bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cirrhosis ameliorates monocrotaline-induced pulmonary hypertension in rats
Authors: Le Pavec J. , Perros F. , Eddahibi S. , Decante B. , Dorfmuller P. , Sitbon O. , Lebrec D. , Humbert M. , Mazmanian M. , Herve P. 
Published: March 2009

Common bile duct ligation (CBDL) induces biliary cirrhosis and pulmonary vasodilatation. We tested whether CBDL ameliorates monocrotaline (MCT)-induced pulmonary hypertension (PH) in rats.Five groups of rats were studied: controls; rats dosed with MCT (60 mg·kg−1subcutaneously); CBDL; rats dosed with MCT followed by CBDL on day 7; and rats dosed with MCT followed by CBDL (day 7) andL-NAME therapy between days 24 and 28. 28-day survival was 26% in the MCT group and 72% in the MCT+CBDL group. Pulmonary vascular resistance measured on days 21 and 28 increased in the MCT and MCT+CBDL+L-NAME groups, but returned to normal in the MCT+CBDL group on day 28. Pulmonary artery (PA) medial hypertrophy persisted in MCT+CBDL rats. PA inflammation increased in MCT+CBDL rats, with accumulation of both intra- and perivascular macrophages. Exhaled nitric oxide (NO) levels decreased in the MCT group and increased in the MCT+CBDL group, which showed upregulation of inducible NO synthase and normal endothelial NO synthase. Blood endothelin (ET)-1 increased in CBDL, MCT, and MCT+CBDL rats. Levels of ETBreceptors increased and ETAreceptors decreased in the MCT+CBDL group, whereas the opposite changes occurred in the MCT group.Biliary cirrhosis induces pulmonary vasodilation that ameliorates MCT-induced PH and improves survival. Upregulation of inducible NO synthase and ETBreceptor and downregulation of ETAreceptor may be involved.
Titrated mandibular advancementversuspositive airway pressure for sleep apnoea
Authors: Gagnadoux F. , Fleury B. , Vielle B. , Pételle B. , Meslier N. , N’Guyen X. L. , Trzepizur W. , Racineux J. L. 
Published: March 2009

The aim of this study was to compare mandibular advancement device (MAd) therapy and continuous positive airway pressure (CPAP) for obstructive sleep apnoea/hypopnoea syndrome (OSAHS) after one-night polysomnographic (PSG) titration of both treatments.59 OSAHS patients (apnoea/hypopnoea index (AHI): 34±13 events·h−1; Epworth scale: 10.6±4.5) were included in a crossover trial of 8 weeks of MAd and 8 weeks of CPAP after effective titration. Outcome measurements included home sleep study, sleepiness, health-related quality of life (HRQoL), cognitive tests, side-effects, compliance and preference.The median (interquartile range) AHI was 2 (1–8) events·h−1with CPAP and 6 (3–14) events·h−1with MAd (p<0.001). Positive and negative predictive values of MAd titration PSG for treatment success were 85% and 45%, respectively. Both treatments significantly improved subjective and objective sleepiness, cognitive tests and HRQoL. The reported compliance was higher for MAd (p<0.001) with >70% of patients preferring this treatment.These results support titrated MAd as an effective therapy in moderately sleepy and overweight OSAHS patients. Although less effective than CPAP, successfully titrated MAd was very effective at reducing the AHI and was associated with a higher reported compliance. Both treatments improved functional outcomes to a similar degree. One-night titration of MAd had a low negative predictive value for treatment success.
G-allele of Intronic rs10830963 inMTNR1BConfers Increased Risk of Impaired Fasting Glycemia and Type 2 Diabetes Through an Impaired Glucose-Stimulated Insulin Release
Authors: Sparsø Thomas , Bonnefond Amélie , Andersson Ehm , Bouatia-Naji Nabila , Holmkvist Johan , Wegner Lise , Grarup Niels , Gjesing Anette P. , Banasik Karina , Cavalcanti-Proença Christine , Marchand Marion , Vaxillaire Martine , Charpentier Guillaume , Jarvelin Marjo-Riitta , Tichet Jean , Balkau Beverley , Marre Michel , Lévy-Marchal Claire , Færch Kristine , Borch-Johnsen Knut , Jørgensen Torben , Madsbad Sten , Poulsen Pernille , Vaag Allan , Dina Christian , Hansen Torben , Pedersen Oluf , Froguel Philippe 
Published: March 2009

