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1.
最大摄氧量和心率在训练中已经被广泛采用,而运动员最大吸氧量时的心率或相应的心率所对应的心率研究较少,本文通过查阅资料对两者之间做相关性研究,使心率控制VO2max来提高训练水平的方法应用于运动员训练。 相似文献
2.
目的:研究氧气稀缺区的运动强度同内脏损伤关系。方法:选择某大学竞技体育学院运动员30名,受试者分别在常氧、模拟海拔1500、2500、3500 m低氧环境中,完成传递负荷功率自行车测试,探讨运动员最大摄氧量以及运动强度同内脏损伤的关系。结果:随着海拔高度的增加,运动心率呈现下降趋势;低氧环境下运动出现单峰值时,发生概率为50%的内脏轻度、中度和重度损伤的运动峰值,分别是66 N/次、116 N/次和180 N/次;随着运动强度的增加,引起同样程度运动强度所需的超强峰值逐渐降低。结论:低氧环境下,运动强度对人员内脏损伤的程度,主要同运动员最大摄氧量比例值,运动强度的峰值,运动持续时间有关,运动员最大摄氧量比例值越高,内脏损伤程度越低,运动强度峰值越高,内脏损伤的程度越高,运动持续时间越长,内脏损伤所需的运动强度值越低。 相似文献
3.
目的探讨阿托伐他汀钙对大鼠脑缺血再灌后脑组织中NF-kBp56及蛋白表达的影响。方法采用大脑中动脉线栓法制备局灶性脑缺血再灌注模型,参考onga的5分制法在大鼠麻醉清醒后进行评分。应用原位杂交和免疫化法检测NF-kBp56mRNA及蛋白表达。结果大鼠及缺血再灌注后缺血组织中NF-kBp56mRNA和蛋白表达增加（P＜0.01）.24h达高峰。给予阿托伐他汀钙干预后能减少缺血脑组织中NF-kBp56mRNA和蛋白表达（P＜0.05）,降低神经功能缺损评分（P＜0.05）。结论 阿托伐他汀钙能抑制大鼠及缺血再灌注后脑组织中NF-kBp56mRNA及蛋白表达。减轻缺血再灌损伤。 相似文献
4.
旨在量化分析有氧运动特别是中长跑运动对于不同运动群体的肺功能促进作用,并进行定量的研究和提取有用特征为后续研究所用。提出一种基于运动心肺试验的CPET(cardiopulmonary exercise testing)平台搭建方法,在长期检测的情况下,充分掌握了运动对不同性别不同群体身体机能改进程度。样本采集和数据分析中对心肺功能的肺活量、安静时心率、运动即时心率、恢复期心率以及最大摄氧量等参数进行有效提取,并对实验结果进行数据处理,结合信号特征提取的方法,有效提取了肺功能参数特别是最大摄氧量的谱分析特征。数据分析结果和特征提取结果量化了各项运动对肺功能CPET平台中各模块,为改善大学生心肺耐力水平相关体育科学和医学研究提供了科学依据。 相似文献
5.
目的:研究运动员稀氧区域训练对肌肉纤维耐久力的影响。方法:分析18名运动员在常氧和高原低氧(模拟海拔4500 m递增负荷运动时,低氧通气反应速率、最大摄氧量以及最大耐力持续时间三个肌肉纤维耐久力评估指标的变化情况。结果:高原低氧训练时运动员低氧通气速率和最大耐力持续时间显著高于常氧对应值,高原低氧训练时,运动员最大摄氧量低于常氧对照组。高原低氧训练组,运动员在4个不同功率等级低氧通气速率,均高于常氧对应值,低氧通气速率在50%、75%以及100%最大功率时显著高于常氧对应值,最大摄氧量在各相对功率等级中,无显著性差异。运动员的低氧通气反应速率在高原低氧训练组至75%最大功率阶段降低,在75%至100%最大功率阶段基本保持平稳上升,不同相对强度下低氧训练组运动员最大摄氧量较常氧对应值显著降低。结论:高原运动训练下运动员肌肉纤维耐久力增强,疲劳时间降低,可提高运动员的运动能力。 相似文献
6.
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
7.
目的 探讨苦参碱(Matrine,Mt.)对压力负荷性肥厚心肌TGF-β1的作用.方法 应用大鼠腹主动脉部分结扎,建立压力负荷性心肌肥厚模型.实验分四组进行,即手术组、假手术组、手术苦参碱组、手术卡维地洛(Car.)组.术后5周,观察左心室重量与体重之比(LVW/BW)、用免疫组化法查TGF-β1、以及用RT-PCR法查TGF-β1.结果 手术组与假手术组对照,LVW/BW增加;用免疫组化法查TGF-β1,蛋白表达增强;用RT-PCR法查TGF-β1,mRNA表达增强(P＜0.05).手术用药组与手术组比较,LVW/BW减小;用免疫组化法查TGF-β1,蛋白表达减少;用RT-PCR法查TGF-β1,mRNA表达减少(P＜0.05).结论 苦参碱具有减少压力负荷性心肌TGF-β1的作用. 相似文献
8.
