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See detailNew efficient organocatalytic system for solvent-free chemical fixation of CO2 into epoxides
Panchireddy, Satyannarayana ULg; Gennen, Sandro ULg; Alves, Margot ULg et al

Poster (2015, September 11)

Due to concerns about global warming combined with the decrease of fossil resources, the chemical transformation of carbon dioxide (CO2) into added-value products has gained interest in both academic and ... [more ▼]

Due to concerns about global warming combined with the decrease of fossil resources, the chemical transformation of carbon dioxide (CO2) into added-value products has gained interest in both academic and industrial fields. To date, the chemical fixation of CO2 onto epoxides with the formation of cyclic carbonates (CC) is one of the most promising ways to valorise CO2 at an industrial scale. Indeed, CC are useful monomers for polycarbonate synthesis and they can react with primary amines to produce 2-hydroxyethylurethane. This reaction can be extrapolated to the synthesis of non-isocyanate polyurethanes (NIPUs) by a step growth polymerization between bifunctional CC and diamines. [less ▲]

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See detailInstitutional repositories: it’s a matter of sticks and carrots
Rentier, Bernard ULg

E-print/Working paper (2015)

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See detailIdentification et caractérisation des progéniteurs pancréatiques et des précurseurs endocrines durant l'embryogenèse chez le poisson-zèbre
Ghaye, Aurélie ULg

Doctoral thesis (2015)

Le diabète survient lorsque le nombre ou la fonction des cellules β, productrices d’insuline est affecté. Le nombre de personnes atteintes par cette maladie croît de manière impressionnante d’année en ... [more ▼]

Le diabète survient lorsque le nombre ou la fonction des cellules β, productrices d’insuline est affecté. Le nombre de personnes atteintes par cette maladie croît de manière impressionnante d’année en année. Bien qu’il puisse être contrôlé par des injections régulières d’insuline, ce traitement est contraignant, coûteux et ne permet pas d’éliminer toute une série d’effets secondaires chez le patient diabétique. Un des challenges à l’heure actuelle est de développer des stratégies qui permettraient de remplacer ces cellules. La régénération in vivo constitue une approche thérapeutique attrayante. Cependant, cette régénération est peu efficace chez les mammifères et un défi majeur consisterait à la stimuler. Contrairement aux mammifères, le poisson-zèbre (Danio rerio), est un modèle de choix pour étudier la régénération puisqu’il possède le remarquable pouvoir de régénérer les cellules β rapidement et efficacement après leur ablation ciblée. Néanmoins, il est important d’identifier et de caractériser les cellules pancréatiques qui donnent naissance aux cellules β afin de connaître l'ensemble des facteurs et voies de signalisation contrôlant leur formation. Le but de mon doctorat s’est inscrit dans cette démarche d’identification et de caractérisation des cellules progénitrices. Pour ce faire, nous avons généré deux lignées transgéniques qui nous ont permis de suivre le destin des cellules exprimant le facteur de transcription Nkx6.1 et Ascl1b. Par des expériences de traçage de lignée, nous avons montré que les cellules Nkx6.1+ marquent des progéniteurs pancréatiques qui donnent naissance à toutes les lignées pancréatiques alors que les cellules Ascl1b marquent des précurseurs endocrines qui ne donnent naissance qu’à la lignée endocrine. Nous avons aussi montré qu’au début du développement pancréatique, les deux facteurs sont exprimés dans les mêmes cellules pancréatiques puis se séparent rapidement. Cette ségrégation n’est pas la conséquence d’une répression mutuelle entre Ascl1b et Nkx6.1 mais est due à un effet opposé de la voie de signalisation Notch qui maintient l’expression de nkx6.1 et réprime l’expression d’ascl1b. [less ▲]

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See detailOsteopontin as a new target in glioblastoma progression and resistance to radiotherapy
Henry, Aurélie ULg; Bellahcene, Akeila ULg; Castronovo, Vincenzo ULg et al

Conference (2015, September 10)

Glioblastoma (GBM) is the most aggressive and common solid human brain tumor. Because of GBM heterogeneity, location and aggressiveness, none of the available treatment is curative. These treatments ... [more ▼]

