大鼠过度运动状态下内分泌症状特征研究分析

目的:分析过度运动状态下SD大鼠心血管内分泌症状特征。方法:选择雄性SD大鼠40只,依据体重随机划分成安静对照组、中等过度运动组、强过度运动组以及力竭运动组,对于运动组的大鼠,需每天在跑台上完成不同程度的8周过度运动训练,采用仿射免疫法测定大鼠心机细胞中内皮素ET、血管紧张素AGTⅡ、心机细胞膜上受体ETR等内分泌症状特征的变化情况。结果:强过度运动组大鼠的AGTⅡ含量均显著低于安静组(P0.01),力竭运动组大鼠的AGTⅡ含量与安静组无显著性差异;强过度运动组大鼠的ET含量均显著低于安静组大鼠(P0.01);力竭运动组大鼠和中等过度运动组的ET含量和安静组相比并无显著性差异;强过度运动组大鼠的ETR值显著增加(P0.05),力竭运动组大鼠的ETR值显著降低(P0.01);各运动组大鼠的ANP含量和安静组相比均显著增高(P0.05、P0.01),力竭运动组大鼠的ANP含量比安静组显著降低(P0.05)。结论:中等过度运动可明显改善内分泌功能,而过度运动阻碍内分泌系统的功能。     

β-烟酰胺单核苷酸(NMN)对自然老化小鼠免疫力与精神状态的影响

目的:研究β-烟酰胺单核苷酸(NMN)对自然老化小鼠免疫力与精神状态的影响。方法:将20只6月龄ICR小鼠分为对照组与NMN组,正常饲养6个月后NMN组连续灌胃给药60 d。末次给药24 h后各组别进行自发活动与强迫游泳实验,之后小鼠眼内眦取血进行血细胞分析,颈椎脱臼处死动物,取胸腺与脾脏称重,计算器官指数。结果:NMN组较对照组小鼠体重、胸腺及脾脏指数无显著性差异。血细胞检测中,各指标无显著性差异。自发活动分析结果显示NMN组小鼠5 min内运动总路程与运动时间百分比较对照组有极显著增高(P<0.01)。强迫游泳实验结果中,NMN组小鼠不动时间较对照组有极显著性降低(P<0.01)。结论:NMN对自然老化小鼠的免疫无显著影响,但具有一定改善焦虑与提高活跃度的药效作用。     

灯盏花素抗小鼠运动性疲劳的实验研究

目的:探讨灯盏花素抗运动性疲劳的作用。方法:60只小鼠随机分为正常对照组、运动对照组、低、高剂量灯盏花素四组。灯盏花素组每天灯盏花素灌胃,对照组给予等量生理盐水。10天后,检测小鼠负重游泳时间和常压耐缺氧时间。结果:与运动对照组比较,灯盏花素低、高剂量组小鼠负重游泳时间显著延长;与正常对照组比较,灯盏花素低、高剂量组小鼠常压耐缺氧时间显著延长。结论:灯盏花素具有抗小鼠运动性疲劳的作用。     

周期有氧运动下肥胖小鼠心肌收缩模型分析

目的:分析周期有氧运动下肥胖小鼠心肌收缩能力。方法:选取肥胖昆明小鼠12只,正常昆明小鼠12只为对照组,无负重游泳训练8周(每周5天,每天2小时),构建周期有氧运动训练模型。采用单心肌细胞边缘探测系统检测各组小鼠心肌收缩能力。通过蛋白免疫印迹法检测心肌细胞自噬蛋白的表达。结果:正常对照组小鼠摄食量同肥胖组小鼠没有差异,肥胖组小鼠摄入的能量高于正常对照组,肥胖组小鼠在运动期间体重增长率显著高于正常对照组(P0.01)。周期有氧运动训练能够有效改善肥胖小鼠心肌收缩能力,显著增加肥胖组小鼠心肌最大收缩幅度以及最大收缩速率(±dL/dt),延长心肌收缩时程(均P0.05),上调肥胖心肌激活的蛋白激酶(AMPK)磷酸化的水平。检测心肌自噬标志物Beclin-1以及Atg7发现,同正常组对比,肥胖组小鼠心肌自噬水平显著降低(P0.05)。结论:周期有氧运动可促进肥胖组小鼠代谢水平,有效上调肥胖小鼠心肌收缩自噬的水平,改善肥胖小鼠心肌收缩能力。     