OBJECTIVEGenome-wide association studies have identified several variants within the MTNR1B locus that are associated with fasting plasma glucose (FPG) and type 2 diabetes. We refined the association signal by direct genotyping and examined for associations of the variant displaying the most independent effect on FPG with isolated impaired fasting glycemia (i-IFG), isolated impaired glucose tolerance (i-IGT), type 2 diabetes, and measures of insulin release and peripheral and hepatic insulin sensitivity.RESEARCH DESIGN AND METHODSWe examined European-descent participants in the Inter99 study (n = 5,553), in a sample of young healthy Danes (n = 372), in Danish twins (n = 77 elderly and n = 97 young), in additional Danish type 2 diabetic patients (n = 1,626) and control subjects (n = 505), in the Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) study (n = 4,656), in the North Finland Birth Cohort 86 (n = 5,258), and in the Haguenau study (n = 1,461).RESULTSThe MTNR1B intronic variant, rs10830963, carried most of the effect on FPG and showed the strongest association with FPG (combined P = 5.3 × 10−31) and type 2 diabetes. The rs10830963 G-allele increased the risk of i-IFG (odds ratio [OR] 1.64, P = 5.5 × 10−11) but not i-IGT. The G-allele was associated with a decreased insulin release after oral and intravenous glucose challenges (P &lt; 0.01) but not after injection of tolbutamide. In elderly twins, the G-allele associated with hepatic insulin resistance (P = 0.017).CONCLUSIONSThe G-allele of MTNR1B rs10830963 increases risk of type 2 diabetes through a state of i-IFG and not through i-IGT. The same allele associates with estimates of β-cell dysfunction and hepatic insulin resistance.
Kinetics and modeling of charge transfer polymerization of methyl methacrylate
Authors: Rao P. G. , Vijayaraghavan R. , Raghavan K. V. , Sai P.S.T. 
Published: March 2009

AbstractThe charge transfer polymerization of methyl methacrylate (MMA) in presence of n‐butyl amine (nBA) and carbon tetrachloride (CCl4) with dimethyl sulfoxide (DMSO) as solvent was experimentally investigated. The variables include concentrations of MMA, nBA, CCl4, DMSO and reaction temperature. The effect of these variables on monomer conversion, number and weight average molecular weights is discussed. A reaction mechanism is proposed and overall kinetics, propagation, chain transfer and termination constants are evaluated. A mathematical model is proposed for estimating monomer conversion, number and weight average molecular weights. The proposed model is validated using the kinetic constants and compared satisfactorily with experimental data of the present study. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Bestimmung des Diffusionskoeffizienten mittels Fließinjektionsanalyse
Authors: Kiefer J. , Leipertz A. 
Published: March 2009

AbstractVermischungsprozesse spielen in praktisch allen verfahrenstechnischen Anlagen eine wichtige Rolle. Im Bereich der Stoffdatenforschung ist es daher von großer Bedeutung, Parameter wie den molekularen Diffusionskoeffizienten zu bestimmen. Im Rahmen des Beitrags wird die Fließinjektionsanalyse (FIA) als Methode zur Messung des Diffusionskoeffizienten vorgestellt und am Beispiel des Lebensmittelfarbstoffes E150d (Ammoniumsulfit‐Zuckercouleur) erprobt.
The bubble behavior in the gas‐solids fluidized bed
Authors: Yutani N. , Fan L. T. , Ho T. C. 
Published: March 2009

AbstractThe bubbling frequency in a gas‐solids fluidized bed and its stochastic variation along the axial direction of the bed were determined by means of the capacitance method. The stochastic model proposed, more specifically a pure‐death process, appears to be capable of describing the resultant data well.
A general correlation for the minimum spouting velocity
Authors: Littman H. , Morgan M. H. 
Published: March 2009

AbstractA new general correlation is presented for the minimum spouting velocity based on the annular pressure gradient at the top of the bed at minimum spouting. The correlation fits a wide range of experimental data to 11.6% on average. The normalized minimum spouting velocity ratio. umS/umF, is shown to be a function of three dimensionless parameters.
A probe for point velocities in slurry flows
Authors: Brown N. P. , Shook C. A. , Peters J. , Eyre D. 
Published: March 2009

