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See detailNew tripodal iminophosphorane-based ethylene oligomerization catalysts - Part II. Catalytic behavior
Beaufort, Laurence; Benvenuti, Federica; Delaude, Lionel ULg et al

in Journal of Molecular Catalysis A : Chemistry (2008), 283(1-2), 77-82

Seven transition-metal complexes of general formula RC(CH2NPR'(3))(3))MX2 based on new tripodal iminophosphorane ligands were investigated as initiators for the oligomerization of ethylene in the presence ... [more ▼]

Seven transition-metal complexes of general formula RC(CH2NPR'(3))(3))MX2 based on new tripodal iminophosphorane ligands were investigated as initiators for the oligomerization of ethylene in the presence of aluminum co-catalysts using high-throughput techniques. In all cases, ethylene consumption peaked at ca. 30 degrees C and was not drastically affected by varying the nature of the metal (M = Ni, Fe, Pd, Cu), the aluminum co-catalyst (MMAO, Et2AlCl, or EtAlCl2) or the substituents of the tris(iminophosphorane) ligand (R = Me, Ph; R'= cyclopentyl, Ph). Structural modifications of the organometallic complexes, either at the metal center or within the tripodal ligand, however, had a significant impact on the oligomer distribution obtained. In particular, Pd-based catalyst (PhC(CH2NPPh3)(3))PdCl2 displayed an excellent selectivity toward hexene formation. (c) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailA new tripodal ligand system based on the iminophosphorane functional group. Part 1: Synthesis and characterization
Beaufort, Laurence; Delaude, Lionel ULg; Noels, Alfred ULg

in Tetrahedron (2007), 63(30), 7003-7008

Two tripodal alcohols, viz., 1,1,1-tris(hydroxymethyl) ethane and alpha, alpha, alpha-tris(hydroxymethyl) toluene were converted by an efficient multi-step pathway involving azide formation into the ... [more ▼]

Two tripodal alcohols, viz., 1,1,1-tris(hydroxymethyl) ethane and alpha, alpha, alpha-tris(hydroxymethyl) toluene were converted by an efficient multi-step pathway involving azide formation into the corresponding tris(iminophosphorane) scaffolds bearing cyclopentyl (Cp) or phenyl groups on their phosphorus atoms, R-C(CH2-N] PR'(3))(3) (R Me or Ph, R'=Cp or Ph). The synthesis of some representative transition-metal complexes of Cu(I), Cu(II), Ni(II), and Pd(II) bearing these new tridentate ligands is also reported. (C) 2007 Elsevier Ltd. All rights reserved. [less ▲]

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See detailA new two-level algorithm for large power systems estimation
Van Cutsem, Thierry ULg; Horward, J-L; Ribbens-Pavella, Mania

in Proc. 7th Power Systems Computation Conference (1981)

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See detailA New Type of Ambiguity in the Planet and Binary Interpretations of Central Perturbations of High-magnification Gravitational Microlensing Events
Choi, J.-Y.; Shin, I.-G.; Han, C. et al

in Astrophysical Journal (2012), 756

High-magnification microlensing events provide an important channel to detect planets. Perturbations near the peak of a high-magnification event can be produced either by a planet or a binary companion ... [more ▼]

