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Summary The disappearance of thrombin—formed in the blood, or added to serum-follows a manomolecular reaction-type. Heparin increases the reaction-velocity of this thrombin-inactivating process.Our investigation established that toluidine blue or kinase, which, according to the literature, bind heparin, strongly reduce the speed of thrombin-inactivation too. Therefore the heparin-binding capacity of these substances is also manifested in the decrease of thrombin-inactivation. 相似文献
997.
清代湖州诗人严遂成,在与厉鹗等浙派文人的结社交往中达成了观念、态度上的符契,受到浙派诗风的影响,部分诗歌继承了浙派“宗宋”“尚清”的诗风:在诗学倾向上,以宋诗为宗,师法杜甫、苏轼、黄庭坚等大家;在创作特色上,以学问为诗,写景咏物诗大多清新绮丽。由于丰富的游历经验和强烈的功业情结,严遂成的登临、怀古、咏史诗悲壮激烈、雄气纵横,具有“尚雄”的特殊风貌,显示了对浙派“尚清”诗风的超越。 相似文献
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Optical methods for monitoring neuron activity were developed because these methods lend themselves to simultaneous multiple-site measurements. With the use of new voltage-sensitive dyes, the dye-related pharmacology and photodynamic damage appear to be relatively unimportant. Using multiple-site measurements made with a 124-element photodiode array, we estimated that approximately 30 of the 200 neurons present in the Navanax buccal ganglion make action potentials during feeding and that approximately 300 of the 1100 neurons present in the Aplysia abdominal ganglion are active during the gill-withdrawal reflex. The fact that a light mechanical touch to the siphon skin activated such a large number of neurons in the abdominal ganglion suggests that understanding the neuronal basis of the gill-withdrawal reflex and its behavioral plasticity may be forbiddingly difficult. 相似文献
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Protection of substantia nigra from MPP+ neurotoxicity by N-methyl-D-aspartate antagonists. 总被引:20,自引:0,他引:20
Intake of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) leads to symptoms of Parkinson's disease and produces degeneration of nigrostriatal dopaminergic neurons in humans, giving rise to the hypothesis that this disorder may be caused by endogenous or environmental toxins. Excitation mediated by dicarboxylic amino acids such as L-glutamate or L-aspartate, has been claimed to be involved in pathogenesis of neurodegenerative disorders. We therefore sought to determine whether antagonists active at the NMDA or quisqualate subtypes of L-glutamate receptors prevent toxicity of either MPP+ (1-methyl-4-phenyl-pyridinium ion, the active metabolite of MPTP) or the selective dopaminergic neurotoxin 6-OHDA in the rat substantia nigra pars compacta. We report here that certain selective NMDA antagonists (AP7, CPP, MK-801), but not the preferential quisqualate antagonists CNQX and NBQX, provided short-term (up to 24 h) protection against MPP+ toxicity when coadministered into the substantia nigra. Systemic administration of CPP or MK-801 also offered temporary protection for up to 4 h against MPP+ toxicity. Repeated systemic administration of either compound prolonged protection against MPP+ challenge. Repeated administration for at least 24 h also led to permanent protection, still evident 7 days after intranigral administration of MPP+. 相似文献