简介:Prestinhasbeenidentifiedasamotorproteinresponsibleforouterhaircell(OHC)electromotilityandisexpressedontheOHCsurface.PreviousstudiesrevealedthatOHCelectromotilityanditsassociatednonlinearcapacitanceweremainlylocatedattheOHClateralwallandabsentattheapicalcuticularplateandthebasalnucleusregion.ImmunofluorescentstainingforprestinalsofailedtodemonstrateprestinexpressionattheOHCbasalendsinwhole-mountpreparationoftheorganofCorti.However,therelacksadefinitivedemonstrationofthepatternofprestindistribution.TheOHClateralwallhasatrilaminateorganizationandiscomposedoftheplasmamembrane,corticallattice,andsubsurfacecisternae.Inthisstudy,thelocationofprestinproteinsindissociatedOHCswasexaminedusingimmunofluorescentstainingandconfocalmicroscopy.Wefoundthatprestinwasuniformlyexpressedonthebasolateralsurface,includingthebasalpole.Nostainingwasseenonthecuticularplateandstereocilia.Whenco-stainedwithamembranemarkerdi-8-ANEPPS,prestin-labelingwasfoundtobeintheouterlayeroftheOHClateralwall.Afterseparatingtheplasmamembranefromtheunderlyingsubsurfacecisternaeusingahypotonicextracellularsolution,prestin-labelingwasfoundtobeintheplasmamembrane,notthesubsurfacecisternae.ThedatashowthatprestinisexpressedintheplasmamembraneontheentireOHCbasolateralsurface.
简介:INNERANDOUTERSTRUCTURESOFTROPICALCYCLONEⅡ.BAROCLINICMODEL¥LiuShikuoandLiuShida刘式适,刘式达(DepartmentofGeophysics,PekingUniversity...
简介:LetH1andH2beseparableHilbertspaces,andB(H1,H2)allofboundedlinearoperatorsfromH1intoH2.Inthisnote,weprovethefollowingtheorem:foranypositiveintegerNandT∈B(H1,H2)withaclosedrange,thereexistsanouterinverseT#NwithfiniterankNsuchthatT+y=liraT#Nyforanyy∈H2,whereT+N→∞denotestheMoore-PenroseinverseofT.ThuscomputingT+isreducedtocomputingouterinversesT#NwithfiniterankN.Moreover,becauseofthestabilityofboundedouterinverseofaT∈B(H1,H2),thisisveryuseful.
简介:Cochlearouterhaircells(OHCs)areinvolvedinamechanicalfeedbackloopinwhichthefastsomaticmotilityofOHCsisrequiredforcochlearamplification.Alternatively,amplificationisthoughttoarisefromactivehairbundlemovementsobservedinnon-mammalianhaircells.Wemeasuredthevoltage-evokedhairbundlemotionsinthegerbilcochleatodetermineifsuchmovementsarealsopresentinmammalianOHCs.TheOHCsdisplayedalargehairbundlemovementthatwasnotbasedonmechanotransducerchannelsbutbasedonsomaticmotility.Significantly,bundlemovementswereabletogenerateradialmotionofthetectorialmembraneinsitu.Thisresultimpliesthatthemotility-associatedhairbundlemotionmaybepartofthecochlearamplifier.
简介:Objective:Toconstructarecombinantplasmidcontainingtheoutermembraneprotein2(Omp2)geneofChlamydiatrachomatisandexpressOmp2inE.coli.Methods:Theomp2geneofC.trachomatisserovarDwasclonedintopQE30vectorfollowingPCRamplificationfromgenomicDNA.E.coliM15transformantswereinducedtoexpressthefusionproteinbyIPTGandtheproductwasidentifiedbySDS-PAGEandWesternblot.Results:ConfirmedbyenzymecleavageanalysisandDNAsequencing,acorrectrecombinantplasmidpQE30/omp2wasconstructed.Thefusionproteinfromthetransformantswasapproximately60kDainsizeinSDS-PAGEanalysis,whichcouldspeciallyreactwithanti-6×HismousemonoclonalIgGantibodies.Conclusion:WesuccessfullyexpressedOmp2inE.coilM15,providinganefficientandsimplesystemforassayingtheimmunologicalpropertiesofOmp2.
