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See detailStructural, Kinetic, and Calorimetric Characterization of the Cold-Active Phosphoglycerate Kinase from the Antarctic Pseudomonas Sp. Tacii18
Bentahir, Mostafa; Feller, Georges ULg; Aittaleb, Mohamed et al

in Journal of Biological Chemistry (2000), 275(15), 11147-53

The gene encoding the phosphoglycerate kinase (PGK) from the Antarctic Pseudomonas sp. TACII18 has been cloned and found to be inserted between the genes encoding for glyceraldhyde-3-phosphate ... [more ▼]

The gene encoding the phosphoglycerate kinase (PGK) from the Antarctic Pseudomonas sp. TACII18 has been cloned and found to be inserted between the genes encoding for glyceraldhyde-3-phosphate dehydrogenase and fructose aldolase. The His-tagged and the native recombinant PGK from the psychrophilic Pseudomonas were expressed in Escherichia coli. The wild-type and the native recombinant enzymes displayed identical properties, such as a decreased thermostability and a 2-fold higher catalytic efficiency at 25 degrees C when compared with the mesophilic PGK from yeast. These properties, which reflect typical features of cold-adapted enzymes, were strongly altered in the His-tagged recombinant PGK. The structural model of the psychrophilic PGK indicated that a key determinant of its low stability is the reduced number of salt bridges, surface charges, and aromatic interactions when compared with mesophilic and thermophilic PGK. Differential scanning calorimetry of the psychrophilic PGK revealed unusual variations in its conformational stability for the free and substrate-bound forms. In the free form, a heat-labile and a thermostable domain unfold independently. It is proposed that the heat-labile domain acts as a destabilizing domain, providing the required flexibility around the active site for catalysis at low temperatures. [less ▲]

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See detailMembrane Type 1 Matrix Metalloproteinase-Associated Degradation of Tissue Inhibitor of Metalloproteinase 2 in Human Tumor Cell Lines
Maquoi, Erik ULg; Frankenne, Francis ULg; Baramova, Eugénia et al

in Journal of Biological Chemistry (2000), 275(15), 11368-78

Tissue inhibitor of metalloproteinase 2 (TIMP-2) is required for the membrane type 1 matrix metalloproteinase (MT1-MMP)-dependent activation of pro-MMP-2 on the cell surface. MT1-MMP-bound TIMP-2 has been ... [more ▼]

Tissue inhibitor of metalloproteinase 2 (TIMP-2) is required for the membrane type 1 matrix metalloproteinase (MT1-MMP)-dependent activation of pro-MMP-2 on the cell surface. MT1-MMP-bound TIMP-2 has been shown to function as a receptor for secreted pro-MMP-2, resulting in the formation of a trimolecular complex. In the presence of uncomplexed active MT1-MMP, the prodomain of cell surface-associated MMP-2 is cleaved, and activated MMP-2 is released. However, the behavior of MT1-MMP-bound TIMP-2 during MMP-2 activation is currently unknown. In this study, (125)I-labeled recombinant TIMP-2 ((125)I-rTIMP-2) was used to investigate the fate of TIMP-2 during pro-MMP-2 activation by HT1080 and transfected A2058 cells. HT1080 and A2058 cells transfected with MT1-MMP cDNA (but not vector-transfected A2058 cells) were able to bind (125)I-rTIMP-2, to activate pro-MMP-2, and to process MT1-MMP into an inactive 43-kDa form. Under these conditions, (125)I-rTIMP-2 bound to the cell surface was rapidly internalized and degraded in intracellular organelles through a bafilomycin A(1)-sensitive mechanism, and (125)I-bearing low molecular mass fragment(s) were released in the culture medium. These different processes were inhibited by hydroxamic acid-based synthetic MMP inhibitors and rTIMP-2, but not by rTIMP-1 or cysteine, serine, or aspartic proteinase inhibitors. These results support the concept that the MT1-MMP-dependent internalization and degradation of TIMP-2 by some tumor cells might be involved in the regulation of pericellular proteolysis. [less ▲]

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See detailSpectropolarimetry of the iron low ionization broad absorption line quasar Q 0059-2735
Lamy, H.; Hutsemekers, Damien ULg

in Astronomy and Astrophysics (2000), 356(Letters), 9-12

We present optical (ultraviolet rest-frame) spectropolarimetric observations of the rare iron low ionization broad absorption line (BAL) QSO Q 0059-2735. The continuum polarization increases to the blue ... [more ▼]

We present optical (ultraviolet rest-frame) spectropolarimetric observations of the rare iron low ionization broad absorption line (BAL) QSO Q 0059-2735. The continuum polarization increases to the blue with a regular rotation of the polarization position angle, suggesting that at least two mechanisms are at the origin of the polarization. There is also some evidence for dilution by a ion {Fe}{ii} pseudo-continuum in emission. In the broad absorption lines, the polarization strongly rises, with the largest values ever reported. On the contrary, the ion {Fe}{ii} blends in absorption are not more polarized than the continuum, while they are clearly visible in the polarized flux. These different polarization properties of ion {Fe}{ii} absorption lines suggest a different origin and/or geometry. The observed properties of Q 0059-2735 are consistent with a hybrid QSO / starburst model. Based on observations collected at the European Southern Observatory, La Silla, Chile [less ▲]

