References of "Blacher, Silvia"
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See detailConvective drying of wastewater sludges: Influence of air temperature, superficial velocity and humidity on the kinetics
Léonard, Angélique ULg; Blacher, Silvia ULg; Marchot, Pierre ULg et al

in Pakowski, Zdzislaw (Ed.) X Drying Symposium, Lodz, 17-19 September 2003 (2003, September)

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See detailUse of X-ray microtomography to determine internal moisture profiles during convective drying of deformable materials
Léonard, Angélique ULg; Blacher, Silvia ULg; Marchot, Pierre ULg et al

in Saravacos, G.; Maroulis, Z. B.; Krokida, M. (Eds.) et al Proceedings of the European Drying Symposium - EuDrying03 (2003, September)

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See detailMoisture profiles determination during convective drying using X-ray microtomography
Léonard, Angélique ULg; Blacher, Silvia ULg; Marchot, Pierre ULg et al

in Proceedings of the 3rd World Congress on Industrial Process Tomography, Banff, Canada (2003, September)

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See detailPreparation of macroporous biodegradable poly(L-lactide-co-epsilon-caprolactone) foams and characterization by mercury intrusion porosimetry, image analysis, and impedancy spectroscopy
Maquet, Véronique; Blacher, Silvia ULg; Pirard, René ULg et al

in Journal of Biomedical Materials Research (2003), 66A(2), 199-213

Two poly(L-lactide-co-epsilon-caprolactone) random copolymers containing 5 and 40 mol% of epsilon-CL, namely P(LA-co-CL5) and P(LA-co-CL40), respectively, have been made macroporous by freeze-drying ... [more ▼]

Two poly(L-lactide-co-epsilon-caprolactone) random copolymers containing 5 and 40 mol% of epsilon-CL, namely P(LA-co-CL5) and P(LA-co-CL40), respectively, have been made macroporous by freeze-drying solutions in dimethylcarbonate. Most of the freeze-dried foams, prepared by varying polymer concentration and cooling rate, exhibited two main pore populations: (1) longitudinally oriented tube-like macropores with diameters greater than or equal to100 mum, and (2) interconnected micropores (10-100 mum). Pore characteristics, including macropore density, mean diameter, and interdistance, as well as micropore density, area, and shape, were determined by image analysis of scanning electron micrographs in order to study the influence of processing and formulation parameters on foam structure and properties. The pore orientation and the 3-D texture also were studied by image analysis and impedance spectroscopy. In the case of the P(LA-co-CL5), the macropore diameter increased with the cooling rate while the micropore diameter decreased. The micropores also became more circular when the cooling rate was increased. The pore size and morphology of the P(LA-co-CL40) were quite unchanged by varying the cooling rate. All the other conditions being the same, the P(LA-co-CL5) foams were better organized than the P(LA-co-CL40) foams, and pore orientation was improved at the higher cooling rate. Pore size and morphology also can be controlled by changing the polymer concentration (Cp), as we showed by studying P(LA-co-CL5) foams prepared by freeze-drying solutions in the 1-10 w/v% Cp range. Macropore density, average diameter, and interdistance of P(LA-co-CL5) foams increased with Cp, but the micropore characteristics remained almost unchanged no matter the Cp. The reliability of the characterization methods has been discussed, with special attention to mercury intrusion porosimetry, which is used primarily for measurement of pore volume and pore size distribution. However, this technique is reported here as a destructive and unreliable method for the characterization of fragile P(LA-co-CL40) foams. This study shows that image analysis and impedance spectroscopy can give reliable information relative to the pore morphology and anisotropy of freeze-dried foams. [less ▲]

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See detailRestricted expression of membrane type 1-matrix metalloproteinase by myofibroblasts adjacent to human breast cancer cells
Bisson, C.; Blacher, Silvia ULg; Polette, M. et al

in International Journal of Cancer = Journal International du Cancer (2003), 105(1), 7-13

The membrane type-1 matrix metalloproteinase (MT1-MMP), a protease originally identified in breast carcinoma, is characterized by its capacity to activate other MMPs (MMP-2 and MMP-13) and to degrade ... [more ▼]

The membrane type-1 matrix metalloproteinase (MT1-MMP), a protease originally identified in breast carcinoma, is characterized by its capacity to activate other MMPs (MMP-2 and MMP-13) and to degrade extracellular matrix. Our study was undertaken to localize and identify the MT1-MMP expressing cells in human breast adenocarcinomas. A textural analysis of images obtained by immunohistochemistry and in situ hybridization showed precisely the co-expression of alpha smooth muscle actin (alphaSM actin) and MT1-MMP in myofibroblasts. MT1-MMP expression is confined to myofibroblasts in close contact with tumor cells. In sharp contrast, the expression of MMP-2 was more widely distributed in both alphaSM actin positive and negative cells close to and at distance from cancer cell clusters. Our in vitro observations are consistent with the higher level of MT1-MMP expression and of MMP-2 activation observed in alphaSM actin positive fibroblasts derived from breast tumors, as compared to normal breast fibroblasts. Collectively, these results implicate myofibroblasts as major producer of MT1-MMP in breast cancer and emphasize the importance of stromal-epithelial cell interactions in their progression. [less ▲]

