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751.
Two new methods for serological grouping of beta-hemolytic streptococci, the nitrous acid extraction procedure of El Kholy et al. and the slide agglutination method of Christensen et al., were compared with the Lancefield hot-hydrochloric acid extraction method in classifying 92 strains of groups A, B, C, and G. The nitrous acid extraction method was easily performed, specific, and sensitive when highly potent antisera were used. For the Christensen method these highly potent antisera had to be diluted to avoid cross-reactions between groups A and C and groups B and G, respectively. A few strains, most of them group B, could not be grouped by the latter method. Using these three grouping methods, two sets of commercial sera were compared with the more potent sera supplied by R. C. Lancefield. The low antibody content of these commercial sera, especially anti-group B and G sera, contributed to the inferior results obtained in some of the grouping reactions. 相似文献
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A recent advance in metallurgical technology has been the application of rapid solidification techniques to Al alloy production. FVS0812 is the designation given to a microcrystalline Al-based alloy consisting of 8 wt% Fe, 1 wt% V and 2 wt% Si. It is a two-phase alloy, consisting of ca. 27 vol percent of approximately spherical Fe-V-Si-rich dispersoids in an essentially pure Al matrix. The high strength, low density properties of this advanced material, and other related alloys, have not yet been realized, however, due, in part, to the inability of the alloy to form a thick, adherent, abrasion-resistant outer surface oxide film, a feature readily achieved at conventional Al alloys by normal anodizing methods. The present research has involved an electro-chemical study of oxide film growth at the 812 alloy, with the specific goals being to seek an understanding of the origin of the oxide film growth problem and ultimately to propose alternative approaches to the formation of a thick, stable oxide film at this material. The techniques used in this research have included electrochemical methodologies such as cyclic voltammetry and electrochemical impedance spectroscopy. Crucial information has been obtained through transmission electron microscopy (TEM) of ultramicrotomed specimens. Experiments were carried out initially in neutral borate solutions to characterize the compact barrier oxide film formed in this environment and expected to be present beneath the porous oxide film formed in the normal sulfuric acid anodizing medium.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Effect of muscular dysfunction on the development of shoulder joint in children with Erb's paralysis
In order to evaluate the disturbances of development of the shoulder joint in children with Erb's paralysis the authors conducted an X-ray examination of the shoulder girdle and the shoulder in the anterior-posterior projection. The assessment of the functional state of the muscles of the shoulder girdle was made with the aid of clinical EMG. It was established that there was a retardation of growth and ossification of the radial head of the humerus on the affected side, a decrease in the longitudinal and cross-sectional sizes of the humerus, a retardation in the development of the joint scopular cavity, disorders in spacial interrelationship in the components of the shoulder joint and internal rotation of the shoulder joint. The structural and anatomical changes in the components of the shoulder joint are associated with disorders of the neurotrophic processes in the bone tissue and the muscular dysbalance. 相似文献
758.
Experiments on rats established that tRNA of the liver under the effect of total X-irradiation (800 R), nicotinic acid and neostigmine methylsulphate proves to be hypermethylated. In this case tRNA molecules undergo conformation changes. Nicotinic acid and neostigmine methylsulphate administered to the animals under experiment an hour before irradiation favour the normalization of these indexes. As a rule, a correlation is observed between changes in methylation of tRNA and activity of their methylases. Irradiation inhibits the processes of tRNA synthesis which are normalized under the effect of nicotinic acid administered before the irradiation. Nicotinic acid and neostigmine methylsulphate produce no effect on synthesis of tRNA in the liver of normal animals. The activity of acid tRNase under the effect of nicotinic acid is not changed, under other conditions of the experiment it decreases. Irradiation against a background of nicotinic acid and neostigmine methylsulphate administered to animals and neostigmine methylsulphate administration to the intact animals inhibit the activity of alkaline tRNase. 相似文献
759.
The radioimmunological method was applied to the study of blood testosterone, LH, and FSH content in 41 men suffering from fluorosis, aged from 33 to 45 years. Nineteen men who had no contact with fluorine compounds served as control. In comparison with healthy individuals testosterone content proved to be decreased and FSH content elevated in patients with fluorosis. Blood LH content was increased only in those patients with fluorosis who had long contact with fluorine compounds (over 15 years). The changes in the blood hormone concentration were connected with disturbances of the hormonal, and, possibly, of the germenative function of the testes. The hypophysis proved to suffer less, and the changes of its function were apparently secondary in character. 相似文献
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