High-magnification microlensing events provide an important channel to detect planets. Perturbations near the peak of a high-magnification event can be produced either by a planet or a binary companion. It is known that central perturbations induced by both types of companions can be generally distinguished due to the essentially different magnification pattern around caustics. In this paper, we present a case of central perturbations for which it is difficult to distinguish the planetary and binary interpretations. The peak of a lensing light curve affected by this perturbation appears to be blunt and flat. For a planetary case, this perturbation occurs when the source trajectory passes the negative perturbation region behind the back end of an arrowhead-shaped central caustic. For a binary case, a similar perturbation occurs for a source trajectory passing through the negative perturbation region between two cusps of an astroid-shaped caustic. We demonstrate the degeneracy for two high-magnification events of OGLE-2011-BLG-0526 and OGLE-2011-BLG-0950/MOA-2011-BLG-336. For OGLE-2011-BLG-0526, the χ[SUP]2[/SUP] difference between the planetary and binary model is ~3, implying that the degeneracy is very severe. For OGLE-2011-BLG-0950/MOA-2011-BLG-336, the stellar binary model is formally excluded with Δχ[SUP]2[/SUP] ~ 105 and the planetary model is preferred. However, it is difficult to claim a planet discovery because systematic residuals of data from the planetary model are larger than the difference between the planetary and binary models. Considering that two events observed during a single season suffer from such a degeneracy, it is expected that central perturbations experiencing this type of degeneracy is common. [less ▲]

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See detailA new type of cubic-stacked layer structure in anthoinite, AlWO3(OH3)
Grey, I.; Madsen, I.; Mills et al

in American Mineralogist (2010), 95

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See detailA new type of frameshift mutation in a mitochondrial genome
Remacle, Claire ULg

Poster (1998, June)

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See detailA new universality for random sequential deposition of needles
Vandewalle, Nicolas ULg; Galam, S.; Kramer, M.

in European Physical Journal B -- Condensed Matter (2000), 14(3), 407-410

Percolation and jamming phenomena are investigated for random sequential deposition of rectangular needles on d = 2 square lattices. Associated thresholds p(c)(perc) and p(c)(jam) are determined for ... [more ▼]

Percolation and jamming phenomena are investigated for random sequential deposition of rectangular needles on d = 2 square lattices. Associated thresholds p(c)(perc) and p(c)(jam) are determined for Various needle sizes. Their ratios p(c)(perc)/p(c)(jam) are found to be a constant 0.62 +/- 0.01 for all sizes. In addition the ratio of jamming thresholds for respectively square blocks and needles is also found to be a constant 0.79 +/- 0.01. These constants exhibit some universal connexion in the geometry of jamming and percolation for both anisotropic shapes (needles versus square lattices) and isotropic shapes (square blocks on square lattices). A universal empirical law is proposed for all three thresholds as a function of alpha. [less ▲]

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See detailNew Urban Squares, Documentation for ten urban squares recently designed in the Netherlands
Attia, Shady ULg

Master's dissertation (2005)

It is claimed that Dutch squares have no symbolic meaning or characteristics like in southern Europe. In the Netherlands, urban squares are only used for functional activities. Until the beginning of the ... [more ▼]

It is claimed that Dutch squares have no symbolic meaning or characteristics like in southern Europe. In the Netherlands, urban squares are only used for functional activities. Until the beginning of the 1980s and before the introduction of café terraces or the 'terrasje' culture, the urban squares were only used as ‘marktpleinen’ or market squares. However, this study concludes that almost all the design strategies tried to introduce spacious empty squares. In each example, the design of the squares attempted to allow several activities, accentuate the dynamics of squares and stimulate an active urban life. However, despite the high quality of materials and objects and the effort shown in creating an attractive image of squares, many Dutch urban squares are missing a sense of place and meaning and therefore remain empty. The main aim of this thesis was to provide a simple overview that describes the trends applied during the design of Dutch urban squares in the last 10 years. The first selection criterion for the urban square was based on their location in cities and attachment to pedestrian areas which mean consequently laying in city centres. Secondly, the classification of the case studies was based on their architectural and social identity. As mentioned before, the object of this thesis was to present selected examples of public spaces designs as well as projects illustrating developments in the area of public space architecture. The material presented here was compiled during the years 1995-2003. This study was divided into four parts: (1) Theoretical Orientation, (2) Development of urban squares in the Netherlands, (3) 10 public spaces: Examples of recently designed Dutch urban squares, (4) Conclusion. In the first chapter, the theoretical orientation of the research was introduced. The research structure was discussed including the research objectives and limitations. The research methodology and way of analysing the selected squares was also illustrated. Chapter 2 basically describes the history of Dutch squares, functions, evolution, and the difference between the squares in the Netherlands and countries like France, Spain or Italy. In chapter 3, different analytical method of (1) the square's use and activities, (2) form and proportion, (3) access and context, (4) volume and space, (5) symbolis and (6) greenery and furniture were illustrated through studies of 10 square designs in 10 cities. For each of the squares selected, first a plan of the space was drawn in a scale of 1:1,000. Maps were also drawn showing the city and the surrounding areas in comparable scales. Secondly, each square was described based on its architectural and social identity. Finally each square was criticized using the Project for Public Spaces evaluation criteria. The concluding chapter summarizes problems facing the squares designers in the Netherlands. Problems include the architectural context, greenery, street furniture, materials, and most importantly the ‘Void’ concept. The prognosis that Dutch cities will raise the density of the built environment will make it necessary to adopt renewal and improvement policies. These policies should achieve a coherence of the square’s visual quality and above all improve the sense of place, the sense of meaning and consider squares as places for the people. [less ▲]

