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31.
Summary A pCM2 replicon derived by an N deletion from ::Tn9 which carries the imm434 immunity region is incompatible with some (but not all) IncP-1 plasmids. The imm pCM1 replicon does not show the same incompatibility behavior.  相似文献   
32.
Isolation and characterization of human heart cytochromec oxidase   总被引:2,自引:0,他引:2  
Cytochromec oxidase was isolated from human hearts and separated by SDS gel electrophoresis. The identity of polypeptide bands with known subunits was demonstrated by immunoblotting with monospecific antisera to rat liver cytochromec oxidase subunits. The polarographically determined kinetics of cytochromec oxidation were similar to those reported for the bovine heart enzyme.  相似文献   
33.
Regulation of respiration and ATP synthesis in higher organisms: Hypothesis   总被引:12,自引:0,他引:12  
The present view on the regulation of respiration and ATP synthesis in higher organisms implies only Michaelis-Menten type kinetics and respiratory control as regulatory principles. Recent experimental observations, suggesting further regulatory mechanisms at respiratory chain complexes, are reviewed. A new hypothesis is presented implying regulation of respiration and ATP synthesis in higher organisms mainly via allosteric modification of respiratory chain complexes, in particular of cytochromec oxidase. The allosteric effectors, e.g., metabolites, cofactors, ions, hormones, and the membrane potential are suggested to change the activity and the coupling degree of cytochromec oxidase by binding to specific sites at nuclear coded subunits. Recent results on the structure and activity of cytochromec oxidase, supporting the hypothesis, are reviewed.Dedicated to Professor Dr. Carl Martius on the occasion of his 80th birthday.  相似文献   
34.
From anaerobic freshwater enrichment cultures with 3-hydroxybenzoate as sole substrate, a slightly curved rod-shaped bacterium was isolated in coculture with Desulfovibrio vulgaris as hydrogen scavenger. The new isolate degraded only 3-hydroxybenzoate or benzoate, and depended on syntrophic cooperation with a hydrogenoxidizing methanogen or sulfate reducer. 3-Hydroxybenzoate was degraded via reductive dehydroxylation to benzoate. With 2-hydroxybenzoate (salicylate), short coccoid rods were enriched from anaerobic freshwater mud samples, and were isolated in defined coculture with D. vulgaris. This isolate also fermented 3-hydroxybenzoate or benzoate in obligate syntrophy with a hydrogen-oxidizing anaerobe. The new isolates were both Gram-negative, non-sporeforming strict anaerobes. They fermented hydroxybenzoate or benzoate to acetate, CO2, and, presumably, hydrogen which was oxidized by the syntrophic partner organism. With hydroxybenzoates, but not with benzoate, Acetobacterium woodii could also serve as syntrophic partner. Other substrates such as sugars, alcohols, fatty or amino acids were not fermented. External electron acceptors such as sulfate, sulfite, nitrate, or fumarate were not reduced. In enrichment cultures with 4-hydroxybenzoate, decarboxylation to phenol was the initial step in degradation which finally led to acetate, methane and CO2.  相似文献   
35.
Microbial populations in wetwood of European white fir (Abies alba Mill.)   总被引:1,自引:0,他引:1  
Abstract A method for extraction of microbial populations from wood samples was worked out which gave good recovery of both aerobic and anaerobic microorganisms in agar shake dilution and plating enumerations. This method was applied to the quantification of microbial populations in three European white firs ( Abies alba Mill.) which were afflicted with the European fir disease. Low numbers of aerobic microorganisms (102−104 colony- forming units (cfu) per g fresh tissue) were detected in sapwood irrespective of the degree of affliction. Anaerobic bacteria were usually 1–2 orders of magnitude less frequent. Wetwood of highly diseased firs contained significantly higher numbers of aerobic microorganisms (105−107), whereas the number of anaerobes was not enhanced significantly. Among the prevalent aerobic microorganisms in wetwood were Protaminobacter, Pseudomonas strains, and a yeast. In anaerobic counts from wetwood, Klebsiella and Vibrio strains predominated. The sapwood contained Bacillus, Beijerinckia, Staphylococcus , and Clostridium spp. High numbers of aerobic microorganisms were also detected in the roots and lower stem of a diseased vine plant ( Vitis vinifera L.). The importance of microbial populations in wetwood formation and disease expression is discussed.  相似文献   
36.
An attempt has been made to illustrate the quite complicated process of ethnogenesis in South Asia from the viewpoint of physical anthropology. The numerous invading waves which reached the Indian subcontinent from the northwest played an important role in this process. Most important for the ethnogenesis of South Asia was the invasion of Indo-Aryan groups in the middle of the 2nd millenium B.C. known from historical sources. In large parts of the Indo-Pakistan region they assimilated the aboriginal population in ethnic, cultural and linguistic respects in the course of time. Furthermore, the ethnogenesis of the Indian region is determined by the caste system of Hinduism which, however, is not as rigid as generally assumed. There are numerous evidences that since more than 2000 years a slow but steady process of assimilation and integration of tribal groups, living in the forest areas of Central India, into the Hindu caste system took place, a process which is still going on. It is intended to demonstrate to what degree the ethnogenetic processes in South Asia, known from prehistoric and historical sources, can be traced in human skeletal findings of different time periods as well as in the anthropological structure of the living population. Finally, hypotheses and theories, especially those of Risley and von Eickstedt are discussed, who attempted to interpret the great variability of anthropological and morphological traits in the Indian subcontinent by taking into consideration the existence of different old population substrata and their mixing and assimilation.  相似文献   
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38.
This report presents the results of an investigation designed to establish whether exposure of mice to ultraviolet radiation (UVR) is capable of influencing the factors that control the distribution of lymphoid cells in vivo. We found that such exposure resulted in a dramatic and long-lasting increase in the tropism of peripheral lymph nodes for circulating lymphoid cells. Termination of UVR exposure did not result in a reversal of this phenomenon. Since an increase in lymphocyte migration into the lymph nodes of UVR-exposed mice was apparent within 2 hr of infusion of the radiolabeled cells, we conclude that the homing assay data reflect a relatively increased binding of circulating lymphocytes to high endothelial venules (HEV) within the lymph nodes of irradiated animals. A histologic analysis of skin from UVR-exposed mice established that the dermal microvasculature had expanded in terms of size and number of vessels, a condition that also does not completely reverse after the termination of treatments. In spite of the increase in dermal microvasculature, very few inflammatory cells were detected in the irradiated skin site. These observations support our conclusion that the enhanced traffic of lymphocytes into peripheral lymph nodes of UVR-exposed mice occurs primarily via lymphocyte-HEV interactions rather than afferent drainage of the irradiated skin.  相似文献   
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40.
A new staining procedure for electron microscopical cytology   总被引:47,自引:0,他引:47  
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