oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 763 )

2018 ( 1046 )

2017 ( 989 )

2016 ( 1464 )

Custom range...

Search Results: 1 - 10 of 592462 matches for " María N; Vera "
All listed articles are free for downloading (OA Articles)
Page 1 /592462
Display every page Item
Picaduras de medusas:actualización: An update Jellyfish sting
Cristián Vera K,Marianne Kolbach R,María Soledad Zegpi T,Francisco Vera K
Revista médica de Chile , 2004,
Abstract: Jellyfishes are aquatic organisms, whose number increases under certain conditions of water temperature. They can sting humans, which can be fatal. The liberation of structures known as nematocysts induces the extrusion of the poison, to attack their victims. The poison produces characteristic local and systemic reactions. Since an increased number of these organisms has been detected in our coastline, we review the epidemiology, symptoms and diagnosis of the syndrome produced by the bite, to improve its management (Rev Méd Chile 2004; 132: 233-41)
On-line methodology for the trace level determination of the chlorinated phenol family in water samples
Nú?ez-Gaytán, Ana María;Vera-ávila, Luz Elena;Covarrubias-Herrera, María del Rosario;
Journal of the Mexican Chemical Society , 2008,
Abstract: on-line solid-phase extraction - liquid chromatography (spe-hplc) methodology was developed for the trace level determination of phenol and 19 chlorophenols in water samples. a small precolumn packed with polymeric adsorbent was placed in a switching valve and used for sample extraction and preconcentration; the trapped compounds were further on-line eluted and analyzed by reversed phase hplc with uv and coulometric detection. because of wide differences in hydrophobic character, spe of the least (phenol and monochlophenols), the medium (di- and trichlorophenols) and the most chlorinated phenols (tetra- and pentachlorophenol) was performed using different sample volume (15-25 ml) and sample composition (0-10% methanol addition). under these conditions, solute recoveries were ≥ 82% (except phenol, 72%) for concentrations in the range ~3-75 ng/ml. applying recovery factors, excellent accuracy (100%) and precision (rsd < 6.5%) were achieved for the 20 compounds of interest in replicate analysis (n = 7) of spiked reagent water samples. method detection limits were 0.5-1 ng/ml with the uv detector and 0.1-0.3 ng/ml with the coulometric detector.
On-line methodology for the trace level determination of the chlorinated phenol family in water samples
Ana María Nú?ez-Gaytán,Luz Elena Vera-ávila,María del Rosario Covarrubias-Herrera
Revista de la Sociedad Química de México , 2008,
Abstract: Se desarrolló una metodología basada en el acoplamiento en línea de la extracción en fase sólida y la cromatografía de líquidos (EFS-CLAR), para la determinación de fenol y 19 clorofenoles al nivel de trazas en muestras de agua. La extracción y preconcentración de las muestras se realizó en una peque a precolumna empacada con adsorbente polimérico y colocada en una válvula de conmutación; posteriormente, los compuestos atrapados fueron eluidos en línea y analizados por CLAR en fase reversa con detección UV y coulombimétrica. Debido a las grandes diferencias en carácter hidrofóbico, la EFS de los fenoles menos clorados (fenol y monoclorofenoles), los medianamente clorados (di- y triclorofenoles) y los más clorados (tetra- y pentaclorofenol) se realizó usando diferente volumen (15-25 mL) y composición de muestra (0-10% de metanol adicionado). Con estas condiciones la recuperación de los solutos fue 82% (excepto fenol, 72%) para concentraciones en el intervalo de ~3-75 ng/mL. Aplicando factores de recuperación, se obtuvo una excelente exactitud (100%) y precisión (< 6.5%) para los 20 compuestos de interés en análisis replicados (n = 7) de muestras de agua pura fortificadas. Los límites de detección del método fueron de 0.5-1 ng/mL con el detector UV y de 0.1-0.3 ng/mL con el detector coulombimétrico.
