bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glucocorticoids coordinately regulate type I collagen proα1 promoter activity through both the glucocorticoid and transforming growth factor β response elements: A novel mechanism of glucocorticoid regulation of eukaryotic genes
Authors: Meisler Natalie , Shull Susan , Xie Ronglin , Long George L. , Absher Marlene , Connolly Joseph P. , Cutroneo Kenneth R. 
Published: May 2005

AbstractGlucocorticoids have previously been shown to decrease Type 1 collagen synthesis in vivo and in fibroblast cell culture. Several studies have demonstrated that glucocorticoids decrease Type 1 procollagen gene expression. These latter studies have included uridine incorporation into proα1(I) and proα2(1) mRNas and nuclear run‐off experiments. Using the ColCat 3.6 plasmid, which contains part of the 5' flanking regionof the proα1 (1) coullagen gene and the reporter gene, chljoramphenicol acetyltransferase, the present studies demonstrate by stable transfection of fetal rat skin fibrolblasts that dexamethasone down regulates the promoter activity of the proα1(I) collagen gene. The glucocorticoid‐mediated down‐regulastionof procolljagen gene expression was demonstrated using the ColCat 3.6, 2.4, 1.7, or 0.9 plasmid. In addition, competitive oligonucleotide transfection experiments and site specific mutation of the glucocorticoid response element (GRE) in the whoulue ColCat 3.6 plasmid did not elimiinatre the effect. The ipossibility existed that another cis‐element inthe 5' flanking region of the proα1(I) collagen gene was also required for the glucocorticoid‐mediated down‐regulation of procollagen gene expression, since TGF‐β has been shown to stimulate collagen proα1(I) and proα2(I) gene activities. Dexamethasone treatment of non‐transfected skin fibroblasts did result in a decrease of transforming growth factor‐β. The decrease of CVAT activity by dexamethasone was brought back to control value by the addition of exogenous TGF‐β to the culture media. Gel mobility studies demonstrated that glucocorticoid treatment of rat skin fibroblasts decreased glucocorticoid recptor binding to the GRE and TGF‐β activator protein to the TGF‐β element which were brought back to control values by coordinate exogenous TGF‐β treatment. Thus the interaction of these TGF‐β molecules with cellular membrane receptors and subsequent rtransduction is dramatically decreased resulting in less signals to regulate collagen gene expression. These data indicate that glucocorticoids coordinately regulate procollagen gene expfrssion through both the GRE and TGF‐β elements. Depression of procollagen gene expression by glucocorticoids through the TGF‐β element is mediated by decreased TGF‐β secretion, possibly involving a secondary effect on regulatory protein(s) encoded by noncollagenous protein gene(s). The present studies provide the bassis for a novel mechanism of glucocorticoid‐mediated regulation of eukaryotic genes containing the TGF‐β element. © 1995 Wiley‐Liss, Inc.
Phosphorylation of elF‐4E and initiation of protein synthesis in P19 embryonal carcinoma cells
Authors: Kleijn Miranda , Voorma Harry O. , Thomas Adri A. M. 
Published: May 2005

AbstractMitogenic stimulation of protein synthesis is accompanied by an increase in elF‐4E phosphorylation. The effect on protein synthesis by induction of differentiation is less well known. We treated P19 embryonal carcinoma cells with the differentiating agent retinoic acid and found that protein synthesis increased during the first hour of addition. However, the phosphorylation state, as well as the turnover of phosphate on elF‐4E, remained unchanged. Apparently, the change in protein synthesis after RA addition is regulated by another mechanism than elF‐4E phosphorylation.By using P19 cells overexpressing the EGF receptor, we show that the signal transduction pathway that leads to phosphorylation of elF‐4E is present in P19 cells; the EGF‐induced change in phosphorylation of elF‐4E in these cells is likely to be regulated by a change in elF‐4E phosphatase activity.These results suggest that the onset of retinoic acid‐induced differentiation is triggered by a signal transduction pathway which involves changes in protein synthesis, but not elF‐4E phosphorylation. © 1995 Wiley‐Liss, Inc.
Cyclic‐AMP deficient MDCK cells form tubules
Authors: Klebe Robert J. , Grant Anne , Grant George , Ghosh Paramita 
Published: May 2005

