Estudio de estrategias de inmovilización de biomoléculas sobre soportes rígidos para aplicación en microbiosensores

El desarrollo de nuevos materiales para la mejora de sistemas analíticos basados en receptores moleculares -principalmente proteínas y ácidos nucleicos- altamente sensibles, con gran capacidad de trabajo y de manejo sencillo, tiene un gran potencial frente a los principales retos planteados hoy en día, como asistencia en tiempo real, detección multianalito, selectividad elevada y portabilidad, entre otros. Los sistemas analíticos desarrollados en la presente tesis se caracterizan por trabajar a escala micro y nanométrica, requerir la inmovilización controlada del elemento de reconocimiento biológico (biorreceptor o sonda) en la superficie, e incorporar un cierto grado de automatización, siendo el objetivo último y fundamental la aplicación de los desarrollos más prometedores a problemáticas concretas. En consecuencia, durante la realización del trabajo de tesis, se han planteado metodologías para la modificación química de diferentes materiales (silicio y derivados, óxido de tántalo y polímeros orgánicos) y la inmovilización de sondas de biorreceptores para el desarrollo de sistemas de detección óptica de dianas, en formato con y sin marcaje. En este sentido, una parte de la tesis aborda la puesta a punto de sistemas de ensayo a escala micrométrica utilizando como plataformas analíticas discos compactos. En este caso, se trata de modificar convenientemente los polímeros que componen ambas caras de los CDs (policarbonato y polimetilmetacrilato) para imprimir micromatrices de reactivos de captura. La lectura de resultados se efectúa a partir de las señales generadas por los trazadores, utilizando un lector de CDs de audio-video estándar. Esta metodología, se ha aplicado a la detección de gripe aviaria en muestras de saliva, así como a la detección de polimorfismos de una sola base (SNPs) para sondas de ADN. En otra aproximación se ha trabajado con materiales derivados de silicio y óxido de tántalo. Sus propiedades dieléctricas y su rigidez los hacen ideales para el dGonzález Pedro, MV. (2012). Estudio de estrategias de inmovilización de biomoléculas sobre soportes rígidos para aplicación en microbiosensores [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/16874Palanci

FPGA Implementation of an Adaptive Noise Canceller for Robust Speech Enhancement Interfaces

This paper describes the design and implementation results of an adaptive Noise Canceller useful for the construction of Robust Speech Enhancement Interfaces. The algorithm being used has very good performance for real time applications. Its main disadvantage is the requirement of calculating several operations of division, having a high computational cost. Besides that, the accuracy of the algorithm is critical in fixed-point representation due to the wide range of the upper and lower bounds of the variables implied in the algorithm. To solve this problem, the accuracy is studied and according to the results obtained a specific word-length has been adopted for each variable. The algorithm has been implemented for Altera and Xilinx FPGAs using high level synthesis tools. The results for a fixed format of 40 bits for all the variables and for a specific word-length for each variable are analyzed and discussed

Responsabilidad social empresaria en la hoteleria mendocina

La Responsabilidad Social Empresaria (RSE) es una forma de desarrollar negocios de forma comprometida con temas ambientales, sociales y culturales. Es una práctica voluntaria que ha tenido gran aceptación en todo el mundo y de a poco en la Artentina va adquiriendo mayor relevancia. En Mendoza cada vez hay más empresas interesadas en prácticas socialmente responsables, pero todavía queda mucho para hacer. En el presente trabajo se abordará la problemática de la RSE en la hotelería mendocina, un área donde todavía no se expanden ampliamente los conceptos de responsabilidad social.Fil: Pedro, Paul Maximiliano de. Universidad Nacional de Cuyo. Facultad de Ciencias Económicas.Fil: Di Fabio, Melisa Andrea. Universidad Nacional de Cuyo. Facultad de Ciencias Económicas.Fil: González Mendoza, María Victoria. Universidad Nacional de Cuyo. Facultad de Ciencias Económicas

Modeling High-Efficiency Quantum Dot Sensitized Solar Cells

[EN] With energy conversion efficiencies in continuous growth, quantum dot sensitized solar cells (QDSCs) are currently under an increasing interest, but there is an absence of a complete model for these devices. Here, we compile the latest developments in this kind of cells in order to attain high efficiency QDSCs, modeling the performance. CdSe QDs have been grown directly on a TiO(2) surface by successive ionic layer adsorption and reaction to ensure high QD loading. ZnS coating and previous growth of OS were analyzed. Polysulfide electrolyte and Cu(2)S counterelectrodes were used to provide higher photocurrents and fill factors, FF. Incident photon-to-current efficiency peaks as high as 82%, under full 1 sun illumination, were obtained, which practically overcomes the photocurrent limitation commonly observed in QDSCs. High power conversion efficiency of up to 3.84% under full 1 sun illumination (V(oc) = 0.538 V, j(sc) = 13.9 mA/cm(2), FF = 0.51) and the characterization and modeling carried out indicate that recombination has to be overcome for further improvement of QDSC.This work was supported by the Ministerio de Ciencia e Innovacion of Spain under the projects HOPE C5D2007-00007, JES-NANOSOLAR PLE2009-0042, and MAT2007-62982, and by Generalitat Valenciana under the project PROME-TEO/2009/058. The authors want to acknowledge S. Gimenez for the TEM measurements and the calculation of expected currents from IPCE, A. Braga for the preparation of CdS sensitized substrates, and also the SCIC of University Jaume I (Spain) for providing the microscopy facilities.González Pedro, MV.; Xu, X.; Mora-Sero, I.; Bisquert Mascarell, JA. (2010). Modeling High-Efficiency Quantum Dot Sensitized Solar Cells. ACS Nano. 4(10):5783-5790. https://doi.org/10.1021/nn101534yS5783579041