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See detailNew use of VEGF in therapeutics: application in tendon lesions
Kaux, Jean-François ULg; Le Goff, Caroline ULg; Drion, Pierre ULg et al

in Clinical Chemistry (2010, July), 56(S6), 111

Introduction: As demonstrated in previous studies, mechanical overload, injury and inflammation, hypoxic condition or any combination of the above could lead to increased expression of VEGF in the tendon ... [more ▼]

Introduction: As demonstrated in previous studies, mechanical overload, injury and inflammation, hypoxic condition or any combination of the above could lead to increased expression of VEGF in the tendon. Thus, VEGF could participate in the healing of pathological tendons. Indeed, some authors are convinced that this neovascularization is the sign of a chronic tendinopathy while others plead in favour of it being a sign of healing processes. The VEGF111, which is a biologically active and proteolysis-resistant VEGF-A isoform, was recently identified. It is induced by ultraviolet B and genotoxic drugs. Experimentation shows that, in nude mice, tumors formed by HEK293 cells expressing VEGF111 develop a more widespread peritumoral neovascularisation than those expressing other VEGF isoforms. Good angiogenic activity and resistance to proteolysis makes VEGF111 a potential beneficial therapeutic option for ischemic diseases. The aim of our study was to determine whether if VEGF111 could have a therapeutic interest in the framework of tendinous pathology. Methods (*): A 5mm defect was surgically induced in Achilles tendon of 60 rats. Rats were divided into 2 groups of 30: A: a control group (no injection) and B: with a VEGF111 injection. The rats of group B received an injection of 100 ng of VEGF111 in situ 1 hour after surgery on the site of the tendon lesion. Afterwards, rats of both groups were placed in their cages without immobilization. After 5, 15 and 30 days, 10 rats of each group were euthanized. The traumatized Achilles tendon of each rat was dissected and removed. Immediately after sampling, tendons were submitted to a biomechanical tensile test up to rupture, using a tensile machine with “Cryo-jaw”. Statistical analyses were made with an ANOVA. Results: A significant increase over time of the force necessary to induce tendon rupture was observed for tendons which had been submitted to an injection of VEGF111 (p=0.016). The force required to break the tendon is always greater for the VEGF111 group (p<0.05). Discussion: We demonstrated that the force necessary to induce the rupture of a rat’s Achilles tendon during biomechanical tensile testing was greater for tendons which had been submitted to an injection of VEGF111. Thus, this experimentation showed that VEGF111 injections could accelerate the tendon healing process and increase the force needed to break tendons in their healing process. Conclusion: VEGF111 could be a new therapy for tendon lesions. However, other experimentation using a rat model with different concentrations of VEGF111 should be made to ascertain the best concentration for this healing process. Acknowledgement: This experimentation was partially financed by “Standard de Liège” and “Lejeune-Lechien” grants. (*) All experimental procedures and protocols used in this investigation were reviewed and approved by the Institutional Animal Care and Use Committee of the University of Liège. [less ▲]

