Role of Syk-coupled C-type lectin receptors in T cell immunity to fungal stimuli

Innate signals are fundamental to determine the class of adaptive response against infection. The translation of microbial signatures into adaptive immunity is mediated by pattern recognition receptors (PRRs), which are expressed in specialized leukocytes called dendritic cells (DCs) and results in responses matched to the nature of the offending microbe. Here, I provide evidence that two Syk-coupled C-type lectin receptors (CLRs), Dectin-1 and Dectin-2, act in the coordination of adaptive immune responses to fungal stimuli and fungal pathogens. DC activated via Dectin-1 are strong elicitors of IL-17 production by CD4+ T cells. Results presented in this thesis demonstrate that Dectin-1 signalling in DCs results in the generation and Foxp3+-IL-17+ T cells, a cell type that defies either regulatory or Th17 classification. This process is dependent on IL-23, which is produced by DCs upon Dectin-1 ligation. In addition, this work identified an additional CLR responsible for the induction of Th17 responses during the course of fungal infections. This thesis demonstrates that Dectin-2 is a second Syk-coupled PRR involved in DC activation by fungi. In a model of Candida albicans systemic infection, Dectin-2 is essential for the induction of Th17 responses to the organism. Finally, I have generated tools to study responses of T cells specific for a fungal-associated antigen. Furthermore, I provide preliminary evidence regarding the activation, proliferation and trafficking of antigen-specific CD4+ and CD8+ T cells during systemic fungal infections

LA DESPENALIZACIÓN DEL ABORTO POR VIOLACIÓN SEXUAL EN EL PERÚ

En esta primera parte del Trabajo de investigación sobre la despenalización del aborto por violación sexual en el Perú se intenta separar doctrina jurídica de las posturas religiosas y/o morales, por lo cual, es natural que dichos puntos de vista no concilien necesariamente entre sí. Por lo cual haciendo uso de la escuela del Derecho Libre y la Teoría del Liberalismo, no podemos continuar aceptando la tradición al corriente ¨Involucionista¨ el cual aún sigue vigente en nuestra sociedad.La Despenalización del Aborto por violación sexual es un derecho que les corresponde a las mujeres a decidir sobre la interrupción de su embarazo. El mismo que no las obliga sólo les otorga la Facultad de ejercer la o no. En este sentido es preciso considerar que el término VIDA presenta dos niveles a) ¨Nacer con vida¨ o ¨Estar vivo¨: la condición de ser humano vivo, y b) ¨Vivir¨: y disfrutar plenamente de la misma. En conclusión la despenalización del aborto por violación sexual permitirá que muchas mujeres tengan la Facultad de decidir de continuar con el embarazo o no, asimismo evitar el nivel de mortalidad y las que sufren a causa de abortos mal practicados al contar con servicios seguros y accesibles entre otros aspectos

Ta2O5/SiO2 insulating acoustic mirrors for AlN-based X-band BAW resonators

This work describes the performance of AlN-based bulk acoustic wave resonators built on top of insulating acoustic reflectors and operating at around 8 GHz. The acoustic reflectors are composed of alternate layers of amorphous Ta2O5and SiO2 deposited at room temperature by pulsed-DC reactive sputtering in Ar/O2 atmospheres. SiO2 layers have a porous structure that provides a low acoustic impedance of only 9.5 MRayl. Ta2O5 films exhibit an acoustic impedance of around 39.5 MRayl that was assessed by the picoseconds acoustic technique These values allow to design acoustic mirrors with transmission coefficients in the centre of the band lower than -40 dB (99.998 % of reflectance) with only seven layers. The resonators were fabricated by depositing a very thin AlN film onto an iridium bottom electrode 180 nm-thick and by using Ir or Mo layers as top electrode. Resonators with effective electromechanical coupling factors of 5.7% and quality factors at the antiresonant frequency around 600 are achieved

Low-thickness high-quality aluminum nitride films for super high frequency solidly mounted resonators

