bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved capillary electrophoresis method for the determination of carbohydrate‐deficient transferrin in patient sera
Authors: Lanz Christian , Kuhn Martina , Deiss Veronika , Thormann Wolfgang 
Published: July 2004

AbstractCapillary zone electrophoresis (CZE) with a dynamic double coating formed by charged polymeric reagents represents an effective tool for the separation of iron‐saturated transferrin (Tf) isoforms and thus the determination of carbohydrate‐deficient transferrin (CDT, sum of asialo‐, monosialo‐ and disialo‐Tf in relation to total Tf) in human serum. Using the CEofix‐CDT reagents, a 50 μm inner diameter (ID) capillary of 60 cm total length and the P/ACE MDQ under optimized instrumental conditions (20 kV and 30°C) is demonstrated to provide outstanding assay precision for the determination of CDT in human serum. For CDT levels of 1.0% and 4.5%, precision relative standard deviation (RSD) values (n = 8) were determined to be < 3.0% and < 1.5%, respectively. During the first year of operation under routine conditions, more than 600 patient samples were analyzed in a total of 62 sets of runs. Except for selected samples of patients with severe liver diseases, interference‐free Tf patterns were detected. Asialo‐Tf was not detected in control sera and in patient sera with a CDT level < 1.70%, but became detectable in 89.6% of sera with > 2.3% disialo‐Tf. Monosialo‐Tf was only detected in two sera containing > 13.3% CDT. The optimized CZE assay was applied to confirm positive CDT results produced by an immunoassay during long‐term monitoring of a patient which led to the determination of the elimination kinetics of asialo‐Tf, disialo‐Tf, and CDT after an episode of high alcohol consumption (estimated apparent half lifes of 4.86, 7.24, and 6.74 days, respectively). The optimized CZE assay with an upper reference limit for CDT of 1.70% represents an attractive alternative to high‐performance liquid chromatography (HPLC). It features simpler sample preparation, faster analysis time, and higher isoform resolution compared to the most recent HPLC approach and can thus be regarded as a new candidate of a reference method for CDT.
Mining the human cerebrospinal fluid proteome by immunodepletion and shotgun mass spectrometry
Authors: Maccarrone Giuseppina , Milfay Dale , Birg Isabel , Rosenhagen Marcus , Holsboer Florian , Grimm Rudolf , Bailey Jerome , Zolotarjova Nina , Turck Christoph W. 
Published: July 2004

AbstractWe have analyzed the proteome of human cerebrospinal fluid with the help of shotgun mass spectrometry. In order to identify low‐abundant proteins in these fluids, we have found it necessary to remove the abundant protein components from the mixture. Immunodepletion of the abundant proteins has allowed us to identify more than 100 proteins in cerebrospinal fluids from a patient suffering from normal pressure hydrocephalus. The identified proteins belong to a variety of different classes ranging from serum proteins to intracellular mediators that are involved in signal transduction and transcription. This work establishes a platform for future studies aimed at the comparative proteome analysis of cerebrospinal fluids from different groups of patients suffering from various psychiatric and neurological disorders.
Optimization of the electrokinetic supercharging preconcentration for high‐sensitivity microchip gel electrophoresis on a cross‐geometry microchip
Authors: Xu Zhongqi , Hirokawa Takeshi 
Published: July 2004

AbstractWe developed a novel on‐line preconcentration procedure for microchip gel electrophoresis (MCGE), which enables application of electrokinetic supercharging (EKS) for highly sensitive detection of DNA fragments on a cross‐geometry microchip. In comparison with conventional pinched injection using the cross microchip, the present approach allows loading a much larger amount of the sample by taking advantage of a newly developed operational mode. In order to obtain high preconcentration effect and prevent splitting of an enriched sample into subchannels, i.e., off the detector range, effects of the voltage applied on the reservoirs and the time of isotachophoretic preconcentration were examined. The optimal balance between the voltage and time was found for a high‐sensitivity analysis of DNA fragments. After experimental optimization the detection limit of a 150 bp fragment was as low as 0.22 mg/L (S/N = 3) that is 10 times better than using the conventional pinched injection.
Automated carbohydrate profiling by capillary electrophoresis: A bioindustrial approach
Authors: Khandurina Julia , Blum David L. , Stege Justin T. , Guttman András 
Published: July 2004