The 2010 very high energy gamma-ray flare and 10 years of multi-wavelength observations of M 87

The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3-6) x 10(9) M-circle dot) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) gamma-ray emission generated in relativistic outflows and the surroundings of supermassive black holes. M 87 has been established as a VHE gamma-ray emitter since 2006. The VHE gamma-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in 2010 are reported. During the campaign, a flare at VHE was detected triggering further observations at VHE (H.E.S.S.), X-rays (Chandra), and radio (43 GHz Very Long Baseline Array, VLBA). The excellent sampling of the VHE gamma-ray light curve enables one to derive a precise temporal characterization of the flare: the single, isolated flare is well described by a two-sided exponential function with significantly different flux rise and decay times of tau(rise)(d) = (1.69 +/- 0.30) days and tau(decay)(d) = (0.611 +/- 0.080) days, respectively. While the overall variability pattern of the 2010 flare appears somewhat different from that of previous VHE flares in 2005 and 2008, they share very similar timescales (similar to day), peak fluxes (Phi(>0.35 TeV) similar or equal to (1-3) x 10(-11) photons cm(-2) s(-1)), and VHE spectra. VLBA radio observations of 43 GHz of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken similar to 3 days after the peak of the VHE gamma-ray emission reveal an enhanced flux from the core (flux increased by factor similar to 2; variability timescale <2 days). The long-term (2001-2010) multi-wavelength (MWL) light curve of M 87, spanning from radio to VHE and including data from Hubble Space Telescope, Liverpool Telescope, Very Large Array, and European VLBI Network, is used to further investigate the origin of the VHE gamma-ray emission. No unique, common MWL signature of the three VHE flares has been identified. In the outer kiloparsec jet region, in particular in HST-1, no enhanced MWL activity was detected in 2008 and 2010, disfavoring it as the origin of the VHE flares during these years. Shortly after two of the three flares (2008 and 2010), the X-ray core was observed to be at a higher flux level than its characteristic range (determined from more than 60 monitoring observations: 2002-2009). In 2005, the strong flux dominance of HST-1 could have suppressed the detection of such a feature. Published models for VHE gamma-ray emission from M 87 are reviewed in the light of the new data

Moderate intake of red wine promotes a significant increase of phenolic metabolites in human faeces

With the final aim of ascertaining consistent data about the changes of phenolic metabolites in faeces after a regular wine consumption, the present paper compiles the data from two previous human intervention studies: a) a pilot study (n = 8), that compared the ingestion of de-alcoholised red wine (272 mL/day), red wine (272 mL/day), or gin (100 mL/day) during 20 days, and b) a large trial study (n = 41, 33 cases and 8 controls), that assessed variability among individuals after the intake of red wine (250 mL/day, 28 days). Great coincidence was observed in the main phenolic metabolites identified in the faecal samples from both studies that included benzoic acids, phenols, hippuric acids, phenylacetic acids, phenylpropionic acids, valeric acids, valerolactones and cinnamic acids. However, significant differences (P < 0.05) in the total phenolic content between faecal samples before and after the wine intervention was only observed for the large trial study (358 ± 270 and 625 ± 380 μg/g faeces, corresponding to the mean values before and after the intervention, respectively), emphasizing the large variability in the phenolic-metabolizing gut-microbial capacity among individuals. The overall results confirm that consumption of wine enhances phenolic metabolism, which might have physiological relevancy at the gut level.This work was funded by the MINECO (AGL2009-13361-C02-01, AGL2012- 04172-C02-01, and CONSOLIDER INGENIO 2010 (FUN-C-FOOD, CSD2007-063, Projects), and the Comunidad de Madrid (ALIBIRD P2009/AGR-1469 Project). AJ-G and IM-G would like to thank the European Social Fund and Jae-Doc (CSIC) and FPI Programs for their research contracts, respectively.Peer Reviewe

El consumo moderado y continuado de vino tinto promueve el metabolismo fenólico intestinal

