Diagnostic value of computed tomography, radiography and ultrasonography in metacarpophalangeal joint disorders in horses

In modern society the work and athletic performance of horses has led to a very important animal production sector in which Brazil possesses the third largest horse stock. Among all equine lesions described, metacarpophalangeal (fetlock) joint lesions are considered one of the main causes of lameness. Consequently, there is a need to improve the understanding and diagnosis of these injuries. The most efficient imaging diagnostic methods for the fetlock region are computed tomography, radiography and ultrasound. Imaging studies of the anatomical structures involving this joint are extremely important to obtain a more precise diagnose. The present study was performed in order to evaluate the capacity of different imaging diagnostic modalities to detect a variety of lesions in different fetlock structures. Twenty horses (Equus caballus) used for horsemanship activities were referred to the Department of Animal Reproduction and Veterinary Radiology of São Paulo State University, Botucatu campus, with clinical signs of metacarpophalangeal joint injuries. Horses were submitted to radiographic and ultrasonographic exam and computed tomography scan. Image analysis revealed a significant capacity of these methods to characterize lesions in this region. However, computed tomography provided broader and better evaluation of lesions in bones and adjacent structures, because it allows the analysis to be performed on three-dimensional projections, with attenuation coefficients (window selections) and tissue density measurement through Hounsfield Units (HU)

Structural and magnetic properties of pyrochlores Gd2−xMxRu2O7 (M=Ho, Y)

AbstractIn this paper we investigated the structural and magnetic properties of the Gd2−xMxRu2O7 (M=Ho and Y, x=0.0, 0.1, 0.2, 1.0 and 2.0) pyrochlores. The samples were prepared by solid state reaction method, characterized structurally by X-ray diffraction with Rietveld refinement and magnetically by measuring the temperature dependence of the magnetization. X-ray diffractograms of all samples studied presented a cubic pyrochlore type crystal structure with lattice parameters varying linearly in accordance with Vegards law. It is shown that by substituting Gd by Ho one can tune the magnetic order of this system moving from antiferromagnetic (in the absence of Ho) to ferromagnetic (in the absence of Gd). On the other hand by replacing Gd for Y the antiferromagnetic order is decreased.© 2010 Elsevier Science. All rights reserve

Preparation and crystallization of hollow α-Fe2O3 microspheres following the gas-bubble template method

This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.matchemphys.2015.11.021In this work we report the formation of hollow ?-Fe2O3 (hematite) microspheres by the gas-bubble template method. This technique is simple and it does not require hard templates, surfactants, special conditions of atmosphere or complex steps. After reacting Fe(NO3)3.9H2O and citric acid in water by sol-gel, the precursor was annealed in air at different temperatures between 180 and 600 ?C. Annealing at 550 and 600 ?C generates bubbles on the melt which crystallize and oxidizes to form hematite hollow spheres after condensation. The morphology and crystal evolution are studied by means of X-ray diffraction and scanning electron microscopy. We found that after annealing at 250-400 ?C, the sample consist of a mixture of magnetite, maghemite and hematite. Single hematite phase in the form of hollow microspheres is obtained after annealing at 500 and 600 ?C. The crystallization and crystal size of the hematite shells increase with annealing temperature. A possible mechanism for hollow sphere formation is presented.This work was supported by the Engineering and Physical Science Research Council (EPSRC No. EP/J003638/1). The work in Peru has been supported by CONCYTEC. The work in Brazil was supported by CNPq (307552/2012-8), CAPES (PNPD- 230.007518/2011-11) and FACEPE (APQ-0589-1.05/08)