bluuebunny/crossref_metadata_2025_split huggingface dataset:
New strategy for the determination of gliadins in maize‐ or rice‐based foods matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry: fractionation of gliadins from maize or rice prolamins by acidic treatment
Authors: Hernando Alberto , Valdes Israel , Méndez Enrique 
Published: August 2003

AbstractA procedure for determining small quantities of gliadins by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) in gluten‐free foods containing relatively large amounts of prolamin proteins from maize or rice is described. We report for the first time that gliadins, the ethanol‐soluble wheat prolamin fraction, can be quantitatively solubilized in 1.0 M acetic acid, while the corresponding ethanol‐soluble maize or rice prolamin fraction remains insoluble in acetic acid. We describe a methodology for the detection of gliadins in maize and rice foods based on a two‐step procedure of extraction (60% aqueous ethanol followed by 1 M acetic acid). Subsequent MALDI‐TOFMS analysis of the resulting acidic extract from these gluten‐free foods clearly confirms the presence of a typical mass pattern corresponding to gliadin components, ranging from 30 to 45 kDa. Depending on the percentages of maize or rice flours employed in the elaboration of these foods, the combined procedure enables levels of gliadins from 100 to 400 ppm to be detected. The efficiency of this combined procedure corroborates enzyme‐linked immunosorbent assay data for a large number of maize/rice gluten‐free foods by means of direct visualization of the characteristic gliadin mass pattern in maize or rice foods. Copyright © 2003 John Wiley & Sons, Ltd.
Separation of 11 protease and reverse transcriptase inhibitors by capillary zone electrophoresis
Authors: Gutleben Wolfgang , Scherer Karin , Tuan Nguyen Duc , Stoiber Heribert , Dierich Manfred P. , Zemann Andreas 
Published: August 2003

AbstractCapillary zone electrophoresis is employed for the simultaneous screening of protease and reverse transcriptase inhibitors which are used as antiretroviral therapy drugs against the Human Immunodeficiency Virus. Because of the basic character of the analytes, the electrophoretic system makes use of an acidic buffer electrolyte. In order to establish a strong anodic electroosmotic flow, a cationic surfactant is added to the background electrolyte. This causes the cationic analytes to migrate against the electroosmotic stream (counter‐electroosmotic CE). The developed separation system permits a simultaneous separation of protease and reverse transcriptase inhibitors with good selectivity and sensitivity.
Quantitative determination of rutin, quercetin, and adenosine in Flos Carthami by capillary electrophoresis
Authors: Sun Yi , Guo Tao , Sui Yin , Li Famei 
Published: August 2003

AbstractA capillary electrophoresis method was developed for the separation and determination of adenosine, rutin, and quercetin in Flos Carthami. The CE separation was achieved using 50 mmol L–1 sodium tetraborate solution (pH 9.7) containing 18% methanol as the running buffer, with an applied voltage of 24 kV and detection at 210 nm. The contents of these constituents in an ethanol‐water extract of Flos Carthami could be easily determined within 45 min. The RSDs of the contents of these constituents were within 5.2% (n = 5). The contents of adenosine, rutin, and quercetin were determined in Flos Carthami from ten sources. Differences in contents were observed between various sources, which may be attributed to the growth environment of the plant, the time of harvesting, the storage conditions, and the drying process. The current method may serve as a valuable tool for the quality control of Flos Carthami.
Capillary electrophoresis profiles of fucoidan and heparin fractions: significance of mobility dispersity for their characterization
Authors: Kim Moo Young , Varenne Anne , Daniel Régis , Gareil Pierre 
Published: August 2003

AbstractCapillary electrophoresis was investigated for characterization of the natural anionic polysaccharide fucoidan from marine brown algae and its comparison with heparin under different pH, ionic strength, and counter‐ion conditions. Reproducible profiles of these polysaccharides were obtained in indirect UV detection mode by introducing sulfosalicylic acid or anisic acid as chromophores in background electrolytes. Theoretical evaluations of zone spreading originating from molecular diffusion, electromigration, and initial zone width have shown that these dispersive contributions remain negligible compared to the overall profile dispersion. Therefore, the conversion of the experimental electropherograms (absorbance vs. time plots) into absorbance vs. electrophoretic mobility curves enables a comparison of these polysaccharides in terms of electrophoretic mobility dispersity. Nevertheless, a linear correlation between mobility and chemical charge rate cannot be established for these highly sulfated polysaccharides, because their chemical charge rate is higher than the threshold value for which counter‐ion condensation occurs.
A portable multi‐dimensional gas chromatographic system for field applications
Authors: Wahl Jon H. , Riechers Douglas M. , Vucelick Mark E. , Wright Bob W. 
Published: August 2003

