217 research outputs found
Combined treatment of exudative age related macular degeneration with photodynamic therapy and intravitreal triamcinolone
Choroidal neovascularization (CNV) secondary to age related macular degeneration is among the leading causes of legal blindness in developed countries. Photodynamic therapy (PDT) with verteporfin induces CNV closure causing little damage to healthy tissue, but the need to re-treat may lead to low final visual acuity at an unacceptable cost. The association of intravitreous triamcinolone or antiangiogenic drugs with PDT has been used in order to reduce these limitations of the therapy. The combination of PDT and intravitreous triamcinolone, its complications and outcome at one and two-year follow-up are discussed
Análisis de aceites y grasas de fritura para producción de biodiesel
6 pages, 2 tables, 3 figures.[EN] Used frying fats and oils with highly variable and uncontrolled quality are used for the production of biodiesel. The objective of this study was to define the analytical methods useful to obtaining information on the quality of the used frying oils as raw material for biodiesels as well as for the characterization of the biodiesels obtained from them. Twentyfour used frying oils from restaurants and domestic fryers were analyzed before and after transesterification to fatty acid methyl esters (FAME). From a detailed analysis of the samples by means of a combination of adsorption and size exclusion
chromatography, the quantitative importance of polymeric compounds was deduced both from the direct analysis of the oils and from their FAME. Excellent linear correlation between polar compounds and polar FAME (R 0.9768) was found. The possibilities of interferences from polar fatty acid in the
standard method to determine the ester content are defined. Finally, determination of non-polar FAME by silica column is
proposed as a good alternative to the gas chromatography method.[ES] Los aceites y grasas de fritura, que se caracterizan por tener una calidad muy variable, se utilizan como material prima para la producción de biodiesel. El objetivo de este estudio es definir la utilidad de los métodos analíticos desarrollados para los aceites y grasas de fritura para caracterizar el biodiesel obtenido. Veinticuatro aceites de fritura procedentes del sector de restauración y de fritura doméstica fueron analizados antes y después de su transesterificación a ésteres metílicos de ácidos grasos. A partir de un análisis detallado mediante cromatografías de adsorción y exclusión, se deduce la importancia cuantitativa de los compuestos de polimerización tanto en el análisis directo de los aceites como en el análisis de los ésteres metílicos. Se encontró una excelente correlación lineal entre los compuestos polares y los ésteres metílicos polares (R=0.9768). Se definen las interferencias de los compuestos formados durante la fritura en el análisis estándar para conocer la calidad del biodiesel y se propone la determinación de ésteres metílicos no polares como una buena alternativa a la determinación cromatográfica estándar.This research work was supported by Junta de
Andalucía and MCYT (Project AGL 2004-00148).Peer reviewe
A preliminary study about treg cells phenotypic alteration
Las células T reguladoras son una subpoblación de los linfocitos T CD4+ de gran importancia en el establecimiento y mantenimiento de la tolerancia y la homeostasis del sistema inmune. Muchos estudios han analizado la frecuencia de las Treg en pacientes infectados por VIH. Sin embargo, los resultados no son concluyentes y existe una gran controversia sobre el papel que juegan las Treg en el curso de la infección. Recientemente se ha demostrado que el VIH puede infectar las células Treg. Trabajos previos de nuestro grupo demuestran que las Treg son susceptibles de infección por el VIH disminuyendo la expresión del Foxp3 en las células infectadas. Este fenómeno produce una alteración en la capacidad supresora de las células Treg. El objetivo de éste estudio es corroborar dicho comportamiento in vivo y determinar el fenotipo de las Treg en pacientes infectados por VIH. Los resultados preliminares indican que efectivamente la frecuencia de células Foxp3+ es inferior en los pacientes infectados por VIH que en los individuos sanos. El estudio sigue en curso para recopilar un número suficiente de muestras que permitan confirmar estos resultados. Este estudio permitirá conocer mejor el papel de las Treg en el curso de la infección por VIHRegulatory T cells (Treg) are a subpopulation of CD4+ T cells that play a crucial role in establishing and maintaining self-tolerance and immune homeostasis. Many studies have explored the frequency of Treg in HIV infected patients. However, there are controversial findings about the role of these cells in the HIV infection. Nowadays, different studies have showed that Treg cells are susceptible to the HIV infection. Our in vitro data has showed that HIV infects Treg and produces a downregulation of Foxp3 expression. This phenomenon also leads Treg cells to a loss of their immune suppressive capacity. The aim of this study is to corroborate if this behavior also occurs in vivo and determine the Treg phenotype in HIVinfected patients. Preliminary results indicate that frequency of Foxp3+ cells is lower in HIVinfected patients than in healthy volunteers. At present, we are recovering enough number of samples to confirm these results. A better understanding of these cells could serve for the effective exploitation of their suppressive functions for clinical benefit
