bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transitions from home to marriage of young Americans
Authors: Aassve Arnstein , Burgess Simon , Chesher Andrew , Propper Carol 
Published: January 2005

AbstractThe paper examines the impact of income on the transitions between home, living independently and first marriage of young Americans. A matching model is outlined, similar to that used in theories of job search, to explain the probability of marriage and living alone. A multiple‐state, multiple‐transition model which allows for correlated heterogeneity on the first and subsequent transitions is estimated. The results show that income has a strong and significant effect. The impact of unobserved heterogeneity is examined in detail. The impact of the young person's earnings on the transitions is explored through simulation. Copyright © 2002 John Wiley & Sons, Ltd.
Manipulation of nanoneedle and nanosphere apatite/poly(acrylic acid) nanocomposites
Authors: Liou Sz‐Chian , Chen San‐Yuan , Liu Dean‐Mo 
Published: January 2005

AbstractColloidal apatitic nanosphere of 2–5 nm in diameter was synthesized in the presence of poly(acrylic acid), PAA. PAA, which has long been recognized as an inhibitor in the synthesis of hydroxyapatite, is used as a structure‐directing agent for the synthesis of calcium‐deficient apatite (CDHA) in this study. Experimental observation suggests a critical amount of the low‐molecular‐weight PAA, above which morphological evolution of CDHA nanoparticles from needle to sphere was observed. This reveals that the PAA acts as an inhibitor for the growth of CDHA crystals. Further incorporation of PAA of high molecular weight formed a highly optically transparent nanocomposite, even with the nanospherical apatite loading up to 35 wt %, suggesting no agglomeration. This was further justified through transmission electron microscopy (TEM), where the CDHA nanospheres were uniformly distributed in the PAA‐CDHA nanocomposites. No interfacial crevices were visually observed, indicating a highly compatible interface between the inorganic CDHA and organic PAA phase. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 73B: 117–122, 2005
Deep‐penetrating conical cracks in brittle layers from hydraulic cyclic contact
Authors: Zhang Yu , Song Jun‐Kwang , Lawn Brian R. 
Published: January 2005

AbstractA study is made of fracture from cyclic loading of WC spheres on the top surfaces of thick (1 mm) brittle layers on polymeric substrates, as representative of repetitive occlusal contact on dental crown structures. The advantage of glass layers is that internal cracks can be followed in situ during the entire cyclic loading process. The glass surfaces are first given a surface‐abrasion treatment to control the flaw state, such that the strengths match those of dental porcelains. Cyclic contact tests are carried out at prescribed maximum loads and frequencies, in water. In addition to conventional cone cracks that form outside the contact circle, additional, inner cone cracks form within the contact in the water environment. These inner cones are observed only in cyclic loading in water and are accelerated at higher frequencies, indicating a strong mechanical driving force. They tend to initiate after the outer cones, but subsequently catch up and penetrate much more rapidly and deeply, ultimately intersecting the underlying coating/substrate interface. Comparative tests on glass/polymer bilayers versus monolithic glass, in cyclic versus static loading, in water versus air environment, on abraded versus etched surfaces, and with glass instead of WC indenters, confirm the existence of a dominant mechanical element in the inner‐cone crack evolution. It is suggested that the source of the mechanical driving force is hydraulic pressure from intrusion and entrapment of liquid in surface fissures at the closing contact interface. This new type of cone cracking may limit dental crown veneer lifetimes under occlusal fatigue conditions, especially in thicker layers, where competing modes—such as undersurface radial cracks—are suppressed. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biometer 73B: 186–193, 2005
Evaluation of the micromechanical elastic properties of potential bone‐grafting materials
Authors: Nomura Tsutomu , Katz J. Lawrence , Powers Michael P. , Saito Chikara 
Published: January 2005

AbstractThe micromechanical elastic properties of potential bone‐graft materials were compared with that of the human mandible. Six different potential bone‐replacement materials were used: Bio‐Oss (Osteohealth), OsteoGraf/N‐700 (Ceramed), Pepgen P15 (Ceramed), Interpore200 (Interpore Cross International), Allogro (Ceramed), and Dynagraft (GenSci Dental). As a control, mandibular cortical bone was obtained from a 17‐year‐old woman. Micromechanical elastic property analysis was obtained with the use of a UH3 scanning acoustic microscope (Olympus Co., Tokyo, Japan) (SAM) at 400 MHz in the burst mode. Each sample was measured at three areas. The data were analyzed statistically by SPSS (SPSS, Inc.) with the use of the Student t test. In human bone, the reflection coefficients r of the x dimension (r = 0.75 ± 0.01) was statistically higher than those of the y (0.72 ± 0.05) and the z (0.72 ± 0.01) directions. The order of stiffness magnitude was found to be Pepgen (r = 0.73 ± 0.05) ≥ OsteoGraf (0.72 ± 0.03) > Bio‐Oss (0.71 ± 0.02) > Interpore (0.69 ± 0.10) > Dynagraft (0.43 ± 0.05) > Allogro (0.36 ± 0.04). For these samples, Interpore alone showed a large deviation in properties in the same specimen. With regard to the elastic properties solely, bone‐grafting materials made from bovine or processed marine coral appear to be reasonable choices as graft materials. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 73B: 29–34, 2005
Regulation of intracellular glycine as an organic osmolyte in early preimplantation mouse embryos
Authors: Steeves Candace L. , Baltz Jay M. 
Published: January 2005

