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See detailFully automated method for the liquid chromatographic-tandem mass spectrometric determination of cyproterone acetate in human plasma using restricted access material for on-line sample clean-up.
Christians, Benoit; Fillet, Marianne ULg; Chiap, Patrice ULg et al

in Journal of Chromatography. A (2004), 1056(1-2), 105-10

A new automated method for the quantitative analysis of cyproterone acetate (CPA) in human plasma has been developed using on-line solid phase extraction (SPE) prior to the LC-MS/MS determination. The ... [more ▼]

A new automated method for the quantitative analysis of cyproterone acetate (CPA) in human plasma has been developed using on-line solid phase extraction (SPE) prior to the LC-MS/MS determination. The method was based on the use of a pre-column packed with internal-surface reversed-phase material (LiChrospher RP-4 ADS, 25 mm x 2 mm) for sample clean-up coupled to LC separation on an octadecyl silica stationary phase by means of a column switching system. A 30 microl plasma sample volume was injected directly onto the pre-column using a mixture of water, acetonitrile and formic acid (90:10:0.1 (v/v/v)) adjusted to pH 4.0 with diluted ammonia as washing liquid. The analyte was then eluted in the back-flush mode with the LC mobile phase consisting of water, methanol and formic acid (10:90:0.1 (v/v/v)). The dispensing flow rates of the washing liquid and the LC mobile phase were 300 microl min(-1). Medroxyprogesterone acetate (MPA) was used as internal standard. The MS ionization of the analytes was achieved using electrospray (ESI) in the positive ion mode. The pseudomolecular ionic species of CPA and MPA (417.4 and 387.5) were selected to generate daughter ions at 357.4 and 327.5, respectively. Finally, the developed method was validated according to a new approach using accuracy profiles as a decision tool. Very good results with respect to accuracy, detectability, repeatability, intermediate precision and selectivity were obtained. The LOQ of cyproterone acetate was 300 pg ml(-1). [less ▲]

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See detailFully Automated Preparation and Conjugation of N-Succinimidyl 4-[(18)F]Fluorobenzoate ([ (18)F]SFB) with RGD Peptide Using a GE FASTlab Synthesizer.
Thonon, David ULg; Goblet, D.; Goukens, Eve ULg et al

in Molecular imaging and biology : MIB : the official publication of the Academy of Molecular Imaging (2011)

PURPOSE: The aim of this work was to automate the radiosynthesis of [(18)F]SFB, a widely used reagent for the labeling of biomolecules with (18)F on a new generation commercial synthesis module (FASTLab ... [more ▼]

PURPOSE: The aim of this work was to automate the radiosynthesis of [(18)F]SFB, a widely used reagent for the labeling of biomolecules with (18)F on a new generation commercial synthesis module (FASTLab, GE Healthcare). PROCEDURES: Two synthesis approaches were implemented on this module: the classical "two-pot radiosynthesis" and the more recently described "one-pot" method. RESULTS: The "two-pot" approach affords [(18)F]SFB with a 42% decay-corrected yield in 57 min (n = 24) with a chemical purity sufficient to avoid an intermediate HPLC purification. The recently established "one-pot" method, afforded a product with a lower chemical purity, in the conditions used in this report. The lower d.c. yield obtained (32% (n = 15)) was related to the low (18)F labeling yields obtained in MeCN compared with DMSO. The subsequent conjugation step with a RGD (PRGD2) peptide was also successfully automated. CONCLUSIONS: The formulated [(18)F]FPRGD2 was obtained without any operator manipulation with a d.c. yield of 13% +/- 3% (n = 13) in 130 min, a radiochemical purity >98% and a specific activity of 140 +/- 40 TBq/mmol. [less ▲]

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See detailFully Automated Production of 68Ga-DOTA-NOC with a Trasis miniAIO® Synthesizer
Léonard, Marc ULg; Aerts, Joël ULg; Voccia, Samuel et al

Poster (2013, October 22)