AbstractA probe and measuring system for determing local values of particle velocity in liquid‐solids mixtures has been constructed and tested. The probe uses the cross‐correlation principle. Its performance was found to depend upon the scale of the concentration fluctuations which occur in the flow. Probe geometry was also found to be of importance. Volumetric flowrate measurements indicated that an accuracy of 3% could be achieved.The probe should be of value in the study of two‐phase flows.
Influence of forced feed composition cycling on the rate of ammonia synthesis over an industrial iron catalyst part I — Effect of cycling parameters and mean composition
Authors: Jain A. K. , Hudgins R. R. , Silveston P. L. 
Published: March 2009

AbstractStudies have been carried out at 2.38 MPa total pressure and at 360 and 400°C of the synthesis of ammonia over a triply‐promoted iron catalyst (United Catalysts Inc.). Runs were carried out using a gradientless reactor in steady‐state and periodic modes, the latter employing forced composition cycling. The catalyst had a particle diameter of 0.30 mm; the resulting reaction rates were free from transport intrusions. The range of mean compositions for steady‐state measurements was from 0.1 to 0.9 mole fraction of hydrogen and for periodic operation from 0.5 to 0.9. The cycle‐split ratio (used to describe non‐uniform cycling) varied from 0.2 to 0.85. Effects of cycle period, mean composition, cycle‐split, and temperature were investigated. Instantaneous rate variations within the cycle are reported.Results showed that the cycling mode of operation results in an improvement in the time‐average rate of ammonia formation of up to 30%, depending upon the choice of operating parameters. Some implications for the mechanism of ammonia synthesis under periodic operation are presented.
Hydrodynamics of a mobile bed contactor with ‘Low’ density packing particles of different shapes
Authors: Rama O. P. , Rao D. P. , Rao V. Subba 
Published: March 2009

AbstractExperimental studies have been reported on pressure drop, liquid holdup, bed expansion and minimum fluidization velocity in a 0.15 m ID mobile bed of relatively low density (53–183 kg m−3) spherical and irregular shaped particles. The Kito‐Tabei‐Murata correlation has been adapted to fit the data on the liquid holdup and the pressure drop. The bed expansion was found to depend on the shape and density of the particles. It is shown that, in general, only a part of the liquid holdup in the bed is supported by the upward flow of gas. It was observed that in some regions the particles congregated at the wall, leaving a particle free core. The maps depicting these regions are presented.
An observation of microbial cell accumulation in a finned tube
Authors: Turakhia M. , Characklis W. G. 
Published: March 2009

AbstractBiofouling in heat exchange equipment results in significant energy loss by increasing heat transfer resistance and fluid frictional resistance. This paper compares the deposition and distribution of attached microbial cells on a smooth tube and a tube with inner fins after 100 hours exposure. Preliminary results suggest a significantly different distribution of attached microbial cells on the finned tube.
Die swell experiments for newtonian fluids
Authors: Hill G. A. , Chenier C. L. 
Published: March 2009

AbstractThe swelling and shrinking of Newtonian jets issuing from circular orifices or slits are examined. Equations predicting the die swell ratio and downstream flow characteristics are developed. It is found that the cause of swelling at low Reynolds numbers is related to a negative pressure (below the free stream pressure) at the slit exit. The scatter of experimental data has been studied and the factors contributing to this phenomenon are discussed. The die swell ratios and jet shapes versus Reynolds number for Newtonian liquids issuing from tubes are empirically shown.
Design of transient experiments for identification of fixed bed thermal transport properties
Authors: Murray Larry E. , Reiff E. K. 
Published: March 2009

AbstractThe utility of using optimal input signals to improve the parametric information content in a transient experiment is explored. This work extends the statistical design concepts that have proven useful in steady state model building studies to a dynamic environment. The methodology is demonstrated for the identification of thermal transport properties in an adiabatic packed bed. The effects of the choice of measurements, initial parameter values and accuracies, and performance criteria are assessed. The results indicate that optimal dynamic experiments can offer considerable improvement over present practice.
Measurement of slurry concentration and flow rates in shell and tube slurry heat exchangers
Authors: Moujaes Samir F. 
Published: March 2009

