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931.
以天然心房肽灌流豚鼠离体工作心脏,药后1分钟心率开始减慢,左室压及其微分开始升高;5分钟后逐渐恢复,至10分钟恢复正常。体外培养大鼠心肌细胞,培养液中乳酸脱氢酶含量在药后2小时减少至48.5±6.8u,为药前的42.7%(P<0.01),药后8小时仍明显低于药前水平。为心房肽的新药开发提示了新思路。  相似文献   
932.
以分泌小鼠抗人纤维蛋白降解产物D-双聚体单克隆抗体杂交瘤细胞株的mRNA为模板,用小鼠免疫球蛋白轻链可变区基因的通用引物,通过RT-PCR扩增基因,与载体重组后,经酶切鉴定和核苷酸序列分析,证明克隆含抗D-双聚体单抗的轻链可变区基因,长度为330 bp.  相似文献   
933.
对49名正常儿童进行了多导视觉诱发电位的观察。结果表明:(1)双眼及单眼VEPs波形在头皮中线两侧分布是非对称性,右偏者较左偏者多,这种非对称性可能与脑组织两侧结构和功能的不对称有关,从而影响到VEPs发生源的位置以及偶极子的方向及强度等。(2)吉利手者右半视野刺激的VEPs振幅,(AnlP1)大于左半视野刺激的VEPs振幅,两半球枕叶皮层神经解剖学上的非对称性为我们的电生理结果提供了一定的形态结构基础。(3)半视野刺激显示“矛盾定侧”现象。  相似文献   
934.
The albumin gene family consists of four evolutionarily related genes that code for serum transport proteins. In rodents, the genes for albumin, |ga-fetoprotein, and |gaALB are physically linked within 100 kilobases of DNA. The fourth gene, Gc, encoding vitamin D-binding protein or group-specific component, maps to the same chromosome as the other family members, but linkage has not been established. This report describes the genetic and physical mapping of Gc in mouse and establishes that, although Gc is genetically linked to the other genes, its physical distance from them extends beyond the resolution range of yeast artificial chromosome cloning and pulsed-field gel electrophoresis. Received: 18 July 1995 / Accepted: 9 September 1995  相似文献   
935.
游泳训练对儿童最大有氧活动能力的影响   总被引:1,自引:0,他引:1  
本文利用步行机对91名8-11岁男女儿童进行最大有氧活动能力的测试,其中训练组42人选自北京市海滨区业余游泳队的儿童,对照组49人(男24人,女25人)选自与训练组儿童条件相近的普通学校学生。观察9个月的游泳训练对儿童有氧活动能力的影响。研究结果表明,训练组儿童的身高,体重,瘦体重和肺活量在观察前及观察后的两次测试中均高于对照组。观察期间形态指标的增长值和两组值在两组间大都无明显差别,表明两组儿童  相似文献   
936.
Abstract:  The aim of this study was to test the hypothesis that the whitefly ( Bemisia tabaci ; Hom., Aleyrodidae) predator ladybird beetles, Delphastus catalinae (Col., Coccinellidae), are not adversely affected in the field by the crude insecticidal toxins extracted from two strains of the fungus Verticillium lecanii , V3450 and Vp28. We developed a method to evaluate sublethal toxicity and its effects on consumption and functional response of D. catalinae . The crude toxins have low toxicity against beetle larva with LC50 values of 1942 (1393–2710) and 2471 (1291–4731) p.p.m., respectively (approximately 10- and 12-fold of field rate of application 200 p.p.m.). The adult beetles had less sensitivity to crude toxins with LC50 values of 4260 (3376–5375) and 4426 (1734–11298) p.p.m., respectively (approximately 20- and 22-fold of field rate 200 p.p.m.). The consumption and foraging capacity were significantly impaired especially in the second-instar larval beetles which took longer time (more than twice of the control beetles) to consume whitefly eggs after exposure to toxins, although D. catalinae suffered no significant effect on fecundity and longevity, when exposed to a toxin dilution of field rate. The data suggest that spraying of V. lecanii or its toxins should be avoided in the field having immature stages of D. catalinae .  相似文献   
937.
In order to determine the effect of various hosts on feeding performance of Rhipicephalus (Boophilus) microplus, we used 3 mammalian species as hosts, cattle (Qinchuan), sheep (T an), and rabbits (Japanese white rabbit) for infest-ing ticks. Five hundreds of R. microplus larvae were exposed to each animal (3 animals/host species). Tick recoveries were 11.0%, 0.47%, and 5.5% from cattle, sheep, and rabbits, respectively. The averages of tick feeding periods were not significantly different on cattle, sheep, and rabbits, 28.8, 25.3, and 26.7 days, respectively. The average weights of individual engorged female from cattle, sheep, and rabbits were 312.5, 219.1, and 130.2 mg, respectively and those of egg mass weights each to 85.0, 96.6, and 17.8 mg. The highest egg hatching rate was in the ticks from cattle (96.0%), fol-lowed by those from rabbits (83.0%) and sheep (19.2%). These data suggest that rabbits could be as an alternative host to cultivate R. microplus for evaluating vaccines and chemical and biological medicines against the tick in the laboratory, although the biological parameters of ticks were less than those from cattle.  相似文献   
938.
939.
940.
Autophagy plays important roles in many biological processes, but our understanding of the mechanisms regulating stem cells by autophagy is limited. Interpretations of earlier studies of autophagy using knockouts of single genes are confounded by accumulating evidence for other functions of many autophagy genes. Here, we show that, in contrast to Fip200 deletion, inhibition of autophagy by deletion of Atg5, Atg16L1, or Atg7 does not impair the maintenance and differentiation of postnatal neural stem cells (NSCs). Only Fip200 deletion, but not Atg5, Atg16L1, or Atg7 deletion, caused p62/sequestome1 aggregates to accumulate in NSCs. Fip200 and p62 double conditional knockout mice demonstrated that p62 aggregate formation triggers aberrant superoxide increases by impairing superoxide dismutase functions. By comparing the inhibition of autophagy by deletion of Atg5, Atg16L1, or Atg7 with Fip200 deletion, we revealed a critical role of increased p62 in determining the fate of autophagy-deficient NSCs through intracellular superoxide control.  相似文献   
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