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Peer Reviewed
See detailInfluence of the intrapleural pressure on the variability of the pulmonary arterial pressures measurements in calves
Amory, Hélène ULg; Art, Tatiana ULg; Gustin, Pascal ULg et al

in Proceedings of 7th comparative Respiratory Society Meeting, Chicago (USA) (1988)

Detailed reference viewed: 3 (0 ULg)
See detailInfluence of the ionospheric refraction on the repeatability of distances computed by GPS
Warnant, René ULg

in Proceedings of the ION GPS’ 97 meeting (1997)

Detailed reference viewed: 9 (0 ULg)
See detailInfluence of the ionospheric refraction on time transfer using GPS
Warnant, René ULg

in Proceedings of the 11 th. European Frequency and Time Forum (1997)

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See detailInfluence of the Ixodes ricinus tick blood-feeding on the antigen-specific antibody response in vivo.
Menten-Dedoyart, Catherine ULg; Couvreur, B.; Thellin, Olivier ULg et al

in Vaccine (2008), 26(52), 6956-64

The blood meal of hard ticks such as Ixodes ricinus lasts several days. This is made possible by tick salivary factors that inhibit inflammation, haemostasis and the host immune response. We assessed the ... [more ▼]

The blood meal of hard ticks such as Ixodes ricinus lasts several days. This is made possible by tick salivary factors that inhibit inflammation, haemostasis and the host immune response. We assessed the latter on a model of immune response in vivo. A significant reduction of specific IgM and IgG levels was observed in BALB/c mice infested 5 days before injection with bovine serum albumin (BSA) and QuilA but not in mice infested 5 days after the immunization. This effect was not observed in mock-infested mice and could not be attributed to the use of anesthetics. The antibody response was not merely delayed and the Th(1)/Th(2) balance appeared not altered. T-dependent zones and germinal centers in lymph nodes draining the tick bite site showed no apparent morphological alterations or shift in T cell subpopulations. However, the spleens of tick-infested mice had also an enlarged red pulp, indicating an increased extramedullary haematopoietic activity. [less ▲]

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See detailInfluence of the material model on local pull-in in electromechanical microdevices topology optimization
Lemaire, Etienne ULg; Van Miegroet, Laurent ULg; Duysinx, Pierre ULg et al

in PLATO-N International Workshop - Extended Abstracts (2009, September)

The appearance of local pull-in modes has been noticed during electromechanical microdevices topology optimization. The goal of the present research is to study the influence of material properties ... [more ▼]

The appearance of local pull-in modes has been noticed during electromechanical microdevices topology optimization. The goal of the present research is to study the influence of material properties (mechanical and electrical) modeling for intermediate densities to see if an appropriate choice allows avoiding such local modes. At first, a simple 1D model is developed to study the influence of the material properties interpolation. Finally, we evaluate if the conclusions from the 1D model can help to prevent the appearance of local modes for a 2D topology optimization problem. [less ▲]

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See detailInfluence of the matrix on analyte fragmentation in atmospheric pressure MALDI
Schulz, Eric; Karas, Michael; Rosu, Frédéric ULg et al

in Journal of the American Society for Mass Spectrometry (2006), 17(7), 1005-1013

In this paper, we report the measurement of the degree of analyte fragmentation in AP-MALDI as a function of the matrix and of the laser fluence. The analytes include p-OCH3-benzylpyridinium, three ... [more ▼]

In this paper, we report the measurement of the degree of analyte fragmentation in AP-MALDI as a function of the matrix and of the laser fluence. The analytes include p-OCH3-benzylpyridinium, three peptides containing the sequence EEPP (which cleave very efficiently at the E-P site), and three deoxynucleosides (dA, dG, and dC), which lose the neutral sugar to give the protonated base. We found that the matrix hardness/softness was consistent when comparing the analytes, with a consensus ranking from hardest to softest: CHCA >> DHB > SA approximate to THAP > ATT > HPA. However, the exact ranking can be fluence-dependent, for example between ATT and HPA. Our goal here was to provide the scientific community with a detailed dataset that can be used to compare with theoretical predictions. We tried to correlate the consensus ranking with different matrix properties: sublimation or decomposition temperature (determined using thermogravimetry), analyte initial velocity, and matrix proton affinity. The best correlation was found with the matrix proton affinity. [less ▲]