AbstractIt has known for many years that MDCK cells blister structures, termed domes. During an examination of the morphbology of a large number of MDCK clones, we found that two stable morphotypes exist in an MDCK cell population namely, dome‐forming and tubule‐forming clones. When maintained at high cell density, tubule‐forming clones displayed large numbers of anastomosing tubules which contained lumens. The frequency of obseration of the tubule forming clones in an MDCK population was 0.7% Tubule‐forming MDCK clones should be useful in studying tubule morphogenesis. While agents that affect protein kinase A actiity increased dome formation, the same agents abolished the formation of tubules in all tubule‐forming clones. In contrast, drugs that stimulate protein kinase C actity (phorbol esters and staurosporine) decreased dome formation and increased tubule morphogenesis in all MDCK morphotyes. Tubules‐forming clones were found to have lower resting levels of cyclic‐AMP and to respond to forskolin stimulation of adenylate cyclase readily. Hence, sigals transmitted by the protein kinase C pathway appear to lead to tubule formation MDCK cells, while signals transmitted through the protein A pathway lead to dome formation. © 1995 Wiley‐Liss, Inc.
Microbial distribution throughout a cellobiose‐supplemented three‐stage laboratory‐scale anaerobic digester
Authors: Howgrave‐Graham Alan G. , Jones L. Robin , James A. Gordon , Terry Sandra J. , Senior Eric , Watson‐Craik Irene A. 
Published: May 2005

AbstractSubstrate and intermediate metabolite degradation were monitored in a three‐stage anaerobic digester fed cellobiose as sole carbon source. The digester vessels were of different sizes and the resultant different dilution rates enabled separation of the trophic groups. Biofilms were allowed to develop on microscope slides suspended at different depths within each vessel and these were examined using phase contrast and fluorescence microscopy. Cell quantification was performed on these and planktonic samples using image analysis. All cellobiose degradation and sulphate reduction and most of the acidogenesis was performed in the first vessel, by an activated sludge‐like population (attached or in flocs). Eighty percent of the methanogenesis and some acetogenesis occurred in the second vessel where populations of attached fluorescent rods and Methanosarcina‐like cells were abundant. The low population levels in the third vessel were responsible for 8% of the total methanogenesis.
Effect of chromium promoter on copper catalysts in ethanol dehydrogenation
Authors: Tu Yau‐Jen , Li Chiuping , Chen Yu‐Wen 
Published: May 2005

AbstractA series of chromium‐promoted copper catalysts with various Cr to Cu molar ratios were prepared with the co‐precipitation method. The promotional effects of chromium on copper catalysts were examined by X‐ray powder diffraction (XRD), nitrous oxide decomposition, and the dehydrogenation reaction of ethanol. The dehydrogenation reaction was carried out in a continuous‐flow microreactor between 523 and 583 K under atmospheric pressure. The results indicated that the promotional effect was dependent on the Cr/Cu molar ratio, and the predominant decay of catalysts in this study was caused by sintering. The catalyst with the Cr/Cu molar ratio of 4/40 has the highest activity and stability. The surrounded well‐dispersed chromia strongly influenced the catalytic properties of copper metal. It also showed that the over‐promotation of a catalyst has a disastrous effect on the total make of product. The ethanol dehydrogenation reaction follows a first‐order reaction, and the kinetics for deactivation can be described by a second‐order expression.
MoO3—Fe2O3 catalysts: Characterization and activity for isopropyl alcohol decomposition
Authors: Bond Geoffrey C. , Halawy Samih A. , Abd El‐Salaam Khalafalla M. , Hassan Ehsan A. , Ragih Hesham M. 
Published: May 2005

AbstractThe vapour‐phase dehydration and dehydrogenation of isopropyl alcohol (IPA) have been carried out over pure MoO3 and Fe2O3, produced by calcination of ammonium heptamolybdate and of iron (III) nitrate respectively, as well as MoO3 mixed with 0·5 and 50 mol% Fe2O3, prepared from the same materials. All catalysts were calcined in air, in the temperature range 200–600°C for 5 h, and were characterized by thermal analysis (TG, DTA), XRD, IR and SBET. Surface areas decreased with increasing calcination temperature, and the catalytic activity of the pure oxides MoO3 and Fe2O3, as well as of MoO3–0.5 mol % Fe2O3, increased with their SBET. The activity of MoO3–50 mol % Fe2O3, which was independent of its SBET, could be attributed to the increased intensity of terminal Mo—O bonds as shown by IR spectra. The activation energies for the decomposition of IPA over catalysts calcined at 250 and 500°C are tabulated.
Methylcyclohexane dehydrogenation on Rh/γ‐Al2O3 catalysts
Authors: Reyes Patricio , Orellana Fresia , Pecchi Gina 
Published: May 2005

