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Search Results: 1 - 10 of 388710 matches for " R; López-López "
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Gill and Liver Histopathology in Goodea atripinnis Jordan, Related to Oxidative Stress in Yuriria Lake, Mexico
Ruiz-Picos,R; López-López,E;
International Journal of Morphology , 2012, DOI: 10.4067/S0717-95022012000300060
Abstract: in aquatic ecosystems, the complex mixture of pollutants may mediate the formation of free radicals and cause oxidative damage to the biota. yuriria lake (a ramsar site in central mexico) receives input of wastewater from its tributaries, agricultural runoff, and municipal discharge. we studied the lipid peroxidation (lpo), antioxidant enzymes (superoxide dismutase (sod), catalase (cat), and glutathione peroxidase (gpx), and histopathology of gill and liver of the native fish goodea atripinnis in yuriria lake. results were compared to a control group of fish cultivated in the laboratory. lpo, sod, and cat showed no significant differences compared to controls, but gpx showed greater and significant differences in both tissues. three class sizes were identified; organisms of classes i and ii had slight vasocongestion in the liver as compared to controls. hepatocytes of class iii showed cytoplasmic vacuolization, cellular disorganization, and the liver showed marked fibrosis compared to controls. gills of controls and classes i and ii showed no damage in gill filaments. tissue damage in class iii included hypertrophy, loss of the typical morphology, and edema in the gill filaments. the longer exposure of older organisms to yuriria lake conditions may have resulted in their poorer health condition.
Gill and Liver Histopathology in Goodea atripinnis Jordan, Related to Oxidative Stress in Yuriria Lake, Mexico Histopatología en las Branquias e Hígado de Goodea atripinnis Jordan, Relacionada con el Estrés Oxidativo en la Laguna Yuriria, México
R Ruiz-Picos,E López-López
International Journal of Morphology , 2012,
Abstract: In aquatic ecosystems, the complex mixture of pollutants may mediate the formation of free radicals and cause oxidative damage to the biota. Yuriria Lake (a Ramsar site in Central Mexico) receives input of wastewater from its tributaries, agricultural runoff, and municipal discharge. We studied the lipid peroxidation (LPO), antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and histopathology of gill and liver of the native fish Goodea atripinnis in Yuriria Lake. Results were compared to a control group of fish cultivated in the laboratory. LPO, SOD, and CAT showed no significant differences compared to controls, but GPx showed greater and significant differences in both tissues. Three class sizes were identified; organisms of classes I and II had slight vasocongestion in the liver as compared to controls. Hepatocytes of class III showed cytoplasmic vacuolization, cellular disorganization, and the liver showed marked fibrosis compared to controls. Gills of controls and classes I and II showed no damage in gill filaments. Tissue damage in class III included hypertrophy, loss of the typical morphology, and edema in the gill filaments. The longer exposure of older organisms to Yuriria Lake conditions may have resulted in their poorer health condition. En los ecosistemas acuáticos, la mezcla compleja de contaminantes presente puede mediar la producción de radicales libres y causar da o por estrés oxidativo a la biota. La laguna de Yuriria (sitio RAMSAR en la parte central de México) recibe aguas residuales de sus afluentes, escorrentías agrícolas y descargas municipales. Se estudió la peroxidación lipídica (LPO), las enzimas antioxidantes superóxido dismutasa, (SOD), catalasa (CAT) y glutatión peroxidasa (GPx); y la histopatología de las branquias e hígado del pez nativo Goodea atripinnis en la Laguna de Yuriria. Los resultados obtenidos fueron comparados con un grupo control de peces cultivados en laboratorio. La LPO, SOD y CAT no mostraron diferencia significativa en comparación con los controles; pero la GPx mostró diferencias significativas para ambos tejidos. Se identificaron tres clases de talla; los organismos de la clase I y II tuvieron una ligera vasocongestión en el hígado en comparación con los controles. Los hepatocitos de la clase III mostraron vacuolización citoplásmica, desorganización celular y el hígado mostró una marcada fibrosis. Las branquias de los organismos control y de las clases I y II no mostraron da o en sus filamentos. El da o tisular en los organismos de la clase III incluyó hipert
Titanato de circonio: estabilidad termodinámica y expansión térmica
López-López, E.,Moreno, R.,Baudín, C.
