oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 332 )

2018 ( 575 )

2017 ( 581 )

2016 ( 837 )

Custom range...

Search Results: 1 - 10 of 353066 matches for " Oscar Fernando Sánchez Medina "
All listed articles are free for downloading (OA Articles)
Page 1 /353066
Display every page Item
Evaluación de la producción de bacteriocinas a partir de Lactobacilos y Bifidobacterias
Diana Jaramillo Giraldo,Adelina del Pilar Meléndez,Oscar Fernando Sánchez Medina
Revista Venezolana de Ciencia y Tecnología de Alimentos , 2010,
Abstract: El objetivo de este estudio fue utilizar un grupo de bacterias ácido lácticas aisladas de ensilaje para encontrar, entre ellas, aquella (s) que produzca (n) bacteriocinas con actividad antimicrobiana eficiente frente a microorganismos Gram (+) como Bacillus sphaericus y Bacillus cereus y Gram (-) como Pseudomonas aeruginosa y Pseudomonas putida. Para esto se identificaron las bacterias potenciales y se cultivaron en medios de cultivo enriquecido con fructooligosacáridos para obtener la sustancia antimicrobiana. Se evaluó su actividad antimicrobiana mediante técnicas de difusión en gel y mediante curvas de crecimiento en medio líquido. Las bacterias estudiadas se caracterizaron como Lactobacillus plantarum, Lactobacillus pentosus, Lactobacillus helveticus y una cepa comercial de Bifidobacterium infantis utilizando pruebas bioquímicas y los sistemas multiprueba API 50CH y API 20A. Se encontró que la adición de fructooligosacáridos a la producción de bacteriocinas aumentó la potencia de la sustancia producida al igual que la velocidad de crecimiento en la fase exponencial del microorganismo. La actividad antimicrobiana fue muy prometedora principalmente contra las pseudomonas y esta sustancia puede ser utilizada como posible conservante de alimentos.
Aproximaciones Biológicas y Fisicoquímicas en el tratamiento de contaminantes: un resumen del aporte de la Universidad de los Andes
Jenny Dussan Garzón,Martha Josefina Vives-Florez,Víctor Manuel Sarria,Oscar Fernando Sánchez Medina
Revista de Ingeniería , 2009,
Abstract: Este resumen pretende dar una visión global de los aportes de la Universidad de los Andes en el tratamiento de aguas y suelos con la presencia de compuestos de difícil degradación o tiempo de vida media prolongado, tales como fármacos (Ciclofosfamida), lodos aceitosos y derivados de la industria del petróleo (Tolueno, Xileno, Fenol) derivados de la industria textil, química y pesticidas (Bisphenol A, AMBI, Glifosato, Isoproturon y Metobromuron), usando tecnologías ya sea basadas en procesos biológicos (biorremediación y bioadsorción) o de oxidación avanzada (foto-Fenton). /This summary intends to give a global view of the Universidad de los Andes contributions related to the water and soil treatment in the presence of recalcitrant or long half-life aquatic pollutants such as drugs (Cyclophosphamide), oil sludge and petroleum (Toluene, Xylene and Phenol), textile, chemical (Bisphenol A, AMBI) and pesticides (Glyphosate, Isoproturon, and Metobromuron) industry derived products based on biological (bioremediation and bioadsortion) and advanced oxidation (Photo-Fenton) approaches.
Aproximaciones biológicas y fisicoquímicas en el tratamiento de contaminantes: un resumen del aporte de la Universidad de los Andes
Dussán Garzón,Jenny; Vives-Florez,Martha Josefina; Sarria,Víctor Manuel; Sánchez Medina,Oscar Fernando; Delgado,Luis Fernando; Hernández Sierra,Sebastián; González Barrios,Andrés Fernando;
Revista de Ingeniería , 2009,
Abstract: this summary intends to give a global view of the universidad de los andes contributions related to the water and soil treatment in the presence of recalcitrant or long half-life aquatic pollutants such as drugs (cyclophosphamide), oil sludge and petroleum (toluene, xylene and phenol), textile, chemical (bisphenol a, ambi) and pesticides (glyphosate, isoproturon, and metobromuron) industry derived products based on biological (bioremediation and bioadsortion) and advanced oxidation (photo-fenton) approaches.
