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871.
872.
双单抗的免疫层析一步法用于早妊诊断的研究 总被引:2,自引:0,他引:2
在试管式、微孔式和斑点式的酶免测定法测定人绒毛膜促性腺激素(HCG)的基础上,发展了应用双单克隆抗体的免疫层析一步法测定HCG。此法用胶体金标记抗βHCG单克隆抗体,将抗αHCG单克隆抗体包被在硝酸纤维素膜上。无需分离步骤,特别是在进行测定时除加入样品外无需再加任何试剂,此方法特别迅速、简便,2~5min即可得结果。凡HCG浓度>25IU/L的样品可得到阳性结果。在人体血或尿中可能出现的高浓度的干扰物质,如抗坏血酸、乙酰水杨酸、雌二醇、蛋白质、胆红素、甘油三酯等对本测定均无干扰作用,在促黄体激素(LH)浓度高达500IU/L时仍与HCG没有交叉反应。能进行测定的最高值大于300IU/ml,这表示,当HCG浓度达到妊娠期的最高值时仍不会有假阴性结果。 相似文献
873.
在吲哚乙酸不同位点偶联载体蛋白对其抗体特异性的影响 总被引:2,自引:0,他引:2
分别选择吲哚乙醇分子上的C1位羧基和吲哚环上的N位作为偶联载体蛋白的位点,用混合酸酐法和甲醛搭桥法分别合成了两种免疫原IAA—CO—NH一HSA和IAA-N-BSA,并进而制得了对吲哚乙酸侧链识别能力不同的两种多克隆抗体,分别可特异识别甲酯化IAA和游离态IAA;用碳化二亚胺法和甲醛搭桥法分别合成IAA—CO—NH-BSAbIAA—N—OVA两种复合物,以之为包被物,建立了两种IAAELISA。其灵敏度分别为0.35pmol和1.80ppmol;检测范围分别为0.78~800pmol和1.95~2000pmol;批内变异系数分别为4.45%和4.79%;批间变异系数分别为1.15%和1.50%。笔者用这两种ELISA检测了兰花气生根和桑树苗样品中IAA的含量,发现两种检测结果相当一致。 相似文献
874.
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
875.
中国海洋浮游端足类的物种多样性 总被引:5,自引:2,他引:3
中国海域已发现浮游端足类122种,呈现从北部往南部海区、从近海往外海区种数逐渐增加,且暖水性也逐渐增强的分布特征。渤海、黄海北部和西南部的浮游端足类同属暖温带分布,黄海东南部和东海西北部为暖温带分布和热带分布的过渡带,东海东部和东海西南部以及台湾海峡、南海均属热带分布,其中东海东部和南海中、南部热带大洋分布的特征显著。 相似文献
876.
对1587名献血员进行了抗-HCV检测,总阳性率5.60%,在不同职业中农民较高,占6.72%,30岁以上为12.76%。我站自改进采浆工艺,严格使用一次性消毒器具后,未发现HCV交叉感染。职业献血者抗-HCV阳性率高达35.48%,易造成输血后HCV感染。对HCV感染OD值阳性30人又进行4-6个月的观察复测,其中16人OD值下降,6人上升,认为OD值的变化与自限性HCV感染有关。 相似文献
877.
Adjacent bundle sheath and mesophyll cells cooperate for carbon fixation in the leaves of C4 plants. Mutants with compromised plastid development should reveal the degree to which this cooperation is obligatory, because one can assay whether mesophyll cells with defective bundle sheath neighbors retain C4 characteristics or revert to C3 photosynthesis. The leaf permease1-mutable1 (lpe1-m1) mutant of maize exhibits disrupted chloroplast ultrastructure, preferentially affecting bundle sheath choroplasts under lower light. Despite the disrupted ultrastructure, the metabolic cooperation of bundle sheath and mesophyll cells for C4 photosynthesis remains intact. To investigate this novel mutation, the Activator transposon-tagged allele and cDNAs corresponding to the Lpe1 mRNA from wild-type plants were cloned. The Lpe1 gene encodes a polypeptide with significant similarity to microbial pyrimidine and purine transport proteins. An analysis of revertant sectors generated by Activator excision suggests that the Lpe1 gene product is cell autonomous and can be absent up to the last cell divisions in the leaf primordium without blocking bundle sheath chloroplast development. 相似文献
878.
