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Sample records for celulas progenitoras derivadas

  1. O grau de melhora na função das células progenitoras endoteliais derivadas da medula óssea é dependente do volume de treinamento físico aeróbio

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    Tiago Fernandes

    2013-08-01

    Full Text Available INTRODUÇÃO: A angiogênese muscular esquelética induzida pelo treinamento físico aeróbio (TF é determinante na melhora da capacidade aeróbia. Entre os fatores envolvidos, as células progenitoras endoteliais (CPE derivadas da medula óssea são descritas por promoverem o reparo vascular e a angiogênese. Embora o papel do TF sobre os parâmetros das CPE tenha sido investigado, pouco se conhece sobre os efeitos de diferentes volumes de TF sobre a função das CPE da medula óssea, alterações metabólicas e capilarização muscular. OBJETIVO: Testar a hipótese de que o TF melhore a função das CPE da medula óssea, acompanhada por maior capilarização e capacidade oxidativa muscular dependentes do aumento de volume de TF. MÉTODOS: Vinte e uma ratas Wistar foram divididas em três grupos: sedentário controle (SC, treinado protocolo 1 (P1, treinado protocolo 2 (P2. P1: o treinamento de natação consistiu de 60 min, 1x/dia, cinco dias/semana/10 semanas, com 5% de sobrecarga corporal. P2: o mesmo de P1 até a oitava semana, na nona semana os animais treinaram 2x/dia e na 10ª semana 3x/dia. RESULTADOS: O TF promoveu bradicardia de repouso, aumento da tolerância ao esforço, do consumo de oxigênio de pico e da atividade da enzima citrato sintase muscular no grupo P1, sendo estas adaptações mais exacerbadas no grupo P2, indicando que a condição aeróbia foi mais proeminente com este TF. O TF melhorou a função das CPE da medula óssea em P1, sendo ainda maior esta resposta no grupo P2. Em paralelo, observa-se também um aumento no número de capilares dependentes do volume de TF. CONCLUSÃO: Estes resultados sugerem que a medula óssea como o principal reservatório de CPE é influenciada por diferentes volumes de TF, sendo possivelmente responsável pelo maior rendimento físico observado mediante uma maior mobilização endógena de CPE, participantes ativas no processo de angiogênese muscular induzido pelo TF.

  2. Tratamento da Osteonecrose da Cabeça Femoral com celulas progenitoras autólogas em anemia falciforme Femoral Head Necrosis treatment with autologous stem cells in sickle cell disease

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    Gildásio Cerqueira Daltro

    2008-01-01

    Full Text Available OBJETIVO: Avaliação da segurança e eficácia do uso de células progenitoras autólogas da medula óssea (CMMO no tratamento da Osteonecrose da Cabeça Femoral (OCF de pacientes portadores de anemia falciforme. MÉTODOS: Foram estudados 8 pacientes portadores de anemia falciforme, com OCF nos estágios I e II (classificação de Ficat e Arlet. As CMMO retiradas da crista ilíaca posterior foram concentradas e reinfundidas na área central da osteonecrose. Os principais parâmetros avaliados foram segurança, sintomas clínicos e progressão da doença, através da avaliação clínica (Harris Hip Score e radiológica. RESULTADOS: A maior parte dos pacientes (7 em 8 referiu melhora dos sintomas após o tratamento. Não houve complicações durante o procedimento anestésico e cirúrgico. A medida do escore (Harris Hip Score no pré-operatório foi 78,5 +/- 6,2 pontos, com aumento significativo destes valores no pós-operatório (98,3 +/- 2,5 pontos (pPURPOSE: To assess the efficacy and safety of autologous bone-marrow mononuclear cells (BMMC implantation in necrotic lesions of the femoral head in patients with sickle cell disease. METHODS: We studied eight patients with stage-I or -II femoral head osteonecrosis according to the system by Ficat and Arlet. BMMCs were harvested and re-infused into the necrotic zone. The primary endpoints studied were safety, clinical symptoms and disease progression, these being assessed according to the Harris hip score (HHS and to X-ray studies. RESULTS: After eight months, seven of the eight patients reported improvement from symptoms. There were no complications during anesthetic and surgery procedures. There was a significant postoperative increase in the HHS (98.3 +/- 2.5 points compared to preoperative HHS (78.5 +/- 6.2 points (p< 0.001. X-ray evaluation and cell parameters were found to be favorable. CONCLUSION: The autologous bone-marrow mononuclear cells implantation seems to be a safe and effective

  3. El desarrollo del esquema de derivada

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    Sánchez-Matamoros García, Gloria; García Blanco, Mercedes; Llinares, Salvador

    2006-01-01

    La investigación tiene como objetivo estudiar el desarrollo de la comprensión del concepto de derivada en el nivel de bachillerato (16-18 años) y primer año de la universidad. El marco teórico utilizado fue el desarrollo de un esquema a través de tres fases: Intra, Inter, Trans (Piaget y García, 1983, 1989). El análisis de las respuestas de los estudiantes a diferentes problemas de derivadas nos permitió asignarles un nivel de desarrollo del esquema de derivada. Los resultados obtenidos indic...

  4. Avaliação da integridade das células-tronco mesenquimais derivadas do tecido adiposo humano após o bioprocesso de criopreservação

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    Irioda, Ana Carolina

    2012-01-01

    Resumo: As celulas-tronco de origem adulta surgem como promessa terapeutica na medicina regenerativa podendo ser encontradas em diversos tecidos como o adiposo. Com as perspectivas da criacao de um banco de celula-tronco para pesquisa e posterior uso terapeutico, o estudo da criopreservacao dessas celulas urge, a fim de garantir que essas celulas apos o descongelamento permanecam viaveis e funcionais. Objetivos: Comparar as celulas-tronco do tecido adiposo antes da criopreservacao e apos o se...

  5. Células progenitoras endoteliais circulantes em crianças e adolescentes obesos

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    António Pires; Paula Martins; Artur Paiva; Ana Margarida Pereira; Margarida Marques; Eduardo Castela; Cristina Sena; Raquel Seiça

    2015-01-01

    Resumo Objetivo Investigar a relação entre os números de células progenitoras endoteliais circulantes e a ativação endotelial em uma população pediátrica com obesidade. Métodos Estudo observacional e transversal, que incluiu 120 crianças e adolescentes com obesidade primária de ambos de sexos, entre seis e 17 anos, recrutados de nossa Clínica de Riscos Cardiovasculares. O grupo de controle contou com 41 crianças e adolescentes com índice de massa corporal normal. As variáveis analisadas for...

  6. Células progenitoras endoteliais circulantes em crianças e adolescentes obesos

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    António Pires

    2015-12-01

    Full Text Available Resumo Objetivo Investigar a relação entre os números de células progenitoras endoteliais circulantes e a ativação endotelial em uma população pediátrica com obesidade. Métodos Estudo observacional e transversal, que incluiu 120 crianças e adolescentes com obesidade primária de ambos de sexos, entre seis e 17 anos, recrutados de nossa Clínica de Riscos Cardiovasculares. O grupo de controle contou com 41 crianças e adolescentes com índice de massa corporal normal. As variáveis analisadas foram: idade, sexo, índice de massa corporal, pressão arterial sistólica e diastólica, proteína C reativa de alta sensibilidade, perfil lipídico, leptina, adiponectina, resistência à insulina para avaliação do modelo de homeostase, proteína quimiotática de monócitos-1, E-seleticna, dimetilarginina assimétrica e números de células endoteliais progenitoras circulantes. Resultados A resistência à insulina foi correlacionada à dimetilarginina assimétrica (p = 0,340; p = 0,003, que foi diretamente correlacionada, porém de forma muita amena, à E-seleticna (ρ = 0,252; p = 0,046. Não constatamos que a proteína C reativa de alta sensibilidade estivesse correlacionada a marcadores de ativação endotelial. A pressão arterial sistólica foi diretamente correlacionada ao índice de massa corporal ρ = 0,471; p < 0,001 e à resistência à insulina para avaliação do modelo de homeostase (ρ = 0,230; p = 0,012 e inversamente correlacionada à adiponectina (ρ = −0,331; p < 0,001 e à lipoproteína de alta densidade-colesterol ρ = −0,319; p < 0,001. Os números de células progenitoras endoteliais circulantes foram diretamente correlacionados, porém de forma muito amena, ao índice de massa corporal (r = 0,211; p = 0,016, à leptina (ρ = 0,245; p = 0,006, aos níveis de triglicerídeos (r = 0,241; p = 0,031 e à E-seleticna ρ = 0,297; p = 0,004. Conclusão Os números de células progenitoras endoteliais circulantes s

  7. Células progenitoras pluripotenciales: características y compartimientos especializados de residencia

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    Siham Salmen

    2013-12-01

    Full Text Available Las células progenitoras son una población diversa caracterizada por mediar el recambio y renovación constante de los diferentes tejidos del cuerpo, de hecho han sido aisladas de diferentes compartimientos tisulares llamados nichos. Su estudio ha permitido entender su comportamiento e interrelación con los elementos de su entorno y eventos que controlan su capacidad de autorenovación, diferenciación y quiescencia; despertando el interés de muchos grupos de investigación a fin de proponer nuevas estrategias terapéuticas para el manejo de múltiples patologías crónicas. Pluripotent stem cells: characteristics and specialized compartments of residence Abstract Stem cells are a diverse population characterized to promote renewal of the different tissues; in fact they have been isolated from different compartments in the body named niches. Their study has allowed understanding their behavior and interaction with the elements of their environment and events that control self-renewal capacity, differentiation and quiescence, taken the interest of several research groups to propose new therapeutic strategies to management of chronic diseases.

  8. Aplasia pura de serie roja post-trasplante alogeneico de células progenitoras hematopoyeticas ABO incompatible

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    E. Bulliorsky; C. Shanley; G. Stemmelin; J. Ceresetto; O. Rabinovich

    2002-01-01

    El trasplante alogeneico de células progenitoras hematopoyéticas (TCPH) con incompatibilidad ABO entre el donante y el receptor puede en ocasiones asociarse a trastornos en la progenie eritroide desarrollada a partir de la médula ósea trasplantada, caracterizado por un funcionamiento tardío, inadecuado e incompleto de la misma. En este contexto, la aplasia pura de serie roja es la complicación más severa. Se han intentado tratamientos para la aplasia pura de serie roja post-TCPH con eritropoy...

  9. Aplasia pura de serie roja post-trasplante alogeneico de células progenitoras hematopoyeticas ABO incompatible

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    E. Bulliorsky

    2002-12-01

    Full Text Available El trasplante alogeneico de células progenitoras hematopoyéticas (TCPH con incompatibilidad ABO entre el donante y el receptor puede en ocasiones asociarse a trastornos en la progenie eritroide desarrollada a partir de la médula ósea trasplantada, caracterizado por un funcionamiento tardío, inadecuado e incompleto de la misma. En este contexto, la aplasia pura de serie roja es la complicación más severa. Se han intentado tratamientos para la aplasia pura de serie roja post-TCPH con eritropoyetina o plasmaféresis, con relativo éxito. Algunos autores han informado también la utilización de globulina antilinfocitaria, asumiendo que dicha aplasia selectiva de la serie roja en la médula ósea trasplantada es mediada por un mecanismo inmune. En este trabajo se describe un paciente portador de una leucemia aguda en quien se realizó un TCPH alogeneico (ABO incompatible con su donante. Teniendo niveles bajos de aglutininas contra el grupo sanguíneo de la donante, desarrolló una aplasia pura de serie roja post - TCPH. La misma no mejoró con tratamiento con eritropoyetina o con un refuerzo de progenitores hematopoyéticos de sangre periférica de la misma donante (boost, resolviéndose totalmente luego de un tratamiento exitoso con globulina antilinfocitaria de origen equino.

  10. Trasplante de células progenitoras hematopoyéticas en enfermedades autoinmunes Hematopoietic stem cell transplantation in autoimmune diseases

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    Flavio Albarracín

    2008-04-01

    Full Text Available El trasplante de células progenitoras hematopoyéticas, células con capacidad de autorrenovación y reconstitución de todos los tipos de células sanguíneas, se utiliza en el tratamiento de numerosas enfermedades potencialmente letales incluyendo leucemias y linfomas. Hoy en día es posible además aplicarlo en el tratamiento de enfermedades autoinmunes graves, como esclerosis múltiple, lupus eritematoso sistémico o esclerosis sistémica, resistentes a la terapia convencional. Estudios en modelos animales nos demuestran que la transferencia de células progenitoras hematopoyéticas podría revertir el proceso de autoinmunidad, un fenómeno que puede explicarse mediante diferentes mecanismos. El resultado de los estudios clínicos que se están llevando a cabo, así como también estudios en pacientes y modelos animales, ayudarán a determinar el rol que el transplante de células progenitoras hematopoyéticas puede jugar en el tratamiento de enfermedades autoinmunes.Transplantation of hematopoietic stem cells, which are capable of self renewal and reconstitution of all types of blood cells, can be a treatment for numerous potential lethal diseases, including leukemias and lymphomas. It may now be applicable for the treatment of severe autoimmune diseases, such as therapy-resistant multiple sclerosis, lupus and systemic sclerosis. Studies in animal models show that the transfer of hematopoietic stem cells can reverse autoimmunity. The outcome of ongoing clinical trials, as well as of studies in patients and animal models, will help to determine the role that stem-cell transplantation can play in the treatment of autoimmune diseases.

  11. Aplasia pura de serie roja post-trasplante alogeneico de células progenitoras hematopoyeticas ABO incompatible Pure red cell aplasia after ABO incompatible bone marrow transplantation

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    E. Bulliorsky; C. Shanley; G. Stemmelin; J. Ceresetto; O. Rabinovich

    2002-01-01

    El trasplante alogeneico de células progenitoras hematopoyéticas (TCPH) con incompatibilidad ABO entre el donante y el receptor puede en ocasiones asociarse a trastornos en la progenie eritroide desarrollada a partir de la médula ósea trasplantada, caracterizado por un funcionamiento tardío, inadecuado e incompleto de la misma. En este contexto, la aplasia pura de serie roja es la complicación más severa. Se han intentado tratamientos para la aplasia pura de serie roja post-TCPH con eritropoy...

  12. Evaluación de los niveles plasmáticos de células progenitoras en pacientes con enfermedad coronaria crónica

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    Juan Gagliardi

    2007-01-01

    Full Text Available IntroducciónEl ejercicio físico es útil para los pacientes con enfermedad coronaria y es un estímulo para el desarrollo de circulación colateral. Ésta podría estar determinada por un aumento en la producción y circulación de células progenitoras.ObjetivoEvaluar el efecto del ejercicio físico programado sobre la producción y el número circulante de células progenitoras en pacientes coronarios crónicos estables.Material y métodosEstudio prospectivo, controlado, aleatorizado y abierto con la inclusión de 18 pacientes (8 en grupo ejercicio y 10 en grupo control con enfermedad coronaria estable, < 75 años, que no hubieran participado en grupos de ejercicio programado en los últimos 3 meses. La determinación de las células progenitoras se realizó por citometría de flujo utilizando marcaciones con anticuerpos monoclonales CD45-FITC, CD34-FITC y CD133/1-PE.ResultadosEn el grupo control, el nivel de CD45 no tuvo variación significativa (0,724 ± 0,256 versus 0,765 ± 0,216 [media ± EE cada 100.000 eventos], mientras que en el grupo ejercicio el nivel de CD45(+/CD133(+ se incrementó de 0,497 ± 0,161 a 2,265 ± 1,003 luego de un mes de actividad física programada sin alcanzar significación estadística.Al analizar los niveles de CD34 se observó que en el grupo control se incrementaron de 0,196 ± 0,086 a 0,235 ± 0,063 (p = NS. En el grupo ejercicio, la variación fue mucho mayor: 0,220 ± 0,078 a 0,844 ± 0,172 (p = 0,0046; p = 0,0092 versus el grupo control. ConclusiónEl ejercicio físico programado en pacientes coronarios promueve un incremento de las células progenitoras circulantes. Su estímulo persistente podría ser la base para un mayor desarrollo de circulación colateral.

  13. SELECCIÓN DE LÍNEAS DE PIMIENTO (Capsicum annuum L. PARA SER UTILIZADAS COMO PROGENITORAS EN LOS PROGRAMAS DE OBTENCIÓN DE HÍBRIDOS

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    Yaritza Rodríguez

    2005-01-01

    Full Text Available Las enfermedades virales constituyen el principal obstáculo para el desarrollo del pimiento en el mundo. En Cuba, lo afectan principalmente el virus del mosaico del tabaco (TMV, virus Y de la papa (PVY, virus del grabado del tabaco (TEV, virus del moteado de las venas del pimiento (PVMV y virus del mosaico del pepino (CMV. El control genético aparece como la vía más eficiente. Para la construcción simultánea de resistencia a virus y adaptación climática en el pimiento, se realizó un estudio de correlaciones fenotípicas que optimizan la selección, lo que permitió el logro, por primera vez en Cuba, de líneas multirresistentes y adaptadas al trópico, empleadas como progenitoras en los primeros híbridos F1 cubanos. Como resultado se obtuvieron siete líneas multirresistentes y adaptadas como progenitoras de híbridos F1 de pimiento: Cu 17 (PVY y TMV; Cu 26 y Cu 28 (PVMV y TMV; Cu 29, Cu 32 y Cu 33 (TEV y TMV y Cu 103 (CMV y TMV.

  14. Algunos indicadores del desarrollo del esquema de derivada de una función

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    Sánchez-Matamoros García, Gloria; García Blanco, Mercedes; Llinares Ciscar, Salvador

    2013-01-01

    El objetivo de esta investigación es caracterizar algunos indicadores del desarrollo del esquema de derivada en estudiantes de pos-secundaria. Usamos los niveles intra, inter y trans del desarrollo de un esquema propuestos por Piaget y García para caracterizar el uso flexible que los estudiantes hacen de la equivalencia lógica entre diferentes elementos matemáticos cuando resuelven un problema, como un indicador del desarrollo del esquema de derivada. Este indicador ayuda a explicar la transi...

  15. Un método para el cálculo de derivadas segundas

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    Scolnik, Hugo Daniel; Gambini, María Juliana

    2000-01-01

    En este trabajo consideramos el problema de calcular aproximaciones para la derivada segunda de funciones de varias variables usando la técnica de diferencias finitas. Mostramos de donde surgen las diferentes fórmulas y calculamos los errores que se cometen con esas aproximaciones en función del incremento h, para derivadas primeras y segundas. Basándonos en estas observaciones describimos dos métodos, el de Gill y Murray y el de diferencias de gradientes. También introducimos un nuevo algori...

  16. PRODUCCIÓN DE SEMILLA DE LÍNEAS PROGENITORAS DE MAÍZ: DENSIDAD DE POBLACIÓN E INTERACCIÓN

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    Juan Virgen-Vargas

    2014-01-01

    Full Text Available Producción de semilla de líneas progenitoras de maíz: densidad de población e interacción. El objetivo del presente estudio fue determinar los efectos de la localidad y la densidad de población en la producción de semilla de líneas progenitoras de híbridos de maíz de Valles Altos de México. En el período de 2006 a 2008, en Coatlinchán, Texcoco, Estado de México (2250 msnm se sembraron 16 líneas progenitoras de los híbridos: H-40, H-48, H-50, H-52, H-64E, H-66, H-68E, H-70, H-72E, H-74E, H-76E y H-78E en dos densidades de población 82 500 y 62 500 plantas/ha en un diseño de Bloques Completos al Azar con tres repeticiones. Hubo diferencias significativas (p≤0,05 entre líneas, densidad de población y años. Las líneas promediaron entre 73 y 78, y entre 82 y 83 días para inicio y floración media masculina y femenina, respectivamente. El rendimiento varió entre 7744 y 1484 kg/ha, con 86 y 14% de semilla grande y peso hectolítrico entre 70 y 57 kg/hl. Con 82 500 plantas/ ha se incrementó en 13% el rendimiento de semilla y disminuyó 2,5% el peso de mil semillas, en comparación con 62 500 plantas/ha. Entre años, el inicio y floración media masculina y femenina varió entre tres y cuatro días; en el 2008 el rendimiento y el peso hectolítrico fueron mayores (4427 kg/ ha y 71,75 kg/hl, en 2007 hubo 46,93 y 29,59% más semilla grande que en el 2006 y 2008; mientras que en el 2006 el rendimiento fue 25,30% menor al promedio del 2007-2008. Para determinar cuándo y dónde producir semilla híbrida es indispensable conocer la línea, la localidad de producción y la interacción del genotipo con el ambiente.

  17. Algunos resultados de estabilidad de ecuaciones en derivadas parciales estocásticas con retardos

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    Caraballo Garrido, Tomás

    1988-01-01

    "En esta memoria presentamos una contribución al estudio de la estabilidad en la Ecuaciones en Derivadas Parciales Estocásticas (E.D.P.E) con retardo.Hemos estructurado nuestro trabajo en cuatro capítulos. En el primero se encuentran aquellos resultados s

  18. Fases en la tematización del esquema de la derivada: comprensión en alumnos universitarios

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    Fuentealba, C; E. Badillo; Sánchez-Matamoros García, Gloria

    2015-01-01

    El estudio que presentamos es parte de una investigación más extensa que aborda la comprensión del concepto de derivada en estudiantes universitarios con instrucción previa en cálculo diferencial. En particular, nos centramos en el análisis de la tematización del esquema de la derivada. Para ello se utilizan los niveles de comprensión de un esquema intra-inter-trans (propuestos por Piaget y García) ajustados al concepto de derivada en términos de elementos matemáticos, relaciones lógicas y mo...

  19. Producción de semilla de líneas progenitoras de maíz: densidad de población e interacción.

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    Juan Virgen-Vargas

    2014-07-01

    Full Text Available El objetivo del presente estudio fue determinar los efectos de la localidad y la densidad de población en la producción de semilla de líneas progenitoras de híbridos de maíz de Valles Altos de México. En el período de 2006 a 2008, en Coatlinchán, Texcoco, Estado de México (2250 msnm se sembraron 16 líneas progenitoras de los híbridos: H-40, H-48, H-50, H-52, H-64E, H-66, H-68E, H-70, H-72E, H-74E, H-76E y H-78E en dos densidades de población 82 500 y 62 500 plantas/ha en un diseño de Bloques Completos al Azar con tres repeticiones. Hubo diferencias significativas (p≤0,05 entre líneas, densidad de población y años. Las líneas promediaron entre 73 y 78, y entre 82 y 83 días para inicio y floración media masculina y femenina, respectivamente. El rendimiento varió entre 7744 y 1484 kg/ha, con 86 y 14% de semilla grande y peso hectolítrico entre 70 y 57 kg/hl. Con 82 500 plantas/ha se incrementó en 13% el rendimiento de semilla y disminuyó 2,5% el peso de mil semillas, en comparación con 62 500 plantas/ha. Entre años, el inicio y floración media masculina y femenina varió entre tres y cuatro días; en el 2008 el rendimiento y el peso hectolítrico fueron mayores (4427 kg/ha y 71,75 kg/hl, en 2007 hubo 46,93 y 29,59% más semilla grande que en el 2006 y 2008; mientras que en el 2006 el rendimiento fue 25,30% menor al promedio del 2007-2008. Para determinar cuándo y dónde producir semilla híbrida es indispensable conocer la línea, la localidad de producción y la interacción del genotipo con el ambiente.

  20. Resolución Numérica de sistemas acoplados de ecuaciones en derivadas parciales

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    L. Jódar; Legua, Matilde

    1991-01-01

    En este artículo se presenta un niétodo para la obtención de soluciones numéricas precisas de problemas mixtos para sistemas acoplados de ecuaciones en derivadas parciales. Dichas soluciones aproximadas están expresadas en forma analítica finita y computable, obtenidas mediante la truncación de una serie infinita y la substitución de ciertas exponenciales de matrices mediante aproximantes de Padé. Dado un intervalo de interés y un error admisible E, indicamos un procedimiento para la obtenció...

  1. Algunas dificultades en la resolución de problemas con derivadas

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    Londoño, Noelia; Kakes, Alibeit; Decena, Victoria

    2013-01-01

    A través de este documento se dan a conocer los resultados parciales encontrados en un estudio realizado a estudiantes de primer año de licenciatura, siendo el objeto central indagar acerca de las dificultades que presentan en la resolución de problemas en el área de las matemáticas, los que se podrían resolver usando la derivada. Para esta parte de la investigación se diseñó y aplicó un diagnóstico el cual contenía cuatro problemas referidos a: graficación de funciones, extremos de funciones...

  2. Métodos computacionales en los sistemas de ecuaciones en derivadas parciales

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    Moreno Frías, María Angeles

    2000-01-01

    "La memoria tiene dos partes: La primera está dedicada a la comparación entre los métodos clásicos de Riquier-Janet (para el estudio de los sistemas de ecuaciones en derivadas parciales) y los métodos modernos del álgebra computacional. Los resultados de Janet tienen la siguiente interpretación homológica: Los sistemas de Janet (y Riquier y otros) tienen grupos Ext(de orden superior a 1, a valores en el anillo de gérmenes de funciones holomorfas) nulos. En la segunda parte se estudian otros m...

  3. Evaluación del cultivo de celulas madre mesenquimales y celulas del epitelio pigmentario de la retina en un modelo organotípico de neurorretina de cerdo

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    Rodríguez Crespo, David

    2014-01-01

    A partir de los objetivos planteados en este trabajo y tras la discusión de los resultados obtenidos se ha llegado a las siguientes conclusiones: 1- Se ha conseguido poner a punto la metodología necesaria para establecer un cultivo organotípico de neurorretina con la presencia de epitelio en forma de cultivo celular, en el que se han podido cocultivar células madre mesenquimales derivadas de tejido adiposo. 2- Se ha comprobado la seguridad de las células madre derivadas de tejido adipos...

  4. Ecuaciones en derivadas parciales con condiciones de contorno no lineales aplicaciones a la dinámica de tumores

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    Morales-Rodrigo, Cristian

    2009-01-01

    Esta tesis presenta tres partes: En la primera haremos un estudio teórico general de las ecuaciones elípticas en derivadas parciales con condiciones de contorno no lineales. Posteriormente, en la segunda, haremos un estudio teórico de ecuaciones elíptica

  5. Aplasia pura de serie roja post-trasplante alogeneico de células progenitoras hematopoyeticas ABO incompatible Pure red cell aplasia after ABO incompatible bone marrow transplantation

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    E. Bulliorsky

    2002-12-01

    Full Text Available El trasplante alogeneico de células progenitoras hematopoyéticas (TCPH con incompatibilidad ABO entre el donante y el receptor puede en ocasiones asociarse a trastornos en la progenie eritroide desarrollada a partir de la médula ósea trasplantada, caracterizado por un funcionamiento tardío, inadecuado e incompleto de la misma. En este contexto, la aplasia pura de serie roja es la complicación más severa. Se han intentado tratamientos para la aplasia pura de serie roja post-TCPH con eritropoyetina o plasmaféresis, con relativo éxito. Algunos autores han informado también la utilización de globulina antilinfocitaria, asumiendo que dicha aplasia selectiva de la serie roja en la médula ósea trasplantada es mediada por un mecanismo inmune. En este trabajo se describe un paciente portador de una leucemia aguda en quien se realizó un TCPH alogeneico (ABO incompatible con su donante. Teniendo niveles bajos de aglutininas contra el grupo sanguíneo de la donante, desarrolló una aplasia pura de serie roja post - TCPH. La misma no mejoró con tratamiento con eritropoyetina o con un refuerzo de progenitores hematopoyéticos de sangre periférica de la misma donante (boost, resolviéndose totalmente luego de un tratamiento exitoso con globulina antilinfocitaria de origen equino.ABO incompatibility in allogeneic bone marrow transplantation may be associated with incomplete or delayed erythroid engraftment, being pure red cell aplasia (PRCA the most severe complication in this setting. Attempts for the treatment of PRCA have been made with erythropoietin or with plasmapheresis with relative success, and some authors have reported the reversibility of PRCA with antilymphocyte globulin (ALG or ATG, based on the assumption that PRCA might be immunologically mediated. We report herewith a patient with acute leukemia who developed post - BMT pure red cell aplasia. His sibling donor (sister was HLA identical and ABO incompatible, having low agglutinin

  6. Caracterización de las lesiones derivadas del entrenamiento físico militar

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    Juan Sebastián Rodríguez Gómez

    2016-01-01

    Full Text Available Introducción: En busca del mejoramiento físico se han desarrollado diferentes formas y maneras de trabajar el cuerpo y así generar el óptimo desarrollo de este en las actividades diarias; es el caso del entrenamiento físico militar, el cual conlleva a unas altas exigencias físicas en los cadetes por el tiempo de concentración, las horas de entrenamiento y la densidad de las actividades las cuales se dan de manera diaria por lo que esta práctica se encuentra asociada inevitablemente con la aparición de lesiones. Objetivo: Caracterizar las lesiones derivadas del entrenamiento físico militar en cadetes de tercero, cuarto y quinto nivel de la Escuela Militar de Cadetes General José María Córdova. Materiales y Métodos: Se planteó un estudio descriptivo de corte transversal, con una muestra tomada aleatoriamente para los hombres  y se tomó a todas las mujeres por ser una cantidad menor en cada uno de los niveles. El instrumento aplicado se validó a través de test-retest y juicio de expertos. Resultados y Discusión: Se encontró que la principal lesión dentro de estos niveles es la periostitis, seguida de lesiones como fisuras, tendinitis y esguinces por sobrecargas que se presentan en el entrenamiento, mala técnica e inadecuada rehabilitación. Conclusiones: La carga física a la que están sometidos constantemente los cadetes es elevada por lo que es una población que se encuentra siempre expuesta a sufrir lesiones importantes en sus extremidades inferiores debido a factores como la indumentaria militar, carga del entrenamiento, práctica deportiva, terreno y falta de descanso como lo expresan los cadetes. Cómo citar este artículo: Rodríguez JS, Valenzuela JA, Velasco JD, Castro LE, Melo PJ. Caracterización de las lesiones derivadas del entrenamiento físico militar. Rev Cuid. 2016; 7(1: 1219-26. http://dx.doi.org/10.15649/cuidarte.v7i1.301

  7. Desarrollo histórico-epistemológico de la derivada de una funcíón

    OpenAIRE

    Ávila, Jesús; Ávila, Ramiro; Parra, Francisco

    2013-01-01

    En este trabajo, presentamos algunos resultados del estudio realizado sobre el desarrollo epistemológico de la derivada, llevado a cabo bajo la perspectiva teórica del Enfoque Ontosemiótico de la Cognición y la Instrucción Matemática (EOS) de J. D. Godino. Aquí mostramos, cómo el objeto derivada de una función, al igual que la matemática en general, es una herramienta construida socialmente por el hombre en el análisis, la interpretación y resolución de un cierto tipo de problemas relacionado...

  8. Epitelización inducida por células troncales derivadas del tejido adiposo

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    M. Meruane

    2014-06-01

    Full Text Available El tratamiento de lesiones con pérdida de tejido cutáneo ha mejorado notablemente con el advenimiento de la bioingeniería tisular. Una alternativa en desarrollo es la utilización de sustitutos dérmicos combinados con células troncales derivadas del tejido adiposo autólogo. Estudios previos nos muestran que con esta técnica es posible optimizar la angiogénesis y la síntesis de colágeno, sin embargo potenciar la epitelización es un tema pendiente por resolver. En el presente estudio evaluamos la progresión y diferenciación epitelial en un período de tiempo prologando. Obtuvimos las células troncales a partir del tejido adiposo (ASC de la región inguinal de 4 ratas Sprague Dawley. Cultivamos las células frescas en una matriz de Integra® durante un período total de 48 horas, y las marcamos con un vector lentiviral-GFP (proteína fluorescente verde. Posteriormente, injertamos en las mismas ratas la matriz dérmica con células troncales y un implante contralateral sin células, como control. A las 4 semanas, evaluamos el avance epitelial mediante planimetría de superficie e histología. Los resultados macroscópicos muestran que el cierre de la herida por contracción de los bordes no tiene diferencias significativas (82,63% ± 3,4% vs. 80,66% ± 3,89%; p=0,08, pero el cierre por epitelización fue significativamente mayor en el lado intervenido con ASCs (93,47% ± 5,98% vs. 79,88% ± 6,28%; p=0,0028. Todas las muestras obtuvieron tinción positiva para el anticuerpo anti-citoqueratina 34βE12 y el avance epitelial lineal cuantificado por microscopía resultó significativamente mayor en el lado con ASCs (6408 ± 275μm vs. 5375 ± 250μm; p < 0,001. Identificamos las células GFP positivas formando parte de la dermis regenerada, no así en la epidermis. En conclusión, las células troncales derivadas del tejido adiposo autólogo sembradas en una matriz de Integra® aumentan la formación epitelial significativamente

  9. Resolución de problemas de control estocástico de Mayer mediante ecuaciones en derivadas parciales

    OpenAIRE

    Josa-Fombellida, Ricardo; Rincón-Zapatero, Juan Pablo

    2007-01-01

    En este trabajo proporcionamos condiciones necesarias y suficientes de optimalidad en problemas de control óptimo estocástico de tipo Mayer en tiempo continuo. Nuestro enfoque está basado en el principio del máximo estocástico. Caracterizamos un control óptimo directamente mediante una ecuación en derivadas parciales, alternativa a la ecuación de Hamilton– Jacobi–Belman, pero que también permite obtener la función valor de una forma indirecta. Los resultados se ilustran con ...

  10. Construcción de soluciones precisas de problemas mixtos para ecuaciones en derivadas parciales con coeficientes variables separables.

    OpenAIRE

    ALMENAR BELENGUER, PEDRO

    2009-01-01

    En esta memoria se construyen soluciones analítico-numéricas con cotas de error a priori de problemas mixtos relacionados con ecuaciones en derivadas parciales con coeficientes separables y condiciones de contorno de tipo Dirichlet. Mediante estrategias de truncación de soluciones formales en serie, el métido de autofunciones y métodos multipaso, se construyen aproximaciones analítico-numéricas con un error prefijado en un dominio acotado. La ecuación de difusión, de ondas y del telégrafo con...

  11. Resolución de ecuaciones diferenciales en derivadas parciales dependientes del tiempo de segundo orden utilizando diferencias finitas generalizadas

    OpenAIRE

    Ureña, Francisco; Benito, Juan José; Gavete, Luis; Álvarez, Ramón (Álvarez Arza)

    2003-01-01

    En este artículo se muestra la eficiencia del método de diferencias finitas generalizadas (MDFG) en la resolución , por el método explícito, de ecuaciones diferenciales en derivadas parciales dependientes del tiempo de segundo orden para una o dos dimensiones espaciales. La obtención de fórmulas explícitas en diferencias finitas generalizadas permite establecer un sencillo criterio de estabilidad, que viene expresado en función de los coeficientes de la ecuación de la estrella. ...

  12. Técnicas Monte Carlo aplicadas a la resolución de ecuaciones en derivadas parciales

    OpenAIRE

    Armando Serrano Lombillo

    2009-01-01

    En este trabajo se aplican las técnicas Monte Carlo a la resolución de ecuaciones en derivadas parciales, en concreto a la ecuación del calor. Si bien estas técnicas no mejoran las técnicas clásicas proporcionan una manera alternativa y más intuitiva de entender los métodos tradicionales. La última parte del trabajo se dedica al estudio estadístico de la importancia de cuatro factores en la precisión del método Monte Carlo. Para realizar el estudio se utilizó Statgraphics y Mathematica....

  13. Un indicador de la comprensión del esquema derivada: el uso de las relaciones lógicas

    OpenAIRE

    Sánchez-Matamoros, Gloria; García, María Mercedes; Llinares, Salvador

    2007-01-01

    Desde distintos planteamientos las investigaciones han proporcionado información sobre las características de la comprensión del concepto de derivada en los estudiantes. Sin embargo, falta más información sistemática sobre indicadores que ayuden a describir el desarrollo de la comprensión de dicho concepto. En este trabajo, desde la teoría piagetiana del desarrollo de un esquema a través de los niveles intra, inter, trans, caracterizamos una evidencia empírica de cómo el uso que se hace de la...

  14. Espectrofotometria derivada: uma contribuição prática para o desenvolvimento de métodos

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    ELIANE MARIA DONATO

    2010-06-01

    Full Text Available A espectrofotometria derivada (ED tem sido utilizada como uma importante ferramenta no controle de qualidade de medicamentos para a determinação simultânea de fármacos em sistemas multicomponentes. Esta técnica oferece uma alternativa para melhorar a sensibilidade e a seletividade na análise de misturas e está acessível à maioria dos laboratórios. O procedimento é simples, rápido e não necessita extração prévia da amostra. Este trabalho tem como objetivo fornecer subsídios para o desenvolvimento de método por espectrofotometria derivada, utilizando a técnica do ponto de anulação, visando utilizá-la como um método alternativo no controle de qualidade de fármacos associados e, em especial, nos estudos de dissolução. Muitos subsídios foram retirados da literatura, outros de experiências vivenciadas no laboratório durante o desenvolvimento do método por ED aplicado na análise de dois inibidores da protease do vírus da imunodeficiência humana. Várias ordens de derivadas, diferentes valores de lambda delta ( e diferentes velocidades de varredura foram avaliados. Palavras chaves: Análise de misturas binárias. Espectrofotometria derivada. Método zero-crossing. ABSTRACT A contribution to the derivative spectrophotometry method Derivative spectrophotometry has been successfully used as a quality control tool in pharmaceutical analysis for the simultaneous determination of drugs in multi-component formulations. This technique, accessible to most laboratories, offers an alternative means of enhancing the sensitivity and specificity in mixture analysis. The procedure is simple, rapid and does not require any preliminary separations or treatment of the samples. The aim of this study is to provide pointers for the development of methods of analysis by derivative spectrophotometry (DS, using the zero-crossing technique, and to encourage professionals and researchers to use DS as an alternative method for

  15. Espectrofotometria derivada: uma contribuição prática para o desenvolvimento de métodos

    OpenAIRE

    ELIANE MARIA DONATO; NATALIA ALEJANDRA PISONI CANEDO; ANDRéIA INêS HORN ADAMS; PEDRO EDUARDO FRöEHLICH; ANA MARIA BERGOLD

    2010-01-01

    A espectrofotometria derivada (ED) tem sido utilizada como uma importante ferramenta no controle de qualidade de medicamentos para a determinação simultânea de fármacos em sistemas multicomponentes. Esta técnica oferece uma alternativa para melhorar a sensibilidade e a seletividade na análise de misturas e está acessível à maioria dos laboratórios. O procedimento é simples, rápido e não necessita extração prévia da amostra. Este trabalho tem como objetivo fornecer subsídios para o desenvolvim...

  16. Controle de esterilidade de produtos de células progenitoras hematopoéticas do sangue periférico Sterility control of hematopoietic progenitor cells from peripheral blood products

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    Igor D. Almeida

    2010-02-01

    Full Text Available A taxa de contaminação microbiana dos produtos de células progenitoras hematopoéticas do sangue periférico é baixa. Neste estudo pesquisou-se a prevalência de hemoculturas positivas em células progenitoras hematopoéticas do sangue periférico (CPHSP no Serviço de Hemoterapia do Hospital de Clínicas de Porto Alegre. Do total de 618 coletas realizadas no período de 2000 a 2007, 26 (4,2% apresentaram contaminação por bactérias. O Staphylococcus coagulase-negativo foi predominantemente isolado nas hemoculturas. A antibioticoterapia pré e pós-infusão foi estabelecida de acordo com o microorganismo e seu antibiograma, sendo que, em cinco das doze infusões contaminadas realizadas, não foram administrados antimicrobianos profilaticamente. Episódios febris foram observados em sete pacientes (58%, enquanto cinco (42% não apresentaram febre. Das doze infusões contaminadas realizadas, seis (50% apresentaram hemocultura pós-descongelamento positivas, enquanto as restantes (50% foram negativas. Isto se deve às propriedades bactericidas do DMSO, de células fagocitose-ativas e de temperaturas muito baixas atingidas na criopreservação. Autores têm relatado sucesso neste procedimento após a infusão desses produtos contaminados com o mínimo de consequências clínicas.The rate of microbial contamination of hematopoietic progenitor cell products from peripheral blood is low. In this study, we investigated the prevalence of positive blood cultures of hematopoietic progenitor cells from peripheral blood in a hemotherapy service. Of a total of 618 samples taken during the period from 2000 to 2007, 26 (4.2% were contaminated by bacteria. Staphylococcus coagulase-negative was the predominant bacterium isolated in blood cultures. Pre- and post-infusion antibiotic therapy was established depending on the microorganism and antibiogram, whereas in five out of twelve contaminated infusions, no antibiotics were administered prophylactically

  17. Interacciones en un escenario en línea. El papel de la socioepistemología en la resignificacion del concepto de derivada

    OpenAIRE

    Gisela Montiel

    2005-01-01

    Este documento sintetiza los resultados de una investigación (Montiel, 2002) que trata sobre las interacciones del sistema didáctico en un escenario virtual, particularmente cuando docentes de matemáticas en servicio confrontan sus nociones alrededor de la derivada en situación escolar. Reportaremos, con fundamento en la aproximación socioepistemológica y sobre la base de la evidencia empírica, cómo se logra una situación de aprendizaje alrededor del concepto de derivada, vista como la organi...

  18. Técnicas Monte Carlo aplicadas a la resolución de ecuaciones en derivadas parciales

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    Armando Serrano Lombillo

    2009-06-01

    Full Text Available En este trabajo se aplican las técnicas Monte Carlo a la resolución de ecuaciones en derivadas parciales, en concreto a la ecuación del calor. Si bien estas técnicas no mejoran las técnicas clásicas proporcionan una manera alternativa y más intuitiva de entender los métodos tradicionales. La última parte del trabajo se dedica al estudio estadístico de la importancia de cuatro factores en la precisión del método Monte Carlo. Para realizar el estudio se utilizó Statgraphics y Mathematica.

  19. Importância de polimorfismos de genes reguladores de citocinas em transplantes de células progenitoras hematopoiéticas Importance of regulatory cytokine gene polymorphisms in hematopoietic stem cell transplantation

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    Jeane Eliete Laguila Visentainer

    2008-12-01

    Full Text Available A compatibilidade genética HLA entre doador e receptor é um fator importante para o sucesso do transplante de células progenitoras hematopoiéticas (TCPH. No entanto, outros genes não-HLA estão sendo investigados em relação ao seu papel na incidência e gravidade da doença do enxerto contra o hospedeiro e na sobrevida, por modularem a intensidade da inflamação e os danos teciduais. Estes genes, não-HLA, incluem os genes de citocinas com polimorfismos dentro das seqüências 5' ou 3' regulatórias dos genes. Os polimorfismos ou microssatélites podem alterar a ligação dos fatores de transcrição aos sítios dentro dos genes promotores e a quantidade de citocina produzida. Este estudo revisa o papel potencial destes polimorfismos genéticos relativos às citocinas em prever o curso do TCPH.HLA genetic matching of donor and recipient is an important requirement for optimizing outcome following hematopoietic stem cell transplantation (HSCT. However, other non-HLA genes are being investigated for their role in graft-versus-host disease incidence and severity and in survival, by modulating the intensity of inflammation and tissue injury. These non-HLA-encoded genes include cytokine genes with polymorphisms within the 5' or 3' regulatory sequences of the genes. The polymorphisms or microsatellites may alter the transcription factor binding sites within the gene promoters and the amount of cytokine produced. This chapter summarizes the potential role of these genetic polymorphisms regarding the cytokines in predicting outcome of HSCT.

  20. Establecimiento y caracterización de una línea celular derivada de un glioblastoma multiforme

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    Verónica Rincón

    2007-03-01

    Full Text Available Introducción: Las líneas celulares y los cultivos primarios son una excelente herramienta para el estudio de la biología, desarrollo y respuesta a la terapia en tumores cerebrales.Objetivo: Establecer y caracterizar una línea celular derivada de un glioblastoma multiforme como un modelo de estudio in vitro para la extrapolación y aplicación futura en terapia génica. Material y métodos: Se obtuvo una muestra de un paciente con diagnóstico clínico e histopatológico de glioblastoma multiforme, se caracterizó mediante inmunohistoquímica en cortes de tejido y por inmunocitoquímica sobre células cultivadas a partir del tumor desde el inicio del cultivo y durante los seis primeros pases, con dos tipos de marcadores específicos para glía: GFAP (glial fibrillary acidic protein y S-100 (proteína de unión a calcio. Además, se evaluó la expresión de p53 y Bcl-2, como moduladores de apoptosis. Por último se hizo la caracterización citogenética.Resultados: Histopatológicamente, se confirmó el diagnóstico de glioblastoma multiforme. En los cultivos primarios se encontraron características citomorfológicas propias de un glioblastoma: células fibroblastoides planas, células con escaso citoplasma con 3 ó más procesos y por último bipolares o unipolares. Se encontró una expresión diferencial con los cuatro marcadores, con un patrón de marcaciones a nivel citoplasmático y nuclear a través de los pases estudiados. La línea celular se caracterizó por ser en su mayoría aneuploide con un número modal cromosómico entre 43 y 45, con un gran número de poliploidías (55-102 , XXYY y endo-reduplicaciones (end 45, X, -Y.Conclusión: Se estableció una línea celular derivada de un glioblastoma multiforme con un fenotipo estable, con un notable mantenimiento del perfil glial y citogenético.

  1. Células-tronco derivadas de tecido adiposo humano: desafios atuais e perspectivas clínicas Human adipose-derived stem cells: current challenges and clinical perspectives

    OpenAIRE

    Samira Yarak; Oswaldo Keith Okamoto

    2010-01-01

    As células-tronco adultas ou somáticas detêm grande promessa para a reparação e regeneração de tecidos. Atualmente, o interesse dos cientistas é contínuo na investigação da biologia de células-tronco mesenquimais, tanto em aspectos básicos, quanto no potencial de aplicações terapêuticas. As células-tronco adultas derivadas do estroma do tecido adiposo, em comparação com as células-tronco derivadas do estroma da medula óssea, apresentam como vantagem o método fácil de obtenção da fonte tecidua...

  2. Determinación de vitamina B 12 en una formulación multivitamínica por espectrofotometría de derivada de primer orden

    OpenAIRE

    Sordo Martínez, Lissette; Soto Mulet, Laritza; González Hernández, Rolando

    1999-01-01

    Se desarrolló un método por espectrofotometría de derivadas de primer orden para la determinación de vitamina B12 en una formulación multivitamínica compuesta por vitamina B1, B6 y B12. La amplitud de la señal de la primera derivada se determinó a 378 nm. La validación prospectiva del método demostró que fue lineal (r=0,999), preciso (repetibilidad CV=0 y 132%; reproducibilidad CV=2,7 y 1,67 %), exacto y selectivo (se determinó B12 en presencia de las vitaminas B1, B6 y en presencia de los pr...

  3. El daño como elemento fundamental para la exigencia de la responsabilidad civil derivada del delito

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    Iracema Gálvez Puebla

    2014-06-01

    Full Text Available La perspectiva estructural que se sigue con la investigación, parte de sugerentes cuestiones sobre el daño como eje central dentro de la responsabilidad civil derivada del delito; así como de la naturaleza y funciones de la obligación civil ex delito, teniendo en cuenta tres hipótesis fundamentales que abordan tanto su naturaleza puramente civil, hasta valorarla como perteneciente a la materia penal, concluyendo con el análisis de la esencia mixta de la institución, en base a fundamentos políticos- sociales, de la imposición sancionadora que logra la satisfacción del perjudicado- acreedor, al venir impuesta por el ordenamiento jurídico frente a un daño que confirma la interrelación de los elementos sobre la causa efficiens y la causa finalis de la obligación específica, que parte de una relación jurídica funcionalmente organizada.

  4. El daño como elemento fundamental para la exigencia de la responsabilidad civil derivada del delito

    Directory of Open Access Journals (Sweden)

    Iracema Gálvez Puebla

    2014-06-01

    Full Text Available La perspectiva estructural que se sigue con la investigación, parte de sugerentes cuestiones sobre el daño como eje central dentro de la responsabilidad civil derivada del delito; así como de la naturaleza y funciones de la obligación civil ex delito, teniendo en cuenta tres hipótesis fun- damentales que abordan tanto su naturaleza puramente civil, hasta valorarla como perteneciente a la materia penal, concluyendo con el análisis de la esencia mixta de la institución, en base a fundamentos políticos- sociales, de la imposición sancionadora que logra la satisfacción del per- judicado- acreedor, al venir impuesta por el ordenamiento jurídico frente a un daño que con- firma la interrelación de los elementos sobre la causa efficiens y la causa finalis de la obligación específica, que parte de una relación jurídica funcionalmente organizada.

  5. Poliuretana derivada de óleos vegetais exposta ao intemperismo artificial Polyurethane derived from vegetal oil exposed to artificial weathering

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    Alessandra E. F. S. Almeida

    2006-01-01

    Full Text Available Foram obtidas as propriedades mecânicas e viscoelásticas da poliuretana derivada do óleo de mamona após sua exposição ao intemperismo artificial, a fim de avaliar a aplicabilidade deste material como revestimento polimérico para substratos de concreto na Construção Civil. Os procedimentos experimentais foram realizados em conformidade com a ASTM G 53 for "Operating Light and Water Exposure Apparatus (Fluorescent UV - Condensation Type for Exposure of Nonmetallic Materials"[1]. O ensaio para a caracterização mecânica dos corpos-de-prova após exposição ao intemperismo artificial foi realizado conforme a norma ASTM D 638M-96 "Standard Test Method for Tensile Properties of Plastics (Metric"[2]. Foi empregado o método de análise dinâmico-mecânica para a obtenção das propriedades viscoelásticas da poliuretana vegetal. Os resultados mostraram que a exposição ao intemperismo artificial não ocasionou mudanças significativas nas propriedades do revestimento polimérico para o tempo de exposição estudado.The mechanical and viscoelastic properties of polyurethane derived from castor oil were obtained after being exposed to artificial weathering with the purpose of evaluating their applicability as polymeric coatings on concrete substrate for Civil Construction. The procedures followed the ASTM G53 for "Operating Light and Water Exposure Apparatus (Fluorescent UV - Condensation Type for Exposure of Nonmetallic Materials"[1]. Mechanical properties were obtained by means of the ASTM D 638M-96 "Standard Test Method for Tensile Properties of Plastics (Metric"[2]. Furthermore, a Dynamic Mechanical Analysis (DMA was carried out in order to study the viscoelastic properties of polyurethane. The results showed that the properties were altered slightly considering the time studied.

  6. Procesos de resignificiación del valor numérico de la función derivada segunda: un estudio en el sistema escolar uruguayo

    OpenAIRE

    Cantoral, Ricardo; Testa, Yacir

    2006-01-01

    Reportamos los resultados de una investigación desarrollada con estudiantes uruguayos respecto del significado gráfico que asignan al valor numérico de la función derivada segunda, y de cómo influye y se desarrolla su Pensamiento y Lenguaje Variacional (PyLV) al trabajar en actividades que ponen en juego dicho valor numérico. Mediante un análisis del contenido temático de los cursos, y del enfoque curricular, de la bibliografía empleada y de los antecedentes de investigación, observamos que s...

  7. Introducción al concepto de derivada de una función real con apoyo de las tecnologías digitales

    OpenAIRE

    Cuevas, Carlos Armando; Rodríguez, Arturo; González, Oscar

    2014-01-01

    Este artículo presenta una propuesta para introducir el concepto de derivada de una función real en un primer curso de cálculo diferencial a nivel superior. Para el desarrollo de esta propuesta se han tomado elementos del desarrollo histórico conceptual del cálculo, la aplicación de una ingeniería didáctica en particular y de manera importante el empleo de la tecnología digital. Los resultados obtenidos son alentadores, porque se logró que la mayoría de los estudiantes alcanzaron con éxito un...

  8. Estimación de biomasa fitoplanctónica, derivada de datos de satélite, frente a Baja California Sur

    OpenAIRE

    Saúl Álvarez Borrego; Eduardo Santamaría del Ángel; Iriana Leticia Zuria Jordan; Frank E. Müller Karger

    1995-01-01

    Se utilizaron todas las estimaciones disponibles de la concentración de pigmentos fotosintéticos derivadas de datos generados por el sensor Coastal Zone Color Scanner (CZCS) en el periodo 19781986, para interpretar las variaciones espaciales y temporales de la biomasa de fítoplancton, en un transecto de punta San Hipólito (27”N, ll4”30’0) a cabo Corrientes (20”3O’N, 105”30’0), frente al sur de Baja California, México. Las mayores concentraciones de pigmentos fotosintéticos se presentaron cerc...

  9. La derivada a la caratheodory, una nueva concepción en el aprendizaje y la enseñanza del calculo

    OpenAIRE

    Vargas, Angélica Roció; Torres, María Andrea; Quintero, Nidia Lucia

    2009-01-01

    A nivel educativo la noción de derivada se enseña en los cursos regulares de cálculo, pero por lo general, siempre en la forma en que fue definida por Cauchy, lo que implica un procedimiento se hace necesario hacer una factorización. Constantin Caratheodory establece una definición diferente. Esta definición presenta tres aspectos didácticos destacados: Nos muestra que el proceso de acercamiento de las pendientes de las secantes a la pendiente de la tangente es continuo y por tanto, la contin...

  10. Una secuencia didáctica para la introducción del concepto de derivada. Resultados de su implementación

    OpenAIRE

    Vrancken, Silvia; Engler, Adriana; Müller, Daniela

    2010-01-01

    En el ámbito de la investigación en Matemática Educativa son conocidas las dificultades que plantean la enseñanza y el aprendizaje de contenidos del cálculo. En la búsqueda de alternativas que favorezcan un desarrollo adecuado de métodos de pensamiento propios de la matemática, diseñamos y pusimos a prueba una secuencia didáctica para la introducción del concepto de derivada. Consideramos como hipótesis básica que el desarrollo de ideas variacionales puede propiciar una mejor comprensión y...

  11. Serological monitoring of a Toxoplasma infection after hematopoietic stem cell transplantation Monitoramento sorológico de uma infecção toxoplásmica após transplante de células progenitoras hematopoiéticas

    Directory of Open Access Journals (Sweden)

    Cláudio L. Rossi

    2010-08-01

    Full Text Available We report a primary response to Toxoplasma gondii following a hematopoietic stem cell transplantation in a patient with multiple myeloma. The primary response to T. gondii was supported by IgM, IgG and IgA seroconversion. The patient was promptly treated and there were no complications related to toxoplasmosis in the subsequent months.Esse relato de caso descreve uma resposta primária ao Toxoplasma gondii após transplante de células progenitoras hematopoiéticas em paciente com mieloma múltiplo. A resposta primária para o T. gondii foi evidenciada pela soroconversão observada na resposta de anticorpos IgM, IgG e IgA. O paciente foi prontamente tratado e complicações relacionadas à toxoplasmose não foram observadas nos meses subseqüentes.

  12. Allogeneic hematopoietic stem cell transplantation for primary myelodysplastic syndrome Transplante alogênico de células progenitoras hematopoiéticas para síndrome mielodisplásica primária

    Directory of Open Access Journals (Sweden)

    Carlos R. Medeiros

    2004-01-01

    Full Text Available Characteristics and outcomes of 52 patients with myelodysplastic syndrome (MDS who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT were analyzed. Median age was 30 years (range 2-61 years and median time from diagnosis to allo-HSCT was 10 months (range 1-161 months. Thirty-six patients had advanced MDS or acute myeloid leukemia following MDS at transplant. Conditioning with busulfan and cyclophosphamide was administered to 73% of patients, and the median value of graft dose was 2.595 x 10(8 of total nucleated cells/kg. Overall survival and disease free survival at 4 years were 36% and 33%, respectively. Nineteen patients were alive, with a median follow-up of 3.8 years. Twelve patients relapsed and only one is alive, after donor lymphocyte infusion. Interval II occurred in 19 patients. Donor type (identical related versus non-related/partially matched related influenced the incidence of acute GVHD (P = 0.03. Eleven patients developed chronic GVHD and previous acute GVHD was a risk factor (P = 0.03. Thirty-three patients died, 22 (67% secondary to transplant-related complications. Patients with MDS should undergo allo-HSCT earlier, mainly if they have a compatible donor and are young.Características e resultados de 52 pacientes com síndrome mielodisplásica (MDS submetidos a transplante alogênico de células progenitoras hematopoiéticas (TCPH foram analisados. A idade mediana foi de 30 anos (variação de 2-61 anos e o tempo mediano entre o diagnóstico e transplante foi de dez meses (variação de 1-161 meses. Trinta e seis pacientes tinham MDS avançada ou leucemia mielóide aguda secundária a MDS ao transplante. O condicionamento com busulfano e ciclo­fosfamida foi recebido por 73% dos pacientes, e a dose celular mediana do enxerto foi de 2.56 x 10(8 células nucleadas/kg. A sobrevida global e a sobrevida livre de doença aos quatro anos foi de 36% e 33%, respectivamente. Dezenove pacientes estavam vivos, com um

  13. Composición química de cúmulos globulares galácticos: metalicidades derivadas a partir de fotometría de Washington

    Science.gov (United States)

    Torres, M. C.; Clariá, J. J.

    Se presentan temperaturas efectivas y abundancias de 183 gigantes rojas en 7 cúmulos globulares galácticos, derivadas a partir de fotometría de Washington realizada en Cerro Tololo. Las metalicidades provienen de una calibración que tiene en cuenta la disminución de sensibilidad de algunos índices con la temperatura. Los valores medios de [Fe/H] obtenidos oscilan entre -1.2 y -2.15, con errores típicos del orden de 0.2 salvo un par de excepciones. Teniendo en cuenta que el índice (C-T1) es significativamente más sensible a la metalicidad que (V-I), se presenta una calibración de abundancia basada en el color (C-T1)o de la rama gigante roja para una determinada magnitud absoluta M(T1). Las abundancias derivadas confirman en general la escala de Zinn (1985, ApJ, 293, 424).

  14. Autografting of peripheral-blood progenitor cells early in chronic myeloid Leukemia Transplante autólogo de células progenitoras em fase crônica precoce da Leucemia mielóide crônica

    Directory of Open Access Journals (Sweden)

    Paulo V. B. Carvalho

    2004-12-01

    Full Text Available The role of peripheral-blood progenitor cell (PBPC transplantation as a treatment for chronic myeloid leukemia (CML patients remains uncertain. We presented herein 11 CML patients treated with autografting of PBPC in early chronic phase followed by interferon-alpha (IFN-alpha. Bone marrow samples obtained at diagnosis and during follow-up after autografting as well as leukapheresis products were analyzed by cytogenetics, fluorescence in situ hybridization (FISH and reverse transcriptase-polymerase chain reaction (RT-PCR. The median follow-up of patients after autografting was 22 months (range: 1-49. Two treatment-related deaths occurred in patients enrolled in the study. Eight out of 9 (88.9% and 7 out of 9 (77.8% patients achieved hematologic and cytogenetic responses, respectively. Molecular cytogenetic and molecular responses were seen in all 7 patients analyzed (100.0% and in one single patient (11.1%, respectively. The median percentages of Ph+ (78.0% metaphases obtained after 6 months of autografting was lower than those obtained at diagnosis (100.0%, P=0.04. The median percentages of FISH+ nuclei obtained at 3 (4.0%, 6 (7.3% and 9 (14.7% months after autografting were also lower than that obtained at diagnosis (82.5%; P=0.002; P=0.003; P=0.030, respectively. At the end of the study, 9 patients (81.8% were alive in chronic phase, 4 of them presenting hematologic, cytogenetic and molecular cytogenetic responses. We conclude that autografting performed with PBPC in early chronic phase of CML followed by IFN-alpha results in lower numbers of Ph+ and FISH+ cells in bone marrow.O papel do transplante de célula progenitora periférica (CPP como tratamento de pacientes com leucemia mielóide crônica (LMC permanece incerto. Nós apresentamos neste estudo 11 pacientes com LMC tratados com o transplante autólogo (TMO-auto de CPP durante a fase crônica precoce, seguido de interferon-alfalfa (IFN-alfa. Amostras de medula óssea, obtidas ao diagn

  15. Evaluación de una estrategia didáctica para la apropiación del concepto “derivada de una función”

    Directory of Open Access Journals (Sweden)

    Felipe Santoyo Telles

    2016-06-01

    Full Text Available La enseñanza tradicional del cálculo diferencial presenta grandes dificultades respecto a la apropiación significativa del concepto derivada de una función. Dado lo anterior, se construyó una propuesta didáctica considerando al conocimiento como una construcción personal a partir de los esquemas de cada sujeto y una negociación intersubjetiva de significados; asimismo, se considera al profesor como un promotor o mediador de la interacción entre los sujetos cognoscentes y el objeto cognoscible. Sobresalen los procesos de organización y adaptación con una estructura que atiende los principios del proceso de asimilación–acomodación de Piaget, y que provocan el cambio de estructura, desarrollo y aprendizaje. Los contenidos de la propuesta se presentan contextualizados y organizados bajo una secuencia lógica en un cuadernillo de trabajo. Finalmente, la propuesta se experimentó y valoró mediante la prueba t student con resultados positivos.

  16. Análisis simultáneo de la remoción de azul brillante y rojo 40 mediante espectrofotometría de derivadas

    Directory of Open Access Journals (Sweden)

    Yurany Villada

    2015-01-01

    Full Text Available Los efluentes de industrias como la alimentaria y textil contienen induda - blemente una mezcla de colorantes. No obstante, la evaluación de estos sistemas multicomponentes ha sido poco explorada debido a la comple - jidad para su cuantificación. Como una aproximación más cercana a la contaminación de estos vertimientos, se evaluó la adsorción de la mezcla de colorantes rojo 40 ( R40 y azul brillante ( AB sobre corteza de coco bajo sistema discontinuo, considerando las variables p H , concentración inicial de los colorantes, dosificación de adsorbente y temperatura. Para su cuan - tificación se utilizó el modelo de las primeras derivadas, haciendo uso de un espectrofotómetro UV-V is Lambda 35. Bajo las mejores condiciones, se alcanzó una remoción máxima del 76,5% para la mezcla de R40 y AB a p H ácido (p H = 2.0, dosificación de 20 g/ L , concentraciones iniciales de 10 mg/L y temperatura de 55 °C. El porcentaje de error promedio total encontrado para el modelo de cuantificación fue de 1,35% para R40 y 1,10% para AB , lo que señala la validez del método. Además, en la mezcla binaria, el AB experimentó un menor efecto antagonista por la presencia del R40 , con un porcentaje de adsorción 3,7 veces mayor que el obtenido para el R40 .

  17. Desarrollo y optimización de una metodología analítica para la determinación de sedimento en bebida de mesa derivada del cacao

    OpenAIRE

    Torres, Juliana; Tello, Myriam; Ostos, Sandra

    2010-01-01

    Se realizó un estudio encaminado a desarrollar y optimizar una metodología analítica que permita determinar la cantidad de sedimento que presenta una bebida derivada del cacao (chocolate de mesa), para ser aplicada como prueba rutinaria de control de calidad indicadora del proceso, con base en los principios de la sedimentación. Para la caracterización del sedimento, se hizo la distribución de tamaños de partícula, porcentaje de grasa y peso del sedimento en seco. El desarrollo...

  18. Durabilidad, bajo condiciones climáticas, del Panel Compuesto Ligero Autoportante, tipo sándwich, de caras derivadas de la madera, que se emplea como sistema de cerramiento de cubiertas

    OpenAIRE

    Estrada Martínez, Salvador

    2012-01-01

    Durabilidad, bajo condiciones climáticas, del Panel Compuesto Ligero Autoportante, tipo sándwich, de caras derivadas de la madera, que se emplea como sistema de cerramiento de cubiertas. Esta investigación tiene como objetivo el estudio de la degradación, producida por los factores ambientales de humedad y temperatura, del panel compuesto ligero autoportante (panel sándwich) basado en madera, empleado como cobertura de tejados. Se estima que la cuestión no está suficientemente desarrollad...

  19. Determinação de cumarina em extrato fluido e tintura de guaco por espectrofotometria derivada de primeira ordem Determination of coumarin in fluid extract and tinture of "guaco" by first derivative spectrophotometry

    Directory of Open Access Journals (Sweden)

    Adriana de Carvalho Osório

    2004-12-01

    Full Text Available O objetivo do trabalho foi desenvolver um método de doseamento de cumarina (1,2-benzopirano em extrato fluido e tintura de guaco (Mikania glomerata Sprengel. O método desenvolvido foi por espectrofotometria derivada de primeira ordem, que se mostrou preciso, exato, reprodutível e de fácil execução.The objective of this work was to develop a method for coumarin(1,2-benzopyran dosage in fluid extract and tinture of "guaco" (Mikania glomerata Sprengel. First derivative spectrophotometry was developed and proved to be accurate, exact, reprodutive and of easy execution.

  20. Determinação de cumarina em extrato fluido e tintura de guaco por espectrofotometria derivada de primeira ordem Determination of coumarin in fluid extract and tinture of "guaco" by first derivative spectrophotometry

    OpenAIRE

    Adriana de Carvalho Osório; Jorge Luiz Seferin Martins

    2004-01-01

    O objetivo do trabalho foi desenvolver um método de doseamento de cumarina (1,2-benzopirano) em extrato fluido e tintura de guaco (Mikania glomerata Sprengel). O método desenvolvido foi por espectrofotometria derivada de primeira ordem, que se mostrou preciso, exato, reprodutível e de fácil execução.The objective of this work was to develop a method for coumarin(1,2-benzopyran) dosage in fluid extract and tinture of "guaco" (Mikania glomerata Sprengel). First derivative spectrophotometry was ...

  1. Pérdidas productivas y económicas diarias ocasionadas por la mastitis y erogaciones derivadas de su control en establecimientos lecheros de Córdoba, Argentina

    Directory of Open Access Journals (Sweden)

    C Vissio

    2015-01-01

    Full Text Available El propósito de este estudio fue estimar los costos diarios directos de la mastitis y las erogaciones derivadas de su control y prevención, y describir su magnitud y variación entre establecimientos lecheros de una de las principales cuencas lecheras de Argentina. Una muestra aleatoria de establecimientos lecheros (n = 48 fueron visitados una sola vez. En todas las vacas en ordeño se verificó la presencia de mastitis clínica (MC y a 1.955 vacas seleccionadas aleatoriamente se les extrajo una muestra compuesta de leche para determinación de recuento celular somático (RCS. Simultáneamente se examinó la rutina de ordeño y se analizó una encuesta aplicada al encargado de ordeño. Se caracterizaron y cuantificaron las pérdidas productivas y económicas de acuerdo con el RCS, en concepto de leche descartada por MC y las erogaciones por acciones de control y prevención. La mediana de pérdidas directas invisibles fue de 2,8 litros/vaca/día (percentil 25% = 2,0; percentil 75% = 2,9 para el conjunto de animales en estudio, representando un costo de US$ 0,99/vaca/día. La mediana de pérdidas en el establecimiento atribuidas a MC fue de 0,12 litros/vaca/día (percentil 25% = 0; percentil 75% = 0,31, representando un costo de US$ 0,04/vaca/día. La mediana de pérdidas indirectas fue de US$ 0,06/vaca/día (percentil 25% = 0,034; percentil 75% = 0,095. En el 50% de los establecimientos el costo total, es decir, adicionando las pérdidas en producción de leche a los gastos del control y prevención fue ≥ US$ 1,0/vaca/día (percentil 25% = 0,8; percentil 75% = 1,2. El costo total de la mastitis, representó en promedio 16% de los ingresos brutos diarios en al menos la mitad de los establecimientos. Al analizar los establecimientos de acuerdo con tres niveles de producción, no se observaron diferentes perfiles de costos; con excepción de la relación costos sobre ingresos brutos, la que fue mayor en el estrato de menor producción. Este es

  2. Modelo de cuantificación de las emisiones de CO2 producidas en edificación derivadas de los recursos materiales consumidos en su ejecución

    Directory of Open Access Journals (Sweden)

    Olivares, M.

    2012-09-01

    Full Text Available Research in this paper focuses on the generation of a model to quantify CO2 emissions in the implementation of a typical building block for affordable residential housing, derived from the manufacturing process of the materials used in its construction. The identification and quantification of building materials consumed, will reveal the environmental impact of producing the type defined by one of the indicators most relevant environmental impact associated with weight per m2 of construction, such as CO2 emissions resulting from manufacturing process of the construction materials used in its implementation. Its practical application to a set of ten projects located in Seville implementation, will provide conclusive data on the quantification of CO2 emissions in its implementation by identifying the greatest environmental impact.La investigación realizada en el presente trabajo plantea la generación de un modelo de cuantificación de las emisiones de CO2 producidas en la ejecución del modelo constructivo habitual definido como el bloque residencial destinado a viviendas de protección oficial, derivadas del proceso de fabricación de los recursos materiales empleados en su ejecución. La identificación y cuantificación de los materiales de construcción consumidos, permitirá conocer el impacto medioambiental que produce la tipología definida, a través de uno de los indicadores de impacto ambiental más relevantes asociados al peso por m2 de construcción, como son las emisiones de CO2 derivadas del proceso de fabricación de los materiales de construcción empleados en su ejecución. Su aplicación práctica a un conjunto de diez proyectos de ejecución ubicados en Sevilla, proporcionará datos concluyentes sobre la cuantificación de las emisiones de CO2 producidas en su ejecución, identificando los de mayor impacto ambiental.

  3. La diabetes altera el potencial osteogénico de células progenitoras de médula ósea: Efectos del tratamiento con metformina Diabetes Decreases the Osteogenic Potential of Bone Marrow Progenitor Cells: Effects of Treatment with Metformin

    Directory of Open Access Journals (Sweden)

    MJ Tolosa

    2012-06-01

    Full Text Available En este trabajo, estudiamos el efecto de una Diabetes inducida por destrucción parcial de la masa de células beta pancreáticas, sobre el compromiso osteogénico de células progenitoras de médula ósea (CPMO, y su modulación por el tratamiento oral con Metformina. Para ello utilizamos ratas Sprague Dawley, divididas en cuatro grupos: controles [C], controles tratadas con Metformina [M], diabéticas [D], y diabéticas tratadas con Metformina [DM]. La inducción de Diabetes se realizó, por inyección intraperitoneal sucesiva de ácido nico-tínico y estreptozotocina. Sobre los cultivos de CPMO se evaluó la actividad específica de Fosfatasa Alcalina (FAL y la producción de Colágeno tipo 1 (Col-1 en estado basal y en medio de diferenciación osteogénico luego de 15 días. A los 21 días, se evaluaron los depósitos de mineral extracelular. La FAL y el Col-1 de CPMO basales, no mostraron diferencias significativas entre los cuatro grupos experimentales. Al cabo de 15 días, las CPMO de ratas M mostraron un incremento en el Col-1 de 122 % respecto de C; D 30 % respecto de C y DM 68 % respecto de C. La FAL expresó un 171 % para M, 34 % para D; y 125 % para DM todos respecto de C. Luego de 21 días, se observó una disminución en la mineralización de las CPMO de D (65 % respecto del grupo C. El tratamiento con metformina incrementó la mineralización de las CPMO en todos los casos. En conclusión, en nuestro modelo experimental de Diabetes, ésta disminuye el potencial osteogénico de las CPMO, un efecto que es parcialmente revertido por el tratamiento oral con Metformina. Estos hallazgos podrían explicar, al menos en parte, las alteraciones óseas descriptas en el hueso asociadas con la Diabetes. Los autores declaran no poseer conflictos de interés.Diabetes mellitus is associated with an increased incidence of skeletal abnormalities, resulting in lower bone formation and/or remodeling. Osteopenia, osteoporosis and an increased

  4. Detección de patologías derivadas de las afecciones diabéticas: una revisión del análisis digital de imágenes de retina

    Directory of Open Access Journals (Sweden)

    Jorge Rudas

    2013-01-01

    Full Text Available Las afecciones diabéticas tienen impacto sobre el deterioro de las estruc- turas internas del sistema circulatorio de la retina. La retinopatía diabética es considerada la causa principal de ceguera en poblaciones adultas, este aspecto ha motivado el desarrollo de numerosos trabajos relacionados con la inclusión de técnicas computacionales en el análisis de retinografías. Este trabajo examina y describe la literatura reciente relacionada con el procesamiento digital de retinografías, particularmente la automatización de los procesos de detección, segmentación y localización de patologías derivadas de las afecciones producidas por el padecimiento de la retino- patía diabética. Se realizó una clasificación basada en el tipo de patología, lesiones oscuras y lesiones brillantes.

  5. Comparison of serology, antigenemia assay and the polymerase chain reaction for monitoring active cytomegalovirus infections in hematopoietic stem cell transplantation patients Estudo comparativo entre sorologia, antigenemia e reação em cadeia da polimerase para o monitoramento da infecção por citomegalovírus em pacientes receptores de transplantes de células progenitoras hematopoéticas

    Directory of Open Access Journals (Sweden)

    Sandra Helena Alves Bonon

    2006-10-01

    Full Text Available Forty-six allogeneic hematopoietic stem cell transplantation (HSCT patients were monitored for the presence of CMV antibodies, CMV-DNA and CMV antigens after transplantation. Immunoenzymatic serological tests were used to detect IgM and the increase in CMV IgG antibodies (increase IgG, a nested polymerase chain reaction (N-PCR was used to detect CMV-DNA, and an antigenemia assay (AGM was used to detect CMV antigens. The presence of CMV-IgM and/or CMV-increase IgG antibodies was detected in 12/46 (26.1% patients, with a median time between HSCT and the detection of positive serology of 81.5 days. A positive AGM was detected in 24/46 (52.2% patients, with a median time between HSCT and antigen detection of 62 days. Two or more consecutive positive N-PCR results were detected in 32/46 (69.5% patients, with a median time between HSCT and the first positive PCR of 50.5 days. These results confirmed that AGM and mainly PCR are superior to serology for the early diagnosis of CMV infection. Six patients had CMV-IgM and/or CMV-increase IgG with a negative AGM (five cases or N-PCR assay (one case. In five of these cases the serological markers were detected during the first 100 days after HSCT, the period of highest risk. These findings support the idea that serology may be useful for monitoring CMV infections in HSCT patients, especially when PCR is unavailable.Quarenta e seis pacientes receptores de transplantes de células progenitoras hematopoéticas (TCPH foram monitorados em relação à infecção ativa por citomegalovírus (CMV. Testes sorológicos imunoenzimáticos foram utilizados para a detecção de anticorpos IgM e elevação significativa das concentrações de anticorpos IgG (aumento IgG, nested-PCR (N-PCR foi utilizada para a detecção de CMV-DNA e antigenemia (AGM para a detecção de antígenos virais. A presença de CMV-IgM e/ou CMV-aumento IgG foi detectada em 12/46 (26,1% pacientes, sendo o tempo mediano entre o transplante e a detec

  6. Germinação e desenvolvimento inicial de plântulas de soja convencional e sua derivada transgênica RR em condições de estresse salino Germination and initial development of soybean seedlings and their transgenic derivatives in salt stress condition

    OpenAIRE

    Tereza Cristina de Carvalho; Sibelle Santanna da Silva; Rosemeire Carvalho da Silva; Maristela Panobianco

    2012-01-01

    O Brasil destaca-se como um dos maiores produtores mundiais de soja transgênica, sendo sua produção estendida principalmente a regiões com solos salinos, onde há acúmulo de sais que interferem na germinação da semente e no desenvolvimento das plântulas. O objetivo da pesquisa foi avaliar o efeito do estresse salino sobre a germinação e o desenvolvimento inicial de plântulas de soja convencional e sua derivada transgênica Roundup Ready (RR), submetidas a diferentes condições de salinidade. Par...

