bluuebunny/crossref_metadata_2025_split huggingface dataset:
Capillary electrophoresis analysis of a wide variety of seized drugs using the same capillary with dynamic coatings
Authors: Lurie Ira S. , Hays Patrick A. , Parker Kimberly 
Published: June 2004

AbstractCapillary electrophoresis methodology is presented for the routine analysis of a wide variety of seized drugs using the same capillary with dynamic coatings and multiple run buffers. The types of exhibits analyzed using diode array UV detection include phenethylamines, cocaine, oxycodone, heroin, lysergic acid diethylamide (LSD), opium, hallucinogenic mushrooms, and γ‐hydroxybutyrate‐γ‐butyrolactone (GHB‐GBL). Both qualitative and quantitative analyses are achieved using run buffers that contain additives that provide for secondary equilibrium and/or dynamic coating of the capillary. Dynamic coating of the capillary surface is accomplished by rapid flushes of 0.1 Nsodium hydroxide, water, buffer containing polycation coating reagent, and a buffer containing a polyanionic coating reagent (with or without cyclodextrin(s)) or a micelle coating reagent. Dynamic coating with a polyanionic coating reagent is used for the analysis of moderately basic seized drugs and adulterants. The use of cyclodextrin in the run buffer not only allows for chiral analysis but also greatly enhances separation selectivity for achiral solutes. A capillary dynamically coated with a micelle allows for the analysis of neutral, acidic, and weakly basic drugs (GHB, GBL and neutral, acidic, and weakly basic adulterants). Dynamic coating, which gives rise to a relatively high and robust electroosmotic flow at pH < 7, allows for rapid, precise and reproducible separations. For a wide variety of drugs, excellent linearity and migration time precision and good peak area precision (external and internal standard) is obtained. Quantitative results for synthetic mixtures are in good agreement with actual values. Screening for adulterants is greatly enhanced by the use of automated library searches.
Simultaneous determination of polyamines and catecholamines in PC‐12 tumor cell extracts by capillary electrophoresis with laser‐induced fluorescence detection
Authors: Du Ming , Flanigan Virgil , Ma Yinfa 
Published: June 2004

AbstractA method to detect polyamines and catecholamines in PC‐12 tumor cell extracts by capillary electrophoresis with laser‐induced fluorescence detection (CE‐LIF) is described for the first time. Both derivatization conditions and buffer concentrations and pH were optimized. Under optimized conditions the polyamines (putresine, spermine, spermidine) and catecholamines (dopamine, norepinephrine, epinephrine, serotonin) were derivatized with fluorescein isothiocyanate and separated at 25 kV in a fused‐silica capillary (50 μm ID×40 cm) with 0.1 M borate, pH 9.0, in less than 18 min. The influence of running buffer conditions, such as buffer pH and concentrations, were also investigated. Linearity of the analytes ranged from 0.05 to 1.0 μmol/L, and the detection limit (S/N = 3 ) ranged from 0.03 to 2.50 nmol/L. The concentrations of polyamines and catecholamines in PC‐12 tumor cell extracts were determined with this method.
Insulator‐based dielectrophoresis for the selective concentration and separation of live bacteria in water
Authors: Lapizco‐Encinas Blanca H. , Simmons Blake A. , Cummings Eric B. , Fintschenko Yolanda 
Published: June 2004

AbstractInsulator‐based dielectrophoresis (iDEP) was utilized to separate and concentrate selectively mixtures of two species of live bacteria simultaneously. Four species of bacteria were studied: the Gram‐negative Escherichia coli and the Gram‐positive Bacillus subtilis, B. cereus, and B. megaterium. Under an applied direct current (DC) electric field all the bacterial species exhibited negative dielectrophoretic behavior. The dielectrophoretic separations were carried out in a glass microchannel containing an array of insulating posts. The insulating posts in the microchannel produced nonuniformities in the electric field applied along the channel. Mixtures of two species of bacteria were introduced into the microchannel and the electric field was applied. The bacterial species exhibited different dielectrophoretic mobilities under the influence of the nonuniform field. From these experiments a trapping order was established with E. coli trapping at the weakest applied electric field, while the Bacillus species were trapped at different characteristic threshold fields. At stronger applied electric fields, the two different species of bacteria in the microchannel were dielectrophoretically trapped into two spatially distinct bands. The results showed that iDEP has the potential to selectively concentrate and separate different species of bacteria.
A novel microstep device for the size separation of cells
Authors: Vankrunkelsven Sarah , Clicq David , Pappaert Kris , Ranson Willy , De Tandt Cathleen , Ottevaere Heidi , Thienpont Hugo , Baron Gino V. , Desmet Gert 
Published: June 2004

