| 1 | LED灯串电路保护分析显示文摘随着LED灯越来越多地用于室外,它们发生静电放电以及瞬时产生不稳定电流的风险越来越高,尤其是高亮度的LED灯(配有蓝宝石基片或SiC基片以及未来配有AIN和GaN基片的LED灯)较易受到此类威胁的影响.当灯串中第一个LED灯出现故障时,整个灯串都不亮.很少有工程师对LED灯串电路保护进行全面考虑.例如,被称为“LED开路保护器”的新型装置现已问世,然而人们对其知之甚少.对此,我们将讨论何时使用它们,如何确定其规格,如何利用单个装置保护多个灯串而节约成本. | Teddy To Phillip Havens | 2013 | 中国集成电路2013，22，11： | 2 |
| 2 | Murine fertilized ovum, blastomere and morula cells lacking SP phenotype显示文摘In the field of stem cell research, SP (side population) phenotype is used to define the property that cells maintain a high efflux capability for some fluorescent dye, such as Hoechst 33342. Recently, many researches proposed that SP phenotype is a phenotype shared by some stem cells and some pro- genitor cells, and that SP phenotype is regarded as a candidate purification marker for stem cells. In this research, murine fertilized ova (including conjugate and single nucleus fertilized ova), 2-cell stage and 8-cell stage blastomeres, morulas and blastocysts were isolated and directly stained by Hoechst 33342 dye. The results show that fertilized ovum, blastomere and morula cells do not demonstrate any ability to efflux the dye. However, the inner cell mass (ICM) cells of blastocyst exhibit SP phenotype, which is consistent with the result of embryonic stem cells (ESCs) in vitro. These results indicate that the SP phenotype of ICM-derived ESCs is an intrinsic property and independent of the culture condition in vitro, and that SP phenotype is one of the characteristics of at least some pluripotent stem cells, but is not shared by totipotent stem cells. In addition, the result that the SP phenotype of ICM cells disap- peared when the inhibitor verapamil was added into medium implies that the SP phenotype is directly associated with ABCG2. These results suggest that not all the stem cells demonstrate SP phenotype, and that SP phenotype might act as a purification marker for partial stem cells such as some pluripo- tent embryonic stem cells and multipotent adult stem cells, but not for all stem cells exampled by the totipotent stem cells in the very early stage of mouse embryos. | XU YiXin1, HE ZhiYing2, ZHU HaiYing2, CHEN XueSong2, LI JianXiu2, ZHANG HongXia2, PAN XingHua3 & HU YiPing2 1 ChangZheng Hospital, affiliated to Second Military Medical University, Shanghai 200003, China 2 Department of Cell Biology, Second Military Medical University, Shanghai 200433, China 3 Department of Genetics, Yale University School of Medicine, New Haven, CT 06519, USA | 2007 | Science China(Life Sciences)2007，50，6： | 2 |
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