bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maternal periconceptional exposure to cigarette smoking and alcohol and esophageal atresia ± tracheo‐esophageal fistula
Authors: Wong‐Gibbons Donna L. , Romitti Paul A. , Sun Lixian , Moore Cynthia A. , Reefhuis Jennita , Bell Erin M. , Olshan Andrew F. 
Published: November 2008

AbstractBACKGROUND: Esophageal atresia (EA) is a moderately frequent birth defect that often occurs with tracheo‐esophageal fistula (TEF). Etiologic studies for EA±TEF have produced inconsistent results. METHODS: This study used data from the National Birth Defects Prevention Study (NBDPS) to examine the association between maternal periconceptional exposure to cigarette smoking and alcohol and EA±TEF. Cases of EA±TEF and unaffected controls with an estimated date of delivery from October 1997 through December 2003 were identified, and telephone interview reports for smoking and alcohol exposure were obtained from birth mothers of 334 cases and 4,967 controls. Odds ratios (OR)s and 95% confidence intervals (CI)s, adjusted for several covariates, were calculated to assess associations. RESULTS: ORs were near unity for all EA±TEF cases combined and any periconceptional exposure to cigarette smoking (OR = 1.1; CI = 0.8,1.6) or alcohol (OR = 1.2; CI = 0.8,1.8). For cigarette smoking, some elevated ORs were found but varied by type of smoking exposure. No consistent patterns were identified for number of cigarettes smoked per day. For alcohol, ORs were weak to moderately elevated with increasing number of drinks consumed and for binge drinkers compared to non‐binge drinkers. ORs were further elevated among mothers who reported active+passive exposure to cigarette smoking and alcohol (OR = 2.5; CI = 1.1,5.6). For both exposures, ORs were higher for cases with additional major defects compared to isolated cases. CONCLUSIONS: These results, based on one of the largest published samples of EA±TEF cases, suggest a role for these exposures in the etiology of EA±TEF, although further study is needed to replicate the observed associations. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.
Performance and population analysis of a non‐sterile trickle bed reactor inoculated with Caldicellulosiruptor saccharolyticus, a thermophilic hydrogen producer
Authors: van Groenestijn J.W. , Geelhoed J.S. , Goorissen H.P. , Meesters K.P.M. , Stams A.J.M. , Claassen P.A.M. 
Published: November 2008

AbstractNon‐axenic operation of a 400 L trickle bed reactor inoculated with the thermophile Caldicellulosiruptor saccharolyticus, yielded 2.8 mol H2/mol hexose converted. The reactor was fed with a complex medium with sucrose as the main substrate, continuously flushed with nitrogen gas, and operated at 73°C. The volumetric productivity was 22 mmol H2/(L filterbed h). Acetic acid and lactic acid were the main by‐products in the liquid phase. Production of lactic acid occurred when hydrogen partial pressure was elevated above 2% and during suboptimal fermentation conditions that also resulted in the presence of mono‐ and disaccharides in the effluent. Methane production was negligible. The microbial community was analyzed at two different time points during operation. Initially, other species related to members of the genera Thermoanaerobacterium and Caldicellulosiruptor were present in the reactor. However, these were out‐competed by C. saccharolyticus during a period when sucrose was completely used and no saccharides were discharged with the effluent. In general, the use of pure cultures in non‐sterile industrial applications is known to be less useful because of contamination. However, our results show that the applied fermentation conditions resulted in a culture of a single dominant organism with excellent hydrogen production characteristics. Biotechnol. Bioeng. 2009;102: 1361–1367. © 2008 Wiley Periodicals, Inc.
Elucidation of metabolism in hybridoma cells grown in fed‐batch culture by genome‐scale modeling
Authors: Selvarasu Suresh , Wong Victor V.T. , Karimi Iftekhar A. , Lee Dong‐Yup 
Published: November 2008