目的:分析低氧环境下的训练对肌肉爆发力参数的影响。方法:随机选取某市某高校志愿者30名,将其随机分为低氧运动组和常氧运动组,低氧训练组的15位受试者在模拟青海地区海拔环境下进行训练。常氧训练组受试者进行常氧测试。两组受试者均进行相同强度的训练,对最大摄氧量、低氧通气速率、肌肉收缩产生某个运动关节屈伸扭转力矩、对抗肌比、相对平均功率等指标进行测试。结果:低氧训练组受试者最大摄氧量显著低于常氧训练组(P0.05),同时随着运动负荷的逐渐增加,最大摄氧量逐渐降低;两组受试者通气反应速率均随运动负荷的增大而显著增加。低氧训练组和常氧训练组相比,具有非常显著性差异(P0.01)。两组膝关节屈伸肌快速相对峰值力矩实验后均有非常显著性提高;伸肌快速相对峰值力矩增长量低氧训练组非常显著性高于常氧训练组,P0.01;屈肌组间相比,无显著性差异。结论:低氧环境下训练能够有效增强肌肉爆发力,对肌肉爆发力参数有积极的影响。 相似文献
9.
目的:采用跑台训练方式,建立大鼠运动模型,运用免疫组织化学SABC法研究不同负荷运动对大鼠海马CA1区Bax、Bcl-2表达的影响。方法:将大鼠分为对照组、中等强度运动组和大强度运动组,对大鼠进行为期5周的跑台训练,用免疫组化结合图像分析技术观察海马神经元中Bax、Bcl-2的免疫反应活性。结果:中等强度运动后,大鼠海马CA1区神经元Bcl-2蛋白的表达显著上升,Bax蛋白略微增加,Bax/Bcl-2显著下降。大强度运动后,大鼠海马CA1区神经元中Bcl-2蛋白的表达略微增加,Bax蛋白的表达显著增加,Bax/Bcl-2显著增高。结论:中等强度运动可促使Bcl-2蛋白的表达,使Bax/Bcl-2显著降低,抑制细胞凋亡;而大强度运动促进Bax蛋白的表达,使Bax/Bcl-2比例显著增加,促进细胞凋亡。 相似文献
10.
目的:研究磷酸化活对高原缺氧负重训练动脉供血调控促进模型,促进运动员的心肺功能,提高运动员的供血调控水平。方法:通过高原缺氧负重训练,产生大量的磷酸化活物,人体中的磷酸化活物重组质粒p ET-28a-Agr C在C43(DE3)中表达为末端苏氨酸物体,通过提取人体内的血液标本,进行样本测试,对采集的运动员血液样本进行蛋白脂质体先用膜不可渗透硫醇-非荧光试剂(4-acetamido-4'-maleidylstibene-2,2'-disulphonic acid,Amdi S)标记,得到采用磷酸化活测定分析高原缺氧负重训练下的动脉供血调控促进模型结构。结果:运动员心率HR和肺活量VC显著性差异P0.01,缺氧负重训练中最大摄氧量VO2max的值都要大于台阶实验数值,达到最大摄氧量VO2max,心率HR的显著性差异P0.01。得到的测试组TG的心肺功能由于对比组CG1和CG2的显著差异性,进而促进动脉供血调控。结论:采用磷酸化活测定方法对高原缺氧负重训练动脉供血调控促进模型进行分析建模,对促进运动员的心肺功能,提高运动员的供血调控水平具有帮助。 相似文献
11.
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
12.
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
13.
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
14.
《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
15.
《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
16.
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
17.
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
18.
Milton Mueller 《The Information Society》2001,17(3):151-163
Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP. 相似文献
19.
Prof. Raymond C.K. Chen a neuropsychologist with the CAS Institute of Psychology has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.…… 《中国科学院院刊(英文版)》2008,22(1):15-15
Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology. 相似文献
20.
Leah A. Lievrouw 《The Information Society》1998,14(2):83-96
The main premise of this article is that in information societies generally, and in virtual social contexts particularly, a distinctive style of interaction to facilitate the communication of difference, heterotopic communication , has emerged. It rests on two cultural foundations: an ideological belief in the positive, socially integrating power of communication, and a prevailing ethic of instrumental rationality, subjective individualism, and strategically practiced self-interest. The former is demonstrated by the use of simulation and spectacle as sources of information; exhibitionism/voyeurism as a communicative style; and the awareness of surveillance. The latter is seen in the competitive use of knowledge as a commodity; a surface globalism masking deep parochialism; lateral as well as vertical information inequity; and the use of public versus private as strategies for engagement rather than as spaces. Those who engage in heterotopic communication resort to their 'own devices' both in the sense of personal agendas, strategies, interests, and interpretations, and in the form of the telecommunication tools that help realize them. These personal and technological devices allow individuals with the right educational and technical resources to avoid exposure to disagreement, difference, or other information that does not serve their direct purposes or reflect their particular views of the world; yet they also help convey the appearance of openness, availability, and cooperation. This style of interaction is used strategically in combination with information and communication technologies to gain social or economic advantages, but it may encourage social separatism and parochialism, inhibit the negotiation of disputes, and emphasize competing interests. 相似文献