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See detailMass Spectrometric Study of Dissociative Attachment in Diatomic Molecules:I. CO and H2
Locht, Robert ULg; Momigny, Jacques

in International Journal of Mass Spectrometry and Ion Physics (1969), 2

A study of the shape of the DA peaks leads to a general method for the determination of the threshold of a DA process. In order to test this method, the negative ions appearing in CO and H2 have been ... [more ▼]

A study of the shape of the DA peaks leads to a general method for the determination of the threshold of a DA process. In order to test this method, the negative ions appearing in CO and H2 have been investigated, using a sector field instrument. An attempt has been made to establish the relative positions of the potential energy curves (using the Morse function) for the electronic states involved in the processes observed [less ▲]

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See detailMass Spectrometric Study of Dissociative Electron Attachment in Carbon Dioxide.
Locht, Robert ULg; Momigny, Jacques

in Bulletin de la Société Royale des Sciences de Liège (1971), 40(9/10), 518-523

The DA efficiency curve of O- in CO2 has been studied mass spectrometricaly. Combining the use of the convolution of theoretical models and the deconvolution of the experimental curves, beside the ... [more ▼]

The DA efficiency curve of O- in CO2 has been studied mass spectrometricaly. Combining the use of the convolution of theoretical models and the deconvolution of the experimental curves, beside the previously reported DA peaks, some new DA processes have been determined at (6.0+/-0.3) eV and (13.3+/-0.4) eV for O- in CO2. A progressive conversion of electronic into vibrational excitation of diatomic radicals and into kinetic energy of the fragments is postulated as responsible for the threshold at (6.0+/-0.3) eV. [less ▲]

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See detailMass Spectrometric Study of Ion-Pair Processes in Diatomic Molecules: H2, CO, NO and O2.
Locht, Robert ULg; Momigny, Jacques

in International Journal of Mass Spectrometry and Ion Physics (1971), 7

The appearance of ion-pair processes has been studied in H2, CO, NO and O2. The different thresholds have been interpreted. Convolution and deconvolution techniques have been applied to the ionization ... [more ▼]

The appearance of ion-pair processes has been studied in H2, CO, NO and O2. The different thresholds have been interpreted. Convolution and deconvolution techniques have been applied to the ionization efficiency curves to determine (i) a method for the determination of the threshold energy and (ii) the kinetic energy distribution of the fragments. [less ▲]

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See detailMass Spectrometric Study of the Ionized C60: (Gamma-Cyclodextrin)2 Inclusion Complex by Collision Induced Dissociation
Greisch, Jean-François ULg; Kyritsoglou, S.; Leyh, Bernard ULg et al

in Journal of Mass Spectrometry [=JMS] (2008), 43(2), 242-50

The water soluble inclusion complex [C(60):(gamma-cyclodextrin)(2)] has been characterized using electrospray tandem mass spectrometry and collision induced dissociation. [C(60):(gamma-cyclodextrin)(2 ... [more ▼]

The water soluble inclusion complex [C(60):(gamma-cyclodextrin)(2)] has been characterized using electrospray tandem mass spectrometry and collision induced dissociation. [C(60):(gamma-cyclodextrin)(2)] ions were detected in the gas phase as doubly deprotonated, doubly protonated and doubly sodiated ions. The absence of monocharged complex ions following electronebulization is a likely consequence of the dimeric nature and structural symmetry of the inclusion complex. The collision induced dissociation of positive ions led exclusively to the observation of the protonated and sodiated cyclodextrin ions as well as their fragments. In negative ion mode the closed shell anion C(60)H(-) was the dominant fragment detected at low collision energies whereas at higher collision energies the signal corresponding to deprotonated cyclodextrin units becomes significant. Since C(60) (2-) has been reported to have a nonnegligible basicity compared to C(60) and C(60) (-), it is likely that the proton transfer involved in the formation of the C(60)H(-) anion occurs following transfer of the two electrons from the deprotonated gamma-cyclodextrins to the fullerene. Finally, the charge state of the inclusion complex ions is also shown to affect the interaction strengths between its subunits. The relative stabilities of the three ionic species studied in gas phase following electronebulization are as follows: [C(60):(gamma-cyclodextrin)(2) + 2H](2+) < [C(60):(gamma-cyclodextrin)(2)- 2H](2-) < [C(60):(gamma-cyclodextrin)(2) + 2Na](2+). [less ▲]

