2,074 research outputs found

    Osteoartropatía hipertrófica pulmonar asociada a megaesófago en un perro

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    La osteoartropatía hipertrófica pulmonar (OHP) es una enfermedad de escasa presentación en la clínica rutinaria canina, secundaria a patologías intratorácicas crónicas, con lesiones que ocupan un cierto volumen intratorácico (neoplasias, abscesos, etc.), y que se caracteriza por la presencia de neoformaciones óseas en el periostio de los huesos de las extremidades. En el presente artículo se describe un caso clínico de osteoartropatía hipertrófica pulmonar (clínica, radiología, analítica sanguínea y urinaria, necropsia y estudios histopatológicos), asociada a un megaesófago, condición no descrita en la bibliografía consultada sobre la OHP canina.Hypertrophic pulmonary osteoarthropathy (HPO) is a rare clinical disease in the dog, secondary to spaceoccuping masses inside the thoracic cavity (neoplasms, abcesses, etc.) and it's characterized by neoformation of periosteal bone affecting mainly the distallimbs. The authors review the physiopathology of the disease and describe one clinical case of hypertrophic pulmonary osteoarthropathy (clinical state, radiology, blood and urine analysis, necropsy results and histologic conclusions) associated with megaesofagus, condition not yet described associated to HPO

    Non-classical light state transfer in su(2)su(2) resonator networks

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    We use a normal mode approach to show full and partial state transfer in a class of coupled resonator networks with underlying su(2)su(2) symmetry that includes the so-called JxJ_{x} photonic lattice. Our approach defines an auxiliary Hermitian coupling matrix describing the network that yields the normal modes of the system and its time evolution in terms of orthogonal polynomials. These results provide insight on the full quantum state reconstruction time in a general su(2)su(2) network of any size and the full quantum transfer time in the JxJ_{x} network of size 4n+14 n + 1 with n=1,2,3,n=1,2,3,\ldots In the latter, our approach shows that the Fock state probability distribution of the initial state is conserved but the amplitudes suffer a phase shift proportional to π/2\pi/2 that results in partial quantum state transfer for any other network size.Comment: 13 pages, 1 figur

    Beta-Cyclodextrin: Eugenol Inclusion Complexes: Characterization and Antifungal Capacity

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    Eugenol (EUG) is the principal component of clove essential oil. It has demonstrated excellent antifungal properties against B. cinerea, one of the most important fungus in the fresh fruit decay. However, this substance is highly volatile, thermolabile and the direct contact with a food induce undesirable changes in the organoleptic properties. For this reason, the application of EUG represents a big challenger and its encapsulation through inclusion complexes formation with β-cyclodextrin (β-CD) is presented as a solution. In this way, the aim of this work was to develop, characterize and assess the antifungal capacity of inclusion complexes β-CD:EUG. For this, co-precipitation was used as method of inclusion complexes synthesis. The quantity of entrapped EUG was determined by gaseous chromatography. The inclusion complexes were characterized by thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR). Moreover, the antifungal activity was probed in a headspace system. Results showed that the EUG entrapped quantity was of 68,5 mg/g inclusion complexes. Furthermore, the characteristic peaks of EUG did not appear in inclusion complexes TGA thermogram and FTIR spectrum which confirm the effective compound encapsulation. Finally, inclusion complexes inhibited the growing of A. cinerea at 53% and avoided the fungal sporulation. These findings suggest that the β- CD:EUG inclusion complexes are suitable to use in the storage and transportation of fresh fruits to prevent their deterioration. Keywords: Botrytis cinerea, fresh fruits, headspace. Resumen El eugenol (EUG) es el principal componente del aceite esencial de clavo de olor. Éste ha destacado por su efectivo control de Botrytis cinerea, uno de los hongos más importantes que provoca la pudrición de frutas frescas. Sin embargo, esta sustancia es altamente volátil, termolábil y provoca cambios desagradables en las propiedades organolépticas del alimento si está en contacto directo con el mismo, por lo que su aplicación presenta un gran desafío. Ante esto, se propone su encapsulación a través de la formación de complejos de inclusión con β-ciclodextrina (β-CD). En este sentido, el objetivo de la presente investigación fue desarrollar, caracterizar y evaluar la capacidad antifúngica de complejos de inclusión β-CD:EUG. Éstos se sintetizaron mediante el método de co-precipitación, y la cantidad de EUG atrapada en la β-CD fue cuantificada por cromatografía de gases. Los complejos de inclusión se caracterizaron a través de análisis termogravimétrico (TGA) y espectroscospía infrarroja con transformada de Fourier (FTIR). Además, su actividad antifúngica se evaluó en un sistema de espacio de cabeza. Los resultados mostraron que la cantidad de EUG atrapada fue de 68,5 mg/g de complejo de inclusión. Además, en su termograma TGA y espectro FTIR no se observaron los picos característicos del EUG, confirmando la efectiva encapsulación del compuesto. Finalmente, los complejos de inclusión inhibieron el 53% del crecimiento de B. cinerea y evitaron su esporulación. Estos resultados permiten sugerir el uso de complejos de inclusión β-CD:EUG en el almacenamiento y transporte de frutas frescas para prevenir su deterioro. Palabras clave: Botrytis cinerea, frutas frescas, espacio de cabeza