AbstractGenome‐scale modeling of mouse hybridoma cells producing monoclonal antibodies (mAb) was performed to elucidate their physiological and metabolic states during fed‐batch cell culture. Initially, feed media nutrients were monitored to identify key components among carbon sources and amino acids with significant impact on the desired outcome, for example, cell growth and antibody production. The monitored profiles indicated rapid assimilation of glucose and glutamine during the exponential growth phase. Significant increase in mAb concentration was also observed when glutamine concentration was controlled at 0.5 mM as a feeding strategy. Based on the reconstructed genome‐scale metabolic network of mouse hybridoma cells and fed‐batch profiles, flux analysis was then implemented to investigate the cellular behavior and changes in internal fluxes during the cell culture. The simulated profile of the cell growth was consistent with experimentally measured specific growth rate. The in silico simulation results indicated (i) predominant utilization of glycolytic pathway for ATP production, (ii) importance of pyruvate node in metabolic shifting, and (iii) characteristic pattern in lactate to glucose ratio during the exponential phase. In future, experimental and in silico analyses can serve as a promising approach to identifying optimal feeding strategies and potential cell engineering targets as well as facilitate media optimization for the enhanced production of mAb or recombinant proteins in mammalian cells. Biotechnol. Bioeng. 2009;102: 1494–1504. © 2008 Wiley Periodicals, Inc.
Automated, scalable culture of human embryonic stem cells in feeder‐free conditions
Authors: Thomas Rob J. , Anderson David , Chandra Amit , Smith Nigel M. , Young Lorraine E. , Williams David , Denning Chris 
Published: November 2008

AbstractLarge‐scale manufacture of human embryonic stem cells (hESCs) is prerequisite to their widespread use in biomedical applications. However, current hESC culture strategies are labor‐intensive and employ highly variable processes, presenting challenges for scaled production and commercial development. Here we demonstrate that passaging of the hESC lines, HUES7, and NOTT1, with trypsin in feeder‐free conditions, is compatible with complete automation on the CompacT SelecT, a commercially available and industrially relevant robotic platform. Pluripotency was successfully retained, as evidenced by consistent proliferation during serial passage, expression of stem cell markers (OCT4, NANOG, TRA1‐81, and SSEA‐4), stable karyotype, and multi‐germlayer differentiation in vitro, including to pharmacologically responsive cardiomyocytes. Automation of hESC culture will expedite cell‐use in clinical, scientific, and industrial applications. Biotechnol. Bioeng. 2009;102: 1636–1644. © 2008 Wiley Periodicals, Inc.
Concentration of mammalian genomic DNA using two‐phase aqueous micellar systems
Authors: Mashayekhi Foad , Meyer Aaron S. , Shiigi Stacey A. , Nguyen Vu , Kamei Daniel T. 
Published: November 2008

AbstractThe concentration of biomarkers, such as DNA, prior to a subsequent detection step may facilitate the early detection of cancer, which could significantly increase chances for survival. In this study, the partitioning behavior of mammalian genomic DNA fragments in a two‐phase aqueous micellar system was investigated using both experiment and theory. The micellar system was generated using the nonionic surfactant Triton X‐114 and phosphate‐buffered saline (PBS). Partition coefficients were measured under a variety of conditions and compared with our theoretical predictions. With this comparison, we demonstrated that the partitioning behavior of DNA fragments in this system is primarily driven by repulsive, steric, excluded‐volume interactions that operate between the micelles and the DNA fragments, but is limited by the entrainment of micelle‐poor, DNA‐rich domains in the macroscopic micelle‐rich phase. Furthermore, the volume ratio, that is, the volume of the top, micelle‐poor phase divided by that of the bottom, micelle‐rich phase, was manipulated to concentrate DNA fragments in the top phase. Specifically, by decreasing the volume ratio from 1 to 1/10, we demonstrated proof‐of‐principle that the concentration of DNA fragments in the top phase could be increased two‐ to nine‐fold in a predictive manner. Biotechnol. Bioeng. 2009;102: 1613–1623. © 2008 Wiley Periodicals, Inc.
Dependence of alignment direction on magnitude of strain in esophageal smooth muscle cells
Authors: Ritchie A.C. , Wijaya S. , Ong W.F. , Zhong S.P. , Chian K.S. 
Published: November 2008

