Reproducción asistida y filiación. Tres casos

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Bernal Crespo, Julia Sandra

2013-01-01

Este artículo analiza uno de los principales problemas jurídicos que plantean las técnicas de reproducción asistida: determinar la filiación del nacido y la forma en que nuestros jueces de la República han resuelto este conflicto en los casos específicos de alquiler de vientre, inseminación asistida con donante, e inseminación post-mortem, teniendo en cuenta que, a diferencia de la filiación biológica, el consentimiento de los donantes de gametos y de los receptores es un elemento necesario p...

Eficacia de vibraciones transtorácicas más in-exuflación mecánica versus:técnicas manuales para tos asistida en pacientes pediátricos con parálisis cerebral grave o profunda

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Vergara Lozano, Pedro

2014-01-01

Las infecciones respiratorias recurrentes son frecuentes en la Parálisis Cerebral (PCI). La tos asistida manual (TAM) y mecánica (TM) persigue preservar las funciones del aparato respiratorio. Objetivo:. Evaluar la eficacia del tratamiento con vibraciones transtorácicas más insuflación-exuflación mecánica frente a las técnicas manuales, para inducir tos asistida en pacientes pediátricos con PCI grave o profunda. Método: 40 niños con PCI hospitalizados por infecciones respiratorias con edad me...

Propuesta de mejora de habilidades sociales en niños con discapacidad intelectual mediante la terapia asistida por animales

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Bermejo Lorenzo, Julia

2015-01-01

Este Trabajo de Fin de Grado se centra en la aplicación práctica de un programa de mejora de la Educación Socioemocional, utilizando como herramienta innovadora la Terapia Asistida con Animales de Compañía, aplicándose a un caso real de un alumno con Parálisis Cerebral y Discapacidad Intelectual asociada. Los objetivos de las actividades están centrados en el desarrollo de la autoconciencia, el autocontrol, la conciencia social y la toma de decisiones responsables. Mediante este proyecto se p...

Determinación de elementos minoritarios, traza y ultratraza en biopsias procedentes de pacientes con diferentes patologías tumorales mediante ETAAS, ICP-OES e ICP-MS utilizando extracción asistida por ultrasonidos y multigestión de bajo volumen

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Millos Alfeiran, Jorge

2012-01-01

El objetivo principal de esta tesis doctoral es la determinación de metales minoritarios, traza y ultratraza en tejidos tumorales humanos mediante el desarrollo de metodologías analíticas adecuadas y robustas que permitan obtener resultados precisos y exactos, de manera que puedan ser aplicadas al análisis de rutina. En este sentido, se ha buscado la solución óptima a cada uno de los problemas planteados. Para llevar a cabo este objetivo se han evaluado la extracción ácida asistida por ult...

La reproducción asistida ante el Tribunal Europeo de Derechos Humanos: de Evans c. Reino Unido a Parrillo c. Italia

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Farnós Amorós, Esther

2016-01-01

Pese a que la mayoría de ordenamientos europeos regulan las técnicas de reproducción asistida, ello no reduce la diversidad existente entre los estados miembros por lo que respecta a cuestiones especialmente sensibles, tales como las condiciones de acceso estas técnicas; el uso del diagnóstico genético preimplantacional para evitar que un hijo sea portador de una determinada enfermedad genética; el recurso a técnicas heterólogas o con gametos donados; los efectos que deben otorgarse a los acu...

Analysis of assisted gait by a telemetric system ANÁLISIS DE LA MARCHA ASISTIDA CON BASTONES MEDIANTE UN SISTEMA TELEMÉTRICO

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L.P. Rodríguez

2010-09-01

Full Text Available In this paper, a new system of teletransmission to analyse the walk during reeducation is presented. The system is made of three emitting sensors housed into the two canes and the feet switches, which assit the patient during the ambulatory function. An adaptating circuit is put between the emitter and the antenna to eliminate the interferences caused by simultaneous signals in the same area.

KEY WORDS: Telemetry. Gait analysis. Assisted gait.

PALABRAS CLAVE: Telemetría. Análisis de la marcha. Marcha asistida.

Liposucción láser-asistida en ginecomastia: seguimiento ecográfico y estadístico de los efectos observados de retracción cutánea

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M.A. Trelles

2013-12-01

Full Text Available Valoramos por ecografía y estadísticamente la eficacia de la liposucción láser-asistida en casos de ginecomastia, teniendo en cuenta la respuesta de retracción de la piel, la rapidez de la recuperación del paciente, y el grado de satisfacción que originan los resultados. Presentamos un estudio prospectivo de 28 pacientes con ginecomastia de diferente grado, tratados mediante liposucción asistida por láser de Diodo de 1470 nm, previa sedación y con anestesia tumescente. El láser se programó a 15 Watios (W en emisión continua y se administraron 8 a 12 kilojulios (kJ por cada mama. No se realizaron escisiones de piel ni se emplearon drenajes. Se realizó valoración objetiva y subjetiva empleando la misma escala visual analógica (VAS completada por médicos y pacientes. Se tomaron fotografías antes y 6 meses después de la intervención, y se realizaron mediciones del perímetro torácico y del diámetro de las areolas. El seguimiento ecográfico de las áreas tratadas fue comparativo antes y 6 meses después del tratamiento. Para el estudio estadístico se empleó t de Student como test de contraste. No observamos complicaciones, como signos de isquemia o quemaduras cutáneas. La disminución del perímetro torácico y del diámetro de las areolas fue estadísticamente significativa. Tanto la valoración objetiva como la subjetiva alcanzaron resultados superiores al 90 %. Mediante la ecografía también se demostró disminución, estadísticamente significativa, de la banda de tejido graso subcutáneo (p < 0,05 al comparar las imágenes de antes y 6 meses después del tratamiento. La recuperación laboral se realizó en un promedio de 3 días. En conclusión, creemos que la liposucción láser-asistida es un método eficaz y reproducible, comprobado ecográfica y estadísticamente, que alcanza buenos resultados con menos trauma quirúrgico, lo que conlleva un alto grado de satisfacción por parte de los pacientes.

Criterios en la selección de pacientes para optimizar resultados en liposucción asistida por láser de abdomen y flancos: análisis de 340 cirugías

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J. Moreno-Moraga

2014-12-01

Full Text Available El objetivo de nuestro estudio es valorar mediante ecografía y análisis estadístico la respuesta a la liposucción asistida por láser en abdomen y flancos. Para ello, se tuvo en cuenta la disminución del tejido adiposo, la retracción cutánea y el grado de satisfacción de las pacientes con los resultados. Realizamos un estudio retrospectivo sobre 340 cirugías en pacientes multíparas mayores de 40 años, con o sin diástasis de rectos, que rechazaron la abdominoplastia con lipectomía. Las intervenciones se efectuaron mediante liposucción a respectivamente en 924 y 9/5 11111, bajo sedo-analgesia y con anestesia tumescente. Los láseres se programaron para emisión en modo continuo, actuando al unísono con potencia de 20 W hasta alcanzar un promedio de entre 10 a 12 kJ de energía acumulada para los flancos, y de entre 12 a 18 kJ para el abdomen. La valoración subjetiva y objetiva se realizó mediante escala GAIS (Global Aesthetic Improvement Scale. Se tomaron fotografías antes, 1 y 6 meses después de la intervención. En abdomen se realizaron ecografías antes y 6 meses después de la cirugía, y se empleó t de Student como test de contraste para el estudio analítico. En 60 pacientes seleccionados aleatoriamente como muestra representativa se realizaron fotografías digitales de la superficie de la piel a fin de valorar comparativamente por programa de ordenador la textura-flacidez de la condición del tejido antes, 1 y 6 meses después de la cirugía. En ninguno de los resultados se observó isquemia y/o quemaduras. La disminución del tejido adiposo, según las ecografías, fue estadísticamente significativa (p<0,05 comparativamente a los 6 meses del tratamiento. La valoración de las fotografías antes y 6 meses después de la cirugía por un médico ajeno al estudio, al igual que la textura-flacidez cutánea, fue Buena o Muy Buena. La valoración subjetiva por cuestionarios de escala GAIS alcanzó un 57,1% (194 pacientes al

La filiación por tecnologías de reproducción asistida : Voluntad y deseo, saber y ficción

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Kletnicki, Armando; Alfano, Adriana

2013-01-01

El actual Proyecto de Código Civil y Comercial de la Nación instituye una tercera fuente de filiación a partir de las Tecnologías de Reproducción Humana Asistida (TRHA), convocándonos a pensar el abanico de posibilidades que se abren a partir de la intervención de la ciencia en el origen de la vida. Hasta el advenimiento de estas tecnologías la procreación sólo podía efectivizarse mediante el sostén de relaciones íntimas entre personas de distinto sexo, situación que garantizaba la plena coin...

La gestaci??n por sustituci??n y el permiso de maternidad

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Garc??a L??pez, Ver??nica

2015-01-01

La ???gestaci??n por sustituci??n??? es un contrato llevado a cabo por una mujer gestante y unos padres futuros en el cual se acuerda la transmisi??n del ni??o tras el embarazo. En nuestro ordenamiento jur??dico espa??ol se encuentra prohibida dicha pr??ctica, concretamente, se encuentra regulada en la Ley 14/2006, de 26 de mayo de 2006, sobre T??cnicas de Reproducci??n Humana Asistida. Fuera de nuestro Estado existen otros ordenamientos jur??dicos extranjeros que prev??n esta posibilidad ...

Uso de selección asistida con marcadores para resistencia a antracnosis en fríjol común

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Garzón Luz Nayibe

2007-12-01

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La antracnosis causada por Colletotrichum lindemuthianum puede llegar a generar pérdidas hasta del 95% de la producción en fríjol (Phaseolus vulgaris L., por eso es considerada una de las enfermedades más limitantes. Con el presente trabajo se inició un programa de mejoramiento utilizando selección asistida por marcadores. Se usó como parental resistente el cultivar Mesoamericano G2333, para incorporar a fríjoles volubles comerciales de Colombia los genes Co-5 y Co-4² , que confieren resistencia a C. lindemuthianum. Se obtuvieron progenies RC₁F₁ provenientes de cruces entre G2333 y siete parentales volubles tipo Bola roja y Rojo moteado cultivados en zonas productoras de fríjol de Cundinamarca y Boyacá. La selección de plantas RC₁F₁ se realizó con los marcadores moleculares SCAR SAB3 y SAS13, ligados a los genes Co-5 y Co-4² , respectivamente. En la evaluación genotípica de 1.271 plantas RC₁F₁, 608 amplificaron con SAB3 y 603 con SAS13. La segregación para cada marcador se ajustó a la razón 1:1 esperada en pruebas de chi-cuadrado (X² = 2,38, P= 0,12 para SAB3 y X² = 3,32, P= 0,07 para SAS13. Un total de 299 plantas RC₁F₁ amplificaron con ambos SCAR, ajustándose a la razón esperada (X²= 1,11, P= 0,78 y confirmando la segregación independiente. Estas plantas fueron seleccionadas para continuar el programa de mejoramiento, ya que se espera que porten los genes Co-5 y Co-4². Se logró implementar la selección asistida por marcadores para antracnosis, y acelerar la introducción y piramidación de genes de resistencia en fríjol de importancia económica en Colombia.

Validación empírica de las Intervenciones Psicoeducativas Asistidas con Caballos sobre las Necesidades Educativas Especiales de niños/as con Trastorno Autista

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Castro Cadenas, Isabel

2016-01-01

Esta investigación se basa en la realización de un estudio experimental para valorar la eficacia de las intervenciones psicoeducativas asistidas con caballos sobre las dificultades de los/as niños/as con autismo desde el enfoque del análisis conductual aplicado. El método de la investigación consiste en la evaluación mediante hojas de registro conductuales y cuestionario realizado por la estudiante; así como en la aplicación de tres intervenciones a tres participantes con Trastorno Autista qu...

Prevalencia de las úlceras por presión en una residencia asistida de mayores Prevalence of pressure ulcers in an assisted residence for the elderly

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J.M. Díaz Pizarro

2007-09-01

Full Text Available Se recogieron datos de 282 residentes distribuidos en las diferentes áreas asistenciales de una residencia asistida de mayores, con el objetivo de analizar la prevalencia de lesiones por presión y sus características, así como el estado funcional y psíquico de los usuarios para poder realizar un estudio descriptivo de su situación actual. Se observó una prevalencia del 13,47% de UPP con una mayor presencia en talones y una media de edad de 82,93 años. Además, se analizaron factores que aumentan el riesgo de aparición de UPP, con especial atención a la presencia de incontinencia, uso de suplementos nutricionales y a las medidas de prevención como cambios posturales y colchones antiescaras.We made a survey and collected data from 283 people distributed in the different welfare areas of an assisted residence for the elderly in order to analyse the prevalence of pressure ulcers as well as their functional and psychic conditions of the users to develop a descriptive report of their current situations. A prevalence percentage of 13,47 was found, the sores in their heels being the most spread ones and within people at the average age of 82,93. Besides, there were analyzed factors that increase the risk of PUs appearance with special attention to the presence of incontinence, use of nutritional supplements and the prevention measures as position changes and no injure mattresses.

Terapia asistida con animales y cuidados de enfermería : una revisión de la literatura más reciente

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Salazar Calleja, Alma

2016-01-01

Introducción. La terapia asistida con animales en el ámbito sanitario se remonta al siglo XI. Con el paso del tiempo y la aparición de nueva evidencia científica que avala el gran número de beneficios derivados de sus efectos terapéuticos, dichas terapias han adquirido cierta popularidad. Objetivos.El objetivo principal de este trabajo es conocer los resultados de la terapia asistida con animales; y como objetivo secundario determinar cuál es el papel de la enfermería. Métodos. Para analizar ...

Valoración y parametrización del P3HT como capa absorbente en LIFT

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Codina Álvarez, Francisco Javier

2016-01-01

Un novedoso proceso, desarrollado a partir de la impresión 3D convencional, es la impresión biológica, la cual se aborda con diferentes técnicas ya sea: por inyección de tinta, por extrusión, asistida por microválvulas, por fragmentos de tejido o asistida por láser. El método más prometedor es la impresión asistida por láser para proyectar gotas de tinta bilógica sobre una superficie, que, aunque es mucho más difícil de implementar debido al coste y a la tecnología necesaria, reúne buenos asp...

Dilemas bioéticos y jurídicos de la reproducción asistida en la sociedad actual en España

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Pablo Enguer Gosálbez

2018-01-01

Full Text Available Este trabajo analiza algunos problemas jurídicos y bioéticos que no están resueltos por la legislación aplicable a la reproducción asistida, uno de los campos más controvertidos de la medicina y la biotecnología humana. Se centra especialmente en el ámbito de los nuevos modelos familiares heterosexuales y homosexuales, así como el caso de parejas que tengan una enfermedad preexistente, la controversia referente a la selección de embriones no portadores de enfermedades en el caso del diagnóstico genético preimplantatorio, la selección del sexo, la fecundación in vitro mixta, procreación post mortem, entre otros. En definitiva, se presta atención al modo como se ha efectuado la regulación y a las valoraciones éticas, con el propósito de alcanzar conclusiones después de conocer los argumentos emitidos por la doctrina y reflexionar acerca de los aspectos mejorables de nuestra legislación, con propuestas concretas de lege ferenda.

DIDACTIC OF MATHEMATICS TEACHING ASSISTED WITH COMPUTER / DIDÁCTICA DE LAS FUNCIONES LINEALES Y CUADRÁTICAS ASISTIDA CON COMPUTADORA

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Zully Lucía Alfonzo Salgado

2012-07-01

Full Text Available This paper aims to describe the characteristics of the didactic of teaching of mathematics assisted with computer with emphasis on graphing. To achieve the proposed objectives was documentary research by descriptive analysis, whose basic purpose was to design a teaching-learning strategy in the area of mathematics using technology. The notion of constructivism fits the assisted learning with technological tool, where learning is reflective and structures are constructed by the student, allow developing logical reasoning. We conclude that it is an effective didactic in mathematic class, in addition, provides outreach and assessment of developments in science, encouraging student creativity guiding him toward a more independent life.RESUMENEl presente trabajo tiene como objetivo describir las características de la didáctica de la enseñanza de la matemática asistida con computadora con énfasis en graficación. Para el logro de los objetivos planteados se hizo una investigación documental, mediante un análisis descriptivo, cuyo propósito básico fue diseñar una estrategia de enseñanza-aprendizaje en el área de matemática usando tecnología. La noción de constructivismo encaja con la enseñanza asistida con herramienta tecnológica, donde el aprendizaje es reflexivo y las estructuras son construidas por el estudiante, permitiendo desarrollar el razonamiento lógico. Se concluye que es una didáctica efectiva en la enseñanza de la matemática, además facilita el acercamiento y valoración de los adelantos de la ciencia, estimulando la creatividad del estudiante guiándolo hacia una vida más independiente.

Producción y tratamiento de películas de Si_1-xGe_x mediante técnicas asistidas por láser de excímero

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Castro, J.

1998-04-01

Full Text Available Heterostructures of Si_1-xGe_x alloys on Si (100 have been achieved using two different excimer laser techniques. The first one, the Laser Induced Chemical Vapour Deposition (LCVD, was used in order to deposit germanium on Si (100 substrates via photolysis of GeH₄ as precursor gas. The resulting films show a very homogeneous and amorphous structure as determined by HREM, XRD and Raman analysis. These deposited amorphous germanium films and a part of their underlaying Si (100 substrate were melted using the second technique, the Pulsed Laser Induced Epitaxy (PLIE, inducing an epitactic recrystallization of a Si-Ge alloy. The analysis of the obtained alloys by HREM, XRD, and XPS, reveals a strong dependence of the crystal quality and of the germanium concentration profile from the number of pulses.

El creciente interés que suscita la búsqueda de nuevas técnicas para la obtención de materiales semiconductores, compatibles con la tecnología del silicio, ha llevado a desarrollar un sistema de depósito y postprocesado en alto vacío (HV de Si-Ge mediante técnicas asistidas por láser excímero. Se han obtenido películas amorfas de germanio mediante el depósito químico en fase vapor inducido por láser (LCVD, que posteriormente han sido recristalizadas con uso de la inducción de epitaxia por medio de láser pulsado (PLIE. Las películas depositadas sobre substratos de silicio fueron caracterizadas mediante XRD, HREM y Raman, revelándose que son amorfas con un alto grado de homogeneidad. Se ha estudiado la morfología y la estequiometría de las muestras por medio de XRD, HREM y XPS tras el tratamiento para inducir la cristalinidad de la aleación sobre el substrato de silicio, observándose la dependencia del grado de heteroepitaxia y variación de la composición en la aleación, con el número y la energía de los pulsos del láser.

¡Quiero ser madre! Las técnicas de reproducción asistida como vía de acceso a la maternidad en solitario

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Manuela Avilés Hernández

2015-06-01

Full Text Available Este artículo se centra en las mujeres que sin tener pareja han decidido ser madres mediante las técnicas de reproducción asistida. El interés se pone en la experiencia personal e íntima que han vivido desde que se plantearon la posibilidad de recurrir a estas técnicas hasta que finalmente se convirtieron en madres. Para ello, se identifican tres focos de atención: el momento de la toma de decisión; el proceso en sí mismo de fecundación, embarazo y parto; y la valoración global de la experiencia con la llegada del hijo/a. Para abordar estas cuestiones se realizan 15 entrevistas a mujeres que optaron por esta vía para acceder a la maternidad.

Molienda asistida con microondas de un coque metalúrgico

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Ruisánchez, Esteban

2014-06-01

Full Text Available Metallurgical cokes are composed of graphitic carbon (s2p2 and different inorganic compounds with very different capacities to absorb microwave radiation. Moreover, due to the electric conductivity shown by the metallurgical cokes, microwave radiation produces electric arcs or microplasmas, which gives rise to hot spots. Therefore, when these cokes are irradiated with microwaves some parts of the particle experiment a rapid heating, while some others do not heat at all. As a result of the different expansion and stress caused by thermal the shock, small cracks and micro-fissures are produced in the particle. The weakening of the coke particles, and therefore an improvement of its grindability, is produced. This paper studies the microwave-assisted grinding of metallurgical coke and evaluates the grinding improvement and energy saving.Los coques metalúrgicos están compuestos mayoritariamente de carbono grafítico (s2p2 y diferentes compuestos inorgánicos con distintas capacidades de absorber la radiación de microondas. Cuando se irradian con microondas fragmentos de estos coques, algunas partes de las partículas experimentan un rápido calentamiento, mientras otras no. Además, debido a que el coque presenta una cierta conductividad eléctrica, al ser irradiados con microondas se producen de forma puntual arcos eléctricos o microplasmas, dando lugar a puntos muy calientes. Como consecuencia de las diferentes dilataciones y tensiones producidas por el choque térmico, se producen en las partículas pequeñas grietas y microfisuras. Esto produce una mayor fragilidad en las partículas de coque y un incremento en la molturabilidad de las mismas. En el presente artículo se estudia la molienda de coque asistida con microondas y se evalúan las mejoras en la molturabilidad y el ahorro de energía producido.

La reproducción humana asistida en el contexto de los derechos humanos

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Maria Olga Sánchez Martínez

2013-12-01

Full Text Available Al abordar la legislación sobre Reproducción Humana Asistida, el legislador realiza una labor de mediación entre distintos derechos y principios que, en su pretensión de justicia, no está exenta de controversia. Tal labor no se realiza desde un punto de vista neutral, se han de tener en cuenta distintas opciones éticas e ideológicas propias de una sociedad democrática, sin abandonar la coherencia con el desarrollo de los distintos derechos humanos en juego, en definitiva, esa ética pública que configura los sistemas culturales, sociales y políticos: el derecho a la vida, a la dignidad, al libre desarrollo de la personalidad, a fundar una familia, a la intimidad personal y familiar, a la identidad, a la maternidad, a la salud, a la producción y creación científica y a gozar de los beneficios del progreso científico. Algunas Sentencias del Tribunal Europeo de Derechos Humanos y de la Corte Interamericana de Derechos Humanos inciden en estos derechos al tratar las Reproducción Humana Asistida, lo cual permite, más allá de las legislaciones concretas, esbozar algunos consensos sobre unas técnicas en constante evolución, como las sociedades en las que tales técnicas se ponen a disposición de sus ciudadanos.

Familias de madres solas por elección como contextos para el desarrollo infantil

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Díez López, Marta

2015-01-01

Se denominan madres a solas por elección a aquellas mujeres adultas que deciden adoptar, recurrir a técnicas de reproducción asistida, buscar un padre biológico o continuar un embarazo no buscado a priori, pero aceptado y convertido en deseado, y lo hacen desde la decisión activa de no compartir esta tarea con una pareja (Mannis, 1999; Pakizegi, 2012; Walters, 1991; Weinraub et al., 2002). La literatura anglosajona las denomina “single mother by choice” o “solo mother” e incluye tanto a las q...

Septoplastia submucosa asistida por endoscopia más reducción nasal cerrada en fracturas nasoseptales: estudio comparativo frente a la técnica tradicional

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Nicolás Pereira

Full Text Available Resumen Introducción y Objetivos La fractura de los huesos propios nasales es la más frecuente de las fracturas faciales y su hallazgo concomitante con fractura septal varía desde un 34% a un 96.2%. Es necesario un abordaje adecuado para evitar complicaciones como obstrucción nasal y deformidades nasoseptales postraumáticas. El objetivo de este trabajo es presentar la técnica de asistencia endoscópica como alternativa para el tratamiento de lesiones septales agudas y compararla con los resultados del abordaje tradicional de esta patología. Material y Método Revisión retrospectiva de casos de fracturas nasoseptales entre enero de 2010 y abril del 2014 en los que se realizó reducción nasal cerrada más septoplastia abierta (técnica tradicional o reducción nasal más septoplastia submucosa asistida por endoscopía (SSAE. Describimos la técnica quirúrgica y presentamos resultados. Resultados Recogimos 123 pacientes: 33 casos con técnica tradicional y 90 casos con SSAE. Todos debidos a accidentes laborales o en el trayecto hacia/desde el trabajo. Ambos grupos fueron comparables. El tiempo promedio transcurrido entre el accidente y la cirugía tradicional fue 11.4 días y para SSAE fue de 15 días. No se presentaron complicaciones intraoperatorias con ninguna de las técnicas. Hubo 5 pacientes (15.15% operados con técnica tradicional y 3 (3.3% con SSAE que evolucionaron con obstrucción nasal y/o laterorrinia; requirieron rinoseptoplastia secundaria (diferencia estadísticamente significativa. Conclusiones La SSAE para tratamiento de fracturas nasoseptales supone una innovación que reduce la tasa de rinoseptoplastias secundarias en comparación con la técnica tradicional y lo reportado en la literatura. Es además una técnica reproducible y de bajo costo.

Introducción a la terapia asistida con animales: tipologías de terapia en España

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García Martín, Carmen

2011-01-01

Se hace una revisión teórico-bibliográfica sobre la terapia asistida con animales, centrándose en animales como perros, caballos y delfines, en los diferentes ámbitos de intervención en España, incluyendo datos recogidos sobre los resultados de este tipo de terapia en algunas asociaciones del país

LA SIMULACIÓN COMO HERRAMIENTA DE APRENDIZAJE EN FÍSICA

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Luisa Casadei Carniel

2008-01-01

Full Text Available En la presente investigación se estudió el efecto de la aplicación de un diseño instruccional apoyado con simulaciones asistidas por el computador, en un grupo de estudiantes que cursaban la asignatura Física a nivel universitario. El diseño de la investigación fue cuasi-experimental, de un solo grupo con pre-postest de carácter transeccional descriptivo, bajo un enfoque cuanti-cualitativo. Los hallazgos de la investigación fueron: (a el mejoramiento de la comprensión de los conceptos cinemáticos en los estudiantes al aplicarse estrategias instruccionales apoyadas en simulaciones asistidas por el computador y (b mejora del rendimiento académico obtenido por los estudiantes al aplicarse estrategias instruccionales basadas en el uso de simulaciones asistidas por el computador.

Gestación por sustitución: ni maternidad subrogada ni alquiler de vientres

OpenAIRE

Lamm, Eleonora

2013-01-01

La gestación por sustitución es una forma alternativa de acceder a la paternidad o maternidad, en el marco de las técnicas de reproducción humana asistida. Se trata de una práctica cada vez más frecuente, pues se estima que en la actualidad nacen unos veinte mil niños cada año como consecuencia de un acuerdo de este tipo. Esta obra expone la realidad de esta práctica, la gran cantidad de jurisprudencia nacional e internacional existente, las distintas opciones legales que recoge el derecho...

Influencia de la obesidad en las técnicas de reproducción asistida

OpenAIRE

Llaneza Suárez, David

2012-01-01

En el presente trabajo fin de Máster se pretende valorar como afecta el IMC a los resultados de las técnicas de reproducción asistida, así como comprobar que el diseño del estudio es el adecuado para valorar un proyecto de investigación más amplio basado en el estudio del papel que desempeñan algunas adipokinas como la leptina o el TNF-α. En este trabajo fin de máster se analizaron los siguientes parámetros: Tasa de embarazo, número de folículos puncionados, número de ovocitos recuperados,...

ESTUDIO SINTÉTICO Y CARACTERIZACIÓN POR INFRARROJO DE DERIVADOS 2-(AMINO-1,4-NAFTOQUINONA Y SU EVALUACIÓN ANTIBACTERIANA PRELIMINAR

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Marlene Lariza Andrade-Guel

2011-01-01

Full Text Available Las naftoquinonas son compuestos de origen natural o sintético que han mostrado importantes actividades biológicas, resaltando como agentes antibacterianos, antifúngicos, antimaláricos y anticancerígenos. En el presente trabajo se reportan los resultados de la síntesis utilizando diferentes métodos como la síntesis a temperatura ambiente (STA, síntesis por calentamiento convencional (SCC y síntesis asistida por ultrasonido (SAU de los derivados 2-(amino-1,4-naftoquinona. Se realizó su caracterización por espectroscopía de infrarrojo. Además se determinó su capacidad como agentes antibacterianos frente a las cepas Proteus sp. y Enterococcus faecalis. La mayor actividad lo mostró el derivado 2-bencilamino 1,4-naftoquinona.

La bioética en el escenario de las tecnologías de reproducción humana asistida

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Irene CAMBRA BADII

2016-04-01

Full Text Available Los avances de las Tecnologías de Reproducción Humana Asistida nos confrontan con nuevos escenarios y prácticas cuya interrogación resulta necesaria. A través de la narrativa cinematográfica, en el recorte del film Starbuck o su remake Delivery man (Ken Scott, Canadá, 2011; EEUU, 2013, podremos desplegar distintos ejes de análisis en relación a la Inseminación Artificial con Donante, en la cual se dirimen el derecho a la identidad y el derecho a la privacidad.La historia del protagonista del film narra dos sucesos que cambian el curso de su vida: su novia le desvela que ha quedado embarazada y que piensa tener al niño sin contar con su ayuda, y ese mismo día le comunican que le han interpuesto una demanda ya que David ha donado esperma hace alrededor de veinte años, y como resultado, han nacido 533 hijos, de los cuales 142 quieren averiguar su nombre para conocerlo.Lo inédito de esta situación nos lleva a analizarla desde tres vertientes, por el lado del derecho, desde la bioética, y desde la responsabilidad, con la mirada puesta en la subjetividad.

La maternidad como situación protegida en el Derecho del Trabajo y en el Derecho de la Seguridad Social. En especial la maternidad por subrogación.

OpenAIRE

González Quintero, David

2016-01-01

El contrato de maternidad subrogada está declarado nulo de pleno derecho en España en base a la Ley 14/2006 referida a las Técnicas de Reproducción Humana Asistida. En primer lugar, afrontaremos el problema del reconocimiento de la inscripción de la filiación de los menores nacidos por esta técnica, para luego, con el fin de analizar el tema objeto de este trabajo, estudiar si existe derecho a las prestaciones por maternidad en el supuesto de la maternidad subrogada. De esta manera, tras un a...

Estudio del diagnóstico social en residencias para personas mayores asistidas en la Comunidad de Madrid: diseño de un instrumento de valoración y diagnóstico social

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Silvia Patricia Cury

2009-12-01

Full Text Available El presente artículo es el resultado de la investigación, realizada por la autora, en el marco del Postgrado en Trabajo Social Comunitario, Gestión y Evaluación de Servicios Sociales, de la Escuela Universitaria de Trabajo Social, de la Universidad Complutense de Madrid, a lo largo del curso académico 2008-2009, que fue presentada como Memoria Final de Investigación, el día 7 de julio de 2009, bajo la dirección del Profesor Andrés Arias Astray. Esta Memoria se fundamenta en la importancia del diagnóstico como elemento decisivo de toda intervención social, y su finalidad consiste en realizar una aportación metodológica en este ámbito. En concreto, se realizó el estudio de la situación del diagnóstico social, en el ámbito de la atención a las personas mayores en Residencias asistidas de la Comunidad de Madrid y, en función de sus resultados, se elaboró el diseño de un Instrumento de Diagnóstico Social, para su aplicación en dicho ámbito. La elección del mismo responde a varios factores, que determinan su importancia y pertinencia, en el momento actual en las Residencias para personas mayores asistidas. Ente ellos, destaca la implantación de los Protocolos Asistenciales para Residencias de Mayores en la Comunidad de Madrid, y las necesidades de las trabajadoras sociales de integrarse en este proceso de protocolización, la actual situación demográfica en España y las previsiones al respecto, con un número creciente de personas mayores, los cambios sociológicos acaecidos en la institución familiar, y por lo tanto el desafío asistencial que estos factores suponen para la atención a las personas mayores en Centros Residenciales.

Intervenciones asistidas con animales desde el punto de vista de los cuidados de enfermería

OpenAIRE

Peña Dávila, María de la Salud

2016-01-01

Introducción: Las necesidades crecen; la enfermería debe renovarse, así nace la "Enfermería de Práctica Avanzada", entendida como una especialidad que al ejercerse requiere conocimiento experto, capacidad de toma de decisiones complejas y experiencia clínica para el ejercicio ampliado de la profesión. Para conseguir el abordaje holístico de las necesidades del individuo, nacen las "Terapias No Farmacológicas", entre las que destacan las Intervenciones Asistidas con Animales. Éstas, son apl...

Desenvolvimento e implantação de Terapia Assistida por Animais em hospital universitário Desarrollo y aplicación de la Terapia Asistida por Animales en el hospital universitario Development and implementation of Animals-Assisted Therapy in a universitary hospital

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Cassia Tiemi Kobayashi

2009-08-01

Full Text Available O presente relato refere-se à experiência da Diretoria de Enfermagem do Hospital São Paulo da Universidade Federal de São Paulo no desenvolvimento e implantação da Terapia Assistida por Animais, como um de seus projetos de humanização hospitalar: "Projeto Amicão". Objetivando proporcionar aos pacientes uma experiência positiva que difere da rotina do ambiente hospitalar, algumas unidades do Hospital São Paulo receberam a visita de um animal para sessões de Terapia Assistida por Animais. Os resultados alcançados entre pacientes, acompanhantes e profissionais da saúde foram positivos, além de despertar a atenção e o interesse de outras instituições de saúde e da mídia. Ficou, assim, evidenciada a importância de se relatar a experiência do "Projeto Amicão" no ambiente hospitalar.Este informe se refiere a la experiencia de la Junta de Enfermería, Hospital de Sao Paulo (HSP, Universidad Federal de Sao Paulo en el desarrollo y el despliegue de la Terapia Asistida por Animales (TAA, como uno de sus proyectos de humanización del hospital: "Proyecto Amicão". Con la finalidad de ofrecer los pacientes una experiencia positiva que difiere de la rutina del entorno hospitalario, algunas unidades de lo HSP recibió la visita de un animal para los períodos de sesiones de TAA. Los logros entre los pacientes, sus acompañantes y profesionales de la salud fueron positivos, y despertó la atención y el interés de otras instituciones de salud y de los medios de comunicación. Es así de relieve la importancia de comunicar la experiencia del "Proyecto Amicão" en el hospital.This report refers to the experience of the Board of Nursing of Hospital São Paulo, Universidade de São Paulo, in the development and implantation of Animal-Assisted Therapy, as one of its projects humanization of hospital: "Projeto Amicão". Aiming to offer patients a positive experience that differs from the routine of the hospital environment, some units of the

Monoparentalidad por elección: procesos de socialización de los hijos/as en un modelo familiar no convencional

OpenAIRE

Poveda, David; Jociles Rubio, Maribel; Rivas, Ana Mª

2011-01-01

En este artículo presentamos parte de los resultados de un proyecto de investigación centrado en familias monoparentales por elección. El estudio recoge datos en tres comunidades autónomas del Estado Español e incluye entrevistas a madres embarcadas en proyectos familiares en solitario (a través de adopción internacional, acogimiento permanente, técnicas de reproducción asistida y fecundación sexual con donante conocido) y a sus hijos/as sobre sus experiencias familiares, observación de difer...

Terapias asistidas con animales: síntomas y funcionalidad en trastornos del espectro autista y demencia senil

OpenAIRE

González Rosauro, Belén

2012-01-01

En este trabajo se realiza un recorrido teórico acerca de los principales aspectos que engloba la terapia asistida con animales, una modalidad terapéutica con una base histórica sólida que actualmente goza de una popularidad en creciente desarrollo. Los numerosos estudios realizados han sido capaces de verificar las grandes ventajas que supone realizar una terapia de este tipo como complemento a otros tratamientos principales, además de los cuantiosos beneficios de los animales para el ser hu...

O conceito de mal radical The concept of radical evil

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Adriano Correia

2005-01-01

Full Text Available A noção de mal radical aparece em Kant no contexto da discussão da religião nos limites da simples razão e busca dar conta da complexa relação entre o respeito pela lei moral e o amor-próprio na definição do móbil para a ação. Na busca por identificar o fundamento da propensão para o mal no homem, Kant se vê diante da dificuldade de ter de articular natureza e liberdade, e ainda que a noção de mal radical possa conservar algumas ambigüidades, permite conceber uma noção de responsabilidade compatível com uma inata propensão para o mal. Neste texto busco explicitar alguns passos fundamentais na construção do conceito por Kant.The concept of radical evil appears in Kant's theory when he discusses the religion in the limits of the mere reason and aims explain the complex relationship between respect for the moral law and the self-love, for establish the motive of the action. By aiming identify the basis of human inclination to evil, Kant is faced with the trouble of have to put nature and freedom in connection. Despite of the concept of radical evil retain some ambiguity, it allows conceive a notion of responsibility suitable to an inherent inclination to evil. In this paper is my purpose to explain some basic moments of Kantian formulation of that notion.

Experiencias en el desarrollo de una aplicación robótica con control de fuerza para taladrado de huesos

OpenAIRE

J.C. Fraile; J. Pérez-Turiel; J.L. González-Sánchez; J. López-Cruzado; J.L. Rodríguez

2008-01-01

Resumen: En los sistemas de cirugía ortopédica asistida por ordenador (CAOS), el taladrado del hueso en la reparación de fracturas de huesos largos (para estabilizarlos con placas, clavos o tornillos) es una tarea compleja que el cirujano debe realizar con gran precisión, evitando el calentamiento excesivo del tejido óseo. En la cirugía asistida por robots, se han utilizado principalmente robots industriales (Robodoc, Caspar, Crigos) adaptados a ambientes quirúrgicos para ayudar al cirujano e...

ESCONDER O ENFRENTAR. SILENCIAR O REVELAR. EL DERECHO A CONOCER LOS ORÍGENES DE LAS PERSONAS NACIDAS POR TÉCNICAS DE REPRODUCCIÓN HUMANA ASISTIDA

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Marianela Lourdes Germain

2015-09-01

Full Text Available En este trabajo, la autora pretende determinar la posibilidad de conocer los orígenes de seres humanos nacidos bajo técnicas de reproducción humana asistida. Para ello, procedió a analizar el régimen proyectado en el territorio nacional, conjuntamente, a un análisis de las regulaciones extranjeras. Comprendidos en su trabajo se encuentran las visiones acerca de los derechos de toda persona a formar una familia; los derechos de los niños, niñas y adolescentes; y el derecho de los terceros involucrados en estas técnicas. Asimismo, realizo una reseña sobre cuestiones históricas y sociológicas, entre otras, que hacen al contexto de estas técnicas; permitiéndole arribar a la conclusión de que el derecho a conocer los orígenes necesita de un abordaje interdisciplinario, que debe darse no sólo desde el Estado; sino especialmente dentro del marco del seno familiar, con los debidos cuidados y afecto que sólo la familia puede brindar; todo esto acompañado de una necesaria y fundamental construcción social para insertar estos cambios en la cultura del país.

Coste de las técnicas de reproducción asistida en un hospital público Cost of assisted reproduction technology in a public hospital

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José Luis Navarro Espigares

2006-10-01

Full Text Available Objetivos: La mayoría de trabajos sobre costes de las técnicas de reproducción asistida (TRA identifican el coste directo del procedimiento, sin considerar elementos como los costes estructurales o intermedios, de gran importancia. El objetivo de este trabajo es calcular el coste por proceso de las TRA realizadas en un hospital público en 2003 y compararlo con los resultados de 1998 en el mismo centro. Métodos: El estudio se realiza en la Unidad de Reproducción Humana (URH del Hospital Universitario Virgen de las Nieves de Granada en 1998 y 2003. Partiendo de los costes totales de dicha unidad, y mediante una metodología de distribución de costes basada en la estructura de costes, calculamos el coste por proceso de las TRA realizadas en este centro, considerando los costes completos. Resultados: Entre 1998 y 2003, la actividad y los costes de la URH analizada evolucionan de forma distinta. El análisis de la actividad muestra la consolidación de técnicas, como la microinyección espermática (ICSI y la desaparición de otras (ciclo sin reproducción asistida e inseminación artificial conyugal intracervical. En todos los procesos, los costes unitarios por ciclo y por embarazo disminuyen en el período analizado. Conclusiones: Se han producido importantes cambios en la estructura de costes de las TRA de la URH-HUVN entre 1998-2003. Mientras algunos procesos desaparecen, otros se consolidan con una elevada actividad. Los avances técnicos y las innovaciones organizativas, junto con un «efecto aprendizaje», han alterado la estructura de costes de las TRA.Objectives: Most studies on the costs of assisted reproductive technologies (ART identify the total cost of the procedure with the direct cost, without considering important items such as overhead or intermediate costs. The objective of this study was to determine the cost per ART procedure in a public hospital in 2003 and to compare the results with those in the same hospital in 1998

Relacionismo substancial: a ontologia do comportamento à luz do behaviorismo radical

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Diego Zilio

Full Text Available Sob a influência do pragmatismo e contextualismo pepperiano, analistas do comportamento extraíram do behaviorismo radical qualquer posição ontológica. Como resultado, há a defesa de um relacionismo radical no qual a única propriedade relevante para a existência do comportamento é a própria relação que o define. O objetivo deste ensaio é avaliar a pertinência dessa posição. Três questões guiram esse trabalho: (1 Por que a substância não é importante para o behaviorismo radical?; (2 Por que a substância é importante para o behaviorismo radical?; e (3 Qual seria, de fato, o posicionamento ontológico mais condizente com o behaviorismo radical? Argumenta-se que o relacionismo radical não reflete com acurácia a ontologia behaviorista radical e sugere-se que o relacionismo substancial seja a posição mais coerente.

Filtrado Adaptativo de Componentes Involuntarias en Marcha Asistida por Andador para Detección de Intenciones

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A. Frizera

2011-04-01

Full Text Available Resumen: En este trabajo, se presenta un método de filtrado adaptativo para la eliminación de las componentes involuntarias de las fuerzas de interacción entre el usuario y el andador por el apoyo de sus miembros superiores. Este proceso se basa en la atenuación selectiva de componentes relacionadas con las oscilaciones del tronco del sujeto durante la marcha. Para ello, se hace la estimación de la cadencia de marcha en tiempo real procesando las señales de distancia obtenidas por un subsistema ultrasónico mediante el algoritmo Weighted-Frequency Fourier Linear Combiner (WFLC. Este subsistema suministra la distancia entre los pies del usuario y el andador en tiempo real. La cadencia a su vez es usada para el ajuste de un filtro notch adaptativo construido a partir del algoritmo Fourier Linear Combiner (FLC que realiza el filtrado en tiempo real de las señales obtenidas del subsistema de medición de fuerzas de apoyo de antebrazos. El método propuesto ofrece una cancelación robusta y en tiempo real de cerca del 80% de la amplitud de las componentes indeseadas de frecuencia. La salida del algoritmo de filtrado propuesto permite así evidenciar componentes de fuerzas de bajo nivel pero muy importantes ya que están generadas por acciones intencionales y naturales asociadas a las intenciones de guiado del andador. Estas componentes serán utilizadas en el control de los motores del andador basándose en una arquitectura de control clásico que será desarrollada posteriormente. Palabras clave: Robótica de rehabilitación, interfaz hombre-máquina, filtrado adaptativo, detección de intenciones, marcha humana

Metal-Diazo Radicals of α-Carbonyl Diazomethanes

Science.gov (United States)

Li, Feifei; Xiao, Longqiang; Liu, Lijian

2016-03-01

Metal-diazo radicals of α-carbonyl diazomethanes are new members of the radical family and are precursors to metal-carbene radicals. Herein, using electron paramagnetic resonance spectroscopy with spin-trapping, we detect diazo radicals of α-carbonyl diazomethanes, induced by [RhICl(cod)]2, [CoII(por)] and PdCl2, at room temperature. The unique quintet signal of the Rh-diazo radical was observed in measurements of α-carbonyl diazomethane adducts of [RhICl(cod)]2 in the presence of 5,5-dimethyl-pyrroline-1-N-oxide (DMPO). DFT calculations indicated that 97.2% of spin density is localized on the diazo moiety. Co- and Pd-diazo radicals are EPR silent but were captured by DMPO to form spin adducts of DMPO-N• (triplet-of-sextets signal). The spin-trapping also provides a powerful tool for detection of metal-carbene radicals, as evidenced by the DMPO-trapped carbene radicals (DMPO-C•, sextet signal) and 2-methyl-2-nitrosopropane-carbene adducts (MNP-C•, doublet-of-triplets signal). The transformation of α-carbonyl diazomethanes to metal-carbene radicals was confirmed to be a two-step process via metal-diazo radicals.

Multiculturalismo radical y feminismos de mujeres de color

OpenAIRE

Lugones, María

2005-01-01

En el núcleo lógico mismo del movimiento hacia un multiculturalismo radical y de los feminismos de las Mujeres de Color, se da un desplazamiento desde una lógica de la opresión hacia una lógica de la resistencia. Ya sea radical, estructural o policéntrico, el multiculturalismo es una repuesta radical al eurocentrismo que ha acompañado a la historia del colonialismo occidental. El colonialismo en la primera y en la última modernidad estaba constituido por una concepción eurocéntrica ...

Resultados refractivos en pacientes operados por LASIK versus LASEK con mitomicina C Refractive results in patients operated by LASIK versus LASEK with Mitomycin C

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Abel Cabrera Martínez

2009-06-01

Full Text Available OBJETIVO: Evaluar comparativamente los resultados refractivos obtenidos en ojos operados con el uso de la keratomileusis in situ asistida con láser (LASIK contra la keratomileusis subepitelial asistida con láser combinándosele a esta última el uso de la mitomicina C (LASEK+MC. MÉTODOS: Se realizó un estudio prospectivo, experimental, comparativo en un total de 210 ojos de pacientes que acudieron a consulta para ser operados por algún defecto refractivo. Un total de 104 ojos fueron intervenidos por LASIK y 106 por LASEK+MC. Para comparar los resultados del estudio se realizaron varios exámenes antes y después de operados los pacientes. RESULTADOS: Los defectos refractivos fueron superiores con significación estadística (pOBJECTIVE: Evaluating comparatively the refractive results obtained in eyes operated by keratomileusis in situ assisted with laser (LASIK versus keratomileusis subepithelial assisted with laser plus Mitomycin C (LASEK + MC. METHODS: A prospective, experimental and comparative study was performed in 210 eyes of patients who went to see the specialist to be operated from some refractive defect. A total of 104 eyes were operated by LASIK and 106 by LASEK + MC. In order to compare the results of study, several tests were made before and after surgery. RESULTS: The refractive defects were greater with statistical significance (p< 0,05, for Student's t for the eyes operated by LASEK + MC. The visual result of the LASEK with MC surgery was better than that of LASIK. Haze was a problem resolved for the LASEK when included Mitomycin C in patients with high myopia, in addition to improvement of quality of life of the patients. CONCLUSIONS: The corneal surgery with laser through the LASEK technique plus use of Mitomycin C demonstrated being as reliable as that with LASIK for ametropy correction, since it provides additional advantages that increases the quality of life of patient, with less postoperative risks.

Natural healers: a review of animal assisted therapy and activities as complementary treatment for chronic conditions Curadores naturales: una revisión de la terapia y actividades asistidas por animales como tratamiento complementar de enfermedades crónicas Curadores naturais: uma revisão da terapia e atividades assistidas por animais como tratamento complementar de doenças crônicas

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Reiley Reed

2012-06-01

Full Text Available The primary objective of this review is to synthesize the existing literature on the use of animal-assisted therapy and activity (AAT/A as complementary treatment among people living with chronic disease and to discuss the possible application of this practice among children living with HIV. Relevant databases were searched between March 10 and April 11, 2011, using the words: animal assisted therapy or treatment and chronic conditions or diseases. Thirty-one articles were found and 18 followed the inclusion and exclusion criteria. Research suggests that AAT/A is effective for different patient profiles, particularly children. Interaction with dogs has been found to increase positive behaviors, such as sensitivity and focus, in children with social disabilities. Decreased levels of pain have also been reported among child patients as a result of AAT/A. More research should be done in the area of children living with chronic diseases that require strict adherence to treatment, such as HIV, and on AAT/A's prospective use as an educational tool to teach children about the importance of self-care for their medical conditions.El objetivo de esta revisión fue describir la literatura existente sobre el uso de terapia y actividades asistidas por animales (AAT/A, como terapia coadyuvante en personas viviendo con enfermedades crónicas, y discutir la posible aplicación de esa práctica en niños que viven con SIDA. La información fue buscada en bancos de datos entre 10 de marzo y 11 de abril de 2011, usando las palabras: terapia asistida por animales o tratamiento y condiciones crónicas o enfermedades. Treinta y uno artículos fueron encontrados y 18 siguieron los criterios de inclusión y exclusión. La pesquisa sugiere que AAT/A es eficaz para pacientes con diferentes perfiles, especialmente para niños. Se descubrió que la interacción con perros incrementa comportamientos positivos como aumento de la sensibilidad y atención en los niños con

Tratamiento legal del contrato de gestaci??n por sustituci??n en el Derecho Internacional Privado espa??ol a la luz de la STS de 6 de febrero de 2014. Dime ni??o, ??de qui??n eres...?

OpenAIRE

??lvarez Rodr??guez, Aurelia; Carrizo Aguado, David

2014-01-01

P. 59-75 En el ordenamiento jur??dico espa??ol, es nulo de pleno derecho el convenio derivado de gestaci??n por sustituci??n, en virtud de lo dispuesto en el art. 10 de la Ley 14/2006, de 26 de mayo, sobre t??cnicas de reproducci??n humana asistida. Dada esta prohibici??n, los ciudadanos espa??oles han acudido a otros ordenamientos jur??dicos extranjeros que admiten la posibilidad de convertirse en padres de un ni??o nacido de una mujer con la que se suscribe un contrato de ??v...

La simulación como herramienta de aprendizaje en física / Simulation as physics learning tool

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Alvarez Vargas, Zulma

2008-08-01

Full Text Available Resumen: En la presente investigación se estudió el efecto de la aplicación de un diseño instruccional apoyado con simulaciones asistidas por el computador, en un grupo de estudiantes que cursaban la asignatura Física a nivel universitario. El diseño de la investigación fue cuasi-experimental, de un solo grupo con pre-postest de carácter transeccional descriptivo, bajo un enfoque cuanti–cualitativo. Los hallazgos de la investigación fueron: (a el mejoramiento de la comprensión de los conceptos cinemáticos en los estudiantes al aplicarse estrategias instruccionales apoyadas en simulaciones asistidas por el computador y (b mejora del rendimiento académico obtenido por los estudiantes al aplicarse estrategias instruccionales basadas en el uso de simulaciones asistidas por el computador.Abstract: The focus of the present research was to investigate the effect of the application of an instructional design supported by computer-based simulations in a group of students enrolled on a Physics course. The study was quasi-experimental, performed in one single group, with pre-post test of transectional descriptive character, in both quantitative and qualitative modes. The results revealed that (a understanding of the concepts within the topic, kinematics, was improved by the instructional strategy using computer-based simulations and (b the academic performance of the students improved with the use of computer-based simulations.

Cuerpo, derechos y salud integral: Análisis de los debates parlamentarios de las leyes de Identidad de Género y Fertilización Asistida (Argentina, 2011-2013

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Anahí Farji Neer

2015-01-01

Full Text Available En este artículo se analizan los debates parlamentarios de la Ley 26743 de Identidad de Género y de la Ley 26862 de Fertilización Asistida, desarrollados en el Congreso Nacional argentino entre los años 2011 y 2013. A través de la técnica de análisis de contenido cualitativo se analizan las versiones taquigráficas de los debates parlamentarios con el fin de responder los siguientes interrogantes: ¿cómo fue caracterizado el problema público al cual ambas leyes darían respuesta?, ¿cómo fue conceptualizada la misión de ambas leyes?, ¿en qué medida dicha definición implicó poner en entredicho las nociones de salud y enfermedad con relación a la cobertura de tratamientos de optimización o modificación corporal por parte del sistema público de salud? El proceso de sanción de ambas leyes implicó tensionar los conceptos de salud y enfermedad como categorías morales. En dicho marco emergió una noción ampliada del concepto de salud integral que incluyó los deseos reproductivos y corporales de los ciudadanos y ciudadanas.

Analgesia preventiva y multimodal con ketamina y dipirona en mastectomía radical por cáncer de mama

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Miladys Justo Hernández

2015-11-01

Full Text Available El dolor agudo es frecuente en los pacientes que requieren intervención quirúrgica; su tratamiento satisfactorio es uno de los retos más importantes, presentando ventajas la terapéutica multimodal y preventiva. Se realizó un estudio longitudinal, prospectivo en 22 pacientes, a los que se les practicó mastectomía radical por cáncer de mama, con el objetivo de describir el uso de la analgesia multimodal y preventiva con ketalar y dipirona en el manejo del dolor posoperatorio de estos pacientes. La técnica anestésica utilizada fue total intravenosa, con propofol y fentanyl, dosis convencional. En el postoperatorio se vigiló la aparición de efectos colaterales. Los datos se colocaron en tablas de contingencia, procesados mediante el sistema de cálculos estadísticos que presenta Microsoft Excel. El análisis se realizó fundamentalmente a través de medidas de resúmenes, porcentaje y media aritmética. Se concluyó que la analgesia multimodal preventiva con ketamina y dipirona fue efectiva y segura en todos los casos, a los que se realizó radical de mama. Predominó el grupo de edad entre 46 y 65 años y ASA II. Las variables hemodinámicas y respiratorias se mantuvieron estables en todos los pacientes. No necesitaron analgesia de rescate. La somnolencia se manifestó en 13,6% de los casos.

Terapia asistida por animales de compañía aplicada en una residencia geriátrica en el medio rural.

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Muñoz Gómez, Bárbara

2013-01-01

Establecemos en qué ámbitos de la evaluación geriátrica se detectan cambios por la utilización de la TAAC en un grupo de mayores institucionalizados en una residencia del medio rural. La población está formada por 23 personas, la mayoría mujeres, de edad media 86,04 ± 7,89, viudas, que saben leer y escribir, amas de casa y que trabajan en el campo, padecen patologías cerebrales, consumen analgésicos y ansiolíticos, y acuden más veces al médico en Junio. Intervenimos en 12 sesiones s...

Possíveis relações entre o contexto histórico e a recepção do behaviorismo radical

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Robson Nascimento da Cruz

Full Text Available O artigo discute a recepção do behaviorismo radical, em especial, na década de 70, e busca relacionar a polêmica em torno de algumas noções skinnerianas acerca da liberdade e da dignidade divulgadas no livro Para Além da Liberdade e Dignidade. Essa discussão foi orientada por três conjuntos de questões: a a incompatibilidade entre alguns aspectos históricos e a definição behaviorista radical de liberdade e dignidade; b os problemas em identificar o behaviorismo radical como uma abordagem solidária com os pressupostos de uma ideologia liberalista; c a linguagem utilizada por Skinner como fonte de problemas. Por fim, são discutidos as limitações e os problemas envolvidos em tentativas de esclarecimentos de possíveis mal-entendidos acerca do behaviorismo radical. Ao mesmo tempo, demonstra-se que a recepção do behaviorismo radical é perpassada por aspectos além daqueles relacionados à validade interna do sistema explicativo skinneriano, e que discordâncias acerca dessa abordagem nem sempre podem ser explicadas como desconhecimento e equívocos sobre a mesma.

Estrés percibido, ansiedad, depresión e ira en el proceso de reproducción asistida : un estudio de caso

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Pérez Ortega, Melania; Barraca Mairal, Jorge

2014-01-01

En el artículo se presenta un caso donde se analiza la presencia del estrés, la tristeza, la ansiedad, la ira y el desajuste emocional a lo largo de la aplicación de una técnica de reproducción asistida (Microinyección Espermática-ICSI). Se evaluó a una pareja, ambos de 34 años, antes de comenzar ICSI, durante las fases del proceso y posteriormente. Para la evaluación de sintomatología a lo largo de la intervención médica se utilizaron el BDI-II, el STAI, el STAXI-2...

Resistencia a la corrosión a alta temperatura de recubrimientos NiCrAlY y NiCrFeNbMoTiAl depositados por APS

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José Luis Tristancho-Reyes

2014-12-01

Full Text Available La corrosión a alta temperatura de las tuberías utilizadas en equipos generadores de vapor (calderas ha sido reconocida como un grave problema que trae consigo el adelgazamiento de éstas y, por consiguiente, la falla de los equipos. En la última década se han incrementado las investigaciones que involucran recubrimientos protectores que ayudan de alguna manera a prolongar la vida útil de estos equipos. Esta investigación determinó el comportamiento de los recubrimientos NiCrAlY y NiCrFeNbMoTiAl depositados por proyección térmica asistida por plasma (APS sobre la aleación SA213 – T22 (2¼Cr – 1Mo, en un ambiente corrosivo de 80%V2O5–20%K2SO4 a 800°C. Los valores de la cinética de corrosión fueron determinados mediante resistencia a la polarización lineal (RPL y espectroscopia de impedancia electroquímica (EIE. Los resultados obtenidos muestran una menor cinética de corrosión en el recubrimiento NiCrFeNbMoTiAl que la presentada por el recubrimiento NiCrAlY, corroborado por Microscopia Electrónica de Barrido (MEB.

Complicações maternas e ocorrências neonatais associadas às gestações múltiplas resultantes de técnicas de reprodução assistida Complicaciones maternas e eventos neonatales asociados con gestaciones múltiples resultantes de técnicas de reproducción asistida Maternal complications and neonatal events associated to multiple pregnancies resulting from assisted reproduction techniques

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Viviane Rodrigues Graner

2009-03-01

Full Text Available A gestação múltipla é a mais freqüente e a mais séria complicação iatrogênica das técnicas de reprodução assistida. O objetivo do estudo foi conhecer as complicações maternas e as ocorrências neonatais associadas às gestações múltiplas resultantes de reprodução assistida em um centro de referência na área de reprodução assistida. Trata-se de uma pesquisa observacional, transversal, descritiva e retrospectiva que foi realizada no Hospital e Maternidade Santa Joana, centro de referência na área de reprodução humana localizado no município de São Paulo, Brasil. A população estudada foi constituída por 131 prontuários de gestantes internadas com patologias clínicas e trabalho de parto, advindas de gestações múltiplas resultantes de técnicas de reprodução assistida. As complicações maternas predominantes foram: o trabalho de parto prematuro (65,5%, a amniorrexe prematura (42%. As ocorrências neonatais mais freqüentes foram as doenças respiratórias (65,1%, a icterícia (38,4%, os distúrbios metabólicos (13% e as doenças neurológicas (9%.La gestación múltiple es la más frecuente y corresponde a la más seria complicación iatrogénica de las técnicas de reproducción asistida. El objetivo del estudio fue conocer las complicaciones maternas y los eventos neonatales asociados a las gestaciones múltiples resultantes de la reproducción asistida en un centro de referencia en el área de reproducción asistida. Se trata de una investigación observacional, transversal, descriptiva y retrospectiva que fue realizada en el Hospital y Maternidad Santa Joana, centro de referencia en el área de reproducción humana, localizado en el municipio de São Paulo, Brasil. La población estudiada fue constituida por 131 registros de gestantes internadas con patologías clínicas y trabajo de parto, provenientes de gestaciones múltiplas resultantes de técnicas de reproducción asistida. Las complicaciones

NARRATIVAS RELIGIOSAS Y POLÍTICAS EN LA DISPUTA POR LA EDUCACIÓN SEXUAL EN ARGENTINA

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Juan Cruz Esquive

2013-12-01

Full Text Available La educación sexual, junto con la distribución gratuita de anticonceptivos y de la píldora del ‘día después’, el matrimonio entre personas del mismo sexo, la fecundación asistida, la autodeterminación de la identidad sexual, la eutanasia y la despenalización del aborto, conforman uno de los ‘núcleos sensibles’ que cristalizan pujas y negociaciones entre el Estado, la dirigencia política y las instituciones religiosas a la hora de definir los fundamentos regulatorios de las políticas públicas en esos tópicos. El trabajo focaliza la mirada en las controversias semánticas entabladas por el Ministerio de Educación de la República Argentina y la Conferencia Episcopal, una vez aprobada la Ley Nacional de Educación Sexual Integral en 2006. El análisis de contenido de las principales publicaciones sobre educación sexual divulgadas por ambas instituciones, permitirá identificar los elementos de continuidad y de ruptura entre las tramas discursivas políticas y religiosas, así como las disputas por la construcción del discurso social legitimado. El abordaje propuesto habilita una entrada privilegiada para comprender las lógicas que se activan en la definición de determinadas políticas públicas y legislaciones, contemplando tanto las estrategias de influencia de las instituciones religiosas en el diseño e implementación de las mismas, como los niveles de receptividad de las demandas de contenido religioso por parte de los ‘decisores’ políticos.

