Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailKinetic study of the acid hydrolysis of various oligofructose samples
Blecker, Christophe ULg; Fougnies, C.; Van Herck, J. C. et al

in Journal of Agricultural and Food Chemistry (2002), 50(6), 1602-1607

The kinetic of acid hydrolysis of five commercially available oligofructose samples used as food ingredients has been investigated as a function of the dry matter concentration, reaction pH, and ... [more ▼]

The kinetic of acid hydrolysis of five commercially available oligofructose samples used as food ingredients has been investigated as a function of the dry matter concentration, reaction pH, and temperature. The initial fructose release rate is found to be roughly proportional to the inverse of the average polymerization degree in number. A pseudo first order kinetic is found with respect to the fructosyl chain end concentration and to the proton concentration. Arrhenius plot is found to reasonably fit the data in a relatively wide temperature range (7-130 degreesC). The results allow the estimation of the fructose release rate in many foodstuff processing conditions. [less ▲]

Detailed reference viewed: 34 (7 ULg)
Full Text
Peer Reviewed
See detailKinetic study of the antibody response during the blood meal of Ixodes ricinus: Implication on plasma cell maturation in vivo and for anti-Ixodes vaccination
MENTEN, Catherine ULg; couvreur, B.; Jolois, Olivier ULg et al

in Vaccine (2011)

Anti-tick vaccination could be an ideal solution to prevent pathogen transmission, but none is currently available against Ixodes ticks. Recently, we showed that adult Ixodes ricinus infestation on mice ... [more ▼]

Anti-tick vaccination could be an ideal solution to prevent pathogen transmission, but none is currently available against Ixodes ticks. Recently, we showed that adult Ixodes ricinus infestation on mice decreases the specific antibody production to BSA injected during infestation. Here, a kinetic study of seric levels of BSA-specific antibodies was performed to evaluate the B memory cell differentiation in Balb/c mice and the capacity of specific B memory cells to respond to BSA during infestation. We concluded that the tick blood meal inhibits or impairs the local differentiation of mature B cells into plasma cells, but does not alter the formation of memory B cell. Accordingly, this mechanism should not be an impediment to anti-Ixodes vaccination. [less ▲]

Detailed reference viewed: 38 (13 ULg)
Full Text
Peer Reviewed
See detailKinetic study of the aspartate/glutamate carrier in intact rat heart mitochondria and comparison with a reconstituted system.
Sluse, Francis ULg; Evens, A.; Dierks, T. et al

in Biochimica et Biophysica Acta-Bioenergetics (1991), 1058

The homologous exchange of external [14C] aspartate/internal aspartate catalyzed by the aspartate/glutamate carrier of rat heart mitochondria was investigated using aspartate-loaded, glutamate-depleted ... [more ▼]

The homologous exchange of external [14C] aspartate/internal aspartate catalyzed by the aspartate/glutamate carrier of rat heart mitochondria was investigated using aspartate-loaded, glutamate-depleted mitochondria. An inhibitor-stop technique was developed for kinetic studies by applying pyridoxal phosphate. Direct initial rate determinations from the linear phase of [14C] aspartate uptake were insufficiently accurate at high external and/or low internal substrate concentrations. Therefore, the full time-course of [14C] aspartate uptake until reaching isotope equilibrium was fitted by a single exponential function and was used to calculate reliable initial steady-state rates. This method was applied in bisubstrate analyses of the antiport reaction for different external and internal aspartate concentrations. The kinetic patterns obtained in double reciprocal plots showed straight lines converging on the abscissa. This result is consistent with a sequential antiport mechanism. It implies the existence of a catalytic ternary complex that is formed by the translocator and substrate molecules bound from both sides of the membrane. The Km values for aspartate were clearly different for the external and the internal sides of the membrane, 216 +/- 23 microM and 2.4 +/- 0.5 mM, respectively. These values indicated a definite transmembrane asymmetry of the carrier. The same asymmetry became evident when investigating the isolated protein from bovine heart mitochondria after reconstitution into liposomes. In this case the Km values for external and internal aspartate were determined to be 123 +/- 11 microM and 2.8 +/- 0.6 mM, respectively. This comparison demonstrates a right-side out orientation of the carrier after insertion into liposomal membranes. The sequential transport mechanism of the aspartate/glutamate carrier, elucidated both in proteoliposomes and in mitochondria, also seems to be a common characteristic of other mitochondrial antiport carriers [less ▲]

