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L'hybridité vue à partir du sujet : le cas du musicien franco-malgache Charles Kely Zana-Rotsy
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Variable speed induction motors’ fault detection based on transient motor current signatures analysis: A review
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Devenir des microplastiques dans les sols – quels indicateurs des sources, teneurs et impacts pour la qualité et la santé des sols ? (Projet PlastiSol)
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Insights into the Electronic Properties of Coumarins: A Comparative Study Synthesis, Characterization, and Theoretical Study of New Peptides Obtained by Opening Reactions of Sulfahydantoins
No full textInternational audienceSulfhydantoin from glycine or L-valine is used as a precursor via heterocyclic opening reactions. The operating conditions used during electrophilicity tests influence the reactivity of heterocycles, the best control of the electrophilicity of our molecules, and consider as well as their use as enzyme inhibitors. The regioselectivity of the reactions carried out in various nucleophilic media leads to three new linear products derived from acetamide and butanamide and which are analogous to the peptide structures. The structures of the synthesized products 3-5 have been elucidated and confirmed by the usual spectroscopic methods. A theoretical study based on the DFT/PW6B95 method combined with the basic set 6-311G (2d,p) was carried out to determine the structural and electronic parameters such as the energy parameters, the molecular electrostatic potential (MEP), the natural bonding of orbitals (NBO), non-covalent interactions (NCI) and 1 H NMR. Sulfhydantoin from glycine or L-valine is used as a precursor via heterocyclic opening reactions. The operating conditions used during electrophilicity tests influence the reactivity of heterocycles, the best control of the electrophilicity of our molecules, and consider as well as their use as enzyme inhibitors. The regioselectivity of the reactions carried out in various nucleophilic media leads to three new linear products derived from acetamide and butanamide and which are analogous to the peptide structures. The structures of the synthesized products 3-5 have been elucidated and confirmed by the usual spectroscopic methods. A theoretical study based on the DFT/PW6B95 method combined with the basic set 6-311G (2d,p) was carried out to determine the structural and electronic parameters such as the energy parameters, the molecular electrostatic potential (MEP), the natural bonding of orbitals (NBO), non-covalent interactions (NCI) and 1 H NMR
Chapter 4- Taste and trigeminal perception; from detection to integration
No full textInternational audienceTaste is crucial for the sensory evaluation of food. This sense allows the detection of essential nutrients and toxic compounds. Human beings are able to discriminate five primary different taste qualities, sweet, umami (the taste of amino acids), bitter, salty, and sour. Tasting compounds are remarkably diverse chemically. They activate specialized detectors expressed in the oral cavity. In this chapter, we review the main tasting molecules known to generate these five tastes and trigeminal compounds. This chapter describes also the current knowledge on the physiology of taste, the integration of taste perception, and how taste-taste interaction occurs at the brain level
Breakups of Chitosan microcapsules in extensional flow
No full textInternational audienceThe controlled rupture of a core-shell capsule and the timely release of encapsulated materials are essential steps of the efficient design of such carriers. The mechanical and physico-chemical properties of their shells (or membranes) mainly govern the evolution of such systems under stress and notably the link between the dynamics of rupture and the mechanical properties. This issue is addressed considering weakly cohesive shells made by the interfacial complexation of Chitosan and PFacid in a planar extensional flow. Three regimes are observed, thanks to the two observational planes. Whatever the time of reaction in membrane assembly, there is no rupture in deformation as long as the hydrodynamic stress is below a critical value. At low times of complexation (weak shear elastic modulus), the rupture is reminiscent of the breakup of droplets: a dumbell or a waist. Fluorescent labelling of the membrane shows that this process is governed by continuous thinning of the membrane up to the destabilization. It is likely that the membrane shows a transition from a solid to liquid state. At longer times of complexation, the rupture has a feature of solid-like breakup (breakage) with a discontinuity of the membrane. The maximal internal constraint determined numerically marks the initial location of breakup as shown. The pattern becomes more complex as the elongation rate increases with several points of rupture. A phase diagram in the space parameters of the shear elastic modulus and the hydrodynamic stress is established
Boron-doped carbon nanowalls for fast and direct detection of cytochrome C and ricin by matrix-free laser desorption/ionization mass spectrometry
No full textInternational audienceDetecting proteins via surface assisted laser desorption/ionization mass spectrometry (SALDI-MS) method is still highly challenging, and only few examples of nanomaterials have been demonstrated to perform such detection so far. In this study, carbon nanowalls (CNWs), vertically aligned graphene sheet-based materials, presenting specific morphology, dimensions, and boron doping levels have shown improved performances for both qualitative and quantitative detection of Cytochrome C under optimized experimental conditions. Boron doped carbon nanowalls (B-CNWs) with a [B]/[C] ratio of 5000 ppm and growing time of 4 h have shown the best performance in terms of signal intensity and reliability. Then, the detection of ricin, a ribosomal-inhibiting protein (RIP) classified as category B bioterrorism agent by CDC (Centre of Disease and Control and Prevention), was performed. For the first time, direct SALDI-MS detection of ricin B chain was reported without tedious sample preparation steps or database interrogation, and results were obtained within few minutes and a limit of detection (LOD) of 0.5 pmol/μl was obtained. Thanks to the introduction of galactosamine residues on B–CNW, we were able to selectively detect ricin B chain protein in complex media such as serum and soft drinks with enhanced signal intensity. B-CNWs are not toxic and are adaptable to any commercial MALDI-TOF mass spectrometer, showing their great potential as SALDI based materials
Penser les formes filmiques contemporaines
No full textInternational audienceComment penser les formes filmiques contemporaines dans un monde éminemment complexifié, à l’ère d’une mondialisation débridée, où la circulation des images n’a jamais été aussi massive et rapide ? C’est un véritable défi pour l’analyste des images, qui peut lui-même se dire contemporain à la seule condition d’être « celui qui perçoit l’obscurité de son temps comme une affaire qui le regarde et n’a de cesse de l’interpeller », selon le philosophe Giorgio Agamben. Articulée autour de quatre hypothèses de travail – Temporalités contrariées ; Mémoires stratifiées ; Espaces reconfigurés ; Mondes partagés – la réflexion collective menée ici interroge à la fois la manière dont les formes filmiques contemporaines pensent et analysent le monde, et comment elles suscitent en retour l’invention de nouveaux gestes, méthodes, postures, techniques, stratégies et outils analytiques afin de continuer à penser avec exigence les images et les œuvres d’aujourd’hui