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106 results on '"Penhoat M"'

1. First (e,e) coincidence measurements on solvated sodium benzoate in water using a magnetic bottle time-of-flight spectrometer

Author

Huart, L., primary, Fournier, M., additional, Dupuy, R., additional, Vacheresse, R., additional, Mailhiot, M., additional, Cubaynes, D., additional, Céolin, D., additional, Hervé du Penhoat, M. A., additional, Renault, J. P., additional, Guigner, J.-M., additional, Kumar, A., additional, Lutet-Toti, B., additional, Bozek, J., additional, Ismail, I., additional, Journel, L., additional, Lablanquie, P., additional, Penent, F., additional, Nicolas, C., additional, and Palaudoux, J., additional

Published
2023
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2. LASERIX : an open facility for developments of EUV and soft X-ray lasers and applications.

Author

Ros, D., Cassou, K., Cros, B., Daboussi, S., Demailly, J., Guilbaud, O., Jamelot, G., Habib, J., Kazamias, S., Lagron, J.-C., Maynard, G., Neveu, O., Pittman, M., Zielbauer, B., Zimmer, D., Kuehl, T., Bagnoud, V., Delmotte, F., Joyeux, D., De Rossi, S., Klisnick, A., Lacombe, S., Le Sech, C., Porcel, E., du Penhoat, M.-A., Touati, A., Zeitoun, P., Chambaret, J.-P., Mathieu, F., Mourou, G., Lee, Jongmin, editor, Nam, Chang Hee, editor, and Janulewicz, Karol A., editor

Published
2011
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3. Coupling a magnetic bottle multi-electron spectrometer with a liquid micro-jet device:a comprehensive study of solvated sodium benzoate at the O 1 s threshold

Author

Fournier, M. (Marine), Huart, L. (Lucie), Dupuy, R. (Rémi), Vacheresse, R. (Régis), Reinhardt, M. (Maximilian), Cubaynes, D. (Denis), Céolin, D. (Denis), du Penhoat, M. H. (Marie-Anne Hervé), Renault, J.-P. (Jean-Philippe), Guigner, J.-M. (Jean-Michel), Kumar, A. (Ajit), Lutet-Toti, B. (Bastien), Bozek, J. (John), Ismail, I. (Iyas), Journel, L. (Loïc), Lablanquie, P. (Pasca), Penent, F. (Francis), Nicolas, C. (Christophe), Palaudoux, J. (Jérôme), Fournier, M. (Marine), Huart, L. (Lucie), Dupuy, R. (Rémi), Vacheresse, R. (Régis), Reinhardt, M. (Maximilian), Cubaynes, D. (Denis), Céolin, D. (Denis), du Penhoat, M. H. (Marie-Anne Hervé), Renault, J.-P. (Jean-Philippe), Guigner, J.-M. (Jean-Michel), Kumar, A. (Ajit), Lutet-Toti, B. (Bastien), Bozek, J. (John), Ismail, I. (Iyas), Journel, L. (Loïc), Lablanquie, P. (Pasca), Penent, F. (Francis), Nicolas, C. (Christophe), and Palaudoux, J. (Jérôme)

Abstract

We have developed a magnetic bottle time-of-flight electron-electron coincidence spectrometer to perform measurements on solvated molecules in a liquid micro-jet. We present here the first results obtained after ionization of the oxygen 1s inner-shell of sodium benzoate molecules and show the possibilities to filter out the electron signal arising from the liquid phase from the signal of water molecules in the gas phase. Both photoelectrons and Auger electrons spectra (unfiltered and filtered) are presented.

Published
2022

9. Coupling an Electron Time-of-flight Spectrometer and an under Vacuum Liquid Jet for Coincidence Measurements on Solvated Biomolecules

Author

Huart, L., Kumar, A., Penent, F., Ismail, I., Lablanquie, P., Renault, J.P., Hervé Du Penhoat, M.-A., Nicolas, C., Palaudoux, J., Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.MATE]Chemical Sciences/Material chemistry
Abstract