  7. Guía sobre la tributación de las rentas derivadas de la cesión de los derechos de imagen en el IRPF: en particular el régimen especial (artículo 76 Ley del IRPF)

    OpenAIRE

    Andrés Aucejo, Eva

    2003-01-01

    El presente artículo trata la regulación jurídica del derecho al valor comercial de la propia imagen ('Publicity right' según terminología anglosajona), la regulación tributaria del derecho al valor comercial de la propia imagen y el régimen especial de la tributación de rentas derivadas de la cesión del derecho a la explotación comercial de la imagen.

  8. Avaliações clínica, ecográfica e anatomofisiológica do alotransplante parcial de vesícula urinária com células-tronco mesenquimais alogênicas derivadas do tecido adiposo em coelhos

    OpenAIRE

    S.T.L. Pinto Filho; Oliveira, M. T.; J. S. Aramburú Junior; W. G. Glanzner; T. O. Silva; J.P.S. Feranti; P.B.D. Gonçalves; Cruz, I. B. M.; M.V. Brun; N.L. Pippi

    2015-01-01

    RESUMOOs problemas relacionados ao armazenamento vesical são muitos e relevantes. Eles, além de influírem de forma efetiva na qualidade de vida, podem eventualmente evoluir para falência renal. Existem vários trabalhos, os quais descrevem as propriedades imunomoduladoras e imunossupressoras das células-tronco mesenquimais derivadas do tecido adiposo (ADSCs). Objetiva-se com o presente avaliar clínica, ecográfica e anatomofisiologicamente o alotransplante parcial de bexiga a fresco em coelhos,...

  9. Uso de proteínas derivadas de la matriz del esmalte en defectos infraóseos periodontales: Presentación de casos clínicos Use of proteins enamel matrix derivative in infrabony periodontal defects: Presentación de casos clínicos

    OpenAIRE

    Alonso A; L Aracil; Blanco, J; D Rodrigo; A Bascones

    2006-01-01

    La periodontitis es una infección crónica causada por las bacterias de la placa dental. Esta condición induce la perdida de soporte del aparato de inserción. La cirugía está indicada para detener la progresión de la enfermedad y regenerar el tejido perdido. Se han utilizado diferentes técnicas quirúrgicas para regenerar los tejidos periodontales incluyendo la regeneración tisular guiada (RTG), y el uso de proteínas derivadas de la matriz del esmalte (EMD). Las EMD contienen amelogenina. Se sa...

  10. Aplicação do método da espectrofotometria de derivadas na identificação e doseamento simultâneo de sistemas multicomponentes Application of derivative spectrophotometric method in identification and simultaneous analysis of multi-component system

    OpenAIRE

    Luís Roberto Paschoal; Weverson Alves Ferreira; Mara Régia Dias Prado; Ana Paula Oliveira Vilela

    2003-01-01

    Neste trabalho, demonstrou-se a aplicação do método da espectrofotometria de derivadas no doseamento simultâneo de alguns fármacos em produtos farmacêuticos comerciais. Os métodos desenvolvidos apresentaram-se precisos, sensíveis, seletivos, reprodutivos e de baixo custo.The application of the derivative spectrophotometric method in the simultaneous determinations of some drugs in commercial pharmaceutical products is demonstrated in this work. The developed methods proved to be selective, re...

  11. Interacciones bióticas en lagos Antárticos. Investigaciones derivadas del proyecto LIMNOPOLAR en la Península Byers (Antártida marítima

    Directory of Open Access Journals (Sweden)

    C. Rochera

    2011-01-01

    Full Text Available La estructura trófica de las comunidades planctónicas de los lagos antárticos se caracteriza por su sencillez, estando funcionalmente dominada por microorganismos. En estas cadenas tróficas el zooplancton, cuando está presente, ocupa generalmente la posición de consumidores superiores. Estos sistemas constituyen un marco muy adecuado en el que evaluar ciertos aspectos de la ecología trófica y funcional. Nuestro propósito ha sido valorar la aplicabilidad de una serie de teorías ecológicas, relativas a las relaciones tróficas, al flujo de energía y a la relativa importancia de los factores tanto abióticos como bióticos como elementos que expliquen el funcionamiento de estos ecosistemas en zonas polares sometidas a un fuerte control físico. Estudios experimentales llevados a cabo en lagos de la Península Byers (Isla Livingston por nuestro grupo de investigación han puesto de manifiesto como determinadas interacciones bióticas, como la depredación, podrían ejercer este efecto estructurador, a pesar del fuerte control físico que supuestamente aleja a estas comunidades del equilibrio. De nuestros resultados se deriva la existencia de cascadas tróficas en el plancton con potencialidad de extenderse en el bucle microbiano. Especialmente relevantes resultan aquellas interacciones derivadas de la actividad del zooplancton. En particular, la presencia de éstos parece inducir un incremento en las densidades de las poblaciones del picoplancton vía disminución de los organismos bacterívoros. De nuestras investigaciones se deriva también la capacidad de este zooplancton para acelerar el reciclado de nutrientes, la cual debe contribuir en parte a sostener la productividad del sistema. Estas observaciones han permitido bosquejar un modelo conceptual del funcionamiento de la red trófica pelágica. El aumento progresivo de las temperaturas en áreas polares podría acrecentar las entradas de energía y activar el ciclo de nutrientes

  12. ESTUDOS SOBRE ABORDAGENS TERAPÊUTICAS PARA O ACIDENTE VASCULAR ENCEFÁLICO (AVE EM MODELO ANIMAL: USO DE CÉLULAS DERIVADAS DE MEDULA ÓSSEA E DE FLAVONOIDES

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    Arthur Giraldi-Guimarães

    2012-01-01

    Full Text Available O Acidente Vascular Encefálico é a maior causa de incapacitação em seres humanos adultos, representandoatualmente um grande custo pessoal e social. Empregando modelos experimentais de lesões cerebrais focais,este projeto tem como objetivo geral avaliar o efeito benéfico de abordagens terapêuticas promissoras notratamento do AVE e de outras lesões cerebrais. Em estudos concluídos, tivemos como objetivo principalavaliar a capacidade de indução de recuperação funcional em testes sensorimotores pelas terapias comcélulas derivadas de medula óssea e com o flavonoide rutina. Foram utilizados o modelo de isquemia corticalfocal unilateral por termocoagulação dos vasos cortical superficiais, e o modelo da ablação cortical focalunilateral por sucção, ambos causando lesão de mesma localização e extensão. Nossos resultados mostraramque as células mononucleares de medula óssea (MNMOs e as células-tronco mesenquimais (CTMs foramcapazes de promover recuperação de função sensorimotora em testes de movimentos menos sofisticados, em21ambos os modelos de lesão. Entretanto, as MNMOs não promoveram aumento da recuperação demovimentos de destreza, que envolvem treinamento, como agarrar uma pílula de ração. No estudo com oflavonoide rutina, demonstramos que houve promoção de recuperação sensorimotora após a isquemia, e estase correlacionou com uma ação neuroprotetora do flavonoide. Nossos resultados sugerem que tanto asMNMOs e como a rutina podem ser utilizados como terapias eficazes para o tratamento de lesões cerebrais,quando administradas na fase aguda da doença. Os estudos precisam ser aprofundados no sentido de ampliaros conhecimentos sobre os seus respectivos mecanismos celulares e moleculares de ação.

  13. Hidrocefalia derivada na infância: um estudo clínico-epidemiológico de 243 observações consecutivas Shunted hydrocephalus in childhood: an epidemiological study of 243 consecutive observations

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    Susana Ely Kliemann

    2005-06-01

    Full Text Available Os objetivos deste estudo foram analisar as características epidemiológicas e clínicas de 243 crianças com hidrocefalia derivada, acompanhadas durante 1 a 27 anos, assim como identificar os fatores relacionados aos distúrbios psicomotores, epilepsia e ao óbito. A meningite pós-derivação e os distúrbios mecânicos do sistema foram as complicações mais freqüentes (22,3% e 30,7%, respectivamente. A média de derivação por paciente foi 1,47. Distúrbios motores graves ocorreram em 34,3%, déficit cognitivo em 58,5% e epilepsia em 43,6% dos pacientes. Os distúrbios motores correlacionaram-se positivamente com o grau da hidrocefalia. Houve maior incidência de déficit cognitivo e epilepsia nos casos de hidrocefalia pós-meningite. O óbito ocorreu em 52 pacientes e estes apresentaram um percentual maior de neoplasia do sistema nervoso central e de distúrbios motores na última avaliação, assim como de retirada da primeira derivação por meningite precoce, ocorrida até 2 meses após a derivação.This study aimed to evaluate the epidemiological and clinical data of 243 children with shunted hydrocephalus, followed-up during 1 to 27 years, as well as to identify the risk factors for psychomotor disturbances, epilepsy and death. Postoperative meningitis and mechanical problems were the most frequent complications (22.3% and 30.7%, respectively. There was an average of 1.47 shunt per patient. Severe motor disturbances occurred in 34.3%, cognitive deficits in 58.5% and epilepsy in 43.6%. Motor disturbances correlated positively with the degree of hydrocephalus. The majority of patients with hydrocephalus due to meningitis presented cognitive deficits and a significant incidence of epilepsy. Death occurred in 52 patients and there was a higher percentage of brain tumours in this group, as well as the replacement of the first shunt device due to precocious postoperative meningitis.

  14. Efeitos funcionais da terapia autóloga de células-tronco derivadas da medula óssea (Cd45+ e Cd34-) no trauma raquimedular agudo nos murinos: sedentários e treinados físicos

    OpenAIRE

    Cunha, Ricardo Corrêa da

    2013-01-01

    Resumo: A terapia celular e o exercício físico podem ser uma opção para regeneração da lesão medular espinal traumática. Este estudo tem por objetivo avaliar os efeitos funcionais da terapia autóloga de células-tronco derivadas da medula óssea: fração mononuclear no trauma raquimedular agudo em ratos sedentários e treinados. Foram utilizados 70 ratos Wistar, machos, submetidos à lesão medular contusa por impacção (Impactor NYU). Após este procedimento, os animais foram acompanhados e avaliado...

  15. Uso de proteínas derivadas de la matriz del esmalte en defectos infraóseos periodontales: Presentación de casos clínicos Use of proteins enamel matrix derivative in infrabony periodontal defects: Presentación de casos clínicos

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    Alonso A

    2006-04-01

    Full Text Available La periodontitis es una infección crónica causada por las bacterias de la placa dental. Esta condición induce la perdida de soporte del aparato de inserción. La cirugía está indicada para detener la progresión de la enfermedad y regenerar el tejido perdido. Se han utilizado diferentes técnicas quirúrgicas para regenerar los tejidos periodontales incluyendo la regeneración tisular guiada (RTG, y el uso de proteínas derivadas de la matriz del esmalte (EMD. Las EMD contienen amelogenina. Se sabe que la amelogenina está relacionada con la formación del esmalte, y también con la formación de la inserción periodontal durante la formación dentaria. A través de esta presentación de dos casos clínicos tratados con Proteínas derivadas de matriz de esmalte EMDOGAIN®, se pretende , por un lado describir paso a paso el procedimiento clínico de su uso y a la vez hacer una revisión de la literatura de la regeneración periodontal y de la regeneración utilizando Emdogain® en particular.Periodontitis is a chronic infective disease of the gums caused by bacteria present in dental plaque. This condition induces the breakdown of the tooth supporting apparatus until teeth are lost. Surgery may be indicated to arrest disease progression and regenerate lost tissues. Several surgical techniques have been developed to regenerate periodontal tissues including guided tissue regeneration (GTR, and the use of proteins enamel matrix derivative (EMD. EMD is an extract of enamel matrix and contains amelogenins. There is evidence to show that amelogenins are involved not only in enamel formation, but also in the formation of the periodontal attachment during tooth formation. Accordly to two clinicals cases treated with Endogain, the aim of this presentation is, first to describe the clinical procedure,and second to make a literature review of the differents materials to periodontal regeneration.

  16. Isolamento, cultivo e diferenciação de células tronco mesenquimais caninas

    OpenAIRE

    Patricio, Lia Fordiani Lenati

    2012-01-01

    Resumo: As celulas tronco sao celulas nao diferenciadas de embrioes, fetos ou tecidos adultos, com o potencial de gerar celulas de diversos tecidos sob o estimulo bioquimico, hormonal e mecanico adequado, in vitro ou in vivo. As celulas tronco embrionarias e fetais sao pluripotentes e as celulas tronco adultas sao multipotentes e nao especializadas. Dentre as celulas tronco adultas, as celulas tronco mesenquimais (CTMs) ja foram identificadas em diferentes orgaos e tecidos, como tecido adipos...

  17. Células madre y células troncoembrionarias: diferencias biológicas

    OpenAIRE

    Dolly Macías Riveros; Juan Carlos Vázquez Chagoyán; Rogelio Alonso Morales; Marco Cajero Juárez

    2007-01-01

    Las células madre o progenitoras se han clasifi cado según su lecho natural de derivación, su aptitud y su función diferencial, en tres tipos: totipotenciales, pluripotenciales y multipotenciales; las primeras, llamadas células madre embrionarias, derivadas del cigoto en estadio de mórula; las segundas, provenientes de la masa celular interna (MCI) del blastocisto; las terceras, denominadas células madre somáticas, se encuentran en algunos tejidos adultos. La diferencia biológica radica en su...

  18. LA RESPONSABILIDAD DE LAS COOPERATIVAS DERIVADA DEL INCUMPLIMIENTO DE LAS OBLIGACIONES CONTABLES. INFLUENCIA DE LA REFORMA PENAL Y LA NUEVA REGULACIÓN CONTABLE / THE CRIMINAL RESPONSABILITY OF THE COOPERATIVES ARISING FROM NOT COMPLYING WITH THE ACCOUNTING OBLIGATIONS. THE REPERCUSSION OF THE REFORM OF THE PENAL CODE AND THE NEW ACCOUNTING REGULATION

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    Maria Begoña VILLARROYA LEQUERICAONANDIA

    2012-05-01

    Full Text Available El objetivo perseguido con la realización de este trabajo es conocer la responsabilidad penal derivada del incumplimiento de las obligaciones contables por parte de los órganos sociales de las cooperativas, observando la incidencia de la reforma del Código Penal en la responsabilidad. Para ello, se comienza haciendo una breve descripción de las obligaciones contables, no solo el deber de llevanza de la contabilidad, libros obligatorios,… sino también las obligaciones específicas de las cooperativas recientemente reguladas en la Orden de 21 de diciembre de 2010 sobre los aspectos contables de las sociedades cooperativas (BOE de 29 de diciembre, donde nos encontramos con numerosos cambios en los que parte de las aportaciones de los socios pasarán a calificarse como pasivo. A continuación se analizan los distintos artículos del Código Penal en los que la contabilidad tuviera relevancia, incidiendo en como podría verse afectada la responsabilidad de la empresa con la reciente reforma. / The aim of this work is to know the criminal responsibility for social organs arising from not complying with the accounting obligations and the repercussion of the reform of the Penal Code in the treatment of responsibility. The paper starts with a brief description of the accounting obligations, not only formal but also material obligations, and the specific rules for the valuation of cooperatives that have recently been regulated in the Order of December 21, 2010 (BOE December, 29 of the countable aspects of cooperative companies will be analyzed in this paper. In it we will find numerous changes in whicht parts of the contributions of the partners will be classified as debts.. Finally, this work analyzes various articles of the Criminal Code in which the accounting is most important, highlighting the possibility of responsibility of the companies after the new reform.

  19. Estado actual de las terapias con células madre derivadas de tejido adiposo en el ámbito de la Cirugía Plástica The state of the adipose-derived stem cell therapies in Plastic Surgery

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    J.M. Lasso

    2010-09-01

    Full Text Available Durante la última década, la terapia celular ha emergido como una estrategia útil en el tratamiento de diversas enfermedades como la isquemia miocárdica y las fístulas en la enfermedad de Crohn; pero últimamente, hay también ya líneas de investigación centradas en su uso en reconstrucción mamaria, cuyos resultados van siendo publicados paulatinamente. Existen varios tipos de células madre adultas que han sido investigadas en estudios preclínicos y clínicos diseñados para este propósito: células de medula ósea, células del sistema circulatorio y mioblastos y, recientemente se está trabajando en una población de células madre en el tejido adiposo, que presentan una fácil extracción y manipulación. Estas células son capaces de diferenciarse en múltiples líneas celulares, como los adipocitos y las células endoteliales entre otras. En el presente artículo, trataremos de hacer una revisión de los principios básicos de las células madre derivadas del tejido adiposo (tipos, características, procesos de obtención y multiplicación, los primeros estudios experimentales y los ensayos clínicos que están siendo realizados en la actualidad.Over the past decade, cell therapy has emerged as a new approach to reverse several diseases as myocardial ischemia and fistula in Crohn disease; but lately new efforts are centered in breast reconstruction. Several types of adult stem cell have been studied in both preclinical and clinical condition for this purpose: bone marrow cells, circulating cells, and myoblasts. Recently the existence of a population of stem cells located in the adipose tissue has been observed. These cells are able to differentiate into multiple cell lineage including adipocytes and endothelial cells. In this review we discuss the basic principle of adipose-derived stem cell (types, characteristic, harvesting and expansion, the initial experimental studies and the currently ongoing clinical trials.

  20. Sistemas radiolarios: geometrías y arquitecturas derivadas

    OpenAIRE

    Mallo Zurdo, María

    2015-01-01

    Uno de los temas más importantes dentro del debate contemporáneo, es el que se refiere a la sostenibilidad a largo plazo de la sociedad tal y como la entendemos hoy. El ser humano está recuperando la sensibilidad perdida que le concebía como una pieza más dentro del ciclo natural de la vida. Por fin hemos entendido que no podemos ser auto suficientes e independientes del entorno natural que nos rodea. Más allá del respeto y del cuidado, está abierta la puerta del conocimiento infinito que nos...

  1. Modelos en desarrollo de terapias derivadas de biotecnologia

    OpenAIRE

    Jaimes Monroy, Gustavo

    2008-01-01

    El objetivo de la terapia génica para el tratamiento del cáncer es eliminar las células tumorales preservando el tejido normal. Diversas estrategias para llevar acabo este objetivo han demostrado resultados promisorios en el laboratorio, incluyendo moléculas que pueden tener blancos específicamente predeterminados en secuencias en el ADN y el ARNm; estas secuencias proporcionan un medio para modular la función de genes endógenos. Diferentes tipos de moléculas: inductores de hélices triples, o...

  2. Hemocidinas derivadas da hemoglobina: estruturas, propriedades e perspectivas

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    Larissa A. C. Carvalho

    2013-01-01

    Full Text Available The increasing incidence of microbial infections, high toxicity, and high level of resistance associated with conventional antibiotics has created a need for new drugs. Antimicrobial peptides (AMPs constitute a promising alternative and/or an important source of knowledge given their ability to inhibit the growth and/or to kill bacteria, fungi, parasites and/or viruses through mechanisms of action different from those of non-peptide drugs. This review focused on this important class of organic compounds that includes hemocidins resulting from hemoglobin proteolysis in vivo and in vitro or from chemical synthesis, subject of research in foreign and Brazilian laboratories.

  3. Estudio del metabolismo del glicolato en celulas de Chlamydomonas reinhardtii

    OpenAIRE

    Borrero Rubio, José Antonio

    1994-01-01

    En este trabajo pretendemos contribuir a los actuales conocimientos sobre el metabolismo del glicolato en Chlamydomonas reinhardtii desde tres aproximaciones:1. Por una parte , analizar las actividades enzimáticas implicadas en la biosíntesis y oxidación

  4. Stem Cells and Cancer; Celulas madre y cancer

    Energy Technology Data Exchange (ETDEWEB)

    Segrelles, C.; Paraminio, J. M.; Lorz, C.

    2014-04-01

    Stem cell research has thrived over the last years due to their therapeutic and regenerative potential. Scientific breakthroughs in the field are immediately translated from the scientific journals to the mass media, which is not surprising as the characterisation of the molecular mechanisms that regulate the biology of stem cells is crucial for the treatment of degenerative and cardiovascular diseases, as well as cancer. In the Molecular Oncology Unit at Ciemat we work to unravel the role of cancer stem cells in tumour development, and to find new antitumor therapies. (Author)

  5. Estudio comparativo del uso de la matriz ósea desmineralizada de origen humana y de la poliuretana derivada del aceite de mamona sobre el proceso de regeneración ósea: Estudio histométrico en calota de conejos A comparative study on the use of demineralized bone matrix of human origin and polyurethane derived from castor oil in bone regeneration processes: A histometric study on rabbit calvaria

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    J. Rodrigues Laureano Filho

    2007-08-01

    Full Text Available Objetivo. Analizar histométricamente el efecto de la matriz ósea desmineralizada de origen humana y de la resina poliuretana derivada del aceite de mamona, sobre el proceso de regeneración ósea. Diseño del estudio: fueron utilizados 24 conejos y en cada calota craniana fueron preparadas dos cavidades quirúrgicas, siendo una a cada lado de la sutura parietal. Los animales fueron divididos en dos grupos. En el grupo I la cavidad experimental (lado derecho fue rellenada con la poliuretana derivada del aceite de mamona, mientras que en el grupo II la cavidad experimental fue rellenada con la matriz ósea desmineralizada de origen humano. Las cavidades de control fueron rellenadas solo con la sangre del animal. Los animales fueron sacrificados en los períodos postoperatorios de 04, 07 y 15 semanas. Resultados. El análisis estadístico, realizado en base de los datos de la histometría, mostró una mayor neoformación ósea de los grupos I y II en relación al grupo control, no existiendo diferencia estadística cuando los grupos experimentales fueron comparados. Conclusiones. El uso de poliuretana derivada del aceite de mamona y matriz ósea desmineralizada de origen humano mejoran el proceso de regeneración cuando lo comparamos a la regeneración ósea normal resultando que entre ambos materiales tuvieron un comportamiento similar sin diferencias estadísticas significantes entre sí.Objective. The present study was aimed at carrying out a histological and histometric analysis on the effect of human demineralized bone matrix and a polyurethane resin, derived of the castor bean oil, on the bone regeneration process. Design: For this, 24 rabbits were used and in each calvarium two surgical bone defect were prepared, one on the right side and another on the left side of the parietal suture. The animals were divided into two groups. In group I the experimental defect (right side was filled with polyurethane derived from oil of the castor oil

  6. Determinação da glibenclamida por espectrofotometria derivada no ultravioleta para avaliação do teste ou perfil de dissolução de comprimidos Glibenclamide determination by derivative ultraviolet spectrophotometry for test or dissolution profile assessment in tablets

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    Janaina Diniz Martins

    2007-03-01

    Full Text Available A glibenclamida (GLIB ou gliburida, agente hipoglicemiante oral de segunda geração, da classe das sulfoniluréias, é usada sob a forma de comprimidos para controle do diabetes mellitus. Possui baixa solubilidade aquosa, podendo proporcionar baixa liberação no teste de dissolução de comprimidos e acarretar variabilidades no tratamento. A solução metanólica de GLIB apresenta máximos de absorção em lambda 210 nm, 227,5 nm e 300 nm na região ultravioleta (UV. Após liberaçao de comprimidos, a sua determinação espectrofotométrica na região UV é dificultada devido à baixa concentração proporcionada após o teste de dissolução (comprimidos GLIB 5 mg, volume de meio 900 mL, 0,56 mg% e à baixa absortividade em comprimento de onda característico, lambda 300 nm. Por estas razões, até hoje, não existe um método de análise proposto para o teste de dissolução em farmacopéias nacional ou estrangeiras para monografia de glibenclamida comprimidos. A falta de uniformidade nestes procedimentos onera a execução de testes de dissolução para verificação da equivalência farmacêutica de especialidades candidatas a genéricos. Este trabalho propõe a determinação espectrofotométrica de GLIB por derivada de primeira e segunda ordens (máximos lambda 238 nm e 218 nm, respectivamente, em tampão fosfato 0,1 mol L-1, utilizando comprimidos referência e teste contendo 5 mg de fármaco por dose unitária.Glibenclamide (GLIB or glyburide, a second-generation oral hypoglycemic drug, is used in the tablet form for the treatment of diabetes mellitus. Because of the low aqueous solubility of this sulfonylurea, a low drug release in the dissolution test may occur, hence, causing variabilility in the treatment. GLIB methanolic solution shows UV absorption maxima in lambda 210 nm, 227.5 nm and 300 nm. After released from tablets in the dissolution test, its spectrophotometric determination is difficult due to the low drug concentration

  7. Análise clínica, radiológica, macroscópica e histológica do úmero de codornas domésticas (Coturnix japonica, submetido ao implante da poliuretana derivada do polímero de mamona (Ricinnus communis Clinical, radiological, macroscopical and histological analysis of domestic quail (Coturnix japonica humerus submitted to implant of polyurethane from castor oil polymer (Ricinnus communis

    Directory of Open Access Journals (Sweden)

    Juliano Bolson

    2005-10-01

    Full Text Available Na cirurgia ortopédica, são freqüentes as situações em que o cirurgião se depara com grandes perdas ósseas, provocadas especialmente por traumatismos de alta energia, tumores ou infecções. A reparação dessas fraturas requer grande conhecimento a respeito de materiais que possam ser utilizados para preencher essas falhas. Esses materiais podem ser derivados biológicos, sintéticos ou metálicos. Dentre eles, destacam-se os enxertos ósseos e os implantes de biomateriais. Com o aumento dos animais exóticos, utilizados como animais de estimação, a casuística clínica e cirúrgica dessa especialidade vem crescendo, tanto em clínicas quanto em hospitais veterinários. Particularmente, as aves constituem a maioria desses animais, e entre seus problemas cirúrgicos as fraturas são os de maior destaque. O objetivo deste trabalho foi estudar o efeito clínico, radiológico, macroscópico e histológico da poliuretana derivada do polímero de mamona (Ricinnus communis implantada no úmero de codornas domésticas (Coturnix japonica. Para isso, foram utilizadas 20 codornas, machos e fêmeas, separadas aleatoriamente em quatro grupos de cinco animais, os quais receberam o implante no úmero esquerdo, com exame clínico diário durante o período pós-operatório, avaliações radiológica imediata e quinzenal e macroscópica e histológica aos 15, 30, 60 e 90 dias. Clinicamente não foram observadas alterações locais, regionais nem sistêmicas. Ao exame radiológico, notou-se aumento de densidade local, sem sinais de alteração óssea, dos tecidos circunjacentes, e de sacos aéreos. A análise macroscópica revelou que a poliuretana de mamona não foi absorvida em nenhum dos quatro grupos permanecendo implantada no seio do osso pneumático, porém, notou-se alteração em sua resistência. O exame histopatológico mostra inicialmente mínima reação inflamatória, discreta fibrose ao redor do implante e osteointegração pela presen

  8. Biomass gasification and fuel cells: system with PEM fuel cell; Gaseificacao de biomassa e celula a combustivel: sistema com celula tipo PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Sordi, Alexandre; Lobkov, Dmitri D.; Lopes, Daniel Gabriel; Rodrigues, Jean Robert Pereira [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Fac. de Engenharia Mecanica], e-mail: asordi@fem.unicamp.br, e-mail: lobkov@fem.unicamp.br, e-mail: danielg@fem.unicamp.br, e-mail: jrobert@fem.unicamp.br; Silva, Ennio Peres da [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Fisica Gleb Wataghin], e-mail: Lh2ennio@ifi.unicamp.br

    2006-07-01

    The objective of this paper is to present the operation flow diagram of an electricity generation system based on the biomass integrated gasification fuel cell of the type PEMFC (Proton Exchange Membrane Fuel Cell). The integration between the gasification and a fuel cell of this type consists of the gas methane (CH4) reforming contained in the synthesis gas, the conversion of the carbon monoxide (CO), and the cleaning of the gaseous flow through a PSA (Pressure Swing Adsorption) system. A preliminary analysis was carried out to estimate the efficiency of the system with and without methane gas reforming. The performance was also analyzed for different gasification gas compositions, for larger molar fractions of hydrogen and methane. The system electrical efficiency was 29% respective to the lower heating value of the gasification gas. The larger the molar fraction of hydrogen at the shift reactor exit, the better the PSA exergetic performance. Comparative analysis with small gas turbines exhibited the superiority of the PEMFC system. (author)

  9. Condiciones suficientes de estabilidad para Ecuaciones en Derivadas Parciales estocásticas con retardos

    OpenAIRE

    Caraballo Garrido, Tomás

    1988-01-01

    Sufficient conditions for pathwise exponential stability of the zero solution of stochastic PDE with deviating argument dxt = Axt dt + Bx (t) dwt are given. The assumptions on the operators A and B are the same that in the case without delay, but the proof is different. In fact, our method shows an alternative proof for the results in the particular case (t) = t : First, we obtain su cient conditions for the second moment of xt to decay exponentially. Next, asymptotic exponential stabil...

  10. Soluciones numéricas estables de sistemas acoplados mixtos de ecuaciones en derivadas parciales.

    OpenAIRE

    Casabán Bartual, Mª Consuelo

    2010-01-01

    Esta memoria trata sobre la construcción de soluciones numéricas estables de sistemas parabólicos e hiperbólicos acoplados. Las etapas características de esta memoria son: la construcción de soluciones discretas utilizando diferencias finitas y una técnica de separación de variables discreta, el estudio de la estabilidad y la consistencia de la solución calculada, y el empleo de un método de proyecciones para extender los resultados obtenidos a una clase más general de funciones de valores in...

  11. Soluciones por ondas viajeras, y soluciones exactas de ecuaciones en derivadas parciales

    OpenAIRE

    Gomez, Cesar

    2008-01-01

    En este trabajo, consideramos algunos de los métodos utilizados en la obtención de soluciones exactas para ecuaciones diferenciales parciales no lineales, los cuales utilizan la transformación de onda. Con el fin de ilustrar los métodos, obtenemos soluciones exactas del nuevo sistema de Mikhailov–Novikov–Wang.

  12. Ecuación en derivadas parciales de Poisson como problema inverso de momentos

    OpenAIRE

    Pintarelli, María Beatriz; Vericat, Fernando

    2013-01-01

    Usando la identidad de Green mostramos que encontrar soluciones de la ecuación de Helmholtz y la ecuación de Poisson no lineal bajo condiciones de contorno de Cauchy es equivalente a resolver una ecuación integral de Fredholm de primera clase, la cual puede ser tratada como un problema de momentos bidimensional de Hausdorff en el caso lineal y como un problema inverso de momentos generalizado en el caso no lineal. En ambos casos encontramos soluciones aproximadas de los problemas de momentos ...

  13. Aproximación de ecuaciones en derivadas parciales parabólicas, en fluidos

    OpenAIRE

    Redó Caballer, Agustín

    2012-01-01

    La principal motivación que nos ha llevado a desarrollar este proyecto de final de carrera ha sido la importancia de los fluidos, más si cabe en un sector como el naval, en el cual el barco no deja de ser un artefacto flotante que se desplaza a través de un fluido como el agua. Por comentar algunos de los campos que afectan los fluidos en los buques podemos destacar entre muchos dos principales, la hidrodinámica y el comportamiento de los fluidos por el interior de tuberí...

  14. Estudio Cuantitativo del crecimiento de cultivo de Células Madre mesenquimales derivadas de tejido adiposo

    OpenAIRE

    Atea, Carolina Magdalena

    2014-01-01

    Las células madre (SC- Stem Cells) son un tipo especial de células indiferenciadas, con la espacial capacidad de dividirse indefinidamente y diferenciarse a su vez, en distintos tipos de células especializadas, tanto desde el punto de vista morfológico como funcional. Tienen el potencial para convertirse en distintos tipos celulares en el organismo. Por una parte, permiten el desarrollo de un individuo a partir de un ovulo fecundado durante el periodo embrionario y, por otra, d...

  15. SÍNTESE DA PENEIRA MOLECULAR MCM-41 DERIVADA DA CINZA DA CASCA DO ARROZ

    Directory of Open Access Journals (Sweden)

    Renata Martins Braga

    2013-10-01

    Full Text Available As peneiras moleculares MCM-41 têm atraído grande interesse devido as suas propriedades de alta área específica, volume e diâmetro de poros controláveis. Estes materiais são aplicados em diversos ramos da indústria química como adsorventes, suportes catalíticos e catalisadores heterogêneos em vários processos. Neste trabalho, o MCM-41 foi sintetizado a partir da cinza da casca do arroz, natural e tratada quimicamente, como fontes alternativas de sílica, denominadas CCA-MCM-41 e CCAL-MCM-41, respectivamente, com o objetivo de reaproveitar este resíduo e produzir um material mesoporoso de menor custo. Os materiais foram sintetizados pelo método hidrotérmico a partir de um gel com composição molar: CTAMBr 1,0 mol L-1; SiO2 4,0 mol L-1; Na2O 1,0 mol L-1; H2O 200 mol L-1 e caracterizados por FRX, DRX, FT-IR e determinação de área superficial pelo método BET. Os materiais obtidos apresentaram elevada área superfícial específica (905 m2 g-1, com dimensões e volume de poros dentro das especificações de materiais mesoporosos, sendo estas prorpriedades semelhantes ao MCM-41 sintetizado com a sílica gel comercial, comprovando que a cinza da casca do arroz pode ser utilizada como fonte alternativa de sílica na síntese de peneiras moleculares do tipo MCM-41.

  16. Algunos usos de las calculadoras y la computadora para introducir el concepto de derivada

    OpenAIRE

    Borbon, Alexander

    2003-01-01

    Este artículo se basa en que las nuevas tecnologías representan una alternativa para la enseñanza y el aprendizaje de las matemáticas; las calculadoras simples, las calculadoras gráficas y las computadoras han ido desplazando a la tiza y a la pizarra, pues los temas pueden ser mostrados con mayor dinamismo y agilidad. Sin embargo, un problema muy común entre los profesores es que cuentan con la tecnología para innovar, pero no saben como hacerlo, en el artículo se sugieren algunas formas de u...

  17. Preparación y ciclopaladación de bases de Schiff derivadas del ferroceno

    OpenAIRE

    Bosque Pueyo, Ramón

    1994-01-01

    Una de las áreas de la Química Organometálica que ha suscitado mayor interés en los últimos 25 años es el estudio de los procesos de activación de enlaces C-H, mediante compuestos de elementos de transición. Dentro de este contexto los procesos conocidos como reacciones de ciclometalación son unos de los más ampliamente estudiados, y en particular aquellos en los que se utilizan sales de paladio (II) y sustratos orgánicos que poseen nitrógeno como heteroátomo. El mecanismo que se propone en e...

  18. Prótese vascular derivada do látex Latex-derived vascular prosthesis

    Directory of Open Access Journals (Sweden)

    Marcelo Luiz Brandão

    2007-06-01

    Full Text Available CONTEXTO: O desenvolvimento de prótese vascular tem sido vital para os avanços e realizações da cirurgia vascular reconstrutora durante as últimas 5 décadas. OBJETIVOS: Desenvolver um novo modelo de prótese vascular microperfurada, confeccionada em tecido recoberto com um composto derivado do látex natural da seringueira (Hevea brasiliensis e avaliar sua perviedade, trombogenicidade, biocompatibilidade e o processo de cicatrização, além de algumas propriedades mecânicas (adaptabilidade, elasticidade, impermeabilidade e possibilidade de sutura, utilizando como controle a prótese de politetrafluoretileno expandido no mesmo animal. MÉTODOS: Quinze cães foram separados em três grupos de cinco animais. Implantou-se a prótese de tecido e látex microperfurada e, no membro pélvico contralateral, a prótese de politetrafluoretileno expandido em todos os cães. O seguimento pós-operatório foi de 4, 8 e 12 semanas. A apreciação dos resultados foi feita segundo as avaliações clínicas dos pulsos, complicações (coleção líquida, deiscência, granuloma e infecção, arteriografias, análise macroscópica e elétron-micrografias de varredura. RESULTADOS: Os testes estatísticos aplicados não evidenciaram diferenças significativas (p > 0,05 em relação às complicações pós-operatórias e perviedade dos enxertos. Ambas as próteses integraram-se adequadamente aos tecidos circunvizinhos, com um tecido de incorporação formado por fibras colágenas. Constatou-se a presença de neoíntima recoberta por endotélio em toda a extensão da superfície luminal da prótese de tecido e látex microperfurada. Ao contrário, na prótese de politetrafluoretileno expandido, o desenvolvimento endotelial sobre a superfície neointimal limitou-se às regiões próximas às anastomoses. CONCLUSÕES: A prótese de tecido e látex microperfurada demonstrou qualidades estruturais (adaptabilidade, elasticidade, impermeabilidade e possibilidade de sutura satisfatórias como substituto vascular. Estimulou o crescimento endotelial além das regiões de contato com a artéria nas anastomoses e foi biocompatível no sistema arterial do cão, apresentando adequada integração tecidual.BACKGROUND: The development of vascular grafts has been crucial for advances and achievements in reconstructive vascular surgery over the past 5 decades. OBJECTIVES: To develop a new model of microperforated vascular graft using fabric covered with a natural latex-derived polymer taken from Hevea brasiliensis and assess its patency, thrombogenicity, biocompatibility and healing process, besides some mechanical properties (adaptability, elasticity, impermeability and possibility of suture, using expanded polytetrafluoroethylene graft as control. METHODS: Fifteen dogs were divided into three groups of five animals. The microperforated latex graft was implanted in all dogs and the expanded polytetrafluoroethylene graft was implanted in the contralateral pelvic limb. Postoperative follow-up was 4, 8 and 12 weeks. Analysis of results was performed according to clinical evaluation of pulses, complications (fluid collection, dehiscence, granuloma and infection, arteriography, macroscopic analysis and scanning electron micrography. RESULTS: Statistical tests revealed no significant differences (p > 0.05 concerning post-operative complications and graft patency. Both grafts were properly integrated to surrounding tissues, with connective tissue formed by collagen fibers. A neointimal layer covering all extension of the luminal surface was observed in the microperforated latex graft. Conversely, the endothelial development over the neointimal surface was limited to regions adjacent to the anastomoses in the expanded polytetrafluoroethylene graft. CONCLUSIONS: The microperforated latex graft showed satisfactory structural qualities (adaptability, elasticity, impermeability and possibility of suture as a vascular substitute. It stimulated endothelial growth beyond contact regions with the artery in anastomoses and was biocompatible in the d

  19. SÍNTESE DA PENEIRA MOLECULAR MCM-41 DERIVADA DA CINZA DA CASCA DO ARROZ

    OpenAIRE

    Renata Martins Braga; Najara Maira Teodoro; Dulce Maria de Araujo Melo; Flávia de Medeiros Aquino; Joana Maria de Farias Barros; Julio Cezar de Oliveira Freitas

    2013-01-01

    As peneiras moleculares MCM-41 têm atraído grande interesse devido as suas propriedades de alta área específica, volume e diâmetro de poros controláveis. Estes materiais são aplicados em diversos ramos da indústria química como adsorventes, suportes catalíticos e catalisadores heterogêneos em vários processos. Neste trabalho, o MCM-41 foi sintetizado a partir da cinza da casca do arroz, natural e tratada quimicamente, como fontes alternativas de sílica, denominadas CCA-MCM-41 e CCAL-MCM-41, r...

  20. Estabelecimento do Conceito de Temperatura como uma grandeza derivada da Energia e da Entropia

    CERN Document Server

    De Abreu, R

    2002-01-01

    Temperature is introduced as a derived concept from energy and entropy. We consider two sub-systems in equilibrium for several configurations. The equality of temperature of the sub-systems is obtained from the equilibrium condition. The isothermal transformation is defined for several configurations and from this definition we obtain the Clausius-Clapeyron equation. We apply the analysis to the ideal gas. The classical ideal gas appears as a limit and the problem of the measurement of temperature is analysed.

  1. Características del viento en estrellas Be derivadas del perfil Hα

    Science.gov (United States)

    Rohrmann, R.; Cidale, L.

    El estudio teórico de perfiles Hα y su variabilidad en estrellas Be ha sido frecuentemente desarrollado en base a modelos de envolturas circunestelares inhomogéneas, donde la geometría del material es responsable de la forma del perfil dependiendo de la dirección de observación. Nosotros damos una interpretación alternativa y proponemos que la mayoría de las propiedades de esta línea tienen origen en la base de un viento estelar y de una estructura cromosférica anexa a la fotósfera. Encontramos que típicos perfiles Hα en Be, como son los llamados pole-on y winebottle, pueden ser reproducidos cualitativamente sin recurrir a la existencia de una envoltura asimétrica. Analizamos como la línea Hα permite identificar la posible estructura del viento en la región donde éste se inicia.

  2. LA ESTRUCTURA ESCOLAR INHIBIDORA DEL APRENDIZAJE ORGANIZACIONAL: EXPERIENCIA DERIVADA DE CASO

    Directory of Open Access Journals (Sweden)

    David Simonetta

    2010-01-01

    Full Text Available El presente artículo describe resultados y conclusiones de una investigación realizada en un centro escolar de nivel medio llamado Instituto Brigadier General Martín Rodríguez, de financiamiento público y gestión privada, de la ciudad de Tandil, provincia de Buenos Aires, República Argentina. En este artículo se ha abordado la problemática de la estructura del centro escolar y su impacto en la gestión del conocimiento y la generación de aprendizaje organizacional en la escuela. Se investigó distinta bibliografía referida a la estructura organizacional, la gestión del conocimiento, las teorías denominadas principios, disciplinas, o procesos de aprendizaje organizacional, y organización y gestión de centros escolares. Se ha planteado a partir de allí el modelo de observación que caracteriza la dinámica y evolución del aprendizaje organizacional y sus efectos. Directivos, Docentes, Personal de apoyo, Alumnos aportaron sus opiniones para este trabajo. Bajo este modelo de abordaje, se evidencian en el caso planteado características estructurales predominantemente inhibidoras de los procesos de aprendizaje organizacional. Respecto de los conocimientos tratados e intercambiados entre personas del centro escolar, existe un exceso de cuestiones analíticas, en detrimento de creaciones originales o nuevas prácticas a partir de dichos procesos organizacionales. Es decir, no solo la estructura impide el aprendizaje organizacional, sino que además la característica del conocimiento intercambiado lo vuelve no benéfico organizacionalmente hablando.

  3. Soluciones Discretas para Sistemas Matriciales en Derivadas Parciales Hiperbolicos y Singulares

    CERN Document Server

    Salazar, Manuel J

    2011-01-01

    In this paper we study the construction of a discrete solution for a hyperbolic system of partial differentials of the strongly coupled type. In its construction, the discrete separation of matricial variable method was followed. Two separate equations in differences were obtained: a singular matricial and the other one a Sturm Liouville vectorial problem, which by the superposition principle yield a stable discrete solution.

  4. Membranes for hydrogen and fuel cell technology; Membranas para celula combustivel e separacao de hidrogenio

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Suzana Pereira [GKSS-Forschungszentrum, Geesthacht (Germany)]. E-mail: nunes@gkss.de

    2005-07-01

    Membranes for fuel cell were prepared using as polymer matrix sulfonated polyether ketones. New sulfonated copolymers (poly oxazoles, poly imides and poly ketones) were synthesized. Nano composites using zirconium oxide and phosphates, as well as modified silicates were obtained aiming the application on direct methanol fuel cell (DMFC). The performances of membranes containing fillers with different aspects (spherical, layers, tubular, networks) and surface modification (hydroxy, imidazole, acid oligomers) were compared. The effect of surface modification was much more pronounced than that of the aspect. A good balance of proton conductivity and methanol permeability was obtained with silicates modified with imidazole groups. Good performance in DMFC were obtained with membranes containing zirconium phosphate. Acid oligomers also led to particularly high conductivity values above 100 deg C. Polyimide membranes with H{sub 2}/CH{sub 4} larger than 100 were obtained. (author )

  5. Tumor cells diagnostic through fractal dimensions; Diagnostico de celulas tumorais atraves de dimensoes fractais

    Energy Technology Data Exchange (ETDEWEB)

    Timbo, Christiano dos Santos

    2004-07-01

    This method relies on the application of an algorithm for the quantitative and statistic differentiation of a sample of cells stricken by a certain kind of pathology and a sample of healthy cells. This differentiation is made by applying the principles of fractal dimension to digital images of the cells. The algorithm was developed using the the concepts of Object- Oriented Programming, resulting in a simple code, divided in 5 distinct procedures, and a user-friendly interface. To obtain the fractal dimension of the images of the cells, the program processes the image, extracting its border, and uses it to characterize the complexity of the form of the cell in a quantitative way. In order to validate the code, it was used a digitalized image found in an article by W. Bauer, developer of an analog method. The result showed a difference of 6% between the value obtained by Bauer and the value obtained the algorithm developed in this work. (author)

  6. Serigraphy materialization of bi facial solar cells; Metalizacao serigrafica de celulas solares bifaciais

    Energy Technology Data Exchange (ETDEWEB)

    Moehlecke, Adriano; Zanesco, Izete; Mallmann, Ana P.; Eberhardt, Dario; Pereira, Gabriel F. [Pontificia Univ. Catolica do Rio Grande do Sul, Porto Alegre, RS (Brazil). Centro Brasileiro para Desenvolvimento da Energia Solar Fotovoltaica - CB-Solar]. E-mail: moehleck@pucrs.br

    2006-07-01

    This paper presents the low cost metallization process, based on serigraphy, for the fabrication of bifacial solar cells, optimizing the metallic patches project and the solar cell considering the serigraphic pastes, projected and manufactured a metallization mask, and implanted a screen-printer.

  7. Anti tumor vaccination with hybrid dendritic-tumour cells; Vacinacao antitumoral com celulas hibridas dendriticas tumorais

    Energy Technology Data Exchange (ETDEWEB)

    Barbuto, Jose Alexandre M.; Neves, Andreia R.; Ensina, Luis Felipe C.; Anselmo, Luciene B. [Sao Paulo Univ., SP (Brazil). Inst. de Ciencias Biomedicas. Dept. de Imunologia; Leite, Katia R.M.; Buzaid, Antonio C.; Camara Lopes, Luiz H. [Hospital Sirio-Libanes, Sao Paulo, SP (Brazil)

    2005-09-01

    Dendritic cells are the most potent antigen-presenting cells, and the possibility of their use for cancer vaccination has renewed the interest in this therapeutic modality. Nevertheless, the ideal immunization protocol with these cells has not been described yet. In this paper we describe the preliminary results of a protocol using autologous tumor and allogeneic dendritic hybrid cell vaccination every 6 weeks, for metastatic melanoma and renal cell carcinoma (RCC) patients. Thirty-five patients were enrolled between March 2001 and March 2003. Though all patients included presented with large tumor burdens and progressive diseases, 71% of them experienced stability after vaccination, with durations up to 19 months. Among RCC patients 3/22 (14%) presented objective responses. The median time to progression was 4 months for melanoma and 5.7 months for RCC patients; no significant untoward effects were noted. Furthermore, immune function, as evaluated by cutaneous delayed-type hypersensitivity reactions to recall antigens and by peripheral blood proliferative responses to tumor-specific and nonspecific stimuli, presented a clear tendency to recover in vaccinated patients. These data indicate that dendritic cell-tumor cell hybrid vaccination affects the natural history of advanced cancer and provide support for its study in less advanced patients, who should, more likely, benefit even more from this approach. (author)

  8. Células progenitoras endoteliales y angiogénesis en la hemorragia intracerebral no traumática: investigación traslacional

    OpenAIRE

    Pías Peleteiro, Juan Manuel

    2015-01-01

    Antecedentes: La hemorragia intracerebral no traumática (HINT) constituye un grave problema de salud pública, con una incidencia anual de 10-30/100.000, que suma unos dos millones de los 15 millones de ictus anuales. Esto resulta en altas tasas de morbimortalidad en adultos. Constituye, por otra parte, el ictus con menos opciones terapéuticas. Desconocemos la relación entre la disfunción endotelial y la capacidad del endotelio para participar en la angiogénesis y mecanismos de reparación vasc...

  9. Avaliação da migração das células progenitoras após terapia da tendinite equina

    OpenAIRE

    P.G.G. Oliveira; A.M. Carvalho; A.L.M. Yamada; L. Maia; N.P.P. Freitas; M.J. Watanabe; F.C. Landim-Alvarenga; A.L.G. Alves

    2014-01-01

    A terapia celular vem sendo utilizada com resultados promissores no tratamento da tendinite equina, entretanto ainda existem dúvidas quanto à persistência e ao comportamento dessas células quando implantadas no local da lesão, e quanto à sua migração para outros focos inflamatórios. O objetivo deste estudo foi avaliar a marcação das células-tronco mesenquimais (CTMs) com nanocristal antes e após o implante em lesões tendíneas experimentais do tendão flexor digital superficial (TFDS) de equino...

  10. Simulation of limiting dilution technique in determination of immunocompetent cells frequency in irradiated cell cultures; Simulacao da tecnica de analise por limite de diluicao na determinacao da frequencia de celulas imunocompetentes em culturas contendo celulas irradiadas

    Energy Technology Data Exchange (ETDEWEB)

    Martini Filho, R.J.; Barlette, V.E.; Goes, E.G. [Centro Universitario Franciscano, Santa Maria, RS (Brazil); Covas, D.T.; Orellana, M. [Fundacao Hemocentro de Ribeirao Preto, SP (Brazil)

    2001-07-01

    Limiting dilution techniques (LDA) dose-response data have been used to detect immunocompetent T-Cells in microcultures. In this work, LDA frequencies estimates was obtained using {chi}2 minimization for irradiated cells in a range of 500 to 1,500 cGy. (author)

  11. Algunos apuntes sobre la culpa en la responsabilidad derivada de las prácticas comerciales restrictivas de la competencia

    Directory of Open Access Journals (Sweden)

    Carolina Salazar Holguín

    2013-12-01

    Full Text Available La protección de la competencia es un principio de la economía de mercado encaminado a la protección del interés público que se encuentra inmerso en el mercado, y su violación genera efectos negativos tanto en el mercado que se protege, como en el patrimonio de personas particulares. Mientras que con el daño al mercado se afecta el interés general y la legislación busca protegerlo a través de sanciones administrativas, con el daño privado se afectan intereses particulares cuya forma de proteger no es otra que la responsabilidad civil, pero que proviniendo de la violación de normas de orden público posee características particulares. Con el fin de establecer si surge responsabilidad civil de la violación de normas de competencia, se deben analizar los diferentes elementos de la responsabilidad, aunque con las particularidades de las normas de libre competencia que cuentan con una dimensión objetiva –encaminada a proteger el interés general– y una subjetiva –que protege el interés particu1lar–. Dentro de estos elementos se encuentra la culpa, frente a la cual se han expuesto diferentes posiciones que van desde considerarla probada con la violación de las normas de competencia, hasta afirmar que se trata de una responsabilidad objetiva. Tratándose de daños ocasionados por la realización de prácticas comerciales restrictivas, estamos ante un caso de responsabilidad por el hecho propio –actividad de los comerciantes–, que debe ser analizado bajo un régimen subjetivo de culpa probada, con la particularidad de que la violación de la norma de competencia, que es de orden público y encaminada, en su dimensión objetiva a proteger el interés general, trae ínsito el elemento culpa, siendo la única opción del demandado demostrar la existencia de una causal de exoneración o que incurrió en un error invencible.

  12. Las responsabilidades empresariales derivadas de la prevenci??n de riesgos laborales = Business responsibilities derived from labour risk prevention

    OpenAIRE

    Gorgojo Garc??a, Miguel ??ngel

    2015-01-01

    En las l??neas siguientes se hace un exhaustivo repaso de las responsabilidades exigibles al empresario en materia de seguridad y salud laboral, comenzando por la responsabilidad civil, en la que se analizar?? y distinguir?? su doble naturaleza: contractual o extracontractual. A continuaci??n se detallan los entresijos de la responsabilidad en materia de Seguridad Social, destinada a compensar al trabajador por los da??os acaecidos en el desempe??o de su trabajo, la cual se traduce en un Reca...

  13. Algunas aplicaciones del método de elementos finitos a problemas en derivadas parciales no lineales

    OpenAIRE

    Echevarría Líbano, Rosa

    1995-01-01

    "En la primera parte de la memoria se expone parte de un trabajo realizado en el marco del proyecto Hermes de investigación de la agencia espacial europea. en el se aborda la resolución numérica de las ecuaciones del modelo M.P.P. de turbulencia para fluj

  14. Aplicación del problema de momentos para resolver una ecuación en derivadas parciales

    OpenAIRE

    Vericat, Fernando; Pintarelli, María Beatriz

    2011-01-01

    Utilizando la transformada bidimensional de Laplace se transformará la ecuación (1) en un problema de momentos de Hausdorff bidimensional. Se encontrará una solución aproximada y se acotará el error de la solución estimada utilizando las técnicas sobre problema de momentos bidimensional. También se mostrará que (1) es equivalente a resolver una ecuación integral de Fredholm de primera especie.

  15. La huerta de Murcia como ejemplo de escorrentía derivada inscrita en llanura de crecida

    Directory of Open Access Journals (Sweden)

    Martín Lillo Carpio

    2000-01-01

    Full Text Available Se abordan en este trabajo las dificultades generalmente planteadas en la ocupación de las llanuras de crecida, así como los problemas de incremento del riesgo de inundación, provocados por la paulatina sobreelevación de los cauces fluviales. También se pone de manifiesto el esfuerzo realizado en estos casos por las poblaciones ribereñas, a fin de mantener invariable algún tramo del trazado del río, lo que da lugar a enclaves de actividades diferenciadas respecto a su entorno agrícola. El ejemplo de concomitancia propuesto, revela tanto la importancia origínea de la presa de derivación y red de cauces construidos, origen de la huerta, como del tramo fluvial encauzado origen de la ciudad de Murcia.

  16. Consecuencias conductuales derivadas del proceso atencional en el aula de aprendizaje: propuestas de detección

    OpenAIRE

    González Gómez, Carlota; Menchén Aparicio, Marina; Fernández Carrasco, Francisco; Sempere Tortosa, Mireia Luisa; García Fernández, José Manuel; Navarro Soria, Ignacio Javier; Vicent Juan, Maria; Gonzálvez Macià, Carolina

    2015-01-01

    Uno de los factores fundamentales a tener en cuenta en el proceso de aprendizaje es la atención, máxime si consideramos que se trata del primer paso que debe darse en todo proceso de aprendizaje. Derivado de una falta de atención, inatención o dificultad para mantenerla o focalizarla, pueden surgir otros problemas con frecuencia asociados a ellos, como son un bajo rendimiento, problemas de comprensión, inadecuado desarrollo de las competencias esperadas e incluso conductas asociadas que dific...

  17. Desigualdades territoriales en México derivadas del tratado de libre comercio de América del Norte

    Directory of Open Access Journals (Sweden)

    Javier Delgadillo Maclas

    2008-04-01

    Full Text Available La instrumentación del Tratado de Libre Comercio de América del Norte (TLCAN a partir del año 1994 consolidó una etapa de libe ral ización económica iniciada en México a partir de 1982. La sistemática operación del TLCAN en los distintos sectores de la economía (incorporados a este acuerdo comercial se vio al mismo tiempo acompañada de efectos territoriales favorables en algunos casos, y de dimensiones críticas para un número importante de regiones y estados que componen la federación mexicana. Después de 14 años de su inicio, en este trabajo se analizan los procesos de reestructuración espacial desde entonces generados, las disparidades regionales asociadas al nuevo escenario internacional, y se da cuenta de las relaciones económicas que contraponen a la etapa actual del modelo neoliberal imperante con aquellas otras formas tradicionales de organización excluidas y que aún mantienen en México buena proporción de espacios socialmente marginadosThe coming into force of the North American Free Trade Agreement (NAFTA from 1994 consolidated a phase of Mexican economic liberalization that had begun in 1982. The systematic operationalization of the NAFTA in different sectors of the economy (incorporated into this commercial agreement was also accompanied by favorable spatial impacts in some cases, and unfavorable impacts for a significant number of regions and states of the Mexican federation. Fourteen years on, this article analyzes the processes of spatial restructuring that have been generated, the regional disparities associated with the new international scenario, and explains the economic relations that run in opposition to the current stage of the dominant neoliberal model, which has excluded other traditional forms of organization and has kept many areas of Mexico in a condition of social marginalization

  18. Iglesia católica: vigencia de un sistema panóptico y estrategias derivadas del miedo

    OpenAIRE

    Arturo Navarro

    2012-01-01

    El trabajo presenta un análisis de las tensiones que se viven en el catolicismo mexicano, a partir de una relación de cercanía discreta entre la Iglesia y el Estado. Señala las estrategias que este modelo de relación genera, que derivan en lo que se identifica como sistema panóptico, que busca guiar todas las áreas de la vida, a partir de una pedagogía del miedo. Se reconoce que el pluralismo religioso es un elemento para el discernimiento en la institución católica.

  19. La responsabilidad bancaria derivada de las operaciones de crédito en el derecho francés

    Directory of Open Access Journals (Sweden)

    Mónica Rodríguez González

    2011-07-01

    Full Text Available El recurso al préstamo bancario es de vital importancia para la constitución y buen funcionamiento de las empresas, especialmente de las de pequeña y mediana talla. Esta relación de dependencia entre empresas y bancos es aun mayor cuando la empresa se ve obligada a entrar en un régimen de insolvencia. En Francia existía un régimen de responsabilidad bancaria por daños ocurridos en el ejercicio de la actividad crediticia. Las hipótesis eran: a rechazo del crédito, b ruptura abusiva de la relación crediticia, c concesión de un crédito ruinoso y, d sostenimiento abusivo de la relación crediticia. Pero una ley de 2005 vino a desmontar este régimen de responsabilidad, estableciendo un principio de irresponsabilidad, con solo tres excepciones. La eficacia de la ley, sin embargo, puede cuestionarse.

  20. La responsabilidad bancaria derivada de las operaciones de crédito en el derecho francés

    Directory of Open Access Journals (Sweden)

    Mónica Rodríguez González

    2011-06-01

    Full Text Available El recurso al préstamo bancario es de vital importancia para la constitución y buen funcionamiento de las empresas, especialmente de las de pequeña y mediana talla. Esta relación de dependencia entre empresas y bancos es aun mayor cuando la empresa se ve obligada a entrar en un régimen de insolvencia. En Francia existía un régimen de responsabilidad bancaria por daños ocurridos en el ejercicio de la actividad crediticia. Las hipótesis eran: a rechazo del crédito, b ruptura abusiva de la relación crediticia, c concesión de un crédito ruinoso y, d sostenimiento abusivo de la relación crediticia. Pero una ley de 2005 vino a desmontar este régimen de responsabilidad, estableciendo un principio de irresponsabilidad, con solo tres excepciones. La eficacia de la ley, sin embargo, puede cuestionarse.

  1. LA ESTRUCTURA ESCOLAR INHIBIDORA DEL APRENDIZAJE ORGANIZACIONAL: EXPERIENCIA DERIVADA DE CASO (SCHOOL STRUCTURE INHIBITING ORGANIZATIONAL LEARNING: EXPERIENCE FROM A CASE

    Directory of Open Access Journals (Sweden)

    Simonetta David

    2010-04-01

    Full Text Available Resumen:El presente artículo describe resultados y conclusiones de una investigación realizada en un centro escolar de nivel medio llamado Instituto Brigadier General Martín Rodríguez, de financiamiento público y gestión privada, de la ciudad de Tandil, provincia de Buenos Aires, República Argentina. En este artículo se ha abordado la problemática de la estructura del centro escolar y su impacto en la gestión del conocimiento y la generación de aprendizaje organizacional en la escuela. Se investigó distinta bibliografía referida a la estructura organizacional, la gestión del conocimiento, las teorías denominadas principios, disciplinas, o procesos de aprendizaje organizacional, y organización y gestión de centros escolares. Se ha planteado a partir de allí el modelo de observación que caracteriza la dinámica y evolución del aprendizaje organizacional y sus efectos. Directivos, Docentes, Personal de apoyo, Alumnos aportaron sus opiniones para este trabajo. Bajo este modelo de abordaje, se evidencian en el caso planteado características estructurales predominantemente inhibidoras de los procesos de aprendizaje organizacional. Respecto de los conocimientos tratados e intercambiados entre personas del centro escolar, existe un exceso de cuestiones analíticas, en detrimento de creaciones originales o nuevas prácticas a partir de dichos procesos organizacionales. Es decir, no solo la estructura impide el aprendizaje organizacional, sino que además la característica del conocimiento intercambiado lo vuelve no benéfico organizacionalmente hablando.Abstract:The following paper describes results and conclusions of a research carried out in The Instituto Brigadier General Martín Rodríguez, a public financing and private management high school, located in Tandil city, Buenos Aires province, Argentina. The problem of the school structure has been addressed in this paper, as well as its impact on knowledge management and the production of organizational learning in the school. It has been gathered different literature related to the organizational structure, the knowledge management, theories named principles, disciplines, or processes of organizational learning, as well as organization and management of schools; based on such literature, the observation model (which characterizes the dynamics and evolution of organizational learning and its effects has been presented. Faculty Board, Teachers, Non-Teaching staff, and students gave their opinions for this paper. According to this approaching model, the structural features, which inhibit the organizational learning processes in a prevailing way, are shown in this study case. Regarding the knowledge discussed and exchanged among people from the school, there is an excess of analytical issues in prejudice of original inventions or new practices based on such organizational processes; in other words, the organizational learning is affected not only by the structure, but also by the exchanged knowledge feature which, in turn, becomes such learning negative, organizationally speaking.

  2. Condiciones metodológicas derivadas del análisis comunicacional de la enseñanza

    Directory of Open Access Journals (Sweden)

    Miguel Ángel ZABALZA BERAZA

    2009-11-01

    Full Text Available En otros trabajos anteriores (Zabalza 1983, 1984 he abordado la temática del análisis de la enseñanza desde la perspectiva de la comunicación didáctica. En dichos trabajos creo que queda suficientemente justificada la fundamentación teórica que permite abordar la realidad «enseñanza» como un «evento comunicacional». Sin embargo siguen persistiendo numerosas dificultuades para desarrollar metodológicamente esos supuestos conceptuales de partida y articular proyectos o modelos de investigación de la enseñanza, a nivel comunicacional, que sean congruentes con ellos. Esa dificultad, que estamos sufriendo a diario nosotros mismos a la hora de planear una tesina, una tesis o cualquier otro tipo de investigaciones sobre este campo, me ha servido de acicate para desarrollar las reflexiones que a continuación expongo.

  3. Resistencia a cisplatino en celulas de carcinoma de ovario: cuantificación de roturas de ADN

    OpenAIRE

    Arcilla Aller, Francisco

    2013-01-01

    Estudio de las diferencias entre dos líneas celulares emparentadas, A2780 y A2780cis(resistente a cisplatino). Se evaluaron las diferencias en respuesta al daño en ADN, inducido por cisplatino, entre ambas líneas mediante el ensayo del cometa.

  4. Perovskites synthesis for solid oxide fuel cells; Sintese de perovsquitas para celulas a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Sibelle F.C.X.; Melo, Dulce M.A.; Pimentel, Patricia M.; Melo, Marcus A. Freitas; Martinelli, Daniele M.H. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Quimica]. E-mail: sibelle.cunha@gmail

    2008-07-01

    This work aims to study on the obtaining powders of lanthanum manganite oxides with partial substitution of La with strontium at 20% for the application as a cathode for solid oxide fuel cell, through a route of synthesis that are similar to the Pechini method, in which gelatin replaces the ethylene glycol as polymerization agent. The method highlights itself due to its simplicity, low cost and capability to obtain crystalline powders with the high purity and good stoichiometric control. The perovskite obtained were characterized by thermogravimetric analysis, X ray diffraction, electronic scanning microscopy and the superficial area by BET method. The deposition of the perovskite on electrolyte/anode system was done through the spin coating technique. The methodology used for the perovskite synthesis was very efficient, considering a monophasic material was obtained and with characteristics that were proper to the application as electrode to solid oxide fuel cells. (author)

  5. Development of solid oxide fuel cells (SOFC); Desenvolvimento de celulas a combustivel do tipo oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Souza, F.M.B. de; Carvalho, L.F.V. de; Alencar, M.G de; Boaventura, J.S. [Universidade Federal da Bahia (DFQ/UFBA), Salvador, BA (Brazil). Dept de Fisico-Quimica. Grupo de energia e Ciencias dos Materiais], e-mail: bventura@ufba.br

    2008-07-01

    The most promising technology for generating electric power, with reduced environmental impact, is the fuel cell. This technology is virtually non-polluting and the fuel supplies can be renewable. Therefore is necessary to study the technique of preparing the entire anode / electrolyte / cathode to optimize its operation. There are still major challenges to making the SOFC economically viable. The key is the improvement of manufacturing of its components and use of materials that can simultaneously reduce costs and reduce the temperature of operation. Among the properties of the cell, was shown the dependence of the efficiency of the device on the properties of the electrolyte, particularly its thickness. The mixture of YSZ with GDC in the composition of the anode and electrolyte aims to obtain a material with greater ionic conductivity. After sintering the cell was characterized by scanning electron microscopy (SEM). (author)

  6. Studies of water electrolysis in polymeric membrane cells; Estudos de eletrolise aquosa em celulas de membrana polimerica

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira-Silva, M.A.; Linardi, M.; Saliba-Silva, A.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Celulas a Combustivel e Hidrogenio

    2010-07-01

    Hydrogen represents great opportunity to be a substitute for fossil fuels in the future. Water as a renewable source of hydrogen is of great interest, since it is abundant and can decompose, producing only pure H{sub 2} and O{sub 2}. This decomposition of water can be accomplished by processes such as electrolysis, thermal decomposition and thermochemical cycles. The membrane electrolysis has been proposed as a viable process for hydrogen production using thermal and electrical energy derived from nuclear energy or any renewable source like solar energy. In this work, within the context of optimization of the electrolysis process, it is intended to develop a mathematical model that can simulate and assist in parameterization of the electrolysis performed by polymer membrane electrolytic cell. The experimental process to produce hydrogen via the cell membrane, aims to optimize the amount of gas produced using renewable energy with non-carbogenic causing no harm by producing gases deleterious to the environment. (author)

  7. INTEGRACION DE UNA CELULA FLEXIBLE DE MECANIZADO, DE TIPO DOCENTE INTEGRATION OF A EDUCATIONAL FLEXIBLE MANUFACTURING CELL

    OpenAIRE

    Abraham Farias F; Luis Moraga G; Ambrosio Martinich L

    2007-01-01

    Este trabajo trata sobre la integración de una célula flexible de mecanizado de tipo docente, compuesta por una fresadora didáctica CNC, marca Denford, un brazo robótico articulado de seis ejes, modelo Scorbot -ER Vplus  y un riel deslizante; todos pertenecientes al Laboratorio de Manufactura Integrada por Computador, de la Escuela de Ingeniería Mecánica de la Universidad de Talca. Las tareas que realiza esta célula flexible son controladas por un PC director  a través de un  programa, utiliz...

  8. Intraabdominal desmoplastic small round cell tumor - case report; Tumor de pequenas celulas redondas desmoplasico intra-abdominal - relato de caso

    Energy Technology Data Exchange (ETDEWEB)

    Westphalen, Antonio Carlos Anderson; Ferreira, Jose Hamilton Pinheiro [Hospital Moinhos de Vento, Porto Alegre, RS (Brazil). Moinhos Centro de Imagem]. E-mail: cpostal@zaz.com.br; Daudt, Alexander Welaussen [Centro de Oncologia Radioterapica do Rio Grande do Sul, Porto Alegre, RS (Brazil); Gaiger, Ana Maria [Pontificia Univ. Catolica do Rio Grande do Sul, Porto Alegre, RS (Brazil). Faculdade de Medicina. Dept. de Patologia

    2001-10-01

    The authors report a case of intraabdominal desmoplastic small round cell tumor in a 21-year-old male patient who presented with abdominal pain, right lower limb thrombosis and obstructive loss of renal function. Initial investigation showed a large lobulated intraabdominal soft tissue mass with internal cystic cavities, located posteriorly to the bladder and causing obstruction of ureteral flow, compression of the right iliac vein and partial occlusion of the rectum. Involvement of intraperitoneal and retroperitoneal nodes was also seen. Ultrasound, computed tomography and magnetic resonance imaging findings, as well as surgical and histopathology macroscopical, microscopical and immunohistochemistry findings are described. (author)

  9. Establecimiento de un cultivo de celulas en suspensión de Eucalyptus cinérea

    Directory of Open Access Journals (Sweden)

    Orozco Sáncnez Fernando

    2002-06-01

    Full Text Available Se desarrolla un protocolo para la obtención y establecimiento de suspensiones celulares de E. cinerea. La concentración de las hormonas 2,4 D Y BAP tienen un efecto significativo en la formación de callos friables de E. cinerea, obteniendo una respuesta periódica en la formación de callos friables con respecto a la concentración de las hormonas. Puede obtenerse hasta un 90% de formación de callos friables con varias combinaciones hormonales; primero, con concentraciones alrededor de 3,0 mg/L de 2,4 D Y 1,0 mg/L de BAp, y segundo, alrededor de 6,0 mg/L de 2,4 D Y1,0 mg/L de BAP. A partir de los callos anteriores, se obtienen suspensiones celulares con un activo crecimiento celular, con tiempos de duplicación entre cuatro y siete días, y alcanzando densidades celulares de 15 g células secas/L. Las suspensiones de E. cinerea ofrecen una herramienta importante para la propagación de esta especie vía embriogénesis somática, estudio de biorreactores, producción de metabolitos secundarios y procesos de biotransformación.

  10. Systems of three generation using fuel cells; Sistemas de trigeracao com o uso de celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    San Martin Diaz, Jose Ignacio; Aperribay Maiztegui, Victor; San Martin Diaz, Jose Javier [Escuela Universitaria de Ingenieria Tecnica Industrial de Eibar, Guipuzcoa, Pais Vasco (Spain); Zamora Belver, Inmaculada; Eguia Lopez, Pablo [Escuela Tecnica Superior de Ingenieria de Bilbao (Spain)

    2010-10-15

    The three generation includes production processes and simultaneous use oe electric power, heat and cold from a fuel source providing global high energy efficiency, reduction of emission of gases in the atmosphere, losses of investments, and more reliability in the supply. This paper approaches the use of fuel cells for three generation, and presents different subsystems of generation with the main characteristics and applications. (author)

  11. Evaluation of sulphonated polycarbonate membranes for fuel cells; Avaliacao de membranas de policarbonato sulfonado para celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Isabela M.M.; Gomes, Ana C.; Pessan, Luiz A. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Engenharia de Materiais], e-mail: isabelamuglia@gmail.com; Paranhos, Caio [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2011-07-01

    Fuel cells based on ion conducting polymer membranes offer an alternative for the conventional energetic matrices. Among many advantages of this system, we can mention the reduction on the emission of pollutants, high efficiency and simplicity. This work presents the modification of polycarbonate by sulfonation reaction using acetyl sulfate, in order to increase the conductor ionic character of the membranes used as electrolytes for hydrogen fuel cells. The sulfonated polycarbonate membranes were obtained by casting and then characterized by Fourier transform infrared spectroscopy, water vapor transmission, differential scanning calorimetry, thermogravimetric analysis and viscosimetry. (author)

  12. Interaccion de promastigotes de Leishmania donovani con celulas de exudado peritonial de ratones mediante la influencia de la quimotripsina

    Directory of Open Access Journals (Sweden)

    Lucila Arcay

    1986-06-01

    Full Text Available Se hace un estudio de la interacción de promastigotes de Leishmania donovani con células de exudado peritoneal de ratón (c e p mediante la influencia de la quimotripsina. La adhesión de los promastigotes a las c e p fue terminal y marginal, y en observaciones hechas a partir de los 10 minutos de enfrentamiento, esta adhesión fue nula hasta los 30 minutos en el grupo tratado, y sólo a las das horas hubo un pequeño incremento (2.4% con respecto al control. Se observa marcada disminución en todos los parámetro medidos, tales como enlace, penetración, multiplicación intracelular, división de formas flageladas, en el grupo tratado. La quimotripsina favorece la formación de formas intermedias flageladas, heciendose el parásito piriforme y esférico, apareciendo una forma aberrante de extremo anterior cilindrico que semeja a una forma coanoflagelada. Se sospecha que la enzima reduce efectivamente fragmentos proteicos o péptidos, los cuales pueden haber sido tan pequeños como para esconder a otros ligandos relacionados con la adhesión macrófago-parásito.

  13. Experimental analysis of a PEM fuel cell 15 W; Analise experimental de uma celula a combustivel PEM 15W

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Raphael Guardini; Bazzo, Edson [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Combustao e Engenharia de Sistemas Termicos], e-mail: miyake@labcet.ufsc.br, e-mail: ebazzo@emc.ufsc.br

    2006-07-01

    Fuel cells have been considered a promising alternative for electric energy generation. In order to contribute with the development of this technology, a PEM fuel cell was installed and new experiments were carried out at LabCET (Laboratory of Combustion and Thermal System Engineering). Previous results have shown polarization curves identifying the need of rigorous controlling of humidification temperature of the fuel cell. In this paper, new results were carried out considering the use of a fan connected to the fuel cell and possible degradation in the electrolyte, after a relative long time operation. New polarization curves were plotted for comparison with previous results. (author)

  14. INTEGRACION DE UNA CELULA FLEXIBLE DE MECANIZADO, DE TIPO DOCENTE INTEGRATION OF A EDUCATIONAL FLEXIBLE MANUFACTURING CELL

    Directory of Open Access Journals (Sweden)

    Abraham Farias F

    2007-04-01

    Full Text Available Este trabajo trata sobre la integración de una célula flexible de mecanizado de tipo docente, compuesta por una fresadora didáctica CNC, marca Denford, un brazo robótico articulado de seis ejes, modelo Scorbot -ER Vplus  y un riel deslizante; todos pertenecientes al Laboratorio de Manufactura Integrada por Computador, de la Escuela de Ingeniería Mecánica de la Universidad de Talca. Las tareas que realiza esta célula flexible son controladas por un PC director  a través de un  programa, utilizando el software y el propio control del robot y su objetivo es realizar el ciclo de carga y descarga de un  trozo de material de 65×65×40 mm. (madera y su posterior mecanización. El problema de comunicación entre los equipos involucrados y la fresadora CNC fue resuelto en cuanto su diseño "stand alone" no contemplaba la integración con otros equipos. Por otro lado, se agregaron algunos sistemas electroneumáticos para que la operación fuera automática, como los de sujeción de piezas y la apertura y cierre de puertas. Con esta célula flexible de mecanizado de tipo docente, la facultad de Ingeniería cuenta con una plataforma básica, a la que se puede adicionar otras funciones, como por ejemplo, dotarla de un sistema automático de alimentación de piezas, de un sistema de visión digital para dar más autonomía al robot, incorporar un torno CNC y  generar un programa para administrar las órdenes de trabajo.This paper describes the integration of an educational flexible manufacturing cell, consisting of a Denford CNC mill with six axes, and a Scorbot - ER Vplus robotic arm that slides along a rail. This equipment is located at the Computer Integrated Manufacture Laboratory, at the School of Mechanical Engineering at Universidad de Talca. The flexible cell is controlled by software in a PC that interacts with the software in the robotic arm. The specific tasks described in this paper are loading and unloading a wooden piece (640×65×40 and to mechanizing the piece. One difficulty solved in this work was the potential communication problem between the control equipment CNC mill, since the original, stand-alone design did not admit integration with other controllers. In addition, electro-pneumatic devices were added to permit automatic operation of the system in situations such as gripping the piece and opening the mill door. This basic platform gives the possibility of adding new functions and equipment, such as automatic loading of work pieces, digital reading systems, a CNC lathe and a work order information system.

