Polimorfismo Val108/158Met en el gen dopaminérgico catecol-o-metil transferasa (COMT en una población mixta peruana y su importancia para los estudios neuropsiquiátricos

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Doris Huerta

2007-12-01

Full Text Available Introducción: El gen dopaminérgico catecol-o-metil transferasa (COMT, tiene un polimorfismo funcional Val108/158Met que da lugar a variantes de la enzima que cataliza la o-metilación de las catecolaminas activas, participando en el metabolismo de las drogas y neurotransmisores, como la L-dopa, norepinefrina, epinefrina y dopamina y, por consiguiente, puede asociarse a condiciones neuropsiquiátricas. Objetivos: Determinar las frecuencias genotípicas y alélicas del polimorfismo Val108/158Met del gen COMT en sujetos saludables de una población mixta peruana y establecer las implicancias para el estudio genético de enfermedades y otras condiciones neuropsiquiátricas. Diseño: Estudio descriptivo, observacional, transversal. Lugar: Centro de Investigación de Bioquímica y Nutrición ‘Alberto Guzmán Barrón’. Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Participantes: Ciento seis personas, hombres y mujeres, clínicamente saludables, sin enfermedades neurológicas ni mentales u otra patología similar, voluntarios con consentimiento informado, sin relación de parentesco, todos residentes en Lima, cuyas edades fluctuaban entre los 18 y 50 años. Intervenciones: Extracción del ADN genómico a partir de células de epitelio bucal, según metodología estándar. Amplificación mediante la PCR con primers específicos y digestión con la enzima de restricción NlaIII. Detección de fragmentos de restricción de longitud polimórfica (RFLP por electroforesis en gel de poliacrilamida al 6%, teñido con nitrato de plata. Principales medidas de resultados: Frecuencias genotípicas y alélicas del gen COMT en población mixta peruana. Resultados: Se encontró las frecuencias genotípicas Met/Met=0,0661, Val/Met=0,5094 y Val/Val=0,4245, siendo la distribución consistente con el equilibrio de Hardy-Weinberg (X² =3,0317, g.l.=1, p >0,05. Las frecuencias alélicas encontradas fueron alelo Val=0,68 y el alelo Met=0

Polimorfismo genético relacionado con la probabilidad de desarrollar asma ocupacional en trabajadores expuestos a isocianatos

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Gaetano Pepe Betancourt

2014-03-01

Full Text Available Introducción: El desarrollo tecnológico ha traído como consecuencia el uso de sustancias químicas potencialmente perjudiciales para la salud de los trabajadores. Particularmente el uso de isocianatos ha resultado en una mayor morbilidad de patología respiratoria, especialmente el asma. Considerando que no todos los trabajadores expuestos desarrollan la enfermedad se ha propuesto un modelo de interacción gen-medioambiental, el cual trata de explicar la predisposición genética que tienen algunos individuos a desarrollar asma ocupacional y otros no. Objetivo: Conocer la evidencia científica relacionada con el polimorfismo genético y la susceptibilidad que tienen los trabajadores expuestos a isocianatos a desarrollar asma ocupacional. Metodología: Se realizó una revisión sistemática mediante una búsqueda bibliográfica utilizando las bases de datos PubMedline, así como en los repositorios Dialnet y ELSEVIER. Se extrajeron los artículos relacionados al objetivo de esta revisión, no se aplicaron filtros de temporalidad, utilizándose los siguientes descriptores: MeSH Major Topic, MeSH Terms. El periodo de búsqueda fue desde el 20 de noviembre de 2013 y finalizó el 15 de diciembre de 2013. El nivel de evidencia se estableció de acuerdo a los criterios GRADE. Resultados: Se analizaron a texto completo 42 artículos, la evidencia científica se sustentó en 11 estudios de casos-controles. Dada la complejidad del polimorfismo genético asociado con la expresión fenotípica de la enfermedad, como limitación de los estudios, los autores coinciden que el tamaño muestral no es suficientemente grande, sin embargo después de ajustar los factores de confusión los artículos encontrados tuvieron un nivel de evidencia B de GRADE. Conclusión: La genética tiene una influencia significativa en el asma ocupacional inducida por isocianatos. El peso de la susceptibilidad genética y de la interacción gen-medioambiente aún no se han

Determinación de la variabilidad genética entre aislamientos de Rosellinia sp. Rosellinia bunodes y Rosellinia pepo mediante la técnica de amplificación aleatoria de polimorfismos de DNA (RAPD y análisis de los espaciadores de transcritos internos (ITSS

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Javier Andrés López Quintero

2004-07-01

bunodes en los dendrogramas tanto de RAPD como de ITS1. Sin embargo, el alto grado de polimorfismo (>80% observado en el análisis de RAPD para las tres especies, está correlacionado con el aumento progresivo de las enfermedades en los cultivos de café, papa y cacao, con la procedencia geográfica de las cepas y con la alta divergencia encontrada en otros miembros de la familia Xylariaceae en el trópico. Ya que las regiones rDNA-ITS muestran un alto nivel de polimorfismo interespecífico y múltiples copias en el genoma celular, son un buen candidato para el diseño de iniciadores especie-específicos. Por tanto, las secuencias de las regiones ITS1 e ITS2 permitieron el desarrollo de iniciadores de PCR específicos para detectar y diferenciar Rosellinia sp. de otras especies, constituyéndose en un sistema de diagnóstico del patógeno en suelo y material vegetal. Se sugieren iniciadores específicos para Rosellinia pepo y Rosellinia bunodes que serán probados en ensayos posteriores.

Polimorfismos del gen pfmdr1 en muestras clínicas de Plasmodium falciparum y su relación con la respuesta terapéutica a antipalúdicos y paludismo grave en Colombia

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Paula Montoya

2007-06-01

Conclusiones. Los polimorfismos 86Tir y 1246Tir en el gen pfmdr1 no son útiles como factores de predicción de falla terapéutica o paludismo grave en los municipios estudiados. Este estudio describe por primera vez la presencia del alelo 86Tir en cuatro muestras clínicas de Suramérica.

Polimorfismo en el gen COMT en una muestra de gestantes normales y con restricción del crecimiento intrauterino en un hospital de Lima

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José Pacheco-Romero

2013-04-01

Full Text Available Antecedentes: Los procesos fisiopatológicos que ocurren a nivel celular y molecular en la restricción de crecimiento intrauterino (RCIU son aún desconocidos. La catecol-O-metiltransferasa (COMT es una enzima de fase II que inactiva los catecol estrógenos al transferir un grupo metílico. Se conoce un polimorfismo funcional Val158 Met en el gen COMT como un marcador susceptible para diversas enfermedades maternoperinatales, existiendo estudios que sugieren que el alelo que codifica una COMT de baja actividad puede ser un marcador susceptible para RCIU. Por lo tanto, el estudio del polimorfismo COMT ofrece una nueva estrategia para la evaluación de marcadores genéticos que pueden ser utilizados para la detección de ciertas alteraciones asociadas al embarazo. Objetivos: Establecer la asociación entre el polimorfismo Val158Met catecol-O-metiltransferasa (COMT y la restricción de crecimiento intrauterino. Institución: Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Diseño: Estudio tipo relacional (asociativo, con diseño observacional, tipo caso-control (no experimental. Materiales: Muestra de sangre materna de parturientas. Métodos: Durante el año 2011, se obtuvo 81 muestras para genotipaje del gen COMT. De ellas, 26 (32,1% correspondieron a parturientas con RCIU (casos y 55 (67,9% a muestras de madres de hijos sin RCIU (controles. La distribución de los genotipos fue evaluada usando la prueba de chi cuadrado. Se comprobó la distribución proporcional de los genotipos en los grupos con RCIU y sin RCIU con la hipótesis nula de Hardy-Weinberg. Las madres participantes firmaron un consentimiento informado. Principales medidas de resultados: Asociación entre los genotipos COMT y la RCIU, y entre los alelos COMT Val/Met y la RCIU. Resultados: Las distribuciones de los genotipos en los grupos con RCIU y sin RCIU estuvieron de acuerdo a la hipótesis nula de Hardy-Weinberg. Al relacionar los genotipos COMT Val

Vascular endothelial growth factor gene polymorphisms in patients with colorectal cancer Polimorfismos del gen del factor de crecimiento vascular endotelial en pacientes con cáncer colorrectal

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M. Vidaurreta

2010-01-01

Full Text Available Background: angiogenesis plays an important role in tumor progression. The vascular endothelial growth factor (VEGF is an important regulator of angiogenesis. In the present study we evaluated single nucleotide polymorphisms (SNPs -2578C > A, -1154G > A, and +936C > T in the VEGF gene, and their prognostic value for patients operated on for colorectal cancer (CRC. Patients and method: VEGF polymorphisms have been analyzed in 177 patients who had undergone surgical resection at Hospital Clínico San Carlos. The analysis of these polymorphisms was performed with specific probes for each nucleotide in a multiplex reaction using real-time PCR. Results: we only found a statistically significant relationship for one of these three polymorphisms, +936C > T, with gender and tumor location; 10.7% of patients heterozygotes for this SNP had tumors located in proximal colon, 35.2% in distal segment and 54.1% in rectum (p = 0.03. Patients with the +936T/T genotype had 100% overall survival (OS. Conclusion: patients with a +936T/T genotype showed increased survival, therefore the +936C > T SNP could be a useful marker in the follow-up and clinical management of patients with colorectal cancer.Introducción: la angiogénesis juega un papel importante en la progresión de los tumores. El factor de crecimiento endotelial vascular (VEGF es un importante regulador de la angiogénesis. En este trabajo se han analizado los polimorfismos de único nucleó-tido (SNP -2578C > A, -1154G > A y +936C > T del gen VEGF en pacientes intervenidos de carcinoma colorrectal, así como su posible implicación pronóstica. Pacientes y método: el estudio de estos SNP se ha realizado en 177 pacientes intervenidos quirúrgicamente de carcinoma colorrectal (CCR en el Hospital Clínico San Carlos. El análisis de los polimorfismos se realizó con sondas específicas para cada nucleótido y se determinó mediante una reacción multiplex mediante real time PCR. Resultados: de los 3

Polimorfismo en el gen COMT en una muestra de gestantes normales y con restricción del crecimiento intrauterino en un hospital de Lima

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José Pacheco-Romero; Doris Huerta; Oscar Acosta; Santiago Cabrera

2013-01-01

Antecedentes: Los procesos fisiopatológicos que ocurren a nivel celular y molecular en la restricción de crecimiento intrauterino (RCIU) son aún desconocidos. La catecol-O-metiltransferasa (COMT) es una enzima de fase II que inactiva los catecol estrógenos al transferir un grupo metílico. Se conoce un polimorfismo funcional Val158 Met en el gen COMT como un marcador susceptible para diversas enfermedades maternoperinatales, existiendo estudios que sugieren que el alelo que codifica una COMT d...

Variabilidad genética de la respuesta inflamatoria: I. Polimorfismo -511 C/T en el gen IL1β en diferentes subpoblaciones peruanas

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Óscar Acosta

2012-07-01

Full Text Available El polimorfismo -511 citosina/timina (-511 C/T en la región promotora del gen interleuquina 1 beta (IL1β estα implicado en la producciσn diferencial de la citoquina y por tanto puede estar asociado a la respuesta inmuno-inflamatoria en obesidad, dislipidemias, cardiopatías, cáncer, infecciones, y el tratamiento con nutrientes y fármacos. Objetivos: Establecer la distribución de frecuencias de los genotipos y alelos del polimorfismo -511 C/T del gen IL1β en diferentes subpoblaciones peruanas. Diseño: Estudio descriptivo, observacional, transversal. Instituciones: Centro de Investigación de Bioquímica y Nutrición e Instituto de Medicina Tropical D.A. Carrión, Facultad de Medicina, UNMSM y Centro de Genética y Biología Molecular, Facultad de Medicina, USMP, Lima, Perú. Participantes: Pobladores peruanos. Intervenciones: Extracción de ADN genómico a partir de muestras sanguíneas o epitelio bucal según metodología estándar, de 168 individuos de 9 grupos subpoblacionales: 23 mestizos de Lima, 33 amazónicos (20 de Pucallpa y 13 de Amazonas y 112 andinos (12 de Ancash, 10 de Cajamarca, 18 de Huarochirí-Lima, 25 de Puno-Taquile, 25 de Puno-Uros y 22 de Puno-Anapia. Análisis del polimorfismo -511 C/T mediante la técnica de PCR/RFLP, con primers específicos y digestión con la enzima de restricción AvaI, detectándose los fragmentos por electroforesis en geles de agarosa al 2% y tinción con bromuro de etidio. Principales medidas de resultados: Frecuencias genotípicas y alélicas del gen IL1β. Resultados: Se encontró las siguientes frecuencias genotípicas CC=0,024; CT=0,369 y TT=0,607, consistentes con el equilibrio de Hardy-Weinberg; y las frecuencias alélicas fueron alelo C=0,208 y aleloT= 0,792. La frecuencia del alelo T, considerado el mutante, fue muy alta en los Uros de Puno (0.940 y más baja en los mestizos de Lima (0.609. La comparación de las frecuencias genotípicas (TT versus CT+CC y alélicas (T versus C

Influencia de polimorfismos genéticos, variables analíticas y ambientales en las concentraciones valle de terapia anti-TNF de pacientes con enfermedad inflamatoria intestinal

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Romero Cara, Patricia

2015-01-01

OBJETIVOS La terapia anti-TNF-alfa está indicada en el tratamiento de las enfermedades inflamatorias crónicas. Cuando la respuesta es inadecuada se recomienda la intensificación de la dosis. Sin embargo, ni las razones para esta recomendación, ni los múltiples mecanismos implicados son bien conocidos. Nuestro objetivo principal es investigar si polimorfismos en los genes FCGRT, FCGR2A y FCGR3A (relacionados con el metabolismo y eliminación de inmunoglobulinas) ejercen una influencia en la ...

Polimorfismos en la longitud de fragmentos amplificados (AFLP´s) a partir de muestras de sangre almacenadas en tarjetas FTA® para la especie Cavia porcellus Lin. (Rodentia: Caviidae)

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Burgos-Paz, William; Rosero-Galindo, Carol; Cárdenas-Henao, Heiber; Solarte-Portilla, Carlos

2007-01-01

Una manera eficaz de establecer el grado de variabilidad entre y dentro de poblaciones, es a través del análisis de polimorfismos de ADN con marcadores moleculares como los AFLP`s. En este artículo se presenta una metodología que combina la utilización de tarjetas de FTA® (Whatman Bioscience, Cambridge) para colección y conservación de muestras de sangre, con los procedimientos de extracción de ADN y obtención de marcadores AFLP´s, aspectos sobre los cuales no existen antecedentes para la esp...

Polimorfismos del gen ob en bovinos de raza holstein en la Comarca Lagunera, México

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Sarai S. Mendoza-Retana

2017-01-01

Full Text Available La Comarca Lagunera es la cuenca lechera más importante de México. En la actualidad se están utilizando diversas técnicas que permiten evaluar genéticamente el animal a una edad temprana, permitiendo seleccionar futuros reproductores con características deseables. Entre los genes relacionados con la producción de leche, se encuentran el gen Ob también llamado gen Leptina el cual actúa sobre el sistema nervioso central y tejidos periféricos jugando un papel muy importante en la modulación regulación del apetito, ganancia de peso vivo, incremento del metabolismo energético y el anabolismo muscular. Este trabajo se realizó para determinar el polimorfismo de longitud del fragmento de restricción ACI I de gen leptina en el exón 2 y correlacionarlo con los parámetros de producción y calidad de leche. Se recolectaron 100 muestra de sangre de vacas en producción del establo “Lácteos Florida” de Francisco I. Madero municipio de Coahuila, México con tres esta tus de producción: altas, medias y bajas La extracción de ADN se realizó por el método modificado de Salting - Out. Se realizó PCR del gen leptina originando un fragmento de 272 bp de longitud y se realizó PCR - RFLP con la enzima de restricción ACI I y secue nciación, correlacionando los genotipos TT, CT Y CC con tres estatus de producción de leche: altas, medias, bajas. El análisis estadístico indicó que las vacas portadoras del genotipo homocigoto (TT tienen un efecto significativo (P<0.01 con respecto a l as características de producción y calidad de leche ya que tuvieron un mayor consumo de alimento, ganancia de peso, además de una elevada producción de leche en comparación a los genotipos heterocigoto (CT y homocigoto (CC. Los resultados obtenidos muest ran que l a identificación molecular de polimorfismos del gen Ob puede usarse como herramienta de selección genética en bovinos de raza Holstein.

Composición de Ácidos Grasos (MUFA y CLA) en Tejido Muscular de Bovino Relacionado con la Presencia del Polimorfismo g.878TC en el Gen SCD

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Inostroza, K; Larama, G; Sepúlveda, N

2012-01-01

El tejido muscular de muchos animales domésticos es fuente de proteínas, grasa y minerales para los seres humanos y está compuesto por una serie de estructuras que le otorgan propiedades nutricionales y bioquímicas. En los ultimos años se ha identificado un polimorfismo de único nucleótido (SNP) en el gen SCD (g.878TC), que influye sobre la composición de ácidos grasos en los bovinos. El objetivo de este estudio fue determinar la presencia del SNP g.878TC en músculo Longissimus dorsi de bovin...

Frequency of MYO9B polymorphisms in celiac patients and controls Frecuencia de polimorfismos del gen MYO9B en pacientes celiacos y en sujetos controles

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Tamara Loeff

2012-12-01

Full Text Available Introduction: the MYO9B gene contributes to the maintenance of the intestinal barrier and it has been postulated as a risk factor of celiac disease (CD. The objective of this study was to compare the frequency and association rs2305764, rs2305767and rs1457092 MYO09B polymorphisms in pediatric CD patients from Chile and Argentina. Patients and methods: the study was made in 104 CD pediatric patients (Chilean and Argentineans and 104 controls subjects. MYO9B gene polymorphisms were analyzed by Taqman allelic probes. We evaluated the Hardy-Weinberg equilibrium by means of Chi-square and compared the haplotypes distribution using Fisher test. Results: SNPs rs2305767 and rs1457092 were associated with celiac disease (CD; TT genotype in rs2305767 would be a protective factor (p Introducción: el gen miosina IX B (MYO9B participa en el mantenimiento de la barrera intestinal y se postula que puede aportar riesgo para desarrollar enfermedad celiaca (EC. El objetivo de este estudio fue comparar la frecuencia y la asociación de los polimorfismos rs 2305764, rs 2305767 y rs 1457092 del gen MYO9B en pacientes pediátricos con EC procedentes de Chile y Argentina. Pacientes y métodos: el estudio se realizó en 104 pacientes pediátricos con EC (chilenos y argentinos y en 104 sujetos controles. El análisis de los polimorfismos del gen MYO9B se realizó mediante ensayos Taqman de discriminación alélica. Se evalúo equilibrio de Hardy-Weinberg mediante Chi-cuadrado y comparación de haplotipos según prueba de Fisher. Resultados: los polimorfismos de un solo nucleótido (SNPs rs2305767 y rs1457092 mostraron asociación con la EC. El genotipo TT del rs2305767 sería un factor protector (p < 0,0001, OR = 0,19 IC 0,1-0,4 mientras que el genotipo CT sería un factor de riesgo (p < 0,0001, OR = 4,9 IC 2,2-11,3. En el rs1457092, el genotipo CC resultó también un factor protector frente a esta enfermedad (p < 0,0001, OR = 0,07 IC 0,0-0,3. Conclusión: nuestros

Polimorfismos en los genes CYP11α y CYP17 y etiología del hiperandrogenismo en pacientes con poliquistosis ovárica Polymorphism in CYP11alpha and CYP17 genes and the etiology of hyperandrogenism in patients with polycystic ovary syndrome

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María S. Pérez

2008-04-01

Full Text Available El síndrome de poliquistosis ovárica (PCOS es un desorden endocrino-metabólico de naturaleza multifactorial, con una marcada predisposición genética, que afecta al 6% de las mujeres en edad reproductiva. Se caracteriza por la presencia de hiperandrogenismo, oligo-anovulación y ovarios poliquísticos. Entre los genes candidatos se encuentran aquellos que codifican para enzimas que actúan en la síntesis de andrógenos. Dos de los genes candidatos son el CYP17 y el CYP11alfa que codifican para la 17alfa hidroxilasa (P45017alfa y para el P450scc (colesterol side chain cleavage respectivamente. Los polimorfismos en estos genes están asociados al desarrollo del fenotipo hiperandrogénico. Nuestro objetivo fue analizar las frecuencias alélicas de los polimorfismos de los dos genes mencionados en población con PCOS, compararla con población normal y analizar la relación de cada variante alélica con el fenotipo hiperandrogénico correspondiente. Se analizaron 65 pacientes y 58 controles sanos en los que se determinaron niveles de testosterona y frecuencia de polimorfismos en los genes mencionados. Se observó una diferencia estadísticamente significativa cuando se asoció el grupo de mayor nivel de androgenemia con la presencia del genotipo A2/A2 del gen CYP17, y se hallaron mayores niveles de andrógenos circulantes en las pacientes con PCOS portadoras del alelo 216- del gen CYP11alfa. Nuestros resultados sugieren que ambos alelos juegan un rol menor en el desarrollo de PCOS y podrían ser considerados como potenciales marcadores de riesgo genético para el desarrollo del fenotipo hiperandrogénico.The polycystic ovary syndrome (PCOS is a heterogeneous multifactorial endocrine metabolic disorder with genetic predisposition affecting 6% of women in the reproductive age. This syndrome is characterized by the presence of oligo-anovulation, hyperandrogenism and polycystic ovaries. Several genes have been postulated as responsible for the

Germline TP53 mutations and single nucleotide polymorphisms in children Mutaciones y polimorfismos de un único nucleótido del gen TP53 en línea germinal en niños

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Pamela Valva

2009-02-01

Full Text Available Mutations in the gene TP53, which codifies the tumor suppressor protein p53, are found in about 50% of tumors. These mutations can occur not only at somatic level, but also in germline. Pediatric cancer patients, mostly with additional family history of malignancy, should be considered as potential TP53 germline mutation carriers. Germline TP53 mutations and polymorphisms have been widely studied to determine their relation with different tumors' pathogenesis. Our aim was to analyze the occurrence frequency of germline TP53 mutations and polymorphisms and to relate these to tumor development in a pediatric series. Peripheral blood mononuclear cell samples from 26 children with solid tumors [PST] and 21 pediatric healthy donors [HD] were analyzed for germline mutations and polymorphisms in TP53 gene spanning from exon 5 to 8 including introns 5 and 7. These PCR amplified fragments were sequenced to determine variations. A heterozygous mutation at codon 245 was found in 1/26 PST and 0/21 HD. Comparative polymorphisms distribution, at position 14181 and 14201(intron 7, between HD and PST revealed a trend of association (p= 0.07 with cancer risk. HD group disclosed a similar polymorphism distribution as published data for Caucasian and Central/South American populations. This is the first study about TP53 variant frequency and distribution in healthy individuals and cancer patients in Argentina.El gen que codifica para la proteína supresora de tumor p53 (TP53 se encuentra mutado en aproximadamente el 50% de los tumores. Estas mutaciones pueden presentarse como somáticas o en línea germinal. Los niños con tumores, sobre todo aquellos con historia familiar de enfermedad oncológica, deben considerarse potenciales portadores de mutaciones en línea germinal. Las mutaciones de TP53 y los polimorfismos son estudiados para determinar su relación con la patogénesis de diferentes tumores. El objetivo del trabajo fue analizar la frecuencia de

Síndrome de Turner e polimorfismo genético: uma revisão sistemática

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Alessandra Bernadete Trovó de Marqui

2015-09-01

Full Text Available ResumoObjetivo:Apresentar os principais resultados dos estudos que investigaram polimorfismos genéticos em síndrome de Turner, bem como sua associação com alguns sinais clínicos e etiologia desse distúrbio cromossômico.Fontes de dados:Revisão bibliográfica feita no PubMed, sem limite de período, com os seguintes termos: Turner syndrome and genetic polymorphism. Foram identificados 116 artigos e, de acordo com os critérios de inclusão e exclusão, 17 foram selecionados para leitura.Síntese dos dados:Os polimorfismos investigados em pacientes com síndrome de Turner estavam relacionados com déficit de crescimento, que causou baixa estatura, densidade mineral óssea baixa, autoimunidade e anomalias cardíacas, que podem estar presentes com frequências significativas nas pacientes. Também foi verificado o papel dos polimorfismos de único nucleotídeo (SNPs na etiologia da síndrome de Turner, ou seja, na não disjunção cromossômica.Conclusões:Os polimorfismos genéticos parecem estar associados à síndrome de Turner. Entretanto, por conta dos poucos estudos publicados e dos achados contraditórios, pesquisas em diferentes populações são necessárias para esclarecer o papel dessas variantes genéticas para os sinais clínicos e a etiologia do distúrbio cromossômico.

Diagnóstico genético del polimorfismo en citocromo P450 mediante ensayo de PCR múltiplex (Práctica en laboratorio virtual Cibertorio)

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Herráez, Angel

2017-01-01

Guión de trabajo para el laboratorio virtual «Cibertorio» en Biomodel.UAH.es Se habla de diversidad genética de los individuos como el resultado de que, en diversas regiones del genoma, unas personas tenemos secuencias de nucleótidos que nos diferencian de otras; esto se denomina polimorfismo genético. Cuando estas regiones polimórficas corresponden a zonas codificantes de un producto, existen consecuencias funcionales. La superfamilia enzimática citocromo P450 juega un papel crucial ...

Impacto do polimorfismo genetico da enzima conversora da angiotensina no remodelamento cardiaco

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Felipe Neves de Albuquerque

2014-01-01

Full Text Available Fundamento: O papel dos polimorfismos genéticos da enzima de conversão da angiotensina na insuficiência cardíaca, como preditor de desfechos ecocardiográficos, ainda não está estabelecido. é necessário identificar o perfil local para observar o impacto desses genótipos na população brasileira, sendo inédito o estudo da insuficiência cardíaca de etiologia exclusivamente não isquêmica em seguimento mais longo que 5 anos. Objetivo: Determinar a distribuição das variantes do polimorfismo genético da enzima de conversão da angiotensina e sua relação com a evolução ecocardiográfica de pacientes com insuficiência cardíaca de etiologia não isquêmica. Métodos: Análise secundária de prontuários de 111 pacientes e identificação das variantes do polimorfismo genético da enzima de conversão da angiotensina, classificadas como DD (Deleção/Deleção, DI (Deleção/Inserção ou II (Inserção/Inserção. Resultados: As médias da coorte foram: seguimento de 64,9 meses, idade de 59,5 anos, 60,4% eram homens, 51,4% eram brancos, 98,2% faziam uso de betabloqueadores e 89,2% de inibidores da enzima de conversão da angiotensina ou de bloqueador do receptor da angiotensina. A distribuição do polimorfismo genético da enzima de conversão da angiotensina foi: 51,4% de DD; 44,1% de DI; e 4,5% de II. Não se observou nenhuma diferença das características clínicas ou de tratamento entre os grupos. O diâmetro sistólico do ventrículo esquerdo final foi a única variável ecocardiográfica isolada significativamente diferente entre os polimorfismos genéticos da enzima de conversão da angiotensina: 59,2 ± 1,8 para DD versus 52,3 ± 1,9 para DI versus 59,2 ± 5,2 para II (p = 0,029. No seguimento ecocardiográfico, todas as variáveis (diferença entre a fração de ejeção do ventrículo esquerdo da última e da primeira consulta; diferença entre o diâmetro sistólico do ventrículo esquerdo da última e da primeira

Polimorfismos genéticos associados à hipertensão arterial sistêmica - doi: 10.5102/ucs.v6i1.464

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Luzitano Brandão Ferreira

2008-12-01

Full Text Available A hipertensão arterial sistêmica (HAS é uma doença poligênica e multifatorial que se constitui um grave problema de saúde publica, acometendo somente no Brasil, 15 milhões de pessoas. Ela está intimamente relacionada a diversas doenças cardiovasculares e renais, o que aumenta muito a sua morbmortalidade. Nos últimos anos vários estudos têm demonstrado a associação da HAS e suas complicações com diversos polimorfismos genéticos. O objetivo do presente estudo foi o de realizar uma revisão dos principais polimorfismos genéticos associados a HAS e suas complicações, especialmente cardiovasculares. Dentre os polimorfismos associados a HAS destacam-se os dos genes da enzima de conversão da angiotensina (ECA, haptoglobina, angiotensinogênio e angiotensina II. O conhecimento destes polimorfismos poderá, em breve, ser utilizado em larga escala na prática clínica para diagnóstico, acompanhamento e prognóstico de pacientes com HAS e suas complicações.

Maternal MTHFR polymorphisms and risk of spontaneous abortion Polimorfismos maternos MTHFR y riesgo de aborto espontáneo

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María del Rosario Rodríguez-Guillén

2009-02-01

Full Text Available OBJECTIVE: To asses the association between intake of folate and B vitamins and the incidence of spontaneous abortion (SA according to the maternal methylenetetrahydrofolate reductase (MTHFR polymorphisms (677 C>T and 1298 A>C. MATERIAL AND METHODS: We conducted a nested case-control study within a perinatal cohort of women recruited in the state of Morelos, Mexico. Twenty-three women with SA were compared to 74 women whose pregnancy survived beyond week 20th. Intake of folate and B vitamins respectively, was estimated using a validated food frequency questionnaire. Maternal MTHFR polymorphisms were determined by PCR-RFLP and serum homocysteine levels by HPLC. RESULTS: Carriers of MTHFR 677TT and 1298AC genotypes respectively showed an increased risk of SA (OR 677TT vs. CC/CT=5.0; 95% CI: 1.2, 20.9 and OR 1298 AC vs. AA=5.5; 95% CI: 1.1, 26.6. CONCLUSIONS: Our results support the role of MTHFR polymorphisms as a risk factor for SA, regardless of dietary intake of B vitamins.OBJETIVO: Evaluar la asociación entre aborto espontáneo (AE y el consumo dietético de vitaminas B en mujeres mexicanas portadoras de los polimorfismos de la metilentetrahidrofolato reductasa (MTHFR (677 C>T y 1298 A>C. MATERIAL Y MÉTODOS: Mediante un diseño de casos y controles anidados en una cohorte, se comparó la ingesta dietética materna de vitaminas B y folato, los polimorfismos maternos de la MTHFR y la concentración sérica de homocisteina de 23 casos de AE ( 20 semanas. RESULTADOS: Las portadoras de los genotipos MTHFR 677TT y 1298AC presentaron un incremento significativo en el riesgo de AE (RM 677TT vs. CC/CT=5.0; IC 95%: 1.2, 20.9 RM 1298 AC vs. AA=5.5; IC95%: 1.1, 26.6, respectivamente. CONCLUSIONES: Nuestros resultados apoyan el papel de la mutación de la MTHFR como posible factor de riesgo para el AE, independientemente del consumo de vitaminas B.

Efecto del polimorfismo del receptor ? 2 adrenérgico sobre la respuesta antihipertensiva en pacientes con hipertensión esencial

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Juan McEwen

2004-02-01

Full Text Available La hipertensión arterial esencial (HTE es uno de los principales factores de riesgo cardiovascular y generador indirecto de la enfermedad coronaria, la mayor causa de muertes en Colombia y el mundo [1].
El Sistema Nervioso Simpático (SNS modifica la resistencia
arterial periférica a través del receptor ? 2 adrenérgico,  generando señales intracelulares que regulan la relajación del
músculo liso vascular. Este receptor experimenta un proceso
denominado desensibilización, es decir, cuando es activado por
un agonista por tiempo prolongado, la respuesta no será de la
misma intensidad a la inicial. La desensibilización del receptor
? 2 parece estar determinada por la estructura de aminoácidos
polimórficos: Arginina 16 Glicina y Ácido glutámico 27 Glutamina
amino terminales. Estas variantes son codificadas por polimorfismos de un solo nucleótido (SNP 46 y 79. La función
de estos polimorfismos y su efecto en la función vascular es
controversial. Evidencias clínica e in vitro sugieren que la Glicina
16 se desensibiliza mas rápido que la Arginina; igualmente, el
Ácido glutámico 27 facilita la desensibilización versus
glutamina[2].

Actividad de la proteína transportadora de ésteres de colesterol. Polimorfismos del gen en pacientes colombianos con enfermedad coronaria Activity of cholesteryl ester transfer protein. Gene polymorphism in colombian patients with coronary artery disease

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Alejandra M Giraldo

2012-08-01

Full Text Available Introducción: la literatura relaciona la actividad de la proteína transportadora de ésteres de colesterol (CETP con enfermedad coronaria, por reducir el colesterol en las lipoproteínas de alta densidad. Adicionalmente, estudios recientes han identificado variaciones en el gen de la CETP, aunque el papel funcional de algunas de estas variantes sobre la actividad enzimática y la enfermedad coronaria, es desconocido. Objetivos: examinar la asociación de los polimorfismos TaqIB, MspI y RsaI del gen de la CETP y la actividad de la enzima con enfermedad coronaria. Métodos: se evaluó la asociación entre la actividad de la enzima y los polimorfismos TaqIB, MspI y RsaI, en pacientes con obstrucción coronaria documentada por angiografía. Resultados: la angiografía permitió clasificar a los pacientes en dos grupos: uno (213 individuos con obstrucción coronaria no significativa (OC 50%. La edad fue significantemente mayor en el último grupo en comparación con el primero. La actividad de la CETP fue 95,8 y 94,7 pmol/μL.h, para los grupos OC 50%, respectivamente. Solo se encontró diferencia significativa entre los alelos M1 y M2 en la población general. Conclusión: no se halló asociación entre la actividad de la CETP, los polimorfismos TaqBI, MspI, Rsal y la obstrucción coronaria. En este trabajo se describen por primera vez los niveles de CETP en los polimorfismos TaqIB, MspI, Rsal para un grupo de pacientes colombianos. Se debe refinar la descripción del evento coronario, el contexto metabólico de los pacientes y el estudio de haplotipos para encontrar relaciones con enfermedad coronaria.Introduction: literature links the activity of cholesteryl ester transfer protein (CETP with coronary heart disease by lowering cholesterol in high density lipoproteins. Additionally, recent studies have identified variations in the CETP gene, although the functional role of some of these variants on enzyme activity and coronary heart disease is

RELACIÓN DE LOS NIVELES SÉRICOS DE LÍPIDOS Y LIPOPROTEÍNAS CON EL POLIMORFISMO ε 2, ε 3 Y ε 4 DEL GEN DE LA APOLIPOPROTEÍNA E, EN INDIVIDUOS CON DIABETES MELLITUS TIPO 2 Y EL RIESGO CARDIOVASCULAR

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N. Coiza-Vargas

2005-12-01

Full Text Available Este trabajo describe la respuesta del perfil lipídico según el genotipo de la apolipoproteína E en personas con diabetes mellitus tipo 2 y la presencia o no de riesgo cardiovascular, por medio de la revisión sistemática de artículos científicos publicados entre 1990 y 2003. Seis estudios cumplieron con los criterios de inclusión y fueron seleccionados para realizar el trabajo de investigación.Inicialmente se realizó una descripción de características generales de los estudios y se utilizó la prueba estadística Chi - cuadrado para determinar diferencias entre grupos. Se encontró que el 66.6% de los artículos fueron realizados en Europa, el promedio de personas de los estudios fue de 473 y el promedio de edad estuvo en los 58 años.La distribución del genotipo E 3/3 (78.2%, fue la de mayor prevalencia en los diferentes grupos de diabéticos, seguido de E 4/3 en 12.8% y E 3/2 con un 8.7%. Las fracciones lipídicas más elevadas en los estudios fueron las de colesterol total, colesterol LDL y triglicéridos. Se observó que el polimorfismo de la apo E influye sobre el perfil lipídico, y por tanto, en el desarrollo de la enfermedad cardiovascular en los sujetos con DM tipo 2.

Polimorfismo inserción/deleción del gen de la enzima convertidora de angiontensina y enfermedad coronaria en la población de Montería, Córdoba

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Manolo I Jaramillo

2013-09-01

Full Text Available Antecedentes y objetivo: el polimorfismo inserción/deleción del gen de la enzima convertidora de angiotensina, ha sido identificado como un potente factor de riesgo de enfermedad coronaria. Para la población de Montería se desconocen las frecuencias con las que se expresan los alelos de este gen y el carácter de su interacción con condiciones de riesgo cardiovascular. El objetivo de este trabajo fue determinar, para dicha población, la asociación de este polimorfismo y el riesgo de sufrir enfermedad coronaria. Método: se llevó a cabo un estudio retrospectivo con 70 casos y 70 controles; como casos se consideraron pacientes con padecimientos coronarios confirmados por electrocardiograma, remitidos a la Organización Cardiodiagnóstico de Córdoba, y como controles individuos voluntarios sin antecedentes cardiovasculares y sin relación filial. El ADN requerido se extrajo a partir de sangre periférica. La caracterización del polimorfismo se hizo mediante reacción en cadena de la polimerasa. Resultados: la distribución de genotipos de la enzima convertidora de angiotensina en pacientes casos no fue significativamente diferente a la estimada en pacientes controles (X2=3.687, p=0,1583. El genotipo más frecuente en la población fue ID (40,72%. En el grupo casos, el genotipo II fue más frecuente que el genotipo DD comparado con el grupo control (p<0,05. El modelo de regresión logística múltiple ajustado, indicó no significancia del genotipo DD como factor de riesgo coronario (razón de disparidad = 0,51 IC95% = 0,25 – 1,06. Conclusión: el polimorfismo I/D del gen de la enzima convertidora de angiotensina no mostró ser un factor de riesgo significativo para enfermedad coronaria en la población de Montería.

Relación del polimorfismo C-514T del gen de la lipasa hepática con indicadores nutricionales y lipoproteínas en una muestra poblacional peruana: una perspectiva nutrigenética

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Doris Huerta

2008-12-01

Full Text Available Introducción: Las enfermedades cardiovasculares son una de las principales causas de muerte en todo el mundo. El promotor del gen de la lipasa hepática presenta un polimorfismo funcional C-514T que se relaciona con la actividad de la enzima, la variación de los niveles de lipoproteínas y un posible riesgo para desarrollar enfermedades cardiovasculares. Objetivos: Establecer la relación del polimorfismo C-514T del promotor del gen de la lipasa hepática con indicadores nutricionales y los niveles de lipoproteínas plasmáticas en una muestra de peruanos saludables. Diseño: Estudio descriptivo, transversal, asociativo. Lugar: Centro de Investigación de Bioquímica y Nutrición Alberto Guzmán Barrón, Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Participantes: Noventiuna personas sanas de ambos sexos, cuyas edades fluctuaban entre 18 y 58 años, voluntarios con consentimiento informado. Intervenciones: Extracción del ADN genómico a partir de muestras sanguíneas según metodología estándar. Toma de medidas antropométricas, estableciéndose los indicadores nutricionales, determinación del perfil lipídico por el método enzimático. Análisis del polimorfismo C-514T mediante la técnica de PCR/RFLP, con primers específicos y digestión con la enzima de restricción NlaIII, detectándose los fragmentos de RFLP por electroforesis en gel de poliacrilamida (PAGE y tinción con nitrato de plata. Principales medidas de resultados: Frecuencias genotípicas y alélicas del gen de la lipasa hepática y relación con parámetros lipídicos y nutricionales. Resultados: Se encontró las frecuencias genotípicas CC=0,143; CT=0,593 y TT = 0,264, siendo la distribución consistente con el equilibrio de Hardy-Weinberg (X2 =3,8024, g.l.=1, p = 0,086. Las frecuencias alélicas fueron alelo C = 0,4395 y el alelo T = 0,5605. Los niveles de colesterol, HDLc, LDLc, TG y los promedios de pliegue subcutáneo, el IMC y el porcentaje de

Influência do polimorfismo I/D do gene da eca na HPE de jovens normotensos

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Manuella de Oliveira Fernandes

2015-08-01

Full Text Available INTRODUÇÃO: A hipotensão pós-exercício (HPE é considerada uma estratégia não farmacológica adotada para redução da pressão arterial (PA. Ademais, sabe-se que a presença de alguns polimorfismos genéticos influencia a resposta pressórica, como o I/D do gene da enzima conversora da angiotensina (ECA. Objetivo: Analisar a influência do polimorfismo I/D da ECA sobre a HPE após três diferentes intensidades de exercício em jovens normotensos e fisicamente ativos.MÉTODOS: Vinte e seis jovens saudáveis (DD = 11; ID/II = 15 realizaram uma sessão máxima de 1.600 metros, na pista de atletismo e outras três sessões experimentais (Sessão Moderada: 6% abaixo do limiar anaeróbio, Sessão Intensa: 6% acima do limiar anaeróbio e Sessão de Controle, com aferições prévias da PA, por 20 minutos e posteriores ao exercício por 60 minutos.RESULTADOS: Observou-se que o exercício moderado ocasionou HPE independentemente do grupo genotípico, sendo mais evidente para a pressão arterial sistólica nos momentos 45 minutos e 60 minutos (p ≤ 0,05. Verificou-se também que a característica gênica exerceu influência sobre a área abaixo da curva pressórica (p ≤ 0,005 sobre a pressão arterial diastólica, formada 1 hora após o exercício.CONCLUSÃO: Conclui-se que o exercício moderado ocasiona HPE em jovens normotensos e fisicamente ativos, independentemente do polimorfismo I/D no gene da ECA, sendo que esse polimorfismo exerce influência sobre a hipotensão diastólica, e os indivíduos portadores do alelo I apresentam maior decaimento da PA diastólica (PAD.

Associação entre polimorfismos genéticos e transtorno bipolar

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Verônica de Medeiros Alves

2012-01-01

Full Text Available Transtorno bipolar (TB é uma doença comum que afeta aproximadamente 1% da população. Apresenta características crônicas e agudas graves, com índices de remissão de baixa e alta prevalência de comorbidades clínicas e psiquiátricas. O objetivo do presente artigo é sintetizar dados de vários artigos que investigaram polimorfismos genéticos associados com TB. Dentre os 129 artigos selecionados, identificaram-se 79 (85,87% genes associados com TB. Essa análise identificou cinco genes que são os mais citados na literatura: CANAC1C, DAOA, TPH2, ANK3 e DISC1. Dos 92 genes identificados nesses artigos, 33 (35,87% não mostraram associação com TB. Essa análise mostrou que, apesar dos avanços recentes com relação ao papel do polimorfismo genético na predisposição para TB, mais pesquisas ainda são necessárias para elucidar sua influência sobre esse transtorno.

Overview of advanced technologies for stabilization of 238Pu-contaminated waste

International Nuclear Information System (INIS)

Ramsey, K.B.; Foltyn, E.M.; Heslop, J.M.

1998-02-01

This paper presents an overview of potential technologies for stabilization of 238 Pu-contaminated waste. Los Alamos National Laboratory (LANL) has processed 238 PuO 2 fuel into heat sources for space and terrestrial uses for the past several decades. The 88-year half-life of 238 Pu and thermal power of approximately 0.6 watts/gram make this isotope ideal for missions requiring many years of dependable service in inaccessible locations. However, the same characteristic which makes 238 Pu attractive for heat source applications, the high Curie content (17 Ci/gram versus 0.06 Ci/gram for 239 Pu ), makes disposal of 238 Pu-contaminated waste difficult. Specifically, the thermal load limit on drums destined for transport to the Waste Isolation Pilot Plant (WIPP), 0.23 gram per drum for combustible waste, is impossible to meet for nearly all 238 Pu-contaminated glovebox waste. Use of advanced waste treatment technologies including Molten Salt Oxidation (MSO) and aqueous chemical separation will eliminate the combustible matrix from 238 Pu-contaminated waste and recover kilogram quantities of 238 PuO 2 from the waste stream. A conceptual design of these advanced waste treatment technologies will be presented

Mechanical properties of 238PuO2

International Nuclear Information System (INIS)

Petrovic, J.J.; Hecker, S.S.; Land, C.C.; Rohr, D.L.

1977-04-01

The mechanical properties of 238 PuO 2 have been examined in the Los Alamos Scientific Laboratory mechanical test facility built to handle α-radioactive materials. Compression tests were conducted as a function of temperature, strain rate, grain size, density, and storage time. At temperatures less than or equal to 1400 0 C, test specimens of 238 PuO 2 exhibit pseudobrittle behavior due to internal cracks. Plastic deformation is ''localized'' at the crack tips. Generalized plastic deformation is observed at 1500 0 C. Ultimate stress values decrease markedly with increasing temperature and decreasing strain rate, and decrease less with decreasing density, increasing storage time, and increasing grain size. Room temperature fracture is transgranular, whereas intergranular fracture predominates at elevated temperatures. Crack-free specimens of 239 PuO 2 exhibit extensive plastic deformation at 1000 0 C and above. The relationship of these test results to the impact properties of 238 PuO 2 fuel in radioisotope thermoelectric generators is discussed

Una aproximación al significado biológico del polimorfismo del Complejo Mayor de Histocompatibilidad. El modelo de la asociación HLA y ARJ

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Gloria Garavito

2002-01-01

Full Text Available Objetivos. Llevar a cabo una actualización del estado del arte acerca del significado biológico del polimorfismo del sistema genético Complejo Mayor de Histocompatibilidad (CMH. Revisar la literatura relacionada con la asociación de los antígenos de histocompatibilidad en el humano (HLA y la susceptibilidad o resistencia al desarrollo de la artritis reumatoidea juvenil (ARJ. Presentar un modelo hipotético para la comprensión de la susceptibilidad genética a desarrollar ARJ. Fuente de datos. Las referencia bibliográficas que soportan este artículo se obtuvieron a través de búsquedas en las siguientes bases de datos: Pubmed, Ovid, Ebsco. Inicialmente se encontraron 139 artículos, de los cuales se seleccionaron 75. Se incluyó también información del desarrollo de un proyecto de investigación de nuestro grupo, «Polimorfismo molecular de los antígenos HLA en ARJ» (cod. Colciencias 1215-04-280-96. Resultados. L artritis reumatoidea juvenil (ARJ es la enfermedad más común en la práctica reumatológica pediátrica y la menos estudiada inmunogenéticamente. A diferencia de la artritis reumatoide (AR del adulto, la ARJ tiene ciertas variantes clínicas, lo que la hace más interesante desde el punto de vista genético (fenotipos. En su etiopatogenia se han identificado varios factores que en su conjunto explicarían el inicio y la perpetuación de la respuesta inflamatoria que afecta las articulaciones y tejidos vecinos, y que de no ser controlados llegan a destruirlos, tal como sucede en otras enfermedades autoinmunes. La patogénesis de la enfermedad puede determinarse por alteraciones a nivel de complejo trimolecular, constituido por un antígeno putativo, el receptor de linfocitos T y el Complejo Mayor de Histocompatibilidad (CMH. Nuestro grupo durante los últimos 4 años ha estado estudiando la asociación entre ARJ y el polimorfismo de los alelos HLA DRB1* y DQB1* en niños mestizos de nuestro país. Los resultados son

Redefining design criteria for Pu-238 gloveboxes

International Nuclear Information System (INIS)

Acosta, S.V.

1998-01-01

Enclosures for confinement of special nuclear materials (SNM) have evolved into the design of gloveboxes. During the early stages of glovebox technology, established practices and process operation requirements defined design criteria. Proven boxes that performed and met or exceeded process requirements in one group or area, often could not be duplicated in other areas or processes, and till achieve the same success. Changes in materials, fabrication and installation methods often only met immediate design criteria. Standardization of design criteria took a big step during creation of ''Special-Nuclear Materials R and D Laboratory Project, Glovebox standards''. The standards defined design criteria for every type of process equipment in its most general form. Los Alamos National Laboratory (LANL) then and now has had great success with Pu-238 processing. However with ever changing Environment Safety and Health (ES and H) requirements and Ta-55 Facility Configuration Management, current design criteria are forced to explore alternative methods of glovebox design fabrication and installation. Pu-238 fuel processing operations in the Power Source Technologies Group have pushed the limitations of current design criteria. More than half of Pu-238 gloveboxes are being retrofitted or replaced to perform the specific fuel process operations. Pu-238 glovebox design criteria are headed toward process designed single use glovebox and supporting line gloveboxes. Gloveboxes that will house equipment and processes will support TA-55 Pu-238 fuel processing needs into the next century and extend glovebox expected design life

Identificación de un polimorfismo del gen Est9 relacionado con resistencia a piretroides en Rhipicephalus (Boophilus microplus

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Edgar Diaz R.

2013-10-01

Full Text Available Objetivo. Mediante procedimientos de PCR-RFLP, detectar un polimorfismo en el gen Est9 de garrapatas Rhipicephalus (Boophilus microplus resistentes a piretroides en Ibagué, Colombia, determinando el grado de asociación entre los fenotipos y los genotipos resultantes. Materiales y métodos. El ADN de 30 teleoginas R. (Boophilus microplus fenotípicamente susceptibles, resistentes o medianamente resistentes a piretroides en una prueba de Drummond modificada, fue amplificado por PCR con cebadores específicos para obtener un fragmento de 372 pb del gen Est9, que fue sometido a digestión con la enzima EcoRI para estudiar los RFLPs generados y poder diferenciar los respectivos genotipos. El grado de asociación entre los fenotipos y los genotipos resultantes se determinó mediante la prueba exacta de Fisher. Resultados. Luego de digerir el fragmento con la endonucleasa, se generaron dos segmentos en teleoginas con algún nivel de resistencia, mientras en las teleoginas susceptibles no hubo división del fragmento de 372 pb, demostrándose así la presencia de una mutación puntual y los genotipos homocigoto natural, homocigoto mutante y heterocigoto. Las diferencias altamente significativas (p<0.01 entre teleoginas susceptibles y aquellas con algún nivel de resistencia, mostraron una relación directa entre el genotipo y el fenotipo con un nivel de confianza de p=0.0009852. Conclusiones. Se comprobó, por primera vez en Colombia, la presencia de una mutación puntual en el gen Est9 de garrapatas R. (Boophilus microplus resistentes a piretroides, sugiriendo la necesidad de realizar estudios para detectar alteraciones moleculares en otros genes relacionados con quimioresistencia.

Influencia de polimorfismos genéticos de CYP3A4/5 en la farmacocinética de levonorgestrel: estudio piloto

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Iván Moreno

2012-12-01

Full Text Available Introducción. El levonorgestrel, un progestágeno sintético usado para endometriosis, dismenorrea y anticoncepción de emergencia, es rápida y completamente absorbido en el tubo digestivo. Su metabolismo es principalmente hepático, mediante las enzimas CYP3A4 y CYP3A5. Objetivo. El presente estudio tuvo como objetivo evaluar la asociación entre la farmacocinética de levonorgestrel y las variantes alélicas de CYP3A4*1B y CYP3A5*3. Materiales y métodos. En un grupo de 17 mujeres adultas sanas, que firmaron un consentimiento informado, se practicó genotipificación para CYP3A4*1B y CYP3A5*3 mediante PCR. Posteriormente, las voluntarias fueron sometidas a un estudio farmacocinético donde, luego de 12 horas de ayuno, recibieron una dosis de 0,75 mg de levonorgestrel. Se extrajeron muestras sanguíneas seriadas (0 a 24 horas y se determinaron las concentraciones de levonorgestrel mediante un método validado de UPLC-ms/ms, para luego obtener los parámetros farmacocinéticos. Todos los procedimientos consideraron los aspectos éticos de la Declaración de Helsinki y las buenas prácticas clínicas. Resultados. Las frecuencias genotípicas observadas para el grupo de estudio fueron 11,8 % para*1B/*1B; 5,8 % para *1/*1B, y 82,4 % para *1/*1 de CYP3A4*1B. Para CYP3A5*3, las frecuencias genotípicas fueron 70,5 % para *3/*3; 23,5 % para *1/*3, y 6,5 % para *1/*1. Se observa una interesante variabilidad entre las voluntarias que sugiere una relación con las variantes genéticas CYP3A, pero que no permite establecer una asociación estadísticamente significativa, presumiblemente debido albajo número de individuos homocigotos mutados de CYP3A4 y silvestres de CYP3A5. Conclusiones. Los polimorfismos genéticos podrían ser factores relevantes en la determinación de la variabilidad entre pacientes en las concentraciones plasmáticas de levonorgestrel, lo cual, sin embargo, no pudo ser establecido estadísticamente en este estudio. Por lo tanto

Associação entre polimorfismo SLC6A3 3’UTR VNTR e a resposta ao tratamento da dependência de nicotina

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Guilherme Rubino de Azevedo Focchi

2011-01-01

Full Text Available Objetivo: Avaliar a associação entre a resposta ao tratamento da dependência de nicotina com bupropiona e a presença do polimorfismo SLC6A3 3’UTR VNTR, localizado no gene que codifica o transportador dopaminérgico. Método: Foram acompanhados no Ambulatório de Tabagismo do Instituto de Psiquiatria da Faculdade de Medicina da USP 100 pacientes do sexo masculino com diagnóstico de dependência de nicotina, sem outras patologias. Todos receberam bupropiona até 300 mg ao dia por 12 semanas, associada à terapia cognitivo-comportamental em grupo. A Escala de Fagerström foi aplicada no início e no final do tratamento, e avaliou-se a parada do uso de cigarros na última semana de tratamento e um mês após. Os pacientes tiveram 10 ml de sangue colhidos e genotipados para a existência do polimorfismo SLC6A3 3’UTR VNTR. Resultados: Não foi encontrada associação entre cessação do uso de cigarro e presença do polimorfismo. Conclusão: São necessários mais estudos para avaliar se a presença do polimorfismo SLC6A3 3’UTR VNTR estaria relacionada à melhor resposta ao tratamento da dependência de nicotina.

Polimorfismos em genes de reparo do DNA (XPC, ERCC1, XRCC7) em mulheres com câncer do colo do útero

OpenAIRE

Saffar, Issamir Farias [UNIFESP

2010-01-01

Estudos demonstram que polimorfismos em genes relacionados ao reparo do DNA estão envolvidos na patogênese de diversas doenças neoplásicas, como o câncer ginecológico, particularmente o câncer do colo do útero. O presente estudo, caso-controle, compara os polimorfismos dos genes XPC, ERCC1 e XRCC7 em 77 mulheres com câncer cervical (70 casos de carcinoma espinocelular e 7 casos de adenocarcinoma do colo do útero) e 73 mulheres saudáveis atendidas no Hospital do Câncer Alfredo Abrão, entre Jun...

Análisis de polimorfismos APO-E en mujeres colombianas con osteoporosis y correlación con variables clínicas y sociales de riesgo.

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Elsa Villarreal

2004-03-01

Full Text Available Varios estudios han demostrado la asociación de los polimorfismos de la apolipoproteína E (APO-E con la osteoporosis, especialmente, la APO-E 4. Para analizar los polimorfismos APOE e identificar la asociación con variables clínicas y sociales, se realizó un estudio descriptivo de 32 mujeres con osteoporosis, provenientes de diferentes regiones de Colombia, mediante metodologías PCR y RFLP. Se observaron en osteoporosis, osteopenia y osteoporosis combinada con osteopenia frecuencias para el genotipo ?3/?3 en el 84,3% (n=27, y en el 15,6% para los genotipos con el alelo e4 (?3/e4=12,5%, ?=4; ?4/?4=3,1%, n=1; la misma tendencia se observó en la distribución por edad de la menopausia, ?3/?3 en el 83,3% (n=25, y genotipos con el alelo ?4 en el 16,6% (n=5 (?3/?4=13,3%, n=4; ?4/?4=3,3%, n=1. No hubo asociación de APO-E4 con estrato socioeconómico, fracturas, enfermedades o consumo de lácteos. Aunque no hubo efecto del alelo ?4 en la densidad mineral ósea (DMO de la columna lumbar: ?4+/-(?3/?4 0,960±0,144 g/cm2; ?4+/+ (?4/?4 0,873±0,00 g/cm2; ?4-/- (?3/?3 0,858±0,160 g/cm2; p=0,49, ni en cuello femoral: ?4+/-(?3/?4 0,841±0,026 g/cm2; ?4+/+ (?4/?4 0,842±0,00 g/cm2; ?4- /- (?3/?3 0,735±0,013 g/cm2, p=0,14, al explorar las diferencias de medias de DMO en el cuello femoral, se observó una diferencia significativa, t=4,17 p=0,05. Estos datos confirman una frecuencia del alelo e4 similar a lo reportado en poblaciones caucásicas y japonesas; se sugiere realizar estudios a gran escala para esclarecer el impacto de la APO-E sobre la DMO y su relación dosis-efecto.

O papel do polimorfismo funcional VNTR da região promotora do gene MAOA nos transtornos psiquiátricos

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Sílvia A. Nishioka

2011-01-01

Full Text Available INTRODUÇÃO: Muitos estudos têm investigado a associação do polimorfismo VNTR (número variável de repetições em série localizado na região promotora do gene da enzima monoamina oxidase A (MAOA com alterações no comportamento humano e em diversos transtornos psiquiátricos. OBJETIVO: O objetivo do presente trabalho foi revisar a literatura sobre a participação desse polimorfismo funcional na modulação do comportamento humano para o desenvolvimento dos transtornos psiquiátricos. MÉTODO: A pesquisa foi realizada na literatura em inglês, de janeiro de 1998 a junho de 2009, disponível no Medline, Embase, Web of Science e na base de dados PsycInfo, utilizando os seguintes termos: "MAOA e comportamento humano" e "MAOA e psiquiatria". RESULTADOS: Foram encontrados 3.873 estudos. Desses, 109 foram selecionados e incluídos na revisão. Encontrou-se associação de alelos de baixa atividade do VNTR com transtorno de personalidade antissocial, transtorno de conduta, transtorno de déficit de atenção e hiperatividade, jogo patológico e dependência de substâncias. Alelos da alta atividade da MAOA foram associados a depressão, ansiedade, neuroticismo e anorexia nervosa. Não se encontrou associação entre polimorfismos da MAOA e esquizofrenia e transtorno bipolar. CONCLUSÃO: Os principais achados dão suporte ao papel do polimorfismo VNTR da região promotora do gene da MAOA em alguns transtornos psiquiátricos, apesar das divergências encontradas devidas às dificuldades metodológicas de estudos em genética. De modo geral, os estudos associam os alelos de baixa atividade da MAOA com comportamentos impulsivos e agressivos ("comportamentos hiperativos", enquanto os alelos de alta atividade do gene são mais associados a "comportamentos hipoativos".

Polimorfismos de DNA nos genes dos receptores de estrogênio e FSHR e associação com resposta superovulatória em bovinos

OpenAIRE

Valeriano, Ana Cláudia de Melo

2010-01-01

Estudos baseados em genes candidatos buscam identificar polimorfismos e a prospecção de genes candidatos que estão envolvidos no processo de ovulação são ferramentas de importantes quando se pretende incrementar a eficiência reprodutiva de rebanhos e melhorar as respostas das biotécnicas de multiplicação animal. Sendo assim, o objetivo deste estudo foi sequenciar e detectar polimorfismos em parte do “exon” 10 do gene do receptor do hormônio folículo estimulante (FSHR); genotipar doadoras de e...

El papel de la genética en la aparición y desarrollo de la periodontitis: II: Polimorfismos asociados a la enfermedad periodontal The role of genetics in the development and progression of periodontitis: II: Polymorphism associated to periodontal disease

OpenAIRE

D. Rodrigo-Gómez; A. Oteo-Calatayud; A. Alonso-Rosado; A. Bascones-Martínez

2008-01-01

La periodontitis es una enfermedad multifactorial que resulta de la interacción de bacterias periodontopatógenas con los mecanismos de respuesta inmune del huésped y que se caracteriza por una reacción inflamatoria que afecta al aparato de inserción del diente. Las enfermedades multifactoriales habitualmente envuelven complejas interacciones de muchos genes y factores ambientales. El tipo de variaciones genéticas involucradas en este tipo de enfermedades se denominan polimorfismos genéticos, ...

Desarrollo y validación de una reacción en cadena de la polimerasa múltiple para la identificación de los serogrupos B, C2, D y E de Salmonella enterica

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Nora Cardona-Castro

2009-06-01

Conclusiones. El polimorfismo de los genes rfbJ y wzx permitió desarrollar un método de tipificación molecular sensible, específico y reproducible, que podría servir de apoyo a la serotipificación para identificar serogrupos de Salmonella.

/sup 238/Pu fuel form processes quarterly report, April-June 1980

Energy Technology Data Exchange (ETDEWEB)

Folger, R. L.

1980-06-01

Savannah River Laboratory (SRL) completed the development of a production process to fabricate /sup 238/PuO/sub 2/ fuel forms for the GPHS. The fabrication flowsheet was based on a flowsheet originally developed at Los Alamos National Scientific Laboratory (LANSL). A summary report of the SRL process development effort is presented.

Efecto del Polimorfismo del Intrón 6 del Gen LTF Bovino con Algunas Enfermedades de Alta Incidencia en la Producción Lechera Effect of the Polymorphism in the Intron 6 of the Bovine LTF Gene with Some Diseases of High Incidence in Dairy Production

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Nancy Rodríguez Colorado

2012-06-01

Full Text Available Resumen. El objetivo de la investigación fue determinar la asociación del polimorfismo (C/T del intrón 6 del gen de la bLTF, con la incidencia de algunas enfermedades en ganado lechero. Para ello fueron observadas 482 vacas Holstein, durante al menos una lactancia, determinando la incidencia de algunas de las enfermedades mas importantes en la ganaderia de leche. La genotipificación para el polimorfismo de bLTF, se hizo usando la técnica de PCR-RFLP con DNA extraído de sangre periférica mediante la técnica de salting out. Para estudiar la asociación de los alelos del gen LTF, se utilizó el alelo B como control y se determinó el Odds Ratio (OR. Como resultados se obtiene que las frecuencias de los alelos A y B para el gen bLTF fueron 0,78 y 0,22 respectivamente. Las frecuencias genotípicas fueron 0,60, 0,36 y 0,04 para AA, AB y BB respectivamente. Una asociación altamente significativa (P≤0,001 fue hallada entre la incidencia de mastitis clínica y el polimorfismo del gen LTF. Los individuos portadores del alelo B tuvieron una probabilidad de incidencia de mastitis dos veces superior a los portadores del alelo A (OR=2.115 IC del 95%, 1.392-3.213. En el caso de la mastitis subclínica la probabilidad de incidencia fue de 1,6 veces más en los portadores del alelo B, con un OR=1.637 IC del 95% 1.184-2.264. Para la incidencia de enfermedades metabólicas, reproductivas, respiratorias, parasitarias, cáncer y cojeras, no se halló diferencia significativa (P>0,05 y se encontró asociación del alelo B del polimorfismo del intrón 6 del gen bLTF con la incidencia de mastitis clínica y subclínica.Abstract. The research objective was to determine the association of polymorphism (C/T of intron 6 bLTF gene, with the incidence of some diseases on dairy cattle. A total of 482 Holstein cows located in different herds in the department of Antioquia - Colombia, were used to follow the incidence of disease, for at least a full lactation

Variants of mtDNA among islanders of the lake Titicaca: highest frequency of haplotype B1 and evidence of founder effect

OpenAIRE

Sandoval, José; Delgado, Bedsabé; Rivas, Luis; Bonilla, Bertha; Nugent, Daniel; Fujita, Ricardo

2004-01-01

Los polimorfismos del ADN mitocondrial son herramientas en el estudio comparativo de poblaciones modernas y antiguas. Entre los más usados están los haplotipos mitocondriales basados en RFLP (polimorfismo de longitud de fragmentos de restricción) y un sistema de inserción /deleción. El presente estudio establece la frecuencia de estos haplotipos y compara un total de 144 individuos representativos de las islas Taquile y Amantaní (lengua quechua) y de las islas de Los Uros y Anapia (lengua aym...

Study of association between genetic polymorphisms of phospholipase A2 enzymes and Alzheimer's disease Associação entre polimorfismos das enzimas fosfolipases A2 e doença de Alzheimer

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Quirino Cordeiro

2010-04-01

Full Text Available Several genes have been related to late-onset Alzheimer's disease (LOAD. Phospholipases A2 (PLA2 influence the processing and secretion of the amyloid precursor protein, which gives rise to the beta-amyloid peptide, the major component of the amyloid plaque in AD. Hence, in the present study, polymorphisms of three genes encoding PLA2 enzymes group (cytosolic PLA2: BanI cPLA2 polymorphism; calcium-independent PLA2: AvrII iPLA2 polymorphism; PAFAH: Val279Phe PAFAH polymorphism were analysed in a case-control sample using 58 patients with LOAD and 107 matched healthy controls. There was a genotypic association between the BanI cPLA2 polymorphism and LOAD (χ2=6.25, 2df, p=0.04, however there was no allelic association. There were no associations between AvrII iPLA2 and Val279Phe PAFAH polymorphisms and LOAD. These data suggest that the BanI cPLA2 polymorphism may play a role in the susceptibility for LOAD in our Brazilian sample.Vários genes têm sido investigados como fatores de risco para o desenvolvimento da doença de Alzheimer (DA de início tardio. As fosfolipases A2 (PLA2 influenciam o processamento e secreção da proteína precursora do amilóide, que dá origem ao peptídeo meta-amilóide, o principal componente da placa amilóide na DA. Assim, no presente estudo, foram analisados três polimorfismos genéticos que codificam enzimas do grupo das PLA2 (PLA2 citosólica: polimorfismo BanI cPLA2; PLA2 cálcio-independente: polimorfismo AvrII iPLA2; PAFAH: polimorfismo Val279Phe PAFAH em 58 pacientes com DA de início tardio e 107 controles saudáveis pareados. Houve associação genotípica entre o polimorfismo BanI cPLA2 e DA de início tardio (χ2=6,25, 2df, p=0,04; no entanto não foi observada associação alélica. Não houve associação entre os polimorfismos AvrII iPLA2 e Val279Phe PAFAH com a doença. Tais dados sugerem que o polimorfismo BanI cPLA2 pode estar envolvido como fator de susceptibilidade para DA de início tardio em

A study of the comparison between human and animal excretion data following inhalation exposure to plutonium 238 oxide aerosols

International Nuclear Information System (INIS)

Moss, W.D.; Martinez, G.; Gautier, M.A.

