bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metallomesogenic stationary phase for open‐tubular capillary electrochromatography
Authors: Chen Jian‐Lian 
Published: January 2006

AbstractA synthetic coppermesogenic polymer is prepared and then covalently bonded to the siloxane‐based deactivated column as the stationary phases of open‐tubular CEC with essentially high phase ratio. The EOF generated from the modified phase is surveyed through conventional aqueous buffers and hydroorganic mobile phases. Zeta potentials, which are computed from the EOF data and the ratio of dielectric constant to viscosity, are plotted as a function of pH, ionic molarity, and compositional range. These plots responsible for the electroosmotic characteristic of the bonded phases are found to be like those of bare fused‐silica or deactivated columns through decreasing or increasing the ACN content in the mobile phase, respectively. This two‐phase characteristic is basically derived from the polymeric configuration with carboxylato ligands attached onto the polysiloxane backbone. Phthalates and amino acids are suitable probes to examine the two phenomena, more‐polar and less‐polar mediums, respectively, and to judge whether the chromatographic retention is the major source of separation mechanism. With the mixing modes of Lewis acid–base interaction, dispersive force, and shape discrimination, the chromatographic partition adequately accomplishes the uneasily resolved separations by only CZE mode, although the electrophoretic migration is truly somewhat involved.
Investigation of vesicle electrokinetic chromatography as an in vitro assay for the estimation of intestinal permeability of pharmaceutical drug candidates
Authors: Pascoe Robert J. , Masucci John A. , Foley Joe P. 
Published: January 2006

AbstractAs the pharmaceutical industry continues the daunting search for novel drug candidates, there remains a need for rapid screening methods not only for biological activity, but for physiochemical properties as well. It is invaluable that adequate model systems for absorption and/or bioavailability be developed early in the drug evaluation process to avoid the loss of promising compounds late in development. The focus of this paper is the use of vesicle EKC (VEKC) as a high‐throughput, easy, cost‐effective, and predictive model for the passive transcellular diffusion of drug candidates in the intestinal epithelium. Vesicles are large aggregates of molecules containing a spherical bilayer structure encapsulating an internal cavity of solvent. It is this bilayer structure that makes vesicles attractive as model membranes. In this study, vesicles were synthesized from both phospholipids and surfactant aggregates, and then employed as pseudostationary phases in EKC (VEKC). The interaction of drug molecules with vesicles in EKC was then used as the basis for an in vitro assay to evaluate passive diffusion. The VEKC technique showed a statistical correlation between the retention of drug candidates using surfactant and phospholipid vesicles and passive diffusion data (log Pow and colon adenocarcinoma). VEKC analysis offers high‐throughput capabilities due to the short run times, low sample, and solvent volumes necessary, as well as instrument automation. However, due to the complexity of drug absorption in the intestine, difficulty arises when a single in vitro model is used to predict in vivo absorption characteristics. Therefore, the retention of drug candidates using VEKC in conjunction with other permeability prediction methods can provide a primary screen for a large number of drug candidates early in the drug discovery process with minimal resources.
Dynamic process of phospholipid–protein interaction studied by capillary isoelectric focusing with whole‐column imaging detection
Authors: Bo Tao , Pawliszyn Janusz 
Published: January 2006

AbstractLiposomes are vesicles formed by the aggregation of amphiphilic phospholipid molecules, which can mimic natural cell membranes. Interaction between liposome and protein is important for the structure and function of natural cell membranes. In this study, a CIEF method with whole‐column imaging detection was developed for monitoring the dynamic process of phospholipid–protein interactions. The CIEF profiles at successive interaction times clearly displayed the formation of the different conjugates between phospholipid and protein at different stages. Due to the diversity of the chemical and physical properties of targeted proteins in this study (trypsin inhibitor, β‐lactoglobulin B, phosphorylase b, and trypsinogen), different dynamic processes of phospholipid–protein interactions were exhibited. The type of phospholipids played an important role in the dynamic process of phospholipid–protein interaction, as noted by the use of zwitterionic phospholipid (phosphatidylcholine) and acidic phospholipid (phosphatidylserine). Mechanisms involved in these interactions were discussed by monitoring the dynamic processes in this study.
Application of a geographic information system to explore associations between air pollution and micronucleus frequencies in African American children and adults
Authors: Huen Karen , Gunn Laura , Duramad Paurene , Jeng Michael , Scalf Russell , Holland Nina 
Published: January 2006

