Targeted Deletion of Kcne2 Causes Gastritis Cystica Profunda and Gastric Neoplasia

Gastric cancer is the second leading cause of cancer death worldwide. Predisposing factors include achlorhydria, Helicobacter pylori infection, oxyntic atrophy and TFF2-expressing metaplasia. In parietal cells, apical potassium channels comprising the KCNQ1 α subunit and the KCNE2 β subunit provide a K+ efflux current to facilitate gastric acid secretion by the apical H+K+ATPase. Accordingly, genetic deletion of murine Kcnq1 or Kcne2 impairs gastric acid secretion. Other evidence has suggested a role for KCNE2 in human gastric cancer cell proliferation, independent of its role in gastric acidification. Here, we demonstrate that 1-year-old Kcne2−/− mice in a pathogen-free environment all exhibit a severe gastric preneoplastic phenotype comprising gastritis cystica profunda, 6-fold increased stomach mass, increased Ki67 and nuclear Cyclin D1 expression, and TFF2- and cytokeratin 7-expressing metaplasia. Some Kcne2−/−mice also exhibited pyloric polypoid adenomas extending into the duodenum, and neoplastic invasion of thin walled vessels in the sub-mucosa. Finally, analysis of human gastric cancer tissue indicated reduced parietal cell KCNE2 expression. Together with previous findings, the results suggest KCNE2 disruption as a possible risk factor for gastric neoplasia

Colitis in tropical regions

L'étiologie des colites en zones tropicales a «évolué» depuis «l'épidémie» de sida. A côté des étiologies classiques - dominées par l'amibiase et la bilharioze - les infections liées au sida sont responsables de diarrhée souvent profuse. Le diagnostic est basé lorsque les examens de selles sont négatifs sur l'endoscopie digestive avec biopsies. Quant aux colites cryptogénétiques inflammatoires, elles restent rares en zones tropicales, mais la rectocolite hémorragique, souvent surinfectée, doit être évoquée si le traitement anti-infectieux est sans résultat

Simultaneous DAFS and XAFS analyses to evidence the Y- and Ti-species in nano-structured ODS steels

International audienceTo characterize the microstructure of neutron irradiated materials, various experimental tools are available at the present time in nuclear environment:SEM, TEM, APT, RBS and NRA… However, these techniques are local probes and bring information for an extremely limited sample volume which could be not representative of the whole volume. Therefore, a good statistic can only be obtained by performing many examinations which are very time consuming

Les propositions subordonnées conjonctives circonstancielles dans la Tétralogie de Blaise Cendrars

L'objet de ce travail de recherches est d'étudier les propositions subordonnées conjonctives circonstancielles en français contemporain dans l'ensemble livresque de Blaise Cendrars, la Tétralogie. Il s'agit d'analyser à travers les différents récits composant cette oeuvre, à partir de la phrase trés spécifique de cendrars, le mécanisme de la subordination dans ces propositions subordonnées. L'étude porte sur les multiples subordonnants qui peuvent introduire ces propositions, sur la structure des phrases complexes auxquelles elles appartiennent, mais aussi sur leur place par rapport à la proposition principale selon les nuances qu'elles expriment et le mode de leur verbe. ce travail est composé de sept chapitres correspondant aux sept propositions subordonnées conjonctives circonstancielles traditionnellement reconnues: les propositions subordonnées temporelle, concessive, hypothétique, causale, consécutive, finale et comparative. Nous procédons tout d'abord à une analyse syntaxico-sémantique de ces diverses propositions et de leur subordonnants et aussi de leur place dans le style cendrarsien. Puis nous nous employons à cerner leurs emplois et leur rôle dans la Tétralogie de Cendrars à partir notamment de leur fréquence dans cette oeuvre. Enfin, nous évaluons l'importance qu'elles revêtent pour leur auteur dans son écriture et dans le développement de ses phrases.The purpose of this researchis to study the circumstantial conjunctive subordinate clauses in contemporary French in Blaise Cendrars' set, the Tétralogie. The mecanism of subordination in these subordinate clauses is analysed through the various accounts composing this work, starting from the very specific sentence of Cendrars. The study focuses on the numerous subordinating conjunctions which introduce those clauses, on the structure of the sentences they belong to, but also on their order in relation to the main clause according to nuances they express and the mode of their verb. This work is composed of seven chapters corresponding to the seven circumstancial conjunctive subordinate clauses, traditionally recognized as temporal, concessive, hypothetical, causal, consecutive, final and of their order in Cendrars's style. Then we work on determining their us and function in the Cendrars' Tétralogie from their frequency in these books. Lastly, their importance on Cendrars' writing is analysed to determine their impact on the way his sentences are developed.PARIS4-BU Serpente (751052129) / SudocSudocFranceF

Les trois accents graphiques utilisés dans la transcription du français (de la Renaissance à nos jours, à travers l'étude des dictionnaires de l'Académie française)

