References of "2009"
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See detailA comparison of different types of commercial FBP and OSEM SPECT reconstruction software
Seret, Alain ULg; Forthomme, Julien

in Journal of Nuclear Medicine Technology (2009), 37(3), 179-187

This study aimed at comparing the performance of filtered backprojection (FBP) and ordered subset expectation maximisation (OSEM) reconstruction algorithms available in several types of commercial SPECT ... [more ▼]

This study aimed at comparing the performance of filtered backprojection (FBP) and ordered subset expectation maximisation (OSEM) reconstruction algorithms available in several types of commercial SPECT software. Methods: Numerical simulations of SPECT acquisitions of two phantoms were used: the NEMA line used for the assessment of SPECT resolution and a phantom with uniform, hot and cold rod compartments. The investigated types of software were: General Electric Xeleris and Vision, Philips Jetstream, Segami Mirage, Siemens eSoft and Icon, and Sopha Medical Vision XT. For FBP, no filtering and filtering of the projections with either Butterworth (order 3 or 6) or Hanning filters at various cut-off frequencies were considered. For OSEM, the number of subsets was 1, 4, 8, or 16 and the number of iterations was chosen to obtain a product number of iterations times the number of subsets equal to 16, 32, 48 or 64. The line phantom enabled us to obtain the reconstructed central, radial and tangential full-widths at half-maximum. The uniform compartment of the second phantom delivered the mean reconstructed pixel values and the standard deviations from which the coefficients of variation were calculated. Hot and cold contrasts were obtained from its rod compartments. Results: For FBP, full-widths at half-maximum, mean pixel values, coefficients of variation and contrasts were almost software independent. The only exceptions were: smaller (0.5 mm) full-widths at half-maximum for Vision, larger mean pixel values for Vision and XT, and better contrasts for Vision and XT for some filtering conditions. For OSEM, full-widths at half-maximum differed between the different types of software from 0.1 to 2.5 mm but these were almost independent of the number of subsets or iterations. There was a high dependence of the mean pixel value on the type of software used and a moderate dependence of the coefficient of variation. The contrasts were almost software independent. Mean pixel value varied greatly with the number of iterations for Mirage and Vision, and the coefficient of variation increased with the number of iterations for all types of software. The mean pixel value, the coefficient of variation and the contrasts were almost constant for a fixed product number of iterations times the number of subsets, whatever the number of subsets or iterations. Conclusion: Most of the types of software were equivalent for FBP or OSEM reconstruction. However, a few differences were observed for some types of software and should be considered when using them. [less ▲]

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See detailLes contrats commerciaux
Bublot, Jean ULg

in Guide des contrats et lettres types (2009)

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See detailModelling the early phases of bone regeneration around an endosseous oral implant
Amor, N.; Geris, Liesbet ULg; Vander Sloten, J. et al

in Computer Methods in Biomechanics & Biomedical Engineering (2009), 12(4), 459-468

The objective of this study was to see whether a mathematical model of fracture healing was able to mimic bone formation around an unloaded screw-shaped titanium implant as it is well-believed that both ... [more ▼]

The objective of this study was to see whether a mathematical model of fracture healing was able to mimic bone formation around an unloaded screw-shaped titanium implant as it is well-believed that both processes exhibit many biological similarities. This model describes the spatio-temporal evolution of cellular activities, ranging from mesenchymal stem cell migration, proliferation, differentiation to bone formation, which are initiated and regulated by the growth factors present at the peri-implant site. For the simulations, a finite volume code was used and adequate initial and boundary conditions were applied. Two sets of analyses have been performed, in which either initial and boundary condition or model parameter values were changed with respect to the fracture healing model parameter values. For a number of combinations, the spatio-temporal evolution of bone density was well-predicted. However reducing cell proliferation rate and increasing osteoblast differentiation and osteogenic growth factor synthesis rates, the simulation results were in agreement with the experimental data. [less ▲]

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See detailPierre-Augustin Guys à Constantinople: un regard méconnu sur le Levant à la fin du XVIIIe siècle
Famerie, Etienne ULg

in Droixhe, Daniel; Collart, Muriel (Eds.) L'"Esprit des journaux": un périodique européen au XVIIIe siècle (2009)

Guys' original approach and description of the contemporaneous Greek people, breaking a new ground in favour of the philhellenic movement in the end of 18th century

