Prompt Determination of the Mechanical Properties of Industrial Polypropylene Sandwich Pipes

A simple and prompt method to determine the mechanical properties of industrial multilayer extrusion polypropylene pipes for a gravity sewer network is suggested. The engineering formulas included for calculating the permissible thickness and relative position of a foam core in the pipes are based on a linear-elastic approximation and the rule of mixtures. The applicability of the approximation was justified experimentally during investigation of the effective tensile characteristics of single- and multilayer pipes and each layer specimen by using traditional tests and finite-element calculations. The results obtained were used to formulate engineering recommendations for calculations of this type.     

Organic and Inorganic Dyes in Polyelectrolyte Multilayer Films

Polyelectrolyte multilayer films are a versatile functionalization method of surfaces and rely on the alternated adsorption of oppositely charged species. Among such species, charged dyes can also be alternated with oppositely charged polymers, which is challenging from a fundamental point of view, because polyelectrolytes require a minimal number of charges, whereas even monovalent dyes can be incorporated during the alternated adsorption process. We will not only focus on organic dyes but also on their inorganic counterparts and on metal complexes. Such films offer plenty of possible applications in dye sensitized solar cells. In addition, dyes are massively used in the textile industry and in histology to stain textile fibers or tissues. However, the excess of non bound dyes poses serious environmental problems. It is hence of the highest interest to design materials able to adsorb such dyes in an almost irreversible manner. Polyelectrolyte multilayer films, owing to their ion exchange behavior can be useful for such a task allowing for impressive overconcentration of dyes with respect to the dye in solution. The actual state of knowledge of the interactions between charged dyes and adsorbed polyelectrolytes is the focus of this review article.     

基于多层修饰电极在便携式恒电位仪系统中的电化学算法优化

为了对多层修饰电极所引起的测量曲线基线偏移进行快速校准,设计一型便携式恒电位仪系统用于基于多层修饰电极的大肠杆菌检测,并提出一种基于多层修饰电极在便携式恒电位仪中的电化学优化算法。首先使用小波算法,通过选择分解层数及阈值,去除检测中的基础噪声干扰;然后使用基线和峰位置校准及重构算法,通过峰位置及基线斜率计算,去除电极修饰中间过程中因多修饰层变化而偏移的特异性误差,基于峰高不变的前提重构和优化循环伏安曲线。结果表明,系统测量下限可达微安(10^-6A)及以下量级,应用该算法后信噪比提高了30%以上,峰位置校准误差控制在1.23%以下,可达到较好的去噪和校准效果。随着国内外基于复杂修饰材料的电化学生物传感检测技术的发展,该算法因其可将测量结果与电极修饰层一一对应、具有快速定性的纵向比较和横向预判优势,将在食品安全领域的电化学快速定量检测中得到广泛应用。     

一种基于多层感知器的房颤心电图检测方法

目的:提出一种基于多层感知器（MLP）的新型房颤识别算法。方法:首先设计一种新型自适应的R波阈值检测算法,然后以R波位置和幅度为特征,MLP为分类器进行正常/房颤心电图识别。MLP的网络参数采用深层置信网络预训练算法进行初始化,最后用误差反向传播算法对MLP网络权重进行调整。结果:在单通道心电图数据集上对正常、房颤心电信号进行分类,本研究方法的灵敏度达96.00%,特异性为84.18%,平均识别率为90.09%。结论:这种基于MLP的心电识别算法准确率高、计算复杂度较低,可为房颤的智能诊断提供一种新方法。     

角膜溃疡多层羊膜移植术后早期组织病理学与临床分析

目的观察角膜溃疡多层羊膜移植术后羊膜与角膜早期组织病理学形态与临床特点。方法角膜溃疡患者23例(23眼),以多层羊膜填塞溃疡面,单层羊膜覆盖角膜表面,10-0线间断缝合于角膜缘。角膜组织行病理学检查,裂隙灯观察角膜溃疡变化,并观察术后并发症。结果 21例患者角膜溃疡愈合;2例患者溃疡穿孔再次行光学性角膜移植术,其中1眼继发青光眼。无其他并发症发生。HE染色羊膜呈染色均一结构,18d多层羊膜排列整齐,层次清晰,角膜基质内少量炎性粒细胞浸润,羊膜表面角膜上皮化;30d多层羊膜彼此融合,层次不清,羊膜与角膜基质界限模糊,少量新生血管形成,角膜厚度均一。结论多层羊膜移植后羊膜与角膜基质可有效整合,增加角膜厚度,阻止溃疡穿孔,抑制炎症,促进溃疡愈合。     