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See detailInfluence of the matrix on the In Source Decay of permethylated glycans during MALDI-TOF analysis
Smargiasso, Nicolas ULg; De Pauw, Edwin ULg

Poster (2010, June)

Introduction In source decay (ISD) is a common phenomenon occurring very rapidly during ionization process in the source of MALDI-MS instruments and resulting in the presence of well resolved peaks of ... [more ▼]

Introduction In source decay (ISD) is a common phenomenon occurring very rapidly during ionization process in the source of MALDI-MS instruments and resulting in the presence of well resolved peaks of fragments in mass spectrum. While they make interpretation of spectra more complex, these fragments were shown to be useful to sequence peptides and proteins. Concerning glycans, only a few reports were published, using different matrices on various samples and therefore making it difficult to compare. In this context, the goal of this work is to perform a systematic study allowing to define optimal conditions to induce ISD of glycans or, inversely, to minimize this phenomenon in the study of more complex mixtures. Methods Glycans were purchased from Sigma-Aldrich. Iodomethane was used in DMSO/NaOH to permethylate the glycans. This reaction was stopped by water and permethylated glycans were extracted by chloroform. Spectra were recorded on a Bruker Ultraflex II in positive ion mode. 2,5-dihydroxybenzoic acid (DHB) and 6-aza-2-thiothymine (ATT) were prepared at 20 mg/ml in 50 % acetonitrile, 0.1 % formic acid solution. 9-aminoacridine (9-AA) was dissolved at saturation in a 50 % acetonitrile, 0.1 % formic acid and further diluted 4 times in the same solution. α-Cyano-4-hydroxycinnamic (HCCA) acid was prepared at 20 mg/ml in 97 % acetone, 0,1 % formic acid. In some spots, LiI was added to obtain Li+ adducts instead of Na+ adducts. Preliminary data In source fragmentation of permethylated Lacto-N-difucoHexaose I and LS tetrasaccharide B was first studied in DHB. While the MS/MS of the Na+ adducts of these compounds (performed by LID) produces intenses B and Y fragments, those resulting from in source fragmentation are mainly oxonium ions, resulting from the cleavage of a glycosylic bond without any exchange of hydrogen atoms. These oxonium fragments were also obtained for lithium adducts. It was previously described that these fragments are produced by the cleavage of a protonated glycosidic bond. These ions carry their positive charge on a trivalent oxygen atom and are therefore not present on the spectra as sodium adducts. Since the peaks of protonated glycans are very low in MALDI spectra, it would indicate that protonation of glycosidic bonds of permethylated glycans would strongly favor a fragmentation reaction. Different matrices were tested to compare their ability to induce in source fragmentation of permethylated glycans. Interestingly, ATT gave similar results comparing to DHB while HCCA showed a lesser ability to promote in source fragmentation. However, the most striking result came from the use of 9-AA. This matrix, which is usually used in negative ion mode, was able to produce easily sodium adducts ions of permethylated glycan with a satisfying signal to noise ratio in positive ion mode. Moreover, practically no in source fragmentation was observed with this matrix. The few produced fragments were B ions but no oxonium ions were detected. Presence of these B fragments was increased for Li+ adducts. As 9-AA is the most basic of tested matrices, the absence of oxonium ions could result from its inability to transfer protons to the glycosidic bond of permethylated glycans. 9-AA could therefore become a matrix of choice to study complex mixtures of glycans, by reducing artefact peaks produced by ISD. Novel aspect ISD of permethylated glycans is induced by DHB while 9-AA strongly favors the presence of molecular ions. [less ▲]

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See detailInfluence of the media granular size of small pilot subsurface flow wetlands on axial dispersion and the hydraulic behaviour
Fonder, N.; Xanthoulis, Dimitri ULg

in Wetlands Systems for Water Pollution Control. (2008)

The objective of this paper is to evaluate using tracer tests, the role of the granular media size on the hydraulic behaviour of small -scale pilot horizontal subsurface flow (HSSF) gravel beds. The non ... [more ▼]

