静脉留置针留置时间与静脉血管的炎症反应相关性研究

目的研究静脉留置针在不同留置时间与静脉血管的炎症反应相关性。方法将种系相同,体重相近的大耳新西兰健康白兔随机分成两组,取其双耳内外侧的耳缘静脉作为实验血管,进行静脉留置针输液,以相同的速度分别输入等量的0.9%氯化钠注射液,每日1次。输毕后用肝素盐水封管,分别保留至72~96h和120~168h后,以一穿刺点为中心取长2cm,宽1cm的活体标本做病理切片,观察静脉血管的病理变化。结果血管周围组织大部均有不同程度的炎症反应。静脉留置针保留72~96h后,血管内中重度炎症发生率24%;静脉留置针保留120~168h后,血管内中重度炎症发生率60%,明显高于保留72~96h的血管。结论建议静脉留置针保留时间应在96h以内。     

Bare Metal Stents on Resveratrol-Coated Balloons in Porcine Coronary and Peripheral Arteries

Balloon angioplasty and stent implantation are standard techniques to reopen stenotic vessels. Often, balloons or stents coated with cytostatic drugs are used to prevent re-occlusion of the arteries. Resveratrol, which is known for its numerous beneficial effects on cardiovascular health, is used as an antioxidant additive on paclitaxel-coated balloon catheters. What is still unclear is whether resveratrol-only balloon coating in combination with a bare metal stent (BMS) also has positive effects on vascular healing. Here, we analyzed neointimal thickening, fibrin deposition, inflammation, vasa vasorum density, and reendothelialization after implantation of BMS via a resveratrol coated balloon approach in a porcine model. In general, resveratrol treatment did not result in significantly altered responses compared to the control group in peripheral arteries. In coronary arteries, an increase in vasa vasorum density became evident three days after resveratrol treatment compared to the control group and abolished up to day 7. Significant effects of the resveratrol treatment on the fibrin score or intima-media area were transient and restricted to either peripheral or coronary arteries. In conclusion, local single-dose resveratrol treatment via a resveratrol-only coated balloon and BMS approach did not lead to adverse systemic or local effects, but also no significant beneficial effects on vascular healing were detected in the current study.     

深度迁移学习在古筝品质分级中的应用

深度学习和迁移学习的兴起为树种识别提供了新方向,然而其在同树种内不同品质间木材识别仍存在挑战。为改善古筝面板品质分级现状,设计了一种深度残差网络模型。首先将数据集进行划分并采用数据增强技术来扩充训练样本,然后将ImageNet上经过预训练的模型迁移到该问题上。为高效提取到板材图像特征,在预训练模型后新增深层特征提取部分,其融合了残差连接和深度可分离卷积,不仅可增强特征重利用率和缓解梯度消失,而且有利于提取到图像深层特征。最后为提升模型在训练过程中的鲁棒性,使用LeakyReLU函数代替ReLU函数避免神经元死亡问题。该方法在泡桐导管图像数据集上测试精度达到了92.8%,对比其他主流方法,该模型可节省古筝品质分级时间,提高识别精度。     

振动测试异常值的原因分析

针对某型飞机在振动测试过程中，测试结果异常值的产生、筛选和剔除等问题进行原因分析。运用实验比较和类比排除的方法，论证振动传感器带电时对测试结果的影响。     

基于BP神经网络的导管接头注塑工艺参数优化

以医用介入导管接头为研究对象,基于塑料成型理论在Moldflow软件中进行导管接头模流分析,通过正交实验极差分析,确定了注塑工艺参数对导管接头缩痕指数的影响趋势,得到最佳工艺参数组合.针对实际生产中出现的缩痕缺陷,建立导管接头缩痕指数的BP神经网络参数模型,并用遗传算法进行优化,同时对结果进行仿真模拟,得到缩痕指数为0...     

Advances in Biomaterials and Technologies for Vascular Embolization

Minimally invasive transcatheter embolization is a common nonsurgical procedure in interventional radiology used for the deliberate occlusion of blood vessels for the treatment of diseased or injured vasculature. A wide variety of embolic agents including metallic coils, calibrated microspheres, and liquids are available for clinical practice. Additionally, advances in biomaterials, such as shape‐memory foams, biodegradable polymers, and in situ gelling solutions have led to the development of novel preclinical embolic agents. The aim here is to provide a comprehensive overview of current and emerging technologies in endovascular embolization with respect to devices, materials, mechanisms, and design guidelines. Limitations and challenges in embolic materials are also discussed to promote advancement in the field.     

