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Search Results: 1 - 10 of 758521 matches for " J. A. López-López "
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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.
Liquid phase micro-extraction: Towards the green methodology for ultratrace metals determination in aquatic ecosystems
López-López J. A.,Vergel C.,Mendiguchía C.,Pinto J. J.
E3S Web of Conferences , 2013, DOI: 10.1051/e3sconf/20130109002
Abstract: Heavy metals are normally found, in natural waters, in very low concentrations. Some of them are essential for life in low level; however, in higher level they are toxic. Therefore, analyzing their bio-available fraction is of main interest. Standard methodology is based in the collection of a number of samples from a water body. Collected samples must be stored, pre-treated and then analyzed. Pre-treatment usually involves pre-concentrating the metal, with the corresponding risk of contamination or loss of analyte. This way, punctual information is obtained from every sampling campaign. As an alternative, passive sampling techniques allow the continuous and coupled sampling-pre-treatment for heavy metals analysis, giving a better approach in the characterization of the studied water body. Liquid phase micro-extraction (LPME) is a green analytical alternative for liquid-liquid extraction that promotes a reduction of sample volume, solvent needed and waste generation. Using these systems, polypropylene hollow fibers (HF) with pores in their walls can be used. A few micro-liters of organic solvent are supported in the pores. The sample is placed in the outer part of the fiber and a receiving phase is placed in its inner part, allowing continuous liquid extraction of the metal from the sample. Several fibers with different physical features have been employed to analyzed total concentration and bio-availability of some heavy metals (Ag, Ni, Cu) in natural water samples. Thanks to fibers configuration, devices for passive sampling based in HF-LPME could be designed. Advantages of this methodology over existing ones are supported because the receiving phase is liquid. As a consequence, retained metals do not need to be eluted from the acceptor prior to instrumental analysis.
Assessing pollution trends in the Guadalquivir River estuary using N-way analysis
López-López J. A.,Mendiguchía C.,García-Vargas M.,Moreno C.
E3S Web of Conferences , 2013, DOI: 10.1051/e3sconf/20130124005
Abstract: Human activities have contributed to a deployment of environmental quality. In the last decades the problem of water preservation has gained increasing attention, and new policies have been developed for water resources remediation. Statistical techniques for data treatment are based on the organization of data in a bi-dimensional array; thus, some shades on the trend of the distribution tend to be ignored. Multiway techniques, where data are gathered in n directions, allow the analysis of the results through different directions at the same time. In particular, for 3MPCA a principal components analysis is conducted using three modes and a “core” matrix that allows assessing their interactions. The Guadalquivir River estuary has been used as a model system for the application of 3MPCA in the study of long term evolution of pollutants. Nutrients and heavy metals ultra-traces level have been used to characterize the estuary. The 3MPCA was used to assess the relationships within chemical variables, sampling stations and sampling campaigns.
Efecto de los tratamientos antirretrovirales en las manifestaciones orales de los pacientes VIH+
Jané-Salas,E.; Chimenos-Küstner,E.; López-López,J.; Roselló-Llabrés,X.; Oca?a-Rivera,I.;
Avances en Odontoestomatología , 2006, DOI: 10.4321/S0213-12852006000600003
Abstract: we evaluate the effects of antiretroviral treatments in hiv seropositive patients, who were seen in the clinic for infectious diseases in the vall d′hebron hospital, barcelona. 90 patients were seen, 51 males (56.7%) and 39 females (43.3%), the mean age of the patients was 36.2 years with a deviation of ±17.8, and a mode of 35 years. the visits were carried out between january and december 1999. these patients were receiving antiretroviral treatment with one or more drugs and some of them (32.2%) were subjected to high activity antiretroviral treatment (haart). also, in these patients the cd4 count and bimodal viral load was measured, at the start of the disease process and at the time of visit. theoral cavity was examined at this time, in search of lesions associated with aids according to the classification by pindborg et al, 1989. the most prevalent pathology found in this study was the sensation of dry mouth or xerostomia in 47.8%, followed by, in order of frequency, multiple caries (34.4%) and erythematous candidiasis (31.1%). other oral manifestations are very rare, in comparison with the results of other authors in the time before the use of protease inhibitors (pi). there is, for example, only one case of leukoplakia, so characteristic before 1996.
