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Search Results: 1 - 10 of 631258 matches for " León Gómez Juan Andrés "
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El reactor nuclear colombiano y la agencia de actores no humanos en los estudios sociales de la ciencia
León Gómez Juan Andrés
Revista Colombiana de Sociología , 2004,
Abstract: Basándose en su trabajo de grado de historiador sobre los primeros a os del programa nuclear colombiano, el autor explora la relevancia del concepto de actor no humano originario de las teorías de actores-red. Se muestra cómo el análisis de la consolidación del Instituto de Asuntos Nucleares debe incluir un objeto inanimado, el reactor nuclear, como actor social fundamental. PALABRAS CLAVES. actores no humanos, comunidad científica, energía nuclear
Los inicios del programa nuclear colombiano 1955-1965. Diplomacia y ayuda internacional en la formación de una comunidad científica del Tercer Mundo durante la era del desarrollo
León Gómez Juan Andrés
Revista Colombiana de Sociología , 2004,
Abstract: Este trabajo de grado elaborado entre 2002 y 2003 reconstruye los primeros a os del programa nuclear colombiano. Está basado en fuentes primarias del extinto Instituto de Asuntos Nucleares y del Archivo General de la Nación, analizadas desde el punto de vista de los estudios sociales de la ciencia.
ANáLISIS DEL COMPORTAMIENTO A FATIGA DE UN ACERO AISI 1045 EN UN AMBIENTE DE JUGO DE CA A DE AZúCAR
JAIME ANDRéS GóMEZ,ADOLFO LEóN GóMEZ,JOHN JAIRO CORONADO
Scientia Et Technica , 2005,
Abstract: Se ha estudiado la sinergia de la fatiga en flexión rotatoria y la corrosiónpor jugo de ca a para un acero AISI (SAE) 1045, usando probetas normalizadas de fatiga. Para las pruebas se usó jugo de ca a degradado con pH 4, típico del cuarto molino. Durante la rotación de las probetas se aplicó un flujo continuo de jugo de ca a. Se hicieron comparaciones entre las pruebas normalizadas en seco y las que fueron sometidas al ambiente corrosivo. Estas últimas presentaron una disminución del 11 % en el límite de resistencia a fatiga. Estos resultados son aplicables para las zonas del eje que no están protegidas con lubricante.
Biomonitoring of exposure to environmental pollutants in newborns and their parents in Madrid, Spain (BioMadrid): study design and field work results
Aragonés,Nuria; Pérez-Gómez,Beatriz; Astray,Jenaro; Gil,Elisa; Pérez-Meixeira,Ana María; Paz,Concha de; Iriso,Andrés; Cisneros,Margot; Santos,Amparo de; Arias,Pedro; Sanz,Juan Carlos; Asensio,ángel; Fernández,Mario Antonio; González,María José; León,América de; García-Sagredo,José Miguel; Pollán,Marina; López-Abente,Gonzalo; Frutos García,José; Martínez,Mercedes;
Gaceta Sanitaria , 2008, DOI: 10.1590/S0213-91112008000500014
Abstract: in spain environmental surveillance has mainly relied on measures of selected pollutants in air, water, food and soil. a study was conducted in madrid to assess the feasibility of implementing a surveillance system of exposure among the general population to specific environmental pollutants, using bio-markers. the project was basically focused on the environment surrounding newborns. hence, the study population was made up of 145 triplets of pregnant women at around 8 months' gestation, their partners, and newborns from two areas, representing the two main types of urban environments in the region, i.e., the city of madrid and its outlying metropolitan belt. multiple biologic substrates were collected from each participant in order to assess the most suitable samples for an environmental surveillance system. the selected contaminants represent the main agents to which a population like that of madrid is exposed every day, including certain heavy metals, persistent organic pollutants and polycyclic aromatic hydrocarbons, as well as micronuclei in peripheral blood, a commonly used unspecific index of cytogenetic damage. in addition, passive air samplers were placed around subjects' place of residence. this paper reports in detail on the design and response rates, summarizes field work results, and discusses some lessons learned.