La langue française utilise, dans sa forme écrite, des accents : aigus, graves et circonflexes. Ces petites marques graphiques ont connu de nombreuses péripéties avant de s'imposer dans notre orthographe. Elles ont occupé des emplois divers, inspirés de leur usage chez les grammairiens grecs et latins. Puis l'Académie française les a progressivement intégrées dans ses Dictionnaires et chacune d'elles s'est vue attribuer un ou plusieurs rôles spécifiques. Or, à notre époque, les accents semblent en voie de disparition non seulement dans l'écriture manuscrite mais également sur les imprimés ou les écrans. L'auteur de ce travail a voulu essayer de comprendre pourquoi les accents étaient négligés, oubliés, déformés. Il constate que de nombreux Français ressentent un réel attachement pour ces signes qui, tout en conservant un rôle phonogrammique souvent important, sont aussi des traces du passé qui nous racontent la longue aventure d'un mot.The French language uses, in its written shape, acute, grave and circumflex accents. These small graphic symbols knew numerous events before prevailing in our spelling. They occupied different uses, inspired by their usage with Greek and Latin grammarians. Then the French Academy gradually integrated them into its dictionaries and each of them was attributed one or several specific roles. Nowadays, accents seem to be in the process of disappearance, not only in handwriting but also on printed documents or screens. The author of this work wanted to try to understand why accents were neglected, forgotten or deformed. He notices that French people have a real affection for these signs which, while preserving an important phonetic role, are also remnants that tell us the long adventure of a word.PARIS4-BU Serpente (751052129) / SudocSudocFranceF

Characterizations with the MARS beamline (synchrotron SOLEIL) of materials irradiated in nuclear reactors

International audienceMARS (Multi-Analyses on Radioactive Samples) is the X-ray bending magnet beamline of the French synchrotron facility SOLEIL dedicated to the study of radioactive matter. The MARS beamline aims at extending the possibilities of synchrotron based X-ray characterizations towards a wider variety of radioactive elements (et61537;et61484;et61472;et61538;et61484;et61472;et61543; and n emitters). Thus, its specific and innovative infrastructure has been optimized to carry out analyses on radioactive materials with activities up to 18.5 GBq per sample. This beamline, which has been built thanks to a close partnership and support by the CEA, has been designed to provide X-rays in the energy range of 3.5 keV to 35 keV. Three main techniques are progressively proposed on MARS beamline transmission and high-resolution powder X-ray diffraction (respectively T-XRD and HR-XRD), X-ray absorption spectroscopy (XAS) and X-ray fluorescence (XRF).After the preliminary experiences performed on un-irradiated samples, this presentation deals with recent results obtained on the MARS beamline, thanks to very powerful and useful improvements brought to the experimental set-up of the beamline and to various materials irradiated in nuclear reactors Oxide dispersion-strengthened (ODS) steels at high doses and also Zr based alloys irradiated in Pressurized Water Reactors up to 7 PWR cycles.Results concerning secondary phases evolutions as a function of irradiation doses for both ODS and Zr based alloys will be presented using XRD, but also experiences using XAS especially on ODS will be given.Finally, future prospects and main objectives concerning the evolution of the beamline and studies on irradiated materials will be discussed

INVESTIGATION OF NEUTRON RADIATION EFFECTS ON THE MECHANICAL BEHAVIOR OF RECRYSTALLIZED ZIRCONIUM ALLOYS

International audienceNeutron radiation induces important changes in the mechanical behavior of recrystallized zirconium alloys used as fuel cladding tube. The neutron radiation effects on the mechanical behavior for internal pressure test performed at 350DC have been investigated using a specific analysis in terms of isotropic hardening, kinematic hardening and viscous stress. The impact of irradiation has been interpreted in terms of microscopic deformation mechanisms observed by Transmission Electron Microscopy (TEM). It is proposed that because of the localization of the plastic deformation inside channels and because of the only activation of basal channeling, the kinematic hardening must be strong in irradiated zirconium alloys. A simple unified phenomenological modeling is also used in order to have a coherent description of the radiation effects on the mechanical behavior

INVESTIGATION OF NEUTRON RADIATION EFFECTS ON THE MECHANICAL BEHAVIOR OF RECRYSTALLIZED ZIRCONIUM ALLOYS

International audienceNeutron radiation induces important changes in the mechanical behavior of recrystallized zirconium alloys used as fuel cladding tube. The neutron radiation effects on the mechanical behavior for internal pressure test performed at 350DC have been investigated using a specific analysis in terms of isotropic hardening, kinematic hardening and viscous stress. The impact of irradiation has been interpreted in terms of microscopic deformation mechanisms observed by Transmission Electron Microscopy (TEM). It is proposed that because of the localization of the plastic deformation inside channels and because of the only activation of basal channeling, the kinematic hardening must be strong in irradiated zirconium alloys. A simple unified phenomenological modeling is also used in order to have a coherent description of the radiation effects on the mechanical behavior

Investigation on the zirconia phase transition under irradiation

ACEZirconia, ZrO2, produced by the oxidation of zirconium alloys in nuclear reactors, possesses a high stability under neutron irradiation. No amorphisation of yttrium-stabilised zirconia has been observed even at high dpa values (≈100 dpa). In pure monoclinic zirconia, a phase transition monoclinic → cubic (tetragonal) induced by irradiation has already been observed. The aim of this work is to study in detail the mechanism responsible for this transition. For that purpose, different kinds of irradiations with electrons (to study point defects) and low energetic ions (to study clusters due to collision cascades) have been performed on zirconia samples. A local probe (Raman spectroscopy) and a non-local probe (grazing X-ray diffraction) have been used to characterise the phase formed during irradiation, which is clearly the tetragonal phase. For the ionic implantation, the grazing X-ray diffraction permits to separate effects due to the ballistic collisions and the implantation peak. Using this method, it was possible to show that the profile of the tetragonal phase was only linked to the dpa profile. This result associated to the results obtained by the Raman spectroscopy (broadening of Raman peaks) shows that the phase transition may be induced by clusters formed near the collision cascades