简介:目的利用Micro-CT扫描数据建立中耳听骨链三维有限元模型。方法用Micro—CT扫描成人颞骨标本,将获得的图像数据通过MicroView、Mimics等软件进行三维重建。再将模型转入其有限元分析(finiteelementanalysis,FEA)模块的Remesh环境中进行调整、细化及面网格优化,通过SOLIDEWORK软件转换为实体网格。结果初步形成的三维几何模型可较清晰地辨别鼓室腔、听小骨和内耳系统,但部分图像不同程度存在噪点。最终形成了FEA软件可识别的成人中耳听骨链三维有限元网格模型,网格划分后的听骨链有限元模型中,完整听骨链的节点数降低,由原来包括805个不合理节点在内的12498个节点降低到2050个,在此基础上建立的有限元模型共1350个8节点四面体单元。结论结合Micro—CT技术及Mimics软件的三维建模方法可以快速获得较精确的听骨链三维数据,是建立听骨链三维有限元模型的有效途径。(中国眼耳鼻喉科杂志,2009.9.83。85)
简介:AIM:Toassesstheeffectivenessofimmunosuppressantsintheprophylaxisofcornealallograftrejectionafterhigh-riskkeratoplastyandnormal-riskkeratoplasty.METHODS:WesearchedtheCochraneCentralRegisterofControlledTrials(CENTRAL),MEDLINE,EMBASE,CNKI,VIPandreferencelistsofarticles.Dateofmostrecentsearch:18June,2011.Allrandomisedcontrolledtrials(RCTs)assessingtheuseofimmunosupressantsinthepreventionofgraftrejection,irrespectiveofpublicationlanguage.Twoauthorsassessedtrialqualityandextracteddataindependently.Onlydichotomousoutcomes(cleargraftsurvival,ratioofimmunereactionsandsideeffects)wereavailableandwereexpressedasrelativerisk(RR)and95%confidenceintervals(CI).RESULTS:Sevenstudieswereincludedinthisreview.Inthecomparingofmycophenolatemofetil(MMF)withplacebo,theresultsshowedMMFcouldsignificantlyreduceimmunereactionscomparedwithplacebo(RR1.0895%Cl0.95to1.21),butnoeffectoncleargraftsurvival(RR1.1195%Cl0.90to1.35).Incleargraftsurvivalandimmunereactions,MMFandcyclosporineA(CsA)showedsimilareffect(RR1.1195%Cl0.90to1.35,andRR1.48,95%Cl0.56to3.93,respectively).Tacrolimus(FK506)andsteroidshowedsimilareffectsoncleargraftsurvivalandimmunereactions(RR0.32,95%CI0.02to6.21,andRR1.00,95%CI0.88to1.14,respectively).Nodrugrelativesideeffecthasbeenfound.CONCLUSION:MMFmayreduceimmunereactionsinbothnormal-riskandhigh-riskrejectionofpenetratingkeratoplasty.CsAandFK506showedsimilareffectsasMMF.However,duetothelackoflargeclinicaltrials,theevidenceremainweak,thequalityofevidenceswereratedasverylowtomoderate.Large,properlyrandomised,placebo-controlled,doublemaskedtrialsareneededtoevaluatetheeffectofimmunosuppressants.