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See detailPolymerization of ortho-Substituted Phenylacetylenes with Well-Defined Ruthenium-Alkylidene Catalysts and Related Metathesis Initiators
Katsumata, T.; Shiotsuki, M.; Sanda, F. et al

in Macromolecular Chemistry And Physics (2009), 210(22), 1891-1902

The polymerization of (2-isopropoxyphenyl)acetylene was investigated using a wide range of well-defined ruthenium-alkylidene complexes and related olefin metathesis initiators. In view of its superior ... [more ▼]

The polymerization of (2-isopropoxyphenyl)acetylene was investigated using a wide range of well-defined ruthenium-alkylidene complexes and related olefin metathesis initiators. In view of its superior activity, the second generation Hoveyda-Grubbs catalyst was singled out for further studies. Only phenylacetylenes ortho-substituted with alkoxy, ester, fluoro, and silyl groups afforded polymers with moderate molecular weights. They were characterized by various analytical techniques, and their properties were pared with those of samples prepared using Rh and W initiators. The Ru-based polymers possessed high trans contents and took a helical conformation with predominantly one-handed screw sense when chiral side-chains were present. [less ▲]

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See detailPolymerization of β-butyrolactone initiated with Al(OiPr)3
Kurcok, Piotr; Dubois, Philippe ULg; Jérôme, Robert ULg

in Polymer International (1996), 41(4), 479-485

Polymerization of gamma-butyrolactone has been studied in toluene with Al(OiPr)3 as an initiator. The ring-opening polyaddition proceeds through a coordination-insertion mechanism at a very low rate. Well ... [more ▼]

Polymerization of gamma-butyrolactone has been studied in toluene with Al(OiPr)3 as an initiator. The ring-opening polyaddition proceeds through a coordination-insertion mechanism at a very low rate. Well defined -isopropylester, -hydroxy poly(-butyrolactone)s (PBL) are formed with a narrow molecular weight distribution at low monomer-to-initiator molar ratios, When this ratio is higher (ca. 170), a competition occurs between propagation and side reactions, i.e. elimination, inter- and intra-molecular transesterifications and thermal degradation, which is responsible for a loss of control of the PBL molecular charcteristics. The addition of a Lewis base (1 equivalent of nicotine/Al) to the Al-alkoxide initiator has no significant effect on the polymerization rate, although the chain microstructure is deeply affected since predominantly syndiotactic PBL chains are formed (63% syndio-diads) in contrast to a completely atactic polymer in the absence of nicotine. [less ▲]

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See detailPolymerization-filled composites and nanocomposites by coordination catalysis
Dubois, Philippe ULg; Alexandre, Michaël ULg; Jérôme, Robert ULg

in Macromolecular Symposia (2003), 194

Polyolefinic microcomposites and layered silicate nanocomposites were prepared by the in-situ polymerization of ethylene (and alpha-olefin) via the so-called polymerization-filling technique. Various ... [more ▼]

Polyolefinic microcomposites and layered silicate nanocomposites were prepared by the in-situ polymerization of ethylene (and alpha-olefin) via the so-called polymerization-filling technique. Various tillers with either basic, acidic, metallic or carbonaceous surface, as well as non-modified clays such as montmorillonite and hectorite, were first treated by trimethylaluminum-depleted methylaluminoxane before being contacted by a titanium or zirconium-based metallocene catalyst. The (nano)composite was formed by addition and polymerization of ethylene (and alpha-olefin). This technique makes possible the complete encapsulation of every filler particle within the (co)polyolefinic matrix ranging from thermoplastics to elastomers. The so-obtained (nano)composites, often coined as "homogeneous" (nano)composites, exhibit improved mechanical properties; as compared to more conventional melt blends for a same filler content. [less ▲]

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See detailPolymerization-filled composites prepared with highly active filler-supported Al/Ti/Mg catalysts. I. Synthesis of homogeneous polyethylene-based composites
Hindryckx, François; Dubois, Philippe; Jérôme, Robert ULg et al

in Journal of Applied Polymer Science (1997), 64(3), 423-438

When it is attached onto the surface of an inorganic filler (kaolin, barite), the (BuO)4Ti/BuMgOct/EtAlCl2/Et3Al system is a highly efficient and very promising catalyst for the production of high ... [more ▼]

