bluuebunny/crossref_metadata_2025_split huggingface dataset:
A review of bioremediation and natural attenuation of MTBE
Authors: Davis Lawrence C. , Erickson Larry E. 
Published: October 2004

AbstractMethyl tert‐butyl ether (MTBE) has been the focus of much attention because it is used in large amounts and was reportedly relatively recalcitrant to bioremediation or natural attenuation. Beginning with a few papers a decade ago, evidence has been presented that, in fact, under suitable conditions it is amenable to bioremediation. Many species from widely disparate microbial genera are able to consume it either as a sole carbon source or as a cometabolite. Optimal conditions differ from site to site. Both aerobic and anaerobic conditions may permit MTBE degradation, with a range of electron acceptors, from oxygen through Fe(III), Mn(IV), sulfate, nitrate, and methanogenesis. MTBE metabolism in the vadose zone can be highly active. The published literature suggests that natural populations are adapting to MTBE, and reported rates of biodegradation appear to be larger in the more recent literature. Plants may serve as efficient conduits to withdraw MTBE from the wet subsurface, releasing it to the atmosphere or the vadose zone, where it may be metabolized or diffuse into the atmosphere where it is quickly photodegraded. The major remaining issues are the time required to attain specified criteria of cleanup or whether augmentation is necessary for effective remediation. © 2004 American Institute of Chemical Engineers Environ Prog, 23: 243–252, 2004
Degradation of chlorinated organics by membrane‐immobilized nanosized metals
Authors: Meyer D.E. , Wood K. , Bachas L.G. , Bhattacharyya D. 
Published: October 2004

AbstractThe use of electronegative metals, such as Fe, has been extensively studied for the treatment of groundwater containing toxic chlorinated organics. Much of the recent work has been focused on the use of nanoscale particles with diameters from 2 to 100 nm. This work examines the use of bimetallic (Fe/Ni) nanoscale particles immobilized in a cellulose acetate domain for the destruction of trichloroethylene (TCE). The organic/inorganic hybrid film is synthesized using phase inversion with sodium borohydride reduction. The resulting nanoparticles have an average diameter of 24 nm. Using a small quantity of membrane‐immobilized metal (31 mg total, Fe:Ni = 4:1), it was possible to achieve over a 75% reduction in TCE levels in 4.25 h, with ethane as the only observable product. For shorter reaction times (<2 h), traces of cis‐ and trans‐DCE could be extracted from the baseline of the MS chromatogram. For longer reaction times, products of coupling reactions (butane and hexane) were observed. This corresponds to a surface‐area–normalized pseudo–first‐order rate constant, kSA, for the immobilized system of 3.7 × 10−2 L m−2 h−1. Analysis of the aqueous phase for metal content showed minimal leaching of the metals into the surrounding solution during treatment. Because various combinations of membranes containing immobilized metal nanoparticles can be achieved using the synthesis techniques presented, a more versatile platform for the application of zero‐valent treatment is possible. © 2004 American Institute of Chemical Engineers Environ Prog, 23: 232–242, 2004
Modelling Approach for Planar Self‐Breathing PEMFC and Comparison with Experimental Results
Authors: Schmitz A. , Ziegler C. , Schumacher J. O. , Tranitz M. , Fontes E. , Hebling C. 
Published: October 2004

AbstractThis paper presents a model‐based analysis of a proton exchange membrane fuel cell (PEMFC) with a planar design as the power supply for portable applications.The cell is operated with hydrogen and consists of an open cathode side allowing for passive, self‐breathing, operation. This planar fuel cell is fabricated using printed circuit board (PCB) technology. Long‐term stability of this type of fuel cell has been demonstrated.A stationary, two‐dimensional, isothermal, mathematical model of the planar fuel cell is developed. Fickian diffusion of the gaseous components (O2, H2, H2O) in the gas diffusion layers and the catalyst layers is accounted for. The transport of water is considered in the gaseous phase only. The electrochemical reactions are described by the Tafel equation. The potential and current balance equations are solved separately for protons and electrons. The resulting system of partial differential equations is solved by a finite element method using FEMLAB (COMSOL Inc.) software.Three different cathode opening ratios are realized and the corresponding polarization curves are measured. The measurements are compared to numerical simulation results. The model reproduces the shape of the measured polarization curves and comparable limiting current density values, due to mass transport limitation, are obtained.The simulated distribution of gaseous water shows that an increase of the water concentration under the rib occurs. It is concluded that liquid water may condense under the rib leading to a reduction of the open pore space accessible for gas transport. Thus, a broad rib not only hinders the oxygen supply itself, but may also cause additional mass transport problems due to the condensation of water.
On the Stability of Selected Monomeric and Polymeric Aryl Sulfonic Acids on Heating in Water (Part 1)
Authors: Vogel C. , Meier‐Haack J. , Taeger A. , Lehmann D. 
Published: October 2004

