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21.
补充胆红素对不同强度运动大鼠肝细胞凋亡的影响   总被引:2,自引:0,他引:2  
目的:观察补充胆红素对不同强度运动造成的肝细胞凋亡的影响,为运动营养补剂的研发,减少运动性损伤提供一定的实验依据。方法:以53只健康雄性SD大鼠为研究对象,随机分成五个组,即安静对照组、中等强度运动训练组、中等强度运动训练补胆红素组、大强度运动训练组、大强度运动训练补胆红素组,力竭运动组、力竭运动补胆红素组、通过流式细胞仪检测技术检测强抗氧化剂对肝细胞凋亡的影响。同时观察与分析肝组织SOD的活性与MDA的含量。结果表明:力竭运动和大强度运动训练能诱导大鼠肝细胞凋亡增加;补充胆红素使其凋亡率下降,其原因与补充胆红素能提高机体抗氧化应激有关。  相似文献   
22.
Abstract

Low energy availability [(energy intake – exercise expenditure)/kg lean body mass], a component of the Female Athlete Triad, has been associated with menstrual disturbances and low bone mass. No studies have examined the energy availability of athletes across a season. The purpose of this study was to assess the prevalence of, and what contributes to, low energy availability in Division I female soccer players across a season. Nineteen participants aged 18–21 years (mean [Vdot]O2max: 57.0 ± 1.0 mL · kg?1 · min?1) were studied during the pre, mid, and post season. Mean energy availability was overall lowest at mid season, and lower at mid than post season (35.2 ± 3.7 vs. 44.5 ± 3.7 kcal · kg?1 lean body mass, P = 0.009). Low energy availability (<30 kcal · kg?1 lean body mass) was observed in 5/19 (26.3%), 5/15 (33.3%), and 2/17 (11.8%) of participants during the pre, mid, and post season. Dietary energy intake was lower mid (P = 0.008) and post season (P = 0.022) than it was pre season (pre: 2794 ± 233 kcal · day?1; mid: 2208 ± 156 kcal · day?1; post: 2161 ± 143 kcal · day?1). Exercise energy expenditure decreased significantly (P ≤ 0.001) over time (pre: 819 ± 57 kcal · day?1; mid: 642 ± 26 kcal · day?1; post: 159 ± 28 kcal · day?1). Low energy availability was due to lower dietary energy intake at lunch during pre season (P = 0.014) and during lunch and dinner during mid season (P ≤ 0.030). Energy availability was inversely related to body dissatisfaction (r = ?0.62, P = 0.017) and drive for thinness (r = ?0.55, P = 0.041) during mid season. Although most Division I female soccer players are not at risk for low energy availability, a concerning proportion exhibited low energy availability at pre or mid season. Further studies are needed to explore strategies to prevent and monitor low energy availability in these athletes.  相似文献   
23.
    
Nutrition intervention is the key to prevent and control diabetes mellitus. Diabetic patients’ nutrition intervention requires reasonably control of the intakes of the three major nutrients. A diabetes diet nutrition optimization method based on particle swarm optimization (PSO) algorithm is proposed for individual nutritional intervention of diabetes. Firstly, a nutritional optimization mathematical model is established, which meets the demand of diabetic patients’ three major nutrients intake, and then an improved particle swarm optimization algorithm is applied to solve the model. To enhance the convergence speed and search ability of the standard particle swarm optimization, the adaptive inertia weight factor and the natural selection mechanism are introduced in PSO. The performance of the proposed method is verified through an experiment, and the attainment rates of three major nutrients in the designed recipes are close to 100? according to the experimental results, which indicates that it can greatly improve the precision of diabetes nutrition recipes  相似文献   
24.
运用“打击-轮换”声控训练法,对上海市杨浦区少体校网球运动员进行为期1年的训练后发现,运动员的心率、最大摄氧量、公斤体质量最大摄氧量、呼吸商、代谢当量、能量代谢方式均发生明显变化,测试冲关数、测试底线击球数、底线击球成功率都有了较大的提高.研究表明“打击-轮换”声控训练法,能有效提高专业网球运动员的心肺功能和底线有氧击球运动能力,并且运动员的有氧运动能力与运动水平成正比,有氧运动能力强时底线跑动击球能力就强,底线击球成功率也高.  相似文献   
25.
    