Glioblastoma (GBM) is the most aggressive and common solid human brain tumor. Because of GBM heterogeneity, location and aggressiveness, none of the available treatment is curative. These treatments include maximal surgical resection, radiotherapy and concomitant or adjuvant chemotherapy with Temozolomide (TMZ). However, the prognosis of adult patients with GBM remains poor and the survival outcome after treatment does not exceed 15 months. Glioblastoma-composing cells have developed many strategies to counteract these current therapies. Among the wide hallmarks acquired to survive, osteopontin (OPN) ranks correlates with lower overall and disease-free/relapse-free survival in all tumors combined, as well in brain cancer. OPN expression is largely considered as a molecular cancer marker associated with poor prognosis for patients with cancer. Our preliminary works (Lamour V and Henry A, IJC 2015) have demonstrated the role of OPN in the tumorigenicity of glioblastoma cells and its importance in the maintenance of the stem charachters. Within the continuance of this work, our recent studies focused on the potential role of OPN in the resistance of glioblastoma cells to radiotherapy and its implication in the initiation of Double Strand Breaks (DSBs) repair mechanism. In this context, U251-MG and U87-MG cells were used to assess the role of OPN in the initiation of the DSBs repair mechanism after an exposure to gamma-irradiation (γ–IR). The transient transfection of both cell lines with siRNA directed against OPN shown a lower induction of γ–H2AX compared to control (irrelevant siRNA). The survival of U251-OPN depleted cells was also affected after an exposure to γ–IR (based on clonogenic assays). However, the sole depletion of OPN in U87 cells affected their survival (independently of the γ–IR). To prove that the secreted form of OPN is necessary to survive after γ–IR, conditionned medium of U87-shSCR clones (rich in OPN) was used to treat U87shOPN clones before an exposure to γ–IR. By immunofluorescence, we observed that the γ–H2AX staining was higher in U87 shOPN clones than when treated with their own conditionned medium (poor in OPN). Currently, we are investigating the in vivo implication of OPN in the initiation of DSBs repair mechanism after an exposure of mice to γ–IR (whole brain exposure). For this purpose, IPTG-inducible U87 shRNA clones (SCR and OPN) have been generated and validated for an orthotopic xenograft model in NOD-SCID mice. The survival after a radiotherapy of 10 Gy (2Gy per day for 5 days) will be assessed in OPN-positive and –negative tumor-bearing mice. Taken together, these datas suggest that OPN could represent an important pronostic factor for patient response to radiotherapy in the context of GBM. [less ▲]

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See detailDynamics of hybrid switching diffusions SIRS model
Settati, Adel; Lahrouz, Aadil; El Jarroudi, Mustapha et al

in Journal of Applied Mathematics and Computing (2015)

The main aim of this paper is to study the effect of the environmental noises in the asymptotic properties of a stochastic version of the classical SIRS epidemic model. The model studied here include ... [more ▼]

The main aim of this paper is to study the effect of the environmental noises in the asymptotic properties of a stochastic version of the classical SIRS epidemic model. The model studied here include white noise and telegraph noise modeled by Markovian switching. We obtained conditions for extinction both in probability one and in pth moment. We also established the persistence of disease under different conditions on the intensities of noises, the parameters of the model and the stationary distribution of the Markov chain. The highlight point of our work is that our conditions are sufficient and almost necessary for extinction and persistence of the epidemic. The presented results are demonstrated by numerical simulations. [less ▲]

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See detailNumerical simulations on embedded solids : integration of CAD and eXtended Finite Element Analysis
Duboeuf, Frédéric ULg; Béchet, Eric ULg

Conference (2015, September 10)

The aim of this communication is to propose a procedure in order to dissociate the geometric description of the field’s approximation within the extended finite element method (X-FEM) and with non ... [more ▼]

The aim of this communication is to propose a procedure in order to dissociate the geometric description of the field’s approximation within the extended finite element method (X-FEM) and with non-matching meshes. Implicit and explicit approaches are combined in order to represent with accuracy all the CAD entities regardless of their dimension. The choice of appropriate tools such as Level Sets technique allows to describe evolving interfaces with great flexibility. The design of a dedicated P1 functional space is achieved by decimating the traces of standard finite element (FE) shape functions, thanks to a new algorithm, especially when the problem domain is embedded in a space of a higher dimension. An analysis of the approximation properties of the P1 FE trace spaces on hyper-surfaces is available in the literature and applied for solving PDEs on closed surfaces without boundary. Dirichlet boundary conditions are applied using a convenient choice of stable Lagrange multiplier space, according to a new generalized algorithm. That extends the existing solutions to every combination of the space domain and boundary dimensions. In terms of solvers, the introduction of double Lagrange multipliers can be used to recover the positive definiteness of the bilinear form. This approach allows to treat any embedding, i.e. 1, 2, or 3D problems embedded in 2 or 3D background meshes. The possibility of applying the methodology to beams is investigated, with a potential application to through-thickness reinforced composites in a mixed-dimensional modelling framework. [less ▲]