AbstractA study has been conducted on a slurry flow behavior in vertical tubes having diameters of one inch in an upflow mode. A tube sampling technique and an optical electronics method were developed to determine the slurry concentration and flow rates for flurries comprised of different size particles. These methods will be applied in cold flow simulation of a shell and tube slurry heat exchanger.
Mass transfer in aerated fermentation broths in a stirred tank reactor
Authors: ČIč R. Jure , Berovič M. , Steiner W. , Koloini T. 
Published: March 2009

AbstractThe volumetric mass transfer coefficients, kLa, measured in a pilot plant (0.1 m3) and an industrial (67.5 m3) fermentor during an actual fermentation process are presented. Problems related to the estimation of the phsyical properties as well as to the correlation of experimental data and to scale up procedures are discussed. Although the scale up factor was rather high, both sets of data could be represented by single correlation. Comparison of the experimental data with several available correlations demonstrated the need for pilot plant experiments and scale up procedures, since it is almost impossible to take into account all relevant system properties.
Solid hold‐up in bubble columns with suspended solid particles under continuous operation
Authors: Kojima H. , Iguchi A. , Asano K. 
Published: March 2009

AbstractSolid hold‐up in bubble columns with suspended solid particles was studied experimentally under continuous slurry feed for the system, air–water–glass beads, in two columns of 55 mm and 95 mm in diameter. Experimental results agree well with the prediction made on the basis of the one‐dimensional dispersion model.
Analysis of the performance of a simulated counter‐current chromatographic system for fructose – glucose separation
Authors: Ching C. B. , Ruthven D. M. 
Published: March 2009

AbstractThe adsorptive separation of fructose from glucose has been carried out in a simulated counter‐current chromatographic system using Zerolit‐25SCR14 ion exchange resin in Ca++ form as the adsorbent. Rate and equilibrium constants have been determined from chromatographic retention time measurements. The performance of a simulated counter‐current system comprising ten identical columns connected in series has been investigated and it is shown that the behaviour of such a system may be approximately represented by a simple McCabe–Thiele model. The HETP in the counter‐current system is higher than would be expected for an ideal plug flow system, showing that axial mixing is important. The McCabe–Thiele analysis may be easily extended to a four section ‘Sorbex’ system and a preliminary assessment of the performance of such a unit is made on the basis of the kinetic and equilibrium parameters derived from the experimental study.
Adsorptive separation of Kr from N2 — Part I Adsorbent screening studies
Authors: Ruthven D. M. , Tezel F. H. , Devgun J. S. , Sridhar T. S. 
Published: March 2009

AbstractResults of a chromatographic study of the adsorption of N2 and Kr on several molecular sieve adsorbents are reported. The objective was to find a suitable adsorbent for the removal of traces of radioactive Kr from the off‐gas from nuclear fuel reprocessing facilities. Of the adsorbents examined, de‐aluminated H‐mordenite shows the highest selectivity for Kr relative to N2 and appears to be a promising adsorbent for this separation. The presence of traces of NO2, a likely impurity in the off‐gas, was found to suppress the adsorption of N2 more than that of Kr, thereby increasing the separation factor (α ∼ 12). In most of the adsorbents investigated, intracrystalline diffusion was too fast to measure but for N2 in H‐mordenite, intracrystalline resistance was found to be significant and strongly dependent on the initial dehydration temperature.
The catalytic cracking of a fischer‐tropsch synthesis product
Authors: Kobolakis I. , Wojciechowski B. W. 
Published: March 2009

AbstractThe use of a feed mostly composed of linear alkanes ranging from C5 to C30 has made it clear that initiation of catalytic cracking does not proceed on very strong Bronsted sites with the liberation of hydrogen. It has also shown that cracking of the linear molecules probably occurs on the first active site inside a zeolite pore with the result that the products formed lie almost totally in the C4 to C10 range and are highly isomerized.
A turbulence closure model for dilute gas‐particle flows
Authors: Chen C. P. , Wood P. E. 
Published: March 2009

