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Sample records for celulas progenitoras derivadas

  1. Regeneracion osea por implante de celulas madre mesenquimales derivadas de tejido adiposo humano en un modelo animal

    OpenAIRE

    Linero Segrera, Itali Marcelly

    2012-01-01

    La reconstrucción y restauración de la función esquelética continúa siendo un reto en el campo de la cirugía maxilofacial y la ortopedia. Una alternativa o terapia coadyudante a los tratamientos convencionales es la ingeniería de tejidos que surge como una posibilidad prometedora para la regeneración del tejido óseo. Con el fin de crear un modelo para la aplicación clínica de las células madre mesenquimales derivadas de tejido adiposo humano (Ad-MSCs) desarrollamos una matriz tridimensi...

  2. 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.

  3. 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

  4. LA DERIVADA SCHWARZIANA EN VARIAS VARIABLES COMPLEJAS.

    OpenAIRE

    2005-01-01

    La derivada Schwarziana ocupa un lugar importante en la teoría geométrica de funciones de una variable compleja, en problemas ligados a la univalencia y extensiones cuasiconformes, teoremas de distorsión, crecimiento, y familias linealmente invariantes, e 61p.

  5. 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

  6. 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.

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

    OpenAIRE

    Juan Virgen-Vargas; Rosalba Zepeda-Bautista; Miguel Angel Avila-Perches; Alejandro Espinosa-Calderón; José Luis Arellano-Vázquez; Alfredo Josué Gámez-Vázquez

    2014-01-01

    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-7...

  8. Acercamiento intuitivo al concepto de función derivada

    OpenAIRE

    Cortés, José Carlos

    2008-01-01

    En el siguiente artículo se propone un acercamiento numérico y gráfico al concepto de derivada y de función derivada. Para ello se propone iniciar introduciendo las ideas de diferencias, incrementos y razón de incrementos. El que esto escribe diseño y desarrollo un software de apoyo a la introducción de estas ideas. Para abordar la temática se exponen ideas teóricas, una exposición de lo propuesto en el software y algunos resultados obtenidos.

  9. La disyuntiva de Dios: ¿derivadas enteras o fraccionarias?

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    Jorge Fujioka Rojas

    2016-01-01

    Full Text Available Se presentan conceptos básicos del cálculo fraccionario. Para ello, se describe una delas primeras disyuntivas que enfrentó Dios el primer día de la creación: ¿escribiría las leyes físicasen términos de derivadas enteras o fraccionarias? Para salir de esta duda Dios examina lo quepasaría si en la segunda ley de Newton pusiera una derivada fraccionaria, en lugar de la segundaderivada usual. Dios resuelve este problema mediante la transformada de Laplace y esto lo conduceal descubrimiento de la función de Mittag-Leffler.

  10. Representaciones de la derivada de una función

    OpenAIRE

    2013-01-01

    En la actualidad dada la presencia de medios tecnológicos como las calculadoras graficadoras, que son utilizados en la enseñanza del cálculo, se hace necesario incorporar los significados visuales de la derivada, elementos que estan presentes en el discurso tradicional, sin embargo, no son significativos para el alumno ya que no los incorpora a su estructura cognitiva, ante este problema el grupo de investigación "pensamiento y lenguaje variacional", ha desarrollado métodos y teorías en un am...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Historia y epistemología de la función derivada

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    Eliseo Ramírez Rincón

    2009-10-01

    Full Text Available La historia y la epistemología de la función derivada como objeto del cálculo diferencial dan cuenta de la complejidad y de los vaivenes que en veinte siglos ha sufrido ésta, hasta adquirir el estatus de función derivada. El trabajo de cientos de seres humanos dedicados a su estudio, en distintas épocas y culturas, han hecho aportes que han permitido los cambios y el refinamiento de las ideas matemáticas de la función derivada para convertirla en un objeto (puro, aplicado y a enseñar, muy potente. Es tal la importancia de este objeto matemático que permite resolver problemas de las matemáticas, de las ciencias naturales, sociales y humanas.

  16. Un método para el cálculo de derivadas segundas

    OpenAIRE

    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...

  17. Descripción de niveles de comprension del concepto derivada.

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    Claudia Salazar Amaya

    2010-10-01

    Full Text Available Este artículo presenta un estudio de caso que describe los niveles de comprensión del concepto derivada de seis estudiantes que cursaron el espacio académico cálculo diferencial en el II semestre de 2007 en la Licenciatura en Matemáticas de la Universidad Pedagógica Nacional. El marco teórico utilizado se concentra en el desarrollo del esquema de derivada a través de tres niveles: Intra, Inter, Trans (Piaget y García, 1983, 1989. Se dedujo el nivel de comprensión alcanzado por los participantes a partir del análisis de las respuestas que dieron a diferentes problemas planteados en tres cuestionarios. Se encontró una tendencia en algunos a interpretar la derivada en términos del proceso algorítmico y también como dependencia de la expresión algebraica de la función. Por otra parte, se hicieron evidentes las dificultades para transitar de la gráfica de la función hacia la gráfica de la función derivada.

  18. 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.

  19. Hemopoietic progenitor cell identification in fetal and adult blood Célula progenitora hamatopoética - identificação em sangue fetal e de adulto

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    Aixa Müller

    2008-06-01

    Full Text Available Hemopoietic progenitor cells give rise to all cellular elements of the blood and are of importance as a potential source of cells used for correction of various pathological conditions. The main objective of this study was to identify and quantitative hemopoietic progenitor cell in antenatal fetal blood, in cord blood at the time of delivery and in adult blood, using monoclonal antibodies to surface markers and flow cytometry. CD34+ cells, most of them probably representing progenitor cells, were detected in prenatal fetal blood as early as the 17th week of gestation. The proportion of these cells showed a tendency to decrease as the pregnancy progressed. Within the population of CD34+ cells, a relatively low proportion (less than 1% were negative for the surface marker CD33 or HLA-Dr, indicating a population of primitive stem cells, i.e., progenitor cells no committed to a specific lineage. On the contrary, another group coexpressed CD33 or HLA-Dr, being more mature progenitor cells already committed to differentiate along a specific lineage. The percentage of CD34+ obtained in blood of adult patients after mobilization with chemotherapeutic agents and growth factors showed an average value of 2.7± 3.1%. The percentage of CD34+ in the apheresis products of various patients varied from 0.58 to 1.48. In some cases the cells were reinfused in the patient with good results. Our findings are in agreement with previous studies suggesting that CD34+ stem cells is a heterogeneous population, with each subset having variable degree o commitment to differentiate toward a specific cell lineage.As células progenitoras hematopoéticas são as responsáveis pela produção de todos os elementos do sangue e são as potenciais fontes de células usadas para o tratamento de várias condições patológicas. O principal objetivo deste trabalho foi identificar e quantificar as células progenitoras hematopoiéticas no sangue fetal do período pré-natal, no

  20. Pensamiento y lenguaje variacional: una aplicación al estudio de la derivada

    OpenAIRE

    Molina, Juan Gabriel; Sánchez, Mario

    2006-01-01

    El presente escrito muestra una descripción del taller denominado "pensamiento y lenguaje variacional: una aplicación al estudio de la derivada" que se desarrolló en la ciudad de Montevideo, Uruguay, en el marco de la Decimonovena Reunión Latinoamericana de Matemática Educativa. Además de presentar esta descripción, el escrito contiene algunas reflexiones relacionadas con los contenidos matemáticos abordados en este taller.

  1. Introducción a la derivada en un contexto tecnológico-variacional

    OpenAIRE

    Sánchez, Mario

    2006-01-01

    En el siguiente escrito se describe una propuesta didáctica para introducir a los estudiantes al concepto matemático de la derivada. Esta propuesta se basa en la idea de variación la cual es representada en contextos numéricos, físicos y gráficos. La representación y manipulación de las ideas matemáticas en juego durante el desarrollo de la propuesta se ven apoyadas en el uso de dispositivos tecnológicos tales como calculadoras gráficas y un sensor de movimiento.

  2. Algunas dificultades en la resolución de problemas con derivadas

    OpenAIRE

    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...

  3. Determinación espectrofluorimétrica de fitohormonas derivadas del indol y del naftaleno

    OpenAIRE

    Blanc García, María del Rosario

    2014-01-01

    Se realiza el estudio de las propiedades fluorescentes y la puesta a punto de metodología espectrofluorimétrica en disolución y en fase sólida para la determinación en aguas, suelos y formulaciones comerciales de las fitohormonas derivadas del indol: acido indol-3-acetico. acido indol-3-butirico, acido indol-3-propinoico y acido 5-hidroxiindol-3-acetico; y del naftaleno: acido 1-naftilacetico y 1-naftilacetamida. se lleva a cabo la determinación individual de cada una de las fitohormonas as...

  4. Derivada parcial de un campo vectorial respecto de una variable escalar

    OpenAIRE

    Macho Ortiz, Andrés

    2014-01-01

    Derivar un campo vectorial respecto una variable escalar (por ejemplo el tiempo o la frecuencia) no es nada evidente. Hay un momento en que nos encontramos con la necesidad de derivar los vectores unitarios de la base del sistema de coordenadas respecto de esa variable escalar. Si trabajamos con coordenadas cilíndricas o esféricas dicha derivada no tiene por qué ser nula y hay que calcularla, que es lo difícil del asunto. Para poder calcularla habrá que hacer un cálculo tedioso qu...

  5. Una propuesta didáctica para la enseñanza del concepto de derivada

    OpenAIRE

    2013-01-01

    El propósito de la investigación fue determinar la diferencia en el aprendizaje significativo del concepto de derivada y reglas de derivación, en dos grupos de estudiantes de cálculo diferencial de la Universidad del Quindío, en uno utilizando la estrategia didáctica de enseñanza orientada desde conceptos previos, recorrido histórico, fases real, simbólica y conceptual y la resolución de problemas, y en el otro la estrategia didáctica tradicional, el tipo de investigación fue comparativa y co...

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

    OpenAIRE

    Jódar, L.; 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...

  7. Método para construir gráficos de funciones sin el uso de derivadas

    Directory of Open Access Journals (Sweden)

    Luis Alberto Escalona-Fernández

    2012-01-01

    Full Text Available Se elaboró un método para determinar los extremos locales, intervalos de convexidad, puntos de inflexión de funciones racionales y la resolución de problemas de optimización, el cual constituye una novedad científica, no solo desde el punto de vista matemático sino también de la Didáctica. Se estudian las propiedades topológicas de estas funciones. La generalización del método incluye la determinación de puntos de inflexión, sin el uso de límites y derivadas; no se utilizan las condiciones necesarias y suficientes, expresadas en los criterios de la primera, segunda y enésima derivadas. El análisis de los cálculos realizados pueden efectuarse con lápiz y papel; sin embargo la utilización de las Tecnologías Informáticas permiten a estudiantes y profesores incontables posibilidades.

  8. 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

  9. El estudio de la tasa de variación como una aproximación al concepto de derivada

    OpenAIRE

    Villa-Ochoa, Jhony

    2013-01-01

    En este artículo describo un estudio de casos en el cual un conjunto de cuatro estudiantes se aproximaron al concepto de derivada a partir de la comprensión de la tasa de variación. Particularmente presento algunos episodios en los cuales a través del uso de los software dinámicos GeoGebra y Modellus las estudiantes observaron la tasa de variación media y produjeron algunas ideas asociadas a la derivada como una tasa de instantánea. Los resultados de este investigación resaltan la importancia...

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

    OpenAIRE

    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...

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

    OpenAIRE

    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

  12. Retinal tissue transplantation and retinal progenitor cells: A therapeutic promise for patients with retinal disease Trasplante de tejido retiniano y de células progenitoras retinianas: una promesa terapéutica para pacientes con enfermedad de la retina

    Directory of Open Access Journals (Sweden)

    Diana Estefania Jiménez

    2010-02-01

    Full Text Available

    Worldwide, diabetic retinopathy, age-related macular degeneration, and retinitis pigmentosa have the highest incidence rate among retinal diseases. Despite the lack of enough trials demonstrating positive functional results on eyesight recovery, the use of stem cells, retinal progenitor cells, and fetal retinal tissue transplantation seem very promising. So far positive results on the functionality of the transplanted cells have not been obtained. However, the safety and reliability of the procedure to transfer retinal tissue have been demonstrated. Transplantation of retinal progenitor cells has not been tried on human beings, but there have been satisfactory 1 Médica general, Universidad del Norte, Barranquilla, Colombia. Residente de primer año de Oftalmología, Universidad CES, Medellín, Colombia.

    La retinopatía diabética, la degeneración macular relacionada con la edad y la retinitis pigmentosa son las enfermedades retinianas más frecuentes en todo el mundo. A pesar de no contar con suficientes estudios que demuestren resultados funcionales positivos en cuanto a recuperar la función visual, el uso de células madre y células progenitoras retinianas y el trasplante de retina fetal parecen bastante promisorios. Hasta el momento no se han podido obtener resultados positivos sobre la funcionalidad de las células trasplantadas, pero sí se ha demostrado que el procedimiento para transferir el tejido retiniano es seguro y

  13. 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

  14. 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...

  15. Una aproximación ontosemiótica a la didáctica de la derivada

    OpenAIRE

    Font, Vicenç

    2005-01-01

    En este trabajo se presenta un resumen del enfoque ontosemiótico de la cognición matemática y se comentan diferentes investigaciones, sobre la didáctica de la derivada, en las que se ha utilizado esta teoría. Dichos trabajos han permitido detectar determinados fenómenos didácticos y sugerir su explicación.

  16. 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

  17. ESTUDIO DE LA FUNCION DE LA VIA DE SEÑALIZACION SHH/GLI EN LOS PROCESOS DE PROLIFERACION Y DIFERENCIACION DE CELULAS DEL LIGAMENTO PERIODONTAL HUMANO

    OpenAIRE

    MARTINEZ CARDOZO; CONSTANZA

    2011-01-01

    Las células troncales mesenquimales y progenitoras residentes en el ligamento periodontal humano constituyen una población de células troncales adultas con características similares a las células troncales mesenquimales de la medula ósea que son capaces de diferenciarse a varios linajes. Considerando su importante papel en la regeneración periodontal, es de suma importancia la identificación de los factores que controlan su proliferación y diferenciación. Sanie hedgehog (Shh) correspond...

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

    Directory of Open Access Journals (Sweden)

    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

  19. Métodos computacionales de optimización sin derivadas para minimización con restricciones

    OpenAIRE

    Arouxét, María Belén

    2013-01-01

    La optimización sin derivadas es un área de creciente interés por su potencial relación con aplicaciones en otras disciplinas, dado que es frecuente no contar con una expresión explícita de las funciones involucradas en el problema de optimización sino sólo datos experimentales o simulaciones computacionales. Por lo tanto el objetivo general de este plan es desarrollar nuevos algoritmos eficientes y robustos basados en estrategias adecuadas, analizando su convergencia y validando los mismos m...

  20. Co-cultivo de embriões bovinos com células-tronco adultas derivadas de tecido adiposo

    OpenAIRE

    NASCIMENTO, Hamilton Silva do

    2014-01-01

    A produção in vitro de embriões (PIV) é uma biotecnologia utilizada para aumentar o potencial reprodutivo de animais geneticamente superiores, os embriões produzidos in vitro são de qualidade inferior aos produzidos in vivo, por isso técnicas tentam melhorar os índices de embriões produzidos in vitro. Uma técnica é o sistema de co-cultivo com células somáticas que removem metabólitos tóxicos e protegem contra o stress oxidativo. As células-tronco mesenquimais derivadas de tecido adiposo (CTA)...

  1. 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

    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. ...

  2. 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

  3. Métodos alternativos en la búsqueda de los puntos críticos y derivadas de algunas funciones

    OpenAIRE

    Karelin, Alexander; Rondero, Carlos; Tarasenko, Anna

    2004-01-01

    Para hacer sentir más profundamente qué son los puntos mínimos y máximos es útil regresar a sus definiciones. Se proponen ejemplos de funciones como polinomio de tercer grado, seno, coseno y otras para las cuales se encuentran puntos críticos sin usar la derivada. Las nociones del límite y derivada de una función en un punto son tradicionalmente difíciles de comprender por parte de los alumnos de bachillerato y licenciatura. Las dificultades se encuentran precisamente en las definiciones de e...

  4. 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.

  5. La derivada como objeto matemático y como objeto de enseñanza y aprendizaje en profesores de matemática de Colombia: "la derivada un concepto a caballo entre la matemática y la física"

    OpenAIRE

    2003-01-01

    Consultable des del TDX Títol obtingut de la portada digitalitzada El objetivo de esta investigación ha sido identificar y describir la relación e integración entre el conocimiento del contenido matemático y el conocimiento didáctico del contenido con relación al concepto de derivada de profesores de matemática en ejercicio. En efecto, nos interesa describir la naturaleza y estructura de las formas de conocer el concepto de derivada como objeto matemático y como objeto de enseñanza y ap...

  6. 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.

  7. Interpretación física de la derivada de una función, un objeto de aprendizaje presentado en comics

    OpenAIRE

    Santoyo, Felipe; Santoyo, Eliseo; Puga, Karla Liliana

    2012-01-01

    En el marco de la Reforma Integral de la Educación Media Superior en México, se entiende que la enseñanza de la Matemática debe orientarse hacia el manejo de los conceptos y herramientas indispensables para comprender la disciplina. Para abordar el tema “interpretación física de la derivada de una función”, se diseñó un objeto de aprendizaje, partiendo de una situación problema que recupera el abordaje clásico, –La derivada como una velocidad instantánea–. Se diseñó una historieta con dibujos...

  8. 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 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.

  9. Determinación simultánea de metales con el ácido dietilenotriaminopentaacético (ADTP) por espectrofotometría derivada

    OpenAIRE

    Pérez Iglesias, Julia

    2011-01-01

    [Resumen] SE REALIZO UN ESTUDIO BIBLIOGRAFICO ACERCA DEL USO DEL ACIDO DIETILENOTRIAMINOPENTAACETICO (ADTP) COMO AGENTE QUELATANTE, DESDE SU PRIMERA UTILIZACION POR WANNINEN EN 1975.SE HACE UNA INTRODUCCION TEORICA A LA ESPECTROFOTOMETRIA DE DERIVADAS DE PRIMER Y SEGUNDO ORDEN, ANALIZANDO SUS METODOS, VENTAJAS Y PRINCIPALES APLICACIONES, INCIDIENDO ESPECIALMENTE SOBRE SU APLICACION A LAS DETERMINACIONES SIMULTANEAS DE DIFERENTES CATIONES METALICOS EN SUS MEZCLAS.SE PROPONEN LOS PROCED...

  10. Comportamento biológico de matriz scaffold acrescida de células progenitoras na reparação óssea Bone marrow progenitor cells enriched scaffold biological behavior in bone repair

    Directory of Open Access Journals (Sweden)

    Débora Cristina Olsson

    2008-11-01

    Full Text Available A engenharia tecidual desenvolve e manipula células ou tecidos para a reconstrução de novos órgãos e tecidos. A perda ou a falência da função de partes teciduais alteradas ou lesadas torna-se um problema severo à saúde animal e uma indicação para tratamento é o transplante para substituir a função biológica perdida. Vários animais são afetados por estes problemas, razões estas que indicam a necessidade de desenvolvimento de terapias alternativas para tratar perdas ósseas. Estudos experimentais contribuem para avanços da medicina regenerativa, como a engenharia de tecidos, com o objetivo de desenvolver suportes sintéticos ou utilizar arcabouços naturais, conhecidos como scaffold, que substituam as funções fisiológicas do tecido ósseo. Atualmente para, a obtenção destes objetivos utilizam-se também, de forma genérica, combinações específicas com células progenitoras (CP da medula óssea (MO do próprio paciente ou doador que são distribuídas em um material de suporte tridimensional com propriedades adequadas, gerando um material híbrido cujas características podem ainda ser moduladas para então ser reinserido no paciente. O objetivo desta revisão é apresentar informações sobre o comportamento biológico de materiais sintéticos e naturais apropriados para implantes ósseos, acrescidos ou não de CP, para o estímulo do processo reparativo de tecido ósseo.Tissue engineering involves the manipulation and the development of cells aiming to create and/or regenerate organs and tissues. Function failure of injuried tissues is a severe animal health problem, nevertheless, the transplantation has been indicated to treat and replace the biological function. A large amount of animals are affected by those problems, and for this reason it is necessary to find alternative therapies to treat bone losses. Studies such those involving tissue engineering have contributed to regenerative medicine advances, to developed

  11. Disfunción hepática en el trasplante de células progenitoras hematopoyéticas. Impacto sobre la mortalidad Liver dysfunction in recipients of hematopoietic stem cells. Impact on mortality

    Directory of Open Access Journals (Sweden)

    Daniel Cocozzella

    2005-04-01

    Full Text Available El compromiso hepático en receptores de trasplante alogénico de células progenitoras hematopoyéticas (TCPH es una complicación muy frecuente y es responsable de la morbimortalidad precoz. La toxicidad por fármacos, la enfermedad injerto versus huésped (EICH, la enfermedad venooclusiva (EVO y las infecciones fúngicas, bacterianas y virales constituyen las principales etiologías. El objetivo de este estudio retrospectivo fue establecer la prevalencia y etiología de la afectación hepática, evaluar el impacto en la mortalidad y analizar el valor predictivo de las transaminasas pre TCPH en la ocurrencia de EICH agudo, crónico y mortalidad. De un total de 236 pacientes trasplantados, se evaluaron 82 sometidos a TCPH alogénico. El 88% de los pacientes tuvo afectación hepática: EICH agudo 40.2%, EICH crónico 15.9%, de causa indeterminada 9.8%, sepsis 7.3%, toxicidad por fármacos 6.1%, EVO 3.7%, hepatitis aguda y recidiva de enfermedad 2.4%. La mortalidad evaluada al año fue 36.6%. La insuficiencia hepática aguda (IHA representó el 10% de las muertes. Las causas de IHA fueron: progresión de EICH agudo, recidiva de la enfermedad hematológica en el hígado, hepatitis herpética y EVO. El valor predictivo positivo de las transaminasas pre TCPH para EICH agudo, crónico y mortalidad fue 0.27, 0.14 y 0.43 respectivamente. No se hallaron diferencias significativas entre pacientes con pruebas bioquímicas hepaticas pre TCPH alteradas o normales en la ocurrencia de EICH agudo, crónico o mortalidad.Liver disease is a well-known cause of early morbidity and mortality affecting 80% of patients receiving allogeneic bone-marrow transplantation (BMT. Drug toxicity, veno-occlusive disease (VOD, acute graft-versus-host disease (GVHD, and fungal, bacterial, and viral infections are the most frequent hepatic complications during this period. The aim of this retrospective study was to determine the prevalence and etiology of liver disease and its

  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. Terapia gênica com fator de crescimento endotelial vascular 165 para pacientes com angina refratária: mobilização de células progenitoras endoteliais

    Directory of Open Access Journals (Sweden)

    Clarissa G. Rodrigues

    2013-08-01

    Full Text Available FUNDAMENTO: O fator de crescimento endotelial vascular (VEGF - vascular endothelial growth factor induz a mobilização de células progenitoras endoteliais (CPEs com capacidade de proliferação e diferenciação em células endoteliais, contribuindo, dessa forma, para o processo angiogênico. OBJETIVO: Buscamos avaliar o comportamento de CPEs em pacientes com doença cardíaca isquêmica e angina refratária que receberam injeções intramiocardicas de 2000 µg de VEGF165 como terapia única. MÉTODOS: O estudo foi uma subanálise de um ensaio clínico. Pacientes com doença cardíaca isquêmica avançada e angina refratária foram avaliados para inclusão no estudo. Os critérios de inclusão foram: sinais e sintomas de angina e/ou insuficiência cardíaca apesar de tratamento medicamentoso máximo e área de isquemia miocárdica de, no mínimo, 5% conforme avaliado por uma tomografia computadorizada por emissão de fóton único (TCEFU. Os critérios de exclusão foram: idade > 65 anos, fração de ejeção do ventrículo esquerdo < 25% e cancer diagnosticado. Os pacientes cujos níveis de CPE foram avaliados foram incluídos. A intervenção consistiu na administração de 2000 µg de VEGF 165 de plasmídeo injetado no miocárdio isquêmico. A frequência de células CD34+/KDR+ foi analisada por citometria de fluxo antes e 3, 9, e 27 dias após a intervenção. RESULTADOS: Um total de 9 pacientes foram incluídos, 8 homens, média de idade de 59,4 anos, fração de ejeção ventricular esquerda de 59,3%, e classe de angina predominante III. Observou-se um aumento significativo dos níveis de CPEs no terceiro dia após a intervenção. Todavia, 9 e 27 dias após a intervenção, os níveis de CPEs foram similares aos basais. CONCLUSÃO: Identificamos uma mobilização transitória de CPE, com pico no terceiro dia após a intervenção com VEGF 165 em pacientes com angina refratária. Todavia, os níveis de CPEs apresentaram-se semelhantes

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

  16. Anfetaminas e drogas derivadas

    OpenAIRE

    Muakad, Irene Batista

    2013-01-01

    Sintetizada pela primeira vez na Alemanha, a anfetamina é, portanto, droga sintética, fabricada em laboratório, a qual, por sua vez, estimula o sistema nervoso central. A anfetamina faz com que o cérebro funcione mais rápido do que o normal, acarretando um estado hiperativo nos indivíduos usuários. Synthesized for the first time in Germany, amphetamine is a synthetic, laboratory produced drug, which stimulates the central nervous system. Amphetamine makes brain activities to run faster tha...

