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Selected AbstractsEffect of fatty acid-binding proteins on intermembrane fatty acid transportFEBS JOURNAL, Issue 19 2000Studies on different types, mutant proteins Liposomes of different charge fixed to nitrocellulose filters were used to study the transfer of fatty acids to rat heart or liver mitochondria in the presence of fatty acid-binding protein (FABP) or albumin. [14C]Palmitate oxidation was used as a parameter. Different FABP types and heart FABP mutants were tested. The charge of the liposomes did not influence the solubilization and mitochondrial oxidation of palmitate without FABP and the amount of solubilized palmitate in the presence of FABP. Mitochondria did not show a preference for oxidation of FABP-bound palmitate over their tissue-specific FABP type. All FABP types increased palmitate oxidation by heart and liver mitochondria with neutral, positive and negative liposomes by 2.5-fold, 3.2-fold and twofold, respectively. Ileal lipid-binding protein and H-FABP mutants that do not bind fatty acid had no effect. Other H-FABP mutants had different effects, dependent on the site of mutation. The effect of albumin was similar to, but not dependent on, liposome charge. The ionic strength had only a slight effect. In conclusion, the transfer of palmitate from liposomal membranes to mitochondria was increased by all FABP types to a similar extent. The membrane charge had a large effect in contrast to the origin of the mitochondria. [source] Serum amyloid A has antiviral activity against hepatitis C virus by inhibiting virus entry in a cell culture system,HEPATOLOGY, Issue 6 2006Muriel Lavie Serum amyloid A (SAA) is an acute phase protein produced by the liver. SAA concentration increases markedly in the serum following inflammation and infection. Large increases in SAA concentration during the acute phase response suggest that SAA has a beneficial role in host defense. This study sought to determine the effect of SAA on hepatitis C virus (HCV) infectivity using retroviral particles pseudotyped with HCV envelope glycoproteins (HCVpp) and the recently developed cell culture system for HCV (HCVcc). SAA inhibited HCVpp and HCVcc infection in a dose-dependent manner by affecting an early step of the virus life cycle. Further characterization with HCVpp indicated that SAA blocks virus entry by interacting with the viral particle. In addition, the antiviral activity of SAA was strongly reduced when high-density lipoproteins (HDL) were coincubated with SAA. However, HDL had only a slight effect on the antiviral activity of SAA when HCVpp was first preincubated with SAA. Furthermore, analyses of SAA in sera of chronic HCV patients revealed the presence of variable levels of SAA with abnormally elevated concentrations in some cases. However, no obvious clinical correlation was found between SAA levels and HCV viral loads. In conclusion, our data demonstrate an antiviral activity for SAA and suggest a tight relationship between SAA and HDL in modulating HCV infectivity. (HEPATOLOGY 2006;44:1626,1634.) [source] Correlations of flow maldistribution parameters in an air cooled heat exchangerINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 2 2008M. A. Habib Abstract The present paper provides correlations of flow maldistribution parameters in air-cooled heat exchangers. The flow field in the inlet header was obtained through the numerical solution of the governing partial differential equations including the conservation equations of mass and momentum in addition to the equations of the turbulence model. The results were obtained for different number of nozzles of 2,4, different inlet flow velocities of 1,2.5m/s and different nozzle geometries in addition to incorporation of a second header. The results are presented in terms of mass flow rate distributions in the tubes of the heat exchanger and their standard deviations. The results indicate that the inlet flow velocity has insignificant influence on maldistribution while the nozzle geometry shape has a slight effect. Also, the results indicate that reducing the nozzle diameter results in an increase in the flow maldistribution. A 25% increase is obtained in the standard deviation as a result of decreasing the diameter by 25%. Increasing the number of nozzles has a significant influence on the maldistribution. A reduction of 62.5% in the standard deviation