AbstractExposure to air pollution has been associated with adverse respiratory and cardiovascular health outcomes in both children and adults. In this study, we used geographic information systems (GISs) to explore possible associations between chromosomal damage in 65 African American children and their mothers from Oakland, California, and both proximity to traffic and regional ozone levels. Study participants were interviewed at the Healthy Child Clinic of Children's Hospital, Oakland, and their blood and buccal cells were collected for assessment of chromosomal damage by the micronucleus (MN) assay. Regional ozone levels, which decreased from April to November with a secondary peak in late summer, were highly correlated with season by month (r = −0.84, P = 0.02) and strongly associated with MN frequency (frequency ratio (FR): 3.37, 95% confidence interval (CI): 1.30–8.72) in both cell types of children and adults. Additionally, MN frequencies were modestly associated with individual measures of traffic density in children (FR = 2.45, 95% CI= 0.86–7.10), but not in adults; this suggests a greater vulnerability to traffic‐related air pollution in children. Smoking in the household also increased MN frequency in the lymphocytes of children (FR: 1.13, 95%CI: 1.01–1.24) and adults (FR: 1.06, 95%CI: 0.99–1.13), whereas vitamin use in adults decreased MN frequency in both lymphocytes and buccal cells (FR: 0.17, 95%CI: 0.02–1.31; FR: 0.18, 95%CI: 0.03–1.18, respectively). Our data indicate that GIS‐generated measures of traffic density for individual households augment regional ozone monitoring data used to assess effects of air pollution. This approach helped to demonstrate elevated cytogenetic damage in exposed minority children. Environ. Mol. Mutagen., 2006. © 2006 Wiley‐Liss, Inc.
Searching PubMed for molecular epidemiology studies: The case of chromosome aberrations
Authors: Ugolini Donatella , Neri Monica , Knudsen Lisbeth E. , Bonassi Stefano , Merlo Domenico Franco 
Published: January 2006

AbstractThe available tools for searching literature in the field of Molecular Epidemiology are largely unsatisfactory. To identify major problems in retrieving information on this discipline, we comment here on the results of a literature search on cytogenetic biomarkers in children exposed to environmental pollutants. The search, done on the PubMed/MedLine database, was based on a strategy combining descriptors listed in the PubMed Medical Subject Headings (MeSH) Thesaurus and other available tools (free text or phrase search tools). 178 articles were retrieved by searching the period from January 1, 1980 to November 30, 2004. Only 2 of the 178 articles were indexed by the MeSH term “Epidemiology, molecular” (introduced in 1994) and 30 of 178 by the MeSH term “Biological markers” (introduced in 1989). The case of chromosome aberration (CA) was emblematic of the problem: 44 of 78 articles (56.4%) were not pertinent to the search. The reasons for this poor performance are reported and discussed. Authors and indexers may be able to improve the efficiency of article retrieval in the field of molecular epidemiology by using relevant terms in the title and abstract. This may suggest appropriate MeSH terms to the indexers for the indexing process. As regards the difficulty in identifiyng population studies using CA, the introduction of a specific MeSH term for chromosome aberrations when used as a biomarker would improve the search process. Environ. Mol. Mutagen., 2006. © 2006 Wiley‐Liss, Inc.
Quercetin reduces chromosome aberrations induced by atrazine in theAllium cepatest
Authors: Mastrangelo Sabina , Tomassetti Massimiliano , Carratù Maria Rosaria , Evandri Maria Grazia , Bolle Paola 
Published: January 2006

