bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antisense glutaminase inhibition modifies the O‐GlcNAc pattern and flux through the hexosamine pathway in breast cancer cells
Authors: Donadio Ana C. , Lobo Carolina , Tosina Marta , de la Rosa Vanessa , Martín‐Rufián Mercedes , Campos‐Sandoval José A. , Matés José M. , Márquez Javier , Alonso Francisco J. , Segura Juan A. 
Published: July 2007

AbstractGlutamine behaves as a key nutrient for tumors and rapidly dividing cells. Glutaminase is the main glutamine‐utilizing enzyme in these cells, and its activity correlates with glutamine consumption and growth rate. We have carried out the antisense L‐type glutaminase inhibition in human MCF7 breast cancer cells, in order to study its effect on the hexosamine pathway and the pattern of protein O‐glycosylation. The antisense mRNA glutaminase expressing cells, named ORF19, presented a 50% lower proliferation rate than parental cells, showing a more differentiated phenotype. ORF19 cells had an 80% reduction in glutamine:fructose‐6‐P amidotransferase activity, which is the rate‐limiting step of the hexosamine pathway. Although the overall cellular protein O‐glycosylation did not change, the O‐glycosylation status of several key proteins was altered. O‐glycosylation of O‐GlcNAc transferase (OGT), the enzyme that links N‐acetylglucosamine to proteins, was fivefold lower in ORF19 than in wild type cells. Inhibition of glutaminase also provoked a 10‐fold increase in Sp1 expression, and a significant decrease in the ratio of O‐glycosylated to total protein for both Sp1 and the Rpt2 proteasome component. These changes were accompanied by a higher Sp1 transcriptional activity. Proteome analysis of O‐glycosylated proteins permitted the detection of two new OGT target proteins: the chaperonin TCP‐1 θ and the oncogene Ets‐related protein isoform 7. Taken together, our results support the hexosamine pathway and the O‐glycosylation of proteins being a sensor mechanism of the nutritional and energetic states of the cell. J. Cell. Biochem. 103: 800–811, 2008. © 2007 Wiley‐Liss, Inc.
Loss of ERE binding activity by estrogen receptor‐α alters basal and estrogen‐stimulated bone‐related gene expression by osteoblastic cells
Authors: Rudnik Volha , Sanyal Arunik , Syed Farhan A. , Monroe David G. , Spelsberg Thomas C. , Oursler Merry Jo , Khosla Sundeep 
Published: July 2007

AbstractEstrogen receptor (ER)‐α can signal either via estrogen response element (ERE)‐mediated pathways or via alternate pathways involving protein–protein or membrane signaling. We previously demonstrated that, as compared to wild type (WT) controls, mice expressing a mutant ER‐α lacking the ability to bind EREs (non‐classical estrogen receptor knock‐in (NERKI)) display significant impairments in the skeletal response to estrogen. To elucidate the mechanism(s) underlying these in vivo deficits, we generated U2OS cells stably expressing either WT ER‐α or the NERKI receptor. Compared to cells transfected with the control vector, stable expression of ER‐α, even in the absence of E2, resulted in an increase in mRNA levels for alkaline phosphatase (AP, by 400%, P < 0.01) and a decrease in mRNA levels for insulin growth factor‐I (IGF‐I) (by 65%, P < 0.001), with no effects on collagen I (col I) or osteocalcin (OCN) mRNA levels. By contrast, stable expression of the NERKI receptor resulted in the suppression of mRNA levels for AP, col I, OCN, and IGF‐I (by 62, 89, 60, and 70%, P < 0.001). While E2 increased mRNA levels of AP, OCN, col I, and IGF‐I in ER‐α cells, E2 effects in the NERKI cells on AP and OCN mRNA levels were attenuated, with a trend for E2 to inhibit col I mRNA levels. In addition, E2 had no effects on IGF‐I mRNA levels in NERKI cells. Collectively, these findings indicate that ERE signaling plays a significant role in mediating effects of estrogen on osteoblastic differentiation markers and on IGF‐I mRNA levels. J. Cell. Biochem. 103: 896–907, 2008. © 2007 Wiley‐Liss, Inc.
Removal of Congo red from aqueous solution using a chitosan/organo‐ montmorillonite nanocomposite
Authors: Wang Li , Wang Ai‐qin 
Published: July 2007