1985-01-01

Bioassay urine samples obtained since 1971 from eight Los Alamos employees, accidentally exposed by inhalation to high-fired plutonium-238 oxide aerosols, were studied and compared with excretion data obtained from Beagle dogs exposed to /sup 238/PuO/sub 2/ aerosols. The early period Pu human excretion data from the inhalation exposure were unexpected and were unlike previously studied occupational exposure urinary data obtained at Los Alamos. The initial urine samples collected on day one were below the detection limits of the analytical method (0.01 pCi). Within thirty days, however, detectible concentrations of Pu were measured in the urine for several of the exposed personnel. The amounts of Pu excreted continued to increase in each of the cases throughout the first year and the individual patterns of Pu excretion were similar. The human urinary excretion data was compared with similar excretion data obtained from an animal study conducted by the Inhalation Toxicology Research Institute (Me81). In the animal study, Beagle dogs received inhalation exposure to one of three sizes of monodisperse of polydisperse aerosol of /sup 238/PuO/sub 2/. Periodic sacrifice of pairs of dogs during the 4 years after the inhalation exposure provided data on the retention, translocation and mode of excretion of /sup 238/Pu. The comparison of human and animal /sup 238/Pu excretion data supported the observation that the excretion data were similar between the two species and that the animal excretion models can be applied to predict the human /sup 238/Pu excretion following inhalation exposure to high-fired oxides of /sup 238/Pu

Polymorphisms in the 5-HTR2A gene related to obstructive sleep apnea syndrome Polimorfismos no gene HTR2A relacionados à síndrome da apneia obstrutiva do sono

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Vânia Belintani Piatto

2011-06-01

Full Text Available Obstructive sleep apnea syndrome (OSAS is one of the most complex disorders of sleep; it involves several genetic factors that contribute to the phenotype. Serotonin (5-HT regulates a variety of visceral and physiological functions, including sleep. Gene 5-HTR2A polymorphisms may change the transcription of several receptors in the serotoninergic system, thereby contributing to OSAS. AIM: To investigate the prevalence of T102C and -1438G/A polymorphisms in the 5-HTR2A gene of patients with and without OSAS . MATERIAL AND METHOD: A molecular study of 100 index-cases and 100 controls of both genders. DNA was extracted from blood leukocytes samples and the regions that enclose both polymorphisms were amplified with PCR-RFLP. STUDY DESIGN: A cross-sectional case study. RESULTS: There was a significant prevalence of males in index cases compared to controls (pA síndrome da apneia obstrutiva do sono (SAOS é um dos distúrbios mais complexos do sono, envolvendo múltiplos fatores genéticos contribuintes para o fenótipo. A serotonina (5-HT está envolvida na regulação de uma variedade de funções viscerais e fisiológicas, inclusive o sono. Polimorfismos no gene 5-HTR2A podem alterar a transcrição, afetando o número de receptores do sistema serotoninérgico, contribuindo para a SAOS. OBJETIVO: Investigar a prevalência dos polimorfismos T102C e -1438G/A no gene HTR2A em pacientes com e sem SAOS. MATERIAL E MÉTODO: Estudo molecular em 100 pacientes como casos-índice e em 100 como grupo controle, de ambos os gêneros. O DNA foi extraído de leucócitos de sangue periférico e realizada a amplificação das regiões que abrangem ambos os polimorfismos pelas técnicas da PCR-RFLP. DESENHO DO ESTUDO: Estudo de caso/controle em corte transversal. Resultados: Houve prevalência significativa do gênero masculino nos casos-índice em relação aos controles (p<0,0001. Para o polimorfismo T102C, não houve diferença genotípica significante entre

Efeitos da atorvastatina e do polimorfismo T-786C do gene eNOS sobre parâmetros do metabolismo lipídico plasmático

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Vanessa Helena de Souza Zago

2013-01-01

Full Text Available FUNDAMENTO: A atividade do óxido nítrico sintase endotelial (eNOS pode ser modulada pelo colesterol da lipoproteína de alta densidade (HDL-C, estatinas ou polimorfismos, como o T-786C de eNOS. OBJETIVO: Este estudo teve como objetivo avaliar se o polimorfismo T-786C está associado a alterações nos efeitos da atorvastatina no perfil lipídico, nas concentrações de metabólitos de óxido nítrico (NO e da proteína C reativa de alta sensibilidade (PCR-as. MÉTODOS: Trinta voluntários do sexo masculino, assintomáticos, com idade entre 18-56 anos foram genotipados e classificados de acordo com a ausência (TT, n = 15 ou presença (CC, n = 15 do polimorfismo. Eles foram selecionados aleatoriamente para a utilização de placebo e atorvastatina (10 mg/dia por 14 dias. Após cada tratamento foram medidos lípides, lipoproteínas, frações HDL2 e HDL3, atividade da proteína de transferência de colesteril éster (CETP, metabólitos de NO e PCR-as. RESULTADOS: As comparações entre genótipos após a administração de placebo mostraram aumento da atividade da CETP polimorfismo-dependente (TT, 12 ± 7; CC, 22 ± 12, p < 0,05. As análises da interação entre os tratamentos indicaram que a atorvastatina tem efeito sobre colesterol, LDL, nitrito e razões lípides/proteínas (HDL2 e HDL3 (p < 0,001 em ambos os genótipos. É interessante notar as interações genótipo/droga sobre a CETP (p < 0,07 e a lipoproteína (a [Lp(a] (p < 0,056, levando a uma diminuição limítrofe da CETP, embora sem afetar a Lp(a. A PRC-as não mostrou alterações. CONCLUSÃO: Os resultados sugerem que o tratamento com estatinas pode ser relevante para a prevenção primária da aterosclerose em pacientes com o polimorfismo T-786C do eNOS, considerando os efeitos no metabolismo lipídico.

Plutonium-238 Decision Analysis

International Nuclear Information System (INIS)

Brown, Mike; Lechel, David J.; Leigh, C.D.

1999-01-01

Five transuranic (TRU) waste sites in the Department of Energy (DOE) complex, collectively, have more than 2,100 cubic meters of Plutonium-238 (Pu-238) TRU waste that exceed the wattage restrictions of the Transuranic Package Transporter-II (TRUPACT-11). The Waste Isolation Pilot Plant (WIPP) is being developed by the DOE as a repository for TRU waste. With the Waste Isolation Pilot Plant (WIPP) opening in 1999, these sites are faced with a need to develop waste management practices that will enable the transportation of Pu-238 TRU waste to WIPP for disposal. This paper describes a decision analysis that provided a logical framework for addressing the Pu-238 TRU waste issue. The insights that can be gained by performing a formalized decision analysis are multifold. First and foremost, the very process. of formulating a decision tree forces the decision maker into structured, logical thinking where alternatives can be evaluated one against the other using a uniform set of criteria. In the process of developing the decision tree for transportation of Pu-238 TRU waste, several alternatives were eliminated and the logical order for decision making was discovered. Moreover, the key areas of uncertainty for proposed alternatives were identified and quantified. The decision analysis showed that the DOE can employ a combination approach where they will (1) use headspace gas analyses to show that a fraction of the Pu-238 TRU waste drums are no longer generating hydrogen gas and can be shipped to WIPP ''as-is'', (2) use drums and bags with advanced filter systems to repackage Pu-238 TRU waste drums that are still generating hydrogen, and (3) add hydrogen getter materials to the inner containment vessel of the TRUPACT-11to relieve the build-up of hydrogen gas during transportation of the Pu-238 TRU waste drums

Marcadores moleculares asociados a la Capacidad de Retención de Agua (CRA) en carne de Bos indicus y sus cruces

OpenAIRE

Leal Gutiérrez, Joel David

2013-01-01

La Capacidad de Retención de Agua (CRA) es una de las características de la carne con mayor efecto sobre la rentabilidad del sector, al estar asociada a las mermas y a la jugosidad. Los objetivos principales son: resaltar la importancia de la CRA de la carne de bovino, evaluar el desempeño de estos parámetros según los factores tiempo de maduración y cruce de los animales y establecer polimorfismos en genes candidatos asociados al parámetro evaluado. Varios genes y sus polimorfismos han sido ...

Asociación entre el polimorfismo genético de la apolipoproteína E (ApoE y la enfermedad de Parkinson

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Victoria Marca

2013-07-01

Full Text Available Introducción: En nuestro país, con el incremento en la esperanza de vida, existe una tendencia creciente de enfermedades neurodegenerativas, por lo que se hace necesario realizar estudios sobre factores de riesgo genético en personas afectadas con la enfermedad de Parkinson (EP, entre ellos el gen de la apolipoproteína E (ApoE, ya que esta asociación es desconocida en nuestra población. Objetivo: Determinar la asociación del polimorfismo en el gen ApoE con la EP. Diseño: Estudio asociativo, observacional tipo casos y controles. Lugar: Instituto Nacional de Ciencias Neurológicas, Lima, Perú. Participantes: Personas de ambos sexos, 163 pacientes con la EP y 176 controles. Intervenciones: Extracción de ADN genómico según metodología estándar. Análisis del gen APOE mediante técnica PCR-RFLP. Principales medidas de resultados: Frecuencias genotípicas y alélicas del gen ApoE en los casos y controles, medidas de asociación y de riesgo. Resultados: No se encontró diferencias significativas entre el grupo control y los pacientes según genotipo de ApoE. La frecuencia del alelo ε4 fue similar en pacientes y en controles. El odds ratio para el alelo ε4 de la ApoE fue 1,0852 (IC 95%: 0,5812 a 2,0266. La edad de inicio de la EP no tuvo relaciσn con los genotipos ApoE. Conclusiones: El alelo ε4 de la ApoE no podrνa ser considerado un factor de riesgo para la EP, y los genotipos de la ApoE no se asociaron con la edad de inicio en esta muestra evaluada.

Polimorfismos genéticos do fator de crescimento do endotélio vascular na pré-eclâmpsia Genetic polymorphisms of vascular endothelial growth factor in pre-eclampsia

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Valquiria Maria de Paula Cunha

2011-07-01

Full Text Available OBJETIVO: Identificar polimorfismos genéticos do fator de crescimento do endotélio vascular (VEGF, posições +936C/T e -2578C/A, em mulheres com pré-eclâmpsia. MÉTODOS:Trata-se de um estudo transversal,constituído por 80 mulheres distribuídas em dois grupos: pré-eclâmpsia e grupo controle. A caracterização da amostra foi realizada mediante entrevista pré-estruturadae complementada por dados transcritos dos prontuários. Para identificação dos polimorfismos foi realizada extração de DNA, amplificação das sequências pela Reação em Cadeia da Polimerase (PCR com primers específicos e análise por Polimorfismos de Comprimentos de Fragmentos de Restrição (RFLP. A análise estatística dos resultados foi realizada de forma descritiva e pelo teste do . O modelo de regressão logística múltipla foi utilizado para determinar o efeito dos polimorfismos na pré-eclampsia. RESULTADOS: Evidenciou-se uma maior frequência do alelo T do polimorfismo VEGF +936C/T nas pacientes com pré-eclâmpsia, embora com diferença não significativa.A presença do alelo A do VEGF -2578C/A foi maior no grupo controle, com diferença significativa. CONCLUSÕES: Não foi observada associação significativa do polimorfismo VEGF +936C/T com a pré-eclâmpsia. Para o polimorfismo VEGF -2578C/A observa-se diferença significativa entre os grupos, sendo o alelo A mais frequente no controle, sugerindo a possibilidade da portadora do alelo A apresentar menor suscetibilidade para o desenvolvimento de pré-eclâmpsia.PURPOSE: To identify genetic polymorphisms of endothelial growth factor (VEGF, positions +936C/T and -2578C/A, in women with pre-eclampsia. METHODS: This was a cross-sectional study conducted on 80 women divided into two groups: pre-eclampsia and control. The sample was characterized using a pre-structured interview and data transcribed from the medical records. DNA extraction, amplification of sequences by the Polymerase Chain Reaction (PCR

Dicty_cDB: SLH238 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available SL (Link to library) SLH238 (Link to dictyBase) - G22491 DDB0188118 Contig-U04168-1 SLH2...38F (Link to Original site) SLH238F 383 - - - - - - Show SLH238 Library SL (Link to library) Clone ID SLH2...riginal site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/SL/SLH2-B/SLH238Q.Seq.d/ ...Representative seq. ID SLH238F (Link to Original site) Representative DNA sequence >SLH238 (SLH238Q) /CSM/SL/SLH2-B/SLH2...e E Sequences producing significant alignments: (bits) Value SLH238 (SLH238Q) /CSM/SL/SLH2-B/SLH2

Two 238Pu inhalation incidents

International Nuclear Information System (INIS)

Fleming, R.R.; Hall, R.M.

1978-06-01

Two employees inhaled significant amounts of 238 Pu in separate unrelated contamination incidents in 1977. Both acute exposure incidents are described and the urine, feces, and in-vivo chest count data for each employee. Case B ( 238 PuNO 3 ) received 24 DTPA treatments beginning the day of the incident while, for medical reasons, Case A ( 238 PuO 2 ) received no therapy

49 CFR 238.13 - Preemptive effect.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Preemptive effect. 238.13 Section 238.13 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS General § 238.13 Preemptive effect. (a...

49 CFR 238.237 - Automated monitoring.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Automated monitoring. 238.237 Section 238.237 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Equipment § 238.237 Automated monitoring. (a) Except as further specified in this paragraph, on or after...

49 CFR 238.217 - Side structure.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Side structure. 238.217 Section 238.217 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Equipment § 238.217 Side structure. Each passenger car shall comply with the following: (a) Side posts and...

49 CFR 238.103 - Fire safety.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Fire safety. 238.103 Section 238.103..., DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Safety Planning and General Requirements § 238.103 Fire safety. (a) Materials. (1) Materials used in constructing a passenger car or a cab of a...

49 CFR 238.445 - Automated monitoring.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Automated monitoring. 238.445 Section 238.445... Equipment § 238.445 Automated monitoring. (a) Each passenger train shall be equipped to monitor the... limiting the speed of the train. (c) The monitoring system shall be designed with an automatic self-test...

49 CFR 238.429 - Safety appliances.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Safety appliances. 238.429 Section 238.429... Equipment § 238.429 Safety appliances. (a) Couplers. (1) The leading and the trailing ends of a semi... appliance mechanical strength and fasteners. (1) All handrails, handholds, and sill steps shall be made of 1...

Polimorfismo G894T da óxido nítrico-sintetase endotelial e o prognóstico na insuficiência cardíaca

Directory of Open Access Journals (Sweden)

Oziel Marcio Araujo Tardin

2013-10-01

Full Text Available FUNDAMENTO: Estudos prévios avaliaram o papel do polimorfismo genético da enzima óxido nítrico-sintetase endotelial sobre o prognóstico na insuficiência cardíaca. Entretanto, faltam estudos relacionando o G894T e a insuficiência cardíaca na população brasileira. OBJETIVO: Avaliar a associação do G894T com o prognóstico de amostra de pacientes brasileiros com insuficiência cardíaca. MÉTODOS: Coorte com 145 pacientes com insuficiência cardíaca sistólica, num segmento de 40 meses (média = 22 meses, em dois hospitais universitários do Estado do Rio de Janeiro. Foi avaliada a relação do G894T com os desfechos: remodelamento reverso; melhora da classe funcional (NYHA; taxas de mortalidade e hospitalização. Os diâmetros do átrio e ventrículo esquerdos e a fração de ejeção do ventrículo esquerdo foram medidos na admissão e após 6 meses, para avaliação do remodelamento reverso. A melhora na classe funcional foi avaliada após 6 meses e as taxas de mortalidade e de hospitalização durante todo o seguimento. A raça foi autodeclarada. O polimorfismo G894T foi analisado por reação em cadeia de polimerase e por análise do polimorfismo dos fragmentos de restrição. RESULTADOS: A frequência genotípica foi GG (40%, GT (48,3% e TT (11,7%, e a frequência alélica foi guanina (64,1% e tiamina (35,8%. Não houve diferença entre as frequências genotípica ou alélica conforme a raça autodeclarada, tampouco conforme as características basais. Não houve relação entre o genótipo ou a frequência alélica e os desfechos analisados. CONCLUSÃO: Não se observou associação do polimorfismo G894T (Glu298Asp com o prognóstico de amostra de pacientes ambulatoriais brasileiros com insuficiência cardíaca sistólica.

Search for surviving actinides and superheavy nuclei in damped collisions of 238U with 238U and 248Cm

International Nuclear Information System (INIS)

Kratz, J.V.

1980-03-01

In the present talk aspects of the reaction mechanism related to the survival probability of the heaviest fragments in 238 U + 238 U collisions are discussed first. This is followed by a description of the experiments that have been performed to search for surviving superheavy fragments in the 238 U + 238 U reaction and by a presentation of the results obtained so far. In a third section our recent first attempts with the 238 U + 248 Cm reaction are described and preliminary results are discussed. (orig.)

Papel de los polimorfismos de los genes hemo-oxigenasa 1 y 2 en el riesgo de desarrollo de esclerosis múltiple

OpenAIRE

Millán Pascual, Jorge

2016-01-01

La esclerosis múltiple (en adelante EM) muestra una susceptibilidad genética conocida desde las primeras descripciones de la enfermedad y, aunque los esfuerzos para desentrañar y comprender las bases genéticas de la enfermedad han sido contínuos, tanto con abordajes poblacionales como moleculares, los resultados son hasta la fecha modestos. La susceptibilidad genética se confirma en hechos incuestionables como la existencia de un riesgo étnico diferente, la agregación familiar y la asimetría ...

Estimates of Radionuclide Loading to Cochiti Lake from Los Alamos Canyon Using Manual and Automated Sampling

Energy Technology Data Exchange (ETDEWEB)

McLean, Christopher T. [Univ. of New Mexico, Albuquerque, NM (United States)

2000-07-01

Los Alamos National Laboratory has a long-standing program of sampling storm water runoff inside the Laboratory boundaries. In 1995, the Laboratory started collecting the samples using automated storm water sampling stations; prior to this time the samples were collected manually. The Laboratory has also been periodically collecting sediment samples from Cochiti Lake. This paper presents the data for Pu-238 and Pu-239 bound to the sediments for Los Alamos Canyon storm water runoff and compares the sampling types by mass loading and as a percentage of the sediment deposition to Cochiti Lake. The data for both manual and automated sampling are used to calculate mass loads from Los Alamos Canyon on a yearly basis. The automated samples show mass loading 200- 500 percent greater for Pu-238 and 300-700 percent greater for Pu-239 than the manual samples. Using the mean manual flow volume for mass loading calculations, the automated samples are over 900 percent greater for Pu-238 and over 1800 percent greater for Pu-239. Evaluating the Pu-238 and Pu-239 activities as a percentage of deposition to Cochiti Lake indicates that the automated samples are 700-1300 percent greater for Pu- 238 and 200-500 percent greater for Pu-239. The variance was calculated by two methods. The first method calculates the variance for each sample event. The second method calculates the variances by the total volume of water discharged in Los Alamos Canyon for the year.

Associação do polimorfismo do gene da enzima conversora da angiotensina com dados ecocardiográficos em jovens normotensos filhos de hipertensos

Directory of Open Access Journals (Sweden)

Franken Roberto Alexandre

2004-01-01

Full Text Available OBJETIVOS: Os autores objetivaram no presente estudo avaliar o polimorfismo da enzima conversora da angiotensina com dados do ecocardiograma de jovens estudantes de Medicina, filhos de hipertensos, comparados com jovens filhos de normotensos. MÉTODOS: Foram estudados 80 jovens normotensos divididos em dois grupos: 40 filhos normotensos de pais hipertensos e 40 filhos normotensos de pais hipertensos. Critérios de exclusão foram hipertensão arterial, fumo, obesidade, uso de contraceptivos orais. Uso crônico de medicamentos e presença de qualquer doença. Os alunos foram incluídos entre 1994 e 1996. Cinqüenta alunos foram submetidos a ecocardiograma transtoráxico. A análise estatística foi feita através do teste T de Student. A avaliação do polimorfismo do gene da enzima conversora da angiotensina foi feita nos 80 alunos conforme segue: 1 5 ml de sangue em tubo contendo EDTA, 2 extração do DNA, 3 medida da concentração do DNA por eletroforese, 4 reação em cadeia de polimerase com ''primer'' do gene da enzima conversora da angiotensina, 5 análise do polimorfismo do gene da enzima conversora da angiotensina através da eletroforese e 6 análise estatística através do teste do Qui-quadrado. RESULTADOS: O grupo de estudantes filhos de hipertensos mostraram maior espessura do septo interventricular (7,82mm+/-0,69 contra 7,38 +/- 0,8, p 7,82mm; DD 32%, DI 24%, II 20% contra septo 7,38mm: DD28%, DI12%, II 12%, contra septo 131,52g: DD 20,69% DI 13,79%, II 6,9% contra massa 117,11g: DD 30,43%, DI 8,7%, II 8,7% contra massa < 117,11g: DD 13,04%, DI 21,74%, II 17,39% (p=0,17 CONCLUSÃO: Encontramos diferenças entre a espessura do septo interventricular de estudantes normotensos filhos de hipertensos e filhos de normotensos. Por outro lado, não encontramos diferenças entre os grupos considerando o polimorfismo do gene da enzima de conversão da angiotensina, assim como qualquer relação do gene da enzima de conversão da

Relação entre polimorfismos de IL-8 e a gravidade da bronquiolite viral aguda

OpenAIRE

Leitão, Lidiane Alves de Azeredo

2013-01-01

Introdução : Até os 2 anos de idade, praticamente, todos os lactentes apresentam infecção por vírus sincicial respiratório (VSR). Entretanto, a gravidade da bronquiolite viral aguda (BVA) pode variar significativamente. Essa grande variação pode ser causada por fatores genéticos e imunológicos. Estudos prévios indicam que vias aéreas infectadas por VSR contêm níveis elevados de interleucina-8 (IL-8). O conhecimento de polimorfismos genéticos associados à BVA grave pode ter grande relevância c...

Polimorfismo del gen de la catecol-O-metiltransferasa (COMT) en gestantes con restricción del crecimiento intrauterino (RCIU)

OpenAIRE

Pacheco, José; Huerta, Doris; Acosta, Oscar; Cabrera, Santiago

2013-01-01

Objetivos: Establecer la asociación entre el polimorfismo Vall58Met catecol-O-metiltransferasa (COMT) y la RCIU. Diseño: Estudio relacional, observacional, tipo caso-control. Institución: Facultad de Medicina, UNMSM. Participantes: Gestantes sin y con RCIU. Intervenciones: Se obtuvo 81 muestras de sangre para genotipaje del gen COMT; 55 (67,9%) correspondieron a gestantes sin RCIU (controles) y 26 (32,1%) a madres de hijos con RCIU. Las gestantes firmaron consentimiento informado. Principales...

Adiposidade corporal, mas não resistência insulínica, associa-se ao polimorfismo -675 4G/5G no gene PAI-1 em uma amostra de crianças mexicanas

Directory of Open Access Journals (Sweden)

Ulises de la Cruz-Mosso

2013-10-01

Full Text Available OBJETIVO: Elaboramos este estudo para avaliar se o polimorfismo -675 4G/5G no gene inibidor 1 do ativador do plasminogênio se associa à obesidade e à resistência insulínica em crianças mexicanas. MÉTODOS: Foi realizado um estudo transversal em 174 crianças, 89 delas com peso normal e 85 obesas, variando sua idade de 6 a 13 anos. Todas as crianças eram do estado de Guerrero e foram recrutadas de três escolas primárias na cidade de Chilpancingo, México. Os níveis de insulina foram determinados por prova imunoenzimática. Foi usado o modelo de avaliação da homeostase para determinar resistência insulínica. O polimorfismo -675 4G/5G no gene PAI-1 foi analisado pelo método reação de polimerase em cadeia-polimorfismo no comprimento dos fragmentos de restrição. RESULTADOS: A prevalência de resistência insulínica no grupo obeso foi mais alta (49,41% do que no grupo com peso normal (16,85%. O polimorfismo 4G/5G do PAI-1 foi encontrado em equilíbrio de Hardy Weinberg. O genótipo 4G/5G contribuiu para um aumento significativo da relação cintura-quadril (β = 0,02, p = 0,006, da circunferência da cintura (β = 4,42, p = 0,009 e da espessura da prega subescapular (β = 1,79, p = 0,04, mas não se relacionou com a resistência insulínica. CONCLUSÃO: O genótipo -675 4G/5G do gene PAI-1 se associou a aumento da adiposidade corporal em crianças mexicanas.

Economical Production of Pu-238

Energy Technology Data Exchange (ETDEWEB)

Steven D. Howe; Douglas Crawford; Jorge Navarro; Terry Ring

2013-02-01

All space exploration missions traveling beyond Jupiter must use radioisotopic power sources for electrical power. The best isotope to power these sources is plutonium-238. The US supply of Pu-238 is almost exhausted and will be gone within the next decade. The Department of Energy has initiated a production program with a $10M allocation from NASA but the cost is estimated at over $100 M to get to production levels. The Center for Space Nuclear Research has conceived of a potentially better process to produce Pu-238 earlier and for significantly less cost. The new process will also produce dramatically less waste. Potentially, the front end costs could be provided by private industry such that the government only had to pay for the product produced. Under a NASA Phase I NIAC grant, the CSNR has evaluated the feasibility of using a low power, commercially available nuclear reactor to produce at least 1.5 kg of Pu-238 per year. The impact on the neutronics of the reactor have been assessed, the amount of Neptunium target material estimated, and the production rates calculated. In addition, the size of the post-irradiation processing facility has been established. In addition, a new method for fabricating the Pu-238 product into the form used for power sources has been identified to reduce the cost of the final product. In short, the concept appears to be viable, can produce the amount of Pu-238 needed to support the NASA missions, can be available within a few years, and will cost significantly less than the current DOE program.

33 CFR 110.238 - Apra Harbor, Guam.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Apra Harbor, Guam. 110.238 Section 110.238 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.238 Apra Harbor, Guam. (a) The anchorage grounds (Datum: WGS...

49 CFR 238.223 - Locomotive fuel tanks.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Locomotive fuel tanks. 238.223 Section 238.223... Equipment § 238.223 Locomotive fuel tanks. Locomotive fuel tanks shall comply with either the following or....21: (a) External fuel tanks. External locomotive fuel tanks shall comply with the requirements...

49 CFR 238.311 - Single car test.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Single car test. 238.311 Section 238.311... Requirements for Tier I Passenger Equipment § 238.311 Single car test. (a) Except for self-propelled passenger cars, single car tests of all passenger cars and all unpowered vehicles used in passenger trains shall...

49 CFR 238.229 - Safety appliances-general.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Safety appliances-general. 238.229 Section 238.229... Equipment § 238.229 Safety appliances—general. (a) Except as provided in this part, all passenger equipment continues to be subject to the safety appliance requirements contained in Federal statute at 49 U.S.C...

Asociación del polimorfismo del codon 72 del gen p53 con el riesgo de cáncer gástrico en una población de alto riesgo de Costa Rica

Directory of Open Access Journals (Sweden)

Warner Alpízar-Alpízar

2005-09-01

Full Text Available El cáncer gástrico es la segunda causa de muerte por cáncer en el mundo. Varios factores han sido asociados con el riesgo de llegar a desarrollarlo, entre ellos la predisposición genética. El gen p53 presenta un polimorfismo en el codón 72, el cual ha sido asociado con un mayor riesgo de desarrollar varios tipos de cáncer entre ellos el gástrico. El objetivo de este estudio fue determinar la asociación del polimorfismo localizado en el codón 72 del gen p53 con el riesgo de cáncer gástrico y lesiones gástricas leves en una población de alto riesgo de Costa Rica. El análisis del polimorfismo se llevó a cabo mediante PCR-RFLP, en una muestra de 58 pacientes de cáncer gástrico, 99 personas controles y 41 individuos clasificados como grupos I y II de acuerdo con la clasificación histológica japonesa. No se determinó asociación del polimorfismo del codón 72 de p53 con el riesgo de cáncer gástrico, ni de lesiones gástricas leves en la muestra estudiada. Con base en este estudio y otros que han investigado el polimorfismo del codón 72 del gen p53, no está claro el papel que podría estar jugando dicho polimorfismo en el desarrollo de cáncer gástrico. Mutaciones de novo en el gen p53 producidas durante el desarrollo neoplásico de la enfermedad podrían tener un mayor efecto que polimorfismos de línea germinal de este mismo gen. Existen otros genes polimórficos que también se han asociado con el riesgo de desarrollar cáncer gástrico.Association of the p53 codon 72 polymorphism to gastric cancer risk in a hight risk population of Costa Rica. Gastric cancer is the second most common cancer associated death cause worldwide. Several factors have been associated with higher risk to develop gastric cancer, among them genetic predisposition. The p53 gene has a polymorphism located at codon 72, which has been associated with higher risk of several types of cancer, including gastric cancer. The aim of this study was to determine

49 CFR 238.319 - Running brake test.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received, or...

49 CFR 238.114 - Rescue access windows.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Rescue access windows. 238.114 Section 238.114... § 238.114 Rescue access windows. (a) Number and location. Except as provided in paragraph (a)(1)(ii) of... rescue access windows. At least one rescue access window shall be located in each side of the car...

Polimorfismo de liposomas

Directory of Open Access Journals (Sweden)

Araceli Arteaga Jiménez

2015-06-01

Full Text Available Revisamos las teorías actuales que explican los cambios de forma de liposomas. Incluimos resultados experimentales de Microscopía Óptica (MO, Contraste de Interferencia Diferencial (DIC y Microscopía Electrónica de Criofractura (TEM que muestran la variedad de formas y tamaños de liposomas obtenidos por el método de hidratación. Presentamos una explicación sencilla del posible mecanismo de formación de liposomas helicoidales y la necesidad de formular una teoría basada en Termodinámica de No Equilibrio para entender los cambios de topología de estas fascinantes estructuras

Relación del polimorfismo TaqI del gen del receptor de la vitamina D con la lepra lepromatosa en población mexicana Association between the TaqI polymorphism of Vitamin D Receptor gene and lepromatous leprosy in a Mexican population sample

Directory of Open Access Journals (Sweden)

Jesús Salvador Velarde Félix

2009-02-01

Full Text Available OBJETIVO: Determinar la relación del polimorfismo TaqI del gen del receptor de la vitamina D (RVD con la lepra lepromatosa (LL en individuos originarios de Sinaloa, México. MATERIAL Y MÉTODOS: Se amplificó un fragmento de 740 pb del gen RVD en muestras de ADN de 71 pacientes con LL y 144 controles en el Hospital General de Culiacán durante el periodo 2004-2007. El polimorfismo se identificó mediante la endonucleasa TaqI. RESULTADOS: Se observó un aumento de relevancia estadística del genotipo TT en pacientes con LL en comparación con los controles (p= 0.040; RM= 1.82. CONCLUSIÓN: Se demuestra un nexo entre el genotipo TT y la susceptibilidad a la LL.OBJETIVE: To establish the association of the vitamin D receptor gene TaqI polymorphism with lepromatous leprosy (LL in individuals from Sinaloa, Mexico. MATERIAL AND METHODS: A 740 bp fragment was amplified from the VDR gene in DNA samples of 71 patients with LL and 144 controls in the Hospital General de Culiacán during 2004-2007. Polymorphism was identified through TaqI endonuclease. RESULTS: A significant increase in the genotype TT of the VDR gene was observed in patients when compared to controls (p = 0.040; OR = 1.82. CONCLUSIONS: Our data support the association between the TT genotype and susceptibility to LL in this Mexican population.

Genética molecular de caracteres cuantitativos en cruzamientos dialélicos de tomate

Directory of Open Access Journals (Sweden)

Guillermo Raúl Pratta

2011-05-01

Full Text Available El objetivo de este trabajo fue evaluar marcadores moleculares y caracteres cuantitativos en un cruzamiento dialélico completo sin recíprocos, entre cinco líneas recombinantes de tomate y sus híbridos. Se obtuvieron perfiles de AFLP ("amplified fragment length polymorphism" y de polipéptidos del pericarpio en cuatro estados de madurez del fruto de 15 genotipos. Se evaluaron, entre otros: peso, acidez titulable, pH, vida poscosecha y firmeza. Se calculó el porcentaje de polimorfismo para los marcadores moleculares y el porcentaje de variabilidad genética para los caracteres cuantitativos en el grupo de líneas recombinantes, el de híbridos y el conjunto de genotipos. Se realizaron análisis de agrupamiento con cada nivel de variación genética. Para AFLP, el porcentaje de polimorfismo varió entre 34 y 54% y, para los perfiles polipeptídicos, entre 40 y 78%. Mayor polimorfismo fue observado en el grupo de híbridos. La variabilidad genética fue de 100% para acidez y 34% para firmeza, con los mayores valores en los parentales. La similitud genética varió entre los genotipos según el nivel de variación genética; pero la consistencia en el agrupamiento de algunas líneas recombinantes y sus híbridos fue conservada, lo que evidenció asociaciones entre los datos moleculares y fenotípicos.

Plutonium 238/239 Decorporation Model

Science.gov (United States)

2014-10-01

4. Transfer Coefficients for the DTPA Biokinetic Model (Breustedt 2009) ...................... 25 Table 5. Decay Properties of Pu-238 and Pu-239...volume 2), cesium-137 (volume 3), F. tularensis (volume 4), sulfur mustard (volume 5), americium-241 (volume 6), Y. pestis (volume 7), botulinum ... toxin (volume 8), plutonium-238/239 (volume 9) and vesicants (volume 10, an expansion on volume 5). This paper presents an inhalation exposure model for

Efeito do exercício físico e do polimorfismo T-786C na pressão arterial e no fluxo sanguíneo de idosas Efecto del ejercicio físico y del polimorfismo T-786C en la presión arterial y en el flujo sanguíneo de añosas Effect of physical activity and t-786C polymorphism in blood pressure and blood flow in the elderly

Directory of Open Access Journals (Sweden)

Anderson Saranz Zago

2010-10-01

ón, pudiendo este efecto ser revertido por el ejercicio físico. OBJETIVO: Investigar la influencia del entrenamiento aeróbico y del polimorfismo T-786C en las concentraciones de los metabolitos del óxido nítrico (NOx, en el flujo sanguíneo (FS y en la presión arterial (PA. MÉTODOS: Treinta y dos añosas prehipertensas (59 ± 6 años fueron separadas en dos grupos de acuerdo con el polimorfismo T-786C (TT y TC+CC. Fueron analizadas las concentraciones de NOx (plasma y flujo sanguíneo por pletismografía de oclusión venosa en reposo, 1, 2 y 3 minutos post oclusión (FS-0, FS-1, FS-2, FS-3, respectivamente. Las evaluaciones fueron realizadas antes y después de 6 meses de un programa de ejercicio aeróbico. RESULTADOS: En las evaluaciones pre entrenamiento, los niveles de NOx fueron menores en el grupo TC+CC en relación al grupo TT. El grupo TT presentó correlaciones entre NOx y FS-0 (r = 0,6 y presión arterial diastólica (PAD y FS-0 (r = -0,7, sin embargo ninguna correlación fue encontrada en el grupo TC+CC. En las evaluaciones post entrenamiento, ocurrieron correlaciones entre NOx y FS-0 (r = 0,6 y en los cambios del NOx y PAD (r = -0,6 en el grupo TT. También fueron obtenidas correlaciones entre PAD y FS-1 (r = -0,8, PAD y FS-2 (r = -0,6, PAD y FS-3 (r = -0,6, en los cambios entre NOx y FS-1 (r = 0,8 y cambios del NOx y PAD (r = -0,7 en el grupo TC+CC. CONCLUSIÓN: Se concluye que 6 meses de ejercicio aeróbico pueden contribuir a aumentar las relaciones existentes entre NO, PA y FS en añosas portadoras del alelo C.BACKGROUND: The T-786C polymorphism of the gene for endothelial nitric oxide synthase (eNOS and superoxide anion production may reduce production and bioavailability of nitric oxide, affecting the degree of vasodilation. This effect can be reversed by exercise. OBJECTIVE: To investigate the influence of aerobic training and T-786C polymorphism in the concentrations of nitric oxide metabolites (NOx in blood flow (BF and blood pressure (BP. METHODS

16 CFR 238.1 - Bait advertisement.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Bait advertisement. 238.1 Section 238.1 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES AGAINST BAIT ADVERTISING... when the offer is not a bona fide effort to sell the advertised product. [Guide 1] ...

Estructura y diversidad genética en vacas Holstein de Antioquia usando un polimorfismo del gen bGH

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Juan Rincon F.

2013-03-01

Full Text Available Objetivo. Determinar las frecuencias alélicas y genotípicas del polimorfismo del intrón 3 del gen bGH y estimar algunos parámetros de estructura poblacional en ganado Holstein. Materiales y métodos. El estudio se realizó con 1366 vacas Holstein en 120 hatos de 11 municipios del departamento de Antioquia. Se extrajo DNA por el método de Salting out y la genotipificación se realizó usando la técnica de PCR-RFLPs. La diversidad genética se determinó mediante la comparación de las heterocigosidades, El equilibrio de Hardy-Weinberg (HW y la diferenciación genética entre las poblaciones se realizó usando el software Arlequín 2.0 Las frecuencias alélicas y genotípicas se evaluaron mediante el paquete estadístico SAS®. Resultados. Las frecuencias genotípicas encontradas fueron 0.764 (+/+, 0.223 (+/- y 0.013 (-/- y las frecuencias alélicas 0.876 (+ y 0.124 (-. No se encontraron desviaciones del Equilibrio de Hardy Weinberg en ninguna de las subpoblaciones. La diversidad genética determinada mediante la comparación de las heterocigosidades fue relativamente baja entre poblaciones pero al interior de estas no. El valor de FST de toda la población fue de 0.0068 y significativo (p<0.05, algunos FST pareados también lo fueron, tomando valores desde 0.0 a 0.13. Los estadísticos FIT y FIS no fueron significativos. Conclusiones. El gen bGH es un candidato interesante para evaluar características de importancia económica ya que no parece haber sido sometido a selección directa, presenta una variabilidad media en las poblaciones, observándose diferenciación genética significativa entre distintos municipios, producto de los diferentes sistemas de producción y acceso a las biotecnologías.

Análisis de segregantes agrupados (BSA para la detección de AFLPs ligados al gen de resistencia a PVX en Solanum commersonii

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Mónica Blanco

2005-01-01

Full Text Available Para identificar polimorfismos asociados al gen de resistencia al PVX en la papa silvestre Solanum commersonii, se realizó un análisis de segregantes agrupados (BSA asistido con AFLPs. Estos polimorfismos están basados en la localización de un locus relacionado con la resistencia al virus X de la papa (PVX. Inicialmente, mediante un análisis de ELISA, los individuos de una progenie F2 previamente inoculados con el PVX, fueron ubicados en 2 grupos, uno con los individuos resistentes y otro con los susceptibles. Posteriormente, para el BSA el ADN de todos los individuos resistentes fue mezclado, lo mismo el ADN de todos los individuos susceptibles. Ambos grupos de ADN fueron analizados independientemente, utilizando 64 diferentes combinaciones de AFLPs. El análisis de los geles resultó en la identificación de 22 combinaciones diferentes de AFLPs que generaron bandas relacionadas exclusivamente con el carácter de resistencia al PVX.

An Update on the Status of the Supply of Plutonium-238 for Future NASA Missions

Science.gov (United States)

Wham, R. M.

2016-12-01

For more than five decades, Radioisotope Power Systems (RPSs) have enabled space missions to operate in locations where the Sun's intensity is too weak, obscured, or otherwise inadequate for solar power or other conventional power‒generation technologies. The natural decay heat (0.57 W/g) from the radioisotope, plutonium-238 (238Pu), provides the thermal energy source used by an RPS to generate electricity for operation of instrumentation, as well as heat to keep key subsystems warm for missions such as Voyagers 1 and 2, the Cassini mission to Saturn, the New Horizons flyby of Pluto, and the Mars Curiosity rover which were sponsored by the National Aeronautics and Space Administration (NASA). Plutonium-238 is produced by irradiation of neptunium-237 in a nuclear reactor a relatively high neutron flux. The United States has not produced new quantities of 238Pu since the early 1990s. RPS‒powered missions have continued since then using existing 238Pu inventory managed by the U.S. Department of Energy (DOE), including material purchased from Russia. A new domestic supply is needed to ensure the continued availability of RPSs for future NASA missions. NASA and DOE are currently executing a project to reestablish a 238Pu supply capability using its existing facilities and reactors, which are much smaller than the large-scale production reactors and processing canyon equipment used previously. The project is led by the Oak Ridge National Laboratory (ORNL). Target rods, containing NpO2, will be fabricated at ORNL and irradiated in the ORNL High Flux Isotope Reactor and the Advanced Test Reactor at Idaho National Laboratory. Irradiated targets will be processed in chemical separations at the ORNL Radiochemical Engineering Center to recover the plutonium product and unconverted neptunium for recycle. The 238PuO2 product will be shipped to Los Alamos National Laboratory for fabrication of heat source pellets. Key activities, such as transport of the neptunium to ORNL

Status summary of chemical processing development in plutonium-238 supply program

Energy Technology Data Exchange (ETDEWEB)

Collins, Emory D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Benker, Dennis [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wham, Robert M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); DePaoli, David W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Delmau, Laetitia Helene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sherman, Steven R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-10-01

This document summarizes the status of development of chemical processing in the Plutonium-238 Supply Program (PSP) near the end of Demonstration 1. The objective of the PSP is “to develop, demonstrate, and document a production process that meets program objectives and to prepare for its operation” (Frazier et al. 2016). Success in the effort includes establishing capability using the current infrastructure to produce Np targets for irradiation in Department of Energy research reactors, chemically processing the irradiated targets to separate and purify the produced Pu and transferring the PuO₂ product to Los Alamos National Laboratory (LANL) at an average rate of 1.5 kg/y.

Otimização de metodologia PCR-SSP para identificação de polimorfismos genéticos de TNF e IL2 Optimization of the PCR-SSP methodology in the identification of TNF and IL2 genetic polymorphisms

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Danilo A. S. Franceschi

2009-08-01

Full Text Available A análise de polimorfismos únicos de nucleotídeos (SNPs de citocinas pode ser útil em estudos de frequências alélicas e genotípicas em populações saudáveis de diversas regiões, em estudos de associação com doenças infecciosas ou autoimunes, em estudos antropológicos e na evolução pós-transplante. Estes SNPs podem ser avaliados por diferentes métodos moleculares. O objetivo deste estudo foi aperfeiçoar uma metodologia PCR-SSP simples e rápida para a genotipagem de três SNPs de citocinas usando um único teste laboratorial. Para a identificação de IL2-330T/G e IL2+166G/T foram utilizados dois procedimentos na mesma genotipagem, cada um baseado no uso de quatro iniciadores. Para a detecção de TNF-238G/A foram utilizados dois iniciadores que amplificam a guanina e adenina na posição -238. Este estudo permitiu aperfeiçoar um método simples e rápido para identificar três SNPs de citocinas num único teste, podendo ser utilizado em qualquer laboratório de biologia molecular, como alternativa ao uso de kits de alto custo.The analysis of cytokine single nucleotide polymorphisms (SNPs can be useful in studies of allelic and genotypic frequencies in healthy populations from different regions of Brazil, in association studies of infectious or auto-immune diseases, in anthropological studies and in studies on post-transplant evolution. These SNPs can be assessed by different molecular methods. The objective of this study was to improve a simple and fast methodology, PCR-SSP, for the genotyping of three cytokine SNPs using a single laboratorial test. To identify IL2-330T/G and IL2+166G/T, two procedures were used in the same genotyping assay, each one based on the use of 4 primers. To detect TNF-238G/A, two primers were used that amplify guanine and adenine at position -238. This study enabled the improvement of a simple and fast method for identifying three cytokine SNPs in a single test, which can be adopted in any Molecular

238U content in soils of Byelorussia

International Nuclear Information System (INIS)

Shagalova, Eh.D.

1986-01-01

Results of detection in Byelorussian soils of a heavy natural radionuclide 238 U and its content in humus horizons of the soils on map-schemes are presented. 238 U content is determined by complete decomposition of soils by acids, isolation from thorium using EhDEh-10 P anionite and subsequent solution colorimetry. It is shown that the content of uranium-238 in soils decreases from the North to the South. Its maximum amount (>2x10 -4 %) is detected in turfy-podsolic soils in lake-glacier loams; the minimum one ( -4 %)- in peatymarshy soils. The map-scheme of 238 U content is a background base. Using the background base it is possible to trace the change in uranium content in soils under conditions of technogenic effect and to substantiate the efficiency of environment protection measures

Ontogenetic polychromatism in marsupial frogs (Anura: Hylidae Ontogenetic polychromatism in marsupial frogs (Anura: Hylidae

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Duellman William E.

1986-12-01

Full Text Available Color polymorphism is common in many species of marsupial frogs.  Extreme cases of pattern polymorphism are documented in four species. In Amphignathodon guentheri, Castrotheca aureomaculata, G. qriswoldi, and G. helenae juveniles are known to have only one color morph, where as two or more patterns exist in adults. In these species, polymorphism apparently develops ontogenetically. El polimorfismo cromático es común a algunas especies de sapos marsupiales. Casos extremos del modelo de polimorfismo son evidentes en cuatro especies Amphignathodon guentheri, Gastrotheca aureomaculata, G. griswoldi, y G. helenae. En estas especies, se sabe que los juveniles tienen sólo un morfo de color; el polimorfismo, al parecer, se desarrolla ontogenéticamente.

49 CFR 238.423 - Fuel tanks.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Fuel tanks. 238.423 Section 238.423 Transportation....423 Fuel tanks. (a) External fuel tanks. Each type of external fuel tank must be approved by FRA's Associate Administrator for Safety upon a showing that the fuel tank provides a level of safety at least...

CYP1A1, CYP2E1 Y RIESGO A CÁNCER GÁSTRICO EN UNA POBLACIÓN COLOMBIANA DE ALTA INCIDENCIA

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Eduardo Castaño

2009-09-01

Full Text Available El objetivo fue probar la hipótesis de que en casos y controles, de una población colombiana con alta incidencia de cáncer gástrico, muestran diferencias significativas entre las frecuencias de los polimorfismos genéticos CYP1A1-m2 y CYP2E1-c2; y a la vez, probar si hay diferencias entre el hábito del tabaquismo, el consumo de licor y el estrato socioeconómico; así como también sus posibles interacciones. Ochenta y siete pacientes afectados por cáncer gástrico e igual número de controles, del mismo grupo poblacional, genéticamente aislado, pertenecientes a la comunidad “paisa” del departamento de Caldas, fueron genotipíficados por medio de PCR-RFLPs para los polimorfismos CYP1A1-m2 y CYP2E1-c2. Además, se tuvo en cuenta las variables socioeconómicas y el estilo de vida, con respecto al tabaquismo y al consumo de alcohol. Los resultados encontrados sugieren que los portadores del polimorfismo CYP2E1-c2, asociado con mayor actividad metabólica, tienen mayor riesgo a desarrollar cáncer gástrico (OR=3.6, CI95% 1.6-8.1/p=0,002. En contraste, la frecuencia del polimorfismo CYP1A1*2A (MspI, también asociado con mayor actividad enzimática, mostró similar frecuencia entre los dos grupos. El tabaquismo y el estrato socioeconómico bajo, también mostraron diferencias significativas. En conclusión, se evidencia interacción significativa entre gen-ambiente, particularmente entre el tabaquismo y los alelos bioactiavantes CYP2E1- c2 y CYP1A1-m2, que pueden alterar la susceptibilidad a cáncer de estómago en esta región Andina del noroeste de Sur América.

Direct reduction of 238PuO2 and 239PuO2 to metal

International Nuclear Information System (INIS)

Mullins, L.J.; Foxx, C.L.

1982-02-01

The process for reducing 700 g 239 PuO 2 to metal is a standard procedure at Los Alamos National Laboratory. This process is based on research for reducing 200 g 238 PuO 2 to metal. This report describes in detail the experiments and development of the 200-g process. The procedure uses calcium metal as the reducing agent in a molten CaCl 2 solvent system. The process to convert impure plutonia to high-purity metal by oxide reduction followed by electrorefining is also described

Polimorfismos en el gen promotor de IL-10 en una muestra de pacientes colombianos con lepra

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Nora Cardona-Castro

2012-03-01

Conclusiones. El haplotipo que encontramos asociado con lepra, -1082A-819C-592C/-1082A-819C-592C, se ha relacionado con baja producción de IL-10. Funcionalmente, esta baja producción de IL-10 puede tener consecuencias en la respuesta inmunitaria, además de implicaciones clínicas. Se han reportado diferentes haplotipos de IL-10 como marcadores de vulnerabilidad y resistencia de lepra en otras poblaciones, lo cual sugiere que las diferencias en la distribución de diversos polimorfismos del gen de IL-10 entre grupos étnicos, es un factor importante al determinar la asociación entre enfermedad y genes.   DOI: http://dx.doi.org/10.7705/biomedica.v32i1.386

Genotipificación de Plasmodium falciparum por PCR múltiple por medio de los genes msp1, msp2 y glurp, en cuatro localidades de Colombia

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Sandra Milena Barrera

2010-12-01

Conclusiones. Nuestros resultados demuestran que el marcador molecular msp1 no proporciona información útil para diferenciar las poblaciones parasitarias de P. falciparum. El gen msp2 es apropiado para evaluar la diversidad genética, pero requiere ensayos más finos que permitan diferenciar claramente el polimorfismo de tamaño en las dos familias. Los resultados obtenidos con el gen glurp evidenciaron una gran diversidad genética en las poblaciones de P. falciparum que circulan en el país y sugieren que este gen puede ser útil para diferenciar nuevas infecciones de infecciones recurrentes o recrudecimientos.

42 CFR 455.238 - Conflict of interest.

Science.gov (United States)

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Conflict of interest. 455.238 Section 455.238... Conflict of interest. (a) Offerors for Medicaid integrity audit program contracts, and Medicaid integrity audit program contractors, are subject to the following requirements: (1) The conflict of interest...

40 CFR 86.238-94-86.239-94 - [Reserved

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false [Reserved] 86.238-94-86.239-94 Section 86.238-94-86.239-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures §§ 86.238-94—86.239-94 [Reserved] ...

Variantes en los factores de transcripción para IFNγ, TBET, STAT1, STAT4 y HLX, y el riesgo de desarrollar tuberculosis pulmonar en un estudio de casos y controles de una población colombiana

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María Dulfary Sánchez

2013-06-01

Full Text Available Introducción. El interferón gama (IFNγ es la citocina más potente para controlar la infección por Mycobacterium tuberculosis, el agente etiológico de la tuberculosis humana. Los pacientes con tuberculosis activa presentan reducción de los niveles de IFNγ, lo cual parece explicar la inmunidad poco efectiva contra el bacilo. La disminución de su expresión o alteraciones funcionales de los factores transactivadores del promotor del gen de IFNγ, podrían explicar la reducción de los niveles de IFNγ enlos pacientes con tuberculosis. Objetivo. Determinar la asociación de variantes genéticas en los factores de transcripción TBET,STAT1, STAT4 y HLX con sensibilidad o resistencia a tuberculosis pulmonar. Materiales y métodos. Se seleccionaron ocho polimorfismos de un solo nucleótido (Single-NucleotidePolymorphism, SNP y se estableció su genotipo, en 466 pacientes con tuberculosis pulmonar y 300 controles sanos en Colombia; además, se hizo un análisis de asociación alélica y genética. Resultados. Los resultados indican que los SNP de los factores de transcripción estudiados no están asociados con tuberculosis; sin embargo, el polimorfismo rs11650354 en TBET puede estar implicado en la disminución de riesgo de tuberculosis. El genotipo TT de TBET se asoció significativamente con protección contra tuberculosis usando un modelo genético recesivo (OR=0,089; CI95%: 0,01-0,73;p=0,0069; sin embargo, la corrección mediante pruebas múltiples de ajuste abolió esta asociación (Empirical P Value, EMP2=0,61. Conclusión. En este estudio se sugiere un efecto de la variante rs11650354 de TBET sobre la resistencia a la tuberculosis en la población colombiana. Es necesario desarrollar un estudio de replicación usando muestras adicionales para confirmar esta asociación sugestiva. doi: http://dx.doi.org/10.7705/biomedica.v33i2.790

Fission Product Yields for 14 MeV Neutrons on 235U, 238U and 239Pu

International Nuclear Information System (INIS)

Mac Innes, M.; Chadwick, M.B.; Kawano, T.

2011-01-01

We report cumulative fission product yields (FPY) measured at Los Alamos for 14 MeV neutrons on 235 U, 238 U and 239 Pu. The results are from historical measurements made in the 1950s–1970s, not previously available in the peer reviewed literature, although an early version of the data was reported in the Ford and Norris review. The results are compared with other measurements and with the ENDF/B-VI England and Rider evaluation. Compared to the Laurec (CEA) data and to ENDF/B-VI evaluation, good agreement is seen for 235 U and 238 U, but our FPYs are generally higher for 239 Pu. The reason for the higher plutonium FPYs compared to earlier Los Alamos assessments reported by Ford and Norris is that we update the measured values to use modern nuclear data, and in particular the 14 MeV 239 Pu fission cross section is now known to be 15–20% lower than the value assumed in the 1950s, and therefore our assessed number of fissions in the plutonium sample is correspondingly lower. Our results are in excellent agreement with absolute FPY measurements by Nethaway (1971), although Nethaway later renormalized his data down by 9% having hypothesized that he had a normalization error. The new ENDF/B-VII.1 14 MeV FPY evaluation is in good agreement with our data.

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

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Jeane Eliete Laguila Visentainer

2008-12-01

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

Is tumor necrosis factor - 376a promoter polymorphism associated with susceptibility to multiple sclerosis? ¿El polimorfismo-376A del promotor del gen del factor de necrosis tumoral se asocia con una mayor susceptibilidad a padecer esclerosis múltiple?

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Marcelo A. Kauffman

2007-10-01

Full Text Available A single nucleotide polymorphism (SNP at position -376 of the tumor necrosis factor á gene (TNFA has been associated with susceptibility to multiple sclerosis (MS in Spain. However, no association was found in populations from the USA and The Netherlands. Here we investigate the association between the TNFA - 376A SNP and MS susceptibility in Argentinean patients with MS. The A/G genotype was found in 4.4% of patients (n=90 and in 4.8% of healthy individuals (n=84; p=0.92; odds ratio=0.93; confidence interval: 0.23- 3.84. Thus, no significant differences in genotype and allele frequencies were found between healthy individuals and patients with MS in Argentina.Un polimorfismo de nucleótido único (SNP, por sus iniciales en inglés en la posición -376 del gen codificante del factor de necrosis tumoral á (TNFA ha sido asociado en España con un mayor riesgo a padecer esclerosis múltiple (EM. Sin embargo, esta asociación no fue encontrada en estudios hechos en poblaciones provenientes de los EE.UU. y Holanda. Aquí investigamos la asociación entre el SNP TNFA -376A y el desarrollo de EM en una población de pacientes argentinos con EM. El genotipo A/G fue encontrado en 4.4% de los pacientes (n=90 y en 4.8% de los controles sanos (n=84; p=0.92; odds ratio=0.93; intervalo de confianza: 0.23-3.84. En consecuencia, no encontramos diferencias en las frecuencias alélicas y genotípicas entre los sujetos enfermos y los controles sanos en Argentina.

238Pu fuel form processes. Final report, January-September 1983

International Nuclear Information System (INIS)

Mosley, W.C.; Taylor, D.H.

1983-01-01

Progress is reported on the following: analytical studies of weld-quench cracking in DOP-26 iridium alloy, iridium/ 238 PuO 2 compatibility test, surface area measurements of 238 PuO 2 using the Blaine air permeability apparatus, and helium release from 238 PuO 2

IAEA CIELO Evaluation of Neutron-induced Reactions on 235U and 238U Targets

Science.gov (United States)

Capote, R.; Trkov, A.; Sin, M.; Pigni, M. T.; Pronyaev, V. G.; Balibrea, J.; Bernard, D.; Cano-Ott, D.; Danon, Y.; Daskalakis, A.; Goričanec, T.; Herman, M. W.; Kiedrowski, B.; Kopecky, S.; Mendoza, E.; Neudecker, D.; Leal, L.; Noguere, G.; Schillebeeckx, P.; Sirakov, I.; Soukhovitskii, E. S.; Stetcu, I.; Talou, P.

2018-02-01

Evaluations of nuclear reaction data for the major uranium isotopes 238U and 235U were performed within the scope of the CIELO Project on the initiative of the OECD/NEA Data Bank under Working Party on Evaluation Co-operation (WPEC) Subgroup 40 coordinated by the IAEA Nuclear Data Section. Both the mean values and covariances are evaluated from 10-5 eV up to 30 MeV. The resonance parameters of 238U and 235U were re-evaluated with the addition of newly available data to the existing experimental database. The evaluations in the fast neutron range are based on nuclear model calculations with the code EMPIRE-3.2 Malta above the resonance range up to 30 MeV. 235U(n,f), 238U(n,f), and 238U(n,γ) cross sections and 235U(nth,f) prompt fission neutron spectrum (PFNS) were evaluated within the Neutron Standards project and are representative of the experimental state-of-the-art measurements. The Standards cross sections were matched in model calculations as closely as possible to guarantee a good predictive power for cross sections of competing neutron scattering channels. 235U(n,γ) cross section includes fluctuations observed in recent experiments. 235U(n,f) PFNS for incident neutron energies from 500 keV to 20 MeV were measured at Los Alamos Chi-Nu facility and re-evaluated using all available experimental data. While respecting the measured differential data, several compensating errors in previous evaluations were identified and removed so that the performance in integral benchmarks was restored or improved. Covariance matrices for 235U and 238U cross sections, angular distributions, spectra and neutron multiplicities were evaluated using the GANDR system that combines experimental data with model uncertainties. Unrecognized systematic uncertainties were considered in the uncertainty quantification for fission and capture cross sections above the thermal range, and for neutron multiplicities. Evaluated files were extensively benchmarked to ensure good performance in

Behavior of uranium along Jucar River (Eastern Spain). Determination of 234U/238U and 235U/238U ratios

International Nuclear Information System (INIS)

Rodriguez-Alvarez, M.J.; Sanchez, F.

1995-01-01

The uranium concentration and the 234 U/ 238 U, 235 U/ 238 U activity ratios were studied in water samples from Jucar River, using low-level α-spectrometry. The effects of pH, temperature and salinity were considered and more detailed sampling was done in the neighbourhood of Cofrentes Nuclear Plant (Valencia, Spain). Changes were observed in the uranium concentration with the salinity and the 234 U/ 238 U activity ratio was found to vary with pH. Leaching and dilution, which depend on pH and salinity, are the probable mechanisms for these changes in the concentration of uranium and the activity ratios. (author) 25 refs.; 4 figs.; 1 tab

Determination of the isotopic ratio 234 U/238 U and 235 U/238 U in uranium commercial reagents by alpha spectroscopy

International Nuclear Information System (INIS)

Iturbe G, J.L.

1990-02-01

In this work the determination of the isotope ratio 234 U/ 238 U and 235 U/ 238 U obtained by means of the alpha spectroscopy technique in uranium reagents of commercial marks is presented. The analyzed uranium reagents were: UO 2 (*) nuclear purity, UO 3 (*) poly-science, metallic uranium, uranyl nitrate and uranyl acetate Merck, uranyl acetate and uranyl nitrate Baker, uranyl nitrate (*) of the Refinement and Conversion Department of the ININ, uranyl acetate (*) Medi-Lab Sigma of Mexico and uranyl nitrate Em Science. The obtained results show that the reagents that are suitable with asterisk (*) are in radioactive balance among the one 234 U/ 238 U, since the obtained value went near to the unit. In the case of the isotope ratio 235 U/ 238 U the near value was also obtained the one that marks the literature that is to say 0.04347, what indicates that these reagents contain the isotope of 235 U in the percentage found in the nature of 0.71%. The other reagents are in radioactive imbalance among the 234 U/ 238 U, the found values fluctuated between 0.4187 and 0.1677, and for the quotient of activities 235 U/ 238 U its were of 0.0226, and the lowest of 0.01084. Also in these reagents it was at the 236 U as impurity. The isotope of 236 U is an isotope produced artificially, for what is supposed that the reagents that are in radioactive imbalance were synthesized starting from irradiated fuel. (Author)

Capability to Recover Plutonium-238 in H-Canyon/HB-Line - 13248

Energy Technology Data Exchange (ETDEWEB)

Fuller, Kenneth S. Jr.; Smith, Robert H. Jr.; Goergen, Charles R. [Savannah River Nuclear Solutions, LLC, Savannah River Site, Aiken, SC 29802 (United States)

2013-07-01

Plutonium-238 is used in Radioisotope Thermoelectric Generators (RTGs) to generate electrical power and in Radioisotope Heater Units (RHUs) to produce heat for electronics and environmental control for deep space missions. The domestic supply of Pu-238 consists of scrap material from previous mission production or material purchased from Russia. Currently, the United States has no significant production scale operational capability to produce and separate new Pu-238 from irradiated neptunium-237 targets. The Department of Energy - Nuclear Energy is currently evaluating and developing plans to reconstitute the United States capability to produce Pu-238 from irradiated Np-237 targets. The Savannah River Site had previously produced and/or processed all the Pu-238 utilized in Radioisotope Thermoelectric Generators (RTGs) for deep space missions up to and including the majority of the plutonium for the Cassini Mission. The previous full production cycle capabilities included: Np- 237 target fabrication, target irradiation, target dissolution and Np-237 and Pu-238 separation and purification, conversion of Np-237 and Pu-238 to oxide, scrap recovery, and Pu-238 encapsulation. The capability and equipment still exist and could be revitalized or put back into service to recover and purify Pu-238/Np-237 or broken General Purpose Heat Source (GPHS) pellets utilizing existing process equipment in HB-Line Scrap Recovery, and H-Canyon Frame Waste Recovery processes. The conversion of Np-237 and Pu-238 to oxide can be performed in the existing HB-Line Phase-2 and Phase- 3 Processes. Dissolution of irradiated Np-237 target material, and separation and purification of Np-237 and Pu-238 product streams would be possible at production rates of ∼2 kg/month of Pu-238 if the existing H-Canyon Frames Process spare equipment were re-installed. Previously, the primary H-Canyon Frames equipment was removed to be replaced: however, the replacement project was stopped. The spare equipment

Diagnóstico genético de variantes polimórficas asociadas a la celiaquía, mediante ensayo de PCR múltiplex sobre los marcadores DQ2 y DQ8 (Práctica en laboratorio virtual Cibertorio)

OpenAIRE

Herráez, Angel

2017-01-01

Guión de trabajo para el laboratorio virtual «Cibertorio» en Biomodel.UAH.es Se habla de diversidad genética de los individuos como el resultado de que, en diversas regiones del genoma, unas personas tenemos secuencias de nucleótidos que nos diferencian de otras; esto se denomina polimorfismo genético. Cuando estas regiones polimórficas corresponden a zonas codificantes de un producto, existen consecuencias funcionales. El diagnóstico y el pronóstico de la enfermedad celíaca son compl...

Transplacental absorption of 238Pu in rats and guinea pigs

International Nuclear Information System (INIS)

Sullivan, M.F.

1980-01-01

Pregnant rats and guinea pigs were injected intravenously with 238 Pu citrate to determine if the potential for in utero accumulation of 238 Pu by these two species is related to the stage of development at which immunity is gained. Although guinea pigs retained more 238 Pu after birth than rats, the difference was not significant

17 CFR 230.238 - Exemption for standardized options.

Science.gov (United States)

2010-04-01

... options. 230.238 Section 230.238 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... Exemption for standardized options. (a) Exemption. Except as expressly provided in paragraphs (b) and (c) of this section, the Act does not apply to any standardized option, as that term is defined by section 240...

49 CFR 238.230 - Safety appliances-new equipment.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Safety appliances-new equipment. 238.230 Section... I Passenger Equipment § 238.230 Safety appliances—new equipment. (a) Applicability. This section..., 2007, that is equipped with a safety appliance, required by the “manner of application” provisions in...

Aspects of 238Pu production in the experimental fast reactor JOYO

International Nuclear Information System (INIS)

Osaka, Masahiko; Koyama, Shin-ichi; Tanaka, Kenya; Itoh, Masahiko; Saito, Masaki

2005-01-01

Experimental determination of 238 Pu in 237 Np samples irradiated in the experimental fast reactor JOYO was done as part of the demonstration of 238 Pu production from 237 Np in fast reactors within the framework of the protected Pu production project, which aims at reinforcement of proliferation resistance of Pu by increasing the 238 Pu isotopic ratio. 238 Pu production amount in the irradiated 237 Np samples was determined by a radioanalytical technique. Aspects of 238 Pu production were examined on the basis of the present radioanalysis. The 238 Pu production amount depends on the neutron spectrum which can range from that of a typical fast reactor to a nearly epi-thermal spectrum. It is concluded that the fast reactor has not only high potential for use in protected Pu production, but also as an incinerator for excess Pu

Associação de níveis plasmáticos de PAI-1 e polimorfismo 4G/5G em pacientes com doença arterial coronariana

Directory of Open Access Journals (Sweden)

Luciana Moreira Lima

2011-12-01

Full Text Available FUNDAMENTO: O polimorfismo 4G/5G do inibidor ativador do plasminogênio tipo 1 (PAI-1 pode influenciar a expressão do PAI-1. Níveis plasmáticos elevados de PAI-1 estão associados com Doença Arterial Coronariana (DAC. OBJETIVO: O presente estudo investigou a influência do polimorfismo 4G/5G do PAI-1 nos níveis plasmáticos de PAI-1 e sua associação com DAC avaliada por angiografia coronária. MÉTODOS: Foi avaliada amostra de sangue de 35 indivíduos com artérias coronárias angiograficamente normais, 31 indivíduos apresentando ateromatose leve/moderada, 57 indivíduos apresentando ateromatose grave e 38 indivíduos saudáveis (controles. Em pacientes e controles, o polimorfismo 4G/5G do PAI-1 foi determinado por amplificação da proteína-C reativa utilizando primers específicos de alelo. Os níveis plasmáticos de PAI-1 foram quantificados pelo ensaio ELISA (American Diagnostica. RESULTADOS: Não houve diferença entre os grupos quanto a sexo, idade e índice de massa corporal. Níveis plasmáticos de PAI-1 e frequência do genótipo 4G/4G mostravam-se significativamente maiores no grupo com ateromatose grave em comparação com os outros grupos (p 70% (p < 0,001. CONCLUSÃO: O achado mais importante deste estudo foi a associação entre o genótipo 4G/4G, elevados níveis plasmáticos de PAI-1 e estenose coronariana superior a 70% em indivíduos brasileiros. Ainda não foi estabelecido se elevados níveis plasmáticos de PAI-1 são um fator decisivo para o agravamento da aterosclerose ou se são uma consequência.

238U, 234U and 232Th in seawater

International Nuclear Information System (INIS)

Chen, J.H.; Edwards, R.L.; Wasserburg, G.J.