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See detailCross-reactive T cell responses in HIV CRF01_AE and B'-infected intravenous drug users: implications for superinfection and vaccines.
Promadej-Lanier, Nattawan; Thielen, Caroline ULg; Hu, Dale J et al

in AIDS Research and Human Retroviruses (2009), 25(1), 73-81

Abstract We previously observed limited cross-reactive T cell responses in two HIV-1-superinfected injection drug users (IDUs) before superinfection [Ramos A, et al.: J Virol 2002;76(15):7444-7452]. To ... [more ▼]

Abstract We previously observed limited cross-reactive T cell responses in two HIV-1-superinfected injection drug users (IDUs) before superinfection [Ramos A, et al.: J Virol 2002;76(15):7444-7452]. To elucidate the role of such responses in superinfection we examined cross-reactive T cell responses in IDUs infected with a single HIV-1 subtype. In this study, IFN-gamma ELISPOT assays were performed using recombinant vaccinia constructs and peripheral blood mononuclear cells (PBMCs) from 43 IDUs singly infected with CRF01_AE or B' from the same cohort as the superinfected IDUs. PBMCs were from time points corresponding to pre- (early) or post- (late) superinfection in the superinfected IDUs. We observed that most singly infected IDUs had cross-reactivity in samples from early (84% of CRF01_AE and 78% of B'-infected IDUs) and late (96% of CRF_01AE and 77% of B'-infected IDUs) time points. Frequent homologous reactivity at early (67% of CRF-01AE and 100% of B') and late (84% of CRF01_AE-infected and 100% of B'-infected IDUs) time points was also observed. Cross-reactive responses were predominantly to Pol and were broader and higher in CRF01_AE than in B'-infected IDUs (medians of 825 vs. 90 and 585 vs. 60 spot-forming units/10(6) PBMCs at early and late time points, respectively). Our results show that cross-reactive responses were more prevalent with greater height and breadth in singly infected IDUs than previously observed in corresponding collection time points of superinfected IDU. Thus, low or absent cross-reactivity may have contributed to the previously observed superinfections. These data are relevant for understanding superinfection and improving vaccine design. [less ▲]

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See detailInfluence of microstructure on the thermal conductivity of magnetoresistive La0.7Ca0.3MnO3/Mn3O4 manganite/insulating oxide polycrystalline bulk composites
Mucha, J.; Vertruyen, Bénédicte ULg; Misiorek, H. et al

in Journal of Applied Physics (2009), 105(6), 063501

We report the temperature dependence of the thermal conductivity kappa(T) of bulk polycrystalline composite samples containing a magnetoresistive manganite (La0.7Ca0.3MnO3) and an electrically insulating ... [more ▼]

We report the temperature dependence of the thermal conductivity kappa(T) of bulk polycrystalline composite samples containing a magnetoresistive manganite (La0.7Ca0.3MnO3) and an electrically insulating phase (Mn3O4). The sample porosity is shown to be a significant parameter affecting the experimental data: after porosity correction the curves display the characteristics of an ideal composite. A fit of the kappa(T) curves at low temperature using the Debye model enables the mean free path of phonons scattered on "boundaries" to be determined. The values are on the order of the grain size but are influenced by the grain arrangement and the presence of twins. [less ▲]

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See detailRapid synthesis of submicron crystalline barium zirconate BaZrO3 by precipitation in aqueous basic solution below 100 degrees C
Boschini, Frédéric ULg; Rulmont, André ULg; Cloots, Rudi ULg et al

in Journal of the European Ceramic Society (2009), 29(8), 1457-1462

Pure crystalline BaZrO3 powders can be produced by precipitation in highly basic aqueous solution. The influence of several synthesis parameters is studied. At high OH- concentration ([NaOH] = 20 mol/l ... [more ▼]

