Glycoprotein analysis using protein microarrays and mass spectrometry

Protein glycosylation plays an important role in a multitude of biological processes such as cell–cell recognition, growth, differentiation, and cell death. It has been shown that specific glycosylation changes are key in disease progression and can have diagnostic value for a variety of disease types such as cancer and inflammation. The complexity of carbohydrate structures and their derivatives makes their study a real challenge. Improving the isolation, separation, and characterization of carbohydrates and their glycoproteins is a subject of increasing scientific interest. With the development of new stationary phases and molecules that have affinity properties for glycoproteins, the isolation and separation of these compounds have advanced significantly. In addition to detection with mass spectrometry, the microarray platform has become an essential tool to characterize glycan structure and to study glycosylation‐related biological interactions, by using probes as a means to interrogate the spotted or captured glycosylated molecules on the arrays. Furthermore, the high‐throughput and reproducible nature of microarray platforms have been highlighted by its extensive applications in the field of biomarker validation, where a large number of samples must be analyzed multiple times. This review covers a brief survey of the other experimental methodologies that are currently being developed and used to study glycosylation and emphasizes methodologies that involve the use of microarray platforms. This review describes recent advances in several options of microarray platforms used in glycoprotein analysis, including glycoprotein arrays, glycan arrays, lectin arrays, and antibody/lectin arrays. The translational use of these arrays in applications related to characterization of cells and biomarker discovery is also included. © 2010 Wiley Periodicals, Inc., Mass Spec Rev 29:830–844, 2010     

Microchip technology in mass spectrometry

Microfabrication of analytical devices is currently of growing interest and many microfabricated instruments have also entered the field of mass spectrometry (MS). Various (atmospheric pressure) ion sources as well as mass analyzers have been developed exploiting microfabrication techniques. The most common approach thus far has been the miniaturization of the electrospray ion source and its integration with various separation and sampling units. Other ionization techniques, mainly atmospheric pressure chemical ionization and photoionization, have also been subject to miniaturization, though they have not attracted as much attention. Likewise, all common types of mass analyzers have been realized by microfabrication and, in most cases, successfully applied to MS analysis in conjunction with on‐chip ionization. This review summarizes the latest achievements in the field of microfabricated ion sources and mass analyzers. Representative applications are reviewed focusing on the development of fully microfabricated systems where ion sources or analyzers are integrated with microfluidic separation devices or microfabricated pums and detectors, respectively. Also the main microfabrication methods, with their possibilities and constraints, are briefly discussed together with the most commonly used materials. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 29:351‐391, 2010     

Recent advancements in LC-MS based analysis of biotoxins: Present and future challenges

There has been a rising concern regarding the harmful impact of biotoxins, source of origin, and the determination of the specific type of toxin. With numerous reports on their extensive spread, biotoxins pose a critical challenge to figure out their parent groups, metabolites, and concentration. In that aspect, liquid chromatography-mass spectrometry (LC-MS) based analysis paves the way for its accurate identification and quantification. The biotoxins are ideally categorized as phytotoxins, mycotoxins, shellfish-toxins, ciguatoxins, cyanotoxins, and bacterial toxins such as tetrodotoxins. Considering the diverse nature of biotoxins, both low-resolution mass spectrometry (LRMS) and high-resolution mass spectrometry (HRMS) methods have been implemented for their detection. The sample preparation strategy for complex matrix usually includes “QuEChERS” extraction or solid-phase extraction coupled with homogenization and centrifugation. For targeted analysis of biotoxins, the LRMS consisting of a tandem mass spectrometer operating in multiple reaction monitoring mode has been widely implemented. With the help of the reference standard, most of the toxins were accurately quantified. At the same time, the suspect screening and nontarget screening approach are facilitated by the HRMS platforms during the absence of reference standards. Significant progress has also been made in sampling device employment, utilizing novel sample preparation strategies, synthesizing toxin standards, employing hybrid MS platforms, and the associated data interpretation. This critical review attempts to elucidate the progress in LC-MS based analysis in the determination of biotoxins while pointing out major challenges and suggestions for future development.     