AbstractTo further improve the adsorption capacity of chitosan (CTS), a series of novel chitosan/organo‐montmorillonite nanocomposites (CTS/OMMT) were synthesized and the adsorption abilities for Congo red (CR) investigated in this study. The nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction analysis (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the results indicated that an exfoliated nanostructure was formed in CTS/OMMT nanocomposites. Compared with the adsorption capacity of OMMT (192.4 mg g−1), CTS/OMMT with an amount of cetyltrimethylammonium bromide equal to 0.75 CEC of MMT and molar ratio of CTS to OMMT of 1:10 exhibited the higher adsorption capacity (290.8 mg g−1). The adsorption behaviours of OMMT and CTS/OMMT showed that the adsorption kinetics and isotherms were in good agreement with a pseudo‐second‐order equation and the Langmuir equation, respectively. The IR spectra revealed that a chemical interaction occurred between CTS/OMMT and CR. The adsorption capacity of CTS/OMMT nanocomposite was higher than that of other absorbents; this study suggested that the CTS/OMMT nanocomposite could be used as an adsorbent to remove CR dye from aqueous solution. Copyright © 2007 Society of Chemical Industry
Electrolytic reduction improves treatability of humic acids containing water streams
Authors: Satyawali Yamini , Van de Wiele Tom , Saveyn Hans , Van der Meeren Paul , Verstraete Willy 
Published: July 2007

AbstractBACKGROUND:An understanding of the structure of humic acids is essential for their degradation or physical removal from wastewaters. This work aims at targeting the reactivity of these molecules by modifying their properties. Structural alterations were carried out by electrolytically reducing the solution containing humic acid in an electrolytic cell to convert them into less polar structures.RESULTS:Overall it was observed that electrolytic reduction of humic acids strongly facilitated their further treatability. First, the reduced forms of humic acids exhibited improved adsorption on activated carbon. For 1 kW h of electrical energy consumed during electrolytic reduction, the additional chemical oxygen demand (COD) adsorbed was 60 g for a synthetic humic acid solution. Similarly, the additional COD adsorbed (kW h)−1 was found to be 35 g and 112 g for humic acid‐rich effluent and landfill leachate, respectively. In comparison with non‐reduced control samples, a 200‐fold decrease in the chloroform formation was observed when electrolytically reduced drinking water samples were supplemented with a chlorine dosage of 150 mg L−1. Moreover, an enhanced membrane flux was obtained with electrically reduced samples, indicating their improved membrane filterability.CONCLUSION:The electrolyzed humus species were characterized by analyzing their surface tension and particle size. This work addresses an alternative technology for the treatment of water streams containing humic acids. Copyright © 2007 Society of Chemical Industry
Stabilized production of highly concentrated bioethanol from fermentation broths by Zymomonas mobilis by pervaporation using silicone rubber‐coated silicalite membranes
Authors: Ikegami Toru , Negishi Hideyuki , Yanase Hideshi , Sakaki Keiji , Okamoto Masayoshi , Koura Nobuyuki , Sano Tsuneji , Haraya Kenji , Yanagishita Hiroshi 
Published: July 2007