We investigate the sputter growth of very thin aluminum nitride (AlN) films on iridium electrodes for electroacoustic devices operating in the super high frequency range. Superior crystal quality and low stress films with thicknesses as low as 160 nm are achieved after a radio frequency plasma treatment of the iridium electrode followed by a two-step alternating current reactive magnetron sputtering of an aluminum target, which promotes better conditions for the nucleation of well textured AlN films in the very first stages of growth. Solidly mounted resonators tuned around 8 GHz with effective electromechanical coupling factors of 5.8% and quality factors Q up to 900 are achieved

Piezoelectric and electroacoustic properties of Ti-doped AlN thin films as a function of Ti content

In this work we present the assessment of the structural and piezoelectric properties of Al(0.5-x)TixN0.5 compounds (titanium content menor que6% atomic), which are expected to possess improved properties than conventional AlN films, such as larger piezoelectric activity, thermal stability of frequency and temperature resistance. Al:Ti:N films were deposited from a twin concentric target of Al and Ti by reactive AC sputtering, which provided films with a radial gradient of the Ti concentration. The properties of the films were investigated as a function of their composition, which was measured by electron dispersive energy dispersive X-ray spectroscopy and Rutherford backscattering spectrometry. The microstructure and morphology of the films were assessed by X-ray diffraction and infrared reflectance. Their electroacoustic properties and dielectric constant were derived from the frequency response of BAW test resonators. Al:Ti:N films properties appear to be strongly dependent on the Ti content, which modifies the AlN wurtzite crystal structure leading to greater dielectric constant, lower sound velocities, lower electromechanical factor and moderately improved temperature coefficient of the resonant frequency

Growth of AlN oriented films on insulating substrates.

This work describes the structural and piezoelectric assessment of aluminum nitride (AlN) thin films deposited by pulsed-DC reactive sputtering on insulating substrates. We investigate the effect of different insulating seed layers on AlN properties (crystallinity, residual stress and piezoelectric activity). The seed layers investigated, silicon nitride (Si3N4), silicon dioxide (SiO2), amorphous tantalum oxide (Ta2O5), and amorphous or nano-crystalline titanium oxide (TiO2) are deposited on glass plates to a thickness lower than 100 nm. Before AlN films deposition, their surface is pre-treated with a soft ionic cleaning, either with argon or nitrogen ions. Only AlN films grown of TiO2 seed layers exhibit a significant piezoelectric activity to be used in acoustic device applications. Pure c-axis oriented films, with FWHM of rocking curve of 6º, stress below 500 MPa, and electromechanical coupling factors measured in SAW devices of 1.25% are obtained. The best AlN films are achieved on amorphous TiO2 seed layers deposited at high target power and low sputtering pressure. On the other hand, AlN films deposited on Si3N4, SiO2 and TaOx exhibit a mixed orientation, high stress and very low piezoelectric activity, which invalidate their use in acoustic devices

Influence of Crystal Quality on the Excitation and Propagation of Surface and Bulk Acoustic Waves in Polycrystalline AlN Films

We investigate the excitation and propagation of acoustic waves in polycrystalline aluminum nitride films along the directions parallel and normal to the c-axis. Longitudinal and transverse propagations are assessed through the frequency response of surface acoustic wave and bulk acoustic wave devices fabricated on films of different crystal qualities. The crystalline properties significantly affect the electromechanical coupling factors and acoustic properties of the piezoelectric layers. The presence of misoriented grains produces an overall decrease of the piezoelectric activity, degrading more severely the excitation and propagation of waves traveling transversally to the c-axis. It is suggested that the presence of such crystalline defects in c-axis-oriented films reduces the mechanical coherence between grains and hinders the transverse deformation of the film when the electric field is applied parallel to the surface

Dinamización del sistema de contrataciones públicas en Nicaragua con la implementación de la modalidad de acuerdo marco