NAVA: Nuevo modo de Ventilación

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Martín Lorenzo, María del Carmen; Montón Giménez, Nuria; Paz Martín, Daniel

2013-01-01

La Ventilación Asistida Ajustada Neuronalmente (NAVA) es un nuevo modo de Ventilación Mecánica Asistida que utiliza la actividad eléctrica diafragmática (Edi) para el control del respirador. La Edi es registrada a través de un catéter esofágico, y representa directamente el impulso respiratorio central y, por lo tanto, la duración y la intensidad con que el paciente desea ventilar. La asistencia inspiratoria mecánica se inicia en el momento en que el centro respiratorio lo demanda, y el di...

Estrategias pedagógicas en el proceso de aprendizaje de Manufactura por Mecanizado utilizando software CAM (Manufactura asistida por computador), en el programa de Ingeniería Mecánica de la Universidad Central.

OpenAIRE

Pérez Orozco, Pedro William; Reyes Vergara, José Mauricio

2016-01-01

El presente documento, tiene por objeto plantear un proceso estructurado para el aprendizaje de la manufactura por mecanizado asistido por computador, encaminado a subsanar o corregir las falencias detectadas en el proceso de enseñanza, al pasar de una metodología dirigida al contexto del mecanizado efectuado en máquinas convencionales, en las cuales se deben realizar todos y cada uno de los procedimientos por parte de un operario, y establecer los cálculos necesarios para elaborar un produc...

Anestesia para timectomía toracoscópica, vídeo asistida: Reporte de 4 casos

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Mercedes Argudín Cordero

2000-06-01

Full Text Available La timectomía toracoscópica con vídeo asistida en el niño es un hecho verdaderamente novedoso en Cuba, en atención a la incidencia de la miastenia gravis en la población joven, aunque dicho procedimiento no está exento de producir complicaciones; ahora bien, si se tiene en cuenta la técnica clásica de abordaje del timo, éstas son mínimas. En el presente trabajo se relaciona la información correspondiente de 4 pacientes, de uno y otro sexos, adolescentes, ASA II y programados para cirugía mayor electiva (timectomía, en los cuales se midieron: frecuencia cardíaca, electrocardiograma, presión arterial sistólica y diastólica respectivamente, frecuencia respiratoria, temperatura esofágica, oximetría de pulso y capnometría, antes, durante y después del procedimiento. Se obtuvieron resultados que concuerdan con la literatura médica revisada, y se concluye como una superior alternativa en los pacientes con miastenia gravis, por las bondades que se observan en los aspectos de baja invasividad, mínimas complicaciones y menor estadía hospitalaria.Video-assisted thoracoscopic thymectomy in children is a real novelty in Cuba to take care of the incidence of myasthenia gravis in the young population. Although such method is not wholly complication-free, if we compare it with the classical technique to thymus approach, then the risks are minimal. The present paper provides information on 4 patients of both sexes, adolescents, ASA II and due to undergo major elective surgery (thymectomy. Parameters such as heart rate, electrocardiogram, systolic and diastolic arterial pressures, respiratory rate, esophagic temperature, pulse oxymetry and capnometry were measured before, during and after surgery. The results achieved were in line with the reviewed literature so the conclusion was reached that this technique is a better choice for patients with myasthenia gravis because of the advantages it offers such as low invasiveness, minimum

Madres solteras por elección: entre el “engaño” y la solidaridad

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María Isabel Jociles

2010-05-01

Full Text Available En este artículo se analizan los discursos sobre las motivaciones que las Madres Solteras por Elección (MSPE aducen para optar, o no, por las diferentes vías de acceso a la monoparentalidad electiva que ellas mismas distinguen: la que denominan “el engaño”, esto es, la fecundación sexual planificada pero no declarada, la fecundación sexual mediante “donante conocido”, la fecundación asistida y la adopción internacional. Estos discursos, producidos tanto en entrevistas cualitativas como en otros contextos de interacción (foros de Internet, kedadas, reuniones de amigas, etc., han sido objeto de observación en el contexto de una investigación etnográfica realizada en la Comunidad de Madrid (España durante el periodo 2008-2009. Dichos discursos ponen de manifiesto, en primer lugar, que las MSPE manejan una gran variedad de concepciones acerca de la maternidad y el vínculo materno-filial. Estas condiciones fundamentan las “motivaciones”, asimismo diversas, que alegan para justificar la opción que han escogido. En segundo lugar, que su toma de decisiones está mediada por la existencia de una jerarquía socio-moral entre las distintas vías de acceso a la maternidad en solitario, cuyas posiciones más bajas están ocupadas por “el engaño” y “el donante conocido”, y la más elevada, por la adopción internacional. Se concluye subrayando la idea de que los enunciados de valor en que se basa dicha jerarquía socio-moral explican la pervivencia de la “motivación de la solidaridad” en el discurso de las MSPE adoptantes, a pesar de la deslegitimación de que es objeto por parte del conocimiento experto sobre el tema.

Reproducción tardía y tratamientos de fertilización: consecuencias bio-sanitarias

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Fuster Siebert, Vicente

2007-01-01

Full Text Available A partir de los años 60 se observó, coincidiendo con el desarrollo de técnicas de contracepción eficaces y con la incorporación femenina al mundo laboral, que en algunos países europeos con mayor nivel de bienestar, la edad a la que ocurría la primera maternidad se iba retrasando progresivamente. Es sabido que conforme la edad de la mujer aumenta, además de posibles efectos negativos sobre el recién nacido (bajo peso y prematuridad, su fecundidad disminuye debido, tanto a cambios en la frecuencia de relaciones sexuales, como a una menor fecundabilidad y a una mayor probabilidad de aborto. En ocasiones, se intenta resolver la dificultad de concebir mediante el recurso de técnicas de reproducción asistida. Cabe preguntarse si estas técnicas implican algún riesgo en cuanto a la mortalidad o morbilidad del niño. Diversos estudios han puesto en evidencia que aquellos concebidos por reproducción asistida, acumulan más del doble de defectos congénitos que los fecundados de forma natural. Otra consecuencia negativa es la aparición de gestaciones múltiples, las cuales se asocian con un menor peso al nacimiento y mayor incidencia de prematuros. Además, ya sea por una mayor probabilidad de anomalías congénitas o por otras causas (tales como el síndrome transfusional, las gestaciones múltiples resultan en una mayor frecuencia de pérdidas fetales tardías. Por lo que se refiere a la mortalidad perinatal, la mayoría de los estudios indican un riesgo superior relacionado con los tratamientos de reproducción asistida, debido principalmente, pero no exclusivamente, a la mayor incidencia de múltiples. De todo lo anterior, se concluye la necesidad de planificar el coste sanitario que puede suponer la atención de recién nacidos prematuros y de bajo peso, resultado de una edad de maternidad elevada asociada a tratamientos de reproducción asistida.

Radical fashion and radical fashion innovation

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Zhang, D.; Benedetto, Di A.C.

2010-01-01

This is a study of the related concepts of radical fashion and radical fashion innovation. Radical fashions are defined here as those that may never enter the market at all, and exist primarily on runway shows, in exhibitions and in publicity; by contrast, radical fashion innovations may be very

Planificación clásica en cirugía ortognática

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Joan Birbe

2014-07-01

Existe más de un enfoque correcto en la planificación y tratamiento de pacientes de cirugía ortognática. Cada paciente debe ser planificado y tratado de forma personalizada, según una serie de criterios. Existen pruebas adyuvantes como el escáner de haz de cono, planificación guiada por el escáner, férulas quirúrgicas CAD-CAM, modelos 3D craneales de resina o incluso cirugía con navegación asistida por robot que pueden ser útiles para mejorar los resultados quirúrgicos y disminuir el riesgo quirúrgico. Esto puede ser especialmente importante en deformidades severas, con un crecimiento anómalo y requiriendo maniobras quirúrgicas especialmente complicadas. Además, la cirugía endoscópica y la cirugía asistida por robot para navegar, están en rápido desarrollo y pueden en casos seleccionados especialmente complejos estar justificados. El objetivo de este artículo es discernir cuando son necesarias tales herramientas en cirugía ortognática.

The World Bank’s ‘Market-Assisted’ Land Reform as a Political Issue: Evidence from Brazil (1997-2006

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João Márcio Mendes Pereira

2007-04-01

Full Text Available The article analyses the political struggles that  occurred during the implementation of projects  and programmes in Brazil based on marketassisted land reform (MALR, which was conceived by the World Bank as an alternative to the  redistributive agrarian reform and carried out by  the state through expropriation of land. The article  places the MALR within the process of recycling  the neoliberal agenda – when the so-called ‘second generation’ of structural reforms was given a  boost – and within the extent of the World Bank’s  financial, political and/or intellectual actions  related to property issues, ownership and use of  the rural land. It then shows why, how, what for  and under which political support the MALR was  introduced in Brazil during the Cardoso government. The political struggle involving the implementation of the MALR is also analysed, detailing  the process of articulation and disarticulation of  the peasants’ organizations that opposed to the  World Bank’s proposal. After evaluating the  struggles occurring during the Cardoso government, the article explains how Lula’s first mandate continued to implement MALR, and presents  recent positions of the World Bank on the subject.Resumen: La reforma agraria ‘asistida por el mercado’  del Banco Mundial como cuestión política: evidencias desde Brasil (1997-2006 El artículo analiza las luchas políticas que tuvieron lugar durante la puesta en práctica de proyectos y programas basados en la reforma agraria  asistida por el mercado (MALR en Brasil, concebida por el Banco Mundial como alternativa a la  reforma agraria redistributiva, implementada por  el Estado mediante la expropiación de tierras. El  texto coloca el programa de reforma agraria asistida por el mercado dentro del proceso más amplio de reciclaje de la agenda neoliberal – cuando  estaba ganando impulso la llamada ‘segunda  generación’ de reformas estructurales – y

Factores de depresión y de autoestima en mujeres víctimas de violencia familiar asistidas en un Centro de Emergencia Mujer de la provincia de Huánuco

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Sobrado Chávez, Félix Dulio

2017-01-01

Investigación de tipo descriptiva comparativa correlacional tuvo como objetivo Establecer la relación y/o comparación entre los niveles de depresión y de autoestima que presentan las mujeres víctimas de violencia, asistidas en un centro emergencia mujer de la provincia de Huánuco según el tipo de familia, estado civil, ocupación y la edad. Se aplicaron las escalas de depresión de Beck y la escala de Coopersmith a una muestra de 140 mujeres entre 18 a 47 años de edad. Los datos fueron procesad...

Las madres solteras por elección. ¿Ciudadanas de primera y madres de segunda?

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Jociles, María Isabel

2011-03-01

Full Text Available This article lays out the results of a study of family projects on women who have opted for single motherhood through assisted reproduction, sexual relations and/or international adoption. The course of these speeches is analyzed on a tri-fold approach. First, the speeches show the conflict between these women’s status as full-fledged citizens, which has allowed them to successfully access university education and hold qualified positions, and their status as mothers that is still very much defined by the traditional model of the married, two-parent nuclear family, a model that continues to be the criteria for legitimizing all other family options. Secondly, the narrative strategies these women unfurl to gain social recognition in their respective family, work, friend and legal spheres are examined. Finally, these speeches permit to study the deficient perception of their family unit that many of these women end up assimilating as an unexpected side effect of their situation.

En este artículo se presentan algunos de los resultados de una investigación sobre los proyectos familiares de las mujeres que han optado por la maternidad en solitario, mediante la reproducción asistida, las relaciones sexuales y/o la adopción internacional. A través de sus discursos se analiza, en primer lugar, el conflicto entre su estatus de ciudadanas de pleno derecho, por el que han podido acceder, exitosamente, a la formación universitaria y al desempeño de empleos cualificados, y el estatus de madres aún condicionado por el modelo convencional de familia nuclear, conyugal y biparental, que sigue actuando como referente de legitimación para el resto de opciones familiares. En segundo lugar, se analizan las estrategias narrativas de legitimación que despliegan estas mujeres para obtener el reconocimiento social de su entorno familiar, labo ral, de los amigos, institucional y, por último, la percepción carencial de su familia que ellas mismas

Actividad biológica de los aceites esenciales de Acmella ciliata (Kunth) Cass

OpenAIRE

Rincón Mejía, Carlos Andrés; Castaño Osorio, Jhon Carlos; Ríos Vázquez, Eunice

2012-01-01

Introducción: Acmella ciliata (Kunth) Cass. es una arvense nativa del norte de Suramérica conocida por su contenido de alcamidas alifáticas, se usa popularmente como anestésico y analgésico contra los dolores de muelas y de garganta. Objetivos: obtener, analizar y evaluar la actividad biológica de los aceites esenciales de las flores y hojas de Acmella ciliata (Kunth) Cass. Métodos: se obtuvieron los aceites esenciales de Acmella ciliata por hidrodestilación e hidrodestilación asistida por mi...

Síntesis de silicatos de calcio por el método Pechini e intercambio iónico de alginato de sodio-cloruro de calcio

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Katya Aradeli Flores-Garay

2016-11-01

Full Text Available Se sintetizaron muestras de silicatos de calcio, a partir de diferentes concentraciones de tetraetilortosilicato (TEOS y mediante la metodología Pechini, asistida con intercambio iónico a base de alginato de sodio y cloruro de calcio, seguido de un tratamiento térmico a 800 °C por 2 h. Las muestras A, B y C, que se obtuvieron utilizando 1,7 × 10−3 M, 3,4 × 10−3 M y 5,1 × 10−3 M de TEOS, respectivamente, y sin tratamiento térmico, se caracterizaron por análisis termogravimétrico (TGA y espectroscopia infrarroja con reflectancia total atenuada (FTIR-ATR. Por otra parte, las muestras A800, B800 y C800, que se obtuvieron usando un tratamiento térmico a 800 °C por 2 h, se caracterizaron por FTIR-ATR, área superficial específica por la técnica de adsorción de gas nitrógeno (BET, difracción de rayos X (DRX y por microscopia electrónica de barrido. Por espectroscopia FTIR-ATR se confirmó la presencia de enlaces Si-O-Si, indicativos de la formación de silicatos y de sílice en las muestras A800, B800 y C800. Los difractogramas indican que la muestra A800 contiene olivino (Ca2SiO4 en fase ortorrómbica y wollastonite-2 M (CaSiO3; la muestra B800 presentó, además de las fases anteriores, cuarzo (SiO2 en fase hexagonal, mientras que la muestra C800, obtenida con una mayor cantidad de TEOS, presentó las fases de wollastonita-2 M y larnita (Ca2SiO4.

Análisis sociosemiótico de las estrategias discursivas de unión cívica radical en el debate legislativo de la ley 9182 de juicio por jurados

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Cintia Weckesser

2013-01-01

Full Text Available En este trabajo se analizan las estrategias discursivas de Unión Cívica Radical en la discusión legislativa que dio lugar a la Ley 9182 de juicio por jurados(Legislatura Unicameral de la Provincia de Córdoba, 2004b, en la provincia de Córdoba, Argentina. El estudio se enmarca en la articulación sociosemiótica pro-puesta por Mozejko y Costa (2001, 2007, 2010, que toma como punto de partida la pregunta por la relación entre los agentes sociales y sus prácticas discursivas. El interrogante que orienta el desarrollo de este artículo es por qué y cómo la UCR, habiendo sido en la historia reciente de Córdoba quien promovió transformaciones clave tanto en la Constitución de la provincia (Gobierno de la Provinciade Córdoba, 1987,como en su Código de Procesamiento Penal (Cámara de Senadores y Cámara de Diputados de la Provincia de Córdoba, 1991, las cuales in-trodujeron la participación ciudadana en la justicia; en el año 2004, a contramano, no acompañó el proyecto del ejecutivo provincial que amplió considerable-mente la participación de ciudadanos en la justicia penal. Por un lado, se analiza el modo en que se construye el lugar de la enunciación y en relación con ello, el pro-grama narrativo propuesto, en el cual legisladores, jueces y ciudadanos se presentan investidos de ciertos atributos y encomiendas. Luego, el análisis de las estrategias de UCR se articula con la construcción de este agente social, a fin de poner en consideración un doble supuesto: (a que los discursos tienen relación con el lugar desde el cual se los produce, y por lo tanto, son resultado de opciones realiza-das por el agente, condicionado por su competencia y por el escenario en el que despliega sus estrategias discursivas, y (b que la relación entre el lugar del agentey su discurso es de coherencia (Mozejko y Costa, 2001: 32 y ss.

Análisis sociosemiótico de las estrategias discursivas de unión cívica radical en el debate legislativo de la ley 9182 de juicio por jurados

Directory of Open Access Journals (Sweden)

Cintia Weckesser

2013-05-01

Full Text Available En este trabajo se analizan las estrategias discursivas de Unión Cívica Radical en la discusión legislativa que dio lugar a la Ley 9182 de juicio por jurados (Legislatura Unicameral de la Provincia de Córdoba, 2004b, en la provincia de Córdoba, Argentina. El estudio se enmarca en la articulación sociosemiótica propuesta por Mozejko y Costa (2001, 2007, 2010, que toma como punto de partida la pregunta por la relación entre los agentes sociales y sus prácticas discursivas. El interrogante que orienta el desarrollo de este artículo es por qué y cómo la UCR, habiendo sido en la historia reciente de Córdoba quien promovió transformaciones clave tanto en la Constitución de la provincia (Gobierno de la Provincia de Córdoba, 1987,como en su Código de Procesamiento Penal (Cámara de Senadores y Cámara de Diputados de la Provincia de Córdoba, 1991, las cuales introdujeron la participación ciudadana en la justicia; en el año 2004, a contramano, no acompañó el proyecto del ejecutivo provincial que amplió considerablemente la participación de ciudadanos en la justicia penal. Por un lado, se analiza el modo en que se construye el lugar de la enunciación y en relación con ello, el programa narrativo propuesto, en el cual legisladores, jueces y ciudadanos se presentan investidos de ciertos atributos y encomiendas. Luego, el análisis de las estrategias de UCR se articula con la construcción de este agente social, a fin de poner en consideración un doble supuesto: (a que los discursos tienen relación con el lugar desde el cual se los produce, y por lo tanto, son resultado de opciones realizadas por el agente, condicionado por su competencia y por el escenario en el que despliega sus estrategias discursivas, y (b que la relación entre el lugar del agente y su discurso es de coherencia (Mozejko y Costa, 2001: 32 y ss..

Control optimo de par para maquinas SynRM aplicadas a vehiculo electrico

OpenAIRE

Trancho, Elena; Ibarra, E.; Arias, A.; Kortabarria, I.

2017-01-01

Las maquinas de reluctancia sincrona asistidas por imanes estan atrayendo un considerable interes como alternativa a las maquinas sıncronas de imanes permanentes para su uso en sistemas de propulsion de vehıculos electricos. El control optimo de estas maquinas (incluyendo operacion en debilitamiento de campo) puede resultar complejo, ya que estas son, por lo general, muy sensibles al fenomeno de la saturacion magnetica. En este articulo se trata su control, desde los reguladores hasta el prec...

Ciudadanías sexo-genéricas y corporalidades. Un análisis de las leyes de fertilización asistida y reparación mamaria en Argentina

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Leila Martina Passerino

2015-06-01

Full Text Available El trabajo analiza dos leyes sancionadas recientemente en Argentina: la cobertura de los tratamientos de reproducción asistida a través de la Ley de Fertilización de la Provincia de Buenos Aires y la posterior Ley Nacional; y la Ley Nacional de Reconstrucción Mamaria a mujeres mastectomizadas. Desde una perspectiva biopolítica y a partir del concepto de ciudadanía sexual indagamos cómo estas legislaciones operan performativamente instituyendo cuerpos sexuados y genéricos. Se considera el rol paradójico del Estado que garantiza derechos y simultáneamente produce ciudadanías normadas respecto a ideales de familia, femineidad y de lo saludable.

Coatings of metal substrates assisted by laser radiation

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Caudevilla, H.

1998-04-01

Full Text Available In this contribution, a new way of obtaining ceramic coatings is presented. This method uses precursor suspensions, settled on substrates and in-situ pyrolised with a laser. Different deposition techniques of the ceramic precursors have been tested in order to obtain a homogeneous distribution on the metal substrate before the laser treatment.

La combinación de recubrimientos utilizando disoluciones de precursores metálicos con la pirólisis asistida por láser, permite obtener una gran diversidad de recubrimientos sobre sustratos de muy distinta naturaleza. Se han realizado estudios, tanto con disoluciones poliméricas, como con disoluciones de tipo sol-gel y pastas obtenidas con técnicas similares, depositadas utilizando métodos convencionales de inmersión y atomización previa a la pirólisis asistida por láser, así como simultánea. En este trabajo se presenta un resumen de los resultados más significativos obtenidos en la realización de recubrimientos sobre sustratos metálicos y cerámicos.

TEC promueve la matemática en la educación media

OpenAIRE

Guzmán O., Marcela

2017-01-01

Ofrecer capacitación de calidad para los docentes de matemática de colegios públicos ycolaborar en la organización de actividades que promuevan el interés por esa materia, sonlos dos objetivos principales del proyecto de extensión PROMATES (Promoción de laMatemática en la Educación Secundaria), que desarrollan académicos y estudiantes de la carrera de Enseñanza de la Matemática Asistida por Computadora del TEC.

Hydroxyl-radical-induced oxidation of cyclic dipeptides: Reactions of free peptide radicals and their peroxyl radicals

International Nuclear Information System (INIS)

Mieden, O.J.

1989-01-01

In the course of this study investigations were carried out into the reactions of hydroxyl radicals and hydrogen atoms with cyclic dipeptides as well as the subsequent reactions of peptide radicals and their peroxyl radicals in aqueous solution. The radiolysis products formed in the absence and presence of oxygen or transient metal complexes were characterized and determined on a quantitative basis. The linking of information from product analyses to the kinetic data for transient species obtained by time-resolving UV/VIS and conductivity measurements (pulse radiolysis) as well as computer-assisted simulations of individual events during the reaction permitted an evaluation of the mechanisms underlying the various processes and an identification of interim products with short life-times, which did or did not belong to the group of radicals. Through the characterization of key reactions of radicals and peroxyl radicals of this substance class a major advance has been made towards a better understanding of the role of radicals in the peptide compound and the mechanisms involved in indirect radiation effects on long-chain peptides and proteins. (orig.) [de

A radical approach to radical innovation

NARCIS (Netherlands)

D. Deichmann (Dirk); J.C.M. van den Ende (Jan)

2014-01-01

textabstractInnovation pays. Amazon, Apple, Facebook, Google – nearly every one of today’s most successful companies has a talent for developing radical new ideas. But how best to encourage radical initiative taking from employees, and does their previous success or failure at it play a role?

Radicalization In Pakistan And The Spread Of Radical Islam In Pakistan

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Bahir ahmad

2015-08-01

Full Text Available ABSTRACT It is pertinent to mention that radicalism is not intrinsic to Islam and radical interpretations of the religion or for that matter may occur within any way of life and religion Saikal 2003 and yet the question remains as to why Muslims in certain geographical regions have more radical approaches towards their religion and also that what are the causes of such radicalization. Becoming a radical Muslim is not even a matter of a day nor is it a sudden process. There are several reasons behind making a person radical peaceful angry smiling or tolerant. For knowing the reason behind radicalization or radicals persons one has to understand the causes. Tracing these causes is one of the ways to eliminate such behavior. The first step in the elimination of the radical sentiments in a person is to develop peace in his personality Fair Malhotra amp Shapiro 2010. The chapter which has been addressed here is going to shed light on the roots and symptoms of the radicalism. There will be a brief discussion on how the roots of radicalism can be traced and can be eliminated. The assessment and discussion will be conducted on the parameters of the economy media politics and theology from social cultural point of view. According to the analysis of Ahrari 2000 political factor is one of the major and direct factors which have resulted in causing of the radicalism. These factors however intertwine with one another. Radical actions cannot take place only because of the political factors.

Jorge Isaacs: El espíritu radical de un poeta y sus frustraciones políticas

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Raúl Vallejo Corral

2015-02-01

Full Text Available Jorge Isaacs es conocido por María (1867, novela cumbre del romanticismo americano. Pero Isaacs, además, fue un político liberal radical que llevó adelante una revolución, en enero de 1880, movido por sus principios ideológicos en medio de lo que él consideraba la traición de los liberales. La revolución, embebida de romanticismo, fue una empresa romántica destinada al fracaso desde un principio. Este artículo, a partir del estudio de los documentos de la época, analiza de qué manera Isaacs desarrolló sus actividades militantes, como superintendente de Educación, primero, como congresista, después, y como revolucionario, en el marco del proceso de recuperación del poder por parte de los conservadores. Asimismo, este artículo se enfoca en el espíritu romántico que animó a Isaacs y cómo se expresó a través de la palabra encendida de los manifiestos, proclamas, cartas e informes recopilados por el propio Isaacs en su libro La revolución radical en Antioquia (1880.   Jorge Isaacs is well-known for Maria (1867, which is considered the most important novel of Latin American romanticism. But Isaacs was also a radical liberal politician who carried forward a revolution, in January 1880, moved by his ideological principles in the midst of what he considered to be the treason of the liberals. From the very beginning, this revolution, which was immersed in romanticism, was an enterprise destined to fail. This article, based on the study of documents from that time, analyzes the way in which Isaacs developed his militant activities firstly as an Education inspector, then as a congressman, and finally as a revolutionary in the framework of the recovery process by the conservative party. Likewise, this article focuses on the romantic spirit that inspired Isaacs and how he expressed himself through his passionate words present in manifestos, proclamations, letters, and reports compiled by Isaacs himself in The Radical Revolution in

Cerámicas y sistemas para restauraciones CAD-CAM: una revisión

OpenAIRE

Caparroso Pérez, Carlos; Duque Vargas, Jaiver Andrés

2010-01-01

En la actualidad disponemos de muchos sistemas para hacer de restauraciones indirectas libres de metal, el de mayor actualidad y uso es el denominado CAD-CAM, cuyo diseño y elaboración son asistidas por un computador. Para la elaboración de una restauración por este método se deben seguir tres fases: digitalización de la preparación dental obtenida por medio de un escáner, diseño de la restauración lograda mediante de un programa de computador y maquinado de un bloque cerámico del cual se obt...

Determinación de los niveles de plomo y cadmio en leche procesada en la ciudad de Bogotá D.C.

OpenAIRE

Pinzon Choque, Carlos Giovanni

2015-01-01

La leche y los productos lácteos han sido reconocidos en todo el mundo por su influencia beneficiosa sobre la salud humana. Los niveles de metales en concentraciones tóxicas son un componente importante de la seguridad y la calidad de la leche. Se desarrolló un método sencillo de extracción (digestión) asistida por microondas para la determinación posterior de los niveles de cadmio (Cd) y plomo (Pb) en leche líquida por espectrofotometría de absorción atómica (AAE) con horno de grafito. Se ap...

El peso corporal y su influencia en la infertilidad femenina

OpenAIRE

Alonso Pérez, Andrea

2017-01-01

Las técnicas de reproducción asistida humana son cada vez más frecuentes debido al crecimiento de la tasa de infertilidad en nuestra sociedad. Una de las causas de este aumento en los problemas de fertilidad se debe a la adopción de malos hábitos de vida, incrementando así el número de personas con malnutrición, ya sea por exceso en el caso de la obesidad o por defecto en el caso de la anorexia. Tanto el sobrepeso o la obesidad como un peso por debajo de lo debido, tiene repercusiones en e...

Sistema de enseñanza/aprendizaje inteligente para grafos

OpenAIRE

Martínez, Natalia; Ferreira, Gheisa; García, Zoila Zenaida

2007-01-01

La teoría de grafos es un tema de estudio de la Matemática Discreta que por su importancia está presente en asignaturas de la carrera Ciencia de la Computación. Dificultades presentadas con respecto a su aprendizaje, han conducido al diseño e implementación de un Sistema de Enseñanza/Aprendizaje Inteligente (SEAI) que aborde esta temática. Los SEAI se caracterizan por aplicar técnicas de Inteligencia Artificial (IA) al desarrollo de sistemas de enseñanza asistida por computadoras, donde el té...

Synthesis of fused azole-piperidionoses: A free radical cyclization approach

Energy Technology Data Exchange (ETDEWEB)

Marco-Contelles, Jose; Alhambra Jimenez, Carolina [Instituto de Quimica Organica General (CSIC), Madrid (Spain)

1999-08-01

A new strategy has been reported for the synthesis of fused azole-piperidinoses featuring and unprecedented and very efficient 6-exo-trig free radical cyclization onto heterocyclic sugar templates. These compounds are key intermediates for the synthesis of known or analogues of azole-glycosidase inhibitors. In this communication we describe our recent and successful results on the synthesis of fused triazole-piperidinoses. Radical precursors have been prepared by standard methodologies from 1, 2:5, 6-bis-O-isopropylidene-{alpha}-D-glucofuranose (4) via triazoles linked at C3 with {beta}-orientation, readily obtained by 1, 3-dipolar cycloaddition of azide 5 with diethyl acetylenedicarboxylate or methyl propiolate, and by S{sub N}2 displacement of the tosylate at C3 with 1, 2, 4-triazole in compound 20. The key 6-exp-trig free radical cyclizations proceeded in the usual conditions [tributyltin hydride or tris(trimethylsily)silane, AIBN, toluene] yielding the azaannulated sugars 9, 11, 19 and 23 in good or excellent yields. A mechanism for these cyclizations has been proposed. [Spanish] Se ha informado una nueva estrategia para la sintesis azol-piperidinosas fusionadas mediante una ciclizacion 6-exo-trig muy eficiente y sin precedentes, sobre plantillas de azucares heterociclicos. Estos compuestos son intermediarios claves para la sintesis de inhibidores de azol-glicosidasa conocidos analogos de ellos. En esta comunicacion describimos nuestros resultados recientes y exitosos sobre la sintesis de triazol-piperidinosas. Los precursores de radicales fueron preparados por la metodologia usual a partir de 1, 2:5, 6-bis-O-isopropiliden-{alpha}-D-glucofuranosa (4) via triazoles unidos en C3, con orientacion {beta}, los cuales se obtienen facilmente por cicloadicion 1, 3-dipolar de la azida 5 con acetilendicarboxilato de dietilo o propiolato de metilo y por desplazamiento S{sub N}2 del tosilato en C3 con 1, 2, 4-triazol en el compuesto 20. Las ciclizaciones 6-exo

Manipulating radicals: Using cobalt to steer radical reactions

OpenAIRE

Chirilă, A.

2017-01-01

This thesis describes research aimed at understanding and exploiting metallo-radical reactivity and explores reactions mediated by square planar, low-spin cobalt(II) complexes. A primary goal was to uncover novel reactivity of discrete cobalt(III)-bound carbene radicals generated upon reaction of the cobalt(II) catalysts with carbene precursors. Another important goal was to replace cobalt(II)-porphyrin catalysts with cheaper and easier to prepare metallo-radical analogues. Therefore the cata...

Factores que predisponen, facilitan y refuerzan el uso del preservativo en jóvenes universitarios de cali, colombia

OpenAIRE

Valencia, Claudia Patricia

2013-01-01

Objetivos Identificar la frecuencia del uso habitual del condón y los factores que predicen, facilitan y refuerzan su uso en jóvenes universitarios. Métodos Estudio analítico de corte transversal con análisis multivariado. La muestra fue de 397 estudiantes seleccionados aleatoriamente mediante un muestreo estratificado por Facultades a quienes se les aplicó una encuesta asistida por computador denominada “Reconociendo mi salud sexual”. Resultados El uso habitual de condón se da para el 33 % d...

Free radical inactivation of trypsin

International Nuclear Information System (INIS)

Cudina, Ivana; Jovanovic, S.V.

1988-01-01

Reactivities of free radical oxidants, radical OH, Br2-anion radical and Cl 3 COO radical and a reductant, CO2-anion radical, with trypsin and reactive protein components were determined by pulse radiolysis of aqueous solutions at pH 7, 20 0 C. Highly reactive free radicals, radical OH, Br2-anion radical and CO2-anion radical, react with trypsin at diffusion controlled rates. Moderately reactive trichloroperoxy radical, k(Cl 3 COO radical + trypsin) preferentially oxidizes histidine residues. The efficiency of inactivation of trypsin by free radicals is inversely proportional to their reactivity. The yields of inactivation of trypsin by radical OH, Br2-anion radical and CO2-anion radical are low, G(inactivation) = 0.6-0.8, which corresponds to ∼ 10% of the initially produced radicals. In contrast, Cl 3 COO radical inactivates trypsin with ∼ 50% efficiency, i.e. G(inactivation) = 3.2. (author)

Semen, óvulos y úteros nómadas. Representaciones sobre mujer, maternidad y nuevas técnicas de reproducción asistida

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Mercedes de Grado González

2012-04-01

Full Text Available A pesar de los cambios políticos, socio-económicos y demográficos habidos en los países occidentales en las últimas décadas, las estructuras simbólicas y los imaginarios colectivos en torno a las mujeres, su función social y la maternidad no han cambiado tanto. El orden patriarcal hoy en Occidente se configura como un patriarcado de consentimiento. En dicha estructura social la retórica ideológica representa la maternidad como una elección. Sin embargo, a través de los universos simbólicos que ofrecen los medios de comunicación de masas, la maternidad sigue perfilándose como un mandato imperativo para la construcción de la identidad femenina. En este estudio vamos a tomar como ejemplo la película Madre de alquiler, representación fílmica sobre la maternidad y las técnicas de reproducción asistida que refrenda el mandato patriarcal de la maternidad.

Endoscopic ultrasound-assisted endoscopic resection of carcinoid tumors of the gastrointestinal tract Resección endoscópica asistida por ecoendoscopia de tumores carcinoides del aparato digestivo

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D. Martínez-Ares

2004-12-01

endoscópicamente 24 tumores en 21 pacientes (edad media de 51,7 años; 71,5% varones. Las lesiones eran en su mayoría hallazgos incidentales en exploraciones indicadas por otros motivos. La resección se indicó en la mayoría de los casos por sospecha ecoendoscópica de tumor carcinoide. La ecoendoscopia además permitió establecer con claridad la capa de origen de la lesión y el tamaño de la misma. La extirpación se llevó a cabo en 13 casos (54,2% mediante la técnica convencional de polipectomía con asa, en 9 casos (37,5% asistida con inyección submucosa de suero salino y/o adrenalina y en 2 casos (8,3% tras ligar la lesión con bandas elásticas. En todos los casos la resección fue completa, sin recidivas durante el seguimiento. En un único caso se produjo una complicación mayor: una hemorragia postpolipectomía que se controló endoscópicamente. Conclusiones: la resección endoscópica de los tumores carcinoides, en pacientes bien seleccionados, es una técnica segura y eficaz permitiendo una resección completa en todos los casos con escasas complicaciones. La ecoendoscopia es la técnica de elección para seleccionar los pacientes candidatos a resección endoscópica.

Desarrollo de una metodología no invasiva basada en espectroscopía infrarroja, para la detección del potencial reproductivo de embriones previo a su transferencia en tratamientos de fertilización asistida

OpenAIRE

Fígoli, Cecilia Beatriz

2017-01-01

Entre los mayores desafíos de la investigación actual en Fertilización Asistida se encuentran el mejoramiento de la tasa de embarazo y la disminución de los embarazos múltiples. La gran dificultad que existe para estimar el potencial de implantación embrionaria lleva en la práctica a implementar la transferencia de más de un embrión. Desarrollar un nuevo método que incremente la eficacia de la selección embrionaria permitiría aumentar la tasa de embarazo disminuyendo embarazos múlti...

Conversion of alkyl radicals to allyl radicals in irradiated single crystal mats of polyethylene

International Nuclear Information System (INIS)

Fujimura, T.; Hayakawa, N.; Kuriyama, I.

1978-01-01

The decay of alkyl radicals, the conversion of alkyl radicals to allyl radicals and the trapping of allyl radicals in irradiated single crystal mats of polyethylene have been studied by electron spin resonance (e.s.r.). It has been suggested that in the crystal core alkyl radicals react with trans-vinylene double bonds and are converted into trans-vinylene allyl radicals; at the crystal surface, alkyl radicals react with vinyl end groups and are converted into allyl radicals with vinyl end groups. The decay of radical pairs and the formation of trans-vinylene double bonds are discussed. (author)

Darwin por Manoel Bomfim Darwin by Manoel Bomfim

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Celso Noboru Uemori

2008-01-01

Full Text Available A noção de "luta pela existência" de Charles Darwin foi apropriada por diversas tendências intelectuais e serviu a vários propósitos políticos. Ela deu suporte para aqueles que queriam legitimar o capitalismo, fazer apologia do individualismo, do mercado, do fim dos monopólios e da competição. Ensejou concepções conservadoras como a prática da eugenia, a justificação do elitismo, da conquista e da colonização dos europeus sobre as populações asiáticas e africanas e o racismo. A idéia de luta pela existência foi trabalhada, também, por intelectuais que defendiam a idéia de que lutar pela vida relacionava-se à solidariedade e à cooperação. Manoel Bomfim sofreu influência de Darwin e beneficiou-se de suas idéias para elaborar argumentos, graças aos quais foi visto por seus intérpretes como um autor "radical" e original.Charles Darwin's notion of a 'struggle for existence' has been appropriated by several intellectual currents of opinion, and used for various political purposes. It has served to support free market capitalism, as an apologia of individualism, the market, the end of monopolies, and competition. Conservative conceptions have been based on it: the practice of eugenics, the justification of elitism, of the conquest and colonization of Asian and African peoples by the European, and of racism. On the other hand, the idea of a struggle for existence has been worked on by intellectuals who argued that it was related to solidarity and cooperation. Manoel Bomfim was influenced by Darwin and used his ideas to form arguments which have led his interpreters to see him as a 'radical' and original author.

Guest Editorial: Processes of Radicalization and De-Radicalization

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Donatella Della Porta

2012-05-01

Full Text Available The study of radicalization and de-radicalization, understood as processes leading towards the increased or decreased use of political violence, is central to the question of how political violence emerges, how it can be prevented, and how it can be contained. The focus section of this issue of the International Journal of Conflict and Violence addresses radicalization and de-radicalization, seeking to develop a more comprehensive understanding of the processes, dynamics, and mechanisms involved and taking an interdisciplinary approach to overcome the fragmentation into separate disciplines and focus areas. Contributions by Pénélope Larzillière, Felix Heiduk, Bill Kissane, Hank Johnston, Christian Davenport and Cyanne Loyle, Veronique Dudouet, and Lasse Lindekilde address repressive settings, legitimacy, institutional aspects, organizational outcomes, and dynamics in Europe, Asia, Africa, and North and South America.

Metal-catalyzed living radical polymerization and radical polyaddition for precision polymer synthesis

Energy Technology Data Exchange (ETDEWEB)

Mizutani, M; Satoh, K [Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Kamigaito, M, E-mail: kamigait@apchem.nagoya-u.ac.j

2009-08-01

The metal-catalyzed radical addition reaction can be evolved into two different polymerization mechanisms, i.e.; chain- and step-growth polymerizations, while both the polymerizations are based on the same metal-catalyzed radical formation reaction. The former is a widely employed metal-catalyzed living radical polymerization or atom transfer radical polymerization of common vinyl monomers, and the latter is a novel metal-catalyzed radical polyaddition of designed monomer with an unconjugated C=C double bond and a reactive C-Cl bond in one molecule. The simultaneous ruthenium-catalyzed living radical polymerization of methyl acrylate and radical polyaddition of 3-butenyl 2-chloropropionate was achieved with Ru(Cp*)Cl(PPh{sub 3}){sub 2} to afford the controlled polymers, in which the homopolymer segments with the controlled chain length were connected by the ester linkage.

Diagnóstico genético preimplantacional: análisis de aneuploidías únicas

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Paul W. López

2013-01-01

Full Text Available Introducción: De las causas más conocidas en cuanto a la falta del éxito en el embarazo con tratamientos de reproducción asistida son aquellas relacionadas a las aneuploidías cromosómicas presentes en los embriones. El diagnóstico genético preimplantacional (PGD es una técnica empleada en reproducción asistida para detectar estas anomalías, seleccionando aquellos que sean cromosómicamente normales, para luego transferirlos al útero de la paciente. Los embriones con aneuploidías únicas podrían tener la capacidad de sobrevivir y lograr la implantación, y por lo tanto, sin diagnóstico previo, estas podrían pasar desapercibidas. Objetivos: Determinar la incidencia de aneuploidías únicas en embriones de buena calidad embrionaria en el día 3 de desarrollo hasta blastocisto. Diseño: Estadístico y experimental. Instituciones: Reprogenetics Latinoamérica y Centro de Reproducción asistida, de la Clínica Concebir. Material Biológico: Muestras de biopsia embrionaria. Metodología: Análisis comparativo de resultados a partir de la evaluación de cada muestra obtenida por biopsia en el día tercero y día quinto de desarrollo embrionario, realizando el PGD por hibridación in situ (FISH y genómica comparada (aCGH, respectivamente. Resultados: El 62,9% de embriones que presentaron monosomías únicas al tercer día de desarrollo embrionario resultaron ser de 8 células. Pero cuando se evaluó por aCGH en día cinco, 42,3% resultó anormal, y de estos 37,5% perteneció al estadio de 8 células. El índice de monosomías únicas en blastocisto resultó ser 57,9% de un total de 84,2% de aneuploidías únicas. Conclusiones: Los embriones de 8 células en el tercer día de desarrollo embrionario son los más probables de llegar al estadio de blastocisto, así como presentar aneuploidías únicas.

Gestación por Sustitución y Licencias por Maternidad/Paternidad. La Agenda de Cuidado a la Luz de la Jurisprudencia Española y la Perspectiva Argentina (Surrogate Motherhood and Maternity / Paternity Leave. The Care Agenda in the Light of the Spanish...

Directory of Open Access Journals (Sweden)

Agustina Perez

2017-03-01

Full Text Available This paper aims to analyze the new technologies and the ability to access a (coMaternity / (coFatherhood through assisted reproductive technics (ART, including surrogate motherhood, altogether with the issue of the care work and maternity/paternity leave. Therefore, this article aims no to stop in the arguments for and against surrogate motherhood (SM, but to reflect about how maternity / paternity leaves must be interpreted in these cases. For that purpose, the article analyzes Argentinian SM and parental leave legal situation in the light of recent Spanish jurisprudence that have authorized maternity / paternity leave in cases of children born by SM while, while considering gender issues involved in this situations, how is the use of time in each family, how both ART and care work have a differential impact on women, and what happens when it comes to families consisting of two male parents. El presente artículo busca analizar la posibilidad de acceder a una (comaternidad / (copaternidad mediante técnicas de reproducción humana asistida (TRHA, incluida la gestación por sustitución (GS, en conjunto con la problemática de la agenda de cuidado y las licencias por maternidad/paternidad, partiendo del hecho cierto de la GS se realiza, sin detenerse en los argumentos a favor y en contra de ella. Así, revisa el marco normativo argentino en relación a la GS y las licencias por maternidad/paternidad a la luz de la reciente jurisprudencia española que ha otorgado y rechazado licencias en casos en que se tuvo hijos/as mediante la GS, teniendo en cuenta teniendo en cuenta la perspectiva de género, cómo es el uso del tiempo en cada familia, cómo las TRHA y el cuidado impactan diferencialmente sobre la mujer y cómo se traduce esta situación cuando se trata de familias compuestas por dos padres varones. DOWNLOAD THIS PAPER FROM SSRN: http://ssrn.com/abstract=2779614

Radical Change by Entrepreneurial Design

National Research Council Canada - National Science Library

Roberts, Nancy C

1998-01-01

.... How radical change in public policy has occurred in the past is then documented. We find examples of radical change by chance, radical change by consensus, radical change by learning, and radical change by entrepreneurial design...

SKINNER, POPPER E O SUPOSTO ESTATUTO DETERMINISTA DO COMPORTAMENTALISMO RADICAL

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César Antonio Alves da Rocha

2015-07-01

Full Text Available A relação entre Comportamentalismo Radical edeterminismo é anunciada por Skinner e diversos comentadores desua obra. Contudo, há alguns autores que questionam essa relação,defendendo que a ciência do comportamento skinneriana estariamais próxima do indeterminismo. Dado tal dissenso, este trabalhocotejou a suposta compatibilidade entre o ComportamentalismoRadical de B. F. Skinner com as definições de determinismo eindeterminismo científicos apresentadas pelo filósofo da ciência KarlPopper. Primeiramente, são descritas as definições e os argumentosde Popper. Em seguida, são examinados excertos da obra de Skinnerrelacionados ao assunto. Os resultados sugerem não só que háelementos do discurso skinneriano incompatíveis com o que Popperclassifica como determinismo científico, como também que hámomentos em que as proposições de Skinner coincidem com o quePopper conceitua como indeterminismo científico.

Acuerdos Científicos Comparados entre Investigadores de Ciencias Sociales y Naturales Categorizados del PRONII 2011/13 de Paraguay

Directory of Open Access Journals (Sweden)

Norma Coppari

2017-01-01

Full Text Available Se presenta un estudiosobre los acuerdos científicos a los que adhieren los investigadores naturales y sociales paraguayos, en el que participan 183 cientificos categorizados por el PRONII/CONACYT de Paraguay en sus convocatorias de 2011, n1=251, y 2013, n2=347. Se aplicó una encuesta con recordación asistida sobre 4 reglas o acuerdos. El diseño es descriptivo, de corte transversal, con análisis cuantitativo. El 82% de la muestra reconoce acuerdos científicos, 8% no los admite y 10% duda de su existencia. Al solicitar que mencionen dichos acuerdos, 77% nombra al menos uno, 5% no los recuerda y 18% niega su existencia. Con la técnica de recordación asistida, 85% reconoce la inteligibilidad del mundo, 96% la actitud crítica, 95% la aptitud metodológica y la comunicación abierta.

The games radicals play : special issue on free radicals and radical ions

OpenAIRE

Walton, J.C.; Williams, F.

2015-01-01

Chemistry and Physics have aptly been described as “most excellent children of Intellect and Art” [1]. Both these “children” engage with many playthings, and molecules rank as one of their first favorites, especially radicals, which are amongst the most lively and exciting. Checking out radicals dancing to the music of entropy round their potential energy ballrooms is surely both entertaining and enlightening. Radicals’ old favorite convolutions are noteworthy, but the new styles, modes and a...

Time resolved resonance Raman spectra of anilino radical and aniline radical cation

International Nuclear Information System (INIS)

Tripathi, G.N.R.; Schuler, R.H.

1987-01-01

We report, in this paper, submicrosecond time resolved resonance Raman spectra of anilino radical and its radical cation as observed in pulse radiolytic studies of the oxidation of aniline in aqueous solution. By excitation in resonance with the broad and weak electronic transition of anilino radical at 400 nm (ε--1250 M -1 cm -1 ) we have observed, for the first time, the vibrational features of this radical. The Wilson ν 8 /sub a/ ring stretching mode at 1560 cm -1 is most strongly resonance enhanced. The ν 7 /sub a/ CN stretching band at 1505 cm -1 , which is shifted to higher frequency by 231 cm -1 with respect to aniline, is also prominent. The frequency of this latter mode indicates that the CN bond in the radical has considerable double bond character. The Raman spectrum of aniline radical cation, excited in resonance with the --425 nm electronic absorption (ε--4000 M -1 cm -1 ), shows features which are similar to phenoxyl radical. Most of the observed frequencies of this radical in solution are in good agreement with vibrational energies determined by recent laser photoelectron spectroscopic studies in the vapor phase. The bands most strongly enhanced in the resonance Raman spectrum are, however, weak in the photoelectron spectrum. While the vibrational frequencies observed for anilino radical and its isoelectronic cation are quite similar, the resonance enhancement patterns are very different. In particular the ν 14 b 2 mode of anilino radical observed at 1324 cm -1 is highly resonance enhanced because of strong vibronic coupling between the 400 nm 2 A 2 -- 2 B 1 and the higher 2 B 1 -- 2 B 1 electronic transitions

Validación por expertos del programa Trufas de Educación Asistida con Perros para la prevención del acoso escolar

OpenAIRE

Peña Gil, Diana

2016-01-01

La orientación educativa tiene entre sus objetivos el desarrollo personal del alumnado, la mejora de las relaciones e interacciones sociales, y el incremento de su equilibrio personal; mientras que a su vez la legislación educativa española mantiene como uno de sus principios fundamentales la prevención. Es por ello que, dentro de la acción tutorial deben asegurarse programas de intervención que favorezcan la prevención del acoso escolar, uno de las mayores problemáticas en los centros educat...

Intramolecular transformation of thiyl radicals to α-aminoalkyl radicals: 'ab initio' calculations on homocystein

International Nuclear Information System (INIS)

Chhun, S.; Berges, J.; Bleton, V.; Abedinzadeh, Z.

2000-01-01

One-electron oxidation of thiols by oxidizing radicals leads to the formation of thiyl radical and carbon-centered radicals. It has been shown experimentally that in the absence of oxygen, the thiyl radicals derived from certain thiols of biological interest such as glutathion, cysteine and homocysteine decay rapidly by intramolecular rearrangement reactions into the carbon-centered radical. In the present work we have investigated theoretically the structure and the stability of thiyl and carbon-centered radicals of homocysteine in order to check the possibility of this rearrangement. (author)

Free radical transfer in polymers

International Nuclear Information System (INIS)

Sonntag, C. von; Bothe, E.; Ulanski, P.

1998-01-01

For the present study of free-radical transfer in polymers pulse radiolysis and product studies have been carried out in aqueous solutions using thus far only the water-soluble polymers polyacrylic acid, polymethacrylic acid and polyvinyl alcohol. When OH radicals, generated in the radiolysis of N 2 O-saturated aqueous solutions, react with polymers the lifetime of the polymer radical thus created very much depends on the number of radicals per polymer chain. When there are a large number of radicals per chain their bimolecular decay may be faster than the corresponding (diffusion controlled) decay of monomeric radicals, but when the macromolecule contains only few or even just one radical their lifetime is considerably prolonged. Highly charged polymers such as polyacrylic acid at high pH attain a rod-like conformation which again favors a long lifetime of the radicals. Under such conditions, radical transfer reactions can occur. For example, in polyacrylic acid OH radicals generate two kinds of radicals side by side. The radical in β-position to the carboxylate group converts into the thermodynamically more stable α-radicals by an H-transfer reaction as can be followed by spectrophotometry. Besides radical transfer reactions β-fragmentation reactions occur causing chain scission. Such reactions can be followed in a pulse radiolysis experiment by conductometry, because counter ions are released upon chain scission. Such a process is especially effective in the case of polymethacrylic acid, where it results in a chain depolymerization. An intramolecular H-abstraction is also observed in the γ-radiolysis of polyacrylic acid with the corresponding peroxyl radicals. This causes a chain reaction to occur. The resulting hydroperoxides are unstable and decarboxylate given rise to acetylacetone-like products. In polyvinyl alcohol the peroxyl radicals in α-position to the alcohol function undergo HO 2 -elimination. This prevents a scission of the polymer chain in the

Estudio del desarrollo radical en almácigo de híbridos f1 de café obtenidos por cultivo de tejidos

Directory of Open Access Journals (Sweden)

Fabián Echeverría

2014-01-01

Full Text Available Plántulas de Híbridos F1 de café, obte - nidas por embriogénesis somática indirecta, fueron aclimatizadas bajo condiciones de inver - nadero, en 2 tipos de contenedores: bandeja con sustrato convencional y malla biodegradable con turba comprimida (Jiffy®. A los 2 meses, las plántulas fueron transferidas a bolsa con sus - trato convencional y desarrolladas en el vivero. Se evaluó el desarrollo y calidad de la planta 8 meses después de su crecimiento en almácigo. Se encontró 33% de raíces rectas y 65% con morfologías anormales como estrangulamien - tos, serpenteadas y bifurcaciones, las cuales tuvieron respectivamente menores valores en los parámetros de largo, grosor y peso, tanto en el sistema radical como aéreo. En cuanto al tipo de contenedor, se obtuvo mayor crecimiento en las plántulas desarrolladas en Jiffy® con res - pecto a las de bandejas, sin embargo, aquellas que preservaron la envoltura durante la etapa de vivero, tuvieron menor crecimiento y desarrollo, con respecto de aquellas que les fue retirado. Se recomienda retirar la cobertura del Jiffy® previo a la siembra en bolsa, así como mejorar la técnica de inmersión temporal para evitar anormalidades morfológicas en los embriones producidos.

Terapia de presión negativa como alternativa en el manejo de la infección en cirugía de columna

Directory of Open Access Journals (Sweden)

Alberto Aceves Pérez

2013-12-01

Full Text Available Describir las indicaciones y contraindicaciones de la terapia de cicatrización asistida por presión negativa. Se realiza una revisión de la bibliografía existente en las bases de datos de OVID, PubMed, Cochrane y Medigraphic en relación a la terapia de cicatrización asistida por presión negativa. Es un sistema de cicatrización no invasivo y activo que utiliza presión negativa localizada y controlada, que consta de un apósito especializado que incluye esponja reticulada que lleva a través de un tubo el exudado a un contenedor hermético. Este conjunto forma micro deformaciones en el lecho de la herida, que han demostrado ser causa importante de mayor migración fibroblástica y por consiguiente de tejido de mayor calidad, formación de tejido de granulación y angiogénesis. En relación con la infección, el principal enfoque del tratamiento es drenar todo el material purulento, quitar los desechos, el tejido desvitalizado, los cuerpos extraños y eliminar la etiología de la infección. Las indicaciones de la TPN son: heridas agudas, crónicas, por trauma, quemaduras, úlceras por diabetes o por decúbito y abdomen abierto y se contraindica en heridas con tejido necrótico, osteomielitis no tratada, fístulas no exploradas no entéricas y no se recomienda su colocación en áreas de malignidad. Este método es eficaz para el tratamiento de las infecciones post quirúrgicas profundas de la columna vertebral, utilizándose en promedio de 1 a 4 semanas.

Sarcoma de Kaposi en una paciente de Santo Tomé y Príncipe

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Melba Elers Bandera

2013-10-01

Full Text Available Se presenta el caso clínico de una paciente que fue asistida en el Hospital General "Dr. Ayres Menezes" de la República Democrática de Santo Tomé y Príncipe, por presentar fiebre y lesiones en la piel, a la cual se le diagnosticó sarcoma de Kaposi asociado a la infección por el virus de inmunodeficiencia humana/sida. La evolución tórpida y el estadio tan avanzado de la enfermedad, así como la resistencia a los fármacos antirretrovirales, ocasionaron la muerte de la fémina

Actualización en los tratamientos alternativos en el síndrome de dolor-disfunción craneomandibular

OpenAIRE

Brescó Salinas, Vicente Miguel; Méndez Blanco, Víctor Manuel; Vázquez Delgado, Eduardo; Gay Escoda, Cosme

1997-01-01

Realizamos una revisión bibliográfica sobre los diferentes tipos de tratamiento alternativo en aquellos casos en los que fracasa la terapia convencional en el síndrome de dolor-disfunción craneomandibular y en los cuales la cirugía no sea la terapia de elección; haciendo una clasificación actualizada de los mismos, siendo estos: terapia psíquica (terapia de relajación muscular y control y manejo del estrés), terapia física realizada por el propio paciente y asistida por un fisioterapeuta, ter...

La maternidad de alquiler frente a la summa divisio iuris entre las personas y las cosas

OpenAIRE

Montero, E. (Etienne)

2015-01-01

La legalización de la gestación por subrogación está en la agenda política de muchos países europeos. Puede parecer difícil no admitirla en el ordenamiento jurídico, ya que se apoya en las técnicas de procreación humana asistida que, en bastantes países, han sido reconocidas y reguladas. Este trabajo se propone identificar los problemas específicos planteados por la maternidad de alquiler. Desde un enfoque principalmente jurídico, se cuestiona esta práctica tanto en lo que respecta a la madre...

La posibilidad de inscribir en el Registro civil español a los nacidos en el extranjero, de una madre de alquiler

OpenAIRE

Barrón Arniches, Paloma de

2009-01-01

Ya es posible inscribir en el Registro Civil español a los hijos “naturales” de un matrimonio homosexual, nacidos en el extranjero mediante gestación por sustitución. Y ello a pesar de que el artículo 10.1 de la vigente ley española sobre técnicas de reproducción humana asistida declara la nulidad de pleno derecho de los contratos de renuncia a la filiación materna, y ordena con carácter imperativo que en estos supuestos la filiación de los nacidos se determine por el parto. El...

Glutathione--hydroxyl radical interaction: a theoretical study on radical recognition process.

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Béla Fiser

Full Text Available Non-reactive, comparative (2 × 1.2 μs molecular dynamics simulations were carried out to characterize the interactions between glutathione (GSH, host molecule and hydroxyl radical (OH(•, guest molecule. From this analysis, two distinct steps were identified in the recognition process of hydroxyl radical by glutathione: catching and steering, based on the interactions between the host-guest molecules. Over 78% of all interactions are related to the catching mechanism via complex formation between anionic carboxyl groups and the OH radical, hence both terminal residues of GSH serve as recognition sites. The glycine residue has an additional role in the recognition of OH radical, namely the steering. The flexibility of the Gly residue enables the formation of further interactions of other parts of glutathione (e.g. thiol, α- and β-carbons with the lone electron pair of the hydroxyl radical. Moreover, quantum chemical calculations were carried out on selected GSH/OH(• complexes and on appropriate GSH conformers to describe the energy profile of the recognition process. The relative enthalpy and the free energy changes of the radical recognition of the strongest complexes varied from -42.4 to -27.8 kJ/mol and from -21.3 to 9.8 kJ/mol, respectively. These complexes, containing two or more intermolecular interactions, would be the starting configurations for the hydrogen atom migration to quench the hydroxyl radical via different reaction channels.