AbstractA number of low molecular weight sulfonated aromatic compounds: carboxamides, imides, sulfonamides, as well as sulfonated polymers; aramides and poly(styrene‐p‐sulfonic acid), were tested for their stability on heating in water and dilute acid to temperatures ranging from 130–200 °C. Desulfonation was observed with some compounds. Sulfonamide linkages were found to be stable, while carboxamide linkages and phthalimides were not.
Quetiapine has a direct effect on the negative symptoms of schizophrenia
Authors: Tandon Rajiv 
Published: October 2004

AbstractSecond‐generation ‘atypical’ antipsychotics appear to be more effective than first‐generation ‘typical’ antipsychotics in improving negative symptoms in schizophrenia; it is unclear, however, if this greater improvement represents a direct beneficial effect or is mediated indirectly by an antidepressant effect or the absence of extrapyramidal symptoms (EPS). To address this issue with reference to quetiapine (‘Seroquel’), data were evaluated from four randomized, controlled clinical studies involving 1106 patients employing a path analysis model. The total effect of quetiapine on negative symptoms was measured using the Scale for Assessment of Negative Symptoms (SANS) total score. Indirect effects on negative symptoms via positive, depressive and EPS were assessed using appropriate instruments. Effect sizes were calculated by path analysis for the difference between treatment groups in change from baseline to endpoint in SANS total score. Analysis confirmed that quetiapine produced a greater overall improvement in negative symptoms than placebo (effect size 1.96); this was explained by a significant direct effect (p = 0.001; 44.2% of total improvement), and a secondary effect of improved positive symptoms (p < 0.001; 47.5% of total improvement), but was not a consequence of changes in depressive symptoms or EPS. Within the constraints of the path analysis methodology, these results indicate that quetiapine has a substantial direct effect on improving the negative symptoms of schizophrenia. Copyright © 2004 John Wiley & Sons, Ltd.
Corneal epithelial cell growth over tethered‐protein/peptide surface‐modified hydrogels
Authors: Jacob Jean T. , Rochefort James R. , Bi Jingjing , Gebhardt Bryan M. 
Published: October 2004

AbstractIn this study, we investigated the corneal epithelial cell growth rate and adhesion to novel hydrogels with (1) extracellular matrix proteins [fibronectin, laminin, substance P, and insulin‐like growth factor‐1 (IGF‐1)] and (2) peptide sequences [RGD and fibronectin adhesion‐promoting peptide (FAP)] tethered to their surface on poly(ethylene glycol) (PEG) chains. The growth rate to confluence of primary rabbit cornea epithelial cells was compared for plain polymethacrylic acid‐co‐hydroxyethyl methacrylate (PHEMA/MAA) hydrogels, PHEMA/MAA hydrogels coated with extracellular matrix proteins or peptides, and PHEMA/MAA hydrogels with tethered extracellular matrix proteins or peptides on the surface. The development of focal adhesions by the epithelial cells grown on the surfaces was determined by F‐actin staining. Little to no epithelial cell growth occurred on the plain hydrogel surfaces throughout the 15‐day culture period. Of the coated hydrogels, only the fibronectin‐coated surfaces showed a significant increase in cell growth compared to plain hydrogels (p < 0.009). However, even these surfaces reached a maximum of only 20% confluence. Laminin, fibronectin adhesion‐promoting peptide (FAP), and fibronectin/laminin (1:1) tether‐modified hydrogels all achieved 100% confluence by the end of the culture period, although the rates at which confluence was reached differed. F‐actin staining showed that focal adhesions were formed for the laminin, FAP, and fibronectin/laminin tether‐modified surfaces. The results support the hypothesis that tethering certain extracellular matrix proteins and/or peptides to the hydrogel surface enhances epithelial cell growth and adhesion, compared with that seen for protein‐coated or plain hydrogel surfaces. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 72B: 198–205, 2005
Effects of sodium hypochlorite gel and sodium hypochlorite solution on dentin bond strength
Authors: Arias Vanessa G. , Bedran‐de‐Castro Ana Karina B. , Pimenta Luiz André 
Published: October 2004