Detailed reference viewed: 14 (3 ULg)
Full Text
Peer Reviewed
See detailKinetic study of the transport of adenine nucleotides into rat heart mitochondria (proceedings)
Sluse, Francis ULg; Duyckaerts, Claire ULg; Sluse-Goffart, Claudine et al

in Archives Internationales de Physiologie et de Biochimie (1978), 86

Detailed reference viewed: 6 (1 ULg)
Full Text
Peer Reviewed
See detailKinetic Study of Two Novel Enantiomeric Tricyclic Beta-Lactams Which Efficiently Inactivate Class C Beta-Lactamases
Vilar, M.; Galleni, Moreno ULg; Solmajer, T. et al

in Antimicrobial Agents and Chemotherapy (2001), 45(8), 2215-23

A detailed kinetic study of the interaction between two ethylidene derivatives of tricyclic carbapenems, Lek 156 and Lek 157, and representative beta-lactamases and D-alanyl-D-alanine peptidases (DD ... [more ▼]

A detailed kinetic study of the interaction between two ethylidene derivatives of tricyclic carbapenems, Lek 156 and Lek 157, and representative beta-lactamases and D-alanyl-D-alanine peptidases (DD-peptidases) is presented. Both compounds are very efficient inactivators of the Enterobacter cloacae 908R beta-lactamase, which is usually resistant to inhibition. Preliminary experiments indicate that various extended-spectrum class C beta-lactamases (ACT-1, CMY-1, and MIR-1) are also inactivated. With the E. cloacae 908R enzyme, complete inactivation occurs with a second-order rate constant, k(2)/K', of 2 x 10(4) to 4 x 10(4) M(-1) s(-1), and reactivation is very slow, with a half-life of >1 h. Accordingly, Lek 157 significantly decreases the MIC of ampicillin for E. cloacae P99, a constitutive class C beta-lactamase overproducer. With the other serine beta-lactamases tested, the covalent adducts exhibit a wide range of stabilities, with half-lives ranging from long (>4 h with the TEM-1 class A enzyme), to medium (10 to 20 min with the OXA-10 class D enzyme), to short (0.2 to 0.4 s with the NmcA class A beta-lactamase). By contrast, both carbapenems behave as good substrates of the Bacillus cereus metallo-beta-lactamase (class B). The Streptomyces sp. strain R61 and K15 extracellular DD-peptidases exhibit low levels of sensitivity to both compounds. [less ▲]

Detailed reference viewed: 17 (3 ULg)
Peer Reviewed
See detailKinetic study on a Fe-Co/Al2O3 catalyst for carbon nanotube synthesis by CCVD process
Pirard, Sophie ULg; Douven, Sigrid ULg; Bosuot, Christophe et al

Poster (2006, April)

Detailed reference viewed: 13 (0 ULg)
Full Text
Peer Reviewed
See detailKinetic theory of dust-acoustic waves in plasmas with dust distributions and charge fluctuations
Cattaert, Tom ULg; Verheest, F.

in IEEE Transactions on Plasma Science (2004), 32(2), 537-541

Dust-acoustic waves in dusty plasmas are studied in a kinetic context incorporating dust distributions and charge fluctuations, two of the main features that distinguish dusty or complex from ordinary ... [more ▼]

Dust-acoustic waves in dusty plasmas are studied in a kinetic context incorporating dust distributions and charge fluctuations, two of the main features that distinguish dusty or complex from ordinary plasmas. This is done by deriving a generalized Vlasov equation in an extended phase space. No specific charging model is used so that the results are generic. [less ▲]

Detailed reference viewed: 20 (2 ULg)
Full Text
Peer Reviewed
See detailKinetics and diffusional limitations in nanostructured heterogeneous catalyst with controlled pore texture
Pirard, Sophie ULg; Diverchy, Chantal; Hermans, Sophie et al

in Catalysis Communications (2011), 12

Detailed reference viewed: 34 (5 ULg)
Peer Reviewed
See detailKinetics and diffusional limitations in nanostructured heterogeneous catalyst with controlled pore texture
Pirard, Sophie ULg; Hermans, Sophie; Devillers, Michel et al

