A filosofia na formação do educador... Para quê?

Directory of Open Access Journals (Sweden)

Simone dos Santos

2003-01-01

Full Text Available O texto aborda a importância da Filosofia na formação de professores a partir de um referencial teórico crítico. Discute o conceito de Filosofia da Educação enquanto um campo do saber que leva à reflexão radical, rigorosa e de conjunto sobre o campo da Educação em consonância com o pensamento de Saviani (1973 e articula tais idéias com a teoria crítica de Adorno (1995, colocando a Filosofia da Educação como campo de fundamental importância na formação de professores articulados com a possibilidade de emancipação pela educação. El artículo aborda la importancia de la filosofia en la formación de los profesores a partir de un referencial teórico crítico,. Discute el concepto de Filosofia de la Educación como un saber que conduce a la reflexión radical, rigurosa e de conjunto sobre el campo de la educación en consonancia com Saviani(1973 e articula tales ideas com la teoria crítica de Adorno (1995, colocando a Filosofia de la Educación como campo de fundamental importancia en la formación de profesores articulados com la posibilidad de la emancipación por la educación.

LA IMPORTANCIA Y EL NIVEL DE DESARROLLO DE LAS COMPETENCIAS EN PSICOLOGÍA

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Pilar Alonso-Martín

2010-01-01

Full Text Available El objetivo de esta investigación es analizar qué importancia y nivel de desarrollo otorgan a las competencias genéricas, además de observar en qué espacios didácticos reportan haberlas ido adquiriendo y/o desarrollando, así como conocer la organización y planificación de su tiempo de trabajo autónomo. La muestra está compuesta por 83 estudiantes de 3º, 4º y 5º de psicología. Los resultados muestran que el nivel de importancia de las competencias está por encima del nivel de desarrollo alcanzado; los espacios didácticos predominantes son las clases teóricas y las prácticas. El mayor porcentaje de tiempo está dedicado a trabajar en grupo y preparar exámenes. Se han encontrado diferencias significativas en función del sexo, turno y curso. Se plantean sugerencias de mejora para aumentar la calidad docente.

La importancia del bicameralismo como garantía constitucional legislativa

OpenAIRE

Luque Bautista, Richard Jhony

2014-01-01

La investigación "IMPORTANCIA DEL BICAMERALISMO COMO GARANTÍA CONSTITUCIONAL LEGISLATIVA", busca conocer las causas y consecuencias del establecimiento en el Perú del sistema unicameral del poder legislativo y cuál es el balance de su incidencia en la vida peruana. Para tal fin, describimos el proceso histórico seguido por el Estado y la Sociedad peruana, en cuanto concierne a dicho poder del Estado. Ante la actual y creciente deslegitimación de esta modalidad legislativa, que incluso alienta...

Redescubriendo El suelo: Su importancia ecológica y agrícola

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Noé Manuel Montaño

2016-10-01

Full Text Available Redescubriendo el suelo: su importancia ecológica y agrícola es un libro muy completo, actualizado y sin duda será de consulta obligada para quienes hacen investigación edafológica y como material elemental para los cursos de pre- y posgrado de suelo y materias afines, tanto en México como en América Latina.

La importancia de palmas en el oeste de la cuenca Amazónica

DEFF Research Database (Denmark)

Balslev, Henrik

2011-01-01

Las palmas forman un elemento conspicuo y dominante en muchos bosques tropicales en el oeste de la cuenca Amazónica. Existen alrededor de 100 especies de palmas en la zona, y tienen densidades de hasta 8000 individuos por hectárea. Además de su importancia ecológica, las palmas son de gran...

La importancia de los contenidos en la enseñanza

OpenAIRE

Coll Salvador, César; Solé i Gallart, Isabel

1987-01-01

Este artículo defiende la importancia de los contenidos para la enseñanza, en base a tres líneas de argumentación. La primera se refiere al concepto mismo de educación; la opción que se adopte al respecto condiciona indefectiblemente la significación que se atribuya a los contenidos específicos. El segundo argumento apela a la interpretación que desde los postulados de la psicología cognitiva actual se hace del aprendizaje escolar, que cristaliza en la noción de aprendizaje significativo, y l...

Estudios estructurales de la proteína mayoritaria de la cápsida de lentivirus

OpenAIRE

Yélamos López, María Belén

1998-01-01

Los Lentivirus son un grupo de virus, subfamilia de los Retrovirus. Incluyen virus de gran importancia tanto veterinaria, como el virus de la anemia infecciosa equina (EIAV) o el virus de la inmunodeficiencia felina (FIV), como clínica como el virus de la inmunodeficiencia humana (HIV). Nuestro sistema de estudio es la proteína mayoritaria de la cápsida de lentivirus. Las proteínas de las cápsidas lentivirales tienen una gran homología de secuencia. Este alto grado de similitud, junto con la ...

Importancia de las competencias en la formación de enfermería

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Cecilia Latrach-Ammar

2011-01-01

Full Text Available Objetivo: conocer la opinión de los profesionales e internos de enfermería sobre la importancia de las competencias de egreso en la formación de estudiantes para la práctica profesional en la Escuela de Enfermería de la Universidad Mayor de Chile, en el 2008. Método: estudio descriptivo de tipo transversal; la recolección de datos se efectuó mediante una encuesta autoadministrada en dos grupos: internos y profesionales de enfermería. Para el análisis de datos se utilizó estadística descriptiva. En los resultados se observa que los grupos encuestados aprecian que las competencias asistencial, general, educativa y de sello son "muy importantes para el desarrollo profesional"; sin embargo, el grado de importancia varía dependiendo de la función que ejercen los encuestados. Conclusión: la presente investigación permite validar, por parte de los egresados y profesionales, las competencias adquiridas por los estudiantes durante su formación universitaria, las cuales responden a las exigencias laborales y permiten la integración de los profesionales a la gestión académica.

“LA IMPORTANCIA DE LA GENERACIÓN DE CONTENIDOS EN EL CONTEXTO DIGITAL”

OpenAIRE

Neyra Rodríguez, Milagros Rocío

2017-01-01

La investigación tiene como Objetivo: Describir la importancia de la generación de contenidos en el contexto digital. Método: La investigación es de diseño no experimental, de tipo descriptivo. Conclusión: La generación de contenidos comunicacionales va directamente relacionada a los objetivos de producto, marketing, publicitarios, etc. Trabajo de investigacion Revisión por pares

Enfermedades del tejido conectivo: Importancia del diagnóstico precoz

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G. Patricia Abumohor, Dra.

2012-07-01

Full Text Available Las Enfermedades del Tejido Conectivo (ETC son entidades de baja prevalencia en la población general. Son de naturaleza inflamatoria y autoinmune, tienden a la cronicidad y al compromiso de muchos parénquimas, órganos y tejidos, dejando en ellos daño estructural y funcional. Dado lo anterior, amenazan la vida o disminuyen la expectativa y calidad de vida. El diagnóstico y tratamiento precoz de estas entidades, permite cambiar su curso y muchas veces lograr remisión. Es por lo tanto de suma importancia tenerlas en mente y sospecharlas como entidades de enfermedad e iniciar un tratamiento oportuno.

La importancia de la motivación económica

OpenAIRE

Elstein, Daniela

2013-01-01

La motivación es considerada uno de los factores más importantes que desvela, tanto a los Administradores de las empresas, como a los responsables de Marketing. La importancia de la motivación, no será cuestionada en las siguientes líneas, sino que dando uso a las ideas de dos grandes pensadores de la talla de Herzberg y Maslow, buscaremos una respuesta al cómo, cuándo y hasta dónde motivar a nuestro personal. Por medio de tres categorías de motivación y un anexo especial de segmentación de e...

Petroleum systems and hydrocarbon accumulation models in the Santos Basin, SP, Brazil; Sistemas petroliferos e modelos de acumulacao de hidrocarbonetos na Bacia de Santos

Energy Technology Data Exchange (ETDEWEB)

Chang, Hung Kiang; Assine, Mario Luis; Correa, Fernando Santos; Tinen, Julio Setsuo [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Lab. de Estudos de Bacias]. E-mails: chang@rc.unesp.br; assine@rc.unesp.br; fscorrea@rc.unesp.br; jstinen@rc.unesp.br; Vidal, Alexandre Campane; Koike, Luzia [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Centro de Estudos de Petroleo]. E-mails: vidal@ige.unicamp.br; luzia@iqm.unicamp.br

2008-07-01

The Santos Basin was formed by rifting process during Mesozoic Afro-American separation. Sediment accumulation initiated with fluvial-lacustrine deposits, passing to evaporitic stage until reaching marginal basin stages. The analysis of hydrocarbon potential of Santos Basin identified two petroleum systems: Guaratiba-Guaruja and Itajai-Acu-Ilhabela. The Guaratiba Formation is less known in the Santos Basin because of small number of wells that have penetrated the rift section. By comparison with Campos Basin, hydrocarbons are of saline lacustrine origin deposited in Aptian age. Analogous to Campos Basin the major source rock is of saline-lacustrine origin, which has been confirmed from geochemical analyses of oil samples recovered from the various fields. These analyses also identified marine source rock contribution, indicating the Itajai-Acu source rock went through oil-window, particularly in structural lows generated by halokynesis. Models of hydrocarbon accumulation consider Guaratiba Formacao as the major source rock for shallow carbonate reservoirs of Guaruja Formacao and for late Albian to Miocene turbidites, as well as siliciclastic and carbonate reservoirs of the rift phase. Migration occurs along salt window and through carrier-beds. The seal rock is composed of shales and limestones intercalated with reservoir facies of the post-rift section and by thick evaporites overlying rift section, especially in the deeper water. In the shallow portion, shale inter-tongued with reservoir rocks is the main seal rock. The hydrocarbon generation and expulsion in the central-north portion of the basin is caused by overburden of a thick Senonian section. Traps can be structural (rollovers and turtle), stratigraphic (pinch-outs) and mixed origins (pinch-outs of turbidites against salt domes). (author)

Relación estructura-función de la proteína epididimaria de rata "DE", y su potencial uso para el desarrollo de un método de regulación de la fertilidad

OpenAIRE

Ellerman, Diego A.

2001-01-01

La glicoproteína epididimaria de rata "DE" se asocia al espermatozoide durante la maduración, y participa en el proceso de fusión de gametas a través de sitios complementarios presentes en la superficie del ovocito. Con el fin de comprender los mecanismos involucrados en la participación de DE en dicho proceso, se estudió la importancia de la estructura de DE para la actividad de la proteína. El clonado del ADNc de DE permitió obtener la secuencia de los 227 aminoácidos (aa) de la proteína. E...

La importancia de la oralidad en la cultura contemporánea. El caso de

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Lic. María Eugenia Boito

2000-01-01

Full Text Available En el presente trabajo titulado "La importancia de la oralidad en la cultura contemporánea. El caso de "El caldero de los cuenteros en Córdoba" la idea es analizar las manifestaciones de la tradición oral en un grupo cultural de la provincia de Córdoba, observando desde una mirada comunicacional cómo las diferentes expresiones culturales son convocadas por este grupo mediante la oralidad.Esta manifestación cultural fue elegida como objeto de análisis ya que por sus características no participa en ninguno de los tres circuitos culturales que –según los teóricos- caracterizan la dinámica de las culturas urbanas latinoamericanas y nos parece importante abordar la oralidad como componente de cultura latinoamericana. Esta forma de encuentro en donde la tradición cultural de los distintos grupos se hace presente es el objeto de análisis de este trabajo, tratar de comprender la importancia de lo oral en la cultura cotidiana, en las tradiciones propias y ajenas, en definitiva, en el imaginario social de nuestros pueblos.

EPOXIDACIÓN DE OLEÍNA DE PALMA CON ÁCIDO PEROXIACÉTICO FORMADO IN SITU

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ERNESTO ZULETA S

Full Text Available Este artículo presenta los resultados de un proyecto de investigación encaminado a evaluar las condiciones de producción de oleína de palma epoxidada mediante el método de ácido peroxiacético formado in situ. Los aceites epoxidados son sustancias químicas de gran importancia industrial, de uso directo como plastificantes, o como intermediarios en la fabricación de otros productos químicos de mayor valor agregado. Este trabajo realiza un aporte investigativo a nivel regional, brindando una alternativa de uso para la oleína de palma africana mediante su utilización en la obtención de un producto con alta potencialidad de producción y utilidad como son los aceites epoxidados. Bajo las condiciones de estudio, se pudo obtener una oleína de palma epoxidada con un porcentaje de oxígeno oxiranode 3,007%, valor comparable con el valor requerido para un aceite de soya epoxidado comercial según la normatividad nacional

Importancia del patrocinio en relación con los Juegos Olímpicos

OpenAIRE

Manrique Sánchez, Sonia

2016-01-01

RESUMEN: El objeto de estudio de este trabajo es el patrocinio deportivo en general y el patrocinio deportivo relacionado con los Juegos Olímpicos en particular. El estudio sirve para entender el patrocinio deportivo, su importancia y evolución en las Olimpiadas y mostrar lo que supone la realización de la actividad de patrocinio deportivo para las empresas patrocinadoras, quedando latente los beneficios para ambas partes, patrocinado y patrocinador, cuando se realiza dicha actividad. D...

La importancia de los materiales en las viviendas de muy bajo coste

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Salas, Julián

1992-01-01

El texto que sigue se encuadra en el contexto de intentar enmarcar la importancia considerable del capítulo de los materiales de construcción en el subsector de las viviendas de muy bajo coste en los Países en Vías de Desarrollo en general, y en Latinoamérica en particular. El autor trata de cuantificar, en forma global, la repercusión de los materiales en varios supuestos y como ésta aumenta al disminuir —prácticamente desaparecer— las partidas de instalaciones y acabados. De conformidad...

Inhibidores de la paraproteína convertasa subtilisina/kexina tipo 9: una alternativa de manejo para las dislipidemias

OpenAIRE

Beatriz Wills-Sanín; Alejandra Rincón; Ana Cristina Montenegro; Andrés F. Buitrago-Sandoval

2017-01-01

Las guías de la práctica clínica internacionales recomiendan a las estatinas como la terapia de elección para el manejo de la dislipidemia. No obstante, pese a la evidencia acerca de la importancia del manejo de esta condición, existe un porcentaje significativo de los adultos que no logran las metas en los lípidos con las estatinas. Lo anterior ha estimulado el desarrollo de anticuerpos monoclonales que inactivan la paraproteína convertasa subtilisina/kexina tipo 9. Estos medicamentos han si...

Importancia de la gerencia del conocimiento: contrastes entre la teoría y la evidencia empírica

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César Augusto Bernal Torres

2014-01-01

Full Text Available Este estudio analiza la importancia que las organizaciones dan en Colombia a la gerencia del conocimiento, para responder a los retos del actual orden económico mundial. Para ello se aplicó una encuesta a 2.249 personas en 83 organizaciones de diferentes tamaños y sectores de actividad económica, localizadas en la ciudad de Bogotá. En general, los resultados indican que la gerencia del conocimiento no es una práctica usual en estas organizaciones, situación que contrasta desfavorablemente con el alto grado de importancia que las organizaciones en los países desarrollados dan a estas actividades, consideradas como estratégicas para potenciar su capacidad innovadora y competitividad sostenible. Rasgos estos de los que en general adolecen las empresas en Colombia y los cuales son necesarios potenciar.

Importancia de la gerencia del conocimiento: contrastes entre la teoría y la evidencia empírica

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César Augusto Bernal Torres

2014-01-01

Full Text Available Este estudio analiza la importancia que las organizaciones dan en Colombia a la gerencia del conoci- miento, para responder a los retos del actual orden económico mundial. Para ello se aplicó una encuesta a 2.249 personas en 83 organizaciones de diferentes tama ̃ nos y sectores de actividad económica, localiza- das en la ciudad de Bogotá. En general, los resultados indican que la gerencia del conocimiento no es una práctica usual en estas organizaciones, situación que contrasta desfavorablemente con el alto grado de importancia que las organizaciones en los países desarrollados dan a estas actividades, consideradas como estratégicas para potenciar su capacidad innovadora y competitividad sostenible. Rasgos estos de los que en general adolecen las empresas en Colombia y los cuales son necesarios potenciar.

Arteriopatía periférica crónica inducida por cocaína

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Sonia Pankl

2012-02-01

Full Text Available La trombosis periférica aguda inducida por cocaína ha sido descripta en la literatura, siendo una complicación poco común. Si bien existen comunicaciones que reflejan los efectos crónicos de la cocaína sobre el sistema arterial periférico, no hay casos publicados de tal complicación en ausencia de otros factores de riesgo. Se presenta el caso de una mujer de 22 años de edad con antecedentes de consumo de cocaína intranasal de 3 gramos por semana durante un año, que consultó por claudicación intermitente a los 200 metros asociada a dolor y parestesias en miembro inferior izquierdo de 2 meses de evolución. El ecodoppler arterial evidenció una estenosis mayor del 70% en la arteria femoral superficial izquierda. Se realizaron estudios complementarios descartando otras etiologías probables. Se inició tratamiento con ácido acetilsalicílico, cilostazol y ejercicio reglado, asociado a terapia de apoyo para mantenimiento del cese del consumo de cocaína, con buena respuesta. Se destaca la importancia de la difusión de información a los pacientes, dado que la mayoría de la población desconoce las complicaciones cardiovasculares de dicha adicción. Es indispensable indagar sobre el consumo de cocaína en pacientes jóvenes con arteriopatía sin factores de riesgo aparentes.

IMPORTANCIA DE LA POSVENTA EN LA MEZCLA DE MERCADEO ACTUAL

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Ana Prieto Sánchez

2007-07-01

Full Text Available El artículo tiene como objetivo analizar la importancia de la postventa en la mezcla de mercadeo actual. Para lograr este propósito, se utilizó el método de la interpretación de los significados de la información, se llama información a los “datos” recolectados a través de la investigación documental. Se consultaron autores como: Cancer (2005, Kotler (2005, Reyes (2005,Villar (1997, Walther (1997. Con el resultado de la aplicación de este método se procedió a presentar los aspectos relevantes de la investigación: necesidad de la postventa, atención al cliente, postventa como estrategia competitiva, para finalmente plantear un nuevo modelo de organización de postventa.

Importancia económica de los bosques

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Yolanda Chamberlain

2011-09-01

Full Text Available En la actualidad, la población mundial ha adquirido mayor conciencia sobre la importancia de los bosques y su relación con la calidad de vida de las personas. A pesar de lo anterior, la tala indiscriminada continúa y se siguen realizando proyectos que afectan la flora y la fauna de las selvas, sobre todo, en los países menos desarrollados que explotan estos recursos como materia prima.En Costa Rica se ha tratado de mantener cierto control sobre los bosques. Por ejemplo, el 16 de abril de 1996 se publicó en el Diario Oficial La Gaceta, la Ley Forestal No.7575. Dicha Ley dispone una serie de medidas para la conservación de las áreas de protección y de reserva forestal. En el primer caso, se estipulan las distancias requeridas para la protección de las nacientes permanentes, las riberas de ríos, las quebradas o arroyos, las riberas de los lagos y los embalses naturales, las áreas de recarga acuífera y otros. En estas áreas, por ejemplo, no se podrá realizar ningún tipo de construcción ni autorizarse la tala de árboles.

Importancia del marketing digital para las pymes colombianas orientadas a los negocios internacionales

OpenAIRE

Hernández Camacho, Darlly Yuranny; Silva, Juan Manuel

2013-01-01

Este trabajo sigue una secuencia progresiva de lo general, teórico y estratégico a lo específico, práctico y táctico. Así, en primer lugar se hace una introducción a las concepciones del marketing a nivel general, con el fin de introducir al lector en la materia y valorar su importancia, abarcando algunos factores clave que han producido en los últimos años una innovación en los negocios internacionales. This thesis follows a progressive sequence from a general, theoretical and strategic p...

Importancia del manual de los sistemas contables en el sistema de control interno.

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Nicolás Valdés Rodríguez

2007-01-01

La dirección administrativa del país en los últimos 3 años ha insistido en la necesidad de profundizar en los mecanismos de control económico –financiero de las entidades, el presente trabajo va dirigido a contribuir en alguna medida a lograr ese propósito. El sistema contable de una Entidad forma parte indisoluble del Sistema de Control Interno de la misma, por la vinculación tan estrecha que existe entre los mismos. El objetivo fundamental del trabajo ”Importancia del Manual de ...

Diseño y prueba de un cuestionario sobre la importancia percibida de las condiciones de trabajo en México

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Porfirio Tamayo-Contreras

2016-09-01

Full Text Available La percepción de la importancia que el empleado otorga a los distintos aspectos de su trabajo es una base de la representación social que tiene de la empresa en la que labora y de las actitudes hacia su trabajo, como la intención de abandono, que también se relacionan con aspectos no controlables por la empresa. El propósito de este estudio fue diseñar y probar un cuestionario para medir la importancia que los trabajadores conceden a los aspectos laborales e identificar su relación con la intención de abandonar la organización. El cuestionario se aplicó a 447 trabajadores (282 hombres y 165 mujeres de empresas exportadoras de calzado de la ciudad de León, Guanajuato, México. Mediante un análisis factorial se identificaron cinco factores; la consistencia interna fue adecuada en todos los casos y la discriminación de todos los ítems resultó en la dirección esperada. La percepción sobre los factores del trabajo varió en importancia y no se relacionó con la intención de abandono, aunque un aspecto no controlable por la empresa (mejor salario reveló indicios de una relación sobre la intención de abandono.

Importancia de los lipopéptidos de Bacillus subtilis en el control biológico de enfermedades en cultivos de gran valor económico

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Franklin Eduardo Sánchez Pila

2016-09-01

Full Text Available Se determinaron los avances en el control biológico de enfermedades en cultivos de importancia económica, en donde Bacillus subtilis tiene un rol preponderante, puesto que sus lipopéptidos demuestran su efectividad al momento de controlar un rango muy amplio de enfermedades que atacan a los cultivos de mayor importancia en nuestro país y en el mundo. En los tres cultivos analizados se dan detalles de la efectividad de Basillus subtilis para el control de las enfermedades más devastadoras. En Magnaporthe ryzae se determina que la severidad puede ser detenida con gran efectividad, por lo que será necesario ampliar la experimentación hacia la protección de la semilla del arroz. Para Rhizoctonia solani los resultados exhibidos son muy alentadores. Esta enfermedad es de mucha importancia no solo en el cultivo de papas, sino que en toda la variedad de solanáceas y leguminosas cultivadas principalmente en el callejón interandino. En tanto que para Mycosphaerella fijiensis se detallan excelentes resultados ante un patógeno extremadamente agresivo y que su control trae grandes impactos en la población y en el ambiente. Ante lo manifestado el Bacillus subtilis se perfila como uno de los principales agentes biocontroladores para lograr un correcto manejo fitosanitario de los cultivos de mayor importancia en nuestro medio.

La educación ambiental y su importancia en la relación sustentable: Hombre-Naturaleza- Territorio

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Ronald Fernando Quintana Arias

2017-01-01

Full Text Available Objetivo. Promover la importancia de la educación ambiental en el fortalecimiento de la relación sustentable Hombre-Naturaleza-Territorio en 8 niños y niñas observadores de aves de la primaria María Berchmans. Metodología. Entre agosto y noviembre del 2015 desarrollé un estudio de caso basado en el aprendizaje vivencial, social y experiencial, que se dividió en dos fases en las que se encontraban 19 actividades clasificadas dentro de siete categorías. Resultados. El desarrollo tanto de habilidades cognitivas “duras” como de habilidades socioemocionales “blandas” exponiendo diferentes ambientes educacionales, incentiva un aprendizaje activo que fortalece la relación sustentable Hombre-Naturaleza-Territorio. Conclusión. La generación de una conciencia de conservación ambiental al contemplar la importancia de la educación escolar en la relación Hombre-Naturaleza-Territorio lleva a la apropiación de la biodiversidad (natural-cultural y a generar aprendizajes significativos.

Lactosuero: importancia en la industria de alimentos.

OpenAIRE

Parra Huertas, Ricardo Adolfo

2011-01-01

El lactosuero de quesería es un subproducto líquido obtenido después de la precipitación de la caseína durante la elaboración del queso. Contiene principalmente lactosa, proteínas como sustancias de importante valor nutritivo, minerales, vitaminas y grasa. La composición y tipo de lactosuero varía considerablemente dependiendo del tipo de leche, tipo de queso elaborado y el proceso de tecnología empleado. La lactosa es el principal componente nutritivo (4,5 % p-v), proteína (0,8% p/v), y lípi...

Recuperación de fenol de aguas residuales industriales por tratamiento con NaCl

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Iveth Serna

2003-01-01

Full Text Available En el presente trabajo se explora una técnica para la recuperación de fenol de aguas residuales que hasta el momento se ha realizado en forma empírica en algunas industrias locales. Se realizó un diseño experimental donde se tomó la concentración de NaCl como variable de entrada del proceso y el porcentaje de recuperación de fenol como variable de salida. El análisis estadístico de los datos muestra que la concentración de NaCl es una variable de suma importancia en el proceso. Se determinó que el mejor punto de operación está a 25º C, con un pH inicial entre 2 y 3, una concentración inicial de fenol de 6% y concentración inicial de NaCl de 21,5%, logrando una recuperación del fenol del 79 % con una concentración de fenol en la fase orgánica del 83 %. Además de la parte experimental, en el trabajo se exponen algunas teorías desarrolladas acerca de la separación de una solución de no electrolito y agua por adición de sal.

Importancia de la potencia y la hipótesis en el valor p

OpenAIRE

Cortés Martínez, Jordi; Casals, Martí; Langohr, Klaus; González Alastrué, José Antonio

2015-01-01

Los lectores de Medicina Clínica conocen bien la importancia de definir bien el denominador de una proporción para estimar una probabilidad: “No es lo mismo la probabilidad de que un católico sea Papa que la de que un Papa sea católico”. De forma similar, en un diagnóstico, no es lo mismo la probabilidad de que un enfermo dé positivo (sensibilidad), que la de que un caso que ha dado positivo esté enfermo (valor predictivo de un positivo). El valor p (o valor de p, o p-valor, o simplement...

Importancia del apoyo familiar en el control de la glucemia

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RODRÍGUEZ-MORÁN MARTHA

1997-01-01

Full Text Available Objetivo. Determinar la importancia del apoyo familiar en el control de la glucemia en diabéticos no insulino dependientes. Material y métodos. Se diseñó un estudio de casos y controles, considerando como casos a los pacientes con glucemia o = 140 mg/dl. El apoyo familiar se determinó con el cuestionario Environmental Barriers to Adherence Scales, que estima el apoyo otorgado para que el paciente siga las indicaciones terapéuticas. Se incluyeron 32 casos y 50 controles. Resultados. El apoyo familiar que recibe el paciente se asocia significativamente a la presencia de glucemia <140 mg/dl (razón de momios = 3.9; IC95% 1.4-11.1. Las demás variables no mostraron asociación significativa. Conclusiones. El apoyo familiar que reciben los enfermos influye en el control de la glucemia.

Importancia de los aspectos psicosociales en la enfermedad celíaca

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Trini Fragoso Arbelo

2002-06-01

Full Text Available Se revisan los conceptos clínicos actuales sobre la enfermedad celíaca. Se definen con precisión los términos enfermedad celíaca activa, silente, latente y potencial. Se enfatiza en los aspectos psicosociales que influyen en su tratamiento y se trazan pautas generales acerca del manejo integral de los pacientes afectados, dada la importancia de la dieta sin gluten de por vida como único tratamiento.The current clinical concepts of celiac disease are reviewed. The terms active, silent, latent and potential related to celiac disease are accurately defined. Emphasis is made on the psychosocial aspects influencing its treatment and general guidelines are drawn on the comprehensive management of the patients suffering from this disease, given the importance of diet without gluten as the only lifelong treatment.

LA HIDROXIAPATITA, SU IMPORTANCIA EN LOS TEJIDOS MINERALIZADOS Y SU APLICACIÓN BIOMÉDICA

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Margarita Victoria García-Garduño; José Reyes-Gasga

2006-01-01

La hidroxiapatita en los tejidos mineralizados reviste una gran importancia ya que se ha demostrado que es un material biocompatible, con aplicación biomédica en Odontología, Ortopedia y Cirugía Máxilofacial. Es el cristal principal de huesos y dientes ya que les confiere su dureza característica y, acompañado por la colágena, los huesos presentan determinada elasticidad. En la naturaleza se le encuentra formando parte de rocas metamórficas. En los tejidos vivos, la hidroxiapatita y sus precu...

Importancia de los estudios fisiológicos en los cultivos de flores de exportación

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Orozco de Amézquita Martha

1992-12-01

Full Text Available La Fisiologla Vegetal estudia el funcionamiento de las plantas y los procesos vitales que regulan su crecimiento, desarrollo y producción. En últimas, las respuestas de los vegetales dependen de lo que ocurre a nivel molecular, de organelos subcelulares, de células, de tejidos y órganos y de las
interrelaciones entre ellos, todo ésto modulado por
las condiciones ambientales. De la anterior definición, se deduce la importancia que tiene la investigación de los procesos fisiológicos en el desarrollo de la floricultura. En la actualidad, el manejo de plantas productoras de flores bajo
invernadero en la Sabana de Bogotá está basado en el interés de los floricultores por mejorar y aumentar
la calidad de la producción, lo cual ha originado un importante conocimiento emplrico, acompañado del empleo de técnicas recomendadas por expertos internacionales, que han suplido
los requerimientos necesarios para la producción. Por lo anterior, Arbeláez (1985 opina que un aspecto de vital importancia en el desarrollo futuro de la industria de flores será el poder contar con investigación suficiente que genere la tecnologla adecuada a las necesidades y condiciones colombianas.

Importancia de la educación para la salud bucal en niños escolares

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Rossitto, Franco Luciano

2017-01-01

En conjunto con los alumnos de OPS de la Facultad de Odontología, en la localidad de Lisandro Olmos, se llevaron a cabo charlas educativas con el fin de enseñar y concientizar a los niños en su primera etapa escolar sobre la importancia que tiene el cuidado de nuestra salud bucal, como se debe realizar una prevención adecuada y a la vez con la intención de que se transmita lo aprendido a futuras generaciones.

La Vitamina D y su Importancia en la Salud Humana

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David Vásquez Awad

2013-09-01

Full Text Available En los últimos años, la vitamina D ha cobrado una importancia creciente en razón de que, además de sus beneficios reconocidos sobre el hueso, ha mostrado claros efectos benéficos en enfermedades crónicas, graves y altamente prevalentes como hipertensión, cáncer, síndrome metabólico,diabetes y esclerosis múltiple; igualmente, estados fisiológicos como el embarazo, la adolescencia y el envejecimiento se ven beneficiados, y sus eventuales adversidades mitigadas, si se mantienen niveles adecuados de 25 hidroxi-vitamina D que debieran estar en más de 40 ng/mL. Muy importante resulta entonces la suplementación con vitamina D en muchas situaciones fi siológicas o patológicas y en las dosis adecuadas, las cuales pueden situarse en el rango de 1000 a 2000 UI diarias, con la adherencia requerida para lograr los resultados óptimos que se persiguen.

La importancia de la visualización en el aprendizaje de conceptos matemáticos

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Gatica, Stella Nora; Ares, Óscar Enrique

2012-01-01

En los últimos tiempos, el estudio de la visualización en el pensamiento matemático es objeto de numerosas investigaciones, en parte, posiblemente, debido al surgimiento de la computadora como un recurso didáctico para la comprensión de conceptos matemáticos. Este trabajo tiene como objetivo reflexionar sobre la importancia de poder relacionar e interpretar imágenes visuales (utilizando manipulables virtuales) con la información que está dada en forma simbólica. Presentamos una propuesta didá...

La importancia del pensamiento estadístico en la Ingeniería de Fiabilidad

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Raquel Caro; Fernando García Jiménez

2012-01-01

Existe de modo creciente una notable inquietud por el control de la calidad en el tiempo, lo que ha dado lugar a la búsqueda de métodos capaces de abordar eficazmente el análisis de la fiabilidad. Los estudios de Grado y Máster de Ingeniería suelen ofrecer asignaturas tales como Estadística, Estadística Industrial, Control y Gestión de la Calidad o similares, donde se estudia la importancia de la fiabilidad y la calidad de los sistemas. En el ejercicio de sus atribuciones los ingenieros deber...

EL NIÑO QUE RONCA: IMPORTANCIA Y MANEJO

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Dr. Selim Abara

2017-01-01

Full Text Available El ronquido en los niños es el signo más frecuente de trastorno respiratorio del sueño (TROS. La importancia de estos trastornos reside en su alta prevalencia y las morbilidades asociadas, como trastornos neurocognitivos, rendimiento escolar deficiente, disfunción conductual, complicaciones cardiovasculares, consecuencias metabólicas y mala calidad de vida relacionada con la salud. La sospecha clínica se basa en una buena anamnesis y examen físico, aunque en muchos casos es insuficiente para afirmar o descartar la existencia de un TROS; por esta razón es importante contar con pruebas específicas, entre las cuales la polisomnografía es el estándar de oro, pero es necesario establecer criterios para indicar estos exámenes debido a su disponibilidad limitada y a su elevado costo. La adenotonsilectomía es el tratamiento más común de TROS en los niños, sin embargo, el grupo de pacientes con comorbilidad de mayor complejidad requiere un estudio más completo y un tratamiento multidisciplinario. En esta revisión se actualizan los conocimientos acerca de los TROS y su manejo. Se propone un diagrama de flujo para el estudio y manejo de un niño que ronca.

Restricciones de liquidez en microempresas y la importancia del financiamiento informal en Baja California

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Martín Ramírez-Urquidy

2009-01-01

Full Text Available La estructura industrial de México incorpora una proporción significativa de agentes que emprenden negocios a escalas reducidas y en un esquema de informalidad. Esta condición los aleja de los mercados formales de crédito, por lo que enfrentan una restricción permanente de liquidez. Este artículo prueba la hipótesis de que existen microempresas (MES no restringidas a pesar de esta limitación formal. Los resultados ilustran esta posibilidad al encontrar, en una muestra de mes del estado de Baja California, lo que implica el acceso a financiamiento externo y la importancia de las fuentes informales.

IMPORTANCIA DEL COMERCIO ELECTRÓNICO Y SU INCIDENCIA EN LA LOGÍSTICA DE APROVISIONAMIENTOS

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María Mitre Aranda

2004-07-01

Full Text Available

El trabajo recoge la importancia y evolución del comercio electrónico desde su concepción tradicional hasta su aplicabilidad vía internet. Se examinan las ventajas e inconvenientes de la red como soporte del comercio electrónico y se pormenoriza sobre la problemática y las ventajas e inconvenientes que el uso del comercio electrónico produce en las actividades logísticas, en general, y en las de compras, en particular.

La importancia del <

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Guerrero, Jose Felipe; Abad, Juan Carlos; Aguera, Emilia Del

2010-01-01

La percepcion sobre el pais de origen de un producto es uno de los principales determinates de la evaluacion y eleccion de dicho producto, sobre todo en los mercados foraneos. En la literatura de marketing existen multiples trabajos que han analizado este aspecto, si bien la amyor parte de ellos se han centrado en productos duraderos de alta implicacion. Este trabajo analiza la importancia que el atributo pais de origen tiene en el proceso de evaluacion del consumidor para el caso de la compr...

Importancia del trabajo de enfermería en la clasificación. Una revisión bibliográfica

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Blanco Jiménez, Soledad

2017-01-01

Cartel presentado en el 3er Congreso Internacional de Comunicación en Salud (3ICHC), celebrado los días 19 y 20 de octubre de 2017 en la Universidad Carlos III de Madrid. El objetivo de este trabajo conocer la importancia del triaje o clasificación de pacientes en la atención segura proporcionada al paciente.

Importancia de la coordinación entre el comedor escolar y las familias en Cantabria.

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Río-Sánchez, Sonia

2013-01-01

Actualmente por los diferentes estilos de vida que se llevan en nuestra sociedad, cada vez se da menos importancia al momento de la comida, muchas veces por falta de tiempo y otras de interés, por lo que los niños pueden llegar a tener una mala alimentación. La mala alimentación en edades tempranas puede ser la causa y el inicio de muchos problemas en el desarrollo del niño/a, como por ejemplo la obesidad infantil. Por eso es muy importante inculcar buenos hábitos alimenticios desde las pr...

Taxonomía e importancia clínica de las nuevas familias del orden Chlamydiales

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MARTÍNEZ T., M. ANGÉLICA; DIOMEDI P., ALEXIS; KOGAN A., RICARDO; BORIE P., CONSUELO

2001-01-01

Esta revisión comprende los cambios trascendentales que se han producido recientemente en la taxonomía de clamidias, la importancia clínica de las nuevas especies del orden Chlamydiales y los métodos para su identificación. La nueva clasificación del orden Chlamydiales se basa en las características fenotípicas, antigénicas, rango de huésped y análisis filogenético del operón ribosomal y proporciona un procedimiento consistente para la identificación de las actuales especies y el establecimie...

FACTOR NUCLEAR kB (NF-kB: SIGNALOSOMA Y SU IMPORTANCIA EN ENFERMEDADES INFLAMATORIAS Y CÁNCER

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Nancy P. Echeverry R.L

2008-04-01

Full Text Available El factor nuclear kB (NF-kB es un dímero constituido por proteínas de la familia Rel. El NF-kB se encuentra en el citoplasma unido a proteínas inhibidoras (IkB. Las IkB son fosforiladas por diferentes cinasas que hacen parte del signalosoma como las cinasas de IKKa e IKKb y el modulador esencial de NF-kB (NEMO, la proteína cinasa activadora de mitosis (MAPK o p38 y la cinasa inductora de NF-kB (NIK. Estas cinasas al ser activadas por señales dependientes de citocinas y luz ultravioleta, fosforilan las IkB provocando su ubiquitinación, su degradación por proteosoma y la subsecuente liberación y translocación al núcleo de NF-kB. Recientemente se le ha dado una gran importancia al NF-kB en la vía de señalización desencadenada por estrés oxidativo, estrés genotóxico y daño en el DNA. A diferencia de la vía denominada clásica, en esta ruta ocurre una SUMOilación de NEMO y translocación al núcleo. En el núcleo NEMO interactúa con la proteína de la ataxia telangiectasia mutada (ATM activada en respuesta a modificaciones en la cromatina y daño en el DNA. El complejo ATM/NEMO es translocado al citoplasma donde la ATM fosforila a las IKK llevando a la ubiquitinación y posterior liberación de NF-kB que es translocado al núcleo. NF-kB desencadena procesos de supervivencia incluyendo el aumento de la transcripción de enzimas antioxidantes como la superóxido dismutasa, catalasa y glutatión. Estas enzimas participan en el control de los niveles de especies reactivas de oxígeno en la célula. La sobreactivación de NF-kB se relaciona con inflamación y cáncer. En la actualidad se desarrolla una búsqueda de fármacos que actúen sobre moléculas del signalosoma de NF-kB, no sólo para el manejo de enfermedades inflamatorias sino también para el uso durante el tratamiento de tumores resistentes a radio y quimioterapia.

A Escola de Veterinaria na Universidade de Santiago

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Barral Martínez, Margarita

2002-12-01

Full Text Available Although Eugenio Montero Ríos was one of the big onQS primates of the system of dominance by the local boss developed during the stage of the Restoration, his patronage paper in Santiago's city and of patronage in the University of Santiago had a considerable importance, an unknown topic, or even forgotten by all the negative connotations with those that commonly and in a simplistic way they associate to the term cacique. The University of Santiago grew beside the protection that Montero lent him since representative of this district had left in 1886 and his strong influence in the central Government from Madrid it allowed him to reach momentous concessions for this institution, like it has been the case of the School of Veterinary Science.

[gl] Aínda que Eugenio Montero Ríos foi un dos grandes primates do caciquismo desenvolvido durante a etapa da Restauración, o seu papel de padroado na cidade de Santiago e de mecenado na Universidade compostelá tiveron unha importancia considerable, un tema descoñecido ou mesmo esquecido por tódalas connotacións negativas coas que comunmente e de xeito simplista se asocian ó termo cacique. A Universidade de Santiago medrou ó carón da protección que lie prestou Montero dende que saíra representante deste distrito en 1886 e a súa forte influencia no Gobernó central de Madrid permitiulle acadar concesións trascendentais para dita institución, como foi o caso da Escola de Veterinaria.

A importância da saúde bucal para adolescentes de diferentes estratos sociais do município de Ribeirão Preto La importancia de la salud bucal para los adolescentes de diferentes estratos sociales del municipio de Ribeirão Preto The importance of bucal health for adolescents of different social strata of Ribeirão Preto

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Marina Sá Elias

2001-01-01

Full Text Available O objetivo do presente estudo é conhecer a importância da saúde bucal para adolescentes de diferentes estratos sociais, identificando a importância da estética dental, e o cuidado que estes dispensam em relação a sua saúde bucal. O processo metodológico adotado nesta investigação é de natureza qualitativa, utilizando como técnica de coleta de dados a entrevista semi-estruturada. Conhecemos a importância da saúde bucal em vários contextos de suas vidas, como na aparência pessoal, na sexualidade, no emprego, e na saúde geral. Esta investigação permite-nos conhecer as motivações para os adolescentes preservarem sua saúde bucal, o que acreditamos ser muito válido no intuito de desenvolvermos a promoção de saúde através da educação em saúde.El objetivo del presente estudio es conocer la importancia de la salud bucal para los adolescentes de diferentes estratos sociales, identificando la importancia de la estética dental y el cuidado que estos realizan en relación con su salud bucal. El proceso metodológico adoptado en esta investigación es de naturaleza cualitativa, utilizando como técnica de recolección de datos la entrevista semi-estructurada. Conocimos la importancia de la salud bucal en varios contextos de sus vidas, como en la apariencia personal, en la sexualidad, en el empleo y en la salud en general. Esta investigación nos permitió conocer las motivaciones que tienen los adolescentes para preservar su salud bucal, lo cual creemos será muy valioso en desarrollar programas de promoción de la salud a través de la educación en salud.The objective of the present study is to know the importance of buccal health for adolescents of different social strata, identifying the importance of dental aesthetics, and the care that these students take in relation to their buccal health. The methodological process adopted in this investigation is of qualitative nature, using as technique of collection of data the semi

Inhibidores de la paraproteína convertasa subtilisina/kexina tipo 9: una alternativa de manejo para las dislipidemias

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Beatriz Wills-Sanín

2017-07-01

Full Text Available Las guías de la práctica clínica internacionales recomiendan a las estatinas como la terapia de elección para el manejo de la dislipidemia. No obstante, pese a la evidencia acerca de la importancia del manejo de esta condición, existe un porcentaje significativo de los adultos que no logran las metas en los lípidos con las estatinas. Lo anterior ha estimulado el desarrollo de anticuerpos monoclonales que inactivan la paraproteína convertasa subtilisina/kexina tipo 9. Estos medicamentos han sido aprobados como adyuvantes a la dieta y a las dosis máximas toleradas de la estatina para la hipercolesterolemia familiar o la aterosclerosis clínica en pacientes que requieren disminución adicional de las lipoproteínas de baja densidad. En este artículo revisaremos la evidencia actual acerca de los anticuerpos anti-paraproteína convertasa subtilisina/kexina tipo 9 con el objetivo de optimizar el tratamiento clínico de nuestros pacientes.

Hongos de importancia agrícola presentes en moscas de la fruta del valle de Ica, Perú

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Carlos E. Tipismana

2013-05-01

Full Text Available El objetivo del presente trabajo fue aislar e identificar hongos de especímenes de moscas de la fruta de los géneros Ceratitis (Macleay y Anastrepha (Schiner, del valle de Ica, Perú. Se aislaron hongos pertenecientes a los géneros Alternaria, Aspergillus, Cladosporium, Mucor, Penicillium, Rhizoctonia, Rhizopus y Trichoderma;así como levaduras y micelios estériles. Los recuentos de hongos presentaron rangos entre 8x103 a 8x104 UFC/g para el género Ceratitis; y 7x103 a 7x104 UFC/g para el género Anastrepha. El IVI% (Índice de Valor de Importancia demostró que Cladosporium es el género con mayor valor ecológico con un 78,05%. El Índice de Similitud de especies de hongos entre ambos géneros de mosca de la fruta analizados fue 0,5. Los resultados obtenidos confirman la presencia de hongos en moscas de la fruta; y se deduce el posible impacto de estos dípteros en el área agrícola como potenciales agentes vectores de enfermedades fúngicas para los cultivos locales de importancia económica.

La educación ambiental y su importancia en la relación sustentable: Hombre-Naturaleza- Territorio

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Ronald Fernando Quintana Arias

2017-01-01

Objetivo. Promover la importancia de la educación ambiental en el fortalecimiento de la relación sustentable Hombre-Naturaleza-Territorio en 8 niños y niñas observadores de aves de la primaria María Berchmans. Metodología. Entre agosto y noviembre del 2015 desarrollé un estudio de caso basado en el aprendizaje vivencial, social y experiencial, que se dividió en dos fases en las que se encontraban 19 actividades clasificadas dentro de siete...

Importancia cuantificada de los síntomas sutiles de amenaza de parto pretérmino

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Ernesto Rosell Juarte

2000-06-01

Full Text Available Se realizó un estudio de casos y controles, para valorar la importancia cuantificada de los síntomas sutiles de amenaza de parto pretérmino desde octubre de 1993 hasta abril de 1997 en 9 municipios de la provincia Camagüey. Fueron estudiados 364 casos y 654 controles a partir de los registros oficiales de atención perinatal, complementados con una encuesta. Para el procesamiento de los datos se utilizaron métodos univariados, bivariados y el multivariado de regresión logística. La presencia de los síntomas sutiles fueron: incremento o cambios en las pérdidas vaginales, dolor o presión lumbar en las caderas, dolor abdominal bajo, las contracciones uterinas y los retortijones abdominales. Todos estuvieron asociados al nacimiento pretérmino en ese orden, y fueron las contracciones uterinas las que ocuparon el cuarto lugar en importanciaA case-control study was conducted to assess the quantitated importance of the subtle symptoms of threatened preterm delivery from October, 1993, to April, 1997, in 9 municipalities of the province of Camagüey. 364 cases and 654 controls were studied based on the official registries of perinatal care complemented with a survey. Univariate and bivariate methods and the multivariate of logistic regression were used to process the data. The presence of the subtle symptoms was characterized by: increase or changes in the vaginal losses, lumbar pain or pressure in the hips, low abdominal pain, uterine contractions and abdominal gripes. All of them were associated with preterm birth in that order. Uterine contractions were in the fourth place in importance

Synthesiomyia nudiseta (Diptera: Muscidae) y su importancia en Entomología Forense e investigación aplicada

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Ivorra Cazorla, Tania

2016-01-01

Synthesiomyia nudiseta (van der Wulp, 1883) es un múscido de origen tropical y subtropical, siendo la única especie conocida dentro del género Synthesiomyia Brauer & Bergenstamm, 1893. Se trata de una especie con gran importancia forense para la estimación del intervalo postmortem, en diferentes zonas del mundo (p. ej.: Costa Rica, Estados Unidos, India, Malasia, Tailandia). Su presencia en España y Europa es relativamente reciente y en los últimos años se ha citado con cierta frecuencia en a...

IMPORTANCIA Y DESAFÍOS DE LA CONSERVACIÓN DE Vanilla spp. (ORQUIDACEAE EN COSTA RICA

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Jos\\u00E9 Bernal Azofeifa-Bola\\u00F1os

2014-01-01

Full Text Available El objetivo de este trabajo fue describir la importancia y los principales retos del uso, manejo y conservación del género Vanilla en Costa Rica. Los temas tratados fueron: taxonomía en el país y a nivel mundial, datos sobre recolección y nuevas estimaciones de parientes silvestres, la importancia económica, ecológica y social, el acervo genético de las especies costarricenses, la situación del cultivo a nivel mundial (área cosechada, producción, rendimiento, principales países productores, causas que disminuyen el potencial productivo de las especies, los métodos de cultivo, la posibilidad de extinción de Vanilla planifolia y el potencial genético existente en el país respecto a la concentración de vainillina. Se expone una estrategia integral de conservación que pretende perpetuar los recursos fitogenéticos de vainilla en bancos de germoplasma a través de un sistema formal de producción de semillas, para su utilización ulterior con fines de mejoramiento, investigación y producción comercial. Además, mediante un uso sustentable se protegerán las especies y variedades costarricenses. Las personas, físicas o jurídicas, que utilicen dicho material deberán generar a los proveedores beneficios monetarios, o no monetarios, por el uso de los recursos a través de un sistema justo y equitativo. Las condiciones agroecológicas de Costa Rica así como el material genético de vainilla tanto silvestre como cultivado abren la posibilidad de desarrollar modelos productivos basados en la agricultura orgánica.

Estructura e importancia de la cadena productiva y comercial de la miel en México

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Miguel Ángel Magaña Magaña

2012-01-01

Full Text Available Los objetivos fueron analizar la importancia socioeconómica de la cadena productiva y del proceso comercial de la miel en México, así como examinar la problemática e influencia que dicho proceso ejerce en apicultor, en particular sobre el comportamiento de los precios, el valor generado y su distribución. Se utilizaron como marco metodológico y teórico los fundamentos del comercio interregional y de la economía de los mercados agrarios, los cuales permiten analizar la integración y relación entre los niveles de mercado. Se encontró que la importancia socioeconómica de la apicultura se limita principalmente a su aporte de divisas y generación de empleos e ingresos en el medio rural. El principal canal de comercialización de la miel a granel lo conforman el apicultor, los acopiadores rurales, la empresa comercializadora mayorista y el agente comercial internacional. La producción y comercialización de miel está integrada para su acopio, proceso y entrega al comercializador externo o, en su caso, su distribución al mercado interno, pero con limitado beneficio al apicultor. La cosecha y oferta de miel en el mercado se concentra en pocos meses; esta situación y la necesidad de liquidez de los productores, favorece la ventaja de apropiación de valor que tienen los otros eslabones de la cadena, en especial el mayorista, quien determina el precio. Así, el valor que se agrega a la miel en la cadena productiva y comercial no se distribuye equitativamente, y su diferencia estriba en la capacidad de apropiación o poder de mercado de cada participante.

Importancia de la traducción e interpretación de idiomas para las empresas exportadoras de cacao

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Martinetti Macias, Nicole; Chóez Ortega, Miriam

2015-01-01

El presente trabajo analiza la importancia del servicio de traducción e interpretación en las negociaciones internacionales por parte de las empresas ecuatorianas exportadoras, considerando que en la actualidad existe un mayor interés por parte de los productores locales por captar un porcentaje de mercado en Asia. De acuerdo a este hecho uno de los aspectos importantes es el papel del traductor y del intérprete en la comunicación con los importadores. Sin embargo, las empresas del sector ...

La importancia del pensamiento estadístico en la Ingeniería de Fiabilidad

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Raquel Caro

2012-10-01

Full Text Available Existe de modo creciente una notable inquietud por el control de la calidad en el tiempo, lo que ha dado lugar a la búsqueda de métodos capaces de abordar eficazmente el análisis de la fiabilidad. Los estudios de Grado y Máster de Ingeniería suelen ofrecer asignaturas tales como Estadística, Estadística Industrial, Control y Gestión de la Calidad o similares, donde se estudia la importancia de la fiabilidad y la calidad de los sistemas. En el ejercicio de sus atribuciones los ingenieros deberían desarrollar una nueva forma de pensar. El pensamiento estadístico es una manera de pensar, de comportarse, de actuar, de trabajar, de interacción con otros.

La Importancia del Intangible en la Empresa de Internet: Una Propuesta de Medición Contable

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Federico Fuentes Martín

2005-04-01

Full Text Available En el presente documento de trabajo se analiza la importancia de intangible en el valor de la empresa de Internet y por tanto en la obtención de financiación para la misma, la problemática de su contabilización, así como un estudio empírico en el que se propone la aplicación de una metodología basada en las técnicas operativas proporcionadas por la teoría de los subconjuntos difusos, a la identificación, y posterior tratamiento de los intangibles generadores de ventaja competitiva y su inclusión en un "balance invisible.

LA IMPORTANCIA DE LOS EJES DE FIJACIÓN DEL PAISAJE URBANO EN LA EDUCACIÓN VIAL

OpenAIRE

Nina, Mónica Marianela; Filippeti, Rosana; Pauletto, Selva del Valle

2012-01-01

La enseñanza de los ejes de fijación en el espacio urbano son elementos que deben ser vinculados con la educación vial ya que la misma no forma parte del diseño curricular en la educación formal. El propósito del presente trabajo es que a través de la enseñanza de las funciones de las arterias de circulación como calles, avenidas, rutas, autopistas se busca la toma de conciencia de los jóvenes de la importancia de conocer los principios de la educación vial para prevenir los accidentes de trá...

A JUVENTUDE, O CURRICULO E A GESTÃO PEDAGÓGICA NA EDUCAÇÃO DE JOVENS E ADULTOS

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Thiana do Eirado Sena de Souza

2016-05-01

Full Text Available O processo de juvenização da Educação de jovens e adultos tem sido cada vez maior nos sistema de educação no Brasil. O presente artigo visa compreender como está sendo gestado o trabalho pedagógico para atender as especificidades de um público que teve acesso a escola, mas dela evadiu antes de concluir a educação básica e, que por motivos e razões diversas, mas por ainda acreditar no valor da escola, retorna em busca da conclusão e/ou certificação da educação básica. A pesquisa, de abordagem qualitativa, foi realizada em uma escola quilombola da rede estadual de ensino da Bahia e contou com a entrevista narrativa para a construção dos dados. Foram entrevistados 06 jovens da EJA juvenil e a coordenadora pedagógica. As conclusões assinalam para a importancia de a escola considerar, na gestão e organização curricular, as demandas dos jovens, bem como as questões geracionais presentes na EJA atualmente.

Continuing Vocational Training in Local Government in Portugal, 2000-05--What Has Changed?

Science.gov (United States)

Cabrito, Belmiro Gil; Simao, Ana Margarida Veiga; Alves, Mariana Gaio; Almeida, Antonio

2009-01-01

Local government in Portugal had a good opportunity to modernise through the Programa de Formacao para as Autarquias Locais (Foral) [Training programme for local authorities], implemented between 2000 and 2005. Substantial financial resources were made available through the programme to retrain local government human resources in order to improve…

Importancia de la microbiota gastrointestinal en pediatría

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V P Zamudio-Vázquez

2017-01-01

Full Text Available Las enfermedades del tubo gastrointestinal forman parte importante de la morbilidad y de la mortalidad mundiales; incluyen desde las enfermedades infecciosas, alérgicas, inflamatorias crónicas (como la enfermedad de Crohn y la colitis ulcerativa hasta padecimientos considerados como funcionales, como el síndrome de intestino irritable. En algunas de ellas el tratamiento puede ser difícil, ya que en ocasiones pueden existir diferentes teorías en relación a las mismas y en las que se han encontrado múltiples factores tanto psicosociales como genéticos. En los últimos años ha cobrado gran importancia el papel que desempeña la microbiota intestinal en la génesis de algunas de ellas.   Desde el siglo XV se describió la presencia de microorganismos en el tubo gastrointestinal, pero fue hasta que se originó la biología molecular cuando se logró un mejor conocimiento de la función y la composición del ecosistema gastrointestinal, el cual contribuye de manera importante para los procesos de digestión y absorción de sustratos de la dieta, así como para las funciones inmunológicas y protectoras de la microbiota gastrointestinal en cada organismo, lo que resulta esencial para comprender su participación en el tratamiento y en la prevención de múltiples enfermedades.

Distribución actual e importancia epidemiológica de las especies de triatominos (Reduviidae: Triatominae en Colombia

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Jorge A. Molina

2000-12-01

Full Text Available Se presenta la distribución geográfica y la importancia epidemiológica en la transmisión de la enfermedad de Chagas de las 23 especies de triatominos presentes en Colombia, tomando como base los registros bibliográficos existentes en el pais y las colecciones de referencia del Laboratorio de Entomologia del Instituto Nacional de Salud y del Centro de Investigaciones en Microbiologia y Parasitologia Tropical de la Universidad de los Andes; además, se realiza un análisis de las condiciones ecológicas en las cuales han sido registrados triatominos en los paises con fronteras con Colombia para poder establecer la presencia de posibles especies que aún no se han registrado en nuestro pais. De esta manera. existe la posibilidad de tener en Colombia especies con hábitos silvestres como: Alberprosenia malheiroi. Belminus laportei y Cavernicola lenti, preentes todas ellas en los departamentos amazónicos; Triatoma nigromaculata en la Cordillera Oriental y con hábitos intradomiciliarios; Panstrongylus chinai con posibilidad de encontrarse en hábitats selváticos o en las viviendas de los colonos de la Amazonia debido a su atracción por la luz y Alberprosenia goyovargasien hábitats silvestres de la frontera con Venezuela. Se resalta la importancia de la vigilancia entomológica a nivel nacional como estrategia para reforzar los estudios de triatominos silvestres en Colombia.

El desequilibrio de importancia entre las lenguas oficiales de Bolivia ¿ Por qué existen lenguas que son más oficiales que otras?

DEFF Research Database (Denmark)

Cancino, Rita

EL DESEQUILIBRIO DE IMPORTANCIA ENTRE LAS LENGUAS OFICIALES DE BOLIVIA ¿ POR QUÉ EXISTEN LENGUAS QUE SON MÁS OFICIALES QUE OTRAS? Con la Constitución de Bolivia muchas lenguas originarias fueron declaradas oficiales y levantadas a un nivel de lengua oficial en paridad con el español. En el Artículo...... 5 de la Constitución boliviana, la Política del Estado reconoce oficialmente a 36 idiomas como lenguas oficiales. Este reconocimiento formó parte de un proceso de descolonización, devolviendo de esta manera el orgullo de las lenguas y culturas a los pueblos originarios de Bolivia. En 2012, se...... de Bolivia”. La pregunta es si esta política lingüística en realidad confiere a todas las lenguas oficiales el mismo peso, influencia e importancia o hay algunas menos poderosas. Palabras clave: Lenguas oficiales, política lingüística, lenguas originarias, bilingüismo, diglosia....

Los Humedales de la Quebrada Estero en San Ramón, Costa Rica: importancia y estado actual.

OpenAIRE

Rodríguez-Arias, Cindy Elena; Silva Benavides, Ana Margarita

2017-01-01

Los humedales de la microcuenca alta de la Quebrada Estero, en San Ramón, Costa Rica, son considerados una prioridad de conservación por su representatividad y ubicación que los hace únicos en su tipo. Por eso se planteó el objetivo de conocer su importancia y estado actual para que esta información sirva de base para su recuperación y conservación. Se llevó a cabo la identificación de los servicios ecosistémicos y de las amenazas e impactos que tienen las actividades humanas en ellos mediant...

FUNCIONES E IMPORTANCIA ECONÓMICA DEL RECURSO CHAPULIXTLE (DODONAEA VISCOSA) EN UN EJIDO DEL SUBTRÓPICO MEXICANO

OpenAIRE

José Isabel Juan Pérez

2013-01-01

El chapulixtle (Dodonaea viscosa) es una planta cosmopolita. Para demostrar la importancia económica de esta planta, se realizó una investigación de campo en un Ejido del Subtrópico Mexicano, durante el período 2010 - 2012. Fue explorado el hábitat de la planta y su utilización por parte de las familias campesinas. La investigación se sustentó en la Geografía Ambiental (Bocco, 2007) y la Ecología Cultural (Steward, 1955), complementándose con la aplicación de un cuestionario al 100% de las f...

Reflexiones sobre la importancia de la Crítica de Lucas

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Mauricio Sánchez Puerta

2005-04-01

Full Text Available La crítica de Lucas sostiene que, bajo la hipótesis de expectativas racionales, los parámetros estimados a partir de un modelo econométrico no se mantendrían. La ocurrencia de cambios de política llevaría a los agentes a modificar sus comportamientos, a fin de adecuarse a la nueva realidad. En consecuencia, los modelos econométricos no podrían utilizarse para fines de formulación de políticas económicas. La crítica de Lucas desafió rigurosamente el modo en que el modelado econométrico se utilizaba tradicionalmente como instrumento para la evaluación de políticas económicas y la forma en que se consideraba la política económica. Aunque la importancia empírica de la crítica sigue siendo motivo de debate, ella contribuyó a la imposición de nuevos patrones en el modelado de la interacción entre las reglas de política y las respuestas de los agentes privados.

Importancia agroecológica del coyul (Acrocomia mexicana Karw. ex Mart.

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Blanca C. Ramírez Hernández

2013-01-01

Full Text Available Acrocomia mexicana Karw. ex Mart. es una especie que se extiende desde el Pacífico mexicano hasta Centro y Sudamérica. El fruto (coyul es apreciado desde la época prehispánica, sin embargo, su consumo ha disminuido frente a otros frutos nativos y así como de los introducidos con mayor aceptación en el mercado. Se realizó un estudio en San Blas, Nayarit, México, en el que se llevó a cabo la caracterización de un agroecosistema típico donde se explotan poblaciones silvestres y cultivadas de coyul de forma tradicional y se resaltó la importancia económica, ecológica y cultural de la especie. Asimismo, se realizó la caracterización fisicoquímica del fruto; la pulpa y la semilla son fuente principalmente de grasas. De esta especie se pueden obtener subproductos tales como aceites comestibles, alimento para ganado, artesanías, entre otros; igualmente se exponen alternativas de uso llevadas a cabo por otras regiones y países que puedan conducir a conservar espacios ecológicos y culturales.