The objective of this paper is to evaluate using tracer tests, the role of the granular media size on the hydraulic behaviour of small -scale pilot horizontal subsurface flow (HSSF) gravel beds. The non-ideal flow was modelled by the tank-in-series model (TIS) using the moment analysis and Gamma distribution fitting using the Solver™ routine in Microsoft Excel™; the Plug Flow with Dispersion (PFD) model was also assessed. Tests were performed under a greenhouse in four identical pilot-scale gravel beds of 9:1:1 ratio, which received an equal, inflow of clear water. The influent flow rate was 40 L/day and the surface area of the pilot cells was 0.8 m². The pea gravel media used in the four beds were as follows: 3-5 mm, 6-8 mm, 8-10 mm and 10-12 mm. The tracer used was Potassium Bromide (KBr) with a concentration of 1 g Br/L, using a single-shot injection into the inlet distribution tubes. Tests were repeated three times, with identical materials and methods. Statistical differences were observed between replications. Water loss by evaporation of the unplanted gravel beds was of 11% for the smaller media size (3-5 mm) which is significantly different than the 4 to 5% obtained for the other media sizes. Tracer detention time, tracer peak time, volumetric and hydraulic efficiencies show all the same tendency which is a significant reduction with larger particles sizes. The two methods of calculation for the number NTIS by moment analysis and Gamma distribution fitting (using Solver™) are significantly different. The Gamma model increases the number of TIS with significantly higher values for smaller media sizes. [less ▲]

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See detailInfluence of the metal electronic properties on the sum-frequency generation spectra of dodecanethiol self-assembled monolayers on Pt (111), Ag (111) and Au (111) single crystals
Dreesen, Laurent ULg; Humbert, Christophe; Celebi, M. et al

in Applied Physics B : Lasers & Optics (2002), 74

Infrared-visible sum-frequency generation (SFG) spectroscopy is performed at different visible wavelengths between 450 and 650 nm in order to investigate the interaction between metallic substrates (Pt ... [more ▼]

Infrared-visible sum-frequency generation (SFG) spectroscopy is performed at different visible wavelengths between 450 and 650 nm in order to investigate the interaction between metallic substrates (Pt, Ag and Au) and 1-dodecanethiol self-assembled monolayers. We show that such measurements provide a means to study the electronic properties of metals as well as the interference phenomena between the SFG signals from the adsorbate and the substrate. The common features of the three interfaces are the vibration modes of the terminal methyl groups. However, these resonances appear as peaks for Pt (111) and as dips in the case of Ag (111). Their shape is not modified when the visible wavelength is tuned between 450 and 650 nm. Moreover, the metal sum-frequency generation contribution is slightly modified in that spectral range. For Au (111) samples, the sum-frequency generation spectrum drastically evolves with the visible wavelength: the peak resonant sum-frequency generation signal at 450 nm becomes rather dip-shaped at 650 nm. The non-linear response of gold is also enhanced when the wavelength associated with the sum-frequency process is close to 480 nm. These results are interpreted on the basis of the metal electronic properties that are responsible for the non-resonant contribution to the SFG signal. [less ▲]

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See detailInfluence Of The Mode Of Insertion Of Siv Peptides Into Membranes On The Structure Of Model Membrane As Studied By P-31 Nmr
Schanck, A.; Peuvot, J.; Brasseur, Robert ULg

in Biochemical and Biophysical Research Communications (1998), 250(1), 12-4

The influence on model membrane organization of a fusion peptide of SIV and of a nonfusogenic mutant of this peptide was examined by molecular modeling and by 31P NMR. The calculated mode of insertion of ... [more ▼]

The influence on model membrane organization of a fusion peptide of SIV and of a nonfusogenic mutant of this peptide was examined by molecular modeling and by 31P NMR. The calculated mode of insertion of the fusion peptide shows that it adopts an oblique orientation towards the lipid-water interface and that this fusion peptide induces a destabilization of the bilayer structure of multilamellar vesicles as evidenced by 31P NMR observations. The SIV mutant showing a more vertical insertion into lipid layers is unable to induce nonlamellar structures. This study reinforces the correlation between fusogenic activity, induction of structures not organized in extended bilayers, and calculated mode of insertion of peptides into lipid layers. [less ▲]

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See detailInfluence of the mode of walk on walking speed in multiple sclerosis: are you walking comfortably?
PHAN BA, Remy ULg; DELRUE, Gaël ULg; Pierard, Sébastien ULg et al

Poster (2013, June 10)

Introduction : Walking speed (WS) is the most frequent gait variable taken into account when measuring gait dysfunction in neurological diseases. Influences of the mode of walk instructed to the subject ... [more ▼]