AbstractThe influence of the Rh loading on the surface properties and catalytic behaviour of Rh/γ‐Al2O3 catalysts has been studied. The series of catalysts presents differences in metal dispersion, reducibility, surface composition and catalytic activity. All the data reported suggest that the differences in catalytic behaviour in the methylcyclohexane dehydrogenation reaction can be explained in terms of electron‐deficient rhodium clusters, essentially when the metal particle size becomes smaller than 15 Å.
Biocatalysis of chlorophyllase from Phaeodactylum tricornutum in a biphasic organic system
Authors: Khamessan Ali , Kermasha Selim , Ismail Ashraf A. , Marsot Pierre 
Published: May 2005

AbstractThe hydrolytic activity of a partially purified chlorophyllase, obtained from the alga Phaeodactylum tricornutum, was determined in a biphasic organic system using different mixtures of hexane and Tris–HCl buffer solution (20 mmol dm−3, pH 7·5). The most appropriate kinetic parameters were determined for the optimum hydrolytic activity of chlorophyllase including hexane concentration (45%), optimum pH (7·5), time of incubation (7 h), incubation temperature (25°C) and enzyme concentration (10 μg cm−3). The optimum concentrations of magnesium chloride and dithiothreitol, used as activators, were determined to be 4 mmol dm−3 and 5 mmol dm−3, respectively. The results also indicated that diisopropyl fluorophosphate (DIFP) had a mixed competitive–non‐competitive inhibitory effect on chlorophyllase activity. The end‐products of the chlorophyllase hydrolytic reaction were identified and confirmed, using thin‐layer and high‐performance liquid chromatographies, spectrophotometric scanning and Fourier transform infrared spectroscopy.
Influence of pH on the acid‐phase anaerobic digestion of primary sludge
Authors: Elefsiniotis Panagiotis , Oldham William K. 
Published: May 2005

AbstractThis study explored the effect of pH on the acid‐phase anaerobic digestion of primary sludge. Controlled and uncontrolled pH experiments were conducted using two bench‐scale, continuous‐flow reactors having different configurations: a completely mixed reactor (CMR) with clarifier and solids recycling, and an upflow anaerobic sludge blanket (UASB) unit. Results indicate that the specific rates of VFA production and COD solubilization, in either system, were not affected by the variation in pH between 4·3 and 5·2, but at higher pH values (5·9–6·2) a significant decline (by 25–30%) in both parameters was observed. Analysis of the degradation behavior of the three important organic classes (carbohydrates, proteins, and lipids) revealed that each class followed an individual trend with respect to pH changes. Acetic acid was the major end‐product of acidogenic digestion in both reactors, regardless of pH. The percent VFA distribution did not appear to be influenced by pH variation, except for propionic and butyric acids. Besides VFAs, small amounts of formic acid, ethanol, and lactic acid were also formed at all pH values tested.
Evaluation of the performance of immobilized enzyme reactors with michaelis—menten kinetics
Authors: Lortie Robert 
Published: May 2005

AbstractTwo dimensionless models, taking into account the external mass‐transfer, are used to characterize and compare the behaviour of plug flow reactors (PFR) and continuous stirred tank reactors (CSTR). These models need only two parameters, the Damköhler number and the Stanton number, to cover all the range of operating conditions. The conversion and a new dimensionless number, quantifying the use of the enzyme, are calculated for different values of the Damköhler and Stanton numbers.
Synthesis and biological evaluation of some new sulfur‐containing heterocycles as possible antifungal agents
Authors: Hanna Mokhtar A. , Khodeir Mohamed N. , Mashaly Mohamed A. , El‐Shafei Hussain M. 
Published: May 2005

AbstractSome novel sulfonate ester‐containing mono‐, bi‐ and tricyclic fused ring systems (IV, Xa,b, XIa,b, XIV and XV) together with their precursors I, II and III were synthesized with a view to evaluating their efficacy as new sulfur‐containing fungitoxic agents. The structures of the named compounds were established from elemental and spectral analyses.
Catalysis by intermetallic compounds I. A comparison of the catalytic behaviour of CePd3, ZrPd3 and Pd sponge for buta‐1,3‐diene hydrogenation and but‐1‐ene hydroisomerisation
Authors: Bahia Amrik , Winterbottom John M. 
Published: May 2005

