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Sample records for fibra optica compuesto

  1. Desarrollo de materiales compuestos avanzados basados en fibras de carbono para la industria aeroespacial

    OpenAIRE

    Rodriguez, Exequiel Santos

    2015-01-01

    En este trabajo se estudia el desarrollo de materiales compuestos de matriz polimérica reforzados con fibras de carbono para aplicaciones que presentan solicitaciones severas. Este es el caso de la industria aeroespacial, que utiliza componentes en cohetes y aeronaves que se ven sometidos a altas solicitaciones mecánicas y están expuestos a las altas temperaturas. Es por ello que se estudiaron materiales para diversas aplicaciones basados en fibras de carbono: preimpregnados de fibras y resin...

  2. Fibras vegetales colombianas como refuerzo en compuestos de matriz polimérica

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    José Luis Suárez Castañeda

    2017-01-01

    Full Text Available Contexto: Se realizó una búsqueda local de tejidos de fibras vegetales para determinar la composición de los grupos funcionales y morfología de su superficie antes y después de un tratamiento alcalino con miras a su empleo como refuerzo en compuestos de matriz polimérica. Método: La búsqueda se desarrolló dentro del área metropolitana del Valle de Aburrá, Colombia. Las fibras se trataron por inmersión en NaOH disuelto al 6 % w/v por 48 horas, seguida por una neutralización en ácido acético al 1 % v/v por una hora. Posteriormente fueron secadas a 60 °C por 24 horas. Las técnicas empleadas para los análisis fueron la espectroscopía infrarroja por transformada de Fourier (FTIR y la microscopía electrónica de barrido (SEM. Resultados: Se seleccionaron tejidos de fique, yute, corteza de coco, lino y algodón. Los análisis FTIR muestran una tendencia a la disminución de ácidos grasos, hemicelulosas, ligninas y enlaces β en la superficie de las fibras, mientras que las imágenes SEM demuestran la remoción de impurezas, la exposición de rugosidades y la creación de espacios interfibrales. Conclusiones: El tratamiento alcalino podría favorecer el mecanismo de anclaje del polímero termofijo a la superficie de las fibras y la creación de enlaces entre las moléculas polares de las fibras y el polímero termofijo, disminuyendo el deslizamiento relativo entre matriz y refuerzo durante la aplicación de cargas.

  3. ESTUDIO DE LA RESISTENCIA MECÁNICA DE MATERIALES COMPUESTOS POLIMÉRICOS REFORZADOS CON FIBRAS DE CARBONO

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    Enrique Rocha-Rangel

    2011-01-01

    Full Text Available Materiales compuestos hechos de una resina epóxica reforzada con diferentes contenidos de fibra de carbono, fueron preparados por dos técnicas de laminación diferentes. Se aplicó 1 Kg/cm2 de presión en los laminados, mientras, que otros laminados se sometieron a un vacío de 1 atm. De los resultados se tiene que las resistencias a la flexión y tensión de los compósitos son mejoradas con el aumento en el contenido de fibra en los mismos. Los compósitos resultantes presentan un mejor comportamiento mecánico bajo esfuerzos de tensión que cuando lo hacen bajo esfuerzos de flexión, debido a que en flexión las fibras se rompen eventualmente, provocando que el material falle a bajos valores de esfuerzo. Cuando los materiales compuestos son sometidos a tensión, las fibras trasmiten los esfuerzos entre ellas y el material falla hasta que se acumula la energía necesaria para romper todas las fibras de una sola vez.

  4. Application of unimodal optic fiber to communications among electric substations; Aplicacion de fibra optica unimodal a comunicaciones entre subestaciones electricas

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Pinon, Fernando; Hernandez Juarez, Taide [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-07-01

    The utilization of the unimodal fiber optics technology in the electric power systems, represents one of the best communication options because of its multiple advantages, that results in a better coordination of the technical and administrative activities, needed to carry the electric energy from its generation site to the most remote locations. In this document a study, in accordance with the available options for the design of communication systems via unimodal optic fiber, is presented. With this technology, ties of more than 100 kilometers without the need of repeating stations, can be made. [Espanol] La utilizacion de la tecnologia de fibra optica unimodal en los sistemas electricos de potencia representa una de las mejores alternativas de comunicacion por sus multiples ventajas que se traducen en una mejor coordinacion de las acitividades tecnicas y administrativas necesarias para llevar la energia electrica desde el lugar de generacion hasta los puntos mas distantes. En este documento se presenta un estudio de acuerdo a las opciones disponibles para el diseno de sistemas de comunicacion por fibra optica unimodal. Con esta tecnologia se pueden realizar enlaces mayores que 100 km sin necesidad de repetidores.

  5. Evaluación de las propiedades de materiales compuestos fabricados a partir de fibras semiquímicas de Leucaena collinsii y polipropileno

    OpenAIRE

    Granda Garcia, Luis Angel

    2016-01-01

    La presente tesis estudia el efecto que produce reforzar una fibra semiquímica de Leucaena collinsii en las propiedades mecánicas, térmicas y de sorción de agua de materiales compuestos de polipropileno. Se obtienen probetas de materiales compuestos con distinto contenido de refuerzo y se estabilizan en una cámara climática durante 48 horas antes de ser ensayadas a tracción, flexión e impacto, y se analiza la morfologia de la fractura mediante SEM. Posteriormente se estudian sus propiedad...

  6. TECNOLOGIA A FIBRA OPTICA: UNIVERSIDAD NACIONAL DE COLOMBIA SEDE MEDELLIN, "UN REFERENTE LATINOAMERICANO"

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    RODRIGO ACUÑA

    2008-01-01

    Full Text Available En este artículo se muestran algunos resultados de las investigaciones realizadas por el grupo de Fotónica y Opto-electrónica de la Universidad Nacional de Colombia, Sede Medellín. Se hace una breve reseña de la creación del grupo y se describen las principales aplicaciones desarrolladas, las cuales convierten al grupo en un referente Latinoamericano en el área. Se ilustran aplicaciones de las redes de Bragg en fibra óptica en sensores, simulaciones computacionales de guías de onda ópticas y la construcción de fuentes de luz láser a fibra óptica.

  7. Degradación de los módulos elásticos transversal y de cortadura en materiales compuestos con refuerzo de fibra continua de carbono sometidos a fatiga

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    Revuelta, D.

    2004-04-01

    Full Text Available Fatigue failure in continuous fiber composite materials is caused in first place by matrix cracks that propagate along the fiber direction. It is expected that the defined crack orientation produced an anisotropic degradation of the laminate elastic properties. This work characterizes the degradation suffered by the transverse elastic modulus of a graphite-epoxy laminate subjected to fatigue loads, concluding that the elastic modulus changes drastically from a determined damage threshold, decaying according to a quadratic law.

    La rotura a fatiga en materiales compuestos con refuerzo de fibra continua es debida en primera instancia a la aparición de grietas en la matriz que se propagan en la dirección paralela a la fibra. Es de esperar que la orientación definida de estas grietas produzca una degradación anisótropa de las propiedades elásticas de la lámina. Este trabajo caracteriza la degradación que experimenta el módulo elástico en la dirección perpendicular a la fibra de un material compuesto grafito-epoxi sometido a cargas de fatiga, hallándose que el módulo elástico sufre cambios drásticos a partir de un determinado umbral de daño, y decayendo a partir de ese punto según una ley cuadrática.

  8. Laser of optical fiber composed by two coupled cavities: application as optical fiber sensor; Laser de fibra optica compuesto por dos cavidades acopladas: aplicacion como sensor de fibra optica

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez S, R.A.; Kuzin, E.A.; Ibarra E, B. [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), A.P. 51 y 216, 72000 Puebla (Mexico); May A, M. [Universidad Autonoma del Carmen (UNACAR) Av. 56 No. 4 por Av. Concordia, Campeche (Mexico); Shlyagin, M.; Marquez B, I. [Centro de Investigacion Cientifica y de Ensenanza Superior de Ensenada (CICESE), 22860 Ensenada, Baja California (Mexico)]. e-mail: ravsa100@hotmail.com

    2004-07-01

    We show an optical fiber laser sensor which consist of two cavities coupled and three fiber Bragg gratings. We used one Bragg grating (called reference) and two Bragg gratings (called sensors), which have the lower reflection wavelength. The reference grating with the two sensors grating make two cavities: first one is the internal cavity which has 4230 m of length and the another one is the external cavity which has 4277 m of length. Measuring the laser beating frequency for a resonance cavity and moving the frequency peaks when the another cavity is put in resonance, we prove that the arrangement can be used as a two points sensor for determining the difference of temperature or stress between these two points. (Author)

  9. Desarrollo de un material compuesto de fibras de henequén utilizando una matriz termofija//Development of Composite with Henequen´s fibres and termofix matrix

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    Angel‐A. Rodríguez‐Soto

    2014-08-01

    Full Text Available En este trabajo fue obtenida la influencia de la proporción másica de las fibras de henequén como refuerzo sobre las propiedades mecánicas de resistencia a la tracción y al impacto de un material compuesto de matriz polimérica termoestable. Fueron encontradas muy semejantes, física y químicamente las fibras de dos regiones. Se analizaron las probetas mediante interferometría digitalpara detectar la presencia de defectos y se observaron las zonas de ruptura mediante microscopía electrónica de barrido. Fue determinado que el aumento de la inclusión de las fibras como refuerzoen el material aumenta las propiedades estudiadas llegando a su máximo en un 20 % de relación másica fibra-matriz. Se observó un aumento máximo del 53 % en la resistencia a la tracción y un aumento máximo del 88 % en el impacto respecto a la matriz pura.Palabras claves: PRF: plásticos reforzados con fibras, fibras naturales, interferometría digital.______________________________________________________________________________AbstractIn this work was obtained the influence of the mass ratio of the henequen’s fibers as reinforcing over the mechanical properties in traction an impact resistance of the composite with polymeric thermosetting matrix. Was found very similar physics and chemically, fibers from two regions of the country. Was analyzed the samples using digital interferometry searching for defects and was observed the region of rupture using electronic microscopy of sweeping. Was determined that theincrease of the inclusion of the fiber as reinforcement in this material cause the increase of the study properties, raising a maximum over the 20 % of the mass ratio in the relation fiber-matrix. Was observed an increasing over the 53 % in the resistance to traction and over 88 % in the impact resistance compare to the matrix alone.Key words: FRP: fiber reinforced plastics,natural fibers, digital interferometry.

  10. Interacción entre el aluminio fundido y las fibras de carbono recubiertas con cobre y níquel en materiales compuestos de matriz metálica

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    Ureña, A.

    2004-04-01

    Full Text Available Aluminium Matrix Composites (AMC reinforced with carbon fiber (Cf show good mechanical properties and great capability of autolubrication. However, carbon fibers have poor wetting and react with molten aluminium producing aluminium carbide (Al4C3, that degrades the composite mechanical properties. In order to improve the wetting and to avoid the reaction between Cf and aluminium, the fibers have been coated with a thin layer of Cu and Ni, using an electroless process. AMC have been made using uncoated carbon fibers and Cu or Ni coated ones. The matrix-reinforcement interface has been analysed using SEM / EDX. Nanoindentation mechanical tests have been carried out to evaluate mechanical properties of the matrix-reinforcement interface.

    Los materiales compuestos de matriz de aluminio (AMC reforzados con fibra de C (Cf presentan unas buenas propiedades mecánicas y una gran capacidad de autolubricación. Sin embargo, las fibras de C tienen una pobre mojabilidad y reaccionan con el aluminio fundido formando Al4C3 en la intercara matriz-refuerzo, lo que provoca la degradación de las propiedades mecánicas del material. Para aumentar la mojabilidad y prevenir la reacción, se han recubierto las fibras con una fina capa de Cu o de Ni, utilizando el proceso de “electroless”. Se han fabricado AMC utilizando Cf sin recubrir y recubiertas de Cu o Ni. Se ha estudiado la intercara matriz-refuerzo mediante SEM / EDX y se han realizado ensayos mecánicos de nanoindentación para evaluar las propiedades mecánicas de la intercara matriz-refuerzo.

  11. Static and cyclic performance of cementitious composites reinforced with glass-fibres; Rendimiento estático y cíclico de compuestos cementantes reforzados con fibras de vidrio

    Energy Technology Data Exchange (ETDEWEB)

    Arabi, N.

    2018-04-01

    This paper concerns an experimental study of the influence of short glass-fibres randomly oriented of a reinforced cement-based composite on the mechanical behaviour. The matrix material parameters used are: cement/sand ratio and water/cement ratio fixed at 0.5; the glass-fibre content (0%, 0.5%, 1.0%, 1.5%, 2% and 2.5%) and fibre lengths (3, 6 and 12 mm). Composites mechanical characterisation under static behaviour at flexural and compression tests, shows that the reinforcement effect is beneficial only in flexural case. A synergy (matrix-reinforcement) was observed when fibre length of 12 mm is used with application rate of 2% in flexural. The fatigue behaviour determined by Wöhler plots (stress-number of cycles to rupture), derived from experimental results; showed a large results dispersion which is attributed to many causes initiating this damage. The cyclic tests illustrate brittle character of these materials; even with low-amplitude cycles of loading no adaptation of these materials can be reported. [Spanish] Este trabajo aborda el estudio experimental de la influencia de fibras de vidrio cortas orientadas al azar sobre el comportamiento mecánico de un composite reforzado de base cemento. Los parámetros de la matriz utilizados son: relación cemento/arena y relación agua/cemento fijada en 0,5; el contenido de fibra de vidrio (0%, 0,5%, 1,0%,1,5%, 2% y 2,5%) y longitudes de fibra (3, 6 y 12 mm). Los resultados mecánicos de estos compuestos bajo comportamiento estático (flexión y compresión), muestran que el efecto de refuerzo es beneficioso unicamente a flexión. Se observó una sinergia (refuerzo de la matriz) cuando se usó la fibra de 12 mm con una tasa de aplicación del 2% en flexión. El comportamiento a fatiga determinado por las curvas de Wöhler (número de ciclos hasta la rotura), derivado de los resultados experimentales; mostró una gran dispersión de resultados que se atribuye a las muchas causas que pueden iniciar este daño. Las

  12. Infiltración de materiales de refuerzo en el comportamiento frente a la oxidación y propiedades mecánicas en materiales compuestos de carbono reforzados con fibra de carbono

    Directory of Open Access Journals (Sweden)

    Jiménez, J. M.

    2007-08-01

    Full Text Available In the present study, attention was focused on the adaptation of different methods in order to incorporate reinforcement materials just like SiC and B4C to carbon fiber reinforced carbon matrix (C/C composites. Hot petroleum pitch impregnation and also at room temperature, and toluene were used as drivers to incorporate reinforcement materials and oxidation inhibitors, just like B2O3, H3BO3 and B4C to (C/C matrix. Hermetic crucibles and graphite have been used in order to obtained carbonization process. Oxidizing atmospheres were used in order to improve the oxidation matrix after the carbonization process. Different methods of infiltration have been evaluated in order to test which of these produce bigger increment on mechanical properties and oxidation protection of the final materials. The different tested materials were studied by means of techniques like scanning electron microscopy (SEM and micro-analysis by energy dispersive spectroscopy (EDS. Results of flexural test were finally compared.

    El objeto del presente trabajo consiste en adecuar distintos métodos para la incorporación de materiales de refuerzo como el SiC y B4C a materiales compuestos de carbono, reforzados con fibra de carbono. Se utilizaron breas de impregnación de petróleo (en frío y en caliente y tolueno como vehículos para la incorporación de los materiales de refuerzo y materiales inhibidores de oxidación como B2O3, H3BO3 y B4C a las matrices de C/C. Se utilizaron crisoles herméticos con grafito en polvo en su interior para obtener la carbonización de las muestras. Se emplearon atmósferas fuertemente oxidantes para provocar la oxidación y degradación de la matriz compuesta tras el proceso de carbonización. También se evaluaron cuáles de los métodos ensayados producen un mayor incremento de las propiedades mecánicas y protección contra la oxidación de los materiales finales obtenidos. Los distintos materiales ensayados fueron estudiados mediante

  13. Cuadro de bicicleta en material compuesto

    OpenAIRE

    Solana Rodríguez, Alberto

    2014-01-01

    Este proyecto trata sobre el diseño y el cálculo de un cuadro de bicicleta de carretera realizado en materiales compuestos. Esta en particular va a ser fibra de carbono ya que es la más utilizada en el mundo de la competición actualmente, y cada vez más en el resto de bicicletas. El principal objetivo es realizar una inmersión en el campo de los materiales compuestos, cuyas propiedades son bastante diferentes si se comparan con otros que han sido utilizados en diversas asign...

  14. Influencia de la distribución de las fibras en la conductividad térnnica de materiales compuestos con matrices de aleaciones de titanio y de magnesio

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    Alcaraz, D.

    2005-12-01

    Full Text Available Metal matrix composites are materials with an increasing use in industrial applications. Generally, the estimation of their thermal conductivity does not take into account the type of reinforcements distribution within the matrix. By applying the Network Simulation Method, a 2-D network model is designed and simulated to determinate precise numerical values of thermal conductivity of composites with random distributions. The proposed model is applied to titanium and magnesium matrix composites reinforced with different types of continuous fibers.

    Los "composites" de matriz metálica son materiales de uso creciente en distintas aplicaciones industriales. En general, la determinación de su conductividad térmica no considera el tipo de distribución de los refuerzos en el seno de las matrices. Aplicando el Método de Redes, se diseña un modelo (2D cuya simulación numérica permite obtener valores precisos de conductividad en "composites" con distribuciones aleatorias. El modelo se aplica a "composites" con matrices de aleaciones de titanio y magnesio reforzados con diferentes tipos de fibras continuas.