    Estadística Descriptiva y Probabilidad: (Teoría y problemas)

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    XXXIV, 261 p. ; 24 cm.Libro ElectrónicoÍndice Bibliografía: p. [256]-258 Manual para alumnos de titulaciones experimentales que proporciona una visión práctica e intuitiva de la estadística descriptiva y el cálculo de probabilidades, campos básicos y fundamentales de la ciencia estadísticaLibro : Español (spa) : 3a. edIndice general Prólogo XIII 1. Introducción XIII 2. History (Histórico) XV 3. Licencia de Documentación Libre de GNU XVI 4. GNU Free Documentation License XXVI A Estadística Descriptiva 1 1 Síntesis de la información 7 1. Rese˜na histórica 7 2. La organización de la información 9 3. Representaciones grá?cas 15 4. Medidas centrales 17 5. Medidas de posición 26 6. Medidas de dispersión 27 7. Desigualdad de Tchebychev 31 8. Momentos de la distribución 31 9. Medidas de forma 33 10. Transformaciones 36 11. Análisis exploratorio de datos 37 12. Ejercicios 40 2 Análisis conjunto de variables. 53 1. Distribución conjunta de dos caracteres 53 2. Distribuciones marginales 55 3. Distribuciones condicionadas 55 4. Independencia 60 5. Medidas de dependencia. Coeficientes de relación 61 6. Ejercicios 78 3 Ajuste y regresión bidimensional 89 1. Introducción 89 2. Ajuste. Criterio de los mínimos cuadrados 91 3. Análisis de la bondad del ajuste 97 4. Regresión. Método de regresión a la media 100 5. Análisis de la bondad de la regresión 102 6. Notas y conclusiones 104 7. Ejercicios 105 B Probabilidad 113 4 Teoría de la probabilidad 117 1. Evolución histórica 117 2. Conjuntos. Operaciones 120 3. Algebra de sucesos 122 4. Distintas de?niciones del concepto de probabilidad 126 5. Propiedades de la función de probabilidad 129 6. Probabilidad condicionada. Independencia 131 7. Dependencia e independencia 132 8. Teorema de la probabilidad total. Teorema de Bayes 133 9. Ejercicios 136 5 Variable aleatoria 145 1. Concepto 145 2. Variables discretas y continuas 146 3. Variables unidimensionales 147 4. Variables multidimensionales 161 5. Ejercicios 173 6 Algunos modelos probabilísticos 185 1. Distribución uniforme discreta 185 2. Experimento de Bernouilli 186 3. Distribución hipergeométrica 191 4. Proceso de Poisson 192 5. Distribución uniforme continua 195 6. Distribución normal 197 7. Relación entre binomial, Poisson y normal 200 8. Teorema central del límite 201 9. Distribución gamma 202 10. Distribución beta 203 11. Distribución de Cauchy 204 12. Distribuciones derivadas de la normal 206 13. Distribución de Laplace 210 14. Distribución logística 211 15. Distribución de Pareto 211 16. Algunos modelos multidimensionales 212 17. Ejercicios 215 A Combinatoria 225 1. Introducción 225 2. Variaciones con repetición 225 3. Variaciones 226 4. Permutaciones 226 5. Permutaciones con repetición 226 6. Combinaciones sin repetición 227 7. Combinaciones con repetición 228 8. Ejercicios 228 B Tablas Estadísticas 233 C Bibliografía 25

