Multifunctional encoded self-assembling protein nanofibrils as platform for high-throughput and multiplexed detection of biomolecules

A one-dimensional nanofibrillar array formed by the co-assembly of native and biotin-functionalized beta-amyloid (Aβ) peptide was developed for biomolecule sensing. With the presence of biotin moiety, a variety of biomolecular probes can be conjugated onto the nanofibrils, thus converting the protein assembly into a miniature biosensor. In this work, DNA probes were immobilized onto the fibril for the detection of cDNA sequences. The as-developed "DNA-nanoarray" achieved a detection limit at subattomole level (183 fM in 10 μL). This highly sensitive, yet simple, assay requires a trace amount of sample consumption (<10 μL) and is pretreatment-free. In addition, we reported the preparation of alternate-segmented amyloid nanofibrils with multifunctionality. The fibrils hereby serve as an encoded template that can be visualized with various fluorescence labeling dyes for barcode recognition purpose, and, hence, multiplex detection of biomolecules was achieved. Regarding that each protein nanofibril represents a single detection platform, a large number of single fibrils simultaneously are monitored with the dual-color TIRFM in a high-throughput manner.     

Development of rapid oral bacteria detection apparatus based on dielectrophoretic impedance measurement method

In this study, a bacteria detection apparatus based on dielectrophoretic impedance measurement (DEPIM) method was demonstrated for rapid evaluation of oral hygiene. The authors integrated a micro electrode chip on which bacteria were captured by dielectrophoresis (DEP), an AC voltage source to induce DEP force, and an impedance measurement circuit to a portable instrument that enables rapid and automated oral bacterial inspection in hospitals and clinics. Special considerations have been made on effects of high electrical conductivity of oral samples on DEP force and DEPIM results. It was shown experimentally and theoretically that using a higher electric field frequency for the DEP bacteria trap and the impedance measurement could realise DEPIM application to bacteria inspection from oral samples with higher conductivity. Based on these investigations, the authors optimised the frequency condition of the DEPIM suitable for inspecting an oral sample along with the design and development of a portable DEPIM apparatus for on-site inspection of oral bacteria. Under the optimised frequency condition, DEPIM results were in good agreement with the conventional culture method showing significant applicability of the DEPIM apparatus for practical rapid oral bacteria inspection.     

Particles for multiplexed analysis in solution: detection and identification of striped metallic particles using optical microscopy

In this report, we present data demonstrating that cylindrical metallic particles, with various submicrometer striping patterns, may be readily distinguished in an optical microscope. Accurate particle identification is discussed relative to synthesis reproducibility and the limitations of optical microscopes. Results from a library of these particles, of which over 100 different striping patterns have been produced, are presented. For these particles, made with Au and Ag stripes, more than 70 patterns may be identified with greater than 90% accuracy. The ability to chemically modify the surface of these particles, making them useful for bioanalytical measurements, is also demonstrated. Finally, we discuss improvements in our manufacturing and identification processes that will lead to both larger numbers of striping patterns and improved identification accuracy.     

基于电液复合控制系统功能的浅水测试技术研究

为掌握水下液控系统浅水测试技术,以常用的电液复合控制系统为基础展开研究。分析电液复合控制系统的组成、工作原理和功能要求,结合现有标准要求和国内外测试现状,提出浅水测试场需配置的测试系统及其连接方式,明确测试内容,编制测试流程,并阐述具体的测试方法。研究结果可为国内浅水测试场建设及水下液控系统浅水测试作业提供参考。     

基于环形激光的深孔内膛形貌检测系统研究

提出了一种基于环形激光的深孔内膛检测系统,该系统主要由环形激光发生器、反射锥镜、CCD相机以及驱动装置等组成。通过对环形激光器投射在被测身管内膛上的环形光斑进行成像和分析计算,可对身管内膛的一个截面形廓进行检测,并在驱动装置的驱动下,实现对深孔内膛形貌的三维检测。     

Intermolecular and intramolecular quencher based quantum dot nanoprobes for multiplexed detection of endonuclease activity and inhibition

