高原或低氧环境下脱水与补液的研究进展     

郭红 《中国体育科技》2006,42(5):74-77

高原或低氧环境下体液平衡的改变主要表现为脱水和尿钠排泄。这与低氧刺激下交感神经兴奋性提高,外周化学感受器激发肾脏反应及体液调节激素的改变有关。低氧刺激使机体对营养素和液体的要求提高,但摄入降低,因此,机体应当补充足够的营养素和富含碳水化合物及电解质的液体。综述了高原或低氧环境下机体的体液平衡改变及其机制,提出了低氧下补液的主要原则,并指出了亟待研究的主要问题。  相似文献   

The Language Environment of Toddlers in Center-based Care versus Home Settings     

Ann D. Murray  Bronwyn S. Fees  Linda K. Crowe  Molly E. Murphy  Amanda L. Henriksen 《Early Childhood Education Journal》2006,34(3):233-239

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Study on the neurotoxic effects of low-level lead exposure in rats   总被引：10，自引：0，他引：10  

Zhu ZW  Yang RL  Dong GJ  Zhao ZY 《Journal of Zhejiang University. Science. B》2005,6(7):686-692

Objective: To investigate effects of developmental lead exposure on nitric oxide synthase (NOS) activity in different brain regions and on N-methyl-D-aspartate (NMDA) receptor mRNA expression in the hippocampus of rats. On the basis of these observations, we explored possible mechanisms by which lead exposure leads to impaired learning and memorizing abilities in children. Methods: A series of rat animal models exposed to low levels of lead during the developing period was established (drinking water containing 0.025%, 0.05% and 0.075% lead acetate). NOS activities in the hippocampus, the cerebral cortex, the cerebellum and the brain stem were determined with fluorescence measurement and levels of mRNA expression of the NMDA receptor 2A (NR2A) subunit and NMDA receptor 2B (NR2B) subunit in the rat hippocampus were measured with Retro-translation (RT-PCR). Results: There were no differences in the body weight of rat pups between any of the groups at any given time (P>0.05). The blood lead level of Pb-exposed rat pups showed a systematic pattern of change: at 14 d of age, it was lower than that at 7 d of age, then rising to the peak level at 21 d and finally falling to lower levels at 28 d. The hippocampal NOS activities of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.01). NOS activities in the cerebellum of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.001) and the NOS activity of the 0.025% group was significantly lower than that of the 0.05% and 0.075% groups on the 28th day (P<0.05). NOS activity in the cerebral cortex of the 0.075% group was significantly lower than that of the control, 0.025% and 0.05% groups on the four day spans (P<0.001). There was no significant difference of NOS activity in the brain stem between any lead-exposed group and the control group on the four day spans. In the 0.05% and the 0.075% groups, the level of NR2A mRNA expression was higher than that in the control group at 7 d and 14 d of age (P<0.05). In the 0.025% group, the level of NR2A was found to be higher than that in the control group at 7 d of age only (P<0.05). No significant differences were found for the levels of NR2B mRNA expression between any of the groups at any given time. Conclusions: NOS activity in the hippocampus, the cerebral cortex and the cerebellum are inhibited by lead exposure. The degree of the inhibitory effect depends on the time span of exposure and the lead concentration. Developmental low-level lead exposure was found to raise the level of NR2A mRNA expression in the hippocampus of rats. Developmental low-level lead exposure does not affect the level of NR2B mRNA expression in the hippocampus.  相似文献   

低氧暴露对运动性血红蛋白低下游泳运动员红细胞参数和EPO变化的影响     

陈福刁  陈浩庆  王翔 《韩山师范学院学报》2007,28(6):67-72

运动性低血红蛋白引起红细胞运输氧和二氧化碳的能力及物质代谢能力下降,影响运动能力。实验研究了低氧暴露条件下运动性低血红蛋白游泳运动员的红细胞参数和促红细胞生成素(EPO)的变化情况,探讨低氧防治运动性血红蛋白低下的效果。  相似文献   