  15. compuestos fenólicos

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    Yolanda González García

    2005-01-01

    Full Text Available En este trabajo se presenta una revisión bibliográfica que tiene como objetivo identificar y analizar alternativas de aprovechamiento del bagazo de Agave tequilana Weber var. Azul. Se proponen dos líneas de investigación para obtener productos de valor agregado a partir de este residuo: 1utilización como fuente de carbono de bajo costo para la producción de biopolímeros y carbohidrasas, con bacterias celulolíticas del género Microbulbifer, Marinobacterium y Sagittula; 2obtención de compuestos fenólicos a partir de la lignina presente en sus fibras. Se concluye, que el bagazo de agave tequilero es un material viable para ser usado como substrato en procesos fermentativos, por lo que existen grandes oportunidades de investigación para desarrollar procesos de bioconversión técnicamente factible, eficiente y económicamente atractivo

  16. "Estudio tribologico de aceros para moldes. Aplicacion al moldeo por inyeccion de polibutilentereftalato reforzado con fibra de vidrio"

    Science.gov (United States)

    Martinez Mateo, Isidoro Jose

    fabricacion del molde, tienen una gran influencia sobre su comportamiento en servicio a lo largo de la vida util del molde. En la primera parte del presente estudio, a partir de ensayos punzon sobre disco, se ha determinado la relacion entre la resistencia al desgaste y la dureza de aceros para moldes obtenidos a partir de bloques de gran espesor, estudiando los principales mecanismos de desgaste que tienen lugar. A continuacion, con el fin de determinar el dano superficial que sufren los aceros para moldes en condiciones reales de inyeccion, se han estudiado distintos tipos de aceros utilizados comercialmente en moldes de inyeccion de polimeros y materiales compuestos, seleccionando las condiciones de operacion para determinar la variacion de la rugosidad superficial del acero en funcion del material inyectado, del numero de operaciones sucesivas de inyeccion y de la orientacion del flujo de inyeccion, mediante tecnicas de perfilometria optica y microscopia electronica de barrido. Ademas del dano superficial sufrido por el acero con el numero de piezas inyectadas, tambien se ha determinado la evolucion de la rugosidad superficial de los materiales inyectados, polibutilentereftalato (PBT) puro y materiales compuestos derivados de PBT por adicion de un 20 o un 50% en peso de fibra de vidrio. En el caso de las piezas inyectadas, se ha caracterizado su microestructura en funcion del flujo de inyeccion y de la densidad de fibra, se han determinado sus propiedades termicas y dinamico-mecanicas, asi como la variacion de la rugosidad superficial de las piezas inyectadas con el numero de operaciones de inyeccion y con la geometria de las distintas secciones de las piezas. Finalmente, se ha evaluado la resistencia a la abrasion de PBT reforzado con un 50% de fibra, en funcion del numero de piezas inyectadas y de la direccion de rayado con respecto a la orientacion del flujo de inyeccion.

  17. Hydrocephalus in neuromyelitis optica

    OpenAIRE

    Clardy, Stacey L.; Lucchinetti, Claudia F.; Krecke, Karl N.; Lennon, Vanda A.; O'Toole, Orna; Weinshenker, Brian G.; Boyd, Clara D.; Krieger, Stephen; McGraw, Corey; Guo, Yong; Pittock, Sean J.

    2014-01-01

    A majority of patients with neuromyelitis optica (NMO) spectrum disorders (NMOSD) have MRI brain abnormalities, some of which are “NMO-typical” with localization in aquaporin 4 (AQP4)–rich circumventricular and periaqueductal regions.1 Although uncommon in adult patients, symptomatic brain involvement occurs in approximately 50% of NMO–immunoglobulin G (IgG) seropositive children. Here we report the clinical characteristics, type, and frequency of hydrocephalus in NMOSD.

  18. Spectrum of pediatric neuromyelitis optica.

    Science.gov (United States)

    Lotze, Timothy E; Northrop, Jennifer L; Hutton, George J; Ross, Benjamin; Schiffman, Jade S; Hunter, Jill V

    2008-11-01

    Our goal was to describe the spectrum of clinical phenotypes, laboratory and imaging features, and treatment in pediatric patients with neuromyelitis optica. The study consisted of a retrospective chart review of patients followed in a pediatric multiple sclerosis center with a diagnosis of neuromyelitis optica spectrum disorder. Nine patients with neuromyelitis optica spectrum disorders were included, all of whom were female. There were 4 black children, 2 Latin American children, 2 white children, and 1 child of mixed Latin American/white heritage. Median age at initial attack was 14 years (range: 1.9-16 years). Median disease duration was 4 years (range: 0.6-9 years). Tests for neuromyelitis optica immunoglobulin G were positive for 7 patients. Eight patients had transverse myelitis and optic neuritis, and 1 patient had longitudinally extensive transverse myelitis without optic neuritis but had a positive neuromyelitis optica immunoglobulin G antibody titer. Cerebral involvement on MRI was found in all subjects, 5 of whom were symptomatic with encephalopathy, seizures, hemiparesis, aphasia, vomiting, or hiccups. Immunosuppressive therapy reduced attack frequency and progression of disability. Pediatric neuromyelitis optica has a diverse clinical presentation and may be difficult to distinguish from multiple sclerosis in the early stages of the disease. The recognition of the broad spectrum of this disease to include signs and symptoms of brain involvement is aided by the availability of a serum biomarker: neuromyelitis optica immunoglobulin G. Early diagnosis and immunosuppresive treatment may help to slow the accumulation of severe disability.

  19. Immunotherapy of Neuromyelitis Optica

    Science.gov (United States)

    2013-01-01

    Neuromyelitis optica (NMO) is a chronic inflammatory disease of the central nervous system that affects the optic nerves and spinal cord resulting in visual impairment and myelopathy. There is a growing body of evidence that immunotherapeutic agents targeting T and B cell functions, as well as active elimination of proinflammatory molecules from the peripheral blood circulation, can attenuate disease progression. In this review, we discuss the immunotherapeutic options and the treatment strategies in NMO. We also analyze the pathogenic mechanisms of the disease in order to provide recommendations regarding treatments. PMID:24455211

  20. Comportamiento [del] tanque de material compuesto ante cargas dinámicas

    OpenAIRE

    Artero Guerrero, José Alfonso

    2010-01-01

    Este proyecto fin de carrera analiza los impactos de fragmento a alta velocidad sobre estructuras de material compuesto que contienen líquidos. En este proyecto se estudia la vulnerabilidad de la estructura cuando está fabricada en material compuesto. Las excelentes propiedades que tienen los plásticos reforzados de fibras de carbono en cuanto a baja densidad y alta resistencia mecánica los sitúan en una situación clave para desarrollarse como material estructural en fabricación de aviones. E...

  1. INTRODUCTION TO ACTA OPTICA SINICA

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Acta Optica Sinica is a scientific periodical on optics,sponsored by Chinese Optical Society, jointly undertaken by Shanghai Institute of Optics and Fine Mechanics,Changchun Institute of Optics, Fine Mechanics and Physics,the Chinese Academy of Sciences, monthly,first published in 1981. The chief editor is Professor Xu Zhizhan, Academician of the Chinese Academy of Sciences. Now Acta Optica Sinica is a source periodical of the following international index periodicals: SA,CA,EI and PЖ.

  2. [Topics of neuromyelitis optica].

    Science.gov (United States)

    Miyamoto, Katsuichi

    2014-01-01

    Neuromyelitis optica (NMO) has been revealed the difference in the pathology of multiple sclerosis since the anti-aquaporin 4 (AQP4) antibody associated with NMO has been found. The clinical epidemiological study has been reviewed, NMO-related patient number in Japan is estimated to be about 4400 people. The antibody-positive patients against myelin-oligodendrocyte glycoprotein (MOG) are present in anti-AQP4 antibody-negative NMO patients. These patients have a characteristic with high frequency of optic neuritis and good response to therapy. In addition, by research in recent years, a new treatment such as anti-IL-6 therapy or anti-complement therapy has been attempted to NMO.

  3. Neuromyelitis Optica Spectrum Disorders.

    Science.gov (United States)

    Akaishi, Tetsuya; Nakashima, Ichiro; Sato, Douglas Kazutoshi; Takahashi, Toshiyuki; Fujihara, Kazuo

    2017-05-01

    Neuromyelitis optica (NMO) is clinically characterized by severe optic neuritis and transverse myelitis, but recent studies with anti-aquaporin-4-antibody specific to NMO have revealed that the clinical spectrum is wider than previously thought. International consensus diagnostic criteria propose NMO spectrum disorders (NMOSD) as the term to define the entire spectrum including typical NMO, optic neuritis, acute myelitis, brain syndrome, and their combinations. NMOSD is now divided into anti-aquaporin-4-antibody-seropositive NMOSD and -seronegative NMOSD (or unknown serostatus). MR imaging and optical coherence tomography are indispensable in the diagnosis and evaluation of NMOSD. This article reviews the clinical and MR imaging findings of anti-aquaporin-4-antibody-seropositive and anti-myelin oligodendrocyte glycoprotein-antibody-seropositive NMOSD. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Filtrado digital compuesto

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    José de Jesús Medel Juárez

    2013-01-01

    Full Text Available En este trabajo se describen las características de operación de un Filtro Digital Compuesto, el cual está formado por dos estimadores que intervienen en el filtro de Kalman; el primero de ellos corresponde al gradiente estocástico para obtener la función de transición y el segundo, ajusta la ganancia del proceso de innovación por medio de la lógica difusa. En el proceso de filtrado se cuenta con restricciones de tiempo para que su respuesta ocurra antes de que el sistema de referencia cambie a otro estado. Los resultados obtenidos están desarrollados formalmente a lo largo del documento. Se propone un Modelo Auto-regresivo de Promedios Móviles (MARPM (1,1 como sistema de referencia. El algoritmo de filtrado fue desarrollado con el programa MatLab® obteniendo las gráficas de su operación, convergencia y respuesta. Concluyendo con un pequeño análisis de los resultados.

  5. Aquaporin 4 and neuromyelitis optica

    Science.gov (United States)

    Papadopoulos, Marios C; Verkman, A S

    2013-01-01

    Neuromyelitis optica is an inflammatory demyelinating disorder of the CNS. The discovery of circulating IgG1 antibodies against the astrocyte water channel protein aquaporin 4 (AQP4) and the evidence that AQP4-IgG is involved in the development of neuromyelitis optica revolutionised our understanding of the disease. However, important unanswered questions remain—for example, we do not know the cause of AQP4-IgG-negative disease, how astrocyte damage causes demyelination, the role of T cells, why peripheral AQP4-expressing organs are undamaged, and how circulating AQP4-IgG enters neuromyelitis optica lesions. New drug candidates have emerged, such as aquaporumab (non-pathogenic antibody blocker of AQP4-IgG binding), sivelestat (neutrophil elastase inhibitor), and eculizumab (complement inhibitor). Despite rapid progress, randomised clinical trials to test new drugs will be challenging because of the small number of individuals with the disorder. PMID:22608667

  6. Neuromyelitis optica and multiple sclerosis

    DEFF Research Database (Denmark)

    Bennett, J. L.; de Seze, J.; Lana-Peixoto, M.

    2015-01-01

    Neuromyelitis optica (NMO) is an inflammatory autoimmune disease of the central nervous system that preferentially targets the optic nerves and spinal cord. The clinical presentation may suggest multiple sclerosis (MS), but a highly specific serum autoantibody against the astrocytic water channel...

  7. Neuromyelitis Optica Immunoglobulin G in a Child

    OpenAIRE

    Hudson, Lynsee A.; Bernard, Timothy J.; Tseng, Brian S.; Miller, Bradford R.; Corboy, John R.

    2006-01-01

    Neuromyelitis optica or Devic’s syndrome is an uncommon demyelinating disorder that preferentially attacks the spinal cord and optic nerves. Although it is well described in adults, childhood neuromyelitis optica has rarely been reported in the literature and is frequently misdiagnosed as severe multiple sclerosis. Recently, a serum immunoglobulin G test for neuromyelitis optica has become available which may clarify and accelerate the diagnosis. This report describes a child with recurrent m...

  8. Progressive cerebral atrophy in neuromyelitis optica.

    Science.gov (United States)

    Warabi, Yoko; Takahashi, Toshiyuki; Isozaki, Eiji

    2015-12-01

    We report two cases of neuromyelitis optica patients with progressive cerebral atrophy. The patients exhibited characteristic clinical features, including elderly onset, secondary progressive tetraparesis and cognitive impairment, abnormally elevated CSF protein and myelin basic protein levels, and extremely highly elevated serum anti-AQP-4 antibody titer. Because neuromyelitis optica pathology cannot switch from an inflammatory phase to the degenerative phase until the terminal phase, neuromyelitis optica rarely appears as a secondary progressive clinical course caused by axonal degeneration. However, severe intrathecal inflammation and massive destruction of neuroglia could cause a secondary progressive clinical course associated with cerebral atrophy in neuromyelitis optica patients. © The Author(s), 2015.

  9. Mejoramiento de las propiedades de tensión en WPC de LDPE: HIPS/fibra natural mediante entrecruzamiento con DCP

    Directory of Open Access Journals (Sweden)

    Arnoldo Emilio Delgado Tobón

    2014-06-01

    Full Text Available Fibra de Retamo Liso (telinemonspessulana fue mezclada en una matriz polimérica formada por: polietileno de baja densidad (LDPE y poliestireno de alto impacto (HIPS en relación 70:30 respectivamente. La fibra natural fue sometida a reducción de tamaño entre 1700 y 850 µm; se le realizó tratamiento superficial de mercerización; el contenido de humedad fue 0,17%. El análisis termo gravimétrico (TGA muestra que la fibra tratada tiene estabilidad de 200,53 °C. La elaboración del compuesto se realizó en mezclador interno y la técnica de obtención de las probetas fue mediante moldeo por compresión. Se evaluó el efecto del agente entrecruzante peróxido de dicumilo (DCP en compuestos con varios porcentajes de fibra: 0; 10; 25; 50 phr. La adición de DCP (1 phr en los compuestos, mejora significativamente las propiedades de tensión con respecto a similares concentraciones de fibra; sin embargo, esta diferencia en los valores de las propiedades disminuye progresivamente cuando la cantidad de fibra se aproxima a 50 phr. El aumento en la concentración de fibra afecta negativamente las propiedades de tensión, con excepción del Módulo de Elasticidad y la Resistencia a la Fluencia. La causa principal es originada por la baja adhesión interfacial fibra natural-matriz polimérica, claramente evidenciada en las imágenes SEM.

  10. Morteros Reforzados con Fibras de Bambú

    Directory of Open Access Journals (Sweden)

    Arbeláez Arce Anacilia

    1997-12-01

    Full Text Available El término fibras de bambú, hace referencia al material de desecho (aserrín, seleccionado por diferencia de peso, en inmersión en agua. Se atiene a la definición de fibras que presentan la Norma ASTM C-JI16-89 "Standard Specification for Fiber-Reinforced Concrete ". Se estudian las propiedades físico-mecánicas del mortero 1.3, reforzado con 15, 50 y 100 kg de fibras de bambú, por metro cúbico de mortero, con el objeto de determinar la factibilidad de uso de este material, como matriz para muros estructurales. En el caso de matrices de mortero reforzados para paneles, además de determinar el porcentaje de refuerzo, que permita mantener la resistencia mecánica dentro de los límites establecidos,éste debe lograr un control en el agrietamiento. De hecho en condiciones normales bajo carga, el agrietamiento es inevitable, sea cual fuere la cantidad y calidad de refuerzo usado: Sinembargo, las fibras tienen la propiedad de controlar la propagación del agrietamiento ypor ende transformaruna matrizfrágil, en un material con cierto grado de ductilidad. Los compuestos son probados a compresión axial, flexión e impacto. Las propiedades físicas de absorción de humedad ycontracciones por secado se miden en probetas con dosificación deporcentaje de refuerzo seleccionado de las pruebas mecánicas.

  11. Neuromyelitis Optica Lesion Mimicking Brainstem Glioma

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2007-12-01

    Full Text Available A 12-year-old girl who presented with weakness of the left extremities and right sided sixth cranial nerve palsy had neuromyelitis optica (NMO mistaken for brainstem glioma on MRI, in a report from Brain Research Institute, Yonsei University College of Medicine,Seoul, Republic of KoreaNeuromyelitis Optica, Optic-Spinal Syndrome, Spectroscopy.

  12. Neuromyelitis optica: a diffusional kurtosis imaging study.

    Science.gov (United States)

    Doring, T M; Lopes, F C R; Kubo, T T A; Tukamoto, G; Kimura, M C; Strecker, R M; Domingues, R C; Gasparetto, E L

    2014-12-01

    Conventional MR imaging typically yields normal images of the brain or indicates lesions in areas of high aquaporin expression in patients with neuromyelitis optica. Diffusional kurtosis imaging was applied in patients with neuromyelitis optica to determine whether this technique could detect alterations in diffusion and diffusional kurtosis parameters in normal-appearing white matter and to explore the relationship between diffusional kurtosis imaging and DTI parameters. Thirteen patients with neuromyelitis optica and 13 healthy controls underwent MR imaging of the brain with conventional and diffusional kurtosis imaging sequences. Tract-based spatial statistics and region-of-interest-based analyses were conducted to identify differences between patients with neuromyelitis optica and controls through conventional DTI and diffusional kurtosis imaging parameters. The parameters were correlated to determine the potential relationship between them. Compared with healthy controls, several diffusional kurtosis imaging and DTI parameters were altered in various fiber tracts of patients with neuromyelitis optica (P optica. We found a negative correlation between diffusional kurtosis imaging (radial kurtosis, axial kurtosis, mean kurtosis) and the corresponding DTI parameters (radial diffusivity, axial diffusivity, mean diffusivity). Positive correlations were found for radial kurtosis and mean kurtosis with fractional anisotropy. This study demonstrated differences in conventional diffusion and diffusional kurtosis parameters, especially radial kurtosis, in the normal-appearing white matter of patients with neuromyelitis optica compared with healthy controls. Larger studies of patients with neuromyelitis optica should be performed to assess the potential clinical impact of these findings. © 2014 by American Journal of Neuroradiology.

