共查询到20条相似文献，搜索用时 62 毫秒
1.
《科技风》2021,(28)
目的:探讨有氧运动对高脂饮食肥胖大鼠胸主动脉血管eNOS mRNA表达水平及自由基代谢作用。方法:根据饮食结构不同将SD大鼠随机分为3组(n=10),正常饮食组(CN)、高脂蛋白组(HD)、高脂蛋白复合有氧运动组(HE),HE大鼠每天游泳1次,90min/次,每周运动5天,持续8周。取心肌及胸主动脉。检测SD大鼠体重,LEE’S指数,心肌中超氧化物歧化酶(SOD)、丙二醛(MDA),胸主动脉血管eNOS mRNA表达水平的影响。结果:与正常饮食组相比,高脂蛋白组心肌中的MDA含量升高,SOD含量降低(P0.01)。与高脂蛋白组相比,高脂蛋白复合有氧运动组心肌MDA含量降低,SOD含量增加(P0.01)。正常饮食组eNOS mRNA基因表达水平显著高于高脂蛋白组(P0.05),高脂蛋白复合有氧运动组eNOS mRNA基因表达水平高于高脂饮食组(P0.05)。结论:有氧运动可改善胸主动脉eNOS mRNA表达水平,其机制可能与增强抗氧化酶活力、减少自由基产生有关。 相似文献
2.
差异含氧量下的运动对心肌细胞代谢水平影响 总被引：1，自引：0，他引：1
目的:分析差异含氧量下运动对心肌细胞代谢水平的影响。方法:以大鼠不运动、高含氧运动训练、低含氧运动训练为运动模型,在训练前、后分别观察大鼠的情况,并检测其体重、心脏重量以及心系数的变化,用MDA和SOD试剂盒测试心肌组织中MDA含量和SOD活性,分析差异含氧量运动对大鼠心肌组织中脂质过氧化水平的影响。结果:同对照组大鼠对比,高含氧训练组大鼠体重降低(P0.01),心脏重量和心系数增加(P0.01),同对照组大鼠对比,低含氧训练组大鼠体重明显降低,心脏重量和心系数都显著提高(P0.01);同对照组对比,高含氧训练组LVSP、dp/dt max显著性下降(都是P0.01),LVEDP则显著性升高(P0.01);同高含氧训练组对比,低含氧训练组LVSP、dp/dt max显著性升高(都是P0.01),LVEDP则显著性下降,低含氧运动训练可造成大鼠心肌细胞中MDA含量明显增加,SOD活性显著下降(P0.01),高含氧运动训练未见大鼠心肌细胞MDA含量和SOD活性的显著变化。结论:低含氧运动造成的心肌细胞脂质过氧化水平降低,是过度训练引起心肌细胞代谢降低的机制之一。 相似文献
3.
《科技通报》2017,(10)
目的:研究长期高强度有氧训练对雄性大鼠跟腱粘弹性的影响。方法:选择雄性大鼠80只作为研究对象,随机将其划分成一次性跑台运动对照组、一次性跑台运动组、长期运动组和长期运动对照组,按照分组进行相应的训练。结果:一次性跑台运动对照组大鼠跟键组织主要由按顺应力方向排列整齐、结构致密的胶原纤维组成,胶原原纤维存在典型周期性横纹。一次性跑台运动组大鼠跟键局部胶原纤维之间的间隔变大,局部排列错乱。长期运动组大鼠跟腱组织胶原纤维排列较规则,粗细均匀,胶原纤维排列紧密。长期运动对照组大鼠胶原纤维排列紊乱,粗细不均,有部分出现断裂,胶原纤维较少。长期运动组大鼠刚度和最大载荷非常显著性高于长期运动对照组大鼠(P0.01),能量吸收显著高于长期运动对照组大鼠(P0.05)。一次性跑台运动组与一次性跑台运动对照组跟腱水含量、跟腱重量、羟脯氨酸无显著性差异(P0.05);长期运动组大鼠跟腱水含量、跟腱重量、羟脯氨酸与长期运动对照组大鼠相比无显著性差异(P0.05)。一次性跑台运动组PⅠNP显著高于一次性跑台运动对照组(P0.05),PⅢNP非常显著性高于一次性跑台运动对照组(P0.01)。长期运动组PⅠNP和colⅠα1非常显著性高于长期运动对照组(P0.01)。结论:长期高强度有氧训练能够增强雄性大鼠跟腱粘弹性。 相似文献
4.