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See detailComment resoudre en pratique un probleme diagnostique ou therapeutique en suivant une demarche EBM?
Delvenne, Catherine ULg; Pasleau, Françoise ULg

in Revue Médicale de Liège (2000), 55(4), 226-32

Evidence-Based Medicine (EBM) can be defined as the use of best current evidence from clinical research in making decisions about the care of individual patients. It consists of a process of turning ... [more ▼]

Evidence-Based Medicine (EBM) can be defined as the use of best current evidence from clinical research in making decisions about the care of individual patients. It consists of a process of turning clinical problems into questions and then locating the best available evidence to answer them, critically appraising the evidence for its validity and usefulness, and applying the findings to clinical practice. The present article presents the EBM principles and their application to diagnostic and therapeutic questions. Further detailed information on Evidence-Based Medicine is presented at the URL address: http: inverted question markwww.ebm.lib.ulg.ac.be/prostate/ebm.+ ++htm. [less ▲]

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See detailNumerical Modelling of the Forging Process of Rolls for Rolling Mills
Castagne, S.; Charles; Habraken, Anne ULg et al

in Proceedings of the 2nd International Conference on forging and related technology (2000, April)

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See detailDependence of phase morphology and mechanical properties of PS/SBR/PE ternary blends on composition: transition from core-shell to triple-phase continuity structures
Luzinov, Igor; Pagnoulle, Christophe; Jérôme, Robert ULg

in Polymer (2000), 41(9), 3381-3389

The weight ratio of PE and PS in ternary PS/SBR/PE blends has been changed at constant SBR content (25 wt%). When the matrix is either PE or PS, the dispersed phase has a core-shell structure with SBR ... [more ▼]

The weight ratio of PE and PS in ternary PS/SBR/PE blends has been changed at constant SBR content (25 wt%). When the matrix is either PE or PS, the dispersed phase has a core-shell structure with SBR forming the shell. The size of the core expectedly increases with the content of the core-forming polymer. In some composition range, the three phases are simultaneously continuous, SBR being localized in between the co-continuous PE and PS phases. The ultimate mechanical properties of the ternary blends containing SBR/PE and SBR/PS core-shell dispersed phases are close to the properties of the PS/SBR and PE/SBR binary blends, respectively. Some synergism in the elongation at break of the ternary blends is observed when core-shell SBR/PS phases are dispersed in PE matrix. [less ▲]

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See detailSingle-step reactive extrusion of PLLA in a corotating twin-screw extruder promoted by 2-ethylhexanoic acid tin(II) salt and triphenylphosphine
Jacobsen, S.; Fritz, H. G.; Degée, Philippe et al

in Polymer (2000), 41(9), 3395-3403

The ring opening polymerisation of L,L-lactide using an equimolar complex of 2-ethylhexanoic acid tin(II) salt Sn(Oct)2 and triphenylphosphine P( )3 as catalyst shows for the first time a reactivity ... [more ▼]

The ring opening polymerisation of L,L-lactide using an equimolar complex of 2-ethylhexanoic acid tin(II) salt Sn(Oct)2 and triphenylphosphine P( )3 as catalyst shows for the first time a reactivity providing a polymerisation propagation rate fast enough to imagine a continuous single-step reactive extrusion process for bulk polymerisation. The ring opening polymerisation has been realised on a corotating closely intermeshing twin-screw extruder, using a specially designed screw concept to provide sufficient energy input and mixing for further enhancement of the propagation rate, without detrimentally enhancing depolymerisation or transesterification reactions. Using one chosen screw and processing concept on a twin-screw extruder with 25 mm diameter and a L/D-ratio of 48, the influence of different processing parameters on the resulting molecular parameters of the Polylactide (PLA) has been determined. Furthermore, the mechanical property profile of the generated PLA-polymers is discussed and related to the molecular parameters. [less ▲]

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See detailXPS analysis of the PC/PVDF interface modified by PMMA. Location of the PMMA at the interface
Moussaif, Noureddine; Pagnoulle, Christophe; Riga, Joseph et al

in Polymer (2000), 41(9), 3391-3394

Polycarbonate (PC) and polyvinylidenefluoride (PVDF) are two immiscible polymers, which form two-phase polyblends with a weak interfacial adhesion and a high interfacial tension. This situation may be ... [more ▼]

Polycarbonate (PC) and polyvinylidenefluoride (PVDF) are two immiscible polymers, which form two-phase polyblends with a weak interfacial adhesion and a high interfacial tension. This situation may be changed by the addition of polymethylmethacrylate (PMMA), which is miscible with PVDF and concentrates at the PVDF/PC interface. Location of PMMA at the PC/PVDF interface has been confirmed by XPS analysis, which shows that the interface enrichment in PMMA already takes place when only 10 wt% PMMA is premixed with PVDF. [less ▲]

