简介:Mammaliancelltotipotencyisasubjectthathasfascinatedscientistsforgenerations.AlonglastingquestionwhethersomeofthesomaticcellsretainstotipotencywasansweredbythecloningofDollyattheendofthe20thcentury.Thedawnofthe218thasbroughtforwardgreatexpectationsinharnessingthepoweroftotipotentcyinmedicine.Throughstemcellbiology,itispossibletogenerateanypartsofthehumanbodybystemcellengineering.Considerableresourceswillbedevotedtoharnesstheuntappedpotentialsofstemcellsintheforeseeablefuturewhichmaytransformmedicineasweknowtoday.Atthemolecularlevel,totipotencyhasbeenlinkedtoasingulartranscriptionfactoranditsexpressionappearstodefinewhetheracellshouldbetotipotent.NamedOct4,itcanactivateorrepresstheexpressionofvariousgenes.Curiously,verylittleisknownaboutOct4beyonditsabilitytoregulategeneexpression.ThemechanismbywhichOct4specifiestotipotencyremainsentirelyunresolved.Inthisreview,wesummarizerethestructureandfunctionofOct4andaddresstoOct4functioninmaintainingtotipotencyorpluripotencyofembryonicstemcels.
简介:企业应用集成会遇到不同的网络、操作系统平台、应用系统等等的互连互通问题,基于TIB的企业应用集成方法让不同的系统通过Adaptor插入信息总线来实现不同系统之间的无缝连接,本文分析了Adaptor的作用与构建模型.
简介:Thisarticleanalyzedtheproblemsarisingfromretrofittingthe800kt/avirgindieselhydrofiningunitintoa1.0Mt/aOCT-MgasolineHDSunitattherefineryofLuoyangPetrochemicalCompany,andtheoptimizedmeasuresaimedatimprovementsinoperationofHDSunit.ThepreliminarycalibrationresultshaveindicatedthehighdesulfurizationrateandgoodselectivityoftheHDStechnologytofulfillthedemandofLuoyangPetrochemicalCompanyforproductqualityupgradingwiththetargetsoftechnicalrevampfullyimplemented.