International audience; Radiation damage of biological systems is a complex multi-scale problem, not only in the spatial domain but also in the temporal domain. While interactions start at the atomic level (from atto-to femto-second), they can impact the molecular level (femto-to pico-second) and ultimately affect a cell's behavior over hours or days, culminating, in the worst case, in a full breakdown of a living organism over months to years. Photoelectron spectroscopy constitutes one of the basic experimental methods to study processes initiated by interaction of light with matter. It is widely applied in experiments or photoionization of gaseous, solid, and more recently, in liquid media. The Magnetic Bottle Time-Of-Flight (MB-TOF) is specially designed to study multi-electron processes. Indeed, due to its almost 4$\pi$ electron collection efficiency, it is well suited to studying the early stages of an inner-shell photoionization, via coincidence techniques between the photoelectron and the resulting Auger electrons. Thus, coupled with an under vacuum liquid jet, it allows to investigate the different relaxation pathways of biomolecules in an aqueous media, after being irradiated by soft X-ray radiation. We will present the first results obtained on different solutes and highlight how it is possible to clearly disentangle the liquid phase signal from the signal arising from the surrounding gas phase water. Particular attention will be drawn to non-local energy transfers (between the solute and water molecules) such as interatomic coulombic decay or electron transfer mediated decay.

Published
2020

10. Œdème cyanique chronique douloureux des doigts

Author

Soenen, A., primary, Durant, C., additional, Aubert, H., additional, Guitteny, M., additional, Bougouin, E. Kuhn, additional, Penhoat, M. Gahier, additional, Kassam, D., additional, Bailly, C., additional, and Barbarot, S., additional

Published
2017
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12. Time-dependent density functional theory molecular dynamics simulation of doubly charged uracil in gas phase

Author

López-Tarifa P., Hervé du Penhoat M.-A., Vuilleumier R., Gaigeot M.-P., Rothlisberger U., Tavernelli I., Le Padellec A., Champeaux J.-P., Alcamí M., Moretto-Capelle P., Martín F., Politis M.-F. and This paper was intended for the special issue associated to the annual meeting of the COST Action CM0702 held in Cluj-Napoca, Romania between 21-23 March 2012. This work was performed using HPC resources from Mare Nostrum BSC, CCC-UAM, CCR UPMC and GENCI - CINES/IDRIS grant 2010-085014. We thank the support of the MICINN projects FIS2010-15127, CTQ2010-17006, ACI2008-0777, and CSD 2007-00010, the CAM project S2009/MAT1726, the COST Action CM0702, the Picasso project HF2007-0067, and HPC Europa2. P. López-Tarifa, I. Tavernelli and U. Röthlisberger also acknowledge the Swiss NSF through the NCCR MUST interdisciplinary research program. P. López-Tarifa also thanks the FP7 Marie Curie COFUND Action.

Published
2014

16. Time-dependent density functional theory molecular dynamics simulation of doubly charged uracil in gas phase

Author

López-Tarifa P., Hervé du Penhoat M.-A., Vuilleumier R., Gaigeot M.-P., Rothlisberger U., Tavernelli I., Le Padellec A., Champeaux J.-P., Alcamí M., Moretto-Capelle P., Martín, Fernando, Politis M.-F., López-Tarifa P., Hervé du Penhoat M.-A., Vuilleumier R., Gaigeot M.-P., Rothlisberger U., Tavernelli I., Le Padellec A., Champeaux J.-P., Alcamí M., Moretto-Capelle P., Martín, Fernando, and Politis M.-F.

Published
2014

17. Ultrafast nonadiabatic fragmentation dynamics of biomolecules

Author

López-Tarifa P., Piekarski D.G., Rossich E., Du Penhoat M.-A.H., Vuilleumier R., Gaigeot M.-P., Tavernelli I., Politis M.-F., Wang Y., Díaz-Tendero S., Martín, Fernando, Alcamí M., López-Tarifa P., Piekarski D.G., Rossich E., Du Penhoat M.-A.H., Vuilleumier R., Gaigeot M.-P., Tavernelli I., Politis M.-F., Wang Y., Díaz-Tendero S., Martín, Fernando, and Alcamí M.