1986-01-01

We have developed techniques to determine 238 U, 234 U and 232 Th concentrations in seawater by isotope dilution mass spectrometry. Using these techniques, we have measured 238 U, 234 U and 232 Th in vertical profiles of unfiltered, acidified seawater from the Atlantic and 238 U and 234 U in vertical profiles from the Pacific. Determinations of 234 U/ 238 U at depths ranging from 0 to 4900 m in the Atlantic (7 0 44'N, 40 0 43'W) and the Pacific (14 0 41'N, 160 0 01'W) Oceans are the same within experimental error (±5per mille, 2σ). The average of these 234 U/ 238 U measurements is 144±2per mille (2σ) higher than the equilibrium ratio of 5.472 x 10 -5 . U concentrations, normalized to 35per mille salinity, range from 3.162 to 3.281 ng/g, a range of 3.8%. The average concentration of the Pacific samples (31 0 4'N, 159 0 1'W) is ∝1% higher than that of the Atlantic (7 0 44'N, 40 0 43'W and 31 0 49'N, 64 0 6'W). 232 Th concentrations from an Atlantic profile range from 0.092 to 0.145 pg/g. The observed constancy of the 234 U/ 238 U ratio is consistent with the predicted range of 234 U/ 238 U using a simple two-box model and the residence time of deep water in the ocean determined from 14 C. The variation in salinity-normalized U concentrations suggests that U may be much more reactive in the marine environment than previously thought. (orig./WB)

Genetic variability of the inflammatory response. I. The -511 C/T IL1β polymorphism in different Peruvian subpopulations

OpenAIRE

Acosta, Oscar; Solano, Luis; Huerta, Doris; Oré, Daniel; Sandoval, José; Figueroa, José; Fujita, Ricardo

2012-01-01

El polimorfismo -511 citosina/timina (-511 C/T) en la región promotora del gen interleuquina 1 beta (IL1β) está implicado en la producción diferencial de la citoquina y por tanto puede estar asociado a la respuesta inmuno-inflamatoria en obesidad, dislipidemias, cardiopatías, cáncer, infecciones, y el tratamiento con nutrientes y fármacos. Objetivos: Establecer la distribución de frecuencias de los genotipos y alelos del polimorfismo -511 C/T del gen IL1β en diferentes subpoblaciones peruanas...

Single nucleotide polymorphisms (SNPs at CDH1 promoter region in familial gastric cancer Polimorfismos de nucleótido único (SNPs en la región promotora CDH1 en cáncer gástrico familiar

Directory of Open Access Journals (Sweden)

A. Ramos-de la Medina

2006-01-01

han sido descritas en relación al desarrollo de cáncer gástrico difuso hereditario en pacientes jóvenes. Métodos: la secuencia codificadora completa exones 1 al 16 y la región promotora de CDH1 fueron amplificadas mediante reacción en cadena de la polimerasa en muestras de sangre periférica de dos pacientes con diagnósticos de cáncer gástrico de aparición temprana familiar. Resultados: en ninguno de los 2 pacientes se detectaron mutaciones germinales inactivadoras de CDH1. Se encontraron polimorfismos de nucleotido único C→A en la región promotora de CDH1 en la posición -160 en ambos pacientes. Conclusiones: el polimorfismo -160 C→A confiere teóricamente un aumento en el riesgo de desarrollar cáncer gástrico difuso. Los miembros de las familias presentan un riesgo mayor para cáncer gástrico difuso al igual que otras neoplasias. No existe actualmente evidencia suficiente para considerar al polimorfismo -160 C→A como un factor etiológico determinante de cáncer gástrico difuso debido a que la frecuencia y tipo de alteraciones en el gen CDH1 en población mexicana se desconocen. Será necesario llevar a cabo estudios epidemiológicos en población mexicana que determinen la influencia de diversas alteraciones genéticas en la génesis de esta neoplasia.

16 CFR 238.0 - Bait advertising defined. 1

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Bait advertising defined. 1 238.0 Section... BAIT ADVERTISING § 238.0 Bait advertising defined. 1 1 For the purpose of this part “advertising” includes any form of public notice however disseminated or utilized. Bait advertising is an alluring but...

Toxicity of inhaled 238PuO2 II

International Nuclear Information System (INIS)

Muggenburg, B.A.; Mewhinney, J.A.; Merickel, B.S.; Boecker, B.B.; Hahn, F.F.; Guilmette, R.A.; Mauderly, J.L.; McClellan, R.O.

1980-01-01

Studies are in progress to determine dose-response relationships for inhaled 238 PuO 2 . Beagle dogs were given a single, brief, nose-only inhalation exposure to aerosols of monodisperse particles of 238 PuO 2 . Aerosols of two sizes were used, 1.5 μm aerodynamic diameter (AD) and 3.0 μm AD. Dogs were exposed to achieve initial lung burdens of 0.56, 0.28, 0.14, 0.07, 0.03 or 0.01 μCi 238 PuO 2 /kg body weight. Twelve dogs were exposed at each activity level to each aerosol particle size. The local dose around each 3.0 μm AD particle was 10 times higher than the local dose around 1.5 μm AD particles, but the dose averaged over the whole lung was the same at each activity level for both particle sizes. The lung retention of 238 Pu was divided into two phases of clearance. During the first 100 days after exposure, the average retention half-time for 238 Pu in the lung was 310 days. When the solubility changed due to particle breakup, the retention half-time decreased to 180 days during the period from 1OO to 1,500 days after exposure. The first biological effects observed were lymphopenia and neutropenia in peripheral blood. To date, 28 Beagle dogs have died at times from 536 to 1683 days after exposure. Initial lung burdens for the dead dogs ranged from 0.18 to 2.2 μCi 238 Pu/kg body weight. Nine died with radiation pneumonitis and pulmonary fibrosis, 10 died with lung tumors and 19 dogs died with bone tumors. There are 116 exposed and 22 control dogs surviving and under observation. Current patterns of dose versus response are discussed. (author)

49 CFR 238.207 - Link between coupling mechanism and car body.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Link between coupling mechanism and car body. 238.207 Section 238.207 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... Requirements for Tier I Passenger Equipment § 238.207 Link between coupling mechanism and car body. All...

Diversidad genética, entre y dentro de los mayores grupos humanos

Directory of Open Access Journals (Sweden)

Barbujani, G.

2003-01-01

Full Text Available Varios estudios están de acuerdo cuando reportan que cerca del 85% de la diversidad del ADN autosomal y de los loci de las proteínas se debe a diferencias entre individuos dentro de la misma población, mientras que las diferencias entre los grupos de diferentes continentes son responsables de solamente 10% de la variación genética total. Estos resultados están en conflicto con nociones populares de razas humanas claramente distintas y relativamente homogéneas, y nos hacen cuestionar la utilidad de clasificaciones étnicas en diagnósticos médicos, en el campo forense y en genética farmacológica. Nuevos datos obtenidos de inserciones polimórficas de Alu y del cromosoma Y confirman los resultados previos, aunque indican una diversidad mayor en algunos (pero no todos los loci del cromosoma Y. Estos datos nos permiten investigar dos preguntas: (1 si las diferencias continentales, aunque pequeñas, son suficientemente grandes como para asignar a individuos a sus continentes basados en sus genotipos; (2 si los genotipos observados se agrupan en grupos de población o continentales cuando el origen de la muestra se ignora. Usando varios métodos estadísticos, veremos que los errores de clasificación son por lo menos de un 30% para los polimorfismos autosomales bi-alélicos, y de un 27% para el cromosoma Y. Cuatro series de datos genéticos de todo el mundo sugieren la existencia de grupos de genotipos diferentes, pero que éstos cuatro grupos no coinciden el uno con el otro. Adicionalmente, estudios de bloques de ADN del genoma humano indican que la mayor parte de dichos bloques es compartida entre los continentes, con solamente un pequeño porcentaje siendo específico a ciertos continentes. Estos resultados no indican que haya una base clara para subdividir a los humanos en grupos biológicamente definidos. Este puede no ser un problema en áreas aplicadas de genéticas, dado que los métodos rápidos para obtener genotipos individuales

Containment of Nitric Acid Solutions of Plutonium-238

International Nuclear Information System (INIS)

Reimus, M.A.H.; Silver, G.L.; Pansoy-Hjelvik, L.; Ramsey, K.

1999-01-01

The corrosion of various metals that could be used to contain nitric acid solutions of Pu-238 has been studied. Tantalum and tantalum/2.5% tungsten resisted the test solvent better than 304L stainless steel and several INCONEL alloys. The solvent used to imitate nitric acid solutions of Pu-238 contained 70% nitric acid, hydrofluoric acid, and ammonium hexanitratocerate

Present status of radiochemical double β decay study (238U)

International Nuclear Information System (INIS)

Chevallier, A.; Chevallier, J.; Escoubes, B.; Schulz, N.; Sens, J.C.; Madic, C.; Maillard, C.

1989-01-01

The reasons for which the 238 U is a suitable candidate for the β β decay processes are explained. The strategy adopted for the radiochemical separation of the 234 U is given. A chemical system based on extraction chromatography is applied. The Pu IV breakthrough curves obtained at 40C during 238 Pu/ 238 U separation cycles are presented. A short description of the chromatographic facility is given. The solution adopted for the low background α spectrometer is explained

Polimorfismos genéticos e desempenho físico em jogadores de futebol das categorias de base do São Paulo Futebol Clube

OpenAIRE

Thiago José Dionísio

2014-01-01

Há relatos na literatura de que os polimorfismos genéticos podem determinar importantes modulações nos fenótipos dos atletas, como por exemplo, estatura, adaptações cardiovasculares, utilização dos substratos energéticos bem como balanço eletrolítico e hormonal. É possível que indivíduos que expressem o gene alfa actinina 3 (ACTN3; genótipos RR para homozigotos ancestrais ou RX para heterozigotos) possam apresentar vantagens em movimentos que exijam força e rápida contração muscular quando co...

Determination of the isotopic ratio {sup 234} U/{sup 238} U and {sup 235} U/{sup 238} U in uranium commercial reagents by alpha spectroscopy; Determinacion de la relacion isotopica {sup 234} U/{sup 238} U y {sup 235} U/{sup 238} U en reactivos comerciales de uranio por espectrometria alfa

Energy Technology Data Exchange (ETDEWEB)

Iturbe G, J L

1990-02-15

In this work the determination of the isotope ratio {sup 234} U/{sup 238} U and {sup 235} U/{sup 238} U obtained by means of the alpha spectroscopy technique in uranium reagents of commercial marks is presented. The analyzed uranium reagents were: UO{sub 2} (*) nuclear purity, UO{sub 3} (*) poly-science, metallic uranium, uranyl nitrate and uranyl acetate Merck, uranyl acetate and uranyl nitrate Baker, uranyl nitrate (*) of the Refinement and Conversion Department of the ININ, uranyl acetate (*) Medi-Lab Sigma of Mexico and uranyl nitrate Em Science. The obtained results show that the reagents that are suitable with asterisk (*) are in radioactive balance among the one {sup 234} U/{sup 238} U, since the obtained value went near to the unit. In the case of the isotope ratio {sup 235} U/{sup 238} U the near value was also obtained the one that marks the literature that is to say 0.04347, what indicates that these reagents contain the isotope of {sup 235} U in the percentage found in the nature of 0.71%. The other reagents are in radioactive imbalance among the {sup 234} U/{sup 238} U, the found values fluctuated between 0.4187 and 0.1677, and for the quotient of activities {sup 235} U/{sup 238} U its were of 0.0226, and the lowest of 0.01084. Also in these reagents it was at the {sup 236} U as impurity. The isotope of {sup 236} U is an isotope produced artificially, for what is supposed that the reagents that are in radioactive imbalance were synthesized starting from irradiated fuel. (Author)

Multimode approximation for {sup 238}U photofission at intermediate energies

Energy Technology Data Exchange (ETDEWEB)

Demekhina, N. A., E-mail: demekhina@lnr.jinr.ru [Yerevan Physics Institute (Armenia); Karapetyan, G. S. [Yerevan State University (Armenia)

2008-01-15

The yields of products originating from {sup 238}U photofission are measured at the bremsstrahlung endpoint energies of 50 and 3500 MeV. Charge and mass distributions of fission fragments are obtained. Symmetric and asymmetric channels in {sup 238}U photofission are singled out on the basis of the model of multimode fission. This decomposition makes it possible to estimate the contributions of various fission components and to calculate the fissilities of {sup 238}U in the photon-energy regions under study.

226Ra/238U disequilibrium in an upland organic soil exhibiting elevated natural radioactivity

International Nuclear Information System (INIS)

Dowdall, M.; O'Dea, J.

2002-01-01

This paper presents the results of a study into the anomalous 226 Ra/ 238 U disequilibrium ( 226 Ra/ 238 U of 0.5-9) exhibited by an upland organic soil in Co. Donegal, Ireland. Radiochemical speciation of 226 Ra, 238 U and 228 Ra indicates that in this organic soil the high 226 Ra/ 238 U ratio is due to loss of 238 U relative to 226 Ra via oxidation and mobilisation of 238 U in the upper layers of the soil and subsequent loss in solution. At the lower, more reducing depths of the soil profile, 238 U and 226 Ra are essentially in equilibrium. Loss of 238 U appears to occur primarily from the easily oxidised organic and iron oxide fractions of the soil, samples exhibiting high 226 Ra/ 238 U ratios displaying significantly lower 238 U levels in these fractions than samples whose ratio is below the average value for the soil of the valley. Selective enrichment of 226 Ra by plants or preferential leaching of 226 Ra from the underlying rock is not supported by the results of this study

Sub-barrier photofission of 238U

International Nuclear Information System (INIS)

Bhandari, B.S.

Photofission cross section of 238 U below threshold have been calculated using a double humped potential barrier parameterized by smoothly joining four parabolas, and a coulomb potential at and beyond the scission point. Relative strength in the fission channel has been calculated and an attempt has been made to interpret the apparent resonance structures observed recently in photofission experiments of 238 U as excited states of the fission isomer. A set of parameters for a double humped barrier are found which are consistent with known spontaneous fission and isomeric fission half lives. In addition to reproducing satisfactorily the observed resonance structure near threshold, the calculation also predicts several low energy resonances in the cross sections [pt

Present status of radiochemical double beta decay study (238U)

International Nuclear Information System (INIS)

Madic, C.; Maillard, C.; Chevallier, A.; Chevallier, J.; Escoubes, B.; Schulz, N.; Sens, J.C.

1989-01-01

A sensitive experiment has been designed that will be able to measure an assumed half-life of 1.9x10 22 yr. This double beta corresponds to the activity of 27000 238 Pu nuclei formed during a year, in a 200 m deep mine, from 300 kg of 238 U, giving 210 alpha decays per year. Plutonium 238 et 239 will be determined by alpha spectroscopy after extraction chromatography. Experimental studies were undertaken to select the best conditions for running the extraction chromatography cycles

49 CFR 238.413 - End structures of trailer cars.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false End structures of trailer cars. 238.413 Section... II Passenger Equipment § 238.413 End structures of trailer cars. (a) Except as provided in paragraph (b) of this section, the end structure of a trailer car shall be designed to include the following...

Heterogeneity in the 238U/235U Ratios of Angrites.

Science.gov (United States)

Tissot, F.; Dauphas, N.; Grove, T. L.

2016-12-01

Angrites are differentiated meteorites of basaltic composition, of either volcanic or plutonic origin, that display minimal post-crystallization alteration, metamorphism, shock or impact brecciation. Because quenched angrites cooled very rapidly, all radiochronometric systems closed simultaneously in these samples. Quenched angrites are thus often used as anchors for cross-calibrating short-lived dating methods (e.g., 26Al-26Mg) and the absolute dating techniques (e.g, Pb-Pb). Due to the constancy of the 238U/235U ratio in natural samples, Pb-Pb ages have long been calculated using a "consensus" 238U/235U ratio, but the discovery of resolvable variations in the 238U/235U ratio of natural samples, means that the U isotopic composition of the material to date also has to be determined in order to obtain high-precision Pb-Pb ages. We set out (a) to measure at high-precision the 238U/235U ratio of a large array of angrites to correct their Pb-Pb ages, and (b) to identify whether all angrites have a similar U isotopic composition, and, if not, what were the processes responsible for this variability. Recently, Brennecka & Wadhwa (2012) suggested that the angrite-parent body had a homogeneous 238U/235U ratio. They reached this conclusion partly because they propagated the uncertainties of the U isotopic composition of the various U double spikes that they used onto the final 238U/235U ratio the sample. Because this error is systematic (i.e., it affects all samples similarly), differences in the δ238U values of samples corrected by the same double spike are better known than one would be led to believe if uncertainties on the spike composition are propagated. At the conference, we will present the results of the high-precision U isotope analyses for six angrite samples: NWA 4590, NWA 4801, NWA 6291, Angra dos Reis, D'Orbigny, and Sahara 99555. We will show that there is some heterogeneity in the δ238U values of the angrites and will discuss the possible processes by

Interception and retention of 238Pu deposition by orange trees

International Nuclear Information System (INIS)

Pinder, J.E. III; Adriano, D.C.; Ciravolo, T.G.; Doswell, A.C.; Yehling, D.M.

1987-01-01

Radioisotope thermoelectric generators (RTG) transform the heat produced during the alpha decay of 238 Pu into electrical energy for use by deep-space probes, such as the Voyager spacecraft, which have returned images and other data from Jupiter, Saturn and Uranus. Future missions involving RTGs may be launched aboard the space shuttle, and there is a remote possibility that an explosion of liquid-hydrogen and liquid-oxygen fuel could rupture the RTGs and disperse 238 Pu into the atmosphere over central Florida. Research was performed to determine the potential transport to man of atmospherically dispersed Pu via contaminated orange fruits. The results indicate that the major contamination of oranges would result from the interception and retention of 238 Pu deposition by fruits. The resulting surface contamination could enter human food chains through transfer to internal tissues during peeling or in the reconstituted juices and flavorings made from orange skins. The interception of 238 Pu deposition by fruits is especially important because the results indicate no measurable loss of Pu from fruit surfaces through time or with washing. Approximately 1% of the 238 Pu deposited onto an orange grove would be harvested in the year following deposition

Phenotypic polomorphism in indigenous strains of sporothrix schenckii Polimorfismo fenotípico de cepas autóctonas de Sporothrix schenckii

Directory of Open Access Journals (Sweden)

Fernando Montoya Maya

1996-02-01

características de pigmentación. El 85% de las cepas en mycosel fueron café claras, café oscuras, plisadas o plisadas y umbilicadas. Todas las cepas asimilaron D-glucosa, glicerol y D-xilosa en el sistema Api 20C y 25 cepas se clasificaron en 9 biotipos de asimilación de la A a la I. La mayoría de las cepas tanto pigmentadas como albinas, resultaron virulentas para ratones. En éstos predominaron los cuerpos en cigarro en forma de naveta y no se visual izaron cuerpos asteroides en los exudados testiculares. Se demuestra así la gran heterogeneidad fenotípica de las cepas autóctonas de S. schenckii, se plantea la importancia de correlacionar estos hallazgos con los patrones de heterogeneidad gen ética informados por investigadores Japoneses y quizás explicar por esta diversidad fenotípica y genotípica, el polimorfismo clínico de la enfermedad y establecer mapas de distribución de los diferentes biotipos o genotipos en Colombia y América Latina. Incluso el cruzar cepas distantes en su biotipo o genotipo podría facilitar la obtención de la forma de reproducción sexual del microorganismo.

Double beta decay of Uranium-238: Proton reactions of 238U in 5--12 MeV range. Final report, April 15, 1987--March 31, 1992

International Nuclear Information System (INIS)

Turkevich, A.; Economou, T.E.

1993-01-01

This report is in two parts. The first part reports on the experimental work determining the half-life for double beta decay of 238 U to 238 PU to be (2.0 ± 0.6) x 10 21 years. This is the first evidence for a third mode of decay of this heaviest naturally occurring nucleus. This rate is about 10 6 times slower than spontaneous fission, which itself is about 10 6 times slower than alpha decay. The implication of this double beta decay to neutrino masses depends on uncertain theoretical calculations of the rate for such a heavy nucleus. The second part reports on yields of principal fission products from 5.6, 7.3, 9.4, and 11.5 MeV proton interactions with 238 U. The yields at 11.5 MeV are similar to those from 14 MeV neutron fission of 238 U. At the same time, the production cross sections of 238 Np at the same energies are determined. This nuclide is produced as often as fission at the lowest energy but only 3.8% as often at the highest energy

40 CFR 238.20 - Definitions.

Science.gov (United States)

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING DEGRADABLE PLASTIC RING CARRIERS General Provisions § 238.20 Definitions. For the purpose of this part: Percent elongation at break means the percent increase in length of the plastic material caused by a tensile load. Percent...

Novos polimorfismos no gene da obesidade em raças divergentes de suínos Polymorphisms in the leptin gene in divergent swine breeds

Directory of Open Access Journals (Sweden)

M.A.M. Soares

2006-06-01

Full Text Available Investigou-se a existência de polimorfismo no gene da leptina (gene da obesidade entre varrões da raça nativa Piau (porco tipo banha e matrizes mestiças de raças comerciais (Landrace/Large White e Landrace/Large White com Pietrain, selecionadas para peso e precocidade. Oito pares de primers foram desenhados a partir da seqüência disponível no GenBank (U66254, usada, neste trabalho, como seqüência de referência. Amostras de DNA foram extraídas de células sangüíneas brancas utilizando-se solução de fenol:clorofórmio, após tratamento com proteinase K. Os fragmentos gerados por amplificação da reação em cadeia da polimerase foram purificados e seqüenciados em seqüenciador automático. As seqüências de nucleotídeos, obtidas a partir do DNA das raças comerciais de suíno, apresentaram maior similaridade com a seqüência de referência, e as seqüências geradas a partir do DNA dos animais nativos divergiram de ambas em algumas posições. Dos 28 polimorfismos encontrados, oito foram observados em apenas uma das três seqüências geradas a partir do DNA das raças nativas. Doze estavam presentes em duas seqüências, e os oito polimorfismos restantes foram encontrados nos três animais nativos.Leptin gene (obese gene polymorphism was investigated in Piau boars (a fat, native breed and sows from commercial strains (Landrace/Large White and Landrace/Large White by Pietrain chosen for rapid growth and early sexual maturity. Eight pairs of primers designed using the sequence available from GenBank (access nº U66254 were identified as the reference sequence in this project. DNA samples were extracted from white blood cells using phenol:chloroform solution, after treatment with proteinase K. Fragments generated by amplification of the Polymerase Chain Reaction were purified and sequenced in an automatic sequencer. Nucleotide sequences obtained from DNA of commercial swine breeds were similar to the reference sequence; whereas

Distribution of 238Pu in tissues of fish from the canal in Miamisburg, Oho

International Nuclear Information System (INIS)

Kennedy, C.W.; Bartelt, G.E.

1978-01-01

The 238 Pu concentrations of varous tissues were measured for seven species of freshwater fish from an ecosystem containing elevated levels of 238 Pu. The highest levels of 238 Pu were found in the gastrointestinal tracts and gills, while the lowest levels were found in muscle tissue. A rapid uptake of 238 Pu was observed for hatchery bluegills introduced into this system. High plutonium concentrations in the gastrointestinal tracts and gills suggest that these organs are potential uptake sites. The presence of 238 Pu in certain tissues (liver, gonads, bone, and muscle) indicates that there is a translocation of 238 Pu from the uptake sites

Medicina genómica: Aplicaciones del polimorfismo de un nucleótido y micromatrices de ADN Genomic Medicine: Polymorphisms and microarray applications

Directory of Open Access Journals (Sweden)

Monica P. Spalvieri

2004-12-01

Full Text Available Esta actualización tiene por objeto difundir un nuevo enfoque de las variaciones del ADN entre individuos y comentar las nuevas tecnologías para su detección. La secuenciación total del genoma humano es el comienzo para conocer la diversidad genética. La unidad de medida reconocida de esta variabilidad es el polimorfismo de un solo nucleótido (single nucleotide polymorphism o SNP. El estudio de los SNPs está restringido a la investigación pero las numerosas publicaciones sobre el tema hacen vislumbrar su entrada en la práctica clínica. Se presentan ejemplos del uso de SNPs como marcadores moleculares en la genotipificación étnica, la expresión génica de enfermedades y como potenciales blancos farmacológicos. Se comenta la técnica de las matrices (arrays que facilita el estudio de múltiples secuencias de genes mediante chips de diseño específico. Los métodos convencionales analizan hasta un máximo de 20 genes, mientras que una sola micromatriz provee información sobre decenas de miles de genes simultáneamente con una genotipificación rápida y exacta. Los avances de la biotecnología permitirán conocer, además de la secuencia de cada gen, la frecuencia y ubicación exacta de los SNPs y su influencia en los comportamientos celulares. Si bien la validez de los resultados y la eficiencia de las micromatrices son aún controvertidos, el conocimiento y caracterización del perfil genético de un paciente impulsará seguramente un cambio radical en la prevención, diagnóstico, pronóstico y tratamiento de las enfermedades humanas.This update shows new concepts related to the significance of DNA variations among individuals, as well as to their detection by using a new technology. The sequencing of the human genome is only the beginning of what will enable us to understand genetic diversity. The unit of DNA variability is the polymorphism of a single nucleotide (SNP. At present, studies on SNPs are restricted to basic research

Precisiones histológicas y bioquímicas acerca de los ejemplares de Frenelopsis procedentes de Torrelaguna (Madrid

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Álvarez Ramis, C.

1984-04-01

Full Text Available Different morphological features of the Frenelopsis from a Torrelaguna bassin (Madrid, Spain are described and compared with F. alata and F. oligostomata , studied by other authors. The Frenelopsis rests present, in the studied deposit, a remarkable polymorphism with respect 10 the dimensions of the leaves, but all the specimens studied are greatiy related to F. oligostomata . The chemical study of the organic constituents of the cutic1es shows a heterogeneous composition, being the major constituents an alkali-insoluble cutinized residue and a likehumic acid polyphenolic extractable fraction, Cuticles contains a certain proportion of a highly alterated lignin-like polymer, and minimal amounts of fulvic acids, nitrogenated compounds, free hydrocarbons and carbohydrates. KEY WORDS: Hystology, Biochemistry, Frenelopsis, Upper cretaceous, Palaeobotany, Humic substances.

Son descritos diferentes aspectos morfológicos de los Frenelopsis del yacimiento de Torrelaguna, comparándose sus características con las descritas por otros autores para las especies F. alata y F. oligostomata . Los restos de Frenelopsis presentan, en el yacimiento estudiado, un notable polimorfismo respecto a las dimensiones del fronde; pero todos los ejemplares descritos poseen características muy similares a las de F. oligostomata . El estudio químico de los constituyentes orgánicos de las cutículas muestra una composición compleja, siendo los componentes mayoritarios un residuo cutinizado insoluble en álcalis y una fracción polifenólica extraíble de características similares a los ácidos húmicos. Los restos presentan una cierta proporción de polímeros similares a la lignina, aunque muy alterada, así como pequeñas cantidades de ácidos fúlvicos, compuestos nitrogenados, hidrocarburos libres y carbohidratos.

Savannah River Laboratory monthly report: 238Pu fuel form processes

International Nuclear Information System (INIS)

1976-01-01

Progress in the Savannah River 238 Pu Fuel Form Program is discussed. Goals of the Savannah River Laboratory (SRL) program are to provide technical support for the transfer of the 238 Pu fuel form fabrication operations from Mound Laboratory to new facilities being built at the Savannah River Plant (SRP), to provide the technical basis for 238 Pu scrap recovery at SRP, and to assist in sustaining plant operations. During the period it was found that the density of hot-pressed 238 PuO 2 pellets decreased as the particle size of ball-milled powder decreased;the surface area of calcined 238 PuO 2 powder increased with increasing precipitation temperature and may be related to the variation in ball-milling response observed among different H Area B-Line batches; calcined PuO 2 produced by Pu(III) reverse-strike precipitation was directly fabricated into a pellet without ball milling, slugging, or sharding. The pellet had good appearance with acceptable density and dimensional stability, and heat transfer measurements and calculations showed that the use of hollow aluminum sleeves in the plutonium fuel fabrication (PuFF) storage vault reduced the temperature of shipping cans to 170 0 C and will reduce the temperature at the center of pure plutonium oxide (PPO) spheres to 580 0 C

Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

Science.gov (United States)

Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.; VanPelt, C. E.; Reimus, M. A.; Spengler, D.; Matonic, J.; Garcia, L.; Rios, E.; Sandoval, F.; Herman, D.; Hart, R.; Ewing, B.; Lovato, M.; Romero, J. P.

2005-02-01

Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt as the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium.

Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

International Nuclear Information System (INIS)

Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.; VanPelt, C. E.; Reimus, M. A.; Spengler, D.; Matonic, J.; Garcia, L.; Rios, E.; Sandoval, F.; Herman, D.; Hart, R.; Ewing, B.; Lovato, M.; Romero, J. P.

2005-01-01

Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt as the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium

Fission fragment yields and total kinetic energy release in neutron-induced fission of235,238U,and239Pu

Science.gov (United States)

Tovesson, F.; Duke, D.; Geppert-Kleinrath, V.; Manning, B.; Mayorov, D.; Mosby, S.; Schmitt, K.

2018-03-01

Different aspects of the nuclear fission process have been studied at Los Alamos Neutron Science Center (LANSCE) using various instruments and experimental techniques. Properties of the fragments emitted in fission have been investigated using Frisch-grid ionization chambers, a Time Projection Chamber (TPC), and the SPIDER instrument which employs the 2v-2E method. These instruments and experimental techniques have been used to determine fission product mass yields, the energy dependent total kinetic energy (TKE) release, and anisotropy in neutron-induced fission of U-235, U-238 and Pu-239.

16 CFR 238.2 - Initial offer.

Science.gov (United States)

2010-01-01

... § 238.2 Initial offer. (a) No statement or illustration should be used in any advertisement which creates a false impression of the grade, quality, make, value, currency of model, size, color, usability...

Pu-238 Supply Program Project Execution Plan

International Nuclear Information System (INIS)

Wham, Robert M.; Martin, Sherman

2012-01-01

This Pu-238 Supply Program Project Execution Plan (PEP) summarizes critical information and processes necessary to manage the program. The PEP is the primary agreement regarding planning and objectives between The Department of Energy Office of Nuclear Energy (DOE NE-75), Oak Ridge National Laboratory Site Office (OSO) and the Oak Ridge National Laboratory (ORNL). The acquisition executive (AE) will approve the PEP. The PEP is a living document that will be reviewed and revised periodically until the project is complete. The purpose of the project is to reestablish the capability to produce plutonium-238 (Pu-238) domestically. This capability consists primarily of procedures, processes, and design information, not capital assets. As such, the project is not subject to the requirements of DOE O 413.3B, but it will be managed using the project management principles and best practices defined there. It is likely that some capital asset will need to be acquired to complete tasks within the project. As these are identified, project controls and related processes will be updated as necessary. Because the project at its initiation was envisioned to require significant capital assets, Critical Decision 0 (CD-0) was conducted in accordance with DOE O 413.3B, and the mission need was approved on December 9, 2003, by William Magwood IV, director of the Office of Nuclear Energy (NE), Science and Technology, DOE. No date was provided for project start-up at that time. This PEP is consistent with the strategy described in the June 2010 report to Congress, Start-up Plan for Plutonium-238 Production for Radioisotope Power Systems.

temprana. Un enfoque analítico en un estudio piloto

Directory of Open Access Journals (Sweden)

Gloria Garavito

2013-01-01

Full Text Available Objetivos: Identificar biomarcadores de susceptibilidad para AIJ poliarticular y AR de instalación temprana por estudio del polimorfismos de MHC/HLA-DRB1* y PTPN22. Materiales y métodos: Se realizó un estudio de casos y controles con una relación 1:2. Todos los sujetos de investigación y los controles provinieron de una corta anidada perteneciente a un proyecto institucional; 30 pacientes con AIJ y 30 con AR de instalación temprana. Como controles se estudiaron 60 individuos sanos. El ADN se obtuvo por salt- ing out modificado. La tipificación de los alelos MHC/DRB1* se realizó por PCR-SSP y en el polimorfismo (C1858T del sistema PTPN22 se utilizó PCR-RTq. Resultados: Para AIJ Poliarticular, el alelo DRB1*0404 se asoció con susceptibilidad (OR=10.82; p<0.05, en el grupo con AR de instalación temprana, DRB1*0101 se mostró como marcador de susceptibilidad (OR=4.04; p<0.05. Se destaca que el alelo HLA- DRB1*0701 aparece como marcador protector para ambas patologías (OR=0,15; p<0,05. El polimorfismo del SNP (C1858T PTPN22 no se asoció con AIJ Poliarticular. En con- traste, en AR de instalación temprana, el Alelo CC se asoció con protección p<0.05. En el mismo grupo, CT/TT se mostró como un marcador de susceptibilidad <0.05. El análisis de la secuencia aminoacídica 70QRRAA74 del epítope compartido se asoció con susceptibili- dad para ambas entidades (p<0.05 y la secuencia 70DRRGQ74 con protección en ambos grupos de pacientes (p<0.05. Conclusión: Se destaca que en la asociación con la secuencia del epítope compartido, la ubicación del tipo de aminoácido y posición del mismo define probable asociación como marcador molecular de susceptibilidad en ambas entidades. Los polimorfismos comparti- dos sugieren un origen genético común para ambas entidades.

The Characterization of Biotic and Abiotic Media Upgradient and Downgradient of the Los Alamos Canyon Weir

International Nuclear Information System (INIS)

P.R. Fresquez

2006-01-01

As per the Mitigation Action Plan for the Special Environmental Analysis of the actions taken in response to the Cerro Grande Fire, sediments, vegetation, and small mammals were collected directly up- and downgradient of the Los Alamos Canyon weir, a low-head sediment control structure located on the northeastern boundary of Los Alamos National Laboratory, to determine contaminant impacts, if any. All radionuclides ( 3 H, 137 Cs, 238 Pu, 239,240 Pu, 90 Sr, 241 Am, 234 U, 235 U and 238 U) and trace elements (Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, and Tl) in these media were low and most were below regional upper level background concentrations (mean plus three sigma). The very few constituents that were above regional background concentrations were far below screening levels (set from State and Federal standards) for the protection of the human food chain and the terrestrial environment

Determination of 238U in marine organisms by inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Ishii, Toshiaki; Nakahara, Motokazu; Matsuba, Mitsue; Ishikawa, Masafumi

1991-01-01

Determination of 238 U in fifty-five species of marine organisms was carried out by inductively coupled plasma mass spectrometry which showed some advantages such as high sensitivity, wide dynamic range and small interferences from matrices for the analysis of high mass elements. The concentrations of 238 U in soft tissues of marine animals ranged from 0.076 to 5000 ng/g wet wt. Especially, the branchial heart of cephalopod molluscs showed the specific accumulation of 238 U. The concentration factor of the branchial heart of Octopus vulgaris, which indicated the highest value, was calculated to be about 10 3 by comparing it with the concentration of 238 U (3.2±0.2 ng/ml) in coastal seawaters of Japan. The concentrations of 238 U in hard tissues of marine invertebrates were similar to those in soft tissues. In contrast, hard tissues like bone, scale, fin, etc. of fishes showed much higher concentrations of 238 U than soft tissues like muscle and liver. The concentrations of 238 U of twenty species of algae ranged from 10 to 3700 ng/g dry wt. (author)

Steam in RR Telescopii and Henize 2-38

Energy Technology Data Exchange (ETDEWEB)

Allen, D A [Anglo-Australian Observatory, Epping (Australia); Beattie, D H; Lee, T J; Stewart, J M; Williams, P M

1978-03-01

Low-resolution scans in the 1.9-2.6..mu..m atmospheric window reveal steam (H/sub 2/O) and CO adsorption bands in the spectra of the symbiotic stars RR Tel and He 2-38. The steam absorption in RR Tel is particularly intense while the CO is weak, implying the presence in the system of a Mira variable seen near minimum light. In He 2-38 the steam band is weaker while the CO is stronger, as expected for a Mira seen near maximum.

49 CFR 238.231 - Brake system.

Science.gov (United States)

2010-10-01

...) Equipped with brake indicators as defined in § 238.5, designed so that the pressure sensor is placed in a... alcohol or other chemicals into the air brake system of passenger equipment is prohibited. (f) The...

Association between the SLC6A3 A1343G polymorphism and schizophrenia Associação entre o polimorfismo A1343G do SLC6A3 e esquizofrenia

Directory of Open Access Journals (Sweden)

Quirino Cordeiro

2010-10-01

Full Text Available Epidemiological studies have demonstrated that the genetic component is an important risk factor for the development of schizophrenia. The genes that codify the different compounds of the dopaminergic system have created interest for molecular investigations in patients with schizophrenia because the antipsychotic drugs, especially those of first generation, act on this cerebral system. Thus the aim of the present study was to investigate the possible association between a new single nucleotide polymorphism (rs6347 located in exon 9 of the protein transporter (SLC6A3 and schizophrenia. The distribution of the alleles and genotypes of the studied polymorphism was investigated in a sample of 235 patients and 834 controls matched by gender and age. There were statistical differences in the allelic (χ2=5.97, 1d.f. , p=0.01, OR=1.33-1.05Estudos epidemiológicos têm demonstrado que o componente genético é um importante fator de risco para a esquizofrenia. Os genes que codificam os diferentes componentes do sistema dopaminérgico passaram a despertar interesse para estudos moleculares em pacientes com esquizofrenia, pois os antipsicóticos, em especial os de primeira geração, exercem sua ação nesse sistema. Assim, o objetivo do presente estudo foi investigar a associação entre um novo polimorfismo de nucleotídeo único (rs6347 localizado no exon 9 do gene do transportador de dopamina (SLC6A3 e esquizofrenia. Um total de 235 pacientes e 834 controles pareados para sexo e idade foi selecionado para a investigação da distribuição dos alelos e genótipos do polimorfismo investigado entre os grupos de pacientes e controles. Houve diferenças estatisticamente significantes nas distribuições alélicas (χ2=5,97, 1d.f. , p=0,01, OR=1,33-1,05polimorfismo SLC6A3 A1343G mostrou associação com esquizofrenia na amostra estudada.

Association between the DRD2-141C Insertion/Deletion polymorphism and schizophrenia Associação entre o polimorfismo -141C Ins/Del do gene do DRD2 e esquizofrenia

Directory of Open Access Journals (Sweden)

Quirino Cordeiro

2009-06-01

Full Text Available Epidemiological studies have demonstrated that the genetic component is an important risk factor for the development of schizophrenia. The genes that codify the different compounds of the dopaminergic system have created interest for molecular investigations in patients with schizophrenia because the antipsychotic drugs, especially those of first generation, act on this cerebral system. Thus the aim of the present study was to investigate the possible association between the -141 Ins/Del (rs1799732 polymorphism of the dopamine receptor type 2 (DRD2 and schizophrenia. The distribution of the alleles and genotypes of the studied polymorphism was investigated in a sample of 229 patients and 733 controls. There were statistical differences in the allelic (χ2=9.78; p=0.001 and genotypic genotypic (χ2=12.74; p=0.001 distributions between patients and controls. Thus the -141C Ins/Del polymorphism of the DRD2 gene (allele Ins was associated to the SCZ phenotype in the investigated sample.Estudos epidemiológicos têm demonstrado que o componente genético é um importante fator de risco para o desenvolvimento de esquizofrenia. Os genes que codificam os diferentes componentes do sistema dopaminérgico passaram a despertar interesse para os estudos moleculares em pacientes com esquizofrenia, devido ao fato dos antipsicóticos, em especial os de primeira geração, exercerem sua ação nesse sistema. Assim, o objetivo do presente estudo foi investigar a possível associação entre polimorfismo -141C Ins/Del (rs1799732 do gene do receptor dopaminérgico tipo 2 (DRD2 e esquizofrenia. Um total de 229 pacientes e 733 controles pareados para sexo e idade foi selecionado com o objetivo de investigar a distribuição dos alelos e genótipos do polimorfismo investigado entre os grupos de pacientes e controles. Houve diferença estatisticamente significante nas distribuições alélica (χ2=9,78; p=0,001 e genotípica (χ2=12,74; p=0,001 entre pacientes e

Análisis de PCR-RFLP del gen de leptina y su asociación con características de la leche en ganado nativo (Bos indicus de Irán

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Mojtaba Rezaei

2015-01-01

Full Text Available Se utilizó una muestra ganadera experimental para la caracterización de los genes y las frecuencias genotípicas y evaluar la asociación entre los polimorfismos de longitud del fragmento de restricción BsaAI en el gen de leptina y las características lácteas. Se recolectaron muestras de sangre de 390 vacas proporcionadas por el censo ganadero de la provincia de Guilán en Irán. La extracción de ADN genómico se basó en el método modificado de precipitación salina. El fragmento de 522 bp que comprende la región parcial del exón 3 e intrón 2 del locus del gen de leptina se amplificó mediante PCR-RFLP e iniciadores específicos. La digestión del fragmento amplificado con la enzima de restricción BsaAI reveló dos alelos de A y B con frecuencias de 0.447 y 0.553, y tres genotipos de AA, AB, BB con frecuencias de 0.185, 0.526 y 0.289 en la población estudiada, respectivamente. El resultado del contenido de polimorfismo fue 0.372 y para heterocigosis 0.526. Los resultados demostraron que la población estudiada estaba en equilibrio Hardy-Weinberg. El análisis estadístico indicó que el polimorfismo LEP- BsaAI tiene un efecto significativo en la producción de leche, porcentaje de grasa y proteína de la leche ( P <0.01. Animales portadores del genotipo heterocigoto (AB produjeron 1.17 y 0.7 kg/d más leche que los animales homocigotos AA y BB, respectivamente. Los animales con el genotipo AA tuvieron mayor grasa (0.28 % y porcentaje de proteína (0.17 % que el genotipo AB. Tales resultados pueden utilizarse como criterios para facilitar la selección genética en los programas de cría animal.

Polymorphism of the grasshopper Rhammatocerus schistocercoides populations revealed by RAPD Polimorfismo em populações do gafanhoto Rhammatocerus schistocercoides revelado por marcadores RAPD

Directory of Open Access Journals (Sweden)

João Batista Tavares da Silva

2002-11-01

Full Text Available The objective of this work was to study the genetic variability of the grasshopper Rhammatocerus schistocercoides (Orthoptera: Acrididae using RAPD analysis among individuals from three populations, one from Colombia and two from Brazil (Goiás and Mato Grosso States. Ninety scorable binary markers were obtained by fingerprinting with 11 oligonucleotide primers. Most of the polymorphism was attributed to 42 markers with variable frequency among the different populations. Although the existence of significant difference among populations (PO objetivo deste trabalho foi estudar a variabilidade genética do gafanhoto Rhammatocerus schistocercoides (Orthoptera: Acrididae por meio da análise de RAPD entre indivíduos de três populações, uma da Colômbia e duas do Brasil (Goiás e Mato Grosso. Noventa marcadores binários foram selecionados através de análise de polimorfismo com o uso de 11 oligonucleotídeos. A maior parte do polimorfismo observado foi atribuída a 42 marcadores com freqüência variável entre as diferentes populações. Apesar da existência de diferença significativa interpopulacional (P<0,0001, grande proporção da variabilidade genética foi detectada dentro das populações (87,7% da variação total. As distâncias entre as populações colombianas e brasileiras foram 0,12 (P<0,0001 e 0,18 (P<0,0001 para Goiás e Mato Grosso, respectivamente. A distância obtida entre Goiás e Mato Grosso foi 0,06 (P<0,0001. Estes dados indicam que as diferenças fenotípicas entre populações estão associadas principalmente às distâncias geográficas entre as populações do Brasil e a da Colômbia.

Effect of time dependence of neutron flux on the plutonium 238 production

International Nuclear Information System (INIS)

Rudik, A.P.

1975-01-01

An analytical treatment is given of the dependence of a plutonium-238 yield when irradiating neptunium-237 on the time variation of the neutron flux. This dependence is governed by the two physical factors: the competition between the beta decay and the neptunium-238 depletion, and the differences in the depletion rate of neptunium-237, neptunium-238 and plutonium-238 with thermal and resonance neutrons. The role of the neptunium-238 nonprompt decay has been studied and the order of the effect determined, and it has been established that it is advantageous to irradiate neptunium-237 in the lowest central neutron flux possible for thermal and resonance neutron reactors. A perturbation theory has been developed to determine the role of the time variation of the thermal neutron flux and it has been established that, the integral neutron flux being the same, it is advantageous to irradiate the material in a drooping rather than a constant flux of neutrons. The simplest example of great time variations of a neutron flux has been considered and it has been established that in this particular case the conclusions made in the framework of the perturbation theory find a qualitative support. Convenient formulas are given for determining the number of neutrons used to produce plutonium-238

Polimorfismos genéticos asociados a pre-eclampsia

OpenAIRE

Baquero Mejía, Ingrid Carolina

2013-01-01

RESUMEN: La pre-eclampsia es un trastorno multisistémico del embarazo y del puerperio, que complica aproximadamente del 6 al 8% de todos los embarazos en los países desarrollados. Es considerada un problema de salud pública debido a su alta prevalencia. Es una de las causas más frecuentes de mortalidad materno-fetal en países en desarrollo, igualmente es causa de preocupación en los países desarrollados por su gran relación causal con el retraso de crecimiento intrauterino y partos prematuro...

Determination of sup 238 U in marine organisms by inductively coupled plasma mass spectrometry. Yudo ketsugo plasma shitsuryo bunsekiho ni yoru kaiyo seibutsuchu no sup 238 U no teiryo

Energy Technology Data Exchange (ETDEWEB)

Ishii, T.; Nakahara, M; Matsuda, M.; Ishikawa, M. (National Institute of Radiological Sciences, Ibaraki (Japan))

1991-05-25

Since the {sup 238} U concentration in seawater is about 3ng/ml at the element level and the activity concentration is 40 {mu} Bq/ml which are considerably higher that those of other {alpha} radioactive materials, it is necessary to study the concentration levels of many marine organisms. After confirming that the inductively coupled plasma mass spectrometry as a new high sensitive analysis for multi-elements is effective to analyze heavy elements such as rare earth elements or uranium, etc., this method was applied to determine {sup 238} U in 55 species of marine organism. The {sup 238} U concentration in soft tissues of marine animal ranged from 0.076 to 5000ng/g wet weight and large difference of concentration was observed depending on the kind of animal and the tissue. Especially, the branchial heart of cephalopod molluscs showed the specific accumulation of {sup 238} U. The concentration factor of branchial heart of Octopus vulgaris which showed the highest value was calculated to be about 10 {sup 3} by comparing it with the concentration of {sup 238} U in Japanese coastal waterseas. The concentration of {sup 238} U in 20 species of algae ranged from 10 to 3700ng/g dry weight. 11 refs., 2 figs., 9 tabs.

Measurement of {sup 238}Np fission cross-section by neutrons near thermal point (preliminary results)

Energy Technology Data Exchange (ETDEWEB)

Abramo; vich, S.N.; Andreev, M.F.; Bol`shakov, Y.M. [Institute of Experimental Physics, Arzamas (Russian Federation)] [and others

1995-10-01

Measurements have been carried out of {sup 238}Np fission cross-section by thermal neutrons. The isotope {sup 238}Np was built up through the reaction {sup 238}U(p,n) on an electrostatic accelerator. Extraction and cleaning of the sample were done by ion-exchange chromatography. Fast neutrons were generated on the electrostatic accelerator through the reaction {sup 9}Be(d,n); a polyethylene block was used to slow down neutrons. Registration of fission fragments was performed with dielectric track detectors. Suggesting that the behavior of {sup 238}Np and {sup 238}U. Westscott`s factors are indentical the fission cross-section of {sup 238}Np was obtained: {sigma}{sub fo}=2110 {plus_minus} 75 barn.

The Characterization of Biotic and Abiotic Media Upgradient and Downgradient of the Los Alamos Canyon Weir

Energy Technology Data Exchange (ETDEWEB)

P.R. Fresquez

2006-01-15

As per the Mitigation Action Plan for the Special Environmental Analysis of the actions taken in response to the Cerro Grande Fire, sediments, vegetation, and small mammals were collected directly up- and downgradient of the Los Alamos Canyon weir, a low-head sediment control structure located on the northeastern boundary of Los Alamos National Laboratory, to determine contaminant impacts, if any. All radionuclides ({sup 3}H, {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu, {sup 90}Sr, {sup 241}Am, {sup 234}U, {sup 235}U and {sup 238}U) and trace elements (Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, and Tl) in these media were low and most were below regional upper level background concentrations (mean plus three sigma). The very few constituents that were above regional background concentrations were far below screening levels (set from State and Federal standards) for the protection of the human food chain and the terrestrial environment.

Optimization of the binary breeder reactor. VIII annular core fueled with 233U - 238U and Pu-238U

International Nuclear Information System (INIS)

Nascimento, J.A. do; Ishiguro, Y.

1988-04-01

First cycle burnup characteristics of a 1200 MWe binary breeder reactor with annular core fueled with metallic 233 U- 238 U-Zr, Pu- 238 U-Zr and Th in the blankets have been analysed. The Doppler effect is small as expected in a metal fueled fast reactor. The sodium void reactivity is, in general, smaller than in metal fueled homogeneous fast reactors of 1 m core height. The estimates of the required and available control rod worths show a large shutdown margin throughout the operational cycle. There are flexibilities in the blanket fueling and well balanced breeding in the two cycles, uranium and thorium, with doubling times of about 20 years are possible. (author) [pt

National low-level waste management program radionuclide report series, Volume 15: Uranium-238

International Nuclear Information System (INIS)

Adams, J.P.

1995-09-01

This report, Volume 15 of the National Low-Level Waste Management Program Radionuclide Report Series, discusses the radiological and chemical characteristics of uranium-238 ( 238 U). The purpose of the National Low-Level Waste Management Program Radionuclide Report Series is to provide information to state representatives and developers of low-level radioactive waste disposal facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the waste disposal facility environment. This report also includes discussions about waste types and forms in which 238 U can be found, and 238 U behavior in the environment and in the human body

Brain-derived neurotrophic factor gene val66met polymorphism and executive functioning in patients with bipolar disorder Polimorfismo do gene do fator neurotrófico derivado do cérebro val66met e função executiva em pacientes com transtorno bipolar

Directory of Open Access Journals (Sweden)

Juliana Fernandes Tramontina

2009-06-01

Full Text Available OBJECTIVE: In the present study, we investigate the association between the val66met polymorphism of the brain-derived neurotrophic factor (BNDF and the performance on the Wisconsin Card Sorting Test in a sample of Caucasian Brazilian patients with bipolar disorder. METHOD: Sixty-four patients with bipolar disorder were assessed and their performance on the Wisconsin Card Sorting Test was compared with the allele frequency and genotype of the val66met polymorphism of the brain-derived neurotrophic factor. RESULTS: The percentage of non-perseverative errors was significantly higher among patients with the val/val genotype. There was no association between (BNDF genotype frequency and other Wisconsin Card Sorting Test domains. CONCLUSION: Our results did not replicate previous descriptions of an association between a worse cognitive performance and the presence of the met allele of the val66met brain-derived neurotrophic factor gene polymorphism.OBJETIVO: O presente estudo tem por objetivo investigar a associação entre o polimorfismo val66met do gene do fator neurotrófico derivado do cérebro (BDNF e o desempenho cognitivo no Teste Wisconsin de Classificação de Cartas em uma amostra de pacientes bipolares brasileiros caucasianos. MÉTODO: Sessenta e quatro pacientes com transtorno bipolar foram avaliados em relação a sua cognição por meio do Teste Wisconsin de Classificação de Cartas que foi comparada com a freqüência alélica e genotípica do polimorfismo val66met do gene do fator neurotrófico derivado do cérebro. RESULTADOS: O percentual de erros não-perseverativos foi significativamente maior nos indivíduos com genótipo val/val. Não foi encontrada diferença significativa entre a freqüência genotípica do polimorfismo do BDNF e os outros domínios do Teste Wisconsin de Classificação de Cartas. CONCLUSÃO: O estudo do polimorfismo val66met em relação ao desempenho executivo em pacientes bipolares caucasianos de uma

Some physico-chemical and radiation properties of plutonium-238 metal prepared by electrochemical amalgamation

Energy Technology Data Exchange (ETDEWEB)

Peretrukhin, V.F. [A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky Prospect, Moscow 119991 (Russian Federation)], E-mail: vperet@ipc.rssi.ru; Rovny, S.I. [Production Association ' Mayak' , 31 Prospect Lenin, Ozersk, Chelyabinsk Region 456784 (Russian Federation); Maslennikov, A.G. [A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky Prospect, Moscow 119991 (Russian Federation); Ershov, V.V.; Chinenov, P.P.; Kapitonov, V.I.; Kuvaev, V.L. [Production Association ' Mayak' , 31 Prospect Lenin, Ozersk, Chelyabinsk Region 456784 (Russian Federation)

2007-10-11

Pu-238 metal was prepared by electrolytic amalgamation from Pu(III) acetate aqueous solution and by followed by the thermal decomposition of the Pu amalgam. The density, specific heat power, {gamma}-spectra, neutron flux, and corrosion kinetics in dry air at ambient temperature of the prepared {sup 238}Pu metal were measured. The neutron flux and {gamma}-spectra from {sup 238}Pu metal have been attributed to spontaneous and induced fission and to ({alpha},{alpha}'{gamma}), ({alpha},p{gamma}), and ({alpha},n{gamma}) nuclear reactions on light nuclei. The electrochemically prepared {sup 238}Pu metal was shown to generate fewer neutrons, produce less gamma radiation, and contains lower {sup 10}B, {sup 19}F, and {sup 28}Si impurities in comparison with biomedical {sup 238}PuO{sub 2}. The increase of neutron flux from the sample due to the reaction {sup 18}O({alpha},n{gamma}) {sup 21}Ne was shown to be proportional to the increase of the mass of the {sup 238}Pu metal with time due to corrosion in dry air. {sup 238}Pu metal corrosion rate maximum and average values (1.1 x 10{sup -2} and 4.7 x 10{sup -3} mg cm{sup -2} h{sup -1}, respectively) obtained in dry air were an order of magnitude higher than the rates published for {sup 239}Pu under similar experiment conditions. The difference between the {sup 239}Pu and {sup 238}Pu metal corrosion rate and mechanism is proposed to be due to the greater radiation effects and temperature on the {sup 238}Pu surface.

238Pu concentrations in the marine environment at San Clemente Island

International Nuclear Information System (INIS)

Noshkin, V.E.; Brunk, J.L.; Jokela, T.A.; Wong, K.M.

1981-01-01

The concentration of plutonium and other radionuclides measured in samples of surface sediments, seawater and brown algae collected offshore from North Light Harbor Pier at San Clemente Island, CA, are presented. From 1967 to 1978, different forms of nuclear fuels used in operational or proposed SNAP (Systems for Nuclear Auxillary Power) devices were tested at this site to evaluate the effects of seawater on the heat sources. The principle radionuclide in the heat sources tested was 238 Pu. During these tests, small amounts of 238 Pu dissolved and migrated from the test chambers to the local marine environment. Currents dispersed this released 238 Pu so that at present a small increase in concentration above that of fallout background is evident in the surface 3.0-cm layer of near shore sediment that extends over a 3.0-km 2 area surrounding the pier. The 238 Pu associated with this sediment is slowly redissolving and can be taken up by marine algae. Except for a 0.025-km 2 region around the pier, the total plutonium ( 238 Pu + 239+240 Pu) in the surface 3.0-cm layer of sediment is within the range of total fallout plutonium reported in Atlantic and Pacific surface deposits from water depths less than 100 m. (author)

A proposed new mission for producing 238Pu at the Hanford site

International Nuclear Information System (INIS)

Cash, R.J.

1989-01-01

A new mission for producing 238 Pu has been proposed at the Hanford site. If approved, the program would produce 238 Pu for National Aeronautics and Space Administration (NASA) space missions and possibly other speciality isotopes for medical and industrial applications. The 238 Pu isotope is an excellent heat source and is currently used in generating electricity for deep-space applications. To produce 238 Pu, special neptunium target assemblies would be irradiated for ∼2 yr in the Fast Flux Test Facility (FFTF) operated by Westinghouse Handford Company. After ∼1 yr of cooling, the neptunium pins would be reprocessed in special hot cells in the Fuel and Materials Examination Facility (FMEF) at the Hanford site to recover the 238 Pu and convert it into the oxide form. The oxide could then be encapsulated in the FMEF using special materials and procedures to meet rigid NASA requirements. The plutonium oxide capsules would later become part of the radioisotope thermoelectric generators used by NASA to power equipment launched into space. To meet projected NASA mission requirements, the program would provide the capability to recover up to 30 kg/yr of 238 Pu from 237 Np targets by late 1993. The conceptual design for the program was completed by Westinghouse Hanford in September 1989 for validation and approval by the U.S. Department of Energy

48 CFR 552.238-74 - Industrial Funding Fee and Sales Reporting.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Industrial Funding Fee and Sales Reporting. 552.238-74 Section 552.238-74 Federal Acquisition Regulations System GENERAL SERVICES... shall include the Industrial Funding Fee (IFF). The Contractor shall maintain a consistent accounting...

Neutron scattering cross sections of uranium-238

International Nuclear Information System (INIS)

Beghian, L.E.; Kegel, G.H.R.; Marcella, T.V.; Barnes, B.K.; Couchell, G.P.; Egan, J.J.; Mittler, A.; Pullen, D.J.; Schier, W.A.

1979-01-01

The University of Lowell high-resolution time-of-flight spectrometer was used to measure angular distributions and 90-deg excitation functions for neutrons scattered from 238 U in the energy range from 0.9 to 3.1 MeV. This study was limited to the elastic and the first two inelastic groups, corresponding to states of 238 U at 45 keV (2 + ) and 148 keV (4 + ). Angular distributions were measured at primary neutron energies of 1.1, 1.9, 2.5, and 3.1 MeV for the same three neutron groups. Whereas the elastic data are in fair agreement with the evaluation in the ENDF/B-IV file, there is substantial disagreement between the inelastic measurements and the evaluated cross sections. 12 figures

33 CFR 238.9 - Local cooperation.

Science.gov (United States)

2010-07-01

... DEFENSE WATER RESOURCES POLICIES AND AUTHORITIES: FLOOD DAMAGE REDUCTION MEASURES IN URBAN AREAS § 238.9... with applicable regulations for structural and non-structural flood damage reduction measures. (b..., enforce, and adhere to a sound, comprehensive plan for flood plain management for overflow areas of...

Associação dos polimorfismos dos genes da óxido nítrico sintase e metaloproteinases da matriz extracelular com a pré-eclâmpsia

OpenAIRE

Daniela Pinheiro Leonardo

2015-01-01

Resumo: A pré-eclâmpsia é uma das principais causas de morbidade e mortalidade materna e neonatal no mundo, porém a sua fisiopatologia ainda não foi totalmente elucidada, sendo considerada uma síndrome com acometimento multisistêmico e etiologia multifatorial. O fator genético tem sido bastante estudado, com associação dos polimorfismos de nucleotídeo único em genes que codificam óxido nítrico sintase e metaloproteases de matriz com pré-eclâmpsia, porém os resultados foram inconclusivos em di...

Association between IGF-IR gene polymorphisms and productive and reproductive traits in Holstein cows Associação entre polimorfismos do gene IGF-IR e características produtivas e reprodutivas em fêmeas bovinas da raça Holandesa

Directory of Open Access Journals (Sweden)

W. Schoenau

2005-12-01

Full Text Available The association between single-strand conformation polymorphism (SSCP in the gene of insulin-like growth factor-I receptor (IGF-IR and age at first calving (AFC, calving interval (CI, lactation length (LL, and milk yield (MY was studied using 106 graded Holstein females. The polimerase chain reaction (PCR with specific initiating oligonucleotides, resulted an amplified fragment of 335pb. The population genotypes frequencies were 82.1% and 17.9%, for AA and AB genotypes, respectively. The frequency of A allele was 0.91 and 0.09 of B allele. No association between the identified polymorphism and AFC, CI, and MY was observed. The LL was positively associated (PEstudou-se a associação entre polimorfismos de conformação de fita simples (SSCP no gene do receptor do fator-I de crescimento semelhante à insulina (IGF-IR e idade ao primeiro parto (IPP, intervalo entre partos (IEP, duração da lactação (DL e produção de leite (PL, em 106 fêmeas puras por cruza da raça Holandesa. A reação em cadeia da polimerase (PCR com oligonucleotídeos iniciadores específicos gerou um fragmento de 335pb. A freqüência genotípica da população para o polimorfismo foi 82,1% de indivíduos homozigotos para o alelo A e 17,9% de heterozigotos (AB. A freqüência do alelo A foi 0,91 e a do alelo B, 0,09. Não foi encontrada associação entre o polimorfismo estudado e as características IPP, IEP e PL. A característica DL foi positivamente associada (P<0,05 à ausência do alelo B. A lactação dos animais portadores do genótipo AA foi mais longa.

Hematological responses after inhaling 238PuO2: An extrapolation from beagle dogs to humans

International Nuclear Information System (INIS)

Scott, B.R.; Muggenburg, B.A.; Welsh, C.A.; Angerstein, D.A.

1994-01-01

The alpha emitter plutonium-238 ( 238 Pu), which is produced in uranium-fueled, light-water reactors, is used as a thermoelectric power source for space applications. Inhalation of a mixed oxide form of Pu is the most likely mode of exposure of workers and the general public. Occupational exposures to 238 PuO 2 have occurred in association with the fabrication of radioisotope thermoelectric generators. Organs and tissue at risk for deterministic and stochastic effects of 238 Pu-alpha irradiation include the lung, liver, skeleton, and lymphatic tissue. Little has been reported about the effects of inhaled 238 PuO 2 on peripheral blood cell counts in humans. The purpose of this study was to investigate hematological responses after a single inhalation exposure of Beagle dogs to alpha-emitting 238 PuO 2 particles and to extrapolate results to humans

238U (n,f) measurements below 30 keV

International Nuclear Information System (INIS)

Slovacek, R.E.; Cramer, D.S.; Bean, E.B.; Hockenbury, R.W.; Valentine, J.R.; Block, R.C.

1975-01-01

The 238 U (n,f) cross section has been measured from 3 eV to about 30 keV with the lead slowing down spectrometer at the RPI Linac. Four fission ionization chambers containing a total of about 0.8 gm of 238 U (4.1 ppm 235 U) were used for the measurements. The fission widths of the 6.67, 20.9, and the 36.8 eV resonances were measured as (10 +- 1), (58 +- 9), and (12 +- 2) nanoelectron-volts respectively. The fission cross section integrated over the two subthreshold groups at 720 and 1210 eV and the average fission cross section from 10 to 30 keV are in agreement with a previous time of flight measurement. The fission width at 6.67 eV is 20 times smaller than an upper limit set by the only reported measurement in this energy region; the fission widths obtained in the present investigation are consistent with the (30 +- 50) nanoelectronvolt average width previously obtained for the resonances between 37 and 327 eV in a time of flight measurement using a nuclear device. From the measured fission widths, the 238 U thermal fission cross section was determined to be 2.7 +- 0.3 μ barns. The resonance fission integral was also obtained from the data as 1.33 +- 0.15 mbarns for 238 U. (4 figures, 4 tables) (U.S.)

Cross-section activation measurement for U-238 through protons and deuterons in energy interval 10-14 MeV

Energy Technology Data Exchange (ETDEWEB)

Guzhovskii, B.Y.; Abramovich, S.N.; Zvenigorodskii, A.G. [Russia Federal Nuclear Centre, Arzamas (Russian Federation)] [and others

1995-10-01

There were presented results of cross-section measurements for nuclear reactions {sup 238}U(p,n){sup 238}Np, {sup 238}U(d,2n){sup 238}Np, {sup 238}U(d,t){sup 237}U, {sup 238}U(d,p){sup 239}U, and {sup 238}U(d,n){sup 239}Np. Interval of projectile energy was 10-14 MeV. For measurements of cross-sections it was used the activatio methods. The registration of {beta}- and {gamma}-activity was made with using of plastic scintillation detector and Ge(Li)-detector.

49 CFR 238.409 - Forward end structures of power car cabs.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Forward end structures of power car cabs. 238.409... II Passenger Equipment § 238.409 Forward end structures of power car cabs. This section contains requirements for the forward end structure of the cab of a power car. (A conceptual implementation of this end...

49 CFR 238.411 - Rear end structures of power car cabs.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Rear end structures of power car cabs. 238.411... II Passenger Equipment § 238.411 Rear end structures of power car cabs. The rear end structure of the cab of a power car shall be designed to include the following elements, or their structural equivalent...

Characterization and testing of a 238Pu loaded ceramic waste form

International Nuclear Information System (INIS)

Johnson, S. G.

1998-01-01

This paper will describe the preparation and progress of the effort at Argonne National Laboratory-West to produce ceramic waste forms loaded with 238 Pu. The purpose of this study is to determine the extent of damage, if any, that alpha decay events will play over time to the ceramic waste form under development at Argonne. The ceramic waste form is glass-bonded sodalite. The sodalite is utilized to encapsulate the fission products and transuranics which are present in a chloride salt matrix which results from a spent fuel conditioning process. 238 Pu possesses approximately 250 times the specific activity of 239 Pu and thus allows for a much shorter time frame to address the issue. In preparation for production of 238 Pu loaded waste forms 239 Pu loaded samples were produced. Data is presented for samples produced with typical reactor grade plutonium. X-ray diffraction, scanning electron micrographs and durability test results will be presented. The ramifications for the production of the 238 Pu loaded samples will be discussed

Light nuclides observed in the fission and fragmentation of 238U

International Nuclear Information System (INIS)

Ricciardi, M.V.; Schmidt, K.H.; Benlliure, J.

2001-05-01

Light nuclides produced in collisions of 1 A.GeV 238 U with protons and titanium have been fully identified with a high-resolution forward magnetic spectrometer, the fragment separator (FRS), at GSI, and for each nuclide an extremely precise determination of the velocity has been performed. The so-obtained information on the velocity shows that the very asymmetric fission of uranium, in the 238 U + p reaction, produces neutron-rich isotopes of elements down to around charge 10. New important features of the fragmentation of 238 U, concerning the velocity and the N/Z-ratio of these light fragments, and a peculiar even-odd structure in N=Z nuclei, have also been observed. (orig.)

Nitrate Anion Exchange in Pu-238 Aqueous Scrap Recovery Operations

International Nuclear Information System (INIS)

Pansoy-Hjelvik, M.E.; Silver, G.L.; Reimus, M.A.H.; Ramsey, K.B.

1999-01-01

Strong base, nitrate anion exchange (IX) is crucial to the purification of 238 Pu solution feedstocks with gross levels of impurities. This paper discusses the work involved in bench scale experiments to optimize the nitrate anion exchange process. In particular, results are presented of experiments conducted to (a) demonstrate that high levels of impurities can be separated from 238 Pu solutions via nitrate anion exchange and, (b) work out chemical pretreatment methodology to adjust and maintain 238 Pu in the IV oxidation state to optimize the Pu(IV)-hexanitrato anionic complex sorption to Reillex-HPQ resin. Additional experiments performed to determine the best chemical treatment methodology to enhance recovery of sorbed Pu from the resin, and VIS-NIR absorption studies to determine the steady state equilibrium of Pu(IV), Pu(III), and Pu(VI) in nitric acid are discussed

238U photonuclear studies with 5-10 MeV photons

International Nuclear Information System (INIS)

Hawkes, N.P.