  13. Neuromyelitis optica in a young child with positive serum autoantibody

    OpenAIRE

    Loma, Ingrid P.; Asato, Miya R.; Filipink, Robyn A.; Alper, Gulay

    2008-01-01

    Relapsing neuromyelitis optica is rare in children. The identification of highly specific serum autoantibody marker (neuromyelitis optica –immunoglobulin G) differentiates neuromyelitis optica from other demyelinating disorders particularly in clinically challenging cases. We present a child with multiple episodes of transverse myelitis and optic neuritis with positive neuromyelitis optica-immunoglobulin G titers consistent with a diagnosis of relapsing neuromyelitis optica. Serial titers of ...

  14. Despliegue red fibra óptica hasta el hogar (FTTH)

    OpenAIRE

    Velasco de Miguel, Javier

    2017-01-01

    En este PFC se pretende dar una visión general de lo que es un despliegue FTTH presentando un caso teórico práctico. Está compuesto en 4 partes. En la primera parte se presenta una explicación de la evolución de las redes fijas de banda ancha llegando al uso actual de la fibra como medio de transmisión. Después, se desarrolla una parte teórica del funcionamiento y elementos presentes en las redes de comunicación ópticas. Explicaremos las partes en las que se divide la red FTTH, y se pre...

  15. Multisystem involvement in neuromyelitis optica

    Directory of Open Access Journals (Sweden)

    Megan M Langille

    2015-01-01

    Full Text Available We describe a case of pediatric neuromyelitis optica (NMO with muscle and lung involvement in addition to central nervous system disease. Our patient initially presented with features of area postrema syndrome, then subsequently with optic neuritis. The patient also had recurrent hyperCKemia that responded to corticosteroids. Finally, axillary and hilar adenopathy with pulmonary consolidation were noted as well and responded to immunomodulation. Our case highlights multisystem involvement in NMO including non-infectious pulmonary findings which have not been described in the pediatric population previously.

  16. Imaging the Visual Pathway in Neuromyelitis Optica

    Directory of Open Access Journals (Sweden)

    Caspar F. Pfueller

    2011-01-01

    Full Text Available The focus of this paper is to summarize the current knowledge on visual pathway damage in neuromyelitis optica (NMO assessed by magnetic resonance imaging (MRI and optical coherence tomography (OCT.

  17. Immunology of neuromyelitis optica during pregnancy.

    OpenAIRE

    Bove, Riley; Davoudi, V; Keyhanian, K; Bove, RM; Chitnis, T

    2016-01-01

    Anti-aquaporin-4 (AQP4) autoantibody plays a key role in the pathogenesis of neuromyelitis optica (NMO). Studies have shown increased relapse rates in patients with NMO during pregnancy and postpartum. High estrogen levels during pregnancy can increase act

  18. Cognitive impairment in Chinese neuromyelitis optica

    NARCIS (Netherlands)

    Zhang, N.; Li, Y.J.; Fu, Y.; Shao, J.H.; Luo, L.L.; Yang, L.; Shi, F.D.; Liu, Y.

    2015-01-01

    Background: Cognitive dysfunction is frequently seen in neuromyelitis optica (NMO). However, the features and influencing factors of cognitive impairment of Chinese NMO patients are unclear. Objective: To investigate the patterns of cognitive impairment in Chinese NMO patients, and correlate the

  19. Imaging the Visual Pathway in Neuromyelitis Optica

    OpenAIRE

    Pfueller, Caspar F.; Paul, Friedemann

    2011-01-01

    The focus of this paper is to summarize the current knowledge on visual pathway damage in neuromyelitis optica (NMO) assessed by magnetic resonance imaging (MRI) and optical coherence tomography (OCT).

  20. The Treatment of Neuromyelitis Optica

    Science.gov (United States)

    Kowarik, Markus C.; Soltys, John; Bennett, Jeffrey L.

    2014-01-01

    Neuromyelitis optica (NMO) is an autoimmune disorder of the central nervous system directed against astrocytes. Initially diagnosed in individuals with monophasic or relapsing optic neuritis and transverse myelitis, NMO is now recognized as a demyelinating disorder with pleiotropic presentations due to the identification of a specific autoantibody response against the astrocyte water channel aquaporin-4 in the majority of individuals. As visual impairment and neurologic dysfunction in NMO are commonly severe, aggressive treatment of relapses and prophylactic immunomodulatory therapy are the focus of treatment. Although there are no approved treatments for NMO, medications and therapeutic interventions for acute and chronic treatment have been the subject of retrospective study and case reports. The goal of this review is to familiarize the reader with biologic and clinical data supporting current treatments in NMO and highlight future strategies based on advancements in our understanding of NMO pathogenesis. PMID:24531318

  1. The history of neuromyelitis optica

    Science.gov (United States)

    2013-01-01

    The discovery of a novel serum autoantibody (termed NMO-IgG or AQP4-Ab) in a subset of patients in 2004 has revived interest in neuromyelitis optica (NMO). While the history of classical multiple sclerosis has been extensively studied, only little is known about the history of NMO. In the present article, we provide a comprehensive review of the early history of this rare but intriguing syndrome. We trace the origins of the concept of NMO in the 19th century medical literature and follow its evolution throughout the 20th and into the 21st century. Finally, we discuss recent proposals to revise the concept of NMO and explain why there is indeed a need for a more systematic and descriptive nomenclature. PMID:23320783

  2. Disminución de las propiedades mecánicas de compuestos de matriz termoplástica tras dilatada permanencia en agua oxigenada

    Directory of Open Access Journals (Sweden)

    Viña, J.

    2001-04-01

    Full Text Available The evolution of the mechanical properties, static and dynamic, of two different composites with thermoplastic matrix and glass-fiber fabric or carbon-fiber fabric as reinforcement after immersing in a hydrogen peroxide solution have been analyzed. The tensile strength suffered a decrease after exposure of the materials in the solution. This decrease was more important in the case of the glass-fiber composite than in carbon-fiber composite. On the other hand, the interlaminar shear strength suffered also an important decrease, but in this case more substantial for the carbon-fiber composite. Finally, the fatigue behavior of the materials have been studied after exposure to the hydrogen peroxide solution. The results correlate with the tensile results.

    Se ha analizado la evolución de las propiedades mecánicas, tanto estáticas como dinámicas, de dos composites de matriz termoplástica reforzados con tejido de fibra de vidrio y fibra de carbono, tras mantener inmersas probetas de ambos materiales en una solución de agua oxigenada, empleada en el método TCF, útil en la fabricación de papel. Se observa, desde el punto de vista de la resistencia a tracción, una pérdida de propiedades mucho mayor en el caso del compuesto con fibra de vidrio que en el de fibra de carbono. En cambio, en las curvas correspondientes a la variación de la resistencia a cortadura interlaminar, se aprecia una pérdida muy importante, pero superior para el compuesto de fibra de carbono. Por último, también se mostrará el comportamiento de ambos compuestos a fatiga tras permanencia en la solución de agua oxigenada. Los resultados obtenidos muestran una gran correlación con los generados a partir de los ensayos de tracción.

  3. Infinitivo simple y compuesto con predicados declarativos

    OpenAIRE

    Rodríguez Espiñeira, María José

    2012-01-01

    Este trabajo se centra en las diferencias semánticas y sintácticas que presentan las construcciones de infinitivo simple y compuesto que actúan como objeto directo de predicados declarativos. El tema despierta interés por varios motivos: (1) Se trata de un subconjunto de verbos que subordinan infinitivos simples de un elenco restringido, pero que admiten regularmente infinitivos compuestos.

  4. Procesado, estructura y propiedades de materiales compuestos de matriz termoplástica y nanorefuerzos de carbono

    OpenAIRE

    Ramón Valencia, Bladimir Azdrúbal

    2014-01-01

    208 p. El presente trabajo de tesis doctoral está orientado hacia el conocimiento de la relación existente entre los procesos de conformación, estructura y propiedades mecánicas y térmicas de termoplásticos de alto rendimiento mediante la incorporación de nanorefuerzos de tipos carbonoso. En el primer apartado se realizó un estudio comparativo del efecto de las fibras de carbono cortas (FC) y de las nanofibras de carbono (CNF) en los materiales compuestos de matriz de PEEK con el objeto de...

  5. Neuromyelitis Optica: A Case Report

    Directory of Open Access Journals (Sweden)

    Wei-Chia Chia

    2010-12-01

    Full Text Available Neuromyelitis optica (NMO, Devic's syndrome is a demyelinating disease of the central nervous system that predominantly affects the spinal cord and optic nerves. It is often confused with multiple sclerosis. Early discrimination between NMO and multiple sclerosis is important because the two diseases have different natural histories and treatment regimens. Seropositivity for NMO-IgG and longitudinally extensive spinal cord lesions (3 or more spinal segments are characteristic of NMO. Despite the absence of a definitive therapeutic strategy for NMO syndrome, methylprednisolone pulse therapy is recommended in the acute phase. Treatment strategies in relapse phases are aimed at preventing relapses, and increasing evidence shows a better clinical response of immunosuppressive therapy than immuno-modulating therapy (a standard multiple sclerosis-modulating therapy. We describe a 10-year-old girl who had visual loss due to acute optic neuritis at 6 years old and suffered repetitive myelitis 2 years later. NMO was diagnosed because of characteristic longitudinal myelitis and positive NMO-IgG. After combining therapy with prednisolone and an immunosuppressant (cyclophosphamide, the patient's medical condition was stable and no relapse symptoms were observed.

  6. OPTIC NEURITIS IN NEUROMYELITIS OPTICA

    Science.gov (United States)

    Levin, Marc H.; Bennett, Jeffrey L.; Verkman, A.S.

    2013-01-01

    Neuromyelitis optica (NMO) is an autoimmune demyelinating disease associated with recurrent episodes of optic neuritis and transverse myelitis, often resulting in permanent blindness and/or paralysis. The discovery of autoantibodies (AQP4-IgG) that target aquaporin-4 (AQP4) has accelerated our understanding of the cellular mechanisms driving NMO pathogenesis. AQP4 is a bidirectional water channel expressed on the plasma membranes of astrocytes, retinal Müller cells, skeletal muscle, and some epithelial cells in kidney, lung and the gastrointestinal tract. AQP4 tetramers form regular supramolecular assemblies at the cell plasma membrane called orthogonal arrays of particles. The pathological features of NMO include perivascular deposition of immunoglobulin and activated complement, loss of astrocytic AQP4, inflammatory infiltration with granulocyte and macrophage accumulation, and demyelination with axon loss. Current evidence supports a causative role of AQP4-IgG in NMO, in which binding of AQP4-IgG to AQP4 orthogonal arrays on astrocytes initiates complement-dependent and antibody-dependent cell-mediated cytotoxicity and inflammation. Immunosuppression and plasma exchange are the mainstays of therapy for NMO optic neuritis. Novel therapeutics targeting specific steps in NMO pathogenesis are entering the development pipeline, including blockers of AQP4-IgG binding to AQP4 and inhibitors of granulocyte function. However, much work remains in understanding the unique susceptibility of the optic nerves in NMO, in developing animal models of NMO optic neuritis, and in improving therapies to preserve vision. PMID:23545439

  7. Molecular Pathogenesis of Neuromyelitis Optica

    Science.gov (United States)

    Bukhari, Wajih; Barnett, Michael H; Prain, Kerri; Broadley, Simon A

    2012-01-01

    Neuromyelitis optica (NMO) is a rare autoimmune disorder, distinct from multiple sclerosis, causing inflammatory lesions in the optic nerves and spinal cord. An autoantibody (NMO IgG) against aquaporin-4 (AQP4), a water channel expressed on astrocytes is thought to be causative. Peripheral production of the antibody is triggered by an unknown process in genetically susceptible individuals. Anti-AQP4 antibody enters the central nervous system (CNS) when the blood brain barrier is made permeable and has high affinity for orthogonal array particles of AQP4. Like other autoimmune diseases, Th17 cells and their effector cytokines (such as interleukin 6) have been implicated in pathogenesis. AQP4 expressing peripheral organs are not affected by NMO IgG, but the antibody causes extensive astrocytic loss in specific regions of the CNS through complement mediated cytotoxicity. Demyelination occurs during the inflammatory process and is probably secondary to oligodendrocyte apoptosis subsequent to loss of trophic support from astrocytes. Ultimately, extensive axonal injury leads to severe disability. Despite rapid advances in the understanding of NMO pathogenesis, unanswered questions remain, particularly with regards to disease mechanisms in NMO IgG seronegative cases. Increasing knowledge of the molecular pathology is leading to improved treatment strategies. PMID:23202933

  8. Fiber into the loop transmission. Transmision por fibra optica hacia el abonado

    Energy Technology Data Exchange (ETDEWEB)

    Martin Minguez, A.

    1993-03-15

    In this paper some considerations are presented about Fiber into the Loop (FITL) transmission. A preliminary comparison between copper and optical cables is made and the conclusion is the convenience to introduce optical fiber in the subcriber loop for narrow-band and broadband services transmission. Some comments are made about the structure of the optical plant regarding topology: passive, active, point to point, point to multipoint, etc., and also, about the use of the optical windows (2nd and 3nd) in the fiber. Procedures for the optical maintenance of the network are outlined due to their great importance to the PTTs. Transmission methods and their application in the PON (Passive Optical Networks) for point to multipoint transmission (TDM, TDMA) are considered. (Author)

  9. Acumulación de daño y redistribución de los esfuerzos en materiales reforzados con fibras

    Directory of Open Access Journals (Sweden)

    Anatoli S. Ovchinsky

    2013-01-01

    Full Text Available Se analiza el proceso de fractura de materiales compuestos, considerando la interacción de diferentes factores que tienen un carácter muy particular. La resistencia a la ruptura de las fibras, la resistencia localizada de la matriz y la fuerza de adherencia entre la fibra y la matriz, por lo general varían de manera substancial y, además, la distribución del reforzamiento es errática y casual. Analíticamente la interacción entre estos imprevisibles factores durante la fractura del compuesto no pueden ser plenamente descritos mediante el uso de métodos probabilísticos. El desarrollo de métodos computacionales abre enormes posibilidades para simular la influencia de estos factores durante el proceso de fractura del compuesto. Determinadas dificultades surgen en el desarrollo de estas investigaciones porque éstas sintetizan problemas de física de materiales, así como de mecánica al tener que considerar y analizar simultáneamente la estructura real del material. Por lo anterior, resulta conveniente junto con la simulación numérica aplicada al estudio de determinados fenómenos y a la solución de problemas prácticos, hacer uso de criterios que son fundamentales para simular los procesos de delaminación de las fibras fracturadas y el desarrollo de grietas en la matriz

  10. MATERIALES COMPUESTOS DE MATRIZ POLIMÉRICA USADOS PARA EL BLINDAJE DE INTERFERENCIA ELECTROMAGNÉTICA

    Directory of Open Access Journals (Sweden)

    Andrés Orlando Garzón Posada

    2017-01-01

    Full Text Available Este trabajo tiene como propósito revisar el estado del arte en la síntesis y caracterización de materiales de matriz polimérica reforzados con compuestos a base de carbón o ferritas para su uso como materiales atenuadores de interferencia electromagnética (EMI. Recientemente, este tipo de materiales han sido objeto de investigación debido a sus potenciales aplicaciones tecnológicas, economía y de ser además ambientalmente amigables, puesto que polímeros o cauchos reciclados se pueden utilizar para su fabricación. Estos compuestos pueden ser empleados en la producción de blindajes electromagnéticos, transductores, entrega focalizada de medicamentos, marcación de órganos, hipertermia magnética, etc. Para la fabricación de este tipo de materiales compuestos se usan refuerzos particulados, fibras o láminas y como matrices polímeros termoplásticos o termoestables, cauchos sintéticos o naturales. El método de producción de los compuestos (mezcla fundida, métodos químicos, etc. influye en las propiedades eléctricas, magnéticas y electromagnéticas del material obtenido, debido a la relación de aspecto de los refuerzos: compuestos con elevada relación de aspecto de sus refuerzos tendrán mejores propiedades magnéticas, eléctricas y desempeño frente a la interferencia electromagnética. El blindaje electromagnético de estos materiales se cuantifica a través de la efectividad del blindaje (SE o en otros casos a través de la pérdida reflectiva (RL. Una efectividad de blindaje de 30 dB corresponde a 99,9% de atenuación de la radiación electromagnética incidente. En todos los trabajos se comprueba que las propiedades del compuesto dependen de la cantidad y del tipo de refuerzo adicionado a la matriz.

  11. Diagnostik og behandling af neuromyelitis optica

    DEFF Research Database (Denmark)

    Nielsen, Helle Hvilsted; Ravnborg, Mads; Illes, Zsolt

    2014-01-01

    Neuromyelitis optica (NMO) is an inflammatory demyelinating disease characterized by antibodies against aquaporin-4 in up to 80% of the cases and even less in the NMO spectrum disorders, which may be difficult to distinguish from early multiple sclerosis. While immunosuppressive therapy should...

  12. Interferon alpha association with neuromyelitis optica

    DEFF Research Database (Denmark)

    Asgari, Nasrin; Voss, Anne; Steenstrup, Troels

    2013-01-01

    Interferon-alpha (IFN- α ) has immunoregulatory functions in autoimmune inflammatory diseases. The goal of this study was to determine occurrence and clinical consequences of IFN- α in neuromyelitis optica (NMO) patients. Thirty-six NMO and 41 multiple sclerosis (MS) patients from a population...

  13. Olfactory dysfunction in neuromyelitis optica spectrum disorders

    NARCIS (Netherlands)

    Zhang, L.J.; Zhao, N.; Fu, Y.; Zhang, D.Q.; Wang, J.; Qin, W.; Zhang, N.N.N.; Wood, K.; Liu, Y.; Yu, C.S.; Shi, F.D.; Yang, L.

