拉萨郊区藏族跖纹主线走向分析

本文用茚三酮－味精法采集跖纹,体视显微镜下追踪跖纹主线走向,分析了２５０（男女各１２５人）拉萨效区藏族健康人的跖纹样本。结果显示：Ａ线主要走向１区,其次是７区;Ｂ线亦多止于１区和７区;Ｃ线主要止于和９区;Ｄ线止于１区 频率最高;Ｅ线主要走向１３区;Ｐ三叉缺失较多。Ｐｚ＾ｄ线止共位置较高（１３区和１１区）,而Ｐ＾ｆ线止区较低（７区）。在民族和人种间进行了比较,提示藏族践纹主线走向有自己的特点,又呈现     

精制白喉毒素加β—丙氨酸后脱毒效果观察

精制白喉毒素加０．０２Ｍβ—丙氨酸,再加甲醛溶液经适当的时间解毒,即可转化为完全类毒化且无毒性逆转的精制白喉类毒素。此精白类的脱毒试验、毒性逆转试验、安全试验及效力试验均符合《中国生物制品规程》要求。在脱毒过程中絮状单位的损失明显低于单纯甲醛脱毒者,纯度亦相应得到了提高。     

不同生境区稻田节肢动物群落相似性分析

根据不同生境区稻田节肢动物群落系统调查结果,应用组平均聚类分析法及主成分分析法,讨论节肢动物群落的相似（相异）性问题。结果表明：生境条件及管理措施的差异对群落的结构影响较为明显,不同生境区的稻田节肢动物群落,都能在一定距离取值时聚合成一类,而水稻品种对此影响较小。主成分分析结果由二维图表达已基本满足要求。结果说明大八镇生境区稻田节肢动物群落与岗列镇生境区稻田节肢动物群落差异较大,分别列于两个极端。海陵镇生境区稻田介于两者之间,而与岗列镇生境区稻田节肢动物群落重叠。与聚类分析结果有所差异。这可能与主成分分析法损失部分信息有关。     

Capsid assembly and involved function analysis of twelve core protein mutants of duck hepatitis B virus.

The roles of different regions of the duck hepatitis B virus (DHBV) core protein on viral capsid assembly and related functions were examined. Twelve deletion and insertion mutations which covered 80% of the DHBV C open reading frame were constructed and expressed in Escherichia coli. The N-terminal region (amino acids 3 to 66) of DHBV core protein was important for its tertiary structure and function in E. coli. The expressed core mutants without this region apparently inhibited E. coli growth. The results of transmission electron microscopy of E. coli thin sections, capsid agarose gel, and sucrose gradient sedimentation demonstrated that a few DHBV core mutants with insertion in the N terminus and deletion in the C terminus retained the ability to form core-like particles in E. coli. However, other mutations in most of N-terminal and central regions strongly inhibited the self-assembly ability of DHBV core protein in E. coli. In addition, the mutant with a C-terminal region deletion (amino acids 181 to 228) lost most of the nucleic acid-binding activity of the DHBV core protein.     

Deletion mapping of the rotavirus metalloprotein NS53 (NSP1): the conserved cysteine-rich region is essential for virus-specific RNA binding.

NS53 (NSP1), the gene 5 product of the group A rotaviruses, is a minor nonstructural protein of 486 to 495 amino acids which binds zinc and contains an amino-terminal highly conserved cysteine-rich region that may form one or two zinc fingers. To study the structure-function of the gene 5 product, wild-type and mutant forms of NS53 were produced by using a recombinant baculovirus expression system and a recombinant vaccinia virus/T7 (vTF7-3) expression system. Analysis of the RNA-binding activity of the wild-type NS53 immobilized onto protein A-Sepharose beads with NS53-specific antiserum showed that the protein exhibited specific affinity for all 11 rotavirus mRNAs. The use of short virus-specific RNA probes indicated that NS53 specifically recognizes an element located near the 5' ends of viral mRNAs. Analysis of the RNA-binding activity of deletion mutants of NS53 showed that the RNA-binding domain resides within the first 81 amino acids of the protein and that the highly conserved cysteine-rich region within this region of the protein is essential for the activity. Gel electrophoresis and Western immunoblot analyses of intracellular fractions derived from infected cells revealed that large amounts of NS53 were present in the cytosol and in association with the cytoskeletal matrix. Indirect immunofluorescence analysis of cells programmed to transiently express mutant forms of NS53 using vTF7-3 indicated that the intracellular localization domain resides between amino acids 84 and 176 of NS53. Together, these data show that the RNA-binding domain and the intracellular localization domain lie upstream from the region of NS53 previously determined not to be essential for replication of rotaviruses in cell culture (J. Hua and J. T. Patton, Virology 198:567-576, 1994).     

软紫草愈伤组织的初步培养

外植体来源不同的软紫草愈伤组织产生紫草色素的能力各异。６０Ｃｏ－ｒ射线辐照处理后的Ｈ２无性系愈伤组织生长量和色素产生均属上乘。改良ＭＳ基本培养基添加１毫克／升ＫＴ,０．５毫克／升ＩＡＡ,５％（Ｗ／Ｖ）蔗糖对愈伤组织培养较为适宜。马铃薯提取液对愈伤组织生长有明显的促进作用。     

水平回转对水稻幼苗叶细胞的影响

对在模拟微重力装置上回转１４ 天的水稻幼苗叶细胞进行了亚显微形态、电子探针和细胞酶化学研究。发现叶细胞质膜上Ｃａ２＋ －ＡＴＰ酶活性消失,膜内钙总量上升、膜外钙总量下降,细胞骨架变得疏松,细胞壁变薄并凹凸不平。叶绿体的基粒和线粒体的内嵴亦有部分变化。其变化机制,首先是细胞质膜上Ｃａ２＋ －ＡＴＰ酶活性消失,膜上钙泵停止工作,跨膜钙浓度差减小,膜内钙浓度上升,微管、微丝聚合受阻,细胞骨架疏松,分泌泡移动失去导向,从而导致细胞壁变薄等状态