Fertilización con nitrógeno, fósforo y potasio en un latizal de Pinus patula Schl. et Cham
Lázaro-Dzul, Martha O;Velázquez-Mendoza, Juan;Vargas-Hernández, José J;Gómez-Guerrero, Armando;álvarez-Sánchez, María E;López-López, Miguel A;
Revista Chapingo. Serie ciencias forestales y del ambiente , 2012, DOI: 10.5154/r.rchscfa.2011.01.001
Abstract: the forests today face the problem of productivity; it is demanded to increase in quantity and quality. forest growth depends on several factors, including soil, which acts on the tree by the water and mineral elements. forest productivity is increased by improving nutrient availability through fertilization. consequently, this research is aimed to study the nitrogen fertilization (0, 138, 185), phosphorus (0, 15, 21), and potassium (0, 123, 164) kg·ha-1 compared to the growth of new foliage, using a 33 factorial experiment in a pinus patula schl. et cham plantation of 10 year old trees, in aquixtla, puebla, during 2009-2010. the instantaneous relative growth rate (tcri, by its acronym in spanish) in terms of new growth was better (0.0255 ml·ml-1·day-1) with a 185-0-0 kg·ha-1 npk dose; and tcri dry weight was better (0.0254 and 0.0249 g·g-1·day-1, respectively) with a 138-0-0 and 138-0-123 dose. nitrogen deficiency was determined, which was attributed to soil acidity and the slow mineralization of organic matter. the recommended dose for soil and climatic conditions of the experimental site was 185-0-0 kg·ha-1 for volume of new foliage and 138-0-0 npk kg·ha-1 for dry weight.
UNDERSTANDING THE CORROSION BEHAVIOR OF 35Ni19Cr ALLOY USING X-RAY MICROANALYSIS
Wong-Moreno,A; López-López,D; Martínez,L;
Revista Latinoamericana de Metalurgia y Materiales , 2001,
Abstract: x-ray microanalysis of corroded specimens of 35ni19cr austenitic steel was performed in order to understand its oil-ash corrosion behavior. corrosion testing involved the exposure of the alloy at temperatures in the range of 600°c - 900°c, to a sulfate-rich oil ash, which is also constituted by low melting point sodium vanadates. the curve describing the corrosion behavior as a function of temperature exhibits two relative maximums at 715°c and around 800°c, suggesting that there is an evolution of corrosion mechanisms as temperature is increased. x-ray microanalysis of the corrosion product scale and of the metal subjacent to the interface metal/scale let characterize three corrosion mechanisms prevailing along the temperature range: metallic dissolution caused by molten vanadium compounds, accelerated oxidation and sulfidation. microanalysis also provided evidence of internal degradation at temperatures above 675°c consisting in internal oxidation, sulfidation or both. it was concluded that the resultant corrosion behavior depends on both: the oxidation, oil-ash corrosion and sulfidation resistance of the alloy, and the stability of the oil ash, which determines the chemical compounds responsible for the corrosion process observed.
UNDERSTANDING THE CORROSION BEHAVIOR OF 35Ni19Cr ALLOY USING X-RAY MICROANALYSIS
A Wong-Moreno,D López-López,L Martínez
Revista Latinoamericana de Metalurgia y Materiales , 2001,
Abstract: X-ray microanalysis of corroded specimens of 35Ni19Cr austenitic steel was performed in order to understand its oil-ash corrosion behavior. Corrosion testing involved the exposure of the alloy at temperatures in the range of 600°C - 900°C, to a sulfate-rich oil ash, which is also constituted by low melting point sodium vanadates. The curve describing the corrosion behavior as a function of temperature exhibits two relative maximums at 715°C and around 800°C, suggesting that there is an evolution of corrosion mechanisms as temperature is increased. X-ray microanalysis of the corrosion product scale and of the metal subjacent to the interface metal/scale let characterize three corrosion mechanisms prevailing along the temperature range: metallic dissolution caused by molten vanadium compounds, accelerated oxidation and sulfidation. Microanalysis also provided evidence of internal degradation at temperatures above 675°C consisting in internal oxidation, sulfidation or both. It was concluded that the resultant corrosion behavior depends on both: the oxidation, oil-ash corrosion and sulfidation resistance of the alloy, and the stability of the oil ash, which determines the chemical compounds responsible for the corrosion process observed. Se llevó a cabo un estudio por microanálisis de especímenes corroídos de acero austenítico 35Ni19Cr con el fin de entender su comportamiento de corrosión por cenizas de combustóleo. Los ensayos de corrosión involucraron la exposición de la aleación a temperaturas en el intervalo de 600°C - 900°C, a un depósito de ceniza con alto contenido de sulfatos alcalinos y que también está constituido por vanadatos de sodio de bajo punto de fusión. La curva que describe el comportamiento de corrosión en función de la temperatura exhibe dos máximos relativos a 715°C y alrededor de 800°C, lo cual sugiere que hay una evolución de los mecanismos de corrosión operantes a medida que la temperatura se incrementa. Los resultados del estudio por microanálisis de la costra de productos de corrosión y del metal debajo de la interfaz metal/costra, permitió caracterizar los tres mecanismos de corrosión operantes a lo largo del intervalo de temperatura considerado: disolución metálica causada por compuestos de vanadio de bajo punto de fusión, oxidación acelerada y sulfidación. El microanálisis de las probetas corroídas proporcionó evidencia de la ocurrencia de degradación interna de la aleación a temperaturas mayores a 675°C, la cual consiste de oxidación interna, sulfidación o ambas. Se concluye que el comportamiento de corrosión resultante depend