AbstractThe hydrogenation of buta‐1,3‐diene and more briefly, the hydroisomerisation of but‐1‐ene catalysed by powdered CePd3, ZrPd3 and Pd sponge has been studied in a fixed bed continuous flow microreactor at 1 bar (101·5 k Pa) total pressure and in the temperature range 45–225°C. The two intermetallics (CePd3, ZrPd3) exhibited greater selectivity for butene formation than palladium, especially at high buta‐1,3‐diene conversions. The superior selectivity of the intermetallics was demonstrated further under the more demanding conditions, whereby but‐1‐ene was added to the feed buta‐1,3‐diene in the ratio C4H8/C4H6 = 24. The kinetics and apparent energies of activation were determined for the hydrogenation and isomerisation reactions. In the case of buta‐1,3‐diene hydrogenation, the kinetics suggest that for Pd sponge, hydrogen and buta‐1,3‐diene adsorb on similar sites, whereas in the case of the intermetallics different sites may be involved for hydrogen and buta‐1,3‐diene adsorption, which may result from palladium—metal oxide interactions. In the case of but‐1‐ene isomerisation, double bond migration appears to occur via addition–abstraction mechanisms on all three catalysts but in the case of the intermetallics hydrogenation and isomerisation involve different rate determining steps.
A simple model for estimating protein solubility in aqueous polymer solutions
Authors: Yu Ming , de Swaan Arons Jakob , Smit Jan A. M. 
Published: May 2005

AbstractA simple scaling analysis of protein solubility in semi‐diluted polymer aqueous solutions was derived based on the recent theoretical development of Abbott et al.1 on the interactions between protein spheres and entangled polymer coils and the experimental observations of Atha and Ingham2 on the polymer‐induced protein precipitation. Both the hard‐sphere nature of the protein and the flexibility of the polymer coils have been taken into account in the model. The experimental data can be fitted by using this model with physically reasonable values of the exponent. This approach may be useful in estimating protein solubilities in water in the presence of polymer from limited and usually costly experimental data.
Solubilization of bituminous and lignite coals by chemically and biologically synthesized surfactants
Authors: Polman J. Kevin , Miller Karen S. , Stoner Daphne L. , Breckenridge Cynthia R. 
Published: May 2005

AbstractTween 80 (polyoxyethylene sorbitan monooleate), Triton X‐100 (nonaethylene glycol octylphenol ether), and SDS (sodium dodecyl sulfate) solubilized several components of Mississippi Wilcox lignite and Illinois No. 6 bituminous coal. Tween 80 extraction of alkali‐soluble Ugljevik lignite resulted in an increase in hydrogen content and decreases in the nitrogen and sulfur contents of undissolved coal solids. Biosurfactant‐containing cell‐free extracts of Bacillus licheniformis solubilized a 53 000 Da coal component of Mississippi Wilcox lignite. The results suggest that solubilization of coal organic components by chemically‐ and biologically‐synthesized surfactants has potential in terms of upgrading coals.
Combined bioreaction and separation in centrifugal fields using zonal rotors
Authors: Setford Steven J. , Barker Phillip E. 
Published: May 2005

AbstractCombined biosynthesis and product separation has been successfully performed for the first time using a zonal centrifugal bioreactor–separator. The biosynthesis of dextran polymer from sucrose using the dextransucrase enzyme was investigated in order to evaluate bioreactor performance. The bioreactor consisted of a bowl, fitted with a Reorienting gradient rotor which facilitated substrate and enzyme loading and the reproducible unloading of solutions from the system. This allowed the distribution of substrate, enzyme and product materials in the bowl at the end of each trial to be accurately determined. Studies have indicated that combined bioreaction–separation is possible using this system. However, viscosity build‐up in the bioreactor must be minimised in order to increase the yield of polymer product per unit time and improve product separation.
Stability of a mineral membrane ultrafiltration reactor for peptide hydrolysis of hemoglobin
Authors: Sannier Frédéric , Piot Jean‐Marie , Dhulster Pascal , Guillochon Didier 
Published: May 2005

AbstractFactors involved in the activity decay of an ultrafiltration reactor during the hydrolysis of hemoglobin by pepsin were studied. Biochemical and hydrodynamic parameters were assessed. The product of hydrolysis showed no inhibitory effect. Autolysis and mechanical damage of pepsin were limited by the presence of hemoglobin. Activity decay was mainly a result of the leakage of pepsin through the membrane. Electrostatic charges carried by either hemoglobin or pepsin were involved in the permeation process.
Comparative sorption kinetic studies of phenolic compounds on fly ash and impregnated fly ash
Authors: Singh Binay K. , Rawat Narendra S. 
Published: May 2005

