目的:观察有氧运动对自发性高血压大鼠(SHR)脑动脉平滑肌细胞自发瞬时外向电流(STOCs)的影响。方法:选用雄性SHR 24只,随机分为高血压安静组(SHR-SED组)和高血压运动组(SHR-EX组),后者进行8周有氧跑台运动。另选用同龄雄性WKY大鼠12只...目的:观察有氧运动对自发性高血压大鼠(SHR)脑动脉平滑肌细胞自发瞬时外向电流(STOCs)的影响。方法:选用雄性SHR 24只,随机分为高血压安静组(SHR-SED组)和高血压运动组(SHR-EX组),后者进行8周有氧跑台运动。另选用同龄雄性WKY大鼠12只作为正常血压对照组。8周后,取脑动脉,用酶消化法急性分离脑动脉平滑肌细胞。采用穿孔膜片钳实验记录各组大鼠脑动脉STOCs的变化。结果:(1)SHR-SED组基础收缩压显著高于WKY组,经过有氧运动训练后收缩压显著下降,但仍较WKY组高(P<0.01)。(2)STOCs具有明显的电压依赖性,可被1 m M caffeine激活而被100 n M IBTX阻断;(3)在相同钳制电位下,自发性高血压可以显著增加脑动脉平滑肌细胞的STOCs的幅值,而频率无显著性改变。(4)有氧运动显著降低由高血压导致的STOCs幅值增高,而对频率无显著性影响。结论:自发性高血压大鼠脑动脉平滑肌细胞STOCs的幅值显著增大,与高血压背景下大电导钙激活钾通道(BKCa)功能的代偿性增强有关;长期有氧运动可以显著抑制此增强效应,阻止高血压背景下的BKCa通道的病理性改变。展开更多
Knowledge of the equilibrium bed-concentration is vital to mathematic a l modeling of the river-bed deformation associated with suspended load but prev i ous investigations only dealt with the reference concentration ...Knowledge of the equilibrium bed-concentration is vital to mathematic a l modeling of the river-bed deformation associated with suspended load but prev i ous investigations only dealt with the reference concentration of uniform sedime nt because of difficulties in observation of the bed-concentration. This work i s a first attempt to develop a theoretical formula for the equilibrium bed-conce n tration of any fraction of nonuniform sediment defined at the bed-surface. The f ormula is based on a stochastic-mechanistic model for the exchange of nonunifor m sediment near the bed, and described as a function of incipient motion probabil ity, non-ceasing probability, pick-up probability, and the ratio of the averag e single-step continuous motion time to static time. Comparison of bed-concentra ti on calculated from the proposed formula with the measured data showed satisfacto ry agreement, indicating the present formula can be used for solving the differe ntial equation governing the motion of suspended load.展开更多
Tebian Electric Apparatus Stock Co.,Ltd.(TBEA,SH:600089) announced on January 17th it intends to build a polycrystalline silicone project in its subsidiary Xinjiang SunOasis Co.,Ltd.in Urumqi to ensure supply of feed-...Tebian Electric Apparatus Stock Co.,Ltd.(TBEA,SH:600089) announced on January 17th it intends to build a polycrystalline silicone project in its subsidiary Xinjiang SunOasis Co.,Ltd.in Urumqi to ensure supply of feed-stock polycrystalline silicone.The planned facility is expected to produce 15.thousand tons of polycrys-展开更多
文摘目的:观察有氧运动对自发性高血压大鼠(SHR)脑动脉平滑肌细胞自发瞬时外向电流(STOCs)的影响。方法:选用雄性SHR 24只,随机分为高血压安静组(SHR-SED组)和高血压运动组(SHR-EX组),后者进行8周有氧跑台运动。另选用同龄雄性WKY大鼠12只作为正常血压对照组。8周后,取脑动脉,用酶消化法急性分离脑动脉平滑肌细胞。采用穿孔膜片钳实验记录各组大鼠脑动脉STOCs的变化。结果:(1)SHR-SED组基础收缩压显著高于WKY组,经过有氧运动训练后收缩压显著下降,但仍较WKY组高(P<0.01)。(2)STOCs具有明显的电压依赖性,可被1 m M caffeine激活而被100 n M IBTX阻断;(3)在相同钳制电位下,自发性高血压可以显著增加脑动脉平滑肌细胞的STOCs的幅值,而频率无显著性改变。(4)有氧运动显著降低由高血压导致的STOCs幅值增高,而对频率无显著性影响。结论:自发性高血压大鼠脑动脉平滑肌细胞STOCs的幅值显著增大,与高血压背景下大电导钙激活钾通道(BKCa)功能的代偿性增强有关;长期有氧运动可以显著抑制此增强效应,阻止高血压背景下的BKCa通道的病理性改变。
文摘Knowledge of the equilibrium bed-concentration is vital to mathematic a l modeling of the river-bed deformation associated with suspended load but prev i ous investigations only dealt with the reference concentration of uniform sedime nt because of difficulties in observation of the bed-concentration. This work i s a first attempt to develop a theoretical formula for the equilibrium bed-conce n tration of any fraction of nonuniform sediment defined at the bed-surface. The f ormula is based on a stochastic-mechanistic model for the exchange of nonunifor m sediment near the bed, and described as a function of incipient motion probabil ity, non-ceasing probability, pick-up probability, and the ratio of the averag e single-step continuous motion time to static time. Comparison of bed-concentra ti on calculated from the proposed formula with the measured data showed satisfacto ry agreement, indicating the present formula can be used for solving the differe ntial equation governing the motion of suspended load.
文摘Tebian Electric Apparatus Stock Co.,Ltd.(TBEA,SH:600089) announced on January 17th it intends to build a polycrystalline silicone project in its subsidiary Xinjiang SunOasis Co.,Ltd.in Urumqi to ensure supply of feed-stock polycrystalline silicone.The planned facility is expected to produce 15.thousand tons of polycrys-
