Single-cell assays

This review presents an overview of literature that describes the applications of microfluidics to assay individual cells. We quantify the content of an individual mammalian cell, so that we can understand what criteria a single-cell assay must satisfy to be successful. We put in context the justification for single-cell assays and identify the characteristics that are relevant to single-cell assays. We review the literature from the past 24 months that describe the methods that use microfabrication-conventional or otherwise-and microfluidics in particular to study individual cells, and we present our views on how an increasing emphasis on three-dimensional cell culture and the demonstration of the first chemically defined cell might impact single-cell assays.     

基于Access数据库的可视化套打系统设计

随着公司业务的扩展入职人员不断增多,原有通过逐条修改Excel表单数据打印工资条的方式已经不能满足公司人事管理系统的需求。文章通过Access数据库设计一套工资系统套打程序,实现可视化及批量修改数据,解决了原有工资系统修改、打印过程复杂、效率低的问题。     

Sequential detection based on simple quantization

Some generalizations of the classical ruin problem in probability theory are investigated and are applied to analyze the sequential dead-zone limiter detector and the sequential four-level sign detector. The performances of these detectors are then compared to that of the sequential sign detector in terms of the relative efficiency (RE) and the asymptotic relative efficiency (ARE).     

基于MATLAB的视频马赛克检测算法

马赛克是多年来困扰广电工作者的问题,目前我国大多数无线覆盖台站仍沿用人工监看的方法来监测电视视频的马赛克现象,这一做法显然已不能满足愈来愈高的安全播出要求。文章提出一种基于MATLAB的视频马赛克检测算法,在对视频图像进行canny边缘检测的基础上,通过模板匹配来实现马赛克检测,仿真实验的结果验证了本算法的有效性和实时性。     

Targeted cell detection based on microchannel gating

Currently, microbiological techniques such as culture enrichment and various plating techniques are used for detection of pathogens. These expensive and time consuming methods can take several days. Described below is the design, fabrication, and testing of a rapid and inexpensive sensor, involving the use of microelectrodes in a microchannel, which can be used to detect single bacterial cells electrically (label-free format) in real time. As a proof of principle, we have successfully demonstrated real-time detection of target yeast cells by measuring instantaneous changes in ionic impedance. We have also demonstrated the selectivity of our sensors in responding to target cells while remaining irresponsive to nontarget cells. Using this technique, it can be possible to multiplex an array of these sensors onto a chip and probe a complex mixture for various types of bacterial cells.     

基于前景检测的视差优化算法

目前立体匹配算法分两类,传统的匹配算法通过计算两幅图的像素点相似程度,采用的是一种局部优先的方法。而当前的策略主要将问题转化为求解能量方程,进而对全局空间进行优化,提高匹配精度,获得更好的视差图。但是在实际应用过程中,由于光学失真和噪声,平滑表面的镜面反射,投影缩减,透视失真,低纹理和重复纹理等影响,导致误匹配或者找不到匹配点,从而得不到有效视差。然而在特定的场合,可以利用有限的有效视差,基于前景检测以及最小二乘法,优化得到较为完整的前景视差图。     

3D打印技术对物流企业仓储影响研究 ——以UPS公司为例

随着3D打印技术的快速发展,传统物流企业管理模式必然会受到影响与冲击。本文聚焦快递类物流企业仓储模块,基于3D打印技术、新兴技术管理理论,运用案例研究法对UPS公司单案例做深入探索分析,深入剖析3D打印技术对UPS公司仓储过程的运作流程、职能调整、仓储布局、仓储成本等诸多方面的影响,进而启示其他快递类物流企业应了解3D打印技术其仓储模块的全面影响。     

[2015年第2期] 基于局部优化的社区发现方法研究现状

文章介绍了社交网络背景下社区的定义以及主要的社区划分评价指标;根据不同的 局部优化策略, 将基于局部优化的社区发现方法分为局部扩展优化、派系过滤、标签传播、局 部边聚类优化 4 类进行对比分析。 基于局部扩展优化的社区发现方法能有效揭示局部社区 结构,能提取有意义的局部聚类信息,如层次性和重叠性,对于大规模且动态变化的在线社交 网络, 在线社区的形成由于依赖局部的交互而表现出更强自治能力, 因此局部扩展优化社区 发现方法为在线社区挖掘提供了一个非常有效的途径。 派系过滤方法由于其严格的社区结 构定义能有效发现有结合力的局部社区以及高度重叠社区。 标签传播算法在计算复杂度上 有着明显的优势, 适用于大规模社交网络中的社区挖掘。 而基于局部边聚类使社区发现方法 能很好地处理网络中的重叠节点。 最后, 文章对社区发现存在的一些问题和未来的研究做出 展望： 快速是社区发现方法的一个基本要求和发展趋势; 精确性是社区发现技术的一个重要 研究方向; 综合的分析系统有助于为众多的社区发现技术和方法提供综合、客观的分析和评 价;社交网络的动态演化特征给社区发现提出了更高要求和更多挑战。     

基于ＥＭ ＰＣＡ和级联分类器的人脸检测

为了提高人脸检测的速度及鲁棒性,提出了一种基于级联分类器和期望最大、主成分分析（ＥＭ ＰＣＡ）的人脸检测方法．该方法在训练阶段利用不同分辨率的训练样本来训练２个ｆｉｓｈｅｒ线性分类器,再利用ＥＭ ＰＣＡ提取特征来训练非线性支持向量机（ＳＶＭ）;在检测阶段,首先通过２个ｆｉｓｈｅｒ线性分类器快速过滤掉大量的背景区域,再利用非线性支持向量机对余下的候选区域进行进一步验证,以确认是否为人脸．实验结果证明了该方法的有效性和正确性．     

Amplification of urea detection based on pH-sensitive liposomes

BackgroundThis study aimed to develop an amplification method of urea detection based on pH-sensitive liposomes.ResultsThe urease covalently immobilized on the magnetic particles and the pH-sensitive liposomes encapsulating ferricyanide were added to the cyclic-voltammeter cell solution where urea was distributed. The conversion of urea into carbonic acid seemed to induce a pH decrease that caused a reduction in the electrostatic repulsion between the headgroups of weakly acidic 1,2-dipalmitoyl-sn-glycero-3-succinate. The reduction induced the liposomes to release potassium ferricyanide that was encapsulated inside. The effects of urea concentration and pH value were investigated. A specific concentration (0.5 mg/mL) of the urea solution was set to observe the response. The activity of urease was reversible with respect to the pH change between 7 and 5. The sensitivity of this detection was almost identical to the comparable techniques such as an enzyme-linked immunosorbent assay and a field-effect transistor.ConclusionsIn summary, the methodology developed in this study was feasible as a portable, rapid, and sensitive method.How to cite: Kang MK, Park J-W. Amplification of urea detection based on pH-sensitive liposomes. Electron J Biotechnol 2021;51. https://doi.org/10.1016/j.ejbt.2021.04.005