Importancia clínica de las Chlamydias

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Digna Llorente Molina

Full Text Available Introducción: las infecciones por Chlamydia han alcanzado alta incidencia en el mundo. Constituyen importantes patógenos para los animales y el hombre. En la especie humana pueden ocasionar múltiples infecciones en diferentes órganos y sistemas de órganos. Objetivo: resumir los aspectos más novedosos relacionados con las Chlamydias en cuanto a sus características y formas de evitarla. Métodos: se realizó una revisión bibliográfica sobre la importancia clínica de las Chlamydias en la especie humana y su elevada incidencia. Se consultó la base de datos Medline disponible en INFOMED, de donde se extrajeron referencias bibliográficas entre los años 1995 y 2011, acerca de algunos aspectos etiológicos, clínicos, diagnósticos y terapéuticos de acuerdo a los últimos apuntes más relevantes en la literatura médica sobre Chlamydias y su relación con el hombre. Resultados: la Chlamydia Trachomatis en particular responsable del tracoma, primera causa de ceguera prevenible, provoca un impacto deletéreo en la salud reproductiva, produciendo entidades como abortos espontáneos, rotura prematura de membranas, restricción del crecimiento intrauterino, endometritis, conjuntivitis y neumonía del recién nacido. Es responsable además de Linfogranuloma Venéreo, Uretritis no Gonocóccica, Síndrome de Reiter, Enfermedad Inflamatoria Pélvica, Síndrome de Fitz Hugh Curtis, Embarazo Ectópico Crónico, Dolor Pélvico Crónico y más recientemente Carcinoma Cervical, entre otras. Conclusiones: partiendo de la base del impacto social y económico que tiene la infección por Chlamydias en el mundo y en nuestro país, pudimos resumir los aspectos más novedosos en cuanto a los tipos, infecciones que causan y sus características, diagnóstico, terapéutica y medidas generales para evitarlas o reducir su impacto negativo en la sociedad.

Parametri za procena na kvalitetot na polietilenska i na polipropilenska ambalaza i na gumeni zatvoraci nameneti za farmacevtski preparati

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Liljana Ugrinova

2002-03-01

Full Text Available Napraven e pregled na parametrite za procena na kvalitetot na polietilenska i na polipropilenska ambalaza i na gumeni zatvoraci nameneti za farmacevtski preparati. Za procena na kvalitetot na ispituvaniot materijal bea izvrseni fizicki, hemiski i bioloski ispituvanja spored postapkite dadeni vo Ph. Eur., DIN i spored DIN ISO standardite. Baranjata za kvalitet na ovoj vid ambalaza propisani spored Ph. Eur., DIN i DIN ISO standardite se razlikuvaat vo odnos na predvidenite parametri za fizicki, za hemiski i za bioloski ispituvanja. Isto taka, propisani se i razlicni granici na dozvoleno otstapuvanje na oddelni parametri.

Study of heat and salt transport processes in the Espinheiro Channel (Ria de Aveiro)

Science.gov (United States)

Vaz, Nuno Alexandre Firmino

O principal objectivo deste trabalho consistiu no estudo da dinâmica termohalina do Canal do Espinheiro em funcao de dois forcamentos principais: mare e caudal fluvial, usando duas abordagens distintas: trabalho experimental e modelacao numerica. A propagacao da mare e o caudal fluvial do Rio Vouga sao determinantes no estabelecimento da estrutura horizontal da salinidade ao longo do canal. A estrutura termica horizontal ao longo do canal e, em grande parte, determinada pela variacao sazonal da temperatura da agua do Rio Vouga, bem como, pela variacao sazonal das condicoes meteorologicas devido a reduzida profundidade. Foi observada a formacao de fortes gradientes de salinidade (relacionados com a formacao de frentes estuarinas) numa regiao a cerca de 7-8 km da embocadura do canal, observando-se a sua migracao numa regiao de aproximadamente 1 km, dependendo do regime de mare. O balanco entre o transporte de sal de natureza advectiva e difusiva foi calculado, revelando que junto a embocadura os processos fisicos que mais contribuem para o transporte de sal sao a circulacao residual e o aprisionamento da agua em canais secundarios. Junto a foz do Rio Vouga os termos devidos a descarga fluvial e a circulacao gravitacional dominam o transporte de sal. Foi calibrado e validado um modelo numerico (Mohid, em modo 2D e 3D), sendo posteriormente utilizado para estudar a hidrologia do canal. Foi concedida particular atencao ao estudo da hidrologia em condicoes extremas de caudal fluvial e de mare. Os resultados da modelacao numerica permitiram numa primeira fase avaliar o bom desempenho do Mohid na reproducao dos escoamentos barotropicos na Ria de Aveiro, bem como na evolucao temporal das propriedades termohalinas da agua. Sob condicoes de caudal fluvial reduzido, a dinâmica do canal e essencialmente dominada pela mare. Com o aumento do caudal fluvial, a influencia da agua doce estende-se para jusante, estratificando a coluna de agua. As simulacoes 3D do Canal do

Climaterio y menopausia: importancia de su atención en el nivel primario

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Miguel Lugones Botell

1997-10-01

Full Text Available Se realiza una revisión relacionada con el climaterio y la menopausia donde se relacionan sus bases anatomofisiológicas con los diversos aspectos biológicos, psicosociales, sexuales y con las enfermedades crónicas no transmisibles y el cáncer ginecológico, en la que se resalta la necesidad de una atención diferenciada y especializada, así como integral, de estas mujeres, por la importancia que tiene mejorar la calidad y el estilo de vida para hacer prevención y promoción de salud.A review concerning climateric and menopause is made and their anatomophysiological bases are related to the different biological psychosocial and sexual aspect and to non-communicable chronic disease and gynecological cancer. it is stressed the need of giving these women a diferentiated, specialized and com0prenhensive attention so as to improve their quality of life and their life style and to prevent diseases and promote health.

Importancia del conteo de células somáticas en la calidad de la leche

OpenAIRE

Hernández Reyes, Juan Manuel; Bedolla Cedeño, José Luís Carlos

2008-01-01

Este trabajo es una revisión sobre la importancia de las células somáticas en la calidad de la leche. Las células somáticas son, entre otras, células blancas propias del organismo que le sirven como defensa a la glándula mamaria de la vaca contra organismos patógenos. La determinación del contenido de células somáticas de la leche del tanque, o de los cuartos de la glándula mamaria de las vacas, es el medio auxiliar de diagnóstico más importante para juzgar el estado de salud de la ubre de un...

Osteomielitis: Criterios actuales e importancia para el Estomatólogo

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Elena Morán López

2001-04-01

Full Text Available Entre las múltiples afecciones que se presentan en el complejo bucofacial se encuentra la osteomielitis, una enfermedad ósea poco frecuente, que con el advenimiento de los antibióticos ha dejado de ser un problema de salud para muchos países del mundo. Dada la importancia que tiene su conocimiento para el estomatólogo, se recopilan criterios actuales sobre esta entidad en lo referente a la etiopatogenia, manifestaciones clínicas, diagnóstico y tratamiento, especialmente cuando afecta al maxilar o a la mandíbula. Tomando como base algunas consideraciones generales, y abarcando varios elementos, se exponen las características macroscópicas y microscópicas de las lesiones causadas por esta enfermedad.Among the various affections of the orofacial complex is osteomyelitis, a rare bone disease that, with the introduction of antibiotics, has cesed to be a health problem in many countries. Given the importante of the detection of this disease by the dentist, present criteria on this entity as to etiopathogenecity, clinical manifestations, diagnosis and treatment are collected, specially when the maxilla or the jaw is affected. Taking some general considerations and a number of elements as a basis, some macroscopic and microscopic characteristics of the lesions caused by this disease were set forth in this paper.

La importancia de los clusters para la competitividad de las PYME en una economía global

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Josep Capó-Vicedo

2007-05-01

Full Text Available En este trabajo se analiza la importancia de los clusters para las Pequeñas y Medianas Empresas (PYME, en su camino hacia economías cada vez más globalizadas y basadas en el conocimiento. Para ello se estudia la influencia que tiene la globalización sobre las economías locales, así como la importancia de la concentración geográfica de las empresas para aumentar su competitividad. Entre las conclusiones obtenidas destaca el hecho de que en estas concentraciones se pueden establecer verdaderas comunidades de conocimiento, en las que éste se genere e intercambie, al mismo tiempo que se potencia la innovación, con lo que se consigue aumentar su ventaja competitiva. Finalmente, se estudia brevemente el caso del Cluster Textil Valenciano (España, validando lo visto en la parte teórica del artículoIn this work the importance of clusters for the particular case of SMEs is analyzed, in its road toward knowledge-based and globalize economies. In short the influence that globalization has about the local economies is studied, as well as the importance of the geographical concentration of the companies in order to increase their competitiveness. Among the obtained conclusions it highlights the fact that in these concentrations true communities of knowledge can settle down, where new knowledge is generated and exchanged, at the same time that innovation is empowered, and their competitive advantage is increased. Finally, the particular case of the Valencia Textile Cluster (Spain is studied, in order to validate the theoretical part of the article

Importancia de la donación de células madre en pacientes con anemia de Fanconi

OpenAIRE

Sánchez Martín, Lucía

2014-01-01

La importancia de la donación tanto de médula ósea como de sangre del cordón umbilical se debe a que contiene unas células denominadas células madre. Estas células pueden ser de dos tipos: embrionarias, que se obtienen de la sangre del cordón umbilical, y maduras, que se pueden obtener de la médula ósea y de sangre periférica. La capacidad que tienen estas células y las hace tan especiales es que pueden dividirse formando nuevas células madre, o formar otras células más especializa...

Načrtovan porod na domu

OpenAIRE

Todorović, Tamara; Takač, Iztok

2017-01-01

Izhodišča: Porod na domu je sicer star toliko kot človeštvo, pa vendar v veliki večini srednje in visoko razvitih držav prevladuje mnenje, da so zaradi nepredvidljivosti zapletov porodnišnice najbolj varno okolje za rojevanje. Kljub temu obstaja peščica držav, v katerih je porod na domu integriran v sistem zdravstvenega varstva (npr. Nizozemska, Velika Britanija, Kanada). Pri porodih na domu ločimo nenačrtovane in načrtovane porode na domu, slednje pa lahko nadalje razdelimo še na porode s sp...

Las aguas subterráneas transfronterizas México-Estados Unidos: importancia e invisibilidad dentro del contexto del TLCAN

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Gonzalo HATCH KURI

2015-04-01

Full Text Available Este artículo identifica la importancia del agua subterránea transfronteriza México-Estados Unidos, en relación con el vacío jurídico que predomina en su regulación en las diferentes escalas que intervienen en el uso, manejo y extracción de la misma y el significado de la escasez hídrica en la configuración del discurso hegemónico de seguridad nacional en el panorama neoliberal de integración regional del Tratado de Libre Comercio de América del Norte (TLCAN.

EL CAPITAL DE TRABAJO NETO Y EL VALOR EN LAS EMPRESAS LA IMPORTANCIA DE LA RECOMPOSICIÓN DEL CAPITAL DE TRABAJO NETO EN LAS EMPRESAS QUE ATRAVIESAN O HAN ATRAVESADO CRÍSIS FINANCIERAS

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María Marcela Rizzo

2007-07-01

Full Text Available La importancia del capital de trabajo en la generación de valor de las empresas se pone en evidencia a partir de la ausencia del mismo. En este trabajo vamos a exponer qué ocurre en las empresas cuando no hay el suficiente capital de trabajo y la importancia que reviste su recompo-sición. Veremos, en los tres ejemplos presentados, cómo a partir de la recomposición del capital de trabajo de se comienza o se mejora la actividad de las empresas y, por ende, la generación de valor.

La anticipación defensiva en los deportes de equipo: Un estudio de la importancia otorgada a sus variables

OpenAIRE

Guzmán, José Francisco; García Ferriol, Ángel

2002-01-01

El presente estudio pretendió identificar las principales variables que inciden sobre el éxito en la anticipación defensiva y realizar una jerarquización de su nivel de importancia a partir de las opiniones de los propios practicantes del deporte. El estudio se realizó con una muestra de 181 estudiantes de Educación Secundaria y Universidad, todos ellos con experiencia deportiva extraescolar, de edades comprendidas entre 16 y 20 años, a los cuales se les administró un cuestionario de 10 ítems...

El mecanismo de muerte celular programada y su importancia en el proceso de maduración de la carne bovina

Directory of Open Access Journals (Sweden)

Janeth Ortega Torres

2012-06-01

Full Text Available El objetivo de este artículo es presentar el mecanismo de muerte celular programada y las evidencias que apoyan su relación con el proceso de maduración de la carne bovina. La terneza de la carne bovina es quizá una de las características más importantes para los consumidores, pues hace de la carne un producto deseable en los mercados mundiales e influye en su precio y calidad. Estas características dependen de factores genéticos, nutricionales y ambientales. Aunque en Colombia aún no existe la cultura de la trazabilidad de los productos cárnicos en los supermercados, se prevé que en un futuro cercano aumente el número de consumidores en América Latina y que ellos tendrán también la posibilidad de exigir las mejores carnes. Descifrar los factores bioquímicos y moleculares que influyen en la maduración de la carne bovina es una tarea amplia que está en sus primeras etapas. Se han descifrado algunas vías implicadas, como la de la calpaína-calpastatina, la proteosómica y la de las catepsinas, proteínas que han sido reconocidas como de influencia positiva en el proceso de degradación de la fibra muscular durante su proceso de maduración. La conversión del músculo en carne es un proceso que comienza una vez el animal ha sido sacrificado y, por lo tanto, está asociado a los procesos de necrosis y muerte celular. En los últimos años muchos estudios se han orientado hacia la importancia y el aporte del mecanismo de muerte celular programada o apoptosis sobre la terneza de la carne.

HIDROGENACIÓN DE ACROLEÍNA Y CROTONALDEHÍDO SOBRE CATALIZADORES DE Ir SOPORTADO

Directory of Open Access Journals (Sweden)

HUGO ROJAS

2009-01-01

insaturados, acroleína y crotonaldehído, para la obtención de sus alcoholes insaturados alcohol alílico y crotílico respectivamente, cuya utilidad en la industria de la química fina es de amplio reconocimiento. Los aldehídos objeto de esta investigación representan un alto riesgo ambiental, por lo que la investigación presentada en este trabajo resulta de gran importancia en ese campo. En general los resultados obtenidos muestran que factores como temperatura de reducción y contenido de TiO2 en los catalizadores son determinantes en el comportamiento catalítico; análisis de caracterización permitieron establecer que en los catalizadores reducidos a alta temperatura se presenta el efecto de interacción fuerte metal soporte, conocido por su símbolo SMSI, lo que favorece la conversión, actividad inicial y TOF. De igual manera los catalizadores evaluados son altamente selectivos hacia los alcoholes insaturados que representan los productos de interés en este estudio.

Las enfermedades infecciosas y su importancia en el sector avícola

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Javier Andrés Jaimes Olaya

2010-12-01

Full Text Available Dentro del contexto de un país cuyas mejores capacidades se encuentran en el sector agropecuario, la industria avícola se ha convertido en uno de los sectores más promisorios y de mayor crecimiento en Colombia. Por esta razón, actualmente se vienen implementando programas para el mejoramiento de la calidad de los productos avícolas, con el objetivo no solo de mantener el crecimiento de la industria,sino de poder expandir las fronteras de exportación. Sin embargo, la avicultura enfrenta un gran reto encuanto a su producción, debido a que las enfermedades infecciosas que afectan a las aves continúan siendo una problemática importante del sector, aun por encima de la alimentación y la genética. En este artículo se presentan elementos de relevancia referentes a la industria avícola, así como en relación con las enfermedades de control oficial y algunas de las enfermedades infecciosas que más la aquejan, enfatizando en la importancia de la intervención en el manejo y control de dichas enfermedades.

Repositorio de objetos de aprendizaje: importancia de su uso en la Universidad de Oriente

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Ing. Alfredo Díaz-Calzada

2015-10-01

Full Text Available La creciente producción de materiales educativos en formatodigital ha promovido la aparición en estos últimos años, de repositorios que concentran valiosos recursos para docentes, estudiantes e instituciones educativas, en general.En la actualidad los proyectos de Repositorios de Objetos de Aprendizaje (ROA han ido en aumento, es por esto que este trabajo aborda el tema de los ROA y su uso en la Universidad de Oriente, para su desarrollo se hace una revisión de los conceptos básicos de los Objetos de Aprendizaje, ya que no se podría hablar de los ROA sin antes mencionar estos tipos de objetos y después se plantea el porqué del uso de este en la Universidad de Oriente y la estrategia a seguir para su implementación, además de la importancia que tiene la utilización de estos repositorios en la enseñanza-aprendizaje.

APROXIMACIÓN AL CONCEPTO DE GOBERNANZA EN COLOMBIA Y ALGUNOS APUNTES SOBRE SU IMPORTANCIA EN EL DERECHO AMBIENTAL

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Erika Castro Buitrago

2011-12-01

Full Text Available Este artículo presenta un breve estudio sobre la recepción del concepto de Gobernanza en Colombia, su uso en la política ambiental y la investigación interna que existe en esta materia. En especial, el artículo llama la atención sobre la necesidad de estudiar la influencia del término en el ámbito del derecho administrativo ambiental, a partir de la importancia que otros ordenamientos jurídicos le han otorgado. En el caso europeo, la gobernanza se entiende como el modelo ideal de gobernación para gestionar los asuntos ambientales

Diagnóstico de parásitos gastrointestinales en bovinos y su importancia en la productividad de los sistemas ganaderos.

OpenAIRE

Castillo O., Mayela; Hernández, Javier A.; Betancourt, Arquímedes; Suniaga Q., José

2007-01-01

Editorial. Suniaga Q., José La codorniz fuente proteica para consumo humano. Díaz Cuellar, Doraida R. y González, Diomary Diagnóstico de parásitos gastrointestinales en bovinos y su importancia en la productividad de los sistemas ganaderos. Castillo O., Mayela; Hernández, Javier A.; Betancourt, Arquímedes y Suniaga Q., José Nutrición vegetal (II). Moyeja Santana, Juan de Jesús Nutrición vegetal (III). Moyeja Santana, Juan de Jesús Plagas chupadoras de las cítrica...

La importancia de la cosmética termal para los balnearios y el turismo termal: el caso de la Comunidad Autónoma de Galicia - España

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Marcel Rodrigo Henn Bonfada

2011-01-01

Full Text Available Este trabajo engloba el turismo termal dentro del concepto del turismo de salud y la cosmética termal como un nuevo negocio para los balnearios españoles. El objetivo es identificar la importancia de la cosmética termal para los balnearios gallegos y de los aspectos del marketing relacionados a ella en estos centros. La metodología está basada en una investigación empírica, descriptiva y se adoptó un enfoque cualitativo. Como instrumento de recogida de datos fue hecho un cuestionario estructurado, utilizándose la técnica de la entrevista en profundidad con preguntas abiertas y cerradas. Los resultados fueron que la cosmética termal tiene gran importancia en aspectos intangibles para los balnearios gallegos y fueron descritos estos aspectos además de identificar otras importantes informaciones relacionadas al marketing.

La importancia y el papel del nutricionista en la atención primaria en Vitoria de Santo Antão, Pernambuco, Brasil.

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Karla Adriana Oliveira da COSTA

2011-12-01

Full Text Available Brasil está experimentando muchos cambios, entre ellos los de naturaleza poblacional, epidemiológica y nutricional, siendo este último caracterizado por la disminución de la desnutrición y el aumento de sobrepeso / obesidad así como de la hipertensión y la diabetes. Siendo la alimentación y la nutrición, al mismo tiempo factor protector y de riesgo para el desarrollo de tales condiciones, se considera que la inclusión del nutricionista en la atención primaria en salud (APS puede tener un impacto importante. El objetivo del estudio fue determinar la importancia y el papel del nutricionista en la APS. Fue realizada una investigación cuali-cuantitativa. En este artículo, se muestra el uso de técnicas de la hermenéutica dialéctica y el Discurso del Sujeto Colectivo (DSC de los profesionales actuando en la Estrategia de Salud de la Familia (ESF en Vitoria de Santo Antão, Pernambuco, Brasil, entre 2010 y 2011, se examinó la importancia y el papel del nutricionista en la APS. A partir del análisis del perfil epidemiológico se constata la importancia de las enfermedades crónicodegenerativas en consonancia con la transición nutricional. El DSC nos permitió concluir que el profesional de la nutrición es el más adecuado para hacer frente a este escenario adverso, y las acciones de la nutrición / alimentación deben ser desarrolladas por todos los trabajadores de la salud. Los entrevistados destacaron la necesidad de un especialista en nutrición como parte de la ESF, actuando en el equipo nuclear, sin el mínimo perjuicio para su inserción en el Núcleo de Apoyo a Salud de la Familia (NASF. Es urgente organizar y darle calidad a la atención nutricional en la APS, ya que la actual inserción del nutricionista está lejos Revista Tempus Actas de Saúde Coletiva 69 de lo necesario para hacer frente a la realidad epidemiológica en Brasil.

Enteropatógenos de importancia en salud pública

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Maribel Riveros

Full Text Available La diarrea continúa siendo la tercera causa de muerte en niños menores de 5 años, pese a los avances recientes en el manejo y prevención de esta enfermedad. Es causada por múltiples patógenos, sin embargo, la prevalencia de cada uno varía según el grupo de edad, la zona geográfica y el escenario donde se registran los casos (comunitario vs hospitalario. Los patógenos de mayor relevancia en salud pública son aquellos asociados con mayor carga de enfermedad, severidad, complicaciones y mortalidad. En nuestro medio, el norovirus, Campylobacter y las E. coli diarrogénicas, son los patógenos más prevalentes a nivel comunitario en niños. En este artículo se revisa la epidemiología local y las potenciales áreas de desarrollo en cinco patógenos seleccionados: rotavirus, norovirus, E. coli productora de toxina Shiga (STEC, Shigella y Salmonella. De estos, el rotavirus es el más importante en la población pediátrica y el principal responsable de la mortalidad infantil por diarrea. La introducción de la vacunación contra rotavirus en nuestro país tendrá un importante impacto en la carga de enfermedad y la mortalidad por diarrea. Sin embargo, se requieren estudios de vigilancia para determinar el impacto de la vacunación y el cambio en la epidemiología de la diarrea en el Perú luego de la introducción de nuevas vacunas, así como la vigilancia de las tasas de resistencia antibiótica para las bacterias de importancia clínica.

Importancia dada a la cultura corporativa por los responsables del área de talento humano, en empresas colombianas medianas y grandes

OpenAIRE

Olga Lucía Anzola Morales

2010-01-01

El proyecto de investigación cuyos resultados parciales se presentan en este artículo, indaga por las similitudes y diferencias encontradas entre las propuestas de estudio que enfatizan en la importancia de la cultura organizacional como un elemento que permite a las empresas establecer rasgos de diferenciación en el mercado y elevar sus niveles competitivos, con las apreciaciones y las prácticas de 50 encargados del área de talento humano de empresas colombianas medianas y grandes. La invest...

Variación estacional de la composición proximal en tres especies de importancia comercial del Golfo de Nicoya, Puntarenas, Costa Rica

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Cristian Fonseca Rodríguez

2013-03-01

Full Text Available La información disponible sobre la composición química de algunos recursos pesqueros que se capturan en el Golfo de Nicoya es muy limitada. Por tal razón se determinaron los niveles de los componentes proximales de las partes comestibles (fresco de tres especies de importancia comercial. Las muestras fueron adquiridas en el Mercado de Puntarenas entre febrero 2009 y enero 2001 durante la temporada de pesca. Los análisis de la composición proximal se determinaron según la metodología de AOAC. Los resultados indicaron que el contenido de humedad varió entre 74.6-80.6g/100g en robalo (Centropomus unionesis, 76.9-80.0g/100g en camarón (Trachypenaeus byrdi y 77.9-89.5g/100g en almeja verde (Poymesoda radiata. Después de la humedad la fracción química más abundante fue la proteína presentando los valores más altos en diciembre para el robalo y febrero para el camarón y la almeja verde. Las mayores fluctuaciones en el contenido de lípidos se presentaron en el robalo, variando desde 0.7g/100g hasta 5.6g/100g. Los valores más altos en esta fracción fueron encontrados en julio, febrero y abril en camarones, almeja y robalo respectivamente. Se concluye que la especie de pescado y camarón estudiados son una buena alternativa para el consumo humano por ser una fuente importante de proteínas y por su bajo contenido en lípidos.

Lesión de paladar duro por uso crónico de cocaína. Reporte de un caso

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José Luis D’Addino

2014-09-01

Full Text Available El objetivo de este trabajo fue presentar una lesión inusual de gran tamaño comprometiendo paladar duro. Se describe su diagnóstico, manejo terapéutico y evolución. El paciente de raza blanca de 37 años, desde hace 12 meses presentaba lesión ulcerada con perforación de paladar duro. Dentro de los antecedentes personales se resalta el uso de cocaína desde hace 20 años, tabaquista desde hace 23 años. Como antecedentes familiares de importancia cabe citarse 2 casos de Hipertermia Maligna en familiares consanguíneos operados anteriormente. La biopsia de la lesión fue lesión benigna. Se intervino quirúrgicamente efectuándose un colgajo tipo Randal para el cierre del defecto y Rintala para la cobertura de la cara nasal del orificio. Se reforzó con malla de colágeno entre los dos colgajos. El último control a los 6 meses de seguimiento, mostraba buena evolución post quirúrgica aunque recayó en el consumo de cocaína y no regresó a la consulta. En conclusión, el uso crónico de cocaína suele destruir el tabique nasal y el paladar. La reparación resulta un desafió por lo dificultoso de la obtención de tejidos sumado a la escasa adhesión de los enfermos al abandono de la droga.

Importancia y propiedades físico química de la Rosa mosqueta (R. canina, R. rubiginosa: una revisión

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T. Espinoza

2016-01-01

Full Text Available Los consumidores cada día exigen productos en sus dietas que no solo aporten los nutrientes requeridos para una vida sana, sino que además son de preferencia aquellos que puedan complementar con propiedades benéficas para la salud. En las últimas décadas se ha reconocido a la Rosa mosqueta, la Rosa canina y a la Rosa rubiginosa, como frutos que contienen muchas propiedades nutracéuticas. El presente trabajo hace una revisión de los artículos de investigación realizados a la Rosa mosqueta desde un punto de vista de su importancia de su consumo y sus beneficios para la salud; describiendo las características químicas, físicas y bioquímicas tales como el contenido de componentes fenólicos, ácidos grasos, ácido linoleico, minerales; y de otros compuestos importantes también desde el punto de vista industrial, tales como el contenido de antioxidantes, pigmentos, entre otros. De acuerdo a los antecedentes recopilados, la Rosa mosqueta es una fuente de micronutrientes incluyendo la vitamina c y el licopeno, entregando además un buen aporte nutricional; por lo anterior debe ser considerado como un alimento funcional. Aun siendo una especie que crece en estado salvaje, sobre suelos forestales; siendo un frutal menor y una planta medicinal su importancia en el consumo masivo debe ser considerada.

IMPORTANCIA E IMPACTO SOCIAL DE LA TUBERCULOSIS EN LOS NIÑOS

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Magnolia Arango Loboguerrero

2015-09-01

Full Text Available

Sin importar lo significativa que es la existencia de la tuberculosis (TB infantil, esta ha sido olvidada y subestimada hasta ahora y es de importancia secundaria en los programas de salud pública y en la clínica. Por inmadurez inmunológica y fisiopatogenia, hay expresiones clínicas inespecíficas, diversas y muy variables; presenta además dificultades en el diagnóstico por ser causada por poblaciones bacilares escasas, es decir es paucibacilar y difícil de detectar en las baciloscopias; las muestras son dispendiosas de recolectar debido a la limitación normal que tiene el niño para expectorar hasta los 4 a 5 años, lo cual hace que exista un bajo rendimiento de la positividad de los estudios.

IMPORTANCE AND SOCIAL IMPACT OF TUBERCULOSIS IN CHILDREN

ABSTRACT

No matter how significant children tuberculosis (TB might be, it is a forgotten condition, so far underestimated, of secondary importance in public health programs and from its clinical aspect. Due to immunologic immaturity and physiopathogeny, there are non specific different and very variable manifestations, showing diagnostic difficulties for sputum being paucibacillar, germs not readiliy found in bacilloscopies; sputum samples are hard to collect, since children younger than 5 have trouble in coughing up, so bacilloscopies are seldom positive.

Keywords: Tuberculosis, Koch bacillus, children pneumopathies

Na+-stimulated ATPase of alkaliphilic halotolerant cyanobacterium Aphanothece halophytica translocates Na+ into proteoliposomes via Na+ uniport mechanism

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Soontharapirakkul Kanteera

2010-08-01

Full Text Available Abstract Background When cells are exposed to high salinity conditions, they develop a mechanism to extrude excess Na+ from cells to maintain the cytoplasmic Na+ concentration. Until now, the ATPase involved in Na+ transport in cyanobacteria has not been characterized. Here, the characterization of ATPase and its role in Na+ transport of alkaliphilic halotolerant Aphanothece halophytica were investigated to understand the survival mechanism of A. halophytica under high salinity conditions. Results The purified enzyme catalyzed the hydrolysis of ATP in the presence of Na+ but not K+, Li+ and Ca2+. The apparent Km values for Na+ and ATP were 2.0 and 1.2 mM, respectively. The enzyme is likely the F1F0-ATPase based on the usual subunit pattern and the protection against N,N'-dicyclohexylcarbodiimide inhibition of ATPase activity by Na+ in a pH-dependent manner. Proteoliposomes reconstituted with the purified enzyme could take up Na+ upon the addition of ATP. The apparent Km values for this uptake were 3.3 and 0.5 mM for Na+ and ATP, respectively. The mechanism of Na+ transport mediated by Na+-stimulated ATPase in A. halophytica was revealed. Using acridine orange as a probe, alkalization of the lumen of proteoliposomes reconstituted with Na+-stimulated ATPase was observed upon the addition of ATP with Na+ but not with K+, Li+ and Ca2+. The Na+- and ATP-dependent alkalization of the proteoliposome lumen was stimulated by carbonyl cyanide m - chlorophenylhydrazone (CCCP but was inhibited by a permeant anion nitrate. The proteoliposomes showed both ATPase activity and ATP-dependent Na+ uptake activity. The uptake of Na+ was enhanced by CCCP and nitrate. On the other hand, both CCCP and nitrate were shown to dissipate the preformed electric potential generated by Na+-stimulated ATPase of the proteoliposomes. Conclusion The data demonstrate that Na+-stimulated ATPase from A. halophytica, a likely member of F-type ATPase, functions as an electrogenic Na

Polarization dependence of Na* + Na* associative ionization revisited

NARCIS (Netherlands)

Meijer, H.A.J.; Meulen, H.P. v.d.; Morgenstern, R.; Hertel, I.V.; Meyer, E.; Witte, R.

1986-01-01

The dependence of the associative ionization process Na 3 2P3/2 + Na 3 2P3/2 → Na2+ + e- on the polarization of the laser light used for Na excitation was independently investigated in Utrecht and Berlin. The purpose of this paper is to clarify discrepancies between two other earlier experimental

Pseudo-ternary phase diagram in the Na2O-Na2O2-NaOH system

International Nuclear Information System (INIS)

Saito, Jun-ichi; Tendo, Masayuki; Aoto, Kazumi

1997-10-01

Generally, the phase diagrams are always used to understand the present state of compounds at certain temperature. In order to understand the corrosion behavior of structural material for FBR by main sodium compounds (Na 2 O, Na 2 O 2 and NaOH), it is very important to comprehend the phase diagrams of their compounds. However, only Na 2 O-NaOH pseudo-binary phase diagram had been investigated previously in this system. There is no study of other pseudo-binary or ternary phase diagrams in the Na 2 O-Na 2 O 2 -NaOH system. In this study, in order to clarify the present states of their compounds at certain temperatures, the pseudo-binary and ternary phase diagrams in the Na 2 O-Na 2 O 2 -NaOH system were prepared. A series of thermal analyses with binary and ternary component system has been carried out using the differential scanning calorimetry (DSC). The liquidus temperature and ternary eutectic temperatures were confirmed by these measurements. The beneficial indications for constructing phase diagrams were obtained from these experiments. On the basis of these results, the interaction parameters between compounds which were utilized for the Thermo-Calc calculation were optimized. Thermo-Calc is one of thermodynamic calculation software. Consequently the accurate pseudo-binary and ternary phase diagrams were indicated using the optimized parameters. (author)

Extracellular Na+ levels regulate formation and activity of the NaX/alpha1-Na+/K+-ATPase complex in neuronal cells.

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Emmanuelle eBerret

2014-12-01

Full Text Available MnPO neurons play a critical role in hydromineral homeostasis regulation by acting as sensors of extracellular sodium concentration ([Na+]out. The mechanism underlying Na+-sensing involves Na+-flow through the NaX channel, directly regulated by the Na+/K+-ATPase α1-isoform which controls Na+-influx by modulating channel permeability. Together, these two partners form a complex involved in the regulation of intracellular sodium ([Na+]in. Here we aim to determine whether environmental changes in Na+ could actively modulate the NaX/Na+/K+-ATPase complex activity.We investigated the complex activity using patch-clamp recordings from rat MnPO neurons and Neuro2a cells. When the rats were fed with a high-salt-diet, or the [Na+] in the culture medium was increased, the activity of the complex was up-regulated. In contrast, drop in environmental [Na+] decreased the activity of the complex. Interestingly under hypernatremic condition, the colocalization rate and protein level of both partners were up-regulated. Under hyponatremic condition, only NaX protein expression was increased and the level of NaX/Na+/K+-ATPase remained unaltered. This unbalance between NaX and Na+/K+-ATPase pump proportion would induce a bigger portion of Na+/K+-ATPase-control-free NaX channel. Thus we suggest that hypernatremic environment increases NaX/Na+/K+-ATPase α1-isoform activity by increasing the number of both partners and their colocalization rate, whereas hyponatremic environment down-regulates complex activity via a decrease in the relative number of NaX channels controlled by the pump.

Investigación y conservación de la biodiversidad en Perú: importancia del uso de técnicas modernas y procedimientos administrativos eficientes

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Rudolf von May

2013-06-01

Full Text Available Este comentario resalta la importancia que el análisis de secuencias de ADN tiene en los estudios de biodi-versidad y la necesidad de mejorar los procedimientos administrativos concernientes a las investigaciones de biodiversidad en el Perú. La rápida pérdida de la biodiversidad y recursos naturales del Perú justifican la urgencia de apoyar aquellas investigaciones que ayuden a identificar, describir y caracterizar a la biodiversidad en la brevedad posible, para que se puedan tomar las debidas medidas de conservación y mitigación. Enfatizamos la importancia del uso de técnicas modernas dentro del modelo de estudio de la taxonomía integradora, incluyendo el estudio de los procesos evolutivos asociados a áreas con mayor diversidad y endemismo y los efectos del cambio climático sobre la biodiversidad peruana. Asimismo, es esencial que las entidades gubernamentales encargadas de evaluar los planes, solicitudes y requisitos asociados a las investigaciones de la biodiversidad del Perú reconozcan y apoyen el enfoque de la taxonomía integradora. El uso de técnicas modernas dentro del modelo de la taxonomía integradora, junto a procedimientos administrativos eficientes, puede convertirse en la mejor herramienta para proteger la biodiversidad peruana.

Estudio psicométrico y predicción de la importancia de la educación física a partir de las orientaciones de meta ("Perception of Success Questionnaire - POSQ"

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Antonio Granero-Gallegos

2014-01-01

Full Text Available El objetivo de esta investigación fue doble: (a analizar las propiedades psicométricas del Perception of Success Questionnaire (POSQ adaptado a la Educación Física (EF; y (b analizar la predicción de la importancia y utilidad concedida a la EF a partir de las orientaciones de meta, percepción de competencia y satisfacción del alumnado. El cuestionario estuvo compuesto por los siguientes instrumentos: POSQ, Escala de Necesidades Psicológicas Básicas en el Ejercicio, Satisfacción con la EF e Importancia de la EF. Se administró a 846 estudiantes españoles de secundaria de 12 a 19 años. La estructura del POSQ se analizó mediante procedimientos confirmatorios y mostró una consistencia interna fiable y una estructura factorial estable (apoyando el modelo teórico hipotetizado: orientación al ego y a la tarea. Así, se considera un instrumento válido para medir la orientación de meta disposicional en EF. Para la predicción de la importancia de la EF a partir de las orientaciones de meta, competencia y satisfacción, se halló un modelo de ecuaciones estructurales que confirmó que la orientación a la tarea es la que más influye en la percepción de competencia y ésta en la satisfacción/diversión, lo que predice que el alumnado considere más importante y útil la asignatura.

A Study of the Distribution of Sodium Cations in the Zeolites NaX, NaY and ZnNaY Using Carbon Monoxide Adsorption and 23Na NMR Techniques

Science.gov (United States)

Seidel, A.; Boddenberg, B.

1995-03-01

The zeolites NaX, NaY, Zn(55)NaY, and Zn(74)NaY were investigated by means of carbon monoxide adsorption and with static and magic angle spinning (MAS) 23Na NMR spectroscopy. The Na+ distribution between the sodalite (ß)- and supercages of the fully hydrated zeolites NaX and NaY were found to agree with XRD results. In the hydrated zinc-exchanged zeolites the Na+ ions almost exclusively populate the ß-cages. The adsorption isotherms of CO in the dehydrated zeolites were analyzed quantitatively to yield the concentrations of Na+ residing in the supercages. The measured static and MAS 23Na NMR spectra were analyzed by comparing their widths and shapes with simulated central transition patterns and yield, inter alia, the concentrations of Na+ associated with the spectrum components. Arguments are put forward that 23Na NMR of dehydrated zeolites is well suited to distinguish Na+ cations in highly symmetric environments and mobile Na+ species from others located on general positions, but further resolution is hardly feasible.

HCO3(-)-coupled Na+ influx is a major determinant of Na+ turnover and Na+/K+ pump activity in rat hepatocytes

International Nuclear Information System (INIS)

Fitz, J.G.; Lidofsky, S.D.; Weisiger, R.A.; Xie, M.H.; Cochran, M.; Grotmol, T.; Scharschmidt, B.F.

1991-01-01

Recent studies in hepatocytes indicate that Na(+)-coupled HCO3- transport contributes importantly to regulation of intracellular pH and membrane HCO3- transport. However, the direction of net coupled Na+ and HCO3- movement and the effect of HCO3- on Na+ turnover and Na+/K+ pump activity are not known. In these studies, the effect of HCO3- on Na+ influx and turnover were measured in primary rat hepatocyte cultures with 22Na+, and [Na+]i was measured in single hepatocytes using the Na(+)-sensitive fluorochrome SBFI. Na+/K+ pump activity was measured in intact perfused rat liver and hepatocyte monolayers as Na(+)-dependent or ouabain-suppressible 86Rb uptake, and was measured in single hepatocytes as the effect of transient pump inhibition by removal of extracellular K+ on membrane potential difference (PD) and [Na+]i. In hepatocyte monolayers, HCO3- increased 22Na+ entry and turnover rates by 50-65%, without measurably altering 22Na+ pool size or cell volume, and HCO3- also increased Na+/K+ pump activity by 70%. In single cells, exposure to HCO3- produced an abrupt and sustained rise in [Na+]i from approximately 8 to 12 mM. Na+/K+ pump activity assessed in single cells by PD excursions during transient K+ removal increased congruent to 2.5-fold in the presence of HCO3-, and the rise in [Na+]i produced by inhibition of the Na+/K+ pump was similarly increased congruent to 2.5-fold in the presence of HCO3-. In intact perfused rat liver, HCO3- increased both Na+/K+ pump activity and O2 consumption. These findings indicate that, in hepatocytes, net coupled Na+ and HCO3- movement is inward and represents a major determinant of Na+ influx and Na+/K+ pump activity. About half of hepatic Na+/K+ pump activity appears dedicated to recycling Na+ entering in conjunction with HCO3- to maintain [Na+]i within the physiologic range

Importancia del aprendizaje organizacional como mecanismo que favorece la consecución de los objetivos organizacionales

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Vera Ramírez, Mónica

2016-01-01

Full Text Available En el presuroso mundo globalizado de hoy, las empresas deben dar cumplimiento a exigentes normas de competitividad. Asimismo, la productividad se encuentra asociada a la adaptación e innovación que posibilite la sostenibilidad y el crecimiento dentro de un sector específico . Por eso el desarrollo organizacional ocupa un lugar clave dentro del ejercicio empresarial, pues los conocimientos y habilidades con los que cuente la empresa para enfrentar los retos del entorno constituyen la única estrategia de éxito. Este artículo tiene por objetivo destacar la importancia del aprendizaje organizacional como mecanismo que favorece la consecución de los objetivos organizacionales, desde una revisión teórica; cuando se ha entendido y cultivado este concepto puede surgir el pensamiento sistémico, quinta disciplina de Peter Senge. El fortalecimiento del talento humano en la organización es fundamental porque impacta en los resultados finales.

Importancia de los análisis serológicos, moleculares y virológicos en la vigilancia de la fiebre amarilla en Colombia, 2006-2008

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Gloria Inés Múnera

2010-09-01

Conclusión. Se observa la necesidad de seguir manteniendo y fortaleciendo los procesos de vigilancia en las regiones de mayor circulación del virus, para la captación oportuna de casos. Se recalca la importancia del diagnóstico por medio de las técnicas descritas, las cuales se pueden realizar en muestras de pacientes vivos, contrario a las pruebas histopatológicas que requieren muestras de casos fatales.

The effect of Na vapor on the Na content of chondrules

Science.gov (United States)

Lewis, R. Dean; Lofgren, Gary E.; Franzen, Hugo F.; Windom, Kenneth E.

1993-01-01

Chondrules contain higher concentrations of volatiles (Na) than expected for melt droplets in the solar nebula. Recent studies have proposed that chondrules may have formed under non-canonical nebular conditions such as in particle/gas-rich clumps. Such chondrule formation areas may have contained significant Na vapor. To test the hypothesis of whether a Na-rich vapor would minimize Na volatilization reaction rates in a chondrule analog and maintain the Na value of the melt, experiments were designed where a Na-rich vapor could be maintained around the sample. A starting material with a melting point lower that typical chondrules was required to keep the logistics of working with Na volatilization from NaCl within the realm of feasibility. The Knippa basalt, a MgO-rich alkali olivine basalt with a melting temperature of 1325 +/- 5 C and a Na2O content of 3.05 wt%, was used as the chondrule analog. Experiments were conducted in a 1 atm, gas-mixing furnace with the fO2 controlled by a CO/CO2 gas mixture and fixed at the I-W buffer curve. To determine the extent of Na loss from the sample, initial experiments were conducted at high temperatures (1300 C - 1350 C) for duration of up to 72 h without a Na-rich vapor present. Almost all (up to 98%) Na was volatilized in runs of 72 h. Subsequent trials were conducted at 1330 C for 16 h in the presence of a Na-rich vapor, supplied by a NaCl-filled crucible placed in the bottom of the furnace. Succeeding Knudsen cell weight-loss mass-spectrometry analysis of NaCl determined the P(sub Na) for these experimental conditions to be in the 10(exp -6) atm range. This value is considered high for nebula conditions but is still plausible for non-canonical environments. In these trials the Na2O content of the glass was maintained or in some cases increased; Na2O values ranged from 2.62% wt to 4.37% wt. The Na content of chondrules may be controlled by the Na vapor pressure in the chondrule formation region. Most heating events capable

Na/K pump inactivation, subsarcolemmal Na measurements, and cytoplasmic ion turnover kinetics contradict restricted Na spaces in murine cardiac myocytes.

Science.gov (United States)

Lu, Fang-Min; Hilgemann, Donald W

2017-07-03

Decades ago, it was proposed that Na transport in cardiac myocytes is modulated by large changes in cytoplasmic Na concentration within restricted subsarcolemmal spaces. Here, we probe this hypothesis for Na/K pumps by generating constitutive transsarcolemmal Na flux with the Na channel opener veratridine in whole-cell patch-clamp recordings. Using 25 mM Na in the patch pipette, pump currents decay strongly during continuous activation by extracellular K (τ, ∼2 s). In contradiction to depletion hypotheses, the decay becomes stronger when pump currents are decreased by hyperpolarization. Na channel currents are nearly unchanged by pump activity in these conditions, and conversely, continuous Na currents up to 0.5 nA in magnitude have negligible effects on pump currents. These outcomes are even more pronounced using 50 mM Li as a cytoplasmic Na congener. Thus, the Na/K pump current decay reflects mostly an inactivation mechanism that immobilizes Na/K pump charge movements, not cytoplasmic Na depletion. When channel currents are increased beyond 1 nA, models with unrestricted subsarcolemmal diffusion accurately predict current decay (τ ∼15 s) and reversal potential shifts observed for Na, Li, and K currents through Na channels opened by veratridine, as well as for Na, K, Cs, Li, and Cl currents recorded in nystatin-permeabilized myocytes. Ion concentrations in the pipette tip (i.e., access conductance) track without appreciable delay the current changes caused by sarcolemmal ion flux. Importantly, cytoplasmic mixing volumes, calculated from current decay kinetics, increase and decrease as expected with osmolarity changes (τ >30 s). Na/K pump current run-down over 20 min reflects a failure of pumps to recover from inactivation. Simulations reveal that pump inactivation coupled with Na-activated recovery enhances the rapidity and effectivity of Na homeostasis in cardiac myocytes. In conclusion, an autoregulatory mechanism enhances cardiac Na/K pump activity when

LA IMPORTANCIA DEL HIGIENISMO Y LA POTABILIZACIÓN DEL AGUA EN LA CIUDAD DE VALENCIA (1860 -1910

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José Antonio Palomero González

2016-01-01

Full Text Available El siglo XIX se caracteriza por numerosos cambios tanto a nivel social como estructural de la pobla - ción: se produce un acelerado desarrollo urbano sin planificación y carente de servicios que da lugar a una mala calidad de vida y numerosas epidemias. Estos cambios tienen como resultado un nuevo movi - miento, el Higienismo, que pretende mejorar las condiciones de vida de la población. En España, todas las reformas higiénicas se desarrollaron mediante los planes de Ensanche. Uno de los puntos clave de este pensamiento es el abastecimiento de agua potable como medio para evitar enfermedades. La ciudad de Valencia es un claro ejemplo de la importancia de este movimiento y cómo el abastecimiento de agua es un elemento clave en la mejora de la calidad de vida de las personas.

Na+/Ca2+ exchange and Na+/K+-ATPase in the heart

Science.gov (United States)

Shattock, Michael J; Ottolia, Michela; Bers, Donald M; Blaustein, Mordecai P; Boguslavskyi, Andrii; Bossuyt, Julie; Bridge, John H B; Chen-Izu, Ye; Clancy, Colleen E; Edwards, Andrew; Goldhaber, Joshua; Kaplan, Jack; Lingrel, Jerry B; Pavlovic, Davor; Philipson, Kenneth; Sipido, Karin R; Xie, Zi-Jian

2015-01-01

This paper is the third in a series of reviews published in this issue resulting from the University of California Davis Cardiovascular Symposium 2014: Systems approach to understanding cardiac excitation–contraction coupling and arrhythmias: Na+ channel and Na+ transport. The goal of the symposium was to bring together experts in the field to discuss points of consensus and controversy on the topic of sodium in the heart. The present review focuses on cardiac Na+/Ca2+ exchange (NCX) and Na+/K+-ATPase (NKA). While the relevance of Ca2+ homeostasis in cardiac function has been extensively investigated, the role of Na+ regulation in shaping heart function is often overlooked. Small changes in the cytoplasmic Na+ content have multiple effects on the heart by influencing intracellular Ca2+ and pH levels thereby modulating heart contractility. Therefore it is essential for heart cells to maintain Na+ homeostasis. Among the proteins that accomplish this task are the Na+/Ca2+ exchanger (NCX) and the Na+/K+ pump (NKA). By transporting three Na+ ions into the cytoplasm in exchange for one Ca2+ moved out, NCX is one of the main Na+ influx mechanisms in cardiomyocytes. Acting in the opposite direction, NKA moves Na+ ions from the cytoplasm to the extracellular space against their gradient by utilizing the energy released from ATP hydrolysis. A fine balance between these two processes controls the net amount of intracellular Na+ and aberrations in either of these two systems can have a large impact on cardiac contractility. Due to the relevant role of these two proteins in Na+ homeostasis, the emphasis of this review is on recent developments regarding the cardiac Na+/Ca2+ exchanger (NCX1) and Na+/K+ pump and the controversies that still persist in the field. PMID:25772291

Altered Na+ transport after an intracellular alpha-subunit deletion reveals strict external sequential release of Na+ from the Na/K pump.

Science.gov (United States)

Yaragatupalli, Siddhartha; Olivera, J Fernando; Gatto, Craig; Artigas, Pablo

2009-09-08

The Na/K pump actively exports 3 Na(+) in exchange for 2 K(+) across the plasmalemma of animal cells. As in other P-type ATPases, pump function is more effective when the relative affinity for transported ions is altered as the ion binding sites alternate between opposite sides of the membrane. Deletion of the five C-terminal residues from the alpha-subunit diminishes internal Na(+) (Na(i)(+)) affinity approximately 25-fold [Morth et al. (2007) Nature 450:1043-1049]. Because external Na(+) (Na(o)(+)) binding is voltage-dependent, we studied the reactions involving this process by using two-electrode and inside-out patch voltage clamp in normal and truncated (DeltaKESYY) Xenopus-alpha1 pumps expressed in oocytes. We observed that DeltaKESYY (i) decreased both Na(o)(+) and Na(i)(+) apparent affinities in the absence of K(o)(+), and (ii) did not affect apparent Na(o)(+) affinity at high K(o)(+). These results support a model of strict sequential external release of Na(+) ions, where the Na(+)-exclusive site releases Na(+) before the sites shared with K(+) and the DeltaKESYY deletion only reduces Na(o)(+) affinity at the shared sites. Moreover, at nonsaturating K(o)(+), DeltaKESYY induced an inward flow of Na(+) through Na/K pumps at negative potentials. Guanidinium(+) can also permeate truncated pumps, whereas N-methyl-D-glucamine cannot. Because guanidinium(o)(+) can also traverse normal Na/K pumps in the absence of both Na(o)(+) and K(o)(+) and can also inhibit Na/K pump currents in a Na(+)-like voltage-dependent manner, we conclude that the normal pathway transited by the first externally released Na(+) is large enough to accommodate guanidinium(+).

Active transport of Na+ by reconstituted Na,K-ATPase

International Nuclear Information System (INIS)

Boldyrev, A.A.; Svinukhova, I.A.

1987-01-01

The ability of ATP, CTP, ITP, GTP, and UTP to support ouabain-sensitive accumulation of Na + by proteoliposomes with a reconstituted Na/K-pump was investigated. At a low [Na + ]/[K + ] ratio in the medium (20 mM/50 mM), a correlation is observed between the proton-accepting capacity of the nucleotide and its effectiveness as a substrate of active transport. To test the hypothesis of the importance of the presence of a negative charge in the 1-position of the purine (3-pyrimidine) base of the nucleotide for mutual transitions between the Na- and K-conformations of Na,K-ATPase they used two analogs of ATP: N 1 -hydroxy-ATP, possessing proton acceptor capacity, and N 1 -methoxy-ATP, in the molecule of which the negative charge is quenched by a methyl group. The first substrate supports active accumulation of Na + in proteoliposomes at the same rate as ATP, whereas the second substrate is relatively ineffective

Investigation on U - O - Na, Pu - O - Na and U,Pu - O - Na phase diagrams

International Nuclear Information System (INIS)

Pillon, S.

1989-03-01

The thermochemical interaction between the nuclear fuel (uranium and plutonium mixed oxides) and the sodium has been investigated and particularly the three phase diagrams: U - O - Na; Pu - O - Na; U,Pu - O - Na. High temperature neutron diffraction, microcalorimetry and powder X-ray diffraction were used for the characterization of the compounds synthetized. This study allowed to complete the knowledge about each of these diagrams and to measure some physical and thermal properties on the compounds. The limits on the modelization of the fuel-sodium interaction are discussed from the results of the UO 2 - Na reaction [fr

Measurement of exchangeable sodium: 22Na or 24Na

International Nuclear Information System (INIS)

Smith, T.; Edmonds, C.J.

1987-01-01

A case is made for the use of 22 Na in low activities in preference to 24 Na for routine diagnostic estimation of exchangeable sodium, and is based chiefly on considerations of availability, cost and radiation dosimetry. A method in which only 37 kBq (1 μCi) 22 Na is administered orally is shown to be sufficiently accurate and to possess distinct advantages in terms of cost and convenience with a committed radiation dose no greater than that for a measurement using 24 Na. (author)

La importancia relativa en auditoría. Las nuevas normas internacionales en comparación con la normativa vigente en Iberoamérica

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Francisco Javier Martínez García

2010-01-01

Full Text Available Como se sabe, actualmente estamos inmersos en una profunda crisis financiera internacional. Ante esta situación, resulta necesario introducir, entre otras medidas, mayores y mejores mecanismos de control para lograr una información contable plenamente transparente. En este sentido, la Federación Internacional de Contadores (ifac está revisando y actualizando las Normas Internacionales de Auditoría (nias, que constituyen el referente mundial más importante de los principios y requisitos que deben seguir los auditores para cumplir de la forma más adecuada su función como agentes que garanticen la fiabilidad de la información contable publicada por las empresas. De las nias existentes, se revisaron particularmente la 320 y la 450, las cuales regulan la aplicación de la importancia relativa por los auditores, dada la importancia del concepto en la planeación, ejecución y finalización de las auditorías y las críticas que su inapropiada utilización ha recibido en los últimos años. Específicamente, analizamos el contenido actualizado de ambas normas, que entrarán en vigor a partir del 15 de diciembre de 2009, y las comparamos con sus análogas en Argentina, Brasil, Chile, Colombia, Costa Rica, España, México y Portugal. Debido a la aceptación mundial de las nias, es necesario que los organismos reguladores en estos países emprendan el camino hacia su adopción o convergencia.

Suppression of Na interstitials in Na-F codoped ZnO

Science.gov (United States)

Huo, Wenxing; Mei, Zengxia; Tang, Aihua; Liang, Huili; Du, Xiaolong

2018-04-01

Controlling the formation of interstitial Na (Nai) self-compensating defects has been a long-term physics problem for effective Na doping in ZnO. Herein, we present an experimental approach to the suppression of Nai defects in ZnO via Na and F codoping under an oxygen-rich condition during the molecular beam epitaxy growth process. It is found that the incorporation of such large numbers of Na and F dopants (˜1020 cm-3) does not cause an obvious influence on the lattice parameters. Hall-effect measurements demonstrate that F doping efficiently raises the Fermi level (EF) of ZnO films, which is expected to make the formation energy of Nai and NaZn increase and decrease, respectively. Most of the Na atoms occupy the substitutional Zn sites, and the formation of Nai is suppressed consequently. Secondary ion mass spectrometry measurements reveal that F and Na atoms are tightly bonded together due to their strong Coulomb interaction. The enhanced deep level emission (DLE) in ZnO:Na-F is ascribed to the considerable amount of isolated Zn vacancy (VZn) defects induced by the elevated EF and the formation of neutral (" separators="| FO + - Na Zn - ) 0 complexes. On the other hand, formation of (" separators="| FO + - VZn 2 - ) - complexes in ZnO:F exhausts most of the isolated Zn vacancies, leading to the disappearance of the DLE band.

Suministro de las principales fuentes de energía, proteína y grasa en México, 1961–2010

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Carlos Bruno-Fiscal

2016-12-01

Full Text Available Introducción: El conocimiento relacionado con la disponibilidad de los principales grupos de alimentos y sus aportes de energía, proteína y grasa, es de vital importancia por parte de entes gubernamentales y privados, con el fin de diagnosticar el potencial alimenticio de una región. Material y Métodos: Se utilizó análisis multivariado de la varianza (MANOVA con contraste canónico de tipo ortogonal, análisis de componentes principales, análisis descriptivo exploratorio de tipo unidimensional y análisis Biplot, donde se tuvo en cuenta una base de datos proveniente de la FAO relacionada al suministro medio disponible de energía, proteína y grasa por persona/día de los principales grupos de alimentos en el período comprendido de 1961 a 2010 en México. Dichos datos representan únicamente el suministro medio disponible para la población total y no indican necesariamente consumo real. Resultados: Durante el período de análisis el suministro de carne de ave fue el de mayor aumento, pasando de 10,4g/persona/día a 71,2g/persona/día. Caso contrario al maíz y el frijol, los cuales tuvieron una disminución de 1% y 49% respectivamente. El mayor suministro de energía y proteína lo aportó la leche con 130kcal/persona/día y 7,5g/persona/día de proteína. El mayor aporte de grasa se dio por parte de la carne de cerdo, con 10,8g/persona/día. Conclusiones: Si bien se nota un crecimiento de suministro de vegetales, frutas y hortalizas, este tiene una proporción menor al de la carne, por lo que se debe reorganizar la dieta de los mexicanos por una que contenga aportaciones óptimas para una dieta equilibrada.

OGLAŠEVANJE NA DRUŽBENIH OMREŽJIH NA PRIMERU FACEBOOKA

OpenAIRE

Novak, Martina

2012-01-01

V diplomskem delu obravnavamo družbene medije kot novo priložnost za promocijo in oglaševanje podjetij. Spoznali smo družbena omrežja na splošno in nekaj teh, ki jih uporabljamo tudi v Sloveniji na kratko predstavili. Podrobneje smo se osredotočili na družbeno omrežje Facebook, predvsem na samo spletno stran, njen izgled in storitve, ki jih ponuja uporabnikom. V nalogi je podrobneje opisan Facebook kot orodje za uporabo oglaševanja. Spoznali smo brezplačne in plačljive načine promocije in ogl...

La importancia de la cultura y la política en los procesos de desarrollo

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Alejandro Isla

2007-01-01

Full Text Available El artículo presenta una reflexión pormenorizada sobre la compleja relación de la antropología como ciencia social con la práctica del desarrollo en tanto intervención tendiente a transformar (mejorar los modos de vida de las poblaciones más relegadas. Se detallan una serie de núcleos temáticos que consideramos centrales para comprender más acabadamente el por qué de la relación enrevesada entre antropología y desarrollo. Asimismo se discute la importancia fundamental de los aspectos políticos y culturales de los procesos de desarrollo considerando a dichos procesos como espacios en los que permanentemente se consolidan y reformulan relaciones de poder entre las partes involucradas dando lugar a un sinnúmero de giros, marchas y contramarchas que se apartan substancialmente de los proyectos esbozados. Finalmente, proponemos -desde la antropología- retomar el análisis vigilante de estos aspectos políticos y culturales para dar lugar a procesos de intervención más controlados y más favorables para quienes los reciben.

Las estrategias competitivas y su importancia en la buena gestión de las empresas

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Edgar Castro Monge

2010-01-01

Full Text Available Las estrategias competitivas que desarrollan las empresas son un factor fundamental para saber la forma en que éstas van a competir en los mercados y de ellas dependerá si se tiene o no éxito en su gestión empresarial. Es de suma importancia que las empresas puedan identificar la estrategia o conjunto de estrategias más eficaces para competir eficientemente. Solo estableciendo la estrategia pertinente se pueden lograr las metas y objetivos propuestos por las empresas. Para que una estrategia sea exitosa, ésta debe ser coherente con los valores y las metas, con los recursos y capacidades de la misma, con su entorno, con su estructura y sistemas organizativos. El ensayo pretende entonces hacer un análisis de las cinco tipologías de estrategias competitivas más importantes tratadas en la literatura: Miles y Snow (1978, Porter (1980, Miller (1987, Mintzberg (1988 y Kotler (1992. Se trata de de encontrar sus cuestionamientos, similitudes y diferencias y se pretende dar una guía para que las empresas establezcan la estrategia que mejor se adecúa sus características.

Insectos de importancia forense en cadáveres de ratas, Carabobo - Venezuela

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Jonathan Liria Salazar

2006-01-01

Full Text Available Objetivos: Determinar la composición de la entomofauna asociada con cadáveres de ratas, para identificar las especies de importancia forense en Carabobo, Venezuela. Materiales y métodos: Se estudiaron los insectos en nueve cadáveres de ratas de laboratorio. Diariamente cada rata (cadáver + bandeja con tierra de sustrato fue recogida para obtener la fauna asociada. Con los datos de abundancias se calcularon índices de diversidad y equidad, y se empleó el análisis de componentes principales. Resultados: Se colectaron 13 590 insectos, de los cuales 14,8% correspondieron a cadáveres y 85,2% a bandejas. El orden Diptera fue el más abundante (94,2% seguido por Coleóptera e Hymenóptera (0,2%. Las especies de Diptéra más importantes fueron: Calliphoridae: Lucilia cluvia (Walker, Chrysomya albiceps (Wiedemann y C. megacephala (Fabricius; y Muscidae: Musca domestica Linnaeus. También se encontraron algunos coleópteros como Dermestes ater DeGeer (Dermestidae y Staphylinidae. Conclusiones: La equidad y diversidad fue baja, debido a la dominancia de especies, y la poca sensibilidad de los índices de diversidad a la presencia de especies raras. Se observó la sucesión de especies en donde L. cluvia se relaciona con los primeros días, seguida por C. albiceps y C. megacephala. Se recomienda continuar con estudios relacionados, para su uso como herramienta de ayuda en la medicina legal en Venezuela.