Investigación de las ideas de los alumnos de enseñanza secundaria sobre la corriente eléctrica
This paper deals with the ideas on electric current of secondary education (BUP and COU) students who have been given traditional tuition. The study was based on operi-choice questionnaires, word-choice tests and concept trees. The results obtained show that the students' experiential and environmental models acquired from their everyday physical and social experience are preserved throughout their secondary education. However, their vocabulary gradually conforms to the cscientific model» of electric current
Protección de ácido ascórbico por antioxidantes sulfurados
A study was made of the protective effect that various sulphurated synthetic anti-oxidants produce with different concentrations in a watery solution of ascorbic acid. The oxidation process was accelerated by using temperatures of 40, 50 and 60°C and the corresponding parameters were calculated in agreement with a diminishing kinetics to the order of one.Se estudia el efecto protector que varios antioxidantes sintéticos sulfurados, ejercen a distintas concentraciones, sobre una solución acuosa de ácido ascórbico. Se acelera el proceso de oxidación, utilizando temperaturas de 40, 50 Y 60°C y se calculan los parámetros correspondientes de acuerdo con una cinética de degradación de orden uno
Estudio histomorfométrico del hueso diafísario en la rata
Se ha realizado un estudio histomorfométrico de la diálisis femoral en la rata
blanca cepa «Wistar» calculando las dimensiones del endostio y periostio, así como las modificaciones
de las áreas de la corteza, cavidad medular y hueso total en relación a la actividad
endóstica y perióstica del hueso durante el primer año de vida. Los resultados demuestran
un crecimiento discontinuo con una fase de enlentecimiento entre los 25 y 45 días de vida.
La evolución de los cambios diafisarios en la rata es superponible a la del hombre, considerándola
un animal de experimentación válido para estudiar los fenómenos de remodelación ósea
durante el crecimiento.A histomophometric study of the femoral diaphyseal bone was undertaken
in «Wistar» albine rat. Measurements of the endosteal and periosteal thickness as weel as
variations in cortical, medular and total bone areas in relation to the endosteal and periosteal
bone activity during the first year of life were analyzed. The results showed a continuous
growth increase with a phase of lower growth rate from the 25th to the 45th day of life.
The pattern of diaphyseal growing changes resembled that found in humans. The rat can
therefore be considered as a suitable experimental animal for the study of bone remodeling
during growth
Radiaciones solares: tipos y efectos
A review on solar radiation and its effect on skin has been made. Exposure to sunlight can have both beneficial and harmful effects on the human body, depending on the wavelenght and the frequency of exposure, the intensity of the sunlight and the sensitivity of the individual concerned. Solar radiation consists of a continuous spectrum of frequencies or wave lengths from the infrared through the visible light to the ultraviolet regio n and beyond.Se realiza una revisión bibliográfica sobre las características generales de radiaciones solares, especificando los tipos así como los efectos que producen sobre la piel. La exposición a la luz solar puede tener efectos adversos sobre el cuerpo humano siendo más o menos graves dependiendo de la longitud de onda y frecuencia de exposición
Homocistinuria y Acidemia Metilmalónica (CbIC) de evolución fatal en un recién nacido
La forma CblC de la Acidemia Metilmalónica (AMMC CbIC) es un error congénito del metabolismo intracelular de la cobalamina. Los síntomas clínicos consisten en descompensación neurológica y síntomas sistémicos. Describimos la evolución clínica y bioquímica en una paciente con inicio neonatal del defecto CblC. Recién nacido a termino, mujer, con peso al nacer de 2290 g. A los pocos día de vida presentó hipotonía, hipoactividad y succión dificultosa. Alos 13 días de vida se ingresó en UCIN presentando letargia, hipotonía, hipotermia y signos de afectación neurológica de tronco encefálico, además hiperlactacidemia y alteraciones del recuento celular. La RNM junto con los síntomas clínicos nos surgirieron una patología mitocondrial. Los ácidos orgánicos mostraron un importante aumento del ácido metilmalónico con homocistinemia y homocistinuria, sospechándose un defecto del metabolismo de la cobalamina que se comprobó in vitro. En el estudio mutacional se confirmó el diagnostico de AMM CbIC. A pesar de una buena respuesta bioquímica al tratamiento con cobalamina la paciente mantuvo un deterioro neurológico progresivo con éxitus a los 2 meses de vida. Se concluye que la AMMC, variante CblC, se puede presentar con retraso en el desarollo, lactacidemia y alteración en los parámetros hematológicos. A pesar de la normalización de los parámetros bioquímicos presentó una progresión de la enfermedad que la condujo al éxitus. Se especula la posibilidad de que existan otros factores fisiopatológicos que influyen en una mala evolución.The CblC form of methylmalonic acidemia with homocistinuria (MMA CblC) is a rare