of the mass flow rate inside the tubes is achieved by increasing the number of nozzles from 2 to 4. The results indicate that incorporating a second header results in a significant reduction in the flow maldistribution. A 50% decrease in the standard deviation is achieved as a result of incorporation of a second header of seven holes. It is also found that the hole-diameter distribution at the exit of the second header has a slight influence on the flow maldistribution. Correlations of the flow maldistribution in terms of the investigated parameters are presented. Copyright © 2007 John Wiley & Sons, Ltd. [source] Computational study of a novel continuous solar adsorption chiller: performance prediction and adsorbent selectionINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 10 2007Evan Voyiatzis Abstract A novel solar adsorption chiller intended for domestic use is presented. The chiller can be integrated with existing solar systems based on flat plate collectors, and, contrary to commercial chillers, it operates continuously. A detailed analysis of both the simple and the heat-integrated cycle is carried out so as to select the optimal adsorbent and operating conditions. The employed integral thermodynamic model takes into account the inert masses that limit the performance of the chiller, such as the metal frame, the thermo-fluid, and the non-adsorbed steam, by introducing heat capacity effects. Given the adsorption equilibrium data, the energy balances, the performance, and the useful thermal loads of the system can be calculated at any operating conditions. The results indicate that silica gel Type A is a more efficient adsorbent compared to silica gel Type RD or Type 3A. Furthermore, the total porosity has a slight effect on system performance, while optimal operation can be achieved when the condenser temperature is less than 326 K and the evaporator temperature greater than 280 K. Copyright © 2006 John Wiley & Sons, Ltd. [source] Effects of extrusion conditions on quality of cassava bran/cassava starch extrudatesINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2003Jorge Minoru Hashimoto Summary Blends of cassava bran and cassava starch were processed in a single-screw extruder. Response surface methodology was used to determine the effect of the concentration of cassava bran (10,50%), barrel temperature (150,210 °C), feed moisture (16,20%) and screw speed (120,180 r.p.m.) on the characteristics of the dried extrudates. All the independent variables were significant (P < 0.05) for radial expansion. The water absorption index (WAI) and water solubility index (WSI) were affected by bran level, screw speed and temperature, while only moisture and temperature influenced specific volume. The maximum radial expansion was found when all the independent variables were at their lowest levels. Lowest-density extrudates (highest specific volume) were obtained at 16,18% moisture and 180,200 °C. An increase in bran level increased the WAI but decreased the WSI when the temperature was higher than 170 °C . Screw speed had a slight effect on those responses, decreasing water absorption and increasing water solubility when changed from 120 to 180 r.p.m. [source] High temperature copolymerization of styrene/ethyl acrylate: Reactivity ratio estimation in bulk and solutionADVANCES IN POLYMER TECHNOLOGY, Issue 3 2004Nahla Sahloul Abstract Styrene/ethyl acrylate (Sty/EA) free-radical copolymerizations have been conducted in bulk with and without initiator and in solution using p -xylene and m -xylene (30 wt% and 60 wt% solvent level) at 100°C and 130°C. The monomer reactivity ratio values and their temperature dependence have been determined from low conversion copolymer composition data using the computer software package RREVM, which is based on the error in variables model (EVM) method. Copolymer composition data at low conversion confirmed the Mayo,Lewis model at both temperatures. The reactivity ratio values of the Sty/EA system do not seem to change with dilution by nonpolar solvents at low concentration from the reactivity ratio values obtained in bulk with and without initiator. However, xylene isomers were found to have a slight effect on the reactivity ratio value of ethyl acrylate when high solvent concentration was utilized. