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【英文标准名称】:StandardGuideforAssessingMicrostructureofPolymericScaffoldsforUseinTissueEngineeredMedicalProducts
【原文标准名称】:组织工程医用产品用聚合物工作台的微观结构的评估的标准指南
【标准号】:ASTMF2450-2010
【标准状态】:现行
【国别】:美国
【发布日期】:2010
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:F04.42
【标准类型】:(Guide)
【标准水平】:()
【中文主题词】:
【英文主题词】:microstructure;poresize;porevolume;porosity;porousmaterials;tissuescaffolds;Polymericscaffolds;Tissueengineeredmedicalproducts(TEMPs)
【摘要】:Theabilitytoculturefunctionaltissuetorepairdamagedordiseasedtissueswithinthebodyoffersaviablealternativetoxenograftsorheterografts.Usingthepatientx2019;sowncellstoproducethenewtissueofferssignificantbenefitsbylimitingrejectionbytheimmunesystem.Typically,cellsharvestedfromtheintendedrecipientareculturedinvitrousingatemporaryhousingorscaffold.Themicrostructureofthescaffold,thatis,itsporosity,themeansize,andsizedistributionofporesandtheirinterconnectivityiscriticalforcellmigration,growthandproliferation(AppendixX1).Optimizingthedesignoftissuescaffoldsisacomplextask,giventherangeofavailablematerials,differentmanufacturingroutes,andprocessingconditions.Allofthesefactorscan,andwill,affectthesurfacetexture,surfacechemistry,andmicrostructureoftheresultantscaffolds.Factorsthatmayormaynotbesignificantvariablesdependonthecharacteristicsofagivencelltypeatanygiventime(thatis,changesincellbehaviorduetothenumberofpassages,mechanicalstimulation,andcultureconditions).Tissuescaffoldsaretypicallyassessedusinganoverallvalueforscaffoldporosityandarangeofporesizes,thoughthedistributionofsizesisrarelyquantified.Publishedmeanporesizesanddistributionsareusuallyobtainedfromelectronmicroscopyimagesandquotedinthemicrometerrange.Tissuescaffoldsaregenerallycomplexstructuresthatarenoteasilyinterpretedintermsofporeshapeandsize,especiallyinthreedimensions.Therefore,itisdifficulttoquantifiablyassessthebatch-to-batchvarianceinmicrostructureortomakeasystematicinvestigationoftherolethatthemeanporesizeandporesizedistributionhasoninfluencingcellbehaviorbasedsolelyonelectronmicrographs(Tomlinsetal,(1)).Fig.1givesanindicationofpotentialtechniquesthatcanbeusedtocharacterizethestructureofporoustissuescaffoldsandthelengthscalethattheycanmeasure.Clearlyarangeoftechniquesmustbeutilizedifthescaffoldistobecharacterizedindetail.Theclassificationandterminologyofporesizes,suchasthosegiveninTable2,hasyettobestandardized,withdefinitionsoftermsvaryingwidely(asmuchasthreeordersofmagnitude)betweendifferingapplicationsandindustries.BothTable2andthesupportingdetaileddiscussionincludedwithinAppendixX2describedifferencesthatexistbetweenIUPAC(InternationalUnionofPureandAppliedChemistry)definitionsandthecommonterminologycurrentlyutilizedwithinmostlifescienceapplications,whichincludebothimplantandtissueengineeringapplications.Sincetheliteraturecontainsmanyothertermsfordefiningpores(Perretetal(3)),itisrecommendedthatthetermsusedbyauthorstodescribeporesbedefinedinordertoavoidpotentialconfusion.Additionally,sinceanyofthedefinitionsinTable2canshift,dependendingontheporesizedeterminationmethod(seeTable1andFig.1),anaccompanyingstatementdescribingtheutilizedassessmenttechniqueisessential.AllthetechniqueslistedinTable1havelimitationsforassessingcomplexporousstructures.Fig.2aandFig.2bshowathrough-andablind-endporerespectively.Porometrymeasurements(see7.4)areonlysensitivetothenarrowestpointalongavariablediameterthrough-poreandthereforecangivealowermeasureoftheporediameterthanotherinvestigativetechniques,suchasscanningelectronmicroscope(SEM),whichmaysampleatadifferentpointalongthepore.Thephysicalbasisofporometrydependsonthepassageofgasthroughthematerial.Therefore,thetechniqueisnotsensitivetoblind-endorclosedpore.......
【中国标准分类号】:G45
【国际标准分类号】:11_100
【页数】:10P.;A4
【正文语种】:英语


【英文标准名称】:Stainlesssteels-Chemicalcomposition
【原文标准名称】:不锈钢化学成分
【标准号】:ISO/TR15510-1997
【标准状态】:作废
【国别】:国际
【发布日期】:1997-11
【实施或试行日期】:
【发布单位】:国际标准化组织(ISO)
【起草单位】:ISO/TC17
【标准类型】:()
【标准水平】:()
【中文主题词】:规范(验收);化学分析和试验;钢;化学成分;材料规范;分类系统;不锈钢
【英文主题词】:steels;stainlesssteels;classificationsystems;specification(approval);materialsspecification;chemicalcomposition;chemicalanalysisandtesting
【摘要】:
【中国标准分类号】:H59
【国际标准分类号】:77_140_20
【页数】:12P;A4
【正文语种】:英语