Découverte de substances naturelles antipaludiques et métabolomique.

Scientific conference (2012, May 16)

Découverte du genre Rellimia Leclercq & Bonamo (Aneurophytales) en Afrique: un apport à la paléogéographie du Dévonien Moyen.

Conference (2002)

Découverte fortuite, rue Féronstrée à Liège (B.)

in Archaeologia Mediaevalis (1981), 4

Interesting group of medieval potteries of mosan type was found in a private well.

Découverte récente de Nyctalus leisleri en Corse

in Mammalia (1983), 47(3), 425-426

Découvertes récentes dans la chimie des alcaloïdes du Strychnos usambarensis GILG

in Plantes médicinales et phytothérapie (1973), 7(4), 284-292

Six bis-indole alkaloids have been isolated from the rootbark of Strychnos usambarensis.Four alkaloids ( usambarensine and derivatives) are unsymmetrical bis-indole products, biogenetically derived from ... [more ▼]

Six bis-indole alkaloids have been isolated from the rootbark of Strychnos usambarensis.Four alkaloids ( usambarensine and derivatives) are unsymmetrical bis-indole products, biogenetically derived from two tryptaminic and one monoterpene units as some alkaloids of Apocynaceae (Ochrosia) and Rubiaceae ( Uncaria), two families very close to Loganiaceae from a chemotaxonomy point of view. Two other alkaloids (C-dihydrotoxiferine and C_Curarine) are symmetrical bis-indole quaternary products. These potent compounds were previously isolated from calabash-curare and some American Strychnos. Furthermore, we have isolated loganic acid and discussed the part that it could take in the biogenesis of various alkaloids. [less ▲]

Découvrir le ciel; Le guide de l'astronomie facile -- J. L. Halbwachs

in Ciel et Terre (1987), 103

Not Available

DECPHOT: An Optimal Deconvolution-based Photometric Reduction Method

in Transiting Extrapolar Planets Workshop (2007, July 01)

A high accuracy photometric reduction method is needed to take full advantage of the potential of the transit method for the detection and characterization of exoplanets, especially in deep crowded fields ... [more ▼]

A high accuracy photometric reduction method is needed to take full advantage of the potential of the transit method for the detection and characterization of exoplanets, especially in deep crowded fields. In this context, we present DECPHOT, a new deconvolution-based photometry algorithm able to deal with a very high level of crowding and large variations of seeing. It also increases the resolution of astronomical images, an important advantage for the discrimination of false positives in transit photometry. [less ▲]

Decrease Of Elastic Moduli Of Dopc Bilayers Induced By A Macrolide Antibiotic, Azithromycin

in Biochimica et Biophysica Acta-Biomembranes (2007), 1768(7), 1830-8

The elastic properties of membrane bilayers are key parameters that control its deformation and can be affected by pharmacological agents. Our previous atomic force microscopy studies revealed that the ... [more ▼]

The elastic properties of membrane bilayers are key parameters that control its deformation and can be affected by pharmacological agents. Our previous atomic force microscopy studies revealed that the macrolide antibiotic, azithromycin, leads to erosion of DPPC domains in a fluid DOPC matrix [A. Berquand, M. P. Mingeot-Leclercq, Y. F. Dufrene, Real-time imaging of drug-membrane interactions by atomic force microscopy, Biochim. Biophys. Acta 1664 (2004) 198-205.]. Since this observation could be due to an effect on DOPC cohesion, we investigated the effect of azithromycin on elastic properties of DOPC giant unilamellar vesicles (GUVs). Microcinematographic and morphometric analyses revealed that azithromycin addition enhanced lipid membranes fluctuations, leading to eventual disruption of the largest GUVs. These effects were related to change of elastic moduli of DOPC, quantified by the micropipette aspiration technique. Azithromycin decreased both the bending modulus (k(c), from 23.1+/-3.5 to 10.6+/-4.5 k(B)T) and the apparent area compressibility modulus (K(app), from 176+/-35 to 113+/-25 mN/m). These data suggested that insertion of azithromycin into the DOPC bilayer reduced the requirement level of both the energy for thermal fluctuations and the stress to stretch the bilayer. Computer modeling of azithromycin interaction with DOPC bilayer, based on minimal energy, independently predicted that azithromycin (i) inserts at the interface of phospholipid bilayers, (ii) decreases the energy of interaction between DOPC molecules, and (iii) increases the mean surface occupied by each phospholipid molecule. We conclude that azithromycin inserts into the DOPC lipid bilayer, so as to decrease its cohesion and to facilitate the merging of DPPC into the DOPC fluid matrix, as observed by atomic force microscopy. These investigations, based on three complementary approaches, provide the first biophysical evidence for the ability of an amphiphilic antibiotic to alter lipid elastic moduli. This may be an important determinant for drug: lipid interactions and cellular pharmacology. [less ▲]

Decrease of frontal metabolism demonstrated by positron emission tomography in a population of healthy elderly volunteers.

in Acta Neurologica Belgica (1991), 91(5), 288-95

Frontal metabolism measured with positron emission tomography is shown to be decreased relatively to that in other cortical or sub-cortical areas, in a population of healthy elderly compared to young ... [more ▼]

Frontal metabolism measured with positron emission tomography is shown to be decreased relatively to that in other cortical or sub-cortical areas, in a population of healthy elderly compared to young volunteers. Cortical atrophy or neuronal depopulation are unlikely to entirely explain this physiological phenomenon, and sub-cortico-cortical deactivation should play a role, analogous to that proposed in subcortical diseases. [less ▲]

Decrease of serum concentrations of dioxins and PCBs in Belgium between 2000 and 2003

in Organohalogen Compounds (2005), 67