农药残留检测生物传感器酶固定技术研究进展

酶生物传感器在农药残留检测方面具有传统检测方法不可比拟的优势,而酶的固定技术将直接影响酶生物传感器的性能.该文就酶的不同固定方法和使用的不同载体材料,对近二十年来农药残留检测生物传感器酶的固定技术的研究进展进行综述,并就不同固定方法,不同固定方法的特点和不同载体材料对生物传感器性能的影响作了简单介绍.     

碳纳米管修饰酶生物传感器的应用进展

很多酶生物传感器是利用氧化酶将底物氧化,同时产生过氧化氢,通过在电极表面检测过氧化氢的量来达到检测的目的。碳纳米管用于修饰电极,可降低化学物质氧化还原反应的过电位,改善生物分子氧化还原可逆性,达到提高检测的灵敏度和稳定性的目的。本文介绍了酶生物传感器及碳纳米管修饰酶生物传感器,并综述了近几年来碳纳米管修饰酶生物传感器的应用进展。     

酶传感器的应用

酶传感器是电化学生物传感器中研究最早、应用最广的一类传感器,也是近年来生物传感器研究的热点。简要介绍了酶传感器的发展历程,着重介绍酶传感器在食品工业、环境监测、生物医学、军事领域等方面的应用,并对酶传感器的发展进行了展望。     

Application of enzyme biosensors

酶传感器是电化学生物传感器中研究最早、应用最广的一类传感器,也是近年来生物传感器研究的热点.简要介绍了酶传感器的发展历程,着重介绍酶传感器在食品工业、环境监测、生物医学、军事领域等方面的应用,并对酶传感器的发展进行了展望.     

基于纳米材料的辣根过氧化物酶电化学传感器的构建

酶生物传感器具有高选择性是由于酶对底物高选择性和反应产物指示无干扰性.这为在大量常规分析中进行快速实时分析提供了可能.自从Clark等首次报道了可以将酶固定在电化学检测器表面制成酶电极以来,电化学生物传感器得到了迅速地发展,电化学传感器被认为是21世纪最具有前途的研究领域之一.     

氧化还原模拟酶的研究现状

生物酶具有高效、专一的催化特性,但酶对热敏感,价格昂贵,稳定性差等缺点妨碍了它的开发利用。为了克服这些缺点,模拟酶的研究已成为重要的发展方向。在生物传感器方面,以一种稳定的仿酶催化剂代替天然酶也是很有意义的。Rechnitz 等首次报道了一种高稳定性的模拟酶传感器,模拟酶寿命比天然酶长得多,而且不需要辅助因子。Tatsuma 等报道了一种以血红素肽为过氧化物酶模型化台物曲过氧化氢传感器,在温和电位150mV vs Ag/AgCl 条件下,不需电子介体或促进剂,响应时间少于1min,对 H_2O_2检测下限可达10~(-6)mol/L。Tatsuma 等最近还报道了一种以血红素肽为过氧化物酶模型化合物测定咪唑衍生物的生物传感器。美国 Abbort 实验室正在研究模拟酶传感器用于血液中药物和激素的测定。可以预言,随着模拟酶研究的深入,模拟酶传感器将会得到一个更大的发展。为此,我们对模拟酶的基本观点和几个实例做一简单介绍。     

介质电流型电极的作用机制探讨

生物传感器以其生物活性分子识别作为基础,有严格的专一性、较高的灵敏度,且操作方便简单,在生物过程控制和医疗临床上有广泛的应用前景,因此,新型生物传感器的开发研究日益受到重视。生物传感器由于其生物活性成分的不同(如酶、细胞、细胞器、免疫物质、受体等)和传感方式的不同(如压电型、电流型、电压型、FET 型、光敏型、热敏型等)分成许多类型,但现在研究得最多,应用范围最广的是电流型酶生物传感器。自从1962年 Clark和 Lyons 第一次提出“酶电极”概念以来,这种生物传感器发展迅速,已经从传统的第一代二次传感型电极,经过第二代一次传感型电极(1984,Cass et al),发展到第三代直接传感电极三代传感器的作用原理图见图1.     

