本研究探讨慢病毒质粒pGC FU-RFP-LV标记的小鼠骨实质来源的间充质干细胞在小鼠肺组织和骨髓中的分布。将感染效率为78%的慢病毒感染小鼠MSC,尔后将感染后的MSC以1×106个/只的浓度经小鼠尾静脉植入到BALB/c小鼠体内。随机将小鼠按...本研究探讨慢病毒质粒pGC FU-RFP-LV标记的小鼠骨实质来源的间充质干细胞在小鼠肺组织和骨髓中的分布。将感染效率为78%的慢病毒感染小鼠MSC,尔后将感染后的MSC以1×106个/只的浓度经小鼠尾静脉植入到BALB/c小鼠体内。随机将小鼠按照1、2、5、7 d 4个时间点分为4组。在各时间点取小鼠肺组织并制成冰冻切片及骨髓涂片,观察其分布情况。结果表明:慢病毒感染后的MSC经免疫表型分析和诱导分化检测均符合MSC的表型及生物学特征。以最适病毒滴度MOI=50感染小鼠MSC后,细胞生长状态无明显改变。通过荧光显微镜观察小鼠第1、2、5、7天MSC在骨髓中分布为(0.50±0.20),(0.67±0.23),(0.53±0.14),(0.33±0.16);在肺组织中分布为(0.55±0.15),(0.47±0.13),(0.29±0.13),(0.26±0.08)。结论:MSC在第1天主要分布在肺组织内(P<0.05),而在第2天主要分布在骨髓中(P<0.05)。小鼠骨实质MSC分布浓度与RFP基因表达及MSC在肺组织和骨髓中定植情况有关。展开更多
The degradation behavior of aggregate skeleton in stone matrix asphalt mixture was investigated based on theoretical analysis, laboratory test and field materials evaluation. A stress-transfer model was established to...The degradation behavior of aggregate skeleton in stone matrix asphalt mixture was investigated based on theoretical analysis, laboratory test and field materials evaluation. A stress-transfer model was established to provide the fundamental understanding of the stress distribution and degradation mechanism of stone matrix asphalt (SMA) aggregate skeleton. Based on the theoretical analysis, crushing test and superpave gyratory compactor (SGC) test were used to evaluate the degradation behavior of aggregate skeleton of SMA. To verify the laboratory test results, gradation analysis was also conducted for the field materials extracted from SMA pavements after long-time service. The results indicate that the degradation of SMA aggregate skeleton is not random but has fixed internal trend and mechanism. Special rule is found for the graded fine aggregates generated from coarse aggregate breakdown and the variation of 4.75 mm aggregate is found to play a key role in the graded aggregates to form well-balanced skeleton to bear external loading. The variation of 4.75 mm aggregate together with the breakdown ratio of aggregate gradation can be used to characterize the degradation behavior of aggregate skeleton. The crushing test and SGC test are proved to be promising in estimating the degradation behavior of SMA skeleton.展开更多
文摘本研究探讨慢病毒质粒pGC FU-RFP-LV标记的小鼠骨实质来源的间充质干细胞在小鼠肺组织和骨髓中的分布。将感染效率为78%的慢病毒感染小鼠MSC,尔后将感染后的MSC以1×106个/只的浓度经小鼠尾静脉植入到BALB/c小鼠体内。随机将小鼠按照1、2、5、7 d 4个时间点分为4组。在各时间点取小鼠肺组织并制成冰冻切片及骨髓涂片,观察其分布情况。结果表明:慢病毒感染后的MSC经免疫表型分析和诱导分化检测均符合MSC的表型及生物学特征。以最适病毒滴度MOI=50感染小鼠MSC后,细胞生长状态无明显改变。通过荧光显微镜观察小鼠第1、2、5、7天MSC在骨髓中分布为(0.50±0.20),(0.67±0.23),(0.53±0.14),(0.33±0.16);在肺组织中分布为(0.55±0.15),(0.47±0.13),(0.29±0.13),(0.26±0.08)。结论:MSC在第1天主要分布在肺组织内(P<0.05),而在第2天主要分布在骨髓中(P<0.05)。小鼠骨实质MSC分布浓度与RFP基因表达及MSC在肺组织和骨髓中定植情况有关。
基金Project(51008075) supported by the National Natural Science Foundation of ChinaProject(2006AA11Z110) supported by the National High Technology Research and Development Program of China
文摘The degradation behavior of aggregate skeleton in stone matrix asphalt mixture was investigated based on theoretical analysis, laboratory test and field materials evaluation. A stress-transfer model was established to provide the fundamental understanding of the stress distribution and degradation mechanism of stone matrix asphalt (SMA) aggregate skeleton. Based on the theoretical analysis, crushing test and superpave gyratory compactor (SGC) test were used to evaluate the degradation behavior of aggregate skeleton of SMA. To verify the laboratory test results, gradation analysis was also conducted for the field materials extracted from SMA pavements after long-time service. The results indicate that the degradation of SMA aggregate skeleton is not random but has fixed internal trend and mechanism. Special rule is found for the graded fine aggregates generated from coarse aggregate breakdown and the variation of 4.75 mm aggregate is found to play a key role in the graded aggregates to form well-balanced skeleton to bear external loading. The variation of 4.75 mm aggregate together with the breakdown ratio of aggregate gradation can be used to characterize the degradation behavior of aggregate skeleton. The crushing test and SGC test are proved to be promising in estimating the degradation behavior of SMA skeleton.
