Publications ORBi OA
Bookmark and Share    
Full Text
Peer Reviewed
See detailAlteration of left ventriculo-arterial coupling and mechanical efficiency during acute myocardial ischemia
Kolh, Philippe ULg; Lambermont, Bernard ULg; Ghuysen, Alexandre ULg et al

in International Angiology (2003), 22(2), 148-158

AIM: Myocardial revascularisation being frequently performed during acute myocardial ischemia, in a hostile hemodynamic environment, we evaluated left ventriculo-arterial (VA) coupling, left ventricular ... [more ▼]

AIM: Myocardial revascularisation being frequently performed during acute myocardial ischemia, in a hostile hemodynamic environment, we evaluated left ventriculo-arterial (VA) coupling, left ventricular (LV) mechanical efficiency, and the mechanical properties of the systemic vasculature during acute myocardial ischemia. METHODS: In 6 pigs, vascular properties [characteristic impedance (R(1)), peripheral resistance (R(2)), compliance (C), inductance (L), arterial elastance (E(a))] were estimated with a windkessel model. LV function was assessed by the slope (E(es)) of end-systolic pressure-volume relationship (ESPVR), and stroke work (SW) - end-diastolic volume (EDV) relation. Pressure-volume area (PVA) was referred to as myocardial oxygen consumption. VA coupling was defined as E(es)/E(a), and mechanical efficiency as SW/PVA. After baseline recordings, the left anterior descending coronary artery was ligated and hemodynamic measures obtained every 30 minutes for 3 hours. Data are expressed as mean (SEM). RESULTS: Coronary occlusion induced an ESPVR rightward shift, and decreased E(es) from 3.67 (0.33) to 1.92 (0.20) mmHg/ml and the slope of the SW - EDV relationship from 72.3 (3.4) to 40.4 (4.5) mmHg (p<0.001), while E(a) increased from 3.33 (0.56) to 4.65 (0.29) mmHg/ml (p<0.005). This was responsible for a dramatic alteration of VA coupling from 1.22 (0.11) to 0.44 (0.07), (p<0.001). While R2 increased from 1.72 (0.30) to 2.38 (0.16) mmHg x s x ml(-1) (p<0.05) and C decreased from 0.78 (0.16) to 0.46 (0.08) ml/mmHg (p<0.05), R(1) and L were unchanged. Coronary occlusion decreased SW from 4056 (223) to 2580 (122) mmHg.ml (p<0.001), while PVA and SW/PVA decreased from 5575 (514) to 4813 (317) mmHg x ml (NS), and from 0.76 (0.04) to 0.57 (0.03) (p<0.001), respectively. CONCLUSION: Acute myocardial ischemia severely altered left ventriculo-arterial coupling and LV mechanical efficiency. Impaired left VA coupling was due to a combination of augmented arterial elastance, secondary to early vasoconstriction later associated with decreased arterial compliance, and decreased LV contractility. [less ▲]

Detailed reference viewed: 34 (0 ULg)
Full Text
See detailApplication de l’échographie à l’ovum pick up chez la jument. Effet de la cystéamine sur la maturation des ovocytes équins mesuré par coloration au bis-benzamide et par transfert d’ovocytes.
Deleuze, Stefan ULg

Master's dissertation (2003)

Afin d’analyser l’effet de la cystéamine sur la maturation et la fécondation des ovocytes équins nous avons collecté des ovocytes par ponction folliculaire transvaginale échoguidée. Les ovocytes ont été ... [more ▼]

Afin d’analyser l’effet de la cystéamine sur la maturation et la fécondation des ovocytes équins nous avons collecté des ovocytes par ponction folliculaire transvaginale échoguidée. Les ovocytes ont été cultivés in vitro pendant 30 heures, puis transférés dans l’oviducte de juments receveuses inséminées. Nous avons utilisé le stade nucléaire après maturation in vitro comme critère de maturation nucléaire et les taux de production d’embryons après transfert d’ovocytes comme critère de maturation cytoplasmique. Contrairement à ce qui a été observé dans d’autres espèces, aucun effet positif de la cystéamine sur la maturation in vitro n’a pu être démontré par notre protocole. D’autres travaux sur les effets de la cystéamine et sur les mécanismes de la maturation in vitro des ovocytes équins sont nécessaires. [less ▲]