Published
2014

18. Highly selective and sensitive Hg2+ fluorescent sensors based on a phosphane sulfure derivative

Author

Ha-Thi, M.H., Penhoat, M., Michelet, V., Leray, I., Bardella, Valérie, Laboratoire Charles Friedel, Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.ORGA]Chemical Sciences/Organic chemistry, [CHIM.ORGA] Chemical Sciences/Organic chemistry, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2009

19. Synthesis, Fluorescence, and Two-Photon Absorption of Bidentate Phosphane Oxyde Derivatives – Complexation with Pb2+ and Cd2+ cations

Author

Ha-Thi, M.-H., Penhoat, M., Drouin, D., Blanchard-Desce, M., Michelet, V., Leray, I., Chimie et Photonique Moléculaires (CPM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Synthèses sélective organique et produits naturels (SSOPN), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Barbedor, Catherine, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.ORGA]Chemical Sciences/Organic chemistry, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2008

20. Etude des dommages induits dans l'ADN par irradiation laser X-UV à 21.2nm

Author

Begusova, M., Cassou, K., Chétoui, A., Du Penhoat, M-a Hervé, Eot-Houllier, G., Guilbaud, O., Jamelot, Gérard, Kazamias, S., Klisnick, A., Koslova, M., Polan, J., Prag, A.R, Ros, D., Rus, B., Sage, E., Stisova, V., Stupka, M., Touati, A., Laboratoire d'interaction du rayonnement X avec la matière (LIXAM), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), and Apruzzese, Sylvie

Subjects
[PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], [PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], [PHYS.PHYS.PHYS-ATOM-PH] Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph]
Published
2004

21. DNA irradiation and plasma diagnostic using X-ray lasers. Recent progress and perspectives at LIXAM

Author

Cassou, K., Guilbaud, O., Jamelot, Gérard, Joyeux, Denis, Kazamias, S., Klisnick, A., Phalippou, Daniel, Ros, D., Tang, Hao, Daido, H., Kado, M., Nagashima, K., Nishikino, M., Kishimoto, M., Sukegawa, K., Ishino, M., Koslova, M., Polan, J., Prag, A.R, Rus, B., Chétoui, A., Begusova, M., Eot, G., Sage, E., Stisova, V., Stupka, M., Du Penhoat, M-A Hervé, Touati, A., Laboratoire d'interaction du rayonnement X avec la matière (LIXAM), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Charles Fabry de l'Institut d'Optique / Scop, Laboratoire Charles Fabry de l'Institut d'Optique (LCFIO), and Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph]
Published
2004

22. Damaging DNA using Ne-like zinc soft x-ray laser at 21.2nm

Author

Begusova, M., Cassou, K., Chétoui, A., Du Penhoat, M-a Hervé, Guilbaud, O., Jamelot, Gérard, Kazamias, S., Klisnick, A., Koslova, M., Polan, J., Prag, A.R, Ros, D., Rus, B., Sage, E., Stisova, V., Stupka, M., Touati, A., Eot-Houllier, G., Laboratoire d'interaction du rayonnement X avec la matière (LIXAM), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), and Apruzzese, Sylvie

Subjects
[PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], [PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], [PHYS.PHYS.PHYS-ATOM-PH] Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph]
Published
2004

23. Maladie sérique après traitement par infliximab

Author

Penhoat, M., primary, Graveleau, J., additional, Lestang, E., additional, Trang, C., additional, Katchakourian, L., additional, Masseau, A., additional, Néel, A., additional, Bourreille, A., additional, and Hamidou, M., additional

Published
2013
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25. Ultrafast non-adiabatic fragmentation dynamics of doubly charged uracil in gas and liquid phase

Author

López-Tarifa P., Penhoat M.-A.H.D., Vuilleumier R., Gaigeot M.-P., Tavernelli I., Padellec A.L., Champeaux J.-P., Alcamí M., Moretto-Capelle P., Martín, Fernando, Politis M.-F., López-Tarifa P., Penhoat M.-A.H.D., Vuilleumier R., Gaigeot M.-P., Tavernelli I., Padellec A.L., Champeaux J.-P., Alcamí M., Moretto-Capelle P., Martín, Fernando, and Politis M.-F.

Published
2012

26. Ultrafast nonadiabatic fragmentation dynamics of doubly charged uracil in a gas phase

Author

López-Tarifa P., Hervé Du Penhoat M.-A., Vuilleumier R., Gaigeot M.-P., Tavernelli I., Le Padellec A., Champeaux J.-P., Alcamí M., Moretto-Capelle P., Martín, Fernando, Politis M.-F., López-Tarifa P., Hervé Du Penhoat M.-A., Vuilleumier R., Gaigeot M.-P., Tavernelli I., Le Padellec A., Champeaux J.-P., Alcamí M., Moretto-Capelle P., Martín, Fernando, and Politis M.-F.

