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See detailInterface mousse-liquide
Bronfort, Ariane ULg

Conference (2011, March 17)

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See detailL’interface neuro-immune et l’expression de la protéine prion cellulaire dans le cadre des maldies à prions. Une étude comparative des espèces bovine et humaine.
Defaweux, Valérie ULg

Doctoral thesis (2007)

Le tropisme cellulaire des prions infectieux diffère selon l’espèce animale, celui-ci est corrélé à la souche infectieuse et à des facteurs spécifiques de l’hôte. Par exemple, certains prions infectieux ... [more ▼]

Le tropisme cellulaire des prions infectieux diffère selon l’espèce animale, celui-ci est corrélé à la souche infectieuse et à des facteurs spécifiques de l’hôte. Par exemple, certains prions infectieux sont lymphotropiques, notamment en cas de scrapie chez les moutons et de variant de la maladie de Creutzfeldt-Jakob (vMCJ) chez l’homme. Par opposition, certains prions se caractérisent par un neurotropisme comme observé chez des patients Creutzfeldt-Jakob atteints de la forme sporadique ou chez des bovins atteints d’encéphalopathies spongiformes bovines (ESB). L’hypothèse de notre travail repose sur les observations suivantes : dans le cas du variant de la maladie de Creutzfeldt-Jakob et des encéphalopathies spongiformes bovines, l’agent responsable est identique, la voie d’inoculation et les lésions neurologiques le sont également, seul le tropisme de cette souche pour les organes lymphoïdes diffère. En effet, les amygdales, la rate et l’appendice sont infectieux chez l’homme. Par contre, l’infectiosité est surtout confinée au niveau du système nerveux chez le bovin. Lors d’une inoculation expérimentale par voie orale de l’agent responsable de l’ESB chez les bovins, les plaques de Peyer iléales sont les seuls tissus lymphoïdes infectieux. Notre hypothèse de travail est que des propriétés de l’hôte interviennent dans le tropisme de l’agent infectieux. Deux axes de recherche ont été envisagés afin de vérifier cette hypothèse :  L’analyse de la distribution des fibres nerveuses au sein des tissus lymphoïdes associés aux muqueuses (MALT) des espèces bovine et humaine  L’étude de l’expression de PrPc et de ses isoformes au sein des tissus lymphoïdes et nerveux des espèces bovine et humaine. Pour atteindre au mieux nos objectifs, il nous manquait un outil essentiel permettant la caractérisation spécifique des FDC bovines. En effet, aucun marqueur spécifique de ces cellules n’était commercialisé. Nous avons donc produit, en collaboration avec le Centre d’Economie Rural de Marloie, un anticorps monoclonal spécifiquement dirigé contre les cellules folliculaires dendritiques (FDC) bovines. Cet anticorps nous a permis d’étudier la distribution des FDC au sein des organes lymphoïdes bovins. Une attention particulière a été portée aux FDC isolées à partir des plaques de Peyer jéjunales (PPJ) et iléales (PPI). L’apparente différence d’infectivité de ces tissus lymphoïdes chez des bovins atteints expérimentalement d’ESB nous a conduit à comparer les capacités fonctionnelles des FDC isolées à partir de PPJ et de PPI. Ces observations sont décrites et discutées dans le chapitre 1. Dans le chapitre 2, nous avons établi une cartographie des fibres nerveuses au sein des amygdales, des plaques de Peyer iléales et jéjunales bovines de plusieurs catégories d’âge et ensuite comparé ce pattern d’innervation à celui des amygdales humaines; ceci permettra de pister les voies potentielles de neuro-invasion. Une attention particulière a été portée à l’interface cellules folliculaires dendritiques – fibres nerveuses. En effet, les FDC matures jouent un rôle prépondérant dans la pathogenèse des maladies à prion puisqu’en leur absence, une infection périphérique n’a pas lieu. De plus, la proximité entre fibres nerveuses et FDC est un paramètre intervenant dans la neuro-invasion; nous avons dès lors aussi analysé les contacts entre les FDC et les éléments nerveux. L’expression de la PrPc est une condition sine qua non pour la formation de PrPres. Cette protéine cellulaire sert probablement de récepteur pour son homologue infectieux mais sert surtout de substrat pour l’amplification de PrPres ; toute modification au niveau de sa synthèse pourrait entraîner un changement de la cinétique d’infection et pourrait expliquer l’apparente absence d’infectivité constatée au niveau du système immunitaire chez les bovins. L’expression tissulaire et cellulaire spécifique d’isoformes de la PrPc représente un facteur de l’hôte potentiellement capable d’influencer le tropisme cellulaire de l’agent infectieux chez l’humain et le bovin. Cette expression a été étudiée dans les systèmes MALT bovins et humains. Pour affiner notre étude, nous avons analysé, par des techniques de western-blotting, le glycopattern de la PrPc ainsi que l’expression de ses formes tronquées dans les tissus lymphoïdes humains et bovins mais également dans des populations cellulaires spécifiques, les lymphocytes et les FDC. Afin de vérifier si les isoformes de PrPc sont spécifiques aux tissus lymphoïdes, nous avons effectué une étude comparative du pattern de glycosylation et du ratio des formes clivées de PrPc, exprimés au sein de différentes régions du système nerveux central bovin et humain. Les résultats de ces travaux sont repris dans le chapitre 3. [less ▲]

