Oxygen free radical modified DNA: Implications in the etiopathogenesis of Systemic lupus erythematosus     

Saba Khan  Roshan Alam  Moinuddin  Asif Ali 《Indian journal of clinical biochemistry : IJCB》2009,24(2):123-130

The present study was designed to probe the possible role of singlet oxygen and superoxide anion radical modified DNA in the etiopathogenesis of Systemic lupus erythematosus. These species were generated by the exposure of riboflavin to 365 nm UV light. Modified DNA showed single strand breaks, hyperchromicity at 260nm and decrease in Tm. The modified DNA induced high titer antibodies in experimental animals. The antibodies showed reactivity with various nucleic acid polymers, a property commonly associated with Systemic lupus erythematosus anti-DNA autoantibodies. Systemic lupus erythematosus sera showed preferential binding of modified DNA over native DNA in direct binding and competitive binding solid phase immunoassays and band shift assays. The results suggest for the possible involvement of the singlet- superoxide modified DNA as a potential trigger for anti- DNA autoantibody production in SLE and thus in the etiopathogenesis of the disease.  相似文献   

欠驱动漂浮基空间多体系统的递推动力学     

邵兵  吴洪涛  程世利 《中国科学院研究生院学报》2009,26(5):609-614

针对欠驱动漂浮基空间多体系统,将欠驱动关节分解为主动和被动关节,研究用李群和李代数表示其动力学问题.将牛顿-欧拉反向动力学方法推广到适合于含主被动关节的形式,同时得到了漂浮基空间多体系统的主被动关节递推动力学建模方法.该方法可以用于对链式、树形拓扑结构的空间系统建模,也可用于对采用有限段方法建立的柔性梁式构件的离散模型进行高效率递推计算.结果表明,用李群李代数理论中的方法和符号更有助于形成递推的高效动力学建模,得到的动力学公式简明、清晰.  相似文献   

基于无标度网络的虚拟企业知识协作创造研究     

马如宏  成桂芳 《现代情报》2009,29(3):188-191

提出了虚拟企业知识协作创造的概念,并在修正的知识创造模型SECP以及虚拟企业知识协作创造无标度网络的基础上建立了基于无标度网络的虚拟企业知识协作创造模型,该模型有效的克服了虚拟企业在知识协作创造方面面临的两大难题．即地域的广泛性和协作的低效性。  相似文献   

人物·思想·时代——《蒋廷黻社会政治思想研究》读后     

肖良武 《贵阳师范高等专科学校学报》2009,4(3):106-108

20世纪30、40年代中国社会出现了一批自由知识分子,他们对国际国内政局情势发表了自已的见解,特别是当时有一位特殊的历史人物——蒋廷黻,他起家于学术,兼跨行政、外交等诸般领域,相当程度上代表了当时一批自由知识分子的思想意向。在短短几十年间,这些博雅通达之士因应时势,成为民国政治舞台上军人集团外一支不容忽视的政治力量,在近代中国政治发展史上占据相当重要的地位。张玉龙博士的《蒋廷黻社会政治思想研究》的问世,某种程度上可以说是弥补了蒋廷黻学者从政以后的思想演变、政治实践及二者间的互动研究的缺陷。  相似文献   

花样滑冰跳跃动作起跳与落地运动生物力学研究   总被引：2，自引：0，他引：2  

纪仲秋  高芸  姜桂萍 《北京体育大学学报》2009,32(3)

采用艾立尔系统和三维DLT方法,对世界花样滑冰大奖赛上我国运动员及世界选手的跳跃动作进行了定点三维测试,比较分析他们在完成跳跃动作的起跳和落地相关参数,结果发现我国女运动员起跳时水平速度与国外优秀选手还有差距,起跳应积极蹬伸,形成好的小摆臂,早收手臂.  相似文献   

丝瓜、黄瓜、苦瓜抗氧化作用的初步研究   总被引：3，自引：0，他引：3  

王绪英  刘小玉 《六盘水师范高等专科学校学报》2009,21(6):41-43

采用分光光度法测定苦瓜、黄瓜和丝瓜的乙醇提取液对羟自由基和超氧阴离子自由基的清除作用,同时用碘量法研究它们对猪油的抗氧化性作用,研究发现：黄瓜肉对羟基自由基和超氧阴离子自由基的清除率均高于黄瓜皮,苦瓜肉对羟基自由基和超氧阴离子自由基的清除率高于苦瓜子,丝瓜皮对羟基自由基的清除率和对超氧阴离子的清除率均高于黄瓜皮;这三种植物对猪油均有一定的抗氧化能力。  相似文献   