  15. Experimental study of proton exchange membrane fuel cell; Estudo experimental de uma celula a combustivel de membrana polimerica

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, Luis Evelio Garcia; Oliveira, Amir Antonio Martins [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica], e-mail: evelio@labcet.ufsc.br, e-mail: amirol@emc.ufsc.br

    2006-07-01

    Here we present a thermodynamic and chemical kinetic analysis of the methane steam reforming for production of 5 kw of electrical power in a PEM fuel cell. The equilibrium analysis is based on the method of element potentials to find the state of minimum Gibbs free energy for the system and provides the equilibrium concentration of the reforming products. The objective of this analysis is to obtain the range of reforming temperature, pressure and steam-methane molar ratio that results in maximum hydrogen production subjected to low carbon monoxide production and negligible coke formation. The thermal analysis provides the heat transfer rates associated with the individual processes of steam production, gas-phase superheating and reforming necessary to produce 5 kw of electrical power in a PEM fuel cell and allows for the calculation of thermal efficiencies. Then, the chemical reaction pathways for hydrogen production in steam reforming are discussed and the available chemical, adsorption and equilibrium constants are analyzed in terms of thermodynamic consistency. This analysis provides the framework for the reactor sizing and for establishing the adequate operation conditions. (author)

  16. Fuel cells cathode with multiple catalysis and electrocapillary convection; Catodo de celula a combustivel com catalise multipla e conveccao eletrocapilar

    Energy Technology Data Exchange (ETDEWEB)

    Bambace, Luis Antonio Waack; Nishimori, Miriam; Ramos, Fernando Manuel [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil)], e-mail: bambace@dem.inpe.br; Bastos Netto, Demetrio [Instituto Nacional de Pesquisas Espaciais (INPE), Cachoeira Paulista, SP (Brazil)

    2004-07-01

    This paper discusses a mathematical model for the chemical reactions and liquid phase flow processes occurring in a fuel cell cathode through non homogeneous catalysis carried by gold and Prussian Blue. The gold is applied inside the porous walls of micro-tubes, which may be obtained through several methods. The wall porosity ranging from 7 to 30% ensures gas exchange between the interior of a micro-tube and its exterior where gas flow takes place. The Prussian Blue consists of a thin porous layer located between the selective membrane and the micro-tube system, with void fraction in the 70 to 80% range. A porous electricity conducting carbide flux collector is placed between the tube system and the bipolar plates. The system return tubes possess a diameter much larger than one of the micro-tubes. The electric potential differences generated by the ionic currents in the system and its asymmetrical shape are used to generate electrocapillary flows, which are related with the surface tension changes with local potential. The hydrogen peroxide concentration and its transport to the Prussian Blue layer, and the oxygen transport inside the reactive tubular system are analyzed in this work. (author)

  17. IGF-II Y LA GONADOTROPINA CORIONICA REGULAN LA PROLIFERACION, MIGRACION E INVASION DE CELULAS DE TROFOBLASTO HUMANO.

    Directory of Open Access Journals (Sweden)

    Umana-Perez Adriana

    2011-04-01

    Full Text Available Son conocidas las propiedades del factor de crecimiento similar a la insulina IGF-II y de la hormona Gonadotropina Coriónica (hCG en la implantación y migración trofoblástica, sin embargo los mecanismos a través de los cuales ejercen sus efectos no han sido identificados. El objetivo de este estudio fue establecer la interacción potencial entre los efectos funcionales de hCG y el IGF-II en la regulación de la proliferación, migración e invasión trofoblástica. Utilizando la línea celular HTR-8/SVneo de trofoblasto extravelloso se pudo demostrar que tanto IGF-II como hCG estimulan la proliferación y migración celular sin observarse efectos aditivos en sus acciones, lo cual es indicativo independencia de sus mecanismos. En contraste, la capacidad invasiva del trofoblasto fue regulada por IGF-II y hCG, dando como resultado efectos aditivos o un potencial sinergismo entre las dos hormonas. En conclusión, nuestros resultados muestran la existencia de interacciones entre las acciones biológicas de IGF-II y hCG en la regulación de la capacidad invasiva de células trofoblásticas y contribuyen al entendimiento de la biología del trofoblasto y de su malignización.

  18. Photostability Assessment in Amorphous-Silicon Solar Cells; Determinacion de la Fotoestabilidad en Celulas Solares de Silicio Amorfo

    Energy Technology Data Exchange (ETDEWEB)

    Gandia, J. J.; Carabe, J.; Fabero, F.; Jimenez, R.; Rivero, J. M. [Ciemat, Madrid (Spain)

    2000-07-01

    The present status of amorphous-silicon-solar-cell research and development at CIEMAT requires the possibility to characterise the devices prepared from the point of view of their stability against sunlight exposure. Therefore a set of tools providing such a capacity has been developed. Together with an introduction to photovoltaic applications of amorphous silicon and to the photodegradation problem, the present work describes the process of setting up these tools. An indoor controlled-photodegradation facility has been designed and built, and a procedure has been developed for the measurement of J-V characteristics in well established conditions. This method is suitable for a kinds of solar cells, even for those for which no model is still available. The photodegradation and characterisation of some cells has allowed to validate both the new testing facility and method. (Author) 14 refs.

  19. Performance of direct ethanol and methanol fuel cells as function of alcohol concentration applied to the anode of those cells; Desempenho de celulas a combustivel com alimentacao direta de etanol (CCADE) e celulas a combustivel com alimentacao direta de metanol (CCADM) em funcao da concentracao do alcool aplicado ao anodo destas celulas

    Energy Technology Data Exchange (ETDEWEB)

    Belchor, P.M.; Forte, M.M.C. [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Correa, J.P.; Kuhn, C.K.; Carpenter, D. [FURB -Fundacao Universidade Regional de Blumenau, SC (Brazil)

    2010-07-01

    This paper aimed to compare the performance of a CCADE and a CCADM as function of diminishing of concentration of alcohol applied top the anode of each cell. As result, reaching a diminishing the concentration of each alcohol through the mix of each one with the deionized water, one obtained a improved humidification and sensible reduction of the permeability of cationic membrane, generating a gain of performance of the functioning both cells. (author)

  20. Fuel cell: new electrocatalysts for SOFC (Solid Oxide Fuel Cells) anodes and regulation between cell performance and catalytic activity; Celula a combustivel: novos eletrocatalisadores para anodos de SOFC (Celulas a Combustivel de Oxido Solido) e correlacao entre desempenho da celula e atividade catalitica

    Energy Technology Data Exchange (ETDEWEB)

    Boaventura, Jaime S.; Aguiar, Aurinete B.; Brandao, Soraia T. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil); Frank, Maria Helena Troise; Campos, Michel F. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    Electro-catalysts were prepared using new routes. Chemical Ultrasound Deposition (CUD) method: aqueous solution of nickel nitrate and citric acid was ultrasound vaporized and deposited on heated Ytria-stabilized Zirconia (YSZ). Resin impregnation (IPR) method: nickel oxide and YSZ were mixed, added to phenolic resins, precipitated in acidic water and milled. Wet impregnation method (IMP) was used for comparison: YSZ and an aqueous solution of nickel nitrate and citric acid were mixed, followed by evaporation, drying and calcination. The catalysts were evaluated for methane steam reforming in a quartz reactor. The reactions were conducted for one hour with no significant catalytic activity loss. In reactions with 100 mg of catalyst and a mixture consisting of methane and steam (3:1), IPR catalyst showed activity higher and better stability than those by IMP. On other tests, the reform was conducted with 100 mg of catalyst and methane to steam of 10. The IPR catalyst activity was so high that the reaction approached equilibrium conditions. Anode/electrolyte/cathode units (A/E/C) were prepared with the above catalysts as follows: the anode was a catalyst porous layer; the electrolyte an YSZ dense layer; and the cathode an LSM porous layer; graphite powder formed the material porosity. The two first layers, in powder form, were put in a stainless steel cast, pressed to 4000 bars and sinterized. The cathode layer was subsequently added using tape-casting techniques followed by sintering. A/E/C units showed 40% linear contraction and porosity higher than 20%. For fuel cell tests, A/E/C was mounted in alumina plates with platinum current collectors. Unitary SOF cells were loaded with hydrogen diluted in nitrogen showing opened circuit voltage from circa 700 mV, for the CUD anode, to 350 mV, for the IPR anode. The unitary SOFC was loaded with methane for 15 minutes or longer, with no noticeable voltage loss. At 1300 K the SOFC made with IPR or IMP catalysts showed opened current voltages close to 500 mV, while CUD SOFC measured less approximately 300 mV. In conclusion, the SOFC opened current voltage might be related to the reforming activity of the electro-catalyst used as the anode. (author)

  1. Program for the radiological protection of the embryos-fetuses due to the medical exposure of him mother; Programa para la proteccion radiologica del embrio-feto debido a la exposicion medica de su progenitora

    Energy Technology Data Exchange (ETDEWEB)

    Lopez B, G.M.; Martinez G, A.; Cardenas H, J.; Gonzalez R, N.; Valdes R, M.; Zaldivar H, W. [CPHR, Calle 20 No. 4113 e/41 y 47, Playa C.P. 11300, La Habana (Cuba)]. e-mail: gladys@cphr.edu.cu

    2006-07-01

    In the last years the organizations in charge of the regulation in matter of radiological protection, its have adopted measures to minimize the risks derived of the medical exposures, paying special attention to those that involve women in age of procreation, gestating and in period of lactation, because the embryo - fetus and the newborn babies ones are very vulnerable to the risks of the ionizing radiations, which can end up producing them multiple effects of variable severity. In Cuba, a Maternal-children program that includes the genetic advice to the pregnant woman from the medical point of view exists but didn't so the evaluation of the radiological risk; which is only carried out by the Medical Surveillance Service of the Protection and Hygiene of the Radiations Center (CPHR), without that mediates an official link among both parts and whose existence is only known by a reduced group of professionals of the health and of specialists in Radiological Protection. On the other hand is not established a strategy at national level for the differentiated information and systematic in these topics that it contributes to the control of the exposures of the embryo fetus and the breast-fed baby. Keeping in mind the above-mentioned the specialists of the CPHR have elaborated a proposal of national program for the radiological protection of the embryo- fetus due to the medical exposure of its progenitor. In the same one it is settles down the interrelation between work groups and multidisciplinary institutions to achieve the detection, communication and consultant ship of the cases of exposure to the fetus or breast-fed baby that happen in the country and at the same time include the training so much of the professionals of the health like of the public in general. Presently work the program and the elements that conform it among those that are, the on-line system developed for the automation of the medical dosimetric evaluation, the technician-methodological documents on this topic as well as the informative and instructive tools directed to the professionals and the public in general are described. (Author)

  2. Caracterización de un modelo organotípico de cultivos de neuronas corticales de humano derivadas de trauma craneoencefálico

    Directory of Open Access Journals (Sweden)

    David Riascos

    2008-09-01

    Full Text Available Introducción: El trauma craneoencefálico (TEC es un problema de salud global que puede generar en los pacientes que lo padecen, muerte, discapacidad y/o alteraciones psiquiátricas con gran impacto sobre su desempeño posterior y sobre su ámbito familiar. En los últimos años se ha avanzado en el conocimiento de los mecanismos fisiopatológicos que subyacen al TCE. Sin embargo, esto no está completamente entendido, como tampoco hay claridad sobre los mecanismos de neuroprotección. Por esta razón cada vez más se buscan modelos que permitan aproximarse al estudio de este síndrome y de esta manera aproximarse a la neuroprotección.Objetivo: Caracterizar un modelo de cultivo organotípico de neuronas corticales humanas obtenidas de personas que sufrieron TCE y a las cuales se les practicó remoción de la contusión.Metodología: Se utilizó tejido cortical humano procedente de 4 individuos que sufrieron TCE y a los cuales se les removió la contusión. Se obtuvieron tajadas de corteza cerebral de 1,500-2,000 mm, las cuales se mantuvieron en un flujo continuo de LCRa a 2 ml/min y una mezcla gaseosa de O2 al 95% y CO2 al 5% con burbujeo permanente durante 2, 8 y 14 horas. Se tomó como tiempo cero el momento de obtención de la muestra. Después de cada tiempo se tomaron las tajadas, se cortaron en un vibrátomo de medio líquido a 50 mm y se procesaron inmunohistoquímicamente con los marcadores neuronales de degeneración NeuN y MAP2.Resultados: Los resultados indican que las muestras de corteza cerebral se pudieron mantener con cierto grado de integridad celular y laminar hasta las 2 horas de cultivo. Se observó que a partir de este tiempo se inicia un proceso de alteración de la citoarquitectura neuronal y laminar, determinada por la pérdida y alteración de la inmunorreactividad a los marcadores NeuN y MAP2. Además se encontró que hay vulnerabilidad celular que compromete en mayor medida a las neuronas localizadas en las láminas corticales III y V.Conclusiones: Se pudo caracterizar el modelo organotípico de cultivo de neuronas corticales humanas que determinó integridad neuronal y organización laminar clara hasta las 2 horas de evolución, lo cual permitiría la utilización de fármacos neuroprotectores durante este período. Se encontró vulnerabilidad laminar preferencialmente para las capas corticales III y V. El modelo dejó establecer la evolución temporal de las neuronas de la zona contusa.

  3. M??todos topol??gicos y variacionales en el estudio de soluciones de ecuaciones en derivadas parciales con una no -linealidad asim??trica

    OpenAIRE

    Villegas Barranco, Salvador

    1996-01-01

    La memoria esta dedicada al estudio de una clase de problemas de contorno el??pticos que surgen como modelos estacionarios de procesos de difusi??n.En concreto se estudian problemas referentes al operador laplaciano en dominios acotados con condiciones de frontera de tipo Dirichlet o Neumann.la forma de estudiar dichos problemas el??pticos es la propia del an??lisis funcional no-lineal, transformando dicho problema en una ecuaci??n funcional planteada en un espacio adecuado de funciones con d...

  4. Detección de aneurisma de la aorta abdominal en una población derivada para ecocardiografía transtorácica

    Directory of Open Access Journals (Sweden)

    Clotilde S. Berensztein

    2006-01-01

    Full Text Available Se evaluó: 1 la factibilidad de realizar una ecografía limitada a la aorta abdominal en pacientes a quienes se indica un ecocardiograma transtorácico, 2 las variables clínicas y ecocardiográficas que se correlacionan con el diámetro de la aorta abdominal, 3 la prevalencia de aneurisma de la aorta abdominal (AAA y 4 los factores de riesgo clínicos para AAA. Se evaluaron prospectivamente 280 pacientes consecutivos (media de edad: 68, rango 18 a 93 años, 118 de sexo masculino [42%]. Se verificó que: 1 el examen ecográfico de la aorta abdominal es factible en la mayoría de los pacientes (95,36% [IC 95% 92,88-97,84%], 2 el diámetro de la aorta abdominal se correlaciona con el sexo masculino, la edad, los antecedentes personales de enfermedad vascular periférica y los antecedentes de familiares de primer grado con AAA; también se correlaciona con el diámetro de la raíz aórtica (RA y con el grosor parietal relativo (GPR, 3 existe una prevalencia alta de AAA en la población estudiada (4,49% [IC 95% 1,99-7,00%], particularmente en los varones = 65 años (12,33% [IC 95% 4,60-20,05%] y 4 el sexo masculino, la hipertensión arterial, la dislipemia, el tabaquismo, la diabetes, los antecedentes personales de cardiopatía isquémica o de vasculopatía periférica y los antecedentes de familiares de primer grado con AAA son factores de riesgo para AAA. En conclusión, estaría justificada la realización de una ecografía abdominal como extensión de la ecocardiografía transtorácica en varones = 65 años, en particular si coexisten otros factores de riesgo para AAA.

  5. El concepto de cohesión territorial: escalas de aplicación, sistemas de medición y políticas derivadas

    OpenAIRE

    Pita López, María Fernanda; Fernández Tabales, Alfonso; Pedregal Mateos, Belén; Rodríguez Mateos, Juan Carlos; Zoido Naranjo, Florencio

    2009-01-01

    El concepto de cohesión territorial ha ido cobrando fuerza durante la última década como una de las expresiones más citadas en el ámbito temático de las políticas territoriales. Sin embargo, hasta fechas muy recientes ha adolecido de un escaso nivel de concreción, tanto teórica como práctica. Este texto se propone avanzar en dicha concreción, abordando las cuestiones clave del concepto de cohesión territorial en Europa, en cuanto a su definición; escala y ámbito de actuación; planteamiento...

  6. Una perspectiva de los problemas éticos derivada de la investigación biológica: los avatares del evolucionismo

    Directory of Open Access Journals (Sweden)

    Castrodeza, Carlos

    1999-02-01

    Full Text Available Not available.En la ciencia actual, el comportamiento ético es una práctica asumida. Es más, la ética como dimensión axiológica del conocimiento está relacionada con otros valores que le colocan al hombre en la cúspide de los seres vivos, confiriéndole así un derecho de uso sobre toda otra forma de vida. Ahora bien, dichos valores son cuestionables en cuanto que no son compatibles con el conocimiento biológico actual. Dicha falta de coherencia se ejemplifica en la influyente obra —en su día y en la actualidad— El Azar y la Necesidad de Jacques Monod. Estas ideas se contrastan con el pensamiento sociobiológico de los últimos tiempos. De este modo, se ilustra y subraya cómo en toda relación biológica mínimamente simbiótica todo ser vivo intenta romper a su favor la relación contractual subyacente mediante el engaño y, asimismo, intenta detectar el engaño potencial en su interlocutor, pretensión que se da tácitamente por supuesta. De manera que la única doctrina ética acorde con el conocimiento bioevolucionista actual sería un «altruismo recíproco vigilado».

  7. Efectos ecológicos de la erosión en laderas derivadas de la minería del carbón a cielo abierto

    OpenAIRE

    Moreno de las Heras, Mariano

    2009-01-01

    La minería a cielo abierto del carbón representa una actividad con una elevada capacidad de transformación del territorio. La restauración de las áreas afectadas por esta actividad es una tarea compleja, dado el nivel de alteración de los ecosistemas afectados y los múltiples factores involucrados en el desarrollo de los nuevos ecosistemas restaurados. Un fenómeno característico que puede limitar el desarrollo de estos ecosistemas artificiales es el desarrollo temprano de procesos intensos de...

  8. Estudo experimental e teórico da redução de bases de Schiff derivadas da 3,3-difenilpropilamina

    Directory of Open Access Journals (Sweden)

    Esteves-Souza Andressa

    2004-01-01

    Full Text Available A series of seven Schiff bases have been synthesized from 3,3-diphenylpropilamine and substituted benzaldehydes. These imines were treated with NaBH4 in ethanol affording the corresponding amines in 98-55% yields. A molecular modeling study was performed with the Schiff bases in order to compare the theoretical parameters with the experimental results. The theoretical parameters were obtained by AM1 and PM3 semi-empirical methods. The analysis of charge, electron densities and LUMO coefficients suggested that the most favorable interactions should occur with Schiff bases containing electron-donating groups, in accordance with experimental yields, showing that the higher reactivity is due to higher electrophilic character of imine carbons.

  9. Análisis de segregación de marcadores moleculares en una población derivada de Coffea liberica Hiern x C. eugenioides L.

    Directory of Open Access Journals (Sweden)

    Germán Ariel López Gartner

    2014-04-01

    Full Text Available El café es un cultivo importante para la economía mundial. La producción comercial de café se basa en dos especies, Coffea arabica L. (70% y C. canephora Pierre (30%. La primera es la única alotetraploide (2n = 4x = 44 que tiene su centro primario de diversidad en las tierras altas del suroeste de Etiopía; la segunda es la única cultivada en Colombia y representa un importante valor económico y social. Sin embargo, C. arabica tiene una base genética muy estrecha y por ello es importante el uso de especies diploides en el mejoramiento del café para ampliar su diversidad. En este trabajo fueron evaluados los patrones de segregación genética en una población consistente en 101 plantas híbridas F1 de un cruce entre la especie diploide C. liberica y C. eugenioides utilizando 618 marcadores moleculares, de las cuales 168 SSR y 2 EST exhibieron patrones polimórficos que permitieron el análisis de segregación. Aproximadamente 24% de los loci fueron alelos nulos y la distorsión de la segregación alcanzó 23.5% (α < 0.01. Se observaron un total de cuatro tipos segregantes de entre siete posibilidades diferentes. Se discuten los orígenes de los alelos nulos, posibles causas de distorsión de la segregación, diferentes patrones de segregación y frecuencias de recombinación. El conocimiento derivado de este estudio permite entender mejor el comportamiento de la segregación genética de estos marcadores, con el fin de desarrollar mapas genéticos que tienen aplicaciones importantes para los programas de mejoramiento de café y de otras especies comerciales.

  10. Activities of the Radiological Environmental Division related to the Fukushima accident; Actuaciones de la Division de Medio Ambiente Radiologico derivadas del accidente de Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, T.; Gasco, C.; Robles, B.; Montero, M.

    2011-07-01

    The recent Fukushima accident has shown that the scientific community and the general public is very much interested in and concerned about knowing the possible current and future consequences that an accident of this nature can have in both the local population and the rest of the world. It also reveals that society, even though it is not directly affected, feels that it is affected and demands not only fast, effective responses from national authorities, but also a greater involvement of all international bodies related to Nuclear Safety and to Radiological Protection of the public and the environment and a better coordination between them. (Author)

  11. Condiciones físicas de la envoltura de baja velocidad de CRL618 derivadas de modos vibracionalmente excitados de HC3N

    Science.gov (United States)

    Pardo, J. R.; Cernicharo, J.; Goicoechea, J. R.

    The complete sequence of HC3N rotational lines from J=9-8 to J=30-29 has been observed with the IRAM 30m telescope toward the protoplanetary nebula CRL618. A total of 15 different vibrational states (including the fundamental) with energies up to 1100 cm-1 have been detected. The CSO telescope has been used to complement this study in the range Jup 31 to 39, with detections in five of these vibrational states, all of them below 700 cm-1. The lines from HC3N, its isotopic substituted species, and from HC5N, produce crowded millimeter and submillimeter wave spectra in CRL618. Only the rotational lines of HC3N in its ground vibrational state display evidence of the high velocity outflow first detected by Cernicharo et al. 1989. Vibrationally excited HC3N rotational lines exhibit P-Cygni profiles at 3 mm, known also in many other species in this object, evolving to pure emission at shorter wavelengths in a way slightly dependent on the vibrational state. The absorption features are formed against a continuum that averages ˜ 0.3 K in the TA* scale across the entire frequency range covered by the IRAM 30m telescope and is about 0.06 K in the frequency range scanned with the CSO (same scale). These results translate into integrated fluxes ranging from 1.75 Jy to 3.4 Jy in the frequency range 90 to 240 GHz, which subsequently translates into effective temperatures of the continuum source at 90 GHz ranging from 8700 to 15000 K for sizes between 0.18'' and 0.15'', with spectral indexes between -1.15 and -1.12. We have made an effort to simultaneously fit all observed HC3N ladders through a LTE radiative transfer model for HC3N in an expanding shell around the central and ultracompact HII region. We have explored both the spherical and the elongated shell cases. The simulations show evidence that the inner slowly expanding envelope has temperatures around 300 K, expansion and turbulence velocities of ˜ 5-13 and around 2.5 kms-1 respectively, and is possibly inclined respect to the line of sight and not totally spherical. The simultaneous match of the simulations to all HC3N rotational ladders provides the HC3N column density in the considered region. In front of the the continuum source we find it to be in the range 0.5-5\\cdot1017 cm-2. The temperature profile of the region is critical to decide which end of this range corresponds to reality. We favor a value around 5-10\\cdot1016 based on comparisons with HC3N vibrational absorptions in this source observed with ISO.

  12. Cuestiones sobre el derecho al trabajo derivadas de la reforma laboral de 2012 : perspectiva constitucional = The right to work under the labour reform of 2012: a constitutional approach

    OpenAIRE

    Naranjo De La Cruz, Rafael

    2014-01-01

    La reforma laboral de 2012 ha suscitado importantes cuestiones acerca del régimen jurídico del derecho al trabajo. Así, en este artículo se sostiene que la introducción de una modalidad contractual que concede al empresario la potestad de resolver libremente el contrato laboral durante el primer año supone, ya sea concebido este plazo como periodo de prueba o como medio para el fomento de un empleo estable, una vulneración del derecho del trabajador a la estabilidad en el empleo, reconocido c...

  13. Alternativas ecotecnológicas en la depuración de aguas residuales derivadas de la acuicultura y la producción animal

    OpenAIRE

    González Salas, R.; Romero Cruz, O.; Vidal del Río, M.; J.T. Ponce-Palafox

    2010-01-01

    Water bodies have increasingly got polluted in the last years due to unappropriate management of wastewaters having urban, industrial and agricultural origen, especially in less Developer nations. Development of ecotechnological alternatives through the use of aquatic plants such as Lemna sp. allows making use of natural resources and thus purify high contaminating loads that are produced by cattle raising and agricultural refuses, generating at the same time large amounts of b...

  14. Diferenciação de células-tronco mesenquimais derivadas do tecido adiposo em cardiomiócitos

    OpenAIRE

    Pablo Herthel Carvalho; Ana Paula Falci Daibert; Betânia Souza Monteiro; Bárbara Silva Okano; Juliana Lott Carvalho; Daise Nunes Queiroz da Cunha; Lukiya Silva Campos Favarato; Vanessa Guedes Pereira; Luis Eugênio Franklin Augusto; Ricardo Junqueira Del Carlo

    2013-01-01

    FUNDAMENTO: O potencial de renovação e proliferação dos cardiomiócitos, in vivo, é pequeno, e por isso, o músculo cardíaco apresenta limitada capacidade de repor células perdidas. Na tentativa de minimizar os danos oriundos de lesões hipóxico-isquêmicas e daquelas que acometem o sistema de condução do coração, a terapia celular com células-tronco mesenquimais (MSC) vem sendo utilizada, inclusive com cardiomiócitos diferenciados a partir de MSC. OBJETIVO: O presente trabalho comparou três prot...

  15. Diferenciação de células-tronco mesenquimais derivadas do tecido adiposo em cardiomiócitos

    Directory of Open Access Journals (Sweden)

    Pablo Herthel Carvalho

    2013-01-01

    Full Text Available FUNDAMENTO: O potencial de renovação e proliferação dos cardiomiócitos, in vivo, é pequeno, e por isso, o músculo cardíaco apresenta limitada capacidade de repor células perdidas. Na tentativa de minimizar os danos oriundos de lesões hipóxico-isquêmicas e daquelas que acometem o sistema de condução do coração, a terapia celular com células-tronco mesenquimais (MSC vem sendo utilizada, inclusive com cardiomiócitos diferenciados a partir de MSC. OBJETIVO: O presente trabalho comparou três protocolos distintos de indução de diferenciação objetivando a sugestão de um método viável para a diferenciação de maior número de células funcionais que expressem fenótipo cardiomiogênico. MÉTODOS: Culturas de MSC obtidas de tecido adiposo de ratos jovens da linhagem Lewis transgênicos para proteína verde fluorescente (GFP foram submetidos a três diferentes meios de diferenciação cardiogênica: Planat-Bérnard, 5-azacitidina e meio Planat-Bérnard + 5-azacitidina e observadas quanto a expressão de marcadores celulares cardíacos. RESULTADOS: Nos três protolocos utilizados observou-se formação da proteína alfa-actinina sarcomérica no citoesqueleto das células submetidas à diferenciação, expressão de conexina 43 na membrana nuclear e citoplasmática e formação de gap junctions, necessárias para a propagação do impulso elétrico no miocárdio, contudo, em nenhum protocolo foi observada contração espontânea das células submetidas à diferenciação cardiogênica. CONCLUSÃO: A indução com 5-azacitidina proporcionou diferenciação celular cadiomiogênica efetiva e similar à encontrada com o meio Planat-Bénard e, por ser um protocolo mais simples, rápido e com menor custo torna-se o método de eleição.

  16. Fórmulas de recurrencia entre Pm y la derivada k-esima de la delta de Dirac soportada en P

    Directory of Open Access Journals (Sweden)

    M. Aguirre

    2009-12-01

    Full Text Available En este artículo se le dio un sentido a la fórmula de recurrencia Pm .δ (k (P -Cm, kδ (k-m (P = 0 si k ≥ m (ver fórmula 15 considerando la condición gradP ≠ 0, donde la constante Cm,k fue definida por la fórmula 16. En el segundo parágrafo se le dio un sentido a la misma fórmula pero para un caso especial: P = P(x = P(x1, ...xn = x12 + x22 + ...xp2 - xp+12 - ...xp+q2.La fórmula que se obtuvo es una generalización de fórmulas que aparecen en el libro de Gelfand and Shilov formula (c.f. ([1], página 233 y es considerada por ejemplo por Bollini, Giambiagi and Tiomno para la teoría de regularización analítica en las ecuaciones clásicas de Yang-Mills y sus aplicaciones para el potencial singular (c.f. [4].

  17. Transplante de células-tronco derivadas do tecido adiposo em ratos submetidos à lesão medular compressiva, com e sem tratamento com corticoide

    OpenAIRE

    Villanova Junior, José Ademar

    2013-01-01

    Resumo: O trauma constitui uma causa relevante de mortalidade no mundo, atinge principalmente a população jovem, economicamente ativa, e leva muitas vezes a sequelas incapacitantes. O tratamento convencional após o trauma é a utilização de corticoide, que nem sempre apresenta resultado satisfatório. As células-tronco têm sido utilizadas em vários ensaios pré-clínicos de lesão medular e são consideradas uma alternativa promissora. A interrupção da fase inflamatória e a utilização da terapia ce...

  18. Intraabdominal desmoplastic small cell tumor: radiological aspects - a case report; Tumor de pequenas celulas desmoplasico intra-abdominal - relato de um caso

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Leonardo Velloso; Siciliano, Antonio Alexandre O.; D' Annunciacao, Gisele Esteves; Nunes, Vania Cristina S.R. [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil). Dept. de Radiologia; Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia

    1999-06-01

    The authors describe a case of a 21-year-old white female admitted with abdominal pain and distension, as well as bowel movement alteration. A hard, lobulated and painful abdominal mass was found at physical exam and signs of ascitis were also presented. Abdominal and pelvic ultrasound and computed tomography demonstrated and heterogeneous mass, adhering to the anterior abdominal wall, extending from the umbilicus to the pelvis and displacing the urinary bladder inferiorly and bowel loops posteriorly. Cul-the-sac implants were also noted. The major omentum was diffusely infiltrated by nodules as laparotomy. A desmoplastic small cell tumor was found after histopathological analysis of the surgical specimen. (author)

  19. Infiltración meningea por leucemia a celulas plasmáticas y por linfoma no Hodgkin: estudio citomorfologico en el liquido cefalo-raquideo

    Directory of Open Access Journals (Sweden)

    Arnaldo Tabares Olives

    1982-06-01

    Full Text Available Son presentadas las características citomorfológicas anormales encontradas en el LCR de dos pacientes, uno de ellos sufriendo de leucemia aguda a células plasmáticas y otro de linfoma mixto no Hodgkin. Se enfatiza la importancia del estudio del LCR en estas patologias.

  20. Linfoma de celulas B de la zona marginal extraganglionar del tejido linfoide asociado a mucosa (linfoma MALT de pulmón

    Directory of Open Access Journals (Sweden)

    Carlos Vergara-Uzcategui

    2014-09-01

    Full Text Available Los Linfomas Pulmonares Primarios son extremadamente raros (0,4% de los linfomas extraganglionares, y generalmente son de tejido linfoide asociado a mucosas (tipo MALT, con ocasionales linfomas de células grandes difusos. Los síntomas son inespecíficos, y casi la mitad de los pacientes son asintomáticos. Se presenta el caso de un paciente masculino de 56 años de edad, quien presentó durante 7 meses accesos diarios de tos seca, de predominio nocturno, asociados en el último mes a fiebre de 39ºC, disnea a medianos esfuerzos y expectoración verduzca. Los exámenes de laboratorio fueron normales. La radiografía de tórax mostró el mediastino ensanchado, un proceso en lóbulo medio con efecto atelectásico, y un nódulo en hemitórax izquierdo. La tomografía computarizada (TC torácica de alta resolución evidenció proceso alveolar derecho en lóbulo medio y un nódulo pulmonar izquierdo calcificado de tipo inespecífico. El estudio inmunohistoquímico de la biopsia pulmonar fue compatible con Linfoma de Células B de la zona marginal extraganglionar del tejido linfoide asociado a mucosa (Linfoma MALT de pulmón. La TC corporal y la Tomografía por Emisión de Positrones (PET evidenciaron importantes hallazgos complementarios para determinar la extensión de la enfermedad. El paciente se trato con quimioterapia y actualmente se encuentra en buenas condiciones, sin recidiva de la sintomatología. Dado lo infrecuente de la patología se presenta este caso y se hace una revisión de la literatura

  1. Photovoltaic network connection portraits (XIV): The issue of hot cells; Retraso de la conexion fotovoltaica a la red (XIV): El asunto de las celulas calientes

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzo, E.; Martinez, F.; Moreton, R.

    2009-07-01

    In some cases due to plants performance is not as correct as hoped, and in some other, simply because the nice colors of the thermographs resulted very attractive to plenty of people; many photovoltaic generators have been profusely thermography within the current year. It has caused a special interest on hot cells phenomenon, that is to say those cells which operate at a significantly higher temperature than other placed in the same panel. (Author) 4 refs.

  2. Granulosa Cell Tumor Juvenile - Case Report-Primary Care Tumor de Celulas da Granulosa Juvenil - Relato de Caso em Atenção Primária

    Directory of Open Access Journals (Sweden)

    Anelise Olmos Grings

    2010-11-01

    Full Text Available

    The authors given an account of children of 2 years and 4 months with ginaecology complaints (white vaginal secretion, diffuse abdominal pain and early pseudo-puberty. Beginning investigation in Unity of Health Care PSF of Porto Alegre, are refer to the secondary levei was diagnosis ovarian tumor (Juvenile Granulosa Cell Tumor Ovary.

    Os autores relatam o caso de urna criança de 2 anos e 4 meses com queixas ginecológicas (secreção vaginal branca, dor abdominal difusa e pseudopuberdade precoce (telarca. Iniciada investigação em Unidade de Saúde PSF de Porto Alegre, sendo referenciada ao nível secundário onde foi diagnosticada neoplasia ovariana (Tumor de Células da Granulosa Juvenil.

  3. Langerhans cell histiocytosis with multifocal sites. A case report; Histiocitose de celulas de Langerhans com acometimento multifocal. Relato de um caso

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Silvio Cavalcanti; Silveira, Andre; Ribeiro Neto, Joao Vicente [Instituto Materno Infantil de Pernambuco (IMIP), Recife (Brazil)

    1998-05-01

    The authors report a case of Langerhans cell histiocytosis in which the patient, at the time of the diagnosis, had lesions at the central nervous system, mediastinum and long bones, all detectable in simple roentgenogram. The recent reclassification of this disease is discussed together with it`s radiological findings. (author) 4 refs., 6 figs.

  4. Localized giant cell tumors in the spinal column radiologic presentation. Tumor de celulas gigantes localizado en la columna dorsal: presentacion radiologica poco frecuente

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Echeverria, M.A.; Parra Blanco, J.A.; Pagola Serrano, M.A.; Mellado Santos, J.M.; Bueno Lopez, J.; Gonzalez Tutor, A. (Hospital Marques Valdecilla. Santander (Spain))

    1994-01-01

    Given the uncommonness of the location of giant cell tumors (GCT) in the spinal column and the limited number of studies published, we present a case of GCT located in the spinal column, which involved both vertebral bodies and partially destroyed the adjacent rib. (Author)

  5. Interpenetrating polymer network membranes for fuel cells: infrared vibrational spectroscopy; Membranes baseadas dm redes polimericas interpenetrantes para celulas a combustivel: estudo por espectroscopia vibracional no infravermelho

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Felipe A.M.; Rocco, Ana Maria [Grupo de Materiais Condutores e Energia, Escola de Quimica, Universidade Federal do Rio de Janeiro, RJ (Brazil)], e-mail: amrocco@eq.ufrj.br; Pereira, Robson Pacheco [Instituto de Ciencias Exatas, Universidade Federal Fluminense (UFF), Volta Redonda, RJ (Brazil)

    2011-07-01

    In the present work, proton conductive membranes based on IPN matrices doped with H{sub 3}PO{sub 4} were developed. The characterization by infrared vibrational spectroscopy evidenced the polymerization of DGEBA and the immobilization of PEI chains, originating a structure containing basic sites suitable for proton coordination and conduction. The FTIR characterization evidenced the polymerization of DGEBA in the presence of PEI thus forming Semi-IPN membranes which, after doped with H{sub 3}PO{sub 4}, exhibited conductivity values of 10{sup -4} W{sup -1}cm{sup -1} at room temperature and 10{sup -3} {omega}{sup -1}cm{sup -1} at 80 degree C, as well as a dependency of conductivity with temperature following the Arrhenius model. The activation energy values (14,33 and 12,96 kJ.mol{sup -1}) indicated a proton conduction mechanism predominantly vehicular in the matrices studied under 100% relative humidity. (author)

  6. CARCINOMA ODONTOGÉNICO DE CELULAS CLARAS. ESTUDIO CLÍNICO, RADIOLÓGICO Y PATOLÓGICO DE UN CASO.

    Directory of Open Access Journals (Sweden)

    Rosaura Rodríguez Flores

    2004-01-01

    Full Text Available Los tumores odontogénicos (TO son un grupo complejo y poco frecuente de neoplasias con características clínicas, radiológicas, histopatológicas y evolución muy variables. El Carcinoma odontogénico de células claras (COCC es una neoplasia maligna, de comportamiento agresivo variable que se presenta en maxilares. Histológicamente se constituye de nidos de células, frecuentemente de citoplasma claro, rico en glucógeno, rodeadas por bandas de colágena. Pertenece al grupo de los tumores odontogénicos epiteliales malignos. Se presenta el caso de un hombre de 57 años con un tumor en hueso y seno maxilar izquierdo, sometido a hemimaxilectomía subtotal izquierda. Los estudios de imagen demostraron una lesión destructiva mixta en maxilar y seno maxilar izquierdo y la histología reveló la imagen clásica de COCC y la inmunohistoquímica mostró inmunoreactividad para Queratina AE1/AE3, EMA y S-100 (focal. Se demostró abudante glucógeno mediante la reacción de PAS en el citoplasma de las células neoplásicas. El paciente ha tenido seguimiento por 5 años y está asintomático después de la cirugía sin tratamiento complementario con radioterapia.

  7. Estudos sobre a regeneração do figado - variação do volume nuclear das celulas hepáticas em repouso divisional

    Directory of Open Access Journals (Sweden)

    Fernando Ubatuba

    1948-12-01

    Full Text Available Surgical removal of large amounts of hepatic tissue in male albino rats results in a rapid and conspicuous raise in cellular nuclear volumes. Measurements were made exclusively in resting nuclei. This volume variation is transitory. Nuclear volumes return to the normal value withins 6 days of restoration. The higher value are abserved 48 hours after the hepatic removal, indicating probably that this effect is due to hydration of the nucei, as occurs in the cytoplasm. This hydration could be correlated to the mitotic activity of the renmant tissue since a peak of mitoses parallels the changes in the nuclear volumes.

  8. Polyester synthesis for application in PEMFC type fuel cells; Sintese de poliester para aplicacao em celulas a combustivel do tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, R.P.; Souza, D.R. de; Fiuza, R.A.; Jose, N.M.; Boaventura, J.S. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica], e-mail: raigenis@gmail.com

    2006-07-01

    The PEMFC (Proton Exchange Membrane Fuel Cell), along the SOFC (Solid Oxide Fuel Cell), is the most important technology, among the various types of fuels cell. The PEMFC shows a large versatility of applications, both for stationary and mobile use. However the PEMFC presents high manufacture cost, directly impacting in the cost of the produced energy. This work contemplates the previews sulfonation of phtalic acid and its subsequent polymerization with glycerol, using as catalytic tin dibutyl-dilaurate. The obtained material has been characterized by DSC, TGA, FTIR, MEV, DRX and XRF. The gotten results indicated that phtalic acid was sulfonated and the increase of the sulfonation degree significantly increased the crystallinity of the sulfonated ftalico acid. Furthermore, the polymer produced from the sulfonated monomer presented adequate thermal resistance and a high content of conducting groups, necessary conditions for application as electrolyte in PEMFC. All these characteristics, particularly the low cost of the reagents and the ease of production process, make the sulfonated polyester membrane a promising candidate as fuel cell electrolyte. (author)

  9. Fuel cells using ionic liquids as electrolyte and operating at room temperature; Celulas de combustivel utilizando como eletrolito liquidos ionicos e operando a temperatura ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Botton, Janine Padilha; Souza, Roberto Fernando de; Goncalves, Reinaldo Simoes; Dupont, Jairton [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica], e-mail: janine@iq.ufrgs.br

    2004-07-01

    The room temperature imidazolium based ionic liquids, such as 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF4) are outstanding electrolytes for fuel cells. A 67% overall cell efficiency is achieve using these liquids as supporting electrolytes for a commercially available alkaline fuel cell (AFC) at room temperature operating with air and hydrogen at atmospheric pressure. (author)

  10. Preparation of PVDF and PTFE membranes for fuel cell use; Preparacao de membranas de PVDF e PTFE enxertadas e sulfonadas para uso em celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Geraldes, Adriana N.; Zen, Heloisa A.; Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B.; Linardi, Marcelo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: angeral@ipen.br

    2007-07-01

    Grafting of styrene onto polyvinylidenefluoride (PVDF), polytetrafluoroethylene (PTFE) was studied using styrene/toluene solutions. First, PTFE and PVDF films were prepared and the process was conducted by radiation induced graft polymerization of styrene, by a Co{sup 60} source. Films of PTFE and PVDF were immersed in styrene/toluene at 1:1 (v/v) concentration and then submitted to gamma radiation at 20 kGy doses. After irradiation, the samples were evaluated at the period of 21 days at room temperature in order to observe the grafting degree. Chemical changes in the PVDF and PTFE films after styrene grafting were monitored and the results were evaluated by FTIR, DSC, TGA and degree of grafting (DOG). The ion exchange capacity (IEC) after sulfonation of 1, 2 and 24 hours were also determined. (author)

  11. Hybrid membranes PVA/silicon for use in fuel cells; Membranas hibridas de PVA/silica para aplicacao em celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Liz C.V. de; Almeida, Raquel D. de; Gomes, Ailton de S. [Universidade Federal do Rio de Janeiro - UFRJ, Instituto de Macromoleculas Professora Eloisa Mano - IMA, RJ (Brazil)], e-mail: lizcontino@ima.ufrj.br; Ramos Filho, Florencio G. de [Centro Universitario Estadual da Zona Oeste - UEZO, Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Hybrids organic-inorganic membranes PVA-silica have been prepared using sol-gel process in situ with the objective of study the influence of inorganic particles incorporation on the water uptake, pervaporation and proton conductivity of PVA membranes. The silica was constituted of mercaptopropyltrimethoxysilane (MPTMS) with or without the mixture with the tetra ethoxysilane (TEOS). The hybrids membranes were oxidated to convert the -SH groups in -SO{sub 3}H groups, becoming them proton conducting. The hybrids membranes not oxidated showed lesser water uptake and pervaporated material, probably, due to the formation of crosslink that restricted the swell of the PVA membrane. The protonic conductivity of the hybrid membranes after the oxidation was up to 26 times bigger than of the membrane not oxidated. (author)

  12. Development of perovskite cathodes for solid oxide fuel cells (SOFC); Desenvolvimento de catodos de perovskitas para celula a combustivel solido de eletrolito solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Perez, J. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica], e-mail: joelma@iq.unesp.br; Pereira, J.T.; Saeki, M.J. [UNESP, Bauru, SP (Brazil). Faculdade de Ciencias

    2006-07-01

    Solid Oxide Fuel Cells (SOFC) are energy conversion systems of great interest for industrial applications because they present a high efficiency for energy generation and several advantages for the environment. In this work, perovskite type oxides La{sub 085}Sr{sub 0,15}MnO{sub 3}, La{sub 0,7} Sr{sub 0,3}MnO{sub 3}, La{sub 0,6}Sr{sub 0,4}MnO{sub 3}, La{sub 0,85}Sr{sub 0,15}CoO{sub 3}, La{sub 0,7}Sr{sub 0,3}CoO{sub 3}, La{sub 0,6}Sr{sub 0,4}CoO{sub 3}, La{sub 0.6}Sr{sub 0,4}Fe{sub 0,8}Co{sub 0,2}O{sub 3} e La{sub 0.6}Sr{sub 0,4}Fe{sub 0,4}Co{sub 0,6}O{sub 3} were prepared by a polymeric method with the purpose of using them as cathodes in SOFCs. The electrochemical cell was mounted utilizing YSZ (ZrO{sub 2} - 8 mol%Y{sub 2}O{sub 3}) disks as electrolyte, where a paste containing Pt was calcined onto one face while the other one was covered with the oxide materials synthesized ('screen printing'). The oxide materials prepared were characterized by X-ray diffraction, transmission electronic microscopy and thermogravimetry. The oxygen reduction reaction was studied by taking polarization curves in oxygen and/or air (800 deg C a 950 deg C). The best performance was obtained for 15 {mu}m thickness electrodes La{sub 0.6}Sr{sub 0,4}MnO{sub 3} and La{sub 0.6}Sr{sub 0,4}MnO{sub 3} with addition of dispersed Pt. (author)

  13. Implementation of a photovoltaic/electrolyzer/fuel cell autonomous system; Implementacao de um sistema autonomo fotovoltaico/eletrolisador/celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ennio Peres da; Apolinario, Fernando Rezende; Furlan, Andre Luis [Universidade Estadual de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Lab. de Hidrogenio], Emails: lh2ennio@ifi.unicamp.br, rezende@ifi.unicamp.br; Souza, Rubem Cesar Rodrigues [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Centro de Desenvolvimento Energetico Amazonico], Email: rubem_souza@yahoo.com.br; Pinto, Adailton de Souza [Centrais Eletricas do Norte do Brasil S.A. (ELETRONORTE), Brasilia, DF (Brazil)], Email: adailton@eln.gov.br

    2006-07-01

    This article presents a project whose main objective is to analyze the technical feasibility of using a system based on the production of hydrogen (H{sub 2}) for storing the energy generated for photovoltaic systems. The work involves the design, physical implementation and the performance evaluation of a system for hydrogen electrolytic generation with solar-photovoltaic energy, the treatment os gas, its storage and it use in fuel cell systems. This work will be performed in cooperation between researchers from the Laboratorio de Hidrogenio (LH2) of the UNICAMP and of the Centro de Desenvolvimento Energetico Amazonico (CDEAM) of the UFAM, and is financing by ELETRONORTE.

  14. Platinum catalysts recovery of the proton exchange membrane fuel cell; Recuperacao de catalisadores de platina da celula a combustibel de membrana polimerica trocadora de protons

    Energy Technology Data Exchange (ETDEWEB)

    Fukurozaki, S.H.; Seo, E.S.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais. Lab. de Processamento de Residuos

    2006-07-01

    Currently, platinum is the most feasible catalyst for the Proton Exchange Membrane Fuel Cells - PEMFC. Along with platinum's significant importance in this energy system are the high cost of this noble metal and its detrimental effects on the environment. Therefore, recycling this material seems as an alternative to decrease its impacts on the environment and, at the same time, to provide a reduction of the system's costs. A search was conducted for literature and studies about platinum recycling methods. However, only two techniques of platinum recovery, which are still in development, were found. In face of this situation, a recovery method of platinum from deactivated Membrane Electrode Assembly - MEA's was developed, with attention to aspects related to the environment and the necessary requirements for its primary recycling. The results found showed a high recovery ratio and a possibility to reintroduce this metal into the production cycle. (author)

  15. Modelling and essay or the polarization curve of a polymeric membrane fuel cell; Modelagem e ensaio da curva de polarizacao de uma celula a combustivel de membrana polimerica

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Silvio Carlos Anibal de; Xavier, Bruno Domont; Gatti, George Cassani; Ribeiro, Rodrigo Minguita [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Mecanica]. E-mails: silvioa@gmail.com; brunodomont@gmail.com; gatti_ufrj@yahoo.com.br; rminguita@yahoo.com.br; Furtado, Jose Geraldo de Melo [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil). Dept. de Tecnologias Especiais]. E-mail: furtado@cepel.br

    2006-07-01

    This paper describes the essays performed with a polymeric membrane fuel cell (PEMFC) at the test laboratories of the ELETROBRAS Electric Energy Research Center (CEPEL/ELETROBRAS) manufactured by the Eletrocell, which allows to study the influence of some functional parameters (voltage, current, mass and pressure fluxes)

  16. Synthesis, characterization and electrical properties of solid electrolyte for solid oxide fuel cell; Preparacao, caracterizacao e propriedades eletricas de eletrolito solido para celula a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Berton, Marco Antonio Coelho; Garcia, Carlos Mario; Matos, Jeferson Hrenechen [Instituto de Tecnologia para o Desenvolvimento (LACTEC), Curitiba, PR (Brazil)], Emails: felsky@latec.org.br, garcia@latec.org.br, jeferson.h@latec.org.br

    2010-04-15

    Solid electrolytes of BaCe{sub 08}Gd{sub O29} were prepared by the polymeric precursor method. X-ray diffraction data shows a single phase with orthorhombic crystalline structure. The densification process was followed by scanning electronic microscopy and apparent density measurements. The apparent density was developed for different temperatures of sintering, reaching > 96% for sintered temperature of 1550 {sup 0}C deg . The electrochemical impedance analysis was development in the temperature of 400-700 deg C, in air atmosphere at 700 deg C a value of 30,6 mS.cm{sup -1} was obtained. The results of conductivity have confirmed the gadolinium doped barium cerate has a great potential for use as solid electrolyte for intermediate temperature solid oxide fuel cell, at experimental controlled conditions. (author)

  17. Fabrication and tests of anode supported solid oxide fuel cell; Fabricacao e testes de celula a combustivel de oxido solido suportada no anodo

    Energy Technology Data Exchange (ETDEWEB)

    Florio, D.Z. de [UNESP, Araraquara, SP (Brazil)], e-mail: dzflorio@ipen.br; Fonseca, F.C.; Franca, Y.V.; Muccillo, E.N.S.; Muccillo, R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Berton, M.A.C.; Garcia, C.M. [LACTEC - Instituto de Tecnologia para o Desenvolvimento, Curitiba, PR (Brazil)

    2006-07-01

    A laboratory setup was designed and put into operation for the development of solid oxide fuel cells (SOFCs). Ceramic single cells were fabricated by low-cost methods, and emphasis was given to the use of ready available raw materials. The whole project consisted of the preparation of the component materials - anode, cathode, and electrolyte - and the buildup of a hydrogen leaking-free sample chamber with platinum leads and current collectors for measuring the electrochemical properties of single SOFCs. Anode-supported single SOFCs of the type (ZrO{sub 2}:Y{sub 2}O{sub 3} + NiO) anode / (ZrO{sub 2}:Y{sub 2}O{sub 3}) electrolyte / (La{sub 0.65}Sr{sub 0.35}MnO{sub 3} + ZrO{sub 2}:Y{sub 2}O{sub 3}) cathode have been prepared and tested at 700 deg C and 800 deg C after in situ H{sub 2} anode reduction. The main results show that the slurry coating method resulted in single-cells with good reproducibility and reasonable performance, suggesting that this method can be considered for fabrication of SOFCs. (author)

  18. Technological evaluation of fuel cells using natural gas for distributed power generation; Avaliacao tecnologica da utilizacao de gas natural em celulas a combustivel para geracao distribuida de energia

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Mauricio O. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE). Programa de Engenharia Mecanica; Giannini, Marcio P.; Arouca, Mauricio C. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE). Programa de Planejamento Energetico

    2004-07-01

    The search for sustainable and more rational means of power generation motivates the scientific crew to search for more efficient and cleaner systems. Oil dependence becomes from the kind of development that the humanity had and cannot be dismissed. The question is how to use this source in a more intelligent way. Fuel Cells are electrochemical devices that convert into electric energy the chemical energy from oxi-reduction reactions between a fuel and an oxidant. The current fuel used in a Fuel Cell is hydrogen and oxygen is the oxidant. The great advantage of this device is its efficiency, higher than the one achieved with internal combustion engines. Also Fuel Cells are not limited by Carnot's efficiency. This paper is about the implementation of a distributed generation system using Fuel Cells. Technical aspects are approached together with economical and environmental needs. The already existence of Gas pipelines and the grown production of Natural Gas presented by Brazil turns it into a good market for the implementation of this energy source. The evaluation of this paper shows that is technically possible to use NG in Fuel Cells, mostly in South and Southeast regions, applying the distributed generation of energy concept. The most interesting in a strategic manner is that Brazil already have an indication that it's capable of developing this technology, opening a new market tuning with world's new technological developments. Many research centers develop this technology, not only from the cell composition itself, but also manufacturing techniques. (author)

  19. Polypropylene (PP) based proton exchange membrane for use in fuel cell; Obtencao de membrana trocadora de protons para uso em celula a combustivel, a base de polipropileno (PP)

    Energy Technology Data Exchange (ETDEWEB)

    Zen, Heloisa Augusto

    2008-07-01

    The radiation-induced graft of styrene onto polypropylene (PP) films was carried out by simultaneous irradiation method in a cobalt-60 source. The PP films were immersed in a solution of styrene with toluene (1:1 and 4:1, v/v) under inert atmosphere and at room temperature and then submitted at 20, 40, 80 and 100 kGy. After graft reaction the films were kept at room temperature under inert atmosphere for periods of 7, 14, 21 and 28 days in order to evaluate the degree of grafting. At the end of each period the films were sulfonated to provide the hydrophilic property to PP. The degree of grafting (DOG) was gravimetric determined and the chemical changes in the grafted and sulfonated films were characterized by Infrared Spectroscopy, Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry and the Ion Exchange Capacity (IEC) was calculated. The greatest DOG was obtained after 21 days of post-irradiation. By TGA the grafted films exhibited a decrease in the thermal stability, while the sulfonated exhibited an increase. By DSC was possible to verify that matrix polymeric did not suffer any drastic change in the melting temperature after grafting and sulfonation reactions. The IEC calculated shows that the new membrane developed has ionic conductivity property. (author)

  20. Polyethylene (PE) based proton exchange membrane for use in fuel cell; Obtencao de membranas trocadoras de protons a base de polietileno para uso em celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Gilberto de Oliveira

    2008-07-01

    The irradiation - induced graft of styrene onto polyethylene (PE) in a Cobalt-60 source was carried out using direct (simultaneous) and indirect (preirradiation and peroxidation) methods at room temperature. The dose applied in both cases varied from 0,5 to 80 kGy; In the direct method, the films were immersed in a solution of styrene: methanol (30:70 v/v) and 30% of sulfuric acid(additive) in glass ampoules of 40 ml under inert atmosphere, and then irradiated. After irradiation process, the samples were kept in solution for 8 hours and taken off the ampoules, dried in oven at 60 deg C for another 8 hour period until constant weight. In pre-irradiation method, the samples were irradiated in dry and sealed ampoules, under inert atmosphere. The solution was then added to the samples, and after 8 hours, taken off, dried, sealed and weighted. In peroxidation method, the difference was not inert atmosphere but atmosphere of air (0{sub 2}).For each samples it was calculated the degree of grafting (DOG). The samples that showed some DOG were sulfonated, characterized (DSC, TGA and infrared) and the ion exchange capacity (IEC) was calculated. The samples processed by indirect method presented no DOG at all. The samples processed by direct method present grafting (best result was 80 kGy). These samples, after sulfonated, presented ion exchange properties. (author)

  1. Technological study of experimental proton exchange polymer membrane fuel cells; Estudo tecnologico de celulas a combustivel experimentais a membrana polimerica trocadora de protons

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, Thais Aranha de Barros

    2004-07-01

    Experimental studies to achieve an optimized behavior of a unit PEM-fuel cell with an active area of 25cm{sup 2} were carried out. Polarization curves, surface response methodology and regression methodology were used for the analysis. The different methodologies identified the interactions between the parameters that were studied. These parameters were, humidifying temperature, fuel cell operating temperature and the flows of hydrogen and oxygen. MEAs were produced by the spray and hot pressing hybrid method, developed at IPEN. The studies were done with these MEAs and equivalent commercial ones. The MEAs producing method used induced an important variation on the quantity of platinum in the electrodes. This fact has showed to have a great influence in the results. The optimized values were: oxygen flow from 30 to 35% of consume (70 to 65% of excess), fuel cell operating temperature from 60 to 62 deg C and 0.41 mg of platinum in the electrodes. The hydrogen flows and the humidifying temperature have not showed a major influence in the fuel cell behavior, in the studied variable range. (author)

  2. Snake venoms components with antitumor activity in murine melanoma cells; Componentes derivados de venenos de serpentes com acao antitumoral em celulas de melanoma murino

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Rodrigo Guimaraes

    2012-07-01

    Despite the constant advances in the treatment of cancer, this disease remains one of the main causes of mortality worldwide. So, the development of new treatment modalities is imperative. Snake venom causes a variety of biological effects because they constitute a complex mixture of substances as disintegrins, proteases (serine and metalo), phospholipases A2, L-amino acid oxidases and others. The goal of the present work is to evaluate a anti-tumor activity of some snake venoms fractions. There are several studies of components derived from snake venoms with this kind of activity. After fractionation of snake venoms of the families Viperidae and Elapidae, the fractions were assayed towards murine melanoma cell line B16-F10 and fibroblasts L929. The results showed that the fractions of venom of the snake Notechis ater niger had higher specificity and potential antitumor activity on B16-F10 cell line than the other studied venoms. Since the components of this venom are not explored yet coupled with the potential activity showed in this work, we decided to choose this venom to develop further studies. The cytotoxic fractions were evaluated to identify and characterize the components that showed antitumoral activity. Western blot assays and zymography suggests that these proteins do not belong to the class of metallo and serine proteinases. (author)

  3. Wind, photovoltaic and fuel cell energy for communication stations; Energia eolica, fotovoltaica e de celula a combustivel para estacoes de comunicacao

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Iolanda; Pereira, Jose; Alcobia, Hernani [Net Plan Telecomunicacoes e Energia, Lisboa (Portugal); Pereirinha, Paulo [Instituto Politecnico de Coimbra (Portugal); Instituto para Engenharia de Sistemas e Computadores de Coimbra (Portugal)

    2011-10-15

    This paper presents a hybrid system that provides power to a remote and autonomously telecommunications station by means of electrical solar generators, wind and hydrogen fuel cell. In the absence of sufficient sun and wind, a bank of batteries and hydrogen produced on-site guarantee the power supply. The station can still be remote monitored and managed.

  4. Operating Cell Temperature Determination in Flat-Plate Photovoltaic Modules; Calculo de la Temperature de Operacion de Celulas Solares en un Panel Fotovoltaico Plano

    Energy Technology Data Exchange (ETDEWEB)

    Chenlo, F.

    2002-07-01

    Two procedures (simplified and complete) to determine the operating cell temperature in photovoltaic modules operating in real conditions assuming isothermal stationary modules are presented in this work. Some examples are included that show the dependence of this temperature on several environment (sky, ground and ambient temperatures, solar irradiance, wind speed, etc.) and structural (module geometry and size, encapsulating materials, antirreflexive optical coatings, etc) factors and also on electrical module performance. In a further step temperature profiles for non-isothermal modules are analysed besides transitory effects due to variable irradiance and wind gusts. (Author)

  5. DE LA MENTE A LA CELULA: IMPACTO DEL ESTRES EN PSICONEUROINMUNOENDOCRINOLOGIA/ FROM THE MIND TO THE CELL: THE IMPACT OF STRESS ON PSICONEUROIMMUNOENDOCRINOLOGY

    Directory of Open Access Journals (Sweden)

    Manolete S. Moscoso*

    2009-10-01

    Full Text Available Resumen:El presente artículo revisa el concepto del modelo psicobiosocial presentado por Engel y los primeros estudios sobre lanueva ciencia de la psiconeuroinmunoendocrinología, publicados por Solomon en la década del 60', y Ader en la década del70'. Se hace mención a los avances modernos en tecnología médica y de laboratorio como el punto de partida de un extensonúmero de estudios multidisclinarios durante la década del 80' que demuestran la relación entre el cerebro, y los sistemasnervioso, endocrino e inmune en el desarrollo de enfermedades. Se hace un análisis del concepto actual del estrés y unabreve revisión de las respuestas emocional y fisiológica descritas por Lazarus, Cannon, Selye, respectivamente. Una nuevavisión acerca del estrés es presentada y se hacen las distinciones correspondientes en relación a la respuesta comportamentaldel estrés, estilo de vida, y el estrés crónico. Finalmente se discute brevemente acerca del impacto negativo del estréscrónico sobre la salud del individuo.Abstarct:This article reviews the biopsicosocial model provided by Engel and the first studies in the field ofpsychoneuroimmunoendocrinology published by Solomon during the 60's and Ader during the 70's. it is pointed out thatadvances in medical technology and laboratory facilitated the beginning of studies in this field during the 80's. Extensivedata reports conclusive evidence of the interconnections between the brain, the nervous, endocrine and immune systems andthe development of disease. We discussed the emotional and physiological responses to stress as described by Lazarus,Cannon, and Selye. A new vision about stress is presented, taking into account the behavioral response to stress, life style,and chronic stress. Finally, we discussed briefly about the negative impact of chronic stress on health.

  6. Multi-metallic anodes for solid oxide fuel cell applications; Anodos multi-metalicos para aplicacoes em celulas a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Restivo, T.A. Guisard; Mello-Castanho, S.R.H. [Instituto de Pesquisas Energeticas e Nucleares (CCTM/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia dos Materiais; Leite, D. Will [Instituto de Pesquisas e Estudos Industriais (IPEI/FEI), Sao Bernardo do Campo, SP (Brazil). Fac. de Engenharia Industrial

    2009-07-01

    A new method for direct preparation of materials for solid oxide fuel cell anode - Ni- YSZ cermets - based on mechanical alloying (MA) of the original powders is developed, allowing to admix homogeneously any component. Additive metals are selected from thermodynamic criteria, leading to compacts consolidation through sintering by activated surface (SAS). The combined process MA-SSA can reduce the sintering temperature by 300 deg C, yielding porous anodes. Densification mechanisms are discussed from quasi-isothermal sintering kinetics results. Doping with Ag, W, Cu, Mo, Nb, Ta, in descending order, promotes the densification of pellets through liquid phase sintering and evaporation of metals and oxides, which allow reducing the sintering temperature. Powders and pellets characterization by electronic microscopy and X-ray diffraction completes the result analyses. (author)

  7. Giant cell tumor of the metatarsal bone: case report and review of the literature; Tumor de celulas gigantes do metatarso: relato de caso e revisao da literatura

    Energy Technology Data Exchange (ETDEWEB)

    Benites Filho, Paulo R.; Escuissato, Dante L. [Hospital de Clinicas da Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Servico de Radiologia]. E-mail: danteluiz@onda.com.br; Urban, Linei A.B.D. [DAPI - Diagnostico Avancado por Imagem, Curitiba, PR (Brazil); Gasparetto, Taisa P. Davaus [Hospital Universitario Antonio Pedro (HUAP), Niteroi, RJ (Brazil). Dept. de Radiologia; Sakamoto, Danielle; Ioshii, Sergio [Hospital de Clinicas da Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Servico de Anatomia Patologica; Marchiori, Edson [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia

    2007-07-01

    Giant cell tumor of bone is a rare neoplasm and account for 5% of all primary bone tumors. It is common in the knee and wrist, but rare in the small bones of the foot. The authors report a 32-year old male patient presented with a four-month history of right foot pain. Plain radiographs showed an expansive lytic lesion involving the first right metatarsal bone. Computed tomography scan demonstrated a radiolucent lesion with well-defined borders. Biopsy was performed and the histological diagnostic was giant cell tumor. The authors emphasize the correlation between the imaging and histological findings. (author)

  8. Desmoplastic small round cell tumor: a case report and review of the literature; Tumor desmoplastico de pequenas celulas: relato de caso e revisao da literatura

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Luiz Gustavo Teixeira [Hospital e Maternidade Marieta Konder Bornhausen, Itajai, SC (Brazil). Servico de Medicina Interna; Isberner, Rony Klaus [Hospital e Maternidade Marieta Konder Bornhausen, Itajai, SC (Brazil). Servico de Radiologia]. E-mail: ronyklaus@terra.com.br; Scolaro, Bruno Lorenzo [Universidade do Vale do Itajai, SC (Brazil). Curso de Medicina]. E-mail: brunoscolaro@yahoo.com.br; Sezerino, Daniel Oseias [Universidade do Vale do Itajai, SC (Brazil). Curso de Medicina. Disciplina de Anatomia Patologica; Almeida, Daniel da Silva [Hospital e Maternidade Marieta Konder Bornhausen, Itajai, SC (Brazil). Servico de Radiologia e Diagnostico por Imagem

    2006-10-15

    Desmoplastic small round cell tumor is a rare and highly aggressive neoplasm that predominantly occurs in young adult males. Pain and abdominal distention are frequent, ascites could be observed. His histogenesis is uncertain and the most common location is the peritoneal cavity. This tumor is characterized by presenting a distinct morphology and polyphenotypic differentiation. We present in this report the case of an adolescent admitted in the service of Internal Medicine and Radiology of the Hospital and Maternity Marieta Konder Bornhausen, Itajai, SC, Brazil, in year 2005. (author)

  9. Electric power generation using photovoltaic solar cells for low income rural population; Geracao de energia eletrica com celula solar fotovoltaica para populacao rural de baixa renda

    Energy Technology Data Exchange (ETDEWEB)

    Gastaldi, Andre Fava; Souza, Teofilo Miguel de; Mesquita, Rafael Pimenta [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Guaratingueta, SP (Brazil). Centro de Energias Renovaveis], e-mail: teofilo@feg.unesp.br

    2004-07-01

    With the growing electric energy use demand and almost not expansion of the energy mesh (basically composed by hydroelectric plants) existing in the country, several others methods of alternative energy generation may be necessary. Beyond that, the usually employed energy is becoming much more costly, rarer and politically more impracticable like burn fuels as oil and coal. The use of renewable approaches of energy, that are 'infinite' energies (as the wind and the light of the sun, for example), can become an excellent alternative. In this new energy group, the solar energy transformed by the use of photo voltage cells is becoming very important. The 'clear' solar radiation tends to be a more intelligent and practical option, and the future technology of energy storage will be able to solve the problem of the regions that have less sunny days. Its main advantages on the other alternative sources of energy are the trustworthiness and the previsibility. Its biggest disadvantage consists on the fact that technical limitations can not allow a solar energy generator to distribute electricity for a city. It is interesting to notice that with the development of projects as this in alternative energy, isolated areas that does not access electricity distribution network (as some far regions), it has become the most viable option of generation of electric energy. Another point is that even with the distribution network it has to be checked if it is possible to use this electricity consulting the company credential that work at those localities of consumption. Moreover, many regions of the country already installed the solar energy system for water heating, confirming that, the existing structure allows the installation of a a solar cells generation energy system without many problems. In this project, we introduce a method for electric energy generation by solar cells for rural population of low gains. This option uses low cost materials but with a good quality level. Also presents a comparative table showing a kit for rural areas employment which is constituted of: 3 fluorescent light bulbs (power of 9 W, 3 hours per day, 7 days per week), 1 T.V. of 14' ' (power of 15 W, 3 hours per day, 7 days per week) and 1 Radio (power of 5 W, 6 hours per day, 5 days per week). (author)

  10. Hydrogen purification for fuel cells using gold catalysts promoted with copper; Purificacao de hidrogenio para celulas a combustivel utilizando catalisadores de ouro promovidos com cobre

    Energy Technology Data Exchange (ETDEWEB)

    Mozer, Thiago Simonato; Passos, Fabio Barboza [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Quimica e de Petroleo. Lab. de Reatores, Cinetica e Catalise (RECAT)]. E-mail: mozer@vm.uff.br

    2008-07-01

    The selective CO oxidation in the presence of H2 was investigated on Au catalysts promoted with different amounts of Cu. Au catalysts were prepared by the deposition-precipitation method and exhibited a satisfactory activity at 50 deg C with adequate selectivity. The addition of Cu to Au/Al{sub 2}O{sub 3} catalysts caused an increase in the selectivity to CO oxidation due to an interaction between Au and Cu on the surface of the catalysts. However, this beneficial effect was limited to an optimal content of Cu. Through the temperature programmed reduction (TPR) and ultraviolet visible diffuse reflectance spectroscopy (UV-vis DRS) techniques, the formation of small bimetallic Au-Cu particles was verified. The best result was obtained with 2.5% Au-0.5% Cu/Al{sub 2}O{sub 3} catalyst, the CO conversion was higher than 95% and the selectivity was around 70% at 50 deg C. The catalysts showed stable catalytic activity during 24 hours time -on-stream. In the presence of H{sub 2}O and CO{sub 2}, a small decrease in the CO conversion was observed in the stability test, probably due to the deactivation caused by the CO{sub 2} presence. (author)

  11. Dancoff factors of unit cells in cluster geometry with partial absorption of neutrons; Fatores de Dancoff de celulas unitarias em geometria cluster com absorcao parcial de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Leticia Jenisch

    2011-01-15

    In its classical formulation, the Dancoff factor for a perfectly absorbing fuel rod is defined as the relative reduction in the incurrent of resonance neutrons into the rod in the presence of neighboring rods, as compared to the incurrent into a single fuel rod immersed in an infinite moderator. Alternatively, this factor can be viewed as the probability that a neutron emerging from the surface of a fuel rod will enter another fuel rod without any collision in the moderator or cladding. For perfectly absorbing fuel these definitions are equivalent. In the last years, several works appeared in literature reporting improvements in the calculation of Dancoff factors, using both the classical and the collision probability definitions. In this work, we step further reporting Dancoff factors for perfectly absorbing (Black) and partially absorbing (Grey) fuel rods calculated by the collision probability method, in cluster cells with square outer boundaries. In order to validate the results, comparisons are made with the equivalent cylindricalized cell in hypothetical test cases. The calculation is performed considering specularly reflecting boundary conditions, for the square lattice, and diffusive reflecting boundary conditions, for the cylindrical geometry. The results show the expected asymptotic behavior of the solution with increasing cell sizes. In addition, Dancoff factors are computed for the Canadian cells CANDU-37 and CANFLEX by the Monte Carlo and Direct methods. Finally, the effective multiplication factors, k{sub eff}, for these cells (cluster cell with square outer boundaries and the equivalent cylindricalized cell) are also computed, and the differences reported for the cases using the perfect and partial absorption assumptions. (author)

  12. Radiation therapy for the treatment of feline advanced cutaneous squamous cell carcinoma; A utilizacao da radioterapia no tratamento do carcinoma de celulas escamosas cutaneo felino avancado

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, S.C.S.; Corgozinho, K.B.; Ferreira, A.M.R, E-mail: simonecsc@gmail.com [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Carvalho, L.A.V. [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), RJ (Brazil); Holguin, P.G.

    2014-02-15

    The efficacy of radiation therapy for feline advanced cutaneous squamous cell carcinoma was evaluated. A full course radiation therapy protocol was applied to six cats showing single or multiple facial squamous cell carcinomas, in a total of seven histologically confirmed neoplastic lesions. Of the lesions, one was staged as T{sub 1}, and six as T{sub 4} according to WHO staging system of epidermal tumors. The animals were submitted to twelve radiation fractions of 4 Gy each, on a Monday-Wednesday-Friday schedule, and the equipment used was an orthovoltage unit. Energy used was 120 kV, 15 mA and 2 mm aluminum filter. The cats were evaluated during the treatment and 30 and 60 days after the end of the radiation therapy. In this study, 87% of the lesions had complete remission and 13% partial remission to the treatment. Side effects were considered mild according to Veterinary Radiation Therapy Oncology Group Toxicity criteria, and included erythema, epilation and rhinitis. Radiation Therapy was considered safe for feline cutaneous squamous cell carcinoma, leading to mild side effects and can represent a good therapeutic option. (author)

  13. Synthesis of human prolactin in Chinese hamster ovary (CHO) cells; Sintese de prolactina humana em celulas de ovario de hamster chines (CHO)

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Carlos Roberto Jorge

    2000-07-01

    Three different eukaryotic expression vectors, based on the same selectable gene marker (dhfr), have been used for dhf- CHO cells transfection to rapidly isolate stable cell lines capable of secreting high levels of recombinant human prolactin (rec-hPRL). Two vectors, one codifying a human prolactin (p658-hPRL) and the other a tag-prolactin (p658-tagPRL), contain the complete hepatitis B virus-X (HBV-X) gene coding for a viral transactivator and a sequence derived from the granulocyte-macrophage colony-stimulating factor (GM-CSF) that mediates selective dhfr mRNA degradation. These vectors have the advantage of rapidly obtaining stable cell lines without methotrexate amplification. The highest secretion obtained by these vectors was of approximately 10 {mu}g hPRU10{sup 6} cells/day. The other vector (pEDdc-hPRL) is based on a dicistronic expression system, containing an internal ribosome entry site isolated from the encephalomyocarditis (EMC) virus. This vector before amplification provided secretion levels at least 10 fold lower than that obtained with the other two vectors. However, after three steps of methotrexate amplification, it provided some clones able to secrete up to 30 {mu}g hPRU10{sup 6} cells/day. This is the first report describing the production and purification of rec-hPRL from CHO cells, obtaining secretion levels with both vectors higher than those reported so far for this hormone in other eukaryotic systems. CHO-derived rec-hPRL contained approximately 10 % of the glycosylated form, a value that is consistent with results reported for hPRL purified from the pituitary or from transformed murine C-127 cells. CHO-derived rec-hPRL was purified with good yield, obtaining also a good resolution between non-glycosylated and glycosylated prolactin. The latter, when its potency was determined via an in vitro bioassay, presented a 47 % lower bioactivity. A qualitative and quantitative analysis of these forms was also possible thanks to the setting up of a reversed-phase HPLC technique, for the first time applied to this hormone. A pilot production in a hollow fiber bioreactor provided a highly concentrated medium, though with the presence of considerable amounts of hPRL{sub 11-199} fragments, apparently the result of a proteolytic process. (author)

  14. Dimensional analysis system for fuel elements experience in hot cells plate format; Sistema de analise dimensional para ensaios de elementos combustiveis em forma de placas em celulas quentes

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Orozimbo J.; Dutra Neto, Aimore [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Campos, Tarcisio P.R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Dias, Ailton F. [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao Geral de Informatica

    2002-07-01

    This paper describes a system for visual and dimensional analysis of compact-core reactors fuel elements in plate format. The system, composed of a co-ordinated x, y, z computerized table, has to be operative inside of a hot cell for the visual inspection and dimensional measurements of the post irradiated fuel elements. The control method of the x, y, z table axes, the data acquisition and the process control technique using computer, are described. Experimental data handling and the expected future of the project are presented and commented. This work expand previous investigations on a dimensional analysis system carried out by Brazilian Navy Technological Center in Sao Paulo (CTMSP). (author)

  15. Adhesive market develops new technologies. The thin-film solar cells gain ground; El mercado de adhesivos desarrolla nuevas tecnologias. Las celulas solares de capa fina ganan terreno

    Energy Technology Data Exchange (ETDEWEB)

    Kluke, M.

