拳击运动员冬训阶段若干生化指标的监测研究

采用实验法与统计分析法，分析了我国拳击运动员在冬训上量阶段血清肌酸激酶、血尿素氮和血红蛋白的变化，以此来评定运动员的机能水平，并提出相应的建议。结果表明。血红蛋白与血尿素氮结合使用，能较准确地评定拳击运动员的身体机能状况，血清肌酸激酶能有效评定周期训练后肌肉所受的刺激程度。提出了适当的训练调整计划，以利于运动员下一阶段训练的顺利进行。     

基因工程在运动生物化学研究中的应用与展望

由于基因工程技术的引入，人们可以从分子机理上探讨运动生物化学的重要课题，如运动能力与基因表达的关系、运动性疲劳的分子机理、肌肉力量增加与基因控制的关系等。目前，利用基因工程技术促进运动生物化学的发展，主要体现在：1)对运动员进行科学选材；2)防治运动性疾病；3)防止人体运动时的代谢紊乱和加速恢复过程；4)改进人体机能状态，提高运动能力；5)加强反兴奋剂的力度。     

下坡跑运动对骨骼肌α7β1整合素及FAK表达的影响

通过观察下坡跑运动后α7β1整合素及FAK的表达和FAK活性的变化,探讨α7β1整合素在运动重复效应中作用机制。将32只小鼠随机分为安静对照组,运动后3 h组、24 h组、8 d组。小鼠进行一次性下坡跑运动,速度为17 m/min,坡度为-20°,时间为30 min。各组于各时刻点摘眼球取血及取双侧腓肠肌。比色法检测血清CK活性,Real-time PCR检测α7β1整合素及FAK的m RNA表达,Western blot检测α7β1整合素及p FAK397的蛋白表达。结果显示一次下坡跑运动后CK活性升高显著,且在24 h增幅增大。α7 integrin m RNA在一次运动后3 h显著增加,但在24 h变化不明显,但8 d时仍增加显著,其蛋白水平在运动后3 h显著增加,虽在24 h和8 d时升高程度逐渐降低但仍呈显著。β1 integrin m RNA在一次运动后3 h显著增加,24 h及8 d变化不明显,蛋白水平在一次运动后3 h呈显著升高,24 h升高程度增加,在8 d时回复。FAK m RNA在一次运动后3 h显著增加,24 h及8 d变化不明显,p FAK397水平在一次运动后呈现显著升高,24 h升高程度降低,8 d时基本回复。结果表明α7β1整合素-FAK信号通路介导了运动重复效应。     

高原耐力训练中抗高原反应能力关系研究

目的:研究通过高原耐力训练,生成体内血胰岛素,并建立起与抗高原反应能力关系模型,评估人体在高原等恶劣环境下训练的生理机能。方法:研究对象为本校篮球队在青藏高原驻训的23名篮球队员,采用SPSS 13.0统计软件,测得运动员体内产生的血胰岛素聚合物Pluronic-b-PCL(Entry 0)和Pluronic-b-P(CL-co-BCL)的显著差异性,从而分析与抗高原反应能力的关系。引入有助于提高抗高原反应的半乳糖分子,通过DLS测试粒子表面的zeta电位值,分析受测运动员的调节纤维激酶值。结果:在阳离子型嵌段共聚物P(PEGMEMA16-co-PEGMA7)-b-PDMAEMA53中N/P比分别为0.3,0.6,0.8,1.5,2.5,3.0,8.0,受测运动员的生成的P(PEGMEMA-co-PEGMA)-b-PDMAEMA为2.155 g,0.1 mmol,PMDETA(104μL,0.5 mmol),Cu Cl(0.0258 g,0.25 mmol),在运动后24 h,血胰岛素与抗高原反应能力相关系数有所增大,运动后48 h,血胰岛素生成与抗高原反应能力相关系数有所较小,同时BP与调节纤维激酶相关系数增大,抗高原反应能力显著提高(P0.05)。结论:通过高原耐力训练,逐步增加红细胞和血红蛋白的生成,促进血胰岛素生成,改善血液输送氧的能力,使新进入高原的人发挥他正常的生理效能,指导高原训练和高原反应病症的治疗和预防。     