AbstractSince pervaporation performance of ethanol‐permselective silicalite membrane, which is an aluminum‐free hydrophobic zeolite, in the separation of fermentation broths by yeast are negatively affected by succinic acid, the potential of pervaporation using silicone rubber‐coated silicalite membranes of ethanol fermentation broths, not containing succinic acid, by Zymomonas mobilis was investigated for the reliable production of concentrated bioethanol. In the separation of fermentation broths, the pervaporation performance was influenced by nutrients used for the preparation of fermentation broths. In the separation of a broth prepared with yeast extract, pervaporation performance was greatly compromised by accumulation of a substance(s) having an ultraviolet absorption maximum at approximately 260 nm not only in total flux, but also in permeate ethanol concentration compared to the separation of binary ethanol/water mixtures. When supplying a prepared broth with corn steep liquor without the accumulation of a substance(s) having an ultraviolet absorption maximum at approximately 260 nm, the permeate ethanol concentration did not decrease. Treating the prepared broth with activated carbon was effective in restraining the decrease in total flux. Pervaporation performance is also deteriorated by the adsorption of lactic acid contained in corn steep liquor onto the silicalite crystals. In the separation of ternary mixtures of ethanol/water/lactic acid, accomplished by adjusting the ternary mixtures to pH > 5, more than 90% of the permeation flux in the separation of binary ethanol/water mixtures was obtained, and the permeate ethanol concentration was comparable to that obtained in the separation of binary mixtures. For stably performing pervaporation, it is important to prepare ethanol fermentation broths by Zymomonas mobilis in which lactic acid concentration is as low as possible. Copyright © 2007 Society of Chemical Industry
Towards the design of a scalable and commercially viable technique for plasmid purification using a methacrylate monolithic stationary phase
Authors: Danquah Michael K , Forde Gareth M 
Published: July 2007

AbstractA monolithic stationary phase was prepared via free radical co‐polymerization of ethylene glycol dimethacrylate (EDMA) and glycidyl methacrylate (GMA) with pore diameter tailored specifically for plasmid binding, retention and elution. The polymer was functionalized with 2‐chloro‐N,N‐diethylethylamine hydrochloride (DEAE‐Cl) for anion‐exchange purification of plasmid DNA (pDNA) from clarified lysate obtained from E. coli DH5α‐pUC19 culture in a ribonuclease/protease‐free environment. Characterization of the monolithic resin showed a porous material, with 68% of the pores existing in the matrix having diameters above 300 nm. The final product isolated from a single‐stage 5 min anion‐exchange purification was a pure and homogeneous supercoiled (SC) pDNA with no gDNA, RNA and protein contamination as confirmed by ethidium bromide agarose gel electrophoresis (EtBr‐AGE), enzyme restriction analysis and sodium dodecyl sulfate–polyacrylamide gel electrophoresis. This non‐toxic technique is cGMP compatible and highly scalable for production of pDNA on a commercial level. Copyright © 2007 Society of Chemical Industry
A concise synthesis of single‐enantiomer β‐lactams and β‐amino acids using Rhodococcus globerulus
Authors: Lloyd Michael , Lloyd Richard , Keene Philip , Osborne Andrew 
Published: July 2007

AbstractBACKGROUND: Pharmaceutical companies continue to evaluate β‐amino acids and β‐lactams in a range of drug candidates. The development of a highly efficient and selective bioresolution of cyclic β‐lactam substrates could yield enantiopure lactams and β‐amino acids with medicinal potential. The aim of this work was to discover and develop a biocatalyst capable of selectively hydrolysing β‐lactam substrates.RESULTS: Screening of our in‐house culture collection led to the discovery of a microorganism, Rhodococcus globerulus (NCIMB 41042) with β‐lactamase activity. Whole‐cell bioresolutions of the β‐lactams 1–4 were successfully carried out and in all cases enantiomeric excesses of the residual lactam and amino acid product were found to be greater than 98%. For one example, the bioresolution was optimised to operate at 60 g L−1 substrate concentration with a 20% wt/wt cell paste loading.CONCLUSION: A microorganism, Rhodococcus globerulus (NCIMB 41042), capable of selectively hydrolysing a range of cyclic β‐lactams, has been discovered. A scalable whole‐cell bioresolution process has been developed, leading to the synthesis of multigram quantities of enantiomerically pure β‐lactams and β‐amino acids. Copyright © 2007 Society of Chemical Industry
Bioethanol production from bio‐ organosolv pulps of Pinus radiata and Acacia dealbata
Authors: Muñoz Claudio , Mendonça Regis , Baeza Jaime , Berlin Alex , Saddler John , Freer Juanita 
Published: July 2007