Valeriana en el tratamiento a largo plazo del insomnio
Medina Ortiz,Oscar; Sánchez-Mora,Nora; Fraguas Herraez,David; Arango López,Celso;
Revista Colombiana de Psiquiatría , 2008,
Abstract: introduction: valerian has been used for centuries to induce drowsiness due to its anxiolytic properties. it was fi rst described being used in ancient cultures, i.e., greece and china. nowadays, even though it is not officially approved by the us food and drug administration agency (fda) as a treatment for insomnia, it is widely used in different latitudes for such a purpose. objective: to carry out an extensive review in order to establish the levels of effectiveness of valerian in the long term treatment of patients suffering from sleeplessness and consider it an alternative to the use of benzodiazepines and benzodiazepinic agonists. results: there are very few controlled studies on the effects of valerian. nonetheless, the available data might indicate that the use of valerian helps to restructure sleep architecture after several weeks of treatment and helps to improve sleep quality. there are also papers suggesting that valerian plays a key role in diminishing stress and anxiety in cases where these conditions disturb normal sleep patterns and is useful in discontinuing long treatments based on benzodiazepines. conclusions: the key advantage of valerian is its capability to reduce the slow wave sleep latency and increase its percentage without causing relevant secondary effects or dependence. still, we do not have sufficient data from long term controlled studies in order to support conclusive results.
Valeriana en el tratamiento a largo plazo del insomnio Use of Valerian in the Long-Term Treatment of Insomnia
Oscar Medina Ortiz,Nora Sánchez-Mora,David Fraguas Herraez,Celso Arango López
Revista Colombiana de Psiquiatría , 2008,
Abstract: Introducción: La valeriana se ha utilizado desde la antigua Grecia y China para inducir el sue o, debido a sus propiedades ansiolíticas. Hoy en día, aun cuando no es un producto aprobado por la Agencia de Administración de Drogas y Alimentos de Estados Unidos (FDA) para el tratamiento del insomnio, se utiliza en diferentes países con esta finalidad. Objetivo: Llevar a cabo una revisión que permita determinar la eficacia de la valeriana en el tratamiento a largo plazo del insomnio y considerarla una alternativa terapéutica posible a las benzodiazepinas y los agonistas benzodiazepínicos. Resultados: Son pocos los estudios controlados realizados con valeriana; no obstante, los resultados disponibles sugieren que su empleo facilita la reestructuración de la arquitectura del sue o después de varias semanas de tratamiento y consigue así mejorar su calidad. También hay indicios que se alan que desempe a un papel importante en la disminución del estrés y la ansiedad en aquellos pacientes donde esta condición interfi ere con el inicio y mantenimiento del sue o, así como en el tratamiento coadyuvante en la discontinuación del uso prolongado de benzodiazepinas. Conclusiones: El principal punto a favor de la valeriana es su capacidad para disminuir la latencia del sue o de ondas lentas y aumentar su porcentaje, sin provocar efectos secundarios de importancia ni dependencia; sin embargo, aún no se dispone de suficientes estudios controlados a largo plazo que permitan establecer conclusiones definitivas. Introduction: Valerian has been used for centuries to induce drowsiness due to its anxiolytic properties. It was fi rst described being used in ancient cultures, i.e., Greece and China. Nowadays, even though it is not officially approved by the US Food and Drug Administration Agency (FDA) as a treatment for insomnia, it is widely used in different latitudes for such a purpose. Objective: To carry out an extensive review in order to establish the levels of effectiveness of valerian in the long term treatment of patients suffering from sleeplessness and consider it an alternative to the use of benzodiazepines and benzodiazepinic agonists. Results: There are very few controlled studies on the effects of valerian. Nonetheless, the available data might indicate that the use of valerian helps to restructure sleep architecture after several weeks of treatment and helps to improve sleep quality. There are also papers suggesting that valerian plays a key role in diminishing stress and anxiety in cases where these conditions disturb normal sleep patterns and is useful in disco