  17. Revisión sistemática: células madre derivadas del tejido adiposo, utilidad en lipoatrofia facial

    Directory of Open Access Journals (Sweden)

    M.D. Cruz-Sánchez

    2014-06-01

    Full Text Available El objetivo de la presente revisión sistemática es determinar si los lipoinjertos enriquecidos con células madre derivadas del tejido adiposo son superiores a los injertos de tejido graso convencionales en el tratamiento de la lipoatrofia facial. Realizamos una búsqueda sistemática de publicaciones en las bases de datos: MEDLINE, SCOPUS, OVID SP, SCIELO y EMBASE y posteriormente, una valoración basada en criterios actuales de medicina basada en la evidencia de las publicaciones encontradas por dos revisores independientes; las discrepancias en el análisis se resolvieron por acuerdo. Los criterios de inclusión fueron: ensayos clínicos aleatorizados, series clínicas y reportes de casos en humanos, excluyendo los ensayos en animales. Encontramos 6 publicaciones que cumplían con los criterios previamente mencionados. Entre éstas se incluyeron 2 ensayos clínicos aleatorizados controlados que recogían la superioridad de los lipoinjertos enriquecidos con células madre derivadas del tejido adiposo en el tratamiento de la lipoatrofia facial en términos de resistencia a la reabsorción (preservación del volumen y menor necesidad de nuevos lipoinjertos, en comparación con los lipoinjertos convencionales. Concluimos diciendo que existen publicaciones con buenos niveles de evidencia que sugieren que los lipoinjertos enriquecidos con células madre derivadas del tejido adiposo son superiores a los lipoinjertos convencionales en el tratamiento de la lipoatrofia facial. No obstante, son estudios de reciente publicación y aún es necesario tener seguimientos a más largo plazo y con mayor número de pacientes para mejorar los ya buenos niveles de evidencia disponibles.

  18. La tributación en España de la renta derivada del comercio de derechos de emisión de CO2

    OpenAIRE

    Salassa Boix, Rodolfo Rubén

    2011-01-01

    La presente tesis estudia la tributación de la renta derivada del comercio de derechos de emisión de CO2. Este mercado fue implantado por el Protocolo de Kioto para facilitar el cumplimiento de sus objetivos ambientales y constituye un fenómeno jurídico-comercial hasta ahora desconocido que, como tal, tiene sus consecuencias tributarias. El trabajo propone una solución a la compleja cuestión de la tributación de los derechos de emisión de CO2, ya que la normativa vigente resulta insuficien...

  19. 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...

  20. Revisión sistemática: células madre derivadas del tejido adiposo, utilidad en lipoatrofia facial

    OpenAIRE

    M.D. Cruz-Sánchez; O. Gómez-Díaz.

    2014-01-01

    El objetivo de la presente revisión sistemática es determinar si los lipoinjertos enriquecidos con células madre derivadas del tejido adiposo son superiores a los injertos de tejido graso convencionales en el tratamiento de la lipoatrofia facial. Realizamos una búsqueda sistemática de publicaciones en las bases de datos: MEDLINE, SCOPUS, OVID SP, SCIELO y EMBASE y posteriormente, una valoración basada en criterios actuales de medicina basada en la evidencia de las publicaciones encontradas po...

  1. Impacto de fatores sistêmicos e comportamentais sobre os resultados do tratamento de defeitos periodontais com proteínas derivadas da matriz do esmalte

    OpenAIRE

    Mônica Grazieli Corrêa

    2013-01-01

    Resumo: Fator sistêmico e comportamental tem sido relacionado não somente com o início e progressão da doença periodontal, mas também com a resposta ao tratamento dessa doença. Os objetivos destes estudos foram avaliar o efeito das proteínas derivadas da matriz do esmalte (EMD) sobre reparo e regeneração de defeitos periodontais não contaminados em ratos submetidos a: i) diabetes mellitus induzida (DM); ii) estresse crônico (EC). Métodos: Para cada trabalho, foram designados os seguintes grup...

  2. Reconocimiento en España de la filiación derivada de gestación por sustitución

    OpenAIRE

    Cyrielle, Agut

    2016-01-01

    En el presente trabajo analizo en qué medida podría ser admitido el reconocimiento, en España, de la filiación derivada de maternidad subrogada realizada en el extranjero. Concretamente, estudiaré como puede ser reconocida la resolución extranjera de filiación en el ordenamiento jurídico español, cumpliendo los requisitos legales y conformes con el orden público. ¿En qué medidas las últimas instrucciones de la Dirección General del Registro y del Notariado (en adelante, DGRN) ofrecen una posi...

  3. 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

  4. 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).

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

    Directory of Open Access Journals (Sweden)

    Samira Yarak

    2010-10-01

    Full Text Available 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 tecidual. As células-tronco adultas derivadas do estroma do tecido adiposo apresentam potencial para se diferenciarem em células de tecidos mesodérmicos, como os adipócitos, as cartilagens, os ossos e o músculo esquelético e não mesodérmicos, como os hepatócitos, as células pancreáticas endócrinas, os neurônios, os hepatócitos e as células endoteliais vasculares. Entretanto, os dados disponíveis na literatura científica sobre as características das células-tronco adultas derivadas do estroma do tecido adiposo e os procedimentos para sua obtenção e manipulação no laboratório são inconsistentes. É necessário o desenvolvimento de metodologias e procedimentos eficazes de isolamento dessas células para obtenção de células em quantidade e qualidade suficientes para aplicação terapêutica. Nesta revisão, são discutidos os métodos correntes de coleta de tecido adiposo, isolamento e caracterização de células-tronco adultas derivadas do estroma do tecido adiposo, com ênfase na futura aplicação em medicina regenerativa e nos possíveis desafios nesse recente campo da ciência.Adult or somatic stem cells hold great promise for tissue regeneration. Currently, one major scientific interest is focused on the basic biology and clinical application of mesenchymal stem cells. Adipose tissue-derived stem cells share similar characteristics with bone marrow mesenchymal stem cells, but have some advantages including

  6. La construcción de la derivada a través de la noción de variación en estudiantes de nivel superior

    OpenAIRE

    Barrera, Javier

    2002-01-01

    Nuestro objetivo es analizar los procedimientos de cómo los estudiantes (nivel superior) construyen el concepto de derivada a través de la noción de variación. Esta noción constituye la línea directriz mediante la cual, se pretende construir uno de los conceptos más importantes del cálculo: la derivada (Dolores 1999). Podemos mencionar una serie de factores que propician los fracasos escolares. Sin embargo, consideramos que dos de los principales son: A) La pobreza conceptual que se maneja en...

  7. Detección de suero de quesería en leches ultrapasteurizadas mexicanas mediante la cuarta derivada del espectro de absorción

    OpenAIRE

    Acacia Ramírez Ayala; Salvador Vega y León; Guadalupe Prado Flores; Rey Gutiérrez Tolentino; Cuauhtémoc Pérez González

    2008-01-01

    Se determinó la presencia de suero de quesería en leches ultrapasteurizadas (UHT) comercializadas en la Ciudad de México mediante el método de la cuarta derivada del espectro de absorción, el cual permite conocer la variación de la relación proteínas de suero/proteína total (PS/PT). La cuantifi cación de la relación PS/PT se utilizó como indicador de la adulteración con suero de quesería. El método fue estandarizado evaluando la exactitud, linealidad y repetibilidad mediante la adición de sue...

  8. Análisis de la culpa en el incumplimiento de las obligaciones derivadas del contrato de prestación de servicios médicos

    Directory of Open Access Journals (Sweden)

    Betty Mercedes Martínez-Cárdenas

    2010-03-01

    Full Text Available A pesar de su fácil formulación, la distinción entre obligaciones de medios y de resultado para determinar el contenido de las obligaciones del galeno en el contrato de prestación de servicios médicos es insuficiente. Ella, para poder ser aplicada,  necesita además de la graduación de la culpa. Así, la antigua teoría de la prestación de las culpas se redescubre hoy como la manera más adecuada para determinar la intensidad del cuidado que el médico debe poner en el cumplimiento de su obligación, en procura de la eficacia de un sistema de responsabilidad que no busque únicamente la obtención de una reparación, sino también la creación de la convicción necesaria para actuar en beneficio propio, mutuo y de la sociedad durante la ejecución de las  obligaciones derivadas de un contrato.

  9. El régimen de las indemnizaciones por las privaciones singulares derivadas de la legislación de conservación de la biodiversidad

    Directory of Open Access Journals (Sweden)

    Fernando López Ramón

    2011-01-01

    Full Text Available Se pretende identificar los supuestos requeridos de indemnización por parte de la Administración pública como consecuencia de las privaciones singulares derivadas del régimen de los espacios naturales protegidos en el Derecho español. Para ello se analizan los datos doctrinales, jurisprudenciales y normativos, exponiendo los inconvenientes de las diversas posturas y se ter - mina identificando como supuesto típico de situación requerida de indemnización la caracterizada por la concurrencia simultánea de dos requisitos: afectar a usos y actividades permitidos en suelo no urbanizable e incidir sobre facultades en ejercicio efectivo por parte de sus titulares. No obstante, la crítica de esos requisitos permite reflejar las carencias del indicado supuesto típico, que precisa ser completado con una cláusula general de responsabi - lidad administrativa para incluir las restantes privaciones singulares que pudieran concurrir en los espacios naturales protegidos.

  10. 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.

  11. EL PROCESO DE ENSEÑANZA-APRENDIZAJE DE LA DERIVADA EN LA CARRERA DE COMERCIO EXTERIOR Y NEGOCIOS INTERNACIONALES DE LA UNIVERSIDAD LAICA ELOY ALFARO DE MANABÍ

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    Miguel Escalona-Reyes

    2017-01-01

    Full Text Available La Educación Superior en Ecuador se encuentra en un proceso de perfeccionamiento,  debido a la necesaria transformación que debe asumir para asumir un nuevo redimensionamiento de la misión de la universidad contemporánea ante los retos del nuevo siglo. Uno de los cambios fundamentales radica en el perfeccionamiento del currículo de las carreras, y con ello de los programas de las diferentes materias; para el caso del estudio de la Matemática, no puede desvincularse su estudio del contexto social y el proyecto social en que se desarrolla el proceso pedagógico de los profesionales en formación, de la misma manera que no se puede concebir como algo abstracto y general, debiendo conjugarse con los objetivos y con las tareas que dimanan de los resultados parciales del espacio y del tiempo en el que transcurren. Uno de los temas de esta asignatura, esenciales para el estudiante de la carrera de Comercio Exterior y Negocios Internacionales, es la derivada, ya que permite aplicar dicho conocimiento en la resolución de ejercicios y problemas que son afín con la vida profesional del estudiante. No obstante, se ha constatado varias insuficiencias en el proceso de enseñanza aprendizaje de estos contenidos en esta carrera; motivo por el cual se realiza esta investigación, donde se presenta una Alternativa Metodológica para favorecer dicho proceso.PALABRAS CLAVE: Didáctica de la Matemática; Derivada; Formación Profesional.THE TEACHING-LEARNING PROCESS OF DERIVATIVES IN THE CARRER OF FOREIGN TRADE AND INTERNATIONAL BUSINESS FROM THE UNIVERSIDAD LAICA ELOY ALFARO DE MANABÍABSTRACTHigher Education in Ecuador is involved in a process of improvement, due to the necessary transformation which must be followed to assume a new downsizing of the mission of nowadays university in the challenges of the new century. One of the main changes lies in the improvement of the curriculum of courses, and the syllabus in different subjects; respected to the case

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

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    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 .

  13. 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

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    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.

  14. AVALIAÇÃO DE PROGÊNIES DERIVADAS DO HÍBRIDO DE TIMOR COM RESISTÊNCIA AO AGENTE DA FERRUGEM

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    SILVAROLLA MARIA BERNADETE

    1997-01-01

    foi observado na população C2591-5 derivada de CV x HT, que além de produtivo apresenta resistência ao agente da ferrugem.

  15. Endogamia de líneas Z’ y líneas PL’ de polinización libre de maíz, derivadas de una población de líneas S1

    OpenAIRE

    2004-01-01

    En una investigación previa (Márquez, 2004) se demostró que líneas Z y de polinización libre (PL) de maíz (Zea mays L.), derivadas de una población de individuos no endogámicos ni emparentados, tienen valores de endogamia iguales en generaciones coincidentes. Esto fue cierto aun si las manipulaciones algebraicas para calcular la endogamia en los dos tipos de líneas fueron diferentes. Aquí se demuestra que los coeficientes de endogamia de las líneas PL son los mismos que los de las líneas Z; s...

  16. 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

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    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

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

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    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.

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

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    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.

  19. derivadas de la investigación

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    Ángel Vázquez-Alonso

    2007-01-01

    Full Text Available 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 otros valores incompatibles con ellos (factores sociales, culturales o afectivos, tildados como impropios o acientíficos por oponerse a la objetividad de la ciencia, aunque sean didácticamente valiosos. Sin embargo, los análisis y las críticas filosóficas, sociológicas e históricas sobre el positivismo lógico han enfatizado la presencia de los aspectos afectivos, actitudinales y emocionales, entre otros más, en la construcción del conocimiento científico. Este estudio argumenta la necesidad de los factores actitudinales y afectivos como resortes imprescindibles para la didáctica de la ciencia. En esta segunda parte se exponen pruebas empíricas provenientes de la investigación específica sobre las variables afectivas relativas a la ciencia y la tecnología (actitudes hacia la ciencia escolar, creencias sobre naturaleza de la ciencia, imagen pública de la ciencia, actitudes hacia el medio ambiente, vocaciones científicas, etc..

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

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    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

  1. 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.

  2. 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; Rodrigo, D.; 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...

  3. 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

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    Luís Roberto Paschoal

    2003-03-01

    Full Text Available 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, reproductive and of low cost.

  4. Sobre as incertezas do tipo A e B e sua propagação sem derivadas: uma contribuição para a incorporação da metrologia contemporânea aos laboratórios de física básica superior

    OpenAIRE

    2011-01-01

    Após introduzir o conceito de incerteza, distinguindo procedimentos de avaliação da incerteza do tipo A e do tipo B, o presente artigo discute a lei de propagação da incerteza definida no Guia para Expressão da Incerteza da Medição, apresentando sua dedução e fundamentos. O objetivo deste trabalho é introduzir um procedimento alternativo que permite calcular a incerteza que se propaga das grandezas de entrada para a grandeza de saída sem referência explícita a derivadas parciais. Como o proce...

  5. Sobre as incertezas do tipo A e B e sua propagação sem derivadas : uma contribuição para a incorporação da metrologia contemporânea aos laboratórios de física básica superior

    OpenAIRE

    2011-01-01

    Após introduzir o conceito de incerteza, distinguindo procedimentos de avaliação da incerteza do tipo A e do tipo B, o presente artigo discute a lei de propagação da incerteza definida no Guia para Expressão da Incerteza da Medição, apresentando sua dedução e fundamentos. O objetivo deste trabalho é introduzir um procedimento alternativo que permite calcular a incerteza que se propaga das grandezas de entrada para a grandeza de saída sem referência explícita a derivadas parciais. Como o proce...

  6. Estructura genética del caballo de pura raza árabe español y su influencia en razas derivadas: aplicación de nuevas metodologías en el cálculo del tamaño efectivo

    OpenAIRE

    Cervantes Navarro, Isabel

    2011-01-01

    Durante el desarrollo del estudio se ha analizado la estructura genética del caballo de Pura Raza Árabe y de sus razas derivadas y se ha puesto a punto una nueva metodología de estimación del tamaño efectivo, aplicándose en poblaciones simuladas y reales. Se observó una reducida variabilidad genética en el caballo de Pura Raza Árabe Español, ocasionada por el desequilibrio en la utilización de los reproductores y el cuello de botella acaecido durante la Guerra Civil. Este hecho está compensán...

  7. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    S. T. L. Pinto Filho

    2015-10-01

    Full Text Available 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, utilizando como agente imunomodulador ADSCs alogênicas. Para isso foram utilizados 25 coelhos, sendo um deles macho e doador das ADSCs, e os outros 24 eram fêmeas, submetidas a alotransplante parcial de bexiga, sendo tratadas com ciclosporina (GCi ou células-tronco mesenquimais (GCe. Conclui-se que as ADSCs foram suficientes para evitar sinais clínicos e ecográficos de rejeição ao alotransplante de vesícula urinária, mantendo a estrutura anatomofisiológica vesical por até 30 dias em coelhos.

  9. Padronização de método analítico para avaliação do grau de exposição da fenilalanina em hidrolisados de caseína, por espectrofotometria derivada segunda Standardization of analytical method to determination of phenylalanine exposure in casein hydrolysates by second derivative spectrophotometry

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    Cristiane Márcia da Silva Barbosa

    2002-03-01

    Full Text Available Hidrolisados protéicos com baixo teor ou isentos de fenilalanina (Phe têm sido empregados em formulações para fenilcetonúricos. Várias condições de hidrólise enzimática têm sido propostas na literatura para promover a liberação de Phe e, assim, facilitar sua remoção posterior. Neste trabalho, a espectrofotometria derivada segunda (EDS, um método analítico rápido, simples e de custo relativamente baixo, foi utilizada, inicialmente, para a caracterização dos aminoácidos aromáticos e, em seguida, para a determinação do grau de exposição da Phe em diferentes hidrolisados de caseína, obtidos pela ação da papaína. Os resultados obtidos indicam que o hidrolisado preparado à temperatura de 37 ºC, relação enzima/substrato de 4%, pH 7,5, foi o que apresentou o maior grau de exposição da Phe, sendo o mais indicado para a preparação de dietas para fenilcetonúricos. Com relação à caracterização dos aminoácidos aromáticos, o emprego da EDS permitiu a separação dos picos de tirosina (Tyr e triptofano (Trp, em pH 13,0. Além disso, observou-se semelhança entre os espectros de derivada segunda das soluções contendo somente os aminoácidos aromáticos e dos hidrolisados de caseína.Dietetic formulations for phenylketonurics generally contain free or low phenylalanine protein hydrolysates. Several hydrolytic conditions have been proposed in the literature to increase phenylalanine (Phe exposure, in order to favor its subsequent removal. The second derivative spectrophotometry (SDS, a fast, simple and low cost analytical method, was used, in this work, for the determination of Phe exposure in different casein hydrolysates, prepared by using papain, and also for the characteriztion of aromatic amino acids. A temperature of 37 ºC, an enzyme:substrate ratio of 4% and a pH 7.5 showed to be the most suitable condition for preparing phenylketonuric diets, since they led to the highest Phe exposure. Concerning the

  10. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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

    Directory of Open Access Journals (Sweden)

    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.

  13. Relaciones de recurrencia e identidades entre (formula y sus derivadas Relaciones de recurrencia e identidades entre (formula y sus derivadas

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    Manuel Aguirre

    2010-02-01

    Full Text Available En este trabajo, se le da un sentido a la fórmula (formula  donde (formula .  Nuestra fórmula es una generalización de formulas que aparecen  en ([3] y ([4]. En particular cuando m=1 y , l=1 la formula es considerada por ejemplo, por  Bollini, Giambiagi y Tiommo para la teoría de regularización analítica en las ecuaciones clásicas de Yan-Mills  y sus aplicaciones para el potencial singulars (c.f. [5].In this paper, we give a sense to formula (formula were (formula. Our formula is a generalization of the formulae that appear in ([3] and ([4]. In particular when 1=m  and ,1=l  the formula is considered for example, by Bollini, Giambiagi and Tiommo for their Theory of analytic regularization in classical Yan-Mills equations and its application for the singular potentials (c.f. [5].

  14. 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

    Directory of Open Access Journals (Sweden)

    Erika Rosa Maria Kedor-Hackmann

    2006-03-01

    Full Text Available 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 LiChrospher® 100 RP-18 (5µm column. A mixture of triethylamine in methanol (1:500 v/v and 0.5% ammonium acetate solution (75:25 v/v was used as mobile phase at a flow rate of 1.0 mL/min with UV detection at 225 nm. The retention time of ketoconazole and terconazole were 3.9 min and 5.9 min, respectively, the later being used as internal standard. Analytical curves were linear within a concentration range from 5.0 to 30.0 µg/mL for Method I and 20.0 to 80.0 µg/mL for Method II, with correlation coefficients of 0.9997 and 0.9981, respectively. The relative standard deviation (RSD was 0.56% and 0.41% for simulated and commercial emulsion formulations, respectively, using Method I. The corresponding values were 2.13% and 1.25%, respectively, using Method II. The percentage recoveries were above 100% for both methods. The excipients did not interfere in the analysis. The results showed that either method can be used for rapid ketoconazole determination in pharmaceutical emulsions with precision, accuracy and specificity.Foram desenvolvidos e padronizados métodos por espectrofotometria no ultravioleta (UV por derivada de primeira ordem (Método I e cromatografia líquida de alta eficiência (CLAE (Método II para a determinação quantitativa de cetoconazol em formulações farmacêuticas sob a forma de emulsão obtida no comércio e formulada em laboratório. A espectrofotometria no UV por derivada de primeira ordem foi padronizada usando-se o método do zero

  15. 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

    Directory of Open Access Journals (Sweden)

    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

  16. 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)

  17. MECANISMOS DE TRANSDUCCION ESTIMULOS MECANICOS EN CELULAS CILIADAS DE OVIDUCTO.

    OpenAIRE

    ANDRADE MONTERO, YANIRE NATY

    2004-01-01

    Los epitelios mucociliados de las vías respiratorias y del tracto genital femenino de mamíferos, contienen células ciliadas y células secretoras que forman la unidad funcional responsable del transporte mucociliar, cuya principal función es constituir un 133p.

