简介:TheunimolccularreactionsofammoniaoxideH3NO,isomerizationanddehydrogenation,areinvestigatedbyabinitioMOcalculationswiththe4-31Gbasisset.Thegeometriesandenergiesofthereactant,transitionstatesandproductshavebeendeterminedonthesingletpotentialenergysur-face.Thereactionergodographyalongtheintrinsicreactioncoordinate(IRC)forthetworeactionshavebeenperformed.ThevibrationalfrequencycorrelationdiagramofthetworeactionsareanalyzedalongtheIRC.
简介:IntroductionIn1963,MoorA.M.[1]firstlyreportedthephosphateefect,i.e.,intheUVirradiation(253.7nm)ofaqueoussolutionsof4-amino-2-...
简介:Anewmacrocycliccompoundhasbeensynthesizedbycondensationofpyridine-1-oxide-2,6-dialdehydewithdiethylenetria-mine.Theself-assemlybehaviourswerestudiedbyX-raydiffraction.Theresultsshowthattheself-assemblywerecontrolledbyintermolecularhydrogenbondsandπ-πstackingeffects.
简介:钴hexacyanoferrate(CoHCF)nanoparticle(尺寸ca。60nm)化学上修改的电极(CME)被制作,在这nanosizedCoHCFCME的血红素(Hb)的电气化学的行为被学习。与一个赤裸的玻璃质的碳电极(GCE)和以一种传统的方式的一般CoHCFCMEelectrodeposited比较,现在的nanosizedCoHCFCME高效地与相对高的敏感,稳定性,和longlife为Hb执行了electrocatalytic减小。与液体层析(LC)结合了,nanosizedCoHCFCME在确定的流动注射被用作Hb的电气化学的察觉者分析电气化学的决心(FIA-ECD)系统。山峰水流是在从2.5楳?景映牯業?捡摩映潲?慣'R湯搠潩楸敤愠摮栠摹潲敧?獵湩?的范围的集中的线性功能?楳楬慣椠浭扯汩穩摥爠瑵敨楮浵挠瑡污獹?獡瀠敲畣獲牯栠獡戠敥?瑳摵敩?湩搠晩敦敲瑮爠慥瑣潩?潣摮瑩潩獮?桔?敲?瑬?敲敶污摥琠慨?桴?佔?琨牵?癯牥映敲畱湥祣?景?佃?愠档敩敶????栠?漠?浩潭楢楬敺?畲桴湥畩?慣慴祬瑳渠慥?桴?牣瑩捩污瀠敲獳牵?潰湩?景??眠瑩??瀠敲獳牵?景???慐?敲捡楴湯琠浥数慲畴敲漠吗????
简介:AnovelfuUerene-acrylamidecopolymerwassynthesizedviaradicalpolymerization.Itissolubleinpolarsolventssuchaswater,dimethylsulfoxideetc.TheproductwascharacterizedbyFTIR,UV-VisandGPC.TEManalysisshowsthattheaverageparticlediameterisabout46nm.Four-balltestsshowthattheadditionofacertainconcentrationofthefullerenecopolymertobasestock(2wt%triethanolamineand0.5wt%OPZaqueoussolution)caneffectivelyraisetheload-carryingcapacity(PBvalue)andtheantiwearability.SEManalysisshowsthattheadditionresultsinreducingdiameterofwearscaranddecreasingwear.
简介:Theinteractionofbromothymolblue(BB)withhumanserumalbumin(HSA)wasstudiedbyelectrochemicaltechniquesandasensitivemethodforproteinsassaywasdeveloped.WhenBBinteractedwithHSA,thevoltammetricpeakcurrentvalueofBBdecreasedlinearlywiththeconcentrationofHSAinarangeof1.0―40.0mg/L,andthepeakpotentialshiftednegatively.Basedontheresults,asensitiveassaymethodforproteins,suchasHSA,bovineserumalbumin(BSA),andeggalbuminetc.wasestablished.ThismethodwasfurtherappliedtodeterminingtheHSAinhealthyhumanbloodsamples,andtheresultsarenotsignificantlydifferentfromthoseobtainedbytheclassicCoomassieBrilliantBlueG-250spectrophotometicmethod.Thedetectingconditionsofthismethodwereoptimizedandtheinteractionmechanismwasdiscussed.Theresultsshowthattheelectrochemicalparameters(formalpotentialE0,standardrateconstantoftheelectrodereactionks,parameterofkineticnα)ofBBhavenoobviouschangesbeforeandaftertheinteraction,whichindicatethatBBcaninteractwithHSA,forminganelectrochemicalnon-activecomplex.Theequilibriumconstant(βs)andthebindingratio(m)forthiscomplexwerecalculated.Themis4andβsis1.41×1019.Thismethodisfast,simple,highlysensitive,andhasgoodselectivity,whichcanbeusedinclinicalmeasurements.
