bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of solvent on temperature and thermal peak broadening in capillary zone electrophoresis
Authors: Porras Simo P. , Marziali Ettore , Gaš Bohuslav , Kenndler Ernst 
Published: May 2003

AbstractThe present paper deals with the role of the solvent on thermal peak broadening. One main solvent property that determines the magnitude of the temperature gradient due to the generation of Joule heat in capillary zone electrophoresis is the thermal conductivity. As organic solvents have lower thermal conductivity than water (methanol and acetonitrile, e.g., nearly by a factor of 3) it can be hypothesized that the temperature gradient inside the capillary is more pronounced in organic solvents compared to an aqueous solution. On the other hand, the temperature dependence of the ion mobility (which is responsible for the velocity profile and thus for thermal peak broadening) is smaller in organic solvents. To get insight into the thermal effect of the solvent, first the temperature of a solution in a cylindrical tube was calculated utilizing the heat balance equation. It was shown that the two theoretical models most common in the literature (based on the analytical solution or on an assumption of the parabolic temperature profile in the tube, respectively) give the same results. The latter model was chosen for the further calculations, adding a quadratic term to express the electric conductivity as a function of the temperature. The temperature at the inner capillary wall and center as function of the capillary dimensions and the electric power was computed for electrolytes with a given conductivity at 25.0°C with water, methanol, and acetonitrile as solvents. Capillary cooling systems used were circulating liquid cooling, enforced air‐cooling, and natural convection in still air. The mean temperature (averaged over the cross section) resulting from Joule heating was compared with experimentally determined temperatures established upon application of an electric field; the latter temperature was derived from the measurement of the electric conductance of the background electrolyte solution and its (measured) temperature dependence. All investigations were carried out with solutions of the same initial electric conductivity (about 0.5 S·m−1 at 25.0°C). Agreement is found for natural convection conditions, and the deviation between theoretical and experimental results for the forced air and circulated liquid cooling systems can be related to the poorly defined thermal conditions of the capillaries in commercial instrumentation (with a part in a thermostated cassette and a part outside). For given conditions the temperature gradients in the organic solvents exceed largely those in water, independent of the type of cooling. As a consequence, the thermal plate height is significantly larger in organic solvents, at least under conditions where the deviation from the Nernst‐Einstein limiting case is not too high. However, even for the maximum applicable field strengths the thermal plate height contributions are negligible compared to longitudinal diffusion in all solvents.
Separation of (Z)‐ and (E)‐isomers of thioxanthene and dibenz[b,e]oxepin derivatives with calixarenes and resorcinarenes as additives in nonaqueous capillary electrophoresis
Authors: Sokoließ Torsten , Gronau Michael , Menyes Ulf , Roth Ullrich , Jira Thomas 
Published: May 2003

AbstractFive acidic calix[4]arenes with carboxylic or sulfonic groups at either the upper or lower rim of the cavity and one resorc[4]arene were investigated to separate three thioxanthenes (flupentixol, clopenthixol, chlorprothixene) and a dibenz[b,e]oxepin derivative (doxepin) with cis‐/trans‐isomerism by nonaqueous capillary electrophoresis (NACE). Partial filling of the capillary with the UV‐absorbing selectors led to a low detection limit and an advantageous signal‐to‐noise ratio (S/N). A sufficient electrophoretic mobility of the calixarenes towards the anode was necessary to outweigh the oppositely directed electroosmotic flow (EOF). This depended from the functional groups, the dissociation and the hydrodynamic radius of the cyclophanes. In contrast, the resorcinarene was useable only by addition of sodium dodecyl sulfate (SDS) because only the complex of the two selectors had an anodic apparent electrophoretic mobility. p‐Sulfonyl‐calix[4]arene (ss‐a1) was the most capable selector for all E/Z‐isomers with maximal α‐values ranging from 1.056 for doxepin to 1.224 for chlorprothixene. This was due to the sufficient migration in reversed direction to the EOF even at low pH* values of 3.0. Otherwise, electrostatic as well as hydrophobic interactions with the positively charged isomers seem to contribute to a superior recognition. Increasing the concentration up to 15 mM ss‐a1 and using acidic media (pH* 5.0) led to high separation efficiency. Changing the organic solvent provides a powerful tool to improve selectivity with N,N‐dimethylformamide‐methanol (DMF‐MeOH)‐mixtures for thioxanthenes. Further electrophoretic parameters were optimized, such as the concentration of the electrolytes, the addition of SDS, the kind of electrolytes and the voltage. Distinct differences in selectivities were found between the derivatives with thioxanthene and dibenzo[b,e]oxepin ring system, respectively. Further, the different basic side chain was responsible for the different selectivity at higher pH* values. In contrast, the substitution at position 2 of the thioxanthenes played a secondary role. Based on the studies of single parameters a method for a simultaneous separation of the four pairs of isomers within 13 min was developed.
Capillary electrophoresis of cardiolipin with on‐line dye interaction and spectrophotometric detection
Authors: Qi Lining , Danielson Neil D. , Dai Qiang , Lee Ray M. 
Published: May 2003

