Increased exhaled breath condensate 8-isoprostane after a swimming session in competitive swimmers

Objectives: This study aimed to evaluate the levels of 8-isoprostane (8-IsoP) in the airways of competitive swimmers at baseline and after a swimming session according to their airway responsiveness. Methods: Twenty-three swimmers and six lifeguards had a baseline spirometry and bronchoprovocative challenges. During a second visit, swimmers performed a usual swimming session while lifeguards stayed in the same pool environment for the same time period. Forced expiratory volume in one second (FEV₁) was measured before and 5 min after the end of the session. Exhaled breath condensate (EBC) was sampled before and 10 min after the session and EBC 8-IsoP levels were analysed by enzyme immunoassay. Change in EBC 8-IsoP from baseline to post-swimming session was calculated. Results: We observed no relationships between airway hyper-responsiveness and 8-IsoP values before or after swimming in swimmers. The levels of 8-IsoP were significantly higher after the training session (mean value 2.9, s?=?0.5 pg?mL^?1) than at baseline (mean value 1.9, s?=?0.4 pg?mL^?1) in swimmers only (p?=?.012). EBC 8-IsoP levels after the swimming session significantly correlated with the percent change in FEV₁ after swimming. Conclusions: EBC 8-IsoP levels were increased after training in swimmers but not in lifeguards, suggesting that exercise-induced hyperpnoea in a chlorinated pool environment increases airways oxidative stress.     

公开水域游泳运动的生理学研究进展

为公开水域游泳运动的选材、训练和比赛提供参考依据,提高我国公开水域游泳运动的发展水平,采用文献综述法,概述国内外公开水域游泳运动员ACE基因I/D多态性特征、低体温症、热应激以及运动性低钠血症的研究进展,相关研究结果发现： ACE-I等位基因是决定耐力素质的关键因素,5-10km公开水域游泳运动员与马拉松长跑运动员的ACE-I等位基因存在较大差异,但可能与室内游泳项目运动员相似;皮褶厚度影响机体隔绝外界低温的能力;下丘脑的体温调节中枢可作为个体出现低体温症的影响因素之一;游泳运动员的这种低汗率高但高Na+和Cl–的出汗适应性可能是导致游泳运动员在公开水域进行长时间游泳时出现低钠血症的主要原因之一。     

Stress in Israel: Voices in One Group Counseling Session of Counselor Trainees

This paper reveals the hidden voices of university students in a counselor training program who are caught in the Arab-Jewish conflict in Israel. These usually hidden voices emerged in a group counseling session, demonstrating the devastating effect that this type of stress has on Jewish and Arab Israelis alike. Implications for school counselors are discussed.     

Thermoelastic stresses in a uniformly heated functionally graded isotropic hollow cylinder

The axisymmetric themoelastic problem of a uniformly heated, functionally graded isotropic hollow cylinder is considered. An analytical form of solution is proposed. For the case when the Young's modulus and thermal expansion coefficient have a power-law dependence on the radial coordinate, explicit exact solution is obtained. For the degenerated case, i.e. when the cylinder is homogeneous and isotropic, no stresses will occur provided it is subjected to a uniform temperature. Numerical results are finally given and some important inclusions are obtained. Project (No.10002016) supported by the National Natural Science Foundation of China (NSFC).     

国外教师压力源研究的新进展

近十年来,教师压力水平普遍在提高。了解教师压力源是有效解决教师压力问题的必经之路。合理利用国外教师压力源的近期研究成果有助于我们缓解教师压力。     

基于神经网络结构分解与FLAC~(3D)的初始地应力场反演

介绍了采用FLAC30内嵌功能较强的FISH语言对初始地应力场生成方法的改进,建立了三维非线性地应力反演分析数值模型.模拟了断层及裂隙密集带,并采用此方法构造神经网络样本,采用神经网络结构分析的方式,对不同深度的侧向系数进行反演.通过正分析的计算结果与现场实测值对比,满足精度要求,表明所获得的岩体地应力场是基本合理的.     

Interaction between seed size and NaCl on germination and early seedling growth of some Turkish cultivars of chickpea （Cicer arietinum L.）

Chickpea is an important food legume crop of Turkey and is largely grown for human consumption on low moisture or salt-affected soils.The objective of the study was to find the effects of NaCl stress at electrical conductivities of 4.5,8.6,12.7 and 16.3 dS/m and seed sizes (7,8 and 9 mm) on germination and early seedling growth of three popular chickpea cultivars (AKN-97,Gokce and Uzunlu-99).Mean frequency of germination,germination time,germination index,root length,shoot length and seedling fresh weight showed seed size-dependent responses of cultivars to salt stress.In general,small seeds germinated and grew more rapidly compared to medium and large seeds of the same cultivars against all levels of salt stress,with the best results in cultivar Uzunlu-99.No effect of NaCl treatments was observed on frequency of germination; however,a drastic decrease in early seedling growth was recorded at increased NaCl concentrations.Regression analysis results showed a significantly positive rela-tionship (P<0.01) between seed size and mean germination time,whereas a significantly negative relationship was recorded between seed size and germination index,root length,shoot length.Moreover,linear regression values apparently confirmed that increased seed size in each cultivar affected decreased germination index,root and shoot lengths with enhanced mean germination time.Thus,it was concluded that the use of small seeds could considerably reduce the production costs of chickpea in salt-affected soils.     

Personal and Organizational Predictors of Compassion Fatigue Symptoms in Local Television Journalists

Compassion fatigue is a form of traumatic stress that results from repeated encounters with victims of trauma and traumatic situations. Most often studied in counselors, nurses, and first responders, this study applies the concept to journalists who often encounter the same victims and traumatic scenes. Seventy reporters from different television markets were measured for the personal and professional factors that contribute to compassion fatigue symptoms and its components of secondary traumatic stress and burnout. Results showed personal traumatic events and perceived peer support were the strongest predictors of compassion fatigue symptoms in television reporters. Implications for reporter self-care and newsroom protocols are discussed.     

基于"圆筒假设"的圆轴扭转应力分析

工程力学的理论推导是建立在许多假设基础上的,关于圆轴扭转的应力分析,本文提出了一种新的假设方法,基于该假设基础上的扭转剪应力分析推导,形象生动、过程简捷,有助于工程力学的教与学。     

某实际超长结构温度应力分析

超长钢筋混凝土结构温度应力分析一直是设计人员所关注的课题。文章结合工程实例对超长结构温度应力进行分析，提出了温差的取值方法，并采用PMSAP有限元软件对超长结构进行计算，分析其变形和内力特点，总结出了设计中减小温度应力的措施。