目的:以心肌mTOR信号、静态心率以及心肌变力变化趋势为分析基础,对高强度运动下大鼠心肌变力衰弱情况进行分析。方法:以雄性SD大鼠为研究对象,将其划分成对照组、中等运动组以及高强度运动组,对运动组大鼠进行递增负荷跑台训练,共进行5周。在末次运动后即刻、5 h、10 h以及20 h,分别取大鼠左心室心肌和血液。检测实验大鼠心肌mTOR的蛋白表达。将实验运动组大鼠S1幅值对安静组大鼠S1幅值增加的相应倍数定义为心肌变力变化趋势。结果:高强度组大鼠的心脏重量显著低于中等强度组和对照组。中等强度组大鼠心肌mTOR在运动后10 h达到峰值,高强度运动组大鼠心肌mTOR在运动后5 h达到峰值。高强度组大鼠心肌变力变化情况显著高于中等强度组。高强度运动组的大鼠心率对安静时心率以及心肌变力变化趋势都低于安静组以及中等强度组。结论:心肌变力随着运动强度增大而增加,长期高强度运动下心肌变力mTOR信号未被激活,导致静态心率以及心肌变力变化趋势减弱,导致严重的心肌变力衰弱,使得心肌损伤向病历性发展的风险。 相似文献
5.
目的:分析强污染下运动对心肺功能的影响。方法:选取某市某校大学生志愿者60名,其中男生30名,女生30名,将其随机划分成四组,分别为强污染运动组、强污染对照组、低污染运动组、低污染对照组,每组20人,强污染运动组在强污染环境下进行Bruce方案,强污染对照组不进行运动,但与强污染运动组共同处于强污染环境下,低污染对照组不进行运动,但处于低污染环境下。结果:强污染运动组的安静心率、收缩压、舒张压、脉搏压、心功指数均高于强污染对照组与低污染对照组,且安静心率、脉搏压、心功指数与低污染对照组相比具有显著性差异(P0.05),与强污染对照组相比具有非常显著性差异(P0.01);收缩压与强污染对照组相比具有显著性差异(P0.05)。强污染运动组ESD、EDD、ESV、EDV、MSER以及MVCF均高于强污染对照组和低污染对照组,其中EDV与MVCF和低污染对照组相比,具有显著性差异(P0.05);EDV、MSER与强污染对照组相比,具有显著性差异(P0.05);MVCF与强污染对照组相比具有非常显著性差异(P0.01)。强污染运动组实验后FVC、FEV1、FEF25%-75%、FEF与实验前相比明显增加,且具有非常显著性差异(P0.01);MVV较实验后明显降低,且具有非常显著性差异(P0.01),而强污染对照组与低污染对照组实验前后均无显著性差异。结论:强污染运动下,运动对改善和提高心肺功能具有非常积极的作用。 相似文献
6.
目的:分析长期有氧运动对肥胖人群血脂调节的影响。方法:按照世界卫生组织(WHO)提供的肥胖标准,在某市某学校中选取30名肥胖大学生,将实验对象随机划分成实验组与对照组,各15名。实验组按照训练方法进行15周的有氧训练,同时在第一次和最后依次运动后立即对静脉血测血脂、血胰岛素、皮质醇等生化指标进行测试,另一组作对照,分别在15周前后对两组受试者的体成分、血脂、胰岛素、瘦素进行测试。结果:经15周有氧训练后,实验组体重、体重指数、体脂百分比、体脂含量均显著下降,(P0.05或P0.01),显著低于对照组(P0.05或P0.01),而取值体重略有增高。实验组血清TG、TC、LDL含量显著下降(P0.05或P0.01),HDL含量显著增加(P0.05);和对照组相比,血清TG、TC、LDL含量显著降低(P0.05或P0.01),HDL含量显著升高(P0.05)。实验组血胰岛素水平显著下降,和对照组相比显著降低(P0.01);实验组瘦素水平明显下降,和对照组相比显著降低(P0.05)。结论:长期有氧运动能够促进脂肪的分解代谢,使得血脂中各成分比例更有利于健康,调节肥胖人群内分泌,有助于减肥与身体健康。 相似文献
7.