简介:ObjectiveToreportuseoftheVibrantSoundbridge(VSB)inpatientswithcongenitaldeformationofthemiddleandouterearsandinvestigateitsutilityinthispatientpopulation.MethodFourpatientswithcongenitaldeformationofmiddleandouterearsunderwentVSBimplantation.Allweremale(aged3-18years,average13.5years)andoperatedontheleftside.Malformationwasbilateralin3patientsandunilateralin1patient.Surgicaltechniquesweremodifiedtoaccommodateeachpatient’suniqueconditionsandneeds.Theimplantsitewasapproachedviathefacialrecessin3patientsandthrougharetro-facialnerveroutein1patient.TheVSBimplantwasconnectedtoeitherthestapes(2cases)ortheroundwindow(2cases).PuretoneandspeechaudiometryresultsanddailycommunicationcapabilitiesbeforeandafterVSBactivationwerecompared.ResultsTheoperationsweresuccessfulinallpatients,withnocomplications.ThepatientcommunicationlevelimprovedsignificantlyafterVSBactivation.Averageairconductionpuretonethresholdorconditionedreflexaudiometrythresholdimprovedby35dBinthe0.25-4kHzrange,from69dBHLbeforeVSBactivationto34dBHLafter.Thesentencerecognitionrateinquietat65dBSPLwentupto86%from0%withoutVSBforpatientswithbilateraldeformationandremainedat100%forthepatientwithunilateraldeformity.However,forthelatterpatient,therateimprovedto20%from0%withoutVSBinnoise(-8dBSNR).ConclusionVSBisanexcellentsolutionforimprovinghearinginpatientswithcongenitaldeformationofmiddleandouterears.Operationcanbecompletedandgoodresultscanbeachievedeveninpatientswithuniqueconditionsandneeds.
简介:Theelectricallyevokedsomaticmotilityofouterhaircells(OHC),brieflytermedOHCelectromotility,playsacrucialroleincochlearamplificationthatunderliestheremarkablyhighsensitivityandfrequencyselectivityofthemammalianhearing.AccompanyingOHCelectromotilityisavoltage-dependentgatingchargemovementwithinthecelllateralmembrane,manifestedasameasurablenonlinearcapacitance(NLC)inOHCs.TheelectromotilityandNLCofOHCsarehighlycorrelatedbysharingacommonmolecularsubstrate,themotorproteinprestin.Inthisstudy,wesystematicallycharacterizedthequantitativerelationshipbetweenOHCelectromotilityandNLCintheirvoltagedependencesforthepurposeoffurtherunderstandingtheelectromechanicaltransductioninOHCs.TheresultsdemonstratedthatthetwopossessdifferingvoltagedependenceswiththeV1/2ofelectromotilityconsistentlybeing~20mVdepolarizedincomparisonwiththatofNLCalthoughtheirslopefactorsαarestatisticallyidentical.FurtherinvestigationsshowedthattheinitialstateofOHCsinfluencesthevoltagedependenceofelectromotilitybutnotthatofNLC,indicatingthatsomebiophysicalfactorsotherthanthemotorproteinperseareinvolvedintheprocessofOHClengthchanges.Weproposedthatthecytoskeletalspectrin-actinframeworkunderneaththeOHCplasmamembraneandthecell'sturgorarethetwomostprobablefactorsthatcausethevoltage-dependencediscrepancybetweenOHCelectromotilityandNLC.
简介:Tocloneandconstructtherecombinantplasmidcontainingthemajoroutermembraneprotein(MOMP)geneofChlamydiatrachomatis(C.trachomatis)andtoexpressthefusionproteininE.coliBL21,theMOMPgenewasamphfiedbypolymerasechainreaction(PCR)fromgenomeofC.trachomatisserovarD.ThefragmentwasclonedintotheprokaryoticexpressionvectorpET-22b(+)afterdigestionwithBamHⅠandNotⅠandtransformedintoE.coliXL1-Blue.RecombinantswereselectedbyenzymedigestionandsequencingandtherecombinantplasmidwithMOMPgenewasthentransformedintoE.coliBL21withIPTGtoexpressthetargetgene.TheexpressionrecombinantproteinswerepurifiedbyNi-NTAaffinitychromatography,andidentifiedbySDS-PAGEandWesternblot.Itwasfoundthata1.2kbMOMPgenewasisolated.TheDNAsequenceofMOMPwasfoundtobejustthesameasthesequencepublishedbyGenBank.ArecombinantplasmidcontainingMOMPgenewasconstructedtoexpressthefusionproteinsinE.coli.SDS-PAGEanalysisshowedthattherelativemolecularweightoftherecombinantproteinwasabout47kDathatwasconsistentwiththetheoreticalpredictedvalue,andthespecificityoftheexpressedproteinwasconformedbyWesternblot.ItconcludedthattheMOMPgenecouldbeexpressedintheprokaryoticsystem,bywhichitprovidedthefoundationforthefuturestudiesonthebiologicalactivitiesofC.trachomatisandforthedevelopmentofvaccineagainstthispathogen.