    2010-07-01

    The solar industry is booming. thin-film technology is experiencing a high demand as promised cost advantages and currently is providing excellent results, while a range of efficiency reaches acceptable. (Author)

  16. Stem Cells and Blood: Where have we come from... and where are we going?; Celulas Madre y sangre: De donde venimos y... donde vamos a parar

    Energy Technology Data Exchange (ETDEWEB)

    Bueren, J. A.

    2011-07-01

    Since 1961, they year when the first trial that characterized the behaviour of a stem cell in mice exposed to high doses of radiation was described, research in this field has proceeded at an unpredictable place. Knowledge of the function of hematopoietic stem cells which are responsible for forming blood cells facilitated the development of therapies based on the transplant of bone marrow and other cell source, e. g. blood from the umbilical cord. These breakthroughs, together with the progress of molecular biology and virology, made it possible to manipulate the genome of hematopoietic stem cells so effectively and safely that the transplant of genetically modified cells has become a variable therapeutic alternative for the treatment of certain genetic diseases and also cancer. This brief article describes some of the contributions that our Hematopoiesis and Gene Therapy Division of the CIEMAT and the CIBER for Rare Diseases has been developing in this fascinating field of stem cells and gene therapy, in the context of the international research being carried out in this area. (Author) 34 refs.

  17. Interacción de leucocitos humanos con la proteína de matriz extracelular fibronectina : regulación y función de la integrina [alfa]4[beta]1

    OpenAIRE

    Sánchez Aparicio, Paloma

    1994-01-01

    Las interacciones celula-celula y celula-matriz extracelular son importantes para la función general de las células. La interacción de los leucocitos con la matriz extracelular (mec) es esencial para la migración, localización en tejidos, desarrollo y función de estas células esta tesis se centra en el estudio de la interaccion de los leucocitos humanos con la proteina de mec fibronectina (fn), asi como en el análisis de uno de sus receptores celulares, la integrina alfa4 beta1. En este conte...

  18. Estudo do efeito anti-apoptótico do monóxido de carbono: comunicação neurónios-astrócitos por modelação da sinalização purinérgica

    OpenAIRE

    Alves, Raquel Maria Azeitão, 1986-

    2011-01-01

    A hipoxia isquemia e reperfusao leva a lesoes cerebrais graves que rapidamente culminam na morte das celulas neuronais. O monoxido de carbono tem vindo a ser estudado como molecula neuroprotectora e, em pequenas concentracoes, confere proteccao contra a apoptose em diversos tipos de celulas e tecidos. Neste trabalho, propusemo-nos evidenciar a capacidade modeladora do CO, explorando a comunicacao celular e o trafego metabolico entre neuronios e astrocitos apos o pre-condicionamento de astroci...

  19. Evaluation of the radio modifier effect of propolis on chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with 60-CO; Avaliacao do efeito radiomodificador da propolis em celulas de ovario de hamster chines (CHO-K1) e em celulas tumorais de prostata (PC3), irradiadas com CO-60

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Geyza Spigoti

    2011-07-01

    In the last decades, it has been given a great interest to investigations concerning natural, effective, nontoxic compounds with radioprotective potential together with the increasing utilization of different types of ionizing radiation for various applications. Among them propolis, a resinous compound produced by honeybees (Apis mellifera), has been considered quite promising, since it presents several advantageous biological characteristics, i. e., anti-inflammatory, antimicrobial, anticarcinogenic, antioxidant and also free radical scavenging action. The purpose of the present study was to evaluate the effect of Brazilian propolis, collected in the State of Rio Grande do Sul, on Chinese hamster ovary (CHO-K1) and human prostate cancer (PC3) cells, irradiated with {sup 60}Co {gamma} radiation. For this purpose, three interlinked parameters were analyzed: micronucleus induction, cell viability and clonogenic death. The choice of these parameters was justified by their biological significance, in addition to the fact that they are readily observable and measurable in irradiated cells. The cytogenetic data obtained showed a radioprotective effect of propolis (5-100 {mu}g/ml) in the induction of DNA damage for both cell lines, irradiated with doses of 1 - 4 Gy. The cytotoxicity assay, however, showed a prominent antiproliferative effect of propolis (50 - 400{mu}/ml) in PC3 cells irradiated with 5 G{gamma}. The survival curves obtained were adequately fitted by a linear-quadratic model, where the {alpha} coefficient was higher in CHO-K1 cells. Concerning the clonogenic capacity, PC3 cells were more radiosensitive than CHO-K1 cells at the higher doses of the survival curve. Propolis at the concentrations of 30 - 100 {mu}g/ml, did not influence the clonogenic potential of PC3 cells, since the survival curves, associated or not with propolis, were found similar, although the combined treatment in CHO-K1 cells exhibited a stimulating proliferative effect. The data obtained in vitro showed a potential use of propolis AF-08, a natural and nontoxic compound, in the prevention against the adverse effect of ionizing radiation, at the doses and concentrations here analyzed. (author)

  20. Effects on the work of a direct ethanol fuel cell as function of compacting force applied to the cell; Efeitos no funcionamento de uma celula a combustivel com alimentacao direta de etanol (CCADE) em funcao da forca de compactacao aplicada a celula

    Energy Technology Data Exchange (ETDEWEB)

    Belchior, P.M.; Forte, M.M.C. [UFRGS - Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Serafin, R.; Fusiger, V.; Carpenter, D. [FURB - Fundacao Universidade Regional de Blumenau, SC (Brazil)

    2010-07-01

    This experiment aimed to verify the influence due to the variation of the compacting force applied to a DEFC. According to the tests, as the increase of cell compacting, the performance improves significantly. According applied tests, when the high electrical conductivity components are used, small differences of the cell compacting can generate a large difference on the total ohmic resistance. Through the tests one can conclude that with the increase of cell compacting, the contact probably increase among the distribution of reagents and the diffuser layer, improving the cell performance. (author)

  1. Aislamiento y función de células progenitoras endoteliales de sangre periférica durante la evolución clínica de pacientes con infarto agudo de miocardio. Efecto de las micropartículas Shh+ en la función celular

    OpenAIRE

    Bueno Betí, Carlos

    2015-01-01

    Las células endoteliales (CE) recubren el interior de los vasos sanguíneos constituyendo el endotelio, actualmente considerado un órgano muy activo e implicado en la regulación del tono vascular, el tráfico de células sanguíneas, el equilibrio hemostático, la permeabilidad, la proliferación, la supervivencia, y la respuesta inmunitaria tanto adaptativa como innata. Los factores de riesgo cardiovascular como la hipercolesterolemia, la diabetes y el tabaquismo pueden causar lesiones endoteliale...

  2. Estratégias de tratamento da leucemia linfóide crônica recidivada ou resistente incluindo o transplante de célula progenitora hematopoiética Strategies of treatment for relapsed or resistant chronic lymphocytic leukemia including to hematopoietic progenitor cell transplantation

    Directory of Open Access Journals (Sweden)

    Cármino A. Souza

    2005-12-01

    Full Text Available Apesar dos importantes progressos terapêuticos, a leucemia linfóide crônica (LLC, a mais comum leucemia do adulto nos países ocidentais, permanece incurável. A utilização da fludarabina isolada ou associada à ciclofosfamida e/ou antraciclínicos elevou de maneira importante as respostas objetivas, inclusive com a obtenção de respostas completas (até mesmo moleculares e as sobrevidas livres de progressão e de recidiva. Alguns autores sugerem a introdução de anticorpos monoclonais para elevar ainda mais estes resultados. Apesar disto, todos os pacientes tratados devem apresentar recidiva ou progressão da LLC e tratamento de salvamento deve ser instituído. No presente momento, as estratégias de tratamento de salvamento são muito semelhantes às disponíveis para o tratamento de primeira linha. Os critérios para se iniciar o tratamento de salvamento são semelhantes aos definidos pelo NCI (National Cancer Institute para o primeiro tratamento. Assim, a utilização de fludarabina, isolada ou associada, deve ser a terapêutica de escolha para os pacientes recidivados, mesmo que tenham sido previamente tratados com fludarabina como primeira linha. A utilização de anticorpos monoclonais, particularmente o rituximab, é desejável nesta segunda tentativa, mesmo que não se possa dizer ainda que esta indicação seja formal. O alemtuzumab é um anticorpo monoclonal muito eficiente e tem mostrado ter a capacidade de promover importantes benefícios clínicos e hematológicos, mesmo em pacientes "pesadamente" tratados ou mesmo refratários à fludarabina. O TCPH tem indicações limitadas tendo em vista os riscos da terapia de alta dose em pacientes que são, geralmente, idosos. Assim, o transplante autólogo pode ser indicado em pacientes jovens, preferentemente em remissão completa, no sentido de prolongar a sobrevida livre de progressão. Os transplantes alogênicos, convencional ou de intensidade reduzida, podem ser utilizados em pacientes com doador HLA idêntico, preferentemente mais jovens (Despite much progress in therapy, chronic lymphocytic leukemia, the most common leukemia in the Western world, remains incurable. The use of fludarabine alone or associated to cyclophosphamide and/or mitoxantrone or doxorubicin improved the objective response, including complete response (also molecular and the progression- and relapse-free-survival. Several authors have suggested the introduction of monoclonal antibodies in order to improve the results. Despite that, all treated patients will further relapse or progress and salvage treatment should be used. In the present state-of-the art, salvage treatment is similar to those used as front line therapy. Indeed the criteria to start treatment are the same as defined by NCI for the front line therapy. Fludarabine alone or associated should be the therapy of choice for relapsed patients also for those previously treated with fludarabine. The use of monoclonal antibodies particularly rituximab is a good option although this procedure has not been considered as the standard therapy until now. Alemtuzumab is a very efficient monoclonal antibody and promotes significant benefits in clinical and hematological responses also in heavily treated or fludarabine refractory patients. The HPCT has limited indication due to the risks of high dose therapy in elderly patients. Autologous HPCT may be used specifically in young patients, if possible in complete remission, in order to improve the progression- or disease-free-survival. Conventional or with reduced intensity allogeneic HPCT may be used in patients presenting with a sibling donor particularly those under 60 years old, in fludarabine refractory patients or in patients presenting with unfavorable cytogenetics (17p-, with a curative objective.

  3. [Therapeutic potential of bone marrow stem cells in cerebral infarction].

    Science.gov (United States)

    Sánchez-Cruz, Gilberto; Milián-Rodríguez, Lismary

    2015-05-16

    Introduccion. Las celulas madre constituyen una alternativa terapeutica que se encuentra en fase de experimentacion para el infarto cerebral. Objetivo. Mostrar la evidencia cientifica existente sobre el potencial terapeutico de las celulas madre de la medula osea en esta enfermedad. Desarrollo. El infarto cerebral representa el 80% de las enfermedades cerebrovasculares. La trombolisis constituye la unica terapia aprobada, pero, por su estrecha ventana terapeutica, solo se aplica a un bajo porcentaje de los pacientes. De manera alternativa, los tratamientos neurorrestauradores, como el de celulas madre, pueden aplicarse en periodos mas prolongados. Por esta razon se efectuo una busqueda bibliografica en PubMed con el empleo de las palabras clave 'stem cells', 'bone marrow derived mononuclear cells' y 'stroke'. Se encontraron evidencias de seguridad y eficacia de dichas celulas en diferentes momentos evolutivos del infarto cerebral. Se identificaron estudios que en clinica y preclinica las recolectaron por puncion medular y en sangre periferica, y las trasplantaron directamente en el area infartada o por via intravascular. El efecto terapeutico se relaciona con sus propiedades de plasticidad celular y liberacion de factores troficos. Conclusiones. El concentrado de celulas mononucleares autologas, obtenido en sangre periferica o por puncion de la medula osea, y trasplantado por via intravenosa, es una factible opcion metodologica que permitira rapidamente incrementar el numero de ensayos clinicos en diferentes etapas evolutivas del infarto cerebral. Esta terapia muestra seguridad y eficacia; sin embargo, deben ampliarse las evidencias que avalen su generalizacion en humanos.

  4. [Erythropoietin as a protective factor in rat CNS cells receiving radiotherapy -an in vitro study].

    Science.gov (United States)

    Gomez-De la Riva, Álvaro; Isla-Guerrero, Alberto; García-Grande, Antonio

    2014-03-01

    Objetivo. Investigar el efecto de la eritropoyetina en cultivos celulares de corteza cerebral de ratas cuando se administra radioterapia. Materiales y metodos. El estudio se desarrolla con la obtencion de corteza cerebral de embriones de 17 dias de preñez de ratas Wistar. Las celulas cultivadas despues de 72 horas de la extraccion de la corteza se dividieron en dos grupos, a uno de ellos se le administro eritropoyetina alfa a una concentracion de 30 pM y el otro era el grupo control. A los dos grupos de celulas se les radio con 6 Gy mediante un aparato Phoenix. Tras la radioterapia permanecieron 24 horas en la incubadora antes de fijarlas. Las celulas fueron fijadas con formaldehido al 4%. A continuacion, con la tecnica de TUNEL, se valoro el numero de celulas apoptoticas en los cultivos radiados. Resultados. Se observo un porcentaje de apoptosis del 25,22% del grupo de cultivo sin eritropoyetina, mientras que en el grupo de celulas radiadas con eritropoyetina fue del 15,5%. Las variables cuantitativas se analizaron mediante el test t de Student y el resultado de la comparacion entre los dos grupos fue estadisticamente significativo (p sistema nervioso central de ratas por radiacion. Esto abre nuevos campos para la investigacion del efecto protector del sistema nervioso.

  5. Células madre y terapia celular

    Directory of Open Access Journals (Sweden)

    Elso Manuel Cruz Cruz

    2015-03-01

    Full Text Available Una célula madre (CM o célula troncal es aquella capaz de dividirse indefinidamente y diferenciarse a distintos tipos de células especializadas, no sólo morfológica sino también funcionalmente. Las células madre pueden clasificarse atendiendo a su origen en células madre adultas (CMA y células madre embrionarias (CME. Por sus características, las CM tienen potencialidades para diversos usos en la práctica clínica. La primera es como vehículo terapéutico de genes, en el caso de enfermedades monogénicas o incluso como vehículo de terapias antitumorales o antiangiogénicas. La segunda y principal aplicación es, aprovechando su potencial de diferenciación, en la regeneración de tejidos destruidos o dañados, como terapia de reemplazo celular o medicina regenerativa. En esta área se están desarrollando trabajos de investigación donde se busca reemplazar células dañadas por otras que restituyan la función normal de los tejidos u órganos; en enfermedades como: diabetes mellitus, enfermedades cardiovasculares, enfermedad de Parkinson y enfermedades de células sanguíneas. Actualmente existen muchas investigaciones enfocadas a descubrir células progenitoras que sirvan como banco de células para usos terapéuticos. Se reporta el empleo de varias estrategias, las que incluyen: terapias celulares derivadas de células autólogas; terapias celulares derivadas de líneas celulares establecidas desde una variedad de CM que incluyen MO, cordón umbilical, CME, así como células de tejidos y órganos de animales genéticamente modificados. Las principales aplicaciones se realizan con CM de la médula ósea (MO, ya que esta es un recurso celular propio, accesible y abundante para la terapia celular. (1 En la MO existe un grupo heterogéneo de CMA; además de las hematopoyéticas (CMH están las: endoteliales, mesenquimales (CMM, de la población lateral, progenitoras adultas multipotentes, ovales y también células madre muy peque

  6. Enfermedades potenciales derivadas de factores de riesgo presentes en la industria de producción de alimentos Potencial diseases arising from occupational hazards in the food production industry

    Directory of Open Access Journals (Sweden)

    Mónica Sánchez Aguilar

    2011-12-01

    Full Text Available La industria de la producción de alimentos presenta factores de riesgo laborales que van de los químicos hasta los psicosociales, por lo mismo los grupos de enfermedades que potencialmente se vinculan con ellos pueden ser aparentemente inocuas o poner en riesgo la vida del trabajador, lo que evidencia la necesidad de contar con una revisión extensa de la bibliografía nacional e internacional de enfermedades vinculadas a los riesgos presentes en los puestos de las áreas de producción hasta los puestos de mantenimiento de la industria de los alimentos. El propósito de esta publicación es evidenciar al lector el vínculo existente entre los factores de riesgos presentes en la industria de los alimentos y las enfermedades que estos pueden generar, y que frecuentemente son calificadas como enfermedades generales cuando en realidad son laborales, y así proporcionarle fundamentos sólidos según referencias nacionales e internacionales para un diagnóstico situacional y de salud más completo. Objetivos: Esta revisión pretende evidenciar el vínculo existente entre los factores de riesgos presentes en la industria de los alimentos y las enfermedades que pueden generarse a consecuencia de estos. Material y Método: Se han revisado hasta Diciembre de 2009 las siguientes bases de datos bibliográficas: Medline, SciELO, y PUBMED. Conclusiones: Un diagnóstico a fondo de enfermedades de presunto origen ocupacional implica el conocimiento y reconocimiento absoluto de los factores de riesgo laborales a los que se exponen los trabajadores diariamente o eventualmente, así como identificar rápidamente los efectos a la salud reales y potenciales de estos factores por parte de todos los responsables, directos e indirectos, de salud ocupacional al interior de los centros de trabajo.The industry of foods production presents occupational hazards that go from chemicals to psychosocial, because of that the groups of diseases that potentially been linked with them can be apparently harmless put in risk the life of the worker, which shows the need to have an extensive review of national and international bibliography of diseases linked with the risks presents in positions of production areas to maintenance positions of food industry. The propose of this publication is make evidence to the reader the link that exist between the risks factor presents in the food industry and the diseases that this can provoke, and frequently been qualified as general diseases when really are work related diseases, and thus provide solid foundations according national and international references for a situational diagnostic and health more complete. Objectives: This review aims to show the link between risk factors presents in food industry and the diseases that may occur as a result of them. Material and Methods: Have been revised to December 2009 the next bibliographic data bases: Medline, SciELO and PUBMED. Conclusions: A thorough diagnosis of diseases of presumptive occupational origin implies knowledge and full recognition that the workers been exposed every day or eventually, as well as quickly identify the real effect to the health and potential effect of these hazards by all those responsive for, direct and indirect, of occupational health within work centers.

  7. En defensa de las actitudes y emociones en la educación científica (ii): evidencias empíricas derivadas de la investigación

    OpenAIRE

    Vázquez Alonso, Ángel; Manassero–Mas, María Antonia

    2007-01-01

    El currículo, los materiales didácticos y las prácticas de enseñanza y aprendizaje de la educación científica tradicional abusan de los dos factores epistémicos sugeridos por el positivismo lógico, la referencia empírica y el razonamiento lógico, junto con su epítome el lenguaje matemático, que sostienen la verdad y la objetividad como valores esenciales de la ciencia. La consecuencia más notable de esta abusiva orientación positivista es la exclusión, implícita y explícita, de...

  8. Impacto de las actividades antrópicas derivadas de la industria petrolera en relación con la presencia de metales pesados en la ganadería bovina colombiana

    Directory of Open Access Journals (Sweden)

    JJ Bustamante

    2015-01-01

    Full Text Available La región del Magdalena medio es una zona de actividad industrial-minera con exploraciones y refinación de hidrocarbur os. Por ello los animales que viven en esta área geográfica son afe ctados por la presencia de contaminante s, especialmente metales pesado s. En este trabajo se estudiaron 40 animales adultos, sacrificados en el matadero de Barrancabermeja, procedentes de explotaciones bovinas cercanas a industrias con actividad petrolífera. Se det erminó la presencia de plomo, cadmio, molibdeno y zinc en hígado, riñó n, músculo y piel mediante espectro fotometría de absorción atómica y se compararon los resultados obt enidos con los límites máximos permisibles establecidos por la Unión Europea y el Codex Alimentarius [1,2]. Se encontró mayor concentración de todos lo s metales en Barrancabermeja excepto el Zn que presentó mayores niveles en Yondó. Un núm ero importante de mue stras hepáticas (9 0 y 50%, renales (75 y 15% y musculares (85 y 90% de ambas localizaciones superaron los valores permisibles de Pb tanto de l Codex Alimentarius, como de la U nión Europea. Situación similar sucede con el Cd en Barrancabermeja, superando en el 85%, el 10 % y la totalidad (100% los valores permitidos por la Unión Europ ea en hígado, riñón y músculo respectivamente, mientras que en Yondó, 65% de las muestras hepáticas y todas las muestras musculares superan esos mismos límites. Por ello podemos conclu ir que el consumo de carne y vísce ras de bovinos que pastorean en el Magdalena Medio Colombiano, rep resenta un grave riesgo para la salud humana como consecuencia de su alto grado de contaminació n con metales pesados.

  9. Condiciones físicas de formación de gabros ymigmatitas derivadas de rocas máficas en el centro de la Sierra de ValleFértil, San Juan

    Directory of Open Access Journals (Sweden)

    AlinaM. Tibaldi

    2009-11-01

    Full Text Available A lo largo del arroyo San Juan en el sector central dela sierra de Valle Fértil aflora una sección cortical caracterizada por lapresencia de rocas plutónicas máficas interestratificadas con migmatitasmáficas y migmatitas metasedimentarias. Esta relación de campo permite observarla transición de procesos ígneos a metamórficos asociados con la cristalizaciónde magmas máficos y la subsiguiente fusión parcial de rocas gábricas. Esteestudio analiza los cambios en la asociación y composición de minerales queocurrieron durante esa transición petrológica. Las estimacionestermo-barométricas realizadas usando el par anfíbol-plagioclasa en las rocasígneas máficas indican que los magmas cristalizaron a aproximadamente 1100 ºC yen un rango de presiones de 5 ± 0,5 kbar. En tanto que las condiciones físicasde formación estimadas mediante el intercambio de Fe-Mg entre dos piroxenos yel termómetro anfíbol-plagioclasa en mesosomas de migmatitas máficas demuestraque las rocas gábricas experimentaron un procesos de fusión parcial entre770-840ºC y 5,5 kbar y que los leucosomas leucotonalíticos generados a partirdel mismo proceso cristalizaron entre 780-820ºC y entre 5 y 6,5 kbar. Loscambios en la composición de minerales que acompañaron a la fusión parcial derocas gábricas son: 1 disminución en la concentración de aluminio y Mg# de lospiroxenos, 2 decrecimiento del contenido de anortita en plagioclasa, y 3disminución del Mg# en el anfíbol. El ejemplo natural estudiado presentacambios mineralógicos que son consistentes con los resultados de petrologíaexperimental, los cuales demuestran que protolitos ígneos máficos comienzan afundir parcialmente a 850ºC cuando la fusión es impulsada por deshidratación deanfíbol, o que la fusión comenzaría alrededor de los 800ºC cuando se incorporaun fluido acuoso al sistema. Integrando relaciones de campo, cambiostexturales, composición de minerales, termo-batometría con resultadosexperimentales se demuestra que la transición desde rocas ígneas máficas amigmatitas máficas ocurrió por enfriamiento isobárico, y que el emplazamientocontinuo de magmas debió ser la fuente de calor que mantuvo la secuencia enfacies de granulitas sin dejar que el enfriamiento fuera rápido. Se interpretala geología del centro de la sierra de Valle Fértil como un ejemplo del núcleoplutónico-metamórfico del arco magmático Famatiniano donde el gradientemetamórfico anormalmente alto refleja que un volumen importante de magmasmáficos alcanzaban, y dominaban, en paleo-profundidades de entre 16 y 20kilómetros.

  10. Caracterización de las células supresoras derivadas de mieloides como nuevos agentes inmunomoduladores endógenos para el tratamiento de la esclerosis múltiple

    OpenAIRE

    Moliné Velazquez, Verónica María

    2013-01-01

    Tesis doctoral inédita, leída en la Universidad Autónoma de Madrid. Facultad de Medicina. Departamento de Anatomía, Histología y Neurociencia. Tesis realizada en el Hospital Nacional de Parapléjicos. Fecha de lectura: 19 de Abril de 2013

  11. The sexual and reproductive health of young people in Latin America: evidence from WHO case studies La salud sexual y reproductiva de los jóvenes en América Latina: evidencia derivada de estudios de la OMS

    Directory of Open Access Journals (Sweden)

    Kate Kostrzewa

    2008-02-01

    Full Text Available This original article addresses the sexual and reproductive health needs of young people aged 15 to 24 in Latin America. It introduces five articles from original research projects in three countries: Argentina, Brazil, and Peru. These projects were funded by the World Health Organization. This article explains the importance of studies that address the sexual and reproductive health of young people in developing countries. It provides an overview of sexual and reproductive health issues in Latin America and a discussion these issues in the three study countries. The five articles deal with difficult and challenging issues, including: knowledge of STIs and HIV/AIDS; pregnancy related practices; quality of care; the role of young men in couple formation, pregnancy and adoption of contraceptive practice; and, the role of obstetricians and gynecologists in public policy debate about family planning and abortion. The four articles in this special section help to improve our understanding of the factors that contribute to risky sexual behavior and negative reproductive health outcomes among youth in Latin America. The findings are useful to help inform and improve health care interventions in various contexts.Este artículo original trata de las necesidades de salud sexual y reproductiva de jóvenes entre 15 y 24 años de edad en América Latina. Se presentan cuatro artículos derivados de investigaciones originales en tres países: Argentina, Brasil y Perú. Estos proyectos fueron patrocinados por la Organización Mundial de la Salud. Este artículo elucida la importancia de los estudios que tratan de la salud sexual y reproductiva de jóvenes en países en desarollo. Se ilustra el panorama general en cuestiones de salud sexual y reproductiva en América Latina y una discusión de estas cuestiones en los tres países de donde provienen los estudios. Los cinco artículos discuten cuestiones difíciles y controversiales, como los conocimientos sobre ITS y VIH/SIDA; las prácticas asociadas con el parto; la calidad de cuidados; el papel de los hombres jóvenes en la formación de parejas, el embarazo y el uso de métodos anticonceptivos; así como el papel de los tocólogos y ginecólogos en el debate público sobre planificación familiar y aborto. Los cuatro artículos en esta sección especial promueven un mejor entendimiento de los factores que contribuyen a las conductas sexuales de riesgo y a los resultados negativos en salud reproductiva entre los jóvenes en América Latina. Las conclusiones son útiles para informar y mejorar intervenciones de servicios de salud en contextos varios.

  12. Synthesis and characterization of particles derived of poly(vinyl alcohol) (PVA) for treatment of embolization and chemoembolization;Sintese e caracterizacao de particulas derivadas de poli(alcool vinilico) (PVA) para embolizacao e quimioembolizacao

    Energy Technology Data Exchange (ETDEWEB)

    Semenzim, Vinicius L.; Basso, Glaucia G.; Passos, Rodrigo A.; Nery, Jose G. [UNESP, Sao Jose do Rio Preto, SP (Brazil); Agreli, Guilherme; Oliveira, Ana P.M.L.; Kawasaki-Oyama, Rosa S.; Braile, Domingo M., E-mail: nery@ibilce.unesp.b [Braile Biomedica Industria e Comercio Representacoes S.A., Sao Jose do Rio Preto, SP (Brazil)

    2009-07-01

    The most effective way to treat cancerous tumors is by surgically removing them. However in some types of cancer, such as liver and uterine cancer, more than two-thirds of patients have no indication for surgery due to the size and location of the tumor, such as into the blood vessels. Doctors and researchers have invested in alternative and less invasive methods such as chemoembolization. The objectives of this research project are the synthesis and characterization of poly(vinyl alcohol) (PVA) particles for use in cancer treatment. PVA particles will be combined with chemotherapeutic agent Doxorubicin, drug commonly used in the treatment of cancers and carcinomas. The particles, obtained by controlled polymerization reaction followed by saponification, were characterized by SEM, XRD and NMR-CP/MAS. The functionalization of the particles with the drug is the next step of this study. (author)

  13. Experimental and theoretical study of the reduction of Schiff bases derived from 3,3-diphenylpropylamine; Estudo experimental e teorico da reducao de bases de Schiff derivadas da 3,3-difenilpropilamina

    Energy Technology Data Exchange (ETDEWEB)

    Esteves-Souza, Andressa; Echevarria, Aurea; Sant' Anna, Carlos Mauricio R. [Universidade Federal Rural do Rio de Janeiro, RJ (Brazil). Dept. de Quimica; Nascimento, Maria da Graca [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Quimica]. E-mail: echevarr@ufrrj.br

    2004-02-01

    A series of seven Schiff bases have been synthesized from 3,3-diphenylpropylamine and substituted benzaldehydes. These imines were treated with NaBH{sub 4} in ethanol affording the corresponding amines in 98-55% yields. A molecular modeling study was performed with the Schiff bases in order to compare the theoretical parameters with the experimental results. The theoretical parameters were obtained by AM1 and PM3 semi-empirical methods. The analysis of charge, electron densities and LUMO coefficients suggested that the most favorable interactions should occur with Schiff bases containing electron donating groups, in accordance with experimental yields, showing that the higher reactivity is due to higher electrophilic character of imine carbons. (author)

  14. Análise nutricional e complementação alimentar de cesta básica derivada do consumo Nutritional analysis and complementation of a food basket derived of the consumption

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    Sérgio A. J. Barretto

    1998-02-01

    Full Text Available INTRODUÇÃO: A "cesta básica Dieese e Procon", originada de uma Pesquisa de Padrão de Vida e Emprego no Município de São Paulo, tem sido empregada como parâmetro para o acompanhamento de preços. Seria desejável que um instrumento econômico, utilizado com esta finalidade, correspondesse também a uma nutrição efetivamente saudável. Assim, foram analisados os níveis de adequação dos itens alimentares da cesta básica em relação às necessidades nutricionais de uma família-referência paulistana, e propostas técnicas de complementação dietética para sanar possíveis deficiências ou desbalanceamento. METODOLOGIA: Utilizou-se o Censo Demográfico do IBGE, de 1991, para se determinar a família-referência; adotaram-se dois terços das "Recommended Dietary Allowances" como parâmetro de necessidades nutricionais; e utilizou-se das tabelas de composição centesimal para verificação do aporte de nutrientes da cesta básica. Efetuou-se a complementação alimentar por meio de três diferentes métodos: Ad Hoc (proposta direta e fixa, Programação Linear (proposta via computador e sazonal, com ênfase na minimização de custos, Híbrido (uma combinação dos dois anteriores. RESULTADOS: Foram encontrados valores insuficientes para as vitaminas A, C, B2 e B6 e para os minerais Ca, Mg, Fe, Zn, I e Se; o percentual de lipídios no total calórico mostrou-se elevado. Entre as técnicas de complementação, o método Híbrido pareceu assimilar, mais eficientemente, os baixos custos e os hábitos dietéticos. DISCUSSÃO: Inferiu-se uma eventual correspondência entre os problemas nutricionais detectados na relação de itens da cesta básica e a chamada transição alimentar que se processa nos países em desenvolvimento. Não parece aconselhável que os riscos epidemiológicos associados a essa alteração nos padrões dietéticos sejam incorporados num instrumento econômico que tenha por finalidade mensurar os preços de uma alimentação equilibrada.INTRODUCTION: The Dieese & Procon Basket (DPB is a list of basic foodstuffs, drawn up on the basis of a Standard of Living and Work Research project in S. Paulo city, Brazil. Seeing that it has been used as a standard for price variations, it is desirable that such an economic instrument as this, should also represent a truly healthy standard of nutrition. Thus, this study seeks to verify the adequacy of the food products in the DPB in relation to the nutritional needs of a typical reference family in S. Paulo city. It also proposes some techniques for dietary complementation. METHODOLOGY: A demographic census, undertaken in 1991 has been used to establish the reference family, as well as 2/3rds of RDA as corresponding to its nutritional needs, and the food composition tables of McCance & Widdowson to analyse the nutrient content of the DPB. Dietary complementation were undertaken by three different methods: Ad Hoc (direct suggestions, Linear Programming (computer software was utilized to minimize costs, and Hybrid (a combination of the first two. RESULTS: Food items in the DPB showed insufficient values for vitamins A, C, B2 and B6, and for minerals Ca, Mg, Fe, Zn, I and Se; besides, a relatively high fat content was found. The Hybrid Method of food complementation seems to present the best results, associating low cost and local dietary habits. DISCUSSION: A relation between the dietary deficiencies of the DPB and the nutritional transition in the developing countries may be infered. The epidemiological risks associated with these changes in eating patterns should not be incorporated into a reliable economic instrument.

  15. Síntese e avaliação da atividade fitotóxica de lactonas derivadas do 2,4-dimetil-8-oxabiciclo[3.2.1]-oct-6-en-3-ona

    Directory of Open Access Journals (Sweden)

    Barbosa Luiz Cláudio de Almeida

    2002-01-01

    Full Text Available The alkene 2,4-dimethyl-8-oxabicyclo[3.2.1]-oct-6-en-3-one (3 was converted to 1,3,10-trimethyl-8-oxabicyclo[5.3.0]-dec-3-ene-2,9-dione (7 and 1,3-dimethyl-8-oxabicyclo[5.3.0]-dec-3-ene-2,9-dione (8 with a 55% overall yield in both cases. Lactones (7 and (8 were converted in two steps to 1,3,4-trimethyl-13-methylene-6-oxatricyclo[8.3.0.0(3,7]-trideca-2,5,12-trione (12 (63% and 1,3-dimethyl-13-methylene-6-oxatricycle[8.3.0.0(3,7]-trideca-2,5,12-trione (13 (45% from 8. The effect of lactones (7, (8, (12, (13 and the intermediates (5 and (6, at the concentration of 250 mug mL-1, on the growth of Cucumis sativus L. and Sorghum bicolor L. was evaluated. The best results were observed for lactone (13 that caused 100% inhibition on the root growth of C. sativus and lactone (12 that inhibited 90% of the root growth for S. bicolor.

  16. Implementation of rafts of water spillage retention in the NPP. Almaraz and Trillo. Actions arising from the ITC-2; Implantacion de balsas de retencion de vertidos liquidos en las CCNN de Trillo y Almaraz. Actuaciones derivadas de la ITC-2

    Energy Technology Data Exchange (ETDEWEB)

    Font Hadinger, I.; Fernandez Morales, E.; Lopez Hernandez, A.

    2014-07-01

    In compliance with the ITC-2 of the Consejo de Seguridad Nuclear, have been built rafts for the containment of spills potentially radiologically contaminated, produced within the NPP site. Almaraz and Trillo. These discharges would be caused by certain mitigation activities to deploy in response to events beyond the design basis related to the potential loss of large areas (large fire mitigation and spraying of gaseous emissions) and in addition in the case of CNA, by a potential leak of the SFP (Spent Fuel Pool - pool of spent fuel). The basic idea is that any liquid discharge generated by the previous reasons within the Nuclear island may be content before your arrival to the outside of the plant through its network for the disposal of rainwater. Therefore, these rafts are the barrier last contention against an uncontrolled discharge of these waters to the environment. The same design ensures compliance with all the requirements, normative and practical, ensuring containment of aforementioned wastes potential capacity. (Author)

  17. Recommendations for improving the radiation protection of medical personnel from the project Oramed European; Recomendaciones para la mejora de la proteccion radiologica del personal sanitario derivadas del proyecto europeo ORAMED

    Energy Technology Data Exchange (ETDEWEB)

    Ginjaume, M.; Ortega, X.; Carnicer, A.; Duch, M. A.; Carnou, G.; Gualdrini, G.; Clairand, I.; Sans Merce, M.; Vanhavere, F.

    2011-07-01

    In February 2011 finalized the draft of the 7th EC Framework Programme, Oramed, whose main purpose was to propose improvements in the radiation protection of medical personnel involved in radiology procedures and interventional cardiology or in the preparation and administration of radiopharmaceuticals in medicine nuclear. The Spanish participation in the project has been led by the Institute of Energy Technology at the Polytechnic University of Catalonia with the collaboration of four health centers.

  18. Avaliação por RAPD de plantas de abacaxizeiro cultivar Smooth Cayenne derivadas do seccionamento do talo e cultura de tecidos Evaluation of pineapple plants cultivar Smooth Cayenne from peduncle division and tissue culture by RAPD

    Directory of Open Access Journals (Sweden)

    MARIA VITÓRIA CECCHETTI GOTTARDI

    2002-04-01

    Full Text Available Foram coletadas, em área comercial da fazenda Córrego dos Bois, município de Canápolis -- MG, plantas de abacaxizeiro cultivar Smooth Cayenne, para serem avaliadas quanto à propagação pelo método do seccionamento do talo e cultura de tecidos, bem como análise por RAPD das mudas decorrentes destes dois processos de propagação. A propagação pelo seccionamento do talo foi eficiente na produção de mudas, tanto em quantidade como em qualidade, em um curto espaço de tempo, além de apresentar a mesma característica genotípica (análise por RAPD das plantas-matrizes de origem. Já no processo de produção de mudas por cultura de tecidos, não foi obtida uma quantidade suficiente de mudas que comprovasse a utilização de uma metodologia mais sofisticada. Além da perda por contaminação em laboratório de 70% do material em estudo, foi necessária a utilização de um longo período, aproximadamente 18 meses, para a obtenção das mudas. Na análise por RAPD das plantas decorrentes deste processo de propagação, foram observados padrões de bandas diferentes em algumas amostras, as quais podem estar relacionadas com uma possível variação somaclonal.Plants of pineapple Smooth Cayenne cultivar were collected from a commercial area, Córrego dos Bois farm, in Canápolis, state of Minas Gerais, to evaluate two different processes of propagation, peduncle division and tissue culture. These same plants were characterized by RAPD analysis. According to the two propagation method, the peduncle division was efficient in seedlings propagation, in quantity as well as in quality, at a short period of time, resulting the same phenotype and genetic characteristics (RAPD analysis from the matrix descent plants. In the tissue culture method, the quantity of seedlings obtained were not good enough that could prove the use of a sophisticated methodology. Besides loosing 70% of the material, it was necessary to expend a long period of time, at least 18 months to obtain the new seedlings. By RAPD analysis of plants obtained by tissue culture were observed different patterns in some samples, those could be related to somaclonal variation.

  19. The intensity modulated radiation therapy (IMRT) reduces rectal complications arising radiotherapy treatment of prostate cancer; La Radioterapia con modulacion de intensidad (LMRT) reduce . Las complicaciones rectales derivadas del tratamiento radioterapico del cancer prostata

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Vicente, F.; Zapatero Lobarda, A.; Rodriguez Martinez, G.; Martin de Vidales, C.; Bermudez Luna, R.; Leaman Alcibar, O.; Perez Gonzalez, L.; Cruz Conde, A.; Linan Diaz, O.; Torres Escobar, J. J.

    2013-07-01

    The objective of this analysis is to assess with adequate follow the incidence of rectal complications and know quantitatively and statistical evidence if the pattern of gastrointestinal toxicity allows us to continue with the next level of dose escalation. (Author)

  20. ESTUDOS SOBRE ABORDAGENS TERAPÊUTICAS PARA O ACIDENTE VASCULAR ENCEFÁLICO (AVE) EM MODELO ANIMAL: USO DE CÉLULAS DERIVADAS DE MEDULA ÓSSEA E DE FLAVONOIDES

    OpenAIRE

    Arthur Giraldi-Guimarães; Maria de Fátima dos Santos Sampaio; Amélia Miranda Gomes Rodrigues; Helder Teixeira de Freitas; Viviane Gomes da Silva; Fralini dos Santos Marcilio; Bárbara de Paula Coelho; Mayara de Almeida Martins Soares; Mariana Gomes Rebel

    2012-01-01

    O Acidente Vascular Encefálico é a maior causa de incapacitação em seres humanos adultos, representandoatualmente um grande custo pessoal e social. Empregando modelos experimentais de lesões cerebrais focais,este projeto tem como objetivo geral avaliar o efeito benéfico de abordagens terapêuticas promissoras notratamento do AVE e de outras lesões cerebrais. Em estudos concluídos, tivemos como objetivo principalavaliar a capacidade de indução de recuperação funcional em testes sensorimotores p...

  1. Intervención de enfermería para disminuir las complicaciones derivadas de la hospitalización en los ancianos Nursing interventions aimed at reducing complications set in the hospitalisation of the elderly

    OpenAIRE

    Ana Dolores Canga Armayor; María Jesús Narvaiza Solís

    2006-01-01

    La hospitalización en los ancianos puede llevar a pérdidas de capacidad funcional y sensorial. Pregunta de investigación: ¿Una intervención de enfermería protocolizada en ancianos que ingresan en un hospital de agudos disminuye las complicaciones de la hospitalización? Diseño: Estudio experimental con grupo control (18 casos)/intervención (13 casos) y asignación aleatoria en pacientes mayores de 70 años. Intervención protocolizada. Instrumentos de medida al ingreso y el alta: escala de compor...

  2. Estudio de la incapacidad permanente derivada de enfermedad común: principales diagnósticos, variables de persona y gestión. Estudio de la influencia de la clase social y comorbilida

    OpenAIRE

    Vaquero Abellán, Mercedes

    2009-01-01

    Falta por incorporar las palabras clave Objetivos: - Estudiar la incidencia durante un año de incapacidad laboral permanente por enfermedad común en la provincia de Sevilla. - Conocer la relación entre la incapacidad permanente y diferentes variables independientes, agrupadas según características administrativas, demográficas y socio-laborales. Estudiar la relación que existe entre incapacidad y comorbilidad. - Exponer las principales patologías que originan incapacidad y hacer un estudio...

  3. Geometria da valva mitral derivada da ressonância magnética cardiovascular na avaliação da gravidade da regurgitação mitral

    Directory of Open Access Journals (Sweden)

    Andre Mauricio Fernandes

    2013-06-01

    Full Text Available FUNDAMENTO: A regurgitação mitral é a doença valvar cardíaca mais comum em todo o mundo. A ressonância magnética pode ser uma ferramenta útil para analisar os parâmetros da valva mitral. OBJETIVO: diferenciar padrões geométricos da valva mitral em pacientes com diferentes gravidades por regurgitação mitral (RM com base na ressonância magnética cardiovascular. MÉTODOS: Sessenta e três pacientes foram submetidos à ressonância magnética cardiovascular. Os parâmetros da valva mitral analisados foram: área (mm2 e ângulo (graus de tenting, altura do ventrículo (mm, altura do tenting (mm, folheto anterior, comprimento posterior do folheto (leaflet e diâmetro do anulo (mm. Os pacientes foram divididos em dois grupos, um incluindo pacientes que necessitaram de cirurgia da valva mitral e o outro os que não. RESULTADOS: Trinta e seis pacientes apresentaram de RM discreta a leve (1-2+ e 27 RM de moderada a grave (3-4+. Dez (15,9% dos 63 pacientes foram submetidos à cirurgia. Pacientes com RM mais grave tiveram maior diâmetro sistólico final do ventrículo esquerdo (38,6 ± 10,2 vs. 45,4 ± 16,8, p < 0,05 e diâmetro diastólico final esquerdo (52,9 ± 6,8 vs. 60,1 ± 12,3, p = 0,005. Na análise multivariada, a área de tenting foi a determinante mais forte de gravidade de RM (r = 0,62, p = 0,035. Comprimento do anulo (36,1 ± 4,7 vs. 41 ± 6,7, p< 0,001, área de tenting (190,7 ± 149,7 vs. 130 ± 71,3, p= 0,048 e comprimento do folheto posterior (15,1 ± 4,1 vs. 12,2 ± 3,5, p= 0,023 foram maiores em pacientes que precisaram de cirurgia da valva mitral. CONCLUSÕES: Área de tenting, anulo e comprimento do folheto posterior são possíveis determinantes da gravidade da RM. Estes parâmetros geométricos podem ser usados para individualizar a gravidade e, provavelmente, no futuro, orientar o tratamento do paciente com base na anatomia individual do aparelho mitral.

  4. Diferenciação de células-tronco mesenquimais derivadas do tecido adiposo em cardiomiócitos Differentiation of adipose tissue-derived mesenchymal stem cells into cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Pablo Herthel Carvalho

    2012-01-01

    Full Text Available FUNDAMENTO: O potencial de renovação e proliferação dos cardiomiócitos, in vivo, é pequeno, e por isso, o músculo cardíaco apresenta limitada capacidade de repor células perdidas. Na tentativa de minimizar os danos oriundos de lesões hipóxico-isquêmicas e daquelas que acometem o sistema de condução do coração, a terapia celular com células-tronco mesenquimais (MSC vem sendo utilizada, inclusive com cardiomiócitos diferenciados a partir de MSC. OBJETIVO: O presente trabalho comparou três protocolos distintos de indução de diferenciação objetivando a sugestão de um método viável para a diferenciação de maior número de células funcionais que expressem fenótipo cardiomiogênico. MÉTODOS: Culturas de MSC obtidas de tecido adiposo de ratos jovens da linhagem Lewis transgênicos para proteína verde fluorescente (GFP foram submetidos a três diferentes meios de diferenciação cardiogênica: Planat-Bérnard, 5-azacitidina e meio Planat-Bérnard + 5-azacitidina e observadas quanto a expressão de marcadores celulares cardíacos. RESULTADOS: Nos três protolocos utilizados observou-se formação da proteína alfa-actinina sarcomérica no citoesqueleto das células submetidas à diferenciação, expressão de conexina 43 na membrana nuclear e citoplasmática e formação de gap junctions, necessárias para a propagação do impulso elétrico no miocárdio, contudo, em nenhum protocolo foi observada contração espontânea das células submetidas à diferenciação cardiogênica. CONCLUSÃO: A indução com 5-azacitidina proporcionou diferenciação celular cadiomiogênica efetiva e similar à encontrada com o meio Planat-Bénard e, por ser um protocolo mais simples, rápido e com menor custo torna-se o método de eleição.BACKGROUND: Cardiomyocytes have small potential for renovation and proliferation in vivo. Consequently, the heart muscle has limited capacity of self-renewal. Mesenchymal stem cells (MSC therapy, as well as MSC differentiated into cardiomyocytes, has been used in the attempt to minimize the effects of ischemic-hypoxic lesions and those affecting the electrical conduction system of the heart. OBJECTIVE: The present study compared three distinct protocols for induced differentiation of MSC into cardiomyocytes aimed at finding a viable method for producing a large number of functional cells expressing cardiomyogenic phenotype. METHODS: Mesenchymal stem cells were obtained from the adipose tissue of young transgenic Lewis rats expressing green fluorescent protein (GFP, and submitted to three distinct differentiation-inducing media: 1 Planat-Bérnard, 2 5-azacytidine, and 3 Planat-Bérnard + 5-azacytidine; further, these cells were identified based on the expression of cardiac cell markers. RESULTS: All three protocols detected the expression of sarcomeric-alpha-actinin protein in the exoskeleton of cells, expression of connexin-43 in the nuclear and cytoplasmic membrane, and formation of gap junctions, which are necessary for electrical impulse propagation in the myocardium. However, no spontaneous cell contraction was observed with any of the tested protocols. CONCLUSION: Induction with 5-azacytidine provided an effective cadiomyogenic cellular differentiation similar to that obtained with Planat-Bénard media. Therefore, 5-azacytidine was the method of choice for being the simplest, fastest and lowest-cost protocol for cell differentiation.

  5. HETEROSIS TO GRAIN PROTEIN CONTENT IN CROSSES AMONG MAIZE POPULATIONS DERIVED FROM COMMERCIAL HYBRIDS HETEROSE PARA TEOR DE PROTEÍNA NO GRÃO EM CRUZAMENTOS ENTRE POPULAÇÕES DE MILHO DERIVADAS DE HÍBRIDOS COMERCIAIS

    Directory of Open Access Journals (Sweden)

    Gladys Rodrigues Costa Pinto

    2008-03-01

    Full Text Available

    One of the greatest concerns on maize breeding throughout the years has been to increase production without reducing nutritional quality. The present study aims to evaluate F2 maize populations with normal endosperm and their crosses, as related to total grain protein content and determining heterosis and its components. The method used for protein content determination was proposed by AOAC ";Official methods of analysis";, adapted and used by CIMMYT (International Center for Maize and Wheat Breeding. The statistical diallelic analysis of data was carried out through the Gardner and Eberhart's model IV (1966. The fundamental operation for parameter estimation as well as for sums of squares calculation was the ordinary minimum squares. It was observed significance for all effects of the adopted model. For the trait total grain protein content, the best genitors were AG-6690 and ZN-8486, and the best hybrid combination was P30K75 x AG-6016.

    KEY-WORDS: Protein content; corn; normal endosperm; diallel crosses.

    Uma das maiores preocupações do melhoramento genético do milho, ao longo dos anos, foi aumentar sua produção, sem diminuir sua qualidade nutricional. Este trabalho objetivou avaliar populações F2 de milho com endosperma normal e seus cruzamentos, quanto ao teor de proteína total, determinando-se a heterose e seus componentes. A metodologia utilizada para as determinações da proteína total no grão foi aquela proposta pela AOAC "official methods of analysis", a qual foi adaptada e adotada pelo CIMMYT (Centro Internacional de Melhoramento de Milho e Trigo. A análise estatística dos dados foi realizada pelo modelo IV de Gardner & Eberhart (1966, para análise de cruzamentos dialélicos. A operação fundamental para estimação dos parâmetros, bem como para cálculo das somas de quadrados, foi a determinação de quadrados mínimos ordinários. Observou-se significância para todos os efeitos do modelo adotado. Destacaram-se, para o caráter teor de proteína total no grão, os genitores AG-6690 e ZN-8486, bem como a combinação híbrida P30K75 x AG-6016.

    PALAVRAS-CHAVE: Proteína total; milho; endosperma normal; cruzamento dialélico.

  6. Interpretação gráfica das derivadas de uma função por professores estagiários de Matemática

    Directory of Open Access Journals (Sweden)

    Conceição Almeida

    2002-01-01

    Full Text Available The Portuguese secondary school mathematics curriculum draws on results of research conducted in the Mathematics Education field to stress the importance of teaching mathematical concepts using, whenever possible, their different representations. Numerical, analytical and graphical approaches to the teaching of the derivative concept are indicated as essential to enhance conceptual meanings and relations. However, in general, students show a preference for analytical approaches in detriment of the graphical one, which may be the result of predominantly analytical teaching approaches. In this context, the goal of this study was to investigate mathematics student teachers difficulties in interpreting and relating the graphs of a function and those of their derivatives. A questionnaire about graphical representations of the derivative of a function was applied to 19 mathematics student teachers and an interpretative analysis of the results was performed.

  7. Mineralogía de series cretácicas de la zona subbética. Algunas consideraciones paleogeográficas derivadas de la composición química de las esmectitas

    Directory of Open Access Journals (Sweden)

    López Galindo, A.

    1986-10-01

    Full Text Available In this work the mineralogy of several smectite-rich Aptian-Conician Subbetic sequences is analyzed, with speciaI interest in the chemical composition of such components. The origin of main clay minerals is considered bearing in mind the similarity of our data and those found. in surrounding areas of submarine volcanic rocks. This fact and the presence of palygorskyte and clinoptilolite in a.ssocialion with smectites., leads us to think that, although some of me smectites heve a detritic origin, the greater pert are authigenic clays and/or halmyrolityc products of basaltic rocks.
    The relatively low content in iron and magnesium (between 0.6 and 0.9 by haIf unit-cell is interpreted as loss of such elements in the diagenetic evolution of smectites towards illitic terms.

    En este trabajo se estudia la mineralogía de diversas secuencias subbéticas muy ricas en esmectitas y de edad Aptense-Coniacense, haciendo especial hicapié en la composición química de tales componentes. Se discute el origen de los minerales de la arcilla más abundantes y, en base a comparaciones con los datos obtenidos en estudios similares realizados sobre esmectitas sedimentarias oceánicas, se llega a la conclusión que, si bien parte de éstas son de origen detrítico, la mayoría han podido formarse autígenamente y/o por alteración halmirolítica de rocas basálticas. Dicha hipótesis viene en parte avalada por la presencia de paligorskita y clinoptilolita, minerales frecuentemente descritos en este tipo de ambientes y originados durante los primeros estadios de la diagénesis.
    La relativa baja proporción de hierro y magnesio observado en las esmectitas (entre 0,6 y 0,9 átomos por media celdilla unidad se interpreta. como debida a una pérdida de tales elementos en la evolución diagenética de estos minerales hacia términos ilíticos.

  8. Extraction Factory for Palm-Tree Fat to Produce Biodiesel [O Crescente uso de Poliuretanas Derivadas do Óleo de Mamona no Mercado de Polímeros

    OpenAIRE

    Hugo F. Ramalho

    2013-01-01

    The traditional use of oil-based poliols is being systematically replaced by castor oil for the polyurethane production. This new application appears as an alternative to the failed use in the biodiesel industry, giving a second chance to the castor-bean oil production system. As a consequence, the objective of regional development proposed by the Brazilian government can still work resulting in financial profits since castor-bean oil is being used to make products with higher aggregate values.

  9. Bases moleculares y celulares del efecto antineoplásico del péptido CIGB-300 en células derivadas de tumores sólidos

    OpenAIRE

    Perera Negrin, Yasser

    2012-01-01

    El CIGB-300 es un péptido sintético seleccionado por su capacidad de inhibir la fosforilación catalizada por la enzima CK2 a través de la interacción con el sitio fosfoaceptor. Evidencias preliminares sugieren que el CIGB-300 es capaz de inhibir la proliferación celular y que retarda el crecimiento tumoral en un modelo singénico de cáncer. Sin embargo, la identidad del(los) blanco(s) molecular(es), y los efectos de la inhibición de su fosforilación sobre la célula tumoral no han sido caracter...

  10. Qualidade da bebida em espécies e populações derivadas de híbridos interespecíficos de Coffea Cupping quality of coffee species and interspecific hybrids

    Directory of Open Access Journals (Sweden)

    Alcides Carvalho

    1990-01-01

    Full Text Available Avaliou-se, em dois experimentos, a qualidade da bebida das espécies Coffea canephora e C. congensis e derivados de híbridações interespecíficas [C. canephora duplicado (dp x C. arabica, C. canephora x C. eugenioides, C. arabica x C. dewevrei dp e C. racemosa x C. arabica]. Por tratar-se de análise de bebida de cafés pouco conhecidos, avaliou-se a eficiência de uma escala de 1 a 10 pontos em comparação à escala de 0 a 5 pontos utilizada para C. arabica. Foram, também, acrescentadas pelos provadores indicações relacionadas ao gosto da bebida. A escala de 6 pontos mostrou-se pouco eficaz na discriminação dos tratamentos e a de 10 pontos, utilizada alternativamente, revelou-se mais eficiente nos dois experimentos. No primeiro, verificou-se, quanto à qualidade, uma superioridade dos grupos C arabica x C. dewevrei dp e C. canephora dp x C. arabica pelas duas escalas. No segundo experimento, o grupo C. racemosa x C. arabica apresentou a maior média, apesar de não diferir, pela escala 1, dos demais grupos. Pela escala 2, superou, no entanto, os grupos C. canephora e C. congensis. Gostos incomuns foram observados nas amostras com relação à bebida. Atribuem-se à grande diversidade do material analisado e a falta de familiarização dos provadores com espécies bem diferentes de C. arabica, certas discrepâncias com relação à determinação desses defeitos nas amostras analisadas.Investigations on coffee cupping quality of the species C. canephora, C. congensis and several populations derived from interespecific crosses (C. canephora dp x C. arabica, C. canephora x C. eugenioides, C. arabica x C. dewevrei dp and C. racemosa x C. arabica were undertaken in two trials, in order to guide breeding programs using this germoplasm. Two grading systems were used for classification of the cupping quality, the normal six points scale used for C. arabica samples and a new one with 10 points, 1 for the lowest and 10 for the highest quality. Coffee liquorer experts graded the overall cupping quality and added remarks to any unpleasant taste noticed in the samples. The analysis of the data pointed out that both scales were not adequate for a complete characterization and discrimination of the individual samples. When coffee samples ware grouped according to the species involved in the crosses, the results indicated the superiority of the C. arabica x C, dewevrei dp and C. canephora dp x C. arabica groups in the first trial. In the second trial the C. racemosa x C. arabica group revealed the best average cupping quality, statistically superior to C. canephora and C. congensis. Most of the non-commercial coffees displayed unique tastes and were characterized in 13 unpleasant types. Due to the inherent diversity of the analysed material the liquorer experts had difficulty in classifying the several abnormal tastes influencing the classification of the mild standard sample. The results indicated the necessity of more accurate studies of the beverage produced by these species mainly when they participate in the breeding of Arabica coffee.

  11. La responsabilidad civil derivada de la investigación clínica en los servicios asistenciales de la Caja Costarricense del Seguro Social (C.C.S.S.

    Directory of Open Access Journals (Sweden)

    José Fabio Oconitrillo Tenorio

    2002-09-01

    Full Text Available En Costa Rica se llevan a cabo investigaciones clínicas en los servicios asistenciales de la Caja Costarricense del Seguro Social, sin cumplirse con los requisitos establecidos en nuestro ordenamiento jurídico. Así, debe revisarse la regulación existente sobre el factor indemnizatorio que los participantes de la investigación clínica -patrocinador, investigador, institución pública o privada- deben cumplir y observar como elemento configurante del consentimiento informado, de forma tal que no se lleve a cabo la investigación si no se cuenta con una póliza obligatoria por parte de los promoventes, que cubra las diversas eventualidades de lesión y muerte del sujeto a experimentación.In Costa Rica, several clinic investigations have taken place in the medical services of the Social Security without filling the requirements that our legal system establishes. lt is necessary that the regulation of the indemnizatory factor that the people involved in the investigation, like the host, investigator, public or private institutions, have to fulfill and regard, as a configuring element, the acknowledged. information, in a way that the investigation cannot be made if they do not give the respective accountability to pay for eventual mistakes, lesions and ever death of the subject of the investigation.

  12. Aplicaciones legales derivadas de la incorporación del software libre en la función pública de los registros y notarías

    Directory of Open Access Journals (Sweden)

    Mercedes Villalobos

    2011-05-01

    Full Text Available Desde la entrada en vigencia de la Constitución del año 2000, se persigue el alcance de la autonomía e independencia tecnológica para contribuir al desarrollo económico, social y político del país. Así, se ordenó el uso obligatorio del software libre en la Administración Pública con el fin de promover la prestación oportuna y eficiente de los servicios públicos a medida que la tecnología se vaya incluyendo como un instrumento de dicha labor. Ejemplo de ello es el Ministerio del Poder Popular para Relaciones Interiores y Justicia, que a través del Servicio Autónomo de Registros y Notarías y, la emisión de los decretos y leyes que rigen la correspondiente competencia como el caso del Decreto Presidencial N 3.390 (Presidencia de la República, 2004, se ha implementado la modernización a través de la automatización de los procesos registrales y notariales con el empleo de los medios electrónicos, en donde tiene cabida el software libre. Al respecto ha surgido el interés de trabajar con el objeto de establecer la efectiva aplicación legal de la función pública desarrollada por los Registros y Notarías con la implementación de tal migración informática. Para ello se adoptó una investigación de tipo documental con diseño bibliográfico y el método de observación documental a partir de la Ley del Registro Público y del Notariado (Asamblea Nacional, 2006 y la Ley Orgánica de Registro Civil (Asamblea Nacional, 2009, que regulan la materia registral y notarial en Venezuela, permitiendo obtener resultados a través de una hermenéutica jurídica aplicable en el método de análisis dogmático jurídico; concluyéndose en el conocimiento de los efectos legales que determinaron la esencialidad de las acciones concretas para usar este tipo de software, acordes con los preceptos aplicables a la función pública especificada.

  13. Mechanical and thermal properties of castor oil polyurethane bone cement after gamma irradiation;Propriedades mecanicas e termicas de poliuretanas derivadas do oleo de mamona usadas como cimento osseo depois da irradiacao com radiacao gamma

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, E.C. [Universidade Tecnologica Federal do Parana (DF/UTFPR), Curitiba, PR (Brazil). Dept. de Fisica; Soboll, D.S. [Universidade Tecnologica Federal Parana (CPGEI/UTFPR), Curitiba, PR (Brazil); Chierice, G.O.; Claro Neto, S. [Universidade de Sao Paulo (IQSC/USP), Sao Carlos, SP (Brazil). Inst. de Quimica; Lepiesnki, C.M. [Universidade Federal do Parana (DF/UFPR), Curitiba, PR (Brazil). Dept. de Fisica; Nascimento, E.M. [Universidade Tecnologica Federal do Parana (DM/UTFPR), Curitiba (Brazil). Dept. de Mecanica

    2009-07-01

    Polyurethanes from castor oil are being employed as bone cement in medical applications. In this work the thermal and mechanical properties of gamma irradiated polyurethanes derivative from castor oil were investigated by instrumented indentation, thermogravimetry and scanning electron microscopy. A slightly increase in hardness is observed only for doses as high as 100 kGy. Thermal analysis indicates stability at human body temperature. The glass transition temperature has small changes after gamma irradiation. (author)

  14. Aluminum and steel adhesion with polyurethanes from castor oil adhesives submitted to gamma irradiation;Estudo da adesividade do aco e aluminio com adesivo de poliuretana derivada de oleo de mamona submetido a radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Elaine C.; Assumpcao, Roberto L.; Nascimento, Eduardo M. do, E-mail: elainazeve@utfpr.edu.b [Universidade Tecnologia Federal do Parana (UTFPR), Curitiba, PR (Brazil); Claro Neto, Salvador [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil); Soboll, Daniel S. [Universidade Tecnologia Federal do Parana (CPGEI/UTFPR), Curitiba, PR (Brazil). Programa de Pos-Graduacao em Engenharia Eletrica e Informatica Industrial; Lepienski, Carlos M., E-mail: elainazeve@utfpr.edu.b [Universidade Tecnologia Federal do Parana (UTFPR), Curitiba, PR (Brazil)

    2009-07-01

    Polyurethanes adhesive from castor oil is used to join aluminum and steel pieces. The effect of gamma radiation on the resistance to tension tests is investigated. The aluminum and steel pieces after being glued with the adhesive were submitted to gamma irradiation in doses of 1 kGy, 25 kGy and 100 kGy. The rupture strength of the joints after irradiation have a slightly increase or remains practically unchanged indicating that the adhesive properties is not affected by the gamma radiation. (author)

  15. Alterações Geomorfológicas Derivadas Da Intervenção De Atividades Antrópicas: análise temporal na Bacia do Arroio Santa Bárbara – Pelotas (RS.

    Directory of Open Access Journals (Sweden)

    Adriano Luís Heck Simon

    2010-08-01

    Full Text Available A análise temporal das alterações nas formas do relevo, tendo como base informações espaciais oriundas da cartografia geomorfológica, possibilita a compreensão da gênese dos distúrbios na morfodinâmica e dos impactos ambientais. Assim, este artigo foi desenvolvido com o objetivo de analisar as principais alterações geomorfológicas desencadeadas na bacia do Arroio Santa Bárbara, localizada no município de Pelotas – RS, durante 41 anos (1965 – 2006. Para avaliar as alterações ocorridas sobre a morfologia, foram elaborados mapas geomorfológicos da área em estudo, referentes aos anos de 1965 e 1995, a partir da interpretação de fotografias aéreas. O cenário de 2006 foi constituído por meio de representações cartográficas, esquematizadas a partir da obtenção de imagens orbitais do software Google Earth TM. A integralização deste mapeamento ocorreu por meio de trabalhos de campo, onde foram constatadas as transformações da morfologia e as feições geomorfológicas artificiais. As atividades antrópicas efetivaram a imposição de mecanismos de controle que alteraram as formas e a estrutura do sistema, agindo, conseqüentemente, sobre os fluxos de matéria e energia. Tais alterações vinculam-se à expansão urbana, ao desenvolvimento das atividades agrícolas e às ações antrópicas pontuais como a mineração e a interceptação dos cursos de água para a construção de reservatórios.

  16. Simplified process of manufacture of solar cells with 17% efficiencies using Cz substrata of low resistivity; Monitoramento do processo de fabricacao de celulas solares de silicio de alto rendimento, com passivacao posterior e utilizando silicio Cz de Baixa Resistividade

    Energy Technology Data Exchange (ETDEWEB)

    Stem, N.; Cid, M.; Ramos, C. A.S.; Chenlo, F.

    2008-07-01

    This work describes the fabrication process of solar cells with rear passivated surface using low resistivity Cz silicon of two different manufacturers. the PCD technique allowed to quantify the lifetime, about 0,25 ms (p=2.5{omega}.cm) and 0.35 ms (p=3.3.{omega}.cm) measured at the end of the process, and the implied open-circuit voltages of 652.5mV and 662.6mV, respectively. Efficiencies higher than 20% were predicted for an optical frontal system composed by random texturization with ZnS-MgF{sub 2}. (Author)

  17. Evaluation of the recombination in somatic cells induced by radiation in different stages of Drosophila larval development; Evaluacion de la recombinacion en celulas somaticas inducida por radiacion en diferentes etapas del desarrollo larvario de Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Cruces, M.P.; Morales R, P. [Instituto nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The mitotic recombination can happen spontaneously and its frequency is very low, however the recombination rate of a cell can be increased by the exposure to agents which cause damage to DNA. This type of agents are knew commonly as recombinogens. The ionizing radiation and a numerous chemical agents can be mentioned (Vogel, 1992). The objective of this work is to determine if the mutation/recombination rate induced by gamma rays varies with the development stage. In order to realize this investigation it was used the mutation and somatic recombination test of Drosophila wing (Graf and col. 1984). The mwh/ mwh and flr{sup 3}/TM3, Ser stocks were used. (Author)

  18. P{sub N} solutions for the slowing-down and the cell calculation problems in plane geometry; Solucoes P{sub N} para os problemas da moderacao e do calculo de celula em geometria plana

    Energy Technology Data Exchange (ETDEWEB)

    Caldeira, Alexandre David

    1999-07-01

    In this work P{sub N} solutions for the slowing-down and cell problems in slab geometry are developed. To highlight the main contributions of this development, one can mention: the new particular solution developed for the P{sub N} method applied to the slowing-down problem in the multigroup model, originating a new class of polynomials denominated Chandrasekhar generalized polynomials; the treatment of a specific situation, known as a degeneracy, arising from a particularity in the group constants and the first application of the P{sub N} method, for arbitrary N, in criticality calculations at the cell level reported in literature. (author)

  19. Preparation of gas diffusion layers for PEMFC fuel cells using carbon fibers; Elaboracao de uma camada de difusao de gas a partir de fibras de carbono para aplicacao em celulas combustiveis do tipo PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Santos, J.N.; Kunsti, S.R.; Malfatti, C.F. [Universidade Federal do Rio Grande do Sul - Departamento de Metalurgia (PPGEM) - Laboratorio de Pesquisa em Corrosao (LAPEC), Porto Alegre, RS (Brazil); Vargas, J.V.C. [Universidade Federal do Parana - Departamento de Engenharia Mecanica, PR (Brazil); Amico, S.C. [Universidade Federal do Rio Grande do Sul - Departamento de Materiais, RS (Brazil)

    2010-07-01

    The electrode/membrane system, called MEA, is the fundamental unit of a PEMFC (proton exchange membrane fuel cell). Within the MEA, the gas diffusion layer (GDL) is the bridge between the flow field and the catalyst layer. One of the important elements in a GDL is the substrate, typically a carbon cloth or paper, that has to be an excellent electrical conductor and show mechanical strength along with thermal and chemical stability. In this work, GDLs were produced from a suspension containing short carbon fibers in water-based polyurethane and poly(vinyl alcohol) (PVA) resins with appropriate characteristics to be used in low temperature fuel cells. The obtained GDL was characterized regarding its wettability, electrical conductivity and morphological aspects, evaluated by SEM. (author)

  20. Energetic-economical analysis of a stationary for energy generation with fuel cells and natural gas reforming; Analise energetico-economica de um sistema estacionario de geracao de energia com celulas a combustivel e reforma de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Jose Geraldo de Melo; Silva Junior, Fernando Rodrigues; Silva, Cristiane Abrantes da; Soares, Guilherme Fleury Wanderley; Lopes, Francisco da Costa; Serra, Eduardo Torres [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)]. E-mail: furtado@cepel.br; Codeceira Neto, Alcides [Companhia HidroEletrica do Sao Francisco (CHESF), Recife, PE (Brazil)

    2008-07-01

    Power systems based on fuel cells have been considered for residential and commercial applications in energy Distributed Generation (DG) market as these systems can minimize their acquisition, installation and operation high costs. In this work we present an experimental analysis of a power generation system formed by a 5 kW proton exchange membrane fuel cell unit and a natural gas reformer (fuel processor) for hydrogen production, of the CEPEL's Fuel Cell Laboratory. It was determined the electrical performance of the cogeneration system in function of the design and operational power plant parameters. Additionally, it was verified the influence of the activation conditions of the fuel cell electrocatalytic system on the system performance. It also appeared that the use of hydrogen produced from the natural gas catalytic reforming provided the system operation in excellent electrothermal stability conditions resulting in increase of the energy conversion efficiency and of the economicity of the cogeneration power plant. The maximum electrical efficiency achieved was around 38% and in all power range unit operated with average potential per single fuel cell higher than 0.60 V. (author)

  1. Study of a fuel cell insertion in a hybrid system for energy generation; Estudo da insercao de celula a combustivel integrada a sistema hibrido de geracao de eletricidade isolado

    Energy Technology Data Exchange (ETDEWEB)

    Vale, Silvio Bispo do; Bezerra, Ubiratan Holanda; Pinho, Joao Tavares; Pereira, Edinaldo Jose da Silva [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Programa de Pos-Graduacao em Engenharia Eletrica. Grupo de Estudo e Desenvolvimento em Alternativas Energeticas

    2004-07-01

    This paper presents a case study of a fuel cell (FC) insertion in a small hybrid system for energy generation composed by wind (10 kW), photovoltaic (3,2 kW) and diesel (20 kVA) generations, making computer simulations in order to evaluate the contribution of each one of the energy-supply systems involved. This paper intends to contribute for the establishment of parameters to measure the technical and economic viability for using such isolated hybrid systems, trying in the future several combinations of models to hybridize the energy generation in Amazon isolated villages, making easier the use of local energy resources. (author)

  2. Union of {sup 99m} Tc-HYNIC-TOC at the somatostatin receptors in cells of pancreas cancer; Union del {sup 99m} Tc-HYNIC-TOC a los receptores de somatostatina en celulas de cancer de pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez C, J. [Facultad de Medicina, UAEM, 50000 Toluca, Estado de Mexico (Mexico); Ramirez I, M.T. [INCMNSZ, Vasco de Quiroga Num. 15, Tlalpan, 14000 Mexico D.F. (Mexico); Ferro F, G.; Pedraza L, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2005-07-01

    The radiation toxic effects have been used in therapy however much 50 years. The absorbed radiation dose can be determined at cellular level using cancerous cell cultures. If the deposited In vitro radiation dose coming from similar activities of several therapeutic radiopharmaceuticals it can compare it will be possible to choose the therapeutic radiopharmaceutical that it offers better dosimetric characteristics for the patient. The objective of this original investigation was to determine the union percentage of the octreotide {sup 99m}Tc-HYNlC-TOC to the somatostatin receivers in cells of cancer pancreas as well as the internalization, externalization and cellular viability. It was used the octapeptide, (octreotide, TOC) labelled with {sup 99m}Tc by means of the HYNIC chelating agent (6-hydrazine pyridine-3-carboxylic acid) and 3 cellular lines of murine pancreas cancer (AR42J), of cancer of human pancreas (CAPAN) and of one negative cellular line for somatostatin receivers (WRL-68). The {sup 99m}Tc-HYNIC-TOC was compared against two negative proofs for somatostatin receivers: the peptide {sup 99m}Tc-UBI and the {sup 99m}TcO{sub 4}. The cellular lines were conserved in the synthetic media Dulbecco-Eagle. After 2, 4 and 24 h of exhibition to the radiation, the cells are picked up and its are determined the viability by count in a Neubauer camera using tripan blue. In the same times it was calculated the union percentage of the radiopharmaceutical to the cells and the internalization (union to the cytoplasm) and the externalization (union to membrane receivers). With those figures it was calculated the absorbed radiation dose at cellular level. Results: At 4 hours the union percentage of the {sup 99m}Tc-HYNlC-TOC to the AR42-J cells was 6.83 times greater than for the WRL-68 control cells of human papilloma, (without receivers of the somatostatin) and for the CAPAN them 4 times greater than for the same cells used as negative control, for the case of the {sup 99m}Tc-UBI and the {sup 99m}TcO{sub 4} one doesn't observe a significant difference and the percentage of viability of the AR42-J cells due by the {sup 99m}Tc-HYNlC-TOC it was 20% smaller in comparison with {sup 99m}Tc-UBI and {sup 99m}TcO{sub 4}. The internalization percentage of the AR42-J cells was of 43.28 {+-}1.62 due to the somatostatin receivers that its enter together with the radiopharmaceutical at the interior of the cell and 56.72 {+-}3.25 are together to the cellular membrane. (Author)

  3. Hydrogen production through allothermal ethanol reforming for fuel cells application: first generation prototype; Producao de hidrogenio atraves da reforma-vapor do etanol para aplicacoes em celulas a combustivel: prototipo de primeira geracao

    Energy Technology Data Exchange (ETDEWEB)

    Marin Neto, Antonio Jose; Silva, Ennio Peres da; Camargo, Joao Carlos; Neves Junior, Newton Pimenta; Pinto, Cristiano da Silva [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Lab. de Hidrogenio; Pinto, Cristiano da Silva [Centro Nacional de Referencia em Energia do Hidrogenio, Campinas, SP (Brazil)

    2004-07-01

    This paper describes preliminary results obtained with the allothermal ethanol reforming system for synthesis gas (syn-gas) production and hydrogen upgrading and purification for fuel cell applications. The system was designed to supply hydrogen to a 500 W PEM (Proton Exchange Membrane) fuel cell, with an electrical efficiency of 45%, which requires approximately 0.45 m3.h-1 of hydrogen, with a maximum carbon monoxide concentration of 20 {mu}mol.mol-1 (ppm). The study was performed changing the operation temperature and analyzing the resulting syn-gas through gas chromatography for a specific catalyst. This catalyst was tested up to 700 deg C, 1 bar and fixed stoichiometric steam to carbon ratio. The syn-gas, before carbon monoxide shift reactor implementation, was submitted to a two-bed-three-segments purification step composed of chemical and physical molecular sieves for hydrogen purification. The carbon monoxide shift reactor (water gas shift reactor) is under development to improve the efficiency-to-hydrogen and maximize the life of the purification bed. The final results also include a discussion about possible reactions involved in ethanol steam-reforming for such catalyst. (author)

  4. Importance of gallium-67 scintigraphy in primary cutaneous B-cell lymphoma: report of two cases;Importancia da cintilografia com galio-67 no linfoma cutaneo primario de celulas B: relato de dois casos

    Energy Technology Data Exchange (ETDEWEB)

    Attab, Cyomara Sanches, E-mail: rubinha.attab@terra.com.b [Centro Brasileiro de Medicina Nuclear (CEBRAMEN), Goiania, GO (Brazil); Moriguchi, Sonia Marta [Fundacao Pio XII, Barretos, SP (Brazil). Hospital de Cancer; Paton, Eduardo Jose Alencar [Fundacao Pio XII, Barretos, SP (Brazil). Cancer Hospital. Div. of Hemotherapy and Bone-Marrow Transplant; Alencar, Mario Henrique Leite de [Clinica de Prevencao em Cancer, Goiania, GO, (Brazil); Rocha, Euclides Timoteo da [Fundacao Pio XII, Barretos, SP (Brazil). Cancer Hospital. Dept. of Nuclear Medicine

    2010-05-15

    The authors describe two cases of cutaneous B-cell lymphoma where correct staging, treatment and follow-up could be achieved through a combination of conventional imaging studies and gallium-67 scintigraphy. (author)

  5. Synthesis and ceramic processing of zirconia alumina composites for application as solid oxide fuel cell electrolytes; Sintese e processamento de compositos de zirconia-alumina para aplicacao como eletrolito em celulas a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Rafael Henrique Lazzari

    2007-07-01

    The global warmness and the necessity to obtain clean energy from alternative methods than petroleum raises the importance of developing cleaner and more efficient systems of energy generation, among then, the solid oxide fuel cell (SOFC). Cubic stabilized zirconia (CSZ) has been the most studied material as electrolyte in SOFC, due to its ionic conductivity and great stability at operation conditions. However, its low fracture toughness difficulties its application as a thin layer, what could lead to an improvement of cell efficiency. In this sense, the alumina addition in CSZ forms a composite, which can shift its mechanical properties, without compromising its electrical properties. In this work, coprecipitation synthesis route and ceramic processing of zirconia-alumina composites were studied, in order to establish optimum conditions to attain high density, homogeneous microstructure, and better mechanical properties than CSZ, without compromising ionic conductivity. For this purpose, composites containing up to 40 wt % of alumina, in a 9 mol % yttria-stabilized zirconia (9Y-CSZ) matrix were evaluated. In order to optimize the synthesis of the composites, a preliminary study of powder obtaining and processing were carried out, at compositions containing 20 wt % of alumina, in 9Y-CSZ. The ceramic powders were characterized by helium picnometry, X-ray diffraction, scanning electronic microscopy, transmission electronic microscopy, thermogravimetry, differential scanning calorimetry, granulometry by laser diffraction and gas adsorption (BET). The characterization of sinterized compacts were performed by X-ray diffraction, scanning electron microscopy, optical microscopy, density measurements, Vickers indentation and impedance spectroscopy. The obtained results show that the alumina addition, in the 9Y-CSZ matrix powders, raises the specific surface area, promotes deagglomeration of powders and elevates the oxides crystallization temperature, requiring higher energetic thermal treatments to attain high densities. In relation to the sintered products, it was confirmed the excellent homogeneity and crystallinity of microstructure provided by the chosen route, the restriction of grain growth by alumina addition, raise of hardness and fracture toughness, and higher ionic conductivity, even tough a lower bulk conductivity. These results indicate that the addition of 5 wt % alumina in CSZ matrix allows the application of this material as solid oxide fuel cell electrolytes, due to its better fracture toughness and ionic conductivity, compared to yttria-stabilized cubic zirconia ceramics. (author)

  6. Synthesis of yttria-doped zirconia anodes and calcium-doped ceria electrolyte to fuel cell; Sintese de anodos de zirconia dopada com itria e eletrolito de ceria dopada com calcia para celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, G.R.S de; Fagury Neto, E.; Rabelo, A.A., E-mail: grs_gustavo@hotmail.co [Universidade Federal do Para (UFPA), Maraba, PA (Brazil). Fac. de Engenharia de Materiais

    2010-07-01

    From the pursuit of lower operating temperature of fuel cells solid oxide was used polymeric precursor for the synthesis of reactive powder compositions Zr{sub 0,92}Y{sub 0,08}O{sub 2} for the anode and Ce{sub 0,88}Ca{sub 0,12}O{sub 2} for the electrolyte. The solutions were prepared using the metal in much of the composition and citric acid molar ratio of 1:3, under stirring at 60 deg C/1 h. The mixture of metallic citrates was subjected to agitation at a temperature of 80 deg C which was added ethylene glycol in the ratio 60:40 by weight citric acid / ethylene glycol, to form a resin that was pre-calcined at 300 deg C/3 h for to form the expanded resin. The powders were disaggregated in a mortar, screened and calcined at 400, 600 and 800 deg C/2 h. The powders were characterized by standard X-ray diffraction. (author)

  7. Influence of photon recycling effects in the operation and design of GaAs solar cells; Influencia del reciclaje de fotones en el funcionamiento y del diseno de las celulas solares de Arsenico de Galio

    Energy Technology Data Exchange (ETDEWEB)

    Balenzategui Manzanares, J. L.

