59 research outputs found

    The Major Histocompatibility Complex in Transplantation

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    The transplant of organs is one of the greatest therapeutic achievements of the twentieth century. In organ transplantation, the adaptive immunity is considered the main response exerted to the transplanted tissue, since the principal target of the immune response is the MHC (major histocompatibility complex) molecules expressed on the surface of donor cells. However, we should not forget that the innate and adaptive immunities are closely interrelated and should be viewed as complementary and cooperating. When a human transplant is performed, HLA (human leukocyte antigens) molecules from a donor are recognized by the recipient's immune system triggering an alloimmune response Matching of donor and recipient for MHC antigens has been shown to have a significant positive effect on graft acceptance. This paper will present MHC, the innate and adaptive immunities, and clinical HLA testing

    Recent Research in Ocular Cystinosis: Drug Delivery Systems, Cysteamine Detection Methods and Future Perspectives

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    Cystinosis is a rare genetic disorder characterized by the accumulation of cystine crystals in different tissues and organs. Although renal damage prevails during initial stages, the deposition of cystine crystals in the cornea causes severe ocular manifestations. At present, cysteamine is the only topical effective treatment for ocular cystinosis. The lack of investment by the pharmaceutical industry, together with the limited stability of cysteamine, make it available only as two marketed presentations (Cystaran® and Cystadrops®) and as compounding formulations prepared in pharmacy departments. Even so, new drug delivery systems (DDSs) need to be developed, allowing more comfortable dosage schedules that favor patient adherence. In the last decades, different research groups have focused on the development of hydrogels, nanowafers and contact lenses, allowing a sustained cysteamine release. In parallel, different determination methods and strategies to increase the stability of the formulations have also been developed. This comprehensive review aims to compile all the challenges and advances related to new cysteamine DDSs, analytical determination methods, and possible future therapeutic alternatives for treating cystinosisThis research was funded by Fundación Española de Farmacia Hospitalaria (FEFH 18-19), Fundación Mutua Madrileña (XVI Convocatoria de Ayudas a la Investigación en Salud) and “Asociación La Lucha de Iker”. C.M.-G. and A.F.-F. have funding research grants from Instituto de Salud Carlos III (C.M.-G.-Río Hortega CM18/00090 and A.F.-F.-Juan Rodés JR18/0004)S

    Laboratorio virtual basado en MATLAB para la docencia de Acústica en el Grado de Telecomunicación

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    En este trabajo se presentan los primeros resultados derivados del desarrollo de un laboratorio virtual para el estudio de las ondas mecánicas en barras con diferentes condiciones de contorno. La aplicación permite visualizar tanto las ondas dentro del sólido como las ondas sonoras producidas por la barra sometida a un impacto. Esta aplicación pretende ser la base de un laboratorio virtual completo que cubra diferentes situaciones didácticas dentro del campo de la Acústica. La interfaz gráfica se ha realizado en MATLAB para que el alumno pueda configurar la experiencia sin tener conocimientos avanzados de programación. La herramienta permite variar de forma sencilla los parámetros físicos de las barras a simular, así como el tipo de fijación en la barra y el punto de excitación. La aplicación representa en tiempo real la distribución de velocidades en el interior de la barra y en aire que la rodea, permitiendo al estudiante identificar de forma visual los diferentes fenómenos que se producen en estos sistemas: ondas longitudinales, ondas transversales y ondas superficiales Love y/o Rayleigh. Se pretende distribuir la herramienta de forma libre a los estudiantes en el siguiente curso académico para evaluar el impacto que este tipo de estrategias tienen en el proceso de enseñanza-aprendizaje.Los autores desean agradecer la financiación de la Universidad de Alicante vía los proyectos GITE-09006-UA, GITE-09014-UA, y al ICE de la Universidad de Alicante a través de la convocatoria de Proyectos de Redes 2013-2014 y su soporte a la red 3092

    Combined fit to the spectrum and composition data measured by the Pierre Auger Observatory including magnetic horizon effects

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    The measurements by the Pierre Auger Observatory of the energy spectrum and mass composition of cosmic rays can be interpreted assuming the presence of two extragalactic source populations, one dominating the flux at energies above a few EeV and the other below. To fit the data ignoring magnetic field effects, the high-energy population needs to accelerate a mixture of nuclei with very hard spectra, at odds with the approximate E2^{-2} shape expected from diffusive shock acceleration. The presence of turbulent extragalactic magnetic fields in the region between the closest sources and the Earth can significantly modify the observed CR spectrum with respect to that emitted by the sources, reducing the flux of low-rigidity particles that reach the Earth. We here take into account this magnetic horizon effect in the combined fit of the spectrum and shower depth distributions, exploring the possibility that a spectrum for the high-energy population sources with a shape closer to E2^{-2} be able to explain the observations

    Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory

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    In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data

    Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory

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    The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle
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