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See detailThe effect of spaceflight and microgravity on the human brain
Van Ombergen, Angelique; Demertzi, Athina ULiege; Tomilovskaya et al

in Journal of Neurology (in press)

Microgravity, confinement, isolation, and immobilization are just some of the features astronauts have to cope with during space missions. Consequently, long-duration space travel can have detrimental ... [more ▼]

Microgravity, confinement, isolation, and immobilization are just some of the features astronauts have to cope with during space missions. Consequently, long-duration space travel can have detrimental effects on human physiology. Although research has focused on the cardiovascular and musculoskeletal system in particular, the exact impact of spaceflight on the human central nervous system remains to be determined. Previous studies have reported psychological problems, cephalic fluid shifts, neurovestibular problems, and cognitive alterations, but there is paucity in the knowledge of the underlying neural substrates. Previous space analogue studies and preliminary spaceflight studies have shown an involvement of the cerebellum, cortical sensorimotor, and somatosensory areas and the vestibular pathways. Extending this knowledge is crucial, especially in view of long-duration interplanetary missions (e.g., Mars missions) and space tourism. In addition, the acquired insight could be relevant for vestibular patients, patients with neurodegenerative disorders, as well as the elderly population, coping with multisensory deficit syndromes, immobilization, and inactivity. [less ▲]

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See detailThe effect of spatial micro-CT image resolution and surface complexity on the morphological 3D analysis of open porous structures
Pyka, G.; Kerckhofs, Greet ULiege; Van Bael, S. et al

in Materials Characterization (2014), 87

Detailed reference viewed: 31 (5 ULiège)
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See detailEffect of Spinal Cord Stimulation on Regional Myocardial Perfusion Assessed by Positron Emission Tomography
de Landsheere, Christian ULiege; Mannheimer, C.; Habets, A. et al

in American Journal of Cardiology (1992), 69(14), 1143-9

Spinal cord stimulation (SCS) can relieve symptoms in patients with severe angina pectoris refractory to conventional medical or surgical therapy. This symptomatic improvement may result from decreased ... [more ▼]

Spinal cord stimulation (SCS) can relieve symptoms in patients with severe angina pectoris refractory to conventional medical or surgical therapy. This symptomatic improvement may result from decreased myocardial ischemia. To test this hypothesis, positron emission tomography (PET) and potassium-38 as a flow tracer were used in 8 patients for the quantitative evaluation of regional myocardial perfusion at rest and after exercise, before and during SCS. Potassium uptake was evaluated as myocardial clearance (flow times net extraction) in ml/min/100 g. Tomographic segments were categorized as nonaffected and affected on the basis of the absence or presence of arterial stenosis on coronary angiography and on the basis of thallium scintigraphic data. In nonaffected segments, before SCS, regional myocardial clearance significantly increased from rest (28 +/- 4) to exercise (47 +/- 13 clearance units; p less than 0.004). A similar increase occurred after SCS. In affected segments, before SCS, regional myocardial clearance barely increased (p = 0.065) from rest (26 +/- 6) to exercise (33 less than or equal to 12). In comparison, after SCS, the resting regional myocardial clearance was slightly elevated (29 +/- 8) reflecting an increased double product, but did not increase (p = 0.192) with exercise (34 +/- 12). However, the magnitude and duration of ST-segment depression decreased during treatment with SCS. Anginal pain occurred in all patients during control exercise, but was attenuated in all but one with SCS. These results indicate that SCS improves exercise-induced angina and electrocardiographic signs of ischemia but this influence does not appear to be mediated by changes in regional myocardial perfusion. [less ▲]

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See detailThe effect of spontaneous self-reference on memory: a replication
Brédart, Serge ULiege; François, Sarah ULiege; Guimond, Serge

in Année Psychologique (L') (2013), 113(2), 161-167

Detailed reference viewed: 89 (27 ULiège)
See detailEffect of statin on liposome and cell membranes fluidity. An ESR spin probe study.
Ngendakamuna; Bahri, Mohamed Ali ULiege; Hoebeke, Maryse ULiege

Poster (2008, May 16)

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See detailEffect of steam explosion pre-treatment on enzymatic saccharification of lignocellulosic material
Meyer, Laurence ULiege; Jacquet, Nicolas ULiege; Vanderghem, Caroline ULiege et al

Poster (2011, September 08)

Taking into account the sharp rise in prices and the depletion of resources of petroleum, an alternative to fossil resources is needed. A probable alternative is the use of lignocellulosic raw material to ... [more ▼]