差异含氧量下的运动对心肌细胞代谢水平影响

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。     

高强度有氧训练对运动员组织自由基代谢的影响分析

目的:研究高强度有氧训练对运动员组织自由基代谢的影响。方法:随机选择某市某体育院校田径队中长跑组二级以上的30名运动员作为研究对象。将其随机划分成高强度有氧训练组和对照组,两组运动员分别按照各自的训练方案进行训练。结果:在高强度有氧训练后,高强度有氧训练组,肝、肾组织的SOD含量和对照组差别不大;心组织的SOD含量与对照组相比显著增大;血清的SOD含量与对照组相比非常显著性增大。高强度有氧运动组肾组织CAT含量高于对照组,但无显著性差异;心、肝组织及血清CAT含量与对照组相比具有非常显著性差异。高强度有氧运动组,心组织和血清中T-AOC含量与对照组相比无统计学意义;肾组织T-AOC含量与对照组相比显著增高;肝组织T-AOC含量与对照组相比呈非常显著性增高。高强度有氧运动组心组织中的MDA含量与对照组相比有所增大;肝、肾组织及血清中的MDA含量较对照组而言有非常显著性差异。高强度有氧运动组血清中CK、BU含量均非常显著高于对照组。高强度有氧运动组心、肝和血清SOD/MDA与对照组相比有非常显著性差异;肾组织与对照组相比无统计学意义。高强度有氧运动组心、肝、肾组织T-AOC/MDA与对照组相比显著升高;血清T-AOC/MDA无统计学意义。结论:高强度有氧训练组运动员阻止自由基代谢能力优于对照组。     

有氧运动对肥胖者儿童的体脂比消耗影响的分析

目的:研究有氧运动对肥胖者儿童体脂比消耗的影响。方法:实验组运动时专业技术人员采用POLAR表对受试者的运动心率进行监控,使其控制在心率储备的20%~40%范围内,保证运动强度在有氧运动范围内。实验组每天运动3次,每次1 h,共进行5周有氧训练,运动前后各进行10~20 min的准备活动。对照组不进行有氧运动。结果:实验组体重、体重指数、体脂比、体脂含量实验后与实验前相比,实验组与对照组相比显著降低。TG实验组实验后与实验前相比,实验组与对照组相比显著降低;TC实验组实验后与实验前相比,实验组与对照组相比,均非常显著性降低,对照组实验前与试验后相比,显著性降低;HDL实验组与对照组相比,显著增加;LDL实验组实验后与实验前相比显著降低。TG、FIN、FBG末次与安静时相比,末次与首次相比,均显著降低;HDL、LDL末次与安静时相比,末次与首次相比,均有非常显著性差异;TC末次与安静时相比,显著降低,末次与首次相比非常显著性降低。Ins实验后与实验前相比,实验组与对照组相比均非常显性降低;Cor实验后与实验前相比,实验组与对照组相比均显著降低。Ins末次与安静时和首次相比,均非常显著性降低。结论:有氧运动能够增加肥胖者儿童的体脂比消耗。     

羊肚菌对大强度耐力训练大鼠骨骼肌自由基代谢的影响

建立大鼠大强度耐力训练模型,研究羊肚菌对大强度耐力训练大鼠自由基代谢和运动能力的影响。测定了大鼠骨骼肌组织中SOD、GSH-Px、CAT三种抗氧化酶活性和脂质过氧化产物MDA含量,也测定了大强度耐力训练大鼠的力竭时间。结果表明：同运动对照组相比较,运动加药组大鼠骨骼肌抗氧化酶SOD、GSH-Px、CAT活性有显著性或极显著性上升,MDA含量有显著性下降,同时运动加药组大鼠力竭时间与运动对照组相比显著延长,表明在大强度耐力训练大鼠骨骼肌自由基代谢当中,补充羊肚菌发挥着良好的清除自由基和抗氧化效果。     

古法炮制多花黄精提取物抗疲劳作用研究及其机制探讨

目的:研究多花黄精的古法炮制方法及古法炮制多花黄精的抗疲劳作用。方法:将雄性ICR小鼠随机分为空白对照组(给予蒸馏水),市售黄精提取液阳性对照组(16 g/kg),古法炮制黄精提取液低(4 g/kg)、中(8 g/kg)、高(16 g/kg)剂量组,连续灌胃给药30 d。考察古法炮制多花黄精对小鼠负重游泳时间、游泳后血清尿素氮水平、肝糖原含量及游泳前后血乳酸水平的变化。结果:古法炮制黄精多糖提取液可以显著提高小鼠游泳时间、降低游泳后血清尿素氮水平、提高肝糖原含量、降低游泳后血乳酸水平并加快游泳后血乳酸降解。并与同剂量市售黄精组相比有显著提高(P0.05)。结论:古法炮制多花黄精提取液具有显著抗疲劳作用,且抗疲劳效果比市售黄精提取液更佳。     

长期高强度有氧训练对雄性大鼠跟腱粘弹性的影响

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。     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

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.     

Cooler temperatures inductive to locust outbreaks

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.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

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.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

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.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

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.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

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.     

Prevalence of soft neurological signs in Chinese people

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.     

Our Own Devices: Heterotopic Communication, Discourse, and Culture in the Information Society 1

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.     

Monoculture Rubber Plantations Have Negative Ef ects on Controlling Splash Erosion

<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence     

Chinese Scientists Use Earth Observation Technologies to Study and Protect Wild Camels

<正>Chinese scientists plan to apply Earth Observation technologies to protect the critically endangered wild camels(Camelus ferus).With the help of remote sensing,satellite positioning,geographical information system and wireless sensors networks,they will be able to access the distribution and population of the wild camels and protect their habitats.The project will be carried out by the International Research Center for Wild Camel Conservation,which was jointly established earlier this year by the Institute of Remote Sensing and Digital Earth(RADI)of the Chinese