1986-02-01

The 238 U photofission and photoneutron cross sections, and the mean number -ν of prompt neutrons per fission, have been measured between 5 and 10 MeV. The experiment was carried out using bremsstrahlung from the electron linear accelerator HELIOS at Harwell. Neutrons from (γ,f) and (γ,n) reactions on 238 U were detected, and neutron multiplicity distributions recorded. Photoneutron events were separated from photofission events by means of their different multiplicities. (author)

Limitations on the precision of 238U/235U measurements and implications for environmental monitoring

International Nuclear Information System (INIS)

Russ III, G.P.

1997-01-01

The ability to determine the isotopic composition of uranium in environmental samples is an important component of the International Atomic Energy Agency's (IAEA) safeguards program, and variations in the isotopic ratio 238 U/ 235 U provide the most direct evidence of isotopic enrichment activities. The interpretation of observed variations in 238 U/ 235 U depends on the ability to distinguish enrichment from instrumental biases and any variations occurring in the environment but not related to enrichment activities. Instrumental biases that have historically limited the accuracy of 238 U/ 235 U determinations can be eliminated by the use of the 233 U/ 236 U double-spike technique. With this technique, it is possible to determine the 238 U/ 235 U in samples to an accuracy equal to the precision of the measurement, ca. 0.1% for a few 10's of nanograms of uranium. Given an accurate determination of 238 U/ 235 U, positive identification of enrichment activities depends on the observed value being outside the range of 238 U/ 235 U's expected as a result of natural or environmental variations. Analyses of a suite of soil samples showed no variation beyond 0.2% in 238 U/ 235 U

Evaluation of neutron-induced reactions in 48Ti and 238U

International Nuclear Information System (INIS)

Carlson, B.V.; Fiorentino, J.; Frederico, T.; Isidro Filho, M.P.; Mastroleo, R.C.; Rego, R.A.

1984-05-01

Preliminary results of the evaluation of neutron-induced reactions in 48 Ti and 238 U are presented. Calculated cross sections for the reactions (n,γ), (n,n'), (n, 2n) and (n,p) as well as for (n,f) in 238 U are given. Comparisons with available experimental data are made and possible changes in the parameters are discussed. (Author) [pt

²³⁸PuO₂ Fuel and Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Mayo, Douglas R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rawool-Sullivan, Mohini [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Garner, Scott Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wenz, Tracy R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-06-01

²³⁸Pu is an ideal material for use as a heat source with its half-life of 87.7 years and copious particle emissions. ²³⁸Pu radioisotope thermoelectric generators (RTGs) have found use for pacemakers, Apollo Space missions, Mars rovers, and Voyager spacecraft. In evaluating the dose to personnel and components near a ²³⁸Pu-based RTG, a number of additional nuclides and their daughter products must be considered to get an accurate estimate for γ-dose, and the amount of ¹⁷O and ¹⁸O for the neutron-dose must be considered. This paper looks at the contributing nuclides and their daughter products that add the most to the dose rates.

Polimorfismo do gene dos receptores de progesterona e o aborto espontâneo de repetição Progesterone receptor gene polymorphism and recurrent spontaneous abortion

Directory of Open Access Journals (Sweden)

Évelyn Traina

2010-05-01

Full Text Available OBJETIVO: investigar se polimorfismos dos genes que codificam o receptor de progesterona (PROGINS estão relacionados à ocorrência de aborto espontâneo de repetição (AER. MÉTODOS: em estudo caso-controle, foram selecionados 85 pacientes com antecedente de pelo menos três abortos precoces sem etiologia definida (Grupo Caso e 157 mulheres com história de pelo menos duas gestações de termo sem intercorrências e sem passado de abortamento (Grupo Controle. Realizada coleta de 10 mL de sangue por punção venosa periférica e extração de DNA pela técnica DTAB/CTAB. As genotipagens foram feitas por reação em cadeia de polimerase (PCR, nas condições de ciclagem específica para o polimorfismo em estudo, seguida de amplificação em gel de agarose a 2%. A visualização das bandas foi feita sob luz ultravioleta e os géis foram fotografados. As diferenças genotípicas e alélicas entre os dois grupos para o polimorfismo PROGINS foram calculadas pelo teste de χ2, adotando-se como nível de significância valores de pPURPOSE: to assess a possible association between polymorphism of the progesterone receptor gene (PROGINS and recurrent spontaneous abortion (RSA. METHODS: in this case-control study, 85 women with at least three previous spontaneous abortions without an identifiable cause (RSA Group and 157 women with at least two previous term pregnancies without pathologies and no previous miscarriage (Control Group were selected. An amount of 10 mL of peripheral blood was collected by venipuncture and genomic DNA was extracted by the DTAB/CTAB method, followed by the polymerase chain reaction (PCR under specific conditions for this polymorphism and by amplification by 2% agarose gel electrophoresis. The bands were visualized with an ultraviolet light transilluminator and the gels were photographed. Differences in the PROGINS genotype and allele frequencies between groups were analyzed by the χ2 test, with the level of significance set

Variantes del ADNmt en isleños del lago Titicaca: máxima frecuencia del haplotipo B1 y evidencia de efecto fundador

Directory of Open Access Journals (Sweden)

José Sandoval

2013-06-01

Full Text Available Los polimorfismos del ADN mitocondrial son herramientas en el estudio comparativo de poblaciones modernas y antiguas. Entre los más usados están los haplotipos mitocondriales basados en RFLP (polimorfismo de longitud de fragmentos de restricción y un sistema de inserción /deleción. El presente estudio establece la frecuencia de estos haplotipos y compara un total de 144 individuos representativos de las islas Taquile y Amantaní (lengua quechua y de las islas de Los Uros y Anapia (lengua aymara del lago Titicaca, Perú. Nuestros resultados revelan la predominancia del haplotipo B1: 100% en Taquile (n=57; 88,6% en Amantaní (n=35; 75% en Los Uros (n=28 y 87,5% en Anapia (n=24, siendo las frecuencias más altas registradas en el mundo. Otros haplotipos se observan en menor proporción: 17,9% de A2 y 7,1% de D1 en Los Uros; 11,4% de la variante C1 en Amantaní; 4,2% de cada haplotipo C1, C2 y D1 en Anapia. La alta frecuencia de B1 indica que las poblaciones de Taquile, Amantaní y Anapia provienen de un grupo fundador reducido. Aunque hay afinidad entre las poblaciones aymaras de Anapia y Los Uros; la proporción de algunos alelos en los últimos, sugiere la persistencia de un acervo genético uru en contraposición a la idea de su extinción.

HANFORD Pu-238 DRUM INTEGRITY ASSESSMENT

International Nuclear Information System (INIS)

CANNELL, G.R.

2004-01-01

Hanford is presently retrieving contact-handled, transuranic (CH-TRU) waste drums from the site's Low-Level Burial Grounds (LLBG) for processing and disposition. A subgroup of these drums (12 total), referred to as Pu-238 drums, has some unique characteristics that may impact the current drum handling and processing activities. These characteristics include content, shielding, thermal, pressurization and criticality issues. An effort to evaluate these characteristics, for the purpose of developing a specific plan for safe retrieval of the Pu-238 drums, is underway. In addition to the above evaluation, the following integrity assessment of the inner container material and/or confinement properties, with primary emphasis on the Source Capsule (primary confinement barrier) and Shipping Container has been performed. Assessment included review of the inner container materials and the potential impact the service history may have had on material and/or confinement properties. Several environmental degradation mechanisms were considered with the objective of answering the following question: Is it likely the container material and/or confinement properties have been significantly altered as a result of service history?

Polimorfismo isoenzimático en cuatro razas y un híbrido de Bactris gasipaes (Palmae

Directory of Open Access Journals (Sweden)

Sonia Rojas-Vargas

1999-12-01

Full Text Available Se estandarizó un sistema de electroforesis de isoenzimas con tejido de hojas que permitió la identificación del polimorfismo fenético entre cuatro razas y un híbrido de pejibaye Bactris gasipaes provenientes de Brasil, Perú, Bolivia, Panamá y Costa Rica. Las isoenzimas ensayadas fueron: PRX, EST, ACP, ME, DIA, MDH, G6PDH, PGI, SOD, PGM, ADH, GOT, de estas solamente las dos œltimas no mostraron actividad. El resto de isoenzimas mostraron polimorfismo fenético en diferentes grados, por esto se consideran marcadores polimórficos potenciales para estudios de variabilidad genética en pejibaye. Se encontró un locus único en el zimograma de la enzima PRX en las muestras de Utilis-Guápiles (CR, el cual podría usarse como un marcador discriminatorio para esta raza. Se establecieron relaciones de similitud isoenzimática entre las razas Utilis-Guápiles (CR y Tuira-Darién (Pa; Tembé-Chapare (Bo y Pará-Belem (Bra respectivamente, mientras que el híbrido Yurimaguas (Pe se ubicó aparte y ligeramente más cercano a Utilis y Tuira, por esto se considera que posiblemente desciende de padres aún no identificados.The study of genetic diversity in peach palm (Bactris gasipaes K. is important for the breeding work on this palm and to corroborate the hypotheses on its origins. For that purpose it is necessary to use alternative techniques to complement the morphological studies traditionally made. One of the techniques that responds to that need is isozyme electrophoresis. The isozymes are biochemical markers of importance in the study of genetic variability in plants of economic importance, because they are the primary products of genetic expression. This work is an electrophoretic analysis on gels of polyacrilamide to study phenetic relations using twelve isozymes on four races and an spontaneous hybrid of peach palm. The biological material used came from the germplasm bank from Los Diamantes Experimental Station, Guápiles-Costa Rica. Four

Niveles de homocisteína y polimorfismos de los genes de la MTHFR y la CBS en pacientes colombianos con trombosis venosa superficial y profunda

Directory of Open Access Journals (Sweden)

Claudia Ayala

2010-08-01

Conclusiones. No se encontraron diferencias estadísticamente significativas en los niveles de homocisteína entre el grupo de casos y de controles. Sin embargo, la variabilidad en las concentraciones plasmáticas fue mayor en los casos.

49 CFR 238.447 - Train operator's controls and power car cab layout.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Train operator's controls and power car cab layout. 238.447 Section 238.447 Transportation Other Regulations Relating to Transportation (Continued... layout. (a) Train operator controls in the power car cab shall be arranged so as to minimize the chance...

Statistical analysis of parameters of the uranium -238 resonances

International Nuclear Information System (INIS)

Nikolaev, M.N.; Abagyan, L.P.

1976-01-01

It has been shown that the distribution for 238 U p - levels can be in agreement with the theoretical one (Porter - Thomas distribution) only if the significant lack of p - levels in the experiments would be supposed. That means that density of 238 U levels with spin 1/2 is parity dependent, and therefore the whole number of p - resonances is 4.8 (instead of 3) times greater than the number of s - resonances in the same energy internal. With the assumption about spin dependence of strength function it is impossible to agree the experimental distribution with the theoretical one

Estimación de las frecuencias alélicas y genotípicas de los genes CAPN1 Y CAST asociados a la calidad de la carne en bovinos de la Cuenca del Papaloapan

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C.M. Desgarennes-Alcalá

2017-01-01

Full Text Available El ganado de doble propósito es aquel utiliz ado para producir carne y leche. G eneralmente es el producto del cruce de razas de origen Cebú x europeas y/o Criollo. Este grupo genético se ha adaptado a las condiciones climáticas de temperatura, humedad, baja calidad de pastos y clases de parásitos que prevalecen en las regiones tropicales. En este trabajo, se realizó un escrutinio molecular para observar la frecuencia de dos polimorfismos d el gen de la μ - calpaína (CAPN1 - 316, CAPN1 - 530 y uno del gen de la calpastatina ( CAST, asociados a la suavidad de la carne en ganado bovino de doble propósito de la Cuenca del Papaloapan. Las pruebas se basaron en Reacción en Cadena de la Polimerasa (PCR y Polimorfismos de la Longitud de Fragmentos de Restricción (RFLPs con las enzimas de restricción Btg I, Ava II y Rsa I para los alelos C - G, A - G y C - G, respectivamente (n=331. Para CAPN1 - 316 las frecuencias genotípicas obtenidas fueron de 0.03 (AA, 0.8 6 (GG y 0.11 (GA y las frecuencias alélicas fueron 0.86 (G y 0.14 (A. Para el marcador CAPN1 - 530 las frecuencias genotípicas fueron de 0.02 (CC, 0.85 (GG y 0.13 (GC, con una frecuencia alélica de 0.85 para G y 0.15 para C. Las frecuencias genotípica s para el marcador CAST fueron de 0.32 (CC, 0.28 (GG y 0.4 (GC, con una frecuencia alélica de 0.68 para el alelo G y 0.32 para el alelo C. La pobl a ción en estudio no se encontró en equilibrio Hardy Weinberg y los valores de χ 2 P con dos grados de liberta d fueron de 0.964, 0.985 y 0.9803 para CAPN1 - 316, CAPN1 - 530 y CAST, respectivamente. De acuerdo con el porcentaje de la genotipificación de los marcadores en los genes CAPN1 y CAST se concluye que la población analizada tiene bajos índices de marc a dores pa ra la suavidad o terneza de la carne, probablemente por las cruzas no dirigidas que se realizan habitualmente, de esta forma se propone, mejorar la calidad de la carne en base a programas de mejoramiento gen

Disposition of 238Pu(NO3)4 following inhalation by beagle dogs

International Nuclear Information System (INIS)

Dagle, G.E.; Cannon, W.C.; Schirmer, R.E.; Stevens, D.L. Jr.

1979-01-01

Twelve dogs were given a single inhalation exposure to 238 Pu(NO 3 ) 4 to study deposition and translocation up to 1 yr. Preliminary data suggest a greater and more rapid translocation of 238 Pu(NO 3 ) 4 to bone and liver than was observed for 239 Pu(NO 3 ) 4

Plutonium-236 traces determination in plutonium-238 by α spectrometry

International Nuclear Information System (INIS)

Acena, M.L.; Pottier, R.; Berger, R.

1969-01-01

Two methods are described in this report for the determination of plutonium-236 traces in plutonium-238 by a spectrometry using semi-conductor detectors. The first method involves a direct comparison of the areas under the peaks of the α spectra of plutonium-236 and plutonium-238. The electrolytic preparation of the sources is carried out after preliminary purification of the plutonium. The second method makes it possible to determine the 236 Pu/ 238 Pu ratio by comparing the areas of the α peaks of uranium-232 and uranium-234, which are the decay products of the two plutonium isotopes respectively. The uranium in the source, also deposited by electrolysis, is separated from a 1 mg amount of plutonium either by a T.L.A. extraction, or by the use of ion-exchange resins. The report ends with a discussion of the results obtained with plutonium of two different origins. (authors) [fr

Análisis de las variaciones en el número de repeticiones de 5 marcadores ancestrales en donadores recurrentes en México

Directory of Open Access Journals (Sweden)

M.I. Zauza-Carrasco

2015-12-01

Conclusiones: En la comparación de las frecuencias de los polimorfismos en una muestra de origen mestizo mexicana con otra población latina, las diferencias encontradas nos muestran la necesidad de crear bases de datos de referencia de nuestra población, teniendo en cuenta el mestizaje que nos caracteriza.

Caracterización del complejo mayor de histocompatibilidad clase II en primates del género Aotus

OpenAIRE

Suárez Martínez, Carlos Fernando

2017-01-01

El presente trabajo tiene como propósito contribuir al conocimiento del complejo mayor de histocompatibilidad clase II (CMH-II) de los monos Aotus, contribuyendo a la validación de este primate como modelo experimental, y aumentando el conocimiento en la evolución de los genes del CMH en primates. Además, se profundizó en el análisis de convergencia y polimorfismo de los genes del CMH-DR en primates. Se implementaron metodologías de modelación computacional de la unión CMH-péptido, como ...

Genotipificación de los polimorfismos -511, -31 y +3954 del gen de la interleucina-1β humana en una población colombiana con cuadro de dispepsia

Directory of Open Access Journals (Sweden)

María Teresa Arango

2010-08-01

Conclusión. No se encontraron diferencias significativas en los genotipos de los individuos infectados y los no infectados por H. pylori, a excepción del genotipo CC en la región polimórfica -31, el cual se encontró con mayor frecuencia en los pacientes con enfermedades benignas.

Assay of Uranium Isotopic Ratios 234U/238U, 235U/238U in Bottom Sediment Samples Using Destructive and Non Destructive Techniques (Nasser Lake)

International Nuclear Information System (INIS)

Agha, A.R.; El-Mongy, S.A.; Kandel, A.E.

2011-01-01

Nasser Lake is the greatest man-made lake in the World. It is considered as the main source of water where the Nile water is impounded behind the Aswan high dam.. Uranium has three naturally occurring isotopes 234 U, 235 U and 238 U with isotopic abundance 0.00548, 0.7200 and 99.2745 atom percent. Dissolved uranium in the lake is primary due to weathering process. Monitoring of the isotopic ratios of uranium is used as a good indicator to trace and evaluate the origin and activities associated with any variation of uranium in the lake environment. The main objective of the present study is to clarify any potential variation of natural uranium 234 U/ 238 U, 235 U/ 238 U ratios in sediment samples of Nasser Lake by using destructive alpha and non destructive gamma- techniques. The results show that the uranium isotopic activity ratios are very close to the natural values. This study can also be used for radiological protection and safety evaluation purposes.

238U-230Th radioactive disequilibria in the volcanic products from Izu arc volcanoes, Japan

International Nuclear Information System (INIS)

Kurihara, Yuichi; Takahashi, Masaomi; Sato, Jun

2007-01-01

The timescale of magmatic processes of Izu arc volcanoes, Japan, was estimated by the 238 U- 230 Th disequilibria in the volcanic products from the volcanoes. The majority of the 230 Th/ 238 U activity ratios of the products were less than unity, being enriched in 238 U relative to 230 Th. The ( 230 Th/ 232 Th)-( 238 U/ 232 Th)diagram for younger Fuji and Izu-Oshima volcanoes formed a whole rock isochrons, and the ages were 1x10 4 and 2x10 4 years, respectively. The ( 230 Th/ 232 Th) - ( 238 U/ 232 Th) data set for younger Fuji volcano formed a cluster on the diagram, while those of Izu-Oshima formed another cluster apparently apart from each other, suggesting that the concentration of U and Th may possibly be un-uniform in the mantle beneath Izu arc. (author)

Polimorfismo de los alelos de los antígenos de leucocitos humanos HLA-DRB1 y su asociación con la artritis reumatoidea juvenil en una muestra de niños mestizos colombianos.

Directory of Open Access Journals (Sweden)

Gloria Garavito

2003-09-01

Full Text Available Se buscó tipificar molecularmente los alelos de los antígenos de leucocitos humanos HLADRB1 en un grupo de niños mestizos colombianos (población resultante de la mezcla genética de amrindios, europeos y africanos con artritis reumatoidea juvenil (ARJ, así como analizar su frecuencia de expresión y compararla con sujetos clínicamente normales e investigar la asociación entre la frecuencia de los alelos con los diferentes subgrupos clínicos de ARJ. El estudio involucró 65 pacientes con ARJ y 65 controles sanos. La tipificación de los alelos HLADRB1 se realizó por medio de la metodología de la reacción en cadena de la polimerasa con sondas de oligonucleótidos de secuencias específicas (PCR-SSOP, utilizando el protocolo recomendado por el XII International Histocompatibilty Workshop, realizado en St. Malo, París, en 1996. Los alelos HLADRB1* 1104 (prueba exacta de Fisher, PEF=0,013, OR=16,79, frecuencia etiológica (FE=0,93 y DRB1*1602 (PEF=0,016, OR=8,98, FE=0,88 se evidenciaron como marcadores de susceptibilidad. HLA-DRB1*1501 (FP=0,466; p=0,005 y HLA DRB1*1402 (FP=0,49; p=0,009 se comportaron como alelos asociados con protección. Al comparar las asociaciones entre alelos y los diferentes subgrupos clínicos se encontró asociación entre ARJ oligoarticular con HLA-DRB1* 1104 (p=0,0034, OR=41,53 , FE=0,97, la ARJ poliarticular se asoció con el alelo HLADRB1* 0404 (p=0,012, OR=8,75, FE=0,88 y en el grupo sistémico, el alelo más expresado fue el HLA-DRB1*1602 (p=0,005, OR=21,33, FE=0,95. La presencia de factor reumatoide estuvo asociado con los alelos HLA-DRB1*0407 (p=0,05, OR=11,2, FE=0,45 y HLA-DRB1*1302 (p=0,02, OR=22,8, FE=0,63. En el grupo de pacientes con ANA+, sólo hubo significancia estadística para el alelo HLA-DRB1* 0701 (p=0,001, OR=58, FE=0,73. Nuestros resultados sugieren que los genes del MHC en este subgrupo étnico inciden no sólo en la susceptibilidad a desarrollar ARJ sino también en la expresión cl

238U + n resolved resonance energies

International Nuclear Information System (INIS)

Olsen, D.K.; de Saussure, G.; Perez, R.B.; Difilippo, F.C.; Ingle, R.W.

1978-01-01

Neutron transmission measurements from 100 eV to 170 keV at 150 m through four 238 U samples are reported. The energy calibration is described, and the resultant 233 U resolved resonance energies are found to be intermediate between those from other workers. In addition, some energies for sharp resonances in 23 Na, 27 Al, 32 S, and 206 Pb are given

Accumulation and transport of soil plutonium in liquid waste discharge areas at Los Alamos

International Nuclear Information System (INIS)

Hakonson, T.E.; Nyhan, J.W.; Purtymun, W.D.

1975-01-01

Plutonium inventory estimates for the upper 12.5 cm of sediment in Mortandad Canyon, Los Alamos, New Mexico, did not reflect all the Pu added to the canyon during a 7 month interval. The methods used in this study indicate that about 2 mCi 238 Pu and 0 mCi 239 ' 240 Pu were added to the canyon during the interval compared with known additions of 5.5 mCi 238 Pu and 0.4 mCi 239 ' 240 Pu. The discrepancy likely was the result of the large sampling variability indicating that inventory changes in this order (i.e. up to 17 percent) are not detectable with any certainty. However, factors other than sampling variability may be involved, including losses of plutonium to depths exceeding 12.5 cm

/sup 238/Pu fuel-form processes. Quarterly report, October-December 1981

Energy Technology Data Exchange (ETDEWEB)

1982-05-01

Progress in the Savannah River /sup 238/Pu Fuel Form Program is summarized. Work during this period concentrated on the extensive cracking of the /sup 238/PuO/sub 2/ fuel form prior to encapsulation in the iridium containment shell for heat sources. This cracking results in increased recycle cost and decreased production efficiency. To better understand this cracking, Savannah River Laboratory (SRL) has made an extensive review of the development of /sup 238/PuO/sub 2/ fuel forms from small-scale Multi-hundred Watt (MHW) pellets through the current GPHS full-scale pellet production. Historically, /sup 238/PuO/sub 2/ fuel has almost always been uncracked after hot pressing in a graphite die, but has emerged cracked and fragile from the final heat-treatment furnace. The cracking tendency depends on the microstructure of the fuel form and on the hot pressing conditions used to fabricate it. In general, a microstructure of large intershard porosity is more desirable because it allows internal gas to escape more readily and it can absorb more reoxidation strain. Studies of the GPHS microstructure showed that the internal structures of typical GPHS Pellets fabricated at LANL and in the PEF differed significantly. The LANL pellets had severe density gradients and were extensively cracked.

Irradiation of blood by 238Pu alpha particles

International Nuclear Information System (INIS)

Hungate, F.P.; Riemath, W.F.; Culver, G.G.; Gillis, M.F.; Ragan, H.A.

1976-01-01

A developmental 238 Pu blood irradiator produced no evidence of lymphopenia in a dog. Irradiation continued for a year at an estimated rate of about 100 rads/day, but this dosimetry is highly uncertain

Inclusive quasifree electrofission cross section for 238U

International Nuclear Information System (INIS)

Likhachev, V.P.; Carvalho, W.R. Jr.; Deppman, A.; Hussein, M.S.; Macedo, L.F.R.; Mesa, J.; Vaudeluci, M.S.; Arruda-Neto, J.D.T.; Evseev, I.G.; Pashchuk, S.A.; Schelin, H.R.; Garcia, F.; Rodriguez, O.; Margaryan, A.; Nesterenko, V.O.

2003-01-01

We present results from a joint theoretical and experimental study of inclusive quasifree electrofission of 238 U. The off-shell cross sections for the quasifree reaction stage have been calculated within the plane wave impulse approximation with distortion corrections included in the effective momentum approximation. Proton and neutron single-particle momentum distributions were calculated in the macroscopic-microscopic approach. The fissility for proton and neutron single hole excited states of the residual nuclei 237 Pa and 237,238 U was calculated within the compound nucleus model. Final state interaction corrections to residual nucleus excitation energy were calculated using the imaginary part of the optical potential. The total inclusive electrofission cross section was measured with high absolute precision, and all principal partial contributions are analyzed, in particular, the quasifree one

Design of a Pu-238 waste incineration process

International Nuclear Information System (INIS)

Charlesworth, D.L.; McCampbell, R.B.

1985-01-01

Combustible 238 Pu waste is generated as a result of normal operation and decommissioning activity at the Savannah River Plant and is being retrievably stored at the Plant. As part of the long-term plan to process the stored waste and current waste in preparation for future disposition, a 238 Pu incinceration process is being cold-tested at SRL. The incineration process consists of a continuous-feed preparation system, a two-stage, electrically fired incinerator, and a filtration off-gas system. Process equipment has been designed, fabricated, and installed for nonradioactive testing and cold run-in. Design features to maximize the ability to remotely maintain the equipment were incorporated into the process. Interlock, alarm, and control functions are provided by a programmable controller. Cold testing is scheduled to be completed in 1986

238Pu fuel form activities, March 1-September 30, 1985

International Nuclear Information System (INIS)

1986-01-01

The SRP portion of this report summarizes production 238 PuO 2 fuel forms for use in radioisotopic thermoelectric generators (RTG's) in the Plutonium Fuel Form (PuFF) Facility at the Savannah River Plant. The PuFF Facility began producing iridium-encapsulated, 62.5-watt 238 PuO 2 right circular cylinders for GPHS (General Purpose Heat Source) RTG's in June 1980; this program was completed in December 1983. The PuFF Facility has been placed in a production readiness mode of operation pending funding of additional heat source programs

The U238 antineutrino spectrum in the Double Chooz experiment

Energy Technology Data Exchange (ETDEWEB)

Haag, Nils; Oberauer, Lothar; Potzel, Walter; Schreckenbach, Klaus [Technische Universitaet, Muenchen (Germany); Lachenmaier, Tobias [Eberhard Karls Universitaet, Tuebingen (Germany)

2011-07-01

The DoubleChooz experiment aims at the determination of the unknown neutrino mixing parameter {Theta}{sub 13}. Two liquid scintillator detectors will measure an electron antineutrino disappearance at the Chooz site in the French ardennes. In order to improve the sensitivity, the antineutrino spectrum emitted by the Chooz reactor cores has to be determined with high accuracy. This talk focusses on the U238 spectrum, which is the only contributing spectrum, that was not measured until now. The final U238 beta spectrum is presented, and its implementation into the analysis framework is shown.

Internal dose assessment of 238U contaminated soils based on in-vitro gastrointestinal protocol

Science.gov (United States)

Perama, Yasmin Mohd Idris; Rashid, Nur Shahidah Abdul; Majid, Amran Ab.; Siong, Khoo Kok

2017-01-01

Human exposure to natural radioactive uranium has been a great interest as more industrial rapidly growing contributes to radiation risks. The aim of this case study was to determine the internal dose in humans incorporated with ingestion of 238U contaminated soils. A gastrointestinal analogue test was employed to simulate the human digestive tract. In-vitro approach via German DIN 19738 model was developed in order to estimate the internal exposure of 238U due to ingestion of different types of soils. Synthetic gastrointestinal fluids assay via in-vitro method were produced to determine the concentration of 238U in various soils using ICP-MS. Based on the results, concentration of 238U in BRIS, laterite, peat and alluvium soils were in ranged between (0.0061 ± 0.0057 - 0.0488 ± 0.0148) ppm and (0.0005 ± 0.0004 - 0.0046 ± 0.0007) ppm in gastric and gastrointestinal phase respectively. Types of soil compositions and pH medium were some of the factors that influence mobilization and solubility of 238U contaminanted soil into the digestive juices that resembles human gastrointestinal tract. For the purpose of internal dose assessment, the committed efective dose from 238U intake in soils ranged between 1.237 × 10-11 - 9.8993 × 10-11 Sv y-1 for gastric phase and 1.0184 × 10-12 - 9.3294 × 10-12 Sv y-1 for gastric-intestinal phase. The internal dose measurements from this study were much lower from the recommended values. Hence, ingestion of 238U contaminated soils would not be expected to pose major health risk to humans.

Uranium contents and 234U/238U activity ratios of modern and fossil marine bivalle molluscan shells

International Nuclear Information System (INIS)

Mitsuda, Hiroshi

1984-01-01

Uranium contents and 234 U/ 238 U activity ratios in modern and fossil marine bivalle molluscan shells were measured by alpha-spectrometry. Uranium contents and 234 U/ 238 U activity ratios in modern shells were averaged to be 0.266 (dpm/g), and 1.18, respectively and those in fossil shells were averaged to be 0.747 (dpm/g), and 1.19, respectivily. Uranium contents in fossil shells were obviously higher than those in modern shells. It can be explained by the addition of uranium to shell during the deposition. In fossil shells, 234 U/ 238 U activity ratio decreases as 238 U content increases the same tendency is not found in modern shells. The author proposed a mechanism of selective loss of 238 U from the fossil shells for the explanation of this tendency. The height activity ratio of 234 U/ 238 U measured on the fossil shells than that measured on the modern shells, also support the selective loss of 238 U from the fossil shells. (author)

Neutron capture cross-section measurements for 238U between 0.4 and 1.4 MeV

Science.gov (United States)

Krishichayan, Fnu; Finch, S. W.; Howell, C. R.; Tonchev, A. P.; Tornow, W.

2017-09-01

Neutron-induced radiative-capture cross-section data of 238U are crucial for fundamental nuclear physics as well as for Stewardship Science, for advanced-fuel-cycle calculations, and for nuclear astrophysics. Based on different techniques, there are a large number of 238U(n, γ) 239U cross-section data available in the literature. However, there is a lack of systematic and consistent measurements in the 0.1 to 3.0 MeV energy range. The goal of the neutron-capture project at TUNL is to provide accurate 238U(n, γ) 239U cross-section data in this energy range. The 238U samples, sandwiched between gold foils of the same size, were irradiated for 8-14 hours with monoenergetic neutrons. To avoid any contribution from thermal neutrons, the 238U and 197Au targets were placed inside of a thin-walled pill-box made of 238U. Finally, the whole pill-box was wrapped in a gold foil as well. After irradiation, the samples were gamma-counted at the TUNL's low-background counting facility using high-efficient HPGe detectors. The 197Au monitor foils were used to calculate the neutron flux. The experimental technique and 238U(n, γ) 239U cross-section results at 6 energies will be discussed during the meeting.

Pu-238 assay performance with the Canberra IQ3 system

Energy Technology Data Exchange (ETDEWEB)

Booth, L.; Gillespie, B.; Seaman, G.

1997-11-01

Canberra Industries has recently completed a demonstration project at the Westinghouse Savannah River Site (WSRC) to characterize 55-gallon drums containing Pu-238 contaminated waste. The goal of this project was to detect and quantify Pu-238 contaminated waste. The goal of this project was to detect and quantify Pu-238 waste to detection limits of less than 50 nCi/g using gamma assay techniques. This would permit reclassification of these drums from transuranic (TRU) waste to low-level waste (LLW). The instrument used for this assay was a Canberra IQ3 high sensitivity gamma assay system, mounted in a trailer. The results of the measurements demonstrate achievement of detection levels as low as 1 nCi/g for low density waste drums, and good correlation with known concentrations in several test drums. In addition, the data demonstrates significant advantages for using large area low-energy germanium detectors for achieving the lowest possible MDAs for gamma rays in the 80-250 keV range. 1 fig., 2 tabs.

Application of molten salt oxidation for the minimization and recovery of plutonium-238 contaminated wastes

International Nuclear Information System (INIS)

Wishau, R.

1998-05-01

Molten salt oxidation (MSO) is proposed as a 238 Pu waste treatment technology that should be developed for volume reduction and recovery of 238 Pu and as an alternative to the transport and permanent disposal of 238 Pu waste to the WIPP repository. In MSO technology, molten sodium carbonate salt at 800--900 C in a reaction vessel acts as a reaction media for wastes. The waste material is destroyed when injected into the molten salt, creating harmless carbon dioxide and steam and a small amount of ash in the spent salt. The spent salt can be treated using aqueous separation methods to reuse the salt and to recover 99.9% of the precious 238 Pu that was in the waste. Tests of MSO technology have shown that the volume of combustible TRU waste can be reduced by a factor of at least twenty. Using this factor the present inventory of 574 TRU drums of 238 Pu contaminated wastes is reduced to 30 drums. Further 238 Pu waste costs of $22 million are avoided from not having to repackage 312 of the 574 drums to a drum total of more than 4,600 drums. MSO combined with aqueous processing of salts will recover approximately 1.7 kilograms of precious 238 Pu valued at 4 million dollars (at $2,500/gram). Thus, installation and use of MSO technology at LANL will result in significant cost savings compared to present plans to transport and dispose 238 Pu TRU waste to the WIPP site. Using a total net present value cost for the MSO project as $4.09 million over a five-year lifetime, the project can pay for itself after either recovery of 1.6 kg of Pu or through volume reduction of 818 drums or a combination of the two. These savings show a positive return on investment

Update neutron nuclear data evaluation for 236,238Np

International Nuclear Information System (INIS)

Chen, Guochang; Wang, Jimin; Yu, Baosheng; Cao, Wentian; Tang, Guo-you

2015-01-01

The nuclear data with high accuracy for actinides play an important role in nuclear technology applications, including reactor design and operation, fuel cycle, estimation of the amount of minor actinides (MAs) in high burnup reactors and to research to transmute the MAs to short half-lived nuclides or stable ones. The nuclides of 236 Np are generated via the α-decay of 240 Am or 237 Np(n, 2n) and 237 Np(d, t) reactions. And the nuclides of 238 Np are generated via the α-decay of 242 Am or 237 Np(n, γ) and 237 Np(d, p) reactions. In the present work, according to the systematic trend of the total cross section and elastic cross section etc. of different Np isotopes, and based on the neutron optical model parameters (OMP) of 237 Np, a new set of neutron optical model parameters were obtained for 236,238 Np. Based on the new set OMP and the systematic trend of the cross sections of different Np isotopes, a full set of 236,238 Np neutron nuclear data has been updated and improved by theoretical calculation. The present result has significant improvements over the data in CENDL-3.1

Hematological responses after inhaling {sup 238}PuO{sub 2}: An extrapolation from beagle dogs to humans

Energy Technology Data Exchange (ETDEWEB)

Scott, B.R.; Muggenburg, B.A.; Welsh, C.A.; Angerstein, D.A.

1994-11-01

The alpha emitter plutonium-238 ({sup 238}Pu), which is produced in uranium-fueled, light-water reactors, is used as a thermoelectric power source for space applications. Inhalation of a mixed oxide form of Pu is the most likely mode of exposure of workers and the general public. Occupational exposures to {sup 238}PuO{sub 2} have occurred in association with the fabrication of radioisotope thermoelectric generators. Organs and tissue at risk for deterministic and stochastic effects of {sup 238}Pu-alpha irradiation include the lung, liver, skeleton, and lymphatic tissue. Little has been reported about the effects of inhaled {sup 238}PuO{sub 2} on peripheral blood cell counts in humans. The purpose of this study was to investigate hematological responses after a single inhalation exposure of Beagle dogs to alpha-emitting {sup 238}PuO{sub 2} particles and to extrapolate results to humans.

Plutonium-238 and plutonium-239 metabolism in dairy cows following ingestion of mixed oxides

International Nuclear Information System (INIS)

Patzer, R.G.; Mullen, A.A.; Sutton, W.W.; Potter, G.D.; Mosley, R.E.; Efurd, D.W.; Stalnaker, N.D.

1985-01-01

Dairy cows were given oral dosage of plutonium-238 and plutonium-239 dioxide particles in a study to determine the relative gastrointestinal absorption and tissue distribution of the nuclides. Two cows were given particles in which the two isotopes were homogeneously mixed within the particles. A third cow was given two batches of particles which contained either plutonium-238 or plutonium-239. Results indicate that, when the two isotopes of plutonium are homogeneous within the particles, there is no difference between plutonium-238 and plutonium-239 in the relative gastrointestinal absorption and tissue distribution

Polimorfismo g.17924a>g en el gen fasn y su relación con la composición de ácidos grasos (MUFA y CLA) En la carne de novillos aberdeen angus

OpenAIRE

Inostroza, Karla; Larama, Giovanni; Sepúlveda, Néstor

2013-01-01

El interés en la composición de ácidos grasos de la carne bovina está relacionado con producir alimentos más saludables, por ejemplo, con altos contenidos de ácidos grasos monoinsaturados (MUFA) y ácido linoleico conjugado (CLA), debido a que la carne es considerada un alimento con un excesivo contenido graso. El principal objetivo fue determinar la relación del polimorfismo g.17924A>G en el gen FASN con la composición de ácidos grasos en la carne de bovinos Aberdeen Angu...

Influencia del polimorfismo del receptor de andrógenos en la masa ósea, masa muscular y condición física en niños y niñas

OpenAIRE

Rodríguez García, Lorena

2015-01-01

Programa de doctorado: Actividad Física, Salud y Rendimiento Deportivo Premio Extraordinario de Doctorado. Rama Ciencias Sociales y Jurídicas [ES]Para determinar el efecto de ciertos polimorfismos del gen del receptor de andrógenos sobre la masa muscular y la masa ósea, se estudió una muestra poblacional de 152 niños y 116 niñas sanos y físicamente activos (estudios I y II). La composición corporal se determinó mediante absorciometría fotónica dual de rayos X (DXA) y antropometría. La c...

Target/blanket conceptual design for the Los Alamos ATW concept

International Nuclear Information System (INIS)

Ames, K.; Cappiello, M.; Ireland, J.; Sapir, J.; Farnum, G.

1992-01-01

The Los Alamos Accelerator Transmutation of Waste (ATW) concept has many potential applications that include defense waste transmutation, defense material production (i.e., tritium and 238 Pu), and the transmutation of hazardous nuclear wastes from commercial nuclear reactors (fission products and actinides). A more advanced long-term Los Alamos effort is investigating the potential of an accelerator- driven system to produce fission energy with a minimal nuclear waste stream. All applications employ a high-energy (800- to 1600-MeV), high-current (25--250 mA) proton linear accelerator as the driver. In this report, we discuss only the target/blanket conceptual design for the commercial nuclear waste application. A conceptual design for the target/blanket of the Los Alamos ATW concept has been presented. The neutronics, mechanical design, and heat transfer have been investigated in some detail for the base-case design. Much more work needs to be done, but at this point it appears that the design is feasible and will approach the design goal of supporting two commercial power reactors with each target/blanket module

Development of AN Active 238UF6 Gas Target

Science.gov (United States)

Eckardt, C.; Enders, J.; Freudenberger, M.; Göök, A.; von Neumann-Cosel, P.; Oberstedt, A.; Oberstedt, S.

2014-09-01

Detailed studies of the fission process, e.g., the search for parity nonconservation (PNC) effects, the energy dependence of fission modes or the population of fission isomers, depend on high quality data, therefore requiring high luminosities. An active gas target containing uranium may overcome the deterioration of energy and angular resolution caused by large solid target thicknesses. A single Frisch-grid ionization chamber has been built to test a mixture of standard counting gases (e.g., argon) with depleted uranium hexafluoride (238UF6), utilizing a triple alpha source to evaluate signal quality and drift velocity. For mass fractions of up to 4 percent of 238U the drift velocity increases with rising UF6 content, while a good signal quality and energy resolution is preserved.

Application of molten salt oxidation for the minimization and recovery of plutonium-238 contaminated wastes

International Nuclear Information System (INIS)

Wishau, R.; Ramsey, K.B.; Montoya, A.

1998-01-01

This paper presents the technical and economic feasibility of molten salt oxidation technology as a volume reduction and recovery process for 238 Pu contaminated waste. Combustible low-level waste material contaminated with 238 Pu residue is destroyed by oxidation in a 900 C molten salt reaction vessel. The combustible waste is destroyed creating carbon dioxide and steam and a small amount of ash and insoluble 2328 Pu in the spent salt. The valuable 238 Pu is recycled using aqueous recovery techniques. Experimental test results for this technology indicate a plutonium recovery efficiency of 99%. Molten salt oxidation stabilizes the waste converting it to a non-combustible waste. Thus installation and use of molten salt oxidation technology will substantially reduce the volume of 238 Pu contaminated waste. Cost-effectiveness evaluations of molten salt oxidation indicate a significant cost savings when compared to the present plans to package, or re-package, certify and transport these wastes to the Waste Isolation Pilot Plant for permanent disposal. Clear and distinct cost advantages exist for MSO when the monetary value of the recovered 238 Pu is considered

LSSP-PCR para la identificación de polimorfismos en el gen cry1B en cepas nativas de Bacillus thuringiensis

Directory of Open Access Journals (Sweden)

Martha Ilce Orozco Mera

2012-01-01

Full Text Available Título en ingles: LSSP-PCR to identify polymorphisms in the gene cry1B of Bacillus thuringiensis native strain Resumen: Se estandarizó la técnica LSSP-PCR (reacción en cadena de la polimerasa con un único oligonucleótido en condiciones de baja astringencia, para identificar polimorfismos del gen cry1B en aislamientos nativos de Bacillus thuringiensis (Bt. Se evaluaron 164 aislamientos nativos colombianos identificándose el gen cry1Ba en 11 de estos aislamientos. Los 11 fragmentos amplificados, junto con el de la cepa de referencia Bt subsp. aizawai HD137, se analizaron por LSSP-PCR y los patrones electroforéticos obtenidos se compararon cualitativamente. Con los productos amplificados mediante el oligonucleótido directo se construyó un dendrograma utilizando UPGMA que  mostró tres agrupamientos con similitud de 83, 79 y 68%. La agrupación con 68% de similaridad correspondió al aislamiento nativo BtGC120 que presentó el patrón de bandas más variable. Con el oligonucleótido reverso el aislamiento BtGC120 mostró una menor variabilidad (43%. La secuencia nucleotidica obtenida de este fragmento de 806 pares de bases mostró una identidad de 93% con la secuencia de los genes cry1Bc1 de Bt morrisoni y cry1Bb1 de la cepa BT-EG5847. Se predijo del marco de lectura +3 una proteína de 268 residuos aminoácidicos, con 88% de identidad con la proteína Cry1Bc. Esta  secuencia reveló dos dominios, una endotoxina N implicada en la formación del poro y otra endotoxina M relacionada en el reconocimiento del receptor. La evaluación biológica del aislamiento BtGC120 sobre larvas de primer instar del insecto plaga Spodoptera frugiperda, mostró una CL50 de 1,896 ng de proteína total por cm2. Este estudio muestra que la LSSP-PCR es una técnica que permite identificar de una manera específica variaciones en las secuencias de los genes cry de Bt, con potencialidad de encontrar nuevos genes con novedosas actividades biológicas. Abstract

Common polymorphisms and cardiovascular factors in patients with myocardial infarction of Costa Rica

Directory of Open Access Journals (Sweden)

Lizbeth Salazar-Sánchez

2006-03-01

Full Text Available Eight common polymorphisms of known myocardial infarction (MIrisk factors (factor V Leiden (FVL, factor V HR2 (FVHR2,factor II 20210G>A (FII,factor VII IVS7 (FVII IVS7,factor VII Arg353Gln (FVII, factor XIII Val34Leu (FXIII,Methylenetetrahydrofolate reductase C677T (MTHFR, Angiotensin Converting Enzyme (ACEand environmental risk factors were analyzed in a MI patients of Costa Rica.This case-control study included 186 MI subjects,95 of them Se estudiaron ocho polimorfismos comunes asociados como factores de riesgo para el infarto al miocardio (IM:factor V Leiden (FVL,factor VHR2 (FVHR2, factor II 20210G>A (FII,factor VII IVS7 (FVII IVS7, factor VIIArg353Gln (FVII,factor XIIIVal34Leu (FXIII, metilentetrahidrofolato reductase C677T (MTHFR, enzima convertidora de la angiotensina (ACE y factores ambientales de riesgo,en pacientes costarricenses.Este es un estudio de casos y controles,donde participan 186 pacientes,95 de ellos con edades <45 años y 201 sujetos controles.Se utilizó la técnica de reacción en cadena de la polimerasa (PCRy por medio de entrevistas personales se recolectó información epidemiológica adicional.Se encontró que la hipercolesterolemia y el fumado estan asociados como factores de riesgo en los pacientes jóvenes.Niveles elevados del fibrinógeno fueron detectados como un factor de riesgo importante y se observo interacción entre fumado y estos valores aumentados de fibrinógeno. El genotipo 34LeuLeu del FXIII presentó un efecto protector significante mientras que los otros polimorfimos estudiados no mostraron diferencia estadísticamente significativa entre los casos y controles. Los polimorfismos del FVII y FXIII demostraron interación con el fibrinógeno,según el análisis estadístico aplicado. Se evidencia, la interación entre factores de riesgo común y ciertos polimorfismos (FVII;FXIIIen la patogénesis del IM.Este es uno de los primeros informes sobre estos marcadores moleculares y su asociación con IM en

Susceptibilidad genética y riesgo de cáncer gástrico en una población del Cauca.

Directory of Open Access Journals (Sweden)

María M. Torres

2004-06-01

Full Text Available El cáncer gástrico es la principal causa de mortalidad por cáncer en Colombia. El riesgo de desarrollar cáncer gástrico se ha asociado con factores ambientales y con la infección por Helicobacter pylori. Las enzimas glutatión-S-transferasas están involucradas en la desintoxicación de varios carcinógenos ambientales. Las deleciones homocigóticas de glutatión-S-transferasa M1 (GSTM1-0 y glutatión-S-transferasa T1 (GSTT1-0 se han asociado con algunos tipos de cáncer. Los niveles del factor de necrosis tumoral (FNT ? están aumentados en pacientes infectados por H. pylori. Una transición G/A en la posición -308 del promotor del FNT-? se ha visto relacionada en algunos estudios con un incremento en la expresión del gen, y está asociada con la susceptibilidad a cáncer gástrico. Se investigó la asociación de estos polimorfismos con cáncer gástrico y la interacción con otros factores de riesgo (estilo de vida. Se obtuvieron muestras de sangre de 46 pacientes con cáncer gástrico y 96 controles. Se empleó el modelo de regresión logística para obtener la razón de posibilidades (OR y sus intervalos de confianza del 95% y, así, establecer la asociación entre los polimorfismos enzimáticos y el cáncer gástrico, y entre otros factores independientes y esta enfermedad. Las frecuencias de los polimorfismos de deleción en pacientes y controles fueron: para la GSTM1, 65,2% y 37,5%, y para la GSTT1, 17,4% y 14,6%, respectivamente. La frecuencia del polimorfismo G/A del FNT ? en las personas infectadas con H. pylori fue de 18% en la población con cáncer gástrico y de 7% en el grupo control. Nuestros resultados sugieren que el polimorfismo de deleción de GSTM1 puede estar asociado con un riesgo aumentado de cáncer gástrico (OR 5,5; IC95%, 1,7-17,2. Igualmente, nuestros datos muestran que otros factores de riesgo como la infección por H. pylori y el consumo de cigarrillo y alcohol están asociados con este tipo de cáncer (OR

Validity of the Generalized Brink-Axel Hypothesis in (238)Np.

Science.gov (United States)

Guttormsen, M; Larsen, A C; Görgen, A; Renstrøm, T; Siem, S; Tornyi, T G; Tveten, G M

2016-01-08

We analyze primary γ-ray spectra of the odd-odd (238)Np nucleus extracted from (237)Np(d,pγ)(238)Np coincidence data measured at the Oslo Cyclotron Laboratory. The primary γ spectra cover an excitation-energy region of 0≤E(I)≤5.4  MeV, and allow us to perform a detailed study of the γ-ray strength as a function of excitation energy. Hence, we can test the validity of the generalized Brink-Axel hypothesis, which, in its strictest form, claims no excitation-energy dependence on the γ strength. In this work, using the available high-quality (238)Np data, we show that the γ-ray strength function is to a very large extent independent of the initial and final states. Thus, for the first time, the generalized Brink-Axel hypothesis is experimentally verified for γ transitions between states in the quasicontinuum region, not only for specific collective resonances, but also for the full strength below the neutron separation energy. Based on our findings, the necessary criteria for the generalized Brink-Axel hypothesis to be fulfilled are outlined.

Application of molten salt oxidation for the minimization and recovery of plutonium-238 contaminated wastes

Energy Technology Data Exchange (ETDEWEB)

Wishau, R.

1998-05-01

Molten salt oxidation (MSO) is proposed as a {sup 238}Pu waste treatment technology that should be developed for volume reduction and recovery of {sup 238}Pu and as an alternative to the transport and permanent disposal of {sup 238}Pu waste to the WIPP repository. In MSO technology, molten sodium carbonate salt at 800--900 C in a reaction vessel acts as a reaction media for wastes. The waste material is destroyed when injected into the molten salt, creating harmless carbon dioxide and steam and a small amount of ash in the spent salt. The spent salt can be treated using aqueous separation methods to reuse the salt and to recover 99.9% of the precious {sup 238}Pu that was in the waste. Tests of MSO technology have shown that the volume of combustible TRU waste can be reduced by a factor of at least twenty. Using this factor the present inventory of 574 TRU drums of {sup 238}Pu contaminated wastes is reduced to 30 drums. Further {sup 238}Pu waste costs of $22 million are avoided from not having to repackage 312 of the 574 drums to a drum total of more than 4,600 drums. MSO combined with aqueous processing of salts will recover approximately 1.7 kilograms of precious {sup 238}Pu valued at 4 million dollars (at $2,500/gram). Thus, installation and use of MSO technology at LANL will result in significant cost savings compared to present plans to transport and dispose {sup 238}Pu TRU waste to the WIPP site. Using a total net present value cost for the MSO project as $4.09 million over a five-year lifetime, the project can pay for itself after either recovery of 1.6 kg of Pu or through volume reduction of 818 drums or a combination of the two. These savings show a positive return on investment.

Surrogate measurement of the 238Pu(n,f) cross section

International Nuclear Information System (INIS)

Ressler, J. J.; Burke, J. T.; Escher, J. E.; Bernstein, L. A.; Bleuel, D. L.; Casperson, R. J.; Gostic, J.; Henderson, R.; Scielzo, N. D.; Thompson, I. J.; Wiedeking, M.; Angell, C. T.; Goldblum, B. L.; Munson, J.; Basunia, M. S.; Phair, L. W.; Beausang, C. W.; Hughes, R. O.; Hatarik, R.; Ross, T. J.

2011-01-01

The neutron-induced fission cross section of 238 Pu was determined using the surrogate ratio method. The (n,f) cross section over an equivalent neutron energy range 5-20 MeV was deduced from inelastic α-induced fission reactions on 239 Pu, with 235 U(α,α ' f) and 236 U(α,α ' f) used as references. These reference reactions reflect 234 U(n,f) and 235 U(n,f) yields, respectively. The deduced 238 Pu(n,f) cross section agrees well with standard data libraries up to ∼10 MeV, although larger values are seen at higher energies. The difference at higher energies is less than 20%.

238U subthreshold neutron induced fission cross section

International Nuclear Information System (INIS)

Difilippo, F.C.; Perez, R.B.; De Saussure, G.; Olsen, D.K.; Ingle, R.W.

1976-01-01

High resolution measurements of the 238 U neutron induced fission cross section are reported for neutron energies between 600 eV and 2 MeV. The average subthreshold fission cross section between 10 and 100 keV was found to be 44 +- 6 μb

49 CFR Figure 1a to Subpart B of... - Example of Location of Rescue Access Windows-§ 238.114

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Example of Location of Rescue Access Windows-§ 238.114 1A Figure 1A to Subpart B of Part 238 Transportation Other Regulations Relating to... B of Part 238—Example of Location of Rescue Access Windows—§ 238.114 ER01FE08.002 [73 FR 6403, Feb...

49 CFR Appendix E to Part 238 - General Principles of Reliability-Based Maintenance Programs

Science.gov (United States)

2010-10-01

... STANDARDS Pt. 238, App. E Appendix E to Part 238—General Principles of Reliability-Based Maintenance... 49 Transportation 4 2010-10-01 2010-10-01 false General Principles of Reliability-Based... the design level of safety and reliability of the equipment; (2) To restore safety and reliability to...

Polimorfismos de grupos sanguíneos en Cachi, Valle Calchaqui, Salta

OpenAIRE

Acreche, Noemí; Albeza, María V.; Caruso, Graciela; Acosta, Rebeca; Felix, Sebastián

2001-01-01

El Departamento de Cachi, en la Provincia de Salta pertenece a los Valles Calchaquíes, los que se extienden además por Catamarca y Tucumán, constituyéndose en una región importante en la comunicación entre el Valle de Lerma y la Puna. Hasta el momento no se conocen datos de la genética de estas poblaciones, salvo los publicados por Matson en 1968 registrados en otra región de la provincia. A partir de la determinación de los grupos: ABO, MN, Ss, Cc, Dd, Ee, P, Diego y Kell-Cellano, Duffy y...

43 CFR 30.238 - Does any distribution of the estate occur while a petition for rehearing is pending?

Science.gov (United States)

2010-10-01

... while a petition for rehearing is pending? 30.238 Section 30.238 Public Lands: Interior Office of the... Proceedings § 30.238 Does any distribution of the estate occur while a petition for rehearing is pending? The... pending, unless otherwise directed by the judge. ...

Application of a canine ²³⁸Pu dosimetry model to human bioassay data

Energy Technology Data Exchange (ETDEWEB)

Hickman, Jr., A. W. [Florida Univ., Gainesville, FL (United States)

1991-08-01

Associated with the use of 2²³⁸Pu in thermoelectric power sources for space probes and power supplies for cardiac devices is the potential for human exposure to ²³⁸Pu, primarily by inhalation. In the event of human internal exposure, a means is needed for assessing the level of intake and calculating radiation doses. Several bioassay/dosimetry models have been developed for ²³⁹Pu. However, results from studies with laboratory animals have indicated that the biokinetics, and therefore the descriptive models, of ²³⁸Pu are significantly different from those for ²³⁹Pu. A canine model accounting for these differences has been applied in this work to urinary excretion data from seven humans occupationally exposed to low levels of an insoluble ²³⁸Pu compound. The modified model provides a good description of the urinary excretion kinetics observed in the exposed humans. The modified model was also used to provide estimates of the initial intakes of ²³⁸Pu for the seven individuals; these estimates ranged from 4.5 nCi (170 Bq) to 87 nCi (3200 Bq). Autopsy data on the amount and distribution of ²³⁸Pu retained in the organs may be used in the future to validate or refute both these estimates and the assumptions used to formulate the human model. Modification of the human model to simulate an injection exposure to ²³⁹Pu gave patterns of retention in the organs and urinary excretion comparable to those seen previously in humans; further modification of the model using fecal data (unavailable for the subjects of this study) is indicated.

Caracterización de accesiones de papaya (Carica papaya L.) a través de marcadores AFLP en Cuba

OpenAIRE

Maruchi Alonso Esquivel; Martín Bautista Alor; Matilde Ortiz García; Adriana Quiroz Moreno; Wolfgang Rohde; Lorenzo Felipe Sánchez Teyer

2010-01-01

Los marcadores moleculares son herramientas valiosas en los estudios genéticos en plantas, y están siendo empleados exitosamente en programas de mejoramiento principalmente en la elección de progenitores y en la selección. El polimorfismo observado mediante la técnica molecular AFLP (Amplified Fragment Length Polymorphism) ha sido de utilidad para estudios de diversidad genética en frutales. En el presente trabajo se realizó la caracterización molecular de 12 accesiones de papaya (Carica papa...

Caracterización de accesiones de papaya (Carica papaya L.) a través de marcadores AFLP en Cuba

OpenAIRE

Esquivel, Maruchi Alonso; Bautista Alor, Martín; Ortiz García, Matilde; Quiroz Moreno, Adriana; Rohde, Wolfgang; Sánchez Teyer, Lorenzo Felipe

2009-01-01

Los marcadores moleculares son herramientas valiosas en los estudios genéticos en plantas, y están siendo empleados exitosamente en programas de mejoramiento principalmente en la elección de progenitores y en la selección. El polimorfismo observado mediante la técnica molecular AFLP (Amplified Fragment Length Polymorphism) ha sido de utilidad para estudios de diversidad genética en frutales. En el presente trabajo se realizó la caracterización molecular de 12 accesiones de papaya (Carica papa...

Frecuencia y tipos de toxinas superantígenos en Staphylococcus aureus de diferentes orígenes: relaciones con tipos genéticos

OpenAIRE

Fueyo Mendoza, José María

2005-01-01

Staphylococcus aureus de diferentes orígenes (muestras nasales de portadores humanos, alimentos manipulados, y leche de vacas con mastitis subclínica), recogidos en Asturias (1996-2002), han sido analizados mediante técnicas convencionales y moleculares para determinar la frecuencia y los tipos de genes de toxinas pirogénicas superantígenos (PTSAg) que portan y el polimorfismo de su ADN con objeto de establecer relaciones toxigénicas y genómicas entre aislamientos. La interrelación de los res...

Electron scattering from the octupole band in 238U

International Nuclear Information System (INIS)

Hirsch, A.; Creswell, C.; Bertozzi, W.; Heisenberg, J.; Hynes, M.V.; Kowalski, S.; Miska, H.; Norum, B.; Rad, F.N.; Sargent, C.P.; Sasanuma, T.; Turchinetz, W.

1978-01-01

A simple model for nuclear surface vibrations in permanently deformed nuclei does well in reproducing electron scattering cross sections of rotational levels built on a K/sup π/= 0 - intrinsic octupole vibration in 238 U

Primer reporte de empleo de marcadores AFLP en Asteraceae en Cuba

Directory of Open Access Journals (Sweden)

Grecia Montalvo Fernández

2012-07-01

Full Text Available Título en ingles: First report of the employment of AFLP markers in Asteraceae in Cuba. Resumen: Rhodogeron coronopifolius Griseb., es una especie vegetal de la familia Asteraceae, que se encuentra en peligro crítico de extinción. Es endémico de la provincia Villa Clara en la región central de Cuba. Habita en el matorral xeromorfo sub espinoso sobre serpentina. Existen solo cinco poblaciones naturales dentro de un área protegida, la principal causa de amenaza es la fragmentación de su hábitat por acciones antrópicas. Debido a su situación de conservación, se hace necesario realizar estudios de la diversidad genética de las poblaciones naturales para así generar información básica y diseñar una estrategia de conservación. El objetivo de este trabajo fue analizar de manera preliminar la diversidad genética de cuatro poblaciones de esta especie utilizando marcadores AFLP (Polimorfismo de Longitud de Fragmentos Amplificados. Se emplearon dos combinaciones de iniciadores y se evaluó el porcentaje de polimorfismo así como la similitud entre los individuos.  Se obtuvieron 165 loci de los cuales el 78,7 % fueron polimórficos. La población de mayor polimorfismo fue Corojito con 85,2%, de manera general el polimorfismo fue alto con valores entre 75 y  87%. La similitud entre los individuos también fue alta con un promedio de 0,74. El agrupamiento genético fue independiente a la población de procedencia, lo que sugiere que existe intercambio genético entre las poblaciones y que estas comparten más del 80 % de los alelos que fueron analizados. Los resultados obtenidos son importantes para el mantenimiento in situ de la especie y para tomar decisiones en aras de su conservación. Palabras clave: Rhodogeron coronopifolius, peligro de extinción, polimorfismo, conservación. Abstract: Rhodogeron coronopifolius Griseb., is a specie of Asteraceae family, in critical danger of extinction. It is an endemic of Villa Clara city in the

Reclamation of greater than Class C sealed sources at the Los Alamos National Laboratory

International Nuclear Information System (INIS)

Behrens, R.G.; Jones, S.W.

1995-01-01

One of the important overriding themes of the Los Alamos National Laboratory as a world-class scientific institution is to utilize its expertise in enhancing the long-term welfare of society by minimizing negative side effects of nuclear technology over the past five decades. The Los Alamos National Laboratory is therefore committed to the use of its technical competencies and nuclear facilities, developed through programs in the areas of defense and civilian nuclear research, to support activities which will benefit the United States as a whole. As such, this paper discusses the organizational details and requirements of the Neutron Source Reclamation Program at Los Alamos. This program has as its mission the retrieval, interim storage, and chemical reprocessing of 238 PuBe, 239 PuBe and 24l AmBe neutron sources residing in the hands of private companies and industries, academic institutions, and various state and Federal government agencies

Adsorption of Cs-137 and U-238 in semi-arid soils; Adsorcion de Cs-137 y U-238 en suelos semiaridos

Energy Technology Data Exchange (ETDEWEB)

Hernandez T, U. O. [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, 52140 Metepec, Estado de Mexico (Mexico); Monroy G, F.; Anguiano A, J. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Fernandez R, E., E-mail: uohtrejo@gmail.com [Universidad Politecnica del Valle de Toluca, Carretera Toluca-Almoloya de Juarez Km. 5.6, Santiaguito Tlalcilalcali, Estado de Mexico (Mexico)

2013-10-15

Is of great importance to determine the adsorption properties of the soils where radioactive wastes are stored, fundamentally of the radioisotopes contained in these wastes, with the purpose of knowing like will be their behavior in the event of happening radionuclide migration toward the surrounding means. Therefore, in this work the adsorption properties of {sup 137}Cs{sup +} and {sup 238}UO{sub 2}{sup 2+} in soils coming from the Storage Center of Radioactive Wastes are studied. Was studied the effect of the soil type and the particle size of the soil in the adsorption properties of Cs (I) and U (Vi). 13 soil samples and six different particle sizes were analyzed. The adsorption studies were carried out by the radiotracers technique in static way. The results indicate an important adsorption affinity toward the Cs-137 and a very vulnerable affinity for the {sup 238}UO{sub 2}{sup 2+}. (author)

Energy distribution of neutrons from the (n,2n) reaction in 238U

International Nuclear Information System (INIS)

Misulovin, A.

1978-12-01

Energy distribution of the first and second neutrons from (n,2n) scattering event in 238 U was evaluated according to the consistent compound nucleus model recently proposed by Segev. The law for deriving the energy distribution of secondary neutrons from a (n,2n) scattering event, depends on whether the reaction is considered as a simultaneous emission of two neutrons from one compound nucleus, or a successive emission of neutrons from different compound nuclei. Segev has presented a means of calculating the energy distribution assuming the latter model. The laws presented in the ENDF/B data files suggest the former model. The evaluation was based on inelastic level excitation and evaporation data for 238 U and 237 U. Data was retrieved from ENDF/B files. The evaporation data for 237 U was based on (γ,n) reaction 238 U. The inelastic level excitation data for 237 U was evaluated at the Soreq Nuclear Research Centre. It is concluded from the application of Segev's model to 238 U, that the energetic spectrum of secondary neutrons, is harder in the high range of energy than the one predicted by the use of the distribution law presented in ENDF/B data files. The spectrum of secondary (n,2n) neutrons, resulting from the interaction of 14 MeV neutrons in 238 U calculated with Segev's model, is compared with the corresponding spectrum of the LLL library, ENDF/B library and the recent evaluation of BNWL. It is found that the spectrum evaluated by LLL and BNWL is harder than that evaluated with Segev's model

Experimental determination of the antineutrino spectrum of the fission products of 238U

International Nuclear Information System (INIS)

Haag, Nils-Holger

2013-01-01

Fission of 238 U contributes about 10 % to the antineutrino emission of a pressurized water reactor. In the present thesis, the beta spectrum of the fission products of 238 U was determined in an experiment at the neutron source FRM II. This beta spectrum was subsequently converted into an antineutrino spectrum. This first measurement of the antineutrino spectrum supports all current and future reactor antineutrino experiments.

238U and 237Np nuclear fission by 90-270 MeV electrons

International Nuclear Information System (INIS)

Kuznetsov, V.L.; Nedorezov, V.G.; Nikitina, N.V.; Noga, V.I.; Ranyuk, Yu.N.; Telegin, Yu.N.; Smirnov, A.N.; Ehjsmont, V.P.

1981-01-01

A technique for measuring cross sections of 238 U and 237 Np nuclei fission caused by 90-270 MeV electrons is described. Measurement results are given. The results obtained are discussed on the basis of the virtual photon method. It is shown that the difference in cross sections of 238 U and 237 Np electrofission is due to the different contribution of the giant resonance [ru

230Th-238U disequilibria in historical lavas from Iceland

International Nuclear Information System (INIS)

Condomines, M.; Morand, P.; Alleegre, C.J.; Sigvaldason, G.

1981-01-01

The 230 Th- 238 U disequilibrium studies on historical lavas from Iceland show a relative homogeneity for Th/U ratios and also a variation for ( 230 Th/ 232 Th) activity ratios at the scale of the island. The ( 230 Th/ 238 U) disequilibrium ratio is always greater than 1 which indicates that partial melting produces magmas with Th/U ratios greater than those of the mantle source. Furthermore, there seems to be a correlation between the variations of ( 230 Th/ 232 Th) (and delta 18 O) ratios and the geographical location of the samples along the active zones of Iceland. We develop and discuss several models in order to explain these variations. (orig.)

The toxicity of inhaled particles of 238PuO2 in dogs

International Nuclear Information System (INIS)

Muggenburg, B.A.; Guilmette, R.A.; Griffith, W.C. Jr.; Hahn, F.F.; Boecker, B.B.

1991-01-01

This study was conducted to determine the toxicity of inhaled 238 PuO 2 in the dog. Inhalation was selected because it is the mostly likely route of human exposure in the event of an accidental airborne release. Of 166 dog in the study, 72 inhaled 1.5μm and 72 inhaled 3.0 μm activity median aerodynamic diameter particles of 238 PuO 2 . Another 24 dogs inhaled the aerosol vector without plutonium. The aerosol exposures resulted in initial pulmonary burdens ranging from 37 to 0.11 and 55.5 to 0.37 kBq of 238 Pu/kg body mass, of 1.5 μm and 3.0 μ, particles, respectively. The particles dissolved slowly resulting in translocation of the Pu to liver, bone and other sites. The dogs were observed for biological effects over their life span. Necropsies were performed at death, and tissues were examined microscopically. The principal late-occurring effects were tumors of the lung, skeleton, and liver. Risk factors estimated for these cancers were 2800 lung cancers/10 4 Gy, 800 liver cancers/10 4 Gy, and 6200 bone cancers/10 4 Gy for dogs. The potential hazard from 238 Pu to humans may include tumors of the lung, bone and liver because of the likelihood of similarity of the dose patterns for the two species. 10 refs., 1 fig., 3 tabs

The Effect of Early Diagenesis on the 238U/235U Ratio of Platform Carbonates.

