简介：LVDS、ECL、CML是目前应用较多的几种用于高速传输的逻辑电平。本文介绍每种逻辑电平的接口原理、特点、设计及应用场合,归纳比较它们的特性,举例说明不同逻辑电平之间的互连以及高速逻辑电平电路在现代医疗仪器中的应用。

简介：南方锈病是我国玉米产区的主要病害,玉米抗病品种的利用是控制其为害的一条最为安全和经济的途径。但是,在我国当前的玉米育种中,所利用的玉米南方锈病基因多来自美国杂交种78599等。为寻找新的南方锈病抗病基因,本研究对CIMMYT自交系CML470的抗性进行了遗传分析。结果发现CML470的抗性由一个显性抗病基因（定名为RppC）控制,该抗病基因被定位于10号染色体短臂端部,位于SSR标记umc1380和umc1291之间,分别与两标记相距3.5cM和8.8cM。通过回交,并利用分子标记辅助选择,RppC被转移到了优良自交系昌7-2中。

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简介：Objective:Toinvestigatetheinvitrocleavageabilityandeffectsonapoptosisandcellgrowthofthebcr-ablfusiongenespecificmulti-unitribozymes.Methods:Threefusionpointspecificribozymesweredesignedandthemulti-unitribozymes'invitrotranscriptionvectorandretroviralvectorwereconstructed.Theinvitrocleavageabilitywastested.TheretroviralvectorwastransfectedintoK562cellandtheeffectsonproliferation,apoptosis,cellcycleandcellstructurewereobserved.Results:Multi-unitribozymeshadinvitrocleavageefficiencyof70.8%,whichwasmoreefficientthansingle-unitanddouble-unitribozymes.TransfectionoftheretroviralvectoroftheribozymeintoK562cells,inducedinhibitionofcellgrowthandapoptosis.TheincorporationrateofDNAinribozymestransfectedK562cellswasgreatlydecreasedalongwithtimepassed,withaninhibitionrateofmorethan50%after96hoftransfection.UnderFCM,18.4%ofthecellsunderwentapoptosis72haftertransfectionandmorecellswereblockedinGphase,withtheratioinSphasegreatlydecreased(41.9%).Underelectronmicroscope,compactionofnuclearchromatinandapoptosisbodieswereobserved.Conclusion:Multi-unitribozymesspecifictobcr-ablfusiongenecanbeusedtotreatCMLandtopurgebonemarrowforself-grafting.

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