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See detailGalloping data base on single and bundle conductors prediction of maximum amplitudes
Lilien, Jean-Louis ULg; Havard, Dave

in IEEE Transactions on Power Delivery (2000), 15(N°2), 670-674

A data base of 166 cases has been analysed to produced formula to predict galloping amplitudes on power lines either for single conductor of bundle conductor lines.Calculation enhanced the prediction for ... [more ▼]

A data base of 166 cases has been analysed to produced formula to predict galloping amplitudes on power lines either for single conductor of bundle conductor lines.Calculation enhanced the prediction for single conductors but predict larger amplitudes for bundle. [less ▲]

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See detailCalculation of spacer compression for bundle lines under short-circuit.
Lilien, Jean-Louis ULg; papailiou, Konstantin

in IEEE Transactions on Power Delivery (2000), 15(N°2), 839-845

Short-circuit tests results and proposal of a new method to improve Manuzio formula on bundle conductors spacer compression.

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See detailL'Université au fil du temps. Premiers pas au Jardin Botanique.
Frankignoulle, Pierre ULg

Article for general public (2000)

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See detailNovel functionalized oligo-vinylthiophene molecules with modulated second-order nonlinear optical response
dos Santos, D. A.; Kogej, T.; Brédas, Jean-Luc et al

in Journal of Molecular Structure (2000), 521

We present a joint theoretical and experimental investigation of the second-order nonlinear optical properties of a new kind of active molecule with a triblock structure. The molecular architecture is ... [more ▼]

We present a joint theoretical and experimental investigation of the second-order nonlinear optical properties of a new kind of active molecule with a triblock structure. The molecular architecture is such that two highly polarizable conjugated segments are separated from each other by a spacer; one of the conjugated segments is end-capped with an electron-donor group, the other one by an acceptor. E-vinylthiophenes are used as the conjugated segments; N,N-dimethylaniline and nitrophenyl are selected as the donor-acceptor pairs, while the spacer consists of a nonconjugated moiety. Several spacers are considered and discussed with respect to their ability to modulate the charge transfer between the donor and acceptor ends. [less ▲]

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See detailDemonstration in Vivo That Stromelysin-3 Functions through Its Proteolytic Activity
Noël, Agnès ULg; Boulay, A.; Kebers, F. et al

in Oncogene (2000), 19(12), 1605-12

Stromelysin-3 (ST3), a matrix metalloproteinase (MMP) expressed in aggressive carcinomas, has been shown to promote tumor development in different in vivo experimental models. However, the inability of ... [more ▼]

Stromelysin-3 (ST3), a matrix metalloproteinase (MMP) expressed in aggressive carcinomas, has been shown to promote tumor development in different in vivo experimental models. However, the inability of its mature form to degrade extracellular matrix components casts doubt on whether ST3 functions in vivo as a protease. In this study, we evaluated whether the ST3 tumor-promoting effect could be ascribed to its proteolytic activity and whether this putative protease could be targeted with MMP inhibitors. Catalytically inactive mutant cDNA of human (h) ST3 or mouse (m) ST3 were generated and transfected into MCF7 cells. When injected into nude mice in the presence of matrigel, the mutant-bearing cells did not exhibit the enhanced tumorigenicity elicited by MCF7 cells transfected with wild-type ST3 cDNA. In a second approach, TIMP2 overproduction in MCF7 cells expressing hST3 was induced by retroviral infection. The co-expression of ST3 and TIMP2 failed to enhance the tumorigenicity of MCF7 cells. Notably, matrigel depleted of low-molecular-weight proteins and growth factors failed to promote the tumorigenicity of ST3-expressing MCF7 cells. These findings provide the first in vivo evidence that ST3 is indeed a protease that can modulate cancer progression by remodeling extracellular matrix and probably by inducing it to release the necessary microenvironmental factors. Thus, ST3 represents an interesting target for specific MMP inhibition. [less ▲]

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See detailEvaluation environnementale de l'agriculture
Debouche, Charles ULg

Scientific conference (2000, March 03)

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See detailOptical polarization of 47 quasi-stellar objects: The data
Lamy, H.; Hutsemekers, Damien ULg

in Astronomy and Astrophysics. Supplement Series (2000), 142

New broad-band linear polarization measurements are presented for a sample of 47 QSOs which includes 27 broad absorption line QSOs and 2 gravitational lens candidates. Tables 3 and 4 are also available in ... [more ▼]

New broad-band linear polarization measurements are presented for a sample of 47 QSOs which includes 27 broad absorption line QSOs and 2 gravitational lens candidates. Tables 3 and 4 are also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html Based on observations collected at the European Southern Observatory (ESO, La Silla). [less ▲]

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