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See detailImage analysis of the axonal ingrowth into poly(D,L-lactide) porous scaffolds in relation to the 3-D porous structure
Blacher, Silvia ULg; Maquet, Véronique; Luyckx, Françoise ULg et al

in Biomaterials (2003), 24(6), 1033-1040

Porous polymer scaffolds are promising materials for neural tissue engineering because they offer valuable three-dimensional (3D) supports for the in vitro and in vivo axonal growth and tissue expansion ... [more ▼]

Porous polymer scaffolds are promising materials for neural tissue engineering because they offer valuable three-dimensional (3D) supports for the in vitro and in vivo axonal growth and tissue expansion. At the time being, how the in vivo neuronal cell development depends on the scaffold 3-D architecture is unknown. Therefore, scanning electron micrographs of longitudinal sections of porous polylactide scaffolds and immunohistological sections of these scaffolds after implantation and neurofilament staining have been studied by image analysis. Pore orientation and axonal ingrowth have been investigated by spectral analysis on gray level SEM images. Binary image processing has been carried out and the binary images have been studied by spectral analysis in order to estimate the possible effect of the image noise on the real pattern. In addition to axonal orientation, density and length distribution of the regenerated axons into the polymer scaffold have been measured. Dependence of the axonal ingrowth on the 3D-polymer scaffold has been discussed on the basis of the collected data. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailStabilization of a cocontinuous phase morphology by a tapered diblock or triblock copolymer in polystyrene-rich low-density polvethylene/polstyrene blends
Harrats, Charef; Fayt, Roger; Jérôme, Robert ULg et al

in Journal of Polymer Science. Part B, Polymer Physics (2003), 41(2), 202-216

The stability against the thermal annealing of a cocontinuous two-phase morphology developed in polystyrene (PS)/low-density polyethylene (LDPE) blends containing 80 wt % PS was investigated. Blends ... [more ▼]

The stability against the thermal annealing of a cocontinuous two-phase morphology developed in polystyrene (PS)/low-density polyethylene (LDPE) blends containing 80 wt % PS was investigated. Blends containing 1, 5, and 10 wt % of a tapered diblock poly(styrene-block-hydrogenated butadiene) (P(S-b-hB)) or triblock poly(styrene-block-hydrogenated butadiene-block-styrene) (P(S-hB-S)) copolymer were melt-blended with roll-mill mixing equipment. The efficiency of each of the two copolymers in stabilizing against coalescence the cocontinuous morphology was examined. The tensile properties of the resulting blends, annealed and nonannealed, were also examined in relation to the morphology induced by thermal annealing. The phase morphology was studied by optical and scanning electron microscopy. With computer-aided image analysis, it was possible to obtain a measurable characteristic parameter to quantify the cocontinuous phase morphology. When it was necessary, the extraction of one phase with a selective solvent was performed. Although the observed differences were subtle, the tapered diblock exhibited a more efficient compatibilizing activity than the triblock copolymer, particularly at a low concentration of about 2 wt %. The superiority of the tapered diblock over the triblock might be due to its ability to quantitatively locate at the LDPE/PS interface and consequently form a more efficient barrier against the subsequent breakup of the elongated structures of the cocontinuous phase morphology. The tensile properties of the triblock-modified blends were more sensitive to thermal annealing than the tapered-modified ones. This deficiency was ascribed to the phase morphology coarsening of the dispersed polyethylene phase. [less ▲]

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See detailImage analysis characterization of multi-walled carbon nanotubes
Gommes, Cédric ULg; Blacher, Silvia ULg; Masenelli-Varlot, Karine et al

in Carbon (2003), 41(13), 2561-2572

An original image analysis method is presented to characterize multi-walled carbon nanotubes from transmission electron microscopy images. The analysis is performed in three steps: (i) image preprocessing ... [more ▼]

An original image analysis method is presented to characterize multi-walled carbon nanotubes from transmission electron microscopy images. The analysis is performed in three steps: (i) image preprocessing in order to isolate the nanotubes from the background, (ii) image segmentation, aiming at keeping only the measurable sections of nanotubes, and finally (iii) tube characteristics measurement. The measurement is based on a Lambert-like electron absorption law and is performed on the original gray level image itself. Two geometrical and one physical characteristics are determined for each tube, namely, its outer and inner radius and a linear electron absorption coefficient. The method is illustrated by comparing a pristine and an annealed carbon nanotube samples. The compaction of the tube walls during annealing is shown to result from a lowering of the external radius while the inner radius is left unchanged. (C) 2003 Elsevier Ltd. All rights reserved. [less ▲]

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See detailHydrodynamique et morphologie d'une bactérie filamenteuse dans un fermenteur à cuve agitée
Groslambert, Sylvie ULg; Blacher, Silvia ULg; Crine, Michel ULg

in Tribune de l'Eau (La) (2003), 56(622), 58-64

Afin d'étudier l'influence de l'hydrodynamique sur une bactérie filamenteuse, Actinomadura R39, nous l'avons cultivée dans un fermenteur de laboratoire de 5 litres à cuve agitée en faisant varier les ... [more ▼]

