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See detailOxygen consumption of equine articular chondrocytes: Influence of applied oxygen tension and glucose concentration during culture.
Schneider, Nicole ULg; Mouithys-Mickalad, Ange ULg; Lejeune, Jean-Philippe ULg et al

in Cell Biology International (2007), 31

We investigated the oxygen (O2) uptake of equine articular chondrocytes to assess their reactions to anoxia/re-oxygenation. They were cultured under 5% or 21% gas phase O2 and at glucose concentrations of ... [more ▼]

We investigated the oxygen (O2) uptake of equine articular chondrocytes to assess their reactions to anoxia/re-oxygenation. They were cultured under 5% or 21% gas phase O2 and at glucose concentrations of 0, 1.0 or 4.5 g/L in the culture medium (n = 3). Afterwards, the O2 consumption rate of the chondrocytes was monitored (oxymetry) before and after an anoxia period of 25 min. The glucose consumption and lactate release were measured at the end of the re-oxygenation period. The chondrocytes showed a minimal O2 consumption rate, which was hardly changed by anoxia. Independently from the O2 tension, glucose uptake by the cells was about 30% of the available culture medium glucose, thus higher for cells at 4.5 g/L glucose (n = 3). Lactate release was also independent from O2 tension, but lower for cells at 4.5 g/L glucose (n = 3). Our observations indicated that O2 consumption by equine chondrocytes was very low despite a functional mitochondrial respiratory chain, and nearly insensitive to anoxia/re-oxygenation. But the chondrocytes metabolism was modified by an excess of O2 and glucose. [less ▲]

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See detailOxygen Fluxes, Redox Processes and the Suboxic Zone in the Black Sea
Konovalov, S.; Murray, J.; Luther, G. et al

in International conference. Oceanography of the eastern Mediterranean and Black Sea. Similarities and differences of two interconnected basins, Zappeion international conference Centre (2002)

We use the results of numerical modeling, calibrated and verified againsthistorical data from 1960 to 1995 and the most recent data from the 2001 Knorr cruise,to investigate the redox budget of the Black ... [more ▼]

We use the results of numerical modeling, calibrated and verified againsthistorical data from 1960 to 1995 and the most recent data from the 2001 Knorr cruise,to investigate the redox budget of the Black Sea water column and the main processesgoverning this budget. The results can be summarized as follows: (1) Injection of Mediterranean water, through the Bosporus, into the Black Sea results in intrusions of oxygen in the suboxic and anoxic layers; (2) The intensity of ventilation of the CIL andthe export production of organic matter are the primary control on interannualvariations in the thickness of the suboxic zone; (3) The lateral influx of oxygen resultsin oxidation of sulfide inside the anoxic zone. Almost 70% of the total vertical flux of sulfide is oxidized by this oxygen, mainly through redox Mn(II) – Mn(III,IV) cycling;(4) Nitrate seams to be responsible for oxidation of dissolved Mn(II) in the suboxiczone and Mn(III,IV) hydroxides, the end-products of this oxidation, sink and oxidizeabout 25% of the total flux of sulfide; (5) The vertical flux of oxygen at the onset of sulfide may account for consumption of a small fraction (less than 1%) of the total fluxof sulfide; (6) The lateral flux of oxygen also appears to be the main reason for the presence of the suboxic layer. [less ▲]

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See detailOxygen influence on the ß-oxidative metabolism of methyl ricinoleate for lactones production by the yeast Yarrowia lipolytica
Aguedo, Mario ULg

in Proceedings of the 2nd Mercosur Congress on Chemical Engineering – ENPROMER and 4th Mercosur Congress on Process Systems Engineering (2005, August)

The yeast Yarrowia lipolytica is able to carry out the peroxisomal b-oxidative catabolism of methyl ricinoleate, a process leading notably to the production of g-decalactone, a high-value aroma compound ... [more ▼]