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See detailInterface Physics in Complex Oxide Heterostructures
Zubko, Pavlo; Gariglio, Stefano; Gabay, Marc et al

in Annual Review of Condensed Matter Physics (2011), 2

Complex transition metal oxides span a wide range of crystalline structures and play host to an incredible variety of physical phenomena. High dielectric permittivities, piezo-, pyro-, and ... [more ▼]

Complex transition metal oxides span a wide range of crystalline structures and play host to an incredible variety of physical phenomena. High dielectric permittivities, piezo-, pyro-, and ferroelectricity are just a few of the functionalities offered by this class of materials, while the potential for applications of the more exotic properties like high temperature superconductivity and colossal magnetoresistance is still waiting to be fully exploited. With recent advances in deposition techniques, the structural quality of oxide heterostructures now rivals that of the best conventional semiconductors, taking oxide electronics to a new level. Such heterostructures have enabled the fabrication of artificial multifunctional materials. At the same time they have exposed a wealth of phenomena at the boundaries where compounds with different structural instabilities and electronic properties meet, giving unprecedented access to new physics emerging at oxide interfaces. Here we highlight some of these exciting new interface phenomena. [less ▲]

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See detailInterface-croquis pour relevés architecturaux: vers la constitution d'une nouvelle activité
Safin, Stéphane ULg; Pecceu, S.; Leclercq, Pierre ULg

in Agon, C.; Delerue, O. (Eds.) Proceedings of the 19th International Conference of the Association Francophone d'Interaction Homme-Machine, IHM (2007)

This article is the synthesis of the ICC research project, aiming at the development of a multimodal and portable interface supporting in real time scale setting of an architectural measurement sketch ... [more ▼]

This article is the synthesis of the ICC research project, aiming at the development of a multimodal and portable interface supporting in real time scale setting of an architectural measurement sketch. Based on a participative process, we first expose and make a model of the traditional activities of measure taking and scale setting. We then describe the ICC software and show how the retooled activity changes, taking into account the help functions it brings. We describe the new structure of measurement activity with scale setting, the new drawing modes it induces. We conclude proposing some tracks for the software improvement. [less ▲]

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See detailInterface-esquisse effacée en ingénierie de conception
Leclercq, Pierre ULg

in Proceedings de la 14ème conférence francophine sur l'Interaction Homme-Machine IHM'02 (2002)

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See detailInterfaces between dendritic cells, other immune cells, and nerve fibres in mouse Peyer's patches: Potential sites for neuroinvasion in prion diseases
Defaweux, Valérie ULg; Dorban, Gauthier ULg; Demonceau, Christine ULg et al

in Microscopy Research and Technique (2005), 66(1), 1-9

In this study, we examined where immune cells and nerve fibres are located in mouse Peyer's patches, with a view to identifying potential sites for neuroinvasion by prions. Special attention was paid to ... [more ▼]

In this study, we examined where immune cells and nerve fibres are located in mouse Peyer's patches, with a view to identifying potential sites for neuroinvasion by prions. Special attention was paid to dendritic cells, viewed as candidate transporters of infectious prion. Double immunofluorescence labellings with anti-CD11c antibody and marker for other immune cells (B cells, T cells, follicular dendritic cells) were carried out and analysed by confocal microscopy on Peyer's patch cryosections. To reveal the extensive ganglionated networks of the myenteric and submucosal plexi and the sparse meshworks of nerve strands, we used antibodies directed against different neurofilament subunits or against glial fibrillary acidic protein. In the suprafollicular dome, dendritic cells connect, via their cytoplasmic extensions, enterocytes with M cells of the follicle-associated epithelium. They are also close to B and T cells. Nerve fibres are detected in the suprafollicular dome, notably in contact with dendritic cells. Similar connections between dendritic cells, T cells, and nerve fibres are seen in the interfollicular region. Germinal centres are not innervated; inside them dendritic cells establish contacts with follicular dendritic cells and with B cells. After immunolabelling of normal prion protein, dendritic cells of the suprafollicular dome are intensely positive labelled. (c) 2005 Wiley-Liss, Inc. [less ▲]