Science.gov (United States)

Tissot, F.; Chen, C.; Go, B. M.; Naziemiec, M.; Healy, G.; Swart, P. K.; Dauphas, N.

2017-12-01

In the past 15 years, the so-called non-traditional stable isotopes systems (e.g., Mg, Fe, Mo, U) have emerged as powerful tracers of both high-T and low-T geochemical processes (e.g., [1]). Of particular interest for paleoredox studies is the ratio of "stable" isotopes of U (238U/235U), which has the potential to track the global extent of oceanic anoxia (e.g., [2, 3]). Indeed, in the modern ocean, U exists in two main oxidation states, soluble U6+ and insoluble U4+, and has a mean residence time of 400 kyr ([4]), much longer than the global ocean mixing time (1-2 kyr). As such the salinity-normalized ocean is homogeneous with regards to both U concentrations and isotopes (δ238USW = -0.392±0.005 ‰, [2]). The value of δ238USW at any given time is therefore the balance between U input to the ocean, mainly from rivers, and U removal, mostly into biogenic carbonates, anoxic/euxinic sediments and suboxic/hypoxic sediments (e.g., [2, 5]). Because the 238U/235U ratio of the past ocean cannot be measured directly, it has to be estimated from the measurement of the 238U/235U ratio of a sedimentary rock and assuming a constant fractionation factor. Carbonates appear as a promising record since they span most of Earth's history, and the δ238U values of modern primary carbonate precipitates and well-preserved fossil aragonitic coral up to 600 ka are indistinguishable from that of seawater (e.g., [2, 6, 7]). Yet, the effect of secondary processes on the δ238U values of non-coral carbonates, which represent the bulk of the rock record, has only been studied in a handful of shallow samples (down to 40cm, [6]) and remains poorly understood. To investigate the effect of early diagenesis on the 238U/235U ratio of carbonates on the 30kyr to 1Myr timescale, we measured δ13C, δ18O, and δ238U in samples from a 220m long drill core from the Bahamas carbonate platform. In order to separate lattice bound U from secondary U we developed a leaching protocol applicable to carbonate

High energy resolution measurement of the sup 238 U neutron capture yield from 1 to 100 keV

Energy Technology Data Exchange (ETDEWEB)

Macklin, R.L. (Tennessee Univ., Knoxville, TN (United States). Dept. of Nuclear Engineering); Perez, R.B. (Tennessee Univ., Knoxville, TN (United States). Dept. of Nuclear Engineering Oak Ridge National Lab., TN (United States)); De Saussure, G.; Ingle, R.W. (Oak Ridge National Lab., TN (United States))

1991-01-01

The purpose of this work is the precise determination of the {sup 238}U neutron capture yield (i.e. the probability of neutron capture) as a function of neutron energy with the highest available neutron energy resolution. The motivation for this undertaking arises from the central role played by the {sup 238}U neutron capture process in the neutron balance of both thermal reactors and fast breeder reactors. The present measurement was performed using the Oak Ridge Electron Linear Accelerator (ORELA) facility. The pulsed beam of neutrons from the ORELA facility is collimated on a sample of {sup 238}U. The neutron capture rate in the sample is measured, as a function of neutron time-of-flight (TOF) by detecting the {gamma}-rays from the {sup 238}U(n, {gamma}){sup 239}U reaction with a large {gamma}-ray detector surrounding the {sup 238}U sample. At each energy, the capture yield is proportional to the observed capture rate divided by the measured intensity of the neutron beam. The constant of proportionality (the normalization constant) is obtained from the ratio of theoretical to experimentally measured areas under small {sup 238}U resonances where the resonance parameters have been determined from high-resolution {sup 238}U transmission measurements. The cross section for the reaction {sup 238}U(n,{gamma}){sup 239}U can be derived from the measured capture yield if one applies appropriate corrections for multiple scattering and resonance self-shielding. Some 200 {sup 238}U neutron resonances in the energy range from 250 eV to 10 keV have been observed which had not been detected in previous measurements. (author).

Interação toxicogenética de polimorfismos da metaloproteinase-9 (MMP-9) da matriz extracelular e exposição ao mercúrio : efeitos sobre a atividade plasmática da MMP-9

OpenAIRE

Anna Laura Bechara Jacob Ferreira

2010-01-01

Resumo: A exposição ao mercúrio (Hg) causa efeitos deletérios à saúde, incluindo doenças cardiovasculares. Embora os mecanismos não estejam precisamente definidos, metaloproteinases (MMPs) -2 e -9 podem estar envolvidas. Expressão e atividades aumentadas destas MMPs são demonstradas em diversas condições patológicas, e estudos demonstraram que os níveis circulantes de MMPs poderiam ser usados como marcadores de risco cardiovascular. O gene que codifica a MMP-9 apresenta polimorfismos que afet...

Sensitivity of 238U resonance absorption to library multigroup structure as calculated by WIMS-AECL

International Nuclear Information System (INIS)

Laughton, P.J.; Donnelly, J.V.

1995-01-01

In simulations of the TRX-1 experimental lattice, WIMS-AECL overpredicts, relative to MCNP, resonance absorption in neutron-energy groups containing the three large, low-lying resonances of 238 U when a standard ENDF/B-V-based library is used. A total excess in these groups of 4.0 neutron captures by 238 U per thousand fission neutrons has been observed. Similar comparisons are made in this work for the MIT-4 experimental lattice and simplified CANDU lattice cells containing 37-element fuel, with and without heavy-water coolant. Eleven different 89-group cross-section libraries were constructed for WIMS-AECL from ENDF/B-V data: only the neutron-energy-group boundaries used in generating multigroup cross sections and the Goldstein-Cohen correction factors differ from one library to the next. The first library uses the original 89-group structure, and the other ten involve energy groups of varying widths centred on the three large, low-lying resonances of 238 U. For TRX-1, some reduction in total discrepancy in 238 U capture can be achieved by using a new structure, although the improvement is small. The discrepancies in 238 U capture are of the same order for the MIT-4 case as those observed for TRX-1 for both the original group structure and the ten new structures. The WIMS-AECL calculation of 238 U resonance absorption in the same ranges of energy for the simplified CANDU 37-element lattice are in better agreement with MCNP than they are for TRX-1 and MIT-4: when the original structure is used, WIMS-AECL underpredicts total capture rate by 238 U in the energy range of interest by only 0.56 per thousand fission neutrons (coolant present) and 0.88 per thousand fission neutrons (voided coolant channel). The discrepancies are reduced when some of the new structures are used. For almost all of the cases considered here-TRX-1, MIT-4 and CANDU with coolant-better group-by-group agreement of 238 U capture around the 6.67-eV resonance is achieved by using a new library

An isotopic analysis system for plutonium samples enriched in 238Pu

International Nuclear Information System (INIS)

Ruhter, W.D.; Camp, D.C.

1991-08-01

We have designed and built a gamma-ray spectrometer system that measures the relative plutonium isotopic abundances of plutonium oxide enriched in 238 Pu. The first system installed at Westinghouse Savannah River Company was tested and evaluated on plutonium oxide in stainless steel EP60/61 containers. 238 Pu enrichments ranged from 20% to 85%. Results show that 200 grams of plutonium oxide in an EP60.61 container can be measured with ±0.3% precision and better than ±1.0% accuracy in the specific power using a counting time of 50 minutes. 3 refs., 2 figs

Delayed neutron yield from fast neutron induced fission of 238U

International Nuclear Information System (INIS)

Piksaikin, V.M.; Kazakov, L.E.; Isaev, S.G.; Roshchenko, V.A.; Goverdovski, A.A.; Tertytchnyi, R.G.

2002-01-01

The measurements of the total delayed neutron yield from fast neutron induced fission of 238 U were made. The experimental method based on the periodic irradiation of the fissionable sample by neutrons from a suitable nuclear reaction had been employed. The preliminary results on the energy dependence of the total delayed neutron yield from fission of 238 U are obtained. According to the comparison of experimental data with our prediction based on correlation properties of delayed neutron characteristics, it is concluded that the value of the total delayed neutron yield near the threshold of (n,f) reaction is not a constant. (author)

Relative 238Pu content of bone and bone marrow

International Nuclear Information System (INIS)

McClanahan, B.J.

1979-01-01

Selected bones from a dog that inhaled 238 PuO 2 were subjected to ultrasonic cell disruption to separate the marrow elements from bone, in order to determine the plutonium content of the two components of the skeleton

230Th-238U disequilibrium and the melting processes beneath ridge axes

International Nuclear Information System (INIS)

McKenzie, D.

1985-01-01

The activity ratio ( 230 Th/ 238 U) is calculated for a simple model of melting, for which the melt fraction in chemical and radioactive equilibrium with the solid residium remains constant as melting proceeds. The activity ratio in the melt is only significantly different from unity if the melting is slow compared with the half-life of 230 Th and if the melt fraction present at any time does not exceed a few percent. The observation that ( 230 Th/ 238 U) is about 1.25 for many ocean ridge basalts is therefore most easily explained if the melt fraction in the source region is less than 2% and if the melting occurs in a broad region more than 100 km wide beneath the ridge axis. These results are compatible with other geophysical observations. Measurements of ( 226 Ra/ 238 U) might provide useful constraints on the time required to reach chemical equilibrium between the melt and the matrix. (orig.)

24 CFR 1000.238 - What percentage of the IHBG funds can be used for administrative and planning expenses?

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false What percentage of the IHBG funds can be used for administrative and planning expenses? 1000.238 Section 1000.238 Housing and Urban... ACTIVITIES Indian Housing Plan (IHP) § 1000.238 What percentage of the IHBG funds can be used for...

Intake of 210Po, 234U and 238U radionuclides with beer in Poland

International Nuclear Information System (INIS)

Skwarzec, B.; Struminska, D.I.; Borylo, A.; Falandysz, J.

2004-01-01

238 U, 234 U and 210 Po activity concentrations were determined in beer in Poland by alpha-spectrometry with low-level activity silicon detectors. The results revealed that the mean concentrations of 238 U, 234 U and 210 Po in the analyzed beer samples were 4.63, 4.11 and 4.94 mBq x dm -3 , respectively, the highest in Tyskie (5.71 for 210 Po, 5.06 for 234 U and 6.11 for 238 U) and the lowest in Lech (2.49 for 210 Po). The effective radiation dose due to uranium and polonium ingestions by beer was calculated and were compared to the effective radiation dose from drinking water. (author)

Multilevel effect in uranium-238 and thorium-232 effective neutron capture resonance integrals

International Nuclear Information System (INIS)

Tellier, H.

1981-01-01

Until now, there has been a discrepancy between the computed and the measured values of the /sup 238/U effective capture integral. Recently, several new measurements of the resonance parameters were carried out and the use of a multilevel formalism was suggested to compute the /sup 238/U cross sections. This paper shows that the simultaneous use of recent parameters and the Reich-Moore formalism explain the discrepancy. 31 refs

The tumor necrosis factor-α-238 polymorphism and digestive system cancer risk: a meta-analysis.

Science.gov (United States)

Hui, Ming; Yan, Xiaojuan; Jiang, Ying

2016-08-01

Many studies have reported the association between tumor necrosis factor-α (TNF-α)-238 polymorphism and digestive system cancer susceptibility, but the results were inconclusive. We performed a meta-analysis to derive a more precise estimation of the relationship between TNF-α-238 G/A polymorphism and digestive system cancer risk. Pooled analysis for the TNF-α-238 G/A polymorphism contained 26 studies with a total of 4849 cases and 8567 controls. The meta-analysis observed a significant association between TNF-α-238 G/A polymorphism and digestive system cancer risk in the overall population (GA vs GG: OR 1.19, 95 % CI 1.00-1.40, P heterpgeneity = 0.016; A vs G: OR 1.19, 95 % CI 1.03-1.39, P heterpgeneity = 0.015; dominant model: OR 1.20, 95 % CI 1.02-1.41, P heterpgeneity = 0.012). In the analysis of the ethnic subgroups, however, similar results were observed only in the Asian population, but not in the Caucasian population. Therefore, this meta-analysis suggests that TNF-α-238 G/A polymorphism is associated with a significantly increased risk of digestive system cancer. Further large and well-designed studies are needed to confirm these findings.

The inflow of 234U and 238U from the River Odra drainage basin to the Baltic Sea

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Bogdan Skwarzec

2010-12-01

Full Text Available In this study the activity of uranium isotopes 234U and 238U in Odra river water samples, collected from October 2003 to July2004, was measured using alpha spectrometry. The uranium concentrations were different in each of the seasons analysed; the lowest values were recorded in summer. In all seasons, uranium concentrations were the highest in Bystrzyca river waters (from 27.81 ± 0.29Bq m-3 of 234U and 17.82 ± 0.23 Bq m-3 of 238U in spring to 194.76 ± 3.43 Bq m-3 of 234U and 134.88 ± 2.85 Bq m-3 of 238U in summer. The lowest concentrations were noted in the Mała Panew (from 1.33 ± 0.02 Bq m-3 of 234U and 1.06 ± 0.02 Bq m-3 of 238U in spring to 3.52 ± 0.05 Bq m-3 of 234U and 2.59± 0.04 Bq m-3 of 238U in autumn. The uranium radionuclides 234U and 238U in the water samples were not in radioactive equilibrium. The 234U / 238U activity ratios were the highest in Odra water samples collected at Głogów (1.84 in autumn, and the lowest in water from the Noteć (1.03 in winter and spring. The 234U / 238U activity ratio decreases along the main stream of the Odra, owing to changes in the salinity of the river's waters. Annually, 8.19 tons of uranium (126.29 G Bq of 234U and 100.80 G Bq of 238U flow into the Szczecin Lagoon with Odra river waters.

Studies on 232Th and 238U levels in marine algae collected from the coast of Niigata Prefecture

International Nuclear Information System (INIS)

Kato, Kenji; Tonouchi, Shigemasa; Maruta, Fumiyuki; Ebata, Hidekazu

2001-01-01

To evaluate the properties of algae to concentrate radioactive elements, 14 species of algae like Sargassum were collected in the Prefecture and analyzed for their 232 Th and 238 U levels with Yokogawa HP4500 ICP-MS apparatus. The places of collection included those near the water discharge of an atomic power station. Mean 232 Th and 238 U levels were found to be 120 and 260 ng/g dry wt, respectively, and Phaeophyta showed more than several times higher 238 U level than Chlorophyta and Rhodophyta. There was no clear difference in 232 Th levels. No difference between places of collection was observed in Sargassum 232 Th or 238 U level. Adsorption of 232 Th particle to and incorporation of soluble 238 U into algae body were suggested. Mean 232 Th and 238 U radioactivities were found 73 and 510 μBq/g wet wt, respectively, and the respective annual committed effective doses, 0.2 and 0.3 μSv, calculated from those values were confirmed to be enough lower than the annual public dose limit, 1 mSv. (K.H.)

Toxicidad del irinotecán en pacientes con cáncer colorrectal y variabilidad del gen UGT1A

OpenAIRE

Gayoso Rey, Mónica

2012-01-01

El cáncer colorrectal (CCR) ocupa el segundo lugar como causa de mortalidad por cáncer en la mayoría de los países desarrollados. El irinotecán es uno de los fármacos más empleados en la quimioterapia. Sin embargo, existe una variabilidad interindividual en la aparición de efectos adversos. Se han publicado diversos estudios que intentan correlacionar determinados polimorfismos genéticos con la toxicidad, mostrando discrepancias. Pocos de estos trabajos se han centrado en la población español...

Polimorfismo del gen de la banda 3 eritrocítica en grupos étnicos de Costa Rica

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M Chaves-Villalobos

2004-09-01

Full Text Available Banda 3 (AE1 es una de las proteínas más abundantes de la membrana del eritrocito humano. Ésta funciona como un intercambiador aniónico cloruro / bicarbonato y es el punto de anclaje de varias proteínas del citoesqueleto del eritrocito. Se han descrito varias mutaciones y muchas variantes polimórficas se han asociado a esferocitosis hereditaria. La identificación de un marcador genético en el extremo 5’ del gene AE1 podría asociarse a varios defectos moleculares del eritrocito. Este marcador genético es un fragmento de restricción de longitud polimórfica "RFLP" producido por la endonucleasa de restricción Pst I. Se analizaron para este polimorfismo un total de 216 individuos de siete poblaciones: una hispanomestiza (Valle Central, dos afrodescendientes (Limón y Guanacaste y cuatro amerindias (bribri, cabecar, maleku y guaymí. El alelo más frecuente en la población hispanomestiza fue el 2, mientras en los grupos afrodescendientes y amerindios se encontró el 1. No se observaron diferencias significativas con respecto al equilibrio de Hardy-Weinberg en seis de las poblaciones, sin embargo, el grupo Guaymí si presenta diferencias significativas con respecto al equilibrio de Hardy-Weinberg.Polymorphism of the erythrocyte band 3 gene (EPB3 in ethnic groups of Costa Rica. Band 3 (AE1 is one of the most abundant proteins in the membrane of the human erythrocyte. This protein works as an anionic CI - and HCO3- exchanger and it also functions as an anchor for several proteins of the erythrocyte's cytoesqueleton. Several mutations have been described and many polymorphic variants have been associated to hereditary spherocytosis. The identification of a genetic marker at position 5' of the AE1 gene could be associated to several molecular defects of the erythrocyte. This genetic marker is a restriction fragment length polymorphism (RFLP produced by restriction enzime Pst I. For this polymorphism a total of 216 individuals belonging to

Evaluation of covariance for 238U cross sections

International Nuclear Information System (INIS)

Kawano, Toshihiko; Nakamura, Masahiro; Matsuda, Nobuyuki; Kanda, Yukinori

1995-01-01

Covariances of 238 U are generated using analytic functions for representation of the cross sections. The covariances of the (n,2n) and (n,3n) reactions are derived with a spline function, while the covariances of the total and the inelastic scattering cross section are estimated with a linearized nuclear model calculation. (author)

Dissolution behaviour of 238U, 234U and 230Th deposited on filters from personal dosemeters

International Nuclear Information System (INIS)

Beckova, V.; Malatova, I.

2008-01-01

Kinetics of dissolution of 238 U, 234 U and 230 Th dust deposited on filters from personal alpha dosemeters was studied by means of a 26-d in vitro dissolution test with a serum ultra-filtrate simulant. Dosemeters had been used by miners at the uranium mine 'Dolni Rozinka' at Rozna, Czech Republic. The sampling flow-rate as declared by the producer is 4 l h -1 and the sampling period is typically 1 month. Studied filters contained 125 ± 6 mBq 238 U in equilibrium with 234 U and 230 Th; no 232 Th series nuclides were found. Half-time of rapid dissolution of 1.4 d for 238 U and 234 U and slow dissolution half-times of 173 and 116 d were found for 238 U and 234 U, respectively. No detectable dissolution of 230 Th was found. (authors)

Genes y variantes polimórficas asociadas a la enfermedad cardiovascular

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Eliana C. Portilla

2014-09-01

Full Text Available La aterosclerosis se considera como la principal causante de enfermedades cardiovasculares. Es una enfermedad multifactorial, caracterizada por procesos inflamatorios y la internalización continua de moléculas lipídicas al interior del vaso. Los estudios de genes candidato han proporcionado conocimiento acerca de la fisiopatología de esta enfermedad y han permitido la postulación de algunos polimorfismos como responsables de la susceptibilidad genética en diversas poblaciones. En particular, estos polimorfismos que modulan ciertas vías moleculares tales como el estrés oxidativo, el metabolismo lipídico y la trombogénesis se asocian con el desarrollo de las enfermedades cardiovasculares. Se han conducido varios estudios para identificar nuevas variantes asociadas con la enfermedad que han permitido el descubrimiento de nuevas vías de la enfermedad. Aunque el hallazgo de nuevos genes asociados a la enfermedad cardiovascular a través de enfoques como el escaneo global del genoma ha contribuido al entendimiento del desarrollo de esta condición, el conocimiento aún es limitado y poco concluyente. El objetivo de esta revisión es identificar los genes y las variantes polimórficas asociadas a la enfermedad cardiovascular, de acuerdo con los diferentes enfoques de análisis de asociación genética.

Análise do polimorfismo Fok1 do gene VDR em mulheres inférteis com endometriose Analysis of VDR gene polymorphism Fok1 in infertile women with endometriosis

Directory of Open Access Journals (Sweden)

Fábia Lima Vilarino

2011-02-01

Full Text Available OBJETIVO: avaliar a frequência do polimorfismo Fok1 do gene do receptor da vitamina D (VDR em mulheres inférteis com endometriose e Grupo Controle, e sua associação com a doença. MÉTODOS: estudo caso-controle que incluiu 147 mulheres inférteis com endometriose e 154 mulheres férteis sem endometriose como Controle. O polimorfismo Fok1 (rs10735810, T2C, que promove uma troca de T/C no éxon 2 do gene VDR, foi identificado por PCR-RFLP (análise de polimorfismos de fragmentos de restrição, que envolve a combinação de amplificação por PCR (reação em cadeia da polimerase e digestão com endonuclease de restrição. O teste do χ2 foi utilizado para comparar as frequências dos genótipos e alelos entre os grupos. Todos os valores de p foram bicaudais, e o nível de significância considerado foi 0,05 (αPURPOSE: to evaluate the frequency of VDR gene polymorphism Fok1 in infertile women with endometriosis and Control and its relation to the disease. METHODS: a case-control study that included 147 infertile women with endometriosis and 154 fertile women without endometriosis as Control. Fok1 polymorphism (rs10735810, T2C, which promotes a T/C exchange in exon 2 of the VDR gene, was identified by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP, that involves the combination of amplification by PCR and digestion with restriction endonuclease. The χ2 test was used to compare allele and genotype frequencies between groups. All p-values were two-tailed and a p-value < 0.05 was considered statistically significant. RESULTS: the TT, TC and CC genotype frequencies of VDR Fok1 polymorphism were 44.2%, 46.9% and 8.9% in infertile women with endometriosis and 41.6%, 50% and 8.4% in the Control Group. No significant difference was found (p=0.8, even when the patients were subdivided according to the stage of endometriosis (p=0.3 for minimal and mild endometriosis and p=0.2 for moderate and severe endometriosis

Preparation and characterization of 238Pu-ceramics for radiation damage experiments

International Nuclear Information System (INIS)

DM Strachan; RD Scheele; WC Buchmiller; JD Vienna; RL Sell; RJ Elovich

2000-01-01

As a result of treaty agreements between Russia and the US, portions of their respective plutonium and nuclear weapons stockpiles have been declared excess. In support of the US Department of Energy's 1998 decision to pursue immobilization of a portion of the remaining Pu in a titanate-based ceramic, the authors prepared nearly 200 radiation-damage test specimens of five Pu- and 238 Pu-ceramics containing 10 mass% Pu to determine the effects of irradiation from the contained Pu and U on the ceramic. The five Pu-ceramics were (1) phase-pure pyrochlore [ideally, Ca(U, Pu)Ti 2 O 7 ], (2) pyrochlore-rich baseline, (3) pyrochlore-rich baseline with impurities, (4) phase-pure zirconolite [ideally Ca(U, Pu)Ti 2 O 7 ], and (5) a zirconolite-rich baseline. These ceramics were prepared with either normal weapons-grade Pu, which is predominantly 239 Pu, or 238 Pu. The 238 Pu accelerates the radiation damage relative to the 239 Pu because of its much higher specific activity. The authors were unsuccessful in preparing phase-pure (Pu, U) brannerite, which is the third crystalline phase present in the baseline immobilization form. Since these materials will contain ∼10 mass% Pu and about 20 mass% U, radiation damage to the crystalline structure of these materials will occur overtime. As the material becomes damaged from the decay of the Pu and U, it is possible for the material to swell as both the alpha particles and recoiling atoms rupture chemical bonds within the solid. As the material changes density, cracking, perhaps in the form of microcracks, may occur. If cracking occurs in ceramic that has been placed in a repository, the calculated rate of radionuclide release if the can has corroded would increase proportionately to the increase in surface area. To investigate the effects of radiation damage on the five ceramics prepared, the authors are storing the specimens at 20, 125, and 250 C until the 238 Pu specimens become metamict and the damage saturates. They will

Wood fibre density measurement with 238 Pu radiation

International Nuclear Information System (INIS)

Barry, B.J.; Baker, D.B.

1996-01-01

The form of the curve of attenuation by wood fibre of the X radiation from 238 Pu has been determined. An exponential function containing a term second order in the areal density of the fibre described the curve accurately. The effect of scatter is negligible, even with an uncollimated radiation beam. (author). 18 refs., 1 tab., 6 figs

238U, and its decay products, in grasses from an abandoned uranium mine

Science.gov (United States)

Childs, Edgar; Maskall, John; Millward, Geoffrey

2016-04-01

Bioaccumulation of radioactive contaminants by plants is of concern particularly where the sward is an essential part of the diet of ruminants. The abandoned South Terras uranium mine, south west England, had primary deposits of uraninite (UO2) and pitchblende (U3O8), which contained up to 30% uranium. When the mine was active uranium and radium were extracted but following closure it was abandoned without remediation. Waste rock and gangue, consisting of inefficiently processed minerals, were spread around the site, including a field where ruminants are grazed. Here we report the activity concentrations of 238U, 235U 214,210Pb, and the concentrations of selected metals in the soils, roots and leaves of grasses taken from the contaminated field. Soil samples were collected at the surface, and at 30 cm depth, using an auger along a 10-point transect in the field from the foot of a waste heap. Whole, individual grass plants were removed with a spade, ensuring that their roots were intact. The soils and roots and grass leaves were freeze-dried. Activity concentrations of the radionuclides were determined by gamma spectroscopy, following 30 days incubation for development of secular equilibrium. Dried soils, roots and grasses were also digested in aqua regia and the concentrations of elements determined by ICP techniques. Maximum activity concentrations of 238U, 235U, 214Pb and 210Pb surface soils were 63,300, 4,510, 23,300 and 49,400 Bq kg-1, respectively. The mean 238U:235U ratio was 11.8 ± 1.8, an order of magnitude lower than the natural value of 138, indicating disequilibrium within the decay chain due to mineral processing. Radionuclides in the roots had 5 times lower concentration and only grass leaves in the vicinity of the waste heap had measureable values. The mean soil to root transfer factor for 238U was 36%, the mean root to leaf was 3% and overall only 0.7% of 238U was transferred from the soil to the leaves. The roots contained 0.8% iron, possibly as

Polimorfismo da hemoglobina de bubalinos (Bubalis bubalis da raça Murrah criados no Estado de São Paulo, Brasil

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A. M. F. Rosenfeld

2006-03-01

Full Text Available Os tipos de hemoglobina foram determinados em 41 amostras de sangue de bubalinos sadios da raça Murrah, criados no município de Roseira, no Estado de São Paulo, sendo cinco animais machos e 36 fêmeas. As amostras sangüíneas foram colhidas por venipunção da jugular, em tubos contendo EDTA e a determinação dos tipos de hemoglobina foi realizada pela técnica de eletroforese alcalina em acetato de celulose, utilizando-se o Tris-EDTA-Borato (pH 8,6 como solução tampão. Duas bandas de migração relativas aos alelos HbA e HbB foram observadas, identificando-se dois genótipos Hb-AA e Hb-AB e as suas freqüências na população avaliada foram: 95,1% dos bubalinos apresentaram o tipo heterozigoto Hb-AB e 4,9% o tipo homozigoto Hb-AA. O polimorfismo da hemoglobina foi observado nos bubalinos e o genótipo heterozigoto Hb-AB foi o mais freqüente.

Bone tumors induced by inhalation of 238PuO2 in dogs

International Nuclear Information System (INIS)

Park, J.F.; Lund, J.E.; Ragan, H.A.; Hackett, P.L.; Frazier, M.E.

1976-01-01

Plutonium-238, an alpha-emitting radionuclide, is used as a heat source in thermoelectric power generators such as have been employed on lunar expeditions of communications satellites and in cardiac pacemakers. It has an 86.4 year half-life and emits 5.5 MeV alpha particles. Beagle dogs were given single 10 to 30 minute exposures to 238 PuO 2 aerosols to study the long-term translocation of plutonium and biologicl effects. Dogs with a terminal body burden ranging from 7 to 260 MuCi were euthanized due to respiratory insufficiency related to plutonium-induced pneumonitis during the first 3 years after exposure. Nine of the 11 dogs euthanized during the 4 to 6 year postexposure period had osteosarcomas. The terminal plutonium body burden in the tumor-bearing dogs ranged from 0.5 to 2.6 muCi with 30 to 55 percent of the plutonium in the skeleton. Experiments are in progress to further define the dose-effect relationship of inhaled 238 PuO 2 and investigate the mechanisms of plutonium-induced neoplasia

Dissolution behaviour of 238U, 234U and 230Th deposited on filters from personal dosemeters.

Science.gov (United States)

Becková, Vera; Malátová, Irena

2008-01-01

Kinetics of dissolution of (238)U, (234)U and (230)Th dust deposited on filters from personal alpha dosemeters was studied by means of a 26-d in vitro dissolution test with a serum ultrafiltrate simulant. Dosemeters had been used by miners at the uranium mine 'Dolní Rozínka' at Rozná, Czech Republic. The sampling flow-rate as declared by the producer is 4 l h(-1) and the sampling period is typically 1 month. Studied filters contained 125 +/- 6 mBq (238)U in equilibrium with (234)U and (230)Th; no (232)Th series nuclides were found. Half-time of rapid dissolution of 1.4 d for (238)U and (234)U and slow dissolution half-times of 173 and 116 d were found for (238)U and (234)U, respectively. No detectable dissolution of (230)Th was found.

Extensión del estándar ISO 10303 AP-238 para la automatización del acceso a datos de procesos CNC

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J. Garrido

2009-01-01

Full Text Available Resumen: El nuevo estándar ISO 10303-AP238 (STEP-NC abre nuevas posibilidades para la comunicación de datos entre sistemas CAD/CAM y sistemas de fabricación CNC. Este artículo propone una extensión del modelo de información STEP-NC con nuevas estructuras de datos y nuevas funciones NC para contemplar capacidades de acceso a información en tiempo real del proceso de mecanizado, y apoyar a otras actividades avanzadas como la trazabilidad o la realización de los llamados procesos de mecanizado closed loop. Palabras Clave: Automatización, CAD/CAM, CNC, estándares, ISO, monitorizar, adquisición de datos

Uptake of plutonium-238 by plants grown under field condition as affected by one year of weathering and aging

International Nuclear Information System (INIS)

Cline, J.F.; Hinds, W.T.

1976-06-01

Less 238 Pu was concentrated in the seeds than in the vegetative parts in all plant species. Leaves contained more 238 Pu than the stem or pods, and the monocots had lower concentrations of 238 Pu in their tissues than the dicots. Irrigation of plants affected the uptake of 238 Pu, especially on the year-to-year changes in the amount of the element accumulated in the plant parts. Several more years of data must be analyzed to determine if this phenomenon is real. Soil profiles must be studied to determine what configuration changes may occur in the 238 Pu in the soil. Other investigators show that soil microbes change the chemical form of plutonium in the soil and the organic complexes that are formed are more available for plant uptake

Robertsonian chromosome polymorphism of Akodon molinae (Rodentia: Sigmodontinae: analysis of trivalents in meiotic prophase Polimorfismo cromosómico Robertsoniano de Akodon molinae (Rodentia: Sigmodontinae

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RAÚL FERNÁNDEZ-DONOSO

2001-03-01

association with the XY bivalent. In 70 % of spermatocytes studied, the XY bivalent showed complete pairing between X and Y, with SC formation along the whole length of the Y chromosome. The remaining 30 % showed partial pairing, with an SC length which varied from the common end. Based on these findings and those of previous studies, we discuss: 1.- that the obliged configuration of the trivalent, with SC formation between the short arms of 1a and 1b, helps to assure a quasi normal segregation between 1, 1a and 1b in anaphase I of Ht meiosis; and 2.- that co-existence in trivalents of chromosomes 1, 1a and 1b in Ht individuals, breaks down the structural and functional integrity of the short arms of 1a and 1b, producing an accumulative damage which would also explain the decreased viability of individuals bearing these chromosomesAkodon molinae con 2n = 42-43-44 y FN = 44 presenta un notable polimorfismo en el cromosoma 1 en poblaciones naturales y de laboratorio, los individuos 2n = 42 tienen un par 1 formado por dos cromosomas metacéntricos grandes y son denominados homocigotos simples (SH; los individuos 2n = 43, heterocigotos (Ht, presentan un cromosoma 1 y dos cromosomas subtelocéntricos de tamaño medio 1a and 1b, que son homólogos con los brazos largo y corto del 1, respectivamente; y los individuos 2n = 44 que son los doble homocigotos (DH y presentan dos pares de cromosomas subtelocéntricos 1a y 1b. Análisis de la metafases I y II meióticas han demostrado que se producen segregaciones anómalas con una alta frecuencia en los espermatocitos portadores de los cromosomas 1a and 1b. Ello alteraría a otros procesos, como la gametogénesis, la reproducción y el desarrollo, disminuyendo la viabilidad individual y poblacional de los DH. No ha habido una explicación satisfactoria para estos fenómenos. Para investigar elementos estructurales que pudiesen explicar tales alteraciones segregacionales, se estudió la sinapsis de bivalentes y trivalentes en

Radioactivity in soils and sediments in and adjacent to the Los Alamos area, 1974-1977

International Nuclear Information System (INIS)

Purtymun, W.D.; Peters, R.J.; Stoker, A.K.

1980-02-01

Soils and sediments are analyzed for gross alpha, gross beta, 238 Pu, 239 Pu, 137 Cs, 90 Sr, and total uranium as part of the continuing Environmental Monitoring Program at the Los Alamos Scientific Laboratory. This report documents the levels of radioactivity of radionuclides in soils and sediments in northern New Mexico from natural sources and worldwide fallout as well as at seven on-site soil and sediment stations which contain radioactivity contributed by the Laboratory for the period 1974 through 1977

222Rn content and 234U/238U activity ratio in groundwaters

International Nuclear Information System (INIS)

Olguin, M.T.; Segovia, N.; Ordonez, E.; Iturbe, J.L.; Bulbulian, S.; Carrillo, J.

1990-01-01

Geochemical radioanalytical studies of ground water were perfomed in the valleys of Villa de Reyes and San Luis Potosi, Mexico. The experiments were designed to measure radon and uranium content and 234 U/ 238 U activity ratio in ground water samples taken from wells in these sites and at the Nuclear Center of Salazar, Mexico. 222 Rn content varied depending on the sample source, reaching a maximum value of 235 pCi/l; uranium concentration results were less than 1 μg/l and 234 U/ 238 U activity ratios were close to equilibrium. (author) 9 refs.; 1 fig.; 1 tab

Experimental determination of the antineutrino spectrum of the fission products of {sup 238}U

Energy Technology Data Exchange (ETDEWEB)

Haag, Nils-Holger

2013-10-09

Fission of {sup 238}U contributes about 10 % to the antineutrino emission of a pressurized water reactor. In the present thesis, the beta spectrum of the fission products of {sup 238}U was determined in an experiment at the neutron source FRM II. This beta spectrum was subsequently converted into an antineutrino spectrum. This first measurement of the antineutrino spectrum supports all current and future reactor antineutrino experiments.

Solubility of 238U radionuclide from various types of soil in synthetic gastrointestinal fluids using "US in vitro" digestion method

Science.gov (United States)

Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok

2015-04-01

238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by "US P in vitro" digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 - 0.209 ppm) than gastrointestinal fluids (0.024 - 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples.

Changes in plant availability of Pu-238 during a nine year experimental period

International Nuclear Information System (INIS)

Eriksson, Aa.

1985-01-01

A short description is given of the changes observed in the plant availability of Pu-238 in eight soils during a nine year experimental period. It was found that during the first four-year period with clover as test crop, the plant uptake of Pu-238 was reduced with availability half lives ranging from 0.8 to 2.0 years. The reduction rate seemed proportional to the initial uptake levels, except for lime rich clay soils, where the reduction rate was high regardless of the uptake level. In 1980 when the test crop clover was replaced by spring wheat, the necessary soil management operations caused intenser aeration and drying in one block of the replicates. As a consequence, the Pu-uptake in that block became considerably higher than in the others. This event can be interpreted as an indirect evidence for the reversibility of that process in soil, which has caused the reduced plant availability of Pu-238

Genetic polymorphisms related to meat traits in purebred and crossbred Nelore cattle Polimorfismos genéticos relacionados às características da carne em bovinos Nelore puros e cruzados

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Rogério Abdallah Curi

2009-12-01

Full Text Available The objective of this work was to estimate the allelic and genotypic frequencies of CAST/XmnI, a calpastatin gene polymorphism, and CAPN530, a calpain 1 large subunit gene polymorphism, in different beef genetic groups (Nelore and Nelore x Bos taurus, and to investigate associations between these polymorphisms and carcass and meat traits. Three hundred animals - comprising 114 Nelore, 67 Angus x Nelore, 44 Rubia Gallega x Nelore, 41 Canchim, 19 Brangus three-way cross and 15 Braunvieh three-way cross- were genotyped by PCR-RFLP and phenotyped for rib-eye area (REA, back-fat thickness (BT, intramuscular fat (IF, shear force (SF and myofibrillar fragmentation index (MFI. The occurrence of the two alleles of the CAST/XmnI and CAPN530 single nucleotide polymorphisms (SNPs in a B. indicus breed, which permitted association studies in purebred and crossbred Nelore cattle, was first shown in the present work. No relationship was found between the CAST or CAPN1 SNPs and growth-related traits (REA or fat deposition (BT and IF, since calpastatin and µ-calpain are not physiologically involved with these traits. Moreover, the association results between genotypes and aged meat tenderness (assessed by SF and MFI showed that these markers are useless in assisted selection for purebred Nelore and their crosses with B. taurus.O presente trabalho objetivou estimar, em bovinos de corte de diferentes grupos genéticos (Nelore e Nelore x Bos taurus, as frequências alélicas e genotípicas dos polimorfismos CAST/XmnI, do gene da calpastatina, e CAPN530, do gene da calpaína, bem como avaliar a ocorrência de associações entre esses polimorfismos e características da carcaça e da carne produzida. Trezentos animais - 114 Nelore, 67 Angus x Nelore, 44 Rubia Galega x Nelore, 41 Canchim, 19 tricross Brangus e 15 tricross Braunvieh - foram genotipados por PCR-RFLP e fenotipados para área de olho de lombo (AOL, cobertura de gordura subcutânea (CGS, gordura

Estudo do polimorfismo genético no gene p53 (códon 72 em câncer colorretal Role of the genetic polymorphism of p53 (codon 72 gene in colorectal cancer

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Jacqueline Miranda de Lima

2006-03-01

Full Text Available RACIONAL: Polimorfismos genéticos são variações genéticas que podem ocorrer em seqüências codificadoras e não-codificadoras, levando a alterações qualitativas e/ou quantitativas das proteínas em questão. O p53 é o gene mais comumente alterado no câncer humano. O polimorfismo desse gene no códon 72 ocorre por substituição de uma base e tem sido associado a maior risco de câncer. OBJETIVO: Determinar a possível associação entre o polimorfismo no códon 72 (72 arginina/prolina do gene p53 e câncer colorretal. CASUÍSTICA E MÉTODOS: Foram avaliados em 100 pacientes com câncer colorretal e em 100 indivíduos sem câncer, pareados quanto ao sexo idade, o hábito de fumar, o etilismo e no grupo caso o estádio, o grau de diferenciação e a evolução da doença. O genótipo (72 arginina/prolina foi determinado por PCR, utilizando-se primers (seqüências de nucleotídeos específicos. RESULTADOS: O genótipo homozigoto arginina/arginina foi prevalente em 56% no grupo controle e em 58% no grupo caso. Não se observou diferença entre os dois grupos. No estádio IV este genótipo foi mais freqüente quando comparado ao estádio I (80% versus 14%. Não se observou diferença entre as variações do genótipo e fumo, álcool, evolução clínica ou grau de diferenciação. CONCLUSÃO: A prevalência do genótipo arginina/arginina foi a mais freqüente nos dois grupos. Não foi encontrada correlação entre maior risco de câncer e o polimorfismo no códon 72 prolina/arginina do gene p53. Apesar do pequeno número de doentes com câncer em estádio avançado (IV, estes tiveram maior prevalência do genótipo arginina/arginina.BACKGROUND: Polymorphisms are genetic variations that can occur in sequences of codons, leading to defective proteins. p53 is the most commonly gene affected in human cancer. The polymorphism of this gene occurs by a substitution of a base in codon 72 and may increase the risk of cancer. AIM: To investigate the

235U and 238U (n,xn gamma) cross-sections

International Nuclear Information System (INIS)

Bacquias, A.; Dessagne, Ph.; Kerveno, M.; Rudolf, G.; Thiry, J.C.; Borcea, C.; Negret, A.L.; Drohe, J.C.; Nankov, N.; Nyman, M.; Plompen, A.; Rouki, C.; Stanoiu, M.

2014-01-01

The (n,n') and (n,2n) are important processes in the energy domain of fission neutrons, but the cross-sections suffer from large uncertainties, not compatible with the objectives fixed for future and advanced nuclear reactors. This paper presents our experimental effort to improve 235 U and 238 U (n,xnγ) cross-section data. The experiments were performed at the GELINA facility (Belgium), which provides a pulsed (800 Hz) neutron beam covering a wide energy spectrum (from a few eV to about 20 MeV). The GRAPhEME set-up is designed for prompt gamma spectroscopy and time-of-flight measurement. The analysis methods are presented. Already published results on 235 U are shown, as well as results on 238 U. The interpretation and discussion rely on the comparison with TALYS and EMPIRE predictions. (authors)

Distribution of uranium-238 in environmental samples from a residential area impacted by mining and milling activities

International Nuclear Information System (INIS)

McConnell, M.A.; Ramanujam, V.M.S.; Alcock, N.W.; Gabehart, G.J.; Au, W.W.

1998-01-01

The northern region of Karnes County, Texas, USA, has been the site of extensive mining/milling of uranium for over 30 years. A previous study in their laboratory indicates that residents living near these facilities have increased chromosomal aberrations and a reduced DNA repair capacity. In this study, the long-lived radionuclides uranium-238 ( 238 U) and thorium-232 ( 232 Th) were measured in order to evaluate the extent of contamination from mining/milling facilities. 232 Th was quantified simultaneously and served as a reference. Soil samples were collected from the yards of previously studied households and adjacent areas near former mining and mining/milling sites at the surface and 30 cm subsurface. Additionally, samples from drinking water wells were collected from selected households. Sites located over 14 km from the study area with no known history of mining/milling served as the control. In the control area, 238 U concentrations in soil were consistent between surface (0.13--0.26 mg/kg) and subsurface samples. Near mining/milling sites, 238 U in surface soil was found to be consistently and statistically higher than corresponding subsurface samples. Near mining-only areas, 238 U in surface soil, however, was not significantly increased over subsurface soil. As expected, 238 U was much higher overall in the mining/milling and mining-only areas compared to the control sites. No trends were detected in the distribution of 232 Th. The concentration of 238 U was up to six times higher in a drinking water well near a former mining/milling operation, indicating possible leaching into the groundwater, while 232 Th concentrations were low and uniform. Furthermore, lead isotope ratio analysis indicates contamination from the interstate shipping of ore by rail to and from a mining/milling facility. These data indicate contamination of the environment by the mining/milling activities in a residential area

A reactivity hold-down strategy for soluble boron free operation by introducing Pu-238 added fuel

International Nuclear Information System (INIS)

Kim, Soon Young; Kim, Jong Kyung

2000-01-01

A new concept of Pu-238 added fuel is introduced to control the reactivity and power distribution in soluble boron free (SBF) pressurized water reactor (PWR) core. Though extensive use of burnable poison and control rods is inevitable for reactivity suppression in SBF core, it causes the core power distribution control to be so difficult that a practical SBF operation is far distant. In this work, it is confirmed that the excess reactivity can be greatly suppressed by introducing the Pu-238 added fuel. As a result of the conceptual core design of the 600 MWe SBF PWR using Pu-238 added fuel, the core reactivity is well controlled in comparison with the results obtained from the earlier 600 MWe SBF core design works. Especially, the axial power shape control is performed successfully with the aid of simple axial zoning scheme, developed in this study, by using Pu-238 enrichment zoning. The Pu-238 added fuel is also tested for 1300 MWe SBF PWR core design, in which the power distribution control can be more difficult than that of smaller plants if soluble boron control is not available. The results show that the core excess reactivity and the power distribution can be well controlled without using soluble boron even in a large-sized PWR. Hence, one of the difficult control problems arising in SBF core design can be greatly mitigated by introducing the new fuel concept. It is further expected that the Pu-238 added fuel, the simple axial zoning scheme, and the control bank operation strategy introduced in this study are directly applicable to practical SBF core design

Plutonium-238 alpha-decay damage study of the ceramic waste form

International Nuclear Information System (INIS)

Frank, S. M.; Barber, T. L.; Cummings, D.G.; DiSanto, T.; Esh, D.W.; Giglio, J. J.; Goff, K. M.; Johnson, S.G.; Kennedy, J.R.; Jue, J-F; Noy, M.; O'Holleran, T.P.; Sinkler, W.

2006-01-01

An accelerated alpha-decay damage study of a glass-bonded sodalite ceramic waste form has recently been completed. The purpose of this study was to investigate the physical and chemical durability of the waste form after significant exposure to alpha decay. This accelerated alpha-decay study was performed by doping the ceramic waste form with 238 Pu which has a much greater specific activity than 239 Pu that is normally present in the waste form. The alpha-decay dose at the end of the four year study was approximately 1 x 10 18 alpha-decays/gram of material. An equivalent time period for a similar dose of 239 Pu would require approximately 1100 years. After four years of exposure to 238 Pu alpha decay, the investigation observed little change to the physical or chemical durability of the ceramic waste form (CWF). Specifically, the 238 Pu-loaded CWF maintained it's physical integrity, namely that the density remained constant and no cracking or phase de-bonding was observed. The materials chemical durability and phase stability also did not change significantly over the duration of the study. The only significant measured change was an increase of the unit-cell lattice parameters of the plutonium oxide and sodalite phases of the material and an increase in the release of salt components and plutonium of the waste form during leaching tests, but, as mentioned, these did not lead to any overall loss of waste form durability. The principal findings from this study are: (1) 238 Pu-loaded CWF is similar in microstructure and phase composition to referenced waste form. (2) Pu was observed primarily as oxide comprised of aggregates of nano crystals with aggregates ranging in size from submicron to twenty microns in diameter. (3) Pu phases were primarily found in the intergranular glassy regions. (4) PuO phase shows expected unit cell volume expansion due to alpha decay damage of approximately 0.7%, and the sodalite phase unit cell volume has expanded slightly by 0.3% again

49 CFR Figure 2 to Subpart B of... - Example of a Multi-Level Car Complying with Window Location and Staggering Requirements-§§ 238...

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Example of a Multi-Level Car Complying with Window Location and Staggering Requirements-§§ 238.113 and 238.114 2 Figure 2 to Subpart B of Part 238.... 238, Subpt. B, Fig. 2 Figure 2 to Subpart B of Part 238—Example of a Multi-Level Car Complying with...

HARD X-RAY TAIL DISCOVERED IN THE CLOCKED BURSTER GS 1826–238

Energy Technology Data Exchange (ETDEWEB)

Rodi, J.; Jourdain, E.; Roques, J. P., E-mail: jrodi@irap.omp.eu [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France)

2016-02-01

The low-mass X-ray binary (LMXB) neutron star (NS) GS 1826–238 was discovered by Ginga in 1988 September. Due to the presence of quasi-periodicity in the type I X-ray burst rate, the source has been a frequent target of X-ray observations for almost 30 years. Though the bursts were too soft to be detected by INTEGRAL/SPI, the persistent emission from GS 1826–238 was detected over 150 keV during the ∼10 years of observations. Spectral analysis found a significant high-energy excess above a Comptonization model that is well fit by a power law, indicating an additional spectral component. Most previously reported spectra with hard tails in LMXB NS have had an electron temperature of a few keV and a hard tail dominating above ∼50 keV with an index of Γ ∼ 2–3. GS 1826–238 was found to have a markedly different spectrum with kT{sub e} ∼ 20 keV and a hard tail dominating above ∼150 keV with an index of Γ ∼ 1.8, more similar to black hole X-ray binaries. We report on our search for long-term spectral variability over the 25–370 keV energy range and on a comparison of the GS 1826–238 average spectrum to the spectra of other LMXB NSs with hard tails.

238Pu - Comments on Evaluation of Decay Data

International Nuclear Information System (INIS)

Chechev, V. P.

2013-01-01

This evaluation was done originally in March 2003, corrected in June 2004, and then updated in June 2009 with a literature cut-off by the same date. Decay Scheme: The decay scheme is based on 2007Br04. Some expected weak gamma-ray transitions were not observed directly in 238 Pu α-decay but have been adopted from decay of 234 Pa and 234 Np

Delayed fission of the 238U muonic atom

International Nuclear Information System (INIS)

Ganzorig, Dz.; Krogulski, T.; Kuznetsov, V.D.; Polikanov, S.M.; Sabirov, B.M.

1975-01-01

The time distributions of fission and muon free decay events with respect to the moment of the muon-stop event have been measured for double and triple coincidences between these three events. The triple-coincidence time distributions give an indication of the o-curence of two new effects: the delayed fission of muonic 238 U atom and conversion of muons from the fission fragments

Design improvements for gloveboxes used [in] 238PuO2 process operations

International Nuclear Information System (INIS)

George, T.G.

1997-01-01

238 PuO 2 process operations are housed in a complex of 76 gloveboxes and introductory hoods connected by means of an overhead trolley housed in a tunnel. Because a significant number of the gloveboxes used for 238 PuO 2 processing were installed before the original startup of the facility in 1978, they have been in service for nearly 20 years. During a recent heat source production campaign, numerous contamination releases in the 238 PuO 2 processing area were traced to degraded elastomer gaskets used for glovebox connections, and attachment of feed-throughs, service panels, and windows. Evaluation of the degraded gaskets revealed that a combination of radiolytic degradation related to the high specific activity of 238 Pu, and extended service at high altitude in a low (to extremely low) humidity environment had resulted in accelerated gasket aging. However, it was also apparent that gasket design was the most important factor in actual contamination release. All of the contamination releases that were traced to degraded gaskets occurred in variations of a design that used a spline to expand an elastomeric gasket into the space between a connecting flange, window, or service panel, and a glovebox opening. No contamination releases were traced to the gasket design that employed bolted clamps to compress the gasket between a connecting flange, window, or panel, and the exterior surface of a glovebox opening. As a result of these findings, the Actinide Ceramics group at LANL (NMT-9) has initiated a routine replacement and upgrade program to replace aging gloveboxes. All of the new gloveboxes will utilize the preferred gasket design, which is expected to reduce the number and frequency of contamination releases

238U, 234U and 230Th in uranium miners' lungs

International Nuclear Information System (INIS)

Singh, M.P.; Wrenn, M.E.; Archer, V.E.; Saccomanno, G.

1981-01-01

Fourteen uranium miners' lungs from Colorado plateau were collected at autopsy and the concentrations of 238 U, 234 U and 230 Th were determined by radiochemical procedures utilizing solvent extraction - alpha spectrometric techniques. The uranium and thorium isotopes are in near equilibrium with average concentrations of 238 U, 234 U and 230 Th being 89.3, 95.2 and 91.1 pCi/kg respectively. The combined average radiation dose rate to lung from these three isotopes is about 24.2 mrad/year at death excluding the unmeasured contribution from the 226 Ra and daughters. The average concentration of 230 Th is about 65 times higher than the mean concentration of 230 Th in lungs of non-miners dying at comparable ages from the same region

Distinct regions of the Phytophthora essential effector Avh238 determine its function in cell death activation and plant immunity suppression.

Science.gov (United States)

Yang, Bo; Wang, Qunqing; Jing, Maofeng; Guo, Baodian; Wu, Jiawei; Wang, Haonan; Wang, Yang; Lin, Long; Wang, Yan; Ye, Wenwu; Dong, Suomeng; Wang, Yuanchao

2017-04-01

Phytophthora pathogens secrete effectors to manipulate host innate immunity, thus facilitating infection. Among the RXLR effectors highly induced during Phytophthora sojae infection, Avh238 not only contributes to pathogen virulence but also triggers plant cell death. However, the detailed molecular basis of Avh238 functions remains largely unknown. We mapped the regions responsible for Avh238 functions in pathogen virulence and plant cell death induction using a strategy that combines investigation of natural variation and large-scale mutagenesis assays. The correlation between cellular localization and Avh238 functions was also evaluated. We found that the 79 th residue (histidine or leucine) of Avh238 determined its cell death-inducing activity, and that the 53 amino acids in its C-terminal region are responsible for promoting Phytophthora infection. Transient expression of Avh238 in Nicotiana benthamiana revealed that nuclear localization is essential for triggering cell death, while Avh238-mediated suppression of INF1-triggered cell death requires cytoplasmic localization. Our results demonstrate that a representative example of an essential Phytophthora RXLR effector can evolve to escape recognition by the host by mutating one nucleotide site, and can also retain plant immunosuppressive activity to enhance pathogen virulence in planta. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Associação entre os polimorfismos HaeIII e MspI do gene para o receptor alfa de estrogênio e densidade mamográfica em mulheres após a menopausa Association between HaeIII and MspI polymorphisms of estrogen receptor alpha gene and mammographic density in post-menopausal women

Directory of Open Access Journals (Sweden)

Eduardo Henrique de Moura Ramos

2006-10-01

Full Text Available OBJETIVO: Avaliar a presença dos polimorfismos HaeIII e MspI do gene para o receptor de estrogênio alfa, bem como fatores clínicos e suas possíveis associações com a densidade mamográfica em mulheres após a menopausa. MÉTODOS: Foram avaliadas 115 mulheres após a menopausa, não usuárias de terapia hormonal e sem lesão mamária clínica ou mamograficamente identificada. A densidade mamográfica foi determinada por três observadores independentes, tomando-se como base a classificação dos padrões mamográficos do ACR-BIRADS®, 2003 (duas avaliações subjetivas e uma computadorizada - Adobe Photoshop® 7.0. Amostras de raspado bucal foram obtidas para extração de DNA e em seguida foi realizada uma PCR-RFLP (Polymerase Chain Reation - Restriction Fragment Length Polymorphism para análise de polimorfismos presentes no íntron 1 e éxon 1 do gene do REalfa (HaeIII e MspI. RESULTADOS: O polimorfismo HaeIII foi encontrado em 43 (37,4% das 115 mulheres, ao passo que o MspI estava presente em 96 (83,5% das mesmas. Houve alto grau de concordância entre os três observadores na determinação da densidade mamográfica. Trinta e quatro (29,6% mulheres tinham mamas densas, e 81 (70,4%, mamas lipossubstituídas. CONCLUSÃO: Não houve associação entre o polimorfismo HaeIII do gene para o receptor de estrogênio alfa e densidade mamográfica (Fisher = 0,712. Houve associação próxima à significância estatística entre o polimorfismo MspI e densidade (Fisher = 0,098. Idade, paridade e índice de massa corporal mostraram-se associados com densidade mamográfica.PURPOSE: To assess the presence of estrogen receptor gene polymorphisms HaeIII and MspI as well as clinical factors, and their possible associations with high mammographic density in post-menopausal women. METHODS: One hundred and fifteen post-menopausal women, not in use of hormonal therapy and without clinical or mammographic lesions were evaluated. Three independent observers

Solubility of 238U radionuclide from various types of soil in synthetic gastrointestinal fluids using “US in vitro” digestion method

International Nuclear Information System (INIS)

Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok

2015-01-01

238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by “US P in vitro” digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 – 0.209 ppm) than gastrointestinal fluids (0.024 – 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples

Estructura genética del copépodo Acartia lilljeborgii en la costa del estado de Yucatán, México

OpenAIRE

Jorge Tello-Cetina; Lucia Gómez-Victoria; Roberto Zamora-Bustillos; Gerardo Rivera-Muñoz; Sara Solis-Pereira; Herbert Loria-Sunza

2013-01-01

Se determinó la estructura genética poblacional y sus implicancias dentro de la cadena trófica del copépodo Acartia lilljeborgii en la costa de Yucatán, mediante el uso de isoenzimas y su posterior determinación por electroforesis. Nueve sistemas se expresaron con un máximo de 30 loci. El polimorfismo y heterocigosis de las poblaciones estudiadas, al ser comparados con otras especies de copépodos, resultaron ser bajos y de los cuatro loci que presentaron variación, solo los loci EST2 y PGM1 s...

Lack of association between VNTR polymorphism of dopamine transporter gene (SLC6A3 and schizophrenia in a Brazilian sample Ausência de associação entre o polimorfismo VNTR do gene do transportador de dopamina (SLC6A3 e esquizofrenia em uma população brasileira

Directory of Open Access Journals (Sweden)

Quirino Cordeiro

2004-12-01

Full Text Available A role of dopaminergic dysfunction has been postulated in the aetiology of schizophrenia. We hypothesized that variations in the dopamine transporter gene (SLC6A3 may be associated with schizophrenia. We conducted case-control and family based analysis on the polymorphic SLC6A3 variable number tandem repeat (VNTR in a sample of 220 schizophrenic patients, 226 gender and ethnic matched controls, and 49 additional case-parent trios. No differences were found in allelic or genotypic distributions between cases and controls and no significant transmission distortions from heterozygous parents to schizophrenic offspring were detected. Thus, our results do not support an association of the SLC6A3 VNTR with schizophrenia in our sample.Genes do sistema dopaminérgico são de escolha para a pesquisa de susceptibilidade para a esquizofrenia. Desse modo, possível contribuição do polimorfismo do gene do transportador de dopamina (SLC6A3 no aumento da vulnerabilidade para a esquizofrenia foi investigada no presente estudo. Analisou-se a distribuição do sítio polimórfico do gene do transportador de dopamina (VNTR em uma população de 220 pacientes com esquizofrenia (critério diagnóstico: DSM-IV e comparou-se com a distribuição em uma população controle de 226 indivíduos pareados para sexo e etnia. Nenhuma diferença foi observada na distribuição dos alelos entre casos e controles. O mesmo polimorfismo também foi investigado em uma segunda amostra composta por 49 trios (pais e probando. O resultado também foi negativo. Tais dados não dão suporte para a participação do polimorfismo do gene do transportador de dopamina no aumento de susceptibilidade para esquizofrenia na amostra estudada.

Precise measurement and calculation of 238U neutron transmissions

International Nuclear Information System (INIS)

Olsen, D.K.; de Saussure, G.; Silver, E.G.; Perez, R.B.

1975-01-01

The total neutron cross section of 238 U has been measured above 0.5 eV in precise transmission experiments and results are compared with ENDF/B-IV. Emphasis has been on measuring transmissions through thick samples in order to obtain accurate total cross sections in the potential-resonance interference regions between resonances. 4 figures, 1 table

Beta decay heat following U-235, U-238 and Pu-239 neutron fission

Science.gov (United States)

Li, Shengjie

1997-09-01

This is an experimental study of beta-particle decay heat from 235U, 239Pu and 238U aggregate fission products over delay times 0.4-40,000 seconds. The experimental results below 2s for 235U and 239Pu, and below 20s for 238U, are the first such results reported. The experiments were conducted at the UMASS Lowell 5.5-MV Van de Graaff accelerator and 1-MW swimming-pool research reactor. Thermalized neutrons from the 7Li(p,n)7Be reaction induced fission in 238U and 239Pu, and fast neutrons produced in the reactor initiated fission in 238U. A helium-jet/tape-transport system rapidly transferred fission fragments from a fission chamber to a low background counting area. Delay times after fission were selected by varying the tape speed or the position of the spray point relative to the beta spectrometer that employed a thin-scintillator-disk gating technique to separate beta-particles from accompanying gamma-rays. Beta and gamma sources were both used in energy calibration. Based on low-energy(energies 0-10 MeV. Measured beta spectra were unfolded for their energy distributions by the program FERD, and then compared to other measurements and summation calculations based on ENDF/B-VI fission-product data performed on the LANL Cray computer. Measurements of the beta activity as a function of decay time furnished a relative normalization. Results for the beta decay heat are presented and compared with other experimental data and the summation calculations.

40 CFR 23.8 - Timing of Administrator's action under Uranium Mill Tailings Radiation Control Act of 1978.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Timing of Administrator's action under Uranium Mill Tailings Radiation Control Act of 1978. 23.8 Section 23.8 Protection of Environment... Administrator's action under Uranium Mill Tailings Radiation Control Act of 1978. Unless the Administrator...

238U, 234U and 230Th in uranium miners' lungs

International Nuclear Information System (INIS)

Singh, N.P.; Wrenn, M.E.; Bennett, D.B.; Archer, V.; Saccomanno, G.

1982-01-01

Fourteen uranium miners' lungs from the Colorado Plateau were collected at autopsy and the concentrations of 238 U, 234 U and 230 Th were determined by radiochemical procedures utilizing solvent extraction and alpha spectrometric techniques. The uranium and thorium isotopes are in near equilibrium with average concentrations of 238 U, 234 U and 230 Th being 89.3, 95.2, and 91.1 pCi/kg respectively. The combined average radiation dose rate to lung from these three isotopes is about 24.1 mrad/year at death excluding the unmeasured contribution from the 226 Ra and daughters. The average concentration of 230 Th is about 65 times higher than the mean concentration of 230 Th in lungs of non-miners from the same region dying at comparable ages

Behavior of plutonium-238 solutions in the soil and hydrology system at Mound Laboratory

International Nuclear Information System (INIS)

Rodgers, D.R.

1976-01-01

Because plutonium is a potentially hazardous material, extensive precautions have been exercised since Pu operations began at Mound Laboratory to carefully maintain strict control of the Pu and to prevent significant amounts from entering the environment. These precautions include elaborate facility and equipment design criteria, scientific expertise, experience, personnel training, management and operational control systems, and environmental monitoring. In spite of these precautions, in early 1974, core samples from area waterways collected and analyzed showed that 238 Pu concentrations in the sediment of certain waterways adjacent to the site were above the baseline levels expected ( 238 Pu deposits presented no immediate hazard to the general population in the area as indicated by the air and water concentrations which were well within accepted Radioactivity Concentration Guides (RCG) for 238 Pu. Data are presented from an investigation of the extent of the contamination, the source of Pu, how it was transported and deposited in waterways, and potential hazards of these deposits to the general public

Fabrication of gamma sources using the neutron-gamma reactions of 238Pu13C

International Nuclear Information System (INIS)

Solinhac, I.; Maillard, C.; Donnet, L.

2004-01-01

A production campaign for 238 Pu 13 C sources with gamma fluence ranging from 2500 to 4500 gamma/s/4π at 6.13 MeV was carried out in 2002 in Atalante. An experimental study was undertaken to prepare the 238 PuC mixture, which is the most delicate step. This procedure is described together with the other steps in the source fabrication process: purification of a plutonium oxide batch, preparation of a nitric solution of 238 Pu, measurement of the gamma fluence of the PuC mixture before and after insertion into each of the two stainless steel capsules that constitute a PuN 2 O package, welding of the second envelope followed by leak testing, final measurement of the gamma fluence of the sealed source. This PuC sources fabrication procedure is effective: all the sources include the required gamma activity with an uncertainty on the gamma fluence of less than 10%. (authors)

Measurement and resonance analysis of neutron transmissions through four samples of 238U

International Nuclear Information System (INIS)

Olsen, D.K.; de Saussure, G.; Perez, R.B.; Difilippo, F.C.; Ingle, R.W.

1977-01-01

Accurate total and partial cross sections for 238 U are important for nuclear reactor design. In the resolved resonance region, energies below 4.0 keV, these cross sections are described in terms of individual resonance parameters of which the neutron widths in the 1.5 to 4.0 keV region from various workers appear discrepant. In order to determine these widths, (0.880 to 100.0 keV) neutron transmissions through 0.076, 0.254, 1.080, and 3.620 cm thick enriched 238 U samples were measured, and (0.880 to 100.0 keV) range transmissions were analyzed

Acceptable knowledge summary report for combustible/noncombustible, metallic, and HEPA filter waste resulting from 238Pu fabrication activities

International Nuclear Information System (INIS)

Rogers, P.S.Z.; Foxx, C.L.

1998-01-01

All transuranic (TRU) waste must be sufficiently characterized and certified before it is shipped to the Waste Isolation Pilot Plant (WIPP). The US Environmental Protection Agency (EPA) allows use of acceptable knowledge (AK) for waste characterization. EPA uses the term AK in its guidance document and defines AK and provides guidelines on how acceptable knowledge should be obtained and documented. This AK package has been prepared in accordance with Acceptable Knowledge Documentation (TWCP-QP-1.1-021,R.2). This report covers acceptable knowledge information for five waste streams generated at TA-55 during operations to fabricate various heat sources using feedstock 238 Pu supplied by the Savannah River Site (SRS). The 238 Pu feedstock itself does not contain quantities of RCRA-regulated constituents above regulatory threshold limits, as known from process knowledge at SRS and as confirmed by chemical analysis. No RCRA-regulated chemicals were used during 238 Pu fabrication activities at TA-55, and all 238 Pu activities were physically separated from other plutonium processing activities. Most of the waste generated from the 238 Pu fabrication activities is thus nonmixed waste, including waste streams TA-55-43, 45, and 47. The exceptions are waste streams TA-55-44, which contains discarded lead-lined rubber gloves used in the gloveboxes that contained the 238 Pu material, and TA-55-46, which may contain pieces of discarded lead. These waste streams have been denoted as mixed because of the presence of the lead-containing material

Rol de la farmacogenómica en el régimen de tratamiento de tuberculosis

Directory of Open Access Journals (Sweden)

Heinner Guio

Full Text Available La tuberculosis es un problema de salud Pública a nivel mundial con un tercio de la población infectada por el bacilo Mycobacterium tuberculosis. El tratamiento de primera línea incluye a las drogas isoniazida (INH y rifampicina (RIF metabolizadas en el hígado. La metabolización de drogas está directamente relacionada con la variación genética de NAT2 y CYP2E1 (asociados a metabolismo de INH y AADAC (asociados a metabolismo de RIF, y los efectos pueden producir que un individuo sea metabolizador rápido, intermedio o lento. Los polimorfismos en genes de personas con tratamiento estándar de tuberculosis pueden ocasionar efectos en el metabolismo de drogas con consecuencias de hepatoxicidad e, incluso, posible drogorresistencia. Algunos países han empezado ensayos clínicos enfocados en la personalización del tratamiento a tuberculosis para reducir las consecuencias en pacientes en tratamiento. En países como el Perú, donde se registran altos índices de tuberculosis y, por consiguiente, más población en tratamiento, la farmacogenómica de individuos se convierte en una herramienta crucial para un óptimo tratamiento. La presente revisión destaca la importancia de tener estudios en farmacogenómica e identificar los polimorfismos asociados al metabolismo de las drogas antituberculosas en nuestra población peruana

Studies on {sup 232}Th and {sup 238}U levels in marine algae collected from the coast of Niigata Prefecture

Energy Technology Data Exchange (ETDEWEB)

Kato, Kenji; Tonouchi, Shigemasa; Maruta, Fumiyuki; Ebata, Hidekazu [Niigata Prefectural Inst. of Public Health and Environmental Sciences (Japan)

2001-12-01

To evaluate the properties of algae to concentrate radioactive elements, 14 species of algae like Sargassum were collected in the Prefecture and analyzed for their {sup 232}Th and {sup 238}U levels with Yokogawa HP4500 ICP-MS apparatus. The places of collection included those near the water discharge of an atomic power station. Mean {sup 232}Th and {sup 238}U levels were found to be 120 and 260 ng/g dry wt, respectively, and Phaeophyta showed more than several times higher {sup 238}U level than Chlorophyta and Rhodophyta. There was no clear difference in {sup 232}Th levels. No difference between places of collection was observed in Sargassum {sup 232}Th or {sup 238}U level. Adsorption of {sup 232}Th particle to and incorporation of soluble {sup 238}U into algae body were suggested. Mean {sup 232}Th and {sup 238}U radioactivities were found 73 and 510 {mu}Bq/g wet wt, respectively, and the respective annual committed effective doses, 0.2 and 0.3 {mu}Sv, calculated from those values were confirmed to be enough lower than the annual public dose limit, 1 mSv. (K.H.)

