排序方式: 共有67条查询结果,搜索用时 0 毫秒
21.
蔗糖梯度离心纯化人类中期染色体①施家琦唐冬生夏家辉(湖南医科大学医学遗传学国家重点实验室,长沙410078)PurificationofHumanMetaphaseChromosomesbySucroseGradientCentrifugationS... 相似文献
22.
Synthetic pyrethroids are considered as possible sub-stitutesfor some organophosphate carbamates or organochlo-rine insecticides,and have been used extensivelyfor morethantwo decades[1].Pyrethroids are preferred over otherinsecticides because of their easy degradation into non-toxic or less toxic metabolites under natural conditions.Consequently,there has recently beena dramatic increaseinthe use of pyrethroid pesticides to control insect pests.However,synthetic pyrethroids were also reported … 相似文献
23.
With the development of modern agriculture,envi-ronmental contamination by a variety of organic toxicagents has been detected in many freshwater systems.These include herbicides,insecticides,surfactants andother organic compounds,which have,been reported byStratton[1]and many other authors to affect boththeir tar-get and non-target organisms whenever dischargedintotheenvironment,thus impairing heavily on the structure andfunction of ecosystems.Therefore,it is necessary to de-velop pesticides w… 相似文献
24.
25.
LI JinE GUO ZhengYan HUANG Wei MENG XiangXi AI GuoMin TANG GongLi CHEN YiHua 《中国科学:生命科学英文版》2013,56(7):619-627
Streptothricins (STs) are used commercially to treat bacterial and fungal diseases in agriculture. Mining of the sequenced microbial genomes uncovered two cryptic ST clusters from Streptomyces sp. C and Streptomyces sp. TP-A0356. The ST cluster from S. sp. TP-A0356 was verified by successful heterologous expression in Streptomyces coelicolor M145. Two new ST analogs were produced together with streptothricin F and streptothricin D in the heterologous host. The ST cluster was further confirmed by inactivation of gene stnO, which was proposed encoding an aminomutase supplying -lysines for the poly-β-Lys chain formation. A putative biosynthetic pathway for STs is proposed based on bioinformatics analyses of the ST genes and experimental evidence. 相似文献
26.
用电穿孔法将线性化的质粒pEGFP—N3分别导入来自129/ter、C57BL/6J和BALB/c3个品系的小鼠胚胎干细胞:MESPU—13、MESPU—35和MESPU—62中,经G418筛选、荧光显微镜镜检、阳性克隆扩增、流式细胞仪分选、再扩增以及核型分析等过程,分别得到核型大于85%的被EGFP稳定标记的细胞株5个(129/ter2个、C57BL/6J1个、BALB/c2个),分别命名为MESPU—13/G1和MESPU—13/G2、MESPU—35/G1、MESPU—62/G1和MESPU—62/G2。从不同品系中各选一个增殖生长快、形态典型的标记细胞株,进行碱性磷酸酶染色、oct4群基因产物的表达检测、类胚形成和体内分化鉴定,结果表明所得到的核型正常的、稳定标记的ES细胞系具有原ES细胞的典型特征。 相似文献
27.
Min HONG Yan-chun CHE Gui-zhen TANG Wei CUN Xue-mei ZHANG Long-ding LIU Qi-han LI 《Virologica Sinica》2008,23(1):43-50
HSV-1 infection-mediated regulation of mRNA translation in host cells is a systematic and complicated process. Investigation of the details of this mechanism will facilitate understanding of biological variations in the viral replication process and host cells. In this study, a comparative proteomics technology platform was applied by two-dimension electrophoresis of HSV-1 infected normal human L-02 cell and control cell lysates. The observed protein spots were analyzed qualitatively and quantitatively by the PDQuest software package. A number of the different observed protein spots closely associated with cellular protein synthesis were identified by matrix-assisted laser-desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS). The expression levels of the RPLP1 protein, which is required for mRNA translation, and KHSRP protein, which is involved in rapid decay of mRNA, were up-regulated, whereas the expression level of RNP H2, which is involved in positive regulation on the mRNA splicing process, was down-regulated. All of these results suggest that HSV-1 infection can influence cellular protein synthesis via modulation of cellular regulatory proteins involved in RNA splicing, translation and decay, resulting in optimisation of viral protein synthesis when cellular protein synthesis is shut off Although there is need for further investigations regarding the detailed mechanisms of cellular protein control, our studies provide new insight into the targeting of varied virus signaling pathways involved in host cellular protein synthesis. 相似文献
28.
Developmental changes in functional expression andβ-adrenergic regulation of I_f in the heart of mouse embryo 总被引:1,自引:0,他引:1
GUI Li SONG MING TANG CHANG JIN LIU HONG YAN LUO HUA MIN LIANG XIN Wu HU JIAOYA XI LIN LIN GAO BERND FLEISCHMANN JURGEN HESCHELER Department of Physiology Tongji Medical College of Huazhong University of Science Technology Wuhan China Institute of Neurophysiology University of Cologne D- Cologne Germany 《Cell research》2002,(Z2)
The hyperpolarization-activated current (If) plays an important role in determining the spontaneous rate of cardiac pacemaker cells. The automatic rhythmicity also exists in working cells of embryonic heart, therefore we studied developmental changes in functional expression and β-adrenergic regulation of Iy in embryonic mouse heart. The expression of If is high in early developmental stage (EDS) (10.5 d after coitus) ventricular myocytes, low in intermediate developmental stage (IDS) (13.5 d) atrial or ventricular myocytes and even lower in late developmental stage (LDS) (16.5 d) atrial or ventricular myocytes, indicating that these cells of the EDS embryonic heart have some properties of pacemaker cells.β-adrenergic agonist isoproterenol (ISO) stimulates If in LDS but not in EDS cardiomyocytes, indicating that the β-adrenergic regulation of If is not mature in EDS embryonic heart. But forskolin (a direct activator of adenylate cyclase) and 8-Br-cAMP (a membrane-permeable analogue of cAMP) increase t 相似文献
29.
CAI Deling LI Hongyan TANG Qisheng & SUN Yao . Key Laboratory of Marine Sedimentology & Environment Geology SOA First Institute of Oceanography State Oceanic Administration Qingdao China . Ocean University of China Qingdao China . Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences Qingdao China 《中国科学:生命科学英文版》2005,48(6):531-539
The determination of trophic level for the biology in a marine ecosystem is very important as alteration of its structure and function may be reflected in the tro-phic level of component species. A change in trophic level indicates variation in an organism’s feeding bi-ology or in the pathway of energy flow from primary producers to the consumer. The gut content analysis is a traditional method for studying trophodynamics of food web in marine ecosystems. Species composition and amounts in al… 相似文献