Abstract

The assessment of nutrition and activity in athletes requires accurate and precise methods. The aim of this study was to validate a protocol for parallel assessment of diet and exercise against doubly labelled water, 24-h urea excretion, and respiratory gas exchange. The participants were 14 male triathletes under normal training conditions. Energy intake and doubly labelled water were weakly associated with each other (r = 0.69, standard error of estimate [SEE] = 304 kcal · day?1). Protein intake was strongly correlated with 24-h urea (r = 0.89) but showed considerable individual variation (SEE = 0.34 g · kg?1 · day?1). Total energy expenditure based on recorded activities was highly correlated with doubly labelled water (r = 0.95, SEE = 195 kcal · day?1) but was proportionally biased. During running and cycling, estimated exercise energy expenditure was highly correlated with gas exchange (running: r = 0.89, SEE = 1.6 kcal · min?1; cycling: r = 0.95, SEE = 1.4 kcal · min?1). High exercise energy expenditure was slightly underestimated during running. For nutrition data, variations appear too large for precise measurements in individual athletes, which is a common problem of dietary assessment methods. Despite the high correlations of total energy expenditure and exercise energy expenditure with reference methods, a correction for systematic errors is necessary for the valid estimation of energetic requirements in individual athletes.  相似文献   
26.
谢志清  张亮  李锐 《大众科技》2012,(7):183-184,169
介绍了汽车进气系统的功用及主要性能指标;结合进气系统开发实例探讨了进气系统容积的设定、管路形状及截面积的选择、内插管及谐振管等元件的应用等设计因素对进气系统性能所产生的影响。  相似文献   
27.
硒作为一种新型的抗氧化剂,在清除机体的氧自由基、抗氧化、延缓疲劳的出现和降低运动机体细胞凋亡率方面起一定的作用。探讨补硒的情况下实验大鼠肌肉细胞在运动过程中和运动后细胞凋亡的发生状况,找出安全有效的补硒量,将大鼠适应性喂养1周后,随机分为安静对照组、训练组和训练补硒组进行恒定负荷训练。结果发现,无论补硒还是不补硒运动组均有细胞核染色质浓缩及靠近核膜、核膜增厚等典型细胞凋亡的形态结构改变,运动训练可能导致骨骼肌细胞出现凋亡。补硒对阻止和延迟运动造成的细胞凋亡的发生有一定的作用,但由于其自身的副作用,可能会诱导一定数量的细胞凋亡。安全有效的补硒剂量应该往量小的方向寻找。  相似文献   
28.
    
Childhood maltreatment has been associated with a wide range of chronic medical conditions including obesity, other metabolic events and eating disorders. However, little is known about the association between childhood maltreatment and high dietary fat intake. This study addresses the extent to which co-occurring and specific forms of substantiated childhood maltreatment are associated with self-reported high dietary fat intake in adulthood and whether there is a gender–childhood maltreatment interaction in predicting this association. The study also examines the association between age at substantiation of maltreatment, number of childhood maltreatment substantiations and high dietary fat intake-related behaviors. The data were from a prospective Australian pre-birth mother-child dyads study, the Mater-University of Queensland Study of Pregnancy. The study followed 7223 mother-child dyads following the birth of a live, singleton baby at the Mater hospital. Recruitment was early in pregnancy, and then follow-ups at 3–5 days postpartum and again when the child was 6 months, 5, 14 and 21 years of age. The data were linked to agency-substantiated cases of childhood maltreatment 0–14 years. This study extended the data linkage to 3766 (47.4% female) participants who had complete data on dietary fat intake behaviors at the 21-year follow-up. Consecutive logistic regressions were used to estimate odds ratios with respective 95% confidence intervals for high dietary fat intake for multiple and specific forms of childhood maltreatment, as well as age at and number of childhood maltreatment substantiations. Finally, a gender–childhood maltreatment interaction term was used to predict the outcome. In both unadjusted and adjusted analyses, substantiated childhood maltreatment including physical abuse were associated with high dietary fat intake-related behaviors. Similarly, substantiation of childhood maltreatment between the ages of 5 and 14 years was significantly associated with high dietary fat intake-related behaviors as were two or more substantiations of maltreatment. Inclusion of gender–childhood maltreatment interaction only had a minor impact on the size and direction of the association. Chronic and severe forms of childhood maltreatment including physical abuse are associated with a higher rate of dietary fat intake in young adulthood. Further research to replicate this association might focus on possible neuro-hormonal mechanisms that might explain this behavior.  相似文献   
29.
从运动、营养与免疫相互关系角度出发,对近几年各种增强运动免疫的运动营养补剂的研究情况进行归纳和总结,在此基础上,预测今后运动免疫营养补剂的发展前景.  相似文献   
30.
Using a randomised cross-over design, free-living lunch intake and subjective appetite were examined in 10 children (9.8 ± 0.6 years) following high-intensity interval training (HIIT) versus a control sedentary (SED) period, within a school setting. The 22-min HIIT took place during a regular PE lesson and consisted of two rounds of 4 × 30 s sprints. Foods were offered at a regular school lunch immediately following HIIT and SED and were matched between conditions. All food was covertly weighed before and after the meal. Hunger, fullness and prospective consumption were reported immediately before and after HIIT/SED, using visual analogue scales. Heart rate was higher during HIIT than SED (159.3 ± 23.1 vs. 76.9 ± 2.2 bpm, < 0.05). Lunch energy intake was not different (P = 0.52) following HIIT, compared to SED (2.06 ± 0.35 vs. 2.09 ± 0.29 MJ, respectively). There were no significant differences in macronutrient intake or subjective appetite (P > 0.05). Results suggest that HIIT can be implemented in a PE lesson immediately before lunch, without causing a compensatory increase in food consumption.  相似文献   
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