An attempt to explain the uranium 238 resonance integral discrepancy

International Nuclear Information System (INIS)

Tellier, H.; Grandotto, M.

1978-01-01

Studies on uranium 238 resonance integral discrepancy were carried out for light water reactor physics. It was shown that using recently published resonance parameters and substituting a multilevel formalism to the usual Breit and Wigner formula reduced the well known discrepancy between two values of the uranium 238 effective resonance integral: the value calculated with the nuclear data and the one deduced from critical experiments. Since the cross section computed with these assumptions agrees quite well with the Oak-Ridge transmission data, it was used to obtain the self-shielding effect and the capture rate in light water lattices. The multiplication factor calculated with this method is found very close to the experimental value. Preliminary results for a set of benchmarks relative to several types of thermal neutron reactors lead to very low discrepancies. The reactivity loss is only 130 x 10 -5 instead of 650 x 10 -5 in the case of the usual libraries and the single level formula

Detection limit of 238U by gamma spectrometry

International Nuclear Information System (INIS)

Tartaglione, A.; Blostein, J.; Mayer, R

2004-01-01

The detection limit of 238 U was determined by gamma spectra measurements of a depleted uranium sample using four NaI(Tl) scintillators in a compact arrangement.The sample was shielded with 5 and 10 cm of lead.Two different methods for data processing were used and compared.It was established that an appropriate array of 40 detectors could establish the presence of 220 g of this material in only 5 minutes [es

Determination of plutonium-238 in plutonium by alpha spectrometry

International Nuclear Information System (INIS)

Aggarwal, S.K.; Jain, H.C.; Mathews, C.K.; Ramaniah, M.V.

1975-01-01

A method is presented for the determination of 238 Pu in plutonium samples by alpha spectrometry. Various factors attributing towards the energy degradation, a problem usually encountered in alpha spectrometry, are discussed. A computer programme is given for the evaluation of peak areas when the alpha spectrum is degraded. The results are compared with those obtained by mass spectrometry. (author)

Solubility of {sup 238}U radionuclide from various types of soil in synthetic gastrointestinal fluids using “US in vitro” digestion method

Energy Technology Data Exchange (ETDEWEB)

Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok, E-mail: khoo@ukm.edu.my [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

2015-04-29

238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by “US P in vitro” digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 – 0.209 ppm) than gastrointestinal fluids (0.024 – 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples.

An attempt to explain the uranium 238 effective capture integral discrepancy

International Nuclear Information System (INIS)

Tellier, Henry; Grandotto-Biettoli, Marc; Vanuxeem, Jacqueline

1979-02-01

Up to now, there was a discrepancy between the computed value and the measured value of the uranium 238 effective capture integral. The former has been always greater than the latter. For this reason, the reactor physicists have used an adjustment of the computed value. Nowadays the accuracy of the cross sections knowledge is increased and the reactors computation codes are almost exact. Such an adjustment is no more justified. Recently several new measurements of the resonance parameters were carried out and the use of a multilevel formalism was suggested to compute the uranium 238 cross sections. It is shown in this work that the simultaneous use of recent parameters and Reich and Moore formalism explain the discrepancy. For the thermal neutron reactors, two thirds of this discrepancy are explained by the neutron data and the last third by the multilevel formalism [fr

Swift observations of GS 1826-238

Science.gov (United States)

Ji, L.; Santangelo, A.; Zhang, S.; Ducci, L.; Suleimanov, V.

2018-02-01

GS 1826-238 is a well-studied low-mass X-ray binary neutron star. This source was in a persistent hard state since its discovery in 1988 and until 2014 June. After that, the source exhibited several softer periods of enhanced intensity in the energy range 2-20 keV. We studied the long-term light curves of MAXI (Monitor of All Sky X-ray Image) and Swift/BAT, and found clearly two branches in the MAXI-BAT and hardness-intensity diagrams, which correspond to the persistent state and softer periods, respectively. We analysed 21 Swift/XRT observations, of which four were located in the persistent state while the others were in softer periods or in a state between them. The XRT spectra could be generally fitted by using an absorbed Comptonization model with no other components required. We found a peculiar relationship between the luminosity and the hardness in the energy range of 0.6-10 keV: when the luminosity is larger (smaller) than 4 per cent-6 per cent Ledd, the hardness is anti-correlated (correlated) with luminosity. We also estimated the variability for each observation by using the fractional rms in the 0.1-10 Hz range. We found that the observations in the persistent state had a large fractional rms of ˜25 per cent, similar to other low-mass X-ray binaries. However, the variability is mainly found in the range of 5 per cent-20 per cent during softer periods. We suggest that GS 1826-238 did not evolve into the soft state of atoll sources, and all the observed XRT observations during the softer periods resemble a peculiar intermediate state of atoll sources.

Effect of carbides on erosion resistance of 23-8-N steel

Indian Academy of Sciences (India)

8-N nitronic steel, carbides present in the form of bands are observed to accelerate the erosion rate. Coarse ... lar carbides, precipitating at random boundaries, were more likely to ... 23-8-N nitronic steel is basically austenitic stainless steel.

Management of nuclear materials in an R ampersand D environment at the Los Alamos National Laboratory

International Nuclear Information System (INIS)

Behrens, R.G.; Roth, S.B.; Jones, S.R.

1991-01-01

Los Alamos National Laboratory is a multidisciplinary R ampersand D organization and, as such, its nuclear materials inventory is diverse. Accordingly, major inventories of isotopes such as Pu-238, Pu-239, Pu-242, U-235, Th, tritium, and deuterium, and lesser amounts of isotopes of Am, Cm, Np and exotic isotopes such as berkelium must be managed in accordance with Department of Energy Orders and Laboratory policies. Los Alamos also acts as a national resource for many one-of-a-kind materials which are supplied to universities, industry, and other government agencies within the US and throughout the world. Management of these materials requires effective interaction and communication with many nuclear materials custodians residing in over forty technical groups as well as effective interaction with numerous outside organizations. This paper discusses the role, philosophy, and organizational structure of Nuclear Materials Management at Los Alamos and also briefly presents results of two special nuclear materials management projects: 1- Revision of Item Description Codes for use in the Los Alamos nuclear material data base and 2- The recommendation of new economic discard limits for Pu-239. 2 refs., 1 fig

Asociación de polimorfismos en DNA mitocondrial y diabetes mellitus tipo 2 Descriptive study of the current status of the pediatric practice in Antioquia

Directory of Open Access Journals (Sweden)

Gabriel Bedoya Berrío

2003-01-01

Full Text Available

La Diabetes mellitus tipo 2 (DM2 es un trastorno metabólico
caracterizado por una marcada resistencia a la insulina en los tejidos blanco; la prevalencia de DM2 presenta grandes diferencias en poblaciones humanas; es muy alta en aquéllas originadas por migraciones que han cambiado su etilo de vida; alcanza niveles hasta del 30% en poblaciones de americanos nativos como los Pima, que presentan la incidencia más alta en el ámbito mundial (1, en contraste con la población británica que sólo alcanza el 2%. Para explicar este fenómeno James Neel propuso la hipótesis del ";;;;genotipo económico";;;; en la cual sugiere que el genotipo que confiere susceptibilidad a DM2 acompañada de obesidad, aparece en los humanos como un genotipo con ventajas evolutivas para períodos de escasez de alimentos, pero es desventajoso cuando la población entra a períodos de abundancia.

Con el fin de probar el efecto que el DNA mitocondrial (mtDNA, puede tener en el genotipo económico nos propusimos evaluar la asociación de polimorfismos en mtDNA y DM2, comparando estadísticamente las frecuencias alélicas y haplotípicas de locipolimórficos en el mtDNA entre un grupo de casos y un grupo control para DM2 en población antioqueña.

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

Directory of Open Access Journals (Sweden)

Walter E. Rodríguez Romero

1998-01-01

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

Performance evaluation of indigenous thermal ionization mass spectrometer for determination of 235U/238U atom ratios

International Nuclear Information System (INIS)

Alamelu, D.; Parab, A.R.; Sasi Bhushan, K.; Shah, Raju V.; Jagdish Kumar, S.; Rao, Radhika M.; Aggarwal, S.K.; Bhatia, R.K.; Yadav, V.K.; Sharma, Madhavi P.; Tulsyan, Puneet; Chavda, Pradip; Sriniwasan, P.

2014-07-01

A magnetic sector based Thermal Ionization Mass Spectrometer (TIMS) designed and developed at Technical Physics Division, B.A.R.C., was evaluated for its performance for the determination of 235 U/ 238 U atom ratios in uranium samples. This consisted of evaluating the precision and accuracy on the 235 U/ 238 U atom ratios in various isotopic reference materials as well as indigenously generated uranium samples. The results obtained by the indigenous TIMS were also compared with those obtained using a commercially available TIMS system. The internal and external precision were found to be around 0.1% for determining 235 U/ 238 U atom ratios close to those of natural uranium ( i.e. 0.00730). (author)

Biokinetics aand dosimetry of inhaled 238PuO2 in the beagle dog: An update

International Nuclear Information System (INIS)

Guilmette, R.A.; Griffith, W.C.; Diel, J.H.

1994-01-01

The temporal and spatial distributions of 238 Pu have been measured during the course of a dose-response study of the biological effects of inhaled 238 PuO 2 in Beagle dogs. These measurements were done on the dose-response study animals, as well as a separate group of dogs exposed to similar aerosols and killed serially out to 4 y after exposure. The data from this latter group provided the basis for the development of a biokinetic/dosimetric model for 238 PuO 2 in dogs. Since the publication of this model, several important findings have been made that affected the dosimetric evaluations. The first involved the discovery of significant quantities of natural uranium (U) in the feces samples. The U was measured with the plutonium (Pu), which inflated the values for purported Pu in feces. The second finding involved the addition of Pu biokinetics data from the dose-response dogs, which increased the period of observation from 4 y to 15 y; these later data were not consistent with the earlier model predictions. The purpose of this investigation was (1) to remove the analytical bias in the 238 Pu radiochemical data due to the U and (2) to modify the original model of Mewhinney and Diel, taking into account all data from both studies

Neutron induced fission cross section ratios for 232Th, 235,238U, 237Np and 239Pu from 1 to 400 MeV

International Nuclear Information System (INIS)

Lisowski, P.W.; Ullmann, J.L.; Balestrini, S.J.; Carlson, A.D.; Wasson, O.A.; Hill, N.W.

1988-01-01

Time-of-flight measurements of neutron induced fission cross section ratios for 232 Th, 235,238 U, 237 Np, and 239 Pu, were performed using the WNR high intensity spallation neutron source located at Los Alamos National Laboratory. A multiple-plate gas ionization chamber located at a 20-m flight path was used to simultaneously measure the fission rate for all samples over the energy range from 1 to 400 MeV. Because the measurements were made with nearly identical neutron fluxes, we were able to cancel many systematic uncertainties present in previous measurements. This allows us to resolve discrepancies among different data sets. In addition, these are the first neutron-induced fission cross section values for most of the nuclei at energies above 30 MeV. (author)

Una variante del gen CAPN10 y los factores ambientales muestran asociación con el exceso de peso en jóvenes colombianos

Directory of Open Access Journals (Sweden)

Ana C. Orozco

2014-12-01

Full Text Available Introducción. La obesidad resulta de la interacción entre factores de riesgo genéticos y ambientales. Objetivo. Evaluar el efecto de tres variantes genéticas y factores ambientales en el exceso de peso en jóvenes de 10 a 18 años de Medellín, Colombia. Materiales y métodos. Se hizo un estudio transversal en 424 jóvenes divididos en tres grupos: 100 obesos, 112 jóvenes con sobrepeso, y, pareados con ellos, 212 jóvenes con peso adecuado, que conformaron el grupo de control. Se evaluó la asociación entre tres polimorfismos genéticos (UCP3-rs1800849, FTO-rs17817449 y CAPN10-rs3842570 y el exceso de peso, así como su interacción con antecedentes familiares de enfermedad, el tiempo dedicado a ver televisión y a jugar videojuegos y el consumo de alimentos. Resultados. Los antecedentes familiares de obesidad, la dedicación de más de dos horas al día a ver televisión y jugar videojuegos, la falta de lactancia materna, el bajo consumo de cereales, legumbres, frutas y verduras y el gran consumo de comidas rápidas fueron más frecuentes entre los obesos que en los controles. Se observó una asociación significativa entre el genotipo I/I (SNP19 del CAPN10 y el exceso de peso, incluso en los jóvenes que llevaban una vida activa. Además, se encontró una asociación significativa entre los genotipos C/C del UCP3 y G/G y T/T del FTO y el exceso de peso, pero solo en los jóvenes sedentarios. Conclusiones. En esta población, la alimentación inadecuada y el sedentarismo aumentaron el riesgo de exceso de peso. El genotipo I/I de SNP19 del CAPN10 se asoció significativamente con el exceso de peso. Algunas variantes del FTO y el UCP3 mostraron tener efecto solo en jóvenes sedentarios.

Precise 238U(n,2n)237U reaction cross-section measurements using the activation facility at TUNL

Science.gov (United States)

Krishichayan, Fnu; Bhike, M.; Tornow, W.

2014-09-01

Accurate neutron-induced 238U(n,2n)237U reaction data are required for many practical applications, especially in the field of nuclear energy, including advanced heavy water reactors, where 238U is used as the breeding material to regenerate the fissile material 239Pu. Precise (n,2n) cross-section measurements of 238U are underway at TUNL with mono-energetic neutrons in the 8.0 to 14.0 MeV energy range in steps of 0.25 MeV using the activation technique. After activation of the 0.5 inch diameter and 442 mg 238U foil, the activity of the 208 keV characteristic γ-line is tracked for 6 weeks with a high efficient HPGe clover detector to determine the initial activity needed for the cross-section determination. Results of the cross-section measurements, determined relative to 27Al and 197Au neutron activation monitor foils, and the comparison with theoretical models will be presented during the meeting.

49 CFR 238.105 - Train electronic hardware and software safety.

Science.gov (United States)

2010-10-01

... and software system safety as part of the pre-revenue service testing of the equipment. (d)(1... safely by initiating a full service brake application in the event of a hardware or software failure that... 49 Transportation 4 2010-10-01 2010-10-01 false Train electronic hardware and software safety. 238...

Research on the reliability of measurement of natural radioactive nuclide concentration of U-238

Energy Technology Data Exchange (ETDEWEB)

Cha, Seok Ki; Kim, Gee Hyun [Dept. of Nuclear engineering, Univ. of SeJong, Seoul (Korea, Republic of); Joo, Sun Dong; Lee, Hoon [KoFONS, Seongnam (Korea, Republic of)

2016-12-15

Naturally occurred radioactive materials (NORM) can be found all around us and people are exposed to this no matter what they do or where they live. In this study, two indirect measurement methods of NORM U-238 has been reviewed; one that has used HPGe on the basis of the maintenance, and the other is disequilibrium theory of radioactive equilibrium relationships of mother and daughter nuclide at Decay-chain of NORM U-238. For this review, complicated pre-processing process (Breaking->Fusion->Chromatography->Electron deposit) has been used , and then carried out a comparative research with direct measurement method that makes use of and measures Alpha spectrometer. Through the experiment as above, we could infer the daughter nuclide whose radioactive equilibrium has been maintained with U-238. Therefore, we could find out that the daughter nuclide suitable to be applied to Gamma indirect measurement method was Th-234. Due to Pearson Correlation statistics, we could find out the reliability of the result value that has been analyzed by using Th-234.

Phosphate fertilizer influence on 238 U content in vegetables

International Nuclear Information System (INIS)

Lauria D, C.; Rodrigues S, J.I.; Ribeiro, F.C.A.

2006-01-01

Uranium is a naturally radioactive element, which is usually found in soils, superficial and ground water, vegetables and animals. After ingestion by human beings, most is excreted in few days by feces and urine, without reaching the bloodstream. However, a small part circulates through the body, being accumulated in the soft tissues, as kidneys. A minor fraction can remain in bones per some years, being able through the radioactive decay to irradiate adjacent tissues. Phosphate fertilizers used in conventional crop management can present variable amounts of uranium. In accordance with origin and use, the fertilizer can raise the content of this element in vegetables, and consequently to increase the human exposure for radiation due the consumption of vegetables. It is estimated that the use of phosphate fertilizer has at least doubled the prolonged exposure of humans from ingestion of food. This work aims to evaluate the contribution of organic and chemical fertilizer on the concentration of 238 U in vegetable samples. An experiment with black beans (a very important vegetable for Brazilian people) was conducted in a field which soil has never been fertilized with any sort of fertilizer, located near to the Rio de Janeiro city. On the organic management, bovine manure was used, while on conventional management urea, potassium chloride and superphosphate were used. Simultaneously, black bean samples from not fertilized management were collected. In addition, lettuce and carrot samples from organic and conventional managements were collected in Nova Friburgo farms (the most important vegetable supplier of Rio de Janeiro city market). The analyses of 238 U have been carried out by conventional fluorimetric method. The geometric mean of 238 U concentrations in the carrot and lettuce samples from conventional management were similar with those from organic management, while for beans the conventional samples had higher values than those ones found in organic management

Application of the grey system theory for forecasting the content of 238U in soil near a uranium mine exhaust outlet

International Nuclear Information System (INIS)

Ye Yongjun; Ding Dexin; Li Xiangyang; Zhou Xinghuo; Liu Dong

2008-01-01

In order to forecast the content of 238 U in soil near a uranium mine exhaust outlet, a general GM(1,1) forecasting model was established based on grey system theory, analyzing association degree and residual error distinction. According to the measuring datum of the content of 238 U in soil near a uranium mine exhaust outlet from 2001 to 2006, used the model to forecast the content of 238 U in soil, The results show that the forecasting value agrees with the measuring results and the forecasting precision is higher; at the same time the content of 238 U in soil in 2007 is also forecasted based on the model, the relative error was 4.8%; which shows the GM(1,1) forecasting model has higher practical value, and is a effective method for forecasting the content of 238 U in soil near a uranium mine exhaust outlet. (authors)

(e,e'f) coincidence experiments for fission decay of giant resonances in 235,238U

International Nuclear Information System (INIS)

Weber, T.; Heil, R.D.; Kneissl, U.; Pecho, W.; Wilke, W.; Emrich, H.J.; Kihm, T.; Knoepfle, K.T.

1988-01-01

Extending previous work on 238 U, 235 U(e,e'f) coincidence data were taken at 4 momentum transfers yielding both E1, E2/E0 and E3 form factors and the respective multipole strength distributions in the giant resonance region of 238 U (4 x x /Γ a is obtained as a function of excitation energy for separated multipoles. The giant E2 resonance exhibits an increased symmetric fission contribution compared to E1 and E3 resonances. (orig.)

Caracterización de accesiones de papaya (Carica papaya L. a través de marcadores AFLP en Cuba

Directory of Open Access Journals (Sweden)

Maruchi Alonso Esquivel

2009-07-01

Full Text Available Los marcadores moleculares son herramientas valiosas en los estudios genéticos en plantas, y están siendo empleados exitosamente en programas de mejoramiento principalmente en la elección de progenitores y en la selección. El polimorfismo observado mediante la técnica molecular AFLP (Amplified Fragment Length Polymorphism ha sido de utilidad para estudios de diversidad genética en frutales. En el presente trabajo se realizó la caracterización molecular de 12 accesiones de papaya (Carica papaya L. del banco de germoplasma del Instituto de Investigaciones en Fruticultura Tropical (IIFT, empleando la técnica AFLP. Se evaluaron seis combinaciones de iniciadores para la amplificación selectiva, las cuales amplificaron un total de 431 bandas con 73,3% de polimorfismo. El número total de patrones de bandas identificados fue igual en todas las combinaciones utilizadas, con un porcentaje de identificación alto, lo que sugiere que dichas combinaciones pudieran ser empleadas para estudios de variabilidad genética en papaya. En general, los resultados presentados demuestran que existe diversidad genética entre las accesiones evaluadas, lo cual constituye un reflejo del origen que presentan los genotipos analizados a partir de la introducción de materiales foráneos y la polinización abierta de un grupo de materiales selectos. Por tanto, se recomienda retomar la prospección y selección de accesiones locales, así como la introducción de nuevos genotipos foráneos, como dos vías fundamentales para aumentar la diversidad genética presente en el banco de germoplasma de papaya de Cuba.

Systematic evaluation of options to avoid generation of noncertifiable transuranic (TRU) waste at Los Alamos National Laboratory

International Nuclear Information System (INIS)

Boak, J.M.; Kosiewicz, S.T.; Triay, I.; Gruetzmacher, K.; Montoya, A.

1998-03-01

At present, >35% of the volume of newly generated transuranic (TRU) waste at Los Alamos National Laboratory is not certifiable for transport to the Waste Isolation Pilot Plant (WIPP). Noncertifiable waste would constitute 900--1,000 m 3 of the 2,600 m 3 of waste projected during the period of the Environmental Management (EM) Accelerated Cleanup: Focus on 2006 plan (DOE, 1997). Volume expansion of this waste to meet thermal limits would increase the shipped volume to ∼5,400 m 3 . This paper presents the results of efforts to define which TRU waste streams are noncertifiable at Los Alamos, and to prioritize site-specific options to reduce the volume of certifiable waste over the period of the EM Accelerated Cleanup Plan. A team of Los Alamos TRU waste generators and waste managers reviewed historic generation rates and thermal loads and current practices to estimate the projected volume and thermal load of TRU waste streams for Fiscal Years 1999--2006. These data defined four major problem TRU waste streams. Estimates were also made of the volume expansion that would be required to meet the permissible wattages for all waste. The four waste streams defined were: (1) 238 Pu-contaminated combustible waste from production of Radioactive Thermoelectric Generators (RTGs) with 238 Pu activity which exceeds allowable shipping limits by 10--100X. (2) 241 Am-contaminated cement waste from plutonium recovery processes (nitric and hydrochloric acid recovery) are estimated to exceed thermal limits by ∼3X. (3) 239 Pu-contaminated combustible waste, mainly organic waste materials contaminated with 239 Pu and 241 Am, is estimated to exceed thermal load requirements by a factor of ∼2X. (4) Oversized metal waste objects, (especially gloveboxes), cannot be shipped as is to WIPP because they will not fit in a standard waste box or drum

Adsorption of Cs-137 and U-238 in semi-arid soils

International Nuclear Information System (INIS)

Hernandez T, U. O.; Monroy G, F.; Anguiano A, J.; Fernandez R, E.

2013-10-01

Is of great importance to determine the adsorption properties of the soils where radioactive wastes are stored, fundamentally of the radioisotopes contained in these wastes, with the purpose of knowing like will be their behavior in the event of happening radionuclide migration toward the surrounding means. Therefore, in this work the adsorption properties of 137 Cs + and 238 UO 2 2+ in soils coming from the Storage Center of Radioactive Wastes are studied. Was studied the effect of the soil type and the particle size of the soil in the adsorption properties of Cs (I) and U (Vi). 13 soil samples and six different particle sizes were analyzed. The adsorption studies were carried out by the radiotracers technique in static way. The results indicate an important adsorption affinity toward the Cs-137 and a very vulnerable affinity for the 238 UO 2 2+ . (author)

Doppler-free two-photon excitation of 238U

International Nuclear Information System (INIS)

Hodgkinson, D.P.; Wort, D.J.H.

1981-04-01

A theory of resonantly enhanced two-photon absorption is presented and tested in a number of experiments in which 238 U vapour is excited by two continuous wave dye lasers. Good quantitative agreement between theory and experiment is found. In particular the central prediction of the theory, that antiparallel laser beams of modest intensity can pump an appreciable fraction of the Maxwell velocity distribution, has been checked directly by measuring the spectral width of the fluorescence from the two-photon excited level. (author)

234Th/238U disequilibrium in near-shore sediment: particle reworking and diagenetic time scales

International Nuclear Information System (INIS)

Aller, R.C.; Cochran, J.K.

1976-01-01

The distribution of 234 Th (tsub(1.2)=24.1 days) in excess of its parent 238 U in the upper layers of near-shore sediment makes possible the evaluation of short-term sediment reworking and diagenetic rates. 234 Th has a maximum residence time in Long Island Sound water of 1.4 days. Seasonal measurement of 234 Th/ 238 U disequilibrium in sediment at a single station in central Long Island Sound demonstrates rapid particle reworking and high 234 Thsub(XS)(>1 dpm/g) in the upper 4 cm of sediment with slower, irregular reworking and low 234 Thsub(XS) to at least 12 cm. The rate of rapid particle reworking varies seasonally and is highest in the fall. The rapidly mixed zone is characterized by steep gradients in sediment chemistry implying fast reactions spanned by 234 Th decay time scales. 238 U is depleted in the upper mixed zone and shows addition in reducing sediment at depth. (Auth.)

Mass spectrometric 230Th-234U-238U dating of the Devils Hole calcite vein

International Nuclear Information System (INIS)

Ludwig, K.R.; Simmons, K.R.; Szabo, B.J.; Riggs, A.C.; Winograd, I.J.; Landwehr, J.M.; Hoffman, R.J.

1992-01-01

The Devils Hole calcite vein contains a long-term climatic record, but requires accurate chronologic control for its interpretation. Mass-spectrometric U-series ages for samples from core DH-11 yielding 230 Th ages with precisions ranging from less than 1,000 years (2σ) for samples younger than ∼140 ka (thousands of years ago) to less than 50,000 years for the oldest samples (∼566 ka). The 234 U/ 238 U ages could be determined to a precision of ∼20,000 years for all ages. Calcite accumulated continuously from 566 ka until ∼60 ka at an average rate of 0.7 millimeter per 10 3 years. The precise agreement between replicate analyses and the concordance of the 230 Th/ 238 U and 234 U/ 238 U ages for the oldest samples indicate that the DH-11 samples were closed systems and validate the dating technique in general

Sensitivity analysis of U238 cross sections in fast nuclear systems-SENSEAV-R computer code

International Nuclear Information System (INIS)

Amorim, E.S. de; D'Oliveira, A.B.; Oliveira, E.C. de

1981-01-01

For many performance parameters of reactors the tabulated ratio calculation/experiment indicate that some potential problems may exist either in the cross section data or in the calculation models used to investigate the critical experimental data. A first step toward drawing a more definite conclusion is to perform a selective analysis of sensitivity profiles and covariance data files for the cross section data used in the calculation. Many works in the current literature show that some of these uncertainties come from uncertainties in 238 U(n,γ), 238 U(n,f) 239 Pu(n,f). Perturbation methods were developed to analyze the effects of finite changes in a large number of cross sections and summarize the investigation by a group dependent sensitivity coefficient. As an application, the results of this investigation indicates that improvements should be done only on the medium and low energy ranges of 238 U(n,γ) based on an analysis of cost and economic benefits. (Author) [pt

Frequência de polimorfismos nos genes codificadores das enzimas 17βHSD5 e aromatase em mulheres com diferentes fenótipos da síndrome dos ovários policísticos e resposta ao tratamento com anticoncepcional oral

OpenAIRE

Polyana Sartori Maier

2012-01-01

A Síndrome dos Ovários Policísticos (PCOS) é a endocrinopatia mais frequente em mulheres na idade reprodutiva, além de ser a causa mais comum de hiperandrogenismo e anovulação crônica. Diferentes fenótipos da PCOS foram identificados, e um melhor entendimento dessas diferentes apresentações clínicas se faz necessário para o reconhecimento de riscos, medidas preventivas e terapêuticas específicas para cada fenótipo. Associações entre polimorfismos de substituição de um único nucleotídeo (SNPs)...

Contamination level of natural 238U and 232Th radionuclides in offshore of coal power plant (assessment at offshore of Panjang Island and Lada Bay, Banten)

International Nuclear Information System (INIS)

Sabam Parsaoran Situmorang; Harpasis Selamet Sanusi; June Mellawati

2011-01-01

This study had been carried out by collecting sample of the surficial sediments, sea water, seaweeds, anchovies (Stolephorus and Anchoa) and mussels (Codakia) from 4 locations in waters of Pulau Panjang and coastal of Lada Bay (as control/comparison site), Banten in June - July 2010. Natural radionuclides (Th) concentration in samples was measured using neutron activation analysis (NAA) method. The results showed that the total radionuclides concentration in sediment ( 238 U: 18.6160 - 35.0013 Bq/kg; 232 Th: 11.2020 - 35.6685 Bq/kg), seawater ( 238 U: undetected; 232 Th: 0.0790 - 0.1299 Bq/l), cultivation seaweeds ( 238 U: undetected; 232 Th: 3.6735 - 4.8345 Bq/kg), natural seaweeds ( 238 U: 3.6851 - 48.0430 Bq/kg; 232 Th: 3.9941 - 9.0788 Bq/kg), Stolephorus ( 238 U: undetected; 232 Th: 3.3078 Bq/kg) and Codakia ( 238 U: 6.8903 Bq/kg; 232 Th: 3.6023 Bq/kg) in Pulau Panjang, Banten around Suralaya coal power plant higher than control site that were around the Labuan coal power plant, namely in sediments ( 238 U: 10.4253 Bq/kg; 232 Th: 16.5952 Bq/kg), seawater( 238 U: undetected; 232 Th: 0.0671 Bq/l), cultivation seaweeds ( 238 U: undetected; 232 Th: 2.3005 Bq/kg), natural seaweeds ( 238 U: 19.5367 Bq/kg; 232 Th: 2.6729 Bq/kg) and Anchoa ( 238 U: undetected; 232 Th: 2.0603 Bq/kg). (author)

Quasifree electrofission of 238U

International Nuclear Information System (INIS)

Likhachev, V.P.; Deppman, A.; Hussein, M.S.; Mesa, J.; Arruda-Neto, J.D.T.; Carlson, B.V.; Nesterenko, V.O.; Garcia, F.; Rodriguez, O.

2002-01-01

We present the result of a theoretical study of the quasifree electrofission of 238 U. The exclusive differential cross sections for the quasifree scattering reaction stage have been calculated in plane wave impulse approximation, using a macroscopic-microscopic approach for the description of the proton bound states. The nuclear shape was parametrized in terms of Cassinian ovoids. The equilibrium deformation parameters have been calculated by minimizing the total nuclear energy. In the calculation the axially deformed Woods-Saxon single-particle potential was used. The obtained single-particle momentum distributions were averaged over the nuclear symmetry axis direction. The occupation numbers were calculated in the BCS approach. The fissility for the single-hole excited states of the residual nucleus 237 Pa was calculated on the statistical theory grounds, both without taking into account the preequilibrium emission of the particle and with preequilibrium emission in the framework of the exciton model

Late effects of inhaled 238PuO2 in beagles

International Nuclear Information System (INIS)

Park, J.F.; Case, A.C.; Catt, D.L.; Hackett, P.L.; Lund, J.E.; Powers, G.J.; Ragan, H.A.; Watson, C.R.

1976-01-01

Osteosarcomas were the primary cause of death in beagle dogs 4 to 8 years after inhalation of 238 PuO 2 . The plutonium body burden at death ranged from 0.4 to 2.6 μCi with 32 to 55 percent of the plutonium in the skeleton. Pulmonary neoplasia was observed in three of the bone-tumor-bearing dogs

Neutron induced fission cross section ratios for 232Th, /sup 235,238/U, 237Np, and 239Pu from 1 to 400 MeV

International Nuclear Information System (INIS)

Lisowski, P.W.; Ullmann, J.L.; Balestrini, S.J.; Carlson, A.D.; Wasson, O.A.; Hill, N.W.

1988-01-01

Time-of-flight measurements of neutron induced fission cross section ratios for 232 Th, /sup 235,238/U, 237 Np, and 239 Pu, were performed using the WNR high intensity spallation neutron source located at Los Alamos National Laboratory. A multiple-plate gas ionization chamber located at a 20-m flight path was used to simultaneously measure the fission rate for all samples over the energy range from 1 to 400 MeV. Because the measurements were made with nearly identical neutron fluxes, we were able to cancel many systematic uncertainties present in previous measurements. This allows us to resolve discrepancies among different data sets. In addition, these are the first neutron-induced fission cross section values for most of the nuclei at energies above 30 MeV. 8 refs., 3 figs

238U-series radionuclides in Finnish groundwater-based drinking water and effective doses

International Nuclear Information System (INIS)

Vesterbacka, P.

2005-09-01

The thesis deals with the occurrence of 238 U-series radionuclides and particle-bound 210 Pb and 210 Po in Finnish groundwater-based drinking water, methods used for removing 234 U, 238 U, 210 Pb and 210 Po, and the annual effective doses caused by 238 U-series radionuclides in drinking water. In order to reduce radiation exposure and avoid high doses, it is important to examine the activity levels of natural radionuclides in groundwater. In this work, the activity concentrations of radon ( 222 Rn), radium ( 226 Ra), uranium ( 238 U and 234 U), lead ( 210 Pb) and polonium ( 210 Po) were determined from 472 private wells, which were selected randomly from across Finland. On the basis of the results, the activity concentrations in groundwater and the radiation exposure from drinking water of people living outside the public water supply in Finland was specified. The efficiency of 238 U, 234 U, 210 Pb and 210 Po removal from drinking water was examined at ten private homes. In order to obtain accurate results and correct estimates of effective doses, attention was paid to the sampling of 222 Rn and 210 Pb, and the determination of 210 Pb. The results revealed that the median activity concentrations of natural radionuclides were as much as ten times higher in drilled wells than in wells dug in soil. The average activity concentration of 222 Rn in drilled wells was 460 Bq/l and in dug wells 50 Bq/l. The highest activity concentrations were found in Southern Finland. In addition, occasional high activity concentrations were found all over Finland. The average activity concentrations of 234 U and 238 U in drilled wells were 0.35 and 0.26 Bq/l and in dug wells 0.020 and 0.015 Bq/l, respectively. The spatial distribution of 234 U, 238 U, 210 Pb and 210 Po was essentially similar to that of 222 Rn. In contrast to other natural radionuclides, the highest 226 Ra activity concentrations were found in coastal areas, since drilled well water near the sea has a higher salinity

Field study of the migration of 237Np, 238Pu and 241Am in a weak loess aquifer

International Nuclear Information System (INIS)

Liu, C.L.; Wang, Z.M.; Li, S.S.; Yang, Y.E.; Li, B.; Jiang, H.; Jiang, L.; Wang, L.; Li, D.

2004-01-01

The migration of 237 Np, 238 Pu and 241 Am in a weak loess aquifer was investigated in-situ in an Underground Research Facility. Quartz containing 237 Np, 238 Pu, 241 Am and 3 H was introduced into the aquifer with a stainless steel tube. The local water flow in the aquifer was monitored using a 3-dimensional sampling system. The contaminated area of the aquifer was obtained wholly with the help of a pre-installed stainless steel frame and cut into small pieces (samples) 3-dimensionally and analyzed. 3 H in the water samples was determined with a liquid scintillation analyzer (Tri-Camb 2250). Radioactivity of 237 Np and 241 Am in the soil samples were determined with a low energy photon detector (HPGe), 238 Pu was analyzed with a low background αandβ detector after chemical separation. The result of the 3-year experiment indicated that 237 Np, 238 Pu and 241 Am were strongly absorbed by the loess aquifer. The retardation factor of 237 Np in the loess aquifer was 1.54 x 10 4 . (author)

Toxicity of inhaled 238PuO2 I

International Nuclear Information System (INIS)

Diel, J.H.; Mewhinney, J.A.

1980-01-01

The deposition, retention, translocation and microscopic distribution of inhaled 238 PuO 2 particles were studied to better define the organs at risk and uniformity of dose and cell types or structures at risk in the lung. Beagle dogs were exposed once by inhalation to an aerosol of 238 PuO 2 with particle aerodynamic diameters of 0.7, 1.4, or 2.7 μm (+-10%). Initial burdens averaged about 700 nCi, a level not expected to induce life-shortening effects in Beagle dogs. Animals were sacrificed at times from 4 hours to 2 years after exposure. Whole body retention of plutonium and its distribution among organs in the sacrificed animals was determined by radiochemical analysis for plutonium content of excreta and tissue samples. The distribution of particles in lung was determined using autoradiographs of lung tissue sections and computer-assisted data collection and analysis. Soon after exposure, PuO 2 was relatively insoluble in lung with individual particles being randomly distributed throughout the lung. A distinct change in the rate of dissolution from lung occurred at about 100 days after exposure resulting in decreased pulmonary retention and increased uptake by liver and skeleton. Particle breakup was observed in autoradiographs for time periods in excess of 128 days after exposure. Broken up particles dissolved rapidly leaving little residue in the lung. The remaining particles were randomly distributed in the lung. These results are discussed in relation to current radiation protection guides for plutonium radionuclides. (author)

Investigate the capability of INAA absolute method to determine the concentrations of 238U and 232Th in rock samples

International Nuclear Information System (INIS)

Alnour, I.A.

2014-01-01

This work aimed to study the capability of INAA absolute method in determining the elemental concentration of 238 U and 232 Th in the rock samples. The INAA absolute method was implemented in PUSPATI TRIGA Mark II research reactor, Malaysian Nuclear Agency (NM). The accuracy of INAA absolute method was performed by analyzing the IAEA certified reference material (CRM) Soil-7. The analytical results showed the deviations between experimental and certified values were mostly less than 10 % with Z-score in most cases less than 1. In general, the results of analysed CRM Soil-7 show a good agreement between certified and experimental results which mean that the INAA absolute method can be used accurately for elemental analysis of uranium and thorium in various types of samples. The concentration of 238 U and 232 Th ranged from 1.77 to 24.25 and 0.88 to 95.50 ppm respectively. The highest value of 238 U and 232 Th was recorded for granite rock sample G17 of 238 U and sample G9 of 232 Th, whereas the lower value was 1.77 ppm of 238 U recorded in sandstone rock and 0.88 ppm of 232 Th for gabbro. Moreover, a comparison of the 238 U and 232 Th results obtained by the INAA absolute method shows an acceptable level of consistency with those obtained by the INAA relative method. (author)

Uranium 234U and 238U isotopes in the southern Baltic environment

International Nuclear Information System (INIS)

Borylo, A.; Skwarzec, B.

2002-01-01

The concentration and distribution of uranium in water and sediment of selected basins of the southern Baltic Sea have been analysed. It was observed that the concentration of uranium in sediments increases with core depth. This is probably connected to diffusion processes from sediments to water through interstitial water where uranium concentration is much higher than in bottom water. The measurements of 234 U/ 238 U activity ratios indicate that sedimentation of terrigenic material and transport through Vistula river are the major sources of uranium in sediments of the southern Baltic Sea. Estimation of the 234 U/ 238 U ratios in reduction areas of the Baltic Deep and the Bornholm Deep suggest that the processes of reduction of U(VI) to U(IV) and of removal of authogenic uranium from seawater to sediments do not play major roles in the Gdansk Deep. (author)

Distribution of 238Pu and 239240Pu in aquatic macrophytes from a midwestern watershed

International Nuclear Information System (INIS)

Wayman, C.W.; Bartelt, G.E.; Alberts, J.J.

1977-01-01

Aquatic macrophytes were collected in the Great Miami River, Ohio, above and below Miamisburg and in the canal and ponds, near the Mound Laboratory, which contain sediments of a high activity (approximately 10 3 to 10 6 times) relative to the river sediments. Macrophytes collected in the river below Miamisburg have higher activities of 238 Pu than those collected from above the city. Macrophytes from the canal and ponds contain high specific activities of 238 Pu and 239 , 240 Pu with the exception of cattails grown in the ponds. Concentration factors are reported and discussed with reference to possible modes of plutonium accumulation and distribution within the plants

Caracterización citogenética del tinajo o borugo Agouti taczanowskii de Colombia

Directory of Open Access Journals (Sweden)

Torres Olga María

2000-12-01

Full Text Available We describe the cytogenetics of the mountain paca, A. teczenowskii, which inhabits the mountains of Colombia. It was established that A. taczanowskií has a diploid number of 78 chromosomes with fairly large amounts of constitutive heterochromatin and remarkable C-band polymorphism. These results permit the differentiation of individuals and may shed light on the family status of the genus Agouti.Este trabajo presenta los cariotipos G, R Y C del tinajo o borugo A. taczanowskii que habita en los Andes de Colombia. A. taczanowskií posee 78 cromosomas, con una cantidad relativamente grande de heterocromatina constitutiva y un notable polimorfismo de bandas C, que permitió la identificación individual de los animales estudiados. Los resultados encontrados constituyen un punto de referencia importante para la taxonomía del género Agouti.

Tritium concentrations in bees and honey at Los Alamos National Laboratory

International Nuclear Information System (INIS)

Fresquez, P.R.; Armstrong, D.R.; Salazar, J.G.

1994-12-01

Los Alamos National Laboratory (LANL) has maintained a network of honey bee colonies at LANL, perimeter (Los Alamos townsite and White Rock/Pajarito Acres) and regional (background) areas for over 15 years; the main objective of this honey bee network was to help determine the bioavailability of certain radionuclides in the environment. Of all the radionuclides studied ( 3 H, 57 Co, 7 Be, 22 Na, 54 Mn, 83 Rb, 137 Cs, 238 Pu, 239 Pu, 90 Sr and total U), tritium was consistently detected in bees and was most readily transferred to the honey. In fact, honey collected from hives located at TA-21, TA-33, TA-50, TA-53, and TA-54 and from White Rock/Pajarito Acres contained significantly higher concentrations of 3 H than regional background hives. Based on the average concentration of all radionuclides measured over the years, the effective dose equivalent (EDE) from consuming 5 kg (11 lb) of honey collected from Los Alamos (townsite) and White Rock/Pajarito Acres, after regional background has been subtracted, was 0.0186 (±0.0507) and 0.0016 (±0.0010) mrem/yr, respectively. The highest EDE, based on the mean + 2SD (95% confidence level), was 0.1200 mrem/y; this was <0.2% of the International Commission on Radiological Protection permissible dose limit of 100 mrem/yr from all pathways

Two types of adakites revealed by 238U-230Th disequilibrium from Daisen volcano, southwestern Japan

International Nuclear Information System (INIS)

Tokunaga, Saimi; Nakai, Shun'ichi; Orihashi, Yuji

2010-01-01

Daisen volcano is located on the Quaternary volcanic front in southwestern Japan. The volcano is composed mainly of andesite and dacite, which chemically resemble adakites, with high Al 2 O 3 and Sr/Y, steep REE patterns, and no negative Eu anomaly. ( 238 U/ 230 Th) disequilibrium (herein, a ratio in parentheses denotes the activity ratio) and trace element analyses of adakites from two volcanic domes, Karasugasen and Misen, indicate two adakite types. Adakite from Karasugasen is characterized by excess ( 230 Th) over ( 238 U), typical of most adakites, whereas adakite from Misen is characterized by excess ( 238 U) over ( 230 Th). The latter is consistent with enrichment in fluid-mobile elements relative to fluid immobile elements compared to rocks from Karasugasen. The values of ( 230 Th/ 232 Th) of adakites from Karasugasen and Misen are, respectively, around 0.75 and 0.81. These low ( 230 Th/ 232 Th) ratios result from the incorporation of subducted sedimentary material. The ratios, nevertheless, are higher than that for the estimate of lower crustal material suggesting significant incorporation of lower crust is unlikely. As adakites from Misen have ( 238 U) excess over ( 230 Th), adakite magma must have interacted with wedge mantle metasomatized by a slab-derived fluid, confirming the presence of a fluid-metasomatized mantle beneath Daisen volcano. (author)

Nonradiative excitation of the muonic atom 238U as an inverse conversion process

International Nuclear Information System (INIS)

Karpeshin, F.F.; Nesterenko, V.U.

1982-01-01

The probabilities of nonradiation nuclear excitation are calculated for different muon transitions in the muonic atom 238 U. Microscopic nuclear wave functions, obtained within the quasiparticle-phonon nuclear model and the muonic conversion coefficients have been used. The probability of nonradiation nuclear excitation for the muonic transitions 2p → 1s and 3p → 1s has been found to be equal to 0.3. It is predicted that nonradiative E3 transitions 3d → 2p can take place with the probability 0.08-0.10. The dynamic effect of nuclear structure on the probability of nonradiative nuclear excitation is taken into account. The estimates of 238 U fissility fission branching at nonradiation transitions are also obtained

The Determination of the Half-Life of U{sup 238} by Absolute Counting of {alpha} Particles in a 4 {pi}-Liquid Scintillation Counter; Determination de la periode de l'U{sup 238} au moyen du comptage absolu de particules {alpha} dans un comtpeur 4 {pi} a scintillateur liquide; Opredelenie perioda poluraspadda U{sup 238} posredstvom absolyutnogo scheta {alpha}-chastits v zhidkostnom stsintillyatsionnom schetchike 4 {pi}; Determinacion del periodo del U{sup 238} por recuento absoluto de las particulas {alpha} con un contador 4 {pi} de centelleador liquido

Energy Technology Data Exchange (ETDEWEB)

Steyn, J; Strelow, F W. E. [Council of Scientific and Industrial Research, Pretoria (South Africa)

1960-06-15

The specific activity of natural uranium was determined by liquid scintillation {alpha}-counting. Uranium was extracted from its decay products by methyl isobutyl ketone extraction and samples of this solution were added directly to the liquid scintillator. A quantitative investigation was made of the separation of uranium from thorium by the extraction method employed. Assuming that U{sup 238} and U{sup 234} were in equilibrium, and correcting for the presence of U{sup 235}, the specific activity and the half-life of the isotope U{sup 238} were calculated. (author) [French] L'activite specifique de l'uranium naturel est determinee au moyen d'un comptage a par scintillateur liquide. L'uranium est separe de ses produits de desintegration par une extraction a la methylisobutylceton e et des echantillons de cette solution sont ajoutes directement au scintillateur liquide. On fait une etude quantitative de la separation de l'uranium et du thorium par le procede d'extraction utilise. En admettant que U{sup 238} et U{sup 234} sont en equilibre et en faisant la correction voulue pour tenir compte de la presence de U{sup 235}, on calcule l'activite specifique et la periode de U{sup 238}. (author) [Spanish] La actividad especifica del uranio natural se determino con un contador {alpha} de centelleador liquido. El uranio se separo de productes de desintegracion por extraccion con metilisobutilcetona, y muestras de esta solucion se anadieron directamente al centelleador liquido. Se estudio cuantitativament e el grado de separacion uranio/torio alcanzado con el metodo de extraccion empleado. Introduciendo correcciones para tener en cuenta la presencia de U{sup 235}, se calculo la actividad especifica y el periodo de semidesintegracio n del U{sup 238} suponiendo que este isotopo se encontraba en equilibrio con el U{sup 234}. (author) [Russian] Spetsificheskaya aktivnost' estestvennogo urana byla opredelena s pomoshch'yu zhidkostnogo stsintillyatsionnog o schetchika {alpha

Colombia: El Contexto de la Desigualdad y la Pobreza Rural en los Noventa

Directory of Open Access Journals (Sweden)

Gómez Jiménez Alcides

2003-08-01

Full Text Available

Gómez, Alcides. "Colombia: El Contexto de la Desigualdad y la Pobreza Rural en los Noventa", Cuadernos de Economía, V. XXII, n. 38, Bogotá, 2003, páginas 199-238.

Este articulo analiza: iLos nefastos efectos sociales derivados del modelo de apertura a la economía internacional y su contradicción con la primacía de la política social consagrada en la constitución de 1991; iiUna aproximación a la relación entre política macroeconómica, desigualdad y pobreza; iii El acelerado aumento de la pobreza y la desigualdad y la brecha creciente urbano rural; ivEl Proceso de acaparamiento de tierras sin precedentes, con fines especulativos. La conformación de un moviemiento social y político fuera de la tutela de los partidos históricos, la visión estratégica de las elites dominantes, así como la visión del modelo de acumulación de capital que estas tengan, son las variables estratégicas que podrian determinar el rumbo del futuro, bien de reforma agraría, de reforma rural o de mantenimeinto temporal del actual status quo.

Uranium ({sup 238}U)-induced ROS and cell cycle perturbations, antioxidant responses and erythrocyte nuclear abnormalities in the freshwater iridescent shark fish Pangasius sutchi

Energy Technology Data Exchange (ETDEWEB)

Annamalai, Sathesh Kumar; Arunachalam, Kantha Deivi, E-mail: kanthad.arunachalam@gmail.com

2017-05-15

Highlights: • Exposure to {sup 238}U deteriorated the antioxidant defenses like SOD, CAT and LPO. • Flow cytometric analysis revealed the increase in G2/M phase and S phase. • Micronucleus frequencies increased with Increased {sup 238}U exposure and time. • Exposure to waterborne {sup 238}U induces both chemical and radiotoxicity in P. sutchi. • ROS-mediated {sup 238}U toxic mechanism and the antioxidant responses has been proposed. - Abstract: The strategic plan of this study is to analyze any possible radiological impact on aquatic organisms from forthcoming uranium mining facilities around the Nagarjuna Sagar Dam in the future. The predominantly consumed and dominant fish species Pangasius sutchi, which is available year-round at Nagarjuna Sagar Dam, was selected for the study. To comprehend the outcome and to understand the mode of action of {sup 238}U, the fish species Pangasius sutchi was exposed to ¼ and ½ of the LC{sub 50} doses of waterborne {sup 238}U in a static system in duplicate for 21 days. Blood and organs, including the gills, liver, brain and muscles, were collected at different time periods—0 h, 24 h, 48 h, 72 h, 96 h, 7, days 14 days and 21 days—using ICP-MS to determine the toxic effects of uranium and the accumulation of {sup 238}U concentrations. The bioaccumulation of {sup 238}U in P. sutchi tissues was dependent on exposure time and concentration. The accumulation of uranium was, in order of magnitude, measured as gills > liver > brain > tissue, with the highest accumulation in the gills. It was observed that exposure to {sup 238}U significantly reduced antioxidant enzymes such as superoxide dismutase, catalase, and lipid peroxidase. The analysis of DNA fragmentation by comet assay and cell viability by flow cytometry was performed at different time intervals. DNA histograms by flow cytometry analysis revealed an increase in the G2/M phase and the S phase. The long-term {sup 238}U exposure studies in fish showed increasing

Radioactive Contamination of Alluvial Soils in the Taiga Landscapes of Yakutia with 137Cs, 226Ra, and 238U

Science.gov (United States)

Chevychelov, A. P.; Sobakin, P. I.

2017-12-01

The concentrations and distribution of 137Cs in alluvial soils (Fluvisols) of the upper and middle reaches of the Markha River in the northwest of Yakutia and 226Ra and 238U in alluvial soils within the El'kon uranium ore deposit in the south of Yakutia have been studied. It is shown that the migration of radiocesium in the permafrost-affected soils of Yakutia owing to alluviation processes extends to more than 600 km from the source of the radioactive contamination. The migration of 137Cs with water flows is accompanied by its deposition in the buried horizons of alluvial soils during extremely high floods caused by ice jams. In the technogenic landscapes of southern Yakutia, active water migration of 238U and 226Ra from radioactive dump rocks. The leaching of 238U with surface waters from the rocks is more intense than the leaching of 226Ra. The vertical distribution patterns of 238U and 226Ra in the profiles of alluvial soils are complex. Uranium tends to accumulate in the surface humus horizon and in the buried soil horizons, whereas radium does not display any definite regularities of its distribution in the soil profiles. At present, the migration of 238U and 226Ra with river water and their accumulation in the alluvial soils extend to about 30 km from the source.

A remarkable systemic error in calibration methods of γ spectrometer used for determining activity of 238U

International Nuclear Information System (INIS)

Su Qiong; Cheng Jianping; Diao Lijun; Li Guiqun

2006-01-01

A remarkable systemic error which was unknown in past long time has been indicated. The error appears in the calibration methods of determining activity of 238 U is used with γ-spectrometer with high resolution. When the γ-ray of 92.6 keV as the characteristic radiation from 238 U is used to determine the activity of 238 U in natural environment samples, the disturbing radiation produced by external excitation (or called outer sourcing X-ray radiation) is the main problem. Because the X-ray intensity is changed with many indefinite factors, it is advised that the calibration methods should be put away. As the influence of the systemic errors has been left in some past research papers, the authors suggest that the data from those papers should be cited carefully and if possible the data ought to be re-determined. (authors)

Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on 239Pu, 235U, 238U

International Nuclear Information System (INIS)

Selby, H.D.; Mac Innes, M.R.; Barr, D.W.; Keksis, A.L.; Meade, R.A.; Burns, C.J.; Chadwick, M.B.; Wallstrom, T.C.

2010-01-01

We describe measurements of fission product data at Los Alamos that are important for determining the number of fissions that have occurred when neutrons are incident on plutonium and uranium isotopes. The fission-spectrum measurements were made using a fission chamber designed by the National Institute for Standards and Technology (NIST) in the BIG TEN critical assembly, as part of the Inter-laboratory Liquid Metal Fast Breeder Reactor (LMFBR) Reaction Rate (ILRR) collaboration. The thermal measurements were made at Los Alamos' Omega West Reactor. A related set of measurements were made of fission-product ratios (so-called R-values) in neutron environments provided by a number of Los Alamos critical assemblies that range from having average energies causing fission of 400-600 keV (BIG TEN and the outer regions of the Flattop-25 assembly) to higher energies (1.4-1.9 MeV) in the Jezebel, and in the central regions of the Flattop-25 and Flattop-Pu, critical assemblies. From these data we determine ratios of fission product yields in different fuel and neutron environments (Q-values) and fission product yields in fission spectrum neutron environments for 99 Mo, 95 Zr, 137 Cs, 140 Ba, 141,143 Ce, and 147 Nd. Modest incident-energy dependence exists for the 147 Nd fission product yield; this is discussed in the context of models for fission that include thermal and dynamical effects. The fission product data agree with measurements by Maeck and other authors using mass-spectrometry methods, and with the ILRR collaboration results that used gamma spectroscopy for quantifying fission products. We note that the measurements also contradict earlier 1950s historical Los Alamos estimates by ∼5-7%, most likely owing to self-shielding corrections not made in the early thermal measurements. Our experimental results provide a confirmation of the England-Rider ENDF/B-VI evaluated fission-spectrum fission product yields that were carried over to the ENDF/B-VII.0 library, except

High energy resolution measurement of the 238U neutron capture yield in the energy region between 1 and 100 keV

International Nuclear Information System (INIS)

Machlin, R.L.; Perez, R.B.; de Saussure, G.; Ingle, R.W.

1988-01-01

A measurement of the 238 U neutron capture yield was performed at the 150 meter flight-path of the ORELA facility on two 238 U samples (0.01224 and 0.0031 atomsbarn). The capture yeild data were normalized by Moxon's small resonance method. The energy resolution achieved in this measurement frequently resulted in doublet and triplet splittings of what appeared to be single resonance in previous measurements. This resolution should allow extension of the resolved resonance energy region in 238 U from the present 4-keV limit up to 15 or 20 keV incident neutron energy. Some 200 small resonances of the ( 238 U /plus/ n) compound nucleus have been observed which had not been detected in transmission measurement, in the energy range from 250 eV to 10 keV

Design improvements for gloveboxes used [in] {sup 238}PuO{sub 2} process operations

Energy Technology Data Exchange (ETDEWEB)

George, T.G. [Los Alamos National Lab., NM (United States). Nuclear Materials Technology Div.

1997-09-01

{sup 238}PuO{sub 2} process operations are housed in a complex of 76 gloveboxes and introductory hoods connected by means of an overhead trolley housed in a tunnel. Because a significant number of the gloveboxes used for {sup 238}PuO{sub 2} processing were installed before the original startup of the facility in 1978, they have been in service for nearly 20 years. During a recent heat source production campaign, numerous contamination releases in the {sup 238}PuO{sub 2} processing area were traced to degraded elastomer gaskets used for glovebox connections, and attachment of feed-throughs, service panels, and windows. Evaluation of the degraded gaskets revealed that a combination of radiolytic degradation related to the high specific activity of {sup 238}Pu, and extended service at high altitude in a low (to extremely low) humidity environment had resulted in accelerated gasket aging. However, it was also apparent that gasket design was the most important factor in actual contamination release. All of the contamination releases that were traced to degraded gaskets occurred in variations of a design that used a spline to expand an elastomeric gasket into the space between a connecting flange, window, or service panel, and a glovebox opening. No contamination releases were traced to the gasket design that employed bolted clamps to compress the gasket between a connecting flange, window, or panel, and the exterior surface of a glovebox opening. As a result of these findings, the Actinide Ceramics group at LANL (NMT-9) has initiated a routine replacement and upgrade program to replace aging gloveboxes. All of the new gloveboxes will utilize the preferred gasket design, which is expected to reduce the number and frequency of contamination releases.

Measurement of Fragment Mass Distributions in Neutron-induced Fission of 238U and 232Th at Intermediate Energies

International Nuclear Information System (INIS)

Simutkin, V.D.

2008-01-01

Conceptual analysis of accelerator-driven systems assumes extensive use of nuclear data on neutron-induced reactions at intermediate energies. In particular, information about the fission fragment yields from the 238 U(n,f) and 232 Th(n,f) reactions is of particular interest at neutron energies from 10 to 200 MeV. However, there is a lack of such data for both 238 U and 232 Th. Up to now, the intermediate energy measurements have been performed for 238 U only, and there are no data for the 232 Th(n,f) reaction. The aim of the work is to provide such data. Fission fragment mass distributions for the 232 Th(n,f) and 238 U(n,f) reactions have been measured for the incident neutron energies 32.8 MeV, 45.3 MeV and 59.9 MeV. The experiments have been performed at the neutron beam facility of the Universite Catholique de Louvain, Belgium. A multi-section Frisch-gridded ionization chamber has been used as a fission fragment detector. The data obtained have been interpreted in terms of the multimodal random neck-rupture model (MMRNRM). (authors)

Variación de la coloración en poblaciones argentinas de Melanophryniscus rubriventris (Vellard, 1947)

OpenAIRE

Vaira, Marcos

2002-01-01

Tanto los patrones como el tono de la coloración dorsal y ventral han sido caracteres comúnmente utilizados para el reconocimiento y diferenciación de numerosas especies y subespecies del género de Bufonidae Melanophryniscus. Sin embargo, raramente se han presentado análisis detallados y sistematizados que indiquen la ausencia o la baja frecuencia de polimorfismos en estos caracteres para asegurar que son realmente diagnósticos. Mediante una metodología sistematizada se estableció la validez ...

Variación de la coloración en poblaciones argentinas de Melanophryniscus rubriventris (Vellard, 1947)

OpenAIRE

Vaira, Marcos

2002-01-01

Tanto los patrones como el tono de la coloración dorsal y ventral han sido caracteres comúnmente utilizados para el reconocimiento y diferenciación de numerosas especies y subespecies del género de Bufonidae Melanophryniscus. Sin embargo, raramente se han presentado análisis detallados y sistematizados que indiquen la ausencia o la baja frecuencia de polimorfismos en estos caracteres para asegurar que son realmente diagnósticos. Mediante una metodología sistematizada se estableció la validez ...

Phosphate fertilizer influence on {sup 238} U content in vegetables

Energy Technology Data Exchange (ETDEWEB)

Lauria D, C.; Rodrigues S, J.I. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN), Av. Salvador Allende s/n, Rio de Janeiro-RJ (Brazil); Ribeiro, F.C.A. [Centro Regional de Ciencias Nucleares (CRCN/CNEN) Av. Prof. Luiz Freire 200 Cidade Universitaria Recife-PE (Brazil)]. e-mail: dejanira@ird.gov.br

2006-07-01

Uranium is a naturally radioactive element, which is usually found in soils, superficial and ground water, vegetables and animals. After ingestion by human beings, most is excreted in few days by feces and urine, without reaching the bloodstream. However, a small part circulates through the body, being accumulated in the soft tissues, as kidneys. A minor fraction can remain in bones per some years, being able through the radioactive decay to irradiate adjacent tissues. Phosphate fertilizers used in conventional crop management can present variable amounts of uranium. In accordance with origin and use, the fertilizer can raise the content of this element in vegetables, and consequently to increase the human exposure for radiation due the consumption of vegetables. It is estimated that the use of phosphate fertilizer has at least doubled the prolonged exposure of humans from ingestion of food. This work aims to evaluate the contribution of organic and chemical fertilizer on the concentration of {sup 238} U in vegetable samples. An experiment with black beans (a very important vegetable for Brazilian people) was conducted in a field which soil has never been fertilized with any sort of fertilizer, located near to the Rio de Janeiro city. On the organic management, bovine manure was used, while on conventional management urea, potassium chloride and superphosphate were used. Simultaneously, black bean samples from not fertilized management were collected. In addition, lettuce and carrot samples from organic and conventional managements were collected in Nova Friburgo farms (the most important vegetable supplier of Rio de Janeiro city market). The analyses of {sup 238} U have been carried out by conventional fluorimetric method. The geometric mean of {sup 238} U concentrations in the carrot and lettuce samples from conventional management were similar with those from organic management, while for beans the conventional samples had higher values than those ones found in

Plutonium uptake by plants from soil containing plutonium-238 dioxide particles. Final report

International Nuclear Information System (INIS)

Brown, K.W.; McFarlane, J.C.

1977-05-01

Three plant species--alfalfa, lettuce, and radishes were grown in soils contaminated with plutonium-238 dioxide (238)PuO2 at concentrations of 23, 69, 92, and 342 nanocuries per gram (nCi/g). The length of exposure varied from 60 days for the lettuce and radishes to 358 days for the alfalfa. The magnitude of plutonium incorporation as indicated by the discrimination ratios for these species, after being exposed to the relatively insoluble PuO2, was similar to previously reported data using different chemical forms of plutonium. Evidence indicates that the predominant factor in plutonium uptake by plants may involve the chelation of plutonium contained in the soils by the action of compounds such as citric acid and/or other similar chelating agents released from the plant roots

239 240Pu and 238Pu in sediments of the Hudson River estuary

International Nuclear Information System (INIS)

Linsalata, P.; Wrenn, M.E.; Cohen, N.; Singh, N.P.

1980-01-01

Plutonium-239,240 and plutonium-238 were determined in 59 Hudson River sediment dredge samples collected during 1973-77 in the vicinity of the Indian Point Nuclear Power Station. Acid leaching followed by solvent extraction, electrodeposition, and alpha-spectrometry were used to extract, purify, and quantitate plutonium isotopes present in these samples. Annual median plutonium-238/plutonium-239,240 isotopic activity ratios in surficial sediments were 0.032 (1973-74), 0.035 (1975), 0.042 (1976), and 0.040 (1977). The source of these nuclides in the estuary was identified by analysis of the sample isotopic activity ratios. On the basis of the sampling regimen and the methods used, it is concluded that no input, other than that of fallout, has contributed significantly to the plutonium burden in Hudson sediments

33 CFR 2.38 - Waters subject to the jurisdiction of the United States; waters over which the United States has...

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Waters subject to the jurisdiction of the United States; waters over which the United States has jurisdiction. 2.38 Section 2.38 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL JURISDICTION...

Estudio molecular preliminar de accesiones de maíz (Zea maysL. criollo e indígena Colombiano, utilizando una región de ADN cloroplástico

Directory of Open Access Journals (Sweden)

Ediel Armando Revelo Portilla

2015-01-01

Full Text Available Se exploró en forma preliminar la diversidad genética existente en las 23 razas de maíz criollo e indígena descritas para Colombia por Roberts y colaboradores (1957, para el efecto se evaluaron 28 cebadores nucleares y cloroplásticos. Catorce de ellos amplificaron en la reacción en cadena de la polimerasa (PCR y fueron enviados para secuenciar a Macrogen Inc. (Corea. Mediante programas bioinformáticos (BioEdit 7.1.0, ClustalW versión 1.81, EditPlus Text Editor versión 3.20 y Gblock 0.91b 8 se encontró que ocho de estos cebadores presentaron un nivel alto de polimorfismo. La región genómica cloroplástica AtpB-1-RbcL-1 mostró el mayor polimorfismo y por tanto se utilizó para evaluar 23 materiales representativos de las 23 razas conservadas en el Banco de Germoplasma del CIMMYT (Centro Internacional de Mejoramiento de Maíz y Trigo en México. Con el análisis de secuencias se revalidaron y confrontaron los grupos raciales obtenidos en el presente estudio -tres razas primitivas, siete razas probablemente introducidas, y 13 razas híbridas colombianas- con aquellos establecidos por Roberts y colaboradores, en los cuales se encontraron dos razas primitivas, nueve probablemente introducidas y 12 híbridas colombianas y con los grupos establecidos por Cardona (2010 utilizando la metodología Ward-MLM para los mismos caracteres descritos por Roberts et al. (1957, donde se encontraron cinco razas primitivas, siete probablemente introducidas y nueve híbridas colombianas. Con base en lo anterior, en el presente trabajo se hizo un aporte metodológico para revalidar datos históricos y redefinir grupos raciales.