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See detailChallenges for Scale-Up of Batch Phase Separation
Pfennig, Andreas ULg; Becker, Karsten; Bach, S. et al

Conference (2015, September 10)

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See detail1. Actualités en ravageurs - 3. Cécidomyie équestre : retour inattendu
Chavalle, Sandrine ULg

in Watillon, Bernard; Bodson, Bernard (Eds.) Livre Blanc Céréales (2015, September 10)

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See detail1. Actualités en ravageurs - 1. Saison 2015 : attaque et dégâts de cécidomyie orange du blé
Hautier, Louis; Chavalle, Sandrine ULg; De Proft, Michel

in Bodson, Bernard; Watillon, Bernard (Eds.) Livre Blanc Céréales (2015, September 10)

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See detail1. Actualités en ravageurs - 2. Variétés résistantes à la cécidomyie orange du blé : intérêt agronomique et méthode de caractérisation
Chavalle, Sandrine ULg; Jacquemin, Guillaume; De Proft, Michel

in Watillon, Bernard; Bodson, Bernard (Eds.) Livre Blanc Céréales (2015, September 10)

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See detail6. Protection intégrée des semis et des jeunes emblavures
Henriet, François; Chavalle, Sandrine ULg; Bataille, Charlotte et al

in Bodson, Bernard; Watillon, Bernard (Eds.) Livre Blanc Céréales (2015, September 10)

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See detailNewts skip aquatic life and forego reproduction in response to alien fish introduction
Winandy, Laurane ULg; Darnet, Elodie; Denoël, Mathieu ULg

Conference (2015, September 10)

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See detailLivre Blanc Céréales
Bodson, Bernard ULg; Watillon, Bernard ULg

Book published by Gembloux Agro Bio Tech (2015)

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See detail2. Implantation des cultures
Eylenbosch, Damien ULg; Meza Morales, Walter ULg; Monfort, Bruno et al

in Bodson, Bernard; Watillon, Bernard (Eds.) Livre Blanc Céréales (2015, September 10)

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See detail3. Variétés - 2. Escourgeon et orge d'hiver fourragers
Monfort, Bruno; Mahieu, Olivier; Jacquemin, Guillaume et al

in Bodson, Bernard; Watillon, Bernard (Eds.) Livre Blanc Céréales (2015, September 10)

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See detail3. Variétés - 1. Froment d'hiver
Meza Morales, Walter ULg; Eylenbosch, Damien ULg; Jacquemin, Guillaume et al

in Bodson, Bernard; Watillon, Bernard (Eds.) Livre Blanc Céréales (2015, September 10)

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See detailLivre Blanc Céréales
Sinnaeve, Georges; Gofflot, S.; Chandelier, anne et al

in Bodson, Bernard; Watillon, Bernard (Eds.) Livre Blanc Céréales (2015, September 10)

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See detailDegradation of p-nitrophenol and bacteria with TiO2 xerogels sensitized in situ with tetra(4-carboxyphenyl)porphyrins
Tasseroul, Ludivine ULg; Lambert, Stéphanie ULg; Eskenazi, David et al

Poster (2015, September 10)

Heterogeneous photocatalysis is widely studied for environmental applications as oxidative processes can completely destroy organic pollutants such as alkanes, pesticides, dyes, etc. and microorganisms ... [more ▼]

