A temperature and magnetic field dependence Mössbauer study of ɛ-Fe2O3

ɛ-Fe2O3 was synthesized as nanoparticles by a pre-vacuum heat treatment of yttrium iron garnet (Y3Fe5O12) in a silica matrix at 300-C followed by sintering in air at 1,000-C for up to 10 h. It displays complex magnetic properties that are characterized by two transitions, one at 480 K from a paramagnet (P) to canted antiferromagnet (CAF1) and the second at ca. 120 K from the canted antiferromagnet (CAF1) to another canted antiferromagnet (CAF2). CAF2 has a smaller resultant magnetic moment (i.e. smaller canting angle) than CAF1. Analysis of the zero-field Mossbauer spectra at different temperatures shows an associated discontinuity of the hyperfine field around 120 K. In an applied field, the different magnetic sublattices were identified and the directions of their moments were assigned. The moments of the two sublattices are antiparallel and collinear at 160 K but are at right angle to each other at 4.2 K

Parasitoses Génito-Urinaires

Les parasites ont rarement une localisation strictement rénale. Cependant, la bilharziose urinaire est très fréquente en Afrique sub-saharienne et se manifeste par une hématurie. L\'hydatidose est essentiellement localisée au niveau hépatique, mais des localisations rénales sont possibles. D\'autres parasitoses (filarioses, paludisme) provoquent des glomérulonéphrites par des réactions immunologiques, qui disparaissent avec le traitement spécifique du parasite responsable.Parasites in the urinary system only are rare. Schistosoma haematobium infection is very frequent in tropical Africa, and is revealed by hematuria. Hydatic cysts are mostly found in the liver, but a renal infection is possible. The other parasites (filariasis, malaria) often lead to immune complex glomerulonephritis and are cured by specific treatment of the parasites. Keywords: parasitoses urinaires, bilharziose urinaire, schistosoma haematobium, paludisme, hydatidose rénale, dioctophymeAfrican Journal of Urology Vol. 13 (3) 2007: pp. 206-21

NEUTRON DIFFRACTION STUDY OF THE STRUCTURE OF SOME ALUMINIUM- TRANSITION METAL NON PERIODIC CRYSTALS

A neutron scattering investigation of the structure of non periodic crystals Al-X, (X being Mn, Cr or MnCr mixture) has been performed. The negative coherent scattering length of Mn for thermal neutrons provided with a variable contrast with X. Our results are compared both with an X-Ray diffraction pattern and with a similar experiment performed on Al-(Mn,Fe) alloys using thermal neutron scattering. The hypothesis of the isomorphic substitution will be discussed and our results qualitatively checked with various structural models in order to try to determine the location of the atoms in the quasi-lattice

Neutron Diffraction Studies of the Binary Uranium Stannides USn2 and U3Sn7.

Abstract not availableJRC.E-Institute for Transuranium Elements (Karlsruhe

Growth Kinetics and Mechanisms of Aluminum Dots Promoted by Laser-Induced Decomposition of TMAA

International audienc

Hydrogenation of the ternary silicides RENiSi (RE = Ce, Nd) crystallizing in the tetragonal LaPtSi-type structure

International audienceHydrogenation of isostructural RENiSi (RE = Ce, Nd) intermetallic compounds has been performed..

Cationic Distribution in Defect Co-Mn Ferrites from Neutron Diffraction

Submicron stoichiometric cobalt manganese ferrites oxidized in air, at low temperature (<500°C) give defect spinel ferrites which exhibit a substantial increase in coercivity, reaching a maximum for ferrites oxidized near 350°C and slowly cooled (5°C/min) from the oxidation temperature. Two [MATH] samples oxidized at 350°C but exhibiting notably different coercivities because of different cooling rates (Hc=1750 Oe after quenching ; Hc=2350 Oe after slow cooling) have been analyzed by neutron diffraction at T=6K. They exhibit almost exactly the same structural and magnetic parameters, indicating that the difference between the coercivities has a purely local origin. Similar cationic distributions have been inferred. Neutron diffraction reveals a classical collinear ferrimagnetism on the A and B sublattices of the spinel structure