Ausência de associação entre polimorfismo do gene da interleucina-1 beta e o prognóstico de pacientes com traumatismo crânio-encefálico grave Lack of association between interleukin-1 gene polymorphism and prognosis in severe traumatic brain injury patients

Directory of Open Access Journals (Sweden)

Taís Frederes Krämer Alcalde

2009-12-01

Full Text Available OBJETIVO: O traumatismo crânio-encefálico é a principal causa de óbito em indivíduos com idade entre 1 a 45 anos. O desfecho do traumatismo crânio-encefálico pode estar relacionado, além de fatores pré-morbidade e gravidade do dano, com fatores genéticos. Genes que podem ter relação com o resultado pós-trauma vêm sendo estudados, porém, ainda existem poucas informações sobre a associação entre polimorfismos genéticos e o desfecho do traumatismo crânio-encefálico. O gene da interleucina-1 beta (IL-1B é um dos genes estudados, pois esta citocina encontra-se em níveis elevados após o traumatismo crânio-encefálico e pode afetar de forma negativa seu desfecho. O objetivo do presente estudo foi analisar o polimorfismo -31C/T, localizado na região promotora do gene IL-1B, em pacientes com traumatismo crânio-encefálico grave visando correlacioná-lo com o desfecho primário precoce (alta do centro de terapia intensiva ou morte. MÉTODOS: Foram estudados 69 pacientes internados por traumatismo crânio-encefálico grave em três hospitais de Porto Alegre e região metropolitana. O polimorfismo foi analisado através da reação em cadeia da polimerase, seguida da digestão com enzima de restrição. RESULTADOS: O traumatismo crânio-encefálico grave foi associado a uma mortalidade de 45%. Não foram observadas diferenças significativas nas frequências alélicas e genotípicas entre os grupos de pacientes divididos pelo desfecho do traumatismo crânio-encefálico. CONCLUSÃO: Nossos resultados sugerem que o polimorfismo -31C/T do gene IL-1B não tem impacto significativo no desfecho fatal dos pacientes com traumatismo crânio-encefálico grave.OBJECTIVE: Traumatic brain injury is the major cause of death among individuals between 1-45 years-old. The outcome of traumatic brain injury may be related to brain susceptibility to the injury and genetic factors. Genes that may affect traumatic brain injury outcome are being

Contribution to study of effects consecutive to alpha decay of uranium 238 in some uranium compounds and uranium ores

International Nuclear Information System (INIS)

Ordonez-Regil, E.

1985-06-01

The consequences of alpha decay of 238 U in uranium compounds and in uranium bearing ores have been examined in two ways: leaching of 234 Th and determination of the activity ratio of 234 U and 238 U. The results have been interpreted mainly in terms of the ''hot'' character of the nascent 234 Th atoms [fr

Assesment of Plutonium 238 and Plutonium 239+240 in soils of different agricultural regions of Guatemala

International Nuclear Information System (INIS)

Gutierrez Martinez, E.A.

1998-02-01

In this report an assesment and measurement of PLUTONIUM 238, PLUTONIUM 239, and PLUTONIUM 240 are made. Samples of cultivated soils in 15 provinces of Guatemala were taken. To separate plutonium isotopes a radiochemical method was made using extraction, precipitation and ionic interchange. By electrodeposition the plutonium was measured using an alpha spectroscopy by PIPS method. The radioactivity ranges from 2.84 mBq/Kg to 36.38 mBq/Kg for plutonium 238, and 8.46 mBq/Kg to 26.61 mBq/Kg for plutonium 239+240

Charge-pickup of 238U at relativistic energies

International Nuclear Information System (INIS)

Rubehn, T.; Bassini, R.; Blaich, T.; Imme, G.; Iori, I.; Kunze, W.D.; Lindenstruth, V.; Lynen, U.; Moehlenkamp, T.; Moretto, L.G.; Ocker, B.; Pochodzalla, J.; Raciti, G.; Schuettauf, A.; Serfling, V.; Trautmann, W.; Trzcinski, A.; Verde, G.; Woerner, A.; Zude, E.; Zwieglinski, B.

1995-10-01

Cross sections for the charge-pickup of 238 U projectiles were measured at E/A=600 and 1000 MeV for seven different targets (Be, C, Al, Cu, In, Au and U). Events with two fission fragments with a sum charge of 93 in the exit channel were selected. Due to the significant excitation energy, the dominant part of produced Np nuclei fission instead of decaying to the ground state by evaporation. The observed cross sections can be well reproduced by intranuclear-cascade-plus-evaporation calculations and, therefore, confirm recent results that no exotic processes are needed to explain charge-pickup processes. (orig.)

Diet-gene interactions between dietary fat intake and common polymorphisms in determining lipid metabolism

Directory of Open Access Journals (Sweden)

Corella, Dolores

2009-03-01

-genotipo. Estas interacciones incluyen: la interacción entre el consumo de grasa total y el polimorfismo 514C/T en el promotor del gen de la lipasa hepática determinando las concentraciones de colesterol ligado a lipoproteínas de alta densidad (c-HDL; la interacción entre el consumo de ácidos grasos poliinsaturados y el polimorfismo 75G/A en el promotor del gen APOA1 en las concentraciones plasmáticas de c-HDL; la interacción entre los ácidos grasos poliinsaturados y el polimorfismo L162V en el gen PPARA determinando las concentraciones plasmáticas de triglicéridos y de apolipoproteína C-III; la interacción entre el polimorfismo 1131TC en el promotor del gen de la APOA5 determinando el metabolismo de los triglicéridos. Aunque se han publicado cientos de estudios dieta-genotipo en el ámbito del metabolismo lipídico, el nivel de evidencia científica todavía es bajo para realizar recomendaciones nutricionales a la población, por lo que se requiere mucha más investigación nutrigenética.

37 CFR 2.38 - Use by predecessor or by related companies.

Science.gov (United States)

2010-07-01

... TRADEMARK OFFICE, DEPARTMENT OF COMMERCE RULES OF PRACTICE IN TRADEMARK CASES The Written Application § 2.38... title or by a related company (sections 5 and 45 of the Act), and the use inures to the benefit of the... inures to the benefit of the applicant under section 5 of the Act, such facts must be indicated in the...

Uranium ("2"3"8U)-induced ROS and cell cycle perturbations, antioxidant responses and erythrocyte nuclear abnormalities in the freshwater iridescent shark fish Pangasius sutchi

International Nuclear Information System (INIS)

Annamalai, Sathesh Kumar; Arunachalam, Kantha Deivi

2017-01-01

Highlights: • Exposure to "2"3"8U deteriorated the antioxidant defenses like SOD, CAT and LPO. • Flow cytometric analysis revealed the increase in G2/M phase and S phase. • Micronucleus frequencies increased with Increased "2"3"8U exposure and time. • Exposure to waterborne "2"3"8U induces both chemical and radiotoxicity in P. sutchi. • ROS-mediated "2"3"8U toxic mechanism and the antioxidant responses has been proposed. - Abstract: The strategic plan of this study is to analyze any possible radiological impact on aquatic organisms from forthcoming uranium mining facilities around the Nagarjuna Sagar Dam in the future. The predominantly consumed and dominant fish species Pangasius sutchi, which is available year-round at Nagarjuna Sagar Dam, was selected for the study. To comprehend the outcome and to understand the mode of action of "2"3"8U, the fish species Pangasius sutchi was exposed to ¼ and ½ of the LC_5_0 doses of waterborne "2"3"8U in a static system in duplicate for 21 days. Blood and organs, including the gills, liver, brain and muscles, were collected at different time periods—0 h, 24 h, 48 h, 72 h, 96 h, 7, days 14 days and 21 days—using ICP-MS to determine the toxic effects of uranium and the accumulation of "2"3"8U concentrations. The bioaccumulation of "2"3"8U in P. sutchi tissues was dependent on exposure time and concentration. The accumulation of uranium was, in order of magnitude, measured as gills > liver > brain > tissue, with the highest accumulation in the gills. It was observed that exposure to "2"3"8U significantly reduced antioxidant enzymes such as superoxide dismutase, catalase, and lipid peroxidase. The analysis of DNA fragmentation by comet assay and cell viability by flow cytometry was performed at different time intervals. DNA histograms by flow cytometry analysis revealed an increase in the G2/M phase and the S phase. The long-term "2"3"8U exposure studies in fish showed increasing micronucleus frequencies in

Validation of the U-238 inelastic scattering neutron cross section through the EXCALIBUR dedicated experiment

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Leconte Pierre

2017-01-01

Full Text Available EXCALIBUR is an integral transmission experiment based on the fast neutron source produced by the bare highly enriched fast burst reactor CALIBAN, located in CEA/DAM Valduc (France. Two experimental campaigns have been performed, one using a sphere of diameter 17 cm and one using two cylinders of 17 cm diameter 9 cm height, both made of metallic Uranium 238. A set of 15 different dosimeters with specific threshold energies have been employed to provide information on the neutron flux attenuation as a function of incident energy. Measurements uncertainties are typically in the range of 0.5–3% (1σ. The analysis of these experiments is performed with the TRIPOLI4 continuous energy Monte Carlo code. A calculation benchmark with validated simplifications is defined in order to improve the statistical convergence under 2%. Various 238U evaluations have been tested: JEFF-3.1.1, ENDF/B-VII.1 and the IB36 evaluation from IAEA. A sensitivity analysis is presented to identify the contribution of each reaction cross section to the integral transmission rate. This feedback may be of interest for the international effort on 238U, through the CIELO project.

Validation of the U-238 inelastic scattering neutron cross section through the EXCALIBUR dedicated experiment

Science.gov (United States)

Leconte, Pierre; Bernard, David

2017-09-01

EXCALIBUR is an integral transmission experiment based on the fast neutron source produced by the bare highly enriched fast burst reactor CALIBAN, located in CEA/DAM Valduc (France). Two experimental campaigns have been performed, one using a sphere of diameter 17 cm and one using two cylinders of 17 cm diameter 9 cm height, both made of metallic Uranium 238. A set of 15 different dosimeters with specific threshold energies have been employed to provide information on the neutron flux attenuation as a function of incident energy. Measurements uncertainties are typically in the range of 0.5-3% (1σ). The analysis of these experiments is performed with the TRIPOLI4 continuous energy Monte Carlo code. A calculation benchmark with validated simplifications is defined in order to improve the statistical convergence under 2%. Various 238U evaluations have been tested: JEFF-3.1.1, ENDF/B-VII.1 and the IB36 evaluation from IAEA. A sensitivity analysis is presented to identify the contribution of each reaction cross section to the integral transmission rate. This feedback may be of interest for the international effort on 238U, through the CIELO project.

Censura y tolerancia del material sexualmente explícito: la opinión de los estudiantes universitarios de pregrado Pornography, Censureship, Internet, Students

Directory of Open Access Journals (Sweden)

2004-01-01

Full Text Available Objetivo: Conocer las opiniones de los estudiantes universitarios con relación a la censura del material sexualmente explícito. Se utilizó una encuesta de opinión en una muestra de 842 estudiantes de tres universidades peruanas. Resultados: 1 Las mujeres apoyan las leyes que prohíben completamente la pornografía, incluso en Internet, mientras que los varones respaldan las medidas reguladoras dirigidas a proteger a los menores de edad (p<0.05. 2 se confirmó la hipótesis de investigación: existe relación entre la opinión de los estudiantes universitarios, a favor de la libertad de información y su exposición actual a material sexualmente explícito (p<0.001. 3 el 28% de los estudiantes encuestados está a favor de la censura de las publicaciones, de ellos, un mayor porcentaje de mujeres mostró su conformidad <33.3% vs. 23.8%> (p=0.002. 4 La subescala "Censura/Rechazo" logró un alto nivel de confiabilidad (a=0.7961, mientras que en la subescala "Liberalidad" ésta fue algo más moderada (a=0.5312.

Database for 238U inelastic scattering cross section evaluation

International Nuclear Information System (INIS)

Kanda, Yukinori; Fujikawa, Noboru; Kawano, Toshihiko

1993-10-01

There are discrepancies among evaluated neutron inelastic scattering cross sections for 238 U in the evaluated nuclear data files, JENDL-3, ENDF/B-VI, JEF-2, BROND-2 and CENDL-2. Re-evaluating them is internationally being discussed to obtain the best outcome which can be accepted in common at the present by experts in the world. This report has been compiled to review the discrepancies among the evaluations in the present data files and to provide a common database for the re-evaluation work (author)

Isotope shift of 234U, 236U, 238U in U I

International Nuclear Information System (INIS)

Gagne, J.M.; Nguyen Van, S.; Saint-Dizier, J.P.; Pianarosa, P.

1976-01-01

New and very accurate data of isotope shifts and relative isotope shifts in 234 U, 236 U, 238 U are presented. The invariance of the relative isotope shift, for the transitions we have investigated, supports the hypothesis that the so called specific mass effect is negligible in uranium

Evaluation of daily intake of 238U and 232Th in a Korean mixed diet sample using RNAA

International Nuclear Information System (INIS)

Chung, Yong Sam; Moon, Jong Hwa; Kim, Sun Ha; Park, Kwang Won; Kang, Sang Hoon; Cho, Seung Yeon

2000-01-01

To estimate the degree of intake of 238 U and 232 Th through daily diet, a Korean mixed diet sample was prepared after the investigation of the amount of consumption of the daily diet which corresponds to the age of 20 to 60 years. For the analysis of U and Th, the RNAA method was applied. Two standard reference materials were used for quality control and assurance and the analytical results were compared with a certified value. The determination of U and Th in the Korean mixed diet sample was carried out under the same analytical conditions and procedures with SRM. It is found that the concentration of U and Th in a Korean mixed diet was about 35.4 ppb and 3.4 ppb. From these results, the daily intake of 238 U and 232 Th by diet is evaluated to be 6.98 and 0.67 μg per day, respectively. Radioactivities related to the intake of 238 U and 232 Th were estimated to be about 86 mBq per person per day and the annual dose equivalents from 238 U and 232 Th revealed as 3.18 μSv and 0.29 μSv per person, respectively

Investigation of fission properties and evaporation residue measurement in the reactions using 238U target nucleus

Directory of Open Access Journals (Sweden)

Saro S.

2011-10-01

Full Text Available Fragment mass distributions for fission after full momentum transfer were measured in the reactions of 30Si,34,36 S,31P,40Ar + 238U at bombarding energies around the Coulomb barrier. Mass distributions change significantly as a function of incident beam energy. The asymmetric fission probability increases at sub-barrier energy. The phenomenon is interpreted as an enhanced quasifission probability owing to orientation effects on fusion and/or quasifission. The evaporation residue (ER cross sections were measured in the reactions of 30Si + 238U and 34S + 238U to obtain information on fusion. In the latter reaction, significant suppression of fusion was implied. This suggests that fission events different from compound nucleus are included in the masssymmetric fragments. The results are supported by a model calculation based on a dynamical calculation using Langevin equation, in which the mass distribution for fusion-fission and quasifission fragments are separately determined.

Measurement of pair production cross sections in Ge for the 1. 238-3. 548 MeV energy range

Energy Technology Data Exchange (ETDEWEB)

Sharma, R K; Singh, K; Sahota, H S

1985-02-28

Pair production cross sections have been determined for the 1.238-3.548 MeV energy range in germanium (Z = 32) using a Ge(Li) gamma ray detector. The experimental results have been compared with the theoretical cross sections of previous workers. The results of the present measurements agree with the Bethe-Heitler results down to 1.771 MeV. However, at 1.238 MeV the experimental results are higher than all the theories.

TNF-α -238, -308, -863 polymorphisms, and brucellosis infection.

Science.gov (United States)

Eskandari-Nasab, Ebrahim; Moghadampour, Mehdi; Sepanj-Nia, Adel

2016-01-01

Brucella abortus is an intracellular bacterium that affects humans and domestic animals. Tumor necrosis factor-alpha (TNF-α) has been shown as a key player in the induction of cell-mediated resistance against Brucella infection. We aimed to evaluate the possible influence of the TNF-α promoter polymorphisms (-308 G/A, -238 G/A, and -863 C/A) on the susceptibility of human brucellosis. A total of 153 patients with active brucellosis and 128 healthy individuals were recruited. All subjects were genotyped for the polymorphisms in the TNF-α gene by Allele-Specific polymerase chain reaction analysis. Our results showed that the TNF-α -308 GG genotype was significantly more frequently present in controls than in brucellosis patients (91% vs. 75%), thus was a protective factor against developing brucellosis (OR=0.313, p=0.001). In contrast, the -308 GA genotype (OR=3.026, p=0.002) and minor allele (A) (OR=3.058, p=0.001) as well as AAG haplotype (OR=4.014, p=0.001) conferred an increased risk of brucellosis. However, the -238 G/A and -863 C/A polymorphisms were not associated with the risk of brucellosis at both allelic and genotypic levels (p>0.05). Our study revealed that the TNF-α -308 A allele or GA heterozygosity or AAG haplotype were associated with an increased risk of brucellosis in our population. Copyright © 2015 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Measurement of nuclide cross-sections of spallation residues in 1 A GeV 238U + proton collisions

International Nuclear Information System (INIS)

Taieb, J.; Tassan-Got, L.; Bernas, M.; Mustapha, B.; Rejmund, F.; Stephan, C.; Schmidt, K.H.; Armbruster, P.; Benlliure, J.; Enqvist, T.; Boudard, A.; Legrain, R.; Leray, S.; Volant, C.; Wlazlo, W.; Casarejos, E.; Czajkowski, S.; Pravikoff, M.

2003-02-01

The production of heavy nuclides from the spallation-evaporation reaction of 238 U induced by 1 GeV protons was studied in inverse kinematics. The evaporation residues from tungsten to uranium were identified in-flight in mass and atomic number. Their production cross-sections and their momentum distributions were determined. The data are compared with empirical systematics. A comparison with previous results from the spallation of 208 Pb and 197 Au reveals the strong influence of fission in the spallation of 238 U. (orig.)

The enigma of the ν=2+3/8 fractional quantum Hall effect

DEFF Research Database (Denmark)

Hutasoit, Jimmy; nrc762, nrc762; Mukherjee, Sutirtha

2017-01-01

The fractional quantum Hall effect at ν=2+3/8, which has been definitively observed, is one of the last fractions for which no viable explanation has so far been demonstrated. Our detailed study suggests that it belongs to a new class of exotic states described by the Bonderson-Slingerland wave...

49 CFR 238.15 - Movement of passenger equipment with power brake defects.

Science.gov (United States)

2010-10-01

... brakes; (C) Piston travel that is in excess of the Class I brake test limits required in § 238.313 but... where the necessary repairs can be made. (3) Commuter, short-distance intercity, and short-distance Tier... brakes. Commuter, short-distance intercity, and short-distance Tier II passenger trains which develop...

Activation Doppler Measurements on U 238 and U 235 in Some Fast Reactor Spectra

Energy Technology Data Exchange (ETDEWEB)

Tiren, L I; Gustafsson, I

1968-03-15

Measurements of the Doppler effect in U-238 capture and U-235 fission have been made by means of the activation technique in three different neutron spectra in the fast critical assembly FR0. The experiments involved the irradiation of thin uranium metal foils or oxide disks, which were heated in a small oven located at the core centre. The measurements on U-238 were extended to 1780 deg K and on U-235 to 1470 deg K. A core region surrounding the oven was homogenized in order to facilitate the interpretation of results. The reaction rates in the uranium samples were detected by gamma counting. The experimental method was checked with regard to systematic errors by irradiations in a thermal spectrum. The data obtained for U-238 capture were corrected for the effect of neutron collisions in the oven wall, and were extrapolated to zero sample thickness. In the softest spectrum (core 5) a Doppler effect (relative increase in capture rate) of 0.260 {+-} 0.018 was obtained on heating from 343 to 1780 deg K, and in the hardest spectrum (core 3) the corresponding value was 0.030 {+-} 0.003. An appreciable Doppler effect in U-235 fission was obtained only in the softest spectrum, in which the measured increase in fission rate on heating from 320 to 1470 deg K was 0.007 {+-} 0.003.

234U/238U activity ratio in groundwater - an indicator of past hydrogeological processes

International Nuclear Information System (INIS)

Rasilainen, K.; Suksi, J.; Marcos, N.; Nordman, H.

2005-01-01

In this report we describe the long-term behaviour of the uranium isotopes, U-234 and U-238 in groundwater systems. U is a redox sensitive element what for its behaviour is largely controlled by changes in the environmental conditions. A striking feature in U isotope geochemistry is seemingly different behaviour of U-238 and U-234. U isotopes fractionate at the rock-groundwater interface depending on chemical and radiological factors. Changes of the redox conditions in groundwater may thus affect the behaviour of U and its isotopes resulting in variable U concentration and U-234/U-238 activity ratios (AR). We examined the formation of ARs in different groundwater types from a geochemical and a physical/radiological point of view. It was envisaged that AR in groundwater is the consequence of radiological, chemical and hydrological processes. Groundwater condition (redox, flow, etc.) play a very important role in controlling the mass flow of U isotopes. Quantitative α-recoil modelling showed that α-recoil induced flux can be considered insignificant in cases of high-flow. This was an important finding because the exclusion of direct a-recoil means that it is groundwater chemistry and its variations which controls the U-234 mass flow and the formation of AR. Therefore, AR values could be used more confidently to indicate past redox changes and possibly flow paths. (orig.)

Measurement of the 238U subthreshold fission cross section for incident neutron energies between 0.6 and 100 keV

International Nuclear Information System (INIS)

Difilippo, F.C.; Perez, R.B.; de Saussure, G.; Olsen, D.K.; Ingle, R.W.

1977-01-01

The neutron-induced 238 U subthreshold fission cross section has been measured in the neutron energy range between 0.6 and 100 keV. A total of 28 fission clusters were identified. The well-known clusters at 721 and 1210 eV appeared resolved into their Class I components. Average 238 U subthreshold fission cross sections were determined and compared with available results in the literature. The measurement is interpreted in terms of fission doorway (Class II levels) arising from the assumption of the existence of a double-humped fission barrier for the ( 238 U + n) compound nucleus at large deformations. On the basis of this model, several fission barrier parameters were determined

Polimorfismos dos genes do receptor de serotonina (5-HT2A e da catecol-O-metiltransferase (COMT: fatores desencadeantes da fibromialgia? Serotonin receptor (5-HT 2A and catechol-O-methyltransferase (COMT gene polymorphisms: Triggers of fibromyalgia?

Directory of Open Access Journals (Sweden)

Josie Budag Matsuda

2010-04-01

Full Text Available INTRODUÇÃO: A fibromialgia é uma síndrome reumática caracterizada por dor difusa e crônica associada a fadiga, insônia, ansiedade, depressão, perda de memória e tontura. Embora os mecanismos fisiológicos que controlam a fibromialgia não tenham sido estabelecidos, fatores neuroendócrinos, genéticos ou moleculares podem estar envolvidos. OBJETIVO: O objetivo do presente estudo foi caracterizar os polimorfismos dos genes do receptor de serotonina (5-HT2A e da catecolO-metiltransferase (COMT em pacientes brasileiros com fibromialgia, a fim de avaliar sua participação na etiologia da doença. MATERIAL E MÉTODOS: O DNA genômico extraído de 102 amostras de sangue (51 pacientes, 51 controles foi usado para a caracterização molecular dos polimorfismos dos genes 5-HT2A e COMT, por meio de PCR-RFLP. RESULTADOS: A análise molecular dos polimorfismos do gene 5-HT2A demonstrou frequências de 25,49% C/C, 49,02% T/C e 25,49% T/T, nos pacientes com fibromialgia, e 17,65% C/C, 62,74% T/C e 19,61% T/T, no grupo controle, não apresentando diferença significativa entre o grupo de pacientes e o grupo controle. Os polimorfismos do gene da COMT em pacientes com fibromialgia apresentaram uma frequência de 17,65% e 45,10% para os genótipos H/H e L/H, respectivamente. No grupo controle, as frequências foram de 29,42%, para H/H, e 60,78%, para L/H, sem diferença significativa entre ambos os grupos. Entretanto, houve diferença significativa na frequência do genótipo L/L em pacientes (37,25% e controles (9,8%, o que permitiu a diferenciação entre os dois grupos. CONCLUSÃO: A frequência do genótipo L/L foi maior nos pacientes com fibromialgia. Apesar de a fibromialgia envolver uma situação poligênica e fatores ambientais, o estudo molecular do SNP rs4680 do gene da COMT pode auxiliar a identificação de indivíduos suscetíveis.INTRODUCTION: Fibromyalgia is a rheumatic syndrome characterized by diffuse and chronic pain associated with

Neutron induced fission cross section ratios for /sup 232/Th, /sup 235,238/U, /sup 237/Np, and /sup 239/Pu from 1 to 400 MeV

Energy Technology Data Exchange (ETDEWEB)

Lisowski, P.W.; Ullmann, J.L.; Balestrini, S.J.; Carlson, A.D.; Wasson, O.A.; Hill, N.W.

1988-01-01

Time-of-flight measurements of neutron induced fission cross section ratios for /sup 232/Th, /sup 235,238/U, /sup 237/Np, and /sup 239/Pu, were performed using the WNR high intensity spallation neutron source located at Los Alamos National Laboratory. A multiple-plate gas ionization chamber located at a 20-m flight path was used to simultaneously measure the fission rate for all samples over the energy range from 1 to 400 MeV. Because the measurements were made with nearly identical neutron fluxes, we were able to cancel many systematic uncertainties present in previous measurements. This allows us to resolve discrepancies among different data sets. In addition, these are the first neutron-induced fission cross section values for most of the nuclei at energies above 30 MeV. 8 refs., 3 figs.

Effect of microdose distribution on chromosome aberration frequency in liver cells of the Chinese hamster following exposure to 239PuO2 or 238PuO2 particles

International Nuclear Information System (INIS)

Brooks, A.L.; Peters, R.F.; Retherford, J.C.

1974-01-01

Chinese hamsters were injected intravenously with 239 PuO 2 or 238 PuO 2 particles of known size or with 238 Pu citrate to determine the effect of particle size and specific activity on the frequency and distribution of chromosome damage in the liver. Three particle sizes were used in the 239 PuO 2 experiment: 0.15, 0.44, and 0.89 μm, and all animals were injected with a constant activity, 5 x 10 -4 muCi 239 Pu/gm body weight. The 238 PuO 2 was injected in three particle sizes, 0.17, 0.41, and 1.1 μm and at three activity levels. The 238 Pu citrate was injected at 5 x 10 -3 muCi 238 Pu/gm body weight. Hamsters injected with 239 PuO 2 were sacrificed at 15, 42, and 122 days after injection and those injected with either 238 PuO 2 or 238 Pu citrate were sacrificed 12 days after injection. The number of alpha tracks/star increased as a function of the particle size injected. A change in particle size with time was noted as smaller particles were aggregated into larger ones by the phagocytic action of Kupffer cells. Injection of 239 PuO 2 and 238 PuO 2 produced a distribution of chromosome damage which was non-poison in nature. 239 PuO 2 produced increased damage with increasing average dose with some cells containing a large number of aberrations, but there was relatively little particle size effect. Conversely, aberration frequencies after 238 PuO 2 injection were inversely related to particle size and no cells were seen with large amounts of damage. The 238 Pu citrate produced 6 x 10 -3 aberrations/cell/rad which was a higher rate than observed for 238 Pu particles. Risk for the production of cellular damage in the liver was greater per μCi following injection of either 238 Pu or 239 Pu citrate than it was following deposition of the same amount of 239 PuO 2 or 238 PuO 2 particles. (U.S.)

Aplicaciones de la genética molecular en la practica forense

Directory of Open Access Journals (Sweden)

Oscar F. Ramos M.

1993-10-01

Full Text Available Desde el desarrollo de las huellas digitales a finales del siglo XIX, la tipificación del ADN por VNTR, representa la innovación más poderosa que se haya desarrollado en las ciencias forenses durante el siglo XX. Con el descubrimiento en 1980 del polimorfismo del ADN en el genoma humano y con la subsecuente demostración de que tal hipervariabilidad esta ampliamente distribuida en los humanos, las ciencias forenses han reconocido el enorme potencial que ofrece la tipificación del ADN para la identificación de un individuo a partir de una muestra biológica dejada en la escena del crimen. La utilidad de la tipificación del ADN como herramienta forense recae no solo en su alto poder de discriminación entre los individuos de una población, sino también porque se pueden utilizar muchos materiales de origen biológico, en diferentes circunstancias, que de otra manera serian inútiles en las pruebas de tipificación tradicional. El debate actual sobre las pruebas de ADN pone de relieve la necesidad de imponer un mayor rigor ante las dificultades que aparecen cuando una tecnología científica bastante compleja se introduce como prueba ante un tribunal de justicia. Se discuten las ventajas y limitaciones sobre el uso del polimorfismo del ADN en la medicina forense. En Colombia se deben establecer criterios nacionales para que las pruebas forenses del ADN sirvan a los intereses de la justicia, bien sea para identificar a un criminal o para absolver a un inocente.

238U-230Th-226Ra radioactive disequilibria in the products from 1707 eruption of Fuji volcano, Japan

International Nuclear Information System (INIS)

Kurihara, Yuichi; Takahashi, Masaomi; Sato, Jun

2008-01-01

Time scale of magmatic processes in the 1707 eruptive activity of Fuji volcano, Japan, was estimated by the 238 U- 230 Th- 226 Ra disequilibria observed in the 1707 volcanic products. The activity ratios of 226 Ra/ 230 Th in the products were larger than unity, being enriched in 226 Ra relative to 230 Th. The decay-corrected 226 Ra/ 230 Th activity ratio to the time of the eruption versus 238 U/ 230 Th activity ratio diagram for the 1707 volcanic products showed a positive correlation, suggesting that the 238 U/ 230 Th- 226 Ra disequilibria occurred during the magma genesis of Fuji volcano. The 230 Th- 226 Ra disequilibria in the 1707 volcanic products suggested that the time scale from the magma genesis to the eruption, including the melting of the mantle wedge, magma storage and magmatic differentiation from basalt to andesite, was less than 8000 years. (author)

Resonance parameters of the 6.67-, 20.9-, and 36.8-eV levels in 238U

International Nuclear Information System (INIS)

Olsen, D.K.; de Saussure, G.; Perez, R.B.; Difilippo, F.C.

1976-01-01

The ENDF/B-IV 238 U cross sections (MAT-1262) yield an effective capture resonance integral in strongly self-shielded situations which is too high. This situation suggests that the ENDF/B capture widths for the first few s-wave levels may be too large. Recent ORELA measurements of transmission through 238 U have been analyzed with a multilevel formula to determine the parameters of the 6.67-, 20.9-, and 36.6-eV levels. These three levels provide 86 percent of the infinitely dilute capture resonance integral

Análisis de los polimorfismos de longitud de los fragmentos de restricción (RFLP) del gen ribosómico 18S RNA de nutria gigante de río Pteronura brasiliensis

OpenAIRE

J. Hernández; A. Acosta; A. Gutiérrez; M. Hoyos; A. Esguerra; D. Merizalde; J. Bernal; Genética Molecular Grupo de Investigación en

2001-01-01

La nutria gigante de río Pteronura brasiliensises un mamífero carnívoro de la familia Mustelidae, ala cual pertenecen también las tairas, las martas y los hurones. La nutria es considerada por elCITES como una especie vulnerable y por la IUCN como especie en peligro de extinción. Por estarazón, el Centro de Biología Molecular del Gimnasio Campestre inicio un proyecto de genética conservacionista que pretende proveer información utilizable para el análisis, tanto de la especieP. brasiliensisco...

Estimation of initial lung deposition of inhaled 238PuO2 in beagles

International Nuclear Information System (INIS)

Stevens, D.L.; Park, J.F.

1986-01-01

Studies to determine the life-span dose-effect relationship of inhaled 238 PuO 2 in dogs require an estimate of initial lung deposition (ILD) to calculate the radiation dose to several organs. Ideally, this estimate of ILD is obtained by a summation of plutonium body burden at death plus all the plutonium excreted during the life of the dog. However, the high costs of excreta collection and of plutonium analyses for all excreta from each dog made it necessary to approximate the ILD by other less expensive methods. These methods could introduce error into the estimate of ILD and, consequently, into the radiation dose calculation. The objective of this work was to evaluate the potential error for several methods of estimating ILD. Thirteen beagle dogs were given a single 5- to 30-min exposure to 238 PuO 2 aerosols, resulting in estimated ILD of 0.85 to 11.7 μCi of plutonium-238. Plutonium analyses of the tissues at death and of all excreta from these dogs were used for this evaluation. The estimate of ILD, obtained by summation of the plutonium body burden at death plus all the plutonium excreted, was compared to the estimated ILD obtained by the plutonium whole-body retention function for each dog, using all excreta data; the mean plutonium whole-body retention function for each dog, using all excreta data; the plutonium whole-body retention function for each dog, using partial excreta data; and a mean plutonium whole-body retention function for all dogs, using partial excreta data. 4 refs., 3 figs., 4 tabs

Recovery and purification of uranium-234 from aged plutonium-238

International Nuclear Information System (INIS)

Keister, P.L.; Figgins, P.W.; Watrous, R.M.

1978-01-01

The current production methods used to recover and purify uranium-234 from aged plutonium-238 at Mound Laboratory are presented. The three chemical separation steps are described in detail. In the initial separation step, the bulk of the plutonium is precipitated as the oxalate. Successively lower levels of plutonium are achieved by anion exchange in nitrate media and by anion exchange in chloride media. The procedures used to characterize and analyze the final U 3 O 8 are given

The Radiative Capture Cross-Section of U 238 for Fast Neutrons

International Nuclear Information System (INIS)

Broda, E.

1945-01-01

This report was written by E. Broda and D.H. Wilkinson at the Cavendish Laboratory (Cambridge) in January 1945 and is about the radiative capture cross-section of U238 for fast neutrons. The Chemical procedure and beta counting, the notes on the activation of the samples, the results and an appendix as well as a short introduction can be found in this report. (nowak)

The Radiative Capture Cross-Section of U 238 for Fast Neutrons

Energy Technology Data Exchange (ETDEWEB)

Broda, E.

1945-07-01

This report was written by E. Broda and D.H. Wilkinson at the Cavendish Laboratory (Cambridge) in January 1945 and is about the radiative capture cross-section of U238 for fast neutrons. The Chemical procedure and beta counting, the notes on the activation of the samples, the results and an appendix as well as a short introduction can be found in this report. (nowak)

Post-Irradiation Examination of 237Np Targets for 238Pu Production

Energy Technology Data Exchange (ETDEWEB)

Morris, Robert Noel [ORNL; Baldwin, Charles A [ORNL; Hobbs, Randy W [ORNL; Schmidlin, Joshua E [ORNL

2015-01-01

Oak Ridge National Laboratory is recovering the US ²³⁸Pu production capability and the first step in the process has been to evaluate the performance of a ²³⁷Np target cermet pellet encased in an aluminum clad. The process proceeded in 3 steps; the first step was to irradiate capsules of single pellets composed of NpO₂ and aluminum power to examine their shrinkage and gas release. These pellets were formed by compressing sintered NpO₂ and aluminum powder in a die at high pressure followed by sintering in a vacuum furnace. Three temperatures were chosen for sintering the solution precipitated NpO₂ power used for pellet fabrication. The second step was to irradiate partial targets composed of 8 pellets in a semi-prototypical arrangement at the two best performing sintering temperatures to determine which temperature gave a pellet that performed the best under the actual planned irradiation conditions. The third step was to irradiate ~50 pellets in an actual target configuration at design irradiation conditions to assess pellet shrinkage and gas release, target heat transfer, and dimensional stability. The higher sintering temperature appeared to offer the best performance after one cycle of irradiation by having the least shrinkage, thus keeping the heat transfer gap between the pellets and clad small minimizing the pellet operating temperature. The final result of the testing was a target that can meet the initial production goals, satisfy the reactor safety requirements, and can be fabricated in production quantities. The current focus of the program is to verify that the target can be remotely dissembled, the pellets dissolved, and the ²³⁸Pu recovered. Tests are being conducted to examine these concerns and to compare results to code predictions. Once the performance of the full length targets has been quantified, the pellet ²³⁷Np loading will be revisited to determine if it can be

Farmacogenética: importancia de la determinación del fenoticpo acetilador Pharmacogenitecs: importance of acetylating phenotype determination

Directory of Open Access Journals (Sweden)

Alvaro Perez Arcila

1994-02-01

Full Text Available

El campo de la investigación relacionado con las respuestas de base hereditaria a las drogas se ha denominado farmacogenética. Se han descrito al menos 60 polimorfismos farmacogenéticos en la medicina clínica; muchos de ellos son responsables de las marcadas diferencias en la predisposición gen ética para

desarrollar toxicidad por drogas O cáncer. En este momento los polimorfismos de mayor atención son los de la debrisoquina-esparteína y de la N-acetilación por el gran número de fármacos de prescripción común y de aminas carcinogénicas que utilizan estas enzimas para su inactivación.

Research concerning hereditary basis of response to drugs is known as pharmacogenetics; at least 60 pharmacogenetic polymorphisms have been described in clinical medicine; many of them are responsible for marked differences in predisposition towards drug toxicity or cancer. The debrisoquine.esparteine and the N-acetylation polymorphisms are presently the most important, since they involve both many frequently prescribed drugs, and carcinogenic amines that use this enzyme for inactivation.

Angular distribution of fragments from neutron-induced fission of 238U in the intermediate energy region

International Nuclear Information System (INIS)

Carlsson, Magnus

2004-06-01

Areas ranging from nuclear structure models to accelerator-driven systems benefit from improved neutron-induced fission data in the intermediate energy region. In this Master's degree thesis, the fragment angular distribution from fission of 238 U, induced by 21-MeV neutrons, has been analysed from an experiment performed with the Medley/DIFFICILE setup at the The Svedberg Laboratory in Uppsala. The data have been corrected for low energy neutrons in the beam. The results agree with other experiments, as well as with model calculations. The data should be a starting point for further analysis with a goal to deduce the fission cross-section of 238 U

Influence of soil texture on the distribution and availability of 238U, 230Th, and 226Ra in soils

International Nuclear Information System (INIS)

Blanco Rodriguez, P.; Vera Tome, F.; Lozano, J.C.; Perez-Fernandez, M.A.

2008-01-01

The influence of soil texture on the distribution and availability of 238 U, 230 Th, and 226 Ra in soils was studied in soil samples collected at a rehabilitated uranium mine located in the Extremadura region in south-west Spain. The activity concentration (Bq kg -1 ) in the soils ranged from 60 to 750 for 238 U, from 60 to 260 for 230 Th, and from 70 to 330 for 226 Ra. The radionuclide distribution was determined in three soil fractions: coarse sand (0.5-2 mm), medium-fine sand (0.067-0.5 mm), and silt and clay ( 238 U, 230 Th, and 226 Ra between the activity concentration per fraction and the total activity concentration in the bulk soil. Thus, from the determination of the activity concentration in the bulk soil, one could estimate the activity concentration in each fraction. Correlations were also found for 238 U and 226 Ra between the labile activity concentration in each fraction and the total activity concentration in bulk soil. Assuming that there is some particle-size fraction that predominates in the process of soil-to-plant transfer, the parameters obtained in this study should be used as correction factors for the transfer factors determined from the bulk soil in previous studies

New explanation for extreme u-234 u-238 disequilibria in a dolomitic aquifer

CSIR Research Space (South Africa)

Kronfeld, J

1994-05-01

Full Text Available High U-234/U-238 activity ratios are found in the shallow groundwater of the phreatic Transvaal Dolomite Aquifer. The aquifer is uranium poor, while the waters are oxygen rich and young. Tritium and C-14 are used to show that the disequilibrium...

Effect of nonaxial and hexadecapole deformation on the hyperfine splitting of energy levels in 238U muonic atoms

International Nuclear Information System (INIS)

Bagaev, V.I.; Mikhajlov, I.N.; Ortlepp, Kh.G.; Fromm, V.D.

1979-01-01

The effect of nonaxial and hexadecapole deformation on spectra of moun atoms is considered, the model of rigid nonaxial rotator being used. Experimental data on μ -238 U obtained on the JINR synchrocyclotron are presented. The effect of monopolar, quadrupolar and hexadecapolar parts of potential on muon spectrum is studied using a separated beam of negative 105 MeV/c muons, as the contribution of other harmonics is negligible. Wave functions of 238 U nucleus are determined in the framework of the Davydov-Filipov model. The values of charge distribution parameters obtained for 238 U are compared with available ones. The comparison shows that the effect of nuclear polarization on quadrupolar splitting of n→n-1 transitions decreases with the growth of n. Quadrupolar splitting of 4F→3D transitions is sufficiently large for experimental studies. Besides, vacuum polarization, radial charge distribution etc. produce an insignificant effect on the above transitions

Gastrointestinal absorption and retention of plutonium-238 in neonatal rats and swine

International Nuclear Information System (INIS)

Sullivan, M.F.

1978-01-01

Neonatal rats gavaged with 237 Pu or 238 Pu retained a substantial quantity in gut mucosa for a week but absorbed only 2.9% of the 237 Pu. After 140 days the amount retained fell to half that initially deposited. Newborn swine also retained large amounts in the gut and absorbed about 40% of the dose

Resolved resonance parameters for uranium 238 from 4 to 6 keV

International Nuclear Information System (INIS)

Olsen, D.K.; Meszaros, P.S.

1982-01-01

Neutron widths for 145 resonances from 4 to 6 keV are reported from a least-squares shape analysis of the ORELA 150-m, 4-sample 238 U transmission data. The resultant s-wave strength function from 4 to 6 keV is found to be substantially smaller than that from 0 to 4 keV

Final report on production of Pu-238 in commercial power reactors: target fabrication, postirradiation examination, and plutonium and neptunium recovery

International Nuclear Information System (INIS)

Pobereskin, M.; Langendorfer, W.; Lowry, L.; Farmelo, D.; Scotti, V.; Kruger, O.

1975-01-01

Considerable interest has been generated in more extensive applications of radioisotope thermoelectric generator (RTG) systems. This raises questions concerning the availability of 238 Pu to supply an expanding demand. The development of much of this demand will depend upon a considerable reduction in cost of 238 Pu. Two neptunia--zirconia--fuel target rods, containing four sections each of different NpO 2 concentrations, were irradiated in the Connecticut Yankee Reactor for approximately one year. Following irradiation both target rods were subjected to nondestructive examination. One rod was chosen for destructive testing and analysis. Post-irradiation chemical analyses included total Pu and Np, ppM 236 Pu/ 238 Pu, and Pu isotopic abundance. The results of these analyses and of electron microprobe analysis which provided the relative Pu concentration across the pellet diameters are tabulated. It was concluded that the feasibility of all operations involved in the production of 238 Pu by irradiation of 237 NpO 2 targets in commercial nuclear power reactors was demonstrated and that the demonstration should be extended to a pilot-scale leading to installation of a full production capacity. (U.S.)

Measurement of Fragment Mass Distributions in Neutron-induced Fission of {sup 238}U and {sup 232}Th at Intermediate Energies

Energy Technology Data Exchange (ETDEWEB)

Simutkin, V.D. [Uppsala University, P.O Box 525, SE-751 20 Uppsala (Sweden)

2008-07-01

Conceptual analysis of accelerator-driven systems assumes extensive use of nuclear data on neutron-induced reactions at intermediate energies. In particular, information about the fission fragment yields from the {sup 238}U(n,f) and {sup 232}Th(n,f) reactions is of particular interest at neutron energies from 10 to 200 MeV. However, there is a lack of such data for both {sup 238}U and {sup 232}Th. Up to now, the intermediate energy measurements have been performed for {sup 238}U only, and there are no data for the {sup 232}Th(n,f) reaction. The aim of the work is to provide such data. Fission fragment mass distributions for the {sup 232}Th(n,f) and {sup 238}U(n,f) reactions have been measured for the incident neutron energies 32.8 MeV, 45.3 MeV and 59.9 MeV. The experiments have been performed at the neutron beam facility of the Universite Catholique de Louvain, Belgium. A multi-section Frisch-gridded ionization chamber has been used as a fission fragment detector. The data obtained have been interpreted in terms of the multimodal random neck-rupture model (MMRNRM). (authors)

U-234/U-238 ratio: Qualitative estimate of groundwater flow in Rocky Flats monitoring wells

International Nuclear Information System (INIS)

Laul, J.C.

1994-01-01

Groundwater movement through various pathways is the primary mechanism for the transport of radionuclides and trace elements in a water/rock interaction. About three dozen wells, installed in the Rocky Flats Plant (RFP) Solar Evaporation Ponds (SEP) area, are monitored quarterly to evaluate the extent of any lateral and downgradient migration of contaminants from the Solar Evaporation Ponds: 207-A; 207-B North, 207-B Center, and 207-B South; and 207-C. The Solar Ponds are the main source for the various contaminants: radionuclides (U-238, U-234, Pu-239, 240 and Am-241); anions; and trace metals to groundwaters. The U-238 concentrations in Rocky Flats groundwaters vary from 2 (CO 3 ) 2 2- , because of the predominant bicarbonate medium

The evaluation for reference fission yield of 238U fission

International Nuclear Information System (INIS)

Liang Qichang; Liu Tingjin

1998-01-01

In the fission yield data evaluation and measurement, the reference yield is very important, good or poor recommended or measurement values depend upon the reference data to a great extent. According to the CRP's requirement, the evaluation of reference fission yields have been and will be carried out in CNDC, as a part of the whole work (contract No.9504/R 0 /Regular Budget Fund), the evaluation for 29 reference fission yields of 15 product nuclides from 238 U fission have been completed

A statistical study of {sup 238}U and {sup 234}U/{sup 238}U distributions in coral samples from the Egyptian shoreline of the north-western Red sea and in fossil mollusk shells from the Atlantic coast of High Atlas in Morocco: implications for {sup 230}Th/{sup 234}U dating

Energy Technology Data Exchange (ETDEWEB)

Choukri, A.; Hakam, O.K. [Lab. des Faibles Radioactivites et d' Environnements, UFR: Faibles Radioactivites, Mathematiques physiques et environnement, Kenitra (Morocco); Reyss, J.L. [Lab. des Sciences de Climat et de l' Environnement, Domaine du CNRS, Gif sur Yvette (France); Plaziat, J.C. [Univ. de Paris-Sud, Dept. des Sciences de la Terre, Orsay (France)

2002-07-01

In this work, radiochemical analysis results of 126 uncrystallized coral samples from the Egyptian shoreline of northwestern Red Sea and 120 fossil mollusk shell samples from the Atlantic coast of Moroccan High Atlas at the North of Agadir City in Morocco are presented and discussed. The coral samples were collected in Egypt from the emerged coral reef terraces over 500 km from The Ras Gharib-Ras Shukeir depression (28 10') in the north to Wadi Lahami (north of Ras Banas, 24 10') in the south. The fossil mollusk shells were collected in Morocco from Agadir-Harbour in the south to Tamri village in the north extending over about 50 km. The statistical distributions of results ({sup 238}U content, {sup 234}U/{sup 238}U activity ratio and ages) obtained on the dated materials in the two different regions were compared for three fossil sea levels corresponding to three different climatic stages (Holocene, 5e, 7 and/or 9) in the aim to establish methodological criteria for judging validity of the measured ages. For corals, {sup 238}U content varies in narrow interval around the same average value of 3 ppm for the three sea levels, the calculated initial {sup 234}U/{sup 238}U values are in agreement with the actual sea water ratio (1.15) with some values slightly higher than for the older sea levels. The obtained ages are in good agreement with the ages reported previously for the three emerged fossil sea levels on unrecrystallized corals by alpha spectrometry and by mass spectrometry. For mollusk shells, except for Holocene sea level, {sup 238}U and initial {sup 234}U/{sup 238}U activity ratios vary for the older levels in wide intervals, independent of species and calcite contents of samples. The high {sup 238}U contents and {sup 234}U/{sup 238}U activity ratio are due eventually to a post-incorporation of secondary uranium from sea water or from continental waters drained away rivers. This incorporation leads to a rejuvenation of mollusk shell ages and is

232-Th and 238-U radioactive contaminations of sediments along the South China Sea of East Coast Peninsular Malaysia by INAA

International Nuclear Information System (INIS)

Khadijeh Rezaee Ebrahim Saraee; Elias Saion; Naghavi, K.

2009-01-01

The concentrations of 232 Th and 238 U were determined in 30 sediment samples, collected from the South China Sea bed of the east coast peninsular Malaysia. The samples were dried in an oven for 10 days at 65 C and stored in polyethylene bottles for future analysis. INAA used to analyse surficial sediments. The 232 Th and 238 U activities in surficial sediments determined. These activities increased from 14.02 to 30.17 Bq Kg -1 and from 47.49 to 113.69 Bq Kg -1 for 232 Th and 238 U , respectively. Results show diffuse distribution of 232 Th and 238 U actinides in studied area. The Th/Sc and U/Sc ratios of the suricial sediments have same distribution and the highest their values are in station EC12. The radioactive contamination of the investigated sector is compared with the results obtained of other coastal sediments of Malaysia. Results show activity contamination in coastal sediments of the South China Sea is lower than the Straits of Malacca and is the same with the Straits of Johor. (Author)

Investigation of the degree of equilibrium of the long-lived uranium-238 decay-chain members in airborne and bulk uranium-ore dusts

International Nuclear Information System (INIS)

Jackson, P.O.; Thomas, C.W.

1982-08-01

The degree of disequilibrium among 238 U decay chain members in some airborne dusts and typical ores has been established by precise radiochemical analyses. This information is necessary to evaluate the lung dose model currently used for estimating the effect of the inhalation of uranium ore dust. The particle size distributions of airborne decay chain components in dusts at one uranium mill have been investigated. Statistically significant disequilibria were observed for 230 Th, 226 Ra, and 210 Pb in both airborne dusts and composite ore samples. With the exception of ore from one mill in the United States, most of the daughter concentrations in powdered ore composites were within 10% of 238 U. In airborne dusts, the concentration of 226 Ra was typically below 238 U; the minimum 226 Ra concentration observed for airborne ore dusts was 56% of equilibrium. A statistically significant particle size dependence was observed for 226 Ra/ 238 U ratios in several airborne dusts collected at a uranium mill

New evaluation of 238U neutron resonance parameters

International Nuclear Information System (INIS)

Derrien, Herve; Leal, Luiz C.; Larson, Nancy M.

2003-01-01

The neutron resonance parameters of 238 U were obtained in the energy range 1 keV to 20 keV from a SAMMY Reich-Moore analysis of high resolution transmission measurements performed at ORELA. In the energy range 1 keV to 10 keV, the analysis used as prior values the ENDF/B-VI resonance parameters. The analysis in the energy range 10 keV to 20 keV resulted in the creation of a set of resonance parameters for the representation of the cross section in this energy range. The results are compared to the ENDF/B-VI evaluation. Some statistical properties of the new resonance parameters are examined. (author)

Reaction and fission cross-sections of 750AMeV 238U ions on Pb, Cu and AI-targets

International Nuclear Information System (INIS)

Hesse, M.; Aumann, T.; Czajkowski, S.; Dessagne, P.; Hanelt, E.; Kozhuharov, C.; Miehe, C.; Pfuetzner, M.; Roehl, C.; Schwab, W.; Stephan, C.; Tassan-Got, L.

1995-09-01

Charge-loss and fission cross-sections of 238 U at 750 A.MeV were measured on Al, Cu and Pb targets. The charge-loss rate was obtained by the attenuation method. Fission was selected by detecting the pair of highly ionizing fragments. Since the neutron-loss cross sections were measured in a parallel experiment for the same projectiles, all cross sections contributing to 238 U collisions on nuclei are available now as function of the target mass number and can be compared with current models. (orig.)

An alternative route for the preparation of the medical isotope 99Mo from the 238U(γ, f) and 100Mo(γ, n) reactions

International Nuclear Information System (INIS)

Naik, H.; Goswami, A.; Suryanarayana, S.V.; Jagadeesan, K.C.; Thakare, S.V.; Joshi, P.V.; Nimje, V.T.; Mittal, K.C.; Venugopal, V.; Kailas, S.

2013-01-01

The radionuclide 99 Mo, which has a half-life of 65.94 h was produced from 238 U(γ, f) and 100 Mo(γ, n) reactions using a 10 MeV electron linac at EBC, Kharghar Navi-Mumbai, India. This has been investigated since the daughter product 99m Tc is very important from a medical point of view and can be produced in a generator from the parent 99 Mo. The activity of 99 Mo was analyzed by a γ-ray spectrometric technique using a HPGe detector. From the detected γ-rays activity of 140.5 and 739.8 keV, the amount of 99 Mo produced was determined. For comparison, the amount of 99 Mo from 238 U(γ, f) and 100 Mo(γ, n) reactions was also estimated using the experimental photon flux from 197 Au(γ, n) 196 Au reaction. The amount of 99 Mo from the detected γ-lines is in agreement with the estimated value for 238 U(γ, f) and 100 Mo(γ, n) reactions. The production of 99 Mo activity from 238 U(γ, f) and 100 Mo(γ, n) reactions is a relevant and novel approach, which provides alternative routes to 235,238 U(n, f) and 98 Mo(n, γ) reactions, circumventing the need for a reactor. The viability and practicality of the 99 Mo production from the 238 U(γ, f) and 100 Mo(γ, n) reactions alternative to 235,238 U(n, f) and 98 Mo(n, γ) reactions has been emphasize. An estimate has been also arrived based on the experimental data of present work to fulfill the requirement of DOE. (author)

Evaluation of the 238U neutron total cross section

International Nuclear Information System (INIS)

Smith, A.; Poenitz, W.P.; Howerton, R.J.

1982-12-01

Experimental energy-averaged neutron total cross sections of 238 U were evaluated from 0.044 to 20.0 MeV using regorous numerical methods. The evaluated results are presented together with the associated uncertainties and correlation matrix. They indicate that this energy-averaged neutron total cross section is known to better than 1% over wide energy regions. There are somwewhat larger uncertainties at low energies (e.g., less than or equal to 0.2 MeV), near 8 MeV and above 15 MeV. The present evaluation is compard with values given in ENDF/B-V

Identificación de marcadores microsatelites para el estudio de la diversidad genética de Taenia solium

OpenAIRE

Eguiluz Moya, María Lisseth

2014-01-01

La diversidad genética en parásitos está orientada hacia el esclarecimiento de la epidemiología y transmisión de las enfermedades. Muchos aspectos de la variación genética de Taenia solium se mantienen aún desconocidos. El estudio de la variación genética de este parásito permitiría comprender las diferencias observadas en la infectividad, patogenicidad y respuesta al tratamiento contra la neurocisticercosis. El polimorfismo de los loci microsatélites es un método utilizado ampliamente para e...

Origen, dispersión y diversidad del chirimoyo (Annona cherimola Mill.) en el continente americano

OpenAIRE

Larrañaga González, Nerea

2017-01-01

En este trabajo se ha profundizado en las razones que pueden explicar la distribución actual de la diversidad genética del chirimoyo (Annona cherimola Mill.), una especie frutal adaptada a climas subtropicales, con claras implicaciones para su uso y conservación. Gracias a un estudio de código de barras, se pudo comprobar el poder de discriminación del gen cloroplastídico maturasa K (matK) entre las especies con mayor importancia agronómica del género. Además, sobre los polimorfismos de nucle...

Casos estandarizados en reumatología. Enfermedades autoinmunes sistémicas

OpenAIRE

Nolla Solé, Joan Miquel

2014-01-01

Introducción. Las enfermedades autoinmunes sistémicas, denominadas también colagenosis o conectivopatías, constituyen una heterogéneo grupo de procesos que presentan en común: los fenómenos de autoinmunidad, que tienen valor patogénico y, en muchas ocasiones, diagnóstico y que posibilitan la definición de subgrupos pronósticos y terapéuticos, así como la afección simultánea de diversos órganos y sistemas corporales, circunstancia que confiere a las entidades un gran polimorfismo clínico ...

Ambient air sampling for radioactive air contaminants at Los Alamos National Laboratory: A large research and development facility

International Nuclear Information System (INIS)

Eberhart, C.F.

1998-01-01

This paper describes the ambient air sampling program for collection, analysis, and reporting of radioactive air contaminants in and around Los Alamos National Laboratory (LANL). Particulate matter and water vapor are sampled continuously at more than 50 sites. These samples are collected every two weeks and then analyzed for tritium, and gross alpha, gross beta, and gamma ray radiation. The alpha, beta, and gamma measurements are used to detect unexpected radionuclide releases. Quarterly composites are analyzed for isotopes of uranium ( 234 U, 235 U, 238 U), plutonium ( 238 Pu, 239/249 Pu), and americium ( 241 Am). All of the data is stored in a relational database with hard copies as the official records. Data used to determine environmental concentrations are validated and verified before being used in any calculations. This evaluation demonstrates that the sampling and analysis process can detect tritium, uranium, plutonium, and americium at levels much less than one percent of the public dose limit of 10 millirems. The isotopic results also indicate that, except for tritium, off-site concentrations of radionuclides potentially released from LANL are similar to typical background measurements

Radionuclide contaminant analysis of small mammals at Area G, TA-54, Los Alamos National Laboratory, 1995

International Nuclear Information System (INIS)

Bennett, K.; Biggs, J.; Fresquez, P.

1997-01-01

At Los Alamos National Laboratory, small mammals were sampled at two waste burial sites (Site 1-recently disturbed and Site 2-partially disturbed) at Area G, Technical Area 54 and a control site on Frijoles Mesa (Site 4) in 1995. Our objectives were (1) to identify radionuclides that are present within surface and subsurface soils at waste burial sites, (2) to compare the amount of radionuclide uptake by small mammals at waste burial sites to a control site, and (3) to identify if the primary mode of contamination to small mammals is by surface contact or ingestion/inhalation. Three composite samples of at least rive animals per sample were collected at each site. Pelts and carcasses of each animal were separated and analyzed independently. Samples were analyzed for 241 Am, 90 Sr , 238 Pu, 239 Pu, total U, 137 Cs, and 3 H. Significantly higher (parametric West at p=0.05) levels of total U, 241 Am, 238 Pu and 239 Pu were detected in pelts than in carcasses of small mammals at TA-54. Concentrations of other measured radionuclides in carcasses were nearly equal to or exceeded the mean concentrations in the pelts. Our results show higher concentrations in pelts compared to carcasses, which is similar to what has been found at waste burial/contaminated sites outside of Los Alamos National Laboratory. Site 1 had a significantly higher (alpha=0.05, P=0.0125) mean tritium concentration in carcasses than Site 2 or Site 4. In addition Site 1 also had a significantly higher (alpha=0.05, p=0.0024) mean tritium concentration in pelts than Site 2 or Site 4. Site 2 had a significantly higher (alpha=0.05, P=0.0499) mean 239 Pu concentration in carcasses than either Site 1 or Site 4

Radionuclide concentrations in vegetation at the Los Alamos National Laboratory in 1998

International Nuclear Information System (INIS)

Gonzales, G.J.; Fresquez, P.R.; Mullen, M.A.; Naranjo, L. Jr.

2000-01-01

This report summarizes and evaluates the concentrations of 3 H, 137 Cs, 238 Pu, 239,240 Pu, 241 Am, 90 Sr, and total U in understory and overstory vegetation collected from Los Alamos National Laboratory (LANL), its perimeter, and regional background areas in 1998. Comparisons to conservative toxicity reference value safe limits were also made. The arithmetic mean LANL radionuclide concentrations in understory were 501 pCi L -1 for 3 H, 0.581 pCi ash g -1 for 137 Cs, 0.001 pCi ash g -1 for 238 Pu, 0.008 pCi ash g -1 for 239,240 Pu, 0.007 pCi ash g -1 for 241 Am, 1.46 pCi ash g -1 for 90 Sr, and 0.233 microg ash g -1 for total uranium. The mean LANL radionuclide concentrations in overstory were 463 pCi L -1 for 3 H, 1.51 pCi ash g -1 for 137 Cs, 0.0004 pCi ash g -1 238 Pu, 0.008 pCi ash g -1 for 239,240 Pu, 0.014 pCi ash g -1 for 241 Am, 1.97 pCi ash g -1 for 90 Sr, and 0.388 microg ash g -1 for total uranium. Concentrations of radionuclides and total U in both understory and overstory vegetation at LANL generally were not statistically higher than in perimeter and regional background vegetation (α = 0.05). The exceptions were LANL 3 H > perimeter 3 H (understory) and LANL 3 H background 3 H (overstory). All maximum radionuclide concentrations were lower than toxicity reference values. With the exception of total U, the relationship between contaminant concentration in soil vs. vegetation was insignificant (α = 0.05). Generally, as the concentration of total U in soil decreased, the concentration in vegetation increased. This held true for both understory and overstory and regardless of whether data were separated by general location (LANL, perimeter, and background) or not. There was no apparent relationship between contaminant concentrations in understory vs. overstory

Environmental 238U and 232Th concentration measurements in an area of high level natural background radiation at Palong, Johor, Malaysia.

Science.gov (United States)

Ramli, A Termizi; Hussein, A Wahab M A; Wood, A Khalik

2005-01-01

Concentrations of uranium-238 and thorium-232 in soil, water, grass, moss and oil-palm fruit samples collected from an area of high background radiation were determined using neutron activation analysis (NAA). U-238 concentration in soil ranged from 4.9 mg kg(-1) (58.8 Bq kg(-1)) to 40.4 mg kg(-1) (484.8 Bq kg(-1)), Th-232 concentration ranged from 14.9 mg kg(-1) (59.6 Bq kg(-1)) to 301.0 mg kg(-1) (1204 Bq kg(-1)). The concentration of U-238 in grass samples ranged from below the detection limit to 0.076 mg kg(-1) (912 mBq kg(-1)), and Th-232 ranged from 0.008 mg kg(-1) (32 mBq kg(-1)) to 0.343 mg kg(-1) (1.372 Bq kg(-1)). U-238 content in water samples ranged from 0.33 mg kg(-1) (4.0 Bq L(-1)) to 1.40 mg kg(-1) (16.8 Bq L(-1)), and Th-232 ranged from 0.19 mg kg(-1) (0.76 Bq L(-1)) to 0.66 mg kg(-1) (2.64 Bq L(-1)). It can be said that the concentrations of environmental U-238 and Th-232 in grass and water samples in the study area are insignificant. Mosses were found to be possible bio-radiological indicators due to their high absorption of the heavy radioelements from the environment.

Origin of the {sup 238}U-{sup 230}Th disequilibrium in magmas from subduction zones: the Arenal example; Origine du desequilibre {sup 238}U-{sup 230}TH dans les magmas des zones de subduction: exemple de l`Arenal

Energy Technology Data Exchange (ETDEWEB)

Villemant, B [Paris-6 Univ., 75 (France)

1997-12-31

The existence in some volcanic products of strong excess of {sup 238}U with respect to {sup 230}Th is one of the characteristics of volcanic arc magmas. These excesses are generally attributed to fluid additions inside mantellic sources before magma segregation, differentiation and eruption. These fluids should be linked to the dehydration of the subducted rocks. These hypotheses are essentially based on correlations between {sup 10}Be, {sup 87}Sr anomalies, Ba/La ratios and on the distribution of volcanic centers with respect to the subduction zone. Recent studies suggest an evolution of the composition of volcanic sources in Central America from a depleted mantle type (MORB) in the North (Nicaragua) to a less transformed enriched type (OIB) in the South (Costa Rica). The Arenal volcano belongs to a transition zone between these two types. The preliminary study of trace elements and {sup 238}U-{sup 230}Th disequilibria in recent volcanic products (1968-1993) indicates a more complex situation. At least two different mantle sources were successively involved characterized by different Th/La and La/Yb ratios and very different to the OIB type. Also most lavas are in equilibrium with {sup 238}U/{sup 232}Th ratios of about 1.2 to 1.3. However, in eruptive cycle, some lavas are characterized by a strong {sup 238}U excess with respect to {sup 230}Th with cannot be linked to the sources, even when modified by fluids in depth. These results are interpreted in terms of heterogeneities of mantle sources and low depths late interactions with hydrothermal fluids during eruptions. Abstract only. (J.S.). 2 refs.

Origin of the {sup 238}U-{sup 230}Th disequilibrium in magmas from subduction zones: the Arenal example; Origine du desequilibre {sup 238}U-{sup 230}TH dans les magmas des zones de subduction: exemple de l`Arenal

Energy Technology Data Exchange (ETDEWEB)

Villemant, B. [Paris-6 Univ., 75 (France)

1996-12-31

The existence in some volcanic products of strong excess of {sup 238}U with respect to {sup 230}Th is one of the characteristics of volcanic arc magmas. These excesses are generally attributed to fluid additions inside mantellic sources before magma segregation, differentiation and eruption. These fluids should be linked to the dehydration of the subducted rocks. These hypotheses are essentially based on correlations between {sup 10}Be, {sup 87}Sr anomalies, Ba/La ratios and on the distribution of volcanic centers with respect to the subduction zone. Recent studies suggest an evolution of the composition of volcanic sources in Central America from a depleted mantle type (MORB) in the North (Nicaragua) to a less transformed enriched type (OIB) in the South (Costa Rica). The Arenal volcano belongs to a transition zone between these two types. The preliminary study of trace elements and {sup 238}U-{sup 230}Th disequilibria in recent volcanic products (1968-1993) indicates a more complex situation. At least two different mantle sources were successively involved characterized by different Th/La and La/Yb ratios and very different to the OIB type. Also most lavas are in equilibrium with {sup 238}U/{sup 232}Th ratios of about 1.2 to 1.3. However, in eruptive cycle, some lavas are characterized by a strong {sup 238}U excess with respect to {sup 230}Th with cannot be linked to the sources, even when modified by fluids in depth. These results are interpreted in terms of heterogeneities of mantle sources and low depths late interactions with hydrothermal fluids during eruptions. Abstract only. (J.S.). 2 refs.

Neutron inelastic-scattering cross sections of 232Th, 233U, 235U, 238U, 239Pu and 240Pu

International Nuclear Information System (INIS)

Smith, A.B.; Guenther, P.T.

1982-01-01

Differential-neutron-emission cross sections of 232 Th, 233 U, 235 U, 238 U, 239 Pu and 240 Pu are measured between approx. = 1.0 and 3.5 MeV with the angle and magnitude detail needed to provide angle-integrated emission cross sections to approx. 232 Th, 233 U, 235 U and 238 U inelastic-scattering values, poor agreement is observed for 240 Pu, and a serious discrepancy exists in the case of 239 Pu

Los niños y los videojuegos

OpenAIRE

Orrego Gaviria, Jaime; Fundación Valle de Lili

2007-01-01

Los niños y los videojuegos / Efectos perjudiciales de la utilización de los videojuegos por los niños y adolescentes/ Efectos benéficos de la de la utilización de los videojuegos por los niños y adolescentes/ Recomendaciones para favorecer el uso adecuado/ Sistema de clasificación de los videojuegos

Revisiting the U-238 thermal capture cross section and gamma-raymission probabilities from Np-239 decay

Energy Technology Data Exchange (ETDEWEB)

Trkov, A.; Molnar, G.L.; Revay, Zs.; Mughabghab, S.F.; Firestone,R.B.; Pronyaev, V.G.; Nichols, A.L.; Moxon, M.C.

2005-03-03

The precise value of the thermal capture cross section of238U is uncertain, and evaluated cross sections from various sourcesdiffer by more than their assigned uncertainties. A number of theoriginal publications have been reviewed to assess the discrepant data,corrections were made for more recent standard cross sections andotherconstants, and one new measurement was analyzed. Due to the strongcorrelations in activation measurements, the gamma-ray emissionprobabilities from the beta decay of 239Np were also analyzed. As aresult of the analysis, a value of 2.683 +- 0.012 barns was derived forthe thermal capture cross section of 238U. A new evaluation of thegamma-ray emission probabilities from 239Np decay was alsoundertaken.