AbstractAutomated, high‐resolution, quantitative, high‐throughput analysis of mono‐ and oligosaccharides, produced by enzymatic digestion of cellohexaose (model substrate) and lignocellulosic biomass, is demonstrated using high‐performance capillary electrophoresis in conjunction with a single‐step fluorophore labeling strategy for sensitive laser‐induced fluorescence detection. Unattended batch sample processing from 96‐well plates enabled reliable industrial‐scale carbohydrate analysis. Excellent resolution of mono‐ and oligosaccharides was achieved under suppressed electroosmotic flow conditions, using either covalently or dynamically coated fused‐silica capillary columns. The proposed approach readily supports the demands of bioindustrial operation environments with respect to high‐throughput carbohydrate profiling.
Alkali‐stable high‐pI isoelectric membranes for isoelectric trapping separations
Authors: Lalwani Sanjiv , Shave Evan , Fleisher Helen C. , Nzeadibe Kingsley , Busby M. Brent , Vigh Gyula 
Published: July 2004

AbstractAlkali‐stable, high‐pI isoelectric membranes have been synthesized from quaternary ammonium derivatives of cyclodextrins and poly(vinyl alcohol), and bifunctional cross‐linkers, such as glycerol‐1,3‐diglycidyl ether. The new, high‐pI isoelectric membranes were successfully applied as cathodic membranes in isoelectric trapping separations in place of the hydrolytically more labile, polyacrylamide‐based cathodic isoelectric membranes, and permitted the use of catholytes as alkaline as 1 M NaOH. The new high‐pI isoelectric membranes have shown excellent mechanical stability, low electric resistance and long life times, even when subjected to electrophoresis with current densities as high as 80 mA/cm2.
A column gel electrophoresis‐coupled genomic DNA subtractive hybridization technique
Authors: Ozawa Kazuo , McElgunn Cathal J. , Yasukochi Takanori , Shibanaka Yasuhiko 
Published: July 2004

AbstractWe have developed a DNA subtractive hybridization technique especially designed for mammalian genome comparison. The core of this protocol is a newly devised denaturant‐containing polyacrylamide gel formed in a glass‐column. In this gel system, the following DNA manipulation steps are carried out sequentially: size separation by electrophoresis, heat‐denaturation, renaturation, and recovery. In the first step, a mixture of tester and driver DNA fragments are segregated according to their size whilst keeping their double‐stranded forms. This reduces the complexity of the original genomic DNA fragments and also segregates DNA fragments having closely related sequences. In the second step, fractionated DNA fragments are quickly denatured and subjected to successive subtractive hybridization in situ by controlling gel temperature in a water bath. In the third step, DNA fragments are recovered by electrophoresis towards the reverse‐orientation and are adsorbed onto ion‐exchange beads. Two lines of experiments show that our protocol is able to highly enrich or directly extract differences among genomic DNA samples.
On‐line capillary electrophoresis‐mass spectrometry for the analysis of biomolecules
Authors: Hernández‐Borges Javier , Neusüß Christian , Cifuentes Alejandro , Pelzing Matthias 
Published: July 2004

AbstractMass spectrometry (MS) has become a key tool for the characterization of biologically relevant molecules in the last decade. Due to the complexity of most biological samples an upstream separation is essential. Capillary electrophoresis (CE) has gained much interest due to its high separation efficiency, speed, and often complementary selectivity to liquid chromatography. We describe the state‐of‐the‐art of on‐line CE‐MS for the analysis of molecules of biological origin. The characterization of peptides, including the study of post‐translational modifications, intact proteins, oligonucleotides, and related interaction studies are reviewed. Relevant publications are summarized in tables, including some important method parameters. Key applications are discussed with respect to the advantages and limitations of CE‐MS. Coupling interfaces, preconcentration techniques, capillary coatings, and the different CE techniques, e.g., capillary zone electrophoresis, capillary isoelectric focusing, capillary gel electrophoresis, etc. are briefly discussed against the background of their bioanalytical applications.
Virtual two‐dimensional gel electrophoresis of high‐density lipoproteins
Authors: Ogorzalek Loo Rachel R. , Yam Lang , Loo Joseph A. , Schumaker Verne N. 
Published: July 2004