AbstractCardiolipin is an important phospholipid present in the mitochondrial inner membrane. It plays a key function in mitochondrial respiration by interacting with many enzymes or cofactors related to oxidative phosphorylation complexes. We have determined the concentration of cardiolipin using on‐line 10‐N‐nonyl acridine orange (NAO) dye interaction capillary electrophoresis (CE) and spectrophotometric detection with a sample throughput of 3 min. In addition to the presence of 0.1 mM NAO, the background electrolyte (BGE) composition has been set at 80% methanol‐10% acetonitrile‐10% H2O (all v/v) to provide both good solubility and the maximum absorbance enhancement at 497 nm for the NAO‐cardiolipin complex as compared to NAO alone. Sample consumption for each injection is about 57 nL. A calibration curve is established from 0.5 μM to 0.1 mM with R 2 = 0.9912 with a detection limit of 0.05 μM for cardiolipin. In a blind study, actual mitochondrial cell membrane samples in the μL range before or after UV light exposure were analyzed using the CE method. Cardiolipin concentration decreased in the different parts of the membrane sample upon UV photolysis of the cells. Support for the theory that UV light can induce cardiolipin translocation from the inner membrane (IM) to the outer membrane (OM) was indicated by a significant percentage increase of cardiolipin (as measured by the cardiolipin in the OM as compared to the sum total in the OM and IM) from 30.7 ± 2.4% before UV light photolysis to 38.3 ± 2.2% after UV irradiation.
Cumulative risk assessment for quantitative response data
Authors: Chen James J. , Chen Yi‐Ju , Teuschler Linda K. , Rice Glenn , Hamernik Karen , Protzel Alberto , Kodell Ralph L. 
Published: May 2003

AbstractThe Relative Potency Factor approach (RPF) is used to normalize and combine different toxic potencies among a group of chemicals selected for cumulative risk assessment. The RPF method assumes that the slopes of the dose–response functions are all equal; but this method depends on the choice of the index chemical, i.e. different index chemicals will give different predicted mean estimates. This article is part of an approach to explore and develop cumulative risk assessment strategies. As part of this approach this article proposes a procedure for cumulative risk assessment from exposure to multiple chemicals that have a common mechanism of toxicity. We propose two classification algorithms to cluster the chemicals into subclasses such that the chemicals in the same subclass have a common slope. The joint response is estimated by fitting the dose–response model of the mixture under dose addition. The proposed method will give the same predicted mean response regardless of the selection of the index chemical for the chemicals in the same subclass. The proposed method also allows one to estimate the joint response for chemicals having different slopes. An example data set of six hypothetical pesticide chemicals is used to illustrate the proposed procedure. Copyright © 2003 John Wiley & Sons, Ltd.
Bayesian uncertainty assessment in multicompartment deterministic simulation models for environmental risk assessment
Authors: Bates Samantha C. , Cullen Alison , Raftery Adrian E. 
Published: May 2003