  18. Ensayos triaxiales de rocas en celula de gran capacidad

    OpenAIRE

    Casellas Ferrer, Javier

    2013-01-01

    El trabajo realizado en esta tesina se centra en la realización de una serie de ensayos a probetas de roca para poder determinar sus características mecánicas principales. Se realizan ensayos destinados a estudiar los fenómenos de fractura en el campo de lo smateriales cuasi-frágiles, ensayo Wedge Splitting Test. Adicionalmente en esta tesina serealizarán ensayos de compresión, tanto compresión simple como compresión triaxial en una celda de confinamiento de alta capacidad utilizando una pren...

  19. INTEGRACION DE UNA CELULA FLEXIBLE DE MECANIZADO, DE TIPO DOCENTE

    OpenAIRE

    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...

  20. 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

    Directory of Open Access Journals (Sweden)

    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

  1. 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

  2. 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)

  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. 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.

  5. Lesiones más frecuentes derivadas de las prácticas de tenis amateur

    OpenAIRE

    Goya, Brian

    2014-01-01

    El tenis es un deporte que se caracteriza por la repetición continua de una serie de gestos. Las exigencias del tenis afectan al cuerpo de los jugadores en las extremidades superiores e inferiores, así como también en el tronco y pueden conducir a patrones de lesión característicos y adaptaciones musculo-esqueléticas. Objetivo: Determinar las lesiones más frecuentes que sufren los tenistas amateurs de la ciudad de Miramar. Materiales y métodos: Durante los meses de Septiembre a Diciembr...

  6. 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

  7. 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...

  8. 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.

  9. Patologías mentales derivadas de los accidentes de tránsito

    OpenAIRE

    2008-01-01

    Toda persona que se expone a un hecho traumático puede reaccionar de diversas maneras. En este artículo se revisan los conceptos de algunas enfermedades mentales relacionadas con accidentes de tránsito basadas en las Clasificaciones Nosográfias Internacionales DSM-IV y CIE 10.Any person exposed to a traumatic event can react in different ways. This article checks the concepts of some mental illnesses related to traffic accidents based on the international classifications (DSM-IV and ICD 10).

  10. Patologías mentales derivadas de los accidentes de tránsito

    Directory of Open Access Journals (Sweden)

    Ginette Campos Villalobos

    2008-09-01

    Full Text Available Toda persona que se expone a un hecho traumático puede reaccionar de diversas maneras. En este artículo se revisan los conceptos de algunas enfermedades mentales relacionadas con accidentes de tránsito basadas en las Clasificaciones Nosográfias Internacionales DSM-IV y CIE 10.Any person exposed to a traumatic event can react in different ways. This article checks the concepts of some mental illnesses related to traffic accidents based on the international classifications (DSM-IV and ICD 10.

  11. Caracterización de las lesiones derivadas del entrenamiento físico militar

    OpenAIRE

    Juan Sebastián Rodríguez Gómez; Julián Alberto Valenzuela Pinzón; Juan David Velasco Rodríguez; Laura Elizabeth Castro Jiménez; Paula Janyn Melo Buitrago

    2016-01-01

    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 apa...

  12. 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.

  13. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Boaventura, Jaime S.; Alencar, Marcelo Goncalves F. de; Amaral, Alexandre Alves do; Benedicto, Joao Paulo Santos; Silva, Marcos A. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica. Dept. de Fisico-Quimica

    2006-07-01

    Fuel cells allow the energy production without the thermodynamic restriction of the conversion of heat into work. Among their various types, the solid oxide fuel cells (SOFC), operating at high temperatures, allow the methane conversion into electricity directly on the anode. The main element of the SOFC is the structure A/E/C: anode/electrolyte/cathode, all sintered at high temperature as resistant ceramic materials. Dense electrolyte (YSZ: zirconia stabilized for Yttria) separates the anode (Ni+Co/YSZ: cobalt promoted nickel, supported on YSZ) and cathode (LSM: strontium-doped lanthanum manganite), both with porosity obtained by graphite addition. To obtain suitable A/E/C pellets, the layer sintering with appropriate mechanical and textural characteristics is essential, requiring excellent electric junctions between them. The cell performance has been evaluated between 850 and 950 degree C, using hydrogen or methane fuel; the tension and current for different resistance values in the electrical circuit have been measured. The cobalt addition to the cell anode significantly increased its activity for the reform reaction. The beneficial effect was probably due to the easier nickel reduction in cobalt presence. This work had the objectives of developing and evaluating electro-catalysts, as well as the solid oxide fuel cells using these catalysts as anode. Five SOFC models (SOFC 1 to SOFC 5) are described; all of them were developed aiming at improving the preparation of the anode/electrolyte/cathode structure (A/E/C). (author)

  15. Efficiency of SOFC type fuel cells; Eficiencia de celulas combustiveis do tipo SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Alexandre Alves do; Matos, Francisco F.; Boaventura, Jaime S.; Benedicto, Joao Paulo S.; Alencar, Marcelo [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica. Dept. de Fisico-Quimica

    2006-07-01

    production of electric energy, mainly due to the fact that it is virtually no pollutant. Typically, the SOFC is constituted of at least seven distinct phases: fuel, anode, electrolyte substrate (separating the two electrodes), cathode, air, and electrical inter connectors (completing the electrical circuit). Thermodynamics clearly shows that electrochemical systems only can be reversible when homogeneous, what it is not case of the Sofc. Therefore, the application of equilibrium thermodynamics to these systems is incorrect. This work proposes that the Sofc can be better depicted from reactions between adsorbed species. The efficiency then is calculated as the ratio between the free energy of these reactions to the combustion heat. Thermodynamic parameter estimative is developed for the global and adsorbed species reactions. (author)

  16. TRANSPORTE DE UDP-GALACTOSA EN EL APARATO DE GOLGI DE CELULAS VEGETALES.

    OpenAIRE

    NORAMBUENA MORALES, LORENA

    2004-01-01

    En vegetales, el aparato de Golgi existe en un gran número de organelos por célula, distribuyéndose homogéneamente por todo el citoplasma. La abundancia de este organelo está en directa relación con la necesidad de depósito de componentes de pared celular 106p.

  17. PROPIEDAD ANTI-ANGIOGENICA DEL FACTOR DE COAGULACION X EN CELULAS ENDOTELIALES

    OpenAIRE

    LANGE SMITH, MARIA SOLEDAD

    2013-01-01

    La angiogénesis es la formación de vasos sanguíneos desde vasos preexistentes y juega un papel importante en el desarrollo embrionario, la formación del cuerpo lúteo y endometrio, la regeneración de tejido y la cicatrización de heridas. También participa en distintas enfermedades como arterioesclerosis, diabetes, soriasis y crecimiento tumoral. Previamente se ha reportado que algunas proteínas involucradas en los sistemas de coagulación y fibrinólisis, como factor tisular, heparin...

  18. Mediastinal large cell lymphoma with sclerosis; Linfoma de grandes celulas com esclerose do mediastino

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Sergio; Pulcheri, Wolmar; Spector, Nelson; Nucci, Marcio; Oliveira, Halley P. de [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil). Dept. de Clinica Medica; Morais, Jose Carlos [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil). Dept. de Patologia; Romano, Sergio [Instituto Nacional do Cancer, Rio de Janeiro, RJ (Brazil). Servico de Patologia

    1995-04-01

    Five cases of primary mediastinal large-cell lymphoma with sclerosis diagnosed at the University Hospital Clementino Fraga Filho (Federal University of Rio de Janeiro) between 1986 and 1994 were identified. They were studied on clinical, morphological and immuno-histochemical grounds. Clinically, the disease was characterized by the young age of the patients, mediastinal involvement by bulky disease and compressive symptoms. None of the patients had evidence of extra-thoracic disease as presentation. On morphological grounds they had evidence of extra-thoracic disease at presentation. On morphological grounds they showed a mixture of immuno blasts and large follicular enter cell with sclerosis. Three of five cases proved to be of B-cell origin. Four of five patients were treated with chemotherapy. Cases 1 and with MACOP-B, and cases 3 and 4 with Pro-MACE-cytaBOM and consolidation radiation therapy. All the patients achieved a complete remission, and are alive, free of disease, with a follow-up of 1 to 8 years. (author). 28 refs., 8 figs., 2 tabs.

  19. 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 )

  20. REGULACION DEL METABOLISMO DEL GLUCOGENO TESTICULAR Y SU POSIBLE RELACION CON APOPTOSIS DE CELULAS GERMINALES MASCULINAS

    OpenAIRE

    VILLARROEL ESPINDOLA, FRANZ DOMINIK

    2012-01-01

    El glucógeno es la principal fuente de glucosa para muchos procesos biológicos. Sin embargo, esta molécula podría tener otras funciones, incluso tener efectos negativos sobre la célula. La enzima limitante en la síntesis de glucógeno es la glucógeno sintasa (GS). Es codificada por dos genes, GYSI, expresada en músculo (isoforma muscular, MGS) y otros tejidos, y GYS2, expresada mayoritariamente en hígado (isoforma hepática, LGS). La expresión de GS y su actividad han sido amplia...

  1. 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)

  2. DINAMIC MITOCONDRIAL EN LA REGULACION DEL METABOLISMO DE GLUCOSA DEPENDIENTE DE INSULINA EN CELULAS MUSCULARES ESQUELETICAS

    OpenAIRE

    DEL CAMPO SFEIR, ANDREA ESTEFANIA

    2013-01-01

    El principal objetivo del metabolismo energético es la generación de adenosina trifosfato (ATP) a través de la reducción de nutrientes tanto exógenos como endógenos. El músculo esquelético utiliza una amplia variedad de nutrientes para generar ATP dependiendo del estado en que se encuentre, variadas reacciones regulan la transformación de estos a combustible celular donde la señalización de insulina tiene un papel clave. La insulina es el principal regulador de la respuesta metabólica ...

  3. 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.

  4. DESARROLLO DE TECNOLOGIAS PARA EL CULTIVO DE CELULAS DE PIEL PARA TRANPLANTE AUTOLOGO

    OpenAIRE

    YOUNG A., MANUEL

    2003-01-01

    En Chile se estima que, cada año se ven afectadas 268.865 personas por quemaduras que requieren atención médica. De estos, 60.494 corresponden a quemaduras del tipo AB y B que requieren de tratamiento quirúrgico y posterior rehabilitación debido a su gravedad, dándose además frecuentemente la situación crítica de decesos. Otras lesiones severas de la piel la constituyen las ulceraciones, siendo la principal causa de amputación no traumática del pie. Para casos como quemaduras, el tratamien...

  5. 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.

  6. 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

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

    OpenAIRE

    Carolina Salazar Holguín

    2013-01-01

    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 proteg...

  8. ESTUDIO FISICOQUIMICO DE LA FORMACION, HIDROLISIS Y ESTABILIDAD DE BASES DE SCHIFF DERIVADAS DE 5'-FOSFATO DE PIRIDOXAL.

    OpenAIRE

    BASAGOITIA GONZALEZ, ANDREA INES

    2002-01-01

    En este trabajo se han realizado los estudios cinéticos para las reacciones de 5-fosfato de piridoxal con L-triptófano, éster metílico de L-triptófano y éster butílico de L-triptófano, a 25°C y u 0.1 M, en un amplio intervalo de pH. Además, para el sistem 103p.

  9. 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.

  10. 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.

  11. 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

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

    OpenAIRE

    2011-01-01

    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 rel...

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. Las acciones civiles derivadas del daño ambiental en la ley nº 19.300

    OpenAIRE

    Vidal Olivares, Álvaro

    2007-01-01

    Un daño ambiental puede producir como consecuencia directa e inmediata un daño civil, y él da lugar a las acciones de responsabilidad ambiental y de indemnización ordinaria. La Ley Nº 19.300 prevé un régimen básico de común aplicación a ambas, que hace excepción a las normas del Derecho común . Entre los legitimados activos para la acción ambiental se cuentan las personas naturales o jurídicas que hayan sufrido un daño ambiental; y tiene por primer objeto una prestación de hacer: la reparació...

  18. Expresión de las moléculas del Complejo Mayor de Histocompatibilidad clase II y moléculas co-estimuladoras en carcinomas orales in vitro

    OpenAIRE

    Villarroel, Mariana; Speight, Paul M.; Barrett, A. William

    2005-01-01

    El descubrimiento de que el epitelio escamoso estratificado que cubre la mucosa oral podia expresar moleculas del Complejo Mayor de Histocompatibilidad clase II en varias condiciones patologicas de tipo inflamatorio abrio la posibilidad de que los queratinocitos orales sean celulas inmunologicamente activas, las cuales pueden funcionar con .celulas presentadoras de antigenos'ñ. Para una efectiva activacion de los linfocitos T, las celulas presentadoras de antigenos requie...

  19. 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.

  20. 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.

  1. 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.

  2. The reformation of ethanol and application to fuel cells; A reforma do etanol e sua aplicacao em celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ennio Peres da; Camargo, Joao Carlos [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mails: lh2ennio@ifi.unicamp.br; joaoc@fem.unicamp.br; Carolino, Iaponira Rando [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Quimica]. e-mail: yaponira@hotmail.com

    2002-07-01

    This paper presents the perspectives for using of ethanol (EtOH) obtained from the sugar cane for electric power production, through a integrated system constituted by a hydrogen generator, by using the ethanol reforming associated to a fuel cell feed with the produced hydrogen. The paper also focuses the present re-structuration of the Brazilian electric sector identifying the possibility of implantation that system.

  3. 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)

  4. 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)

  5. The electrical behaviour of commercial solar cells under low concentration; Comportamiento electrico de celulas solares comerciales a baja concentracion

    Energy Technology Data Exchange (ETDEWEB)

    Martin, N.; Chenlo, F.

    2004-07-01

    The aim of this work is to analyse the electrical behaviour of commercial solar cells under low concentration. It is important to know the ideal concentration and temperature range that can be applied.. For that purpose we have tested the electrical characteristic of several solar cells of different technologies. The temperature during testing has been controlled (25, 40, 55 y 70 degree Celsius) and also the irradiance among 250 W/m (0,25X) and 2500 W/m2 (2,5X). The efficiency curves versus temperature show a maximum near 1000W/m and a decrease tendency caused by the serial resistance of the solar cell. The influence of temperature also function of the irradiance. (Author)

  6. 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)

  7. INGENIERIA DE PROTEINAS DE UAN BETA-1,3-ENDOGLUCANASA LITICA CAPAZ DE PERMEABILIZAR CELULAS DE LEVADURA

    OpenAIRE

    OLIVERA NAPPA; ALVARO MARIA

    2005-01-01

    La endo-Beta ,3-glucanasa Bgl ll de C. cellulans (O. xanthineolytica) se presenta como una buena alternativa para ser utilizada como enzima modelo de un grupo amplio de glicosil hidrolasas, por lo que los estudios efectuados sobre ella pueden ser fácilmente extrapolables a otras enzimas, dentro de las cuales pueden contarse enzimas de claro interés industrial. Muchos procesos biotecnológicos en los que estas enzimas pueden ser de utilidad operan bajo condiciones de pH no óptimas para su acti...

  8. Electrochemical characterization of proton exchange membrane fuel cells; Caracterizacao eletroquimica de celulas a combustivel de membrana polimerica trocadora de protons

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Jose Geraldo de Melo; 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

    This paper describes the electrochemical behavior of a proton exchange membrane fuel cell in function of temperature and time of operation. Different polarization phenomena are considered in the 30 to 70 deg C temperature range, as well as the degradation of electrochemical behavior of the fuel cell analyzed up to 1260 hours of operation. The results show that there is a tendency for the experimental values approaching the theoretical as it increases the temperature of the membrane electrolyte. The electrochemical behavior of the PEMFC studied proved to be less stable at 70 deg C. On the other hand, at 30 deg C the fuel cell performance proved to be considerably lower than at other temperatures. Also, it was found that in certain current ranges occurs greater overlay in potential-current curves, and in some cases reversing between these curves depending on the electric current required for the data obtained at 60 and 70 deg C, indicating, perhaps, that at 70 deg C the characteristics of the electrolyte are slightly inferior to those at 70 deg C, corresponding to an electrolyte degradation. Additionally, for the system studied, we found that the rate of variation of the potential difference in function of the temperature is quite high at the beginning of the operation process and tends to stabilize in a level of around 2,3-2,5 {mu}V per minute for times greater than 330 hours of operation. (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. 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)

  11. 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)

  12. 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.

  13. 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)

  14. 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)

  15. DESREGULACION DE LA ACTIVIDAD DEL FACTOR DE TRANSCRIPCION NF-KB MEDIADA POR CALCIO EN CELULAS MUSCULARES DISTROFICAS MDX

    OpenAIRE

    ALTAMIRANO FULLA, FRANCISCO JAVIER; ALTAMIRANO FULLA; FRANCISCO JAVIER

    2012-01-01

    La Distrofia Muscular de Duchenne (DMD) es una enfermedad genética recesiva,ligada al cromosoma X, que afecta a 1 de cada 3500 hombres nacidos. La causa de esta enfermedad es la mutación del gen de la distrofina en humanos y en ratones mdx (modelo animal de DMD). La DMD es una enfermedad progresiva que se caracteriza por daños en la membrana de las fibras musculares, infiltración de células inmunes en el músculo,inflamación crónica, daño de sarcómeros, muerte celular y degeneración severa del...

  16. Technical analysis of fuel cells applied to cogeneration systems; Analise tecnica de celulas combustivel aplicadas em sistemas de cogeracao

    Energy Technology Data Exchange (ETDEWEB)

    Pulgar, Rafael Girardi; Bazzo, Edson [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica]. E-mails: rafael@cet.ufsc.br; ebazzo@emc.ufsc.br; Martinac, Ivo [KTH - Royal Institute of Tech., Stockholm (Sweden). Dept. of Energy Technology]. E-mail: im@egi.kth.se

    2002-07-01

    In the last years the fuel cell technology has been pointed out as a promising alternative for electricity generation. Compared to conventional energy conversion processes it presents great advantages, such as high efficiency, low gases emissions and the possibility to be applied in cogeneration systems, among others. The fuel cell converts the chemical energy of the fuel directly into electricity via an electrochemical process. The waste heat generated in the process can be recovered in cogeneration applications. In this article, preliminary results related to a Phosphoric Acid Fuel cell (PAFC) applied to hotels for power generation and hot water production are presented. The PAFC shows an electrical efficiency of about 40 per cent for power generation. In the cogeneration system proposed in this work, the global thermoelectric efficiency increased up to 73 per cent, when both electrical and thermal energy are considered. (author)

  17. Aspectos cineticos e operacionais da fermentação alcoolica continua em fermentador cascata com celulas livres e imobilizadas

    OpenAIRE

    Aldo Alessandro Milanese Rubilar

    1987-01-01

    Resumo: Foram realizadas fermentações contínuos da levedura Saccharomyces cerevisiae IZ 888 ruim reator multiestágio com células imobilizadas, operando a 33°C e pH entre 2,5 - 3,0. Foi utilizada a técnica de imobilização por adsorção, usando como suporte cubos de 5x5x5 mm de esponja de polietíleno de alta densidade, em leito empacotado. A fim de conseguir características tipo CSTR, cada reator foi dotado de uma bomba centrífuga para recirculação interna . O sistema consta de 6 reatores em ser...

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

    OpenAIRE

    Arcay,Lucila; Bruzual,Elizabeth

    1986-01-01

    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 to...

  19. 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)

  20. 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)

  1. Use of fuel cells in residences and commercial establishments; Uso de celulas combustiveis em residencias e estabelecimentos comerciais

    Energy Technology Data Exchange (ETDEWEB)

    Serra, Eduardo T. [Centro de Pesquisas de Energia Eletrica, Rio de Janeiro, RJ (Brazil)

    2003-05-01

    This paper analyses the present technological stage and the economical feasibility of the application of low power fuel cells for meeting of the residence and small commercial units electric power consumption needs.

  2. REGULACION DE LA DINAMICA Y METABOLISMO MITOCONDRIAL POR INCRETINA GLP-1 EN CELULAS DE LA LINEA A7R5

    OpenAIRE

    TORRES RIVERA, GLORIA ANDREA

    2014-01-01

    El péptido similar a glucagón-1 (GLP-1) es una incretina secretada por las células intestinales. Su acción clásica es regular la respuesta secretoria de insulina por el páncreas. Sin embargo, recientemente se ha descrito que GLP-1 posee acciones extrapancreáticas muy similares a la insulina, con mecanismos de señalización tejido-específicos. Por sus muchas acciones fisiológicas, y la mayoría relacionadas con los efectos insulinotrópicos de esta incretina, derivados peptidomiméticos de G...

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

    OpenAIRE

    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...

  4. Terapia génica dirigida en una nuevo "sitio seguro" en células progenitoras hematopoyéticas humanas para su aplicación en anemia de Fanconi

    OpenAIRE

    Rodríguez Fornés, Fátima

    2016-01-01

    La anemia de Fanconi es una enfermedad hereditaria de baja prevalencia, descrita por primera vez por el pediatra Guido Fanconi en 1927. Esta enfermedad se produce como consecuencia de mutaciones en cualquiera de los 19 genes de Fanconi descritos hasta la actualidad, y que participan en la ruta de Fanconi/BRCA. Esta ruta se encarga de la reparación de enlaces intercatenarios del ADN y de coordinar los distintos mecanismos de reparación de las dobles roturas en el ADN. La anemia de Fanconi está...

  5. 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)

  6. 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)

  7. 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)

  8. 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].

  9. Estudio del comportamiento de la función a partir de la derivada. Análisis de una secuencia didáctica

    OpenAIRE

    Engler,Adriana; Vrancken,Silvia; Gregorini, María Inés; Müller, Daniela; Hecklein, Marcela; Henzenn, Natalia

    2008-01-01

    La preocupación por mejorar el aprendizaje del cálculo en una carrera universitaria no matemática conduce a la reflexión sobre las metodologías empleadas para su enseñanza. Por esto, desde hace tiempo trabajamos en el proyecto de investigación “Errores y dificultades: organizadores didácticos en el aprendizaje del cálculo en carreras no matemáticas”. En el marco del mismo diseñamos una secuencia de actividades para favorecer el desarrollo del pensamiento variacional y sus aplicaciones en el e...

  10. 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.

  11. 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».

  12. Macromoléculas anfifílicas derivadas de la polietilenimina hiperramificada: caracterización estructural y aplicaciones en nanociencias

    OpenAIRE

    Picco, Agustín Silvio

    2014-01-01

    Esta tesis se enfoca en la realización de un estudio sistemático y multi-técnica respecto de la estructura e interacción, con distintas entidades, de CAMs tipo HPEI-Cn, sintetizadas a través de los enfoques c y d. Las características estructurales y las propiedades supramoleculares de estos sistemas fueron estudiadas en estado sólido (capitulo 1), solución/suspensión (capitulo 2) y en interfases aire-agua (capitulo 3). Por otro lado, la capacidad de interacción de HPEI-Cn fue investigada con ...

  13. Investigação da etiologia de malformações craniofaciais com uso de células derivadas de crista neural

    OpenAIRE

    2016-01-01

    As malformações craniofaciais (MCFs) compreendem uma vasta e heterogênea gama de doenças que envolvem o acometimento de tecidos do crânio e da face, sendo que indivíduos afetados enfrentam morbidade e deficiências funcionais relevantes. O entendimento da etiologia das MCFs é de extrema importância, pois poderá levar ao desenvolvimento ou melhoria de estratégias preventivas e terapêuticas. As MCFs são oriundas principalmente de distúrbios no desenvolvimento da crista neural cranial e seus deri...