Los polifenoles presentes en el vino son ampliamente metabolizados por la microbiota a lo largo del tracto gastrointestinal. Estos metabolitos fenólicos de origen microbiano parecen tener un papel relevante en los efectos beneficiosos para la salud derivados del consumo moderado de vino. Entre otros efectos, los polifenoles del vino y/o sus metabolitos pueden modificar o modular selectivamente la microbiota oral y del intestino. Con el objetivo de dilucidar como el consumo de vino afecta al metabolismo fenólico intestinal y conocer la relevancia fisiológica de estos efectos, se ha realizado un estudio de intervención en humanos que incluye a 41 voluntarios sanos (33 casos y 8 controles), basado en el consumo moderado (250mL/día) de vino tinto, durante 4 semanas. Antes y después de la intervención, se recolectaron muestras de heces procedentes de los voluntarios. El análisis de metabolitos fenólicos mediante UPLC-ESI-MS/MS ha revelado un aumento significativo en el contenido total de metabolitos de origen microbiano, principalmente de ácidos benzoicos y 4-hidroxivaléricos, en las heces de los voluntarios tras la ingesta de vino, lo que demuestra que el perfil metabólico microbiano de las heces se modifica significativamente por la ingesta moderada de polifenoles del vino.Los autores agradecen al MINECO y al CSlC la financiación obtenida para este estudio.Peer reviewe

Ultrafast characterization of the electron injection from CdSe quantum dots and dye N719 co-sensitizers into TiO2 using sulfide based ionic liquid for enhanced long term stability

Combination of inorganic quantum dots (QDs) and organic/metallorganic dyes as supracollectors nanocomposites could have an important role on the development of efficient photovoltaic devices based on the synergistic action of the hybrid-sensitizers. Here we have analyzed the combination of CdSe QDs and polypyridil N719 ruthenium dye. By ultrafast transient grating measurements we show that the cascading structure (type II) of this system takes full advantage to augment electron injection and hole regeneration efficiencies. Co-sensitized TiO2 electrodes lead to an improvement in charge separation, increasing the number of injected electrons from the CdSe QDs to the TiO2 as a consequence of the suppression of back reaction, by fast regeneration of holes by the dye action. The potentiality of this supracollector system has been verified in a complete cell configuration. Sulfide/polysulfide based ionic liquid in which both sensitizers (QD and dye) are stable has been employed as hole conducting media. In spite of the limited efficiencies of the analyzed cells, the higher photocurrents measured for CdSe/N719 co-sensitization compared to the cells sensitized using a single sensitizer constitutes a valid proof of the concept. Impedance spectroscopy unveiled the recombination limitation of the analyzed cells. On the other hand, ionic liquid exhibits an enhanced cell stability maintaining cell efficiency after one week and keeping it at 80% after 21 days. The reported results highlight a huge potential of the synergetic combination of QD and dyes for improving solar cell performance and of novel sulfide/polysulfide ionic liquid-based electrolytes for enhancing long term stability and sustainability of QD sensitizers

Simultaneous multi-frequency observation of the unknown redshift blazar PG 1553+113 in March-April 2008

© ESO 2010. The MAGIC collaboration would like to thank the Instituto de Astrofisica de Canarias for the excellent working condition at the Observatorio del Roque de los Muchachos at La Palma. Major support from Germany's Bundesministerium fur Bildung, Wissenschaft, Forschung und Technologie and Max-Planck-Gesellschaft, Italy's Istituto Nazionale di Fisica Nucleare (INFN) and Istituto Nazionale di Astrofisica (INAF), and Spain's Ministerio de Ciencia e Innovacion is gratefully acknowledged. The work was also supported by Switzerland's ETH Research grant TH34/043, Poland's Ministertwo Nauki i Szkolnictwa Wyzszego grant N N203 390834, and Germany's Young Investigator Program of the Helmholtz Gemeinschaft. This work was also supported by Georgian National Science Foundation grant GNSF/ST07/4-180. EP acknowledges support from the Italian Space Agency through grants ASI-INAF I/023/05/0 and ASI I/088/06/0. N.M. would like to thank to C.W. Danforth for the private communication regarding the newly estimated redshift of the source.The blazar PG 1553+113 is a well known TeV gamma-ray emitter. In this paper we determine its spectral energy distribution through simultaneous multi-frequency data to study its emission processes. An extensive campaign was carried out between March and April 2008, where optical, X-ray, high-energy (HE) gamma-ray, and very-high-energy (VHE) gamma-ray data were obtained with the KVA, Abastumani, REM, RossiXTE/ASM, AGILE and MAGIC telescopes, respectively. We combine the data to derive the source's spectral energy distribution and interpret its double-peaked shape within the framework of a synchrotron self-Compton model.Depto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUESwitzerland's ETHPoland's Ministertwo Nauki i Szkolnictwa WyzszegoHelmholtz GemeinschaftGeorgian National Science FoundationItalian Space Agencypu

Detection of very high energy radiation from the BL lacertae object PG 1553+113 with the MAGIC telescope

In 2005 and 2006, the MAGIC telescope observed very high energy gamma-ray emission from the distant BL Lac object PG 1553 + 113. The overall significance of the signal was 8.8 sigma for 18.8 hr of observation time. The light curve shows no significant flux variations on a daily timescale; the flux level during 2005 was, however, significantly higher compared to 2006. The differential energy spectrum between similar to 90 and 500 GeV is well described by a power law with photon index. Gamma = 4.2 +/- 0.3. The combined 2005 and 2006 energy spectrum provides an upper limit of z = 0.74 on the redshift of the object