AbstractQuercetin is a widely distributed plant flavonoid possessing a variety of chemical and biological activities, including chelation, free‐radical scavenging, and antioxidant activity. Atrazine is a selective triazine herbicide that has been the subject of an international revision program for human and ecological health risks because of its persistence in the environment. In a previous study, we demonstrated that atrazine was clastogenic in theAllium cepatest. In this present study, we investigated whether quercetin affords protection from the chromosome breaks induced by atrazine. In a preliminary assay, 0.1–20 μg/ml quercetin produced no toxicity or clastogenic activity in theAllium cepatest. Subsequently, we evaluated the effects of 0.5 and 5 μg/ml quercetin on the clastogenicity of 2.5, 5.0, and 7.5 μg/l atrazine. Quercetin (0.5 μg/ml) significantly reduced the frequency of total aberrations induced by 7.5 μg/l atrazine, while both concentrations of quercetin significantly decreased the frequency of fragments induced by 7.5 μg/l atrazine. The results of this study indicate that plant flavonoids such as quercetin may protect against the genotoxic effects of atrazine. Efforts to understand the extent to which plant flavonoids influence the biological activities of genotoxicants and the mechanisms involved in the interactions could help to better discern the advantages and disadvantages of their use and to clarify their possible protective role against pollutants. Environ. Mol. Mutagen., 2006 © 2006 Wiley‐Liss, Inc.
No association of endometriosis with galactose‐1‐phosphate uridyl transferase mutations in a Chinese population
Authors: He Chunni , Song Yanfeng , He Xiaoyu , Zhang Wenju , Liao Lianming 
Published: January 2006

AbstractThe linkage between endometriosis and galactose‐1‐phosphate uridyl transferase gene (GALT) mutations is controversial. In this study, the prevalence of the most common GALT mutations, Q188R and N314D, was assessed in women with endometriosis in a Chinese population. Three hundred twenty five unrelated women with endometriosis were enrolled. Samples of umbilical cord blood obtained from 310 female newborn infants were used as population controls. Genomic DNA isolated from endometriosis patients and controls were subjected to multiple polymerase chain reactions to determine the Q188R and N314D mutations. There was no significant difference in the frequencies of the Q188R and N314D mutations between endometriosis patients and controls. The endometriosis patients were further divided into subgroups of stage III and IV disease, but still no statistically significant differences were observed in the frequency of the Q188R and N314D mutations between any of these groups and the controls. These findings suggest that Q188R and N314D mutations are not likely to be associated with an increased risk of endometriosis among Chinese Women. Environ. Mol. Mutagen., 2006 © 2006 Wiley‐Liss, Inc.
Solar photocatalytic degradation of groundwater contaminated with petroleum hydrocarbons
Authors: Cho Il‐Hyoung , Kim Lee‐Hyung , Zoh Kyung‐Duk , Park Jae‐Hong , Kim Hyun‐Yong 
Published: January 2006

AbstractTo evaluate the potential use for ex situ remediation, a solar‐driven, photocatalyzed reactor system was constructed and applied to the treatment of groundwater contaminated with benzene, toluene, ethylbenzene, and xylene (BTEX) and total petroleum hydrocarbons (TPHs) near a gas station using selected advanced oxidation processes such as H2O2/solar light, TiO2 slurry/solar light, and immobilized TiO2/solar light. Groundwater samples containing BTEX and TPH, loaded with H2O2 or slurry and immobilized TiO2 catalyst, were exposed to solar light (37° N and 128° E) in winter with an average intensity of 1.6 mW/cm2 measured at 365 nm. Whereas the solar light/TiO2 slurry system achieved >70% degradation of BTEX and TPH within 4 h, the solar light/immobilized TiO2 and solar light/H2O2 systems did not show significant removal within the same time. However, both TiO2 slurry and immobilized systems were able to reduce BTEX and TPH levels effectively if H2O2 (10 mM) was added. The degradation rates of low molecular weight gasoline (BTEX) and n‐alkanes ranging from C10 to C15 were higher than those of n‐alkanes ranging from C16 to C20. The removal efficiency of BTEX and TPH in the groundwater samples also increased with a larger solar collector area of the reactor. © 2006 American Institute of Chemical Engineers Environ Prog, 2006
Some indicators of socio‐economic status may not be reliable and use of indices with these data could worsen equity
Authors: Onwujekwe Obinna , Hanson Kara , Fox‐Rushby Julia 
Published: January 2006

