Tissue factor and PAR1 promote microbiota-induced intestinal vascular remodelling

The gut microbiota is a complex ecosystem that has coevolved with host physiology. Colonization of germ-free (GF) mice with a microbiota promotes increased vessel density in the small intestine, but little is known about the mechanisms involved. Tissue factor (TF) is the membrane receptor that initiates the extrinsic coagulation pathway, and it promotes developmental and tumour angiogenesis. Here we show that the gut microbiota promotes TF glycosylation associated with localization of TF on the cell surface, the activation of coagulation proteases, and phosphorylation of the TF cytoplasmic domain in the small intestine. Anti-TF treatment of colonized GF mice decreased microbiota-induced vascular remodelling and expression of the proangiogenic factor angiopoietin-1 (Ang-1) in the small intestine. Mice with a genetic deletion of the TF cytoplasmic domain or with hypomorphic TF (F3) alleles had a decreased intestinal vessel density. Coagulation proteases downstream of TF activate protease-activated receptor (PAR) signalling implicated in angiogenesis. Vessel density and phosphorylation of the cytoplasmic domain of TF were decreased in small intestine from PAR1-deficient (F2r(-/-)) but not PAR2-deficient (F2rl1(-/-)) mice, and inhibition of thrombin showed that thrombin-PAR1 signalling was upstream of TF phosphorylation. Thus, the microbiota-induced extravascular TF-PAR1 signalling loop is a novel pathway that may be modulated to influence vascular remodelling in the small intestine.     

一种基于信息融合与运动域分割的手势运动方向识别方法

手势识别中,除手的分割是个难题外,在视频流中,手势有效动作起止帧的判定也是一个急待解决的问题。将图像的肤色与运动信息结合,分割出手,建立手势运动的历史图(Motion History Image,MHI),提出了一种MHI与改进的运动能量图(Improved Motion Energy Image,IMEI)结合的机制,判定有效手势运动的起止帧,最后建立有效手势运动的MHI;同时提出改进图像梯度向量算法用于手势运动方向(上,下,左,右)识别。实验表明,对于有效手势运动起止帧的正确判断率一般可达90%以上,有效手势识别率达96%以上,手势交互自然顺畅。     

光伏专业《大学化学》课程双语教学的探讨

大学化学是光伏专业的重要专业基础课程。大学化学在光伏专业进行双语教学时具有优势与必要性,通过教学资源的选挣与建设与教学方法的选择,可以开展具有光伏专业特色的大学化学双语教学。     

基于局域网的信息系统安全监控体系研究

针对某局域网的教务管理信息系统的安全性进行了全面的分析,提出了该系统所需采用的安全策略和方法,设计了系统权限分配和用户认证、记录追踪、数据库连接的通讯协议、启用C2级审核、警报系统等程序,实现了SLTMIS完整有效的安全监控体系.     

距下关节CT序列图像分割及信息提取研究

提出一种基于图像的距下关节信息提取方法.采用最大类间方差法与交互式数学形态学方法相结合的手段从活体后足CT序列图像中分割出距骨和跟骨,以移动立方体法重建距下关节复合体的表面并以动画方式显示距骨和跟骨的结构信息,提出力矩主轴法计算距骨和跟骨相对于参考系的旋转方向及它们之间的夹角.与其他方法相比较和仿真模型论证的结果表明,基于图像的距下关节信息提取方法具有较高的准确性和精度.