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INTOXICACION POR HERBICIDA Y EL USO DE LA TIAMINA. UN ESTUDIO EXPERIMENTAL
Pérez-Pérez Elizabeth,Calderón de Cabrera Lourdes,Rodríguez-Malaver Antonio,Dmitrieva Natalia
Salud, Arte y Cuidado , 2012,
Abstract: Pesticide poisoning, accidental or intentional self-poisoning is a signi cant problem in many parts of the developing world. Paraquat is a compound that has been widely used as a non-selective contact herbicide since 1962. Ingestion of paraquat is a signi cant method ofself-poisoning in parts of Asia, Paci c islands, and Caribbean. Ingestion of large amounts is considered to be uniformly fatal, resulting in death from multi-organ; however, in smaller quantities, paraquat is speci cally taken up into and accumulates in the lung, and the redox cycling and free radical generation triggers a eutrophil-mediated in ammatory response in the lungs which initiates an irreversible brotic process that kills the majority of patientswithin several weeks. In this work, was studied the ability of thiamine to protect against Paraquat (PQ)-induced mortality and oxidative damage in rat liver. The medial lethal dose (LD50) for PQ was 32 mg/kg of body weight within 48 h. When thiamine (100 mg/kg) wasadministrated to PQ-treated rats, mortality was not observed. However, thiamine at 200 mg/kg did not modify mortality. For the oxidative stress study, the liver was obtained 24 h after Q-treatment and thiobarbituric acid reactive ubstances (TBARS) were measured.PQ induced a signi cant increase in TBARS levels and thiamine prevented this increase
Requerimiento de fósforo de los Microorganismos ruminales: una revisión
Ramírez-Pérez,Aurora H; Meschy,Fran?ois;
Interciencia , 2005,
Abstract: the effect of phosphorus (p) on microbial activity and the use of nutrients by the ruminant are described. recent recommendations on mineral feeding reduce dietary p concentration. phosphorus supply must satisfy the requirements of ruminal microbes in order to ensure an adequate fermentation process. microbial p requirements are greater for cellulose breakdown than for protein synthesis (6.9 vs 4.3g available p/kg of fermentable organic matter in the rumen). phosphorus utilization by bacteria depends on its dietary content, availability, and endogenous contribution through saliva, as well as on the microbial response to p variations in the ruminal content. due to these complexities, further investigation is needed. furthermore, any decrease in excreted p because of a reduction in its intake will have a positive effect on the environment.
Libido, pubertad, concentraciones séricas de testosterona y su relación con variables corporales y testiculares en futuros sementales Holstein - Libido, puberty, testosterone concentration and their relatitionship with body and testicular variables in Holstein future sires
Tamayo Torres, Manuel,Pérez, José Félix,Pérez-Pérez, Félix
REDVET , 2010,
Abstract: ResumenCon el objetivo de determinar la presentación de la libido, el arribo a la pubertad, las concentraciones séricas de testosterona y sus relaciones con variables corporales y testiculares en futuros sementales Holstein para su empleo en la selección como reproductores de los centros de inseminación artificial de Cuba; de 390 futuros sementales investigados, se evaluaron 120 de 1 a 12 meses de edad para este trabajo.SummaryOne hundred twenty Holstein future sires selected from a total of 390 bulls ranged from 1 to 12 months of age were evaluated in Havana province in this research. The animals were kept under a permanent housing system in the genetic station for breeding and selection.
El cuestionario CEVEAPEU. Un instrumento para la evaluación de las estrategias de aprendizaje de los estudiantes universitarios. [The CEVEAPEU Questionnaire. An instrument to assess the learning strategies of university students] .