AbstractGLYT1, a glycine transporter belonging to the neurotransmitter transporter family, has recently been identified as a novel cell volume‐regulatory mechanism in the earliest stages of the mouse preimplantation embryo. It apparently acts by regulating the steady‐state intracellular concentration of glycine, which functions as an organic osmolyte in embryos, to balance external osmolarity and thus maintain cell volume. GLYT1 in embryos was the first mammalian organic osmolyte transporter identified that appears to function in cell volume control under conditions of normal osmolarity, rather than being a response to the stress of chronic hypertonicity. Its maximal rate of transport was shown to be regulated by osmolarity. However, it was not known whether this osmotic regulation of the rate of glycine transport is sufficient to account for the observed control of steady‐state intracellular glycine levels as a function of osmolarity in embryos. Here, we show that the intracellular accumulation of glycine in embryos is a direct function of the rate of glycine uptake via GLYT1. In addition, we have shown that the rate of efflux, likely via the volume‐regulated anion and organic osmolyte channel in embryos, is also under osmotic regulation and contributes substantially to the control of steady‐state glycine concentrations. Together, control of both the rate of uptake and rate of efflux of glycine underlies the mechanism of osmotic regulation of the steady‐state concentration of glycine and hence cell volume in early embryos. © 2005 Wiley‐Liss, Inc.
Collagenase expression and activity is modulated by the interaction of collagen types, hypoxia, and nutrition in human lung cells
Authors: Leufgen H. , Bihl M.P. , Rüdiger J.J. , Gambazzi J. , Perruchoud A.P. , Tamm M. , Roth M. 
Published: January 2005

AbstractHypoxia not only controls organogenesis, embryogenesis, and wound repair, but also triggers tumor progression and metastasis. Matrix metalloproteinases (MMP), especially gelatinases (MMP‐2, MMP‐9) regulate the composition and stability of the extracellular matrix (ECM), which affects cell proliferation, migration, and differentiation. This study investigated the effect of hypoxia alone and in combination with ECM compounds and nutrition on MMP‐2 and MMP‐9 expression, activity, and synthesis in human lung fibroblasts and pulmonary vascular smooth muscle cells (VSMC). We also determined the expression of the tissue inhibitors of MMP (TIMP‐1, ‐2). Cells were grown on plastic, collagen‐I, collagen‐IV, or gelatin and in either starving medium (0.1% serum) or growth medium (5% serum), and were subjected to normoxia or hypoxia (1% O2). Collagenases expression was determined by zymography. TIMP‐1, ‐2 expression was assessed by Western blotting and RT‐PCR. Depending on serum concentration human lung cells expressed pro‐MMP‐2 on all substrates. Hypoxia increased pro‐MMP‐2 expression, on collagen type I or type IV further via Erk1/2 and p38 MAP kinase signaling. MMP‐9 was only expressed when cells were grown on collagen type IV and increased with serum concentration, and by hypoxia. TIMP‐1 expression was only expressed when cells were grown on collagen type I and was significantly increased by hypoxia, while TIMP‐2 expression was unchanged. We demonstrated that the hypoxia, ECM composition, and nutrition, rather than one of these conditions alone, modulate the expression and activity of collagenases and their inhibitors in primary human lung fibroblasts. © 2005 Wiley‐Liss, Inc.
Thrombospondin‐1 deficient mice exhibit an altered expression pattern of alternatively spliced PECAM‐1 isoforms in retinal vasculature and endothelial cells
Authors: Wang Yongji , Su Xiaojing , Wu Zhifeng , Sheibani Nader 
Published: January 2005