Diagnóstico de neumocistosis en pacientes oncológicos por la técnica de inmunofluorescencia directa
Moreno Calderón,Xiomara; Reviákina,Vera; Panizo,María Mercedes; León,Mirtiliano;
Revista Venezolana de Oncología , 2010,
Abstract: the patient with malignancy disease has a high risk to develop respiratory infections for pneumocystis jirovecii pneumonia. investigations about pneumocystosis in oncological patients in venezuela are scarce. the objective of this work was to detect pneumocystis jirovecii in oncological patients by the method of direct immunofluorescence technique. thirty one respiratory specimens (bronchoalveolar lavage, spontaneous and induced sputum, and tracheal aspirates) received in 10 months, 8 specimens of them (25.5) were positive the distribution by malignancy disease was the following: 18 solid tumors, and 13 leukemias, and lymphomas. no statistically significant differences were found between the studied groups and positive results (p>0.05). the complementary laboratory tests, related to the presence of pneumocystis, were not statistically significant either p>0.05). is necessary to include this diagnosis in the microbiological differential study of low respiratory tract infections in oncological patients, since these patients show unspecific symptoms, and have a high possibility to develop pneumocystosis.
Diagnóstico de neumocistosis en pacientes oncológicos por la técnica de inmunofluorescencia directa
Xiomara Moreno Calderón,Vera Reviákina,María Mercedes Panizo,Mirtiliano León
Revista Venezolana de Oncología , 2010,
Abstract: El paciente con enfermedades oncológicas tiene un alto riesgo para desarrollar infecciones respiratorias, y neumonía por Pneumocystis jirovecii. En Venezuela existen pocos estudios sobre la neumocistosis en pacientes oncológicos. El objetivo de este trabajo fue detectar la presencia de Pneumocystis jirovecii en pacientes oncológicos a través de la técnica de inmunofluorescencia directa. Se recibieron, durante 10 meses, 31 muestras respiratorias (lavado broncoalveolar, esputo espontáneo e inducido, aspirados traqueales), de ellas 8 (25,5 %) resultaron positivas. La distribución por tipo de cáncer fue la siguiente: 18 tumores sólidos y 13 leucemias y linfomas. La positividad entre los grupos estudiados no fue estadísticamente significativa (P>0,05). Los exámenes de laboratorio complementarios, relacionados tampoco fueron estadísticamente significativos (P>0,05). Es necesario incluir este diagnóstico en estudio microbiológico diferencial de infecciones del tracto respiratorio inferior en pacientes con cáncer, estos pacientes cursan con una sintomatología general inespecífica y tendrán una alta posibilidad de desarrollar neumocistosis. The patient with malignancy disease has a high risk to develop respiratory infections for Pneumocystis jirovecii pneumonia. Investigations about pneumocystosis in oncological patients in Venezuela are scarce. The objective of this work was to detect Pneumocystis jirovecii in oncological patients by the method of direct immunofluorescence technique. Thirty one respiratory specimens (bronchoalveolar lavage, spontaneous and induced sputum, and tracheal aspirates) received in 10 months, 8 specimens of them (25.5) were positive the distribution by malignancy disease was the following: 18 solid tumors, and 13 leukemias, and lymphomas. No statistically significant differences were found between the studied groups and positive results (P>0.05). The complementary laboratory tests, related to the presence of Pneumocystis, were not statistically significant either P>0.05). Is necessary to include this diagnosis in the microbiological differential study of low respiratory tract infections in oncological patients, since these patients show unspecific symptoms, and have a high possibility to develop pneumocystosis.
Internalizing Environmental Costs on the road freight transport industry
Vera Ferrón Vílchez,Juan Alberto Aragón Correa,María Dolores Vidal Salazar
Cuadernos de Gestión , 2011,
Abstract: Prior literature noted the potential that advanced environmental management might have in the generation of valuable organizational capabilities regarding costs minimization. More-over, during last years, one of the most important objectives in the development of transport public policies has been the internalization of environmental costs. Thus, this study attempts, firstly, to analyze how transport companies could successfully face the challenge of internalis-ing environmental costs, and second, to highlight how the existence of an environmentally proactive pattern of behaviour might reduce the environmental costs on transport sector. In doing so, a case study in the Spanish industry of road freight transport has been elaborated. Despite nowadays companies face the environmental challenge not beyond legal require-ments, the main conclusion of this study is that an environmentally proactive behaviour re-inforces the sustainable development of companies.