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See detailFully automated radiosynthesis of N1-[18F]fluoroethyl-tryptophan and study of its biological activity as a new potential substrate for indoleamine 2,3-dioxygenase PET imaging
Henrottin, Jean ULg; Lemaire, Christian ULg; Egrise, Dominique et al

in Nuclear Medicine & Biology (2016)

Introduction: Indoleamine 2,3-dioxygenase (IDO) catalyzes the initial step in the catabolism of L-tryptophan along the kynurenine pathway and exerts immunosuppressive properties in inflammatory and tumor ... [more ▼]

Introduction: Indoleamine 2,3-dioxygenase (IDO) catalyzes the initial step in the catabolism of L-tryptophan along the kynurenine pathway and exerts immunosuppressive properties in inflammatory and tumor tissues by blocking locally T-lymphocyte proliferation. Recently, 1-(2-[19F]fluoroethyl)-DL-tryptophan (1-[19F]FE-DL-Trp) was reported as a good and specific substrate of this enzyme. Herein, the radiosynthesis of its radioactive isotopomer (1-[18F]FE-DL-Trp, DL-[18F]5) is presented along with in vitro enzymatic and cellular uptake studies. Methods: The one-pot n.c.a. radiosynthesis of this novel potential PET imaging tracer, including HPLC purification and formulation, has been fully automated on a FASTlabTM synthesizer. Chiral separation of both isomers and their formulation were implemented on a second cassette. In vitro enzymatic and cellular uptake studies were then conducted with the D-, L- and DL-radiotracers. Results: The radiolabeling of the tosylate precursor was performed in DMF (in 5 min; RCY: 57% (d.c.), n=3). After hydrolysis, HPLC purification and formulation, DL-[18F]5 was obtained with a global radiochemical yield of 18±3% (not decay corrected, n=7, in 80 min) and a specific activity of 600±180 GBq/µmol (n=5). The subsequent separation of L- and D-enantiomers was performed by chiral HPLC and both were obtained after formulation with a RCY (d.c.) of 6.1% and 5.8%, respectively. In vitro enzymatic assays reveal that L-[18F]5 is a better substrate than D-[18F]5 for human IDO. In vitro cellular assays show an IDO-specific uptake of the racemate varying from 30% to 50% of that of L-[18F]5, and a negligible uptake of D-[18F]5. Conclusion: In vitro studies show that L-[18F]5 is a good and specific substrate of hIDO, while presenting a very low efflux. These results confirm that L-[18F]5 could be a very useful PET radiotracer for IDO expressing cells in cancer imaging. [less ▲]

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See detailA fully coupled anisotropic elasto-plastic-damage model
Cescotto, Serge ULg; Wauters, Michaël; Habraken, Anne ULg et al

in Handbook of Materials Behavior Models (2001)

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See detailA fully coupled elasto-plastic damage model applied to anisotropic materials
Wauters, M.; Habraken, Anne ULg; Duchene, Laurent ULg

in Tassoulas, J. L. (Ed.) Proceedings of the 14th Engineering Mechanics Conference (2000)

In this paper, an elastoplastic energy-based anisotropic damage model for ductile fracture is described. A calibration method is also presented. The potential applicability of this model is illustrated by ... [more ▼]

In this paper, an elastoplastic energy-based anisotropic damage model for ductile fracture is described. A calibration method is also presented. The potential applicability of this model is illustrated by numerical examples of tensile test and Forming Limit Diagram establishment on a steel. [less ▲]

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See detailA fully coupled elasto-plastic damage model applied to anisotropic materials
Wauters, M.; Habraken, Anne ULg; Duchene, Laurent ULg

(2000)

In this paper, an elastoplastic energy-based anisotropic damage model for ductile fracture is described. A calibration method is presented. The potential applicability of this model is illustrated by a ... [more ▼]

In this paper, an elastoplastic energy-based anisotropic damage model for ductile fracture is described. A calibration method is presented. The potential applicability of this model is illustrated by a numerical example of deep drawing process realised on two steels. [less ▲]

