oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 5 )

2019 ( 428 )

2018 ( 530 )

2017 ( 546 )

Custom range...

Search Results: 1 - 10 of 353059 matches for " Félix Fernández Martín "
All listed articles are free for downloading (OA Articles)
Page 1 /353059
Display every page Item
Predicativity through transfinite reflection
Andrés Cordon Franco,David Fernández Duque,Joost J. Joosten,Félix Lara Martín
Mathematics , 2014,
Abstract: Peano Arithmetic is known to be provably equivalent to reflection over Elementary Arithmetic. We prove a characterization of Predicative Analysis in the guise of ATR0 in terms of stronger reflection principles.
Estudio comparativo del comportamiento de seis cepas de hongos micorrízicos arbusculares en su interacción con el tomate (Lycopersicon esculentum M. var Amalia )
Yakelin Rodríguez Yon,Blanca de la Noval Pons,Félix Fernández Martín,Pedro Rodríguez Hernández
Ecología Aplicada , 2004,
Abstract: Dada la extraordinaria importancia ecológica y económica de los hongos micorrízicos arbusculares (HMA), en Cuba y otros países, se han dado pasos acelerados para poner en práctica su uso como biofertilizante. En el presente trabajo se realizó un estudio comparativo del comportamiento de seis cepas de HMA, en su interacción con plántulas de tomate de la variedad Amalia , mediante indicadores fúngicos, agronómicos y bioquímicos con el objetivo de evaluar las diferencias existentes en los patrones de colonización de las distintas cepas y seleccionar la más promisoria para este cultivo en las condiciones estudiadas. Las cepas de HMA estudiadas fueron Glomus fasciculatum, G. clarum, G. mosseae, Glomus sp.1, G. intrarradices y Acaulospora scrobiculata. A los 18 y 32 días de germinadas las semillas se evaluó: altura; masa fresca y seca (aérea, radical y total) y la actividad específica radical de quitinasa, β-1,3-glucanasa y fenilalanina amonio liasa (PAL); así como las variables fúngicas colonización (%) y densidad visual (%) a los 32 días. En sentido general, se encontró un efecto positivo de la inoculación sobre las plántulas de tomate con respecto a los controles, expresado en los indicadores agronómicos y fúngicos estudiados. Los resultados mostraron además respuestas diferenciadas de las plántulas de tomate en función de las cepas de HMA inoculadas, con relación a las actividades enzimáticas, destacándose la cepa Glomus fasciculatum como la más efectiva para esta interacción en las condiciones estudiadas.
Asociación de lupus eritematoso sistémico y esclerosis múltiple: esclerosis lupoide. Descripción de cuatro casos
Medina,Yimy F; Martínez,José B; Fernández,Andrés R; Quintana,Gerardo; Restrepo,José Félix; Rondón,Federico; Iglesias Gamarra,Antonio;
Revista Colombiana de Reumatología , 2010,
Abstract: multiple sclerosis (ms) and systemic lupus erythematosus (sle) with/without antiphospholipid syndrome are autoinmune illnesses. it has been described in many occasions the association of these two illnesses and the clinical picture of ms with characteristics of laboratory of sle. when they affect to the central nervous system they can make it in a defined form for each illness or they can also make it in interposed or combined form of the two illnesses what has been called lupoid sclerosis; making that in some cases difficult the differentiation of the two illnesses and therefore to address the treatment. we present four cases of lupoid sclerosis, discuss the clinical and laboratory characteristics of this entity and we make a differentiation of the multiple sclerosis with the neurological affectation of sle especially for images and laboratory results.