  14. PERCEPCIÓN DE ALIMENTOS EN EL PRIMER LUSTRO DE VIDA: ASPECTOS INNATOS, CAUSALIDAD Y MODIFICACIONES DERIVADAS DE LA EXPERIENCIA ALIMENTARIA

    Directory of Open Access Journals (Sweden)

    Alejandro Chacón Villalobos

    2011-01-01

    Full Text Available Este 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.

  15. Análisis de la culpa en el incumplimiento de las obligaciones derivadas del contrato de prestación de servicios médicos

    OpenAIRE

    Betty Mercedes Martínez-Cárdenas

    2010-01-01

    A pesar de su fácil formulación, la distinción entre obligaciones de medios y de resultado para determinar el contenido de las obligaciones del galeno en el contrato de prestación de servicios médicos es insuficiente. Ella, para poder ser aplicada,  necesita además de la graduación de la culpa. Así, la antigua teoría de la prestación de las culpas se redescubre hoy como la manera más adecuada para determinar la intensidad del cuidado que el médico debe poner en el cumplimiento de su obligació...

  16. DESEMPEÑO PRODUCTIVO DE POLLOS DE ENGORDE SUPLEMENTADOS CON BIOMASA DE Saccharomyces cerevisiae DERIVADA DE LA FERMENTACIÓN DE RESIDUOS DE BANANO

    Directory of Open Access Journals (Sweden)

    N. M. Medina

    2014-01-01

    Full Text Available El objetivo de esta investigación fue evaluar el efecto de la inclusión de diferentes ni-veles de biomasa de levaduras, producidos al fermentar hidrolizados de residuos de laindustria bananera, sobre los parámetros zootécnicos de pollos de engorde, evaluandoademás el impacto económico de su uso en las dietas. Se utilizaron 210 pollos de en-gorde de un día de edad, distribuidos completamente al azar en cinco tratamientos,en una relación de seis réplicas por tratamiento y siete pollos por réplica. El periodoexperimental comprendió 42 días; el alimento y el agua se dispensaron a voluntad. Lasdietas experimentales fueron: T1- Control negativo sin levadura, T2- Control positivocon levadura comercial a razón de 1,5 kg ton-1de alimento, T3- Levadura experimentala razón de 0,5 kg ton-1de la dieta, T4-Levadura experimental a razón de 1,0 kg ton-1de la dieta y T5- Levadura experimental a razón de 1,5 kg ton-1de la dieta. Se observómayor consumo de acumulado alimento en el tratamiento 4 (1kg ton-1de levadura conrespecto a los demás tratamientos evaluados. No hubo diferencias significativas (P>0.05en las otras variables evaluadas en el estudio. Se constató beneficio económico con el usodel tratamiento 4 pues se obtuvieron mejores retornos (precio de venta del pollo – costode la alimentación que fueron mayores a los observados en los tratamientos 1, 2, 3 y 5en 153, 82, 62 y 161 pesos($ ave-1, respectivamente.

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

    OpenAIRE

    David Riascos; Francisco Guzmán; Efraín Buriticá; Mauricio Palacios; Martha Isabel Escobar; Hernán Pimienta

    2008-01-01

    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...

  18. AISLAMIENTO, CARACTERIZACIÓN Y POTENCIAL DE DIFERENCIACIÓN DE CÉLULAS MADRE MESENQUIMALES CANINAS DERIVADAS DE TEJIDO ADIPOSO

    Directory of Open Access Journals (Sweden)

    N. B. Riaño

    2014-01-01

    Full Text Available Se caracterizaron células obtenidas del tejido adiposo subcutáneo de caninos para demostrar su naturaleza de células madre mesenquimales (ad-MSCs. Las células se cultivaron y expan - dieron bajo condiciones in vitro . Se determinó la presencia de marcadores de superficie CD73, CD90 y CD105 por citometría de flujo y PCR en tiempo real, siendo idéntico el perfil de expresión obtenido al reportado en células madre mesenquimales humanas. Se demostró su potencial de diferenciación mediante análisis de expresión génica por PCR en tiempo real luego de inducirlas a procesos de diferenciación osteogénica y adipogénica. La capacidad de diferenciación osteogénica se evidenció a través de la expresión de genes de tejido óseo (colágeno tipo I y osteonectina en una cinética de expresión concordante con los eventos moleculares y celulares del desarrollo óseo in vivo . El potencial adipogénico se evaluó por la formación de vacuolas lipídicas intracelulares y la expresión del gen de lipoprotein-lipasa, acorde con el proceso in vivo . Se concluye que las células mesenquimales obtenidas del tejido adiposo de caninos cumplen los criterios morfológicos, de expresión de marcadores de superficie espe - cíficos y de capacidad de diferenciación mesodérmica, confirmando su naturaleza de células madre mesenquimales. Los resultados del presente trabajo indicaron que las ad-MSCs de los caninos son un excelente modelo preclínico para el desarrollo de aplicaciones en medicina regenerativa, tanto en medicina veterinaria, como en medicina humana.

  19. La prohibici??n de compensar las deudas derivadas de dep??sito y comodato (art. 1200, pfo. 1 C.C.)

    OpenAIRE

    Moreno-Torres Herrera, Mar??a Luisa

    1991-01-01

    El objetivo de la tesis es aclarar el significado del pfo, 1 del art. 1200 del c??digo civil espa??ol, que desde la publicaci??n de este ha planteado graves problemas interpretativos, agravados en la actualidad por la aplicaci??n del precepto en el ??mbito de los contratos bancarios. En el capitulo i se exponen las razones de la problem??tica que el art., suscita en nuestro derecho y sus diferencias con la de los c??digos de otros pa??ses. El capitulo II se ocupa de concretar la cuesti??n del...

  20. 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.

  1. Desenvolvimento de formas farmacêuticas de ação tópica com potencial antifúngico derivadas da cortiça

    OpenAIRE

    Mendes, Sandra Teresa de Oliveira

    2013-01-01

    Dissertação de mestrado em Biotecnologia Farmacêutica, apresentada à Faculdade de Farmácia da Universidade de Coimbra Os fungos apresentam características que os tornam organismos diferentes e, por isso, são classificados num reino à parte das plantas e dos restantes organismos. Podem apresentar dimensões consideráveis, como os cogumelos, ou muitas formas microscópicas, como bolores e leveduras. Diversas espécies instalam-se no corpo humano e podem causar várias doenças, tor...

  2. Un nuevo modelo para localizar instalaciones no deseables: ventajas derivadas de la integración de modelos de localización-asignación y SIG

    OpenAIRE

    Bosque Sendra, J.; Gómez Delgado, M.; F. Palm Rojas

    2006-01-01

    La localización de instalaciones no deseables es una tarea compleja en la que es necesario tener en cuenta varios objetivos. El más habitual es el de la eficiencia espacial, medido usualmente por la distancia existente entre estas instalaciones y la población y mediante el cual se pretende alejar lo máximo posible estas instalaciones de las zonas habitadas. Sin embargo, la consideración exclusiva de esta idea puede generar resultados muy poco convenientes desde otros puntos de ...

  3. 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.

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

    OpenAIRE

    Yurany Villada; Angelina Hormaza

    2015-01-01

    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...

  5. 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)

  6. 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.

  7. Calculation methods of reactivity using derivatives of nuclear power and Filter fir; Metodos para o calculo da reatividade usando derivadas da potencia nuclear e o filtro FIR

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Daniel Suescun

    2007-07-01

    This work presents two new methods for the solution of the inverse point kinetics equation. The first method is based on the integration by parts of the integral of the inverse point kinetics equation, which results in a power series in terms of the nuclear power in time dependence. Applying some conditions to the nuclear power, the reactivity is represented as first and second derivatives of this nuclear power. This new calculation method for reactivity has special characteristics, amongst which the possibility of using different sampling periods, and the possibility of restarting the calculation, after its interruption associated it with a possible equipment malfunction, allowing the calculation of reactivity in a non-continuous way. Apart from this reactivity can be obtained with or without dependency on the nuclear power memory. The second method is based on the Laplace transform of the point kinetics equations, resulting in an expression equivalent to the inverse kinetics equation as a function of the power history. The reactivity can be written in terms of the summation of convolution with response to impulse, characteristic of a linear system. For its digital form the Z-transform is used, which is the discrete version of the Laplace transform. In this method it can be pointed out that the linear part is equivalent to a filter named Finite Impulse Response (Fir). The Fir filter will always be, stable and non-varying in time, and, apart from this, it can be implemented in the non-recursive way. This type of implementation does not require feedback, allowing the calculation of reactivity in a continuous way. The proposed methods were validated using signals with random noise and showing the relationship between the reactivity difference and the degree of the random noise. (author)

  8. Comprensión del concepto de la derivada en su componente geométrica sobre la base del modelo de Pirie y Kieren

    OpenAIRE

    Londoño Londoño, Diana Lucía; Villa Chica, Diego Iván; Morales Ospina, Silvia Inés

    2013-01-01

    Actualmente, se evidencia una fuerte tendencia de la didáctica matemática por considerar las problemáticas que persisten en el aprendizaje propio de los conceptos de ésta área en términos de procesos cognitivos. Se aprecia una clara evolución y preocupación por analizar los errores y dificultades de tipo cognitivo que subyacen en los estudiantes en la comprensión de conceptos matemáticos. El presente trabajo de grado se enmarca en aquellos proyectos que tienen como línea de investigación l...

  9. QTLs y heterosis en jitomate en una población F2 derivada de una cruza interespecífica.

    OpenAIRE

    Hernández Bautista, Aurelio

    2013-01-01

    Para estudiar y aprovechar la diversidad genética de los parientes silvestres del jitomate (Solanum lycopersicum L.), es necesario seguir explorando nuevas fuentes de genes que puedan contribuir significativamente a la formación de variedades rendidoras y de alta calidad de fruto. De acuerdo con los resultados, se observó que los progenitores difieren significativamente (p < 0.05) en la mayoría de los caracteres, excepto en pH. Las variables peso, largo y ancho de fruto, días a floración y ma...

  10. "El elemento volitivo como determinante de la filiación derivada de las técnicas de reproducción asistida"

    OpenAIRE

    Lamm, Eleonora

    2008-01-01

    Los cambio provocados por las Técnicas de Reproducción Asistida en materia de filiación nos llevan a pensar que los criterios decisivos para la disciplina de la filiación (por naturaleza) han cambiado a compás de las mutaciones de la conciencia social. En este trabajo procuraré demostrar cómo la voluntad ha pasado a ser el elemento decisivo en la determinación de la maternidad y/o paternidad a partir del surgimiento y utilización de las Técnicas de Reproducción Asistida.

  11. Células-tronco derivadas do epitélio olfatório: perspectivas terapêuticas na medicina veterinária

    Directory of Open Access Journals (Sweden)

    Rosane Mazzarella

    Full Text Available Resumo: O epitélio olfatório (EO é uma fonte promissora de células-tronco (CTEO para o uso terapêutico na medicina veterinária e humana, especialmente em doenças correlacionadas com o sistema nervoso periférico (medula espinhal e central (cérebro e tronco encefálico , pois as CTEO possuem a capacidade de se diferenciar em células do sistema nervoso, tais como: neurônios, oligodendrócitos e astrócitos. Em humanos estas células são utilizadas em ensaios terapêuticos de doenças degenerativas como o Alzheimer e Parkinson. Em animais a casuística relativa das doenças neurodegenerativas crônicas ou agudas é baixa, devido à dificuldade de diagnóstico definitivo, desta forma o enfoque das pesquisas com terapia celular são em sua grande maioria em lesões mecânicas na medula espinhal. Devido à falta de padronização e seleção das melhores metodologias que permitam confrontação de estudos, esta revisão busca reunir as mais recentes publicações, descrevendo o potencial uso das células-tronco do epitélio olfatório em terapias celulares, discutindo os principais desafios e perspectivas futuras com enfoque na medicina veterinária.

  12. 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.

  13. RESPONSABILIDAD POR LA ACTIVIDAD CONTRACTUAL ESTATAL DERIVADA DE LA NO ADJUDICACIÓN DE UN CONTRATO O DE SU ADJUDICACIÓN INDEBIDA. EVOLUCIÓN JURISPRUDENCIAL

    Directory of Open Access Journals (Sweden)

    Luis Alonso Rico Puerta

    2007-05-01

    Full Text Available La responsabilidad por la actividad contractual relacionada con la no adjudicación o adjudicación indebida de un contrato ha merecido de la jurisprudencia y la doctrina distintas posturas. En la jurisprudencial del Consejo de Estado se identifican tres posturas diferentes e incluso regresivas, que se han presentado desde el año 1998, en cuanto al porcentaje de la utilidad que se debe pagar a título de indemnización, la cual se fundamenta en la exclusión ilegal de un proponente en un proceso contractual o en la adjudicación de un contrato a quien no había formulado la mejor propuesta. Son esos cambios jurisprudenciales los que se pretenden abordan en este escrito

  14. 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.

  15. Cultivo de condrocitos sobre una matriz acelular derivada de membrana amniocoriónica. [Culture of chondrocytes on an acellular matrix derived from amniochorionic membrane

    OpenAIRE

    José Manuel Lucero; Alejandro Enrique Castiglioni; Paula Hovanyecz; R. M. Adrián Gorla; Oscar Berasategui; Griselda Valeria Fedrigo; Alicia Susana Lorenti

    2012-01-01

    Introducción El tejido cartilaginoso articular presenta escasa capacidad regenerativa.Existe alta incidencia de lesiones condrales en rodilla, especialmente de Grado II/III (Outerbridge). El uso combinado de células autólogas cultivadas con membranas biológicas, es una posibilidad terapéutica. El objetivo del presente trabajo es analizar las características del desarrollo in vitro de condrocitos humanos sobre membrana amniocoriónica acelular (MAC). Material y métodos Entre diciembre ...

  16. Células troncales derivadas del tejido adiposo: Técnica de obtención y utilidad en cirugía

    OpenAIRE

    MERUANE N,MANUEL; ROJAS R,MARIANA

    2011-01-01

    La cicatrización humana requiere de múltiples células inflamatorias, citoquinas, factores de crecimiento y células troncales mesenquimáticas, las cuales se encuentran en casi todos los tejidos adultos, principalmente en la médula ósea y tejido adiposo. Está demostrada la capacidad de diferenciación multilinaje de estas células, así como su participación en otros procesos al secretar factores paracrinos. En la siguiente revisión expondremos la técnica para obtener y cultivar células troncales ...

  17. M??todos asintoticos en ecuaciones en derivadas parciales originadas en teor??a cin??tica y cu??ntica

    OpenAIRE

    Nieto Mu??oz, Juan Jos??

    2001-01-01

    Esta tesis consta de una introducci??n general y cinco cap??tulos correspondientes a cinco trabajos de investigaci??n cuyo punto en com??m es su or??gen en la teor??a de semiconductores.En el segundo cap??tulo (primero tras la introducci??n)se analiza rigurosamente el l??mite de campo alto del sistema Vlasov-Poisson-Fokker-Plank (VPFP) cuando el recorrido libre medio t??rmico tiende a cero. Adem??s se analizan propiedades de existencia y unicidad del sistema l??mite obtenido dependiendo de la...

  18. Métodos asintoticos en ecuaciones en derivadas parciales originadas en teoría cinética y cuántica

    OpenAIRE

    Nieto Muñoz, Juan José

    2013-01-01

    Esta tesis consta de una introducción general y cinco capítulos correspondientes a cinco trabajos de investigación cuyo punto en comúm es su orígen en la teoría de semiconductores.En el segundo capítulo (primero tras la introducción)se analiza rigurosamente el límite de campo alto del sistema Vlasov-Poisson-Fokker-Plank (VPFP) cuando el recorrido libre medio térmico tiende a cero. Además se analizan propiedades de existencia y unicidad del sistema límite obtenido dependiendo de la dimensión e...

  19. La inscripción de la filiación derivada de la gestación por sustitución. Problemas actuales

    OpenAIRE

    Jiménez Martínez, María Victoria

    2012-01-01

    El artículo 10 de la LTRHA establece la nulidad de pleno derecho de los contratos de gestación por sustitución. Para evitar la aplicación de este precepto ciudadanos españoles han recurrido a otros ordenamientos jurídicos que admiten la posibilidad de que convertirse en padres del niño nacido de una mujer con la que se ha suscrito un contrato de “vientre de alquiler” y posteriormente solicitar la inscripción de la filiación a su favor en nuestro Registro Civil. En este trabajo se analiza la l...

  20. Painéis de partículas provenientes de rejeitos de Pinus sp. tratado com preservante cca e resina derivada de biomassa

    Directory of Open Access Journals (Sweden)

    Marília Silva Bertolini

    2014-04-01

    Full Text Available A utilização do preservante CCA (sais de cromo, cobre e arsênio tem sido questionada devido ao impacto relacionado à dispersão, principalmente, do cobre e do arsênio para o ambiente, antes de sua completa fixação na madeira. Outra questão se relaciona à disposição indevida dos resíduos provenientes da madeira tratada, viabilizando a lixiviação devido à maior área passível desses rejeitos sujeita a tal fenômeno. Este trabalho teve como objetivo a produção de painéis de partículas, avaliando o efeito da adição de resíduos de Pinus sp. tratado com sais de cromo, cobre e arsênio (CCA, em associação com material da mesma espécie sem preservantes, além de alterações no teor de adesivo poliuretano à base de mamona empregado na produção. As propriedades dos painéis produzidos foram determinadas conforme recomendações da NBR 14810-3: 2006. Por meio de análise estatística, observou-se que a adição da madeira tratada proporcionou desempenho superior no inchamento em espessura (2 h, ao passo que esse insumo utilizado na mesma proporção que a madeira sem preservantes foi significante, obtendo os melhores resultados na adesão interna. Os módulos de ruptura e de elasticidade na flexão não sofreram influência das variações nos insumos utilizados nos painéis. Os painéis, em grande parte, apresentaram-se em conformidade com os principais requisitos nesse âmbito, mostrando a possibilidade da utilização dos referidos insumos na produção, além da obtenção de um produto com considerável apelo ambiental.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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)

  6. 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)

  7. Conductor polymeric membranes with potential for application in PEM type fuel cells; Membranas polimericas condutoras com potencialidades para aplicacao em celulas a combustivel do tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Brioude, Michel de Meireles; Sodre, Livia Farias; Boaventura Filho, Jaime Soares; Jose, Nadia Mamede [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil)

    2006-07-01

    In this work two series of membranes were prepared; they were based on hybrid organic-inorganic or composite materials and presented potentiality for application in Proton Exchange Membrane Fuel Cell, PEMFC. The polymeric phase was constituted of poly(dimethylsiloxane), PDMS, crosslinked with tetra ethoxysilane, TEOS, with a 70%/30% ratio. Phosphotungstic acid (PWA) or the sodium monododecylsulphate (MDS), as proton conductors, were added to the inorganic network, close to the gel point; the mixtures were transferred to a cast. The films were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The membranes showed good properties, as flexibility, thermal and mechanical stability with potentiality to be used as conducting membranes in technological applications. (author)

  8. Analise da expressão genica das celulas mononucleares de sangue de cordão umbilical humano : implicação no ciclo celular

    OpenAIRE

    Angela Cristina Malheiros Luzo

    2005-01-01

    Resumo: A reconstituição da linhagem hematopoiética é um procedimento comum no tratamento de várias doenças hematológicas e não hematológicas. A medula óssea tem sido a principal fonte de obtenção de células tronco nos últimos 50 anos. Recentemente, células tronco obtidas de sangue periférico pós-mobilização e células mononucleares de sangue de cordão umbilical humano têm sido utilizadas com sucesso. Entretanto, as células tronco parecem ter características diferentes. Vários estudos foram pu...

  9. 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)

  10. Photovoltaic cells using blends of poly aniline-DBSA and EPDM; Celulas fotovoltaicas utilizando blendas de polianilina-DBSA e EPDM

    Energy Technology Data Exchange (ETDEWEB)

    Carinhana Junior, Dermeval; Faez, Roselena; Paoli, Marco-Aurelio de [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica]. E-mail: derms@iqm.unicamp.br

    1999-07-01

    This paper reports the construction of totally solid photoelectrochemical devices using the PANI-DBSA/EPDM blend and a polymeric electrolyte. The blend presents itself as a photoactive material that can be obtained in a large scale although the observed low efficiency.

  11. Modulação de MAPKs em celulas de leucemia humana induzidas a apoptose e diferenciação

    OpenAIRE

    Alexandre Donizeti Martins Cavagis

    2005-01-01

    Resumo: O objetivo central deste trabalho foi avaliar a modulação de MAPKs em células de leucemia humana induzidas a apoptose e diferenciação. No capítulo 1, estudou-se o efeito da tetrahidroxiquinona (THQ), uma molécula que pode participar de um ciclo redox formando radicais semiquinona e, conseqüentemente, espécies reativas de oxigênio (EROs). A citotoxicidade da THQ, mediada pela formação de EROs, foi revertida por tratamento das células com glutationa e N-acetil-L-cisteína. A produção de ...

  12. An approximated method of calculation of neutron spectra in reactor cells; Um metodo aproximado de calculo do espectro de neutrons em celulas de reatores

    Energy Technology Data Exchange (ETDEWEB)

    Caldeira, Alexandre D. [Centro Tecnico Aeroespacial (CTA-IEAv), Sao Jose dos Campos, SP (Brazil). Inst. de Estudos Avancados

    2000-07-01

    This work deals with the cell neutron spectra calculated with the transport equation for an infinite medium applied to the homogenized cell. Considering a radioisotope production reactor fuel cell, as a sample case, the maximum deviation found between the approximated and the S{sub N} methods was 13%. (author)

  13. 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)

  14. 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)

  15. Direct methanol fuel cells: Pt-Ni/C binary electrocatalysts; Celulas a combutivel de metanol direto: eletrocatalisadores binarios de Pt-Ni/C

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, Jose Ricardo Cezar; Antolini, Ermete; Santos, Ana Maria dos; Gonzalez, Ernesto Rafael [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica], e-mail: salgado@iqsc.usp.br

    2004-07-01

    Direct methanol fuel cells use platinum alloys as more efficient catalysts than platinum. In the case of binary alloys, the second metal affects several properties of platinum, like the interatomic distance, the electronic density and the capacity of forming oxygenated species at lower potentials. In this work, Pt-Ni catalysts supported on high surface area carbon (Pt-Ni/C) were prepared and characterized, and tested as catalysts in the anode and the cathode in direct methanol fuel cells. In both cases the performance of the material was better than that of Pt/C, and comparing the two situations it was better when the material was used in the cathode. The improved performance in the cathode was attributed to the nickel that forms a true alloy with platinum, while the better performance in the anode was attributed to the presence of nickel oxides. (author)

  16. 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)

  17. 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)

  18. EFECTO DEL TIPO Y CONCENTRACION DE LA FUENTE DE CARBONO SOBRE LA SINTESIS Y GLICOSILACION DE TPA PRODUCIDO EN CELULAS CHO

    OpenAIRE

    Berrios, Julio

    2008-01-01

    Los cultivos de células animales han sido ampliamente usados en el último tiempo para la producción de proteínas con uso terapéutico, debido a su habilidad de realizar modificaciones post-traduccionales, incluyendo la glicosilación. La glicosilación de la proteína ha mostrado ser esencial para conseguir la actividad biológica deseada. Sin embargo, dada la alta complejidad de estos sistemas, el conocimiento acerca de los procesos metabólicos y los mecanismos que afectan la producción es aún...

