198 research outputs found

    An optoelectronic circuit with a light source, an optical waveguide and a sensor all on silicon: Results and analysis of a novel system

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    AbstractA full analysis of an optoelectronic circuit on silicon composed by a light emitter, an optical waveguide and a photodetector is achieved. The light emitter is based on silicon rich oxide multilayers. The multilayer structure exhibits an electroluminescence spectra from 400nm to 800nm. Light emitter and optical waveguide are located next to each other in a novel topology that allows the direct impact of the photons to the depletion layer of the sensor, increasing the efficiency. An optical rib-type waveguide and multi-modal, using Si3N4 and SiO2 as core and cladding materials, is considered to propagate the light from the light emitter to the sensor. Analysis of the waveguide reveals that the optimal height is 1.25µm, when a width of 5µm and a fractional height of 0.8 are used. A relative transmittance of the optical waveguide shows that the propagated light maintains the wide spectrum. A planar diode is used as photodetector. The proposal-integrated structure shows that light impinges directly on the depleted zone, improving detection and performance of the diode. Finally, a description of the novel optoelectronic circuit is addressed

    Silicon-Rich Oxide Obtained by Low-Pressure Chemical Vapor Deposition to Develop Silicon Light Sources

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    Off stoichiometric silicon oxide, also known as silicon-rich oxide (SRO), is a light-emitting material that is compatible with silicon technology; therefore, it is a good candidate to be used as a light source in all-silicon optoelectronic circuits. The SRO obtained by low-pressure chemical vapor deposition (LPCVD) has shown the best luminescent properties compared to other techniques. In spite of LPCVD being a simple technique, it is not a simple task to obtain SRO with exact silicon excess in a reliable and repetitive way. In this work, the expertise obtained in our group to obtain SRO by LPCVD with precise variation is presented. Also, the characteristics of this SRO obtained in our group are revised and discussed. It is demonstrated that LPCVD is an excellent technique to obtain single layers and multilayers of nanometric single layers with good characteristics

    MIS Transistor with Integrated Waveguide for Electrophotonics and the Effect of Channel Length in Light Detection

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    In this work, we study the optical response of MOS-like transistors with a Si3N4 integrated waveguide which serves also as the dielectric of the gate, and P-type substrate with 1´1012 cm-3 acceptor concentration and different channel length. Simulation results show the possibility to integrate this kind of MIS transistor as detectors in an electrophotonic circuit compatible with CMOS fabrication process and obtaining electrical gain for low power light signals (below 400 nW)

    Total nutritional therapy : a nutrition education program for physicians

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    Objetivo: Casi la mitad de todos los pacientes hospitalizados se encuentran desnutridos y los médicos tienen muy poco conocimiento o apenas utilizan el soporte nutricional1. Para corregir este problema, la Federación Latinoamericana de Nutrición Parenteral y Enteral (FELANPE) ideó un curso introductorio de nutrición clínica para médicos de dos días, con el apoyo de los Laboratorios Abbott. El objetivo del tratamiento nutricional total (TNT) es ayudar al médico a aprovechar sus conocimientos de nutrición para incrementar la conciencia sobre malnutrición y aplicación del tratamiento nutricional. Desde 1997, más de 8.000 médicos han completado el curso TNT en 16 países latinoamericanos. Métodos y procedimientos experimentales: Durante 1999 y 2000, 675 participantes respondieron, seis meses después de haber terminado el curso TNT, a una encuesta en la que se pretendía averiguar la repercusión que había tenido el curso en el uso de la evaluación nutricional, los equipos de apoyo nutricional o las consultas sobre nutrición en la práctica clínica y si habían participado en alguna asociación o conferencia de nutrición. Resultados: La mayoría de los médicos que rellenaron la encuesta había aumentado el uso de las herramientas de evaluación nutricional y el tiempo dedicado a este tratamiento; asimismo, había aumentado el número de pacientes que recibieron tratamiento nutricional. Conclusiones: El curso TNT ha resultado un modelo eficiente para la educación de los médicos generales en nutrición clínica. Este curso debería integrarse en la formación de los médicos residentes.Q4Q3Objective: Almost half of all hospitalized patients are malnourished with low physician awareness or implementation of nutrition support1. To address this problem, a 2-day immersion course in clinical nutrition for physicians was developed by the Latin American Federation of Parenteral and Enteral Nutrition (FELANPE) with support from Abbott Laboratories. The goal of Total Nutritional Therapy (TNT) is to help physicians utilize this nutrition knowledge to increase their awareness of malnutrition and implementation of nutritional therapy. Since 1997, over 8,000 physicians have completed the TNT course in 16 Latin American countries. Research Methods & Procedures: During 1999 and 2000, 675 participants responded to a survey 6 months after having completed the TNT course to determine what impact the course had on the use of nutrition assessment, nutrition support teams, or nutrition consultations in their clinical practice, and if they had participated in any nutrition association or conferences. Results: The majority of physicians who completed the survey increased their use of nutrition assessment and time dedicated to nutrition therapy, and increased the number of their patients placed on nutrition therapy. Conclusions: The TNT course has been shown to be an efficient model of clinical nutrition education for general physicians. The course should be considered as part of the training of medical residents.https://orcid.org/0000-0003-0401-0743N/

    Enfermedad del hígado graso no alcohólico, asociación con la enfermedad cardiovascular y tratamiento (I). Enfermedad del hígado graso no alcohólico y su asociación con la enfermedad cardiovascular

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    La enfermedad del hígado graso no alcohólico (EHGNA) comprende una serie de lesiones hepáticas histológicamente similares a las inducidas por el alcohol, en personas con un consumo del mismo muy escaso o nulo. La importancia de la EHGNA radica en su alta prevalencia en el mundo occidental y, desde el punto de vista hepático, en su progresiva evolución desde esteatosis a esteatohepatitis, cirrosis y cáncer de hígado. Durante la última década se ha observado que la EHGNA da lugar a un incremento del riesgo cardiovascular con aceleración de la arteriosclerosis y de los eventos a ella vinculados, principal causa de su morbimortalidad. Esta revisión actualizada a enero de 2016 consta de dos partes, analizando en esta primera parte la asociación de la EHGNA con la enfermedad cardiovascular. Non-alcoholic fatty liver disease (NAFLD) comprises a series of histologically lesions similar to those induced by alcohol consumption in people with very little or no liver damage. The importance of NAFLD is its high prevalence in the Western world and, from the point of view of the liver, in its gradual progression from steatosis to steatohepatitis, cirrhosis, and liver cancer. During the last decade it has been observed that NAFLD leads to an increased cardiovascular risk with acceleration of arteriosclerosis and events related to it, being the main cause of its morbidity and mortality. This review, updated to January 2016, consists of two parts, with the first part analysing the association of NAFLD with cardiovascular disease
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