目的:观察复健片对大脑中动脉闭塞(MCAO)模型大鼠未损伤侧大脑皮质生长相关蛋白43(GAP-43)表达的影响,探讨复健片促进未损伤侧大脑重塑的分子基础。方法:110只SD雄性大鼠,按随机数字表法随机分为假手术组20只和造模组90只。根据处死时...目的:观察复健片对大脑中动脉闭塞(MCAO)模型大鼠未损伤侧大脑皮质生长相关蛋白43(GAP-43)表达的影响,探讨复健片促进未损伤侧大脑重塑的分子基础。方法:110只SD雄性大鼠,按随机数字表法随机分为假手术组20只和造模组90只。根据处死时间点及干预方法不同,假手术组及模型组各分为术后1周、2周、3周、4周和5周五个亚组,药物组分为术后2周、3周、4周和5周四个亚组。造模组采用线栓法制备大鼠右侧大脑中动脉永久性闭塞(MCAO)模型,药物组术后1周末按5.9 m L/kg给予复健片浓缩液灌胃,采用横木行走实验(BWT)评定各组大鼠运动功能;TTC染色观察梗死灶部位;采用Western blot法检测大鼠左侧大脑GAP-43的表达。结果:术后1周末,模型组较假手术组GAP-43表达增高;术后2周末,模型组和药物组GAP-43表达均较假手术组增高,其中药物组增高更为显著;术后3周、4周末延续术后2周末的趋势;术后5周,药物组仍高于模型组,模型组与假手术组已无显著差异。与此同时,BWT评分结果示,模型组药物组BWT评分在术后1、2、3、4周末均升高(P<0.01),其中药物组的升高更显著,直至术后5周末,药物组与假手术组已无明显差异(P>0.05)。TTC染色表明术后5周末MCAO大鼠梗死灶体积无差异。结论:复健片通过增加MCAO模型大鼠健侧大脑GAP-43表达,从而促进神经突起生长,继而促进未损伤侧大脑重塑以改善大鼠缺血性脑卒中后的运动功能恢复。展开更多
To gain insight into the inelastic behavior of piles, the response of a vertical pile embedded in dry sand and subjected to cyclic lateral loading was studied experimentally in centrifuge tests conducted in Laboratoir...To gain insight into the inelastic behavior of piles, the response of a vertical pile embedded in dry sand and subjected to cyclic lateral loading was studied experimentally in centrifuge tests conducted in Laboratoire Central des Ponts et Chaussees. Three types of cyclic loading were applied, two asymmetric and one symmetric with respect to the unloaded pile. An approximately square-root variation of soil stiffness with depth was obtained from indirect in-flight density measurements, laboratory tests on reconstituted samples, and well-established empirical correlations. The tests were simulated using a cyclic nonlinear Winkler spring model, which describes the full range of inelastic phenomena, including separation and re-attachment of the pile from and to the soil. The model consists of three mathematical expressions capable of reproducing a wide variety of monotonic and cyclic experimentalp-y curves. The physical meaning of key model parameters is graphically explained and related to soil behavior. Comparisons with the centrifuge test results demonstrate the general validity of the model and its ability to capture several features of pile-soil interaction, including： soil plastification at an early stage of loading, ＂pinching＂ behavior due to the formation of a relaxation zone around the upper part of the pile, and stiffness and strength changes due to cyclic loading. A comparison of the p-y curves derived from the test results and the proposed model, as well as those from the classical curves of Reese et al. （1974） for sand, is also presented.展开更多
参照IEC79《Method of Test for Ascertainment of Maximum Experimental Safe Gap》以及GB 3836.11—2008《由隔爆外壳"d"保护的设备最大试验安全间隙测定方法》,并将标准中的手动间隙调整结构自动化,设计开发了一套自动化...参照IEC79《Method of Test for Ascertainment of Maximum Experimental Safe Gap》以及GB 3836.11—2008《由隔爆外壳"d"保护的设备最大试验安全间隙测定方法》,并将标准中的手动间隙调整结构自动化,设计开发了一套自动化程度高的可燃气体(或蒸汽)的最大试验安全间隙测试装置。对不同浓度的C3H8气体最大试验安全间隙值进行了测定并与标准值进行了比较。结果表明,该装置具有较高精度。展开更多