Response of rice cultivation to biofertilizers in Campeche, Mexico  [PDF]
Fermín Orona-Castro, Mónica Guadalupe Lozano-Contreras, Martín Tucuch-Cauich, Oscar A. Grageda-Cabrera, Juan Medina-Mendez, Arturo Díaz-Franco, Esaú Ruiz-Sánchez, Jesús Soto-Rocha
Agricultural Sciences (AS) , 2013, DOI: 10.4236/as.2013.412097
Abstract: The activity of various biofertilizers on rice production (Sabanero A95) was evaluated in Palizada, Campeche, Mexico, in the wet season of 2009 (year one) and 2011 (year two). On year one, arbuscular mycorrhiza INIFAP? (Rhizophagus intraradices), Azospirillum brasilense plus arbuscular micorrhiza Rhizophagus sp., and chemical fertilizer (92, -92, -60 kg·ha-1) were evaluated, while on year two marine algae extracts, a consortium of growth promoting bacteria (Pseudomonas spp.) and a control (not fertilized) were evaluated. The results showed that there were no significant differences on grain yield among treatments during the year one. The average grain yield was 2,800 kg·ha-1. As for the year two,
Evaluación de la actividad desulfurizadora de aislados nativos de Pseudomonas spp. en presencia de hidrocarburo Desulfurization activity evaluation of native strains of Pseudomonas spp. in the presence of hydrocarbon
Alméciga-Díaz Carlos Javier,Sánchez Medina óscar Fernando,Silva Gómez Edelberto
Revista Colombiana de Biotecnología , 2005,
Abstract: El principal inconveniente en la combustión de los hidrocarburos es la conversión del azufre y el nitrógeno a sus respectivos óxidos, los cuales participan en la formación de lluvia acida y deterioran el medio ambiente e infraestructuras. La remoción de azufre a partir de compuestos órgano-azufrados mediante el uso de microorganismos ha surgido como una alternativa frente al proceso catalítico de hidrodesulfurización (HDS). En el presente trabajo se evaluó la actividad desulfurizadora de veintitrés aislados nativos de Pseudomonas spp. sobre dibenzotiofeno (DBT), usando un sistema de fermentación con igual proporción de fase acuosa y orgánica (n-hexano) en presencia de oleato de etanolamina. Los aislados 02,05 y 06 conservaron su viabilidad en este medio y presentaron una remoción de azufre entre 6,0 y 9,4%, generando los metabolitos DBT-sulfona, DBT-sulfóxido, 2-hidroxibifenilo (2-HBP) y sulfato presentes en la ruta metabólica 4S. Con estos aislados se evaluó la actividad desulfurizadora sobre keroseno y se observó una remoción de azufre entre 19,9 y 62,6% y una disminución del poder calorífico entre 0,45 y 5,55%. Palabras clave: dibenzotiofeno, desulfurización, Pseudomonas spp., keroseno. The main difficulty with fossil fuel combustión lies in sulphur and nitrogen becoming converted to their respective oxides, forming part of the acid rain which deteriorates the environment and infrastructure. Removing sulphur from organo-sulfur compounds by using micro-organisms has become an alternative to hydrodesulphurisation (HDS). Twenty-three Pseudomonas spp. native strains' desulphurisation activity on dibenzothiophene (DBT) was evaluated by using a fermentation system having equal proportions of aqueous and organic (n-hexane) phases in the presence of ethanolamine oléate. The 02, 05 and 06 strains maintained their viability in this médium, presenting 6,0% to 9,4% sulphur removal, producing DBT-sulphone, DBT-sulphoxide, 2-hydroxybiphenyl (2-HBP) metabolites and sulphate belonging to the 4S pathway. These native strains' desulphurisation activity was evaluated on kerosene, presenting 19,9% to 62,2% sulphur removal having 0,45% to 5,55% calorific power loss. Key words: dibenzothiophene, desulphurisation, Pseudomonas spp. kerosene.
