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71.
低能量He—Ne激光血管内照射治疗银屑病21例报告   总被引:1,自引:0,他引:1  
21例寻常型银屑病患者,经用He-Ne激光血管内照射,功率3.5-5mw,每日照射一次,每次1小时,10次一疗程,同时伴用vitc2givq.d及鼻吸氧,二疗程间休息4-7天,经5-35次治疗,近期疗效:近期痊愈5例(23.81%),显效6例(28.57%),好转10例(47.62%),总有效率100%,复发1例(4.76%)。  相似文献   
72.
毛细管气相色谱/质谱/计算机联用仪器分析结果表明,在四川省成都市一人工种植的银木(Cinnamomumseptentrionale)种群中,其枝叶精油主要化学组成在各植株间存在很大差异,发现精油存在1,8-桉叶油素,樟脑,异丁香酚甲醇和9-氧代橙花叔醇等四个化学类型.除异丁香酚甲醚类型外,其余类型均为第一次报道.综观樟属其它种的化学类型研究可见,化学类型在樟属植物中普遍存在种内多型性和种间共性.  相似文献   
73.
水稻幼穗组培及白化苗的电镜观察   总被引:7,自引:0,他引:7  
木文报道了五份水稻材料的幼穗组培的诱导率和分化率,对继代8次后的幼穗愈伤分化出的白苗和绿苗及其各自的愈伤进行电镜扫描,发现白苗的质体结构不完整,不能正常合成叶绿素。  相似文献   
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Summary Genetic studies have demonstrated biparental inheritance of plastids in alfalfa. The ratio of paternal to maternal plastids in the progeny varies according to the genotypes of the parents, which can be classified as strong or weak transmitters of plastids. Previous cytological investigations of generative cells and male gametes have provided no consistent explanation for plastid inheritance patterns among genotypes. However, plastids in the mature egg cells of a strong female genotype (6–4) were found to be more numerous and larger than in mature eggs of a weak female genotype (CUF-B), and the plastids in 6–4 eggs are positioned equally around the nucleus. In CUF-B, the majority of plastids are positioned below (toward the micropyle) the mid level of the nucleus, which is the future division plane of the zygote. Since only the apical portion of the zygote produces the embryo proper, plastids in the basal portion were predicted to become included in the suspensor cells and not be inherited. In the present study, we examined zygotes and a two-celled proembryo from a cross between CUF-B and a strong male genotype (301), a cross that results in over 90% of the progeny possessing paternal plastids only. Our results indicate that the distribution of plastids observed in the CUF-B egg cell is maintained through the first division of the zygote. Further, paternal plastids are similarly distributed; however, within the apical portion of the zygote and in the apical cell of the two-celled proembryo, the number of paternal plastids is typically much greater than the number of maternal plastids. These findings suggest that maternal and paternal plastid distribution within the zygote is a significant factor determining the inheritance of maternal and paternal plastids in alfalfa.  相似文献   
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78.
Catalytic residues of gamma delta resolvase act in cis.   总被引:3,自引:0,他引:3       下载免费PDF全文
M R Boocock  X Zhu    N D Grindley 《The EMBO journal》1995,14(20):5129-5140
The resolvase protein of the gamma delta transposon is a site-specific recombinase that acts by a concerted break-and-join mechanism. To analyse the role of individual resolvase subunits in DNA strand cleavage, we have directed the binding of catalytic mutants to specific recombination crossover sites or half-sites. Our results demonstrate that the resolvase subunit bound at the half-site proximal to each scissile phosphodiester bond provides the Ser10 nucleophile and Arg8, Arg68 and Arg71 residues essential for cleavage and covalent attachment to the DNA. Several other residues near the presumptive active site are also shown to act in cis. Double-strand cleavage at one crossover site can proceed independently of cleavage at the other site, although interactions between the resolvase dimers bound at the two crossover sites remain essential. An appropriately oriented heterodimer of active and inactive protomers can in most cases mediate either a 'top' or 'bottom' single-strand cleavage, suggesting that there is no obligatory order of strand cleavages. Top-strand cleavage is associated with the topoisomerase I activity of resolvase, suggesting that a functional asymmetry may be imposed on the crossover site by the structure of the active synapse.  相似文献   
79.
China has made great progress in improving the health of women and children over the past two generations. The success has been attributed to improved living standards, public health measures, and good access to health services. Although overall infant and maternal mortality rates are relatively low there are large differences in patterns of mortality between urban and rural areas. The Chinese have developed a hierarchical network of maternal and child health services, with each level taking a supervisory and teaching role for the level below it. Maternal and child health in China came to international attention in 1995 with the promulgation of the maternal and child health law. In China this was seen as a means of prioritising resources and improving the quality of services, but in the West it was widely described as a law on eugenics.  相似文献   
80.
利用脂肪酶在有机溶剂中催化对映选择性酯化反应对外消旋薄荷醇进行了有效的光学拆分。对分别使用酸酐和相应的游离羧酸作酰基给体时的反应性能进行了比较。发现酸酐的反应性远高于对应的游离羧酸,但在酶的催化作用下酸酐易水解成为游离羧酸;在微水系统中使用过高浓度的酸酐会导致酶缺水而失活,同时会促进手性醇的非选择性酯化,从而降低产物的光学纯度。然而,在连续流加丙酸酐的半批式反应系统中,所有这些缺点均可有效地克服。与使用游离丙酸的批式反应系统相比,dl-薄荷醇的反应时间缩短了一半,酶的稳定性大幅度提高,而产物l薄荷醇酯的光学纯度不相上下(>98%e)。  相似文献   
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