    2015-01-01

    Few data were available for the understanding of olfactory function in neuromyelitis optica spectrum disorders (NMOSDs). The aims of our study were to investigate the incidence of olfactory dysfunction and characterize olfactory structures, using MRI, in patients with NMOSDs. Olfactory function was

  14. Relapse of Neuromyelitis Optica Spectrum Disorder Associated with Intravenous Lidocaine

    Directory of Open Access Journals (Sweden)

    Akiyuki Uzawa

    2011-01-01

    Full Text Available Lidocaine unmasks silent symptoms and eases neuropathic pain in multiple sclerosis patients; however, the effects of lidocaine in neuromyelitis optica have never been reported. We describe the case of a 59-year-old Japanese woman with neuromyelitis optica spectrum disorder who developed optic neuritis 1 day after intravenous lidocaine injection for treating allodynia. Her symptom seemed to result from a relapse of neuromyelitis optica induced by lidocaine administration, and not because of the transient effects of intravenous lidocaine administration. The possibility that lidocaine administration results in relapse of neuromyelitis optica due to its immunomodulating effects cannot be ruled out.

  15. Seronegative neuromyelitis optica after cardiac transplantation.

    Science.gov (United States)

    Kim, Elecia; Van Vrancken, Michael; Shaji, Mohamed; Mir, Osman; Spak, Cedric W; Gupta, Manu; Shamim, Sadat A

    2016-01-01

    We report a case of a 42-year-old man who presented with progressive weakness and blindness over the course of several months and met criteria for seronegative neuromyelitis optica. This presentation was in the setting of immunosuppression following cardiac transplant. No infectious causes were found within the neuroaxis, and he ultimately died with complete blindness, quadriplegia, and respiratory failure attributed to panmyelitis and brain stem inflammation despite aggressive therapies.

  16. A population-based study of neuromyelitis optica in Caucasians

    DEFF Research Database (Denmark)

    Asgari, N; Lillevang, S T; Skejoe, H P B

    2011-01-01

    Epidemiologic studies have suggested different prevalence of neuromyelitis optica (NMO) in different ethnic groups. However, data on the incidence and prevalence of NMO in Caucasians are scarce.......Epidemiologic studies have suggested different prevalence of neuromyelitis optica (NMO) in different ethnic groups. However, data on the incidence and prevalence of NMO in Caucasians are scarce....

  17. Prolonged Remission in Neuromyelitis Optica Following Cessation of Rituximab Treatment.

    Science.gov (United States)

    Weinfurtner, Kelley; Graves, Jennifer; Ness, Jayne; Krupp, Lauren; Milazzo, Maria; Waubant, Emmanuelle

    2015-09-01

    Neuromyelitis optica is an autoimmune disease characterized by acute episodes of transverse myelitis and optic neuritis. Several small, open-label studies suggest rituximab, a monoclonal antibody against CD20, prevents relapses in neuromyelitis optica; however, there is little consensus on timing or duration of treatment. Here we report four patients with severe relapsing neuromyelitis optica who were stabilized on rituximab and, after discontinuing treatment, continued to experience prolonged remission of their disease. Remission ranged from 4.5 to 10.5 years total, including 3 to 9 years off all therapies. The patients had sustained clinical responses despite normal B-lymphocyte levels and, in at least 2 patients, continued seropositivity for aquaporin-4 antibodies. These cases suggest that rituximab may induce prolonged remission in certain neuromyelitis optica patients, and they highlight the need for further elucidation of rituximab's mechanism in neuromyelitis optica. © The Author(s) 2014.

  18. Membranous nephropathy with Neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Li, Xiangling; Wang, YanQiang

    2017-07-01

    Membranous nephropathy (MN) accompanying Neuromyelitis optica spectrum disorders (NMOSD) has rarely been described previously. We recently presented a 45-year-old Chinese male presenting with recurrent lower extremity pitting edema, or eyelid edema, proteinuria and hyperlipidemia. especially intractable hiccup and vomiting, painful tonic spasm (PTS) as the revealing symptom of a demyelinating disorder of central nervous system. The kindey biopsy specimen showed MN stage 2. Serological testing revealed antibodies AQP4, MRI head and spine revealed medulla oblongata and C1-C2 cervical vertebra lesions. Treatment with methylprednisolone, cyclophosphamide, azathioprine resulted in consistent clinical improvement. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Fractura de compuestos polipropileno-talco

    OpenAIRE

    Velasco Perero, José Ignacio

    1996-01-01

    La investigación realizada en esta tesis se ha centrado en la caracterización de la fractura de materiales compuestos por una matriz de polipropileno homopolímero isotáctico y diferentes fracciones de partículas laminares de talco. Estos materiales se emplean en la actualidad para la fabricación de piezas por inyección, especialmente en el sector de automoción. Por extrusión de doble tornillo se prepararon dos series de materiales conteniendo diferentes fracciones de talco disperso, el cual f...

  20. EFNS guidelines on diagnosis and management of neuromyelitis optica

    DEFF Research Database (Denmark)

    Sellner, J; Boggild, M; Clanet, M

    2010-01-01

    Neuromyelitis optica (NMO) or Devic's disease is a rare inflammatory and demyelinating autoimmune disorder of the central nervous system (CNS) characterized by recurrent attacks of optic neuritis (ON) and longitudinally extensive transverse myelitis (LETM), which is distinct from multiple sclerosis...

  1. EFNS guidelines on diagnosis and management of neuromyelitis optica

    NARCIS (Netherlands)

    Sellner, J.; Boggild, M.; Clanet, M.; Hintzen, R.Q.; Illes, Z.; Montalban, X.; Du Pasquier, R.A.; Polman, C.H.; Sorensen, P.S.; Hemmer, B.

    2010-01-01

    Background and purpose: Neuromyelitis optica (NMO) or Devic's disease is a rare inflammatory and demyelinating autoimmune disorder of the central nervous system (CNS) characterized by recurrent attacks of optic neuritis (ON) and longitudinally extensive transverse myelitis (LETM), which is distinct

  2. Hypertrophic pachymeningitis accompanying neuromyelitis optica spectrum disorder: A case report.

    Science.gov (United States)

    Kon, Tomoya; Nishijima, Haruo; Haga, Rie; Funamizu, Yukihisa; Ueno, Tatsuya; Arai, Akira; Suzuki, Chieko; Nunomura, Jin-ichi; Baba, Masayuki; Takahashi, Toshiyuki; Tomiyama, Masahiko

    2015-10-15

    We report a case of idiopathic cerebral hypertrophic pachymeningitis accompanying neuromyelitis optica spectrum disorder. No other identifiable cause of pachymeningitis was detected. Corticosteroid therapy was effective for both diseases. Hypertrophic pachymeningitis is closely related to autoimmune inflammatory disease of the central nervous system. This case supports the hypothesis that hypertrophic pachymeningitis can be a rare comorbidity of neuromyelitis optica spectrum disorder. Copyright © 2015. Published by Elsevier B.V.

  3. Longitudinally extensive optic neuritis in neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Pula, John H; Kattah, Jorge C; Keung, Bonnie; Wang, Huaping; Daily, Jennifer

    2014-10-15

    Neuomyelitis optica, sarcoid, and multiple sclerosis can all cause optic neuritis. Further means of distinguishing the causes of optic neuritis among these etiologies would be valuable for the clinician. This is a retrospective, cohort study from a single university based hospital and neuro-ophthalmology clinic. Blinded interpretation of orbit MRIs was performed on patients with acute optic neuritis from multiple sclerosis (n=25), sarcoid (n=5) and neuromyelitis optica spectrum disorder (n=6). A length of >40 mm anterior visual pathway enhancement distinguished neuromyelitis optica spectrum disorder from multiple sclerosis (p=0.0376). No statistically significant differences were found for presence of pain or papillitis, however there was a trend for bilateral involvement and chiasmal involvement in neuromyelitis optica spectrum disorder compared to multiple sclerosis. In acute optic neuritis, enhancing anterior visual pathway lesion length >40 mm helps differentiate neuromyelitis optica spectrum disorder from multiple sclerosis. This degree of involvement can be considered longitudinally extensive optic neuritis. Further characterization is necessary as this degree of enhancement occurs in other clinical syndromes besides neuromyelitis optica. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Neuromyelitis Optica and Neuromyelitis Optica Spectrum Disorder Patients in Turkish Cohort: Demographic, Clinical, and Laboratory Features.

    Science.gov (United States)

    Altintas, Ayse; Karabudak, Rana; Balci, Belgin P; Terzi, Murat; Soysal, Aysun; Saip, Sabahattin; Tuncer Kurne, Asli; Uygunoglu, Ugur; Nalbantoglu, Mecbure; Gozubatik Celik, Gokcen; Isik, Nihal; Celik, Yahya; Gokcay, Figen; Duman, Taskin; Boz, Cavit; Yucesan, Canan; Mangan, Mehmet Serhat; Celebisoy, Nese; Diker, Sevda; Colpak Isikay, Ilksen; Kansu, Tulay; Siva, Aksel

    2015-10-01

    Neuromyelitis optica (NMO) is an immune-mediated, chronic relapsing, inflammatory disease characterized by severe attacks of optic neuritis and myelitis. To determine the demographic, clinical, and laboratory features; antibody status; and treatment modalities of patients with NMO and neuromyelitis optica spectrum disorders in a Turkish cohort from 11 centers. A total of 182 patients were included in this study. Data on age at disease onset, sex, type of attacks, clinical presentation, analysis of cerebrospinal fluid, serum antiaquaporin-4 antibody status, annual progression index, and medical and family histories were collected. Mean age was 38.43±12.40 years (range, 13 to 75 y), and mean age at disease onset was 31.29±12.40 years (median, 29 y; range, 10 to 74 y). In NMO group, the rate of NMO immunoglobulin (Ig)G positivity was 62.5%. The annual progression index was significantly higher in the longitudinally extending spinal cord lesion. The mean Expanded Disability Status Scale score was higher in the late than early-onset NMO group. Our results revealed a lower rate of NMO IgG positivity, more severe disability in patients with NMO/neuromyelitis optica spectrum disorders presenting with either transverse myelitis or late-onset NMO, and no correlation between disability and NMO IgG status.

  5. Influencia de las fibras de carbono y fibras de vidrio en materiales compuestos como modelo en la implementación de pisos industriales

    Directory of Open Access Journals (Sweden)

    Willian Aperador

    2010-07-01

    Full Text Available Designed and manufactured material composed of fiberglass and carbon fiber as a reinforcing agent in a polyester resin as matrix. In this study we evaluated the effect provided by each of the agents mentioned above, within the matrix in improving the mechanical properties of fiber-reinforced material. The mechanical characterization was performed by bending tests. To this was gradually increased the load on the tile to be tested until rupture, resulting in a rate greater effort on the tile that has been reinforced with fibers. The study concludes that the reinforcing agent (fiberglass and carbon fiber within the tile, has significant effects on the matrix of the composite, because these tiles support higher stresses induced.

  6. Neuromyelitis Optica (Devic's Syndrome): an Appraisal.

    Science.gov (United States)

    Crout, Teresa M; Parks, Laura P; Majithia, Vikas

    2016-08-01

    Neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorders (NMOSD), previously known as Devic's syndrome, are a group of inflammatory disorders of the central nervous system (CNS) characterized by severe, immune-mediated demyelination and axonal damage, predominantly targeting optic nerves and the spinal cord typically associated with a disease-specific serum NMO-IgG antibody that selectively binds aquaporin-4 (AQP4). The classic and best-defined features of NMOSD include acute attacks of bilateral or rapidly sequential optic neuritis (leading to visual loss) or transverse myelitis (often causing limb weakness and bladder dysfunction) or both with a typically relapsing course. The diagnosis of NMO/NMOSD requires a consistent history and examination with typical clinical presentations, findings on spinal cord neuroimaging with MRI, cerebrospinal fluid analysis along with determination of AQP4-IgG serum autoantibody status, and exclusion of other disorders. Two major advances in this field has been the development of diagnostic criteria and treatment recommendations. Consensus diagnostic criteria have been established and were recently revised and published in 2015, enhancing the ability to make a diagnosis and appropriately evaluate these disorders. Expert recommendations and uncontrolled trials form the basis of treatment guidelines. All patients with suspected NMOSD should be treated for acute attacks as soon as possible with high-dose intravenous methylprednisolone -1 gram daily for three to five consecutive days and in some cases, plasma exchange should be used. It is recommended that every patient with NMOSD be started on an immunosuppressive agent, such as, azathioprine, methotrexate, or mycophenolate and in some cases, rituximab, soon after the acute attack and usually be treated for about 5 years after the attack. These advances have helped improve the prognosis and outcome in these disorders.

  7. Volatile Compounds in Honey Produced in the Central Valley of Ñuble Province, Chile Compuestos Volatiles en Miel Producida en el Valle Central de la Provincia de Ñuble, Chile

    Directory of Open Access Journals (Sweden)

    María Pía Gianelli Barra

    2010-03-01

    Full Text Available Headspace solid-phase microextraction (SPME with an 85 µm Carboxen polydimethylsiloxane (CAR/PDMS fiber was used to extract volatile compounds, and a gas chromatograph equipped with a mass spectometry detector (GC-MS was used to identify the volatile compounds in honeys. Thirty-four different volatile compounds from the headspace of honey produced in the central valley of Ñuble Province, Chile, were extracted with fiber coating CAR/PDMS. The identified compounds were: 10 alcohols, 9 acids, 6 ketones, 3 aldehydes, 2 furans, 2 terpenes and 2 lactones. Only four of the volatile compounds had never been reported before as honey compounds; these being: 1,3-propanodiol, 2-methyl butanoic acid, 3,4-dimethyl-3-hexen-2-one, and 6-methyl-5-octen-2-one. These four compounds were found in three of the 10 analyzed samples. The compounds found in the highest percentage of area were ethanol, acetic acid, 1-hydroxy-2-propane, 3-hydroxy-2-butane, and furfural. However, the analyzed samples did not present a distinctive profile.La extracción de compuestos volátiles desde el espacio de cabeza de mieles se realiza mediante microextracción en fase sólida (SPME, utilizando una fibra de 85 µm de Carboxen polidimetilsiloxano (CAR/PDMS, el análisis de los compuestos volátiles se realiza mediante cromatografía de gases con detector de masa (GC-MS. Un total de 34 diferentes compuestos volátiles fueron extraídos desde el espacio de cabeza de mieles provenientes del valle central de la provincia de Ñuble con la fibra de CAR/PDMS. Los compuestos identificados fueron 10 alcoholes, 9 ácidos, 6 cetonas, 3 aldehídos, 2 furanos, 2 terpenos y 2 lactonas. De los compuestos volátiles sólo tres no han sido reportados con anterioridad en mieles, estos compuestos fueron: 1,3-propanodiol, ácido 2-metil butanoico, 3,4-dimetil-3-hexen-2-ona, 6-metil-5-octen-2-ona. Estos cuatro compuestos se encontraron en sólo tres de las 10 muestras analizadas. Los compuestos que se

  8. Actividad antioxidante de compuestos naturales nitrogenados

    Directory of Open Access Journals (Sweden)

    Maestro-Durán, R.

    1993-06-01

    Full Text Available As a continuation of the study of natural antioxidants, this third part deals with nitrogeneous compounds, classified in the following groups.

    Amino acids and proteins.
    Products of the Maillard reaction.
    Phospholipids (with choline or ethanolamine and their heating products.
    Riboflavin.
    Chlorophylls and porphyrins.
    Uric acid and derivatives.
    Their behaviour as inhibitors of the chain reaction of prooxidant radicals, by irreversible reaction or by sequestration of those radicals, as well as their synergistic action with primary antioxidants is discussed. Finally, the patents registered during the last years for these kind of compounds, their derivatives and synergists in food and other uses are cited.

    Continuando el estudio de los antioxidantes naturales, se incluyen en esta tercera parte los compuestos nitrogenados, clasificados en los siguientes grupos:
    Aminoácidos y proteínas.
    Productos de la reacción coloreada de Maillard.
    Fosfolípidos (con las bases colina y etanolamina y sus productos de calentamiento.
    Riboflavina.
    Clorofilas y porfirinas.
    Acido úrico y sus derivados.
    Se discute su comportamiento como inhibidores de la reacción en cadena de los radicales prooxidantes, por reacción irreversible o por secuestro de estos radicales, así como su acción sinergista con antioxidantes primarios. Finalmente, se citan las patentes registradas en los últimos años para estos tipos de compuestos, sus derivados y sinergistas, en productos alimentarios o en otros usos.

  9. Neuromyelitis optica-like pathology is dependent on type I interferon response.

    Science.gov (United States)

    Khorooshi, Reza; Wlodarczyk, Agnieszka; Asgari, Nasrin; Owens, Trevor

    2013-09-01

    Neuromyelitis optica is an antibody-mediated autoimmune inflammatory disease of the central nervous system. Reports have suggested that interferon beta which is beneficial for multiple sclerosis, exacerbates neuromyelitis optica. Our aim was to determine whether type I interferon plays a role in the formation of neuromyelitis optica lesions. Immunoglobulin G from a neuromyelitis optica patient was injected intracerebrally with human complement to type I interferon receptor deficient and wildtype mice. Loss of aquaporin-4 and glial fibrillary acidic protein was reduced in type I interferon receptor deficient mice brain. Our findings suggest that type I interferon signaling contributes to neuromyelitis optica pathogenesis. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Neuromyelitis optica with onset in childhood and adolescence.