Poster (2011, September)

Detailed reference viewed: 7 (0 ULg)
Full Text
Peer Reviewed
See detailKinetics and electron spin resonance study of the radical polymerization of n-butyl acrylate mediated by a nitroxide precursor: C-phenyl-N-tert-butylnitrone
Sciannamea, Valérie; Bernard, Maxime; Catala, Jean-Marie et al

in Journal of Polymer Science. Part A, Polymer Chemistry (2006), 44(21), 6299-6311

The C-phenyl-N-tert-butylnitrone/azobisisobutyronitrile pair is able to impart control to the radical polymerization of n-butyl acrylate as long as a two-step process is implemented, that is, the ... [more ▼]

The C-phenyl-N-tert-butylnitrone/azobisisobutyronitrile pair is able to impart control to the radical polymerization of n-butyl acrylate as long as a two-step process is implemented, that is, the prereaction of the nitrone and the initiator in toluene at 85 degrees C for 4 h followed by the addition and polymerization of n-butyl acrylate at 110 degrees C. The structure of the in situ formed nitroxide has been established from kinetic and electron spin resonance data. The key parameters (the dissociation rate constant, combination rate constant, and equilibrium constant) that govern the process have been evaluated. The equilibrium constant between the dormant and active species is close to 1.6 x 10(-12) mol L-1 at 110 degrees C. The dissociation rate constant and the activation energy for the C-ON bond homolysis are 1.9 x 10(-3) s(-1) and 122 +/- 15 kJ mol(-1), respectively. The rate constant of recombination between the propagating adical and the nitroxide is as high as 1.2 x 10(9) L mol(-1) s(-1). Finally, well-defined poly(n-butyl acrylate)-b-polystyrene block copolymers have been successfully prepared. [less ▲]

Detailed reference viewed: 18 (6 ULg)
Full Text
Peer Reviewed
See detailKinetics and energetics of ligand binding determined by microcalorimetry: Insights into active site mobility in a psychrophilic alpha-amylase
D'Amico, Salvino ULg; Sohier, Jean ULg; Feller, Georges ULg

in Journal of Molecular Biology (2006), 358(5), 1296-1304

A new microcalorimetric method for recording the kinetic parameters k(cat)/K-m and K-i of alpha-amylases using polysaccharides and oligosaccharides as substrates is described. This method is based on the ... [more ▼]

A new microcalorimetric method for recording the kinetic parameters k(cat)/K-m and K-i of alpha-amylases using polysaccharides and oligosaccharides as substrates is described. This method is based on the heat released by glycosidic bond hydrolysis. The method has been developed to study the active site properties of the cold-active alpha-amylase produced by an Antarctic psychrophilic bacterium in comparison with its closest structural homolog from pig pancreas. It is shown that the psychrophilic a-amylase is more active on large macromolecular substrates and that the higher rate constants k(cat) are gained at the expense of a lower affinity for the substrate. The active site is able to accommodate larger inhibitory complexes, resulting in a mixed-type inhibition of starch hydrolysis by maltose. A method for recording the binding enthalpies by isothermal titration calorimetry in a low-affinity system has been developed, allowing analysis of the energetics of weak ligand binding using the allosteric activator chloride. It is shown that the low affinity of the psychrophilic a-amylase for chloride is entropically driven. The high enthalpic and entropic contributions of activator binding suggest large structural fluctuations between the free and the bound states of the cold-active enzyme. The kinetic and thermodynamic data for the psychrophilic a-amylase indicate that the strictly conserved side-chains involved in substrate binding and catalysis possess an improved mobility, responsible for activity in the cold, and resulting from the disappearance of stabilizing interactions far from the active site. (c) 2006 Elsevier Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 19 (5 ULg)
Full Text
Peer Reviewed
See detailKinetics and mechanism of the exchange reactions catalysed by the oxoglutarate translocator of rat-heart mitochondria.
Sluse, Francis ULg; Goffard, George; lièbecq, Claude

