简介:目的探讨噪声暴露前后锰超氧化物歧化酶(Mn-SOD)在大鼠螺旋神经节不同区域表达分布的差异与噪声性聋高频听力易损性的相关性.方法SD大鼠随机分为两组:实验组给予白噪声115dB2h3d造模,不处理者为对照组.ABR测听分析噪声损伤情况;免疫组织化学染色法分析噪声暴露前后Mn-SOD在螺旋神经节不同区域的表达水平;黄嘌呤氧化酶法检测Mn-SOD在螺旋神经节不同区域的活性及变化趋势.结果①ABR:大鼠噪声暴露后与暴露前相比,4、8、16、20、32kHzABR阈值均明显上移,以高频听阈变化更为显著;②免疫组织化学染色:在正常情况下,顶部螺旋神经节的Mn-SOD的阳性表达较底部明显;噪声暴露后,Mn-SOD在螺旋神经节的表达较对照组相应部位均显著增高;且顶部较底部的表达增强更为显著;③Mn-SOD活性测定:在正常情况下,顶部螺旋神经节的Mn-SOD活性与底部相比无统计学差异,噪声暴露后,Mn-SOD活性较对照组相应部位均有下降,且底部较顶部更为显著.结论Mn-SOD在螺旋神经节顶、底部区域的表达分布差异,可能是噪声性聋高频听力易损性的分子机制之一.
简介:Humanextracellularsuperoxidedismutase(hEC-SOD)isasecretedtetramericproteininvolvedintheprotectionofahumanbodyfromoxygenfreeradicals.Itsthree-dimensionalstructurehasnotbeenconfirmed,hEC-SODcouldn′tbeexpressedinE.coll.Weconstructedahybridenzyme,whichcomprisestheNterminalandC-terminaldomainsfromhEC-SOD,fusedittohumanCu,Zn-SOD.ThehybridenzymeisexpressedsuccessfullyinE.coli.Further,weanalyzedtheexpressionofhEC-SODinE.colibymRNAdifferentialdisplaying.
简介:TheballmillingofFe-24MnandFe-24Mn-6Simixedpowdershasbeenperformedbythehighenergyballmillingtechnique.ByemployingX-raydiffractionandMoessbauermeasurements.Theccmpositionevolutionduringthemillingprocesshasbeeninvestigated.TheresultsindicatetheformationofparamagneticFe-MnorFe-Mn-Sialloyswithametastablefccphaseasfinalproducts.whichimplythattheFeandMnproceedaco-diffusionmeenanismthroughthesurfaceoffragmentedpowders.Thethermalstabilityandcompositionevolutionoftheas-milledalloyswerediscussedcomparingwiththebulkalloy,.
简介:TheSOD-likeactivityoffiveCu(Ⅱ)complexes[Cu(HSal)_2·EtOH,Cu(Gly)_2,Cu(Lys)_2,Cu(His)_2,Cu(Try)_2]havebeenstudiedbyusingcytochromeCmethod,aswellaschemilumine-scenceandESRtechnique.Thefoursurfactants(CTAB,SDS,TritonX-100andTween20)werepurifiedandtheircriticalmiceileconcentration(CMC)inphosphatebuffer(pH=7.4)wasmea-sured.TheeffectsoffoursurfactantsonO_2~-havebeeninvestigated.Theco-operativeeffectsof
简介:摘要:近年来,SOD在农业和医药等多个领域都展现出了巨大的应用价值和开发前景。对SOD的功能、抗氧化机制、类型以及生产方式等进行了概述,并重点综述了SOD在食品工业上的应用情况及发展潜力。
简介:ThestabilityconstantsofthebinarycomplexesofMn2+withnicotinamide(NA)weredeterminedfrompotentiometricpHtitrationsdataat15.0,25.0and35.0oCandI=0.1,0.2,0.4molL-1(NaClO4).Theformationofbinary1:1,1:2NA-Mncomplexesatthreedifferenttemperaturesandtheinfluenceofthreedifferentionicstrengthontheirstabilitywerereported.Thethermodynamicparameters(△Gof,△Sof,△Hof)forthecomplexformationreactionwereestimatedfromstabilityconstantatdifferenttemperatures.
简介:张力爬精细的Fe-Mn二进制合金containing0.42-1.21wt.%Mn的行为从房间温度在温度范围被调查了到475Kunder10-50MPa。张力的测试以紧张率在uniaxail负担下面以经常的小标题速度被执行10(-4)s(-1)。压力代表和激活精力决心澄清变丑机制。稳定的状态的获得的变化爬关于为Fe-Mn二进制合金的应用压力的率在大约20MPa展出二不同政体,显示一个可能的变化在爬机制。平均压力代表是约2.2,它是在合金滑动的谷物boundry的一个特征。为塑料流动的激活精力从135~92kJ/mol变化,取决于Mn内容。
简介:TheSOD-likeactivitiesofcoppersalicylateencapsulatedinneutralpositivelyandnegativelychargedliposomeswerestudiedwithcytochromecmethod.TheresultsshowedthattheSOD-likeactivityofcoppersalicylateencapsulatedinneutralliposomeswasenhancedover3timesmorethanthatofcoppersalicylateinaqueoussolution.However,theactivitydecreasedforcoppersalicylateencapsulatedinpositivelyandnegativelychargedliposomes.Itwasalsofoundthatatexperimentalconcentrationstherewasnoregularityforthechangeofactivityofcoppersalicylateencapsulatedinnegativelychargedliposomes,andcoppersalicylateencapsulatedinliposomeswithmorenegativechargescouldpromotethedismutationofsuperoxideanionfreeradicals,however,socouldcoppersalicylateencapsulatedinliposomeswithfewernegativechargesonlyinlowerconcentrations.