Na+,K+-ATPase Na+ affinity in rat skeletal muscle fiber types

DEFF Research Database (Denmark)

Kristensen, Michael; Juel, Carsten

2010-01-01

Previous studies in expression systems have found different ion activation of the Na(+)/K(+)-ATPase isozymes, which suggest that different muscles have different ion affinities. The rate of ATP hydrolysis was used to quantify Na(+),K(+)-ATPase activity, and the Na(+) affinity of Na(+),K(+)-ATPase...

La importancia del mundo virtual en la enseñanza y aprendizaje “AVA para el contenido de Genética”.

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Alexander Afanador Castañeda

2011-02-01

Full Text Available El presente escrito describe la importancia y la necesidad de incorporar las TIC en los procesos de enseñanza y aprendizaje de las ciencias, además la utilización de ambientes virtuales de aprendizajes como alternativa innovadora y eficaz para la adquisición y comunicación del conocimiento científico, y hace referencia a la necesidad de incorporar la evaluación formativa en medios virtuales. Por último se presenta un ambiente virtual de aprendizaje como estrategia didáctica teniendo en cuenta la resolución de problemas para la apropiación del contenido conceptual en Genética con su respectivo guión pedagógico.

Crystal structure of Na+, K(+)-ATPase in the Na(+)-bound state.

Science.gov (United States)

Nyblom, Maria; Poulsen, Hanne; Gourdon, Pontus; Reinhard, Linda; Andersson, Magnus; Lindahl, Erik; Fedosova, Natalya; Nissen, Poul

2013-10-04

The Na(+), K(+)-adenosine triphosphatase (ATPase) maintains the electrochemical gradients of Na(+) and K(+) across the plasma membrane--a prerequisite for electrical excitability and secondary transport. Hitherto, structural information has been limited to K(+)-bound or ouabain-blocked forms. We present the crystal structure of a Na(+)-bound Na(+), K(+)-ATPase as determined at 4.3 Å resolution. Compared with the K(+)-bound form, large conformational changes are observed in the α subunit whereas the β and γ subunit structures are maintained. The locations of the three Na(+) sites are indicated with the unique site III at the recently suggested IIIb, as further supported by electrophysiological studies on leak currents. Extracellular release of the third Na(+) from IIIb through IIIa, followed by exchange of Na(+) for K(+) at sites I and II, is suggested.

Eventos de Desconexao na Cauda de Plasma do Cometa P/Halley

Science.gov (United States)

Voelzke, M. R.; Fahr, H. J.

2001-08-01

Observacoes cometárias e de vento solar sao comparadas com o propósito de determinar-se as condicoes do vento solar associadas aos eventos de desconexao (DEs) observados em caudas de plasma cometárias. Os dados cometários sao provenientes do The International Halley Watch Atlas of Large-Scale Phenomena. A análise visual sistemática das imagens do atlas revelou, entre outras estruturas morfológicas, 47 DEs ao longo da cauda de plasma do P/Halley. Estes 47 DEs registrados em 47 imagens distintas permitiram a descoberta de 19 origens de DEs, ou seja, o tempo em que as desconexoes iniciaram foi calculado. Os dados do vento solar sao provenientes de medidas feitas in situ pela sonda espacial IMP-8, as quais foram usadas para elaborar a variacao da velocidade do vento solar, densidade e pressao dinâmica durante o intervalo analisado. O presente trabalho compara as atuais teorias conflitantes, baseadas nos mecanismos de formacao, com o intuito de explicar o fenômeno cíclico dos DEs, ou seja, os efeitos de producao iônica, os efeitos de pressao e os efeitos de reconexao magnética sao analisados. Para cada uma das 19 origens de DEs comparou-se a densidade com a respectiva velocidade do vento solar com o intuito de determinar-se uma possível correlacao entre estas origens e os efeitos de pressao dinâmica. Quando da ocorrência de 6 origens de DEs o IMP-8 nao realizou medidas, nos outros 13 casos 10 origens (77%) mostraram uma anticorrelacao entre velocidade e densidade e apenas 3 (23%) revelaram uma tendência similar entre velocidade e densidade. Portanto, a análise inicial demonstra uma fraca correlacao entre as origens dos DEs e os efeitos de pressao.

La importancia de la historia y la epistemología de las ciencias para la organización lógica del discurso químico

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Ruth Sánchez Sánchez

2009-10-01

Full Text Available El siguiente documento pretende resaltar la importancia de la historia y la epistemología de las ciencias, en particular de la química, en la presentación del discurso químico de una manera lógica, teniendo en cuenta la clarificación de la naturaleza históricoepistemológica de los conceptos, asumiendo los criterios teóricos de organización lógica del discurso químico que plantea Jensen.

Meltability in system of K2TaF7-NaF-NaCl-KCl

International Nuclear Information System (INIS)

Kartsev, V.E.; Kovalev, F.V.; Korshunov, B.G.

1975-01-01

Thermographic and visual-polythermal techniques were used to study the meltability in K 2 TaF 7 -NaF-NaCl-KCl system. The tetrahedron-forming sections NaF-NaCl-K 2 TaF 7 xKCl and NaF-K 2 TaF 7 xKCl-2K 2 TaF 7 xNaCl divide the concentration tetrahedron into three particular tetrahedra: NaF-K 2 TaF 7 xKCl-2K 2 TaF 7 xNaCl-K 2 TaF 7 , NaF-NaCl-K 2 TaF 7 xKCl-2K 2 TaF 7 xaCl, and NaF-NaCl-KCl-K 2 TaF 7 xKCl. Non-variant equilibrium points in all of the particular four-component systems have been determined

Importancia del manual de los sistemas contables en el sistema de control interno.

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Nicolás Valdés Rodríguez

2007-01-01

Full Text Available La dirección administrativa del país en los últimos 3 años ha insistido en la necesidad de profundizar en los mecanismos de control económico –financiero de las entidades, el presente trabajo va dirigido a contribuir en alguna medida a lograr ese propósito. El sistema contable de una Entidad forma parte indisoluble del Sistema de Control Interno de la misma, por la vinculación tan estrecha que existe entre los mismos. El objetivo fundamental del trabajo ”Importancia del Manual de los Sistemas Contables en el Sistema de Control Interno”, es destacar la utilidad práctica, técnica y organizativa que tiene el Manual para elevar la eficiencia del trabajo contable de las Entidades y su repercusión positiva en la eficiencia el sistema de Control Interno establecido. Los beneficios que aporta el Manual radican en que crea una base normativa contable adecuada a las características de cada entidad. Como se sabe en las transformaciones económicas realizadas en el país, la existencia de dos monedas en el trabajo económico-contable de muchas entidades, la puntualización del objeto social y la cartera de productos y servicios han complejizado el trabajo contable, requiriendo una mayor adecuación a las características propias de cada entidad, lo cual se logra con la realización del Manual.

Active transport of Na/sup +/ by reconstituted Na,K-ATPase

Energy Technology Data Exchange (ETDEWEB)

Boldyrev, A.A.; Svinukhova, I.A.

1987-02-20

The ability of ATP, CTP, ITP, GTP, and UTP to support ouabain-sensitive accumulation of Na/sup +/ by proteoliposomes with a reconstituted Na/K-pump was investigated. At a low (Na/sup +/)/(K/sup +/) ratio in the medium (20 mM/50 mM), a correlation is observed between the proton-accepting capacity of the nucleotide and its effectiveness as a substrate of active transport. To test the hypothesis of the importance of the presence of a negative charge in the 1-position of the purine (3-pyrimidine) base of the nucleotide for mutual transitions between the Na- and K-conformations of Na,K-ATPase they used two analogs of ATP: N/sub 1/-hydroxy-ATP, possessing proton acceptor capacity, and N/sub 1/-methoxy-ATP, in the molecule of which the negative charge is quenched by a methyl group. The first substrate supports active accumulation of Na/sup +/ in proteoliposomes at the same rate as ATP, whereas the second substrate is relatively ineffective.

Relationship between intracellular Na+ concentration and reduced Na+ affinity in Na+,K+-ATPase mutants causing neurological disease

DEFF Research Database (Denmark)

Toustrup-Jensen, Mads Schak; Einholm, Anja P.; Schack, Vivien

The neurological disorders familial hemiplegic migraine type 2 (FHM2), alternating hemiplegia of childhood (AHC), and rapid-onset dystonia parkinsonism (RDP) are caused by mutations of Na+,K+-ATPase α2 and α3 isoforms, expressed in glial and neuronal cells, respectively. Although these disorders......, addressing the question to what extent they cause a change of the intracellular Na+ and K+ concentrations ([Na+]i and [K+]i) in COS cells. C-terminal extension mutants generally showed dramatically reduced Na+ affinity without disturbance of K+ binding, as did other RDP mutants. No phosphorylation from ATP...

MOŽNOSTI VSTOPA NA TUJE TRGE NA PRIMERU PODJETJA AWOODTURE

OpenAIRE

Orličnik, Urša

2014-01-01

Danes pojavljanje podjetja samo na domačem trgu ni več dovolj. Spremembe okolja, naraščanje konkurence ter hiter tehnološki napredek, silijo podjetja k nenehnemu prilagajanju in iskanju novih priložnosti tako na domačem kot tudi na tujem trgu. Internacionalizacija podjetja tako postaja vedno bolj pomemembna za preživetje podjetja. Internacionalizacija se v najširšem smislu nanaša na vse oblike mednarodnega ekonomskega sodelovanja. Je dinamičen proces, kateremu nujno sledi sprememba stanja...

Na/K pump inactivation, subsarcolemmal Na measurements, and cytoplasmic ion turnover kinetics contradict restricted Na spaces in murine cardiac myocytes

OpenAIRE

Lu, Fang-Min; Hilgemann, Donald W.

2017-01-01

The Na/K pump exports cytoplasmic Na ions while importing K ions, and its activity is thought to be affected by restricted intracellular Na diffusion in cardiac myocytes. Lu and Hilgemann find instead that the pump can enter an inactivated state and that inactivation can be relieved by cytoplasmic Na.

La importancia del «país de origen» en la fase de evaluación del consumidor de productos hortícolas

OpenAIRE

Jiménez Guerrero, José Felipe; Gázquez Abad, Juan Carlos; Linares Agüera, Emilia del Carmen

2010-01-01

La percepción sobre el país de origen de un producto es uno de los principales determinantes de la evaluación y elección de dicho producto, sobre todo en los mercados foráneos. En la literatura de marketing existen múltiples trabajos que han analizado este aspecto, si bien la mayor parte de ellos se han centrado en productos duraderos de alta implicación. Este trabajo analiza la importancia que el atributo país de origen tiene en el proceso de evaluación del consumidor para el caso de la comp...

La importancia de la educación ambiental ante la problemática actual

Directory of Open Access Journals (Sweden)

Róger Martínez-Castillo

2010-06-01

Full Text Available Recibido 15 de febrero de 2010 • Aceptado 17 de marzo de 2010 • Corregido 05 de abril de 2010   El sistema de desarrollo dominante, con sus políticas neoliberales y enfoques mercado-céntricos contribuye a agravar los problemas socio-ambientales, bajo un contexto de la globalización del mercado. Por eso, la preocupación por el manejo sustentable del ambiente, hace imperiosa la necesidad de estructurar una educación ambiental que forme e informe acerca de esta problemática. En este sentido, la educación ambiental viene a constituir el proceso educativo que se ocupa de la relación del ser humano con su ambiente (natural y artificial y consigo mismo, así como las consecuencias de esta relación. De esta manera, la educación ambiental debe constituir un proceso integral, que juega su papel en todo el entramado de la enseñanza y el aprendizaje. Para ello, es necesario establecer un proceso educativo que cuestione la relación de cualquier tema o actividad del ser humano, dentro de un análisis de la importancia o incidencia en la vida social y ambiental, como es la parte pedagógica y su esencia política.

La importancia de las redes sociales en los orígenes de la industria farmacéutica argentina. El caso de los catalanes

OpenAIRE

Campins, Mónica; Pfeiffer, Ana

2011-01-01

El artículo que se presenta pretende ser un aporte hacia una interpretación más amplia del desarrollo de las industrias de base científica en países de industrialización tardía como Argentina. El enfoque utilizado en el trabajo de investigación se apoya en los aportes de Nuria Puig sobre el papel de las redes sociales en el desarrollo de la industria farmacéutica en los países de industrialización tardía y refuerza la tesis de Franco Ramella acerca de la importancia del uso fuerte del conc...

Vpliv toplotnih mostov na porabo energije za ogrevanje na primeru osnovne šole

OpenAIRE

Megušar, Primož

2015-01-01

Na primeru Osnovne šole Dobrova sem preveril, kakšen vpliv imajo dejanski toplotni mostovi na porabo energije za ogrevanje. Iz načrtov stavbe sem evidentiral vse toplotne mostove, kateri vplivajo na porabo energije. Tem toplotnim mostovom sem nato v standardu SIST EN ISO 14683 poiskal ustrezne približke. Nato sem s programom TOST izvedel tri simulacije. V prvem primeru toplotnih mostov nisem upošteval. V drugem primeru sem toplotne mostove upošteval na poenostavljen način, v zadnjem primeru p...

Na and K dependence of the Na/K pump in cystic fibrosis fibroblasts.

OpenAIRE

Reznik, V M; Schneider, J A; Mendoza, S A

1981-01-01

The Na and K dependence of the Na/K pump was measured in skin fibroblasts from patients with cystic fibrosis and age/sex-matched controls. Under basal conditions, there was no difference between control and cystic fibrosis cells in protein per cell, intracellular Na and K content, or Na/K pump activity (measured as ouabain-sensitive 86Rb uptake). There was no difference in the Na dependence of the Na/K pump between cystic fibrosis cells and control cells. In cells from patients with cystic fi...

Importancia de la capacitación especializada del personal administrativo en el desarrollo de la gestión empresarial

Directory of Open Access Journals (Sweden)

Jannina Soto

2016-06-01

Estamos ejecutando la primera fase del proyecto, es decir diseño y aplicación de encuestas al personal de la Universidad, a fin de realizar el respectivo diagnóstico de formación laboral del personal administrativo, y elaborar un programa de mejoramiento para la optimización administrativa, y proyectarnos hacia la creación de un Centro de Capacitación Continua. Destacamos la importancia que tiene la capacitación del Talento Humano para la institución y para el desarrollo socio-económico del país, razón por la cual la fortaleceremos en el área técnica, competencias de atención al usuario, procesos de desempeño administrativos y humanos para proyectar así, de mejor forma, la imagen institucional de manera interna y externa

Vliv mikroflóry na senzorické vlastnosti vína

OpenAIRE

Petrášová, Ludmila

2014-01-01

Tato bakalářská práce se zabývá vlivem mikroflóry na senzorické vlastnosti vína. Teoretická část informuje o botanickém popisu hroznů vína Veltlínské zelené, dále o jeho složení, o technologii zpracování bílého vína a o vlivu kvasinek na aromatický profil vína. V další části popisuje metodu stanovení aromaticky aktivních látek pomocí plynové chromatografie v kombinaci s mikroextrakcí tuhou fází (SPME-GC). Cílem experimentální části bylo proměřit vzorky 4 různých moštů odrůdy Veltlínské zelené...

Importancia de implementar el bienestar animal durante embarque y desembarque de bovinos

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Laura Marcela Arias Sánchez

2016-12-01

Full Text Available La ciencia del bienestar animal permite dar al animal las condiciones idóneas para mejorar su calidad de vida, esta ciencia evalúa el estado de un individuo frente a los intentos de afrontar los cambios del ambiente, basándose en el estado físico, fisiológico y mental de cada animal. En los sistemas de producción bovinos se desarrollan actividades que conllevan cambio de ambiente para los animales y el aumento de la interacción humano – animal, lo que ocasiona una alteración de las condiciones físicas, mentales y fisiológicas del animal, donde la actividad que genera mayores alteraciones en los bovinos es el transporte, especialmente el embarque y el desembarque, debido a las caídas, golpes, resbalones y cambios de ambiente que se reflejan en la presencia de hematomas, fracturas, contusiones y aumento de los niveles de estrés. Lo cual genera  lesiones de la canal que son el resultado de un impacto de los tejidos blandos acompañado de la ruptura de vasos sanguíneos y alteración de las propiedades organolépticas de la carne, donde el parámetro más importante es el pH, ya que si éste aumenta por los elevados niveles de estrés ante-mortem, favorece la proliferación de microorganismos, reduciendo así la vida útil del producto y convirtiendo el producto en un riesgo para la salud pública. Es por ello que el presente artículo busca identificar y analizar la importancia de implementar el bienestar animal en las actividades de embarque y desembarque en los sistemas de producción bovinos.

El valor de las marcas en el siglo XXI: la marca país y su importancia para el desarollo de Puerto Rico

OpenAIRE

Hernández Cruz, Damaris

2016-01-01

La investigación aborda los temas del valor de las marcas, la importancia de la publicidad para el éxito de las marcas y cómo la ‘Marca País’ puede ayudar al desarrollo de un país, en este caso Puerto Rico. Los objetivos de la investigación son analizar si las marcas pueden ser éticas, cuán importante es la publicidad para que las marcas alcancen el éxito y cómo la ‘Marca País’ puede ayudar al desarrollo de Puerto Rico. Las marcas son mucho más que un nombre o símbolo. Las marcas envuelven va...

Study of the Na-C-O and Na-H-O ternary systems in the sodium rich corner

International Nuclear Information System (INIS)

Maupre, J.-P.

1978-02-01

The purpose of this study is to provide a contribution to the understanding of the sodium - carbon - oxygen and sodium - hydrogen - oxygen ternary systems in the sodium rich corner. In order to do this the Na-NaH-Na 2 O-NaOH phase diagram was completed and the Na-Na 2 O-Na 2 CO 3 -C phase diagram was outlined. This work is made up of two parts. The first is devoted to a critical literature survey essential to establish correct phase diagrams. The second is an experimental study followed by a discussion collating our finding to the literary data. The basic experimental technique used is differential thermal analysis (DTA) but it has been completed by quenching, X-ray and chemical analysis methods. The proposed phase diagrams imply that Na-NaH-Na 2 O-NaOH and Na-Na 2 O-Na 2 CO 3 -C systems are reciprocal ternary systems. Temperatures of stable pairs reversal are respectively 410 and 690 0 C. The stable pairs are Na-NaOH and Na-Na 2 CO 3 at elevated temperature, Na 2 O-NaH and Na 2 O-C at low temperature [fr

Response of saliva Na/K ratio to changing Na supply of lactating cows under tropical conditions.

Science.gov (United States)

Thiangtum, Wandee; Schonewille, J Thomas; Verstegen, Martin Wa; Arsawakulsudhi, Supot; Rukkwamsuk, Theera; Hendriks, Wouter H

2017-06-01

Factorial determination of the sodium (Na) requirement of heat-stressed lactating cows is hindered by accurate estimates of the Na losses through sweat. Direct studies, therefore, may be needed requiring information on the time course of healthy animals to become Na depleted and the subsequent rate of repletion. The rate of Na depletion and subsequent rate of Na repletion with two levels of dietary Na to lactating dairy cows housed under tropical conditions were investigated using the salivary Na/K. The 12 lactating cows (salivary Na/K ratio 14.6) rapidly developed clinical signs of Na deficiency, including pica, polyuria and polydipsia, reduced body weight and reduced milk yield when fed a low-Na ration (0.33 g kg -1 dry matter (DM)) for 3 weeks. Deficiency symptoms were associated with a rapid decrease in salivary Na/K ratio to cows with NaCl to a ration concentration of 1.1 or 1.6 g Na kg -1 DM for 5 weeks did not restore salivary Na/K ratio to values of >6. A daily Na intake of heat-stressed lactating cows to a ration intake of 1.6 g Na kg -1 DM was insufficient to restore Na deficiency. One week was sufficient to deplete heat-stressed lactating cows of Na, allowing for rapid dose-response studies utilizing the salivary Na/K ratio as a parameter for Na status of cows under tropical conditions. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Entonación, intención y relevancia. La importancia de la entonación y su enseñanza en el aula de ELE. Algunas propuestas didácticas

Directory of Open Access Journals (Sweden)

Molina Vidal, Isabel

2014-09-01

Full Text Available La enseñanza de la entonación sigue siendo una asignatura pendiente en el aula de ELE no solo por la escasa atención que recibe por parte de los docentes, sino también por el enfoque didáctico empleado, que ignora su dimensión pragmática. En este artículo, y tomando como punto de partida la teoría de los actos de habla, la teoría de la relevancia así como estudios provenientes del campo de la psicología, se pone de relieve el papel que juega la entonación en el discurso oral, cómo contribuye a revelar la intención comunicativa del hablante y, en definitiva, la importancia de su enseñanza para que los estudiantes se comuniquen de una manera más rica y eficaz. A continuación, se proponen algunas actividades que tienen como objetivo, por un lado, despertar la conciencia del alumnado sobre la importancia de la entonación y, por otro, fomentar la reflexión y la práctica de la entonación teniendo en cuenta las intenciones del hablante y el contexto comunicativo.

Glutathionylation-Dependence of Na+-K+-Pump Currents Can Mimic Reduced Subsarcolemmal Na+ Diffusion

Science.gov (United States)

Garcia, Alvaro; Liu, Chia-Chi; Cornelius, Flemming; Clarke, Ronald J.; Rasmussen, Helge H.

2016-01-01

The existence of a subsarcolemmal space with restricted diffusion for Na+ in cardiac myocytes has been inferred from a transient peak electrogenic Na+-K+ pump current beyond steady state on reexposure of myocytes to K+ after a period of exposure to K+-free extracellular solution. The transient peak current is attributed to enhanced electrogenic pumping of Na+ that accumulated in the diffusion-restricted space during pump inhibition in K+-free extracellular solution. However, there are no known physical barriers that account for such restricted Na+ diffusion, and we examined if changes of activity of the Na+-K+ pump itself cause the transient peak current. Reexposure to K+ reproduced a transient current beyond steady state in voltage-clamped ventricular myocytes as reported by others. Persistence of it when the Na+ concentration in patch pipette solutions perfusing the intracellular compartment was high and elimination of it with K+-free pipette solution could not be reconciled with restricted subsarcolemmal Na+ diffusion. The pattern of the transient current early after pump activation was dependent on transmembrane Na+- and K+ concentration gradients suggesting the currents were related to the conformational poise imposed on the pump. We examined if the currents might be accounted for by changes in glutathionylation of the β1 Na+-K+ pump subunit, a reversible oxidative modification that inhibits the pump. Susceptibility of the β1 subunit to glutathionylation depends on the conformational poise of the Na+-K+ pump, and glutathionylation with the pump stabilized in conformations equivalent to those expected to be imposed on voltage-clamped myocytes supported this hypothesis. So did elimination of the transient K+-induced peak Na+-K+ pump current when we included glutaredoxin 1 in patch pipette solutions to reverse glutathionylation. We conclude that transient K+-induced peak Na+-K+ pump current reflects the effect of conformation-dependent β1 pump subunit

Glutathionylation-Dependence of Na(+)-K(+)-Pump Currents Can Mimic Reduced Subsarcolemmal Na(+) Diffusion.

Science.gov (United States)

Garcia, Alvaro; Liu, Chia-Chi; Cornelius, Flemming; Clarke, Ronald J; Rasmussen, Helge H

2016-03-08

The existence of a subsarcolemmal space with restricted diffusion for Na(+) in cardiac myocytes has been inferred from a transient peak electrogenic Na(+)-K(+) pump current beyond steady state on reexposure of myocytes to K(+) after a period of exposure to K(+)-free extracellular solution. The transient peak current is attributed to enhanced electrogenic pumping of Na(+) that accumulated in the diffusion-restricted space during pump inhibition in K(+)-free extracellular solution. However, there are no known physical barriers that account for such restricted Na(+) diffusion, and we examined if changes of activity of the Na(+)-K(+) pump itself cause the transient peak current. Reexposure to K(+) reproduced a transient current beyond steady state in voltage-clamped ventricular myocytes as reported by others. Persistence of it when the Na(+) concentration in patch pipette solutions perfusing the intracellular compartment was high and elimination of it with K(+)-free pipette solution could not be reconciled with restricted subsarcolemmal Na(+) diffusion. The pattern of the transient current early after pump activation was dependent on transmembrane Na(+)- and K(+) concentration gradients suggesting the currents were related to the conformational poise imposed on the pump. We examined if the currents might be accounted for by changes in glutathionylation of the β1 Na(+)-K(+) pump subunit, a reversible oxidative modification that inhibits the pump. Susceptibility of the β1 subunit to glutathionylation depends on the conformational poise of the Na(+)-K(+) pump, and glutathionylation with the pump stabilized in conformations equivalent to those expected to be imposed on voltage-clamped myocytes supported this hypothesis. So did elimination of the transient K(+)-induced peak Na(+)-K(+) pump current when we included glutaredoxin 1 in patch pipette solutions to reverse glutathionylation. We conclude that transient K(+)-induced peak Na(+)-K(+) pump current reflects the effect

Teledetección no es Tele-adivinación: La importancia de las causas en Viticultura de Precisión

Directory of Open Access Journals (Sweden)

Gómez-Miguel Vicente D.

2017-01-01

Full Text Available La cartografía realizada a partir de la información procedente de sensores remotos es un producto de actualidad que se ofrece con éxito gracias principalmente a su atractiva presentación y a su bajo coste. La información se obtiene mediante sensores instalados en satélites, aviones y otras aeronaves a alta, media o baja altura, tripuladas o no y en vehículos terrestres autopropulsados o no. Los sensores y elementos asociados son capaces de procesar la radiación de gran parte del espectro electromagnético y convertirla en imágenes que representan la emisión de una determinada zona geográfica. A pesar de que el procedimiento puede llegar a ser muy sofisticado, el resultado que se proporciona al viticultor con mayor o menor detalle (resolución o más o menos elaborado, es prácticamente siempre el mismo: uno o varios mapas en los que se recoge la respuesta obtenida por el sensor de lo que hay en la parcela en el preciso momento en el que pasa el vehículo en el que se ha instalado. Por lo tanto, este mapa representa la respuesta del estado “electromagnético” de una parcela en un momento determinado, sin embargo, las causas de la variabilidad que se aprecia en el propio mapa se desconocen. Estas causas son muy complejas y se relacionan principalmente con la variabilidad de los elementos del clima, la geología, el relieve, el suelo, la planta y el momento de realización del proceso. Factores todos ellos de gran importancia en la configuración del terroir y que influyen en la calidad del producto. En este trabajo tratamos del alcance real de la teledetección y de la importancia de la cartografía de las causas que inciden en la heterogeneidad de la parcela/explotación para un uso adecuado en Viticultura de Precisión, todo ello dentro de un modelo general de producción vitícola para la obtención de vinos de calidad.

La calidad y el valor percibido en el transporte de mercancías en España y su importancia en la segmentación de clientes

OpenAIRE

Irene Gil Saura; Gloria Berenguer Contrí; María Eugenia Ruiz Molina; Santiago Ospina Pinzón

2015-01-01

En el estudio académico de las actividades logísticas y específicamente del transporte de mercancías, se ha señalado la influencia de la calidad del servicio en la generación y percepción de valor, así como la importancia de estos dos constructos en el proceso de evaluación del servicio en este entorno particular. En este trabajo se pretende identificar y caracterizar segmentos de empresas que prestan servicios de gestión del transporte internacional de mercancías (transitarias), con ba...

Crystal structure of a Na+-bound Na+,K+-ATPase preceding the E1P state.

Science.gov (United States)

Kanai, Ryuta; Ogawa, Haruo; Vilsen, Bente; Cornelius, Flemming; Toyoshima, Chikashi

2013-10-10

Na(+),K(+)-ATPase pumps three Na(+) ions out of cells in exchange for two K(+) taken up from the extracellular medium per ATP molecule hydrolysed, thereby establishing Na(+) and K(+) gradients across the membrane in all animal cells. These ion gradients are used in many fundamental processes, notably excitation of nerve cells. Here we describe 2.8 Å-resolution crystal structures of this ATPase from pig kidney with bound Na(+), ADP and aluminium fluoride, a stable phosphate analogue, with and without oligomycin that promotes Na(+) occlusion. These crystal structures represent a transition state preceding the phosphorylated intermediate (E1P) in which three Na(+) ions are occluded. Details of the Na(+)-binding sites show how this ATPase functions as a Na(+)-specific pump, rejecting K(+) and Ca(2+), even though its affinity for Na(+) is low (millimolar dissociation constant). A mechanism for sequential, cooperative Na(+) binding can now be formulated in atomic detail.

Na+-H+ exchange and Na+-dependent transport systems in streptozotocin diabetic rat kidneys

International Nuclear Information System (INIS)

El-Seifi, S.; Freiberg, J.M.; Kinsella, F.J.; Cheng, L.; Sacktor, B.

1987-01-01

The streptozotocin-induced diabetic rat was used to test the hypothesis that Na + -H + exchange activity in the proximal tubule luminal membrane would be increased in association with renal hypertrophy, altered glomerular hemodynamics, enhanced filtered load and tubular reabsorption of 22 Na + , and stimulated 22 Na= pump activity in the basolateral membrane, previously reported characteristics of this experimental animal model. Amiloride-sensitive H + gradient-dependent Na + uptake and Na + gradient-dependent H + flux were increased in brush-border membrane vesicles from the streptozotocin-treated animals. Na + gradient-dependent uptakes of phosphate, D-glucose, L-proline, and myoinositol were decreased in the drug-induced diabetic animals. These membrane transport alterations were not found when the streptozotocin-diabetic animals were treated with insulin

The two C-terminal tyrosines stabilize occluded Na/K pump conformations containing Na or K ions.

Science.gov (United States)

Vedovato, Natascia; Gadsby, David C

2010-07-01

Interactions of the three transported Na ions with the Na/K pump remain incompletely understood. Na/K pump crystal structures show that the extended C terminus of the Na,K-adenosine triphosphatase (ATPase) alpha subunit directly contacts transmembrane helices. Deletion of the last five residues (KETYY in almost all Na/K pumps) markedly lowered the apparent affinity for Na activation of pump phosphorylation from ATP, a reflection of cytoplasmic Na affinity for forming the occluded E1P(Na3) conformation. ATPase assays further suggested that C-terminal truncations also interfere with low affinity Na interactions, which are attributable to extracellular effects. Because extracellular Na ions traverse part of the membrane's electric field to reach their binding sites in the Na/K pump, their movements generate currents that can be monitored with high resolution. We report here electrical measurements to examine how Na/K pump interactions with extracellular Na ions are influenced by C-terminal truncations. We deleted the last two (YY) or five (KESYY) residues in Xenopus laevis alpha1 Na/K pumps made ouabain resistant by either of two kinds of point mutations and measured their currents as 10-mM ouabain-sensitive currents in Xenopus oocytes after silencing endogenous Xenopus Na/K pumps with 1 microM ouabain. We found the low affinity inhibitory influence of extracellular Na on outward Na/K pump current at negative voltages to be impaired in all of the C-terminally truncated pumps. Correspondingly, voltage jump-induced transient charge movements that reflect pump interactions with extracellular Na ions were strongly shifted to more negative potentials; this signals a several-fold reduction of the apparent affinity for extracellular Na in the truncated pumps. Parallel lowering of Na affinity on both sides of the membrane argues that the C-terminal contacts provide important stabilization of the occluded E1P(Na3) conformation, regardless of the route of Na ion entry into the

Anion-coupled Na efflux mediated by the human red blood cell Na/K pump

International Nuclear Information System (INIS)

Dissing, S.; Hoffman, J.F.

1990-01-01

The red cell Na/K pump is known to continue to extrude Na when both Na and K are removed from the external medium. Because this ouabain-sensitive flux occurs in the absence of an exchangeable cation, it is referred to as uncoupled Na efflux. This flux is also known to be inhibited by 5 mM Nao but to a lesser extent than that inhibitable by ouabain. Uncoupled Na efflux via the Na/K pump therefore can be divided into a Nao-sensitive and Nao-insensitive component. We used DIDS-treated, SO4-equilibrated human red blood cells suspended in HEPES-buffered (pHo 7.4) MgSO4 or (Tris)2SO4, in which we measured 22Na efflux, 35SO4 efflux, and changes in the membrane potential with the fluorescent dye, diS-C3 (5). A principal finding is that uncoupled Na efflux occurs electroneurally, in contrast to the pump's normal electrogenic operation when exchanging Nai for Ko. This electroneutral uncoupled efflux of Na was found to be balanced by an efflux of cellular anions. (We were unable to detect any ouabain-sensitive uptake of protons, measured in an unbuffered medium at pH 7.4 with a Radiometer pH-STAT.) The Nao-sensitive efflux of Nai was found to be 1.95 +/- 0.10 times the Nao-sensitive efflux of (SO4)i, indicating that the stoichiometry of this cotransport is two Na+ per SO4=, accounting for 60-80% of the electroneutral Na efflux. The remainder portion, that is, the ouabain-sensitive Nao-insensitive component, has been identified as PO4-coupled Na transport and is the subject of a separate paper. That uncoupled Na efflux occurs as a cotransport with anions is supported by the result, obtained with resealed ghosts, that when internal and external SO4 was substituted by the impermeant anion, tartrate i,o, the efflux of Na was inhibited 60-80%. This inhibition could be relieved by the inclusion, before DIDS treatment, of 5 mM Cli,o

Na5NbO5 and Na5TaO5 phases

International Nuclear Information System (INIS)

Darriet, J.; Maazaz, A.; Bouloux, J.C.; Delmas, C.

1982-01-01

New ternary oxides of formulas Na 5 NbO 5 and Na 5 TaO 5 have been prepared. They crystallize in the monoclinic system (space group C2/c). The crystal structure of Na 5 NbO 5 has been determined. It derives from a NaCl-type structure by ordering of the cations and of the oxygen vacancies in the anionic sublattice, the corresponding formula being Nasub(5/6)Nbsub(1/6)Osub(5/6)vacant sub(1/6). Sodium and niobium have a distorted square-pyramidal surrounding. (author)

Synthesis of Na-A and/or Na-X zeolite/porous carbon composites from carbonized rice husk

International Nuclear Information System (INIS)

Katsuki, Hiroaki; Komarneni, Sridhar

2009-01-01

Na-A and/or Na-X zeolite/porous carbon composites were prepared under hydrothermal conditions by NaOH dissolution of silica first from carbonized rice husk followed by addition of NaAlO 2 and in situ crystallization of zeolites i.e., using a two-step process. When a one-step process was used, both Na-A and Na-X zeolites crystallized on the surface of carbon. Na-A or Na-X zeolite crystals were prepared on the porous carbonized rice husk at 90 deg. C for 2-6 h by changing the SiO 2 /Al 2 O 3 , H 2 O/Na 2 O and Na 2 O/SiO 2 molar ratios of precursors in the two-step process. The surface area and NH 4 + -cation exchange capacity (CEC) of Na-A zeolite/porous carbon were found to be 171 m 2 /g and 506 meq/100 g, respectively, while those of Na-X zeolite/porous carbon composites were 676 m 2 /g and 317 meq/100 g, respectively. Na-A and Na-X zeolites are well-known microporous and hydrophilic materials while carbonized rice husk was found to be mesoporous (pores of ∼3.9 nm) and hydrophobic. These hybrid microporous-mesoporous and hydrophilic-hydrophobic composites are expected to be useful for decontamination of metal cations as well as organic contaminants simultaneously. - Graphical Abstract: Novel Na-X zeolite/porous carbon composite.

Equilibrium chemical transformations in NaPO3 + NaCl melts

International Nuclear Information System (INIS)

Kovarskaya, E.N.; Rodionov, Yu.I.

1988-01-01

Because of the problems of the burial of solidified radioactive wastes into different geological rock formations, in particular into massives of rock-salt, the state of molten polyphosphate-chloride mixtures (taking into account the chemical character of the interaction of their components) for a prolonged period of time. The equilibrium products of the reaction in the NaPO 3 -NaCl system were studied in melts in air in the composition range of 30-70 mole % NaCl. It was shown that with increase in the NaCl content in the mixtures, the polyphosphate gradually depolymerizes to sodium tri-, di-, and monophosphates, and the composition of the equilibrium melts is dependent only on the ratio between the components in the initial molten mixtures. The time until the equilibrium is attained is shorter, the higher is the experimental temperature

Long-Range Effects of Na(+) Binding in Na,K-ATPase Reported by ATP.

Science.gov (United States)

Middleton, David A; Fedosova, Natalya U; Esmann, Mikael

2015-12-01

This paper addresses the question of long-range interactions between the intramembranous cation binding sites and the cytoplasmic nucleotide binding site of the ubiquitous ion-transporting Na,K-ATPase using (13)C cross-polarization magic-angle spinning (CP-MAS) solid-state nuclear magnetic resonance. High-affinity ATP binding is induced by the presence of Na(+) as well as of Na-like substances such as Tris(+), and these ions are equally efficient promoters of nucleotide binding. CP-MAS analysis of bound ATP with Na,K-ATPase purified from pig kidney membranes reveals subtle differences in the nucleotide interactions within the nucleotide site depending on whether Na(+) or Tris(+) is used to induce binding. Differences in chemical shifts for ATP atoms C1' and C5' observed in the presence of Na(+) or Tris(+) suggest alterations in the residues surrounding the bound nucleotide, hydrogen bonding, and/or conformation of the ribose ring. This is taken as evidence of a long-distance communication between the Na(+)-filled ion sites in the membrane interior and the nucleotide binding site in the cytoplasmic domain and reflects the first conformational change ultimately leading to phosphorylation of the enzyme. Stopped-flow fluorescence measurements with the nucleotide analogue eosin show that the dissociation rate constant for eosin is larger in Tris(+) than in Na(+), giving kinetic evidence of the difference in structural effects of Na(+) and Tris(+). According to the recent crystal structure of the E1·AlF4(-)·ADP·3Na(+) form, the coupling between the ion binding sites and the nucleotide side is mediated by, among others, the M5 helix.

Interaction between Na+/K+-pump and Na+/Ca2+-exchanger modulates intercellular communication.

Science.gov (United States)

Matchkov, Vladimir V; Gustafsson, Helena; Rahman, Awahan; Briggs Boedtkjer, Donna M; Gorintin, Sarah; Hansen, Anne Kirstine; Bouzinova, Elena V; Praetorius, Helle A; Aalkjaer, Christian; Nilsson, Holger

2007-04-13

Ouabain, a specific inhibitor of the Na(+)/K(+)-pump, has previously been shown to interfere with intercellular communication. Here we test the hypothesis that the communication between vascular smooth muscle cells is regulated through an interaction between the Na(+)/K(+)-pump and the Na(+)/Ca(2+)-exchanger leading to an increase in the intracellular calcium concentration ([Ca(2+)](i)) in discrete areas near the plasma membrane. [Ca(2+)](i) in smooth muscle cells was imaged in cultured rat aortic smooth muscle cell pairs (A7r5) and in rat mesenteric small artery segments simultaneously with force. In A7r5 coupling between cells was estimated by measuring membrane capacitance. Smooth muscle cells were uncoupled when the Na(+)/K(+)-pump was inhibited either by a low concentration of ouabain, which also caused a localized increase of [Ca(2+)](i) near the membrane, or by ATP depletion. Reduction of Na(+)/K(+)-pump activity by removal of extracellular potassium ([K(+)](o)) also uncoupled cells, but only after inhibition of K(ATP) channels. Inhibition of the Na(+)/Ca(2+)-exchange activity by SEA0400 or by a reduction of the equilibrium potential (making it more negative) also uncoupled the cells. Depletion of intracellular Na(+) and clamping of [Ca(2+)](i) at low concentrations prevented the uncoupling. The experiments suggest that the Na(+)/K(+)-pump may affect gap junction conductivity via localized changes in [Ca(2+)](i) through modulation of Na(+)/Ca(2+)-exchanger activity.

Trypanosomiasis americana en el Perú: III. Importancia del cobayo como reservorio de la enfermedad de Chagas en la región sudoccidental

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Arístides Herrer

1955-12-01

Full Text Available 1. En el Perú, a lo largo de toda la región infestada por el Triatoma infestans, la gente frecuentemente cría cobayos en las mismas habitaciones humanas o en corrales contiguos a éstas. 2. De la estrecha relación existente entre el cobayo y el T. infestans, en lo que concierne a la enfermedad de Chagas el citado roedor adquiere importancia como: a uno de los principales huéspedes del insecto; y b el reservorio más importante del Trypanosoma cruzi. 3. Debido al trasporte del cobayo de unas localidades a otras, deviene también este roedor como activo medio de diseminación del agente etiológico de la enfermedad de Chagas.

Intracellular Na(+) and metabolic modulation of Na/K pump and excitability in the rat suprachiasmatic nucleus neurons.

Science.gov (United States)

Wang, Yi-Chi; Yang, Jyh-Jeen; Huang, Rong-Chi

2012-10-01

Na/K pump activity and metabolic rate are both higher during the day in the suprachiasmatic nucleus (SCN) that houses the circadian clock. Here we investigated the role of intracellular Na(+) and energy metabolism in regulating Na/K pump activity and neuronal excitability. Removal of extracellular K(+) to block the Na/K pump excited SCN neurons to fire at higher rates and return to normal K(+) to reactivate the pump produced rebound hyperpolarization to inhibit firing. In the presence of tetrodotoxin to block the action potentials, both zero K(+)-induced depolarization and rebound hyperpolarization were blocked by the cardiac glycoside strophanthidin. Ratiometric Na(+) imaging with a Na(+)-sensitive fluorescent dye indicated saturating accumulation of intracellular Na(+) in response to pump blockade with zero K(+). The Na(+) ionophore monensin also induced Na(+) loading and hyperpolarized the membrane potential, with the hyperpolarizing effect of monensin abolished in zero Na(+) or by pump blockade. Conversely, Na(+) depletion with Na(+)-free pipette solution depolarized membrane potential but retained residual Na/K pump activity. Cyanide inhibition of oxidative phosphorylation blocked the Na/K pump to depolarize resting potential and increase spontaneous firing in most cells, and to raise intracellular Na(+) levels in all cells. Nonetheless, the Na/K pump was incompletely blocked by cyanide but completely blocked by iodoacetate to inhibit glycolysis, indicating the involvement of both oxidative phosphorylation and glycolysis in fueling the Na/K pump. Together, the results indicate the importance of intracellular Na(+) and energy metabolism in regulating Na/K pump activity as well as neuronal excitability in the SCN neurons.

Synthesis of zeolites Na-A and Na-X from tablet compressed and calcinated coal fly ash

Science.gov (United States)

Hu, Tao; Gao, Wenyan; Liu, Xin; Zhang, Yifu; Meng, Changgong

2017-10-01

Zeolites Na-A and Na-X are important synthetic zeolites widely used for separation and adsorption in industry. It is of great significance to develop energy-efficient routines that can synthesize zeolites Na-A and Na-X from low-cost raw materials. Coal fly ash (CFA) is the major residue from the combustion of coal and biomass containing more than 85% SiO2 and Al2O3, which can readily replace the conventionally used sodium silicate and aluminate for zeolite synthesis. We used Na2CO3 to replace the expensive NaOH used for the calcination of CFA and showed that tablet compression can enhance the contact with Na2CO3 for the activation of CFA through calcination for the synthesis of zeolites Na-A and Na-X under mild conditions. We optimized the control variables for zeolite synthesis and showed that phase-pure zeolite Na-A can be synthesized with CFA at reactant molar ratio, hydrothermal reaction temperature and reaction time of 1.3Na2O: 0.6Al2O3: 1SiO2: 38H2O at 80°C for 6 h, respectively, while phase-pure zeolite Na-X can be synthesized at 2.2Na2O: 0.2Al2O3: 1SiO2: 88H2O at 100°C for 8 h, respectively. The composition, morphology, specific surface area, vibration spectrum and thermogravimetry of synthesized Na-A and Na-X were further characterized.

The CERES / NA45 experiment

CERN Multimedia

Laurent Guiraud

2000-01-01

Ceres is one of the second generation heavy ion experiments at CERN's SPS. It is dedicated to the study of electron-positron pairs in relativistic nuclear collisions. NA45 is one of the seven experiments (NA44, NA45, NA49, NA50, NA52, WA97/NA57 and WA98) involved in CERN's Heavy Ion programme which provided evidence for the existence of a new state of matter, the quark-gluon plasma. In this state, quarks, instead of being bound up into more complex particles such as protons and neutrons, are liberated and roam freely. Theory predicts that this state must have existed at about 10 microseconds after the Big Bang, before the formation of matter as we know it today.

The rapid-onset dystonia parkinsonism mutation D923N of the Na+, K+-ATPase alpha3 isoform disrupts Na+ interaction at the third Na+ site.

Science.gov (United States)

Einholm, Anja Pernille; Toustrup-Jensen, Mads S; Holm, Rikke; Andersen, Jens Peter; Vilsen, Bente

2010-08-20

Rapid-onset dystonia parkinsonism (RDP), a rare neurological disorder, is caused by mutation of the neuron-specific alpha3-isoform of Na(+), K(+)-ATPase. Here, we present the functional consequences of RDP mutation D923N. Relative to the wild type, the mutant exhibits a remarkable approximately 200-fold reduction of Na(+) affinity for activation of phosphorylation from ATP, reflecting a defective interaction of the E(1) form with intracellular Na(+). This is the largest effect on Na(+) affinity reported so far for any Na(+), K(+)-ATPase mutant. D923N also affects the interaction with extracellular Na(+) normally driving the E(1)P to E(2)P conformational transition backward. However, no impairment of K(+) binding was observed for D923N, leading to the conclusion that Asp(923) is specifically associated with the third Na(+) site that is selective toward Na(+). The crystal structure of the Na(+), K(+)-ATPase in E(2) form shows that Asp(923) is located in the cytoplasmic half of transmembrane helix M8 inside a putative transport channel, which is lined by residues from the transmembrane helices M5, M7, M8, and M10 and capped by the C terminus, recently found involved in recognition of the third Na(+) ion. Structural modeling of the E(1) form of Na(+), K(+)-ATPase based on the Ca(2+)-ATPase crystal structure is consistent with the hypothesis that Asp(923) contributes to a site binding the third Na(+) ion. These results in conjunction with our previous findings with other RDP mutants suggest that a selective defect in the handling of Na(+) may be a general feature of the RDP disorder.

Relativización de la importancia de la partitura en la educación musical: unas consecuencias pedagógicas

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Juan Sebastián Ochoa

2016-04-01

Full Text Available El texto plantea una mirada crítica al papel actual de la partitura convencional occidental dentro de la educación musical formal y, propone, a partir de una reflexión sobre el carácter ontológico de la partitura como herramienta de uso descriptivo y prescriptivo (siguiendo la propuesta del musicólogo Charles Seeger, tres consecuencias pedagógicas que se desprenden de relativizar la importancia de la partitura en los tiempos actuales: ampliar la noción de notación musical, privilegiar una educación musical sonoro-corporal, y hacer un uso mayor de las nuevas tecnologías de grabación y reproducción en el aula. La conclusión es que una relativización de la partitura debe llevarnos a una educación musical necesariamente menos racionalizada y más sonoro-corporal, menos leída y más vivida.

As discussões sobre a sustentabilidade na atividade turística: uma analise para o Brasil na ultima década

OpenAIRE

Nathália Roncada de Freitas; Paulo Augusto Ramalho de SOUZA; Elizandra Mariza Zambra; Raquel da Silva Pereira; Maria do Carmo Romeiro

2014-01-01

Debido a la importancia del turismo, como una actividad económica en Brasil, y su efecto sobre el medio ambiente, al que se inserta, se deben entender los debates sobre el tema en los últimos diez años. Este estudio tiene como objetivo general analizar los principales debates relacionados con la sostenibilidad del turismo en Brasil en la última década. Así se estructuró el diseño metodológico exploratorio descriptivo en el que se analizaron los artículos científ...

Recikliranje plastenk na kreativen način

OpenAIRE

Pavlin, Suzana

2017-01-01

Plastenke, poleg ostalih plastičnih izdelkov, v zadnjih letih predstavljajo pravo katastrofo za okolje. Domnevamo, da se le redko kdo vpraša, kaj se zgodi z njo po tem, ko je iz nje zaužil še zadnjo kapljico vode. Plastenka je lahko kot večina ostalih komunalnih odpadkov ponovno uporabljena, reciklirana, sežgana ali odložena na deponijo. V primeru nespoštovanja Zakona o varstvu okolja pa pristane v naravi, pogosto v morju, kjer prav počasi razpada in negativno vpliva na celoten ekosistem. V d...

Plant Defensins NaD1 and NaD2 Induce Different Stress Response Pathways in Fungi

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Peter M. Dracatos

2016-09-01

Full Text Available Nicotiana alata defensins 1 and 2 (NaD1 and NaD2 are plant defensins from the ornamental tobacco that have antifungal activity against a variety of fungal pathogens. Some plant defensins interact with fungal cell wall O-glycosylated proteins. Therefore, we investigated if this was the case for NaD1 and NaD2, by assessing the sensitivity of the three Aspergillus nidulans (An O-mannosyltransferase (pmt knockout (KO mutants (An∆pmtA, An∆pmtB, and An∆pmtC. An∆pmtA was resistant to both defensins, while An∆pmtC was resistant to NaD2 only, suggesting NaD1 and NaD2 are unlikely to have a general interaction with O-linked side chains. Further evidence of this difference in the antifungal mechanism was provided by the dissimilarity of the NaD1 and NaD2 sensitivities of the Fusarium oxysporum f. sp. lycopersici (Fol signalling knockout mutants from the cell wall integrity (CWI and high osmolarity glycerol (HOG mitogen-activated protein kinase (MAPK pathways. HOG pathway mutants were sensitive to both NaD1 and NaD2, while CWI pathway mutants only displayed sensitivity to NaD2.

Glutamate Water Gates in the Ion Binding Pocket of Na(+) Bound Na(+), K(+)-ATPase

DEFF Research Database (Denmark)

Han, Minwoo; Kopec, Wojciech; Solov'yov, Ilia A

2017-01-01

III is always protonated. Glutamic acid residues in the three binding sites act as water gates, and their deprotonation triggers water entry to the binding sites. From DFT calculations of Na(+) binding energies, we conclude that three protons in the binding site are needed to effectively bind Na......The dynamically changing protonation states of the six acidic amino acid residues in the ion binding pocket of the Na(+), K(+) -ATPase (NKA) during the ion transport cycle are proposed to drive ion binding, release and possibly determine Na(+) or K(+) selectivity. We use molecular dynamics (MD......(+) from water and four are needed to release them in the next step. Protonation of Asp926 in site III will induce Na(+) release, and Glu327, Glu954 and Glu779 are all likely to be protonated in the Na(+) bound occluded conformation. Our data provides key insights into the role of protons in the Na...

Importancia de la gestión de proyectos de traducción en las empresas de traducción y en aquellas que requieren de estos servicios

OpenAIRE

Niño Jerónimo, Diana Alexandra; Ramírez Morera, Jhonny Eugenio

2012-01-01

La presente investigación, titulada Importancia de la gestión de proyectos de traducción en las empresas de traducción y en aquellas que requieren de estos servicios, se llevó a cabo con el propósito de destacar la relevancia que tendría incluir un modelo de gestión de proyectos de traducción en los procesos actuales que desarrollan las empresas, ubicadas en Bogotá, dedicadas a este oficio y aquellas que requieren de dichos servicios (debido a su posición en el mercado). En el proceso de ...

Narrativa y ciencia. La importancia de las palabras en la investigación

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Yolanda M. Guerra García

2012-01-01

Full Text Available El artículo analiza la importancia de saber narrar la ciencia de manera idónea y brinda algunos lineamientos para hacerlo. En un siglo invadido por la tecnología, donde el universo se encuentra al alcance de la mano con solamente un clic en Google o en cualquier otro buscador, pareciera como si cada vez más nos alejáramos de la necesidad de producir conocimiento nuevo, de pensar, repensar y de las técnicas de escribir esos pensamientos en un texto agradable de ser leído. Afortunadamente, hay excepciones frente a la era de copiar y pegar, y todavía se encuentran personas que logran escribir hermosamente, reflejando incluso en sus narraciones los hallazgos de su ciencia. En Colombia, ha comenzado la cultura de la investigación y de los cursos de tercer nivel; la que, vale aclarar, lleva siglos en otros países 1 . Este auge de investigación ha traído consigo la inmensa necesidad de escribir; no hay institución universitaria ni docente que se respete que no haga o deba hacer investigación y, a su vez, convertirse en multiplicador con los estudiantes, de la necesidad de escribir, investigar y de hacerlo apropiadamente. Allí es cuando el tema de la narrativa y la ciencia toma la mayor relevancia. Escribir, por paradójico que parezca, tiene su ciencia. ¿Cómo debe entonces narrarse la ciencia? ¿Es realmente fácil escribir? ¿Hay secretos? ¿Cuál debe ser la estructura de un texto científico? Esto es lo que se investiga y presenta en este artículo, que pretende ser un punto de partida más que de llegada al apasionante mundo de la narrativa y la ciencia.

NA62 and NA48/2 results on search for Heavy Neutral Leptons

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Lamanna Gianluca

2018-01-01

Full Text Available In this paper we present new results on upper limits for the search of Heavy Neutral Leptons (HNL with data collected by NA48/2 (2003-2004, NA62-RK (2007 and NA62 (2015 CERN experiments. The data collected with different trigger configuration allow to search for both long and short living heavy neutrinos in the mass range below the kaon mass. In addition the status of the search for K+ → π+vv with the NA62 detector will be briefly presented.

RELACIÓN ENTRE IMPORTANCIA ATRIBUIDA A LA RSC, JERARQUÍA DE VALORES Y ORIENTACIÓN SOCIAL EN DIRECTIVOS Y ACADÉMICOS DE UNA UNIVERSIDAD CHILENA / RELATIONSHIP BETWEEN EMPHASIS ON CSR, HIERARCHY OF VALUES AND SOCIAL ORIENTATION IN MANAGERS AND ACADEMICS IN A CHILEAN UNIVERSITY

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Gracia Navarro Saldaña*

2011-02-01

Full Text Available RESUMENEl presente estudio adapta el modelo de la Responsabilidad Social Corporativa (RSC a la organización universitaria.Busca describir la importancia atribuida a la incorporación de la RSC a la gestión universitaria e identificar la relación entreesta variable y dos características personales relevantes, en directivos y académicos de la Universidad de Concepción(Chile: Jerarquía de valores y orientación social. Se encuestó a 43 directivos y 48 académicos con el cuestionario deImportancia Atribuida a la RSC; el Inventario de Valores de Schwartz y la Encuesta de Orientación Social de Triandis yGelfand. Los resultados muestran alta atribución de importancia a la RSC en la gestión universitaria; alta adhesión a tiposvalóricos de universalismo, benevolencia y autonomía y alta presencia de las orientaciones sociales colectivistas. Existerelación positiva significativa de la atribución de importancia a la RSC con los tipos valóricos de universalismo y benevolenciay negativa con poder y con orientación social individualista vertical.ABSTRACTThis study tries to adapt the model of CSR to the university organization. It describes the importance attributed to theincorporation of CSR to university management and identifies the relationship between this variable and two relevantpersonal characteristics in managers and academics from the University of Concepción (Chile: Hierarchy of values andsocial orientation. We surveyed 43 managers and 48 academics with the Emphasis on the RSC Questionnaire, the SchwartzValues Inventory and the Social Guidance Survey of Triandis and Gelfand. The results show high importance assigned tothe RSC in university management, high adhesion to value types of universalism, benevolence and autonomy and a highpresence of collectivistic social orientations. There is significant positive relationship of attribution of importance to theRSC with the value types of universalism and benevolence and negative

Importancia biotecnológica de la microbiodiversidad. Los nuevos cazadores de microbios

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Judith Piñero Bonilla

2013-12-01

Full Text Available El objetivo de este trabajo está orientado a destacar la importancia biotecnológica de los microorganismos con especial referencia al área alimentaria y agrícola, en el contexto histórico y latinoamericano. Los microorganismos han sido recursos valiosos para la humanidad desde que el hombre comenzó a producir sus alimentos artesanalmente incorporando los procesos fermentativos para la transformación de las materias primas o consumiéndolos directamente. Ya en el siglo XIX, con la ayuda del microscopio se empiezan a entender los principios que rigen estos bioprocesos y los estudios posteriores permitieron determinar la utilidad de los microorganismos y su potencial económico para la producción de insumos comercializables, lo que condujo al desarrollo de la microbiología industrial, la base de la biotecnología, la cual se ha ido fortaleciendo con el uso de las herramientas de la ingeniería genética y de las técnicas de la biología molecular con las que se ha podido detectar e identificar una gran variedad de microorganismos incluso de ambientes extremos en los que los métodos de cultivo convencionales han fallado. El potencial encontrado en la microbiodiversidad es parte de una importante actividad científica conocida como bioprospección, para seleccionar los microorganismos con características que le confieran valor comercial. De esta manera, la búsqueda se ha dirigido principalmente hacia los organismos productores de insumos agrícolas, farmacológicos y alimentarios así como su aplicación en actividades de biorremediación. En este sentido, los microorganismos representan un aporte significativo para la ciencia y la economía de los países latinoamericanos, por lo que algunos de ellos y según sus necesidades, han desarrollado líneas de investigación en bioprospección microbiana como parte de las políticas en materia de ciencia y tecnología.

Transmural gradients in Na/K pump activity and [Na+]I in canine ventricle.

Science.gov (United States)

Gao, J; Wang, W; Cohen, I S; Mathias, R T

2005-09-01

There are well-documented differences in ion channel activity and action potential shape between epicardial (EPI), midmyocardial (MID), and endocardial (ENDO) ventricular myocytes. The purpose of this study was to determine if differences exist in Na/K pump activity. The whole cell patch-clamp was used to measure Na/K pump current (I(P)) and inward background Na(+)-current (I(inb)) in cells isolated from canine left ventricle. All currents were normalized to membrane capacitance. I(P) was measured as the current blocked by a saturating concentration of dihydro-ouabain. [Na(+)](i) was measured using SBFI-AM. I(P)(ENDO) (0.34 +/- 0.04 pA/pF, n = 17) was smaller than I(P)(EPI) (0.68 +/- 0.09 pA/pF, n = 38); the ratio was 0.50 with I(P)(MID) being intermediate (0.53 +/- 0.13 pA/pF, n = 19). The dependence of I(P) on [Na(+)](i) or voltage was essentially identical in EPI and ENDO (half-maximal activation at 9-10 mM [Na(+)](i) or approximately -90 mV). Increasing [K(+)](o) from 5.4 to 15 mM caused both I(P)(ENDO) and I(P)(EPI) to increase, but the ratio remained approximately 0.5. I(inb) in EPI and ENDO were nearly identical ( approximately 0.6 pA/pF). Physiological [Na(+)](i) was lower in EPI (7 +/- 2 mM, n = 31) than ENDO (12 +/- 3 mM, n = 29), with MID being intermediate (9 +/- 3 mM, n = 22). When cells were paced at 2 Hz, [Na(+)](i) increased but the differences persisted (ENDO 14 +/- 3 mM, n = 10; EPI 9 +/- 2 mM, n = 10; and MID intermediate, 11 +/- 2 mM, n = 9). Based on these results, the larger I(P) in EPI appears to reflect a higher maximum turnover rate, which implies either a larger number of active pumps or a higher turnover rate per pump protein. The transmural gradient in [Na(+)](i) means physiological I(P) is approximately uniform across the ventricular wall, whereas transporters that utilize the transmembrane electrochemical gradient for Na(+), such as Na/Ca exchange, have a larger driving force in EPI than ENDO.

Reactions of metal oxides with molten NaPO3 + NaCl mixtures

International Nuclear Information System (INIS)

Kovarskaya, E.N.; Mityakhina, V.S.; Rodionov, Yu.I.; Silin, M.Yu.

1988-01-01

We consider the dissolution mechanism for iron (III), europium(III), and tin(IV) oxides in molten NaPO 3 + NaCl that are responsible for the peak solubilities. We chose Fe 2 O 3 as the basic material since this occurs in large amounts around damaged metal structures in rock salt mines in a proposed zone for storing vitrified radioactive wastes. Solubility measurement and paper chromatography show that Fe 2 O 3 dissolves in molten NaPO 3 + NaCl in air by reaction with the solvent to give double iron and sodium diphosphates and monophosphates in accordance with the initial solution-in-the-melt composition, the degree of equilibration, and the temperature. The elevated solubilities for initial NaCl contents close to 30 mole % are due to sodium triphosphates and tricyclophosphates present in these melts. Moessbauer spectroscopy confirms that double iron, europium and tin diphosphates and monophosphates containing sodium occur in these chloride-polyphosphate melts

Na(+),K (+)-ATPase as a docking station: protein-protein complexes of the Na(+),K (+)-ATPase.

Science.gov (United States)

Reinhard, Linda; Tidow, Henning; Clausen, Michael J; Nissen, Poul

2013-01-01

The Na(+),K(+)-ATPase, or sodium pump, is well known for its role in ion transport across the plasma membrane of animal cells. It carries out the transport of Na(+) ions out of the cell and of K(+) ions into the cell and thus maintains electrolyte and fluid balance. In addition to the fundamental ion-pumping function of the Na(+),K(+)-ATPase, recent work has suggested additional roles for Na(+),K(+)-ATPase in signal transduction and biomembrane structure. Several signaling pathways have been found to involve Na(+),K(+)-ATPase, which serves as a docking station for a fast-growing number of protein interaction partners. In this review, we focus on Na(+),K(+)-ATPase as a signal transducer, but also briefly discuss other Na(+),K(+)-ATPase protein-protein interactions, providing a comprehensive overview of the diverse signaling functions ascribed to this well-known enzyme.