AbstractWood chips from Pinus radiata and Acacia dealbata were pretreated with the white‐rot fungi Ceriporiopsis subvermispora and Ganoderma australe, respectively, for 30 days at 27 °C and 55% relative humidity, followed by an organosolv delignification with 60% ethanol solution at 200 °C for 1 h to produce pulps with high cellulose and low lignin content. Biotreatment for 30 days was chosen based on low weight and cellulose losses (lower than 4%) and lignin degradation higher than 9%. After organosolv delignification, pulp yield for P. radiata and A. dealbata pulps was 45–49% and 31–51%, respectively. P. radiata bio‐pulps showed higher glucan (93%) and lower lignin content (6%) than control pulps (82% glucan and 13% lignin). A. dealbata bio‐pulps also showed higher glucan (95%) and lower lignin content (2%) than control pulps (92% glucan and 4% lignin). Pulp suspensions at 2% consistency were submitted either to separate enzymatic hydrolysis and fermentation (SHF) or simultaneous enzymatic saccharification and fermentation (SSF) for bioethanol production. The yeast Saccharomyces cerevisiae was used for fermentation. Glucan‐to‐glucose conversion in the enzymatic hydrolysis of control and bio‐pulps of P. radiata was 55% and 100%, respectively, and it was 100% for all pulp samples case of A. dealbata. The highest ethanol yield (calculated as percentage of theoretical yield) during SHF of P. radiata control and bio‐pulps was 38% and 55%, respectively, and for A. dealbata control and bio‐pulps 62% and 69%, respectively. The SSF of P. radiata control and bio‐pulps yielded 10% and 65% of ethanol, respectively, and 77% and 82% for A. dealbata control and bio‐pulps, respectively. In wood basis, the maximum conversion obtained (g ethanol per kg wood) in SHF was 37% and 51% (for P. radiata and A. dealbata pulps, respectively) and 44% and 65% in SSF (for P. radiata and A. dealbata pulps, respectively) regarding the theoretical yield. The low wood‐to‐ethanol conversion was associated with low pulp yield (A. dealbata pulps), high residual lignin amount (P. radiata pulps) and the low pulp consistency (2%) used for SHF and SSF. Copyright © 2007 Society of Chemical Industry
Protein identification via ion‐trap collision‐induced dissociation and examination of low‐mass product ions
Authors: Bowers Jeremiah J. , Liu Jian , Gunawardena Harsha P. , McLuckey Scott A. 
Published: July 2007

AbstractA whole‐protein tandem mass spectrometry approach for protein identification based on precursor ion charge state concentration via ion/ion reactions, ion‐trap collisional activation, ion/ion proton‐transfer reactions involving the product ions, and mass analysis over a narrow m/z range (up to m/z 2000) is described and evaluated. The experiments were carried out with a commercially available electrospray ion‐trap instrument that has been modified to allow for ion/ion reactions. Reaction conditions and the approach to searching protein databases were developed with the assumption that the resolving power of the mass analyzer is insufficient to distinguish charge states on the basis of the isotope spacings. Ions derived from several charge states of cytochrome c, myoglobin, ribonuclease A, and ubiquitin were used to evaluate the approach for protein identification and to develop a two‐step procedure to database searching to optimize specificity. The approach developed with the model proteins was then applied to whole cell lysate fractions of Saccharomyces cerevisiae. The results are illustrated with examples of assignments made for three a priori unknown proteins, each selected randomly from a lysate fraction. Two of the three proteins were assigned to species present in the database, whereas one did not match well any database entry. The combination of the mass measurement and the product ion masses suggested the possibility for the oxidation of two methionine residues of a protein in the database. The examples show that this limited whole‐protein characterization approach can provide insights that might otherwise be lacking with approaches based on complete enzymatic digestion. Copyright © 2007 John Wiley & Sons, Ltd.
The role of electrolyte concentration on crevice corrosion of pure nickel
Authors: Abdulsalam M.I. 
Published: July 2007