AbstractWe have previously shown that thrombosponsin‐1 (TSP1) and PECAM‐1 are components of a regulatory switch whose reciprocal regulation in the endothelial cells (EC) promotes an angiogenic or a differentiated, quiescent phenotype. The physiological role TSP1 plays in modulation of PECAM‐1 expression and function during vascular development and angiogenesis remains largely unknown. Here we demonstrate that PECAM‐1 undergoes alternative splicing in its cytoplasmic domain generating eight isoforms in the retinal vasculature of wild type and TSP1−/− mice. All PECAM‐1 isoforms examined contained exon 13. The frequency of PECAM‐1 isoform(s) containing exon 14 was significantly higher during early stages of retinal vascularization, which decreased during later stages of retinal vascularization in wild type mice. In contrast, the frequency of exon 14 containing PECAM‐1 isoform(s) did not significantly change during retinal vascularization in TSP1−/− mice. They consistently expressed higher number of isoforms with exon 14 during later stages of retinal vascularization. The higher level of PECAM‐1 isoforms with exon 14 was also observed in cultured TSP1−/− retinal EC compared to wild type retinal EC. This was consistent with increased amounts of Src and SHP‐2 associated with PECAM‐1, and enhanced migration and proliferation in TSP1−/− retinal EC. These data suggest PECAM‐1 signaling in the endothelium is modulated by its alternative splicing during retinal vascular development and angiogenesis, which may be impacted by TSP1 expression. © 2005 Wiley‐Liss, Inc.
Cdc25A and ERK interaction: EGFR‐independent ERK activation by a protein phosphatase Cdc25A inhibitor, compound 5
Authors: Wang Ziqiu , Zhang Baochun , Wang Meifang , Carr Brian I. 
Published: January 2005

AbstractExtracellular signal‐regulated kinase (ERK) plays a central role in regulating cell growth, differentiation, and apoptosis. We previously found that 2‐(2‐mercaptoethanol)‐3‐methyl‐1,4‐napthoquinone or Compound 5 (Cpd 5), is a Cdc25A protein phosphatase inhibitor and causes prolonged, strong ERK phosphorylation which is triggered by epidermal growth factor receptor (EGFR) activation. We now report that Cpd 5 can directly cause ERK phosphorylation by inhibiting Cdc25A activity independently of the EGFR pathway. We found that Cdc25A physically interacted with and de‐phosphorylated phospho‐ERK both in vitro and in cell culture. Inhibition of Cdc25A activity by Cpd 5 resulted in ERK hyper‐phosphorylation. Transfection of Hep3B human hepatoma cells with inactive Cdc25A mutant enhanced Cpd 5 action on ERK phosphorylation, whereas over‐expression of Cdc25A attenuated this Cpd 5 action. Furthermore, endogenous Cdc25A knock‐down by Cdc25A siRNA resulted in a constitutive‐like ERK phosphorylation and Cpd 5 treatment further enhanced it. In EGFR‐devoid NR6 fibroblasts and MEK (ERK kinase) mutated MCF7 cells, Cpd 5 treatment also resulted in ERK phosphorylation, providing support for the idea that Cpd 5 can directly act on ERK phosphorylation by inhibiting Cdc25A activity. These data suggest that phospho‐ERK is likely another Cdc25A substrate, and Cpd 5‐caused ERK phosphorylation is probably regulated by both EGFR‐dependent and EGFR‐independent pathways. © 2005 Wiley‐Liss, Inc.
Receptor‐operated Ca2+ entry mediated by TRPC3/TRPC6 proteins in rat prostate smooth muscle (PS1) cell line
Authors: Thebault S. , Zholos A. , Enfissi A. , Slomianny C. , Dewailly E. , Roudbaraki M. , Parys J. , Prevarskaya Natalia 
Published: January 2005