When it is attached onto the surface of an inorganic filler (kaolin, barite), the (BuO)4Ti/BuMgOct/EtAlCl2/Et3Al system is a highly efficient and very promising catalyst for the production of high-performance polyethylene-based composites. The surface concentration of the hydroxyl groups, the Al/Ti/Mg ratio, and the purity of the reagents have a major effect on the catalyst efficiency and molecular weight, crystallinity, and physico-mechanical properties of the final composite. Under ca. 4 bar partial pressure of ethylene in heptane at 60°C, the optimum Al/Ti/Mg catalyst composition is 120/0.75/10, the efficiency of which is as high as 300 kgPE/(gTi × h) in the presence of kaolin particles (Satintone W/W). The effect of transfer agents, such as hydrogen and 1-octene, and purity of the -olefin has been investigated. Actually, the catalyst efficiency is increased in the presence of both hydrogen and octene. Scanning Electron Microscopy (SEM) has shown that the ethylene was polymerized from the filler surface. Special attention has also been paid to the effect of size, density, and surface acidity of the filler particles. The surface of basic filler has to be treated in order to become an efficient catalyst carrier. [less ▲]

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See detailPolymerization-filled composites prepared with highly active filler-supported Al/Ti/Mg catalysts. II. Properties of homogeneous polyethylene-based
Hindryckx, François; Dubois, Philippe; Jérôme, Robert ULg et al

in Journal of Applied Polymer Science (1997), 64(3), 439-454

Polyethylene-based composites have been prepared by ethylene polymerization with a Al/Ti/Mg catalyst previously deposited on the surface of kaolin (Satintone W/W and Satintone 5) or barite.(1) Molecular ... [more ▼]

Polyethylene-based composites have been prepared by ethylene polymerization with a Al/Ti/Mg catalyst previously deposited on the surface of kaolin (Satintone W/W and Satintone 5) or barite.(1) Molecular weight (M(w)) of the polyethylene matrix has been estimated from melt viscosity under steady shear flow and compared to the value measured by size exclusion chromatography. Tensile stress and strain, Young modulus, and impact energy have been measured in relation to the matrix molecular weight and the filler content. The effect of the main polymerization parameters, such as the Al/Ti/Mg composition, the addition of a transfer agent, e.g., an alpha-olefin or hydrogen, have also been investigated. These tensile and impact properties have been compared to composites of the same composition but prepared by melt blending of the filler and the preformed polyolefin. As a rule, the polymerization-filled composites have an improved mechanical strength compared to the analogues prepared by melt blending. [less ▲]

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See detailPolymerization-filling technique: an efficient way to improve the mechanical properties of polyethylene composites
Alexandre, Michaël ULg; Martin, Eric; Dubois, Philippe ULg et al

in Chemistry of Materials (2001), 13(2), 236-237

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See detailPolymers in modern ophthalmic implants—Historical background and recent advances
Bozukova, Dimitriya; Pagnoulle, Christophe; Jérôme, Robert ULg et al

in Materials Science & Engineering : R (2010), 69(6), 63-83

Cataract surgery is the most frequently performed surgical intervention, pursued by replacement of the opacified natural lens by a polymeric intraocular lens (IOL). This paper, based on an exhaustive ... [more ▼]

Cataract surgery is the most frequently performed surgical intervention, pursued by replacement of the opacified natural lens by a polymeric intraocular lens (IOL). This paper, based on an exhaustive number of scientific references, provides a brief simplified discussion of the surgical advances for cataract treatment, and is mainly focused on the process of IOL discovery, engineering and development. The performances of the polymer materials, used for the IOLs fabrication are discussed in a comparative way, and their properties, such as handling during surgery, biocompatibility, rate of some post-surgical complications (e.g. Posterior Capsular Opacification) and optical properties, are considered. Special attention is paid on the basic scientific approaches for engineering and modification of the IOL surface and bulk properties. Polymer coating techniques like ‘grafting onto’ and ‘grafting from’ are discussed and exemplified by a variety of coating compositions and performances. In another part of the review, modification techniques concerning optimization of the bulk properties of the polymer lens are also discussed and synthetic approaches such as copolymerization and nanocomposite formation are considered. A perspective aspect of this discussion concerns improvement of the performance of the main polymer by the incorporation of in situ formed or preformed nanoparticles. The most attractive perspectives concerning the improvement of the IOL properties by chemical modification approaches are described. [less ▲]

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See detailPolymorphic miRNA-mediated gene regulation: contribution to phenotypic variation and disease.
Georges, Michel ULg; Coppieters, Wouter ULg; Charlier, Carole ULg

in Current opinion in genetics & development (2007), 17(3), 166-76

The expression of at least a third of mammalian genes is post-transcriptionally fine-tuned by approximately 1000 microRNAs (miRNAs), assisted by the RNA silencing machinery, comprising tens of components ... [more ▼]