AbstractWe use a special case of Bayesian melding to make inference from deterministic models while accounting for uncertainty in the inputs to the model. The method uses all available information, based on both data and expert knowledge, and extends current methods of ‘uncertainty analysis’ by updating models using available data. We extend the methodology for use with sequential multicompartment models. We present an application of these methods to deterministic models for concentration of polychlorinated biphenyl (PCB) in soil and vegetables. The results are posterior distributions of concentration in soil and vegetables which account for all available evidence and uncertainty. Model uncertainty is not considered. Copyright © 2003 John Wiley & Sons, Ltd.
Evaluation of water quality using acceptance sampling by variables
Authors: Smith Eric P. , Zahran Alyaa , Mahmoud Mahmoud , Ye Keying 
Published: May 2003

AbstractUnder section 303(d) of the Clean Water Act, states must identify water segments where loads of pollutants are violating numeric water quality standards. Consequences of misidentification are quite important. A decision that water quality is impaired initiates the total maximum daily load or TMDL planning requirement. Falsely concluding that a water segment is impaired results in unnecessary TMDL planning and pollution control implementation costs. On the other hand, falsely concluding that a segment is not impaired may pose a risk to human health or to the services of the aquatic environment. Because of the consequences, a method is desired that minimizes or controls the error rates. The most commonly applied approach is to use the Environmental Protection Agency (EPA)'s raw score approach in which a stream segment is listed as impaired when greater than 10 per cent of the measurements of water quality conditions exceed a numeric criteria. An alternative to the EPA approach is the binomial test that the proportion exceeding the standard is 0.10 or less. This approach uses the number of samples exceeding the criteria as a test statistic along with the binomial distribution for evaluation and estimation of error rates. Both approaches treat measurements as binary; the values either exceed or do not exceed the standard. An alternative approach is to use the actual numerical values to evaluate standard. This method is referred to as variables acceptance sampling in quality control literature. The methods are compared on the basis of error rates.If certain assumptions are met then the variables acceptance method is superior in the sense that the variables acceptance method requires smaller sample sizes to achieve the same error rates as the raw score method or the binomial method. Issues associated with potential problems with environmental measurements and adjustments for their effects are discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Study of the space–time effects in the concentration of airborne pollutants in the Metropolitan Region of Rio de Janeiro
Authors: Paez Marina Silva , Gamerman Dani 
Published: May 2003

AbstractIn this article, we present an application of models with temporal and spatial components, from the Bayesian point of view, on data pollutants collected in 16 different monitoring sites located in the Metropolitan Area of Rio de Janeiro during 1999. All the models considered here assume conditionally independent observations, with a mean specified by the sum of random temporal and spatial components and a linear function of the maximum daily temperature and indicators of the day of the week. Our aim here is to analyze distinct specifications for the components, assuming different kinds of modeling that are not usually compared. The comparison is based on the posterior predictive loss function proposed by Gelfand and Ghosh (1998). The best specifications for the spatial component were the ones which considered a geostatistical approach to its correlation function. The best specification for the temporal component was the stationary autoregressive form. The pollutant concentrations were interpolated in a grid of points in the area of higher population density at a fixed period of time for the selected model. Copyright © 2003 John Wiley & Sons, Ltd.
On some aspects of data integration techniques with environmental applications
Authors: Sinha Bikas K. , Shah Kirti R. 
Published: May 2003

AbstractMultiple Criteria Decision Making (MCDM) is a popular phrase used to describe situations where there is a need for integration of the results of different studies to make an overall judgement. Among the highest priorities towards socioeconiomic development around the world is the Environmental Protection Policy (EPP), and environmental assessment is a key to EPP. In the context of environmental studies, data integration techniques are very appealing and have wider applicability. It is well known that land, air and water are the three sources for determination of the extent of pollution of different regions. The purpose of MCDM is to rank the regions wrt all the sources taken together. For any individual source of pollution, it is trivial to rank the regions from best to worst. However, the problem of integration becomes non‐trivial in most cases since the regions do not lend themselves to the same pattern of ranking wrt different sources. In this article we examine critically the performance of two popular composite indices (CI) and suggest some alternatives. Copyright © 2003 John Wiley & Sons, Ltd.
Incorporation of ARMA models into flow forecasting by artificial neural networks
Authors: Cigizoglu H. K. 
Published: May 2003

