551 research outputs found
Fabrication of gold nanowires on insulating substrates by field-induced mass transport
A method for the fabrication of nanometer size gold wires on insulating surfaces is presented. An oscillating gold-coated atomic force microscope tip is brought into close proximity of a silicon dioxide surface. The application of a negative sample voltage produces the transport of gold atoms from the tip to the surface. The voltage is applied when there is a tip–surface separation of ∼3 nm. The finite tip–surface separation enhances the tip lifetime. It also allows the application of sequences of multiple voltage pulses. Those sequences allow the fabrication of continuous nanowires. The atomic force microscope gold deposition is performed at room temperature and in ambient conditions which makes the method fully compatible with standard lithographic techniques. Electron transport measurements of the wires show a clear metallic behavior. Electrical resistivities of ∼ 3×10−7 Ω m and current densities of up to 5×1011 A m−2 are reported.This work was supported by the Dirección General de Enseñanza Superior e Investigación (PB98-0471) and the European Commission (MONA-LISA, GRD1-2000-25592).
One of the authors (M.C.) acknowledges financial support from the Comunidad de Madrid.Peer reviewe
Solar Ultraviolet Irradiance Characterization under All Sky Conditions in Burgos, Spain
Solar Ultraviolet Radiation (UVR), which is identified as a major environmental health
hazard, is responsible for a variety of photochemical reactions with direct effects on urban and
aquatic ecosystems, human health, plant growth, and the deterioration of industrial systems. Ground
measurements of total solar UVR are scarce, with low spatial and temporal coverage around the
world, which is mainly due to measurement equipment maintenance costs and the complexities of
equipment calibration routines; however, models designed to estimate ultraviolet rays from global
radiation measurements are frequently used alternatives. In an experimental campaign in Burgos,
Spain, between September 2020 and June 2022, average values of the ratio between horizontal global
ultraviolet irradiance (GHUV) and global horizontal irradiance (GHI) were determined, based on
measurements at ten-minute intervals. Sky cloudiness was the most influential factor in the ratio,
more so than any daily, monthly, or seasonal pattern. Both the CIE standard sky classification and the
clearness index were used to characterize the cloudiness conditions of homogeneous skies. Overcast
sky types presented the highest values of the ratio, whereas the clear sky categories presented
the lowest and most dispersed values, regardless of the criteria used for sky classification. The
main conclusion, for practical purposes, was that the ratio between GHUV and GHI can be used to
model GHUV.This research was funded by the Spanish Ministry of Science and Innovation, grant numbers RTI2018-098900-B-I00 and TED2021-131563B-I00, and Junta de Castilla y León, grant numbers INVESTUN/19/BU/0004 and INVESTUN/22/BU/0001
Adaptación transcultural y validación de la Rúbrica de Juicio Clínico de Lasater (RJCL ) en la docencia de Grado de Enfermería en el contexto educativo español.
Introducción: Tanner lo describe el juicio clínico como la interpretación acerca de las necesidades del paciente, a fin de tomar decisiones. Experiencia, habilidades y conocimiento son esenciales para emitir juicios clínicos adecuados.
Objetivos: Desarrollar la adaptación transcultural y validación de Rúbrica de Juicio Clínico de Lasater (RJCL) en la docencia de Grado de Enfermería y su implementación en el contexto educativo español. 1. Obtener una versión adaptada culturalmente al contexto educativo 2. Analizar la fiabilidad y validez de constructo en nuestro contexto. 3. Analizar posibles diferencias en las dimensiones medidas por RJCL en función distintos escenarios de simulación y de características de los estudiantes
Metodología: Estudio prospectivo observacional de validación psicométrica de la RJCL. Participantes estudiantes de 4º de Grado en Enfermería.Proceso de traducción y retrotraducción: Se han seguido las recomendaciones de ISPOR (International Society for Pharmacoeconomics and Outcomes Research) y PROMIS (Patient-Reported Outcomes Measurement Information System). La recogida de muestra se realizó durante la evaluación de competencias objetivas estructuradas en la Facultad de Ciencias de la Salud de la Universidad de Málaga.