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See detailNew validation strategy for the LC determination of ascorbic acid in sublingual tablets
Cahay, B.; Rousseau, Anne ULg; Klinkenberg, R. et al

Poster (2006)

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See detailA new variant of the carbohydrate deficient glycoproteins syndrome.
RAMAEKERS, Vincent ULg; Stibler, H.; Kint, J. et al

in Journal of inherited metabolic disease (1991), 14(3), 385-8

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See detailA new variant of the Ntn hydrolase fold revealed by the crystal structure of L-aminopeptidase D-ala-esterase/amidase from Ochrobactrum anthropi.
Bompard-Gilles, C; Villeret, V; Davies, G J et al

in Structure (2000), 8(2), 153-62

BACKGROUND: The L-aminopeptidase D-Ala-esterase/amidase from Ochrobactrum anthropi (DmpA) releases the N-terminal L and/or D-Ala residues from peptide substrates. This is the only known enzyme to liberate ... [more ▼]

BACKGROUND: The L-aminopeptidase D-Ala-esterase/amidase from Ochrobactrum anthropi (DmpA) releases the N-terminal L and/or D-Ala residues from peptide substrates. This is the only known enzyme to liberate N-terminal amino acids with both D and L stereospecificity. The DmpA active form is an alphabeta heterodimer, which results from a putative autocatalytic cleavage of an inactive precursor polypeptide. RESULTS: The crystal structure of the enzyme has been determined to 1.82 A resolution using the multiple isomorphous replacement method. The heterodimer folds into a single domain organised as an alphabetabetaalpha sandwich in which two mixed beta sheets are flanked on both sides by two alpha helices. CONCLUSIONS: DmpA shows no similarity to other known aminopeptidases in either fold or catalytic mechanism, and thus represents the first example of a novel family of aminopeptidases. The protein fold of DmpA does, however, show structural homology to members of the N-terminal nucleophile (Ntn) hydrolase superfamily. DmpA presents functionally equivalent residues in the catalytic centre when compared with other Ntn hydrolases, and is therefore likely to use the same catalytic mechanism. In spite of this homology, the direction and connectivity of the secondary structure elements differ significantly from the consensus Ntn hydrolase topology. The DmpA structure thus characterises a new subfamily, but supports the common catalytic mechanism for these enzymes suggesting an evolutionary relationship. [less ▲]

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See detailA new variational principle for finite elastic displacements
Fraeijs de Veubeke, Baudouin ULg

in International Journal for Engineering Science (1972), 10(9), 745-763

After a discussion of existing variational principles, a new set of variational principles, of displacement, canonical or complementary energy types, is found to derive from the polar decomposition of the ... [more ▼]

After a discussion of existing variational principles, a new set of variational principles, of displacement, canonical or complementary energy types, is found to derive from the polar decomposition of the jacobian. It involves the engineering strain tensor and its conjugate stress tensor is to be regarded as a function of the Piola tensor and the material rotaion. The complementary energy formulation is discussed in terms of firs order stress functions. The presence of the rotational degrees of freedom opens the possibility of discretizing the rotational equilibrium equaions in approximate solutions. [less ▲]

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See detailA new vegetation map and its inclusion in a global biosphere model
Warnant, Pierre ULg; François, Louis ULg; Nemry, Bernard et al

in Guyot (Ed.) Photosynthesis and remote sensing (1995)

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See detailNew Version of the Catalytic Asymmetric Dihydroxylation
Colaux, Catherine ULg

Conference (2000, May)

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See detailA new version of the moment method, optimized for mode identification in multiperiodic stars
Briquet, Maryline ULg; Aerts, C.