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See detailA fully coupled elastoplastic damage modeling and fracture criteria in metalforming processes
Zhu, Y. Y.; Cescotto, Serge ULg; Habraken, Anne ULg

in Journal of Materials Processing Technology (1992), 32

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See detailA fully coupled elastoplastic damage theory based on the energy equivalence
Zhu, Y. Y.; Cescotto, Serge ULg; Habraken, Anne ULg

in Owen, D. R. J.; Onate, E.; Hinton, E. (Eds.) Computational Plasticity, Fundamentals and Applications (1992)

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See detailFully coupled simulation of mechatronic and flexible multibody systems: An extended finite element approach
Bruls, Olivier ULg

Scientific conference (2009, November)

In this talk, I will discuss some extensions and refinements of classical finite element tools for the numerical simulation of complex mechatronic systems. The presentation will be divided into three main ... [more ▼]

In this talk, I will discuss some extensions and refinements of classical finite element tools for the numerical simulation of complex mechatronic systems. The presentation will be divided into three main parts. In the first part, I will show how this approach allows the modeling of dynamic systems with large amplitude motions composed of rigid bodies, flexible bodies, kinematic joints, actuators, sensors and control units. A fully coupled model of a semi-active suspension will be used to illustrate the methodology. The second part will focus on some numerical aspects concerning the time integration of the equations of motion which have the structure of strongly coupled differential-algebraic equations on a Lie group. The treatment of large rotation variables and of the coupling between control state variables and mechanical generalized coordinates will be discussed in more detail. In the third part, the simulation tool will be exploited for the topology optimization of structural components embedded in multibody systems. Generally, topology optimization techniques use simplified quasi-static load cases to mimic the complex dynamic loadings in service. In contrast, I will present an optimization procedure which properly accounts for the actual dynamic interactions which occur during the motion of the flexible multibody system. In order to illustrate the benefits of this integrated design approach, the optimization of a two degrees-of-freedom robot arm with flexible truss linkages will be analyzed. [less ▲]

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See detailA fully coupled thermo-mechanical model for unsaturated soil
François, Bertrand ULg; Laloui, Lyesse

in 2nd International Conference on Porous Media and its Applications in Science, Engineering and Industry (2007)

This paper addresses a new, unified thermomechanical constitutive model for unsaturated soils through a coupled study. In the context of elastoplasticity and the critical state theory, the model uses the ... [more ▼]

This paper addresses a new, unified thermomechanical constitutive model for unsaturated soils through a coupled study. In the context of elastoplasticity and the critical state theory, the model uses the concepts of multi-mechanism and bounding surface theory. This advanced constitutive approach involves thermo-plasticity of saturated and unsaturated soils. Bishop’s effective stress framework is adopted to represent the stress state in the soil. This stress is linked to the water retention curve, which is represented by an elasto-plastic model. Attention is focused particularly on the coupling relations inferred from this unified thermo-hydro-mechanical (THM) study. Finally, the theoretical aspects of the paper are supported by comparisons between numerical simulations and experimental results. [less ▲]

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See detailFully habituated sugarbeet callus: Under permanent stress?
Le Dily, F.; Billard, J.-P.; Huault, C. et al

in In Vitro Cellular & Developmental Biology - Plant (1993), 29(4), 149-154

A fully habituated nonorganogenic (HNO) sugarbeet callus line, compared to a normal (hormone dependent) one originated from the same plant exhibits many characteristics of a vitrified tissue and several ... [more ▼]