AbstractA frequently encountered problem during the application of artificial neural networks (ANNs) to various water resource problems is the limitation of the data sets required for the training stage of ANNs. This prevents ANNs from learning input and output data sets within different ranges, thus decreasing the prediction capability during the testing stage. In this article the well known ARMA models are used to generate synthetic series, and these series are incorporated into the training data sets of ANNs. The method is applied to the monthly mean river flow data of a station in the East Mediterranean region of Turkey. The forecasting accuracy of the future monthly flows carries significance because a water reservoir is planned for the downstream of this station. Because the available data record length is limited studies should be carried out to extend the training data set of ANNs. It is seen that the extension of input and output data sets in the training stage improves the accuracy of forecasting using ANNs. The introduction of periodicity components in the input layer also increases the forecasting accuracy of ANNs. Copyright © 2003 John Wiley & Sons, Ltd.
A study on the incidence of ABL gene deletion on derivative chromosome 9 in chronic myelogenous leukemia by interphase fluorescence in situ hybridization and its association with disease progression
Authors: Lee Dong Soon , Lee Yun‐Song , Yun Yeon‐sook , Kim Young‐Ree , Jeong Seok San , Lee Young Kyung , She Cha Ja , Yoon Sung Soo , Shin Hae Rim , Kim Yongsoo , Cho Han Ik 
Published: May 2003

AbstractFluorescence in situ hybridization for the BCR/ABL rearrangement in 138 bone marrow specimens from 59 Philadelphia+ (Ph+) chronic myelogenous leukemia (CML) patients, 35 Ph+ acute lymphoblastic leukemia (ALL) patients, and 57 Ph− ALL patients was used. Sixteen (27.1%) of the 59 CML patients had deletions of the residual ABL gene on the derivative chromosome 9. During the study period, 32 of the 59 CML patients progressed to blast crisis or accelerated phase. Of these, nine patients had residual ABL gene deletions on the derivative chromosomes 9 and 23 patients had no deletions. The mean duration from first diagnosis to blast crisis or accelerated phase for the nine patients with ABL deletions was 32.8 months, and for the 23 patients without ABL deletions, it was 62.4 months (P = 0.017). The overall survival time for the 16 patients with deletions was 32.8 months, and for the 43 patients without deletions, it was 60.1 months (P = 0.164). ABL deletions were not detected among the 35 ALL patients (17 with major BCR/ABL, 18 with minor BCR/ABL), and it appears that this deletion occurs rarely or not at all in Ph+ ALL patients, which is in contrast to the CML patients (27.1%). However, we detected two ALL cases with ABL deletion but without BCR/ABL rearrangement among 49 Ph− ALL and 66 Ph− AML patients. In conclusion, patients with ABL deletions progress to blast crisis or accelerated phase in a significantly shorter time than do those without such deletions. It is therefore suggested that the ABL deletion is an indicator of a poor prognosis in CML. © 2003 Wiley‐Liss, Inc.
Cytogenetic, spectral karyotyping, fluorescence in situ hybridization, and comparative genomic hybridization characterization of two new secondary leukemia cell lines with 5q deletions, and MYC and MLL amplification
Authors: Knutsen Turid , Pack Svetlana , Petropavlovskaja Maria , Padilla‐Nash Hesed , Knight Clement , Mickley Lyn A. , Ried Thomas , Elwood Patrick C. , Roberts Susan J. 
Published: May 2003

