基于仿双酶原位产生共反应试剂而构建的超灵敏电致化学发光免疫传感器

该实验基于仿双酶原位产生共反应试剂放大信号构建了用于检测甲胎蛋白(AFP)肿瘤标志物的S2O82-电致化学发光(ECL)免疫传感器。通过L-半胱氨酸(L-cys)与空心铂钯纳米链(HPtPd)的层层自组装,提高L-cys与HPtPd的固载量。再结合二者本身对S2O82-发光的催化性,极大地增强了发光信号。同时,作为封闭剂的葡萄糖氧化酶(GOD)可以催化底物葡萄糖产生H2O2,而HPtPd可以作为H2O2的模拟酶催化其生成O2。O2作为S2O82-电致化学发光的共反应试剂可以极大地提高传感器的灵敏度。根据以上信号放大因素,设计夹心结构的免疫传感器,其线性范围为0.0001到100ng/mL,检出限也达到了33fg/mL。     

基于辣根过氧化物酶及纳米钯的双重放大策略用于构建电化学凝血酶适体传感器

基于辣根过氧化物酶(HRP)及纳米钯(NanoPd)对过氧化氢(H2O2)的双重催化作用放大铁氰化镍(NiHCF)的电化学氧化还原信号构建了一种新型的电化学适体传感器。采用生物兼容性好的壳聚糖(CS)分散石墨烯-碳纳米管复合物(CS-Gra-CNTs)可以大大提高其导电性和比表面积,吸附更多电活性好、化学性质稳定的电子媒介体NiHCF。固定NanoPd并吸附凝血酶适体(TBA),用HRP封闭非特异性吸附位点后,在含有一定浓度的H2O2的磷酸缓冲溶液(PBS)中可用于高灵敏检测凝血酶(TB)。在最优条件下,采用循环伏安法考察该传感器的电化学特性,研究表明,峰电流值与TB浓度在1.0×10-5～3.0×10-2mol/L成线性关系,检出下限为3.0×10-6mol/L。并且,该传感器制备简单、操作简便、稳定性好、寿命长、灵敏度高、特异性强。     

普鲁士蓝/PDDA–石墨烯复合膜修饰电极的制备及应用于过氧化氢无酶传感器

制备了一种基于普鲁士蓝/PDDA-石墨烯复合膜的新型无酶电化学传感器,可以用于过氧化氢的灵敏检测。以聚二烯丙基二甲基氯化铵(PDDA)作为分散剂和功能化试剂制备了PDDA功能化的石墨烯(PDDA-G),然后将普鲁士蓝(PB)电沉积到PDDA-G修饰的玻碳电极表面,制备了PB/PDDA-G/GCE。实验发现,在工作电位为-0.3 V时,PB/PDDA-G/GCE作为传感器对H2O2的电化学还原有很好的催化能力,响应时间小于5 s,这主要是缘于PDDA-G和PB的协同作用。在3.0μmol/L~2 061μmol/L的范围内,H2O2的还原电流与其浓度呈现良好的线性关系,检出限为1.0μmol/L(S/N=3)。该修饰电极有望用于实际样品中H2O2的快速检测。     

纳米Pt/聚吡咯/HRP酶共固定微电极传感器及对血清中H2O2的快速测定

将聚吡咯(PPy)和辣根过氧化物酶(HRP)以电聚合的方式沉积在微Pt电极(φ=10μm)上,再以电化学沉积法将纳米Pt颗粒沉积在电极表面,由此制备出纳米Pt/HRP-PPy共固定微电极传感器(Pt/HRP-PPy-nano Pt CME),研究了其电化学行为。在除O2的磷酸盐缓冲液(PBS)中,该电极加速了H2O2还原反应,而沉积在PPy上的纳米Pt显著催化了该反应。以计时电流法定量分析H2O2,在30℃的0.02mol/LpH=7.0PBS中检测H2O2,在0.001～0.3mmol/L浓度范围呈现线性响应,相关系数为0.9972,检测下限达0.3μmol·L-1(S/N=3)。该传感器对H2O2电流响应灵敏度高(0.42mA.cm-2·mmol·L-1)、迅速(7.3s)、稳定性好。此传感器表现出Michaelis-Menten行为,KaMpp为0.033mmol·L-1。较小的KaMpp值表明固定在微Pt电极表面的纳米Pt/HRP对H2O2具有较高亲和性。检测了实际人血清样品中H2O2,结果和对照方法一致,本电极可用作痕量H2O2生医传感器。     

基于石墨烯-海藻酸钠复合材料的辣根过氧化物酶传感器研究

构建了一种以海藻酸钠-石墨烯(SA-GR)为基底的新型过氧化氢电化学酶传感器。利用滴涂法将生物相容性良好的海藻酸钠-石墨烯复合物固定在玻碳电极表面,再通过酰胺键将HRP连接在SA-GR复合膜上,从而制备出了性能良好的过氧化氢电化学酶传感器。该传感器重现性好、灵敏度较高,并且响应速度快(3 s),米氏常数较低(Km=0.663),对H2O2检测的线性范围为1.0×10-4～1.2×10-3mol/L,检测下限为5.7×10-6mol/L。     