Sistema inteligente para evaluación de programas tutores

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Luz Daicy Alvarado

2002-01-01

Full Text Available El mecanismo evaluador que se presenta a continuación forma parte de un proyecto que busca el desarrollo de un Sistema de enseñanza asistida por ordenador (EAO basado en tutores inteligentes. Se pretende que este mecanismo, basado en herramientas de «aprendizaje automático», tenga la capacidad para capturar una «imagen» que indique el grado de comprensión de la materia por parte del alumno e identifique los aspectos en los que el estudiante tiene dificultades. Con esa información se retroalimentará a un sistema tutor de manera que este último tome una decisión acerca de la estrategia educativa por seguir.

Development of a new free radical absorption capacity assay method for antioxidants: aroxyl radical absorption capacity (ARAC).

Science.gov (United States)

Nagaoka, Shin-ichi; Nagai, Kanae; Fujii, Yuko; Ouchi, Aya; Mukai, Kazuo

2013-10-23

A new free radical absorption capacity assay method is proposed with use of an aroxyl radical (2,6-di-tert-butyl-4-(4'-methoxyphenyl)phenoxyl radical) and stopped-flow spectroscopy and is named the aroxyl radical absorption capacity (ARAC) assay method. The free radical absorption capacity (ARAC value) of each tocopherol was determined through measurement of the radical-scavenging rate constant in ethanol. The ARAC value could also be evaluated through measurement of the half-life of the aroxyl radical during the scavenging reaction. For the estimation of the free radical absorption capacity, the aroxyl radical was more suitable than the DPPH radical, galvinoxyl, and p-nitrophenyl nitronyl nitroxide. The ARAC value in tocopherols showed the same tendency as the free radical absorption capacities reported previously, and the tendency was independent of an oxygen radical participating in the scavenging reaction and of a medium surrounding the tocopherol and oxygen radical. The ARAC value can be directly connected to the free radical-scavenging rate constant, and the ARAC method has the advantage of treating a stable and isolable radical (aroxyl radical) in a user-friendly organic solvent (ethanol). The ARAC method was also successfully applied to a palm oil extract. Accordingly, the ARAC method would be useful in free radical absorption capacity assay of antioxidative reagents and foods.

REMOCIÓN DE ARSÉNICO (V ASISTIDA POR OXIDACIÓN UV SOLAR EN UN FOTO-REACTOR TUBULAR DE SECCIÓN CIRCULAR

Directory of Open Access Journals (Sweden)

Ramiro Escalera Vásquez

2010-01-01

Full Text Available Se ha construido y caracterizado un foto-reactor tubular de sección circular para su aplicación al tratamiento de aguas subterráneas contaminadas con Arsénico, As(V, utilizando las técnica de la Remoción de Arsénico por Oxidación Solar (RAOS. El concentrador solar que posee una capacidad de radiación equivalente a 2,8 soles, fue construido reciclando materiales desechados: tubos de vidrio proveniente de lámparas de Ne y tubos de desagüe sanitario de 6” (PVC, recubiertos por láminas de aluminio. Pruebas simultáneas sin agitación,realizadas aplicando la radiación UV solar a aguas sintéticas, demostraron que la remoción de As(V en el foto-reactor es más rápida queen un tubo de vidrio sólo y en una botella PET de 2 litros, logrando remociones mayores al 98% en todos los casos. Los tiempos para la aparición de los flóculos de complejo Fe-citrato fueron de 40, 50 y 90 min respectivamente, para intensidades de radiación UVA integral (290-390 nm entre 50 y 70 Wm-2. Pruebas de irradiación seguidas de agitación controlada a 30-33 s-1 de gradiente de velocidad, demostraron que el foto-reactor acelera el proceso de formación de flóculos fácilmente sedimentables al cabo de 20-30 min de agitación. Los tiempos de irradiación óptimos para el foto-reactor, el tubo y la botella son de 15, 25 y 60 min, respectivamente. Pruebas en régimen de flujo continuo en un foto-reactor de aproximadamente 1 m2 de área, con un tiempo de residencia hidráulica (igual al tiempo de irradiación de 15 min, mostraron la formación inmediata de flóculos fácilmente sedimentables cuando se agitan a 33 s-1 durante 20-30 min, lográndose una remoción del 98,36% una concentración remanente de 16,5 mgL-1 de As(V en aguas decantadas. Esto significa que se pueden tratar aproximadamente 130 Lm-2 en una jornada de 6 horas de radiación UVA de 50-70 Wm-2 de intensidad.

Physiology of free radicals

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Stevanović Jelka

2011-01-01

Full Text Available Free radicals imply that every atom, molecule, ion, group of atoms, or molecules with one or several non-paired electrons in outer orbital. Among these are: nitrogenoxide (NO•, superoxide-anion-radical (O2•-, hydroxyl radical (OH•, peroxyl radical (ROO•, alcoxyl radical (RO• and hydroperoxyl radical (HO2•. However, reactive oxygen species also include components without non-paired electrons in outer orbital (so-called reactive non-radical agents, such as: singlet oxygen (1O2, peroxynitrite (ONOO-, hydrogen-peroxide (H2O2, hypochloric acid (eg. HOCl and ozone (O3. High concentrations of free radicals lead to the development of oxidative stress which is a precondition for numerous pathological effects. However, low and moderate concentrations of these matter, which occur quite normally during cell metabolic activity, play multiple significant roles in many reactions. Some of these are: regulation of signal pathways within the cell and between cells, the role of chemoattractors and leukocyte activators, the role in phagocytosis, participation in maintaining, changes in the position and shape of the cell, assisting the cell during adaption and recovery from damage (e.g.caused by physical effort, the role in normal cell growth, programmed cell death (apoptosis and cell ageing, in the synthesis of essential biological compounds and energy production, as well as the contribution to the regulation of the vascular tone, actually, tissue vascularization.

Engineering a horseradish peroxidase C stable to radical attacks by mutating multiple radical coupling sites.

Science.gov (United States)

Kim, Su Jin; Joo, Jeong Chan; Song, Bong Keun; Yoo, Young Je; Kim, Yong Hwan

2015-04-01

Peroxidases have great potential as industrial biocatalysts. In particular, the oxidative polymerization of phenolic compounds catalyzed by peroxidases has been extensively examined because of the advantage of this method over other conventional chemical methods. However, the industrial application of peroxidases is often limited because of their rapid inactivation by phenoxyl radicals during oxidative polymerization. In this work, we report a novel protein engineering approach to improve the radical stability of horseradish peroxidase isozyme C (HRPC). Phenylalanine residues that are vulnerable to modification by the phenoxyl radicals were identified using mass spectrometry analysis. UV-Vis and CD spectra showed that radical coupling did not change the secondary structure or the active site of HRPC. Four phenylalanine (Phe) residues (F68, F142, F143, and F179) were each mutated to alanine residues to generate single mutants to examine the role of these sites in radical coupling. Despite marginal improvement of radical stability, each single mutant still exhibited rapid radical inactivation. To further reduce inactivation by radical coupling, the four substitution mutations were combined in F68A/F142A/F143A/F179A. This mutant demonstrated dramatic enhancement of radical stability by retaining 41% of its initial activity compared to the wild-type, which was completely inactivated. Structure and sequence alignment revealed that radical-vulnerable Phe residues of HPRC are conserved in homologous peroxidases, which showed the same rapid inactivation tendency as HRPC. Based on our site-directed mutagenesis and biochemical characterization, we have shown that engineering radical-vulnerable residues to eliminate multiple radical coupling can be a good strategy to improve the stability of peroxidases against radical attack. © 2014 Wiley Periodicals, Inc.

Cirugía conservadora y radical en estadíos tempranos del cáncer de mama

OpenAIRE

Nápoles Izquierdo, Yunexis; García Novoa, Wilfredo; Díaz Agüero, Heriberto; Báez Pupo, María Margarita

2009-01-01

Fundamento: El cáncer de mama es un problema de salud a escala internacional la cual ha aumentado en los últimos años las tasas de morbilidad y mortalidad, se plantea que cada quince minutos fallece una mujer por esta causa. Objetivo: Valorar los resultados de la cirugía conservadora y radical en estadíos tempranos del cáncer de mama. Método: Se realizó un estudio retrospectivo de casos y controles, la muestra estuvo constituida por treinta pacientes, a las que se le aplicó cirugía conservado...

Vinylcyclopropylacyl and polyeneacyl radicals. Intramolecular ketene alkyl radical additions in ring synthesis.

Science.gov (United States)

De Boeck, Benoit; Herbert, Nicola M A; Harrington-Frost, Nicole M; Pattenden, Gerald

2005-01-21

Treatment of a variety of substituted vinylcyclopropyl selenyl esters, e.g. 11, with Bu(3)SnH-AIBN in refluxing benzene leads to the corresponding acyl radical intermediates, which undergo rearrangement and intramolecular cyclisations via their ketene alkyl radical equivalents producing cyclohexenones in 50-60% yield. By contrast, treatment of conjugated triene selenyl esters, e.g. 32, with Bu(3)SnH-AIBN produces substituted 2-cyclopentenones via intramolecular cyclisations of their ketene alkyl radical intermediates. Under the same radical-initiating conditions the selenyl esters derived from o-vinylbenzoic acid and o-vinylcinnamic acid undergo intramolecular cyclisations producing 1-indanone and 5,6-dihydrobenzocyclohepten-7-one respectively in 60-70% yields. A tandem radical cyclisation from the alpha,beta,gamma,delta-diene selenyl ester 31 provides an expeditious synthesis of the diquinane 35 in 69% yield.

Erector spinae plane block for radical mastectomy: A new indication?

Science.gov (United States)

Veiga, M; Costa, D; Brazão, I

2018-02-01

The erector spinae plane block is a technique recently described by Forero et al. in September 2016. It has applications in the control of chronic pain with neuropathic component of the chest wall, and for pain control in thoracoscopic surgery. In this article, we describe the use of this technique as part of a multimodal analgesic approach in a 40-year-old woman, who underwent radical mastectomy due to breast cancer. By performing this block before anesthetic induction, we have achieved an opioid sparing effect, avoiding a possible immunomodulatory effect, although not yet proven in humans. During hospitalization, the patient reported no pain (0/10 in numeric scale), without resorting to rescue analgesia. The easy, fast and safe execution of erector spinae plane block makes it a promising technique in the context of surgical pain during radical mastectomy. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Análisis de la degradación de recubrimientos de barrera térmica por espectroscopía de impedancia electroquímica

Directory of Open Access Journals (Sweden)

Gómez-García, J.

2007-10-01

Full Text Available This investigation correlates the microstructure of a thermal barrier coating, analysed through scanning electron microscopy and X-ray microanalysis, with the electrochemical impedance spectroscopy data which show the variation in electrical properties after isothermal oxidation. A thermal barrier coating comprising a ceramic top layer, ZrO2 8Y2O3 (weight %, and an overlay coating, Ni 22Cr 10Al 1Y (weight %, air plasma sprayed over a nickel base alloy In 600 substrate was studied. These materials were heat treated in air at 1050 ºC for 72, 144 y 336 h. A thermally grown oxide layer, mainly comprising Cr y Al oxides, was formed between the ceramic and the overlay coating. This layer modified the electrical response of the thermal barrier coating in the electrochemical impedance spectroscopy tests.

Este trabajo correlaciona la microestructura de un recubrimiento de barrera térmica, estudiada mediante microscopía electrónica de barrido y microanálisis de rayos X, con los resultados obtenidos mediante espectroscopía de impedancia electroquímica que muestran la variación de sus propiedades eléctricas tras un proceso de oxidación isoterma. El sistema estudiado está formado por una capa cerámica, ZrO2 8Y2O3 (% en masa, y un anclaje metálico, Ni 22Cr 10Al 1Y (% en masa, depositados ambos por proyección térmica asistida por plasma sobre un sustrato de aleación base níquel In 600. Estos recubrimientos se oxidaron isotérmicamente en aire a 1050 ºC durante 72, 144 y 336 h. Se formó una capa intermedia de óxidos (“thermally grown oxides”, TGO entre el anclaje metálico y el recubrimiento cerámico formada por una mezcla de óxidos de Cr y Al que se tradujo en la variación de los parámetros característicos de la impedancia de la barrera térmica.

Serum Hydroxyl Radical Scavenging Capacity as Quantified with Iron-Free Hydroxyl Radical Source

Science.gov (United States)

Endo, Nobuyuki; Oowada, Shigeru; Sueishi, Yoshimi; Shimmei, Masashi; Makino, Keisuke; Fujii, Hirotada; Kotake, Yashige

2009-01-01

We have developed a simple ESR spin trapping based method for hydroxyl (OH) radical scavenging-capacity determination, using iron-free OH radical source. Instead of the widely used Fenton reaction, a short (typically 5 seconds) in situ UV-photolysis of a dilute hydrogen peroxide aqueous solution was employed to generate reproducible amounts of OH radicals. ESR spin trapping was applied to quantify OH radicals; the decrease in the OH radical level due to the specimen’s scavenging activity was converted into the OH radical scavenging capacity (rate). The validity of the method was confirmed in pure antioxidants, and the agreement with the previous data was satisfactory. In the second half of this work, the new method was applied to the sera of chronic renal failure (CRF) patients. We show for the first time that after hemodialysis, OH radical scavenging capacity of the CRF serum was restored to the level of healthy control. This method is simple and rapid, and the low concentration hydrogen peroxide is the only chemical added to the system, that could eliminate the complexity of iron-involved Fenton reactions or the use of the pulse-radiolysis system. PMID:19794928

Editorial. La estadística: Disforia en ciencias de la salud.

OpenAIRE

Salinas, Pedro José

2007-01-01

Editorial. La estadística: Disforia en ciencias de la salud. Editorial. Statistics: Disforia in health sciences. Salinas, Pedro José Colecistectomía laparoscópica asistida por robot. Una nueva técnica aprendida. Robot-assisted laparoscopic cholecystectomy. A new learnt technique. Lucena Olavarrieta, Jorge R. Coronel, Paúl Orellana, Ysabelen Diagnóstico ecográfico de craneoraquisquisis: reporte de caso. Ecographic diagnoses of craneorachischisis: A case report. Te...

Radical transfer between proteins: role of tyrosine, tryptophan and protein peroxyl radicals

International Nuclear Information System (INIS)

Irwin, J.A.; Ostdal, H.; Davies, M.J.

1998-01-01

Reaction of the Fe(III) forms of the heme proteins myoglobin (Mb) and horseradish peroxidase (HRP) with H 2 O 2 gives rise to high-oxidation-state heme-derived species which can be described as a Fe(IV)-oxo porphyrin radical-cation ('Compound 1'). In the case of Mb, the Fe(IV)-oxo porphyrin radical-cation undergoes rapid electron transfer with the surrounding protein to give protein (globin)-derived radicals and an Fe(lV)-oxo species ('Compound 2'). The globin-derived radicals have been shown to be located at two (or more) sites: Tyr-103 or Trp-14, with the latter radical known to react with oxygen to give a Trp-derived peroxyl radical (Mb-Trp-OO*). With HRP, the Fe(lV)-oxo porphyrin radical-cation carries out two successive one-electron oxidation reactions at the exposed heme edge to give firstly 'Compound 2' [the Fe(lV)oxo species] and then the resting Fe(III) state of the enzyme. n this study we have investigated whether the Trp-14 peroxyl radical from Mb and the Compound 1 and 2 species from HRP (in the absence and presence of free Tyr) can oxidise amino acids, peptides and proteins. Such reactions constitute intermolecular protein-to-protein radical transfer reactions and hence protein chain-oxidation. We have also examined whether these oxidants react with antioxidants. Reaction of these heme-protein derived oxidants with amino acids, proteins and antioxidants has been carried out at room temperature for defined periods of time before freeze-quenching to 77K to halt reaction. The radical species present in the reaction system at the time of freezing were subsequently examined by EPR spectroscopy at 77K. Three free amino acids, Tyr, Trp and Cys (with Cys the least efficient) have been shown to react rapidly with Mb-Trp-OO*, as evidenced by the loss of the characteristic EPR features of Mb-Trp-OO* on inclusion of increasing concentrations of the amino acids. All other amino acids are much less reactive. Evidence has also been obtained for (inefficient) hydrogen

Produccion Gaseosa del Cometa Halley: Erupciones Y Fotodisociacion del Radical OH

Science.gov (United States)

Silva, A. M.; Mirabel, I. F.

1990-11-01

RESUMEN:En este trabajo informamos la detecci6n de 20 erupciones en la li'nea de =18cm (1667MHz) del radical OH en el Cometa Halley.Las observaciones incluyen todos los monitoreos existentes y se extienden desde 120 dias antes del perihelio hasta 90 dias despues.Se detectan bruscos crecimientos en el flujo medido,hasta un factor 1O,seguidos por decaimientos lentos asociados con la fotodisociaci6n del OH. Se obtuvieron valores para el tiempo de vida fotoquimico del OH y del H2O basandose en el modelo desarrollado previamente por Silva(1988). Esos tiempos de vida estan de acuerdo con predicciones teoricas y con las observaciones en el Ultravioleta, y los resultados, los que son fuertemente dependientes de la velocidad heliocentrica del Coineta (variando hasta un factor 6), han sido calculados para varios rangos de velocidad entre +28 y -28 km/seg. Key wo'L :

Homegrown religious radicalization

DEFF Research Database (Denmark)

Khawaja, Iram

It has been reported that a growing number of youngsters from Western Europe are engaging in conflicts motivated by religious and political conflicts in the Middle East. This paper explores the reasons behind this seemingly religious radicalization from the point of view of the youngsters...... youngsters and parents of youngsters who have chosen a radicalized path in life. The paper will shed light on how the sense of and yearning for belonging and recognition have to be taken into account in our understanding of homegrown religious radicalization...

Sobre el mal radical. Ensayo de la heterodoxia kantiana

Directory of Open Access Journals (Sweden)

Gómez Caffarena, José

2004-06-01

Full Text Available The kantian theory of a «radical evil inhabiting human nature» contrasts with a general anthropological optimistic tenor perceptible in kantian philosophy. It meant a significant turning point in the often too superficial optimistic trends of the Enlightenment. Hut its literal sense (appealing to an act of pre-individual freedom has an obvious difficulty. The present paper proposes an heterodox interpretation, which would avoid the difficulty, although so losing part of the tempting enigmatic reach of the kantian proposal.

La teoría del «mal radical en la naturaleza humana», expuesta por Kant en La religión dentro de los límites de la mera razón, hace contraste con el optimismo antropológico que empapa el Criticismo. Constituyó, sin duda, una importante denuncia frente a la banalidad de muchos optimismos ilustrados. Pero su letra (acto de libertad pre-individual tiene una obvia dificultad. El artículo propone una reinterpretación que la evitaría, aunque desdramatizando un tanto el tentador alcance enigmático de la propuesta kantiana.

Laparoscopic radical trachelectomy.

Science.gov (United States)

Rendón, Gabriel J; Ramirez, Pedro T; Frumovitz, Michael; Schmeler, Kathleen M; Pareja, Rene

2012-01-01

The standard treatment for patients with early-stage cervical cancer has been radical hysterectomy. However, for women interested in future fertility, radical trachelectomy is now considered a safe and feasible option. The use of minimally invasive surgical techniques to perform this procedure has recently been reported. We report the first case of a laparoscopic radical trachelectomy performed in a developing country. The patient is a nulligravid, 30-y-old female with stage IB1 adenocarcinoma of the cervix who desired future fertility. She underwent a laparoscopic radical trachelectomy and bilateral pelvic lymph node dissection. The operative time was 340 min, and the estimated blood loss was 100mL. There were no intraoperative or postoperative complications. The final pathology showed no evidence of residual disease, and all pelvic lymph nodes were negative. At 20 mo of follow-up, the patient is having regular menses but has not yet attempted to become pregnant. There is no evidence of recurrence. Laparoscopic radical trachelectomy with pelvic lymphadenectomy in a young woman who desires future fertility may also be an alternative technique in the treatment of early cervical cancer in developing countries.

Modulación del crecimiento vertebral mediante electrocoagulación hemicircunferencial vertebral asistida

OpenAIRE

Caballero García, Alberto

2011-01-01

Nuestro trabajo está basado en la posibilidad de controlar el desarrollo asimétrico de los cartílagos de crecimiento vertebral, mediante la realización de una fisiodesis hemivertebral, con electrocoagulación, videoasistida por toracoscópica. Se realizará en cinco niveles torácicos, con un abordaje anterior mínimamente invasivo. Por lo tanto, planteamos como hipótesis de trabajo que La destrucción de las fisis de crecimiento vertebral mediante electrocoagulación, videoasistida por vía toracosc...

Radical Evil

Directory of Open Access Journals (Sweden)

Carlos Manrique

2007-12-01

Full Text Available There is an aporia in Kant’s analysis of evil: he defines radical evilas an invisible disposition of the will, but he also demands an inferential connection between visible evil actions and this invisible disposition. This inference,however, undermines the radical invisibility of radical evil according to Kant’s own definition of the latter. Noting how this invisibility of moral worth is a distinctive feature of Kant’s approach to the moral problem, the paper then asks why, in the Groundwork, he nonetheless forecloses a question about evil that seems to be consistent with this approach. It is argued that to account for this aporia and this foreclosure, one has to interrogate the way in which the category of religion orients Kant’s incipient philosophy of history in Die Religion.

CRITICAL THEORY OF THE RADICAL LOVE TEORÍA CRÍTICA DEL RADICAL LOVE

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Lena de Botton

2009-11-01

Full Text Available The understanding of the sexual-affective relationships has historically notbeen tackled by science, but placed in the context of instincts and irrationality. In thissense, the critical theory of the Radical Love provides a contribution to critical pedagogyallowing people to understand the mechanisms that direct their emotions and theprocess of election in the sexual-affective relationships. It is about understanding whodo we fall in love for, why and to which values is this desire linked being able to have agreat repercussion in our lives as it provides us with the tools to develop satisfactorysexual-affective relationships. It also offers us guidelines for a preventive educationregarding gender violence by enabling us to understand the attraction models in whichwe have been socialised and which are influencing our desire and elections.Históricamente la comprensión de las relaciones sexual-afectivas no ha sidoabordada desde la ciencia, sino que ha sido situada en el marco de los instintos y de lairracionalidad. En este sentido, la teoría crítica del Radical Love realiza una contribuciónpara la pedagogía crítica al permitir a las personas comprender los mecanismos querigen en las emociones y en el proceso de elección de las relaciones sexual-afectivas. Setrata de comprender de quiénes nos enamoramos, por qué y a qué valores se entrelazaeste deseo, puesto que todo ello puede tener una gran repercusión en nuestras vidas.Avanzar hacia esta comprensión nos da las herramientas para poder desarrollar unasrelaciones afectivo-sexuales satisfactorias. También nos ofrece orientaciones para unaeducación preventiva de la violencia de género al permitirnos comprender los modelosde atracción en los que nos hemos socializado y que influyen en nuestro deseo y elección.

NARRATIVAS RELIGIOSAS Y POLÍTICAS EN LA DISPUTA POR LA EDUCACIÓN SEXUAL EN ARGENTINA

OpenAIRE

Juan Cruz Esquive

2013-01-01

La educación sexual, junto con la distribución gratuita de anticonceptivos y de la píldora del ‘día después’, el matrimonio entre personas del mismo sexo, la fecundación asistida, la autodeterminación de la identidad sexual, la eutanasia y la despenalización del aborto, conforman uno de los ‘núcleos sensibles’ que cristalizan pujas y negociaciones entre el Estado, la dirigencia política y las instituciones religiosas a la hora de definir los fundamentos regulatorios de las políticas públicas ...

Radical constructivism: Between realism and solipsism

Science.gov (United States)

Martínez-Delgado, Alberto

2002-11-01

This paper criticizes radical constructivism of the Glasersfeld type, pointing out some contradictions between the declared radical principles and their theoretical and practical development. These contradictions manifest themselves in a frequent oscillation between solipsism and realism, despite constructivist claims to be an anti-realist theory. The paper also points out the contradiction between the relativism of the radical constructivist principles and the constructivist exclusion of other epistemological or educational paradigms. It also disputes the originality and importance of the radical constructivist paradigm, suggesting the idea of an isomorphism between radical constructivist theory and contemplative realism. In addition, some pedagogical and scientific methodological aspects of the radical constructivist model are examined. Although radical constructivism claims to be a rational theory and advocates deductive thinking, it is argued that there is no logical deductive connection between the radical principles of constructivism and the radical constructivist ideas about scientific research and learning. The paper suggests the possibility of an ideological substratum in the construction and hegemonic success of subjective constructivism and, finally, briefly advances an alternative realist model to epistemological and educational radical constructivism.

Láser de dióxido de carbono fraccionado asociado a corticoide tópico para el tratamiento del prurito en las secuelas cicatriciales del paciente quemado

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Sara A. González-Porto

Full Text Available El prurito en los pacientes quemados supone una secuela frecuente que puede ser incapacitante y difícilmente controlable mediante tratamiento médico. Presentamos el caso de un paciente con prurito grave resistente a tratamiento médico y los resultados tras el tratamiento con láser ablativo y liberación de corticoide local asistida por láser. Se trata de un paciente con quemaduras graves en el 70% de superficie corporal, con prurito refractario a tratamiento médico y lesiones por rascado que precisaron de sedorrelajación e intubación orotraqueal, y en el que realizamos una sola sesión de tratamiento con láser CO² fraccionado tras la que se aplicó cura oclusiva con triamcinolona acetónido disuelta en suero (20 mg/ml. La evaluación del resultado se realizó mediante valoración del prurito (escala Burn Itch Questionnaire y del resultado clínico y estético de la cicatriz (escalas Vancouver Scar Scale y Patient and Observer Scar Assessment Scale. Logramos un buen control del prurito y de las lesiones por rascado sin complicaciones asociadas. La liberación de fármacos asistida por láser fue la base del nuestro tratamiento, en el que el láser ablativo crea canales de comunicación transepidérmicos que favorecen la entrada del corticoide a la dermis y el efecto inmediato del mismo. Esta modalidad de tratamiento y este nuevo concepto clínico se presentan como una alternativa terapéutica importante en el tratamiento del prurito refractario en el paciente quemado.

Salvage robotic radical prostatectomy

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Samuel D Kaffenberger

2014-01-01

Full Text Available Failure of non-surgical primary treatment for localized prostate cancer is a common occurrence, with rates of disease recurrence ranging from 20% to 60%. In a large proportion of patients, disease recurrence is clinically localized and therefore potentially curable. Unfortunately, due to the complex and potentially morbid nature of salvage treatment, radical salvage surgery is uncommonly performed. In an attempt to decrease the morbidity of salvage therapy without sacrificing oncologic efficacy, a number of experienced centers have utilized robotic assistance to perform minimally invasive salvage radical prostatectomy. Herein, we critically evaluate the existing literature on salvage robotic radical prostatectomy with a focus on patient selection, perioperative complications and functional and early oncologic outcomes. These results are compared with contemporary and historical open salvage radical prostatectomy series and supplemented with insights we have gained from our experience with salvage robotic radical prostatectomy. The body of evidence by which conclusions regarding the efficacy and safety of robotic salvage radical prostatectomy can be drawn comprises fewer than 200 patients with limited follow-up. Preliminary results are promising and some outcomes have been favorable when compared with contemporary open salvage prostatectomy series. Advantages of the robotic platform in the performance of salvage radical prostatectomy include decreased blood loss, short length of stay and improved visualization. Greater experience is required to confirm the long-term oncologic efficacy and functional outcomes as well as the generalizability of results achieved at experienced centers.

Muoniated acyl and thioacyl radicals

International Nuclear Information System (INIS)

McKenzie, Iain; Brodovitch, Jean-Claude; Ghandi, Khashayar; Percival, Paul W.

2006-01-01

The product of the reaction of muonium with tert-butylisocyanate was previously assigned as the muoniated tert-butylaminyl radical (I. McKenzie, J.-C. Brodovitch, K. Ghandi, S. Kecman, P. W. Percival, Physica B 326 (2003) 76). This assignment is incorrect since the muon and 14 N hyperfine-coupling constants (hfcc) of this radical would have the opposite sign, which is in conflict with the experimental results. The radical is now reassigned as the muoniated N-tert-butylcarbamoyl radical, based on the similarities between the experimental muon and 14 N hfcc and hfcc calculated at the UB3LYP/6-311G(d,p)//UB3LYP/EPR-III level. The large zero-point energy in the N-Mu bond results in the dissociation barrier of the muoniated N-tert-butylcarbamoyl radical being above the combined energy of the reactants, in contrast to the N-tert-butylcarbamoyl radical where the dissociation barrier lies below the combined energy of the reactants. The reaction of muonium with tert-butylisothiocyanate produced both conformers of the muoniated N-tert-butylthiocarbamoyl radical and their assignment was based on the similarities between the experimental and calculated muon hfcc. These are the first acyl and thioacyl radicals to be directly detected by muon spin spectroscopy

Muoniated acyl and thioacyl radicals

Energy Technology Data Exchange (ETDEWEB)

McKenzie, Iain [TRIUMF and Department of Chemistry, 8888 University Drive, Simon Fraser University, Burnaby B.C., V5A 1S6 (Canada); Brodovitch, Jean-Claude [TRIUMF and Department of Chemistry, 8888 University Drive, Simon Fraser University, Burnaby B.C., V5A 1S6 (Canada); Ghandi, Khashayar [TRIUMF and Department of Chemistry, 8888 University Drive, Simon Fraser University, Burnaby B.C., V5A 1S6 (Canada); Percival, Paul W. [TRIUMF and Department of Chemistry, 8888 University Drive, Simon Fraser University, Burnaby B.C., V5A 1S6 (Canada)]. E-mail: percival@sfu.ca

2006-03-31

The product of the reaction of muonium with tert-butylisocyanate was previously assigned as the muoniated tert-butylaminyl radical (I. McKenzie, J.-C. Brodovitch, K. Ghandi, S. Kecman, P. W. Percival, Physica B 326 (2003) 76). This assignment is incorrect since the muon and {sup 14}N hyperfine-coupling constants (hfcc) of this radical would have the opposite sign, which is in conflict with the experimental results. The radical is now reassigned as the muoniated N-tert-butylcarbamoyl radical, based on the similarities between the experimental muon and {sup 14}N hfcc and hfcc calculated at the UB3LYP/6-311G(d,p)//UB3LYP/EPR-III level. The large zero-point energy in the N-Mu bond results in the dissociation barrier of the muoniated N-tert-butylcarbamoyl radical being above the combined energy of the reactants, in contrast to the N-tert-butylcarbamoyl radical where the dissociation barrier lies below the combined energy of the reactants. The reaction of muonium with tert-butylisothiocyanate produced both conformers of the muoniated N-tert-butylthiocarbamoyl radical and their assignment was based on the similarities between the experimental and calculated muon hfcc. These are the first acyl and thioacyl radicals to be directly detected by muon spin spectroscopy.

Control óptimo de par para máquinas SynRM aplicadas a vehículo eléctrico

OpenAIRE

Trancho, Elena; Ibarra Basabe, Edorta; Arias Pujol, Antoni; Kortabarria, Iñigo

2017-01-01

Las máquinas de reluctancia síncrona asistidas por imanes están atrayendo un considerable interés como alternativa a las máquinas síncronas de imanes permanentes para su uso en sistemas de propulsión de vehículos eléctricos. El control óptimo de estas máquinas (incluyendo operación en debilitamiento de campo) puede resultar complejo, ya que estas son, por lo general, muy sensibles al fenómeno de la saturación magnética. En este artículo se trata su control, desde los reguladores hasta el prec...

Equinoterapia en niños con autismo

OpenAIRE

Martinez Alvernia, Carlos Francisco

2015-01-01

Introducción: Autismo es un trastorno del desarrollo caracterizado por compromiso en interacción social, habilidades de lenguaje, presentando rituales con estereotipias. Sin tratamientos curativos, actualmente se buscan terapias alternativas. Un incremento de la literatura científica de terapias asistidas con animales se ha evidenciado, demostrando mejoría en pacientes autistas con la equinoterapia. Objetivo: Realizar una revisión sistemática de la literatura para evaluar efectividad de la eq...

Muonium and muonic radicals

International Nuclear Information System (INIS)

Burkhard, P.; Fischer, H.; Roduner, E.; Strub, W.; Geeson, D.; Symons, M.C.R.

1985-01-01

An energetic positive muon which is injected in a liquid sample of substrate molecules (S) creates an ionization track consisting of substrate cations (S + ) and electrons. Near the end of this track the muon may combine with an electron to form muonium (Mu) which is observable in inert liquids, but which reacts by addition to form a radical. Alternatively, the electron can add to S to form S - , which then combines with the muon to form the radical. Furthermore, instead of ending up in Mu or in a radical the muon may stay in a diamagnetic environment as a solvated muon, or as a muon substituting a proton in a molecule. Of interest in these schemes are the mechanisms and rates of formation of muonated radicals and in particular the rate constants for their reactions to products. Investigations are based on the observation of Mu and the radical by means of the μSR technique in transverse magnetic fields. (Auth.)

Determinación de residuos de plaguicidas organoclorados en suero sanguíneo de trabajadores de cultivo de Café y plátano en el departamento del quindío por gc-μecd

Directory of Open Access Journals (Sweden)

Santiago Bedoya P

2014-10-01

Full Text Available La falta de conocimiento del potencial nocivo de los plaguicidas por parte de los trabajadores agrícolas puede ocasionar graves problemas en su salud y en la de los consumidores. Se determinó la residualidad de plaguicidas organoclorados (OCP, por sus siglas en inglés en muestras de suero sanguíneo de trabajadores agrícolas de cultivos de café y plátano en el departamento del Quindío. Para la extracción de los analitos se implementó un método rápido, seguro, económico y eficiente de microextracción dispersiva en fase líquida (DLLME, por sus siglas en inglés asistida por sonicación, logrando la extracción de 20 OCP de 200 μL de suero sanguíneo en un tiempo de 35 min con porcentajes de recuperación mayores al 87 %. Se empleó cromatografía de gases con detector de micro captura de electrones (GC-μECD para el análisis de los OCP. Para cada analito, los coeficientes de correlación obtenidos a partir de las curvas de calibración interna fueron superiores a 0,9996, los límites de detección (LOD se establecieron entre 0,02 a 0,04 ng/mL y los límites de cuantificación (LOQ por debajo de 0,14 ng/mL. En el 55 % de las muestras analizadas (166 se evidenció la presencia de: 4,4-DDE, alfa y gamma BHC, endrin aldehído, endosulfan II, endosulfan sulfato, heptacloro y metoxicloro, compuestos que están prohibidos por la regulación nacional e internacional.

Leghemoglobin-derived radicals. Evidence for multiple protein-derived radicals and the initiation of peribacteroid membrane damage

DEFF Research Database (Denmark)

Moreau, S; Davies, Michael Jonathan; Mathieu, C

1996-01-01

, with the consequent generation of lipid-derived radicals. The formation of such radicals may result in the depletion of membrane antioxidants and the initiation of lipid peroxidation. This transfer of damage from the heme center via the protein surface to neighboring membranes may be of considerable biological......-derived phenoxyl radical present at Tyr-133 in the soybean protein and Tyr-138 in the lupin protein. To obtain further information on these protein radicals and their potential interaction with the physiologically important peribacteroid membrane (which surrounds the microsymbiont in vivo), EPR spin trapping......); these radicals may be side chain- or alpha-carbon-derived, their exact sites have not been determined. Some of these radicals are on the protein surface and may be key intermediates in the formation of protein dimers. These radicals have been shown to be capable of reacting with peribacteroid membrane fractions...

Studies of radiation-produced radicals and radical ions. Progress report, June 1, 1981-August 31, 1982

International Nuclear Information System (INIS)

Williams, T.F.

1982-01-01

The discovery and characterization of novel radical ions produced by the γ irradiation of solids continues to be a fertile field for investigation. This Progress Report describes the generation and ESR identification of several new paramagnetic species, some of which have long been sought as important intermediates in radiation chemistry. We have also contributed to a general theoretical problem in ESR spectroscopy. Solid-state studies of electron attachment reactions, both non-dissociative and dissociative, reveal interesting structural and chemical information about the molecular nature of these processes for simple compounds. In particular, ESR measurements of the spin distribution in the products allow a fairly sharp distinction to be drawn between radical anions and radical-anion pairs or adducts. Dimer radical anion formation can also take place but the crystal structure plays a role in this process, as expected. Some radical anions undergo photolysis to give radical-anion pairs which may then revert back to the original radical anion by a thermal reaction. The chemistry of these reversible processes is made more intricate by a competing reaction in which the radical abstracts a hydrogen atom from a neighboring molecule. However, the unraveling of this complication has also served to extend our knowledge of the role of quantum tunneling in chemical reactions. The results of this investigation testify to the potential of solid-state techniques for the study of novel and frangible radical ions. Progress in this field shows no sign of abating, as witness the recent discovery of perfluorocycloalkane radical anions and alkane radical cations

Muonium-containing vinyl radicals

International Nuclear Information System (INIS)

Rhodes, C.J.; Symons, M.C.R.; Roduner, E.; Heming, M.

1987-01-01

Exposure of trimethylsilylacetylene and bis(trimethylsilyl)acetylene to positive muons gave radicals whose muon-electron hyperfine coupling constants establish that the corresponding vinyl radicals were formed. (author)

Radicals in arithmetic

NARCIS (Netherlands)

W.J. Palenstijn (Willem Jan)

2014-01-01

htmlabstractLet K be a field. A radical is an element of the algebraic closure of K of which a power is contained in K. In this thesis we develop a method for determining what we call entanglement. This describes unexpected additive relations between radicals, and is encoded in an entanglement

Do mecanicismo ao selecionismo: uma breve contextualização da transição do behaviorismo radical

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Robson Nascimento da Cruz

Full Text Available O behaviorismo radical, como filosofia da ciência do comportamento formulada por B. F. Skinner, tem sido desde sua criação alvo de inúmeras críticas e tentativas de rotulação. Dentre as principais críticas está a noção amplamente divulgada de que o behaviorismo radical e sua ciência, análise experimental do comportamento, adotam uma postura eminentemente mecanicista. Para tentar demonstrar o equívoco deste tipo de afirmação, este ensaio busca uma possível interpretação e contextualização do desenvolvimento do behaviorismo radical, no qual se destaca, principalmente, a necessidade de observar que apesar de Skinner ter iniciado seus estudos de psicologia dentro de uma tradição mecanicista, ele cedo adota uma posição que tem como função criticar e afastar-se deste tipo de pensamento.

Multiple free-radical scavenging capacity in serum

Science.gov (United States)

Oowada, Shigeru; Endo, Nobuyuki; Kameya, Hiromi; Shimmei, Masashi; Kotake, Yashige

2012-01-01

We have developed a method to determine serum scavenging-capacity profile against multiple free radical species, namely hydroxyl radical, superoxide radical, alkoxyl radical, alkylperoxyl radical, alkyl radical, and singlet oxygen. This method was applied to a cohort of chronic kidney disease patients. Each free radical species was produced with a common experimental procedure; i.e., uv/visible-light photolysis of free-radical precursor/sensitizer. The decrease in free-radical concentration by the presence of serum was quantified with electron spin resonance spin trapping method, from which the scavenging capacity was calculated. There was a significant capacity change in the disease group (n = 45) as compared with the healthy control group (n = 30). The percent values of disease’s scavenging capacity with respect to control group indicated statistically significant differences in all free-radical species except alkylperoxyl radical, i.e., hydroxyl radical, 73 ± 12% (p = 0.001); superoxide radical, 158 ± 50% (p = 0.001); alkoxyl radical, 121 ± 30% (p = 0.005); alkylperoxyl radical, 123 ± 32% (p>0.1); alkyl radical, 26 ± 14% (p = 0.001); and singlet oxygen, 57 ± 18% (p = 0.001). The scavenging capacity profile was illustrated using a radar chart, clearly demonstrating the characteristic change in the disease group. Although the cause of the scavenging capacity change by the disease state is not completely understood, the profile of multiple radical scavenging capacities may become a useful diagnostic tool. PMID:22962529

Preoperative radiochemotherapy and radical surgery in comparison with radical surgery alone

International Nuclear Information System (INIS)

Mohr, C.; Schettler, D.; Bohndorf, W.

1994-01-01

A multicentric, randomized study of squamous cell carcinoma (SCC) of the oral cavity and the oropharynx has been undertaken by DOeSAK. The results after radical surgery alone have been compared with the results of combined preoperative radiochemotherapy followed by radical surgery. Patients with primary (biopsy proven) SCC of the oral cavity or the oropharynx with tumor nodes metastasis (TNM) stages T2-4, N0-3, M0 were included in the study. A total of 141 patients were treated by radical surgery alone, whereas 127 patients were treated by radical surgery preceded by preoperative radiochemotherapy. The pre-operative treatment consisted of conventionally fractioned irradiation on the primary and the regional lymph nodes with a total dose of 36 Gy (5 x 2 Gy per week) and low-dose cisplatin chemotherapy with 5 x 12.5 mg cisplatin per m 2 of body surface during the first week of treatment. Radical surgery according to be DOeSAK definitions (DOeSAK, 1982) was performed after a delay of 10-14 days. During the follow-up period, 28.2% of all patients suffered from locoregional recurrence, and 27.2% of the patients died. The percentages were higher after radical surgery alone for locoregional recurrence (31% and 15.6%) and for death (28% and 18.6%). The life-table analysis showed improved survival rates of 4.5% after 1 year and 8.3% after 2 years in the group of patients treated with combined therapy. The demonstrated improvement appeared to be significant with the Gehan-Wilcoxon test as well as with the log rank test below a P value of 5%. (au) (29 refs.)

EL MENSAJE DE LA ECONOMIA POLITICA RADICAL

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Alfonso Barceló

2001-12-01

Full Text Available La economía se presenta a menudo como la ciencia social más madura y exacta, capaz de orientar acciones, realizar pronósticos, explicar el pasado. Todo ello de una manera, si no impecable, sí satisfactoria a grandes rasgos. Ya lo dijo Popper de manera poco cautelosa: "El éxito de la Economía Matemática muestra que por lo menos una ciencia social ha pasado por su revolución newtoniana" (Popper, 1957, 74. También goza la economía de buenas referencias en lo que atañe a su genealogía y tradición intelectual: algunas de sus máximas tienen un respetable pedigrí de más de dos siglos. Por otra parte, sus argumentaciones más preciadas suelen presentarse en la alta sociedad académica vestidas con formalismos matemáticos aparatosos, cuando no espectaculares. A primera vista parece, pues, hallarse en un estado muy saludable, bien orientada en cuanto a bases y perspectivas. Luego no es de extrañar que sea motivo de envidia y de imitación por parte de investigadores de campos vecinos que también aspiran a entender cómo funcionan los seres humanos en sociedad.El resultado final es un texto un tanto híbrido, a medio camino entre el ensayo de divulgación y las notas de clase. De todos modos, aunque sus objetivos sean modestos en lo que se refiere a rigor y originalidad, confío en que cumpla en alguna medida el cometido asignado, a saber, sugerir e incluso provocar. Deseo puntualizar, por último, que algunas de las ideas aquí expuestas se hallan argumentadas de forma más sistemática y cuidada en el artículo "Teoría económica y enfoque de la reproducción" (in Febrero, ed., Qué es la economía, Madrid, Pirámide, 1997, págs. 241-269, así como en mis libros Filosofía de la economía (Barcelona, Icaria, 1992 y Economía política radical (Madrid, Síntesis, 1998.

Radicals in arithmetic

NARCIS (Netherlands)

Palenstijn, Willem Jan

2014-01-01

Let K be a field. A radical is an element of the algebraic closure of K of which a power is contained in K. In this thesis we develop a method for determining what we call entanglement. This describes unexpected additive relations between radicals, and is encoded in an entanglement group. We give

Radicalization as a Vector: Exploring Non-Violent and Benevolent Processes of Radicalization.

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Ken Reidy

2018-03-01

Full Text Available Successful radicalization posits three outcomes: extremism, terrorism or both. As these are undesirable, radicalization is understood as wholly malevolent and governments work to prevent and/or stop it. Nonetheless, a handful of scholars have recognized that the same radicalization process which results in either outcome may, theoretically at least, also have beneficial outcomes such as environmental awareness or human rights. This article explores one such outcome. Based on interviews with British Muslim aid workers (n=6 operating in Jihadist conflict zones post Arab spring and using constructivist grounded theory, it illustrates how the research participants radicalized to humanitarianism which resulted in them assisting the most plighted of Muslims by deploying to the most wanton of areas: ones commonly referred to as Jihadist conflict zones. Evidently, these destinations are shared with Jihadists and given the array of other observable similarities (socio-demographics and [pre-]mobilization behaviours, these morally opposed groups become conflated by the security services. This is further compounded by the fact that Jihadists manipulate and/or impersonate aid workers so as to funnel people and funds. To distinguish both, this article documents the benevolent pathway of the research participants and juxtaposes it to scholarly knowledge on Jihadist pathways. Socialization was revealed to be the key distinguishing feature rather than descriptive risk factors (such as ideology or moral outrage because the process of radicalization was not found to be the start of the radicalized pathway. It concludes that benevolently radicalized Islamic groups constitute an effective means of pathway divergence for particular typologies by offering an attractive and prosocial alternative to Jihadism. This strengths-based preventative approach (“what’s right” takes the form of a community-centric market competitor to Jihadism rather than a problem

Radical cations of quadricyclane and norbornadiene in polar ZSM-5 matrices: Radical cation photochemical transformations without photons

International Nuclear Information System (INIS)

Barnabas, M.V.; Trifunac, A.D.

1994-01-01

Radical cations of quadricyclane (Q) and norbornadiene (NBD) are produced by γ-radiolysis in zeolites. In polar ZSM-5, only one radical cation is initially observed below 100K. Increasing the temperature above 200K gives rise to the cyclopentadiene radical cation. Higher temperatures (>360K) give rise to the cyclopenten-4-yl radical. The observation of cyclopentadiene radical cation implies the occurrence of the reverse Diels-Alder reaction. This is a thermally forbidden, photochemically allowed, process, which is made possible by the interaction of the polar zeolite matrix sites with parent NBD and Q radical cations

Un camino hacia la maternidad pospatriarcal

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María Inmaculada Barceló Tous

2016-01-01

Full Text Available Esta es una época de cambios vertiginosos encaminados hacia la equipolencia entre géneros. Sin embargo sigue subyacente una lucha por el poder social. En este choque de fuerzas, el control de la natalidad y el imperium sobre la descendencia son fenómenos a tener muy en cuenta. El presente trabajo trae a colación una dinámica reciente protagonizada por algunas ciudadanas de Estados constitucionales democráticos, que optan por ser madres a través de la reproducción asistida y apuestan por un proyecto familiar sin padre. Pero sobre todo aspira a abrir frentes de reflexión acerca de la uniparentalidad elegida. Este nuevo sistema de parentesco y la transmutación de la familia, ¿ilustran el final o el inicio de una nueva era?

Youth De-Radicalization: A Canadian Framework

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Hafal (Haval Ahmad

2017-09-01

Full Text Available Youth radicalization leading to violence has become a growing fear among Canadians, as terrorist attacks are carried out in Western states. Although Canada has suffered relatively fewer acts of violence, this fear has intensified and a de-radicalization strategy is needed in the Canadian context. In a qualitative case study methodology, interviews were conducted with school counsellors, religious leaders, and academics to explore solutions to youth radicalization. Youth de-radicalization approaches from the United Kingdom were analyzed and found that community-based initiatives were missing from programming. Social identity theory is used to explain that youth join radicalized groups to feel a sense of belonging and have to be provided an alternative and moderate group identity to de-radicalize. This study found youth de-radicalization in Canada is best served through a community collaboration approach.

Peroxyl radical reactions with carotenoids in microemulsions: Influence of microemulsion composition and the nature of peroxyl radical precursor.

Science.gov (United States)

El-Agamey, Ali; McGarvey, David J

2016-01-01

The reactions of acetylperoxyl radicals with different carotenoids (7,7'-dihydro-β-carotene and ζ-carotene) in SDS and CTAC microemulsions of different compositions were investigated using laser flash photolysis (LFP) coupled with kinetic absorption spectroscopy. The primary objective of this study was to explore the influence of microemulsion composition and the type of surfactant used on the yields and kinetics of various transients formed from the reaction of acetylperoxyl radicals with carotenoids. Also, the influence of the site (hydrocarbon phases or aqueous phase) of generation of the peroxyl radical precursor was examined by using 4-acetyl-4-phenylpiperidine hydrochloride (APPHCl) and 1,1-diphenylacetone (11DPA) as water-soluble and lipid-soluble peroxyl radical precursors, respectively. LFP of peroxyl radical precursors with 7,7'-dihydro-β-carotene (77DH) in different microemulsions gives rise to the formation of three distinct transients namely addition radical (λmax=460 nm), near infrared transient1 (NIR, λmax=700 nm) and 7,7'-dihydro-β-carotene radical cation (77DH(•+), λmax=770 nm). In addition, for ζ-carotene (ZETA) two transients (near infrared transient1 (NIR1, λmax=660 nm) and ζ-carotene radical cation (ZETA(•+), λmax=730-740 nm)) are generated following LFP of peroxyl radical precursors in the presence of ζ-carotene (ZETA) in different microemulsions. The results show that the composition of the microemulsion strongly influences the observed yield and kinetics of the transients formed from the reactions of peroxyl radicals (acetylperoxyl radicals) with carotenoids (77DH and ZETA). Also, the type of surfactant used in the microemulsions influences the yield of the transients formed. The dependence of the transient yields and kinetics on microemulsion composition (or the type of surfactant used in the microemulsion) can be attributed to the change of the polarity of the microenvironment of the carotenoid. Furthermore, the nature of

Glutathione as a radical scavenger and the biological consequences of thiyl radical production

International Nuclear Information System (INIS)

Winterbourn, C.C.

1996-01-01

A large number of compounds that have toxic effects can be metabolised to free radicals and secondary reactive oxygen species. These may be directly damaging or affect cell function by altering regulatory mechanisms through changing redox status. Protection is provided by an integrated system of antioxidant defenses. This includes reduced glutathione (GSH), one of the functions of which is as a free radical scavenger. For GSH to be an effective radical scavenging antioxidant, therefore, it must act in concert with superoxide dismutase to remove the superoxide so generated. Superoxide is produced in a variety of metabolic processes. It is also a secondary product of radicals reacting with oxygen either directly or through GSH. The biological reactivity of superoxide has been the subject of much debate ever since the discovery of superoxide dismutase in 1968. It has more recently become apparent that its rapid reaction with nitric oxide to give peroxynitrite, and its ability to reversibly oxidise and inactivate iron sulphur enzymes, contribute to the toxicity of superoxide. Another mechanism that could be important involves addition reactions of superoxide with other radicals to give organic peroxides. This reaction, to form a tyrosine peroxide, has come to authors attention through the study of the scavenging of tyrosyl radicals by GSH. It is also shown that a tyrosine peroxide is a major product of the oxidation of tyrosine by neutrophils

Taking a radical position: Evidence for position specific radical representations in Chinese character recognition using masked priming ERP

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I-Fan eSu

2012-09-01

Full Text Available In the investigation of orthographic representation of Chinese characters, one question that has stimulated much research is whether radicals (character components are specified for spatial position in a character (e.g. Ding, Peng, & Taft, 2004; Tsang & Chen, 2009. Differing from previous work, component or radical position information in this study is conceived in terms of relative frequency across different positions of characters containing it. A lexical decision task in a masked priming paradigm focusing on radicals with preferred position of occurrence was conducted. A radical position that encompasses more characters than other positions was identified to be the preferred position of a particular radical. The prime that was exposed for 96ms might share a radical with the target in the same or different positions. Moreover, the shared radical appeared either in its preferred or non-preferred position in the target. While response latencies only revealed the effect of graphical similarity, both effects of graphical similarity and radical position preference were found in the ERP results. The former effect was reflected in greater positivity in occipital P1 and greater negativity in N400 for radicals in different positions in prime and target characters. The latter effect manifested as greater negativity in occipital N170 and greater positivity in frontal P200 in the same time window elicited by radicals in their non-preferred position. Equally interesting was the reversal of the effect of radical position preference in N400 with greater negativity associated with radicals in preferred position. These findings identify the early ERP components associated with activation of position-specific radical representations in the orthographic lexicon, and reveal the change in the nature of competition from processing at the radical level to the lexical level.

Radical production in biological systems

International Nuclear Information System (INIS)

Johnson, J.R.; Akabani, G.

1994-10-01

This paper describes our effort to develop a metric for radiation exposure that is more fundamental than adsorbed dose and upon which a metric for exposure to chemicals could be based. This metric is based on the production of radicals by the two agents. Radicals produced by radiation in biological systems commonly assumed to be the same as those produced in water despite the presence of a variety of complex molecules. This may explain why the extensive efforts to describe the relationship between energy deposition (track structure) and molecular damage to DNA, based on the spectrum of radicals produced, have not been successful in explaining simple biological effects such as cell killing. Current models assume that DNA and its basic elements are immersed in water-like media and only model the production and diffusion of water-based radicals and their interaction with DNA structures; these models lack the cross sections associated with each macro-component of DNA and only treat water-based radicals. It has been found that such models are not realistic because DNA is not immersed in pure water. A computer code capable of simulating electron tracks, low-energy electrons, energy deposition in small molecules, and radical production and diffusion in water like media has been developed. This code is still in at a primitive stage and development is continuing. It is being used to study radical production by radiation, and radical diffusion and interactions in simple molecular systems following their production. We are extending the code to radical production by chemicals to complement our PBPK modeling efforts. It therefore has been developed primarily for use with radionuclides that are in biological materials, and not for radiation fields

Diseño de un prototipo de bipedestador para pacientes pediátricos con espina bífida

OpenAIRE

Katherine Quiñones-Argote; Aydee Robayo-Torres; Andrés Garcia-Torres

2013-01-01

Antecedentes. La postura bipodal del ser humano resulta de la maduración del sistema neuromotriz y es una necesidad evolutiva que filogenéticamente hace posible la diferenciación de funciones entre miembros superiores e inferiores, condicionando un mayor desarrollo de estas últimas. La posibilidad de bipedestación asistida por dispositivos ergonómicos, que a la vez sean económicos y funcionales, es planteada como un derecho para la población pediátrica con disc...

GRAVIDEZ NA ADOLESCÊNCIA: PERCEPÇÕES, COMPORTAMENTOS E EXPERIÊNCIAS DE FAMILIARES

OpenAIRE

Tereza Alves de Souza; Maria Eliane Maciel de Brito; Amanda Cavalcante Frota; Joyce Mazza Nunes

2012-01-01

El embarazo en la adolescencia es un grave problema social y de salud pública, por las consecuencias a la madre y al concepto. Estudio cualitativo, cuyo objetivo fue aprehender el significado del embarazo en la adolescencia para los familiares. Desarrollado con siete familias de adolescentes embarazadas y/o que tuvieron parto en 2010, asistidas en Centro de Salud de la Familia de Fortaleza-CE, Brasil. Las informaciones fueran buscadas en guión de entrevista semiestructurada, en hogares. Los r...

Chemical repair of trypsin-histidinyl radical

International Nuclear Information System (INIS)

Jovanovic, S.V.; Ruvarac, I.; Jankovic, I.; Josimovic, L.

1991-01-01

Oxyl radicals, such as hydroxyl, alkoxyl and peroxyl, react with biomolecules to produce bioradicals. Unless chemically repaired by suitable antioxidants, these bioradicals form stable products. This leads to loss of biological function of parent biomolecules with deleterious biological results, such as mutagenesis and cancer. Consequently, the understanding of the mechanisms of oxyl radical damage to biomolecules and chemical repair of such damage is crucial for the development of strategies for anticarcinogenesis and radioprotection. In this study the chemical repair of the histidinyl radical generated upon the trichloromethylperoxyl radical reaction with trypsin vas investigated by gamma radiolysis. The trypsin histidinyl radical is a resonance-stabilized heterocyclic free radical which was found to be unreactive with oxygen. The efficacy of the chemical repair of the trypsin-histidinyl radical by endogenous antioxidants which are electron donors (e.g. 5-hydroxytryptophan, uric acid) is compared to that of antioxidants which are H-atom donors (e. g. glutathione). 9 refs., 2 figs., 1 tab

Gnosticism and Radical Feminism

DEFF Research Database (Denmark)

Cahana, Jonathan

2016-01-01

and radical feminism would easily fall under this definition. There is, however, one major difference: since radical feminism is a relatively recent phenomenon which also benefited from modern modes of text production and preservation, almost all of the sources are still with us. This, in turn, may allow us...... to use radical feminism to make certain aspects of ancient Gnosticism re-emerge from their long submersion, provided that enough similarities can be independently drawn between the two phenomena to merit such a comparison. This paper therefore presents a comparison between concepts and positions...

Radical's view of sciences

International Nuclear Information System (INIS)

Mittal, J.P.

2004-01-01

Full text: General concept in radiation biology is that free radicals are highly reactive and they can damage vital cellular molecules leading to injurious effects. However, in this talk, evidence will be presented through the techniques of electron paramagnetic resonance ( EPR ) and pulse radiolysis that free radicals can be highly selective in their reaction with the target molecules. In addition, attempts will be made to present a brief account of emerging scenario of free radical generation, identification and their involvement in radiation damage mechanisms in chemical and biological systems

EPR spin trapping of protein radicals

DEFF Research Database (Denmark)

Davies, Michael Jonathan; Hawkins, Clare Louise

2004-01-01

Electron paramagnetic resonance (EPR) spin trapping was originally developed to aid the detection of low-molecular-mass radicals formed in chemical systems. It has subsequently found widespread use in biology and medicine for the direct detection of radical species formed during oxidative stress...... tumbling radicals are often broad and relatively poor in distinctive features, a number of techniques have been developed that allow a wealth of information to be obtained about the nature, site, and reactions of such radicals. This article summarizes recent developments in this area and reviews selected...... examples of radical formation on proteins....

Fragmentation characteristics of the unstable [CH3 CO][radical sign] radicals generated by neutralization of [CH3CO]+ cations

Science.gov (United States)

Hop, C. E. C. A.; Holmes, J. L.

1991-03-01

The stability and fragmentation characteristics of [CH3 CO][radical sign] radicals, generated by vertical charge exchange between acetyl cations and permanent gases or metal vapours (He, Xe, NO, Cd, Na and K), were examined mass spectrometrically. Two dissociation reactions were observed, the losses of CH[radical sign]3 and H[radical sign]. The H[radical sign] loss reaction, the higher energy dissociation, became of greater importance as the exothermicity of the charge exchange was increased. Based on the analysis of the kinetic energy releases it was concluded that these decompositions arose from the population of two excited states of the [CH3 CO][radical sign] radical.