Controlling lipid nanoemulsion digestion using nanolaminated biopolymer coatings

The influence of nanolaminated biopolymer coatings around lipid droplets on their physical stability and in vitro digestibility by pancreatic lipase was studied. An electrostatic deposition method was used to form primary, secondary and tertiary emulsions containing lipid droplets coated by: 1°, β-lactoglobulin (β-Lg); 2°, β-Lg-alginate; 3°, β-Lg-alginate-chitosan. The influence of pH (3–7), calcium concentration (5 or 20?mM) and oil type (long vs. medium chain triglycerides) on their physical stability and lipid digestibility was examined. Biopolymer layers had little impact on lipid digestion at 5?mM calcium suggesting that they became detached from the droplet surfaces, but they slowed down digestion considerably at 20?mM calcium, suggesting the formation of a calcium alginate gel that restricted lipases access to emulsified lipids. This study has important implications for design of delivery systems to control lipid digestion and release.     

Superiority of nonlinear mapping in decoding multiple single-unit neuronal spike trains: a simulation study

One of the most important building blocks of the brain–machine interface (BMI) based on neuronal spike trains is the decoding algorithm, a computational method for the reconstruction of desired information from spike trains. Previous studies have reported that a simple linear filter is effective for this purpose and that no noteworthy gain is achieved from the use of nonlinear algorithms. In order to test this premise, we designed several decoding algorithms based on the linear filter, and two nonlinear mapping algorithms using multilayer perceptron (MLP) and support vector machine regression (SVR). Their performances were assessed using multiple neuronal spike trains generated by a biophysical neuron model and by a directional tuning model of the primary motor cortex. The performances of the nonlinear algorithms, in general, were superior. The advantages of using nonlinear algorithms were more profound for cases where false-positive/negative errors occurred in spike trains. When the MLPs were trained using trial-and-error, they often showed disappointing performance comparable to that of the linear filter. The nonlinear SVR showed the highest performance, and this may be due to the superiority of SVR in training and generalization.     

Patient oriented and robust automatic liver segmentation for pre-evaluation of liver transplantation

Identifying liver region from abdominal computed tomography-angiography (CTA) data sets is one of the essential steps in evaluation of transplantation donors prior to the hepatic surgery. However, due to gray level similarity of adjacent organs, injection of contrast media and partial volume effects; robust segmentation of the liver is a very difficult task. Moreover, high variations in liver margins, different image characteristics with different CT scanners and atypical liver shapes make the segmentation process even harder. In this paper, we propose a three stage (i.e. pre-processing, classification, post-processing); automatic liver segmentation algorithm that adapts its parameters according to each patient by learning the data set characteristics in parallel to segmentation process to address all the challenging aspects mentioned above. The efficiency in terms of the time requirement and the overall segmentation performance is achieved by introducing a novel modular classification system consisting of a K-Means based simple classification system and an MLP based complex one which are combined with a data-dependent and automated switching mechanism that decides to apply one of them. Proposed approach also makes the design of the overall classification system fully unsupervised that depends on the given CTA series only without requiring any given training set of CTA series. The segmentation results are evaluated by using area error rate and volume calculations and the success rate is calculated as 94.91% over a data set of diverse CTA series of 20 patients according to the evaluation of the expert radiologist. The results show that, the proposed algorithm gives better results especially for atypical liver shapes and low contrast studies where several algorithms fail.     

医院三层网络架构分析与设计

本文比较了两种全新的网络系统的构架,针对人民医院网络升级改造进行了网络架构的选型、网络设备的选型、网络升级改造的具体实施。通过这次网络升级改造,人民医院完成了从二层网络架构升级到三层网络架构,满足了医院现有的各个系统应用对网络环境的需要,同时提高了网络运行效率,增强了网络的安全性、可靠性和扩展性。     

心电门控技术在多层螺旋CT冠状动脉成像中的应用

在多层螺旋CT心脏及冠状动脉成像中,利用心电门控制技术在心脏运动最慢的时期采集图像数据,实线抑制心脏运动伪影的目的.心电门控制技术分为前瞻性心电门控和回顾性心电门控两各种,本文介绍了两种心电门控技术的原理、方法及与之相互的图像重建方法,并讨论各自的优缺点及临床应用.