Detailed reference viewed: 18 (2 ULg)
Full Text
Peer Reviewed
See detailDose-dependent modulation of choroidal neovascularization by plasminogen activator inhibitor type 1: Implications for clinical trials
Lambert, Vincent ULg; Munaut, Carine ULg; Carmeliet, Peter et al

in Investigative Ophthalmology & Visual Science (2003), 44(6), 2791-2797

PURPOSE. To explain the conflicting reports about the influence of plasminogen activator inhibitor type (PAI-1) on pathologic angiogenesis, such as occurs during the exudative form of age-related macular ... [more ▼]

PURPOSE. To explain the conflicting reports about the influence of plasminogen activator inhibitor type (PAI-1) on pathologic angiogenesis, such as occurs during the exudative form of age-related macular degeneration. METHODS. The expression of PAI-1 mRNA was analyzed in human and murine choroidal neovascularization (CNV) by RTPCR. The influences of increasing doses of recombinant PAI-1 were evaluated by daily intraperitoneal injections in PAI-1-1-and wild-type animals with a model of laser-induced CNV. The double mechanism of action of PAI-1 (proteolytic activity inhibition versus vitronectin binding) was explored by immunohistochemical localization of fibrinogen/fibrin and by injection of recombinant PAI-1 protein defective for vitronectin binding or with adenoviral vectors bearing a mutated binding-deficient PAI-1 gene. RESULTS. PAI-1 expression was present in human CNV and strongly induced in the course of experimental subretinal neovascularization. Daily injections of recombinant PAI-1 proteins in control and PAI-1(-/-) animals demonstrated that PAI-1 could exhibit both pro- and antiangiogenic effects, dependent on the dose. PAI-1 mutants defective for vitronectin binding were used to show that PAI-1 promotes choroidal pathologic angiogenesis merely through its antiproteolytic activity. CONCLUSIONS. These observations may help to reconcile reports with opposite results regarding the effects of PAI-1 on angiogenesis and certainly warn against uncontrolled use of PAL I modulating drugs in clinical trials. [less ▲]

Detailed reference viewed: 32 (4 ULg)
Full Text
See detailPolyneuritis equi. Literatuurstudie & retrospectieve studie
Van Galen, Gaby ULg

Master's dissertation (2003)

Detailed reference viewed: 32 (0 ULg)
Full Text
Peer Reviewed
See detailLa prise en charge cardiaque preoperatoire du patient vasculaire
Van Damme, Hendrik ULg; Larbuisson, Robert ULg; Limet, Raymond ULg

in Revue Médicale de Liège (2003), 58(6), 409-14

Peripheral vascular surgery (carotid, infrainguinal or aortoiliacal) is characterised by an increased cardiac risk with an infarction rate of 1 to 4%. Sixty percent of the vascular patients present a ... [more ▼]

Peripheral vascular surgery (carotid, infrainguinal or aortoiliacal) is characterised by an increased cardiac risk with an infarction rate of 1 to 4%. Sixty percent of the vascular patients present a concomitant coronary artery disease, often infraclinically. Preoperative cardiac risk stratification aims at reducing cardiac related morbidity and mortality. A clinical risk profile (patient's past history) and non-invasive cardiac tests allow subdividing the vascular patients into three categories: high risk, intermediate risk, and low risk. High-risk patients (unstable angina, recent infarction, overt congestive heart failure and critical aortic valve stenosis) require immediate intensive management of their underlying cardiac disease. This means delay or annulation of the planned vascular operation. For intermediate risk patients, a clinical cardiac risk index based on patient's past history (stable angina, previous infarction or episode of congestive heart failure, age of 70 years or more and diabetes) offers a rough orientation. These clinical markers lack specificity, since they are found in almost all vascular patients. The adjunction of a non-invasive cardiac testing allows to optimise the cardiac risk evaluation. Stress echocardiography with dobutamine has become a very popular test, with a negative predicting value exceeding 90%, but with a lack of specificity (many vascular patients have an uneventful postoperative outcome, despite a positive dobutamine test). These inconsistent results of cardiac risk evaluation render their routine use questionable. Nowadays, the management of patients requiring vascular surgery is based on the concept that every vascular patient should be considered as suffering from coronary artery disease. A certain degree of myocardial protection should be offered to every vascular surgery candidate. A preoperative treatment with betablockers provides myocardial protection against the operative stress and lowers myocardial oxygen requirement. There are arguments to continue or start aspirin treatment in the preoperative period, in order to lower the risk of sudden coronary thrombosis. [less ▲]

