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1.
Industrial toxicology of metals of the platinum group   总被引:1,自引:0,他引:1  
Metals of the platinum group have found important application in technology and industry. Compounds of these metals display a broad spectrum of toxic effects on the organism. In persons dealing with them in the production, they induce allergic occupational diseases of the respiratory passages, dermatoses, affections of the eyes. Their resorptive chronic effect in experiment is characterized by reduction in the body mass of the animals and the content of haemoglobin in the blood, by disturbances of the protein-synthesizing function of the liver, decreased cholinesterase activity in the blood, impaired carbohydrate and lipid metabolism, reduced concentrating capacity of the liver, development of glomerulonephritis. Platinum and platinoids irritate mucous membranes and skin. They penetrate the organism through intact skin. Data on the distribution of the metals in the organs and on their elimination from the organism are reported. Toxicity of the metals of the platinum group is correlated with valence of the compounds and with electron structure. MAC for milling and condensation aerosols of poorly soluble compounds (metal and its oxides) are recommended at 0.1 mg/m3. For aerosols of all soluble compounds of platinum and platinoids, MAC of 0.001 mg/m3 are recommended.  相似文献   
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A total of 4664 bacteriological analyses of the wound and purulent discharge from orthopedo-traumatological patients were performed within a 6-year period, i.e. from 1971 to 1976. Staphylococci were the dominating microbes of the purulent-inflammatory foci. Its part in the monoculture amounted to 64.5--82 per cent. The specific weight of the monocultures of various microbes decreased during the last 3 years, while the number of the microbial associations increased from 11.6 to 25.4 per cent Staph. aureus predominated in the inflammatory processes (65.8 to 86.5 per cent). Still, during the last 3 years the number of Staph. epidermidis increased from 16.8 to 26.2 per cent. The number of the so called "intermediate" or dissociated type of Staphylococcus, i.e. Staph. albus usually amounted to 7.5--8.1 per cent. In 1976 its number was 12.5 per cent. The pathogenic microbes of the coccal group were usually sensitive to erythromycin, monomycin, levomycetin and kanamycin. Among these microbes only staphylococci preserved their sensitivity to penicillin. The causative agents of purulent processes, i.e. Escherichia, Proteus, Pseudomonas were resistant to most of the antibiotics. Sensitivity to monomycin was preserved by 50 per cent only in Proteus. The microbial associations were mainly sensitive to monomycin and kanamycin.  相似文献   
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Two types of MS2 particle are revealed when phage lysates are banded in CsCl density gradient. The lower band contain normal phage particles with a density of 1.46 g/cm3. The upper band with a density of 1.44 g/cm3 containes uninfective incomplete MS2 particles. Both phage types reveal no abnormalities in the content of the coat protein and A-protein. They are nearly identical in RNA content. RNA in the normal buoyant density phage particles is native. RNA in the defective particles consists of three specific fragments with molecular weights 6.5-10(5), 5.5-10(5) and 4.4-10(5) and molar ratios 5:4:9 respectively. THE 5'-TERMINAL ANALYSIS OF RNA from defective MS2 particles reveals the presence of native pppGp. THE 3'-TERMINAL ANALYSIS OF THE INDIVIDUAL RNA fragments reveals the presence of adenosine only in the shortest fragment. RNA fragmentation in defective particles can be explained by the action of intracellular RNAses on the unprotected regions on RNA chain in structurally incomplete virions.  相似文献   
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Pink salmon introduced into the White Sea started to exploit as spawning grounds middle and upper reaches of the river 20 years after its appearance in the Indera River. As a result of this, the migration pathway of smolts and late smolts appeared in addition to early smolts. The intraspecies polymorphism of smolts is confirmed by differences of early and late smolts by body length and weight, migration dates, food spectrum, and indices of stomach fullness. The food spectra of late juveniles of pink salmon coincide with those of parr of Atlantic salmon Salmo salar and of brown trout S. trutta. Greater abundance of late migrants of pink salmon may cause competition of these species for food.  相似文献   
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Diverse functions of ethylene in plants may depend on its ability to interact with other hormones. We studied the participation of ethylene in the regulation of accumulation and metabolism of cytokinins comparing ethylene-insensitive mutant plants of arabidopsis (Arabidopsis thaliana [L.] Heynh., etr1-1) with the plants of original ecotype Columbia (Col-0). Because cytokinins can regulate growth of both leaves and roots, we determined the weights of these organs and the ratio between them. The content of zeatin and its riboside in the roots of etr1-1 plants was two times greater than in Col-0 plants, which could be accounted for by inhibition of conversion of these forms of cytokinins into 9-N-glucosides. In the leaves of mutant plants, expression of IPT3 gene responsible for the synthesis of cytokinins was more intense than in Col-0 plants, which could also contribute to a rise in the content of cytokinins. In this case, the weight of roots in etr1-1 mutants was lower than in the plants of original ecotype. Because high concentrations of cytokinins can inhibit root growth, suppression of accumulation of their biomass in mutant plants may be related to a greater content of cytokinins therein. The obtained results suggest that ethylene can suppress accumulation of cytokinins and, thereby, maintain redistribution of biomass in favor of the roots, which is important for plant adaptation to a shortage of water and ions.  相似文献   
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World Journal of Microbiology and Biotechnology - Derived from RNA, 5?-ribonucleotides, especially Inosine-5?-monophosphate (IMP) and guanosine-5?-monophosphate (GMP), can enhance...  相似文献   
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The phylogeography of an endangered salmonid, European grayling (Thymallus thymallus), was studied based on analysis of 17 nuclear microsatellite DNA loci. In agreement with earlier mitochondrial DNA (mtDNA) studies, phylogenetic relationships of the populations suggested that northern Europe was colonized from two distinct Pleistocene refugia. Furthermore, microsatellites revealed highly supported grouping of mainland Swedish, Norwegian, Danish, German and Slovenian populations, suggesting that grayling from the northwestern and central Europe have descended from their southern conspecifics. The level of divergence between populations was substantial, even across short geographical distances. Although this was in part due to postglacial colonization patterns and contemporary barriers for gene flow, the high divergence estimates between hydrologically connected sampling locations implied efficient interpopulation reproductive isolation. Microsatellites revealed that the populations exhibited, on average, only 3.5 (+/-2.2) alleles per locus, indicating that T. thymallus has strikingly low levels of intrapopulation genetic diversity as compared with other freshwater fish species. Accordingly, as indicated by analysis of molecular variance (AMOVA), only 49.1-58.0% of the total grayling microsatellite diversity resided within populations. A latitudinal genetic diversity gradient, potentially resulting from glaciation-mediated founder events, was not evident. Alternatively, it is possible that grayling display limited dispersal behaviour/capability, leading to low long-term effective population sizes and, consequently, depauperate intrapopulation polymorphism. These findings have implications for conservation of T. thymallus. Importantly, they exemplify that microsatellites can be highly informative for intraspecific phylogeography studies dealing with substantial divergence scales.  相似文献   
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Pumala virus recombinant nucleocapsid protein was used for the early diagnosis of haemorrhagic fever with renal syndrome. Specific IgM in the sera of patients could be determined by the IEA technique as early as on days 2-3 from the onset of the disease. The diagnostic effectiveness of the test-system was 95% and its specificity was 98%.  相似文献   
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