检测神经性毒剂生物传感器的研究

阐述了通过微结构设计实现电化学技术与生物酶技术的有机结合,制造出对神经性毒剂敏感的生物传感器,分析了传感器的工艺制造过程,解决了酶的选择、酶的提纯、酶的固定化、底液、电极制作等关键技术。讨论了传感器的性能特点,稳定工作时间大于8h,传感器响应时间小于10min,零点漂移小于±2VDC。     

淀粉双酶传感器的研制

报导了一种测定淀粉的酶生物传感器法，它具有检测速度快、灵敏度高、操作简便、且样品需要量少等优点。酶生物传感器是由固定化的ＧＯＤ、ＧＡ酶膜和氧电极组成，测试的最佳条件为温度３０℃，ｐＨ＝４．４，０．２ｍｏｌ／Ｌ醋酸缓冲液，响应时间２ｍｉｎ。该法的精密度、准确度均良好，线性范围０．０５％～０．８％。     

酶生物传感器的研究进展

介绍了酶生物传感器的原理、特性及其分类;阐述了第一代传感器获得电信号的途径;引入电子传递介体后的第二代传感器的灵敏性和准确性得到提高;实现第三代传感器的酶在电极上固定的方法和材料.对基于直接电子传递的第三代生物传感器的研究现状进行了评述.最后,展望了生物传感器的发展方向.     

Preparation of ZnO nanorods by microemulsion synthesis and their application as a CO gas sensor

Zinc oxide nanorods with different surface area were synthesized by surfactant assisted microemulsion method. The alkyl chain length of surfactant would affect aspect ratio of ZnO nanorods. ZnO nanorods synthesized by ethyl benzene acid sodium salt (EBS), which is surfactant with short alkyl chain length, show higher aspect ratio than ones by dodecyl benzene sulfonic acid sodium salt (DBS). These nanorods had diameters in the range of 80–300 nm and length of up to several microns. The Brunauer–Emmett–Teller (BET) surface area of the ZnO nanorods was strongly affected by the morphology of the nanorods. The BET surface area of the nanorods synthesized with EBS was higher than the surface area of the nanorods synthesized with DBS (20.2 and 14.1 m²/g for EBS and DBS, respectively). The response of ZnO nanorods to CO in air was strongly affected by surface area, defects and oxygen vacancies. The results demonstrate that the microemulsion synthesis is an easy and useful method to synthesize ZnO nanorods with large aspect ratio, which may enhance their gas sensing properties.     

The medium matters: Mining the long-promised merit of group interaction in creative idea generation tasks in a meta-analysis of the electronic group brainstorming literature

This meta-analysis examines the influence of electronic communication media on group idea generation tasks. Data from the following three areas of the brainstorming literature are synthesized to assess differences across performance variables and group member satisfaction: (1) electronic brainstorming (EBS) groups versus traditional face-to-face (FTF) interacting groups, (2) EBS groups versus nominal groups, and (3) EBS versus electronic nominal (e-nominal) groups. The results of this integration show that EBS groups are more productive and more satisfied with the interaction process than FTF groups. Additionally, large EBS groups outperformed nominal groups, whereas small nominal groups outperformed EBS groups. These findings have important implications for electronic collaboration and teamwork in both academic and organizational settings, especially given the recent proliferation of virtual teamwork.     

Erosion band signatures for spatial extraction of features

We introduce Erosion Band Signatures (EBS), which are a codification of the spatial coherence of features extracted from a region. This coherence is often lost in traditional global and local feature extraction methods, thereby diminishing a feature’s discriminative strength. The erosion band signature is generated through iterative erosions of the region of interest, forming what we call erosion bands. Features are then extracted from each band and accumulated in a specific order to form the EB signature, which preserves spatial information of the features. To demonstrate the versatility of EBS, we have implemented the method in two very different applications: polyp detection and region-based head tracking. In polyp detection, EBS provides an effective way to characterize spatial differences between the perimeter and core of a polyp candidate, and improves a state-of-the-art computer-aided detection method with an improved 27.6% reduction of false positives. We also apply EBS analysis to region-based tracking yielding a very clear improvement in both robustness and accuracy.     

ARCHITECT: A layered framework for classifying technologies of event-based systems

In the past decade, event-based systems (EBS) have received increasing attention from various communities. Central to these systems is the notion of event, which is often generally considered as “a happening of interest”. An EBS encompasses a large range of functionalities on various technological levels (e.g., language, execution, or communication). Existing approaches vary in the scope of implemented functionality and underlying technical concepts. For this reason, comparing EBS solutions is a challenging task. Furthermore, the lack of a unified view on EBS poses challenges to system architects in choosing and combining technologies for building event-based systems.     

