用锁口管法施工钻孔咬合桩

针对钻孔咬合桩围护结构在施工中需钻掉部分素混凝土,造成材料多耗且为施工带来不便的缺点,介绍了锁口管法,通过钻孔咬合桩的施工计划,施工方案以及锁口管设计,钻机选择,施工工艺,施工中的注意事项几方面论述了锁口管法可以避免以上缺点,证明应用此法可快速,优质地完成钻孔咬合桩墙围护结构。     

Regulation and Release of Vasoactive Endoglin by Brain Endothelium in Response to Hypoxia/Reoxygenation in Stroke

In large vessel occlusion stroke, recanalization to restore cerebral perfusion is essential but not necessarily sufficient for a favorable outcome. Paradoxically, in some patients, reperfusion carries the risk of increased tissue damage and cerebral hemorrhage. Experimental and clinical data suggest that endothelial cells, representing the interface for detrimental platelet and leukocyte responses, likely play a crucial role in the phenomenon referred to as ischemia/reperfusion (I/R)-injury, but the mechanisms are unknown. We aimed to determine the role of endoglin in cerebral I/R-injury; endoglin is a membrane-bound protein abundantly expressed by endothelial cells that has previously been shown to be involved in the maintenance of vascular homeostasis. We investigated the expression of membranous endoglin (using Western blotting and RT-PCR) and the generation of soluble endoglin (using an enzyme-linked immunosorbent assay of cell culture supernatants) after hypoxia and subsequent reoxygenation in human non-immortalized brain endothelial cells. To validate these in vitro data, we additionally examined endoglin expression in an intraluminal monofilament model of permanent and transient middle cerebral artery occlusion in mice. Subsequently, the effects of recombinant human soluble endoglin were assessed by label-free impedance-based measurement of endothelial monolayer integrity (using the xCELLigence DP system) and immunocytochemistry. Endoglin expression is highly inducible by hypoxia in human brain endothelial monolayers in vitro, and subsequent reoxygenation induced its shedding. These findings were corroborated in mice during MCAO; an upregulation of endoglin was displayed in the infarcted hemispheres under occlusion, whereas endoglin expression was significantly diminished after transient MCAO, which is indicative of shedding. Of note is the finding that soluble endoglin induced an inflammatory phenotype in endothelial monolayers. The treatment of HBMEC with endoglin resulted in a decrease in transendothelial resistance and the downregulation of VE-cadherin. Our data establish a novel mechanism in which hypoxia triggers the initial endothelial upregulation of endoglin and subsequent reoxygenation triggers its release as a vasoactive mediator that, when rinsed into adjacent vascular beds after recanalization, can contribute to cerebral reperfusion injury.     

系统振荡又发生短路故障时距离保护的动作行为分析

对几种常见的距离保护振荡闭锁原理进行简要分析,指出各种原理的优缺点,并提出今后努力的方向。     

Quadtree-based eigendecomposition for pose estimation in the presence of occlusion and background clutter

Eigendecomposition-based techniques are popular for a number of computer vision problems, e.g., object and pose estimation, because they are purely appearance based and they require few on-line computations. Unfortunately, they also typically require an unobstructed view of the object whose pose is being detected. The presence of occlusion and background clutter precludes the use of the normalizations that are typically applied and significantly alters the appearance of the object under detection. This work presents an algorithm that is based on applying eigendecomposition to a quadtree representation of the image dataset used to describe the appearance of an object. This allows decisions concerning the pose of an object to be based on only those portions of the image in which the algorithm has determined that the object is not occluded. The accuracy and computational efficiency of the proposed approach is evaluated on 16 different objects with up to 50% of the object being occluded and on images of ships in a dockyard.