Yuh-Shyong Yang A.David Marshall Peter Mcphie Wei-Xi Athena Guo Xiaofu Xie Xiang Chen William B. Jakoby 《Protein expression and purification》1996,8(4):423-429
A phenol sulfotransferase from rat liver (EC 2.8.2.9), expressed inEscherichia colifrom a single cDNA, was purified as two separable but catalytically active proteins. The proteins appeared to be identical to each other and to the natural liver sulfotransferase by comparison of their amino acid constitution, amino-terminal end group, and interaction with a polyclonal antibody raised against the liver enzyme. Each of the recombinant forms, α and β, catalyzed the sulfuryl group transfer from 4-nitrophenylsulfate to an acceptor phenol, a reaction in which 3′-phospho-adenosine 5′-phosphate (PAP) is a necessary intermediate. Only form β, however, catalyzes the physiological transfer of a sulfuryl group from 3′-phosphoadenosine 5′-phosphosulfate (PAPS) to the free phenol. Evidence is presented that sulfotransferase α, but not β, has 1 mol of PAP tightly bound per enzyme dimer. The ability to utilize PAPS as a sulfate donor could be altered: form α could be treated and purified as form β to acquire the ability to use PAPS, whereas form β was treated by extended incubation with PAP, lost its ability to use PAPS, and was purified as form α. 相似文献
879.
Chen J Zhang LF Han C Yu GS Ma J 《Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology》1996,3(1):57-62
We have previously demonstrated that prolonged simulated microgravity (tail-suspension) leads to cardiac alterations with increased resting heart rate, myocardial degradation changes and attenuated myocardial contractility. The present study investigated the potential role of adrenoceptor mechanisms underlying them. Changes of myocardial alpha 1-adrenoceptor (alpha 1-AR) and beta 1-adrenoceptor (beta-AR) in 90-day tail-suspended rats was investigated by the method of radioligand binding assay and application of Scatchard's method. The results showed significantly decreased quantity of specific binding of 125I-BE[2-beta-(4-hydroxy-3-[125I]indophenyl)-ethylaminomethyltetralone] to alpha 1-AR present in membrane derived from ventricular myocardium of the suspended animals, despite the affinity of the alpha 1-AR to 125I-Be was unchanged. But neither the quantity nor the affinity of beta-AR binding to 125I-Pindolol was significantly altered. In addition, the spontaneously beating rate of isolated right atria from tail-suspended animals showed little change in sensitivity and reactivity to the stimulations of graded phenylephrine (alpha-agonist, measured in the presence of beta-antagonist propranolol) and isoproterenol (beta-agonist), compared with the control rats. There were also no obvious differences of the effects of the isoproterenol on the contractility of isolated left ventricular papillary muscles between the two groups. Since myocardial alpha 1-AR mediated-effects include production of cardiac hypertrophy and enhancement of myocardial glucose uptake and glycolysis, the down-regulation of the alpha 1-AR may be a contributor to the cardiac cellular accumulation and the myocardial degradation changes as found in our tail-suspended rats. The data from this study also suggest that the myocardial beta-adrenoceptors are not affected by the prolonged tail-suspension. 相似文献
880.
R. Schoysman B. Lejeune E. Van Roosendaal L. Segal P. Vanderzwalmen M. Nijs B. Vandamme G. Bertin 《Andrologie》1996,6(4):432-439
The authors report their experience with the use of spermatids in TESE programs where mature spermatozoa could not be isolated from testicular biopsies. The details of the indications for spermatid insemination, the technicity of the procedure and the results are exposed. 相似文献