AbstractThe response of cells in vitro to mechanical forces has been the subject of much research using devices to exert controlled mechanical stimulation on cultured cells or isolated tissue. In this study, esophageal smooth muscle cells were seeded on flexible polyurethane membranes to form a confluent cell layer. The cells were then subjected to uniform cyclic stretch of varying magnitudes at a frequency of approximately five cycles per minute in a custom made mechatronic bioreactor, providing similar strains experienced in the in vivo mechanical environment of the esophagus. The results show that the orientation response is dependent on the magnitude of cyclic stretch applied. Smooth muscle cells showed parallel alignment to the force direction at low cyclic strains (2%) compared to the hill‐valley morphology of static controls. At higher strains (5% and 10% magnitude), the cells exhibited a consistent alignment perpendicular to the strain. To our knowledge, this is the first time that the alignment direction's dependence on strain magnitude has been demonstrated. MTS analysis indicated that cell metabolism was reduced when mechanical strain was applied, and proliferation was inhibited by mechanical strain. Protein expression indicates a decrease in smooth muscle α‐actin, indicative of changes in cell phenotype, an increase in vimentin, which is associated with increased cell motility, and an increase in desmin, indicating differentiation in stimulated cells. Biotechnol. Bioeng. 2009;102: 1703–1711. © 2008 Wiley Periodicals, Inc.
Development of an in vitro cell culture model of hepatic steatosis using hepatocyte‐derived reporter cells
Authors: Janorkar Amol V. , King Kevin R. , Megeed Zaki , Yarmush Martin L. 
Published: November 2008

AbstractFatty liver disease is a problem of growing clinical importance due to its association with the increasingly prevalent conditions of obesity and diabetes. While steatosis represents a reversible state of excess intrahepatic lipid, it is also associated with increased susceptibility to oxidative and cytokine stresses and progression to irreversible hepatic injury characterized by steatohepatitis, cirrhosis, and malignancy. Currently, the molecular mechanisms underlying progression of this dynamic disease remain poorly understood, particularly at the level of transcriptional regulation. We recently constructed a library of stable monoclonal green fluorescent protein (GFP) reporter cells that enable transcriptional regulation to be studied dynamically in living cells. Here, we adapt the reporter cells to create a model of steatosis that will allow investigation of transcriptional dynamics associated with the development of steatosis and the response to subsequent “second hit” stresses. The reporter model recapitulates many cellular features of the human disease, including fatty acid uptake, intracellular triglyceride accumulation, increased reactive oxygen species accumulation, decreased mitochondrial membrane potential, increased susceptibility to apoptotic cytokine stresses, and decreased proliferation. Finally, to demonstrate the utility of the reporter cells for studying transcriptional regulation, we compared the transcriptional dynamics of nuclear factor κB (NFκB), heat shock response element (HSE), and glucocorticoid response element (GRE) in response to their classical inducers under lean and fatty conditions and found that intracellular lipid accumulation was associated with dose‐dependent impairment of NFκB and HSE but not GRE activation. Thus, steatotic reporter cells represent an efficient model for studying transcriptional responses and have the potential to provide important insights into the progression of fatty liver disease. Biotechnol. Bioeng. 2009;102: 1466–1474. © 2008 Wiley Periodicals, Inc.
Sugaring‐Out Separation of Acetonitrile from Its Aqueous Solution
Authors: Wang B. , Feng H. , Ezeji T. , Blaschek H. 
Published: November 2008

AbstractThe separation of acetonitrile (ACN) from an ACN‐water azeotrope is of particular interest to industrial chemists and process engineers. In the work reported in this article, sugaring‐out, a new phase separation method is reported and used to obtain high purity ACN from an ACN‐water mixture. With the addition of a mono‐sugar (glucose, xylose, arabinose or fructose) or a disaccharide (sucrose or maltose) into an ACN‐water mixture, a phase separation is observed if the sugar concentration exceeds a threshold. The upper phase is rich in ACN while the lower phase is rich in water. The ACN concentration in the upper phase increases when more sugar is added into the ACN‐water mixture. When the glucose concentration is > 35 g/L, the ACN concentration in the upper phase is > 40 %. In the Sudan I extraction test with a glucose‐triggered two‐phase system, an extraction rate of > 80 % is achieved when the glucose concentration is greater than 25 g/L.
A Comparison of Steam Reforming of Two Model Bio‐Oil Fractions
Authors: Wu C. , Sui M. , Yan Y.‐J. 
Published: November 2008