Published
2011

27. Distinct expression of interleukin (IL)-36 α, β and γ, their antagonist IL-36Ra and IL-38 in psoriasis, rheumatoid arthritis and Crohn's disease.

Author

Boutet, M.‐A., Bart, G., Penhoat, M., Amiaud, J., Brulin, B., Charrier, C., Morel, F., Lecron, J.‐C., Rolli‐Derkinderen, M., Bourreille, A., Vigne, S., Gabay, C., Palmer, G., Le Goff, B., and Blanchard, F.

Subjects
INTERLEUKINS, PSORIASIS, CROHN'S disease, RHEUMATOID arthritis, MESSENGER RNA
Abstract

Interleukin (IL)-36α, IL-36β and IL-36γ are expressed highly in skin and are involved in the pathogenesis of psoriasis, while the antagonists IL-36Ra or IL-38, another potential IL-36 inhibitor, limit uncontrolled inflammation. The expression and role of IL-36 cytokines in rheumatoid arthritis (RA) and Crohn's disease (CD) is currently debated. Here, we observed that during imiquimod-induced mouse skin inflammation and in human psoriasis, expression of IL-36α, γ and IL-36Ra, but not IL-36β and IL-38 mRNA, was induced and correlated with IL-1β and T helper type 17 (Th17) cytokines (IL-17A, IL-22, IL-23, CCL20). In mice with collagen-induced arthritis and in the synovium of patients with RA, IL-36α, β, γ, IL-36Ra and IL-38 were all elevated and correlated with IL-1β, CCL3, CCL4 and macrophage colony-stimulating factor (M-CSF), but not with Th17 cytokines. In the colon of mice with dextran sulphate sodium-induced colitis and in patients with CD, only IL-36α, γ and IL-38 were induced at relatively low levels and correlated with IL-1β and IL-17A. We suggest that only a minor subgroup of patients with RA (17-29%) or CD (25%) had an elevated IL-36 agonists/antagonists ratio, versus 93% of patients with psoriasis. By immunohistochemistry, IL-36 cytokines were produced by various cell types in skin, synovium and colonic mucosa such as keratinocytes, CD68+ macrophages, dendritic/Langerhans cells and CD79α+ plasma cells. In primary cultures of monocytes or inflammatory macrophages (M1), IL-36β and IL-36Ra were produced constitutively, but IL-36α, γ and IL-38 were produced after lipopolysaccharide stimulation. These distinct expression profiles may help to explain why only subgroups of RA and CD patients have a potentially elevated IL-36 agonists/antagonists ratio. [ABSTRACT FROM AUTHOR]

Published
2016
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32. Ionization of water clusters by fast Highly Charged Ions: Stability, fragmentation, energetics and charge mobility

Author

Legendre, S, primary, Maisonny, R, additional, Capron, M, additional, Bernigaud, V, additional, Cassimi, A, additional, Gervais, B, additional, Grandin, J-P, additional, Huber, B A, additional, Manil, B, additional, Rousseau, P, additional, Tarisien, M, additional, López-Tarifa, P, additional, Politis, M-F, additional, Penhoat, M A Hervé du, additional, Vuilleumier, R, additional, Gaigeot, M-P, additional, Tavernelli, I, additional, Alcamí, M, additional, Martín, F, additional, and Adoui, L, additional

Published
2009
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34. Biological effects induced by low energy x-rays: effects of nanoparticles

Author

Liehn, S., primary, Le Sech, C., additional, Porcel, E., additional, Zielbauer, B., additional, Habib, J., additional, Kazamias, S., additional, Guilbaud, O., additional, Pittman, M., additional, Ros, D., additional, du Penhoat, M.-A. Hervé, additional, Touati, A., additional, Remita, H., additional, and Lacombe, S., additional

Published
2009
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35. Recent progress on the LASERIX facility

Author

Guilbaud, O., primary, Ros, D., additional, Kazamias, S., additional, Zielbauer, B., additional, Habib, J., additional, Pittman, M., additional, Farinet, M., additional, Zimmer, D., additional, Yu, T., additional, Klisnick, A., additional, de Dortan, F., additional, Lacombe, S., additional, Porcel, E., additional, Le Sech, C., additional, du Penhoat, M.-A., additional, Touati, A., additional, Marsi, M., additional, and Joyeux, D., additional

Published
2009
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36. Ionization and fragmentation of water clusters by fast highly charged ions