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 186,195, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20009 [source] Solubility and phase separation of poly(L,D -lactide) copolymersJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2008Marja Rissanen Abstract In this study, the solubility and precipitation properties of medical-grade stereocopolymers were investigated. The solubility of the polymers was tested with eight different organic solvents and four nonsolvents. The solubility of poly(L,D -lactide) stereocopolymers was highly dependent on the L/D ratio of the copolymer. The phase-separation ability was tested by cloud-point titration with a solvent and a nonsolvent. The solvent was in all cases dichloromethane, and the nonsolvents were n -hexane, methanol, ethanol, and isopropyl alcohol. The results showed that n -hexane was the most efficient nonsolvent. Methanol and ethanol showed quite similar precipitation properties. Isopropyl alcohol was the least efficient nonsolvent of those studied. Also, the L/D ratio of the copolymer had an effect on the precipitation properties. The precipitation happened most easily when the L content was high. The molecular weight of the copolymer had only a slight effect on the phase separation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Carboxylated multiwall carbon nanotube-reinforced thermotropic liquid crystalline polymer nanocompositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Sang Ki Park Abstract Thermotropic liquid crystalline polymer (TLCP) nanocomposites reinforced with carboxylated multiwall carbon nanotube (c-MWCNT) were prepared through melt compounding in a twin screw extruder. The thermal stability of TLCP/c-MWCNT nanocomposites increased with even a small amount of c-MWCNT added. The rheological properties of the TLCP/c-MWCNT nanocomposites were depended on the c-MWCNT contents. The contents of c-MWCNT have a slight effect on the complex viscosity of TLCP/c-MWCNT nanocomposites due to the high-shear thinning of TLCP. The storage modulus of TLCP/c-MWCNT nanocomposites was increased with increasing c-MWCNT content. This result can be deduced that the nanotube,nanotube interactions were more dominant, and some interconnected or network-like structures were formed in the TLCP/c-MWCNT nanocomposites. Incorporation of very small amount of c-MWCNT improved the mechanical properties of TLCP/c-MWCNT nanocomposites, and this was attributed to the reinforcement effect of c-MWCNT with high aspect ratio and their uniform dispersion through acid treatment in the TLCP matrix. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Paeoniae Radix, a traditional Chinese medicine, and CYP2C9 activityJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 3 2002Han-Jing Xie Paeoniae Radix (PR) is a commonly used traditional Chinese medicine. A slight effect of PR on the pharmacokinetics of phenytoin that is mainly metabolised by CYP2C9 has been reported. The aim of this pilot study was to clarify if PR has an effect on losartan oxidation used as a measure of CYP2C9 activity. Three healthy volunteers received a single oral dose of losartan before and after PR treatment. Losartan and E-3174, an active metabolite of losartan, were analysed in 8 hour urine. PR did not seem to have an effect on CYP2C9 activity when the losartan/E-3174 ratios were compared before and after PR treatment (P = 0·56) although a larger study would need to be undertaken to confirm this finding. [source] Spatial substituent effects of various fluorinated groups on the 13C chemical shifts in cyclohexanesMAGNETIC RESONANCE IN CHEMISTRY, Issue 3 2007Yvan Carcenac Abstract The effect of introduction of fluorinated groups (CH2F, CHF2, CF3, C2F5, OCF3, SCF3) on the 13C NMR chemical shifts in cyclohexanes is examined. The two main effects are caused by location at the , and , carbon positions. Comparison of the various data allowed the calculation of increments corresponding to the introduction of fluorinated groups at axial or equatorial positions on the cyclohexane ring. The introduction of fluorine atoms in methoxy and thiomethoxy groups has only a slight effect through the heteroatom on the 13C chemical shifts. Copyright © 2007 John Wiley & Sons, Ltd. [source] Effect of some granular insecticides currently used for the treatment of maize crops (Zea mays) on the survival of inoculated Azospirillum lipoferumPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 11 2001Cécile Revellin Abstract Four insecticides, carbofuran, chlormephos, terbufos and