Reaction between protein radicals and other biomolecules

DEFF Research Database (Denmark)

Østdal, H.; Davies, M.J.; Andersen, Henrik Jørgen

2002-01-01

The present study investigates the reactivity of bovine serum albumin (BSA) radicals towards different biomolecules (urate, linoleic acid, and a polypeptide, poly(Glu-Ala-Tyr)). The BSA radical was formed at room temperature through a direct protein-to-protein radical transfer from H(2)O(2....... Subsequent analysis showed a decrease in the concentration of urate upon reaction with the BSA radical, while the BSA radical in the presence of poly(Glu-Ala-Tyr) resulted in increased formation of the characteristic protein oxidation product, dityrosine. Reaction between the BSA radical and a linoleic acid...

Radical intermediates involved in the bleaching of the carotenoid crocin. Hydroxyl radicals, superoxide anions and hydrated electrons

International Nuclear Information System (INIS)

Bors, W.; Saran, M.; Michel, C.

1982-01-01

The participation of the primary radicals in the bleaching of aqueous solutions of the carotenoid crocin by ionizing radiation was investigated, employing both X-radiolysis and pulse radiolysis. The pulse-radiolytic data demonstrated a very rapid diffusion-controlled attack by both hydroxyl radicals (radicalsOH) and hydrated electrons (e - sub(aq)), while superoxide anions (O 2 - ) did not react at all. The site of the initial reaction of these radicals was not limited to the polyene chromophore. Slower secondary reactions involving crocin alkyl or peroxy radicals contribute mainly to the overall bleaching, in particular during steady-state irradiation. (author)

Formation of long-lived radicals on proteins by radical transfer from heme enzymes--a common process?

DEFF Research Database (Denmark)

Ostdal, H; Andersen, H J; Davies, Michael Jonathan

1999-01-01

concentrations were observed after limited digestion, although this effect was less marked with the HRP/H2O2/BSA system than with Fe(III)Mb/H2O2/BSA, consistent with different modes of radical transfer. More extensive digestion of BSA decreased the radical concentration to levels below those detected with native...... investigated using horseradish peroxidase (HRP)/H2O2, in the presence and absence of added tyrosine. Incubation of HRP with H2O2 and bovine or human serum albumins, in the presence and absence of tyrosine, gave long-lived albumin-derived radicals as detected by EPR spectroscopy. Evidence has been obtained...... for these albumin radicals being located on buried tyrosine residues on the basis of blocking experiments. The effect of protein conformation on radical transfer has been investigated using partial proteolytic digestion prior to protein oxidation. With HRP/H2O2/BSA and Fe(III)Mb/H2O2/BSA increased radical...

Libertad, igualdad, sostenibilidad. Por un ecofeminismo ilustrado

Directory of Open Access Journals (Sweden)

Puleo, Alicia H.

2008-06-01

Full Text Available This article presents the proposal of an enlightened Ecofeminism and defines it as an ethic-political thinking about human relations to Nature. It aims at ecojustice and sustainability, which are characterized through the criticism of prejudice, through the principles of equality and autonomy, and through the nominalist conceptualization of gender, intercultural dialogue and the sensible acceptance of science and technique. The enlightened Ecofeminism universalizes virtues such as caring for the human and non-human Nature, and defends a compassionate moral towards the radical finitude of the world.

En este artículo se presenta la propuesta de un ecofeminismo ilustrado entendido como reflexión ético-política sobre las relaciones de los humanos con la Naturaleza. Orientado a la ecojusticia y la sostenibilidad, el ecofeminismo ilustrado se caracterizaría por la crítica al prejuicio, la defensa de los principios de igualdad y autonomía, la conceptualización nominalista del género, el diálogo intercultural, la aceptación prudente de la ciencia y la técnica, la universalización de las virtudes del cuidado aplicadas a los humanos y al resto de la Naturaleza, y una moral de la compasión frente a la radical finitud del mundo.

REMOCIÓN DE ARSÉNICO ASISTIDA POR OXIDACIÓN UV SOLAR (RAOS EN FOTO-REACTORES TUBULARES DE SECCIÓN SEMICIRCULAR - CINÉTICA DEL CRECIMIENTO DE FLÓCULOS DE Fe(OH3

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Ramiro Escalera Vásquez

2012-01-01

Cálculos de capacidad de tratamiento, en régimen continuo (considerando tiempos de residencia hidráulica iguales a los tiempos de irradiación, demuestran la mayor capacidad del foto-reactor de 71 cm de diámetro, logrando un flujo diario de 190 Lm-2 para una operación de 5 h por día. Desde el punto de vista económico y de su construcción, este foto-reactor es más práctico que los reactores de menor diámetro, por la menor cantidad de accesorios y materiales involucrados.

El problema del derecho a la identidad en el Código Civil y Comercial de la Nación

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José Miguel Cruz

2015-09-01

Full Text Available Este trabajo ha visto la luz con la modesta intención de resaltar uno de los desaciertos que contiene el código civil y comercial en materia de filiación e identidad: la adopción de un sistema que restringe el acceso a la información identificatoria del donante al concebido por las técnicas de reproducción humana asistida. Con apoyo en la legislación y la jurisprudencia pertinente es que se propone una eventual reforma del art. 564 adoptando un régimen más favorable al concebido por las técnicas de referencia en concordancia con el sistema de derechos humanos.

Radical surgery compared with intracavitary cesium followed by radical surgery in cervical carcinoma stage IB

Energy Technology Data Exchange (ETDEWEB)

Tinga, D.J.; Bouma, J.; Aalders, J.G. (Dept. of Obstetrics and Gynaecology, State Univ. Hospital, Groningen (Netherlands)); Hollema, H. (Dept. of Pathology, State Univ. Hospital, Groningen (Netherlands))

1990-01-01

Forty-nine patients aged {le} 45 years, with cervical carcinoma stage IB ({le} 3 cm) were treated with either primary radical surgery (n = 26), or intracavitary irradiation followed by radical surgery (n = 23). With primary surgery, ovarian function had been preserved in 15 of the 25 patients, who were alive and well. Seven of the primary surgery patients were irradiated postoperatively and 2 others with a central recurrence were cured by irradiation. One other patient, who was not irradiated postoperatively, had an intestinal metastasis and died of the disease. If any of the adverse prognostic factors (as reported in the literature) had been considered as an indication for postoperative irradiation, 17 patients instead of 7 would have been irradiated after primary radical surgery. In the comparable group of 23 patients treated by intracavitary irradiation and radical surgery (and in 4 cases postoperative irradiation as well) there was no recurrence. There was no significant statistical difference between the treatment results in the cesium + surgery group and those who underwent primary radical surgery. Young patients with early cervical carcinoma without prognostic indicators for postoperative irradiation can benefit from primary radical surgery, because their ovarian function can be preserved. (authors).

Radical surgery compared with intracavitary cesium followed by radical surgery in cervical carcinoma stage IB

International Nuclear Information System (INIS)

Tinga, D.J.; Bouma, J.; Aalders, J.G.; Hollema, H.

1990-01-01

Forty-nine patients aged ≤ 45 years, with cervical carcinoma stage IB (≤ 3 cm) were treated with either primary radical surgery (n = 26), or intracavitary irradiation followed by radical surgery (n = 23). With primary surgery, ovarian function had been preserved in 15 of the 25 patients, who were alive and well. Seven of the primary surgery patients were irradiated postoperatively and 2 others with a central recurrence were cured by irradiation. One other patient, who was not irradiated postoperatively, had an intestinal metastasis and died of the disease. If any of the adverse prognostic factors (as reported in the literature) had been considered as an indication for postoperative irradiation, 17 patients instead of 7 would have been irradiated after primary radical surgery. In the comparable group of 23 patients treated by intracavitary irradiation and radical surgery (and in 4 cases postoperative irradiation as well) there was no recurrence. There was no significant statistical difference between the treatment results in the cesium + surgery group and those who underwent primary radical surgery. Young patients with early cervical carcinoma without prognostic indicators for postoperative irradiation can benefit from primary radical surgery, because their ovarian function can be preserved. (authors)

Free radicals in an Adamantane matrix. XI. Electron paramagnetic resonance study of conformations in the β-halo-tert-butyl radicals

International Nuclear Information System (INIS)

Lloyd, R.V.; Wood, D.E.

1975-01-01

The β-halo-tert-butyl radicals were prepared by x-irradiation of the corresponding isobutyl halides in an adamantane matrix at 77 0 K and their conformations were determined by analysis of their EPR spectra. The radicals are nonplanar at the radical site, the fluoro and chloro radicals trans eclipsed and the bromo and iodo radicals gauche staggered with respect to the relative orientation of the carbon halogen bond and the direction of the singly occupied orbital. Vibration-rotation motions about the favored conformation are much larger for the fluoro radical than for the others. The rate of interconversion of the inequivalent methylene protons is approximately 1.5 x 10 9 sec -1 for the bromo radical at 202 0 K while it is too slow to measure for the iodo radical at the same temperature. The barrier to interconversion has a lower limit of 3 kcal/mol for the bromo radical and higher than that for the iodo radical. The halogen and proton hfsc in gauss and the g values for the XCH 2 C(CH 3 ) 2 radicals are: 19 F = 103.7, CH 2 = 10.4, CH 3 = 23.3, g = 2.0030 at 214 K; 35 Cl = 19.5, CH 2 = 6.3, CH 3 = 21.1, g = 2.0042 at 215 K; 81 Br = 6.7, CH 2 = 21.4, 42.7, CH 3 = 21.4, g = 2.0010 at 202 K; 127 I = 7.0, CH 2 = 21.9, 43.8, CH 3 = 21.9, g = 2.0009 at 208 K. The fluoro radical decays to nonradical products above 318 0 K, the chloro radical converts to 2-methyl allyl radical above 306 0 K, the bromo radical converts to tert-butyl radical by exchange with a matrix proton (or deuteron) at 209 0 K as does the iodo radical above 225 0 K. Photolysis with a Xe lamp converts the bromo and iodo radicals to nonradical products in less than the experimental time constant of 0.3 sec. The hypothesis is put forward that the nonplanarity and high barrier to rotation observed explain the retention of stereochemical configuration in reactions involving β-chloro, β-bromo, and β-iodo alkyl radicals. (auth)

17.9.3 Radical cations of diazo compounds

Science.gov (United States)

Davies, A. G.

This document is part of Subvolume E2 `Phosphorus-Centered Radicals, Radicals Centered on Other Heteroatoms, Organic Radical Ions' of Volume 26 `Magnetic Properties of Free Radicals' of Landolt-Börnstein Group II `Molecules and Radicals'.

Inhibition of radiation-induced DNA strand breaks by hoechst 33258: OH-radical scavenging and DNA radical quenching

International Nuclear Information System (INIS)

Adhikary, A.; Bothe, E.; Von Sonntag, C.; Adhikary, A.

1997-01-01

The minor-groove-binding dye Hoechst 33258 has been found to protect pBR322 DNA in aqueous solution against radiation-induced single-strand breaks (ssb). This protective effect has been assumed to be largely due to the scavenging of the strand-break-generating OH radicals by Hoechst. From D 37 values for ssb at different Hoechst concentrations the value of the OH radical scavenging constant of DNA-bound Hoechst has been estimated at k Ho/DNA = 2.7 * 10 11 dm 3 mol -1 . This unexpectedly high value has led us to study the reactions of OH radicals with Hoechst in the absence and in the presence of double-stranded calf thymus DNA (ds DNA) by pulse radiolysis, and the formation of radiation-induced ssb by low angle laser light scattering. The D 37 /D 37 0 values at different Hoechst concentrations agree with the values obtained by Martin and al. and demonstrate the protection. However, this protection cannot be explained on the basis of OH radical scavenging alone using the above rate constants. There must, in addition, be some quenching of DNA radicals. Hoechst radicals are formed in the later ms time range, i.e a long time after the disappearance of the OH radicals. This delayed Hoechst radical formation has been assigned to a a reaction of DNA radicals with Hoechst, thereby inhibiting strand breakage. In confirmation, pulse radiolysis of aqueous solution of nucleotides in the presence of Hoechst yields a similar delayed Hoechst radical formation. The data indicate that in DNA the cross-section of this quenching has a diameter of 3 to 4 base pairs per Hoechst molecule. (N.C.)

Radical-Local Teaching and Learning

DEFF Research Database (Denmark)

Hedegaard, Mariane; Chaiklin, Seth

Radical-Local Teaching and Learning presents a theoretical perspective for analyzing and planning educational programmes for schoolchildren. To realize both general societal interests and worthwhile personal development, the content of educational programmes for children must be grounded in the l......Radical-Local Teaching and Learning presents a theoretical perspective for analyzing and planning educational programmes for schoolchildren. To realize both general societal interests and worthwhile personal development, the content of educational programmes for children must be grounded...... radical-local teaching and learning approach. The first half of the book introduces the idea of radical-local teaching and learning and develops the theoretical background for this perspective, drawing on the cultural-historical research tradition, particularly from Vygotsky, El'konin, Davydov......, and Aidarova. The second half of the book addresses the central concern of radical-local teaching and learning - how to relate educational practices to children's specific historical and cultural conditions. The experiment was conducted for an academic year in an afterschool programme in the East Harlem...

Electronic structure of Co islands grown on the {radical}3 x {radical}3-Ag/Ge(111) surface

Energy Technology Data Exchange (ETDEWEB)

Huang, Xiao-Lan; Chou, Chi-Hao; Lin, Chun-Liang; Tomaszewska, Agnieszka; Fu, Tsu-Yi, E-mail: phtifu@phy.ntnu.edu.tw

2011-09-30

By means of room temperature scanning tunneling spectroscopy (RT STS), we have studied the electronic structure of two different Ag/Ge(111) phases as well as Co islands grown on the {radical}3 x {radical}3-Ag/Ge (111) forming either {radical}13 x {radical}13 or 2 x 2 patterns. The spectrum obtained from 4 x 4-Ag/Ge(111) structure shows the existence of a shoulder at 0.7 V which is also present in the electronic structure of the Ge(111)-c2 x 8 and indicates donation of Ge electrons to electronic states of the Ag-driven phase. However, this fact is not supported by the electronic spectrum taken from the {radical}3 x {radical}3-Ag/Ge (111). The complexity of the Co-{radical}13 x {radical}13 islands bonding with the substrate is mirrored by a large number of peaks in their electronic spectra. The spectra obtained from the Co-2 x 2 islands which had grown on the step differ from those taken from Co-2 x 2 islands located along the edge of the terrace by a number of peaks at negative sample bias. This discrepancy is elucidated in terms of dissimilarities of Co-substrate interaction accompanying Co islands growth on different areas of the stepped surface.

Understanding political radicalization: The two-pyramids model.

Science.gov (United States)

McCauley, Clark; Moskalenko, Sophia

2017-04-01

This article reviews some of the milestones of thinking about political radicalization, as scholars and security officials struggled after 9/11 to discern the precursors of terrorist violence. Recent criticism of the concept of radicalization has been recognized, leading to a 2-pyramids model that responds to the criticism by separating radicalization of opinion from radicalization of action. Security and research implications of the 2-pyramids model are briefly described, ending with a call for more attention to emotional experience in understanding both radicalization of opinion and radicalization of action. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Orgasm after radical prostatectomy

NARCIS (Netherlands)

Koeman, M; VanDriel, MF; Schultz, WCMW; Mensink, HJA

Objective To evaluate the ability to obtain and the quality of orgasm after radical prostatectomy, Patients and methods The orgasms experienced after undergoing radical prostatectomy were evaluated in 20 men (median age 65 years, range 56-76) using a semi-structured interview and a self-administered

O Behaviorismo Radical como filosofia da mente Radical Behaviorism as philosophy of mind

Directory of Open Access Journals (Sweden)

Carlos Eduardo Lopes

2003-01-01

Full Text Available O Behaviorismo Radical de B. F. Skinner é constantemente acusado de eliminar a mente de sua explicação do comportamento humano. Uma análise do livro The Concept of Mind, de Gilbert Ryle, sugere a possibilidade de defender a existência de uma mente relacional, diferente da categoria de existência da mente defendida em interpretações cartesianas (mente substancial. A análise de alguns textos de Skinner sugere que o conceito de uma mente relacional também pode ser defendido no Behaviorismo Radical. Esse fato, culminaria na possibilidade de que, além de filosofia da Ciência do Comportamento, o Behaviorismo Radical, também pode ser uma filosofia da mente, o que traria conseqüências ao estudo e à aplicação da Análise do Comportamento.B. F. Skinner's Radical Behaviorism has been repeatedly accused of eliminating the mind from its explanation of human behavior. An analysis of Gilbert Ryle's book, The Concept of Mind, suggests the possibility of defending the existence of a relational mind, different from the category of existence of mind defended in Cartesian interpretations (substantial mind. The analysis of some texts of Skinner suggests that the concept of a relational mind can also be defended in Radical Behaviorism. This fact would lead to the possibility that, beyond a philosophy of Behavior Science, Radical Behaviorism may also be a philosophy of mind, which would bring consequences to the study and application of Analysis of Behavior.

Muonium radicals in benzene-styrene mixtures

International Nuclear Information System (INIS)

Ng, B.W.; Stadlbauer, J.W.; Walker, D.C.

1984-01-01

Muonium radicals were observed through their μ + SR precession frequencies in high transverse magnetic fields in pure benzene, pure styrene and their mixtures, all as liquids at room temperature. In benzene-styrene mixtures, the radicals obtained in each pure liquid are both present, so no slow (10 -9 -10 -5 s) intermolecular exchange occurs; but strong selectivity was found with the formation of the radical from styrene being about eight-times more probable than the radical from benzene. (Auth.)

Laparoscopic radical cystectomy: key points

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D. V. Perlin

2018-01-01

Full Text Available Background. Radical cystectomy remains the golden standard for treatment of muscle invasive bladder cancer. Objective: to duplicate with highest accuracy the open radical cystectomy procedure, which we successfully utilized earlier in our clinic, in the of laparoscopic conditions in order to preserve the advantages of minimally invasive procedures and retain the reliability of the tried and tested open surgery.Materials and methods. In the report were included 35 patients (27 men and 8 women with bladder cancer, who underwent laparoscopic radical cystectomy in Volgograd Regional Center of Urology and Nephrology between April 2013 and March 2016. Only the patients who had been submitted to full intracorporal ileal conduits were included.Results. The mean operative time was 378 minutes, the mean blood loss was 285 millilitres, the mean length of hospital stay was 12.4 days, only 20 % of patients required the narcotic anesthetics. The postoperative complication rate was 11.4 %. However, the majority of the patients were successfully treated with minimally invasive procedures. Generally, our results were similar to other reported studies.Conclusion. Laparoscopic radical cystectomy is a safe and efficient modality of treatment of bladder cancer. However, it needs more procedures and longer observation period to establish laparoscopic radical cystectomy as an alternative to open radical cystectomy.

Effects of Molecular Iodine and 4-tert-Butylcatechol Radical Inhibitor on the Radical Polymerization of Styrene

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Mojtaba Bozorg

2017-05-01

Full Text Available The presence of molecular iodine was studied in relation the molecular weight and molecular weight distribution of polystyrene, produced by radical poly merization. Radical polymerization of styrene initiated by 2,2׳-azobisisobutyronitrile (AIBN was performed at 70°C in the presence of molecular iodine. The synthesized polymers were characterized by gel permeation chromatography (GPC and proton- nuclear magnetic resonance (1H NMR techniques. The results of these reactions including conversion data, number-average molecular weight and molecular weight distribution were compared with those obtained for styrene radical polymerization initiated by AIBN at the same temperature in the absence of molecular iodine. It was found that the presence of iodine had a profound effect on the molecular weight and its distribution in the produced polystyrene. This was attributed to the ability of iodine to control the polymerization of styrene initiated by AIBN via reverse iodine transfer polymerization (RITP mechanism. The polymer produced by this method had a molecular weight of 10600 g/mol with a molecular weight polydispersity index of 1.3. Due to the importance of induction period in reverse iodine transfer radical polymerization, increasing the temperature to 120°C during the induction period resulted in shorter induction periods and the produced species led to better control of the molecular weight. Also, due to the role of iodine molecules as a radical inhibitor, the presence of a secondary radical inhibitor, i.e. 4-tert-butylcatechol, along with the iodine was investigated in radical polymerization of polystyrene initiated by AIBN. It was observed that the secondary radical inhibitor prevented the consumption of the iodine molecules by the radicals produced from decomposition of the AIBN initiator; therefore, alkyl halides were not produced during the induction period.

La vida humana como principio interpretativo radical en la filosofía de Ortega y Gasset

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Antonio Gutiérrez-Pozo

2012-12-01

Full Text Available En este artículo presentamos el concepto de vida humana como texto eterno en el pensamiento de Ortega y sus consecuencias para el problema de la interpretación. La filosofía de la razón vital de Ortega se fundamenta en el concepto de vida humana como realidad radical y principio interpretativo universal, y por esta razón se presenta desde el principio como una filosofía hermenéutica de la vida y no como una reducción hacia la conciencia trascendental. Esta hermenéutica se practica especialmente en el ámbito del arte. Pero para Ortega todo texto es hermenéutico y necesita por tanto la interpretación, porque ningún texto posee en sí mismo su verdad.

Free radical scavengers from the aerial parts of Grammosciadium platycarpum Boiss. & Hausskn. (Apiaceae and GC-MS analysis of the essential oils from its fruits Substâncias eliminadoras de radicais livres das partes aéreas de Grammosciadium platycarpum Boiss. & Hausskn. (Apiaceae e análise por CG-MS dos óleos essenciais de seus frutos

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Hossein Nazemiyeh

2009-12-01

Full Text Available Grammosciadium platycarpum Boiss. & Hausskn (Apiaceae is one of three endemic Iranian species of the genus Grammosciadium DC. Consumption of the aerial parts of this plant affects renal function and causes diuresis. In the DPPH assay the methanol extract showed the highest level of free radical scavenging activity (RC50 = 1.196 x 10-2 mg/mL among the extracts. Reversed-phase preparative HPLC analyses of the methanol extract yielded nine flavonoids, which were responsible for the free radical scavenging activity of the MeOH extract. The GC-MS analyses of the essential oils led to the identification of 29 terpenoids, mainly monoterpenes (non-oxygenated 3.97% and oxygenated 77.49% accounting for over 96% of the total oils.Grammosciadium platycarpum Boiss. & Hausskn (Apiaceae é uma das três espécies endémicas no Irã do gênero Grammosciadium DC. Consumo da parte aérea da planta afeta a função renal e causa diurese. No ensaio por DPPH o extrato metanólico apresentou o maior nível de atividade de antioxidante por radicais livres (RC50 = 1,196 x 10-2 mg/mL entre os extratos. Análises por HPLC preparativa de fase reversa do extrato metanólico resultou no isolamento de nove flavonóides, os quais foram responsáveis pela atividade de antioxidante do extrato metanólico. A análises por CG-EM dos óleos essenciais levou à identificação de 29 terpenóides, principalmente monoterpenos (não-oxigenados 3,97% e oxigenados, 77,49%, os quais representam mais de 96% do total de óleos.

Modelo Funcional de un Gestor de Herramientas de Mecanizado Functional Model of Cutting Tool Management

OpenAIRE

Amparo Meseguer; Francisco González

2006-01-01

En este trabajo se propone un modelo funcional para un gestor de herramientas de mecanizado, integrado con la Planificación de Procesos Asistida por Ordenador (CAPP) y la programación de la producción. El modelo propuesto está basado en la capacidad de CAPP para generar alternativas de herramientas en las operaciones de mecanizado. El gestor resuelve las interferencias entre las herramientas, de forma que cada operación dispone de un conjunto de alternativas de herramientas compatibles con la...

Efectos jurídicos de la regulación del convenio de maternidad subrogada en el libro de familia del Código Civil - Huánuco-2014

OpenAIRE

Schult Echevarría, Juan Carlos

2015-01-01

La presente investigación tuvo el objetivo de identificar los efectos jurídicos que se originan del convenio de maternidad subrogada en el Libro de Familia del Código Civil, en los sujetos que utilizan técnicas de reproducción asistida. El diseño fue no experimental con 71 abogados civilistas seleccionados por muestreo probabilístico, aleatorio simple, a quienes se aplicó satisfactoriamente una encuesta estructurada. Los resultados arribados, luego de análisis inferencial, se estable en que s...

Radical chemistry of artemisinin

Energy Technology Data Exchange (ETDEWEB)

Denisov, Evgenii T; Solodova, S L; Denisova, Taisa G [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

2011-12-29

The review summarizes physicochemical characteristics of the natural sesquiterpene peroxide artemisinin. The kinetic schemes of transformations of artemisinin radicals under anaerobic conditions are presented and analyzed. The sequence of radical reactions of artemisinin in the presence of oxygen is considered in detail. Special emphasis is given to the intramolecular chain oxidation resulting in the transformation of artemisinin into polyatomic hydroperoxide. The kinetic characteristics of elementary reaction steps involving alkyl, alkoxyl, and peroxyl radicals generated from artemisinin are discussed. The results of testing of artemisinin and its derivatives for the antimalarial activity and the scheme of the biochemical synthesis of artemisinin in nature are considered.

Radical chemistry of artemisinin

Science.gov (United States)

Denisov, Evgenii T.; Solodova, S. L.; Denisova, Taisa G.

2010-12-01

The review summarizes physicochemical characteristics of the natural sesquiterpene peroxide artemisinin. The kinetic schemes of transformations of artemisinin radicals under anaerobic conditions are presented and analyzed. The sequence of radical reactions of artemisinin in the presence of oxygen is considered in detail. Special emphasis is given to the intramolecular chain oxidation resulting in the transformation of artemisinin into polyatomic hydroperoxide. The kinetic characteristics of elementary reaction steps involving alkyl, alkoxyl, and peroxyl radicals generated from artemisinin are discussed. The results of testing of artemisinin and its derivatives for the antimalarial activity and the scheme of the biochemical synthesis of artemisinin in nature are considered.

Radical chemistry of artemisinin

International Nuclear Information System (INIS)

Denisov, Evgenii T; Solodova, S L; Denisova, Taisa G

2010-01-01

The review summarizes physicochemical characteristics of the natural sesquiterpene peroxide artemisinin. The kinetic schemes of transformations of artemisinin radicals under anaerobic conditions are presented and analyzed. The sequence of radical reactions of artemisinin in the presence of oxygen is considered in detail. Special emphasis is given to the intramolecular chain oxidation resulting in the transformation of artemisinin into polyatomic hydroperoxide. The kinetic characteristics of elementary reaction steps involving alkyl, alkoxyl, and peroxyl radicals generated from artemisinin are discussed. The results of testing of artemisinin and its derivatives for the antimalarial activity and the scheme of the biochemical synthesis of artemisinin in nature are considered.

Radical chemistry of artemisinin

Energy Technology Data Exchange (ETDEWEB)

Denisov, Evgenii T; Solodova, S L; Denisova, Taisa G [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

2010-12-29

The review summarizes physicochemical characteristics of the natural sesquiterpene peroxide artemisinin. The kinetic schemes of transformations of artemisinin radicals under anaerobic conditions are presented and analyzed. The sequence of radical reactions of artemisinin in the presence of oxygen is considered in detail. Special emphasis is given to the intramolecular chain oxidation resulting in the transformation of artemisinin into polyatomic hydroperoxide. The kinetic characteristics of elementary reaction steps involving alkyl, alkoxyl, and peroxyl radicals generated from artemisinin are discussed. The results of testing of artemisinin and its derivatives for the antimalarial activity and the scheme of the biochemical synthesis of artemisinin in nature are considered.

Oxygen free radicals in rheumatoid arthritis

NARCIS (Netherlands)

P. Biemond (Pieter)

1986-01-01

textabstractCurrent knowledge strongly suggests that oxygen free radicals are involved in the pathogenesis of RA. Additional information about the mechanism of free radical attack is necessary in order to find out if interaction with the mechanism of free radical damage can be used in the treatment

Free radicals in health and disease

International Nuclear Information System (INIS)

Gonet, B.

1993-01-01

Free radicals appear in the cells as the result of exogenic factors (ionizing radiation, UV) or reactions naturally occurring in the cell. Free radical reactions may cause destruction of macromolecules (DNA, lipids, proteins). Free radical pathology is important in many diseases and aging processes in organisms

Resección microquirúrgica estereotáxica de tumores intracraneales guiada por imagen y asistida por computadora

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Gerardo López Flores

2000-12-01

Full Text Available Se reporta que la orientación espacial durante la microcirugía, constituye un elemento indispensable. Se demuestra esta aplicación de la cirugía estereotáxica en el Centro Internacional de Restauración Neurológica (CIREN de mayo de 1994 a febrero de 1998, al describir la realización de 65 intervenciones microquirúrgicas en condiciones estereotáxicas, a 62 pacientes con tumores cerebrales intracraneales. El proceder se dividió en 3 etapas: adquisición de la imagen, tomografía axial computadorizada, planificación quirúrgica, con sistema de planeamiento STASSIS y procederes microquirúrgicos, que incluyeron los sistemas estereotáxicos: Leksell, Micromar y Estereoflex. Del total, 27 de estos pacientes presentaron tumores gliales, 33 no gliales y sólo 2 lesiones no neoplásicas de localización y tamaño variados. Se realizaron 30 resecciones totales. La morbilidad quirúrgica fue mínima y no hubo mortalidad quirúrgica. Las principales ventajas del método son: localización exacta de la craneotomía, fácil orientación espacial, facilidad para distinguir los límites entre el tumor y el tejido sano. Se verificó la aplicabilidad del Estereoflex a la microcirugía cerebralIt is reported that spatial guidance during microsurgery is an essential element. This application of stereotaxic surgery is shown at the International Center of Neurological Restoration (CIREN, in Spanish from May, 1994, to February, 1998, on describing the performance of 65 microsurgical procedures under stereotaxic conditions among 62 patients with cerebral intracranial tumors. The procedure was divided into 3 stages: image adquisition, CAT, surgical planning , with STASSIS planning system, and microsurgical procedures that included the Leksell, Micromar and Esteroflex stereotaxic systems. 27 of the total of patients presented glial tumors; 33, non-glial; and only 2 non-neoplastic lesions of diverse localization and size. 30 total resections were made. Surgical morbidity was minimum and there was no surgical mortality. The main advantages of this method are: exact localization of the craniotomy, easy spatial guidance, and the opportunity to distinguish the limits between the tumor and the sound tissue. The possibility to apply Esteroflex to cerebral microsurgery was demonstrated

Free radicals in wood induced by γ-radiation

International Nuclear Information System (INIS)

Xu Honglin; Zhang Wenhui

1994-01-01

The free radicals in wood induced by γ-radiation were studied by electron spin resonance. The fine structure of the ESR signal from sawdust samples irradiated could be resolved into various radicals. These free radicals have a very long lifetime. The major spectrum for the free radicals will exponentially increased along with the radiation dose according to Y 1-Exp(-α a D). The intensity of radiation radicals is dependent on tree species. The stronger the intensity of mechanic free radicals is, the stronger the intensity of radiation free radicals

Colonización radical por endófitos fúngicos en Trithrinax campestris (Arecaceae de ecosistemas semiáridos del centro de Argentina Root colonization by fungal endophytes in Trithrinax campestris (Arecaceae from semiarid ecosystems from Central Argentine

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Mónica A Lugo

2011-12-01

Full Text Available En ecosistemas áridos y semiáridos las raíces de las plantas suelen formar simbiosis con hongos, los que les proporcionan nutrientes y agua. Poco se conoce sobre los hongos asociados a palmeras nativas y cómo éstos podrían estar relacionados entre ellos. Se describe y cuantifica la colonización radical de los simbiontes de Trithrinax campestris en poblaciones leve y fuertemente afectadas por el fuego. T. campestris fue colonizada por hongos micorrícico-arbusculares (HMA y endófitos septados oscuros (ESO. La colonización por HMA fue del tipo intermedio entre los tipos Arum y Paris. La colonización por HMA y ESO y la producción de pelos radicales, presentó diferencias entre las poblaciones estudiadas. Los resultados sugieren que en T. campestris la relación entre hongos simbiontes/producción de pelos radicales podrían estar relacionada con su alta tolerancia al fuego y la aridez.In arid and semiarid ecosystems, roots frequently form symbiosis with fungi that provides access to nutrients and water. Knowledge regarding the study of fungal symbionts colonizing native palms roots is still scarce. We described, quantified and compared fungal colonization in roots of Trithrinax campestris from two environmental situations: population with weak-burning-signs and population with strong-burning-signs. T. campestris was colonized by arbuscular-mycorrhizal-fungi (AMF and dark-septate-endophytes (DSE. AMF colonization was an intermediate type between Arum and Paris. The AMF and DSE colonization and root hair production differed between populations. Our results suggest that in T. campestris the relation between fungal-symbionts and root-hair-production might be related to tolerance to burning and aridity.

Radical-Local Teaching and Learning

DEFF Research Database (Denmark)

Hedegaard, Mariane; Chaiklin, Seth

radical-local teaching and learning approach. The first half of the book introduces the idea of radical-local teaching and learning and develops the theoretical background for this perspective, drawing on the cultural-historical research tradition, particularly from Vygotsky, El'konin, Davydov......, and Aidarova. The second half of the book addresses the central concern of radical-local teaching and learning - how to relate educational practices to children's specific historical and cultural conditions. The experiment was conducted for an academic year in an afterschool programme in the East Harlem......Radical-Local Teaching and Learning presents a theoretical perspective for analyzing and planning educational programmes for schoolchildren. To realize both general societal interests and worthwhile personal development, the content of educational programmes for children must be grounded...

What is Radical Behaviorism? A Review of Jay Moore's Conceptual Foundations of Radical Behaviorism

Science.gov (United States)

Baum, William M

2011-01-01

B. F. Skinner founded both radical behaviorism and behavior analysis. His founding innovations included: a versatile preparation for studying behavior; explicating the generic nature of stimulus and response; a pragmatic criterion for defining behavioral units; response rate as a datum; the concept of stimulus control; the concept of verbal behavior; and explicating the explanatory power of contingencies. Besides these achievements, however, Skinner also made some mistakes. Subsequent developments in radical behaviorist thought have attempted to remedy these mistakes. Moore's book presents a “party line” version of radical behaviorism. It focuses narrowly on a few of Skinner's concepts (mostly mentalism and verbal behavior) and contains no criticism of his mistakes. In fact, Moore adds a few mistakes of his own manufacture; for example, he insists that the mental realm does not exist—an unprovable and distracting assertion. The book's portrayal of behavior analysis would have been current around 1960; it mentions almost none of the developments since then. It also includes almost no developments in radical behaviorism since Skinner. Moore's book would give an unwary reader a highly distorted picture of contemporary behavior analysis and radical behaviorism.

Orthographic Skills Important to Chinese Literacy Development: The Role of Radical Representation and Orthographic Memory of Radicals

Science.gov (United States)

Yeung, Pui-sze; Ho, Connie Suk-han; Chan, David Wai-ock; Chung, Kevin Kien-hoa

2016-01-01

A 3-year longitudinal study among 239 Chinese students in Grades 2-4 was conducted to investigate the relationships between orthographic skills (including positional and functional knowledge of semantic radicals and phonetic radicals, and orthographic memory of radicals) and Chinese literacy skills (word reading, word spelling, reading…

The Games Radicals Play: Special Issue on Free Radicals and Radical Ions

Directory of Open Access Journals (Sweden)

John C. Walton

2015-02-01

Full Text Available Chemistry and Physics have aptly been described as “most excellent children of Intellect and Art” [1]. Both these “children” engage with many playthings, and molecules rank as one of their first favorites, especially radicals, which are amongst the most lively and exciting. Checking out radicals dancing to the music of entropy round their potential energy ballrooms is surely both entertaining and enlightening. Radicals’ old favorite convolutions are noteworthy, but the new styles, modes and arrangements appearing on the scene are even more interesting. Some of these are ephemeral and enjoy only a brief appearance, others are retro-types reappearing in new guises, still others are genuinely new and “go viral” in the scientific world. This Special Issue of Molecules contains the observations and reflections of a select group of chemists and physicists fascinated by this spectacle. It contains an eclectic mix reflecting on new modes and advances as well as on permutations and combinations that revive mature themes. [...

Radical-pair based avian magnetoreception

Science.gov (United States)

Procopio, Maria; Ritz, Thorsten

2014-03-01

Behavioural experiments suggest that migratory birds possess a magnetic compass sensor able to detect the direction of the geomagnetic. One hypothesis for the basis of this remarkable sensory ability is that the coherent quantum spin dynamics of photoinduced radical pair reactions transduces directional magnetic information from the geomagnetic field into changes of reaction yields, possibly involving the photoreceptor cryptochrome in the birds retina. The suggested radical-pair based avian magnetoreception has attracted attention in the field of quantum biology as an example of a biological sensor which might exploit quantum coherences for its biological function. Investigations on such a spin-based sensor have focussed on uncovering the design features for the design of a biomimetic magnetic field sensor. We study the effects of slow fluctuations in the nuclear spin environment on the directional signal. We quantitatively evaluate the robustness of signals under fluctuations on a timescale longer than the lifetime of a radical pair, utilizing two models of radical pairs. Our results suggest design principles for building a radical-pair based compass sensor that is both robust and highly directional sensitive.

Planeación asistida por computadora del proceso tecnológico de ensamble.

Directory of Open Access Journals (Sweden)

L. L. Tomás García

2008-01-01

Full Text Available El presente trabajo está dedicado a la optimización bajo criterios múltiples de la planificación de procesos de ensamble mecánico a partir de su modelo geométrico tridimensional. Se soporta sobre un enfoque que integra tanto información geométrica como restricciones tecnológicas del proceso de ensamble. En el desarrollo de la misma quedó demostrado, que una vez conocido el modelo geométrico tridimensional de un ensamble, la aplicación de criterios tecnológicos y geométricos al proceso inverso de desensamble y su posterior tratamiento con métodos evolutivos, genera planes deensamble mecánico próximos a los óptimos de acuerdo al sistema de preferencias del decisor. La integración de la información permite disminuir el número de secuencias a evaluar y de elementos a procesar, con lo que se evita la generación y evaluación de todas las secuencias posibles con la consecuente disminución del tiempo de procesamiento. Como resultado de la aplicación del modelo integrado propuesto, se obtiene la planificación del proceso de ensamblemecánico con una reducción del tiempo de ensamble debido a que en las secuencias obtenidas se reduce el número de cambios de dirección de ensamble, los cambios de herramientas y de puestos de trabajo, así como se minimiza la distancia a recorrer debido al cambio de puestos de trabajo. Esto se logra mediante un modelo de optimización multiobjetivo basado en algoritmos genéticos.This work deals with the combinatorial problem of generating and optimizing technologically feasible assembly sequences and process planning involving tools and work places. The assembly sequences and related technological decisions are obtained from a 3D model of the assembled parts based on mating conditions along with a set of technological criteria, which allows automatically analyzing and generating the sequences. The generated assembly sequences are pre-processed and optimized for the assembly Process Planning using Genetic Algorithms. This approach integrates the geometric and technological information of the assembly process, which allows reducing the number of elements and sequences to be processed with the consequent processing time and cost reduction.

Proyecto de investigación aplicada: Introducción a la modelación asistida de sistemas de distribución de agua (MASDA. Caso de estudio: campo/escuela Scout de Costa Rica

Directory of Open Access Journals (Sweden)

Maikel Méndez

2007-05-01

Full Text Available En la actualidad, el constante crecimiento y expansión que experimentan los centros urbanos ha aplicado gran presión sobre los sistemas de abastecimiento y distribución de agua para consumo humano. Los bajos niveles de eficiencia que muchos administradores de sistemasde distribución de agua (ASDA exhiben tienden a agudizar este problema. A través de herramientas de modelación asistida de sistemas de distribución de agua (MASDA, es posible generar un mayor conocimiento sobre la naturaleza y posibilidades de cada sistema. Como caso de estudio, CIVCO/ITCR, analizó la situación del sistema de distribución de agua potable del campo/escuela Scout de Costa Rica. Al identificarse deficiencias irremediables, se decidió diseñar un nuevo sistema que pueda afrontar adecuadamente una ocupación máxima de 280 personas durante un evento crítico de 8 días. Una vez definidos los patrones de diseño, se evalúan diversos escenarios de modelación a través de EPANet 2.0. La información arrojadaindica que los supuestos originales de diseño son adecuados y el sistema presenta condiciones estables de flujo uniforme durante todo el período de modelación. Por otro lado, la concentración de cloro residual en el sistema llega a estabilizarse después de pasado del período de ocupación máxima. El proyecto MASDA seguirá prestando en el futuro asesoramiento y apoyo tecnológico a los administradores de sistemas de distribución de agua, y les permitirá servir de una forma eficiente, constante y confiable a las comunidades bajo su administración, al tiempo que se reduce el impacto sobre las fuentes de producción.

Radically enhanced molecular recognition

KAUST Repository

Trabolsi, Ali

2009-12-17

The tendency for viologen radical cations to dimerize has been harnessed to establish a recognition motif based on their ability to form extremely strong inclusion complexes with cyclobis(paraquat-p-phenylene) in its diradical dicationic redox state. This previously unreported complex involving three bipyridinium cation radicals increases the versatility of host-guest chemistry, extending its practice beyond the traditional reliance on neutral and charged guests and hosts. In particular, transporting the concept of radical dimerization into the field of mechanically interlocked molecules introduces a higher level of control within molecular switches and machines. Herein, we report that bistable and tristable [2]rotaxanes can be switched by altering electrochemical potentials. In a tristable [2]rotaxane composed of a cyclobis(paraquat-p-phenylene) ring and a dumbbell with tetrathiafulvalene, dioxynaphthalene and bipyridinium recognition sites, the position of the ring can be switched. On oxidation, it moves from the tetrathiafulvalene to the dioxynaphthalene, and on reduction, to the bipyridinium radical cation, provided the ring is also reduced simultaneously to the diradical dication. © 2010 Macmillan Publishers Limited. All rights reserved.

Radically enhanced molecular recognition

KAUST Repository

Trabolsi, Ali; Khashab, Niveen M.; Fahrenbach, Albert C.; Friedman, Douglas C.; Colvin, Michael T.; Coti, Karla K.; Bení tez, Diego S.; Tkatchouk, Ekaterina; Olsen, John Carl; Belowich, Matthew E.; Carmieli, Raanan; Khatib, Hussam A.; Goddard, William Andrew III; Wasielewski, Michael R.; Stoddart, Fraser Fraser Raser

2009-01-01

The tendency for viologen radical cations to dimerize has been harnessed to establish a recognition motif based on their ability to form extremely strong inclusion complexes with cyclobis(paraquat-p-phenylene) in its diradical dicationic redox state. This previously unreported complex involving three bipyridinium cation radicals increases the versatility of host-guest chemistry, extending its practice beyond the traditional reliance on neutral and charged guests and hosts. In particular, transporting the concept of radical dimerization into the field of mechanically interlocked molecules introduces a higher level of control within molecular switches and machines. Herein, we report that bistable and tristable [2]rotaxanes can be switched by altering electrochemical potentials. In a tristable [2]rotaxane composed of a cyclobis(paraquat-p-phenylene) ring and a dumbbell with tetrathiafulvalene, dioxynaphthalene and bipyridinium recognition sites, the position of the ring can be switched. On oxidation, it moves from the tetrathiafulvalene to the dioxynaphthalene, and on reduction, to the bipyridinium radical cation, provided the ring is also reduced simultaneously to the diradical dication. © 2010 Macmillan Publishers Limited. All rights reserved.

Formation and spectroscopy of {alpha}-muoniated radicals

Energy Technology Data Exchange (ETDEWEB)

McKenzie, I.; Brodovitch, J.C.; Ghandi, K.; Kecman, S.; Percival, P.W

2003-02-01

Several novel {alpha}-muoniated radicals have been produced by the reaction of muonium with compounds containing diazo, isocyanate or carbene functional groups. In {alpha}-muoniated radicals the muon is attached directly to the radical centre; they can be formed either directly or indirectly via a {beta}-muoniated radical intermediate. The hyperfine coupling constants of the resulting radicals have been measured by transverse field muon spin rotation and muon avoided level-crossing resonance. The effect of muonium substitution was investigated for cases where ESR data are available for comparison.

Formation and spectroscopy of α-muoniated radicals

International Nuclear Information System (INIS)

McKenzie, I.; Brodovitch, J.C.; Ghandi, K.; Kecman, S.; Percival, P.W.

2003-01-01

Several novel α-muoniated radicals have been produced by the reaction of muonium with compounds containing diazo, isocyanate or carbene functional groups. In α-muoniated radicals the muon is attached directly to the radical centre; they can be formed either directly or indirectly via a β-muoniated radical intermediate. The hyperfine coupling constants of the resulting radicals have been measured by transverse field muon spin rotation and muon avoided level-crossing resonance. The effect of muonium substitution was investigated for cases where ESR data are available for comparison

Semantic Radicals Contribute More Than Phonetic Radicals to the Recognition of Chinese Phonograms: Behavioral and ERP Evidence in a Factorial Study

Directory of Open Access Journals (Sweden)

Xieshun Wang

2017-12-01

Full Text Available The Chinese phonograms consist of a semantic radical and a phonetic radical. The two types of radicals have different functional contributions to their host phonogram. The semantic radical typically signifies the meaning of the phonogram, while the phonetic radical usually contains a phonological clue to the phonogram’s pronunciation. However, it is still unclear how they interplay with each other when we attempt to recognize a phonogram because previous studies rarely manipulated the functionality of the two types of radicals in a single design. Using a full factorial design, the present study aimed to probe this issue by directly manipulating the functional validity of the two types of radicals in a lexical decision task with both behavioral and event-related potential (ERP measurements. The results showed that recognition of phonograms which were related to their semantic radicals in meaning took a shorter reaction time, showed a lower error rate, and elicited a smaller P200 and a larger N400 than did recognition of those which had no semantic relation with their semantic radicals. However, the validity of phonetic radicals did not show any main effect or interaction with that of semantic radicals on either behavioral or ERP measurements. These results indicated that semantic radicals played a dominant role in the recognition of phonograms. Transparent semantic radicals, which provide valid semantic cues to phonograms, can facilitate the recognition of phonograms.

Pyrimidine nucleobase radical reactivity in DNA and RNA

Science.gov (United States)

Greenberg, Marc M.

2016-11-01

Nucleobase radicals are major products of the reactions between nucleic acids and hydroxyl radical, which is produced via the indirect effect of ionizing radiation. The nucleobase radicals also result from hydration of cation radicals that are produced via the direct effect of ionizing radiation. The role that nucleobase radicals play in strand scission has been investigated indirectly using ionizing radiation to generate them. More recently, the reactivity of nucleobase radicals resulting from formal hydrogen atom or hydroxyl radical addition to pyrimidines has been studied by independently generating the reactive intermediates via UV-photolysis of synthetic precursors. This approach has provided control over where the reactive intermediates are produced within biopolymers and facilitated studying their reactivity. The contributions to our understanding of pyrimidine nucleobase radical reactivity by this approach are summarized.

Cálculo dos custos do reprocessamento de pinças de uso único utilizadas em cirurgia vídeo-assistida Cálculo de los costos del reprocesamiento de pinzas de uso único utilizadas en cirugía video-asistida Calculation of the reprocessing costs of single-use tongs used in video-assisted surgeries

Directory of Open Access Journals (Sweden)

Eliane Molina Psaltikidis

2006-06-01

Full Text Available O trabalho objetivou desenvolver proposta metodológica para cálculo dos custos do reprocessamento de pinças de cirurgia vídeo-assistida de uso único. O reuso freqüente desses artigos ocorre pelo alto custo, entretanto, poucos estudos foram desenvolvidos a respeito desse enfoque. Elaborou-se um fluxograma com cada fase de reprocessamento, permitindo identificação dos componentes dos custos quanto à mão-de-obra, materiais e gastos indiretos. Pautado nesses dados, pôde-se construir a proposta metodológica para o cálculo de custos, baseada no método de custeio por absorção, incluindo a planilha para coleta de dados.El trabajo tuvo como objetivo desarrollar propuesta metodológica para el cálculo de los costos del reprocesamiento de pinzas de cirugía video-asistida de uso único. El uso frecuente de esos artículos ocurre por el alto costo, no obstante, pocos estudios fueron desarrollados respecto a ese enfoque. Se elaboró un fluxograma con cada fase del reprocesamiento, permitiendo la identificación de los componentes de los costos en cuanto a la mano de obra, materiales y gastos indirectos. Teniendo como pauta esos datos, se puede construir la propuesta metodológica para el cálculo de costos, con base en el método de costeo por absorción, incluyendo la planilla para recolección de datos.The frequent reuse of disposable forceps instruments is justified by their high cost. However, few studies have been carried out on this topic. The objective of this study was to develop a methodological proposal for calculating the reprocessing costs for these instruments used in video-assisted surgery. A flowchart was developed for each phase of the reprocessing. This allowed subsequent identification of the cost components in terms of labor, materials and indirect expenses. From these data, a methodological proposal for cost calculation could be created, based on the Full Absorption Costing Method, including the spreadsheet for data

Quantification of hydroxyl radical produced during phacoemulsification.

Science.gov (United States)

Gardner, Jonathan M; Aust, Steven D

2009-12-01

To quantitate hydroxyl radicals produced during phacoemulsification with various irrigating solutions and conditions used in cataract surgery. Chemistry and Biochemistry Department, Utah State University, Logan, Utah, USA. All experiments were performed using an Infiniti Vision System phacoemulsifier with irrigation and aspiration. Hydroxyl radicals were quantitated using electron spin resonance spectroscopy and a spectrophotometric assay for malondialdehyde, which is formed by the oxidation of deoxyribose by the hydroxyl radical. Hydroxyl radical production increased during longitudinal-stroking phacoemulsification as power levels were increased in a nonlinear, nonexponential fashion. The detection of hydroxyl radical was reduced in irrigating solutions containing organic molecules (eg, citrate, acetate, glutathione, dextrose) and further reduced in Navstel, an irrigating solution containing a viscosity-modifying agent, hydroxypropyl methylcellulose. Hydroxyl radicals produced in settings representative of those used in phacoemulsification cataract surgery were quantitated using the deoxyribose method. Hydroxyl radical production was dependent on the level of ultrasound power applied and the irrigating solution used. Oxidative stress on the eye during phacoemulsification may be minimized by using irrigating solutions that contain organic molecules, including the viscosity-modifying agent hydroxypropyl methylcellulose, that can compete for reaction with hydroxyl radicals.

Free radicals in biology. Volume II

International Nuclear Information System (INIS)

Pryor, W.A.

1976-01-01

This volume continues the treatment of topics in free radical biology and free radical pathology from Volume I. In the first chapter, pyridinyl radicals, radicals which are models for those derived from NAD, are discussed. Pyridinyl radicals can be synthesized and isolated and directly studied in a number of chemical systems. The next chapter treats the role of glutathione in the cell. It is becoming even more apparent that this vital thiol controls a large number of important cellular functions. The GSH/GSSG balance has recently been implicated as a control for cellular development; this balance also may be important in relaying the effects of oxidants from one site to another in the body. The next chapter outlines the reactions of singlet oxygen; some of these involve free radicals and some do not. This reactive intermediate appears to be important both in photochemical smog and in cellular chemistry where singlet oxygen is produced by nonphotochemical processes. The production of free radicals from dry tissues, a controversial area with conflicting claims is reviewed. The next chapter outlines the current status of the studies of photochemical smog. The next two chapters treat specific reactive materials which are present in smog. The first discusses the chemistry of nitrogen oxides and ozone. The second chapter treats the chemistry of the peroxyacyl nitrites. These compounds, although present in only small concentration, are among the most toxic components of smog. The last two chapters treat radiation damage to proteins and radiation protection and radical reactions produced by radiation in nucleic acids

Estudio del uso de robots industriales como asistentes en operaciones de laparoscopia

Directory of Open Access Journals (Sweden)

Bernardo Efraín Garcés

2009-01-01

Full Text Available Este artículo presenta un estudio sobre el uso de los robots industriales como asistentes en operaciones de laparoscopia. Se presenta un resumen sobre la laparoscopia como método quirúrgico así como de esta intervención asistida por robots. Se aborda de manera particular el problema del paso por el orificio abdominal (trocar por donde se introducen los instrumentos quirúrgicos. Este problema es resuelto a través de un algoritmo de optimización que entrega las trayectorias que deben seguir las articulaciones del codo y la muñeca de un robot antropomórfico. Se estudian dos robots industriales (Puma de Unimation y PA10 de Mitsubishi y se evalúan en simulación sus respectivos desempeños como posibles asistentes en operaciones de este tipo.

HPLC-ESR techniques for detection of complex trapped radicals

International Nuclear Information System (INIS)

Tu Tiecheng; Dong Jirong; Lin Nianyun; Xie Leidong; Liu Rengzhong

1992-01-01

High performance liquid chromatography (HPLC) and ESR combined examination of radical species is an advanced techniques for separation and identification of complex radical species. At SRCL, Waters 990 HPLC has been used to separate the complex trapped radicals and Varian E-112 ESR spectrometer to record the spectra of single trapped radicals after HPLC separation. The advantages of the combined techniques are described as bellow: HPLC is used to separate the long-lived complex trapped radicals derived from reaction of short-lived radicals with spin trap. ESR spectra from single trapped radicals, obtained following HPLC separation of complex trapped radicals, are recorded one by one and well resolved. The structures of short-lived radicals can be inferred from the ESR spectra of the long-lived trapped radicals

Scavenging of free-radical metabolites of aniline xenobiotics and drugs by amino acid derivatives: toxicological implications of radical-transfer reactions.

Science.gov (United States)

Michail, Karim; Baghdasarian, Argishti; Narwaley, Malyaj; Aljuhani, Naif; Siraki, Arno G

2013-12-16

We investigated a novel scavenging mechanism of arylamine free radicals by poly- and monoaminocarboxylates. Free radicals of arylamine xenobiotics and drugs did not react with oxygen in peroxidase-catalyzed reactions; however, they showed marked oxygen uptake in the presence of an aminocarboxylate. These free-radical intermediates were identified using the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and electron paramagnetic resonance (EPR) spectrometry. Diethylenetriaminepentaacetic acid (DTPA), a polyaminocarboxylate, caused a concentration-dependent attenuation of N-centered radicals produced by the peroxidative metabolism of arylamines with the subsequent formation of secondary aliphatic carbon-centered radicals stemming from the cosubstrate molecule. Analogously, N,N-dimethylglycine (DMG) and N-methyliminodiacetate (MIDA), but not iminodiacetic acid (IDA), demonstrated a similar scavenging effect of arylamine-derived free radicals in a horseradish peroxidase/H2O2 system. Using human promyelocytic leukemia (HL-60) cell lysate as a model of human neutrophils, DTPA, MIDA, and DMG readily reduced anilinium cation radicals derived from the arylamines and gave rise to the corresponding carbon radicals. The rate of peroxidase-triggered polymerization of aniline was studied as a measure of nitrogen-radical scavenging. Although, IDA had no effect on the rate of aniline polymerization, this was almost nullified in the presence of DTPA and MIDA at half of the molar concentration of the aniline substrate, whereas a 20 molar excess of DMPO caused only a partial inhibition. Furthermore, the yield of formaldehyde, a specific reaction endproduct of the oxidation of aminocarboxylates by aniline free-radical metabolites, was quantitatively determined. Azobenzene, a specific reaction product of peroxidase-catalyzed free-radical dimerization of aniline, was fully abrogated in the presence of DTPA, as confirmed by GC/MS. Under aerobic conditions, a radical-transfer reaction

Reactions of carbonate radical with cobalt(II) aminopolycarboxylates

International Nuclear Information System (INIS)

Mandal, P.C.; Bardhan, D.K.; Bhattacharyya, S.N.

1992-01-01

Reactions of carbonate (CO 3 - radical) and bicarbonate (HCO 3 radical) radicals generated by photolysis of a carbonate or bicarbonate solution at pH 11.2 and 8.5, respectively, with Co(II) complexes of iminodiacetic acid (IDA) and ethylenediaminetetraacetic acid (EDTA) have been studied. The rate constants for the reactions were in the order of 10 6 -10 7 dm 3 mol -1 s -1 . From the time-resolved spectroscopy of the products formed after reaction of CO 3 - radical or HCO 3 radical, it is observed that CO 3 - radical or HCO 3 radical oxidize the metal center to its higher oxidation state. (author) 26 refs.; 2 figs.; 1 tab

Self-Terminating, Oxidative Radical Cyclizations

Directory of Open Access Journals (Sweden)

Uta Wille

2004-05-01

Full Text Available The recently discovered novel concept of self-terminating, oxidative radical cyclizations, through which alkynes can be converted into carbonyl compounds under very mild reaction conditions using O-centered inorganic and organic radicals as oxidants, is described

El compromiso de Eneas. Virtud y democracia radical tras la dialéctica de la Ilustración

Directory of Open Access Journals (Sweden)

Hernández Castro, David

2009-12-01

Full Text Available The aporia resulting from Horkheimer and Adorno’s critique of the Dialectic of Enlightenment has been raised after the hermeneutic turn of the tradition started by Nietzsche and Heidegger. Essentially it proposes a new Western philosophy beginning, starting from the ontological duality established by the presocratics and maintained by Aristotle against the monological reason of Plato’s teachings. Starting from a new point of view on the Nicomachean and Eudemian ethics, the author puts forward a critique of modern views on Aristotle’s virtue theory, including MacIntyre, in order to propose a new approach to connect the practice of virtue to radical democracy.

La aporía de la dialéctica de la Ilustración ha sido replanteada después de Horkheimer y Adorno por el giro hermenéutico de la tradición que nace con Nietzsche y Heidegger, y que básicamente propone un nuevo comienzo de la filosofía occidental volviendo a la raíz de la dualidad ontológica establecida por los presocráticos y sostenida por Aristóteles frente a la razón monológica de la Academia de Platón. A partir de una nueva interpretación de las éticas Eudemia y Nicomaquea, el autor afrontará una crítica de las visiones modernas de la teoría aristotélica de la virtud, incluida la de MacIntyre, para exponer un nuevo enfoque que vincula la práctica de la virtud con la democracia radical.

An exploratory study regarding the hypothetical human embryo donation in Peru

OpenAIRE

Álvarez Díaz, Jorge Alberto

2013-01-01

Objetivo: Explorar opiniones de pacientes que han acudido a técnicas de reproducción asistida (TRA) complejas, respecto a la donación de gametos y embriones, así como las razones para hacerlo o no. Diseño: Estudio transversal de bioética descriptiva, con metodología cualitativa etnográfica, mediante entrevista semiestructurada, aplicando análisis del discurso al texto resultante. Lugar: Clínica privada, en Lima, Perú. Participantes: Veinte mujeres y 12 hombres, quienes habían acudido por lo m...

Relay-assited transmission and radio resource management for wireless networks

OpenAIRE

Agustín de Dios, Adrián

2008-01-01

La transmisión asistida por relay o transmisión cooperativa es una nueva técnica de diversidad espacial donde aparece un elemento nuevo (un relay o un usuario cooperativo) en la tradicional transmisión punto a punto (fuente a destino). Ahora en la comunicación intervienen tres enlaces: fuente-relay, relay-destino y fuente-destino. El relay, además de asistir a la fuente en la transmisión de un mensaje, permite combatir las degradaciones que puede sufrir el canal como el shadowing y el pathlos...

