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Immunoelectrophoretic examination of avian serum esterases 总被引:1,自引:0,他引:1
M Kaminski 《Nature》1966,209(5024):723-725
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高校图书馆功能拓展的理论研究与实践探索 总被引:1,自引:0,他引:1
以拓展高校图书馆功能的缘由为切入点,在比较几种高校图书馆功能拓展理论分析方法的基础上,总结了高校图书馆功能拓展的一些实践探索,指出当前研究中存在的问题,并对未来的研究进行了展望。 相似文献
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The origin of multiple superconducting gaps in MgB2 总被引:3,自引:0,他引:3
Souma S Machida Y Sato T Takahashi T Matsui H Wang SC Ding H Kaminski A Campuzano JC Sasaki S Kadowaki K 《Nature》2003,423(6935):65-67
Magnesium diboride, MgB2, has the highest transition temperature (T(c) = 39 K) of the known metallic superconductors. Whether the anomalously high T(c) can be described within the conventional BCS (Bardeen-Cooper-Schrieffer) framework has been debated. The key to understanding superconductivity lies with the 'superconducting energy gap' associated with the formation of the superconducting pairs. Recently, the existence of two kinds of superconducting gaps in MgB2 has been suggested by several experiments; this is in contrast to both conventional and high-T(c) superconductors. A clear demonstration of two gaps has not yet been made because the previous experiments lacked the ability to resolve the momentum of the superconducting electrons. Here we report direct experimental evidence for the two-band superconductivity in MgB2, by separately observing the superconducting gaps of the sigma and pi bands (as well as a surface band). The gaps have distinctly different sizes, which unambiguously establishes MgB2 as a two-gap superconductor. 相似文献
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Studies in the past years have implicated multispan transmembrane transport molecules of the ATP binding cassette (ABC) transporter
family in cellular lipid export processes. The prototypic ABC transporter ABCA1 has recently been demonstrated to act as a
major facilitator of cellular cholesterol and phospholipid export. Moreover, the transporter ABCA4 (ABCR) plays a pivotal
role in retinaldehyde processing, and ABCA3 has recently implicated in lung surfactant processing. These pioneering observations
have directed considerable attention to the A subfamily of ABC proteins. ABCA2 is the codefining member of the ABC A-transporter
subclass. Although known for some time, it was not until recently that its complete molecular structure was established. Unlike
other ABC A-subfamily members, ABCA2 is predominantly expressed in the brain and neural tissues. The unique expression profile
together with available structural data suggest roles for this largest known ABC protein in neural transmembrane lipid export.
Received 31 January 2002; received after revision 11 March 2002; accepted 11 March 2002 相似文献
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The polymorphism observed among the enzymes involved in the respiratory metabolism (lactate dehydrogenase, malate dehydrogenase, phosphoglucomutase, phosphohexoseisomerase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase fructose 1-6 diphosphate dehydrogenase) is less important than that of the enzymes physiologically less essential, such as the various esterases, the alkaline phosphatase, the alcohol dehydrogenase, and of the non-enzymatic proteins (ovalbumin, ovoglobulins, ovomucoid, conalbumin, transferrin, etc.). 相似文献
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Résumé Les taches colorées correspondant à l'activité estérasique des sérums d'oiseaux, après électrophorèse en gélose, diffèrent entre elles en nombre, localization et relative intensité de coloration dans les sérums provenant de familles différentes: Poules, Canards, Pigeons ou d'espèces d'une même famille. Chez certaines espèces, on peut également observer des variations individuelles. 相似文献