文摘目的:观察复健片对大脑中动脉闭塞(MCAO)模型大鼠未损伤侧大脑皮质生长相关蛋白43(GAP-43)表达的影响,探讨复健片促进未损伤侧大脑重塑的分子基础。方法:110只SD雄性大鼠,按随机数字表法随机分为假手术组20只和造模组90只。根据处死时间点及干预方法不同,假手术组及模型组各分为术后1周、2周、3周、4周和5周五个亚组,药物组分为术后2周、3周、4周和5周四个亚组。造模组采用线栓法制备大鼠右侧大脑中动脉永久性闭塞(MCAO)模型,药物组术后1周末按5.9 m L/kg给予复健片浓缩液灌胃,采用横木行走实验(BWT)评定各组大鼠运动功能;TTC染色观察梗死灶部位;采用Western blot法检测大鼠左侧大脑GAP-43的表达。结果:术后1周末,模型组较假手术组GAP-43表达增高;术后2周末,模型组和药物组GAP-43表达均较假手术组增高,其中药物组增高更为显著;术后3周、4周末延续术后2周末的趋势;术后5周,药物组仍高于模型组,模型组与假手术组已无显著差异。与此同时,BWT评分结果示,模型组药物组BWT评分在术后1、2、3、4周末均升高(P<0.01),其中药物组的升高更显著,直至术后5周末,药物组与假手术组已无明显差异(P>0.05)。TTC染色表明术后5周末MCAO大鼠梗死灶体积无差异。结论:复健片通过增加MCAO模型大鼠健侧大脑GAP-43表达,从而促进神经突起生长,继而促进未损伤侧大脑重塑以改善大鼠缺血性脑卒中后的运动功能恢复。
基金EU Fifth Framework Program: Environment, Energy and Sustainable Development Research and Technological Development Activity of Generic Nature: The Fight Against Natural and Technological Hazards, Research Project QUAKER Under Contract No. EVG1–CT–2002–00064
文摘To gain insight into the inelastic behavior of piles, the response of a vertical pile embedded in dry sand and subjected to cyclic lateral loading was studied experimentally in centrifuge tests conducted in Laboratoire Central des Ponts et Chaussees. Three types of cyclic loading were applied, two asymmetric and one symmetric with respect to the unloaded pile. An approximately square-root variation of soil stiffness with depth was obtained from indirect in-flight density measurements, laboratory tests on reconstituted samples, and well-established empirical correlations. The tests were simulated using a cyclic nonlinear Winkler spring model, which describes the full range of inelastic phenomena, including separation and re-attachment of the pile from and to the soil. The model consists of three mathematical expressions capable of reproducing a wide variety of monotonic and cyclic experimentalp-y curves. The physical meaning of key model parameters is graphically explained and related to soil behavior. Comparisons with the centrifuge test results demonstrate the general validity of the model and its ability to capture several features of pile-soil interaction, including： soil plastification at an early stage of loading, ＂pinching＂ behavior due to the formation of a relaxation zone around the upper part of the pile, and stiffness and strength changes due to cyclic loading. A comparison of the p-y curves derived from the test results and the proposed model, as well as those from the classical curves of Reese et al. （1974） for sand, is also presented.
文摘参照IEC79《Method of Test for Ascertainment of Maximum Experimental Safe Gap》以及GB 3836.11—2008《由隔爆外壳"d"保护的设备最大试验安全间隙测定方法》,并将标准中的手动间隙调整结构自动化,设计开发了一套自动化程度高的可燃气体(或蒸汽)的最大试验安全间隙测试装置。对不同浓度的C3H8气体最大试验安全间隙值进行了测定并与标准值进行了比较。结果表明,该装置具有较高精度。
