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Peer Reviewed
See detailEnhancement of nuclear receptor transcriptional signalling.
Renkawitz, Rainer; Kaltschmidt, Christian; Leers, Joerg et al

in Journal of Steroid Biochemistry & Molecular Biology (1996), 56(1-6 Spec No), 39-45

Glucocorticoids and thyroid hormones induce complex responses in about every mammalian tissue. These effects are mediated by the transcription factor function of the corresponding nuclear receptors, which ... [more ▼]

Glucocorticoids and thyroid hormones induce complex responses in about every mammalian tissue. These effects are mediated by the transcription factor function of the corresponding nuclear receptors, which in most cases achieve the observed regulatory strength in synergy with other factors. Here we describe the functional interaction of the glucocorticoid receptor (GR) with liver-specific transcription factors, the functional synergy of GR with the thyroid hormone receptor (TR), the synergizing sub-domains of the TR, and finally the direct interaction of the GR with other proteins. [less ▲]

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See detailEnhancement of ray tracing method for radiative heat transfer with new isocell quasi-monte carlo technique and application to EUI space instrument
Jacques, Lionel ULg; Masset, Luc ULg; Kerschen, Gaëtan ULg

in Proceedings of the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, HEFAT2014 (2014, July)

Monte Carlo ray tracing method for thermal analysis. The rationale for this research is the speed-up of radiative heat transfer computation with the Finite Element Method, widely used in mechanical ... [more ▼]

Monte Carlo ray tracing method for thermal analysis. The rationale for this research is the speed-up of radiative heat transfer computation with the Finite Element Method, widely used in mechanical engineering especially for space structure design but not yet often for thermal analysis of these structures. Based on Nusselt’s analogy, the ray direction sampling is done by sampling the unit disc to derive the ray directions. Stratified sampling is applied to the unit disc that is divided into cells or strata into which random points are generated. The isocell method relies on cells that have the particularity of presenting almost the same area and shape. This enhances the uniformity of the generated quasi-random sequence of ray directions and leads to faster convergence. The isocell method is associated with different surface sampling to derive REFs. The method is benchmarked against ESARAD, the standard ray tracing engine of the thermal analysis software used in the European aerospace industry. Various geometries are used. In particular, one entrance baffle of the Extreme Ultraviolet Imager (EUI) instrument developed at the Centre Spatial de Liège in Belgium is presented. The EUI instrument of the Solar Orbiter European Space Agency mission and will be launched in a 0.28 perihelion orbit around the Sun in 2018. [less ▲]

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See detailEnhancement of ray tracing method for radiative heat transfer: application to EUI space instrument
Jacques, Lionel ULg; Masset, Luc ULg; Kerschen, Gaëtan ULg

in Proceedings of the 15th International Heat Transfer Conference, IHTC-15 (2014, August)

The finite element method (FEM) is widely used in mechanical engineering, in particular for space structure design. However, FEM is not yet often used for thermal engineering of space structures where the ... [more ▼]

The finite element method (FEM) is widely used in mechanical engineering, in particular for space structure design. However, FEM is not yet often used for thermal engineering of space structures where the lumped parameter method is still dominant. Radiative exchange factors (REFs), used to calculate radiative thermal exchanges in space, are usually computed through Monte Carlo ray tracing. Due to the large number of elements composing a FE model, the computation of the REFs is prohibitively expensive. The isocell method aims at reducing the computational effort of the REFs with FEM, by decreasing the number of rays required to achieve a given accuracy. Based on Nusselt’s analogy, the ray direction sampling is carried out by sampling the unit disc to derive the ray directions. The isocell method is a special case of stratified sampling. It divides the unit disc into cells of almost same area and shape from which random points are generated. This enhances the uniformity of the ray directions and leads to faster convergence. This isocell method is associated with different surface sampling to derive the REFs. The method is benchmarked against ESARAD, the standard thermal analysis ray tracing engine used in the European aerospace industry. One entrance baffle of the Extreme Ultraviolet Imager (EUI) instrument developedat the Centre Spatial de Liège in Belgium is used as benchmarking case. Solar Orbiter is an European Space Agency mission to be launched in a Sun-centered 0.28 perihelion orbit. [less ▲]