    Science.gov (United States)

    Fragoso, Yara Dadalti; Ferreira, Maria L B; Oliveira, Enedina M L; Domingues, Renan B; Ribeiro, Taysa A G J; Brooks, Joseph B B; Claudino, Rinaldo; Netto, Jussara M K; Gomes, Sidney; Adoni, Tarso; Carneiro, Denise S D; Fonseca, Daiana R P; Fragomeni, Manuela O; Oliveira, Francisco T M; Oliveira, Celso L S; Saldanha, Patricia C O; Souza, Jorge M B

    2014-01-01

    Neuromyelitis optica with onset before the age of 18 years is a relatively rare, yet potentially devastating condition. The objective of the present study was to contribute to the study of early-onset neuromyelitis optica with a case series. Data were collected from medical records of Brazilian neurologists caring for patients with neuromyelitis optica occurring in childhood and adolescence. Twenty-nine patients with neuromyelitis optica occurring before the age of 18 years and fulfilling the diagnostic criteria were identified. The average age at disease onset was 13 years and the patients had had an average disease duration of 6 years. The expanded disability scale score at the latest consultation was, on average, 4.7, and one patient had died from the disease. The 29 patients had had an average 4.5 relapses during the disease, accounting for 0.75 relapses per year, irrespective of the medication used. All patients were using one or more of the following medications: azathioprine, prednisone, immunoglobulin, and glatiramer acetate. Neuromyelitis optica with onset in childhood and adolescence is a poorly understood condition that is often disabling and difficult to manage. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Detection of anti-aquaporin-4 autoantibodies in the sera of Chinese neuromyelitis optica patients

    Institute of Scientific and Technical Information of China (English)

    Miao Li; Weiheng Su; Jie Wang; Francesco Pisani; Antonio Frigeri; Tonghui Ma

    2013-01-01

    In this study, we recruited 10 neuromyelitis optica patients, two multiple sclerosis patients and two myelitis patients. Chinese hamster lung fibroblast (V79) cells transfected with a human aquaporin-4-mCherry fusion protein gene were used to detect anti-aquaporin-4 antibody in neuromyelitis optica patient sera by immunofluorescence. Anti-aquaporin-4 autoantibody was stably detected by immunofluorescence in neuromyelitis optica patient sera exclusively. The sensitivity of the assay for neuromyelitis optica was 90% and the specificity for neuromyelitis optica was 100%. The anti-aquaporin-4 antibody titers in sera were tested with serial dilutions until the signal disappeared. A positive correlation was detected between Expanded Disability Status Scale scores and serum anti-aquaporin-4 antibody titers. The anti-aquaporin-4 antibody assay is highly sensitive and specific in the sera of Chinese neuromyelitis optica patients. Detection of aquaporin-4 autoantibody is important for the diagnosis and treatment of neuromyelitis optica.

  12. Detection of anti-aquaporin-4 autoantibodies in the sera of Chinese neuromyelitis optica patients.

    Science.gov (United States)

    Li, Miao; Su, Weiheng; Wang, Jie; Pisani, Francesco; Frigeri, Antonio; Ma, Tonghui

    2013-03-15

    In this study, we recruited 10 neuromyelitis optica patients, two multiple sclerosis patients and two myelitis patients. Chinese hamster lung fibroblast (V79) cells transfected with a human aquaporin-4-mCherry fusion protein gene were used to detect anti-aquaporin-4 antibody in neuromyelitis optica patient sera by immunofluorescence. Anti-aquaporin-4 autoantibody was stably detected by immunofluorescence in neuromyelitis optica patient sera exclusively. The sensitivity of the assay for neuromyelitis optica was 90% and the specificity for neuromyelitis optica was 100%. The anti-aquaporin-4 antibody titers in sera were tested with serial dilutions until the signal disappeared. A positive correlation was detected between Expanded Disability Status Scale scores and serum anti-aquaporin-4 antibody titers. The anti-aquaporin-4 antibody assay is highly sensitive and specific in the sera of Chinese neuromyelitis optica patients. Detection of aquaporin-4 autoantibody is important for the diagnosis and treatment of neuromyelitis optica.

  13. Detection of anti-aquaporin-4 autoantibodies in the sera of Chinese neuromyelitis optica patients★

    Science.gov (United States)

    Li, Miao; Su, Weiheng; Wang, Jie; Pisani, Francesco; Frigeri, Antonio; Ma, Tonghui

    2013-01-01

    In this study, we recruited 10 neuromyelitis optica patients, two multiple sclerosis patients and two myelitis patients. Chinese hamster lung fibroblast (V79) cells transfected with a human aquaporin-4-mCherry fusion protein gene were used to detect anti-aquaporin-4 antibody in neuromyelitis optica patient sera by immunofluorescence. Anti-aquaporin-4 autoantibody was stably detected by immunofluorescence in neuromyelitis optica patient sera exclusively. The sensitivity of the assay for neuromyelitis optica was 90% and the specificity for neuromyelitis optica was 100%. The anti-aquaporin-4 antibody titers in sera were tested with serial dilutions until the signal disappeared. A positive correlation was detected between Expanded Disability Status Scale scores and serum anti-aquaporin-4 antibody titers. The anti-aquaporin-4 antibody assay is highly sensitive and specific in the sera of Chinese neuromyelitis optica patients. Detection of aquaporin-4 autoantibody is important for the diagnosis and treatment of neuromyelitis optica. PMID:25206717

  14. Modelado de Materiales Compuestos por Elementos Finitos usando Restricciones Cinemáticas Finite Element Modeling of Composite Materials using Kinematic Constraints

    Directory of Open Access Journals (Sweden)

    Oscar E. Ruiz

    2009-12-01

    Full Text Available El propósito de este artículo es presentar simulaciones del comportamiento de materiales compuestos basado en restricciones cinemáticas entre las mismas fibras y entre las fibras y la resina circundante. En la revisión de literatura, los autores han encontrado que las restricciones cinemáticas no han sido plenamente explotadas para modelar materiales compuestos, probablemente debido a su alto costo computacional. El propósito de este articulo es exponer la implementación y resultados de tal modelo, usando Análisis por Elementos Finitos de restricciones geométricas prescritas a los nodos de la resina y las fibras. Las descripciones analíticas del comportamiento de materiales compuestos raramente aparecen. Muchas aproximaciones para describir materiales compuestos en capas son basadas en la teoría de funciones C1Z y C0 Z, tal como la Teoría Clásica de Capas (CLT. Estas teorías de funciones contienen significativas simplificaciones del material, especialmente para compuestos tejidos. Una aproximación hibrida para modelar materiales compuestos con Elementos Finitos (FEA fue desarrollada por Sidhu y Averill y adaptada por Li y Sherwood para materiales compuestos tejidos con polipropileno de vidrio.The purpose of this article is to present simulations of the behavior of composite materials based on kinematic restrictions among the fibers themselves and among fibers and the surrounding resine. In the literature review the authors have found that the kinematic restrictions have not been fully exploited for modeling composite materials, probably due to their high computational expense. The purpose of this article is to show the implementation and results of such a model, by using a Finite Element Analysis of geometric restrictions prescribed to the resine and fiber nodes. Closed analytic descriptions on behavior of layered composite materials are very rare. Many approaches to describe layered composite material are based on the theory of

  15. Compuestos cementantes no convencionales reforzados con fibras vegetales: Una revisión de estrategias para mejorar la durabilidad

    OpenAIRE

    Santos, S. F.; Tonoli, G. H.D.; Mejia, J. E.B.; Fiorelli, J.; Savastano Jr, H.

    2015-01-01

    The present review shows the state-of-art on the approachs about improving the processing, physical- mechanical performance and durability of non-conventional fiber-cement composites. The objective of this review is to show some of these strategies to mitigate the degradation of the vegetable fibers used as reinforcement in cost-effective and non-conventional fiber-cement and, consequently, to improve their mechanical and durability properties for applications in the housing construction. Bey...

  16. Brain MRI lesions in neuromyelitis optica: clinical case

    International Nuclear Information System (INIS)

    Rosales Bravo, Luis Guillermo; Heyden Cordero, Marvin; Chinchilla Weinstok, Dennis; Mendelewicz Goldwaig, Isaias

    2011-01-01

    Many cases of patients with neuromyelitis optica have submitted without demyelinating lesions in the cerebral white matter, it has documented that this entity can cause from the onset of illness or through its natural evolution. Diagnostic methods currently as Magnetic Resonance Imaging (MRI) and specific antibodies in plasma (such as antiaquaporin-4) have been diagnosed of neuromyelitis optica cases that were initially confused with multiple sclerosis. Disease in Costa Rica has been little prevalent and is not exactly known what the prevalence and incidence. The degree of disorder is illustrated through a case study, both in the cerebral white matter as spinal cord, in a patient with neuromyelitis optica during a follow-up period of 4 years. This is the first case that has been reported in the scientific literature of Costa Rica. (author) [es

  17. Neuromyelitis optica in an adolescent after bone marrow transplantation.

    Science.gov (United States)

    Baumer, Fiona M; Kamihara, Junne; Gorman, Mark P

    2015-01-01

    Central nervous system complications of bone marrow transplant are a common occurrence and the differential diagnosis is quite broad, including opportunistic infections, medications toxicities, graft versus host disease, and other autoimmune processes. We summarize previously reported cases of autoimmune myelitis in post-transplant patients and discuss a 17-year-old boy who presented with seronegative neuromyelitis optica after a bone marrow transplant for acute myeloid leukemia. Our patient had a marked improvement in symptoms after plasmapheresis. Including our patient, there have been at least eight cases of post-transplant autoimmune myelitis presented in the literature, and at least three of these are suspicious for neuromyelitis optica. Several of these patients had poor outcomes with persistent symptoms after the myelitis. Autoimmune processes such as neuromyelitis optica should be carefully considered in patients after transplant as aggressive treatment like early plasmapheresis may improve outcomes. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Neuromyelitis optica antibody in Leber hereditary optic neuropathy: case report

    Directory of Open Access Journals (Sweden)

    Luciano Mesquita Simão

    2012-08-01

    Full Text Available Neuromyelitis optica antibody (or aquaporin-4 antibody is a well stablished serum marker associated to high-risk neuromyelitis optica syndrome that presents as an inflammatory demyelinating disease characterized by the occurrence of bilateral and simultaneous optic neuritis without complete visual recovery or it occurs as an isolated episode of transverse myelitis accompanied by longitudinally extensive spinal cord lesions. On the other hand, Leber hereditary optic neuropathy is a primarily hereditary disorder that affects all tissues of the body and its clinical presentation is tissue-specific for the optic nerve and, eventually, it might reach the spinal cord. Overlapping clinical features of neuromyelitis optica and Leber hereditary optic neuropathy may suggest common target organ diseases. The case report described herein emphasizes the coexistence of serum markers of both diseases, and suggests that further investigation of this challenging clinical presentation is warranted to confirm or rule out this association.

  19. Material compuesto nanoestructurado con propiedades gemológicas

    OpenAIRE

    Díaz, Luis A.; Torrecillas, Ramón; Moya, J. S.; Fernández, Adolfo

    2015-01-01

    La presente invención se refiere a un material compuesto nanoestructurado que comprende al menos circona y nanoparticulas de diamante y presenta una coloración dentro del sistema de colores CIE L*a*b* correspondiente a valores del índice L* comprendidos entre 40 y 98. Es asimismo objeto de la invención el procedimiento para la obtención de dicho material compuesto.

  20. Brain Abnormalities in Neuromyelitis Optica Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Woojun Kim

    2012-01-01

    Full Text Available Neuromyelitis optica (NMO is an idiopathic inflammatory syndrome of the central nervous system that is characterized by severe attacks of optic neuritis (ON and myelitis. Until recently, NMO was considered a disease without brain involvement. However, since the discovery of NMO-IgG/antiaqaporin-4 antibody, the concept of NMO was broadened to NMO spectrum disorder (NMOSD, and brain lesions are commonly recognized. Furthermore, some patients present with brain symptoms as their first manifestation and develop recurrent brain symptoms without ON or myelitis. Brain lesions with characteristic locations and configurations can be helpful in the diagnosis of NMOSD. Due to the growing recognition of brain abnormalities in NMOSD, these have been included in the NMO and NMOSD diagnostic criteria or guidelines. Recent technical developments such as diffusion tensor imaging, MR spectroscopy, and voxel-based morphometry reveal new findings related to brain abnormalities in NMOSD that were not identified using conventional MRI. This paper focuses on the incidence and characteristics of the brain lesions found in NMOSD and the symptoms that they cause. Recent studies using advanced imaging techniques are also introduced.

  1. Magnetic Resonance Imaging Features of Neuromyelitis Optica

    Energy Technology Data Exchange (ETDEWEB)

    You, Sun Kyung; Song, Chang June; Park, Woon Ju; Lee, In Ho; Son, Eun Hee [Chungnam National University College of Medicine, Chungnam National University Hospital, Daejeon (Korea, Republic of)

    2013-03-15

    To report the magnetic resonance (MR) imaging features of the spinal cord and brain in patients of neuromyelitis optica (NMO). Between January 2001 and March 2010, the MR images (spinal cord, brain, and orbit) and the clinical and serologic findings of 11 NMO patients were retrospectively reviewed. The contrast-enhancement of the spinal cord was performed (20/23). The presence and pattern of the contrast-enhancement in the spinal cord were classified into 5 types. Acute myelitis was monophasic in 8 patients (8/11, 72.7%); and optic neuritis preceded acute myelitis in most patients. Longitudinally extensive cord lesion (average, 7.3 vertebral segments) was involved. The most common type was the diffuse and subtle enhancement of the spinal cord with a multifocal nodular, linear or segmental intense enhancement (45%). Most of the brain lesions (5/11, 10 lesions) were located in the brain stem, thalamus and callososeptal interphase. Anti-Ro autoantibody was positive in 2 patients, and they showed a high relapse rate of acute myelitis. Anti-NMO IgG was positive in 4 patients (4/7, 66.7%). The imaging findings of acute myelitis in NMO may helpful in making an early diagnosis of NMO which can result in a severe damage to the spinal cord, and to make a differential diagnosis of multiple sclerosis and inflammatory diseases of the spinal cord such as toxocariasis.

  2. Differential diagnosis of neuromyelitis optica spectrum disorders

    Science.gov (United States)

    Kim, Sung-Min; Kim, Seong-Joon; Lee, Haeng Jin; Kuroda, Hiroshi; Palace, Jacqueline; Fujihara, Kazuo

    2017-01-01

    Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disorder of the central nervous system (CNS) mostly manifesting as optic neuritis and/or myelitis, which are frequently recurrent/bilateral or longitudinally extensive, respectively. As the autoantibody to aquaporin-4 (AQP4-Ab) can mediate the pathogenesis of NMOSD, testing for the AQP4-Ab in serum of patients can play a crucial role in diagnosing NMOSD. Nevertheless, the differential diagnosis of NMOSD in clinical practice is often challenging despite the phenotypical and serological characteristics of the disease because: (1) diverse diseases with autoimmune, vascular, infectious, or neoplastic etiologies can mimic these phenotypes of NMOSD; (2) patients with NMOSD may only have limited clinical manifestations, especially in their early disease stages; (3) test results for AQP4-Ab can be affected by several factors such as assay methods, serologic status, disease stages, or types of treatment; (4) some patients with NMOSD do not have AQP4-Ab; and (5) test results for the AQP4-Ab may not be readily available for the acute management of patients. Despite some similarity in their phenotypes, these NMOSD and NMOSD-mimics are distinct from each other in their pathogenesis, prognosis, and most importantly treatment. Understanding the detailed clinical, serological, radiological, and prognostic differences of these diseases will improve the proper management as well as diagnosis of patients. PMID:28670343

  3. MRI characteristics of neuromyelitis optica spectrum disorder

    Science.gov (United States)

    Paul, Friedemann; Lana-Peixoto, Marco A.; Tenembaum, Silvia; Asgari, Nasrin; Palace, Jacqueline; Klawiter, Eric C.; Sato, Douglas K.; de Seze, Jérôme; Wuerfel, Jens; Banwell, Brenda L.; Villoslada, Pablo; Saiz, Albert; Fujihara, Kazuo; Kim, Su-Hyun

    2015-01-01

    Since its initial reports in the 19th century, neuromyelitis optica (NMO) had been thought to involve only the optic nerves and spinal cord. However, the discovery of highly specific anti–aquaporin-4 antibody diagnostic biomarker for NMO enabled recognition of more diverse clinical spectrum of manifestations. Brain MRI abnormalities in patients seropositive for anti–aquaporin-4 antibody are common and some may be relatively unique by virtue of localization and configuration. Some seropositive patients present with brain involvement during their first attack and/or continue to relapse in the same location without optic nerve and spinal cord involvement. Thus, characteristics of brain abnormalities in such patients have become of increased interest. In this regard, MRI has an increasingly important role in the differential diagnosis of NMO and its spectrum disorder (NMOSD), particularly from multiple sclerosis. Differentiating these conditions is of prime importance because early initiation of effective immunosuppressive therapy is the key to preventing attack-related disability in NMOSD, whereas some disease-modifying drugs for multiple sclerosis may exacerbate the disease. Therefore, identifying the MRI features suggestive of NMOSD has diagnostic and prognostic implications. We herein review the brain, optic nerve, and spinal cord MRI findings of NMOSD. PMID:25695963

  4. Autoantibodies in patients with neuromyelitis optica

    Directory of Open Access Journals (Sweden)

    Xin FAN

    2016-10-01

    Full Text Available Neuromyelitis optica (NMO is an autoimmune disease of the central nervous system (CNS which primarily involves the optic nerve and spinal cord. Aquaporin 4 (AQP4 is the main objective antigen, and its specific antibody was NMO-IgG. It was found in clinic that most of NMO-IgG-positive patients were female, whose clinical symptoms were more severe, bilateral optic neuritis (BON or optic neuritis (ON and myelitis were more likely to appear at the same time, and involved spinal segments were longer. Recent studies discovered that anti-aquaporin 1 (AQP1 and anti-myelin oligodendrocyte glycoprotein (MOG antibodies existed in the serum of patients with NMO-IgG-negative. It was discovered that low proportions of women, more cases of long-segment spinal cord lesion, and rare cases of ON appeared in anti-AQP1 antibody-positive patients. Most of anti-MOG antibody-positive patients were male. ON was common, especially bilateral optic nerves involved at the same time, and thoracolumbar involvement was common. DOI: 10.3969/j.issn.1672-6731.2016.10.004

  5. Brain MRI abnormalities in neuromyelitis optica

    Energy Technology Data Exchange (ETDEWEB)

    Wang Fei, E-mail: feiwang1973@gmail.com [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, 45 Chang-Chun St, Xuanwu District, Beijing 100053 (China); Liu Yaou, E-mail: asiaeurope80@gmail.com [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, 45 Chang-Chun St, Xuanwu District, Beijing 100053 (China); Duan Yunyun, E-mail: duanyun2003@sohu.com [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, 45 Chang-Chun St, Xuanwu District, Beijing 100053 (China); Li Kuncheng, E-mail: kunchengli@yahoo.com.cn [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, 45 Chang-Chun St, Xuanwu District, Beijing 100053 (China); Education Ministry Key Laboratory for Neurodegenerative Disease, Xuanwu Hospital, Capital University of Medical Sciences, 45 Chang-Chun St, Xuanwu District, Beijing 100053 (China)

    2011-11-15

    Objective: The purpose of this study was to explore brain MRI findings in neuromyelitis optica (NMO) and to investigate specific brain lesions with respect to the localization of aquaporin-4 (AQP-4). Materials and methods: Forty admitted patients (36 women) who satisfied the 2006 criteria of Wingerchuk et al. for NMO were included in this study. All patients received a neurological examination and MRI scanning including brain and spinal cord. MRIs were classified as normal, nonspecific, multiple sclerosis-like, typical abnormalities. MS-like lesions were too few to satisfy the Barkhof et al. criteria for MS. Confluent lesions involving high AQP-4 regions were considered typical. Non-enhancing deep white matter lesions other than MS-like lesions or typical lesions were classified as nonspecific. Results: Brain MRI lesions were delineated in 12 patients (25%). Four patients (10%) had hypothalamus, brainstem or periventricle lesions. Six (15%) patients were nonspecific, and 2 (5%) patients had multiple sclerosis-like lesions. Conclusion: Brain MRIs are negative in most NMO, and brain lesions do not exclude the diagnosis of NMO. Hypothalamus, brainstem or periventricle lesions, corresponding to high sites of AQP-4 in the brain, are indicative of lesions of NMO.