AbstractThe aim of this study was to determine the effect of 10% NaOCl gel and 10% NaOCl solution on dentin bond strengths of four adhesive systems. One hundred eighty bovine incisors were ground to achieve a flat polished surface, then divided into 12 groups: Gluma One Bond [G1 ‐ control; G2 ‐ NaOCl solution; G3 ‐ NaOCl gel]; Prime & Bond 2.1 [G4 ‐ control; G5 ‐ NaOCl solution; G6 ‐ NaOCl gel]; Single Bond [G7 ‐ control; G8 ‐ NaOCl solution; G9 ‐ NaOCl gel]; Prime & Bond NT [G10 ‐ control; G11 ‐ NaOCl solution; G12 ‐ NaOCl gel]. Dentin was etched, rinsed, and blot dried. For the experimental groups, after acid etching, 10% NaOCl solution or 10% NaOCl gel was applied for 60 s, rinsed, and blot dried. Composite resin was inserted and light cured. Shear bond strengths were tested with a crosshead speed of 0.5mm/min. The mean values MPa (SD) were analyzed with two‐way ANOVA and Tukey's tests (α < 0.01). Ten percent NaOCl solution significantly increased Gluma One Bond strength. No effect was observed for the other adhesives. The 10% NaOCl gel did not affect bond strengths. Ten percent NaOCl gel was less effective on collagen removal as compared to 10% NaOCl solution. The influence of collagen removal on bond strength is dependent on adhesive system, where both the solvent and the monomer can influence the results. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 72B: 339–344, 2005
An oxidative stress mechanism mediates chelerythrine‐induced heparin‐binding EGF‐like growth factor ectodomain shedding
Authors: Kim Jayoung , Lin Jianqing , Adam Rosalyn M. , Lamb Carolyn , Shively Sharon Baughman , Freeman Michael R. 
Published: October 2004

AbstractRegulated shedding of cell surface proteins is a mechanism for rapid activation of autocrine and paracrine signaling. Here we report that chelerythrine, a protein kinase C (PKC) inhibitor that possesses a variety of biological functions, is a potent inducer of heparin‐binding epidermal growth factor‐like growth factor (HB‐EGF) shedding from the cell surface. Chelerythrine induced a time‐ and dose‐dependent shedding of an HB‐EGF–alkaline phosphatase (HB‐EGF‐AP) fusion protein expressed in MC2 rat prostate epithelial cells. The soluble form of HB‐EGF‐AP bound to heparin and exhibited potent biological activity as measured by DNA synthesis assay. Chelerythrine‐induced HB‐EGF shedding was metalloproteinase‐(MMP‐) mediated because specific MMP antagonists inhibited shedding by ≥60%. Chelerythrine stimulated production of reactive oxygen species, and antioxidants prevented chelerythrine‐induced HB‐EGF shedding, suggesting that the production of intracellular peroxides is necessary for this event. Consistent with this possibility, antioxidant‐ and MMP‐inhibitable shedding was also demonstrated when hydrogen peroxide was used as an inducer. Although JNK/SAPK and p38 MAPK pathways were activated by chelerythine, these signaling mechanisms were not required to mediate the shedding event. However, JNK signaling was involved in chelerythrine‐stimulated apoptosis. Our results suggest that HB‐EGF shedding induced by chelerythrine is mediated predominantly via the production of reactive oxygen species. © 2004 Wiley‐Liss, Inc.
Regulation of the GATA3 promoter by human T‐cell lymphotropic virus type I Tax protein
Authors: Gilli Simone Cristina Olenscki , Salles Tereza Sueko Ide , Saad Sara Teresinha Olalla 
Published: October 2004

