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Ellis JR Villemagne VL Nathan PJ Mulligan RS Gong SJ Chan JG Sachinidis J O'Keefe GJ Pathmaraj K Wesnes KA Savage G Rowe CC 《Neurobiology of learning and memory》2008,90(2):404-412
Neuronal nicotinic acetylcholine receptors (nAChRs) are critical for higher order cognitive processes. Post-mortem studies suggest reductions in nAChRs (particularly the alpha(4)beta(2) subtype) with ageing and in Alzheimer's disease (AD). This study aimed to; (1) quantify nAChR distribution in vivo with 2-[18F]fluoro-A-85380 (2-FA) in 15 early AD patients compared to 14 age-matched, healthy controls (HC) and (2) correlate nAChR distribution with cognitive performance in both groups. All participants were non-smokers and underwent cognitive testing along with a dynamic PET scan after injection of 200 MBq of 2-FA. Brain regional 2-FA binding was assessed through a simplified estimation of Distribution Volume (DV(S)). The AD group differed significantly from HC on all cognitive measures employed, with impairments on measures of attention, working memory, language, executive function, visuospatial ability, verbal learning and verbal memory (p<.05). Contrary to post-mortem data this study found no evidence of in vivo nAChR loss in early AD despite significant cognitive impairment. Furthermore, no correlation between nAChR and cognitive performance was found for either group. The findings of the current study suggest preservation of nAChRs early in AD supporting previous studies. It is possible that while the clinical 2-FA PET method described here may be insensitive in detecting changes in early AD, such changes may be detected in more advanced stages of the illness. 相似文献
183.
本文分析了生态危机的文化根源,试图从新的视野来审视和重构自然、生产力、企业和发展等一系列传统概念,重建生态经济持续发展的新的哲学观. 相似文献
184.
从先齐的东夷族到春秋战国,优越的地理环境下相对发达的社会经济催生了相对先进的传统齐鲁文化,它影响了齐鲁书家的文化选择和书法实践,促使古代山东属地成为中国书法的重镇,也促使古代山东书法地域风格的形成,它超时空的丰厚思想内容和润物无声的文化穿透力,也同样影响了建国后当代山东书法地域风格的形成和发展。 相似文献
185.
抽象与立象:普遍性追寻的两种道路 总被引:1,自引:0,他引:1
西方哲学在生存论上以视觉的“看”为优先,所建立的范畴(“相”)相应于“看”而更注重形式性,注重存在的“明”性(清楚明白性),通达“相”的道路则是以分离为特征的“抽象”;中国哲学在生存论上以整个人的“感”为优先,所建立的范畴(“象”)相应于“感”而更注重形式质料统一,注重世界“幽”与“明”的统一性,通达“象”的道路是“立象”、“取象”。两种通达普遍性的道路不同,所达到的“普遍性”的内涵也不尽相同。 相似文献
186.
一、明确科学和宗教的涵义科学与宗教的关系历来是一个重大的话题,也是一个十分复杂的问题。长期以来,科学与宗教关系的讨论之所以分歧很大,首先在于参与讨论的主体自身的世界观和方法论存在着差异;其次,对于什么是科学,什么是宗教这些基本概念认识上和使用上也不统一。如果参与讨论者在这两个基本问题上达不成共识,讨论引发的根本分歧是不可能弥合的。在无神论学会的会议上讨论科学与宗教的关系问题,应该说在世界观和方法论上,大家基本上趋于一致。但同时也要对什么是科学,什么是宗教加以科学界定,尽可能形成共识,在此基础上才能展开深入的研究。 相似文献
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188.
Understanding print: early reading development and the contributions of home literacy experiences 总被引:2,自引:0,他引:2
Levy BA Gong Z Hessels S Evans MA Jared D 《Journal of experimental child psychology》2006,93(1):63-93
This study explored the development of children's early understanding of visual and orthographic aspects of print and how this is related to early reading acquisition. A total of 474 children, ages 48 to 83 months, completed standardized measures of phonological awareness and early reading skills. They also completed experimental tasks that tapped their understanding of what constitutes "readable" print. The parents of participants completed a questionnaire regarding their children's home literacy experiences. The data showed systematic development in children's understanding of print conventions and English orthography and spelling. Regression analyses indicated that print knowledge was related to early reading skill, even after accounting for variance due to age and phonological awareness. Furthermore, parents' ratings of the extent of their children's involvement in activities that led to practice in reading and writing most consistently predicted the development of emerging literacy skills, including understanding of the conventions of the English writing system. Little relation between print knowledge and the frequency of storybook reading by adults was observed. 相似文献
189.
Role conflict and ambiguity of CEOs in international joint ventures: a transaction cost perspective 总被引:1,自引:0,他引:1
Insights from transaction cost economics were used to study the boundary conditions underlying the role conflict and ambiguity of 265 CEOs in Chinese-based international joint ventures. Role conflict and ambiguity were lower when the contract between parents was more complete. Contract completeness fully mediated the effects of parent objective gap and parent formalization on role ambiguity but only partially so in the case of role conflict. Role conflict was lower when the foreign parent was dominant in the venture but higher when the local parent was dominant. Role conflict and ambiguity were inversely related to cultural distance. Neither construct had a detrimental effect on international joint venture performance. Implications for role theory are discussed. 相似文献
190.