in European Journal of Biochemistry (1973), 32

Detailed reference viewed: 7 (2 ULg)
Full Text
Peer Reviewed
See detailKinetics and mechanism of the exchange reactions catalysed by the oxoglutarate translocator of rat-heart mitochondria.
Sluse, Francis ULg; Lièbecq, Claude

in Biochimie (1973), 55(6), 747-754

Detailed reference viewed: 20 (7 ULg)
Full Text
Peer Reviewed
See detailKinetics and Thermodynamics of Glucose Isomerase Crystallization
Sleutel, Mike; Willaert, Ronnie; Gillespie, Christopher et al

in Crystal Growth & Design (2009), 9

A quantitative study using laser confocal microscopy combined with differential interference microscopy on the kinetics and thermodynamics of the crystallization of glucose isomerase is presented ... [more ▼]

A quantitative study using laser confocal microscopy combined with differential interference microscopy on the kinetics and thermodynamics of the crystallization of glucose isomerase is presented. Fundamental crystallization parameters are determined from the kinetics of step advancement and rates of two-dimensional (2D) nucleation. The ruling mass transfer pathway and accompanying activation barriers are discussed. In brief, the solubility exhibits normal temperature dependence and the crystallization enthalpy is the thermodynamic driving force. The diminishing entropic cost for higher PEG concentrations is attributed to water structuring and a decrease in water activity. The prominent step generation mechanism is homogeneous 2D nucleation for high supersaturations. At low driving forces 2D nucleation occurs on anomalously hyperactive sites and the step edge free energies for homogeneous and heterogeneous nucleation are determined. The number of nucleation centers for both mechanisms are estimated and from the density of nucleation centers we obtain for the activation barrier of adsorption ∼3.8 kJ mol-1. No step-step interaction is observed for interstep distances >70 nm. Theoretical fits of step velocity data suggest surface diffusion makes a non-negligible contribution to surface kinetics. From the temperature dependence of the step kinetic coefficient the activation barrier for crystallization was determined to be <22.4 kJ mol-1. [less ▲]

Detailed reference viewed: 92 (12 ULg)
Full Text
Peer Reviewed
See detailKinetics modelling of convective heat drying of wastewater treatment sludge
Léonard, Angélique ULg; Salmon, Thierry ULg; Janssens et al

in Flamand, G. (Ed.) Récents progrés en génie des procédés vol.13 n.68 : separations. ECCE 2 conference Montpellier 5/7.10.99 (1999, October)

Detailed reference viewed: 26 (4 ULg)
Full Text
Peer Reviewed
See detailKinetics of 2-oxoglutarate transport in heart mitochondria
Sluse, Francis ULg; Ranson, Monique; Lièbecq, C.

in Journal de Physiologie (1971), 63

Detailed reference viewed: 5 (1 ULg)
Full Text
See detailThe kinetics of a microbial population
Gillet, Marie-Claire ULg; Remacle, Jean

in Loutit, M. W.; Miles, J. A. R. (Eds.) Microbila Ecology (1978)

The study is an attempt to show the relationship between environmental variables such as pH and temperature and the control of some microbial growth characteristics. Two models were used in order to ... [more ▼]

The study is an attempt to show the relationship between environmental variables such as pH and temperature and the control of some microbial growth characteristics. Two models were used in order to calculate the death rate in continuous cultures. [less ▲]

Detailed reference viewed: 9 (1 ULg)
Peer Reviewed
See detailKinetics of a specific antibody response after successful treatment in naturally Psoroptes ovis infested cattle
Lonneux, J. F.; Bossaert, K.; Leclipteux, T. et al

Conference (1995)

Detailed reference viewed: 3 (0 ULg)
Full Text
Peer Reviewed
See detailKinetics of C-Reactive Protein (CRP) following maintenance infliximab treatment in Crohn's disease identifies profiles of patients with better outcome
Jürgens, M.; Mahachie John, Jestinah ULg; Cleynen, I. et al

in Gastroenterology (2010), 138(5 (Suppl I)), -686

Detailed reference viewed: 16 (8 ULg)