Characterization of Na+-linked and Na+-independent Cl-/HCO3- exchange systems in Chinese hamster lung fibroblasts

International Nuclear Information System (INIS)

Cassel, D.; Scharf, O.; Rotman, M.; Cragoe, E.J. Jr.; Katz, M.

1988-01-01

The PS120 variant of Chinese hamster lung fibroblasts which lacks Na + /H + exchange activity was used to investigate bicarbonate transport systems and their role in intracellular pH (pH/sub i/) regulation. When pH/sub i/ was decreased by acid load, bicarbonate caused pH/sub i/ increase and stimulated 36 Cl - efflux from the cells, both in a Na + -dependent manner. These results together with previous findings that bicarbonate stimulates 22 Na + uptake in PS120 cells demonstrate the presence of a Na + -linked Cl - /HCO 3 - exchange system. In cells with normal initial pH/sub i/, bicarbonate caused Na + -independent pH/sub i/ increase in Cl - -free solutions and stimulated Na + -independent 36 Cl - efflux, indicating that a Na + -independent Cl - /HCO 3 - exchanger is also present in the cell. Na + -linked and Na + -independent Cl - /HCO 3- exchange is apparently mediated by two distinct systems, since a [(tetrahydrofluorene-7-yl)oxy]acetic acid derivative selectively inhibits the Na + -independent exchanger. An additional distinctive features is a 10-fold lower affinity for chloride of the Na + -linked exchanger. The Na + -linked and Na + -independent Cl - /HCO 3 - exchange systems are likely to protect the cell from acid and alkaline load, respectively

Identificación de especies de anopheles de importancia médica en el departamento de Sucre, Colombia

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Gladis Pérez Rodríguez

2014-05-01

Full Text Available En Colombia los mosquitos Anopheles, subgénero Nyssorhynchus tiene una gran importancia en medicina tropical ya que este subgénero contiene la mayoría de las especies vectoras de la malaria encontradas en el país. El departamento de Sucre, localizado al norte de Colombia, presenta condiciones bioclimáticas que favorecen el desarrollo de insectos pertenecientes al subgénero Nyssorhynchus; sin embargo, el conocimiento sobre este es escaso. Con el objetivo de verificar la presencia de especies del subgénero en dos subregiones del departamento de Sucre (La Sabana y Golfo de Morrosquillo, se realizó un inventario de mosquitos Anopheles, utilizando para su captura cebo humano. Para la identificación de las especies se utilizaron claves taxonómicas. Se coleccionaron un total de 221 especimenes pertenecientes a cinco especies del subgénero Nyssorhynchus: A. albimanus, A. triannulatus, A. marajoara, A. pseudopunctipennis y A. nunestovari de las cuales dos son consideradas como vectores principales de la malaria (A. albimanus y A. nunestovari y una como vector secundario (A. pseudopunctipennis. (Duazary 2006; 2:104-109

Na/K Pump and Beyond: Na/K-ATPase as a Modulator of Apoptosis and Autophagy

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Cassiano Felippe Gonçalves-de-Albuquerque

2017-04-01

Full Text Available Lung cancer is a leading cause of global cancer deaths. Na/K-ATPase has been studied as a target for cancer treatment. Cardiotonic steroids (CS trigger intracellular signalling upon binding to Na/K-ATPase. Normal lung and tumour cells frequently express different pump isoforms. Thus, Na/K-ATPase is a powerful target for lung cancer treatment. Drugs targeting Na/K-ATPase may induce apoptosis and autophagy in transformed cells. We argue that Na/K-ATPase has a role as a potential target in chemotherapy in lung cancer treatment. We discuss the effects of Na/K-ATPase ligands and molecular pathways inducing deleterious effects on lung cancer cells, especially those leading to apoptosis and autophagy.

Na/K Pump and Beyond: Na/K-ATPase as a Modulator of Apoptosis and Autophagy.

Science.gov (United States)

Felippe Gonçalves-de-Albuquerque, Cassiano; Ribeiro Silva, Adriana; Ignácio da Silva, Camila; Caire Castro-Faria-Neto, Hugo; Burth, Patrícia

2017-04-21

Lung cancer is a leading cause of global cancer deaths. Na/K-ATPase has been studied as a target for cancer treatment. Cardiotonic steroids (CS) trigger intracellular signalling upon binding to Na/K-ATPase. Normal lung and tumour cells frequently express different pump isoforms. Thus, Na/K-ATPase is a powerful target for lung cancer treatment. Drugs targeting Na/K-ATPase may induce apoptosis and autophagy in transformed cells. We argue that Na/K-ATPase has a role as a potential target in chemotherapy in lung cancer treatment. We discuss the effects of Na/K-ATPase ligands and molecular pathways inducing deleterious effects on lung cancer cells, especially those leading to apoptosis and autophagy.

Alimentación del pez insectívoro neotropical Creagrutus bolivari (Pisces: Characidae según los métodos gráfico y de importancia relativa

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Mario Ortaz

2006-12-01

Full Text Available Se estudió la alimentación de un pez neotropical (Creagrutus bolivari usando diferentes métodos: el método gráfico de Cortés (1997 y dos índices de importancia relativa (George y Hadley, 1979 (% RIi y Cortés, 1997 (% IRIi. Sólo las presas discretas (invertebrados acuáticos y terrestres se emplearon en el análisis de dieta. Se estimó ara cada ítem, las frecuencias de aparición (% A, numérica (% N y gravimétrica (% G. Se analizó un total de 240 ejemplares (intervalo de talla desde 25.3 hasta 64.7 mm de longitud estándar. Para valores de % A > 50 %, el % IRIi resultó mayor al obtenido para el % RIi, con una tendencia opuesta (hasta 130 veces para valores de % A por debajo del 50 %. El % IRIi sobreestimó la importancia relativa de las presas para valores altos de % A, mientras que subestimó la importancia relativa de las presas para valores bajos de % A y mostró un comportamiento no lineal a medida que varió el % A. Las variables empleadas en el método gráfico de Cortés son insuficientes para evaluar la estrategia alimentaria del depredador (generalismo-especialismo. De este modo, se sugiere incluir otras variables como el ancho de nicho trófico poblacional e individual así como un adecuado registro de campo. Es necesario un amplio registro de campo para clasificar a las presas como escasa o dominante de acuerdo a la clasificación de Cortés. Los índices compuestos que incluyen las variables: masa, número y aparición proporcionan una descripción más precisa de la dieta y permiten realizar estudios comparativos. El análisis gráfico es fácil de interpretar y ayuda a evaluar aspectos como la importancia de la presa y la estrategia alimentaria del depredadorThe diet of the neotropical insectivorous fish Creagrutus bolivari (Pisces: Characidae according to the "graphic" and "relative importance" methods. The diet of a neotropical fish species (Creagrutus bolivari was studied using different methods: the Cortés 1997

Subnitride chemistry: A first-principles study of the NaBa3N, Na5Ba3N, and Na16Ba6N phases

International Nuclear Information System (INIS)

Oliva, Josep M.

2005-01-01

An ab initio study on the electronic structure of the subnitrides NaBa 3 N, Na 5 Ba 3 N, and Na 16 Ba 6 N is performed for the first time. The NaBa 3 N and Na 5 Ba 3 N phases consist of infinite 1 ∞ [NBa 6/2 ] strands composed of face-sharing NBa 6 octahedra surrounded by a 'sea' of sodium atoms. The Na 16 Ba 6 N phase consist of discrete [NBa 6 ] octahedra arranged in a body-cubic fashion, surrounded by a 'sea' of sodium atoms. Our calculations suggest that the title subnitrides are metals. Analysis of the electronic structure shows partial interaction of N(2s) with Ba(5p) electrons in the lower energy region for NaBa 3 N and Na 5 Ba 3 N. However, no dispersion is observed for the N(2s) and Ba(5p) bands in the cubic phase Na 16 Ba 6 N. The metallic band below the Fermi level shows a strong mixing of N(2p), Ba(6s), Ba(5d), Ba(6p), Na(3s) and Na(3p) orbitals. The metallic character in these nitrides stems from delocalized electrons corresponding to hybridized 5d l 6s m 6p n barium orbitals which interact with hybridized 3s n 3p m sodium orbitals. Analysis of the electron density and electronic structure in these nitrides shows two different regions: a metallic matrix corresponding to the sodium atoms and the regions around them and heteropolar bonding between nitrogen and barium within the infinite 1 ∞ [NBa 6/2 ] strands of the NaBa 3 N and Na 5 Ba 3 N phases, and within the isolated [NBa 6 ] octahedra of the Na 16 Ba 6 N phase. The nitrogen atoms inside the strands and octahedra are negatively charged, the anionic character of nitrogens being larger in the isolated octahedra of the cubic phase Na 16 Ba 6 N, due to the lack of electron delocalization along one direction as opposed to the other phases. The sodium and barium atoms appear to be slightly negatively and positively charged, the latter to a larger extent. From the computed Ba-N overlap populations as well as the analysis of the contour maps of differences between total density and superposition of

WPŁYW WIEKU NA WYTRZYMAŁOŚĆ NA ŚCISKANIE BETONU MODYFIKOWANEGO DODATKIEM METAKAOLINITU

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Janusz KONKOL

Full Text Available W artykule przedstawiono wyniki badań wytrzymałości na ściskanie betonów modyfikowanych dodatkiem metakaolinitu po 2, 3, 7, 14, 28 i 56 dniach dojrzewania. Dodatek metakaolinitu użyto jako częściowy substytut cementu, dokonując wymiany 10% masy cementu na metakaolinit. Udział ten uznawany jest za optymalny z uwagi na inne niż wytrzymałość na ściskanie właściwości betonu, w tym trwałość betonu modyfikowanego metakaolinitem. Badania przeprowadzono także dla betonu tła, betonu bez dodatku metakaolinitu. Betony wykonano przy założeniu stałego stosunku woda/spoiwo, względnie woda/cement wynoszącego 0,45 oraz przy użyciu cementu portlandzkiego CEM I 32,5R, piasku kwarcowego frakcji do 2 mm oraz grysu bazaltowego frakcji do 16 mm. W celu uzyskania pożądanej konsystencji mieszanki betonowej zastosowano upłynniacz na bazie estrów polikarboksylowych. Uzyskane rezultaty badań potwierdziły wysoką aktywność pucolanową metakaolinitu już we wczesnym okresie dojrzewania betonu. W okresie między 3 a 7 dniem dojrzewania stwierdzono wolniejszy przyrost wytrzymałości na ściskanie w betonie niemodyfikowanym metakaolinitem, podczas gdy w betonie, w którym 10% masy cementu zastąpiono metakaolinitem uwidocznił się znaczący przyrost wytrzymałości na ściskanie. Po 2 dniach dojrzewania wytrzymałość na ściskanie betonu tła była nieznacznie wyższa od wytrzymałości na ściskanie betonu modyfikowanego. Korzystny wpływ dodatku metakaolinitu wynikający z jego wysokiej aktywności pucolanowej, jak również z uszczelniającego charakteru tego dodatku obserwowano jest zwłaszcza w okresie między 3 a 14 dniem dojrzewania. W tym okresie obserwowano znaczny przyrost wytrzymałości na ściskanie betonu modyfikowanego w porównaniu z wytrzymałością na ściskanie betonu tła. Po 7 i 14 dniach dojrzewania stwierdzono odpowiednio prawie 25% i 21% wzrost wytrzymałości na ściskanie na skutek użycia metakaolinitu.

Educacao interprofissional: formacao de profissionais de saude para o trabalho em equipe com foco nos usuarios

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Marina Peduzzi

2013-08-01

Full Text Available São analisados os constructos teóricos da educação interprofissional com base em duas revisões de literatura, considerado o contexto da formação dos profissionais de saúde no Brasil. Identificam-se três tipos de formação: uniprofissional, multiprofissional e interprofissional, com predomínio da primeira, que ocorre entre estudantes de uma mesma profissão de forma isolada; a segunda, entre estudantes de duas ou mais profissões de forma paralela, sem haver interação, e na terceira há aprendizagem compartilhada, com interação entre estudantes e/ou profissionais de diferentes áreas. Destaca-se a distinção entre interprofissionalidade e interdisciplinaridade, referidas, respectivamente, como a integração das práticas profissionais e das disciplinas ou áreas de conhecimento. Mediante a análise apresentada, conclui-se que no contexto brasileiro, a educação interprofissional, base para o trabalho em equipe colaborativo, ainda está restrita a iniciativas recentes, que merecem estudo.

Teratological studies of DTPA-CaNa3, DTPA-ZnNa3 and quinamic acid in mice

International Nuclear Information System (INIS)

Luo Meichu; Ruan Tianming; Tong Shungao

1989-01-01

DTPA-CaNa 3 , DTPA-ZnNa 3 and quinamic acid are effective chelating agents for removing actinide elements from the body. In this experiment, different doses of DTPA-CaNa 3 , DTPA-ZnNa 3 and quinamic acid were given to mice on gestation days 6-10. Eight groups of mice received 0.8 and 2.0 mM/kg of DTPA-CaNa 3 , 3.8, 7.6, and 11.4 mM/kg of DTPA-ZnNa 3 and 0.42, 2.1, and 4.2 mM/kg of quinamic acid. Hypetonic saline and isotonic saline were given to two control groups. DTPA-CaNa 3 and quinamidic acid were found to be much more toxic to fetus of mice than DTPA-ZnNa 3 . When the doses of DTPA-CaMa 3 and quinamidic acid were 20 times higher than the human dose, the number of resorbed fetus was increased and the number and weight of live fetus were reduced. The result of injection with 7.6 mM/kg (200 times of human dose)DTPA-ZnNa 3 and that of injection with isotonic saline are the same. Therefore, we suggest that the DTPA-CaNa 3 and quinamidic acid should not be given to pregnant woman, if chelation therapy is needed, while the much safer DTPA-ZnNa 3 could be used

Na-ion dynamics in Quasi-1D compound NaV2O4

International Nuclear Information System (INIS)

Månsson, M; Umegaki, I; Nozaki, H; Higuchi, Y; Sugiyama, J; Kawasaki, I; Watanabe, I; Sakurai, H

2014-01-01

We have used the pulsed muon source at ISIS to study high-temperature Na-ion dynamics in the quasi-one-dimensional (Q1D) metallic antiferromagnet NaV 2 O 4 . By performing systematic zero-field and longitudinal-field measurements as a function of temperature we clearly distinguish that the hopping rate increases exponentially above T diff ≈ 250 K. The data is well fitted to an Arrhenius type equation typical for a diffusion process, showing that the Na-ions starts to be mobile above T diff . Such results make this compound very interesting for the tuning of Q1D magnetism using atomic-scale ion-texturing through the periodic potential from ordered Na-vacancies. Further, it also opens the door to possible use of NaV 2 O 4 and related compounds in energy related applications

O Passeio Público do Rio de Janeiro na Literatura, na Pintura e na Fotografia do Século XIX

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Solange de Aragão

2012-06-01

Full Text Available Este artigo tem como objetivo geral e mais amplo chamar a atenção dos pesquisadores para a importância da literatura, da pintura e da fotografia como fontes documentais para a construção da História do Paisagismo no Brasil por meio de um estudo de caso muito particular: o Passeio Público do Rio de Janeiro no século XIX. São objetivos específicos apresentar e analisar o modo como esse espaço livre público aparece na literatura, na pintura e na fotografia desse período, considerando suas transformações paisagísticas.

Solubility of NaNd(CO3)2.6H2O(c) in concentrated Na2CO3 and NaHCO3 solutions

International Nuclear Information System (INIS)

Rao, L.; Rai, D.; Felmy, A.R.; Fulton, R.W.; Novak, C.F.

1996-01-01

NaNd(CO 3 ) 2 x 6 H 2 O(c) was identified to be the final equilibrium solid phase in suspensions containing concentrated sodium carbonate (0.1 to 2.0 M) and sodium bicarbonate (0.1 to 1.0 M), with either NaNd(CO 3 ) 2 x 6 H 2 O(c) or Nd 2 (CO 3 ) 3 x xH 2 O(s) as initial solids. A thermodynamic model, based on Pitzer's specific into-interaction approach, was developed to interpret the solubility of NaNd(CO 3 ) 2 x 6 H 2 O(c) as functions of sodium carbonate and sodium bicarbonate concentrations. In this model, the solubility data of NaNd(CO 3 ) 2 x 6 H 2 O(c) were explained by assuming the formation of NdCO 3 + , Nd(CO 3 ) 2 - and Nd(CO 3 ) 3 3- species and invoking the specific ion interactions between Na + and Nd(CO 3 ) 3 3- . Ion interaction parameters for Na + -Nd(CO 3 ) 3 3- were developed to fit the solubility data. Based on the model calculations, Nd(CO 3 ) 3 3- was the predominant aqueous neodymium species in 0.1 to 2 M sodium carbonate and 0.1 to 1 M sodium bicarbonate solutions. The logarithm of the NaNd(CO 3 ) 2 x 6 H 2 O solubility product (NaNd(CO 3 ) 2 x 6 H 2 O(c)=Na + +Nd 3+ +2 CO 3 2- +6 H 2 O) was calculated to be -21.39. This model also provided satisfactory interpretation of the solubility data of the analogous Am(III) system in less concentrated carbonate and bicarbonate solutions. (orig.)

Application of gamma irradiation on forming protein-based edible films; Aplicacao da irradiacao na formacao de filmes comestiveis proteicos

Energy Technology Data Exchange (ETDEWEB)

Sabato, Susy Frey

2000-07-01

In the last decade considerable interest has been addressed to the development of protein-based edible films due to their application in the food industry, as a substitute to traditional plastic films. The use of soy and whey proteins to form those films has been investigated, using heat, chemical and enzymatic processes. Gamma irradiation was recently reported to form caseinate-based edible films, due to the increase of the cohesive strength of the proteins by the formation of cross-links. This work aimed to verify the role of the gamma irradiation in the process of forming edible films from soy protein isolate (SPI) alone and in complex mixtures, that is, mixed with whey protein isolate (WPI), with carbethoxymethyl cellulose (CMC) and with poly(vinyl)alcohol (PVA). Gamma irradiation treatment improved significantly the mechanical properties for all films. The mechanical behavior is strongly related to the formulation, showing synergy between the gamma irradiation and the CMC, mainly for SPI-based films. SPI-based films presented a trend to decrease the water vapor permeability values when irradiated. The CMC addition showed significant improvements on the permeability for films from SPI and from the mixture of SPI with WPI. (author)

Mechanism of μ-conotoxin PIIIA binding to the voltage-gated Na+ channel NaV1.4.

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Rong Chen

Full Text Available Several subtypes of voltage-gated Na+ (NaV channels are important targets for pain management. μ-Conotoxins isolated from venoms of cone snails are potent and specific blockers of different NaV channel isoforms. The inhibitory effect of μ-conotoxins on NaV channels has been examined extensively, but the mechanism of toxin specificity has not been understood in detail. Here the known structure of μ-conotoxin PIIIA and a model of the skeletal muscle channel NaV1.4 are used to elucidate elements that contribute to the structural basis of μ-conotoxin binding and specificity. The model of NaV1.4 is constructed based on the crystal structure of the bacterial NaV channel, NaVAb. Six different binding modes, in which the side chain of each of the basic residues carried by the toxin protrudes into the selectivity filter of NaV1.4, are examined in atomic detail using molecular dynamics simulations with explicit solvent. The dissociation constants (Kd computed for two selected binding modes in which Lys9 or Arg14 from the toxin protrudes into the filter of the channel are within 2 fold; both values in close proximity to those determined from dose response data for the block of NaV currents. To explore the mechanism of PIIIA specificity, a double mutant of NaV1.4 mimicking NaV channels resistant to μ-conotoxins and tetrodotoxin is constructed and the binding of PIIIA to this mutant channel examined. The double mutation causes the affinity of PIIIA to reduce by two orders of magnitude.

Muscle K+, Na+, and Cl- disturbances and Na+-K+ pump inactivation: implications for fatigue

DEFF Research Database (Denmark)

McKenna, Michael J; Bangsbo, Jens; Renaud, Jean-Marc

2008-01-01

(+)-ATPase activity during exercise stabilizes Na(+) and K(+) concentration gradients and membrane excitability and thus protects against fatigue. However, during intense contraction some Na(+)-K(+) pumps are inactivated and together with further ionic disturbances, likely precipitate muscle fatigue.......Membrane excitability is a critical regulatory step in skeletal muscle contraction and is modulated by local ionic concentrations, conductances, ion transporter activities, temperature, and humoral factors. Intense fatiguing contractions induce cellular K(+) efflux and Na(+) and Cl(-) influx......, causing pronounced perturbations in extracellular (interstitial) and intracellular K(+) and Na(+) concentrations. Muscle interstitial K(+) concentration may increase 1- to 2-fold to 11-13 mM and intracellular K(+) concentration fall by 1.3- to 1.7-fold; interstitial Na(+) concentration may decline by 10 m...

Route, mechanism, and implications of proton import during Na+/K+ exchange by native Na+/K+-ATPase pumps

Science.gov (United States)

Vedovato, Natascia

2014-01-01

A single Na+/K+-ATPase pumps three Na+ outwards and two K+ inwards by alternately exposing ion-binding sites to opposite sides of the membrane in a conformational sequence coupled to pump autophosphorylation from ATP and auto-dephosphorylation. The larger flow of Na+ than K+ generates outward current across the cell membrane. Less well understood is the ability of Na+/K+ pumps to generate an inward current of protons. Originally noted in pumps deprived of external K+ and Na+ ions, as inward current at negative membrane potentials that becomes amplified when external pH is lowered, this proton current is generally viewed as an artifact of those unnatural conditions. We demonstrate here that this inward current also flows at physiological K+ and Na+ concentrations. We show that protons exploit ready reversibility of conformational changes associated with extracellular Na+ release from phosphorylated Na+/K+ pumps. Reversal of a subset of these transitions allows an extracellular proton to bind an acidic side chain and to be subsequently released to the cytoplasm. This back-step of phosphorylated Na+/K+ pumps that enables proton import is not required for completion of the 3 Na+/2 K+ transport cycle. However, the back-step occurs readily during Na+/K+ transport when external K+ ion binding and occlusion are delayed, and it occurs more frequently when lowered extracellular pH raises the probability of protonation of the externally accessible carboxylate side chain. The proton route passes through the Na+-selective binding site III and is distinct from the principal pathway traversed by the majority of transported Na+ and K+ ions that passes through binding site II. The inferred occurrence of Na+/K+ exchange and H+ import during the same conformational cycle of a single molecule identifies the Na+/K+ pump as a hybrid transporter. Whether Na+/K+ pump–mediated proton inflow may have any physiological or pathophysiological significance remains to be clarified. PMID

Route, mechanism, and implications of proton import during Na+/K+ exchange by native Na+/K+-ATPase pumps.

Science.gov (United States)

Vedovato, Natascia; Gadsby, David C

2014-04-01

A single Na(+)/K(+)-ATPase pumps three Na(+) outwards and two K(+) inwards by alternately exposing ion-binding sites to opposite sides of the membrane in a conformational sequence coupled to pump autophosphorylation from ATP and auto-dephosphorylation. The larger flow of Na(+) than K(+) generates outward current across the cell membrane. Less well understood is the ability of Na(+)/K(+) pumps to generate an inward current of protons. Originally noted in pumps deprived of external K(+) and Na(+) ions, as inward current at negative membrane potentials that becomes amplified when external pH is lowered, this proton current is generally viewed as an artifact of those unnatural conditions. We demonstrate here that this inward current also flows at physiological K(+) and Na(+) concentrations. We show that protons exploit ready reversibility of conformational changes associated with extracellular Na(+) release from phosphorylated Na(+)/K(+) pumps. Reversal of a subset of these transitions allows an extracellular proton to bind an acidic side chain and to be subsequently released to the cytoplasm. This back-step of phosphorylated Na(+)/K(+) pumps that enables proton import is not required for completion of the 3 Na(+)/2 K(+) transport cycle. However, the back-step occurs readily during Na(+)/K(+) transport when external K(+) ion binding and occlusion are delayed, and it occurs more frequently when lowered extracellular pH raises the probability of protonation of the externally accessible carboxylate side chain. The proton route passes through the Na(+)-selective binding site III and is distinct from the principal pathway traversed by the majority of transported Na(+) and K(+) ions that passes through binding site II. The inferred occurrence of Na(+)/K(+) exchange and H(+) import during the same conformational cycle of a single molecule identifies the Na(+)/K(+) pump as a hybrid transporter. Whether Na(+)/K(+) pump-mediated proton inflow may have any physiological or

Growth mechanism of NaClO 3 and NaBrO 3 crystals from aqueous ...

Indian Academy of Sciences (India)

A study of growth rates of NaClO3 and NaBrO3 has been carried out using a small growth cell by in situ observation. Normal growth rates of {100} faces of NaClO3 and {111} faces of NaBrO3 along ⟨ 110 ⟩ direction are measured under relatively high supersaturation ranging from 3–8%. In the initial stages of growth, {100}, ...

Rescue of Na+ affinity in aspartate 928 mutants of Na+,K+-ATPase by secondary mutation of glutamate 314.

Science.gov (United States)

Holm, Rikke; Einholm, Anja P; Andersen, Jens P; Vilsen, Bente

2015-04-10

The Na(+),K(+)-ATPase binds Na(+) at three transport sites denoted I, II, and III, of which site III is Na(+)-specific and suggested to be the first occupied in the cooperative binding process activating phosphorylation from ATP. Here we demonstrate that the asparagine substitution of the aspartate associated with site III found in patients with rapid-onset dystonia parkinsonism or alternating hemiplegia of childhood causes a dramatic reduction of Na(+) affinity in the α1-, α2-, and α3-isoforms of Na(+),K(+)-ATPase, whereas other substitutions of this aspartate are much less disruptive. This is likely due to interference by the amide function of the asparagine side chain with Na(+)-coordinating residues in site III. Remarkably, the Na(+) affinity of site III aspartate to asparagine and alanine mutants is rescued by second-site mutation of a glutamate in the extracellular part of the fourth transmembrane helix, distant to site III. This gain-of-function mutation works without recovery of the lost cooperativity and selectivity of Na(+) binding and does not affect the E1-E2 conformational equilibrium or the maximum phosphorylation rate. Hence, the rescue of Na(+) affinity is likely intrinsic to the Na(+) binding pocket, and the underlying mechanism could be a tightening of Na(+) binding at Na(+) site II, possibly via movement of transmembrane helix four. The second-site mutation also improves Na(+),K(+) pump function in intact cells. Rescue of Na(+) affinity and Na(+) and K(+) transport by second-site mutation is unique in the history of Na(+),K(+)-ATPase and points to new possibilities for treatment of neurological patients carrying Na(+),K(+)-ATPase mutations. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Métodos cromatográficos para determinar aminas biogênicas em alimentos de origem animal

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César Aquiles Lázaro de la Torre

2013-12-01

Full Text Available Aminas biogenicas sao formadas como resultado da descarboxilacao de aminoacidos livres especificos. A analise desses metabolitos e de grande importancia na determinacao da qualidade e monitoramento de biogenicas como histamina e tiramina relacionadas com episodios de intoxicacao em humanos. A cromatografia e uma tecnica de separacao química usada para caracterizar aminas biogenicas. Variacoes da tecnica (cromatografia liquida, em camada delgada e gasosa tem sido amplamente usadas, porem a complexidade da matriz alimentar faz com que sejam realizadas mudancas nos processos de extracao, derivatizacao e deteccao em concordancia com cada grupo de alimento. A cromatografia liquida de alta eficiencia (CLAE e o metodo mais utilizado na determinacao de aminas biogenicas em alimentos. Contudo, devido a importancia das aminas biogenicas no controle da qualidade e a seguranca do consumidor, os pesquisadores tentam desenvolver novos metodos com o intuito de uma analise mais rapida e precisa para o controle de alimentos no mercado. O objetivo da revisao e apresentar algumas tecnicas cromatograficas aplicadas no monitoramento de aminas biogenicas em produtos de origem animal.

The system NaVO3-Na2WO4-Na2W2O7

International Nuclear Information System (INIS)

Kazanbekov, V.R.; Gasanaliev, A.M.; Kazanbekov, R.G.

1994-01-01

Phase diagrams of sodium metavanadate-sodium ditungstate, sodium metavanadate-sodium tungstate systems and surface of primary crystallization of sodium metavabadate-sodium tungstate-sodium ditungstate system were studied. The system sodium metavanadate-sodium ditungstate is eutectic one. Compound NaVO 3 x2Na 2 WO 4 is formed in solid state in sodium metavanadate-sodium tungstate system. Liquidus surface of sodium metavanadate-sodium tungstate-sodium ditungstate is presented by three crystallization fields of initial components. Composition and melting point of ternary eutectics are determined

La importancia de la visualización en el aprendizaje de conceptos matemáticos

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Stella Nora Gatica

2012-07-01

Full Text Available En los últimos tiempos, el estudio de la visualización en el pensamiento matemático es objeto de numerosas investigaciones, en parte, posiblemente, debido al surgimiento de la computadora como un recurso didáctico para la comprensión de conceptos matemáticos. Este trabajo tiene como objetivo reflexionar sobre la importancia de poder relacionar e interpretar imágenes visuales (utilizando manipulables virtuales con la información que está dada en forma simbólica. Presentamos una propuesta didáctica para la comprensión del concepto de exactitud del método de Simpson utilizándose la interfase gráfica de MATLAB, GUI (graphical user interface, la cual fue puesta en práctica con alumnos de la asignatura Cálculo Numérico de la carrera Ingeniería Electrónica. El uso reflexivo y creativo de las nuevas tecnologías permiten dar un significado concreto a las nociones matemáticas. Por esta razón es necesario el diseño de nuevos materiales utilizando esta nueva metodología, donde muestren su uso efectivo en el aula. Del análisis realizado en la evaluación escrita y en el examen parcial de la asignatura, observamos que esta nueva metodología permite afianzar la comprensión y fijar el concepto con mayor facilidad a los que se someten a la enseñanza predominantemente algorítmica.

Summer sudden Na number density enhancements measured with the ALOMAR Weber Na Lidar

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D. Heinrich

2008-05-01

Full Text Available We present summer Na-densities and atmospheric temperatures measured 80 to 110 km above the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR. The Weber Na Lidar is part of ALOMAR, located at 69° N in Norway, 150 km north of the Arctic Circle. The sun does not set here during the summer months, and measurements require a narrowband Faraday Anomalous Dispersion Optical Filter (FADOF.

We discuss an observed sudden enhancement in the Na number density around 22:00 UT on 1 to 2 June 2006. We compare this observation with previous summer measurements and find a frequent appearance of Na number density enhancements near local midnight. We describe the time of appearance, the altitude distribution, the duration and the strength of these enhancements and compare them to winter observations. We investigate possible formation mechanisms and, as others before, we find a strong link between these Na number density enhancements and sporadic E layers.

Summer sudden Na number density enhancements measured with the ALOMAR Weber Na Lidar

Directory of Open Access Journals (Sweden)

D. Heinrich

2008-05-01

Full Text Available We present summer Na-densities and atmospheric temperatures measured 80 to 110 km above the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR. The Weber Na Lidar is part of ALOMAR, located at 69° N in Norway, 150 km north of the Arctic Circle. The sun does not set here during the summer months, and measurements require a narrowband Faraday Anomalous Dispersion Optical Filter (FADOF. We discuss an observed sudden enhancement in the Na number density around 22:00 UT on 1 to 2 June 2006. We compare this observation with previous summer measurements and find a frequent appearance of Na number density enhancements near local midnight. We describe the time of appearance, the altitude distribution, the duration and the strength of these enhancements and compare them to winter observations. We investigate possible formation mechanisms and, as others before, we find a strong link between these Na number density enhancements and sporadic E layers.

La importancia del estudio de la psicosis en el ámbito jurídico penal/The importance of psychosis study in the criminal legal field

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Agustín Salgado García

2018-01-01

Full Text Available Los sujetos que padecen psicosis, ven a alguien cuando no hay nadie y hasta perciben olores que nadie más huele. Tienen alucinaciones que son hechos falsos, no hablan con ninguna persona y aun así lo hacen, entablando conversaciones fuera de la realidad. La psicosis comprende un grave deterioro de las funciones ejecutivas la personalidad, en especial con relación a la realidad y que se manifiesta por el desajuste de interacción social. La comisión de conductas delictivas pueden originarse en estados psicóticos, lo que deberá considerarse al determinarse la individualización de la sanción penal, lo que es de ingente importancia para la defensa el fiscal y el juzgador.

INCERTIDUMBRE Y ORIENTACIÓN HACIA LOS ERRORES EN TIEMPOS DE CRISIS. LA IMPORTANCIA DE GENERAR CONFIANZA FOMENTANDO LA EFICACIA COLECTIVA

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Carmen Tabernero

2014-05-01

Full Text Available La crisis económica desencadena un nuevo escenario de incertidumbre que incide sobre el comportamiento organizacional de individuos y equipos de trabajo. El rendimiento organizacional se deteriora en contextos de incertidumbre—ante la amenaza percibida de mantener el trabajo, los individuos muestran desconfianza con la organización y competitividad con sus iguales. El presente artículo analiza el efecto de la incertidumbre sobre el rendimiento y los estados afectivos de los trabajadores, así como las estrategias cognitivas, afectivas y de personalidad (orientación hacia los errores para afrontar contextos de incertidumbre, bien como oportunidades para aprender o como situaciones a evitar. Igualmente se analizan las diferencias de género en los estilos de afrontamiento y los resultados de un programa de inoculación de afecto hacia los errores en el que se enfatizan las reacciones afectivas positivas. Por último, se discute la importancia de crear experiencias de cooperación en los equipos de trabajo que generen confianza y eficacia colectiva.

Muziki wa Hip Hop na Haki Za Kijamii: Dhima, Changamoto na ...

African Journals Online (AJOL)

Ni dhahiri kuwa haki za kijamii zinaweza kuwasilishwa kwa jamii pana kupitia sanaa ya hip hop. Makala haya basi, yanabainisha dhima na mchango wa muziki wa hip hop katika masuala ya haki za kijamii, yanafafanua changamoto za muziki huu katika kuwasilisha haki za kijamii na kutoa mapendekezo kwa makundi ...

Effect of sodium sulphate attack on the resistance to flexion, formation of expansive compounds and microcracking in cement paste; Efeito do ataque por sulfato de sodio na resistencia a flexao, formacao de compostos expansivos e microfissuracao de pastas de cimento

Energy Technology Data Exchange (ETDEWEB)

Souza, Rui Barbosa de; John, Vanderlei Moacyr; Cincotto, Maria Alba [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica], e-mail: rui.souza@poli.usp.br, e-mail: vanderley.john@poli.usp.br, e-mail: maria.cincotto@poli.usp.br; Simao, Cristina Aiex [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Tecnologia e Engenharia de Poco], e-mail: caies@petrobras.com.br

2008-06-15

The main objective of this research is to study the common methods for evaluating cement reactivity to sulfate attack. Resistance to sulfate attack was measured by determining the flexural strength in cement paste samples with exposure to Na{sub 2}SO{sub 4} solution (45,426 ppm of SO{sub 4}{sup 2-}), at a high temperature (55 deg C). The results of flexural strength showed that the resistance increases due to the attack because the products fill the pores. (author)

Sequential growth of sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell–shell nanoparticles for photodynamic therapy

Energy Technology Data Exchange (ETDEWEB)

Peng, Huang-Yong; Ding, Bin-Bin; Ma, Yin-Chu [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Sun, Shi-Qi [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu 730046 (China); Tao, Wei [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Guo, Yan-Chuan [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Guo, Hui-Chen, E-mail: ghch-2004@hotmail.com [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu 730046 (China); Yang, Xian-Zhu, E-mail: yangxz@hftu.edu.cn [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Qian, Hai-Sheng, E-mail: shqian@hfut.edu.cn [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China)

2015-12-01

Graphical abstract: The monodisperse elliptical NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell–shell nanoparticles have been synthesized successfully by a facile sequential growth process, which can be used as transducer for photodynamic therapy of cancer cells. - Highlights: • The NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb nanoparticles have been fabricated successfully. • The as-prepared nanoparticles show strong fluorescence excited at 980 or 808 nm. • The nanoparticles were transferred into the aqueous phase via a facile process. • Photosensitizers were loaded into the composites for photodynamic therapy. - Abstract: Upconversion (UC) nanostructures have attracted much interest for their extensive biological applications. In this work, we describe a sequential synthetic route to prepare sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell upconversion nanoparticles. The as-prepared products were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM, JEM 2100F), respectively. The as-prepared core–shell nanoparticles of NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb are composed of elliptical nanoparticles with a length of 80 nm and width of 42 nm, which show efficient upconversion fluorescence excited at 808 nm indicating the formation of core–shell–shell sandwiched nanostructures. In addition, the as-prepared sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell upconversion nanoparticles also show strong upconversion fluorescence excited at 980 nm. Amphiphilic mPEG{sub 2k}-b-PEBEP{sub 6K} copolymers (denoted as PPE) were chosen to transfer these hydrophobic UCNPs into the aqueous phase for biological application. In vitro photodynamic therapy of cancer cells show that the viability of cells incubated with the nanoparticles loaded with MC 540 was significantly lower as compared to the nanoparticles without photosensitizers exposed to NIR laser.

Intracellular Na+ regulation of Na+ pump sites in cultured vascular smooth muscle cells

International Nuclear Information System (INIS)

Allen, J.C.; Navran, S.S.; Seidel, C.L.; Dennison, D.K.; Amann, J.M.; Jemelka, S.K.

1989-01-01

Enzymatically dispersed cells from canine saphenous vein and femoral artery were grown in fetal calf serum and studied at day 0 (freshly dispersed) through confluence in primary culture. Intracellular Na levels (Nai), but not intracellular K (Ki), were increased after 24 h in culture and then decreased to a steady state by 4 days. Na+ pump site number [( 3 H] ouabain binding) increased through day 3 and remained elevated. Nai was still elevated at 2 days when the Na+ pump site number began to increase. Total pump turnover (maximum ouabain-inhibited 86 Rb uptake) reflected the increase in Na+ pump site number. These key events precede the observed increases in both protein production and cellular proliferation. If the same cells are maintained in defined medium, without fetal calf serum, Nai, Ki, and the number of [ 3 H]ouabain binding sites do not change with time. These data are consistent with the suggestion that the initial mitogenic response of vascular smooth muscle cells to fetal calf serum involves an increased Na+ influx, and a Nai accumulation, caused by low Na+ pump density. The synthesis of new pump sites effects a decrease in the accumulated Nai, which may be related to cell proliferation

On the Stability of NaO2 in Na-O2 Batteries.

Science.gov (United States)

Liu, Chenjuan; Carboni, Marco; Brant, William R; Pan, Ruijun; Hedman, Jonas; Zhu, Jiefang; Gustafsson, Torbjörn; Younesi, Reza

2018-04-25

Na-O 2 batteries are regarded as promising candidates for energy storage. They have higher energy efficiency, rate capability, and chemical reversibility than Li-O 2 batteries; in addition, sodium is cheaper and more abundant compared to lithium. However, inconsistent observations and instability of discharge products have inhibited the understanding of the working mechanism of this technology. In this work, we have investigated a number of factors that influence the stability of the discharge products. By means of in operando powder X-ray diffraction study, the influence of oxygen, sodium anode, salt, solvent, and carbon cathode were investigated. The Na metal anode and an ether-based solvent are the main factors that lead to the instability and decomposition of NaO 2 in the cell environment. This fundamental insight brings new information on the working mechanism of Na-O 2 batteries.

NaK handling and removal

International Nuclear Information System (INIS)

Desreumaux, J.; Rodriguez, G.; Guigon, A.; Verdelli, J.; Thomine, G.

1997-01-01

Sodium-potassium alloy is used in specific application in French Fast Breeder Reactors as: cold traps, NaK bubbler for argon purification, valves and also in experimental irradiation devices. lt has been preferred to sodium because it is liquid from + 7 deg. C for the most common peritectic alloy. After its use, NaK is considered as a hazardous waste (nuclear or not) due to its high reactivity with air and water. The most important risk remains in handling NaK systems which have not been operated for some time. The NaK will be covered with a crust of the superoxide K02 which is a strong oxidising agent. Thermodynamically, K02 will react with most organic material or metallic dust or swarfs and can also react with additional NaK to give sufficient heat to boil part of the NaK, resulting in a sudden increase in pressure and small explosions. We describe the formation given to experimenters in our Sodium School and the CEA's experience in treating specific devices for transportation, decanting of tanks, tank opening and NaK removal. (author)

Angiotensin II-induced hypertension increases plasma membrane Na pump activity by enhancing Na entry in rat thick ascending limbs.

Science.gov (United States)

Gonzalez-Vicente, Agustin; Garvin, Jeffrey L

2013-11-01

Thick ascending limbs (TAL) reabsorb 30% of the filtered NaCl load. Na enters the cells via apical Na-K-2Cl cotransporters and Na/H exchangers and exits via basolateral Na pumps. Chronic angiotensin II (ANG II) infusion increases net TAL Na transport and Na apical entry; however, little is known about its effects on the basolateral Na pump. We hypothesized that in rat TALs Na pump activity is enhanced by ANG II-infusion, a model of ANG II-induced hypertension. Rats were infused with 200 ng·kg(-1)·min(-1) ANG II or vehicle for 7 days, and TAL suspensions were obtained. We studied plasma membrane Na pump activity by measuring changes in 1) intracellular Na (Nai) induced by ouabain; and 2) ouabain-sensitive oxygen consumption (QO2). We found that the ouabain-sensitive rise in Nai in TALs from ANG II-infused rats was 12.8 ± 0.4 arbitrary fluorescent units (AFU)·mg(-1)·min(-1) compared with only 9.9 ± 1.1 AFU·mg(-1)·min(-1) in controls (P Na pump expression, the number of Na pumps in the plasma membrane, or the affinity for Na. When furosemide (1.1 mg·kg(-1)·day(-1)) was coinfused with ANG II, no increase in plasma membrane Na pump activity was observed. We concluded that in ANG II-induced hypertension Na pump activity is increased in the plasma membrane of TALs and that this increase is caused by the chronically enhanced Na entry occurring in this model.

Silicene for Na-ion battery applications

KAUST Repository

Zhu, Jiajie

2016-08-19

Na-ion batteries are promising candidates to replace Li-ion batteries in large scale applications because of the advantages in natural abundance and cost of Na. Silicene has potential as the anode in Li-ion batteries but so far has not received attention with respect to Na-ion batteries. In this context, freestanding silicene, a graphene-silicene-graphene heterostructure, and a graphene-silicene superlattice are investigated for possible application in Na-ion batteries, using first-principles calculations. The calculated Na capacities of 954mAh/g for freestanding silicene and 730mAh/g for the graphenesilicene superlattice (10% biaxial tensile strain) are highly competitive and potentials of >0.3 V against the Na/Na potential exceed the corresponding value of graphite. In addition, the diffusion barriers are predicted to be <0.3 eV.

LA IMPORTANCIA DE LA INNOVACIÓN EN EL PRODUCTO PARA GENERAR POSICIONAMIENTO EN LOS JÓVENES

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WILSON GIRALDO PÉREZ

2017-01-01

Full Text Available Este artículo de investigación financiado por la Universidad de los Llanos presenta, de forma jerarquizada los factores de innovación que los consumidores aceptan como válidos para mejorar los procesos de posicionamiento y compra de productos que se ofrecen en el mercado. En este caso, los consumidores son jóvenes, hombres y mujeres, con edades que oscilan entre 16 y 24 años, residentes en Villavicencio (Colombia quienes participaron del estudio cuantitativo. Así se planteó como hipótesis que existe una relación positiva entre las características demográficas del consumidor (edad y nivel socioeconómico y la innovación del producto; los resultados evidencian que este grupo etario, mayoritariamente, se muestra sensible al análisis económico, puesto que gran parte de ellos dependen financieramente de un adulto y eso limita sus posibilidades de compra y consumo. En orden de importancia jerárquica, para los encuestados, la mayor calificación la obtuvieron los factores de: valor de uso y calidad percibida del producto y la menor calificación corresponde al precio de estos, finalmente no se evidencia la existencia de correlación alguna asociada a los elementos demográficos de los jóvenes de la ciudad y los factores de innovación.

Hydrolysis of Rice Straw Pretreated by Na2SO3 Over Fe-resin/NaCl

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YANG Hui

2017-05-01

Full Text Available To increase the conversion of rice straw(RS and the yield of products, we employed three methods, which were ultrasonic wave, steam explosion and Na2SO3 pretreatment to pretreat RS(the treated RS noted as CS-RS, ZQ-RS and Na2SO3-RS, respectively and found that Na2SO3 treatment was the best pretreatment method based on XRD, SEM, elemental analysis and content of cellulose, hemicellulose and lignin. The conversion of Na2SO3-RS and the yield of total reducing sugar(TRS and levulinic acid(LA were 97.3%, 29.6% and 13.5%, respectively by 10% Fe-resin in 3.3% NaCl solution under 200 ℃.

Na+/H+ and Na+/NH4+ exchange activities of zebrafish NHE3b expressed in Xenopus oocytes

Science.gov (United States)

Ito, Yusuke; Kato, Akira; Hirata, Taku; Hirose, Shigehisa

2014-01-01

Zebrafish Na+/H+ exchanger 3b (zNHE3b) is highly expressed in the apical membrane of ionocytes where Na+ is absorbed from ion-poor fresh water against a concentration gradient. Much in vivo data indicated that zNHE3b is involved in Na+ absorption but not leakage. However, zNHE3b-mediated Na+ absorption has not been thermodynamically explained, and zNHE3b activity has not been measured. To address this issue, we overexpressed zNHE3b in Xenopus oocytes and characterized its activity by electrophysiology. Exposure of zNHE3b oocytes to Na+-free media resulted in significant decrease in intracellular pH (pHi) and intracellular Na+ activity (aNai). aNai increased significantly when the cytoplasm was acidified by media containing CO2-HCO3− or butyrate. Activity of zNHE3b was inhibited by amiloride or 5-ethylisopropyl amiloride (EIPA). Although the activity was accompanied by a large hyperpolarization of ∼50 mV, voltage-clamp experiments showed that Na+/H+ exchange activity of zNHE3b is electroneutral. Exposure of zNHE3b oocytes to medium containing NH3/NH4+ resulted in significant decreases in pHi and aNai and significant increase in intracellular NH4+ activity, indicating that zNHE3b mediates the Na+/NH4+ exchange. In low-Na+ (0.5 mM) media, zNHE3b oocytes maintained aNai of 1.3 mM, and Na+-influx was observed when pHi was decreased by media containing CO2-HCO3− or butyrate. These results provide thermodynamic evidence that zNHE3b mediates Na+ absorption from ion-poor fresh water by its Na+/H+ and Na+/NH4+ exchange activities. PMID:24401990

The relation between aging, aortic NaF avidity and coronary artery NaF avidity: A NaF PET CT study

DEFF Research Database (Denmark)

Blomberg, Björn; Thomassen, Anders; Hildebrandt, Malene

2013-01-01

volunteers without traditional cardiovascular risk factors were prospectively assessed by Sodium 18-Fluoride (Na-18F) PET CT imaging. Global aortic uptake of Na-18F was determined by calculating the average aortic blood pool subtracted maximum standardized uptake value (cSUV) [maximum SUVaorta - mean...

Rescue of Na+ and H+ binding in Na+,K+-ATPase M8 aspartate mutants by secondary mutation

DEFF Research Database (Denmark)

Holm, Rikke; Einholm, Anja P.; Andersen, Jens Peter

A mutation replacing the aspartate in transmembrane segment M8 in the a3-isoform of Na,K-ATPase with asparagine has been found in patients with rapid-onset dystonia parkinsonism or alternating hemiplegia of childhood. This aspartate may be a critical Na+ coordinating residue, but the crystal......-isoforms of Na,K-ATPase, and much smaller effects were seen for other mutations to the M8 aspartate, which were less disruptive of Na+ binding than mutations to other residues related to Na+ site III. The D928 (rat a1 numbering) mutations strongly diminished the cooperativity of Na+ binding. Moreover the p......H optimum of Na,K-ATPase activity was left-shifted, again with D928N being most disruptive. The reduced affinity for activating Na+ and for inhibitory protons, caused by D928N and D928A mutations, could be rescued by introduction of an additional mutation of a glutamate located far away from D928....

Salinity tolerance in barley (hordeum vulgare l.): effects of varying NaCl, K/sup +/ Na/sup +/ and NaHCO/sub 3/ levels on cultivars differing in tolerance

International Nuclear Information System (INIS)

Mahmood, K.

2011-01-01

Although barley (Hordeum vulgare L.) is regarded as salt tolerant among crop plants, its growth and plant development is severely affected by ionic and osmotic stresses in salt-affected soils. To elucidate the tolerance mechanism, growth and ion uptake of three barley cultivars, differing in salt tolerance, were examined under different levels of NaCl, K/sup +/ Na/sup +/ and NaHCO/sub 3/ in the root medium. The cultivars differed greatly in their responses to varying root medium conditions. Plant growth was more adversely affected by NaHCO/sub 3/ than NaCl. In general, biomass yields were comparable under control and 100 mM NaCl. However, growth of all three cultivars was significantly inhibited by NaHCO/sub 3/ even at low concentration (10 mM). Improved K/sup +/ supply in saline medium increased K/sup +/ uptake and growth of less tolerant cultivars. K/sup +/ uptake was more adversely affected by NaHCO/sub 3/ than NaCl salinity. Selective K/sup +/ uptake and lower Cl/sup -/ in shoots seemed to be associated with the growth responses. K application would help better growth of these cultivars on K-deficient saline-sodic soils and under irrigation with poor quality water having high Residual Sodium Carbonate (RSC) and/or Sodium Adsorption Ratio (SAR). (author)

La importancia de los materiales en las viviendas de muy bajo coste

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Salas, Julián

1992-09-01

Full Text Available This text fits into the context of the attempt to emphasize the considerable importance of the factor of the construction materials in the subsection of low cost housing in Developing Countries in general and in Latín America in particular. The author tries to quantify, in a global manner, the repercussion of the materials through different assumptions and to show how it increases as the sections of installations and finishes diminish —in fact, practically disappear—. In accordance with this and as a consequence, the author discusses the necessity to use autochthonous materials and to support the research and technological development which lay stress on the use of alternative materials and the re-use of agro-industrial waste. As a pan of the Chapter V reproduced here, a special Section entitled "The Industry of Construction Materials" is contemplated, a section which we omitted and which can be found in n.º 198 of this Quarterly where it was originally published.

El texto que sigue se encuadra en el contexto de intentar enmarcar la importancia considerable del capítulo de los materiales de construcción en el subsector de las viviendas de muy bajo coste en los Países en Vías de Desarrollo en general, y en Latinoamérica en particular. El autor trata de cuantificar, en forma global, la repercusión de los materiales en varios supuestos y como ésta aumenta al disminuir —prácticamente desaparecer— las partidas de instalaciones y acabados. De conformidad y como consecuencia de lo anterior, el autor se ocupa de la necesidad de emplear materiales autóctonos y de apoyar la investigación y el desarrollo tecnológico que ponen énfasis en la utilización de materiales alternativos y la reutilización de desechos agro-industriales. Formando parte del Capítulo V que se reproduce, se contempla un apartado específico con el título "La Industria de Materiales de la Construcción" que hemos omitido, remitiendo al lector

Glutathionylation-Dependence of Na+-K+-Pump Currents Can Mimic Reduced Subsarcolemmal Na+ Diffusion

OpenAIRE

Garcia, Alvaro; Liu, Chia-Chi; Cornelius, Flemming; Clarke, Ronald?J.; Rasmussen, Helge?H.

2016-01-01

The existence of a subsarcolemmal space with restricted diffusion for Na+ in cardiac myocytes has been inferred from a transient peak electrogenic Na+-K+ pump current beyond steady state on reexposure of myocytes to K+ after a period of exposure to K+-free extracellular solution. The transient peak current is attributed to enhanced electrogenic pumping of Na+ that accumulated in the diffusion-restricted space during pump inhibition in K+-free extracellular solution. However, there are no know...

Myocardial Na,K-ATPase: Clinical aspects

OpenAIRE

Kjeldsen, Keld

2003-01-01

The specific binding of digitalis glycosides to Na,K-ATPase is used as a tool for Na,K-ATPase quantification with high accuracy and precision. In myocardial biopsies from patients with heart failure, total Na,K-ATPase concentration is decreased by around 40%; a correlation exists between a decrease in heart function and a decrease in Na,K-ATPase concentration. During digitalization, around 30% of remaining pumps are occupied by digoxin. Myocardial Na,K-ATPase is also influenced by other drugs...

Down-Regulation of the Na+-Coupled Phosphate Transporter NaPi-IIa by AMP-Activated Protein Kinase

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Miribane Dërmaku-Sopjani

2013-11-01

Full Text Available Background/Aims: The Na+-coupled phosphate transporter NaPi-IIa is the main carrier accomplishing renal tubular phosphate reabsorption. It is driven by the electrochemical Na+ gradient across the apical cell membrane, which is maintained by Na+ extrusion across the basolateral cell membrane through the Na+/K+ ATPase. The operation of NaPi-IIa thus requires energy in order to avoid cellular Na+ accumulation and K+ loss with eventual decrease of cell membrane potential, Cl- entry and cell swelling. Upon energy depletion, early inhibition of Na+-coupled transport processes may delay cell swelling and thus foster cell survival. Energy depletion is sensed by the AMP-activated protein kinase (AMPK, a serine/threonine kinase stimulating several cellular mechanisms increasing energy production and limiting energy utilization. The present study explored whether AMPK influences the activity of NAPi-IIa. Methods: cRNA encoding NAPi-IIa was injected into Xenopus oocytes with or without additional expression of wild-type AMPK (AMPKα1-HA+AMPKβ1-Flag+AMPKγ1-HA, of inactive AMPKαK45R (AMPKα1K45R+AMPKβ1-Flag+AMPKγ1-HA or of constitutively active AMPKγR70Q (AMPKα1-HA+AMPKβ1-Flag+AMPKγ1R70Q. NaPi-IIa activity was estimated from phosphate-induced current in dual electrode voltage clamp experiments. Results: In NaPi-IIa-expressing, but not in water-injected Xenopus oocytes, the addition of phosphate (1 mM to the extracellular bath solution generated a current (Ip, which was significantly decreased by coexpression of wild-type AMPK and of AMPKγR70Q but not of AMPKαK45R. The phosphate-induced current in NaPi-IIa- and AMPK-expressing Xenopus ooocytes was significantly increased by AMPK inhibitor Compound C (20 µM. Kinetic analysis revealed that AMPK significantly decreased the maximal transport rate. Conclusion: The AMP-activated protein kinase AMPK is a powerful regulator of NaPi-IIa and thus of renal tubular phosphate transport.

Importancia de la Manometría Anorrectalen la Infancia

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Daisy Naranjo Hernández

1999-09-01

Full Text Available RESUMEN Al registrar cambios de presión en órganos musculares huecos, el estudio manométrico anorrectal ha permitido llegar a conclusiones acerca del mecanismo de continencia anorrectal, la función esfinteriana y la sensación rectal. Se utilizó el método de catéteres perfundidos y balón intrarrectal para el estímulo por distensión. Se estudiaron 340 pacientes, 214 masculinos y 126 femeninos, con una edad promedio de 6,5 años. Se formaron 3 grupos: I. Constipación crónica, II. Crónica más encopresis y III. Incontinencia anal. Entre las variables manométricas que se estudiaron: presencia o no del reflejo rectoanal inhibitorio inducido (RRII, presión de reposo, longitud, tanto por ciento de relajación del mismo y volumen crítico capaz de desencadenar respuesta esfinteriana. Se realizó estudio de colon por enema y se halló mayor correlación entre megacolon radiográfico y el mayor porcentaje de ausencia manométrica del RRAI. El grupo II mostró mayor valor de presión basal del EAI con un menor tanto por ciento de relajación y un mayor número de casos con ausencia del RRAI. En el grupo III se obtuvo el valor más bajo de presión basal del EAI mayor por ciento de relajación y mayor número de casos con ausencia del EAI. Se demuestra la importancia del estudio en el manejo integral del niño con afecciones anorrectales, el que fue indispensable en el diagnóstico de la enfermedad de Hirschprung. Su empleo se recomienda en todos los servicios de Gastroenterología Pediátrica.On registering pressure changes in the muscular hollow organs, the anorectal manometric study has allowed to reach conclusions about the mechanism of anorectal continence, the sphincteral function and the anorectal sensation. The method of perfused catheters and intrarectal balloon was used to attain the stimulus by distention. 340 patients, 214 males and 126 females with an average age of 6.5 years old, were studied. Patients were divided into 3 groups

Thermodynamic study of NaFe complex oxides. High temperature properties of Na sub 5 FeO sub 4 and Na sub 3 FeO sub 3

CERN Document Server

Furukawa, T

2002-01-01

In order to contribute the investigation into corrosion mechanism of the structural materials by leakage sodium, thermodynamic study of Na-Fe complex oxides formed by the reactions was carried out. Na sub 5 FeO sub 4 and Na sub 3 FeO sub 3 were used as the sample. Its high temperature properties (i.e. melting, solidification and transformation) were observed by Differential Scanning Calorimetry, DSC. Moreover, the original test named 'melting point confirmation test' was performed for the observation of traces of melting and solidification after the tests. Following contents have been obtained by this study. (1) Na sub 5 FeO sub 4 was stably as the solid without phase transformation and melting until 800degC. However, the compound was showing a tendency to change into Na sub 4 FeO sub 3 with temperature increasing under the low oxygen potential. (2) The stability of Na sub 3 FeO sub 3 is the same as that of Na sub 5 FeO sub 4 until 700degC. Over the temperature, the compound was changed differential compound ...

Metallic Na formation in NaCl crystals with irradiation of electron or vacuum ultraviolet photon

Energy Technology Data Exchange (ETDEWEB)

Owaki, Shigehiro [Osaka Prefecture Univ., Sakai, Osaka (Japan). Coll. of Integrated Arts and Sciences; Koyama, Shigeko; Takahashi, Masao; Kamada, Masao; Suzuki, Ryouichi

1997-03-01

Metallic Na was formed in NaCl single crystals with irradiation of a variety of radiation sources and analyzed the physical states with several methods. In the case of irradiation of 21 MeV electron pulses to the crystal blocks, the optical absorption and lifetime measurement of positron annihilation indicated appearance of Na clusters inside. Radiation effects of electron beam of 30 keV to the crystals in vacuum showed the appearance of not only metallic Na but atomic one during irradiation with Auger electron spectroscopy. Intense photon fluxes in vacuum ultraviolet region of synchrotron radiation were used as another source and an analyzing method of ultraviolet photoelectron spectroscopy. The results showed the metallic Na layered so thick that bulk plasmon can exist. (author)

Os cenários de aprendizagem: espaços de cuidado, conhecimento, poder e cidadania na formação do enfermeiro

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Carmen Maria dos Santos Lopes Monteiro Dantas Silva

2010-01-01

Full Text Available Diario encontramos espacios de poder y ciudadanía en que se desarrolla: la asistencia, la investigación, y la formación profesional. Esto artigo tiene como objeto de estudio: la importancia de escenarios de aprendizaje para la formación de los estudiantes de enfermería. Los objetivos son describir la importancia de los escenarios de aprendizaje, para el estudiante de enfermería y analizar la importancia de escenarios de aprendizaje en la formación. Se uso la investigación cualitativa, de junio a julio/2008, en la Universidad Centro / RJ. Los temas son 41 estudiantes del 1er periodo de Enfermería, la 3ª clase para integrar el nuevo plan de estudios de metodologías activas. Los datos se agruparon en cuatro unidades temáticas: el espacio para el conocimiento y el aprendizaje; área de la reconstrucción de las experiencias de la enfermería; zona de la escuela y de la ciudadanía, los aspectos de la vida, ideas, conocimientos, información, preguntas y experiencias. Los estudiantes destacaron los escenarios aprender a cuidar los espacios, el poder y la ciudadanía para la formación profesional.

IMPORTANCIA DE LOS HUERTOS FAMILIARES EN LA ESTRATEGIA DE DIVERSIFICACIÓN DEL INGRESO Y EN LA CONSERVACIÓN in situ DE Pouteria lucuma [R et. Pav] O. Kze.

OpenAIRE

Borbor Ponce, Miryam; Universidad Nacional de Trujillo. Av. Juan Pablo (s/n). Trujillo, Perú.; Mercado, Waldemar; Universidad Nacional Agraria La Molina. Facultad de Economía y Planificación. Av. La Molina s/n. Lima; Perú.; Soplín Villacorta, Hugo; Universidad Nacional Agraria La Molina. Facultad de Agronomía, Departamento de Fitotecnia. Av. La Molina s/n. Lima; Perú.; Blas Sevillano, Raúl; Universidad Nacional Agraria La Molina. Facultad de Agronomía, Departamento de Fitotecnia. Av. La Molina s/n. Lima; Perú.

2016-01-01

Se analizó la importancia de los huertos familiares en la conservación in situ de lúcuma, cultivo complementario a la economía de las familias de la comisión de riego El Moro (Trujillo, La Libertad) y de la zona baja de la cuenca del río Yaután (Casma, Ancash) en el norte del Perú. La información generada mediante encuestas a 158 productores, fue analizada con técnicas estadísticas de contraste de vectores de medias y prueba de Z entre ambas zonas. La percepción del agricultor del aporte del ...