  6. Immunopathogenesis in Myasthenia Gravis and Neuromyelitis Optica

    Science.gov (United States)

    Wang, Zhen; Yan, Yaping

    2017-01-01

    Myasthenia gravis (MG) and neuromyelitis optica (NMO) are autoimmune channelopathies of the peripheral neuromuscular junction (NMJ) and central nervous system (CNS) that are mainly mediated by humoral immunity against the acetylcholine receptor (AChR) and aquaporin-4 (AQP4), respectively. The diseases share some common features, including genetic predispositions, environmental factors, the breakdown of tolerance, the collaboration of T cells and B cells, imbalances in T helper 1 (Th1)/Th2/Th17/regulatory T cells, aberrant cytokine and antibody secretion, and complement system activation. However, some aspects of the immune mechanisms are unique. Both targets (AChR and AQP4) are expressed in the periphery and CNS, but MG mainly affects the NMJ in the periphery outside of CNS, whereas NMO preferentially involves the CNS. Inflammatory cells, including B cells and macrophages, often infiltrate the thymus but not the target—muscle in MG, whereas the infiltration of inflammatory cells, mainly polymorphonuclear leukocytes and macrophages, in NMO, is always observed in the target organ—the spinal cord. A review of the common and discrepant characteristics of these two autoimmune channelopathies may expand our understanding of the pathogenic mechanism of both disorders and assist in the development of proper treatments in the future. PMID:29312313

  7. Interferon Alpha Association with Neuromyelitis Optica

    Directory of Open Access Journals (Sweden)

    Nasrin Asgari

    2013-01-01

    Full Text Available Interferon-alpha (IFN-α has immunoregulatory functions in autoimmune inflammatory diseases. The goal of this study was to determine occurrence and clinical consequences of IFN-α in neuromyelitis optica (NMO patients. Thirty-six NMO and 41 multiple sclerosis (MS patients from a population-based retrospective case series were included. Expanded Disability Status Scale (EDSS score and MRI findings determined disease activity. Linear regression was used to assess the effects of the level of IFN-α on disability (EDSS. IFN-α was determined by sensitive ELISA assays. IFN-α was detectable in sera from 9/36 NMO patients, significantly more often than in the MS group (2/41 (P=0.0197. A higher frequency of IFN-α was observed in NMO patients with acute relapse compared to NMO patients in remission (P<0.001 and compared to the MS patients with relapse (P=0.010. In NMO patients, the levels of IFN-α were significantly associated with EDSS (P=0.0062. It may be concluded that IFN-α was detectable in a subgroup of NMO patients. Association of IFN-α levels with clinical disease activity and severity suggests a role for IFN-α in disease perpetuation and may provide a plausible explanation for a negative effect of IFN-1 treatment in NMO patients.

  8. Autoimmune thyroiditis associated with neuromyelitis optica (NMO

    Directory of Open Access Journals (Sweden)

    Sudulagunta, Sreenivasa Rao

    2015-11-01

    Full Text Available Neuromyelitis optica (NMO or Devic’s syndrome is a rare relapsing demyelinating disease of the central nervous system (CNS that mainly affects the spinal cord and optic nerves and shares many clinical and radiological features with multiple sclerosis. The association of NMO with other autoimmune diseases was reported, but very few reports described association with autoimmune thyroid disease. Early differentiation between NMO and multiple sclerosis is very important as the natural course and treatment regimens differ significantly. We report a case of a 50-year-old woman who was admitted initially with vomiting, hiccups and paraesthesias but was not diagnosed with NMO and presented with a severe progression of the disease. The patient was also diagnosed to have autoimmune thyroiditis with lymphocytic infiltration of the thyroid which progressed from hyperthyroidism to hypothyroidism. NMO diagnosis was established with seropositivity for NMO-IgG and MRI showing longitudinally extensive spinal cord lesions (3 or more spinal segments. In spite of treatment, the response was poor due to lack of early diagnosis and aggressive immunosuppressant therapy.

  9. Magnetic Resonance Imaging Features of Neuromyelitis Optica

    International Nuclear Information System (INIS)

    You, Sun Kyung; Song, Chang June; Park, Woon Ju; Lee, In Ho; Son, Eun Hee

    2013-01-01

    To report the magnetic resonance (MR) imaging features of the spinal cord and brain in patients of neuromyelitis optica (NMO). Between January 2001 and March 2010, the MR images (spinal cord, brain, and orbit) and the clinical and serologic findings of 11 NMO patients were retrospectively reviewed. The contrast-enhancement of the spinal cord was performed (20/23). The presence and pattern of the contrast-enhancement in the spinal cord were classified into 5 types. Acute myelitis was monophasic in 8 patients (8/11, 72.7%); and optic neuritis preceded acute myelitis in most patients. Longitudinally extensive cord lesion (average, 7.3 vertebral segments) was involved. The most common type was the diffuse and subtle enhancement of the spinal cord with a multifocal nodular, linear or segmental intense enhancement (45%). Most of the brain lesions (5/11, 10 lesions) were located in the brain stem, thalamus and callososeptal interphase. Anti-Ro autoantibody was positive in 2 patients, and they showed a high relapse rate of acute myelitis. Anti-NMO IgG was positive in 4 patients (4/7, 66.7%). The imaging findings of acute myelitis in NMO may helpful in making an early diagnosis of NMO which can result in a severe damage to the spinal cord, and to make a differential diagnosis of multiple sclerosis and inflammatory diseases of the spinal cord such as toxocariasis.

  10. Brain MRI abnormalities in neuromyelitis optica

    International Nuclear Information System (INIS)

    Wang Fei; Liu Yaou; Duan Yunyun; Li Kuncheng

    2011-01-01

    Objective: The purpose of this study was to explore brain MRI findings in neuromyelitis optica (NMO) and to investigate specific brain lesions with respect to the localization of aquaporin-4 (AQP-4). Materials and methods: Forty admitted patients (36 women) who satisfied the 2006 criteria of Wingerchuk et al. for NMO were included in this study. All patients received a neurological examination and MRI scanning including brain and spinal cord. MRIs were classified as normal, nonspecific, multiple sclerosis-like, typical abnormalities. MS-like lesions were too few to satisfy the Barkhof et al. criteria for MS. Confluent lesions involving high AQP-4 regions were considered typical. Non-enhancing deep white matter lesions other than MS-like lesions or typical lesions were classified as nonspecific. Results: Brain MRI lesions were delineated in 12 patients (25%). Four patients (10%) had hypothalamus, brainstem or periventricle lesions. Six (15%) patients were nonspecific, and 2 (5%) patients had multiple sclerosis-like lesions. Conclusion: Brain MRIs are negative in most NMO, and brain lesions do not exclude the diagnosis of NMO. Hypothalamus, brainstem or periventricle lesions, corresponding to high sites of AQP-4 in the brain, are indicative of lesions of NMO.

  11. Brain MRI lesions in neuromyelitis optica: clinical case; Lesiones cerebrales de resonancia magnetica en neuromielitis optica: caso clinico

    Energy Technology Data Exchange (ETDEWEB)

    Rosales Bravo, Luis Guillermo; Heyden Cordero, Marvin; Chinchilla Weinstok, Dennis; Mendelewicz Goldwaig, Isaias, E-mail: neurologia.cima@gmail.com [Caja Costarricense del Seguro Social, Hospital Mexico, Div. de Neurologia, San Jose (Costa Rica)

    2011-10-15

    Many cases of patients with neuromyelitis optica have submitted without demyelinating lesions in the cerebral white matter, it has documented that this entity can cause from the onset of illness or through its natural evolution. Diagnostic methods currently as Magnetic Resonance Imaging (MRI) and specific antibodies in plasma (such as antiaquaporin-4) have been diagnosed of neuromyelitis optica cases that were initially confused with multiple sclerosis. Disease in Costa Rica has been little prevalent and is not exactly known what the prevalence and incidence. The degree of disorder is illustrated through a case study, both in the cerebral white matter as spinal cord, in a patient with neuromyelitis optica during a follow-up period of 4 years. This is the first case that has been reported in the scientific literature of Costa Rica. (author) [Spanish] Muchos casos de pacientes con neuromielitis optica se han presentado sin lesiones desmielinizantes en la sustancia blanca cerebral, se ha documentado que esta entidad puede causarlas desde el inicio de la enfermedad o a traves de su evolucion natural. Los metodos de diagnostico en la actualidad como la Imagen por Resonancia Magnetica (IRM) y la determinacion de anticuerpos especificos en plasma (como la antiaquaporina-4) han logrado diagnosticar algunos casos de neuromielitis optica que inicialmente fueron confundidos con esclerosis multiple. La enfermedad en Costa Rica ha sido poco prevalente y no se ha conocido con exactitud cual es la prevalencia e incidencia. El grado de afeccion ha sido ilustrado a traves de un caso clinico, tanto en la sustancia blanca cerebral como espinal, en un paciente con neuromielitis optica durante un periodo de seguimiento de 4 anos. Este es el primer caso que ha sido reportado en la literatura cientifica de Costa Rica. (autor)

  12. Fiber optics for voltage and current measurement; Utilizacion de fibras opticas en la medicion de voltaje y corriente

    Energy Technology Data Exchange (ETDEWEB)

    Mendieta Jimenez, Francisco Javier; Santos Dominguez, Martin; Gutierrez Martinez, Celso [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    This paper offers a brief revision of the techniques employed in the voltage and current measurement in power plants and mention is made also of its main limitations. Likewise the optical methods of transduction of the mentioned electrical variables indicating their advantages and difficulties for its implementation. Finally the activities developed at the Instituto de Investigaciones Elctricas (IIE) in this field are described. [Espanol] En este trabajo se ofrece una breve revision de las tecnicas utilizadas en la medicion de voltaje y corriente en plantas electricas y se mencionan sus principales limitaciones. Asimismo, se presentan los metodos opticos de transduccion de las variables electricas mencionadas, indicando sus ventajas y las dificultades para su realizacion. Finalmente, se describen las actividades que se desarrollan en el Instituto de Investigaciones Electricas (IIE) en este campo.

  13. Desenvolvimento de um sensor de campo eletrico alternado com transmissão por fibra-optica

    OpenAIRE

    Swinka Filho, Vitoldo

    1996-01-01

    Orientador: Rene Robert Dissertação (mestrado) - Universidade Federal do Parana Resumo: Neste trabalho e mostrado o desenvolvimento de um sensor de campo elétrico que utiliza o principio da carga induzida por campo elétrico alternado em superfícies condutoras. O sensor e composto por duas semi-esferas de alumínio isoladas eletricamente e possui um circuito eletrônico incorporado alimentado por baterias, e um sistema de transmissão por fibraoptica ligado a uma unidade remota para leitura...

  14. Neuromyelitis optica-- en vigtig differentialdiagnose til multipel sklerose

    DEFF Research Database (Denmark)

    Holbech, Jakob Vormstrup; Falah, Masoud

    2009-01-01

    Neuromyelitis optica (Devic's disease) is a rare autoimmune neuroinflammatory disease. The disease can often be difficult to distinguish from multiple sclerosis. It is important to be familiar with the disease because of the risk of rapid progression to disability or even death. We describe a 15...

  15. Update on neuromyelitis optica: natural history and management

    Science.gov (United States)

    Jindahra, Panitha; Plant, T

    2012-01-01

    Neuromyelitis optica or Devic disease is an inflammatory disorder of the central nervous system. It is caused by antibodies that attack aquaporin 4 water channels in the cell membrane of astrocytic foot processes at the blood brain barrier. It can involve the optic nerve, the spinal cord and beyond. Here we review its pathophysiology, clinical features, and therapy. PMID:28539779

  16. [A treatment of neuromyelitis optica (Devic's disease) during pregnancy].

    Science.gov (United States)

    Daouda, Moussa Toudou; Obenda, Norlin Samuel; Assadeck, Hamid; Camara, Diankanagbe; Djibo, Fatimata Hassane

    2016-01-01

    Neuromyelitis optica (Devic's disease) is an inflammatory demyelinating disease of the central nervous system that mainly affects spinal cord, optic nerve and brain regions with high aquaporin 4 antigen expression. This is a severe autoimmune disease caused by autoantibodies directed against aquaporin 4 and associated with high morbidity and mortality. Unlike other inflammatory conditions such as multiple sclerosis or rheumatoid polyarthritis, pregnancy does not seem to influence the activity of neuromyelitis optica, hence the need for a thorough treatment during pregnancy. Corticosteroid therapy is the treatment of choice for neuromyelitis optica during pregnancy. Other treatments may also be used including rituximab, some immunosuppressive agents and immunoglobulins. Immunosuppressive treatment or rituximab is recommended when the long-term corticosteroid treatment is contraindicated, in case of inefficiency or if side effects are intolerable. Immunoglobulins are administered to patients with serious outbreaks of neuromyelitis optica which do not respond to bolus methylprednisolone. Immunoglobulins alone can also be continued at a dose of 0.4 g/kg/day for 6-8 weeks until delivery. Plasmapheresis is also a good alternative to bolus methylprednisolone when outbreaks are extremely severe.

  17. OPTICA: Our Path Together Initiating Cultural Access. Final Report.

    Science.gov (United States)

    Jackson, Susan, Comp.

    This final report describes the activities and outcomes of OPTICA (Our Path Together Initiating Cultural Access) programs. For each program an information sheet indicates the goal, total participation, status of the goal, and activities of the program. Programs included: (1) Hands On: ASL Creative Story Telling, a program that used children's…

  18. Structural MRI substrates of cognitive impairment in neuromyelitis optica

    NARCIS (Netherlands)

    Liu, Y.; Fu, Y.; Schoonheim, M.M.; Zhang, N.; Fan, M.L.; Su, L.; Shen, Y.; Yan, Y.P.; Yang, L.; Wang, Q.H.; Zhang, N.N.N.; Yu, C.S.; Barkhof, F.; Shi, F.D.

    2015-01-01

    Objective: To identify the clinical and structural MRI markers for predicting cognitive impairment (CI) in patients with neuromyelitis optica (NMO). Methods: Fifty-four patients with NMO and 27 healthy controls underwent extensive neuropsychological testing and multimodal 3.0T MRI. The patient group

  19. Neuromyelitis optica with clinical and histopathological involvement of the brain.

    NARCIS (Netherlands)

    Hengstman, G.J.D.; Wesseling, P.; Frenken, C.W.; Jongen, P.J.H.

    2007-01-01

    Diagnostic criteria for neuromyelitis optica (NMO) state that there should be no active disease outside the optic nerves and spinal cord. However, several cases have been described with symptomatic brain involvement. We describe an autopsy case of a patient with NMO and symptomatic involvement of

  20. Materiales compuestos C/SiC para aplicaciones estructurales de alta temperatura. Parte I: estabilidad termodinámica y química

    Directory of Open Access Journals (Sweden)

    Aparicio, M.

    2000-12-01

    Full Text Available The development of aero-engine and aircraft industry is aimed to hypersonic technology, efficiency enhancements and pollutant emission reductions. This objective can only be reached by increasing the operating temperatures, utilising new materials which mechanical properties are retained up to high temperatures. SiC matrix composites reinforced with carbon fibres (C/SiC are good examples with very good bending and thermal shock resistance at temperatures up to 1600ºC as well as low density. However, the fact which currently inhibits the application of these materials is the high oxidation rate of carbon fibres at temperatures above 450ºC. In the first part of the paper, a review of the most important properties and oxidation mechanisms of C and SiC has been carried out. The influence of each material disposition, individually and as composite, has been analysed.