简介:Ashybridcochlearimplantdevicesareincreasinglyusedforrestoringhearinginpatientswithresidualhearing,itisimportanttounderstandelectricallyevokedresponsesincochleaehavingfunctionalhaircells.Totestthehypothesisthatextracochlearelectricalstimulation(EES)fromsinusoidalcurrentcanprovokeanauditorynerveresponsewithnormalfrequencyselectivity,theEES-evokedcompoundactionpotential(ECAP)wasinvestigatedinthisstudy.Briefsinusoidalelectricalcurrents,deliveredviaaroundwindowelectrode,wereusedtoevokeECAP.TheECAPwaveformwasobservedtobethesameastheacousticallyevokedCAP(ACAP),exceptforashorterlatency.Theinput/outputandintensity/latencyfunctionsofACAPsandECAPswerealsosimilar.ThemaximumacousticmaskingforbothACAPandECAPoccurrednearprobefrequencies.SincethemaskedtuningcurveofaCAPreflectsthefrequencyselectivityofneuralexcitation,thesedatademonstrateahighlyspecificactivationoftheauditorynerve,whichwouldresultinhighdegreeoffrequencyselectivity.Thisfrequencyselectivitylikelyresultsfromthecochleartravelingwavecausedbyelectricallystimulatedouterhaircells.
简介:ObjectiveThisstudyistoexploretherelationshipbetweenacetylcholine(ACh)-inducedcalciumreleasefromintracellularCa2+storesandfunctionofouterhaircell(OHC)motors,inanattempttoelucidatethemechanismofOHCelectromotilityatrestingstate.MethodsOHCswereisolatedfromadultguineapig(200-300g)cochleaandloadedwithFluo-3/AM.ThecellsweretreatedwithACh/dHBSS,ACh/HBSS,dHBSSonlyorHBSSonly.Intracellular[Ca2+]ivariationsincellsunderthefourtreatmentswereobservedusinganAr-Krlaserscanconfocalmicroscope.Results[Ca2+]ioscillationswererecordedinfiveOHCstreatedwithACh/dHBSSbutnotinothercells.ThisisthefirsttimethatAch-excited[Ca2+]ioscillationsarereportedinguineapigOHCsindependentofextracellularcalcium.ConclusionsACh-excited[Ca2+]ioscillationsinOHCsoriginatesfromintracellularcalciumreleaseandmayplayacrucialroleinmaintainingactivemechanicalmotilityoftheOHCatrestingandmodulatingOHCelectromotility.
简介:WhensupertyphoonSepatcameclosetotheFujiancoastlineonthenightof18August2007(codedas0709inChineseconvention),anassociatedtornado-likeseverestormdevelopedat2307–2320BeijingStandardTimeinLonggang,CangnanCounty,WenzhouPrefecture,ZhejiangProvinceapproximately300kmawayintheforwarddirectionofthetyphoon.Thestormcausedheavylossesinlivesandproperty.Studyingthebackgroundoftheformationofthestorm,thispaperidentifiessomeofitstypicalcharacteristicsafteranalyzingitsretrievalofDopplerradardata,verticalwindshearandsoon.Synopticconditions,suchasunstableweatherprocessesandTBB,arealsostudied.
简介:一张图的一个顶点被说统治它的邻居的本身和所有。图G的一个双统治集合是G的顶点的集合D,以便G的每个顶点被D的至少二个顶点统治。图G的双支配数字是G的一个双统治集合的最小的集的势。为图G=(V,E),如果V(G)\D的每个顶点在D有至少二位邻居,子集DV(G)是一个2-dominating集合,当如果,统治G的集合是2-outer-independent的时另外集合V(G)\D是独立的。G的2-outer-independent支配数字是统治G的集合的2-outer-independent的最小的集的势。这份报纸加一个与双支配数字平等者描绘所有树到2-outer-independent支配数字。
简介:ThecausestotheoutersurfacefoldingdefectsinN80-Qoilcountrytubulargoods(OCTG)wereinvestigatedthroughtheobservationofthedefects’morphology,microstructureandtheanalysisofthechemicalcompositions.Itisbelievedthatthedefectwasresultedfromtheintrinsicflawsthatoriginallyexistedonthebillet;theywereextendedandoxidizedduringthefollowingreheatingandrollingprocesses.Withmorestrictqualitycontrolandinspectionofthebillet,thedefectcanbepreventedeffectivelyfromoccurring.