目的:探索帕金森病伴冻结步态患者胫骨前肌和腓肠肌在直线行走过程中表面肌电(surface electromyogram,sEMG)的改变及其与临床特征之间的相关性。方法:选取符合入选标准的12例帕金森病伴冻结步态患者、13例帕金森病不伴冻结步态患者和11例健康对照受试者接受临床特征、步态时空参数和直线行走sEMG评估。分析步态周期各时段中重症侧胫骨前肌和腓肠肌内侧头的sEMG信号特征改变,指标选用标准化均方根振幅(root mean square,RMS)值和共激活比值。同时,探索sEMG改变与临床特征之间的相关性。结果:与健康受试者和非冻结步态患者相比,冻结步态患者的步速减慢、步幅缩短、摆动相减少、步态变异性增加(P<0.05)。在步态周期的单支撑相阶段,冻结步态患者胫骨前肌标准化RMS较健康对照降低(P<0.05);在摆动前期,冻结步态患者胫骨前肌标准化RMS较非冻结步态患者显著下降(P<0.01),但非冻结步态患者胫骨前肌标准化RMS较健康对照增加(P<0.01)。对于腓肠肌标准化RMS,冻结步态患者在摆动前期较非冻结步态患者和健康对照均显著降低(P<0.05)。此外,冻结步态患者的胫骨前肌-腓肠肌共激活比值在摆动相较非冻结步态患者降低(P<0.05)。冻结步态患者摆动前期腓肠肌标准化RMS与冻结步态严重程度(r=-0.758,P=0.007)、摆动相共激活比值和步幅变异性(r=0.716,P=0.013)显著相关。结论:直线行走步态周期中摆动前期胫骨前肌和腓肠肌的sEMG活动下降、摆动相胫骨前肌-腓肠肌共激活比值降低是帕金森病冻结步态患者的重要特征。
To reduce heat loss and save cost, a combination decision model of reverb aluminum holding furnace linings in aluminum casting industry was established based on economic thickness method, and was resolved using simula...
详细信息
To reduce heat loss and save cost, a combination decision model of reverb aluminum holding furnace linings in aluminum casting industry was established based on economic thickness method, and was resolved using simulated annealing. Meanwhile, a three-dimensional mathematical model of aluminum holding furnace linings was developed and integrated with user-defined heat load distribution regime model. The optimal combination was as follows: side wall with 80 mm alumino-silicate fiber felts, 232 mm diatomite brick and 116 mm chamotte brick; top wall with 50 mm clay castables, 110 mm alumino-silicate fiber felts and 200 mm refractory concrete;and bottom wall with 232 mm high-alumina brick, 60 mm clay castables and 68 mm diatomite brick. Lining temperature from high to low was successively bottom wall, side wall, and top wall. Lining temperature gradient in increasing order of magnitude was refractory layer and insulation layer. It was indicated that the results of combination optimization of aluminum holding furnace linings were valid and feasible, and its thermo-physical mechanism and cost characteristics were reasonably revealed.
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