间歇运动激活心梗大鼠心肌NRG1-PI3K/Akt通路抑制心肌细胞凋亡

摘要：目的: 探讨心脏NRG1在间歇运动激活心梗(myocardial infarction,MI)大鼠心肌NRG1-PI3K/Akt通路抑制心肌细胞凋亡的作用。方法：雄性SD大鼠48只,随机分为假手术组(S),心梗安静组(MI),心梗+间歇运动组(ME),心梗+间歇运动+抑制剂组(MEA),每组12只。采用左冠脉前降支结扎法建立MI模型。S组手术仅穿线不结扎。ME组和MEA组在MI术后1wk进行跑台间歇运动。运动开始速度为10m/min运动10min后,速度逐渐增至25m/min×7 min,再以15 m/min×3min运动,之后依次交替进行。60min×1次/d,5d/1wk×8wk。训练结束后次日,腹腔麻醉,颈动脉插管测定LVSP、LVEDP及±dp/dtmax。之后开胸摘取心脏,进行组织学制片,Masson染色。荧光实时定量PCR测定心肌NRG1及其受体ErbB2/4表达。Western Blot法检测心肌NRG1、ErbB2/4、PI3K/Akt、Bcl-2和Bax蛋白含量。Caspase3表达及TUNEL检测观察分析心肌细胞凋亡情况。结果: MI组胶原容积百分比(CVF)和LVEDP较S组显著升高(P<0.01,P<0.01),LVSP和±dp/dtmax显著降低(P<0.01,P<0.01)。且MI后心肌ErbB4 mRNA表达显著降低(P<0.01),心肌NRG1、ErbB2和ErbB4蛋白表达显著降低(P<0.05,P<0.01,P<0.01),PI3K/Akt蛋白表达及Bcl-2/Bax比值显著降低(P<0.01,P<0.01),TUNEL阳性细胞数和Caspase3活力显著增加(P<0.01,P<0.01)。ME组CVF和LVEDP较MI组显著降低(P<0.01,P<0.01),LVSP和±dp/dtmax显著升高(P<0.01,P<0.01),心肌NRG1、ErbB2和ErbB4 mRNA及蛋白表达均显著增加(P<0.01,P<0.01,P<0.01),PI3K/Akt蛋白表达和Bcl-2/Bax比值显著增加(P<0.01,P<0.01),TUNEL阳性细胞数和Caspase3活力显著降低(P<0.01,P<0.01),且运动效应被抑制剂AG1478显著减弱。结论:间歇运动可通过激活心肌NRG1及其受体表达,上调PI3K/Akt蛋白表达,抑制心肌细胞凋亡和胶原过度增生,改善心功能。     

市场化运作对美洲杯帆船赛中国之队的影响

本文采用文献资料法、统计分析法、访谈法、实地调查法,研究美洲杯帆船赛的发展历史及中国之队参加关洲杯比赛的运作方式;研究结果表明美洲杯帆船赛是一项历史悠久、富有挑战性、具有帆船运动高科技含量,耗资巨大,影响力广泛的世界性体育赛事;中国之队的美洲杯运作方式是中国现代体育产业发展的必然结果。     

力量训练和耐力训练的生理基础

无论是对于大众健身还是专业训练,目前一致认为,力量训练能够促使肌肉体积增加、力量增长,而耐力训练则可以改变机体的有氧代谢水平。此外,如果将力量训练跟耐力训练无间隔交叉进行则会产生相互干扰的效果。旨在通过对这两种训练各自的信号转导途径进行分析以及互相干扰现象进行系统地阐述,以期能够为大众健身以及专业训练的人群在训练计划的安排上提供一个合理的理论依据及建议。     

基于ActiGraph GT3X监测网球运动能量消耗的研究

目的:应用ActiGraph GT3X对网球运动等非周期性运动能量消耗进行测评,建立适合网球运动能耗预测的回归方程,从而丰富ActiGraph测量体系.方法:以K4b2测量值作为校标,分别在拍柄、持拍手手腕外侧、腰部髂肌外侧、大腿中央前侧和脚踝外侧(持拍手同一侧肢体)各佩戴一个加速度计(ActiGraph GT3X),同步对网球运动中不同球速下(30 km/h、60 km/h)的原地正、反手击球,侧向移动正、反手击球,向前移动正、反手击球,侧向移动正反手交替击球和模拟自由单打的运动过程进行监测.结果:腰部、大腿和踝关节部位GT3X的EE和MET预测值存在明显低估,与K4b2测量值一致性较低;手腕和拍柄部位GT3X的EE和MET预测值存在明显高估,与K4b2测量值一致性较低;研究建立了2个网球运动能耗预测回归方程,经检验其预测值与实测值没有显著性差异.结论:运用ActiGraph GT3X对网球等隔网对抗运动项目进行监测存在显著误差,EE和MET的预测存在明显高估或低估的现象;基于ActiGraph GT3X所建立的能耗预测方程能对网球运动进行有效的运动监测.     