The yeast Yarrowia lipolytica is able to carry out the peroxisomal b-oxidative catabolism of methyl ricinoleate, a process leading notably to the production of g-decalactone, a high-value aroma compound. In fact, this metabolic pathway gives rise to different C10 lactones and their accumulations report the efficiency of the peroxisomal beta-oxidation enzymes. gamma-Decalactone or 3-hydroxydecan-4-olide accumulate when acyl-CoA oxidase or 3-hydroxyacyl-CoA dehydrogenase, respectively, control the flux within the pathway. We investigated the accumulation of C10 lactones in various aeration conditions. An important accumulation of 3-hydroxydecan-4-olide was observed when increasing the aeration up to a certain point, above it its concentration was lowered, which indicates a stimulation of the activity of 3-hydroxyacyl-CoA dehydrogenase. Cultures under high-pressure were performed in order to increase the oxygen in the medium by an alternative mean. Y. lipolytica growth in glucose medium was accelerated at 0.5 MPa of total air pressure. A decrease in g-decalactone production was observed with the increase in pressure. Curiously, applying a pressure of 0.5 MPa during growth and then during biotransformation resulted in high decenolides concentrations. [less ▲]

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See detailOxygen mass transfer in a biphasic medium: Influence on the biotransformation of methyl ricinoleate into γ-decalactone by the yeast Yarrowia lipolytica
Gomes, N.; Aguedo, Mario ULg; Teixeira, J. et al

in Biochemical Engineering Journal (2007), 35(3), 380-386

In this work, an empirical correlation is proposed to describe kLa as a function of operating conditions (agitation and aeration rates) and of oil and surfactant volumetric fractions in a ... [more ▼]

In this work, an empirical correlation is proposed to describe kLa as a function of operating conditions (agitation and aeration rates) and of oil and surfactant volumetric fractions in a biotransformation medium, an oil-in-water dispersion. An interaction effect between the oil and the surfactant effects was found, since oil presence increased kLa in the absence of the surfactant but had an opposite effect when Tween 80 was available in the medium. The biotransformation of methyl ricinoleate (MR) into γ-decalactone (an aroma compound of industrial interest), by the yeast Yarrowia lipolytica, was carried out at different conditions of operation, to evaluate the influence of kLa on the production of the aroma. It was demonstrated that kLa had an influence on the aroma production; however, for the low hydrophobic substrate concentration used (1.08% v/v) and cellular density of 2.0 × 107 cells mL-1, a minimal kLa value of 70 h-1 was necessary to attain the maximal aroma production. © 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailOxygen nightglow emissions of Venus: Vertical distribution and collisional quenching
Gérard, Jean-Claude ULg; Soret, Lauriane ULg; Migliorini, Alessandra et al

in Icarus (2013)

We compare the altitude of three O2 night airglow emissions observed at the limb of Venus by the VIRTIS spectral imager with the values predicted by a model accounting for the different radiative ... [more ▼]

We compare the altitude of three O2 night airglow emissions observed at the limb of Venus by the VIRTIS spectral imager with the values predicted by a model accounting for the different radiative lifetimes and collisional deactivation of the upper O2 states. The O and CO2 density profiles are based on remote sensing observations from the Venus Express spacecraft. Effective production efficiencies of the involved O2 metastable states and quenching coefficients by oxygen and carbon dioxide are adjusted to provide the best match with the measured emission limb profiles. We find values in general good agreement with earlier studies for the c1Σ-u state which gives rise to the Herzberg II bands. In particular, we confirm the low net yield of the c state production and the importance of its deactivation by CO2, for which we derive a quenching coefficient of 3x10-16 cm-3 s-1. The ∼4.5 km higher altitude of the Chamberlain band emission also recently detected by VIRTIS and the ratio of the Herzberg II/Chamberlain bands observed with Venera are well reproduced. To reach agreement, we use a 12% yield for the A’3Δu production following O atom association and quenching coefficients by O and CO2 of 1.3x10-11 cm-3 s-1 and 4.5x10-13 cm-3 s-1 respectively. We conclude that the different peak altitudes of the IR Atmospheric, Herzberg II and the Chamberlain bands reflect the relative importance of radiative relaxation and collisional quenching by O and CO2. [less ▲]