Taking into account the sharp rise in prices and the depletion of resources of petroleum, an alternative to fossil resources is needed. A probable alternative is the use of lignocellulosic raw material to produce biofuels. The “first generation” biofuels are highly controversial because of the use of food plant material. The aim of the “second generation” biofuels is to take lignocellulosic non-food plant material as raw material. Lignocellulosic biomass has a very complex structure made of linkages between lignins, cellulose and hemicelluloses. The saccharification of these lignocellulosic materials requires the fractionation of its constituents. Research has lead to many lignocellulosic biomass fractionation pre-treatments. This study particularly focuses on the steam explosion pretreatment followed by an enzymatic saccharification. Steam explosion is a thermomechanical process which allows the breakdown of the lignocellulosic material structure by the combined action of steam heating, hydrolysis induced by the organic acids formed during the process and shear stress resulting from the pressure rough drop. This treatment leads to modification of the physical parameters such as water retention capacity, cristallinity rate of the cellulosic fraction, hydrolysis of the hemicellulosic fraction and rearrangement in the lignin structure. Such modifications are supposed to make cellulose enzymatic hydrolysis from complex lignocellulosic material easier. In order to verify this hypothesis, different lignocellulosic raw materials have been pre-treated by steam explosion. These materials were sugar beet pulp, corn straw and miscanthus. In order to check the effect of steam explosion pre-treatment on cellulose, a microcrystalline cellulose was also treated. Steam explosion was performed at a vapor pressure of 18 bars and with a retention time of 2 minutes. The steam exploded lignocellulosic materials and the untreated one were submitted to a hydrolysis with a mixture of enzymes composed of cellulases and cellobiase activities during 24 hours. The quantification of glucose in the hydrolysates at different times was performed by HPAEC-PAD. Rate of cellulose converted into glucose were better with steam exploded raw material showing that steam explosion allows improvement of lignocellulosic material for enzymatic saccharification. [less ▲]

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See detailEffect of steam explosion treatment on chemical composition and characteristic of organosolv fescue lignin
Maniet, Guillaume ULiege; Schmetz, Quentin ULiege; Jacquet, Nicolas ULiege et al

in Industrial Crops and Products (2017), 99

Tall fescue, a grass currently grown as forage, presents a good potential as a feedstock in the developmentof biorefining. In this study, combination of steam explosion and an acetic/formic acid ... [more ▼]

Tall fescue, a grass currently grown as forage, presents a good potential as a feedstock in the developmentof biorefining. In this study, combination of steam explosion and an acetic/formic acid “organosolv”pretreatments are applied on raw fescue to optimize lignin extraction yields and obtain specific products.In a first step, fescue is pretreated by steam explosion under severity factors from 1.4 to 4.2. Thesetreatments allow hemicelluloses solubilization and open the lignocellulosic structure. Steam explodedsolid residues are then treated with an acetic acid (50%)/formic acid (30%)/water (20%) mixture. Extractedlignins are precipitated and characterized by size exclusion chromatography (SEC),31P NMR and HSQCNMR. Results show that acetic and formic acids extracted lignins present G, H and S units with ferulate andp-coumarate. Lignin typical linkages identified are of -O-4 and spirodienone substructures. Combinationof steam explosion and acetic and formic acid pretreatments increases extraction yields from 30% to100%. Moreover, an increase of the steam explosion treatment intensity induces chemical modificationsin lignin structure such -O-4 and spirodienone substructure degradations, increase of free COOH andphenolic OH bonds, decrease of aliphatic OH ferulate and p-coumarate bonds and changes in G/H/S unitsproportions. Steam explosion intensity affects also lignin molecular weights. [less ▲]

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See detailEffect of stellar rotation on oscillation frequencies
Ouazzani, R. M.; Goupil, M. J.; Dupret, Marc-Antoine ULiege et al

in Astrophysics & Space Science (2010), 328

We investigate whether the rotational splittings of β Cephei stars can give some clue about the existence of a differential rotation in latitude, and if they are contaminated by the cubic order effects ... [more ▼]

We investigate whether the rotational splittings of β Cephei stars can give some clue about the existence of a differential rotation in latitude, and if they are contaminated by the cubic order effects of rotation on oscillation frequencies. We also study some properties of splitting asymmetries and axisymmetric mode frequencies which provide seismic constrains on the distortion of the star. We find that only non-perturbative methods are able to reproduce those two seismic characteristics within 0.01% error bars for stars when they rotate faster than 3.3% Ω [SUB] k [/SUB]. If error bars of 1% are acceptable, the threshold of validity of perturbative methods is extended to 10% Ω [SUB] k [/SUB]. [less ▲]