Manifestaciones renales y neuropsiquiátricas en pacientes con lupus eritematoso sistémico y anticuerpos anti-P ribosomal
Quintana,Gerardo; Rojas,Cilia; Restrepo,José Félix; Fernández,Andrés; Martínez,José; Rondón,Federico; Sánchez,álvaro; Iglesias,Antonio;
Revista Colombiana de Reumatología , 2006,
Abstract: summary the ribosomal p protein autoantibodies are present in approximately 15% of patients with systemic lupus erythematosus (sle). these antibodies were initially associated with lupus psychosis and neuropsychiatric diseases. posteriorly, they were associated to a higher risk of renal and liver involvement in patients with sle. objective: to evaluate the serologic and clinic coexistence of ribosomal p protein autoantibodies and anti-dsdna in patients with sle with renal and neuropsychiatric manifestations. materials and methods: cases: 12 patients with neuropsychiatric and renal involvement (behavior changes 6, depression 4, hallucinations 3, cognitive impairment 2, seizures 2 and psychosis 2). controls: 13 patients with active sle, without evidence of neuropsychiatric manifestations. sle was active in all patients during the process of evaluations. the anti-ribosomal p protein antibodies were determined by elisa and the dsdna antibodies by crithidia luciliae′s immunofluorescence test. the renal function was evaluated by serum creatinin and urinalyses. results: the median age was 39 years, 2 men/23 women. 8 cases (66.6%) and 7 controls (53.8 %) have renal involvement. 20% of patients were positive for anti p-ribosomal antibodies (5/25 patients: 2 controls and 3 cases). 36% of patients have anti dsdna antibodies (30.7% controls and 41.6% cases). the presence of anti-ribosomal p protein antibodies was associated with anti dsdna antibodies (p = 0.002) and with lupus nephritis (p = 0.046), but no association between ribosomal p protein autoantibodies and neuropsychiatric manifestations was found (p = 0.645). conclusions: the p-ribosomal antibodies are associated with anti-dsdna and lupus nephritis. this study did not show statistically significant associations between ribosomal p protein autoantibodies and neuropsychiatric manifestations in patients with sle.
Asesoría cubana ante un aumento de casos de malaria en dos departamentos de Haití en abril de 2010
Fuster Callaba,Carlos A; Ponce Cárdenas,Félix; Fonseca Lozada,Juan Miguel; Velásquez Martín,Martha; Cox Iraola,Raimundo; Marquetti Fernández,María del Carmen;
Revista Cubana de Medicina Tropical , 2011,
Abstract: introduction: malaria is considered to be a serious health problem in haití, mainly in the rural zones of the coastal area located at 600 m above the sea level, particularly shallow zones with rice crops. objective: to describe the actions taken in four sites of two haitian departments to face the rise of the number of malarial cases. methods: the advisory work was carried out in three communities located in the west department and one in nippes department in april 2010. fever screenings along with sample-taking for thick smear test were performed as well as anti-vector activities including search for breeding sites and thermal treatment in the house and out of it. results: it was confirmed in this thick smear test that not all the persons presenting with febrile symptoms suffered malaria since low positive values to this disease were obtained. during this study, only plasmodium falciparum was diagnosed. out of the 46 breeding sites, 26 were positive to anopheles albimanus. the impact of insecticidal treatment could not be assessed since the areas did not have preliminary data on this respect. conclusions: these results provide the malaria control program with pieces of knowledge about the distribution and control of vectors in addition to emphasizing the need of making an updated stratification of the incidence of the disease that comprises all the aspects of the malaria control program in haiti.