Integración de inteligencia en la MIB del Modelo OSI para la gestión de redes de telecomunicaciones

OpenAIRE

León de Mora, Carlos; López, Alejandro; Martín Montes, Antonio

2012-01-01

La Gestión de red se define como el conjunto de actividades dedicadas al control y vigilancia de los recursos existentes en las redes de telecomunicaciones. En los complejos sistemas actuales, es necesario realizar una gestión de la red asistida por un software avanzado. La Inteligencia Artificial se incorpora a la gestión de las redes, con el fin de facilitar labores de administración y control de toda la información que proviene de los recursos gestionados, dando origen a la Ges...

Colocación de implantes en zonas atróficas. Técnica con osteótomos : Reporte de caso clínico

OpenAIRE

Tomaghelli, Emanuel Ricardo

2016-01-01

La atrofia vestíbulo-palatina sufrida en el maxilar superior es uno de los desafios estéticos más importantes en cuanto a la planificación de una restauración implanto asistida. Los colapsos vestibulares dificultan no solo la correcta colocación de implantes, estética gingival y arquitectura de las restauraciones protéticas. La técnica quirúrgica, cuando la pérdida ósea es leve a moderada, muchas veces puede ser solucionada utilizando instrumentos de expansión creados por Summers, 1994 llamad...

Oxidation of aromatic amines and diamines by OH radicals. Formation and ionization constants of amine cation radicals in water

International Nuclear Information System (INIS)

Hayon, E.; Rao, P.S.

1975-01-01

The one-electron oxidation by hydroxyl radicals of aromatic amines and diamines in water was studied using the fast-reaction technique of pulse radiolysis and kinetic absorption spectrophotometry. The following compounds were examined: N,N,N 1 ,N 1 - tetramethyl-p-phenylenediamine (TMPD), p-phenylenediamine (PD), N,N-dimethyl-p-phenylenediamene (DMPD), N,N,N 1 ,N 1 -tetramethylbenzidine (TMB), and diphenylamine (DPA). The main initial reaction of the OH radicals is suggested to be an addition to these compounds to give absorption spectra which absorb strongly in the visible and uv regions. These OH radical adducts decay by first-order kinetics and have lifetimes of approximately 5-50 μsec, dependent on the pH, buffer concentration, and the nature of the aromatic amines and diamines. They decay to give species with somewhat similar absorption spectra and extinction coefficients, which are very long lived in the absence of oxygen. The latter species are assigned to the cation radicals TMPD. + , PD. + , DMPD. + , TMB. + , and DPA. + . The OH radical adducts and the cation radicals have acid-base properties. The pK/sub a/ values of the cation radicals TMPDH. 2+ , PDH. 2+ , DMPDH. 2+ , TMBH. 2+ , and DPAH. 2+ were found to be 5.3, 5.9, 6.1, 5.1, and 4.2, respectively. The results indicate that these aromatic amines and diamines can be oxidized by free radicals to yield the corresponding cation radicals. (U.S.)

La derecha radical española y el pensamiento antiliberal francés en el primer tercio del siglo XX. De charles Maurras a Georges Valois

Directory of Open Access Journals (Sweden)

Miguel Ángel PERFECTO GARCÍA

2013-05-01

Full Text Available El objeto de este ensayo sobre la derecha radical española es analizar la vía emprendida por el conservadurismo español desde su adhesión a un liberalismo oligárquico, característico de comienzos del siglo XX, a la formación de una derecha antiliberal que culmina en el fascismo durante la segunda república. En este camino hacia posiciones antidemocráticas, corporativas y autoritarias jugará un papel fundamental la recepción del pensamiento antiliberal francés desde el neotradicionalismo de acción Francesa hasta los movimientos fascistas impulsados por Georges Valois y continuados por alguno de sus discípulos en años posteriores. La relación entre ese pensamiento antiliberal de raíz francesa y la evolución fascistizante de la derecha española será el núcleo central de este trabajo. El artículo se estructura en tres grandes partes: en la primera estudiamos los orígenes del pensamiento antiliberal europeo a partir de dos aspectos fundamentales: 1. la crisis de la conciencia europea a finales del siglo XIX que se tradujo en la aparición de un conjunto de elementos ideológicos antiliberales, nacionalistas y corporativos entre los grupos conservadores de Europa, caldo de cultivo de un pensamiento de derecha radical que culminaría con los fascismos. 2. la Primera Guerra mundial y sus consecuencias que engendraron un mundo nuevo polarizado alrededor del bolchevismo y el fascismo. El pensamiento antiliberal, nacionalista, antidemocrático y corporativo se extiende por toda Europa e impregna de diversas maneras a los grupos conservadores europeos empujándoles a posiciones cada vez más autoritarias y dictatoriales, proceso que algunos historiadores han denominado la «fascistización» de la derecha europea. En segundo lugar, analizamos la formación de la derecha radical española desde sus inicios a comienzos del siglo xx hasta la dictadura de miguel Primo de rivera haciendo hincapié en la contribución del pensamiento

Near-Infrared Free-Radical and Free-Radical-Promoted Cationic Photopolymerizations by In-Source Lighting Using Upconverting Glass.

Science.gov (United States)

Kocaarslan, Azra; Tabanli, Sevcan; Eryurek, Gonul; Yagci, Yusuf

2017-11-13

A method is presented for the initiation of free-radical and free-radical-promoted cationic photopolymerizations by in-source lighting in the near-infrared (NIR) region using upconverting glass (UCG). This approach utilizes laser irradiation of UCG at 975 nm in the presence of fluorescein (FL) and pentamethyldiethylene triamine (PMDETA). FL excited by light emitted from the UCG undergoes electron-transfer reactions with PMDETA to form free radicals capable of initiating polymerization of methyl methacrylate. To execute the corresponding free-radical-promoted cationic polymerization of cyclohexene oxide, isobutyl vinyl ether, and N-vinyl carbazole, it was necessary to use FL, dimethyl aniline (DMA), and diphenyliodonium hexafluorophosphate as sensitizer, coinitiator, and oxidant, respectively. Iodonium ions promptly oxidize DMA radicals formed to the corresponding cations. Thus, cationic polymerization with efficiency comparable to the conventional irradiation source was achieved. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

OH radical induced depolymerization of poly(methacrylic acid)

Science.gov (United States)

Ulanski, Piotr; Bothe, Eberhard; von Sonntag, Clemens

1999-05-01

Hydroxyl radicals (generated pulse radiolytically in dilute N 2O-saturated aqueous solutions) react with poly(methacrylic acid) producing two kinds of radicals. The primary radical is converted into a secondary one by H-abstraction ( k=3.5 × 10 2 s -1) as monitored by changes in the UV spectrum. Subsequently, the secondary radicals undergo chain scission ( k=1.8 s -1 at pH 7-9). This process has been followed both by spectrophotometry as well as by conductometry. In competition with the bimolecular decay of the radicals the ensuing end-chain radicals undergo efficient depolymerization resulting in the release of monomer. Since the lifetime of the radicals is much longer at high pH, where the polymer attains a rod-like conformation, depolymerization is most efficient in basic solution.

Electron spin resonance study of radicals in irradiated polyethylene

International Nuclear Information System (INIS)

Fujimura, Takashi

1979-02-01

In order to elucidate radiation effect in polyethylene, the nature and behavior of radicals produced in polyethylene and the model compound of polyethylene irradiated at 77 0 K were studied by using electron spin resonance. The structure of radical pairs, which are composed of two radicals produced very closely each other, was investigated in drawn polyethylene and the single crystal of n-eicosane. The radical pairs of intrachain type and interchain type were found in polyethylene and n-eicosane respectively. It was suggested that these two types of radical pairs are the precursors of double bonds and crosslinks respectively. The thermal decay reactions of radicals themselves produced in irradiated polyethylene were investigated. It was made clear that the short range distances between two radicals play an important role in the decay reaction of alkyl radicals at low temperatures. The trapping regions of radicals were studied and it was clarified that allyl radicals, which are produced by the reaction of alkyl radicals with double bonds, are trapped both in the crystalline and non-crystalline regions. (author)

Redox properties of free radicals

International Nuclear Information System (INIS)

Neta, P.

1981-01-01

Results of electron transfer reactions observed and monitored by pulse radiolysis are reported. This technique allows determination of the first one-electron reduction or oxidation of a compound rather than the overall two-electron transfer usually reported. Pulse radiolysis allows the determination of absolute rate constants for reactions of free radicals and helps elucidate the mechanisms involved. Studies using this technique to study radicals derived from quinones, nitro compounds, pyridines, phenols, and anilines are reported. Radicals of biochemical interest arising from riboflavin, ascorbic acid, vitamin K 3 , vitamin E, MAD + , porphyrins, etc. have also been studied

Hot wire radicals and reactions

International Nuclear Information System (INIS)

Zheng Wengang; Gallagher, Alan

2006-01-01

Threshold ionization mass spectroscopy is used to measure radical (and stable gas) densities at the substrate of a tungsten hot wire (HW) reactor. We report measurements of the silane reaction probability on the HW and the probability of Si and H release from the HW. We describe a model for the atomic H release, based on the H 2 dissociation model. We note major variations in silicon-release, with dependence on prior silane exposure. Measured radical densities versus silane pressure yield silicon-silane and H-silane reaction rate coefficients, and the dominant radical fluxes to the substrate

Synthesis and Characterization of Ethylenedithio-MPTTF-PTM Radical Dyad as a Potential Neutral Radical Conductor

DEFF Research Database (Denmark)

Souto, Manuel; Bendixen, Dan; Jensen, Morten

2016-01-01

During the last years there has been a high interest in the development of new purely-organic single-component conductors. Very recently, we have reported a new neutral radical conductor based on the perchlorotriphenylmethyl (PTM) radical moiety linked to a monopyrrolo-tetrathiafulvalene (MPTTF...

Free radicals trapped in polyethylene matrix

International Nuclear Information System (INIS)

Shimada, S.; Maeda, M.; Hori, Y.; Kashiwabara, H.

1977-01-01

Two types of alkyl radicals were found to be trapped in irradiated crystals grown from polyethylene solution. One of them corresponds to the broad sextet pattern of the e.s.r. spectrum and the other corresponds to the sharp sextet pattern. The free radicals attributed to the broad sextet began to disappear at a lower temperature than the temperature at which the free radicals attributed to the sharp sextet disappeared. When butadiene molecules were brought into contact with the specimen, the decay of the free radicals corresponding to the broad sextet was accelerated. When the specimen was subjected to fuming nitric acid treatment, no broad sextet was observed. The mat of the crystals was aligned so that the c-axes of its crystallites were perpendicular to its surface. The broad sextet showed no anisotropy when the angle between the direction of applied magnetic field and that of the c-axis of the crystallite was varied. On the other hand, the sharp component of the spectrum showed apparent anisotropy. It can be concluded that the broad component comes from the free radicals trapped in the lamellar surface and the sharp component is attributed to the free radicals trapped in the inner part of the crystallite. (author)

The role of melanin as protector against free radicals in skin and its role as free radical indicator in hair

Science.gov (United States)

Herrling, Thomas; Jung, Katinka; Fuchs, Jürgen

2008-05-01

Throughout the body, melanin is a homogenous biological polymer containing a population of intrinsic, semiquinone-like radicals. Additional extrinsic free radicals are reversibly photo-generated by UV and visible light. Melanin photochemistry, particularly the formation and decay of extrinsic radicals, has been the subject of numerous electron spin resonance (ESR) spectroscopy studies. Several melanin monomers exist, and the predominant monomer in a melanin polymer depends on its location within an organism. In skin and hair, melanin differs in content of eumelanin or pheomelanin. Its bioradical character and its susceptibility to UV irradiation makes melanin an excellent indicator for UV-related processes in both skin and hair. The existence of melanin in skin is strongly correlated with the prevention against free radicals/ROS generated by UV radiation. Especially in the skin melanin (mainly eumelanin) ensures the only natural UV protection by eliminating the generated free radicals/ROS. Melanin in hair can be used as a free radical detector for evaluating the efficacy of hair care products. The aim of this study was to investigate the suitability of melanin as protector of skin against UV generated free radicals and as free radical indicator in hair.

Free radicals generated by radiolysis of aqueous solutions

International Nuclear Information System (INIS)

Schwarz, H.A.

1981-01-01

The free radicals produced in the radiolysis of aqueous solutions span the range of redox potentials from -2.9 to +2.65 volts. The identity and nature of these radicals were discussed. Most of the discussion was results obtained with low LET radiation sources ( 60 Co gamma radiation or electron accelerators). Water radiolysis provides the synthesis of many radicals and radical ions in aqueous solution. The primary radicals, e/sub aq/ - H, OH, are well characterized. The radical population can be made to be 90% pure OH (or O - ) if N 2 O solutions are irradiated, the remaining 10% being H atoms. 55% of the radicals can be converted to H atoms in acid solution or in neutral phosphate solutions(e/sub aq/ - reacts with H 2 PO 4- to produce H). The remaining 45% (OH radicals) are difficult to convert to H by reaction with H 2 , due to the slow rate of the reaction. About 100 atmospheres of H 2 are required to do the conversion in less than 10 - 6 sec. 3 figures, 3 tables. (DP)

Radical carbonylations using a continuous microflow system

Directory of Open Access Journals (Sweden)

Takahide Fukuyama

2009-07-01

Full Text Available Radical-based carbonylation reactions of alkyl halides were conducted in a microflow reactor under pressurized carbon monoxide gas. Good to excellent yields of carbonylated products were obtained via radical formylation, carbonylative cyclization and three-component coupling reactions, using tributyltin hydride or TTMSS as a radical mediator.

Radical-Mediated Enzymatic Polymerizations

Science.gov (United States)

Zavada, Scott R.; Battsengel, Tsatsral; Scott, Timothy F.

2016-01-01

Polymerization reactions are commonly effected by exposing monomer formulations to some initiation stimulus such as elevated temperature, light, or a chemical reactant. Increasingly, these polymerization reactions are mediated by enzymes―catalytic proteins―owing to their reaction efficiency under mild conditions as well as their environmental friendliness. The utilization of enzymes, particularly oxidases and peroxidases, for generating radicals via reduction-oxidation mechanisms is especially common for initiating radical-mediated polymerization reactions, including vinyl chain-growth polymerization, atom transfer radical polymerization, thiol–ene step-growth polymerization, and polymerization via oxidative coupling. While enzyme-mediated polymerization is useful for the production of materials intended for subsequent use, it is especially well-suited for in situ polymerizations, where the polymer is formed in the place where it will be utilized. Such polymerizations are especially useful for biomedical adhesives and for sensing applications. PMID:26848652

Allylthioketone Mediated Free Radical Polymerization of Methacrylates

Directory of Open Access Journals (Sweden)

Feng Zhong

2017-11-01

Full Text Available By combination of high trapping free radical efficiency of the thioketone and resonance of the allylic radical, a new type of mediating agent, 1,3,3-triphenylprop-2-ene-1-thione (TPPT has been successfully synthesized, and then is used to study controlled free radical polymerization of methacrylates. Very stable TPPT radicals at the end of poly(methyl methacrylate (PMMA are detected in the polymerization of MMA using TPPT and AIBN as the control agent and initiator. The MALDI-TOF MS spectra are used to identify terminal groups of the resultant poly(glycidyl methacrylate (PGMA, and major component of the obtained polymer has the structure, (CH32(CNC-PGMA-C7H9O3. Chain extension reaction tests ascertain formation of the dead polymers during the polymer storage and purification process of the polymers. Owing to very slow fragmentation reaction of the TPPT-terminated polymethacrylate radical and addition reaction of this radical with a primary radical, the growing chain radicals are difficult to be regenerated, leading to an unobvious change of the molecular weight with monomer conversion. The molecular weights of polymers can be controlled by the ratios of monomer/initiator and TPPT/initiator. However, the first order kinetics of the polymerization and the polymers with narrow polydispersity are obtained, and these phenomena are discussed. This study provides useful information on how to design a better controlling agent.

Fluorescence lifetime measurement of radical ions

International Nuclear Information System (INIS)

Ichinose, Nobuyuki; Kinugasa, Jun-ichiro; Hagiri, Masahide; Nakayama, Toshihiro; Murakami, Hiroshi; Kishimoto, Maki; Daido, Hiroyuki

2004-01-01

One-photonic excitation of a charge transfer complex of hexamethoxybenzene (HMB) and nitrosonium tetrafluoroborate (NO + BF 4 - ) in acetonitrile afforded fluorescences emission from excited radical cation of HMB (HMB + *). Lifetime of the excited radical ion species was measured to be 7 ps by the pump-probe transient absorption technique. The lifetime was much shorter than that of free radical ion (63 ps), indicating the presence of an interaction between HMB + * and NO in the excited complex. (author)

Generation and propagation of radical reactions on proteins

DEFF Research Database (Denmark)

Hawkins, C L; Davies, Michael Jonathan

2001-01-01

The oxidation of proteins by free radicals is thought to play a major role in many oxidative processes within cells and is implicated in a number of human diseases as well as ageing. This review summarises information on the formation of radicals on peptides and proteins and how radical damage may...... be propagated and transferred within protein structures. The emphasis of this article is primarily on the deleterious actions of radicals generated on proteins, and their mechanisms of action, rather than on enzymatic systems where radicals are deliberately formed as transient intermediates. The final section...

Radical scavenging activity of crude polysaccharides from Camellia sinensis

Directory of Open Access Journals (Sweden)

Yang Fan

2011-01-01

Full Text Available A preparation of crude polysaccharides (TPS was isolated from Camellia sinensis by precipitation and ultrafiltration. TPS1, TPS2, and TPS3 had molecular weights of 240, 21.4, and 2.46 kDa, respectively. The radical scavenging activities of TPS were evaluated by DPPH free radical, hydroxyl radical and superoxide radical scavenging. These results revealed that TPS exhibited strong radical scavenging activity in a concentration-dependent manner. TPS3 with lowest molecular weight showed a higher radical scavenging activity.

Vibronic Spectroscopy of the Phenylcyanomethyl Radical

Science.gov (United States)

Mehta, Deepali N.; Kidwell, Nathanael M.; Zwier, Timothy S.

2011-06-01

Resonance stabilized radicals (RSRs) are thought to be key intermediates in the formation of larger molecules in planetary atmospheres. Given the nitrogen-rich atmosphere of Titan, and the prevalence of nitriles there, it is likely that nitrile and isonitrile RSRs could be especially important in pathways leading to the formation of more complex nitrogen-containing compounds and the aerosols ("tholins") that are ultimately produced. In this talk, the results of a gas phase, jet-cooled vibronic spectroscopy study of the phenylcyanomethyl radical (C_6H_5.{C}HCN), the nitrogen-containing analog of the 1-phenylpropargyl radical, will be presented. A resonant two color photon ionization spectrum over the range 21,350-22,200 Cm-1 (450.0-468.0 nm) has been recorded, and the D_0-D_1 origin band has been tentatively identified at 21,400 Cm-1. Studies identifying the ionization threshold, and characterizing the vibronic structure will also be presented. An analogous study of the phenylisocyanomethyl radical, C_6H_5.{C}HNC, is currently being pursued for comparison with that of phenylcyanomethyl radical.

Introducing Stable Radicals into Molecular Machines.

Science.gov (United States)

Wang, Yuping; Frasconi, Marco; Stoddart, J Fraser

2017-09-27

Ever since their discovery, stable organic radicals have received considerable attention from chemists because of their unique optical, electronic, and magnetic properties. Currently, one of the most appealing challenges for the chemical community is to develop sophisticated artificial molecular machines that can do work by consuming external energy, after the manner of motor proteins. In this context, radical-pairing interactions are important in addressing the challenge: they not only provide supramolecular assistance in the synthesis of molecular machines but also open the door to developing multifunctional systems relying on the various properties of the radical species. In this Outlook, by taking the radical cationic state of 1,1'-dialkyl-4,4'-bipyridinium (BIPY •+ ) as an example, we highlight our research on the art and science of introducing radical-pairing interactions into functional systems, from prototypical molecular switches to complex molecular machines, followed by a discussion of the (i) limitations of the current systems and (ii) future research directions for designing BIPY •+ -based molecular machines with useful functions.

Some reactions of oxidizing radicals with enzymes in aqueous solution

International Nuclear Information System (INIS)

Cundall, R.B.; Bisby, R.H.; Hoe, S.T.; Sims, H.E.; Anderson, R.F.

1979-01-01

A range of oxidizing radicals including some inorganic radical anions and the superoxide radical, can be generated by radiolysis of aqueous solutions. These radicals are more selective in their reactions with amino acids than the hydroxyl radical. Factors controlling the apparent reactivity of radical anions with proteins, such as free radical equilibria and ion-binding, are described. The superoxide radical inactivates papain by reaction with the cysteine residue. This reaction has been studied in solutions subjected to radiations of varying linear energy transfer. (Auth.)

Long-lived gas-phase radicals from combustion

Energy Technology Data Exchange (ETDEWEB)

Kaneko, Takashi; Furusawa, Koji; Amano, Toshiji; Okubo, Yoichi; Tsuchiya, Jun' ichi; Yoshizawa, Fujiroku; Akutsu, Yoshiaki; Tamura, Masamitsu; Yoshida, Tadao (Univ. of Tokyo (Japan))

1989-04-20

On indoor air pollution or fire, it is feared that the gas-phase radicals from the combustion of inflammables or fuel seriously exert an influence on the organisms as harmful matter. The gas-phase radicals were studied using the electron spin resonance (ESR) spin-trapping technique. For the spin trap solution, 0.1 mol solution of {alpha}-phenyl-N-t-butylnitron in benzene was used. As a result, apparently long-lived and highly reactive oxygen-centered radicals were detected in the smoke from polyethylene, polypropylene, polystyrene, polymethylmethacrylate, cellulose, kerosene, benzene, acetone, methanol and butylalcohol. It is suggested that the production mechanism for the radicals should be different from olefin-NOx-air system reaction, which is considered for the radicals from cigarette smoke. 11 refs., 6 figs., 2 tabs.

[Research progress on free radicals in human body].

Science.gov (United States)

Wang, Q B; Xu, F P; Wei, C X; Peng, J; Dong, X D

2016-08-10

Free radicals are the intermediates of metabolism, widely exist in the human bodies. Under normal circumstances, the free radicals play an important role in the metabolic process on human body, cell signal pathway, gene regulation, induction of cell proliferation and apoptosis, so as to maintain the normal growth and development of human body and to inhibit the growth of bacteria, virus and cancer. However, when organic lesion occurs affected by external factors or when equilibrium of the free radicals is tipped in the human body, the free radicals will respond integratedly with lipids, protein or nucleic acid which may jeopardize the health of human bodies. This paper summarizes the research progress of the free radicals conducted in recent years, in relations to the perspective of the types, origins, test methods of the free radicals and their relationship with human's health. In addition, the possible mechanisms of environmental pollutants (such as polycyclic aromatic hydrocarbons) mediating oxidative stress and free radicals scavenging in the body were also summarized.

Deciphering free-radical code of radiation effects

International Nuclear Information System (INIS)

Volovyk, S.; Bazyka, D.; Loganovsky, K.; Bebeshko, V.

2007-01-01

Complete text of publication follows. Objective: Ionizing radiation is fundamental environmental factor for life origin and evolution. Free radicals, primordial 'sea' for life conceiving and existence, induced by cosmic and terrestrial background radiation, are evolutionally archetypal, ubiquitous, and omnipotent in physiological- pathophysiological dichotomy. Classical free-radical paradigm in radiation biology and medicine, focused in essence on oxidative damage, needs new conceptualization and generalization. Methods: Suggested novel insights into free radicals dual immanent nature and functions in organism systems are based on original concepts of radicals dynamic charge transfer (CT) - redox ambivalence (interactional nucleo-, electro-, and ambiphilicity spectrum); pertinent chemical reactivity and selectivity delocalization model; physiological functional ambivalence and complementarity, and dynamic free-radical homeostasis. Results: Subtle perturbations in radicals CT spatiotemporal homeodynamics, in responsive signaling / controlling networks, concomitant alterations in genes expression, transcription, and apoptosis, redox control of mitochondrial ET chain, telomere/telomerase balance, DNA CT, circadian clock, hemispheric biochemical dominance/accentuation, including alteration of nitric oxide-superoxide complementarity, membranes permeability, neurotransmission pattern, synaptic circuitry, etc under radiation exposure have more fundamental impact on organism systems (especially CNS and CVS) deterioration than simple radicals inflicted oxidative (nitrosative) damage of cellular constituents. Conclusions: This novel conceptualization of free-radical paradigm constitutes new dimension in deciphering molecular mechanisms of radiation effects on subtle borderline norm-pathology and continuity-discontinuity dichotomy in organisms systems disorders - CT(redox)omics, which involves investigation of CT, redox, and spin states of free radicals, DNA bases

Radical, reformist and aborted liberalism: origins of national regimes in Central America Liberalismo radical, reformista y frustrado: orígenes de los regímenes nacionales en América central

Directory of Open Access Journals (Sweden)

James MAHONEY

2011-06-01

Full Text Available During the twentieth century, the countries of Central America were characterized by remarkably different political regimes: military-authoritarianism in Guatemala and El Salvador, progressive democracy in Costa Rica and traditional-authoritarianism in Honduras and Nicaragua. This article explains these contrasting regime outcomes by exploring the agrarian and state-building reforms pursued by political leaders during the nineteenth– and early twentieth century liberal reform period. Based on differences in the transformation of state and class structures, three types of liberalism are identified: radical liberalism in Guatemala and El Salvador, reformist liberalism in Costa Rica and aborted liberalism in Honduras and Nicaragua. It is argued that these types of liberalism set the Central American countries on contrasting paths of political development, culminating in diverse regime outcomes.Durante el siglo XX, los países de América Central se caracterizaron por tener regímenes políticos muy diferentes: el autoritarismo militar en Guatemala y El Salvador; la democracia progresista en Costa Rica y el autoritarismo tradicional en Honduras y Nicaragua. Este artículo explica los resultados de estos distintos regímenes mediante la exploración de las reformas agrarias y de la construcción del Estado llevadas a cabo por los líderes políticos durante el siglo XIX y principios del periodo de reformas liberales del siglo XX. Basándose en las diferencias de la transformación del Estado y de las estructuras de clases, se pueden identificar tres tipos de liberalismo: liberalismo radical en Guatemala y El Salvador; liberalismo reformista en Costa Rica y liberalismo frustrado en Honduras y Nicaragua. Se argumenta que estos tipos de liberalismo condujeron a los países de América Central a caminos contrarios al desarrollo político, culminando así en regímenes con resultados diversos.

Zwitterion radicals and anion radicals from electron transfer and solvent condensation with the fingerprint developing agent ninhydrin.

Science.gov (United States)

Schertz, T D; Reiter, R C; Stevenson, C D

2001-11-16

Ninhydrin (the fingerprint developing agent) spontaneously dehydrates in liquid ammonia and in hexamethylphosphoramide (HMPA) to form indantrione, which has a sufficiently large solution electron affinity to extract an electron from the solvent (HMPA) to produce the indantrione anion radical. In liquid NH(3), the presence of trace amounts of amide ion causes the spontaneous formation of an anion radical condensation product, wherein the no. 2 carbon (originally a carbonyl carbon) becomes substituted with -NH(2) and -OH groups. In HMPA, the indantrione anion radical spontaneously forms condensation products with the HMPA to produce a variety of zwitterionic radicals, wherein the no. 2 carbon becomes directly attached to a nitrogen of the HMPA. The mechanisms for the formation of the zwitterionic paramagnetic condensation products are analogous to that observed in the reaction of ninhydrin with amino acids to yield Ruhemann's Purple, the contrast product in fingerprint development. The formation of anion and zwitterionic radical condensation products from ninhydrin and nitrogen-containing solvents may represent an example of a host of analogous polyketone-solvent reactions.

Free radical scavenging injectable hydrogels for regenerative therapy

Energy Technology Data Exchange (ETDEWEB)

Komeri, Remya [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Polymer Science Division, BMT Wing, Thiruvananthapuram 695 012, Kerala State (India); Thankam, Finosh Gnanaprakasam [Dept. of Biomedical Sciences, Creighton University, 2500 California Plaza, Omaha NE68178 (United States); Muthu, Jayabalan, E-mail: mjayabalan52@gmail.com [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Polymer Science Division, BMT Wing, Thiruvananthapuram 695 012, Kerala State (India)

2017-02-01

Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07 kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy. - Graphical abstract: Injectable hydrogel with inherent free radical scavenging property for regenerative tissue engineering application. - Highlights: • Novel injectable hydrogel (PEAX-P) is prepared using D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer

Free radical scavenging injectable hydrogels for regenerative therapy

International Nuclear Information System (INIS)

Komeri, Remya; Thankam, Finosh Gnanaprakasam; Muthu, Jayabalan

2017-01-01

Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07 kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy. - Graphical abstract: Injectable hydrogel with inherent free radical scavenging property for regenerative tissue engineering application. - Highlights: • Novel injectable hydrogel (PEAX-P) is prepared using D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer

Radical Transversal Lightlike Submanifolds of Indefinite Para-Sasakian Manifolds

OpenAIRE

Shukla S.S.; Yadav Akhilesh

2014-01-01

In this paper, we study radical transversal lightlike submanifolds and screen slant radical transversal lightlike submanifolds of indefinite para-Sasakian manifolds giving some non-trivial examples of these submanifolds. Integrability conditions of distributions D and RadTM on radical transversal lightlike submanifolds and screen slant radical transversal lightlike submanifolds of indefinite para-Sasakian manifolds, have been obtained. We also study totally contact umbilical radical transvers...

Structure and reactivity of the N-acetyl-cysteine radical cation and anion: does radical migration occur?

NARCIS (Netherlands)

Osburn, S.; Berden, G.; Oomens, J.; O'Hair, R.A.J.; Ryzhov, V.

2011-01-01

The structure and reactivity of the N-acetyl-cysteine radical cation and anion were studied using ion-molecule reactions, infrared multi-photon dissociation (IRMPD) spectroscopy, and density functional theory (DFT) calculations. The radical cation was generated by first nitrosylating the thiol of

Structure and Reactivity of the N-Acetyl-Cysteine Radical Cation and Anion: Does Radical Migration Occur?

NARCIS (Netherlands)

Osburn, S.; G. Berden,; Oomens, J.; O' Hair, R. A. J.; Ryzhov, V.

2011-01-01

The structure and reactivity of the N-acetyl-cysteine radical cation and anion were studied using ion-molecule reactions, infrared multi-photon dissociation (IRMPD) spectroscopy, and density functional theory (DFT) calculations. The radical cation was generated by first nitrosylating the thiol of

Cation radicals of xanthophylls.

Science.gov (United States)

Galinato, Mary Grace I; Niedzwiedzki, Dariusz; Deal, Cailin; Birge, Robert R; Frank, Harry A

2007-10-01

Carotenes and xanthophylls are well known to act as electron donors in redox processes. This ability is thought to be associated with the inhibition of oxidative reactions in reaction centers and light-harvesting pigment-protein complexes of photosystem II (PSII). In this work, cation radicals of neoxanthin, violaxanthin, lutein, zeaxanthin, beta-cryptoxanthin, beta-carotene, and lycopene were generated in solution using ferric chloride as an oxidant and then studied by absorption spectroscopy. The investigation provides a view toward understanding the molecular features that determine the spectral properties of cation radicals of carotenoids. The absorption spectral data reveal a shift to longer wavelength with increasing pi-chain length. However, zeaxanthin and beta-cryptoxanthin exhibit cation radical spectra blue-shifted compared to that of beta-carotene, despite all of these molecules having 11 conjugated carbon-carbon double bonds. CIS molecular orbital theory quantum computations interpret this effect as due to the hydroxyl groups in the terminal rings selectively stabilizing the highest occupied molecular orbitals of preferentially populated s-trans-isomers. The data are expected to be useful in the analysis of spectral results from PSII pigment-protein complexes seeking to understand the role of carotene and xanthophyll cation radicals in regulating excited state energy flow, in protecting PSII reaction centers against photoinhibition, and in dissipating excess light energy absorbed by photosynthetic organisms but not used for photosynthesis.

Violent Radicalization in Europe

DEFF Research Database (Denmark)

Dalgaard-Nielsen, Anja

2010-01-01

When, why, and how do people living in a democracy become radicalized to the point of being willing to use or directly support the use of terrorist violence against fellow citizens? This question has been at the center of academic and public debate over the past years as terrorist attacks...... within this field and to answer the question: From an empirical point of view, what is known and what is not known about radicalization connected to militant Islamism in Europe?...

Application of ABTS radical cation for selective on-line detection of radical scavengers in HPLC eluates

NARCIS (Netherlands)

Koleva, [No Value; Niederlander, HAG; van Beek, TA

2001-01-01

The radical cation 2,2 ' -azinobis-(3 -ethylbenzothiazoline-6-sulfonate), (ABTS(.+)) was utilized in an on-line HPLC method for the detection of radical scavengers in complex matrixes. The HPLC-separated analytes react postcolumn with the preformed ABTS(.+), and the induced bleaching is detected as

Critical appraisal of outcomes following open radical prostatectomy.

Science.gov (United States)

Galvin, David J; Eastham, James A

2009-05-01

Radical prostatectomy has evolved enormously over the last 25 years. Improvements include the use of smaller incisions, reduced blood loss, shorter hospital stays, and surgical refinement to improve the recovery of continence and potency. In addition, new technologies and minimally invasive techniques with the potential to further improve patient outcomes have been introduced. This article focuses on outcomes with open radical prostatectomy and is not meant to compare open radical prostatectomy and minimally invasive approaches. Despite a lack of randomized controlled trials, strong observational cohort studies demonstrate lower rates of positive surgical margins, high 10-year and 15-year biochemical recurrence-free rates, excellent prostate cancer-specific mortality rates, and improved recovery of urinary incontinence and erectile function after open radical prostatectomy. We review publications from the past 24 months regarding oncologic outcome, continence, and erectile function, as well as some earlier manuscripts that emphasize key aspects of open radical prostatectomy. Today open radical prostatectomy is a less-invasive procedure with low morbidity providing excellent control of clinically localized prostate cancer. Although open radical prostatectomy now accounts for a minority of radical prostatectomies in the United States, the concepts that have improved oncologic and quality-of-life outcomes are equally applicable to minimally invasive procedures.

NOx removal characteristics of corona radical shower with ammonia and methylamine radical injections

Energy Technology Data Exchange (ETDEWEB)

Urashima, K.; Ara, M.; Chang, J.S. [McMaster Univ., Hamilton, ON (Canada). Dept. of Engineering Physics; Uchida, Y. [Aichi Inst. of Technology, (Japan). Dept. of Engineering

2010-07-01

Air pollutants such as nitrogen oxides (NOx) and sulfur oxides (SOx) are the major cause of acid rain. There are different types of NOx and SOx conversion techniques such as wet scrubber, selective catalytic reactor, sorbent injection, and low NOx burner. Non-thermal plasma techniques have also been utilized in commercial plants, but the energy efficiency of the non-thermal plasma reactors have not yet been optimized. The direct plasma treatments of flue gases including, the electron beam, barrier discharge and pulsed corona reactors, may lose input energy to activate unwanted components of flue gases such as carbon dioxide (CO{sub 2}) and nitrogen (N{sub 2}). The corona discharge ammonia radical shower system has demonstrated significant NOx removal with higher energy efficiency for large bench scale and pilot plant tests for combustion exhausts. An experiment has also demonstrated that methane can replace ammonia as an injection gas with less NOx removal efficiency. This paper presented an experimental investigation that compared methylamine radical injection with traditional ammonia and methane radical injections. The paper discussed the bench scale test facilities and corona radical shower plasma reactor. It was concluded that the processes to form ammonium nitrate could be observed from trace white solid particles deposited on the reactor wall as observed by scanning electron microscopy pictures. 10 refs., 5 figs., 2 appendices.

Radical Sustainable Innovation of office buildings

DEFF Research Database (Denmark)

Koch, Christian; Berker, Thomas; Koch-Ørvad, Nina

2017-01-01

by high degrees of newness in the entire life cycle. RSI should offer significant enhancements of known benefits, entirely new benefits, or substantial cost reductions, leading to the transformation of existing markets, the creation of sustainable growth, and global sustainability. Thus, if buildings were....../could be radically new. How to evaluate radicality is a major challenge. It is tentatively proposed, to use standards for sustainable office buildings. Standards are developed to accelerate the sustainable development but has to some extent come to constrain possibilities of radical innovation. As the criteria...... of newness is incorporated in standards, going beyond them, could be viewed as radical. Empirically a selection of international cases of office buildings with very high scores of BREEAM, LEED and DGNB are examined. Six selected cases were analysed more in detail, one of them, Geelens...

User involvement competence for radical innovation

DEFF Research Database (Denmark)

Lettl, Christopher

2007-01-01

-assisted navigation systems. The case study analysis reveals that firms who closely interact with specific users benefit significantly for their radical innovation work. These users have a high motivation toward new solutions, are open to new technologies, possess diverse competencies, and are embedded into a very......One important market related capability for firms which seek to develop radical innovations is the competence to involve the 'right' users at the 'right' time in the 'right' form. While former studies have identified a rather passive role of users in the radical innovation process, this paper...

User involvement competence for radical innovation

DEFF Research Database (Denmark)

Lettl, Christopher

2007-01-01

One important market related capability for firms which seek to develop radical innovations is the competence to involve the 'right' users at the 'right' time in the 'right' form. While former studies have identified a rather passive role of users in the radical innovation process, this paper......-assisted navigation systems. The case study analysis reveals that firms who closely interact with specific users benefit significantly for their radical innovation work. These users have a high motivation toward new solutions, are open to new technologies, possess diverse competencies, and are embedded into a very...

Protonated o-semiquinone radical as a mimetic of the humic acids native radicals: A DFT approach to the molecular structure and EPR properties

Science.gov (United States)

Witwicki, Maciej; Jezierska, Julia

2012-06-01

Organic radicals are known to be an indispensable component of the humic acids (HA) structure. In HA two forms of radicals, stable (native) and short-lived (transient), are identified. Importantly, these radical forms can be easily differentiated by electron paramagnetic resonance (EPR) spectroscopy. This article provides a DFT-based insight into the electronic and molecular structure of the native radicals. The molecular models including an increase of the radical aromaticity and the hydrogen bonding between the radical and other functional groups of HA are taken under investigation. In consequence the interesting pieces of information on the structure of the native radical centers in HA are revealed and discussed, especially in terms of differences between the electronic structure of the native and transient forms.

Intramolecular hydrogen bonding in malonaldehyde and its radical analogues.

Science.gov (United States)

Lin, Chen; Kumar, Manoj; Finney, Brian A; Francisco, Joseph S

2017-09-28

High level Brueckner doubles with triples correction method-based ab initio calculations have been used to investigate the nature of intramolecular hydrogen bonding and intramolecular hydrogen atom transfer in cis-malonaldehyde (MA) and its radical analogues. The radicals considered here are the ones that correspond to the homolytic cleavage of C-H bonds in cis-MA. The results suggest that cis-MA and its radical analogues, cis-MA RS , and cis-MA RA , both exist in planar geometry. The calculated intramolecular O-H⋯O=C bond in cis-MA is shorter than that in the radical analogues. The intramolecular hydrogen bond in cis-MA is stronger than in its radicals by at least 3.0 kcal/mol. The stability of a cis-malonaldehyde radical correlates with the extent of electron spin delocalization; cis-MA RA , in which the radical spin is more delocalized, is the most stable MA radical, whereas cis-MA RS , in which the radical spin is strongly localized, is the least stable radical. The natural bond orbital analysis indicates that the intramolecular hydrogen bonding (O⋯H⋯O) in cis-malonaldehyde radicals is stabilized by the interaction between the lone pair orbitals of donor oxygen and the σ * orbital of acceptor O-H bond (n → σ * OH ). The calculated barriers indicate that the intramolecular proton transfer in cis-MA involves 2.2 kcal/mol lower barrier than that in cis-MA RS .

Efecto secuestrador del D-002 sobre radicales hidroxilo en mucosa gástrica Scavenger effect of D-002 on hydroxyl radicals in the gastric mucosa

Directory of Open Access Journals (Sweden)

Yohani Pérez Guerra

2012-03-01

Full Text Available Introducción: el agente causal de la ulceración gástrica está asociado al desequilibrio entre factores agresivos y defensivos que actúan sobre la mucosa gástrica. El D-002, mezcla de seis alcoholes alifáticos primarios superiores purificada de la cera de abejas, produce efectos gastroprotectores mediados por múltiples mecanismos y reducción de la peroxidación lipídica en la mucosa gástrica. Objetivo: determinar si el D-002 es capaz de capturar el radical hidroxilo añadido in vitro o generado in vivo en ratas con úlcera gástrica inducida por indometacina. Métodos: En la experiencia in vitro el D-002 se añadió a concentraciones entre 0,9 y 1 000 mg/mL. En la experiencia in vivo las ratas se distribuyeron en seis grupos: un control negativo y cinco que recibieron indometacina: un control positivo tratado con el vehículo, tres con D-002 (5, 25, y 100 mg/kg, respectivamente, p.o. y otro con omeprazol (20 mg/kg i.p.. Los tratamientos se administraron una hora (vehículo y D-002 o 30 min (omeprazol, respectivamente, antes de inducir las úlceras. En ambas experiencias se tomaron alícuotas de mucosa gástrica, y se determinó el daño a la 2-desoxirribosa por el radical hidroxilo. Resultados: la administración oral del D-002, no in vitro, protegió a la 2-desoxirribosa del daño oxidativo de modo marcado, significativo y dependiente de la dosis con respecto al control positivo. Conclusiones: los resultados indican que la capacidad del D-002 (25 y 100 mg/kg administrado por vía oral para secuestrar el radical hidroxilo, generado en la mucosa gástrica por la indometacina, pudiera contribuir a sus efectos antioxidantes y gastroprotectores sobre el daño que los antiinflamatorios no esteroideos producen sobre la mucosa gástrica.Introduction: the etiology of the gastric ulceration is associated to the imbalance between aggressive and defensive factors acting upon the gastric mucosa. D-002, a mixture of 6 higher primary alcohols

La vida humana como principio interpretativo radical en la filosofía de Ortega y Gasset

OpenAIRE

Gutiérrez-Pozo,Antonio

2012-01-01

En este artículo presentamos el concepto de vida humana como texto eterno en el pensamiento de Ortega y sus consecuencias para el problema de la interpretación. La filosofía de la razón vital de Ortega se fundamenta en el concepto de vida humana como realidad radical y principio interpretativo universal, y por esta razón se presenta desde el principio como una filosofía hermenéutica de la vida y no como una reducción hacia la conciencia trascendental. Esta hermenéutica se practica especialmen...

Hydroxyl radical reactivity with diethylhydroxylamine

International Nuclear Information System (INIS)

Gorse, R.A. Jr.; Lii, R.R.; Saunders, B.B.

1977-01-01

Diethylhydroxylamine (DEHA) reacts with gas-phase hydroxyl radicals on every third collision, whereas the corresponding reaction in aqueous solution is considerably slower. The high gas-phase reactivity explains the predicted inhibitory effect of DEHA in atmospheric smog processes. Results from the studies in the aqueous phase are helpful in predicting the mechanism of the reaction of DEHA with hydroxyl radicals

Radical dematerialization and degrowth

Science.gov (United States)

Kallis, Giorgos

2017-05-01

The emission targets agreed in Paris require a radical reduction of material extraction, use and disposal. The core claim of this article is that a radical dematerialization can only be part and parcel of degrowth. Given that capitalist economies are designed to grow, this raises the question of whether, and under what circumstances, the inevitable `degrowth' can become socially sustainable. Three economic policies are discussed in this direction: work-sharing, green taxes and public money. This article is part of the themed issue 'Material demand reduction'.

Thermal evolution of the morphology of Ni/Ag/Si(111)-{radical}3 Multiplication-Sign {radical}3 surface

Energy Technology Data Exchange (ETDEWEB)

Tomaszewska, Agnieszka; Huang, Xiao-Lan; Chang, Kuo-Wei; Fu, Tsu-Yi, E-mail: phtifu@phy.ntnu.edu.tw

2012-08-31

The temperature-driven changes in morphology of the interface formed by room temperature (RT) deposition of Ni atoms onto an Ag/Si(111)-{radical}3 Multiplication-Sign {radical}3 surface were investigated by scanning tunneling microscopy. Roughly 70% of Ni deposition diffused into bulk substrate within the temperature range between RT and 573 K. The images as obtained after annealing up to 670 K correspond to the formation of nano-sized islands of nickel silicides. Two types of islands, large triangular islands typical of the whole range of applied coverage, and smaller islands of different shapes, coexist at Ni coverage higher than 1 monolayer. Annealing above 870 K led to the formation of a 7 Multiplication-Sign 7 phase in coexistence with small 5 Multiplication-Sign 5 domains at the expense of a complete disappearance of the {radical}3 Multiplication-Sign {radical}3 phase. Also, formation of Ni,Si alloy was observed at the temperature, along with segregation of bulk-dissolved Ni species onto the surface. - Highlights: Black-Right-Pointing-Pointer We examine changes in morphology of Ni/Ag/Si(111)-{radical}3 Multiplication-Sign {radical}3 surface upon annealing. Black-Right-Pointing-Pointer 70% of deposited Ni atoms diffuse into the bulk after annealing at 570 K. Black-Right-Pointing-Pointer A variety of nano-sized Ni, Si islands develops after annealing at 670 K. Black-Right-Pointing-Pointer 5 Multiplication-Sign 5 reconstruction as an evidence for mass transport during the island growth.

Ring-Expansion/Contraction Radical Crossover Reactions of Cyclic Alkoxyamines: A Mechanism for Ring Expansion-Controlled Radical Polymerization

Directory of Open Access Journals (Sweden)

Atsushi Narumi

2018-06-01

Full Text Available Macrocyclic polymers present an important class of macromolecules, displaying the reduced radius of gyration or impossibility to entangle. A rare approach for their synthesis is the ring expansion-controlled radical “vinyl” polymerization, starting from a cyclic alkoxyamine. We here describe ring-expansion radical crossover reactions of cyclic alkoxyamines which run in parallel to chain-propagation reactions in the polymerization system. The radical crossover reactions extensively occurred at 105–125 °C, eventually producing high molecular weight polymers with multiple inherent dynamic covalent bonds (NOC bonds. A subsequent ring-contraction radical crossover reaction and the second ring-expansion radical crossover reaction are also described. The major products for the respective three stages were shown to possess cyclic morphologies by the molecular weight profiles and the residual ratios for the NOC bonds (φ in %. In particular, the high φ values ranging from ca. 80% to 98% were achieved for this cyclic alkoxyamine system. This result verifies the high availability of this system as a tool demonstrating the ring-expansion “vinyl” polymerization that allows them to produce macrocyclic polymers via a one-step vinyl polymerization.

Biochemistry and pathology of radical-mediated protein oxidation

DEFF Research Database (Denmark)

Dean, R T; Fu, S; Stocker, R

1997-01-01

Radical-mediated damage to proteins may be initiated by electron leakage, metal-ion-dependent reactions and autoxidation of lipids and sugars. The consequent protein oxidation is O2-dependent, and involves several propagating radicals, notably alkoxyl radicals. Its products include several catego...

How to counter radical narratives: Dutch deradicalization policy in the case of Moluccan and Islamic radicals

NARCIS (Netherlands)

Demant, F.; de Graaf, B.

2010-01-01

This article deals with the role of government in encouraging the decline of radical movements. The question posed is: "Which story can the government tell to encourage the decline of radical groups and the disengagement of their members?" The article makes use of the survey of factors promoting

Structure and Reactivity of the Glutathione Radical Cation: Radical Rearrangement from the Cysteine Sulfur to the Glutamic Acid alpha-Carbon Atom

NARCIS (Netherlands)

Osburn, S.; Berden, G.; Oomens, J.; Gulyuz, K.; Polfer, N.C.; O'Hair, R.A.J.; Ryzhov, V.

2013-01-01

A gas-phase radical rearrangement through intramolecular hydrogen-atom transfer (HAT) was studied in the glutathione radical cation, [-ECG](+.), which was generated by a homolytic cleavage of the protonated S-nitrosoglutathione. Ion-molecule reactions suggested that the radical migrates from the

Photodynamically generated bovine serum albumin radicals

DEFF Research Database (Denmark)

Silvester, J A; Timmins, G S; Davies, Michael Jonathan

1998-01-01

Porphyrin-sensitized photoxidation of bovine serum albumin (BSA) results in oxidation of the protein at (at least) two different, specific sites: the Cys-34 residue giving rise to a thiyl radical (RS.); and one or both of the tryptophan residues (Trp-134 and Trp-214) resulting in the formation...... of tertiary carbon-centred radicals and disruption of the tryptophan ring system. In the case of porphyrins such as hematoporphyrin, which bind at specific sites on BSA, these species appear to arise via long-range transfer of damage within the protein structure, as the binding site is some distance from...... the ultimate site of radical formation. This transfer of damage is shown to depend on a number of factors including the conformation of the protein, the presence of blocking groups and pH. Alteration of the protein conformation results in radical formation at additional (or alternative) sites, as does blocking...

The Rise of Radicals in Bioinorganic Chemistry

OpenAIRE

Gray, Harry B.; Winkler, Jay R.

2016-01-01

Prior to 1950, the consensus was that biological transformations occurred in two-electron steps, thereby avoiding the generation of free radicals. Dramatic advances in spectroscopy, biochemistry, and molecular biology have led to the realization that protein-based radicals participate in a vast array of vital biological mechanisms. Redox processes involving high-potential intermediates formed in reactions with O_2 are particularly susceptible to radical formation. Clusters of tyrosine (Tyr) a...

Radical prostatectomy. Results and indications

International Nuclear Information System (INIS)

Jacqmin, D.

1997-01-01

Radical prostatectomy is the surgical curative treatment of localized prostate cancer. The survival is good in young patients (<70) with T2 N0M0 tumors and more than 10 year's life expectancy. Side-effects are urinary incontinence, impotence and anastomosis stricture. Quality of life should be considered as an important factor for the choice of the patient between radical prostatectomy, radiotherapy and follow-up. (author)

Hacia la formalización del diseño de bases de datos orientadas a objetos

Directory of Open Access Journals (Sweden)

Victor Hugo Medina García

2015-02-01

Full Text Available RESUMEN El presente estudio tiene como bases: la ingeniería de software, las metodologías estructurales de desarrollo de software, las bases de datos como componentes esenciales e inseparables de la gran mayoría de sistemas de información, el concepto de herramientas CASE (Ingeniería de software asistida por computador, y la teoría paradigmas, en los que ya se vislumbran soluciones. El carácter de este estudio es investigativo y exploratorio dentro del área de la formalización del diseño de bases de datos orientadas a objetos...

El epiLASIK como tratamiento en pacientes miopes con córneas de espesor reducido

OpenAIRE

Sabino Borreguero, Sara

2011-01-01

La principal hipótesis de este trabajo es que la que se plantea a continuación: “La técnica quirúrgica de ablación de superficie Queratectomía epitelial asistida por láser (epiLASIK) es un procedimiento predictible, seguro y eficaz en pacientes miopes con espesor de cornea central (ECC) menor de 500 micrómetros”. Tras la formulación de dicha hipótesis, el principal objetivo que se persigue en este trabajo es evaluar si los pacientes con ECC mayor y menor de 500 micrones tienen una buena...

Necesidad de Incluir el Delito de Contrato de Maternidad Subrogada en el Código Penal Peruano

OpenAIRE

Velásquez Vargas, Marlene Susana

2015-01-01

A continuación una síntesis de los datos, resultados, discusión, conclusiones y recomendaciones obtenidas en el presente trabajo investigativo con los siguientes contenidos: la descripción y estudio de las tecnologías de reproducción asistida, sus distintas técnicas y la maternidad subrogada, su modalidad como contrato y su sanción en otras legislaciones. En la investigación entrevistas a médicos, jueces y a la ciudadanía, en cuyos resultados se demostró la poca aceptación por parte de l...

Selección de embriones humanos. Diagnóstico genético preimplantación

OpenAIRE

Natalia López Moratalla; Marta Lago Fernández Purón; Esteban Santiago

2011-01-01

La posibilidad de detectar defectos cromosómicos o genéticos en embriones in vitro, asociada a las técnicas de Reproducción Humana Asistida antes de su posible transferencia a útero para completar su desarrollo, se presentó como una alternativa al aborto eugenésico. Y una opción para mujeres de edad avanzada para procrear, de evitar embarazos de embriones con defectos cromosómicos. El diagnóstico genético previo a la implantación (DGP) y el cribado de los embriones in vitro (por las siglas en...

Embarazo gemelar

OpenAIRE

Gustavo Rencoret, P.

2014-01-01

El embarazo gemelar se presenta en 1 de cada 100 embarazos y su frecuencia ha aumentado en los últimos años como resultado de técnicas de fertilización asistida y la mayor edad materna. Por definición, es un embarazo de alto riesgo dado su mayor asociación con enfermedades del embarazo. El parto prematuro es la principal complicación, seguido de síndromes hipertensivos y restricción de crecimiento fetal. Hay complicaciones específicas de la placentación gemelar, como la transfusión feto fetal...

Responsibility for radical change in addressing climate change

NARCIS (Netherlands)

Bouvrie, des N.; Karlsson-Vinkhuyzen, S.I.S.E.; Jollands, N.

2015-01-01

To radically address the problem of climate change, it is not enough to modify specific attitudes and behaviors while upholding the present paradigms. This article aims to show why modifications will never bring about radical carbon emission reductions. We discuss what it implies to desire radical

O rap radical e a "nova classe média"

Directory of Open Access Journals (Sweden)

Ricardo Indig Teperman

2015-04-01

Full Text Available Este artigo discute a recente alteração na posição relativa do rap e dos rappers no campo da produção cultural no Brasil. O grupo Racionais MCs, tão central no campo do rap nacional que acaba por determinar a tendência hegemônica do gênero, vem se afastando do posicionamento revolucionário que marcou seus primeiros anos. Proponho que o aumento do poder de consumo e a democratização do acesso à tecnologia e à educação são aspectos que marcam a experiência da nova geração do rap (a chamada "nova escola", personificada em Emicida, e que provocaram o reposicionamento do Racionais. Recupero uma formulação de Antonio Candido para propor que essa nova posição pode ser considerada "radical".

Measurements of hydroxyl and hydroperoxy radicals during CalNex-LA: Model comparisons and radical budgets

Science.gov (United States)

Griffith, S. M.; Hansen, R. F.; Dusanter, S.; Michoud, V.; Gilman, J. B.; Kuster, W. C.; Veres, P. R.; Graus, M.; de Gouw, J. A.; Roberts, J.; Young, C.; Washenfelder, R.; Brown, S. S.; Thalman, R.; Waxman, E.; Volkamer, R.; Tsai, C.; Stutz, J.; Flynn, J. H.; Grossberg, N.; Lefer, B.; Alvarez, S. L.; Rappenglueck, B.; Mielke, L. H.; Osthoff, H. D.; Stevens, P. S.

2016-04-01

Measurements of hydroxyl (OH) and hydroperoxy (HO2*) radical concentrations were made at the Pasadena ground site during the CalNex-LA 2010 campaign using the laser-induced fluorescence-fluorescence assay by gas expansion technique. The measured concentrations of OH and HO2* exhibited a distinct weekend effect, with higher radical concentrations observed on the weekends corresponding to lower levels of nitrogen oxides (NOx). The radical measurements were compared to results from a zero-dimensional model using the Regional Atmospheric Chemical Mechanism-2 constrained by NOx and other measured trace gases. The chemical model overpredicted measured OH concentrations during the weekends by a factor of approximately 1.4 ± 0.3 (1σ), but the agreement was better during the weekdays (ratio of 1.0 ± 0.2). Model predicted HO2* concentrations underpredicted by a factor of 1.3 ± 0.2 on the weekends, while measured weekday concentrations were underpredicted by a factor of 3.0 ± 0.5. However, increasing the modeled OH reactivity to match the measured total OH reactivity improved the overall agreement for both OH and HO2* on all days. A radical budget analysis suggests that photolysis of carbonyls and formaldehyde together accounted for approximately 40% of radical initiation with photolysis of nitrous acid accounting for 30% at the measurement height and ozone photolysis contributing less than 20%. An analysis of the ozone production sensitivity reveals that during the week, ozone production was limited by volatile organic compounds throughout the day during the campaign but NOx limited during the afternoon on the weekends.

An Appreciation of Free Radical Chemistry

Indian Academy of Sciences (India)

... Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 9. An Appreciation of Free Radical Chemistry - 6. Experiments Involving Free Radicals. G Nagendrappa. Classroom Volume 10 Issue 9 September 2005 pp 79-84 ...

Reorientation dynamics of cyclohexadienyl radicals in zeolites

International Nuclear Information System (INIS)

Stolmar, M.; Roduner, E.; Dilger, H.; Himmer, U.; Shelley, M.; Reid, I.D.

1997-01-01

The dynamics of the muonium substituted cyclohexadienyl radical adsorbed on silicalite and NaZSM-5 is investigated by means of avoided level crossing muon spin resonance. The influence of benzene loading on the mobility of the radical is studied. At low loadings the radicals were found to be located on a single adsorption site where they undergo a wobbling type of motion. With increasing loading an additional species adsorbed on a different site is observed

Interactions between simple radicals and water

International Nuclear Information System (INIS)

Crespo-Otero, Rachel; Sanchez-Garcia, Elsa; Suardiaz, Reynier; Montero, Luis A.; Sander, Wolfram

2008-01-01

The interactions of the simple radicals CH 3 , NH 2 , OH, and F with water have been studied by DFT (UB3LYP/6-311++G(2d,2p)) and ab initio (RHF-UCCSD(T)/6-311++G(2d,2p)) methods. In this order the number of lone pairs (from zero to three), the electronegativity, and the strength of the X-H bonds increase (X = C, N, and O). The various minima of the radical-water complexes were located using the multiple minima hypersurface (MMH) approach which had previously been proven to be useful for closed-shell molecules. The role of the unpaired electron in hydrogen bonding was investigated using the natural bond orbital (NBO) analysis. A considerable contribution of the unpaired electron to the complex stabilization was only found for the methyl radical and the fluorine atom, whereas in the aminyl and the hydroxyl radical the role of the unpaired electron is negligible

Muon level crossing resonance spectroscopy applied to free-radical formation

International Nuclear Information System (INIS)

Venkateswaran, K.; Barnabas, M.V.; Walker, D.C.

1989-01-01

Muon Level Crossing Resonance Spectroscopy has been used to explore two aspects of muonium chemistry: unique free radicals and muonated radical yields. (1) A variety of new free-radicals have been seen by LCR. For instance, in thioacetamide the only radical produced from muonium is the S sm-bullet radical formed when Mu adds to the C of the C=S bond. In allylbenzene a whole range of radicals form with substantial yields (two side-chain and three ring additions); whereas in styrene, 85% of the radicals have Mu bonded to the end C of the side-chain and there is no meta-adduct at all. (2) Absolute yields of the radicals formed by interaction of muonium atoms in water with acrylamide as a solute (and with benzene in n-hexane) have shown that all muons not directly incorporated into diamagnetic molecules (such as MuH) appear as muonated free radicals. i.e. the missing fraction is found

Geminate free radical processes and magnetic field effects

International Nuclear Information System (INIS)

Eveson, Robert W.