增强现实中基于自然特征的实时跟踪方法

在增强现实系统的复杂场景中,对目标的实时跟踪受到场景中诸多因素的制约,导致实时跟踪方法效率低且不准确,为此提出一种基于自然特征的实时跟踪方法。设计了一种螺旋分割模型,对捕获的图像进行螺旋分割,利用SURF算法在分割子块中提取特征点,并进行匹配。在对目标进行跟踪定位时,利用前一帧来预测当前帧目标出现的位置,以减少SURF算法的扫描区域,加速系统运算效率。实验中分别对场景光线强弱、视点和仿射变化以及目标被部分遮挡等不同情况进行测试,该方法均表现出较高的跟踪效率。     

Nicotinamide Mononucleotide Protects against Retinal Dysfunction in a Murine Model of Carotid Artery Occlusion

Cardiovascular abnormality-mediated retinal ischemia causes severe visual impairment. Retinal ischemia is involved in enormous pathological processes including oxidative stress, reactive gliosis, and retinal functional deficits. Thus, maintaining retinal function by modulating those pathological processes may prevent or protect against vision loss. Over the decades, nicotinamide mononucleotide (NMN), a crucial nicotinamide adenine dinucleotide (NAD⁺) intermediate, has been nominated as a promising therapeutic target in retinal diseases. Nonetheless, a protective effect of NMN has not been examined in cardiovascular diseases-induced retinal ischemia. In our study, we aimed to investigate its promising effect of NMN in the ischemic retina of a murine model of carotid artery occlusion. After surgical unilateral common carotid artery occlusion (UCCAO) in adult male C57BL/6 mice, NMN (500 mg/kg/day) was intraperitoneally injected to mice every day until the end of experiments. Electroretinography and biomolecular assays were utilized to measure ocular functional and further molecular alterations in the retina. We found that UCCAO-induced retinal dysfunction was suppressed, pathological gliosis was reduced, retinal NAD⁺ levels were preserved, and the expression of an antioxidant molecule (nuclear factor erythroid-2-related factor 2; Nrf2) was upregulated by consecutive administration of NMN. Our present outcomes first suggest a promising NMN therapy for the suppression of cardiovascular diseases-mediated retinal ischemic dysfunction.     

混合高斯模型结合五帧差分的运动目标检测

在复杂背景下,光照变化、目标短暂遮挡以及背景运动等因素会导致运动目标检测精度较低.提出一种结合改进混合高斯模型和改进五帧差分的运动目标检测算法,首先在混合高斯模型中加入自适应学习率以及背景学习速率更新策略有效解决传统背景更新速率恒定而出现的残影现象;然后利用改进的五帧差分法克服运动目标短暂遮挡问题,并加入光照阈值判别因...     

多窗口目标跟踪算法

目标在复杂环境下运动,特征会受到光照、摄像机角度等因素影响,并且目标可能会被自身其他部分或者场景物体遮挡,为此,提出一种多窗口概念的视频目标跟踪算法,基本思想就是将目标用多个不同的窗口表示,每一个窗口对应一个跟踪器.这些窗口之间可以存在重叠,也可以包含被跟踪目标上下文信息,如在人脸跟踪中,有些跟踪窗口可以包含颈部信息、上衣颜色信息.然后利用这些窗口之间的位置关系以及在后继跟踪过程中的相似度来估计目标的真实位置.通过实验可以看出,提出的多窗口均值移动跟踪算法可以提高系统在遮挡、光照变化等复杂条件下的跟踪性能.     

视频增强的新方法

本文使用张量的方法推导了基于仿射空间的免标定增强现实方法,该方法不需要像机的标定参数和环境对象的3D位置信息就可实现视频增强。同时,本文也提出了在仿射空间解决增强现实中遮挡问题的新方法,给出了基于免标定增强现实的视频增强主要想法和应用实例。结果表明,这个方法是可行的。     

基于秩4约束的遮挡点恢复方法

提出了一种基于秩4约束的遮挡点恢复方法.该方法 首先假设所有的遮挡点及深度因子已知,利用所有遮挡点及深度因子组成一个秩4矩阵的特 性,构造一个投影矩阵,并利用该投影矩阵求得所有的遮挡点及深度因子.然后将求得的遮 挡点及深度因子代替图像中的遮挡点和深度因子,再求投影矩阵.经过多次迭代,最后求得 遮挡点的真实图像位置.该方法的优点是平等地看待所有的图像及图像点.模拟实验和真实实 验表明,该方法具有鲁棒性好、收敛性好及误差小等优点.