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Array System (array + system)
Selected AbstractsPoster Sessions AP13: Novel Techniques and TechnologiesJOURNAL OF NEUROCHEMISTRY, Issue 2002J. K. Yao Studies of the antioxidant defense system and the monoamine metabolic pathways are often complicated by cumbersome analytical methods, which require separate and multistep extraction and chemical reaction procedures. Thus, measurements of multiple parameters are limited in relatively small biological samples. High performance liquid chromatography (HPLC) coupled with a Coulometric Multi-Electrode Array System (CMEAS) provides us a convenient and most sensitive tool to measure low molecular weight, redox-active compounds in biological sample. The deproteinized sample was analyzed on a HPLC coupled with a 16-channel CMEAS, which incremented from 60 to 960 mV in 60 mV steps. Each sample was run on a single column (Meta-250, 4.6 × 250 mm) under a 150-minute complex gradient that ranged from 0% B (A: 1.1% pentane sulfonic acid) to 20% B (B: 0.1 m lithium acetate in mixture of methanol, acetonenitrile and isopropanol), with a flow rate of 0.5 mL/min. We have developed an automated procedure to simultaneously measure various antioxidant, oxidative stress marker, and monoamine metabolites in a single column with binary gradient. No other chemical reactions are necessary. In order to reduce the running time and yet achieve a reproducible retention time by the autosampler injection, our gradient elution profile was modified to produce a shorter equilibration time and to compensate for the initial contamination of mobile phase B following the first injection. Without the use of two columns in series and peak suppresser/gradient mixer, we have simplified the previously published method to measure over 20 different antioxidants, oxidative stress markers and monoamine metabolites simultaneously in biological samples. [source] Efficient, large-scale archaeological prospection using a true three-dimensional ground-penetrating Radar Array systemARCHAEOLOGICAL PROSPECTION, Issue 3 2010Immo Trinks Abstract The Swedish UNESCO World Cultural Heritage site of the Birka and Hovgården Iron Age settlements is well suited for the testing of high-resolution archaeological prospection methods. In May 2006 ground-penetrating radar (GPR) and magnetometer test measurements were conducted at Birka, resulting in data of outstanding quality and new archaeological discoveries, but also demonstrating the need for increased spatial sampling regarding GPR prospection at complex Scandinavian sites. Therefore Birka was selected as a testing ground for a pilot study investigating the suitability of the novel multichannel GPR array system MIRA (MALÅ Imaging Radar Array) for efficient, large-scale GPR surveys with very dense spatial sampling. The study was conducted in May 2008 by MALÅ Geoscience AB in collaboration with the archaeological prospection unit of the Swedish National Heritage Board. The very high-resolution three-dimensional GPR pilot survey demonstrated that it is possible to survey 1,ha and more per day with 8,cm cross-line spacing, mapping archaeological structures in unprecedented resolution, such as postholes of only 25,cm diameter. This paper describes the tested technology and methodology as well as the fieldwork and the results of the study. Copyright © 2010 John Wiley & Sons, Ltd. [source] CE combined with rolling circle amplification for sensitive DNA detectionELECTROPHORESIS, Issue 2 2008Ni Li Abstract Here we describe an assay which combines CE with rolling circle amplification (RCA) for sensitive DNA detection and quantification. RCA is an isothermal DNA replication technique that generates a long ssDNA with tandem repeats. It requires simpler temperature control in reaction and offers higher sequence specificity and greater quantitation capability compared to other amplification technologies. In this study, RCA amplified the DNA target via a circular template, and the product was digested into monomers for CE analysis. Less than 2,fmol of the DNA target could easily be detected using this RCA-CE assay and the assay has a dynamic range of two orders of magnitudes. Moreover, simultaneous detection of both the target DNA and the internal standard was achieved by designing two padlock probes with different sizes, which could significantly improve the quantification accuracy. The RCA-CE assay is easy to perform, readily adaptable for detection of multiple targets because of the high resolution power of CE, and is compatible with other applications employing RCA as a signal amplification tool. Additionally, this assay can be used with a capillary array system to perform sensitive, high-throughput genetic screening. [source] Optoelectrothermic Control of Highly Integrated Polymer-Based MEMS Applied in an Artificial SkinADVANCED MATERIALS, Issue 9 2009Andreas Richter A large-scale integration technology for MEMS based on the optoelectrothermic control of a temperature-sensitive hydrogel is described and exemplified using an imaging array system, a so-called artificial skin. The hydrogel itself acts as active functional unit, i.e., as actuator. The artificial skin comprises more than 4,000 individual actuators and provides both, visual and palpable artificial impressions of a surface. [source] Prediction of Microbial and Sensory Quality of Cold Smoked Atlantic Salmon (Salmo salar) by Electronic NoseJOURNAL OF FOOD SCIENCE, Issue 9 2005Gudrun Olafsdottir ABSTRACT: Quality changes of cold smoked salmon from 4 different smokehouses in Europe were monitored by a prototype gas-sensor array system, the FishNose. Samples were stored in different packaging (vacuum and Modified Atmosphere Packaging [MAP]) for up to 4 wk under controlled storage conditions at 5 °C and 10 °C. Quality criteria based on sensory attributes (sweet/sour, off, and rancid odor), and total