Gargallo, Bernardo,Suárez-Rodríguez, Jesús M,Pérez-Pérez, Cruz
Revista Electrónica de Investigación y Evaluación Educativa , 2009,
Abstract: The objective of this work was to elaborate and validate a questionnaire to assess the learning strategies of university students more completely than those classically used. In order to do so, a design of test validation was used. Two samples of university students, the first one with 545 students and the second one with 1127, were used. The results of internal consistency, construct validity, predictive validity and temporal stability, included in the text of this paper, are good. The final product is a questionnaire with two scales, six subscales, twenty-five strategies and 88 items, more solid and complete than those previously available. El objetivo de este trabajo era elaborar y validar un cuestionario de evaluación de las estrategias de aprendizaje de los estudiantes universitarios más completo que los clásicamente utilizados. Para ello utilizamos un dise o de validación de pruebas. Usamos dos muestras de estudiantes universitarios, la primera de 545 estudiantes y la segunda de 1127. Los resultados de consistencia interna, validez de constructo, validez predictiva y estabilidad temporal, recogidos en el texto del artículo, son buenos. El producto final es un cuestionario con dos escalas, seis subescalas, veinticinco estrategias y 88 ítems, más sólido y completo que los anteriormente disponibles.
Germinación y establecimiento de Mimosa aculeaticarpa var. biuncifera (Fabaceae-Mimosoideae)
Pavón, Numa P.;Ballato-Santos, Jesús;Pérez-Pérez, Claudia;
Revista mexicana de biodiversidad , 2011,
Abstract: mimosa aculeaticarpa var. biuncifera, spiny drought-deciduous shrub has the potential to be used in restoration projects in degraded semi-arid areas of méxico. however, basic information that supports this does not exist. the objective of the study was to evaluate the germination conditions and establishment of this species. germination experiments were realized using 3 factors (scarification, light and temperature). also, seeds predation for bruquids was registered. we evaluated the effect of light and soil nitrogen on the establishment, for this we considered survival, growth and root nodulation of the shrub seedling. scarification and temperature were significant dormancy-breaking factors. seeds were not photoblastics and germinative parameters indicated that to 30o c the better results were obtained. seeds damaged by bruquids not germinate; the infestation was 26.8 % and 4 bruquids species were determined. on high brightness conditions, the highest seedling survival and root growth was registered. the nitrogen fertilization of soil had a significant negative effect on survival and growth of the shrub seedling. these results support the recommendation to use m. aculeaticarpa var. biuncifera in the restoration projects in degraded semi-arid areas in méxico.
Germinación y establecimiento de Mimosa aculeaticarpa var. biuncifera (Fabaceae-Mimosoideae) Seed germination and seedlings establishment of Mimosa aculeaticarpa var. biuncifera (Fabaceae-Mimosoideae)
Numa P. Pavón,Jesús Ballato-Santos,Claudia Pérez-Pérez
Revista mexicana de biodiversidad , 2011,
Abstract: El arbusto deciduo espinoso Mimosa aculeaticarpa var. biuncifera que se distribuye en las zonas semiáridas de México tiene potencial para usarse en proyectos de restauración ecológica; sin embargo, no existe información básica que sustente esta afirmación. Evaluar las condiciones óptimas de germinación y establecimiento de la especie fue el objetivo de este estudio. En cuanto a la germinación, se experimentó con 3 factores (escarificación, luz y temperatura) y adicionalmente se determinó la depredación por brúquidos. Para evaluar el establecimiento se midió el efecto de la luz y el nitrógeno en el suelo sobre la sobrevivencia, el crecimiento y la nodulación de las raíces de las plántulas. La escarificación y la temperatura fueron factores significativos en la germinación. Las semillas no fueron fotoblásticas y los parámetros germinativos indicaron que los mejores resultados de germinación se obtuvieron a 30o C. Las semillas da adas por los brúquidos no germinaron, la infestación fue de 26.8 % y se definieron 4 especies de brúquidos. La mayor sobrevivencia de plántulas y el