Resultados: La versión adaptada fue evaluada sobre 76 alumnos/as (N=76), con dos observaciones en escenarios distintos, con evaluadores independientes para cada simulación (Número de observaciones= 152). El 70,9% de los alumnos fueron mujeres, edad media 23,91 (DE: 3,77).La fiabilidad interobservador, coeficiente de correlación intraclase, arrojó un valor de 0,93 (IC 95%: 0,92 a 0,95) (p=0,0001) para la puntuación total. Consistencia interna: El alpha de Cronbach obtenido fue de 0,93. Las correlaciones inter-items fueron de 0,570 de media (rango: 0,312 a 0,849). El índice de homogeneidad de la escala ofreció valores por encima de 0.5.Análisis factorial exploratorio: Mediante extracción del eje principal y rotación oblimin aportó 2 factores que explicaban un 72.86% de la varianza. La matriz de correlaciones entre ambos factores ofreció un r=0.536. Análisis factorial confirmatorio: El ajuste del modelo fue satisfactorio en todos los índices, con un valor 2/gl de 1.08, GFI de 0.96, TLI 0.99, NFI 0.97 y un RMSEA de 0.24 IC90%(0.000 a 0.066).
Conclusiones: 1. Se ha obtenido una versión adaptada culturalmente al contexto educativo español de la RJCL. 2. No se detectan diferencias en los escenarios de simulación y características de los estudiantes. 3. La RJCL traducida al español es un instrumento válido y fiable para la medición del juicio clínico de estudiantes de grado de enfermería. 4. En adelante sería recomendable realizar estudios prospectivos que permitan evaluar la sensibilidad al cambio, la trasferencia y el coste-beneficio de distintos diseños de simulación.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Este proyecto fue financiado por la Convocatoria 2015-2017 de Proyectos de Innovación Docente de la Universidad de Málaga (PIE 144-2015
Development of canopy vigour maps using UAV for site-specific management during vineyard spraying process
Site-specific management of crops represents an important improvement in terms of efficiency and efficacy of the different labours, and its implementation has experienced a large development in the last decades, especially for field crops. The particular case of the spray application process for what are called “specialty crops” (vineyard, orchard fruits, citrus, olive trees, etc.)FI-DGR grant from Generalitat de Catalunya (2018 FI_B1 00083).
Research and improvement of Dosaviña have been developed under LIFE PERFECT project: Pesticide Reduction using Friendly and Environmentally Controlled Technologies (LIFE17 ENV/ES/000205)This research was partially funded by the “Ajuts a les activitats de demostració (operació 01.02.01 de Transferència Tecnològica del Programa de desenvolupament rural de Catalunya 2014-2020)” and an FI-DGR grant from Generalitat de Catalunya (2018 FI_B1 00083). Research and improvement of Dosaviña have been developed under the LIFE PERFECT project: Pesticide Reduction using Friendly and Environmentally Controlled Technologies (LIFE17 ENV/ES/000205).This research was partially funded by the “Ajuts a les activitats de demostració (operació 01.02.01 de Transferència Tecnològica del Programa de desenvolupament rural de Catalunya 2014-2020)” and an FI-DGR grant from Generalitat de Catalunya (2018 FI_B1 00083). Research and improvement of Dosaviña have been developed under LIFE PERFECT project: Pesticide Reduction using Friendly and Environmentally Controlled Technologies (LIFE17 ENV/ES/000205)Postprint (updated version
Corpus based learning of stochastic, context-free grammars combined with Hidden Markov Models for tRNA modelling
[EN] In this paper, a new method for modelling tRNA secondary structures is presented. This method is based on the combination of stochastic context-free grammars (SCFG) and Hidden Markov Models (HMM). HMM are used to capture the local relations in the loops of the molecule (nonstructured regions) and SCFG are used to capture the long term relations between nucleotides of the arms (structured regions). Given annotated public databases, the HMM and SCFG models are learned by means of automatic inductive learning methods. Two SCFG learning methods have been explored. Both of them take advantage of the structural information associated with the training sequences: one of them is based on a stochastic version of the Sakakibara algorithm and the other one is based on a Corpus based algorithm. A final model is then obtained by merging of the HMM of the nonstructured regions and the SCFG of the structured regions. Finally, the performed experiments on the tRNA sequence corpus and the non-tRNA sequence corpus give significant results. Comparative experiments with another published method are also presented.We would like to thank Diego Linares and Joan Andreu Sanchez for answering all our questions about SCFG, as well as Satoshi Sekine for his evaluation software. We would also like to thank the Ministerio de Sanidad y Consumo of Spain for the grants to the INBIOMED consortium.García Gómez, JM.; Benedí Ruiz, JM.; Vicente Robledo, J.; Robles Viejo, M. (2005). Corpus based learning of stochastic, context-free grammars combined with Hidden Markov Models for tRNA modelling. International Journal of Bioinformatics Research and Applications. 1(3):305-318. doi:10.1504/IJBRA.2005.007908S3053181
