体力活动与健康:研究及应用

规律性体力活动对健康的益处已经被既往的研究所证实。多种慢性疾病,包括心脏病、2型糖尿病、高血压、中风、肥胖、骨质疏松以及某些癌症的发病都与缺乏规律性的体力活动有关。权威机构已明确提出了关于体力活动的参与指引。大量的研究致力于体力活动干预措施的制定。本文总结了体力活动与健康的研究证据、体力活动在人群中的评价、以及体力活动干预研究的进展,为中国下一步相关研究的开展提供借鉴。     

有氧运动对慢性应激大鼠脑海马区神经可塑性的影响

摘要：目的：以神经元和神经胶质细胞相关神经生物学变化为切入点,探讨有氧运动对慢性应激大鼠脑海马区神经可塑性的影响。方法：以SD大鼠为研究对象,按照体重均衡分为对照组（CON）、慢性应激模型组（MOD）、氟西汀组（FLU）、低强度运动组（LIR）和中等强度运动组（MIR）。给予大鼠4周慢性应激,并分别伴随氟西汀给药、低强度或者中等强度的运动干预。4周后,通过开场实验、蔗糖饮水实验、新奇抑制摄食实验以及新物体识别实验检测运动对慢性应激大鼠抑郁样行为、焦虑样行为以及认知障碍的影响;同时,利用酶联免疫法和蛋白免疫印迹法,检测运动对慢性应激大鼠血清皮质酮、海马内前炎因子IL1-β,以及蛋白GFAP、S100β、BDNF、p-ERK、p-CREB表达的影响,探讨运动抗抑郁的行为学效应和作用机制。结果：1）低强度和中等强度运动能够显著增加慢性应激大鼠的开场活动、缩短新奇抑制摄食潜伏期,同时提高慢性应激大鼠新物体的识别指数;2）运动有效逆转了慢性应激大鼠血清皮质酮的异常升高,同时降低海马内前炎性因子IL1-β的分泌;3）运动可显著星形胶质细胞的标志性功能蛋白GFAP和S100β的表达水平,增强慢性应激大鼠的BDNF/ERK/CREB信号转导通路中重要蛋白BDNF、p-ERK、p-CREB的表达。结论：运动可以通过提高慢性应激大鼠脑海马区神经可塑性来达到抗抑郁的目的。可能与以下因素有关：1）运动调节血清皮质酮的异常升高,降低海马内前炎性因子的释放,同时,提高与神经胶质细胞相关蛋白GFAP和S100β活性,从而起到神经元保护的作用;2）运动可以通过激活CREB,BDNF以及ERK等重要信号蛋白的表达,提高神经营养作用,促进神经元的生长,增加神经可塑性和神经发生来发挥抗抑郁作用。     

Resting MAPK expression in chronically trained endurance runners

Purpose: There is a paucity of research investigating the expression of mitogen-activated protein kinases (MAPK) in chronically trained (CT) athletes. Thus, it is unclear how MAPK may contribute to performance and muscle adaptation in CT subjects. The purpose of this study was to determine MAPK total protein, and phosphorylated expression of extracellular signal-regulated kinases 1 and 2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38-MAPK (p38) between untrained, and chronically trained runners. Methods: Tissue samples were analysed from sedentary (SED; n?=?5) controls and chronically trained runners (CT; n?=?5). Resting muscle biopsy samples were analysed for total-MAPK – and ratio of phosphorylated/total (p-MAPK) – ERK1/2, JNK, and p38-MAPK via western blotting. Mann–Whitney U tests and effect sizes were utilized to determine differences in total MAPK protein content and phosphorylation status between SED and CT subjects. Results: There was no difference in total-MAPK expression between SED and CT (p?>?.05). p-p38-MAPK tended to be greater for CT compared to SED (p?=?.07). There were moderate effect sizes of decreased pERK/total-ERK (d?=??0.69) and increased pJNK/total-JNK (d?=?0.54) in CT compared to SED. There was a positive correlation between p-p38-MAPK/total-MAPK and the percentage of type I fibres (r?=?0.73, p?=?.016). Conclusion: Contrary to previous studies, chronic endurance training does not greatly influence total MAPK protein expression in chronically trained runners. However, resting phosphorylation of p38-MAPK may contribute to enhanced oxidative metabolism at chronically trained levels. These alterations are likely involved in the different physiological adaptations that occur following long-term training or at highly competitive levels.     

J.B. Priestley,the ‘Modern’ and America

ABSTRACT

J.B. Priestley has often been seen as representative of a nostalgic Englishness which rejected the modern world and, in the process, embraced anti-Americanism. However, as this article suggests, Priestley had a more complicated relationship with both America and modernity than has been accepted. Focusing on the 1930s, it shows how Priestley travelled widely in the United States and came to admire the democratic and collective aspects of American culture, whilst also developing a critique of what he saw as the lack of individuality and creativity in other elements of the ‘mass' society, anticipating arguments he would develop after 1945.     

网络经济下的电子商务成本分析

电子商务是21世纪新的经济增长点,代表着未来经济的发展方向,而目前电子商务的亏损使得人们对电子商务的成本进行分析和探讨。电子商务使交易形式由实体市场转为虚拟市场,这就可能导致交易成本的变化。B2B模式分析了电子商务的成本构成及电子商务下的企业交易成本的变化,探讨了B2B电子商务模式对交易成本的影响。     

针刺精灵威灵穴配合体针治疗腰部扭伤28例分析

腰部扭伤为体育运动及生活中的多发病。临床证明,针刺精灵威灵穴为主,配合体针,对多种急慢性腰部扭伤疗效显著。针刺28例,治愈23例,显效4例,好转1例,总有效率100％。     

电火花线切割3B代码编程方法

3B代码程序是国产数控电火花线切割机床最常采用的格式之一,通过例举典型模具零件的加工,重点介绍直线和圆弧的3B代码编程方法。     

基于云技术的垂直型B2C电子商务平台用户体验研究

本文立足于云技术条件下电子商务系统架构的变革,研究基于云技术的垂直类B2C电子商务平台用户体验影响因素,主要从系统质量视角构建SEM模型,结合信息质量与服务质量,探讨云技术如何具体作用于平台顾客用户的购买体验,最后得出结论:平台系统质量承载云技术变革直接影响平台用户体验,信息质量是直接正向影响平台用户体验的最主要因素,并在系统质量对用户体验影响路径中起中介效应。     

基于ASP.NET和多数据库访问技术的在线考试系统的设计与实现

本文采用B/S模式结构作为系统开发的体系结构,利用ASP.NET技术进行系统开发,通过在三层模式结构中使用抽象工厂设计模式,设计并实现了一个可以支持多种数据库无缝移植的通用考试系统.