Heterogeneous photocatalysis is widely studied for environmental applications as oxidative processes can completely destroy organic pollutants such as alkanes, pesticides, dyes, etc. and microorganisms. The most used photocatalyst is the commercial TiO2 Degussa P25, which is composed of 80% anatase and 20% rutile and which is active when TiO2 is exposed to UV light ( < 380 nm). Recently, several studies have been performed to extend the light absorption range of TiO2 towards the visible range. In this study, TiO2-based materials doped with porphyrins, a widely used dye for the photosensibilization of TiO2, have been prepared using a sol-gel process. To stabilize the TiO2-dye interactions, free metal tetra(4-carboxyphenyl)porphyrin and nickel tetra(4-carboxyphenyl)porphyrin were introduced in situ into the TiO2 matrix during the sol-gel process rather than by grafting. Samples were thoroughly characterized by TEM, X-ray diffraction, FT-IR, DR-UV/Vis and their texture has been examined by nitrogen adsorption–desorption at 77 K. The photocatalytic activity for the degradation of p-nitrophenol and Escherichia coli and Lactobacillus rhamnosus bacteria cells in aqueous medium, under halogen lamp light have been evaluated in relation with the physico-chemical modifications induced by the doping. The low temperature vacuum drying protocol (150°C) used in the present study enabled to obtain porphyrin doped TiO2 xerogels with a high specific surface area, and containing nanoparticles composed of amorphous- and anatase-TiO2. Diffuse reflectance spectroscopy attest the presence of TCPPH2 and TCPPNi within the TiO2 matrix. In a first step, the photoactivity of the xerogels is tested for p-nitrophenol degradation. Results show that crystallinity and nature and concentration of porphyrin introduced in situ have major impact on the degradation performances. In a second step, the best xerogel for p-nitrophenol degradation has been used to degrade bacteria. This xerogel degrades E. coli and L. rhamnosus bacteria cells in less than 48 and 24 h respectively. The photocatalytic degradation of a pollutant is thus correlated to the degradation of bacteria since a xerogel doped with the TCPPNi degrades both p-nitrophenol, E. coli and L. rhamnosus. [less ▲]

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See detailSedimentary development and correlation of long-term off-reef to shallow-water Devonian carbonate records in Europe
Pas, Damien ULg

Doctoral thesis (2015)

The Devonian Period was characterized by extensive shallow-marine regions, with the largest carbonate platform development of the Phanerozoic Eon. The research carried out in this thesis integrates field ... [more ▼]

The Devonian Period was characterized by extensive shallow-marine regions, with the largest carbonate platform development of the Phanerozoic Eon. The research carried out in this thesis integrates field work, petrographic analysis, conodont biostratigraphy, elemental and carbon isotope geochemistry, magnetic susceptibility and magnetic hysteresis measurement. The aim, to better understand and characterize the environmental conditions that led to the development of three of the largest European Devonian carbonate platforms. This multi-disciplinary study also proposes to validate the use of magnetic susceptibility as a reliable tool for palaeoenvironmental reconstruction and long-distance correlation in marine carbonate. Fieldwork was conducted on four key sections of the European Pre-Mesozoic massifs: the Ardennes (La Thure and Fromelennes-Flohimont), the Rheinisches Schiefergebirge (Burgberg) and the Carnic Alps (Freikofel). The large quantity and in-depth analysis of rock samples and thin-sections has demonstrated the fascinating environmental diversity that shaped the carbonate platforms in the Rhenohecynian and Paleotethys oceans towards the mid-late Devonian times. The aforementioned analysis has enabled the development of reconstructed sedimentary models and large-scale shallowing-deepening histories for each section. New and published biostratigraphic data provided reliable age constraints for the foremost environmental changes evident in each of the sections. δ13C results from the Frasnian – Famennian boundary in the Burgberg and Freikofel sections have revealed Kellwasser events in limestone lithologies. Based on the analysis of ±1800 samples, a high-resolution magnetic susceptibility (MS) curve for each section has been developed, highlighting the strong link between the MS signatures and the syn-sedimentary parameters, such as carbonate productivity/sedimentation rate, water agitation and siliciclastic input. The comparison between MS and elemental geochemistry datasets has demonstrated the inherent-parallel link existing between the siliciclastic input proxies and the variation in MS signature in each of the sections. Magnetic hysteresis measurements have shown that ferromagnetic minerals such as magnetite control the MS signal. By comparing our data sets with published data we could confirm that our MS signal is remagnetized. However links between siliciclastic input proxies and MS, and between MS and environmental parameters have proven a relatively good preservation of the primary depositionally-induced MS signal. Finally, by integrating complete data and establishing a correlation chart including the four long-term MS curves, it is apparent that on a regional scale long-term MS trends can be correlated, as long as the evolution of the main depositional setting in the sections studied remains comparable. The significant impact of syn-sedimentary parameters on the final MS signature seems to obscure the imprint of parameters driving variations in continental erosion (e.g., climate, sea-level and tectonic variations) and therefore limiting the inter-regional correlations. This collaborative project on time-series analysis of long-term high-resolution MS records in the Dinant Syncline has revealed the imprint of astronomical parameters, giving rise to a more accurate estimate of the Givetian Stage’s duration. [less ▲]

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