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See detailThe Enhancement of Secondary Succession by Western Lowland Gorillas (Gorilla gorilla gorilla) in a Moist Tropical Forest of Southeast Cameroon
Petre, Charles-Albert ULg; Haurez, Barbara ULg; Tagg, Nikki et al

in Folia Primatologica : International Journal of Primatology = Internationale Zeitschrift für Primatologie = Journal international de Primatologie (2013), 84

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See detailEnhancement of selectivity and resolution in the enantioseparation of uncharged compounds using mixtures of oppositely charged cyclodextrins in capillary electrophoresis.
Abushoffa, Adel M; Fillet, Marianne ULg; Servais, Anne-Catherine ULg et al

in Electrophoresis (2003), 24(3), 343-50

The enantiomeric separation of some nonsteroidal anti-inflammatory drugs (NSAIDs) was investigated in capillary electrophoresis (CE) using dual systems with mixtures of charged cyclodextrin (CD ... [more ▼]

The enantiomeric separation of some nonsteroidal anti-inflammatory drugs (NSAIDs) was investigated in capillary electrophoresis (CE) using dual systems with mixtures of charged cyclodextrin (CD) derivatives. A significant enhancement of selectivity and resolution could be achieved in the enantioseparation of these analytes in their uncharged form by the simultaneous addition of two oppositely charged CD derivatives to the background electrolyte. The combination of the single-isomer cationic CD, permethyl-6-monoamino-6-monodeoxy-beta-CD (PMMAbetaCD) and the single-isomer polyanionic CD, heptakis-6-sulfato-beta-cyclodextrin (HSbetaCD) in a pH 2.5 phosphoric acid-triethanolamine buffer, was designed and employed for the enantioseparation of profens. The improvement in selectivity and resolution can be attributed to the fact that the two CDs, which lead to independent and enantioselective complexation with the analyte enantiomers, have not only opposite effects on the electrophoretic mobility of these compounds but also opposite affinity patterns towards the enantiomers of these compounds. Binding constants for these enantiomers with each CD were determined using linear regression approach, in order to be able to predict the effect of the concentrations of the two CDs on enantiomeric selectivity and resolution in such dual systems. [less ▲]

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See detailEnhancement of steroid receptor-mediated transcription for the development of highly responsive bioassays
Willemsen, Philippe; Scippo, Marie-Louise ULg; Maghuin-Rogister, Guy ULg et al

in Analytical and Bioanalytical Chemistry (2005), 382(4), 894-905

We have previously generated several transformed human mammary cell lines for the detection of steroid receptor-mediated activities and used these cell lines to detect and characterize steroid hormone ... [more ▼]

We have previously generated several transformed human mammary cell lines for the detection of steroid receptor-mediated activities and used these cell lines to detect and characterize steroid hormone (ant)agonistic compounds. In this report, we describe the specific optimization procedures used to enhance receptor-mediated transcription through the human glucocorticoid, progesterone and androgen receptors, respectively. Sodium arsenite-induced chemical stress leads to a substantial and specific increase in the glucocorticold receptor-mediated transcription, resulting in maximal stimulations of more than 2000-fold by the agonist dexamethasone. Similarly, a combined treatment with forskolin (an activator of adenylate cyclase) and trichostatin A (an inhibitor of histone deacetylases) leads to a synergistic enhancement of progesterone or androgen stimulation, resulting in a maximal induction of more than 200-fold or about 100-fold, respectively. The enhanced responses to specific steroids are mediated by the corresponding nuclear receptor. We show that by using these enhanced transcriptional stimulation protocols, it is possible to detect lower amounts of steroid hormones without substantially affecting the relative biological activities of various agonists. Finally, the application of these enhanced reporter cell assays to real biological samples from meat-producing animals is evaluated, and some validation parameters are presented. [less ▲]

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See detailEnhancement of Tamoxifen-Induced E-Cadherin Function by Ca2+ Channel Antagonists in Human Breast Cancer Mcf7/6 Cells
Charlier, Corinne ULg; Bruyneel, E.; Lechanteur, Chantal ULg et al

in European Journal of Pharmacology (1996), 317(2-3), 413-6

Despite its intensive use in adjuvant breast cancer therapy for more than 30 years, the exact mechanisms of action of tamoxifen have not yet been fully characterized. Tamoxifen was recently shown to ... [more ▼]