Afin d'étudier l'influence de l'hydrodynamique sur une bactérie filamenteuse, Actinomadura R39, nous l'avons cultivée dans un fermenteur de laboratoire de 5 litres à cuve agitée en faisant varier les conditions d'agitation. Les variables sont la vitesse de rotation et le type de mobile utilisé: turbines Rushton ou Intermig. Les deux mobiles se distinguent par leur géométrie et par les schémas d'écoulement qu'ils induisent dans la cuve. L'influence de l'hydrodynamique sur Actinomadura R39 est quantifiée par l'évolution de sa morphologie. Cette dernière est estimée par analyse d'images sur des échantillons prélevés lors des cultures. Parallèlement, nous avons caractérisé l'hydrodynamique du fermenteur dans un milieu artificiel reproduisant la rhéologie des fermentations en mesurant la puissance dissipée et en effectuant des essais de traceurs. Ces derniers sont utilisés pour la modélisation du fermenteur par un modèle compartimenté et le calcul du temps de mélange. Nous avons pu ainsi mettre en relation les modifications de la morphologie et des grandeurs caractérisant les écoulements dans le fermenteur. L'existence de corrélations entre les paramètres du modèle et la morphologie a également permis une validation de la signification physique de ce modèle. [less ▲]

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See detailQuantification of Angiogenesis of Embryonic Implantation Site by Image Analysis
Le Maire, Sophie; Blacher, Silvia ULg; Frankenne, F. et al

Conference (2003)

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See detailMultiscale texture characterization of wastewater sludges dried in a convective rig
Léonard, Angélique ULg; Blacher, Silvia ULg; Pirard, René ULg et al

in Drying Technology (2003), 21(8), 1507-1526

Secondary sludges from two different wastewater treatment plants are conditioned and dewatered in the same way before drying in a lab-scale convective rig at the same operating conditions. Several ... [more ▼]

Secondary sludges from two different wastewater treatment plants are conditioned and dewatered in the same way before drying in a lab-scale convective rig at the same operating conditions. Several techniques are used to characterize the texture of the dried materials over a wide range of scales from nm up to mm. Texture and porosity of the dried products are studied by SEM imaging, nitrogen absorption isotherms (0.5 < d(p) < 50 nm), mercury porosimetry (7.5 nm < d(p) < 150 mum) and X-ray microtomography (spatial resolution= 41 mum). The image analysis of cross-sections reconstructed by microtomography also allows following shrinkage and textural evolution during drying. [less ▲]

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See detailQuantification of angiogenesis on the rat aortic ring assay.
Blacher, Silvia ULg; Devy, L.; Noël, Agnès ULg et al

in Image Analysis and Stereology (2003), 22

Image analysis is used to quantify angiogenesis on the rat aortic ring model. This technique allows to determine: (1) the aortic ring area and factor shape; (2) the number of microvessels, the total ... [more ▼]

Image analysis is used to quantify angiogenesis on the rat aortic ring model. This technique allows to determine: (1) the aortic ring area and factor shape; (2) the number of microvessels, the total number of branching, the maximal microvessel length and the number of microvessels in function of the distance to the aortic ring; (3) the total number of isolated fibroblast-like cells and the number of fibroblast-like cells in function of the distance to the aortic ring. We show that this method is suitable to quantify spontaneous angiogenesis as well as to analyse a complex microvascular network induced by vascular endothelial growth factor (VEGF). [less ▲]

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See detailMouse Aortic Ring Assay: A New Approach of the Molecular Genetics of Angiogenesis
Masson, Véronique ULg; Devy, L.; Grignet-Debrus, Christine ULg et al

in Biological Procedures Online (2002), 4

Angiogenesis, a key step in many physiological and pathological processes, involves proteolysis of the extracellular matrix. To study the role of two enzymatic families, serine-proteases and matrix ... [more ▼]

Angiogenesis, a key step in many physiological and pathological processes, involves proteolysis of the extracellular matrix. To study the role of two enzymatic families, serine-proteases and matrix metalloproteases in angiogenesis, we have adapted to the mouse, the aortic ring assay initially developed in the rat. The use of deficient mice allowed us to demonstrate that PAI-1 is essential for angiogenesis while the absence of an MMP, MMP-11, did not affect vessel sprouting. We report here that this model is attractive to elucidate the cellular and molecular mechanisms of angiogenesis, to identify, characterise or screen "pro- or anti-angiogenic agents that could be used for the treatment of angiogenesis-dependent diseases. Approaches include using recombinant proteins, synthetic molecules and adenovirus-mediated gene transfer. [less ▲]

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See detailTexture characterisation of ultramacroporous materials using non-destructive methods
Blacher, Silvia ULg; Maquet, Véronique; Léonard, Angélique ULg et al

Conference (2002, May)

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