Picaduras de medusas:actualización: An update
Vera K,Cristián; Kolbach R,Marianne; Zegpi T,María Soledad; Vera K,Francisco; Lonza J,Juan Pedro;
Revista médica de Chile , 2004, DOI: 10.4067/S0034-98872004000200014
Abstract: jellyfishes are aquatic organisms, whose number increases under certain conditions of water temperature. they can sting humans, which can be fatal. the liberation of structures known as nematocysts induces the extrusion of the poison, to attack their victims. the poison produces characteristic local and systemic reactions. since an increased number of these organisms has been detected in our coastline, we review the epidemiology, symptoms and diagnosis of the syndrome produced by the bite, to improve its management (rev méd chile 2004; 132: 233-41)
Caracterización de los sistemas de producción porcina en las principales regiones porcicolas colombianas Caracteriza o dos sistemas de produ o de suínos nas principais regi es suínas da Col mbia Characterization of pig farms in the main swine producing regions of Colombia
Carlos A Díaz,María N Rodríguez,Víctor J Vera,Gloria Ramírez
Revista Colombiana de Ciencias Pecuarias , 2011,
Abstract: El presente estudio tuvo como objeto caracterizar productivamente las granjas porcícolas colombianas de producción intensiva con más de 200 hembras en el pie de cría en las tres regiones con mayor influencia sobre la producción nacional lo cual representó el 62% del inventario nacional de madres. Se seleccionó aleatoriamente una muestra de 67 granjas con un nivel de confianza del 95%, una precisión del 10% y una variabilidad del 50%. Se aplicó una encuesta para estimar los principales indicadores sanitarios y de productividad en cada una de las etapas de producción: aclimatización, cría, precebo y ceba. Se establecieron las diferencias de los indicadores entre las regiones evaluadas (p<0.05) y se obtuvo una aproximación al desempe o productivo de las granjas identificando las fortalezas y debilidades de los sistemas en las regiones estudiadas. En promedio se estimó que las granjas tienen una tasa de parición del 87.6%, un promedio de 11.7 lechones nacidos totales, 10.8 lechones nacidos vivos y 10 lechones destetos por cerda; producen 22.3 lechones por cerda al a o y sacrifican animales de 102 kg de peso con 166.1 días al sacrificio en promedio. Los resultados obtenidos demostraron que los indicadores de competitividad son similares a los reportados en otros países e inclusive superiores, siendo importante considerar que la porcicultura colombiana está en capacidad de disminuir costos de producción asociados al incremento en el número de cerdos y kilogramos producidos por cerda al a o. Este estudo teve como objectivo caracterizar produtivamente as empresas suínas com mais de e 200 fêmeas reprodutoras em três regi es com maior influência nacional, que representaram 62% do inventário nacional das m es. Foi seleccionada aleatoreamente uma amostra de 67 granjas com um nível de confian a de 95%, uma precis o de 10% e uma variabilidade de 50%. Um inquérito foi utilizado para estimar indicadores de saúde e produtividade em todas as fases de produ o: aclimata o, cria, reprodu o, pré engorda e engorda. Foram encontradas diferencias entre granjas nos indicadores entre as regi es avaliadas (p<0.05) e obteve-se uma aproxima o do desempenho produtivo das granjas identificando-se os pontos fortes e fracos dos sistemas nas regi es estudadas. Em média as granjas agrícolas apresentaram uma taxa de natalidade do 87.6%, 11.7 leit es nascidos totais, 10.8 leit es nascidos vivos e 10 leit es desmamados por porca, produzidos 22.3 leit es por porca por ano e o abate foi de 102 kg com 166.1 dias. Os resultados mostraram que os indicadores da competitividade s o semelhantes a
Secuencia de infección viral asociada al embarazo durante brote de dengue en Santiago de Cuba, 2006
López Barroso,Reinaldo; Macias Navarro,Meidys María; Guzmán Tirado,María G; álvarez Vera,Mayling;
Revista Cubana de Medicina Tropical , 2011,
Abstract: introduction: several dengue outbreaks have taken place in santiago de cuba province in the last few years, in which pregnant women have been involved. objectives: to determine the immunity and to describe the role of dengue infection and its sequence. methods: an observational and descriptive study was conducted to characterize dengue immunity in mothers and children after 10 and 12 months of birth and to determine the influence of certain viral infection sequences in pregnant women who suffered this disease during the dengue 3 epidemics in santiago de cuba. to this end, serum samples from 25 females tested dengue 3-positive and from children born to them after 10 and 12 months of childbirth were studied. igg titers and viral infection sequences were determined and analyzed according to the world health organization dengue classification criteria. results: the children did not present with the antibodies and the viral infection sequences associated to mothers; in order of frequency, the same percentage was observed in den2/den3, den1/den2/den3 (21,74 %); but lower percentage in den1/den3 (17,39 %). conclusions: the children did not develop humoral immunity (igg) despite some manifestations inherent to the disease. the secondary infections prompted the most serious forms of the disease.