AbstractSocio‐economic status (SES) indices are increasingly being used to characterise (in)equity, with the assumption that SES indices are reliable. However, the accuracy of such SES indices is questionable if they are unreliable. We examined the inter‐rater and test–retest reliability of a range of indicators commonly used to generate SES indices as well as the composite SES indices. Results from research in southeast Nigeria showed considerable variation, with some indicators having only low to moderate reliability (reliability coefficients 0.25–0.77). Inter‐rater and test–retest reliability of SES indices was 0.63 in both cases. Many households were misclassified because of the unreliable SES indices. Analyses of the distribution of resources based on such indicators could lead to inaccuracies in benefit incidence estimates and policy decisions based on low to moderately reliable SES indicators could worsen equity in access to and use of resources. Greater rigour is needed in conceptualising as well as undertaking SES measurements. Copyright © 2006 John Wiley & Sons, Ltd.
Non‐linearity in the cost‐effectiveness frontier
Authors: Lord Joanne , Laking George , Fischer Alastair 
Published: January 2006

AbstractConventional cost‐effectiveness decision rules rely on the assumptions that all health care programmes are divisible and exhibit constant returns to scale for a homogeneous population; hence, the path between adjacent programmes on a cost‐effectiveness frontier must be linear. In this paper we build a framework to analyse non‐linear ‘expansion’ paths. We model the impact of two key sources of non‐linearity: economies of scale or scope in the production of health care; and prioritisation of patients who are most likely to benefit from more expensive and more effective treatments. We conclude that the expansion path might be linear, convex or concave, depending on the situation. The path might also exhibit vertical discontinuity due to fixed costs or horizontal discontinuity due to indivisibility. The efficiency of resource allocation might be improved by empirical estimation of expansion paths. We discuss the advantages and disadvantages of this approach compared with a standard stratified analysis. Copyright © 2006 John Wiley & Sons, Ltd.
Amino acids as carbon, energy and nitrogen sources for Penicillium camembertii
Authors: Adour Lydia , Aziza Majda , Couriol Catherine , Amrane Abdeltif 
Published: January 2006

AbstractThree groups of amino acids were previously characterized on their ability to be assimilated as carbon source by Penicillium camembertii. In view of a deeper understanding of their metabolic behaviour, growth of P. camembertii on glucose, the limiting substrate, and an amino acid was examined in batch culture. Amino acids from the first group (Cys, His, Lys, Met, Trp and Val) are convenient nitrogen sources, but cannot be assimilated as carbon sources. However, they are also dissimilated, namely used for energy supply by oxidation into CO2, during stationary phase, after glucose depletion, as shown for lysine; and the corresponding nitrogen was released as ammonium. Growth exhibited diauxic behaviour for the second group of amino acids (Arg, Leu), since they can be assimilated as carbon sources, in addition to their assimilation as nitrogen sources, but only after glucose depletion, as shown for arginine. A clear differentiation between the assimilated and the dissimilated carbon was demonstrated for the third group of amino acids (Ala, Asp, Glu, Gly, Pro, Ser, Thr); it was shown that the carbon from glutamic acid was assimilated, while the carbon from glucose was dissimilated. Copyright © 2006 Society of Chemical Industry
Mathematical modeling of the batch fermentation of Zoogloea sp. GY3 used for synthesizing polyhydroxyalkanoates
Authors: Yang JinShui , Huang JianXin , Ni JinRen 
Published: January 2006

AbstractA mathematical model that describes strain growth, product formation and medium consumption is used to predict the performance of batch fermentation of Zoogloea sp. GY3, screened from activated sludge. Zoogloea sp. GY3 is useful in synthesizing polyhydroxyalkanoates (PHAs). The model is based on the Logistic equation for microorganism growth, the Luedeking–Piret equation for production of PHAs and a Luedeking–Piret‐like equation for sucrose consumption, and appears to provide a reasonable description of the behavior of each parameter during the growth phase. The results show that the production of PHAs is growth‐associated, and the model predictions are in satisfactory agreement with measured data. Copyright © 2006 Society of Chemical Industry
Compression of fluorescence microscopy images based on the signal‐to‐noise estimation
Authors: Bernas Tytus , Asem Elikplimi K. , Robinson J. Paul , Rajwa Bartek 
Published: January 2006