mayor crecimiento de las raíces se registraron en condiciones de alta luminosidad. La fertilización del suelo con nitrógeno tuvo efecto negativo significante sobre la sobrevivencia y crecimiento de las plántulas. Estos resultados apoyan la recomendación de usar a M. aculeaticarpa var. biuncifera en proyectos de restauración de zonas semiáridas en México. Mimosa aculeaticarpa var. biuncifera, spiny drought-deciduous shrub has the potential to be used in restoration projects in degraded semi-arid areas of México. However, basic information that supports this does not exist. The objective of the study was to evaluate the germination conditions and establishment of this species. Germination experiments were realized using 3 factors (scarification, light and temperature). Also, seeds predation for bruquids was registered. We evaluated the effect of light and soil nitrogen on the establishment, for this we considered survival, growth and root nodulation of the shrub seedling. Scarification and temperature were significant dormancy-breaking factors. Seeds were not photoblastics and germinative parameters indicated that to 30o C the better results were obtained. Seeds damaged by bruquids not germinate; the infestation was 26.8 % and 4 bruquids species were determined. On high brightness conditions, the highest seedling survival and root growth was registered. The nitrogen fertilization of soil had a significant negative effect on survival and growth of the shrub seedling. These results suppor
Efecto de la aplicación de sulfato de calcio y materia orgánica sobre la incidencia de la pudrición apical de la guayaba (Psidium guajava L.) Effect of calcium sulfate and organic matter applying on the incidence of brown rot of guava (Psidium guajava L.)
E Pérez-Pérez,A Nava,C González,M Marin
Revista de la Facultad de Agronomía , 2008,
Abstract: La pudrición apical (PA) del fruto del guayabo (Psidium guajava L.) causada por el hongo Dothiorella sp., es una enfermedad ampliamente distribuida en Venezuela causando pérdidas en la producción nacional calculadas en 62%. Se determinó el efecto de la adición de sulfato de calcio y materia orgánica al suelo sobre la incidencia de la PA en una parcela experimental del Centro Frutícola del Zulia (CENFRUZU-CORPOZULIA) (10°49'46,6'' LN, 71°46'29,2'' LO), que consta de 204 plantas de guayabo de 12 a os de edad. Para el ensayo se seleccionaron 32 plantas por su uniformidad morfológica. Los tratamientos evaluados fueron: aplicación de 20 kg.planta-1 de materia orgánica (MO), 6 kg.planta-1 de sulfato de calcio, combinación de MO y sulfato de calcio en las dosis ya mencionadas y un testigo sin aplicación. Las variables evaluadas fueron: el número y la masa de los frutos, la incidencia de la pudrición apical (IPA), el contenido de N, P, K, Ca, Mg, Na y la textura de los frutos. Los tratamientos evaluados no afectaron la producción ni la IPA, sólo se observó diferencia para la IPA con relación al tiempo de muestreo, con el mayor valor en septiembre de 2006, tres meses después de un pico de precipitación. Los frutos enfermos presentaron el mayor valor de P, K y el menor valor de N, Ca y Mg a diferencia de los frutos sanos, y no hubo diferencias entre ellos con relación al contenido de Na y la textura. The brown rot in guava fruits caused by the fungus Dothiorella sp., is a widely distributed disease, producing 62% of damage in guava orchards in Venezuela. Calcium sulfate and organic matter effects on the brown rot incidence in guava fruit were determined in an experimental orchard of guava at Centro Frutícola del Zulia (CENFRUZU-CORPOZULIA) (10°49'47'', 31914 LN, 71°46'28'', 44742 LW), which has 204 guava trees of 12 years. 32 guava trees were selected by uniformed morphological characteristics for this essay. The evaluated treatments were: 20 kg.plant-1 of organic matter (OM), 6 kg.plant-1 calcium sulfate per plant, calcium sulfate and OM at mentioned doses and a control without OM and calcium sulfate application. The studied variables were: fruit production, brown rot incidence (BRI), fruit mineral content (N, P, K, Ca, Mg and Na) and fruit texture. The studied treatments did not affect the production and BRI, there was a difference between BRI and sampling time, the higher value of BRI was in September 2006, three months after a rain pick. The infected fruit showed higher the content of P, K, and the lower contents of N, Ca, and Mg, in contrast with healthy fru