The expression of at least a third of mammalian genes is post-transcriptionally fine-tuned by approximately 1000 microRNAs (miRNAs), assisted by the RNA silencing machinery, comprising tens of components. Polymorphisms and mutations in the corresponding sequence space (machinery, miRNA precursors and target sites) are likely to make a significant contribution to phenotypic variation, including disease susceptibility. Here we review basic miRNA biology in animals, survey the available evidence for DNA sequence polymorphisms affecting miRNA-mediated gene regulation and thus phenotype, and discuss their possible importance in the determination of complex traits. [less ▲]

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See detailPolymorphic miRNA-target interactions : A Novel Source of Phenotypic Variation
Georges, Michel ULg; Clop, Alex; Marcq, Fabienne ULg et al

in Cold Spring Harbor Symposia on Quantitative Biology (2006, June), 71

Studying the muscular hypertrophy of Texel sheep by forward genetics, we have identified an A-to-G transition in the 3'UTRof the GDF8 gene that reveals an illegitimate target site for microRNAs miR-1 and ... [more ▼]

Studying the muscular hypertrophy of Texel sheep by forward genetics, we have identified an A-to-G transition in the 3'UTRof the GDF8 gene that reveals an illegitimate target site for microRNAs miR-1 and miR-206 that are highly expressed in skeletal muscle. This causes the down-regulation of this muscle-specific chalone and hence contributes to the muscular hypertrophyof Texel sheep. We demonstrate that polymorphisms which alter the content of putative miRNA target sites are commonin human and mice, and provide evidence that both conserved and nonconserved target sites are selectively constrained. Wespeculate that these polymorphisms might be important mediators of phenotypic variation including disease. To facilitatestudies along those lines, we have constructed a database (www.patrocles.org) listing putative polymorphic microRNA–targetinteractions. [less ▲]

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See detailA polymorphic satellite sequence maps to the pericentric region of the bovine Y chromosome
Perret, J.; Shia, Y.; Fries, R. et al

in Genomics (1990), 6(3), 482-490

Exploiting a serendipitously observed bovine male-specific signal, generated by the mouse pSP64.2.5EI minisatellite probe, we have cloned a bovine (Bos taurus) Y-specific sequence: btDYZ-1. This sequence ... [more ▼]

Exploiting a serendipitously observed bovine male-specific signal, generated by the mouse pSP64.2.5EI minisatellite probe, we have cloned a bovine (Bos taurus) Y-specific sequence: btDYZ-1. This sequence is composed of 60 tandem repetitions of a motif consisting of two parts: a 40-bp-long unit, showing a mean divergence of 27% between repeats, separated from the next repeat by a TG-rich stretch varying in length between 12 and 63 bp. The number of copies of this repeated motif has been estimated at 6 X 10(4) per male genome. As a consequence, the corresponding satellite, DYZ-1, might represent approximately 1/20 of the bovine Y chromosome. btDYZ-1 has been mapped by in situ hybridization to the pericentric region of the Y chromosome. It is characterized by a substantial genetic polymorphism and has been shown to be conserved within the Bos and Bison genera of the Bovinae subfamily. This sequence is being used to develop a sexing procedure for bovine preimplantation embryos based on the polymerase chain reaction. [less ▲]

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See detailPolymorphism in IgG Fc receptor gene FCGR3A and response to infliximab in Crohn's disease: a subanalysis of the ACCENT I study.
Louis, Edouard ULg; Watier, Herve E; Schreiber, Stefan et al

in Pharmacogenetics and Genomics (2006), 16(12), 911-4

Recently, it has been shown that FCGR3A-158 gene polymorphism is associated with biological and possibly clinical response to infliximab in Crohn's disease. We further assessed this association in a ... [more ▼]

Recently, it has been shown that FCGR3A-158 gene polymorphism is associated with biological and possibly clinical response to infliximab in Crohn's disease. We further assessed this association in a subset of 344 patients from the large and well-defined cohort of 573 patients with Crohn's disease from the ACCENT I study. No association could be observed between FCGR3A-158 gene polymorphism and the clinical response to infliximab, which was primarily defined as a decrease of >or=70 points in the Crohn's disease activity index or clinical remission (Crohn's disease activity index <150). We did, however, confirm a trend towards a greater decrease in C-reactive protein after infliximab in V/V homozygotes as compared with V/F heterozygotes and F/F homozygotes (-79.4, -76.5, and -64.3%, respectively, at week 6; P=0.085; one-tailed P=0.043). This finding has no immediate clinical impact but may enhance the understanding of the complex mechanisms of action of anti-tumor necrosis factor agents in Crohn's disease. [less ▲]