benfuracarb, currently used on maize (Zea mays) at sowing, were tested for their compatibility with Azospirillum lipoferum strain CRT1 used as an inoculant to improve maize growth and yield. The growth or survival of A lipoferum was studied in the presence of the insecticides: (1) in liquid and solid cultures of the bacteria, (2) when a commercial inoculant (Azogreen-mÔ, Liphatech, Meyzieu, France) was inoculated directly on insecticide granules, (3) when inoculated Azogreen-m granules were mixed with insecticide granules and (4) when inoculated Azogreen-m granules were delivered separately to the seed bed. Of the four insecticides tested, only terbufos had a slight effect on growth of A lipoferum in solid cultures. All the insecticides decreased the survival of A lipoferum when the bacteria were inoculated directly on to the granules, or when inoculated Azogreen-m granules were mixed with an insecticide. We hypothesize that the discrepancies between bacterial culture tests and survival studies might be explained by the conditions of desiccation encountered during inoculation of the granules. Desiccation stress could increase the toxic effect of the insecticides. We therefore suggest including desiccation stress in the biotest used to assess inoculant-pesticide compatibility. © 2001 Society of Chemical Industry [source] Molybdenum cofactor amounts in Chlamydomonas reinhardtii depend on the Nit5 gene function related to molybdate transportPLANT CELL & ENVIRONMENT, Issue 11 2000A. Llamas ABSTRACT Strain 21gr from Chlamydomonas reinhardtii is a cryptic mutant defective in the Nit5 gene related to the biosynthesis of molybdenum cofactor (MoCo). In spite of this mutation, this strain has active MoCo and can grow on nitrate media. In genetic crosses, the Nit5 mutation cosegregated with a phenotype of resistance to high concentrations of molybdate and tungstate. Molybdate/tungstate toxicity was much higher in nitrate than in ammonium media. Strain 21gr showed lower amounts of MoCo activity than the wild type both when grown in nitrate and after growth in ammonium and nitrate induction. However, nitrate reductase (NR) specific activity was similar in wild type and 21gr cells. Tungstate, either at nanomolar concentrations in nitrate media or at micromolar concentrations during growth in ammonium and nitrate induction, strongly decreased MoCo and NR amounts in wild-type cells but had a slight effect in 21gr cells. Molybdate uptake activity of ammonium-grown cells from both the wild-type and 21gr strains was small and blocked by sulphate 0·3 mM. However, cells from nitrate medium showed a molybdate uptake activity insensitive to sulphate. This uptake activity was much higher and more sensitive to inhibition by tungstate in the wild type than in strain 21gr. These results suggest that strain 21gr has a high affinity and low capacity molybdate transport system able to discriminate efficiently tungstate, and lacks a high capacity molybdate/tungstate transport system, which operates in wild-type cells upon nitrate induction. This high capacity molybdate transport system would account for both the stimulating effect of molybdate on MoCo amounts and the toxic effects of tungstate and molybdate when present at high concentrations. [source] Development time and survival of Verrallina funerea (Theobald) (Diptera: Culicidae) immatures and other brackish water mosquito species in southeast Queensland, AustraliaAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 3 2005Jason A L Jeffery Abstract,Verrallina funerea (Theobald) is a brackish water mosquito that is recognised as an important pest and vector in southeast Queensland, Australia. Immature development time and survival of Ve. funerea was defined in the laboratory in response to a range of temperatures (17,34°C) and salinities (0,35 parts per thousand (p.p.t)). The expression of autogeny in this species was also assessed. Salinity only had a slight effect on mean development time from hatching to adult emergence (7.0,7.4 d at salinities of 0, 17.5 and 31.5 p.p.t) and survival was uniformly high (97.5,99.0%). Mean development times were shorter at 26, 29 and 32°C (7.0, 6.8 and 6.8 d, respectively) and longest at 17°C (12.2 d). The threshold temperature (t) was 5.8°C and the thermal constant (K) was 142.9 degree-days above t. Survival to adulthood decreased from >95% (at 17,29°C) to 78% (at 32°C) and 0% (at 34°C). No expression of autogeny