Detailed reference viewed: 31 (3 ULg)
Full Text
Peer Reviewed
See detailPrevention de la necrose des membres inferieurs et de l'amputation par pontages femoro-tibiaux: indications, technique et resultats
Van Damme, Hendrik ULg; Baguet, E.; Zhang, Lihong ULg et al

in Revue Médicale de Liège (2003), 58(6), 415-28

Limb threatening ischemia is a challenge for the vascular surgeon. Recent progress in revascularization procedures allow to minimize the primary amputation rate in the management of chronic critical limb ... [more ▼]

Limb threatening ischemia is a challenge for the vascular surgeon. Recent progress in revascularization procedures allow to minimize the primary amputation rate in the management of chronic critical limb ischemia. The authors discuss the prevalence and causes of chronic critical limb ischemia, with a special interest for diabetic arteriopathy. The technique of crural and pedal vessel revascularization is described, as well as the innovative tourniquet technique for distal bypass surgery. A review of published series of infrapopliteal bypass surgery is made. The experience of the authors during last decade with crural and pedal bypass surgery is analyzed. [less ▲]

Detailed reference viewed: 115 (1 ULg)
Full Text
Peer Reviewed
See detailAnisotropic AC behavior of multifilamentary Bi-2223/Ag tapes
Fagnard, Jean-François ULg; Vanderbemden, Philippe ULg; Cloots, Rudi ULg et al

in IEEE Transactions on Applied Superconductivity (2003), 13(2, Part 3), 2976-2979

In this communication, we report on the anisotropy of the superconducting properties of multifilamentary Bi-based tapes experimentally investigated by AC magnetic susceptibility measurements. The ... [more ▼]

In this communication, we report on the anisotropy of the superconducting properties of multifilamentary Bi-based tapes experimentally investigated by AC magnetic susceptibility measurements. The susceptibility X = X' - jX" was measured using a commercial system and a couple of orthogonal pick-up coils. The X'' vs. temperature curves were shown to exhibit two peaks. The smaller of the peaks, occurring near T = 72 K, was only visible for particular field directions and within a given frequency window. Such results point out the role played by the phase difference between the applied magnetic field and the internal magnetic field seen by the filaments. (C) 2003 IEEE. [less ▲]

Detailed reference viewed: 63 (28 ULg)
Full Text
See detailSolution of topology optimization problems with sequential convex programming
Duysinx, Pierre ULg; Bruyneel, Michaël ULg; Fleury, Claude ULg

Speech (2003)

Introduction to efficient solution algorithms to large scale topology optimization problems.

Detailed reference viewed: 56 (4 ULg)
Full Text
Peer Reviewed
See detailOral monthly ibandronate: rationale and clinical potential in postmenopausal osteoporosis
Reginster, Jean-Yves ULg; McClung, M.; Coutant, K. et al

in Annals of the Rheumatic Diseases (2003, June)

Detailed reference viewed: 24 (11 ULg)
Full Text
Peer Reviewed
See detailBehavior of bulk melt-textured YBCO single domains subjected to crossed magnetic fields
Vanderbemden, Philippe ULg; Dorbolo, Stéphane ULg; Hari-Babu, N. et al

in IEEE Transactions on Applied Superconductivity (2003), 13(2, Part 3), 3746-3749