Las contrataciones administrativas son de gran importancia en el desarrollo del país, en tanto que son un medio para garantizar las adquisiciones de las diferentes instituciones y entidades administrativas con el propósito de alcanzar el interés colectivo, la transparencia del gasto público y el control presupuestario. La aprobación de la Ley 737 y su reglamento en el año 2010 referida a las contrataciones Administrativas del Sector Público ha implicado la puesta en marcha de novedosos procedimientos de compras, así como la implementación y utilización del sistema electrónico para las notificaciones estableciendo con ello una nueva relación jurídica contractual de carácter virtual que permite ahorros presupuestarios, mayor agilidad e incluso un alto grado de transparencia y publicidad. Entre los novedosos procedimientos de compra que establece la ley, encontramos el Acuerdo Marco a implementarse en Nicaragua, el cual constituye un proceso administrativo de compra ejecutado y administrado por el Órgano Rector del Sistema Nacional de Compras Públicas, que busca satisfacer la demanda (adquisición) de bienes y servicios de parte de las instituciones de la Administración Pública (Estado), que tiene como herramientas necesarias para su funcionamiento, los estudios económicos de factibilidad que van desde la necesidad del producto, la calidad, el presupuesto, los descuentos, las garantías, promociones, la cobertura, entre otros, hasta el aprovechamiento de las nuevas tecnologías informáticas como medios para la transabilidad y transaccionalidad. Se Busca fortalecer principios básicos de la buena gestión pública como la transparencia, eficacia y eficiencia, así como también, la modernización de las Instituciones del Estado cuyas buenas prácticas, ya se han implementado en otros países, tanto de Europa como de Latino américa, que han dado grandes resultados y beneficios como lo son el ahorro monetario, administrativo y logístico en la reducción de costos por parte del Estado en la adquisición de bienes y servicios. Precisamente por considerar de vital importancia para el desarrollo de nuestro país hemos decidido efectuar el presente trabajo de culminación de nuestros estudios universitarios y que hemos llamado ¨Sistema de Contrataciones del Sector Público en Nicaragua ¨ siendo el Subtema: Dinamización del Sistemas de Contrataciones Públicas en Nicaragua con la con la implementación de la Modalidad de Acuerdo Marco. El trabajo lo desarrollamos en siete capítulos, a saber: En el Capítulo I nos referimos a las Generalidades del Derecho Administrativo, su definición, principios y característica. El Capítulo II abordamos el Contrato Administrativo y sus características. El Capítulo III refiere al Sistema de Contrataciones Administrativas del Sector Público en América Latina y Nicaragua, en el cual desarrollamos los aspectos más importantes de la Administración Pública, desatacando la estructura orgánica de éste y las características esenciales de la centralización y descentralización administrativa así como los órganos que componen cada uno de ellos. El Capítulo IV abordamos la dinamización de los procesos de contratación mediante la modalidad de Acuerdo Marco. Su definición y ventajas En el Capítulo V señalamos el procedimiento para contratar a través de Acuerdo Marco Capítulo VI Derecho comparado en relación al acuerdo marco, particularmente tratamos Chile, Panamá y Costa Rica entre otros. Capitulo VII, será el Análisis de la Importancia de la Modalidad de Acuerdo Marco

Characterization of Amorphous Tantalum Oxide for Insulating Acoustic Mirrors

This work describes the assessment of the acoustic properties of sputtered tantalum oxide films intended as high impedance films for the acoustic isolation of bulk acoustic wave devices operating in the GHz frequency range. The films are grown by sputtering a metallic tantalum target under different oxygen and argon gas mixtures, total pressures, pulsed DC powers and substrate bias. The structural properties of the films are assessed through infrared absorption spectroscopy and X-ray diffraction measurements. Their acoustic impedance is obtained after estimating the mass density by X-ray reflectometry measurements and the longitudinal acoustic velocity by analyzing the longitudinal λ/2 resonance induced in a tantalum oxide film inserted between an acoustic reflector and an AlN-based resonator. A second measurement of the sound velocity is achieved through picosecond acoustic spectroscopy

High-Acoustic-Impedance Tantalum Oxide Layers for Insulating Acoustic Reflectors

This work describes the assessment of the acoustic properties of sputtered tantalum oxide films intended for use as high-impedance films of acoustic reflectors for solidly mounted resonators operating in the gigahertz frequency range. The films are grown by sputtering a metallic tantalum target under different oxygen and argon gas mixtures, total pressures, pulsed dc powers, and substrate biases. The structural properties of the films are assessed through infrared absorption spectroscopy and X-ray diffraction measurements. Their acoustic impedance is assessed by deriving the mass density from X-ray reflectometry measurements and the acoustic velocity from picosecond acoustic spectroscopy and the analysis of the frequency response of the test resonators