Relevancia de la formación estadística en la universidad. La importancia de encontrarles sentido a las matemáticas

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Jorge Oscar Rouquette Alvarado

2014-01-01

Full Text Available El presente trabajo tiene por objetivo señalar algunos elementos que destacan la relevancia de la enseñanza de la estadística en la universidad; se hace hincapié en los beneficios que trae consigo enfatizar el sentido y la interpretación de las medidas estadísticas en busca de hacerlas atractivas al estudiantado, además de la oportunidad de inducir su apreciación al mostrar que aquellos procedimientos matemáticos que se les enseña tienen múltiples aplicaciones concretas en su futuro profesional, pero que también las hay en la vida en general. Se realiza una revisión teórica sobre la importancia mencionada, destacando en especial el significado de la formación estadística. Asimismo se ofrecen argumentos que exhiben que la alfabetización estadística es parte de la cultura general y contribuye para el desarrollo del pensamiento crítico.

La controversia jurídica y filosófica librada en la Nueva Granada en torno a la liberación de los esclavos y la importancia económica-social de la esclvitud en el Siglo XIX

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Jaime Jaramillo Uribe

1969-01-01

que se libro en la Nueva Granada en torno a la libertad de los esclavos, una vez producida la Independencia, debe tenerse en cuenta la importancia que tuvo la institución de la esclavitud negra en la economía y en la sociedad neogranadina del siglo XVIII y la que aún conservaba a mediados del siglo XIX.

Scintillation efficiency measurement of Na recoils in NaI(Tl) below the DAMA/LIBRA energy threshold

Energy Technology Data Exchange (ETDEWEB)

Xu, Jingke; Shields, Emily; Calaprice, Frank; Westerdale, Shawn; Froborg, Francis; Suerfu, Burkhant; Alexander, Thomas; Aprahamian, Ani; Back, Henning O.; Casarella, Clark; Fang, Xiao; Gupta, Yogesh K.; Ianni, Aldo; Lamere, Edward; Lippincott, W. Hugh; Liu, Qian; Lyons, Stephanie; Siegl, Kevin; Smith, Mallory; Tan, Wanpeng; Kolk, Bryant Vande

2015-07-01

The dark matter interpretation of the DAMA modulation signal depends on the NaI(Tl) scintillation efficiency of nuclear recoils. Previous measurements for Na recoils have large discrepancies, especially in the DAMA/LIBRA modulation energy region. We report a quenching effect measurement of Na recoils in NaI(Tl) from 3 to 52 keVnr, covering the whole DAMA/LIBRA energy region for dark matter-Na scattering interpretations. By using a low-energy, pulsed neutron beam, a double time-of-flight technique, and pulse-shape discrimination methods, we obtained the most accurate measurement of this kind for NaI(Tl) to date. The results differ significantly from the DAMA reported values at low energies but fall between the other previous measurements. We present the implications of the new quenching results for the dark matter interpretation of the DAMA modulation signal.

Synthesis of Ag or Pt Nanoparticles by Hydrolysis of Either Ag2Na or PtNa

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Huabin Wang

2008-01-01

Full Text Available Ag and Pt nanoparticles have successfully been synthesized by hydrolysis of either Ag2Na or PtNa at room temperature. The oxidation of sodium in the Pt-Na pellets was much faster than that in the Ag-Na pellets since Pt is a catalyst for H2O formation reaction from hydrogen and oxygen at room temperature. The hydrolysis byproduct, NaOH, has a high solubility and easily is removed. This method offers a simple method of preparing transition metal nanoparticles. The Ag and Pt nanoparticles prepared by this method were crystalline in nature, and spherical in shape with a mean size of around 10 nm.

Dynamic polarizabilities and Van der Waals coefficients for alkali atoms Li, Na and alkali dimer molecules Li2, Na2 and NaLi

Science.gov (United States)

Mérawa, M.; Dargelos, A.

1998-07-01

The present paper gives an account of investigations of the polarizability of the alkali atoms Li, Na, diatomics homonuclear and heteronuclear Li2, Na2 and NaLi at SCF (Self Consistent Field) level of approximation and at correlated level, using a time Time-Dependent Gauge Invariant method (TDGI). Our static polarizability values agree with the best experimental and theoretical determinations. The Van der Waals C6 coefficients for the atom-atom, atom-dimer and dimer-dimer interactions have been evaluated. Les polarisabilités des atomes alcalins Li, Na, et des molécules diatomiques homonucléaires et hétéronucléaire Li2, Na2 et NaLi, ont été calculées au niveau SCF (Self Consistent Field) et au niveau corrélé à partir d'une méthode invariante de jauge dépendante du temps(TDGI). Nos valeurs des polarisabilités statiques sont en accord avec les meilleurs déterminations expérimentales et théoriques. Les coefficients C6 de Van de Waals pour les interactions atome-atome, atome-dimère et dimère-dimère ont également été évalués.

Structure-function relationships of Na+, K+, ATP, or Mg2+ binding and energy transduction in Na,K-ATPase

DEFF Research Database (Denmark)

Jorgensen, Peter L.; Pedersen, Per Amstrup

2000-01-01

Na,K-ATPase; Mutagenesis; Na+ binding; K+ binding; Tl+ binding; Mg2+ binding; ATP binding; Cation binding site; Energy transduction......Na,K-ATPase; Mutagenesis; Na+ binding; K+ binding; Tl+ binding; Mg2+ binding; ATP binding; Cation binding site; Energy transduction...

Revisión teórica de la discapacidad visual, estudio sobre la importancia de la creatividad en la Educación Especial

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José Enrique Llamazares de Prado

2017-06-01

Full Text Available En el siguiente trabajo se plantea la importancia en la educación de elementos clave como son la creatividad, y el pensamiento divergente. Esta exposición tiene como principal objetivo la revisión de los estudios de discapacidad visual y creatividad. Pretendemos una reflexión sistematizada de la estimación cuantitativa sintética de todos los estudios disponibles, planteando un marco teórico relacionando la creatividad en la educación de alumnos con deficiencia visual, aportándose valoraciones personales. Dentro de las conclusiones obtenidas, se evidencia la función del potencial creativo, por medio del pensamiento divergente en la creación de conceptos e ideas, para la resolución de problemas, con interés no solo en la educación, sino en cualquier ámbito de la vida.

At NA2

CERN Multimedia

1977-01-01

One of the NA2 calorimeter sections is moved in. The NA2 calorimeter was divided in two halves, to the left and the right of the beam, each half consisting of sheets of passive high Z material interleaved with blades of plastic scintillators. The photo shows on the right, the upstream 'electron' module with eleven lead plates for a total radiation length of 20.

Na+-K+ pump in chronic renal failure

International Nuclear Information System (INIS)

Deepak, K.; Kahn, T.

1987-01-01

This review summarizes the evidence for the defect in Na + -K + pump in chronic renal failure, considers the role of various factors in causing this defect, and discusses the clinical implications thereof. Intracellular Na is elevated in erythrocytes, leukocytes, and muscle cells from some patients with chronic renal failure (CRF). Recent evidence suggest that this elevation of cell Na may be, in large part, a consequence of decreased number of Na + -K + pump units per cell. Maintenance dialysis over a period of weeks ameliorates the defect in intracellular Na + , and this improvement is contemporaneous with an increase in the number of Na + -K + pump sites per cell. In erythrocytes with normal cell Na + , acute hemodialysis increases the rate of 22 Na + and 42 K + transport. Many factors such as the presence of retained toxic metabolite or circulating inhibitor in the uremic plasma, or biochemical changes produced by acute hemodialysis, may explain this finding. In cells with high cell Na + , the pump-mediated 42 K + transport is normalized at the expense of a raised cell Na + . The decreased muscle membrane potential in uremic subjects has been attributed to a decreased activity of Na + -K + pump. The authors discuss the role of hormonal abnormalities and circulating inhibitors, which may cause an acute inhibition of the pump and of other factors such as K + depletion, which may cause more chronic alterations. The implications of alteration of Na + and K + pump transport and raised cell Na + on other non-pump-mediated transport pathways are discussed. Raised cell Na + may be a marker for the adequacy of maintenance dialysis in patients with end-stage renal failure

Pozitivni in negativni vplivi risank na otroke

OpenAIRE

Povše, Nika

2017-01-01

V tej diplomski nalogi smo raziskovali pozitivne in negativne vplive risank na otroke. Začeli smo z zgodovino televizije, tako svetovno zgodovino kot zgodovino televizije na Slovenskem. Na isti način smo pregledali tudi zgodovino risank. Raziskovali smo otrokov razvoj, predvsem tiste vidike, ki so izpostavljeni vplivom risank, kot so morala, jezik, domišljija in učenje. Sledilo je raziskovanje negativnih in pozitivnih vplivov, ki jih imajo risanke na otroke, kar je tudi naš glavni problem te ...

Vpliv konfucija na sodobno izobraževanje na Kitajskem

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Katja Skitek

2009-12-01

Full Text Available Izobraževanje na Kitajskem je bilo vedno trdno povezano s Konfucijem in konfucianizmom, kar pa ni čudno, saj je bil Konfucij prvi, ki je poudarjal moč z nanja in izobraževanja. LR Kitajska je v zadnjih petdesetih letih počasi in postopoma začela uveljavljati določene spremembe v vzgojno-izobraževalni sistem. Kakšne so te spremembe in koliko nanje še vedno vpliva konfucianizem, bo osrednja tema pričujočega članka. Konfucianizem danes na Kitajskem ni preveč popularen, izobraženci pa so se razporedili v dve skupini: eni trdijo, da je njegov vpliv še vedno velik, drugi pa zatrjujejo, da nima več nobenega vpliva na sodobno življenje. Katera stran ima prav? Konfucij je v prvi vrsti poudarjal pomembnost moralnih vrednot vsakega človeka in prav moralne vrednote, za katere se je zavzemal, so še danes trdno zasidrane v kitajski kulturi. Ali je torej sploh mogoče popolnoma izriniti Konfucija iz sodobnega izobraževanja?

Low-spin states of 23Na

International Nuclear Information System (INIS)

Bakkum, E.L.

1987-01-01

A study of 23 Na via the 22 Ne(p,γ) 23 Na and 23 Na(γ,γ) 23 Na reactions is presented. Only a limited number of resonances has been studied, selected on the basis of strong excitation of the lowest levels of which the spin was unknown. As a result the spins are now known of all levels of 23 Na with excitation energies up to 7 MeV, except for a few high-spin states which are too weakly excited in the decay of the known 22 Ne(p,γ) resonances. The mean lifetimes of the 23 Na levels at 4.43 and 7.89 MeV were found to be 350±70 and 220±17 attoseconds (1 attosecond = 10 -18 seconds) respectively. 97 refs.; 22 figs.; 12 tabs

Response of saliva Na/K ratio to changing Na supply of lactating cows under tropical conditions

NARCIS (Netherlands)

Thiangtum, Wandee; Schonewille, J Thomas; Verstegen, Martin Wa; Arsawakulsudhi, Supot; Rukkwamsuk, Theera; Hendriks, Wouter H

BACKGROUND: Factorial determination of the sodium (Na) requirement of heat-stressed lactating cows is hindered by accurate estimates of the Na losses through sweat. Direct studies, therefore, may be needed requiring information on the time course of healthy animals to become Na depleted and the

Response of saliva Na/K ratio to changing Na supply of lactating cows under tropical conditions

NARCIS (Netherlands)

Thiangtum, Wandee; Schonewille, Thomas J.; Verstegen, Martin W.A.; Arsawakulsudhi, Supot; Rukkwamsuk, Theera; Hendriks, Wouter H.

2017-01-01

BACKGROUND: Factorial determination of the sodium (Na) requirement of heat-stressed lactating cows is hindered by accurate estimates of the Na losses through sweat. Direct studies, therefore, may be needed requiring information on the time course of healthy animals to become Na depleted and the

Clues to NaCN formation

Science.gov (United States)

Quintana-Lacaci, G.; Cernicharo, J.; Velilla Prieto, L.; Agúndez, M.; Castro-Carrizo, A.; Fonfría, J. P.; Massalkhi, S.; Pardo, J. R.

2017-11-01

Context. ALMA is providing us essential information on where certain molecules form. Observing where these molecules emission arises from, the physical conditions of the gas, and how this relates with the presence of other species allows us to understand the formation of many species, and to significantly improve our knowledge of the chemistry that occurs in the space. Aims: We studied the molecular distribution of NaCN around IRC +10216, a molecule detected previously, but whose origin is not clear. High angular resolution maps allow us to model the abundance distribution of this molecule and check suggested formation paths. Methods: We modeled the emission of NaCN assuming local thermal equilibrium (LTE) conditions. These profiles were fitted to azimuthal averaged intensity profiles to obtain an abundance distribution of NaCN. Results: We found that the presence of NaCN seems compatible with the presence of CN, probably as a result of the photodissociation of HCN, in the inner layers of the ejecta of IRC +10216. However, similar as for CH3CN, current photochemical models fail to reproduce this CN reservoir. We also found that the abundance peak of NaCN appears at a radius of 3 × 1015 cm, approximately where the abundance of NaCl, suggested to be the parent species, starts to decay. However, the abundance ratio shows that the NaCl abundance is lower than that obtained for NaCN. We expect that the LTE assumption might result in NaCN abundances higher than the real ones. Updated photochemical models, collisional rates, and reaction rates are essential to determine the possible paths of the NaCN formation. Based on observations carried out with ALMA and the IRAM 30 m Telescope. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. IRAM is supported by INSU/CNRS (France

La importancia de evaluar síntomas y alteraciones funcionales en enfermedades neurológicas crónicas: experiencia en cuidado paliativo y rehabilitación en una institución colombiana

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Marta Ximena León-Delgado

2010-01-01

Full Text Available Existe un incremento en la prevalencia de enfermedades neurológicas y su carga de enfermedad. Debido a ello, identificar la frecuencia de síntomas y las alteraciones funcionales es de vital importancia para definir un adecuado plan de tratamiento. Se llevó a cabo un estudio de corte transversal para identificar los síntomas principales y las alteraciones funcionales en pacientes neurológicos de un centro de referencia colombiano para manejo de rehabilitación. Se encontraron como síntomas y alteraciones funcionales más frecuentes: alteraciones de la marcha (65,5%, desórdenes de comunicación (36,98%, alteraciones emocionales y de memoria (38%, dolor (29,45% y alteraciones en las actividades básicas cotidianas (24,3%. El 50% de los pacientes que reportaron dolor, el 30% de los que manifestaron insomnio y el 80% de los que refirieron estreñimiento no recibieron tratamiento en la primera consulta. Algunos de los síntomas identificados no son características que definen la enfermedad, y no siempre son objeto de intervención. Los resultados de este estudio pueden contribuir a reconocer la carga de los síntomas de las enfermedades neurológicas, sensibilizando a los profesionales de la salud acerca de la importancia del cuidado paliativo en pacientes con enfermedades progresivas no oncológicas.

La importancia de la lectura y de las nuevas tecnologías en el aprendizaje del español para inmigrantes

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Francisco José Ortega Segrera

2015-01-01

Full Text Available El presente estudio científico tiene como objetivo considerar el aprendizaje de la lectura en el aula de español para extranjeros y la importancia de las nuevas tecnologías en el fomento del hábito lector de los aprendices. En un primer apartado se reconoce la necesidad del aprendizaje del español como lengua extranjera debido al incremento de la población no nativa en en país y en la UE. Más adelante se detallarán las principales características del reconocimiento de las palabras en los primeros pasos lectores del aprendiz, valorando los distintos métodos y temáticas de lectura en el aula de español para extranjeros. Para finalizar se expone la necesidad de recurrir a las nuevas tecnologías que refuerzan la consecución de los objetivos para la mejora de la comprensión y expresión oral y escrita en el aprendizaje del español como segunda lengua.

The effect of Na+ and K+ on the thermal denaturation of Na+ and + K+-dependent ATPase.

Science.gov (United States)

Fischer, T H

1983-01-01

To increase our understanding of the physical nature of the Na+ and K+ forms of the Na+ + K+-dependent ATPase, thermal-denaturation studies were conducted in different types of ionic media. Thermal-denaturation measurements were performed by measuring the regeneration of ATPase activity after slow pulse exposure to elevated temperatures. Two types of experiments were performed. First, the dependence of the thermal-denaturation rate on Na+ and K+ concentrations was examined. It was found that both cations stabilized the pump protein. Also, K+ was a more effective stabilizer of the native state than was Na+. Secondly, a set of thermodynamic parameters was obtained by measuring the temperature-dependence of the thermal-denaturation rate under three ionic conditions: 60 mM-K+, 150 mM-Na+ and no Na+ or K+. It was found that ion-mediated stabilization of the pump protein was accompanied by substantial increases in activation enthalpy and entropy, the net effect being a less-pronounced increase in activation free energy. PMID:6309139

Financiranje projekata na pomorskom dobru

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Zoran Tasić

2018-02-01

Full Text Available Koncesije otvaraju vrlo osjetljiva politička, ekonomska i pravna pitanja u mnogim državama svijeta. Samo definiranje pojma koncesije često je komplicirana i ne sasvim jasna zadaća. OECD je prihvatila definiciju koncesije kao: ’’davanje prava privatnom trgovačkom društvu da može gospodarski upravljati određenom infrastrukturnim uslugama i za to zarađivati naknadu. Koncesionar dobija u posjed određene objekte (ali vlasništvo na tim objektima ostaje u rukama države te ih koristi u svrhu obavljanja određene djelatnosti ili usluge sukladno odredbama ugovora’’. Hrvatsko pravo definira koncesije načelno kao pravo stečeno temeljem ugovora o koncesiji, a sukladno uvjetima sadržanim u odluci o davanju koncesije (koju je donijelo odgovarajuće upravno tijelo, a u odnosu na pomorsko dobro, specifično, kao pravo državne vlasti da može dio pomorskog dobra, koje je inače dobro izvan pravnog prometa (res extra commercium, isključiti iz opće uporabe bilo dijelom ili u cijelosti, i dati ga fizičkoj ili pravnoj osobi na gospodarsko korištenje sukladno određenim prostornim planovima. Građevine i drugi objekti izgrađeni na pomorskom dobru čine njegov sastavni dio. Zakonom je jasno određeno da nikakva stvarna prava nisu dopuštena na pomorskom dobru, uključivo i na objektima izgrađenima na njemu. Projekti na pomorskom dobru često uključuju velike infrastrukturne projekte, razvoje luka i marina, koji iziskuju značajna financijska sredstva. Banke koje financiraju takve projekte zahtijevaju organiziran i transparentan zakonski okvir koncesija, slobodu ugovaranja, pravnu zaštitu svih strana uključenih u projekt (uključivo i mogućnost međunarodne arbitraže. (...

Controlled phase stability of highly Na-active triclinic structure in nanoscale high-voltage Na2-2xCo1+xP2O7 cathode for Na-ion batteries

Science.gov (United States)

Song, Hee Jo; Kim, Jae-Chan; Dar, Mushtaq Ahmad; Kim, Dong-Wan

2018-02-01

With the increasing demand for high energy density in energy-storage systems, a high-voltage cathode is essential in rechargeable Li-ion and Na-ion batteries. The operating voltage of a triclinic-polymorph Na2CoP2O7, also known as the rose form, is above 4.0 V (vs. Na/Na+), which is relatively high compared to that of other cathode materials. Thus, it can be employed as a potential high-voltage cathode material in Na-ion batteries. However, it is difficult to synthesize a pure rose phase because of its low phase stability, thus limiting its use in high-voltage applications. Herein, compositional-engineered, rose-phase Na2-2xCo1+xP2O7/C (x = 0, 0.1 and 0.2) nanopowder are prepared using a wet-chemical method. The Na2-2xCo1+xP2O7/C cathode shows high electrochemical reactivity with Na ions at 4.0 V, delivering high capacity and high energy density.

IMPORTANCIA DE LA INVESTIGACIÓN EN LA FORMACIÓN DE ESTUDIANTES EN LA MODALIDAD A DISTANCIA

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José Eriberto Cifuentes Medina

2017-06-01

Full Text Available El presente artículo diserta acerca del papel y la importancia de las asignaturas de “Introducción a la investigación” y “Metodología de la investigación” en la formación de tecnólogos, que se ofrece en la modalidad de estudios a distancia. En conclusión, se hace necesaria una reflexión acerca de las generalidades de investigación, normatividad para la presentación de trabajos e informes, y la elaboración, sustentación de proyectos y artículos de investigación como principios fundantes de la proyección en esencia y existencia de la investigación. Las asignaturas mencionadas hacen parte del proceso académico-investigativo y parten de lo que se ha observado en la realidad estudiantil, en los procesos académicos y en la experiencia docente; todo ello con el fin de concretar posibilidades de cambio, acción y trasformación de su labor como regentes en farmacia y administradores del sistema de la salud, teniendo en cuenta las condiciones de la “Educación a distancia” en la que los estudiantes se forman de la mano del aprendizaje autónomo, pero también a la necesidad de acudir a la investigación desde la realidad y contexto que los rodea con bases teóricas consistentes y en aras de ejercer su profesión de una manera eficiente.

Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer

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Rafiza Abdul Razak

2015-05-01

Full Text Available This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA using LUSI (Sidoarjo mud and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced.

Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer

Science.gov (United States)

Abdul Razak, Rafiza; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Ismail, Khairul Nizar; Hardjito, Djwantoro; Yahya, Zarina

2015-01-01

This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced. PMID:26006238

UTJECAJ POZITIVNE DISKRIMINACIJE NA UKLJUČIVANJE ŽENA NA TRŽIŠTE RADA U REPUBLICI HRVATSKOJ

OpenAIRE

Dovranić, Dora; Katavić, Ivica

2016-01-01

U početku 21. stoljeća često se koristi pojam pozitivne (afirmativne) diskriminacije. Pozitivna diskriminacija mjera je koju poduzima vlada, neka organizacija ili korporacija s ciljem da se smanje nejednakosti u društvu nastale upravo diskriminacijom, na način da se pružaju određene povlastice onima koji su pretrpjeli neku vrstu diskriminacije. Nastala je u Sjedinjenim Američkim Državama na inicijativu predsjednika Kennedyja, Johnsona i Nixona. Diskriminacija, nažalost, ima mnogo oblika, a ne...

Importancia de los alcanos en el estudio de los carbones

Directory of Open Access Journals (Sweden)

José E. Sánchez

2010-07-01

Full Text Available Los carbones la Vega, La Vega Oxidado y Tres Bancos, fueron extraídos secuencialmente con los siguientes solventes: H^O, HCl 10%, NaOH 10%, n-Heptano, Éter, Tolueno, Cloroformo, Tetrahidrofurano (THF y Piridina. Se encontraron diferencias significativas en la extractabilidad con THF y Piridina debidas a cambios producidos por la oxidación. Se detectaron n-alcanos de C^ a C^^, en los primeros cuatro extractos con solventes orgánicos. Los perfiles cromatográficos de estos compuestos muestran una distribución dependiente del rango que se mantiene aiin después de la oxidación. Lxis pirocromatogramas de los carbones y de los residuos de extracción se caracterizan por una serie de dobletes de n-1-alqueno/n-alcano cuya distribución también depende del rango de los carbones. Esta característica, atribuible sólo a diferencias en las condiciones geológicas locales, podría utilizarse como indicador del grado de metamorfismo.

Reaction of metal oxides with molten mixtures NaPO3+NaCl

International Nuclear Information System (INIS)

Kovarskaya, E.N.; Mityakhina, V.S.; Rodionov, Yu.I.; Silin, M.Yu.

1988-01-01

By methods of solubility determination and paper chromatography it is shown, that Fe 2 O 3 solution in NaPO 3 +NaCl melts in the air relizes due to its chemical interaction with solvent resulting in formation of iron and sodium binary di- and monophosphates depending on melt-solvent initial composition, its attainment of equilibrium state and experiment temperature. It is established, that oxides increased solubility in melts with NaCl initial content ∼30 mol.% is specified by sodium tri- and tricyclophosphates presence in the melts. On this basis of NGR-spectroscopy data the presence of iron, europium, tin and sodium binary di- and monophosphates in some chloride-polyphosphate melts is confirmed

Crystal structure of polyphosphates NaCd(PO3)3 and NaMn(PO3)3

International Nuclear Information System (INIS)

Murashova, E.V.; Chudinova, N.N.

1997-01-01

Crystal structure of NaCd(PO 3 ) 3 (1) and NaMn(PO 3 ) 3 (2) isostructural polyphosphates was determined for twin samples. Rhombic lattice parameters of (1): a = 14.678, b = 14.669, c = 14.705 A, sp. gr. P2 1 2 1 2 1 , Z = 16. The structure of compounds is of frame type. Polyphosphate chain with repetition period of 24 PO 4 tetrahedrons contacts with NaO 6 and M 2 O 6 octahedrons by means of common oxygen vertices. Similarities and differences in structure of mentioned polyphosphates and earlier analyzed NaMg(PO 3 ) 3 polyphosphate are noted [ru

Effect of growth in lithium on ouabain binding, Na-K-ATPase and Na and K transport in hela cells.

Science.gov (United States)

Boardman, L J; Hume, S P; Lamb, J F; Polson, J

1975-01-01

1. HeLa cells were grown for 24 hr in growth medium in which part of the Na was replaced with Li. Ion contents, cell volumes and numbers, Na-K-ATPase and specific ouabain binding were measured. In some experiments the Na efflux and net Na transport was also measured. 2. Growth in Li caused a rise in the specific ouabain binding and membrane Na-K-ATPase of these cells. The Li concentrations in the cells necessary to produce this effect ranged up to 50 mM. 3. It is suggested that Li, like Na, acts on the genetic material of the cells to cause the production of more Na pumps within the membrane. PMID:124350

Effects of EDTA-Na (Na ethylenediaminetetraacetate) upon the metabolism of radiostrontium and radioyttrium in mice

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, T; Wakisaka, G; Kono, T; Hiroaki, A; Yamamasu, T; Sugawa, I

1954-01-01

The toxicity of EDTA-Na, inert Sr (NO/sub 3/)/sub 2/ and Ba (NO/sub 3/)/sub 2/ has been examined. Simultaneous injection of EDTA-Na showed no significant effect upon the distribution of radio-Sr in the bones of mice. The distribution of radio-Y in the bones of mice tended to decrease following the simultaneous subcutaneous injection of /sup 91/Y and EDTA-Na.

Bases teóricas que sustentan la importancia del trabajo independiente en la educación médica superior

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Mercedes Caridad García González

Full Text Available El objetivo del trabajo fue fundamentar las bases teóricas que sustentan la importancia del trabajo independiente en el proceso de enseñanza aprendizaje en la Educación Médica Superior, así como aspectos relativos a su concepción, requerimientos y formas de aplicación. Se realizó un estudio bibliográfico acerca del tema y se llegó a las siguientes conclusiones: el trabajo independiente es un medio de organizar metodológicamente la actividad cognoscitiva independiente de los estudiantes que se expresa a través de un conjunto de tareas y puede utilizarse durante la actividad docente y fuera de ella, así como en cualquiera de las formas de organización de que se trate. Es imprescindible que se tengan en cuenta al organizar el trabajo independiente las etapas de la actividad humana: planificación, orientación, ejecución y control. El trabajo independiente es un factor importante para estimular la independencia de los futuros profesionales de las Ciencias Médicas por lo que su perfeccionamiento exige al profesor una alta profesionalización de sus acciones.

Aspectos metodológicos en la medición del consumo de alcohol: la importancia de los patrones de consumo

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José L. Valencia Martín

2014-01-01

Full Text Available Medir correctamente el consumo de alcohol es fundamental para in vestigar de forma fiable sus efectos en salud. Sin embargo, esta estima ción resulta enormemente compleja, tanto por la diversidad de formas de consumo de alcohol existente como por la gran heterogeneidad en su cla sificación. Además, cada patrón de consumo de alcohol puede asociarse a efectos muy diferentes sobre la salud, por lo que no tenerlos en conside ración cuando estimamos la ingesta de alcohol puede ocultar o confundir su importancia en estos efectos. Todo ello dificulta las comparaciones en tre estudios y el establecimiento de asociaciones consistentes que permi tan comprender los verdaderos efectos del consumo de alcohol, tanto glo bales como específicos de cada patrón de bebida. Este trabajo revisa los principales métodos y fuentes de información disponibles en España para estimar los aspectos más relevantes del consumo de alcohol, así como las dificultades y problemas metodológicos más frecuentes en la medición y clasificación de cada uno de estos indicadores.

Novel aspects of Na+,K+-ATPase

OpenAIRE

Aizman, Oleg

2002-01-01

Na,K-ATPase, an integral membrane protein expressed in each eukaryotic cell, serves as the major determinant of intracellular ion composition. In the current study we investigated novel aspects of Na,K-ATPase function and regulation. It is well established that Na,K-ATPase activity is regulated by reversible phosphorylation. New findings in this study are: 1) the level of intracellular Ca 2. concentration determines the functional effects of PKA and PKC-mediated Na,K-ATP...

High-Performance Na-O2 Batteries Enabled by Oriented NaO2 Nanowires as Discharge Products.

Science.gov (United States)

Khajehbashi, S Mohammad B; Xu, Lin; Zhang, Guobin; Tan, Shuangshuang; Zhao, Yan; Wang, Lai-Sen; Li, Jiantao; Luo, Wen; Peng, Dong-Liang; Mai, Liqiang

2018-06-13

Na-O 2 batteries are emerging rechargeable batteries due to their high theoretical energy density and abundant resources, but they suffer from sluggish kinetics due to the formation of large-size discharge products with cubic or irregular particle shapes. Here, we report the unique growth of discharge products of NaO 2 nanowires inside Na-O 2 batteries that significantly boosts the performance of Na-O 2 batteries. For this purpose, a high-spin Co 3 O 4 electrocatalyst was synthesized via the high-temperature oxidation of pure cobalt nanoparticles in an external magnetic field. The discharge products of NaO 2 nanowires are 10-20 nm in diameter and ∼10 μm in length, characteristics that provide facile pathways for electron and ion transfer. With these nanowires, Na-O 2 batteries have surpassed 400 cycles with a fixed capacity of 1000 mA h g -1 , an ultra-low over-potential of ∼60 mV during charging, and near-zero over-potential during discharging. This strategy not only provides a unique way to control the morphology of discharge products to achieve high-performance Na-O 2 batteries but also opens up the opportunity to explore growing nanowires in novel conditions.

Insight to the Thermal Decomposition and Hydrogen Desorption Behaviors of NaNH2-NaBH4 Hydrogen Storage Composite.

Science.gov (United States)

Pei, Ziwei; Bai, Ying; Wang, Yue; Wu, Feng; Wu, Chuan

2017-09-20

The lightweight compound material NaNH 2 -NaBH 4 is regarded as a promising hydrogen storage composite due to the high hydrogen density. Mechanical ball milling was employed to synthesize the composite NaNH 2 -NaBH 4 (2/1 molar ratio), and the samples were investigated utilizing thermogravimetric-differential thermal analysis-mass spectroscopy (TG-DTA-MS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses. The full-spectrum test (range of the ratio of mass to charge: 0-200) shows that the released gaseous species contain H 2 , NH 3 , B 2 H 6 , and N 2 in the heating process from room temperature to 400 °C, and possibly the impurity gas B 6 H 12 also exists. The TG/DTA analyses show that the composite NaNH 2 -NaBH 4 (2/1 molar ratio) is conductive to generate hydrogen so that the dehydrogenation process can be finished before 400 °C. Moreover, the thermal decomposition process from 200 to 400 °C involves two-step dehydrogenation reactions: (1) Na 3 (NH 2 ) 2 BH 4 hydride decomposes into Na 3 BN 2 and H 2 (200-350 °C); (2) remaining Na 3 (NH 2 ) 2 BH 4 reacts with NaBH 4 and Na 3 BN 2 , generating Na, BN, NH 3 , N 2 , and H 2 (350-400 °C). The better mechanism understanding of the thermal decomposition pathway lays a foundation for tailoring the hydrogen storage performance of the composite complex hydrides system.

Distinct pH dependencies of Na+/K+ selectivity at the two faces of Na,K-ATPase.

Science.gov (United States)

Cornelius, Flemming; Tsunekawa, Naoki; Toyoshima, Chikashi

2018-02-09

The sodium pump (Na,K-ATPase) in animal cells is vital for actively maintaining ATP hydrolysis-powered Na + and K + electrochemical gradients across the cell membrane. These ion gradients drive co- and countertransport and are critical for establishing the membrane potential. It has been an enigma how Na,K-ATPase discriminates between Na + and K + , despite the pumped ion on each side being at a lower concentration than the other ion. Recent crystal structures of analogs of the intermediate conformations E2·Pi·2K + and Na + -bound E1∼P·ADP suggest that the dimensions of the respective binding sites in Na,K-ATPase are crucial in determining its selectivity. Here, we found that the selectivity at each membrane face is pH-dependent and that this dependence is unique for each face. Most notable was a strong increase in the specific affinity for K + at the extracellular face ( i.e. E2 conformation) as the pH is lowered from 7.5 to 5. We also observed a smaller increase in affinity for K + on the cytoplasmic side (E1 conformation), which reduced the selectivity for Na + Theoretical analysis of the p K a values of ion-coordinating acidic amino acid residues suggested that the face-specific pH dependences and Na + /K + selectivities may arise from the protonation or ionization of key residues. The increase in K + selectivity at low pH on the cytoplasmic face, for instance, appeared to be associated with Asp 808 protonation. We conclude that changes in the ionization state of coordinating residues in Na,K-ATPase could contribute to altering face-specific ion selectivity. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Protozoarios parásitos de importancia en salud pública transportados por Musca domestica Linnaeus en Lima, Perú

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Martín Cárdenas

2013-06-01

Full Text Available El presente trabajo investiga los protozoarios parásitos de importancia para la salud pública transportados por Musca domestica. El estudio se llevó a cabo entre los meses de junio y diciembre de 1998, en los distritos de Comas y San Juan de Lurigancho de la provincia de Lima. Se estudiaron 3014 moscas colectadas en la basura acumulada en la vía pública de los pueblos jóvenes de los distritos mencionados. Las capturas se agruparon en lotes constituidos por un promedio de 30 moscas. Se estudiaron un total de 100 lotes. Las moscas fueron disecadas y procesadas con agua destilada estéril para obtener un macerado intestinal. Para la observación de los parásitos se utilizó el método directo simple y la coloración tricrómica de Gomori ácido resistente modificado. Se encontraron los siguientes protozoarios que parasitan al hombre: Blastocystis hominis (9,0%, Giardia lamblia (3,0%, Cryptosporidium sp. (2,0%, Cyclospora cayetanensis (1,0%, Iodamoeba bütschlii (17,0%, Endolimax nana (5,0% y Chilomastix mesnili (3,0%. Se reporta por primera vez para el Perú a B. hominis y Cyclospora cayetanensis en M. domestica.

OGLAŠEVANJE NA FACEBOOKU

OpenAIRE

Renko, Katica

2013-01-01

V magistrskem delu smo se seznanili z oglaševanjem na Facebooku. S pregledom gradiva, ki nam je ponujeno, smo preverili pogoje, načine, oblike … oglaševanja, ki pa smo jih s pregledom situacije v praksi preverili in dopolnili. Ob zaključku dela lahko rečemo, da je oglaševanje preko FB enostavnejše, cenejše, dostopnejše, omogoča nam ažurnost in samo komunikacijo z naslovniki, ki so potencialni kupci naših ponudb. Množični mediji nam omogočajo mnogotero obliko oglaševanja. Izbrana oblika ponuja...

La importancia de la fisiología en la distribución geográfica de los insectos

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Gerardo J. DE LA VEGA

2015-01-01

Full Text Available Hallar la explicación de los patrones de distribución de especies a gran escala es un tema muy importante en ecología. Existen muchos trabajos mostrando correlaciones entre factores abióticos, latitud y/o altitud y distribución de especies. Sin embargo, este tipo de estudios fallan en encontrar relaciones causales y mecanismos involucrados en explicar el fenómeno de distribución de las especies. En este foro se presenta una pequeña introducción a la macrofisiología. Un área de trabajo creada en los últimos 10 o 15 años, que sintetiza la conjunción de la macroecología con la fisiología ambiental o ecofisiología, la cual permite un acercamiento mecanístico a la explicación de patrones de distribución de especies. Los insectos son un grupo ideal para utilizar este enfoque debido a su amplia distribución, facilidades para la cría y para realizar experimentos. En particular un enfoque macrofisiológico ayudaría a mejorar las predicciones de distribución actual y futura de las especies frente al cambio climático global, punto de crucial importancia particularmente en insectos invasores, aquellos considerados plaga o vectores de enfermedades.

Laser-induced ionization of Na vapor

International Nuclear Information System (INIS)

Wu, R.C.Y.; Judge, D.L.; Roussel, F.; Carre, B.; Breger, P.; Spiess, G.

1982-01-01

The production of Na 2 + ions by off-resonant laser excitation in the 5800-6200A region mainly results from two-photon absorption by the Na 2 molecule to highly excited gerade states followed by (a) direct ionization by absorbing a third photon or (b) coupling to the molecular Na 2 D 1 PIμ Rydberg state which is subsequently ionized by absorbing a third photon. This mechanism, i.e., a two-photon resonance three photon ionization process, explains a recent experimental observation of Roussel et al. It is suggested that the very same mechanism is also responsible for a similar observation reported by Polak-Dingels et al in their work using two crossed Na beams. In the latter two studies the laser-induced associative ionization processes were reported to be responsible for producing the Na 2 + ion. From the ratio of molecular to atomic concentration in the crossed beam experiment of Polak-Dingels et al we estimate that the cross section for producing Na 2 + through laser-induced associative ionization is at least four orders of magnitude smaller than ionization through the two-photon resonance three photon ionization process in Na 2 molecules

La importancia e invisibilidad de las enfermeras en Atención Primaria de Salud The importance and invisibility of the nurses

Directory of Open Access Journals (Sweden)

Rafael Serrano-del-Rosal

2010-03-01

Full Text Available Los estudios realizados para medir la calidad de un servicio sanitario, muestran que la satisfacción del paciente es un instrumento importante para evaluar aquélla y el funcionamiento real de dicho servicio. La información que aportan puede ser una buena guía para los políticos o gestores encargados del diseño y puesta en práctica de programas orientados a aumentar la calidad y eficacia sin olvidar a una parte fundamental: sus usuarios. En este contexto se enmarca un proyecto de investigación que se lleva a cabo en el Instituto de Estudios Sociales Avanzados del Consejo Superior de Investigaciones Científicas en colaboración con el Servicio Andaluz de Salud. Bajo este marco, el objetivo de este trabajo es conocer la importancia que tiene la satisfacción de los usuarios con los profesionales de enfermería, en el conjunto de su satisfacción con el servicio sanitario recibido. Para ello, se exponen los resultados de un riguroso análisis con los datos del estudio de satisfacción del usuario de Atención Primaria del año 2008. Se plantea la siguiente paradoja, los usuarios están claramente satisfechos con los enfermeros, con un porcentaje por encima del resto de los profesionales, sin embargo, cuando dichos usuarios conforman su satisfacción global con el servicio recibido, la importancia de estos profesionales disminuye notablemente centrándose principalmente en el papel de los médicos.The studies carried out to measure the quality of the health services show patient satisfaction as an important tool to evaluate the actual running of the service and its quality. This information can be a good guide in the design and implementation of health programs aimed at increasing their quality and efficiency for policy makers and managers. In this context, the aim is to know the importance of user satisfaction with nursing professionals in all of their overall satisfaction with the health service received. An empirical study is been

Characterization and antibacterial activity of silver exchanged regenerated NaY zeolite from surfactant-modified NaY zeolite

Energy Technology Data Exchange (ETDEWEB)

Salim, Mashitah Mad; Malek, Nik Ahmad Nizam Nik, E-mail: niknizam@fbb.utm.my

2016-02-01

The antibacterial activity of regenerated NaY zeolite (thermal treatment from cetyltrimethyl ammonium bromide (CTAB)-modified NaY zeolite and pretreatment with Na ions) loaded with silver ions were examined using the broth dilution minimum inhibitory concentration (MIC) method against Escherichia coli (E. coli ATCC 11229) and Staphylococcus aureus (S. aureus ATCC 6538). X-ray diffraction (XRD), attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and chemical elemental analyses were used to characterize the regenerated NaY and AgY zeolites. The XRD patterns indicated that the calcination and addition of silver ions on regenerated NaY zeolite did not affect the structure of the regenerated NaY zeolite as the characteristic peaks of the NaY zeolite were retained, and no new peaks were observed. The regenerated AgY zeolite showed good antibacterial activity against both bacteria strains in distilled water, and the antibacterial activity of the samples increased with increasing Ag loaded on the regenerated AgY zeolite; the regenerated AgY zeolite was more effective against E. coli than S. aureus. However, the antibacterial activity of the regenerated AgY was not effective in saline solution for both bacteria. The study showed that CTAB-modified NaY zeolite materials could be regenerated to NaY zeolite using thermal treatment (550 °C, 5 h) and this material has excellent performance as an antibacterial agent after silver ions loading. - Highlights: • Thermal treatment was used to regenerate surfactant modified zeolite. • The regenerated NaY zeolite formed was added with different silver loadings. • Regenerated AgY zeolite was tested for antibacterial activity on E. coli and S. aureus. • The antibacterial activity increased with increased of the amount of silver loadings. • The zeolite structure did not change with thermal and modification

Characterization and antibacterial activity of silver exchanged regenerated NaY zeolite from surfactant-modified NaY zeolite

International Nuclear Information System (INIS)

Salim, Mashitah Mad; Malek, Nik Ahmad Nizam Nik

2016-01-01

The antibacterial activity of regenerated NaY zeolite (thermal treatment from cetyltrimethyl ammonium bromide (CTAB)-modified NaY zeolite and pretreatment with Na ions) loaded with silver ions were examined using the broth dilution minimum inhibitory concentration (MIC) method against Escherichia coli (E. coli ATCC 11229) and Staphylococcus aureus (S. aureus ATCC 6538). X-ray diffraction (XRD), attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and chemical elemental analyses were used to characterize the regenerated NaY and AgY zeolites. The XRD patterns indicated that the calcination and addition of silver ions on regenerated NaY zeolite did not affect the structure of the regenerated NaY zeolite as the characteristic peaks of the NaY zeolite were retained, and no new peaks were observed. The regenerated AgY zeolite showed good antibacterial activity against both bacteria strains in distilled water, and the antibacterial activity of the samples increased with increasing Ag loaded on the regenerated AgY zeolite; the regenerated AgY zeolite was more effective against E. coli than S. aureus. However, the antibacterial activity of the regenerated AgY was not effective in saline solution for both bacteria. The study showed that CTAB-modified NaY zeolite materials could be regenerated to NaY zeolite using thermal treatment (550 °C, 5 h) and this material has excellent performance as an antibacterial agent after silver ions loading. - Highlights: • Thermal treatment was used to regenerate surfactant modified zeolite. • The regenerated NaY zeolite formed was added with different silver loadings. • Regenerated AgY zeolite was tested for antibacterial activity on E. coli and S. aureus. • The antibacterial activity increased with increased of the amount of silver loadings. • The zeolite structure did not change with thermal and modification

Carbon dioxide sequestration using NaHSO4 and NaOH: A dissolution and carbonation optimisation study.

Science.gov (United States)

Sanna, Aimaro; Steel, Luc; Maroto-Valer, M Mercedes

2017-03-15

The use of NaHSO 4 to leach out Mg fromlizardite-rich serpentinite (in form of MgSO 4 ) and the carbonation of CO 2 (captured in form of Na 2 CO 3 using NaOH) to form MgCO 3 and Na 2 SO 4 was investigated. Unlike ammonium sulphate, sodium sulphate can be separated via precipitation during the recycling step avoiding energy intensive evaporation process required in NH 4 -based processes. To determine the effectiveness of the NaHSO 4 /NaOH process when applied to lizardite, the optimisation of the dissolution and carbonation steps were performed using a UK lizardite-rich serpentine. Temperature, solid/liquid ratio, particle size, concentration and molar ratio were evaluated. An optimal dissolution efficiency of 69.6% was achieved over 3 h at 100 °C using 1.4 M sodium bisulphate and 50 g/l serpentine with particle size 75-150 μm. An optimal carbonation efficiency of 95.4% was achieved over 30 min at 90 °C and 1:1 magnesium:sodium carbonate molar ratio using non-synthesised solution. The CO 2 sequestration capacity was 223.6 g carbon dioxide/kg serpentine (66.4% in terms of Mg bonded to hydromagnesite), which is comparable with those obtained using ammonium based processes. Therefore, lizardite-rich serpentinites represent a valuable resource for the NaHSO 4 /NaOH based pH swing mineralisation process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization and antibacterial activity of silver exchanged regenerated NaY zeolite from surfactant-modified NaY zeolite.

Science.gov (United States)

Salim, Mashitah Mad; Malek, Nik Ahmad Nizam Nik

2016-02-01

The antibacterial activity of regenerated NaY zeolite (thermal treatment from cetyltrimethyl ammonium bromide (CTAB)-modified NaY zeolite and pretreatment with Na ions) loaded with silver ions were examined using the broth dilution minimum inhibitory concentration (MIC) method against Escherichia coli (E. coli ATCC 11229) and Staphylococcus aureus (S. aureus ATCC 6538). X-ray diffraction (XRD), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and chemical elemental analyses were used to characterize the regenerated NaY and AgY zeolites. The XRD patterns indicated that the calcination and addition of silver ions on regenerated NaY zeolite did not affect the structure of the regenerated NaY zeolite as the characteristic peaks of the NaY zeolite were retained, and no new peaks were observed. The regenerated AgY zeolite showed good antibacterial activity against both bacteria strains in distilled water, and the antibacterial activity of the samples increased with increasing Ag loaded on the regenerated AgY zeolite; the regenerated AgY zeolite was more effective against E. coli than S. aureus. However, the antibacterial activity of the regenerated AgY was not effective in saline solution for both bacteria. The study showed that CTAB-modified NaY zeolite materials could be regenerated to NaY zeolite using thermal treatment (550°C, 5h) and this material has excellent performance as an antibacterial agent after silver ions loading. Copyright © 2015 Elsevier B.V. All rights reserved.

Composition and thermochemistry of the equilibrium vapour of the systems NaI-FeI2 and NaI-PbI2

International Nuclear Information System (INIS)

Hilpert, K.; Gerads, H.; Koberts, D.; Miller, M.

1987-01-01

The vaporization of NaI/FeI 2 and NaI/PbI 2 samples of equimolar composition was investigated was investigated in the temperature ranges between 574 to 683 K and 562 to 669 K, respectively, by using the mass spectrometric Knudsen effusion method. The gaseous species I, I 2 , NaI, (NaI) 2 , FeI 2 , (FeI 2 ) 2 , FeI 3 , NaFeI 3 , and Na 2 FeI 4 (NaI-FeI 2 system) as well as NaI, (NaI) 2 , PbI 2 , (PbI 2 ) 2 , and NaPbI 3 (NaI-PbI 2 system) are present in the equilibrium vapours. The equilibrium partial pressures of these species were determined with the exception of I, I 2 , and FeI 3 . Enthalpies and entropies of dissociation resulted for the reactions NaFeI 3 (g) ↔ NaI(g)+FeI 2 (g) (1), Na 2 FeI 4 (g) ↔ 2NaI(g)+FeI 2 (g) and (2) NaPbI 3 (g) ↔ NaI(g)+PbI 2 (g) (3) as Δ d H 298 0 (Eq. (1)) = 184±5 kJ mol -1 , Δ d S 298 0 (Eq. (1)) = 143±8 J mol -1 K -1 ; Δ d H 298 0 (Eq. (2)) = 333±9 kJ mol -1 , Δ d S 298 0 (Eq. (2)) = 274±14 J mol -1 K -1 ; and Δ d H 298 0 (Eq. (3)) = 168±5 kJ mol -1 , Δ d S 298 0 (Eq. (3)) = 151±9 J mol -1 K -1 . Equilibrium constants for these reactions are additionally given. The pressures of NaFeI 3 (g) and NaPbI 3 (g) as all as their enthalpies of dissociation are discussed with respect to their significance of semi empirical rules. (orig.)

Adsorption and Formation of Small Na Clusters on Pristine and Double-Vacancy Graphene for Anodes of Na-Ion Batteries.

Science.gov (United States)

Liang, Zhicong; Fan, Xiaofeng; Zheng, Weitao; Singh, David J

2017-05-24

Layered carbon is a likely anode material for Na-ion batteries (NIBs). Graphitic carbon has a low capacity of approximately 35 (mA h)/g due to the formation of NaC 64 . Using first-principles methods including van der Waals interactions, we analyze the adsorption of Na ions and clusters on graphene in the context of anodes. The interaction between Na ions and graphene is found to be weak. Small Na clusters are not stable on the surface of pristine graphene in the electrochemical environment of NIBs. However, we find that Na ions and clusters can be stored effectively on defected graphene that has double vacancies. In addition, the adsorption energy of small Na clusters near a double vacancy is found to decrease with increasing cluster size. With high concentrations of vacancies the capacity of Na on defective graphene is found to be as much as 10-30 times higher than that of graphitic carbon.

Novel regulation of cardiac Na pump via phospholemman.

Science.gov (United States)

Pavlovic, Davor; Fuller, William; Shattock, Michael J

2013-08-01

As the only quantitatively significant Na efflux pathway from cardiac cells, the Na/K ATPase (Na pump) is the primary regulator of intracellular Na. The transmembrane Na gradient it establishes is essential for normal electrical excitability, numerous coupled-transport processes and, as the driving force for Na/Ca exchange, thus setting cardiac Ca load and contractility. As Na influx varies with electrical excitation, heart rate and pathology, the dynamic regulation of Na efflux is essential. It is now widely recognized that phospholemman, a 72 amino acid accessory protein which forms part of the Na pump complex, is the key nexus linking cellular signaling to pump regulation. Phospholemman is the target of a variety of post-translational modifications (including phosphorylation, palmitoylation and glutathionation) and these can dynamically alter the activity of the Na pump. This review summarizes our current understanding of the multiple regulatory mechanisms that converge on phospholemman and govern NA pump activity in the heart. The corrected Fig. 4 is reproduced below. The publisher would like to apologize for any inconvenience caused. [corrected]. Copyright © 2013. Published by Elsevier Ltd.

Mousse photochemistry formation; Formacao fotoquimica de mousse

Energy Technology Data Exchange (ETDEWEB)

Rangel, George W.M.; Nicodem, David E. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica]. E-mail: gwallace_iq@yahoo.com.br; nicodem@iq.ufrj.br

2003-07-01

The petroleum, when spilled in the sea it forms an emulsion of water in oil could contain up to 90% of water. This emulsion, called Mousse of Chocolate, it can be very stable, taking to the increase of the environmental impact and impeding the microbiological degradation. It was observed that the petroleum, when irradiated with solar light, it forms Mousse more easily. However, same being known about the importance of the action of the light in the formation of Mousse, little it is known regarding the processes and conditions involved in the formation of Mousse. This project proposes the study of the process of formation of Mousse, in function of the suffered transformations for petroleum after solar irradiation. We will study the relationship between the stability and formation of Mousse and the present amount of asphaltenes in the petroleum as a result of the irradiation. We will develop a methodology for analysis of emulsions of water in petroleum, in way we know her/it the stability of the emulsion in function of the time and the amount of water in the same. We will study the behavior of a sample of Brazilian petroleum of Campos' Basin, already used in other photochemistry studies. We will analyze the effect of the time of irradiation in the asphaltenes formation and Mousse. We will also analyze other types of petroleum, for us to compare results with obtained them in the Brazilian petroleum. (author)

All new for NA62

CERN Multimedia

Antonella Del Rosso

2012-01-01

This week sees the start of the first run of the new NA62 experiment. This will be a unique opportunity for the collaboration to test its new beam, new detectors and new data acquisition system before the physics run in 2014. Speaking to the Bulletin, the NA62 technical coordinator Ferdinand Hahn shares the many challenges that the various teams faced to be on time for beam. Ready, steady, start!   A Large Angle Veto detector (white) in place in the NA62 decay volume (blue). With components from almost all the detectors in place downstream of the decay point of the mother particles – the kaons – and of the KTAG detector that tags the kaons before they decay, NA62 is ready for its first technical run. This unique run will test all the equipment as well as the trigger and the data acquisition systems. “This year, we will have about five weeks of beam from the SPS before the long shutdown of all the CERN machines,” says Ferdinand Hahn, NA62 Technical Co-...

Effect of chloride substitution on the order–disorder transition in NaBH4 and Na11BD4

International Nuclear Information System (INIS)

Olsen, Jørn Eirik; Karen, Pavel; Sørby, Magnus H.; Hauback, Bjørn C.

2014-01-01

Graphical abstract: Interactions that order the BD 4 - tetrahedra below the order–disorder transition became increasingly frustrated by the solute in the Na( 11 BD 4 ) 1−x Cl x solid solutions, and the order disappears at x = 0.158. Highlights: • The order–disorder transition temperature for Na(BH 4 ) 1−x Cl x and Na( 11 BD 4 ) 1−x Cl x is highly dependent on the Cl-content, x. • The transition is characterized by DSC for Na( 11 BD 4 ) 1−x Cl x for x = 0, 0.10 and 0.15. • No transition is observed for x ⩾ 0.20 on cooling to 8 K. • The crystal structures are reported for Na 11 BD 4 at room temperature and 8 K and Na( 11 BD 4 ) 1−x Cl x (x = 0.10, 0.15, 0.20 and 0.25) at 8 K from powder neutron diffraction. -- Abstract: Phase transition associated with anion disordering over two orientations in Na 11 BD 4 (NaBH 4 ) and its solid solutions with NaCl, Na( 11 BD 4 ) 1−x Cl x , is investigated with powder diffraction (neutron and synchrotron radiation), differential scanning calorimetry and Raman spectroscopy. Upon heating, the transition temperature extrapolated to zero rate of heating is 192.2 K for Na 11 BD 4 , ΔS = 4.41 J/mol K, hysteresis 1.7 K and the volume increase 0.43%. Thermal parameters of the transition in Na( 11 BD 4 ) 1−x Cl x follow a colligative-property model of an ideal solution, with x = 0.158(1) as the critical concentration at which the ordering interactions and the transition itself are eliminated. On approaching this limit, the tetragonal distortion of the ordered structure decreases somewhat towards the cubic average, and this is associated with a partial disorder of the tetrahedral anions seen by diffraction methods. In fact, a 3% disorder is already present in the pure solvent of the solid solution (Na 11 BD 4 ) at 8 K

PARP-1 como regulador del ciclo celular

OpenAIRE

Iglesias Vázquez, Pablo

2015-01-01

En el presente estudio hemos querido investigar las implicaciones biológicas de la interacción PARP-1/E2F-1 en escenarios en los que el factor de transcripción E2F-1 resulta de gran importancia como son el desarrollo embrionario y la oncogénesis. En este respecto, hemos demostrado que tanto PJ34, inhibidor de la actividad enzimática de PARP, como gosipol, inhibidor de las interacciones proteína-proteína, son capaces de reducir la actividad transcripcional de E2F-1 y la proli...

Neutron diffraction studies of the Na-ion battery electrode materials NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3}

Energy Technology Data Exchange (ETDEWEB)

Yahia, H. Ben [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha (Qatar); Essehli, R., E-mail: ressehli@qf.org.qa [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha (Qatar); Avdeev, M. [Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights NSW 2234 (Australia); Park, J-B.; Sun, Y-K. [Department of Energy Engineering Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Al-Maadeed, M.A. [Center for Advanced Materials (CAM), Qatar University, 2713 Doha (Qatar); Belharouak, I., E-mail: ibelharouak@qf.org.qa [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha (Qatar)

2016-06-15

The new compounds NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} were synthesized by sol-gel method and their crystal structures were determined by using neutron powder diffraction data. These compounds were characterized by galvanometric cycling and cyclic voltammetry. NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} crystallize with a stuffed α-CrPO{sub 4}-type structure. The structure consists of a 3D-framework made of octahedra and tetrahedra that are sharing corners and/or edges generating channels along [100] and [010], in which the sodium atoms are located. Of significance, in the structures of NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} a statistical disorder Ni{sup 2+}/Cr{sup 3+} was observed on both the 8g and 4a atomic positions, whereas in NaCoCr{sub 2}(PO{sub 4}){sub 3} the statistical disorder Co{sup 2+}/Cr{sup 3+} was only observed on the 8g atomic position. When tested as negative electrode materials, NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} delivered specific capacities of 352, 385, and 368 mA h g{sup −1}, respectively, which attests to the electrochemical activity of sodium in these compounds. - Highlights: • NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} were synthesized by sol-gel method. • The crystal structures were determined by using neutron powder diffraction data. • The three compounds crystallize with a stuffed α-CrPO{sub 4}-type structure. • The three compounds were tested as anodes in sodium-ion batteries. • Relatively high specific capacities were obtained for these compounds.

Evaluation of NaX and NaY packed beds for chromium uptake from multicomponent solution

Directory of Open Access Journals (Sweden)

Maria Angélica Simões Dornellas de Barros

2014-04-01

Full Text Available In this paper the removal of chromium from Cr/Ca/Mg/K and Cr/Ca/Mg/K/Na solutions was investigated in NaX and NaY packed beds. The breakthrough curves presented some overshooting phenomena where chromium ions displaced the previous exchanged cations. Length of unused bed, overall mass transfer coefficient, operational ratio and dimensionless variance were obtained. According to such mass transfer parameters it was concluded that the chromium uptake is influenced by the competition and interaction of the entering ions. Such influences were verified through some differences in the dynamic selectivity obtained for each system. NaY seemed to have a higher affinity towards Cr3+ and its sites were more efficiently used in the ion exchange process.

Water transport by the renal Na(+)-dicarboxylate cotransporter

DEFF Research Database (Denmark)

Meinild, A K; Loo, D D; Pajor, A M

2000-01-01

. This solute-coupled influx of water took place in the absence of, and even against, osmotic gradients. There was a strict stoichiometric relationship between Na(+), substrate, and water transport of 3 Na(+), 1 dicarboxylate, and 176 water molecules/transport cycle. These results indicate that the renal Na......This study investigated the ability of the renal Na(+)-dicarboxylate cotransporter, NaDC-1, to transport water. Rabbit NaDC-1 was expressed in Xenopus laevis oocytes, cotransporter activity was measured as the inward current generated by substrate (citrate or succinate), and water transport...... was monitored by the changes in oocyte volume. In the absence of substrates, oocytes expressing NaDC-1 showed an increase in osmotic water permeability, which was directly correlated with the expression level of NaDC-1. When NaDC-1 was transporting substrates, there was a concomitant increase in oocyte volume...

Pioneering instrumentation aspects of NA60

International Nuclear Information System (INIS)

David, Andre

2004-01-01

NA60 is taking data with proton and heavy-ion beams at the CERN SPS. Although building up on previous experiments, the dimuon physics programme of NA60 places very demanding requirements on its new detectors, in terms of radiation tolerance, granularity and read-out electronics speed. We start by comparing dimuon detection strategies in NA60 with those of previous experiments. We then describe the new detectors used in NA60, placing particular emphasis on their technological pioneering aspects as well as on their contributions to the overall physics performance of the experiment

Occlusion of 22Na+ and 86Rb+ in membrane-bound and soluble protomeric alpha beta-units of Na,K-ATPase

International Nuclear Information System (INIS)

Vilsen, B.; Andersen, J.P.; Petersen, J.; Jorgensen, P.L.

1987-01-01

In this work, we examined occlusion of 22 Na+ and 86 Rb+ in membranous and detergent-solubilized Na,K-ATPase from outer renal medulla. Optimum conditions for occlusion of 22 Na+ were provided by formation of the phosphorylated complex from the beta,gamma-bidentate complex of chromium (III) with ATP (CrATP). Release of occluded cations occurred at equally slow rates in soluble and membrane-bound Na,K-ATPase. Values of 22 Na+ occlusion as high as 11 nmol/mg of protein were measured, corresponding to 1.8-2.7 mol of Na+/mol of phosphorylated Na,K-ATPase as determined by 32 P incorporation from [gamma- 32 P]CrATP. Maximum capacity for phosphorylation from [gamma- 32 P]CrATP was 6 nmol/mg of protein and equal to capacities for binding of [48V]vanadate and [ 3 H]ouabain. The stoichiometry for occlusion of Rb+ was close to 2 Rb+ ions/phosphorylation site. In an analytical ultracentrifuge, the soluble Na+- or Rb+-occluded complexes showed sedimentation velocities (S20,w = 6.8-7.4) consistent with monomeric alpha beta-units. The data show that soluble monomeric alpha beta-units of Na,K-ATPase can occlude Rb+ or Na+ with the same stoichiometry as the membrane-bound enzyme. The structural basis for occlusion of cations in Na,K-ATPase is suggested to be the formation of a cavity inside a monomeric alpha beta-unit constituting the minimum protein unit required for active Na,K-transport

Transcriptional regulators of Na, K-ATPase subunits

Directory of Open Access Journals (Sweden)

Zhiqin eLi

2015-10-01

Full Text Available The Na,K-ATPase classically serves as an ion pump creating an electrochemical gradient across the plasma membrane that is essential for transepithelial transport, nutrient uptake and membrane potential. In addition, Na,K-ATPase also functions as a receptor, a signal transducer and a cell adhesion molecule. With such diverse roles, it is understandable that the Na,K-ATPase subunits, the catalytic alpha-subunit, the beta-subunit and the FXYD proteins, are controlled extensively during development and to accommodate physiological needs. The spatial and temporal expression of Na,K-ATPase is partially regulated at the transcriptional level. Numerous transcription factors, hormones, growth factors, lipids and extracellular stimuli modulate the transcription of the Na,K-ATPase subunits. Moreover, epigenetic mechanisms also contribute to the regulation of Na,K-ATPase expression. With the ever growing knowledge about diseases associated with the malfunction of Na,K-ATPase, this review aims at summarizing the best-characterized transcription regulators that modulate Na,K-ATPase subunit levels. As abnormal expression of Na,K-ATPase subunits have been observed in many carcinoma, we will also discuss transcription factors that are associated with epithelial-to-mesenchymal transition, a crucial step in the progression of many tumors to malignant disease.