We have experimentally investigated the crossed magnetic field effects on bulk melt-processed YBCO single domains. The samples were first permanently magnetized along their c-axis and then subjected to ... [more ▼]

We have experimentally investigated the crossed magnetic field effects on bulk melt-processed YBCO single domains. The samples were first permanently magnetized along their c-axis and then subjected to several cycles of a transverse magnetic field parallel to the ab planes. The magnetic properties along the c and ab directions were simultaneously measured using a couple of orthogonal pick-up coils as well as a Hall probe placed against the sample surface. The effects of both sweep amplitude and polarity were investigated. Field sweeps of alternate polarities are shown to affect the decay of the c-axis magnetization much more strongly than field sweeps of unique polarity do. However, the c-axis magnetization does not show any saturation even after a large number of field sweeps. Next, a micro-Hall probe scanning system was used to measure the distribution of magnetic induction over the top surface of the single domain subjected to the same combination of magnetic fields. The results are shown to be consistent with those determined with the sensing coils and bring out the role played by geometric effects. (C) 2003 IEEE. [less ▲]

Detailed reference viewed: 39 (16 ULg)
Full Text
Peer Reviewed
See detailDesorption behaviour of regular adsorbed polyampholytic layers
Mahltig, Boris; Gohy, Jean-François; Jérôme, Robert ULg et al

in Journal of Polymer Research (2003), 10(2), 69-77

The desorption behaviour of the diblock polyampholyte PMAA-b-PDMAEMA, poly(methacrylic acid)-block-poly ((dimethylamino)ethyl methacrylate), preadsorbed on silicon substrates was investigated under the ... [more ▼]

The desorption behaviour of the diblock polyampholyte PMAA-b-PDMAEMA, poly(methacrylic acid)-block-poly ((dimethylamino)ethyl methacrylate), preadsorbed on silicon substrates was investigated under the influence of several desorption agents. The investigated polyampholyte is known to adsorb in regular structures directly from aqueous solutions onto silicon substrates. While the adsorption process is mainly determined by electrostatic interactions, two kinds of desorption mechanism should be assumed. The first mechanism is based on changed electrostatic conditions caused for instance by a strong change in pH of the aqueous solution. The other mechanism is observed after treatment with hydrophobic organic solvent, which leads to the desorption of hydrophobic adsorbed polyampholyte chains, while the electrostatically attached ones will not be influenced. To complete the desorption experiments with organic solvents also adsorption experiments from analogous polyampholytic solutions in the same organic solvents were performed. The amount of polymer at the substrate surface after adsorption or desorption experiments was determined using ellipsometry. Atomic force microscopy (AFM) was used to investigate the surface topography of dried samples after the desorption process. [less ▲]

Detailed reference viewed: 14 (0 ULg)
Full Text
Peer Reviewed
See detailLa vaccination a base de mycobacteries: vaincra-t-elle les allergies?
Louis, Renaud ULg

in Revue Médicale de Liège (2003), 58(6), 392-5

In developed countries, the prevalence of tuberculosis has evolved in an opposite direction as to the one of allergy over the last century. The immunological response is mainly Th1 in tuberculosis while ... [more ▼]

In developed countries, the prevalence of tuberculosis has evolved in an opposite direction as to the one of allergy over the last century. The immunological response is mainly Th1 in tuberculosis while it features a Th2 pattern in allergy. Vaccination with BCG in early life is associated with a reduction in the prevalence of allergy later in childhood. In an experimental mouse model of asthma, administration of BCG or killed Mycobacterium vaccae inhibits the sensitisation process as well as the bronchial inflammation and hyperresponsiveness that follows allergen exposure. In children and adolescents suffering from atopic dermatitis, subcutaneous injection of killed Mycobacterium vaccae attenuates the severity of skin lesions. [less ▲]