DNA cleavage by endonucleases plays an important role in many biological events such as DNA replication, recombination, and repair and is used as a powerful tool in medicinal chemistry. However, conventional methods for assaying endonuclease activity and inhibition by gel electrophoresis and chromatography techniques are time-consuming, laborious, not sensitive, or costly. Herein, we combine the high specificity of DNA cleavage reactions with the benefits of quantum dots (QDs) and ultrahigh quenching abilities of inter- and intramolecular quenchers to develop highly sensitive and specific nanoprobes for multiplexed detection of endonucleases. The nanoprobe was prepared by conjugating two sets of DNA substrates carrying quenchers onto the surface of aminated QDs through direct assembly and DNA hybridization. With this new design, the background fluorescence was significantly suppressed by introducing inter- and intramolecular quenchers. When these nanoprobes are exposed to the targeted endonucleases, specific DNA cleavages occur and pieces of DNA fragments are released from the QD surface along with the quenchers, resulting in fluorescence recovery. The endonuclease activity was quantified by monitoring the change in the fluorescence intensity. The detection was accomplished with a single excitation light. Multiplexed detection was demonstrated by simultaneously assaying EcoRI and BamHI (as model analytes) using two different emissions of QDs. The limits of detection were 4.0 × 10(-4) U/mL for EcoRI and 8.0 × 10(-4) U/mL for BamHI, which were at least 100 times more sensitive than traditional gel electrophoresis and chromatography assays. Moreover, the potential application of the proposed method for screening endonuclease inhibitors has also been demonstrated. The assay protocol presented here proved to be simple, sensitive, effective, and easy to carry out.     

Sensitive DNA hybridization detection based on the deposition of gold nanoparticle on lyophobic surface

An assay for the detection of DNA hybridization was developed using Ellipsometric Scanner (ES) as a detection method. The different deposition trends of Au nanoparticle on glutaraldehyde-covered Si substrate caused by the different electrostatic properties of Au nanoparticles after interaction with ssDNA and dsDNA respectively can be observed by measuring the ellipsometric parameter y. At the same time, the average height of the y with respect to the cross-sectional contour c can be described by y = 0.0920 + 2.43c in the range of 5.4 to 27 nM (r = 0.943, c is target concentration, the unit is μM). This assay using ES imaging could successfully detect the total amounts of the target as low as 5.4 fmol. The proposed assay system has the advantage of allowing label-free detection, high sensitivity, and operational simplicity.     

基于风电场SCADA系统的云平台设计

为充分利用风电场集控中心采集爆炸式增长的海量数据,解决风电场SCADA系统数据存储和处理能力不足的问题,设计基于SCADA系统的云计算平台,实现数据的高效分布式存储以及处理。传统LS-SVM适用于小样本数据,对风电场海量数据的处理比较乏力,针对此问题,采用MapReduce云计算平台实现算法并行化,并用遗传算法对其进行参数寻优。最后利用某实际风电场SCADA系统的历史数据,实现短期风功率预测功能。在数据不断增加的情况下,采用MapReduce云计算平台实现LS-SVM算法并行化训练比单机LS-SVM训练缩短的时间十分显著,可增强SCADA系统的实时性;当数据增加到1.2 GB时,时间缩短一半,而准确度相差0.1%。     

基于车载平台的人工辅助型照度检测车设计

发光二极管(light emitting diode,LED)路灯较传统路灯降低功耗的同时照度随之降低,若LED路灯质量不达标,则会进一步降低路面照度。为此研发基于车载平台的人工辅助型照度检测车设计,该系统检测流程根据国标制定,能实时准确采集路面水平面照度、移动距离,结合高性能中央处理器,具备传感数据采集、处理、存储、远程传输等功能。为实现直观监测,开发智能手机应用程序(application,APP)平台,远程无线监测传感数据。结果表明车载平台相比于传统人工检测节省66.67%时间,同时用平均照度相对误差低于1.81%,提高检测效率。     

基于PMAC的开放式数控系统实验平台的研究与开发

本文介绍了基于PMAC和IPC的开放式数控系统的硬件结构和软件机理 ,并介绍了用VivsualC 6 0开发人机界面的关键技术。     

基于PC平台的图像导引头操控测试系统设计

在导引头研发过程中测试有着至关重要的作用,测试系统一方面模拟弹上计算机与导引头进行功能验证,另一方面要对导引头进行设计指标测试。该文分析图像导引头的工作原理,提出一种基于PC平台的图像导引头操控测试系统设计方法。通过分析测试需求,建立图像导引头综合测试理论模型,包括详细的硬件设计和软件设计。根据理论模型搭建一套图像导引头操控测试系统实物,并对图像导引头进行操控测试,该测试系统覆盖图像导引头的功能指标测试和部分性能指标测试。试验结果表明:该测试系统具有可行性、全面性和通用性。     

LabVIEW平台的平面螺纹测量系统研制

基于极径变化,建立了平面螺纹螺旋线误差测量与评价模型,基于LabVIEW平台,研制了一套高准确度动态测量盘丝平面螺纹测量系统.本系统采用高准确度线性光栅及圆光栅系统测量平面螺纹的极径和极角,采用PLC系统控制伺服电机来带动精密气浮主轴旋转,采用CCD激光位移传感器配合线性光栅在测量前对平面螺纹进行调平调心,以提高测量准确度.与三坐标测量机(CMM)测量结果比对表明,本系统已达到预期设计要求,可在计量部门和企业推广使用.     

