钍基熔盐堆(Thorium Molten Salt Reactor-Liquid Fuel,TMSR-LF1)回路管道最高运行温度达650℃,高温服役下的管道蠕变-疲劳损伤分析及评定至关重要。目前仅ASME-BPVC-III-5-HBB规范中有适用于高温核一级管道的蠕变-疲劳损伤暂行评定方法...钍基熔盐堆(Thorium Molten Salt Reactor-Liquid Fuel,TMSR-LF1)回路管道最高运行温度达650℃,高温服役下的管道蠕变-疲劳损伤分析及评定至关重要。目前仅ASME-BPVC-III-5-HBB规范中有适用于高温核一级管道的蠕变-疲劳损伤暂行评定方法,但该方法对于复杂管道系统使用起来过于繁琐。本文旨在使用管道分析软件PepS软件实现高温核一级复杂管系的分析与结构完整性评估。首先结合管道结构在多种载荷组合作用下的截面应力状态解析解,进行管道截面应力分析及应力线性化,并将结果与有限元数值解进行对比分析,两者的误差结果基本一致。随后,利用PepS软件对TMSR-LF1回路管道进行了力学分析和结构完整性评估,结其蠕变疲劳损伤结果位于包络线以内,满足蠕变疲劳极限的要求。该研究将管道分析软件与ASME评定规范进行了有效衔接,明确了评定方法,实现了高温核一级复杂管系的蠕变疲劳评估。展开更多
Background Erythropoietin （EPO） and granulocyte colony-stimulating factor （G-CSF） are both potential novel therapeutics for use after myocardial infarction （MI）.However,their underlying mechanisms remain unclear...Background Erythropoietin （EPO） and granulocyte colony-stimulating factor （G-CSF） are both potential novel therapeutics for use after myocardial infarction （MI）.However,their underlying mechanisms remain unclear and the efficacy of monotherapy with EPO or G-CSF is also controversial.Therefore,we investigated the effects of combined treatment with EPO and G-CSF on neovascularization and cardiac function in post-infarction rats and explored the potential mechanisms.Methods Four groups of rats were used：control （saline injection after MI,i.h.）,EPO （a single dose of 5 000 IU/kg after MI,i.h.）,G-CSF （a dose of 50 μg· kg-1· d-1 for 5 days after MI,i.h.）,and both EPO and G-CSF （EPO＋G-CSF,using the same regiment as above）.Cardiac function was assessed by echocardiography before and 1 day,7 days,14 days and 21 days after MI.CD34＋/Flk-1＋ cells in the peripheral blood were evaluated by flow cytometry before and 3 days,5 days and 7 days after MI.The infarct area and angiogenesis in the peri-infarct area were analyzed.The mRNA and protein expression of vascular endothelial growth factor （VEGF） and stromal-derived factor-1α （SDF-1α） in the peri-infarct area were detected by real-time quantitative RT-PCR and Western blotting.Results Compared with the control and monotherapy groups,the EPO＋G-CSF group had significantly increased CD34＋/ Flk-1＋ endothelial progenitor calls （EPCs）in the peripheral blood （P ＜0.05）,up-regulated VEGF and SDF-1α levels in the peri-infarct region （P ＜0.05）,enhanced capillary density （P ＜0.05）,reduced infarct size （P ＜0.05） and improved cardiac structure and function （P ＜0.05）.G-CSF alone did not dramatically increase EPCs in the peripheral blood,enhance capillary density in the peri-infarct area or reduce infarct size compared with the control group.Conclusions Combined treatment with EPO and G-CSF increased EPCs mobilization,up-regulated VEGF and SDF-1α levels in the post-infarction microenvironment,subsequently enhanced neovascularization in the peri-infarct region and reduced infarct size.All factors contributed to its beneficial effects on cardiac function in post-infarction rats.展开更多
文摘钍基熔盐堆(Thorium Molten Salt Reactor-Liquid Fuel,TMSR-LF1)回路管道最高运行温度达650℃,高温服役下的管道蠕变-疲劳损伤分析及评定至关重要。目前仅ASME-BPVC-III-5-HBB规范中有适用于高温核一级管道的蠕变-疲劳损伤暂行评定方法,但该方法对于复杂管道系统使用起来过于繁琐。本文旨在使用管道分析软件PepS软件实现高温核一级复杂管系的分析与结构完整性评估。首先结合管道结构在多种载荷组合作用下的截面应力状态解析解,进行管道截面应力分析及应力线性化,并将结果与有限元数值解进行对比分析,两者的误差结果基本一致。随后,利用PepS软件对TMSR-LF1回路管道进行了力学分析和结构完整性评估,结其蠕变疲劳损伤结果位于包络线以内,满足蠕变疲劳极限的要求。该研究将管道分析软件与ASME评定规范进行了有效衔接,明确了评定方法,实现了高温核一级复杂管系的蠕变疲劳评估。