简介:Arapidandeffectivemethod,solidphaseextractioncoupledwithhighperformanceliquidchromatography(SPE-HPLC),wasappliedtotheseparationandanalysisofginsenosides.WatersOASISHLBwasusedforconcentratingandpurifyingsamplesandAlltimaC_(18)(53mm×7mm,3μm)chromatographycolumnwasusedforseparatingginsenosideRg_1,Re,Rb_1,Rc,Rb_2andRd.Theseginsenosideswereanalyzedwithin20mininourgradientelutionprocessandtheequilibriumtimeofthechromatographycolumncostonly5min.Moreover,therewasnoobviousbaselinedriftinourexperiment.Thismethodwasusedtoanalyzethecontentsofginsenosidesindifferentginsengproductsforqualitycontrol.Fourginsengproductswerestudied,includingtwokindsofcapsules,onekindoftabletandonekindofinjection.Theresultsshowthatthemethoddevelopedinthispaperhadgoodaccuracy,linearityandprecision.Therefore,thismethodcouldbeappliedinqualitycontrolofginsengproducts.
简介:Thedye-dopedsilicananoparticlescanbeusedasnanobiosensorsthatareabletorecognizeanddetectspecificDNAsequence.Inthispaper,sphericalnanosizedluminol/SiO2compositeparticleshavebeensynthesizedwithreversemicellsviahydrolysisoftetraethylorthosilicate(TEOS)inthemicroemulsion.ThenanoparticlesweremodifiedwithchitosanandusedtolabelDNA,formingtheDNAprobewhichwasusedtohybridizewithtargetDNAimmobilizedonaPPymodifiedPtelectrode.Thehybridizationeventswereevaluatedbyelectrogeneratedchemiluminescence(ECL)measurementsandonlythecomplementarysequencecouldformadouble-strandedDNA(dsDNA)withDNAprobeandgivestrongECLsignals.Athreebasemismatchsequenceandanon-complementarysequencehadalmostnegligibleresponses.Duetothelargenumberofluminolmoleculesinsidesilicananoparticles,theassayallowsdetectionatlevelsaslowas2.0×10^-12mol/LofthetargetDNA.TheintensityofECLwaslinearlyrelatedtotheconcentrationofthecomplementarysequenceintherangeof5.0×10^-12—1.0×10^-9mol/L.
简介:Thymopentinderivative(septapeptide)waspreparedbymeansofthesolid-phasepeptidesynthesismethodinwhichstepwiseandsegmentcondensationswereinvolved.ThestructuresofthekeyintermediateandtargetmoleculewereconfirmedbyESI-MS,elementaryanalysis,IR,1HNMRand13CNMRspectrometriesinourexperiments.Inthisstudy,theauthorsfoundthatboththymopentinderivetive(septapeptide)andthymopentincouldpromoteTcellproliferationandincreaseofE-rosefomationcells.
简介:ChiralRu-BsDPEN,(1R,2R)-N-p-benzenesulfonyl-1,2-diphenylethylenediamine,catalysthasbeenimmobilizedonamesoporousmolecularsieveofMCM-41typesuccessfully.Ahybridmesoporousmolecularsievewassynthesizedusingaprecursorbearingbenzenegroup,whichinorganosilicaweresulfonylatedandreactedwith(1R,2R)-l,2-diphenylethylenediamineand[RuC1E(p-cymene)]2successivelytoaffordimmobilizedcatalyst.TheBrunauer-Emmett-Teller(BET)surfaceareaandBarrett-Joyner-Halenda(BJH)poresizedecreasedafterimmobilizationofcatalystontothemesoporousmaterial.Enantioselectivetransferhydrogenationofketonescatalyzedbyimmobilizedcatalystshowedthehighestyieldof22.36%ande.e.valueof31.47%byusingacetophenoneassubstratewhenreactiontimewas48and16hrespectively.