AbstractA second order closure scheme is developed for the numerical prediction of isothermal, non‐reacting, mono‐dispersed, dilute gas‐particle turbulent shear flows. The model is based on the two‐equation (κ‐ϵ) turbulence model developed for calculating the analogous gas‐phase flows. Contrary to passive additives in a single phase flow, the particles will affect the turbulence structure of the continuous phase. Thus, the κ‐ϵ model has been modified to account for the presence of the dispersed particles. In particular, the particles increase the dissipation rate because of the relative velocity fluctuations between the two phases. New proposals for these added effects based on particle size and loading are added to these equations. The resulting model is used to compute the axisymmetric jet in its developing region. The calculated jet spreading rate, centre‐line velocity decay and entrainment rate are all in excellent agreement with published experimental data. Calculated turbulence quantities such as the kinetic energy and mean Reynolds shear stress are greatly reduced from their “clean jet” levels by the presence of the particles in good agreement with the available experimental data.
The mechanism of catalytic cracking of n‐alkenes on ZSM‐5 zeolite
Authors: Abbot J. , Wojciechowski B. W. 
Published: March 2009

AbstractThe catalytic cracking of n‐alkenes on ZSM‐5 zeolite at 405°C can occur both by a monomolecular mechanism and a bimolecular process. In the latter, cracking is preceeded by dimerization. We show that pentenes are cracked exclusively by the bimolecular process. The dominant cracking mechanism for n‐hexenes also requires initial dimerization, although a small proportion (<19%) of the total cracking may proceed by a monomolecular process. Cracking of n‐heptenes is predominantly monomolecular, with only 13% of the total occurring via an initial dimer formation. The cracking of n‐octenes and n‐nonenes can be interpreted by assuming a monomolecular mechanism only. Thus it appears that at 405°C olefins smaller than C6 are stable with respect to direct cracking and must dimerize before a species is formed which is unstable enough to crack.No molecular hydrogen was produced in any of the cracking reactions reported here in the range of conversions studied.
Effect of substance‐dependent Ωac on vapor‐liquid equilibrium calculations
Authors: Adachi Yoshinori , Sugie Hidezumi , Lu Benjamin C.‐Y. 
Published: March 2009

AbstractThe role of the dimensionless quantity Ωa (= aPc/R2T) at the critical points of pure substances, Ωac, on the representation of binary vapor—liquid equilibrium values was investigated using a two‐parameter cubic equation of state together with conventional mixing rules.A two‐Ωac method was proposed to improve the representation of the equilibrium values in the critical region by considering the value of Ωac substance dependent. The limitations of the proposed method was also presented.
Settling stability of coal slurries prepared by wet grinding in the szego mill
Authors: Koka V. R. , Papachristodoulou G. , Trass O. 
Published: March 2009

AbstractStatic sedimentation experiments on coal‐#2 oil and coal‐water slurries, wet ground in a Szego mill, were conducted. These slurries contain more flaky particles as compared to those conventionally ground.Concentration and size distribution of the coal, diameter and height of the settling columns and settling time were the independent variables. Coal concentration and particle size distribution along the columns, and settling rates were measured.Despite their particle shape differences, these slurries were similar to others in terms of settling stability due to particle flocculation.
Further aspects of powdered poplar wood liquefaction by aqueous pyrolysis
Authors: Boocock D. G. B. , Sherman K. M. 
Published: March 2009

AbstractThe liquefaction of powdered poplar wood by rapid pyrolysis in water at 350°C has been studied further. It differs significantly from the liquefaction of wood chips in that oil yields are improved by pressurisation of the reactor. Oil yields (chloroform soluble) are about 45 per cent and are sensitive to water/wood mass ratios and residence time. Gas, measured in a new handling system, is produced in 5–12 per cent mass yields and contains 86–90 per cent carbon dioxide and 10–13 per cent carbon monoxide. The oil and aqueous phases contain carboxylic acids (particularly acetic), phenols, cyclohexanones, cyclopentanones, benzyl alcohols and furfural.
Computer control of continuous immobilized cell penicillin fermentations: Simulation studies
Authors: Kalogerakis Nicolas , Unardos Theodor , Behie Leo A. , Svrcek William Y. , Gaucher G. Maurice 
Published: March 2009

AbstractImmobilized cell technology provides a simple and promising alternative to submerged free cell fermentations for the production of antibiotics like penicillin‐G. Recently, our biotechnology group has successfully developed a three phase fluidized bed bioreactor that is capable of running in a continuous mode more than 600 h. As a direct follow‐up, we propose in this paper a simple process control system which will enable penicillin fermentations to run under any desired cell specific growth rate and penicillin concentration in the effluent stream. By implementing such a control scheme, the reactor productivity can be substantially increased, and hence, make continuous fermentations highly attractive economically.