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See detailPolymorphism in PERIOD3 predicts fMRI-assessed inter-individual differences in the effects of sleep deprivation
Vandewalle, Gilles ULg; Archer, Simon; Wuillaume, Catherine et al

in Journal of Sleep Research (2008), 17(Suppl. 1),

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See detailPolymorphism, an extension of binary opening
Van Droogenbroeck, Marc ULg

in Second international conference on Mathematical Morphology and its Applications to Image Processing, Proceedings (1994, September)

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See detailPolymorphisme au niveau du récepteur de l’hormone de croissance et production laitière
Renaville, Robert ULg; Gengler, Nicolas ULg; Prandi, Alberto et al

in 2° Carrefour des Productions Animales (1997)

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See detailPolymorphisme du syndrome d'activite continue des fibres musculaires Relation possible avec la choree fibrillaire de Morvan.
Delwaide, P.; Figiel, C.; Schoenen, Jean ULg et al

in Revue Neurologique (1979), 135(8-9), 615-24

Two cases presenting the main features of the continuous muscle activity syndrome (neuromyotonia) are reported. The clinical particularities between the two patients are under lined. The second case is ... [more ▼]

Two cases presenting the main features of the continuous muscle activity syndrome (neuromyotonia) are reported. The clinical particularities between the two patients are under lined. The second case is special because of its acute and reversible evolution and the possible role of gold salts in its etiology. This latter point suggests Morvan's fibrillary chorea. The possible relationships between the two syndrome are discussed. [less ▲]

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See detailPolymorphisms at the Five Exons of the Growth Hormone Gene in the Algarvia Goat. Possible Association with Milk Traits
Malveiro, E.; Pereirab, M.; Marques, P. X. et al

in Small animal research (2001), 41

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See detailPolymorphisms in innate immunity genes predispose to bacteremia and death in the medical intensive care unit
Henckaerts, L.; Nielsen, K. R.; Steffensen, R. et al

in Critical Care Medicine (2009), 37(1), 192-2011-3

OBJECTIVE: Critically ill patients are at risk of sepsis, organ failure, and death. Studying the impact of genetic determinants may improve our understanding of the pathophysiology and allow ... [more ▼]

OBJECTIVE: Critically ill patients are at risk of sepsis, organ failure, and death. Studying the impact of genetic determinants may improve our understanding of the pathophysiology and allow identification of patients who would benefit from specific treatments. Our aim was to study the influence of single nucleotide polymorphisms in selected genes involved in innate immunity on the development of bacteremia or risk of death in patients admitted to a medical intensive care unit. DESIGN, SETTING, AND PATIENTS: DNA was available from 774 medical intensive care unit patients. We selected 31 single nucleotide polymorphisms in 14 genes involved in host innate immune defense. Serum levels of MASP2 and chemotactic capacity, phagocytosis, and killing capacity of monocytes at admission were quantified. Univariate Kaplan-Meier estimates with log-rank analysis and multivariate logistic regression were performed. Bootstrap resampling technique and ten-fold cross-validation were used to assess replication stability, prognostic importance of the variables, and repeatability of the final regression model. MAIN RESULTS: Patients with at least one NOD2 variant were shown to have a reduced phagocytosis by monocytes (p = 0.03) and a higher risk of bacteremia than wild-type patients (p = 0.02). The NOD2/TLR4 combination was associated with bacteremia using survival analyses (time to bacteremia development, log-rank p < 0.0001), univariate regression (p = 0.0003), and multivariate regression analysis (odds ratio [OR] 4.26, 95% confidence interval [CI] 1.85-9.81; p = 0.0006). Similarly, the same combination was associated with hospital mortality using survival analysis (log-rank p = 0.03), univariate regression (p = 0.02), and multivariate regression analysis (OR 2.27, 95% CI 1.09-4.74; p = 0.03). Also variants in the MASP2 gene were significantly associated with hospital mortality (survival analysis log-rank-p = 0.003; univariate regression p = 0.02; multivariate regression analysis OR 2.35, 95% CI 1.38-3.99; p = 0.002). CONCLUSIONS: Functional polymorphisms in genes involved in innate immunity predispose to severe infections and death, and may become part of a risk model, allowing identification of patients at risk, who could benefit from early introduction of specific preventive or therapeutic interventions. [less ▲]

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