Pure crystalline BaZrO3 powders can be produced by precipitation in highly basic aqueous solution. The influence of several synthesis parameters is studied. At high OH- concentration ([NaOH] = 20 mol/l), it is possible to obtain the well-crystallized stoichiometric perovskite phase at relatively low temperature (similar to 80 degrees C), after a short reaction time (15 min) and without requiring any precaution to avoid the presence of CO2. This synthesis method yields spherical particles, whose size can be controlled by changing the concentration of the Ba + Zr solution. No calcination treatment is necessary since the precipitate is crystalline. Suitable choice of the synthesis parameters ([NaOH] = 20 mol/l, [Ba + Zr] = 1 mol/l, reaction time= 15 min) yields a sub-micron precipitate with excellent densification behaviour. Corrosion tests in BaO-CuO melt show that similar to 98% dense BaZrO3 obtained by sintering at 1650 degrees C for 13 h could be used for crucibles in the synthesis of YBa2Cu3O7 superconducting single crystals. (C) 2008 Elsevier Ltd. All rights reserved. [less ▲]

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See detailHybridization of short complementary PNAs to G-quadruplex forming oligonucleotides: An electrospray mass spectrometry study.
Amato, Jussara; Oliviero, Giorgia; De Pauw, Edwin ULg et al

in Biopolymers (2009), 91(4), 244-255

We investigated the interaction of the short PNA strand [acccca]-PNA with oligodeoxynucleotides containing one, two, or four tracts of TGGGGT units. Electrospray ionization mass spectrometry allowed ... [more ▼]

We investigated the interaction of the short PNA strand [acccca]-PNA with oligodeoxynucleotides containing one, two, or four tracts of TGGGGT units. Electrospray ionization mass spectrometry allowed exploring the wide variety of complex stoichiometries that were found to coexist in solution. In water, the PNA strand forms short heteroduplexes with the complementary DNA sequences, but higher-order structures are also found, with PNA(2n)*DNA(n) triplex units, culminating in precipitation at very low ionic strength. In the presence of ammonium acetate, there is a competition between PNA*DNA heteroduplex formation and DNA G-quadruplex formation. Heteroduplex formation is favored when the PNA + DNA mixture in ammonium acetate is heated and cooled at room temperature, but not if the PNA is added at room temperature to the pre-formed G-quadruplex. We also found that the short [acccca]-PNA strand binds to G-quadruplexes. (c) 2008 Wiley Periodicals, Inc. Biopolymers, 2008. [less ▲]

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See detailOARSI recommendations on knee and hip osteoarthritis: use with discernment.
Chevalier, Xavier; Henrotin, Yves ULg

in Joint Bone Spine (2009), 76(5), 455-7

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See detailRiemannian Metric and Geometric Mean for Positive Semidefinite Matrices of Fixed Rank
Bonnabel, Silvère; Sepulchre, Rodolphe ULg

in SIAM Journal on Matrix Analysis & Applications (2009), 31(3), 1055--1070

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See detailAdaptive Regulation of Vector Controlled Induction Motors
Jadot, Fabrice; Malrait, Francois; Moreno, Javier et al

in IEEE Transactions on Control Systems Technology (2009), 17(3),

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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 detailPlaidoyer pour une criminologie de terrain(s)
Dantinne, Michaël ULg

in Revue de Droit Pénal et de Criminologie (2009)

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See detailUrban ontologies for an improved communication in urban development projects
Teller, Jacques ULg; Cutting-Decelle, Anne-Françoise; Billen, Roland ULg

Book published by Les éditions de l'Université de Liège (2009)

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See detailBiomagnification of naturally-produced methoxylated polybrominated diphenyl ethers (MeO-PBDEs) in harbour seals and harbour porpoises from the Southern North Sea
Weijs, Liesbeth; Losada, Sara; Das, Krishna ULg et al

in Environment International (2009), 35

Harbour seals and harbour porpoises are top predator species from the North Sea, have long life spans and hence, are known to accumulate high levels of anthropogenic contaminants. To gain knowledge about ... [more ▼]

Harbour seals and harbour porpoises are top predator species from the North Sea, have long life spans and hence, are known to accumulate high levels of anthropogenic contaminants. To gain knowledge about the behaviour of naturally-produced compounds in these marine mammals, the biomagnification of naturally-produced methoxylated polybrominated diphenyl ethers (MeO-PBDEs) was assessed. The biomagnification of MeO-PBDEs (2'-MeO-BDE 68 and 6-MeO-BDE 47) was lower in harbour seals (all biomagnification factors (BMFs) < 1) compared to the same age-gender groups of the harbour porpoises (all BMFs > 1). This may indicate a better metabolic breakdown of MeO-PBDEs in harbour seals, as was previously suggested for polybrominated diphenyl ethers (PBDEs). In both predators, 6-MeO-BDE 47 had the highest concentrations (range: 45-483 ng/g lw and 2-38 ng/g lw for harbour porpoises and seals, respectively) compared to 2'-MeO-BDE 68 (range: 2-28 ng/g lw and 1-6 ng/g lw for harbour porpoises and seals, respectively). In general, the highest concentrations were found in juveniles, suggesting an increased biotransformation capacity with age or the influence of dilution by growth for both species. Here we show that naturally-produced brominated organic compounds can biomagnify and accumulate in North Sea top predators, although to a lesser extent than anthropogenic lipophilic contaminants, such as polychlorinated biphenyls (PCBs) or PBDEs. [less ▲]