AbstractHigh‐density lipoproteins (HDLs) isolated by immunoaffinity chromatography and separated by immobilized pH gradient‐isoelectric focusing (IPG‐IEF) were examined by mass spectrometry directly, applying a new proteomics technology, virtual two‐dimensional (2‐D) gel electrophoresis. A preliminary examination of HDL particles has revealed at least 42 unique masses for protein species with isoelectric points between pH 5.47–5.04, some of which have not been observed previously. By delivering masses of intact proteins from complex cellular mixtures in a format that correlates directly to classical 2‐D gel analyses, virtual 2‐D gel electrophoresis constitutes a general discovery tool to expose and monitor protein isoforms and post‐translational modifications. Furthermore, its general ability to deliver ions from sub‐picomole level proteins enmeshed in complex cellular mixtures potentially fulfills the need of top‐down proteomics to obtain intact protein ions from microscale samples. Additional comparison of such data to 2‐D gel analyses and their identified proteins may elucidate the functions of the individual apolipoprotein components and the cardioprotective effects of HDL.
An integrated method for mutation detection using on‐chip sample preparation, single‐stranded conformation polymorphism, and heteroduplex analysis
Authors: Vahedi Golnaz , Kaler Karan , Backhouse Christopher J. 
Published: July 2004

AbstractThis work integrates rapid techniques for mutation detection by producing single‐stranded DNA and (renatured) double‐stranded DNA on‐chip, labeling these with fluorescent DNA stains and then performing two complementary methods of mutation detection‐single stranded conformation polymorphism (SSCP) analysis and heteroduplex analysis (HA). This involves the denaturation of double‐stranded polymerase chain reaction (PCR) product into single‐stranded DNA, the mutation analysis of the single‐stranded DNA by SSCP and the rehybridized double‐stranded DNA by HA. These steps were performed entirely on‐chip within several minutes of operation. The combination of these two mutation detection methods on‐chip provides a highly sensitive method of mutation detection for either genotyping or screening. Many mutation analysis methods rely upon fluorescently labeled samples from a PCR with fluorescently labeled primers. By labeling on‐chip we not only attain improved signal strength, but the method is considerably more versatile. Although we used PCR products in this work, this method could be used to analyze DNA from any source. We believe that this combination of several procedures on a single chip represents a significant step in the development of higher levels of integration upon microfluidic devices.
Sensitive and simultaneous analysis of five transgenic maizes using multiplex polymerase chain reaction, capillary gel electrophoresis, and laser‐induced fluorescence
Authors: García‐Cañas Virginia , González Ramón , Cifuentes Alejandro 
Published: July 2004

AbstractThe benefits of using multiplex polymerase chain reaction (PCR) followed by capillary gel electrophoresis with laser‐induced fluorescence (CGE‐LIF) for the simultaneous detection of five transgenic maizes (Bt11, T25, MON810, GA21, and Bt176) are demonstrated. The method uses a hexaplex PCR protocol to amplify the five mentioned transgenic amplicons plus the zein gene used as reference, followed by a CGE‐LIF method to analyze the six DNA fragments. CGE‐LIF was demonstrated very useful and informative for optimizing multiplex PCR parameters such as time extension, PCR buffer concentration and primers concentration. The method developed is highly sensitive and allows the simultaneous detection in a single run of percentages of transgenic maize as low as 0.054% of Bt11, 0.057% of T25, 0.036% of MON810, 0.064% of GA21, and 0.018% of Bt176 in flour obtaining signals still far from the detection limit (namely, the signal/noise ratios for the corresponding DNA peaks were 41, 124, 98, 250, 252, and 473, respectively). These percentages are well below the minimum threshold marked by the European Regulation for transgenic food labeling (i.e., 0.5–0.9%). A study on the reproducibility of the multiplex PCR‐CGE‐LIF procedure was also performed. Thus, values of RSD lower than 0.67 and 6.80% were obtained for migration times and corrected peak areas, respectively, for the same sample and three different days (n = 12). On the other hand, the reproducibility of the whole procedure, including four different multiplex PCR amplifications, was determined to be better than 0.66 and 23.3% for migration times and corrected peak areas, respectively. Agarose gel electrophoresis (AGE) and CGE‐LIF were compared in terms of resolution and sensitivity for detecting PCR products, demonstrating that CGE‐LIF can solve false positives induced by artifacts from the multiplex PCR reaction that could not be addressed by AGE. Moreover, CGE‐LIF provides better resolution and sensitivity. To our knowledge, these results demonstrate for the first time that multiplex PCR‐CGE‐LIF is a solid alternative to determine multiple genetically modified organisms in maize flours in a single run.
Factorial structure of the Sociocultural Attitudes Towards Appearance Questionnaire among Italian and Australian girls
Authors: Bagnara Sabina , Huon Gail , Donazzolo Sabina 
Published: July 2004