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See detailMass spectrometry and ion mobility spectrometry of G-quadruplexes. A study of solvent effects on dimer formation and structural transitions in the telomeric DNA sequence d(TAGGGTTAGGGT).
Ferreira, Ruben; Marchand, Adrien; Gabelica, Valérie ULg

in Methods (2012), 57(1), 56-63

We survey here state of the art mass spectrometry methodologies for investigating G-quadruplexes, and will illustrate them with a new study on a simple model system: the dimeric G-quadruplex of the 12-mer ... [more ▼]

We survey here state of the art mass spectrometry methodologies for investigating G-quadruplexes, and will illustrate them with a new study on a simple model system: the dimeric G-quadruplex of the 12-mer telomeric DNA sequence d(TAGGGTTAGGGT), which can adopt either a parallel or an antiparallel structure. We will discuss the solution conditions compatible with electrospray ionisation, the quantification of complexes using ESI-MS, the interpretation of ammonium ion preservation in the complexes in the gas phase, and the use of ion mobility spectrometry to resolve ambiguities regarding the strand stoichiometry, or separate and characterise different structural isomers. We also describe that adding electrospray-compatible organic co-solvents (methanol, ethanol, isopropanol or acetonitrile) to aqueous ammonium acetate increases the stability and rate of formation of dimeric G-quadruplexes, and causes structural transitions to parallel structures. Structural changes were probed by circular dichroism and ion mobility spectrometry, and the excellent correlation between the two techniques validates the use of ion mobility to investigate G-quadruplex folding. We also demonstrate that parallel G-quadruplex structures are easier to preserve in the gas phase than antiparallel structures. [less ▲]

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See detailMass spectrometry applied to biomolecules analysis
Far, Johann ULg; Mazzucchelli, Gabriel ULg; Meuwis, Marie-Alice ULg et al

Conference (2011, March 31)

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See detailMass spectrometry as a tool to search specific ligands for G protein coupled receptors.
Cologna, Camila Takeno; Echterbille, Julien ULg; De Pauw, Edwin ULg et al

Conference (2012)

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See detailMass spectrometry as an evolutive tool for toxinology: from sequencing to toxin shapes
Quinton, Loïc ULg; Gilles, Nicolas; Echterbille, Julien ULg et al

Conference (2011, September 12)

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See detailMass spectrometry imaging is moving toward drug protein co-localization
Ait-Belkacem, Rima; Sellami, Lyna; Villard, Claude et al

in Trends in Biotechnology (2012), 30(9), 466-474

Mass spectrometry (MS)-based technology provides label-free localization of molecules in tissue samples. Drugs, proteins, lipids and metabolites can easily be monitored in their environment. Resolution ... [more ▼]

Mass spectrometry (MS)-based technology provides label-free localization of molecules in tissue samples. Drugs, proteins, lipids and metabolites can easily be monitored in their environment. Resolution can be achieved down to the cellular level (10–20 mm) for conventional matrix-assisted laser desorption/ionization (MALDI) imaging, or even to the subcellular level for more complex technologies such as secondary ionization mass spectrometry (SIMS) imaging. One question remains: are we going to be able to investigate functional relationships between drugs and proteins and compare with localized phenomena? This review describes the various spatial levels of investigation offered by mass spectrometry imaging (MSI), and the advantages and disadvantages compared with other labeling technologies. [less ▲]

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See detailMass spectrometry imaging of rat brain sections: nanomolar sensitivity with MALDI versus nanometer resolution by TOF–SIMS
Benabdellah, Farida; Seyer, Alexandre; Quinton, Loïc ULg et al

in Analytical and Bioanalytical Chemistry (2010), 396(1), 151-162

Mass spectrometry imaging is becoming a more and more widely used method for chemical mapping of organic and inorganic compounds from various surfaces, especially tissue sections. Two main different ... [more ▼]

Mass spectrometry imaging is becoming a more and more widely used method for chemical mapping of organic and inorganic compounds from various surfaces, especially tissue sections. Two main different techniques are now available: matrix-assisted laser desorption/ionizaton, where the sample, preliminary coated by an organic matrix, is analyzed by a UV laser beam; and secondary ion mass spectrometry, for which the target is directly submitted to a focused ion beam. Both techniques revealed excellent performances for lipid mapping of tissue surfaces. This article will discuss similarities, differences, and specificities of ion images generated by these two techniques in terms of sample preparation, sensitivity, ultimate spatial resolution, and structural analysis. [less ▲]

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See detailMass Spectrometry lab activities in Liege - Small molecules
Focant, Jean-François ULg

Scientific conference (2012, March)

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See detailMass spectrometry of G-quadruplexes
Gabelica, Valérie ULg

