石油污染物对日本三角涡虫的毒理作用、摄食及再生的影响

研究石油污染物对日本三角涡虫的急性毒性、摄食及再生的影响。结果表明,石油污染物对日本三角涡虫的24hLC50、48hLC50分别为83.47g／L、56.83g／L;≤6.67g／L的污染物对日本三角涡虫摄食的影响随污染浓度的增大与染毒时间的延长而增强;≥10.00g／L的污染物对涡虫再生的影响显著（P〈0.05）,且随处理时间的延长而影响逐渐减小。表明日本三角涡虫可作为检测石油污染物对水体污染程度的指示生物。     

The influence of intermittent high-intensity shuttle running and fluid ingestion on the performance of a soccer skill

The aim of this study was to examine the effect of intermittent high-intensity shuttle running and fluid ingestion on the performance of a soccer skill. Nine semi-professional soccer players volunteered to participate in the study. Their mean (± _sx ) age, body mass and maximal oxygen uptake were 20.2 ± 0.4 years, 73.2 ± 1.8 kg and 59.1 ± 1.3 ml·kg^-1 ·min^-1 respectively. The players were allocated to two randomly assigned trials: ingesting or abstaining from fluid intake during a 90 min intermittent exercise protocol (Loughborough Intermittent Shuttle Test:LIST).This test was designed to simulate the minimum physical demands faced by soccer players during a game. Before and immediately after performance of the test,the players completed a soccer skill test and a mental concentration test. Performance of the soccer skill test after the 'no-fluid' trial deteriorated by 5% (P ? 0.05),but was maintained during the fluid trial. Mean heart rate, perceived exertion, serum aldosterone, osmolality, sodium and cortisol responses during the test were higher (P ? 0.05) in the 'no-fluid' trial than in the fluid trial. The results of this study suggest that soccer players should consume fluid throughout a game to help prevent a deterioration in skill performance.