Secuencia de infección viral asociada al embarazo durante brote de dengue en Santiago de Cuba, 2006 Sequence of viral infection associated to pregnancy in a dengue outbreak in Santiago de Cuba in 2006
Reinaldo López Barroso,Meidys María Macias Navarro,María G Guzmán Tirado,Mayling álvarez Vera
Revista Cubana de Medicina Tropical , 2011,
Abstract: Introducción: en la provincia Santiago de Cuba se han producido diferentes epidemias de dengue en los últimos a os, donde han estado incluidas mujeres en estado de gravidez. Objetivo: conocer la inmunidad y describir el papel de la infección con dengue, así como su secuencia. Métodos: se realizó un estudio observacional y descriptivo para caracterizar la inmunidad a dengue en las madres e hijos después de 10 y 12 meses de nacidos y conocer la influencia de determinadas secuencias de infección virales en las mujeres embarazadas que sufrieron la enfermedad, durante la epidemia de dengue 3, en Santiago de Cuba. Para ello se estudiaron las muestras de suero de 25 mujeres confirmadas de dengue 3 y de los ni os nacidos de estas, al cabo de los 10 y 12 meses de nacidos. Se determinaron los títulos de IgG y las secuencias virales de infección; se analizaron según la clasificación del dengue de acuerdo con el criterio de la Organización Mundial de la Salud. Resultados: los ni os no presentaron anticuerpos y las secuencias virales de infección asociadas a las madres en orden de frecuencia resultaron con igual porcentaje el DEN2/DEN3, DEN1/DEN2/DEN3 (21,74 %) y en menor porcentaje por último el DEN1/DEN3 (17,39 %). Conclusiones: los ni os no desarrollaron inmunidad humoral (IgG), a pesar de que algunos presentaron manifestaciones propias de la enfermedad. Las infecciones secundarias favorecieron las formas graves de la entidad. Introduction: several dengue outbreaks have taken place in Santiago de Cuba province in the last few years, in which pregnant women have been involved. Objectives: to determine the immunity and to describe the role of dengue infection and its sequence. Methods: an observational and descriptive study was conducted to characterize dengue immunity in mothers and children after 10 and 12 months of birth and to determine the influence of certain viral infection sequences in pregnant women who suffered this disease during the dengue 3 epidemics in Santiago de Cuba. To this end, serum samples from 25 females tested dengue 3-positive and from children born to them after 10 and 12 months of childbirth were studied. IgG titers and viral infection sequences were determined and analyzed according to the World Health Organization dengue classification criteria. Results: the children did not present with the antibodies and the viral infection sequences associated to mothers; in order of frequency, the same percentage was observed in DEN2/DEN3, DEN1/DEN2/DEN3 (21,74 %); but lower percentage in DEN1/DEN3 (17,39 %). Conclusions: the children did not develop
Page 1 /592462
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.