AbstractIn this work an artificial crevice electrode was used in conjunction with a fine microprobe assembly to measure the potential inside the crevice. Using this setup crevice corrosion of commercially pure nickel was investigated in sulfuric acid with concentrations: 0.5, 1 and 2N. The outer surface of the Ni was held at a passive potential of 530 mV(SCE) while the experiment was running. The results showed a steep potential decay observed in all concentrations. For 0.5, 1 and 2N H2SO4, the total potential drop inside the crevice was: 681, 619 and 593 mV, respectively. This indicates the higher the acid concentration is the lower the potential drop will be. On the other hand, the measured current was highest (4.09 mA) for 2N and lowest (1 mA) for 0.5N. On the crevice wall a boundary was found to exist between the passive and the active regions. These findings point toward the IR voltage drop mechanism operating for this system.
Effect of turbulent flow on the anodic and cathodic kinetics of API X52 steel corrosion in H2S containing solutions. A rotating cylinder electrode study
Authors: Galvan‐Martinez R. , Mendoza‐Flores J. , Duran‐Romero R. , Genesca J. 
Published: July 2007

AbstractThis work presents the electrochemical kinetics results measured during the corrosion of API X52 pipeline steel immersed in aqueous environments, containing dissolved hydrogen sulfide (H2S) under turbulent flow conditions. In order to control the turbulent flow conditions, a rotating cylinder electrode (RCE) was used. Five different rotation rates were studied: 0 (or static conditions), 1000, 3000, 5000 and 7000 rpm. It was found that the turbulent flow increases the corrosion rate and the corrosion mechanism for X52 steel exhibits a significant dependence on mass transfer on the cathodic kinetics.
Barrier and self‐healing abilities of corrosion protective polymer coatings and metal powders for aluminum alloys
Authors: Yabuki A. , Yamagami H. , Noishiki K. 
Published: July 2007

AbstractSeveral types of coatings, designed to improve the resistance of aluminum alloys to corrosion in seawater, were examined. A coating with a thickness of approximately 30 μm was applied to the surface of aluminum alloy 3003, and after creating an artificial defect by means of a knife‐edge, a corrosion test was carried out in 3% NaCl solution at a temperature of 70°C and pH 1.5. The test results showed that a fluorine resin and sol‐gel coatings both had excellent barrier abilities. The fluorine resin coating had self‐healing abilities, and this was improved by the addition of a metal powder.
The use of experimental design method for the investigation of pitting potential of aluminum
Authors: Tosun A. , Ergun M. , Balbaşi M. , Tamirci M. 
Published: July 2007

AbstractThe dependence of the pitting potential (Ep) of aluminum on chloride concentration, pH and the temperature of the solution was studied by the potentiodynamic method according to a statistical experimental design. The parameters of the statistical Ep model offered on the basis of Box‐Wilson experimental design method were evaluated with the use of the experimental data. Comparison of the predicted values from the model with the observed values showed that the model is a good fit. From the model equation the most noble Ep value of − 420 mV was obtained when Cl− ion concentration, temperature and pH of the solution were 57 ppm, 22°C, and 8.3 respectively. Box‐Wilson experimental design technique was proved to be applicable in modelling Ep of aluminum.
Schweißzusatzwerkstoffe können/müssen nicht immer die Anforderungen der Grundwerkstoffe erfüllen
Authors: Heuser H. , Jochum C. 
Published: July 2007