Conference (2010, May 31)

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See detailMass transfer in low-density xerogel catalysts
Heinrichs, Benoît ULg; Pirard, Jean-Paul ULg; Schoebrechts, Jean-Paul

in AIChE Journal (2001), 47(8), 1866-1873

Texture and morphology of a Pd-Ag/SiO2 hydrodechlorination low-density xerogel catalyst prepared by a cogelation sot-gel process were characterized in detail to examine mass transfer in such catalysts ... [more ▼]

Texture and morphology of a Pd-Ag/SiO2 hydrodechlorination low-density xerogel catalyst prepared by a cogelation sot-gel process were characterized in detail to examine mass transfer in such catalysts. The catalyst consists of active Pd-Ag nanocrystallites trapped inside elementary 20 nm microporous silica particles arranged in larger aggregates, which constitute the macroscopic pellet. To reach active sites, reactants must first diffuse through large pores located between aggregates of SiO2 Particles and then through smaller pores located between those elementary particles inside the aggregates. Finally, they, diffuse through micropores located inside silica particles. Diffusion in such a "funnel" structure cannot be described assimilating the pellet to a pseudo-continuum. Diffusion should be examined carefully at three levels of decreasing size: the macroscopic pellet, the aggregate of silica particles, and the elementary silica particle. This approach shows that cogelled xerogel catalysts have remarkable mass-transfer properties. [less ▲]

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See detailMass transfer, mixing and gas hold-up in a circulating jet-loop nitrifying MBR
Kouakou, Edouard; Salmon, Thierry ULg; Toye, Dominique ULg et al

in Proceedings of 7th World Congress of Chemical Enginnering - WCCE7, Glasgow, Scotland, 10-14 July 2005 (2005)

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See detailMass transport in carbon gels with tuned porosity
Job, Nathalie ULg

in Spanish Carbon Group Bulletin (2012)

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See detailMass-murder deletion of 19 Orfs from Saccharomyces cerevisiae chromosome XI
Vandenbol, Micheline ULg; Fairhead, C.

in Gene (2000), 247(1-2),

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See detailLe Massacre des innocents dans un village flamand. Lecture d'un tableau mutilé de Pierre Bruegel l'Ancien
Allart, Dominique ULg

Conference given outside the academic context (2013)

La Renaissance prend des accents inattendus avec Pierre Bruegel l’Ancien. A contre-courant des goûts antiquisants et italianisants, l’artiste exalta les traditions spécifiques de son pays natal et réalisa ... [more ▼]

La Renaissance prend des accents inattendus avec Pierre Bruegel l’Ancien. A contre-courant des goûts antiquisants et italianisants, l’artiste exalta les traditions spécifiques de son pays natal et réalisa ainsi des œuvres originales, parfois déroutantes. Tandis que les Pays-Bas espagnols s’enfonçaient dans la guerre civile, Bruegel peignit une version insolite du Massacre des innocents, où il situait l’épisode biblique dans un village flamand et le traitait comme une scène d’actualité. Si ce chef-d’œuvre nous est parvenu fort altéré suite à des restaurations anciennes, nous pouvons en restituer l’apparence initiale grâce aux copies très fidèles qu’en réalisa plus tard le fils aîné de Bruegel, Pierre dit le Jeune. Nous découvrons ainsi toute l’audace dont fit preuve un artiste en vue, prisé dans les hautes sphères du pouvoir, jouant sur l’ambiguïté et le double sens pour exposer des positions subversives dans un contexte de répression politique sans merci. [less ▲]

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See detailLe Massacre des Innocents de Pierre Brueghel le Jeune de la collection Brukenthal (Bucarest) : Une copie qui fait honneur à son modèle
Allart, Dominique ULg; Currie, Christina ULg; Saverwyns, Steven

in Bulletin de l'Institut Royal du Patrimoine Artistique = Bulletijn van het Koninklijk Instituut voor het Kunstpatrimonium (2013)

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See detailLe massage corporel selon Tiffany Field
Battisti, Oreste ULg

Learning material (2012)

Le massage corporel bien conduit permet la synthèse corporelle; il est indiqué en période néonatale chez le bébé issu dans un contexte de pharmacodépendance (drogues illicites ou licites) et permet de ... [more ▼]

Le massage corporel bien conduit permet la synthèse corporelle; il est indiqué en période néonatale chez le bébé issu dans un contexte de pharmacodépendance (drogues illicites ou licites) et permet de réduire les médications sédatives (phénobarbital, morphine). [less ▲]

Detailed reference viewed: 67 (4 ULg)