ABSTRACT
Se explora la evaluación del hipocinetismo como factor de riesgo para la salud. A tal fin fueron analizados los hábitos de actividad física y el nivel de riesgo cardiovascular, en 314 estudiantes no atletas de la Universidad Central de Venezuela con edades entre 17 y 29 a¤os, mediante la aplicación del Cuestionario Internacional de Actividad Física-IPAQ (2004) y un cuestionario de Hoeger y Hoeger (2002) para la estimación del riesgo cardiovascular. Los resultados indicaron que globalmente 31,53 por ciento de los sujetos tenían un nivel de actividad física que se relaciona con hipocinetismo. Se evidenció que las jóvenes estudiadas mostraron mayores niveles de riesgo cardiovascular. Se identificaron asociaciones entre las variables género y la categoría de riesgo cardiovascular, asícomo entre esta última y los niveles de actividad física, apuntando a que el hipocinetismo representa un factor de riesgo adicional en el desarrollo de enfermedades crónicas no transmisibles en los ucevistas evaluados.
Subject(s)
Humans , Male , Female , Physical Endurance , Physical Exertion , Students , Medicine , VenezuelaABSTRACT
The measurement of hepatic iron overload is of particular interest in cases of hereditary hemochromatosis or in patients subject to periodic blood transfusion. The measurement of plasma ferritin provides an indirect estimate but the usefulness of this method is limited by many common clinical conditions (inflammation, infection, etc). Liver biopsy provides the most quantitative direct measurement of iron content in the liver but the risk of the procedure limits its acceptability. This work studies the feasibility of a magnetic induction (MI) low-cost system to measure liver iron overload. The excitation magnetic field (B0, frequency: 28 kHz) was produced by a coil, the perturbation produced by the object (deltaB) was detected using a planar gradiometer. We measured ten patients and seven volunteers in supine and prone positions. Each subject was moved in a plane parallel to the gradiometer several times to estimate measurement repeatability. The real and imaginary parts of deltaB/B0 were measured. Plastic tanks filled with water, saline and ferric solutions were measured for calibration purposes. We used a finite element model to evaluate the experimental results. To estimate the iron content we used the ratio between the maximum values for real and imaginary parts of deltaB/B0 and the area formed by the Nyquist plot divided by the maximum imaginary part. Measurements in humans showed that the contribution of the permittivity is stronger than the contribution of the permeability produced by iron stores in the liver. Defined iron estimators show a limited correlation with expected iron content in patients (R < or = 0.56). A more precise control of geometry and position of the subjects and measurements at multiple frequencies would improve the method.
Subject(s)
Hemochromatosis/diagnosis , Liver , Magnetics/instrumentation , Computer Simulation , Humans , Models, Theoretical , Pilot ProjectsABSTRACT
Detalla aspectos sobre la calidad del agua, la contaminacion de la misma y tipo de contaminantes, complementando la informacion con ilustraciones. Manifiesta la relacion existente entre la cantidad y calidad del agua, analizando los parámetros involucrados en el balance ecológico: poblacion, urbanizacion, crecimiento económico y residuos químicos. Incluye pautas de manejo de la calidad del agua