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排序方式: 共有1924条查询结果,搜索用时 15 毫秒
321.
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
322.
The study explored overall and cohort-specific trends in Internet political efficacy from an age-period-cohort approach with a cross-sequential design. Perceived Internet influence on political efficacy is found to increase with age. Significant difference between Internet users and nonusers is also found in some cohorts. Online news reading and online chats/discussions have a positive impact in some cohorts. 相似文献
323.
Phonological awareness in young Chinese children 总被引:1,自引:0,他引:1
Two studies explored the nature of phonological awareness (PA) in Chinese. In Study 1, involving 146 children, awareness of phoneme onset did not differ from chance levels at ages 3-5 years in preschool but increased to 70% correct in first grade, when children first received phonological coding (Pinyin) instruction. Similarly, tone awareness was at better than chance levels from second year kindergarten (age 4), but increased strongly and significantly in first grade to 74% accuracy. In contrast, syllable and rime awareness increased gradually and steadily across ages 3-6 years. Patterns suggest different influences of age and literacy instruction for different PA levels. In Study 2, involving 202 preschoolers, variance in Chinese character recognition was best explained by tasks of syllable awareness, tone awareness, and speeded naming. Findings underscore the unique importance of both tone and syllable for early character acquisition in Chinese children. 相似文献
324.
To develop measures of consumers' self-evaluative motives of Self-verification, Self-enhancement, and Self-improvement within the context of a mall shopping environment, an initial set of 49 items was generated by conducting three focus-group sessions. These items were subsequently converted into shopping-dependent motive statements. 250 undergraduate college students responded on a 7-point scale to each statement as these related to the acquisition of recent personal shopping goods. An exploratory factor analysis yielded five factors, accounting for 57.7% of the variance, three of which corresponded to the Self-verification motive (five items), Self-enhancement motive (three items), and Self-improvement motive (six items). These 14 items, along with 9 reconstructed items, yielded 23 items retained and subjected to additional testing. In a final round of data collection, 169 college students provided data for exploratory factor analysis. 11 items were used in confirmatory factor analysis. Analysis indicated that the 11-item scale adequately captured measures of the three self-evaluative motives. However, further data reduction produced a 9-item scale with marked improvement in statistical fit over the 11-item scale. 相似文献
325.
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
326.
出血性脑血管病介入治疗进展 总被引:2,自引:0,他引:2
出血性脑血管病的介入栓塞治疗由于血管内辅助技术与各种栓塞材料的综合应用取得快速发展,主要有以下三个方面:(1)生物修饰弹簧圈、封堵球囊和支架技术的应用使复杂颅内动脉瘤的介入治疗成为可能;(2)非粘附性液体栓塞剂的应用提高了脑动静脉畸形和硬脑膜动静脉瘘的单纯栓塞治愈率;(3)带膜支架在颅底部巨大动脉瘤和创伤性动静脉瘘取得开创性应用。 相似文献
327.
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
328.
PENG Peng 《Frontiers of Philosophy in China》2011,6(4):549-564
“Xin 心 (Mind)” is one of the key concepts in the four chapters of Guanzi. Together with Dao, qi 气 (air, or gas) and de 德 (virtue), the four concepts constitute a complete system of the learning of mind which is composed of the theory of benti 本体 (root and body), the theory of practice and the theory of spiritual state. Guanzi differentiates the two basic layers of mind—the essence and the function. It tries to attain a state of accumulated jing 精 (essence, anima) and nourished qi, in which qi is concentrated in a miraculous way, through a series of methods of mind cultivation and nurturing, including being upright, calm, tranquil and moderate, and to concentrate the mind and intention. The doctrine of mind of the four chapters of Guanzi influenced Daoism and Confucianism and is a key link in the history of Chinese thought. It is a prelude to the merger of Confucianism, Daoism and Buddhism. 相似文献
329.
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
330.
刘鹏 《医学与哲学(人文社会医学版)》2006,27(17):64-65
通过对黄老之学中"天道环周"思想的内涵及其萌芽、发展和成熟的表述,以及《黄帝内经》中有关营卫运行的概括,分析两者在思维方式和理论构建等方面的相似性,"天道环周"对《黄帝内经》中营卫运行理论的形成具有重要影响. 相似文献