AbstractWe report on a series of preliminary experiments investigating the applicability of a novel method for the size separation of nano‐ and microsized particles and cells. The working principle is based on the application of a shear‐driven flow through stepwise tapered micro‐ or nanochannels. Size separations of mixtures of 0.5 and 1.0 μm carboxylated polystyrene beads as well as of binary mixtures of Staphylococcus aureus and Saccharomyces cerevisiae cells and of S. cerevisiae and Escherichia coli cells are demonstrated.
Nanobiotechnology: From Molecules to Systems
Authors: Klefenz H. 
Published: June 2004

AbstractNanobiotechnology is a key enabling multidisciplinary field for medical, technological and biological research and development, medicine, pharmaceutical development, and analytical sciences. Its foundation is the selective integration of a multitude of endeavours, such as biotechnology, chemical and physical nanotechnology, materials sciences, chemistry, engineering, electronics and optronics targeting the construction of micro‐ and nano‐arrays for analyzing complex mixtures of DNA, RNA, proteins, metabolites as well as the design of ultra‐sequencing devices, microbial fuel cells, implantates, molecular motors, artificial organs, and nanorobots. The developments in nanobiotechnology benefit from and contribute to the scientific advances in the chemical and physical nanotechnologies, in particular with respect to materials, composites, nanostructuring techniques, carbon nanotubes, and nanoelectronics.
Production of Laccase by Trametes hirsuta Grown in an Immersion Bioreactor and its Application in the Docolorization of Dyes from a Leather Factory
Authors: Couto S.R. , Sanroman M.A. , Hofer D. , Gübitz G.M. 
Published: June 2004

AbstractAn alternative system for producing laccase on a bioreactor scale by the white‐rot fungus Trametes hirsuta is proposed. The experiments were performed in an immersion bioreactor (employing cuttings of stainless steel sponges as a support) and the culture medium was supplemented with copper sulfate (1 mM). Operating under these conditions, it was possible to obtain a maximum laccase activity of nearly 5,000 U/L within 9 days. In addition, the ability of the crude laccase produced to decolorize two synthetic acid dyes utilized in the leather industry (Luganil Green and Sella Solid Red) was investigated. The effect of the pH and the enzyme activity on decolorization was analyzed. It was found that a pH of 4.0 and a laccase activity of 300 U/L were optimal for Luganil dye decolorization (16.2 % in 2 hours). Sella Solid Red showed its highest decolorization (around 40 % in 2 hours) when used at pH 5.0 and at a laccase activity of 1,000 U/L.
Zinc and Copper Bioaccumulation in Brassica napus at Flowering and Maturation
Authors: Rossi G. , Figliolia A. , Socciarelli S. 
Published: June 2004

AbstractThe aim of this research was to investigate the capability of Brassica napus to bioaccumulate zinc and copper from artificially contaminated soil at the flowering and maturation phenological stage. The trial was set up in a greenhouse and the plants were cultivated in pots. The agricultural soil utilized was contaminated with zinc and copper sulfate (300 and 600 mg/kg, respectively). The soil and plant samples were simultaneously collected during the flowering (8 weeks after seeding) and maturation (harvest time, 13 weeks after seeding) stages, and the heavy metal concentrations were then analyzed. The production of vegetable biomass and the length of the roots were measured. The results showed that B. napus accumulated zinc and copper and translocated these elements in different ways in the harvestable parts of the plants. The zinc bioaccumulation was higher than that of copper. At flowering, zinc was mainly accumulated in the shoots (stems + leaves). Copper was particularly accumulated in the roots, during the entire life cycle. Taking into account the biomass production, the highest heavy metal removal by the shoots (above‐ground parts) occurred at the flowering stage for both zinc and copper. The high bioavailability of zinc and copper in the soil did not severely affect the root length and the biomass production.
Simplified Modeling of Simultaneous Reaction Kinetics of Carbon Oxidation and Nitrification in Biofilm Processes
Authors: Tsuneda S. , Auresenia J. , Hibiya K. , Hirata A. 
Published: June 2004

