简介：Plantcelllinesdifferredgreatlyintheabilitytowithstandshearstresses.Usingto-baccocellsandlicoricecellsasmodelplantcells,westudiedtheeffectsofshearstressesonthevi-abilityofplantcells.OurexperimentswerecarriedoutonahighshearrateCouetterheometerprovidinghomogeneousandconstantshearstressesoflaminarflow.TheviabilitywasdeterminedbyTTC（2,3,5-Triphenyltetrazoliumchloride）.Theresultswereasfollows.（1）Theviability（V）droppedexponentiallywithtime（t）,namelyV=Exp（-kt）,（k>oisaconstant）.Thismeantthetenabilityofstatisticalhomogeneity.（2）Thevalueofkwasafunctionofplantcells’mechanicalpropertiesandtheshearstressactingontheplantcells.Theshearratecorrespondingtok=owasthecriticalshearratethattheplantcellscouldwithstand.Itcanbeeasilydetermindedbyextrapo-lation.For7-day-oldtobaccocells,itwas1090s-1andfor9-day-oldlicoricecells,itwas6566s-1.（3）Theplantcellsuspensionswerepseudoplasticfluidsfittingτ=Kγn.Forthetobaccocellsus-pensiontested,n=O.73,andforthelicoricecellsuspensiontestedn=0.7.Thusthecriticalshearstressforthetobaccocellswas25dynes/cm2andforthelicoricecellsitwas80dynes/cm2.（4）Oneoftheirreasonsforlicoricecellstohavegreatertolerancetoshearstressesthantobacaccocellsmaybethegeometricfeaturesofthecellsandthesizesofthecells.Thelicoricecellswererod-shaped,butthetobaccocellsweresphericalandlargerthanthelicoricecells.

简介：ＥＦＦＥＣＴＳＯＦＰＵＬＳＥＭＡＧＮＥＴＩＣＦＩＥＬＤＯＮＣＨＡＮＧＥＳＯＦＲＨＥＯＬＯＧＩＣＡＬＰＲＯＰＥＲＴＹＥＦＦＥＣＴＳＯＦＰＵＬＳＥＭＡＧＮＥＴＩＣＦＩＥＬＤＯＮＣＨＡＮＧＥＳＯＦＲＨＥＯＬＯＧＩＣＡＬＰＲＯＰＥＲＴＹＷａｎｇＴｉａｎｙｏｕ...

简介：Cardiopulmonaryresuscitationisasimpleandeffectivemedicaltreatmentforpatientswithsuddencardiacarrest.MostresearchesonCPRareanimalexperimentsandhumantrials.Becausetherearemanyconfoundingfactorspresentinexperiments,conflictingconclusionsareoftendrawn.Inthispaper,wefollowedthelineoftheoreticalresearchonCPR.Then,weadaptedpreviousCPRmodels,simulatedriveCPRtechniquesusingtheadaptedmodel,andcomparedtheirhemodynamicsinthesametestsystem.Throughthecomparison,thesimulationresultsagreequitewellwithexperimentaldata.ThesimulationresultsshowthatwhenexternalcounterpulsationisappliedduringCPR,itmayimprovethecardiacoutputandincreasethediastolicaorticpressure.Yet,externalcounterpulsationisnotwidelyusedduringCPR.Wethinkthatthisexperimentdeservesfurtherresearch.Giventhebenefitsofmodelsandsimulations,ouradaptedmodelmaybeausefultoolinCPRresearch.

简介：INTRODUCTIONCalciumphosphatecements(CPC)overcomethepracticaldisadvantagesofblocksorgranuleslcanbehandledasapasteandsitinsitu.TheirstructureandcompositionclosetothatofHAPmakethembiocompatiblematerials.2Theconventionalcalciumphosphatecementhadsomeproblemssuchaslongsettingtime(30～60min)andlowcompressivestrength,etc.Inoursystem,anα-TCP/TTCPpowdermixturewasmixedwithwatercontainingcitricacidtocontrolthesettingtimeandcompressivestrength.Inthispaper,theeffectsofvariousconcentrationcitricacidsolutionsonthepropertiesofthecementarereported.

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简介：Theapplicationofhumanhomografthasbeenpopularincardiovascularsurgeryandshownperfecteffects.Butthedifficultytogetgraftgreatlylimiteditsclinicalap-plication.Thethawedhomograftcannotbeusedinsomecasessinceitisnotclearwhetheritcanbere-cryopreservedwithoutdamage.Weconductedthepresentstudytoknowthechangesinviabilityofthehomograftafterrefreezinginsixhumanpul-

简介：Theeffectsofvariouscartilageextracellularmatrixontheconstructionofrabbitgrowthplatecartilagetissueinvitrowerestudied.Theresultsshowthatcollagen,proteoglycanandhyaluronicacidcanpromotethegrowthofculturedchondrocytesbuttheeffectsofvariouscartilageextracellularmatrix(ECM)onchondrocytedifferentiationaredifferent.Collagencanpromotethehypertrophyofchondrocyteswhileproteoglycanandhyaluronicacidinhibitthetransitionofmaturechondrocytesintohypertrophiedchondrocytes.