基金This work was supported m part by the National Natural Science Foundation of China （No. 81100071, 81371632, 81270252 and 81070160）, the Heilongjiang Province Foundation for Returness （No. LC08C36）, the Heilongjinang Province Outstanding Youth Foundation （No. JC201208）, the Collegiate Changjiang Scholar Reserve Support Plan of Heilongjiang Province （No. 2013 CJHB001）, the National Basic Research Program of China （973 program） （No. 2014CB542401）, and the Natural Science Foundation of Heilongjiang Province （No. D201121, GC09C408-2） Conflicts of interest： none.Acknowledgments： Part of the work was carried out in the Department of Cardiovascular Medicine in Nippon Medical School and presented in the 20th World Congress of the ISHR 2010 in Kyoto. Authors thank Drs. Gen Takagi and Koichi Miyake for technical assistance.
文摘Background Erythropoietin （EPO） and granulocyte colony-stimulating factor （G-CSF） are both potential novel therapeutics for use after myocardial infarction （MI）.However,their underlying mechanisms remain unclear and the efficacy of monotherapy with EPO or G-CSF is also controversial.Therefore,we investigated the effects of combined treatment with EPO and G-CSF on neovascularization and cardiac function in post-infarction rats and explored the potential mechanisms.Methods Four groups of rats were used：control （saline injection after MI,i.h.）,EPO （a single dose of 5 000 IU/kg after MI,i.h.）,G-CSF （a dose of 50 μg· kg-1· d-1 for 5 days after MI,i.h.）,and both EPO and G-CSF （EPO＋G-CSF,using the same regiment as above）.Cardiac function was assessed by echocardiography before and 1 day,7 days,14 days and 21 days after MI.CD34＋/Flk-1＋ cells in the peripheral blood were evaluated by flow cytometry before and 3 days,5 days and 7 days after MI.The infarct area and angiogenesis in the peri-infarct area were analyzed.The mRNA and protein expression of vascular endothelial growth factor （VEGF） and stromal-derived factor-1α （SDF-1α） in the peri-infarct area were detected by real-time quantitative RT-PCR and Western blotting.Results Compared with the control and monotherapy groups,the EPO＋G-CSF group had significantly increased CD34＋/ Flk-1＋ endothelial progenitor calls （EPCs）in the peripheral blood （P ＜0.05）,up-regulated VEGF and SDF-1α levels in the peri-infarct region （P ＜0.05）,enhanced capillary density （P ＜0.05）,reduced infarct size （P ＜0.05） and improved cardiac structure and function （P ＜0.05）.G-CSF alone did not dramatically increase EPCs in the peripheral blood,enhance capillary density in the peri-infarct area or reduce infarct size compared with the control group.Conclusions Combined treatment with EPO and G-CSF increased EPCs mobilization,up-regulated VEGF and SDF-1α levels in the post-infarction microenvironment,subsequently enhanced neovascularization in the peri-infarct region and reduced infarct size.All factors contributed to its beneficial effects on cardiac function in post-infarction rats.
