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青海贵德、共和两盆地晚新生代哺乳动物 总被引:22,自引:3,他引:19
本文记述了青海省贵德及共和两盆地的几个含晚新生代哺乳动物化石地点的地层剖面及采自18个地点的26种(代表20个属)哺乳动物化石.对其中的 Myospalax arvicolinus, Microtus, Anancus, Leptobos crassus gonghenensis subsp. nov., L. vallisarni, Bison (Superbison) crassicornis, Boopsis breviceps作了较详细的描述和讨论.通过对动物群的分析初步确定了盆地主要堆积物的时代——贵德盆地:上新世—早更新世;共和盆地:早—中更新世,并简略探讨了两盆地的发育历史. 相似文献
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Summary A brief review is presented of the Vester-Ulbricht -decay Bremsstrahlen hypothesis for the origin of optical activity, and of subsequent experiments designed to test it. Certain of our experiments along these lines, begun in 1974 and involving the irradiation of racemic and optically active amino acids in a 61.7 KCi90Sr–90Y Bremsstrahlen source, have now been completed and are described. After 10.89 years of irradiation with a total Bremsstrahlen dose of 2.5×109 rads, crystallinedl-leucine, norleucine, and norvaline suffered 47.2, 33.6, and 27.4% radiolysis, respectively, but showed no evidence whatsoever of asymmetric degradation.d- andl-Leucine underwent about 48% radiolysis and showed 2.4–2.9% radioracemization. Other samples in solution were too severely degraded to analyze. Probable intrinsic reasons for the failure of the Vester-Ulbricht mechanism to afford asymmetric radiolysis in the present and related experiments involving -decay Bremsstrahlen are enumerated.A portion of this material was presented at the 7th International Conference on the Origins of Life, Mainz, FRG, July 10–15, 1983 相似文献
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Reduced glutathione (GSH) inhibited catalase activity in a dose-dependent manner. DL-dithiothreitol (DL-DTT) and dithioerythritol (DTE) also inhibited catalase activity. The inhibition of catalase by GSH and DL-DTT could be reduced by NADPH. Polyacrilamide gel electrophoresis demonstrated the inhibition was partially reversible. The inhibition of catalase by GSH appeared to be partly due to superoxide radicals, since it was inhibited by active manganese superoxide dismutase, but not by heat-inactivated enzyme. Other chemical species also appear to take part in the inhibition, but they could not be identified. 相似文献
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M R Yi M H Shin M H Leem J S Ryu M H Ahn D Y Min 《The Korean journal of parasitology》1990,28(1):25-30
The direct wet mount examination of vaginal secretion, widely applied for the diagnosis of Trichomonas vaginalis infection in woman patients, is rapid and economical, however, the sensitivity of this technique is not so high. In this study enzyme-linked immunosorbent assay (ELISA) was employed for the detection of serum anti-T. vaginalis IgG and IgM antibodies from 30 vaginal trichomoniasis patients and 30 non-infected healthy persons. The results were as follows: 1. Serum ELISA-IgG value was 0.37 +/- 0.134 (Mean +/- S.D.) in vaginal trichomoniasis patients and 0.21 +/- 0.054 in healthy controls (p less than 0.005), and the sensitivity and specificity of ELISA for serum IgG antibody were 70.0% and 96.7%, respectively. 2. Serum ELISA-IgM value was 0.33 +/- 0.177 (Mean +/- S.D.) in vaginal trichomoniasis patients and 0.11 +/- 0.051 in healthy controls (p less than 0.005), and the sensitivity and specificity of ELISA for serum IgM antibody were 70.0% and 96.7%, respectively. 3. The ELISA-IgG values showed a significant correlation with ELISA-IgM values (r = 0.77, p less than 0.005). With above results, it is assumed that ELISA is a reliable method for the diagnosis of T. vaginalis infection and simultaneous measurement of serum IgG and IgM with this technique is recommended. 相似文献
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长江中游鱼类寄生棘头虫区系的研究 总被引:13,自引:1,他引:12
经过3年10次调查,剖检湖北省宜都、黄冈两处江段所产72种鱼类,共计766尾。收集棘头虫10种,其中包括2新种和1新组合,即蛇鮈新棘吻虫(新种)Neoechinorhynchus saurogobi sp.nov.,长江丽棘虫(新种)Brentisentis yangtzensis sp.nov.(Illiosontidae),鲤丽棘虫(新组合)B.cyprini comb.nov.。对长江中游鱼类寄生棘头虫区系的特点进行了分析和探讨。 相似文献
29.
睾丸间质细胞—研究自体吞噬的一种正常细胞模型 总被引:1,自引:0,他引:1
In the present study, we tried to estimate, in a semiquantitative way, the relative frequency of the autophagic activity in various cell types under physiological condition. The results indicated that the highest activity appeared to be in the Leydig cells of rat testes. Autophagosomes were frequently observed in electron microscope photographs of Leydig cells, which provide a good model to study the autophagocytosis in normal cells. The autophagic process in Leydig cells was observed with the electron microscope in preparations treated to show CMPase activity. The mode of formation of autophagosomes in Leydig cells can be divided into three steps. Step 1, flattened membranous elements expand to enclose a small cytoplasmic territory to form pre-autophagosome. Step 2, The double membrane profile of the pre-autophagosome then completely encloses the cytoplasmic territory to form early autophagosome in which structurally normal organelles are contained. Step 3, the transformation of an early autophagosome into a late one is accompanied by the loss of one of the two delimiting membranes, the partial disintegration of the enclosed content and simultaneous acquisition of acid phosphatase activity. The enzymatic reactivity is acquired following a close association with the lysosomes. The late autophagosome then reaches the cell surface and appear to exocytose their residual content. 相似文献
30.
A simple and effective procedure for the construction of linear restriction fragment maps was developed. Using a two-enzyme digestion, two-dimensional (2-D) electrophoresis procedure, all the restriction fragments in a 50- to 100-kb DNA can be individually resolved and displayed on a 2-D plane. This 2-D gel pattern, with appropriate markers, provides a fixed set of x, y coordinates for each fragment obtained from the single and double digestion as well as the relationship between the two steps. A matrix is constructed from the 2-D pattern. The vertical column shows all the singly digested individual fragments and their sizes obtained from each restriction enzyme treatment, and the dividing horizontal row shows all the doubly digested DNA fragments and their sizes after treatment with two enzymes. The order of arrangement is always from the smallest to the largest fragments. Using this matrix, two linear DNA restriction maps for these two enzymes can be simultaneously constructed in a self-reconfirming manner. As examples for this procedure, we describe the construction of two linear restriction fragment maps, a combination of EcoRI and BamHI digestion as well as a combination of EcoRI and HindIII digestion of lambda-phage DNA. 相似文献