Efficacy of the anti-VZV (anti-HSV3) vaccine in HSV1 and HSV2 recurrent herpes simplex disease: a prospective study

Jacqueline Le Goaster,1 Sylvie Gonzalo,2 Patrice Bour&amp;eacute;e,1 Frederic Tangy,3 Anne-Lise Haenni41Department of Tropical Diseases, Centre Hospitalo-Universitaire (CHU), University of Paris XI, Le Kremlin Bic&amp;ecirc;tre, 2Biomnis Laboratory, Ivry-sur-Seine, 3Retro-Virology, Centre National de Recherche Scientifique (CNRS), Pasteur Institute, Paris; 4Jacques Monod Institute, Centre National de Recherche Scientifique (CNRS), University of Paris VII, Paris, FranceBackground: The aim of this study was to evaluate the possibility of using the anti-varicella zoster virus (anti-VZV, also known as anti-HSV3) vaccine against orobuccal herpes simplex virus type 1 (HSV1) and genital herpes simplex virus type 2 (HSV2). This was suggested by study of the phylogenetic tree of members of the herpes virus family, which showed a close relationship between VZV (HSV3) and the HSV1 and HSV2 herpes viruses.Methods: The present prospective study was conducted from January 2005 through January 2011. Twenty-four patients afflicted with HSV1 and HSV2 herpes recurrences over a period of years, numbering 6&amp;ndash;8 and more recurrences per year, agreed to receive the anti-VZV vaccine. They were compared with 26 nonvaccinated patients presenting with herpes simplex diseases 2&amp;ndash;5 times a year. All 50 patients were documented with anti-HSV1, anti-HSV2, and anti-VZV antibody serological testing.Results: From 2005 through 2011, for the 24 anti-VZV vaccinated patients, the average number of herpes relapses decreased to 0, correlated with an increased anti-VZV antibody level and clinical recovery of all patients, whereas no improvement was observed for the 26 nonvaccinated herpes patients.Conclusion: Data for the anti-VZV serological antibody levels tested before and after anti-VZV vaccination showed a significant (P &amp;lt; 0.001) increase among vaccinated patients. This suggests defective anti-VZV immune power in these patients. After 6 years of positive results for anti-VZV vaccine, this is a logical and fair hypothesis. We can now undertake a randomized study to confirm these findings.Keywords: HSV1/HSV2 herpes prevention, anti-VZV (HSV3) vaccine, anti-VZV vaccine therap

Magnetic structure and magnetic properties of synthetic lindgrenite, Cu-3(OH)(2)(MoO4)(2)

International audienceSynthetic Cu3(OH)2(MoO4)2 consists of Cu3(OH)2 brucite ribbons of edge-sharing copper octahedra connected by MoO4 into a 3D network as in the mineral, lindgrenite, for all temperatures between 1.5 and 300 K. Each ribbon consists of a triangular connection between two different types of copper atom (Cu(1) and 2 Cu(2)) via í3-OH. The MoO4 acts both as one- and three-atom bridges to connect six Cu atoms belonging to three adjacent ribbons. The magnetic properties are consistent with those of ferrimagnetic chains, and the resulting moment of each chain is parallel below the long-range magnetic ordering at 13 K. The Curie constant is 0.468(1) emu K mol-1 of Cu; the Weiss temperature is -14.2(2) K, and the saturation magnetization at 2 K in 50 kOe is 0.41 N íB mol-1 of Cu. Analyses of the neutron powder diffraction reveal an ordered magnetic state where the moment of Cu(1) is antiparallel to those of the two Cu(2); all of them point along the a axis without any sign of geometrical frustration. Any degeneracy that may be present because of the triangular topology of the Cu atoms (s ) 1/2) appears to be lifted by the distortion from an ideal equilateral geometry of the triangle. The entropy, estimated from the heat capacity measurements, attains 50% of the total of 17.7 J K-1 mol-1, close to that expected for three Cu atoms (3R ln 2), up to the long range ordering temperature, and the remaining is associated with the low dimensionality of the material