简介:针对现有发光二极管(LED)汽车后转向灯存在的配光性能不准确、能量利用率低等问题,设计了一款准直配光一体化的LED后转向灯透镜。该透镜根据非成像光学原理和斯涅尔定理,通过迭代求解的方法设计而成,其高度为8.32mm,直径为12.64mm。利用光学软件TracePro对实际光源和后转向灯透镜进行光线追迹模拟,结果表明:在z方向4-80°,Y方向4-80。的矩形区间,发光强度均大于1.6cd;在x方向±20°,Y方向±10°内发光强度呈近似矩形分布,且各测试点结果均满足GB17905-2008要求。该透镜可精确控制LED发出光线,有利于提高配光性能及能量利用率。
简介:<正>DearSir,IamDr.YunLi,fromtheSecondHospitalAffiliatedtoNanchangUniversity,JiangxiProvince,China.IwritetopresentacasereportofIOLimplantationin
简介:AIM:ToinvestigatetheregulationofEaf2proteininmouselenscellsapoptosisinducedbyultraviolet(UV)radiation.METHODS:AneyeofEaf2geneknockoutmiceornormalcontrolmicewasexposedtoUVradiation,andtheotheronewasnon-exposed.AlloflenseswereanalyzedbyTUNELandcaspase3activityassaystodeterminethedifferenceoftheapoptosisinducedbyUVradiation.Inaddition,exposedandnon-exposedlenseswereanalyzedbyquantifiedp53expressionandreal-timereversetranscription-polymerasechainreaction(RT-PCR)ofBax,Bid,Apaf-1,PumaandNoxa,tocompareEaf2geneknockoutmiceandnormalcontrolmice.RESULTS:UVradiationcausedapoptosisoflenscellsinnormalcontrolmiceandEaf2knockoutmice.Activityofcaspase3wassignificantlyhigherinnormalcontrolmicethanEaf2knockoutmice.Expressionofp53proteinwassignificantlyhigherinlensesexposedtoUVradiationthannonexposedlenses,butwassimilarbetweenEaf2geneknockoutmiceandnormalcontrolmiceinthesameUVcondition.AfterexposingtoUVradiation,theanalysisofreal-timeRT-PCRdemonstratedthatmRNAlevelsofPumaandNoxaweresignificantlyhigherinlensesofnormalcontrolmicethanEaf2geneknockoutmice,andthatmRNAlevelsofBax,BidandApaf-1werenotsignificantlydifferentbetweengeneknockoutmiceandnormalcontrolmice.CONCLUSION:Eaf2increaseslenscellsapoptosisinducedbyultravioletradiation.AndEaf2up-regulatesexpressionofthePumaandtheNoxatoactonlenscellsapoptosisafterUVradiation.
简介:目的通过Meta分析,比较CT血管成像(CTA)与MR血管成像(MRA)对颅内动脉瘤的诊断价值。方法检索维普中文科技期刊数据库、中国生物医学文献数据库、中国期刊全文数据库、数字化期刊数据库、PubMed、EMBASE、WebofScience、CochraneLibrary,按照纳入标准筛选关于CTA和MRA对颅内动脉瘤诊断的研究,检索时间均由建库至2012年4月。采用Metadisc1.4软件对数据进行分析,计算诊断的敏感度、特异度、比值比(OR)及95%CI,异质性采用I2检验分析,绘制出汇总受试者工作特征曲线(SROC),并计算曲线下面积。结果共纳入6篇符合标准的文章(均为前瞻性研究),合计370例患者。Meta分析结果示,CTA对颅内动脉瘤诊断的敏感度为0.91(95%CI:0.87~0.94),特异度为0.92(95%CI:0.86~0.96),OR为78.29(95%CI:28.27~216.77),SROC曲线下面积为0.9593。MRA诊断的敏感度为0.85(95%CI:0.80~0.89),特异度为0.92(95%CI:0.86~0.96),OR为41.94(95%CI:18.50~95.09),SROC曲线下面积为0.9304。结论CTA对于颅内动脉瘤的诊断价值高于MRA。但仍需大样本的研究进一步加以证实。
简介:AIM:Toevaluatechangesintheanteriorchamberdepth(ACD),crystallinelensthickness(LT)anditsrefractivepowerafterlaserinsitukeratomileusis(LASIK).·METHODS:Inallcases,thepreoperativeandpostoperativecentralACDwhichweremeasuredwithPentacam,Orbscan,IOL-MasterandA-scanultrasonography,centralcornealtruenetpowerwhichwasmeasuredwiththePentacam,OrbscanandIOL-Master,axiallength(AL)whichwasmeasuredwithIOL-MasterandLTwhichwasmeasuredwiththeA-scanultrasonographywerecomparedusingthepairedsamplettest.OcularrefractiveerrorsandlensrefractivepoweratcornealplanewerecalculatedandtheircorrelationswerealsoevaluatedbeforeandafterLASIK.RESULTS:At1weekafterLASIK,LTandcrystallinelensrefractivepoweratcornealplane(Dlens)whichwereassociatedwiththeIOL-MasterandPentacamincreasedsignificantly(P≤0.005),ACDdecreasedsignificantly(P≤0.001),butnosignificantincreasewasobservedintheDlenswhichwasassociatedwiththeOrbscan(P=0.261).SignificantcorrelationsbetweenthechangesintheocularrefractiveerrorsandDlenswhichwereassociatedwiththePentacamwereobservedat1weekand6monthsafterLASIK(P=0.028;P=0.001).CONCLUSION:LTincreasedsignificantlyafterLASIK,andthismightpartiallyleadtoACDdecrease,Dlensincreaseandasmallquantityofmyopicregression.