Author

Adoui, L, primary, Cassimi, A, additional, Gervais, B, additional, Grandin, J-P, additional, Guillaume, L, additional, Maisonny, R, additional, Legendre, S, additional, Tarisien, M, additional, López-Tarifa, P, additional, Politis, M-F, additional, Penhoat, M-A Hervé du, additional, Vuilleumier, R, additional, Gaigeot, M-P, additional, Tavernelli, I, additional, Alcamí, M, additional, and Martín, F, additional

Published
2009
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37. LASERIX : premier bilan du fonctionnement de l'installation

Author

Guilbaud, O., primary, Ros, D., additional, Kazamias, S., additional, Zielbauer, B., additional, Habib, J., additional, Pittman, M., additional, Cassou, K., additional, Plé, F., additional, Farinet, M., additional, Klisnick, A., additional, de Dortan, F., additional, Lacombe, S., additional, Porcel, E., additional, Le Sech, C., additional, du Penhoat, M.-A., additional, Touati, A., additional, Marsi, M., additional, Fajardo, M., additional, Zeitoun, P., additional, and Joyeux, D., additional

Published
2009
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39. Étude des dommages induits dans l'ADN par irradiation laser X-UV à 21.2 nm

Author

Cassou, K., primary, Ros, D., additional, Kazamias, S., additional, Klisnick, A., additional, Jamelot, G., additional, Guilbaud, O., additional, Rus, B., additional, Kozlová, M., additional, Polan, J., additional, Präg, A. R., additional, Stupka, M., additional, Eot-Houllier, G., additional, Sage, E., additional, Begusová, M., additional, Stísová, V., additional, du Penhoat, M.-A.H., additional, Touati, A., additional, and Chétioui, A., additional

Published
2005
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40. Chromosome aberrations and cell inactivation induced in mammalian cells by ultrasoft X‐rays: correlation with the core ionizations in DNA

Author

Gobert, F.‐n., primary, Lamoureux, M., additional, Penhoat, M.‐a. Hervé du, additional, Ricoul, M., additional, Boissière, A., additional, Touati, A., additional, Abel, F., additional, Politis, M.‐f., additional, Fayard, B., additional, Guigner, J. M., additional, Martins, L., additional, Testard, I., additional, Sabatier, L., additional, and Chetioui, A., additional

Published
2004
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42. Cell Inactivation and Double-Strand Breaks: The Role of Core Ionizations, as Probed by Ultrasoft X Rays

Author

Fayard, B., primary, Touati, A., additional, Abel, F., additional, Herve du Penhoat, M. A., additional, Despiney-Bailly, I., additional, Gobert, F., additional, Ricoul, M., additional, L'Hoir, A., additional, Politis, M. F., additional, Hill, M. A., additional, Stevens, D. L., additional, Sabatier, L., additional, Sage, E., additional, Goodhead, D. T., additional, and Chetioui, A., additional

Published
2002
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43. Modeling proton-induced damage on 2-deoxy-D-ribose. Conformational analysis.

Author

Penhoat, M., López-Tarifa, P., Ghose, K., Jeanvoine, Y., Gaigeot, M., Vuilleumier, R., Politis, M., and Bacchus-Montabonel, M.

Subjects
*CANCER treatment, *PROTON therapy, *THERAPEUTIC use of nuclear particles, *FRAGMENTATION reactions, *CHARGE transfer kinetics, *MOLECULAR dynamics
Abstract

Modeling proton-induced damage in biological systems, in particular in DNA building blocks, is of major concern in studies on cancer proton therapy. This is indeed an extremely complex process and analysis of the mechanism at the molecular level is of crucial interest. Such collision reactions of protons on biological targets induce different reactions: excitation and ionization of the biomolecule, fragmentation of the ionized species, and charge transfer from the projectile ion toward the biomolecular target. In order to have an insight into such mechanisms, we have performed a theoretical approach of two of the most important steps, the fragmentation and the charge transfer processes. For that purpose, we have considered collision of protons with isolated 2-deoxy-D-ribose by means of ab-initio molecular dynamics and quantum chemistry molecular methods. The conformation of the sugar moiety has been analyzed and appears to induce important effects, in particular different fragmentation patterns have been pointed out with regard to the conformation, and significant variations of the charge transfer cross sections have been exhibited. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Published
2014
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44. Lethal Effect of Carbon K-Shell Photoionizations in Chinese Hamster V79 Cell Nuclei: Experimental Method and Theoretical Analysis