AbstractThis study compared the factorial structure of the self‐report inventory SATAQ (Sociocultural Attitudes Towards Appearance Questionnnaire) (Heinberg, Thompson, & Stormer, 1995) when administered to two samples of girls, one in Italy and a second in Australia. The measure was translated into Italian and its back‐translation carefully checked to ensure equivalence of meaning. Participants were 172 Australian and 171 Italian female undergraduate students. Their responses were scored according to the authors' instructions. Following Heinberg et al. (1995), a principal components factor analysis with promax oblique rotation was conducted. A two‐factor solution that essentially replicates that of Heinberg et al. was produced for the Australian data. However, a more clearly interpretable solution for the Italian responses involved three factors. We discuss the significance of the findings in terms of the utility of the instrument for research and for clinical intervention. Copyright © 2004 John Wiley & Sons, Ltd and Eating Disorders Association.
Relations between aerodynamic and surface roughness in a hyper‐arid cold desert: McMurdo Dry Valleys, Antarctica
Authors: Lancaster Nicholas 
Published: July 2004

AbstractStudies of boundary‐layer winds and surface roughness characteristics of unvegetated rocky desert surfaces provide new insights into the relations between aerodynamic roughness and surface roughness, as described by the roughness density (λ). The description of non‐erodible roughness by the roughness density (λ) is shown to be valid for rocky surfaces as well as sparsely vegetated surfaces and simulated surfaces in a wind tunnel. There is a good relation (r2 = 0·71) between aerodynamic roughness and roughness density (λ), allowing use of the threshold friction velocity ratio to predict sediment transport rates on these surfaces. Copyright © 2004 John Wiley & Sons, Ltd.
Numerical calculations of erosion in an abrupt pipe contraction of different contraction ratios
Authors: Habib M. A. , Badr H. M. , Ben‐Mansour R. , Said S. A. M. 
Published: July 2004

AbstractErosion predictions in a pipe with abrupt contraction of different contraction ratios for the special case of two‐phase (liquid and solid) turbulent flow with low particle concentration are presented. A mathematical model based on the time‐averaged governing equations of 2‐D axi‐symmetric turbulent flow is used for the calculations of the fluid velocity field (continuous phase). The particle‐tracking model of the solid particles is based on the solution of the governing equation of each particle motion taking into consideration the effect of particle rebound behaviour. Models of erosion were used to predict the erosion rate in mg/g. The effect of Reynolds number and flow direction with respect to the gravity was investigated for three contraction geometries considering water flow in a carbon steel pipe. The results show that the influence of the contraction ratio on local erosion is very significant. However, this influence becomes insignificant when the average erosion rates over the sudden contraction area are considered. The results also indicate the significant influence of inlet velocity variations. The influence of buoyancy is significant for the cases of low velocity of the continuous flow. A threshold velocity below which erosion may be neglected was indicated. Copyright © 2004 John Wiley & Sons, Ltd.
A γ‐model BGK scheme for compressible multifluids
Authors: Jiang Song , Ni Guoxi 
Published: July 2004

AbstractWe present a γ‐model BGK scheme for the numerical simulation of compressible multifluids. The scheme is based on the incorporation of a conservative γ‐model scheme given in (J. Comput. Phys. 1996; 125:150–160) into the gas kinetic BGK scheme (J. Comput. Phys. 1993; 109:53–66, J. Comput. Phys. 1994; 114:9–17), and is simple to implement. Several numerical examples presented in this paper validate the scheme in the application of compressible multimaterial flows. Copyright © 2004 John Wiley & Sons, Ltd.
Numerical study of physiological turbulent flows through series arterial stenoses
Authors: Lee T. S. , Liao Wei , Low H. T. 
Published: July 2004