AbstractBatch experiments with varying initial substrate concentrations and biomass volumes were performed in a three‐phase fluidized bed biofilm reactor treating simulated domestic wastewater to study the simultaneous carbon oxidation and nitrification in the biofilm process. A simplified mass balance equation for the biofilm was proposed and five different kinetic rate equations were used to match the actual data. The kinetic parameters were obtained by nonlinear regression analysis on a set of two differential equations representing the simultaneous carbon oxidation and nitrification. The competitive inhibition model incorporating the effects of total organic carbon (TOC) concentrations on nitrification rates was the best‐suited model based on the average r2. In this model, oxygen concentration and its affinity constants were not included. Instead, it was assumed that the rate of carbon oxidation is independent of the NH4+‐N, while nitrification is affected by TOC. The number of parameters was successfully minimized without reducing its ability to accurately predict the bulk concentration time course, which would reduce computational complexity and possibly enhance the availability for an actual wastewater treatment process.
Removal of Chromium(VI) Ions from Synthetic Solutions by the Fungus Penicillium purpurogenum
Authors: Say R. , Yilmaz N. , Denizli A. 
Published: June 2004

AbstractThe ability of Penicillium purpurogenum to bind high amounts of chromium(VI) from aqueous solutions is demonstrated. Cr(VI) adsorption capacity increases with time during the first four hours and then leveled off toward the equilibrium adsorption capacity. Biosorption of Cr(VI) ions reached equilibrium in four hours. Binding of Cr(VI) ions with Penicillium purpurogenum biomass was clearly pH dependent. Cr(VI) loading capacity increased with increasing pH. The adsorption of Cr(VI) ions reached a plateau value at a pH of approx. 6.0. The maximum capacity of adsorption of Cr(VI) ions onto the fungal biomass was 36.5 mg/g. Adsorption behavior of Cr(VI) ions can be approximately described with the Langmuir equation. When applying the Langmuir model, the maximum adsorption capacity (Qmax) and the Langmuir constant were found to be 40 mg/g and 3.9 × 10–3 mg/L. Elution of Cr(VI) ions was performed by means of 0.5 M HCl. It was possible to use the biomass of Penicillium purpurogenum for six cycles for biosorption.
Genomic context of paralogous recombination hotspots mediating recurrent NF1 region microdeletion
Authors: Forbes Stephen H. , Dorschner Michael O. , Le Rosalynda , Stephens Karen 
Published: June 2004

AbstractRecombination between paralogs that flank the NF1 gene at 17q11.2 typically results in a 1.5‐Mb microdeletion that includes NF1 and at least 13 other genes. We show that the principal sequences responsible are two 51‐kb blocks with 97.5% sequence identity (NF1REP‐P1‐51 and NF1REP‐M‐51). These blocks belong to a complex group of paralogs with three components on 17q11.2 and another on 19p13.13. Breakpoint sequencing of deleted chromosomes from multiple patients revealed two paralogous recombination hot spots within the 51‐kb blocks. Lack of sequence similarity between these sites failed to suggest or corroborate any putative cis‐acting recombinogenic motifs. However, the NF1REPs showed relatively high alignment mismatch between recombining paralogs, and we note that the NF1REP hot spots were regions of good alignment bordered by relatively large alignment gaps. Statistical tests for gene conversion detected a single significant tract of perfect match between the NF1REPs that was 700 bp long and coincided with PRS2, the predominant recombination hot spot. Tracts of perfect match occurring by chance may contribute to breakpoint localization, but our result suggests that perfect tracts at recombination hot spots may be a result of gene conversion at sites at which preferential pairing occurs for other, as‐yet‐unknown reasons. © 2004 Wiley‐Liss, Inc.
Black and white women managers: Access to opportunity
Authors: Hite Linda M. 
Published: June 2004

