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排序方式: 共有1340条查询结果,搜索用时 15 毫秒
241.
Liu YF Chen HI Yu L Kuo YM Wu FS Chuang JI Liao PC Jen CJ 《Neurobiology of learning and memory》2008,90(1):81-89
Cognitive functions usually involve various synaptic proteins and neurotrophic factors in the hippocampus. However, whether treadmill exercise can improve learning and memory by upregulating some of these molecules remain unraveled. To address this question, male BALB/c mice were divided into control and exercise groups, the latter group went through 4 weeks of treadmill exercise training. At the end of exercise training period, they were either tested for passive avoidance (PA) performance or sacrificed for quantifying the hippocampal levels of brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B (TrkB, the BDNF receptor), synaptotagmin (a Ca2+-dependent synaptic vesicle protein), and SNAP-25 (a presynaptic vesicular fusion protein). Our results showed that treadmill exercise training (1) increased the retention latency without affecting the fear acquisition in the PA test, (2) transiently increased the hippocampal BDNF level at 1, 2, and 4 h after the completion of exercise training, and (3) persistently increased the hippocampal protein levels of full-length TrkB, phosphorylated TrkB and synaptotagmin, but not truncated TrkB or SNAP-25. Moreover, the protein expression level of full-length TrkB or synaptotagmin was positively correlated with PA performance in mice. Finally, inhibition of TrkB signaling by K252a abolished the exercise-facilitated PA performance and upregulation of TrkB and synaptotagmin. Taken together, these data suggest that the upregulation of TrkB and synaptotagmin in the hippocampus contributes to the exercise-facilitated aversive memory. 相似文献
242.
急性心肌梗死发病年轻化的因果分析 总被引:1,自引:0,他引:1
越来越多的中青年人因急性心肌梗死住院甚至猝死,其发病具有原因和结果的必然联系。过劳、不良生活习惯、吸烟、大量饮酒等原因都会使冠状动脉内斑块形成或冠状动脉痉挛而诱发急性心肌梗死。患者及医务工作者都应针对病因及发病机制积极治疗并有效预防,从而提高全民的心血管健康水平。 相似文献
243.
公共领域中的集群效能研究述评 总被引:1,自引:0,他引:1
公共领域中的集群效能是指公众通过分享所在地区的公共信任和社会凝聚力, 从而对于共同努力实现所在地区特定目标的一种集体信念和预期。公共领域中的集群效能有其独特的测量方法和研究结论, 集群效能的相关前因变量可以分为社会认同、社会经济地位和社会参与, 集群效能的相关影响作用研究可以分为公共安全、政治行为、公共卫生三个领域内的研究。文章最后指出未来在公共领域中集群效能研究有必要加强作用机制、动态变化等方面的探讨。 相似文献
244.
食管癌诊断方法研究,涵盖流行病学、生物化学、病理学、肿瘤学、分子生物学等多学科.临床需求是医学科学进步的原动力,科技进步推动了医学发展,食管癌诊断方法的研究和正确的科研思路在控制食管癌发病率和死亡率中起重要作用. 相似文献
245.
从20世纪70年代开始,社会能力的概念为国外研究者广为接受,有关社会能力的理论和实践探索不断深化扩展,西方学者对社会能力的定义和测量、对教师期望、成绩差异、危险行为以及对社会能力的结构、作用和培养方案进行的探讨,极大地增进了教育、心理学工作者对于儿童社会适应和认知发展的理解。西方学者关于社会能力的研究成果对于我国素质教育有着重要的启示。 相似文献
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249.
There are an infinite number of possible word-to-word pairings in naturalistic learning environments. Previous proposals to solve this mapping problem have focused on linguistic, social, representational, and attentional constraints at a single moment. This article discusses a cross-situational learning strategy based on computing distributional statistics across words, across referents, and, most important, across the co-occurrences of words and referents at multiple moments. We briefly exposed adults to a set of trials that each contained multiple spoken words and multiple pictures of individual objects; no information about word-picture correspondences was given within a trial. Nonetheless, over trials, subjects learned the word-picture mappings through cross-trial statistical relations. Different learning conditions varied the degree of within-trial reference uncertainty, the number of trials, and the length of trials. Overall, the remarkable performance of learners in various learning conditions suggests that they calculate cross-trial statistics with sufficient fidelity and by doing so rapidly learn word-referent pairs even in highly ambiguous learning contexts. 相似文献
250.
Childhood obesity is increasingly prevalent in Western and non-Western societies. The authors related multiple dimensions of physical self-concept to body composition for 763 Chinese children aged 8 to 15 and compared the results with Western research. Compared with Western research, gender differences favoring boys were generally much smaller for physical self-concept and body image. Objective and subjective indexes of body fat were negatively related to many components of physical self-concept, but--in contrast to Western research--were unrelated to global self-esteem and slightly positively related to health self-concept. In support of discrepancy theory, actual-ideal discrepancies in body image were related to physical self-concept. However, consistent with the Chinese cultural value of moderation, and in contrast to Western results, being too thin relative to personal ideals was almost as detrimental as being too fat. The results reflect stronger Chinese cultural values of moderation and acceptance of obesity than in Western culture and have implications for social and educational policy in China. 相似文献