PI3K阻断剂对大鼠运动骨骼肌Akt/mTOR信号的影响

目的:通过阻断PI3K信号,以深入探讨Akt/mTOR通路在抗阻运动中骨骼肌蛋白合成的作用。方法:8周龄雄性SD大鼠在适应性训练后分为4组:安静组(S)、阻断剂组(SL)、运动组(E)、运动+阻断剂组(EL),每组6只。运动方式为跑台运动(坡度为10%,跑速20 m/min,60 min),每天1次,共7 d。腹腔注射外源性LY294002(剂量为5.5 mg/kg)。用Western Blotting法检测腓肠肌MHC、Akt和mTOR蛋白表达、Akt(Ser473)和mTOR(Ser2448)磷酸化表达。结果:在一周后,LY294002明显抑制MHC,运动有促进的趋势,并减弱LY294002对MHC的抑制效应。LY294002显著抑制Akt和mTOR蛋白表达、Akt(Ser473)和mTOR(Ser2448)的磷酸化表达,而运动明显增强mTOR、Akt(Ser473)和mTOR(Ser2448)表达。结论:1)阻断PI3K信号可使运动骨骼肌Akt/mTOR通路受到明显抑制,而同时骨骼肌MHC明显降低,明显抑制肌肉蛋白合成。2)运动明显促进该通路的表达,并减弱PI3K阻断剂对该通路的抑制效应。3)PI3K阻...     

骨骼肌抗氧化作用的信号转导机制

现已证明骨骼肌收缩诱导产生的活性氧（ROS）可造成骨骼肌氧化应激水平升高,同时肌肉的抗氧化防御系统的应答性也升高。而NFκB和MAPK是两条主要的氧化应激敏感性信号转导通路,可激活许多酶和蛋白质的基因表达,而这些酶和蛋白质在维持细胞内氧化还原稳态中发挥重要作用。综述讨论上述两条信号转导通路及其适应的生物学差异。     

Enhancive effect of N,N′-dinitrosopiperazine on inducing precancerous lesion on nasal and/or nasopharyngeal epithelia of TgN(p53mt-LMP1)/HT mice

Objective  To investigate the enhancive effect of N,N′-dinitrosopiperazine (DNP) on induced carcinogenesis in nasal and/or nasopharyngeal epithelia among TgN(p53mt-LMP1)/HT transgenic mice to examine the underlying mechanism for the development of nasopharyngeal carcinoma (NPC). Methods  TgN(p53mt-LMP1)/HT transgenic mice and the same strain of C₅₇BL/6J wild-type mice both at the age of 5 months were randomly divided into 2 groups in parallel, respectively, i.e., TgN(p53mt-LMP1)/HT cancerous lesion-inducing group (TI), TgN(p53mt-LMP1)/HT control group (TC), C₅₇BL/6J cancerous lesion-inducing group (CI), and C₅₇BL/6J control group (CC). TI and CI mice were treated only with DNP for 16 weeks, twice each week, while TC and CC mice were given the same volume of saline as controls. At the end of treatment, animals were sacrificed to collect epithelial tissue samples from nasal cavity and nasopharynx for pathohistological evaluation by haematoxylin and eosin (HE) staining and for determination on the expression of TRAF2, c-Jun, and p16 by immunohistochemistry. Results  Atypical hyperplasia was more significant in the samples of TI than in those of TC, CI, and CC, with the rates of lesions being 90%, 10%, 0, and 0 (P<0.01) respectively, though DNP was used alone in a much shortened inducing period at less dosage and without the use of carcinogenic promoter 12-O-tetradecanoylphorbol-13-acetate as usual. The expressions of tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) and c-Jun in these samples were significantly up-regulated in TI (P<0.01), while the expression of p16 was significantly lower in TI than in the other groups (P<0.01). Conclusion  TgN(p53mt-LMP1)/HT mice hold inherited constitutional defect in immune surveillance function, which can be aggravated by environmental carcinogens, such as DNP used even though in a much less strength. The enhanced carcinogenesis-inducing effect of DNP on TgN(p53mt-LMP1)/HT mice should be closely associated with abnormal signaling of activator protein-1 (AP-1) pathway, especially up-regulated expressions of TRAF2 and c-Jun, and down-regulated expression of p16. Project supported by the National Natural Science Foundation of China (Nos. 30672738, 30572455 and 30572408), Hunan Provincial Natural Science Foundation for Distinguished Young Scholars (No. 03JJY1006) and for General Projects (Nos. 05JJ40029 and 07JJ6038), the Research Foundation of Hunan Provincial Scientific and Technological Department for International Cooperative Academic Projects (No. 06WK3016), and the Research Foundation of Hunan Provincial Education Department for Outstanding Young Scholars (No. 06B070), China     