丈夫：在城市底层敞开的身份——解读沈从文的《丈夫》     

田级会  谭必友 《黄冈师范学院学报》2008,28(4):92-95

沈从文《丈夫》是一篇凄美精致的短篇小说。作品讲述了一个乡下青年丈夫到县城看望以做妓女为谋生手段的妻子的故事。这个青年丈夫在目睹妻子的接客生活后,逐渐触动了对自己身份的再认识,终于彻底放弃了以前的幻想,夫妻俩重新回到自己的乡下家里。沈从文描写了一个有关丈夫身份澄明的非常特殊的历史故事。  相似文献   

Social inequalities in early childhood competences,and the relative role of social and emotional versus cognitive skills in predicting adult outcomes     

Ingrid Schoon  Bilal Nasim  Rose Cook 《British Educational Research Journal》2021,47(5):1259-1280

This study draws on the nationally representative British Birth Cohort Study (BCS70) to examine (1) the association between social background and early socio-emotional and cognitive competences at age 5 and (2) the relative and independent contributions of early socio-emotional and cognitive competences to educational and socio-economic attainment in adulthood. A multi-dimensional (multiple exposure, multiple outcome) approach is adopted in conceptualising social background, childhood competences and adult outcomes by age 42. Indicators of social background include parental education, social class, employment status, family income, as well as home ownership, enabling us to test which aspects of socio-economic risk uniquely influence the development of early competences. Indicators of childhood competences include directly assessed cognitive competences (i.e. verbal and visual motor skills), while measures of socio-emotional competences include hyperactivity, good conduct, emotional health and social skills, reported by the child’s mother at age 5. Adult outcomes include highest qualifications, social class and household income by age 42. The findings suggest that multiple indicators of social background are associated with both socio-emotional and cognitive competences, although the associations with socio-emotional competences are less strong than those with cognitive competences. We find significant long-term predictive effects of early cognitive skills on adult outcomes, but also independent effects of socio-emotional competences, in particular self-regulation, over and above the role of family background. The study supports calls for early interventions aiming to reduce family socio-economic risk exposure and supporting the development of cognitive skills and self-regulation (i.e. reducing hyperactivity and conduct problems).  相似文献   

速大肥对断奶仔猪小肠粘膜形态结构的影响     

闻爱友  曹发鑫  胡军  郑宏俊 《安徽科技学院学报》2002,16(3):36-38

试验选用28日龄断奶的杜长定三元杂交仔猪28头,随机分成2组,用于研究日粮中添加20g/t速大肥对断乳仔猪小肠粘膜结构及形态的影响,结果表明:与对照组相比,添加速大肥可有效地防止断奶后1周内小肠绒毛萎缩、隐窝深度加深,降低断奶后2周内空肠固有膜厚度,这表明了在仔猪日粮中添加速大肥可以改善仔猪肠道的通透性的对营养物质的吸收功能.  相似文献   

《官场现形记》“现形”的心理学分析     

骆田茵 《嘉应学院学报》2011,29(6):58-61

李宝嘉(1867—1906)是清末谴责小说的代表作家,他对中国近代现实主义小说的发展作出了重要贡献。在其代表作《官场现形记》中,作者主要从三个层面揭露了晚清官场权力追逐的丑态。本文试图运用心理学的相关理论去分析小说中描写的官场丑态,探讨晚清官员腐败堕落的社会心理根源。  相似文献   

关于高校资助工作中贫困学生“高曝光率”问题的思考     

袁雨茜 《科教文汇》2013,(30):165-166

高校贫困生作为高校中的特殊群体,不断得到国家和社会的关注。高校助困模式的不断发展显示出国家和社会对高校贫困生问题的重视。但是,我国目前以高曝光率为特征的助困方式,一方面促进了经济助困力度的加强．缓解了高校贫困生的经济压力;另一方面带来新的问题：有的贫困生增加了精神或心理压力、有的贫困生养成了依赖习惯等等。如何在帮助贫困学生完成学业健康成长的同时,保护好贫困学生的个人生活和隐私受到尊重,值得深入思考和研究。  相似文献   

光谱感光板特性曲线的测量     

粟琼  金泽渊  彭跃华 《凯里学院学报》2002,20(6):13-14

在光谱分析中 ,广泛应用的仍为照相法记录光谱 .对所用干板在使用波长的反差、正常曝光范围、感光灵敏度等参量必须要进行测定 ,我们采用时间标法对感光板的特性曲线进行测定  相似文献