  19. 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)

  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. Manganates of lanthanum and strontium as cathode of fuel cells (SOFC); Manganatos de lantanio e estroncio como catodo de celulas combustiveis (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Marfran C. de; Nascimento, Rubens M. do; Martinelli, Antonio E.; Melo, Dulce M.A. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2004-07-01

    The fuel cells if constitute currently as a promising alternative modular generation of electric energy to leave of chemical energy. The SOFCs is distinguished as promising for the industry of the oil, therefore they can use the produced natural gas in the platforms as combustible, allowing generation of raised power electric.The material of cathode constituent of the cell are oxides with perovskites structure, normally doped with a earthy-alkaline element (Sr{sup +3}). In this work, two compositions of the La{sub 1-x}Sr{sub x} MnO{sub 3} system were synthesized (x = 0,15 and 0,30), through the Pechini method and after resultants of the process they were characterized by X- Ray diffraction, Fourier-transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TG/DTG) and laser grain size analysis. The systems in study shown similar behavior how much to the results of absorption in the region of infra-red ray and TG/DTG, therefore if it can prove the loss of organic substance with the increase of the temperature.The average particle diameter for the two systems also increased gradually with the temperature. In general way the synthesis method was satisfactory for the formation of the perovskites phase in the two studied compositions. (author)

  2. 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)

  3. 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.

  4. EFECTO DE LA SOBRECARGA DE HIERRO SOBRE LA ACTIVACION DE INF-KB EN CELULAS DE ENDOMETRIO HUMANO COMO POSIBLE MECANISMO ASOCIADO AL A PATOGENESIS DE LA ENDOMETRIOSIS

    OpenAIRE

    ALVARADO DIAZ, CARLOS PATRICIO

    2014-01-01

    La endometriosis es una enfermedad en la cual el tejido endometrial crece fuera de la cavidad uterina. El establecimiento de lesiones endometriósicas peritoneales se originaría a partir de células endometriales refluidas a través de las trompas uterinas durante la menstruación. Asociado al desarrollo de la enfermedad se encuentra un ambiente intraperitoneal pro-inflamatorio. Se ha visto que el factor de transcripción pro-inflamatorio nucelar factr-kappaB (NF-KB), en particular el dímero de NF...

  5. 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)

  6. 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)

  7. LA ENZIMA OCRL1 Y LAS PROTEINAS ENDOSOMALES, APPL1 Y WDFY2, PARTICIPAN EN EL TRAFICO DE MEGALINA EN CELULAS EPITELIALES RENALES

    OpenAIRE

    SANDOVAL GALARCE, LISETTE PAMELA

    2013-01-01

    Megalina es un receptor endocítico miembro de la familia de receptores de lipoproteínas de baja densidad (LDLR). Esta proteína se localiza en la superficie apical de varios epitelios y se expresa de manera importante en el epitelio de túbulo proximal renal. La principal función de megalina en el epitelio renal es la reabsorción de proteínas de bajo peso molecular desde el filtrado glomerular. Los ligandos de megalina incluyen calcio, albumina, insulina, leptina, hormona paratiroídea, angio...

  8. 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)

  9. Cogeneration, micro turbines and fuel cells: perspectives for distributed generation in Brazil; Cogeracao, microturbinas e celulas a combustivel: perspectivas para geracao distribuida no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Marco Antonio Haikal [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    Brazil has a large potential to install distributed generation systems, using natural gas or renewable like solar, wind or biomass energy. Regarding urban centers, natural gas fired cogeneration and other distributed energy technologies find economical applications. Cogeneration is defined as the generation of two kinds of useful energy from a single energy source. Usually, electrical energy and thermal energy as steam or hot water are produced. By using the absorption refrigeration cycle, chilled water can also be produced to be used in air conditioned systems, often called tri generation, a good alternative to industries, commercial buildings, shopping centers, hospitals, schools and universities. Micro turbines find utilization whenever natural gas is available, but not electricity, like gas compression installations, unmanned platforms or remote production fields. Fuel cells are used in systems requiring high levels of reliability or wherever the non availability cost is high. This paper describe technical and economical data related to PETROBRAS Research Center (CENPES) 3,200 kW electric energy and 1,000 RT chilled water cogeneration system, 200 kW fuel cell and 30 kW and 60 kW microturbines. (author)

  10. EFECTOS DE 2-METOXIESTRADIOL SOBRE LOS NIVELES DEL FACTOR TISULAR Y EL POTENCIAL INVASIVO DE LAS CELULAS DE CANCER DE MAMA

    OpenAIRE

    QUEZADA BRITO, MARISOL

    2009-01-01

    El 2-metoxiestradiol (2ME) es un metabolito del 17¡3-estradiol que ha emergido como un potencial agente para el tratamiento del cáncer, ya que inhibe la proliferación y suprime el crecimiento de tumores. Aunque se han propuesto varios blancos moleculares para explicar sus efectos, su mecanismo de acción aún es incierto. El estado hipercoagulante y la metástasis del tumor primario hacia los órganos vitales son las principales causas de muerte de los pacientes con cáncer. Se ha postulado que...

  11. 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)

  12. 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.

  13. 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)

  14. 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)

  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. 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.

  18. Analysis of the thermal and electrical behavior of commercial photovoltaic cells in inverse operation; Analisis del comportamiento termico y electrico de celulas fotovoltaicas comerciales en operacion inversa

    Energy Technology Data Exchange (ETDEWEB)

    Margineda, D.; Alonso-Garcia, M. C.; Sanchez-Friera, P.

    2008-07-01

    In order to analyse the thermal and electrical behaviour of commercial solar cells in reverse operation photovoltaic cells of the same type, but different class (different efficiency in the same type cell) were selected. electrical characterisation of the samples was performed through I-V curve measurements in direct and reverse bias, what gave information about the type of reverse I-V characteristics. besides, infrared characterisation showed temperature distributions along cell surface, pointing out localised heating that could cause hot-spots. From both characterisations (electrical and thermal) it is possible to obtain relations between the class of the cell, the type of reverse characteristics and maximum temperatures in case of partial shading or faulty operation. (Author)

  19. 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.

  20. 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.

  1. Efecto de la inhalacion del pentoxido de vanadio (V2o5) en la morfofisiologia de las celulas dendriticas (CD) del timo de raton /

    OpenAIRE

    Ustarroz Cano, Martha Luz

    2012-01-01

     tesis que para obtener el grado de Doctorado en Ciencias Biológicas, presenta Martha Luz Ustarroz Cano ; asesor Teresa Imelda Fortoul van der Goes62 páginas : ilustracionesDoctorado en Ciencias Biológicas UNAM, Facultad de Medicina, 2012

  2. 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)

  3. 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)

  4. Pre-surgical staging of renal cell carcinoma using imaging methods; Estadiamento pre-operatorio por imagem do carcinoma de celulas renais

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, Vivian Alvim; Bauab Junior, Tufik [Instituto de Radiodiagnostico Rio Preto, Sao Jose do Rio Preto, SP (Brazil); Barroso Junior, Ubirajara [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina. Div. de Urologia

    2000-04-01

    The incidental discovery of renal tumors has become more frequent lately. As a result, a more precise preoperative characterization of such tumors is necessary to allow the selection of the best treatment for each case, such as nepron-sparing surgery, radical nephrectomy, or immunotherapy. Computed tomography has been the most used imaging method to study these tumors. Large tumors, perinephric fat invasion, multicenter tumors, vascular invasion and stage IV are all computed tomography criteria which may exclude nephron-sparing surgery as a curative therapy. Furthermore there are some tomographic pitfalls in the detection of perinephric fat invasion and tumoral nodes. In this paper, the importance and accuracy of computed tomography for renal cancer staging is evaluated. (author)

  5. 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.

  6. Analysis of cogeneration system using fuel cell: cases study; Analise de sistema de cogeracao utilizando celula de combustivel: estudo de casos

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Jose Luz; Leal, Elisangela Martins [UNESP, Guaratingueta, SP (Brazil). Escola de Engenharia. Dept. de Energia]. E-mails: joseluz@feg.unesp.br; elisange@feg.unesp.br

    2000-07-01

    In this paper, a methodology for the study of a molten carbonate fuel cell cogeneration system associated to an absorption refrigeration system, for the electricity and cold water production, and applied to two establishments, is presented. This system permits the recovery of waste heat, available between 600 deg C e 700 deg C. Initially, some technical information about the most diffusing types of the fuel cell demonstration in the world are presented. In the next step, an energetic, exergetic and economic analysis are carry out, seeking the use of fuel cells, in conditions of prices and interest of Brazil. In conclusion, the fuel cell cogeneration system may have an excellent opportunity to strengthen the decentralized energy production in the Brazilian energy scene. (author)

  7. EFECTO DE PMA SOBRE UNA VARIANTE NUCLEAR DE CATEPSINA L Y LA ACTIVACION DEL FACTOR DE TRANSCRIPCION CDP/CUX EN CELULAS CACO-2

    OpenAIRE

    HERMOSILLA AGUAYO, VIVIANA ESTEFANIA

    2012-01-01

    El estudio de los mecanismos moleculares subyacentes al desarrollo del cáncer comprende el uso de compuestos capaces de actuar como promotores tumorales, los que favorecen la proliferación de células incompletamente transformadas. Dentro de ellos, uno de los más ampliamente utilizados es forbol 12-miristato 13-acetato o PMA. Los efectores a nivel celular de este compuesto corresponden a una familia de serina-treonina quinasas, conocidas como "Proteína quinasa C" o PKC, que partici...

  8. 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)

  9. 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)

  10. APOPTOSIS Y REPARACION DEL DAÑO CROMOSOMICO DURANTE G2 EN CELULAS DE PACIENTES CON SINDROME DE NIJMEGEN Y ATAXIA - TELANGIECTASIA

    OpenAIRE

    MARCELAIN CUBILLOS, KATHERINE JENNY

    2003-01-01

    El material genético de las células está expuesto a agentes endógenos y exógenos que causan lesiones en su estructura. La presencia de daño en el DNA, en particular, las fracturas bicatenarias, genero una condición de alta inestabilidad genómica, con el consecuente riesgo de transformación oncogénica. Las células cuentan con sistemas que detectan las lesiones en el DNA, los que desencadenan varios eventos río abajo que en su conjunto se denominan "respuesta al daño en el DNA". ...

  11. 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)

  12. The utilization of natural gas in the electricity production through fuel cell; A utilizacao do gas natural na geracao distribuida atraves de celulas combustiveis

    Energy Technology Data Exchange (ETDEWEB)

    Bernardi Junior, Paulo

    2004-07-01

    In function of the necessity of electric energy as input of vital importance for the development of the country, this work aims at to offer plus an energy alternative for Brazil. The exploitation of the natural gas reserves recently discovered can be made through modern methods that give as priority the distributed generation and the low ambient impact. All these aspects can be gotten with the use of fuel cell, working with the remodelled natural gas. Increased to the factor of a low ambient impact in the proper generation, the project suggests that the generating source can be located next the consumer, diminishing still more the problems generated for transmission lines, fuel transport, etc. The fuel cell has received a great attention in the international community and some models, some already in commercial period of training, they have shown excellent possibilities of capsize to be one of the future technologies in the generation of electric energy with low ambient impact. (author)

  13. 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)

  14. 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)

  15. 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)

  16. Fundamental aspects of the freezing of cells, with emphasis on mammalian ova and embryos. (Aspectos fundamentales de la congelacion de celulas, especialmente ovulos y embriones de mamiferos

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, P.

    1980-01-01

    For most cells there exists an optimum cooling rate. Both supraoptimal rates and suboptimal rates can be very damaging. The optimal rate varies enormously from less than or equal to 1/sup 0/C/min for mammalian preimplantation embryos to greater than or equal to 800/sup 0/C/min for the human red cell. Death at supraoptimal rates is the result of the formation of intracellular ice and its recrystallization during warming. Intracellular ice occurs when cells are cooled too rapidly to allow them to equilibrate by the osmotic withdrawal of intracellular water. The definition of too rapid depends chiefly on the size of the cell and its permeability to water. Death at suboptimal rates is a consequence of the major alterations in aqueous solutions produced by ice formation. The chief effects are a major reduction in the fraction of the solution remaining unfrozen at a given temperature and a major increase in the solute concentration of that fraction. Presumably, slow freezing injury is a consequence of one or both of these solution effects. The introduction of molar concentrations of protective solutes (additives) greatly reduces both the fraction frozen and the concentration of electrolytes in the unfrozen channels and in the cell interior. Usually, freezing either kills cells outright or it yields survivors that retain full capacity to function. Although there is the possibility that in some cases survivors may in fact be impaired genetically, all evidence indicates that genetic damage does not occur. But there are clear examples in which freezing does induce nonlethal physiological damage. Particularly striking examples are found in certain mammalian sperm.

  17. 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.

  18. CAMBIO FENOTIPICO DE LA CELULA DE LA MUSCULATURA LISA VASCULAR INDUCIDO POR PRODUCTOS DE GLICACION AVANZADA. PARTICIPACION DE LA NADPH OXIDASA.

    OpenAIRE

    SAN MARTIN ALMEYDA, MARIA ALEJANDRA

    2004-01-01

    Los productos de glicación avanzada (AGE) son un grupo heterogéneo de moléculas, resultado de la modificación covalente, irreversible y no enzimática de proteínas por glucosa. Los niveles plasmáticos y locales de AGE se encuentran aumentados en diabéticos 90p.

  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. 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.

  2. [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.

  3. [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.

  4. Propiedades inmunológicas de proteínas de fusión derivadas del virus de la Fiebre Aftosa expresadas en la superficie de Baculovirus y células de insectos

    OpenAIRE

    Taboga, Oscar; Tami, Cecilia; Carrillo, Elisa; Berinstein,Analía; Palma, Eduardo L

    2005-01-01

    En este trabajo se demuestra que es posible mejorar la inmunogenicidad de sitios antigénicos simples expresándolos sobre las membranas de células Sf9 o sobre la superficie de Baculovirus en ausencia de adyuvantes. Este hecho hace de este novedoso sistem a de presentación antigénica un método útil y seguro para el desarrollo de vacunas. El presente resumen pertenece a un trabajo financiado por la Academia Nacional de Agronomía y Veterinaria y de la Agencia Nacional de Promoción Científica y...

  5. 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.

  6. 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.

  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. Efecto del uso combinado de ácido hialurónico, plasma rico en plaquetas y células madre adultas derivadas de tejido adiposo en la reparación de defectos osteocondrales

    OpenAIRE

    Cervero Suárez, Francisco Javier

    2013-01-01

    El cartílago articular es un tejido que permite la trasmisión de fuerzas y el movimiento, y para ello presenta unas características entre las que destacan la baja celularidad y la ausencia de aporte sanguíneo, de terminaciones nerviosas y de drenaje linfático. Sin embargo, estas características son a la vez una limitación crucial para la reparación de los daños. En consecuencia, se han ido desarrollando en los últimos años diferentes terapias que tratan de mejorar la baja capacidad de regene...

  9. Efecto del uso combinado de ácido hialurónico, plasma rico en plaquetas y células madre adultas derivadas de tejido adiposo en la reparación de defectos osteocondrales

    OpenAIRE

    Cervero Suárez, Francisco Javier

    2016-01-01

    El cartílago articular es un tejido que permite la trasmisión de fuerzas y el movimiento, y para ello presenta unas características entre las que destacan la baja celularidad y la ausencia de aporte sanguíneo, de terminaciones nerviosas y de drenaje linfático. Sin embargo, estas características son a la vez una limitación crucial para la reparación de los daños. En consecuencia, se han ido desarrollando en los últimos años diferentes terapias que tratan de mejorar la baja capacidad de regene...

  10. 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...

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

    OpenAIRE

    Rochera Cordellat, Carlos; Villaescusa, Juan Antonio; Diazmacip Barroso, María Eugenia; Gil-Delgado Alberti, José Antonio; Toro Velasco, Manuel; Rico Eguizabal, Eugenio; Velázquez Martínez, David; Quesada de Corral, Antonio; Camacho González, Antonio

    2011-01-01

    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, rel...

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

    OpenAIRE

    Rochera, C.; J. A. Villaescusa; M.E. Díazmacip; Gil-Delgado, J. A.; Toro, M; Rico, E.; Velázquez, D.; Quesada, A; A. Camacho

    2011-01-01

    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, rel...

  13. Curvas-Guia Operacionais de Reservatório Sergipano Derivadas por Otimização Estocástica Implícita e Regressão Não Linear

    Directory of Open Access Journals (Sweden)

    José Amaury de Sousa Santos

    2016-04-01

    Full Text Available Este artigo apresenta o desenvolvimento e aplicação de curvas-guia operacionais de reservatórios de abastecimento, usando como estudo de caso a barragem do rio Poxim, em Sergipe, por meio da metodologia de otimização estocástica implícita suportada por análises de regressão (OEI-REG. O desempenho da OEI-REG é comparado com os da política de operação padrão de reservatórios (SOP: standard operating policy, da otimização determinística perante previsão perfeita de afluências futuras (ODPP e da programação dinâmica estocástica (PDE. A princípio, são empregados cem cenários de cem anos de vazões mensais para a calibração do modelo. Posteriormente, lança-se mão de cem novas séries de afluências visando a validação dos quatro procedimentos estudados. Os resultados indicam a viabilidade da utilização da OEI, tendo em vista sua menor vulnerabilidade em relação à SOP, assim como a proximidade de suas operações com as da ODPP. Comparando-se a OEI-REG com a PDE, percebe-se a curta distância entre os valores advindos de ambas, inclusive operações menos vulneráveis por meio da OEI-REG, justificando a adoção desta, por sua matemática simplificada em comparação com a PDE.

  14. "Best-sellers" en economía, una lectura desde la geografía económica. Derivadas en el paisaje, el medio y la ordenación del territorio

    Directory of Open Access Journals (Sweden)

    Manuel J. Marchena-Gómez

    2015-07-01

    Full Text Available En este artículo se utilizan las ideas de libros y manifiestos superventas editoriales y sus lecciones sobre la Geografía Económica internacional. Se hace un balance de los aportes de la denominada Nueva Geografía Económica y de su relación con los” best-sellers” en economía. Se ha tratado de poner en evidencia las novedades y recurrencias que sobre la Geografía Económica ejercen los autores de moda en Economía. Después de un método de selección atendiendo a criterios de venta electrónica y del interés mostrado por los medios de comunicación, se han elegido tres de éstos por su influencia y temática de interés para la Geografía Económica a escala global. Por fin, se han extraído conclusiones sobre el medio ambiente, el paisaje y la ordenación de territorio. En cualquier caso, existe un denominador común en la lectura de los textos: el rol creciente de las desigualdades territoriales y sociales en el mundo, la importancia de la calidad institucional en la interpretación de las mismas y en general, la necesidad de comunicación entre las ciencias sociales para comprender lo que pasa; más allá de aparatos formales sofisticados e irreales de índole economicista y considerados erróneamente objetos científicos en sí mismos.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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)

  18. 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...

  19. 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

    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.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.

  20. 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.

  1. Avaliação do potencial radiossensibilizador de uma tiossemicarbazona derivada de N(4)-Metil-Toluil-2-acetilpiridina e seu complexo de cobre sobre linhagens celulares de tumores cerebrais

    OpenAIRE

    2010-01-01

    A radioterapia é uma das principais abordagens terapêuticas utilizadas no tratamento do câncer e é indicada, principalmente, em casos onde as lesões são inoperáveis. No entanto, uma de suas limitações advém dos próprios efeitos biológicos da radiação, além de outros fatores tais como a radiorresistência inerente a alguns tipos tumorais, tais como os cerebrais. Então, a aplicação concomitante de agentes antineoplásicos com radioterapia vem sendo praticada na clínica de modo a maximizar o efeit...

  2. Desempenho das previsões de variáveis simples e derivadas obtidas pelo Modelo Global do CPTEC/COLA para alguns casos significativos ocorridos sobre o centro-sul do Brasil

    OpenAIRE

    Daniel Pires Bitencourt

    1996-01-01

    A introdução de modelos numéricos tornou possível fazer previsão de tempo com melhor confiabilidade e maior prazo de antecedência. A partir de Novembro de 1994, com a inauguração do CPTEC, o Brasil vem realizando previsões operacionais com seu modelo numérico, chamado Modelo Global do CPTEC/COLA. Em busca de melhores resultados é necessário aprimorar este modelo e, para isso, é preciso ter conhecimento do desempenho do mesmo. As estatísticas de desempenho são geralmente obtidas para previsões...

  3. 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.

  4. 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.

  5. Alocação de linhagens de milho derivadas das populações BR-105 e BR-106 em grupos heteróticos Allocation of maize lines from BR-105 and BR-106 populations to heterotic groups

    Directory of Open Access Journals (Sweden)

    Rogério de Melo Costa Pinto

    2001-09-01

    Full Text Available Os grupos heteróticos são importantes no melhoramento de milho, pois permitem o uso mais eficiente do germoplasma. Assim, o objetivo deste trabalho foi alocar linhagens de milho em grupos heteróticos a partir de estimativas da capacidade específica de combinação. Oito linhagens S3 da população BR-105 e dez da BR-106, foram cruzadas ao nível interpopulacional seguindo um sistema dialélico. Oitenta híbridos simples foram obtidos e avaliados em látices em três ambientes. Foram avaliados os caracteres produção de grãos (PG, altura da planta (AP e altura da espiga (AE. As estimativas das capacidades geral (CGC e específica (CEC de combinação foram obtidas segundo o método 4, modelo I de Griffing. A partir das estimativas de CEC, as linhagens foram alocadas aos respectivos grupos heteróticos utilizando-se o método UPGMA (média aritmética não ponderada para a construção do dendrograma e a dispersão gráfica pelo método das coordenadas principais. Para PG, as linhagens foram alocadas em quatro grupos heteróticos, sendo dois grupos em cada população. Para AP e AE, o uso das estimativas de CEC não foi eficiente para alocar as linhagens em grupos heteróticos. As análises de agrupamento e de coordenadas principais foram eficientes na alocação das linhagens em grupos heteróticos para PG. Então, como a produção de grãos é a principal característica para o melhoramento de milho, com a alocação das linhagens em quatro grupos heteróticos, os cruzamentos serão direcionados e o processo de melhoramento se tornará mais eficiente, evitando a obtenção e a avaliação de cruzamentos (híbridos desnecessários.The heterotic groups are important in maize breeding programs because they allow the most efficient use of the germoplasm. The objective of this research was to allocate maize lines to heterotic groups from estimates of specific combining ability (SCA. Eight and ten S3 lines derived from populations BR-105 and BR-106, respectively, were crossed at interpopulation levels following a diallel system. Eighty single-crosses were obtained and evaluated in lattice designs across three environments. Recorded data consisted of grain yield (GY, plant height (PH and ear height (EH. Estimates of general and specific combining ability (GCA and (SGA were computed according to Griffing's method 4, model I, for all traits. Estimates of SCA were used for principal coordinate analysis (PCO and for cluster analysis, by using UPGMA (unweighted pair-group method with arithmetical averages clustering algorithm, to assign the lines to heterotic groups. For the trait GY the lines were allocated to 4 heterotic groups, in which the lines from each population were subdivided in 2 heterotic groups. For the traits PH and EH, the use of the estimates of SCA to assign lines to heterotic groups were not efficient. Cluster analysis and principal coordinate analysis were efficient for the trait GY in allocating maize lines to heterotic groups. Thus, since grain yield is the main trait for the breeding purposes, with the allocation of the lines in 4 heterotic groups, the crosses will be more efficient, avoiding to obtain and evaluate unnecessary (hybrid crosses.