双适配体夹心微阵列芯片在凝血酶检测中的应用

核酸适配体不仅具备抗体分子的专一性识别性能,而且还具备其独特的优异特性。凡涉及到抗体的识别范畴,几乎都可以用适配体来取代抗体。微阵列芯片具有高通量、微量化和自动化等优点。本论文以凝血酶为检测对象,在优化氨基化适配体（T29）在醛基化玻璃基片上的固定条件,并对固定结果进行表征的基础上,设计制作了用于凝血酶检测的基于双适配体夹心原理的微阵列芯片。结果表明,氨基化适配体T29．1在醛基化玻璃基片上的固定浓度为5gM,最佳的固定缓冲液为含有37．5％DMSO的3＊SSC,在微阵列芯片加工制作的基础上,利用双适配体夹心法的原理初步实现了凝血酶的检测,这为利用微阵列芯片实现多种物质的同时检测奠定了方法学基础。     

适体传感器的电化学阻抗谱研究

电化学阻抗谱是以小振幅的正弦波电位（或电流）为扰动信号的电化学分析方法。它是研究电极表面生物敏感膜的形成、电极过程动力学以及测定固体电解质电导率的重要工具。以适体为新一代生物识别分子所构成的适体传感器,被用于蛋白质、药物和核酸的检测。电化学阻抗谱是表征和检测适体传感器识别前后电极界面性质变化的一种较新且强有力的分析技术,可以定量测定配体及实时研究适体与配体结合过程的动力学特性。本文在简要介绍电化学阻抗谱基本原理和分类的基础上,详细综述了近三年来电化学阻抗谱在适体传感器方面的研究应用。     

一种连续分离纳米颗粒的确定性横向迁移装置

确定性横向迁移（DLD）是一种利用微米尺寸障碍物阵列对含有颗粒或分子混合物的液流在横跨流体方向上进行连续分离的技术。利用DLD原理,本文介绍了一种连续分离纳米颗粒混合物（颗粒半径可小到70nm）的装置。该装置根据颗粒的半径大小,可在几秒钟内完成分离。文中还研究了装置的几何形状和分离参数之间的关系。这项分离技术最终将被应用到蛋白质分子分离方面。     

Review of mobile mapping and surveying technologies

Mobile surveying is currently one of the most popular topics in the LiDAR industry. The collection of highly precise point cloud data is provided by laser scanning systems on moving platforms with an integrated navigation solution. The potential of LiDAR based mobile surveying technology is now well proven. This article introduces an analysis on the current performance of some outstanding mobile terrestrial laser scanning systems. In this work, an overview of the positioning, scanning and imaging devices integrated into these systems is also presented. As part of this study, a systematic comparison of the navigation and LiDAR specifications provided by the manufacturers is provided. Our review suggests that mobile laser scanning systems can mainly be divided into two categories (mapping and surveying) depending on their final purpose, accuracy, range and resolution requirements. A refined integrated analysis based on hardware components could be expected to cause further improvements on these results.     

Development of a diagnostic technique based on Cherenkov effect for measurements of fast electrons in fusion devices

A diagnostic technique based on the Cherenkov effect is proposed for detection and characterization of fast (super-thermal and runaway) electrons in fusion devices. The detectors of Cherenkov radiation have been specially designed for measurements in the ISTTOK tokamak. Properties of several materials have been studied to determine the most appropriate one to be used as a radiator of Cherenkov emission in the detector. This technique has enabled the detection of energetic electrons (70 keV and higher) and the determination of their spatial and temporal variations in the ISTTOK discharges. Measurement of hard x-ray emission has also been carried out in experiments for validation of the measuring capabilities of the Cherenkov-type detector and a high correlation was found between the data of both diagnostics. A reasonable agreement was found between experimental data and the results of numerical modeling of the runaway electron generation in ISTTOK.     

A frequency response based structural damage localization method using independent component analysis

Vibration-based structural damage detection has been the focus of attention by many researchers over the last few decades. However, most methods proposed for this purpose utilize extracted modal parameters or some indices constructed on the basis these parameters. Our literature review revealed that few papers have employed frequency response functions (FRFs) for detecting structural damage. In this paper, a technique is presented for damage detection which is based on measured FRFs. Independent component analysis (ICA) has been implemented on the spatiotemporal responses in each frequency in order to reduce the dimension of the data. This is based on the concept that the forced harmonic response of a linear vibrating system can be fully captured utilizing a single ICA mode. A different approach is also presented in which ICA is applied to the frequency domain data. Operational deflection shapes (ODSs) have been decomposed using ICA to localize the damage. The efficiency of both methods is demonstrated through some numerical and experimental case studies.     