AbstractModern microscopic techniques like high‐content screening (HCS), high‐throughput screening, 4D imaging, and multispectral imaging may involve collection of thousands of images per experiment. Efficient image‐compression techniques are indispensable to manage these vast amounts of data. This goal is frequently achieved using lossy compression algorithms such as JPEG and JPEG2000. However, these algorithms are optimized to preserve visual quality but not necessarily the integrity of the scientific data, which are often analyzed in an automated manner. Here, we propose three observer‐independent compression algorithms, designed to preserve information contained in the images. These algorithms were constructed using signal‐to‐noise ratio (SNR) computed from a single image as a quality measure to establish which image components may be discarded. The compression efficiency was measured as a function of image brightness and SNR. The alterations introduced by compression in biological images were estimated using brightness histograms (earth's mover distance (EMD) algorithm) and textures (Haralick parameters). Furthermore, a microscope test pattern was used to assess the effect of compression on the effective resolution of microscope images. Microsc. Res. Tech. 69:1–9, 2006. © 2006 Wiley‐Liss, Inc.
Image adaptive point‐spread function estimation and deconvolution for in vivo confocal microscopy
Authors: Von Tiedemann M. , Fridberger A. , Ulfendahl M. , De Monvel J. Boutet 
Published: January 2006

AbstractVisualizing deep inside the tissue of a thick biological sample often poses severe constraints on image conditions. Standard restoration techniques (denoising and deconvolution) can then be very useful, allowing one to increase the signal‐to‐noise ratio and the resolution of the images. In this paper, we consider the problem of obtaining a good determination of the point‐spread function (PSF) of a confocal microscope, a prerequisite for applying deconvolution to three‐dimensional image stacks acquired with this system. Because of scattering and optical distortion induced by the sample, the PSF has to be acquired anew for each experiment. To tackle this problem, we used a screening approach to estimate the PSF adaptively and automatically from the images. Small PSF‐like structures were detected in the images, and a theoretical PSF model reshaped to match the geometric characteristics of these structures. We used numerical experiments to quantify the sensitivity of our detection method, and we demonstrated its usefulness by deconvolving images of the hearing organ acquired in vitro and in vivo. Microsc. Res. Tech. 69:10–20, 2006. © 2006 Wiley‐Liss, Inc.
NADPH‐diaphorase activity in the superficial layers of the superior colliculus of rats during aging
Authors: Díaz Florentina , Villena Alicia , Vidal Lourdes , Moreno Mercedes , De Vargas Ignacio Pérez 
Published: January 2006

AbstractNeurons in the superficial layers of the superior colliculus are key elements in the visual system of rodents since they receive extensive afferent projections from retinal ganglion cells. The NADPH‐diaphorase histochemical technique was used to detect differences in neuronal nitric oxide synthase (nNOS) in the superficial layers of the superior colliculus (sSC) of young adult (3 months) and aged (24 and 26 months) rats. The orientation of the dendritic processes of NADPH‐diaphorase‐positive neurons, cross‐sectional area, and number of neurons per mm2 were analyzed. NADPH‐d histochemistry revealed a high number of NADPH‐d‐positive cells in the stratum zonale and stratum griseum superficiale in adult and aged animals. NADPH‐d‐positive neurons were classified into the following morphological types: marginal, horizontal, pyriform, narrow‐field vertical, wide‐field vertical, and stellate. During aging, narrow field vertical and wide field vertical neurons present somatic atrophy and an increase in dendritic processes with dorsoventral orientation, whereas wide field vertical neurons show a decrease in those with lateromedial orientation. Marginal neurons undergo somatic hypertrophy at 26 months when compared with those at 3 months. The remaining types of neurons do not undergo size changes. Finally, the number of NADPH‐d‐positive neurons per mm2 in the various types of morphology does not significantly change with age. It is suggested to be likely that the aging process in the nitrergic neurons of the sSC does not lead to significant changes in the synthesis of NO from the constitutive NOS isoforms. Microsc. Res. Tech. 69:21–28, 2006. © 2006 Wiley‐Liss, Inc.