    2005-07-01

    Photon recycling (PR) is the process by which photons internally emitted in a semiconductor can be re-absorbed by the material, giving as result new electron-hole pairs. Although this process has been receiving some international research from the Sixties, because their effects revealed as relevant in certain devices and materials (as in gallium arsenide), its influence in the operation of solar cells has been scarcely considered in the past. Thus deposited it has been demonstrated that one of its major effects is an enhancement of the radiative carrier lifetine, photon recycling is not usually taken into account in photovoltaic, neither in device modelling and simulation, nor from the perspective of taking advantage of the phenomenon to improve the efficiency of solar cells. This work describes the results of our investigations in the field of photon recycling. (Author)

  8. Stable expression of human thyrotropin (hTSH) in mammalian cells (CHO) expressing {alpha}2,6 sialyltransferase; Expressao estavel tireotrofina humana (r-hTSH) em celulas de mamifero (CHO) que expressam {alpha}2,6 sialiltransferase

    Energy Technology Data Exchange (ETDEWEB)

    Damiani, Renata

    2009-07-01

    A CHO cell line, previously genetically modified by the introduction of rat {alpha}2,6-sialyltransferase cDNA, generated for the first time a human-like sialylated recombinant hTSH (hlsr-hTSH) more similar to the native hormone, with 61% of {alpha}2,3- and 39% of {alpha}2,6-linked sialic acid residues. The best clone, when submitted to gene amplification with up to 8 {mu}M methotrexate, presented a secretion level of {approx}2 {mu}g hTSH/10{sup 6} cells/day, useful for product purification and characterization. The relative molecular masses (M{sub r}) of the heterodimer and of the {alpha}- and {beta}-subunits of purified hlsr-hTSH, determined by MALDI-TOF mass spectrometry, and the relative hydrophobicities, determined by RP-HPLC, were not remarkably different from those presented by two r-hTSH preparations secreted by normal CHO cells. Some differences were observed, though, in N-glycan composition, with more tri- and much more tetra-sialylated structures in hlsr-hTSH. When analyzed via an in vivo bioassay based on hTSH-induced T{sub 4} release in mice, hlsr-hTSH was shown to be equipotent (p > 0.05) with the commercial preparation of r-hTSH (Thyrogen), and 1.5-fold more potent than native hTSH (p < 0.001). (author)

  9. Thermodynamical simulation for solid oxide (SOFC) type fuel cells with ethanol direct internal reforming; Simulacao termodinamica para celulas a combustivel do tipo SOFC com reforma interna direta do etanol

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Aline Lima da; Malfatti, Celia de Fraga; Heck, Nestor Cezar [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia de Minas, Metalurgica e de Materiais (PPGEM)]. E-mail: als14br2000@yahoo.com.br; Mello, Celso Gustavo [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Quimica (PPGEQ); Halmenschlager, Cibele Melo [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia de Minas, Metalurgica e de Materiais (PPGEM). Lab. de Materiais Ceramicos

    2008-07-01

    In SOFC, high operative temperature allows the direct conversion of ethanol into H{sub 2} to take place in the electrochemical cell. Direct internal reforming of ethanol, however, can produce undesirable products that diminish system efficiency and, in the case of carbon deposition over the anode, may occur the breakdown of the electrode. In this way, thermodynamic analysis is fundamental to predict the product distribution as well as the conditions favorable for carbon to precipitate inside the cell. Equilibrium determinations are performed by the Gibbs energy minimization method, using the GRG algorithm. Thermodynamic conditions for carbon deposition were analyzed, in order to establish temperature ranges and H{sub 2}O/ethanol ratios where carbon precipitation is not feasible. A mathematical relationship between Lagrange multipliers and carbon activity is presented, unveiling the carbon activity in atmosphere. The effect of the type of solid electrolyte (O{sup 2-} or H{sup +} conducting) on carbon formation is also investigated. The results of this work are in agreement with previous results reported in literature using the stoichiometric method. (author)

  10. The proliferation induced by hyperthermia in NB69 cells is offset by a radar-like signal; La proliferacion inducida por hipertermia en celulas NB69 es contrarrestada por una senal de tipo radar

    Energy Technology Data Exchange (ETDEWEB)

    Trillo Ruiz, M. A.; Martinez Pascual, M. A.; Cid Torres, M. A.; Pague de la Vega, J. E.; Chacon Vargas, L.; Ubeda Maeso, A.

    2011-07-01

    The present study describes the proliferative response of the cell line NB69 human neuroblastoma, the simultaneous exposure to two physical agents: mild hyperthermia (+1 degree centigrade) and a pulsed signal RFsubthermal.

  11. Action of the chlorophyllin on the genetic damage induced by gamma radiation in germinal cells of Drosophila Melanogaster; Accion de la clorofilina sobre el dano genetico inducido por radiacion gamma en celulas germinales de Drosophila Melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Cruces, M.P.; Pimentel, A.E.; Moreno, A.; Moreno, R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2003-07-01

    The obtained results using somatic cells, they have evidenced that the chlorophyllin (CHLN) it can act inhibiting or increasing the damage caused by different mutagens. The objective of this investigation is to evaluate the effect of the CHLN on the damage induced by gamma radiation in germinal cells of Drosophila. Two tests were used, the lost of the X chromosome and the conventional test of lethal recessive bound to the sex (LRLS); both with a system of litters. The obtained results in both essays, indicated that the CHLN doesn't reduce the damage induced by the gamma radiation in none of the cellular monitored states. (Author)

  12. Removal of ammonia generated from farm poultry and their use in the fuel cells and as fertilizer; Remocao de amonia gerada em granjas avicolas e sua utilizacao em celulas a combustivel e uso como fertilizante

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Joao Coutinho

    2010-07-01

    The process here stressed uses a cation exchange material. The aim of the present work has been to prepare a suitable cation exchanger material with especially high selectivity for ammonia, as the cation NH{sub 4+} or as aqueous ammonia solution containing NH{sub 4}OH hydroxide as well. Aliquots of the above mentioned exchangers were set up inside an chicken farm production near Sao Paulo city. Periodically the exchanger was removed to the laboratory and eluted with a convenient acid to regenerate the exchanger for the new cycle. The ammonia retention was quite high and presents no difficulty for its elution. The selected exchanger is a solid material, non toxic, without smell and have good physical properties. The first results encouraged us and our plants to do large experiments that in progress. This process is a contribution to remediation of the avicola local, removing the ammonia gas and suppressing greatly its smell and bad effect to the animals and even to workers. (author)

  13. Synthesis and characterization of Pt-Sn-Ni alloys to application as catalysts for direct ethanol fuel cells; Sintese e caracterizacao de ligas de Pt-Sn-Ni para aplicacao como caztalisadores em celulas a combustivel do tipo DEFC

    Energy Technology Data Exchange (ETDEWEB)

    Silva, E.L. da; Correa, P.S.; Oliveira, E.L. de; Takimi, A.S.; Malfatti, C.F., E-mail: celia.malfatti@ufrgs.b [Universidade Federal do Rio Grande do Sul (LAPEC/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica. Lab. de Pesquisa em Corrosao; Radtke, C. [Universidade Federal do Rio Grande do Sul (IQ/UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica

    2010-07-01

    Direct ethanol fuel cells (DEFCs) have been the focus of recent research due its application in mobile energy sources. In order to obtain the maximum efficiency from these systems, it is necessary the total ethanol oxidation, which implies in C-C bond break. Different catalysts described in literature are employed with this intent. This work consists in studying PtSnNi catalysts supported on carbon Vulcan XC72R, to application in DEFCs. Thus, it was used the impregnation/reduction method, varying the atomic proportion among Pt, Sn and Ni. The alloys were characterized by X-Ray Diffraction, Cyclic Voltammetry and Transmission Microscopy. Preliminary results show that predominant structure on the catalysts is the face centered cubic platinum and the densities currents are dependent on the platinum amount. (author)

  14. Vitrification of nanotoxic waste (Ru) from the production of nano-catalysts for direct ethanol fuel cells; Vitrificacao de nano-residuos toxicos (Ru) provenientes da producao de nano-catalisadores para celulas a combustivel de etanol direto

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.C.; Julio-Junior, O.; Mello-Castanho, S.R.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    Nanostructured catalysts have been developed for ethanol directly use in fuel cells, which due to the economic advantages that should have widespread use in the near future. The catalysts for these devices using nano-structured metal are based, where the toxic nature and environmental risks presented by these metals are largely enhanced by nano-dispersion. Thus, the production of nano-catalysts are potentially generating highly hazardous waste for public health and the environment. This study presents the treatment and inertization of ruthenium (Ru) nanoparticles waste containing by the vitrification technique and consequent attainment of silicate glasses for potential commercial use. Compositions were prepared containing up to about 20 wt % of nano-waste by changing the basic composition of glass soda-lime-borosilicate. After the fusion, at a temperature of 1100 deg C, the glasses were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Infra-red in the Fourier transform (FT-IR) techniques. The chemical stability was evaluated by hydrolytic attack test. The glass containing 20 wt % of nano-residue showed a high chemical stability, similar to a usual soda-lime glass. (author)

  15. Development of a computational model applied to a unitary 144 cm{sup 2} proton exchange membrane fuel cell; Desenvolvimento de um modelo numerico computacional aplicado a uma celula a combustivel unitaria de 144 CM{sup 2} tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Robalinho, Eric

    2009-07-01

    This work presents the development of a numerical computer model and methodology to study and design polymeric exchange membrane fuel cell - PEM. For the validation of experimental results, a sequence of routines, appropriate to fit the data obtained in the laboratory, was described. At the computational implementation it was created a new strategy of coupling two 3-dimensional models to satisfy the requirements of the comprehensive model of the fuel cell, including its various geometries and materials, as well as the various physical and chemical processes simulated. To effective assessment of the real cell analogy with numerical model, numerical studies were carried out. Comparisons with values obtained in the literature, characterization of variables through laboratory experiments and estimates from models already tested in the literature were also performed. Regarding the experimental part, a prototype of a fuel cell unit of 144 cm of geometric area was designed, produced and operated at laboratory with the purpose of validating the numerical computer model proposed, with positive results. The results of simulations for the 2D and 3D geometries proposed are presented in the form of polarization curves, highlighting the catalytic layer model based on the geometry of agglomerates. Parametric and sensitivity studies are presented to illustrate the change in performance of the fuel cell studied. The final model is robust and useful as a tool for design and optimization of PEM type fuel cells in a wide range of operating conditions. (author)

  16. Synthesis and characterization of sulfonic acid membranes based on interpenetrating polymer networks for application in fuel cells; Sintese e caracterizacao de membranas sulfonadas baseadas em redes polimericas interpenetrantes para aplicacao em celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, Lyzed Toloza; Loureiro, Felipe A.M.; Rocco, Ana Maria [Grupo de Materiais Condutores e Energia, Escola de Quimica, Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)], e-mail: amrocco@eq.ufrj.br; Pereira, Robson Pacheco [Instituto de Ciencias Exatas, Universidade Federal Fluminense (UFF), Volta Redonda, RJ (Brazil)

    2011-07-01

    In the present work, the synthesis and characterization of sulfonic membranes based on interpenetrating polymer networks (IPN). In order to obtain such systems, the diglycidyl ether of bisphenol A (DGEBA) was polymerized in presence of polyethyleneimine (PEI). These membranes were submitted to sulfonation reactions, originating IPN-SO{sub 3}H membranes. The characterization by FTIR evidenced the formation of a Semi-IPN structure, while sulfonation reactions resulted in systems containing -SO{sub 3}H groups covalently bonded to the chains. The membranes exhibited water retention up to 200 degree C, in a temperature range sufficient for application in PEMFC under hydration. (author)

  17. Acid membranes of poly(vinyl alcohol) for direct ethanol fuel cell applications; Membranes acidas de poli(alcool vinilico) para aplicacoes em celulas a combustivel via etanol direto

    Energy Technology Data Exchange (ETDEWEB)

    Dutra Filho, Jose C.; Gomes, Ailton S. [Instituto de Macromoleculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, RJ (Brazil)], e-mail: asgomes@ima.ufrj.br

    2011-07-01

    Proton-conducting hybrid membranes composed of poly(vinyl alcohol) (PVA), phosphotungstic acid (HPW) and diethylenetriaminepentaacetic acid (DTPA) where prepared. The effect of HPW doping and crosslink with DTPA on the membranes properties such as uptake, pervaporation and proton conductivity was investigated. Uptake and permeated flux decreases with increasing content of HPW and DTPA. Ethanol permeabilities obtained was about two orders of magnitude smaller than Nafion 117. FTIR spectra indicated that HPW was incorporated into the polymer matrix and DTPA acted as crosslink agent. The proton conductivity was in the order of 10-3 S.cm-1 with added 4 wt.% of DTPA and generally increases with the addition of HPW. (author)

  18. In vitro study of the effects of radio frequency generated for plasma in neoplastic cells HT-29; Estudo in vitro dos efeitos da radiofrequencia gerada por plasmas em celulas neoplasicas HT-29

    Energy Technology Data Exchange (ETDEWEB)

    Andrighetto, Daniela; Dornelles, Eduardo Bortoluzzi; Cruz, Ivana Beatrice Manica da; Lüdke, Everton, E-mail: daniela.andrighetto@hotmail.com, E-mail: dornellesedu@gmail.com, E-mail: ibmcruz@hotmail.com, E-mail: evertonludke@gmail.com [Universidade Federal de Santa Maria (UFSM), RS (BRazil)

    2014-07-01

    The goal of this study is to develop an in vitro irradiation cell system with controllable irradiation intensities of 27 MHz produced by an argon plasma column with variable amplitude modulation in the 100-700 kHz range. This paper presents and discusses a proposed experiment, with toxicity analysis (DNA Picogreen®) and cell viability (MTT assay) in the radiation-induced HT-29 cell line (colon adenocarcinoma). The data allow us to observe that cellular toxicity effects may occur with exposure to fields produced by argon plasma with intensities on the order of at least 3.2 W / cm2 and exposure times above 3.5 hours continuously. An analysis of cell populations for cell toxicity tests using the Student's t-test did not show significant changes (p <0.05) in the amount of DNA released by the action of radiofrequency, although it has been found that cell viability (MTT) is not significantly altered by long exposures to radiation induced plasma RF signals in 27 MHz (p> 0.34). Cytotoxic effects due to the destruction of cell wall by heating the samples were not detected in any of the tests.

  19. Obtainment of TiO{sub 2} powders solar cells photo electrodes dye sensitized; Obtencao de pos de TiO{sub 2} para fotoeletrodos de celulas solares sensibilizados por corante

    Energy Technology Data Exchange (ETDEWEB)

    Forbeck, Guilherme; Folgueras, Marilena V., E-mail: guilhermeforbeck@hotmail.com [Universidade do Estado de Santa Catarina (PGCE/UDESC), SC (Brazil). Programa de Pos Graduacao em Ciencia e Engenharia de Materiais; Chinelatto, Adilson L. [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil). Programa de Mestrado em Engenharia e Ciencia dos Materiais

    2012-07-01

    Titanium dioxide in its polymorphic anatase phase, presents interesting properties for solar cells photo electrodes dye sensitized such as the forbidden energy band, high refractive index and high constant dielectric. In this study, powders of nanometric titanium dioxide were produced with predominantly the anatase phase and high surface area. We used the sol-gel method, and titanium tetraisopropoxide as a precursor, which was hydrolyzed in nitric acid solution. The obtained powder was heated to 450 ° C, varying the time for each lot (0, 20 or 120 minutes). The powders were characterized by X-ray diffraction, atomic force microscopy and surface area analysis. For all lots nanosized crystallites predominated. It was observed that in the batch with 120min heating an increase rutile content. The TiO{sub 2} with 20min heating showed high surface area, greater than that of TiO{sub 2} as taken reference.

  20. Co-sintering of CGO/NIO-CGO bilayers for solid oxide fuel cell; Co-sinterizacao de bi-camadas anodo/eletrolito para celulas a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Neto, P.P.B.; Grilo, J.P.F.; Souza, G.L.; Macedo, D.A.; Paskocimas, C.A.; Nascimento, R.M., E-mail: pbritoneto@gmail.com [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2012-07-01

    Reducing the operating temperature of solid oxide fuel cells (SOFC) for the range between 500 and 700°C is one of the challenges which more has aroused the interest of research in SOFC in recent years. In this context, the bilayer anode/electrolyte composed of a porous support based on Ni-doped ceria (anode) and a ceria doped gadolinia (CGO) electrolyte, presents itself as one of the half-cell configurations of the most interest towards the production of electricity in the operating logic of a SOFC. In this work, CGO films were successfully prepared on NiO-CGO substrates using the resources of the screen-printing technique. The bi-layers were co-sintered between 1350 and 1450 ° C for 4 h and then characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS). The results showed good adhesion at the film/substrate interface and no cracks in the films. (author)

  1. Polymeric membranes obtained from S-PEEK for application in PEM fuel cells; Caracterizacao de membranas polimericas obtidas a partir dos S-PEEK para aplicacao em celulas combustiveis do tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Ednardo G.; Fiuza, Raildo A.; Catao, Ronei S.; Jose, Nadia M.; Boaventura, Jaime S. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica], e-mail: ednardobarreto@yahoo.com.br, e-mail: raildofiuza@gmail.com, e-mail: roneicatao@ig.com.br, e-mail: nadia@ufba.br, e-mail: bventura@ufba.br; Pepe, Yuri [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Fisica

    2007-07-01

    This work had the objective to develop and to characterize S-PEEK membranes (sulfonated poly ether ether ketone) through chemical and electrochemical analyses. Conductivity test in function of the frequency and tension had been carried through; as well as, the open circuit tension of a fuel cell using the S-PEEK as electrolyte. Additional tests included TGA (Thermogravimetric Analysis), water absorption test, DSC (Differential Scanning Calorimetry), as tools to characterize conducting, thermal and mechanical proprieties of polymeric membrane. (author)

  2. Study of the combined action of gamma radiation and static electric fields in human cells; Estudo da acao combinada de radiacao gama e campo eletrico estatico em celulas humanas

    Energy Technology Data Exchange (ETDEWEB)

    Moron, Michelle Mendes

    2008-07-01

    The basic principle of radiotherapy is the one of maximizing damage to the tumor, while minimizing it in neighboring health tissues. Several strategies have been worked out aiming at increasing cellular radiosensitivity, and among them is the use of exogenous fields. Our goal in this work is the study in human cells of the effect resulting from the association of irradiation with exposure to exogenous static electric fields. The T47D cell line of breast cancer cells was irradiated with gammas in the 0 - 8 Gy doses range. The corresponding survival curve provided information on the radiosensitivity of this cell line. The rate of cell deaths per Gray in the 0 - 8 Gy range exhibited a maximum at 2 Gy, which corresponds to the most efficient irradiation dose. The viability of this T47D cells exposed to both gamma radiation and 1.250 V/cm static electric field (SEF) was about 12% lower than when only irradiated. The sole exposure of the cells to SEF by 24 and 72 hours didn't induce toxicity. Immunofluorescence runs carried out in irradiated normal MRC5 cell line of human lung fibroblast, without and with exposition to a SEF, have quantified the expression of the y- H2AX histone. The amount of phosphorylated histones was approximately 40% higher after irradiation with 2 Gy plus exposure to a SEF by 1 hour, showing that the electric field negatively interfered in the repairing process of the DNA double strand breaks. The flow cytometry analysis with FACS allowed the investigation of a possible interference of radiation and SEF in the cell distributions among the cellular cycle phases. It was found that in T47D cells treated with 1 and 2 Gy by 24 hours the SEF also negatively interfered in the DNA repairing process, as evidenced by the higher accumulation of cells in the S phase. Therefore, it would be possible to conclude that static and exogenous electric fields are able of negatively interfering in the cellular repair and, presumably, in DNA repair. (author)

  3. Study on the performance of Nafion 212 membrane in polymeric electrolyte fuel cells operating with air; Estudo do desempenho da membrana de Nafion 212 em celulas a combustivel de eletrolito polimerico operando com ar

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Adriano C.; Ticianelli, Edson Antonio [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica]. E-mail: edsont@iqsc.usp.br

    2008-07-01

    The operational characteristics of the Nafion 212 membrane (N212) were investigated and compared to the Nafion 112 membrane (N112), both 50 thick, in polymer electrolyte fuel cell (PEFC). The polarization measurements were performed changing the cell and gases humidification temperature and the gases pressure. The kinetic parameters obtained from the polarization curve proved that the cell with membrane N212 showed better performance than membrane N112, when they operating with air at cathode. The electrochemical impedance studies were carried out to make clear the polarization phenomena due to the resistive and diffusive effects that limit the cell performance. At high frequency region is found an arc, which dimension in depends on the current density, whereas at the mid frequency region we can find two loops with different characteristics and both dependent of current density. This behavior becomes evident that there are polarization components linked to resistive processes at high frequency, as well as charge transference and diffusional at mid and low frequency, respectively. (author)

  4. Optimal design of a hybrid photovoltaic and fuel cell power generation system, to supply isolated communities in the Brazilian Amazon; Dimensionamento otimo de sistemas hibridos, com geracao fotovoltaica e celula a combustivel, para atendimento a comunidades isoladas na Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Sergio Batista da

    2010-11-15

    The lack of electricity in isolated communities in the Brazilian Amazon has become one of the greatest barrier for the development of the region. Currently, the main technologies that provide electricity to these communities are diesel generators, batteries and dry cells. These non-renewable energy sources may pose serious problems to the environment and human health and have high maintenance and operational costs. Therefore, the search for renewable energy sources, such as water and sunlight, which are highly abundant in the region, has become a great challenge. This thesis presents the studies on application of solar photovoltaic (PV) and fuel cell (FC) technologies to supply electric power in an uninterrupted manner. Outlined are the technical and cost issues of a pilot project set up in an environmentally protected area, next to Bananal island, located in the Southwestern region of the state of Tocantins. The pilot project relies on PV solar power as the primary source of energy for the production of electricity. The surplus energy is stored in the form of hydrogen produced by electrolysis of the water supplied locally, which is reconverted into electric power by fuel cells during periods when there is little or no sunlight. In this context, the aim of the study was to propose a sizing of a hybrid distributed generation system (HDGS), comprised of a PV system, FC and batteries, that optimizes implementation and operational costs, as a potential source of energy for isolated communities in the Amazon. The work was carried out with the help of simulation software HOMER (Hybrid Optimization Model for Electric Renewable) developed by National Renewable Energy Laboratory (NREL). Simulations and a comparative study were carried out of the technologies and potential configurations that meet the needs of these isolated communities. The results showed an optimal solution of HGDS PV-FC batteries with a reduction in the initial cost of the project in about 60% compared to the sizing system only. The HOMER simulated results also indicated that more than 50% of the costs of the PV-FC-battery HDGS regarded the PV system. (author)

  5. A Hull cell study of a NiW electrolyte and evaluation of its properties; Estudio en celula Hull de un bano electrolitico de NiW y evaluacion de sus propiedades

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Urrutia, I.; Diez, J. A.; Muller, C.; Calvillo, P.

    2009-07-01

    Interest in NiW coatings has grown in recent years due to its favourable properties such as hardness, and resistance to both wear and corrosion, making it one of the actual alternatives to hard chromium coatings. In this work, we have undertaken a Hull cell study, investigating the influence of the metal concentration, temperature, pH and current density on the composition of the alloy formed and its thickness. We have also studied the most important properties of the NiW deposits, including morphology, hardness, and resistance to abrasion and corrosion. (Author) 9 refs.

  6. Development of a computational model applied to a unitary 144 CM{sup 2} proton exchange membrane fuel cell; Desenvolvimento de um modelo numerico computacional aplicado a uma celula a combustivel unitaria de 144 CM{sup 2} tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Robalinho, Eric

    2009-07-01

    This work presents the development of a numerical computer model and methodology to study and design polymeric exchange membrane fuel cell - PEM. For the validation of experimental results, a sequence of routines, appropriate to fit the data obtained in the laboratory, was described. At the computational implementation it was created a new strategy of coupling two 3-dimensional models to satisfy the requirements of the comprehensive model of the fuel cell, including its various geometries and materials, as well as the various physical and chemical processes simulated. To effective assessment of the real cell analogy with numerical model, numerical studies were carried out. Comparisons with values obtained in the literature, characterization of variables through laboratory experiments and estimates from models already tested in the literature were also performed. Regarding the experimental part, a prototype of a fuel cell unit of 144 cm{sup 2} of geometric area was designed, produced and operated at laboratory with the purpose of validating the numerical computer model proposed, with positive results. The results of simulations for the 2D and 3D geometries proposed are presented in the form of polarization curves, highlighting the catalytic layer model based on the geometry of agglomerates. Parametric and sensitivity studies are presented to illustrate the change in performance of the fuel cell studied. The final model is robust and useful as a tool for design and optimization of PEM type fuel cells in a wide range of operating conditions. (author)

  7. Uncertainty of efficiency of a fuel cell with the establishing of suitable instrumentation for his measurement; Incerteza da eficiencia de uma celula a combustivel com o estabelecimento da instrumentacao adequada para a sua medicao

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Sergio Pinheiro de; Trota Filho, Jorge; Couto, Paulo Roberto Guimaraes; Rocha, Adriana da Cunha [Instituto Nacional de Metrologia Normalizacao e Qualidade Industrial (INMETRO), Duque de Caxias, RJ (Brazil)]. E-mail: spoliveira@inmetro.gov.br

    2008-07-01

    This work presents and compares the results obtained from the assessment of the uncertainty of measurement of the energetic efficiency calculations of a PEM unit fuel cell and from the total electrical power of a PEM fuel cell stack. This assessment makes use of three different methods of calculation: the Classical method and the Kragten method, both described in the ISO GUM 95 'Guide to the expression of uncertainty in measurement' and the Monte Carlo method, described in the Supplement 1 to the ISO GUM 95. Concerning the energetic efficiency, both the Classical and Kragten methods presented the same uncertainty values, 0.00029 whereas the Monte Carlo method presented a value of 0.00021. The difference between these two values (0.8 x 10{sup -5}) was greater than the {delta} criteria tolerance established in the Supplement 1 (0.5 x 10{sup -5}). This fact though, has not invalidated the results of the ISO GUM 95, as this work focused on the conservative value of the uncertainty. With respect to the uncertainty of the total electrical power of the fuel cell stack it has been observed that the main contribution for the uncertainty calculation, i.e., the higher uncertainty source (92.8%), was given by the accuracy class of the multimeter employed in the measurements. Additionally to the comparative study of the methods for the uncertainty calculations, this work establishes the correct accuracy class of a multimeter used for the measurement of the given/consumed electric potential by a fuel cell stack, aiming the cost/benefit relation of the process. (author)

  8. Development of solar cells with back surface field made by aluminum paste and belt furnace diffusion; Desenvolvimento de celulas solares com campo retrodifusor formado por pasta de aluminio e difusao em forno de esteira

    Energy Technology Data Exchange (ETDEWEB)

    Marcolino, Juliane Bernardes

    2011-01-15

    Photovoltaics is based on the direct conversion of solar energy into electricity and is a promising alternative to diversify the world's energy matrix. This work aims to develop and analyse the deposition of Al paste by screen printing and firing/diffusion in a belt furnace to produce a BSF region in monocrystalline Si wafers. The diffusion of Al into the substrate was implemented by two different processes. In the first process the diffusion/firing of the Al paste and the firing of the Ag paste was carried out in independent steps. In this case, solar cells with an average efficiency ({eta}{sub average}) of 11.5 % and a maximum of 12.0 % were produced, but with the formation Al clusters in the back surface of the devices. In the second process firing/diffusion of such pastes was done on the same step. In this case, the best results were obtained for a firing/diffusion temperature of 860 deg C and belt furnace speed (V{sub E}) of 150 cm/min and also for 890 deg C and 180 cm/min. For the former parameters, {eta}{sub average} was 12.4 % and the maximum was 12.8 %. For the later, {eta}{sub average} was 12.5 % and the maximum was 12.6 %. Considering a temperature of 900 deg C and V{sub E} of 190 cm/min, {eta}{sub average} was 12.4 %. It was observed that minority carriers diffusion lengths were smaller than the thickness of silicon wafers. Open circuit voltages were 30 mV lower than that from similar cells fabricated at NT-Solar by using high purity Al deposited by e-beam evaporation indicating that the developed process produced low quality BSF. (author)

  9. Processing of strontium-doped lanthanum manganite suspensions for cathode production of the solid oxide fuel cell; Processamento das suspensoes de manganito de lantanio dopado com estroncio para fabricacao do catodo da celula a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, R.; Vargas, R.A.; Andreoli, M.; Seo, E.S.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais. Lab. de SOFC - Insumos e Componentes

    2008-07-01

    The ceramic material, strontium-doped lanthanum manganite (La{sub 0,85}Sr{sub 0,15}MnO{sub 3} - LSM), has been used as cathode in Solid Oxide Fuel Cells (SOFCs). The cathode attainment as component of the SOFCs has been studied for diverse routes of synthesis and thin films forming in Yttria-stabilized zirconia (ZrO{sub 2}/Y{sub 2}O{sub 3} - YSZ) electrolyte. In this work, the LSM was synthesized by the citrate technique and deposited in YSZ substrate using the forming technique wet powder spraying. Rheological studies of suspensions and chemical, physical and microstructural characterizations of LSM powders were made, aiming at the deposition for thin films formation until 50 mum. The half unit cells LSM/YSZ sintered were characterized by scanning electron microscopy, for verification of porosity and adherence. In this sense, this work is a contribution for production of porous cathode using the forming technique wet powder spraying in the SOFCs. (author)

  10. Synthesis of precursor the base of indene for polyelectrolyte an membrane production for application in fuel cell; Sintese de precursores a base de indeno para producao de polieletrolitos e membranas para uso em celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Brum, F.J.B.; Laux, F.N.; Haack, M.S.; Forte, M.M.C. [Universidade Federal do Rio Grande do Sul. Escola de Engenharia, Porto Alegre, RS (Brazil)

    2010-07-01

    Monomers with vinyl bond can be polymerized via a cationic mechanism using acid catalysts. This study aimed to obtain homo and copolymers of styrene and indene via cationic mechanism and the functionalization of sulfonic groups to the production of membranes for fuel cells. Polymers and poly electrolytes were characterized by infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and gel permeation chromatography (GPC/SEC). The degree of sulfonation of the polymers was determined by titration and evaluated for these films to the degree of swelling in water, ion exchange capacity and analysis of electrochemical impedance spectroscopy. Membranes prepared with polyindene and PVA were tested in an apparatus of the fuel cell. (author)

  11. Analysis and development of an ethanol compact reformer for hydrogen production for fuel cell; Analise e modelagem de reformador compacto de etanol para obtencao de hidrodenio para celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, P.R.F.; Oliveira, A.A.M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Combustao e Engenharia de Sistemas Termicos], e-mail: renzo@labcet.ufsc.br, e-mail: amirol@emc.ufsc.br

    2006-07-01

    The objective of this work is to analyze the ethanol steam reforming for hydrogen production in a compact and modular reforming unit designed for the generation of 1 kw of electrical power. For this, initially the thermodynamic limits for the steam reforming of ethanol are calculated in order to assess the limits in the production of hydrogen and other by-products and to select the best values of process stoichiometry, temperature and pressure for maximum hydrogen selectivity and minimum coke formation. In the following, a First and second Laws analysis is performed to analyze the equilibrium conditions of the main chemical reactions and to estimate the magnitude of the heat transfer required by the heating, evaporation, superheating and reforming of ethanol. Then, the catalytic reformer reactor is analyzed and sized, basing the analysis into the application of the equation for the conservation of mass of the chemical species and a model for the chemical kinetics. A basic reactor design is then proposed accompanied by the corresponding sizes and operating conditions. (author)

  12. Performance of a solid oxide fuel cell with cathode containing a functional layer of LSM/YSZ film; Desempenho de uma celula a combustivel de oxido solido com catodo contendo uma camada funcional de filme LSM/YSZ

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Filipe Oliveira; Domingues, Rosana Z.; Brant, Marcia C.; Silva, Charles L.; Matencio, Tulio [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Quimica]. E-mail: filipequiufmg@ufmg.br

    2008-07-01

    Performance of a SOFC may be evaluated by using the AC-Impedance and measuring power (P V x I). The objective of this study was to compare the performance of a fuel cell with LSM as a cathode and another one containing an additional functional composite film LSM/YSZ between the LSM and YSZ. Also it was studied variation in second cell resistance and power according to the temperature, hydrogen flux and operation time. For both cells platinum was used as anode. At 800 deg C was observed, in open current circuit, when the composite layer was introduced a decrease in resistance and high power. These results show an improvement of SOFC cathode performance with the introduction of composite LSM/YSZ layer. The maximum performance of the cell was achieved with 100 mL/min hydrogen flow at 800 deg C. The experiments also showed a performance improvement at 850 deg C. The cell behavior was stable during 318 hours of test. (author)

  13. Performance evaluation of a fuel cell with NiO-YSV anode operating with natural gas; Avaliacao do desempenho de uma celula a combustivel com anodo de NiO YSZ operando com gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Nobrega, Shayenne Diniz da; Vasconcelos, Carmel Suzarte Ayres; Lima, Luiz Rogerio Pinho de Andrade [Universidade Federal da Bahia (UFBa), Salvador, BA (Brazil). Escola Politecnica. Dept. de Ciencia e Tecnologia dos Materiais]. E-mail: shayennedn@yahoo.com.br

    2008-07-01

    Fuel cell is an electrochemical device that converts the chemical energy into electric energy. The natural gas, for its proven improvement in the income of the equipment in relation to other energy ones, has been very used to feed the solid oxide fuel cell (SOFC) in the generation of electric power. Ceramics of Yttria-stabilized zirconia had been used as electrolyte and when supported with nickel oxide they act as anode in the solid oxide fuel cell, due to raised ionic conductivity that these materials present in high temperatures, while lanthanum with strontium and manganite are used as cathode. In the composition of the anode, the concentration of Ni O, acting as catalytic in the YSZ confers high electric conductivity and high electrochemical activity of the reactions, providing the internal reform in the SOFC. In this work, the solid oxide fuel cell, formed by Yttria- stabilized zirconia, nickel oxide, and lanthanum with strontium and manganite were tested in the reform had been prepared samples of electrode/electrolyte for use in SOFC of the natural gas in the presence of low water text, similar condition to the operation of the SOFC, operating in temperatures range from 700 to 800 deg C. This cell also was characterized using the impedance spectroscopy technique. These results allowed the development of components of the current versus voltage. (author)

  14. Development and scale-up of the production process of NovoCell fuel cells; Desenvolvimento e 'scale-up' do processo de producao de celulas a combustivel NovoCell

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Dayse Caldas de; Souza, Adler de; Ferreira, Valdemar Stelita [NovoCell Sistemas de Energia S.A., Santa Barbara D' Oeste, SP (Brazil)]. E-mail: dayse.azevedo@novocell.ind.br

    2008-07-01

    Fuel cells present the potentiality to substitute the engines of internal combustion in vehicles and to supply energy for stationary use. This potentiality, however, not yet reflected in its introduction in the market with regular lines of production, because of its high cost and lack of criteria that demonstrate its reliability and durability. These subjects are the main goals of the programs of development of fuel cells worldwide. NovoCell is a Brazilian company whose objective is to develop and to produce hydrogen/air fuel cells for stationary generation. All the project is guided by the use of technologies/processes and materials that allow production in large scale and to a competitive cost, giving support to a continuous program of innovation and development of the product. In this work the technological solutions developed by the company are presented. (author)

  15. Study of a hybrid system using solid oxide fuel cells (SOFC) and gas turbine; Estudo de um sistema hibrido empregando celula de combustivel de oxido solido (SOFC) e turbina a gas

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Antonio Carlos Caetano de; Gallo, Giulliano Batelochi; Silveira, Jose Luz [UNESP, Guaratingueta, SP (Brazil). Faculdade de Engenharia. Dept. de Energia], e-mail: caetano@feg.unesp.br

    2004-07-01

    In this paper a hybrid solid oxide fuel cell (SOFC) system, applying a combined cycle using gas turbine for rational decentralized energy production is analyzed. The relative concepts about the fuel cell are presented, followed by some chemical and technical information such as the change of Gibbs free energy in isothermal fuel oxidation directly into electricity. This represents a very high fraction of the lower heating value (LHV) of a hydrocarbon fuel. In the next step a methodology for the study of SOFC and gas turbine system is developed, considering the electricity and steam production for a hospital. This methodology is applied to energetic analysis. Natural gas is considered as a fuel. A Sankey Diagram shows that the hybrid SOFC system is a good opportunity to strengthen the decentralized energy production in Brazil. It is necessary to consider that the cogeneration in this version also is a good technical alternative, demanding special methods of design, equipment selection and contractual deals associated to electricity and fuel supply. (author)

  16. Development and testing of the proton exchange membrane fuel cell (PEMFC) for stationary generation; Desenvolvimento e ensaios de uma celula a combustivel de polimero solido (PEMFC) para geracao estacionaria

    Energy Technology Data Exchange (ETDEWEB)

    Ellern, Mara; Boccuzzi, Cyro Vicente [ELETROPAULO, Sao Caetano, SP (Brazil)], e-mail: mara.ellern@aes.com; Ett, Gerhard; Saiki, Gerson Yukio; Janolio, Gilberto [ELECTROCELL, Sao Paulo, SP (Brazil); Jardini, Jose Antonio [Universidade de Sao Paulo (USP), SP (Brazil)

    2004-07-01

    PEM (Proton Exchange Membrane) fuel cell uses a simple chemical reaction to combine hydrogen and oxygen into water, producing electric current in the process. It works something like reversed electrolysis: at the anode, hydrogen molecules give up electrons, forming hydrogen ions (this process is made possible by the platinum catalyst). The proton exchange membrane allows protons to flow through, but not electrons. As a result, the hydrogen ions flow directly through the proton exchange membrane to the cathode, while the electrons flow through an external circuit. As they travel to the cathode through the external circuit, the electrons produce electrical current. At the cathode, the electrons and hydrogen ions combine with oxygen to form water. In a fuel cell, hydrogen's natural tendency to oxidize and form water produces electricity and useful work. No pollution is produced and the only byproducts are water and heat. The huge advance on materials development combined with the growth demand of lower impact on environment is placing the fuel cells on the top of the most promising technologies world-wide. They are becoming in medium term feasible alternatives for energy generators up to energy plants of few MW. (author)

  17. Study of internalization and viability of multimodal nanoparticles for labeling of human umbilical cord mesenchymal stem cells; Estudo de internalizacao e viabilidade de nanoparticulas multimodal para marcacao de celulas-tronco mesenquimais de cordao umbilical humano

    Energy Technology Data Exchange (ETDEWEB)

    Miyaki, Liza Aya Mabuchi [Faculdade de Enfermagem, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Sibov, Tatiana Tais; Pavon, Lorena Favaro; Mamani, Javier Bustamante; Gamarra, Lionel Fernel, E-mail: tatianats@einstein.br [Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil)

    2012-04-15

    Objective: To analyze multimodal magnetic nanoparticles-Rhodamine B in culture media for cell labeling, and to establish a study of multimodal magnetic nanoparticles-Rhodamine B detection at labeled cells evaluating they viability at concentrations of 10 {mu}g Fe/mL and 100{mu}g Fe/mL. Methods: We performed the analysis of stability of multimodal magnetic nanoparticles-Rhodamine B in different culture media; the mesenchymal stem cells labeling with multimodal magnetic nanoparticles-Rhodamine B; the intracellular detection of multimodal magnetic nanoparticles-Rhodamine B in mesenchymal stem cells, and assessment of the viability of labeled cells by kinetic proliferation. Results: The stability analysis showed that multimodal magnetic nanoparticles-Rhodamine B had good stability in cultured Dulbecco's Modified Eagle's-Low Glucose medium and RPMI 1640 medium. The mesenchymal stem cell with multimodal magnetic nanoparticles-Rhodamine B described location of intracellular nanoparticles, which were shown as blue granules co-localized in fluorescent clusters, thus characterizing magnetic and fluorescent properties of multimodal magnetic nanoparticles Rhodamine B. Conclusion: The stability of multimodal magnetic nanoparticles-Rhodamine B found in cultured Dulbecco's Modified Eagle's-Low Glucose medium and RPMI 1640 medium assured intracellular mesenchymal stem cells labeling. This cell labeling did not affect viability of labeled mesenchymal stem cells since they continued to proliferate for five days. (author)

  18. Structural and optical properties of electrodeposited culnSe{sub 2} thin films for photovoltaic solar cells; Propiedades estructurales y opticas de laminas delgadas de CulnSe2 electrodepositadas para su aplicacion en celulas solares fotovoltaicas

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, C.; Herrero, J.; Galiano, F.

    1990-07-01

    Optical an structural properties of electrodeposited copper indium diselenide, CulnSe2, thin films were studied for its application in photovoltaic devices. X-ray diffraction patterns showed that thin films were grown in chalcopyrite phase after suitable treatments. Values of Eg for the CulnSe2 thin films showed a dependence on the deposition potential as determined by optical measurements. (Author) 47 refs.

  19. Effect of the combined action of gamma radiation and static fields in human cells;Efeito da acao combinada de radiacao gama e campo eletrico estatico em celulas humanas

    Energy Technology Data Exchange (ETDEWEB)

    Moron, Michelle Mendes

    2008-07-01

    Our goal is the study in human cells of the effect resulting from the association of irradiation with exposure to exogenous static electric fields. The T47D cell line of breast cancer cells was irradiated with gammas in the 0 8 Gy doses range. The viability of this T47D cells exposed to both gamma radiation and 1.250 V/cm static electric field (SEF) was about 12% lower than when only irradiated. The sole exposure of the cells to SEF by 24 and 72 hours did not induce toxicity. Immunofluorescence runs carried out in irradiated normal MRC5 cell line of human lung fibroblast have quantified the expression of the g-H2AX histone. The amount of phosphorylated histones was approximately 40% higher after irradiation with 2 Gy plus exposure to a SEF by 1 hour, showing that the electric field negatively interfered in the repairing process of the DNA double strand breaks. The flow cytometry analysis with FACS showed that in T47D cells treated with 1 and 2 Gy by 24 hours the SEF also negatively interfered in the DNA repairing process, as evidenced by the higher accumulation of cells in the S phase. (author)

  20. Performance of direct ethanol fuel cells as function of using of compressed air; Desempenho de celulas a combustivel com alimentacao direta de etanol em funcao do uso de ar comprimido

    Energy Technology Data Exchange (ETDEWEB)

    Belchor, P.M. [UFRGS - Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Berns, B.A.; Ferreira, R.C.; Goldbach, A.; Carpenter, D. [FURB - Fundacao Universidade Regional de Blumenau, Blumenau, SC (Brazil)

    2010-07-01

    This paper compared the performance of a direct ethanol fuel cell (CCADE) cathode feeding with air replacing the pure oxygen. The results have shown that the small decreasing of the yield of the cell under both practical and experimental situations, by the use of air replacing pure oxygen, it completely acceptable as function of great diminishing of operational costs. (author)

  1. Absence of genotoxic activity from milk and water boiled in microwave oven in somatic cells from Drosophila melanogaster; Ausencia da atividade genotoxica do leite e agua, fervidos com microondas, em celulas somaticas de Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Cristina das Dores. E-mail: crisddias@yahoo.com.br

    2003-07-01

    This paper reports an experiment for evaluation of the possible genotoxic effects of food prepared in a microwave oven, through the mutation test and somatic recombination, in wings of Drosophila melanogaster. Two crossing have been performed: a standard cross-ST and a high bioactivation cross - HB resulting in marked trans -heterozygote descendents (MH) and balanced heterozygotes (BH). The 72 hours larvas were fed with water and milk boiled both in the microwave oven and in the traditional way. The MH individual wings were analyzed, where the spots can be induced either by mutation or mitotic recombination. The experiment presented negative results related to the genotoxic effects of the water and milk boiled using the microwave oven, in MH descendents of both crossing. Therefore, under these experimental conditions, genotoxic activity were not presented by milk and water boiled in the microwave oven. However, an extensive study using different techniques is necessary to investigate the action of the food prepared in the microwave oven on the genetic material.

  2. Environmental analysis of the proton exchange membrane fuel cell on the subject of life cycle assessment; Analise ambiental da celula a combustivel de membrana trocadora de protons sob o enfoque da avaliacao do ciclo de vida

    Energy Technology Data Exchange (ETDEWEB)

    Fukurozaki, Sandra Harumi

    2006-07-01

    The energy is the fuel of growth and an essential requirement for the socioeconomic development. However, the current production model is based on fossil fuels, considered as threat to man and nature. As for, the relating to the human activities and their effects on the environment, they are handled by the implementation of a more rigid model of environmental control and the mobilization of the society in favor of technologies with less energy impact. In view of this scenario, the Proton Exchange Membrane Fuel Cell - PEMFC has been recognized as a key for the vital need of a clean and efficient energy. Considering the conventional power generation system, their advantages during usage configure its application as an ideal option for several utilities, especially in the mobile sector. Even though, the focus on several environmental evaluations in energy systems is referred back to the initial stage of it use, the employment relating to production of the system and to final destination should be considered, since these also present impacts. In the case of PEMFC, their previous and subsequent phases of use are issues related to the platinum catalysts, which indicates an environmental importance that cannot be overlooked. In this sense, the Life Cycle Assessment has been used to understand and to question the risks and opportunities that are associated to certain product, starting from a systemic concept of their relationships with the environment. It is precisely in this context that the present research intends to present its major contribution, starting from an exploratory study towards the its objectives to provide an environmental analysis of such technology linked to post stage of powder-use of the membrane electrode assembly - MEA, concerning the platinum catalysts, on the subject of Life Cycle Assessment - LCA. To attain such aim, the relationships between energy, environment and development are presented and discussed, as well as, the Fuel Cell technology and the current studies on LCA of PEMFC. Several questions raised up on this issues have contributed in the development of a method of recuperating the PEMFC catalysts and, particularly, for its subsequent environmental evaluation. Among significant results are the importance of LCA, out lined as useful tool for perceiving the weight of environmental matters concerning the platinum and its subsidy strategies relating to the development, consolidation and to the innovation of PEMFC. (author)

  3. Optimization by simulation and development of solar cells with aluminium paste rear emitter and diffusion in conveyor furnace; Otimizacao por simulacao e desenvolvimento de celulas solares com emissor posterior formado por pasta de aluminio e difusao em forno de esteira

    Energy Technology Data Exchange (ETDEWEB)

    Mallmann, Ana Paula

    2011-01-15

    Photovoltaic solar energy is the direct conversion of solar energy into electricity and it has low impact to the environment during electric energy production. The main device of this technology is the solar cell and silicon is the substrate most used. The solar cells are electrically connected and encapsulated in order to form the photovoltaic module. The aims of this thesis are to optimize, develop and to analyse n{sup +}np{sup +} solar cells processed in n type Si-PV-FZ and with aluminum rear emitter formed in belt furnace. The optimization of solar cells by simulation is an important step before the device development. The software PC-1D and another program developed using Visual Basic language were used. Considering a metal grid formed by evaporation technique in vacuum ambient an efficiency of 16.8 % may be achieved. With screen printed grid, 15.8 % efficient solar cells were obtained. From the simulation results it was found that the screen printing metallization may become more viable than evaporation technique because there is low difference in the efficiency and the screen printing is a simpler technique. The experimental optimization of silicon wafers texture process resulted in reflectance of 12 %. This value is typical for monocrystalline silicon with textured surface. Experimental optimization of phosphorus front surface field shows a sheet resistance of (36 {+-} 4) {omega}/ for this region. This region was formed in a thermal step in a conventional furnace with POCl{sub 3}. It was found that after the phosphorus diffusion occurred gettering to specific temperature and time. It was verified that the minority carrier lifetime in the final of processing is similar to the initial value. The influence of steps sequence of front silver paste firing and rear diffusion/firing aluminium paste, of surface passivation and the influence of dry air flow during the aluminium paste diffusion/firing, of aluminium paste diffusion/firing temperature and of belt speed under the fabricated devices electric characteristics were analysed. The aluminum rear emitter n{sup +}np{sup +} silicon solar cells resulted in 29 efficiency up to 9,5 %. The best solar cells were processed under 900 deg C to aluminium paste diffusion/firing and belt speed of 140 cm/min. The efficiency is limited by low values of V{sub OC} and FF reached. It was also verified that the local rear emitter formation results in solar cells with higher efficiency than those with homogeneous emitter. (author)

  4. Behavior of Electrochemically Prepared CuInSe{sub 2} as Photovoltaic Absorber in thin Film Solar Cells; Comportamiento del CuInSe{sub 2} Basado en Precursores Electrodepositados como Absorbente Fotovoltaico en Celulas Solares de Lamina Delgada

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, C.; Martinez, M. A.; Dona, J. M.; Herrero, J.; Gutierrez, M. T. [Ciemat.Madrid (Spain)

    2000-07-01

    Two different objective have been pursued in the present investigation: (1) optimization of the CuInSe{sub 2} preparation parameters from electrodeposited precursors, and (2) evaluation of their photovoltaic behavior by preparing and enhancing Mo/CuInSe{sub 2}/CdS/TCO devices. When Cu-In-Se precursors are directly electrodeposited, the applied potential fit is essential to improve the photovoltaic performance. Suitable absorbers have been also obtained by evaporing an In layer onto electrodeposited Cu-Se precursors. In this case, the substrate temperature during evaporation determines the CuInSe{sub 2} quality. Similar results have been reached by substituting typical Mo-Coated glass substrates by flexible Mo foils. Different TCO tested (ZnO and ITO) have been found equivalent as front electrical contact in the devices. Solar cell performance can be improved by annealing in air at 200 degree centigree. (Author) 46 refs.

  5. Desmoplastic round small cell tumor: a case report of a neoplasm of difficult diagnosis; Tumor desmoplasico de pequenas celulas redondas: relato de um caso de uma neoplasia de dificil diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, Daniel Cury; Totsugui, Joel Takashi; Ditzel Filho, Leo Fernando da Silva; Ioshii, Sergio Ossamu [Pontificia Universidade Catolica do Parana, Curitiba, PR (Brazil); Machuca, Tiago Noguchi [Universidade Federal do Parana, Curitiba, PR (Brazil); Ogata, Alessandro Cury [Hospital Nossa Senhora das Gracas, Curitiba, PR (Brazil)]. E-mail: daniel_ogata@medcenter.com

    2005-07-01

    Desmoplastic Small Round Cell Tumor (DSRCT) is a rare neoplasm of difficult diagnosis, recently described by Gerald et al. There are reports of nearly 101 cases in the literature, being the intra-abdominal region its most common location and children and young adults its preferred age group. This paper reports a case of DSRCT in a young adult of 24 years of age. This patient presented unspecific symptoms of nausea, vomiting and a single episode of haematemesis. Upon physical examination a solid mass on the epigastrium and left hypochondrium was found. Image diagnostic procedures confirmed the existence of the expansive process and also revealed enlarged retroperitoneal lymphonodes. Diagnosis was achieved through videolaparoscopic biopsy. Histologic sections stained with hematoxylin/eosin were inconclusive and immunohistochemical analysis was required to establish the diagnosis. This analysis revealed positivity to epithelial and mesenchymal markers and weak positivity to chromogranin A, characteristic results of DSRCT. Due to the fact that the disease was locally advanced, the patient was treated with chemotherapy (cyclophosphamide and paclytaxel). However, since there was only partial response to the treatment, the patient refused to undergo any second line option of therapy. Presently, the patient is being submitted only to supportive care, within an 18-month follow-up program. (author)

  6. Development of electrode-membrane-electrode assemblies for proton exchange membrane fuel cells (PEMFC) by Sieve printing; Desenvolvimento de conjuntos eletrodo-membrana-eletrodo para celulas a combustivel a membrana trocadora de protons (PEMFC) por impressao a tela

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Alexandre Bodart de

    2008-07-01

    The Sieve Printing process was studied in this work to apply the catalyst layers onto electrolytes utilized in PEMFC. Initially, 25 cm{sup 2} active area MEAs were built for comparison with others MEAs produced by the Spray technique. The two methods produced MEAs that showed current densities higher than 600 mA.cm{sup -2} at 600 mV. A scaling up study for 144 cm{sup 2} of active area MEAs was carried out. For this purpose, a new cell had to be projected for shelter the MEAs in such dimensions. The profile of the gas distribution channels was developed through the computational fluid dynamic tool 'Comsol Multiphysics'. For the design of the bipolar plates of the cell the 'Auto CAD' was used. The 144 cm{sup 2} MEAs made by Spray and by Sieve Printing methods were confronted with commercials MEAs ones of equal dimensions. These commercials MEAs presented better performance at 600 mV, however they were more costly than the solution developed in this study. The new method was showed to be adequate to fabricate low cost MEAs of different geometries and to produce any amount of MEAs for small scale stacks (up to 10 kW). (author)

  7. Action of the chlorophyllin (CHLN) on the double breaking induced by gamma radiation in germinal cells of Drosophila melanogaster; Accion de la clorofilina (CHLN) sobre los dobles rompimientos inducidos por radiacion gamma en celulas germinales de Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Moreno M, A

    2005-07-01

    The chlorophyllin (CHLN) is a derived of the chlorophyll in the one which the atom of Mg is replaced by Cu. It has been broadly used as preservative in those foods, and in the treatment of geriatric patients. The results using different test systems have demonstrated that the CHLN reduces the DNA damage caused by different physical agents or chemical of direct action or insinuation. Another of the properties of the CHLN is it anti carcinogenic action, because it has been that inhibits the carcinogen activity of B1 (AFB1) aflatoxin and it diminishes the incidence of tumors caused for 2-amine-3-methylimidazo [4- 5f] quinoline (IQ) and it inhibits the development of colon cancer during the post-initiation phase. Recently the reports of the activity promoter of the CHLN have been increased on the genetic damage. This effect observed in Salmonella and later on in Drosophila melanogaster using, physical and chemical agents. Presently study determines the action of the CHLN before the genetic effect induced in germinal cells of Drosophila melanogaster by means of the test of the lost one of the X chromosome in ring using two protocols; the first one consisted on pretreatment with CHLN to the male ones and later on to irradiate them and in the second protocol the pretreatment with CHLN administers to the females, in both protocols its were used a litter systems. (Author)

  8. Action of the chlorophyllin before genetic damage induced by gamma radiation in germinal cells of Drosophila; Accion de la clorofilina ante el dano genetico inducido por radiacion gamma en celulas germinales de Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Moreno B, R

    2004-07-01

    The chlorophyllin (CHLN) is a porphyrin of nutritious grade and soluble in water, derived of the chlorophyll. It has been reported that this pigment is a good anti mutagen since it reduces the damage to the DNA caused by physical or chemical agents of direct or indirect action. Their anti carcinogenic action has also been demonstrated when it is administered itself during the induced post-initiation phase by aflatoxins and heterocyclic amines. However in the last decade it has been reported that it also has promoter activity against the genetic damage induced by diverse agents like the alkyl ants of direct and indirect action, the gamma radiation and some heterocyclic amines. This effect has been observed in testing systems like Salmonella, Drosophila, rainbow trout and rodents. In the mouse spermatogonia it has been reported that it reduces the damage to the DNA but with the test of lethal dominant in Drosophila increment the damage induced by gamma radiation. The present study consisted on evaluating the effect of the CHLN in the line germinal masculine of Drosophila by means of the lethal recessive test bound to the sex (LRLS) with the stump Muller 5 and a litters system. Its were pretreated wild males with CHLN and 24 h later were irradiated with 0, 10, 20 and 40 Gy of gamma radiation immediately later were crossed with virgin females of the stump Basc and at 72 h the male was transferred to a cultivation media with three new virgin females, this process repeated three times until completing 3 litters. The F1 it was crossed among itself and in the F2 it was analysed the presence or absence of lethals. The results indicated that the CHLN per se incremented the basal frequency of damage due to the pigment can act as an agent that is inserted to the ADN causing pre mutagenic leisure. Nevertheless with the groups treated with the different doses of gamma radiation the CHLN does not present any protector action, neither promoter except in the litter I of the group treated with 20 Gy where it was observed a promoter effect of genetic damage. (Author)

  9. Experimental energetic analysis of gas natural-powered fuel cell cogeneration plant; Analise energetica experimental de uma planta de co-geracao com celulas a combustivel e gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Jose G.M.; Lopes, Francisco C.; Silva Junior, Fernando R.; Soares, Guilherme F.W.; Serra, Eduardo T. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Power systems based on fuel cells have been considered for residential and commercial applications in energy Distributed Generation (DG) market as these systems can minimize their acquisition, installation and operation high costs. In this work we present an experimental analysis of a power generation system formed by a 5 kW proton exchange membrane fuel cell unit and a natural gas reformer (fuel processor) for hydrogen production, of the CEPEL's Fuel Cell Laboratory. It was determined the electrical performance of the cogeneration system in function of the design and operational power plant parameters. Additionally, it was verified the influence of the activation conditions of the fuel cell electrocatalytic system on the system performance. It also appeared that the use of hydrogen produced from the natural gas catalytic reforming provided the system operation in excellent electrothermal stability conditions resulting in increase of the energy conversion efficiency and of the economy of the cogeneration power plant. The maximum electrical efficiency achieved was around 38% and in all power range unit operated with average potential per single fuel cell higher than 0.60 V. (author)

  10. Polymers and composites synthesis and characterization for application on PEM type fuel cells; Sintese e caracterizacao de polimeros e compositos para aplicacao em celulas a combustivel do tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, Raigenis da Paz; Souza, Daniele Ribeiro; Barreto, Ednardo Gomes; Boaventura Filho, Jaime Soares; Jose, Nadia Mamede [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil)]. E-mail: raigenis@gmail.com

    2006-07-01

    The PEM (proton exchanging membrane) type fuel cell presents good potential for the energy production without the residue generation. However, its manufacture presents high costs for commercial application, mainly due to the electrolyte. Sulfonated Peek (polish-ether-ether-ketone) supported or auto immobilized the in a silicone matrix is an interesting alternative as electrolyte for PEM fuel cells. The commercial PEEK in powder form was functionalized with sulfuric acid, giving the SPEEK (Sulfonated PEEK). The membranes were produced by hot pressing the SPEEK immobilized in a silicone matrix produced by the sol-gel process. The membranes obtained were characterized by DRX, FTIR, TGA, MEV, DSC and protonic conductivity measurements. (author)

  11. Stimulation of murine stem cell proliferation by circulating activities produced during the recovery of a radiation-induced hematopoietic injury. Estimulacion proliferativa de celulas madre hematopoyeticas de raton por actividades circulantes producidas durante la recuperacion de un dano hematopoyetico radioinducido

    Energy Technology Data Exchange (ETDEWEB)

    Grande Azanedo, M.T.

    1989-02-01

    The proliferative activity of CFU-S, low in normal steady state, increases after treatment with different aggressors, i.e., radiation. This stimulation has been attributed in part to a local regulation system of stem cell proliferation, and at least in part to a humoral regulatory system. In the present work it has been investigated the role that circulating activities have in the CFU-S stimulation, by means of in vitro and in vivo incubation assays with diffusion chambers. The results show that bone marrow of mice irradiated with 5 Gy produces in vitro diffusible activities capable of stimulating the CFU-S proliferation. As well with this same dose circulating activities are also produced in vivo. In addition we have observed that these activities are only released during the periods of active hematopoietic regeneration that follow irradiation with moderate doses (1.5 and 5 Gy). In another set of experiments we saw that the stimulating activities are also detected in serum of mice irradiated with 5 Gy. These serum activities modify the proliferative state of very primitive precursors (12 d CFU-S). When the serum activities are added to long term bone marrow cultures the CFU-S are also stimulated to proliferate. Finally, we observed that the radiation-induced serum activities stimulate the proliferation of bone marrow CFU-S when injected into normal mice, suggesting that such activities are involved in the regulation of CFU-S proliferation.

  12. Low power laser effects in cancer cells and fibroblasts submitted the ionizing radiation; Efeitos do laser de baixa potencia em celulas de linhagem tumoral e fibroblastos submetidos a radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Camila Ramos

    2015-07-01

    Cancer is considered a public health problem worldwide. According to Brazil's the National Cancer Institute (INCA), 576,000 new cases of cancer were estimated for 2015 in Brazil, representing the second leading cause of death. Radiotherapy may be a treatment to several of types of cancer, frequently using ionizing radiation to eradicate or prevent the proliferation of tumor cells. This treatment, however, can lead to death of non-tumor cells around in irradiated tissue. Given this, adjuvant therapies that can minimize the side effects of ionizing radiation are of extremely importance. In this context, low power laser (LPL) may be an alternative to modulate the response of healthy cells to ionizing radiation. In this study, cells of human gingival fibroblasts (FMM1) and breast cancer (MDAMB- 231) were exposed to gamma radiation at doses of 2.5 and 10 Gy. After twenty-four hours, cell were irradiated with LPL ( λ= 660 nm, 40 mW and total area of 0.04 cm²) with energy densities of 30, 60, 90, 120 and 150 J/cm². The cell viability was measured during four days, using the trypan blue technique. The influence of LPL on the cell cycle and on expression of the nuclear antigen of cellular proliferation (PCNA) was evaluated by flow cytometry. The expression of β-Galactosidase was the chosen method to assess cell senescence. Considering our adopted parameters, and focusing on the non-tumor cells, we have observed an increase in: 1) cell viability; 2) cell population in phases S and G{sub 2}/M cell cycle; 3) PCNA expression with decrease in senescence. No alterations were observed in the cell viability, with greater population in phases S and G{sub 2}/M cell cycle, while the number of senescent cells and the expression of PCNA were decreased. Therefore, we have concluded that the LPL promoted effects on both cell lineages, with increased cell viability on FMM1 cells, whether cancer cells maintained a decreased proliferation. (author)

  13. Preparation, characterization and evaluation of electrocatalysts supported on functionalized carbon black for polymer exchange membrane fuel cell applications; Preparacao, caracterizacao e avaliacao de eletrocatalisadores suportados em carbono funcionalizado para aplicacao em celulas a combustivel tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Carmo, Marcelo do

    2008-12-18

    The fuel cell technology associated with the growing exigency of low environmental impact energy became prosperous in the world energy scenery. The fuel cell is basically a device that converts directly the chemical energy of a fuel into electrical and thermal energy with a continuous operation by the constant feed of a fuel. Especially, the carbon black Vulcan XC72 is usually employed as an electro catalyst support, and some factors as an accessible and high surface area in order to get maximum particles dispersion, pore size, adequate pore distribution and the presence of functional groups in the carbon black surface are considered fundamental characteristics for an innovative materials development. However, the Vulcan XC72 still reveals insufficient conditions for these purposes. This study consists in the preparation and in the physical chemical characterization of functionalized carbon black by hydrogen peroxide and by polymeric chains with proton conduction properties, and its posterior utilization as electro catalyst support for PEMFC and DMFC application. After the carbon functionalization, an improvement in the carbon black dispersion in water media was observed, a beneficial effect for electro catalyst preparation. It was also observed, that the functional groups and the polymeric chains worked as stabilizers in the particle growing, producing much more homogeneous electrocatalysts, exhibiting smaller average particle size. Especially, in the case of polymeric chains functionalization, a decrease in the ohmic drop was observed for this system, attributed to an improvement in the proton transference. (author)

  14. Stem-cells transplantation for myocardial regeneration Trasplante autólogo de médula ósea: propuesta basada en la evidencia, para un consenso en enfermedad cardiovascular

    Directory of Open Access Journals (Sweden)

    Francisco Cuellar Ambrosi

    2005-04-01

    éneo que se desarrolla después de un "evento índice", el cual produce daño del tejido muscular cardíaco por la pérdida de cardiomiocitos o por la alteración de la capacidad del miocardio para generar una fuerza eficiente para la contracción ventricular. La noxa inicial puede ser de aparición súbita como en el síndrome coronario agudo o insidiosa y gradual como en la enfermedad coronaria crónica y las cardiomiopatías primarias y secundarias. Independiente del factor que genere el síndrome, se produce una serie de respuestas hemodinámicas y neurohormonales con cambios moleculares complejos, que conducen a la progresión de la disfunción ventricular y a mayor pérdida de células contráctiles funcionantes por necrosis o por apoptosis. Las estrategias terapéuticas desarrolladas para interrumpir este círculo vicioso de disfunción miocárdica y remodelación ventricular, cambian las condiciones en que se produce el trabajo miocárdico, con la consecuente mejoría de la enfermedad y de la tasa de supervivencia. Sin embargo, este enfoque terapéutico, conocido como la "aproximación Jurásica", no logra recuperar el tejido lesionado durante el proceso, lo que permite la progresión de la enfermedad hasta llegar a la falla cardíaca terminal y la muerte. Estudios experimentales y clínicos han demostrado que la implantación de células progenitoras derivadas de la médula ósea producen angiogénesis y recuperación de la función cardíaca en pacientes con cardiopatía isquémica aguda y crónica. Con esta terapia se ha demostrado mejoría significativa de la sintomatología, de la capacidad funcional, del estado funcional, del tamaño del defecto de perfusión miocárdica medido por pruebas de medicina nuclear y de la fracción de eyección al igual que disminución del volumen sistólico final del ventrículo izquierdo, sin complicaciones relacionadas con el procedimiento. En conclusión, el trasplante de células progenitoras derivadas de la médula ósea es

  15. Nepfix: on-demand cloud elastic simulation of networks of evolutionary processors

    OpenAIRE

    Orgaz González-Carpio, Pablo

    2015-01-01

    Una Red de Procesadores Evolutivos o NEP (por sus siglas en ingles), es un modelo computacional inspirado por el modelo evolutivo de las celulas, específicamente por las reglas de multiplicación de las mismas. Esta inspiración hace que el modelo sea una abstracción sintactica de la manipulation de information de las celulas. En particu¬lar, una NEP define una maquina de cómputo teorica capaz de resolver problemas NP completos de manera eficiente en tóerminos de tiempo. En la praóctica, se esp...

  16. iDESWEB: Accesibilidad: Discapacidad en la Web

    OpenAIRE

    Serna Berná, Ester; Luján Mora, Sergio

    2012-01-01

    Qué es discapacidad, tipos de discapacidad (visuales, auditivas, motrices, neurológicas o cognitivas, derivadas del envejecimiento, derivadas del entorno), barreras de la discapacidad visual (ceguera, baja visión, daltonismo), productos de apoyo (lector de pantallas, línea de braille, navegadores de voz, pantallas grandes, ampliadores de pantalla), estrategias. tipos de discapacidad (visuales, auditivas, motrices, neurológicas o cognitivas, derivadas del envejecimiento, derivadas del entorno)...

  17. SEVERAL WAYS TO BRIGHTNESS

    OpenAIRE

    Richer, M. G.

    2011-01-01

    Las luminosidades máximas, los cocientes de abundancias químicas y la cinemática interna de las cáscaras nebulares de nebulosas planetarias extragalácticas brillantes no dependen fuertemente de las características de las poblaciones estelares progenitoras en una galaxia. Esta falta de variación sugiere que las nebulosas planetarias más brillantes tienen estrellas progenitoras similares en todas las galaxias, un resultado inesperado teóricamente dada las metalicidades y las historias de formac...

  18. "Discovering the Cell": An Educational Game about Cell and Molecular Biology

    Science.gov (United States)

    Spiegel, Carolina N.; Alves, Gutemberg G.; Cardona, Tania da S.; Melim, Leandra M. C.; Luz, Mauricio R. M. P.; Araujo-Jorge, Tania C.; Henriques-Pons, Andrea

    2008-01-01

    The role of games within education becomes clearer as students become more active and are able to take decisions, solve problems and react to the results of those decisions. The educational board game "Discovering the Cell" ("Celula Adentro"), is based on problem-solving learning. This investigative game attempts to stimulate reasoning and…

  19. Opioid system manipulation during testicular development: results on sperm production and sertoli cells population = Manipulação do sistema opioidérgico durante o desenvolvimento testicular: consequência sobre a produção espermática e a população de células de sertoli

    Directory of Open Access Journals (Sweden)

    Fernanda Mafra Cajú

    2011-04-01

    Full Text Available The Sertoli cell has fundamental importance to the development andmaintenance of spermatogenesis, as well as it has a directly proportional numerical relationship to sperm production. The proliferative period of this cell in rats occurs between 13 days pre-natal and 21 days pos-natal, when is established the final population in adult animals. The Leydig cell can modulate the Sertoli cell proliferation during fetal and neonatal periodƒn throughƒnƒnƒÒ-endorphin. The manipulation of opioidergic system can promote changes in parameters related to development of nervous, endocrine andreproductive systems. By the way, the main purpose of this present work was to compare the effects of the blockade of opioid receptor blocking in Sertoli cells using naltrexone (50 mg kg-1 during fetal and neonatal period in Wistar rats. According to the results, themanipulation of opioidergic system during pre-natal period reduced the total length of seminiferous tubule and Sertoli cell population in adult rats, but sperm production was normal because this cell has had a compensatory response for spermatozoids support capacity.As celulas de Sertoli tem fundamental importancia para o desenvolvimento e manutencao da espermatogenese, bem como possuem uma relacao numerica diretamente proporcional com a producao espermatica. O periodo proliferativo destas celulas em ratos ocorre entre 13 dias pre-natal e 21 dias pos-natal, resultando na definicao da populacao decelulas de Sertoli nos animais adultos. As celulas de Leydig podem modular a proliferacao das celulas de Sertoli durante o periodo fetal e neonatal por meio da ƒÒ-endorfina. A manipulacao do sistema opioidergico durante esta fase pode promover alteracoes em parametros relacionados com o desenvolvimento dos sistemas nervoso, endocrino ereprodutivo. Em virtude disto, o objetivo do presente trabalho foi comparar os efeitos do bloqueio de receptores opioides nas celulas de Sertoli, utilizando o naltrexone (50 mg kg

  20. [Prognostic implications of folliculo-stellate cells in pituitary adenomas: relationship with tumoral behavior].

    Science.gov (United States)

    Tortosa, F; Pires, M; Ortiz, S

    2016-10-01

    Introduccion. A pesar del progreso en la comprension de su patogenia, no se ha encontrado ningun marcador predictivo independiente del comportamiento agresivo de los adenomas hipofisarios que facilite el tratamiento y seguimiento de pacientes afectados. Objetivo. Analizar la expresion de celulas foliculo-estrelladas, mediante inmunomarcacion con proteina S-100, en una serie de pacientes con adenomas hipofisarios seguidos durante al menos siete años. Pacientes y metodos. Estudio retrospectivo de 51 pacientes diagnosticados de adenoma hipofisario entre 2006 y 2008, segun los criterios vigentes de la Organizacion Mundial de la Salud. Se evaluo inmunohistoquimicamente la expresion de S-100 en celulas foliculo-estrelladas, y se correlaciono con parametros clinicorradiologicos e histopatologicos del tumor y la progresion/recurrencia postoperatoria. Resultados. De 51 tumores, 40 se clasificaron como adenomas hipofisarios tipicos y 11 como atipicos. La mayoria de los tipicos mostro celulas foliculo-estrelladas positivas para S-100 (media: 3,93%); los atipicos tenian pocas o ninguna celula S-100 positivas (media: 0,83%). No hubo diferencias significativas en la expresion de S-100 con respecto a la edad o sexo del paciente, tamaño, invasividad o recidiva tumoral posquirurgica. Conclusiones. En el grupo de estudio, a excepcion de los adenomas no funcionantes inmunopositivos para prolactina, con la media mas baja y mas alta de todos los subtipos en ambos grupos (tipicos, 0,25%, frente a atipicos, 9,24%; p = 0,0028), el factor predictivo de agresividad tumoral para los adenomas hipofisarios no esta representado por un bajo valor de S-100 en las celulas foliculo-estrelladas, lo que no permite seleccionar a pacientes para un tratamiento postoperatorio intensivo.