Determination of 234U and 238U activity concentrations in groundwaters from three deep wells drilled in Itu Intrusive Suite (SP)

International Nuclear Information System (INIS)

Souza, Francisca de

2006-01-01

Activity concentrations of ( 234 U) and ( 238 U) were determined in groundwaters drawn from three deep wells drilled in rocks from Itu Intrusive Suite (SP), two located in Salto town (S and SY wells) and the other one in Itu (I well). Sampling was done from September, 2004 to December, 2005, and twelve samples of each well were collected monthly. For those determinations alpha spectrometry technique was used, providing high precision results, as shown by the very good agreement of the data obtained in the analyses of 23 duplicates. The waters from the three wells presented a considerable enrichment of 234 U in relation to 238 U, indicating an important radioactive disequilibrium of these isotopes. In well I, the activity concentrations of ( 238 U) varied from (1,06 +- 0,03) to (2,1+- 0,2) mBq/L and those of ( 234 U) spanned from (3,1 +- 0,2) to (6,0 +- 0,4) mBq/L, whereas ( 234 U/ 238 U) activity ratios did not present significant variation, during the sampling time interval, presenting an average of 2,8 +- 0,1. The S waters showed the lowest uranium concentrations and the largest diversity of ( 238 U) and ( 234 U) activity concentrations, which varied from (0,26 +- 0,02) to (1,07+- 0,08) mBq/L and from (1,8 +- 0,1) to (7,0 +- 0,5) mBq/L, respectively, and also presented variable ( 234 U/ 238 U) activity ratios, spanning from (2,79 +- 0,07) to (8,1+- 0,3). In SY well, ( 238 U) activities varied between (0,8 +- 0,1) and (4,2 +- 0,3) mBq/L and those ones of ( 234 U) from (14 +- 1) to (53 +- 4) mBq/L, whereas ( 234 U/ 238 U) ratios fell in the interval from 12,6 +- 0,3 to 18,3 +- 0,4, with the highest activities of both radioisotopes registered during the dry season and the lowest ones in the rainy time period. The ( 234 U/ 238 U) activity ratios, which were invariable during sampling period of well I, indicated the contribution of rainfall to recharge the aquifer. The observed correlation between those ratios and uranium concentrations, for S and SY wells, showed

NPM-ALK mediates phosphorylation of MSH2 at tyrosine 238, creating a functional deficiency in MSH2 and the loss of mismatch repair

International Nuclear Information System (INIS)

Bone, K M; Wang, P; Wu, F; Wu, C; Li, L; Bacani, J T; Andrew, S E; Lai, R

2015-01-01

The vast majority of anaplastic lymphoma kinase-positive anaplastic large cell lymphoma (ALK+ALCL) tumors express the characteristic oncogenic fusion protein NPM-ALK, which mediates tumorigenesis by exerting its constitutive tyrosine kinase activity on various substrates. We recently identified MSH2, a protein central to DNA mismatch repair (MMR), as a novel binding partner and phosphorylation substrate of NPM-ALK. Here, using liquid chromatography–mass spectrometry, we report for the first time that MSH2 is phosphorylated by NPM-ALK at a specific residue, tyrosine 238. Using GP293 cells transfected with NPM-ALK, we confirmed that the MSH2 Y238F mutant is not tyrosine phosphorylated. Furthermore, transfection of MSH2 Y238F into these cells substantially decreased the tyrosine phosphorylation of endogenous MSH2. Importantly, gene transfection of MSH2 Y238F abrogated the binding of NPM-ALK with endogenous MSH2, re-established the dimerization of MSH2:MSH6 and restored the sensitivity to DNA mismatch-inducing drugs, indicative of MMR return. Parallel findings were observed in two ALK+ALCL cell lines, Karpas 299 and SUP-M2. In addition, we found that enforced expression of MSH2 Y238F into ALK+ALCL cells alone was sufficient to induce spontaneous apoptosis. In conclusion, our findings have identified NPM-ALK-induced phosphorylation of MSH2 at Y238 as a crucial event in suppressing MMR. Our studies have provided novel insights into the mechanism by which oncogenic tyrosine kinases disrupt MMR

Toxicity of inhaled 238PuO2 in beagle dogs. A. Monodisperse 1.5 μm 238PuO2. B. Monodisperse 3.0 μm 238PuO2 particles. III

International Nuclear Information System (INIS)

Lustgarten, C.S.; Mewhinney, J.A.; Hobbs, C.H.; Halliwell, W.H.; Jones, R.K.; Mauderly, J.L.; McClellan, R.O.; Mo, T.; Pickrell, J.A.

1976-01-01

To obtain essential information on the importance of the homogeneity or non-homogeneity of the radiation dose to lung (the hot particle question), Beagle dogs have been exposed to monodisperse aerosols (sigma/sub g/ 238 PuO 2 of either 1.5 μm or 3.0 μm aerodynamic diameter (AD). By using monodisperse particles of these two sizes, the average dose to lung is held constant for a given initial lung burden, but the local alpha dose around the two sizes of particles varies by a factor of about ten. All exposures have been completed with 72 days exposed to each of the two particle sizes of 238 PuO 2 (total of 144 dogs) resulting in graded initial lung burdens which range from .005 to 2.2 μCi/kg of body weight. Twenty-four dogs exposed to the diluent aerosol are serving as controls. The animals will be studied over their total life span. Two exposed dogs have died from pulmonary injury: Dog 710C (with an initial lung burden of 2.0 μCi/kg) died at 631 days after inhalation of 3.0 μm AD aerosol. The cause of death was radiation pneumonitis and pulmonary fibrosis, Dog 746B (with an initial lung burden of 1.3 μCi/kg) died at 791 days after inhalation of 1.5 μm AD aerosol. Death was attributed to intrapulmonic hemorrhage resulting from a degenerative vasculitis. One control dog (721A) was euthanized at 820 days after exposure due to a meningitis and encephalomalacia that caused a severe central nervous system disorder that made the dog difficult to handle.A leukopenia in exposed dogs to date has occurred earlier and to a greater degree in dogs exposed to 3.0 μm AD particles than in dogs that recevied 1.5 μm AD particles. One hundred forty-two exposed and 23 control dogs are surviving at 175 to 1024 days after exposure

Associação de níveis plasmáticos de PAI-1 e polimorfismo 4G/5G em pacientes com doença arterial coronariana PAI-1 4G/5G polymorphism and plasma levels association in patients with coronary artery disease

Directory of Open Access Journals (Sweden)

Luciana Moreira Lima

2011-12-01

Full Text Available FUNDAMENTO: O polimorfismo 4G/5G do inibidor ativador do plasminogênio tipo 1 (PAI-1 pode influenciar a expressão do PAI-1. Níveis plasmáticos elevados de PAI-1 estão associados com Doença Arterial Coronariana (DAC. OBJETIVO: O presente estudo investigou a influência do polimorfismo 4G/5G do PAI-1 nos níveis plasmáticos de PAI-1 e sua associação com DAC avaliada por angiografia coronária. MÉTODOS: Foi avaliada amostra de sangue de 35 indivíduos com artérias coronárias angiograficamente normais, 31 indivíduos apresentando ateromatose leve/moderada, 57 indivíduos apresentando ateromatose grave e 38 indivíduos saudáveis (controles. Em pacientes e controles, o polimorfismo 4G/5G do PAI-1 foi determinado por amplificação da proteína-C reativa utilizando primers específicos de alelo. Os níveis plasmáticos de PAI-1 foram quantificados pelo ensaio ELISA (American Diagnostica. RESULTADOS: Não houve diferença entre os grupos quanto a sexo, idade e índice de massa corporal. Níveis plasmáticos de PAI-1 e frequência do genótipo 4G/4G mostravam-se significativamente maiores no grupo com ateromatose grave em comparação com os outros grupos (p 70% (p BACKGROUND: Type-1 plasminogen activator inhibitor (PAI-1 4G/5G polymorphism may influence the PAI-1 expression. High plasma levels of PAI-1 are associated with coronary artery disease (CAD. OBJECTIVE: This study investigated the influence of PAI-1 4G/5G polymorphism on plasma PAI-1 levels and its association with CAD assessed by coronary angiography. METHODS: Blood sample of 35 individuals with angiographycally normal coronary arteries, 31 individuals presenting mild/moderate atheromatosis, 57 individuals presenting severe atheromatosis and 38 healthy individuals (controls were evaluated. In patients and controls, the PAI-1 4G/5G polymorphism was determined by PCR amplification using allele-specific primers. Plasma PAI-1 levels were quantified by ELISA assay (American Diagnostica

Conceptual designs for a long term 238PuO2 storage vessel

International Nuclear Information System (INIS)

Kwon, D.M.; Replogle, W.C.

1996-08-01

This is a report on conceptual designs for a long term, 250 years, storage container for plutonium oxide ([sup 238]PuO[sub 2]). These conceptual designs are based on the use of a quartz filter to release the helium generated during the plutonium decay. In this report a review of filter material selection, design concepts, thermal modeling, and filter performance are discussed

Association between TNF-α-238G/A gene polymorphism and OCD susceptibility: A meta-analysis.

Science.gov (United States)

Jiang, Caixiao; Ma, Xinyan; Qi, Shunxiang; Han, Guangyue; Li, Yan; Liu, Yanfang; Liu, Lanfen

2018-02-01

Tumor necrosis factor-alpha (TNF-α) is an important cytokine and has been reported to be associated with the pathogenesis of many autoimmune and inflammatory diseases. TNF-α gene is located on a region that has been found to be associated with obsessive-compulsive disorder (OCD). We performed this meta-analysis to assess the relationship between susceptibility to OCD and the TNF-α-238G/A gene polymorphism. An extensive search of the available literature on the association between the susceptibility to OCD and the TNF gene polymorphism was conducted by searching PubMed, Web of Knowledge, Embase, Chinese Web of Knowledge, Wanfang, and Chongqing VIP database. The database was searched up to December 2016 and includes language of English and/or Chinese with the keywords of "obsessive-compulsive disorder" or "OCD," polymorphism or variant or mutation, "tumor necrosis factor" or "TNF" or "cytokine." The association between TNF-α-238G/A gene polymorphism and the susceptibility of OCD was anticipated by odds ratio (OR) with the corresponding 95% confidence interval (95% CI). Four studies including 435 cases and 1073 controls were incorporated in our meta-analysis. In general, TNF-α-238G/A gene polymorphism might lead to a decreased risk of OCD susceptibility (G vs A genotype model: OR = 1.01, 95% CI = 0.37-2.77, P = .981; GG vs AA+AG model: OR = 0.93, 95% CI = 0.37-2.36, P = .879; GG+AG vs AA model: OR = 0.22, 95% CI = 0.06-0.73, P = .014; GG vs AA model: OR = 0.21, 95% CI = 0.06-0.71, P = .012; AG vs AA model: OR = 0.29, 95% CI = 0.07-1.16, P = .081; GG+AA vs AG model: OR = 1.17, 95% CI = 0.55-2.51, P = .683). TNF-α-238G/A gene polymorphism might lead to a decreased risk of OCD susceptibility.

Análise de polimorfismos do gene da kapa-caseína em fêmeas da raça Nelore e efeito sobre o peso à desmama de suas progênies Polimorphism analysis of kappa -casein gene on Nelore females and effect on weaning weight of the calves

Directory of Open Access Journals (Sweden)

F.J.C. Faria

1999-08-01

Full Text Available Informações sobre peso à desmama de um rebanho Nelore, após ajuste para idade padrão de 205 dias, sexo da cria, idade da mãe, touro e mês de desmama, foram utilizadas para separar as reprodutrizes em dois grupos, cujos produtos diferiam em peso. As médias ajustadas pelo método dos quadrados mínimos e erros-padrão para os grupos pesado (P e leve (L foram 163,21±2,18kg e 134,44±2,18kg, respectivamente, com 41 animais em cada grupo. Colheram-se amostras de sangue das reprodutrizes para o estudo de polimorfismos do gene da kapa-caseína, pela técnica de polymerase chain reaction-restriction fragment length polymorphism. A análise de um segmento do éxon IV do gene da kapa-caseína identificou os genótipos 71AA, 10AB e 1BB, com as freqüências de 0,92 e 0,08 para os alelos A e B, respectivamente. Os pesos à desmama dos produtos dos genótipos AA e AB foram, respectivamente, 147,73±2,38kg e 156,76±6,35kg. Os grupos P e L não diferiram entre si quanto às freqüências alélicas apresentadas para esse gene. O genótipo das reprodutrizes não afetou o peso à desmama de suas crias, existindo, portanto, outros efeitos genéticos e não genéticos de maior magnitude.Data from a Nelore herd were used after adjustment of the weaning weight for 205 days of age, sex, age of dam, sire and month of weaning resulting two groups of cows that differed in weaning weight of their calves. The least square means (LSM and standard error (SE were 163.21±2.18kg and 134.44±2.18kg, for heavy (H and light (L groups, with 41 animals each one. These animals were genotyped for DNA polymorphisms of kappa-casein gene, using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism. The segment analysis of kappa-casein IV exon identified the genotypes 71AA, 10AB and 1BB, with frequencies of 0.92 and 0.08 for A and B alleles, respectively. The LSM±SE for weaning weight were 147.73±2.38kg and 156.76± 6.35kg for calves of AA and AB

Measurement of neutron inelastic scattering cross section of {sup 238}U

Energy Technology Data Exchange (ETDEWEB)

Miura, Takako; Baba, Mamoru; Ibaraki, Masanobu; Sanami, Toshiya; Win, Than; Hirasawa, Yoshitaka; Matsuyama, Shigeo; Hirakawa, Naohiro [Tohoku Univ., Sendai (Japan)

1998-03-01

Neutron scattering from the 0{sup +}, 2{sup +} (1-st) and 4{sup +} (2nd) levels of {sup 238}U was measured for incident energies between 0.4 and 0.85 MeV at the Tohoku University 4.5 MV Dynamitron facility, using the time-of-flight (TOF) method with monoenergetic pulsed neutrons by the {sup 7}Li(p,n) reaction. The results are presented in comparison with other experimental data and evaluated data. (author)

The metrological activity determination of 238 U and 230 Th by gamma spectrometry to industrial fuel-cycle application

International Nuclear Information System (INIS)

Almeida M, M.C. de; Delgado, J.U.; Poledna, R.

2006-01-01

This work describes the difficulty for determining the activity of 238 U and 230 Th using gamma spectrometry due to the low gamma-ray emission probabilities of 92 and 67 keV, and, mainly, the associated high uncertainties about 13 and 11%, respectively. 230 Th is a 238 U daughter and it is product from uranium mills and refineries. 230 Th decays to 226 Ra and this decay has to be measured because these radionuclides are not in secular equilibrium with their daughter products, besides the gamma-energies have high uncertainties in the emission probabilities. These radionuclides, mostly 238 U, are important in the nuclear fuel-cycle, since the mining of uranium ore, where the nominal isotopic content of natural uranium is 99.27% of 238 U, until the irradiated fuel reprocessing, where this isotope, a fertile material, is recovered to be used again. The uranium and thorium are considered safeguarded nuclear materials and the metrology tries to calibrate and standardize these materials to improve the activity determination techniques applied in different fuel-cycle scopes. The essential characteristics of the safeguarded materials are low gamma energies (less than 100 keV) and emission probabilities but with high uncertainties. In this way, the metrology can contribute to homeland security defense against illicit nuclear trafficking with the identification and quantification of the safeguarded radionuclides such as uranium and thorium, using specific gamma window energy and high resolution planar or coaxial germanium detector. The efficiency curve is obtained from the reference source spectrum considering the photopeak areas corresponding the standard activities. This curve depends on radiation energy, sample geometry, photon attenuation (sample absorption and material absorption between sample-detector), dead time and sample-detector position. The metrological activity determinations of 238 U solid sources, and of 230 Th, in solution (5 ml flask), were performed using

A review of the behaviour of U-238 series radionuclides in soils and plants

International Nuclear Information System (INIS)

Mitchell, N; Pérez-Sánchez, D; Thorne, M C

2013-01-01

The U-238 series of radionuclides is of relevance in a variety of environmental contexts ranging from the remediation of former uranium mining and milling facilities to the deep geological disposal of solid radioactive wastes. Herein, we review what is known concerning the behaviour of radionuclides from the U-238 decay chain in soils and plants. This review is intended to provide a single comprehensive source of information to anyone involved in undertaking environmental impact assessment studies relating to this decay chain. Conclusions are drawn relating to values and ranges of distribution coefficients appropriate to uranium, thorium, radium, lead and polonium in different soil types and under various environmental conditions. Similarly, conclusions are drawn relating to plant:soil concentration ratios for these elements for different plant and soil types, and consideration is given to the distribution of these elements within plants following both root uptake and foliar application. (review)

Electric quadrupole giant resonance in the photofission of sup(238)U IFUSP-P--140

International Nuclear Information System (INIS)

Bhandari, B.S.; Arruda Neto, J.D.T.; Herdade, S.B.; Nascimento, I.C.

1978-02-01

The 238 U nucleus was studied measuring the electrofission yield and angular distributions of fission fragments, in the energy range of 5.5 to 28.3 MeV, using a new method of analysis. An E2 isoscalar giant resonance was found in the photofission cross section of 238 U. This resonance exhausts (71 + -7)% of the EWSR and is located at 9.9 + -0.2 MeV with a width of 6.8 + -0.4 MeV. The position of this resonance is in reasonable agreement with the Bohr and Mottelson prediction (58.Asup( - 1/3MeV). The width of 6.8 + -0.4 MeV is compatible with a possible triple splitting of the resonance. From the angular distributions of photofission fragments and yield measurements of multipoles other than E1, evidence of an M1 mixture in the energy region 6-7 MeV was found

(238)U and total radioactivity in drinking waters in Van province, Turkey.

Science.gov (United States)

Selçuk Zorer, Özlem; Dağ, Beşir

2014-06-01

As part of the national survey to evaluate natural radioactivity in the environment, concentration levels of total radioactivity and natural uranium have been analysed in drinking water samples. A survey to study natural radioactivity in drinking waters was carried out in the Van province, East Turkey. Twenty-three samples of drinking water were collected in the Van province and analysed for total α, total β and (238)U activity. The total α and total β activities were counted by using the α/β counter of the multi-detector low background system (PIC MPC-9604), and the (238)U concentrations were determined by inductively coupled plasma-mass spectrometry (Thermo Scientific Element 2). The samples were categorised according to origin: tap, spring or mineral supply. The activity concentrations for total α were found to range from 0.002 to 0.030 Bq L(-1) and for total β from 0.023 to 1.351 Bq L(-1). Uranium concentrations ranging from 0.562 to 14.710 μg L(-1) were observed in drinking waters. Following the World Health Organisation rules, all investigated waters can be used as drinking water.

Comparison of the simulated diffusion of 238U and 234U isotopes with profile data from granite fractures

International Nuclear Information System (INIS)

Latham, A.G.

1991-01-01

The observed profiles of uranium content and 234 U/ 238 U activity ratios as they vary with distance into the rock at a granite fracture wall have been interpreted using a simple diffusion-sorption model. For simplicity, the model assumes a linear reversible isotherm. Using simple constraints, it has been possible to estimate long-term values appropriate for the distribution coefficient, K d for uranium in granite. A potential constraint on the uranium K d value is provided by the 234 U/ 238 U activity ratio variations. However, natural 234 U/ 238 U activity ratios seldom change monotonically with distance and it is suspected that they are the result, to some extent, of later uranium removal. To take this approach further, corresponding physical rock property data and closer sampling in the fracture profiles would be required. Estimates of K d are in the range 0.1 to 10 m 3 kg -1 , and are in agreement with the upper part of the range obtained from laboratory experiments. (author)

BetaScint{trademark} fiber-optic sensor for detecting strontium-90 and uranium-238 in soil. Innovative technology summary report

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-12-01

Accurate measurements of radioactivity in soils contaminated with Strontium-90 (Sr-90) or Uranium-238 (U-238) are essential for many DOE site remediation programs. These crucial measurements determine if excavation and soil removal is necessary, where remediation efforts should be focused, and/or if a site has reached closure. Measuring soil contamination by standard EPA laboratory methods typically takes a week (accelerated analytical test turnaround) or a month (standard analytical test turnaround). The time delay extends to operations involving heavy excavation equipment and associated personnel which are the main costs of remediation. This report describes an application of the BetaScint{trademark} fiber-optic sensor that measures Sr-90 or U-238 contamination in soil samples on site in about 20 minutes, at a much lower cost than time-consuming laboratory methods, to greatly facilitate remediation. This report describes the technology, its performance, its uses, cost, regulatory and policy issues, and lessons learned.

BetaScintTM fiber-optic sensor for detecting strontium-90 and uranium-238 in soil. Innovative technology summary report

International Nuclear Information System (INIS)

1998-12-01

Accurate measurements of radioactivity in soils contaminated with Strontium-90 (Sr-90) or Uranium-238 (U-238) are essential for many DOE site remediation programs. These crucial measurements determine if excavation and soil removal is necessary, where remediation efforts should be focused, and/or if a site has reached closure. Measuring soil contamination by standard EPA laboratory methods typically takes a week (accelerated analytical test turnaround) or a month (standard analytical test turnaround). The time delay extends to operations involving heavy excavation equipment and associated personnel which are the main costs of remediation. This report describes an application of the BetaScint trademark fiber-optic sensor that measures Sr-90 or U-238 contamination in soil samples on site in about 20 minutes, at a much lower cost than time-consuming laboratory methods, to greatly facilitate remediation. This report describes the technology, its performance, its uses, cost, regulatory and policy issues, and lessons learned

Angular distribution of fragments from neutron-induced fission of {sup 238}U in the intermediate energy region

Energy Technology Data Exchange (ETDEWEB)

Carlsson, Magnus

2004-06-01

Areas ranging from nuclear structure models to accelerator-driven systems benefit from improved neutron-induced fission data in the intermediate energy region. In this Master's degree thesis, the fragment angular distribution from fission of {sup 238}U, induced by 21-MeV neutrons, has been analysed from an experiment performed with the Medley/DIFFICILE setup at the The Svedberg Laboratory in Uppsala. The data have been corrected for low energy neutrons in the beam. The results agree with other experiments, as well as with model calculations. The data should be a starting point for further analysis with a goal to deduce the fission cross-section of {sup 238}U.

Comparison of measured and calculated 238U capture self-indication ratios from 4 to 10 keV

International Nuclear Information System (INIS)

Perez, R.B.; de Saussure, G.; Yang, J.T.; Munoz-Cobos, J.L.; Todd, J.H.

1983-01-01

From 4 keV to 149 keV the 238 U cross sections are represented in ENDF/B-V by unresolved-resonance parameters (URP). The purpose of this representation is to enable the calculation of resonance self-protection as a function of temperature and dilution. Since the URPs are not defined unambiguously by the cross-section data, it is important that the unresolved representation be tested with appropriate experiments, such as capture self-indication ratio (SIR) measurements. In this paper we compare 238 U capture SIR measurements in the 4- to 10-keV energy range with calculations done with ENDF/B-V and with recently published resolved resonance parameters

Study of an automatic dosing of neptunium in the industrial process of separation neptunium 237-plutonium 238

International Nuclear Information System (INIS)

Ros, Pierre

1973-01-01

The objective is to study and to adapt a method of automatic dosing of neptunium to the industrial process of separation and purification of plutonium 238, while taking the information quality and economic aspects into account. After a recall of some generalities on the production of plutonium 238, and the process of separation plutonium-neptunium, the author addresses the dosing of neptunium. The adopted measurement technique is spectrophotometry (of neptunium, of neptunium peroxide) which is the most flexible and economic to adapt to automatic control. The author proposes a project of chemical automatic machine, and discusses the complex (stoichiometry, form) and some aspects of neptunium dosing (redox reactions, process control) [fr

Neutron data evaluation of {sup 238}U

Energy Technology Data Exchange (ETDEWEB)

Maslov, V.M.; Porodzinskij, Y.V.; Hasegawa, Akira; Shibata, Keiichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-08-01

Cross sections for neutron-induced reactions on {sup 238}U are calculated by using the Hauser-Feshbach-Moldauer theory, the coupled channel model and the double-humped fission barrier model. The direct excitation of ground state band levels is calculated with a rigid-rotator model. The direct excitation of vibrational octupole and K = 2{sup +} quadrupole bands is included using a soft (deformable) rotator model. The competition of inelastic scattering to fission reaction is shown to be sensitive to the target nucleus level density at excitations above the pairing gap. As for fission, (n,2n), (n,3n), and (n,4n) reactions, secondary neutron spectra data are consistently reproduced. Pre-equilibrium emission of first neutron is included. Shell effects in the level densities are shown to be important for estimation of energy dependence of non-emissive fission cross section. (author). 105 refs.

Análisis de los polimorfismos de longitud de los fragmentos de restricción (RFLP del gen ribosómico 18S RNA de nutria gigante de río Pteronura brasiliensis

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J. Hernández

2001-07-01

Full Text Available La nutria gigante de río Pteronura brasiliensises un mamífero carnívoro de la familia Mustelidae, ala cual pertenecen también las tairas, las martas y los hurones. La nutria es considerada por elCITES como una especie vulnerable y por la IUCN como especie en peligro de extinción. Por estarazón, el Centro de Biología Molecular del Gimnasio Campestre inicio un proyecto de genética conservacionista que pretende proveer información utilizable para el análisis, tanto de la especieP. brasiliensiscomo de sus familiares mas cercanos, y de esta forma, proponer planes de manejo dela especie y su hábitat previniendo su extinción.

Poliformismo e expressão gênica da leptina em bovinos superprecoces

OpenAIRE

Salman, Ana Karina Dias [UNESP

2003-01-01

Este estudo foi conduzido com novilhos pertencentes a diferentes grupos genéticos, Angus x Nelore (n=31), Simental x Nelore (n=30) e Canchim (n=30), objetivando identificar SSCPs (Polimorfismos de Conformação de Cadeia Simples) e RFLP (Polimorfismo no Comprimento do Fragmento de Restrição) no gene da obesidade e relacionar esses polimorfismos com a área-de-olho-de-lombo (AOL) e a espessura de gordura subcutânea (EGS) na carcaça. Cinco pares de oligonucleotídeos iniciadores foram desenhados co...

Light nuclides produced in the proton-induced spallation of {sup 238}U at 1 GeV

Energy Technology Data Exchange (ETDEWEB)

Ricciardi, M.V.; Armbruster, P. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Benlliure, J. [Universidad de Santiago de Compostela (ES)] [and others

2005-09-01

The production of light and intermediate-mass nuclides formed in the reaction {sup 1}H+{sup 238}U at 1 GeV was measured at the fragment separator (FRS) at GSI, Darmstadt. The experiment was performed in inverse kinematics, shooting a 1 A GeV {sup 238}U beam on a thin liquid-hydrogen target. 254 isotopes of all elements in the range 7{<=}Z{<=}37 were unambiguously identified, and the velocity distributions of the produced nuclides were determined with high precision. The results show that the nuclides are produced in a very asymmetric binary decay of heavy nuclei originating from the spallation of uranium. All the features of the produced nuclides merge with the characteristics of the fission products as their mass increases. (orig.)

Certification of a uranium-238 dioxide reference material for neutron dosimetry (EC nuclear reference material 501)

International Nuclear Information System (INIS)

Pauwels, J.; Lievens, F.; Ingelbrecht, C.

1989-01-01

Uranium-238 oxide of 99.999% isotopic and 99.98% chemical purity was transformed into dioxide spheres of nominal 0.5 and 1.0 mm diameter by gel precipitation and subsequent calcination under carbon dioxide and under argon containing 5% hydrogen at 1 125 K. The spheres were analysed by thermal ionization mass spectrometry, including isotope dilution, by gravimetry and by potentiometric titration. On the basis of these analyses, the uranium mass fraction was certified at 879.4 ± 2.8 g.kg -1 , and the 235 U/U - and 238 U/U abundances at 10.4 ± 0.5 mg.kg -1 and 999.9896 ± 0.0005 g.kg -1 , respectively. The material is intended to be used as a reference material in neutron metrology

Measurement of the 234U/238U activity ratios in the organs and internal tissues of a domestic goat kid (Capra aegagrus hircus)

International Nuclear Information System (INIS)

Francesco De Santis; Massimo Esposito

2015-01-01

In this paper, we compare the 234 U/ 238 U activity ratios (ARs) in various internal tissues and organs of a goat kid with the ingested 234 U/ 238 U AR to assess isotopic fractionation. The results obtained from soft tissues (i.e., the kidneys, liver, lung, and bladder) that undergo indirect assimilation of uranium from the feed through the bloodstream suggest an increase in the 234 U/ 238 U AR. In contrast, the intestine, bones and feces had the same AR values as the feed. Finally, we broadly assess uranium transfer from the feed to the animal based on the concentration ratio and the feed transfer coefficient. (author)

Toxicity Reduction of Reactive Red Dye-238 Using Advanced Oxidation Process by Solar Energy

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Riyad Al-Anbari

2017-09-01

Full Text Available Decolorization of red azo dye (Cibacron Red FN-R from synthetic wastewater has been investigated as a function of solar advanced oxidation process. The photocatalytic activity using ZnO as a photocatalysis has been estimated. Different parameters affected the removal efficiency, including pH of the solution, initial dye concentration and H2O2 concentration were evaluated to find out the optimum value of these parameters. The results proved that the optimal pH value was 8 and the most efficient H2O2 concentration was 100mg/L. Toxicity reduction percent for effluent solution was also monitored to assess the degradation process. This treatment method was able to strongly reduce the color and toxicity of reactive red dye-238 to about (99 and 80 % respectively. It can be concluded, from these experiments, that the using of ZnO as a photocatalysis was exhibited as economical and efficient treatment method to remove reactive red dye-238 from aqueous solution.

Air monitoring data reveal previously unknown contamination at radioactive waste disposal area, Los Alamos National Laboratory

International Nuclear Information System (INIS)

Kraig, D.H.; Conrad, R.C.

2000-01-01

Air monitoring at Area G, the low-level radioactive waste disposal area at Los Alamos National Laboratory, revealed increased air concentrations of 239 Pu and 241 Am at one location along the north boundary. This air monitoring location is a couple of meters north of a dirt road used to access the easternmost part of Area G. Air concentrations of 238 Pu were essentially unaffected which was puzzling because both 238 Pu and 239 Pu are present in the local, slightly contaminated soils. Air concentrations of these radionuclides increased about a factor of ten in early 1995 and remained at those levels until the first quarter of 1996. During the spring of 1996 air concentrations again increased by a factor of about ten. No other radionuclides were elevated, and no other Area G stations showed elevations of these radionuclides. After several formal meetings did not provide an adequate explanation for the elevations, a gamma-survey was performed and showed a small area of significant contamination just south of the monitor location. We found that in February 1995, a trench for a water line had been dug within a meter or so of the air stations. Then, during early 1996, the dirt road was rerouted such that its new path was directly over the unknown contamination. It appears that the trenching brought contaminated material to the surface and caused the firs rise in air concentrations and then the rerouting of the road over the contamination caused the second rise, during 1996. We also found that during 1976 and 1977 contaminated soils from the clean-up of an old processing facility had been spread over the filled pits in the vicinity of the air monitors. These soils, which were probably the source of the air contamination, were very low in 238 Pu which explains why we saw very little 238 Pu in the increased air concentrations. A layer of gravel and sand was spread over the contaminated area. Although air concentrations of 239 Pu and 241 Am dropped considerably, they have

Background radioactivity in sediments near Los Alamos, New Mexico

International Nuclear Information System (INIS)

McLin, Stephen G.

2004-01-01

River and reservoir sediments have been collected annually by Los Alamos National Laboratory since 1974 and 1979, respectively. These background samples are collected from five river stations and four reservoirs located throughout northern New Mexico and southern Colorado. Analyses include 3 H, 90 Sr, 137 Cs, total U, 238 Pu, 239,240 Pu, 241 Am, gross alpha, gross beta, and gross gamma radioactivity. Surprisingly, there are no federal or state regulatory standards in the USA that specify how to compute background radioactivity values on sediments. Hence, the sample median (or 0.50 quantile) is proposed for this background because it reflects central data tendency and is distribution-free. Estimates for the upper limit of background radioactivity on river and reservoir sediments are made for sampled analytes using the 0.95 quantile (two-tail). These analyses also show that seven of ten analytes from reservoir sediments are normally distributed, or are normally distributed after a logarithmic or square root transformation. However, only three of ten analytes from river sediments are similarly distributed. In addition, isotope ratios for 137 Cs/ 238 Pu, 137 Cs/ 239,240 Pu, and 239,240 Pu/ 238 Pu from reservoir sediments are independent of clay content, total organic carbon/specific surface area (TOC/SSA) and cation exchange capacity/specific surface area (CEC/SSA) ratios. These TOC/SSA and CEC/SSA ratios reflect sediment organic carbon and surface charge densities that are associated with radionuclide absorption, adsorption, and ion exchange reactions on clay mineral structures. These latter ratio values greatly exceed the availability of background radionuclides in the environment, and insure that measured background levels are a maximum. Since finer-grained reservoir sediments contain larger clay-sized fractions compared to coarser river sediments, they show higher background levels for most analytes. Furthermore, radioactivity values on reservoir sediments have

The AS-76 interlaboratory experiment on the alpha spectrometric determinaion of Pu-238. Part 3: Preparation and characterization of samples

International Nuclear Information System (INIS)

Bortels, G.; Broothaerts, J.; Bievre, P. de

1980-01-01

Four plutonium samples containing 0.2, 0.8, 1.6 and 0.9 atom % of 238 Pu have been prepared for the Interlaboratory Experiment AS-76. Of these three were input solutions from a reprocessing plant. The fourth sample was from a plutonium product solution. These samples have been characterized by two alpha spectrometry laboratories and two mass spectrometry laboratories to certify the ratio of alpha activities 238 Pu/( 239 Pu + 240 Pu) and the isotopic composition, respectively

Transmutation of 129I, 237Np, 238Pu, 239Pu, and 241Am using ...

Indian Academy of Sciences (India)

Results of transmutation studies of 129I, 237Np, 238Pu, 239Pu and 241Am are presented. Keywords. ... J Adam et al. Table 1. Samples properties for 0.7 and 1 GeV experiments. ..... If we suppose that this conclusion is true also for ratios in ...

LA PERCEPCIÓN DEL SOBREPESO Y LA OBESIDAD INFANTIL POR PARTE DE LOS PROGENITORES

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Amelia Rodríguez Martín

2012-01-01

Full Text Available Fundamento: Con frecuencia los padres no perciben la sobrecarga ponderal de sus hijos. El objetivo de este trabajo es estudiar con que frecuencia se produce este hecho y si esta percepción se asocia a diferencias en hábitos alimentarios, actividad física y sedentarismo de sus hijos. Métodos: Estudio transversal de 1.620 niños de 3 a 16 años seleccionados en un muestreo por conglomerados (2008-2010. 454 presentaron sobrecarga ponderal. Se estudiaron sus características antropométricas, hábitos alimentarios, actividad física (adaptación cuestionarios Cindi/Maraton y sedentarismo. Analizamos las diferencias con niños con normopeso, sobrecarga ponderal percibida y no percibida (chi2 y Anova. Resultados: Los padres percibieron el 34,7% del sobrepeso y un 72,3% de obesidad en sus hijos varones, y un 10,8% y 53,8% respectivamente en las hijas. Los padres y madres obesos identifican un 54,5% y el 57,7% de los casos de sobrecarga ponderal de varones, frente al 23,8% y 27,8% en niñas. La percepción del exceso de peso se asocio a la cualificación profesional del padre (47% y a la de ser ama de casa en las mujeers (40%. La percepción coincidió con mayor cumplimiento de recomendaciones de actividad física en los hijos (67,5 vs. 77,3% e hijas (47,5% vs 55,6% más jóvenes, menor sedentarismo en éstas (42,6% vs. 38,9%, y discretas diferencias por sexo y edad en los hábitos alimentarios. Conclusiones: Un porcentaje significativo de casos con sobrecarga ponderal infantil no es percibida por sus padres debiéndose estudiar sus causas y por qué esta percepción parental no determina diferencias en alimentación, actividad física y sedentarismo de sus hijos.

Bioaccumulation, distribution, and dose of 241Am, 244Cm, and 238Pu in developing fish embryos

International Nuclear Information System (INIS)

Till, J.E.; Frank, M.L.

1977-01-01

The dose from several actinide elements to a sensitive stage in the development of one type of aquatic biota, the fish egg, was assessed. An investigation was made of the uptake and distribution of 241 Am, 244 Cm and 238 Pu by developing embryos of fish. Eggs from ripe carp, Cyprinos carpio, that had been spawned in the laboratory were placed in dishes containing 241 Am(III)- 244 Cm(III)-, or 238 Pu(IV)-citrate in solution at an activity concentration of approximately 10 -3 μCi/ml. Samples of eggs were taken at seven intervals during the 72-hour period of embryogenesis. Egg contents were separated from the membrane prior to analysis to quantify the activity that penetrated the chorion. Autoradiographs of 16-μm thick egg sections confirmed that alpha radioactivity was present in the egg contents and permitted the distribution of activity to be determined. Concentration factors were calculated based on activity ratios for the egg contents (excluding the chorion) over the development period. Maximum concentration factors occurred at hatching and were found to be 25, 40 and 3 for 241 Am, 244 Cm and 238 Pu, respectively. Collectively, these data were used to estimate the dose from americium, curium and plutonium in natural ecosystems to developing fish eggs which have similar embryological characteristics as carp

Evaluation of Aqueous and Powder Processing Techniques for Production of Pu-238-Fueled General Purpose Heat Sources

Energy Technology Data Exchange (ETDEWEB)

2008-06-01

This report evaluates alternative processes that could be used to produce Pu-238 fueled General Purpose Heat Sources (GPHS) for radioisotope thermoelectric generators (RTG). Fabricating GPHSs with the current process has remained essentially unchanged since its development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the fields of chemistry, manufacturing, ceramics, and control systems. At the Department of Energy’s request, alternate manufacturing methods were compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product. An expert committee performed the evaluation with input from four national laboratories experienced in Pu-238 handling.

Variantes del Papilomavirus Humano 16 y su asociación con el HLA en cáncer cervical Variants of Human Papillomavirus 16 and its association with HLA in cervical cancer

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Jehidys Montiel Ramos

2010-12-01

Full Text Available El cáncer cervical es el segundo cáncer más común en mujeres en el mundo y es el principal cáncer en mujeres en países en desarrollo. La infección persistente por los genotipos oncogénicos del Virus del Papiloma Humano (VPH es la causa necesaria para el desarrollo del cáncer cervical, siendo el VPH-16 el genotipo responsable del 50-60% de los casos. Las variantes No Europeas del VPH-16 han sido asociadas con infección persistente, lesiones de alto grado y cáncer. Los polimorfismos del Antígeno Leucocitario Humano (HLA están también asociados con la susceptibilidad al cáncer cervical y se ha postulado una relación entre variantes del VPH y ciertos alelos del HLA. La presente revisión hace referencia a la relación entre los polimorfismos de HLA y el desarrollo de cáncer cervical y la evidencia que documenta la interrelación de este factor con la variabilidad del VPH-16. Salud UIS 2010; 42: 272-280Cervical cancer is the second most common cancer in women worldwide and the most frequent cancer in women of the majority of developing countries. Persistent infection with Human Papillomavirus (HPV oncogenic types of HPV is necessary to develop cervical, cancer, with HPV-16 responsible for 50-60% of cases. Non-European variants of HPV-16 have been associated with persistant infection and high degree cervical cancer. Human Leucocyte Antigen (HLA polymorphisms are also associated with susceptibility to cervical cancer. It has been suggested relationship between HPV-16 variability and some HLA Alleles., This revision refers to the relation between HLA polymorphisms and cervical cancer development, and present evidence that may explain its relation with HPV-16 variability. Salud UIS 2010; 42: 272-280

{sup 238}U and {sup 232}Th concentrations in various foodstuffs in Morocco and resulting radiation doses to the members of the public; Concentrations en {sup 238}U et {sup 232}Th dans differents aliments au Maroc et doses de radiations en resultant pour les membres du public

Energy Technology Data Exchange (ETDEWEB)

Misdaq, M.A.; Elamyn, H.; Erramli, H. [Cadi Ayyad Univ., Nuclear Physics and Techniques Lab., Faculty of Sciences Semlalia, Marrakech (Morocco)

2008-04-15

Uranium ({sup 238}U) and thorium ({sup 232}Th) concentrations were measured in different foods widely consumed in Morocco by using C.R.-39 and L.R.-115 type II solid state nuclear track detectors (S.S.N.T.D.). Data obtained were compared to those obtained by using isotope dilution mass spectrometry (I.D.M.S.). Total daily intakes of {sup 238}U and {sup 232}Th for a typical food basket were estimated to be 1.3 {+-} 0.1 mBq d{sup -1} and 0.98 {+-} 0.08 mBq d{sup -1}, 1.4 {+-} 0.1 mBq d{sup -1} and 1.06 {+-} 0.08 mBq d{sup -1}, 1.7 {+-} 0.1 mBq d{sup -1} and 1.26 {+-} 0.08 mBq d{sup -1} and 2.0 {+-} 0.1 mBq d{sup -1} and 1.5 {+-} 0.1 Bq d{sup -1} for the 2-7 years, 7-12 years, 12-17 years and adult's age groups, respectively. Alpha-activities due to annual {sup 238}U and {sup 232}Th intakes from the ingestion of the studied foodstuffs were determined in different organs and tissues of the human body of members of the public by using the ICRP gastrointestinal tract and systemic part models for these radionuclides. Committed equivalent doses due to annual intakes of {sup 238}U and {sup 232}Th were evaluated in the human body organs and tissues for different age groups of the Moroccan population by exploiting data obtained for alpha-doses deposited by 1 Bq of {sup 238}U and 1 Bq of {sup 232}Th in the considered human organs and tissues. The influence of the mass of the target tissue and activities due to {sup 238}U and {sup 232}Th on the committed equivalent doses due to annual intakes of these radionuclides in the organs and tissues of the human body was studied. (authors)

238U-234U-230Th chronometry of Fe-Mn crusts: Growth processes and recovery of thorium isotopic ratios of seawater

International Nuclear Information System (INIS)

Chabaux, F.; Cohen, A.S.; O'Nions, R.K.; Hein, J.R.

1995-01-01

Comparison of ( 234 U) excess /( 238 U) and ( 230 Th)/( 232 Th) activity ratios in oceanic Fe-Mn deposits provides a method for assessing the closed-system behaviour of 238 U- 234 U- 230 Th, as well as variations in the initial uranium and thorium isotopic ratios of the precipitated metal oxides. This approach is illustrated using a Fe-Mn crust from Lotab seamount (Marshall Islands, west equatorial Pacific). Here we report uranium and thorium isotopic compositions in five subsamples from the surface of one large 5 cm diameter botyroid of this crust, and from two depth profiles of the outermost rim of the same botyroid. The decrease of ( 234 U) excess /( 238 U) and ( 230 Th/ 232 Th) activity ratio with depth in the two profiles gives mean growth rates, for the last 150 ka, of 7.8 ± 2 mm/Ma and 6.6 ± 1 mm/Ma, respectively. All data points (surface and core samples) but one, define a linear correlation in the Ln ( 230 Th/ 232 Th) - Ln [( 234 U) excess ( 238 U)] diagram. This correlation indicates that for all points the U-Th system remained closed after the Fe-Mn layer precipitated, and that the different samples possessed the same initial Uranium and thorium isotope ratios. Furthermore, these results show that the preserved surface of this Fe-Mn crust may not be the present-day growth surface, and that the thorium and uranium isotopic ratios of seawater in west equatorial Pacific have not changed during the past 150 ka. The initial thorium activity ratio is estimated from the correlation obtained between Ln( 230 Th/ 232 Th) and Ln [( 234 U) excess /( 238 U)

The transport characteristics of {sup 238}U, {sup 232}Th, {sup 226}Ra, and {sup 40}K in the production cycle of phosphate rock

Energy Technology Data Exchange (ETDEWEB)

Jung, Yoon Hee; Lim, Jong Myoung; Ji, Young Yong; Chung, Kun Ho; Kang, Mun Ja [Environmental Radioactivity Assessment Team, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2017-03-15

Phosphate rock and its by-product are widely used in various industries to produce phosphoric acid, gypsum, gypsum board, and fertilizer. Owing to its high level of natural radioactive nuclides (e.g., 238U and 226Ra), the radiological safety of workers who work with phosphate rock should be systematically managed. In this study, 238U, 232Th, 226Ra, and 40K levels were measured to analyze the transport characteristics of these radionuclides in the production cycle of phosphate rock. Energy dispersive X-ray fluorescence and gamma spectrometry were used to determine the activity of 238U, 232Th, 226Ra, and 40K. To evaluate the extent of secular disequilibrium, the analytical results were compared using statistical methods. Finally, the distribution of radioactivity across different stages of the phosphate rock production cycle was evaluated. The concentration ratios of 226Ra and 238U in phosphate rock were close to 1.0, while those found in gypsum and fertilizer were extremely different, reflecting disequilibrium after the chemical reaction process. The nuclide with the highest activity level in the production cycle of phosphate rock was 40K, and the median 40K activity was 8.972 Bq·g−1 and 1.496 Bq·g−1, respectively. For the 238U series, the activity of 238U and 226Ra was greatest in phosphate rock, and the distribution of activity values clearly showed the transport characteristics of the radionuclides, both for the byproducts of the decay sequences and for their final products. Although the activity of 40K in k-related fertilizer was relatively high, it made a relatively low contribution to the total radiological effect. However, the activity levels of 226Ra and 238U in phosphate rock were found to be relatively high, near the upper end of the acceptable limits. Therefore, it is necessary to systematically manage the radiological safety of workers engaged in phosphate rock processing.

Summary of Plutonium-238 Production Alternatives Analysis Final Report

Energy Technology Data Exchange (ETDEWEB)

James Werner; Wade E. Bickford; David B. Lord; Chadwick D. Barklay

2013-03-01

The Team implemented a two-phase evaluation process. During the first phase, a wide variety of past and new candidate facilities and processing methods were assessed against the criteria established by DOE for this assessment. Any system or system element selected for consideration as an alternative within the project to reestablish domestic production of Pu-238 must meet the following minimum criteria: Any required source material must be readily available in the United States, without requiring the development of reprocessing technologies or investments in systems to separate material from identified sources. It must be cost, schedule, and risk competitive with existing baseline technology. Any identified facilities required to support the concept must be available to the program for the entire project life cycle (notionally 35 years, unless the concept is so novel as to require a shorter duration). It must present a solution that can generate at least 1.5 Kg of Pu-238 oxide per year, for at least 35 years. It must present a low-risk, near-term solution to the National Aeronautics and Space Administration’s urgent mission need. DOE has implemented this requirement by eliminating from project consideration any alternative with key technologies at less than Technology Readiness Level 5. The Team evaluated the options meeting these criteria using a more detailed assessment of the reasonable facility variations and compared them to the preferred option, which consists of target irradiation at the Advanced Test Reactor (ATR) and the High Flux Isotope Reactor (HFIR), target fabrication and chemical separations processing at the ORNL Radiochemical Engineering Development Center, and neptunium 237 storage at the Materials and Fuels Complex at INL. This preferred option is consistent with the Records of Decision from the earlier National Environmental Policy Act (NEPA) documentation

Transfer of 40K, 238U, 210Pb, and 210Po from soil to plant in various locations in south of Syria

International Nuclear Information System (INIS)

Al-Masri, M.S.; Al-Akel, B.; Nashawani, A.; Amin, Y.; Khalifa, K.H.; Al-Ain, F.

2008-01-01

Transfer factors of 40 K, 238 U, 210 Pb, and 210 Po from soil to some agriculture crops in various locations in south of Syria (Dara'a and Assuwaydaa districts) have been determined. Soil and vegetable crops (green pepper, cucumber, tomato, and eggplant), legumes crops (lentil, chickpea, and broad bean), fruit trees (apple, grape, and olives) and cereals (barley and wheat) were collected and analyzed for 238 U, 210 Pb, and 210 Po. The results have shown that higher transfer factors (calculated as Bq kg -1 dry wt. plant material per Bq kg -1 dry wt. soil) for 210 Po, 210 Pb and 238 U were observed in vegetable leaves than fruits and cereals leaves; the highest values of transfer factor (TF) for 238 U were found to be 0.1 for straw of chickpea. Transfer factors for 210 Po varied between 2.8 x 10 -2 and 2 in fruits of eggplant and grain of barley, respectively. In addition, several parameters affecting transfer factors of the radionuclides were evaluated. The results can be considered as base values for TF of natural radionuclides in the region

Representación social de "los argentinos", "los españoles", "los latinoamericanos" y "los europeos" en estudiantes universitarios argentinos

OpenAIRE

Néstor Daniel Roselli

2000-01-01

El objetivo de la investigación es descriptivo: producir una caracterización de cómo los estudiantes universitarios argentinos definen subjetivamente a los referidos grupos nacionales ("los "los argentinos", "los españoles" y supranacionales, "los latinoamericanos" y "los europeos"). Sin embargo, no esun mero estudio de estereotipos nacionales. La originalidad consiste en el encuadre metodológico, propio de análisis de las representaciones sociales. Se basa en un análisis estadístico d...

Molecular characterization using ISSR primers of Magnolia mexicana DC. from two regions in Zongolica, Veracruz, Mexico

Directory of Open Access Journals (Sweden)

Jessica M. Medrano-Hernández

2017-01-01

Full Text Available Introducción: Magnolia mexicana DC . es una especie amenazada según la NOM-059-SEMARNAT-2010, situación atribuida a la fragmentación y destrucción del hábitat. No existen estudios sobre la diversidad genética de M. mexicana, a pesar de que es endémica de nuestro país. Objetivo: Evaluar la variabilidad genética en dos poblaciones de M. mexicana mediante marcadores moleculares tipo ISSR. Materiales y métodos: Las colectas provienen de Amatitla y Zapotla en Zongolica, Veracruz. El ADN se extrajo de las hojas jóvenes. Se probaron 55 iniciadores ISSR, se seleccionaron los 10 que produjeron mayor número de bandas con polimorfismo y se amplificaron por PCR. Resultados y discusión: Los iniciadores ISSR mostraron 86 % de polimorfismo. El análisis de agrupamiento, con el método de varianza mínima de Ward, fue capaz de separar las colectas por su procedencia geográfica. El análisis de varianza molecular demostró que la mayor variabilidad (90.88 % se encuentra dentro de cada población. El índice de diversidad de Shannon-Weaver fue de 0.47 y 0.41 para Amatitla y Zapotla, respectivamente. Conclusión: Las poblaciones de M. mexicana no han sufrido cambios en su estructura genética; no hay evidencia, a nivel genético, de alteraciones ocasionadas por la reducción de poblaciones o fragmentación del hábitat.

Isotopic production cross-sections and recoil velocities of spallation-fission fragments in the reaction 238U(1A GeV)+e

CERN Document Server

Pereira, J; Wlazlo, W; Benlliure, J; Casarejos, E; Armbruster, P; Bernas, M; Enqvist, T; Legrain, R; Leray, S; Rejmund, F; Mustapha, B; Schmidt, K.-H; Stéphan, C; Taïeb, J; Tassan-Got, L; Volant, C; Boudard, A; Czajkowski, S; 10.1103/PhysRevC.75.014602

2007-01-01

Fission fragments of 1A GeV 238U nuclei interacting with a deuterium target have been investigatedwith the Fragment Separator (FRS) at GSI (Darmstadt) by measuring their isotopicproduction cross-sections and recoil velocities. The results, along with those obtained recently forspallation-evaporation fragments, provide a comprehensive analysis of the spallation nuclear productionsin the reaction 238U(1A GeV)+d. Details about experiment performance, data reductionand results will be presented.

Calibration for plutonium-238 lung counting at Mound Laboratory

International Nuclear Information System (INIS)

Tomlinson, F.K.

1976-01-01

The lung counting facility at Mound Laboratory was calibrated for making plutonium-238 lung deposition assessments in the fall of 1969. Phoswich detectors have been used since that time; however, the technique of calibration has improved considerably. The current technique of calibrating the lung counter is described as well as the method of error analysis and determination of the minimum detectable activity. A Remab hybrid phantom is used along with an attenuation curve which is derived from plutonium loaded lungs and ground beef absorber measurements. The errors that are included in an analysis as well as those that are excluded are described. The method of calculating the minimum detectable activity is also included

Depth profiling of residual activity of ^{237}U fragments as a range verification technique for ^{238}U primary ion beam

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I. Strašík

2012-07-01

Full Text Available Experimental and simulation data concerning fragmentation of ^{238}U ion beam in aluminum, copper, and stainless-steel targets with the initial energy 500 and 950  MeV/u are collected in the paper. A range-verification technique based on depth profiling of residual activity is presented. The irradiated targets were constructed in the stacked-foil geometry and analyzed using gamma-ray spectroscopy. One of the purposes of these experiments was depth profiling of residual activity of induced nuclides and projectile fragments. Among the projectile fragments, special attention is paid to the ^{237}U isotope that has a range very close to the range of the primary ^{238}U ions. Therefore, the depth profiling of the ^{237}U isotope can be utilized for experimental verification of the ^{238}U primary-beam range, which is demonstrated and discussed in the paper. The experimental data are compared with computer simulations by FLUKA, SRIM, and ATIMA, as well as with complementary experiments.

A dispersive optical model potential for nucleon induced reactions on 238U and 232Th nuclei with full coupling

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Chiba Satoshi

2013-03-01

Full Text Available A dispersive coupled-channel optical model potential (DCCOMP that couples the ground-state rotational and low-lying vibrational bands of 238U and 232Th nuclei is studied. The derived DCCOMP couples almost all excited levels below 1 MeV of excitation energy of the corresponding even-even actinides. The ground state, octupole, beta, gamma, and non-axial bands are coupled. The first two isobar analogue states (IAS populated in the quasi-elastic (p,n reaction are also coupled in the proton induced calculation, making the potential approximately Lane consistent. The coupled-channel potential is based on a soft-rotor description of the target nucleus structure, where dynamic vibrations are considered as perturbations of the rigid rotor underlying structure. Matrix elements required to use the proposed structure model in Tamura coupled-channel scheme are derived. Calculated ratio R(U238/Th232 of the total cross-section difference to the averaged σT for 238U and 232Th nuclei is shown to be in excellent agreement with measured data.

Air Monitoring Leads to Discovery of New Contamination at Radioactive Waste Disposal Site (Area G) at Los Alamos National Laboratory

International Nuclear Information System (INIS)

Kraig, D.H.; Conrad, R.C.

1999-01-01

Air monitoring at Area G, the low-level radioactive waste disposal area at Los Alamos National Laboratory, revealed increased air concentrations of 239 Pu and 241 Am at one location along the north boundary. This air monitoring location is a couple of meters north of a dirt road used to access the easternmost part of Area G. Air concentrations of 238 Pu were essentially unaffected, which was puzzling because the 238 Pu and 239 Pu are present in the local, slightly contaminated soils. Air concentrations of these radionuclides increased about a factor of ten in early 1995 and remained at those levels until the first quarter of 1996. During the spring of 1996 air concentrations again increased by a factor of about ten. No other radionuclides were elevated and no other Area G stations showed elevations of these radionuclides. After several formal meetings didn't provide an adequate cause for the elevations, a gamma survey was performed and showed a small area of significant contamination just south of the monitor location. We found in February, 1995, a trench for a water line had been dug within a meter of so of the air stations. Then, during early 1996, the dirt road was rerouted such that its new path was directly over the unknown contamination. It appears that the trenching brought contaminated material to the surface and caused the first rise in air concentrations and then the rerouting of the road over the contamination caused the second rise, during 1996. We also found that during 1976 and 1977 contaminated soils from the clean-up of an old processing facility had been spread over the filled pits in the vicinity of the air monitors. These soils were very low in 238Pu which explains why we saw very little 238 Pu in the increased air concentrations. A layer of gravel and sand was spread over the contaminated area. Although air concentrations of 239 Pu and 241 Am dropped considerably, the y have not returned to pre-1995 levels

Sensitivity coefficients for the 238U neutron-capture shielded-group cross sections

International Nuclear Information System (INIS)

Munoz-Cobos, J.L.; de Saussure, G.; Perez, R.B.

1981-01-01

In the unresolved resonance region cross sections are represented with statistical resonance parameters. The average values of these parameters are chosen in order to fit evaluated infinitely dilute group cross sections. The sensitivity of the shielded group cross sections to the choice of mean resonance data has recently been investigated for the case of 235 U and 239 Pu by Ganesan and by Antsipov et al; similar sensitivity studies for 238 U are reported

Fission cross sections of {sup 235,238}U and {sup 209}Bi at incident proton energies above 70 MeV

Energy Technology Data Exchange (ETDEWEB)

Obukhov, A I; Rimskij-Korsakov, A A; Eismont, V P [V.G. Khlopin Radium Inst., St. Petersburg (Russian Federation)

1997-06-01

The proton fission cross-section data of {sup 235,238}U and Bi were measured in the V.G. Khlopin Radium Institute over a wide proton energy range. The experimental and calculated data were also compared with experimental neutron values. The proton cross-section of {sup 235,238}U increased up to 60-70 MeV and then decreased. The bismuth proton fission cross-section increased in line with the rise in proton energy up to 1 GeV. (author). 21 refs, 6 figs.

Interaction by known beta cell loci on the association of antihypertensive drug therapies with hyperglycemia in the Framingham Offspring Study

OpenAIRE

Miguel y Yanes, José María de

2013-01-01

Antecedentes: Los polimorfismos de nucleótido simple (SNPs) comunes asociados a función de célula beta y la hipertensión o su tratamiento podrían interaccionar con la variación en el tiempo en la glucosa en ayunas (ΔGA) o la aparición de diabetes mellitus tipo 2 (DM-2). Métodos: Agrupamos datos de 3.471 participantes del Estudio Descendencia de Framingham en 6 períodos de ~4 años (15.852 personas-examen; edad media 52 años, 54% mujeres). Definimos tres exposiciones de hipertensión: 1) hiperte...

Disintegration constant of uranium-238 by spontaneous fission redetermined by glass track method

International Nuclear Information System (INIS)

Lima Medeiros, E. de.

1978-01-01

The disintegration constant of U 238 by spontaneous fission using glass as fission fragment detector was redetermined. A film of natural uranium (UO 3 ) prepared by chemical methods on the glass lamina was used in a long time experience of exposure (about 16 years). The good conditions of sample preparation and storage allow to observe, after chemical etching, fission fragment tracks. (M.C.K.) [pt

MAXI/GSC detection of a hard-to-soft transition of NS-LMXB GS 1826-238

Science.gov (United States)

Nakahira, S.; Mihara, T.; Sugizaki, M.; Serino, M.; Morii, M.; Sugimoto, J.; Takagi, T.; Yoshikawa, A.; Matsuoka, M.; Kawai, N.; Yoshii, T.; Tachibana, Y.; Ueno, S.; Tomida, H.; Kimura, M.; Ishikawa, M.; Nakagawa, Y. E.; Negoro, H.; Nakajima, M.; Fukushima, K.; Onodera, T.; Suzuki, K.; Fujita, M.; Namba, T.; Honda, F.; Yoshida, A.; Sakamoto, T.; Kawakubo, Y.; Ohtsuki, H.; Tsunemi, H.; Uchida, D.; Ueda, Y.; Shidatsu, M.; Kawamuro, T.; Hori, T.; Kawagoe, A.; Tsuboi, Y.; Yamauchi, M.; Morooka, Y.; Yamaoka, K.

2014-06-01

We report on a hard-to-soft spectral transition of an X-ray burster GS 1826-238 detected with MAXI/GSC. This source had been consistently observed in the hard state for more than 25 years since the discovery in 1988 (Tanaka 1989, Barret et al. ...

238,234U contents on Lepomis Cyanellus from San Marcos dam located in a uraniferous area

Science.gov (United States)

Lares, Magaly Cabral; Luna-Porres, Mayra Y.; Montero-Cabrera, María E.; Renteria-Villalobos, Marusia

2014-07-01

Fish species are suitable biomonitors of radioisotopes in aquatic systems. In the present study, it was made the determination of uranium isotopic contents on fish fillet (Lepomis Cyanellus) from San Marcos dam which is located in uranium mineralized zone. Uranium activity concentrations (AC) in fish samples were obtained on wet weight (ww), using liquid scintillation. 238U and 234U AC in fish fillet ranged from 0.0004 to 0.0167 Bq kg-1, and from 0.0013 to 0.0394 Bq kg-1, respectively. The activity ratio (234U/overflow="scroll">238U) in fish fillet ranged from 2.2 to 8.8. Lepomis cyanellus from San Marcos dam shows bioaccumulation factor (FB) of 0.6 L kg-1. The results suggest that the Lepomis Cyanellus in environments with high U contents tends to have a greater bioaccumulation compared to others.

The metrological activity determination of {sup 238} U and {sup 230} Th by gamma spectrometry to industrial fuel-cycle application

Energy Technology Data Exchange (ETDEWEB)

Almeida M, M.C. de; Delgado, J.U.; Poledna, R. [Instituto de Radioprotecao e Dosimetria- IRD/SEMRA, CNEN, Av. Salvador Allende s/n, Recreio, CEP 22780-160, Rio de Janeiro (Brazil)]. e-mail: marcandida@yahoo.com.br

2006-07-01

This work describes the difficulty for determining the activity of {sup 238} U and {sup 230} Th using gamma spectrometry due to the low gamma-ray emission probabilities of 92 and 67 keV, and, mainly, the associated high uncertainties about 13 and 11%, respectively. {sup 230} Th is a {sup 238} U daughter and it is product from uranium mills and refineries. {sup 230} Th decays to {sup 226} Ra and this decay has to be measured because these radionuclides are not in secular equilibrium with their daughter products, besides the gamma-energies have high uncertainties in the emission probabilities. These radionuclides, mostly {sup 238} U, are important in the nuclear fuel-cycle, since the mining of uranium ore, where the nominal isotopic content of natural uranium is 99.27% of {sup 238} U, until the irradiated fuel reprocessing, where this isotope, a fertile material, is recovered to be used again. The uranium and thorium are considered safeguarded nuclear materials and the metrology tries to calibrate and standardize these materials to improve the activity determination techniques applied in different fuel-cycle scopes. The essential characteristics of the safeguarded materials are low gamma energies (less than 100 keV) and emission probabilities but with high uncertainties. In this way, the metrology can contribute to homeland security defense against illicit nuclear trafficking with the identification and quantification of the safeguarded radionuclides such as uranium and thorium, using specific gamma window energy and high resolution planar or coaxial germanium detector. The efficiency curve is obtained from the reference source spectrum considering the photopeak areas corresponding the standard activities. This curve depends on radiation energy, sample geometry, photon attenuation (sample absorption and material absorption between sample-detector), dead time and sample-detector position. The metrological activity determinations of {sup 238} U solid sources, and of

El polimorfismo (CAGn del gen ATXN2, nuevo marcador de susceptibilidad para diabetes mellitus tipo 2

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Luis J. Flores-Alvarado

Full Text Available RESUMEN Objetivo Estimar si hay asociación del repetido (CAGn del gen ATXN2 en población mexicana con diabetes mellitus (DM tipo 2. Métodos Estudio epidemiológico de casos y controles. Se incluyeron personas sanas y personas diabéticas. La detección de la expansión (CAGn se realizó por reacción en cadena de la polimerasa (PCR-punto final. Los productos de PCR se analizaron mediante electroforesis (PAGE al 8% y tinción con nitrato de plata. Resultados La distribución de alelos del trinucleótido (CAGn en la población analizada resultó similar a la reportada en el centro del país. El alelo más frecuente es el de 22 repetidos; sin embargo, hay asociación con los portadores de los repetidos largos dentro del rango normal con diabetes. Conclusiones Los resultados sugieren que el repetido (CAGn del gen de ATXN2 podría ser un factor causal de DM tipo 2.

Neutron Induced Capture and Fission Processes on 238U

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Oprea Cristiana

2016-01-01

Full Text Available Nuclear data on Uranium isotopes are of crucial interest for new generation of nuclear reactors. Processes of interest are the nuclear reactions induced by neutrons and in this work mainly the capture and the fission process on 238U will be analyzed in a wide energy interval. For slow and resonant neutrons the many levels Breit – Wigner formalism is necessary. In the case of fast and very fast neutrons up to 200 MeV the nuclear reaction mechanism implemented in Talys will be used. The present evaluations are necessary in order to obtain the field of neutrons in the design of nuclear reactors and they are compared with experimental data from literature obtained from capture and (n,xn processes.

Measurement of the 235U/238U fission cross section ratio in the 235U fission neutron spectrum

International Nuclear Information System (INIS)

Azimi-Garakani, D.; Bagheri-Darbandi, M.

1983-06-01

Fission cross section ratio of 235 U to 238 U has been measured in the fast neutron field generated by the 235 U fission plate installed on the thermal column of the Tehran Research Reactor (TRR) with a Makrofol solid state nuclear track detector. The experiments were carried out with a set of total six enriched 235 U and depleted 238 U deposits with different masses and Makrofol films of 0.025mm and 0.060mm thicknesses. The chemically etched tracks were counted by an optical microscope. No significant differences were observed with the thin and the thick films. The results showed that the average fission cross section ratio is 3.83+-0.25. (author)

Fabrication of 238Pu based sources for energy micro-generator

International Nuclear Information System (INIS)

Barthelemy, Pierre; Boucher, Rene

1969-04-01

The authors describe the fabrication of sources of 238 Pu. The plutonium-scandium alloy is obtained by arc fusion in its delta phase. This alloy is chosen for its excellent malleability, and is rolled at 20 C. Pellets are then cut and decontaminated. Each pellet is then placed in a first tantalum sheath which is welded by electronic bombardment. A second sheath in platinum-iridium is placed around the first one, and also welded by using the same welding process. The so-fabricated sources are to feed energy thermal-electric conversion micro-generators which are supposed to operate tens of years in medical applications as organ stimulators [fr

238Pu based energy micro-generation sources for medical applications

International Nuclear Information System (INIS)

Boucher, Rene

1968-10-01

Pace-makers are frequently implanted in the human body. The existing apparatus are, actually, equipped with chemical piles with a lifetime of about 15 months. The use of 238 Pu will provide a pace-maker with an autonomy of 10 years at least. Principal problems of security due to the use of plutonium are considered. It is advisable to improve the properties of pure plutonium by small additions of elements such as cerium, scandium, indium, gallium or americium. A number of the most important properties for a pace-maker source are presented. Finally, the fabrication and canning of the source are surveyed. (author) [fr

Application of 234U/238U isotope ratio data for the study of geochemical problems associated with local water sources from Aguas da Prata (SP, Brazil)