    El desarrollo de la industria aeroespacial se orienta actualmente hacia la tecnología hipersónica, el incremento en el rendimiento de las reacciones de combustión y la reducción de la emisión de contaminantes. Estos objetivos sólo pueden alcanzarse aumentando la temperatura de combustión, para lo cual es necesario desarrollar nuevos materiales que conserven sus propiedades mecánicas hasta temperaturas muy elevadas. Entre ellos se encuentran los materiales compuestos de matriz de SiC reforzada con fibra continua de carbono (C/SiC, cuyas propiedades más importantes son una elevada resistencia a flexión y al choque térmico desde temperatura ambiente hasta 1600ºCy su reducido peso específico. Sin embargo, el principal problema que acompaña a los materiales compuestos C/SiC es la elevada velocidad de oxidación de la fibra de carbono a partir de 450ºC. En la primera parte del trabajo se realiza una revisión de las características más relevantes del carbono y SiC, y de su comportamiento frente a la oxidación, tanto por separado como formando parte de materiales

  1. Clinical evaluation of rituximab treatment for neuromyelitis optica.

    Science.gov (United States)

    Fernández-Megía, M J; Casanova-Estruch, B; Pérez-Miralles, F; Ruiz-Ramos, J; Alcalá-Vicente, C; Poveda-Andrés, J L

    2015-10-01

    Neuromyelitis optica is an inflammatory and usually relapsing demyelinating autoimmune disease of the central nervous system that targets the optic nerves and spinal cord. Rituximab has been used for different neurological diseases that are probably immune-mediated or involving humoural immunity. The objective of this study is to evaluate the efficacy and safety of rituximab as treatment for neuromyelitis optica in a tertiary hospital. Retrospective study of patients with neuromyelitis optica treated with rituximab 1000mg on days 1 and 15, repeated every 6 to 8 months. We recorded EDSS score, relapse rate, overall condition, CD19+ count, presence of anti-NMO antibodies, and possible adverse reactions. Six patients were treated; all were women with a median age of 46 years (range, 38-58). Anti-NMO antibodies were detected in 3 patients (50%). Baseline EDSS was 4 (range 2.0-5.5). Two patients had previously been treated with an immunomodulatory drug. Median time from the first rituximab infusion to first relapse was 3.7 years (range 1.7-6.9). Two patients had infusion reactions after the first dose of rituximab. Four patients remained relapse-free and their EDSS score did not progress during rituximab treatment, one patient showed no clinical improvement, and one patient could not be evaluated. Rituximab can be considered an attractive therapeutic alternative for patients with neuromyelitis optica as there are no approved treatments for this disease. Further studies with rituximab are needed to establish the role of this drug in treating neuromyelitis optica. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

  2. Characterization of neuromyelitis optica and neuromyelitis optica spectrum disorder patients with a late onset.

    Science.gov (United States)

    Collongues, N; Marignier, R; Jacob, A; Leite, M I; Siva, A; Paul, F; Zephir, H; Akman-Demir, G; Elsone, L; Jarius, S; Papeix, C; Mutch, K; Saip, S; Wildemann, B; Kitley, J; Karabudak, R; Aktas, O; Kuscu, D; Altintas, A; Palace, J; Confavreux, C; De Seze, J

    2014-07-01

    Few data are available for patients with a late onset (≥ 50 years) of neuromyelitis optica (LONMO) or neuromyelitis optica spectrum disease (LONMOSD), defined by an optic neuritis/longitudinally extensive transverse myelitis with aquaporin-4 antibodies (AQP4-Ab). To characterize LONMO and LONMOSD, and to analyze their predictive factors of disability and death. We identified 430 patients from four cohorts of NMO/NMOSD in France, Germany, Turkey and UK. We extracted the late onset patients and analyzed them for predictive factors of disability and death, using the Cox proportional model. We followed up on 63 patients with LONMO and 45 with LONMOSD during a mean of 4.6 years. This LONMO/LONMOSD cohort was mainly of Caucasian origin (93%), women (80%), seropositive for AQP4-Ab (85%) and from 50 to 82.5 years of age at onset. No progressive course was noted. At last follow-up, the median Expanded Disability Status Scale (EDSS) scores were 5.5 and 6 in the LONMO and LONMOSD groups, respectively. Outcome was mainly characterized by motor disability and relatively good visual function. At last follow-up, 14 patients had died, including seven (50%) due to acute myelitis and six (43%) because of opportunistic infections. The EDSS 4 score was independently predicted by an older age at onset, as a continuous variable after 50 years of age. Death was predicted by two independent factors: an older age at onset and a high annualized relapse rate. LONMO/LONMOSD is particularly severe, with a high rate of motor impairment and death. © The Author(s) 2013.

  3. Trigeminal root entry zone involvement in neuromyelitis optica and multiple sclerosis.

    Science.gov (United States)

    Sugiyama, Atsuhiko; Mori, Masahiro; Masuda, Hiroki; Uchida, Tomohiko; Muto, Mayumi; Uzawa, Akiyuki; Ito, Shoichi; Kuwabara, Satoshi

    2015-08-15

    Trigeminal root entry zone abnormality on brain magnetic resonance imaging has been frequently reported in multiple sclerosis patients, but it has not been investigated in neuromyelitis optica patients. Brain magnetic resonance imaging of 128 consecutive multiple sclerosis patients and 46 neuromyelitis optica patients was evaluated. Trigeminal root entry zone abnormality was present in 11 (8.6%) of the multiple sclerosis patients and two (4.3%) of the neuromyelitis optica patients. The pontine trigeminal root entry zone may be involved in both multiple sclerosis and neuromyelitis optica. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Gray Matter Volume Reduction Is Associated with Cognitive Impairment in Neuromyelitis Optica.

    Science.gov (United States)

    Wang, Q; Zhang, N; Qin, W; Li, Y; Fu, Y; Li, T; Shao, J; Yang, L; Shi, F-D; Yu, C

    2015-10-01

    Whether gray matter impairment occurs in neuromyelitis optica is a matter of ongoing debate, and the association of gray matter impairment with cognitive deficits remains largely unknown. The purpose of this study was to investigate gray matter volume reductions and their association with cognitive decline in patients with neuromyelitis optica. This study included 50 patients with neuromyelitis optica and 50 sex-, age-, handedness-, and education-matched healthy subjects who underwent high-resolution structural MR imaging examinations and a battery of cognitive assessments. Gray matter volume and cognitive differences were compared between the 2 groups. The correlations of the regional gray matter volume with cognitive scores and clinical variables were explored in the patients with neuromyelitis optica. Compared with healthy controls (635.9 ± 51.18 mL), patients with neuromyelitis optica (602.8 ± 51.03 mL) had a 5.21% decrease in the mean gray matter volume of the whole brain (P optica affected the frontal and temporal cortices and the right thalamus (false discovery rate correction, P optica (Alphasim correction, P optica had impairments in memory, information processing speed, and verbal fluency (P optica and is associated with cognitive impairment and disease severity in this group. © 2015 by American Journal of Neuroradiology.

  5. Reactividad matriz-refuerzo en compuestos de matriz de titanio pulvimetalúrgico

    Directory of Open Access Journals (Sweden)

    Amigó, V.

    2007-12-01

    Full Text Available The high reactivity of titanium and the facility of the same one to form intermetallics makes difficult obtaining composites with this material and brings the need in any case of covering the principal fibres used as reinforcement. To obtain composites of titanium reinforced with ceramic particles is proposed in this paper, and for this reason it turns out to be fundamental to evaluate the reactivity between the matrix and reinforcement. Both titanium nitride and carbide (TiN and TiC are investigated as materials of low reactivity whereas titanium silicide (TiSi2 is also studied as materials of major reactivity, already stated by the scientific community. This reactivity will be analyzed by means of scanning electron microscopy (SEM there being obtained distribution maps of the elements that allow to establish the possible influence of the sintering temperature and time. Hereby the matrix-reinforcement interactions are optimized to obtain suitable mechanical properties.

    La elevada reactividad del titanio y la facilidad del mismo en formar intermetálicos dificulta la obtención de compuestos con este material y la necesidad, en todo caso, de recurrir al recubrimiento de las principales fibras utilizadas como refuerzo. Se propone obtener compuestos de titanio reforzados con partículas cerámicas y, por ello, resulta fundamental evaluar la reactividad entre los diferentes materiales. Se investiga como materiales de baja reactividad el nitruro y carburo de titanio y como materiales de mayor reactividad, ya constatada por la comunidad científica, el TiSi2. Esta reactividad se analizará mediante microscopía electrónica de barrido obteniéndose mapas de distribución de los elementos, que permiten establecer la posible influencia de la temperatura de sinterización y el tiempo de permanencia a éstas. De esta manera, se optimiza en lo posible las interacciones matriz-refuerzo para obtener unas propiedades mec

  6. Estudio del comportamiento tribológico de materiales compuestos

    OpenAIRE

    Planells Torres, Mariano

    2017-01-01

    Los materiales compuestos se utilizan cada vez más en el diseño de piezas estructurales para la fabricación de automóviles con el fin de fabricar vehículos más ligeros, más seguros y más eficientes. Para obtener las piezas deseadas, los materiales compuestos se deben conformar en las geometrías elegidas por medio de herramientas de conformación a la temperatura de curado necesaria. El conocimiento de la interacción material-herramienta durante los procesos de conformado es crucial durante el ...

  7. Influencia del envejecimiento higrotérmico en el comportamiento a fractura de compuestos de matriz termoplástica

    Directory of Open Access Journals (Sweden)

    Zenasni, R.

    2004-04-01

    Full Text Available Aging was carried out by introducing the materials into a climatic chamber under appropriate conditions of temperature, humidity and time. The materials are made of two types of weaving (2/2 Twill, 8H Satin glass fibre, and (8H Satin carbon fibre. The matrix was polyetherimide(PEI. In order to characterize the interlaminar fracture a mechanical test was carried out using the mode I Double Cantilever Beam (DCB and mode II End Notched Fixed (ENF tests. The analysis consists of knowing the different failure mechanisms which have generated the hygrothermal aging.

    En este trabajo se realiza un estudio sobre la influencia del envejecimiento higrotérmico en el comportamiento a fractura interlaminar de tres tipos de compuestos, dos de ellos reforzados con tejido de fibra de vidrio(2/2 Twill, y 8H Satin y otro con fibra de carbono (8H Satin . El envejecimiento se realizó manteniendo, durante diferentes periodos de tiempo, probetas en una cámara climática bajo unas determinadas condiciones de temperatura y humedad relativa. La determinación de la tenacidad a fractura interlaminar se realizó utilizando probetas de modos I (DCB y II (ENF. El análisis realizado consistió en poner de manifiesto los diferentes mecanismos de rotura a fractura que se generan tras someter las probetas a la exposición higrotérmica. De los resultados de los ensayos se concluye un diferente comportamiento a fractura según el refuerzo existente y también a igual refuerzo, según la trama del tejido.

  8. Uso da Fibra de Coco em Betão

    OpenAIRE

    Gonçalves, Stephanie Assunção

    2016-01-01

    O presente trabalho tem como objetivo avaliar as resistências à compressão axial, tração por compressão diametral e tração na flexão, módulos de elasticidade estático e dinâmico do betão reforçado com fibra de coco (BRFC), tendo como referência o betão preparado sem a adição de fibra. A escolha da fibra natural decorreu da necessidade de utilizar os resíduos gerados pelo consumo do coco verde. Sendo assim, este trabalho apresenta uma breve história do betão, suas propriedades, tipos de fibras...

  9. Study of a hybrid solar-electric oven to the curing composite materials used in aeronautics; Estudio de un horno hibrido solar-electrico para el curado de materiales compuestos utilizados en aeronautica

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Roman, M. A.; Pineda Pinon, J.; Sanchez Sanchez, A. [CICATA - Unidad Queretaro, Santiago de Queretaro, Queretaro (Mexico)]. E-mail: mhernandezr0900@ipn.mx

    2010-11-15

    The study covers the curing of advanced composites in a hybrid solar electric oven. The furnace uses electricity from the grid power and solar energy provided by the heliostat concentrator system. The materials used in the experiments will be composite materials such as prepreg. The prepreg are fiberglass and carbon fiber. The resin used in the pre-impregnate will be epoxy resin. The work temperatures inside the furnace will be maximum 300 degrees Celsius. The obtained results will be useful to characterize the use of the solar energy and the characterize of the curing chamber. [Spanish] Se presenta el alcance para el estudio, el cual abarca el curado de materiales compuestos avanzados dentro de un horno hibrido solar electrico. El horno utilizara energia electrica suministrada por la red y energia solar suministrada por el sistema heliostato concentrador. Los materiales utilizados en los experimentos seran materiales compuestos tipo prepreg. Los prepreg seran de fibra de vidrio y de fibra de carbono. La resina utilizada en el preimpregando sera resina epoxica. Las temperaturas de trabajo dentro del horno seran como maximo de 300 grados centigrados. Los resultados obtenidos serviran para caracterizar el uso y aprovechamiento de la energia solar y la caracterizacion de la camara de curado.

  10. Neuro-ophthalmic manifestation of neuromyelitis optica spectrum disorders

    Directory of Open Access Journals (Sweden)

    Xiao-jun ZHANG

    2014-10-01

    Full Text Available Neuromyelitis optica spectrum disorders (NMOSDs include classic neuromyelitis optica (NMO, opticospinal multiple sclerosis (OSMS, limited form of NMO and isolated optic neuritis or myelitis accompanied by either systemic autoimmune diseases or typical MRI findings of NMO. The common neuro-ophthalmic features of NMOSDs include simultaneous or consecutive bilateral optic neuritis, more commonly seen optic disk edema and surrounding exudate, poor visual recovery, steroid responsiveness and dependency. Combined with serum aquaporin 4 (AQP4 antibody and brain MRI examination, these clinical features can be helpful to the early differential diagnosis between NMOSDs and MS. Some types of eye movement abnormalities have been reported in patients with NMOSDs, but further investigation needs to be done before the specificity of these features are confirmed. doi: 10.3969/j.issn.1672-6731.2014.10.003

  11. Neuromyelitis optica-like pathology is dependent on type I interferon response

    DEFF Research Database (Denmark)

    Khorooshi, Reza; Wlodarczyk, Agnieszka; Asgari, Nasrin

    2013-01-01

    Neuromyelitis optica is an antibody-mediated autoimmune inflammatory disease of the central nervous system. Reports have suggested that interferon beta which is beneficial for multiple sclerosis, exacerbates neuromyelitis optica. Our aim was to determine whether type I interferon plays a role in ...

  12. Imaging Surrogates of Disease Activity in Neuromyelitis Optica Allow Distinction from Multiple Sclerosis.

    Science.gov (United States)

    Matthews, Lucy; Kolind, Shannon; Brazier, Alix; Leite, Maria Isabel; Brooks, Jonathan; Traboulsee, Anthony; Jenkinson, Mark; Johansen-Berg, Heidi; Palace, Jacqueline

    2015-01-01

    Inflammatory demyelinating lesions of the central nervous system are a common feature of both neuromyelitis optica and multiple sclerosis. Despite this similarity, it is evident clinically that the accumulation of disability in patients with neuromyelitis optica is relapse related and that a progressive phase is very uncommon. This poses the question whether there is any pathological evidence of disease activity or neurodegeneration in neuromyelitis optica between relapses. To investigate this we conducted a longitudinal advanced MRI study of the brain and spinal cord in neuromyelitis optica patients, comparing to patients with multiple sclerosis and controls. We found both cross-sectional and longitudinal evidence of diffusely distributed neurodegenerative surrogates in the multiple sclerosis group (including thalamic atrophy, cervical cord atrophy and progressive widespread diffusion and myelin water imaging abnormalities in the normal appearing white matter) but not in those with neuromyelitis optica, where localised abnormalities in the optic radiations of those with severe visual impairment were noted. In addition, between relapses, there were no new silent brain lesions in the neuromyelitis optica group. These findings indicate that global central nervous system neurodegeneration is not a feature of neuromyelitis optica. The work also questions the theory that neurodegeneration in multiple sclerosis is a chronic sequela to prior inflammatory and demyelinating pathology, as this has not been found to be the case in neuromyelitis optica where the lesions are often more destructive.

  13. Imaging Surrogates of Disease Activity in Neuromyelitis Optica Allow Distinction from Multiple Sclerosis.

    Directory of Open Access Journals (Sweden)

    Lucy Matthews

    Full Text Available Inflammatory demyelinating lesions of the central nervous system are a common feature of both neuromyelitis optica and multiple sclerosis. Despite this similarity, it is evident clinically that the accumulation of disability in patients with neuromyelitis optica is relapse related and that a progressive phase is very uncommon. This poses the question whether there is any pathological evidence of disease activity or neurodegeneration in neuromyelitis optica between relapses. To investigate this we conducted a longitudinal advanced MRI study of the brain and spinal cord in neuromyelitis optica patients, comparing to patients with multiple sclerosis and controls. We found both cross-sectional and longitudinal evidence of diffusely distributed neurodegenerative surrogates in the multiple sclerosis group (including thalamic atrophy, cervical cord atrophy and progressive widespread diffusion and myelin water imaging abnormalities in the normal appearing white matter but not in those with neuromyelitis optica, where localised abnormalities in the optic radiations of those with severe visual impairment were noted. In addition, between relapses, there were no new silent brain lesions in the neuromyelitis optica group. These findings indicate that global central nervous system neurodegeneration is not a feature of neuromyelitis optica. The work also questions the theory that neurodegeneration in multiple sclerosis is a chronic sequela to prior inflammatory and demyelinating pathology, as this has not been found to be the case in neuromyelitis optica where the lesions are often more destructive.

  14. Subclinical primary retinal pathology in neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Jeong, In Hye; Kim, Ho Jin; Kim, Nam-Hee; Jeong, Kyoung Sook; Park, Choul Yong

    2016-07-01

    Foveal thickness may be a more sensitive indicator of primary retinal pathology than retinal nerve fiber layer thickness since the fovea contains no or sparse retinal nerve fiber layer, which coalesces into axons of the optic nerve. To our knowledge, few quantitative in vivo studies have investigated foveal thickness. By using optical coherence tomography, we measured foveal thickness to evaluate intrinsic retinal pathology. Seventy-two neuromyelitis optica spectrum disorder patients (99 eyes with optic neuritis and 45 eyes without optic neuritis) and 34 age-matched controls were included. Foveal thinning was observed both in eyes with non-optic neuritis (185.1 µm, p optica spectrum disorder, foveal thickness correlated with 2.5 % low contrast visual acuity, while retinal nerve fiber layer thickness correlated with high or low contrast visual acuity, extended disability status scale, and disease duration. In this study, we observed foveal thinning irrespective of optic neuritis; thus, we believe that subclinical primary retinal pathology, prior to retinal nerve fiber layer thinning, may exist in neuromyelitis optica spectrum disorder.

