简介:Anenvironmentallyfriendlyprecursor,adenosine,hasbeenusedasadualsourceofCandNtosynthesizenitrogen-dopedcarboncatalystwith/withoutFe.Ahydrothermalcarbonizationmethodhasbeenusedandwateristhecarbonizationmedia.Themorphologyofsampleswith/withoutFecomponenthasbeencomparedbyHRTEM,andtheresultshowsthatFecanpromotethegraphitizationofcarbon.Furtherelectro-chemicaltestshowsthattheoxygenreductionreaction(ORR)catalyticactivityofFe-containingsample(C–FeN)ismuchhigherthanthatoftheFe-freesample(C–N).Additionally,theintermediatesofC–FeNformedduringeachsyntheticprocedurehavebeenthoroughlycharacterizedbymultiplemethods,andthefunctionofeachprocedurehasbeendiscussed.TheC–FeNsampleexhibitshighelectro-catalyticstabilityandsuperiorelectro-catalyticactivitytowardORRinalkalinemedia,withitshalf-wavepotential20mVlowerthanthatofcommercialPt/C(40wt%).Itisfurtherincorporatedintoalkalinepolymerelectrolytefuelcell(APEFC)asthecathodematerialandledtoapowerdensityof100mW/cm~2.
简介:AIM:Toinvestigatetheeffectsofhydrogen-richsaline(HRS)onmicrogliaactivationandSirtuintype1(Sirt1)inratswithN-methyl-N-nitrosourea(MNU)-inducedretinitispigmentosa(RP).METHODS:Ratsweredividedintonorm(N)group,model(M)groupandHRS(H)group.RatsinMandHgroupsweregivensalineandHRSrespectivelypriortoandafteradministrationofMNU.Atoneday(d1)andd3afterwards,electroretinogramandhistologicalexaminationwereperformedtoconfirmtheeffectsofHRSonretinalfunctionandstructureofMNU-inducedRP.Immunofluorescencestainingofanti-ionizedcalcium-bindingadaptermolecule1(Iba1),amakerofmicrogliacells,wasperformed,withquantitativereal-timepolymerasechainreaction(qRT-PCR)foritsmRNAquantification.Moreover,Sirt1mRNAandproteinexpressionintheretinasweredetectedbyWesternblotandqRT-PCR.RESULTS:HRSpreservedtheretinalfunctionandmitigatedthereductionofphotoreceptordegenerationinMNU-treatedretinas.ThepresenceofmicrogliacellswassomewhatmoreobviousinHgroupthanthatinMgroupatd1.HRSsuppressedthefurtheractivationofmicrogliacells,withthenumberofmicrogliacellslessthanthatofMgroupatd3.ResultsofqRT-PCRofIba1wereconsistentwiththoseofimmunofluorescencestaining,withthemRNAexpressionofIba1inHgroupmoreintensivethanthatofMgroupatd1(P<0.05),whilelessthanthatofMgroupatd3(P<0.05).Furthermore,theSirt1mRNAandproteinexpressiondecreasedafterMNUadministration,whileHRSmitigatedtheMNU-induceddownregulationofSirt1.CONCLUSION:HRScaneffectivelykeepmicrogliaactivationinducedbyMNUtoanappropriateextent,whileupregulateSirt1inMNU-inducedRP.
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简介:应用密度泛函理论中的ω-B97XD/6-311+G(d,p)方法,对甲湛分子团簇[CH2O]n(n=1~4)的空间结构进行了优化,得到了这些团簇的基态结构,并对其红外光谱,核磁共振谱的性质进行了研究.结果表明,当甲醛分子构成稳定的多分子团簇时,团簇中的每个分子仍然为平面结构,分子间将形成氢键,并且团簇中的各个分子共面.与单分子甲醛相比,多分子团簇的红外光谱,会出现许多与分子间氢键振动有关的新的吸收峰.当甲醛分子形成团簇时,13C核和17O核的核磁共振谱线会发生劈裂现象,这与电荷分布的对称性的破缺有关;而1H的核磁共振谱中将会出现新的条纹,这是由分子间的氢键的形成引起的.本文的研究可为甲醛团簇的识别、检测及性质研究提供理论依据.