AbstractProstate smooth muscle cells predominantly express α1‐adrenoceptors (α1‐AR). α1‐AR antagonists induce prostate smooth muscle relaxation and therefore they are useful therapeutic compounds for the treatment of benign prostatic hyperplasia symptoms. However, the Ca2+ entry pathways associated with the activation of α1‐AR in the prostate have yet to be elucidated. In many cell types, mammalian homologues of transient receptor potential (TRP) genes, first identified in Drosophila, encode TRPC (canonical TRP) proteins. They function as receptor‐operated channels (ROCs) which are involved in various physiological processes such as contraction, proliferation, apoptosis, and differentiation. To date, the expression and function of TRPC channels have not been studied in prostate smooth muscle. In fura‐2 loaded PS1 (a prostate smooth muscle cell line) which express endogenous α1A‐ARs, α‐agonists epinephrine (EPI), and phenylephrine (PHE) induced Ca2+ influx which depended on the extracellular Ca2+ and PLC activation but was independent of PKC activation. Thus, we have tested two membrane‐permeable analogues of diacylglycerol (DAG), oleoyl‐acyl‐sn‐glycerol (OAG) and 1,2‐dioctanoyl‐sn‐glycerol (DOG). They initiated Ca2+ influx whose properties were similar to those induced by the α‐agonists. Sensitivity to 2‐aminoethyl diphenylborate (2‐APB), SKF‐96365 and flufenamate implies that Ca2+‐permeable channels mediated both α‐agonist‐ and OAG‐evoked Ca2+ influx. Following the sarcoplasmic reticulum (SR) Ca2+ store depletion by thapsigargin (Tg), a SERCA inhibitor, OAG and PHE were both still able to activate Ca2+ influx. However, OAG failed to enhance Ca2+ influx when added in the presence of an α‐agonist. RT‐PCR and Western blotting performed on PS1 cells revealed the presence of mRNAs and the corresponding TRPC3 and TRPC6 proteins. Experiments using an antisense strategy showed that both α‐agonist‐ and OAG‐induced Ca2+ influx required TRPC3 and TRPC6, whereas the Tg‐activated (“capacitative”) Ca2+ entry involved only TRPC3 encoded protein. It may be thus concluded that PS1 cells express TRPC3 and TRPC6 proteins which function as receptor‐ and store‐operated Ca2+ entry pathways. © 2005 Wiley‐Liss, Inc.
Kinetics of hydrogenation of 4‐chloro‐2‐nitrophenol catalyzed by Pt/carbon catalyst
Authors: Halligudi S B , Khaire Surekha S 
Published: January 2005

AbstractHydrogenation of 4‐chloro‐2‐nitrophenol (CNP) was carried out at moderate hydrogen pressures, 7–28 atm, and temperatures in the range 298–313 K using Pt/carbon and Pd/γ‐Al2O3 as catalysts in a stirred pressure reactor. Hydrogenation of CNP under the above conditions gave 4‐chloro‐2‐aminophenol (CAP). Dechlorination to form 2‐aminophenol and 2‐nitrophenol is observed when hydrogenation of CNP is carried out above 338 K, particularly with Pd/γ‐Al2O3 catalyst. Among the catalysts tested, 1%Pt/C was found to be an effective catalyst for the hydrogenation of CNP to form CAP, exclusively. To confirm the absence of gas–liquid mass transfer effects on the reaction, the effect of stirring speed (200–1000 rpm) and catalyst loading (0.02–0.16 g) on the initial reaction rate at maximum temperature 310 K and substrate concentration (0.25 mole) were thoroughly studied. The kinetics of hydrogenation of CNP carried out using 1%Pt/C indicated that the initial rates of hydrogenation had first order dependence with respect to substrate, catalyst and hydrogen pressure in the range of concentrations varied. From the Arrhenius plot of ln rate vs 1000/T, an apparent activation energy of 22 kJ mol−1 was estimated.© 2001 Society of Chemical Industry
Minimum fluidization velocity and gas holdup in gas–liquid–solid fluidized bed reactors
Authors: Ramesh K , Murugesan T 
Published: January 2005

AbstractExperiments were performed to study the hydrodynamics of a cocurrent three‐phase fluidized bed with liquid as continuous phase. Based on the 209 experimental data (with four liquid systems and five different particles) along with 115 literature data from six different sources on minimum fluidization velocity, a unique correlation for the estimation of minimum fluidization velocity in two‐phase (ug = 0) as well as in three‐phase systems is developed. A data bank consisting of 1420 experimental measurements for the fractional gas phase holdup data with a wide range of variables is used for developing empirical correlations. Separate correlations are developed for two flow regimes observed in this present work. The proposed correlations are more accurate and simpler to use.© 2002 Society of Chemical Industry
Biotransformation of benzaldehyde to L‐phenylacetylcarbinol (L‐PAC) by Torulaspora delbrueckii and conversion to ephedrine by microwave radiation
Authors: Shukla Vilas B , Madyar Virendra R , Khadilkar Bhushan M , Kulkarni Pushpa R 
Published: January 2005

AbstractIn a 5 dm3 stirred tank reactor, bioconversion of 30 g benzaldehyde by cells of Torulaspora delbrueckii yielded 22.9 g of pure L‐phenylacetylcarbinol (L‐PAC). Facile functional group transformation of 4.5 g of L‐PAC to 2‐(methylimino)‐1‐phenyl‐1‐propanol by exposure to microwave irradiation for 9 min resulted in 2.48 g of product. Conversion of 4.8 g of 2‐(methylimino)‐1‐phenyl‐1‐propanol to 3.11 g of ephedrine was achieved by exposure to microwaves in a reaction time of 10 min. The identity of all the products was confirmed by 1H NMR and FT‐IR analysis.© 2002 Society of Chemical Industry
Adsorption of colour from a bleach plant effluent using biomass and cell wall fractions from Rhizomucor pusillus
Authors: Driessel Brian van , Christov Lew 
Published: January 2005

