Platelet concentration near the blood vessel wall is one of the major factors in the adhesion of platelets to the wall.In our previous studies,it was found that swirling flows could suppress platelet adhesion in small-caliber artificial grafts and end-to-end anastomoses.In order to better understand the beneficial effect of the swirling flow,we numerically analyzed the near-wall concentration distribution of platelets in a straight tube and a sudden tubular expansion tube under both swirling flow and normal flow conditions.The numerical models were created based on our previous experimental studies.The simulation results revealed that when compared with the normal flow,the swirling flow could significantly reduce the near-wall concentration of platelets in both the straight tube and the expansion tube.The present numerical study therefore indicates that the reduction in platelet adhesion under swirling flow conditions in small-caliber arterial grafts,or in end-to-end anastomoses as observed in our previous experimental study,was possibly through a mechanism of platelet transport,in which the swirling flow reduced the near-wall concentration of platelets.
采用BRB-ArrayTools分析GEO数据库中肺和心脏细胞在缺氧环境下不同时间段的差异表达基因,获得肺细胞差异表达基因39个,心脏细胞差异表达基因66个,其中,有部分差异表达基因相同,但更多是不同的响应基因;差异表达基因随缺氧时间延长达到相对稳定.通过GeneCodis聚类这些差异表达基因参与的分子功能和生物学过程,其功能涉及血管生成、NAD+活性、跨膜转运作用、还原酶作用、氧化还原过程及氧化应激等.用本文挖掘找出缺氧调控的microRNA(miRNA),用miTALOS分析缺氧调控miR-NA参与的生物信号通路,这些信号通路主要有血管内皮生长因子(vascular endothelial growth-factor,VEGF)受体功能、Wnt和MAPK(mitogen-activated protein kinase)信号通路.结果表明,挖掘和整合生物基因芯片有效信息资源,可为深入研究缺氧效应的分子机理提供新思路.