AbstractTwo model bio‐oil fractions were chosen as two different major classes of components present in bio‐oil. Steam reforming of the two fractions was carried out to investigate the gas product distributions and carbon deposition behavior. Higher H2 yield and carbon conversion to the gaseous phase can be obtained at relatively low temperature (650 °C) for steam reforming of the light fraction. For steam reforming of the heavy fraction, a higher temperature (800 °C) is necessary to obtain higher H2 yield and carbon conversion to the gaseous phase. At 800 °C, the heavy fraction requires a higher steam to carbon ratio (10) than that for the light fraction (7) to achieve efficient steam reforming. Based on the same carbon space velocity, for 10 h stream time, the drop of H2 yield and carbon conversion to the gaseous phase in the steam reforming of the heavy fraction is more rapid than that of the light fraction. Carbon deposition in the steam reforming of the heavy fraction is much more severe than that of the light fraction, as determined by carbon content analysis and SEM detection.
Synthesis and Toluene Adsorption/Desorption Property of Beta Zeolite Coated on Cordierite Honeycomb by an In Situ Crystallization Method
Authors: Zhang Y. , Su Q. , Wang Z. , Yang Y. , Xin Y. , Han D. , Yang X. , Wang H. , Gao X. , Zhang Z. 
Published: November 2008

AbstractThe beta zeolite on cordierite ceramic monolith was synthesized by an in situ crystallization method and characterized by XRD, N2 adsorption/desorption, SEM and NH3‐TPD techniques. Toluene adsorption/desorption was used as probe test for the control of cold‐start emissions and treatment of volatile organic compounds. The presence of beta on the supports was confirmed by XRD, SEM, and N2 adsorption/desorption measurements. The zeolite crystals grow both into the cordierite macropores and on the surface of the monolith channels, which form an integrated network ensuring a strong adherence. The highly dispersed beta on supports, demonstrated by larger surface area and adsorption capacity of N2, resulted in a significant increase of the total acidity, and thus a greater adsorption capacity for toluene. Furthermore, it could trap larger amounts of toluene to higher temperature and show considerable activity for toluene cracking and oxidation. These are attributed to the greater acidity and stronger acid sites of in situ synthesized beta.
Estimations of Gas Flow Maldistribution in Packed‐Bed Columns
Authors: Petrova T. , Darakchiev R. , Semkov K. , Darakchiev S. 
Published: November 2008

AbstractA review of research articles dealing with estimation of the rate of gas flow maldistribution in packed‐bed columns is presented. The proposed relations for determination of the maldistribution factor are given along with the conditions at which they are obtained. It is shown that the indices of maldistribution are usually based on particular terms, i.e., variation coefficient, dispersion or standard deviation. However, they cannot be regarded as a single indicator of gas maldistribution if the gas flow irregularities are not homogeneously distributed over the cross‐section. There is no unified methodology for measuring the gas flow velocity profile. Schemes for measuring the velocity profiles, as well as equations for calculating the maldistribution factor are recommended.
A Practical Method to Estimate the Bed Height of a Fluidized Bed of Fine Particles
Authors: Zhang Y. M. , Lu C. X. , Shi M. X. 
Published: November 2008

AbstractKnowledge of both dense bed expansion and freeboard solids inventory are required for the determination of bed height in fluidized beds of fine particles, e.g., Fluidized Catalytic Cracking (FCC) catalysts. A more accurate estimation of the solids inventory in the freeboard is achieved based on a modified model for the freeboard particle concentration profile. Using the experimentally determined dense bed expansion and the modified freeboard model, a more practical method with improved accuracy is provided to determine the bed height both in laboratory and industrial fluidized beds of FCC particles. The bed height in a fluidized bed can exhibit different trends as the superficial gas velocity increases, depending on the different characteristics of the dense bed expansion and solids entrainment in the freeboard. The factors that influence the bed height are discussed, showing the complexity of bed height and demonstrating that it is not realistic to determine the bed height by a generalized model that can accurately predict the dense bed expansion and freeboard solids inventory simultaneously. Moreover, a method to determine the bed height, based on axial pressure fluctuation profiles, is proposed in this study for laboratory fluidized beds, which provides improved accuracy compared to observation alone or determining the turning points in the axial pressure profiles, especially in high‐velocity fluidized beds.
Modeling of Gravitational Wet Scrubbers with Electrostatic Enhancement
Authors: Zhao H. , Zheng C. G. 
Published: November 2008