  6. Síntesis de constructos de multicopias peptídicas de secuencias derivadas de la proteína apical sushi protein (asp) de plasmodium falciparum: caracterización fisicoquímica y estudios de inmunogenicidad

    OpenAIRE

    Vanegas Murcia, Magnolia

    2014-01-01

    La malaria continúa siendo uno de los problemas de salud pública de mayor relevancia a nivel mundial. En la actualidad más del 40% de la población mundial que habita en las regiones tropicales y subtropicales son endémicas de esta enfermedad. Pese a las estrategias propuestas por entidades como la OMS y OPS, en el último año se registraron 216 millones de casos clínicos de malaria y cerca de 655.000 decesos por esta causa, mayoritariamente mujeres embarazadas y niños menores de cinco años de ...

  7. 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)

  8. 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.

  9. Protocolos de cuidados frente a doenças decorrentes de bioterrorismo Protocolos de cuidados frente a las enfermedades derivadas del bioterrorismo Care protocol for precautions against diseases caused by bioterrorist actions

    Directory of Open Access Journals (Sweden)

    Flávia Falci Ercole

    2003-08-01

    Full Text Available Epidemias conseqüentes a ações de bioterrorismo e medidas de prevenção e controle dessas infecções têm preocupado não só os governantes, mas, também, profissionais de saúde em geral. Profissionais de saúde devem reconhecer precocemente essas doenças. Informações e atualizações sobre o tema fazem-se necessárias. Este artigo traz uma revisão de literatura realizada na base de dados MEDLINE e LILACS, livros e informações online (referentes ao período de 1993 a 2001 sobre os aspectos epidemiológicos das principais doenças decorrentes do bioterrorismo e as recomendações de cuidados para o controle de infecção e minimização dos riscos ocupacionais. Os profissionais da enfermagem, que prestam assistência direta a pacientes, devem estar preparados para atender casos isolados ou aqueles ocorridos em epidemias.Las epidemias en consecuencia de las acciones bioterroristas y las medidas de prevención y control de estas infecciones son una preocupación no solamente de los gobernantes, sino también de los profesionales de salud en general. Los profesionales de salud deben reconocer con antelación estas enfermedades. Las informaciones y las actualizaciones sobre el tema, son fundamentales. El artículo trae una revisión de literatura realizada con base en datos MEDLINE y LILACS, libros e informaciones online (alusivo al periodo de 1993 a 2001 sobre los aspectos epidemiológicos de las principales enfermedades del bioterrorismo y las recomendaciones de los cuidados para el control de estas infecciones, además de minimizar los riesgos ocupacionales. Los profesionales de enfermería, que prestan atención directa al enfermo, deben estar preparados para atender los casos aislados o aquellos ocurridos en epidemias.Epidemics due to bioterrorist actions and prevention and control measures of these infections have been worrying not only the policy makers but also health professionals in general. Health professionals have to recognize these diseases earlier. Information and updated studies about the issue are needed. This study is a literature review in the MEDLINE and LILACS databases, books and online information (from 1993 to 2001 about epidemic aspects of the main diseases due to bioterrorist actions and care recommendations for infection control and occupational risk minimization. Healthcare professionals, who assist patients directly, should be prepared to assist patients who become ill in isolated or epidemic situations.

  10. Método de Landweber sem derivadas para identificação de parâmetros em equações diferenciais parciais elípticas

    OpenAIRE

    Alves, Maicon Marques

    2005-01-01

    Dissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Matemática e Computação Científica. Neste trabalho tratamos problemas de identificação de parâmetros em equações diferenciais parciais elípticas no caso em que conhecemos a sua respectiva solução. Este problema inverso \\'e tipicamente mal posto no sentido de Hadamard (a solução não depende continuamente dos dados). Nesse sentido, alguma técnica de regulari...

  11. 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)

  12. 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.

  13. 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.

  14. Responsabilidad por la actividad contractual estatal derivada de la no adjudicación de un contrato o de su adjudicación indebida. Evolución jurisprudencial

    OpenAIRE

    Luis Alonso Rico Puerta

    2011-01-01

    La responsabilidad por la actividad contractual relacionada con la no adjudicación o adjudicación indebida de un contrato ha merecido de la jurisprudencia y la doctrina distintas posturas. En la jurisprudencial del Consejo de Estado se identifican tres posturas diferentes e incluso regresivas, que se han presentado desde el año 1998, en cuanto al porcentaje de la utilidad que se debe pagar a título de indemnización, la cual se fundamenta en la exclusión ilegal de un proponente en un pro...

  15. Las aglomeraciones urbanas y los impuestos: algunas ideas derivadas de la aplicación de la curva de Laffer al impuesto sobre la renta español en diferentes escenarios espaciales

    Directory of Open Access Journals (Sweden)

    Laura Varela-Candamio

    2017-01-01

    Full Text Available Antecedentes: La búsqueda de las tasas impositivas óptimas ha sido recurrente en las discusiones de política fiscal. En particular, la relación entre la estructura tributaria y el crecimiento económico ha hecho resurgir la hipótesis de Laffer que implica la existencia de una relación parabólica entre el nivel de impuestos y los ingresos obtenidos. Nuestra hipótesis es que las zonas urbanas tienen un impacto igualmente significativo sobre la disposición a pagar impuestos y puede existir igual o más heterogeneidad entre los tamaños urbanos que entre los dife- rentes territorios. Metodología: En este artículo se contrasta la hipótesis de Laffer para el caso español utilizando microdatos del Instituto de Estudios Fiscales ( IEF para el año 2009 en diferentes escenarios espaciales. Para ello, se utiliza una muestra de declaran- tes de corte transversal estimada con mínimos cuadrados ordinarios. Resultados: La presencia de una relación parabólica entre la carga tributaria y la recaudación de impuestos permite obtener una tasa impositiva que maximiza los ingresos fiscales en torno a 30%, el doble del promedio aplicado. Por regiones, hemos observado variaciones importantes que justifican la existencia de un alto grado de descentralización fiscal. Pero esta variabilidad es también importante según el tamaño de las ciudades. Los ingresos fiscales máximos de las dos princi- pales ciudades, Madrid y Barcelona, se obtienen con una tasa impositiva de 34%, mientras que todas las demás ciudades alcanzan el máximo de ingresos fiscales a tasas similares. Conclusiones: Cuanto menor es el tamaño de la ciudad, menor es la tasa impositiva que maximiza los ingresos fiscales, abriendo una brecha más grande cuanto más pequeña es la ciudad.

  16. 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.

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

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    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.

  18. La responsabilidad civil derivada de los daños ocasionados al derecho al honor, a la intimidad personal y familiar y a la propia imágen

    OpenAIRE

    Rovira-Sueiro, María E.

    2011-01-01

    [Resumen] SE ANALIZA LA RESPONSABILIDAD CIVIL EN EL AMBITO ESPECIFICO DE LOS DERECHOS AL HONOR, INTIMIDAD E IMAGEN COMPARANDOLA CON EL REGIMEN COMUN DE RESPONSABILIDAD CIVIL CONTENIDO EN EL ARTICULO 1902 DEL CODIGO CIVIL.

  19. 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)

  20. 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.

  1. Percepción de los profesionales de la salud sobre las creencias y las tradiciones derivadas del Islam como barreras a la donación de órganos en Argelia

    Directory of Open Access Journals (Sweden)

    Nouhad Laidouni

    2017-03-01

    Conclusión: Existe confusión entre la población argelina sobre la postura del Islam en torno a la donación y el trasplante de órganos, que perjudica fundamentalmente a la tasa de donación cadavérica. La colaboración entre el sector sanitario y las figuras religiosas para sensibilizar a la población podría contribuir a mejorar la disposición de la población a donar sus órganos no solo en vida.

  2. 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

    Directory of Open Access Journals (Sweden)

    Ana Dolores Canga Armayor

    2006-03-01

    Full Text Available 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 comportamiento de Crichton Royal (CRBRS, valoración de la piel, estado nutricional, riesgo caídas, secreciones vías aéreas. Resultados: El grupo control aumenta la puntuación en la escala de Crichton Royal, mientras que disminuye en el grupo intervención (p= 0,02. Conclusiones: La intervención fue efectiva.Hospitalisation of the elderly can result in the lost of physical and cognitive skills. Research Question: Does a standardised nursing intervention with elder patients who are admitted in acute wards reduce complications from hospitalisation? Study design: Experimental study with a control group (18 cases and an intervention group (13 cases. Participants (older than 70 years were randomly allocated in the two groups. Standardised intervention. Measurements took place at admission and discharge. Measurement was made through: The Crichton Royal Behaviour Scale (CRBRS, assessment of skin, nutritional status, risk of falls, and presence of mucus in airways. Findings: The control group obtained significantly higher scores in the Crichton Royal Behaviour Scale (p= 0.02 than the intervention group. Conclusion: The intervention was effective.

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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)

  8. 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.

  9. Treatment of transparent conductive oxides by laser processes for the development of Silicon photovoltaic cells; Tratamiento de oxidos conductores transparentes por procesos laser para el desarrollo de celulas fotovoltaicas de silicio

    Energy Technology Data Exchange (ETDEWEB)

    Canteli Perez-Caballero, D.

    2015-07-01

    Transparent conductive oxides (TCOs) are heavily doped oxides with high transparency in the visible range of the spectrum and a very low sheet resistance, making them very attractive for applications in optoelectronic devices. TCOs are widely found in many different areas such as low emissivity windows, electric contacts in computers, televisions or portable devices, and, specially, in the photovoltaic (PV) industry. PV industry is mainly based on mono- and multicrystalline silicon, where TCOs are used as anti-reflective coatings, but the search for cheaper, alternative technologies has led to the development of thin film PV technologies, where TCOs are used as transparent contacts. With the maturation of the thin film PV industry, laser sources have become an essential tool, allowing the improvement of some industrial processes and the development of new ones. Because of the interest on a deeper understanding of the interaction processes between laser light and TCOs, the laser ablation of three of the most important TCOs has been studied in depth in the present work. (Author)

  10. 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)

  11. 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)

  12. 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)

  13. 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.

  14. 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)

  15. 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)

  16. 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)

  17. 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)

  18. 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)

  19. 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.

  20. PAPEL DEL INHIBIDOR DE LA VIA DE FACTOR TISULAR Y CAVEOLINA-1 SOBRE EL POTENCIAL INVASIVO Y LA ACTIVIDAD PROCOAGULANTE DE LAS CELULAS DE CANCER DE MAMA Y ENDOMETRIO.

    OpenAIRE

    HERNANDEZ BARRERA, SOLEDAD PAOLA

    2009-01-01

    El Factor tisular (FT) es una glicoproteína de transmembrana que inicia la vía extrínseca de la cascada de coagulación y actúa como receptor y cofactor enzimático del factor VII. Además el FT ha sido directamente relacionado con la agresividad del cáncer. 96p.

  1. 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)

  2. 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)

  3. 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)

  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. 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)

  6. 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)

  7. Determination of the survival curve of the cell irradiated with low dose rate neutrons; Determinacao da curva de sobrevivencia de celulas irradiadas com neutrons a baixa taxa de dose

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Bruno M.; Freitas, Marcelo H.A. de; Campos, Tarcisio P.R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Silva, Luciana M.; Dias, Consuelo L.F. [Fundacao Ezequiel Dias, Belo Horizonte, MG (Brazil). Dept. de Pesquisa. Lab. de Bioquimica

    2000-07-01

    The effect of the radiation in tissue and cells are a theme of extreme importance and that is receiving large attention more and more now. This work purposes to evaluate the deleterious effects of the neutrons radiation at low dose rate in lineages of human cancerous cells through the analysis of survival curves. Deleterious effects due to radiation of low dose rate (3.8 mSv/hr) were observed in cells of the lineage HeLa S3. Previous studies, in lineage HN5 of tongue carcinoma, showed survive level to 0.2Sv of 80%, compatible to the value of 88,57% 0.4 Sv obtained for HeLa S3. In a close future, with the molecular biology characterization of a great number or possibly all cancer types (that will be accelerated largely with the conclusion of the human genome project), studies like this, can be much more specific, and could determine the efficiency of the neutrons or any other radiation type for each one of those types. Those data would have of great value for the medicine and they would help to plan the treatments better. (author)

  8. Experimental study of a PEM 15 W fuel cell; Influencia das temperaturas de operacao e umidificacao no desempenho de uma celula combustivel tipo 'PEM' de 15 W

    Energy Technology Data Exchange (ETDEWEB)

    Heusi, Daniel S.; Steidel, Paulo S.; Matelli, Jose A. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Lab. de Combustao e Engenharia de Sistemas Termicos (LabCET); Bazzo, Edson [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2004-07-01

    Experimental results are presented for a fuel cell type PEM of 15 W. The influence of the operating temperature, as well as the effect of the humidification temperature in the draining of the gases Hydrogen and oxygen, are considered for analysis. The tests were performed at operating temperature in the range of 30 to 70 deg C and humidification temperature form 30 to 85 deg C. For hydrogen flows fixed to be 200 ml/min and 300 ml/min, as well as for oxygen flow of 165 ml/min, the polarization curves were raised taking into account different combinations of operation and different combinations of humidification temperatures. (author)

  9. 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)

  10. 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)

  11. 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)

  12. 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)

  13. 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)

  14. 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)

  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. 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)

  17. 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)

  18. 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)

  19. 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)

  20. 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.

  1. 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)

  2. 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)

  3. 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)

  4. Effect of {sup 60} Co gamma radiation on trehalose level of Saccharomyces boulardii cells; Efeito da radiacao gama {sup 60} Co nos niveis de trealose de celulas de Saccharomyces boulardii

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Raquel Gouvea dos; Neves, Maria Jose [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil). Nucleo de Radiobiologia; Duarte, Rinaldo; Nicoli, Jacques R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Microbiologia

    1996-07-01

    The medicine Floratil used for diarrhea treatment is composed by lyophilized yeast cells of Saccharomyces boulardii. The action mechanism of this product is unknown. The efficacy of S. boulardii depends on its viability. The increase in the trehalose level in S. cerevisiae cells submitted to a previous sub-lethal level heat shock results in resistance to a lethal shock. The aim of this work was to study weather the cell trehalose level is involved also in the resistance of gamma irradiation. It was noted that the yeast cells surviving to gamma irradiation had more trehalose level than control cells. Apparently there is a positive correlation between of trehalose level and gamma irradiation resistance of S.boulardii cells. (author)

  5. 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)

  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. 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)

  8. 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.

  9. 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)

  10. Obtaining of ceria - samaria - gadolinia ceramics for application as solid oxide fuel cell (SOFC) electrolyte; Obtencao de ceramicas de ceria - samaria - gadolinia para aplicacao como eletrolito em celulas a combustivel de oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Arakaki, Alexander Rodrigo

    2010-07-01

    Cerium oxide (CeO{sub 2}) when doped with rare earth oxides has its ionic conductivity enhanced, enabling its use as electrolyte for Intermediate Temperature Solid Oxide Fuel Cell (IT-SOFC), which is operated in temperatures between 500 e 700 degree C. The most effective additives or dopants for ionic conductivity improvement are (samarium oxide - Sm{sub 2}O{sub 3}) and gadolinia (gadolinium oxide - Gd{sub 2}O{sub 3}), fixing the concentration between 10 and 20 molar%. In this work, Ce{sub 0,8}(SmGd){sub 0,2}O{sub 1,9} powders have been synthesized by hydroxide, carbonate and oxalate coprecipitation routes. The hydrothermal treatment has been studied for powders precipitated with ammonium hydroxide. A concentrate of rare earths containing 90wt% of CeO{sub 2} and other containing 51% of Sm{sub 2}O{sub 3} and 30% of Gd{sub 2}O{sub 3}, both prepared from monazite processing, were used as starting materials. These concentrates were used due the lower cost compared to pure commercial materials and the chemical similarity of others rare earth elements. Initially, the coprecipitation and calcination conditions were defined. The process efficiency was verified by ceramic sinterability evaluation. The results showed that powders calcined in the range of 450 and 800 degree C presented high specific surface area (90 - 150 m{sup 2}.g{sup -1}) and fluorite cubic structure, indicating the solid solution formation. It was observed, by scanning electron microscopy, that morphology of particles and agglomerates is a function of precipitant agent. The dilatometric analysis indicated the higher rate of shrinkage at temperatures around 1300-1350 degree C. High densification values (>95% TD) was obtained at temperatures above 1400 degree C. Synthesis by hydroxides coprecipitation followed by hydrothermal treatment demonstrated to be a promising route for crystallization of ceria nano powders at low temperatures (200 degree C). High values of specific surface area were reached with the employment of hydrothermal treatment (about 100 m{sup 2}.g{sup -1}). High density ceramics were obtained at lower temperatures (1400 degree C), compared to those employed for calcined powders. (author)

  11. Transitional cell carcinoma arising from a bladder diverticulum: computed tomography findings - case report; Carcinoma de celulas transicionais em um diverticulo de bexiga: achados na tomografia computadorizada - relato de caso

    Energy Technology Data Exchange (ETDEWEB)

    Almeida Junior, Jose Guiomar de; Santos, Maria Lucia de Oliveira; Vabo, Telmo Pimentel do; Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia]. E-mail: edmarchiori@zipmail.com.br; Torres Neto, Gilberto [Hospital Universitario Pedro Ernesto, Rio de Janeiro, RJ (Brazil). Dept. de Radiologia; Silva, Klezer Gaspar Carvalho da [Hospital de Clinicas de Niteroi, RJ (Brazil)

    2003-03-01

    We report the case of a patient with a transitional cell carcinoma arising from a bladder diverticulum that was diagnosed by computed tomography. Although there is a greater incidence of neoplasms in bladder diverticula, its occurrence is uncommon and the diagnosis is at times difficult. The role, the importance and limitations of computed tomography in the diagnosis of transitional cell carcinoma arising from a bladder diverticulum are discussed. (author)

  12. 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)

  13. 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)

  14. Comparative morphocytologic study of native and irradiated crotoxin on CBA/J mice tissues and cells; Estudo morfocitologico comparativo de crotoxina nativa e irradiada em tecidos e celulas de camundongos CBA/J

    Energy Technology Data Exchange (ETDEWEB)

    Cardi, Bruno A.

    1995-12-31

    Snake venoms submitted to gamma radiation are better immunogens, have less toxic activity and maintain immunogenic and antigenic properties, favoring its use in anti-sera production which is the main therapy in human accidents. Severe human accidents attributed to neurotoxicity, are caused by Crotalus durissus terrificus, which main toxin - crotoxin - acts on neuro muscular junctions, as detected by electrophysiological studies and could be detoxified by gamma radiation. In order to evaluate the biological effects of this irradiated protein, we analyzed, at morphological and immunohistochemical levels, organs and cells from CBA/J mice challenged with crude venom or purified crotoxin, in an acute intoxication model. Both toxins were submitted to 2 kGy irradiation with a Co-60 source, in water solution. (author). 140 refs., 10 figs., 1 tab.

  15. 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)

  16. 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)

  17. Microstructural development and characterization of lanthanum chromite-based ceramics to application in solid oxide fuel cells; Desenvolvimento microestrutural e caracterizacao de ceramicas a base de cromita de lantanio para aplicacao em celulas a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, R.N.; Furtado, J.G. de M.; Soares, C.M.; Serra, E.T. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)], e-mail: rnunes@cepel.br

    2006-07-01

    This work has for objective to investigate and to characterize the microstructural development of lanthanum chromite-based ceramics (LaCrO{sub 3}) doped with earth alkaline metals, correlating the microstructural parameters (mainly the densification level) and processing parameters with the electrothermal properties reached. Lanthanum chromite-based ceramic systems doped with earth-alkaline metals (Ca, Mg and Sr) had been produced from respective metallic nitrates by solid state reactions process. The phase compositions were evaluated by X-ray diffraction and the densification level by Archimedes method. The microstructural characterization was effected by scanning electron microscopy, energy dispersive X-ray spectroscopy and thermal analysis techniques. Electrical tests were used to evaluate the electrical conductivity of the studied ceramics. The obtained results corroborate the literature comments concerning the difficulty of lanthanum chromite-based ceramics with high densification level and evidence the great influence of the nature of the dopants on the sintering mechanism and the microstructural and electric characteristics of the produced ceramics. The best ones results, in terms of densification and electrical conductivity, had been gotten through multiple doping with calcium and strontium, and in sintering temperature conditions lower that the normally considered to pure or monodoped lanthanum chromite-based ceramics. (author)

  18. 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)

  19. 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.

  20. Polycrystalline materials by chemical-bath-deposition for their application in thin film solar cells; Materiales policristalino depositados por bano quimico alternativos al sulfuro de cadmio para su aplicacion en celulas solares de lamina delgada

    Energy Technology Data Exchange (ETDEWEB)

    Bayon Cabeza, M. R. [Ciemat. Madrid (Spain)

    2000-07-01

    In the last years, chemical-bath-deposition (CBD) has been proven to be an excellent method for preparing sulphide and selenide-based thin film semiconductors. due to their optoelectronic properties, some of those materials can be used in thin film solar cells either as absorbers or as buffer-window-layers. In this way, the chemical-bath-deposition seems to be the best method for preparing the cadmium sulphide-buffer layer which is present in the thin film solar cells based on chalcopyrite absorbers (CIS or CIGS) because the highest efficiencies (about 19%) have been achieved for devices using buffer layer. Nowadays there has been considerable interest in replacing this compound, said toxic, by other CBD-semiconductors with similar or even better properties than the cadmium sulphide and, if possible, less health hazardous and more environmental friendly. Among all the alternative materials that have been studied, both the indium and the zinc hydroxisulphide have produced the best performance devices leading to efficiencies higher than 14%. Despite the good results obtained using those materials, only a few studies have been found in relation to the chemical bath process, the growth mechanism and the structural, optoelectronic and morphological properties of the thin films. Therefore the aim of this work is to prepare CBD-indium, indium-zinc and indium-cadmium hydroxisulphide thin films in order to study dependence of the film properties on the deposition conditions and to prove the suitability of those films for being used as alternative buffer layers in thin film solar cells. (Author)

  1. 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)

  2. 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)

  3. Electric energy supply to isolated residences from the network through low power fuel cells; Fronecimento de energia eletrica a residencias isoladas da rede atraves de celulas a combustivel de baixa potencia

    Energy Technology Data Exchange (ETDEWEB)

    Serra, Eduardo Torres; Furtado, Jose Geraldo de Melo [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)], e-mail: etserra@cepel.br, e-mail: furtado@cepel.br

    2008-07-01

    This paper discusses the technical and socio economical aspects of the utilization of fuel cells for supplying electric power to isolated residences under an analysis on the global and brazilian energy scenarios, focusing the ascertaining of the high inequality of electric energy consumption among the various regions and countries in the world and the electric power access viability for the population lesser favoured. The paper performs an energetic analysis allowing an estimate of daily average consumption of electric energy of a low income family, and also discusses an attendance alternative of this demand by using small generation unities consisting of polymeric membranes fuel cells and reformers of primary fuel. Also, the paper analyses the possibilities of using various fuels for the hydrogen production to be used in fuel cell and estimates the cost of electric energy generated as function the main parameters which characterizes the enterprise.

  4. 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)

  5. 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)

  6. 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)

  7. 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)

  8. 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)

  9. 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)

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

    OpenAIRE

    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...