简介:Introduction PanaxquinquefoliumL.BelongstothePanaxgenusoftheAraliaceae.ItoriginatesinAmericaandCanada.Itsroots,afamousandexpensivetraditionalChinesemedicinalmaterial,havebeenstudiedcontinuallysinceitssuccessfulcultivationinChinainthe1970s.Inrecentyearsthedevelopmentandutilizationresearchesofitsaerialpart,whichwasabandonedinthepast,havebeenconducted.Theconstituentstudiesontheleaves,stemsandfruitshavebeenreported.Butnoinformationabouttheflowerbudshasbeenfoundinliteratures.TheauthorshavereportedastudyaboutthechemicalconstituentsoftheflowerbudsoftheP.QuinquefoliumcultivatedinChina.Inthepresentworktwoflavonoids(namelykaempferolandpanasenoside)intheflowerbudsoftheP.QuinquefuliumcultivatedinChinawereextracted,isolated,andidentified.Sincethemedicinalmaterialswereprocessedwithanunusualtreatment,thecontentdeterminationofthemonomericandtotalflavonoidinthedifferentpartswereperformedcorrectlywiththemethodsofdual-wavelengthTLC-scan,andUV-absorption,anditwasdiscoveredthattherewereflavonoidsintherootsandfruitsoftheP.Quinquefolium.ThescientificbasiswasprovidedfortheutilizationoftheflowerbudsandotherpartsresourcesoftheP.
简介:Apyridoxal-basedchemosensorwassynthesizedbyreactinghydrazinehydrateandpyridoxalhydrochlorideinethanolandcharacterizedbyNMRandESI-MS.Theopticalpropertiesofthecompoundwereinvestigatedinamethanol:HEPESsolution.ThecompounddisplayedselectivityforCu2+,asevidencedbyacolorlesstoyellowcolorchange,whichwascharacterizedusingUV–visspectroscopy.ThefluorescenceofthecompoundcanbequenchedonlybyCu2+,accompanyingbyacolorchangefrombluetocolorless.Furthermore,itcanbeusedinbioimaging.
简介:Thepaperdealswiththedegradationoftheorganiccompoundsinthecokeplantwastewaterbythecombinedprocessofultrasonicirradiationandactivatedsludge.Theinfluencefactorsoftheultrasonicdegradationeffectsuchasairatmosphere,initialconcentration,ultrasonicpowerdensityandthecategoryandconsumptionofcatalystwereinvestigated.Awaterqualitymodelwasusedtoexplainthedegradationofdifferentkindsoforganiccompoundsinthecokeplantwastewaterbyultrasonicirradiation.Afterthewastewaterwastreatedbythecombinedprocessofultrasonicirradiationandactivatedsludge,theCODdegradationefficiencywas95.74%,whichis63.49%higherthanthatbytheprocessofactivatedsludgealone.
简介:AnovelacrylicmonomerbearingaromaticetherealitygroupN-(p-phenoxy-phenyl)methacrylamide(MAPOA)wassynthesizedandpolymerized.ThefluorescencespectraofMAPOAanditspolymerwerestudied,showingthatthepolymerdisplaysastrongerfluorescencethanitsmonomeratthesamechromophoreconcentration.ThefluorescenceofP(MAPOA)wasquenchedbyaddingelectrondeficiencymonomerssuchasMMA,ANetc..Itisanotherexampleofshowingthe"fluorescencestructuralself-quenchingeffect"aswereportedpreviously,fromwhichitisdemonstratedagainthatthisphenomenonisnotanaccidentalonebutacommoneffectforacrylicmonomersbearingelecton-donatingchromophores.ThephotopolymerizationofANsensitizedbyMAPOAandP(MAPOA)wasstudied.Thekineticequationofthepolymerizationwasobtainedandrepresentedasfollows:Rp∝[MAPOA]0.38×[AN]0.78,Rp∝[P(MAPOA)]0.33×[AN]0.71TheoverallactivationenergiesweredeterminedtobeEa=24.22kJ/mol(MAPOA)andEa=26.31kJ/mol[P(MAPOA)]respectively.ThefluorescenceanalysisoftheresultedP(AN)showedthatthesensitizeralsoenteredintotheP(AN)chains.AmechanismoftheformationofachargetransfercomplexandfreeradicalinitiationwassuggestedforthephotopolymerizationofANsensitizedbyMAPOAandP(MAPOA).
简介:Micelles,microemulsions.vesicles,etc.,areorganicmicroheterogeneousmedia.Useofthesemediainanalyticalreactionsfordevelopingnewkinetic-baseddeterminationsorimprovingpreviouslyestablishedkineticmethodshasbeenreported'2.Inrecentyears,amixedmicellarmediumc...
简介:Thecellulosetris(4-methylbenzoate)hasbeensynthesisedbythecatalyticmethodandwassupportedatGasChromQ.Theabsorptioncapabilityofcellulosetris(4-methylbenzoate)usedasagaschromatographicstationaryphasewascharacterizedbychromatographicmethodandtheClausius-Clapeyronequation.However,n-alcohols(C1-C8)weresuccessfullyseparatedonthecolumnpackedwithGasChromQcoatedwithcellullosetris(4-methylbenzoate).