AbstractConventional gravitational wet scrubbers, which generally perform removal of fine particles with low efficiency, cannot meet new standards for pollution emissions. One way of improving the collection efficiency of fine particles is to impose additional electrostatic forces upon particles by means of particle‐charging, or droplet‐charging, or even opposite‐charging of particles and droplets. A Monte Carlo method for population balance modeling is presented to describe the particle removal processes of gravitational wet scrubbers with electrostatic enhancement, in such a way that the grade collection efficiency and particle size distribution are calculated quantitatively. Numerical results show that, the grade collection efficiency of submicron particles is only ca. 5 % in conventional wet scrubbers. However, it reaches ca. 25 % in particle‐charging wet scrubbers, ca. 70 % in droplet‐charging wet scrubbers, and even above 99 % in opposite‐charging wet scrubbers. Furthermore, population balance modeling is used to optimize the operational parameters of the droplet‐charging wet scrubbers by means of the quantitative comparison of the grade collection efficiency. It is found that the operational parameters that are beneficial to the high‐efficiency removal of fine particles are faster gas velocity, slower droplet velocity, larger liquid‐to‐gas flow ratio, larger charge‐to‐mass ratio of droplets, smaller geometric mean diameter and smaller geometric standard deviation of droplets.
Measuring Mixing Time in the Agitation of Non‐Newtonian Fluids through Electrical Resistance Tomography
Authors: Pakzad L. , Ein‐Mozaffari F. , Chan P. 
Published: November 2008

AbstractElectrical resistance tomography (ERT), which is a non‐invasive and robust measurement technique, was employed to visualize, in three dimensions, the concentration field inside a cylindrical mixing vessel equipped with a radial‐flow Scaba 6SRGT impeller. The ability of ERT to work in opaque fluids makes this technique very attractive from an industrial perspective. An ERT system with a 4‐plane assembly of peripheral sensing rings, each containing 16 electrodes, was used to measure the mixing time in agitation of xanthan gum solution which is a pseudoplastic fluid with yield stress. An image reconstruction algorithm was used to generate images of the tracer distribution within the sensing zone. In this study, the effect of impeller speed, fluid rheology, power consumption, and Reynolds number on the mixing time was investigated.
Regioselective Reactivity of an Asymmetric Tetravalent Di[dihydroxotin(IV)] Bis‐Porphyrin Host Driven by Hydrogen‐Bond Templation
Authors: Brotherhood Peter R. , Luck Ian J. , Blake Iain M. , Jensen Paul , Turner Peter , Crossley Maxwell J. 
Published: November 2008

AbstractLocal molecular environment effects on the rates of ligand exchange at an asymmetric di[dihydroxotin(IV)] bis‐porphyrin 5 are examined. The host 5 possesses four non‐equivalent tin(IV)–ligand binding sites that are distinguished by their position relative to a shallow cavity, by the steric environment at each binding site and by electronic‐structure differences between the constituent porphyrin and quinoxalinoporphyrin macrocycles. These design features of the asymmetric host are confirmed by X‐ray crystal structure analysis. Binding experiments with monodentate carboxylic acids and bidentate dicarboxylic acids show significant differences in the rate of ligand exchange at each of the four tin(IV) binding sites. For monodentate carboxylic acids, binding preferentially occurs at the exterior porphyrin site. Further addition of carboxylic acid results in sequential binding at the quinoxalinoporphyrin sites and lastly at the interior site on the porphyrin, with high regioselectivity. These selective binding outcomes are immediately apparent by NMR spectroscopy. A series of 2D NMR spectroscopy experiments allowed identification of the preferred binding sites at the host. This positively identifies that steric hindrance and electron‐withdrawing functionality on the porphyrin macrocycle impede ligand exchange. However, these effects are overcome by dicarboxylic acid guests, which form ditopic hydrogen‐bond interactions between the intracavity hydroxo ligands in the initial stage of ligand exchange, leading to regioselective binding between the tin(IV) sites within the cavity. It is envisaged that the factors identified herein that define regioselective ligand exchange at host 5 will find wider application in supramolecular systems incorporating tin(IV) porphyrins.
ChemInform Abstract: (M,Bi)46V8Oy‐Family Type (M: Pb, Sr, Ca, Cd, Na0.5Bi0.5): Syntheses, Crystal Structures and Conductivity Properties.
Authors: Labidi Olfa , Drache Michel , Roussel Pascal , Wignacourt Jean‐Pierre 
Published: November 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.