The Evolution and Cultural Characteristics of Korean Professional Soccer

Abstract

Since it was introduced in the late nineteenth century, soccer has been one of the cultural driving forces for Koreans in overcoming national hardships during the dark ages marked by imperial occupations, war, and division during the modern era. This study was carried out to investigate the cultural backgrounds and characteristics due to which soccer has entered an era of professionalization under the name of the Super League. Korean professional soccer started in 1983 under the name of the Super League, not by popular demand but by from political backgrounds. The sport was off to a bad start, and this became an inherent limitation and the reason Korean professional soccer did not flourish. In addition, although Korean professional soccer had grown rapidly in terms of quantity based on a consistent increase in professional teams and the introduction of advanced systems, the cultural limitations of an incomplete local franchise system and a lack of public attention were revealed. Korean professional soccer has shown a variety of sociocultural limits while rapidly developing in its short history. Nevertheless, having a short history indicates the system is young, which means it has the opportunity to mature. Korean professional soccer has sufficient potential and it can be directed toward a brighter future.     

Ethnic and regional influences on teachers' evaluations of oral answers

Tape recordings were made of six white and six black ninth-grade northern boys speaking identically worded answers to typical school questions. Black students were given significantly higher grades than white students by 56 white and 50 black southern teachers. Black teachers gave significantly higher grades than white teachers, but no significant interaction was found between students' and teachers' ethnic group. The study is a partial replication of a previous study in which it was found that black students were given significantly lower grades than white students by northern white teachers.     

从“招呼语”谈英语语用能力培养

英语教学不仅要教给学生知识,还要培养学生运用知识的能力。但在实际运用中,经常出现语用失误。下面从常见的＂招呼语＂入手,分析语用失误原因,并提出如何培养学生语用能力的具体对策。     

形象手段在喜剧小品中的运用

喜剧小品大量运用比喻、夸张、比拟等形象化的修辞手段来构造幽默,不仅使台词获得了一般意义上的形象生动,富有情趣,而且更凸显了语言的＂陌生化＂,增加了台词的＂可嚼性＂,还表现了戏剧语言＂性格化＂特征。形象手段运用应注意雅与俗、形与神、量与度等问题。     

吕叔湘对中国修辞学的贡献

语言学宗师吕叔湘不仅是语法学家、语文教育家,同时也是一名修辞学家和修辞实践家。吕先生一生十分重视修辞学研究并且始终关注、支持修辞学的健康发展。他对中国修辞学的重要贡献是：开创性研究提供了修辞学研究的新范式;独特修辞观促进了修辞学的科学发展;打造学术平台促进学术交流,发现并培养了杰出的修辞学家。     

不同烘烤阶段温湿度改变对 K326烟叶品质的影响

为探求 K326中上部烟叶最适宜的烘烤工艺模式,研究不同烘烤温度与升温速度对 K326中上部烟叶烤后品质及等级结构的影响．结果表明,T2处理为最佳烘烤工艺,即中部烟叶变黄期温度39～42℃、湿球温度36℃;定色期以平均2 h 升温1℃的速度提高到温度55℃、湿球温度37～38℃;干筋期温度68℃、湿球温度40℃．上部烟叶变黄期温度38～42℃、湿球温度36℃;定色期温度47～55℃、湿球温度38℃;干筋期温度68℃、湿球温度41℃．T2处理的烟叶橘黄,油分多,身份适中,色度强;烟叶总糖、还原糖、烟碱含量适中,内在化学成分更加协调;感官质量香气量足,香气质细腻,烟气醇和度、舒适性最好;烟叶中上等烟比例、均价、正组烟叶比例提高．说明在烘烤过程中对温湿度及升温速度的调整是有效的,能有效改善烟叶内在品质,提高烟叶工业可用性．