  1. Associação dos níveis de citocinas no pós-transplante de células-tronco hematopoiéticas com a Doença do Enxerto Contra o Hospedeiro aguda Association of cytokine levels with acute graft versus host disease following full match allogeneic stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Jeane E. L. Visentainer

    2005-09-01

    Full Text Available Este estudo foi realizado para investigar se os níveis séricos de sIL-2R, TNF-alfa, IFN-gama, IL-6, IL-10 e TGF-beta1 estavam associados com o desenvolvimento de DECH (Doença do Enxerto Contra o Hospedeiro aguda. Os níveis de citocinas foram seqüencialmente mensurados por Elisa em 13 pacientes que haviam sido submetidos ao transplante alogênico de células progenitoras hematopoiéticas. Os níveis de sIL-2R e IL-10 da 1ª a 15ª semanas pós-transplante foram significativamente maiores no grupo que desenvolveu DECH aguda que naquele sem a doença. Os níveis de sIL-2R aumentaram em direta correlação com a pega do enxerto e ao tempo do DECH aguda, enquanto os níveis de IL-10 aumentaram transitoriamente pós-transplante. A média da concentração de TNF-alfa nas primeiras semanas após o transplante foi maior no grupo que desenvolveu DECH aguda. Além disso, uma queda dos níveis de TGF-beta1 após a pega esteve significativamente associada à DECH aguda. Nenhuma correlação foi encontrada entre DECH aguda e as outras citocinas investigadas. Estes resultados suportam a idéia de que um balanço entre as citocinas derivadas de linfócitos T auxiliadores do tipo 1 e 2 pode ser importante no desenvolvimento e controle da DECH aguda. Embora os níveis de sIL-2R, TNF-alfa, IL-10 e TGF-beta1 tenham sido correlacionados com a DECH aguda, os níveis de sIL-2R ao tempo da pega podem prover um melhor parâmetro para a detecção precoce de DECH aguda após o transplante alogênico.This study was performed to investigate whether the serum levels of sIL-2R, TNF-alpha, IFN-gamma, IL-6, IL-10, and TGF-beta1 are associated with the development of acute GVHD. Serum cytokine levels were sequentially measured by sandwich Enzyme Linked-Immuno-Sorbent Assay (Elisa in 13 patients who had received full match allogeneic stem cell transplantation. Serum sIL-2R and IL-10 levels from the 1st to the 15th week post transplantation were significantly higher in the

  2. Evaluating the effectiveness of an inactivated vaccine from Anaplasma marginale derived from tick cell culture Avaliação da eficácia de uma vacina inativada de Anaplasma marginale derivada de cultura de células de carrapato

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    Pedro Veloso Facury Lasmar

    2012-06-01

    Full Text Available The protective efficacy of an inactivated vaccine from Anaplasma marginale that was cultured in tick cells (IDE8 for use against bovine anaplasmosis was evaluated. Five calves (Group 1 were inoculated subcutaneously, at 21-day intervals, with three doses of vaccine containing 3 × 10(9 A. marginale initial bodies. Five control calves received saline solution alone (Group 2. Thirty-two days after the final inoculation, all the calves were challenged with approximately 3 × 10(5 erythrocytes infected with A. marginale high-virulence isolate (UFMG2. The Group 1 calves seroconverted 14 days after the second dose of vaccine. After the challenge, all the animals showed patent rickettsemia. There was no significant difference (p > 0.05 between the Group 1 and 2 calves during the incubation period, patency period or convalescence period. All the animals required treatment to prevent death. The results suggest that the inactivated vaccine from A. marginale produced in IDE8 induced seroconversion in calves, but was not effective for preventing anaplasmosis induced by the UFMG2 isolate under the conditions of this experiment.Foi avaliada a eficácia de uma vacina protetora para Anaplasma marginale cultivada em células de carrapato (IDE8 para uso contra a anaplasmose bovina. Cinco bezerros (Grupo 1 foram inoculados por via subcutânea com três doses, intervalados de 21 dias, de vacina contendo 3 × 10(9 corpúsculos iniciais de A. marginale inicial. Cinco bezerros do grupo controle receberam apenas solução salina (Grupo 2. Trinta e dois dias após a inoculação final, todos os bezerros foram desafiados com aproximadamente 3 × 10(5 eritrócitos infectados com isolado de A. marginale alta virulência (UFMG2. Os bezerros do Grupo 1 soroconverteram-se 14 dias após a segunda dose da vacina. Após o desafio, todos os animais mostraram riquestsemia patente. Não houve diferença significativa (p > 0,05 entre bezerros do Grupo 1 e 2 em período de incubação, período de patência, ou período de convalescença. Todos os animais necessitaram de tratamento para prevenir a morte. Os resultados sugerem que uma vacina inativada de A. marginale, produzida em IDE8, induz soroconversão em bezerros, mas não é eficaz na prevenção de anaplasmose induzida pelo isolado UFMG2 nas condições deste experimento.

  3. Análise macroscópica e histológica do emprego da poliuretana derivada do óleo de mamona (Ricinus communis aplicada na tíbia de cães em fase de crescimento Macroscopic and histopathologic evaluations of the use of polyurethane resins derived from castor oil (Ricinus communis applied in the tibia of the puppies

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    Patricia Popak Maria

    2003-08-01

    Full Text Available OBJETIVO: Estudar o efeito da poliuretana de mamona aplicada ao osso de cães em crescimento. MÉTODOS: Foram utilizados 12 cães subdivididos aleatoriamente em 3 grupos, os quais receberam o implante de mamona na face medial proximal da tíbia, com análise macroscópica e histopatológica aos 30 (GIII, 60 (GII e 90 (GI dias. RESULTADOS: A poliuretana foi recoberta por uma cápsula conjuntiva fibrosa, não ocorrendo proliferação óssea ao seu redor. CONCLUSÃO: A poliuretana é biocompatível, comportando-se como espaçador biológico em cães. Nesta espécie não ocorre a osteointegração.PURPOSE: To analyze the effects of castor oil derived poliurethane, when applied to bones of puppies. METHODS: Twelve dogs, randomly divided in 3 groups, received a castor oil derived poliurethane at the medial side of the proximal tibia. Gross and histopathologic evaluations were performed at 30 (GIII, 60 (GII and 90 (GI days. RESULTS: The poliurethane was enclosed in a connective fibrous tissue capsule and there was no new bone formation around it. CONCLUSION: The castor oil derived poliurethane is biocompatible and behaves as a biological "stand off" in dogs. Osteointegration does not occur in this species.

  4. Percepción de alimentos en el primer lustro de vida: aspectos innatos, causalidad y modificaciones derivadas de la exposición / Food perception in the first lustrum of life: innate aspects, causality and modifications derived from repeated experiencies.

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    Alejandro Chacón Villalobos

    2011-12-01

    Full Text Available ResumenEste trabajo de revisión bibliográfica describe el concepto de la percepción sensorial innata de los niños y niñas hacia los alimentos, así como los procesos por medio de los cuales esta se modifica y enriquece a través de la interacción y las experiencias alimentarias durante el primer lustro de vida. Además, la importancia del marco afectivo y social en el que este proceso formativo se da. Tanto los espacios y contextos donde se consumen y se promocionan los alimentos durante la edad preescolar, el grado de disciplina impuesta, y el nivel de autodeterminación permitido a los menores tienen, en conjunto, un impacto que perdura a lo largo de toda la vida del ser humano. Por ello, la adecuada gestión de las experiencias sensoriales orientadas a generar improntas positivas en el hogar y en el aula, es de gran importancia para educadores y padres de familia por igual. La neofobia y la aversión a los alimentos, así como el rol de los medios de comunicación, son también abordadas complementariamente.AbstractThis paper review describes the innate sensorial perception of the children towards foods, as well as the processes by means of which this perception modifies and enriches through the interaction and the exposure to food during the first five years of life. It evaluates, in addition, the importance of the affective and social frame in which this formative process occurs. The spaces and contexts in which the foods are both consumed and promoted, the degree of imposed discipline, and the level of self-determination allowed to the minors, have altogether an impact that lasts throughout the entire lifespan of the human being. For this reason, a suitable management of the sensorial experiences oriented to generate positive impressions at the home and at the classroom, is of great importance for both educators and parents. Food neophobia and aversion, as well as the roll of mass media are also explained complementarily.

  5. Escalas empíricas derivadas de la escala de Desviación Psicopática del MMPI, para la evaluación del trastorno antisocial de la personalidad del DSM-III en delincuentes y no delincuentes

    OpenAIRE

    Aluja Fabregat, Antón

    1994-01-01

    Se realiza un análisis de los ítems de la escala de Desviación Psicopática (Pd;50 ítems) del MMPI que más discriminan entre delincuentes diagnosticados del trastorno antisocial de la personalidad (DSM-III), de delincuentes que no tienen el trastorno y estudiantes, del que se resulta dos escalas (Pd-P;24 ítems y Pd-N;33 ítems). Estas escalas obtienen mayor sensibilidad y especificidad que la propia escala Pd respecto al trastorno. Psicométricamente tienen mayor validez y fiabilidad, propiedade...

  6. Técnica da peroxidação para a determinação de metionina em amostras derivadas de ensaios de digestibilidade do trigo e seus subprodutos em frangos de corte The peroxidation technique for methionine determination in derived samples of digestibility assays of the wheat and its by-products in broilers chickens

    Directory of Open Access Journals (Sweden)

    Leonardo Boscoli Lara

    2005-04-01

    Full Text Available Realizou-se um experimento com excreta de aves usando comparar técnicas de hidrólise de aminoácidos com ou sem peroxidação prévia para determinação de metionina. O delineamento experimental foi inteiramente ao acaso, em esquema fatorial 2 x 4 x 8, (métodos x tratamentos x alimentos com três repetições. Sete alimentos oriundos do trigo e uma ração-referência foram utilizados nos quatro tratamentos. Os dois primeiros tratamentos foram baseados na metodologia tradicional de consumo à vontade e utilizou-se o método da alimentação forçada com aves intactas e aves cecectomizadas nos tratamento 3 e 4, respectivamente. Somente a técnica de peroxidação da amostra com ácido perfórmico seguida de hidrólise apresentou resultados confiáveis na análise de biodisponibilidade e conteúdo de metionina do trigo e seu subprodutos.One experiment was conducted with broiler chickens, for evaluation of metabolizable methionine and its levels in the wheat and some of its products, comparing two analyses techniques of methionine determination; hydrolyze and peroxidation with performic acid before hydrolyze. The broilers were randomly distributed in factorial outline 2 x 4 x 8, (methods x treatments x feeds with three repetitions. Seven feeds by-products of wheat grain were used in the four treatments. The first two treatments were set in the traditional methodology of ad libitum consumption and in the treatments three and four, the method of forced feeding was used. The treatment four were tested in the caecectomised chickens. The results of this experiment suggested that only the peroxidation with performic acid before hydrolyze showed good result in measure metabolizable methionine and its levels of wheat and its by-products.

  7. ÍNDICES DE REFRACCIÓN, DENSIDADES Y PROPIEDADES DERIVADAS DE MEZCLAS BINARIAS DE SOLVENTES HIDROXÍLICOS CON LÍQUIDOS IÓNICOS (1-ETIL-3-METILIMIDAZOLIO ETILSULFATO Y 1-METIL-3- METILIMIDAZOLIO METILSULFATO DE 298,15 A 318,15 K

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    Marlon Martínez reina

    2011-12-01

    Full Text Available Se midieron densidades e índices de refracciónde mezclas binarias de agua,metanol y etanol con 1-Etil-3-metilimidazolioEtilsulfato (EMIM-EtSO4 y deetanol con 1-Metil-3-metilimidazolioMetilsulfato (MMIM-MeSO4 en el rangode temperatura de (298,15, 308,15 y318,15 K. Se calcularon los volúmenesde exceso molar (VME y la desviación delíndice de refracción (dh, que se ajustarona una ecuación polinomial de Redlich-Kister de orden cuatro.

  8. Delito de conducción bajo los efectos de bebidas alcohólicas : problemática derivada de la práctica de las pruebas de medición de nivel de impregnación de alcohol

    OpenAIRE

    Coca Gómez, Laura

    2016-01-01

    El presente trabajo recoge algunos problemas que se pueden observar en la práctica en relación con el delito de conducción bajo los efectos de bebidas alcohólicas y el delito de negativa a someterse al control de la alcoholemia. Después de unas breves consideraciones teóricas, el trabajo se centra en el análisis de un supuesto concreto para finalizar extrayendo unas conclusiones al respecto.

  9. El hastial sur de la catedral de León: patología existente derivada de la utilización de azufre en el retacado de grapas y tochos en las obras de restauración realizadas en el siglo XIX

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    Diez García-Olalla, J.

    2015-12-01

    Full Text Available During the restorations carried out in the nineteenth century in the cathedral of Leon, the architect-restorers Juan de Madrazo and Demetrio de los Rios proposed in their projects the use of liquid sulphur to caulk iron or bronze staples, or billets that linked edge elements and solids from the masonry. This solution, not previously used, has produced important construction pathology in the south gable today: cracks in a large number of blocks and partial detachment of them. Some of these detachments have been falling to the court of the temple with the risk to cause harm to people and things. It is worth to point out that this unpublished work has a great importance because, according to the content of the projects of both architects, this practice spread to more parts of the monument, so this localized pathology is expected to manifest itself in other areas with the consequent risk.Durante las restauraciones efectuadas en el siglo xix en la catedral de León, los arquitectos restauradores Juan de Madrazo y Demetrio de los Ríos propusieron en sus proyectos el empleo de azufre líquido para retacar los tochos y engrapados de hierro o bronce que enlazaban los elementos de remate y los sólidos de las fábricas. Esta solución, no utilizada con anterioridad, ha dado lugar a la aparición hoy en día de una importante patología en el hastial sur: la fractura de un gran número de sillares y el desprendimiento parcial de éstos, cayendo al atrio del templo con el consecuente peligro. Este trabajo es una contribución inédita que reviste gran importancia porque, según el contenido de los proyectos de ambos arquitectos, esta práctica se extendió a más partes del monumento, por lo que esta patología localizada es previsible que se manifieste en otras zonas del mismo con el consecuente riesgo.

  10. Dietary vitamin K intake and stability of anticoagulation with coumarins: evidence derived from a clinical trial El consumo de vitamina K y la estabilidad de la anticoagulación con cumarínicos: evidencia derivada de ensayo clínico

    OpenAIRE

    P. Zuchinali; G. C. Souza; M. C. S. de Assis; E. R. Rabelo; L. E. Rohde

    2012-01-01

    Background: Dietary vitamin K intake has been considered a major factor that influences stability of oral anticoagulation (OA) with coumarins. Few studies have evaluated the relationship between amounts of dietary vitamin K intake and stability of anticoagulation. Objective: To assess whether high dietary vitamin K intake is associated to stability of International Normalized Ratio (INR) of the prothrombin time. Methods: We performed a sub-analysis of a randomized clinical trial involving out...

  11. Dietary vitamin K intake and stability of anticoagulation with coumarins: evidence derived from a clinical trial El consumo de vitamina K y la estabilidad de la anticoagulación con cumarínicos: evidencia derivada de ensayo clínico

    Directory of Open Access Journals (Sweden)

    P. Zuchinali

    2012-12-01

    Full Text Available Background: Dietary vitamin K intake has been considered a major factor that influences stability of oral anticoagulation (OA with coumarins. Few studies have evaluated the relationship between amounts of dietary vitamin K intake and stability of anticoagulation. Objective: To assess whether high dietary vitamin K intake is associated to stability of International Normalized Ratio (INR of the prothrombin time. Methods: We performed a sub-analysis of a randomized clinical trial involving outpatients from the anticoagulation clinic of a university hospital. INR and vitamin K intake were prospectively collected at baseline, 15, 30, 60 and 90 days after randomization. Patients were considered with a stable anticoagulation when their INR coefficient of variation was less than 10%. Dietary vitamin K intake was assessed by a food frequency questionnair and a score of intake was derived. Results: We studied 132 patients on chronic OA (57 ± 13 years; 55% males; 23 patients (17% were achieved stable anticoagulation. Stable and unstable patients had no significant differences in baseline characteristics. The dietary vitamin K score over the entire follow-up for stable patients was significantly lower than that for unstable patients (p = 0.012. Discussion: Our findings suggest that INR stability could be achieved with relatively low amounts of dietary vitamin K.Introducción: El consumo dietético de vitamina K ha sido considerado un factor importante que influye en la estabilidad de la anticoagulación oral (AO con cumarina. Pocos estudios han evaluado la relación entre el consumo dietético de vitamina K y la estabilidad de la anticoagulación. Objetivo: Evaluar la relación existente entre la alta ingesta de vitamina K y el mantenimiento de la estabilidade del la Razón Normalizada Internacional RNI. Métodos: Se realizó una subanálisis de un ensayo clínico aleatorizado con pacientes ambulatórios de la clínica de anticoagulación de un hospital universitario. Los datos acerca del RNI y la ingesta de vitamina K fueron recogidos prospectivamente al inicio del estudio, y en los días 15, 30, 60 y 90. Los pacientes fueron considerados estables cuando su coeficiente de variación del RNI fue menor de 10%. La evaluacion de la dieta y la ingesta de vitamina K se obtuvo mediante un cuestionario de frecuencia alimentaria y un sistema de puntuación fue creado para esto. Resultados: Se estudiaron 132 pacientes en tratamiento crónico (57 ± 13 años, el 55% masculino, 23 pacientes (17% lograron anticoagulación estable. Con relación a las características basales, no hubo diferencias entre los sujetos con anticoagulación estable o inestable. La puntuación de la vitamina K de la dieta durante todo el seguimiento de los pacientes se mantuvo significativamente menor entre aquellos con RNI estable cuándo comparado con los inestables (p = 0,012. Discusión: Nuestros hallazgos sugieren que con cantidades relativamente bajas de vitamina K podremos obtener la estabilidad de RNI.

  12. Geometria da valva mitral derivada da ressonância magnética cardiovascular na avaliação da gravidade da regurgitação mitral Cardiovascular magnetic resonance imaging-derived mitral valve geometry in determining mitral regurgitation severity

    Directory of Open Access Journals (Sweden)

    Andre Mauricio Fernandes

    2013-01-01

    Full Text Available FUNDAMENTO: A regurgitação mitral é a doença valvar cardíaca mais comum em todo o mundo. A ressonância magnética pode ser uma ferramenta útil para analisar os parâmetros da valva mitral. OBJETIVO: diferenciar padrões geométricos da valva mitral em pacientes com diferentes gravidades por regurgitação mitral (RM com base na ressonância magnética cardiovascular. MÉTODOS: Sessenta e três pacientes foram submetidos à ressonância magnética cardiovascular. Os parâmetros da valva mitral analisados foram: área (mm2 e ângulo (graus de tenting, altura do ventrículo (mm, altura do tenting (mm, folheto anterior, comprimento posterior do folheto (leaflet e diâmetro do anulo (mm. Os pacientes foram divididos em dois grupos, um incluindo pacientes que necessitaram de cirurgia da valva mitral e o outro os que não. RESULTADOS: Trinta e seis pacientes apresentaram de RM discreta a leve (1-2+ e 27 RM de moderada a grave (3-4+. Dez (15,9% dos 63 pacientes foram submetidos à cirurgia. Pacientes com RM mais grave tiveram maior diâmetro sistólico final do ventrículo esquerdo (38,6 ± 10,2 vs. 45,4 ± 16,8, p BACKGROUND: Mitral regurgitation is the most common valvular heart disease worldwide. Magnetic resonance may be a useful tool to analyze mitral valve parameters. OBJECTIVE: To distinguish mitral valve geometric patterns in patients with different severities of mitral regurgitation (MR based on cardiovascular magnetic resonance imaging. METHODS: Sixty-three patients underwent cardiovascular magnetic resonance imaging. Mitral valve parameters analyzed were: tenting area (mm2 and angle (degrees, ventricle height (mm, tenting height (mm, anterior leaflet, posterior leaflet length and annulus diameter (mm. Patients were divided into two groups, one including patients who required mitral valve surgery and another which did not. RESULTS: Thirty-six patients had trace to mild (1-2+ MR and 27 had moderate to severe MR (3-4+. Ten (15.9% out of 63 patients underwent surgery. Patients with more severe MR had a larger left ventricle end systolic diameter (38.6 ± 10.2 vs 45.4 ± 16.8, p<0.05 and left end diastolic diameter (52.9 ± 6.8 vs 60.1 ± 12.3, p= 0.005. On multivariate analysis, the tenting area was the strongest determinant of MR severity (r= 0.62, p=0.035. Annulus length (36.1 ± 4.7 vs 41 ± 6.7, p< 0.001, tenting area (190.7 ± 149.7 vs 130 ± 71.3, p= 0.048 and posterior leaflet length (15.1 ± 4.1 vs 12.2 ± 3.5, p= 0.023 were larger on patients requiring mitral valve surgery. CONCLUSIONS: Tenting area, annulus and posterior leaflet length are possible determinants of MR severity. These geometric parameters could be used to determine severity and could, in the future, direct specific patient care based on individual mitral apparatus anatomy.

  13. Obtención de un ratón doble knockout de los genes que codifican la isoforma inducible de la sintasa de oxido nítrico y la leptina. Estudio de las consecuencias biológicas derivadas de la ausencia de ambos genes

    OpenAIRE

    Becerril, S.; Frühbeck, G.; Gomez-Ambrosi, J.

    2011-01-01

    La obesidad consiste en un trastorno en el balance energético que resulta del desequilibrio entre la ingesta calórica y el gasto energético. La leptina,, producto del gen ob, controla el peso corporal disminuyendo la ingesta, fundamentalmente, a través de acciones sobre el hipotálamo y aumentando el gasto energético en el tejido adiposo marrón (TAM). El óxido nítrico (NO) es un potente vasodilatador que también participa en el control de la ingesta y es capaz de regular la función de la gras...

  14. Influencia de la movilización rítmica del plexo braquial utilizando el test neurodinámico ULNT1 con variación de los componentes en el tono muscular en pacientes neurológicos con hipertonía en el miembro superior y dificultad para abrir la mano derivada de ello

    OpenAIRE

    Canteras Zubieta, María

    2013-01-01

    RESUMEN El presente trabajo es un proyecto de caso clínico controlado y aleatorizado en el que se pretende estudiar la influencia de la movilización rítmica del plexo braquial mediante el test neurodinámico ULNT1, sobre el tono muscular en pacientes neurológicos con aumento de tono en el miembro superior y dificultad para abrir la mano como consecuencia de ello. Se realizará un análisis estadístico en el que se comprobará la eficacia de la técnica mediante un test chi cuadrado. Asimismo...

  15. Crystallochemical study of amides derived from 6{alpha}, 7{beta}-diidroxivoacapan-17{beta}-oic acid by X-ray diffraction; Estudo cristaloquimico de amidas derivadas do acido 6{alpha}, 7{beta}-di- hidroxivouacapan-17 {beta}-oico por difracao de raios-X

    Energy Technology Data Exchange (ETDEWEB)

    Branco, Marcello Cardoso; Prado Gambardella, Maria Teresa do [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Quimica. Dept. de Quimica e Fisica Molecular

    1995-12-31

    Abstract. The 6{alpha}, 7{beta}-diidroxivoacapan-17{beta}-oic acid (DVA) is a Furane-diterpene isolated from Peterodon genus. It has anti inflammatory and analgesic properties. The purpose of this work is the characterization of amides derived from DVA, in order to understand the relationship between Chemical Structure and Biological Activity of Vouacapanes. The structures of DVA derivatives will be solved by single-crystal X-ray diffraction. (author) 15 refs., 2 figs.

  16. Protección contra babesiosis con una vacuna mixta de B. bovis y B. bigemina derivada de cultivo in vitro en una confrontación de campo. II Inmunización en una área endémica

    OpenAIRE

    Germinal Jorge Cantó Alarcón; Edmundo Enrique Rojas Ramírez; Jesús Antonio Álvarez Martínez; Juan Alberto Ramos Aragón; Juan Joel Mosqueda Gualito; Carlos Agustín Vega y Murguía; Julio Vicente Figueroa Millán

    2003-01-01

    Se evaluó la protección de un inmunógeno bivalente de B. bovis y B. bigemina derivado de cultivo in vitro. Se utilizaron 20 toretes Bos taurus mayores de 18 meses provenientes de una área libre de garrapatas Boophilus, y se trasladaron a una zona endémica, formándose en forma aleatoria dos grupos de 10 animales. Una semana posterior a su llegada, 10 de los animales se vacunaron por vía intramuscular a una dosis de 1 x 107 eritrocitos infectados de cada especie del parásito, los 10 restantes (...

  17. Characterization of the anti tumoral activity of the thiosemicarbazones derived from N(4)-methyl-tolyl-2acetylpyridine And 2-pyridinoformamide and its metal complex: evaluation of the radiopharmaceutical potential; Caracterizacao da atividade antitumoral das tiossemicarbazonas derivadas de N(4)-metil-toluil-2-acetilpiridina e 2-piridinoformamida e seus complexos metalicos: avaliacao do potencial radiofarmaceutico

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Paulo Roberto Ornelas da

    2008-07-01

    Thiosemicarbazones have attracted great pharmacological interest because of their biological properties, such as cytotoxic activity against multiple strains of human tumors. The most studied compounds are pyridine-based because of their resemblance to pyridoxal metabolites that attach to co-enzyme B{sub 6}-dependant enzymes. This work aimed the characterization of the anti tumoral effect of N(4)-methyl-tolyl-2-acetylpyridine and 2-pyridinoformamide-derived thiosemicarbazones and the development of a radiopharmaceutical based on a thiosemicarbazone metal complex for positron emission tomography. In the first phase of this study were synthesized twenty-one thiosemicarbazones, derived from N(4)methyl-2 acetylpyridine and 2-pyridine formamide, as well as their metal complexes (Sn, Ga and Cu). Their cytotoxic potential were evaluated against brain and breast tumor cells in vitro. Our results showed all of them presented powerful cytotoxic and antiproliferative activities against glioblastoma multiform and breast adenocarcinoma at very low concentrations (nanomolar range). Morphological alterations characteristic of apoptosis, such as cell shrinkage, chromatin condensation were observed. Copper chloride was used as control and has presented IC50 at millimolar range suggesting that copper complexation with thiosemicarbazone significantly increases (more than 1 million) the anti tumoral effect of this metal. Due to the potent anti tumoral activity of N(4)-methyl-tolyl-2-acetylpyridine derived thiosemicarbazones and the excellent properties of {sup 64}Cu (T{sub 1/2} = 12.7 hours, {beta}{sup +}, {beta}{sup -}, and EC decay), at the second part for this work it was developed a new imaging agent (radiopharmaceutical) for tumor detection by positron emission tomography (PET). The radiopharmaceuticals were produced in the nuclear reactor TRIGA-IPR-R1 from CDTN, via neutron capture reaction {sup 63}Cu (n,{gamma}) {sup 64}Cu, of the copper complex N(4)-ortho-toluyl-2-acetylpyridine thiosemicarbazone (Culac). The induced specific activity was found to be 5.55 MBq /mg. After irradiation Culac samples were analyzed by the absorption of infrared spectroscopy (IR) to assess the structural integrity. The irradiated compound kept its structural integrity. The maintenance of {sup 64}Culac biological activity was also evaluated by MTT assay on RT2 (wild p53), T98 (mutant p53), MCF-7 (wild p53) and CAE cells (wild p53). The results showed that {sup 64}Culac kept its potent anti tumoral activity against all treated cells presenting IC50 values at nanomolar range. {sup 64}Culac biodistribution studies after intravenous injection in mice bearing Erlich tumor implanted in the paw, showed significant uptake in the tumor paw (tumor/skeletal muscle ratio 6.55), 240 minutes after administration. Histopathological studies have shown mild hepatotoxicity 144 hours (6 days) after intravenous administration of 308 mg/kg of Culac. However, no lethality, behavioural, or feeding changes were observed at this dose. Our results demonstrate that the complex of copper-64 N(4)-ortho-toluyl-2-acetylpyridine thiosemicarbazone ({sup 64}Culac) is a promising radiopharmaceutical for detection of solid tumors by positron emission tomography (PET). (author)

  18. Environmental and ecological architects: Guidelines for the Chilean temperate rainforest management derived from the monito del monte (Dromiciops gliroides conservation Arquitectos ambientales y ecológicos: Pautas para la gestión ambiental del bosque templado lluvioso de Chile derivadas de la conservación del monito del monte (Dromiciops gliroides

    Directory of Open Access Journals (Sweden)

    FRANCISCO E FONTÚRBEL

    2011-06-01

    Full Text Available Land use change is one of the main biodiversity threats. Due to this change, natural habitats such as the South American temperate rainforests have been rapidly degraded, fragmented, and lost. Consequently, the management and conservation of the remaining forest is a priority and having an appropriate environmental policy is mandatory for this purpose. Conservation actions in the temperate rainforest have been addressed from an individual species perspective, giving less attention to the ecosystem level conservation. Moreover, conservation-related information has not reflected yet on environmental policy development. We used the case study of the monito del monte (Dromiciops gliroides to illustrate how our current ecological and conservation knowledge of a species could be used to generate a new environmental policy. Dromiciops gliroides is a forest-dependent species with an important ecological role and quite unique evolutionary status. In order to guarantee the persistence of D. gliroides, we propose two habitat management components to be incorporated in management plans: structure and connectivity. Structure refers to spatial arrangement and key structural elements that determine habitat quality and connectivity refers to functional connectivity at the landscape level. The conservation of the monito del monte might also contribute to the conservation of many other forest-dependent species. By conserving such species it will be possible to conserve the ecological interactions and the eco-evolutionary processes, which ultimately determine the conservation of the temperate rainforest.El cambio de uso de la tierra es una de las principales amenazas a la biodiversidad. Hábitats naturales como el bosque templado lluvioso de Sudamérica han sido degradados, fragmentados y eliminados rápidamente. En consecuencia, es prioritario el manejo y conservación de los remanentes, para lo que es necesario contar con una política ambiental acorde. Las acciones de conservación referentes al bosque lluvioso templado se han abordado mayormente desde una perspectiva de especies individuales, con poco énfasis en la conservación a nivel de ecosistema. Más aún, la información generada en este ámbito tampoco ha permeado en el desarrollo de políticas ambientales. Utilizamos el estudio de caso del monito del monte (Dromiciops gliroides para ilustrar cómo el conocimiento actual en ecología y conservación de una especie puede ser utilizado para generar una nueva política ambiental. Dromiciops gliroides es una especie dependiente del bosque, con un importante rol ecológico y un gran interés evolutivo y de conservación. Para garantizar su persistencia, proponemos dos componentes de gestión del hábitat, a incorporarse en los planes de manejo: la estructura y la conectividad. La estructura hace referencia al arreglo espacial y la presencia de elementos estructurales clave que influyen en la calidad del hábitat, mientras que conectividad se refiere a la conectividad funcional del paisaje. Conservando al monito del monte, se conservarían también otras especies dependientes del bosque y así las interacciones ecológicas y los procesos ecoevolutivos, que determinan finalmente la conservación del bosque lluvioso templado.

  19. Determination of optimum wavelength and derivative order in spectrophotometry for quantitation of hydroquinone in creams Determinação do comprimento de onda ótimo e da ordem da derivada em espectrofotometria para quantificação de hidroquinona em cremes

    OpenAIRE

    Pedro López García; Maria Inês Rocha Miritello Santoro; Anil Kumar Singh; Erika Rosa Maria Kedor-Hackmann

    2007-01-01

    UV derivative spectrophotometry was used for quantitative determination of hydroquinone in creams. The aim of this work was to investigate optimum wavelength and order of derivative, and to validate the proposed spectrophotometric method. The results of standard curves were calculated and statistically analyzed through the least squares method in the interval from 10.0 to 26.0 µg/mL, in the first, second, third and fourth order derivatives. The quantitative determination was carried out by us...

  20. Estrategias en el desarrollo de métodos analíticos para la determinación simultánea de compuestos orgánicos por espectrofotometría derivada Strategies used to develop analytical methods for simultaneous determination of organic compounds by derivative spectrophotometry

    Directory of Open Access Journals (Sweden)

    M. Inés Toral

    2009-01-01

    Full Text Available In this work is proposed, a simple experiment for the simultaneous determination of losartan (L and hydrochlorothiazide (H in synthetic and real samples by derivative spectrophotometry technique. For the students it is relevant to know this technique for simultaneous determinations of drugs, allowing that the students recognize that this technique is simple, rapid and applicable to quality control. This experimental work, it is proposed in order to being applied to undergraduates into laboratories of analytical chemistry. Furthermore, it is given the integration of the theoretical knowledge with the experimental work; this correlation is of interest for the students.

  1. First-derivative ultraviolet spectrophotometric and high performance liquid chromatographic determination of ketoconazole in pharmaceutical emulsions Determinação do cetoconazol em emulsões por espectrofotometria no ultravioleta por derivada de primeira ordem e cromatografia líquida de alta eficiência

    OpenAIRE

    Erika Rosa Maria Kedor-Hackmann; Maria Inês Rocha Miritello Santoro; Anil Kumar Singh; Andréia Cricco Peraro

    2006-01-01

    First-derivative ultraviolet spectrophotometric (Method I) and reversed phase high performance liquid chromatographic (Method II) methods were developed. The validated methods were applied for quantitative determination of ketoconazole in commercial and simulated emulsion formulations. Quantitative first-derivative UV spectrophotometric determinations were made using the zero-crossing method at 257 nm, with methanol as background solvent. Liquid chromatographic analysis was carried out on a L...

  2. Evaluación del efecto de células madre mesenquimales derivadas de tejido adiposo y de medios condicionados en la recuperación motora de ratas con lesión medular / Effect of mesenchymals stem cells derived from human adipose tissue and conditioned medium in motor recovery of rats with spinal cord injury

    OpenAIRE

    Núñez Ríos, Diana Leandra

    2010-01-01

    La médula espinal al permitir la transmisión de impulsos nerviosos, favorece el movimiento en organismos cordados, por lo que un evento traumático se traduce en una disfunción neuronal con pérdida de las facultades motrices. Infortunadamente el porcentaje de regeneración espontánea es de tan solo un 1%, causando una discapacidad severa en las personas afectadas y aumentando los costos en el sistema de salud por el pago de incapacidades y manejo de la enfermedad. Las células madre mesenquimale...

  3. Reflections on the therapeutic use of {sup 223}RaCl{sub 2} for bone metastases resulting from prostate cancer resistant to castration; Reflexiones sobre el uso terapeutico de {sup 223}RaCl{sub 2} para metastasis osea derivada de cancer de prostata resistente a la castracion

    Energy Technology Data Exchange (ETDEWEB)

    Astudillo V, A. J.; Paredes G, L., E-mail: armando.astudillo@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2015-10-15

    In January 2014 the Comision Federal para la Proteccion contra Riesgos Sanitarios of the Ministry of Health in Mexico, authorize the use of {sup 223}RaCl{sub 2} as the first radiopharmaceutical emitter α for therapeutic purposes in cases of bone metastases resulting from prostate cancer resistant to castration. The paper analyzes the main variables that affect the metrological traceability using activity meters to evaluate the gamma activity of {sup 223}RaCl{sub 2} in hospitals, because it has a chain of complex decay with alpha, beta and gamma emitters, so was important to verify if a gamma activity measurement for a multiple emitter is reliable to determine the total alpha absorbed dose to bone in a patient. (Author)

  4. Derivados 1,3,4 - Tiadiazóis Mesoiônicos

    OpenAIRE

    Pires, Amanda do Rocio Andrade

    2011-01-01

    Resumo: As celulas cancerosas sao tolerantes a muitos tratamentos devido a aquisicao de mecanismos de resistencia a apoptose e por apresentarem um programa proliferativo anormal. Neste contexto, o desenvolvimento de novos farmacos com atividade antitumoral e o entendimento de seu mecanismo de acao e essencial. Os compostos mesoionicos tem mostrado atividade contra diferentes linhagens tumorais, a qual tem sido atribuida as suas caracteristicas fisico-quimicas. Dentre estes compostos, os deriv...

  5. Estudo de permeaçao cutânea in vitro do ácido kójico

    OpenAIRE

    Gomara, Fernanda de Lacerda

    2013-01-01

    Resumo: Desordens no processo melanogenico podem causar as hiperpigmentacoes, sendo a de maior frequencia o melasma. O acido kojico e um dos despigmentantes topicos utilizados no tratamento destas hipercromias. A acao de um produto dermatologico deve ser topica, nao devendo atingir niveis sistemicos. Um dos fatores que pode definir o nivel de acao, topica ou sistemica, e o veiculo. Neste contesto, o presente trabalho teve por objetivo avaliar o grau de permeacao cutanea in vitro, celula de F...

  6. Relação da variação genética do EXON3 de HLA-E, EXONS2, 3 e 4 de HLA-G e tratamento de reprodução assistida

    OpenAIRE

    Gelmini, Geórgia Fernanda

    2011-01-01

    Resumo: A implantacao embrionaria humana e um processo extremamente complexo que requer habilidade do embriao de se implantar no utero e receptividade adequada do endometrio materno. O progresso nos estudos das moleculas HLA-E e HLA-G levantou dados importantes quanto a funcao dessas moleculas na interface materno-fetal e suas possiveis interacoes com receptores inibidores de celulas NK que resultariam numa regulacao negativa da resposta imune materna, auxiliando a manutencao do feto durante ...

  7. Life cycle assessment (LCA) methodology: importance in the integration of the fuel cell technology type PEMFC (proton exchange membrane fuel cells); Metodologia da analise de ciclo de vida: importancia na insercao da tecnologia de celula a combustivel do tipo PEMFC (membrana polimerica trocadora de protons)

    Energy Technology Data Exchange (ETDEWEB)

    Fukurozaki, Sandra Harumi; Seo, Emilia Satoshi Miyamaru [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)). Centro de Ciencia e Tecnologia de Materiais], e-mail: shfukuro@ipen.br

    2004-07-01

    To improve the standard of society's quality of life, it is necessary to improve the quality of distributed energy and its inherent services within a sustainability process. Among different technological routes that produce more sustainable energy are the fuel cells - also known as combustible batteries. The Global Environment Facility (GEF) has identified the fuel cells as a potential technology to reduce, in the future, the effect of greenhouse gases in both developed and developing countries. Although there are various types of fuel cells, the most used technology for research studies on fuel cells is the Polymer Electrolyte Fuel Cells (FEMFC). However, economic issues - related to the high cost of the membrane's materials and of the catalysts of groups of platinum metals - are still some of the obstacles that need to be overcome for this technology to be more accessible. There are also socio-environmental aspects related to the impacts caused by the extraction, the use and the destination of these metals. Taking in consideration the challenges of complying with the demands of the market and the society as well as with the growing tendency of more rigid patterns of environmental control, the objective of the present work is to show the tool of environmental management - Life Cycle Assessment (LCA) - and its importance on the pursuit for socio-economic and environmental alternatives feasible to the recycling of the catalysts of platinum of the PEMFC. This way, it intends to collaborate to the progress of the knowledge about environmental and socio-economic subjects related to the productive process of the PEMFC. (author)

  8. Preparation and characterization of Nafion - TiO{sub 2} composite electrolytes for application in proton exchange membrane fuel cells; Preparacao e caracterizacao de eletrolitos compositos Nafion - TiO{sub 2} para aplicacao em celulas a combustivel de membrana de troca protonica

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Bruno Ribeiro de

    2008-11-06

    The fabrication and characterization of Nafion - TiO{sub 2} composites, and the use of such electrolytes in PEM (Proton Exchange Membrane) fuel cell operating at high temperature (130 deg C) were studied. The operation of a PEM fuel cell at such high temperature is considered as an effective way to promote fast electrode reaction kinetics, high diffusional transport, and high tolerance to the carbon monoxide fuel contaminant. The polymer Nafion{sup R} is the most used electrolyte in PEM fuel cells due to its high proton conductivity. However, the proton transport in Nafion is dependent on the water content in the polymeric membrane. The need of absorbed water in the polymer structure limits the operation of the fuel cell to temperatures close to 100 deg C, above which Nafion exhibits a fast decrease of the ionic conductivity. In order to increase the performance of the electrolyte operating at high temperatures, Nafion-TiO{sub 2} composites have been prepared by casting. The addition of titania hygroscopic particles to the polymeric matrix aims at the enhancement of the humidification of the electrolyte at temperatures above 100 deg C. Three types of titania particles with different specific surface area and morphology have been investigated. Nafion-based composites with the addition of titania nanoparticles, in the 2.5-15 wt.% range, with nearly spherical shape and specific surface area up to approx. 115 m{sup 2}g{sup -1} were found to have higher glass transition temperature than the polymer. Such an increase improves the stability of the electrolyte during the fuel cell operation at high temperatures. The addition of titania-derived nanotubes results in a pronounced increase of the performance of PEM fuel cell operating at 130 deg C. In this composite, the high specific surface area and the tubular shape of the inorganic phase are responsible for the measured increase of both the absorption and retention of water of the composite electrolyte. Nonetheless, the polarization curves of fuel cell using the composite electrolytes exhibited an increase of the ohmic polarization associated with the addition of the insulating titania particles. As the chemical structure of Nafion was observed to be insensitive to the addition of the inorganic particles, the high performance of the composite electrolytes is a result of competing effects: the decrease of the electrical conductivity and a higher thermal stability or water absorption/retention capacity. The experimental results suggest that the Nafion-TiO{sub 2} composites are promising electrolytes for PEM fuel cells operating at temperatures above approx. 100 deg C. (author)

  9. Development of a membrane electrode as assembly production process for proton exchange membrane fuel cell (PEMFC) by sieve printing; Desenvolvimento de processo de producao de conjuntos eletrodo-membrana-eletrodo para celulas a combustivel baseadas no uso de membrana polimerica conditora de protons (PEMFC) por impressa a tela

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio, Rafael Nogueira

    2010-07-01

    Energy is a resource that presents historical trend of growth in demand. Projections indicate that future energy needs will require a massive use of hydrogen as fuel. The use of systems based on the use of proton exchange membrane fuel cell (PEMFC) has features that allow its application for stationary applications, automotive and portable power generation. The use of hydrogen as fuel for PEMFC has the advantage low pollutants' emission, when compared to fossil fuels. For the reactions in a PEMFC is necessary to build membrane electrode assembly (MEA). And the production of MEAs and its materials are relevant to the final cost of k W of power generated by systems of fuel cell. This represent currently a technological and financial barriers to large-scale application of this technology. In this work a process of MEAs fabrication were developed that showed high reproducibility, rapidity and low cost by sieve printing. The process of sieve printing and the ink composition as a precursor to the catalyst layer were developed, which allow the preparation of electrodes for MEAs fabrication with the implementation of the exact catalyst loading, 0.6 milligrams of platinum per square centimeters (mgPt.cm{sup -2}) suitable for cathodes and 0.4 mgPt.cm{sup -2} for anode in only one application step per electrode. The ink was developed, produced, characterized and used with similar characteristics to ink of sieve printing build for other applications. The MEAs produced had a performance of up to 712 m A.cm{sup -2} by 600 mV to 25 cm{sup 2} MEA area. The MEA cost production for MEAs of 247.86 cm{sup 2}, that can generate 1 kilowatt of energy was estimated to US$ 7,744.14 including cost of equipment, materials and labor. (author)

  10. Resistance to the ionizing radiation in cells of human melanoma. Role of the antioxidant enzymes and of the free radicals of the oxygen; Resistencia a la radiacion ionizante en celulas de melanoma humano. Papel de las enzimas antioxidantes y de los radicales libres del oxigeno

    Energy Technology Data Exchange (ETDEWEB)

    Medina, V.; Cricco, G.; Massari, N.; Nunez, M.; Martin, G.; Mohanad, N.; Gutierrez, A.; Bergoc, R.; Rivera, E. [Laboratorio de Radioisotopos, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires, Junin 956, Buenos Aires (Argentina); Crescenti, E.; Croci, M. [Instituto de Inmunooncologia, Cordoba 3200, Buenos Aires (Argentina)]. e-mail: vmedina@ffyb.uba.ar

    2006-07-01

    The malignant melanoma is a highly aggressive and potentially lethal type of skin cancer. Previously we have reported that the cellular human lines of melanoma WM35 and M15 are resistant to the ionizing radiation (IR). The histamine (HA) although it has a regulator effect of the cellular proliferation in these lines, it is not capable of to modify the response to the IR like it makes with other malignant cellular lines. To investigate the bases of the radioresistance of the melanoma lines we have studied in the WM35 the production of free radicals of oxygen (ROS), the activity of the antioxidant enzymes and their modifications by action of the IR and of the HA. In studies in vitro the cells were treated with HA 10 {mu}M from 20 hs before being irradiated with a dose of 2 Gy (source {sup 137}Cs, dose rate 7.7 Gy/min). The ROS levels, superoxide anion (O{sub 2}{sup -}) and hydrogen peroxide (H{sub 2}O{sub 2}) its were measured by flow cytometry using fluorescent coloring and the activity of dismutase superoxide (SOD), Catalase (CAT) and Glutathion Peroxidase (GPx) its were determined by spectrophotometric techniques and the protein levels by Western blot. The results indicate that in the cells WM35 the HA increases the production of H{sub 2}O{sub 2} in 96% and it diminishes lightly (17%) the levels of O{sub 2}{sup -} . On the contrary, the IR diminishes the levels of H{sub 2}O-2 in 47% and it increases in 46% those of O{sub 2}{sup -}. In the irradiated cells the HA power the decrease of H{sub 2}O{sub 2} produced by the IR. The variation of the enzymes activity is coincident with these changes in the levels of ROS: the treatment with HA increases the activity of SOD and it diminishes that of CAT in cells without irradiating; on the other hand, in the irradiated cells the HA it diminishes the SOD significantly. On the base of these results we can conclude that the levels of H{sub 2}O{sub 2} are directly related with the sensitivity of the cells WM35 to the IR. The HA is able to modulate the activity of the antioxidant enzymes and the levels of ROS. The IR activates cellular mechanisms that take to the radioresistance of these cells and that its interfere and/modifying the biological response mediated by the HA. (Author)

  11. Induction of genetic recombination in the lambda bacteriophage by ultraviolet irradiation of the Escherichia Coli cells. III. Role of the ruvA and recN genes; Induccion de recombinacion genetica en el bacteriofago lambda por irradiacion ultravioleta de las celulas de Escherichia Coli. III. Papel de los genes ruvA and recN

    Energy Technology Data Exchange (ETDEWEB)

    Alcantara D, D. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1987-05-15

    The objective of this work is to determine the paper of the genes ruvA and recN in the stimulation of the recombination of Lambda for UV irradiation of Escherichia Coli, taking into account that both genes are inducible, they belong to the group of genes that participate in the SOS response and that a deficiency in its expression reduces the capacity to repair and recombiner the DNA. (Author)

  12. Preparation and characterization of PVA/SSA membranes with Al{sub 2}O{sub 3} nanoparticles for fuel cell applications; Preparacao de caracterizacao de membranas de PVAL/SSA na presenca de nanoparticulas de Al{sub 2}O{sub 3} para aplicacao em celulas de combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Paula N.; Pires, Alfredo T.N. [Grupo de Estudo em Materiais Polimericos - POLIMAT - UFSC, Florianopolis, SC (Brazil); Catarino, Margarida; Brandao, Lucia; Tanaka, Alfredo; Mendes, Adelio [Faculdade de Engenharia da Universidade do Porto, Porto (Portugal)

    2011-07-01

    In the present study, PVA/SSA membranes were prepared with and without the addition of Al{sub 2}O{sub 3} nanoparticles. Sulfosuccinic acid (SSA) was used as the crosslinking agent. Membranes were prepared with different amounts of SSA (26, 43 and 55 wt.%) and with 5 and 10 wt.% of nanoparticles. Crosslinking was performed at 90 degree C during 1.5 h. Membranes were analyzed by infrared spectroscopy, thermal analysis, water absorption, ion exchange capacity (IEC) and proton conductivity. The results showed that control of the crosslinking conditions, IEC value, water absorption and polymer structure are of significant importance to obtain a set of properties suitable for application in proton exchange membrane fuel cells. (author)

  13. Synthesis and evaluation in vitro in cancer cells AR42J of the radiopharmaceutical {sup 99m}Tc-Tyr{sup 3}-Octreotide-dendrimer similar of somatostatin; Sintesis y evaluacion in vitro en celulas de cancer AR42J del radiofarmaco {sup 99m}Tc-Tyr{sup 3}-Octreotido-dendrimero analogo de la somatostatina

    Energy Technology Data Exchange (ETDEWEB)

    Orocio R, E.

    2013-07-01

    The objective of this project was preparing a multimeric system through the conjugation of several molecules of the peptide Tyr{sup 3}-Octreotide to a dendrimer molecule based on Poly-amidoamine (PAMAM), as well as radiolabeled with {sup 99m}Tc and evaluating its behavior like new radiopharmaceutical similar of somatostatin. The dendrimer PAMAM generation 3.5 that possesses terminal groups of sodium carboxylate, was functionalized to peptide Tyr{sup 3}-Octreotide through a reaction of peptide coupling with HATU (hexafluorophosphate (V) of 1-oxide-3-(bis(dimethylamino)methylene)-3H-[1,2,3]triazole[4,5-b]pyridine) as activating agent of carboxylate groups using the Size Exclusion Chromatography (Sec) as purification method. The product was characterized by Ultraviolet visible spectrophotometry, Mid-infrared and Far-infrared, Elemental analysis, Energy dispersive X-ray spectroscopy, Scanning electron microscopy, Thermogravimetry and Differential scanning calorimetry. The radiolabeled with {sup 99m}Tc was carried out using a direct method that involves the reduction of the anion TcO{sub 4}{sup -} with stannous chloride, so that the dendrimer is capable of coordinating to the technetium forming a chelate compound. The radiochemical purity of the radiolabeled compound was determined by thin layer chromatography using a sodium chloride solution to 20% (m/v) as mobile phase and was verified by molecular exclusion chromatography. The radiolabeled compound was possible to obtain it with a radiochemical purity superior to 90%. Also, the specific and not specific union was evaluated of the synthesized compound in mouse pancreas cancer cells AR42J, positive to somatostatin receptors, showing specific recognition for this receptors type with high cellular internalization. The biodistribution studies were carried out in BALB/c mice at different post injection times and in nude mice with induced tumors AR42J. The results showed that the {sup 99m}Tc-PAMAM-Tyr{sup 3}-Octreotide is excreted by via renal as hepatobiliary with a tumor capture of 4.12±0.6 D.I.g{sup -1} at the two hours of having been administered, which shows their potential as new radiopharmaceutical similar of somatostatin for the tumors detection of neuroendocrine origin. (Author)

  14. Study of the oxygen reduction reaction using Pt-Rare earths (La, Ce, Er) electrocatalysts for application of PEM fuel cells; Estudo da reacao de reducao do oxigenio utilizando eletrocatalisadores a base de Pt-terras raras (La, Ce, Er) para aplicacao em celulas a combustivel tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Thiago Bueno

    2013-07-01

    The complexity of the oxygen reduction reaction (ORR) and its potential losses make it responsible for the most part of efficiency losses at the Fuel Cells. For this reaction the electrocatalyst witch is most appropriated and shows better performance is platinum, a noble metal that elevates the cost, raising barriers for Fuel Cells technology to enter the market. First this work focuses on reducing the amount of platinum used in the cathode, by being replaced by rare earths. The most common methods of synthesis involves a large amount of steps and this work proposed to prepare the electrocatalyst through a simpler way that would not take so many steps and time to be done. Using an ultrasound mixer the electrocatalyst was prepared mixing platinum supported on carbon black and the rare earths lanthanum, cerium and erbium oxides to be applied in a half-cell study of the ORR. The Koutecky-Levich plots shows that among the electrocatalysts prepared the Pt80Ce20/C had the catalytic activity close to the commercial BASF platinum on carbon black, suggesting that the reaction was taken by the 4-electron path. As found in some works in literature, among the rare earth used to study the ORR, cerium is the one witch shows the better performance because it is able to store and provide oxygen. This feature is of great interest for the ORR because this reaction is first order to the oxygen concentration. Results show that is possible to reduce the amount of platinum maintaining the same electrocatalyst activity. (author)

  15. Cultivation and irradiation of human fibroblasts in a medium enriched with platelet lysate for obtaining feeder layer in epidermal cell culture; Cultivo e irradiacao de fibroblastos humanos em meio enriquecido com lisado de plaquetas para obtencao de camada de sustentacao em culturas de celulas da epiderme

    Energy Technology Data Exchange (ETDEWEB)

    Yoshito, Daniele

    2011-07-01

    For over 30 years, the use of culture medium, enriched with bovine serum, and murines fibroblasts, with the rate of proliferation controlled by irradiation or by share anticarcinogenic drugs, has been playing successfully its role in assisting in the development of keratinocytes in culture, for clinical purposes. However, currently there is a growing concern about the possibility of transmitting prions and animals viruses to transplanted patients. Taking into account this concern, the present work aims to cultivate human fibroblasts in a medium enriched with human platelets lysate and determine the irradiation dose of these cells, for obtaining feeder layer in epidermal cell culture. For carrying out the proposed objective, platelets lysis has standardized, this lysate was used for human fibroblasts cultivation and the irradiation dose enough to inhibit its duplication was evaluated. Human keratinocytes were cultivated in these feeder layers, in culture medium enriched with the lysate. With these results we conclude that the 10% platelets lysate promoted a better adhesion and proliferation of human fibroblasts and in all dose levels tested (60 to 300 Gy), these had their mitotic activity inactivated by ionizing irradiation, being that the feeder layers obtained with doses from 70 to 150 Gy were those that provided the best development of keratinocytes in medium containing 2.5% of human platelet lysate. Therefore, it was possible to standardize both the cultivation of human fibroblasts as its inactivation for use as feeder layer in culture of keratinocytes, so as to eliminate xenobiotics components. (author)

  16. Application of PtSn/C catalysts and Nafion SiO{sub 2} membranes in direct ethanol fuel cell at high temperatures; Aplicacao de catalisadores PtSn/C e membranas Nafion SiO{sub 2} em celulas a combustivel de etanol direto em elevadas temperaturas

    Energy Technology Data Exchange (ETDEWEB)

    Dresch, Mauro Andre

    2014-07-01

    This work has as objective to evaluate anodes and electrolytes in direct ethanol fuel cells (DEFC) operating at high temperature (130 deg C). As anode materials, electrocatalysts based on Pt Sn/C were prepared by Modified Polyol Method with various Pt:Sn atomic ratios. Such methodology promotes self organized electrocatalysts production with narrow particle size distribution and high alloying degree. The electrocatalysts were characterized by XRD, and CO stripping. The results showed that these materials presented high alloying degree and Eonset CO oxidation at lower potential as commercial materials. As electrolyte, Nafion-SiO{sub 2} hybrids were synthesized by sol-gel reaction, by the incorporation of oxide directly into the ionic aggregates of various kinds of Nafion membranes. The synthesis parameter, such sol-gel solvent, membrane thickness and silicon precursor concentration were studied in terms of silica incorporation degree and hybrid mechanical stability. Finally, the optimized anodes and electrolytes were evaluated in DEFC operating at 80 - 130 deg C temperature range. The results showed a significant improvement of the DEFC performance (122 mW cm{sup -2}), resulted from the acceleration of ethanol oxidation reaction rate due to anode material optimization and high temperature operation once the use of hybrids possibilities the increase of temperature without a significant conductivity loses. In this sense, the combination of optimized electrodes and electrolytes are a promising alternative for the development of these devices. (author)

  17. Activación de celulas supresoras de la respuesta de hipersensibilidad tardía en ratones BALB/c infectados o vacunados con Leishmania mexicana pifanoi Activation of supressor cells of delayed hypersensitivity response in BALB/C mice infected or immunized with Leishmania mexicana pifanoi

    Directory of Open Access Journals (Sweden)

    Hilda A. Pérez

    1985-12-01

    Full Text Available Los ratones BALB/c inmunizados SC con promastigotes no viables de Leishmania mexicana pifanoi, desarrollaron respuestas de hipersensibilidad tardia (RHT contra el parásito. En contraposición, los ratones BALB/c infectados crónicamente con L.m. pifanoi y aquellos inmunizados IV con una dosis supraóptima de parásitos muertos, mostraron inhibición de la RHT. La supresión de la RHT en los animales infectados, estuvo precedida por un estado transitorio de inmunidad celular, manifestado durante la fase inicial del desarrollo de las lesiones (4-12 semanas. La inhibición de la RHT observada en los animales infectados o inmunizados con dosis supraóptimas, fue causada por un mecanismo activo, transferible a receptores singénicos a través de las células esplénicas de los donantes suprimidos. La población de células supresoras fue no adherente a "nylon", sensible al tratamiento con un suero anti-timocitos de ratón y C', y de acción específica sobre la RHT contra antígenos leishmánicos. Se propone que la ocurrencia de células T supresoras de la RHT en los animales infectados crónicamente o inmunizados con dosis supraóptimas, es causada por el exceso de carga antigénica. Esta última, en el caso de los animales infectados, secundaria a una falla primaria en el control inmunológico de la población parasitaria.A T suppressor cell population that specifically shut down delayed hypersensitivity responses (DHR to the parasite was found in both BALB/c mice chronically infected with Leishmania mexicana pifanoi and in naive mice which had received a single IV supraoptimal dose of killed parasites. At the early phase of infection mice exhibited a transitory state of cell-mediated immunity against the parasite that was abrogated when lesions reached their accelerated phase of growth. Results suggest that in both infected and high-dose immunized mice, the activation of T suppressor cells of DHR is related to antigen overload.

  18. Study of synthesis routes and processing of NiO-YSZ ceramic composite for use as anode in solid oxide fuel cell (SOFC); Estudo de rotas de sintese e processamento ceramico do composito NiO-YSZ para aplicacao como anodo em celulas a combustivel do tipo oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Yoshito, Walter Kenji

    2011-07-01

    This study aim the definition of synthesis and ceramic processing conditions of the anodic component suitable for operation of SOFC, i.e, homogeneous distribution of NiO in YSZ matrix and porosity after reduction above 30%. The selected synthesis routes included the co-precipitation in ammonia media, mechanical mixing of powders and combustion reaction from nitrate salts. The characterization techniques of powders included the X-ray diffraction, scanning and transmission electron microscopy, laser diffraction, nitrogen gas adsorption technique (BET) and Helium pycnometry. The obtained results indicated that the loss of Ni{sup 2+} in co-precipitation process, due to the formation of complex [Ni(NH{sub 3}){sub n}]{sup 2+}, can be minimized by controlling the pH around 9.3, keeping the concentration of nickel cation in the solution to be precipitated around 0.1M. In the mechanical mixing method the best condition of powder dispersion, without differential sedimentation, was obtained for zeta potential values at pH around 8.0, fixing the dispersant concentration at 0.8%. For the combustion synthesis it was observed that when stoichiometric and twofold stoichiometric urea was used, amorphous phase was formed and a higher surface area was attained in the final products. Employing the fuel-rich solution condition, crystallization of the powder was observed and the relative intensity of reflections of XRD patterns increased with excess of fuel, due to increasing the reaction temperature. Sinterability studies of pellets prepared from powder synthesized by the three routes described above showed the temperature around 1300 deg C for maximum rate densification and porosity between 6.0 and 14%. Reduction results of the composites confirmed that the reduction kinetics occurs in two steps. The first one with a linear behavior and controlled by chemical reaction on the surface. The second reduction step is the reduction that is controlled by gas diffusion in micro pores, generated by reduction of nickel oxide, decreasing the rate of reduction. (author)

  19. Study of the Nafion quantity effect in membrane and electrodes assemblies (MEAs) of 50 cm{sup 2} used in type proton exchange membrane (PEM) fuel cell operating with H{sub 2}/Air; Estudo do efeito da quantidade de Nafion em MEAs de 50 cm{sup 2} utilizadas em celula a combustivel tipo PEM operando com H{sub 2}/ar

    Energy Technology Data Exchange (ETDEWEB)

    Profeti, Demetrius; Colmati, Flavio; Carlindo, Adao A.J.; Paganin, Valdecir A.; Gonzalez, Ernesto R.; Ticianelli, Edson A. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica]. E-mail: dprofeti@iqsc.usp.br

    2008-07-01

    The performance of a proton exchange membrane fuel cell (PEMFC) was investigated with the aim at characterizing the effects of the Nafion. content on the scale-up of the electrodes from 5 to 50 cm{sup 2}. It is observed that a diminution of the single cell performance occurred when the electrode area is increased from 5 to 50 cm{sup 2}. The tests carried out with different Nafion. contents, and fuel cell and humidifiers at the same temperature (T{sub cell}=T{sub H2}=T{sub air}=70 deg C) showed a slightly decrease of the fuel cell performance compared to the tests performed at different temperatures (T{sub cell}=70 deg C, T{sub H2}=85 deg C, T{sub air}=75 deg C). In the study of the variation on the Nafion. contents, the higher performance up to a current density of 0.8 A cm-2 is obtained with the 35.5 wt.% Nafion.. On the other hand, at higher current densities values, the performance of the fuel cells is very similar for the 31.0, 35.5 and 39.4 wt.% Nafion contents. (author)

  20. Studies on the efficiency during reactivation of a generation system based on natural gas reformer and a 5 k W fuel cell; Estudos de eficiencia durante reativacao de um sistema de geracao baseado em reformador de gas natural e celula a combustivel de 5 kW

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Francisco da Costa; Furtado, Jose Geraldo de Melo; Silva Junior, Fernando Rodrigues da; Serra, Eduardo Torres [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)]. E-mail: fcl@cepel.br

    2008-07-01

    Fuel cell based power generation systems have been pointing as promising technology for stationary applications mainly to supply power to critical loads. Among several types of fuel cells the Polymer Electrolyte Membrane Fuel Cells (PEMFC) are the main type used around the world. Nowadays reformers are widely employed to produce hydrogen for fuel cells. The Fuel Cell Laboratory of CEPEL has a power plant based on a 5 kW PEMFC and a natural gas reformer. For a long time the PEMFC was inoperable due to reformer malfunctioning and during this time the full power availability of PEMFC was lost due to deactivation of its catalytic sites. In most cases this deactivation is reversible. So it was started a reactivation process aiming to recover the full operational condition of the PEMFC unit. During this process the gas flow relationship and efficiency of the reformer were studied. An analysis of the PEMFC reactivation was conducted where it was noted that the reactivation took place as expected. During the reactivation process the PEMFC and the whole system efficiency were analyzed. The results suggest that the PEMFC can reach efficiency compatible with conventional power generation systems thus allowing PEMFC technology to compete with these energy sources in point of efficiency. (author)

  1. Study and development of membrane electrode assemblies for Proton Exchange Membrane Fuel Cell (PEMFC) with palladium based catalysts; Estudo e desenvolvimento de conjuntos membrana-eletrodos (MEA) para celula a combustivel de eletrolito polimerico condutor de protons (PEMFC) com eletrocatalisadores a base de paladio

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio, Rafael Nogueira

    2013-07-01

    PEMFC systems are capable of generating electricity with high efficiency and low or no emissions, but durability and cost issues prevent its large commercialization. In this work MEA with palladium based catalysts were developed, Pd/C, Pt/C and alloys PdPt/C catalysts with different ratios between metals and carbon were synthesized and characterized. A study of the ratio between catalyst and Nafion Ionomer for formation of high performance triple-phase reaction was carried out, a mathematical model to implement this adjustment to catalysts with different relations between metal and support taking into account the volumetric aspects of the catalyst layer was developed and then a study of the catalyst layer thickness was performed. X-ray diffraction, Transmission and Scanning Electron Microscopy, X-ray Energy Dispersive, Gas Pycnometry, Mercury Intrusion Porosimetry, Gas adsorption according to the BET and BJH equations, and Thermo Gravimetric Analysis techniques were used for characterization and particle size, specific surface areas and lattice parameters determinations were also carried out. All catalysts were used on MEAs preparation and evaluated in 5 cm{sup 2} single cell from 25 to 100 °C at 1 atm and the best composition was also evaluated at 3 atm. In the study of metals for reactions, to reduce the platinum applied to the electrodes without performance losses, Pd/C and PdPt/C 1:1 were selected for anodes and cathodes, respectively. The developed MEA structure used 0,25 mgPt.cm{sup -2}, showing power densities up to 550 mW.cm{sup -2} and power of 2.2 kW{sub net} per gram of platinum. The estimated costs showed that there was a reduction of up to 64.5 %, compared to the MEA structures previously known. Depending on the temperature and operating pressure, values from US$ 1,475.30 to prepare MEAs for each installed kilowatt were obtained. Taking into account recent studies, it was concluded that the cost of the developed MEA is compatible with PEMFC stationary application. (author)

  2. Preliminary analysis for implementation of a hybrid solar-wind system with storage of electrical energy generated through electrolytic hydrogen and fuel cells; Analise preliminar para implementacao de um sistema hibrido solar-eolico com armazenamento da energia eletrica gerada atraves de hidrogenio eletrolitico e celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Daniel Gabriel; Furlan, Andre Luis; Lopes, Davi Gabriel [Universidade Estadual de Campinas (FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica], e-mail: danielg@fem.unicamp.br; Silva, Ennio Peres; Apolinario, Fernando Resende [Universidade Estadual de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Lab. de Hidrogenio; Silva, Maria Eugenia Vieira da; Rocha, Paulo Alexandre Costa [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia Mecanica e de Producao; Codeceira Neto, Alcides [Companhia Hidro Eletrica do Sao Francisco (CHESF), Recife, PE (Brazil)

    2008-07-01

    Due to relevance of the study and applicability of hybrid electric power generation from solar photovoltaic and wind power in Brazil, the present paper aims to introduce briefly the importance of technical and economic comparison of two electrical energy storage technologies (batteries versus H2 + fuel cell) and also to indicate the previous difficulties related to this possible application. In this context, it was intended a partnership between State University of Campinas - UNICAMP, the Federal University of Ceara - UFC and Hydro Electric Company of the Sao Francisco - CHESF in the meaning of makes viable an implementation. (author)

  3. Exploratory study on the integration of fuel cell systems inside the chloro-soda plants for utilization of industrial hydrogen; Estudo exploratorio da integracao de sistemas de celula a combustivel dentro das plantas de cloro-soda para utilizacao do hidrogenio industrial

    Energy Technology Data Exchange (ETDEWEB)

    Braga, Jose Mauro Fernandes [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Escola de Engenharia]. E-mail: jmfbraga@oi.com.br; Seidl, Peter [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Pirro e Longo, Waldimir [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Nwcleo de Estudos Estrategicos (NEST)

    2008-07-01

    This work aims to demonstrate the economic viability of the application of industrial hydrogen in fuel cell systems by analyzing the advantages and disadvantages of this investment in hydrochloric acid/ sodium hydroxide plants. Using the Present Liquid Value and the Real Options Theory an economic evaluation will be made of the integration of fuel cell system in these plants, based on investment cost, volatility, among other parameters. (author)

  4. Comparative analysis between two systems to generate electric energy for isolated community in the interior of the Amazon state: fuel cells with natural gas reformer versus diesel generation; Analise comparativa entre dois sistemas de geracao de energia eletrica para a comunidade isolada no interior do estado do Amazonas: celula a combustivel com reformador para gas natural versus gerador diesel

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Paula Duarte; Bergamini, Cristiane Peres; Camargo, Joao Carlos; Lopes, Daniel Gabriel [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Fac. de Engenharia Mecanica; Esteves, Gheisa Roberta Telles [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Nucleo de Pesquisas e Estudos Ambientais; Silva, Ennio Peres da Silva [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Fisica Gleb Wataghin

    2004-07-01

    Although great part of the domestic territory is already supplied with electric energy, still there are many regions where the system is precarious or nonexistent, generically called isolated communities. In the majority of the cases these communities are supplied with Diesel oil generators and the substitution of this fuel for available alternative energy in the localities has been object of study of some institutions of research spread throughout the country. Currently, the use of fuel cells has been strongly argued in the generation of electric energy associated with the local energy necessity, from the use of a regional fuel and this is due to the high efficiency of allied energy conversion to the low ambient impacts that this equipment offers. Most of the different types of fuel cells use hydrogen as a fuel to produce electricity, and it is extracted from renewable or non-renewable sources of energy. Then, the article has the objective of comparing in first analysis the energy efficiency and the cost between the two systems: the ones used currently in the great majority of the isolated communities, constituted of a Diesel engine-generator system, with Natural Gas Reformer System/ Purifier of Hydrogen/ Fuel Cell/ and to analyze if such project presents characteristics that qualifies it to get the carbon credits proposed in the Mechanism of Clean Development. (author)

  5. Cost analysis of electrical power from an ethanol reformer and the fuel cell in the development of productive activities in the community Pico do Amor, MT, Brazil; Analise do custo da energia eletrica proveniente de um reformador de etanol e celula a combustivel no desenvolvimento de atividades produtivas na comunidade Pico do Amor/MT

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Davi Gabriel; Teixeira, Andre Frazao; Lopes, Daniel Gabriel; Cavaliero, Carla Kazue Nakao [Universidade Estadual de Campinas (DE/FEM/UNICAMP), SP (Brazil). Faculdade de Engenharia Mecanica. Departamento de Energia; Instituto Aqua Genesis, Campinas, SP (Brazil); Hytron, Campinas, SP (Brazil)

    2010-07-01

    This work has the objective to analyze the impact of the cost of from an ethane reformer / fuel cell in the family income considering the development of two productive activities selected by the community itself: the production and marketing of cassava flour and 'rapadura', a typical brazilian candy. The community energy demand was analyzed to achieve the results; estimated the energy cost from the implemented system and the money from the selling of the cassava flour and 'rapadura' produced with this electricity; the study of sensibility of the ethanol price in the electrical energy cost was done too, and the cassava flour and 'rapadura' in the family funds. From the results, it was verified that the electrical energy cost has a 16,4% impact in the family gross income and a net value around R$ 260,85/family, indicating that the community will have enough funds to pay for the energy and also will rise the amount of money for each family. Besides, the comparative analyze of the cost of the electricity from the ethanol/fuel cell reformer and photovoltaic systems shows that, considering only the maintenance and operation costs, the first one should be more attractive than the second one. (author)

  6. Evaluation and application of PEMFC fuel cell's technologies developed at IPEN applied to a 500 W{sub e} fuel cell stack; Avaliacao e aplicacao de tecnologias de celulas a combustivel tipo PEMFC desenvolvida no IPEN em um modulo de 500 W{sub e} de potencia nominal

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Edgar Ferrari da

    2009-07-01

    This work is part of a research project on PEMFC technologies carried out in IPEN to develop and optimize a 500 W{sub e} fuel cell stack. The MEAs scaling up from 25 cm{sup 2} to 144 cm{sup 2} produced by the method of sieve printing; computational fluid dynamics by computer simulation of gas flow channels in bipolar plates using COMSOL{sup R} program and the use of Pt/C electrodes developed by alcohol reduction method in single cells were used to build a stack of 500 W{sub e} nominal power for possible commercial applications, produced with national technology and industrial support. A 100 hours fuel cell's test was carried out in a 144 cm{sup 2} single cell to study the stability of the MEA fabricated by sieve printing method. This single cell showed good stability within this period of time. The developed stack has reached the maximum power of 574 W{sub e} at 100 A (694.4 mA cm{sup -2}). The operating power of 500 W{sub e} was obtained at 77.7 A (540.1 mA cm{sup -2}) and potential of 6.43 V, with efficiency of 43.3%. In terms of cogeneration, the thermal power or generated heat by the stack was 652 W{sub t}. The initial estimated cost for the 500 W{sub e} stack was about R$ 4,500.00, considering only the used materials for its construction. (author)

  7. Analysis for impedance electrochemistry 'on-line' of membrane/electrode assemble (MEA) of protons exchange membrane fuel cells (PEMFC); Analise por impedancia eletroquimica 'on-line' de conjuntos eletrodos/membrana (MEA) de celulas a combustivel a membrana polimetrica (PEMFC)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Antonio Rodolfo dos

    2007-07-01

    This work reports results of studies and characterization on membrane electrode assemblies (MEAs) for proton exchange membrane fuel cell (PEMFC). Some cell operation conditions and different processes of MEA production were investigated. The electrochemical impedance spectroscopy technique (EIS) (in situ - 0 to 16 A) was used 'on-line' as a tool for diagnosis, concerning the cell performance. The EIS measurements were carried out with a FC350 Fuel Cell EIS System (GAMRY), coupled to a PC4 potentiostat/galvanostat and connected to the electronic load (TDI) for 'on-line' EIS experiments (100 mHz - 10 kHz, dU = 5 mV). MEAs with 25 cm{sup 2} surface area, using PtM/C 20% (M Ru, Sn or Ni) electrocatalysts were manufactured using the alcohol reduction process (ARP). The catalytic ink was applied directly into the carbon cloth (GDL) and pressed in the Nafion membrane (105). MEAs using Pt/C and Pt Ru/C 20% from E-TEK electrocatalysts were manufactured by comparison. All the cathodes were sprayed with Pt/C 20% from E-TEK. The noble metal concentrations used were set to 0.4 mg Pt.cm{sup -2} at the anode and 0.6 mg Pt.cm{sup -2} at the cathode (E-TEK). Nyquist diagrams of the MEAs with Pt/C and PtRu/C from E-TEK or PtM/C (M = Ru, Sn or Ni) ARP showed essentially the same ohmic resistances for the MEAs. This fact can be explained by suppression of agglomerates during the MEA preparation process or by the homogeneity of the anchored electrocatalysts at the carbon surface. It could also be observed, at low current densities, that there was a significant performance difference between the electrocatalysts from E-TEK and those prepared with the alcohol reduction process. The polarization curves results confirmed that the Pt M/C (M = Ru, Sn or Ni) ARP showed an activity increase for the methanol and ethanol fed cells. The technique of EIE was shown efficient for the evaluation of the method preparation of MEAs and the acting of the cell, the results of EIE showed coherence in the choice of the model the electric circuit for MEAs using hydrogen, methanol and ethanol. This coherence indicates that other resistances no considered in the model are not relevant in the total resistance of MEAs. (author)

  8. Effects of {gamma} ({sup 60}Co) and {beta} ({sup 90}Sr) radiations in Chinese hamster ovarian cells (CHO-K1): induction of micronuclei and cell death; Efeitos das radiacoes {gamma} ({sup 60}Co) e {beta} ({sup 90}Sr) em celulas de ovario de hamster chines (CHO-K1): inducao de micronucleos e morte celular

