Treinta años del control del doping en los hipódromos españoles: 1983-2014

El deseo de lograr la victoria con el menor esfuerzo o la garantía de la derrota segura del rival, es un sentimiento tan antiguo como la historia del deporte, para conseguirlo a lo largo del tiempo los métodos, las formas, las sustancias para alterar el rendimiento físico han evolucionado, aunque la intención se mantiene de forma invariable. En nuestros días el doping está presente en la mayoría de los deportes y las carreras de caballos no son una excepción. Por esta razón con el fin de salvaguardar el bienestar animal, la limpieza del deporte y la protección del juego en los hipódromos españoles se realiza “el control del doping”, se practica a los caballos PSI de carreras, hasta ahora, siguiendo las directrices del “Código de la Sociedad Fomento de la Cría Caballar en España” (SFCCE), de esta forma tratamos de impedir el uso fraudulento de sustancias dopantes o el abuso de las sustancias medicamentosas. El control del doping en los hipódromos españoles empezó en 1960, gracias a un acuerdo entre la SFCCE y la Cátedra de Farmacología y Toxicología de la Facultad de Veterinaria de la Universidad Complutense, de lo sucedido en estos primeros años incluimos en nuestro trabajo un estudio crítico. En 1983 la SFCCE se modernizó y delegó la responsabilidad de los análisis de orina y sangre a un laboratorio homologado por la International Federation of Horseracing Authorities (IFHA). Por esta razón, en nuestro trabajo aportamos los datos correspondientes al control del doping de los caballos de carreras en España desde 1983 y hasta diciembre de 2014...

Subband energy in two-band δ-doped semiconductors

We study electron dynamics in a two-band δ-doped semiconductor within the envelope-function approximation. Using a simple parametrization of the confining potential arising from the ionized donors in the δ -doping layer, we are able to find exact solutions of the Dirac-type equation describing the coupling of host bands. As an application we then consider Si δ -doped GaAs. In particular we find that the ground subband energy scales as a power law of the Si concentration per unit area in a wide range of doping levels. In addition, the coupling of host bands leads to a depression of the subband energy due to nonparabolicity effects.

Phase diagram and influence of defects in the double perovskites

The phase diagram of the double perovskites of the type Sr_(2-x)La_(x)FeMoO_(6) is analyzed, with and without disorder due to antisites. In addition to an homogeneous half metallic ferrimagnetic phase in the absence of doping and disorder, we find antiferromagnetic phases at large dopings, and other ferrimagnetic phases with lower saturation magnetization, in the presence of disorder.

The role of impurities in the shape, structure and physical properties of semiconducting oxide nanostructures grown by thermal evaporation

A thermal evaporation method developed in the research group enables to grow and design several morphologies of semiconducting oxide nanostructures, such as Ga_2O_3, GeO_2 or Sb_2O_3, among others, and some ternary oxide compounds (ZnGa_2O_4, Zn_2GeO_4). In order to tailor physical properties, a successful doping of these nanostructures is required. However, for nanostructured materials, doping may affect not only their physical properties, but also their morphology during the thermal growth process. In this paper, we will show some examples of how the addition of impurities may result into the formation of complex structures, or changes in the structural phase of the material. In particular, we will consider the addition of Sn and Cr impurities into the precursors used to grow Ga_2O_3, Zn_2GeO_4 and Sb_2O_3 nanowires, nanorods or complex nanostructures, such as crossing wires or hierarchical structures. Structural and optical properties were assessed by electron microscopy (SEM and TEM), confocal microscopy, spatially resolved cathodoluminescence (CL), photoluminescence, and Raman spectroscopies. The growth mechanisms, the luminescence bands and the optical confinement in the obtained oxide nanostructures will be discussed. In particular, some of these nanostructures have been found to be of interest as optical microcavities. These nanomaterials may have applications in optical sensing and energy devices.

Tubular micro- and nanostructures of TCO materials grown by a vapor-solid method

Microtubes and rods with nanopipes of transparent conductive oxides (TCO), such as SnO_2, TiO_2, ZnO and In_2O_3, have been fabricated following a vapor-solid method which avoids the use of catalyst or templates. The morphology of the as-grown tubular structures varies as a function of the precursor powder and the parameters employed during the thermal treatments carried out under a controlled argon flow. These materials have been also doped with different elements of technological interest (Cr, Er, Li, Zn, Sn). Energy Dispersive X-ray Spectroscopy (EDS) measurements show that the concentration of the dopants achieved by the vapor-solid method ranges from 0.5 to _3 at.%. Luminescence of the tubes has been analyzed, with special attention paid to the influence of the dopants on their optical properties. In this work, we summarize and discuss some of the processes involved not only in the anisotropic growth of these hollow micro and nanostructures, but also in their doping.