AbstractThe factors affecting the rate processes involved in the removal of phenolic compounds, e.g. initial phenol concentration, particle size, impregnation of fly ash (IFA), pH and temperature have been studied. The removal rate of phenols varied in the order p‐nitrophenol m‐nitrophenol > o‐nitrophenol > p‐cresol > phenol > m‐cresol > o‐cresol. The process followed first order rate kinetics. The sorption data generally fit the Lagergren equation and the intraparticle diffusion rate equation from which adsorption rate constants, diffusion rate constants and diffusion coefficients were determined. Intraparticle diffusion was found to be the rate‐limiting step. These kinetic parameters were compared for various phenols under different conditions using fly ash (FA) and impregnated fly ash (IFA).
A description of three methods for the determination of the initial inert particulate chemical oxygen demand of wastewater
Authors: Orhon Derin , Artan Nazik , Ateş Esra 
Published: May 2005

AbstractThree different methods are described for the determination of the initial inert particulate organics, measured in terms of COD. The methods involve experimental procedures using batch reators and are designed to differentiate residual particulate products generated by metabolic activities during the treatment processes. In the first method, the final threshold value of the particulate COD is monitored in an aerated batch reactor fed by the initial total COD. The second method uses the threshold values of the total and soluble COD in two parallel batch reactors, one fed with unfiltered and the other with filtered wastewater. The third method involves running three batch reactors, two with the wastewater to be studied and the thired with glucose. One method has been experimentally tested to assess the inert particulate fractions of domestic and textile wastewaters.
Optimization of experimental conditions for the catalytic oxidation of furfural to furoic acid
Authors: Verdeguer Philippe , Merat Nadine , Rigal Luc , Gaset Antoine 
Published: May 2005

AbstractOxidation of furfural in a stream of oxygen in aqueous alkaline medium in the presence of a lead–platinum catalyst leads to the formation of furan 2‐carboxylic acid. The influence of five factors was studied using a Doehlert matrix. The analysis of the areas of responses allowed the optimal operating conditions to be determined: platinum metal mass/furfural mass introduced × 100:1·7%; lead diacetate mass/platinum on carbon mass: 20%; initial furfural concentration 0·8 M; temperature 55°C. After 1 h of reaction, the whole of the furfural is then selectively transformed into furoic acid.
Measurement of bound water in waste activated sludge: Use of the centrifugal settling method
Authors: Lee Duu‐Jong 
Published: May 2005

AbstractThe feasibility of employing a centrifugal settling method for measuring the bound water content in waste activated sludge was investigated. The results demonstrated that, for such highly compressible sludge, the centrifugal settling test can only provide information about the cake compressibility and the method proposed by Matsuda and colleagues fails. A method combining vacuum filtration tests and centrifugal settling tests for estimating the bound water content is proposed and compared with expression tests. The agreement was close.
A mathematical model of microalgal growth in light‐limited chemostat culture
Authors: Grima E. Molina , Camacho F. García , Pérez J. A. Sánchez , Sevilla J. M. Fernández , Fernández F. G. Acién , Gómez A. Contreras 
Published: May 2005

AbstractA mathematical model for light‐limited growth of a continuous microalgal culture is proposed. Average light intensity inside the photobioreactor was calculated, taking light attenuation by algae into account. The biomass absorption coefficient was determined by means of two new parameters, the pigment‐free biomass, YB, and the total pigment absorption, Yp (absorption coefficient normalized to total pigment content). The model reproduced the steady states reached and the dynamic behaviour of the system when the dilution rate was changed.
Preparation of membrane‐immobilised enzymes for phenol decomposition
Authors: Bodzek Michał , Bohdziewicz Jolanta , Kowalska Małgorzata 
Published: May 2005

AbstractA method for the preparation of membranes with immobilised enzymes for the biological degradation of phenols is described. In the first stage, an enzymatic fraction from bacterial strains has been isolated. The enzyme membranes were obtained by ultrafiltration of protein solution through a membrane support made of non‐cellulose polymers. All enzymes were adsorbed onto the membrane surface. The enzyme membranes were found to degrade 70–80% of the phenol during single dead‐end ultrafiltration at a pressure of 1 × 105−3 × 105 Pa. The retention coeffcient of the ultrafiltration process also amounted to 70–80%.