Boletín de la Sociedad Espa?ola de Cerámica y Vidrio , 2011, DOI: 10.3989/cyv.222011
Abstract: Zirconium titanate is a well known compound in the field of electroceramics, although it has also been used in catalyst and sensors applications. The crystallographic thermal expansion anisotropy of this compound makes it a potential candidate as constituent of structural components. In general, to assure the structural integrity and microstructural homogeneity of a ceramic piece, relatively low cooling rates from the fabrication temperature are required. This requirement is essential for zirconium titanate because thermal expansion as well as phase distribution is affected by small variations in the composition and cooling rate. This work reviews the available data on the phase equilibrium relationships in the systems ZrO2-TiO2 and ZrO2-TiO2-Y2O3. The main discrepancies as well as the possible origins of them are discussed. Additionally, the crystallographic thermal expansion data in the current literature are reviewed. El titanato de circonio es un compuesto muy usado en aplicaciones electrocerámicas, aunque también se han descrito aplicaciones en el campo de la catálisis y de los sensores. Dada la anisotropía en la expansión térmica cristalográfica de este compuesto, podría ser planteado como constituyente de componentes estructurales. En general, para asegurar la integridad estructural y la homogeneidad microestructural de una pieza cerámica, es preciso utilizar velocidades de enfriamiento desde la temperatura de fabricación relativamente bajas. Este requerimiento tiene una importancia fundamental en el titanato de circonio, ya que peque as variaciones en la composición y en la velocidad de enfriamiento, producen variaciones significativas tanto en la distribución de fases como en la expansión térmica. En este trabajo se revisan los trabajos existentes sobre la estabilidad del titanato de circonio dentro de los sistemas ZrO2-TiO2 y ZrO2-TiO2-Y2O3. Se describen las principales discrepancias acerca de las fases compatibles existentes en la bibliografía actual y se discute el posible origen de estas discrepancias. Asimismo, se revisan los datos existentes sobre la expansión térmica cristalográfica de este compuesto.
On the stability of magnetic colloids
M. T. López-López , G. R. Iglesias , J. D. G. Durán , F. González-Caballero
Annales UMCS, Chemistry , 2008, DOI: 10.2478/v10063-008-0026-3
Abstract: In this paper, the preparation of fluids belonging to ferrofluid (FF) and magnetorheological (MR) categories is described. Furthermore, the effect of different stabilizing additives (thixotropic agents, surfactants, magnetic nanoparticles) and carrier liquids on the sedimentation of these fluids is analyzed. These studies are conducted using: (i) optical and electromagnetic induction techniques for monitoring the stability of dilute and concentrated suspensions, respectively; (ii) contact angle and pendant drop measurements to explain the observed stability in different carriers. The results of these experiments are analyzed in detail and magnetic fluids with improved stability properties are prepared accordingly.
Análisis metacontingencial de la Ley de "Justicia y Paz" (975 de 2005) en Colombia
Daniel Del Río Forero,Diego Alejandro García,Luis Manuel Silva,Wilson López-López
Revista Latinoamericana de Psicología , 2012,
Abstract: Dentro de la perspectiva del análisis del comportamiento hay una joven pero fructífera tradición de estudio e intervención sobre prácticas culturales, que ha dado origen, entre otros, al concepto de metacontingencia, entendida en general como una relación funcional entre el comportamiento entrelazado de los individuos y un producto agregado determinado, operando en el tercer nivel (cultural) de selección. Al igual que la contingencia, que funciona en el segundo nivel de selección, es importante la especificación de sus términos para aumentar la posibilidad de influencia sobre la conducta. En este trabajo se pretendió hacer un análisis de la Ley de Justicia y Paz en Colombia en la búsqueda de estas especificaciones, las cuales revelaron que la escritura de la ley no se ajusta adecuadamente a los principios de especificación de contingencia. Se ofrecen sugerencias para seguir trabajando en esta dirección.
Osteonecrosis de maxilares asociada al uso de bifosfonatos: Revisión de 491 casos Osteonecrosis of the jaws associated with use of bisphosphonates: A review of 491 cases
S. Hernández Vigueras,E. Jané-Salas,R. Pérez Tomas,J. López-López
Avances en Odontoestomatología , 2012,
Abstract: En los últimos a os, el número de pacientes que presenta osteonecrosis maxilar asociada al uso de bifosfonatos (BIONJ) se ha incrementado. Esto es debido al aumento en el consumo de bifosfonatos, los cuales se asocian al tratamiento de carcinomas con metástasis óseas, mieloma múltiple, osteoporosis, osteopenia y enfermedades metabólicas como la enfermedad de Paget. Objetivo: Analizar el número de casos de pacientes que han desarrollado osteonecrosis de maxilares asociado al uso de bifosfonatos, publicados desde Junio del a o 2006 hasta Abril 2010. Método: En esta revisión, se consultaron las bases de datos Pubmed-Medline, Scielo e índice Médico Espa ol, incluyendo límites en la búsqueda, para recopilar los casos de BIONJ que se hayan publicado desde el a o 2006 hasta la actualidad. Los artículos seleccionados presentaban casos, en los cuales los pacientes que recibían bifosfonatos desarrollaban BIONJ. Resultados: Se encontraron 491 casos de BIONJ en total, de ellos 49,3% eran mujeres, 32% hombres y 18,7% no se establecía el género. La mayoría de estos casos se presentaron en la mandíbula y asociados particularmente al ácido zolendrónico. Conclusiones: En los próximos a os se espera que el número de pacientes que desarrollen esta complicación vaya en aumento, en particular en mujeres, a las cuales se les indica cada vez más esta medicación para el tratamiento de la osteoporosis. In the last years, the number of patients presenting jaw osteonecrosis associated with the use of bisphosphonates (BIONJ) has increased. This is due to increased consumption of bisphosphonates, which are associated with the treatment of carcinomas with bone metastases, multiple myeloma, osteoporosis, osteopenia and metabolic diseases such as Paget′s disease. The aim of this review is to analyze the number of cases of patients who developed jaws osteonecrosis-associated with the use of bisphosphonates, published from June 2006 to April 2010. In this review, we referred to the databases Pubmed-Medline, Scielo and Spanish Medical Index, including limits on the search to collect BIONJ cases published from 2006 up to now. The selected papers presented cases in which the patients who received bisphosphonates developed BIONJ. We found 491 cases of BIONJ in total, of which 49.3% correspond to women, 32% to men and 18.7%, did not establish gender. Most of these cases occurred in the mandible and associated particularly with zoledronic acid. In the coming years it is expected that the number of patients who develop this complication increase, particularly in women, who are more and more pr