viable counts and lactic acid bacteria counts were established and used for classification of samples based on the responses of the FishNose. The responses of the gas-sensors correlated well with sensory analysis of spoilage odor and microbial counts suggesting that they can detect volatile microbially produced compounds causing spoilage odors in cold-smoked salmon during storage. The system is therefore ideal for fast quality control related to freshness evaluation of smoked salmon products. Partial least squares (PLS) regression models based on samples from single producer showed better performance than a global model based on products from different producers to classify samples of different quality. [source] A research on determination of explosive gases utilizing cataluminescence sensor arrayLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 4-5 2005Xiaoan Cao Abstract In this paper, we propose a model of a sensor array system, which consists of three cataluminescence sensors based on nanosized SrCO3, , -Al2O3 and BaCO3 as catalysts, for quantitative analysis of the explosive gases of propane, n -butane and iso-butane in a mixture. Six linear regression equations of the cataluminescence intensity vs. the gas concentrations in the range 2000,10 000 ppm were established from the sensor array system at two working temperatures, as the explosive gases show different sensitivity to the three sensors. The least squares method was employed for solving the simultaneous equations and quantifying the concentrations of the three components. The detection limits (3,) of propane, n -butane and iso-butane on SrCO3, , -Al2O3 and BaCO3 sensors are 50, 40 and 20 ppm, 80, 60 and 40 ppm, and 20, 10 and 5 ppm, respectively. The concentrations of two artificial samples containing the tertiary mixture were analysed with satisfactory results. Copyright © 2005 John Wiley & Sons, Ltd. [source] Altered cytokine profiles in patients with Chuvash polycythemia,AMERICAN JOURNAL OF HEMATOLOGY, Issue 2 2009Xiaomei Niu Chuvash polycythemia results from a homozygous 598C>T mutation in exon 3 of the von Hippel-Lindau (VHL) gene. This disrupts the normoxia pathway for degrading hypoxia inducible factor (HIF)-1, and HIF-2, causing altered expression of HIF-1 and HIF-2 inducible genes. As hypoxia induces expression of pro-inflammatory cytokines, we hypothesized that there might be an elevation of Th1 cytokines in the setting of Chuvash polycythemia. We analyzed plasma concentrations of Th1 (interleukins-2 and 12, interferon-,, granulocyte-monocyte colony-stimulating factor, tumor necrosis factor-,) and Th2 cytokines (interleukins-4, 5, 10, and 13) using the Bio-Plex multiplex suspension array system in 34 VHL598C>T homozygotes and 32 VHL wild-type participants from Chuvashia. Concentrations of all the Th1 and Th2 cytokines measured were elevated in the VHL598C>T homozygotes compared with the control wild-type participants, but the ratios of Th1 to Th2 cytokines did not differ by genotype. In parallel, peripheral blood concentrations of CD4 positive T-helper cells and CD4/CD8 ratio were lower in the VHL598C>T homozygotes. In conclusion, the up-regulated hypoxic response in Chuvash polycythemia is associated with increased plasma products of both the Th1 and Th2 pathways, but the balance between the two pathways seems to be preserved. Am. J. Hematol., 2009. © 2008 Wiley-Liss, Inc. [source] Near-infrared analysis of fennel (Foeniculum vulgare Miller) on different spectrometers,basic considerations for a reliable networkPHYTOCHEMICAL ANALYSIS, Issue 5 2003Boris Steuer Abstract The aim of this study was to investigate the accuracy and transferability of near-infrared (NIR) calibrations for estimating the content and composition of the volatile fraction in fennel fruits (Foeniculum vulgare Miller) as an example of medicinal and spice plants. A master calibration with spectra obtained on a scanning monochromator was generated using 345 samples from three different harvests (1997,1999). A subset of 70 samples from 1999 was also measured on a dispersive grating and a scanning diode array system to gain an insight into the in,uence of sample presentation and scanning techniques. For all instruments, calibrations with standard errors in the range of the reference method were achieved. Furthermore the in,uence of storage on NIR spectra and, additionally, the potential of transferring spectra between both scanning monochromators was studied. Copyright © 2003 John Wiley & Sons, Ltd. [source] Serum chemokine profile in patients with bullous pemphigoidBRITISH JOURNAL OF DERMATOLOGY, Issue 3 2007H. Nakashima Summary Background, Bullous pemphigoid (BP) is an autoimmune inflammatory disease causing blister formation at the dermoepidermal junction. Cutaneous infiltration of activated CD4+ T cells and eosinophils is an early event in blister formation during the disease process, suggesting that the trafficking of circulating leucocytes through the sites of inflammation is crucial in the pathogenesis of the disease. While the accumulated evidence suggests that some cytokines are involved in the pathogenesis, there have been few reports about serum chemokine profiles in patients with BP. Objectives, To determine serum profiles of various chemokines and their clinical association in patients with BP. Methods, Concentrations of 10 chemokines , interferon (IFN)- , -inducible protein-10 (IP-10), monokine induced by IFN- , (MIG), macrophage inflammatory protein (MIP)-1,, MIP-1,, RANTES, eotaxin, monocyte chemoattractant protein (MCP)-1, MCP-2, MCP-3 and growth-regulated oncogene- ,, were measured in serum samples from 38 patients with BP, 16 with pemphigus vulgaris (PV) and 17 normal controls using a sandwich immunoassay-based multiplex protein array system. Results, While there was no significant increase in any serum chemokine levels in patients with PV, serum levels of IP-10 and