Introduction : Walking speed (WS) is the most frequent gait variable taken into account when measuring gait dysfunction in neurological diseases. Influences of the mode of walk instructed to the subject, i.e. « as fast as possible » (AFAP) or « at a comfortable pace » (PrP) have not been well characterized in multiple sclerosis (MS). Objectives : to compare those 2 mode of walk in a population of persons with MS (pMS) and healthy volunteers (HV). Methods: WS was measured with a new automated device along a 25 foot distance (T25FW) as part of a multimodal evaluation of gait in an MS ambulatory department. Results: Baseline demographics between HV and pMS were comparable. Our first results demonstrate that (i) WS is obviously significantly higher in AFAP than in PrP both for pMS and HV (p < 0.001 for all comparisons) and (ii) the relative difference between AFAP and PrP WS is significantly higher in HV than in pMS (p < 0.001). The AFAP-PrP WS correlation is higher in pMS (r = 0.87, p < 0.001) than in HV (r = 0.51, p < 0.001). Finally, the relative difference between AFAP and PrP WS is significantly and negatively correlated with the PrP WS in HV (r = -0.41, p < 0.001) and pMS with mild to moderate disability (EDSS 0-3.5, r = -0.49, p < 0.01) but not in pMS with high disability (EDSS 4-5.5, r = 0.008). Conclusions : these results suggests that heatlhy subjects have access to a higher range of PrP WS than pMS and questions the regulation of PrP WS that might be under psychological or behavioural influences. The demonstration of a lower PrP-AFAP difference in MS suggests that pMS are either adopting a natural WS closer to their maximum WS, or alternatively that they can’t reach their maximum WS because of neurological impairments. Our results also emphasize the importance of the instructed mode of walk in the quantification of gait disorders both for routine clinical practice and clinical trials. [less ▲]

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See detailInfluence of the mucosal epithelium microenvironment on Langerhans cells: implications for the development of squamous intraepithelial lesions of the cervix
Giannini, Sandra ULg; Hubert, Pascale ULg; Doyen, Jean ULg et al

in International Journal of Cancer = Journal International du Cancer (2002), 97(5), 654-659

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See detailInfluence of the Nature of Calcium Salts on Serum Calcium, Phosphorus, Calcitonin, Growth Hormone, and Somatomedin C
Reginster, Jean-Yves ULg; Denis, D.; Albert, Adelin ULg et al

in Research in Experimental Medicine (1988), 188

Twenty healthy males were randomly divided into three groups. Each subject received either 405 mg elemental calcium (Ca) as a salt linked to an amino acid precursor, 405 mg CaC12 or 1000 mg Ca as Ca ... [more ▼]

Twenty healthy males were randomly divided into three groups. Each subject received either 405 mg elemental calcium (Ca) as a salt linked to an amino acid precursor, 405 mg CaC12 or 1000 mg Ca as Ca gluconolactate and carbonate. In all three cases, Ca intake led to an increase of serum Ca and TCT production and a decrease of PTH liberation. However, when Ca is linked to the amino acid precursor, an elective stimulation of growth hormone (GH) and somatomedin C (SmC) occurs. Due to the nature of its amino acid precursor, this salt seems to stimulate GH and SmC liberation through hypophysis. This could be a major pathway in decoupling of the sequence resorption-formation and therapy of metabolic bone diseases. [less ▲]

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See detailINFLUENCE OF THE NATURE OF SUGAR RESIDUES ON THE INTERACTIONS OF SYMETRIC SUGAR- BASED BOLAFORMS WITH MODEL MEMBRANES
Nasir, Mehmet Nail ULg; Crowet, Jean-Marc ULg; Lins, Laurence ULg et al

Poster (2013, November)

Glycolipid surfactants constitute a class of natural compound having interest in biological field such as antifungal, antiviral and plant-elicitor and for pharmaceutical formulation as well as for food ... [more ▼]