AbstractCytogenetic studies of patients with therapy‐induced acute myeloid leukemia (t‐AML) have demonstrated whole chromosome loss or q‐arm deletion of chromosomes 5 and/or 7 in a majority of cases. We have established two cell lines, SAML‐1 and SAML‐2, from two patients who developed t‐AML after radiation and chemotherapy for Hodgkin disease. In both cases, the leukemia cells contained 5q deletions. SAML‐1 has 58 chromosomes and numerous abnormalities, including der(1)(1qter→1p22::5q31→5qter), der(5)(5pter→5q22::1p22→1pter), +8, der(13)i(13)(q10)del(13)(q11q14.1), and t(10;11). Fluorescence in situ hybridization (FISH) with unique sequence probes for the 5q31 region showed loss of IL4, IL5, IRF1, and IL3, and translocation of IL9, DS5S89, EGR1, and CSFIR to 1p. SAML‐2 has 45 chromosomes, del(5)(q11.2q31) with a t(12;13)ins(12;5), leading to the proximity of IRF1 and RB1, and complex translocations of chromosomes 8 and 11, resulting in amplification of MYC and MLL. Comparative genomic hybridization and spectral karyotyping were consistent with the G‐banding karyotype and FISH analyses. Because a potential tumor suppressor(s) in the 5q31 region has yet to be identified, these cell lines should prove useful in the study of the mechanisms leading to the development of t‐AML. © 2003 Wiley‐Liss, Inc.
Patterns of aneuploidy in stage IV clear cell renal cell carcinoma revealed by comparative genomic hybridization and spectral karyotyping
Authors: Pavlovich Christian P. , Padilla‐Nash Hesed , Wangsa Danny , Nickerson Michael L. , Matrosova Vera , Linehan W. Marston , Ried Thomas , Phillips John L. 
Published: May 2003

AbstractWe report the use of spectral karyotyping (SKY) and comparative genomic hybridization (CGH) to describe the numerous genomic imbalances characteristic of stage IV clear cell renal cell carcinoma (CCRCC). SKY and CGH were performed on 10 cell lines established from nephrectomy specimens, and CGH on uncultured material from five of the primary renal tumors. The mutational status of VHL (3p25) and MET (7q31), genes implicated in renal carcinogenesis, were determined for each case. Each case showed marked aneuploidy, with an average number of copy alterations of 14.6 (±2.7) in the primary tumors and 19.3 (±4.6) in the cell lines. Both whole‐chromosome and chromosome‐segment imbalances were noted by CGH: consistent losses or gains included +5q23→ter (100%), −3p14→ter (80%), and +7 (70%). All VHL mutations and 83% of the genomic imbalances found in the primary tumors were also found in the cell lines derived from them. SKY showed many complex structural rearrangements that were undetected by conventional banding analysis in these solid tumors. All cases with VHL inactivation had 3p loss and 5q gain related primarily to unbalanced translocations between 3p and 5q. In contrast, gains of chromosome 7 resulted primarily from whole‐chromosome gains and were not associated with mutations of MET. SKY and CGH demonstrated that genomic imbalances in advanced RCC were the result of either segregation errors [i.e., whole chromosomal gains and losses (7.8/case)] or chromosomal rearrangements (10.7/case), of which the majority were unbalanced translocations. © 2003 Wiley‐Liss, Inc.
Heterogeneous pattern of chromosomal breakpoints involving the MYC locus in multiple myeloma
Authors: Fabris Sonia , Storlazzi Clelia Tiziana , Baldini Luca , Nobili Lucia , Lombardi Luigia , Maiolo Anna Teresa , Rocchi Mariano , Neri Antonino 
Published: May 2003

AbstractChromosomal rearrangements of the MYC locus, which often involve the IG loci, are recurrent events in multiple myeloma (MM) and plasma cell leukemia (PCL). We used dual‐color fluorescence in situ hybridization (FISH) to characterize the breakpoint locations of chromosomal translocations/rearrangements involving the MYC locus at 8q24 found in a panel of 14 MM cell lines and 70 primary tumors (66 MM and 4 PCL). MYC locus alterations were observed in 21 cases: MYC/IG (mainly IGH@) fusions in 11 cell lines and three patients (2 MM and 1 PCL), and extra signals and/or abnormal MYC localizations in seven patients (5 MM and 2 PCL). Fourteen of these cases were investigated by FISH analyses by use of a panel of BAC clones covering about 6 Mb encompassing the MYC locus. The breakpoints were localized in a region 100–250 kb centromeric to MYC in four cases, a region 500–800 kb telomeric to the gene in four cases, and regions ≥ 2 Mb centromeric or telomeric to MYC in five cases. Two different breakpoints were detected in the KMS‐18 cell line, whereas the insertion of a MYC allele was found in a complex t(16;22) chromosomal translocation in the RPMI8226 cell line. Our data document a relatively high dispersion of 8q24 breakpoints in MM. © 2003 Wiley‐Liss, Inc.