ESTIMACIóN DE VARIABLES DE OPERACIóN DE UN BIORREACTOR CON CéLULAS DE Azadirachta indica A. Juss
Mu?oz Cruz,Walter; Vanegas Monterrosa,Oscar Alejandro; Guzmán Rosas,Andrés Alberto; Capataz Tafur,Jacqueline; Hoyos Sánchez,Rodrigo Alberto; Orozco Sánchez,Fernando;
Revista Facultad Nacional de Agronomía, Medellín , 2006,
Abstract: operation variables of a stirred tank bioreactor were studied in order to culture cell suspension of azadirachta indica a. juss carboximethylcelulose, cmc 0,7 % w/v, was used to estimate the coefficient of oxygen transfer, kla, between 120 - 400 rpm and 0,05 - 0,6 vvm, obtaining values of 0,5 - 8,0 h-1. the kla for suspension cultures of a. indica in erlenmeyers was 0,6 - 1,2 h-1. based upon the previous results, the operation conditions of the bioreactor were defined and cell growth of a. indica was evaluated at 200 rpm and 0,2 vvm of air, reaching 9,2 g dry cell/l. celular growth was not limited by dissolved oxygen. the sizes of cell agglomerates magnetically stirred in erlemeyers with bafles and in the bioreactor were similar, but smaller that those obtained in erlenmeyers with orbital agitation. the present study establishes parameters for operation of bioreactors with a. indica and confirms that cmc can be used to estimate operational variables in bioreactors.
Mejoramiento de la poscosecha del cacao a partir del roadmapping
Sánchez Vargas,Adriana del Pilar; Castellanos Domínguez,Oscar Fernando; Domínguez Martínez,Karen Patricia;
Ingeniería e Investigación , 2008,
Abstract: this article presents the methodology and results which led to preparing post-harvesting technological development strategies for cocoa management which emerged from identifying problems such as deficient cocoa quality and insufficient fermentation of the beans according to international market requirements as shown in the poor technological development in colombia ?s main cocoa producing areas. this situation led to using a technological management tool such as roadmapping orientated towards formulating strategies for the technological development of cocoa postharvest management. the methodological process so implemented involved experts? ongoing participation in enriching and validating results whilst four phases were implemented: performance analysis, gap analysing, structuring roadmapping and formulating cocoa postharvest technological development strategies. the results obtained in this investigation were directed towards improving colombian cocoa sector competitiveness in internal and external markets.
Demoras en el diagnóstico y tratamiento de mujeres con cáncer de mama en Bogotá, Colombia
Pi?eros,Marion; Sánchez,Ricardo; Perry,Fernando; García,Oscar Armando; Ocampo,Rocío; Cendales,Ricardo;
Salud Pública de México , 2011, DOI: 10.1590/S0036-36342011000600003
Abstract: objective: establish provider delay for breast cancer and related factors. material and methods: 1 106 women with breast cancer were approached in health care institutions of bogota, colombia. according to the history of first consultation, we established diagnostic and treatment incidence rates, which were compared for different variables. a cox hazard model was established. results: median time from first consultation to diagnosis and start of treatment were 91 days (ci95%:82-97 days) and 137 days (ci95%:127-147 days) respectively. diagnosis and treatment were faster in women with higher educational level, affiliated to the "special" social security, with better socioeconomic conditions and in screening-detected breast cancers. conclusion: provider delay is excessive. there are clear inequities in access to services and a need of reducing the waiting times for women with a suspicion of breast cancer.
Page 1 /353066
Display every page Item


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