  11. 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)...

  12. "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…

  13. The RISC (Reduced Instruction Set Computer) Architecture and Computer Performance Evaluation.

    Science.gov (United States)

    1986-03-01

    8 )1; II;-21(82 ? 1JV , *~A 1*-e eo I Q .f ’ . - . - . .> - Approved for public release; distribution is unlimited. The RISC Architecture and Computer...1000 Lisboa Portugal 6. Manuel Pedrosa de Barros 4 Celula 5 Bloco 5 Lote D, 3 Direito 2795 Linda-a-Velha Portugal t~m " 96" ..... ...... |f

  14. 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

  15. [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.

  16. 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

  17. Paciente con deficiencia de adhesión leucocitaria tipo 1 y doble falla primaria de injerto

    Directory of Open Access Journals (Sweden)

    Alberto Olaya-Vargas

    2015-11-01

    Full Text Available Niño de 4 años de edad con diagnóstico de deficiencia de adhesión leucocitaria tipo 1, postrasplantado de células progenitoras hematopoyéticas en tres ocasiones, las dos primeras con falla primaria de injerto.

  18. Facilitating Subject Matter Expert (SME)-Built Knowledge Bases (KBS)

    Science.gov (United States)

    2004-12-01

    2.85 43 35 150 42.53% 111 102 52.11% 13 11.71% SRI SME Amoeba 2.29 30 30 364 62.28% 601 1292 31.75% 95 15.81% SRI SME Celula 1.68 25 25 554 27.77...Amoeba 0 0 2 2 5 86 SRI SME Celula 0 0 1 69 28 59 SRI SME Iflu 0 0 0 7 53 51 SRI KE sriPN 0 0 3 186 67 57 SRI KE sriAS 0 1 6 97 57 81 SRI SME Vaccinia 0...utilized only the NuSketch sketching tool which may have resulted in less complete answers. D iagnostic Q uestion D Q 1 W hich avenue of approach is explo

  19. Respostas ao défice hídrico em feijão (Phaseolus vulgaris) e caupi (Vigna unguiculata), induzidas por óxido nítrico

    OpenAIRE

    2007-01-01

    O oxido nitrico (NO) atualmente e reconhecido como um mediador intra e intercelular de diversas funcoes em celulas animais e vegetais. Enquanto alguns autores consideram-no como agente indutor de estresse, outros afirmam que o mesmo possua papel protetor agindo principalmente, na interrupcao de cadeias de radicais livres formadas sob estresse oxidativo. Os fatores mais limitantes ao crescimento vegetal sao os estresses ambientais sendo a falta de agua, o mais adverso. Os efe...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Condiciones físicas de formación de gabros ymigmatitas derivadas de rocas máficas en el centro de la Sierra de ValleFértil, San Juan Physical conditions for the formation ofgabbros and migmatites derived from mafic rocks in the center of Sierra deValle Fértil, 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.A sequence of plutonicmafic rocks inter-stratified with both mafic- and metasedimentary-derivedmigmatites is found along the San Juan valley in the center of the Sierra deValle Fértil. This natural example shows the transition from igneous tometamorphic petrologic processes which occurred during the crystallization ofmafic magmas and the subsequent partial melting of crystallized gabbroic rocks.This work studies the mineralogical changes associate to this petrologictransition. Thermobarometric estimates based on amphibole-plagioclase indicatethat the mafic magmas crystallized at around 1100ºC and 5 ± 0.5 kbar. Theconditions under which gabbroic rocks were partially melted are estimated usingtwo pyroxenes thermometry and amphibole-plagioclase thermobarometry. Similarphysical conditions in the range between 740 and 840ºC and 5 to 6.5 kbar arerecovery from mineral assemblages in the mesosomes and leucosomes of maficmigmatites. The main mineral compositional changes that accompanied the partialprocess of the gabbroic rocks are: 1 depletion of aluminium content and Mg#ratio in pyroxenes; 2 depletion of anorthite mole fraction of theplagioclases; and 3 depletion of the Mg# ratio in amphiboles. These mineralcompositional variations are consistent with those found by experimentallymelting mafic protoliths. Experimental results showed that the temperature forpromoting amphibole-dehydration melting in mafic protoliths is of around 850ºC,whereas the addition of an aqueous fluid would lower the melting temperature toaround 800ºC. Combining field relationships, textural features, mineralcompositional variations and thermo-barometric estimates with experimentalresults, we demonstrated that the transition from igneous mafic rocks to maficmigmatites was due to isobaric cooling. Moreover, repetitive intrusion of maficmagmas sustained the sequence at granulite-facies conditions, so avoiding rapidcooling. The natural case from the centre of the Sierra de Valle Fértil isinterpreted to expose an example of the plutonic-metamorphic core of theFamatinian magmatic arc, where the abnormally high metamorphic gradient provideevidence that large volume of mafic magmas reached and emplaced at paleodepthsof between 16 and 20 kilometres.

  5. 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.

    Directory of Open Access Journals (Sweden)

    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.

  6. 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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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)

  8. Consecuencias epistémicas y ontológicas para la definición de Gen y de Dogma Central de la Biología Molecular derivadas de las nuevas técnicas de secuenciación masiva en la Etapa Post-Genómica

    OpenAIRE

    Martínez Gómez, Pedro

    2015-01-01

    [ES] En estos momentos, en la llamada Etapa Post-Genómica, nos encontramos ante una nueva revolución biológica similar a la originada con el descubrimiento de la estructura del ADN y el desarrollo de la Genética Molecular. Esta nueva Etapa se caracteriza desde un punto de vista epistémico y metodológico por la incorporación de nuevos métodos de secuenciación tanto de ADN como de ARN y por el desarrollo de genomas que permiten referenciar de una forma precisa los resultados moleculares obtenid...

  9. Mérito de seis híbridos y líneas derivadas de girasol durante el desarrollo de la podredumbre blanca de capítulos Performance of six sunflower hybrids and derived inbred lines during white rot development in capitula

    Directory of Open Access Journals (Sweden)

    A. Giussani

    2008-06-01

    Full Text Available Se apreció el comportamiento de seis cultivares F1 y líneas F2:3 de girasol frente a la podredumbre blanca del capítulo. A los genotipos se los inoculó con Sclerotinia sclerotiorum y se les estimó: la incidencia, el período de incubación relativo, la severidad -en dos momentos- y el progreso de la enfermedad. Hubo diferencias entre genotipos para las cinco variables medidas. El cultivar MG 50 sobresalió por su comportamiento frente a todas las variables, excepto incidencia. Algunas líneas F2:3 tuvieron un nivel de resistencia similar a los mejores cultivares del ensayo. Dichas líneas continúan en el proceso de endocría y evaluación por su habilidad de producir una progenie de buena resistencia durante todas las fases del desarrollo de la podredumbre blanca de capítulos en girasol.Six sunflower F1 cultivars and F2:3 lines, obtained from self-fertilization of these cultivars, were evaluated for white rot performance. Genotypes were inoculated with Sclerotinia sclerotiorum and the disease incidence, relative incubation period, disease severity -at 40 days after inoculation and at maturity- and daily growth lesion rate were quantified. There were different white rot performances for all variables and the cultivar MG 50 showed a high level of resistance for all variables, except incidence. Some derived F2:3 lines showed a similar level of resistance to that of the best cultivars. These lines are still in the inbreeding process and then crossed to detect hybrids with the most adequate level of resistance to white rot in sunflower capitula.

  10. Mérito de seis híbridos y líneas derivadas de girasol durante el desarrollo de la podredumbre blanca de capítulos Performance of six sunflower hybrids and derived inbred lines during white rot development in capitula

    OpenAIRE

    Giussani, A.; F. Castaño; Rodríguez, R.

    2008-01-01

    Se apreció el comportamiento de seis cultivares F1 y líneas F2:3 de girasol frente a la podredumbre blanca del capítulo. A los genotipos se los inoculó con Sclerotinia sclerotiorum y se les estimó: la incidencia, el período de incubación relativo, la severidad -en dos momentos- y el progreso de la enfermedad. Hubo diferencias entre genotipos para las cinco variables medidas. El cultivar MG 50 sobresalió por su comportamiento frente a todas las variables, excepto incidencia. Algunas líneas F2:...

  11. 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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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)

  13. 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...

  14. Complicações decorrentes do posicionamento cirúrgico de clientes idosos submetidos à cirurgia de quadril Complicaciones derivadas de la colocación quirúrgica de clientes ancianos sometidos a cirugía de cadera Complications arising from surgical positioning in elderly clients submitted to hip surgery

    Directory of Open Access Journals (Sweden)

    Andréia Regina Lopes Grigoleto

    2011-09-01

    Full Text Available Este estudo de revisão sistemática da literatura, segundo as recomendações sugeridas pela Colaboração Cochrane, teve como objetivo buscar nas publicações das bases de dados consultadas as evidências disponíveis sobre complicações decorrentes do posicionamento cirúrgico em idosos submetidos à cirurgia de quadril. Nesta revisão, os estudos identificados e discutidos apresentaram aspectos importantes no desenvolvimento de uma prática efetiva, possibilitando maior compreensão da necessidade de elaboração de pesquisas melhores delineadas que proporcionem validade interna de estudos futuros, para que seus resultados possam ser utilizados na prática clínica.El estudio de revisión sistemática de la literatura, siguiendo las recomendaciones de la Colaboración Cochrane, tuvo como objetivo buscar en las publicaciones que figuran en las bases de datos consultadas, las evidencias disponibles para las complicaciones causadas por la colocación quirúrgica en ancianos sometidos a cirugía de cadera. Los estudios identificados y discutidos en esta revisión presentan aspectos importantes en el desarrollo de una práctica eficaz, permitiendo una mayor comprensión de la necesidad de desarrollar estudios mejores delineados que proporcionan validez interna de los futuros estudios, a fin de que sus resultados puedan ser utilizados en la práctica clínica.The study of this systematic literature review according to the recommendations suggested by Cochrane's Collaboration, had the aim to search in the publications listed in the databases consulted, the available evidences about complications arising from surgical positioning in elderly clients submitted to hip surgery. The studies identified and discussed in this review presented important aspects in the development of an effective practice, enabling greater understanding of the need to elaborate better delineated researches that provide internal validity for future studies, enabling the use of their results in clinical practice.

  15. 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.

  16. 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

    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...

  17. [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.

  18. [Pathogenesis of spinal cord injuries and mechanisms of repair induced by olfactory ensheathing cells].

    Science.gov (United States)

    Botero, Lucía; Gomez, Rosa Margarita; Chaparro, Orlando

    2013-05-16

    Introduccion. La lesion medular es un evento catastrofico, cuyas consecuencias persisten durante toda la vida del paciente. La investigacion en tratamiento se ha basado principalmente en el desarrollo de terapias que reduzcan la discapacidad, pero desde los anos noventa hay un avance significativo y se han probado varios trasplantes celulares en modelos animales de lesion medular, celulas de Schwann, astrocitos y celulas de la glia envolvente olfatoria (CGEO). Objetivo. Hacer un recuento detallado de la patogenia de la lesion medular primaria y secundaria y de los mecanismos por los cuales las CGEO inducirian sus posibles efectos regenerativos descritos en la bibliografia. Desarrollo. Despues del traumatismo, la lesion se desarrolla en dos fases, la primaria se caracteriza por las lesiones de compresion y la secundaria se produce por una serie de factores que se dan en paralelo y que incluyen factores vasculares, celulares, moleculares y formacion de cicatriz glial. La mayoria de los modelos de lesion medular y trasplante con CGEO han comunicado recuperacion funcional, remielinizacion y regeneracion axonal. Estas celulas ejercen su accion de manera indirecta a traves de la produccion de factores de crecimiento y de manera directa induciendo regeneracion neuronal, axonal y remielinizacion. Conclusiones. Las CGEO son una opcion terapeutica en pacientes con lesion medular debido a que inducen de modo directo o indirecto regeneracion neuronal, axonal, remielinizacion de axones, disminucion de cicatriz glial y otros efectos que conducen a la recuperacion funcional.

  19. Un estudio del cambio y la variación a través de su representación gráfica

    OpenAIRE

    Amaya, Tulio

    2006-01-01

    En el presente trabajo se aborda el estudio de la variación de una función cualquiera cuando se tiene sólo su representación gráfica y no se conoce su representación algebraica, así como la relación de la función con su primera y su segunda derivada y la relación entre tales derivadas, esto es, la información que puede proporcionar cada derivada acerca de la función y la información que aporta cada derivada con respecto a la otra.

  20. 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)

  1. 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)

  2. 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)

  3. Application of a method for the determination of yeast cell density to studies on the sedimentation of Saccharomyces cerevisiae in alcoholic fermentation broths; Aplicacao de metodo para a determinacao da densidade de celulas de leveduras a estudos sobre sedimentacao de Aaccharomyces cerecisiae em mostos de fermentacao alcoolica

    Energy Technology Data Exchange (ETDEWEB)

    Maia, Amazile B.R.A. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Escola de Engenharia. Dept. de Engenharia Quimica; Nelson, David Lee [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Farmacia. Dept. de Alimentos

    1993-09-01

    A technique that permitted the determination of the Saccharomyces cerevisiae cell density was developed. The average results (1,04 g/ml) attributed to the cells under the conditions of the effected tests, was applied to a previously developed mathematical model for predicting the clarification velocity of alcoholic fermentation broths in a sedimenter prototype designed for accelerating the sedimentation of cells. (author) 19 refs., 1 fig., 4 tabs.

  4. 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)

  5. 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)

  6. 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)

  7. 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)

  8. 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)

  9. 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.

  10. 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)

  11. {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)

  12. 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)

  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. 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)

  15. 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)

  16. 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)

  17. 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)

  18. 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)

  19. 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)

  20. 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)

  1. 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)

  2. 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)

  3. 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)

  4. 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)

  5. Labeling of vasoactive intestinal peptide (VIP) and VIP 10-28 fragment with radioiodine by direct method. Comparative study of the kinetics biodistribution and affinity for neuroendocrine tumor cells; Marcacao do peptideo intestinal vasoativo (VIP) e do fragmento VIP10-28 com radioiodo por metodo direto. Estudo comparativo da cinetica de biodistribuicao e da afinidade por celulas de tumor neuroendocrino

    Energy Technology Data Exchange (ETDEWEB)

    Colturato, Maria Tereza

    2005-07-01

    In the progress of the Nuclear Medicine, many protein based radiopharmaceuticals have been developed in the last years using antibodies and, more recently, biologically active natural peptides or similar synthetic peptides. In the search for agents with specificity for the target tissue in tumors detection, it was verified that small sequences of amino acids may interact with selective sites, with homogenous distribution, fast accumulation in tissues and fast blood clearance when compared to the antibodies. Among the peptides used in the diagnosis of tumors, Vasoactive Intestinal Peptide (VIP) has been studied. VIP labeled with iodine-123 is applied in the images of intestinal adenocarcinoma and endocrine tumors. The molecule of VIP contains two tyrosine residues, in the positions 10 and 22 that are, theoretically, equally susceptible to radioiodination for direct method. The objective of this work was to produce VIP labeled with radioiodine (iodine-123), in order to introduce to the brazilian medical class this radiopharmaceutical of interest for the diagnosis and recurrence of tumors that express specific receptors. In an unpublished way, the work studied the labeling and the kinetic distribution of the VIP fragment (VIP 10-28) and verified its potential as radiopharmaceutical applied in the identification of tumors that express VIP receptors. After the choice of the appropriated technique for labeling VIP and VIP 10-28 with radioiodine, using Ceremonial T as oxidant agent and sodium metabisulfite as reducing agent, the quality control procedures were accomplished (electrophoresis and high performance liquid chromatography, HPLC) for radiochemical purity determination as well as the separation of the radiochemical species obtained. Labeling and quality control procedures applied were efficient and accurate. [{sup 131}I]VIP and [{sup 131}l]VIP 10-28 were obtained with high radiochemical purity (> 95%). The purification studies to remove free radioiodine in the labeling mixture (simple purification) and to produce the radiopharmaceutical with high specific activity (complex purification and HPLC), were both efficient in the separation of the species in the reaction mixtures, as demonstrated by quality control procedures. Biological distribution studies were accomplished by venous administration of the radiopharmaceuticals in laboratory animals: biodistribution study of [{sup 131}I]VIP and [{sup 131}I]VIP 10-28 in normal Swiss mice, [{sup 131}I]VIP not purified and purified in Swiss mice with tumor and [{sup 131}I]VIP and [{sup 131}I]VIP 10-28 in Nude mice with tumor, scintigraphic images of [{sup 131/123}I]VIP and [{sup 123}I]VIP 10-28 in Swiss and Nude mice and Wistar rats with tumor. In vitro studies were accomplished to determine the percentage of [{sup 131}I]VIP and [{sup 131}I]VIP 10-28 bound to plasmatic proteins, stability study of [{sup 131}I]VIP and [{sup 131}I]VIP 10-28 in human plasma and the affinity and internalization of [{sup 131}I]VIP and [{sup 131}I]VIP 10-28 by tumour adenocarcinoma cells of human rectal colon (HT-29). All biological distribution studies demonstrated that both [{sup 131/123}I]VIP and [{sup 131/123}I]VIP 10-28 showed fast blood clearance, low renal and liver uptake, relative uptake in thyroid, showing in vivo dehalogenation and good uptake in tumour. Comparative biological distribution of the radiopharmaceuticals showed high uptake in the stomach for both peptides. The blood clearance of the fragment was slower, and influences the visualization of the tumour mass. The radiopharmaceuticals, [{sup 123}I]VIP and [{sup 123}I]VIP 10-28, were obtained with high radiochemical purity, but with low radiochemical yield when comparing with labeling procedures using iodine-131. Quality control assays of [{sup 123}I]Na indicated that the presence of radiochemical and radionuclide impurities influenced on labeling results. (author)

  6. 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)

  7. 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)

  8. 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)

  9. 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)

  10. 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)

  11. 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)

  12. 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)

  13. Seed production lines of maize: population density and interaction.

    OpenAIRE

    Juan Virgen-Vargas; Rosalba Zepeda-Bautista; Miguel Ángel Ávila-Perches; Alejandro Espinosa-Calderón; José Luis Arellano-Vázquez; Alfredo Josúe Gómez-Vázquez

    2014-01-01

    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...

  14. 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.…

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. Study on In-Theater Maintenance Support for POAF F-16

    Science.gov (United States)

    1991-09-01

    0.9 0.4 0.9 1.1 30 0.4 0.4 0.9 1.2 62 z A CO) 00 b, w - Q w V,> CI + Q ) CM 4bS *b 63q AVERAGE DAILY SORTIES FLOWN SCENARIO DAY M N 0 P 1 10.3 10.2 10.1...1990. Permanent Address: Celula C - Lote 58A - 6 C Quinta Grande Alfragide 2700 Amadora, Portugal 79 I Form ApprOvedJ REPORT DOCUMENTATION PAGE om Novd4

  1. Isolating of Target Genes for NKX3.1 in Prostate Carcinogenesis

    Science.gov (United States)

    2005-03-01

    stainin on e te o tesr prostate hist log .(Band - . (C a .. ( 2 (M -P) Ki6 s shows . celula pr lf rto in c( ssi Fg1.prosthate cane r progresin is enh...from PIN or cancer lesions compoundp27kiPz heterozygotes (Figs. 1 Q -Tand 7). Therefore, the of these mice followed by real-time RT-PCR. We found that...9. Wang, S., Gao, J., Lei, Q ., Rozengurt, N., Pritchard, C., Jiao, J., Thomas, G. V., Li, G., 24. Kim, M. J., Bhatia-Gaur, R., Banach-Petrosky, W. A

  2. European Science Notes Information Bulletin Reports on Current European/Middle Eastern Science,

    Science.gov (United States)

    1989-07-01

    are traveling in Europe may also be invited to submit reports. ) Q j) 5 ’ W9, A, AP AR!T C59 4BAS7ACI 21 ABSTRACT SECURITY CLASSIFICATION E QAS 3 N V...ionic strengths and are inter-tem eguatig vaiou celula fuctins.preted as equilibrium shifts between the two main con-tern regulating various cellular...matrices covered the range of purifcation steps for recombinant Q Sepharose HP TM and Supcrdcx 75 pg were used. proteins from the primary separation to

  3. Estudo de 43 pacientes com atrofia muscular espinhal e seu diagnóstico molecular

    OpenAIRE

    Carvalho, Laís Regina Rocha de; Scola, Rosana Herminia

    2003-01-01

    Apendice e Anexos Orientadora: Rosana Herminia Scola Dissertaçao(mestrado)- Universidade Federal do Paraná. Setor de Ciencias da Saúde. Departamento de Clínica Médica. Curso de Pós-graduaçao em Medicina Interna Inclui bibliografia Resumo: A atrofia muscular espinhal e uma doenca degenerativa das celulas do como anterior da medula, com quatro tipos descritos (I, II, IIIa/b, IV). Somente os tipos I, II, Illa e Illb apresentam comprometimento do cromossomo 5ql3, em que dois genes sao...

  4. 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)

  5. 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.

  6. 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)

  7. 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)

  8. 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)

  9. Metodos de derivación numérica

    OpenAIRE

    2013-01-01

    [ES] Se estudia como en determinadas ocasiones se necesita proceder al cálculo del valor de alguna derivada de tales funciones en algún punto concreto, que pertenece o no al soporte. Es obvio que en este tipo de situaciones no se puede utilizar la definición matemática de la derivada, por lo cual surge la necesidad de diseñar algún procedimiento numérico que nos permita aproximar el valor de las derivadas de tal función en algún punto a partir del conocimiento de los valores de la función en ...

  10. 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.

  11. The Use of Line Excitation Mapping to Investigate Planetary Nebula Morphologies

    Directory of Open Access Journals (Sweden)

    J. P. Phillips

    2004-01-01

    Full Text Available Está ahora bien establecido que las nebulosas planetarias circulares, elípticas y bipolares poseen diferentes características físicas y espaciales. No sólo son distintas sus estructuras, sino que también parecen tener distintas temperaturas de Zanstra, abundancias, velocidades de expansión, temperaturas de brillo y alturas de escala sobre el plano Galáctico. Reportamos aquí una manera más sensible para ilustrar las diferencias entre estos flujos. Señalamos que las nebulosas poseen muy distintos cocientes de intensidad de sus líneas de emisión y que esto probablemente sea consecuencia de las distintas masas de sus estrellas progenitoras. Asimismo, recalcamos el potencial del mapeo de los cocientes de intensidad de líneas para analizar otras clases morfológicas, asì como para establecer la singularidad de su población y las masas relativas de sus progenitoras. Asì, encontramos que las fuentes con chorros poseen a menudo líneas de emisión de baja intensidad con relación al hidrógeno, lo cual sugiere que provienen de estrellas de baja masa. Esta conclusión está sustentada en una variedad de evidencias observacionales independientes. También mostramos que las fuentes irregulares aparentemente representan una clase distinta de flujos. Es probable que las masas medias de sus progenitoras sean mayores que las de las nebulosas planetarias elípticas, pero menores que las de los flujos bipolares.

  12. 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.

  13. [Hematopoietic stem cells transplant in patients with common variable immunodeficiency. Is a therapeutic option?

