpro-caspase-12levelinducedbyMPP+wereinhibitedbypretreatmentofthenervegrowthfactororlithiumchloride.Theseresultssuggestthatthephosphatidylinositol3kinase-Akt-glycogensynthasekinase-3βpathwayisinvolvedinMPP+-inducedendoplasmicreticulumstress.

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