Rectificador monofásico con corrección del factor de potencia usando un convertidor Boost
Hernández Fonseca,Lenny Andrés; Gómez León,Diego Ricardo; Hernández Gómez,Oscar Mauricio;
Tecnura , 2012,
Abstract: this paper shows a mathematical model and corresponding controller design of a 24w dc-dc boost converter used for power factor correction. modeling and simulations are shown (using matlab) together with experimental results.
Rectificador monofásico con corrección del factor de potencia usando un convertidor Boost
Lenny Andrés Hernández Fonseca,Diego Ricardo Gómez León,Oscar Mauricio Hernández Gómez
Tecnura , 2012,
Abstract: This paper shows a mathematical model and corresponding controller design of a 24W DC-DC Boost converter used for power factor correction. Modeling and simulations are shown (using Matlab) together with experimental results.
Relación entre test físicos específicos y rendimiento en gimnastas de elite. (Relationships between specific physical test and performance in elite gymnasts).
Juan Antonio León-Prados,Pedro Tomás Gómez-Píriz,Juan José González-Badillo
RICYDE : Revista Internacional de Ciencias del Deporte , 2011,
Abstract: Resumen Se analizó la relación entre test físicos y rendimiento en Barras Paralelas (BP), Barra Fija (BF) y Caballo con Arcos (CA) en diez gimnastas varones de alto nivel. Se estimó la potencia media relativa al trepar 5m una cuerda (T5), la fuerza relativa al realizar máximas repeticiones de olímpicos desde escuadra (MRO), la flexibilidad activa (A) y pasiva (P) de flexión cadera (2A y 2P), y su abducción desde flexión a 90o (3A y 3P) y el rendimiento competitivo mediante el promedio de las notas finales (NF) en dos competiciones consecutivas. Existen relaciones significativas entre MRO con BP (r = 0,825; p<0.05) y BF (r = 0,678; p<0.05), entre 2A con la NF en BP (r = -0,842) y BF (r = -0,696), entre 3A y la NF en BP (r = 0,629) y entre 3P y la NF en CA (r = 0,652) y BF (r = 0,815). En estos gimnastas se relacionó la capacidad manifestada en test de fuerza y flexibilidad con el rendimiento manifestado en CA, BP y BF.Abstract We analyzed the relationship between physical-test with the performance in Parallel Bar (BP), High Bar (BF) and Pommel Horse (CA) in ten elite gymnasts. The average power expressed on rope climbing 5m (T5) and the relative strength when performing maximum repetitions of L-support pike press to handstand (MRO) was estimated, the active (A) and passive (P) hip flexibility (2A and 2P), and his abduction from 90o hip-flexion (3A and 3P) and the competitive performance by averaging Final Score (NF) in two consecutive competitions. Significant relationships show between MRO with BP (r = 0.825; p <0.05) and BF (r = 0.678; p <0.05), between NF 2A with BP (r = -0.842) and BF (r = -0.696), 3A and NF BP (r = 0.629) and between the NF 3P and CA (r = 0.652) and BF (r = 0.815). In these gymnasts significant relationships were found between the competitive performance in CA, BP and BF and the strength and flexibility physical-test.doi:10.5232/ricyde2011.02206
The Management of Orthostatic Hypotension in Parkinson’s Disease
álvaro Sánchez-Ferro,Julián Benito-León,Juan Carlos Gómez-Esteban
Frontiers in Neurology , 2013, DOI: 10.3389/fneur.2013.00064
Abstract: Orthostatic hypotension (OH) is a common and disabling symptom affecting Parkinson’s disease (PD) patients. We present the effect of the different therapies commonly used to manage PD on this clinical manifestation. For this purpose, we describe the relationship between OH and the current treatments employed in PD, such as L-DOPA, dopaminergic agonists, and continuous dopaminergic stimulation therapies. Additionally, we review the therapeutic measures that could be used to ameliorate OH. There are different approaches to deal with this manifestation, including pharmacological and non-pharmacological treatments, although none of them is specifically aimed for treating OH in PD.