2000-01-01

This thesis is concerned with the study of the dynamics of radical pair recombination reactions in solution by flash photolysis Electron Spin Resonance (ESR) and the influence of low static external magnetic fields upon them (MFE). An outline of the concepts of ESR is presented, followed by the theories of Chemically Induced Dynamic Electron Polarisation (CIDEP) of transient radical pairs. This is then followed by a brief review of the flash photolysis ESR apparatus and application of the Bloch equations to solve the equations of time-resolved ESR. Completing the theory section is an overview of the mechanisms by which magnetic fields alter the course of a geminate radical pair reaction in solution. Experimental CIDEP observations of the radical pair produced on photolysis of 1,3-dihydroxypropanone are simulated using polarisation theory and applied to a random-walk diffusion model to find, for the first time, the geminate reaction probability in solutions of varying viscosity. CIDEP spectra of the radical pair formed on photolysis of hydroxypropanone in contrast are not accounted for by current polarisation theory. The discrepancy is due to moderately fast relaxation of the acyl radical, CH 3 CO·, which alters the relative intensities in the ST 0 RPM pattern of the counter radical. Calculations taking into account this now provide an adequate basis for simulation of the spectrum. This method also, in principle, represents a new method for the measurement of phase relaxation times. Concluding the ESR work is a CIDEP study of 2,4,6-trimethylbenzoyl diphenylphosphine oxide. Unusual spin polarisation phenomena are found. The time-resolved optical absorption spectroscopy technique used for detecting low magnetic field effects on neutral radical pair reactions is described. Various improvements to the experiment are discussed which result in the observation of the low field effect for a neutral radical pair produced by Norrish type II chemistry. This is followed by an

Reproducción en hembras bufalinas: inseminación artificial y reproducción asistida

Directory of Open Access Journals (Sweden)

William G. Vale

2011-11-01

Full Text Available El uso de semen congelado de la especie bufalina en la Inseminación Artificial (IA se realizó por primera vez por Bhattacharya y Srivastava (1955 en la India. Luego, continuaron varios estudios realizados en diferentes países, Roy et al. (1956, Basirov (1964, Allahverdiev (1969 y Sahana y Roy (1972. Sin embargo, la ausencia de un procesamiento tecnológico adecuado del esperma en lo que se refiere a los diluyentes, el de tiempo de equilibración, concentración de glicerol, métodos de congelación y la falta de un estándar adecuado llevó a resultados pobres y variables. Toda la tecnología de procesamiento se basó en la misma metodología utilizada para el ganado bovino, faltando por lo tanto, el desarrollo de un diluyente especifico para bufalinos. Después del seminario sobre la reproducción y la inseminación artificial, promovido por la FAO y el Gobierno Sueco, en Karnal, India en 1979, varias mejoras se obtuvieron en los laboratorios de diferentes partes del mundo, lo cual culminó en el uso de diluyentes aptos para el semen de búfalo y la obtención de tasas nacimiento mayores al 65% (Sengupta y Sukhija, 1988.En Brasil, la práctica de la IA en los bufalinos comenzó en los años 80 del pasado siglo, cuando Vale et al. (1984 al utilizar los diluyentes TES y TRIS realizaron con éxito la primera inseminación con semen congelado en la región amazónica, con el cual logró tasas de preñez superiores a 50%. Posteriormente, tasas superiores al 70% de nacimientos fueron obtenidas por los mismos investigadores, iniciando el uso del proceso ampliamente en todo Brasil y América Latina. En otros países de América Latina, incluyendo Brasil se registran índices de nacimientos arriba del 80%, mientras que en China hay datos oficiales que reportan índices de fertilidad alrededor del 90% en búfalas inseminadas en municipios rurales. Por lo tanto, hoy en día la inseminación artificial en hatos de búfalos llega a la misma tasa de

1,2-Fluorine Radical Rearrangements: Isomerization Events in Perfluorinated Radicals.

Science.gov (United States)

Van Hoomissen, Daniel J; Vyas, Shubham

2017-11-16

Devising effective degradation technologies for perfluoroalkyl substances (PFASs) is an active area of research, where the molecular mechanisms involving both oxidative and reductive pathways are still elusive. One commonly neglected pathway in PFAS degradation is fluorine atom migration in perfluoroalkyl radicals, which was largely assumed to be implausible because of the high C-F bond strength. Using density functional theory calculations, it was demonstrated that 1,2-F atom migrations are thermodynamically favored when the fluorine atom migrated from a less branched carbon center to a more branched carbon center. Activation barriers for these rearrangements were within 19-29 kcal/mol, which are possible to easily overcome at elevated temperatures or in photochemically activated species in the gas or aqueous phase. It was also found that the activation barriers for the 1,2-F atom migration are lowered as much as by 10 kcal/mol when common oxidative degradation products such as HF assisted the rearrangements or if the resulting radical center was stabilized by vicinal π-bonds. Natural bond orbital analyses showed that fluorine moves as a radical in a noncharge-separated state. These findings add an important reaction to the existing knowledge of mechanisms for PFAS degradation and highlights the fact that 1,2-F atom shifts may be a small channel for isomerization of these compounds, but upon availability of mineralization products, this isomerization process could become more prominent.

Comparative study of radical oxidation of DNA and its nucleosides by hydroxyl radicals and ferryl ions generated by the Fenton reaction

International Nuclear Information System (INIS)

Mouret, J.F.; Berger, M.; Anselmino, C.; Polverelli, M.; Cadet, J.

1991-01-01

A comparative study of the reaction of hydroxyl radicals and Fenton type oxidative species with DNA and 2'-deoxyribonucleosides was investigated. This study was based on the characterization of the diamagnetic products resulting from the chemical transformation of the transient radicals. Emphasis was placed on the radical oxidative reactions of the purine nucleosides. It is interesting to note that oxidative purine radicals can be reduced by reagents such as ascorbic acid or N,N,N',N'-tetramethyl-1, 4-p-phenylenediamine. The observed differences in the nature of the decomposition products resulting from the Fenton reaction are not consistent with the nature of the oxidative species (hydroxyl radicals or ferryl ions) involved, but due to the presence of ferrous sulfate [fr

Photoactivation of isoflavonoid phytoalexins: involvement of free radicals

International Nuclear Information System (INIS)

Bakker, J.; Gommers, F.J.; Smits, L.; Fuchs, A.; Vries, F.W. de

1983-01-01

Ultraviolet irradiation of isoflavonoid phytoalexins phaseollin, 3.6a. 9-trihydroxypterocarpan, glyceollin, tuberosin and pisatin, but not medicarpin, brought about inactivation of glucose-6-phosphate dehydrogenase in an in vitro assay system. Photoinactivation of the enzyme by photoactivated pisatin in air-saturated solutions was hardly affected by singlet oxygen quenchers such as NaN 3 , bovine serum albumin, histidine or methionine. Neither addition of the hydroxyl radical scavengers mannitol, Na-benzoate and ethanol nor the presence of catalase or superoxide dismutase protected the enzyme against photoinactivation, suggesting that OHradical, H 2 O 2 and O 2 radical are not the reactive oxygen species involved. However, the free radical scavenger S-(2-amino-ethyl)isothiouronium bromide hydrobromide (AET) protected the enzyme against inactivation by photoactivated pisatin. Direct evidence for the generation of free radicals was obtained by ESR measurements of solutions of phaseollin, pisatin and medicarpin in hexane irradiated with ultraviolet light in the presence or absence of O 2 . Phaseollin produced the most stable free radicals, whereas medicarpin hardly gave rise to free radical formation; pisatin took a somewhat intermediate position by producing a strong ESR signal which, however, decayed rather quickly. These results indicate free radical formation as the cause for photoinactivation of enzymes by photoactivated isoflavonoid phytoalexins. (author)

Enhancing production through optimisation of DPPH and radical ...

African Journals Online (AJOL)

... of dry matter for DPPH radical scavenging activity. Methanol had the lowest value (78 mg g-1 dry matter) for polyphenol extracts and 80 mg g-1 for the DPPH radical scavenging activity. The main extract compounds were gallic acid, catechin and epicatechin. Key Words: High density lipids, polyphenol, radical scavenging ...

Hydroxyl-radical induced dechlorination of pentachlorophenol in water

International Nuclear Information System (INIS)

He Yongke; Wu Jilan; Fang Xingwang; Sonntag, C. von

1998-01-01

The hydroxyl-radical induced dechlorination of pentachlorophenol (PCP) in water has been investigated pulse radiolytically. Hydroxyl radicals react with PCP by both electron transfer and addition. The former process results in pentachlorophenoxyl radicals (PCP-O), the latter process followed by rapid HCl elimination gives birth to deprotonated hydroxytetrachlorophenoxyl radicals ( - O-TCP-O). These phenoxyl radicals exhibit maximum absorption around 452 nm, which hinders the proper estimation of the ratio of the two processes. However, these two processes cause different changes in conductivity. In basic solution, the electron transfer causes a conductivity increase due to the formation of OH - whereas an addition followed by HCl elimination results in a conductivity decrease. The concurrence of these two processes reduces the relative variation in conductivity, from which about 53% electron transfer is deduced

Exploring the Theories of Radicalization

Directory of Open Access Journals (Sweden)

Maskaliūnaitė Asta

2015-12-01

Full Text Available After the London bombings in July 2005, the concern of terrorism scholars and policy makers has turned to “home-grown” terrorism and potential for political violence from within the states. “Radicalization” became a new buzz word. This article follows a number of reviews of the literature on radicalization and offers another angle for looking at this research. First, it discusses the term “radicalization” and suggests the use of the following definition of radicalization as a process by which a person adopts belief systems which justify the use of violence to effect social change and comes to actively support as well as employ violent means for political purposes. Next, it proposes to see the theories of radicalization focusing on the individual and the two dimensions of his/her motivation: whether that motivation is internal or external and whether it is due to personal choice or either internal (due to some psychological traits or external compulsion. Though not all theories fall neatly within these categories, they make it possible to make comparisons of contributions from a variety of different areas thus reflecting on the interdisciplinary nature of the study of terrorism in general and radicalization as a part of it.

Superoxide radical (O2-) reactivity with respect to glutathione

International Nuclear Information System (INIS)

Sekaki, A.; Gardes-Albert, M.; Ferradini, C.

1984-01-01

Influence of superoxide radicals formed during gamma irradiation of glutathione in aerated aqueous solutions is examined. Solutions are buffered at pH7 and contain sodium formate for capture of H and OH radicals which are transformed in COO - radicals and then O 2 - radicals. G value of glutathione disparition vs glutathione concentration are given with and without enzyme or catalase. Reaction mechanism are interpreted [fr

Reactions of melatonin with radicals in deoxygenated aqueous solution

International Nuclear Information System (INIS)

Stasica, P.; Ulanski, P.; Rosiak, J.M.

1998-01-01

Reactions of melatonin (N-acetyl-5-methoxytryptamine) with radiolytically generated radicals were studied. Reaction of melatonin with OH radicals is diffusion-controlled (k=1.2 x 10 10 dm 3 mol -1 x s -1 ), the main (but not the only one) intermediate being the indolyl-type radical, while the rate constant for the reaction with hydrated electrons is k=4.3 x 10 8 dm 3 x mol -1 x s -1 . Melatonin is capable of scavenging tert-butanol radicals, while its reactivity towards polymer radicals of poly(acrylic acid) and poly(vinyl pyrrolidone) is very low. (author)

O behaviorismo radical e a interdisciplinaridade: possibilidade de uma nova síntese? Radical behaviorism and interdisciplinary research: would a new synthesis be possible in psychology?

Directory of Open Access Journals (Sweden)

Evenice Santos Chaves

2005-12-01

Full Text Available A ciência psicológica é historicamente atravessada por conflitos inter teóricos, decorrentes de enfoques diferenciados com relação a conhecimentos produzidos pelos fundamentos epistemológicos, teóricos e metodológicos, pelas hegemonias e pelo próprio recorte sobre o objeto em estudo, realizado por pesquisadores. Contemporaneamente, a epistemologia da complexidade chama atenção para a incompletude de cada tipo de conhecimento científico produzido, o que tem gerado ressonâncias nos fazeres de pesquisadores e propiciado novos diálogos entre perspectivas diversificadas em cada enfoque, ou entre enfoques. O presente artigo propõe diálogos entre aspectos do behaviorismo radical e do construtivismo crítico formal, ressaltando relações de complementaridade, a partir da unidade de contrários, que podem implicar numa nova síntese: uma teoria geral do significado. Nessa direção enfocar-se-á a proposição de nova síntese, a qual configura uma compreensão teórica sobre o desenvolvimento do significado e reinterpreta o papel do reforçamento na construção e ampliação dos significados.Psychology as science is historically engaged in theoretical disputes resulting from divergent viewpoints concerning the nature of knowledge generated by different epistemological, theoretical and methodological approaches, and by the particular divisions in the subject matter made by the researchers themselves. At the present time, epistemology of the complexity calls attention to the incompleteness, characteristic of scientific knowledge, that in turn affects the conduct of researchers, creating conditions for new dialogues between differing perspectives within and between disciplines. This article proposes a renewal of the dialogue between radical behaviorism and formal critical constructivism that, by emphasizing complementary relationships and opposing polarized thinking which has permeated these disciplines, may result in a new synthesis or

Sulfate radical-based water treatment in presence of chloride: formation of chlorate, inter-conversion of sulfate radicals into hydroxyl radicals and influence of bicarbonate.

Science.gov (United States)

Lutze, Holger V; Kerlin, Nils; Schmidt, Torsten C

2015-04-01

Sulfate radical (SO4(-)) based oxidation is discussed as a potential water treatment option and is already used in ground water remediation. However, the complex SO4(-) chemistry in various matrices is poorly understood. In that regard, the fast reaction of SO4(-) with Cl(-) is of high importance since Cl(-) belongs to the main constituents in aqueous environments. This reaction yields chlorine atoms (Cl) as primary products. Cl initiate a cascade of subsequent reactions with a pH dependent product pattern. At low pH ( 5 Cl mainly react with water yielding hydroxyl radicals. Thus, at moderate Cl(-) concentrations (mM range) the SO4(-)-based process may be converted into a conventional (hydroxyl radical -based) advanced oxidation process. The conversion of SO4(-) into OH, however, is interrupted in presence of bicarbonate by scavenging of Cl. Copyright © 2014. Published by Elsevier Ltd.

Free radical scavenging injectable hydrogels for regenerative therapy.

Science.gov (United States)

Komeri, Remya; Thankam, Finosh Gnanaprakasam; Muthu, Jayabalan

2017-02-01

Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

IRON AND FREE RADICAL OXIDATIONS IN CELL MEMBRANES

Science.gov (United States)

Schafer, Freya Q.; Yue Qian, Steven; Buettner, Garry R.

2013-01-01

Brain tissue being rich in polyunsaturated fatty acids, is very susceptible to lipid peroxidation. Iron is well known to be an important initiator of free radical oxidations. We propose that the principal route to iron-mediated lipid peroxidations is via iron-oxygen complexes rather than the reaction of iron with hydrogen peroxide, the Fenton reaction. To test this hypothesis, we enriched leukemia cells (K-562 and L1210 cells) with docosahexaenoic acid (DHA) as a model for brain tissue, increasing the amount of DHA from approximately 3 mole % to 32 mole %. These cells were then subjected to ferrous iron and dioxygen to initiate lipid peroxidation in the presence or absence of hydrogen peroxide. Lipid-derived radicals were detected using EPR spin trapping with α-(4-pyridyl-1-oxide)-N-t-butylnitrone (POBN). As expected, lipid-derived radical formation increases with increasing cellular lipid unsaturation. Experiments with Desferal demonstrate that iron is required for the formation of lipid radicals from these cells. Addition of iron to DHA-enriched L1210 cells resulted in significant amounts of radical formation; radical formation increased with increasing amount of iron. However, the exposure of cells to hydrogen peroxide before the addition of ferrous iron did not increase cellular radical formation, but actually decreased spin adduct formation. These data suggest that iron-oxygen complexes are the primary route to the initiation of biological free radical oxidations. This model proposes a mechanism to explain how catalytic iron in brain tissue can be so destructive. PMID:10872752

ESR study of the anion radicals of 5-nitropyrimidines: conversion to iminoxy radicals

International Nuclear Information System (INIS)

Sevilla, M.D.; Clark, C.; Failor, R.

1976-01-01

The anion radicals of a number of 5-nitropyrimidines have been investigated by ESR spectroscopy. The anions are formed by electrolysis in dimethylformamide and by electron attachment in aqueous glasses, 12 M LiCl--D 2 O and 8 M NaOD. The electrolysis of 5-nitrouracil and 5-nitro-6-methyluracil results in relatively stable anion radicals. The results for 5-nitrouracil give evidence for two or perhaps three anions which differ only by the degree of ring nitrogen protonation. The results for 5-nitro-6-methyluracil suggest that the nitro group of the anion is twisted so that it is coupled only weakly to the ring π-electron system. The anions of 5-nitrouracil, 5-nitroorotic acid, 5-nitrobarbituric acid, and 5-nitro-6-methyluracil have been produced in the alkaline and neutral aqueous glasses. The anisotropic spectra found have been analyzed with the aid of computer simulations which assume axial symmetry. For example, the analysis of the spectrum of 5-nitrouracil anion in 12 M LiCl yields A/sub parallel//sup N/ = 33; A/sub perpendicular to//sup N/ = 5, a 6 /sup H/ = 5.5 G, g/sub parallel/ = 2.0016, and g/sub perpendicular to/ = 2.0059. A concentration dependence in the splittings is noted and discussed. Ultraviolet photolysis of the anions of 5-nitro-6-methyluracil and 5-nitrobarbituric acid results in the formation of iminoxy radicals. Mechanisms of formation of the iminoxy radicals are discussed and results found in this work are compared to results found in single crystals and aqueous solution

Comparison of Nerve-Sparing Radical Hysterectomy and Radical Hysterectomy: a Systematic Review and Meta-Analysis

Directory of Open Access Journals (Sweden)

Zhuowei Xue

2016-05-01

Full Text Available Background/Aims: Radical hysterectomy (RH for the treatment of cervical cancer frequently caused pelvic organ dysfunctions. This study aimed to compare the results of pelvic organ function and recurrence rate after Nerve sparing radical hysterectomy (NSRH and RH treatment through systematic review and meta-analysis. Methods: PubMed, Web of Science and China Knowledge Resource Integrated Database were searched from inception to 25 February 2015. Studies of cervical cancer which reported radical hysterectomy or nerve sparing radical hysterectomy were included. The quality of included studies was evaluated using the guidelines of Cochrane Handbook for Systematic Reviews of Interventions. Statistical analysis was performed using Review Manager 5.3 software (Cochrane Collaboration. Results: A total of 20 studies were finally included. Meta-analysis demonstrated that NSRH was associated with less bladder and anorectal dysfunction than RH. The time to bladder and anorectal function recovery after NSRH was shorter than RH. Patients undergoing NSRH also scored higher than patients undergoing RH at Female Sexual Function Index (FSFI. On the other hand, the local recurrence and overall recurrence rate were similar between NSRH and RH. Conclusion: NSRH may be an effective technique for lowering pelvic organ dysfunction and improving the function recovery without increasing the recurrence rate of cervical cancer.

Flavonoids as scavengers of nitric oxide radical.

NARCIS (Netherlands)

van Acker, S.A.B.E.; Tromp, M.N.J.L.; Haenen, G.R.M.M.; van der Vijgh, W.J.F.; Bast, A.

1995-01-01

Flavonoids are a group of naturally occurring compounds used, e.g., in the treatment of vascular endothelial damage. They are known to be excellent scavengers of oxygen free radicals. Since the nitric oxide radical (

Progress on resonance ionization detection of combustion radicals

International Nuclear Information System (INIS)

Cool, T.A.

1994-01-01

Selective laser ionization techniques are used in our laboratory for the measurement of concentration profiles of radical intermediates in the combustion of chlorinated hydrocarbon flames. A new ultrasensitive detection technique, made possible with the advent of tunable VUV laser sources, enables the selective near-threshold photoionization of all radical intermediates in premixed hydrocarbon and chlorinated hydrocarbon flames. The progress made on the following three separate experiments during the past year is briefly described in this report. Flame Radical Concentration Measurements with VUV Spectroscopy; observation of hyperfine quantum beats in cyanogen; and the spectroscopy of the ClCO radical

Radical production in the radiolysis of benzene

International Nuclear Information System (INIS)

LaVerne, J.A.; Araos, M.S.

1998-01-01

Complete text of publication follows. Benzene is the prototypical aromatic compound and yet the radiation chemistry of the radicals formed in its radiolysis is not well understood. Temporal information on the yield of phenyl radical, the major radical produced in the radiolysis, is important for understanding the radiation chemistry of many other types of aromatic compounds including some polymers. The effects of track structure on the production of phenyl radicals have been examined using iodine-scavenging techniques. The variation of the yields of iodobenzene and the other major molecular products such as biphenyl as a function of iodine concentration gives a good indication of the competition kinetics occurring in particle tracks. Experimental results of the scavenger experiments will be shown and their implications in the radiolysis of condensed hydrocarbons will be discussed

Even free radicals should follow some rules: a guide to free radical research terminology and methodology.

Science.gov (United States)

Forman, Henry Jay; Augusto, Ohara; Brigelius-Flohe, Regina; Dennery, Phyllis A; Kalyanaraman, Balaraman; Ischiropoulos, Harry; Mann, Giovanni E; Radi, Rafael; Roberts, L Jackson; Vina, Jose; Davies, Kelvin J A

2015-01-01

Free radicals and oxidants are now implicated in physiological responses and in several diseases. Given the wide range of expertise of free radical researchers, application of the greater understanding of chemistry has not been uniformly applied to biological studies. We suggest that some widely used methodologies and terminologies hamper progress and need to be addressed. We make the case for abandonment and judicious use of several methods and terms and suggest practical and viable alternatives. These changes are suggested in four areas: use of fluorescent dyes to identify and quantify reactive species, methods for measurement of lipid peroxidation in complex biological systems, claims of antioxidants as radical scavengers, and use of the terms for reactive species. Copyright © 2014 Elsevier Inc. All rights reserved.

Alkyl Radicals as Hydrogen Bond Acceptors: Computational Evidence

DEFF Research Database (Denmark)

Hammerum, Steen

2009-01-01

Spectroscopic, energetic and structural information obtained by DFT and G3-type computational studies demonstrates that charged proton donors can form moderately strong hydrogen bonds to simple alkyl radicals. The presence of these bonds stabilizes the adducts and modifies their structure......, and gives rise to pronounced shifts of IR stretching frequencies and to increased absorption intensities. The hydrogen bond acceptor properties of alkyl radicals equal those of many conventional acceptors, e.g., the bond length changes and IR red-shifts suggest that tert-butyl radicals are slightly better...... acceptors than formaldehyde molecules, while propyl radicals are as good as H2O. The hydrogen bond strength appears to depend on the proton affinity of the proton donor and on the ionization energy of the acceptor alkyl radical, not on the donor-acceptor proton affinity difference, reflecting...

Incontinence and Erectile Dysfunction Following Radical Prostatectomy: A Review

Directory of Open Access Journals (Sweden)

Gerasimos Alivizatos

2005-01-01

Full Text Available Radical prostatectomy remains the treatment of choice for localized prostate cancer in age-appropriate and health-appropriate men. Although cancer control is the most important aspect of a radical prostatectomy, minimization of postoperative morbidity, especially urinary incontinence and erectile dysfunction, is becoming a greater concern. We reviewed recent data available on Medline regarding the incidence, pathophysiology, evaluation, and treatment of incontinence and sexual dysfunction after radical prostatectomy. Health-related quality of life issues have been specifically addressed. Although low incidences of incontinence and erectile dysfunction after radical prostatectomy have been reported in the hands of experienced surgeons, the literature review revealed a great variety, with incontinence rates ranging from 0.3–65.6% and potency rates ranging from 11–87%. Several factors contribute to this wide difference, the most important being the application of a meticulous surgical technique. General and cancer-specific health-related quality of life is not being affected after radical prostatectomy. The incidence of incontinence and erectile dysfunction is higher after radical prostatectomy when compared to the incidence observed when other therapies for localized prostate cancer are applied. However, the majority of the patients undergoing radical prostatectomy would vote for the operation again. Today, avoidance of major complications after radical prostatectomy depends mostly on a high-quality surgical technique. When incontinence or erectile dysfunction persists after radical prostatectomy, the majority of the treated patients can be managed effectively by various methods.

Formation of radical cations of diaryloxadiazoles

International Nuclear Information System (INIS)

Helmstreit, W.

1988-01-01

The nature of the formation of the radical cation of the 2,5-bis-(p-diethylaminophenyl)-1,3,4-oxadiazole (PC) in liquid n-butyl chloride and acetonitrile has been investigated by observing excited state fluorescence and transient absorption using nanosecond pulse radiolysis and laser flash photolysis. The formation of solute oxonium ions has also been observed. At concentrations -4 mol dm -3 the growth time at which the transient absorption of the radical cation reaches the maximum follows the rise time of the electron pulse ( 2 laser yields the solute radical cation in an acetonitrile solution of 2 x 10 -4 mol dm -3 PC via an electronically excited state. Here, the generation time was smaller than 5 ns. The yield of the cation is increased by addition of CCl 4 . A reaction mechanism is proposed that explains the fast cation formation in terms of an exciplex formed by interaction between an electronically excited state of diaryloxadiazole and the ground state of the solvent. This exciplex yields the solute radical cation. (author)

Radical feminists & trans activists truce

OpenAIRE

Mackay, F.

2014-01-01

#GenderWeek: Truce! When radical feminists and trans feminists empathise\\ud Feminist Times\\ud By Finn Mackay \\ud read all #GenderWeek articles.\\ud We wanted to explore the ground between the polarised, entrenched positions in the so-called “TERF-war”. Radical feminists on one pole, trans-inclusionary feminists and trans activists on the other. The disputed territory being women-only space, language and the ever changing legal framework surrounding gender.\\ud Entrenchment leads to stalemate. S...

Leadership Styles for the Five Stages of Radical Change

Science.gov (United States)

1998-04-01

radical change. This article continues prior work on radical change with theory and research on leadership style. The result is a model of radical...every stage of that process. Leadership style and organiza- tional change theory and re- search have ex- isted for de- cades, but have rarely con...phase, inspire and en- ergize them to adopt the change after it Figure 3. Senior Manager Leadership Styles for the Five Phases of Radical Change Phase

Radical scavenging propensity of Cu2 +, Fe3 + complexes of flavonoids and in-vivo radical scavenging by Fe3 +-primuletin

Science.gov (United States)

Jabeen, Erum; Janjua, Naveed Kausar; Ahmed, Safeer; Murtaza, Iram; Ali, Tahir; Hameed, Shahid

2017-01-01

Cu2 + and Fe3 + complexes of three flavonoids (morin or mo, quercetin or quer and primuletin or prim) were synthesized with the objective of improving antioxidant capacities of flavonoids. The radical scavenging activities of pure flavonoids and their metal complexes were assayed to monitor their tendencies towards sequestering of radicals at physiological conditions. The scavenger potencies of metal-flavonoid complexes were significantly higher than those of the parent flavonoids. Further, influence of the solvent polarity on the radical capturing by flavonoids and their metal complexes was in favor for the polar solvent. Fe3 +-prim displayed its radical scavenging ability via up gradation of CAT and SOD activities in in-vivo antioxidant assays.

Muon substituted free radicals

International Nuclear Information System (INIS)

Burkhard, P.; Fischer, H.; Roduner, E.; Strub, W.; Gygax, F.N.; Brinkman, G.A.; Louwrier, P.W.F.; McKenna, D.; Ramos, M.; Webster, B.C.

1984-01-01

Spin polarized energetic positive muons are injected as magnetic probes into unsaturated organic liquids. They are implemented via fast chemical processes ( -10 s) in various molecules. Of particular interest among these are muonium substituted free radicals. The technique allows determination of accurate rate coefficients for fast chemical reactions of radicals. Furthermore, radiochemical processes occuring in picoseconds after injection of the muon are studied. Of fundamental interest are also the structural and dynamical implications of substituting a proton by a muon, or in other terms, a hydrogen atom by a muonium atom. Selected examples for each of these three types of experiments are given. (Auth.)

Fast beam studies of free radical photodissociation

Energy Technology Data Exchange (ETDEWEB)

Neumark, D.M. [Lawrence Berkeley Laboratory, CA (United States)

1993-12-01

The authors have developed a novel technique for studying the photodissociation spectroscopy and dynamics of free radicals. In these experiments, radicals are generated by laser photodetachment of a fast (6-8 keV) mass-selected negative ion beam. The resulting radicals are photodissociated with a second laser, and the photofragments are collected and detected with high efficiency using a microchannel plate detector. The overall process is: ABC{sup -} {yields} ABC + e{sup -} {yields} A + BC, AB + C. Two types of fragment detection schemes are used. To map out the photodissociation cross-section of the radical, the photodissociation laser is scanned and the total photofragment yield is measured as a function of wavelength. In other experiments, the photodissociation frequency is fixed and the photofragment masses, kinetic energy release, and scattering angle is determined for each photodissociation event.

Total free radical species and oxidation equivalent in polluted air.

Science.gov (United States)

Wang, Guoying; Jia, Shiming; Niu, Xiuli; Tian, Haoqi; Liu, Yanrong; Chen, Xuefu; Li, Lan; Zhang, Yuanhang; Shi, Gaofeng

2017-12-31

Free radicals are the most important chemical intermediate or agent of the atmosphere and influenced by thousands of reactants. The free radicals determine the oxidizing power of the polluted air. Various gases present in smog or haze are oxidants and induce organ and cellular damage via generation of free radical species. At present, however, the high variability of total free radicals in polluted air has prevented the detection of possible trends or distributions in the concentration of those species. The total free radicals are a kind of contaminants with colorless, tasteless characteristics, and almost imperceptible by human body. Here we present total free radical detection and distribution characteristics, and analyze the effects of total free radicals in polluted air on human health. We find that the total free radical values can be described by not only a linear dependence on ozone at higher temperature period, but also a linear delay dependence on particulate matter at lower temperature period throughout the measurement period. The total free radical species distribution is decrease from west to east in Lanzhou, which closely related to the distribution of the air pollutants. The total free radical oxidation capacity in polluted air roughly matches the effects of tobacco smoke produced by the incomplete combustion of a controlled amount of tobacco in a smoke chamber. A relatively unsophisticated chromatographic fingerprint similarity is used for indicating preliminarily the effect of total free radicals in polluted air on human health. Copyright © 2017 Elsevier B.V. All rights reserved.

Reactions of inorganic free radicals with liver protecting drugs

International Nuclear Information System (INIS)

Gyoergy, I.; Foeldiak, G.; Blazovics, A.; Feher, J.

1990-01-01

Liver protecting drugs, silibinin, a flavonolignane, and the dihydroquinoline derivatives, CH 402 and MTDQ-DA, were shown to inhibit processes in which enzymatically or non-enzymatically generated free radicals were involved. Inorganic free radicals (N 3 , (SCN) 2 - , OH, Trp, CO 2 - , O 2 - ) produced by pulse radiolysis readily react with the compounds, which transform into exceptionally long-lived, unreactive transients. Time evolution of the UV and visible spectra indicate that oxidising radicals form a phenoxyl type radical from silibinin, while OH forms an adduct by attacking, simultaneously, at various sites of the molecule. Superoxide radicals reduce silibinin and oxidise CH 402 and MTDQ-DA. It is concluded that the drugs might exhibit antioxidant behavior in living systems. (author)

Radical Islamism and Failed Developmentalism

OpenAIRE

Rahnema, Saeed

2008-01-01

The rise of radical Islamism in recent years does not limit the applicability of the concept of cultural nationalism. Rather the two are intertwined in ways which this article will attempt to highlight. Islam took specific national forms as modern nation-states arose and the contemporary resurgence of radical Islamism also follows that modern pattern. I examine the emergence of the three most important movements in the Islamic world, namely, the Muslim Brotherhood in Egypt, Jama'at-e Islami i...

Robot-assisted radical cystoprostatectomy: Analysis of the complications and oncological and functional aspects.

Science.gov (United States)

Kanashiro, A; Gaya, J M; Palou, J; Gausa, L; Villavicencio, H

2017-05-01

To review our experience in robot-assisted radical cystectomy, assessing the complications and oncological and functional results. From 2007 to 2014, we performed 67 robot-assisted radical cystectomies combined with lymphadenectomy in 61 cases. The operations were performed on 37 patients due to muscle-invasive tumours and on 30 due to high-risk nonmuscle-invasive tumours. Urinary diversion was conducted extracorporeally, using a Studer neobladder in 47 cases. The mean blood loss was 300mL. No case required conversion to open surgery. The median number of lymph nodes extracted was 16 (range 3-33). Pathology revealed 16 pT0, 15 pTis,-pT1-pTa and 44 muscle-invasive tumours, 8 pN+ and 1 with positive margins. The mean hospital stay was 9 days. With a median follow-up of 16 months, 9 (13%) patients were readmitted after the discharge, most for infections associated with the vesical catheter and other catheters. Forty patients (59.7%) presented complications (most were Clavien grade 1-2). There was recurrence during the follow-up in 4 cases (6%), and 4 (5.9%) patients died from cancer. Nineteen (28.3%) patients had complications after 30 days, most of which were urinary tract infections. Of the 47 patients with a neobladder, 45 (96%) had proper daytime continence and 42 (89%) had proper nighttime continence. Ninety percent and 64% of the patients with previously normal sexual function and reduced sexual function, respectively, were able to preserve sexual function with or without drug treatment. Robot-assisted radical cystectomy plus lymphadenectomy, with extracorporeal reconstruction of the urinary diversion, offers good oncological and functional results without increasing the number of complications. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Hybrid radical energy storage device and method of making

Science.gov (United States)

Gennett, Thomas; Ginley, David S; Braunecker, Wade; Ban, Chunmei; Owczarczyk, Zbyslaw

2015-01-27

Hybrid radical energy storage devices, such as batteries or electrochemical devices, and methods of use and making are disclosed. Also described herein are electrodes and electrolytes useful in energy storage devices, for example, radical polymer cathode materials and electrolytes for use in organic radical batteries.

Repair Activity of trans-Resveratrol toward 2'-Deoxyguanosine Radicals.

Science.gov (United States)

Cheng, Xing; An, Ping; Li, Shujin; Zhou, Liping

2018-04-26

In the present study, the repair activity of trans-resveratrol toward 2'-deoxyguanosine (dGuo) radicals in polar and nonpolar solvents was studied using density functional theory. The hydrogen transfer/proton coupled electron transfer and single electron transfer (SET) mechanisms between trans-resveratrol and dGuo-radicals were considered. Taking into consideration the molar fraction of neutral trans-resveratrol (ROH) and anionic trans-resveratrol (RO - ), the overall rate constants for repairing dGuo-radicals by trans-resveratrol are 9.94 × 10 8 and 2.01 × 10 9 dm 3 mol -1 s -1 in polar and nonpolar solvents, respectively, and the overall rate constant of repairing cation radical (dGuo •+ ) by trans-resveratrol via an SET mechanism is 7.17 × 10 9 dm 3 mol -1 s -1 . The repair activity of RO - toward dGuo-radicals is better than that of ROH, but the repair activity of ROH toward dGuo •+ is better than that of RO - . Unfortunately, neither ROH nor RO - can repair the 2'-deoxyribose radicals of dGuo. It can therefore be concluded that trans-resveratrol is an effective antioxidant for repairing base radicals of dGuo and dGuo •+ . The study can help us understand the repair activity of trans-resveratrol toward dGuo radicals.

Reaction kinetics of resveratrol with thiyl and alkoxyl radicals

International Nuclear Information System (INIS)

Dzeba, I.; Mihaljevic, B.

2011-01-01

Complete text of publication follows. Plant derived resveratrol (trans-3,5,4'-trihydroxystilbene) possesses a broad spectrum of biological activities, one of them are very well known its antioxidative properties. Our work aims to provide kinetic data with regard to the reactivity of resveratrol with uninvestigated short-lived bioradicals, identified as mediators in oxidative lipid degradation processes. Radicals of our interest are alkoxyl radicals, well known propagators of the chain free radical reactions in lipids, and thiyl radicals which protect lipids from their degradation pathway, but at the same time cause the isomerization of the double bonds. In order to investigate these reactions of resveratrol laser flash photolysis was used. On the basis of competitive kinetics the rate constants were determined under pseudo-first order conditions in acetonitrile solutions at room temperature. Thiyl radicals were generated indirectly in solution containing 1-octadecanthiol and photosensitive benzophenone in acetonitrile using the light pulses at 347 nm from ruby laser. Tert-butoxyl radicals were generated directly by peroxide bond cleavage from di-tert-butyl peroxide in acetonitrile by light pulses of Nd:YAG at 355 nm, and ruby at 347 nm. Obtained rate constants for the reactions of resveratrol and radicals generated by laser flash photolysis will be summarized and compared with rare literature data for the rate constants of investigated reactions of resveratrol and other radicals generated by pulse radiolysis.

Free radicals created by radiation and aging symptoms

International Nuclear Information System (INIS)

Ashry, O.M.

2012-01-01

The universality of aging implies that its cause is basically the same in all species. A free radical hypothesis of aging has been proposed that the free radicals produced during normal metabolism of the cell over time damage DNA and other macromolecules leading to degenerative diseases, malignancies, and eventual death of vital cells which in turn causes aging and death of the organism. This hypothesis is supported by several observations. Radiation produces its biologic effect through free radical formation and causes premature aging. Second, the age pigment lipo fuscin is associated with lipid peroxidation. The hypothesis that oxygen radicals play a role in aging is also supported by the observation that, in general, long-lived species produce less endogenous free oxygen radicals because of their lower metabolic rate. Long-lived animals also have more superoxide dismutase than do their short-lived counterparts, and animal species with the longest lifespan have the highest levels of superoxide dismutase. Oxidative DNA damage is rapidly and effectively repaired. It has been estimated that there are several thousand oxidative DNA damage sites in a human cell every day, and the majority of these are repaired. However, a small fraction of unrepaired lesions could cause permanent changes in DNA and might be a major contributor to aging and cancer. A consequence of the free radical hypothesis of aging is the idea that free radical scavenging agents might be used to prevent aging. (author)

Portable exhausters POR-004 SKID B, POR-005 SKID C, POR-006 SKID D storage plan

International Nuclear Information System (INIS)

Nelson, O.D.; Keller, G.M.

1997-01-01

This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage

Multiple free-radical scavenging (MULTIS) capacity in cattle serum.

Science.gov (United States)

Sueishi, Yoshimi; Kamogawa, Erisa; Kimura, Anna; Kitahara, Go; Satoh, Hiroyuki; Asanuma, Taketoshi; Oowada, Shigeru

2017-01-01

Multiple free-radical scavenging (MULTIS) activity in cattle and human sera was evaluated with electron spin resonance spectroscopy. Scavenging rates against six active species, namely hydroxyl radical, superoxide anion, alkoxyl radical, alkylperoxyl radical, methyl radical, and singlet oxygen were quantified. The difference in the electron spin resonance signal intensity in the presence and absence of the serum was converted into the scavenging rates. Comparative MULTIS measurements were made in sera from eight beef cattle, three fetal calves and fifteen healthy human volunteers. Further, we determined the MULTIS value of albumin, the most abundant component in serum. MULTIS values in cattle sera indicated higher scavenging activity against most free radical species tested than human sera. In particular, cattle serum scavenging activities against superoxide and methyl radical were higher than human serum by 2.6 and 3.7 fold, respectively. In cattle serum, albumin appears to play a dominant role in MULTIS activity, but in human serum that is not the case. Previous data indicated that the abundance of uric acid in bovine blood is nearly 80% less than humans; however, this difference does not explain the deviation in MULTIS profile.

Aerosol Fragmentation Driven by Coupling of Acid-Base and Free-Radical Chemistry in the Heterogeneous Oxidation of Aqueous Citric Acid by OH Radicals.

Science.gov (United States)

Liu, Matthew J; Wiegel, Aaron A; Wilson, Kevin R; Houle, Frances A

2017-08-10

A key uncertainty in the heterogeneous oxidation of carboxylic acids by hydroxyl radicals (OH) in aqueous-phase aerosol is how the free-radical reaction pathways might be altered by acid-base chemistry. In particular, if acid-base reactions occur concurrently with acyloxy radical formation and unimolecular decomposition of alkoxy radicals, there is a possibility that differences in reaction pathways impact the partitioning of organic carbon between the gas and aqueous phases. To examine these questions, a kinetic model is developed for the OH-initiated oxidation of citric acid aerosol at high relative humidity. The reaction scheme, containing both free-radical and acid-base elementary reaction steps with physically validated rate coefficients, accurately predicts the experimentally observed molecular composition, particle size, and average elemental composition of the aerosol upon oxidation. The difference between the two reaction channels centers on the reactivity of carboxylic acid groups. Free-radical reactions mainly add functional groups to the carbon skeleton of neutral citric acid, because carboxylic acid moieties deactivate the unimolecular fragmentation of alkoxy radicals. In contrast, the conjugate carboxylate groups originating from acid-base equilibria activate both acyloxy radical formation and carbon-carbon bond scission of alkoxy radicals, leading to the formation of low molecular weight, highly oxidized products such as oxalic and mesoxalic acid. Subsequent hydration of carbonyl groups in the oxidized products increases the aerosol hygroscopicity and accelerates the substantial water uptake and volume growth that accompany oxidation. These results frame the oxidative lifecycle of atmospheric aerosol: it is governed by feedbacks between reactions that first increase the particle oxidation state, then eventually promote water uptake and acid-base chemistry. When coupled to free-radical reactions, acid-base channels lead to formation of low molecular

Timectomia estendida por cirurgia torácica videoassistida e cervicotomia no tratamento da miastenia Extended thymectomy through video assisted thoracic surgery and cervicotomy in the treatment of myasthenia

Directory of Open Access Journals (Sweden)

Eduardo Haruo Saito

2003-10-01

Full Text Available INTRODUÇÃO: A relação entre a miastenia e o timo é evidente e o tratamento atual desta condição inclui a timectomia. No entanto, uma revisão de nossa experiência com a timectomia revelou a necessidade do uso de uma técnica mais radical. OBJETIVO: Analisar retrospectivamente pacientes portadores de miastenia gravis que foram submetidos a timectomia radical por videotoracoscopia, ressaltando vantagens do método, complicações, análise histopatológica e resultados em relação ao controle da doença. MATERIAL E MÉTODO: Vinte e um pacientes miastênicos (18 do sexo feminino e três do sexo masculino, com idade variando de 17 a 51 anos foram submetidos a timectomia por videotoracoscopia bilateral associada a cervicotomia transversa com ressecção da glândula tímica, dos tecidos peritímicos e das gorduras pericárdicas direita e esquerda. Todos os tecidos implicados foram analisados pela anatomia patológica separadamente. Houve acompanhamento por período médio de 39,2 meses. RESULTADOS: Não houve mortalidade operatória. Ocorreram duas (9,5% lesões vasculares e um (4,8% paciente passou a apresentar disfonia leve permanente. Dezenove (90,4% pacientes estão com boa evolução, sem medicação ou com dose reduzida da mesma. A histopatologia demonstrou 10 hiperplasias do timo, seis involuções tímicas e cinco timos normais. A presença de tecido tímico ectópico foi detectada em seis (28,6% pacientes. CONCLUSÃO: A timectomia radical por videotoracoscopia ofereceu bom controle da miastenia gravis. Fez-se ressecção de tecido tímico ectópico em alguns pacientes.BACKGROUND: The relationship between myasthenia and the thymus is evident and the current treatment of this condition includes thymectomy. However, a revision of our experience with thymectomy has revealed the necessity of a more radical technique. OBJECTIVE: To analyze, retrospectively, myasthenia gravis patients who underwent videothoracoscopic radical thymectomy

Photoionization of the OH radical

International Nuclear Information System (INIS)

Dehmer, P.M.

1985-01-01

The hydroxyl radical (OH) is one of the most thoroughly studied free radicals because of its importance in atmospheric chemistry, combustion processes, and the interstellar medium. Detailed experimental and theoretical studies have been performed on the ground electronic state (X 2 PI/sub i/) and on the four lowest bound excited electronic states (A 2 Σ + , B 2 Σ + , D 2 Σ - , and C 2 Σ + ). However, because it is difficult to distinguish the spectrum of OH from the spectra of the various radical precursors, the absorption spectrum in the wavelength region below 1200 A has not been well characterized. In the present work, the spectrum of OH has been determined in the wavelength region from 750 to 950 A using the technique of photoionization mass spectrometry. This technique allows complete separation of the spectrum of OH from that of the other components of the discharge and permits the unambiguous determination of the spectrum of OH

Mechanisms of free radical-induced damage to DNA.

Science.gov (United States)

Dizdaroglu, Miral; Jaruga, Pawel

2012-04-01

Endogenous and exogenous sources cause free radical-induced DNA damage in living organisms by a variety of mechanisms. The highly reactive hydroxyl radical reacts with the heterocyclic DNA bases and the sugar moiety near or at diffusion-controlled rates. Hydrated electron and H atom also add to the heterocyclic bases. These reactions lead to adduct radicals, further reactions of which yield numerous products. These include DNA base and sugar products, single- and double-strand breaks, 8,5'-cyclopurine-2'-deoxynucleosides, tandem lesions, clustered sites and DNA-protein cross-links. Reaction conditions and the presence or absence of oxygen profoundly affect the types and yields of the products. There is mounting evidence for an important role of free radical-induced DNA damage in the etiology of numerous diseases including cancer. Further understanding of mechanisms of free radical-induced DNA damage, and cellular repair and biological consequences of DNA damage products will be of outmost importance for disease prevention and treatment.

Cenário da implantação de gestão por competências no Brasil.

Directory of Open Access Journals (Sweden)

Alanna Garcia

2013-09-01

Full Text Available Este estudo trata gestão por competências como uma inovação em modelo de gestão, justificando através de revisão teórica tal concepção, e busca identificar como o modelo está sendo implementado no Brasil. Foi feito um levantamento dos estudos realizados com a temática de análise da implementação do modelo de 2000 a 2011 nos periódicos classificados como de nível superior pela Qualis/CAPES. As análises possibilitaram concluir que só foi possível considerar a implantação do modelo como uma inovação radical em modelo de gestão quando a gestão por competências foi implementada com rigor conceitual e metodológico, obtendo os resultados esperados.

Acyclic diastereoselection in prochiral radical addition to prochiral olefins.

Science.gov (United States)

Sibi, Mukund P; Rheault, Tara R; Chandramouli, Sithamalli V; Jasperse, Craig P

2002-03-27

The stereochemical preference (syn or anti) when prochiral radicals add to prochiral acceptors is of fundamental interest. The primary focus of this research was to determine which factors influence the relative stereochemistry between the beta and gamma chiral centers when these are formed concurrently. While moderate diastereoselectivity was found for addition of alkyl (6a-d) and alpha-alkoxy radicals (16a-c) (15:1 anti). Steric influence in alkyl radical additions was difficult to evaluate due to decreased reactivity when using bulky reaction partners; however, more reactive alpha-alkoxy radicals, it was found that increasing steric bulk leads to moderate increases in selectivity. In addition, higher selectivity was observed when employing lanthanide Lewis acids whose environment (reactivity) was modified using achiral additives, suggesting a potentially simple means for selectivity enhancements in radical reactions. Overall these results indicate that significant stereoelectronic effects are necessary to achieve high levels of selectivity in prochiral radical additions to prochiral acceptors.

El decadentismo en la derecha radical contemporánea

Directory of Open Access Journals (Sweden)

Miguel Ángel Simón Gómez

2007-07-01

Full Text Available The main concern this articles deals with is, first, the elusive conceptual definition of the «radical right». In the last years a, so called, new consensus, has been developed in the literature of this field. The core of this new consensus about the radical right is the palingentic form of nationalism, form this pant of view the decadentism and the claim for a social renewal is a central point in the political thought of the radical right. In this article we deal with the decadent subjects of the radical right, pointing mainly to the apocalyptic tone of some major contributors of the radical right in the interwar France and Germany. In the second part we analyze the role of decadentism in the cotemporary work of some relevant authors of the European radical right, Alain de Benoist and Julius Evola. Finally we translate their idea of decadence of Europe to the political arena as shown the discourses of some right extremist European parties.

Tin-free enantioselective radical reactions using silanes.

Science.gov (United States)

Sibi, Mukund P; Yang, Yong-Hua; Lee, Sunggi

2008-12-04

Readily available hexyl silane is an excellent choice as a H-atom donor and a chain carrier in Lewis acid mediated enantioselective radical reactions. Conjugate radical additions to alpha,beta-unsaturated imides at room temperature proceed in good yields and excellent enantioselectivities.

Oncological outcomes of laparoscopic radical nephrectomy for renal cancer Resultados oncológicos da nefrectomia radical laparoscópica no tratamento do carcinoma renal

Directory of Open Access Journals (Sweden)

Jose R. Colombo Jr.

2007-01-01

Full Text Available PURPOSE: To report the 5-year oncological outcomes of patients undergoing laparoscopic radical nephrectomy for renal cancer compared to a cohort of patients undergoing open radical nephrectomy. METHODS: We retrospectively analyzed the data of 88 patients undergoing radical nephrectomy for renal cell carcinoma prior to January 2000. Of these, 45 patients underwent laparoscopic radical nephrectomy, and 43 patients underwent open radical nephrectomy. Inclusion criteria comprised clinically organ-confined tumors of 15 cm or less in size without concomitant lymphadenopathy or vena cava thrombus. Oncological follow-up data were obtained from charts, radiological reports, and phone calls to patients or their families, and were calculated from the date of surgery to the date of last appointment with physician or date of death. RESULTS: All laparoscopic procedures were completed without open conversion. On comparing the laparoscopic radical nephrectomy and open radical nephrectomy groups, mean tumor size was 5. 8 vs 6.2 cm (P = . 44, mean blood loss was 183 vs 461 mL (P = . 004, and mean operative time was 2.8 vs 3.7 hrs (P OBJETIVO: Relatar os resultados oncológicos após 5 anos de seguimento em pacientes submetidos a nefrectomia radical laparoscópica para tratamento do câncer renal, comparando esses com os resultados obtidos com um grupo de pacientes submetidos a nefrectomia radical aberta. MÉTODOS: Foram analisadas retrospectivamente as informações obtidas de 88 pacientes submetidos a nefrectomia radical para o tratamento do carcinoma renal realizadas previamente a Janeiro de 2000. Destes pacientes, 45 foram tratados com nefrectomia radical laparoscópica e 43 com nefrectomia radical aberta. Foram incluídos pacientes com tumores localizados com tamanho máximo de 15 cm, sem adenopatia ou sinal de envolvimento de veia renal na avaliação radiologica pré-operatória. As informações sobre o seguimento dos pacientes foram obtidas a partir de

Psychopathology according to behaviorism: a radical restatement.

Science.gov (United States)

Pérez-Alvarez, Marino

2004-11-01

This article is a radical restatement of the predominant psychopathology, which is characterized by nosological systems and by its approach towards a neurobiological conception of the so-called mental disorders. The "radical" sense of this restatement is that of radical behaviorism itself. As readers will recall, "radical" applied to behaviorism means total (not ignoring anything that interests psychology), pragmatic (referring to the practical sense of knowledge), and it also derives from the Latin word for "root" (and thus implies change beginning at a system's roots or getting to the root of things, in this case, of psychological disorders). Based on this, I introduce the Aristotelian distinction of material and form, which, besides being behaviorist avant la lettre, is used here as a critical instrument to unmask the hoax of psychopathology as it is presented. The implications of this restatement are discussed, some of them already prepared for clinical practice.

Hearing Status after Radical Mastoidectomy without Tympanoplasty.

Science.gov (United States)

Khan, Shamaila Nawaz; Udaipurwala, Iqbal Hussain; Mehmood, Talat; Rahat, Zahid Mehmood

2017-12-01

To find out the impairment of hearing associated with radical mastoidectomy by measuring the quantitative difference in the functional hearing level before and after radical mastoidectomy operation without tympanoplasty. Cross-sectional comparative study. Department of Otorhinolaryngology and Head Neck Surgery, Bahawal Victoria Hospital, Bahawalpur and PNS Shifa Hospital, Karachi, from November 2009 to January 2013. Eighty-five patients, diagnosed clinically as chronic suppurative otitis media with extensive cholesteatoma having history of ear discharge and hearing impairment for more than 6 weeks duration and requiring radical mastoidectomy for treatment, were included in this study. Pure tone audiogram was done before and after radical mastoidectomy. Hearing impairment was compared in each patient before and after the operation. Among the 85 patients, 54 (63.5%) were males and 31 (36.5%) were females, with the age ranged between 18 to 63 years, mean age being 42.31 4.8 years. The mean increase in hearing loss after radical mastoidectomy in air conduction was 7.19 dB, bone conduction was 4.16 dB, and air-bone gap was 3.75 dB (0.001). The ear became dry and safe in 82 patients (96.5%) out of a total of 85, and only 3 patients required revision surgery at a second stage. Radical mastoidectomy has a least negligible effect on hearing status and one should not limit this technique due to the concern of aggravated hearing in patients with extensive cholesteatoma at the cost of dry and safe ears, which should be of prime importance.

Functionalized graphene quantum dots loaded with free radicals combined with liquid chromatography and tandem mass spectrometry to screen radical scavenging natural antioxidants from Licorice and Scutellariae.

Science.gov (United States)

Wang, Guoying; Niu, XiuLi; Shi, Gaofeng; Chen, Xuefu; Yao, Ruixing; Chen, Fuwen

2014-12-01

A novel screening method was developed for the detection and identification of radical scavenging natural antioxidants based on a free radical reaction combined with liquid chromatography with tandem mass spectrometry. Functionalized graphene quantum dots were prepared for loading free radicals in the complex screening system. The detection was performed with and without a preliminary exposure of the samples to specific free radicals on the functionalized graphene quantum dots, which can facilitate charge transfer between free radicals and antioxidants. The difference in chromatographic peak areas was used to identify potential antioxidants. This is a novel approach to simultaneously evaluate the antioxidant power of a component versus a free radical, and to identify it in a vegetal matrix. The structures of the antioxidants in the samples were identified using tandem mass spectrometry and comparison with standards. Fourteen compounds were found to possess potential antioxidant activity, and their free radical scavenging capacities were investigated. The order of scavenging capacity of 14 compounds was compared according to their free radical scavenging rate. 4',5,6,7-Tetrahydroxyflavone (radical scavenging rate: 0.05253 mL mg(-1) s(-1) ) showed the strongest capability for scavenging free radicals. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Unimolecular reaction dynamics of free radicals

International Nuclear Information System (INIS)

Terry A. Miller

2006-01-01

Free radical reactions are of crucial importance in combustion and in atmospheric chemistry. Reliable theoretical models for predicting the rates and products of these reactions are required for modeling combustion and atmospheric chemistry systems. Unimolecular reactions frequently play a crucial role in determining final products. The dissociations of vinyl, CH2= CH, and methoxy, CH3O, have low barriers, about 13,000 cm-1 and 8,000 cm-1, respectively. Since barriers of this magnitude are typical of free radicals these molecules should serve as benchmarks for this important class of reactions. To achieve this goal, a detailed understanding of the vinyl and methoxy radicals is required. Results for dissociation dynamics of vinyl and selectively deuterated vinyl radical are reported. Significantly, H-atom scrambling is shown not to occur in this reaction. A large number of spectroscopic experiments for CH3O and CHD2O have been performed. Spectra recorded include laser induced fluorescence (LIF), laser excited dispersed fluorescence (LEDF), fluorescence dip infrared (FDIR) and stimulated emission pumping (SEP). Such results are critical for implementing dynamics experiments involving the dissociation of methoxy

Neuroprotection by Radical Avoidance: Search for Suitable Agents

Directory of Open Access Journals (Sweden)

Rüdiger Hardeland

2009-12-01

Full Text Available Neurodegeneration is frequently associated with damage by free radicals. However, increases in reactive oxygen and nitrogen species, which may ultimately lead to neuronal cell death, do not necessarily reflect its primary cause, but can be a consequence of otherwise induced cellular dysfunction. Detrimental processes which promote free radical formation are initiated, e.g., by disturbances in calcium homeostasis, mitochondrial malfunction, and an age-related decline in the circadian oscillator system. Free radicals generated at high rates under pathophysiological conditions are insufficiently detoxified by scavengers. Interventions at the primary causes of dysfunction, which avoid secondary rises in radical formation, may be more efficient. The aim of such approaches should be to prevent calcium overload, to reduce mitochondrial electron dissipation, to support electron transport capacity, and to avoid circadian perturbations. l-Theanine and several amphiphilic nitrones are capable of counteracting excitotoxicity and/or mitochondrial radical formation. Resveratrol seems to promote mitochondrial biogenesis. Mitochondrial effects of leptin include attenuation of electron leakage. Melatonin combines all the requirements mentioned, additionally regulates anti- and pro-oxidant enzymes and is, with few exceptions, very well tolerated. In this review, the perspectives, problems and limits of drugs are compared which may be suitable for reducing the formation of free radicals.

Analysis of radicals induced in irradiated foods

International Nuclear Information System (INIS)

Kishida, Keigo; Kaimori, Yoshihiko; Kawamura, Shoei; Sakamoto, Yuhki; Nakamura, Hideo; Ukai, Mitsuko; Kikuchi, Masahiro; Shimoyama, Yuhei; Kobayashi, Yasuhiko

2012-01-01

By electron spin resonance (ESR) spectroscopy, we revealed free radicals in γ-ray irradiated foods; black pepper, green coffee bean and ginseng. We also analyzed the decay behavior of radiation induced free radicals during storage of irradiated foods. The ESR spectrum of experimental irradiated foods consists of a sextet signal centered at g=2.0 and a singlet signal at the same g-value position and a singlet signal at g=4.0. The singlet signal at g=2.0 is originated from organic free radicals and its peak intensity showed the dependence of γ-ray irradiation dose levels. The signal intensity was decreased during storage. Only after 3 hours of radiation treatment the peak intensity was decreased fast and after that the intensity was decreased slowly. The relaxation times, T 1 and T 2 , of radiation induced free radicals showed the variations before and after irradiation. During long time storage period it was shown that T 1 was increased and T 2 was decreased. By analysis of decay process using the simulation methods based on the theory of reaction speed, it is considered that at least two kinds of radicals were induced in irradiated foods during long time storage. (author)

Electron spin resonance spectroscopy of organic radicals spectroscopy of organic radicals

CERN Document Server

Gerson, Fabian

2006-01-01

""This book should serve as a comprehensive one-volume source for finding what is known about the splitting constants and g factors of virtually all types of organic radicals."" Journal of the American Chemistry Society, 2004, Vol. 126 No. 20

Characterization of fatty acids, bioactive lipids, and radical scavenging activity of Canterbury bells seed oil

Directory of Open Access Journals (Sweden)

Hassanien, M. F.R.