AbstractDie Entwicklung von neuen Stählen ist jeweils eine Herausforderung für die Hersteller von Schweißzusatzwerkstoffen. Je höher die Anforderungsprofile der Grundwerkstoffe für z. B. Streckgrenze, Festigkeit, Zähigkeit oder Korrosionsbeständigkeit sind, je schwieriger sind diese Vorgaben in Schweißverbindungen zu erzielen. In vielen Fällen sind artfremde Schweißzusätze notwendig bzw. können die geforderten Eigenschaften nur mit bestimmten Schweißprozessen realisiert werden. In diesem Beitrag werden Beispiele zu Stählen mit hohen Festigkeitsanforderungen behandelt und die Grenzen bei der schweißtechnischen Verarbeitung aufgezeigt: Automobilindustrie (Hochfeste Stähle (LIP) und Mangan‐Austenite), Mobilkrane (Ultrahochfeste Stähle mit Streckgrenzen ≥ 960 MPa), Erdbewegungsmaschinen (verschleißbeständige Stähle) und Offshore (Supermartensitische Stähle). Spezifische Probleme werden diskutiert und Lösungsmöglichkeiten aufgezeigt. Die Beispiele machen deutlich, dass ein erfolgreicher Einsatz neuer Stähle in erster Linie abhängt von realisierbaren Konzepten zur schweißtechnischen Verarbeitung.
Elektronenstrahlschweißen an Atmosphäre – von der Entwicklung bis zum industriellen Einsatz
Authors: Masny H. 
Published: July 2007

AbstractBedingt durch die zunehmende Standardisierung in vielen Bereichen der industriellen Fertigung, die Ressourcenschonung und dadurch der Zwang zum Leichtbau sowie die rasche Entwicklung auf dem Werkstoffsektor, werden an die Fügetechniken immer komplexere Aufgaben herangetragen. Dies betrifft sowohl das Fügeverfahren selbst, das den zu verbindenden Grundwerkstoffen in metallurgischer Hinsicht gerecht werden muss, als auch seine Wirtschaftlichkeit. In diesem Zusammenhang kommt dem Elektronenstrahlschweißen an Atmosphäre ‐ NV‐EBW ‐ als Verbindungstechnik eine immer größere Bedeutung und steigendes Interesse seitens der Industrie zu. Das NV‐EBW verbindet die vielen bekannten Vorteile des Elektronenstrahlschweißens im Vakuum mit der Möglichkeit unter normalem Umgebungsdruck zu arbeiten. Mit einem Anlagenwirkungsgrad von über 50 % und den sehr hohen erreichbaren Schweißgeschwindigkeiten von bis zu 60 m/min bei Aluminiumwerkstoffen ist der Elektronenstrahl an Atmosphäre ein effizientes und wirtschaftliches Werkzeug in der Schweißtechnik.Im ISF wird seit Jahren unter der Leitung von Professor U. Dilthey an der NV‐EBW Technologie in engem Kontakt mit industriellen Partnern geforscht. Dabei wurden wesentliche Beiträge zur Entwicklung eines rotationssymmetrischen Druckstufensys­tems sowie zur Erprobung und Optimierungen des Verfahrens hinsichtlich der jeweiligen Schweißaufgaben geleistet.
Telomere shortening in diaphragm and tibialis anterior muscles of aged mdx mice
Authors: Lund Troy C. , Grange Robert W. , Lowe Dawn A. 
Published: July 2007

AbstractThe progression of Duchenne muscular dystrophy (DMD) is, in part, due to satellite cell senescence driven by high replicative pressure as these muscle stem cells repeatedly divide and fuse to damaged muscle fibers. We hypothesize that telomere shortening in satellite cells underlies their senescence. To test this hypothesis, we evaluated the diaphragm and a leg muscle from dystrophic mice of various ages for telomere dynamics. We found 30% telomere shortening in tibialis anterior muscles from 600‐day‐old mdx mice relative to age‐matched wildtype mice. We also found a more severe shortening of telomere length in diaphragm muscles of old mdx mice. In those muscles, telomeres were shortened by ∼15% and 40% in 100‐ and 600‐day‐old mdx mice, respectively. These findings indicate that satellite cells undergo telomere erosion, which may contribute to the inability of these cells to perpetually repair DMD muscle. Muscle Nerve, 2007