目的:利用噬菌体7肽库进行体外快速差减筛选(biopanning and rapid analysis of selective interactive ligands,BRASIL),从而获得卵巢癌细胞株HO-8910细胞表面特异性结合肽。方法:以中国仓鼠卵巢细胞株CHO为吸附细胞,卵巢癌细胞株HO-8...目的:利用噬菌体7肽库进行体外快速差减筛选(biopanning and rapid analysis of selective interactive ligands,BRASIL),从而获得卵巢癌细胞株HO-8910细胞表面特异性结合肽。方法:以中国仓鼠卵巢细胞株CHO为吸附细胞,卵巢癌细胞株HO-8910为靶细胞,利用噬菌体展示技术联合差减筛选策略,经过连续5轮生物淘洗,随机挑选13个噬菌体单克隆进行DNA测序,利用噬菌体竞争结合实验、ELISA实验、细胞免疫染色、细胞免疫荧光、合成多肽的竞争抑制实验鉴定阳性噬菌体的亲和性及特异性。结果:筛选出的噬菌体NPMIRRQ与卵巢癌细胞株HO-8910有较高的亲和性及特异性。结论:阳性噬菌体表面展示的多肽NPMIRRQ可能为卵巢癌的早期诊断和转移复发监测提供新思路。展开更多
Microsatellite DNA technique was used to detect the genetic variation between five hatchery populations of the Pacific oyster from China and two wild populations from Japan. Seven microsatellite loci screened in this ...Microsatellite DNA technique was used to detect the genetic variation between five hatchery populations of the Pacific oyster from China and two wild populations from Japan. Seven microsatellite loci screened in this study showed high polymorphism in both hatchery and wild populations, as observed in an average number of allele per locus （19.1-29.9） and average expected heterozygosity （0.916-0.958）. No significant difference in average allelic richness or expected heterozygosity was observed between Chinese hatchery populations and Japanese wild populations. Pairwise Fsr values and heterogeneity tests of allele frequencies showed significant genetic differentiation between all populations. According to the neighbor-joining tree constructed on the basis of the Dc distance, the seven populations fell into three groups showing a clear division between hatchery and wild populations, and between the northern and southern hatchery populations. Assignment tests correctry assigned high percentages （97%-100%） of individuals to their original populations and demonstrated the feasibility of microsatellite analysis for discrimination between populations. The information obtained in this study is useful for designing suitable management guidelines and selective breeding programs for the Pacific oyster in China.展开更多
To solve the problem of finishing the twist blade surface of an impeller, the five-axis numerically controlled electrochemical contour evolution grinding （NC-ECCEG） is studied. Over-cutting errors of NC-ECCEG of the...To solve the problem of finishing the twist blade surface of an impeller, the five-axis numerically controlled electrochemical contour evolution grinding （NC-ECCEG） is studied. Over-cutting errors of NC-ECCEG of the twist blade surface generated by parallel lines are analyzed. The formula for calculating the over-cutting error is deduced. The method for eliminating the over-cutting error is used in the conical grinding wheel and the combined five-axis linkage NC-ECCEG system. The structure and the movement of the NC-ECCEG machine tool,the combined multi-axis NC system and its linkage control technology are introduced. Further, the mathematical model of the NC-ECCEG unparallel-ruled surface is established. An auto-programming system on five-axis NGECCEG is developed to grind the impeller. The machining efficiency of NC-ECCEG increases more than 12 times than that of manual polishing operations.展开更多
文摘目的:利用噬菌体7肽库进行体外快速差减筛选(biopanning and rapid analysis of selective interactive ligands,BRASIL),从而获得卵巢癌细胞株HO-8910细胞表面特异性结合肽。方法:以中国仓鼠卵巢细胞株CHO为吸附细胞,卵巢癌细胞株HO-8910为靶细胞,利用噬菌体展示技术联合差减筛选策略,经过连续5轮生物淘洗,随机挑选13个噬菌体单克隆进行DNA测序,利用噬菌体竞争结合实验、ELISA实验、细胞免疫染色、细胞免疫荧光、合成多肽的竞争抑制实验鉴定阳性噬菌体的亲和性及特异性。结果:筛选出的噬菌体NPMIRRQ与卵巢癌细胞株HO-8910有较高的亲和性及特异性。结论:阳性噬菌体表面展示的多肽NPMIRRQ可能为卵巢癌的早期诊断和转移复发监测提供新思路。
基金the Ministry of Education (No. NCET-04-0640)the National Natural Science Foundation of China (No. 30571442).
文摘Microsatellite DNA technique was used to detect the genetic variation between five hatchery populations of the Pacific oyster from China and two wild populations from Japan. Seven microsatellite loci screened in this study showed high polymorphism in both hatchery and wild populations, as observed in an average number of allele per locus （19.1-29.9） and average expected heterozygosity （0.916-0.958）. No significant difference in average allelic richness or expected heterozygosity was observed between Chinese hatchery populations and Japanese wild populations. Pairwise Fsr values and heterogeneity tests of allele frequencies showed significant genetic differentiation between all populations. According to the neighbor-joining tree constructed on the basis of the Dc distance, the seven populations fell into three groups showing a clear division between hatchery and wild populations, and between the northern and southern hatchery populations. Assignment tests correctry assigned high percentages （97%-100%） of individuals to their original populations and demonstrated the feasibility of microsatellite analysis for discrimination between populations. The information obtained in this study is useful for designing suitable management guidelines and selective breeding programs for the Pacific oyster in China.
文摘To solve the problem of finishing the twist blade surface of an impeller, the five-axis numerically controlled electrochemical contour evolution grinding （NC-ECCEG） is studied. Over-cutting errors of NC-ECCEG of the twist blade surface generated by parallel lines are analyzed. The formula for calculating the over-cutting error is deduced. The method for eliminating the over-cutting error is used in the conical grinding wheel and the combined five-axis linkage NC-ECCEG system. The structure and the movement of the NC-ECCEG machine tool,the combined multi-axis NC system and its linkage control technology are introduced. Further, the mathematical model of the NC-ECCEG unparallel-ruled surface is established. An auto-programming system on five-axis NGECCEG is developed to grind the impeller. The machining efficiency of NC-ECCEG increases more than 12 times than that of manual polishing operations.