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See detailEffect of stocking density on the dynamics of cannibalism in sibling larvae of Perca fluviatilis under controlled conditions
Baras, E.; Kestemont, P.; Mélard, Charles ULiege

in Aquaculture (2003), 219(1-4), 241-255

The effect of stocking density (10, 31.6 and 100 larvae 1(-1); three replicates per treatment) on the day-by-day dynamics of survival, growth and cannibalism was examined in sibling perch larvae reared ... [more ▼]

The effect of stocking density (10, 31.6 and 100 larvae 1(-1); three replicates per treatment) on the day-by-day dynamics of survival, growth and cannibalism was examined in sibling perch larvae reared from eyed-egg stage in 100-1 cages (16L:8D, 20.0 +/- 0.5 degreesC, O-2 greater than or equal to 6.0 mg 1(-1); feeding in excess with live Artemia nauplii during the photophase) during the first 3 weeks of exogenous feeding. Larvae unable to achieve the transition to exogenous feeding died in between 7 and I I days post-hatch. Later, mortality from causes other than cannibalism never exceeded 1% day(-1). Cannibalism did not start before days 10 - 11 and first consisted in the incomplete ingestion of prey attacked tail first, exclusively. This type of cannibalism never caused losses higher than 2.0% of the initial stock, and ceased after days 16-18. From days 12-14 onwards, differential growth was apparent, and cannibals turned to complete cannibalism of small prey ingested head first, which caused greater losses (28-53% of the stock). Increasing the stocking density did not compromise growth and decreased the overall impact of cannibalism through several complementary mechanisms: (i) a postponed emergence of cannibalism, (ii) a lower proportion of cannibals in the population, and (iii) probably a lower rate of cannibalism per capita as predation was complicated and less directed at high stocking density. (C) 2003 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailEffect of storage and cooking on the fatty acid profile of omega-3 enriched eggs and pork meat marketed in Belgium
Douny, Caroline ULiege; El Khoury, Rawad; Delmelle, Julien et al

in Food Science & Nutrition (2015), 3(2), 140-152

Detailed reference viewed: 92 (39 ULiège)
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See detailEffect of strain rate on the forming behaviour of sheet metals
Verleysen, Patricia; Peirs, Jan; Van Slycken, Joost et al

in Journal of Materials Processing Technology (2011), 211

The strain rate dependence of plastic yield and failure properties displayed by most metals affects energies, forces and forming limits involved in high speed forming processes. This paper investigates ... [more ▼]

The strain rate dependence of plastic yield and failure properties displayed by most metals affects energies, forces and forming limits involved in high speed forming processes. This paper investigates the influence of the strain rate on the forming properties of one laboratory made and three commercial steel grades: a CMnAl TRIP steel, the ferritic structural steel S235JR, the drawing steel DC04 and the ferritic stainless steel AISI 409. First, split Hopkinson tensile bar (SHTB) experiments are carried out to assess the influence of the strain rate on the materials’ stress–strain curves. Subsequently, the obtained SHTB results, together with static tensile test results, are used to model the constitutive behaviour of the investigated steels using the phenomenological Johnson–Cook (JC) model and the Voce model, thus allowing dynamic modelling of forming processes. Finally, forming limit diagrams (FLDs) are calculated using the Marciniak–Kuczynski method. The results clearly show that the effect of the strain rate on forces and energies involved in a forming process, and the forming limits is non-negligible and strongly material dependent. [less ▲]

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See detailEffect of strenuous exercise and ex-vivo TLR3 and TLR4 stimulation on inflammatory gene expression in equine pulmonary leukocytes
Mignot, Clémence; Pirottin, Dimitri ULiege; de Moffarts, Brieuc et al

in Veterinary Immunology and Immunopathology (2012), 147

The effects of strenuous exercise and ex-vivo stimulation of TLR3 and TLR4 pathways on the expression of six inflammatory genes in equine pulmonary leukocytes were investigated. The genes tested were ... [more ▼]