A fully habituated nonorganogenic (HNO) sugarbeet callus line, compared to a normal (hormone dependent) one originated from the same plant exhibits many characteristics of a vitrified tissue and several traits common to animal cancer cells. Four types of biochemical or metabolic characteristics of HNO callus [deficiency of tetrapyrrole-containing compounds; lipid (per)oxidation and malondialdehyde formation; high activity of enzyme protective systems; proline, glutamate, and polyamine accumulation] may be interpreted as responses to stress. The deficiency of tetrapyrrole-containing compounds can be considered an indirect protection against activated forms of oxygen as well as the higher activity of the antioxidant defense mechanisms. This fits with suggestions in the literature that the autonomy associated with plant cancer tissue is explained on the basis of antioxidants as stimulators of cell division and corresponding inhibitors of cell differentiation. Such changes occurring in HNO cells may in turn be responsible for a greater absorption and sensitivity to ammonium ions. An altered nitrogen metabolism leads to proline, glutamate, and polyamine accumulation. Lipid peroxidation and malondialdehyde accumulation rapidly occur in this very sensitive HNO callus in a prolonged culture cycle, which might be related to the appearance of necrosis bands. Thus there are arguments allowing us to consider HNO cells as mutants adapted to some stresses, but resulting changes in their structure might have rendered them still more sensitive to other factors. © 1993 Tissue Culture Association. [less ▲]

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See detailFully implicit integration scheme for the GTN model
Guzmán Inostroza, Carlos Felipe ULg; Habraken, Anne ULg

Poster (2014, May 12)

Fully integration scheme for the GTN model, applied to some shear extensions. The model also comprises Hill type anisotropy and mixed (Isotropic/kinematic) hardening. The consistent tangent matrix is also ... [more ▼]

Fully integration scheme for the GTN model, applied to some shear extensions. The model also comprises Hill type anisotropy and mixed (Isotropic/kinematic) hardening. The consistent tangent matrix is also calculated. [less ▲]

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See detailA fully nonlinear finite element model for orthodontic tooth movement prediction
Mengoni, Marlène ULg; D'Otreppe, Vinciane ULg; Ponthot, Jean-Philippe ULg

in Proceedings of the 10th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering. (2012, April)

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See detailThe fully-active and structurally-stable form of the mitochondrial ATP synthase of Polytomella sp is dimeric
Villavicencio-Queijeiro, Alexa; Vazquez-Acevedo, Miriam; Cano-Estrada, Araceli et al

in Journal of Bioenergetics & Biomembranes (2009), 41(1), 1-13

Mitochondrial F1FO-ATP synthase of chlorophycean algae is a stable dimeric complex of 1,600 kDa. It lacks the classic subunits that constitute the peripheral stator-stalk and the orthodox polypeptides ... [more ▼]

Mitochondrial F1FO-ATP synthase of chlorophycean algae is a stable dimeric complex of 1,600 kDa. It lacks the classic subunits that constitute the peripheral stator-stalk and the orthodox polypeptides involved in the dimerization of the complex. Instead, it contains nine polypeptides of unknown evolutionary origin named ASA1 to ASA9. The isolated enzyme exhibited a very low ATPase activity (0.03 Units/mg), that increased upon heat treatment, due to the release of the F-1 sector. Oligomycin was found to stabilize the dimeric structure of the enzyme, providing partial resistance to heat dissociation. Incubation in the presence of low concentrations of several non-ionic detergents increased the oligomycin-sensitive ATPase activity up to 7.0-9.0 Units/mg. Incubation with 3% (w/v) taurodeoxycholate monomerized the enzyme. The monomeric form of the enzyme exhibited diminished activity in the presence of detergents and diminished oligomycin sensitivity. Cross-linking experiments carried out with the dimeric and monomeric forms of the ATP synthase suggested the participation of the ASA6 subunit in the dimerization of the enzyme. The dimeric enzyme was more resistant to heat treatment, high hydrostatic pressures, and protease digestion than the monomeric enzyme, which was readily disrupted by these treatments. We conclude that the fully-active algal mitochondrial ATP synthase is a stable catalytically active dimer; the monomeric form is less active and less stable. Monomer-monomer interactions could be mediated by the membrane-bound subunits ASA6 and ASA9, and may be further stabilized by other polypeptides such as ASA1 and ASA5. [less ▲]

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See detailA fully-differential CMOS-MEMS resonator integrated with an on-chip amplifier
Pachkawade, Vinayak ULg; Cheng-Syun Li; Sheng-Shian Li

in A fully-differential CMOS-MEMS resonator integrated with an on-chip amplifier (2012)

Detailed reference viewed: 6 (2 ULg)