    Anomalous Raman Modes in Tellurides

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    Two broad bands are usually found in the Raman spectrum of many Te-based chalcogenides, which include binary compounds, like ZnTe, CdTe, HgTe, GaTe, GeTe, SnTe, PbTe, GeTe2, As2Te3, Sb2Te3, Bi2Te3, NiTe2, IrTe2, TiTe2, as well as ternary compounds, like GaGeTe, SnSb2Te4, SnBi2Te4, and GeSb2Te5. Many different explanations have been proposed in the literature for the origin of these two anomalous broad bands in tellurides, usually located between 119 and 145 cm-1. They have been attributed to the own sample, to oxidation, to the folding of Brillouin-edge modes onto the zone center, to the existence of a double resonance, like that of graphene, or to the formation of Te precipitates. In this paper, we provide arguments to demonstrate that such bands correspond to clusters or precipitates of trigonal Te in form of nanosize or microsize grains or layers that are segregated either inside or at the surface of the samples. Several mechanisms for Te segregation are discussed and sample heating caused by excessive laser power during Raman scattering measurements is emphasized. Finally, we show that anomalous Raman modes related to Se precipitates also occur in selenides, thus providing a general vision for a better characterization of selenides and tellurides by means of Raman scattering measurements and for a better understanding of chalcogenides in general.Comment: 45 pages, 8 figure

    Identification of the optical and near-infrared counterpart of GRS 1758-258

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    Context. Understood to be a microquasar in the Galactic center region, GRS 1758-258 has not yet been unambiguously identified to have an optical/near-infrared counterpart, mainly because of the high absorption and the historic lack of suitable astrometric stars, which led to the use of secondary astrometric solutions. Although it is considered with 1E 1740.7-2942 as the prototypical microquasar in the Galactic center region, the Galactic origin of both sources has not yet been confirmed. Aims. We attempt to improve previous astrometry to identify a candidate counterpart to GRS 1758-258. We present observations with the Gran Telescopio de Canarias (GTC), in which we try to detect any powerful emission lines that would infer an extragalactic origin of this source. Methods. We use modern star catalogues to reanalyze archival images of the GRS 1758-258 field in the optical and near-infrared wavelengths, and compute a new astrometric solution. We also reanalyzed archival radio data of GRS 1758-258 to determine a new and more accurate radio position. Results. Our improved astrometric solution for the GRS 1758-258 field represents a significant advancement on previous works and allows us to identify a single optical/near-infrared source, which we propose as the counterpart of GRS 1758-258. The GTC spectrum of this source is however of low signal-to-noise ratio and does not rule out a Galactic origin. Hence, new spectral observations are required to confirm or discard a Galactic nature.Comment: 4 pages, 3 figures, accepted by Astronomy and Astrophysic

    Structural stability of Fe5Si3 and Ni2Si studied by high-pressure x-ray diffraction and ab initio total-energy calculations

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    We performed high-pressure angle dispersive x-ray diffraction measurements on Fe5Si3 and Ni2Si up to 75 GPa. Both materials were synthesized in bulk quantities via a solid-state reaction. In the pressure range covered by the experiments, no evidence of the occurrence of phase transitions was observed. On top of that, Fe5Si3 was found to compress isotropically, whereas an anisotropic compression was observed in Ni2Si. The linear incompressibility of Ni2Si along the c-axis is similar in magnitude to the linear incompressibility of diamond. This fact is related to the higher valence-electron charge density of Ni2Si along the c-axis. The observed anisotropic compression of Ni2Si is also related to the layered structure of Ni2Si where hexagonal layers of Ni2+ cations alternate with graphite-like layers formed by (NiSi)2- entities. The experimental results are supported by ab initio total-energy calculations carried out using density functional theory and the pseudopotential method. For Fe5Si3, the calculations also predicted a phase transition at 283 GPa from the hexagonal P63/mcm phase to the cubic structure adopted by Fe and Si in the garnet Fe5Si3O12. The room-temperature equations of state for Fe5Si3 and Ni2Si are also reported and a possible correlation between the bulk modulus of iron silicides and the coordination number of their minority element is discussed. Finally, we report novel descriptions of these structures, in particular of the predicted high-pressure phase of Fe5Si3 (the cation subarray in the garnet Fe5Si3O12), which can be derived from spinel Fe2SiO4 (Fe6Si3O12).Comment: 44 pages, 13 figures, 3 Table
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