2014-06-01

Full Text Available The aim of this study was to characterize the chemical composition and radical scavenging activity of Canterbury bells (Campanula medium seed oil. C. medium seeds contained 9.2% extractable oil. The lipid classes, fatty acids, phytosterol and tocopherol composition of C. medium seed oil were determined. The amount of neutral lipids in the oil was the highest, followed by glycolipids and phospholipids. Linoleic and oleic were the main fatty acids. C. medium oil is characterized by high levels of phytosterols and β-sitosterol was the main compound. β-Tocopherol constituted 42.5% of the total tocopherol content followed by γ-tocopherol. The radical scavenging activity (RSA toward 1,1-diphenyl-2-picrylhydrazyl (DPPH radicals and galvinoxyl radicals of C. medium oil were higher than those of extra virgin olive oil. The diverse potential uses of C. medium oil may make this plant industrially important.El objetivo de este estudio fue caracterizar la composición química y la actividad de captación de radicales de aceites de semillas de campanillas de Canterbury (Campanula medium. Las semillas de C. medium contenían 9,2 % de aceite extraíble. Se determinó la composición de las diferentes clases de lípidos, ácidos grasos, fitoesteroles y tocoferoles. La cantidad de lípidos neutros en el aceite fue mayoritario, seguido de glicolípidos y fosfolípidos. Linoleico y oleico fueron los ácidos grasos principales. El aceite de C. medium se caracteriza por altos niveles de fitoesteroles y β-sitosterol fue el compuesto principal. β-tocoferol constituía 42,5 % del contenido total de tocoferol seguido de γ-tocoferol. La actividad de captación de radicales (RSA a 1,1-difenil-2- picrilhidrazil (DPPH y radicales galvinoxil de C. medium fueron superiores a las de aceite de oliva virgen extra. Los diversos usos potenciales de los aceites de C. medium pueden hacer que esta planta pueda ser importante industrialmente.

Laparoscopically assisted vaginal radical trachelectomy

International Nuclear Information System (INIS)

Bielik, T.; Karovic, M.; Trska, R.

2013-01-01

Purpose: Radical trachelectomy is a fertility-sparing procedure with the aim to provide adequate oncological safety to patients with cervical cancer while preserving their fertility. The purpose of this study was to retrospectively evaluate, in a series of 3 patients, the feasibility, morbidity, and safety of laparoscopically assisted vaginal radical trachelectomy for early cervical cancer. Patients and Methods: Three non consecutive patients with FIGO stage IA1 and IB1 cervical cancer was evaluated in a period of years 2008 - 2011. The patients underwent a laparoscopic pelvic lymphadenectomy and radical parametrectomy class II procedure according to the Piver classification. The section of vaginal cuff, trachelectomy, permanent cerclage and isthmo-vaginal anastomosis ware realised by vaginal approach. Results: The median operative time, the median blood loss and the mean number of resected pelvic nodes was comparable with published data. Major intraoperative complications did not occur and no patient required a blood transfusion. The median follow-up time was 33 (38-59) months. One vaginal recurrence occurred in 7 months after primary surgery. The patient was underwent a radicalisation procedure and adjuvant oncologic therapy and now is free of disease. Conclusions: Laparoscopically assisted vaginal radical trachelectomy (LAVRT)may be an alternative in fertility-preserving surgery for early cervical cancer. The procedure offers patients potential benefits of minimally invasive surgery with adequate oncological safety, but it should be reserved for oncologic surgeons trained in advanced laparoscopic procedures. (author)

Gamma-sterilization-induced radicals in biodegradable drug delivery systems

International Nuclear Information System (INIS)

Maeder, K.; Swartz, H.M.; Domb, A.

1996-01-01

Electron paramagnetic resonance (EPR) spectroscopy (1.2 and 9.25 GHz, 25 o C) was used to characterize free radicals in gamma-ray sterilized biodegradable polymers of the type which are in clinical use. Free radicals were detected in all irradiated polymer samples. The temperature of irradiation (25 o vs dry ice temperature) had only a minor influence on the yield of radicals and the shape of the EPR spectra. In contrast, the composition of the polymers and the drugs incorporated in them did strongly influence the amount of radiation-induced free radicals and their reactivity. In general, polymers with high melting points and crystallinity had the highest yields of radicals observable at room temperature. We were able to use the free radicals induced by the usual sterilization procedures to follow the penetration of water and the degradation of the polymers in vitro and in vivo. The ability of in vivo EPR to follow drug delivery noninvasively and continuously in vivo, using the free radicals induced in the usual sterilization process indicates that this approach could be applied immediately for the characterization of these drug delivery systems in experimental animals and in the near future should be able to be used in human subjects. (author)

Moment matrices, border bases and radical computation

NARCIS (Netherlands)

B. Mourrain; J.B. Lasserre; M. Laurent (Monique); P. Rostalski; P. Trebuchet (Philippe)

2013-01-01

htmlabstractIn this paper, we describe new methods to compute the radical (resp. real radical) of an ideal, assuming it complex (resp. real) variety is nte. The aim is to combine approaches for solving a system of polynomial equations with dual methods which involve moment matrices and

Moment matrices, border bases and radical computation

NARCIS (Netherlands)

B. Mourrain; J.B. Lasserre; M. Laurent (Monique); P. Rostalski; P. Trebuchet (Philippe)

2011-01-01

htmlabstractIn this paper, we describe new methods to compute the radical (resp. real radical) of an ideal, assuming it complex (resp. real) variety is nte. The aim is to combine approaches for solving a system of polynomial equations with dual methods which involve moment matrices and

Free Radical Scavenging and Cellular Antioxidant Properties of Astaxanthin.

Science.gov (United States)

Dose, Janina; Matsugo, Seiichi; Yokokawa, Haruka; Koshida, Yutaro; Okazaki, Shigetoshi; Seidel, Ulrike; Eggersdorfer, Manfred; Rimbach, Gerald; Esatbeyoglu, Tuba

2016-01-14

Astaxanthin is a coloring agent which is used as a feed additive in aquaculture nutrition. Recently, potential health benefits of astaxanthin have been discussed which may be partly related to its free radical scavenging and antioxidant properties. Our electron spin resonance (ESR) and spin trapping data suggest that synthetic astaxanthin is a potent free radical scavenger in terms of diphenylpicryl-hydrazyl (DPPH) and galvinoxyl free radicals. Furthermore, astaxanthin dose-dependently quenched singlet oxygen as determined by photon counting. In addition to free radical scavenging and singlet oxygen quenching properties, astaxanthin induced the antioxidant enzyme paroxoanase-1, enhanced glutathione concentrations and prevented lipid peroxidation in cultured hepatocytes. Present results suggest that, beyond its coloring properties, synthetic astaxanthin exhibits free radical scavenging, singlet oxygen quenching, and antioxidant activities which could probably positively affect animal and human health.

Reaction kinetics of resveratrol with tert-butoxyl radicals

International Nuclear Information System (INIS)

Džeba, Iva; Pedzinski, Tomasz; Mihaljević, Branka

2012-01-01

The rate constant for the reaction of t-butoxyl radicals with resveratrol was studied under pseudo-first order conditions. The rate constant was determined by measuring the phenoxyl radical formation rate at 390 nm as function of resveratrol concentration in acetonitrile. The rate constant was determined to be 6.5×10 8 M −1 s −1 . This high value indicates the high reactivity consistent with the strong antioxidant activity of resveratrol. - Highlights: ► tert-butoxyl radicals were generated directly using laser flash photolysis. ► Rate constant was determined by the phenoxyl radical formation rate in acetonitrile. ► Rate constant was determined to be 6.5×10 8 M −1 s −1 .

Photoisomerization and photodissociation dynamics of reactive free radicals

Energy Technology Data Exchange (ETDEWEB)

Bise, Ryan T. [Univ. of California, Berkeley, CA (United States)

2000-08-01

The photofragmentation pathways of chemically reactive free radicals have been examined using the technique of fast beam photofragment translational spectroscopy. Measurements of the photodissociation cross-sections, product branching ratios, product state energy distributions, and angular distributions provide insight into the excited state potential energy surfaces and nonadiabatic processes involved in the dissociation mechanisms. Photodissociation spectroscopy and dynamics of the predissociative $\\tilde{A}$²A₁ and $\\tilde{B}$²A₂ states of CH₃S have been investigated. At all photon energies, CH₃ + S(³P_j), was the main reaction channel. The translational energy distributions reveal resolved structure corresponding to vibrational excitation of the CH₃ umbrella mode and the S(³P_j) fine-structure distribution from which the nature of the coupled repulsive surfaces is inferred. Dissociation rates are deduced from the photofragment angular distributions, which depend intimately on the degree of vibrational excitation in the C-S stretch. Nitrogen combustion radicals, NCN, CNN and HNCN have also been studied. For all three radicals, the elimination of molecular nitrogen is the primary reaction channel. Excitation to linear excited triplet and singlet electronic states of the NCN radical generates resolved vibrational structure of the N₂ photofragment. The relatively low fragment rotational excitation suggests dissociation via a symmetric C_2V transition state. Resolved vibrational structure of the N₂ photofragment is also observed in the photodissociation of the HNCN radical. The fragment vibrational and rotational distributions broaden with increased excitation energy. Simple dissociation models suggest that the HNCN radical isomerizes to a cyclic intermediate (c-HCNN) which then dissociates via a tight cyclic

Pronunciamiento de la Academia Nacional de Medicina sobre ‘Clonación Humana’

OpenAIRE

Perales Cabrera, Alberto

2013-01-01

Las cuestiones en debate: 1° ¿Cuándo comienza la vida humana? 2° ¿Es lícito crear embriones por clonación para implantarlos y crear nuevos seres humanos? ¿Puede considerarse la clonación como una forma alternativa de reproducción asistida? 3° ¿Es lícito crear embriones para destruirlos— y cultivar sus células con el propósito de curar enfermedades? 4° ¿Qué alternativas existen para la obtención de células troncales para terapia, sin usar clonación? 5° ¿Constituyen un problema único o problema...

Estudio de viabilidad comercial de los escamovisores LGS

OpenAIRE

López Devesa, Sergi

2013-01-01

Desde la invención del que se considera el primer automóvil de la historia en 1886 por Karl Benz, hasta la actualidad, la industria del automóvil no ha cesado de evolucionar a pasos ingentes. Tanto es así, que hoy día resulta complicado pensar en algún automóvil, ya no de gama alta, que no incorpore las últimas tecnologías, tales como; airbag, dirección asistida, ABS, ESP, GPS y un sinfín más de mejoras respecto a los automóviles que conducían nuestros antepasados. Con el objetivo de aport...

IMPLICACIONES BIOÉTICAS DERIVADAS DEL ACCESO DE LAS PAREJAS DEL MISMO SEXO A LAS TECNOLOGÍAS PROVENIENTES DE LA BIOMEDICINA Y LA BIOTECNOLOGÍA, PARA LA CONFORMACIÓN DE FAMILIAS HOMOPARENTALES

OpenAIRE

Zárate-Cuello, Amparo de Jesús; Celis, Luis Gustavo

2015-01-01

En este artículo se realiza una reflexión y una revisión, desde el ámbito de las ciencias básicas y del bioderecho, sobre los aspectos biológicos y genéticos de la homosexualidad, y sobre el impacto que tiene en la familia el acceso a las técnicas de reproducción asistida por parte de las parejas del mismo sexo. Lo anterior nos lleva al desarrollo de conceptos como la "violencia prenatal", el derecho de los niños a crecer en el seno de una familia con una imagen paterna y materna, al igual qu...

Uma análise behaviorista radical dos sonhos A radical behaviorist analysis of the dreams

Directory of Open Access Journals (Sweden)

Francynete Melo e Silva

2000-01-01

Full Text Available Embora não haja um consenso acerca de questões sobre o que são os sonhos, porque sonhamos, etc., a maioria dos estudos sobre a natureza dos sonhos concorda que ela está relacionada a condições internas do organismo. Contrariamente, o behaviorismo radical analisa os sonhos como comportamentos privados, sendo produtos das histórias filogenética, ontogenética e cultural. Neste sentido, este trabalho tem como objetivo analisar os sonhos a partir da perspectiva behaviorista radical, considerando-os como comportamentos perceptuais encobertos, argumentando-se que são aprendidos. Afirma-se que a interpretação dos sonhos é impossível se não se conhecem as contingências de reforço com as quais a pessoa está interagindo.In spite of the fact that there is no consensus concerning questions about the nature and origin of dreams, the majority of the studies on the nature of the dreams agrees that they are related to internal conditions of the organism. As opposed to that notion, the radical behaviorism analyses the dreams as private behaviors and, thus, as products of philogenetical, ontogenetical, and cultural histories. In this sense, this paper aims to analyze the dreams from a radical behaviorism perspective, considering them as private events, perceptual behaviors, and arguing that they are learned processes. It is asserted that the dreams interpretation is impossible if the contingencies that control such activity are unknown.

Microbial fuel cell as a free-radical scavenging tool

International Nuclear Information System (INIS)

Koleva, Ralitza; Yemendzhiev, Hyusein; Nenov, Valentin

2017-01-01

Microbial fuel cells (MFCs) are known for their capability to directly convert organic substrates into electricity by the biochemical activity of specific microorganisms. Availability of a proper terminal electron acceptor is crucial for this process. Free radicals, with their one or more unpaired electrons, are extremely reducible and could be considered as electron acceptors in terms of cathodic processes in MFC. During this reduction, free radicals could be transformed in the same manner as they are transformed by antioxidants. The present study investigated this opportunity by utilization of 2,2-diphenyl-1-picrylhydrazyl (150 mmol/dm"3 methanol solution) as a free-radical molecule. During the studied process, over 90% radical neutralization was observed in less than 16 hours. The results obtained demonstrate for the first time the potential of MFC type bioelectrochemical systems to serve as a free-radical scavenging tool and to provide antioxidant and anti-radical activity. In this way, this study opens a completely new field of research and application of bio-electrochemical systems

Moment matrices, border bases and radical computation

NARCIS (Netherlands)

Lasserre, J.B.; Laurent, M.; Mourrain, B.; Rostalski, P.; Trébuchet, P.

2013-01-01

In this paper, we describe new methods to compute the radical (resp. real radical) of an ideal, assuming its complex (resp. real) variety is finite. The aim is to combine approaches for solving a system of polynomial equations with dual methods which involve moment matrices and semi-definite

Inhomogeneous ensembles of radical pairs in chemical compasses

Science.gov (United States)

Procopio, Maria; Ritz, Thorsten

2016-11-01

The biophysical basis for the ability of animals to detect the geomagnetic field and to use it for finding directions remains a mystery of sensory biology. One much debated hypothesis suggests that an ensemble of specialized light-induced radical pair reactions can provide the primary signal for a magnetic compass sensor. The question arises what features of such a radical pair ensemble could be optimized by evolution so as to improve the detection of the direction of weak magnetic fields. Here, we focus on the overlooked aspect of the noise arising from inhomogeneity of copies of biomolecules in a realistic biological environment. Such inhomogeneity leads to variations of the radical pair parameters, thereby deteriorating the signal arising from an ensemble and providing a source of noise. We investigate the effect of variations in hyperfine interactions between different copies of simple radical pairs on the directional response of a compass system. We find that the choice of radical pair parameters greatly influences how strongly the directional response of an ensemble is affected by inhomogeneity.

Loading of free radicals on the functional graphene combined with liquid chromatography-tandem mass spectrometry screening method for the detection of radical-scavenging natural antioxidants.

Science.gov (United States)

Wang, Guoying; Shi, Gaofeng; Chen, Xuefu; Chen, Fuwen; Yao, Ruixing; Wang, Zhenju

2013-11-13

A novel free radical reaction combined with liquid chromatography electrospray ionization tandem mass spectrometry (FRR-LC-PDA-ESI/APCI-MS/MS) screening method was developed for the detection and identification of radical-scavenging natural antioxidants. Functionalized graphene was prepared by chemical method for loading free radicals (superoxide radical, peroxyl radical and PAHs free radical). Separation was performed with and without a preliminary exposure of the sample to specific free radicals on the functionalized graphene, which can facilitate reaction kinetics (charge transfers) between free radicals and potential antioxidants. The difference in chromatographic peak areas is used to identify potential antioxidants. The structure of the antioxidants in one sample (Swertia chirayita) is identified using MS/MS and comparison with standards. Thirteen compounds were found to possess potential antioxidant activity, and their free radical-scavenging capacities were investigated. The thirteen compounds were identified as 1,3,5-trihydroxyxanthone-8-O-β-D-glucopyranoside (PD1), norswertianin (PD2), 1,3,5,8-tetrahydroxyxanthone (PD3), 3, 3', 4', 5, 8-penta hydroxyflavone-6-β-D-glucopyranosiduronic acid-6'-pentopyranose-7-O-glucopyranoside (PD4), 1,5,8-trihydroxy-3-methoxyxanthone (PD5), swertiamarin (PS1), 2-C-β-D-glucopyranosyl-1,3,7-trihydroxylxanthone (PS2), 1,3,7-trihydroxylxanthone-8-O-β-D-glucopyranoside (PL1), 1,3,8-trihydroxyl xanthone-5-O-β-D-glucopyranoside (PL2), 1,3,7-trihydroxy-8-methoxyxanthone (PL3), 1,2,3-trihydroxy-7,8-dimethoxyxanthone (PL4), 1,8-dihydroxy-2,6-dimethoxy xanthone (PL5) and 1,3,5,8-tetramethoxydecussatin (PL6). The reactivity and SC50 values of those compounds were investigated, respectively. PD4 showed the strongest capability for scavenging PAHs free radical; PL4 showed prominent scavenging capacities in the lipid peroxidation processes; it was found that all components in S. chirayita exhibited weak reactivity in the superoxide

Radical polarization in double switching of external magnetic field

International Nuclear Information System (INIS)

Lukzen, N.N.; Morozov, V.A.; Sagdeev, R.Z.

1999-01-01

Theoretical treatment of radical spin evolution under the action of double switching of external magnetic field is proposed. Account is taken of evolution of the radical spin state during laser pulse which generates paramagnetic particles. It is shown that the most effective beats in the nuclear magnetization of diamagnetic products of recombination occur upon the jump into zero magnetic field after laser pulse. The phase of observed beats bears information about the type of the initial radical polarization. The frequency of the beats is determined by radical hyperfine structure. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Crotylations of alpha-carbonyl radicals with crotylstannane.

Science.gov (United States)

Sibi, Mukund P; Miyabe, Hideto

2002-10-03

Electrophilic radicals undergo crotylation with crotylstannane with moderate to good efficiency. The reaction provides the syn isomer as the major product. The present methodology is complementary to Claisen protocols for the synthesis of gamma,delta-unsaturated carboxylic acid derivatives. Details of the new radical methodology are presented. [reaction: see text

Radical Behaviorism and Buddhism: Complementarities and Conflicts

Science.gov (United States)

Diller, James W.; Lattal, Kennon A.

2008-01-01

Comparisons have been made between Buddhism and the philosophy of science in general, but there have been only a few attempts to draw comparisons directly with the philosophy of radical behaviorism. The present review therefore considers heretofore unconsidered points of comparison between Buddhism and radical behaviorism in terms of their…

DPPH and oxygen free radicals as pro-oxidant of biomolecules.

Science.gov (United States)

Letelier, María Eugenia; Molina-Berríos, Alfredo; Cortés-Troncoso, Juan; Jara-Sandoval, José; Holst, Marianne; Palma, Karina; Montoya, Margarita; Miranda, Dante; González-Lira, Víctor

2008-03-01

Numerous investigations exist about the alterations that oxygen free radicals can provoke on biomolecules; these modifications can be prevented and/or reversed by different antioxidants agents. On the other hand, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), a stable nitrogen synthetic radical, is used to evaluate the antioxidant capacity of medicinal herbal products; however, the structural changes that this radical provoke on the herbal active principles are not clear yet. In this work, we compared the redox reactivity of oxygen free radicals and DPPH radical on phospholipids and protein thiol groups present in rat liver microsomes. Cu2+/ascorbate was used as generator system of oxygen free radical and as antioxidant, an extract of Buddleja globosa's leaves. Cu2+/ascorbate provoked microsomal lipid peroxidation, microsomal thiols oxidation and oxygen consumption; all of these phenomena were inhibited by B. globosa extract. On the other hand, DPPH was bleached in different extension by the herbal extract and phosphatidyl choline; beside, DPPH decreased microsomal thiols content, but this phenomenon were not prevented by the herbal extract. Furthermore, DPPH did not induce oxygen consumption and neither modified the oxygen consumption induced by Cu2+/ascorbate. Distinct redox mechanisms may explain the differences between the reactivity of DPPH and oxygen free radicals on biomolecules, which is discussed.

Lipid-derived free radical production in superantigen-induced interstitial pneumonia

Science.gov (United States)

Miyakawa, Hisako; Mason, Ronald P.; Jiang, JinJie; Kadiiska, Maria B.

2009-01-01

We studied the free radical generation involved in the development of interstitial pneumonia (IP) in an animal model of autoimmune disease. We observed an electron spin resonance (ESR) spectrum of α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN) radical adducts detected in the lipid extract of lungs in autoimmune-prone mice after intratracheal instillation of staphylococcal enterotoxin B. The POBN adducts detected by ESR were paralleled by infiltration of macrophages and neutrophils in the bronchoalveolar lavage fluid. To further investigate the mechanism of free radical generation, mice were pretreated with the macrophage toxicant gadolinium chloride, which significantly suppressed the radical generation. Free radical generation was also decreased by pretreatment with the xanthine oxidase (XO) inhibitor allopurinol, the iron chelator Desferal, and the inducible nitric oxide synthase (iNOS) inhibitor 1400W. Histopathologically, these drugs significantly reduced both the cell infiltration to alveolar septal walls and the synthesis of pulmonary collagen fibers. Experiments with NADPH oxidase knockout mice showed that NADPH oxidase did not contribute to lipid radical generation. These results suggest that lipid-derived carbon-centered free radical production is important in the manifestation of IP and that a macrophage toxicant, an XO inhibitor, an iron chelator, and an iNOS inhibitor protect against both radical generation and the manifestation of IP. PMID:19376221

Influence of Free Radicals on the Intrinsic MRI Relaxation Properties.

Science.gov (United States)

Tain, Rong-Wen; Scotti, Alessandro M; Li, Weiguo; Zhou, Xiaohong Joe; Cai, Kejia

2017-01-01

Free radicals are critical contributors in various conditions including normal aging, Alzheimer's disease, cancer, and diabetes. Currently there is no non-invasive approach to image tissue free radicals based on endogenous contrast due to their extremely short lifetimes and low in vivo concentrations. In this study we aim at characterizing the influence of free radicals on the MRI relaxation properties. Phantoms containing free radicals were created by treating egg white with various H 2 O 2 concentrations and scanned on a 9.4 T MRI scanner at room temperature. T 1 and T 2 relaxation maps were generated from data acquired with an inversion recovery sequence with varied inversion times and a multi-echo spin echo sequence with varied echo times (TEs), respectively. Results demonstrated that free radicals express a strong shortening effect on T 1 , which was proportional to the H 2 O 2 concentration, and a relatively small reduction in T 2 (free radicals was estimated to be in the pM range that is within the physiological range of in vivo free radical expression. In conclusion, the free radicals show a strong paramagnetic effect that may be utilized as an endogenous MRI contrast for its non-invasive in vivo imaging.

Radicals of DNA and DNA nucleotides generated by ionising radiation

International Nuclear Information System (INIS)

Przybytniak, G.

2004-01-01

A first stage of cell processes leading to DNA damage of initiated by radical reactions. In a model system such transformations were generated by ionising radiation which involves production of electron loss and electron gain centers of the substrate and radical formation. Using cryogenic ESR spectroscopy it was found that the DNA nucleotides, which convert to radical anions upon electron capture undergo the separation of unpaired spin and charge due to protonation. Circular and linear dichroism studies enabled to conclude that iron ions(III) induce strong changes in the DNA helical structure indicating their coordination with nitrogen bases. The repair of DNA radicals produced via radiolytic oxidation, i.e. the guanine radical cation and the allyl type radical of thymine, is possible at elevated temperatures due to the involvement of sulphydryl groups. The influence of the thiol charge is then limited

Free radical-scavenging delta-lactones from Boletus calopus.

Science.gov (United States)

Kim, Jin-Woo; Yoo, Ick-Dong; Kim, Won-Gon

2006-12-01

The methanol extracts from the fruiting body of the mushroom Boletus calopus showed free radical-scavenging activity. Bioactivity-guided fractionation of the methanol extracts led to a new hydroxylated calopin named calopin B, along with the known delta-lactones calopin and cyclocalopin A. The structure of the new calopin analogue was elucidated by spectroscopic methods. All compounds showed potent free radical-scavenging activity against superoxide, DPPH, and ABTS radicals with IC (50) values of 1.2 - 5.4 microg/mL.

MISCONCEPTIONS AND NON-SCIENTIFIC CONCEPTS ON FREE RADICALS

Directory of Open Access Journals (Sweden)

Rosiris Sindeaux de Alencar Pires de Oliveira

2016-11-01

Full Text Available INTRODUCTION: Misconceptions or alternative conceptions are defined as conceptions that are somewhat different from the scientifically accepted ones and are known to be highly resistant to changes. Free radicals are a widely publicized subject in the media due to their putative importance in human aging and health. Free radicals are a subject susceptible to misconceptions widely spread by the media supporting prejudicial advertising inducing antioxidant consumption. OBJECTIVES: Identify and categorized different free radicals misconceptions published in printed media. MATERIALS AND METHODS: Revista Veja (Digital Archive, the weekly magazine with the largest circulation in Brazil, was selected for this investigation. Period analyzed: from 01/01/2000 to 31/07/2014 with search terms Free radicals and antioxidants. Passages selected were classified as: Right Concept (RC, Wrong Concept (WC, Misconception (MC, Inadequate generalization (IG, Inductive [to misconceptions] Concept (IC, Inductive [to misconceptions] Information (II, and Not fit the inclusion criteria (NFIC. Each one of these categories were further subdivided. DISCUSSION AND RESULTS: 79 magazine articles, advertisements and information materials were found which led to 293 text passages. 56.3% were MC, 21.4% II, 8.8% IC, 5.4% IG, 3.4% RC, 2.7% WR, 2.0% NFIC. The most frequently subcategory in each category was: MC: x [something] combats free radicals (22.6%; II: x [substance] is antioxidant (54.0%; IC: x [something] increases free radicals production (34.6%; IG: antioxidant x [substance] combats cancer (56.3%; RC: too much vitamins and minerals is harmful to health (30.0%; WR: free radicals are formed during oxygen conversion to energy process (25.0%. CONCLUSION: Magazine analysis reveal non-scientific concepts (MC, II, IC and IG to be highly frequent, notably misconceptions. Moreover, non-scientific concepts together reach 91.8% of all concepts while right concepts respond for only 2

Formation and thermal transformations of radicals in γ-irradiated cellulose

International Nuclear Information System (INIS)

Ershov, B.G.; Isakova, O.V.

1984-01-01

The work is aimed at more detailed theoretical analysis of the structure of radicals in cellulose gamma-irradiated at 77 K, specification of the mechanism of their formation, as well as studying reactions of transformation of radicals in the case of temperature increase. It is established that in the case of cellulose gamma-irradiation radicals appear with the localization of an unpaired electron in 1 and 4 positions of the pyranose cycle the formation of which is accompanied by the disruption of the glycoside bound. Thermal transformations of these radicals are conditioned by their dehydration and occur with the formation of radicals of the allelow type

Carbonate radical anion-induced electron transfer in bovine serum albumin

Energy Technology Data Exchange (ETDEWEB)

Joshi, Ravi [Chemistry Group, Bhabha Atomic Research Centre, Mumbai 400 085 (India)]. E-mail: rjudrin@yahoo.com; Mukherjee, T. [Chemistry Group, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2006-07-15

Reaction of native and thermally denatured bovine serum albumin (BSA) with carbonate radical anion (CO{sub 3}{sup -} radical) has been studied using pulse radiolysis technique. Scavenging of CO{sub 3}{sup -} radical by native BSA and consequent electron transfer from tyrosine to tryptophan radical has been observed to occur with almost same rate constant (k{approx}1.7x10{sup 8} dm{sup 3} mol{sup -1} s{sup -1}) at pH 8.8. Effect of structural changes, due to thermal denaturation, on scavenging of CO{sub 3}{sup -} radical and the electron transfer process have been studied and discussed in this paper.

Competing with the radical right: Distances between the European radical right and other parties on typical radical right issues

NARCIS (Netherlands)

Immerzeel, T.; Lubbers, M.; Coffé, H.

2016-01-01

The popularity of European Radical Right Populist parties (RRPs) has led to investigations into the distances between RRPs' and other parties' stances regarding immigration. This article adds to this literature by investigating the distance between RRPs and the other parties on a wider variety of

Competing with the radical right. Distances between the European radical right and other parties on typical radical right issues

NARCIS (Netherlands)

Immerzeel, T.; Lubbers, M.; Coffe, H.R.

2015-01-01

The popularity of European Radical Right Populist parties (RRPs) has led to investigations into the distances between RRPs’ and other parties’ stances regarding immigration. This article adds to this literature by investigating the distance between RRPs and the other parties on a wider variety of

Von Glaserfeld`s Radical Constructivism: A Critical Review

Science.gov (United States)

Hardy, Michael D.

We explore Ernst von Glaserfelds radical constructivism, its criticisms, and our own thoughts on what it promises for the reform of science and mathematics teaching. Our investigation reveals that many criticisms of radical constructivism are unwarranted; nevertheless, in its current cognitivist form radical constructivism may be insufficient to empower teachers to overcome objectivist cultural traditions. Teachers need to be empowered with rich understandings of philosophies of science and mathematics that endorse relativist epistemologies; for without such they are unlikely to be prepared to reconstruct their pedagogical practices. More importantly, however, is a need for a powerful social epistemology to serve as a referent for regenerating the culture of science education. We recommend blending radical constructivism with Habermas theory of communicative action to provide science teachers with a moral imperative for adopting a constructivist epistemology.

Prospective study comparing laparoscopic and open radical cystectomy: Surgical and oncological results.

Science.gov (United States)

Esquinas, C; Alonso, J M; Mateo, E; Dotor, A; Martín, A M; Dorado, J F; Arance, I; Angulo, J C

2018-03-01

Laparoscopic radical cystectomy with lymphadenectomy and urinary diversion is an increasingly widespread operation. Studies are needed to support the oncological effectiveness and safety of this minimally invasive approach. A nonrandomised, comparative prospective study between open radical cystectomy (ORC) and laparoscopic radical cystectomy (LRC) was conducted in a university hospital. The main objective was to compare cancer-specific survival. The secondary objective was to compare the surgical results and complications according to the Clavien-Dindo scale. We treated 156 patients with high-grade invasive bladder cancer with either ORC (n=70) or LRC (n=86). The mean follow-up was 33.5±23.8 (range 12-96) months. The mean age was 66.9+9.4 years, and the male to female ratio was 19:1. Both groups were equivalent in age, stage, positive lymph nodes, in situ carcinoma, preoperative obstructive uropathy, adjuvant chemotherapy and type of urinary diversion. There were no differences between the groups in terms of cancer-specific survival (log-rank; P=.71). The histopathology stage was the only independent variable that predicted the prognosis. The hospital stay (P=.01) and operative transfusion rates (P=.002) were less for LRC. The duration of the surgery was greater for LRC (P<.001). There were no differences in the total complications rate (p=.62) or major complications (P=.69). The risk of evisceration (P=.02), surgical wound infection (P=.005) and pneumonia (P=.017) was greater for ORC. The risk of rectal lesion (P=.017) and urethrorectal fistulae (P=.065) was greater for LRC. LRC is an equivalent treatment to ORC in terms of oncological efficacy and is advantageous in terms of transfusion rates and hospital stays but not in terms of operating room time and overall safety. Studies are needed to better define the specific safety profile for each approach. Copyright © 2017 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Moderate and Radical Islam

National Research Council Canada - National Science Library

Rabasa, Angel

2005-01-01

This report presents the statement of Angel Rabasa, PhD, Senior Policy Analyst, The RAND Corporation, to the Committee on Armed Services, Defense Review Terrorism and Radical Islam Gap Panel, United...

Terapias y Actividades asistidas por animales: una buena herramienta en la Educación Infantil.

OpenAIRE

García Meneses, Berta

2015-01-01

Este es un trabajo fin de grado el cual presenta la posibilidad de realizar terapias y actividades de asistencia con animales, tanto para niños normales, como para niños con alguna dificultad, ayudándonos siempre de las asociaciones de la comunidad. This is a Final Grade Work, that I describing the possibility of the therapy and activities, for different children of the school, that present someone problems or not. This Final Grade Work, it´s help for many association of this community. ...

Auxiliares de movilidad en la discapacidad visual. Terapia asistida por perros: perros guía

OpenAIRE

García López, Verónica

2017-01-01

El desplazamiento y movilidad en personas con baja visión o ceguera no sería tan eficiente sin el uso de determinadas ayudas como pueden ser los auxiliares de desplazamiento, como el guía vidente, el bastón blanco y el perro guía. De todos ellos se hará una descripción general de los guías videntes, un análisis del bastón blanco sobre sus características, técnicas de uso y nuevas tecnologías aplicadas a este; también se comentará brevemente el uso del perro como perro de asistencia y una revi...

Anatomical landmarks of radical prostatecomy.

Science.gov (United States)

Stolzenburg, Jens-Uwe; Schwalenberg, Thilo; Horn, Lars-Christian; Neuhaus, Jochen; Constantinides, Costantinos; Liatsikos, Evangelos N

2007-03-01

In the present study, we review current literature and based on our experience, we present the anatomical landmarks of open and laparoscopic/endoscopic radical prostatectomy. A thorough literature search was performed with the Medline database on the anatomy and the nomenclature of the structures surrounding the prostate gland. The correct handling of puboprostatic ligaments, external urethral sphincter, prostatic fascias and neurovascular bundle is necessary for avoiding malfunction of the urogenital system after radical prostatectomy. When evaluating new prostatectomy techniques, we should always take into account both clinical and final oncological outcomes. The present review adds further knowledge to the existing "postprostatectomy anatomical hazard" debate. It emphasizes upon the role of the puboprostatic ligaments and the course of the external urethral sphincter for urinary continence. When performing an intrafascial nerve sparing prostatectomy most urologists tend to approach as close to the prostatic capsula as possible, even though there is no concurrence regarding the nomenclature of the surrounding fascias and the course of the actual neurovascular bundles. After completion of an intrafascial technique the specimen does not contain any periprostatic tissue and thus the detection of pT3a disease is not feasible. This especially becomes problematic if the tumour reaches the resection margin. Nerve sparing open and laparoscopic radical prostatectomy should aim in maintaining sexual function, recuperating early continence after surgery, without hindering the final oncological outcome to the procedure. Despite the different approaches for radical prostatectomy the key for better results is the understanding of the anatomy of the bladder neck and the urethra.

Habitat of in vivo transformation influences the levels of free radical scavengers in Clinostomum complanatum: implications for free radical scavenger based vaccines against trematode infections.

Science.gov (United States)

Zafar, Atif; Rizvi, Asim; Ahmad, Irshad; Ahmad, Masood

2014-01-01

Since free radical scavengers of parasite origin like glutathione-S-transferase and superoxide dismutase are being explored as prospective vaccine targets, availability of these molecules within the parasite infecting different hosts as well as different sites of infection is of considerable importance. Using Clinostomum complanatum, as a model helminth parasite, we analysed the effects of habitat of in vivo transformation on free radical scavengers of this trematode parasite. Using three different animal models for in vivo transformation and markedly different sites of infection, progenetic metacercaria of C. complanatum were transformed to adult ovigerous worms. Whole worm homogenates were used to estimate the levels of lipid peroxidation, a marker of oxidative stress and free radical scavengers. Site of in vivo transformation was found to drastically affect the levels of free radical scavengers in this model trematode parasite. It was observed that oxygen availability at the site of infection probably influences levels of free radical scavengers in trematode parasites. This is the first report showing that habitat of in vivo transformation affects levels of free radical scavengers in trematode parasites. Since free radical scavengers are prospective vaccine targets and parasite infection at ectopic sites is common, we propose that infections at different sites, may respond differently to free radical scavenger based vaccines.

Detection of free radicals by radical trapping and 15N NMR spectroscopy in copolymerization of methyl acrylate and styrene

NARCIS (Netherlands)

Kelemen, P.; Klumperman, B.

2003-01-01

The macroradicals taking part in the copolymn. of Me acrylate and styrene were trapped by reaction with a 15N labeled stable nitroxyl radical at 70 DegC. The nitroxyl radical is formed in situ from a thermally instable alkoxyamine precursor. 15N NMR spectroscopy is applied to detect the trapping

Donor free radical explosive composition

Science.gov (United States)

Walker, Franklin E. [15 Way Points Rd., Danville, CA 94526; Wasley, Richard J. [4290 Colgate Way, Livermore, CA 94550

1980-04-01

An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a donor additive comprising an organic compound or mixture of organic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and which is not an explosive, or an inorganic compound or mixture of inorganic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and selected from ammonium or alkali metal persulfates.

Airborne measurement of peroxy radicals in the lower troposphere

Science.gov (United States)

Andrés Hernández, Maria Dolores; Horstjann, Markus; Kartal, Deniz; Krebsbach, Marc; Linke, Christian; Lichtenstern, Michael; Andrey, Javier; Burrows, John P.

2013-04-01

The importance of peroxy radicals in the tropospheric chemistry is well recognized in the scientific literature. Hydroxy- and organic peroxy radicals (HO2 and RO2, R being an organic chain) are key intermediates in the OH radical initiated oxidation of CO and SO2, of volatile organic compounds (VOC), in the ozonolysis of alkenes and photo-oxidation of carbonyl species. Peroxy radicals are responsible for the ozone production in the troposphere, the formation of peroxides and other oxidants. Although radical chemistry in the troposphere has been subject of intensive research in the past three decades, it is still very few known about the vertical distribution of peroxy radicals. Airborne observations are scarce in spite of their particular importance to improve the understanding of the tropospheric chemistry and the oxidising capacity of the atmosphere at different altitudes. In situ trace gas measurements were carried out in summer 2010 on board of the INTA (Instituto Nacional de Técnicas Aeroespaciales) C212 aircraft over Spain in the frame of the EUFAR project VERDRILLT (VERtical Distribution of Radicals In the Lower Layers of the Troposphere), and in cooperation with the DLR (Deutsches Zentrum für Luft- und Raumfahrt), the University of Wuppertal, the CEAM (Centro de Estudios Ambientales del Mediterráneo) and the UPV-EHU University in Bilbao. VERDRILLT aimed at getting a deeper understanding of the vertical distribution of peroxy radicals in the lower layers of the troposphere. Measurements were taken over urban areas and extensions of different vegetation under meteorological conditions favouring active photochemistry and convection from the ground into close atmospheric layers. Results and main findings will be presented and discussed.

Free radicals in chemical carcinogenesis.

Science.gov (United States)

Clemens, M R

1991-12-15

During the past decade, remarkable progress has been made in our understanding of cancer-causing agents, mechanisms of cancer formation and the behavior of cancer cells. Cancer is characterized primarily by an increase in the number of abnormal cells derived from a given normal tissue, invasion of adjacent tissues by these abnormal cells, and lymphatic or blood-borne spread of malignant cells to regional lymph nodes and to distant sites (metastasis). It has been estimated that about 75-80% of all human cancers are environmentally induced, 30-40% of them by diet. Only a small minority, possibly no more than 2% of all cases, result purely from inherent genetic changes. Several lines of evidence confirm that the fundamental molecular event or events that cause a cell to become malignant occur at the level of the DNA and a variety of studies indicate that the critical molecular event in chemical carcinogenesis is the interaction of the chemical agent with DNA. The demonstration that DNA isolated from tumor cells can transfect normal cells and render them neoplastic provides direct proof that an alteration of the DNA is responsible for cancer. The transforming genes, or oncogenes, have been identified by restriction endonuclease mapping. One of the characteristics of tumor cells generated by transformation with viruses, chemicals, or radiation is their reduced requirement for serum growth factors. A critical significance of electrophilic metabolites of carcinogenes in chemical carcinogenesis has been demonstrated. A number of "proximate" and "ultimate" metabolites, especially those of aromatic amines, were described. The "ultimate" forms of carcinogens actually interact with cellular constituents to cause neoplastic transformation and are the final metabolic products in most pathways. Recent evidence indicates that free radical derivatives of chemical carcinogens may be produced both metabolically and nonenzymatically during their metabolism. Free radicals carry no

First examples of intramolecular addition of primary amidyl radicals to olefins

Energy Technology Data Exchange (ETDEWEB)

Gaudreault, P.; Drouin, C.; Lessard, J. [Sherbrooke Univ., PQ (Canada). Dept. de Chimie

2005-07-01

This paper presents the first examples of radical cyclization involving a primary amidyl radical and a pendant olefin. Amidyl radicals have attracted interest in terms of their structure, reactivity, and ways to generate them. The intramolecular addition of an amidyl radical on a pendant olefin appears to be a powerful synthetic tool for creating nitrogen-containing heterocycles. Although several examples of cyclization involving secondary amidyl radicals are cited in the the literature, there are no examples of a successful cyclization involving a primary amidyl radical. This is because all attempts to prepare the usual radical precursors have failed when applied to olefinic primary amides. This study reveals that N-(phenylthio) derivatives of olefinic primary amides can be easily prepared and that nitrogen heterocycles resulting from their radical cyclization can be obtained in good to very good yields. Four olefinic primary amides were chosen as models for radical cyclization of primary amidyl radicals. They were prepared from the corresponding carboxylic acids via the acid chlorides. Conversion of primary amides into suitable amidyl radical precursors was also examined. The study showed that N-(phenylthio) amides could be easily prepared by following a slightly modified protocol developed by Esker and Newcomb, by reacting the anion of the amide with phenylsulfenyl chloride. In particular, olefinic N-(phenylthio) amides were prepared and used as primary amidyl radical precursors in a reaction with a solution of 2,2'-azobis(isobutyronitrile) in catalytic quantities and tributyltin hydride in benzene. The resulting yields of cyclic products ranged from 63 to 85 per cent. The intent of the study was to demonstrate that it is no longer necessary to prepare an N-protected precursor and then remove the protecting group after cyclization. Further studies are currently underway. 10 refs., 1 tab.

Radical Documentaries, Neoliberal Crisis and Post-Democracy

Directory of Open Access Journals (Sweden)

Eugenia Siapera

2017-12-01

Full Text Available This article examines radical documentaries in Greece as a response to neoliberal crisis and post democracy. In a context where mainstream media have made themselves irrelevant, facing historical lows in trust and credibility, we found that radical documentaries have emerged outside the commodification of information and form part of the growing social or solidarity economy in Greece. Our analysis shows that these documentaries operate through a different political economy, that involves collaborative practices and that they are firmly oriented towards society rather than the political sphere. Overall, we found that radical documentaries are seeking to recuperate the media through engaging professional media workers, journalists, film directors, academics and actors; they operate through reclaiming media know-how; through radicalizing the financing, production and distribution by refusing to participate in commodification processes; and through recreating commonalities by thematizing the common, the public, and responsibility towards others.Their specific political role is found to be one of helping to restore the social body and to contribute to processes of commoning, whereby solidarity and social trust is recovered.

Evidence of radicals created by plasma in bacteria in water

International Nuclear Information System (INIS)

Lee, Chae Bok; Na, Young Ho; Hong, Tae-Eun; Choi, Eun Ha; Uhm, Han S.; Baik, Ku Youn; Kwon, Gichung

2014-01-01

Heavy water (D 2 O) was introduced into a non-thermal plasma-jet (NTPJ) device to generate deuterium monoxide (OD) radicals at room temperature. Owing to the similar reactivity and low prevalence of deuterium in nature, OD radicals can be utilized to visualize the OH radical interactions with water and living cells. Escherichia coli in water were treated with OD radicals, and D atom incorporation into cells was visualized using time-of-flight SIMS and Nano-SIMS. The results show that D atoms from NTPJ reach the cytoplasm of E. coli in H 2 O, indicating the usefulness of this OD-tracking method for the study of radical interactions with living cells.

Free radicals of an aromatic nature in air samples from iron foundries

Energy Technology Data Exchange (ETDEWEB)

Westerberg, L M

1982-01-01

Free radicals of relatively long life were identified as spin adducts of phenyl-N-tert-butylnitrone. Pyrolysis studies showed the radicals were oxy-radicals. The hyperfine splitting constants of spin adducts of radicals from the pyrolysis in air of benzo(a)pyrene, coal tar pitch, and moulding sand containing hard coal dust were the same as those of the radicals found in foundry air. Since these radicals can bind to DNA, they must be considered when estimating the hazardous effects of polluted air.

Free radicals in dicarboxylic acids: an e.s.r. study of radical conversions in γ-irradiated single crystals of glutaric acid and glutaric-2,2,4,4-d4 acid

International Nuclear Information System (INIS)

Bergene, R.; Minegishi, A.; Riesz, P.

1980-01-01

The γ-radiation-induced free radicals in single crystals of glutaric acid and glutaric-2,2,4,4-d 4 acid were studied in the temperature range 77-300 K by e.s.r. techniques. At 77 K the decarboxylation radical and the anion are stabilized. At higher temperatures the decarboxylation radical is found to be converted into a hydrogen abstraction radical with an activation energy of 6.3 +- 0.5 kcal/mole for the non-deuterated crystal. This radical is stable at room temperature. The anion seems to be converted to a unidentified intermediate radical which in turn is converted to the σ-acyl radical. An analysis of the g-value anisotropy and of the 13 C hyperfine splitting variation for this radical in the deuterated crystal is consistent with the assigned radical structure. By heat treatment the σ-acyl radical is converted to another form of the hydrogen abstraction radical with an activation energy of 9.6 +- 0.6 kcal/mole in the deuterated crystal. U.V.-light (lambda= 254 nm) transforms one of the room temperature radicals into the other. (author)

Introduction: Radical Teaching About Human Rights Part II

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Michael Bennett

2016-02-01

Full Text Available In our introduction to the first of these two issues of Radical Teacher devoted to “Radical Teaching About Human Rights,” we cautioned that all forms of Human Rights Education (HRE are not radical.  The problem, we pointed out, with rights discourse is that it can mask the politics of how rights are defined, whose rights are recognized, and how they are enforced.  This problem becomes evident when HRE is bound up with a neoliberal, or worse than neoliberal, perspective that points fingers at others and rallies troops for supposedly humanitarian interventions while eliding the role of the United States as an imperializing settler colonial state.  Fortunately, we have once again received several essays that seem to us to be aware of this danger and provide admirable examples of radical teaching about human rights.

Electron spin resonance of spin-trapped radicals of amines and polyamines. Hydroxyl radical reactions in aqueous solutions and. gamma. radiolysis in the solid state

Energy Technology Data Exchange (ETDEWEB)

Mossoba, M.M.; Rosenthal, I.; Riesz, P. (National Cancer Inst., Bethesda, MD (USA))

1982-06-15

The reactions of hydroxyl radicals with methylamine, dimethylamine, trimethylamine, diethylamine, sec-butylamine, ethylene-diamine, 1,3-diaminopropane, putrescine, cadaverine, 1,7-diaminoheptane, ornithine, spermidine, spermine, agmatine, and arcaine in aqueous solutions have been investigated by spin-trapping and esr. Hydroxyl radicals were generated by the uv photolysis of H/sub 2/O/sub 2/ and 2-methyl-2-nitrosopropane (MNP) was used as the spin-trap. The effects of ionizing radiation on the same polyamines in the polycrystalline state were also investigated. The free radicals produced by ..gamma..-radiolysis of these solids at room temperature in the absence of air were identified by dissolution in aqueous solutions of MNP. The predominant reaction of OH radicals with amines and polyamines below pH 7 was the abstraction of hydrogen atoms from a carbon that is not adjacent to the protonated amino group. For agmatine and arcaine which contain guanidinium groups abstraction occurred from the ..cap alpha..-CH. Dimethylamine was oxidized to the dimethylnitroxyl radical by H/sub 2/O/sub 2/ in the dark. ..gamma..-Radiolysis of polyamines in the polycrystalline state generated radicals due to H-abstraction from either the ..cap alpha..-Ch or from a carbon atom in the middle of the alkyl chain. The deamination radical was obtained from ornithine.

Oxidative degradation of lignin by photochemical and chemical radical generating systems

International Nuclear Information System (INIS)

Gold, M.H.; Kutsuki, H.; Morgan, M.A.

1983-01-01

Oxidation of specifically radiolabeled 14 C-lignins by UV/H 2 O 2 , Fenton's reagent, photosensitizing riboflavin, UV- and γ-irradiation was examined. In the presence of UV/H 2 O 2 , a hydroxyl radical (radicalOH) generating system, 14 C-methoxy, 2-[ 14 C-sidechain] and 14 C-ring labeled lignin were rapidly and extensively degraded as measured by gel filtration of the reaction products on Sephadex LH-20. This suggested that exposure to radicalOH leads to rapid, nonspecific lignin degradation. Rapid degradation of 14 C-methoxy, 2-[ 14 C-sidechain] and 14 C-ring labeled lignin also occurred in the presence of the radicalOH generating system, Fenton's reagent, confirming the primary role of radicalOH in these reactions. Photosensitizing riboflavin, also capable of effecting transformation of organic compounds via Type I hydrogen radical abstractions, caused extensive oxidative degradation of 14 C-methoxy labeled lignin and significant degradation of 2-[ 14 C-sidechain] and 14 C-ring labeled lignin. In addition, UV- and γ-irradiation caused slower but extensive degradation of the polymers, probably via radical type mechanisms. All of these results indicate that radicalOH as well as organic radical generating systems are effective agents for the purpose of degrading this heterogeneous, optically inactive and random biopolymer. (author)

Cirugía laparoscópica en urología: breve reseña histórica y estado actual del arte

Directory of Open Access Journals (Sweden)

José M. Campero, Dr.

2018-03-01

Full Text Available Resumen: La cirugía urológica tiene una antigüedad insospechada. El abordaje laparoscópico ha estado en el armamentario de la especialidad desde sus inicios. Sin embargo, recién en las últimas décadas y gracias al gran desarrollo tecnológico en imágenes e instrumental, es que se ha logrado introducir casi rutinariamente en la práctica urológica. Los beneficios de la cirugía laparoscópica son incuestionables y la evidencia nos muestra que cada vez será mayor la tendencia a realizar cirugías por esta vía. El advenimiento de la cirugía laparoscópica asistida por robot ha permitido en los últimos años implementar este abordaje para cirugías más complejas, que parecían imposibles de realizar de otra forma que no fuera por vía abierta. El propósito de esta revisión es describir con una perspectiva histórica el desarrollo de la cirugía mínimamente invasiva en urología y sus principales aplicaciones hoy en día. Summary: Urological surgery has an unsuspected age. The laparoscopic approach has been in the specialty's armamentarium since its beginnings. But only in recent decades and thanks to the great technological development in images and instruments, is that it has been almost routinely introduced into urological practice. The benefits of laparoscopy are unquestionable and the evidence shows that the tendency to perform surgeries in this way will be greater every time. The advent of robot assisted laparoscopic surgery in recent years has allowed surgeons to implement this approach for more complex surgeries, which seemed impossible to perform otherwise than by open surgery. The purpose of this review is to describe with a historical perspective the development of minimally invasive surgery in urology and its main applications today. Palabras clave: Laparoscopía, cirugía mínimamente invasiva, cirugía asistida por robot, robótica, Key words: Laparoscopy, minimally invasive surgery, robot-assisted surgery, robotics

Measuring Atmospheric Free Radicals Using Chemical Amplification

Science.gov (United States)

1988-05-01

CH 3Br, H2S, and SO2 [Logan et al., 1981]. Recently, the OH radical has been determined as the dominant loss mechanism for isoprene and monoterpenes ...W. Heaps, D. Philen, and T. McGee, Bondary Layer Measurements of the OH Radical in the Vicinity of an Isolated Power Plant Plume: SO2 and NO2

Radicals derived from acetaldehyde and vinyl alcohol.

Science.gov (United States)

Estep, Marissa L; Morgan, W James; Winkles, Alexander T; Abbott, Adam S; Villegas-Escobar, Nery; Mullinax, J Wayne; Turner, Walter E; Wang, Xiao; Turney, Justin M; Schaefer, Henry F

2017-10-18

Vinyl alcohol and acetaldehyde are isoelectronic products of incomplete butanol combustion. Along with the radicals resulting from the removal of atomic hydrogen or the hydroxyl radical, these species are studied here using ab initio methods as complete as coupled cluster theory with single, double, triple, and perturbative quadruple excitations [CCSDT(Q)], with basis sets as large as cc-pV5Z. The relative energies provided herein are further refined by including corrections for relativistic effects, the frozen core approximation, and the Born-Oppenheimer approximation. The effects of anharmonic zero-point vibrational energies are also treated. The syn conformer of vinyl alcohol is predicted to be lower in energy than the anti conformer by 1.1 kcal mol -1 . The alcoholic hydrogen of syn-vinyl alcohol is found to be the easiest to remove, requiring 84.4 kcal mol -1 . Five other radicals are also carefully considered, with four conformers investigated for the 1-hydroxyvinyl radical. Beyond energetics, we have conducted an overhaul of the spectroscopic literature for these species. Our results also provide predictions for fundamental modes yet to be reported experimentally. To our knowledge, the ν 3 (3076 cm -1 ) and ν 4 (2999 cm -1 ) C-H stretches for syn-vinyl alcohol and all but one of the vibrational modes for anti-vinyl alcohol (ν 1 -ν 14 ) are yet to be observed experimentally. For the acetyl radical, ν 6 (1035 cm -1 ), ν 11 (944 cm -1 ), ν 12 (97 cm -1 ), and accounting for our changes to the assignment of the 1419.9 cm -1 experimental mode, ν 10 (1441 cm -1 ), are yet to be observed. We have predicted these unobserved fundamentals and reassigned the experimental 1419.9 cm -1 frequency in the acetyl radical to ν 4 rather than to ν 10 . Our work also strongly supports reassignment of the ν 10 and ν 11 fundamentals of the vinoxy radical. We suggest that the bands assigned to the overtones of these fundamentals were in fact combination bands. Our

Analysis of radicals of irradiated garlic

International Nuclear Information System (INIS)

Kameya, Hiromi; Kaimori, Yoshihiko; Ukai, Mitsuko

2010-01-01

The detection method of gamma ray irradiated garlic using Electron Spin Resonance(ESR)spectroscopy was studied. The ESR spectrum was consisted of one singlet signal at g=2.00. This signal is due to an organic free radical. Upon irradiation, the intensity of the signal was increased. Also two signals due to cellulose radical were detected nearby the singlet. The intensity of the singlet signal was increased as depend on the increase of the irradiation dose level. (author)

Aminoxyl (nitroxyl) radicals in the early decomposition of the nitramine RDX.

Science.gov (United States)

Irikura, Karl K

2013-03-14

The explosive nitramine RDX (1,3,5-trinitrohexahydro-s-triazine) is thought to decompose largely by homolytic N-N bond cleavage, among other possible initiation reactions. Density-functional theory (DFT) calculations indicate that the resulting secondary aminyl (R2N·) radical can abstract an oxygen atom from NO2 or from a neighboring nitramine molecule, producing an aminoxyl (R2NO·) radical. Persistent aminoxyl radicals have been detected in electron-spin resonance (ESR) experiments and are consistent with autocatalytic "red oils" reported in the experimental literature. When the O-atom donor is a nitramine, a nitrosamine is formed along with the aminoxyl radical. Reactions of aminoxyl radicals can lead readily to the "oxy-s-triazine" product (as the s-triazine N-oxide) observed mass-spectrometrically by Behrens and co-workers. In addition to forming aminoxyl radicals, the initial aminyl radical can catalyze loss of HONO from RDX.

Spectroscopic evidence for an engineered, catalytically active Trp radical that creates the unique reactivity of lignin peroxidase.

Science.gov (United States)

Smith, Andrew T; Doyle, Wendy A; Dorlet, Pierre; Ivancich, Anabella

2009-09-22

The surface oxidation site (Trp-171) in lignin peroxidase (LiP) required for the reaction with veratryl alcohol a high-redox-potential (1.4 V) substrate, was engineered into Coprinus cinereus peroxidase (CiP) by introducing a Trp residue into a heme peroxidase that has similar protein fold but lacks this activity. To create the catalytic activity toward veratryl alcohol in CiP, it was necessary to reproduce the Trp site and its negatively charged microenvironment by means of a triple mutation. The resulting D179W+R258E+R272D variant was characterized by multifrequency EPR spectroscopy. The spectra unequivocally showed that a new Trp radical [g values of g(x) = 2.0035(5), g(y) = 2.0027(5), and g(z) = 2.0022(1)] was formed after the [Fe(IV)=O Por(*+)] intermediate, as a result of intramolecular electron transfer between Trp-179 and the porphyrin. Also, the EPR characterization crucially showed that [Fe(IV)=O Trp-179(*)] was the reactive intermediate with veratryl alcohol. Accordingly, our work shows that it is necessary to take into account the physicochemical properties of the radical, fine-tuned by the microenvironment, as well as those of the preceding [Fe(IV)=O Por(*+)] intermediate to engineer a catalytically competent Trp site for a given substrate. Manipulation of the microenvironment of the Trp-171 site in LiP allowed the detection by EPR spectroscopy of the Trp-171(*), for which direct evidence has been missing so far. Our work also highlights the role of Trp residues as tunable redox-active cofactors for enzyme catalysis in the context of peroxidases with a unique reactivity toward recalcitrant substrates that require oxidation potentials not realized at the heme site.

Temperature Effects on Free Radicals in Gamma-sterilized Beef

Science.gov (United States)

Pramanik, S. I.; Jahan, M. S.

1999-11-01

Gamma irradiation has become the method of choice for sterilizing frozen meat and their products to reduce levels of food-borne pathogens and to extend shelf life. In this report we have employed ESR technique for detection of free radicals in sterilized and non-sterilized dry beef without bone. We have also determined the heating effects on free radicals at temperatures 176^°C and 250^°C. Meat samples were dried in a food dehydrator at 60^°C and were packaged in dry N_2. They were then sterilized by γ-irradiation (2.5 MRad), ground into powder, and placed in ESR sample tubes. Non-sterilized powder samples were used as control. While all powder samples, sterilized or not, produced a broad single line in the ESR spectra with (Δ H_pp ~ 9 G) and g = 2.013, the radical concentration in the sterilized samples increased by a factor of five. Heat treatment at 176^°C produced similar radicals. But, when samples were heated 250^°C different radical species were formed which are characterized by narrow width (Δ H_pp ~ 6 G) and lower g-value (g =2.010). In contrast with previous work, where free radicals in chicken bones were reduced by heating [1], we observed an increase in concentration. Results of structural analyses of the radicals will be presented. Ref.[1]: Radiat. Phys. Chem., 49, 477-481, 1997. Work supported by Grants from the University of Memphis

Synthesis and Free Radical Scavenging Activity of New Hydroxybenzylidene Hydrazines.