目的:分析高海拔运动下负载量同内分泌紊乱关系。方法:通过低压低氧舱模拟海拔5000 m高原低氧环境复制动物模型,将小鼠划分成常氧对照组以及低氧组:低负载量、中负载量以及高负载量组。测定小鼠血清游离三碘甲腺原氨酸FT3和促甲状腺激素FT3水平,分析高海拔运动下负载量逐渐增加过程中小鼠内分泌指标变、小鼠血浆中雌二醇水平,小鼠身体做功能力以及最大耗氧量情况。结果:随着低氧运动负载量的不断增加,低氧运动组小鼠体重都显著低于对照组,与常氧对照组对比,低氧运动的血清果酮下降(P0.05),低氧中负载运动(P0.01)和低氧高负载运动(P0.05)血清皮质醇呈现下降趋势,T/C在低氧低、中、高负载量(P0.05、P0.01、P0.05)较常氧对照组显著升高,低氧运动组小鼠血清下丘脑-垂体-游离三碘甲腺原氨酸FT3和促甲状腺激素TSH不断降低,并且运动负载量越大,小鼠FT3和TSH越低,运动后小鼠血浆雌二醇水平均较运动前显著降低(P0.01或P0.05)并且随着运动负载量的增加,低氧运动组小鼠的血浆雌二醇水平呈现下降趋势。小鼠机体出现适应变化、机体做功能力以及最大耗氧量都降低。结论:说明高海拔低氧运动下,运动员的运动负载量越高,其机体内分泌各指标值越低,内分泌系统活力大大降低,小鼠内分泌的紊乱程度增大,使得小鼠机体功能大大减弱。 相似文献
8.
本文研究运动训练对肥胖大鼠腹内脂肪、血压和蛋白尿的影响。通过高脂膳食进行肥胖造模。随机将SD大鼠分为4组：安静对照组、运动对照组、安静肥胖组、运动肥胖组（对四组大鼠进行3月跑台训练,其中Sed-Ob=安静肥胖组,Ex-Ob=运动肥胖组,Sed-C=安静对照组,和Ex-C=运动对照组）。对大鼠腹内脂肪含量、肌酐,蛋白尿、血压进行实验研究。结果表明：安静对照组的大鼠血压正常,而安静肥胖组大鼠血压高;经过1月的锻炼运动肥胖组血压下降。运动训练组的体重和腹膜后脂肪量低于安静对照组。安静肥胖组尿蛋白排泄量明显高于安静对照组。目前的研究结果使我们得出这样的结论：运动训练可以降低饮食诱导的肥胖大鼠腹内脂肪含量、血压和蛋白尿。 相似文献
9.
目的:分析小鼠过度运动状态下内分泌症状特征。方法:将小鼠随机分成空白对照组、常规运动组、过度运动组三组,每组各10只,空白对照组每天无任何特殊运动,正常饲养,过度运动组小鼠进行过度训练,常规运动组小鼠在与过度运动组相同的游泳箱中每天进行30 min的游泳训练,持续7 d,测定心系数、收缩压、心率、血浆心钠索、ET、Ang、NO、NOS等指标。结果:和对照组相比,常规运动组和过度运动组小鼠的心脏系数/体重指数变化具有显著性统计学意义。运动后常规运动组和过度运动组的平均血浆心钠素水平均非常显著高于运动前,运动前后常规运动组的平均血浆心钠素量也分别显著高于过度运动组。与对照组相比,常规运动组ET具有显著性差异,Ang具有极显著性差异,过度运动组的Ang显著低于常规运动组。常规运动组与过度运动组与对照组相比,NO、NOS活性均有非常显著性差异,过度运动组小鼠NO活性显著低于常规运动组小鼠,过度运动组小鼠NOS活性低于常规运动组小鼠,但无显著性差异。结论:过度运动状态下,小鼠体内分泌各指标值降低,内分泌系统活力大大降低,紊乱程度增大,使得小鼠机体功能大大减弱。 相似文献
10.
研究目的：探讨葡萄籽提取物原花青素（procyanidins）对抗疲劳的效果,选用纯系雄性C57BL／6J小鼠40只,体重为22-28g,观察原花青素对小鼠游泳力竭时间的影响。将40只小鼠随机分成4组,每组10只,其中对照组和实验组各2组。对照组包括安静和运动各1组,安静组（C1）在力竭游泳测试前30min给予等量生理盐水,运动组（C2）在2h游泳运动后30min给予等量生理盐水。实验组包括安静＋给药和运动＋给药各1组,安静＋给药组（T1）在力竭游泳测试前30min给予等量原花青素水解液,运动＋给药组（T2）在2h游泳运动后30min给予等量原花青素水解液。经口灌胃给药,给药剂量为50mg／kgBw溶解于0．8ml生理超纯水中。测定小鼠的游泳的力竭时间,来判断花青素是否对小鼠的运动具有抗疲劳作用。结果显示,原花青素给药组小鼠负重游泳时间均比对照组延长,且运动后给药组游泳力竭时间显著高于运动后给生理盐水组（p〈0.01）。结论：本实验研究结果表明原花青素不仅具有抗疲劳作用而且具有促进运动后疲劳恢复的作用。 相似文献
11.
A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
12.
Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
13.
A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
14.
Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
15.
Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
16.
《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
17.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
18.
《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
19.
Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
20.
Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献