Coexistence of two types of clinical lesions in childhood-onset mastocytosis
Pérez-Pérez Lidia,Allegue Francisco,Caeiro José,Fabeiro José
Indian Journal of Dermatology, Venereology and Leprology , 2011,
Abstract: The vast majority of mastocytosis appear in childhood, urticaria pigmentosa (UP) and mastocytomas being the most common types. Terms such as "xanthelasmoid mastocytosis", "pseudoxanthomatous mastocytosis" or "nodular mastocytosis" have been introduced in the literature to describe the presence of yellowish papular or nodular lesions. We describe two children with cutaneous mastocytosis showing yellowish lesions in combination with other skin lesions. A 10-year-old girl presented with asymptomatic lesions in her vulva at birth, and developed brownish macules on her trunk years after. An eight- year-old boy presented with multiple yellowish papular lesions on his trunk, neck and limbs coexisting with a few clinically anetodermic lesions. No systemic involvement was found and the skin biopsy confirmed a cutaneous mastocytosis in both cases. The two patients are currently asymptomatic and are being periodically followed up. Mastocytoses may show a variety of clinical lesions, sometimes leading to misdiagnosis. Although there are previous reports, involvement of the mucosae and secondary anetoderma are not common findings in cutaneous mastocytoses. We consider that cutaneous manifestations of mastocytoses compose a clinical spectrum, thus explaining the coexistence of different clinical lesions and the development of uncommon presentations.
Revisiones de código en el contexto del aseguramiento de calidad. Un caso práctico
M. J. Escalona,M. Pérez-Pérez,O. González-Barroso,J. Ponce
Revista Espa?ola de Innovación, Calidad e Ingeniería del Software , 2008,
Abstract: La verificación y validación del código es una de las actividades más críticas en los desarrollos de software que sirven para verificar la calidad de los productos que se generan. En la actualidad, los equipos de desarrollo y las oficinas de calidad demandan herramientas y entornos de referencia adecuados para esta verificación y validación. Hoy en día existen entornos de herramientas potentes y que permiten automatizar este tipo de tareas. En este trabajo se presenta una muy concreta, PMD, y se ofrece una visión de cómo se ha adaptado a diferentes proyectos reales.
Antimicrobial susceptibility of Helicobacter pylori and mechanisms of clarithromycin resistance in strains isolated from patients in Uruguay Susceptibilidad a los antomicrobianos Helicobacter pylori y mecanismo de resistencia a claritromicina en cepas aisladas de pacientes uruguayos
M. E. Torres-Debat,G. Pérez-Pérez,A. Olivares,L. Fernández
Revista Espa?ola de Enfermedades Digestivas , 2009,
Abstract: The prevalence and mechanisms of antibiotic resistance of Helicobacter pylori have not yet been investigated in Uruguay. The objective of this study was to assess the susceptibility of H. pylori to the most frequently used antibiotics and to determine the mechanism of resistance to clarithromycin. Seventy-nine isolates were obtained from gastric biopsies of 50 adult patients during two periods, 2001 and 2006. The former group enrolled the general population (GP), the latter group Afro-descendant (AD) subjects. The minimum inhibitory concentrations of clarithromycin, amoxicillin, tetracycline, metronidazole, and levofloxacin were determined using the E-test technique. Amplification was achieved through PCR and nucleic acid sequencing to detect mutations in the site of action of clarithromycin in the rRNA gene 23S. No amoxicillin or tetracycline-resistant strains were found. Clarithromycin resistance was found in 12% of the patients overall: 19.4% resistance in AD patients and no resistance in the GP group. This difference was statistically significant. The highest resistance was seen with metronidazole (36%), present in similar proportions in the two groups: 36.8% (GP) and 35.5% (AD). One GP patient and one AD patient had levofloxacin-resistant strains. Sequencing analysis of gene 23S rRNA showed that only mutation in position 2143 was presented in all clarithromycin-resistant strains.
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