The effects of strenuous exercise and ex-vivo stimulation of TLR3 and TLR4 pathways on the expression of six inflammatory genes in equine pulmonary leukocytes were investigated. The genes tested were interferon-beta (IFN-β), interleukin-1-beta (IL-1β), interleukin-6 (IL-6), interferon gamma-induced protein 10 (IP-10), chemokine (c-c motif) ligand 5 (RANTES) and tumor necrosis factor-alpha (TNFα). We hypothesized that strenuous exercise would modulate basal gene expression on one hand and modulate the response to bacterial lipopolysaccharide (LPS) and to Polyinosinic:polycytidylic acid (Poly IC) on the other hand. Eight young Thoroughbred mares were selected for the experiment. Bronchoalveolar lavages were performed on horses 48h before and 24h after the completion of treadmill exercise until fatigue. Differential counts were performed on the bronchoalveolar lavage cells. Real-time PCR was used to quantify cytokine expression in pulmonary leukocytes. Target gene expression was normalized to the expression of three housekeeping genes(HKG). There were no significant differences in the mRNA expression of the six cytokines between pre-exercise and post-exercise cells. LPS and Poly IC induced respectively significant increases of TNF-α, IFN-β, IL-6, IL-1β, and TNF-α, IFN-β, IP-10 and RANTES, both before and after exercise. However, exercise induced a significant decrease of the genes response to LPS and Poly IC. These findings may suggest that strenuous treadmill exercise exerts a deleterious effect on part of the pulmonary immune response in horses 24h following an intense physical activity. [less ▲]

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See detailEffect of stress path on the miniaturizatio size effect for nickel polycrystals
Keller, Clement; Hug, Eric; Duchene, Laurent ULiege et al

Conference (2015, January 04)

The mechanical behavior of mettalic materials deeply depends on the size of samples. For specimen dimensions de creasing from a few millimeters to a few micrometers, the general observed trend is a ... [more ▼]

The mechanical behavior of mettalic materials deeply depends on the size of samples. For specimen dimensions de creasing from a few millimeters to a few micrometers, the general observed trend is a softening of the mechanical behavior in tension which affects the stress level and the strain hardening. This effect is triggered by the derease of the number of grains across the thickness ( also called thickness"t" over grain size "d" ratio). The objective of this work is to provide new experimental results in order to analyse the miniaturization size effects for various stress paths without strain gradients across the thickness of the samples. To this aim, experimental tensil tests, large tensile tests and shear tests have been performed on Ni sheets ( 0.5mm) with various grain sizes ensuring different t/d ratios. Results show that the miniaturization softening is affected by triaxiality, the larger is this parameter, the lower is the mechanicval softening. These features seem to be linked to surface effects which are larger for low triaxiality stress paths. Attempts of numerical simulations using strain gradient crystal plasticity model are also performed to confirm the role played by surface effects. [less ▲]

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See detailEffect of stress path on the miniaturization size effect for nickel polycrystals
Keller, Clement; Hug, Eric; Habraken, Anne ULiege et al

in International Journal of Plasticity (2015), 64

The mechanical behavior of metallic materials deeply depends on the size of samples. For specimen dimensions decreasing from a few millimeters to a few micrometers, the general observed trend is a ... [more ▼]

The mechanical behavior of metallic materials deeply depends on the size of samples. For specimen dimensions decreasing from a few millimeters to a few micrometers, the general observed trend is a softening of the mechanical behavior in tension which affects the stress level and the strain hardening. The objective of this work is to provide new experimental results in order to analyze the miniaturization size effects for various stress paths without strain gradients across the thickness of the samples. To this aim, experimental tensile tests, large tensile tests and shear tests have been performed on Ni sheets with various grain sizes. Results show that the miniaturization softening is affected by triaxiality, the larger is this parameter, the lower is the mechanical softening. These features seem to be linked to surface effects which are larger for low triaxiality stress paths. From an industrial point of view, it is hence possible to improve the forming of microparts using suitable stress paths. [less ▲]

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See detailEffect of Strontium Incorporation on the p-Type Conductivity of Cu2O Thin Films Deposited by Metal–Organic Chemical Vapor Deposition
Brochen, Stéphane; Laurent, Bergerot; Wilfried, Favre et al

in Journal of Physical Chemistry C (2016)

Detailed reference viewed: 11 (5 ULiège)
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See detailEffect of strontium ranelate on serum osteoprotegerin in women with postmenopausal osteoporosis treated over three years
Collette, Julien ULiege; Bruyère, Olivier ULiege; Vanoverberghe, Marie ULiege et al

in Annals of the Rheumatic Diseases (2010, June), 69(Suppl.3), 602

Detailed reference viewed: 21 (2 ULiège)