AbstractWe have constructed and tested a multi‐dimensional gas chromatographic system that can be utilized for field portable applications. The chromatographic system is capable of one‐dimensional separations and multi‐dimensional gas chromatographic (MDGC) separations in a single compact package. Three different general multi‐dimensional separation approaches are possible: column switching; traditional heart‐cutting; and comprehensive analyses. The MDGC system utilizes a simple 10‐port valving approach to accomplish these separations to a single point detector. Because of this valving scheme no hardware change is required to switch between the heart‐cut and the comprehensive separation modes, only a software methodology change is required. An additional advantage of this valving approach is that 100% of the first‐dimensional effluent is sampled to the second dimension for separation. The system is capable of rapid column heating (room temperature to 250°C in approximately 10 s) and rapid column cooling (250°C to room temperature within approximately 30 s). Preliminary results for heart‐cut and comprehensive separations that target five compounds against high concentration levels of complex background are illustrated.
Performance of three chemically‐ modified silica materials for solid phase extraction of polar compounds from aqueous solutions
Authors: Pizzolato Tânia Mara , Foschiera José Luis , Benvenutti Edilson , Gomes Fabiana , Geller Ana Maria , Lopes Adriana , do Carmo Ruaro Peralba Maria , dos Santos João H. Z. 
Published: August 2003

AbstractSilica gel (320 m2g–1, 10 nm) was chemically modified with 3‐chloropropyltrimethoxysilane or 3‐aminopropyltrimethoxysilane, followed by reaction with aniline, 3‐phenylchloropropylamine, or benzylamine. The resulting silicas were characterized by elemental analysis and spectroscopic techniques, namely diffuse reflectance spectroscopy (DRS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and 29Si variable amplitude cross‐polarization magic‐angle spin nuclear magnetic resonance (VACP‐MAS‐NMR). The resulting solids were shown to be stable in aqueous and non‐aqueous media and were tested as sorbents for pre‐concentration of derivatized phenolic compounds (acetyl derivatives of: phenol, o‐cresol, m‐cresol, p‐cresol, 2‐ethylphenol, 3‐ethylphenol, and 4‐ethylphenol) and some organochloride pesticides (endrin, pentachlorobenzene, heptachloro epoxide, hexachlorobenzene, and lindane) in aqueous media. Extractionexperiments were undertaken using a precleaned cartridge (10 cm×10 mm ID) packed with modified silica gel and with commercial C‐18 in order to evaluate the influence of the nature of the functional group onretention of the compounds under study. Results showed that silica modified with aniline gave the highest retention for the studied acetylated phenolic compounds. Silica modified with 3‐phenylchloropropyl groups exhibited the highest retention for hexachlorobenzene and aldrin, while that modified with benzylamine showed the highest retentionfor eldrin, pentachlorobenzene, and heptachloro epoxide. Lindane was not retained by any of the tested materials.
Non‐specific retention characteristics of dissolved β‐cyclodextrin derivatives in open tubular column gas chromatography
Authors: Kiridena Waruna , Poole Colin F. , Nawas Mohamed I. , Koziol Wladyslaw W. 
Published: August 2003