AbstractThis study explores the differing views of Black and White female managers regarding access to key career opportunities for White women and women of color. Items addressed include access to hiring, promotions, key assignments, salary increases, acknowledgment for work, and mentors. Access to each is described by comparing White women and women of color to one another, to White men, and to men of color. Chi‐square analyses of survey responses from the 276 U.S. participants showed that most of the White respondents consistently perceived equal access to career opportunities for women of color. In contrast, most of the Black participants indicated that disparity exists in career opportunities available to women of color compared to White men and women. The implications of these results are discussed.
Invited reaction: Black and white women managers: Access to opportunity
Authors: Higginbotham Elizabeth 
Published: June 2004

AbstractIn a survey of Black and White women managers, Linda M. Hite identifies differences in the managers' perceptions of opportunities available to different race and gender groups. Her findings reveal divergent beliefs about the opportunities for people of color; there is more similarity in Black and White women's views when comparing opportunities for White women and men for getting hired, promoted, receiving salary increases, and other workplace challenges. When making comparisons with either men or women of color, White women are far more optimistic about the opportunities for people of color than are Black women. Hite uses this study to explore the lack of attention to race and racial discrimination among White women, whose views are often assumed to represent all women in management. HRD practice and research can look more closely at the perceptions and experiences of Black women to learn how better to promote their careers, since strategies that increase the number of White women might not be helpful in advancing the careers of Black and other women of color.
Challenges and choices for theoretical research in human resource development
Authors: Torraco Richard J. 
Published: June 2004

AbstractTheoretical research in HRD has established itself and is now at a point where many avenues exist for further contributions to the field. But what kinds of theoretical research appear to be needed at this stage in the development of HRD? This paper identifies areas in which further research in theory and theory building might be conducted. Possible areas for future research include new HRD theory, theory‐building research methods, HRD's theoretical foundation, and published work that includes both the theory‐building research process and the theory itself. The paper argues that as more theory is being developed, the justification of the need for theory becomes more important. Considering the merits of alternative theoretical contributions, HRD professionals are asked to make judicious choices about the direction of future theoretical research. The implications of this study for further research and professional practice are provided.
The effectiveness of managerial leadership development programs: A meta‐analysis of studies from 1982 to 2001
Authors: Collins Doris B. , Holton Elwood F. 
Published: June 2004

AbstractEighty‐three studies from 1982 to 2001 with formal training interventions were integrated via meta‐analytic techniques to determine the effectiveness of interventions in their enhancement of performance, knowledge, and expertise at the individual, team or group, or organizational level. The studies were separated by research design, with the outcome measure of the intervention as the unit of analysis. The effect size for knowledge outcomes ranged from .96 to 1.37; expertise outcomes from .35 to 1.01; and system outcomes averaged .39. Interventions with knowledge outcomes were found to be more effective than in the Burke and Day (1986) meta‐analysis, with the most effective interventions using a single group pretest‐posttest research design. Methodological and conceptual differences in Burke and Day's meta‐analysis on the effectiveness of managerial training make historical comparisons risky. The data suggest that practitioners can attain substantial improvements in both knowledge and skills if sufficient front‐end analysis is conducted to assure that the right development is offered to the right leaders.
Global human resource development: The four C approach
Authors: Petranek Gregory F. 
Published: June 2004

