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71.
海南坡鹿对生境的选择 总被引:5,自引:0,他引:5
1987~1994年,在海南省大田自然保护区及其外围地带对坡鹿的生境选择性进行了调查,发现坡鹿对自然生境有较强的选择性。对不同的生境的选择频率为:落叶季雨林生境47.93%;灌木草地生境39.14%;有刺灌丛生境10.72%;人工林生境2.21%。还对各种生境进行了评价;并提出了保护生境的对策 相似文献
72.
Abstract The present study shows that 20-hydroxyecdysone(20-OHE) participates in the humoral immune responses of Philosamia Cynthia ricini, either normal or debrained pupae, to the E. coli. The mode of action of 20—-OHE is multiple. It raises hemolymph protein content, makes antibacterial proteins be produced, increases lysozyme activity, and activates prophenoloxidase system. It is possible that several immune control systems are involved. 相似文献
73.
高必需氨基酸转基因马铃薯的研究 总被引:8,自引:0,他引:8
80年代以来,马铃薯遗传转化系统日趋成熟,转基因工程植株已被广泛应用于基础科学研究[1]。作为食物蛋白和能量主要来源的马铃薯,提高其蛋白质含量及质量的遗传工程研究正受到人们的普遍关注[2]。Yang等[2]将旨在改善氨基酸平衡的CAT-HEAAE(氯酶素乙酰转移酶-高含量人体必需氨基酸)融合基因导入马铃薯,获得了Southernblot、Northernblot、Westernblot的证据,但尚缺少氨基酸分析的资料。玉米醇溶蛋白(zein)[3]是一个富含甲硫氨酸的贮存蛋白,它和人工合成的HE… 相似文献
74.
75.
Hong-Bo Qu Xian-En Zhang Wen-Wu Chui Shu-Zheng Zhang Gao-Xiang Li Fan Ouyang 《Biotechnology Techniques》1995,9(6):445-450
Summary A dual-enzyme electrode flow injection system that can simultaneously determine glucose and maltose is used for an on-line study of starch hydrolyses catalysed by amylases. With the working system, determinations can be made every 2 minutes. A 10 L sample size with recycled back-flow minimises any loss of the reaction medium. The production, growth and decay of glucose and maltose concentrations during starch hydrolysis under various enzymatic conditions can thus be closely monitored, making it useful for the study of the catalytic kinetics of amylases and in screening and analysing enzyme systems. 相似文献
76.
The mechanism by which pentobarbital anesthesia causes increases in plasma renin activity (PRA) was examined in dogs infused with either propranolol or indomethacin, an inhibitor of prostaglandin synthetase. Infusion of propranolol at 1 mg/kg, (I.V.) followed by 0.6–0.7 mg/kg/hr decreased PRA from 6.98±2.49 ng/m1/hr during control periods to 1.58±0.79 ng/m1/hr 30 minutes after the injection of propranolol (P<0.025). Subsequent induction of anesthesia with sodium pentobarbital caused PRA to rise to 3.87±0.93 ng/m1/hr in 30 minutes. (P<0.01). Plasma potassium concentration decreased from 4.6±0.2 mEq/L to reach 4.0±0.1 mEq/L 30 minutes after induction of anesthesia (P<0.005). Infusion of indomethacin at 5 mg/kg, (I.V.) followed by 1.5 ? 3.1 mg/kg/hr into conscious dogs did not decrease PRA. In contrast to the report by Montgomery et al (Fed. Proc. 36: 989, 1977), we found that the increase in PRA after pentobarbital anesthesia could not be blocked by indomethacin. PRA was 5.3±1.2 ng/m1/hr(M ± SEM) during control periods and was 4.7±1.4 ng/m1/hr 30 minutes after the infusion of indomethacin (P<0.1). PRA increased to 10.9±2.3 ng/m1/hr, 9.2±2.2 ng/m1/hr, and 7.7±1.7 ng/m1/hr at 5, 15 and 30 minutes, respectively, after the administration of pentobarbital (P<0.005, P<0.025, P<0.05). PRA declined to 4.2±1.3 ng/m1/hr 60 minutes after pentobarbital anesthesia (P<0.1). It is concluded that the mechanism by which pentobarbital causes increases in PRA is independent of prostaglandins. 相似文献
77.
78.
李凤民;苗云;张振万 《武汉植物学研究》1991,9(1):75-80
本文提出了一种植物生态学数学模型参数估计的新方法——线性规划法,并结合最小二乘法对模型参数的估计进行了实例分析。认为某种程度上前者更优于后者。是一种值得进一步研究的方法。 相似文献
79.
Identification of an epithelial protein related to the desmosome and intermediate filament network 下载免费PDF全文
Using a mAb, referred to as 08L, we have identified a protein, of M(r) approximately 140,000, associated with desmosomes of epithelial cells. The 08L antibody stained the intracellular side of lateral cell margins of monolayer epithelial cells but did not stain cell margins free of cell contact. Immunoelectron microscopy revealed that the 08L antigen was localized to the cytosolic surface of the desmosomal plaque near points of intermediate filament convergence with apparently little staining of the desmosomal plaque proper. Western blots revealed the 08L antigen to be a protein, of M(r) approximately 140,000, found in the Triton-X 100 insoluble pellet. High salt-containing buffers extracted the 08L antigen from the insoluble material. Examination of the assembly of 08L to the desmosome complex, in cells grown in low confluent culture or in calcium-switch assays, by double immunofluorescence with 08L and anti-desmoplakin antibody, revealed that 08L was recruited to morphologically identifiable desmosomes. 08L antigen may exist in a cytosolic pool prior to assembly to the cell surface. The solubility of 08L in low calcium and normal calcium conditions, however, was similar. 08L association to the desmosome was correlated with increased organization of the intermediate filament network. We suggest that the 08L antigen may be involved in the organization and stabilization of the desmosome-IF complexes of epithelia. 相似文献
80.
S T Hong B I Kim W G Kho J R Yu J Kook J Y Chai C K Yun S H Lee 《The Korean journal of parasitology》1992,30(3):183-189
Molecular karyotyping was applied to Pneumocystis carinii(Pc) from two strains of experimental rats, Sprague Dawley(SD) and Fisher(F), in Korea. Field inversion gel electrophoresis and contour clamped homogeneous electric field electrophoresis resolved 15 chromosomal bands from the Pc. The size of the bands was estimated 270kb to 684kb from SD rats, and 273kb to 713 kb from F rats. The bands of 283 kb from SD rats and of 273 kb from F rats stained more brightly suggesting duplicated bands. Total number of chromosomes was at least 16, and total genomic size was estimated 7 x 10(6) bp. All of the bands from F rats hybridized to the probe of repeated DNA sequences of Pc and the band of 448 kb size was proved to contain rDNA sequences, but Pc. chromosome bands from SD rats showed no reactions to the probes. The 2 different karyotypes of P. carinii from 2 strains of rats were maintained consistently for 2 years. 相似文献