AbstractThe solvation parameter model is used to identify contributions from intermolecular interactions responsible for non‐specific retention in gas chromatography for three dissolved β‐cyclodextrin derivatives in a poly(cyanopropylphenyldimethylsiloxane) stationary phase. The cyclodextrins are permethylated β‐cyclodextrin (Cyclodex‐B), heptakis(2,3‐di‐O‐methyl‐6‐O‐t‐butyldimethylsilyl)‐β‐cyclodextrin (CycloSil‐B) and heptakis(2,3‐di‐O‐acetoxy‐6‐O‐t‐butyldimethylsilyl)‐β‐cyclodextrin (Rt‐βDEXsa). Taking DB‐1701 as a reference phase for the poly(cyanopropylphenyldimethylsiloxane) solvent, it is shown that the dominant interactions for the cyclodextrin derivatives are associated with their hydrogen‐bond basicity and capacity for dipole‐type interactions. None of the cyclodextrin derivatives are hydrogen‐bond acids and all are weakly electron lone pair repulsive. The cohesive properties of the dissolved phases are similar to those of the solvent, except for Rt‐βDEXsa, which is significantly more cohesive. Also, Rt‐βDEXsa shows significant inclusion complexation for the compounds used to determine the system constants of the solvation parameter model resulting in poor statistical models, suitable only for qualitative interpretation. The Cyclodex‐B and CycloSil‐B columns are compared to a database of 23 open‐tubular column stationary phases possessing similar selectivity to each other but different selectivity for non‐specific interactions to the other stationary phase types.
Evaluation of denaturing conditions in analysis of DNA variants applied to multi‐capillary electrophoresis instruments
Authors: Bjørheim Jens , Minarik Marek , Gaudernack Gustav , Ekstrøm Per Olaf 
Published: August 2003

AbstractDenaturant slab gel techniques (DGGE and variants thereof) and denaturing CE (DCE) have been used for the analysis of mutations and single nucleotide polymorphisms by several research groups. Recently, DCE applied to commercially available capillary electrophoresis instruments has been demonstrated to be sensitive, specific, and robust for mutation and SNP analysis. However, instruments currently available on the market are not designed for DCE in their present forms. In both single and multi‐capillary instruments inaccurate temperature control units lead to irreproducible denaturing conditions, both between runs and from capillary to capillary within an electrophoresis run. We have previously suggested that cycling a temperature gradient several times around a theoretically defined optimum for a given DNA fragment results in more reproducible and controllable denaturing conditions compared to a constant denaturant or single sweep temperature gradient. In this paper, we demonstrate that with the temperature differences observed, the common technique of applying a temperature gradient is not sufficient for optimal separation conditions in all capillaries. Furthermore, we demonstrate that cycling of the temperature around a fragment's theoretically calculated melting temperature during electrophoresis leads to reproducible results in all capillaries. These results clearly show the potential of standard commercial capillary instruments in automated cycling temperature CE applications.
Direct resolution of novel tetrahedral metal clusters on a cellulose tris‐(3,5‐dimethylphenylcarbamate) chiral stationary phase by high‐performance liquid chromatography
Authors: Zhu Xinyi , Cai Yingchun , Zhang Weiqiang , Chen Liren , Li Yongmin 
Published: August 2003

AbstractDirect optical resolution of five novel tetrahedral heterometal cluster enantiomers has been achieved for the first time on a cellulose tris‐(3,5‐dimethylphenylcarbamate) chiral stationary phase, using hexane as the mobile phase with various alcohols as modifiers. UV detection was carried out at 254 nm. The influence of the mobile phase composition on enantioselectivity is discussed and optimum resolution has been achieved. The effect of structural variation of the solutes on their enantioseparation has also been investigated.
Determination of pharmaceutical process impurities by solid phase microextraction gas chromatography
Authors: Frost Richard P. , Hussain Mumtaz S. , Raghani Anil R. 
Published: August 2003

AbstractA methodology for automated headspace solid‐phase microextraction for the trace analysis of pharmaceutical process‐related toxic impurities such as benzyl chloride, triethyl amine, chloroethyl methyl ether, N‐methylmorpholine, and N‐methylpyrrolidinone by gas chromatography and flame ionization detection is reported. Carboxen/polysiloxane/divinylbenzene fiber showed excellent sensitivity towards these analytes compared to direct injection and the highest sensitivity among the commercial SPME fibers evaluated in this study. However, a profound effect of competition for the available adsorption sites was observed on the Carboxen/PDMS/DVB fiber. The effects of extraction parameters such as extraction time, temperature, agitation rate, and headspace volume were studied. The influence of the addition of inorganic salt on the analyte extraction efficiency was also investigated. The sensitivity of method extended to the sub‐ppm level with acceptable precision and accuracy. The linearity of the method covered one order of magnitude. The narrower linear dynamic range is attributed largely to the limited number of adsorption sites on the Carboxen/PDMS/DVB fiber.
Large volume injection GC‐MS in electron capture negative ion mode utilizing isotopic dilution for the determination of polybrominated diphenyl ethers in air
Authors: Björklund Jonas , Tollbäck Petter , Östman Conny 
Published: August 2003