Conference (2002, July)

We present a numerical version of the moment method for the identification of non-radial pulsation modes. The new version requires less computation time than the previous one, allowing to consider all the ... [more ▼]

We present a numerical version of the moment method for the identification of non-radial pulsation modes. The new version requires less computation time than the previous one, allowing to consider all the information contained in the first three moments of a multiperiodic star and to identify multiple modes simultaneously. This, together with the use of a new discriminant which considers the moments calculated at each time of observation, increases the feasibility and the accuracy of the mode identification for multiperiodic stars. Moreover, the technique is extended to rotating pulsating stars. We apply the new version to three B stars showing multiperiodicity. [less ▲]

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See detailA New Version of the Moment Method, Optimized for Mode Identification in Multiperiodic Stars
Briquet, Maryline ULg; Aerts, C.

in Asteroseismology Across the HR Diagram (2003)

Not Available

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See detailA new version of the moment method, optimized for mode identification in multiperiodic stars
Briquet, Maryline ULg; Aerts, C.

in Interplay of periodic, cyclic and stochastic variability in selected areas of the H-R diagram: proceedings of a workshop held in Brussels, Belgium, 22-24 July 2002 (2003)

We present a numerical version of the moment method for the identification of non-radial pulsation modes. The new version requires less computation time than the previous one, allowing to consider all the ... [more ▼]

We present a numerical version of the moment method for the identification of non-radial pulsation modes. The new version requires less computation time than the previous one, allowing to consider all the information contained in the first three moments of a multiperiodic star and to identify multiple modes simultaneously. This, together with the use of a new discriminant which considers the moments calculated at each time of observation, increases the feasibility and the accuracy of the mode identification for multiperiodic stars. Moreover, the technique is extended to rotating pulsating stars. We apply the new version to three B stars showing multiperiodicity. [less ▲]

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See detailA new version of the moment method, optimized for mode identification in multiperiodic stars
Briquet, Maryline ULg; Aerts, C.

in Astronomy and Astrophysics (2003), 398

We present a numerical version of the moment method for the identification of non-radial pulsation modes. The new version requires less computation time than the previous one, allowing users to consider ... [more ▼]

We present a numerical version of the moment method for the identification of non-radial pulsation modes. The new version requires less computation time than the previous one, allowing users to consider all the information contained in the first three moments of a multiperiodic star and to identify multiple modes simultaneously. This, together with the use of a new discriminant that considers the moments calculated at each time of observation, increases considerably the feasibility and the accuracy of the mode identification for multiperiodic stars. Moreover, the technique is extended to rotating pulsating stars. We apply the new version to three B stars showing multiperiodicity. Computer code for mode identification available upon request. Tables 1 to 8 are only available in electronic form at http://www.edpsciences.org [less ▲]

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See detailA new very interesting pair of quasars - Q0107 - 025 A and B
Surdej, Jean ULg; Swings, Jean-Pierre ULg; Henry, A. et al

in 24th Liege International Astrophysical Colloquium: "Quasars and gravitational lenses" (1983)

A search for ultraviolet-excess objects in a field centered around NGC 450 has revealed the presence of two quasar-candidates (18.2 and 17.4 mag) fairly near one another (separation of 77 arcsec ... [more ▼]

A search for ultraviolet-excess objects in a field centered around NGC 450 has revealed the presence of two quasar-candidates (18.2 and 17.4 mag) fairly near one another (separation of 77 arcsec). Preliminary spectroscopy with the Palomar 5 m telescope shows that these objects are indeed two quasars (Q0107 - 025 A and B) having very similar spectra and redshifts (of about 0.96), suggesting a new possible case of twin quasars or of a gravitational lens. Although the analysis (to be published elsewhere) of additional spectroscopic data collected with the ESO 3.6 m telescope rather favors the first interpretation, higher resolution data are still necessary before rejecting definitely the second possibility. Deep multi-color CCD frames obtained with the Danish 1.5 m telescope clearly show that a group (or cluster) of faint galaxies is detected in the vicinity of the two quasars. [less ▲]

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