Analytical Performance of CE Microchips with Amperometric Detection

Abstract

Miniaturized Total Analysis Systems (µTAS), such as microchip electrophoresis devices are promising tools for analytical purposes. Capillary electrophoresis (CE) microchips made of various materials, e.g., poly(methylmethacrylate) (PMMA). Topas (thermoplastic olefin polymer of amorphous structure), and glass have been evaluated in this work. An electrochemical detection that combines adequately with these polymeric and glass microchips has been employed. The performance of amperometric detectors based on an end‐channel configuration was tested. Thus, integration and alignment of gold/platinum wire and thick‐film (screen‐printed carbon electrodes) working electrodes was studied. In order to verify the correct alignment of the end‐channel metal‐wire detector, a gold‐based dual electrode detector was also employed. The dual detector was based on a gold film within the separation channel and a gold wire at the end of the channel. The microchip pretreatment, which can affect the charge on the channel surface and electroosmotic flow (EOF), has been discussed, as well as the separation and injection performance.     

Rolling element bearing diagnostics—A tutorial

This tutorial is intended to guide the reader in the diagnostic analysis of acceleration signals from rolling element bearings, in particular in the presence of strong masking signals from other machine components such as gears. Rather than being a review of all the current literature on bearing diagnostics, its purpose is to explain the background for a very powerful procedure which is successful in the majority of cases. The latter contention is illustrated by the application to a number of very different case histories, from very low speed to very high speed machines. The specific characteristics of rolling element bearing signals are explained in great detail, in particular the fact that they are not periodic, but stochastic, a fact which allows them to be separated from deterministic signals such as from gears. They can be modelled as cyclostationary for some purposes, but are in fact not strictly cyclostationary (at least for localised defects) so the term pseudo-cyclostationary has been coined. An appendix on cyclostationarity is included. A number of techniques are described for the separation, of which the discrete/random separation (DRS) method is usually most efficient. This sometimes requires the effects of small speed fluctuations to be removed in advance, which can be achieved by order tracking, and so this topic is also amplified in an appendix. Signals from localised faults in bearings are impulsive, at least at the source, so techniques are described to identify the frequency bands in which this impulsivity is most marked, using spectral kurtosis. For very high speed bearings, the impulse responses elicited by the sharp impacts in the bearings may have a comparable length to their separation, and the minimum entropy deconvolution technique may be found useful to remove the smearing effects of the (unknown) transmission path. The final diagnosis is based on “envelope analysis” of the optimally filtered signal, but despite the fact that this technique has been used for 40 years in analogue form, the advantages of more recent digital implementations are explained.     

Overview of one transistor type of hybrid organic ferroelectric non-volatile memory

Organic ferroelectric memory devices based on field effect transistors that can be configured between two stable states of on and off have been widely researched as the next generation data storage media in recent years.This emerging type of memory devices can lead to a new instrument system as a potential alternative to previous non-volatile memory building blocks in future processing units because of their numerous merits such as cost-effective process,simple structure and freedom in substrate choices.This bi-stable non-volatile memory device of information storage has been investigated using several organic or inorganic semiconductors with organic ferroelectric polymer materials.Recent progresses in this ferroelectric memory field,hybrid system have attracted a lot of attention due to their excellent device performance in comparison with that of all organic systems.In this paper,a general review of this type of ferroelectric non-volatile memory is provided,which include the device structure,organic ferroelectric materials,electrical characteristics and working principles.We also present some snapshots of our previous study on hybrid ferroelectric memories including our recent work based on zinc oxide nanowire channels.     