Despite its intensive use in adjuvant breast cancer therapy for more than 30 years, the exact mechanisms of action of tamoxifen have not yet been fully characterized. Tamoxifen was recently shown to restore the E-cadherin function of human breast cancer MCF7/6 cells and to suppress their invasive phenotype. Because tamoxifen interacts with targets implicated in Ca2+ homeostasis, we explored the possibility that the restoration of E-cadherin function in MCF7/6 cells induced by this drug could be affected by Ca2+ modulators. Two different Ca2+ channel antagonists (verapamil and nifedipine) potentiated the effect of tamoxifen on E-cadherin function, as evaluated with a fast cell aggregation assay. These molecules decreased the tamoxifen concentration needed to restore the E-cadherin function from 10(-6) M to 10(-7) M. When incubated with a Ca2+ channel agonist, Bay K8644 (methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluoro-methylphenyl)- pyridine-5-carboxylate), the effect of tamoxifen on E-cadherin function was completely abolished. These results demonstrate that the restoration of the E-cadherin function induced by tamoxifen depends, at least in part, on a Ca2+ pathway, and support the evidence of an effect of tamoxifen on Ca(2+)-dependent mechanisms. Our data also suggest that Ca2+ channel modulators could make it possible to decrease the dose of tamoxifen administered to patients without reducing the therapeutic effects. [less ▲]

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See detailEnhancement of TCP over wired/wireless networks with packet loss classifiers inferred by supervised learning
El Khayat, Ibtissam; Geurts, Pierre ULg; Leduc, Guy ULg

in Wireless Networks (2010), 16(2), 273-290

TCP is suboptimal in heterogeneous wired/wireless networks because it reacts in the same way to losses due to congestion and losses due to link errors. In this paper, we propose to improve TCP performance ... [more ▼]

TCP is suboptimal in heterogeneous wired/wireless networks because it reacts in the same way to losses due to congestion and losses due to link errors. In this paper, we propose to improve TCP performance in wired/wireless networks by endowing it with a classifier that can distinguish packet loss causes. In contrast to other proposals we do not change TCP’s congestion control nor TCP’s error recovery. A packet loss whose cause is classified as link error will simply be ignored by TCP’s congestion control and recovered as usual, while a packet loss classified as congestion loss will trigger both mechanisms as usual. To build our classification algorithm, a database of pre-classified losses is gathered by simulating a large set of random network conditions, and classification models are automatically built from this database by using supervised learning methods. Several learning algorithms are compared for this task. Our simulations of different scenarios show that adding such a classifier to TCP can improve the throughput of TCP substantially in wired/wireless networks without compromizing TCP-friendliness in both wired and wireless environments. [less ▲]

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See detailEnhancement of the poly/mono growth rate ratio for BiCMOS application
Nguyen, Ngoc Duy ULg; Loo, Roger

Report (2008)

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See detailEnhancement of the power factor of [Bi1.68Ca2O4](RS)[CoO2](1.69) - Ag composites prepared by the spray-drying method
Rivas-Murias, B.; Muguerra, Hervé ULg; Traianidis, M. et al

in Solid State Sciences (2010), 12(8), 1490-1495

[Bi1.68Ca2O4](RS)[CoO2](1.69) (BCCO) sample and Ag-BCCO composites (with 10, 20 or 30 wt% Ag) have been prepared by the spray-drying technique and uniaxially/isostatically packed. Scanning electron ... [more ▼]

[Bi1.68Ca2O4](RS)[CoO2](1.69) (BCCO) sample and Ag-BCCO composites (with 10, 20 or 30 wt% Ag) have been prepared by the spray-drying technique and uniaxially/isostatically packed. Scanning electron microscopy reveals that the Ag particles are well distributed in the BCCO cobaltite matrix at low Ag contents. The Ag particles have an important effect on densification and grain orientation of the samples, with a direct impact on their electrical conductivity. The electrical conductivity is higher for the uniaxial samples and increases with the Ag content up to 20% in weight, while the Seebeck coefficient is hardly affected. These features induce an improvement of the power factor, reaching a maximum value of 2.2 mu W K-2 cm(-1) at similar to 1050 K for the uniaxial sample with 20 wt% Ag. Our results suggest that the spray-drying technique is a promising method to obtain composites with a well-dispersed secondary phase. (C) 2010 Elsevier Masson SAS. All rights reserved. [less ▲]

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See detailEnhancement of the relaxation of SiGe layers by He ion implantation using a delta-Si:C layer
Buca, D.; Goryll, M.; Holländer, B. et al

Conference (2007)