AbstractThe Human T‐cell leukemia virus type I (HTLV‐I) non‐structural protein Tax plays a crucial role in cellular transformation. It activates the transcription factors of various cellular genes and interacts with cellular proteins. There is limited data available on the interaction between specific T‐cell transcription factor GATA3 and Tax. Implications for the significance of GATA3 in T‐cell development and function, T helper2 (Th2) differentiation, and a role of GATA3 during the immune response have been reported. To determine the effect of the Tax protein on GATA3 gene expression, we investigated the interaction between this protein and the GATA3 promoter and repressor regions. Results demonstrated an interaction between Tax and the GATA3 promoter via the transcription factor Sp1 and a role for Tax in the negative regulation of GATA3 expression, through its interaction with the repressor ZEB. This interaction may be involved in the pathophysiology of adult T‐cell leukemia/lymphoma (ATL) and tropical spastic paraparesis/HTLV‐I‐associated myelopathy (TSP/HAM). © 2004 Wiley‐Liss, Inc.
Secretory and basal cells of the epithelium of the tubular glands in the male Mullerian gland of the caecilian Uraeotyphlus narayani (Amphibia: Gymnophiona)
Authors: George Jancy M. , Smita Matthew , Kadalmani Balamuthu , Girija Ramankutty , Oommen Oommen V. , Akbarsha Mohammad A. 
Published: October 2004

AbstractCaecilians are exceptional among the vertebrates in that males retain the Mullerian duct as a functional glandular structure. The Mullerian gland on each side is formed from a large number of tubular glands connecting to a central duct, which either connects to the urogenital duct or opens directly into the cloaca. The Mullerian gland is believed to secrete a substance to be added to the sperm during ejaculation. Thus, the Mullerian gland could function as a male accessory reproductive gland. Recently, we described the male Mullerian gland of Uraeotyphlus narayani using light and transmission electron microscopy (TEM) and histochemistry. The present TEM study reports that the secretory cells of both the tubular and basal portions of the tubular glands of the male Mullerian gland of this caecilian produce secretion granules in the same manner as do other glandular epithelial cells. The secretion granules are released in the form of structured granules into the lumen of the tubular glands, and such granules are traceable to the lumen of the central duct of the Mullerian gland. This is comparable to the situation prevailing in the epididymal epithelium of several reptiles. In the secretory cells of the basal portion of the tubular glands, mitochondria are intimately associated with fabrication of the secretion granules. The structural and functional organization of the epithelium of the basal portion of the tubular glands is complicated by the presence of basal cells. This study suggests the origin of the basal cells from peritubular tissue leukocytes. The study also indicates a role for the basal cells in acquiring secretion granules from the neighboring secretory cells and processing them into lipofuscin material in the context of regression of the Mullerian gland during the period of reproductive quiescence. In these respects the basal cells match those in the epithelial lining of the epididymis of amniotes. J. Morphol. 262:760–769, 2004. © 2004 Wiley‐Liss, Inc.
An improved experimental and regression methodology for sorption isotherms
Authors: Quirijns Elisabeth J , van Boxtel Anton JB , van Loon Wilko KP , van Straten Gerrit 
Published: October 2004

AbstractSorption isotherms of corn and starch cylinders with immobilised catalase are experimentally determined at different temperatures for use in drying models in optimal control studies. This application of the sorption isotherm requires an accurate prediction of the sorption data at different temperatures for the low water activity range. The GAB equation is used for the prediction of the sorption isotherms. Two major problems are encountered by employing standard procedures, ie prediction of sorption at aw < 0.11 and sensitivity of the GAB parameters to the applied data range. An improved methodology is developed, consisting of extending the standard experimental procedure with additional data points in the low water activity range and changing the criterion in the regression procedure in the sum of squares, which is weighed by the variance of the experimental data. The new methodology leads to accurate, consistent and physically relevant parameters of the GAB equation, which are independent of the applied data range in the regression analysis and which result in accurate predictions of the sorption behaviour at low water activity. The sorption data at different temperatures at low water activity can be predicted in the best way with parameters obtained after direct regression based on weighed SSQ. Copyright © 2004 Society of Chemical Industry
Accelerated storage and isothermal microcalorimetry as methods of predicting carrot juice shelf‐life
Authors: Alklint Charlotte , Wadsö Lars , Sjöholm Ingegerd 
Published: October 2004

AbstractThe possibility of predicting the shelf‐life of pasteurized carrot juice by isothermal microcalorimetry or change in pH was investigated and compared with traditional plate count results. A small increase in thermal power (2 µW), maximal increase of and acceleration of thermal power all gave rapid, well‐correlated results for the shelf‐life, as did pH, during accelerated storage. The effect of accelerated storage (17 °C) on the microbial flora of pasteurized carrot juice was also compared with the flora from storage at 8 °C, and it was found that accelerated storage is feasible for the rapid evaluation of shelf‐life, but that the microbial flora in the spoilt juice will be different. Copyright © 2004 Society of Chemical Industry
Free‐radical scavenging activity of wormwood (Artemisia absinthium L) extracts
Authors: Canadanovic‐Brunet Jasna M , Djilas Sonja M , Cetkovic Gordana S , Tumbas Vesna T 
Published: October 2004