AbstractRelatively high decolourisation of bleach plant effluent (41%–48%) could be attained in short treatment times using biomass of Rhizomucor pusillus, a mucoralean fungus. Cell wall fractions (alkali‐resistant, residual and chitosan fractions) extracted from the R pusillus biomass appeared to be mainly responsible for the adsorption of chromophores from bleach plant effluent by this fungus. The alkali‐resistant fraction removed 34% of the colour from bleach plant effluent. Although the residual and chitosan fractions represented only about 12% of the total dry biomass, they removed more colour from bleach plant effluent (41%) than did the intact biomass (39%). The chitosan and residual cell wall fractions, mainly composed of chitin and/or chitosan, seem to be involved in the mechanism of colour removal from bleach plant effluent by R pusillus.© 2002 Society of Chemical Industry
Production of androstenedione using mutants of Mycobacterium sp
Authors: Egorova Olga V , Gulevskaya Seraphima A , Puntus Irina F , Filonov Andrey E , Donova Marina V 
Published: January 2005

AbstractMycobacterium sp VKM Ac‐1815D strain was able to cleave sterol side chain giving androstenedione (AD) as a major product with a molar yield of 63–68%. Clones having altered resistance to antibacterial agents were selected. After treatment with ethyl methane sulfonate or mitomycin C, mutants were obtained that retained the ability to produce AD from sitosterol with molar yields of 70–75%. A mutant strain able to effectively reduce 3,17‐diketosteroids at C‐17 was selected. The 17β‐hydroxy steroid dehydrogenase activity of its crude extract was twice as high as that found for the parent organism. The approach offers the possibility of obtaining improved and labelled biocatalysts for AD or testosterone production from sterols.© 2002 Society of Chemical Industry
Treatment of wastewater containing dyes used in the Syrian textile industry
Authors: El‐Kadri Saleh , Dabbit Ousama , Kakhia Hassan 
Published: January 2005

AbstractThree types of wastewater, from commercial dyeings containing reactive, disperse and direct dyes were treated using an organic coagulant at pH 5.5 as a first step, with stirring for 5 min. The second step was oxidation by Fenton's reagent (hydrogen peroxide and iron(II) sulfate) at pH 2.5–3 for 30 min. The pH of the solution was then raised to 7.5–8 where coagulation by iron hydroxide took place over 20 min. Finally, sand filtration was performed. The percentage of color removal from treated wastewater was more than 99.00% and the percentage decrease in COD was more than 96.00%.© 2002 Society of Chemical Industry
Advanced oxidation with ozone of 1,3,6‐naphthalenetrisulfonic acid in aqueous solution
Authors: Sánchez‐Polo M , Rivera‐Utrilla J , Zaror C A 
Published: January 2005

AbstractThe kinetics of oxidation with ozone of 1,3,6‐naphthalenetrisulfonic acid was analysed by studying the influence of different experimental parameters such as the concentration oftert‐butyl alcohol (2‐methyl‐2‐propanol), initial concentration of the acid, pH, and temperature. The rate constant of the direct reaction at 25 °C was calculated (kD = 6.72 M−1s−1). The constant of the free radical reaction was determined with the competitive kinetics method, using sodium 4‐chlorobenzoate as reference compound, obtaining a value ofkOH = 3.7 × 109 M−1s−1. It was demonstrated that even at very acid pH values, 80% of the 1,3,6‐naphthalenetrisulfonic acid was degraded by free radical reactions, so that the ozonation of this acid may be considered an advanced oxidation process.© 2002 Society of Chemical Industry
Study of operating variables in the transformation of aqueous ethanol into hydrocarbons on an HZSM‐5 zeolite
Authors: Aguayo Andres T , Gayubo Ana G , Tarrío Ana M , Atutxa Alaitz , Bilbao Javier 
Published: January 2005

AbstractWith the aim of determining the possibilities of directly upgrading the liquid obtained from carbohydrate fermentation, the effect of operating conditions (temperature, space time, water content in the feed) has been studied in the catalytic transformation of aqueous ethanol into hydrocarbons on an HZSM‐5 zeolite in an isothermal fixed bed reactor. Special attention has been paid to the effect of water content on the yield, product distribution and catalyst deactivation. Although deactivation by coke decreases as the water content is increased, this content must be limited at 450 °C and higher temperatures in order to avoid irreversible deactivation of the catalyst by dealumination.© 2002 Society of Chemical Industry