基于HRP催化过硫酸盐阴极电致化学发光的非标记型免疫传感器

基于酶催化阴极电致化学发光（ECL）构建灵敏的免疫传感器用于肿瘤标志物检测。利用过氧化氢酶（HRP）催化H2O2底物反应产生大量溶解氧,催化增强S2O82-的阴极ECL信号,构建非标记型免疫传感器。当抗原蛋白在电极表面与抗体形成免疫复合物时,屏蔽了检测液中底物与电极表面固载酶之间的接触并阻碍了电子传递,使ECL信号强度随抗原浓度增加而减小,建立ECL信号与待测物浓度之间的线性依赖关系,实现对血清中肿瘤标志物CEA的快速灵敏检测,检测限达1.04 ng/mL。     

纳米银/石墨烯电化学传感器的制备及应用研究

以硝酸银和氧化石墨为原料,采用硼氢化钠还原法制备了纳米银/石墨烯纳米复合材料(Nano-Ag/ERGO),并采用紫外-可见吸收光谱法、X-射线粉末衍射法及红外光谱法进行表征.采用滴涂法制备了纳米银/石墨烯复合纳米材料修饰的玻碳电极(Nano-Ag/ERGO/GCE).研究了过氧化氢(H2O2)在制备的修饰电极上的电化学行为.结果表明:采用一步还原法制备石墨烯支持银纳米粒子,具有制备方法简单且纳米粒子粒径可控等优点,对H2O2的电还原具有极强的催化活性.研究成果在实际样品的H2O2快速检测中具有潜在的应用价值.     

基于电化学还原氧化石墨烯的电化学DNA生物传感器

使用还原氧化石墨烯(rGO)制备一种简单、快速和可重复方法构建DNA生物传感器。将带负电的氧化石墨烯(GO)与半胱氨酸上带正电的氨基基团通过静电作用相互吸附,用线性扫描伏安法(LSV)电化学还原电极表面吸附的GO。将二茂铁标记的DNA(Fc-DNA)探针固定到r GO表面,成功构建DNA传感器。传感器的制备过程使用循环伏安法和拉曼光谱表征。通过杂化前后DNA传感器所展现出方波信号峰电流的差异,实现对目标DNA的定量检测。实验结果表明:目标DNA浓度在1. 0×10~(-13)～1. 0×10~(-6)mol/L范围内,峰电流变化与目标DNA浓度呈线性关系,线性相关系数为0. 981,检测限是2. 0×10~(-13)mol/L (S/N=3)。     

基于Pt/PEDOT/PSS-Graphene复合材料的H2O2生物传感器

本文以聚苯乙烯磺酸钠（PSS）功能化的石墨烯为载体原位聚合PEDOT制备PEDOT/PSS-Graphene复合材料,然后将该复合材料修饰于玻碳电极（GCE）表面制得PEDOT/PSS-Graphene/GCE电极,并在此基础上电沉积负载Pt纳米颗粒构建了一种新的无酶H2O2生物传感器。利用扫描电子显微镜（SEM）对制得的修饰电极进行表征,同时通过循环伏安法和计时电流法研究了该传感器对H2O2的响应性能。结果表明,所制备的传感器对H2O2检测有极快的响应速度（1.5 s）,在11.57 μmol/L～3.60 mmol/L H2O2浓度范围内成线性相关,检出限为9.27 μmol/L,且具有良好的重现性、稳定性和选择性。     

基于铂纳米颗粒修饰碳纳米管Nafion膜电极的葡萄糖传感器

将分散在Nafion溶液中的多壁碳纳米管(MWNT)修饰玻碳电极(GCE),再在该膜上电沉积一层铂纳米粒子,制成铂纳米颗粒修饰的碳纳米管Nafion膜电极(Nafion-MWNT-Pt/GCE),并吸附固定葡萄糖氧化酶(GOD),构建电流型葡萄糖生物传感器。考察了Nafion-MWNT-Pt/GCE的电化学特性,发现沉积铂纳米粒子后,Fe(CN)6-3/-4电对在Nafion-MWNT-Pt/GCE上的氧化峰和还原蜂之间的电势差(ΔE)为179mV,小于未修饰铂纳米粒子的碳纳米管Nafion膜电极的ΔE(190mV),表明碳纳米管上电沉积的铂纳米粒子可加速电极的电子传递,电化学反应具有良好的可逆性。此外,铂纳米粒子尚具有良好的催化H2O2氧化的特性,H2O2在Nafion-MWNT-Pt/GCE上的计时电流响应明显增大。基于Nafion-MWNT-Pt/GCE的葡萄糖生物传感器显示了良好的传感性能,其检测线性范围为2.1×10-5～7.6×10-3mol/L,检测下限为1.0×10-6mol/L。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.