Sepsis does not alter red blood cell glucose metabolism or Na+ concentration: A 2H-, 23Na-NMR study

International Nuclear Information System (INIS)

Hotchkiss, R.S.; Song, S.K.; Ling, C.S.; Ackerman, J.J.; Karl, I.E.

1990-01-01

The effects of sepsis on intracellular Na+ concentration ([Na+]i) and glucose metabolism were examined in rat red blood cells (RBCs) by using 23Na- and 2H-nuclear magnetic resonance (NMR) spectroscopy. Sepsis was induced in 15 halothane-anesthetized female Sprague-Dawley rats by using the cecal ligation and perforation technique; 14 control rats underwent cecal manipulation without ligation. The animals were fasted for 36 h, but allowed free access to water. At 36 h postsurgery, RBCs were examined by 23Na-NMR by using dysprosium tripolyphosphate as a chemical shift reagent. Human RBCs from 17 critically ill nonseptic patients and from 7 patients who were diagnosed as septic were also examined for [Na+]i. Five rat RBC specimens had [Na+]i determined by both 23Na-NMR and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). For glucose metabolism studies, RBCs from septic and control rats were suspended in modified Krebs-Henseleit buffer containing [6,6-2H2]glucose and examined by 2H-NMR. No significant differences in [Na+]i or glucose utilization were found in RBCs from control or septic rats. There were no differences in [Na+]i in the two groups of patients. The [Na+]i determined by NMR spectroscopy agreed closely with measurements using ICP-AES and establish that 100% of the [Na+]i of the RBC is visible by NMR. Glucose measurements determined by 2H-NMR correlated closely (correlation coefficient = 0.93) with enzymatic analysis. These studies showed no evidence that sepsis disturbed RBC membrane function or metabolism

SPOLNO NADLEGOVANJE NA DELOVNEM MESTU

OpenAIRE

Rubič, Gašper

2016-01-01

V diplomskem delu smo v uvodu predstavili problem spolnega nadlegovanja na delovnem mestu in predstavili podjetje TEKSTIL d.d. V nadaljevanju smo z anketo raziskali, ali problem spolnega nadlegovanja na delovnem mestu v obravnavanem podjetju obstaja in če, kako se nanj odziva okolje. V teoretičnem delu smo nadaljevali in predstavili definicijo spolnega nadlegovanja, ki je kakršna koli oblika nezaželenega verbalnega in neverbalnega ali fizičnega ravnanja spolne narave z učinkom ali nameno...

Photodesorption of Na atoms from rough Na surfaces

DEFF Research Database (Denmark)

Balzer, Frank; Gerlach, R.; Manson, J.R.

1997-01-01

We investigate the desorption of Na atoms from large Na clusters deposited on dielectric surfaces. High-resolution translational energy distributions of the desorbing atoms are determined by three independent methods, two-photon laser-induced fluorescence, as well as single-photon and resonance......-enhanced two-photon ionization techniques. Upon variation of surface temperature and for different substrates (mica vs lithium fluoride) clear non-Maxwellian time-of-flight distributions are observed with a cos θ angular dependence and most probable kinetic energies below that expected of atoms desorbing from...... atoms are scattered by surface vibrations. Recent experiments providing time constants for the decay of the optical excitations in the clusters support this model. The excellent agreement between experiment and theory indicates the importance of both absorption of the laser photons via direct excitation...

Evaluation of {sup 23}Na(n,2n){sup 22}Na reaction cross-sections

Energy Technology Data Exchange (ETDEWEB)

Manokhin, V N [Institute of Physics and Power Engineering, Obninsk (Russian Federation)

1997-06-01

Using available experimental data and (n,2n) excitation function systematics {sup 23}Na(n,2n){sup 22}Na reaction cross-sections were evaluated for energies ranging from the reaction threshold to 20 MeV. (author). 21 refs, 1 fig., 2 tabs.

Formation of hydroxyl groups and exchange with deuterium on NaHX and NaHY zeolites

International Nuclear Information System (INIS)

Kubelkova, L.; Novakova, J.

1976-01-01

Deammoniation and dehydroxylation of Na(NH 4 )X and Na(NH 4 )Y zeolites were compared. With the X type, both processes overlapped and proceeded more easily than with the Y type. Both H forms contained structural OH groups and hydroxyls denoted as SiOH, to which the 3740 cm -1 band in the IR spectrum was assigned. In addition, the NaHX zeolite contained OH groups characterized by the 3700 and 3600 cm -1 bands. Certain differences in the behaviour of NaHX and NaHY zeolites during deammoniation and dehydroxylation might be attributed to the presence of ''non-localizable'' H atoms. The active sites for the D 2 -OH exchange were probably formed during dehydroxylation. Hydrogen in SiOH groups was replaced by deuterium in both zeolite types more slowly than H atoms in other OH groups, which influenced the kinetic variations in the gaseous phase. The presence of water in the gaseous phase affected the kinetics and could distort the determination of the number of H atoms bound in the zeolites. (author)

High resolution laser spectroscopy of the D lines of on-line produced 21Na, 22Na, 24Na, 25Na using a new high sensitivity method of detection of optical resonances

International Nuclear Information System (INIS)

Huber, G.; Thibault, G.; Klapisch, R.; Duong, H.T.; Vialle, J.L.; Pinard, I.; Juncar, P.; Jacquinot, P.

1975-01-01

A polyisotopic sodium beam of 21 - 25 Na, produced by spallation of Al, was illuminated by a tunable dye laser. The atomic beam, analyzed by a sixpole magnet is then ionized and detected after a mass spectrometer. The results are the isotope shifts, nuclear magnetic moment and quadrupole moment of 25 Na [fr

OGLAŠEVANJE NA SOCIALNEM OMREŽJU FACEBOOK, NA PRIMERU SPLETICNA.SI

OpenAIRE

Reisman, Nina

2011-01-01

Internet je od svojega razvoja dolgo časa obstajal kot prostor za enostransko komunikacijo. Isto se je dogajalo na televiziji, radiu in časopisih, kjer je javnost sprejemala informacije, ki jih je nekdo pripravil. Tradicionalni mediji so hitro doumeli, da takšna vrsta komunikacije ni naravna in ne predstavlja najboljšega ohranjanja gledalcev in poslušalcev. Začela se je uporabljati dvosmerna komunikacija. Trenutno v svetu najbolje poznan primer dvosmerne komunikacije je socialno omrežje F...

FTIR spectra of the solid solutions (Na0.88K0.12)VO3, (Na0.5K0.5)VO3, and Na(V0.66P0.34)O3

Science.gov (United States)

de Waal, D.; Heyns, A. M.

1992-03-01

It is known that three different solid solutions, (Na0.88K0.12)VO3, (Na0.5K0.5)VO3 and Na(V0.66P0.34)O3, form in the (Na,K)(V,P)O3 system. These compounds all have monoclinic crystal structures similar to the pure alkali metal metavanadates containing small cations, e.g. Li+ and Na+ (Space group C2/c). Metavanadates with large cations like K+, Rb+, C+s and NH+4 form orthorhombic crystals, space group Pbcm. All those are structurally related to the silicate pyroxenes. Na(V0.66P0.34)O3 and (Na0.88K0.12)VO3 have the same modified diopside structure as (alpha) - NaVO3 while (Na0.5K0.5)VO3 adopts the true diopside structure. The infrared spectra of the three solid solutions are reported here in comparison with those of (alpha) -NaVO3 and KVO3. The results are also correlated with those obtained in two independent high pressure Raman studies of NH4VO3 and RbVO3 as the introduction of a larger cation like K+ should increase the pressure in the structure.

Medetomidīna un detomidīna hidrogēnhlorīdu struktūra noteikšana

OpenAIRE

Smuļko, Irina

2012-01-01

Medetomidīna un detomidīna hidrogēnhlorīdu struktūras noteikšana. Smuļko I., zinātniskais vadītājs Dr. ķīm., asoc. prof. Actiņš A. Maģistra darbs, 52 lappuses, 37 attēli, 6 tabulas, 29 literatūras avoti. Latviešu valodā. Maģistra darbā pētītas farmaceitiski aktīvās vielas – medetomidīna un detomidīna hidrogēnhlorīdi. Veikti mēģinājumi detomidīna bezūdens formas un monohidrāta struktūras noteikšanai, kā arī medetomidīna bezūdens formu A un B struktūras noteikšanai. Struktūras noteikšanai iz...

NAKUPOVANJE NA SPLETU

OpenAIRE

Visenjak, Monika

2013-01-01

Nakupovanje na spletu je prihodnost poslovanja. Za podjetja pomeni manjše stroške, lažje prilagajanje tržnim pogojem. Hitreje lahko razvijajo odnose in analizirajo uporabnike, saj jim je dan dostop o nakupnih podatkih uporabnika. Za potrošnike je nakupovanje na spletu možnost hitrega, preprostega in učinkovitega nakupovanja od doma ali pisarne. Pomembno je, da se seznanijo z vsemi informacijami in pogoji spletnih trgovin, saj se lahko le tako izognejo nezadovoljstvu ob nakupu v spletni trgovi...

The Na+ transporter, TaHKT1;5-D, limits shoot Na+ accumulation in bread wheat

KAUST Repository

Byrt, Caitlin Siobhan

2014-10-01

Bread wheat (Triticum aestivum L.) has a major salt tolerance locus, Kna1, responsible for the maintenance of a high cytosolic K+/Na+ ratio in the leaves of salt stressed plants. The Kna1 locus encompasses a large DNA fragment, the distal 14% of chromosome 4DL. Limited recombination has been observed at this locus making it difficult to map genetically and identify the causal gene. Here, we decipher the function of TaHKT1;5-D, a candidate gene underlying the Kna1 locus. Transport studies using the heterologous expression systems Saccharomyces cerevisiae and Xenopus laevis oocytes indicated that TaHKT1;5-D is a Na+-selective transporter. Transient expression in Arabidopsis thaliana mesophyll protoplasts and in situ polymerase chain reaction indicated that TaHKT1;5-D is localised on the plasma membrane in the wheat root stele. RNA interference-induced silencing decreased the expression of TaHKT1;5-D in transgenic bread wheat lines which led to an increase in the Na+ concentration in the leaves. This indicates that TaHKT1;5-D retrieves Na+ from the xylem vessels in the root and has an important role in restricting the transport of Na+ from the root to the leaves in bread wheat. Thus, TaHKT1;5-D confers the essential salinity tolerance mechanism in bread wheat associated with the Kna1 locus via shoot Na+ exclusion and is critical in maintaining a high K+/Na+ ratio in the leaves. These findings show there is potential to increase the salinity tolerance of bread wheat by manipulation of HKT1;5 genes.

The Na+ transporter, TaHKT1;5-D, limits shoot Na+ accumulation in bread wheat

KAUST Repository

Byrt, Caitlin Siobhan; Xu, Bo; Krishnan, Mahima; Lightfoot, Damien; Athman, Asmini; Jacobs, Andrew Keith; Watson-Haigh, Nathan S.; Plett, Darren; Munns, Rana; Tester, Mark A.; Gilliham, Matthew

2014-01-01

Bread wheat (Triticum aestivum L.) has a major salt tolerance locus, Kna1, responsible for the maintenance of a high cytosolic K+/Na+ ratio in the leaves of salt stressed plants. The Kna1 locus encompasses a large DNA fragment, the distal 14% of chromosome 4DL. Limited recombination has been observed at this locus making it difficult to map genetically and identify the causal gene. Here, we decipher the function of TaHKT1;5-D, a candidate gene underlying the Kna1 locus. Transport studies using the heterologous expression systems Saccharomyces cerevisiae and Xenopus laevis oocytes indicated that TaHKT1;5-D is a Na+-selective transporter. Transient expression in Arabidopsis thaliana mesophyll protoplasts and in situ polymerase chain reaction indicated that TaHKT1;5-D is localised on the plasma membrane in the wheat root stele. RNA interference-induced silencing decreased the expression of TaHKT1;5-D in transgenic bread wheat lines which led to an increase in the Na+ concentration in the leaves. This indicates that TaHKT1;5-D retrieves Na+ from the xylem vessels in the root and has an important role in restricting the transport of Na+ from the root to the leaves in bread wheat. Thus, TaHKT1;5-D confers the essential salinity tolerance mechanism in bread wheat associated with the Kna1 locus via shoot Na+ exclusion and is critical in maintaining a high K+/Na+ ratio in the leaves. These findings show there is potential to increase the salinity tolerance of bread wheat by manipulation of HKT1;5 genes.

Osmotic and ionic effects of NaCl and Na₂SO₄ salinity on Phragmites australis

DEFF Research Database (Denmark)

Pagter, Majken; Bragato, Claudia; Malagoli, Mario

2009-01-01

Osmotic and ion-specific effects of NaCl and Na2SO4 on Phragmites australis (Cav.) Trin ex. Steud. were investigated in a laboratory experiment by examining effects of iso-osmotic solutions of NaCl and Na2SO4 on growth, osmolality of cell sap, proline content, elemental composition and gas exchange....... Plants were supplied with a control standard nutrient solution (Ψ = -0.09 MPa) or solutions of NaCl or Na2SO4 at water potentials of -0.50, -1.09 or -1.74 MPa. Salt treatments increased root concentrations of Na and S or Cl, whereas P. australis had efficient mechanisms for exclusion of Na and S...... and partly Cl ions from the leaves. Incomplete exclusion of Cl from the leaves may affect aboveground biomass production, which was significantly more reduced by NaCl than Na2SO4. Stomatal conductance was negatively influenced by decreasing water potentials caused by NaCl or Na2SO4, implying that a non...

Polarization and collision velocity dependence of associative ionization in cold Na (3p)-Na(3p) collisions

NARCIS (Netherlands)

Meijer, H.A.J.

1990-01-01

We studied the polarization dependence of the associative ionization (AI) process Na(3p) + Na(3p) → Na2+ at collision velocities between 100 and 700 m/s (5 and 200 K), using linearly and circularly polarized light for the excitation. We found that the polarization dependence varies strongly in the

Analise da expressão de chaperonas moleculares em plantas e clonagem, purificação e caracterização inicial das proteinas Hsp100 e Hsp90 de cana-de-açucar

OpenAIRE

Thiago Carlos Cagliari

2009-01-01

Resumo: As proteinas sao macromoleculas que possuem importancia vital para o funcionamento celular, participando da maioria das reacoes biologicas e tambem como componentes estruturais. Para que uma proteina possa exercer sua funcao, precisa atingir sua estrutura nativa atraves de um processo denominado enovelamento proteico. Neste contexto, as chaperonas moleculares sao proteinas capazes de auxiliar no enovelamento de outras proteinas, atuando na prevencao de agregados, desagregacao, translo...

Erythrocyte Na+/K+ ATPase activity measured with sup 23 Na NMR

Energy Technology Data Exchange (ETDEWEB)

Ouwerkerk, R.; van Echteld, C.J.; Staal, G.E.; Rijksen, G. (University Hospital, Utrecht (Netherland))

1989-11-01

A {sup 23}Na NMR assay for measurement of erythrocyte Na+/K+ ATPase activity is presented. Using the nonpermeant shift reagent dysprosium tripolyphosphate the signals of intra- and extracellular sodium are separated, enabling measurement of sodium fluxes nondestructively, without the need to physically separate the cells from their environment. By increasing membrane permeability with nystatin we have shown that the assay allows the detection of differences in membrane permeability. With low doses of nystatin the ouabain-sensitive sodium flux increased more than twofold. With high doses of nystatin the Na+/K+ pump could not prevent an almost total equilibration of intra- and extracellular sodium. All sodium that entered the cells remained NMR visible, proving that sodium influx can be measured quantitatively. {sup 31}P NMR spectra taken before and after the assay revealed a slight acidification of the cells and no significant change in ATP concentration. No evidence of Dy3+ entering the cell was observed.

Molecular dynamics investigation of Na+ in Na2Ni2TeO6

International Nuclear Information System (INIS)

Sau, Kartik; Kumar, P. Padma

2014-01-01

An inter-atomic potential for Na 2 Ni 2 TeO 6 in the Parrinello- Rahman-Vashishta (PRV) model is parameterized empirically. The potential reproduces variety of structural and transport properties of that material in good agreement with recent experimental results. The study provides fresh insights on the migration channels and mechanism of Na + in the system

Efeito do plasma de oxigênio na dentina previamente exposta ao NaOCl

Directory of Open Access Journals (Sweden)

Maíra do PRADO

Full Text Available Resumo Introdução O tratamento de plasma é uma tecnologia eficaz que pode manter as propriedades internas dos materiais inalteradas após o tratamento, modificando apenas a superfície. Objetivo Avaliar o efeito do plasma de oxigênio na dentina previamente exposta ao NaOCl 6%. Material e método Foram utilizados 60 incisivos bovinos. A coroa foi removida, a raiz foi dividida e as faces planificadas, totalizando 120 segmentos referentes ao terço cervical. As amostras foram divididas em dois grupos: controle (imersa em NaOCl 6%, lavada com água destilada, seca, imersa em EDTA 17%, lavada e seca e plasma de oxigênio (após tratamento descrito no grupo controle, plasma de oxigênio foi aplicado por 30 s. As amostras foram avaliadas qualitativamente em relação à topografia por microscopia eletrônica de varredura, utilizando-se microfotografias com ampliação de 1.000×. O goniômetro Ramé-hart foi utilizado para a mensuração do ângulo de contato entre as superfícies e as seguintes soluções foram utilizadas: água, etilenoglicol e di-iodometano. Em seguida, a energia de superfície, representada pelas componentes polar e dispersiva, foi calculada. Avaliou-se também o escoamento dos cimentos Pulp Canal Sealer EWT (PCS e Real Sal SE (RS na superfície dentinária. Os dados foram analisados estatisticamente utilizando os testes Kruskal-Wallis e Mann-Whitney U (p<0,05. Resultado O tratamento com plasma levou à formação de uma camada semelhante à smear layer na superfície dentinária. Este tratamento levou a um aumento da energia de superfície e da componente polar, favorecendo a hidrofilicidade da superfície. Entretanto, desfavoreceu o escoamento do cimento PCS e não influenciou no escoamento do cimento RS. Conclusão O plasma de oxigênio ocasionou mudanças topográficas na superfície dentinária, favorecendo a hidrofilicidade desta. Contudo, não favoreceu o escoamento dos cimentos endodônticos na dentina.

Phase formation in the systems ZrO2-H2SO4-Na2SO4 (NaCl)-H2O

International Nuclear Information System (INIS)

Sozinova, Yu.P.; Motov, D.L.; Rys'kina, M.P.

1988-01-01

Formation of solid phases in the systems ZrO 2 - H 2 SO 4 - Na 2 SO 4 (NaCl) - H 2 O at 25 and 75 deg C is studied. Three basic Na 2 Zr(OH) 2 (SO 4 ) 2 x (0.2 - 0.4)H 2 O, NaZrOH(SO 4 ) 2 x H 2 O, NaZrO 0.5 (OH) 2 SO 4 x 2H 2 O and three normal sodium sulfatozirconates Na 2 Zr(SO 4 ) 3 x 3H 2 O, Na 4 Zr(SO 4 ) 4 x 3H 2 O, Na 6 Zr(SO 4 ) 5 x 4H 2 O have been isolated, their solubility and crystal optical properties are determined

Modification of NaK (Na and K) dissolution device at the L.E.C.I

International Nuclear Information System (INIS)

Mansard, Bernard; Ducas, Serge; Riviere, Michel

1969-12-01

As three NaK dissolution devices had been operated since 1965 and as irradiation assemblies with a greater capacity (2 to 3 times) are now to be used, the modification of these dissolution devices is addressed. This requires a better control of the dissolution reaction (the NaK + alcohol reaction is highly exothermic and results in an effervescence which requires a greater volume). The objectives are therefore to delay the dissolution, to trigger it, to stop it, to control it at will, and to release heat. The new device is then described with its vessel, its cap, its ball valve, and its two tight sleeves. The operation principle is described, as well as the NaK draining process, and the NaK dissolution. Safety, time saving and raw matter saving issues are finally outlined

OGLAŠEVANJE NA FACEBOOKU V SLOVENIJI

OpenAIRE

Dobnik, Monja

2013-01-01

Danes so zahvaljujoč napredni mobilni tehnologiji družbena omrežja z nami na vsakem koraku. Facebook (FB) se po priljubljenosti uvršča v sam vrh družbenih omrežij in glede na to, da ga uporablja že več kot milijarda zemljanov, ponuja tudi odlične trg za oglaševanje. To so ugotovili tudi slovenski podjetniki. V diplomski nalogi je predstavljeno, kako na FB oglašujejo nekatera slovenska podjetja, s pomočjo spletnega vprašalnika pa je ugotovljeno tudi, kaj o oglasih na FB menijo njegovi uporabni...

Myocardial Na,K-ATPase: Clinical aspects

Science.gov (United States)

Kjeldsen, Keld

2003-01-01

The specific binding of digitalis glycosides to Na,K-ATPase is used as a tool for Na,K-ATPase quantification with high accuracy and precision. In myocardial biopsies from patients with heart failure, total Na,K-ATPase concentration is decreased by around 40%; a correlation exists between a decrease in heart function and a decrease in Na,K-ATPase concentration. During digitalization, around 30% of remaining pumps are occupied by digoxin. Myocardial Na,K-ATPase is also influenced by other drugs used for the treatment of heart failure. Thus, potassium loss during diuretic therapy has been found to reduce myocardial Na,K-ATPase, whereas angiotensin-converting enzyme inhibitors may stimulate Na,K pump activity. Furthermore, hyperaldosteronism induced by heart failure has been found to decrease Na,K-ATPase activity. Accordingly, treatment with the aldosterone antagonist, spironolactone, may also influence Na,K-ATPase activity. The importance of Na,K pump modulation with heart disease, inhibition in digitalization and other effects of medication should be considered in the context of sodium, potassium and calcium regulation. It is recommended that digoxin be administered to heart failure patients who, after institution of mortality-reducing therapy, still have heart failure symptoms, and that the therapy be continued if symptoms are revealed or reduced. Digitalis glycosides are the only safe inotropic drugs for oral use that improve hemodynamics in heart failure. An important aspect of myocardial Na,K pump affection in heart disease is its influence on extracellular potassium (Ke) homeostasis. Two important aspects should be considered: potassium handling among myocytes, and effects of potassium entering the extracellular space of the heart via the bloodstream. It should be noted that both of these aspects of Ke homeostasis are affected by regulatory aspects, eg, regulation of the Na,K pump by physiological and pathophysiological conditions, as well as by medical

Advancement of technology towards developing Na-ion batteries

Science.gov (United States)

Jamesh, Mohammed Ibrahim; Prakash, A. S.

2018-02-01

The Na-ion-batteries are considered much attention for the next-generation power-sources due to the high abundance of Na resources that lower the cost and become the alternative for the state of the art Li-ion batteries in future. In this review, the recently reported potential cathode and anode candidates for Na-ion-batteries are identified in-light-of-their high-performance for the development of Na-ion-full-cells. Further, the recent-progress on the Na-ion full-cells including the strategies used to improve the high cycling-performance (stable even up-to 50000 cycles), operating voltage (even ≥ 3.7 V), capacity (>350 mAhg-1 even at 1000 mAg-1 (based-on-mass-of-the-anode)), and energy density (even up-to 400 Whkg-1) are reviewed. In addition, Na-ion-batteries with the electrodes containing reduced graphene oxide, and the recent developments on symmetric Na-ion-batteries are discussed. Further, this paper identifies the promising Na-ion-batteries including the strategies used to assemble full-cell using hard-carbon-anodes, Na3V2(PO4)3 cathodes, and other-electrode-materials. Then, comparison between aqueous and non-aqueous Na-ion-batteries in terms of voltage and energy density has been given. Later, various types of electrolytes used for Na-ion-batteries including aqueous, non-aqueous, ionic-liquids and solid-state electrolytes are discussed. Finally, commercial and technological-developments on Na-ion-batteries are provided. The scientific and engineering knowledge gained on Na-ion-batteries afford conceivable development for practical application in near future.

Negative electrodes for Na-ion batteries.

Science.gov (United States)

Dahbi, Mouad; Yabuuchi, Naoaki; Kubota, Kei; Tokiwa, Kazuyasu; Komaba, Shinichi

2014-08-07

Research interest in Na-ion batteries has increased rapidly because of the environmental friendliness of sodium compared to lithium. Throughout this Perspective paper, we report and review recent scientific advances in the field of negative electrode materials used for Na-ion batteries. This paper sheds light on negative electrode materials for Na-ion batteries: carbonaceous materials, oxides/phosphates (as sodium insertion materials), sodium alloy/compounds and so on. These electrode materials have different reaction mechanisms for electrochemical sodiation/desodiation processes. Moreover, not only sodiation-active materials but also binders, current collectors, electrolytes and electrode/electrolyte interphase and its stabilization are essential for long cycle life Na-ion batteries. This paper also addresses the prospect of Na-ion batteries as low-cost and long-life batteries with relatively high-energy density as their potential competitive edge over the commercialized Li-ion batteries.

Corpo e sexualidade na gravidez

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Natalúcia Matos Araújo

2012-06-01

Full Text Available Estudo etnográfico que teve como objetivo compreender como as gestantes vivenciam os processos fisiológicos do seu corpo durante a gestação e a sua repercussão na sexualidade. A pesquisa envolveu sete mulheres residentes em bairro popular de São Paulo. Na coleta de dados, utilizou-se observação participante e entrevista com questões norteadoras. Os dados foram apresentados na forma de narrativa e posteriormente organizados nas categorias: Percebendo as transformações corporais; Convivendo com as mudanças no corpo; Sentimentos e sensações na vida sexual durante a gestação e imaginando o corpo e a sexualidade após a gestação. As mulheres referiram-se às transformações do corpo como desconfortos e expressaram a preocupação de que fossem definitivas. Expressaram o desejo de que, após o parto, o corpo volte a ser como era e que volte a sentir desejo sexual. O reconhecimento destes fatos constitui-se numa ferramenta primordial na adequação das práticas profissionais.

Comparison of the effectiveness of seven amiloride congeners as inhibitors of Na/H and Na/Ca antiport in cultured smooth muscle cells

International Nuclear Information System (INIS)

Smith, L.; Higgins, B.L.; Cragoe, E.J. Jr.; Smith, J.B.

1987-01-01

The authors cultured smooth muscle cells from rat aorta and assayed Na/Ca antiport by measuring the initial rate of 45 Ca influx in Na-loaded cells. Na/H antiport was assayed by measuring the initial rate of 22 Na influx in acid-loaded cells. The external medium was the same for both assays except Na was 10 mM for Na/H antiport and O for the Na/Ca antiport assay. The dose of each congener that caused 50% inhibition (I 50 ) was calculated using a log-log median effect plot. The linear regression coefficients ranged from 0.916 to 0.998. Of all the compounds tested only dimethylbenzamil is more potent as an inhibitor of Na/Ca compared to Na/H antiport

Presoja notranjih kontrol pri obračunu davka na dodano vrednost na primeru "Podjetja x"

OpenAIRE

Majcen, Borut

2016-01-01

Poslovanje podjetja si je ob odsotnosti notranjih kontrol nemogoče predstavljati. Podjetja so podvržena raznim tveganjem, še posebej v današnjih razmerah globalnega poslovanja, ko se podjetja soočajo z vedno novimi izzivi, kar prinaša tudi nova tveganja. Najučinkovitejši ukrep za obvladovanje tveganj predstavlja vzpostavitev sistema notranjih kontrol. Obvladovanje tveganj pa ne poteka samo na ravni podjetja kot celote, ampak je prisotno na vseh področjih delovanja podjetja, torej tudi na p...

Atomic layer deposition of metal oxide by non-aqueous sol-gel chemistry =

Science.gov (United States)

Marichy, Catherine

O trabalho apresentado neste manuscrito foi desenvolvido no ambito do programa doutoral intitulado “Deposicao de Camadas Atomicas (ALD) de oxido de metais por sol-gel nao-aquoso”. O objectivo deste trabalho foi a preparacao de hetero-estruturas funcionais por ALD e a sua caracterizacao. Foi desenvolvido um novo processo de deposicao de oxido de estanho a temperatura baixa-moderada, utilizando um metodo ALD nao-aquoso, o qual foi aplicado com sucesso ao revestimento controlado das paredes internas e externas de nanotubos de carbono. Uma vez que a preparacao de nanomateriais funcionais requer uma elevada exatidao do processo de deposicao, foi demonstrada a deposicao precisa de filmes que se adaptem a forma do substrato ou de filmes nano-estruturados constituidos por particulas em varios substratos. Alem disso, foram depositados com grande exatidao varios oxidos de metal em nanotubos de carbono e demonstrou-se a possibilidade de ajustar o revestimento feito por ALD atraves do controlo da funcionalizacao da superficie do substrato nano-estruturado de carbono. As hetero-estruturas obtidas foram posteriormente aplicadas como sensores de gases. O melhoramento verificado na sensibilidade foi atribuido a formacao de heterojuncoes p-n entre o filme de oxido de metais e o suporte. O trabalho desenvolvido tendo como objetivo o controlo do revestimento por ALD atraves da funcionalizacao da superficie do suporte e certamente de interesse para o design de hetero-estruturas funcionais baseadas em substratos de carbono. De facto, durante o ultimo periodo do programa de doutoramento, este conceito foi alargado a funcionalizacao e revestimento com oxidos de metal de fibras de carbono preparadas por “electrospinning”, de forma a melhorar a estabilidade e a atividade eletrocatalitica de catalisadores a base de Pt. Este trabalho foi realizado maioritariamente na Universidade de Aveiro mas tambem na Universidade Nacional de Seul e beneficiou de varias colaboracoes internacionais

Culturas morais e políticas de desenvolvimento na noruega e na união europeia

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Maria Macedo Barroso

2014-06-01

Full Text Available A partir de um diálogo entre os casos da Noruega e da União Europeia, pretendemos analisar a combinação de diferentes fatores e escalas de processos sociais (individuais, institucionais e de unidades políticas nacionais e supranacionais, estruturantes na formação dos sentidos sociais do desenvolvimento, notadamente das relações entre princípios morais e trocas interessadas, constitutivas das "culturas morais" dos universos analisados. Na perspectiva dos indivíduos, observaremos pela lente do caso da UE as motivações, vocações e histórias de vida dos "profissionais do desenvolvimento", bem como as razões da adesão da opinião pública às ações de cooperação internacional. Na escala institucional, abordaremos, nos dois casos, os modelos político-administrativos utilizados pela burocracia do desenvolvimento, e as lógicas dos diferentes grupos organizados para disputar seus recursos, no caso da Noruega. Na dimensão dos Estados, analisaremos a lógica das políticas nacionais e internacionais sob as quais são negociadas as intervenções de cooperação bilateral e/ou multilaterais tanto na Noruega quanto na UE.

FUNCIONES E IMPORTANCIA ECONÓMICA DEL RECURSO CHAPULIXTLE (DODONAEA VISCOSA EN UN EJIDO DEL SUBTRÓPICO MEXICANO

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José Isabel Juan Pérez

2013-06-01

Full Text Available El chapulixtle (Dodonaea viscosa es una planta cosmopolita. Para demostrar la importancia económica de esta planta, se realizó una investigación de campo en un Ejido del Subtrópico Mexicano, durante el período 2010 - 2012. Fue explorado el hábitat de la planta y su utilización por parte de las familias campesinas. La investigación se sustentó en la Geografía Ambiental (Bocco, 2007 y la Ecología Cultural (Steward, 1955, complementándose con la aplicación de un cuestionario al 100% de las familias campesinas, observación directa, observación participante, estadística descriptiva y uso del equipo DGPS. Los resultados demuestran que el uso del chapulixtle en el Ejido se relaciona con las condiciones socioculturales y económicas de los habitantes y por las diferentes estrategias utilizadas para su manejo. Los usos principales son: ecológico, ambiental, agrícola, pecuario, artesanal, medicinal, para combustible, ornamental, construcción de viviendas, agroforestal y recarga de acuíferos. En las zonas rurales, esta planta ha contribuido significativamente en la economía de las familias campesinas, además, las condiciones socioculturales de las familias campesinas del Subtrópico Mexicano han influido en la diversidad de usos. En el Ejido se encontraron 22 usos diferentes, y lo más probable es que en otras comunidades del territorio mexicano existan otros más.

Intermittent Hypoxia Inhibits Na+-H+ Exchange-Mediated Acid Extrusion Via Intracellular Na+ Accumulation in Cardiomyocytes

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Huai-Ren Chang

2018-04-01

Full Text Available Background/Aims: Intermittent hypoxia (IH has been shown to exert preconditioning-like cardioprotective effects. It also has been reported that IH preserves intracellular pH (pHi during ischemia and protects cardiomyocytes against ischemic reperfusion injury. However, the exact mechanism is still unclear. Methods: In this study, we used proton indicator BCECF-AM to analyze the rate of pHi recovery from acidosis in the IH model of rat neonatal cardiomyocytes. Neonatal cardiomyocytes were first treated with repetitive hypoxia-normoxia cycles for 1-4 days. Cells were then acid loaded with NH4Cl, and the rate of pHi recovery from acidosis was measured. Results: We found that the pHi recovery rate from acidosis was much slower in the IH group than in the room air (RA group. When we treated cardiomyocytes with Na+-H+ exchange (NHE inhibitors (Amiloride and HOE642 or Na+-free Tyrode solution during the recovery, there was no difference between RA and IH groups. We also found intracellular Na+ concentration ([Na+]i significantly increased after IH exposure for 4 days. However, the phenomenon could be abolished by pretreatment with ROS inhibitors (SOD and phenanathroline, intracellular calcium chelator or Na+-Ca2+ exchange (NCX inhibitor. Furthermore, the pHi recovery rate from acidosis became faster in the IH group than in the RA group when inhibition of NCX activity. Conclusions: These results suggest that IH would induce the elevation of ROS production. ROS then activates Ca2+-efflux mode of NCX and results in intracellular Na+ accumulation. The rise of [Na+]i further inhibits the activity of NHE-mediated acid extrusion and retards the rate of pHi recovery from acidosis during IH.

Elastic Coulomb breakup of 34Na

Science.gov (United States)

Singh, G.; Shubhchintak, Chatterjee, R.

2016-08-01

Background: 34Na is conjectured to play an important role in the production of seed nuclei in the alternate r -process paths involving light neutron rich nuclei very near the β -stability line, and as such, it is important to know its ground state properties and structure to calculate rates of the reactions it might be involved in, in the stellar plasma. Found in the region of `island of inversion', its ground state might not be in agreement with normal shell model predictions. Purpose: The aim of this paper is to study the elastic Coulomb breakup of 34Na on 208Pb to give us a core of 33Na with a neutron and in the process we try and investigate the one neutron separation energy and the ground state configuration of 34Na. Method: A fully quantum mechanical Coulomb breakup theory within the architecture of post-form finite range distorted wave Born approximation extended to include the effects of deformation is used to research the elastic Coulomb breakup of 34Na on 208Pb at 100 MeV/u. The triple differential cross section calculated for the breakup is integrated over the desired components to find the total cross-section, momentum, and angular distributions as well as the average momenta, along with the energy-angular distributions. Results: The total one neutron removal cross section is calculated to test the possible ground state configurations of 34Na. The average momentum results along with energy-angular calculations indicate 34Na to have a halo structure. The parallel momentum distributions with narrow full widths at half-maxima signify the same. Conclusion: We have attempted to analyze the possible ground state configurations of 34Na and in congruity with the patterns in the `island of inversion' conclude that even without deformation, 34Na should be a neutron halo with a predominant contribution to its ground state most probably coming from 33Na(3 /2+)⊗ 2 p3 /2ν configuration. We also surmise that it would certainly be useful and rewarding to test our

Osmotic and activity coefficients of aqueous NaTcO4 and NaReO4 solutions at 250C

International Nuclear Information System (INIS)

Boyd, G.E.

1978-01-01

Isopiestic vapor-pressure comparison experiments were performed with aqueous binary sodium perchlorate, pertechnetate, and perrhenate solutions to concentrations of approximately 8.5 m. Osmotic coefficients for these solutions and mean molal ionic activity coefficients for NaTcO 4 and NaReO 4 were derived from the isotonic molalities. Pitzer's treatment was applied to describe the concentration dependence of the osmotic coefficients of NaClO 4 , NaTcO 4 , and NaReO 4 , and the implications of the parameters derived from a least-squares fit are discussed in terms of solvent structure and interionic forces. 4 tables, 1 figure

Galeguismo, agro e agrarismo na Galicia da II República

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Cabo Villaverde, Miguel

2009-12-01

Full Text Available The Partido Galeguista (PG was created in December 1931 as the expression of Galician nationalism during the Second Republic (1931-1936. Prior to that, the Galician nationalists had been very influential in the cultural sphere but rather powerless from a political point of view. The PG regarded agriculture and peasantry as a priority, not only because of their objective importance in the Galician economy and society in the 1930s but also because they were seen as the bulwarks of the national identity. In fact, the characteristics, needs and paths of development of the Galician agrarian sector were usually defined as opposed to those of the rest of Spain. It is then understable that the PG tried to win the agrarian unions over, and that it is arguable that it had plenty of common features with the so-called Agrarian Parties in other European regions.

O Partido Galeguista (PG foi creado en decembro de 1931 como expresión do nacionalismo galego durante a Segunda República (1931-1936. Con anterioridade, os nacionalistas galegos foron moi influíntes no eido cultural pero maiormente inoperantes dende o punto de vista político. O PG consideraba a agricultura e o campesiñado como unha prioridade, non só pola súa importancia obxectiva na economía e sociedade galegas dos anos trinta senón tamén porque eran vistos como os baluartes da identidade nacional. De feito, as características, necesidades e vías de desenvolvemento do sector agrario galego eran normalmente definidas en oposición ás do resto de España. É daquela comprensible que o PG tentase gañarse ás sociedades agrarias, e mesmo se pode afirmar que tiña moitos puntos en común cos chamados Partidos Agrarios doutras rexións europeas.

Energy levels of the single excited states in NaI and Na-like ions

International Nuclear Information System (INIS)

El-Sherbini, T.M.; Wahby, A.S.

1987-08-01

Energy levels of the single excited 1s 2 2s 2 2p 6 ns( 2 S), 1s 2 2s 2 2p 6 mp( 2 P), 1s 2 2s 2 2p 6 md( 2 D) and 1s 2 2s 2 2p 6 nf( 2 F); n=4-7, m=3-6 states for NaI and Na-like ions are calculated using the one configuration Hartree-Fock method. Good agreement is obtained between our results for the higher members of the NaI sequence and previous data from photo-absorption and beam foil experiments. (author). 11 refs, 3 figs, 9 tabs

Fabrication of implanted $^{22}$Na targets

CERN Multimedia

2002-01-01

A knowledge of the $^{22}$Na(p,$\\gamma$)$^{23}$ Mg reaction rate is of significant astrophysical interest. In order to complete previous studies of this reaction, radioactive $^{22}$Na targets of high purity are required. We ask for support to fabricate these targets via the implantation technique at ISOLDE GPS (off—line mode) using $^{22}$Na nuclides in an Al matrix produced in Nov. 1990 at the PSI (Zürich). The $^{22}$Na nuclides are released and ionized in a surface ionisation source, mass-analyzed at ISOLDE GPS, and implanted in a Ni-Ta backing and a C—foil in a special implantation setup.

Painful Na-channelopathies: an expanding universe.

Science.gov (United States)

Waxman, Stephen G

2013-07-01

The universe of painful Na-channelopathies--human disorders caused by mutations in voltage-gated sodium channels--has recently expanded in three dimensions. We now know that mutations of sodium channels cause not only rare genetic 'model disorders' such as inherited erythromelalgia and channelopathy-associated insensitivity to pain but also common painful neuropathies. We have learned that mutations of NaV1.8, as well as mutations of NaV1.7, can cause painful Na-channelopathies. Moreover, recent studies combining atomic level structural models and pharmacogenomics suggest that the goal of genomically guided pain therapy may not be unrealistic. Copyright © 2013 Elsevier Ltd. All rights reserved.

Usmerjanje urbanega razvoja na mestni ravni

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Mojca Šašek Divjak

1999-01-01

Full Text Available Kot je poudarjeno v predstavljenem načrtu Kopenhagna, mestni načrt ne more rešiti vseh planskih problemov mesta. Predstavljal naj bi predvideni red, ki pa se pogosto sproti podira glede na nepredvidena dogajanja v prostoru. Probleme je velikokrat treba reševati šele, ko se pokažejo. Zato mora biti mestni načrt zastavljen dovolj prilagodljivo in fleksibilno, da dovoljuje potrebne spremembe. Vendar mora kljub temu dati mestu trdne glavne usmeritve in s tem omogočiti, da meščani lahko izkoristijo priložnosti, ki jih nudi nova doba in uveljavljajo nove kvalitete bivanja.

Velocity distribution and dimer formation in a Na/Na2 beam

International Nuclear Information System (INIS)

Bergmann, K.; Hefter, U.; Hering, P.

1977-01-01

Using the TOF via optical pumping method and the Doppler-shifted laser induced emission described previously, the authors have measured the parallel and perpendicular velocity distribution respectively for Na atoms and Na 2 molecules in a variety of individual quantum states. In addition they monitored the flux of molecules in specific states while changing the stagnation pressure. In all cases a significant dependence on the internal energy of the molecules was found. The goal of these experiments is to improve understanding of the beam dynamics and the dimer formation process. (Auth.)

Angular distributions of photoelectrons from free Na clusters

International Nuclear Information System (INIS)

Wopperer, P.; Dinh, P. M.; Faber, B.; Reinhard, P.-G.; Suraud, E.

2010-01-01

We explore, from a theoretical perspective, photoelectron angular distributions (PADs) of the Na clusters Na 8 , Na 10 , Na 12 , Na 18 , Na 3 + , Na 11 + , Na 13 + , and Na 19 + . The basis of the description is the time-dependent local-density approximation (TDLDA), augmented by a self-interaction correction (SIC) to describe ionization properties correctly. The scheme is solved on a numerical grid in coordinate space with absorbing bounds. We assume for each cluster system an isotropic ensemble of free clusters and develop for the case of one-photon emission analytical formulas for computing the orientation-averaged PAD on the basis of a few TDLDA-SIC calculations for properly chosen reference orientations. It turns out that all the information in the averaged PAD is contained in one anisotropy parameter. We find that this parameter varies very little with system size, but as a whole is crucially influenced by the detailed ionic structure. We also make comparisons with direct orientation averaging and consider one example reaching outside the perturbative regime.

The Na+ transport in gram-positive bacteria defect in the Mrp antiporter complex measured with 23Na nuclear magnetic resonance.

Science.gov (United States)

Górecki, Kamil; Hägerhäll, Cecilia; Drakenberg, Torbjörn

2014-01-15

(23)Na nuclear magnetic resonance (NMR) has previously been used to monitor Na(+) translocation across membranes in gram-negative bacteria and in various other organelles and liposomes using a membrane-impermeable shift reagent to resolve the signals resulting from internal and external Na(+). In this work, the (23)Na NMR method was adapted for measurements of internal Na(+) concentration in the gram-positive bacterium Bacillus subtilis, with the aim of assessing the Na(+) translocation activity of the Mrp (multiple resistance and pH) antiporter complex, a member of the cation proton antiporter-3 (CPA-3) family. The sodium-sensitive growth phenotype observed in a B. subtilis strain with the gene encoding MrpA deleted could indeed be correlated to the inability of this strain to maintain a lower internal Na(+) concentration than an external one. Copyright © 2013 Elsevier Inc. All rights reserved.

Quatenary Na//F, Cl, CO3, MoO4 system

International Nuclear Information System (INIS)

Kochkarov, Zh.A.; Lok''yaeva, S.M.; Shurdumov, G.K.; Gasanaliev, A.M.; Trunin, A.S.

1999-01-01

Perspective in applied respect quatenary system (NaF) 2 -(NaCl)-Na 2 CO 3 -Na 2 MoO 4 being element of narrowing of more complex six-membered mutual Na//F, Cl, CO 3 , MoO 4 (WO 4 ) system is investigated by differential thermal analysis with the use of projection-thermographic method for the first time. Crystallization tree of Na//F, Cl, CO 3 , MoO 4 system is established. It is shown that this system by tetrahedrating (NaF) 2 -Na 2 CO 3 -Na 3 ClMoO 4 section is triangulated on two stable system: (NaF) 2 -Na 3 ClMoO 4 -Na 2 CO 3 -(NaCl) 2 and (NaF) 2 -Na 3 ClMoO 4 -Na 2 CO 3 -Na 2 MoO 4 . Phase single units are determined too. Coordinates of desired quatenary nonvariant points are calculated on analytical models of surfaces by mutual crystallization of two phases and are refined by differential thermal analysis [ru

Experimental Study of Na based Titanium Nanofluid-Water Reaction

Energy Technology Data Exchange (ETDEWEB)

Park, Gunyeop; Kim, Soo Jae; Baek, Jehyun; Kim, Hyun Soo; Oh, Sun Ryung; Park, Hyun Sun; Kim, Moo Hwan [POSTECH, Pohang (Korea, Republic of)

2015-10-15

In KALIMER-600, a sodium-cooled fast reactor designed by KAERI, thermal energy is transported from high-temperature liquid Na (526 .deg. C at 0.1 MPa) to low temperature water (230 .deg. C at - 19.5 MPa) through a heat exchanger. If any leakage or rupture occurs during the operation of this heat exchanger, highly pressurized liquid water can penetrate into the liquid Na channels; this contact should instantly cause SWR. As reaction continues, liquid water is soon vaporized by pressure drop and huge amount of reaction heat. This generated water vapor expands large reaction area and increases sodium-water vapor reaction process. Therefore, the rapid generation of reaction product (like H{sub 2}) and water vapor increases the system pressure that can cause the system failure in SFR. To reduce this strong chemical reaction phenomena between Na and water, some we have focused on suppressing the chemical reactivity of liquid Na by dispersing nanoparticles (NPs). For the real application of NaTiNF, the pressure change induced by NaTiNF-water reaction is compared with Na-water reaction in the present study. NaTiNF contains 100nm of Ti NPs at 0.2 vol. %. The reaction rate of NaTiNF-water reaction is also investigated as reaction temperature increases. Sodium-water vapor reaction (SVR) will occur when an SWR accident occurs in SFR. In this manner, NaTiNF-water vapor reaction is experimentally performed for ensuring the suppression of chemical reactivity of NaTiNF in contact with water vapor. In the basic step for reducing risk of an SWR in SFR, we have experimentally verified the suppressed chemical reactivity of liquid sodium using Ti NPs through SWR and SVR experiments. In SWR, Na based titanium nanofluid (NaTiNF) shows lower pressure change than Na. As T{sub R} increases, P{sub max} in Na-water reaction increases while NaTiNF does not. The reaction rate of NaTiNF shows twice slower than that of Na. In SVR, NaTiNF shows slower temperature increase than Na. The distinct

Phase equilibria in the NaF-CdO-NaPO{sub 3} system at 873 K and crystal structure and physico-chemical characterizations of the new Na{sub 2}CdPO{sub 4}F fluorophosphate

Energy Technology Data Exchange (ETDEWEB)

Aboussatar, Mohamed [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Laboratoire de Physico-Chimie de l’État Solide, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax (Tunisia); Mbarek, Aïcha [Laboratoire de Chimie Industrielle, Ecole Nationale d’Ingénieurs de Sfax, Université de Sfax, BP W3038, 3000 Sfax (Tunisia); Naili, Houcine [Laboratoire de Physico-Chimie de l’État Solide, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax (Tunisia); El-Ghozzi, Malika [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Chadeyron, Geneviève [Université Clermont Auvergne, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS/UBP/SIGMA, BP 10448, F-63000 Clermont-Ferrand (France); Avignant, Daniel [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Zambon, Daniel, E-mail: Daniel.Zambon@univ-bpclermont.fr [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France)

2017-04-15

Isothermal sections of the diagram representing phase relationships in the NaF-CdO-NaPO{sub 3} system have been investigated by solid state reactions and powder X-ray diffraction. This phase diagram investigation confirms the polymorphism of the NaCdPO{sub 4} side component and the structure of the ß high temperature polymorph (orthorhombic, space group Pnma and unit cell parameters a=9.3118(2), b=7.0459(1), c=5.1849(1) Å has been refined. A new fluorophosphate, Na{sub 2}CdPO{sub 4}F, has been discovered and its crystal structure determined and refined from powder X-ray diffraction data. It exhibits a new 3D structure with orthorhombic symmetry, space group Pnma and unit cell parameters a=5.3731(1), b=6.8530(1), c=12.2691(2) Å. The structure is closely related to those of the high temperature polymorph of the nacaphite Na{sub 2}CaPO{sub 4}F and the fluorosilicate Ca{sub 2}NaSiO{sub 4}F but differs essentially in the cationic repartition since the structure is fully ordered with one Na site (8d) and one Cd site (4c). Relationships with other Na{sub 2}M{sup II}PO{sub 4}F (M{sup II}=Mg, Ca, Mn, Fe, Co, Ni) have been examined and the crystal-chemical and topographical analysis of these fluorophosphates is briefly reviewed. IR, Raman, optical and {sup 19}F, {sup 23}Na, {sup 31}P MAS NMR characterizations of Na{sub 2}CdPO{sub 4}F have been investigated. - Graphical abstract: The structure of the compound Na{sub 2}CdPO{sub 4}F, discovered during the study of the phase relationships in the NaF-CdO-NaPO{sub 3} system, has been determined and compared with other Na{sub 2}M{sup II}PO{sub 4}F fluorophosphates. - Highlights: • XRD analysis of the isothermal section of the NaF-CdO-NaPO{sub 3} system at 923 K. • Rietveld refinement of the high temperature polymorph β-NaCdPO{sub 4}. • Crystal structure of the new Na{sub 2}CdPO{sub 4}F fluorophosphate determined from powder XRD. • Crystal structure - composition relationships of Na{sub 2}M{sup II}PO{sub 4}F compounds

Mechanochemical transformations in Li(Na)AlH4-Li(Na)NH2 systems

International Nuclear Information System (INIS)

Dolotko, Oleksandr; Zhang Haiqiao; Ugurlu, Ozan; Wiench, Jerzy W.; Pruski, Marek; Scott Chumbley, L.; Pecharsky, Vitalij

2007-01-01

Mechanochemical transformations of tetrahydroaluminates and amides of lithium and sodium have been investigated using gas volumetric analysis, X-ray powder diffraction, solid-state nuclear magnetic resonance (NMR) and transmission electron microscopy. In a transformation of LiAlH 4 and LiNH 2 taken in an 1:1 molar ratio, the amount of released hydrogen (6.6 wt.% after 30 min ball milling) was higher than in any known one pot mechanochemical process involving a hydrogen-containing solid. A total of 4.3 wt.% of hydrogen is released by the NaAlH 4 -NaNH 2 system after 60 min ball milling; and 5.2 wt.% H 2 is released when LiAlH 4 and NaNH 2 or NaAlH 4 and LiNH 2 are ball milled for 90 min and 120 min, respectively. All transformations proceed at room temperature. The mechanism of the overall transformation MAlH 4 (s) + MNH 2 (s) → 2MH(s) + AlN(s) + 2H 2 (g) was identified based on detailed spectroscopic analysis of the intermediate (M 3 AlH 6 ) and final products of the ball milling process

Makosa Yanayofanywa na Wanafunzi Wanaojifunza Kiswahili kama ...

African Journals Online (AJOL)

Makala haya, yanashughulika na makosa ambayo hufanywa na wanafunzi wanaojifunza Kiswahili kama lugha ya pili katika shule za sekondari nchini Uganda. Mtafiti ameyaainisha makosa mbalimbali na kuyaeleza kiusahihi. Makala yanaeleza namna ambavyo makosa hayo hutokea. Yaani, kama ni makosa ...

La importancia de introducir la competencia intercultural en la educación superior: Propuesta de actividades prácticas

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María Martínez-Lirola

2017-09-01

Full Text Available Enseñar una lengua extranjera como el inglés lleva consigo no solo enseñar contenidos relacionados con la lengua objeto de estudio, sino también introducir aspectos culturales que ayuden a aprender la lengua enmarcada en la cultura. Este artículo es una contribución de cómo introducir aspectos culturales en el aula de lengua extranjera en la educación superior. Se diseñaron distintas actividades cooperativas que favorecían la adquisición de la competencia intercultural, y se optó por una metodología cooperativa para facilitar que el alumnado asumiera un papel activo y adquiriera competencias sociales. Además, se preparó una encuesta con el fin de conocer su opinión sobre distintos aspectos relacionados con la competencia intercultural. El alumnado participante en el estudio cursaba la asignatura obligatoria Lengua Inglesa V en el tercer curso del grado en Estudios Ingleses. Se presentan los resultados por ser significativos, debido a la importancia que el alumnado le concede a esta competencia y a cómo valora positivamente trabajar con ella en las actividades propuestas. Se concluye que es fundamental introducir esta competencia en el siglo XXI, con el fin de que el alumnado crezca como ciudadanía global y la docencia esté unida a las demandas sociales.

Učinak video igre "Flappy Bird" na adolescente

OpenAIRE

Horvat, Marija

2018-01-01

Ovaj diplomski rad nastoji predstaviti uvid u učinke videoigre Flappy Bird na adolescente, fokusirajući se pritom na to potiče li ona nasilno ponašanje te nastoji odgovoriti na pitanje koliko je ta videoigra bila popularna među adolescentima u Hrvatskoj te po čemu je smatraju posebnom, tj. specifičnom. U tu svrhu provedeno je anketno istraživanje, a isti anketni upitnik proveden je na terenu i putem interneta te su uspoređeni rezultati. Anketni upitnik konstruiran je na način da se prvi dio u...

LACTOSUERO: IMPORTANCIA EN LA INDUSTRIA DE ALIMENTOS WHEY: IMPORTANCE IN THE FOOD INDUSTRY

Directory of Open Access Journals (Sweden)

Ricardo Adolfo Parra Huertas

2009-06-01

Full Text Available El lactosuero de quesería es un subproducto líquido obtenido después de la precipitación de la caseína durante la elaboración del queso. Contiene principalmente lactosa, proteínas como sustancias de importante valor nutritivo, minerales, vitaminas y grasa. La composición y tipo de lactosuero varía considerablemente dependiendo del tipo de leche, tipo de queso elaborado y el proceso de tecnología empleado. La lactosa es el principal componente nutritivo (4,5 % p-v, proteína (0,8% p/v, y lípidos (0,5%. Si en la coagulación de la leche se utiliza enzimas el lactosuero se denomina dulce, y si se reemplaza la enzima por ácidos orgánicos se denomina ácido. Para la industria alimentaria, el lactosuero constituye una fuente económica de proteínas que otorga múltiples propiedades en una amplia gama de alimentos. Los productos del suero, incluyendo la lactosa, mejoran la textura, realzan el sabor y color, emulsifican y estabilizan, mejoran las propiedades de flujo y muestran muchas otras propiedades funcionales que aumentan la calidad de los productos alimenticios. Basados en el valor nutricional del lactosuero, un número de usos comerciales se han obtenido como etanol, ácidos orgánicos, bebidas no alcohólicas, bebidas fermentadas, biomasa, concentrados, aislados e hidrolizados de proteína, películas comestibles, medio de soporte para encapsular sustancias, producción de xantana, enzimas, separación de la lactosa para fines endulzantes en alimentos entre otras aplicaciones.Cheese whey is a by-product liquid obtained after precipitation of casein during the production cheese. Mainly contains lactose, protein and important nutritional substances, minerals, vitamins and fat. The type and composition of whey varies considerably depending on the type of milk, cheese produced and the process technology used. Lactose is the primary nutritional component (4.5% pv, protein (0.8% w / v and lipids (0.5%. If the milk clotting enzyme used is

Perinatal Na+ Overload Programs Raised Renal Proximal Na+ Transport and Enalapril-Sensitive Alterations of Ang II Signaling Pathways during Adulthood

Science.gov (United States)

Cabral, Edjair V.; Vieira-Filho, Leucio D.; Silva, Paulo A.; Nascimento, Williams S.; Aires, Regina S.; Oliveira, Fabiana S. T.; Luzardo, Ricardo; Vieyra, Adalberto; Paixão, Ana D. O.

2012-01-01

Background High Na+ intake is a reality in nowadays and is frequently accompanied by renal and cardiovascular alterations. In this study, renal mechanisms underlying perinatal Na+ overload-programmed alterations in Na+ transporters and the renin/angiotensin system (RAS) were investigated, together with effects of short-term treatment with enalapril in terms of reprogramming molecular alterations in kidney. Methodology/Principal Findings Male adult Wistar rats were obtained from dams maintained throughout pregnancy and lactation on a standard diet and drinking water (control) or 0.17 M NaCl (saline group). Enalapril (100 mg/l), an angiotensin converting enzyme inhibitor, was administered for three weeks after weaning. Ninety day old offspring from dams that drank saline presented with proximal tubules exhibiting increased (Na++K+)ATPase expression and activity. Ouabain-insensitive Na+-ATPase activity remained unchanged but its response to angiotensin II (Ang II) was lost. PKC, PKA, renal thiobarbituric acid reactive substances (TBARS), macrophage infiltration and collagen deposition markedly increased, and AT2 receptor expression decreased while AT1 expression was unaltered. Early treatment with enalapril reduced expression and activity of (Na++K+)ATPase, partially recovered the response of Na+-ATPase to Ang II, and reduced PKC and PKA activities independently of whether offspring were exposed to high perinatal Na+ or not. In addition, treatment with enalapril per se reduced AT2 receptor expression, and increased TBARS, macrophage infiltration and collagen deposition. The perinatally Na+-overloaded offspring presented high numbers of Ang II-positive cortical cells, and significantly lower circulating Ang I, indicating that programming/reprogramming impacted systemic and local RAS. Conclusions/Significance Maternal Na+ overload programmed alterations in renal Na+ transporters and in its regulation, as well as severe structural lesions in adult offspring. Enalapril

alpha-Adducin mutations increase Na/K pump activity in renal cells by affecting constitutive endocytosis: implications for tubular Na reabsorption.

Science.gov (United States)

Torielli, Lucia; Tivodar, Simona; Montella, Rosa Chiara; Iacone, Roberto; Padoani, Gloria; Tarsini, Paolo; Russo, Ornella; Sarnataro, Daniela; Strazzullo, Pasquale; Ferrari, Patrizia; Bianchi, Giuseppe; Zurzolo, Chiara

2008-08-01

Genetic variation in alpha-adducin cytoskeletal protein is implicated in the polymerization and bundling of actin and alteration of the Na/K pump, resulting in abnormal renal sodium transport and hypertension in Milan hypertensive rats and humans. To investigate the molecular involvement of alpha-adducin in controlling Na/K pump activity, wild-type or mutated rat and human alpha-adducin forms were, respectively, transfected into several renal cell lines. Through multiple experimental approaches (microscopy, enzymatic assays, coimmunoprecipitation), we showed that rat and human mutated forms increased Na/K pump activity and the number of pump units; moreover, both variants coimmunoprecipitate with Na/K pump. The increased Na/K pump activity was not due to changes in its basolateral localization, but to an alteration of Na/K pump residential time on the plasma membrane. Indeed, both rat and human mutated variants reduced constitutive Na/K pump endocytosis and similarly affected transferrin receptor trafficking and fluid-phase endocytosis. In fact, alpha-adducin was detected in clathrin-coated vesicles and coimmunoprecipitated with clathrin. These results indicate that adducin, besides its modulatory effects on actin cytoskeleton dynamics, might play a direct role in clathrin-dependent endocytosis. The constitutive reduction of the Na/K pump endocytic rate induced by mutated adducin variants may be relevant in Na-dependent hypertension.

VPLIV OSEBNOSTI NA STILE VODENJA

OpenAIRE

Vučak, Petra

2009-01-01

Nekatere naše vrline krasijo zlate lastnosti, druge pa kvarijo sivi odtenki. Če bi ljudje razumeli in spoznali svojo osebnost, ter osebnostne tipe drugih ljudi, bi se problemi pri komunikaciji občutno zmanjšali. Takrat bi namreč lažje uvideli, zakaj je nekdo reagiral na način, kot je ali zakaj je nekdo dejal to, kar je. Smisel tega je, da spoznamo svoje dobre lastnosti, ki jih lahko še bolj razvijemo, slabe pa poskušamo nadzorovati in tako zmanjšati njihov vpliv. Iskanje uspešnih in učink...

VPLIV CENE NA ZADOVOLJSTVO IN ZVESTOBO UPORABNIKOV TELEKOMUNIKACIJSKIH STORITEV

OpenAIRE

Majcen, Mateja

2016-01-01

Cena izdelka ali storitve, ki jo plača uporabnik, ima pomemben vpliv na zadovoljstvo ali nezadovoljstvo uporabnika z uporabo tega izdelka ali storitve in posledično na zadovoljstvo do podjetja. Glede na to, da se različni avtorji strinjajo in to tudi dokazujejo z raziskavami, zadovoljstvo nedvoumno vpliva na zvestobo uporabnika, zvestoba pa na dolgoročno uspešnost podjetja, smo v delu ugotavljali, kako sama cena storitve vpliva na zadovoljstvo in kako posredno preko zadovoljstva vpliva na zve...