Author

du Penhoat, M. A. Herve, primary, Fayard, B., additional, Abel, F., additional, Touati, A., additional, Gobert, F., additional, Despiney-Bailly, I., additional, Ricoul, M., additional, Sabatier, L., additional, Stevens, D. L., additional, Hill, M. A., additional, Goodhead, D. T., additional, and Chetioui, A., additional

Published
1999
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46. Radiolysis of Liquid Water at Temperatures up to 300 °C:  A Monte Carlo Simulation Study

Author

Penhoat, M.-A. Herve du, Goulet, T., Frongillo, Y., Fraser, M.-J., Bernat, P., and Jay-Gerin, J.-P.

Abstract

Monte Carlo simulations were performed to calculate the temperature dependence of the primary yields (g-values) of the radical and molecular products of the radiolysis of pure, deaerated liquid water by low linear-energy-transfer (LET) radiation. The early energy deposition was approximated by considering short segments (~100 μm) of 300-MeV proton tracks (corresponding to an average LET of ~0.3 keV/μm). The subsequent nonhomogeneous chemical evolution of the reactive species formed in these tracks was simulated by using the independent reaction times approximation, which has previously been used successfully to model the radiolysis of liquid water at ambient temperature under various conditions. Our calculated g-values for the radiolytic species:  %@mt;sys@%e%@sx@%aq%@be@%-%@sxx@%%@mx@% , OH, H, H2, and H2O2, are presented as a function of temperature over the range 25−300 °C. They show an increase in g(%@mt;sys@%e%@sx@%aq%@be@%-%@sxx@%%@mx@% ), g(OH), and [g(H) + g(H2)] and a decrease in g(H2O2) with increasing temperature, in agreement with existing experimental data. The sensitivity of the results to the values of reaction rate constants and to the temperature dependence of electron thermalization distances (rth) was also investigated. It was found that the best agreement with experiment occurs when the distances of electron thermalization decrease with increasing temperature, a result that is at variance with the predictions of previous modeling studies. Such a decrease in rth as the temperature increases could be linked to an increase in the scattering cross sections of subexcitation electrons that would account for the corresponding decrease in the degree of structural order of water molecules. Our simulations also suggest that the variations of the g-values with temperature, and especially that of g(H2), are better described if we account for the screening of the Coulomb forces between the two %@mt;sys@%e%@sx@%aq%@be@%-%@sxx@%%@mx@% in the bimolecular self-reaction of the hydrated electron. Finally, the time-dependent yields of %@mt;sys@%e%@sx@%aq%@be@%-%@sxx@%%@mx@% and OH are presented as functions of temperature, in the range 10-12−10-6 s. It was found that the temporal variation of g(%@mt;sys@%e%@sx@%aq%@be@%-%@sxx@%%@mx@% ) at elevated temperatures is sensitive to the temperature dependence of rth, suggesting that measurements of the decay of hydrated electrons as functions of time and temperature could, in turn, provide information on the thermalization of subexcitation electrons. The good overall accord of our calculated results with the experimental data available from the literature demonstrates that Monte Carlo simulation methods offer a most promising avenue at present to further develop our understanding of temperature effects in the radiolysis of liquid water.

Published
2000

50. Multiple wavelength (365-475 nm) complete actinometric characterization of Corning ® Lab Photo Reactor using azobenzene as a highly soluble, cheap and robust chemical actinometer.

Author

Roseau M, Chausset-Boissarie L, Gremetz S, Roth PMC, and Penhoat M

Subjects
Azo Compounds chemistry, Photons
Abstract

The characterization of commercially available Corning ® Lab Photo Reactor by actinometry at different wavelengths (365, 385, 405 and 475 nm) using azobenzene E ↔ Z photoisomerization is reported. By comparison with photon fluxes determined externally using a radiometer, this method based on NMR spectroscopy is rapid, cheap, robust, reproducible and can applied to UVA-visible range, compared to previously described chemical actinometric protocols. Recalculation of isatin N 2 -phenylhydrazone isomerization quantum yield at 405 nm gave almost the same value as the literature data ([Formula: see text] = 0.0013) and confirmed the robustness and applicability of this methodology., (© 2022. The Author(s), under exclusive licence to European Photochemistry Association, European Society for Photobiology.)

Published
2022
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