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See detailInterfacial agents for polymer/liquid crystal dispersions
Gohy, Jean-François; Jérôme, Robert ULg

in Macromolecular Chemistry and Physics (1996), 197(7), 2209-2217

Liquid crystals (LC) were covalently and ionically bonded to one (or both) end(s) of polystyrene chains. These compounds were tested as interfacial agents in polystyrene/ liquid crystal dispersions. In ... [more ▼]

Liquid crystals (LC) were covalently and ionically bonded to one (or both) end(s) of polystyrene chains. These compounds were tested as interfacial agents in polystyrene/ liquid crystal dispersions. In case of covalent bonding, the additive is too much "soluble" in polystyrene and no interfacial activity is observed. Ionic bonding of the LC to polystyrene chains deeply changes the situation, all the other conditions being the same, The dipolar interactions of the ion pairs are clearly favorable to the localization of the additive at the polymer/LC interface. The higher polarity of the ammonium sulfonate pairs com-pared to the parent ammonium carboxylate ion pairs accordingly accounts for a higher interfacial activity. [less ▲]

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See detailInterfacial and emulsifying properties of Bacillus suvtilis lipopeptides
Deleu, Magali ULg; Razafindralambo, Hary ULg; Popineau, Yves et al

Poster (1997)

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See detailInterfacial and emulsifying properties of lipopeptides from Bacillus subtilis
Deleu, Magali ULg; Razafindralambo, Hary ULg; Popineau, Y. et al

in Colloids and Surfaces A : Physicochemical and Engineering Aspects (1999), 152(1-2), 3-10

The fundamental surface-active properties at the oil/water interface and emulsifying properties of surfactin, iturin A and fengycin, lipopeptides from Bacillus subtilis, were investigated. All ... [more ▼]

The fundamental surface-active properties at the oil/water interface and emulsifying properties of surfactin, iturin A and fengycin, lipopeptides from Bacillus subtilis, were investigated. All lipopeptides reduce rapidly the dynamic interfacial tension. Among lipopeptide families, surfactin is the most effective in terms of fundamental dynamic and equilibrium interfacial properties. Lipopeptides present intermediate properties in comparison with sodium dodecyl sulfate and beta-lactoglobulin concerning the stabilizing effect towards creaming-flocculation and the resistance to coalescence. Among lipopeptides, iturin A seems to show the best resistance to creaming-flocculation whereas fengycin exhibits the highest resistance to coalescence properties. (C) 1999 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailInterfacial and Foaming Properties of Two Types of Total Proteose-Peptone Fractions
Karamoko, Gaoussou ULg; Danthine, Sabine ULg; Olive, Gilles ULg et al

in Food and Bioprocess Technology (2013), 6(8), 1944-1952

Total proteose-peptone (TPP) fractions were extracted from skimmed milk (UHT) and whey protein concentrate (WPC) on a laboratory scale. Protein solutions (0.1 %, 0.5 %, and 1 % w/w) were characterized as ... [more ▼]

Total proteose-peptone (TPP) fractions were extracted from skimmed milk (UHT) and whey protein concentrate (WPC) on a laboratory scale. Protein solutions (0.1 %, 0.5 %, and 1 % w/w) were characterized as function of pH: 4.0, 4.6–4.7 (native pH), and 7.0. Their foaming capacities and stabilities were studied. Beforehand, the surface properties that govern them were investigated, notably the kinetics of adsorption and mechanical properties of monolayer films at the air–water interface involved in the formation and the stability of foams respectively. The TPP extracted from skimmed milk showed the lowest values as well as a significant reduction in surface tension and presented a good mechanically resistant film. The TPP extracted from WPC presented a better foaming capacity and stability which was unexpected. However, foaming properties and surface properties of TPP fractions depended on the pH. The considerable influence of extraction source and method on proteosepeptone’s properties were highlighted. [less ▲]

