简介:采用非极性大孔树脂(D-101)从酸枣仁醇提物中分离酸枣仁皂苷和苷元,采用超声强化、不同温度真空干燥和甲醇中浸渍等方法预处理树脂,并对其分离纯化行为进行分析对比,运用SEM,BET和DSC等手段表征树脂特征,采用分光光度法和质谱法等手段确定提取混合物的成分及含量,并结合量子化学方法计算确定其绝对构型.结果表明,不同条件的操作处理主要通过改变树脂的孔径和含水量影响树脂分离纯化酸枣仁皂苷和苷元的纯度,同时受皂苷和苷元的空间构象影响,含水21%的树脂在甲醇溶液中175W下超声30min预处理树脂分离纯化酸枣仁醇提物的皂苷和苷元的总含量达43%以上.
简介:密度功能的计算被执行了比较地调查Au(I)的二条可能的小径有炔属羟的-ketoesters的催化Conia-ene反应。我们的研究发现在trifluoromethanesulfonate(TfO)的帮助下面,-ketoester是很可能为II建模经历到isomerize进它的enol形式,TfO通过一个6成员戒指转变状态在起一个质子转移作用。到炔属羟三元组契约的Au(I)催化剂的协作能提高eletrophilic能力和炔属羟一半的反应活动,它在炔属羟一半上触发enol一半的亲核的增加给vinyl-Au中介。这cycloisomerizaion步是由有56.0kJ/mol的一个精力障碍的21.3kJ/mol的exothermal。在整个催化过程,vinyl-Au的protonation是几乎自发的,并且enol的形成是限制率的步。enol的产生和炔属羟上的Au(I)催化剂的激活是Conia-ene反应能处于温和状况发生的关键原因。Au(I)催化的这些计算支持有炔属羟的-ketoesters的Conia-ene反应通过2由Toste建议了的小径。
简介:CardiactroponinI(cTnI)wasseparatedandpurifiedfromhumanleftventriculartissuebyaffinitychromatographicmethodandusedtoimmunizeBalb/cmicebyintraperitonealinjectionandfourhybridomacelllines,whichsecretedmonoclonalantibody(mAb)againsthumancTnI,wereobtainedbycellfusion,identificationandcloningtwice.ThreemAbs(9F5,2F11,8C12)wereproducedfromtheascitesofBalb/cmiceinjectedintraperitoneallythehybridomacellsandcharacterizedbymeansofasurfaceplasmonresonance(SPR)biosensor.AnoptimalandspecificsensingmembranefortroponinIwaspreparedwithstaphylococcalproteinA(SPA)astheintermediatelayerandmAbagainsthumancTnIasthecaptureantibody.Onthebasisofthesensingmembrane,twomodesofoperationoftheSPRbiosensorweredeveloped,i.e.,adirectdetectionofantigen-antibodyaffinityandasandwichassay.Inthesandwichassaydetectionmode,themAbscompetitionwasmeasuredbymonitoringwhetherthesecondaryantibodyhadbeenattachedtothecTnIalreadycapturedbythefirstantibodyonthesensorsurface.TheSPRbiosensorwasshowntobeabletodirectlydetecttheantigen-antibodyaffinityandtheorderoftheaffinitywasfoundtobe9F5>2F11>8C12.Inthesandwichdetectionmode,itwasfoundthatthedifferentepitopesonthecTnImoleculeswererecognizedbythethreemAbsrespectively,buttheasymmetricalcompetitionwasshownbetween2F11and8C12andnocompetitionwasfoundbetween9F5and2F11or8c12.Basedontheseresults,adoublemonoclonalsandwichimmunoassayforcTnIwasdevelopedbyusingtheoptimalantibodypairof9F5and2F11andtheSPRbiosensorwithSPAsubstratemembrane,whichshowedanexcellentsensitivityof0.8μg/LforboththebufferandtheserumsamplescomparedwiththedirectdetectionofcTnIforthebufferwiththelowestdetectionlimitof4μg/LandconventionalELISAwiththesensitivityof1.9μg/L.
简介:Thestrueturaleffectoftheconjugativesystem(C)withcarbonyl-iminobridgeshasbeenstudied.Theresultsshowthat:Intheconjugatedsystem(C),thereisnoelectronicabsorptionpeakattributabletothewholesystem,buttherearethreeπ-π*bandseachntwhichdisplayschacactecisticsofitsownindependently.Theseindicatethatthetwobridges-carbonyl-and-imino-canblockthetlanSmlSSionoftheconjngativepolarizationofthewholesystem,soastoformthreesegments,thisisverifiedbymeansofchemicalsynthesisanddegradation.
简介:运用电化学循环伏安和石英晶体微天平研究了1,4-丁二醇(1,4-BDL)在Pt电极及以Sb和S吸附原子修饰的Pt(Pt/Sbad和Pt/Sad)电极上的吸附和氧化过程.结果表明,1,4-丁二醇的氧化与电极表面氧物种有着极其密切的关系,表面质量变化提供了吸附原子电催化作用的新数据.Pt电极表面Sb吸附原子能在较低的电位下吸附氧,可显著提高1,4-丁二醇电催化氧化活性.与Pt电极相比,1,4-丁二醇在饱和吸附Sb原子的Pt电极上氧化的峰电位负移了0.20V,峰电流增加了1.5倍.相反,Pt电极表面S吸附原子的氧化会消耗表面氧物种,饱和吸附的S原子抑制了1,4-丁二醇的氧化.
简介:Understeady-stateconditions,thegeneralcurrentsofEEreactionsatdisk,hemisphericalandsphericalmicroelectrodesarederived.Fromtheseequations,someelectrodereactionparameterscanbeverysimplyobtained.