AbstractA large volume injection GC‐MS method for the determination of polybrominated diphenyl ethers (PBDEs) is presented. A loop‐type injection system with an early solvent vapor exit has been constructed and evaluated. With this system sample volumes up to 500 μL could be injected with high reproducibility and low carry‐over. The peak distortion problem associated with this kind of injection system is discussed in detail and solutions are suggested. We also introduce 13C‐labeled BDE‐209 as internal surrogate standard for the determination of high molecular weight PBDEs in low‐resolution mass spectrometry electron capture negative ionization mode. The complete method has been applied to air samples from an electronic waste dismantling facility, collected with personal exposure measurement equipment. Nine BDE congeners have been identified and quantified.
The relevance of MCDM for financial decisions
Authors: Hallerbach Winfried G. , Spronk Jaap 
Published: August 2003

AbstractFor people working in finance, either in academia or in practice or in both, the combination of ‘finance’ and ‘multiple criteria’ is not obvious. However, we believe that many of the tools developed in the field of MCDM can contribute both to the quality of the financial economic decision making process and to the quality of the resulting decisions. In this paper we answer the question why financial decision problems should be considered as multiple criteria decision problems and should be treated accordingly. Copyright © 2003 John Wiley & Sons, Ltd.
Evolving economy bank asset‐liability and risk management under uncertainty with hierarchical objectives and nonlinear pricing
Authors: Dash Gordon H. , Kajiji Nina 
Published: August 2003

AbstractQuantitative modelling of the asset‐liability management (ALM) problem faced by banking institutions is reexamined in this paper. The model presented here joins stochastic programming with non‐linear goal programming (SNGP). A bank optimization model with multiple objectives, multiple non‐linear economic relationships and a complex options hedge is proposed as an extension to the contemporary model structure now used by most financial institutions. The model structure is particularly well suited to solve the ALM decision problem in evolving economies where shareholder value maximization is often stated across a multiple goal hierarchy. The result of solving the SNGP provided significant evidence that the method is viable for efficient bank management under quasi‐planned economics. Stating the non‐linear demand and supply relationships within the two‐stage representation of the stochastic decision environment proved to be an effective method for resolving complex pricing policy issues. Finally, the SNGP model extends prior ALM models by simultaneously hedging interest rate risk under uncertainty through the incorporation of a complex chooser option. The complex chooser option, a hedge with a known pay‐off, was chosen to assist an inexperienced management team with an effective risk‐abatement tool. Copyright © 2003 John Wiley & Sons, Ltd.
A multi‐criterion approach for selecting attractive portfolio
Authors: Bouri A. , Martel J. M. , Chabchoub H. 
Published: August 2003

AbstractAccording to the conventional theory of finance, maximizing return with minimum risk should be a hallmark of every successful investor. However, contrary to the theoretical expectations of the conventional theory, the tests achieved on most financial markets have revealed the existence of other variables. Morever, behavioural aspects, like the investor's attitude to solvency and liquidity, are not taken into consideration. Then the problem of selecting an attractive portfolio is a multi‐criteria issue which should be tackled by using the appropriate techniques. A Multicriterion approach is proposed and applied to the Tunisian Stock Market to select an attractive portfolio. Copyright © 2003 John Wiley & Sons, Ltd.
On the use of a multi‐criteria hierarchical discrimination approach for country risk assessment
Authors: Doumpos M. , Zopounidis C. 
Published: August 2003

AbstractCountry risk is an issue with multidimensional implications in economic and social development at the national, regional and global levels. The assessment of country risk is often realized as a classification problem, involving the assignment of the countries into predefined groups according to their economic prospects. Within this framework, this study employs the MHDIS multi‐criteria decision aid method (Multi‐group Hierarchical DIScrimination) for developing country risk assessment models. The data used in the analysis involve a set of 161 countries obtained from the World Bank. An extensive comparison is also performed with other well‐known parametric and non‐parametric classification methods. Copyright © 2003 John Wiley & Sons, Ltd.
Identification of biologic markers of the premature rupture of fetal membranes: Proteomic approach
Authors: Vuadens Françoise , Benay Corinne , Crettaz David , Gallot Denis , Sapin Vincent , Schneider Philippe , Bienvenut Willy‐Vincent , Lémery Didier , Quadroni Manfredo , Dastugue Bernard , Tissot Jean‐Daniel 
Published: August 2003