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See detailInterfacial area measurement in a catalytic distillation packing using high energy x-ray CT
Aferka, Saïd ULg; Marchot, Pierre ULg; Crine, Michel ULg et al

in Chemical Engineering Science (2010), 65(1), 511-516

In this paper, we report on the use of X-ray tomography to visualize and quantify the gas–liquid interfacial area in modular catalytic distillation packing elements. The calculation method is based on ... [more ▼]

In this paper, we report on the use of X-ray tomography to visualize and quantify the gas–liquid interfacial area in modular catalytic distillation packing elements. The calculation method is based on processing of tomographic images. It is validated by comparing specific surface area determined on dry packings (Mellapak™ 752Y and Katapak™ SP12) tomographic binary images (gas and solid) to values announced by manufacturers, based on geometrical considerations. These data agree fairly well. However, tomographic images show that the specific area is not distributed uniformly over the height of a packing element due to the presence of perforations in corrugated sheets and of wall wipers between the packing and the column wall. X-ray tomography is a unique technique to access to the spatial distribution of these geometrical details in a non-intrusive way. The method used to determine the specific surface area of dry packing is then applied to irrigated packing in order to determine the gas–liquid interfacial area. The axial distribution of the interfacial area is non-uniform and is correlated to the packing specific area. The maxima of the specific surface area correspond to the presence of wall wipers. The gas–liquid interfacial area averaged over the column length is determined. It increases logically with the liquid superficial velocity and slightly with the gas velocity. The effect of the gas velocity is however more pronounced when reaching loading point. [less ▲]

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See detailInterfacial phenomena in carbon fibre reinforced magnesium alloys processed by squeeze casting and thixomolding
Montrieux, Henri-Michel ULg; Mertens, Anne ULg; Halleux, Jacques et al

Conference (2011, September)

Composite materials are known to combine interesting properties of different materials. This research concerns magnesium alloys reinforced by carbon fibre weaves. Such a material can theoretically exhibit ... [more ▼]

Composite materials are known to combine interesting properties of different materials. This research concerns magnesium alloys reinforced by carbon fibre weaves. Such a material can theoretically exhibit a high yield strength/density ratio. This composite is thought to be especially promising for aeronautics. A pre-treatment of carbon weaves ensure two fundamental functions. The first is to provide stiffness and cohesion. It helps keeping fibres aligned and well placed in the mould during casting to ensure optimal properties of the final part in the main load directions. This is imperative when the composite is formed with thixomolding for which semi liquid metal is injected with a very high speed. Nevertheless the problem of geometrical carbon weaves stability is also encountered with squeeze casting. The second objective of the pre-treatment is to provide a porous network in the weaves to enhance infiltration by the capillary action. The two functions can be assumed by coating fibres with Al(H2PO4)3, SiO2 combined with starch, or some other oxide containing mixtures. The general process is to assemble carbon weaves, infiltrate them in an aqueous solution or dispersion of oxides and lastly heat them at high temperature to promote covalent bonds with fibres and vaporize or crack carbonaceous agents to let a porous medium. Further the chemical interaction between the coated fibres and the liquid metal during infiltration can influence the species which are present at the interfaces. As magnesium oxide is stable magnesium can react with oxides. This could lead to better wettability of treated weave. However such chemical reactions seem to be thermally activated and take many seconds to initiate, whereas solidification of magnesium is achieved faster. Furthermore the addition of some carbide former elements (Si, Ti, Zr) to a magnesium based alloy can also influence chemical affinity. In conclusion CMg-MMC research concerns composites with low density, high potential mechanical properties and possibility of processing through thixomolding. Firstly the reach of the theoretical performance of the composite includes the ability of dealing with the interaction between fibres and liquid metal. Secondly primary treatment could help to form bonds between matrix and fibres, make rigid weaves and promote a further infiltration. Thirdly chemical affinity between the fibres, magnesium alloy and coating can influence the infiltration. [less ▲]

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See detailInterfacial properties and structure stability of the gp41 tryptophan-rich peptide from HIV-1
Matar, Gladys; Nasir, Mehmet Nail ULg; Besson, Françoise

in Journal of Colloid & Interface Science (2010), 352

The HIV-1 envelope glycoprotein 41 (gp41) undergoes large-scale conformational changes in order to induce the fusion of the virus and cell membranes. Thus, we investigated a possible structure transit at ... [more ▼]