简介：UsingFX-4000strainunit,theprolierationinhumanlungadenocarcinomaA549cellsthatunderwentmechanicalstrainofdifferentwaveform、frequencyanddurationwerestudied.Imageanalysisrevealedthatcellularproliferationrate(PR)reducedsignificantlyaftercellsweresubjectedtosquarewavewith0～20%elongationatfrequency30,40,50and60cycles/minfor2h.ThePRhadnodistinctdifferenceatheartwave,trianglewaveandsinewavegroupcomparedwithcontrol.ItisconcludedthatsquarewaveandhigherfrequencyplayanimportantroleininhibitingA549cellsproliferation.

简介：objective:Theeffectsofdifferentchitosanonpreventingtraumaticperitonealadhesioninratswasstudiedinthispaper.METHODS:96SDratswithinjuredvermiformprocesswererandomlydividedinto4groupsasfollows:groupAwithoutanytreatmentascontrol,groupBtreatedwithchitosangel,groupCtreatedwithpurechitosanfilmandgroupDtreatedwithchistonfilmcontaining50%gelatin.2and4weeksaftersurgery,12ratsineachgroupwererespectivelybellyopenedtoobservechitosandegradationandevaluateperitonealadhesion,andtheadhesivevermiformprocessestissueswerehistopathologicallyobserved.RESULTS:1.DegraaxationinthegroupDwasfasterthanthatinthegroupCbutslowerthanthatinthegroupB.2.2weeksaftersurgerytheadhesioninthegroupBwasmilderthanthatinthecontrolgroup(goupA)(P＜0.05),butthatinthegroupCandD(bothP＜0.05)weremoreseverethanthatinthecontrolgroup.3.4weeksaftersurgery,theadhesioninthegroupBwasmilderthanthatinthecontrolgroup(P＜0.05),butthatinthegroupCandD(bothP＜0.05)weremoreseverethanthatinthecontrolgroup,whereas,therewasnosignificantdifferencebetweenadhesioninthegroupCandgroupD(P＞0.05).4.Histopathologicalexaminaitonindicatedthat:2weeksaftersurgery,inflammatorycellinfiltrationandfibroplasticproliferationdominatedinlocallesionandtheresponsewasmostseyereontheserouscoat,furthermore,theresponseinthecontrolgroupwasmoreseverethanthatinthegroupB,butmilderthanthatinthegroupCandD;4weeksaftersurgery,fibroplasticproliferationdominatedinlocallesionineachgroup,moreover,theresponseinthecontrolgroupwasmoreseverethanthatinthegroupBbutmilderthanthatinthegroupCandD.What'smore,integratedfibrousmembraneformedaroundimplantedmaterialsinthegroupCandD,andthefibrousmembraneswerethinnerinthegroupCthanthatinthegroupD.CONCLUSION:1.Chitosangelhasperfecteffe

简介：ＥＦＦＥＣＴＳＯＦＡＰＡＴＩＴＥＣＥＲＡＭＩＣＳＯＮＣＥＬＬＧＲＯＷＴＨＳＡＮＤＤＮＡＳＹＮＴＨＥＳＥＳＩＮＨＵＭＡＮＯＳＴＥＯＢＬＡＳＴＬＩＫＥＣＥＬＬＥＦＦＥＣＴＳＯＦＡＰＡＴＩＴＥＣＥＲＡＭＩＣＳＯＮＣＥＬＬＧＲＯＷＴＨＳＡＮＤＤＮＡＳＹＮＴＨ...

简介：Osteoblastsofratculturedinvitrowerestimulatedwithpulsed50Hzelectromagneticfieldandbasicfibroblastgrowthfactor(bFGF).TheMTTmethod,flowcytometryandhistochemistrystainingwereusedtodetectcellproliferation,cellcycleandalkalinephosphatase.Theresultsindicated:afterstimulatedby1mTelectromagneticfield,thecellsaremoreabundant,havemoreSphasepercentages,2mTelectromagneticfieldhavenoevidenteffectoncells'growth;comparedwithelectromagneticfield,thecellsstimulatedbybFGFaremoreabundantandhavelargerSphaseratios.ElectromagneticfieldandbFGFhavenoeffectoncells,alkalinephosphatase.Therefore,weconcludedthatelectromagneticfieldcanenhanceosteoblastsgrowthlikesomegrowthfactorsuchasbasicfibroblastgrowthfactor,andtheosteoblasts',characteristicswasnotchanged.