NaI(Tl) electron energy resolution

CERN Document Server

Mengesha, W

2002-01-01

NaI(Tl) electron energy resolution eta sub e was measured using the Modified Compton Coincidence Technique (MCCT). The MCCT allowed detection of nearly monoenergetic internal electrons resulting from the scattering of incident 662 keV gamma rays within a primary NaI(Tl) detector. Scattered gamma rays were detected using a secondary HPGe detector in a coincidence mode. Measurements were carried out for electron energies ranging from 16 to 438 keV, by varying the scattering angle. Measured HPGe coincidence spectra were deconvolved to determine the scattered energy spectra from the NaI(Tl) detector. Subsequently, the NaI(Tl) electron energy spectra were determined by subtracting the energy of scattered spectra from the incident source energy (662 keV). Using chi-squared minimization, iterative deconvolution of the internal electron energy spectra from the measured NaI(Tl) spectra was then used to determine eta sub e at the electron energy of interest. eta sub e values determined using this technique represent va...

Quantitative (23) Na MRI of human knee cartilage using dual-tuned (1) H/(23) Na transceiver array radiofrequency coil at 7 tesla.

Science.gov (United States)

Moon, Chan Hong; Kim, Jung-Hwan; Zhao, Tiejun; Bae, Kyongtae Ty

2013-11-01

To develop quantitative dual-tuned (DT) (1) H/(23) Na MRI of human knee cartilage in vivo at 7 Tesla (T). A sensitive (23) Na transceiver array RF coil was developed at 7T. B1 fields generated by the transceiver array coil were characterized and corrected in the (23) Na images. Point spread function (PSF) of the (23) Na images was measured, and the signal decrease due to partial-volume-effect was compensated in [(23) Na] quantification of knee cartilage. SNR and [(23) Na] in anterior femoral cartilage were measured from seven healthy subjects. SNR of (23) Na image with the transceiver array coil was higher than that of birdcage coil. SNR in the cartilage at 2-mm isotropic resolution was 26.80 ± 3.69 (n = 7). B1 transmission and reception fields produced by the DT coil at 7T were similar to each other. Effective full-width-half-maximum of (23) Na image was ∼5 mm at 2-mm resolution. Mean [(23) Na] was 288.13 ± 29.50 mM (n = 7) in the anterior femoral cartilage of normal subjects. We developed a new high-sensitivity (23) Na RF coil for knee MRI at 7T. Our (1) H/(23) Na MRI allowed quantitative measurement of [(23) Na] in knee cartilage by measuring PSF and cartilage thickness from (23) Na and (1) H image, respectively. Copyright © 2013 Wiley Periodicals, Inc.

Razvitak naselja na kvarnerskim otocima - primjer Dobrinja

Directory of Open Access Journals (Sweden)

Marijan Bradanović

2012-12-01

Full Text Available Na dosad slabo poznatom i sa stajališta povijesti umjetnosti još posve neobrađenom primjeru Dobrinja na otoku Krku, raspravlja se o razvitku naselja na kvarnerskim otocima. Uz isticanje štetnosti dosad prevladavajućih uopćavanja, karakteristični položaj i razvitak Dobrinja tumače se u širem, komparativnom kontekstu. Analiziraju se prostiranje i obilježja pojedinih dijelova ovog naselja, a naglasak je na vremenu kasnog srednjeg i ranijeg novog vijeka. Tada je najuži dio povijesnog središta Dobrinja poprimio čvrstu, na tlorisnoj osnovi i danas, usprkos opsežnim pregradnjama i arhitektonskim preinakama, jasno uočljivu, urbanu fizionomiju.

La autoevaluación institucional y su importancia en la educación superior Institutional self-appraisal and its importance in higher education

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Ricardo Figueroa Toala

2012-12-01

Full Text Available La autoevaluación institucional actualmente responde a las demandas de lograr una Universidad que esté a tono con los avances de la sociedad y a su vez se convierta en un reflejo de ella. En el artículo se realiza una valoración conceptual de las concepciones existentes sobre este proceso. Asimismo se ofrece una panorámica de las tendencias referidas a las diversas maneras de visualizar este fenómeno de innegable importancia para la vida y permanencia de las instituciones de educación superior.Nowadays, institutional self-appraisal meets the demands of creating a university that keeps up with the new advances of society, and at the same time a university that becomes the reflection of its society. A conceptual assessment of the existing conceptions of this process is carried out in this article. Likewise, it is given a panoramic view of the tendencies referring to the different ways of visualizing this phenomenon of undeniable importance for the life and permanence of the higher education institutions.

Investigation of sodalites for conditioning halide salts (NaCl and NaI): Comparison of two synthesis routes

Energy Technology Data Exchange (ETDEWEB)

Bardez, Isabelle; Campayo, Lionel; Rigaud, Danielle; Chartier, Myriam; Calvet, Aurelie [CEA, Laboratoire d' Etudes des Materiaux Ceramiques pour le Conditionnement, Site de Marcoule, Batiment 208, B.P. 17171, 30207 Bagnols sur Ceze cedex (France)

2008-07-01

Sodalites with the general formula Na{sub 8}Al{sub 6}Si{sub 6}O{sub 24}X{sub 2} (where X = Cl or I) were investigated for ceramic conditioning of halide salts (NaCl and NaI). Because of the tendency of halides to volatilize at high temperature, two synthesis routes were tested to optimize the halide content in the sodalite phase. The first is based on heating at high temperature of a [nepheline NaAlSiO{sub 4} + salt] mixture prepared by a dry process. The second, performed at low temperature, consists of the reaction in aqueous media between kaolinite (Al{sub 2}Si{sub 2}O{sub 5}(OH){sub 4}), sodium hydroxide (NaOH) and the salt. The present study compares these two syntheses and examines differences between chloro-sodalite and iodo-sodalite based on X-ray diffraction and infrared spectroscopy. The next step will consist in sintering the resulting powder samples to obtain dense ceramics. (authors)

PUBLIC HEALTH ETHICS: TOWARDS A RESEARCH AGENDA ÉTICA EN SALUD PÚBLICA: HACIA UNA AGENDA DE INVESTIGACIÓN ÉTICA NA SAÚDE PÚBLICA: EM DIREÇÃO A UM TEMÁRIO DE PESQUISAS

Directory of Open Access Journals (Sweden)

Alison Thompson

2003-01-01

tópicos que emergieron de los artículos clave desarrollados para el simposio y discutirá su importancia para el emergente campo de la ética de la salud pública. Temas significativos fueron identificados, tales como la importancia de distinguir la ética en salud pública de la bioética tradicional; el desarrollo de la noción de intereses comunes; amplias definiciones de salud pública, que incluyen las fuentes de las inequidades en salud, y una comprensión del campo teórico desde el cual ha emergido la ética en salud públicaA ética na saúde pública, como diferente da bioética clínica/médica, é um campo do estudo emergente na área acadêmica. Segundo uma parte de um maior esforço para abordar o conteúdo e os limites que esse campo tem ou deve ter, um grupo da Universidade de Toronto levou a cabo um Simpósio Internacional para tratar e definir um programa da pesquisa para a ética na saúde pública. O Simpósio, levado a cabo em maio de 2002, organizou-se ao redor de quatro maiores áreas da inquietude ética pela saúde pública: direitos individuais e bem comun; riscos e a precaução; a vigilância e regulamentação; e a justiça social e a equidade na saúde global. Esse artigo conterá um panorama com alguns dos temas principais que originanse dos artigos chave desenvolvidos para o simpósio e debatera e tratará sua importância para o campo emergente da ética da saúde pública. Temas significativos identificaram-se, como a importância de distinguir a ética na saúde pública da bioética tradicional; o desenvolvimento da noção de juros comuns; definições amplas de saúde pública, que incluem as fontes das inequidades na saúde, e uma compreensão da estrutura teórica do que tem surgido a ética na saúde pública

Dissolution of targets for the production of Mo-99: Part 1. Influence of NaOH concentration and the addition of NaNO3 and NaNO2 on the dissolution time

International Nuclear Information System (INIS)

Camilo, Ruth L.; Araujo, Izilda da C.; Mindrisz, Ana C.; Forbicini, Christina A.L.G. de O.

2011-01-01

Faced with global crisis in the production of radioisotope 99 Mo, which product of decay, 99 mTc, is the tracer element most often used in nuclear medicine and accounts for about 80% of all diagnostic procedures in vivo, since September 2008 Brazil is developing the project called Brazilian Multipurpose Reactor (RMB). Within the Brazilian Nuclear Program (PNB) the construction of the RMB, is seen as a long term solution to meet all domestic demand relative to the supply of radioisotopes and radiopharmaceuticals. In the process to be studied to obtain 99 Mo from irradiated UA1 x -A1 LEU targets employing alkaline dissolution, processing time should be minimized, considering the short half life of 99 Mo and 99 mTc, about 66 h and 6 h, respectively. That makes dissolution time a significant factor in the development of the process. This paper presents the results of alkaline dissolution of scraps of Al, used to simulate the dissolution process of UA1 x -A1 targets. Al corresponds to about 79% of the total weight of the UA1 x -A1 target. The effect of NaOH concentration on dissolution time for the interval of 1 to 3.5 mol.L-1 was studied, keeping the molar ratio in 1Al:2.16NaOH and the initial temperature of 88 degree C. The influence of reagent composition over dissolution time was studied using three different solutions: a) 3 mol.L -1 NaOH, b) 3 mol.L -1 NaOH/NaNO 3 and c) 3 mol.L -1 NaOH/NaNO 2 , keeping the same molar ratio and temperature. The results showed that the dissolution time decreases with increasing NaOH concentration and the addition of NaNO 3 or NaNO 2 in the NaOH solution reduces both dissolution time and volume of gases released. (author)

Haplotipos de la hemoglobina S: importancia epidemiológica, antropológica y clínica

Directory of Open Access Journals (Sweden)

Walter E. Rodríguez Romero

1998-01-01

Full Text Available La relación entre la drepanocitosis y los diferentes haplotipos del gen que codifica la subunidad betas de la globina ha permitido llegar a entender mejor las manifestaciones clínicas de aquella enfermedad. El uso de mejores técnicas de laboratorio permite descartar la presencia de otros factores hereditarios capaces de ocultar el verdadero genotipo hemoglobínico. La heterogeneidad clínica de la drepanocitosis, afección caracterizada por la presencia de una hemoglobina anormal denominada HbS, depende de las concentraciones de hemoglobina fetal (HbF, la razón de cadenas Ggamma a cadenas Agamma en la molécula de globina, las concentraciones de 2,3-difosfoglicerato, la presencia de mutaciones ligadas, los haplotipos del gen betas, la presencia simultánea de alfa-talasemia, y factores ambientales. En particular, los polimorfismos Senegal y árabe-saudí o indio del conglomerado de genes que codifican la subunidad betas se asocian con una evolución clínica menos grave, mientras que los haplotipos de la República Centroafricana (CAR o Bantú, Camerún y Benín se asocian con drepanocitosis grave. De todos, el haplotipo CAR es el de peor pronóstico (concentraciones de HbF de menos de 12% y razón de Ggamma:Agamma propia de la edad adulta. Estos polimorfismos del ácido desoxirribonucleico, una vez caracterizados, adquieren enorme importancia como marcadores antropológicos y genéticos. En las Américas, los haplotipos betas permiten entender mejor las raíces ancestrales africanas de las poblaciones de raza negra. Se ha comprobado la presencia de variedad genética no solo entre las diferentes poblaciones negras de las Américas, sino también dentro de un mismo país, como se observa en Costa Rica.

MOTIVACIÓN: PERSPECTIVAS TEÓRICAS Y ALGUNAS CONSIDERACIONES DE SU IMPORTANCIA EN EL ÁMBITO EDUCATIVO

Directory of Open Access Journals (Sweden)

María Luisa Naranjo Pereira

2009-01-01

Full Text Available Este artículo tiene como propósito revisar el concepto de motivación, su evolución histórica, los tres principales enfoques relacionados con esta, a saber, conductual, humanista y cognitivo; y, además, presentar algunos aspectos de importancia sobre la motivación en el ámbito educativo. El enfoque conductual enfatiza que las personas actúan motivadas por beneficios o recompensas que puedan recibir. El humanista subraya las cualidades del ser humano, su capacidad para desarrollarse y su libertad de elección. De este enfoque se estudian las teorías motivacionales: Jerarquía de las necesidades de Maslow, Existencia, relación y crecimiento de Alderfer y la Teoría de las necesidades de McClelland. El enfoque cognitivo señala que lo que se piensa que puede ocurrir determina lo que sucede; así, las percepciones de los eventos influyen sobre las emociones y los comportamientos. Si la persona cree que fracasará es probable que fracase y si piensa que tendrá éxito posiblemente lo logre. En esta perspectiva, los pensamientos guían la motivación. De este enfoque se revisa la Teoría de las expectativas de Vroom, la Teoría de la equidad de Adams y el Modelo de fijación de metas y objetivos al que se refiere Trechera. Sobre el ámbito educativo se analiza especialmente la relación entre emoción y motivación y la relación entre la Teoría de las atribuciones y el desempeño académico. Se presentan algunos motivos que pueden orientar el comportamiento estudiantil y, finalmente, se estudian las motivaciones intrínseca y extrínseca, y su influencia en el rendimiento académico del estudiantado.

Magnetic upconverting fluorescent NaGdF4:Ln3+ and iron-oxide@NaGdF4:Ln3+ nanoparticles

Science.gov (United States)

Shrivastava, Navadeep; Rocha, Uéslen; Muraca, Diego; Jacinto, Carlos; Moreno, Sergio; Vargas, J. M.; Sharma, S. K.

2018-05-01

Microwave assisted solvothermal method has been employed to synthesize multifunctional upconverting β-NaGdF4:Ln3+ and magnetic-upconverting Fe3O4/γ-Fe2O3@NaGdF4:Ln3+ (Ln = Yb and Er) nanoparticles. The powder x-ray diffraction data confirms the hexagonal structure of NaGdF4:Ln3+ and high resolution transmission electron microscopy shows the formation of rod shaped NaGdF4:Ln3+ (˜ 20 nm) and ovoid shaped Fe3O4/γ-Fe2O3@NaGdF4:Ln3+ (˜ 15 nm) nanoparticles. The magnetic hysteresis at 300 K for β-NaGdF4:Ln3+ demonstrates paramagnetic features, whereas iron-oxide@β-NaGdF4:Ln3+ exhibits superparamagnetic behavior along with a linear component at large applied field due to paramagnetic NaGdF4 matrix. Both nanoparticle samples provide an excellent green emitting [(2H11/2, 4S3/2)→4I15/2 (˜ 540 nm)] upconversion luminescence emission under excitation at 980 nm. The energy migration between Yb and Er in NaGdF4 matrix has been explored from 300-800 nm. Intensity variation of blue, green and red lines and the observed luminescence quenching due to the presence of Fe3O4/γ-Fe2O3 in the composite has been proposed. These kinds of materials contain magnetic and luminescence characteristics into single nanoparticle open new possibility for bioimaging applications.

The plant vacuolar Na+/H+ antiport.

Science.gov (United States)

Barkla, B J; Apse, M P; Manolson, M F; Blumwald, E

1994-01-01

Salt stress imposes severe limitations on plant growth, however, the extent of growth reduction depends upon the soil salinity level and the plant species. One of the mechanisms employed by salt tolerant plants is the effective vacuolar compartmentalization of sodium. The sequestration of sodium into the vacuole occurs by the operation of a Na+/H+ antiport located at the tonoplast. Evidence for a plant vacuolar Na+/H+ antiport has been demonstrated in tissues, intact vacuoles and isolated tonoplast vesicles. In sugar beet cell suspensions, the activity of the vacuolar Na+/H+ antiport increased with increasing NaCl concentrations in the growth medium. This increased activity was correlated with the increased synthesis of a 170 kDa tonoplast polypeptide. In vivo labelling of tonoplast proteins showed the enhanced synthesis of the 170 kDa polypeptide not only upon exposure of the cells to salt, but also when the cells were grown in the presence of amiloride. Exposure of the cells to amiloride also resulted in increased vacuolar Na+/H+ antiport activity. Polyclonal antibodies raised against the 170 kDa polypeptide almost completely inhibited the antiport activity, suggesting the association of this protein with the plant vacuolar Na+/H+ antiport. Antibodies against the Na+/H+ antiport-associated polypeptide were used to screen a Beta lambda ZAP expression library. A partial clone of 1.65 kb was sequenced and found to encode a polypeptide with a putative transmembrane domain and a large hydrophilic C terminus. This clone showed no homology to any previously cloned gene at either the nucleic acid or the amino acid level.

Correlation of the Na2SiO3 to NaOH Ratios and Solid to Liquid Ratios to the Kedah’s Soil Strength

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Nur Hamzah Hazamaah

2016-01-01

Full Text Available Geopolymer was used for the soil stabilization of Kedah’s soil at different ratios of solid to liquid and Na2SiO3 to NaOH in order to achieve the desired compressive strength. The geopolymerization process which produces an aluminosilicate gel was occurred due to the mixing of Kedah’s soil and fly ash with Na2SiO3 and NaOH. Soil stabilization by geopolymer was synthesized by the activation of fly ash and Kedah’s soil with Na2SiO3 and NaOH at different ratios of solid to liquid (1.5, 2.0, 2.5 and 3.0 and Na2SiO3 to NaOH (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 at a specific constant concentration of NaOH solution of 6M. The compressive strength up to 5.12 MPa was obtained at 3.0 of solid to liquid ratio and 2.5 of Na2SiO3 to NaOH ratio in 7 days curing at room temperature.

Near resonant charge transfer in Na(4D)+K+ → Na++K*: Optical pumping of the Na(4D) state and energy dependence of rank 4 alignment

International Nuclear Information System (INIS)

Campbell, E.E.B.; Huelser, H.; Witte, R.; Hertel, I.V.

1990-01-01

Rank 4 alignment has been observed in a quasi one electron system. Relative charge transfer cross sections of the Na 4dσ, 4dπ and 4dδ sublevels for the K + +Na(4D)→K * +Na + system have been measured. A strong energy dependence is observed. The results at energies less than 1 keV may be attributed to rotational coupling of the Na 4dπ state to the K 4fδ state. The Na atom is excited in a two-step process, the first step being excitation to the 3 2 P 3/2 level with a two-mode laser to pump from both hyperfine levels of the ground state simultaneously. This two-mode laser is described in detail. The optical pumping problem is solved using rate equations. The general formula for describing the scattering intensity for cylindrical symmetry, in terms of multipole moments, for atoms excited by two linearly polarised lasers is derived and used to evaluate the experimental results. (orig.)

Thermodynamic description of Tc(iv) solubility and carbonate complexation in alkaline NaHCO3-Na2CO3-NaCl systems.

Science.gov (United States)

Baumann, A; Yalçıntaş, E; Gaona, X; Polly, R; Dardenne, K; Prüßmann, T; Rothe, J; Altmaier, M; Geckeis, H

2018-03-28

The solubility of 99 Tc(iv) was investigated in dilute to concentrated carbonate solutions (0.01 M ≤ C tot ≤ 1.0 M, with C tot = [HCO 3 - ] + [CO 3 2- ]) under systematic variation of ionic strength (I = 0.3-5.0 M NaHCO 3 -Na 2 CO 3 -NaCl-NaOH) and pH m (-log[H + ] = 8.5-14.5). Strongly reducing conditions (pe + pH m ≈ 2) were set with Sn(ii). Carbonate enhances the solubility of Tc(iv) in alkaline conditions by up to 3.5 log 10 -units compared to carbonate-free systems. Solvent extraction and XANES confirmed that Tc was kept as +IV during the timeframe of the experiments (≤ 650 days). Solid phase characterization performed by XAFS, XRD, SEM-EDS, chemical analysis and TG-DTA confirmed that TcO 2 ·0.6H 2 O(am) controls the solubility of Tc(iv) under the conditions investigated. Slope analysis of the solubility data in combination with solid/aqueous phase characterization and DFT calculations indicate the predominance of the species Tc(OH) 3 CO 3 - at pH m ≤ 11 and C tot ≥ 0.01 M, for which thermodynamic and activity models are derived. Solubility data obtained above pH m ≈ 11 indicates the formation of previously unreported Tc(iv)-carbonate species, possibly Tc(OH) 4 CO 3 2- , although the likely formation of additional complexes prevents deriving a thermodynamic model valid for this pH m -region. This work provides the most comprehensive thermodynamic dataset available for the system Tc 4+ -Na + -Cl - -OH - -HCO 3 - -CO 3 2- -H 2 O(l) valid under a range of conditions relevant for nuclear waste disposal.

Stimulation of Na+/K+ ATPase activity and Na+ coupled glucose transport by β-catenin

International Nuclear Information System (INIS)

Sopjani, Mentor; Alesutan, Ioana; Wilmes, Jan; Dermaku-Sopjani, Miribane; Lam, Rebecca S.; Koutsouki, Evgenia; Jakupi, Muharrem; Foeller, Michael; Lang, Florian

2010-01-01

Research highlights: → The oncogenic transcription factor β-catenin stimulates the Na + /K + -ATPase. → β-Catenin stimulates SGLT1 dependent Na + , glucose cotransport. → The effects are independent of transcription. → β-Catenin sensitive transport may contribute to properties of proliferating cells. -- Abstract: β-Catenin is a multifunctional protein stimulating as oncogenic transcription factor several genes important for cell proliferation. β-Catenin-regulated genes include the serum- and glucocorticoid-inducible kinase SGK1, which is known to stimulate a variety of transport systems. The present study explored the possibility that β-catenin influences membrane transport. To this end, β-catenin was expressed in Xenopus oocytes with or without SGLT1 and electrogenic transport determined by dual electrode voltage clamp. As a result, expression of β-catenin significantly enhanced the ouabain-sensitive current of the endogeneous Na + /K + -ATPase. Inhibition of vesicle trafficking by brefeldin A revealed that the stimulatory effect of β-catenin on the endogenous Na + /K + -ATPase was not due to enhanced stability of the pump protein in the cell membrane. Expression of β-catenin further enhanced glucose-induced current (Ig) in SGLT1-expressing oocytes. In the absence of SGLT1 Ig was negligible irrespective of β-catenin expression. The stimulating effect of β-catenin on both Na + /K + ATPase and SGLT1 activity was observed even in the presence of actinomycin D, an inhibitor of transcription. The experiments disclose a completely novel function of β-catenin, i.e. the regulation of transport.

Explosive phenomena in heavily irradiated NaCl

NARCIS (Netherlands)

denHartog, HW; Vainshtein, DI; Matthews, GE; Williams, RT

1997-01-01

In heavily irradiated NaCl crystals explosive phenomena can be initiated during irradiation or afterwards when samples are heated to temperatures between 100 and 250 degrees C. During irradiation of NaCl Na and Cl-2 precipitates and void structures are produced along with the accumulation of stored

Crystallographic characterization of cement pastes hydrated with NaCl; Caracterizacao cristalografica de pastas de cimento hidratadas com NaCl

Energy Technology Data Exchange (ETDEWEB)

Melo, Carina Gabriela de Melo e; Martinelli, Antonio Eduardo; Melo, Dulce Maria Araujo; Melo, Marcus Antonio de Freitas; Melo, Vitor Rodrigo de Melo e [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2012-07-01

One of the major current challenges faced by oil companies is the exploration of pre salt basins. Salt layers deposited upon the evaporation of ocean water and continental separation are mainly formed by NaCl and isolate immense oil reservoirs. The mechanical stability and zonal isolation of oil wells that run through salt layers must be fulfilled by cement sheaths saturated with NaCl to assure chemical compatibility between cement and salt layer. The present study aimed at evaluating the effect of NaCl addition on the hydration of oil well cement slurries as well as identifying the nature of crystalline phases present in the hardened cement. To that end, cement slurries containing NaCl were mixed, hardened and characterized by X-ray diffraction. The results revealed that the presence of NaCl affects the formation of hydration products by the presence of Friedel's salt. The intensity of the corresponding peaks increase as the contents of NaCl in the slurry increase. High concentrations of NaCl in Portland slurries increase the setting time of cement and the presence of Friedel's salt decreases the strength of the hardened cement. (author)

Estereótipos na comunicação intercultural: o caso do intercâmbio cultural na PUCRS

OpenAIRE

Espindola, Polianne Merie

2010-01-01

Este é um estudo da estereotipia existente na comunicação intercultural. O objetivo é entender a natureza do estereótipo mental e seu papel na comunicação entre interlocutores de culturas distintas. Para tanto, observa os estudantes estrangeiros em programas de intercâmbio no campus da Pontifícia Universidade Católica do Rio Grande do Sul. O estudo define o conceito de estereótipo e explicita seu papel na comunicação intercultural; verifica sua relevância na construção das narrativas entre cu...

VPLIV ULCEROZNEGA KOLITISA NA KAKOVOST ŽIVLJENJA

OpenAIRE

Dugi, Maja

2015-01-01

Pri vsaki bolezni je zelo pomembna kakovost življenja pacientov. Ulcerozni kolitis je kronična bolezen, ki je znana po obdobjih mirovanja in izbruhov, kar definitivno vpliva na posameznika, ki se s tem spopada. Sooča se z raznimi omejitvami, ki vplivajo na njegov vsakdan. Rezultati raziskave so pokazali, da je kakovost življenja bolnikov z ulceroznim kolitisom izrazito okrnjena. Ne le, da se spopadajo z bolečino, ampak tudi s psihičnimi in socialnimi posledicami, ki vplivajo na fizične aktivn...

Análise do efeito imunomodulador da ouabaína na inflamação e nocicepção

OpenAIRE

Vasconcelos, Danielle Ingrid Bezerra de

2011-01-01

A Ouabaína é um glicosídeo cardiotônico, inibidor da Na+/K+-ATPase, utilizada na clínica para o tratamento de insuficiência cardíaca. Atualmente, sabe-se que essa substância é endógena, e capaz de interferir em várias funções fisiológicas, inclusive em diversos aspectos do sistema imunológico. Apesar disso, pouco se sabe sobre seu envolvimento em processos inflamatórios e nociceptivos. Neste trabalho, foi avaliada a atividade da Ouabaína na inflamação aguda desencadeada pela ad...

Erythrocyte 22Na+ influx in hypertension

International Nuclear Information System (INIS)

Shalev, O.; Eaton, J.W.; Ben-Ishay, D.

1984-01-01

We assessed 22Na+ uptake by erythrocytes (RBC) from 38 individuals with essential hypertension and 37 healthy controls. All subjects were male, white, non-obese and with normal renal function, obviating sex, race, hormonal, ponderal and renal factors known to influence RBC Na+ handling. The mean +/- sem 22Na+ uptake of the patients was 284 +/- 16 mumole/liter RBC/hour while that of normal controls was 249 +/- 11 mumole/liter RBC/hour; although the difference reached borderline significance, individual values showed considerable overlap. Consequently, in our population, RBC 22Na+ uptake is not a reliable marker for essential hypertension. We believe that previous studies should be reassessed with regard to patients' characteristics and future studies employ rigorous criteria in selection of subjects

Hannah Arendt: importancia del relato histórico y ficticio como vía para la reflexión ética y política

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Fonnegra Osorio, Claudia Patricia

2017-07-01

Full Text Available En este artículo se presenta la importancia que le da Hannah Arendt al relato histórico y ficticio como vía para la reflexión ética y política. Se estudia, en primer lugar, cómo los relatos posibilitan la configuración de la identidad, tanto de un hombre como de una comunidad, ya que la narración permite dar sentido a la fragilidad y contingencia propia de las acciones humanas. En segundo lugar se analiza de qué manera la narración permite conservar en la memoria acciones para que no sean olvidadas. Finalmente se estudia cómo el seguimiento de relatos contribuye a la comprensión del mundo humano y a potenciar la facultad de juzgar para superar pensamientos solipsistas, elemento necesario para el ejercicio de una concepción ética y política basada en el reconocimiento de la pluralidad humana.

La importancia de la enseñanza semiótica para la formación de ingenieros en la Universidad Técnica de Cotopaxi, Ecuador

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Edwin Vaca-Cerda

2016-02-01

Full Text Available En la actualidad existe un marcado desarrollo científico tecnológico especialmente en la comunicación, que tiene su incidencia en la formación del pensamiento científico en los profesionales y ello está relacionado con el dominio de habilidades en la utilización de los nuevos signos tecnológicos. De ahí que se precisa que en los centros de educación superior se tenga en cuenta el manejo adecuado del lenguaje gráfico tecnológico para estar acorde con estos sustantivos avances. Este trabajo presenta un análisis de la importancia de la enseñanza semiótica para favorecer la lectura e interpretación de signos y representaciones gráficas relacionadas con la profesión para los ingenieros, lo cual contribuye a la formación de un pensamiento y un diálogo tecnológico.

O grotesco na imagem publicitária

OpenAIRE

Silva, Maria João Barros

2013-01-01

O significado da palavra grotesco teve um começo puramente artístico numa descoberta, de imagens de figuras humanas deformadas e alteradas. No entanto, este foi evoluindo e adotando novos significados mais amplos e concretos na atualidade. É possível encontrar vários exemplos do grotesco em várias plataformas, como no cinema, na televisão e na literatura. Neste sentido, para se poder proceder ao estudo desta temática é fundamental a conquista do conhecimento sobre o estatuto do grotesco na pu...

Gravidez na adolescência: tendência na produção científica de enfermagem

OpenAIRE

Gurgel, Maria Glêdes Ibiapina; Alves, Maria Dalva Santos; Vieira, Neiva Francenely Cunha; Pinheiro, Patrícia Neyva da Costa; Barroso, Grasiela Teixeira

2008-01-01

A gravidez em adolescentes tem implicações biológica, psicológica, social, econômica e cultural. O estudo exploratório, descritivo e bibliográfico objetivou identificar as concepções da gravidez na adolescência, sujeito, vulnerabilidade e gênero, presentes na produção científica de Enfermagem. Foram selecionados intencionalmente quatro periódicos brasileiros e dois da América Latina indexados de 2002 a 2006 na Scientific Electronic Library. Dos 1.472 artigos identificados, 43 tinham como temá...

Neutralization of Na2PO4: Reaction between Na3PO4 and CaCL2

International Nuclear Information System (INIS)

Xia Shenglan; Wang Luning

1990-01-01

The results of reaction Na 3 PO 4 with CaCl 2 in water at ambient and higher temperature are described. The reaction rate of Na 3 PO 4 with CaCl 2 is slow at ambient temperature and the reaction is complete at 260 deg C after 2 h. The products are Ca(OH) 2 and Ca 5 (PO 4 ) 3 (OH). The quantity of them is dependent upon the quanity of Na 3 PO 4 and CaCl 2 contained in water, all of them control pH of water

Raman scattering and lattice stability of NaAlH{sub 4} and Na{sub 3}AlH{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Yukawa, H. [Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-Ku, Nagoya 464-8603 (Japan)], E-mail: hiroshi@numse.nagoya-u.ac.jp; Morisaku, N.; Li, Y.; Komiya, K.; Rong, R.; Shinzato, Y. [Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-Ku, Nagoya 464-8603 (Japan); Sekine, R. [Department of Chemistry, Faculty of Science, Shizuoka University, 836 Ohya, Shizuoka 422-8529 (Japan); Morinaga, M. [Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-Ku, Nagoya 464-8603 (Japan)

2007-10-31

In situ Raman spectroscopy measurements have been performed during the decomposition of NaAlH{sub 4} in order to investigate the transition from the four-coordinated complex anion, [AlH{sub 4}]{sup -}, in NaAlH{sub 4} to the six-coordinated complex anion, [AlH{sub 6}]{sup 3-}, in Na{sub 3}AlH{sub 6}. Also, the local geometry and the Al-H vibrations are analyzed theoretically by the first-principle calculations of the electronic structures. It is found that the Raman sift at 1765 cm{sup -1} for the Al-H stretching vibration in NaAlH{sub 4} shifts towards the higher frequency side, 1801 cm{sup -1} upon melting. This Raman spectrum for the liquid phase recovers to the original position when it is cooled down to room temperature before Na{sub 3}AlH{sub 6} start to appear. The Raman peak around 1800 cm{sup -1} is still observed after the decomposition of NaAlH{sub 4} occurs to precipitate Na{sub 3}AlH{sub 6}. However, this peak does not recover to its original position by cooling, but still persists in the sample cooled down to room temperature. From these results, the intermediate transition state during the decomposition of NaAlH{sub 4} into Na{sub 3}AlH{sub 6} is discussed. In addition, it is shown from a series of calculation that the highest frequency of the Al-H vibration correlates with the shortest Al-H bond length in the MAlH{sub 4}-type and its derivative complex hydrides.

Predstave o seksu u filmovima na temu postapokalipse

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Ana Banić-Grubišić

2016-03-01

Full Text Available Rad se bavi načinima predstavljanja seksualnih odnosa u filmovima na temu postapokalipse. Razmatraju se različiti oblici/vrste seksualnih veza, koje se javljaju u postkataklizmičnom okruženju, u odnosu na dva tipa zajednica/društava koja nastaju nakon kraja sveta. Ti filmovi pokazuju koliko je ideja o nagonskoj, prirodnoj, biološkoj seksualnosti raširena u popularnoj imaginaciji – seks je u postapokalipsi predstavljen kao pokretačka sila, na isti način kao što je to i glad.

La importancia de la sífilis en el universo masculino: un estudio sobre las representaciones sociales

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Sandra Duarte Nobre MAUCH

2012-08-01

Full Text Available A pesquisa apresentada neste artigo se propôs a investigar o significado da sífilis entre homens, apoiando-se na Teoria das Representações Sociais. Foram entrevistados 265 homens, com os quais se utilizou da técnica de evocação livre, tendo como o termo indutor “a sífilis”. Para a análise dos dados foram efetuadas estatísticas descritivas, análise lexical do discurso com apoio do software ALCESTE, análise da estrutura das representações sociais com apoio do software EVOC e teste de centralidade das palavras principais. A análise lexical identificou duas grandes matrizes de sentido: “a doença” e “a doença sexual”. A primeira reúne o discurso de homens mais jovens e mais escolarizados, centrado na prevenção e tratamento da doença. A segunda matriz reúne o discurso de homens adultos e menos escolarizados, e revela um discurso permeado de crendices e superstições, ligando a doença a práticas sexuais consideradas impuras. Na estrutura das representações sociais a sífilis aparece associada aos elementos DST, sexual, tratamento, preservativo, prevenção, sangue e perigo. Observou-se, nestas epresentaçõessociais, um amálgama de ideias, crenças e valores que fazem coexistir, de um lado, elementos mais recentes da história da sífilis, como tratamento, prevenção e preservativos e, de outro, elementos mais arcaicos, como sangue e perigo.

La importancia estratégica de los Presupuestos Participativos en los gobiernos locales de Córdoba, Gualeguaychú, Paysandú y Montevideo

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Mariano Suárez

2016-07-01

Full Text Available Se analiza la importancia estratégica de los presupuestos participativos en cuatro gobiernos locales de Argentina y Uruguay: Córdoba, Gualeguaychú, Paysandú y Montevideo. El análisis se focaliza en dos elementos, la posición del Presupuesto Participativo dentro de la estructura de gobierno, analizado en función del organigrama del mismo, y el alcance de la política en términos de la capacidad de la herramienta para generar transformaciones en el territorio. En el artículo se argumenta que las experiencias analizadas tienen una impronta más cercana a la función de movilización ciudadana que de gestión pública. Con relación a la posición de los Presupuestos Participativos, se observa que están más cerca de la estructura participativa que de las áreas de planificación y presupuesto, con la excepción de Montevideo, donde la condición de asesoría lo ubica en un lugar con mayor capacidad de transversalización.

Sistemas de Costes: Importancia, Viabilidad y Utilidad en la Concepción de los Agentes Públicos del Estado de Paraná (Brasil

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Luciane Maria Gonçalves Franco

2013-06-01

Full Text Available Este estudio tiene por objetivo conocer el nivel de entendimiento y de adopción en relación a los sistemas de costes por parte de los municipios de Paraná. Se trata de estudio descriptivo, con abordaje cualitativo. La colecta de datos tuvo lugar mediante aplicación de un cuestionario en 67 municipios del Estado de Paraná. Se ejecutó un análisis descriptivo y se aplicó el test estadístico de correlación del coeficiente de Spearman para fines de atender al objetivo. De entre los resultados del estudio, se destaca: la insipiencia del conocimiento acerca de la importancia, viabilidad y utilidad de un sistema de costes; embasado por limitaciones en el conocimiento por parte de los agentes públicos, sobretodo, en los tópicos que tratan de viabilidad presupuestaria y financiera de la adopción de sistemas de costes; ambiente para el sistema de costes, sistemas de costes implantados y sistemas operacionales; aunque las respuestas obtenidas en las proposiciones sobre información y control de costes hayan sido significativamente coherentes.

Importancia, contribución y estabilidad de antioxidantes en frutos y productos de tomate (Solanum lycopersicum L.

Directory of Open Access Journals (Sweden)

M. L. Luna-Guevara

2014-01-01

Full Text Available Los antioxidantes (AA son compuestos capaces de inhibir o retardar la oxidación, mediante la “captación” de radicales libres; también estabilizan hidroperóxidos o inactivan el oxígeno singulete. Los frutos de tomate han sido considerados una fuente importante de AA “nutricionales” (vitaminas A, C y E y AA “fitoquímicos no nutritivos” (licopeno, flavonoides, flavonas y compuestos fenólicos totales, cuyo consumo está relacionado con su potencial antimutagénico y propiedades anticancerígenas. Las condiciones ambientales durante el cultivo como: intensidad de luz, pH del suelo, frecuencia de riego, tipo de fertilización, pueden afectar la composición química del fruto. Asimismo, durante la maduración del tomate, se inducen varios cambios metabólicos relacionados con la biosíntesis de compuestos, incluyendo el licopeno y otros carotenoides. También se ha demostrado que ciertas operaciones de manejo post cosecha y procesamiento del tomate (cortado, empacado y almacenado pueden alterar la concentración de micronutrientes (vitaminas y minerales y de compuestos AA. De acuerdo con los antecedentes mencionados, en la presente revisión se abordará la importancia de conocer los factores pre y post cosecha que afectan el contenido de AA en el tomate; asimismo, se destacará la estabilidad de los compuestos fitoquímicos contenidos en frutos sometidos a diferentes condiciones de procesamiento. Esta información resulta útil para la industria de los alimentos, además de fomentar el consumo de compuestos funcionales.

23Na and 35/37Cl as NMR probes of growth and shape of sodium taurodeoxycholate micellar aggregates in the presence of NaCl.

Science.gov (United States)

Asaro, Fioretta; Feruglio, Luigi; Galantini, Luciano; Nardelli, Alessia

2013-02-15

The growth of the aggregates of the dihydroxylated bile salt sodium taurodeoxycholate (NaTDC) upon NaCl addition and the involvement of the counterion were investigated by NMR spectroscopy of monoatomic ionic species. (23)Na T(1) values from 0.015, 0.100, and 0.200 mol kg(-1) NaTDC solutions in D(2)O, at variable NaCl content, proved to be sensitive to the transition from primary to secondary aggregates, which occurs in the former sample, and to intermicellar interaction. Some (79)Br NMR measurements were performed on a 0.100 mol kg(-1) NaTDC sample added by NaBr in place of NaCl for comparison purposes. The (23)Na, (35)Cl, and (37)Cl double quantum filtered (DQF) patterns, from the 0.100 mol kg(-1) NaTDC sample, and (23)Na ones also from the 0.200 mol kg(-1) NaTDC one, in the presence of 0.750 mol kg(-1) NaCl, are a clear manifestation of motional anisotropy. Moreover, the DQF spectra of (23)Na and (37)Cl, which possess close quadrupole moments, display a striking similarity. The DQF lineshapes were simulated exploiting the Scilab environment to obtain an estimate of the residual quadrupole splitting magnitude. These results support the description of NaTDC micelles as cylindrical aggregates, strongly interacting at high ionic strengths, and capable of association with added electrolytes. Copyright © 2012 Elsevier Inc. All rights reserved.

Robust high pressure stability and negative thermal expansion in sodium-rich antiperovskites Na3OBr and Na4OI2

International Nuclear Information System (INIS)

Wang, Yonggang; Wen, Ting; Park, Changyong; Kenney-Benson, Curtis; Pravica, Michael; Zhao, Yusheng; Yang, Wenge

2016-01-01

The structure stability under high pressure and thermal expansion behavior of Na 3 OBr and Na 4 OI 2 , two prototypes of alkali-metal-rich antiperovskites, were investigated by in situ synchrotron X-ray diffraction techniques under high pressure and low temperature. Both are soft materials with bulk modulus of 58.6 GPa and 52.0 GPa for Na 3 OBr and Na 4 OI 2 , respectively. The cubic Na 3 OBr structure and tetragonal Na 4 OI 2 with intergrowth K 2 NiF 4 structure are stable under high pressure up to 23 GPa. Although being a characteristic layered structure, Na 4 OI 2 exhibits nearly isotropic compressibility. Negative thermal expansion was observed at low temperature range (20–80 K) in both transition-metal-free antiperovskites for the first time. The robust high pressure structure stability was examined and confirmed by first-principles calculations among various possible polymorphisms qualitatively. The results provide in-depth understanding of the negative thermal expansion and robust crystal structure stability of these antiperovskite systems and their potential applications

Thermoluminescence and F centers of manganese doped NaCl and NaCl-CKl crystals exposed to gamma radiation

International Nuclear Information System (INIS)

Somera, L.; Cruz Z, E.; Roman L, J.; Hernandez A, J. M.; Murrieta S, H.

2015-10-01

Alkali halides crystals doped with rare earths or transition metals have been widely studied due to the luminescence properties. In particular, NaCl and KCl single crystals present thermally stimulated luminescence (Tl) after gamma irradiation. The NaCl and the NaCl KCl mixed crystal doped with manganese (MnCl 2 ) impurity were grown by using the Czochralski method. The emission characteristic of Mn 2+ was observed at 543 nm. The crystals were exposed between 0.02 and 10 kGy gamma dose from 60 Co irradiator. Optical absorption at room temperature shows the peaked band at 452 nm corresponding to the manganese impurity. The F bands, was ascribed to the electron trapped in the anion vacancy in the lattice, were obtained at 452 nm and 455 nm belonging to NaCl:Mn and NaCl KCl:Mn, respectively. The F band increases as the doses increase and it was bleaching by the UV light at 470 nm. The glow curves of the samples show the first glow peak between 92-103 degrees C, while the second main peak was observed at 183 degrees C for the undoped NaCl and at 148 and 165 degrees C for the NaCl:Mn and NaCl-KCl:Mn, respectively. The main peak was slowly bleaching when the irradiated sample was illuminated with F (470 nm) light. Optical bleaching confirms that the F center has an important participation in the thermoluminescent response. The glow curves structure from the thermal bleaching suggests the participation of different kind of traps. Also, the kinetics parameters such as activation energy (E), frequency factor (s) and the kinetic order (b) were investigated. (Author)

Thermoluminescence and F centers of manganese doped NaCl and NaCl-CKl crystals exposed to gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Somera, L.; Cruz Z, E.; Roman L, J. [UNAM, Instituto de Ciencias Nucleares, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Hernandez A, J. M.; Murrieta S, H., E-mail: ecruz@nucleares.unam.mx [UNAM, Instituto de Fisica, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

2015-10-15

Alkali halides crystals doped with rare earths or transition metals have been widely studied due to the luminescence properties. In particular, NaCl and KCl single crystals present thermally stimulated luminescence (Tl) after gamma irradiation. The NaCl and the NaCl KCl mixed crystal doped with manganese (MnCl{sub 2}) impurity were grown by using the Czochralski method. The emission characteristic of Mn{sup 2+} was observed at 543 nm. The crystals were exposed between 0.02 and 10 kGy gamma dose from {sup 60}Co irradiator. Optical absorption at room temperature shows the peaked band at 452 nm corresponding to the manganese impurity. The F bands, was ascribed to the electron trapped in the anion vacancy in the lattice, were obtained at 452 nm and 455 nm belonging to NaCl:Mn and NaCl KCl:Mn, respectively. The F band increases as the doses increase and it was bleaching by the UV light at 470 nm. The glow curves of the samples show the first glow peak between 92-103 degrees C, while the second main peak was observed at 183 degrees C for the undoped NaCl and at 148 and 165 degrees C for the NaCl:Mn and NaCl-KCl:Mn, respectively. The main peak was slowly bleaching when the irradiated sample was illuminated with F (470 nm) light. Optical bleaching confirms that the F center has an important participation in the thermoluminescent response. The glow curves structure from the thermal bleaching suggests the participation of different kind of traps. Also, the kinetics parameters such as activation energy (E), frequency factor (s) and the kinetic order (b) were investigated. (Author)

Occlusion of /sup 22/Na+ and /sup 86/Rb+ in membrane-bound and soluble protomeric alpha beta-units of Na,K-ATPase

Energy Technology Data Exchange (ETDEWEB)

Vilsen, B.; Andersen, J.P.; Petersen, J.; Jorgensen, P.L.

1987-08-05

In this work, we examined occlusion of /sup 22/Na+ and /sup 86/Rb+ in membranous and detergent-solubilized Na,K-ATPase from outer renal medulla. Optimum conditions for occlusion of /sup 22/Na+ were provided by formation of the phosphorylated complex from the beta,gamma-bidentate complex of chromium (III) with ATP (CrATP). Release of occluded cations occurred at equally slow rates in soluble and membrane-bound Na,K-ATPase. Values of /sup 22/Na+ occlusion as high as 11 nmol/mg of protein were measured, corresponding to 1.8-2.7 mol of Na+/mol of phosphorylated Na,K-ATPase as determined by /sup 32/P incorporation from (gamma-/sup 32/P)CrATP. Maximum capacity for phosphorylation from (gamma-/sup 32/P)CrATP was 6 nmol/mg of protein and equal to capacities for binding of (48V)vanadate and (/sup 3/H)ouabain. The stoichiometry for occlusion of Rb+ was close to 2 Rb+ ions/phosphorylation site. In an analytical ultracentrifuge, the soluble Na+- or Rb+-occluded complexes showed sedimentation velocities (S20,w = 6.8-7.4) consistent with monomeric alpha beta-units. The data show that soluble monomeric alpha beta-units of Na,K-ATPase can occlude Rb+ or Na+ with the same stoichiometry as the membrane-bound enzyme. The structural basis for occlusion of cations in Na,K-ATPase is suggested to be the formation of a cavity inside a monomeric alpha beta-unit constituting the minimum protein unit required for active Na,K-transport.

Europlanet NA2 Science Networking

Science.gov (United States)

Harri, Ari-Matti; Szego, Karoly; Genzer, Maria; Schmidt, Walter; Krupp, Norbert; Lammer, Helmut; Kallio, Esa; Haukka, Harri

2013-04-01

Europlanet RI / NA2 Science Networking [1] focused on determining the major goals of current and future European planetary science, relating them to the Research Infrastructure that the Europlanet RI project [2] developed, and placing them in a more global context. NA2 also enhanced the ability of European planetary scientists to participate on the global scene with their own agenda-setting projects and ideas. The Networking Activity NA2 included five working groups, aimed at identifying key science issues and producing reference books on major science themes that will bridge the gap between the results of present and past missions and the scientific preparation of the future ones. Within the Europlanet RI project (2009-2012) the NA2 and NA2-WGs organized thematic workshops, an expert exchange program and training groups to improve the scientific impact of this Infrastructure. The principal tasks addressed by NA2 were: • Science activities in support to the optimal use of data from past and present space missions, involving the broad planetary science community beyond the "space club" • Science activities in support to the preparation of future planetary missions: Earth-based preparatory observations, laboratory studies, R&D on advanced instrumentation and exploration technologies for the future, theory and modeling etc. • Develop scientific activities, joint publications, dedicated meetings, tools and services, education activities, engaging the public and industries • Update science themes and addressing the two main scientific objectives • Prepare and support workshops of the International Space Science Institute (ISSI) in Bern and • Support Trans National Activities (TNAs), Joined Research Activities (JRAs) and the Integrated and Distributed Information Service (IDIS) of the Europlanet project These tasks were achieved by WG workshops organized by the NA2 working groups, by ISSI workshops and by an Expert Exchange Program. There were 17 official WG

NA61/SHINE ion program

CERN Document Server

Mackowiak, Maja

2010-01-01

The Super Proton Synchrotron (SPS) at CERN covers one of the most interesting regions of the phase diagram (T - \\mu_{B}) of strongly interacting matter. The study of central Pb+Pb collisions by NA49 indicate that the threshold for deconfinement is reached already at the low SPS energies. Theoretical considerations predict a critical point of strongly interacting matter at energies accessible at the SPS. The NA61/SHINE experiment, a successor of the NA49 project, will study hadron production in p+p, p+A, h+A, and A+A reactions at various energies. The broad physics program includes the investigation of the properties of strongly interacting matter, as well as precision measurements of hadron spectra for the T2K neutrino experiment and for the Pierre Auger Observatory and KASCADE cosmic-ray projects. The main physics goals of the NA61/SHINE ion program are to study the properties of the onset of deconfinement at low SPS energies and to find signatures of the critical point of strongly interacting matter. To ach...

Armas na escola: que fazer?

Directory of Open Access Journals (Sweden)

Raymundo de Lima

2010-09-01

Full Text Available

Um aluno portava um revólver na sala de aula de uma escola de Maringá (O Diário, 30/07/2010. Ele pegou arma do pai, sem que este soubesse, para se proteger de garotos que o intimidavam. Trata-se de um caso isolado ou é hora de a escola tomar medidas preventivas? Semanas antes, tiros foram disparados dentro de uma faculdade da mesma cidade. O autor dos disparos está preso, e a faculdade tenta apagar as marcas com publicidade positiva na Tv. Em Campo Mourão, cidade a cerca de uma hora de Maringá, duas meninas foram mortas e enterradas na escola.

Isotope separation of 22Na and 24Na with using light induced drift effect

International Nuclear Information System (INIS)

Hradecny, C.; Tethal, T.; Ermolaev, I.M.; Zemlyanoj, S.G.; Zuzaan, P.

1993-01-01

The LIDIS (Light Drift Isotope Separation) separator without a gas flow is discussed. It is shown, that atomization degree of the separated isotopes limited real separation coefficient. The better buffer gas purification allowed to increase the experimental separation factor of 22 Na and 24 Na isotopes up to 25. The new experimental set up allow to increase the separation efficiency up to 50%. 12 refs.; 5 figs

MOBILNO POSLOVANJE NA PRIMERU UPORABE MICROSOFT DYNAMICS CRM

OpenAIRE

Duh, Tamara

2016-01-01

Hitro razvijajoči se svet nas spodbuja k hitremu reagiranju na novosti, ki se pojavljajo na trgu. Prav zaradi tega je danes zelo pomembno upravljati z mobilnimi napravami, da se lahko hitro in brez težav soočimo z morebitnimi težavami oz. zagatami. Prav iz tega razloga je mobilno poslovanje ena izmed inovativnih rešitev, ki ljudem omogoča seznanjenost z informacijami na vsakem koraku in omogoča hiter odziv na spremembe. Prav ta rešitev omogoča podjetjem, da so konkurenčna in hkrati lahko hitr...

Usando a antimatéria na medicina moderna

OpenAIRE

Machado,A.C.B.; Pleitez,V.; Tijero,M.C.

2006-01-01

Neste artigo, fazemos uma breve exposição de como um dos conceitos fundamentais da física moderna, a existência de antimatéria, tem aplicação na medicina, na chamada tomografia por emissão de pósitrons (PET na sigla em inglês). Ela consiste na produção de imagens tomográficas digitais do organismo que são obtidas pela detecção da radiação produzida na aniquilação do pósitron com o elétron.

43. Calmodulin regulating calcium sensitivity of Na channels

Directory of Open Access Journals (Sweden)

R. Vegiraju

2016-07-01

Full Text Available By extrapolating information from existing research and observing previous assumptions regarding the structure of the Na Channel, this experiment was conducted under the hypothesis that the Na Channel is in part regulated by the calmodulin protein, as a result proving calcium sensitivity of the Na Channel. Furthermore, we assume that there is a one to one stoichiometry between the Na Channel and the Calmodulin. There has been extensive research into the functionality and structure of sodium ion channels (Na channels, as several diseases are associated with the lack of regulation of sodium ions, that is caused by the disfunction of these Na channels. However, one highly controversial matter in the field is the importance of the protein calmodulin (CaM and calcium in Na channel function. Calmodulin is a protein that is well known for its role as a calcium binding messenger protein, and that association is believed to play an indirect role in regulating the Na channel through the Na channel’s supposed calcium sensitivity. While there are proponents for both sides, there has been relatively little research that provides strong evidence for either case. In this experiment, the effect of calmodulin on NaV 1.5 is tested by preparing a set of cardiac cells (of the human specie with the NaV 1.5 C-Termini and CaM protein, which were then to be placed in solutions with varying concentrations of calcium. We took special care to test multiple concentrations of calcium, as previous studies have tested very low concentrations, with Manu Ben-Johny’s team from the John Hopkins laboratory in particular testing up to a meager 50 micromolar, despite producing a well-respected paper (By comparison, the average Na channel can naturally sustain a concentration of almost 1-2 millimolar and on some occasions, reaching even higher concentrations. After using light scattering and observing the signals given off by the calcium interacting with these Nav1.5/Ca

Importancia de la semiología del dolor en el diagnóstico de un proceso inflamatorio pulpar

Directory of Open Access Journals (Sweden)

Andrés 0 Pérez Ruiz

2011-09-01

Full Text Available El dolor es un síntoma de extraordinaria importancia en la práctica estomatológica y particularmente en lo concerniente a las alteraciones de la pulpa dentaria. Con el objetivo de profundizar en el conocimiento de las fases por las que atraviesa un proceso inflamatorio pulpar, que permiten predecir sus manifestaciones dolorosas, se realizó una revisión bibliográfica sobre el tema con un enfoque multidisciplinario y básico-clínico. Se utilizó el método documental para el análisis y tratamiento de la información ofrecida por las fuentes teóricas. El sitio en Internet Google fue empleado como fundamental motor de búsqueda y Lilacs, Hinari, Medline y PubMed fueron las bases de datos más revisadas. La clasificación del estado de inflamación pulpar, que atiende a eventos histopatológicos que no se pueden visualizar, resulta más difícil. Se podría lograr mayor precisión en un diagnóstico basado en el curso que sigue el dolor, de acuerdo a la magnitud del compromiso inflamatorio y apoyado en la rica semiología que se puede obtener si se sigue la trayectoria de las variables del estímulo nociceptivo. El incremento y profundización de los conocimientos en este campo contribuiyó significativamente a un mejor diagnóstico y tratamiento de los procesos inflamatorios pulpares.

In vivo PTH provokes apical NHE3 and NaPi2 redistribution and Na-K-ATPase inhibition

DEFF Research Database (Denmark)

Zhang, Y; Norian, J M; Magyar, C E

1999-01-01

and to determine whether the same cellular signals drive the changes in apical and basolateral transporters. PTH-(1-34) (20 U), which couples to adenylate cyclase (AC), phospholipase C (PLC), and phospholipase A2 (PLA2), or [Nle8,18,Tyr34]PTH-(3-34) (10 U), which couples to PLC and PLA2 but not AC, were given....../diuresis and NHE3 and NaPi2 internalization, and that Na-K-ATPase inhibition is not secondary to depressed apical Na+ transport....

Aspectos valorizados por porfissionais de enfermagem na higiene pessoal e na higiene corporal do paciente

Directory of Open Access Journals (Sweden)

Elóide André Oliveira

2003-10-01

Full Text Available Survey descritivo, com o qual se objetivou identificar que aspectos da higiene corporal são valorizados pelos componentes da equipe de enfermagem, na higiene corporal pessoal e na higiene corporal do paciente. A pesquisa foi desenvolvida em oito instituições públicas de saúde e a amostra foi composta por 126 profissionais de enfermagem, correspondendo a 12,8% do total de 986 componentes das equipes de enfermagem destas instituições. Na higiene corporal pessoal, chamou a atenção o fato de que os cuidados com as unhas e com os cabelos tenham suplantado, no número de citações dos profissionais de enfermagem, aspectos básicos como o cuidado com as mãos. Na higiene corporal do paciente, o banho foi o aspecto considerado mais importante pelas três categorias profissionais; a higiene oral, pelas(os enfermeiras(os e auxiliares de enfermagem; e as unhas, pelas(os enfermeiras(os e técnicas(os de enfermagem.

Modulation of contraction by intracellular Na+ via Na(+)-Ca2+ exchange in single shark (Squalus acanthias) ventricular myocytes.

Science.gov (United States)

Näbauer, M; Morad, M

1992-01-01

1. The effect of direct alteration of intracellular Na+ concentration on contractile properties of whole-cell clamped shark ventricular myocytes was studied using an array of 256 photodiodes to monitor the length of the isolated myocytes. 2. In myocytes dialysed with Na(+)-free solution, the voltage dependence of Ca2+ current (ICa) and contraction were similar and bell shaped. Contractions activated at all voltages were completely suppressed by nifedipine (5 microM), and failed to show significant tonic components, suggesting dependence of the contraction on Ca2+ influx through the L-type Ca2+ channel. 3. In myocytes dialysed with 60 mM Na+, a ICa-dependent and a ICa-independent component of contraction could be identified. The Ca2+ current-dependent component was prominent in voltages between -30 to +10 mV. The ICa-independent contractions were maintained for the duration of depolarization, increased with increasing depolarization between +10 to +100 mV, and were insensitive to nifedipine. 4. In such myocytes, repolarization produced slowly decaying inward tail currents closely related to the time course of relaxation and the degree of shortening prior to repolarization. 5. With 60 mM Na+ in the pipette solution, positive clamp potentials activated decaying outward currents which correlated to the size of contraction. These outward currents appeared to be generated by the Na(+)-Ca(2+)-exchanger since they depended on the presence of intracellular Na+, and were neither suppressed by nifedipine nor by K+ channel blockers. 6. The results suggest that in shark (Squalus acanthias) ventricular myocytes, which lack functionally relevant Ca2+ release pools, both Ca2+ channel and the Na(+)-Ca2+ exchanger deliver sufficient Ca2+ to activate contraction, though the effectiveness of the latter mechanism was highly dependent on the [Na+]i. PMID:1338467

LA IMPORTANCIA DEL CUERPO EN LA NOCIÓN DE PERSONA ENTRE MAYAS ACTUALES DE OXCHUC, CHAMULA Y CHENALHÓ, CHIAPAS

Directory of Open Access Journals (Sweden)

Jaime Tomás Page Pliego

2014-12-01

Full Text Available Suele asumirse que la noción de persona es igual entre los pueblos de tsotsiles y tesltales de los Altos de Chiapas. Sin embargo, su configuración varía sustancialmente, sin perder la base que los une. Este trabajo trata sobre las diferencias y similitudes que se presentan en el concepto denominado complejo persona en tres municipios: Oxchuc —de habla tseltal—, Chamula y Chenalhó —de habla tsotsil—, y en forma destacada sobre la importancia del cuerpo en dicho concepto. Asimismo, se abordan las variaciones que se han suscitado en torno a esa noción a partir de 1940, bajo la incidencia de la escalada proselitista cristiana. THE IMPORTANCE OF THE BODY WITHIN THE COMPLEX OF THE NOTION OF PERSONHOOD AMONG CONTEMPORARY MAYANS FROM OXCHUC, CHAMULA AND CHENALHÓ IN CHIAPAS STATE There is a tendency to assume that the Tsotsil and Tseltal communities in the Chiapas Highlands (Altos de Chiapas share the same notion of personhood. However, the way this notion is constructed does vary substantially without losing a common foundation. This piece of research deals with the similarities and differences present in the concept of personhood complex in three different municipalities: Oxchuc —a tseltal-speaking community—, Chamula and Chenalhó —tsotsil-speaking communities—, and emphasizes the importance of the body in this concept. It also addresses the permutations that have emerged around this notion since 1940, under the escalating influence of Christian proselytism.

KANDUNGAN NATRIUM (Na DAN GARAM (NaCl DALAM IKAN ASIN KERING MENTAH DAN GORENG DI PASAR ANYAR BOGOR

Directory of Open Access Journals (Sweden)

Heru Yuniati

2012-11-01

Full Text Available Telah dilakukan penelitian untuk mengetahui kandungan natrium (Na dan garam (NaCl dalam 10 jenis ikan asin kering yang beredar di Pasar Anyar Bogor. Analisis natrium dilakukan terhadap ikan asin mentah, setelah dicuci, dan setelah digoreng dengan menggunakan flamefometer. Analisis garam dilakukan dengan titrasi argentometri terhadap ikan asin mentah. Hasil analisis menunjukkan, kandungan Na dan garam dalam ikan asin sangat beragam besarnya berturut-turut berkisar antara 0,3-8,1% dan 5,7-21,2%. Ikan asin yang mempunyai kadar Na dan garam tinggi adalah ikan sepat, peda putih dan gabus. Jumlah air dalam ikan asin juga bervariasi, berkisar antara 10,3-46,8%. pencucian dan penggorengan dapat menurunkan kadar garam ataupun natrium sebesar 37,4%.