    Science.gov (United States)

    Cambray-Gutiérrez, Julio César; Herrera-Sánchez, Diana Andrea; López-Pérez, Patricia; Chávez-García, Aurora; Yamazaki-Nakashimada, Marco Antonio

    2017-01-01

    Antecedentes: Los pacientes con inmunodeficiencia común variable presentan mayor incidencia de infecciones sinopulmonares y gastrointestinales, así como de enfermedades linfoproliferativas y autoinmunes. El tratamiento de elección es el reemplazo con gammaglobulina humana. El trasplante de células progenitoras hematopoyéticas es una modalidad terapéutica no convencional. Caso clínico: Mujer de 26 años de edad sin antecedentes heredofamiliares de inmunodeficiencias primarias ni consanguinidad, con procesos repetidos de otitis, sinusitis, gastroenteritis y bronquitis desde la infancia. En la adolescencia fue diagnosticada con inmunodeficiencia común variable; se le prescribió gammaglobulina intravenosa, antimicrobianos de amplio espectro y macrólidos. A los 22 años se le realizó trasplante de células progenitoras hematopoyéticas por continuar con infecciones severas. A los 4 meses del trasplante se le diagnosticó hipotiroidismo e insuficiencia ovárica. Durante los siguientes 3 años no presentó infecciones, pero a los 25 años manifestó púrpura trombocitopénica inmune, que persistía al momento de este informe con enfermedad de Raynaud e infecciones reincidentes de vías respiratorias altas. Es tratada con gammaglobulina intravenosa y profilaxis con claritromicina, sin esteroides ni danazol. Conclusiones: Dada la alta tasa de morbimortalidad asociada y falla en la reconstitución inmunológica, el trasplante de células progenitoras hematopoyéticas deberá ser cuidadosamente evaluado en pacientes con infecciones sin respuesta al tratamiento o con enfermedades linfoproliferativas.

  14. 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...

  15. NADPH oxidasas como diana terapéutica en leucemia meloide crónica (CML)

    OpenAIRE

    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...

  16. Polimorfismos en los genes del sistema inmune innato (mannose-binding lectin, toll-like) y riesgo de infección en pacientes con trasplante autólogo de progenitores hematopoyéticos

    OpenAIRE

    Moretó Quintana, Ana

    2014-01-01

    RESUMEN: Introducción: El trasplante autólogo de progenitores hematopoyéticos (TAPH) consiste en la transferencia de células progenitoras recogidas previamente a un paciente, tras la administración de quimioterapia a altas dosis. Es una terapia curativa para una variedad de estados de fallo medular, neoplasias hematológicas, deficiencias inmunes etc. Debido al acondicionamiento mieloablativo que se emplea, se produce una inmunodepresión que se puede dividir en 3 fases: periodo de neutropenia ...

  17. Puntos de Encuentro Familiar

    OpenAIRE

    Calzada Guadilla, Nerea

    2013-01-01

    El Proyecto presentado hace referencia a un recurso público destinado a familias en proceso de separación o divorcio con los hijos menores: los Puntos de Encuentro Familiar en la Comunidad de Castilla y León. Los Puntos de Encuentro Familiar (PEF), están destinados a favorecer y facilitar el cumplimiento del régimen de visitas con el progenitor/a no custodio/a con los hijos menores. Dentro de estos recursos tiene cabida la intervención socio-educativa de los educadores sociales. Los e...

  18. Leucemia linfóide aguda na infância: A Importância do diagnóstico citogenético convencional como fator prognóstico

    OpenAIRE

    Minasi, Lysa Bernardes

    2009-01-01

    A leucemia linfóide aguda é considerada o resultado de anormalidades ocorrendo em uma célula progenitora do sistema linfo-hematopoético. As anormalidades modificam o programa de diferenciação celular, determinando uma vantagem proliferativa do clone leucêmico sobre as demais células do tecido hematopoético. A sobrevida livre de leucemia por mais de cinco anos, que é considerada como critério de cura para a doença, nos últimos anos, tem sido de aproximadamente 80%. Na população ...

  19. Policitemia vera - caracterização clinica e molecular e novas abordagens terapêuticas

    OpenAIRE

    Amaral, Cecília Beatriz Alves

    2009-01-01

    Dissertação de mestrado integrado em Medicina (Hematologia), apresentado á Faculdade de Medicina da Universidade de Coimbra. A Policitemia Vera (PV) é uma doença clonal de etiologia desconhecida, na maior parte dos casos, que envolve a célula estaminal progenitora hematopoiética multipotencial. É uma neoplasia mieloproliferativa crónica (NMP) que se caracteriza pela expansão das três linhas celulares hematopoiéticas: eritróide, granulocítica e megacariocítica, com predomínio da primeira, d...

  20. Recolección de células madre en sangre periférica mediante aféresis de grandes volúmenes

    OpenAIRE

    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...

  1. Aspectos bioéticos en el uso de bancos de células madre de cordón umbilical

    OpenAIRE

    Tejada Zevallos, Edgar Humberto

    2013-01-01

    Existen diferentes tipos de células madre en la sangre del cordón umbilical: células hematopoyéticas, células mesenquimales y células progenitoras del tejido endotelial. Pero hay un cuestionamiento particular el cual es objeto de discusión y consiste en qué tipo de banco de células madre debe ser promovido; los bancos públicos o los bancos privados. La discusión es necesaria debido a que se presentan posiciones que sostienen criterios que se oponen uno a otro. La primera controversia bioética...

  2. Advances in the use of stem cells in orthopedics

    OpenAIRE

    2011-01-01

    As células primordiais, ou células-tronco, são células indiferenciadas multipotentes com a capacidade de originar qualquer tipo de tecido no organismo. Podem ter origem no blastocisto, sendo classificadas como embriônicas, ou em tecidos desenvolvidos de fetos, recém-nascidos ou adultos, conhecidas como célulastronco somáticas. Como um dos principais locais de isolamento da célula primordial está a medula óssea, tendo duas linhagens: células progenitoras hematopoéticas e mesenquimais. Existem ...

  3. 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.

  4. Estudos sobre tuberculose

    Directory of Open Access Journals (Sweden)

    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.

  5. 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

    Directory of Open Access Journals (Sweden)

    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

  6. THE SAN PEDRO MÁRTIR PLANETARY NEBULA KINEMATIC CATALOGUE: EXTRAGALACTIC PLANETARY NEBULAE

    Directory of Open Access Journals (Sweden)

    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.

  7. SEVERAL WAYS TO BRIGHTNESS

    Directory of Open Access Journals (Sweden)

    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.

  8. 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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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)

  10. Tyrosine, Tryptophan and Performance

    Science.gov (United States)

    1992-01-22

    a- e PCUMENTATION PAGE F .A q . 4_ Waq _III I u f I I 0’ND-A246 954 0 - Sdofr oATI I . nlpsti r0vn Amo OATU cOVsUD 22 Januarv 1992 ]Annual Jan. 9 -Dec...Indiana, May 15-17, 1991. Deng, M.H., Lynch H.J., Wurtman, R.J. and Lopez G.-Coviella, I. La diferenciacion de celulas de retinoblastoma...100 mg/kg) onou strreata4 25 THE EFFECT OF Ro 40-7592 ON SYSTOLIC BLOOD PRESSURE 220- 0-0 SAL + NET *- COMTI + NE LL 200 (fl T/ 0 V) 180 0 ± W M Q

  11. Aislamiento, purificación y caracterización de la nucleósido difosfato quinasa del hongo patógeno Candida albicans : Comparación con otras especies

    OpenAIRE

    Biondi, Ricardo M

    1996-01-01

    La enzima nucleósido difosfato quinasa (NDP quinasa) es ubicua y cataliza la síntesis de NTPs a partir de sus correspondientes NDPs y un NTP dador (fisiológicamente el ATP). La reacción sigue una cinética de ping-pong con la formación del intermediario de alta energía (P)NDP quinasa. Aparte de su rol fundamental en la síntesis de NTPs, se ha relacionado a esta enzima con a) la activación de proteínas G en la transducción de señales, b) la diferenciación de Drosophila y distintas líneas celula...

  12. Gestão organizacional sob a lógica da competência: aplicação na pequena empresa.

    Directory of Open Access Journals (Sweden)

    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.

  13. Cell death induced by tamoxifen in human blood lymphocytes cultivated in vitro = Morte celular induzida pelo tamoxifeno em linfócitos humanos cultivados in vitro

    Directory of Open Access Journals (Sweden)

    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

  14. Uso de las gráficas en una situación de modelación de movimiento. Variaciones de primer y segundo órdenes

    OpenAIRE

    Flores,Claudia; Suárez, Liliana

    2009-01-01

    Este trabajo reporta los resultados de una investigación que tiene como propósito analizar la construcción de ideas en el conocimiento matemático que logran algunos estudiantes de bachillerato del Instituto Politécnico Nacional al realizar la graficación de una situación real de movimiento. El marco teórico es la socioepistemología. En particular, se retoma la hipótesis de que la noción de derivada no puede construirse sino después de haberse construido la idea de derivada sucesiva. Se muestr...

  15. ANÁLISIS DE SENSIBLIDAD GLOBAL DE UN MODELO DE LECHUGAS (Lactuca sativa L.) CULTIVADAS EN INVERNADERO

    OpenAIRE

    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...

  16. Spectral Reflectance Analysis of the Caribbean Sea

    OpenAIRE

    Raúl Aguirre Gómez

    2014-01-01

    En este trabajo se analizaron curvas de reflectancia espectral mediante el método de derivada. Los espectros de derivada de la reflectancia revelaron picos ocultos tanto en curvas de reflectancia y absorción del agua del Mar Caribe y de elementos contenidos en ella. Las curvas de reflectancia mostraron un predominio del color azul (400-500 nm), el cual es característico de aguas oligotróficas del Caribe, los picos de absorción están influenciados por las propiedades ópticas de la clorofila a ...

  17. ALGUNAS REFLEXIONES EN TORNO A LA NECESIDAD DE UNA TEORÍA DEL DERECHO Y DE LOS CASOS DIFÍCILES ACORDE AL CONTEXTO DEL ESTADO CONSTITUCIONAL COLOMBIANO

    OpenAIRE

    Sergio Iván Estrada Vélez; Julián García Ramírez

    2009-01-01

    El fortalecimiento de una cultura jurídica y filosófica debe estar atado al reconocimiento de las transformaciones políticas derivadas de la incorporación del modelo de Estado social y constitucional de derecho. Este escrito se propone, a través de una aproximación a dos temas importantes: la teoría general del derecho y la teoría de los casos difíciles, advertir las principales implicaciones teóricas y metodológicas derivadas de dicho modelo y denunciar algunos obstáculos que han impedido...

  18. A equação de Schrödinger fracionária com potenciais delta

    OpenAIRE

    2016-01-01

    Neste trabalho, estudaremos o efeito de derivadas fracionárias espaciais na equação de Schrödinger unidimensional independente do tempo, para o caso particular de potenciais do tipo Delta de Dirac. Inicialmente, apresentamos alguns conceitos importantes relacionados ao Cálculo Fracionário e discutimos a formulação da mecânica quântica, obtendo a Equação de Schrödinger, com base em integrais de caminho de Feynman. Em seguida, introduzimos a Equação de Schrödinger Fracionária com derivada fraci...

  19. Pn-carbon yields and the chemical evolution of the galaxy

    Directory of Open Access Journals (Sweden)

    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.

  20. Fungi associated with Acromyrmex and basal Attini ants from Argentina and Brasil

    OpenAIRE

    Masiulionis, Virginia Elena [UNESP

    2013-01-01

    As formigas cultivadoras de fungo (tribo Attini) são insetos eusociais, os quais formam colônias de centenas até milhões de indivíduos, sendo o fungo a principal fonte de alimentação das larvas e a rainha. Segundo sua fungicultura, elas são divididas em grupos, onde encontram-se as denominadas agricultura de “Lower-Attini” (agricultura das formigas basais) e aquelas com agricultura derivada ou “Higher-Attini”. Dentro da agricultura derivada, estão as formigas conhecidas como “cortadeiras”, qu...

  1. Los limites del Presidencialismo en México.

    OpenAIRE

    Calzada Herrera, Alejandra.

    2015-01-01

    Se presenta un panorama general del presidencialismo mexicano hasta el día de hoy, en el aspecto de organización, así como las más importantes facultades que el presidente posee, derivadas de la constitución y las leyes derivadas de la misma, que buscan un equilibrio entre los poderes de la Unión Ejecutivo, Legislativo y Judicial. Sus objetivos analizar los antecedentes históricos del presidencialismo en México; así como facultades, características y límites que tiene el poder Ejecutivo en...

  2. Diferenciación automática de fuerzas en la integración implícita de sistemas multicuerpo

    OpenAIRE

    Callejo Goena, Alfonso; García de Jalón de la Fuente, Francisco Javier; Hidalgo, Andrés Francisco

    2010-01-01

    La diferenciación automática es una herramienta informático-matemática muy potente para calcular cualquier tipo de derivadas de funciones. Entre sus ventajas respecto a otras formas de calcular derivadas están su precisión, su eficiencia y su sencillez de implementación. Este artículo trata sobre la implementación de esta técnica en un algoritmo de simulación dinámica de sistemas multicuerpo. Concretamente, se aplica a un integrador implícito que resuelve las ecuaciones diferenciales del ...

  3. Avanços tecnológicos em hematologia laboratorial

    OpenAIRE

    Naoum,Paulo C.

    2001-01-01

    O recente avanço científico e tecnológico direcionado à identificação imuno-hematológica de produtos celulares (ex.: citocinas, interleucinas, interferons, entre outros) sintetizados por determinadas células sanguíneas, bem como na identificação de antígenos de membrana de leucócitos e células progenitoras hematopoiéticas, promoveram excepcional desenvolvimento no diagnóstico laboratorial de diversas doenças hematológicas. Somam-se a esse fato as aplicações das técnicas de biologia molecular ...

  4. CLASSIFYING THE STELLAR ENVIRONMENT AROUND V838 MONOCEROTIS

    Directory of Open Access Journals (Sweden)

    V. A. Rosero-Rueda

    2008-01-01

    Full Text Available El comportamiento de V838 Mon y la naturaleza de la estrella progenitora no están bien entendidos aún. Recientemente han sido encontradas estrellas de tipo B en la vecindad de V838 Mon y se piensa que ésta podrá ser parte de un cúmulo abierto de población estelar joven. Debido a que el c umulo se encuentra en un brazo espiral de la Galaxia, resulta complicada la identi cación de más miembros del mismo; por lo que se hacen necesarios diversos estudios fotométricos y espectroscópicos. Presentamos los resultados preliminares de nuestro análisis fotométrico con imágenes obtenidas por la Cámara Avanzada de Rastreo (ACS del Telescopio espacial Hubble (HST.

  5. La terapia celular en la cardiopatía isquémica

    OpenAIRE

    Escobedo-Uribe,Carlos David; Monsiváis-Urenda, Adriana Elizabeth; López-Quijano, Juan Manuel; Carrillo-Calvillo,Jorge; Leiva-Pons,José Luis; Peña-Duque, Marco Antonio

    2012-01-01

    La cardiopatía isquémica es la principal causa de muerte e insuficiencia cardiaca a nivel mundial. Esto hace de vital importancia el desarrollo de nuevas modalidades terapéuticas, que disminuyan la mortalidad y complicaciones a largo plazo en estos pacientes. Una de las principales líneas de investigación a nivel mundial es la regeneración miocárdica a partir de células progenitoras, con el fin de mejorar la función sistólica y diastólica de los pacientes con cardiopatía isquémica, además de ...

  6. 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...

  7. "Células mononucleares de sangue de cordão umbilical e de sangue periférico estimulado com fator de crescimento granulocítico (G-CSF) : análise da proliferação e de apoptose in vitro"

    OpenAIRE

    Andreza Alice Feitosa Ribeiro

    2003-01-01

    Células mononucleares de sangue de cordão umbilical (SCU) e sangue periférico mobilizado (SPM) com G-CSF, foram cultivadas in vitro com citocinas, na presença ou não de estroma de medula óssea. Os objetivos foram avaliar a capacidade proliferativa de células progenitoras, a ocorrência de apoptose e expressão de integrina. Nas culturas sem estroma, a celularidade aumentou 5 vezes (SCU) e não se alterou nas de SPM. O total de células CD34+ caiu em ambas culturas. Com estroma, o total de células...

  8. Avaliação do perfil de expressão gênica de células CD34+ e células CD CD133+ isoladas de medula óssea e de sangue de cordão umbilical

    OpenAIRE

    Oliveira, Lucila Habib Bourguignon [UNESP

    2008-01-01

    A maior expressão de alvos transcricionais e componentes da via NFkB é uma característica distintiva das células-tronco hematopoéticas (CTH) CD34+ de sangue de cordão umbilical (SCU) comparadas às CTH CD34+ de medula óssea (MO) e pode estar relacionada com o estado mais primitivo das CTH dos neonatos. No entanto, as células CD34+ são um grupo heterogêneo de célulastronco (CT) e progenitoras em diferentes estágios de maturação e diferenças na composição celular entre MO e SCU poderiam contribu...

  9. Preservation of cuspy profiles in disk galaxy mergers

    Directory of Open Access Journals (Sweden)

    H. Aceves

    2006-01-01

    Full Text Available Se efectuaron tres simulaciones auto-consistentes de N-cuerpos de fusiones entre galaxias, con un perfil pronunciado de materia oscura, para estudiar si la pendiente interna del perfil de densidad oscura se preserva en los remanentes. En estas simulaciones los progenitores incluyen un disco estelar y un espín intrínsico en el halo a diferencia de estudios similares. La razón de masas de las galaxias progenitoras es de alrededor de 1:1, 1:3 y 1:10. Encontramos que el perfil de densidad inicial pronunciado de los halos oscuros se preserva en los remanentes para los casos considerados aquí.

  10. Infrared imaging and optical imaging and spectroscopy of (mostly type I Planetary Nebulae. I.

    Directory of Open Access Journals (Sweden)

    J. Bohigas

    2001-01-01

    Full Text Available Se presenta información espectroscópica, imágenes en las principales líneas ópticas de emisión e imágenes infrarojas para descubrir la presencia de hidrógeno molecular, de 14 nebulosas planetarias (NPs. Nueve de ellas satisfacen los dos criterios que definen a las NPs de tipo I (ricas en helio con un alto cociente de N/O. Todas éstas son bipolares y, excepto Sh 2-71, muestran H2 chocado. La composición química de JnEr 1 implica que fue producida por una progenitora masiva y puede ser tentativamente clasificada como de tipo I. A 26 es una NP elíptica rica en helio, con un bajo cociente de N/O y probablemente sin H2. Se encontró hidrógeno molecular chocado en K 3-92, una NP elíptica de tipo IIb, lo que significa que este objeto es probablemente joven. La composición química de K 3-72, K 4-55, M 1-75 y Sh 2-71 indica que se produjeron episodios de tercer dragado en su estrella progenitora. Las temperaturas y propiedades espectrales de BV 5-1, K 4-55, M 1-41, M 1-75 y Sh 2-71 sugieren la existencia de ondas de choque en su componente ionizada.

  11. Substellar secondaries in zero-age cataclysmic variables

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    M. Politano

    2004-01-01

    Full Text Available Se investiga la formaci on actual de variables catacl smicas (CVs con secundarias de enanas marrones (BD utilizando la t ecnica de s ntesis de poblaci on. En el c odigo de s ntesis de poblaci on se incorporaron resultados de los ultimos modelos detallados para las BDs. Encontramos que CVs de edad cero (ZACVs con secundarias BDs poseen per odos orbitales comprendidos en el intervalo 46 min { 2.5 horas, formando el 18% del total de la poblaci on actual de ZACVs. Por lo tanto encontramos que el 15% de la poblaci on actual de ZACVs deber a tener per odos orbitales m as cortos que el per odo orbital m nimo observado para CVs. Investigamos tambi en la dependencia de la tasa actual de formaci on de CVs con secundarias BD con el valor asumido del par ametro de e ciencia de la envolvente com un CE, asumiendo tres distribuciones de cociente de masas diferentes para binarias ZAMS. Encontramos que el proceso de la envolvente com un debe de ser extremadamente ine ciente ( CE < 0:1 como para que no se formen CVs con BD secundarias. Finalmente encontramos que las binarias progenitoras de ZACVs con secundarias BD poseen separaciones orbitales < 3AU y masas primarias entre 1 y 10 M con 75% de las masas primarias menores que 1.6 M . Es interesante se~nalar que estos intervalos en separaci on orbital y masa primaria colocan a la mayor a de estas binarias progenitoras dentro del llamado \\desierto de enanas marrones".

  12. 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.

  13. Soft show

    OpenAIRE

    Goitia Cruz, Aitor

    2010-01-01

    El artículo señala la ausencia de debate en torno a la proliferación de arquitecturas-esculturas derivadas de un manierismo sustentado en las nuevas aplicaciones informáticas, capaces de generar geometrías complejas de suaves contornos.

  14. Análisis de las barreras y oportunidades legales-éticas de la comunicación y disculpa de errores asistenciales en España

    Directory of Open Access Journals (Sweden)

    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.

  15. Humans-with-Media en la producción de conocimiento matemático. El caso de Geogebra

    OpenAIRE

    Villa-Ochoa, Jhony; Borba, Marcelo C.

    2011-01-01

    Este documento se usa el constructo teórico Humans-with-Media para analizar una situación construida con el software Geogebra. La situación muestra un posible entendimiento de la función derivada a partir del reconocimiento de la “función tasa de variación”.

  16. Humans-with-media en la producción del conocimiento matemático: el caso de Geogebra

    OpenAIRE

    Villa-Ochoa, Jhony; Borba, Marcelo C.

    2011-01-01

    Este documento se usa el constructo teórico Humans-with-media para analizar una situación construida con el software Geogebra. La situación muestra un posible entendimiento de la función derivada a partir del reconocimiento de la “función tasa de variación”.

  17. PODER Y ESTRATEGIA

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    RAÚL SANABRIA TIRADO

    2008-01-01

    de la formulación e implementación de la estrategia, identificando los diferentes actores que influencian éstos procesos, el papel que juega el conflicto entre intereses particulares y las patologías organizacionales derivadas del abuso y mal uso del poder.

  18. 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.

  19. Sistemas distribuídos aplicados à compressão e recuperação de imagens - DOI: 10.4025/actascitechnol.v30i1.3178

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    Fabio Jorge Assad Gostaldon

    2008-05-01

    Sistemas distribuídos aplicados à compressão e recuperação de imagens by Eduem is licensed under a Creative Commons Atribuição-Uso Não-Comercial-Vedada a Criação de Obras Derivadas 2.5 Brasil License.Based on a work at periodicos.uem.br.

  20. Difusão anômala e equações fracionárias de difusão - DOI: 10.4025/actascitechnol.v27i2.1476

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    Giane Gonçalves

    2005-03-01

    Full Text Available Neste trabalho investigaremos as equações de difusão, usualmente aplicadas na descrição da difusão anômala, que empregam derivadas fracionárias tanto na variável temporal quanto na variável espacial. Em particular, para essas equações obteremos soluções exatas levando em conta uma condição inicial genérica e formularemos uma teoria de perturbação para o estudo de situações mais complexas. Também verificaremos que as derivadas fracionárias, quando aplicadas na parte temporal, possibilitam-nos o estudo de um processo de difusão anômala com o segundo momento finito, i.e., 2> ∝ tα (0 1, correspondendo aos casos, sub e superdifusivo, respectivamente. Em contraste, com a derivada fracionária aplicada na variável espacial que resulta em uma difusão anômala cujo segundo momento não é finito. Complementando o cenário acima, empregaremos o formalismo de caminhantes aleatórios para explorar as implicações obtidas por usar derivadas fracionárias na equação de difusão