Topology preservation evaluation of compact-support radial basis functions for image registration

Many Radial Basis Function (RBF)-based transformations are used to model the deformations in image registration, and they have different topology preservation properties. This paper compares analytically and experimentally the topology preservation performance of compact-support thin-plate Spline (CSTPS), locally constrained cosine (Cos), Wendland, Gaussian, Buhmann and Wu functions in landmark-based image registration. In addition, the topology preservation characteristics of thin-plate Spline (TPS) and elastic body Spline (EBS)-based transformations are compared for global-support deformations. The comparative results show that, for local deformation CSTPS and Buhmann preserve topology better than others. The Cos and Gaussian functions could easily produce topology violations for relatively dense-landmark matching. For global-support transformations, CSTPS, Wendland ψ_3,1, Buhmann, Wu and TPS outperformed others because they preserve topology better. The Cos, Gaussian and EBS functions perform poorly because folds and tears of the deformation surface occur easily. With very large support, CSTPS produces similar results as TPS, and Wendland ψ_3,1 has similar performance with Wu functions. Also, Cos and Gaussian performed similarly in this case. In the experiments, these theoretical results are evaluated extensively using transformations on random point sets, artificial images, and medical images.     

Heuristic Contention-Free Broadcast in Heterogeneous Networks of Workstations with Multiple Send and Receive Speeds

This paper presents three efficient contention-free algorithms for broadcasting on heterogeneous networks of workstations (HNOW). In an HNOW, many different speed types of workstations can have distinct send and receive overhead. Previous research has shown that finding an optimal routing scheme in an HNOW is not easy [2,12], because properly arranging all workstations in the scheduling tree is difficult. Therefore, this investigation focuses mainly on enhancing the performance of an HNOW by properly arranging fastest nodes into the internal nodes of upper levels in the scheduling tree. Fastest node first is fundamental in designing an efficient algorithm. This paper presents three schemes called EBS, VBBS, and VBBSWF. All of these three schemes can be executed in O(n log(n)) time, where n is the number of workstations. They are all contention-free when broadcasting in an HNOW. Based on the simulation result, the proposed schemes outperform the broadcast with minimal steps [13] and the scheduling tree [22] generated by dynamic programing in an HNOW.     

Word的“邮件合并”功能在期刊管理中的应用

Word是办公自动化中最常用的软件之一,其中有些功能平时不容易注意到,但通过结合实践的应用开发,可以在期刊管理流程中发挥重要的作用。本文通过对Word中"邮件合并"功能的开发,解决了期刊管理流程中的实际问题,不仅能提高实际工作的效率,而且对办公人员结合工作需求自行开发软件应用,具有举一反三的启发性作用。     

基于FPGA的VXI总线接口电路设计

研制开发VXI总线的模块化仪器，其关键是接口电路设计。VXI接口的集成化、单片化可以大大简化VXI模块开发的过程。FPGA具有集成度高、可靠性好、速度快、价格低、编程方便、设计灵活等特点，很适合VXI接口设计。在此采用FPGA来设计VXI总线接口电路，并详细讨论接口中几个主要功能模块的设计和实现。     

A methodology and notation for compiler front end design

A methodology and associated notation for designing compiler front ends, and in particular the interface between the parser and the semantic routines, is described. The methodology leads to a clean, easy to understand, documentable design. The notation is similar to an attribute grammar, but its purpose is to document the first pass of a specific compiler, rather than to describe the semantics of a language. It is designed to be accessible to non-specialists, easy to learn, and natural. It can be used with or without software support. The notation was used during the development of a large compiler, and to assist in the transfer of the compiler to the group that will maintain it. Experience with the notation indicates that it meets its goals.     

基于体系结构的软件过程Petri网模型

传统的软件过程模型存在开发效率不高,可移植性差,重用粒度小等缺点.Petri网由于自身的特点,可用于形式化描述软件过程,学术界已有部分研究.但已经发表的研究多是基于高级Petri的扩展,十分复杂和繁琐,难以应用到实际软件项目中.综合利用软件过程理论、软件体系结构理论以及Petri网理论,提出了基于体系结构的软件过程Petri网模型(ABSPN),并证明了ABSPN模型具有过程正确性、强连通性、活性和有界性.实践证明,采用ABSPN模型进行软件开发,可以使软件结构清晰,易于理解,可移植性强,重用粒度大.