The HIV-1 envelope glycoprotein 41 (gp41) undergoes large-scale conformational changes in order to induce the fusion of the virus and cell membranes. Thus, we investigated a possible structure transit at the air-water interface for the tryptophan-rich peptide of gp41 (gp41W). The synthetic peptide (KWASLWNWFNITNWLWYIK), corresponding to gp41W, shows interfacial properties on pure water and Tris buffer at pH 8.5. Isotherm measurements and Brewster angle microscopy (BAM) imaging showed that the behavior of the peptide monolayer was dependent on the subphase composition. A homogenous film was formed on buffer during the peptide monolayer compression, while the appearance of condensed domains on pure water could indicate the oligomerization of gp41W during the surface pressure increase. Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) showed that, whatever the subphase, gp41W adopts an α-helix structure at the air-water interface and does not transit for any other structure even at high surface pressures. [less ▲]

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See detailInterfacial Properties Of Gluten Monolayers Spread On Various Chloride Salt Solutions. Effects Of Electrolytes, Salt Concentrations, And Temperature
Balla, A.; Razafindralambo, Hary ULg; Blecker, Christophe ULg et al

in Journal of Agricultural and Food Chemistry (1998), 46(9), 3535-3539

The interfacial behavior of gluten powder spread as a monolayer on aqueous phases containing various chloride salts was studied. The presence of electrolytes at low concentrations reduced the expansion ... [more ▼]

The interfacial behavior of gluten powder spread as a monolayer on aqueous phases containing various chloride salts was studied. The presence of electrolytes at low concentrations reduced the expansion and stability of the gluten monolayers compared to the results obtained with pure water. At low salt concentrations, no effect of the electrolyte nature was detectable (compression curves were superimposed for Na+, K+, and Ca2+). However, when salt concentrations increased from 0.05 to 0.5 M, the influence of the electrolyte nature on gluten film expansion appeared clearly. Divalent cations (Ca2+) gave films with greater expansion than monovalent cations (K+, Na+). Between the monovalent cations, Na+ had a greater effect on gluten film expansion than did K+. Gluten monolayer expansion evaluated by limiting the area (A0) passed through a minimum when the salt concentrations increased from 0 to 0.5 M. The temperature also influenced the behavior of gluten monolayers as attested by A0 and film elasticity values which decreased with temperature. The energy of compression (ΔGc) that measures the intermolecular forces between film-forming molecules was generally higher on Ca2+ than on K+ and Na+, showing that Ca2+ induced stronger interactions than K+ or Na+. The ΔGc − T plots showed that the compression of gluten films on various electrolytes led to ordered structures. [less ▲]

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See detailInterfacial properties of oleosins and phospholipids from rapeseed for the stability of oil bodies in aqueous medium
Deleu, Magali ULg; Vaca-Medina, Guadalupe; Fabre, Jean-François et al

in Colloids and Surfaces B : Biointerfaces (2010), 80

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See detailInterfacial study of lipolysis inhibition by proteins.
Danthine, Sabine ULg; Blecker, Christophe ULg; Deroanne, Claude

Poster (2004, February 11)

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See detailInterference and negative priming in normal aging and in mild Alzheimer’s disease
Hogge, Michaël; Salmon, Eric ULg; Collette, Fabienne ULg

in Psychologica Belgica (2008), 48(1), 1-23

Most studies that have administered interference and negative priming tasks to patients with Alzheimer’s disease (AD) and healthy elderly subjects have demonstrated inhibitory dysfunction in AD patients ... [more ▼]

Most studies that have administered interference and negative priming tasks to patients with Alzheimer’s disease (AD) and healthy elderly subjects have demonstrated inhibitory dysfunction in AD patients, and mixed results in the elderly. In the present study, we re-explored these two effects in these populations by administering two tasks that allow assessing interference and negative priming effects. Results on both tasks showed (1) the presence of an interference effect in AD and elderly adults, that can be explained by cognitive slowing in the case of elderly controls; (2) the preservation of negative priming abilities in the two groups. These surprising results for AD patients were interpreted by proposing that AD patients have a preserved ability to suppress the representation of a distracter, but specific inhibitory deficits when they have to resolve a selection conflict at the stage of response production (i.e. when competing stimuli have been fully processed). [less ▲]

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See detailInterférence de l'adenylate kinase dans le dosage de la CK-MB dans la phase précoce de l'infarctus du myocarde
Chapelle, Jean-Paul ULg; Heusghem, C.; Buret, J.

Conference (1978, March 23)

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