The longitudinal relationship between generalized self-efficacy and physical activity in school-aged children     

Yao-Chuen Li  Divya Joshi  Sara King-Dowling  John Hay  Brent E. Faught 《European Journal of Sport Science》2018,18(4):569-578

Our understanding of the longitudinal relationship between generalized self-efficacy (GSE) and physical activity in children and youth is limited. The purpose of this study was to investigate the effect of GSE towards physical activity on sedentary behaviours and physical activity in school-aged children over time. A total of 2278 nine-year-old children (1120 girls and 1158 boys) were recruited at baseline and followed for seven waves of data collection from 2005 to 2008. All children completed questionnaires at each wave assessing their GSE (adequacy, predilection, and enjoyment), sedentary behaviours, free play, and organized activity. Mixed-effects models were used to estimate changes in physical activity and GSE within individuals over time, controlling for gender and motor ability. The results showed that participation in free play significantly increased over time, whereas organized activity significantly decreased over the same period. Children with high perceived adequacy and predilection had higher free play and organized activity participation relative to other children over time. However, the effect of perceived adequacy diminished over time, while the gaps between groups with different levels of predilection widened over time. While sedentary behaviours were lower over time in children with high predilection, these behaviours were consistently higher in children with high enjoyment. The differences in sedentary behaviours between groups increased over time for both predilection and enjoyment. This study highlights the importance of different components of GSE on physical activity participation. In addition, interventions targeting the enhancement of predilection may facilitate physical activity and reduce sedentary behaviours.  相似文献   

Effects of Aerobic Exercise on Cognitive Performance Among Young Adults in a Higher Education Setting     

Sebastian Ludyga  Markus Gerber  Serge Brand  Uwe Pühse  Flora Colledge 《Research quarterly for exercise and sport》2018,89(2):164-172

Purpose: Acute benefits of aerobic exercise on executive functioning have been reported frequently under laboratory conditions. However, to date, a beneficial effect on long-term memory has been less well supported and no data are available regarding nonlaboratory conditions in young adults. The aim of the current study was to investigate acute effects of aerobic exercise on cognitive functioning in a university classroom setting. Method: Using a cross-over design, 51 participants performed a bout of moderately intense running (RUN) and read an article while seated (CON). Afterwards, they completed free-recall tests, followed by a Flanker task and an n-back task. Results: Participants in the RUN condition compared with those in the CON condition showed shorter reaction time on the inhibition task, F(1, 50) = 5.59, p = .022, η² = .101, and recalled more words in the immediate- and delayed-recall tests, F(1, 50) = 8.40, p = .006, η² = .144. Conclusion: The present findings suggest that a moderately intense bout of aerobic exercise benefits verbal short-term and long-term memory as well as inhibitory control among students in a classroom setting.  相似文献   

网络上科学信息的时效性测量   总被引：3，自引：0，他引：3  

陈传夫  唐琼  于媛  吴志强  黄璇  陈松  李墨? 《情报学报》2009,28(4)

时效性是影响网上信息质量的重要因素.本文以网上可公共获取的科学信息为对象,采用层次分析法分配信息时效性各测量指标的权重,选择数学、生命科学、物理、材料科学等8个学科门类的32个主题词进行跟踪查询,抽取Google、Yahoo和Altavista搜索引擎返回的前50个页面作为测量样本.测量结果为:网络科学信息时效性的平均得分为2.6482(总体样本2814个),仅有34.90%的网页时效性得分高于平均值.不同域名中,.gov测量结果最好;在不同资源类型方面,虚拟研究社区与博客的时效性最好.然而,时效性只是网络信息的质量特征之一,并不能仅仅根据时效性判断信息的质量.总的说来,网络科学信息的时效性有待提高.本研究中提出的时效性测评框架及方法有利于帮助研究人员和公众在查询信息时对其时效性作出初步判断.  相似文献   

生存的困惑——解读《第二十二条军规》中海勒对于人类生存困境的反思     

张莉 《培训与研究》2009,26(1):30-32

在《第二十二条军规》中,约瑟夫.海勒展示了一个非理性的世界,并且通过对约塞连为求生所做的挣扎和其他人物在面对这一疯狂世界的各种反应的描写,表现出他对一个问题的思考,那就是当人类的存在境况变得彻底的荒诞时,人该怎么生活下去。本文试图以存在主义为视角,探讨小说中所表现出的人类生存困境和海勒对于该问题的反思。  相似文献