Science.gov (United States)

Sersen, Frantisek; Gregan, Fridrich; Kotora, Peter; Kmetova, Jarmila; Filo, Juraj; Loos, Dusan; Gregan, Juraj

2017-05-29

Hydroxybenzylidene hydrazines exhibit a wide spectrum of biological activities. Here, we report synthesis and free radical scavenging activity of nine new N-(hydroxybenzylidene)-N'-[2,6-dinitro-4-(trifluoromethyl)]phenylhydrazines. The chemical structures of these compounds were confirmed by 1H-NMR, 13C-NMR, 19F-NMR, IR spectroscopy, LC-MS, and elemental analysis. The prepared compounds were tested for their activity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH), galvinoxyl radical (GOR), and 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulphonic acid (ABTS) radicals. The free radical scavenging activity expressed as SC50 values of these compounds varied in a wide range, from a strong to no radical scavenging effect. The most effective radical scavengers were hydroxybenzylidene hydrazines containing three hydroxyl groups in the benzylidene part of their molecules. The prepared compounds were also tested for their activity to inhibit photosynthetic electron transport in spinach chloroplasts. IC50 values of these compounds varied in wide range, from an intermediate to no inhibitory effect.

ESR study on free radicals trapped in crosslinked polytetrafluoroethylene (PTFE)

International Nuclear Information System (INIS)

Oshima, Akihiro; Tabata, Yoneho; Seguchi, Tadao

1997-01-01

Free radicals in crosslinked PTFE which formed by 60 Co γ-rays irradiation at 77 K and at room temperature were studied by electron spin resonance (ESR) spectroscopy. The crosslinked PTFE specimens with different crosslinking density were prepared by electron beam irradiation in the molten state. The ESR spectra observed in the irradiated crosslinked PTFE are much different from those in non-crosslinked PTFE (virgin); a broad singlet component increases with increasing the crosslinking density, G-value of radicals is much higher in crosslinked PTFE than in non-crosslinked one. Free radicals related to the broad component are trapped in the non-crystalline region of crosslinked PTFE and rather stable at room temperature, whereas radicals trapped in amorphous non-crosslinked PTFE are unstable at room temperature. It is thought that most of free radicals trapped in the crosslinked PTFE are formed in the crosslinked amorphous region. The trapped radicals decays around 383 K (110 o C) due to the molecular motion of α-relaxation. (Author)

Free Radical Scavenging Activities of Methanol Extract and ...

African Journals Online (AJOL)

Michael Horsfall

fractions were subjected to in vitro antioxidant evaluation using the DPPH free radical scavenging ... The crude extract has IC-50 value for radical scavenging activity of 5μg/mL which was .... effective concentration of the sample that is required.

EPR assessment of the free radicals in irradiated foodstuffs

International Nuclear Information System (INIS)

Tencheva, S.; Katsareva, Ts.; Malinovski, A.; Kabasanov, K.

1985-01-01

In the hygienic assessment of radiation treated foodstuffs the study of free radicals formed during radiation exposure, their concentration and disintegration kinetics are of particular interest. In the work presented the concentration of the free radicals in irradiated prunes, nuts and corn is determined using EPR spectroscopy. The following doses are applied: 2, 10 and 20 kGy for prunes, 1, 10 and 20 kGy for nuts, and 0.75, 10 and 20 kGy for corn. EPR measurements are done immediately after the irradiation: 24 hours, and 3, 6, 9 and 15 days after the exposure. In the small radiation doses the formation of single radicals is observed. In doses of 10 kGy the spectra get complicated with the occurence of radicals R 1 , R 2 , R 3 and R 4 . The assessment of radicals proves to be a prospective method for the identification and determination of the preservation terms of foodstuffs

Celulitis por citomegalovirus

Directory of Open Access Journals (Sweden)

A. Ruiz Lascano

2002-12-01

Full Text Available Las lesiones cutáneas por citomegalovirus (CMV son infrecuentes y a menudo una manifestación tardía de una enfermedad sistémica, que generalmente anuncia un curso fatal. Comunicamos un caso de celulitis por CMV: una mujer de 70 años con trasplante renal efectuado 1 mes antes de la consulta, terapia inmunosupresora con ciclosporina A y metilprednisona. La paciente ingresó por fiebre, dolor e impotencia funcional en pierna derecha. Comprobamos la existencia de una placa de 8 por 4 cm eritematoedematosa. La tratamos con antibióticos sin mejoría, por lo que realizamos un estudio histopatológico de piel que mostró cambios citopáticos compatibles con infección por CMV. Los cultivos bacteriológicos y micológicos fueron negativos. La inmunohistoquímica específica para CMV y el estudio de reacción en cadena de la polimerasa (PCR de la biopsia de piel fueron positivas, al igual que la antigenemia. El tratamiento con ganciclovir produjo la mejoría del cuadro clínico. En la literatura revisada no hemos encontrado la celulitis como manifestación de enfermedad cutánea por CMV.

Thermochemical properties for isooctane and carbon radicals: computational study.

Science.gov (United States)

Snitsiriwat, Suarwee; Bozzelli, Joseph W

2013-01-17

Thermochemical properties for isooctane, its internal rotation conformers, and radicals with corresponding bond energies are determined by use of computational chemistry. Enthalpies of formation are determined using isodesmic reactions with B3LYP density function theory and composite CBS-QB3 methods. Application of group additivity with comparison to calculated values is illustrated. Entropy and heat capacities are determined using geometric parameters, internal rotor potentials, and frequencies from B3LYP/6-31G(d,p) calculations for the lowest energy conformer. Internal rotor potentials are determined for the isooctane parent and for the primary, secondary, and tertiary radicals in order to identify isomer energies. Intramolecular interactions are shown to have a significant effect on the enthalpy of formation of the isooctane parent and its radicals. The computed standard enthalpy of formation for the lowest energy conformers of isooctane from this study is -54.40 ± 1.60 kcal mol(-1), which is 0.8 kcal mol(-1) lower than the evaluated experimental value -53.54 ± 0.36 kcal mol(-1). The standard enthalpy of formation for the primary radical for a methyl on the quaternary carbon is -5.00 ± 1.69 kcal mol(-1), for the primary radical on the tertiary carbon is -5.18 ± 1.69 kcal mol(-1), for the secondary isooctane radical is -9.03 ± 1.84 kcal mol(-1), and for the tertiary isooctane radical is -12.30 ± 2.02 kcal mol(-1). Bond energy values for the isooctane radicals are 100.64 ± 1.73, 100.46 ± 1.73, 96.41 ± 1.88 and 93.14 ± 2.05 kcal mol(-1) for C3•CCCC2, C3CCCC2•, C3CC•CC2, and C3CCC•C2, respectively. Entropy and heat capacity values are reported for the lowest energy homologues.

The research progress of several kinds of free radical scavengers

International Nuclear Information System (INIS)

Qian Liren; Huang Yuecheng; Cai Jianming

2009-01-01

Ionization radiation can generate free radicals in biological system, which could induce lipid peroxi-dation, biomacromolecule and biomembrane damage, lost of cell function, cell cycle disturbance, genetic mutation and so on. The scavenging free radicals can protect organism from radiation damage. Many radio-protective agents, such as amylase, hydroxyl-benzene derivatives, hormone, vitamin, have great abilities to protect organism from radiation via scavenging free radicals. In this paper, we mainly review the free radical scavenging effects of several kinds of radio-protective agents. (authors)

Why Nature Uses Radical SAM Enzymes so Widely: Electron Nuclear Double Resonance Studies of Lysine 2,3-Aminomutase Show the 5'-dAdo• "Free Radical" Is Never Free.

Science.gov (United States)

Horitani, Masaki; Byer, Amanda S; Shisler, Krista A; Chandra, Tilak; Broderick, Joan B; Hoffman, Brian M

2015-06-10

Lysine 2,3-aminomutase (LAM) is a radical S-adenosyl-L-methionine (SAM) enzyme and, like other members of this superfamily, LAM utilizes radical-generating machinery comprising SAM anchored to the unique Fe of a [4Fe-4S] cluster via a classical five-membered N,O chelate ring. Catalysis is initiated by reductive cleavage of the SAM S-C5' bond, which creates the highly reactive 5'-deoxyadenosyl radical (5'-dAdo•), the same radical generated by homolytic Co-C bond cleavage in B12 radical enzymes. The SAM surrogate S-3',4'-anhydroadenosyl-L-methionine (anSAM) can replace SAM as a cofactor in the isomerization of L-α-lysine to L-β-lysine by LAM, via the stable allylic anhydroadenosyl radical (anAdo•). Here electron nuclear double resonance (ENDOR) spectroscopy of the anAdo• radical in the presence of (13)C, (2)H, and (15)N-labeled lysine completes the picture of how the active site of LAM from Clostridium subterminale SB4 "tames" the 5'-dAdo• radical, preventing it from carrying out harmful side reactions: this "free radical" in LAM is never free. The low steric demands of the radical-generating [4Fe-4S]/SAM construct allow the substrate target to bind adjacent to the S-C5' bond, thereby enabling the 5'-dAdo• radical created by cleavage of this bond to react with its partners by undergoing small motions, ∼0.6 Å toward the target and ∼1.5 Å overall, that are controlled by tight van der Waals contact with its partners. We suggest that the accessibility to substrate and ready control of the reactive C5' radical, with "van der Waals control" of small motions throughout the catalytic cycle, is common within the radical SAM enzyme superfamily and is a major reason why these enzymes are the preferred means of initiating radical reactions in nature.

Changes in free-radical scavenging ability of kombucha tea during fermentation.

Science.gov (United States)

Jayabalan, R; Subathradevi, P; Marimuthu, S; Sathishkumar, M; Swaminathan, K

2008-07-01

Kombucha tea is a fermented tea beverage produced by fermenting sugared black tea with tea fungus (kombucha). Free-radical scavenging abilities of kombucha tea prepared from green tea (GTK), black tea (BTK) and tea waste material (TWK) along with pH, phenolic compounds and reducing power were investigated during fermentation period. Phenolic compounds, scavenging activity on DPPH radical, superoxide radical (xanthine-xanthine oxidase system) and inhibitory activity against hydroxyl radical mediated linoleic acid oxidation (ammonium thiocyanate assay) were increased during fermentation period, whereas pH, reducing power, hydroxyl radical scavenging ability (ascorbic acid-iron EDTA) and anti-lipid peroxidation ability (thiobarbituric assay) were decreased. From the present study, it is obvious that there might be some chances of structural modification of components in tea due to enzymes liberated by bacteria and yeast during kombucha fermentation which results in better scavenging performance on nitrogen and superoxide radicals, and poor scavenging performance on hydroxyl radicals. Copyright © 2007 Elsevier Ltd. All rights reserved.

prepared via atom transfer radical polymerization, reverse atom

Indian Academy of Sciences (India)

Synthesis and characterization of poly(2-ethylhexyl acrylate) prepared via atom transfer radical polymerization, reverse atom transfer radical polymerization and ... Zydex Industries, 25-A Gandhi Oil Mill Compound, Gorwa, Vadodara 390 016, India; Rubber Technology Centre, Indian Institute of Technology Kharagpur, ...

Electronic states of aryl radical functionalized graphenes: Density functional theory study

Science.gov (United States)

Tachikawa, Hiroto; Kawabata, Hiroshi

2016-06-01

Functionalized graphenes are known as a high-performance molecular device. In the present study, the structures and electronic states of the aryl radical functionalized graphene have been investigated by the density functional theory (DFT) method to elucidate the effects of functionalization on the electronic states of graphene (GR). Also, the mechanism of aryl radical reaction with GR was investigated. The benzene, biphenyl, p-terphenyl, and p-quaterphenyl radicals [denoted by (Bz) n (n = 1-4), where n means numbers of benzene rings in aryl radical] were examined as aryl radicals. The DFT calculation of GR-(Bz) n (n = 1-4) showed that the aryl radical binds to the carbon atom of GR, and a C-C single bond was formed. The binding energies of aryl radicals to GR were calculated to be ca. 6.0 kcal mol-1 at the CAM-B3LYP/6-311G(d,p) level. It was found that the activation barrier exists in the aryl radical addition: the barrier heights were calculated to be 10.0 kcal mol-1. The electronic states of GR-(Bz) n were examined on the basis of theoretical results.

Free radical scavenging properties of some wine probes

International Nuclear Information System (INIS)

Stasko, A.; Liptakova, M.; Malik, F.

1999-01-01

There are preliminary results of investigation of scavenging properties of 8 probes of Slovak wines (consisting of one reference, 3 probes of white wine and 4 probes of red wine). According to the literature so far, wine probes contain paramagnetic species (Mn 2+ , characterised with sextet spectrum, and a singlet line around g=2,00). In our probes we observed Mn 2+ signals, but no significant evidence for a single line of free radical was found. We can conclude that Mn 2+ content in the red wines is generally higher than in the white ones. Further, we investigated the scavenging activities of the probes adding solution of dinitropicryl hydrazyl (DPPH-stable radical) to them. Their ability to terminate free radicals resulted in the decrease of the final DPPH concentrations in the probes. The red wines have significantly higher capability to scavenge free radicals than the probes of white wines. (authors)

Chemical determination of free radical-induced damage to DNA.

Science.gov (United States)

Dizdaroglu, M

1991-01-01

Free radical-induced damage to DNA in vivo can result in deleterious biological consequences such as the initiation and promotion of cancer. Chemical characterization and quantitation of such DNA damage is essential for an understanding of its biological consequences and cellular repair. Methodologies incorporating the technique of gas chromatography/mass spectrometry (GC/MS) have been developed in recent years for measurement of free radical-induced DNA damage. The use of GC/MS with selected-ion monitoring (SIM) facilitates unequivocal identification and quantitation of a large number of products of all four DNA bases produced in DNA by reactions with hydroxyl radical, hydrated electron, and H atom. Hydroxyl radical-induced DNA-protein cross-links in mammalian chromatin, and products of the sugar moiety in DNA are also unequivocally identified and quantitated. The sensitivity and selectivity of the GC/MS-SIM technique enables the measurement of DNA base products even in isolated mammalian chromatin without the necessity of first isolating DNA, and despite the presence of histones. Recent results reviewed in this article demonstrate the usefulness of the GC/MS technique for chemical determination of free radical-induced DNA damage in DNA as well as in mammalian chromatin under a vast variety of conditions of free radical production.

Free radicals in cellulose containing food detected by ESR

International Nuclear Information System (INIS)

Abe, Aika; Yogo, Satsuki; Ichii, Akane; Ukai, Mitsuko

2003-01-01

Using electron spin resonance (ESR) spectroscopy, we revealed three radical species in cellulose containing foods, pepper and green tea. These are commercially available in Japan. The representative ESR spectrum is composed of a sextet centered at g=2.0, a singlet at the same g-value, and a singlet at g=4.0. The first one is attributable to a signal with hyperfine (hf) interactions of Mn 2+ ion (hf constant: 7.4 mT). The second one is due to an organic free radical, the third one may be originated from Fe 3+ ion. The progressive saturation behavior (PSB) of the ESR at various microwave power levels were indicated different relaxation behaviors of in those radicals. Namely, the peak intensity of the organic free radical component decreases in a monotonic fashion, whereas the Mn 2+ and Fe 3+ ESR signals substantially keep constant. This reflects the evidence of three independent radical species. The ESR spectrum of the cellulose containing foods shows the same spectral feature irrespective of the tea or pepper. Upon gamma irradiation, a new pair of signals appeared. The PSB of the pair peaks after the irradiation showed a quite different as compared with the free radical centered at g=2. (author)

In vitro free radical scavenging activity of platinum nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Aki; Kajita, Masashi; Kim, Juewon; Kanayama, Atsuhiro; Miyamoto, Yusei [Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Bioscience Building 402, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562 (Japan); Takahashi, Kyoko; Mashino, Tadahiko, E-mail: yusei74@k.u-tokyo.ac.j [Department of Pharmaceutical Sciences, Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato, Tokyo 105-8512 (Japan)

2009-11-11

A polyacrylic acid (PAA)-protected platinum nanoparticle species (PAA-Pt) was prepared by alcohol reduction of hexachloroplatinate. The PAA-Pt nanoparticles were well dispersed and homogeneous in size with an average diameter of 2.0 {+-} 0.4 nm (n = 200). We used electron spin resonance to quantify the residual peroxyl radical AOO. generated from 2,2-azobis (2-aminopropane) dihydrochloride (AAPH) by thermal decomposition in the presence of O{sub 2} and a spectrophotometric method to quantify the residual 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. PAA-Pt scavenged these two radicals in a dose-dependent manner. Platinum was the functional component. PAA-Pt reduced the rate of oxygen consumption required for linoleic acid peroxidation initiated by AOO. generated from AAPH, indicating inhibition of the propagation of linolate peroxidation. A thiobarbituric acid test also revealed dose-dependent inhibition of the linolate peroxidation by PAA-Pt. Fifty micromolar platinum, as PAA-Pt, completely quenched 250 {mu}M DPPH radical for 5 min. Even when twice diluted in half, the PAA-Pt still quenched 100% of the 250 {mu}M DPPH radical. The scavenging activity of PAA-Pt is durable. These observations suggest that PAA-Pt is an efficient scavenger of free radicals.

Resveratrol products resulting by free radical attack

Energy Technology Data Exchange (ETDEWEB)

Bader, Yvonne; Quint, R.M. [Section Radiation Biology, Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, UZAII, Althanstrasse 14, A-1090 Vienna (Austria); Getoff, Nikola [Section Radiation Biology, Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, UZAII, Althanstrasse 14, A-1090 Vienna (Austria)], E-mail: nikola.getoff@univie.ac.at

2008-06-15

Trans-resveratrol (trans-3,4',5-trihydroxystilbene; RES), which is contained in red wine and many plants, is one of the most relevant and extensively investigated stilbenes with a broad spectrum of biological activities. Among other duties, RES has been reported to have anti-carcinogenetic activities, which could be attributed to its antioxidant properties. The degradation of RES was studied under various conditions. The products (aldehydes, carboxylic acids, etc.) generated from RES by the attack of free radicals were registered as a function of the radical concentration (absorbed radiation dose). Based on the obtained data it appears that the OH radicals are initiating the rather complicated process, which involves of the numerous consecutive reactions. A possible starting reaction mechanism is presented.

Optimal pain management for radical prostatectomy surgery

DEFF Research Database (Denmark)

Joshi, Grish P; Jaschinski, Thomas; Bonnet, Francis

2015-01-01

BACKGROUND: Increase in the diagnosis of prostate cancer has increased the incidence of radical prostatectomy. However, the literature assessing pain therapy for this procedure has not been systematically evaluated. Thus, optimal pain therapy for patients undergoing radical prostatectomy remains...... controversial. METHODS: Medline, Embase, and Cochrane Central Register of Controlled Trials were searched for studies assessing the effects of analgesic and anesthetic interventions on pain after radical prostatectomy. All searches were conducted in October 2012 and updated in June 2015. RESULTS: Most...... treatments studied improved pain relief and/or reduced opioid requirements. However, there were significant differences in the study designs and the variables evaluated, precluding quantitative analysis and consensus recommendations. CONCLUSIONS: This systematic review reveals that there is a lack...

Test for antioxidant ability by scavenging long-lived mutagenic radicals in mammalian cells and by blood test with intentional radicals: an application of gallic acid

International Nuclear Information System (INIS)

Kumagai, Jun; Kawaura, Tomoko; Miyazaki, Tetsuo; Prost, Michel; Prost, Emmanuelle; Watanabe, Masami; Quetin-Leclercq, J.Joeelle

2003-01-01

Antioxidant ability of gallic acid (GA) are determined both by electron spin resonance measurement of long-lived radicals produced in γ-ray irradiated Syrian golden hamster embryo cells with GA and by hemolysis measurement with GA when blood cells are submitted to radicals. Scavenging properties of GA are determined by the reaction rate constant with long-lived mutagenic radicals in the cells while the blood test allows to analyze the global effects of this compound: radical scavenger+metal ion chelator+regeneration of intra- and extra-cellular antioxidant

Oxidation of spin-traps by chlorine dioxide (ClO2) radical in aqueous solutions: first ESR evidence of formation of new nitroxide radicals.

Science.gov (United States)

Ozawa, T; Miura, Y; Ueda, J

1996-01-01

The reactivities of the chlorine dioxide (ClO2), which is a stable free radical towards some water-soluble spin-traps were investigated in aqueous solutions by an electron spin resonance (ESR) spectroscopy. The ClO2 radical was generated from the redox reaction of Ti3+ with potassium chlorate (KClO3) in aqueous solutions. When one of the spin-traps, 5,5-dimethyl-1-pyrroline N-oxide (DMPO), was included in the Ti3+-KClO3 reaction system, ESR spectrum due to the ClO2 radical completely disappeared and a new ESR spectrum [aN(1) = 0.72 mT, aH(2) = 0.41 mT], which is different from that of DMPO-ClO2 adduct, was observed. The ESR parameters of this new ESR signal was identical to those of 5,5-dimethylpyrrolidone-(2)-oxyl-(1) (DMPOX), suggesting the radical species giving the new ESR spectrum is assignable to DMPOX. The similar ESR spectrum consisting of a triplet [aN(1) = 0.69 mT] was observed when the derivative of DMPO, 3,3,5,5-tetramethyl-1-pyrroline N-oxide (M4PO) was included in the Ti3+-KClO3 reaction system. This radical species is attributed to the oxidation product of M4PO, 3,3,5,5-tetramethylpyrrolidone-(2)-oxyl-(1) (M4POX). When another nitrone spin-trap, alpha-(4-pyridyl-1-oxide)-N-t-butylnitrone (POBN) was used as a spin-trap, the ESR signal intensity due to the ClO2 radical decreased and a new ESR signal consisting of a triplet [aN(1) = 0.76 mT] was observed. The similar ESR spectrum was observed when N-t-butyl-alpha- nitrone (PBN) was used as a spin-trap. This ESR parameter [a(N)(1) = 0.85 mT] was identical to the oxidation product of PBN, PBNX. Thus, the new ESR signal observed from POBN may be assigned to the oxidation product of POBN, POBNX. These results suggest that the ClO2, radical does not form the stable spin adducts with nitrone spin-traps, but oxidizes these spin-traps to give the corresponding nitroxyl radicals. On the other hand, nitroso spin-traps, 5,5-dibromo-4-nitrosobenzenesulfonate (DBNBS), and 2-methyl-2-nitrosopropane (MNP) did not trap

Effect of radiation sterilization on free radicals content in dry beverages

International Nuclear Information System (INIS)

Hidayati, Nur; Sudiro, Sutjipto; Maha, Munsiah

1998-01-01

This study was done to determine free radicals content in several dry beverages, namely instant coffee, milk powder, cane sugar, nutrisari, tea, and cacao powder after radiation-sterilization at 25 kGy and stored at room (24 o C) and freezing (-13 o C) temperatures. Each sample was vacuum-packed in Al foil laminate pouches, then irradiated at 25 kGy in dry ice temperature. Free radicals contents in some samples after being dissolved or soaked in hot water (73 o C) then freeze-dried were also measured. The free radicals content was measured using Electron Spin Resonance (ESR) Spectroscopy and expressed in spectrum area/g in arbitrary unit. The results showed that free radicals content increased after irradiation, but it decreased immediately after storage especially at room temperature. After about 5 months storage either at room or freezing temperature, free radicals contents of irradiated coffee, milk, powder and cacao powder were similar to those of the unirradiated control, while in tea sample stored at freezing temperature, the free radicals content was still a little bit higher than that stored at room temperature which was already similar to the control. Free radicals content of irradiated sugar as well as nutrisari was higher than the other samples, and the radicals were relatively stable either at room or freezing temperatures. However, after dissolving or soaking the samples in water, the ESR spectra or free radicals contents of the irradiated samples were found to be identical to the control. This indicates that free radicals formed by irradiation in the samples disappear because termination. (authors)

Copper-catalyzed radical carbooxygenation: alkylation and alkoxylation of styrenes.

Science.gov (United States)

Liao, Zhixiong; Yi, Hong; Li, Zheng; Fan, Chao; Zhang, Xu; Liu, Jie; Deng, Zixin; Lei, Aiwen

2015-01-01

A simple copper-catalyzed direct radical carbooxygenation of styrenes is developed utilizing alkyl bromides as radical resources. This catalytic radical difunctionalization accomplishes both alkylation and alkoxylation of styrenes in one pot. A broad range of styrenes and alcohols are well tolerated in this transformation. The EPR experiment shows that alkyl halides could oxidize Cu(I) to Cu(II) in this transformation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The entry of free radicals into polystyrene latex particles

International Nuclear Information System (INIS)

Adams, M.E.; Trau, M.; Gilbert, R.C.; Napper, D.R.

1988-01-01

Mechanistic understanding of the processes governing the kinetics of emulsion polymerization has both scientific and technical interest. One component of this process that is poorly understood at present is that of free radical entry into latex particles. Measurements were made of the entry rate coefficient as a function of temperature for free radicals entering polystyrene latex particles in seeded emulsion polymerizations initiated by γ-rays. The activation energy for entry was found to be less than 24 ± 3 kJ mol -1 , consistent with entry being controlled by a physical (e.g. diffusional) rather than a chemical process. Measurement of the entry rate coefficient as a function of the γ-ray dose rate suggested that the factors that determine the entry rate when the primary free radicals are uncharged are similar to those that determine the entry rate for charged free radicals derived from chemical initiation by peroxydisulfate. This result was consistent with measurements of the entry rate coefficient of charged free radicals derived from peroxydisulfate; these data were found to be virtually independent of both the extent of the latex surface coverage by the anionic surfactant sodium dodecyl sulfate and the ionic strength of the continuous phase. The data refute several proposals given in the literature for the rate-determining step for entry, being inconsistent with control by collision of free radicals with the latex particles, surfactant desorption, and an electrostatic barrier arising from the colloidal nature of the entering free radical. The origin of the activation energy for entry remains obscure

pi-Dimers of end-capped oligopyrrole cation radicals

NARCIS (Netherlands)

Haare, van J.A.E.H.; Groenendaal, L.; Havinga, E.E.; Janssen, R.A.J.; Meijer, E.W.

1996-01-01

In two consecutive one-electron oxidations, oligopyrroles substituted with phenyl capping groups (PhPynPh, n = 2–4) can be oxidized reversibly to give stable cation radicals and dications. Spectroelectrochemical studies give direct evidence that diamagnetic p-dimers of cation radicals are formed in

Robot-assisted radical prostatectomy is a safe procedure

DEFF Research Database (Denmark)

Thomsen, Frederik Birkebæk; Berg, Kasper Drimer; Hvarness, Helle

2013-01-01

We present our departmental experience with robot-assisted radical prostatectomy and describe complications and early results for the first 239 consecutive patients.......We present our departmental experience with robot-assisted radical prostatectomy and describe complications and early results for the first 239 consecutive patients....

Generation of radicals and antimalarial activity of dispiro-1,2,4-trioxolanes

Science.gov (United States)

Denisov, E. T.; Denisova, T. G.

2013-01-01

The kinetic schemes of the intramolecular oxidation of radicals generated from substituted dispiro-1,2,4-trioxolanes (seven compounds) in the presence of Fe2+ and oxygen were built. Each radical reaction was defined in terms of enthalpy, activation energy, and rate constant. The kinetic characteristics were calculated by the intersecting parabolas method. The competition between the radical reactions was considered. The entry of radicals generated by each compound into the volume was calculated. High antimalarial activity was found for 1,2,4-trioxolanes, which generated hydroxyl radicals. The structural features of trioxolanes responsible for the generation of hydroxyl radicals were determined.

Role of free radicals in radiation chemical aging

Energy Technology Data Exchange (ETDEWEB)

Greenstock, C L

1986-01-01

Ionizing radiation initiates chemical changes in DNA, phospholipid membranes and other critical cell targets, that, if allowed to accumulate unrepaired, may lead to aging and other chronic effects. The chemical effects are free radical mediated, the principal damaging species being radical OH and to a lesser extent O2-anion radical and the molecular product H/sub 2/O/sub 2/. Many compounds can act in combination with ionizing radiation, to amplify the potential oxidative stress. Chemicals, ultra-violet light, lipid peroxides and their breakdown products may increase the extent of acute and chronic radiobiological effects.

Homegrown religious radicalization and the quest for belonging

DEFF Research Database (Denmark)

Khawaja, Iram

this seemingly religious radicalization, from the point of view of the youngsters, by drawing on a study of young Muslims in religious communities in Copenhagen and combining it with existing blogs, twitter profiles etc. of youngsters sympathizing with Islamic radicalized movements. What are the youngsters...... framework based on a focus on belonging, self-construction and the sense of community will be proposed. The framework will be utilized in an analysis of narratives from youngsters who have chosen a radicalized path in life. The paper will shed light on how the sense of and yearning for belonging...

Transformations of dissolved organic matter induced by UV photolysis, Hydroxyl radicals, chlorine radicals, and sulfate radicals in aqueous-phase UV-Based advanced oxidation processes.

Science.gov (United States)

Varanasi, Lathika; Coscarelli, Erica; Khaksari, Maryam; Mazzoleni, Lynn R; Minakata, Daisuke

2018-05-15

Considering the increasing identification of trace organic contaminants in natural aquatic environments, the removal of trace organic contaminants from water or wastewater discharge is an urgent task. Ultraviolet (UV) and UV-based advanced oxidation processes (AOPs), such as UV/hydrogen peroxide (UV/H 2 O 2 ), UV/free chlorine and UV/persulfate, are attractive and promising approaches for the removal of these contaminants due to the high reactivity of active radical species produced in these UV-AOPs with a wide variety of organic contaminants. However, the removal efficiency of trace contaminants is greatly affected by the presence of background dissolved organic matter (DOM). In this study, we use ultrahigh resolution mass spectrometry to evaluate the transformation of a standard Suwanee River fulvic acid DOM isolate in UV photolysis and UV-AOPs. The use of probe compounds allows for the determination of the steady-state concentrations of active radical species in each UV-AOP. The changes in the H/C and O/C elemental ratios, double bond equivalents, and the low-molecular-weight transformation product concentrations of organic acids reveal that different DOM transformation patterns are induced by each UV-AOP. By comparison with the known reactivities of each radical species with specific organic compounds, we mechanistically and systematically elucidate the molecular-level DOM transformation pathways induced by hydroxyl, chlorine, and sulfate radicals in UV-AOPs. We find that there is a distinct transformation in the aliphatic components of DOM due to HO• in UV/H 2 O 2 and UV/free chlorine. Cl• induced transformation of olefinic species is also observed in the UV/free chlorine system. Transformation of aromatic and olefinic moieties by SO 4 •- are the predominant pathways in the UV/persulfate system. Copyright © 2018 Elsevier Ltd. All rights reserved.

Antioxidant Effects of Herbal Tea Leaves from Yacon (Smallanthus sonchifolius) on Multiple Free Radical and Reducing Power Assays, Especially on Different Superoxide Anion Radical Generation Systems.

Science.gov (United States)

Sugahara, Shintaro; Ueda, Yuto; Fukuhara, Kumiko; Kamamuta, Yuki; Matsuda, Yasushi; Murata, Tatsuro; Kuroda, Yasuhiro; Kabata, Kiyotaka; Ono, Masateru; Igoshi, Keiji; Yasuda, Shin

2015-11-01

Yacon (Smallanthus sonchifolius), a native Andean plant, has been cultivated as a crop and locally used as a traditional folk medicine for the people suffering from diabetes and digestive/renal disorders. However, the medicinal properties of this plant and its processed foods have not been completely established. This study investigates the potent antioxidative effects of herbal tea leaves from yacon in different free radical models and a ferric reducing model. A hot-water extract exhibited the highest yield of total polyphenol and scavenging effect on 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical among four extracts prepared with hot water, methanol, ethanol, and ethylacetate. In addition, a higher reducing power of the hot-water extract was similarly demonstrated among these extracts. Varying concentrations of the hot-water extract resulted in different scavenging activities in four synthetic free radical models: DPPH radical (EC50 28.1 μg/mL), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical (EC50 23.7 μg/mL), galvinoxyl radical (EC50 3.06 μg/mL), and chlorpromazine cation radical (EC50 475 μg/mL). The yacon tea-leaf extract further demonstrated superoxide anion (O2(-)) radical scavenging effects in the phenazine methosulfate-NADH-nitroblue tetrazolium (EC50 64.5 μg/mL) and xanthine oxidase assay systems (EC50 20.7 μg/mL). Subsequently, incubating human neutrophilic cells in the presence of the tea-leaf extract could suppress the cellular O2(-) radical generation (IC50 65.7 μg/mL) in a phorbol 12-myristate 13-acetate-activated cell model. These results support yacon tea leaves may be a good source of natural antioxidants for preventing O2(-) radical-mediated disorders. Yacon has been considered to be a potent alternative food source for patients who require a dietary cure in regional area, while the leaf part has been provided and consumed as an herbal tea in local markets. We demonstrated here potent antioxidative effects of the tea

TRANSITION METAL CATALYSIS IN CONTROLLED RADICAL POLYMERIZATION: ATOM TRANSFER RADICAL POLYMERIZATION. (R826735)

Science.gov (United States)

Novel and diversified macromolecular structures, which include polymers with designed topologies (top), compostions (middle), and functionalities (bottom), can be prepared by atom transfer radical polymerization processes. These polymers can be synthesized from a large variety of...

Quantification of Radicals Generated in a Sonicator

Directory of Open Access Journals (Sweden)

Kassim Badmus

2016-06-01

Full Text Available The hydroxyl radical (OH• is a powerful oxidant produced as a consequence of cavitation in water. It can react nonspecifically in breaking down persistent organic pollutants in water into their mineral form. It can also recombine to form hydrogen peroxide which is very useful in water treatment. In this study, terephthalic acid (TA and potassium iodide dosimetry were used to quantify and investigate the behaviour of the generated OH radical in a laboratory scale sonicator. The 2-hydroxyl terephthalic acid (HTA formed during terephthalic acid dosimetry was determined by optical fibre spectrometer. The production rate of HTA served as a means of evaluating and characterizing the OH• generated over given time in a sonicator. The influence of sonicator power intensity, solution pH and irradiation time upon OH• generation were investigated. Approximately 2.2 ´ 10-9 M s-1 of OH radical was generated during the sonication process. The rate of generation of the OH radicals was established to be independent of the concentration of the initial reactant. Thus, the rate of generation of OH• can be predicted by zero order kinetics in a sonicator.

GRAVIDEZ NA ADOLESCÊNCIA: PERCEPÇÕES, COMPORTAMENTOS E EXPERIÊNCIAS DE FAMILIARES

Directory of Open Access Journals (Sweden)

Tereza Alves de Souza

2012-01-01

Full Text Available El embarazo en la adolescencia es un grave problema social y de salud pública, por las consecuencias a la madre y al concepto. Estudio cualitativo, cuyo objetivo fue aprehender el significado del embarazo en la adolescencia para los familiares. Desarrollado con siete familias de adolescentes embarazadas y/o que tuvieron parto en 2010, asistidas en Centro de Salud de la Familia de Fortaleza-CE, Brasil. Las informaciones fueran buscadas en guión de entrevista semiestructurada, en hogares. Los resultados fueron organizados en temáticas y analizados de acuerdo con la literatura. Se detectaron manifestaciones de sentimientos y reacciones ocasionadas por la singularidad de la historia, dinámica familiar, contexto sociocultural y económico vivido por la familia. Diversas causas contribuyeron para el embarazo precoz, haciéndose necesario enfoque amplio de profesionales de salud, familiares, comunidad y gobernantes, como también la inclusión de familiares o de personas significativas en atención holística y humanizada.

Teoria da percepção no behaviorismo radical

Directory of Open Access Journals (Sweden)

Carlos Eduardo Lopes

Full Text Available A percepção é explicada por Skinner através do conceito de comportamento perceptivo - um comportamento complexo que se inter-relaciona com muitos outros. O estudo da percepção na teoria skinneriana pode ser dividido em duas etapas: estudo do comportamento perceptivo como precorrente e estudo dos precorrentes do comportamento perceptivo. No primeiro caso, a investigação passa pelo processo de resolução de problemas, no qual o comportamento perceptivo desempenha um papel fundamental modificando o ambiente, o que permite a emissão do comportamento discriminativo e a solução do problema. No segundo caso, a investigação trata com uma série de outros comportamentos, tais como, propósito, atenção, e consciência, que modificam a probabilidade de emissão do comportamento perceptivo. A análise das relações entre o comportamento perceptivo e demais comportamentos culmina no esboço de uma teoria da percepção no behaviorismo radical, que é mais convincente do que explicações mentalistas que fazem uso da "teoria da cópia".

Reactions of carbon radicals generated by 1,5-transposition of reactive centers

Directory of Open Access Journals (Sweden)

ZIVORAD CEKOVIC

2005-03-01

Full Text Available Radical intermediates can undergo specific reactions, such as intramolecular rearrangements, i.e., the transpositions of radical centers, which are not known in classical ionic organic reactions. 1,5-Transposition of a radical center to a non-activated carbon atom are of great synthetic importance. It can be successfully applied for the introduction of different functional groups (oxygen, nitrogen, sulfur, halogens onto a carbon atom remote from the present functional group. In addition to functionalization of a remote non-activated carbon atom, the formation of new C-C bonds on the d-carbon atom have also been achieved. 1,5-Transposition of the radical centers takes place from alkoxyl, aminyl and carbon radicals to a remote carbon atom. Relocation of the radical centers preferentially involves 1,5-transfer of a hydrogen atom, although migrations of some other groups are known. The reactions of the carbon radical generated by 1,5-relocation of the radical center are presented and their synthetic applications are reviewed.

Synthesis and Free Radical Scavenging Activity of New Hydroxybenzylidene Hydrazines

Directory of Open Access Journals (Sweden)

Frantisek Sersen

2017-05-01

Full Text Available Hydroxybenzylidene hydrazines exhibit a wide spectrum of biological activities. Here, we report synthesis and free radical scavenging activity of nine new N-(hydroxybenzylidene-N′-[2,6-dinitro-4-(trifluoromethyl]phenylhydrazines. The chemical structures of these compounds were confirmed by 1H-NMR, 13C-NMR, 19F-NMR, IR spectroscopy, LC-MS, and elemental analysis. The prepared compounds were tested for their activity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH, galvinoxyl radical (GOR, and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS radicals. The free radical scavenging activity expressed as SC50 values of these compounds varied in a wide range, from a strong to no radical scavenging effect. The most effective radical scavengers were hydroxybenzylidene hydrazines containing three hydroxyl groups in the benzylidene part of their molecules. The prepared compounds were also tested for their activity to inhibit photosynthetic electron transport in spinach chloroplasts. IC50 values of these compounds varied in wide range, from an intermediate to no inhibitory effect.

Comparing Positively and Negatively Charged Distonic Radical Ions in Phenylperoxyl Forming Reactions.

Science.gov (United States)

Williams, Peggy E; Marshall, David L; Poad, Berwyck L J; Narreddula, Venkateswara R; Kirk, Benjamin B; Trevitt, Adam J; Blanksby, Stephen J

2018-06-04

In the gas phase, arylperoxyl forming reactions play a significant role in low-temperature combustion and atmospheric processing of volatile organic compounds. We have previously demonstrated the application of charge-tagged phenyl radicals to explore the outcomes of these reactions using ion trap mass spectrometry. Here, we present a side-by-side comparison of rates and product distributions from the reaction of positively and negatively charge tagged phenyl radicals with dioxygen. The negatively charged distonic radical ions are found to react with significantly greater efficiency than their positively charged analogues. The product distributions of the anion reactions favor products of phenylperoxyl radical decomposition (e.g., phenoxyl radicals and cyclopentadienone), while the comparable fixed-charge cations yield the stabilized phenylperoxyl radical. Electronic structure calculations rationalize these differences as arising from the influence of the charged moiety on the energetics of rate-determining transition states and reaction intermediates within the phenylperoxyl reaction manifold and predict that this influence could extend to intra-molecular charge-radical separations of up to 14.5 Å. Experimental observations of reactions of the novel 4-(1-carboxylatoadamantyl)phenyl radical anion confirm that the influence of the charge on both rate and product distribution can be modulated by increasing the rigidly imposed separation between charge and radical sites. These findings provide a generalizable framework for predicting the influence of charged groups on polarizable radicals in gas phase distonic radical ions. Graphical Abstract.

Radiation-initiated free-radical fragmentation of biologically active glycerides

International Nuclear Information System (INIS)

Akhrem, A.A.; Kisel', M.A.; Shadyro, O.I.; Yurkova, I.L.

1993-01-01

Oxidation reactions of the free-radical type play a decisive role in the initial processes of radiation damage. The most suitable substrates for such reactions are lipids. Lipids are a basic structural element of biomembranes and are involved in the barrier function and biocatalytic activity of such membranes. Free-radical degradation of membrane lipids can lead to serious damage and ultimately to destruction of the living cell. A well-studied type of free-radical conversion of lipids is oxidation of polyunsaturated fatty acid residues, so-called peroxide oxidation of lipids. In this paper, using as examples dimyristoylphosphatidyl glycerol (DMPG), monoglycerides, and glycerophosphate, the authors investigated the possibility of free-radical degradation in compounds of a lipid nature containing the α,β-bifunctional group

Pertinent issues related to laparoscopic radical prostatectomy

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Sidney C. Abreu

2003-12-01

Full Text Available PURPOSE: We describe the critical steps of the laparoscopic radical prostatectomy (LRP technique and discuss how they impact upon the pertinent issues regarding prostate cancer surgery: blood loss, potency and continence. RESULTS: A major advantage of LRP is the reduced operative blood loss. The precise placement of the dorsal vein complex stitch associated with the tamponading effect of the CO2 pneumoperitoneum significantly decrease venous bleeding, which is the main source of blood loss during radical prostatectomy. At the Cleveland Clinic, the average blood loss of our first 100 patients was 322.5 ml, resulting in low transfusion rates. The continuous venous bleeding narrowed pelvic surgical field and poor visibility can adversely impact on nerve preservation during open radical prostatectomy. Laparoscopy, with its enhanced and magnified vision in a relatively bloodless field allows for excellent identification and handling of the neurovascular bundles. During open retropubic radical prostatectomy, the pubic bone may impair visibility and access to the urethral stump, and the surgeon must tie the knots relying on tactile sensation alone. Consequently, open prostatectomy is associated with a prolonged catheterization period of 2 - 3 weeks. Comparatively, during laparoscopic radical prostatectomy all sutures are meticulously placed and each is tied under complete visual control, resulting in a precise mucosa-to-mucosa approximation. CONCLUSION: The laparoscopic approach may represent a reliable less invasive alternative to the conventional open approach. Despite the encouraging preliminary anatomical and functional outcomes, prospective randomized comparative trials are required to critically evaluate the role of laparoscopy for this sophisticated and delicate operation.

Rapid Hydrogen Shift Reactions in Acyl Peroxy Radicals

DEFF Research Database (Denmark)

Knap, Hasse Christian; Jørgensen, Solvejg

2017-01-01

-shift with X = 6, 7, 8, or 9) in the hydroperoxy acyl peroxy radicals, this H-shift is a reversible reaction and it scrambles between two peroxides, hydroperoxy acyl peroxy and peroxy peroxoic acid radicals. The forward reaction rate constants of the 1,X-OOH H-shift reactions are estimated to be above 103 s–1...... with transition state theory corrected with Eckart quantum tunnelling correction. The ratio between the forward and reverse reaction rate constant of the 1,X-OOH H-shift reactions is around ∼105. Therefore, the equilibrium is pushed toward the production of peroxy peroxoic acid radicals. These very fast 1,X-OOH H......We have used quantum mechanical chemical calculations (CCSD(T)-F12a/cc-pVDZ-F12//M06-2X/aug-cc-pVTZ) to investigate the hydrogen shift (H-shift) reactions in acyl peroxy and hydroperoxy acyl peroxy radicals. We have focused on the H-shift reactions from a hydroperoxy group (OOH) (1,X-OOH H...

Engineering radical polymer electrodes for electrochemical energy storage

Science.gov (United States)

Nevers, Douglas R.; Brushett, Fikile R.; Wheeler, Dean R.

2017-06-01

In principle a wide range of organic materials can store energy in the form of reversible redox conversions of stable radicals. Such chemistry holds great promise for energy storage applications due to high theoretical capacities, high rate capabilities, intrinsic structural tunability, and the possibility of low-cost "green" syntheses from renewable sources. There have been steady improvements in the design of organic radical polymers, in which radicals are incorporated into the backbone and/or as pendant groups. This review highlights opportunities for improved redox molecule and polymer design along with the key challenges (e.g., transport phenomena, solubility, and reaction mechanisms) to transitioning known organic radicals into high-performance electrodes. Ultimately, organic-based batteries are still a nascent field with many open questions. Further advances in molecular design, electrode engineering, and device architecture will be required for these systems to reach their full potential and meet the diverse and increasing demands for energy storage.

J/{psi} production in {radical}(s)=7 TeV pp collisions

Energy Technology Data Exchange (ETDEWEB)

Kramer, Frederick

2012-07-01

In the first part of this work the inclusive cross section for J/{psi} production in inelastic {radical}(s) = 7 TeV pp collisions has been determined within vertical stroke y vertical stroke < 0.9 and in the decay channel J/{psi} {yields} e{sup +}e{sup -}. The result for the integrated value is: {sigma}{sub J/{psi}}(vertical stroke y vertical stroke < 0.9) = 10.7 {+-} 0.8 (stat.) {+-} 1.4 (syst.) {+-} 0.4 (lumi.) {mu}b. Together with the ALICE measurement in the {mu}{sup +}{mu}{sup -} decay channel at forward rapidities and data from other experiments this result fills the gap at mid-rapidity for a comprehensive measurement of the J/{psi} rapidity distribution. Furthermore, results of the differential analysis as a function of the J/{psi} transverse momentum were presented. Finally the data are shown together with various theoretical predictions representing the current status of the three most common theoretical approaches for the description of quarkonia production: the Color-Singlet Model, the Color-Evaporation Model and NRQCD.

Formation of radicals in coal pyrolysis examined by electron spin resonance

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Tong Chang

2017-09-01

Full Text Available Electron spin resonance (ESR spectroscopy is used to study materials with unpaired electrons, such as organic radicals and metal complexes. This method can also be used to follow radical reactions during pyrolysis of carbonaceous materials. However, the temperature dependence of ESR measurement should be considered. To enable reasonable comparisons, results measured at different temperatures must be converted. In this study, we investigated the behavior of free radicals in the process of coal pyrolysis using in situ and ex situ ESR. The ESR data were collected at both pyrolysis and room temperatures, and apparent differences were analyzed. The differences were diminished when our data were converted to the same measurement temperature level based on the Boltzmann distribution law. Furthermore, we investigated the effects of process conditions on the behavior of free radicals in the solid phase of coal. We found that temperature is the most important factor determining the formation and behavior of free radicals in the solid phase, followed by the residence time. Relatively active radicals were quenched by hydrogen-donor solvents to some degree, while stable radicals remained.

Fluorophore-based sensor for oxygen radicals in processing plasmas

International Nuclear Information System (INIS)

Choudhury, Faraz A.; Shohet, J. Leon; Sabat, Grzegorz; Sussman, Michael R.; Nishi, Yoshio

2015-01-01

A high concentration of radicals is present in many processing plasmas, which affects the processing conditions and the properties of materials exposed to the plasma. Determining the types and concentrations of free radicals present in the plasma is critical in order to determine their effects on the materials being processed. Current methods for detecting free radicals in a plasma require multiple expensive and bulky instruments, complex setups, and often, modifications to the plasma reactor. This work presents a simple technique that detects reactive-oxygen radicals incident on a surface from a plasma. The measurements are made using a fluorophore dye that is commonly used in biological and cellular systems for assay labeling in liquids. Using fluorometric analysis, it was found that the fluorophore reacts with oxygen radicals incident from the plasma, which is indicated by degradation of its fluorescence. As plasma power was increased, the quenching of the fluorescence significantly increased. Both immobilized and nonimmobilized fluorophore dyes were used and the results indicate that both states function effectively under vacuum conditions. The reaction mechanism is very similar to that of the liquid dye

Fluorophore-based sensor for oxygen radicals in processing plasmas

Energy Technology Data Exchange (ETDEWEB)

Choudhury, Faraz A.; Shohet, J. Leon, E-mail: shohet@engr.wisc.edu [Plasma Processing and Technology Laboratory and Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Sabat, Grzegorz; Sussman, Michael R. [Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Nishi, Yoshio [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

2015-11-15

A high concentration of radicals is present in many processing plasmas, which affects the processing conditions and the properties of materials exposed to the plasma. Determining the types and concentrations of free radicals present in the plasma is critical in order to determine their effects on the materials being processed. Current methods for detecting free radicals in a plasma require multiple expensive and bulky instruments, complex setups, and often, modifications to the plasma reactor. This work presents a simple technique that detects reactive-oxygen radicals incident on a surface from a plasma. The measurements are made using a fluorophore dye that is commonly used in biological and cellular systems for assay labeling in liquids. Using fluorometric analysis, it was found that the fluorophore reacts with oxygen radicals incident from the plasma, which is indicated by degradation of its fluorescence. As plasma power was increased, the quenching of the fluorescence significantly increased. Both immobilized and nonimmobilized fluorophore dyes were used and the results indicate that both states function effectively under vacuum conditions. The reaction mechanism is very similar to that of the liquid dye.

Radical Left in Albania and Kosovo: Differences and Similarities

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Këlliçi Klejd

2017-06-01

Full Text Available The main research question for this paper is: Are there radical left wing movements in Albania and Kosovo and what are their main traits? Through answering this question, we will explore the development (or lack thereof of radical left wing movements. With radical left we intend movements that reject the underlying socio-economic structure of contemporary capitalism and its values and practices without opposing democracy. Through a thorough desk research and several interviews with experts and activists both in Albania and Kosovo, we look at the two case Political Opportunity Structures to study the emergence, the strategies, success or failures of the radical left. In Albania the radical left has been in decline since 1992, with only a recent revival from 2009 on. In Kosovo, the Lëvizja Vetëvendojse! (Self-Determination Movement, a civil movement transformed in a party, has succeeded in imposing its left agenda. Both cases employ a new rhetoric unrelated to the past communist regimes thus changing the perspective of political debate in both countries.

X-band ESR study on evaluation of radicals induced in pasteurized pepper

International Nuclear Information System (INIS)

Matsuura, Masaaki; Ogawa, Satoko; Ukai, Mitsuko; Oowada, Shigeru

2007-01-01

The radical properties of pasteurized pepper were investigated by means of X-band ESR spectroscopy. Pasteurization process was done by irradiation or steam. There were three radicals in the specimens before and after pasteurization. Upon irradiation a new radical was found. ESR peak intensity of specimen before and after parturition with steam was almost same level. Peak intensity of radiated pepper showed almost 4 times as compare with that of non treated pepper. Radical activity of the specimens after pasteurization showed almost same value. We concluded that radicals were induced by irradiation. But the radical activity was not changed before and after pasteurization. (author)

Mechanism of protection of adenosine from sulphate radical anion ...

Indian Academy of Sciences (India)

Unknown

Keywords. Repair by caffeic acid; repair of adenosine radicals; oxidation by sulphate radical anions. ... known that hydroxycinnamic acids are natural anti- oxidants ... acid. 2. Experimental ..... ously and independently under kinetic conditions at.

Geoscientists and the Radical Middle

Science.gov (United States)

Tinker, S. W.

2015-12-01

Addressing the great challenges facing society requires industry, government, and academia to work together. I call this overlap space, where compromises are made and real solutions determined, the Radical Middle. Radical because it can appear at times as if the loudest and most publicly influential voices lie outside of the actual solution space, content to provoke but not problem-solve. One key area where geoscientists can play a lead role in the Radical Middle is in the overlap between energy, the environment, and the economy. Globally, fossil fuels still represent 85% of the aggregate energy mix. As existing conventional oil and natural-gas reservoir production continues to slowly decline, unconventional reservoirs, led today by shale and other more expensive resources, will represent a growing part of the oil and gas production mix. Many of these unconventional reservoirs require hydraulic fracturing. The positive economic impact of hydraulic fracturing and associated natural gas and oil production on the United States economy is well documented and undeniable. Yet there are environmental concerns about fracking, and some states and nations have imposed moratoria. This energy-environment-economy space is ideal for leadership from the geosciences. Another such overlap space is the potential for geoscience leadership in relations with China, whose economy and global presence continue to expand. Although China is building major hydropower and natural-gas power plants, as well as nuclear reactors, coal is still king—with the associated environmental impacts. Carbon sequestration—onshore in brine and to enhance oil recovery, as well as offshore—could prove viable. It is vital that educated and objective geoscientists from industry, government, and academia leave their corners and work together in the Radical Middle to educate the public and develop and deliver balanced, economically sensible energy and environmental strategies.

Radiation chemistry of aromatic dimer radical cations

International Nuclear Information System (INIS)

Okamoto, Kazumasa; Tagawa, Seiichi

2009-01-01

π-π Interactions of aromatic molecules are paid attention much in many fields, especially biology, chemistry, and applied physics, represented as protein, DNA, electron donor-accepter complexes, charge transfers, and self assembly molecules. Aromatic molecules including benzene rings are the simplest case to study the π-π interactions. To interpret the charge resonance (CR) structure in the dimer radical cations, spectroscopic and ESR methods have been carried out. The spectroscopic study on the dimer radical ion of molecules with two chromophores would be profitable to identify the electronic and configurational properties. In this article, dynamics of the dimer radical cation of benzenes, polystyrenes, and resist polymers is described on the basis of direct observation of CR band by the nanosecond pulse radiolysis and low temperature γ-radiolysis methods. (author)

Radical versus Social Constructivism: Dilemma, Dialogue, and Defense

Science.gov (United States)

Belbase, Shashidhar

2011-01-01

This paper aims to discuss epistemological and philosophical foundation of meaningful learning and teaching mathematics and science from the perspective of radical and social constructivism. I have reflected on my experiences of radical and social constructivism through dilemma, dialogue, and defense of my personal epistemology of learning. I went…

Radicals versus Moderates: A Critique of Gyekye's Moderate ...

African Journals Online (AJOL)

The communitarian conception of person is a widely accepted view in African thought. Kwame Gyekye thinks there is a distinction between what he calls radical communitarianism and his own version of moderate communitarianism. He is of the view that radical communitarianism is faced with insurmountable problems and ...

Characterization and DPPH Radical Scavenging Activity of Gallic ...

African Journals Online (AJOL)

Characterization and DPPH Radical Scavenging Activity of Gallic Acid-Lecithin Complex. C Liu, C Chen, H Ma, E Yuan, Q Li. Abstract. Purpose: To investigate the physicochemical properties and DPPH radical scavenging activity of gallic acid–lecithin complex. Methods: The complex of gallic acid with lecithin was prepared ...

Efectos radicales de un encuentro, lo contingente, lo inevitable/Radical effects of an encounter, the contingent, the inevitable

Directory of Open Access Journals (Sweden)

Alba Fernández

2010-03-01

Full Text Available A partir de la pregunta por la posibilidad del diálogo entre psicoanálisis y filosofía, los autores se proponen un recorrido por algunas de las cuestiones que dicha relación auspicia. Asumiendo la imposibilidad de homogeneidad de una filosofía y de un psicoanálisis, se problematiza entorno a lo aleatorio del encuentro posible, a la vez que se presume lo ineluctable del mismo. Tomando los discursos que de un campo y otro hacen referencia a la utopía, pero también a la posibilidad de esta conjunción con el extranjero, los autores subrayan la importancia del amor. El amor será el operador que propicie la radical singularidad de un encuentro, del cual se saldrá no beneficiado ni oprimido, tal vez más inseguro, más delicado, más quebradizo, pero lleno de esperanzas que aún no tienen nombre. From the question based on the possibility of the dialogue between psychoanalysis and philosophy, the authors have set out a route in which some of the questions of such relation foster. Assuming that the impossible homogeneity between a philosophy and a psychoanalysis will give problematic environment to the possible random encounter, in turn suppose the ineluctable of itself. Taking the speeches from one field and from another, both make reference to the utopia, but also to the possibility of this conjunction with the foreigner; could emphasize the importance of love according to authors. Love will be the conductor which will encourage the radical singularity of an encounter, from which not only there will not be no favored, but also no oppressed. However, it could be more unsecured, more delicate, more fragile, but full of hope that have no name yet.

EPR spectral investigation of radiation-induced radicals of gallic acid.

Science.gov (United States)

Tuner, Hasan

2017-11-01

In the present work, spectroscopic features of the radiation-induced radicals of gallic acid compounds were investigated using electron paramagnetic resonance (EPR) spectroscopy. While un-irradiated samples presented no EPR signal, irradiated samples exhibited an EPR spectrum consisting of an intense resonance line at the center and weak lines on both sides. Detailed microwave saturation investigations were carried out to determine the origin of the experimental EPR lines. It is concluded that the two side lines of the triplet satellite originate from forbidden "spin-flip" transitions. The spectroscopic and structural features of the radiation-induced radicals were determined using EPR spectrum fittings. The experimental EPR spectra of the two gallic acid compounds were consistent with the calculated EPR spectroscopic features of the proposed radicals. It is concluded that the most probable radicals are the cyclohexadienyl-type, [Formula: see text] radicals for both compounds.

Radical scavenging potentials of single and combinatorial herbal formulations in vitro

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Okey A. Ojiako

2016-04-01

Full Text Available Reactive oxygen and nitrogen species (RONS are involved in deleterious/beneficial biological processes. The present study sought to investigate the capacity of single and combinatorial herbal formulations of Acanthus montanus, Emilia coccinea, Hibiscus rosasinensis, and Asystasia gangetica to act as superoxide radicals (SOR, hydrogen peroxide (HP, nitric oxide radical (NOR, hydroxyl radical (HR, and 2,2-diphenyl-1-picrylhydrazyl (DPPH radical antagonists using in vitro models. The herbal extracts were single herbal formulations (SHfs, double herbal formulations (DHfs, triple herbal formulations (THfs, and a quadruple herbal formulation (QHf. The phytochemical composition and radical scavenging capacity index (SCI of the herbal formulations were measured using standard methods. The flavonoids were the most abundant phytochemicals present in the herbal extracts. The SCI50 defined the concentration (μg/mL of herbal formulation required to scavenge 50% of the investigated radicals. The SHfs, DHfs, THfs, and QHf SCI50 against the radicals followed the order HR > SOR > DPPH radical > HP > NOR. Although the various herbal formulations exhibited ambivalent antioxidant activities in terms of their radical scavenging capabilities, a broad survey of the results of the present study showed that combinatorial herbal formulations (DHfs, THfs, and QHf appeared to exhibit lower radical scavenging capacities than those of the SHfs in vitro.