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See detailEnhancement of thermophillic anaerobic digestion of methane by metal nanoparticles encapsulated in porous silica
Al-Ahmad, Alaa Eddin ULg; Hiligsmann, Serge ULg; Lambert, Stéphanie ULg et al

Poster (2013, December 05)

Increased demand and progressive depletion of fossil fuels, and worldwide concerns about greenhouse gas emissions have resulted in the development of promising technologies for renewable energy production ... [more ▼]

Increased demand and progressive depletion of fossil fuels, and worldwide concerns about greenhouse gas emissions have resulted in the development of promising technologies for renewable energy production. Therefore, potential alternatives for energy generation are intensively studied. One option is the use of biomass feedstock for the production of biogas through anaerobic digestion. This process is a biochemical technological process for the treatment of a wide range of feedstocks (e.g. organic fraction of municipal waste, animal manure and slurry, agricultural crops, etc.) to produce methane-rich biogas which can be used in replacement of fossil fuels in both heat and power generation and as a vehicle fuel. However, there are critical issues, which need to be addressed to make the production of bio-methane techno-economically viable and ecologically acceptable. One of the most important issues is the effect of trace metals addition on anaerobic digestion. These metals can be stimulatory, inhibitory, or even toxic for biochemical reactions, depending on their concentrations. As reported in literature, Ni, Co and Fe are all involved in the methane production biochemical process and serve as cofactors in enzymes which are involved in the biochemistry of methane formation (Zandvoort et al., 2006). Recently, enormous interest has been focused on biological applications of metal nanoparticles NPs due to their small size, high specified surface and their great potential in application to many science fields. The most studied process concerns zero valent palladium and iron NPs improving anaerobic biodegradation of chlorinated hydrocarbons (Windt et al., 2005). Moreover, investigation carried out in our lab showed that iron NPs encapsulated in silicate matrix may enhance hydrogen production by Clostridium butyricum (Beckers et al., 2013). Nevertheless the influences of metal NPs on methane producing anaerobic digestion have seldom been investigated. The present work investigates the enhancement effect of seven different metal NPs on methane production during the thermophilic anaerobic digestion. NPs of Cu, Pd, Pt, Ni, Co, Ag and Fe encapsulated in porous silica (SiO2) to prevent their coagulation and agglomeration, were added at concentration of 10-5mol/L in batch test (125ml serum bottles containing 70mL culture medium with 5g/L acetate monohydrate as the sole carbon substrate. Nickel, cobalt and iron NPs improved methane production from acetate. To confirm the previous results, the NPs were tested at different concentrations (10-4, 10-5, and 10-6 mol/L) with starch and glucose substrates. The results show that the impact increases with the increase of NPs concentrations up to 10-4 mol/L. The modified Gompertz equation was applied to describe the effect of NPs on anaerobic digestion. According to this model, the kinetic of methane production was particularly affected by nanoparticles addition. The values of the maximum methane production rate MPR (ml/day) was significantly higher 72.5% with nickel NPs at a concentration of 10-4 mol/L than the control without NPs. [less ▲]

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See detailEnhancement of Total Electron Content monitoring using triple frequency GNSS data
Spits, Justine; Warnant, René ULg

Conference (2011, August 31)

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See detailEnhancement of transfection efficiency through rapid and noncovalent post-PEGylation of poly(dimethylaminoethyl methacrylate)/DNA complexes
Pirotton, S.; Muller, Caroline; Pantoustier, N. et al

in Pharmaceutical Research (2004), 21(8), 1471-1479

Purpose. The aim of this work was to develop a new strategy to introduce poly(ethylene glycol) (PEG) into methacrylate-based polymer/ DNA complexes in order to produce hemocompatible particles able to ... [more ▼]