Contribución al estudio de la criptococosis infantil en Cuba Contribution to the study of infant cryptococosis in Cuba
María Teresa Illnait Zaragozí,Gerardo Félix Martínez Machín,Carlos Manuel Fernández Andreu,Juan José Marchena Bequer
Revista Cubana de Medicina Tropical , 2013,
Abstract: Introducción: a partir de 1998 en el laboratorio de micología del Instituto "Pedro Kourí" se observó un incremento del número de aislamientos de Cryptococcus obtenidos de ni os seronegativos al VIH con meningoencefalitis. Los reportes de criptococosis infantil a nivel mundial son infrecuentes y generalmente se encuentran asociados al sida. Objetivo: estudiar la criptococosis infantil en Cuba a través de la evaluación integral de 7 casos. Métodos: se realizó un estudio retrospectivo integral, se revisaron las historias clínicas de 7 pacientes pediátricos afectados por criptococosis menigoencefálica y se caracterizaron los aislamientos obtenidos (uno de cada paciente). A estos se les determinó la especie, variedad, serotipo, patogenicidad en un modelo murino y susceptibilidad a la anfotericina B. Resultados: la edad media de los ni os fue de 5,8 a os, con ligero predominio del sexo femenino (4:3). Los síntomas más frecuentes resultaron la cefalea, fotofobia, fiebre y los vómitos. En 6 pacientes el estudio citoquímico del líquido cefalorraquídeo y el examen imaginológico de cráneo evidenciaron anomalías. El diagnóstico microbiológico se realizó mediante examen directo y cultivo. Todos los aislamientos correspondieron con Cryptococcus neoformans serotipo A y la anfotericina B mostró una concentración mínima inhibitoria menor o igual que 0,125 mg/mL. El 85,7 % mostró actividad fenoloxidasa y elevada letalidad en los animales infectados (71,4-100 %). Conclusiones: el pronóstico de la meningoencefalitis por Cryptococcus está estrechamente ligado a un diagnóstico precoz. Esta realidad hace que deba tenerse siempre presente, por lo que los datos aportados bien pudieran servir de alerta a los médicos de asistencia. Introduction: since 1998, an increasing number of Cryptococcus isolates obtained from HIV-negative children with meningoencephalitis was observed in the mycology laboratory at "Pedro Kourí" Institute. The global reports of child cryptococcosis are rare and usually associated with AIDS. Objectives: to study child cryptococosis in Cuba through the comprehensive evaluation of 7 cases. Methods: the clinical histories of seven pediatric patients with cryptococcal meningoencephalitis were examined and the obtained isolates (one per patient) were characterized. The species, variety, serotype, pathogenicity in a mouse model and amphotericin B susceptibility of the isolates were determined. Results: average age of the children was 5.8 years, with a slight female predominance (4:3). The most common symptoms were headache, photophobia, fever and vomiting. The cyt
Prevalencia de desnutrición en menores de cinco a?os de Tabasco
Lastra-Escudero,Lucio G.; Roldán-Fernández,Silvia G.; Hernández-Martínez,Enrique; Hernández-Torres,Alma Patricia; Lechuga-Padrón,Félix Gerardo;
Salud Pública de México , 1998, DOI: 10.1590/S0036-36341998000500004
Abstract: objective. to evaluate malnutrition prevalence in children under five years-old in tabasco, mexico, during 1996, and their evolution in 1991-1996. material and methods. a cross-sectional study, including 1 256 children under five years-old in 593 communities (31 urban and 562 rural) from 17 sanitary districts. results. the weight/age indicator for malnutrition in children under five years old showed 59% of children had normal nutrition and 41% with malnutrition, distributed as follows: 26.12% slight, 12.62% moderate and 2.39% severe. in children between 1-5 years old, malnutrition prevalence was 45%. conclusions. the number of children with malnutrition in tabasco during the study period (1991-1996) has decreased in proportion to the increase of those with normal nutrition. based on the health system activities, the number of health districts with critical malnutrition indicators decreased from 6 to 4.