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See detailThe oxygen nightglow emissions of Venus: vertical distribution and role of collisional quenching
Gérard, Jean-Claude ULg; Soret, Lauriane ULg; Migliorini, Alessandra et al

Conference (2012, April)

The oxygen nightglow emissions of Venus: vertical distribution and role of collisional quenching J.-C. Gérard (1), L. Soret (1), A. Migliorini (2), G. Piccioni (2), and P. Drossart (3) (1) LPAP ... [more ▼]

The oxygen nightglow emissions of Venus: vertical distribution and role of collisional quenching J.-C. Gérard (1), L. Soret (1), A. Migliorini (2), G. Piccioni (2), and P. Drossart (3) (1) LPAP - Université de Liège - Belgium (jc.gerard@ulg.ac.be, 0032 4 366 9711), (2) INAF - Rome, Italy, (3) LESIA, Observatoire de Paris - Meudon, France Three-body recombination of atomic oxygen produces O2 molecules excited in different electronic states such as a 1∆g, b 1 􏰀+g , A 3 􏰀+u , c 1 􏰀uand A’ 3∆u, each with a specific quantum efficiency. When they radiate, optical transitions are observed in a wide range of wavelengths extending from the ultraviolet to the near infrared. In planetary atmospheres, spontaneous radiative deexcitation compete with collisional quenching with ambient molecules and atoms. As a consequence, the corresponding airglow emission profiles may significantly differ from each other in brightness and altitude of the emitting layer. We model the volume emission rates and limb profiles of the O2 Atmospheric Infrared (a 1∆-X 3 􏰀), Herzberg I (A 3 􏰀-X 3 􏰀), Herzberg II (c 1 􏰀-X 3 􏰀), Chamberlain (A’ 3∆-a 1∆) bands expected on the Venus night side. The quenching rates are taken from laboratory and observational planetary data and we apply two different methods to determine the oxygen and CO2 density profiles. One is based on recent analysis of data collected by instruments on board the Venus Express mission. The second one uses a one-dimensional chemical-diffusive model where the free parameters are the strength of turbulent transport and the downward flux of O atoms. Both approaches indicate that the calculated intensities of each transition range over several orders of magnitude and that differences are expected in the altitude of the maximum emission. These predictions will be compared with VIRTIS/Venus Express limb observations, which make it possible to derive the vertical distribution of the O2 emissions in the visible and infrared. These measurements suggest that no difference is observed between the altitude of the peak of the IR Atmospheric and Herzberg II bands. Conclusions will be drawn about the validity of the current set of quenching coefficients used in the model. [less ▲]

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See detailOxygen Nightglow Investigation in the Visible Spectral Range, Using VIRTIS/Venus Express Data
Migliorini, A.; Piccioni, G.; Drossart, P. et al

Conference (2011, March 01)

Oxygen emissions in the visible spectral range, detected with VIRTIS on board Venus Express, in the upper atmosphere of Venus.

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See detailOxygen therapy in intensive care patients: a vital poison?
Deby, Ginette ULg; Deby, C.; Lamy, Maurice ULg

in Vincent, Jean-Louis (Ed.) Yearbook of intensive care and emergency medicine (1999)

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See detailOxygen transfert during Bacillus subtilis fermentation. Influence of lipopeptide production and an oxygen vector.
Hbid, Ch; Jacques, Ph.; Meurice, E. et al

in Archives Internationales de Physiologie et de Biochimie (1995), 103(B44),

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See detailOxygen transfert during Bacillus subtilis fermentation. Influence of lipopeptide production, and an oxygen vector
Hbid, C.; Jacques, P.; Meurice, E. et al

in Archives of Physiology & Biochemistry (1995), 103

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See detailOxygen transfert during Bacillus subtilis fermentation. Influence of lipopeptide production, and an oxygen vector.
Hbid, Ch.; Jacques, Ph.; Meurice, E. et al

Poster (1995, May)

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See detailOxygen Transport Chain in Double-Muscled Blue Belgian Cattle
Lekeux, Pierre ULg; Amory, Hélène ULg; Desmecht, Daniel ULg et al

in British Veterinary Journal (The) (1994), 150(5, Sep-Oct), 463-471

The physiological peculiarities of the oxygen transport chain in double-muscled Blue Belgian cattle are described. The investigations performed at several levels of the oxygen transport chain suggest that ... [more ▼]