AbstractIn an effort to discover new antioxidant natural compounds, wormwood (Artemisia absinthium L) an aromatic‐bitter herb, was screened. The sequential extraction was realized with five solvents of different polarities (70% methanol, petroleum ether, chloroform, ethyl acetate, n‐butanol). The antioxidative activity was tested by measuring their ability to scavenge stable 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical and reactive hydroxyl radical during the Fenton reaction trapped by 5,5‐dimethyl‐1‐pyrroline‐N‐oxide (DMPO), using electron spin resonance (ESR) spectroscopy. Results demonstrated that the antiradical and antioxidative activity depend on the type and concentration of applied extracts and increased in the order ethyl acetate > methanol > n‐butanol > chloroform > petroleum ether > remaining water extracts. The investigation showed that the antiradical activity increased with increasing concentration of all extracts. The high contents of total phenolic compounds (25.6 mg g−1) and total flavonoids (13.06 mg g−1) indicated that these compounds contribute to the antiradical and antioxidative activity. In a model system, the formation of o‐semiquinone radicals from quercetin and chlorogenic acid was obtained to prove the mechanism (hydrogen donating and/or one‐electron reduction) of free‐radical scavenging activity. Copyright © 2004 Society of Chemical Industry
Effect of the fungal protease EPg222 on proteolysis and texture in the dry fermented sausage ‘salchichón’
Authors: Benito María J , Rodríguez Mar , Córdoba María G , Andrade María J , Córdoba Juan J 
Published: October 2004

AbstractProteolytic activity of the fungal protease EPg222 and its effect on the texture of the dry fermented sausage ‘salchichón’, which has a long ripening process, was assayed. Samples with enzyme added showed a significant reduction of myofibrillar protein concentration during the ripening period, compared with a control, and proteolytic activity of the enzyme led to a higher accumulation of non‐protein and ‐amino acid nitrogen. Analysis of volatile compounds in ripened dry fermented sausages revealed that only in EPg222 batches were branched compounds derived from amino acids catabolism detected that are associated with the flavour of dry cured meat products. The texture profile analysis showed reduction in hardness, gumminess and chewiness values in treated compared with control sausages. The effect of this enzyme could be of great interest in stimulating proteolysis, in flavour development and in reducing the hardness of dry fermented sausages produced by a long ripening process. Copyright © 2004 Society of Chemical Industry
Variation in 1‐fructo‐exohydrolase (1‐FEH) and 1‐kestose‐hydrolysing (1‐KH) activities and fructo‐oligosaccharide (FOS) status in onion bulbs. Influence of temperature and storage time
Authors: Benkeblia Noureddine , Onodera Shuichi , Shiomi Norio 
Published: October 2004

AbstractEffects of storage temperature and duration on 1‐fructo‐exohydrolase (1‐FEH) and 1‐kestose‐hydrolysing (1‐KH) activities and trisaccharide (Tri) and fructo‐oligosaccharide (FOS) status in onion bulbs var Tenshin kept for 24 weeks at 10 and 20 °C were investigated. 1‐FEH activity peaked sharply after 10 weeks and seemed to be triggered by a decrease in sucrose content. 1‐KH activity increased during the first 8 weeks and remained stable during the last 8 weeks. Contents of Tri, FOS and total FOS decreased abruptly during the first 8 weeks; however, at 10 °C, contents of Tri, FOS (DP 3–12) and total FOS were lower than those at 20 °C. The consumption rate of fructo‐oligosaccharides also appeared to be higher at 20 °C than at 10 °C, despite the slight degradation in activities observed at this low temperature. 1‐FEH seems to be under the control of a triggering signal which induces its activity, and sucrose seems to be this biochemical signal which initiates dormancy release and the onset of sprouting, as found previously. Thus changes in carbohydrates seem to be a strong indicator of the end of the dormant state of the bulb and the beginning of the sprouting period. Copyright © 2004 Society of Chemical Industry