El papel de las variables cognitivo-conductuales y sensoriales en la predicción de la capacidad funcional y la interferencia en la actividad en una muestra de personas mayores con dolor crónico
López-López,A.; Montorio Cerrato,I.; Fernández de Troconiz,M. Izal;
Revista de la Sociedad Espa?ola del Dolor , 2010,
Abstract: objective: the aim of this work is twofold. the first is to analyse how cognitive-behavioural and perceptual variables help to explain functional disability in older people with chronic pain caused by osteoarthritis. the second is to determine how functional disability can help to explain the interference of pain in daily activity and how cognitive-behavioural and sensorial variables contribute to the prediction of interference, once functional capacity is controlled. material and methods: one hundred and four persons aged over 65 (85.6% women, 14.4% men; 51.9% living in the community, 48.1% nursing homes) were assessed in the variables intensity, frequency and duration of pain, pain beliefs, self-efficacy, coping style, coping strategies, pain behaviours, functional disability and pain interference with daily activities. for each dependent variable, the data were analysed in two stages. firstly, we employed backward regression analysis, then we carried out hierarchical regression analysis using the variables for which significant differences were found, and controlling for socio-demographic and clinical variables. to predict interference, an additional second step, including functional disability, was added to the equation. results and conclusions: the results suggest that there is a profile of variables that can help to explain functional disability: advanced age, a high degree of radiological affectation, avoidance behaviours, pain catastrophizing and stability beliefs. with regard to the prediction of pain interference, once the effect of the socio-demographic and clinical variables has been controlled, only self-affirmation and active coping remain significant. functional capacity loses its predictive significance as soon as the cognitive-behavioural variables are included in the equation. in general, the analyses show the prevailing role of behavioural elements of active coping in the extent to which pain interferes in activity, over and above that of disease-
El papel de las variables cognitivo-conductuales y sensoriales en la predicción de la capacidad funcional y la interferencia en la actividad en una muestra de personas mayores con dolor crónico The role of cognitive-behavioural and sensorial variables to explain functional capacity and pain interference in a sample of older people with chronic pain
A. López-López,I. Montorio Cerrato,M. Izal Fernández de Troconiz
Revista de la Sociedad Espa?ola del Dolor , 2010,
Abstract: Objetivos: El presente estudio persigue un doble objetivo. Primero, identificar las variables cognitivo-conductuales que ayudan a predecir la capacidad funcional para las actividades de la vida diaria de las personas mayores con dolor crónico relacionado con artrosis. Segundo, determinar el papel de la capacidad funcional en la interferencia del dolor, así como la capacidad predictora de las variables cognitivo-conductuales, toda vez controlado el efecto de aquélla. Material y método: Se evaluó a 104 personas mayores (85,6% mujeres, 14,4% varones; 51,9% en comunidad, 48,1% en centros residenciales), con una edad media de 74,32 a os, en las variables: intensidad, frecuencia y duración del dolor, estilo y estrategias de afrontamiento, conductas de dolor, creencias, autoeficacia, discapacidad funcional (actividad de la vida diaria) e interferencia del dolor en las actividades cotidianas. Se realizaron 2 tipos de análisis para cada variable dependiente: análisis de regresión por eliminación regresiva y análisis de regresión jerárquica, controlando variables sociodemográficas y clínicas. En el caso de la interferencia se a adió un segundo bloque con la capacidad funcional. Resultados y conclusiones: La capacidad funcional puede predecirse en un 51% por un modelo que contemple tanto variables cognitivo-conductuales, como relativas a la enfermedad, tales como afectación radiológica, evitación, catastrofismo y creencias de estabilidad. La autoafirmación y el afrontamiento activo predicen la interferencia del dolor en las actividades cotidianas, una vez controlado el efecto de las variables sociodemográficas y clínicas. El valor predictivo de la capacidad funcional en la interferencia pierde su significación una vez que se tienen en cuenta en la ecuación las variables cognitivo-conductuales. En general, los análisis muestran el papel preponderante de los elementos conductuales de afrontamiento activo en la interferencia del dolor, por encima de las variables relativas a la enfermedad, lo que pone de manifiesto la importancia del entrenamiento en este tipo de estrategias en las personas mayores con dolor articular. Objective: The aim of this work is twofold. The first is to analyse how cognitive-behavioural and perceptual variables help to explain functional disability in older people with chronic pain caused by osteoarthritis. The second is to determine how functional disability can help to explain the interference of pain in daily activity and how cognitive-behavioural and sensorial variables contribute to the prediction of interference, once functional capacity
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