Balance hídrico y clasificación climática del estado de Tabasco, México
Ruiz-álvarez, O;Arteaga-Ramírez, R;Vázquez-Pe?a, MA;Ontiveros Capurata, RE;López-López, R;
Universidad y ciencia , 2012,
Abstract: this study focused on the water balance and climatic classification of the state of tabasco, in order to define seasons and regions with a deficit or a surplus of moisture and to classify the climate of the state following thornthwaite's method. of the weather stations in the state, 40 were selected that provided average monthly values of temperature and rainfall. the others did not record these two variables. of the 40 stations, 25 also had evaporation data. two methods were used to calculate the reference evapotranspiration (et0): the hargreaves and the evaporation pan. the first was used in the 40 stations and the second in the 25 stations that had evaporation data (the et0 was also calculated with the hargreaves method for these last). a linear model was generated with 20 of the 25 stations, comparing the et0hargreaves data with the et0tanque data. the remaining five stations were used to determine the accuracy of the model. the model corrected the et0hargreaves calculated for the 15 stations with no evaporation data. the thornthwaite-mather type climatic water balance was calculated from the reference evapotranspiration and the rainfall. four regions with different moisture were identified. the greatest surplus was located in the south of the state, and the poblado c32 station presented the greatest annual deficit. the moisture indices obtained identified five types of climate for the state of tabasco.
La estimulación eléctrica del sistema nervioso central con finalidad analgésica
López-López,J. A.;
Revista de la Sociedad Espa?ola del Dolor , 2006,
Abstract: different procedures using electricity for pain control (mainly neuropathic) are described in this review. history of the so-called utility of electricity for pain control, describing the early attempts at the xviii century and their evolution. spinal cord stimulation: how does it works, patient?s selection, implant techniques, how to do the different procedures and complications and their management are described. brain stimulation: the same scheme as above, concerning both deep brain stimulation and motor cortex stimulation.
La estimulación eléctrica del sistema nervioso central con finalidad analgésica The electrical stimulation of the central nervous system for pain control
J. A. López-López
Revista de la Sociedad Espa?ola del Dolor , 2006,
Abstract: Esta revisión pretende orientar al lector sobre los procedimientos empleados para el control del dolor crónico, preferentemente neuropático, por medio de la electricidad. Historia de la utilización de la electricidad con finalidad analgésica, con descripción de los usos primitivos en el siglo XVIII y su evolución. Estimulación eléctrica medular: Se describen los mecanismos de acción, la selección de los pacientes, las técnicas de implante, la forma de realización de los diferentes procedimientos y sus complicaciones y el manejo de las mismas. Estimulación cerebral: Se sigue el mismo esquema que en el apartado anterior, diferenciándose en dos apartados: la estimulación cerebral profunda y la estimulación de la corteza prefrontal. Different procedures using electricity for pain control (mainly neuropathic) are described in this review. History of the so-called utility of electricity for pain control, describing the early attempts at the XVIII century and their evolution. Spinal cord stimulation: How does it works, patient’s selection, implant techniques, how to do the different procedures and complications and their management are described. Brain stimulation: The same scheme as above, concerning both Deep Brain Stimulation and Motor Cortex Stimulation.
Producción de tomate de cáscara (Physalis ixocarpa Brot.) basado en láminas de riego y acolchado plástico
López-López, R.;Arteaga-Ramírez, R.;Vázquez-Pe?a, M. A.;López-Cruz, I. L.;Sánchez-Cohen, I.;
Revista Chapingo. Serie horticultura , 2009,
Abstract: among the main problems that limit production and productivity of husk tomato are the availability and high cost of irrigation water, as well as inefficient use of this resource. current production systems are not efficient due to, among other reasons, the large volumes of water supplied. the objectives of this study were to assess the effect of different irrigation water treatments and plastic mulching on husk tomato crop production in a fertigation system and also to optimize the irrigation water in order to improve crop productivity. the experiment consisted of a complete randomized design with three replicates, with a 5 x 2 factorial treatment design consisting of five levels of irrigation: 40, 60, 80, 100 and 120% of reference evapotranspiration calculated using the penman-monteith equation, and two levels of plastic mulching, with and without. the results indicate that there were significant differences between mulching and irrigation levels for fruit yield and water productivity. using plastic mulching increased fruit yield by 56.6%, and irrigation water efficiency by 57.3%; water use was reduced 60% by calculating the required water volume with the penman-monteith equation.
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