简介:目的:研究冬凌草甲素诱导食管癌细胞凋亡的过程中细胞内[Ca2+]和线粒体结构、功能的变化。方法:采用倒置相差显微镜观察细胞形态;末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法检测细胞凋亡;透射电镜法观察线粒体超微结构改变;罗丹明123荧光探针标记流式细胞仪检测和分析线粒体跨膜电位(△Ψm);激光扫描共聚焦显微镜测定细胞内[Ca2+]浓度。结果:冬凌草甲素剂量和时间依赖性的抑制SHEEC细胞生长;32μg/ml冬凌草甲素作用2h后电镜下BGC-823细胞线粒体增殖,4h后线粒体肿胀空泡化、内部结构消失,8h后细胞核染色质成块状边集,细胞凋亡;冬凌草甲素作用24h后,代表线粒体膜电位的Rho123荧光强度降低;经冬凌草甲素刺激后SHEEC细胞内[Ca2+]水平显著升高。结论:在冬凌草甲素诱导SHEEC细胞凋亡过程中,SHEEC细胞线粒体有明显的形态和功能改变伴随线粒体△Ψm降低,同时SHEEC细胞内[Ca2+]水平显著升高,提示线粒体改变和细胞内[Ca2+]升高可能是冬凌草甲素诱导食管癌细胞凋亡过程的重要环节。
简介:Atomized,pre-alloyedTi—24Nb—4Zr—7.9Sn(wt%)powderwasusedtofabricatesolid,prototypecomponentsbyelectronbeammelting(EBM).Vickersmicroindentationhardnessvalueswereobservedtoaverage2GPafortheprecursorpowderand2.5GPaforthesolid,EBM-fabricatedproducts.Thepowderandsolidproductmicrostructureswereexaminedbyopticalandelectronmicroscopy.X-raydiffractionanalysesshowedthattheyhadbccβ-phasemicrostructure.However,itwasfoundbytransmissionelectronmicroscopythattheEBM-fabricatedproducthadplatemorphologywithspace~100—200nm.Althoughthecorrespondingselectedareadiffractionpatternscanbeindexedbyβ-phaseplusα'-martensitewithorthorhombiccrystalstructure,thedark-fieldanalysesfailedtoobservethea'-martensite.Suchphenomenonwasalsofoundindeformedgummetalsandexplainedbystress-induceddiffusionscatteringduetophononsoftening.
简介:AsimplespectrophotometricassayofH2O2andglucoseusingAgnanoparticleshasbeencarriedout.RelyingonthesynergisticeffectofH2O2reductionandultraviolet(UV)irradiation,Agnanoparticleswithenhancedabsorptionsignalsweresynthesized.H2O2servedasareducingagentintheAgnanoparticlesformationinwhichAg+wasreducedtoAg0byO2àgeneratedviathedecompositionofH2O2inalkalinemedia.Ontheotherhand,photoreductionofAg+toAg0underUVirradiationsalsocontributedtothenanoparticlesformation.ThesynthesizednanoparticleswerecharacterizedbyTEM,XPS,andXRD.TheproposedmethodcoulddetermineH2O2withconcentrationsrangingfrom5.010à7to6.010à5mol/L.Thedetectionlimitwasestimatedtobe2.010à7mol/L.SincetheconversionofglucosetogluconicacidcatalyzedbyglucoseoxidasewascompaniedwiththeformationofH2O2,thesensingprotocolhasbeensuccessfullyutilizedforthedeterminationofglucoseinhumanbloodsamples.Theresultswereingoodagreementwiththosedeterminedbyalocalhospital.Thiscolorimetricsensorthusholdsgreatpromisesinclinicalapplications.
简介:TiO2@ZrO2@Y2O3:有coremultishell结构的Eu3+合成粒子通过layer-by-layer(LBL)的联合被综合自己组装方法和一个solgel过程。获得的样品与扫描电子被描绘显微镜学(SEM),传播电子显微镜学(TEM),X光检查光电子光谱学(XPS),X光检查衍射(XRD),和荧光spectrophotometry。结果证明合成粒子有coremultishell结构,球形的形态学,和狭窄的尺寸分布。TiO2核心上的ZrO2层的存在能有效地阻止在TiO2核心和Y2O3壳之间的反应;为在在TiO2@ZrO2@Y2O3的TiO2核心和Y2O3壳之间的反应的温度:Eucoremultishell黄磷能被300提高