Detailed reference viewed: 47 (0 ULg)
Full Text
Peer Reviewed
See detailLong-term memory effects on verbal short-term memory : a replication study
Majerus, Steve ULg; Van der Linden, Martial ULg

in British Journal of Developmental Psychology (2003), 21(Part 2), 303-310

The influence of lexico-semantic language representations stored in long-term memory (LTM) on short-term memory (STM) performance has been studied extensively in adults. However, there are relatively few ... [more ▼]

The influence of lexico-semantic language representations stored in long-term memory (LTM) on short-term memory (STM) performance has been studied extensively in adults. However, there are relatively few data on lexico-semantic LTM effects on STM in children. On the other hand, the influence of phonological LTM effects on STM has been studied more extensively in children than in adults. In this study, we explored whether these different LTM effects on verbal STM could be replicated in both adults and children by administering immediate serial recall tasks (ISR) for high- and low-frequency words, for high- and low-imageability words, for words and non-words, and for high and low phonotactic frequency non-words to 6-, 8-, and 10-year-old children, to adolescents and to adults. Significant word frequency, lexicality and phonotactic frequency effects were observed in all age groups, as well as a word imageability effect which was, however, weaker than the other three effects. Our data suggest that LTM effects on STM are equivalent in both children and adults. [less ▲]

Detailed reference viewed: 42 (5 ULg)
Full Text
See detailCommunication, positionnement et GPS
Debouche, Charles ULg

in Journal des Ingénieurs (Le) (2003), 87

Detailed reference viewed: 20 (4 ULg)
Full Text
Peer Reviewed
See detailFuzzy K-NN applied to moulds detection
Kuske, Martyna; Rubio, R.; Nicolas, Jacques ULg et al

in Proceedings of ISOEN'03 (2003, June)

The possibility to detect Aspergillus versicolor growing on different building materials by a metal oxide sensor array is studied. Results show that an accurate classification rate of 89 +/- 3% can be ... [more ▼]

The possibility to detect Aspergillus versicolor growing on different building materials by a metal oxide sensor array is studied. Results show that an accurate classification rate of 89 +/- 3% can be obtained combining an extended linear discriminant analysis plus a fuzzy k-NN classifier. The classification ability of the classifier is assessed within the dataset by crossvalidation and also in a second dataset collected 5 months later. There is a slight decrease in the classification performance for all the algorithms, being the most sensitive the most accurate one. [less ▲]

Detailed reference viewed: 21 (4 ULg)
Full Text
Peer Reviewed
See detailA new tool for testing transmitter's implantation impact on fish: the computerized video tracking
Jadot, Catherine; Donnay, Annick ULg; Ylieff, Marc ULg et al

Poster (2003, June)

Detailed reference viewed: 6 (2 ULg)
Full Text
Peer Reviewed
See detailPreparation of BaZrO3 powders by a spray-drying process
Robertz, B.; Boschini, Frédéric ULg; Rulmont, André ULg et al

in Journal of Materials Research (2003), 18(6), 1325-1332

The potential use of barium zirconate for the manufacture of corrosion-resistant substrates emphasizes the need for a simple, inexpensive, and easily scalable process to produce high-quality powders with ... [more ▼]

The potential use of barium zirconate for the manufacture of corrosion-resistant substrates emphasizes the need for a simple, inexpensive, and easily scalable process to produce high-quality powders with well-controlled composition and properties. However, the classical solid-state preparation of barium zirconate leads to an inhomogeneous powder unsuitable for applications in highly corrosive environment. For this paper, the possibility to use the spray-drying technique for the preparation of BaZrO3 powders with a controlled size distribution and morphology was investigated. The influence of the nature and concentration of the precursor solution and the influence of the spray-drying step are discussed on the basis of x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and dilatometric measurements. [less ▲]

Detailed reference viewed: 54 (4 ULg)
Full Text
See detailCaractérisation des fluides bi-phasiques cryogéniques par absorption différentielle de rayonnements gamma
Carapelle, Alain ULg

Master of advanced studies dissertation (2003)

Detailed reference viewed: 60 (8 ULg)