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See detailChapitre IV: La politique fiscale et budgétaire
Jurion, Bernard ULg

in Beaufays, Jean; Matagne, Geoffroy (Eds.) La Belgique en mutation. Systèmes politiques et politiques publiques (1968-2008) (2009)

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See detailSynchronization in Networks of Identical Linear Systems
Scardovi, Luca; Sepulchre, Rodolphe ULg

in Automatica (2009), 45(11), 2557-2562

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See detailHigh-throughput methodology applied to screening of carbohydrate-based surfactant interfacial properties for colloidal system formulations
Razafindralambo, Hary ULg; Blecker, Christophe ULg; Deroanne et al

Poster (2009)

Carbohydrate-based surfactants (CBS) constitute an attractive class of amphiphilic molecules owing to their structural diversity generating a wide range of properties which could be developed in food and ... [more ▼]

Carbohydrate-based surfactants (CBS) constitute an attractive class of amphiphilic molecules owing to their structural diversity generating a wide range of properties which could be developed in food and non-food applications. Based on many functional groups of the carbohydrate part, it is possible to design multiple amphiphilic structures of CBS varying in the hydrophilic head groups (mono-, oligo-, or polysaccharides), hydrophobic tail (mono-, di-, tricatenar) but also in the linker/spacer between them. The main structures of CBS include mono- and bicatenar glycolipids, bolaforms, and gemini. Moreover, CBS compounds can be produced from the most abundant renewable materials allowing large product concept possibilities. Among general properties of surfactants, interfacial properties molecules occupy a fundamental key role for colloidal system formulations since they control most of technological aptitudes required for forming and stabilizing food, cosmetic, agrochemical, detergent, and pharmaceutical products. High-throughput methodology applied to screening of CBS interfacial properties appears crucial for achieving optimum formulations of colloidal systems like foams and emulsions for which small amounts of single or mix surface-active agents are often needed and numerous physical and chemical parameters are involved. This general approach may be applied to any amphiphilic molecules produced from other renewable resources of surface-active compounds like micro-organisms and by direct extraction from vegetable materials. One of the key factors for the development of this methodology is the use of automated instrument systems in laboratory scale which are still lacking in this field compared to those existing in the analytical chemistry and biochemistry areas. [less ▲]

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See detailLes cas cliniques, une vision panachee de la medecine: de la simple anecdote a l'enseignement pratique.
Lefebvre, Pierre ULg; Scheen, André ULg

in Revue Médicale de Liège (2009), 64(7-8), 357

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See detailHomeostatic sleep pressure and responses to sustained attention in the suprachiasmatic area.
Schmidt, Christina ULg; Collette, Fabienne ULg; Leclercq, Yves ULg et al

in Science (2009), 324(5926), 516-9

Throughout the day, cognitive performance is under the combined influence of circadian processes and homeostatic sleep pressure. Some people perform best in the morning, whereas others are more alert in ... [more ▼]

Throughout the day, cognitive performance is under the combined influence of circadian processes and homeostatic sleep pressure. Some people perform best in the morning, whereas others are more alert in the evening. These chronotypes provide a unique way to study the effects of sleep-wake regulation on the cerebral mechanisms supporting cognition. Using functional magnetic resonance imaging in extreme chronotypes, we found that maintaining attention in the evening was associated with higher activity in evening than morning chronotypes in a region of the locus coeruleus and in a suprachiasmatic area (SCA) including the circadian master clock. Activity in the SCA decreased with increasing homeostatic sleep pressure. This result shows the direct influence of the homeostatic and circadian interaction on the neural activity underpinning human behavior. [less ▲]

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