AbstractA numerical investigation on the characteristics of transitional turbulent flow over series bell‐shape stenoses for a physiological pulsatile flow is presented in the present study. The flow behaviours for the physiological pulsatile flow are studied by considering the effects of the Reynolds number, Womersley number, constriction ratio and spacing ratio of the stenoses on the pulsatile turbulent flow fields. Especially, the mutual influences between the double stenoses under different flow conditions are considered. The numerical results show that the variation of these flow parameters puts significant impacts on the flow developments in the arteries with series stenoses. The double stenoses lead to the higher peak turbulence disturbance and the greater area with comparatively high turbulence intensity distal to the stenoses in comparison with the single stenosis. The analysis shows that for the physiological pulsatile flow, the downstream stenosis usually does not have perceptible influences on the upstream flow fields. Copyright © 2004 John Wiley & Sons, Ltd.
A finite element model for the simulation of lost foam casting
Authors: Houzeaux G. , Codina R. 
Published: July 2004

AbstractIn this paper, we present a numerical model to simulate the lost foam casting process. We introduce this particular casting first in order to capture the different physical processes in play during a casting. We briefly comment on the possible physical and numerical models used to envisage the numerical simulation. Next we present a model which aims to solve ‘part of’ the complexities of the casting, together with a simple energy budget that enables us to obtain an equation for the velocity of the metal front advance. Once the physical model is established we develop a finite element method to solve the governing equations. The numerical and physical methodologies are then validated through the solution of a two‐ and a three‐dimensional example. Finally, we discuss briefly some possible improvements of the numerical model in order to capture more physical phenomena. Copyright © 2004 John Wiley & Sons, Ltd.
Efficient temporally controlled targeted somatic mutagenesis in hepatocytes of the mouse
Authors: Schuler Michael , Dierich Andrée , Chambon Pierre , Metzger Daniel 
Published: July 2004

AbstractTo generate temporally controlled targeted somatic mutations selectively and efficiently in hepatocytes, we established SA+/CreERT2 mice in which the tamoxifen‐dependent Cre‐ERT2 recombinase coding sequence preceded by an internal ribosomal entry site was inserted in the 3′ untranslated region of the serum albumin (SA) gene. Whereas the wildtype SA allele was strongly expressed in the liver and at lower levels in some extrahepatic tissues, SA‐Cre‐ERT2 fusion transcripts were only detected in the liver. The Cre‐ERT2 protein was expressed in most if not all hepatocytes, and tamoxifen (Tam) treatments of adult mice at various ages efficiently induced Cre‐mediated recombination of LoxP flanked (floxed) alleles in these cells, but none in other cell types or tissues. Thus, SA+/CreERT2 mice should be of great value to analyze gene function in the liver and to establish animal models of human diseases. genesis 39:167–172, 2004. © 2004 Wiley‐Liss, Inc.
Transgenic mice that express Cre recombinase in osteoclasts
Authors: Chiu W.S.M. , McManus J.F. , Notini A.J. , Cassady A.I. , Zajac J.D. , Davey R.A. 
Published: July 2004

AbstractTo study the physiological control of osteoclasts, the bone resorbing cells, we generated transgenic mice carrying the Cre recombinase gene driven by either the tartrate‐resistant acid phosphatase (TRAP) or cathepsin K (Ctsk) promoters. TRAP‐Cre and Ctsk‐Cre transgenic mouse lines were characterized by breeding with LacZ ROSA 26 (R26R) reporter mice and immunohistochemistry for Cre recombinase. The Cre transgene was functional in all lines, with Cre‐mediated recombination occurring primarily in the long bones, vertebrae, ribs, and calvaria. Histological analyses of the bones demonstrated that functional Cre protein was present in 1) osteoclasts (Ctsk‐Cre); 2) osteoclasts, columnar proliferating, and hypertrophic chondrocytes (TRAP‐Cre line 4); and 3) round proliferating chondrocytes (TRAP‐Cre line 3). In conclusion, we generated transgenic mouse lines that will enable the deletion of floxed target genes in osteoclasts, which will be valuable tools for studying the regulation of osteoclast function. genesis 39:178–185, 2004. © 2004 Wiley‐Liss, Inc.