AbstractIn obstetrics, premature rupture of the membranes (PROM) is a frequent observation which is responsible for many premature deliveries. PROM is also associated with an increased risk of fetal and maternal infections. Early diagnosis is mandatory in order to decrease such complications. Despite that current biological tests allowing the diagnosis of PROM are both sensitive and specific, contamination of the samples by maternal blood can induce false positive results. Therefore, in order to identify new potential markers of PROM (present only in amniotic blood, and absent in maternal blood), proteomic studies were undertaken on samples collected from six women at terms (pairs of maternal plasma and amniotic fluid) as well as on four samples of amniotic fluid collected from other women at the 17th week of gestation. All samples (N = 16) were analyzed by two‐dimensional (2‐D) high‐resolution electrophoresis, followed by sensitive silver staining. The gel images were studied using bioinformatic tools. Analyses were focused on regions corresponding to pI between 4.5 and 7 and to molecular masses between 20 and 50 kDa. In this area, 646 ± 113 spots were detected, and 27 spots appeared to be present on the gels of amniotic fluid, but were absent on those of maternal plasma. Nine out of these 27 spots were also observed on the gels of the four samples of amniotic fluids collected at the 17th week of pregnancy. Five of these 9 spots were unambiguously detected on preparative 2‐D gels stained by Coomassie blue, and were identified by mass spectrometry analyses. Three spots corresponded to fragments of plasma proteins, and 2 appeared to be fragments of proteins not known to be present in plasma. These 2 proteins were agrin (SWISS‐PROT: O00468) and perlecan (SWISS‐PROT: P98160). Our results show that proteomics is a valuable approach to identify new potential biological markers for future PROM diagnosis.
Proteomics application exercise of the Swiss Proteomics Society: Report of the SPS'02 session
Authors: Binz Pierre‐Alain , Abdi Fadi , Affolter Michael , Allard Laure , Barblan Jachen , Bhardwaj Sanjeev , Bienvenut Willy V. , Bulet Philippe , Burgess Jennifer , Carrette Odile , Corthals Garry , Delalande François , Diemer Hélène , Favreau Philippe , Giuliano Elia , Gueguen Yannick , Guillaume Elisabeth , Hahner Stephanie , Man Petr , Michalet Sophie , Neri Dario , Noukakis Dimitrios , Palagi Patricia , Paroutaud Pierre , Carvalho Pimenta Daniel , Quadroni Manfredo , Resemann Anja , Richert Sophie , Rybak Jascha , Sanchez Jean‐Charles , Scherl Alexander , Scheurer Simone , Schweiger Hufnagel Ulrike , Siethoff Christoph , Suckau Detlev , van Dorsselaer Alain , Wagner Redeker Winfried , Walter Nadia , Stöcklin Reto 
Published: August 2003

AbstractAfter the success of the mass spectrometry (MS) round table that was held at the first Swiss Proteomics Society congress (SPS'01) in Geneva, the SPS has organized a proteomics application exercise and allocated a full session at the SPS'02 congress. The main objective was to encourage the exchange of expertise in protein identification, with a focus on the use of mass spectrometry, and to create a bridge between the users’ questions and the instrument providers’ solutions. Two samples were sent to fifteen interested labs, including academic groups and MS hardware providers. Participants were asked to identify and partially characterize the samples. They consisted of a complex mixture of peptide/proteins (sample A) and an almost pure recombinant peptide carrying post‐translational modifications (sample B). Sample A was an extract of snake venom from the species Bothrops jararaca. Sample B was a recombinant and modified peptide derived from the shrimp Penaeus vannamei penaeidin 3a. The eight labs that returned results reported the use of a wide range of MS instrumentation and techniques. They mentioned a variety of time and manpower allocations. The origin of sample A was generally identified together with a number of database protein entries. The difficulty of the sample identification lay in the incomplete knowledge of the Bothrops species genome sequence and is discussed. Sample B was generally and correctly identified as penaeidin. However, only one group reported the full primary structure. Interestingly, the approaches were again varied and are discussed in the text.