基于Android系统3G技术实验平台设计

本文介绍了嵌入式3G技术实验平台设计与实现方法,该平台基于Android系统,用程序实现了3G通信中的部分关键技术,可对其进行技术实验操作,并且可方便移植到使用Android系统的手机中,该平台有助于学生对3G通信技术的学习和理解。     

基于LabVIEW平台的信号实时采集与处理系统

基于Lab VIEW平台的信号实时采集与处理系统,相对于传统的基于Visual C++或Vx Works的系统,具有软件开发和修改快捷、可快速实现数据可视化、与通用平台或设备接口方便等优点,使科研人员能够将主要精力集中于实验而非编程。介绍了一种基于Lab VIEW平台的信号实时采集与处理系统。首先介绍了该系统的硬件组成和软件设计方法,之后详细介绍了将不同厂商的硬件板卡集成到Lab VIEW平台上,并由Lab VIEW统一控制的方法——生成动态链接库。该系统已成功应用于某型水声装备的效能评估试验中。     

Sensitive and rapid screening of T4 polynucleotide kinase activity and inhibition based on coupled exonuclease reaction and graphene oxide platform

Phosphorylation of DNA with 5'-hydroxyl termini plays a critical role in a majority of normal cellular events, including DNA recombination, DNA replication, and repair of DNA during strand interruption. Determination of nucleotide kinase activity and inhibition is under intense development due to its importance in regulating nucleic acid metabolism. Here, by using T4 polynucleotide kinase (PNK) as a model, which plays an essential role in cellular nucleic acid metabolism, particularly in the cellular responses to DNA damage, we describe a strategy for simply and accurately determining nucleotide kinase activity and inhibition by means of a coupled λ exonuclease cleavage reaction and graphene oxide (GO) based platform. The dye attached dsDNA preserves most of the fluorescence when mixed with GO. While dsDNA is phosphorylated by PNK and then immediately cleaved by λ exonuclease, fluorescence is greatly quenched. Because of the super quenching ability and the high specific surface area of GO, the as-proposed platform presents an excellent performance with wide linear range and low detection limit in the cell extracts environment. Additionally, inhibition effects of adenosine diphosphate, ammonium sulfate, and sodium hydrogen phosphate have also been investigated. The method not only provides a universal platform for monitoring activity and inhibition of nucleotide kinase but also shows great potential in biological process researches, drug discovery, and clinic diagnostics.     

六自由度运动平台控制系统的神经网络优化

阐述了六自由度运动平台的控制原理，并根据控制系统的特点，提出采用基于RBF和BP神经网络来改进常规PID控制器实现系统控制性能。在该控制系统结构中，提出了在RBF网络辨识Jacobian的基础上，将BP神经网络引入了平台控制系统中PID控制器的控制参数在线整定的算法，最后给出了在MATLAB下的具体仿真算法。     

Large-area manipulation of microdroplets by holographic optical tweezers based on a hybrid diffractive system

We report on large-area manipulation of microdroplets by holographic optical tweezers based on a hybrid diffractive system, in which a static computer-generated hologram and a spatial light modulator (SLM) are used. The hybrid diffractive system is useful to manipulate microdroplets on distant areas with the same manner. Experimental results demonstrated that microdroplets were transported successfully in parallel with approximately equivalent velocities over the entire manipulation area. Fusion of microdroplets was also achieved at a position where the optical pattern generated by the SLM alone did not reach.     

基于峰度检验和小波包分解的海洋平台脉冲噪声处理方法研究

海洋平台处于复杂的环境中,不仅受到风浪流的作用,而且还受到平台本身各种机器运转的影响,所以在平台上采集的信号一般都不可避免地包含大量噪声.其中,脉冲噪声是振动响应数据处理中经常遇到的干扰,严重影响了后续损伤敏感特征的提取.为了更好地消除脉冲噪声对特征提取的不利影响,引入了一种峰度检验和小波包阈值联合的降噪方法.将测得的...     

基于LabVIEW的导引头平台参数测试分析系统的设计

分析了建立虚拟仪器结构的导引头平台参数测试系统的必要性和现实意义；提出了本测试系统的技术方案；重点讨论基于LabVlEW的虚拟仪器模块部分的系统结构，给出了系统主体子系统一虚拟数字存储示波器（客户端软件）的设计过程及方法。该系统的成功开发实践表明：用虚拟仪器的解决方案可快速、高效、经济地实现功能完善、交互性强、扩展升级方便的测试系统。     

Integrated microanalytical system based on electrochemical detection and cell positioning

The development and preliminary evaluation of an integrated microanalytical system based on electrochemical detection and cell positioning is reported here. The chip includes ion-sensitive field effect transistors (ISFET), a single pair of castellated microelectrodes and a reference Ag/AgCl microelectrode. The ISFETs have shown good operating characteristics, with a 52 mV/pH response. Yeast cells and bacteria have been positioned on the gate region of the ISFET sensor using single pair of castellated microelectrodes.