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10 results on '"Guignard, Nadia"'

1. One MAX phase, different MXenes: a guideline to understand the crucial role of etching conditions on Ti$_3$C$_2$T$_x$ surface chemistry

Author

Benchakar, Mohamed, Loupias, Lola, Garnero, Cyril, Bilyk, Thomas, Morais, Claudia, Canaff, Christine, Guignard, Nadia, Morisset, Sophie, Pazniak, Hanna, Hurand, Simon, Chartier, Patrick, Pacaud, Jérôme, Mauchamp, Vincent, Barsoum, Michel, Habrioux, Aurélien, and Celerier, Stephane

Subjects
Condensed Matter - Materials Science
Abstract

MXenes are a new, and growing, family of 2D materials with very promising properties for a wide variety of applications. Obtained from the etching of MAX phases, numerous properties can be targeted thanks to the chemical richness of the precursors. Herein, we highlight how etching agents govern surface chemistries of Ti$_3$C$_2$T$_x$, the most widely studied MXene to date. By combining characterization tools such as X-ray diffraction, X-ray photoelectron, Raman and electron energy loss spectroscopies, scanning and transmission electron microscopies and a surface sensitive electrochemical reaction-the hydrogen evolution reaction, HER-we clearly demonstrate that the etching agent (HF, LiF/HCl or FeF$_3$/HCl) strongly modifies the nature of surface terminal groups (F, OH and/or O), oxidation sensitivity, delamination ability, nature of the inserted species, interstratification, concentration of defects and size of flakes. Beyond showing how using these different characterization tools to analyze MXenes, this work highlights that the MXene synthesis routes can influence targeted applications.

Published
2020
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5. Regeneration of an Aged Hydrodesulfurization Catalyst by Non-Thermal Plasma: Characterization of Refractory Coke Molecules

Author

Hamieh, Tayssir, Hamieh, Tayssir, Srour, Hawraa, Guignard, Nadia, Tarighi, Mehrad, Devers, Elodie, Mekki-Berrada, Adrien, Toufaily, Joumana, Batiot-Dupeyrat, Catherine, Pinard, Ludivic, Hamieh, Tayssir, Hamieh, Tayssir, Srour, Hawraa, Guignard, Nadia, Tarighi, Mehrad, Devers, Elodie, Mekki-Berrada, Adrien, Toufaily, Joumana, Batiot-Dupeyrat, Catherine, and Pinard, Ludivic

Abstract

This study describes the phenomena involved during the regeneration of an aged industrial hydrodesulfurization catalyst (CoMoP/Al2O3) using a non-thermal plasma at a low temperature (200 °C). The changes occurring during regeneration were studied by characterizing spent, partially, and fully regenerated catalysts by XRD, Raman, TEM spectroscopy, and the coke deposited on the catalyst surface by Laser desorption/ionization time-of-flight mass spectrometry (LDI TOF/MS). The coke is a mixture of several polycyclic molecules, the heaviest with a coronene backbone, containing up to seven sulfur atoms. This kinetic study shows that the oxidation rate depends on the nature of the coke. Hence, explaining the formation of VOCs from heavy polycyclic carbon molecules without complete oxidation to CO2. However, XRD and Raman spectroscopies evidence CoMoO4 formation after a long treatment time, indicating hot spots during the regeneration.

Published
2021

6. Impact of operation conditions, foulant adsorption, and chemical cleaning on the nanomechanical properties of ultrafiltration hollow fiber membranes

Author

Allavena, Audrey, Liu, Sylvie, Ribette, Thomas, Abou Mrad, Ninette, Chiavassa, Thierry, Le Sergeant d’Hendecourt, Louis, Sternberg, Robert, Danger, Grégoire, Eddhif, Balkis, Lange, Justin, Guignard, Nadia, Batonneau, Yann, Clarhaut, Jonathan, Papot, Sébastien, Geffroy-Rodier, Claude, Poinot, Pauline, Gutierrez, Leonardo, Keucken, Alexander, Aubry, Cyril, Zaouri, Noor, Teychene, Benoit, Croué, Jean-Philippe, Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Bioélectrochimie et Analyse du Milieu (LABAM), Université Paris-Est Marne-la-Vallée (UPEM)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de catalyse en chimie organique (LACCO), Université de Poitiers-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), INSERM CIC 0802 (INSERM - CHU de Poitiers), Université de Poitiers-Centre hospitalier universitaire de Poitiers (CHU Poitiers)-Institut National de la Santé et de la Recherche Médicale (INSERM), Synthèse Organique (E5), Université de Poitiers-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Curtin University [Perth], and Planning and Transport Research Centre (PATREC)

Subjects
Materials science, Fouling, Water development, Ultrafiltration, [CHIM.CATA]Chemical Sciences/Catalysis, 02 engineering and technology, 010501 environmental sciences, 021001 nanoscience & nanotechnology, Chemical cleaning, 01 natural sciences, 6. Clean water, Colloid and Surface Chemistry, Adsorption, Membrane, Chemical engineering, Wastewater, Fiber, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

The financial support of the GenoMembran-project funded by The Swedish Water and Wastewater Association (Swedish Water Development, SVU), Norrvatten, and VIVAB is gratefully acknowledged. Pentair X-Flow is acknowledged for the provision of various test modules and general membrane investigations.