condition which results from impaired biosynthesis of methylcobalamin and adenosylcobalamin. The clinical phenotype implies neurological decompensation and systemic symptoms. We describe the clinical course and biochemical evolution of a girl with neonatal onset of the CblC variant. The female patient was delivered at term and weighed 2290 gr. The mother noticed hypotonia, hypoactivity and lack of sucking from very early on. At the 13 th day of life the patient was admitted to our hospital at the NICU. Lethargy, hypotonia, hipothermia, central ataxic breathing were the main symptoms. Initial blood profile pointed moderate hyperlactacidemia and alterations of blood cell count. RMN and the clinical profile suggested a mitochondrial disease. The metabolic profile, showed methylmalonic aciduria, with homocystinemia and homocystinuria suggesting a intracellular defect of cobalamin metabolism. The diagnosis of a MMA CbIC variant was confirmed by the propionate test in vitro and the genetic study. After treatment with cobalamin, levels of methylmalonic acid and homocysteine normalized, but the patient suffered progressive neurological deterioration with secondary multiorgan failure and death at two months of age. We conclude that Methylmalonic Aciduria with combined homocystinuria, CblC variant, may present with developmental delay, minor dysmorphology, moderate hyperlactacidemia and alteration of hematologic parameters. In spite of a normalization of biochemical parameters the disease led to a fatal outcome. We therefore think that in presence of a dysfunction of intracellular cobalamin, other physiological alterations leading to a fatal evolution might be possible
La experiencia de coordinación en el Grado de Maestro de Educación Infantil
The objective of this work was to disseminate the perception detected about the implementation of the Teaching Degree in pre-primary Education adapted to the EHEA and propose suggestions for improvement. It was performed through a SWOT analysis, to the teaching staff and students of the Faculty of Education and Social Work at the University of Valladolid. The data came from different assessments carried out by the Committee of Title during the first years of these studies, responding to one of the assigned competencies: To propose improvements in the educational program and in the services provided in the degree.El objeto de este trabajo fue dar a conocer la percepción detectada, sobre la implantación del Grado de Maestro en Educación Infantil adaptado al EEES y proponer sugerencias de mejora. Se realizó a través de un análisis DAFO, al profesorado y al alumnado de la Facultad de Educación y Trabajo Social de la Universidad de Valladolid. Los datos procedieron de diferentes evaluaciones llevadas a cabo por el Comité de Título durante los primeros cursos académicos de estos estudios, dando respuesta a una de las competencias asignadas: proponer mejoras en el programa formativo y en los servicios prestados en la titulación
Temporal changes in mediterranean pine forest biomass using synergy models of ALOS PALSAR-Sentinel 1-Landsat 8 Sensors
Currently, climate change requires the quantification of carbon stored in forest biomass. Synthetic aperture radar (SAR) data offers a significant advantage over other remote detection measurement methods in providing structural and biomass-related information about ecosystems. This study aimed to develop non-parametric Random Forest regression models to assess the changes in the aboveground forest biomass (AGB), basal area (G), and tree density (N) of Mediterranean pine forests by integrating ALOS-PALSAR, Sentinel 1, and Landsat 8 data. Variables selected from the Random Forest models were related to NDVI and optical textural variables. For 2015, the biomass models with the highest performance integrated ALS-ALOS2-Sentinel 1-Landsat 8 data (R2 = 0.59) by following the model using ALS data (R2 = 0.56), and ALOS2-Sentinel 1-Landsat 8 (R2 = 0.50). The validation set showed that R2 values vary from 0.55 (ALOS2-Sentinel 1-Landsat 8) to 0.60 (ALS-ALOS2-Sentinel 1-Landsat 8 model) with RMSE below 20 Mg ha−1. It is noteworthy that the individual Sentinel 1 (R2 = 0.49). and Landsat 8 (R2 = 0.47) models yielded equivalent results. For 2020, the AGB model ALOS2-Sentinel 1-Landsat 8 had a performance of R2 = 0.55 (validation R2 = 0.70) and a RMSE of 9.93 Mg ha−1. For the 2015 forest structural variables, Random Forest models, including ALOS PAL-SAR 2-Sentinel 1 Landsat 8 explained between 30% and 55% of the total variance, and for the 2020 models, they explained between 25% and 55%. Maps of the forests’ structural variables were generated for 2015 and 2020 to assess the changes during this period using the ALOS PALSAR 2-Sentinel 1-Landsat 8 model. Aboveground biomass (AGB), diameter at breast height (dbh), and dominant height (Ho) maps were consistent throughout the entire study area. However, the Random Forest models underestimated higher biomass levels (>100 Mg ha−1) and overestimated moderate biomass levels (30–45 Mg ha−1). The AGB change map showed values ranging from gains of 43.3 Mg ha−1 to losses of −68.8 Mg ha−1 during the study period. The integration of open-access satellite optical and SAR data can significantly enhance AGB estimates to achieve consistent and long-term monitoring of forest carbon dynamics
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