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Daniella

    2003-07-01

    Among various types of ionising radiation, the beta emitter radionuclides are involved in many sectors of human activity, such as nuclear medicine, nuclear industries and biomedicine, with a consequent increased risk of accidental, occupational or therapeutic exposure. Despite their recognized importance, there is little information about the effect of beta particles at the cellular level when compared to other types of ionizing radiation. Thus, the objective of the present study was to evaluate the genotoxic and cytotoxic effects of {sup 90}Sr, a pure, highly energetic beta source, on CHO-K1 cells and to compare them with data obtained with {sup 60}Co. CHO-K1 cells irradiated with different doses (1.0, 2.5, 5.0, 7.5 Gy) of {sup 60}Co (0.34 Gy.min{sup -1}) and {sup 90}Sr (0.23 Gy.min{sup -1}) were processed for analysis of clonogenic death, induction of micronuclei (MN) and necrotic and apoptotic death. The survival curves obtained for both types of radiation were better fitted by the linear-quadratic model and were similar. However, the cytogenetic results showed that both the proportion of micronucleated cells and the magnitude of radioinduced lesions demonstrated by the analysis of MN distribution were significantly higher in cells irradiated with {sup 60}Co than in cells irradiated with {sup 90}Sr, whereas {sup 90}Sr was more damaging than {sup 60}Co in terms of cell death induction. Necrosis was the major type of death observed in CHO-K1 cells. The data obtained suggest that the low incidence of micronucleated cells after exposure to {sup 90}Sr may be a consequence of selective elimination of severely damaged cells from the population by the necrotic process at a higher rate than observed with {sup 60}Co exposure. The data obtained also demonstrated the need to use several parameters for a better estimate of cellular sensitivity to the action of genotoxic agents, which would be important in terms of radiobiology, oncology and therapeutics. (author)

  9. Evaluation of umbilical cord mesenchymal stem cells labeling with superparamagnetic iron oxide nanoparticles coated with dextran and complexed with Poly-L-Lysine; Avaliacao da marcacao de celulas-tronco mesenquimais de cordao umbilical com nanoparticulas superparamagneticas de oxido de ferro recobertas com Dextran e complexadas a Poli-L-Lisina

    Energy Technology Data Exchange (ETDEWEB)

    Sibov, Tatiana Tais; Mamani, Javier Bustamante; Pavon, Lorena Favaro; Cardenas, Walter Humberto; Gamarra, Lionel Fernel, E-mail: tatianats@einstein.br [Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Miyaki, Liza Aya Mabuchi [Faculdade de Enfermagem, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Marti, Luciana Cavalheiro; Sardinha, Luiz Roberto [Centro de Pesquisa Experimental, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Oliveira, Daniela Mara de [Universidade de Brasilia - UnB, Brasilia, DF (Brazil)

    2012-04-15

    Objective: The objective of this study was to evaluate the effect of the labeling of umbilical cord vein derived mesenchymal stem cells with superparamagnetic iron oxide nanoparticles coated with dextran and complexed to a non-viral transfector agent transfector poly-L-lysine. Methods: The labeling of mesenchymal stem cells was performed using the superparamagnetic iron oxide nanoparticles/dextran complexed and not complexed to poly-L-lysine. Superparamagnetic iron oxide nanoparticles/dextran was incubated with poly-L-lysine in an ultrasonic sonicator at 37 deg C for 10 minutes for complex formation superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine by electrostatic interaction. Then, the mesenchymal stem cells were incubated overnight with the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine and superparamagnetic iron oxide nanoparticles/dextran. After the incubation period the mesenchymal stem cells were evaluated by internalization of the complex superparamagnetic iron oxide nanoparticles/dextran/polyL-lysine and superparamagnetic iron oxide nanoparticles/dextran by Prussian Blue stain. Cellular viability of labeled mesenchymal stem cells was evaluated by cellular proliferation assay using 5,6-carboxyfluorescein-succinimidyl ester method and apoptosis detection by Annexin V- Propidium Iodide assay. Results: mesenchymal stem cells labeled with superparamagnetic iron oxide nanoparticles/ dextran without poly-L-lysine not internalized efficiently the superparamagnetic iron oxide nanoparticles due to its low presence detected within cells. Mesenchymal stem cells labeled with the complex superparamagnetic iron oxide nanoparticles/dextran/polyL-lysine efficiently internalized the superparamagnetic iron oxide nanoparticles due to greater presence in the cells interior. The viability and apoptosis assays demonstrated that the mesenchymal stem cells labeled and not labeled respectively with the superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine continue to proliferate over seven days and the percentage of cells in early or late apoptosis is low compared to the percentage of live cells over the three days. Conclusion: Our results showed that the use of poly-L-lysine complexed with superparamagnetic iron oxide nanoparticles/dextran provides better internalization of these superparamagnetic iron oxide nanoparticles in mesenchymal stem cells Thus, we demonstrated that this type of labeling is not cytotoxic to the mesenchymal stem cells, since the viability and apoptosis assays showed that the cells remain alive and proliferating. The efficiency of this type of labeling in mesenchymal stem cells can provide non-invasive methods for monitoring these cells in vivo. (author)

  10. Modifier action of the chlorophyllin of the mutagenesis induced by the ethyl-nitroso-urea (ENU) in germinal cells of Drosophila melanogaster; Accion modificadora de la clorofilina de la mutagenesis inducida por la etil-nitroso-urea (ENU) en celulas germinales de Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Morales N, I

    2006-07-01

    The cupro-sodium chlorophyllin (CCS) it is a soluble porphyrin in water that it includes in its it structures a copper atom instead of the magnesium that has the chlorophyll. Diverse experiments have demonstrated that it possesses a potent activity, reducing or inhibiting, the DNA damage caused by physical and chemical agents of direct action or insinuation. Most of the knowledge about their anti genotoxic activity has been obtained using somatic cells of different organisms, on the other hand it is known very little of their effect in germinal cells. At the moment in the Drosophila laboratory of the ININ it is investigating the protective action of the CCS in germinal cells, with these studies has been observed that its administration to females that were crossed with males irradiated with 20 Gy of gamma radiation, promotes the induction of lethal dominant in the embryonic and post-embryonic states causing a diminution in the viability egg-adult. With the test of lethal recessive bound to the sex one has evidence that it increases the basal frequency of lethal recessive and it doesn't reduce those induced by radiation. In contrast, with the present investigation when the CCS was administered to males that later on were treated with ethyl-nitroso-urea (ENU) caused a reduction of the lethal frequency in all the monitored cellular states, but only it was significant in the post-meiotic cells. On the contrary, when the CCS was administered to the female ones and then they crossed with males treaties with ENU, it was observed a tendency to increase the lethal ones in all the cellular types. With both protocols the CCS caused a diminution of the sterility. The fact that the CCS has antagonistic activities, it deserves special attention to investigate with different protocols and systems, the conditions in that this pigment can work as a true antimutagenic and/or anti carcinogenic before being able to him to propose as a chemopreventor. (Author)

  11. Evidence about chlorophyllin can function as an inhibitor or promoter of induced genetic damage by gamma radiation in Drosophila somatic cells; Evidencia de que la clorofilina puede funcionar como un inhibidor o un promotor del dano genetico inducido por radiacion gamma en celulas somaticas de Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel, A.E.; Cruces, M.P.; Zimmering, S.I. [Departamento de Biologia, ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    The irradiation of the individuals that had been feed during 24 hours with a chlorophyllin solution at 5 % was delayed from 0 until 4 days. The protector effect of chlorophyllin persisted by 3 days and it appears to coincide with the stage when stopping the mitotic divisions in the imagal disk. Within of the same cellular population, it was demonstrated that chlorophyllin can function as an inhibitor, in the case of simple stains mwh or a potentiator in the case of twin stains and the flr type stains. It was planned an explanation for these results. (Author)

  12. Fluorescein isothiocyanate labeled, magnetic nanoparticles conjugated D-penicillamine-anti-metadherin and in vitro evaluation on breast cancer cells; Avaliacao do isotiocianato de fluoresceina marcado, das nanoparticulas magneticas conjugadas da D-penicilamina antimetaderina e in vitro nas celulas do cancer de mama

    Energy Technology Data Exchange (ETDEWEB)

    Akca, Ozlet; Unak, Perihan; Medine, E. Ylker [Ege University (Turkey). Institute of Nuclear Sciences. Department of Nuclear Applications; Sakarya, Serhan [Adnan Menderes University (Turkey). ADUBILTEM Science and Technology Research and Development Center; Ozdemir, Caglar; Timur, Suna [Ege University (Turkey). Science Faculty. Department of Nuclear Applications

    2011-07-01

    Silane modified magnetic nanoparticles were prepared after capped with silica generated from the hydrolyzation of tetraethyl orthosilicate (TEOS). Amino silane (SG-Si900) was added to this solution for surface modification of silica coated magnetic particles. Finally, D-penicillamine (D-PA)-antimetadherin (anti-MTDH) was covalently linked to the amine group using glutaraldehyde as cross-linker. Magnetic nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and atomic force microscopy (AFM). AFM results showed that particles are nearly monodisperse, and the average size of particles was 40 to 50 nm. An amino acid derivative D-PA was conjugated anti-MTDH, which results the increase of uptaking potential of a conjugated agent, labelled fluorescein isothiocyanate (FITC) and then conjugated to the magnetic nanoparticles. In vitro evaluation of the conjugated D-PA-anti-MTDH-FITC to magnetic nanoparticle was studied on MCF-7 breast cancer cell lines. Fluorescence microscopy images of cells after incubation of the sample were obtained to monitor the interaction of the sample with the cancerous cells. Incorporation on cells of FITC labeled and magnetic nanoparticles conjugated D-PA-anti-MTDH was found higher than FITC labeled D-PA-anti-MTDH. The results show that magnetic properties and application of magnetic field increased incorporation rates. The obtained D-PA-anti-MTDH-magnetic nanoparticles-FITC complex has been used for in vitro imaging of breast cancer cells. FITC labeled and magnetic nanoparticles conjugated D-PA-anti-MTDH may be useful as a new class of scintigraphic agents. Results of this study are sufficiently encouraging to bring about further evaluation of this and related compounds for ultraviolet magnetic resonance (UV-MR) dual imaging. (author)

  13. Intracellular labeling and quantification process by magnetic resonance imaging using iron oxide magnetic nanoparticles in rat C6 glioma cell line; Marcacao intracelular e processo de quantificacao por imagem por ressonancia magnetica utilizando nanoparticulas magneticas de oxido de ferro em celulas da linhagem C6 de glioma de rato

    Energy Technology Data Exchange (ETDEWEB)

    Mamani, Javier Bustamante; Pavon, Lorena Favaro; Sibov, Tatiana Tais; Rossan, Fabiana; Silveira, Paulo Henrique; Cardenas, Walter Humberto; Gamarra, Lionel Fernel, E-mail: javierbm@einstein.br [Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Miyaki, Liza Aya Mabuchi [Faculdade de Enfermagem, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Amaro Junior, Edson [Departamento de Diagnostico por Imagem e Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil)

    2012-04-15

    Objective: To assess intracellular labeling and quantification by magnetic resonance imaging using iron oxide magnetic nanoparticles coated with biocompatible materials in rat C6 glioma cells in vitro. These methods will provide direction for future trials of tumor induction in vivo as well as possible magnetic hyperthermia applications. Methods: Aminosilane, dextran, polyvinyl alcohol, and starch-coated magnetic nanoparticles were used in the qualitative assessment of C6 cell labeling via light microscopy. The influence of the transfection agent poly-L-lysine on cellular uptake was examined. The quantification process was performed by relaxometry analysis in T{sub 1} and T{sub 2} weighted phantom images. Results: Light microscopy revealed that the aminosilane-coated magnetic nanoparticles alone or complexed with poly-L-lysine showed higher cellular uptake than did the uncoated magnetic particles. The relaxactivities of the aminosilane-coated magnetic nanoparticles with a hydrodynamic diameter of 50nm to a 3-T field were r{sub 1}=(6.1 +- 0.3) x10{sup -5} ms{sup -1}mL/{mu}g, r{sub 2}=(5.3 +- 0.1) x 10{sup -4} ms{sup -1}mL/{mu}g, with a ratio of r{sub 2} / r{sub 1}{approx_equal} 9. The iron uptake in the cells was calculated by analyzing the relaxation rates (R{sub 1}and R{sub 2}) using a mathematical relationship. Conclusions: C6 glioma cells have a high uptake efficiency for aminosilane-coated magnetic nanoparticles complexed with the transfection agent poly-L-lysine. The large ratio r{sub 2} / r{sub 1}{approx_equal} 9 indicates that these magnetic nanoparticles are ideal for quantification by magnetic resonance imaging with T{sub 2}-weighted imaging techniques. (author)

  14. {beta} -carotene effect the induction of the sister chromatid exchanges (ICH) by gamma radiation in mouse radiosensibilized osseous marrow cells In vivo; Efecto del {beta}- caroteno la induccion de intercambios en las cromatidas hermanas (ICH) por radiacion gamma en celulas radiosensibilizadas de la medula osea de raton In vivo

    Energy Technology Data Exchange (ETDEWEB)

    Morales R, P.; Cruz V, V.L. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico). Dept. de Biologia

    1997-07-01

    The effect of {beta}- carotene over the ICH radioinduction in radiosensibilized with BrdU osseous marrow cells of mouse was determined In vivo. The treatment with 50 {mu}g {beta} carotene per se induces a significant increment in the ICH frequency and the pre or post-treatment with the same dose causes an additive effect in the ICH frequency produced by 0.62 Gy of gamma radiation. This implies that {beta}- carotene does not have radioprotective activity, under conditions which was developed this experiment. (Author)

  15. Reduction of greenhouse gases emissions listed in the Kyoto Protocol by the utilization of landfill gas using solid oxide fuel cells; Reducao das emissoes de gases de efeito estufa listados no protocolo de Quioto pelo aproveitamento do gas gerado em aterros sanitarios utilizando celulas a combustivel de oxido solido. Estudo de caso do aterro municipal de Santo Andre, SP, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Paris, Alexandre Gellert

    2007-07-01

    In the last few years, the Kyoto Protocol had been a subject very debated, at first, in a restricted niche, manly academics and professionals related to the area of climate changes. On 16th February 2005 the Kyoto Protocol entered into force and with this a lot of publicity all over the world, so today is common to hear about it at the mass communications media. The extension of the subject is broad, this work discuss the utilization of one the Kyoto's flexibility mechanisms, to contribute to financing the use of the landfill gas in the solid oxide fuel cells. Among the three mechanisms presented in the Kyoto Protocol, the clean development mechanism (CDM) in article 12, is the only one that can be implemented by non-Annex I countries, the case of Brazil. In other hand, the issue of solid waste in Brazil is critical. Even being illegal, most of the solid waste goes to uncontrolled areas in open air places 'lixoes', causing degradation of the environment and the communities around this areas, and also emission of green house gases (GHG), deregulating the global climate system. Decontaminate this areas and the construction of landfills to replace than, considering the landfill as a bioreactor, and the utilization of the biogas to generate power can improve nowadays picture that we are facing. The utilization of an innovative alternative technology as the solid oxide fuel cell (SOFC) instead the conventional technologies will be more efficient and environmentally better. Among other barriers the cost is pointed as the biggest. In this context, the SOFC is the most expensive fuel cell, so the utilization of CDM can contribute to finance the application of this technology. Scenarios were made of 250 kW, 500 kW, 1,000 kW, 5,000 kW and 10,000 kW of installed power using biogas from the Municipal Landfill of Santo Andre. The calculations of the emission factor were done ex ante and ex post according to ACM0002. Comparing the costs of the installed power studied and the calculation of the emission reduction, a potential income, the costs are superior, however, other incomes from the selling of energy and the disposal of solid waste most be taken into account in the process of decision of this type of projects. (author)

  16. Induced thermal ablation with a radiofrequency field in breast cancer cells using gold nanoparticles conjugated to the peptide cycle[RGDfK(C)]; Termoablacion inducida con un campo de radiofrecuencia en celulas de cancer de mama utilizando nanoparticulas de oro conjugadas al peptido ciclo[RGDfK(C)

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez H, L.

    2014-07-01

    The conjugation of peptides to gold nanoparticles (AuNP) produces biocompatible and stable multimeric systems with target-specific molecular recognition. Peptides based on the cyclic Arg-Gly-Asp (RGD) sequence have been reported as high-affinity agents for the α(v)β(3) and α(v)β(v) integrin s over expressed in breast cancer cells. AuNP have also been proposed as localized heat sources for cancer treatment using laser irradiation or radiofrequency (RF). The objective of this research was to evaluate the thermo ablative effect of the AuNP-c [RGDfK(C)] system on MCF7 breast cancer cell viability after exposure to a radiofrequency field and to compare it with that produced by the laser irradiation. The effect of the 13.56 MHz RF (using a power from 0 to 200 W at intervals of 50 W) over the temperature increase in AuNP-colloidal system of 5 and 20 nm at two different concentrations was evaluated. The absorption cross sections (C{sub abs}) of the AuNP-c [RGDfK(C)] nano system when it interacts with low frequency electromagnetic waves (13.56 MHz, λ = 22 m) and optical frequency waves (laser at λ = 532 nm) was analyzed based on the Mi e theory. The effect on the MCF7 cell viability was assessed using two thermal conversion sources (Laser and RF) on AuNP-c [RGDfK(C)] located inside the cytoplasm of the cells. MCF7 cells were treated with AuNP-c [RGDfK(C)] or water after exposure to the RF field (200 W, 100 V/cm) or laser irradiation (Irradiance 0.65 W/cm{sup 2}). In both cases (RF and laser) the presence of nanoparticles internalized inside the cells caused a significant increase in the temperature of the medium (RF: ΔT = 29.9 ± 1.7 grades C for AuNP compared toΔT = 13.0 ± 1.4 grades C for water; laser: ΔT = 13.5 ± 0.7 grades C for AuNP compared to 3.3 ± 0.5 grades C for water). Although RF induced a higher increase in the temperature of the medium with nanoparticles, the largest effect on the cell viability was produced by laser when nanoparticles were located inside the cells (8.7 ± 0.7 % for laser compared to 19.4 ± 0.9 % for RF). The differences obtained in C{sub abs} values (laser: 3.7x10{sup -16} m{sup 2}; RF: 7.9x10{sup -23} m{sup 2}) and the observed effect on MCF7 cell viability support two mechanisms proposed -optical frequency wave energy absorption by AuNP- when laser is used as a thermal conversion source, and -energy attenuation of the low frequency electromagnetic wave propagating through the AuNP-colloidal system- when RF field is applied. The AuNP-c[RGDfK(C)] nano system shows suitable properties to improve hyperthermia treatments under laser irradiation due to a larger heat release inside cells. (Author)

  17. The importance of investigation of anatomic variations in the ethmoid cells by computerized tomography in the planning of endoscopic nasal surgery; A importancia da investigacao de variacoes anatomicas das celulas etmoidais atraves da tomografia computadorizada no planejamento da cirurgia endoscopica nasal

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Cristiane Regina; Wafae, Nader; Nascimento, Sergio Ricardo Rios; Camelo, Julio Cesar; Maciel, Luana Teixeira; Consolari, Mario Agostinho Severo [Centro Universitario Sao Camilo, Sao Paulo, SP (Brazil)], e-mail: crisruiz@saocamilo-sp.br, e-mail: riosnascimento@uol.com.br

    2009-01-15

    The ethmoidal cells comprise many cavities that show many anatomical variations. Some of these variations deserve special attention when associated with sinusitis and the need of surgery. Computed tomography, considered a gold standard on the pathological investigation of the nasal cavity and the anatomic description of paranasal sinus, offers information about these cells, essential to minimize the surgical risks. The authors present a bibliographic revision of the importance of computed tomography on the investigation of anatomic variations of ethmoid cells. Not recurrent cells in all individuals, like Haller's cells, Onodi's cells and pneumatization of agger nasi, will do the endoscopic approach with precaution. The ethmoidal roof evaluation will result in more safety on the upper limits of the nasal cavity. The size and pneumatization level of ethmoidal bulla, ethmoidal crest, and middle nasal concha are important on the evaluation of the endoscopic accesses and the gravity of the stroked pathology and even diagnose your origin. (author)

  18. Electrolytic hydrogen production at off-peak consumption and his utilization as energy vector at peak consumption through use of fuel cells; Producao de hidrogenio eletrolitico nos horarios fora de ponta e sua utilizacao como vetor energetico nos horarios de ponta atraves do uso de celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Gambetta, Francielle [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mail: fgambetta@fem.unicamp.br; Silva, Ennio Peres da [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Fisica. Lab. de Hidrogenio

    2008-07-01

    Due the fact that consumers have different demand, depending on the pace of economic activities and their daily habits of consumption, there is a different electrical demand throughout the day. Demand, in general, is minimal during the morning and it grows with the move for hours to reach peak consumption between 18:00 and 22:00, then turning to fall. It is old the idea of storing electricity produced in off-peak for its consumption in peak hours. To store large amounts of electrical power is required its conversion into some other form of energy, since it is impossible to store electrical energy as such in large quantities. One way of storing electricity is in the form of hydrogen produced by electrolysis of water which then can be stored, purified and converted into electricity through fuel cells. When there is an increase in demand for electricity, there is a need to expand the supply of energy, which means investments in generation, transmission and distribution. This work was performed a preliminary analysis of the production of electrolytic hydrogen in hours of low demand and its use in the generation of electricity in peak hours, making use of the fuel cells, so that to a certain limit value of increased electricity demand, there is no need for expansion of supply of Foz do Iguacu/PR. Moreover, at this work, the ability to harness the heat generated in fuel cells for heating water in homes was considered. (author)

  19. [In vitro effect of the S3Pvac vaccine against cysticercosis in human mononucleate cells].

    Science.gov (United States)

    Díaz-Orea, María Alicia; Mijares, José Miguel; Arcega, Raúl; Gómez-Conde, Eduardo; Castellanos-Sánchez, Víctor Omar; Briones-Rojas, Rosendo; Flores-Alonso, Juan Carlos; Marín-Briones, Miguel Ángel; Santos-López, Gerardo

    2013-05-01

    Introduccion. La neurocisticercosis (NCC) es una infeccion parasitaria generada por el establecimiento de cisticercos de Taenia solium en el sistema nervioso central. La fase larvaria del parasito tambien afecta al cerdo, que es el huesped intermediario indispensable para la transmision. Por tal motivo, muchos investigadores se han enfocado en identificar antigenos protectores para prevenir la cisticercosis porcina e interrumpir la transmision. Entre ellos figuran los antigenos de la vacuna S3Pvac, constituida por tres peptidos protectores: KETc1, KETc12 y GK1. Objetivo. Evaluar el efecto de los peptidos vacunales KETc1, KETc12 y GK1 en celulas mononucleares de pacientes con NCC e individuos sanos. Sujetos y metodos. Estudio comparativo, prospectivo y transversal. Se analizo la proliferacion y el perfil de citocinas inducidos por los tres peptidos en celulas mononucleares de tres pacientes con NCC activa, 16 pacientes con NCC calcificada y 16 sujetos sanos. Resultados. KETc1 induce bajos niveles de proliferacion en las celulas de los pacientes con NCC activa y controlada, tanto en linfocitos como en monocitos. KETc12 y GK-1 inducen niveles positivos de proliferacion de monocitos en sujetos sanos. Conclusiones. El peptido KETc1 podria usarse como coadyuvante en el tratamiento de los pacientes con NCC activa, ya que indujo una respuesta Th2; y el peptido GK1, como estimulador del monocito/macrofago en inmunizaciones con otras proteinas.

  20. Hacia una nueva concepción de la paternidad y la maternidad

    Directory of Open Access Journals (Sweden)

    Gil Calvo, Enrique

    2004-06-01

    Full Text Available En este texto me propongo discutir algunas de las líneas que parecen dibujarse en torno a una futura convergencia progenitora entre paternidad y maternidad. Para ello esbozaré en una primera sección los argumentos básicos que permiten sugerir esa futura convergencia hipotética. En la siguiente sección analizaré los riesgos institucionales que hoy amenazan a la responsabilidad progenitora, entre los que destacan en especial la prolongada obstrucción de la emancipación juvenil y el creciente distanciamiento intergeneracional. Y en la tercera y última abordaré el riesgo de fracaso progenitor, apuntando el dilema trágico de la responsabilidad educativa.…

  1. Sangue periférico como fonte de células para terapia celular Peripheral blood as a source of stem cells

    OpenAIRE

    Alfredo Mendrone Junior

    2009-01-01

    O sangue periférico tem sido utilizado como fonte de células progenitoras hematopoéticas para o transplante de medula óssea, única aplicação clínica bem estabelecida até o momento para as células-tronco. Mais recentemente, além das células progenitoras hematopoéticas, estudos têm identificado também no sangue periférico a presença de células-tronco mesenquimais. Estas células apresentam as mesmas características e marcadores de superfície que as células-tronco mesenquimais da medula óssea e s...

  2. Solución a un preoblema de ecuaciones diferenciales parciales por el método de fourier

    OpenAIRE

    Gómez G., Jaime

    2012-01-01

    Una ecuación que contiene una o más derivadas parciales de una función de dos o más variables independientes se llama ecuación diferencial parcial. Se llama orden de la ecuación al orden de la derivada superior

  3. Element abundances and distributions in the crab nebula

    Directory of Open Access Journals (Sweden)

    G. M. MacAlpine

    2001-01-01

    Full Text Available La Nebulosa del Cangrejo proporciona oportunidades unicas para investigar diversos aspectos de la nucleos ntesis y del enriquecimiento de elementos relativos a la estrella progenitora y a la estrella de neutrones joven. Se pueden combinar datos espectrosc opicos e im agenes para conocer la distribuci on de abundancias. Nuestros conocimientos sobre esta remanente de supernova han aumentado de manera considerable en los ultimos a~nos.

  4. OPEN SLIT ECHELLE SPECTROSCOPY OF PLANETARY NEBULA M 1-9

    Directory of Open Access Journals (Sweden)

    J. Bohigas

    2012-01-01

    uniforme (Cloudy, versi on 10.00 reproduce la mayor parte del espectro, aunque la intensidad de [O III] 4363 A es mucho mayor que la observada. En este modelo, las abundancias nebulares son m s bajas que las obtenidas con t cnicas usuales y la temperatura y luminosidad estelar son 84900 K y 1025 L? , lo que significa que la progenitora probablemente fue una estrella de =1 M? en secuencia principal.

  5. Close binary white dwarfs and supernovae IA

    Directory of Open Access Journals (Sweden)

    R. Napiwotzki

    2004-01-01

    Full Text Available Informamos sobre el estado actual de los \\surveys" de velocidades radiales para binarias de enanas blancas (degeneradas dobles - DDs incluyendo SPY (Exploraci on ESO de progenitoras de supernovas Ia que recien- temente se llevaron a cabo en el VLT. Una amplia muestra de DDs nos permitir a poner fuertes restricciones sobre las fases evolutivas de los sistemas progenitores de binarias cercanas y tambi en llevar a cabo pruebas observacionales del escenario DD para supernovas de tipo Ia.

  6. Relaciones de parentesco en las nuevas familias: disociaci??n entre maternidad/paternidad biol??gica, gen??tica y social

    OpenAIRE

    Grau Rubio, Claudia; Fern??ndez Hawrylak, Mar??a

    2015-01-01

    Se describen y analizan las relaciones de parentesco en las familias monoparentales, homoparentales, tard??as o de edad avanzada, con embarazos m??ltiples, reconstituidas, adoptivas y las que recurren a las t??cnicas de reproducci??n asistida. En estas familias se puede producir una disociaci??n entre relaciones conyugales y relaciones filiales; entre sexualidad y reproducci??n; entre pareja conyugal, pareja parental y pareja progenitora; y la creaci??n de lazos de filiaci??n independientemen...

  7. ENSO impacts on the South American rainfall during 1980s: Hadley and Walker circulation

    Energy Technology Data Exchange (ETDEWEB)

    De Souza, E.B.; Ambrizzi, T. [Departamento de Ciencias Atmosfericas, Instituto Astronomico y Geofisico, Sao Paulo, SP (Brazil)

    2002-04-01

    The changes in the Hadley and Walter cells and their respective impacts on the South American rainfall during the ENSO episodes observed in the decade of 80, were investigated through cross-sections analyses of the atmospheric circulation in altitude, averaged in the zonal and meridional planes. Such large-scale cells almost inverted their climatological circulation pattern, during El Nino events (1982-83 and 1986-87). In these years, manifestation of the anomalous descending branch of the Hadley and Walker cells affects most of the north-northeast of South America, which inhibited the convective activity associated to the Inter Tropical Convergence Zone (ITCZ) and caused drought conditions in the rainy seasons of the Guyana, Surinam, French Guyana, center-east of the Amazon and most of the Northeast Brazil. On the other hand, conditions of excess of precipitation observed in the south-southeast of South America, were favored by the anomalous ascending branch of the Hadley cell. During La Nina events (1984-85 and 1988-89), it was observed an intensification of the ascending and descending branches associated to the Walker and Hadley cells. The anomalous large-scale ascending movement associated to these cells, was extended to the Northeast of Brazil and equatorial South Atlantic, favoring ITCZ to become more active than the normal, which resulted in an above normal rainy season in these areas. An intense subsidence was noticed in the mid latitudes of South America, which inhibited the large-scale convection in the region, explaining the deficient rainy season observed in most of the south-southeast of South America. [Spanish] Los cambios en las celulas de Hadley y Walker y sus respectivos impactos en Suramerica, en las lluvias, durante los episodios en ENOS, observados en la decada de los 80, son investigados a traves de analisis de reacciones cruzadas de la circulacion atmosferica en altitudes promediadas en planos zonal y meridional. Tales celulas de gran escala

  8. Preparation and characterization of PtRu/C, PtBi/C, PtRuBi/C electrocatalysts for direct electro-oxidation of ethanol in PEM fuels cells using the method of reduction by sodium borohydride; Preparacao e caracterizacao de eletrocatalisadores PtRu/C, PtBi/C, PtRuBi/C para eletro-oxidacao direta de etanol em celulas a combustivel tipo PEM utilizando a metodologia da reducao via borohidreto de sodio

    Energy Technology Data Exchange (ETDEWEB)

    Brandalise, Michele

    2010-07-01

    Pt/C, PtBi/C, PtRu/C and PtRuBi/C electrocatalysts were prepared by a borohydride reduction methodology and tested for ethanol oxidation. This methodology consists in mix a solution with sodium hydroxide and sodium borohydride to a mixture containing water/isopropyl alcohol, metallic precursors and the Vulcan XC 72 carbon support. It was studied the addition method of borohydride (drop by drop addition or rapid addition). The obtained electrocatalysts were characterized by energy dispersive X ray spectroscopy (EDX), thermogravimetric analysis (TGA), X ray diffraction (XRD), transmission electron microscope (TEM) and cyclic voltammetry. The ethanol electro-oxidation was studied by cyclic voltammetry and chronoamperometry using the thin porous coating technique. The electrocatalysts were tested in real conditions of operation by unit cell tests. The stability of PtRuBi/C electrocatalysts was evaluated by cyclic voltammetry, chronoamperometry using the ultra-thin porous coating technique and ring-disk electrode. The PtRuBi/C electro catalyst apparently presented a good performance for ethanol electro-oxidation but experimental evidences showed accentuated bismuth dissolution. (author)

  9. Performance of Nafion-TiO{sub 2} hybrid membranes and PtSn/C electrocatalysts in PEM type fuel cells fed with ethanol and H{sub 2}/CO at high temperature; Desempenho de membranas hibridas Nafion-TiO{sub 2} e eletrocatisadores de PtSn/C em celulas a combustivel do tipo PEM alimentadas com etanol e com H{sub 2}/CO em alta temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Isidoro, Roberta Alvarenga

    2010-07-01

    In this work, Nafion-TiO{sub 2} hybrid electrolytes and PtSn/C electrocatalysts were synthesized for the application in direct ethanol fuel cell operating at high temperature (130 degree C). For this purpose, TiO{sub 2} particles were incorporated in commercial Nafion membranes by an 'in situ' sol gel route. The resulting materials were characterized by gravimetric analysis, water uptake, DSC, XRD and EDX. Electrocatalysts based on carbon dispersed platinum-tin (PtSn/C), with different composition, were produced by alcohol-reduction method and were employed as anodic electrode. The electrocatalysts were characterized by XRD, EDX, XPS and transmission electronic spectroscopy. The electrochemical characterization was conducted by cyclic voltametry, carbon monoxide linear anodic voltammetry (CO stripping), and chronoamperometry. Membrane-electrodes assembly (MEAs) were formed with PtSn/C anodes, Pt/C cathodes and Nafion-TiO{sub 2} hybrids. The performance of these MEA was evaluated in single-cell fed with H2/CO mixture or ethanol solution at the anode and oxygen at the cathode in the temperature range of 80-130 degree C. The analysis showed that the hybrid membranes improved the DEFC performance due to crossover suppression and that PtSn/C 70:30 electrocatalysts, prepared by an alcohol reduction process, showed better performance in ethanol oxidation. (author)

  10. Cytogenetic and dosimetric effects of {sup 131}I in lymphocyte of patients with differentiated thyroid cancer with and without r-hTSH stimulation. Study in thyroid tumor cells (WRO) treated with {sup 131}I and {sup 60}Co in vitro; Efeitos citogenetico e dosimetrico do {sup 131}I em pacientes com cancer diferenciado da tireoide com e sem estimulacao com r-hTSH. Estudo em celulas tumorais tireoidianas (WRO) tratadas com {sup 131}I e {sup 60}Co in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Valgode, Flavia Gomes Silva

    2015-11-01

    Differentiated thyroid cancer (DTC) represents about 90% of thyroid malignancies with increasing incidence in the recent decades. Treatment modalities include thyroidectomy, {sup 131}I therapy (with or without r-hTSH), radio and chemotherapy. Little is known about the effects of these treatments at the cellular level. This work was proposed in order to assess to what extent radioiodine therapy can cause damage in peripheral lymphocytes of patients with DTC, preceded or not by r-hTSH, taking into account acute, slow and dosimetric effects of {sup 131}I (in vivo study). An in vitro study was also carried out on thyroid tumor target cells (WRO) by cytotoxicity and genotoxicity analysis and radioiodine uptake. For this, blood samples from patients divided into two groups (group A, r-hTSH + {sup 131}I and group B,{sup 131}I only) were collected before, 24 hours, 1 week, 1 month and 1 year after {sup 131}I administration for aberration chromosome analysis (CA). A dose-response curve for {sup 131}I in vitro was developed for estimating the absorbed dose in patients, comparing the dicentric frequencies obtained in vitro with in vivo data by Monte Carlo program. Radioiodine therapy induced an increase in the number of CA in lymphocytes of patients peaking 24 hours after treatment, with gradual decline over time and with more chromosomal damage in group B than in group A, reaching baseline levels one year after radioiodine administration. The frequency of dicentric found inpatient lymphocytes, 24h after treatment, was equivalent to that induced in vitro (0.354 ± 0.153 MBq / mL for group A and 0.309 ± 0.154 MBq / mL for group B), which corresponds to absorbed doses of 0.8 ± 0.3 Gy and 0.7 ± 0.3 Gy for groups A and B, respectively, with no significant difference between the groups. WRO cells showed a cell cycle relatively slow: 96,3h with an unstable karyotype. The genotoxic test showed a relatively high radioresistance (0.07 to 3.70 MBq/mL), with no statistical significance, with or without r-hTSH. However, the cytotoxic assay, showed a tendency to decrease at higher concentrations of 1.85 (p <0.05) and 3.70 MBq/ml (p <0.01) only in the presence of r-hTSH, coincident with the highest level of uptake. WRO cells were also relatively radioresistant to external irradiation of {sup 60}Co in the range of 0.2-8.3 Gy, with a gradual decrease in function of time for higher doses (10,20 and 40Gy).The data obtained showed little cytogenetic damage in patients upon therapeutic exposure, suggesting a safe and effective treatment for both groups of patients. Patients in group A, however, had a better quality of life by using r-hTSH. In vitro studies with internal ({sup 131}I) and external ({sup 60}Co) irradiation, with or without r-hTSH, point to the need for an alternative therapeutic strategy to overcome the loss of ability of thyroid cells (WRO) to concentrate radioiodine, which is responsible for the failure of radioiodine therapy in patients with DTC. (author)

  11. Mineral and/or milk supplementation of fruit beverages helps in the prevention of H2O2-induced oxidative stress in Caco-2 cells La adición de minerales y/o leche a bebidas a base de zumo de frutas ayuda en la prevención del estrés oxidativo inducido por H2O2 en celulas Caco-2

    Directory of Open Access Journals (Sweden)

    A. Cilla

    2011-06-01

    Full Text Available Introduction: Fruit beverages are commonly supplemented with milk, vitamins and/or minerals in order to improve their healthy effects by providing some bioactive components that can act additively or synergistically against oxidative stress. Aims: To test whether iron, zinc, and milk added to fruit beverages do not affect the cytoprotective effect against oxidative damage to Caco-2 cells through GSH-related enzymes induction and cell cycle progression preservation, in comparison with non-supplemented fruit beverage. Methods: Caco-2 cells were incubated 24 h with the bioaccessible fraction (BF of eight fruit beverages with/without iron and/or zinc, and/or milk, and then challenged with H2O2 (5 mmol L-1 -2 h. Mitochondrial enzyme activities (MTT test, GSH-Rd and GSH-Px enzyme activities, cell cycle progression and caspase-3 activity were measured. Results and discussion: Fruit beverages prevented the deleterious effect of H2O2 on cell viability, with almost all samples reaching control basal levels. Only independent iron or zinc supplementation with/without milk exerted positive effects upon GSH-Rd activity. Both minerals with milk, afforded improved preservation of GSH-Px activity. All samples prevented the decrease in the G1 phase of cell cycle induced by H2O2, except iron supplemented samples with/without milk, but none of them avoided the increase in sub-G1 phase. However, this fact was not associated to caspase-3 activity, with a probable positive effect of zinc upon this parameter. Conclusion: Mineral and/or milk supplementation of fruit beverages helps in the prevention of oxidative stress in Caco-2 cells based on cell viability maintenance, GSH-related enzymes activation, cell cycle distribution preservation and inhibition of caspase-3 activation.Introducción: En la actualidad las bebidas a base de zumo de frutas llevan adicionadas leche, vitaminas y/o minerales con objeto de mejorar sus efectos beneficiosos para la salud mediante el aporte de numerosos compuestos bioactivos que pueden actuar de forma aditiva o sinérgica frente al estrés oxidativo. Objetivos: Evaluar si la adición de hierro, cinc y leche a las bebidas a base de zumo de frutas no afecta al efecto cito-protector frente al daño oxidativo en células Caco-2 a través de la inducción de enzimas del ciclo del GSH y la preservación de la progresión del ciclo celular, en comparación con la bebida a base de zumo de frutas no suplementada. Métodos: Las células Caco-2 se incubaron 24 h con las fracciones bioaccesibles (FB de ocho bebidas a base de zumo de frutas con/sin hierro y/o cinc y/o leche, y se sometieron a estrés oxidativo con H2O2 (5 mmol L-1-2 h. Se determinó la actividad enzimática mitocondrial (test MTT, la actividad de las enzimas GSH-Rd y GSH-Px, la progresión del ciclo celular y la actividad de la enzima caspasa-3. Resultados y discusión: Las bebidas a base de zumo de frutas previnieron del efecto perjudicial del H2O2 sobre la viabilidad celular, con casi todas las muestras alcanzando los niveles basales del control. Sólo la adición independiente de hierro o cinc con/sin leche ejerció efectos positivos sobre la actividad de la enzima GSH-Rd. Por otra parte, ambos minerales con leche proporcionaron una mejor preservación en la actividad de la enzima GSH-Px. Todas las muestras previnieron el descenso en la fase G1 del ciclo celular inducido por el H2O2, excepto la muestra adicionada de hierro, pero ninguna de ellas evitó el incremento en la fase subG1 del ciclo celular. Sin embargo, este hecho no estuvo asociado con la actividad de la enzima caspasa-3, con un probable efecto positivo del cinc sobre este parámetro. Conclusión: La adición de minerales y/o leche a las bebidas a base de zumo de frutas ayuda en la prevención de estrés oxidativo en células Caco-2 mediante el mantenimiento de la viabilidad celular, activación de enzimas del ciclo del GSH, preservación de la progresión del ciclo celular e inhibición en la activación de la enzima caspasa-3.

  12. Preparation of PtSn/C, PtRu/C, PtRh/C, PtRuRh/C and PtSnRh/C electrocatalysts using an alcohol-reduction process for methanol and ethanol oxidation; Preparacao e caracterizacao de eletrocatalisadores PtRu, PtSn, PtRh, PtRuRh e PtSnRh para oxidacao direta de alcoois em celulas a combustivel tipo PEM utilizando a metodologia da reducao por alcool

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Ricardo Rodrigues

    2009-07-01

    In this work, Pt/C, PtRh (90:10), PtRh/C (50:50), PtSn/C (50:50), PtRu (50:50)/C, PtRuRh/C (50:40:10) and PtSnRh/C (50:40:10) were prepared by an alcohol-reduction process with metal loading of 20 wt.% using H{sub 2}PtCl{sub 6}.6H{sub 2}O (Aldrich), SnCl{sub 2}.2H{sub 2}O (Aldrich),and RhCl{sub 2}.XH{sub 2}O (Aldrich) as metals sources and Vulcan XC72 as support. The electrocatalysts were characterized by EDX, XRD and cyclic voltammetry (CV). The electro-oxidation of ethanol was studied by CV, chronoamperomety at room temperature in acid medium and tests at 100 deg C on a single cell of a direct methanol or ethanol fuel cell. The EDX analysis showed that the metal atomic ratios of the obtained electrocatalysts were similar to the nominal atomic ratios used in the preparation. The diffractograms of electrocatalysts prepared showed four peaks at approximately 2{theta} =40 deg, 47 deg, 67 deg and 82 deg, which are associated with the (111), (200), (220) and (311) planes, respectively, of a face cubic-centered (fcc) structure characteristic of platinum and platinum alloys. The average crystallite sizes using the Scherrer equation and the calculated values were in the range of 2-3 nm. For Pt Sn/C and PtSnRh/C two additional peaks were observed at 2 = 34 deg and 52 deg that were identified as a SnO{sub 2} phase. Pt Sn/C (50:50) and PtSnRh/C (50:40:10) electro catalyst showed the best performance for ethanol oxidation at room temperature. For methanol oxidation at room temperature Pt Ru/C, Pt Sn/C and PtRuRh/C electrocatalysts showed the best performance. Tests at 100 deg C on a single cell of a direct ethanol fuel cell PtSnRh/C showed the best performance, for methanol oxidation PtRuRh/C showed the best performance. (author)

  13. Synthesis and characterization of La{sub 1-x}Sr{sub x}MnO{sub 3} (x=0,1) for cathode application in solid oxide fuel cells (SOFC); Sintese e caracterizacao de La{sub 1-x}Sr{sub x}MnO{sub 3} (x=0,1) visando sua aplicacao como catodo em celulas a combustivel de oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Tarrago, D.P.; Sousa, V.C., E-mail: dptarrago@gmail.co [Universidade Federal do Rio Grande do Sul (LABIOMAT/PPGEM/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos graduacao em Engenharia de Minas. Lab. de Biomateriais; Malfatti, C.F. [Universidade Federal do Rio Grande do Sul (LAPEC/PPGEM/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos graduacao em Engenharia de Minas. Lab. de Pesquisa em Corrosao

    2010-07-01

    Perovskite powders, with composition La{sub 1-x}Sr{sub x}MnO{sub 3} (x=0,1) were obtained via combustion synthesis using sucrose as fuel. In the X-ray diffraction patterns it was observed that in order to obtain a single phase and well crystallized material a calcination in 750 deg C for 3 hours was necessary. BET analysis detected a specific surface area of 45m{sup 2}/g, considerably higher than when obtained with other fuels. SEM micrographs revealed a spongy aspect with a connected porosity in the agglomerates and though TEM micrographs the presence of pores in the particles was verified. The powder compacted with 125MPa and sintered at 1050 deg C for two hours presented a 31% open porosity and the SEM micrographs showed a fine interconnected porosity. (author)

  14. Evaluation of the radiosensitizing to treatment with {sup 153}Sm-EDTMP, of haematopoietic cells of the bone marrow by means of bromodeoxyuridine incorporation into DNA, in a murine model; Evaluacion de la radiosensibilizacion al tratamiento con {sup 153}Sm-EDTMP, de las celulas hemotopoyeticas de la medula osea mediante la incorporacion de bromodesoxiuridina (BrdU) en el ADN, en un modelo murino

    Energy Technology Data Exchange (ETDEWEB)

    Morales A, E.

    2008-07-01

    Bromodeoxyuridine (BrdU) has been shown to have a radiosensitizing effect, and its incorporation into DNA prior to administration of a bone-seeking radiopharmaceutical could increase the efficiency of bone marrow ablation, and even increase the specificity of radiation exposure for therapeutic purposes. The aim of the present study was to determine the effect of BrdU incorporation into DNA on the genotoxic and cytotoxic effects of samarium-153 ethylenediaminetetra-methylene phosphonate ({sup 153}Sm-EDTMP) in murine bone marrow cells. BALB/c male mice (N = 5 in each experiment) were treated with one of the following substances: a) BrdU (0.25 mg/g) b) {sup 153}-EDTMP (11.5 +- 3 MBq) c) BrdU (0.25 mg/g) plus {sup 153}Sm-EDTMP (11.5 +- MBq), there was also an untreated control. Cytotoxicity and genotoxicity were established by time-response and absorbed dose-response curves of polychromatic erythrocyte (PCE) and micro nucleated polychromatic erythrocyte (MN-PCE) frequencies, respectively, in murine peripheral blood samples in vivo. The significance of the differences between groups was determined by a variation of Dunett test for multiple groups and different-sized groups of a student test. Beta-absorbed dose fractions obtained from MNCP4B Monte Carlo computer code were used for mice bone marrow dosimetry calculations. At an average radiation absorbed dose of 0.38 Gy, 0.56 Gy and 0.82 Gy at 24, 40 and 72 h respectively, cells from animals treated with {sup 153}Sm-EDTMP showed a clear and significant induction of MN-PCE after 24 h, with the maximum response at 40 h, however, cells from group treated with BrdU plus {sup 153}Sm-EDTMP paradoxically showed MN-PCE frequencies only slightly higher than the control at the same absorbed dose. Treatment with {sup 153}Sm-EDTMP caused a slight reduction in PCE frequency, but exposure to BrdU or BrdU plus {sup 153}Sm-EDTMP induced a substantial and significant reduction in PCE frequency from 32 h to the end of the experiment (72 h). The PCE frequencies in the BrdU pretreated and irradiated group were consistently lower than in the BrdU control group, and the difference was significant at the final scored times in the experiment. These effects could be explained by lethal lesions of the accumulation of sublethal damage induced by the irradiation of BrdU-substituted DNA, where this lesion is not easily repaired and subsequently does not permit cell division or micronucleus formation. This research shows the increasing of cytotoxicity when BrdU was administered before the {sup 153}Sm-EDTMP treatment. Further studies are required in order to explore the utility of this strategy for bone marrow ablation or therapy in humans. (Author)

  15. Central effects of fingolimod.

    Science.gov (United States)

    Cruz, Vítor T; Fonseca, Joaquim

    2014-08-01

    Introduccion. El fingolimod, un modulador del receptor de la esfingosina-1-fosfato (S1P) dotado de un mecanismo de accion novedoso, fue el primer tratamiento oral aprobado para la esclerosis multiple remitente recurrente. Su union a los receptores S1P1 de los linfocitos promueve la retencion selectiva de los linfocitos T virgenes y de memoria central en los tejidos linfoides secundarios, lo que impide su salida hacia el sistema nervioso central (SNC). Asimismo, el fingolimod atraviesa con facilidad la barrera hematoencefalica, y diversos estudios le atribuyen un efecto neuroprotector directo en el SNC. Objetivo. Revisar la informacion disponible acerca de los efectos centrales del fingolimod. Desarrollo. El desequilibrio entre los procesos lesivos y reparadores constituye un reflejo de la desmielinizacion cronica, la degeneracion axonal y la gliosis, y parece contribuir a la discapacidad que la esclerosis multiple acarrea. La facilidad con la que el fingolimod atraviesa la barrera hematoencefalica le permite actuar directamente sobre los receptores S1P localizados en las celulas del SNC. Una vez en el interior del SNC, ocupa los receptores S1P de los oligodendrocitos y de sus celulas precursoras, de los astrocitos, los microgliocitos y las neuronas, fomentando la remielinizacion, la neuroproteccion y los procesos endogenos de regeneracion. La eficacia evidenciada en los ensayos clinicos concuerda con un mecanismo de accion que incluiria efectos directos sobre las celulas del SNC. Conclusiones. Los datos disponibles indican que la eficacia del fingolimod en el tratamiento de la esclerosis multiple se debe a su ambivalencia como molecula inmunomoduladora y moduladora directa de los receptores S1P del SNC. Tanto es asi que estudios recientes le atribuyen efectos neuroprotectores en varios modelos que suscitan expectativas en torno a su posible aplicacion terapeutica en la enfermedad de Alzheimer, el paludismo cerebral y el neuroblastoma, asi como en la neuroproteccion

  16. Efeitos de algumas drogas sobre a proliferação de fibroblastos de pterígio primário in vitro

    OpenAIRE

    Juliana Almodin; Flavia Almodin; Edna Almodin; Vânia Cibele Minguetti-Câmara; João Paulo Neves; Ana Karina Teixeira Bezzon; Carla Emília Diniz Maciel Safar; Helaine Belato Bertanha Amadeu

    2013-01-01

    OBJETIVO: Este estudo tem por objetivo observar a inibição da proliferação celular in vitro em pterígios primários utilizando mitomicina C, ciclofosfamida e metotrexato. MÉTODOS: Os pterígios foram retirados de 7 pacientes com idade entre 30 e 60 anos e foram submetidos à cultura de suas células epiteliais. Foi então verificado o efeito de drogas sobre as células: ciclofosfamida, metotrexato e mitomicina. As células foram observadas por 5 dias ao microscópio para avaliar a proliferação celula...

  17. Linfoma primario del sistema nervioso central en una paciente con lupus eritematoso sistémico

    OpenAIRE

    C. N. Pisoni; A. R. Grinberg; J. L. Plana; R. D. Freue; J. A. Manni; Paz, L.

    2003-01-01

    Se presenta una paciente de 36 años con diagnóstico de lupus eritematoso sistémico tratada con prednisona y ciclofosfamida que se internó por cefalea, hemiparesia y hemianestesia braquiocrural derecha de dos semanas de evolución. Se realizó una tomografía computada y una resonancia magnética nuclear de cerebro que mostraron una lesión nodular frontal izquierda. Se efectuó una biopsia a cielo abierto de la lesión cerebral cuyo diagnóstico histopatológico fue linfoma B de celulas grandes, difus...

  18. Procesamiento y unión de la toxina Cry11Bb del Bacillus thuringiensis subsp. Medellín al intestino de larvas de mosquitos

    OpenAIRE

    Fanny Guzmán; Adang, Michael J.; Lina Ruiz; César Segura; Sergio Orduz; Manuel Elkín Patarroyo

    2001-01-01

    La proteína Cry11Bb (94 kDa) es producida por B. thuringiensis subsp. Medellín. El modo de acción de las toxinas Cry incluye el procesamiento proteol��tico y la unión de la toxina a receptores específicos sobre la superficie del intestino de las larvas de los
    insectos susceptibles. Después de unida, la toxina forma poros de baja selectividad sobre la superficie de la membrana apical de las células intestinales, produciendo un desequilibrio osmótico que lleva a la destrucción celula...

  19. Análisis de la variabilidad genética de la anemia de Fanconi en España

    OpenAIRE

    Castellà Castellà, Maria

    2009-01-01

    La anemia de Fanconi (FA) se caracteriza por malformaciones, fallo medular progresivo y predisposición al cáncer. El transplante de médula es actualmente la única opción terapéutica aunque incrementa el riesgo oncológico y son pocos los pacientes con donante compatible lo que ha promovido la investigación en terapia génica y medicina regenerativa basada en reprogramación celular de fibroblastos de pacientes FA a celulas madre pluripotentes (iPS). Son 12 los genes Fanconi hasta ahora descritos...

  20. Propuesta de mediación digital basada en principios conectivistas para tejer prácticas de aprendizaje

    OpenAIRE

    Ramírez Arboleda, José Julián

    2015-01-01

    El Parque Explora es un espacio ciudadano que diseña e implementa escenarios de mediación para desarrollar experiencias educativas en interacción con diversas comunidades -- Las actividades de esta investigación se formularon e implementaron como un escenario de mediación experimental en el contexto educativo del Parque -- Las prácticas de laboratorio en contextos escolares son difíciles de desarrollar por falta de recursos y dificultades humanas -- La masificación del uso de teléfonos celula...

  1. Dianexina na lesão de isquemia reperfusão na musculatura estriada de ratos

    OpenAIRE

    Groth, Anne Karoline

    2012-01-01

    Resumo: Introdução: Lesão de isquemia reperfusão e uma sequela comum e devastadora do retorno do fluxo sanguíneo a um tecido submetido a isquemia. Fosfatidilserina e um fosfolipide que compõe a membrana celular, e que sob condições normais, encontra-se apenas na face citoplasmática da membrana celular. Entretanto, durante a isquemia, a fosfatidilserina é translocada para a face externa da membrana celular, e, no caso das celulas endoteliais, para o interior da microcirculação. A externalizaçã...

  2. Dos problemas relacionados con E.D.P. de evolución no lineales A. Sobre la controlabilidad aproximada de las ecuaciones de Navier-Stokes con control frontera : B. Una nueva demostración de la existencia de solución de leyes de conservación escalares en va

    OpenAIRE

    González Burgos, Manuel

    1993-01-01

    "En esta Memoria, estudiamos cuestiones relacionadas con dos problemas en derivadas parciales de evolución no lineales. En primer lugar, presentaremos resultados relacionados con la controlabilidad aproximada de las ecuaciones incompresibles de Stokes y N

  3. Ecuaciones diferenciales : teoría y práctica

    OpenAIRE

    Perelló, Miguel Ángel

    2002-01-01

    Ecuaciones diferenciales de primer orden. Ecuaciones y sistemas de orden superior. Series y transformada de Laplace. Teoría de la estabilidad. Ecuaciones en derivadas parciales. Introducción al cálculo variacional.

  4. Iterates of differential operators and vector valued functions on non quasi analytic classes

    OpenAIRE

    Juan Huguet, Jordi

    2011-01-01

    En el año 1960 Komatsu introdujo ciertas clases de funciones infinitamente derivables definidas mediante estimaciones del crecimiento de los sucesivos iterados de un operador en derivadas parciales cuando estudiaba propiedades de regularidad de las soluciones de ciertas ecuaciones en derivadas parciales. Esta línea de investigación ha sido muy activa hasta la actualidad a través de los trabajos de muchos autores. Destacamos, entre otros, Bolley, Camus, Kotake, Langenbruch, Métivier, Narasi...

  5. Microquasars and ulxs: fossils of grb sources

    Directory of Open Access Journals (Sweden)

    I. F. Mirabel

    2004-01-01

    Full Text Available Las fuentes de destellos gamma de larga duraci on probablemente resultan del colapso de estrellas masivas en sistemas binarios. Despu es del colapso de la estrella primaria el sistema binario puede permanecer ligado gravitacionalmente dejando como remanente un microcu asar o una fuente Ultraluminosa en rayos X (ULX. En este contexto, los microcu asares y las ULXs son f osiles de las fuentes de destellos gamma y contienen claves sobre la f sica y astrof sica de las fuentes de destellos gamma progenitoras. Aqu muestro que la identi caci on del lugar de nacimiento de los microcu asares acota las propiedades de las estrellas progenitoras de objetos compactos, y que la velocidad con que es disparado el microcu asar puede ser usada para acotar la energ a de la explosi on de las estrellas masivas que son progenitoras de estrellas de neutrones y agujeros negros. Las observaciones muestran que los sistemas binarios con estrellas de neutrones LS 5039, LSI +61 303 y el agujero negro de baja masa en GRO J1655-40 se formaron en explosiones energ eticas, mientras que los agujeros negros de masas mayores (M 10 M en Cygnus X-1 y GRS 1915+105 se formaron por colapso directo en oscuridad completa o en supernovas de baja luminosidad. La asociaci on con c umulos de estrellas masivas de las estrellas de neutrones en LSI +61 303 y de los magnetares SGR 1806-20 and SGR 1900+14, sugiere que estrellas muy masivas (M 50 M pueden bajo ciertas circunstancias, terminar como estrellas de neutrones y no como agujeros negros. Lss fuentes de destellos gamma de larga duraci on contienen los mismos ingredientes b asicos que los microcu asares y las ULXs, objetos compactos con discos de acreci on y chorros relativistas en sistemas binarios, y las analogias fenomenol ogicas encontradas entre los microcu asares y N ucleos Activos de Galaxias podr an ser extendidas a las fuentes de destellos gamma.

  6. CDK5RAP2 function during Zebrafish neurogenesis

    OpenAIRE

    Martins, Tiago Filipe Mendes

    2014-01-01

    Microcefalia de origem primária é uma doença caracterizada por afectar o desenvolvimento cerebral. Cdk5rap2, Aspm e Wdr62 são algumas das proteínas centrossomáis que têm sido descritas como sendo associadas a microcefalias. As proteínas associadas aos centrossomas são evidenciadas como reguladoras da divisão celular e tem sido sugerido que a saída prematura do ciclo celular e a interferência com o tipo de divisão de células progenitoras pode causar microcefalias. O objetivo des...

  7. Recolección de células madre en sangre periférica mediante aféresis de grandes volúmenes

    OpenAIRE

    Greivin Zumbado-Salas; Miguel Rodríguez-Pineda; Xinia Rojas-Camacho; Carlos Rojas-Solano; Hever Herrera-Álvarez

    2014-01-01

    Antecedentes: evaluar el rendimiento y calidad de las recolecciones de células madre en sangre periférica realizadas en el Hospital México entre junio del 2010 hasta Junio del 2012, dado que existe una dosis mínima de células CD34+ (células progenitoras hematopoyéticas) que definen la posibilidad de éxito del injerto en el trasplante de células madre. Métodos: estudio retrospectivo utilizando los registros de los pacientes y los procedimientos de recolecciones de células madre por aféresis ef...

  8. Identificación, caracterización y aislamiento de células madre somáticas del endometrio murino y humano.

    OpenAIRE

    Cervelló Alcaraz, Irene

    2008-01-01

    RESUMEN El presente trabajo de investigación tiene como objetivo la identificación de células madre somáticas en el endometrio murino y humano. En la mayoría de los tejidos de individuos adultos, existen pequeñas poblaciones de células indiferenciadas que poseen la capacidad de diferenciarse a tipos celulares maduros, dividiéndose a su vez para mantener el balance necesario de células progenitoras indiferenciadas. Estas células reciben el nombre de células madre somáticas y se caracteri...

  9. Planetary nebulae in the magellanic clouds

    Directory of Open Access Journals (Sweden)

    P. Leisy

    2000-01-01

    Full Text Available Presentamos observaciones opticas y UV de PNe y derivamos sus abundancias y las implicaciones para la evoluci on qu mica. Observamos la reacci on HBB y el decremento del ox geno en las estrellas m as masivas por la reaci on ON, as como una producci on de ox geno (as como carbono durante el 3er dragado (el efecto es m as e ciente a bajas metalicidades. El ox geno no puede ser usado para inferir la composici on inicial de la estrella progenitora, debemos usar otros elementos como azufre o arg on.

  10. Incidencia de neoplasias hematológicas en el Área Metropolitana de Bucaramanga, 2000-2004

    OpenAIRE

    Claudia Janeth Uribe Pérez; Nathali Johanna Gómez; Erika Eliana Meza Durán

    2008-01-01

    Resumen SummaryAntecedentes: Las lesiones hematooncológicas son un grupo de neoplasias generadas por alteraciones células progenitoras hematopoyéticas. Este tipo de lesiones afectan a la población en general, con un porcentaje importante de ocurrencia en la población infantil. En el Área Metropolitana de Bucaramanga (AMB) estos trastornos se ubican dentro de las lesiones malignas más frecuentes region (2000 - 2004). Metodología: El Registro Poblacional del AMB realiza un proceso de búsqueda y...

  11. Implante de progenitores neurales en un modelo de lesión del sistema oculomotor

    OpenAIRE

    Morado Díaz, Camilo José

    2015-01-01

    Falta palabras clave El implante de células progenitoras neurales en el sistema nervioso central lesionado es una poderosa herramienta reparadora. Sin embargo, aún no se han evaluado extensamente los efectos de dichos implantes sobre el patrón de disparo y la sinaptología de las neuronas lesionadas. En este estudio se analizó si los progenitores neurales implantados en el sitio de lesión son capaces de restaurar las características de disparo y las aferencias sinápticas alteradas en las ne...

  12. Caracterização do estilo alimentar de crianças com perturbações alimentares

    OpenAIRE

    Viana, Victor; Guerra, Paula; Coelho, Alda; Almeida, Paulo; Guardiano, Micaela; Vaz, Rute; Guimarães, Júlia

    2008-01-01

    O objectivo deste trabalho foi investigar o comportamento alimentar, de um grupo de crianças com perturbações alimentares comparativamente a crianças normo-ponderais, com excesso de peso e obesas.Foram avaliadas 124 crianças dos dois sexos com idades entre os 3 e 13 anos das quais 26 tinham perturbações alimentares, 33 eram normo-ponderais, 32 tinham excesso de peso e 33 eram obesas.Foi realizada a avaliação antropométrica das crianças e progenitoras e calculados os Z scores de IMC das crianç...

  13. Estudo das combinações KIR2DL4 e ligante HLA-G em pacientes com indicação de transplante de células-tronco hematopoieticas

    OpenAIRE

    Gonçalves, Carlos Eduardo Ibaldo

    2013-01-01

    Resumo: A leucemia mieloide aguda (LMA) é um grupo heterogéneo de doenças clonais do tecido hematopoietico, que é caracterizada pela proliferação anormal de células progenitoras da linhagem mieloide, resultando na produção insuficiente de células sanguíneas maduras normais, com a consequente substituição de tecido normal. A leucemia linfoide aguda (LLA), um outro grupo heterogêneo de doenças clonais de tecido hematopoietico, é um câncer das células brancas do sangue, caracterizada pela prolif...

  14. Caracterización de las unidades de sangre de cordón procedentes de donantes con patología obstétrica.

    OpenAIRE

    López Sánchez, Mara

    2007-01-01

    RESUMEN INTRODUCCIÓN: La sangre de cordón umbilical (SCU) es una alternativa al empleo de médula ósea o sangre periférica de donantes no emparentados o de donantes familiares con disparidad HLA en trasplantes de precursores hematopoyéticos. JUSTIFICACIÓN. Conocer los factores obstétricos que mejoran la calidad de la SCU es importante para soslayar el incoveniente del contenido limitado en células progenitoras. Así se optimiza la selección de las donantes y la recogida de la sangre para ...

  15. Isolamento, caracterização, ativação e diferenciação em linhagens mesenquimais de pericitos cardíacos humanos

    OpenAIRE

    de Aguiar, Alessandra Melo

    2012-01-01

    Resumo: Células residentes teciduais são atualmente identificadas como populações de células progenitoras promissoras para terapias celulares. Neste trabalho, foi realizado o isolamento de células cardíacas humanas que expressam a enzima fosfatase alcalina, e estas células apresentaram características de célula-tronco mesenquimais (CTM). Foram utilizadas amostras de 24 doadores cadavéricos provenientes do Banco de Homoenxertos Humanos da Santa Casa de Misericórdia de Curitiba. O tempo médio d...

  16. Fracaso renal agudo en el trasplante de progenitores hematopoyéticos: análisis de la incidencia, factores de riesgo e implicaciones pronósticas. Valor pronóstico y en el diagnóstico precoz de la cistatina c plasmática

    OpenAIRE

    Solís Salguero, Miguel Ángel

    2015-01-01

    El trasplante de progenitores hematopoyéticos es el único tratamiento curativo de muchas enfermedades hematológicas, algunas alteraciones metabólicas y ciertas inmunodeficiencias. Persigue regenerar el tejido hematopoyético cuya función resulta insuficiente, bien por una enfermedad primaria de la médula ósea o a consecuencia de un tratamiento de quimioterapia y/o radioterapia. Precisa un rescate de la función hematopoyética con la obtención de células progenitoras que puedan regenerar la f...

  17. NADPH oxidasas como diana terapéutica en leucemia meloide crónica (CML)

    OpenAIRE

    Sánchez Sánchez, Beatriz

    2014-01-01

    [ES]El objetivo general de este trabajo fue analizar el potencial de la familia NADPH oxidasa como diana terapéutica en leucemia mieloide crónica. Para desarrollar nuestro estudio utilizamos dos líneas celulares distintas de LMC, denominadas K562 y Boff210. Además utilizamos células mononucleadas (CMNs) de médula ósea de pacientes en fase crónica de la enfermedad y recién diagnosticados, de las cuales seleccionamos también las células hematopoyéticas progenitoras CD34+. La metodología requeri...

  18. Alteraciones óseas asociadas con Diabetes mellitus: mecanismos patogénicos y estrategias de tratamiento con alendronato

    OpenAIRE

    Chuguransky, Sara Rocío

    2016-01-01

    Objetivos generales: Investigar las alteraciones óseas que se desarrollan en un modelo murino de diabetes leve. Investigar el efecto de los AGEs sobre células progenitoras de médula ósea (CPMO) en cultivo, así como el rol del alendronato sobre dichos efectos. Objetivos específicos: 1. Analizar el efecto de AGEs y alendronato sobre la diferenciación de CPMO al fenotipo osteoblástico, adipogénico y condrogénico en cultivo. 2. Investigar la capacidad de diferenciación osteogénica, ad...

  19. Estudos sobre tuberculose

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    A. Fontes

    1917-01-01

    Full Text Available Assim em resumo pensamos que a hipersensibilidade na infeção tuberculosa é a expressão duma reação celular, autonoma e individual, consequente á agressão brusca e á destruição (dijestão incompleta dos toxicos bacilares (proteinas, globulinas e lipoides, em combinação intima ou isoladamente; a adição aos toxicos bacilares de lipoides diversos (cholesterina, lecitina, esters e principios mal definidos existentes no oleo de figado de bacalhau, atenua a sua função hipersensibilidade porque torna esses toxicos mais facilmente incorporaveis á celula sensivel por adsorpção da substancia toxica ao lipoide. Esses corpos penetram assim no interior das celulas levando comsigo ativadores dos processos enzimaticos que não so favorecem uma elaboração dijestiva mais perfeita como ainda uma melhor produção de anticorpos. O aparecimento de pequenas modalidades reacionarias no decurso duma immunisação ativa contra os antijenos saturados por lipoides mostra a necessidade dum processo de desintegração para que a função toxica se manifeste.

  20. Estudo comparativo das inclusões do alastrim e da vacina no macaco (Macacus rhesus A comparison of the inclusion bodies of alastrim and vaccinia in the monkey (Macacus rhesus

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    C. Magarinos Torres

    1934-02-01

    Full Text Available Vesiculas e pustulas contendo numerosas inclusões citoplasmicas nas celulas epidermicas, foram regularmente produzidas no macaco (Macacus rhesus, quer com o virus do alastrim, quer com o da vacina, após inoculação endovenosa e sem previa escarificação. O virus do alastrim parece menos virulento para essa especie de macaco que o da vacina. Ao passo que 12 macacos rhesus injetados por via endovenosa com sete amostras diferentes de virus do alastrim, após apresentarem com regularidade um infecção experimental, sobreviveram e se conservaram em boa saúde, a injecção endovenosa do virus da vacina recentemente preparado (polpa bruta produziu a morte em 2, dentre 4 animais experimentados. 2. - Foram notadas diferenças pequenas, mas nitidas, na morfologia das inclusões do alastrim e da vacina, em material fixado no liquido de Helly, incluido em parafina e corado pela hematoxilina-eosina. Dizem elas respeito ao numero de inclusões encontradas em cada celula epidermica e às suas reações de coloração. 3. - As inclusões do alastrim, quando apresentam grandes dimensões, conservam-se unicas ou solitarias no citoplasma das celulas epidermicas do macaco rhesus, e coram-se em tonalidade que varia do azul escuro ao cinzento-azulado. Comtudo, em celulas que sofreram necrose, ou naquelas contendo 2 a 4 inclusões de pequenas dimensões, por vezes elas se mostram coradas em roseo. 4. - As inclusões da vacina, quando em faze adeantada de desenvolvimento, são multiplas nas celulas epidermicas do macaco rhesus e mostram, regularmente, uma policromatofilia caracteristica.1. - Vesicles and pustules containing numerous cytoplasmic inclusion bodies within the epidermal cells were regularly produced in monkeys (Macacus rhesus by intravenous inoculation either of alastrim virus or of recently prepared vaccine emulsion, no previous scarifications being required. Alastrim virus seems less virulent for this species of monkey than the virus of vaccinia is

  1. THE SAN PEDRO MÁRTIR PLANETARY NEBULA KINEMATIC CATALOGUE: EXTRAGALACTIC PLANETARY NEBULAE

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    M. G. Richer

    2010-01-01

    Full Text Available Presentamos datos cinemáticos para 211 nebulosas planetarias brillantes en once galaxias del Grupo Local: M31 (137 NPs, M32 (13, M33 (33, Fornax (1,Sagittarius (3, NGC 147 (2, NGC 185 (5, NGC 205 (9, NGC 6822 (6, Leo A (1, y Sextans A (1. Adquirimos los datos en el Observatorio Astronómico Nacional en la Sierra de San Pedro Mártir con el telescopio de 2.1 m y el espectrómetro Manchester Echelle en la línea de [O III]l 5007 con una resolución de 11 km s¿1. Observamos algunos objetos en H¿. La cinemática de nebulosas planetarias brillantes no depende fuertemente de la metalicidad o la edad de la población estelar progenitora en sus galaxias huéspedes, aunque existen pequeñas diferencias sistemáticas. La cinemática y la luminosidad en Hb de las cáscaras nebulares requieren la aceleraci ón de las cáscaras durante la evolución temprana de las estrellas centrales. Así, la cinemática representa otro argumento a favor de estrellas progenitoras similares para las nebulosas planetarias brillantes en todas galaxias.

  2. SEVERAL WAYS TO BRIGHTNESS

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    M. G. Richer

    2011-01-01

    Full Text Available Las luminosidades máximas, los cocientes de abundancias químicas y la cinemática interna de las cáscaras nebulares de nebulosas planetarias extragalácticas brillantes no dependen fuertemente de las características de las poblaciones estelares progenitoras en una galaxia. Esta falta de variación sugiere que las nebulosas planetarias más brillantes tienen estrellas progenitoras similares en todas las galaxias, un resultado inesperado teóricamente dada las metalicidades y las historias de formación estelar. Sin embargo, existen diferencias pequeñas y consistentes en cuanto a las luminosidades y la cinemática que sí dependen de las propiedades de las poblaciones estelares en las galaxias huéspedes y de la metalicidad en particular. Estas diferencias sugieren que necesariamente observamos las nebulosas planetarias en distintas galaxias en distintos estados evolutivos, corresponden las pertenecientes a las galaxias elípticas y los bulbos de espirales a fases más tempranas. Entonces, deben existir múltiples vías para la producción de las nebulosas planetarias intrínsecamente m´as brillantes.

  3. Mapeamento do uso e cobertura da terra a partir da segmentação e classificação de imagens-fração solo, sombra e vegetação derivadas do modelo linear de mistura aplicado a dados do sensor TM/Landsat5, na região do reservatório de Tucuruí - PA Mapping land use cover using segmentation and classification of fraction images, soil, shade and vegetation, derived from a linear mixing model applied to Landsat-5 TM data, Tucuruí reservoir region - Pará

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    Cíntia Honório Vasconcelos

    2004-09-01

    Full Text Available Técnicas de sensoriamento remoto são fundamentais para o monitoramento das mudanças de uso da terra, principalmente em áreas extensas como a Amazônia. O mapeamento de uso da terra, geralmente é realizado por métodos de classificação manual ou digital pixel a pixel, os quais consomem muito tempo. Este estudo aborda a aplicação do modelo linear de mistura em uma imagem Landsat-TM segmentada para o mapeamento das classes de uso da terra na região do reservatório de Tucuruí-PA para os anos de 1996 e 2001.Remote sensing techniques are mandatory for monitoring land use changes in large areas such as the Amazon. Land use mapping is usually performed by both manual and digital pixel based classification methods which are cost and time-consuming. In this study an image segmentation approach is applied to unmix TM-Landsat images for mapping land use classes in Tucuruí-PA reservoir region to 1996 and 2001.

  4. Study by Monte Carlo simulation of the absorbed dose in cells of breast cancer of the line MDA-MB231, due to sources of {sup 111}In, {sup 177}Lu and {sup 99m}Tc internalized in the nucleus. First results; Estudio por simulacion Monte Carlo de la dosis absorbida en celulas de cancer de seno de la linea MDA-MB231, debida a fuentes de {sup 11I}n, {sup 177}Lu y {sup 99m}Tc internalizadas en el nucleo. Primeros resultados

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E. L.; Perez A, M., E-mail: leticia.rojas@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2011-11-15

    The necessity to design innovative treatments and to diagnose the cancer early, has taken to investigate therapies at cellular and molecular level. The design of appropriate radio-molecules to these therapies makes necessary to characterize in way exhaustive radionuclides that they are of accessible production in our country and to study as distributing the dose at cellular level with bio-molecules glued them. In this context, was realized the present work. Using Monte Carlo simulation, the energy deposited in a geometric model of cells of breast cancer was obtained, MDA-MB231, due to different radionuclides. The energy deposited in the nucleus was evaluated, in the cytoplasm and in the membrane of the cell, using the simulation code Monte Carlo Penelope 2008. A punctual source was simulated in the center of the cell nucleus. In each case all the emissions of each radionuclide majors to 400 eV were simulated. The energies deposited by disintegration in the nucleus, cytoplasm, membrane of the cell and in a sphere of 2 cm surrounding the source (in eV) were: 4.30E3, 4.85E2, 1.07E2 and 3.29E4, correspondingly, for the {sup 111}In; 4.46E3, 3.76E3, 1.26E3 and 1.33E5 for the {sup 177}Lu and; 2.12E3, 2.58E2, 9.33E1 and 1.88E4 for the {sup 99m}Tc. We can conclude that if the union of these radionuclides happens to a compound that was internalized to the cell nucleus, the best for therapy at this level is the conjugate with the {sup 177}Lu, followed by that with {sup 111}In and in third place that with {sup 99m}Tc. (Author)

  5. ANÁLISIS DE SENSIBLIDAD GLOBAL DE UN MODELO DE LECHUGAS (Lactuca sativa L.) CULTIVADAS EN INVERNADERO

    OpenAIRE

    López-Cruz, Irineo L.; Raquel Salazar-Moreno; Abraham Rojano-Aguilar; Agustín Ruiz-García

    2012-01-01

    El análisis de sensibilidad de un modelo matemático es relevante ya que permite determinar como la incertidumbre de las salidas del modelo puede ser asignada a sus variables de entrada. Hasta ahora se aplican métodos locales basados en el cálculo de derivadas parciales para modelos de cultivos en invernadero. Sin embargo, la limitante principal del análisis de sensibilidad local es que proporciona información únicamente en el punto base donde las derivadas son calculadas, sin tomar en c...

