学科分类
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2 个结果
  • 简介:摘要本文基于英语国家语料库BNC和中国学生口笔语语料库SWECCL,运用检索工具Wordsmith,采用语料库语言学的定量分析法和对比语言学的定性语言学的定性分析法,从BNC前50高频形容词中随机抽取full,观察其搭配的类联接模式(colligation)并分析其搭配词的语义韵,并对比将母语者和学习者的用法差异,揭示对英语词汇教学的启示。

  • 标签: 类联接 语义韵 BNC 对比分析 SWECCL
  • 简介:AIM:Toconstructfunctionalhumanfull-thicknesscornealreplacements.METHODS:Acellularporcinecornealmatrix(APCM)wasdevelopedfromporcinecorneabydecellulariztion.Thebiomechanicalpropertiesofanterior-APCM(AAPCM)andposterior-APCM(PAPCM)werecheckedusinguniaxialtensiletesting.Humancornealcellswereobtainedbycellculture.Suspendingringwasdesignedbydeformationofanacupunctureneedle.MTTcytotoxicityassaywasusedtocheckthecytotoxicityofsuspendingringsoakingsolutions.Anewthree-dimensionalorganculturesystemwasestablishedbycombinationofsuspendingring,48-wellplateandmediumtogether.Ahumanfull-thicknesscornealsubstitutewasconstructedfromhumancornealcellswithAAPCMinanorgancoculturesystem.Biochemicalmarkerexpressionoftheconstructwasmeasuredbyimmunofluorescentstainingandmorphologicalstructureswereobservedusingscanningelectronmicroscopy.Pumpfunctionandbiophysicalpropertieswereexaminedbypenetratingkeratoplastyandfollow-upclinicalobservations.RESULTS:TherewerenocellsintheAAPCMorPAPCM,whereascollagenfibers,Bowman’smembrane,andDescemet’smembranewereretained.ThebiomechanicalpropertyofAAPCMwasbetterthanPAPCM.HumancornealcellsgrewbetterontheAAPCMthanonthePAPCM.Therewasnocytotoxicityforthesuspendingringsoakingsolutions.Fortheconstructedfull-depthhumancornealreplacementskeratocytesscattereduniformlythroughouttheAAPCMandexpressedvimentin.TheepitheliallayerwaslocatedonthesurfaceofBowman’smembraneandcomposedofthreeorfourlayersofepithelialcellsexpressingcytokeratin3.OnelayerofendothelialcellscoveredthestromalsurfaceofAAPCM,expressedNa+/K+ATPaseandformedtheendotheliallayer.Theconstructwassimilartonormalhumancorneas,withmanymicrovilliontheepithelialcellsurface,stromalcellswithalongshuttleshape,andzonulaoccludensontheinterfaceofendothelialcells.Theconstructwithstoodsurgicalprocedu

  • 标签: full-thickness human CORNEAL SUBSTITUTE anterior-acellular PORCINE