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941.
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The levels of airborne contamination in various areas of two hospitals were determined during a 15-month sampling period, using Casella and Andersen volumetric samplers. Based on nearly 5,000 samples, the mean count per ft3 ranged from 4.5 in obstetric-gynecology delivery rooms to 72.4 in waste-handling areas. The mean count for the entire hospital environment was on the order of 20 contaminants per ft3; 48% were associated with particles >5 μ diam, 30% with particles between 2 and 6 μ diam, and 22% with particles <2 μ diam. The airborne contamination was influenced by traffic, activity, ventilation considerations, and gross surface contamination, but not markedly by seasonal changes. When suitable control measures were implemented, the level of contamination could be diminished and kept low.  相似文献   
944.
Ionization of the air, both the natural and the artificial, underwent a thorough airing at the First International Conference. With the accent on the physical and biological properties of air ions, the clinical aspects and the therapeutic potentialities were, except for one paper, deliberately omitted. It was felt that at this time the basic problems were of greater importance in order to bring some order and restraint into the prevailing chaotic conditions. It was obvious to all participants that the practical results of the meeting exceeded all expectations but that much work still remains to be done before air ionization achieves full recognition and undivided scientific support.  相似文献   
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Genetic Effects of Irradiation on Early Mortality in Swine   总被引:3,自引:2,他引:1       下载免费PDF全文
D. F. Cox  R. L. Willham 《Genetics》1962,47(7):785-788
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947.
Summary This study describes the fine structure of the hamster seminal vesicle. Intact, sexually mature young and aged animals were used to obtain the results presented. The epithelium of the hamster seminal vesicle contains numerous large electron-dense structures, with a single limiting membrane, with many internal granules and, in the aged animals, myelin-like figures. Based on histochemical results presented in this study, and those of others, it is suggested that this material is a lipofuscin pigment. This substance is of special interest inasmuch as in the hamster seminal vesicle epithelium, pigment is a more sensitive indicator of circulating androgen than is, as in the case of the rat seminal vesicle, regression of cell height. It is possible that this pigment takes origin as breakdown products of mitochondria, the endoplasmic reticulum and the Golgi apparatus. The relation of pro-pigment granules and lysosomes is discussed. Results indicate that pigment is formed at sites of increased catabolism in response to a biological insult to the cell.Supported by U.S.P.H.S. grant RG 6583 from the National Institutes of Health, National Institute of General Medical Sciences.  相似文献   
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