18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Accuracy in the Staging of Non-Small Cell Lung Cancer: Review and Cost-Effectiveness
Nieves Gómez León,Sofía Escalona,Beatriz Bandrés,Cristobal Belda,Daniel Callejo,Juan Antonio Blasco
Radiology Research and Practice , 2014, DOI: 10.1155/2014/135934
Abstract: Aim of the performed clinical study was to compare the accuracy and cost-effectiveness of PET/CT in the staging of non-small cell lung cancer (NSCLC). Material and Methods. Cross-sectional and prospective study including 103 patients with histologically confirmed NSCLC. All patients were examined using PET/CT with intravenous contrast medium. Those with disease stage ≤IIB underwent surgery (). Disease stage was confirmed based on histology results, which were compared with those of PET/CT and positron emission tomography (PET) and computed tomography (CT) separately. 63 patients classified with ≥IIIA disease stage by PET/CT did not undergo surgery. The cost-effectiveness of PET/CT for disease classification was examined using a decision tree analysis. Results. Compared with histology, the accuracy of PET/CT for disease staging has a positive predictive value of 80%, a negative predictive value of 95%, a sensitivity of 94%, and a specificity of 82%. For PET alone, these values are 53%, 66%, 60%, and 50%, whereas for CT alone they are 68%, 86%, 76%, and 72%, respectively. Incremental cost-effectiveness of PET/CT over CT alone was €17,412 quality-adjusted life-year (QALY). Conclusion. In our clinical study, PET/CT using intravenous contrast medium was an accurate and cost-effective method for staging of patients with NSCLC. 1. Introduction Lung cancer is the most common fatal neoplasm in developed countries. Non-small cell lung cancer (NSCLC) is responsible for 80% of all deaths from this neoplasm [1]. Despite all efforts to improve early diagnosis, survival rates remain very low (about 18% at 5 years) [2]. The stage at which NSCLC is detected is the most important of all prognostic factors and the only one that determined treatment options in our study before targeted therapy was administered. The TNM classification of malignant tumors [3] for staging NSCLC is internationally accepted and validated. CT is currently the most commonly used technique in tumor staging. However, results, which are based on normal lymph node size, have limited value. In contrast, PET provides valuable functional information because it can detect metabolically active tumor cells. Over the last 10 years, PET has become an important tool for staging lung cancer, given its high sensitivity in the detection of lymph node involvement and distant metastasis [4] and its current use in presurgical stratification of NSCLC [5]. The combination of CT and PET makes it possible to visualize anatomical and metabolic images together, thus minimising the limitations and maximising the benefits
Construcción de una filogenia molecular para las especies de los géneros Klebsiella y Raoultella basada en los genes ARNr 16S y ARN polimerasa subunidad
Arenas,Nelson Enrique; Gutiérrez, Biol,Andrés Julián; Salazar,Luz Mary; Polanco,Juan Carlos; Gómez,Arley;
Revista Ciencias de la Salud , 2009,
Abstract: the bacteria belonging to raoultella and klebsiella genera are opportunistic pathogens for which there is no consensus about a unique internationally taxonomic system. in this study, we suggest a molecular phylogeny based on 16s (rdna 16s) ribosomal gene and the beta subunit rna polymerase (rpob) encoding gene of klebsiella and raoultella in order to set up evolutionary relationships among these genera. results showed a cluster with similar biochemical and taxonomy characteristics in agreement to genbank description, and a tree bifurcation which confirms the klebsiella and raoultella genera separation. moreover, we verified the polyphyletic character of k. aerogenes by rdna 16s and particularly the clustering for both r. terrigena and k. oxytoca based on rpob gene. the evolutionary relationships recognition was obtained by comparison among the corresponding trees for both genes unraveling significant changes at taxonomic level and stressing the importance of multilocus analysis approach. these studies are useful for tracking the microbial genotype stability over time and space scale; as well as on improving taxonomic annotations (taxa descriptions and genetic subdivisions) and evaluation of genetic diversity in terms of virulence and drug resistance.
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