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排序方式: 共有632条查询结果,搜索用时 31 毫秒
61.
H Yamauchi H Fukuyama Y Nagahama Y Katsumi Y Dong J Konishi J Kimura 《Canadian Metallurgical Quarterly》1996,53(11):1103-1109
BACKGROUND: The independent influences of small-intestinal bacterial overgrowth and old age on mucosal immunoglobulin production and secretion have not been assessed. This is an important issue, since luminal IgA deficiency may exacerbate small-intestinal bacterial overgrowth, the prevalence of which is high in selected elderly populations. METHODS: Proximal small-intestinal aspirates were obtained from 33 subjects for bacteriologic analysis and measurement of total IgA, IgM, total IgG. IgG subclass, and IgD concentrations. IgA subclasses were measured in 24 unselected subjects. Serum immunoglobulin and salivary IgA concentrations were measured in all subjects. RESULTS: IgA2 and IgG3 were predominant IgA and IgG subclasses in proximal small-intestinal luminal secretions. Luminal concentrations of IgA2 and IgM, but not IgG3 or any other IgG subclass, were significantly increased in small-intestinal bacterial overgrowth, which was present in 19 of 33 (57.6%) subjects. Old age did not influence these levels. Luminal immunoglobulin concentrations did not correlate significantly with either serum or salivary values. IgD was not measureable in proximal small-intestinal secretions. CONCLUSIONS: Increased luminal concentrations of the secretory immunoglobulins, IgA2 and IgM, occur in small-intestinal bacterial overgrowth. Local investigation is mandatory when assessing the mucosal immunopathology of this disorder. Luminal IgG3 is unlikely to be predominantly derived from serum. Old age does not independently influence luminal immunity. 相似文献
62.
In 1972, Ghosh introduced the consecutive retrieval (CR) file organization. It is an efficient file organization in which all records pertinent to a query are consecutively stored on linear storage locations.In this paper, we introduce the quasi-consecutive retrieval (QCR) file organization. The QCR file organization is an extension of Ghosh's CR file organization and normally offers less redundancy. In the QCR file, all the records pertinent to each query are not necessarily stored consecutively, but rather they are stored within an area of the buffer size.In this paper, we discuss graph theoretic properties of CR files and QCR files by using the properties of interval graphs well known in graph theory. We provide a basic condition for the existence of a QCR file without redundancy for a given buffer size. By introducing redundant queries, such a condition is simplified.Furthermore, a heuristic computer algorithm is given to organize a QCR file with less redundancy for a given buffer size. 相似文献
63.
An attempt to determine protein denaturing potency of typical surfactants has been made by measuring specific rotation of
bovine serum albumin. The potencies obtained were examined in relation to the intensities of skin roughness in vivo caused
by the surfactants, and a noticeable correlation was found between them. This fact also suggested that the cause of skin roughness
may be attributed to a certain extent to adsorption of surfactants. In addition, this technique is very useful in predicting
the skin roughening potency of a surfactant without using human skin. 相似文献
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67.
Shozo Ishizaka John G. Stockner Katsumi Kobayashi Kunihiro Shima Kenji Katori Humitake Seki 《Water research》1983,17(12):1815-1821
Multi-elemental traces comprising particulate matter in natural water collected during summer in 1978 and 1979 from British Columbia, Canada, were analyzed by α-particle excited X-ray fluorometry. Common elements from all waters examined were Si, Cl, Ca and Fe. The similarity of their distribution in different aquatic environments was statistically analyzed. They were distributed homogeneously in the marine environment but heterogeneously in the freshwater environments. No heavy metals concerned with the environmental standards were detected for all waters examined. 相似文献
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The temperature dependencies of in situ small-angle X-ray scattering (SAXS) of water adsorbed and of adsorption isotherm of water in hydrophobic carbon nanopores were measured over the temperature range of 293 to 328 K. The structures of water nanoclusters adsorbed in the nanopores were determined with the density fluctuation analysis of in situ SAXS data. The difference of the density fluctuations between adsorption and desorption was ascribed to the water structural difference. The structural transitions of the water nanoclusters were observed around 318 K for adsorption and 308 K for desorption. 相似文献
70.
Takuro Kida Katsumi Kurogochi 《International Journal of Circuit Theory and Applications》1982,10(1):43-56
New tolerance measures for lossless or dissipative ladder filters and their numerical evaluation procedures are proposed. The proposed measures provide the approximate values of the statistical mean and variance of the variation of the operating propagation function or characteristic function in nepers. These measures are derived by utilizing a first- to fourth-order Taylor series approximation and can be evaluated easily by a series of simple algebraic operations. Simple formulae are also presented which estimate the error incurred by the neglected terms of this Taylor series approximation. 相似文献