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381.
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Cell surface interactions involving carbohydrate may be important in immune recognition. Previous work from this laboratory has demonstrated the presence of 'lectin-like' receptors on mouse peritoneal macrophages that bind bacteria by means of their cell wall sugars. Others have shown that Ia molecules can bind antigen at specific sites which may be involved in presenting antigen to the immune system and recent work has shown that these molecules can carry carbohydrate determinants. It has also been found that human Ia molecules can bind to carbohydrates. As cell surface carbohydrate recognition mechanisms have been implicated in other immune interactions sugar-specific receptors may have a function in self--non-self recognition. We show here that the binding of the bacterium Staphylococcus albus to mouse peritoneal macrophages was inhibited by various conventional and monoclonal antibodies to Ia antigens suggesting that an I-region gene product may be associated with the binding of unopsonized bacteria. 相似文献
383.
Abscisic acid and morphogenesis in Lemna polyrhiza L 总被引:3,自引:0,他引:3
G R Stewart 《Nature》1969,221(5175):61-62
384.
Inhibition of rhinovirus by isatin thiosemicarbazone analogues 总被引:4,自引:0,他引:4
J M Gladych J H Hunt D Jack R F Haff J J Boyle R C Stewart R J Ferlauto 《Nature》1969,221(5177):286-287
385.
N-terminal and C-terminal fragments of substance P (SP) have been shown to exert opposite effects on antinociception, grooming and fighting in mice. The present experiments explored whether these findings could be generalized to passive avoidance behavior. Substance P (SP-(1-11] and the C-terminal fragment pyroglutamyl-SP-(7-11) attenuated passive avoidance behavior when picogram amounts were injected into the nucleus accumbens. In contrast, the N-terminal fragment SP-(1-7) had an opposite effect and facilitated passive avoidance behavior. 相似文献
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388.
以Mn^2+催化精氨酸为底物的化学振荡反应研究 总被引:2,自引:0,他引:2
报道了金属离子存在的L-精氨酸-KBrO_3-H_2SO_4-丙酮体系的化学振荡现象的研究结果,考查了不同反应物浓度对振荡反应诱导期、周期和波形的影响,找出了一些特殊规律. 相似文献
389.
刘金兰 《科技情报开发与经济》2001,11(5):11-11,13
依据当前信息资源建设的趋势,提出在宏观上建立以国家和地区级文献情报中心为代表的信息分布或信息资源保障体系,在微观上合理计划个体图书馆资源与网上资源比例的构想。 相似文献
390.
Chromium has been identified as a carcinogenic metal.Incineration is the useful method for disposal of toxic chromium hazard waste and a chromium kinetic model in a flame is very important to study chromium oxidation.Chromium chemical kinetics over a range of temperatures of a hydrogen/air flame is proposed.Nine chromium compounds and fifty-eight reversible chemical reactions were considered The forward reaction rates are calculated based on the molecular collision approach for unknown ones and Arrhenius's Law for known ones.The backward reaction rates were calculated according to forward reaction rates, the equilibrium constants and chemical thermodynamics.It is verified by several equilibrium cases and is tested by a hydrogen/air diffusion flame.The results show that the kinetic model could be used in cases in which the chromium kinetics play an important role in a flame 相似文献