The physiological peculiarities of the oxygen transport chain in double-muscled Blue Belgian cattle are described. The investigations performed at several levels of the oxygen transport chain suggest that the increased susceptibility of these cattle to stress, resulting mainly in respiratory diseases, is due to an insufficient functional reserve capacity mainly involving the pulmonary and cardiovascular systems. The resulting lack of 'functional hardiness' of the oxygen transport chain is seen in those double-muscled cattle which do not react in an appropriate or predictable way when submitted to a hostile environment. [less ▲]

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See detailOxygen Transport Properties of Blood in Two Different Bovine Breeds
Gustin, Pascal ULg; Clerbaux, T.; Willems, Evelyne ULg et al

in Comparative Biochemistry and Physiology. A : Comparative Physiology (1988), 89(4), 553-558

1. The whole oxygen dissociation curve of oxyhemoglobin has been determined in double-muscled cattle of the Belgian White Blue breed and in Friesian cattle of different body weight. 2. In calves, P50 ... [more ▼]

1. The whole oxygen dissociation curve of oxyhemoglobin has been determined in double-muscled cattle of the Belgian White Blue breed and in Friesian cattle of different body weight. 2. In calves, P50 values are low and DPG level is high (4-20 mumol/g Hb). 3. P50 values of 25 +/- 1.4 mm Hg (mean +/- SD) and a level of DPG less than 1.5 mumol/g Hb have been found in animals weighing more than 80 kg. 4. Effects of temperature and pH on the oxygen dissociation curve have been measured at all levels of saturation. The temperature coefficient (dlog P50/dT) and the Bohr effect expressed as dlog P50/dpH were 0.017 and -0.40, respectively. 5. Hematocrit, hemoglobin concentrations and oxygen capacity of hemoglobin have been measured. 6. No difference between both breeds has been observed. 7. These data can be used to correct measured values of oxygen tension for temperature and pH and to measure oxygen content of blood in cattle. [less ▲]

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See detailOxygen, a tool for assessing ocean tracer transport models
Mouchet, Anne ULg; Campin, Jean-Michel

Poster (2011, May)

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See detailOxygen, a tool for assessing ocean tracer transport models
Mouchet, Anne ULg

Poster (2008, April)

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See detailOxygen: a critical component of critically sized defects
Carlier, Aurélie ULg; Van Gastel, Nick; Geris, Liesbet ULg et al

Poster (2013, December 19)

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See detailOxygène pour les algies vasculaires de la face
Belche, Jean-Luc ULg

in Minerva (2010), 9(9), 98-99

Analyse de Cohen AS, Burns B, Goadsby P. High-flow oxygen for treatment of cluster headache. A randomized trial. JAMA 2009;302:2451-7.Quelle est l’efficacité de l’inhalation d’oxygène à haut débit dans le ... [more ▼]

Analyse de Cohen AS, Burns B, Goadsby P. High-flow oxygen for treatment of cluster headache. A randomized trial. JAMA 2009;302:2451-7.Quelle est l’efficacité de l’inhalation d’oxygène à haut débit dans le traitement aigu des algies vasculaires de la face ? [less ▲]

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See detailOxygénothérapie au long cours a domicile (OLD) chez le patient BPCO
NGUYEN DANG, M.; Royaux, Philippe ULg; Bury, Thierry ULg

in Revue Médicale de Liège (2006), 61(5-6, May-Jun), 401-4

Ambulatory oxygen therapy has become standard care for chronic hypoxemia. Indeed, two large multicenter trials have clearly shown the survival benefit from long-term home oxygen therapy. We present the ... [more ▼]

Ambulatory oxygen therapy has become standard care for chronic hypoxemia. Indeed, two large multicenter trials have clearly shown the survival benefit from long-term home oxygen therapy. We present the rationale for using ambulatory oxygen therapy and the different home oxygen systems. [less ▲]

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