Our previous study revealed that early application of electrical field stimulation（EFS） with the anode at the lesion and the cathode distal to the lesion reduced injury potential, inhibited secondary injury and was ...Our previous study revealed that early application of electrical field stimulation（EFS） with the anode at the lesion and the cathode distal to the lesion reduced injury potential, inhibited secondary injury and was neuroprotective in the dorsal corticospinal tract after spinal cord injury（SCI）. The objective of this study was to further evaluate the effect of EFS on protection of anterior horn motoneurons and their target musculature after SCI and its mechanism. Rats were randomized into three equal groups. The EFS group received EFS for 30 minutes immediately after injury at T_（10）. SCI group rats were only subjected to SCI and sham group rats were only subjected to laminectomy. Luxol fast blue staining demonstrated that spinal cord tissue in the injury center was better protected; cross-sectional area and perimeter of injured tissue were significantly smaller in the EFS group than in the SCI group. Immunofluorescence and transmission electron microscopy showed that the number of spinal cord anterior horn motoneurons was greater and the number of abnormal neurons reduced in the EFS group compared with the SCI group. Wet weight and cross-sectional area of vastus lateralis muscles were smaller in the SCI group to in the sham group. However, EFS improved muscle atrophy and behavioral examination showed that EFS significantly increased the angle in the inclined plane test and Tarlov＇s motor grading score. The above results confirm that early EFS can effectively impede spinal cord anterior horn motoneuron loss, promote motor function recovery and reduce muscle atrophy in rats after SCI.展开更多
复合绝缘子的伞套材料必须具备极好的耐漏电起痕与电蚀损性,以确保其长期运行的可靠性。斜面法试验是常用的耐漏电起痕与电蚀损性试验方法,泄漏电流分析是研究斜面法试验严酷性的重要手段。设计了一种新的适用于交流斜面法试验的电弧辨...复合绝缘子的伞套材料必须具备极好的耐漏电起痕与电蚀损性,以确保其长期运行的可靠性。斜面法试验是常用的耐漏电起痕与电蚀损性试验方法,泄漏电流分析是研究斜面法试验严酷性的重要手段。设计了一种新的适用于交流斜面法试验的电弧辨识算法,对4.5 k V标准交流斜面法试验中高温硫化固体硅橡胶（HTV）样品的泄漏电流进行分析。结果表明,HTV样品的电弧特征参数分布具有长尾特性;长尾特性使得电弧特征参数不能严格地服从正态或对数正态分布。根据燃弧时间的移动平均曲线,可以将HTV样品电蚀损过程定量划分为慢速电蚀损阶段和快速电蚀损阶段。在慢速电蚀损阶段,电弧特征参数基本保持稳定;进入快速电蚀损阶段时,电弧特征参数会发生阶跃式变化。展开更多
现行标准中仅给出交流斜面法的试验条件,而未给出直流斜面法的试验方法,而试验电压是斜面法试验中的基本参数。为此,文中针对直流条件下试验电压对硅橡胶材料蚀损程度的影响展开研究。在污液流速为0.2 m L/min的条件下,使用高速摄像机...现行标准中仅给出交流斜面法的试验条件,而未给出直流斜面法的试验方法,而试验电压是斜面法试验中的基本参数。为此,文中针对直流条件下试验电压对硅橡胶材料蚀损程度的影响展开研究。在污液流速为0.2 m L/min的条件下,使用高速摄像机、红外热像仪观察不同试验电压下硅橡胶材料表面电弧的放电现象和温度场分布,并记录不同试验电压下的泄漏电流、质量损失和最大蚀损深度。试验结果表明,随着试验电压增大,电弧弧长明显增大,累计放电时间减小,试样的质量损失和最大蚀损深度均减小。研究说明试验电压的增大虽然增加了试样烧蚀面积,但是由于放电时间减少,试验的严酷程度减轻。展开更多
基金supported by the National Natural Science Foundation of China,No.31400717,51577183the Natural Science Foundation of Beijing of China,No.7164317the Youth Innovation Promotion Association CAS,No.2018172
文摘Our previous study revealed that early application of electrical field stimulation（EFS） with the anode at the lesion and the cathode distal to the lesion reduced injury potential, inhibited secondary injury and was neuroprotective in the dorsal corticospinal tract after spinal cord injury（SCI）. The objective of this study was to further evaluate the effect of EFS on protection of anterior horn motoneurons and their target musculature after SCI and its mechanism. Rats were randomized into three equal groups. The EFS group received EFS for 30 minutes immediately after injury at T_（10）. SCI group rats were only subjected to SCI and sham group rats were only subjected to laminectomy. Luxol fast blue staining demonstrated that spinal cord tissue in the injury center was better protected; cross-sectional area and perimeter of injured tissue were significantly smaller in the EFS group than in the SCI group. Immunofluorescence and transmission electron microscopy showed that the number of spinal cord anterior horn motoneurons was greater and the number of abnormal neurons reduced in the EFS group compared with the SCI group. Wet weight and cross-sectional area of vastus lateralis muscles were smaller in the SCI group to in the sham group. However, EFS improved muscle atrophy and behavioral examination showed that EFS significantly increased the angle in the inclined plane test and Tarlov＇s motor grading score. The above results confirm that early EFS can effectively impede spinal cord anterior horn motoneuron loss, promote motor function recovery and reduce muscle atrophy in rats after SCI.
文摘复合绝缘子的伞套材料必须具备极好的耐漏电起痕与电蚀损性,以确保其长期运行的可靠性。斜面法试验是常用的耐漏电起痕与电蚀损性试验方法,泄漏电流分析是研究斜面法试验严酷性的重要手段。设计了一种新的适用于交流斜面法试验的电弧辨识算法,对4.5 k V标准交流斜面法试验中高温硫化固体硅橡胶（HTV）样品的泄漏电流进行分析。结果表明,HTV样品的电弧特征参数分布具有长尾特性;长尾特性使得电弧特征参数不能严格地服从正态或对数正态分布。根据燃弧时间的移动平均曲线,可以将HTV样品电蚀损过程定量划分为慢速电蚀损阶段和快速电蚀损阶段。在慢速电蚀损阶段,电弧特征参数基本保持稳定;进入快速电蚀损阶段时,电弧特征参数会发生阶跃式变化。
文摘现行标准中仅给出交流斜面法的试验条件,而未给出直流斜面法的试验方法,而试验电压是斜面法试验中的基本参数。为此,文中针对直流条件下试验电压对硅橡胶材料蚀损程度的影响展开研究。在污液流速为0.2 m L/min的条件下,使用高速摄像机、红外热像仪观察不同试验电压下硅橡胶材料表面电弧的放电现象和温度场分布,并记录不同试验电压下的泄漏电流、质量损失和最大蚀损深度。试验结果表明,随着试验电压增大,电弧弧长明显增大,累计放电时间减小,试样的质量损失和最大蚀损深度均减小。研究说明试验电压的增大虽然增加了试样烧蚀面积,但是由于放电时间减少,试验的严酷程度减轻。