Susceptibilidad in vitro frente a fluconazol y voriconazol de cepas de Cryptococcus aisladas en Cuba
Illnait Zaragozí,María Teresa; Marie Meis,Jacobus Franciscus Gerardus; Martínez Machín,Gerardo Félix; Curf Breuker,Ilse; Fernández Andreu,Carlos Manuel; Perurena Lancha,Mayda Rosa;
Revista Cubana de Medicina Tropical , 2009,
Abstract: introduction: invasive fungal infections have increased as a result of medical advances in the sphere of transplantation, cancer treatment, autoimmune diseases and aids fundamentally. cryptococcus disease, infrequent before, holds the third place in the incidence of severe mycosis in aids patients and it is also the most lethal. up to the present, there exist few reports on the development of cryptococcus resistance to antifungal products, however, it is foreseen that wide use of fluconazole might encourage the emergence of less susceptible strains. objectives: given the importance of surveillance of antifungal susceptibility and of the evaluation of new therapeutical options, in vitro action of fluconazole and voriconazole on a high number of isolated cryptococcus strains was determined through etest method on clinical and environmental samples. methods: in vitro susceptibility to fluconazole and voriconazole of 159 cryptococcus strains (117 from clinical samples and 42 from environmental sources of central and western regions in cuba) was determined through etest method. results: the studied isolates showed low mic values, mainly susceptibility to voriconazole. ranges, geometric means and modes were 0.031-128, 4.631 y 3 mg/ml for fluconazole and 0.003-8, 0.02 y 0.016 mg/ml for voriconazole, respectively. although mic values were generally higher than those of environmental isolates, there were no statistically significant differences (p= 0.05) among strains according to their origin (clinical/environmental) or to their geographical location. conclusions: this paper points out the importance of continuing this type of study for the detection of resistance to the most used drugs in anticryptococcus disease therapy as well as in the search of new strategies to treat this infection.
Efecto del anticuerpo monoclonal 4B3 en la infección experimental por Cryptococcus neoformans
Illnait-Zaragozí,María Teresa; Gato Armas,René; Martínez Machín,Gerardo Félix; Otero González,Anselmo; Sarracent Pérez,Jorge; Rodríguez Sánchez,Hermis; Fernández Andreu,Carlos Manuel; del Carmen Valdés Hernández,Iliana;
Revista Cubana de Medicina Tropical , 2011,
Abstract: introduction: frequent relapses and high lethality of criptococcosis has encouraged the search for new therapeutic strategies. objectives: to evaluate the effect of the monoclonal antibody 4b3 on the cryptococcal infection in balb/c mice. methods: the kinetics in serum concentration of the studied monoclonal antibody was determined for intraperitoneal administration (500 μg) by quantitative sandwich elisa. in order to assess its protective capability, were administered 500 μg of 4b3 and innoculated 2 x 102.2 cells/ml of cryptococcus neoformans. the survival of mice was recorded and the yeast dissemination to the main target organs was evaluated. macrophages p338.d1 cell lines were used to measure the effect of the monoclonal antibody 4b3 on the phagocytosis and lysis of the microorganism. results: the used dose helped to keep high values (38 μg/m) of 4b3 in serum for at least 46 days. it was found that the monoclonal antibody does not give protection, which makes the microorganism dissemination possible, along with the reduction in the survival of mice. finally, the phagocytosis test showed that 4b3 increased the phagocytic activity of macrophages without any fungicidal effect. conclusions: the monoclonal antibody 4b3 stimulates c. neoformans phagocytosis by macrophages without fungicidal effect, thus favoring yeast dissemination and decreasing the survival of mice due to cryptococcal infection.
Algoritmos y cajas negras: el `programa Matlab en la formación básica en Economía y Finanzas
Fernando Fernández Rodríguez,Julián Andrada Félix
Rect@ , 2000,
Abstract: Los cursos de métodos cuantitativos que se imparten en las distintas facultades de Ciencias Económicas y Empresariales en general, permiten al alumno disponer de una serie de programas informáticos -cajas negras- que le otorgan la capacidad de realizar ciertos estudios interesantes. El alumno sabe qué necesita para resolver un problema cuantitativo y utiliza el programa informático adecuado para tal fin, pero no sabe de qué manera el ordenador resuelve el problema. En este trabajo pretendemos dar un giro respecto a esta metodología, enfatizando en un concepto fundamental en todo el desarrollo cuantitativo: el algoritmo. El enfoque del aprendizaje será la construcción de algoritmos netamente prácticos, de forma que se asimile su concepto a la misma vez que se implemente. Haremos un sencillo recorrido por ciertos problemas fácilmente resolubles a través de algoritmos implementados bajo el entorno de trabajo MATLAB.
Page 1 /353059
Display every page Item


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