Combined nanoscale KPFM characterization and device simulation for the evaluation of the MOSFET variability related to metal gate workfunction fluctuations
In this work, a more realistic approximation based on 2D nanoscale experimental data obtained on a metal layer is presented to investigate the impact of the metal gate polycrystallinity on the MOSFET variability. The nanoscale data (obtained with a Kelvin Probe Force Microscope, KPFM) were introduced in a device simulator to analyze the effect of a TiN metal gate work functions (WF) fluctuations on the MOSFET electrical characteristics. The results demonstrate that the device characteristics are affected not only by the WF fluctuations, but also their spatial distribution, which is specially relevant in very small devices. The effect on these characteristics of the spatial distribution on the gate area of such fluctuations is also evaluatedThis work has been partially supported by the Spanish AEI and ERDF (TEC2016-75151-C3-1-R, TEC2014-53909-REDT and RYC-2017-23312)S
Mitochondrial glutathione: Features, regulation and role in disease
El pdf del artículo es la versión post-print.[Background]: Mitochondria are the powerhouse of mammalian cells and the main source of reactive oxygen species (ROS) associated with oxygen consumption. In addition, they also play a strategic role in controlling the fate of cells through regulation of death pathways. Mitochondrial ROS production fulfills a signaling role through regulation of redox pathways, but also contributes to mitochondrial damage in a number of pathological states.
[Scope of review]: Mitochondria are exposed to the constant generation of oxidant species, and yet the organelle remains functional due to the existence of an armamentarium of antioxidant defense systems aimed to repair oxidative damage, of which mitochondrial glutathione (mGSH) is of particular relevance. Thus, the aim of the review is to cover the regulation of mGSH and its role in disease.
[Major conclusions]: Cumulating evidence over recent years has demonstrated the essential role for mGSH in mitochondrial physiology and disease. Despite its high concentration in the mitochondrial matrix, mitochondria lack the enzymes to synthesize GSH de novo, so that mGSH originates from cytosolic GSH via transport through specific mitochondrial carriers, which exhibit sensitivity to membrane dynamics. Depletion of mGSH sensitizes cells to stimuli leading to oxidative stress such as TNF, hypoxia or amyloid β-peptide, thereby contributing to disease pathogenesis.
[General significance]: Understanding the regulation of mGSH may provide novel insights to disease pathogenesis and toxicity and the opportunity to design therapeutic targets of intervention in cell death susceptibility and disease. This article is part of a Special Issue entitled Cellular functions of glutathione. © 2012 Elsevier B.V.The work was supported by grants: SAF2009-11417, SAF2010-15760, and SAF2011-23031 (Plan Nacional de I + D), Proyectos de Investigación en Salud PI10/02114 and PS09/00056 (Instituto de Salud Carlos III), P50-AA-11999 (Research Center for Liver and Pancreatic Diseases, US National Institute on Alcohol Abuse and Alcoholism) and by CIBEREHD from the Instituto de Salud Carlos III.Peer Reviewe
Photovoltaic Prediction Software: Evaluation with Real Data from Northern Spain
Prediction of energy production is crucial for the design and installation of PV plants. In
this study, five free and commercial software tools to predict photovoltaic energy production are
evaluated: RETScreen, Solar Advisor Model (SAM), PVGIS, PVSyst, and PV*SOL. The evaluation
involves a comparison of monthly and annually predicted data on energy supplied to the national
grid with real field data collected from three real PV plants. All the systems, located in Castile and
Leon (Spain), have three different tilting systems: fixed mounting, horizontal-axis tracking, and
dual-axis tracking. The last 12 years of operating data, from 2008 to 2020, are used in the evaluation.
Although the commercial software tools were easier to use and their installations could be described
in detail, their results were not appreciably superior. In annual global terms, the results hid poor
estimations throughout the year, where overestimations were compensated by underestimated
results. This fact was reflected in the monthly results: the software yielded overestimates during
the colder months, while the models showed better estimates during the warmer months. In most
studies, the deviation was below 10% when the annual results were analyzed. The accuracy of the
software was also reduced when the complexity of the dual-axis solar tracking systems replaced the
fixed installation.This research was funded by Spanish Ministry of Science and Innovation, grant number RTI2018-098900-B-I00 and the Regional Government of Castilla y León under the “Support Program for Recognized Research Groups of Public Universities of Castilla y León” (ORDEN EDU/667/2019) and “Health and Safety Program” (INVESTUN/19/BU/0004)
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