机械完整性技术在海上采油平台延期服役决策中的应用

胜利海洋采油厂在海上布置有大量导管架采油平台,从2008年开始已有数十座平台陆续达到设计使用寿命。文中阐述了我国浅海区域导管架采油平台延寿管理的难点,从海上生产企业的角度出发,提出了基于风险的系统性解决思路,并借鉴机械完整性方法,规划了导管架平台延期服役管理框架与后续工作。     

Design and operation of a portable scanner for high performance microchip capillary array electrophoresis

We have developed a compact, laser-induced fluorescence detection scanner, the multichannel capillary array electrophoresis portable scanner (McCAEPs) as a platform for electrophoretic detection and control of high-throughput, integrated microfluidic devices for genetic and other analyses. The instrument contains a confocal optical system with a rotary objective for detecting four different fluorescence signals, a pneumatic system consisting of two pressure/vacuum pumps and 28 individual addressable solenoid valves for control of on-chip microvalves and micropumps, four Polymerase Chain Reaction (PCR) temperature control systems, and four high voltage power supplies for electrophoresis. The detection limit of the instrument is ~20 pM for on-chip capillary electrophoresis of fluorescein dyes. To demonstrate the system performance for forensic short tandem repeat (STR) analysis, two experiments were conducted: (i) electrophoretic separation and detection of STR samples on a 96-lane microfabricated capillary array electrophoresis microchip. Fully resolved PowerPlex(?) 16 STR profiles amplified from 1 ng of 9947A female standard DNA were successfully obtained; (ii) nine-plex STR amplification, sample injection, separation, and fluorescence detection of 100-copy 9948 male standard DNA in a single integrated PCR- capillary electrophoresis microchip. These results demonstrate that the McCAEPs can be used as a versatile control and detection instrument that operates integrated microfluidic devices for high-performance forensic human identification.     

基于LABVIEW的车辆传动与控制实验台的研制

根据工程机械与作业介质相互作用研究的需要,在总结国内类似车辆实验台的基础上,研制出基于LABVIEW测控系统的车辆传动与控制实验台。本文在论述实验台工作原理的基础上,重点介绍了实验台液压传动系统的基本原理以及基于虚拟仪器开发平台LABVIEW的测控系统。     

一种基于支持向量机的烟叶异物检测方法

为解决基于颜色空间的检测方法难以剔除与烟叶颜色相同或相近异物的难题,提出了基于支持向量机的检测方法。首先采用Laws算子,对烟叶图像进行预处理,初步分离出目标与背景;然后,根据纹理特征明显与否将待处理区域分为2类;最后,使用支持向量机分别对2个预分类的结果在频域做细分类。试验结果表明,所提方法可以准确地检测出烟叶中的各种异物,误检率较低,满足实际使用要求。     

一种基于支持向量机的烟叶异物检测方法

为解决基于颜色空间的检测方法难以剔除与烟叶颜色相同或相近异物的难题,提出了基于支持向量机的检测方法。首先采用Laws算子,对烟叶图像进行预处理,初步分离出目标与背景;然后,根据纹理特征明显与否将待处理区域分为2类;最后,使用支持向量机分别对2个预分类的结果在频域做细分类。试验结果表明,所提方法可以准确地检测出烟叶中的各种异物,误检率较低,满足实际使用要求。     

A method for discriminating original pulses in online partial discharge measurement

Partial discharge (PD) measurement is a promising method for condition assessment of insulation systems in high voltage equipments. Conventional PD measuring systems have some difficulties in the measurements especially in online conditions and noisy environments. There is a growing tendency to use new measuring systems for separation of PD pulses from different sources and rejection of external noises. In this investigation a new ultra wideband PD measuring system and relevant methodology are discussed. The proposed system uses an efficient detection method for extracting PD pulses embedded in noisy signal, meanwhile, a wavelet multiresolution analysis is applied to reduce background and communication noise level. In this paper some new and modified features for pulse classification procedure have been proposed. The proposed system, methodology and features have been implemented on a hydrogenerator and also a power transformer. Finally performance of the system is discussed.     

EMCCD技术--单光子水平的成像探测

对于极微弱光信号的探测，长期以来一直采用ICCD设备，但其光电转换效率低、空间分辨率差、以及高增益下怕强光的缺点使其使用当中产生诸多不便；现在，EMCCD技术的出现克服了这些问题，尤其是在对极微弱光信号的实时快速动态探测方面具有先天的优势；其探测灵敏度可达对真正单光子事件的检测。