Aprendizagem como/na prática

Directory of Open Access Journals (Sweden)

Jean Lave

2015-12-01

Full Text Available ResumoEste artigo considera como o estudo da cultura e da aprendizagem pode ser de particular relevância para o campo da antropologia sociocultural em geral. O termo mais importante na expressão “cultura & aprendizagem” talvez seja o logograma “&” – ou seja, coloca-se a questão sobre o que conecta cultura e aprendizagem, perguntando-se como esses termos estão relacionados. Como devemos compreender cultura e aprendizagem como instâncias produtoras delas próprias, e uma da outra, na prática? Recalibrando em termos relacionais, podemos dizer que não é possível abordar a “aprendizagem” ou “cultura e aprendizagem” sem o seu emaranhamento na vida político-econômica, nas lutas e disputas históricas, em suas coerências e incoerências, e na produção relacional e histórica da vida cotidiana. Através das lentes da teoria da prática social, os estudos etnográficos sobre aprendizagem na prática oferecem diferentes entendimentos sobre como certa vida e certas disputas e incoerências são produzidas.

Metodologija analize stroškov in koristi za investicije v prometno infrastrukturo na osnovi Poročila vplivov na okolje

OpenAIRE

Podvornik, Nina

2016-01-01

Povečane potrebe po prometnem omrežju vodijo k dodatnim prometnim investicijam, ki so ne glede na njihov obseg, postavitev v prostor ter učinkovitost pomemben dejavnik gospodarskega razvoja. Investicije v prometno infrastrukturo lahko na sam razvoj vplivajo pozitivno (dvig gospodarske rasti, kakovost življenja, dostopnost idr.) in tudi negativno (različni vplivi na okolje). Ker so prometne investicije zelo obsežne, je vsestranska ocena le-teh ključnega pomena pri samem prometnem načrtovanju v...

Agmag Igbo dka Ngwar n'kwalite Ezi Nchekwa na Nkwsiike haobodo

African Journals Online (AJOL)

Ka Najira nwerechara onwe ya n'af 1960, olileanya tt mamala ya b na ihe ga-adz mma. Mana ka oge na-aga, a chptara na ihe na-akawanye nj. Usoro chch d iche iche daptara. Nd am na nd nkt achala mana nd gara n'ihu na-akawanye nj. O bu ihe doro anya na chch ha b nke nchgbu na fnfju akpa. N'agbanyegh na ...

Regulation of Epithelial Sodium Transport via Epithelial Na+ Channel

Science.gov (United States)

Marunaka, Yoshinori; Niisato, Naomi; Taruno, Akiyuki; Ohta, Mariko; Miyazaki, Hiroaki; Hosogi, Shigekuni; Nakajima, Ken-ichi; Kusuzaki, Katsuyuki; Ashihara, Eishi; Nishio, Kyosuke; Iwasaki, Yoshinobu; Nakahari, Takashi; Kubota, Takahiro

2011-01-01

Renal epithelial Na+ transport plays an important role in homeostasis of our body fluid content and blood pressure. Further, the Na+ transport in alveolar epithelial cells essentially controls the amount of alveolar fluid that should be kept at an appropriate level for normal gas exchange. The epithelial Na+ transport is generally mediated through two steps: (1) the entry step of Na+ via epithelial Na+ channel (ENaC) at the apical membrane and (2) the extrusion step of Na+ via the Na+, K+-ATPase at the basolateral membrane. In general, the Na+ entry via ENaC is the rate-limiting step. Therefore, the regulation of ENaC plays an essential role in control of blood pressure and normal gas exchange. In this paper, we discuss two major factors in ENaC regulation: (1) activity of individual ENaC and (2) number of ENaC located at the apical membrane. PMID:22028593

Na+,K+ pumpen vedbliver at overraske

DEFF Research Database (Denmark)

Vilsen, Bente

2008-01-01

This article provides an overview of news about the Na+,K+ pump, an indispensable enzyme whose protein structure has been described in a recent article in Nature, 50 years after its discovery. In combination with mutational analysis, the structure reveals the binding pocket for the K+ ions...... and the regulation of Na+ transport by a strategically located C-terminus of the protein. Focus is also on the pathophysiology of two neurological disorders, familial hemiplegic migraine and rapid-onset dystonia-parkinsonism, recently shown to be caused by mutations in the Na+,K+-ATPase. Udgivelsesdato: may 19...

Risbjerg: Historisk stemmeskred med NA

DEFF Research Database (Denmark)

Thomsen, Søren Risbjerg

2007-01-01

ANALYSE: NA flytter 12,3 pct. af stemmerne i majs meningsmålinger - historisk mange vælgere på en måned, skriver professor Risbjerg. Udgivelsesdato: 3. juni 2007......ANALYSE: NA flytter 12,3 pct. af stemmerne i majs meningsmålinger - historisk mange vælgere på en måned, skriver professor Risbjerg. Udgivelsesdato: 3. juni 2007...

Dissolution of targets for the production of Mo-99: Part 1. Influence of NaOH concentration and the addition of NaNO{sub 3} and NaNO{sub 2} on the dissolution time

Energy Technology Data Exchange (ETDEWEB)

Camilo, Ruth L.; Araujo, Izilda da C.; Mindrisz, Ana C.; Forbicini, Christina A.L.G. de O., E-mail: rcamilo@ipen.br, E-mail: icaraujo@ipen.br, E-mail: acmindri@ipen.br, E-mail: cforbici@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN/SP), Sao Paulo, SP (Brazil)

2011-07-01

Faced with global crisis in the production of radioisotope {sup 99}Mo, which product of decay, {sup 99}mTc, is the tracer element most often used in nuclear medicine and accounts for about 80% of all diagnostic procedures in vivo, since September 2008 Brazil is developing the project called Brazilian Multipurpose Reactor (RMB). Within the Brazilian Nuclear Program (PNB) the construction of the RMB, is seen as a long term solution to meet all domestic demand relative to the supply of radioisotopes and radiopharmaceuticals. In the process to be studied to obtain {sup 99}Mo from irradiated UA1{sub x}-A1 LEU targets employing alkaline dissolution, processing time should be minimized, considering the short half life of {sup 99}Mo and {sup 99}mTc, about 66 h and 6 h, respectively. That makes dissolution time a significant factor in the development of the process. This paper presents the results of alkaline dissolution of scraps of Al, used to simulate the dissolution process of UA1{sub x}-A1 targets. Al corresponds to about 79% of the total weight of the UA1{sub x}-A1 target. The effect of NaOH concentration on dissolution time for the interval of 1 to 3.5 mol.L-1 was studied, keeping the molar ratio in 1Al:2.16NaOH and the initial temperature of 88 degree C. The influence of reagent composition over dissolution time was studied using three different solutions: a) 3 mol.L{sup -1} NaOH, b) 3 mol.L{sup -1} NaOH/NaNO{sub 3} and c) 3 mol.L{sup -1} NaOH/NaNO{sub 2}, keeping the same molar ratio and temperature. The results showed that the dissolution time decreases with increasing NaOH concentration and the addition of NaNO{sub 3} or NaNO{sub 2} in the NaOH solution reduces both dissolution time and volume of gases released. (author)

Crystal Structure of Na3MoCl6

Directory of Open Access Journals (Sweden)

Martin Beran

2011-07-01

Full Text Available The ternary chloride Na3MoCl6 is obtained as red crystals from a disproportionation reaction of molybdenum dichloride, {Mo6}Cl12, in an acidic NaCl/AlCl3 melt at 350 °C. The crystal structure (trigonal, P-31c, a = 687.1(1, c = 1225.3(2 pm, Z = 2, V = 501,0(1 106 pm3 is that of Na3CrCl6: within a hexagonal closest-packing of chloride ions two thirds of the octahedral voids are filled between the AB double layers with Na+/Mo3+, and between the BA layers with Na+.

Diffusion of calcium in pure and doped NaCl; Diffusion du calcium dans NaCl pur et dope

Energy Technology Data Exchange (ETDEWEB)

Slifkin, L; Brebec, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

We have determined, by diffusion experiments of Ca in pure and doped NaCl, the activation energy for the calcium jumps and the binding energy between calcium ion and vacancy. (authors) [French] Nous avons determine, par des mesures de diffusion du Ca dans NaCl pur et NaCl dope avec CaCl{sub 2}, l'energie d'activation relative aux sauts du calcium et l'energie de liaison lacune-calcium. (auteurs)

Wizerunek ateisty i jego miejsce na konfesyjnej mapie świata na Śląsku Cieszyńskim

Directory of Open Access Journals (Sweden)

Zbigniew Greń

2017-12-01

Full Text Available The image of the atheist and his place on the confessional map of the world in Cieszyn Silesia The aim of this article is to create an image of the atheist based on historical and contemporary sources. The history of the concept of the atheist is described on the basis of the regional press, the contemporary picture of the concept – on the basis of the results of a questionnaire and discussions on religious topics on regional websites. The analysis showed that the concept of the atheist is treated as a term equivalent to the terms of members of different churches. The research shows not only the image of the atheist, but also its place in the system of perception of religious differences.   Wizerunek ateisty i jego miejsce na konfesyjnej mapie świata na Śląsku Cieszyńskim Celem niniejszego artykułu jest stworzenie obrazu ateisty na podstawie źródeł historycznych i współczesnych. Historia pojęcia ateisty została opisana na podstawie prasy regionalnej, współczesny obraz – na podstawie wyników ankiet i dyskusji na tematy religijne na regionalnych stronach internetowych. Analiza wykazała, że pojęcie ateisty jest traktowane jako pojęcie równorzędne z określeniami członków różnych Kościołów. W wyniku badań przedstawiono nie tylko wizerunek ateisty, lecz także jego miejsce w systemie postrzegania różnic wyznaniowych.

Mabadiliko Ya Kifonolojia Na Kimofolojia Wakati Wa Utohozi Wa ...

African Journals Online (AJOL)

Mwingiliano wa lugha ya Kiswahili na Kiarabu una historia ndefu kidogo. Inasemekana Waarabu walianza muwasala na 'Waswahili' tangu karne ya kwanza (BK) (Polome 1967:9). Kutokana na muwasala huo wa muda mrefu, lugha hizi mbili (Kiarabu na Kiswahili) zimeathiriana sana. Lakini kuna maoni kwamba Kiarabu ...

Aqueous partial molar heat capacities and volumes for NaReO4 and NaTcO4

International Nuclear Information System (INIS)

Lemire, R.J.; Saluja, P.P.S.; Campbell, A.B.

1989-01-01

As part of the Canadian Nuclear Fuel Waste Management Program, data are required to model the equilibrium thermodynamic behavior of key radionuclides at temperatures above 25 degree C. A flow microcalorimeter/densimeter system has been commissioned to measure heat capacities and densities of solutions containing radioactive species. Measurements for solutions of aqueous NaReO 4 (a common analogue for NaTcO 4 ) were made at seven temperatures (15 to 100 degree C) over the concentration range 0.05 to 0.2 mol·kg -1 . Subsequently, measurements were made for NaTcO 4 solutions under similar conditions. The heat capacity and density data are analyzed using Pitzer's ion-interaction model, and values of the NaReO 4 partial molar heat capacities are compared to literature values based on integral heats of solution. The agreement between the two sets of NaReO 4 data is good below 75 degree C, but only fair at the higher temperatures. Values of the partial molar volumes have also been derived. The uncertainties introduced by using thermodynamic data for ReO 4 - , in the absence of data for TcO 4 - , are discussed

Effects of dietary Na+ deprivation on epithelial Na+ channel (ENaC, BDNF, and TrkB mRNA expression in the rat tongue

Directory of Open Access Journals (Sweden)

Stähler Frauke

2009-03-01

Full Text Available Abstract Background In rodents, dietary Na+ deprivation reduces gustatory responses of primary taste fibers and central taste neurons to lingual Na+ stimulation. However, in the rat taste bud cells Na+ deprivation increases the number of amiloride sensitive epithelial Na+ channels (ENaC, which are considered as the "receptor" of the Na+ component of salt taste. To explore the mechanisms, the expression of the three ENaC subunits (α, β and γ in taste buds were observed from rats fed with diets containing either 0.03% (Na+ deprivation or 1% (control NaCl for 15 days, by using in situ hybridization and real-time quantitative RT-PCR (qRT-PCR. Since BDNF/TrkB signaling is involved in the neural innervation of taste buds, the effects of Na+ deprivation on BDNF and its receptor TrkB expression in the rat taste buds were also examined. Results In situ hybridization analysis showed that all three ENaC subunit mRNAs were found in the rat fungiform taste buds and lingual epithelia, but in the vallate and foliate taste buds, only α ENaC mRNA was easily detected, while β and γ ENaC mRNAs were much less than those in the fungiform taste buds. Between control and low Na+ fed animals, the numbers of taste bud cells expressing α, β and γ ENaC subunits were not significantly different in the fungiform, vallate and foliate taste buds, respectively. Similarly, qRT-PCR also indicated that Na+ deprivation had no effect on any ENaC subunit expression in the three types of taste buds. However, Na+ deprivation reduced BDNF mRNA expression by 50% in the fungiform taste buds, but not in the vallate and foliate taste buds. The expression of TrkB was not different between control and Na+ deprived rats, irrespective of the taste papillae type. Conclusion The findings demonstrate that dietary Na+ deprivation does not change ENaC mRNA expression in rat taste buds, but reduces BDNF mRNA expression in the fungiform taste buds. Given the roles of BDNF in survival of

Hydrogen production by sodium borohydride in NaOH aqueous solution

Science.gov (United States)

Wang, Q.; Zhang, L. F.; Zhao, Z. G.

2018-01-01

The kinetics of hydrolysis reaction of NaBH4 in NaOH aqueous solution is studied. The influence of pH of the NaOH aqueous solution on the rate of hydrogen production and the hydrogen production efficiency are studied for the hydrolysis reaction of NaBH4. The results show that the activation energy of hydrolysis reaction of NaBH4 increased with the increase of the initial pH of NaOH aqueous solution.With the increasing of the initial pH of NaOH aqueous solution, the rate of hydrogen production and hydrogen production efficiency of NaBH4 hydrolysis decrease.

Altered Regulation of type 3 Na+/H+ exchanger, type 1 Na+/HCO3- cotransporter, and Na+,K+-ATPase in the Kidney of Rats with Experimental Rhabdomyolysis

Science.gov (United States)

Ma, Seong Kwon; Bae, Eun Hui; Lee, JongUn; Kim, Sun Young; Kim, Sung Zoo; Choi, Ki Chul

2007-01-01

Metabolic acidosis was shown to correlate with deterioration of renal function in patients with rhabdomyolysis. The present study was aimed to investigate whether the changes of type 3 Na+/H+ exchanger (NHE3), type 1 Na+/HCO3- cotransporter (NBC1), and Na+,K+-ATPase α1 subunit may play a role in the pathogenesis of metabolic acidosis in glycerol-induced experimental rhabdomyolysis. Male Sprague-Dawley rats were deprived of fluid intake for 24 hours, and then were injected with 50% glycerol in normal saline (10 mL/kg, intramuscularly). At 24 hours after the glycerol injection, rats were sacrificed by decapitation. Control rats were injected with normal saline. The protein expression of NHE3, NBC1 and Na+,K+-ATPase α1 subunit was determined in the cortex of the kidney by immunoblotting and immunohistochemistry. Following the treatment of glycerol, creatinine clearance was significantly decreased, and high anion gap metabolic acidosis developed. In the experimental group, the expression of Na+,K+-ATPase α1 subunit was significantly decreased in the cortex of the kidney. On the contrary, the expression of NHE3 and NBC1 was significantly increased. Immunohistochemical analyses confirmed the immunoblotting data. In conclusion, the coordinate up-regulation of NHE3 and NBC1 may play an adaptive role against the metabolic acidosis in glycerol-induced rhabdomyolysis. PMID:24459502

K⁺ congeners that do not compromise Na⁺ activation of the Na⁺,K⁺-ATPase

DEFF Research Database (Denmark)

Mahmmoud, Yasser A; Kopec, Wojciech; Khandelia, Himanshu

2015-01-01

The Na(+),K(+)-ATPase is essential for ionic homeostasis in animal cells. The dephosphoenzyme contains Na(+) selective inward facing sites, whereas the phosphoenzyme contains K(+) selective outward facing sites. Under normal physiological conditions, K(+) inhibits cytoplasmic Na(+) activation...

Importancia del aprendizaje de los principios básicos de alimentación y nutrición para los alumnos de ESO. Desarrollo de los recursos didácticos que sirvan para adquirir dichos conocimientos.

OpenAIRE

Casellas Ferrer, Alberto

2014-01-01

El estilo de vida, la salud y la personalidad están muy relacionados con la educación, no obstante no se le ha dado a este hecho la importancia que se merece y se ha obviado el aspecto “educativo” de los hábitos de salud, al hablar de proceso salud-enfermedad. Actualmente se considera imprescindible la intervención educativa para prevenir la enfermedad y mejorar la salud de la población La revisión de programas de educación nutricional en el entorno escolar, demuestra que se puede prevenir...

Kupokelewa Zaidi Kwa Simu Ya Mkononi Kuliko Kompyuta Na ...

African Journals Online (AJOL)

Mtandao wa tovuti ni nyenzo ya msingi katika maendeleo ya uwanja wa mawasiliano unaounganisha watu na jamii mbalimbali katika ulimwengu wa leo unaotandawaa. Katika “ulimwengu wa kwanza na wa pili”, yaani mabara ya Amerika, Uropa na Asia, maendeleo na mapinduzi makubwa katika uwanja wa teknolojia ya ...

Silicene for Na-ion battery applications

KAUST Repository

Zhu, Jiajie; Schwingenschlö gl, Udo

2016-01-01

Na-ion batteries are promising candidates to replace Li-ion batteries in large scale applications because of the advantages in natural abundance and cost of Na. Silicene has potential as the anode in Li-ion batteries but so far has not received

Coulomb excitation of radioactive 20, 21Na

Science.gov (United States)

Schumaker, M. A.; Cline, D.; Hackman, G.; Pearson, C.; Svensson, C. E.; Wu, C. Y.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Becker, J. A.; Boston, A. J.; Boston, H. C.; Buchmann, L.; Churchman, R.; Cifarelli, F.; Cooper, R. J.; Cross, D. S.; Dashdorj, D.; Demand, G. A.; Dimmock, M. R.; Drake, T. E.; Finlay, P.; Gallant, A. T.; Garrett, P. E.; Green, K. L.; Grint, A. N.; Grinyer, G. F.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Lisetskiy, A. F.; Leach, K. G.; Lee, G.; Maharaj, R.; Martin, J.-P.; Moisan, F.; Morton, A. C.; Mythili, S.; Nelson, L.; Newman, O.; Nolan, P. J.; Orce, J. N.; Padilla-Rodal, E.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Roy, R.; Ruiz, C.; Sarazin, F.; Scraggs, D. P.; Waddington, J. C.; Wan, J. M.; Whitbeck, A.; Williams, S. J.; Wong, J.

2009-12-01

The low-energy structures of the radioactive nuclei 20, 21Na have been examined using Coulomb excitation at the TRIUMF-ISAC radioactive ion beam facility. Beams of ˜ 5×106 ions/s were accelerated to 1.7MeV/A and Coulomb excited in a 0.5mg/cm^2 natTi target. Two TIGRESS HPGe clover detectors perpendicular to the beam axis were used for γ -ray detection, while scattered nuclei were observed by the Si detector BAMBINO. For 21Na , Coulomb excitation from the 3/2+ ground state to the first excited 5/2+ state was observed, while for 20Na , Coulomb excitation was observed from the 2+ ground state to the first excited 3+ and 4+ states. For both beams, B ( λ L) values were determined using the 2+ rightarrow 0+ de-excitation in 48Ti as a reference. The resulting B( E2) ↓ value for 21Na is 137±9 e^2fm^4, while the resulting B( λ L) ↓ values for 20Na are 55±6 e^2fm^4 for the 3+ rightarrow 2+ , 35.7±5.7 e^2 fm^4 for the 4+ rightarrow 2+ , and 0.154±0.030 μ_ N^2 for the 4+ rightarrow 3+ transitions. This analysis significantly improves the measurement of the 21Na B( E2) value, and provides the first experimental determination of B( λ L) values for the proton dripline nucleus 20Na .-1

Detailed investigation of Na2.24FePO4CO3 as a cathode material for Na-ion batteries

Science.gov (United States)

Huang, Weifeng; Zhou, Jing; Li, Biao; Ma, Jin; Tao, Shi; Xia, Dingguo; Chu, Wangsheng; Wu, Ziyu

2014-01-01

Na-ion batteries are gaining an increased recognition as the next generation low cost energy storage devices. Here, we present a characterization of Na3FePO4CO3 nanoplates as a novel cathode material for sodium ion batteries. First-principles calculations reveal that there are two paths for Na ion migration along b and c axis. In-situ and ex-situ Fe K-edge X-ray absorption near edge structure (XANES) point out that in Na3FePO4CO3 both Fe2+/Fe3+ and Fe3+/Fe4+ redox couples are electrochemically active, suggesting also the existence of a two-electron intercalation reaction. Ex-situ X-ray powder diffraction data demonstrates that the crystalline structure of Na3FePO4CO3 remains stable during the charging/discharging process within the range 2.0–4.55 V. PMID:24595232

Artesanato na terceira idade: um estudo na cidade de Sinop no ano de 2011

Directory of Open Access Journals (Sweden)

Rosane Marlene Weber

2015-04-01

Full Text Available Essa pesquisa tem como objetivo mostrar a importância do artesanato na Terceira Idade como atividade educacional e de autonomia para os idosos. Por existir uma preocupação com a qualidade de vida da Terceira Idade e sua autonomia, nesta fase que muitos acabam ficando dependentes dos membros da família, espera-se encontrar através da arte uma motivação e uma forma de demonstrar a autoria por meio do fazer, criar e recriar com o artesanato. Aprender e ensinar são um processo contínuo na vida do ser humano, independente da idade, para Paulo Freire precisamos ter consciência de que somos inacabados, e sendo conscientes de nossa inconclusão, devemos viver num permanente movimento de busca. Essa é uma das causas pelas quais será pesquisada a prática formativa/educacional por meio do artesanato na Terceira Idade. Os motivos que levaram a escolha desta pesquisa com o artesanato na Terceira Idade é o fato de ter vivido uma experiência de trabalho na ala geriátrica de um hospital. Já o artesanato é a arte que fascina, e acreditamos que sempre há tempo para recomeçar, para descobrir algo que possa trazer qualidade para nossa vida. Devido ao crescimento cada vez maior da expectativa de vida em nosso país, cria-se uma preocupação com a qualidade de vida das pessoas da Terceira Idade. Em relação aos aspectos educacionais e culturais, esta pesquisa deseja compreender como o artesanato pode trazer motivação para as pessoas da Terceira Idade como forma de autoria e autonomia, nesta fase da vida, na cidade de Sinop, e quais os motivos que os levam a realizar esse tipo de atividade. Para investigação teórica desta pesquisa do Artesanato na Terceira Idade: um estudo na cidade de Sinop em 2011 usaremos bibliografia de vários autores, mas em especial os que dedicam seus estudos a esta faixa etária, como a coleção de Vivaidade, que tem como organizadora principal Anita Liberalesso Neri. Os autores desta coleção nos trazem a reflex

Biphasic voltage-dependent inactivation of human NaV 1.3, 1.6 and 1.7 Na+ channels expressed in rodent insulin-secreting cells.

Science.gov (United States)

Godazgar, Mahdieh; Zhang, Quan; Chibalina, Margarita V; Rorsman, Patrik

2018-05-01

Na + current inactivation is biphasic in insulin-secreting cells, proceeding with two voltage dependences that are half-maximal at ∼-100 mV and -60 mV. Inactivation of voltage-gated Na + (Na V ) channels occurs at ∼30 mV more negative voltages in insulin-secreting Ins1 and primary β-cells than in HEK, CHO or glucagon-secreting αTC1-6 cells. The difference in inactivation between Ins1 and non-β-cells persists in the inside-out patch configuration, discounting an involvement of a diffusible factor. In Ins1 cells and primary β-cells, but not in HEK cells, inactivation of a single Na V subtype is biphasic and follows two voltage dependences separated by 30-40 mV. We propose that Na V channels adopt different inactivation behaviours depending on the local membrane environment. Pancreatic β-cells are equipped with voltage-gated Na + channels that undergo biphasic voltage-dependent steady-state inactivation. A small Na + current component (10-15%) inactivates over physiological membrane potentials and contributes to action potential firing. However, the major Na + channel component is completely inactivated at -90 to -80 mV and is therefore inactive in the β-cell. It has been proposed that the biphasic inactivation reflects the contribution of different Na V α-subunits. We tested this possibility by expression of TTX-resistant variants of the Na V subunits found in β-cells (Na V 1.3, Na V 1.6 and Na V 1.7) in insulin-secreting Ins1 cells and in non-β-cells (including HEK and CHO cells). We found that all Na V subunits inactivated at 20-30 mV more negative membrane potentials in Ins1 cells than in HEK or CHO cells. The more negative inactivation in Ins1 cells does not involve a diffusible intracellular factor because the difference between Ins1 and CHO persisted after excision of the membrane. Na V 1.7 inactivated at 15--20 mV more negative membrane potentials than Na V 1.3 and Na V 1.6 in Ins1 cells but this small difference is insufficient to solely

A neural network potential energy surface for the NaH2 system and dynamics studies on the H(2S) + NaH(X1Σ+) → Na(2S) + H2(X1Σg+) reaction.

Science.gov (United States)

Wang, Shufen; Yuan, Jiuchuang; Li, Huixing; Chen, Maodu

2017-08-02

In order to study the dynamics of the reaction H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ), a new potential energy surface (PES) for the ground state of the NaH 2 system is constructed based on 35 730 ab initio energy points. Using basis sets of quadruple zeta quality, multireference configuration interaction calculations with Davidson correction were carried out to obtain the ab initio energy points. The neural network method is used to fit the PES, and the root mean square error is very small (0.00639 eV). The bond lengths, dissociation energies, zero-point energies and spectroscopic constants of H 2 (X 1 Σ g + ) and NaH(X 1 Σ + ) obtained on the new NaH 2 PES are in good agreement with the experiment data. On the new PES, the reactant coordinate-based time-dependent wave packet method is applied to study the reaction dynamics of H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ), and the reaction probabilities, integral cross-sections (ICSs) and differential cross-sections (DCSs) are obtained. There is no threshold in the reaction due to the absence of an energy barrier on the minimum energy path. When the collision energy increases, the ICSs decrease from a high value at low collision energy. The DCS results show that the angular distribution of the product molecules tends to the forward direction. Compared with the LiH 2 system, the NaH 2 system has a larger mass and the PES has a larger well at the H-NaH configuration, which leads to a higher ICS value in the H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ) reaction. Because the H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ) reaction releases more energy, the product molecules can be excited to a higher vibrational state.

Estudo da degradação de polimeros sinteticos de importancia industrial por linhagens fungicas

OpenAIRE

Karla Cristina Freitas Costa

2001-01-01

Resumo: Este trabalho descreve a ação de fungos basidiomicetos na degradabilidade dos quatro principais polímeros sintéticos utilizados em embalagens de alimentos: polietileno tereftalato (PET), polipropileno (PP), poliestireno (PS), policloreto de vinila (PVC), e um outro polímero sintético, a espuma poliuretana (PU). Os microrganismos foram crescidos em meio líquido de sais, pH 6,8, contendo 0,1 % de tiamina, com 0,5 % do polímero sintético como única fonte de carbono durante 20, 30 e 40 di...

Effect of chloride substitution on the order–disorder transition in NaBH{sub 4} and Na{sup 11}BD{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Olsen, Jørn Eirik [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway); Karen, Pavel [University of Oslo, Department of Chemistry, P.O. Box 1033 Blindern, NO-0315 Oslo (Norway); Sørby, Magnus H. [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway); Hauback, Bjørn C., E-mail: bjorn.hauback@ife.no [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway)

2014-02-25

Graphical abstract: Interactions that order the BD{sub 4}{sup -} tetrahedra below the order–disorder transition became increasingly frustrated by the solute in the Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} solid solutions, and the order disappears at x = 0.158. Highlights: • The order–disorder transition temperature for Na(BH{sub 4}){sub 1−x}Cl{sub x} and Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} is highly dependent on the Cl-content, x. • The transition is characterized by DSC for Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} for x = 0, 0.10 and 0.15. • No transition is observed for x ⩾ 0.20 on cooling to 8 K. • The crystal structures are reported for Na{sup 11}BD{sub 4} at room temperature and 8 K and Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} (x = 0.10, 0.15, 0.20 and 0.25) at 8 K from powder neutron diffraction. -- Abstract: Phase transition associated with anion disordering over two orientations in Na{sup 11}BD{sub 4} (NaBH{sub 4}) and its solid solutions with NaCl, Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x}, is investigated with powder diffraction (neutron and synchrotron radiation), differential scanning calorimetry and Raman spectroscopy. Upon heating, the transition temperature extrapolated to zero rate of heating is 192.2 K for Na{sup 11}BD{sub 4}, ΔS = 4.41 J/mol K, hysteresis 1.7 K and the volume increase 0.43%. Thermal parameters of the transition in Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} follow a colligative-property model of an ideal solution, with x = 0.158(1) as the critical concentration at which the ordering interactions and the transition itself are eliminated. On approaching this limit, the tetragonal distortion of the ordered structure decreases somewhat towards the cubic average, and this is associated with a partial disorder of the tetrahedral anions seen by diffraction methods. In fact, a 3% disorder is already present in the pure solvent of the solid solution (Na{sup 11}BD{sub 4}) at 8 K.

TweetNaCl : a crypto library in 100 tweets

NARCIS (Netherlands)

Bernstein, D.J.; van Gastel, B.; Janssen, W.; Lange, T.; Schwabe, P.; Smetsers, S.; Aranha, D.F.; Menezes, A.

2015-01-01

This paper introduces TweetNaCl, a compact reimplementation of the NaCl library, including all 25 of the NaCl functions used by applications. TweetNaCl is published on Twitter and fits into just 100 tweets; the tweets are available from anywhere, any time, in an unsuspicious way. Distribution via

Na7 [Fe2S6 ] , Na2 [FeS2 ] and Na2 [FeSe2 ] : New 'reduced' sodium chalcogenido ferrates

Science.gov (United States)

Stüble, Pirmin; Peschke, Simon; Johrendt, Dirk; Röhr, Caroline

2018-02-01

Three new 'reduced' FeII containing sodium chalcogenido ferrates were obtained applying a reductive synthetic route. The mixed-valent sulfido ferrate Na7 [Fe2S6 ] , which forms bar-shaped crystals with metallic greenish luster, was synthesized in pure phase from natural pyrite and elemental sodium at a maximum temperature of 800 °C. Its centrosymmetric triclinic structure (SG P 1 bar , a = 764.15(2), b = 1153.70(2), c = 1272.58(3) pm, α = 62.3325 (7) , β = 72.8345 (8) , γ = 84.6394 (8) ° , Z = 3, R1 = 0.0185) exhibits two crystallographically different [Fe2S6 ] 7 - dimers of edge-sharing [FeS4 ] tetrahedra, with somewhat larger Fe-S distances than in the fully oxidized FeIII dimers of e.g. Na6 [Fe2III S6 ] . In contrast to the localized AFM ordered pure di-ferrates(III), the Curie-Weiss behavior of the magnetic susceptibility proves the rarely observed valence-delocalized S = 9/2 state of the mixed-valent FeIII /FeII dimer. The nearly spin-only value of the magnetic moment combined with the chemical bonding not generally differing from that in pure ferrates(II) and (III), provides a striking argument, that the reduction of the local Fe spin moments observed in all condensed sulfido ferrate moieties is connected with the AFM spin ordering. The two isotypic ferrates(II) Na2 [FeS2 ] and Na2 [FeSe2 ] with chain-like structural units (SG Ibam, a = 643.54(8)/ 660.81(1), b = 1140.2(2)/1190.30(2) c = 562.90(6)/585.59(1) pm, Z = 4, R1 = 0.0372/0.0466) crystallize in the K2 [ZnO2 ] -type structure. Although representing merely further members of the common series of chalcogenido metallates(II) Na2 [MIIQ2 ] , these two new phases, together with Na6 [FeS4 ] and Li2 [FeS2 ] , are the only examples of pure FeII alkali chalcogenido ferrates. The new compounds allow for a general comparison of di- and chain ferrates(II) and (III) and mixed-valent analogs concerning the electronic and magnetic properties (including Heisenberg super-exchange and double-exchange interactions

ZAZNAVA IN VPLIV BARV NA PRIMERU TISKANIH OGLASOV

OpenAIRE

Spes, Katja

2015-01-01

V diplomski nalogi smo s pomočjo literature opisali simboliko osnovnih barv, vpliv, ki ga imajo na ljudi, ter njihov pomen v oglasnih sporočilih. Omejili smo se na tiskane oglase (plakate, časopise, revije, neposredno pošto in embalažo) in opisali njihove prednosti in slabosti. Z anketnim vprašalnikom smo ugotavljali, na katere barve smo najbolj pozorni in katerim lastnostim se posamezne barve bolj približajo. Osredotočili smo se na sedem barv

Lipopolysaccharide hyperpolarizes guinea pig airway epithelium by increasing the activities of the epithelial Na(+) channel and the Na(+)-K(+) pump.

Science.gov (United States)

Dodrill, Michael W; Fedan, Jeffrey S

2010-10-01

Earlier, we found that systemic administration of lipopolysaccharide (LPS; 4 mg/kg) hyperpolarized the transepithelial potential difference (V(t)) of tracheal epithelium in the isolated, perfused trachea (IPT) of the guinea pig 18 h after injection. As well, LPS increased the hyperpolarization component of the response to basolateral methacholine, and potentiated the epithelium-derived relaxing factor-mediated relaxation responses to hyperosmolar solutions applied to the apical membrane. We hypothesized that LPS stimulates the transepithelial movement of Na(+) via the epithelial sodium channel (ENaC)/Na(+)-K(+) pump axis, leading to hyperpolarization of V(t). LPS increased the V(t)-depolarizing response to amiloride (10 μM), i.e., offset the effect of LPS, indicating that Na(+) transport activity was increased. The functional activity of ENaC was measured in the IPT after short-circuiting the Na(+)-K(+) pump with basolateral amphotericin B (7.5 μM). LPS had no effect on the hyperpolarization response to apical trypsin (100 U/ml) in the Ussing chamber, indicating that channel-activating proteases are not involved in the LPS-induced activation of ENaC. To assess Na(+)-K(+) pump activity in the IPT, ENaC was short-circuited with apical amphotericin B. The greater V(t) in the presence of amphotericin B in tracheas from LPS-treated animals compared with controls revealed that LPS increased Na(+)-K(+) pump activity. This finding was confirmed in the Ussing chamber by inhibiting the Na(+)-K(+) pump via extracellular K(+) removal, loading the epithelium with Na(+), and observing a greater hyperpolarization response to K(+) restoration. Together, the findings of this study reveal that LPS hyperpolarizes the airway epithelium by increasing the activities of ENaC and the Na(+)-K(+) pump.

Redetermination of Na(3)TaF(8).

Science.gov (United States)

Langer, Vratislav; Smrcok, Lubomír; Boca, Miroslav

2010-09-01

The crystal structure of trisodium octafluoridotantalate, Na(3)TaF(8), has been redetermined using diffractometer data collected at 153 K, resulting in more accurate bond distances and angles than obtained from a previous structure determination based on film data. The structure is built from layers running along [101], which are formed by distorted [TaF(8)] antiprisms and [NaF(6)] rectangular bipyramids sharing edges and corners. The individual layers are separated by eight-coordinated Na ions. Two atoms in the asymmetric unit are in special positions: the Ta atom is on a twofold axis in Wyckoff position 4e and one of the Na ions lies on an inversion centre in Wyckoff site 4d.

ser precoce na intervenção

OpenAIRE

Bernardo, Ana Carolina Couto

2013-01-01

Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências da Educação: Educação Especial, área de especialização em Domínio da Intervenção Precoce na Infância Este estudo centra-se na implementação de uma Escola de Mães, programa de educação parental realizado em seis sessões na freguesia de Calhetas, ilha de S. Miguel, e na avaliação comparativa, anterior e posterior ao programa, das três mães participantes no que...

Anatomía de la arteria temporal superficial: importancia quirúrgica: estudio piloto en cadáveres

Directory of Open Access Journals (Sweden)

J.J. Pradel-Mora

2015-03-01

Full Text Available El conocimiento preciso de los patrones vasculares permite mejorar los resultados de la reconstrucción regional del pabellón auricular y el diseño de colgajos regionales dependientes de la arteria temporal superficial para la reconstrucción facial. En México, no contamos en la actualidad con descripciones anatómicas de las variantes vasculares normales de la arteria temporal superficial. El objetivo de este trabajo es la descripción de las variantes anatómicas de la arteria temporal superficial a través de la disección de este vaso en 12 regiones tempo-parieto-occipitales en cadáveres. Nuestros resultados muestran que la arteria temporal superficial siempre se divide en dos ramas, una anterior y otra posterior, la distribución de ésta se sitúa en el cuarto más posterior de la región temporal, con una bifurcación alta. La distribución de la anatomía vascular, tomando en cuenta el calibre mayor de la arteria temporal superficial con respecto a la arteria auricular posterior, la ausencia de esta última en 4 de las regiones estudiadas, así como la distancia de dichos vasos con respecto al conducto auditivo externo, sugieren que en nuestra población la irrigación del pabellón auricular depende de la arteria temporal superficial, restándole importancia a la aportación del riego sanguíneo de esta región por parte de la arteria auricular posterior. Nuestro estudio arroja resultados que indican la existencia de variaciones importantes en la anatomía vascular regional que justifican la realización de estudios posteriores que permitan una descripción mas detallada de la misma para aumentar el éxito de las intervenciones quirúrgicas.

Na+/H+ exchange activity in the plasma membrane of Arabidopsis.

Science.gov (United States)

Qiu, Quan-Sheng; Barkla, Bronwyn J; Vera-Estrella, Rosario; Zhu, Jian-Kang; Schumaker, Karen S

2003-06-01

In plants, Na+/H+ exchangers in the plasma membrane are critical for growth in high levels of salt, removing toxic Na+ from the cytoplasm by transport out of the cell. The molecular identity of a plasma membrane Na+/H+ exchanger in Arabidopsis (SOS1) has recently been determined. In this study, immunological analysis provided evidence that SOS1 localizes to the plasma membrane of leaves and roots. To characterize the transport activity of this protein, purified plasma membrane vesicles were isolated from leaves of Arabidopsis. Na+/H+ exchange activity, monitored as the ability of Na to dissipate an established pH gradient, was absent in plants grown without salt. However, exchange activity was induced when plants were grown in 250 mm NaCl and increased with prolonged salt exposure up to 8 d. H+-coupled exchange was specific for Na, because chloride salts of other monovalent cations did not dissipate the pH gradient. Na+/H+ exchange activity was dependent on Na (substrate) concentration, and kinetic analysis indicated that the affinity (apparent Km) of the transporter for Na+ is 22.8 mm. Data from two experimental approaches supports electroneutral exchange (one Na+ exchanged for one proton): (a) no change in membrane potential was measured during the exchange reaction, and (b) Na+/H+ exchange was unaffected by the presence or absence of a membrane potential. Results from this research provide a framework for future studies into the regulation of the plant plasma membrane Na+/H+ exchanger and its relative contribution to the maintenance of cellular Na+ homeostasis during plant growth in salt.

Thermophysical properties of Na2Th (MoO4)3 (s) and Na4Th (MoO4)4 (s)

International Nuclear Information System (INIS)

Dash, Smruti; Rakshit, S.K.; Singh, Ziley; Keskar, Meera; Dahale, N.D.

2009-01-01

The heat capacity of Na 2 Th (MoO 4 ) 3 (s) and Na 4 Th (MoO 4 ) 4 (s) have been measured by differential scanning calorimeter in the temperature range 318 to 845 K. The corresponding values are: C p,m (Na 2 Th (MoO 4 ) 3 ,s,T) (JK-1 mol-1) 368.710+ 1.0 10-1 (T/K) - 4950267 (K/T)2 (318 ≤ T (K) ≤ 845). C p,m (Na 4 Th (MoO 4 ) 4 ,s,T) (JK-1 mol-1) = 638.761+ 5.12 10-3 (T/K) - 12691691 (K/T)-2 (318 ≤ T (K) ≤ 845). Experimental heat capacity values for Na 2 Th (MoO 4 ) 3 (s) match reasonably well with that of additive oxide values. But C p,m (T) values of Na 4 Th (MoO 4 ) 4 (s) deviates substantially from the additive oxide values above 700 K. The uncertainty of the measurements reported in this study is calculated to be within 1 to 3 % . (author)

Optimization and kinetics decomposition of monazite using NaOH

International Nuclear Information System (INIS)

MV Purwani; Suyanti; Deddy Husnurrofiq

2015-01-01

Decomposition of monazite with NaOH has been done. Decomposition performed at high temperature on furnace. The parameters studied were the comparison NaOH / monazite, temperature and time decomposition. From the research decomposition for 100 grams of monazite with NaOH, it can be concluded that the greater the ratio of NaOH / monazite, the greater the conversion. In the temperature influences decomposition 400 - 700°C, the greater the reaction rate constant with increasing temperature greater decomposition. Comparison NaOH / monazite optimum was 1.5 and the optimum time of 3 hours. Relations ratio NaOH / monazite with conversion (x) following the polynomial equation y = 0.1579x 2 – 0.2855x + 0.8301 (y = conversion and x = ratio of NaOH/monazite). Decomposition reaction of monazite with NaOH was second orde reaction, the relationship between temperature (T) with a reaction rate constant (k), k = 6.106.e - 1006.8 /T or ln k = - 1006.8/T + 6.106, frequency factor A = 448.541, activation energy E = 8.371 kJ/mol. (author)

The loss of Na and Cl during the pyrolysis of a NaCl-loaded brown coal sample

Energy Technology Data Exchange (ETDEWEB)

Mody, D.; Li, C.Z.

1999-07-01

A Victorian brown coal was physically loaded with NaCl and pyrolyzed in a quartz fluidized-bed reactor. The fluidized-bed reactor was equipped with a quartz frit in the freeboard zone to enable the total devolatilization of the coal particles. The introduction of NaCl into the coal has caused only minor reductions in the weight loss. A significant amount of chlorine was volatilized during pyrolysis at temperatures as low as 200 C. At temperatures around 400--500 C where the loss of sodium was not very significant, about 70% of chlorine was volatilized from the coal particles. With the volatilization of chlorine at this temperature level, sodium must have been bonded to the char matrix. With increasing temperature, the volatilization of chlorine decreased and then increased again, whereas the volatilization of sodium increased monotonically with increasing temperature. Almost all the Na in coal could be volatilized at temperatures higher than about 800 C. These experimental results clearly indicate that chlorine and Na interacted strongly with coal/char at high temperatures. Na and Cl in the coal did not volatilize as NaCl molecules. Significant amounts of species containing a COO-group such as acetate, formate and oxalate were observed in the pyrolysis products although the exact forms of these species (i.e., as acids, salts or esters) in the pyrolysis product remain unknown. The yields of the species containing a COO-group decreased with increasing temperature, possibly due to the intensified thermal cracking reactions at high temperatures.

Avaliação do tratamento térmico na composição química e na qualidade da cajuína Evaluation of the thermal treatment on the chemical composition and quality of "cajuína" beverage

Directory of Open Access Journals (Sweden)

Ronaldo Ferreira do Nascimento

2003-08-01

Full Text Available Neste trabalho foi estudado o efeito do processo de tratamento térmico na qualidade e composição química da bebida cajuína quando submetida ao cozimento sob temperatura constante de 100ºC durante 1:00, 1:30, 2:00, 2:30, 3:00 e 4:00 horas. Alíquotas foram coletadas em cada tempo de aquecimento e analisadas por cromatografia líquida de alta eficiência (CLAE em relação aos ácidos (cítrico e ascórbico, aldeídos furânicos (5-hidroximetilfurfural e furfural e açúcares (frutose, glicose e frutose. Os resultados foram reprodutíveis e indicaram que as cajuínas comerciais do estado do Ceará apresentam uma grande diversidade quanto ao processo de cozimento e ao teor de vitamina C, causados principalmente por processos térmicos inadequados. O tempo mais adequado sugerido para o "cozimento" da cajuína está em torno de 2:00h. O trabalho também aponta a combinação das análises de 5-HMF, furfural, ácido ascórbico e teor de ácido ascórbico/ácido cítrico como uma metodologia alternativa para a avaliação da qualidade da cajuína.In this work the effect of the thermal process on the quality and chemical composition of the beverage cajuína was studied. Cajuína is basically clarified cashew juice. Samples of cajuína were submitted to thermal processes, of constant heating (100ºC for 1:00, 1:30, 2:00, 2:30, 3:00 and 4:00 hours. The samples were subsequently analyzed by HPLC for glucose, fructose, citric acid, ascorbic acid, hydroxymethylfurfural (5-HMF and furfural. The results showed that the commercial cajuína beverage of Ceará State presented a great diversity in process standardization and vitamin C content, caused by inadequate thermal processing. The process is more efficient with a time period of 2:00hs. The work also indicates a combination of the analyses of 5-HMF, furfural and ascorbic acid and the ratio ascorbic acid/citric acid, as an alternative methodology for the evaluation of cajuína quality.

Measurement and modeling of CO2 solubility in NaCl brine and CO2–saturated NaCl brine density

DEFF Research Database (Denmark)

Yan, Wei; Huang, Shengli; Stenby, Erling Halfdan

2011-01-01

over climate change and energy security. This work is an experimental and modeling study of two fundamental properties in high pressure CO2–NaCl brine equilibrium, i.e., CO2 solubility in NaCl brine and CO2–saturated NaCl brine density. A literature review of the available data was presented first...

Five ab initio potential energy and dipole moment surfaces for hydrated NaCl and NaF. I. Two-body interactions

International Nuclear Information System (INIS)

Wang, Yimin; Bowman, Joel M.; Kamarchik, Eugene

2016-01-01

We report full-dimensional, ab initio-based potentials and dipole moment surfaces for NaCl, NaF, Na + H 2 O, F − H 2 O, and Cl − H 2 O. The NaCl and NaF potentials are diabatic ones that dissociate to ions. These are obtained using spline fits to CCSD(T)/aug-cc-pV5Z energies. In addition, non-linear least square fits using the Born-Mayer-Huggins potential are presented, providing accurate parameters based strictly on the current ab initio energies. The long-range behavior of the NaCl and NaF potentials is shown to go, as expected, accurately to the point-charge Coulomb interaction. The three ion-H 2 O potentials are permutationally invariant fits to roughly 20 000 coupled cluster CCSD(T) energies (awCVTZ basis for Na + and aVTZ basis for Cl − and F − ), over a large range of distances and H 2 O intramolecular configurations. These potentials are switched accurately in the long range to the analytical ion-dipole interactions, to improve computational efficiency. Dipole moment surfaces are fits to MP2 data; for the ion-ion cases, these are well described in the intermediate- and long-range by the simple point-charge expression. The performance of these new fits is examined by direct comparison to additional ab initio energies and dipole moments along various cuts. Equilibrium structures, harmonic frequencies, and electronic dissociation energies are also reported and compared to direct ab initio results. These indicate the high fidelity of the new PESs.

Threshold oxygen levels in Na(I) for the formation of NaCrO 2(s) on 18-8 stainless steels from accurate thermodynamic measurements

Science.gov (United States)

Sreedharan, O. M.; Madan, B. S.; Gnanamoorthy, J. B.

1983-12-01

The compound NaCrO 2(s) is an important corrosion product in sodium-cooled LMFBRs. The standard Gibbs energy of formation of NaCrO 2(s) is required for the computation of threshold oxygen levels in Na(1) for the formation of NaCrO 2(s) on 18-8 stainless steels. For this purpose the emf of the galvanic cell: Pt, NaCrO 2, Cr 2O 3, Na 2CrO 4/15 YSZ/O 2 ( P O 2 = 0.21 atm, air), Pt was measured over 784-1012 K to be: (E±4.4)(mV) = 483.67-0.34155 T(K). From this, the standard Gibbs energy of formation of NaCrO 2(s) from the elements ( ΔG f,T0) and from the oxides ( ΔG f,OX,T0) was calculated to be: [ΔG f,T0(NaCrO 2, s)±1.86] (kJ/mol) =-869.98 + 0.18575 T(K) , [ΔG f,OX,T0(NaCr0 2, s)±4.8] (kJ/mol) = -104.25-0.00856 T(K) . The molar heat capacity, C P0, of NaCrO 2(s) was measured by DSC to be (350-600 K): C P0(NaCrO 2, s) (J/K mol) = 27.15 + 0.1247 T (K) , From these data, values of -99.3 kJ/mol and 91.6 J/K mol were computed for ΔH f,2980 and S 2980 of NaCrO 2(s). The internal consistency was checked with the use of enthalpy data on Na 2CrO 4(s). From the standard Gibbs energy of formation of NaCrO 2(s) the equation logC 0(wppm) = 3.9905-3147.6 T(K) was derived, where C 0 is the threshold oxygen level for the formation of NaCrO 2(s) on 18-8 stainless steels.

PRIMERJAVA GEODETSKIH METOD NA ZAHTEVNEM GRADBENEM OBJEKTU

OpenAIRE

Reberčnik, Matic

2017-01-01

V projektni nalogi smo v uvodnih poglavjih predstavili različne načine izvajanja geodetskih meritev, ki jih v gradbeništvu uporabljamo pri analizi pomikov in deformacij gradbenih konstrukcij ter terena, na katerem so le-te postavljene. V nadaljevanju opisujemo terestične in GNSS (globalni navigacijski satelitski sistem) metode, ki smo jih uporabljali pri izvajanju meritev na izbranem premostitvenem objektu avtocestnega odseka v Sloveniji (zaradi varovanja podatkov ga imenujemo Objekt 1). Pod...

Synthesis of Li(x)Na(2-x)Mn2S3 and LiNaMnS2 through redox-induced ion exchange reactions

International Nuclear Information System (INIS)

Luthy, Joshua A.; Goodman, Phillip L.; Martin, Benjamin R.

2009-01-01

Na 2 Mn 2 S 3 was oxidatively deintercalated using iodine in acetonitrile to yield Na 1.3 Mn 2 S 3 , with lattice constants nearly identical to that of the reactant. Lithium was then reductively intercalated into the oxidized product to yield Li 0.7 Na 1.3 Mn 2 S 3 . When heated, this metastable compound decomposed to form a new crystalline compound, LiNaMnS 2 , along with MnS and residual Na 2 Mn 2 S 3 . Single crystal X-ray diffraction structural analysis of LiNaMnS 2 revealed that this compound crystallizes in P-3m1 with cell parameters a=4.0479(6) A, c=6.7759(14) A, V=96.15(3) A 3 (Z=1, wR2=0.0367) in the NaLiCdS 2 structure-type. - Graphical abstract: Structure of LiNaMnS 2 . Li and Mn are statistically distributed in edge-shared tetrahedral environments linked into infinite planes. Sodium ions occupy interlayer sites

Número de amostras na análise geoestatística e na krigagem de mapas de atributos do solo

Directory of Open Access Journals (Sweden)

Zigomar Menezes de Souza

2014-02-01

Full Text Available O objetivo deste trabalho foi analisar diferentes intensidades de amostragem do solo com relação à precisão na análise geoestatística e interpolação de mapas, para fins de agricultura de precisão em área de cana-de-açúcar. O solo foi coletado em duas grades regulares na profundidade de 0,00-0,20m para análise granulométrica (área 1 e da fertilidade do solo (área 2. Foram comparadas intensidades de amostragem do solo: 208, 105, 58 e 24 pontos na área 1 e 206, 102 e 53 pontos na área 2. Os dados foram submetidos à análise descritiva e geoestatística. Os variogramas construídos com 105 pontos não diferem dos variogramas com 208 pontos, fato que não ocorre para 58 e 24 pontos. O aumento do intervalo de amostragem e a redução do número de pontos promovem o maior erro na estimativa por krigagem. As amostragens com mais de 100 pontos por área não resultaram em melhorias significativas no erro da estimativa por krigagem, nem diferiram na quantidade de insumos aplicados em campo.

Corpo-escrita na esquizofrenia

OpenAIRE

Bialer, Marina

2014-01-01

Este artigo aborda a importância do trabalho de escrita na esquizofrenia. Toma-se como ponto de partida a formulação lacaniana sobre o esquizofrênico como aquele que não tem as funções dos órgãos do seu corpo dadas pelos discursos estabelecidos. A hipótese de que o trabalho sobre a letra pode permitir o tratamento do gozo debordante na esquizofrenia é analisada pelo estudo da obra do escritor esquizofrênico Robert Walser, a qual evidencia a viabilidade da construção de um corpo pela escrita n...

Chemisorption of Na on the Ti Nanoparticle surface and its effects on the Na-H{sub 2}O reaction reactivity

Energy Technology Data Exchange (ETDEWEB)

Kim, Soo Jae; Park, Gunyeop; Baek, Jehyun; Park, Hyun Sun [POSTECH, Pohang (Korea, Republic of); Kim, Moo Hwan [Korea institute of Nuclear Safety, Daejeon (Korea, Republic of)

2015-10-15

This accident showed that elimination of SWR risk should be one of the most significant design criteria for the development of safe SFRs. Design solutions to ensure isolation of the Na from the water have been proposed; these include double-walled structures in the steam generator and at coolant boundaries and guard vessels or guard piping lines filled with inert gas. However, those methods cannot be ultimate solutions because the system still has a possibility of failure. An alternative approach to reduce the severity of the SWR is to reduce the reactivity of Na. Recently, this goal has been achieved by suspending a small amount of Ti nanoparticles (NPs) in liquid Na. Adding 2 at% of 10-nm Ti NPs in liquid Na reduced the heat of the reaction up to 80% and H{sub 2} production rate by 10%. The number of adsorbed Na atoms onto Ti NPs with respect to the various temperature and pressure was calculated by using ab-initio and thermodynamics. Furthermore, the model which relates the Na chemisorption and SWR reactivity was proposed. The repression of SWR by Ti NPs was expected to be caused by strong chemical interaction between Ti NP surface and Na atoms; ab initio calculation using density functional theory and atomistic thermodynamic approach were conducted to test this hypothesis. Adsorption of 0.25ML Na at hcp hollow sites was the most favorable adsorption surface state and strong chemical adsorption was confirmed by the adsorption energy of -1.65 eV. A covalent-like metallic bond was confirmed between adsorbed Na and Ti atoms on the Ti(0001) surface; this bond affects the hydration energy of Na atoms and the activation barrier of the SWR. Using adsorption energy from the ab-initio calculation and atomistic thermodynamics, the thermodynamically most stable adsorption state at (T,P) was determined Na chemisorption effect on the SWR reactivity regression rate is modeled. The model predict χ variation with respect to time well especially dramatic reduction of χ; the �

O apelo ecológico na propaganda como fator de influência na atitude de compra do consumidor: um estudo experimental

OpenAIRE

Santos, João Maurício

2010-01-01

Este estudo examinou o apelo ecológico utilizado na propaganda como influenciador na atitude de compra do consumidor, tendo em vista que nas duas últimas décadas houve um crescimento nos anúncios que utilizam este tipo de apelo, demonstrando que, pelo surgimento de um novo nicho de mercado, empresas têm se valido do marketing verde e da influência normativa na sua estratégia de marketing. Buscou-se investigar se efetivamente o uso do apelo ecológico na propaganda influencia pos...

Dejavniki psihološkega nasilja na delovnem mestu

OpenAIRE

Ilc, Teja

2011-01-01

Raziskave na področju delovnih razmer kažejo, da je danes pereč problem ravno psihološko nasilje na delovnem mestu. Posebna oblika psihološkega nasilja na delovnem mestu je mobing, s katerim se v praksi srečujemo vsak dan, vendar se ga pogosto ne zavedamo. Namen magistrske naloge je pojasniti pojem in pomen mobinga v delovnih organizacijah, poiskati možne vzroke in posledice, ki vplivajo na ta pojav, ter predlagati rešitve. Poznavanje mehanizmov, ki povzročajo mobing, njegovih vzrokov in...

Anisotropy and polarization in charge changing collisions of C4+ with Na(3s) and laser aligned Na(3p)

NARCIS (Netherlands)

Hoekstra, R; Morgenstern, R; Olson, RE

1996-01-01

Absolute cross sections for C3+(6-->5) emission at 465.7 nm after collisions of C4+ ions with ground state Na(3s) and laser excited aligned Na(Sp) atoms are measured over the collision energy range of 3-7 keV amu(-1). For Na(3s) polarizations are observed by measuring the linear polarization of the

Efeito da dexametasona e do cetoprofeno na osteogênese e na resistência óssea em ratos

Directory of Open Access Journals (Sweden)

Patrícia Costa dos Santos da Silva

2012-04-01

Full Text Available O presente estudo teve como objetivo avaliar o efeito do cetoprofeno e da dexametasona na osteogênese ao redor de implante de hidroxiapatita densa (HAD na tíbia, no osso parietal, e na resistência óssea. Utilizaram-se 15 ratos Wistar, pesando 250±30 g, com 50 dias de idade. Após a anestesia com quetamina/xilazina IM, produziuse no osso parietal e na epífise proximal da tíbia uma cavidade de 3 mm, sendo implantada a HAD. Após a cirurgia os animais foram divididos em três grupos (n=5: controle (CT, anti-inflamatório não esteroidal (AINES e anti-inflamatório esteroidal (AIES. O grupo AINES foi submetido ao tratamento com cetoprofeno na dose de 12 mg/Kg/dia, o AIES recebeu doses de 0,10 mg/kg/dia de dexametasona o grupo CT recebeu solução fisiológica 0,9% (SF por via subcutânea durante 30 dias. Todos os grupos receberam a mesma dieta sólida e água ad libitum. Após 30 dias de experimento os animais sofreram eutanásia, os fêmures coletados, para teste mecânico, e os locais do implante das tíbias e o osso parietal, para análise histomorfométrica. Os grupos AINES e AIES apresentaram menor volume de osso neoformado na falha óssea e ao redor do implante de HAD , como também, menor força máxima para a ruptura completa dos fêmures, quando comparados com o grupo CT. O uso do cetoprofeno e a dexametasona interferiram na osteogênese ao redor do implante de HAD e no osso parietal, diminuindo a resistência óssea principalmente pela inibição da COX2 e diminuição das prostaglandinas, comprometendo a estabilidade e manutenção do implante.

Teaching and Popularization of Astronomy in Latin America by the Liada Perspective. (Spanish Title: Enseñanza y Divulgación de la Astronomía en la América Latina en la Perspectiva de la Liada.) Ensino e Divulgação da Astronomia na América Latina na Perspectiva da Liada

Science.gov (United States)

Bretones, Paulo Sergio

2008-12-01

Sección, faz-se una análisis y discusión sobre la importancia de tales relatos para finalidades educacionales. Es presentada una Hoja de reporte elaborado como sugestión para presentación de relatos por parte de individuos y instituciones ben como discutida la importancia de la sistematización de experiencias visando mayor visibilidad y cambio de informaciones en el área. Concluí con una evaluación de los proyectos, su potencial y limitaciones, ben como sugestiones de proyectos futuros visando mayor interacción entre los países de la América Latina y tornando disponible la Sección para esta finalidad. Esse trabalho visa divulgar e analisar as atividades da Seção de Ensino e Divulgação de Astronomia (SEDA) da Liga Iberoamericana de Astronomia (LIADA). Após um histórico da LIADA, são apresentados os diversos projetos da Seção que conta com a colaboração de coordenadores locais na maioria dos países da América Latina. São apresentados os projetos que visam chamar a atenção do público em geral, estudantes e professores para a observação do céu e posterior envio de relatos para colocação na página da Seção na Internet. Mais especificamente são analisados os projetos e relatos relacionados aos eclipses ocorridos desde o ano 2000. Utilizando-se os arquivos disponibilizados na página da Seção, faz-se uma análise e discussão sobre a importância de tais relatos para finalidades educacionais. É apresentado um formulário elaborado como sugestão para apresentação de relatos por parte de indivíduos e instituições bem como discutida a importância da sistematização de experiências visando maior visibilidade e troca de informações na área. Conclui com uma avaliação dos projetos, seu potencial e limitações, bem como sugestões de projetos futuros visando maior interação entre os países da América Latina e tornando disponível a Seção para esta finalidade.

Nalaz tombusvirusa na vrsti Erigeron canadensis L.

OpenAIRE

Jeknić, Zoran; Erić, Živojin; Grbelja, Julijana

1988-01-01

Iz listova zaraženih primjeraka korovne biljke Erigeron canadensis L. koji su rasli na nekoliko lokaliteta u Sarajevu izoliran je virus iz skupine tombusvirusi. Identifikacija virusa izvršena je na osnovi reakcije pokusnih biljaka, analize ultratankih presjeka kroz zaraženo tkivo, morfologije i veličine virusnih čestica, te na osnovi seroloških reakcija metodom dvostruke imunodifuzije u agarskom gelu i čvrsto fazne imunoelektronske mikroskopije (SPIEM). U serološkim pokusima upotrijebljen je ...

Transcriptional regulators of Na, K-ATPase subunits

OpenAIRE

Zhiqin eLi; Sigrid A Langhans

2015-01-01

The Na,K-ATPase classically serves as an ion pump creating an electrochemical gradient across the plasma membrane that is essential for transepithelial transport, nutrient uptake and membrane potential. In addition, Na,K-ATPase also functions as a receptor, a signal transducer and a cell adhesion molecule. With such diverse roles, it is understandable that the Na,K-ATPase subunits, the catalytic alpha-subunit, the beta-subunit and the FXYD proteins, are controlled extensively during developme...