环境保护在构建和谐社会中的地位与路径选择

构建和谐社会是我国社会主义建设的重要目标,人与自然和谐是其中的重要因素,体现了和谐社会建设对环境保护的要求。为了分析和谐社会中蕴涵的环境保护要素,需要构建一个和谐社会与环境保护的概念模型。这个概念模型包含环境保护与五个主流领域的融合与交叉,即在和谐社会的大框架下,环境保护在这五个领域内的集中体现。一是在环境与政治领域,和谐社会就是要求将生态文明作为一种治国理念;二是在环境与健康领域,就是要将环境问题上升到基本民生问题,体现以人为本的原则;三是在环境与社会领域,就是要保护环境,维护社会公平与正义,维护公众权益;四是在环境与经济领域,要推动环境与经济的高度融合,以环境优化发展;五是要将环境问题放在全球化的背景下来考虑,推动国际环境公平与和谐世界的建立。     

和谐农村社会建设背景下节庆体育发展途径

节庆体育是我国农村社会体育活动的主要内容和形式,对当代和谐农村社会的建设有特殊的价值和影响,从正功能上看,节庆体育能促进农村和城市和谐发展、促进农村社会的村际关系和谐发展、促进农村社会人与自然和谐发展.但是,节庆体育作为我国传统民族文化的内容,难免存在一些影响和谐农村社会建设的消极因素,同时也存在一些不利于自身发展的不利因素.因此,研究节庆体育对和谐农村社会建设的影响,探索节庆体育的发展途径,无论是对节庆体育的继承发展,还是对和谐农村社会的建设都具有历史意义和现实意义.     

科研成果在职称晋升中的信号与甄别作用研究

在学术水平不可验证的背景下,以科研成果的数量作为主要绩效依据的职称晋升能否有效分离不同学术水平的科学家并促进学术创新是学术评价制度有效性的一个重要体现。本文基于信息不对称理论的研究框架分析了科研成果的不可验证特征对职称晋升的影响。在此基础上,本文以1338名公共农业科研机构科学家为样本并利用信号理论和probit模型对职称晋升中科研成果的数量能否区分学术水平和学术创新努力不同的科学家进行了证实。理论分析与计量经济学研究结果表明:不可验证性使科研成果的学术水平不适合作为职称晋升的依据;在我国现行职称晋升制度下,科研成果的数量主要是科学家能否晋升职称的信号而非甄别其学术水平和学术创新性的有效方式。     

对职业教育发展途径的分析

大力发展职业教育是解决我国经济社会瓶颈问题的有效措施。分析职业教育发展的途径,为职业教育的发展创造良好的社会氛围,使职业教育成为我国经济社会发展的重要支撑点,具有重大的理论和现实意义。     

谈效益理念在高校德育中的应用

改革和创新已成为高校德育理论和实践发展的必然选择.引入效益概念,从高校德育理论和实践着手,从教育价值、教育资源和教育效果等方面剖析当前高校德育的困境,论述优化高校德育效益的导向机制、投入机制和形成机制的必要性和可行性,为进一步加强和改进高校德育探寻实际的路径.     

Musth in elephants

Animal behaviour is intimately connected with chemical signaling, often through glandular secretions. This is very significant and obvious in Asian male elephants during their musth period when their temporal glands secrete a fluid with a characteristic odor. Musth gland activity greatly influences the elephant society as well as manelephant interaction.     

教师专业自主发展:内涵、意义及内在路径

教师的专业自主发展是指教师具有自我发展的意识和能力,包括主体意识、发展意识、创新意识和能力,能够主动地自觉地承担专业发展的主要责任,通过不断地学习、实践、反思、批判、创新,提升自己的教育教学能力,从而实现发展的多元性、差异性和创造性。它的意义在于:促进教师生活的主动性和创造性;促进学生自主学习和成长;提升教师的幸福感。实现教师的专业自主发展的内在路径是:提升教育专业精神;在自我反思和研究中成长;在合作、互动中成长;终身学习:教师的阅读。