Perform kicking with or without jumping: joint coordination and kinetic differences between Taekwondo back kicks and jumping back kicks

We investigated joint coordination differences between Taekwondo back kicks and jumping back kicks, and how jumping (in performing the latter) would alter engaging ground reaction forces (GRF) in executing kicking. Ten skilful athletes volunteered to perform both kinds of kicking within the shortest time for three successful trials. Three high-speed cameras and two force platforms were used for data collection, and the trial with the shortest execution time was selected for analysis. Movements were divided into the rotation and attack phases. With comparable execution time and maximum joint linear/angular speeds, back kicks and jumping back kicks differ mainly in larger GRF in the latter, and in greater target acceleration in the former probably because the support leg prevented athletes’ rebounding after impact. In addition, more prominent antiphase and in-phase coordination between the shoulder segment and knee joint, and elongated rotation phase were found in jumping back kicks. Larger GRF values in jumping back kicks were generated for jump take-off rather than for a more powerful attack. In back kicks although the support leg remained ground contact, greatly decreased GRF in the attack phase suggested that the support leg mainly served as a rotation axis.     

Validation of two accelerometers to determine mechanical loading of physical activities in children

The purpose of this study was to assess the validity of accelerometers using force plates (i.e., ground reaction force (GRF)) during the performance of different tasks of daily physical activity in children. Thirteen children (10.1 (range 5.4–15.7) years, 3 girls) wore two accelerometers (ActiGraph GT3X+ (ACT), GENEA (GEN)) at the hip that provide raw acceleration signals at 100 Hz. Participants completed different tasks (walking, jogging, running, landings from boxes of different height, rope skipping, dancing) on a force plate. GRF was collected for one step per trial (10 trials) for ambulatory movements and for all landings (10 trials), rope skips and dance procedures. Accelerometer outputs as peak loading (g) per activity were averaged. ANOVA, correlation analyses and Bland–Altman plots were computed to determine validity of accelerometers using GRF. There was a main effect of task with increasing acceleration values in tasks with increasing locomotion speed and landing height (P < 0.001). Data from ACT and GEN correlated with GRF (r = 0.90 and 0.89, respectively) and between each other (r = 0.98), but both accelerometers consistently overestimated GRF. The new generation of accelerometer models that allow raw signal detection are reasonably accurate to measure impact loading of bone in children, although they systematically overestimate GRF.     

烧结温度对La1.2Sr1.8Mn2O7结构和磁性的影响

采用溶胶-凝胶法在不同的烧结温度下制备了La1.2Sr1.8Mn2O7多晶样品.磁性测量表明,1 200℃热处理的样品存在3个磁转变温度,且在116 K～365 K温区范围内磁化强度显著高于1 400℃热处理的样品;同时,1 400℃热处理的样品,在整个温区只存在2个磁有序转变温度,并且呈现出类自旋玻璃态.结合这2个样品的结构分析发现,较高温度处理更有利于双层钙钛矿结构的形成.     

油酸三乙醇胺皂化物的合成

采用单因素控制变量法,以扣除酸值后的皂化值为评价指标,研究了反应配比、反应温度、反应时间对合成油酸三乙醇胺皂化物的影响。结果表明,油酸和三乙醇胺配比为1.2∶1(mol/mol)、温度为130℃、反应时间为3h时,反应达到平衡时体系中油酸三乙醇胺皂化物的含量最多。利用合成的油酸三乙醇胺皂化物调配成的水基润滑油符合相关要求。     

延迟焦化过程抑制镍钒脱氢反应的初步研究

延迟焦化在原油深度加工中地位日益突出,其工艺技术进展的主要目标是最大限度地提高液体油收率。文章针对镍钒存在形态、脱氢反应的影响、抑制脱氢反应展开讨论,并提出钝化镍钒作用的对策,从理论研究找出切实可行的方法来指导生产实践。     

基于案例分析的国外在华“微传播”政府应对研究--以新浪微博为例

以国外政府机构和政要入驻新浪微博的典型案例为研究对象,利用内容分析法和案例分析法,探析国外在华“微传播”现象并总结相应政府应对策略。研究发现,国外政府机构和政要善用自媒体社交工具展开全方位的信息传播与价值输出,对此,我国一方面要关注、警惕,另一方面也要学习、借鉴。