AbstractThe Four C approach defines a method to assist human resource development professionals design strategic global training in a multinational environment. The method was developed from an analysis of published global HRD articles and two books. Four common elements were discovered during the review of the design and development of global HRD. Cooperation, collaboration, communication, and culture are the Four Cs that form the backbone of any global HRD organization. This approach is at the conceptual level with the mechanics of implementation left up to the HRD professional. Each section of the Four Cs presents the definition, discuss application, and summarize implementation. The opinion of the author is presented in the context of instructional system design to facilitate understanding the Four Cs.
Analysis of HLA antigen expression in benign and malignant melanocytic lesions reveals that upregulation of HLA‐G expression correlates with malignant transformation, high inflammatory infiltration and HLA‐A1 genotype
Authors: Ibrahim El Chérif , Aractingi Sélim , Allory Yves , Borrini Francesco , Dupuy Alain , Duvillard Pierre , Carosella Edgardo D. , Avril Marie Françoise , Paul Pascale 
Published: June 2004

AbstractPrevious studies indicate that the nonclassical class I HLA‐G antigen, whose physiologic expression is mainly restricted to placenta, is upregulated in melanoma, renal carcinoma, lung carcinoma, glioblastoma and ovarian carcinoma, where its inhibitory effect on cytotoxic effector cells function is thought to participate in immune evasion by tumor cells. To define whether this expression was a specific feature of melanocytic malignant transformation, 174 paraffin‐embedded melanocytic lesions including naevi, lentigo, primary and metastatic melanomas were analyzed for HLA‐G and other HLA class I and class II antigen expression. HLA‐G antigen expression in melanocytic cells was found to be significantly higher (p < 0.0003) in melanoma (22/79, 28%) than in naevi (1/70, 1.4%), suggesting that upregulation of HLA‐G is associated with malignant transformation in this cell type. Further identification of HLA‐G antigen expression in inflammatory infiltrating cells results in an overall frequency of HLA‐G expressing cells that is higher in melanoma (28/79, 35.5%) than in naevi (5/60, 8.3%) or lentigo (2/23, 8.7%). Upregulation of HLA‐G or HLA class II molecules in melanocytic cells thus appears as a better predictor of malignancy than classical HLA class I antigen defects, which are often described as an important mechanism used by tumor cells to evade immune surveillance. Furthermore, HLA‐G expression was electively found in lesions that exhibited a high inflammatory infiltrate as well as in patients displaying HLA‐A1 genotype. These findings may provide new insights in the comprehension of tumor progression and design of therapeutic approaches aimed at enhancing antitumor immune responses in melanoma patients. © 2003 Wiley‐Liss, Inc.
Rapamycin inhibits cdk4 activation, p 21WAF1/CIP1 expression and G1‐phase progression in transformed mouse fibroblasts
Authors: Gaben Anne‐Marie , Saucier Cecile , Bedin Monique , Barbu Véronique , Mester Jan 
Published: June 2004

AbstractRapamycin, a bacterial macrolide antibiotic, is a potent immunosuppressant agent that blocks cell proliferation by inhibiting the G1/S transition in several cell types. In sensitive cells, rapamycin inhibits the phosphorylation of p70 S6K and of Rb; however, the precise mechanisms involved have not been elucidated. In the mouse BP‐A31 fibroblasts, synchronised in G0/G1 phase by serum starvation and induced to reinitiate the G1‐phase progression, rapamycin inhibited the entry into S phase. The effect of rapamycin was situated in early G1 phase. The assembly of the cyclin D1/cdk4 complexes that phosphorylate Rb early in the G1 phase was not modified by the drug. Nevertheless, an inhibition of the activation of cyclin D1/cdk4 and cyclin E/cdk2 as well as of Rb phosphorylation accompanied the cell cycle arrest. Remarkably, rapamycin reduced the level of total p21WAF1/CIP1 as well as that of p21WAF1/CIP1 associated with the cyclin D1/cdk4 complexes. Besides its inhibitory activity toward cdk, p21WAF1/CIP1 has been recently found to participate in the formation/stabilisation/nuclear translocation of cyclin D1/cdk4 complexes. We propose that the inhibition of the expression of p21WAF1/CIP1 is a mechanism by which rapamycin inhibits the triggering of the cdk cascade in the BP‐A31 cells. © 2003 Wiley‐Liss, Inc.