  6. Propiedades de las soluciones de sistemas estacionarios de la dinámica de poblaciones con difusión lineal y no lineal

    OpenAIRE

    Suárez Fernández, Antonio

    1999-01-01

    En esta Memoria se estudian algunas de las propiedades de las soluciones de ciertas Ecuaciones en Derivadas Parciales no Lineales que modelan el comportamiento de dos especies que habitan en un mismo dominio y cuya difusión es, o bien, no lineal o lineal. En esta Memoria se estudian algunas de las propiedades de las soluciones de ciertas Ecuaciones en Derivadas Parciales no Lineales que modelan el comportamiento de dos especies que habitan en un mismo dominio y cuya difusión es, o bien, no...

  7. Operadores Pseudodiferenciales en Clases no Casianalíticas de Tipo Beurling

    OpenAIRE

    Jornet Casanova, David

    2015-01-01

    Los operadores pseudodiferenciales son generalizaciones de los operadores integrales singulares y de los operadores en derivadas parciales con coeficientes variables. A cada operador le corresponde un símbolo, que es una función infinitamente diferenciable y cuyas derivadas parciales cumplen ciertas estimaciones. El próposito es introducir estos operadores en el contexto de las clases no casianalíticas de tipo Beurling, clases que recientemente han recibido mucha atención, por ser más gene...

  8. Métodos efectivos en anillos de operadores diferenciales y en sistemas hipergeométricos

    OpenAIRE

    Hartillo Hermoso, Isabel

    2002-01-01

    El Análisis Algebraico, o teoría de D-m&oa cute;dulos, trata el estudio de los sistemas de ecuaciones -- en derivadas parciales desde el punto de vista del álgebra y la geometría. Esta teoría generalizada la teoría clásica de ecuaciones diferenciales ordinarias con coeficientes -- en una variables real o compleja. Un tipo especial de sistemas de ecuaciones lineales en derivadas parciales son los sistemas hipergeométricos o de Grelfand-Kapranov-Zele-Viuski. En los casos de sistemas definidos p...

  9. Ampliació de dictamen : exigència d'immediació i aplicació de la tesi d'heterogeneïtat

    OpenAIRE

    Xandri Molas, Lluís

    2011-01-01

    Ampliació de Dictamen de Dret Penal: Possibilitats de revisió dels fets provats en cassació atesa l'exigència d'immediació derivada de la doctrina Tribunal Constitucional i aplicació de la tesi d'heterogeneïtat delictiva. Ampliación de Dictamen de Derecho Penal: Posibilidades de revisión de los hechos probados en casación dada la exigencia de inmediación derivada de la doctrina Tribunal Constitucional y aplicación de la tesis de heterogeneidad delictiva. Expansion of Criminal Law Opinio...

  10. Pn-carbon yields and the chemical evolution of the galaxy

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    Leticia Carigi

    2002-01-01

    Full Text Available Calculo dos conjuntos de rendimientos estelares observacionales de carbono para estrellas de masa intermedia y baja basados en abundancias derivadas a partir de l neas permitidas y prohibidas de C II y C III ( 4267 y 1906+1909, respectivamente. Comparando los valores de C/O observados en la vecindad solar y en regiones H II Gal acticas con aquellos predichos por modelos de evolucion qu mica para la Galaxia que suponen estos rendimientos observacionales, se concluye que las abundancias de C basadas en l neas permitidas son mejores que aquellas derivadas a partir de l neas prohibidas.

  11. Gestão organizacional sob a lógica da competência: aplicação na pequena empresa.

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    Mariana Musetti Munck

    2008-02-01

    Full Text Available Este estudo, sustentado nas premissas teoricas do modelo de gestão por competencias, objetiva explorar, descrever e mudar a sistematica de execução das atividades de uma pequena empresa de consultoria. Orientando-se por autores que propoem a operacionalização do conceito de competencias nas organizacões, construiram-se quadros de referencias para as celulas da organização de modo que houvesse mais transparencia e consistencia nas ações de gestão, e isso representa um grave problema das pequenas empresas. Os quadros são compostos de atributos como missão, atribuições, contribuições, indicadores de resultados e competencias, todos definidos com base nas estrategias e nos objetivos almejados pela organização. Ante a proposta de não apenas explorar e descrever, mas tambem de mudar, o estudo utilizou como orientação metodologica a pesquisa-ação. Esse metodo não se limita apenas a descrever uma situação, mas tambem pretende desencadear, em certos casos, mudancas no seio da coletividade envolvida. O proprio processo de busca e os resultados alcancados demonstraram, a principio, que a estruturação de uma empresa por competencias gera turbulencias iniciais, principalmente pela radicalidade da mudança (neste caso e pelas particularidades do conceito. A nova estrutura tem provocado mudanças culturais, sobretudo na açao dos gestores que tem agora informações claras sobre as atribuições e exigencias cabiveis a cada celula, bem como de seus respectivos indicadores de desempenho.

  12. Cell death induced by tamoxifen in human blood lymphocytes cultivated in vitro = Morte celular induzida pelo tamoxifeno em linfócitos humanos cultivados in vitro

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    Selma Candelária Genari

    2010-10-01

    Full Text Available Many chemotherapeutic agents with a potential against solid tumors or leukemia can cause lymphopenia. Tamoxifen (TAM is a synthetic non-steroidal anti-estrogen drug employed in female breast cancer treatment. The present study investigated the capacity of TAM to induce cell death in human lymphocytes cultivated in vitro. Lymphocytes were obtained from young (25-30 years; n = 3 and elderly women (58-77 years; n = 3 and cultivated for 24 or 48h, with or without TAM (20 ƒÊM. After the culture, cell viability, immunocytochemical response and ultrastructure were evaluated. TAM affected lymphocytes in a time- dependent manner, and cells obtained from elderly women were the most sensitive to TAM. Immunocytochemicalanalysis evidenced higher frequency of apoptosis in treated cells, and the ultrastructural study revealed autophagic vacuoles, differing from the controls. In summary, the treated lymphocytes were affected by TAM, leading to cell death by apoptosis and autophagy.Muitos agentes quimioterapicos com potencial contra tumores solidos ou leucemias podem causar linfopenia. O Tamoxifeno (TAM e um agente antiestrogeno nao-esteroidal empregado no tratamento de cancer de mama feminino. O presente trabalho investigou a capacidade do TAM em induzir morte celular em linfocitos humanos cultivados in vitro. Oslinfocitos foram obtidos de mulheres jovens (25-30 anos; n = 3 e idosas (58-77 anos; n = 3 e cultivados por 24 ou 48h, com ou sem TAM (20 ƒÊM. Apos a cultura, foram analisadas a viabilidade celular, a resposta imunocitoquimica e a ultraestrutura. Os resultados indicam que o Tamoxifeno induziu morte celular em linfocitos de ambos os grupos, entretanto, as celulas das mulheres idosas apresentaram-se mais sensiveis ao tratamento. A analise imunocitoquimica mostrou maior frequencia de apoptose nas celulas tratadas e o estudo ultraestrutural revelou vacuolos autofagicos nos linfocitos expostos ao Tamoxifeno. Em conclusao, nosso estudo revelou que o TAM

  13. Estudio de la expresión de MYBL2 y de miRNAs en la leucemia mieloblástica aguda. Papel del miR-30a en la regulación de MYBL2 y en la proliferación celular

    OpenAIRE

    Llop García, Marta

    2015-01-01

    La leucemia mieloblástica aguda (LMA) es una enfermedad heterogénea caracterizada por la transformación neoplásica de las células progenitoras hematopoyéticas. Los blastos leucémicos se acumulan en sangre periférica y en médula ósea, desplazando a las células sanguíneas normales y provocando insuficiencia medular, que se acompaña de infecciones, anemia y desórdenes de la coagulación. Los blastos leucémicos pueden presentar alteraciones genéticas y epigenéticas que, además de explicar la apari...

  14. Influência do stresse oxidativo na morte de células de Leucemia Aguda em cultura : relação com os níveis de 5-hidroximetilcitosina

    OpenAIRE

    Leite, Joana Filipa da Silva

    2012-01-01

    A leucemia linfoblástica aguda (LLA) é uma neoplasia do sistema hematopoiético que resulta da transformação maligna das células progenitoras linfoides, B ou T, com consequente desregulação da proliferação e/ou bloqueio da diferenciação destas células, conduzindo à acumulação de células imaturas (linfoblastos). No entanto, a maioria das alterações genéticas que ocorrem na LLA não são suficientes para induzir a progressão da doença, o que sugere que existem outros factores genéti...

  15. A leveza do centauro

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    Marcus Vinicius de Freitas

    2012-10-01

    Full Text Available O presente artigo procura analisar os procedimentos narrativos de Moacyr Scliar em O centauro no jardim, a partir da teoria do hibridismo, derivada de Mikhail Bakhtin e Donna Haraway. Como elemento de fundo, o artigo procura discutir o papel e os limites do saber teórico, seu lugar como prática cultural.

  16. Estudio teórico de un modelo simplificado sobre angiogénesis

    OpenAIRE

    Delgado Delgado, Manuel; Suárez Fernández, Antonio

    2007-01-01

    En esta comunicación presentamos un sistema en ecuaciones en derivadas parciales no lineales simplificado que modela un proceso básico en el crecimiento tumores: la angiogénesis. Presentamos resultados de existencia de solución positiva del sistema estacionario en función de los parámetros del sistema.

  17. Simetrías potenciales de un modelo matemático que describe las vibraciones de una viga

    OpenAIRE

    Bruzón Gallego, María de los Santos; Gandarias Núñez, María Luz; Camacho Moreno, José Carlos

    2007-01-01

    En este trabajo presentamos un estudio, desde el punto de vista de la teoría de las simetrías potenciales clásicas y no clásicas para ecuaciones en derivadas parciales, del modelo que describe las vibraciones de una viga.

  18. Análisis y control de algunas EDP no lineales con origen en mecánica

    OpenAIRE

    Doubova Krasotchenko, Anna

    2000-01-01

    "En esta Memoria, analizaremos diversos problemas de controlabilidad relacionados con ecuaciones en derivadas parciales (EDP) de evolución de tipo parabólico o hiperbólico, motivadas por problemas con origen en Mecánica".

  19. Cálculo de Ordem Fracionária e Aplicações

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    José Paulo Carvalho dos Santos

    2012-12-01

    Full Text Available O objetivo desse trabalho é divulgar a teoria de Calculo Fracionário. O texto contém as principais definições e alguns resultados importantes para um primeiro estudo da teoria de integrais e derivadas de ordem arbitrária.

  20. Educación especial: integración escolar y necesidades educativas especiales

    OpenAIRE

    Grau Rubio, Claudia

    1994-01-01

    Se realiza una descripción histórica de la educación especial y de sus implicaciones curriculares y organizativas. Se describen las necesidades educativas especiales derivadas de discapacidad motora, sensorial e intelectual y la respuesta educativa.

  1. Análisis de las barreras y oportunidades legales-éticas de la comunicación y disculpa de errores asistenciales en España

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    Priscila Giraldo

    2016-03-01

    Discusión: existe un consenso sobre la falta de responsabilidad derivada de una comunicación-disculpa y la necesidad de iniciar un programa de comunicación a través del soporte a los/las médicos/as.

  2. Una aplicación de las funciones débilmente contractivas a problemas de valor en la frontera de funciones con valores en intervalos

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    Vladimir Angulo-Castillo

    2014-01-01

    Full Text Available Se estudia la existencia y unicidad de soluciones para problemas de valor en la frontera asociadas a ecuaciones diferenciales de funciones con valores en intervalos, usando la derivada de Hukuhara y algunos teoremas de punto fijo de funciones débilmente contractivas definidas en conjuntos par- cialmente ordenados.

  3. Escuela comunal del distrito de Waine /EE. UU.

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    Kessler, William

    1982-02-01

    Full Text Available Not available.Este proyecto, galardonado con diversos premios en Estados Unidos, es la primera unidad de un programa de descentralización de estudios. En su realización tuvo tanta importancia su adecuada adaptación a las condiciones del terreno —en el que había un bosque y edificios antiguos de obligada conservación— como el dar cumplida satisfacción a las muy distintas necesidades específicas derivadas de la gran diversidad de ramas educativas que abarca. También intervino en su concepción la posibilidad de su expansión futura, previendo las necesidades derivadas del aumento de estudiantes o de nuevas especialidades.

  4. Empleo y economías de aglomeración: el caso de la industria de la carne, productos lácteos y conservas alimenticias, 1988-2003

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    Rogelio Varela Llamas

    2009-01-01

    Mínimos Cuadrados Generalizados, se obtienen resultados que sugieren que las economías externas derivadas de la especialización y diversidad productiva no afectan positivamente al empleo; con excepción de la industria de conservas alimenticias. Asimismo, se determina que el empleo en el resto de las ramas del subsector 31 presenta un efecto positivo y significativo sobre cada una de las tres ramas estudiadas.

  5. Tumbas rupestres en el Alto Mondego (Guarda, Portugal. Patrones de distribución, significados y construcción del paisaje rural altomedieval

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    Tente, Catarina

    2015-01-01

    las formas de organización social: las tres primeras reflejan una organización de base familiar, mientras que la última es derivada de un poder supralocal. Estas manifestaciones funerarias rupestres atestiguan una intención deliberada de marcar el paisaje y los territorios familiares y comunitarios (espacios productivos y de habitación y de la apropiación simbólica y social de los paisajes rurales.

  6. Evolución de la intervención psicológica de la artitris reumatoide

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    Japcy Margarita Quiceno

    2011-01-01

    enfoques de intervención que se han centrado en la expresión emocional abierta de la afectividad negativa. Se termina resaltando la importancia del desarrollo de programas de intervención en pacientes con artritis reumatoide, basados en la potenciación de las emociones positivas, la resiliencia y otras variables derivadas de la psicología positiva.

  7. La energía nos mueve. Ciencia para una energía más limpia, sostenible y accesible

    OpenAIRE

    CSIC - Vicepresidencia Adjunta de Organización y Cultura Científica (VAOCC)

    2012-01-01

    Estos materiales están dirigidos a la divulgación, el fomento de la cultura científica y las vocaciones científicas, y la docencia. Es posible copiar, compartir y distribuir sus contenidos siempre y cuando se reconozca la autoría, no haya fines comerciales y no se realicen obras derivadas (CC BY-NC-ND 4.0).

  8. Cálculo subdiferencial de segundo orden en variedades riemannianas, con aplicaciones a la teoría de EDP's de segundo orden y a la teoría del punto fijo

    OpenAIRE

    Sanz Alonso, Beatriz

    2009-01-01

    Esta tesis aporta resultados de existencia y unicidad de soluciones de viscosidad para ecuaciones en derivadas parciales de segundo orden en variedades riemannianas y resultados de existencia de ceros y puntos fijos para funciones conjunto-valoradas en variedades riemannianas, que se demuestran aplicando teoría de cálculo subdiferencial. Uno de los primeros objetivos que nos planteamos al comenzar este trabajo doctoral, fue continuar las fructíferas investigaciones que dieron lugar a la tesis...

  9. Ecuaciones Diferenciales II

    OpenAIRE

    Mañas Baena, Manuel; Martínez Alonso, Luis

    2015-01-01

    En este manual se revisan diferentes aspectos sobre las ecuaciones diferenciales en derivadas parciales de utilidad para los físicos. Se elaboraron como notas de clase de la asignatura Ecuaciones II, del plan 1993 de la Licenciatura de Física de la UCM. Actualmente cubre un 75% de la asignatura Métodos Matemáticos II del Grado de Física de la UCM.

  10. Simulación numérica en Ingeniería y Ciencias con MATLAB + COMSOL Multiphysics

    OpenAIRE

    Ivorra, Benjamin

    2015-01-01

    En este seminario se tratan las posibles interacciones entre el entorno de programación matricial MATLAB y el software COMSOL Multiphysics, que permite resolver de forma intuitiva sistemas de ecuaciones en derivadas parciales con diversas implementaciones del método de los elementos finitos. Este tipo de ecuaciones modelan los fenómenos correspondientes a los problemas de mecánica de fluidos, transferencia de calor, electromagnetismo, etc. La posibilidad del uso combinado es importante, en pa...

  11. Solución numérica de las ecuaciones de Navier Stokes en coordenadas curvilíneas

    OpenAIRE

    Rivera Ramírez, Carla Alejandra

    2002-01-01

    En la solución numérica de algunos modelos matemáticos, tales como los que usan ecuaciones diferenciales parciales, surge el problema de discretizar el dominio de cálculo; comunmente se usan las mallas rectangulares cartesianas para esta discretización, ya que su estructura rectangular, permite identificar facilmente los nodos vecinos para la aproximación de las derivadas.

  12. Modelo de evaluación de la sostenibilidad territorial de Bogotá: Una propuesta multicriterio con enfoque modelizador de la movilidad de las ciudades

    OpenAIRE

    William Barragán Zaque; Alexander Martínez Rivillas; Aureliano Campos Orjuela

    2010-01-01

    El objetivo principal de este artículo es mostrar la capacidad predictiva de un modelo de sostenibilidad territorial para Bogotá, fundamentado en información multidimensional primaria y derivada. Su capacidad predictiva reside en la pertinencia de las variables consideradas y en la articulación consistente de ellas, para explicar fenómenos multifactoriales como la movilidad sostenible de una ciudad. Finalmente, se presenta un conjunto de escenarios posibles para mejorar los procesos de implem...

  13. Acceso a la información: hacia la democratización de la administración pública

    Directory of Open Access Journals (Sweden)

    Ferreyra, Leandro E.

    2013-12-01

    Full Text Available El trabajo se encuentra estructurado en tres partes. En la primera se intenta delimitar un concepto de derecho de acceso a la información pública y de las complejidades derivadas del mismo de acuerdo a lo resuelto y normado en diversos sistemas. En la segunda, se analiza el régimen argentino y sus déficits. En la tercera, se esbozan consideraciones y propuestas en base a lo expuesto anteriormente.

  14. Etiquetaje directo de ovocitos y embriones

    OpenAIRE

    Novo Bruña, Sergio

    2014-01-01

    La correcta trazabilidad de las muestras derivadas de la práctica de las técnicas de reproducción asistida principalmente ovocitos, semen y embriones es esencial, tanto en la reproducción asistida de humanos como de animales de renta. Los sistemas actualmente destinados a mantener identificada la muestra durante su paso por el laboratorio y a preservar dicha trazabilidad presentan ciertas limitaciones. En esta tesis se ha desarrollado un sistema de etiquetaje direc...

  15. Charles Darwin y El origen de las especies

    OpenAIRE

    CSIC - Vicepresidencia Adjunta de Organización y Cultura Científica (VAOCC)

    2009-01-01

    Estos materiales están dirigidos a la divulgación, el fomento de la cultura científica y las vocaciones científicas, y la docencia. Es posible copiar, compartir y distribuir sus contenidos siempre y cuando se reconozca la autoría, no haya fines comerciales y no se realicen obras derivadas (CC BY-NC-ND 4.0).

  16. Conflicto árabe-israelí y terrorismo: el Islam en la política internacional

    Directory of Open Access Journals (Sweden)

    Rodolfo Téllez-Cuevas

    2010-01-01

    Full Text Available El Islam es analizado desde un contexto político-internacional, con la premisa derivada del conflicto árabe-israelí de 1948. El mundo occidental ha cultivado dolosamente la idea de que todo lo islámico, musulmán o palestino se traduce en terrorismo y fundamentalismo, siendo que también aquél es un ejemplo de estas formas por imponer su hegemonía mundial.

  17. La globalización y la gestión financiera internacional

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Martínez Fajardo

    2003-06-01

    Full Text Available Este artículo constituye una reflexión acerca de la incidencia del proceso de globalización en la evolución reciente de las finanzas internacionales y en la expansión apoyada en la mayor capacidad de gestión de las empresas multinacionales. Dicho proceso se analiza de acuerdo con las pautas derivadas del reordenamiento de la estructura mundial de poder y su incidencia en el sistema financiero internacional.

  18. Controlabilidad de Sistemas Bilineales en el Plano

    OpenAIRE

    Laura Guarachi, Leonardo Ramiro

    2012-01-01

    El objeto principal de este trabajo son los sistemas de ecuaciones diferenciales que dependen de un parámetro u, control del sistema, tales sistemas se llaman sistemas de ecuaciones diferenciales controlables, los cuales, en general, describen procesos dinámicos de fenómenos físicos. Estos procesos se describen mediante sistemas de ecuaciones diferenciales ordinarios (EDO), ecuaciones en diferencias o a través de ecuaciones derivadas parciales. Una clase de sistemas de mucha im...

  19. Electromagnetism Tutorial (Tutorial de Eletromagnetismo)

    CERN Document Server

    Dantas, Christine C

    2009-01-01

    The present tutorial aims at covering the fundamentals of electromagnetism, in a condensed and clear manner. Some solved and proposed exercises have been included. The reader is assumed to have knowledge of basic electricity, partial derivatives and multiple integrals. ----- O presente tutorial visa cobrir os fundamentos do eletromagnetismo, de forma condensada e clara. Alguns exercicios resolvidos e propostos foram incluidos. Assume-se conhecimento de eletricidade basica, derivadas parciais e integrais multiplas.

  20. Fundamentos Matematicos De Teorias Sobre Espacios Noconmutativos

    CERN Document Server

    Dvoeglazov, V V

    2002-01-01

    In the talk we investigate the question of commutation of the whole-partial derivatives, which should be considered when the function, which is subjected to differentiation, has both explicit and implicit dependence. We apply the results to the quantum theories. -- En la platica investigamos la cuestion de conmutacion de derivadas parciales cuando la funcion sujeta a diferenciacion tiene dependencia tanto explicita como implicita. Aplicamos los resultados a teorias cuanticas.

  1. Biodiversidad

    OpenAIRE

    CSIC - Vicepresidencia Adjunta de Organización y Cultura Científica (VAOCC)

    2010-01-01

    Estos materiales están dirigidos a la divulgación, el fomento de la cultura científica y las vocaciones científicas, y la docencia. Es posible copiar, compartir y distribuir sus contenidos siempre y cuando se reconozca la autoría, no haya fines comerciales y no se realicen obras derivadas (CC BY-NC-ND 4.0).

  2. Entre moléculas

    OpenAIRE

    CSIC - Vicepresidencia Adjunta de Organización y Cultura Científica (VAOCC)

    2011-01-01

    Estos materiales están dirigidos a la divulgación, el fomento de la cultura científica y las vocaciones científicas, y la docencia. Es posible copiar, compartir y distribuir sus contenidos siempre y cuando se reconozca la autoría, no haya fines comerciales y no se realicen obras derivadas (CC BY-NC-ND 4.0).

  3. Derivative-based optimization in colour image filtering an application for derivative learning

    Directory of Open Access Journals (Sweden)

    A. Sapena

    2009-06-01

    Full Text Available La noción de derivada de una función y su aplicación a la optimización de funciones es un problema interesante e ilustrativo para los estudiantes de ingeniería. En este trabajo, desarrollamos un aplicación del concepto de derivada para la optimización del filtrado de imágenes en color. Ello implica ajustar el parámetro del filtro para obtener un rendimiento óptimo de filtrado. Proponemos maximizar la calidad de la imagen filtrada representada por la relación señal-ruido (Peak Signal-to-Noise Ratio, PSNR, que es una función del parámetro del filtro. El valor óptimo del parámetro se obtiene mediante un algoritmo basado en la aproximación de la derivada de la función del PSNR de manera que se obtenga la imagen filtrada óptima.

  4. H II Regions and Protosolar Abundances in Galactic Chemical Evolution

    Directory of Open Access Journals (Sweden)

    L. Carigi

    2011-01-01

    Full Text Available Presentamos modelos de evolución química del disco galáctico con diferentes rendimientos dependientes de Z. Encontramos que una tasa moderada de pérdida de masa en estrellas masivas de metalicidad solar produce un excelente ajuste con los gradientes de C/H y C/O del disco de la Galaxia. El mejor modelo reproduce: las abundancias de H, He, C y O derivadas de líneas de recombinación en M17, las abundancias protosolares y las relaciones C/O-O/H, C/Fe-Fe/H y O/Fe-Fe/H derivadas de estrellas de la vecindad solar. La concordancia del modelo con las abundancias protosolares implica que el Sol se originó a una distancia galactocéntrica similar a la actual. El modelo para r = 3 kpc implica que una fracción de las estrellas en la dirección del bulbo se formó en el disco interno. Nuestro modelo reproduce la relación C/O-O/H derivada de regiones H II extragalácticas en galaxias espirales.

  5. [Myelopathy secondary to an aneurysmal bone cyst of thoracic spine].

    Science.gov (United States)

    Navas-García, Marta; Penanes, Juan Ramón; Fraga, Javier; Sola, Rafael G

    2016-02-01

    Introduccion. Los quistes oseos aneurismaticos espinales son lesiones osteoliticas benignas muy infrecuentes constituidas por cavidades hematicas limitadas por septos osteoconectivos y celulas gigantes tipo osteoclastos. Clinicamente se manifiestan con dolor local, sintomas neurologicos secundarios a compresion medular, asi como fracturas, deformidades e inestabilidad vertebral. Presentamos un caso de quiste oseo aneurismatico espinal dorsal con sintomatologia neurologica, tratado mediante una reseccion microquirurgica completa, sin secuelas neurologicas asociadas. Caso clinico. Mujer de 47 años, sin antecedentes traumaticos previos, valorada por presentar un cuadro de parestesias de los miembros inferiores de semanas de evolucion. El estudio radiologico de resonancia magnetica dorsal demostro la existencia de una lesion litica de bordes bien delimitados y esclerosis marginal en D4, con afectacion de los elementos posteriores vertebrales y compresion del cordon medular subyacente. La lesion fue extirpada en su totalidad, con desaparicion de la clinica sensitiva tras la intervencion. El diagnostico anatomopatologico definitivo fue quiste oseo aneurismatico espinal. Conclusion. A pesar de su baja incidencia, los quistes oseos aneurismaticos espinales deben considerarse, en el diagnostico diferencial de los tumores oseos espinales, como una posible causa de mielopatia compresiva subaguda o cronica. La reseccion tumoral completa se considera el tratamiento de eleccion, el cual con frecuencia es curativo y asocia un buen pronostico del paciente a largo plazo.

  6. [First case described of isolated, complete and fluctuating cranial nerve III palsy heralding multiple myeloma].

    Science.gov (United States)

    León-Ruiz, Moisés; Benito-León, Julián; Sierra-Hidalgo, Fernando; García-Soldevilla, Miguel Ángel; Izquierdo-Esteban, Laura; Tejeiro-Martínez, José; Cabrera-Valdivia, Francisco; García-Albea Ristol, Esteban

    2015-02-01

    Introduccion. El mieloma multiple es la neoplasia de celulas plasmaticas mas frecuente. Al ser incurable, el tratamiento persigue obtener el mayor tiempo de supervivencia libre de clinica. Constituye una causa extremadamente rara de afectacion de los nervios craneales y es producido habitualmente por un plasmocitoma intracraneal. Presentamos un caso de mieloma multiple, que asociaba un plasmocitoma intracraneal y que comenzo clinicamente con paralisis aislada, completa y fluctuante del III nervio craneal. Caso clinico. Mujer de 63 años que acudio a urgencias por presentar un cuadro clinico oscilante, consistente en diplopia binocular horizontal y, posteriormente, cefalea. La exploracion neurooftalmologica revelo una paralisis completa del III nervio craneal derecho. Se solicito una tomografia axial computarizada craneal urgente, que revelo multiples lesiones osteoliticas diploicas, asociando una de ellas componente de partes blandas en la hendidura esfenoidal derecha. La paciente fue ingresada, y se le diagnostico posteriormente un mieloma multiple IgA-kappa. Tras recibir induccion quimioterapica y ser sometida a un trasplante autologo de progenitores hematopoyeticos, alcanzo la remision completa. Conclusiones. El mieloma multiple es un trastorno raro de los nervios craneales, una causa muy infrecuente de paralisis aislada y completa del III nervio craneal y menos aun fluctuante, y no se ha encontrado ningun caso publicado con este inicio clinico. Tener en cuenta las posibles manifestaciones neurooftalmologicas del mieloma multiple puede contribuir a un diagnostico precoz y a una incidencia positiva sobre el curso de esta enfermedad.

  7. Expresión episomal de toxina de pertussis genéticamente inactivada en Bordetella pertussis

    Directory of Open Access Journals (Sweden)

    Ernesto Marcos

    2010-01-01

    Full Text Available Bordetella pertussis es una bacteria Gram negativa, la cual constituye el agente etiologico de la tos ferina. La enfermedad se desencadena por el efecto conjunto de una serie de factores de virulencia expresados por la bacteria, los cuales se encuentran regulados por el sistema bvg. Uno de los factores de virulencia mas importantes es la toxina de pertussis, razon por la cual, se emplea de forma inactivada como el componente principal de las vacunas acelulares contra la enfermedad. La toxina de pertussis posee una estructura del tipo A-B compuesta por seis polipeptidos codificados en un operon unico. El polipeptido S1 constituye la subunidad enzimaticamente activa, la cual cataliza la transferencia de ADP-ribosa del NAD a la subunidad ALPHA de las proteinas G en celulas eucariotas, lo cual genera una serie de efectos biologicos dentro de los que se incluye: sensibilizacion a histamina, incremento de la secrecion de insulina y efectos inmunoestimuladores e inmunosupresores. El presente trabajo describe los procedimientos realizados para la obtencion de cepas de Bordetella pertussis productoras de elevadas concentraciones de toxina pertusica atenuada geneticamente. Para esto, se realizaron las sustituciones aminoacidicas Arg9 por Lys y Glu129 por Gly de la subunidad S1. El operon de la toxina de pertussis mutada se clono en un vector de amplio rango de hospedero bajo la regulacion de un promotor de expresion temprana (fhaB. Los clones obtenidos pudieran ser empleados como sistemas de expresion para produccion de vacunas acelulares en Cuba.

  8. Linfoma primario del sistema nervioso central en una paciente con lupus eritematoso sistémico

    Directory of Open Access Journals (Sweden)

    C. N. Pisoni

    2003-06-01

    Full Text Available Se presenta una paciente de 36 años con diagnóstico de lupus eritematoso sistémico tratada con prednisona y ciclofosfamida que se internó por cefalea, hemiparesia y hemianestesia braquiocrural derecha de dos semanas de evolución. Se realizó una tomografía computada y una resonancia magnética nuclear de cerebro que mostraron una lesión nodular frontal izquierda. Se efectuó una biopsia a cielo abierto de la lesión cerebral cuyo diagnóstico histopatológico fue linfoma B de celulas grandes, difuso. Se inició radioterapia, no completó el tratamiento por complicaciones y falleció. Son muy pocos los casos publicados de linfoma primario del sistema nervioso central asociado a lupus eritematoso sistémico.A 36 year-old woman with systemic lupus erythematosus was admitted to our hospital with headache, brachiocrural hemiparesis and hemianesthesia. She had been treated with prednisone and cyclophosphamide. CT scan and MRI revealed a 15 mm nodular mass enhanced with gadolinium in left frontal convexity. CNS biopsy was performed and a diffuse large B-cell lymphoma was diagnosed. She was treated with radiation therapy without response and died. There are few reports of erythematosus systemic lupus associated with primary central nervous system lymphoma.

  9. Criopreservação de formas de cultura do Trypanosoma cruzi Cryopreservation of Trypanosoma cruzi culture form

    Directory of Open Access Journals (Sweden)

    Lúcia Maria C. Galvão

    1981-09-01

    Full Text Available Formas de cultura de diferentes cepas do T.cruzi foram submetidas a vários processos de criopreservação. As percentagens de recuperação, avaliadas pela motilidade dos parasitas, foram consideradas como adequadas com algumas das técnicas empregadas, variando entre 60 a 80%. A estabilidade das características biológicas do material criopreservado foi investigada através do estudo das curvas de crescimento e diferenciação em meio acelular, infectividade para celulas de cultura de tecido ("Vero", diferenciação intracelular em cultura de tecido assim como infectividade e curso da infecção em animais de laboratório. De um modo geral essas características nao foram significativamente alteradas no material congelado e estocado por diferentes períodos de tempo.A systematic study of the cryopreservation of T. cruzi culture forms was per formed using different parasite strains and freezing methods. The recovery rates with some of the methods as evaluated by motility of the thawed parasites were fairly high (60-80%. The following aspects have been used to investigate the stability of the parasites' biological characteristics atter cryopreservation: growth and differentiation in acelular medium, infectivity to tissue culture "Vero" cells, intracellular differentiation and infectivity to animals. Those characteristics had not been significantly changed by the cryopreservation procedures.

  10. Algumas investigações sobre Schizotrypanum de Quirópteros

    Directory of Open Access Journals (Sweden)

    Emmanuel Dias

    1939-01-01

    Full Text Available Os autores referem as especies de morcegos de diversos países americanos, emque foi pesquisada no sangue a presença de hemoflagelados. Tripanosomas com a morfologia das formas sanguicolas de Schizotrypanum foram encontrados, tendo sido colhidos dados novos sobre a distribuição geografica e a incidencia da infecção em diferentes especies de morcegos. Sómente nos tecidos do Phyllostomus hastatus puderam ser encontradas as formas de multiplicação do flagelado. Alimentando-se exemplares de Triatoma infestans em Eumops bonariensis beckeri infectado, foi obtido desenvolvimento intestinal do parasito. Por inoculação das vinchucas assim infectadas em camondongo, conseguiu-se facilmente transmissão da infecção a este animal. Inoculando-se cultura do Schizotrypanum de Phyllostomus hastatus em coelho, por via subcutanea, verificaram-se no ponto de inoculação, 5 dias depois, celulas contendo tipicas formas de leishmania. São assinalados fatos observados sobre a associação demorcegos com Hemipteros sugadores (Reduvideos e Cimicideos, os quais, pela circunstancia de se poderem infectar pelo flagelado, são os possiveis transmissores da infecção a estes mamiferos.

  11. Modeling and simulation of PEM fuel cell's flow channels using CFD techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Edgar F.; Andrade, Alexandre B.; Robalinho, Eric; Bejarano, Martha L.M.; Linardi, Marcelo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: efcunha@ipen.br; abodart@ipen.br; eric@ipen.br; mmora@ipen.br; mlinardi@ipen.br; Cekinski, Efraim [Instituto de Pesquisas Tecnologicas (IPT-SP), Sao Paulo, SP (Brazil)]. E-mail: cekinski@ipt.br

    2007-07-01

    Fuel cells are one of the most important devices to obtain electrical energy from hydrogen. The Proton Exchange Membrane Fuel Cell (PEMFC) consists of two important parts: the Membrane Electrode Assembly (MEA), where the reactions occur, and the flow field plates. The plates have many functions in a fuel cell: distribute reactant gases (hydrogen and air or oxygen), conduct electrical current, remove heat and water from the electrodes and make the cell robust. The cost of the bipolar plates corresponds up to 45% of the total stack costs. The Computational Fluid Dynamic (CFD) is a very useful tool to simulate hydrogen and oxygen gases flow channels, to reduce the costs of bipolar plates production and to optimize mass transport. Two types of flow channels were studied. The first type was a commercial plate by ELECTROCELL and the other was entirely projected at Programa de Celula a Combustivel (IPEN/CNEN-SP) and the experimental data were compared with modelling results. Optimum values for each set of variables were obtained and the models verification was carried out in order to show the feasibility of this technique to improve fuel cell efficiency. (author)

  12. [Advances in the management of neonatal hypoxia].

    Science.gov (United States)

    Riesgo, Rudimar dos Santos; Becker, Michele M; Ranzan, Josiane; Winckler, Maria Isabel B; Ohlweiler, Lygia

    2013-09-01

    Introduccion. Durante el nacimiento, ocurren cambios fisiologicos en practicamente todos los organos del niño, incluyendo el sistema nervioso central. En esta fase de transicion, es posible un cierto grado de hipoxemia, en general bien tolerado por el neonato. Sin embargo, si la hipoxia neonatal es muy intensa y continuada, puede instalarse una encefalopatia neonatal, lo que caracteriza una situacion critica para el recien nacido. Su abordaje adecuado es imprescindible para garantizar un buen pronostico a largo plazo. Desarrollo. Se actualizan las informaciones acerca de la hipoxia neonatal y se revisan publicaciones recientes acerca de los avances en su abordaje a traves de la medicina basada en evidencias. Conclusiones. La encefalopatia neonatal se puede clasificar desde el punto de vista clinico en tres niveles de intensidad. Usualmente, los casos leves tienen un buen pronostico, los casos de intensidad moderada tienen un 30% de posibilidad de secuelas y los de intensidad grave tienen mas del 70% de mortalidad, pero practicamente todos los supervivientes tendran secuelas. Los avances ocurrieron en dos areas: en el diagnostico, con nuevas tecnicas de EEG y RM, y en el tratamiento, con la aparicion de la hipotermia terapeutica. Existe la posibilidad de un uso futuro para la terapia con celulas madre. El pronostico depende de la clasificacion clinica, de los datos de neuroimagen y del EEG.

  13. [Neurological disorders and the blood-brain barrier. Strategies and limitations for drug delivery to the brain].

    Science.gov (United States)

    Domínguez, Alazne; Álvarez, Antonia; Suárez-Merino, Blanca; Goñi-de-Cerio, Felipe

    2014-03-01

    Introduccion. La incidencia de enfermedades del sistema nervioso central (SNC) aumenta a causa del envejecimiento de la sociedad. Desgraciadamente, los tratamientos clasicos para tratarlas no resultan efectivos debido a la presencia de la barrera hematoencefalica. Objetivo. Abordar las propiedades de la barrera hematoencefalica que impiden el transporte de los farmacos al cerebro y las principales estrategias para tratar las afecciones neurologicas. Desarrollo. La barrera hematoencefalica esta compuesta principalmente por un endotelio vascular especializado y las celulas de la glia. Esta constituye una herramienta a disposicion del organismo para aislar al SNC del resto del cuerpo. Sin embargo, tambien supone un impedimento para que muchos farmacos alcancen su diana en el cerebro. Conclusiones. Para poder tratar las afecciones neurologicas, los farmacos deben ser capaces de alcanzar el cerebro. Los agentes terapeuticos pueden diseñarse para que sean capaces de atravesar esta barrera, o bien facilitar su entrada mediante el uso de sistemas de liberacion. Para evaluar la efectividad de los tratamientos dirigidos a enfermedades del SNC, se emplean los modelos animales de enfermedades neurologicas asi como modelos in vitro de barrera hematoencefalica.

  14. Leucemia Mielóide Crônica: transplante de medula óssea Cronic Myeloid Leukemia: bone marrow transplantation

    Directory of Open Access Journals (Sweden)

    Francisco J. P. Aranha

    2008-04-01

    Full Text Available A única terapia curativa para Leucemia Mielóide Crônica ainda é o transplante de células hematopoéticas progenitoras (TCHP; os atuais resultados com uso do imatinibe são suficientes para indicarmos o TCHP como um tratamento de segunda ou terceira linha. A decisão de realizar TCHP existe em uma variedade de momentos: falha em se conseguir remissão hemtológica, citogenética ou molecular, ou quando se perde a melhor resposta conseguida ou por progressão da doença para uma fase avançada. Há decisão também de como transplantar. Nesta revisão apontamos algumas destas decisões e as atuais controvérsias.Although the only curative therapy for chronic myeloid leukemia remains allogeneic stem cell transplantation (allo-SCT, the results of imatinib in newly diagnosed patients are sufficiently impressive to have displaced allo-SCT to second or third-line treatment. Patients now arrive at a decision for transplantation in a variety of disease situations: failing to achieve certain hematological, cytogenetic and molecular remission by some pre-determined timepoint, having lost a previous best response or due to progression to an advanced phase. The decision is also how to transplant. In this review article, the evidence supporting some of these decisions and current controversies are discussed.

  15. Caracterização da tuberculose multidroga resistente durante a gravidez, em Campinas, Estado de São Paulo, Brasil, no período de 1995 a 2007

    Directory of Open Access Journals (Sweden)

    Helenice Bosco de Oliveira

    2011-10-01

    Full Text Available INTRODUÇÃO: Foi feito um acompanhamento das gestantes tratadas para tuberculose multidroga resistente (TB-MDR durante a gravidez, em Campinas, Estado de São Paulo, no período de 1995 a 2007. MÉTODOS: No estudo retrospectivo, foram incluídas pacientes com cepa resistente, pelo menos à isoniazida e à rifampicina e gravidez em qualquer momento, durante o tratamento. Os casos receberam esquema individualizado baseado nos padrões de resistência medicamentosa e nos antecedentes de tratamento de cada paciente. RESULTADOS: Sete gestantes apresentaram resistência a duas ou mais drogas. Três já estavam grávidas, antes do início do tratamento e quatro engravidaram depois. Duas estavam com Aids, uma foi a óbito e em outra ocorreu falência de tratamento. Todas apresentaram tuberculose avançada com achados radiológicos graves e para cinco pacientes o tempo médio da conversão do escarro foi de quatro meses. Duas gestantes foram curadas. Dois recém-nascidos foram infectados com o HIV por suas progenitoras. CONCLUSÕES: O resultado do tratamento foi insatisfatório e a supervisão direta é imperativa na TB-MDR durante a gestação. O planejamento familiar deve ser fortemente recomendado.

  16. Radio Observations of SNR Environments

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    Estela M. Reynoso

    2007-01-01

    Full Text Available Se calcula que la mayor a de los remanentes de supernovas (RSNs en nuestra galaxia se encuentran muy cerca o dentro de las nubes moleculares en las que nacieron sus estrellas progenitoras. Cuando un RSN interact ua con nubes interestelares, no s olo se altera la morfolog a y la evoluci on del RSN sino que tambi en las nubes se calientan, se comprimen, se disocian, o sufren modi caciones en su qu mica. La turbulencia que se genera en las nubes moleculares puede desencadenar formaci on estelar. El estudio de la emisi on en radio en l neas at omicas y moleculares proveniente de RSNs aporta informaci on fundamental para describir el ambiente en el cual evoluciona un RSN y determinar posibles sitios de interacci on RSN-nube interestelar. La detecci on de m asers de OH en la l nea sat elite de 1720 MHz permite acotar tanto las caracter sticas del medio ambiente chocado como de la din amica del frente de choque del RSN. En este art culo presento una recopilaci on de distintos resultados obtenidos a partir de observaciones en radio en diferentes l neas espectrales y bajo distintas condiciones en direcci on a algunos RSNs y sus entornos

  17. Mielolipoma hepático en una hernia diafragmática peritoneo-pericárdica en un gato: Reporte de caso

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    C Beato

    2013-01-01

    Full Text Available Se presenta un gato de 10,5 años de edad con anorexia repentina y disnea. Al examen ultrasonográfico de tórax se detectó una masa que comprimía el corazón en el lado derecho. A la necropsia se observó una hernia diafragmática peritoneo pericárdica, misma que contenía segmentos de omento e hígado atrapados dentro del saco pericárdico. Al análisis microscópico, se observó un tejido de neoformación en el segmento de hígado herniado, el cual presentaba un gran número de adipocitos, megacariocitos y células progenitoras mieloides y eritroides, además de pequeños fragmentos óseos. La hernia diafragmática peritoneo pericárdica con atrapamiento hepático es un defecto congénito generalmente asintomático en gatos. Su hallazgo suele ser incidental, y se ha observado que generalmente se asocia al mielolipoma hepático en felinos.

  18. Normal development of fetal hepatic haematopoiesis during the second trimester of gestation is upregulated by fibronectin expression in the stromal cells of the portal triads El desarrollo normal de la hematopoyesis hepática fetal durante el segundo trimestre de embarazo está regulado al alza por la expresión de fibronectina en las células del estroma de las tríadas portales

    Directory of Open Access Journals (Sweden)

    D. Tamiolakis

    2007-10-01

    -renovación, la proliferación y el crecimiento de las células madre hematopoyéticas, al interactuar con las células progenitoras hematopoyéticas. Se sabe que las glucoproteínas de la MEC producidas por las células del estroma desempeñan un papel crítico en la regulación del crecimiento y la diferenciación celulares. Se han documentado numerosos factores solubles y de membrana que regulan directamente la hematopoyesis, pero se sabe poco de la actividad de las células del estroma hepático y de la proteína (fibronectina de la matriz extracelular en el feto en relación con la hematopoyesis hepática. La unión de las células eritroides tardías a la fibronectina está bien tipificada y se cree que es crítica para las etapas terminales de la diferenciación eritroide. La intención de este artículo es determinar el papel de la fibronectina en la proliferación y diferenciación hematopoyética del hígado fetal en las distintas etapas del desarrollo. Material y método: examinamos y comparamos la expresión inmunohistoquímica de fibronectina en los campos portales del estroma hepático durante los trimestres primero, segundo y tercero del embarazo en relación con la aparición de células progenitoras hematopoyéticas CD34, progenitoras del estroma y endoteliales vasculares, respectivamente. Resultados: nuestros resultados mostraron una diferencia cuantitativa en cuanto a expresión de fibronectina en el estroma del tejido conjuntivo de los campos portales en el segundo trimestre de embarazo respecto al primero (p < 0,0001, prueba de la t y respecto al tercero (p < 0,0001, prueba de la t. Se hallaron también cambios similares en cuanto a la expresión de CD34 respecto al primer (p < 0,0001, prueba de la t y el tercer trimestres (p < 0,0001, prueba de la t, lo que indica la participación directa de la fibronectina en el mantenimiento de la actividad hematopoyética. Conclusiones: nuestros datos aportan pruebas de que un componente de la glucoproteina de la MEC, la

  19. Restauración del tejido gingival a partir de fibroblastos autólogos

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    Eduvigis Solórzano N

    2013-12-01

    Full Text Available El interés de la investigación básica biomédica ha tenido un crecimiento vertiginoso en los últimos años y la odontología no escapa a esta motivación, es así como estamos en la búsqueda de alternativas de tratamiento a defectos de tejidos blandos y óseos que permitan resultados satisfactorios a nuestros pacientes desde el punto de vista estético y funcional, ya que en ocasiones, las limitaciones en la cantidad de tejido disponible para autoinjerto no permiten el éxito esperado, es por ello que la interdisciplinariedad ha permitido la exploración de nuevas fuentes de tejido bucal. Las investigaciones actuales se enfocan en el desarrollo y caracterización de tejidos equivalentes a la mucosa bucal y se ha demostrado que los fibroblastos del conectivo gingival participan eficientemente en la reparación de los tejidos, razón por la cual se están utilizando con mucho éxito en medicina regenerativa; así como también el aislamiento de células progenitoras mesenquimáticas a partir de diversos tejidos bucales, entre ellos el más utilizado, la pulpa dental.

  20. Testing common envelope theories with white dwarf Binaries

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    G. Nelemans

    2004-01-01

    Full Text Available Determinamos las posibles masas y radios de las progenitoras de enanas blancas en binarias a partir de ajustes a modelos evolutivos estelares detallados y los utilizamos para reconstruir la fase de transferencia de masa durante la cual se form o la enana blanca. Con rmamos lo encontrado anteriormente: que en la primera fase de transferencia de masa, en la evoluci on binaria que condujo a la formaci on de un par cercano de enanas blancas, el formalismo est andar de una envolvente com un que se basa en el equilibrio de energ a simplemente no se aplica. Lo que puede explicar las observaciones es un formalismo con base en equilibrio del momento angular. Nuestro an alisis se extendi o a todas las binarias cercanas en las que al menos una componente es enana blanca. Al comparar los dos mostramos que el formalismo con base en el equilibrio del momento angular puede explicar todas las observaciones por lo menos tan bien como el formalismo de energ a.

  1. Papel das citocinas na imunopatogênese da doença do enxerto contra o hospedeiro Role of cytokines in the immunopathogenesis of Graft-versus-Host Disease

    Directory of Open Access Journals (Sweden)

    Silvana L. Vizoni

    2008-04-01

    Full Text Available O transplante de células progenitoras hematopoéticas é o tratamento de escolha para muitas doenças hematológicas e imunodeficiências primárias. A doença do enxerto contra o hospedeiro (DECH é ainda uma grave complicação após o transplante alogênico e a principal causa de mortalidade e morbidade. O estudo da patogênese da DECH auxilia no desenvolvimento de medidas preventivas da doença, assim como na escolha de terapias imunossupressoras adequadas de tratamento. Este estudo discute os principais componentes imunológicos envolvidos na patogênese da DECH aguda e crônica, com ênfase à participação das citocinas e seu controle.Stem cell transplantation is the first line treatment of many hematological diseases and primary immunodeficiencies. Graft-versus-host disease (GVHD is still a severe complication after allogeneic transplantation and the main cause of mortality and morbidity. The study of the pathogenesis of GVHD may help to develop ways to prevent the disease, as well as to choose adequate immunosuppressant therapies. This study discusses the main immunological components involved in the pathogenesis of acute and chronic GVHD, with emphasis on the participation of cytokines and their control.

  2. STUDYING THE PROPERTIES OF MASSIVE GALAXIES IN PROTOCLUSTERS USING MILLIMETRE-WAVELENGTH OBSERVATIONS

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    M. Zeballos

    2011-01-01

    Full Text Available Presentamos un análisis de densidad y distribución espacial de la población de fuentes milimétricas (MMGs hacia 17 galaxias activas a altos corrimientos al rojo usando observaciones a 1.1 mm tomadas con la cámara AzTEC en los telescopios ASTE (Atacama Submillimeter Telescope Experiment y JCMT (James Clerk Maxwell Telescope. La muestra nos permite estudiar las propiedades de las MMGs en ambientes protocumulares (sesgados y compararlas con la población de campos blancos (sin sesgo. El objetivo es identificar si estos ambientes sesgados son responsables de las diferencias en el número y distribución de galaxias oscurecidas por polvo, y averiguar si estos cambios apoyan la sugerencia de que las MMGs pueden ser las progenitoras de las galaxias (elípticas masivas que vemos hoy en día en el centro de los cúmulos más ricos.

  3. Felipa de Lancáster, la dama inglesa que fue modelo de reginalidad en Portugal (1387-1415

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    Santos Silva, Manuela

    2016-06-01

    Full Text Available Until a few decades ago, the historians’ interest in the evaluation of the power exercised by the queens, as wives or mothers of the kings who were in charge of the governance of the kingdom, was almost non-existent. However, there are enough data to prove that in Portugal, in the Middle Ages, some queens exerted political and diplomatic functions, participated with their husbands in the administration of the assets of the crown, in addition to fulfilling the obvious obligations of being good wives and mothers. Philippa of Lancaster’s –wife of John I of Portugal– queenship is well documented.Hasta hace algunas décadas, el interés mostrado por los historiadores en evaluar el poder ejercido por las reinas portuguesas como consortes o progenitoras de los reyes era casi inexistente. Se conservan, sin embargo, suficientes datos como para poder afirmar que, en la Edad Media portuguesa, algunas reinas ejercieron funciones de naturaleza política y diplomática, y participaron junto a sus maridos en la administración de los bienes de la corona, además de cumplir con los deberes que se les atribuían como esposas y madres. Uno de los casos mejor documentados es el de Felipa de Lancáster, esposa de Juan I de Portugal, a quien llamaremos João I para evitar confusiones causadas por homonimias.

  4. Opinião do pai sobre o aleitamento materno

    Directory of Open Access Journals (Sweden)

    ROSINEIDE SANTANA DE BRITO

    2006-01-01

    Full Text Available Estudio cualitativo desarrollado en Natal/RN con 13 hombres cuyos hijos estaban en período de lactancia natural. Tuvo por objetivo verificar la opinión del padre sobre la lactancia materna. Los datos se obtuvieron a partir de entrevista parcialmente estructurada y tratados siguiendo la técnica de análisis temático propuesta por Bardin. Los padres atribuyeron valores importantes a la lactancia relacionándolos al hijoya la compañera. Con relación al niño, verificamos conocimiento acerca de los beneficios de la leche materna como un alimento nutritivo, que promueve el crecimiento JI desarrollo infantil, determina la salud actual y favorece la vinculación entre el niño JI su madre. Con relación a la compañera, los entrevistados dijeron que la lactancia materna contribuye para que se estable el vínculo afectivo zca entre lactante y progenitora, como también, para la realización de la maternidad. Por consiguiente, afirmamos que los padres expusieron opiniones positivas acerca de la lactancia materna, las cuales pueden favorecer la promoción JI contribuirpara el suceso de la lactancia materna.

  5. Els mercaders catalans i la cultura, de l'edat mitjana al renaixement

    OpenAIRE

    Aurell, J; Rubiés, J.P. (Joan-Pau)

    1993-01-01

    El estudio de los mercaderes medievales a menudo ha sufrido una distorsión derivada de la imagen de los agentes económicos precapitalistas cuyo comportamiento es inspirado por valores culturales típicamente burgueses. Sobre la base de una definición más rigurosa de este grupo social, este artículo utiliza el caso de la Barcelona medieval con el fin de desarrollar una hipótesis sobre la evolución de los comerciantes a lo largo de la crisis de la Baja Edad Media y el comienzo del Renacimiento. ...

  6. El clima laboral en cuestión. Revisión bibliográfico-descriptiva y aproximación a un modelo explicativo multivariable

    OpenAIRE

    Ángel José Olaz Capitán

    2013-01-01

    Tras examinar diferentes modelos desarrollados en los últimos cincuenta años, este trabajo propone un modelo explicativo de Clima Laboral en organizaciones complejas. Dicho modelo plantea nuevas conexiones entre escenarios y variables explicativas con objeto de evidenciar los síntomas de deterioro más significativos, posibles vías de análisis, así como el estudio de las repercusiones derivadas en el individuo, grupo y organización, siempre con el objeto de introducir buenas prácticas conducen...

  7. Criminalidad, inseguridad pública y comportamiento de los electores: un análisis del proceso electoral estatal 2010 en Ciudad Juárez, Chihuahua

    OpenAIRE

    Andrés Valdez Zepeda; Abraham Paniagua Vázquez

    2011-01-01

    En este escrito se hace un análisis del efecto de la crisis de inseguridad pública derivada de la llamada guerra contra el narcotráfico en la conducta del votante en un momento electoral, a la luz de las diferentes teorías sobre el voto. Se describe en lo particular el efecto de la actual crisis de inseguridad pública en los resultados de las elecciones locales del 2010 en Ciudad Juárez, Chihuahua, México. Se concluye que una crisis de inseguridad y violencia orienta el comportamiento elect...

  8. Cistos esplênicos não-parasitários

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    Luis Alberto Schlittler

    2010-12-01

    Full Text Available Este artigo apresenta uma revisão geral do tema, com ênfase em conceitos atuais e no manejo das situações clínicas em questão, em especial a conceitos referentes ao tratamento. Também é feita uma revisão extensa quanto à etiologia e seguimento dos pacientes com cisto esplênico não parasitário. São citadas informações derivadas dos principais estudos clínicos publicados na literatura médica atual.

  9. Psicofarmacogenética: uma nova abordagem terapêutica

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    Vallada Filho Homero Pinto

    1999-01-01

    Full Text Available A psicofarmacogenética é uma nova área de investigação derivada da psicofarmacologia e da genética. Esta disciplina procura identificar genes de suscetibilidade associados a diferentes padrões de resposta terapêutica e/ou ao variado grau de efeitos colaterais dos psicofármacos. O presente artigo discorrerá, após um breve histórico, sobre alguns exemplos de variantes genéticas relacionadas com a resposta terapêutica de antipsicóticos e antidepressivos.

  10. Plan de educación al debut diabético tipo 1 en el contexto de ingreso hospitalario

    OpenAIRE

    Linares Muela, Marta

    2015-01-01

    La diabetes mellitus tipo 1 (DM1) es una enfermedad crónica de origen autoinmune, suele debutar en la infancia, su incidencia sigue en aumento y las complicaciones derivadas de un cuidado incorrecto supone graves problemas de salud para aquellos que la padecen. Para el 2030 se prevé que sea la 7º causa de mortalidad a nivel mundial. La educación para la salud con esta clase de pacientes es fundamental para proporcionar las herramientas necesarias para alcanzar al nivel de autocuidado que u...

  11. Páncreas : cuidados en la Diabetes Mellitus

    OpenAIRE

    Leiva Idígoras, Raquel

    2014-01-01

    La diabetes es una enfermedad crónica que afecta a unos 347 millones de personas en el mundo. Esta cifra va en aumento y supone un gran coste para la sanidad que puede ser evitado, ya que es una patología, sobre todo la tipo 2, que depende en gran parte de unos hábitos de vida incorrectos. Los profesionales de la salud tienen un papel fundamental a través de la educación para evitar las complicaciones derivadas de la diabetes. El páncreas es una glándula que cuenta con dos porciones una exocr...

  12. El estrés calórico en vacas lecheras

    OpenAIRE

    Callejo Ramos, Antonio

    2015-01-01

    En las vacas lecheras el exceso de calor provoca cuantiosas pérdidas económicas debido a sus consecuencias sobre la producción y la reproducción, derivadas de los efectos negativos que tiene en el metabolismo digestivo, el sistema inmune, el sistema endocrino y el propio comportamiento de estos animales. Por tanto, es imprescindible adoptar medidas de diversa naturaleza tanto para reducir la producción de calor de las vacas como para incrementar su tasa de ...

  13. El estómago como un órgano endocrino: Mecanismos gástricos implicados en la regulación de la ingesta y el balance energético

    OpenAIRE

    López Senín, Lucía

    2014-01-01

    La obesidad es una enfermedad multifactorial cuya prevalencia ha aumentado exponencialmente en los últimos años hasta alcanzar proporciones pandémicas. La cirugía bariátrica constituye actualmente el único tratamiento efectivo contra la obesidad, sugiriendo que las señales derivadas del tracto gastrointestinal son cruciales en la regulación del balance energético. El presente proyecto se basa en la hipótesis de que el estómago coordina y procesa factores externos, sensoriales y nutricionales....

  14. Una inscripción de Senaquerib en la Real Academia de la Historia

    OpenAIRE

    Molina Martos, Manuel

    2000-01-01

    [ES] La Real Academia de la Historia conserva en los fondos de su Gabincte de Antigüedades una inscripción del rey asirio Senaquerib (704-681 a.c.) procedente de su palacio de Ninive. Algunas inexactitudes en las ediciones del texto de J. F. Riaño (1895) y de J. M. Penuela (1966); nuevas informaciones derivadas de los trabajos de catalogación del mencionado Gabinete de Antigüedades, así como la publicación dc recientes e importantes obras acerca de la epigrafía y las esculturas...

  15. Estudio teórico y experimental de la reactividad química bajo irradiación microondas: aplicación a 1,2,3 – triazoles

    OpenAIRE

    Cózar Ruano, Abel de

    2008-01-01

    El trabajo que se describe en la presente memoria para optar al grado De doctor europeo en ciencias químicas puede dividirse en dos partes Claramente diferenciadas, una experimental y otra teórica. En la primera parte del trabajo se ha realizado un amplio estudio de la Reactividad de derivados de 1,2,3-triazol, unidad estructural poco estudiada que está cobrando gran importancia en los últimos años debido las interesantes Propiedades derivadas de su estructura. El objetivo se c...

  16. Síntesis estereoselectiva de amidas glicídicas vía una nueva clase de sales de sulfonio quirales: aplicaciones en síntesis de productos naturales

    OpenAIRE

    Vivar García, Carlos

    2014-01-01

    En esta tesis se explora una nueva metodología de síntesis asimétrica de epóxidos mediante el uso de una nueva clase de sales de sulfonio quirales derivadas de aminoácidos y caracterizadas por una estructura bicíclica. Las reacciones de estas sales con aldehidos rindieron de forma eficaz y con una elevada estereoselectividad epoxi amidas, también llamadas amidas glicídicas. Esta metodología probó ser de utilidad para una amplia gama de aldehidos que incluyeron aldehidos aromáticos, alifáticos...

  17. BINAM-prolinamidas: nuevos organocatalizadores quirales en reacciones aldólicas

    OpenAIRE

    Hita López, María del Carmen

    2007-01-01

    En la presente memoria se describe la síntesis y aplicaciones de nuevos organocatalizadores derivados de B1NAM y prolina en reacciones aldólicas. Se ha puesto a punto la síntesis de las diferentes prolinamidas derivadas de BINAM y prolina, discutiendo su estructura, relación entre ellas, así como su recuperación. Se ha estudiado la actividad catalítica de los nuevos catalizadores BINAM-prolinamidas en condensación aldólica directa entre aldehidos y cetonas alifáticas, en diferentes disolvente...

  18. Experiencia de implementación de un modelo de atención primaria

    OpenAIRE

    Ruíz Rodríguez, Myriam; Acosta Ramírez, Naydú; Rodríguez Villamizar, Laura Andrea; Uribe Rivero, Luz Marina; León Franco, Martha Helena

    2012-01-01

    Objetivo Identificar las dificultades y los factores dinamizadores en la implementación de un modelo de atención primaria en Santander en la última década.Métodos Estudio cualitativo con un enfoque de pluralismo y la triangulación de fuentes y actores, con análisis de crítica del límite y de los valores de los juicios (Boundary critique).  Resultados Según las categorías emergentes derivadas de la apropiación de los atributos del modelo se encuentran problemáticas tanto en aspectos filosófico...

  19. As Carreiras no Serviço Público Federal Brasileiro: Breve Retrospecto e Perspectivas

    OpenAIRE

    Dias, Ronaldo

    2010-01-01

    As formas como se definem as carreiras e cargos públicos, no Brasil e nos demais países, são derivadas das concepções acerca do Estado e de seu papel em determinado momento histórico. Este estudo procurará levantar o estado da arte das carreiras e cargos públicos no serviço público federal brasileiro, particularmente no Poder Executivo, suas determinantes históricas, as discussões que permeiam a determinação das carreiras, e as práticas extremamente diversas utilizadas nestes setores, ao long...

  20. Historia del paramilitarismo en Colombia History of the paramilitarismo in Colombia

    OpenAIRE

    Edgar de Jesús Velásquez Rivera

    2007-01-01

    En Colombia, desde la década de los años ochenta del siglo XX tomó fuerza el paramilitarismo como estrategia contrainsurgente, política que no ha sido reconocida como tal por parte de los distintos gobiernos y se expresa como terrorismo de Estado. Incidió en el surgimiento de tal fenómeno, la ideología anticomunista que profesan la mayoría de miembros de las fuerzas armadas, la cultura política derivada de la violencia, la corrupción y el clientelismo, así como el narcotráfico, al igual que l...

  1. Rehabilitación neuropsicológica en un caso de afasia motora aferente

    OpenAIRE

    Gilberto Manuel Galindo Aldana; Héctor Pelayo González; Yulia Solovieva; Luis Quintanar Rojas

    2014-01-01

    Objetivo. Las alteraciones derivadas del daño cerebral, como los síndromes afásicos, pueden desencadenar disfunciones en diferentes niveles de la actividad del paciente. La neuropsicología de Luria ha sido la disciplina dedicada a la caracterización funcional y al análisis rehabilitatorio de los síndromes afásicos. Con frecuencia, a este análisis se incorporan datos recogidos con técnicas neurolingüísticas y de neuroimagen (TAC, fMRI). Presentar un método de rehabilitación que, basado en los ...

  2. Campo de dirección. Método de las isoclinas, en la solución de ecuaciones diferenciales de primer orden

    OpenAIRE

    Castañeda, Pedro; Quintero, Arely; Moreno, Aura Matilde

    2007-01-01

    En la descripción del proceso de modelado se habla acerca de formular un modelo matemático de un problema del mundo real a través de un razonamiento intuitivo acerca del mismo o a partir de leyes físicas basadas en la evidencia proveniente de la experimentación. El modelo matemático a menudo toma la forma de una ecuación diferencial, es decir, una ecuación que contiene una función desconocida y algunas de sus derivadas.

  3. Visual analysis of gene expression data by means of biclustering

    OpenAIRE

    Santamaría Vicente, Rodrigo

    2010-01-01

    [ES] La bioinformática es un área de investigación que maneja grandes colecciones de datos. Un ejemplo importante es el análisis de la expresión genética mediante microarrays, donde están involucradas no sólo las grandes matrices de expresión derivadas de experimentos con microarrays, sino también los complejos resultados de su análisis y la cantidad de fuentes externas de conocimiento que se pueden utilizar para confirmar o validar los resultados del experimento. Esta cantidad de información...

  4. Projecto de carneiro hidráulico com integração de energia eléctrica proveniente de fonte renovável

    OpenAIRE

    Mota, Miguel Ângelo Diego Lisboa Medeiros

    2015-01-01

    A água é um bem essencial para toda a humanidade e a sua disponibilidade está condicionada pelo seu transporte desde os pontos de captação. O seu transporte pode ser efectuado com taludes naturais por gravidade ou recorrendo a bombas, que consomem energia eléctrica ou derivada do petróleo. A energia proveniente da queima de combustíveis fósseis contribui para a deterioração do meio-ambiente aumentando o efeito de estufa. Assim, a crescente preocupação com os impactos ambientais que advêm da s...

  5. El plan estratégico de comunicación. Estructura y funciones

    OpenAIRE

    Tur-Viñes, Victoria; Monserrat-Gauchi, Juan

    2014-01-01

    Presentamos una revisión de la práctica comunicativa actual. Reflejamos la evolución de la comunicación tradicional como herramienta del marketing mix a la comunicación integrada de marketing y luego al marketing estratégico, presentando los principales modelos teóricos explicativos. El objetivo es analizar las implicaciones derivadas de la comunicación estratégica y su dependencia de la investigación y la planificación. Se recogen las principales iniciativas existentes que contribuyen a cont...

  6. Fracturas de columna toraco-lumbar: Complicaciones de la vía anterior

    OpenAIRE

    Navarrete Faubel, Francisco Enrique; Escribá Roca, Ismael; Pérez-Millán, L. A.

    2000-01-01

    Objetivo: Analizar las complicaciones de las fracturas torazo-lumbares tratadas mediante abordaje anterior, derivadas de la misma vía de abordaje, de la técnica de descompresión o de la estabilización propiamente dicha. Pacientes: Durante un periodo de 10 años (1983-1993), se realizaron 39 abordajes anteriores para el tratamiento de las fracturas del tránsito torazo-lumbar. Los pacientes presentaban clínica neurológica parcial. Todos los casos tuvieron un seguimiento mínimo de 5 años. R...

  7. Identificación del perfil competencial docente en educación superior. Evidencias para la elaboración de programas de formación continua del profesorado universitario

    OpenAIRE

    Triado, Xavier; Estebanell, Meritxell; Marquez Cebrian, Maria Dolores; Corral Manuel de Villena, Ignacio de

    2014-01-01

    Este artículo aporta evidencias y reflexiones sobre las necesidades formativas, en el ámbito de las competencias docentes del profesorado universitario. La finalidad es buscar líneas comunes para orientar, de una manera adecuada y focalizada, los planes de formación del profesorado universitario en cuanto a competencias docentes, y necesidades formativas derivadas. Desde el año 2010 las ocho universidades públicas catalanas investigan conjuntamente acerca de la identificación del perfil c...

  8. Enfoque por competencias: Problemáticas didácticas que enfrentan el profesorado

    OpenAIRE

    Blanca Isela Robles-Haros; Etty Haydeé Estévez-Nenninger

    2016-01-01

    Recibido 4 de setiembre de 2015 • Corregido 17 de octubre de 2015 • Aceptado 17 de noviembre de 2015El presente ensayo tiene como objetivo analizar el enfoque por competencias y la problemática derivada de las políticas educativas que han buscado que el profesorado de educación superior en México enseñe siguiendo modelos didácticos basados en dicho enfoque; asimismo, se revisan los programas que promovieron de inicio las competencias en el mundo, así como algunas posturas críticas respecto de...

  9. Obtención de células madre de la pulpa dental : caracterización y adaptación a diversas condiciones de oxígeno

    OpenAIRE

    El Alami, Marya

    2013-01-01

    Uno de los retos actuales de las cirugías odontológicas es la regeneración ósea, especialmente del hueso alveolar para la realización del implante dental. En los últimos años, las células madre mesenquimales derivadas la pulpa dental (CMPDs), se han convertido en un objetivo de estudio prometedor para la regeneración ósea gracias a su potencial de diferenciación a odontoblastos y osteoblastos así como sus propiedades inmunológicas. Sin embargo, su aplicación sigue siendo limitada por el gran ...

  10. Metodología sobre obtención de muestra, cultivo y caracterización in vitro de células madre mesenquimales humanas obtenidas de la pulpa de dientes permanentes. Revisión narrativa de la literatura

    OpenAIRE

    Perdomo Díaz, Alexandra

    2014-01-01

    La tendencia actual en la ingeniería de tejidos es el empleo de las células madre mesenquimales (MSCs) aisladas de tejidos adultos, hay un gran interés en el uso de células madre de la pulpa dental (DPSCs) para la regeneración del tejido dental. Por ello, el propósito de este estudio fue realizar una revisión narrativa de la literatura científica disponible para la obtención de muestra, aislamiento y caracterización in vitro de células madre (SCs) mesenquimales derivadas de la ...

  11. Análisis del maíz forrajero por NIRS: variaciones en la predicción según tratamiento matemático de los datos espectrales

    OpenAIRE

    Roza, M.B. (María); A Martínez; O. Fernández; Santos, Begoña; Modroño, S.

    2012-01-01

    Con objeto de determinar la calidad y valor nutritivo de diferentes variedades de maíz forrajero, con una analítica rápida, precisa y económica, se ha estudiado el efecto del pretratamiento de los datos espectrales (ninguno, SNVD y WMSC) y derivadas (0, 1, 2 y 3) sobre los errores estándar de los modelos predictivos en el infrarrojo cercano. Para los constituyentes seleccionados (materia seca residual (MS), cenizas (CEN), proteína bruta (PB), fibra neutro detergente (FND), dige...

  12. La crisis argentina de 2000-2005: ??Inicio o consecuencia de una nueva forma de colonizaci??n?

    OpenAIRE

    Herr??iz Reyes, Jos?? Antonio

    2014-01-01

    1503 p. La conclusi??n general de la investigaci??n se configura en detalle, en los apartados siguientes, fruto de un silogismo entre las premisas derivadas de las conclusiones parciales de cada cap??tulo y sus correspondientes objetivos espec??ficos; para corroborar la hip??tesis general propuesta. Estas conclusiones presentan aportaciones para el conjunto de la Uni??n Europea y para la Rep??blica Argentina. La crisis objeto de la investigaci??n no es un fen??meno fraguado durante l...

  13. Resolución de las ecuaciones de deriva-difusión mediante un método de difusión artificial. Aplicación a dispositivos semiconductores

    OpenAIRE

    Kindelán, Ultano; de Vicente, Santiago

    1994-01-01

    En este artículo se propone un nuevo método de difusión artificial para la resolución del sistema de ecuaciones en derivadas parciales que representa el comportamiento de un dispositivo semiconductor en estado estacionario según el modelo clásico de deriva difusión. El método de difusión artificial consiste en añadir a dos de las ecuaciones del sitema términos difusivos provenientes de la discretización del problema transitorio a lo largo de las curvas características. Tras formular el sistem...

  14. Soluciones explícitas de problemas mixtos para sistemas acoplados de ecuaciones en diferencias parciales

    OpenAIRE

    L. Jódar; Legua, Matilde

    1991-01-01

    En este artículo obtenemos una solución explícita computable de problemas mixtos para sistemas acoplados de ecuaciones en diferencias parciales que aparecen al considerar aproximaciones en diferencias para sistemas acoplados en derivadas parciales. El enfoque del problema puede considerarse como un método de separación de variables discreto matricial que utilizando series de Fourier discretas permite obtener una solución explícita del problema sin tener que resolver sistemas algrabraicos line...

  15. Cálculo de frecuencias naturales en vigas elásticas, un estudio comparativo

    OpenAIRE

    Salinas Gutiérrez, Rogelio

    2003-01-01

    El estudio de vibraciones mecánicas de vigas y el conocimiento de sus frecuencias naturales de vibración han sido de sumo interés dentro del área de mecánica de estructuras. El comportamiento vibratorio de una viga al ser sometida a una o varias fuerzas puede modelarse por medio de una ecuación diferencial parcial (EDP) que involucra derivadas parciales tanto en la variable tiempo como en el espacio. La importancia de conocer las frecuencias naturales radica en que si una frecuencia de excita...

  16. Estudio de dos metodos sin malla para la resolucion de ecuaciones elipticas

    OpenAIRE

    Cuesta Molina, José Luis

    2003-01-01

    El método de diferencias finitas como método de resolución de problemas planteados en ecuaciones en derivadas parciales, es un método que ha quedado en el olvido frente a otros métodos numéricos, sobre todo frente al método de elementos finitos. Sin embargo son muchos los autores que han seguido confiando en el desarrollo del método de diferencias finitas a pesar de sus aparentes limitaciones y que han propuesto diferentes soluciones para poder aplicar las diferencias finitas a cualquier tipo...

  17. Un esquema semidiscreto de elementos finitos para el sistema "bueno" de Boussinesq

    OpenAIRE

    Díez Fernández, Honorato

    2009-01-01

    El sistema "bueno" de Boussiiiesq es un sistema de ecuaciones en derivadas parciales coi1 estructura hamiltoniana. Al discrctizarlo es de interés no perder tal estructura y en este articulo proponemos un método iluinérico de elementos finitos Petrov-Galerkiii que de origen a un sistema hamiltoniano discreto. Analizamos el error y presentamos resultados numéricos. The "good" Boussinesq systein is a system of partial differential equations with a hamiltonian structure. Wlieii carryiilg ou...

  18. Simulación de flujo transitorio en cauces naturales

    OpenAIRE

    García Navarro, Pilar; Alcrudo, Francisco

    1995-01-01

    En este trabajo se plantea la simulación matemática del flujo no estacionario en lámina libre. Ello requiere la resolución de un sistema no lineal de ecuaciones diferenciales en derivadas parciales hiperbólico que constituye la base del modelo unidimensional. Esta resolución es realizable, en el caso general, únicamente mediante técnicas numéricas que necesitan de la ayuda de ordenadores de cierta potencia y capacidad de memoria. La elaboración y desarrollo de los programas necesarios presupo...

  19. Creación de Mallas Ortogonales con Lemniscatas

    OpenAIRE

    Restrepo Arboleda, Gustavo Adolfo

    2014-01-01

    Introducción: La construcción de mallas sobre regiones irregulares ha tomado gran importancia en los últimos tiempos debido especialmente a su uso en la solución numérica de ecuaciones diferenciales parciales (EDP’s). Un método numérico comúnmente empleado es el método de las diferencias finitas. En este proceso es indispensable la construcción de una malla sobre la región en la que está definida la EDP, ya que se generan aproximaciones a los valores de las funciones y a sus derivadas parcial...

  20. Métodos numéricos para la valoración de opciones

    OpenAIRE

    Jiménez Terradillos, Vanessa

    2013-01-01

    El objetivo de este trabajo de fin de grado es dar una introducción elemental al uso de métodos en diferencias finitas para la resolución numérica de las ecuaciones en derivadas parciales que aparecen en la modelización de los derivados financieros, en particular de los contratos de opciones. La teoría moderna de las Finanzas Matemáticas se inicia con los artículos de F. Black, M. Scholes [1] y R.C. Merton [7]. Desde entonces y en paralelo con la teoría, el comercio de opci...