Comparison of side hole versus non side hole high flow hemodialysis catheters

Current literature suggests that side holes may be detrimental to dialysis catheter performance. Today, these catheters are primarily available with side holes. The purpose of this study was to compare flow rates, infection rate, and survival of side hole vs. non side hole hemodialysis catheters. Over a 16-month period patients were arbitrarily assigned to either a 14.5 F MAHURKAR MAXID cuffed dual lumen tunneled catheter with side holes or a 14.5 F MAHURKAR MAXID cuffed dual lumen tunneled catheter without side holes ("non side hole catheters"). We performed a retrospective analysis of catheter flow rates, patency, catheter survival, and catheter-related infections. Information was gathered for the life of the catheter or up to 28 weeks. A total of 54 patients were enrolled in the study. Thirty-seven of 54 (68%) patients received a catheter with side holes for a total of 3,930 catheter days and 17/54 (32%) received a similar catheter without side holes for a total of 2,188 catheter days. Catheter infection necessitating removal of the catheter occurred in 10/37 catheters with side holes and 1/17 without side holes. Infection rates per 1,000 catheter days were 2.545 with side holes and 0.254 without side holes (p<0.001). Slightly improved catheter survival (p<0.05) was recorded with the non side hole catheters. No insertion complication (e.g., air embolization, bleeding, or kinking) occurred with either catheter. One catheter without side holes had to be repositioned 5 days after insertion because of poor flows. No significant difference was recorded in mean blood flow rates between the catheters. Results indicate reduced catheter infection rate in hemodialysis patients with the use of non side hole dual lumen tunneled cuffed catheters.     

Phospholipids and Fatty Acids Affect the Colonization of Urological Catheters by Proteus mirabilis

Proteus mirabilis-mediated CAUTIs are usually initiated by the adherence of bacteria to a urinary catheter surface. In this paper, three isolates of different origin and exhibiting different adhesion abilities were investigated in search of any changes in lipidome components which might contribute to P. mirabilis adhesion to catheters. Using GC-MS and LC-MS/MS techniques, 21 fatty acids and 27 phospholipids were identified in the examined cells. The comparison of the profiles of phospholipids and fatty acids obtained for catheter-attached cells and planktonic cells of the pathogens indicated C11:0 and PE 37:2 levels as values which could be related to P. mirabilis adhesion to a catheter, as well as cis C16:1, PE 32:0, PE 33:0, PE 38:2, PG 33:1, PG 34:0, PE 30:1, PE 32:1 and PG 30:2 levels as values which could be associated with cell hydrophobicity. Based on DiBAC₄ (3) fluorescence intensity and an affinity to p-xylene, it was found that the inner membrane depolarization, as well as strong cell-surface hydrophobicity, were important for P. mirabilis adhesion to a silicone catheter. A generalized polarization of Laurdan showed lower values for P. mirabilis cells attached to the catheter surface than for planktonic cells, suggesting lower packing density of membrane components of the adherent cells compared with tightly packed, stiffened membranes of the planktonic cells. Taken together, these data indicate that high surface hydrophobicity, fluidization and depolarization of P. mirabilis cell membranes enable colonization of a silicone urinary catheter surface.     

Tunneled-cuffed catheter implanted into the accessory hemiazygos vein because of occlusion of the left innominate vein

Hemodialyzed patients are at risk of multiple catheterizations. Nephrologists performing such procedures need to be familiar with congenital and acquired vascular abnormalities. We describe a successful insertion and use of a cuffed-tunneled catheter in a patient with unusual anatomy of the central venous system. Computed tomography angiography revealed thrombosis of the right subclavian vein and bilateral occlusion of innominate veins. The left internal jugular and subclavian veins joined to form a large vessel that drained through the accessory hemiazygos and azygos veins into the superior vena cava. The catheter was implanted through the left internal jugular vein into the accessory hemiazygos vein. The presented case demonstrates that the catheter can be implanted into distended collateral, especially when no other location is possible.