was observed. Immature development times of Ve. funerea, Ochlerotatus vigilax (Skuse) and Oc. procax (Skuse) were then determined under field conditions at Maroochy Shire. Following tide and rain inundation, cohorts of newly hatched larvae were monitored daily by dipping, and time until pupation was noted. Tidal inundation triggered hatching of Ve. funerea and Oc. vigilax larvae whereas Oc. procax larvae were found only after rain inundation. Estimates of Ve. funerea and Oc. vigilax field development times were similar (8,9 d) while Oc. procax development time was slightly longer (9,10 d). Based on these survey results, control activities targeting Ve. funerea must be initiated 4 d (if using Bacillus thuringiensis var. israelensis de Barjac) or 5 d (if using s -methoprene) after inundation. However, Casuarina glauca Sieber canopy and branchlets covering breeding habitats may present a problem for the penetration of such treatments. [source] Effect of polyphenols on the perception of key aroma compounds from Sauvignon Blanc wineAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 1 2009C.M. LUND Abstract Background and Aims:, Sensory wine research has mainly focused on the role of volatile compounds and their contribution to the aroma profile. Wines also contain polyphenolic compounds, which are not volatile. This research begins to investigate the interactions of volatile and non-volatile wine compounds and the consequential effects on sensory perception of aroma. Methods and Results:, Trained panellists of this study measured the perception of four aroma compounds (isobutyl methoxypyrazine, 3-mercaptohexanol, 3-mercaptohexanol acetate and ethyl decanoate) in wine. Panellists assessed the four compounds in combinations with three polyphenols (catechin, caffeic acid and quercetin) commonly found in white wine. The perception of isobutyl methoxypyrazine, 3-mercaptohexanol and ethyl decanoate was largely suppressed by the added polyphenols, while the perception of 3-mercaptohexanol was accentuated with the addition of caffeic acid. Of the three polyphenols, only catechin had a slight effect of accentuating the mercaptohexanol acetate perception. Conclusions:, Results showed each polyphenol had a unique effect when blended with a specific aroma compound, either suppressing, accentuating or showing little effect on the perception of the aroma compounds. Significance of the Study:, Understanding these interactions can assist winemakers in managing polyphenol levels to optimize selected volatile compounds to achieve desirable aroma profiles. [source] Enhanced radiation response of a solid tumor with the artificial oxygen carrier ,albumin-heme'CANCER SCIENCE, Issue 6 2008Hirohisa Horinouchi Tumor-cell hypoxia is one of the main factors inducing radioresistance. Enhanced tumor oxygenation has previously been achieved in an animal model using the synthetic heme-based oxygen carrier ,albumin-heme' (recombinant human serum albumin-Fe cyclohexanoil heme; rHSA-FeP). The present study was done to determine whether rHSA-FeP enhances the radiation response in an experimental tumor model. Male Donryu rats and LY80, a variant of the syngenic liver ascites tumor, were used. A total of 1 × 106 cells were injected into the subfascial tissue of the right thigh. The rats were divided randomly into five groups: sham (tumor implantation and sham operation); rHSA-FeP; irradiation; rHSA + irradiation; and rHSA-FeP + irradiation. Six days after, under general anesthesia, intra-arterial administration of 10 mL/kg of either 5% rHSA solution or oxygenated rHSA-FeP solution at 2.5 mL/min was done and a dose of 20 Gy was given. There were significant differences in tumor growth between the sham and irradiation groups, and between the sham and rHSA-FeP + irradiation groups. Tumor growth delay was observed and differences were significant between the sham and irradiation groups, and between the irradiation and rHSA-FeP + irradiation groups. In the present study, rHSA-FeP itself had a slight effect on tumor growth without irradiation. Enhancing the effect of rHSA-FeP on the radiation response is responsible in part for the oxygen-carrying property of rHSA-FeP. In conclusion, rHSA-FeP is a candidate radiation-enhancing drug. Arterial infusion of rHSA-FeP may serve as a local oxygenation method that enhances the radiation effect. (Cancer Sci 2008; 99: 1274,1278) [source] | |||||||||||||||||||