简介：客观：调查长期的权利的影响在室的改变和病人的心脏的功能与上的室的顶端的踱步高级并且酷刑逼供有正常的心结构和心脏的功能的心房与心室的阻塞。另外，我们为选最佳的电极培植为site.Methods提供许多证据：学习参加者包括了为心律调整器代替被招收并且在门诊病人为植入的心律调整器的考试重游的病人。心律调整器被植入到高级的对待和酷刑逼供心房与心室的阻塞。在心律调整器培植的时候，病人们有正常心脏的功能并且没显示出严肃的心疾病或心脏的膨胀。到后续的从培植的持续时间是超过5年。踱步的率比80%高。有左室的喷射部分(LVEF)的病人<50%并且一条左室的结束心脏舒张的直径(LVEDD)>55公里被排除。室的改变被定义为follows:increase在10%的LVEDD和为在培植以后的五年的在25%的LVEF的减小。心脏的功能根据纽约心协会(NYHA)classification.Results被评估:有吝啬的年龄的82个病人的一个总数(66.97?????????????????吗？？

简介：Objective:Toinvestigatetheinfluenceofdifferentrightventricular(RV)pacingsitesonQRSwidth,andtoprovideapotentialreferencesiteforpermanentrightventricularpacinginpatientsimplantedwithpermanentpacemakers.PacingatthesitewiththeshortestQRSdurationmayreducethedeleteriouseffectsofRVpacingonLVfunction,andthushavingbeneficialeffectsonpatient’soutcome.Methods:AllconsecutivepatientswhowereplannedtohavepermanentpacemakerimplantationforaClassIorIIaindicationatourdepartmentfromOctober2010toJuly2012werescreenedfortheparticipationinthisprospective,singlecenter,non-randomizedstudy.ThebaselinesurfaceECGwasanalyzedforQRSwidthandmorphology,respectively.DuringtheimplantationprocedurepatientsweretransientlypacedatdifferentRVlocations(rightventricularapex,rightventricularinflowtract[RVIT],midseptum,highseptumandrightventricularoutflowtract[RVOT])beforetheleadwasplacedatitsfinalposition.Duringpacingatthedifferentpositionsthesurface12-leadsECGwasrecorded.BasedonthesurfaceofECGQRSdurationandmorphologyofthedifferentrightventricularpacingsiteswereanalyzedandcomparedwithbaselineandtoeachother.Results:Atotalof216patients(39%female,meanage69±13years,higherdegreeAVblock30.5%)wasenrolledinthestudy.PacedQRSdurationwassignificantlydifferentbetweenallrightventricularpacingsitescomparedwiththebaselineECG(baseline:106ms±21ms;meanpaced:158ms±16ms;p<0.001).RVApacingshowedthewidestQRS(168ms±16ms).QRSdurationwithRVITpacingwas166ms±15ms,andthatwithRVOTpacingwas165ms±15ms,respectively.QRSdurationwasnotsignificantlydifferentbetweenthesethreepositions.Mid-septalpacingshowedthenarrowestQRS(139ms±19ms)comparedtoallotherpacingsites(p<0.001).Pacingatthehigh-septumshowedabroaderQRS(153ms±14ms)thanthatpacingatthemid-septum.Comparedtootherrightventricularpacingsites

简介：Diastemaoftenoccuredinmaxillarycompletedentureresinbaseintheclinic,although"Lucitone199"hadbeenusedwithmoretensilestrength.Mechanicalex-perimentshaveprovedthehightransversetensilestress(σ_x~+)concentratinginanteri-orteethregionandtheirpalatalsurfaceofmaxillarycompletedentureresinbasewhileitwasexposedtoverticalloadingincenterocclusion.Settingstrengtheningnetinresinbasehasachievedbetterresults.Forevaluatingpurpose,twentykinds

简介：Oneofthechallengesinthefieldoftissueengineeringisthedevelopmentofbiomaterial/cellinteractions.Forthispurpose,theuseofbiologicalmaterialsintissueengineeringrequirestheapplicationofdifferentchemicalorphysicalproceduresforsurfacemodificationinordertoimprovethecellaffinityofbiomaterials.Wehavestudiedtheeffectsofonechemicaltreatmentandonephysicaltreatment:1-(3-dimethylaminopropyl)-3-ethylcarbodiimide(WSC)andentrapment.