MCP-1 were significantly increased in patients with BP compared with healthy controls. Furthermore, serum levels of IP-10, MIG, MCP-1 and eotaxin in patients with BP increased significantly with disease severity as determined by the area affected. Conclusions, These observations suggest that an elaborately orchestrated network of chemokines, especially MCP-1 and IP-10, contributes to the pathomechanism of BP. [source] Real-time signal processing for high-density microelectrode array systemsINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 11 2009K. Imfeld Abstract The microelectrode array (MEA) technology is continuously progressing towards higher integration of an increasing number of electrodes. The ensuing data streams that can be of several hundreds or thousands of Megabits/s require the implementation of new signal processing and data handling methodologies to substitute the currently used off-line analysis methods. Here, we present one approach based on the hardware implementation of a wavelet-based solution for real-time processing of extracellular neuronal signals acquired on high-density MEAs. We demonstrate that simple mathematical operations on the discrete wavelet transform (DWT) coefficients can be used for efficient neuronal spike detection and sorting. As the DWT is particularly well suited for implementation on dedicated hardware, we elaborated a wavelet processor on a field programmable gate array (FPGA) in order to compute the wavelet coefficients on 256 channels in real-time. By providing sufficient hardware resources, this solution can be easily scaled up for processing more electrode channels. Copyright © 2008 John Wiley & Sons, Ltd. [source] Simulation of DNA electrophoresis in systems of large number of solvent particles by coarse-grained hybrid molecular dynamics approachJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 4 2009Rong Wang Abstract Simulation of DNA electrophoresis facilitates the design of DNA separation devices. Various methods have been explored for simulating DNA electrophoresis and other processes using implicit and explicit solvent models. Explicit solvent models are highly desired but their applications may be limited by high computing cost in simulating large number of solvent particles. In this work, a coarse-grained hybrid molecular dynamics (CGH-MD) approach was introduced for simulating DNA electrophoresis in explicit solvent of large number of solvent particles. CGH-MD was tested in the simulation of a polymer solution and computation of nonuniform charge distribution in a cylindrical nanotube, which shows good agreement with observations and those of more rigorous computational methods at a significantly lower computing cost than other explicit-solvent methods. CGH-MD was further applied to the simulation of DNA electrophoresis in a polymer solution and in a well-studied nanofluidic device. Simulation results are consistent with observations and reported simulation results, suggesting that CGH-MD is potentially useful for studying electrophoresis of macromolecules and assemblies in nanofluidic, microfluidic, and microstructure array systems that involve extremely large number of solvent particles, nonuniformly distributed electrostatic interactions, bound and sequestered water molecules. © 2008 Wiley Periodicals, Inc. J Comput Chem 2009 [source] Low-loss and high-isolation active type cascode switch in 0.13-,m CMOS for millimeter-wave applicationsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2009Dong Ho Lee Abstract This article presents two types of switches which are fabricated in 0.13-,m standard CMOS process characterized up to 50 GHz. The first is the conventional series NMOS switch with an optimum gate width which is adjusted by measuring various sized devices. The second is a new active type cascode switch for millimeter-wave phased array systems. The series NMOS switch produces 3 dB insertion loss and 7.5 dB isolation at 40 GHz. In contrast, the active type cascode switch has 7.5 dB better insertion loss (Gain) and 20 dB better isolation than the passive switch at 40 GHz. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1856,1858, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24476 [source] Biomedical applications of capillary electrophoresis with laser-induced fluorescence detectionBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 7-8 2001Ximena Páez Abstract Capillary electrophoresis (CE) is a high-efficiency analytical technique that has had a great impact as a tool in biomedical research, clinical and forensic practice in the last ten years. Only in one of the applications, the DNA analysis, it has had an explosive exponential growth in the last few years. This impact is expressed in an enormous amount of CE articles and many reviews. The CE advantages with respect to other analytical techniques: the required very small sample volume, rapid analysis, great resolution power and low costs, have made this technique ideal for the analysis of a numerous endogenous and exogenous substances present in biological fluids. The different modes of CE have been coupled to different detection techniques such as UV-absorbance, electrochemical, mass spectrometry and laser-induced fluorescence detection (LIFD) to detect different nature and molecular size separated analytes. This review focuses mostly on the applications of CE,LIFD, to measure drugs and endogenous neuroactive substances such as amino acids and monoamines, especially in microdialysis samples from experimental animals and humans. CE,LIFD trends are discussed: automated faster analysis with capillary array systems, resolution power improvement, higher detection sensitivity, and CE systems miniaturization for extremely small sample volume, in order to make CE easier and affordable to the lab bench or the clinical bed. Copyright © 2001 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||