Glycolipid surfactants constitute a class of natural compound having interest in biological field such as antifungal, antiviral and plant-elicitor and for pharmaceutical formulation as well as for food and cosmetic field. Their action may be modulated through their interactions with plasma membranes of target cells and more particularly by their interactions with membrane lipid molecules. Among glycolipid surfactants, bolaforms constitute an important class; they are composed of two hydrophilic heads connected by a hydrophobic carbon segment.Their interest lies mainly in the development of the efficient and low cost lipid-based drug delivery systems. In this context, our work was focused on two sugar-based bolaforms. They are composed by two identical hydrophilic head constituted by xylose ( BolaX) or rhamnose ( BolaR), connected by an ether link to a hydrocarbon segment with an insaturation. The interactions of  BolaX and BolaR with model phopsholipid and phospholipid/sterol model membranes (Langmuir monolayers at the air-water interface and multilamellar vesicles) were investigated with biophysical and in silico approaches. Our results indicate that both bolaforms interact with model membranes at the level of hydrocarbon chain and, at the phosphate and the carbonyl group of phospholipids. The presence of sterol in the system has an influence on insertion of bolaforms and change slightly the nature of the interactions. The insertion of BolaR within a phospholipid bilayer was deeper than that of  BolaX and its interactions with phospholipids were energetically more favorable, suggesting an important role of the nature of sugar residue. [less ▲]

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See detailInfluence of the nature of the electrolyte on the chiral separation of basic compounds in nonaqueous capillary electrophoresis using heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin
Servais, Anne-Catherine ULg; Fillet, Marianne ULg; Chiap, Patrice ULg et al

in Journal of Chromatography. A (2005), 1068(1), 143-150

The influence on the enantiomeric resolution of the nature of the cationic BGE component (sodium, ammonium or potassium) and that of the anionic component (chloride, formate, methanesulfonate or ... [more ▼]

The influence on the enantiomeric resolution of the nature of the cationic BGE component (sodium, ammonium or potassium) and that of the anionic component (chloride, formate, methanesulfonate or camphorsulfonate) as well as the concentration of heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-cyclodextrin (HDMS-beta-CD), the selected chiral selector, was studied in nonaqueous capillary electrophoresis (NACE). For this purpose, two D-optimal designs with 33 and 26 experimental points were applied. Three beta-blockers (atenolol, celiprolol and propranolol) and three local anesthetics (bupivacaine, mepivacaine and prilocaine) were selected as basic model compounds. Both cationic and anionic BGE components were found to have a deep impact on the enantiomeric resolution of the investigated analytes but it is the cationic component that has shown the strongest influence. Indeed, in some cases, the change of the latter led to a complete loss of enantioresolution. Based on the observed results, two NACE systems were recommended, namely ammonium formate and potassium camphorsulfonate in a methanolic solution containing HDMS-beta-CD and acidified with formic acid, in order to separate efficiently the enantiomers of basic drugs. (c) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailInfluence of the non-linear modellings of beam-to-column joints on the structural response of braced and unbraced steel building frames.
Maquoi, René ULg; Jaspart, Jean-Pierre ULg

in proceedings of the Fourth international Colloquium on structural stability Mediterranean session (1991)

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See detailInfluence of the non-linearity of the aerodynamic coefficients on the skewness of the buffeting drag force
Denoël, Vincent ULg; Degée, Hervé ULg

in Wind and Structures (2006), 9(6), 457-471

This paper is devoted to the non linear quasi-steady aerodynamic loading. A linear approximation is often used to compute the response of structures to buffeting forces. Some researchers have however ... [more ▼]

This paper is devoted to the non linear quasi-steady aerodynamic loading. A linear approximation is often used to compute the response of structures to buffeting forces. Some researchers have however shown that it is possible to account for the non linearity of this loading. This non linearity can come (i) from the squared velocity or (ii) from the shape of the aerodynamic coefficients (as functions of the wind angle of attack). In this paper, it is shown that this second origin can have significant implications on the design of the structure, particularly when the non linearity of the aerodynamic coefficient is important or when the transverse turbulence is important. [less ▲]

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See detailInfluence of the nozzle capacity on the performance of a domestic fuel oil boiler
Ngendakumana, Philippe ULg; Masy, Cédric

in 2nd Edition of European Combustion Meeting (ECM 2005) (2005, April)

In order to investigate the influence of the nozzle capacity on the performance of fuel oil boilers, tests have been performed in transient and steady state regimes on our experimental boiler. The aim of ... [more ▼]

In order to investigate the influence of the nozzle capacity on the performance of fuel oil boilers, tests have been performed in transient and steady state regimes on our experimental boiler. The aim of the tests was to deduce the better couple nozzle - fuel injection pressure to reach the desired output power while producing fewer pollutants as possible. In short, a high fuel injection pressure associated with a low capacity nozzle is recommended. [less ▲]

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