Published
2018
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7. Role of the microtubule-associated TPPP/p25 in Parkinson’s and related diseases and its therapeutic potential

Author

Gonçalves, Vinicius O.O., Ciotonea, Carmen, Arrii-Clacens, Sandrine, Guignard, Nadia, Roudaut, Christelle, Rousseau, Julie, Clacens, Jean-Marc, Royer, Sebastien, Richard, Frédéric, Oláh, Judit, Bertrand, Philippe, Ovadi, Judit, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut de Chimie du CNRS (INC), Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, Centre Technique des Applications du Soudage (CTAS), Air Liquide [Siège Social], Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institute of Enzymology [Budapest], Research Centre for Natural Sciences, Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Université de Poitiers-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE)

Subjects
0301 basic medicine, Multiple Sclerosis, Drug target, Nerve Tissue Proteins, Disease, Biology, Biochemistry, 03 medical and health sciences, 0302 clinical medicine, Microtubule, medicine, Humans, Molecular Biology, ComputingMilieux_MISCELLANEOUS, Cell Proliferation, Neurons, Regulation of gene expression, Synucleinopathies, Multiple sclerosis, Brain, Cancer, Parkinson Disease, Glioma, [CHIM.CATA]Chemical Sciences/Catalysis, Multiple System Atrophy, medicine.disease, female genital diseases and pregnancy complications, eye diseases, 3. Good health, Oligodendroglia, 030104 developmental biology, Gene Expression Regulation, Cancer development, Neuroscience, 030217 neurology & neurosurgery
Abstract

The discovery and development of therapeutic strategies for the treatments of Parkinson's disease (PD) and other synucleinopathies are limited by a lack of understanding of the pathomechanisms and their connection with different diseases such as cancers. Areas covered: The hallmarks of these diseases are frequently multifunctional disordered proteins displaying moonlighting and/or chameleon features, which are challenging drug targets. A representative of these proteins is the disordered Tubulin Polymerization Promoting Protein (TPPP/p25) expressed specifically in oligodendrocytes (OLGs) in normal brain. Its non-physiological level is tightly related to the etiology of PD and Multiple System Atrophy (TPPP/p25 enrichment in inclusions of neurons and OLGs, respectively), multiple sclerosis (TPPP/p25-positive OLG destruction), as well as glioma (loss of TPPP/p25 expression). The established anti-proliferative potency of TPPP/p25 may raise its influence in cancer development. The recognition that whereas too much TPPP/p25 could kill neurons in PD, but its loss keeps cells alive in cancer could contribute to our understanding of the interrelationship of 'TPPP/p25 diseases'. Expert commentary: The knowledge accumulated so far underlines the key roles of the multifunctional TPPP/p25 in both physiological and diverse pathological processes, consequently its validation as drug target sorely needs a new innovative strategy that is briefly reviewed here.

Published
2017
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10. 1H-NMR-Based Metabolic Profiling of Maternal and Umbilical Cord Blood Indicates Altered Materno-Foetal Nutrient Exchange in Preterm Infants.

Author

Tea, Illa, Le Gall, Gwénaëlle, Küster, Alice, Guignard, Nadia, Alexandre-Gouabau, Marie-Cé cile, Darmaun, Dominique, and Robins, Richard J.

Subjects
FETAL development, METABOLISM, NUCLEAR magnetic resonance spectroscopy, PREMATURE infants, UMBILICAL veins, PRINCIPAL components analysis
Abstract

Background: Adequate foetal growth is primarily determined by nutrient availability, which is dependent on placental nutrient transport and foetal metabolism. We have used 1H nuclear magnetic resonance (NMR) spectroscopy to probe the metabolic adaptations associated with premature birth. Methodology: The metabolic profile in 1H NMR spectra of plasma taken immediately after birth from umbilical vein, umbilical artery and maternal blood were recorded for mothers delivering very-low-birth-weight (VLBW) or normo-ponderal full-term (FT) neonates. Principal Findings: Clear distinctions between maternal and cord plasma of all samples were observed by principal component analysis (PCA). Levels of amino acids, glucose, and albumin-lysyl in cord plasma exceeded those in maternal plasma, whereas lipoproteins (notably low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) and lipid levels were lower in cord plasma from both VLBW and FT neonates. The metabolic signature of mothers delivering VLBW infants included decreased levels of acetate and increased levels of lipids, pyruvate, glutamine, valine and threonine. Decreased levels of lipoproteins glucose, pyruvate and albumin-lysyl and increased levels of glutamine were characteristic of cord blood (both arterial and venous) from VLBW infants, along with a decrease in levels of several amino acids in arterial cord blood. Conclusion: These results show that, because of its characteristics and simple non-invasive mode of collection, cord plasma is particularly suited for metabolomic analysis even in VLBW infants and provides new insights into the materno-foetal nutrient exchange in preterm infants. [ABSTRACT FROM AUTHOR]

Published
2012
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