Purpose. The aim of this work was to develop a new strategy to introduce poly(ethylene glycol) (PEG) into methacrylate-based polymer/ DNA complexes in order to produce hemocompatible particles able to transfect cells in the presence of serum. Methods. Atom transfer radical polymerization was used to synthesize a well-defined poly(2-(dimethylamino) ethyl methacrylate) homopolymer ( PDMAEMA) and a poly( 2-( dimethylamino) ethyl methacrylate-b-poly( ethylene glycol) alpha-methyl ether, omega-methacrylate) palm-tree-like copolymer (P(DMAEMA-b-MAPEG)). The complexes obtained by self assembly of the pCMVbeta plasmid and the polymers were used to transfect Cos-7 cells. Their physical properties - particle size and zeta potential - were characterized respectively by dynamic light scattering and electrophoretic mobility measurements. Ex vivo hemocompatibility was also determined. Results. The PDMAEMA/pCMVbeta complexes transfected Cos-7 cells exclusively in the absence of serum. Although the P(DMAEMA-b-MAPEG) copolymer had no transfection activity per se, the addition of the latter to pre-formed PDMAEMA/DNA complexes significantly enhanced the activity and allowed transfection even in the presence of serum. The presence of palm-tree - like copolymers also improved the hemocompatibility properties of the complexes. No effect on platelet counts was observed for P(DMAEMA-b-MAPEG)/ pCMVbeta complexes, whereas a decrease of platelets was clearly observed when blood cells were incubated with PDMAEMA/pCMVbeta complexes. Conclusions. Such a synergistic effect of noncovalent PEGylation of poly( amino methacrylate)/ DNA complexes allows a new and versatile approach to tune up transfection efficiency. [less ▲]

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See detailEnhancement of Tumorigenicity of Human Breast Adenocarcinoma Cells in Nude Mice by Matrigel and Fibroblasts
Noël, Agnès ULg; Gillet, Marie-Claire ULg; Purnell, G. et al

in British Journal of Cancer (1993), 68(5), 909-15

The failure of MCF7 cells to induce the formation of tumours after sub-cutaneous inoculation into athymic nude mice can be obviated by the simultaneous injection of an extract of basement membrane ... [more ▼]

The failure of MCF7 cells to induce the formation of tumours after sub-cutaneous inoculation into athymic nude mice can be obviated by the simultaneous injection of an extract of basement membrane proteins (matrigel). Tumour growth is promoted and the latency period is low (2 to 4 weeks). In the absence of matrigel, the simultaneous inoculation of fibroblasts and MCF7 cells also resulted in the development of tumours, but with a longer latency period (about 2 months). The tumorigenic synergy between matrigel and fibroblasts was evidenced by co-inoculating MCF7 cells MDA-MB 231 cells with fibroblasts and matrigel. This co-inoculation decreased the delay of appearance of the tumours and/or accelerated the tumour growth, depending upon the number of fibroblasts injected. Repeated injections of fibroblasts conditioned medium, at the site of inoculum of tumour cells also enhanced tumour growth, suggesting the involvement of soluble factors secreted by fibroblasts. Histologically, tumours induced by co-inoculation of tumour cells and fibroblasts contained more stromal structures including vimentin-positive cells, fibronectin and interstitial collagens. These data suggest that human tumours may be reconstituted and grown in athymic nude mice using basement membrane components and fibroblasts as inductors. [less ▲]

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Peer Reviewed
See detailEnhancement of Varicella-Zoster virus infection in cell lines expressing ORF4- or ORF62-encoded proteins
Schoonbroodt, Sonia; Piette, Jacques ULg; Baudoux, Laurence et al

in Journal of Medical Virology (1996), 49(4), 264-273

Varicella-Zoster virus (VZV) open reading frames 4 (ORF4) and 62 (ORF62) encode putative immediate-early proteins (ORF4p and ORF62p, respectively) which are strong transactivators of other VZV genes and ... [more ▼]

Varicella-Zoster virus (VZV) open reading frames 4 (ORF4) and 62 (ORF62) encode putative immediate-early proteins (ORF4p and ORF62p, respectively) which are strong transactivators of other VZV genes and are involved in the very early stages of viral infection. ORF4p and ORF62p transactivate immediate-early and early gene promoters but have little or no effect on late gene promoters. To investigate the effect of ORF4p or ORF62p overexpression on the viral replication cycle, we constructed Vero cell lines expressing those genes under the control of the human cytomegalovirus major immediate-early promoter. VZV OKA infection of these stably transformed cell lines was followed-up using VZV glycoprotein E (gE) antigen quantification and virus titration. Upon serial passaging of infection in these cell lines expressing functionally active ORF4p or ORF62p, a 5- to 10-fold increase in viral gE antigen production was observed. Viral titers also demonstrated a 2- to 5-fold increase in viral production in these transformed cell lines. These results emphasize the role that both ORF4p and ORF62p play in enhancing the VZV replicative cycle. (C) 1996 Wiley-Liss, Inc. [less ▲]

Detailed reference viewed: 15 (3 ULg)