  15. Systemic manifestations and pathogenesis exploration of neuromyelitis optica spectrum disorders

    Directory of Open Access Journals (Sweden)

    Hong JIANG

    2014-09-01

    Full Text Available Objective To investigate the immunological abnormalities beyond central nervous system (CNS associated with neuromyelitis optica spectrum disorders (NMOSDs.  Methods Clinical data of 56 patients with NMOSDs from January 2010 to December 2013 enrolled in Department of Neurology at Peking University People's Hospital were analyzed retrospectively. All patients were divided into 2 groups: neuromyelitis optica (N = 33 and non-neuromyelitis optica (N = 23. Each patient underwent detailed physical examination including internal medicine and nervous system. Records of complicated autoimmune diseases as well as scoring of Expanded Disability Status Scale (EDSS were used to evaluate disease severity. Part of patients received detection of multiple immunological indicators.  Results In all patients with NMOSDs, there were 3 cases with Hashimoto thyroiditis, one case with systemic lupus erythematosus (SLE and Sjögren's syndrome (SS, asthma, hyperthyroidism, rheumatoid arthritis and iridocyclitis, respectively. In patients whose immunological indices were available, the first three abnormal immunological changes were abnormal thyroid function (10/17, positive anti-nuclear antibody (14/28 and positive complement 3 (8/19. In addition, NMOSDs got worsen in 2 cases after delivery.  Conclusions NMOSDs coexist with many kinds of autoimmune diseases and multiple autoantibodies. The above-mentioned autoimmunity may be related to the pathogenesis of NMOSDs. Besides, pregnancy or delivery may aggravate the disease severity of NMOSDs. doi: 10.3969/j.issn.1672-6731.2014.09.009

  16. Compuestos bioactivos en harinas integrales y salvados de arroz (Oryza sativa L. Bioactive compounds in rice (Oryza sativa L. | Wholemeals and brans

    Directory of Open Access Journals (Sweden)

    Carlos Aguilar-García

    2017-10-01

    Full Text Available El consumo regular de granos enteros y sus productos puede reducir el riesgo de enfermedades crónicas tales como: las cardiovasculares, diabetes tipo II y algunos tipos de cáncer. El objetivo de este estudio fue evaluar el contenido de compuestos bioactivos en harinas integrales y salvados de arroz (variedades: Cimarrón, FONAIAP 1 y Zeta 15, tales como: fibra dietética total (FDT, determinada por método enzimático-gravimétrico; inhibidores de tripsina (IT, ácido fítico (AF y taninos condensados (TC, cuantificados por colorimetría. Se encontraron diferencias significativas (p < 0,05 para los compuestos bioactivos entre las harinas integrales y los salvados. Los salvados son una fuente rica de FDT, AF y TC. La variedad Cimarrón exhibió el mayor contenido de FDT, en el salvado (40,61 ± 0,10% y en la harina (14,04 ± 0,12%; mientras que la FONAIAP 1 mostró el menor contenido en el salvado (33,67 ± 0,64% y la harina (11,44 ± 0,24%. Los IT en harinas y salvados presentaron un intervalo de 5,70 ± 0,02 a 6,35 ± 0,35 mg/g en todas las variedades, excepto en la harina Zeta 15 (3,72 ± 0,04 mg/g. Las concentraciones de AF y TC en los salvados, presentaron valores significativamente superiores con respecto a las harinas integrales. Los hallazgos demostraron que las harinas integrales y los salvados de arroz analizados en este estudio, pueden suministrar a la dieta importantes compuestos bioactivos (FDT, IT, AF y TC de gran significancia para la salud. Los salvados mostraron ser una fracción del arroz con alta concentración de FDT, AF y TC.

  17. Simulación numérica del comportamiento elástico del concreto reforzado con fibras cortas de acero en condición plana de esfuerzos

    Directory of Open Access Journals (Sweden)

    Fabian Lamus

    2011-01-01

    Full Text Available Este trabajo describe un modelo numérico implementado en el método de los elementos finitos (Hughes, 2000, el cual permite simular el comportamiento elástico del concreto reforzado con fibras cortas de dirección aleatoria. En estructuras hechas de dicho material cada punto está compuesto por fibras cortas de acero embebidas en una matriz de concreto simple. En el interior de un elemento finito el concreto reforzado se representa como un material ortótropo de dirección material aleatoria, basado en el modelo de fibras con diámetro despreciable (Dvorak y Bahei-el-Din, 1982 y la teoría de mezclas modificada para refuerzo de corta longitud (Oller, 2003. El análisis estadístico realizado consiste en: repetir la simulación numérica del problema cambiando la dirección de las fibras mediante una función aleatoria, construir la base de datos de muestreo a partir de los resultados obtenidos y medir la dispersión de estos últimos. A continuación, en este trabajo se estudia la sensibilidad del tamaño de los elementos finitos y del número de datos de muestreo en el cálculo de la energía total de deformación y se establecen algunos valores recomendables. Como ejemplo de aplicación se obtuvo la respuesta estructural promedio de una viga de concreto reforzado con diferentes cuantías de fibras cortas de acero, observando una dispersión mínima de los datos.

  18. Estudio de la Dinámica de los Procesos de Fractura y de Delaminación en Materiales Reforzados con Fibras

    Directory of Open Access Journals (Sweden)

    Pedro Tamayo-Meza

    2014-01-01

    Full Text Available El estudio de los efectos dinámicos, relacionados con la falla de las fibras, comienza con el análisis de algunos modelos que consideran el carácter dinámico de la redistribución del esfuerzo en el compuesto. Se deduce una ecuación para el deslizamiento de los filamentos fracturados y para los filamentos que rodean éstos, para el caso cuando los componentes se deforman elásticamente, para una deformación de cizalle elasto-plástico de la matriz, y para el filamento fracturado exfoliado de la matriz. Se obtiene una solución analítica, y se brinda un análisis de la propagación de la onda del esfuerzo en el filamento fracturado cuando los componentes del material se deforman elásticamente.

  19. Comportamiento a tracción de cementos reforzados con fibras de vidrio

    Directory of Open Access Journals (Sweden)

    Sánchez Paradela, M. Laura

    1991-06-01

    Full Text Available Glassfibre Reinforced Cement (GRC is a composite material widely used in the field of building construction. It offers multiple applications due to its high strength as well as fire and corrosoón resistance. However, it degradates with time, affecting its mechanical properties, mainly its ductility, becoming progressively brittle and cracking under low deformations. Therefore, with the aim of predicting the mechanical behaviour of the material, both at short time and long time, a wide experimental program has been carried out, testing fresh material as well as aged material. A high number of tensile tests have been performed, using GRC specimens with different kind of fibres and different manufacturing processes for comparison of results. It must be pointed out that it is the first time that tensile tests of GRC specimens have been carried out in Spain.

    El cemento reforzado con fibras de vidrio (GRC es un material compuesto que se viene utilizando ampliamente en el campo de la Construcción. Presenta múltiples aplicaciones debido a sus buenas propiedades resistentes y de protección frente al fuego y la corrosión. Sin embargo, sufre un deterioro con el tiempo, que afecta a sus propiedades mecánicas, principalmente a su ductilidad, volviéndose frágil y agrietándose bajo pequeñas deformaciones. Por tal motivo y con el fin de predecir el comportamiento mecánico del material a corto y a largo plazo, se ha desarrollado un extenso programa experimental, empleando tanto material joven como envejecido. Se han realizado numerosos ensayos de tracción directa, utilizando probetas de GRC con diversos tipos de fibras y empleando distintos métodos de fabricación para una comparación de resultados. Es la primera vez que se realizan ensayos de tracción directa en España sobre probetas de GRC.

  20. FIBRAS DE CARBONO NA CONSTRUÇÃO CIVIL

    Directory of Open Access Journals (Sweden)

    Nicolas Montanari

    2017-02-01

    Full Text Available Os materiais compósitos se dão pela utilização de dois, ou mais, materiais trabalhando de forma conjunta com o propósito de alcançar determinada propriedade a qual não seria possível com os mesmos isolados. A fibra de carbono com resina epóxi utilizada em reforços estruturais é um desses materiais, a grande resistência mecânica à tração e elevado módulo de elasticidade tornam a fibra de carbono adequada do ponto de vista estrutural, e com a resina epóxi atuando de modo a transferir as tensões da estrutura para serem resistidas pela fibra a caracteriza como tal. Este processo de reforço já vem se mostrando uma alternativa a métodos tradicionais, é mais rápido, simples e limpo que outros, clientes vem optando por este processo mesmo que apresente custo final mais elevado, pois quando consideradas as vantagens nele embutidas torna-se viável. Muito já se desenvolveu com a fibra de carbono no ramo da construção civil, porém ainda pode ser feito mais, descobrindo e aperfeiçoando novas técnicas construtivas compostas de materiais com fibra de carbono.

  1. Compuestos beta-lactámicos inhibidores de APAF1

    OpenAIRE

    Messeguer Peypoch, Ángel; Alfonso, Ignacio; Corredor, Miriam; Pérez-Payá, Enrique; Orzáez Calatayud, Mar

    2012-01-01

    La presente invención se refiere a compuestos para la prevención y/o tratamiento de trastornos causados por muerte celular por apoptosis o para la prevención de procesos degenerativos causados por la muerte celular por apoptosis, a través de la inhibición del factor de activación de la peptidasa apoptótica 1 (APAF1, Apoptotic Peptidase Activating Factor 1)

  2. Microextracción en fase sólida de compuestos volátiles en albahaca (Ocimum basilicum L. Microextracción en fase sólida de compuestos volátiles en albahaca (Ocimum basilicum L.

    Directory of Open Access Journals (Sweden)

    Isaac Andrade-González

    2012-02-01

    Full Text Available Volatile compounds of basil (Ocimum basilicum L. were extracted with solid phase microextraction(SPME and analyzed with gas chromatography-mass spectrometry (GC-MS. TwoSPME fiber coatings, Polydimethylsiloxane/Divinylbenzene (PDMS/DVB, 65 μm and Carbowax/Divinylbenzene (CW/DVB, 65 μm were evaluated in order to compare the extraction ofcomponents. Among the 25 volatile compounds detected were phenylpropanoids, monoterpenes,sesquiterpenes, esters, and aldehydes. There were significant (P Los compuestos volátiles de la albahaca (Ocimum basilicum L. fueron extraídos mediante la microextracción en fase sólida (SPME y analizados con cromatografía de gases-espectrometría de masas (GC-MS. Se evaluaron dos fibras, Polidimetilsiloxano/Divinilbenceno (PDMS/DVB, 65 μm y Carbowax/Divinilbenceno (CW/DVB, 65 μm, para comparar la extracción de componentes. Entre los 25 compuestos volátiles recuperados en la albahaca, se identificaron fenilpropanoides, monoterpenos, sesquiterpenos, ésteres, y aldehídos. Hubieron diferencias significativas (P Cuantitativamente, el componente más importante fue el cinamato de metilo, seguido por el linalol.

  3. Brainstem and limbic encephalitis with paraneoplastic neuromyelitis optica.

    Science.gov (United States)

    Moussawi, Khaled; Lin, David J; Matiello, Marcelo; Chew, Sheena; Morganstern, Daniel; Vaitkevicius, Henrikas

    2016-01-01

    The spectrum of disorders associated with anti-neuromyelitis optica (NMO) antibody is being extended to include infrequent instances associated with cancer. We describe a patient with brainstem and limbic encephalitis from NMO-immunoglobulin G in serum and cerebrospinal fluid in the context of newly diagnosed breast cancer. The neurological features markedly improved with excision of her breast cancer and immune suppressive therapy. This case further broadens the NMO spectrum disorders (NMOSD) by an association between NMOSD and cancer and raises the question of coincidental occurrence and the appropriate circumstances to search for a tumor in certain instances of NMO. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. A Case of Neuromyelitis Optica Masquerading as Miller Fisher Syndrome

    Directory of Open Access Journals (Sweden)

    Yuka Furutani

    2014-10-01

    Full Text Available A 22-year-old woman presented with double vision that she had experienced since an infection 2 weeks previously. A neurological examination showed limited bilateral eye abduction, mimicking Miller Fisher syndrome. However, T2-weighted magnetic resonance imaging of her brain revealed hyperintense areas in the tegmentum of the pons, including the abducens nucleus, and her serum anti-aquaporin-4 antibody test was positive. She was finally diagnosed with neuromyelitis optica. Intravenous high-dose steroid therapy immediately improved the patient's abduction palsy, but bilateral optic neuritis manifested during the treatment. Subsequent treatment with plasma exchange improved her optic neuritis symptoms.

  5. Descenso de las propiedades mecánicas del pei reforzado con fibra de vidrio y carbono en ambientes químicos

    Directory of Open Access Journals (Sweden)

    Viña, J.

    2000-08-01

    Full Text Available This work shows how the mechanical properties, tensile and shear strength, are modified in different way if two different types of composite materials are immersed in toluen and sulfuric acid. The composites have a thermoplastic as matrix and one of them is reinforced with glass fiber and the other with carbon fiber. Also the important influence of the temperature has been tested in the case of the acid and specimens with holes have been tested to know their influence.

    El presente trabajo muestra la diferente influencia que sobre las propiedades mecánicas, resistencias a tracción y cortadura, tiene la inmersión en dos agentes químicos, tales como, tolueno y ácido sulfúrico de dos tipos diferentes de materiales compuestos, uno reforzado con fibra de vidrio y otro con fibra de carbono. En ambos casos la matriz empleada es un termoplástico de altas prestaciones denominado PEI. En el caso del ataque con el ácido se ha podido, asimismo, contrastar la importante influencia de la temperatura en la disminución de las resistencias y por último, también se han ensayado, a tracción, probetas que contenían agujeros pasantes para, en este caso, descartar que el aumento de la superficie de ataque aumentaba éste.

  6. Th17 cells in neuromyelitis optica spectrum disorder: a review.

    Science.gov (United States)

    Lin, Jie; Li, Xiang; Xia, Junhui

    2016-12-01

    Neuromyelitis optica spectrum disorder (NMOSD) has been identified as a central nervous system (CNS) autoimmune inflammatory disorder, which has been recognized as a B cell-mediated humoral immune disease. However, cases have been reported indicating that some of the neuromyelitis optica (NMO) patients have been resistant to B cell-related treatments. Recently, more and more evidence has shown that T cell-mediated immunity may take part in the pathogenesis of NMOSD, especially in the Th17 phenotype. In our PUBMED search, we used the following keywords: Th17 cell, Th17 cell-related cytokines, T cells, B cells, B cell-related productions, NMO, NMOSD, recurrent/bilateral optic neuritis, recurrent transverse myelitis and longitudinally extensive transverse myelitis. We systemically reviewed the role of Th17 cells and Th17 cell-related cytokines in NMOSD. We found that Th17 cells and Th17-related cytokines, such as IL-6, IL-1β, IL-17, IL-21, IL-22, IL-23 and TGF-β, are not only directly involved in the pathogenesis but also collaborated with B cells and B cell-related antibody production to induce CNS lesions. Th17 cell-related therapy has also been reviewed in this article, and the data suggested that Th17 may be a new therapeutic target of NMOSD.

  7. Neuromyelitis optica spectrum disorders: beyond longitudinally extensive transverse myelitis

    International Nuclear Information System (INIS)

    Lemos, M.D.; Carvalho, G.B.S.; Carvalho, R.S.; Bichuetti, D.B.; Oliveira, E.M.L. de; Abdala, N.

    2015-01-01

    Aim: To describe the neuroradiological features and their prevalence in patients with neuromyelitis optica (NMO). Materials and methods: Two neuroradiologists independently reviewed 35 spinal cord and 37 brain MRI studies from patients with NMO. The examinations were analysed for the presence of lesion, topography, enhancement, and brain lesions suggestive of multiple sclerosis and/or NMO. Results: Seventy percent of the spinal cord lesions involved over three or more vertebral segments. Seventy-eight percent of brain scans were abnormal, and the most prevalent findings were non-specific foci of T2 hyperintensities in the cerebral white matter (55%) and brainstem lesions (52%). One patient had lesions disseminated in space compatible with multiple sclerosis according to 2010 revised McDonald criteria. Brain lesions suggestive of NMO occurred at least once in 17 (59%) patients. Conclusion: Spinal cord lesions were often longitudinally extensive and brain lesions were common, with the majority of patients having at least one distinctive NMO lesion. - Highlights: • Neuromyelitis optica (NMO) affects mainly the spinal cord but also the brain. • We accessed the radiological features of patients with NMO in brain and spinal cord. • We found a high prevalence of extensive myelitis and specific brain lesions. • Some brainstem lesions could be misdiagnosed if not actively searched. • A practical approach to evaluate suspected NMO images is presented

  8. High risk of postpartum relapses in neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Klawiter, Eric C; Bove, Riley; Elsone, Liene; Alvarez, Enrique; Borisow, Nadja; Cortez, Melissa; Mateen, Farrah; Mealy, Maureen A; Sorum, Jaime; Mutch, Kerry; Tobyne, Sean M; Ruprecht, Klemens; Buckle, Guy; Levy, Michael; Wingerchuk, Dean; Paul, Friedemann; Cross, Anne H; Jacobs, Anu; Chitnis, Tanuja; Weinshenker, Brian

    2017-11-28

    To study the effect of pregnancy on the frequency of neuromyelitis optica spectrum disorder (NMOSD) relapse and evaluate rates of pregnancy-related complications in an international multicenter setting. We administered a standardized survey to 217 women with NMOSD from 7 medical centers and reviewed their medical records. We compared the annualized relapse rate (ARR) during a baseline period 2 years prior to a participant's first pregnancy to that during pregnancy and to the 9 months postpartum. We also assessed pregnancy-related complications. There were 46 informative pregnancies following symptom onset in 31 women with NMOSD. Compared to baseline (0.17), ARR was increased both during pregnancy (0.44; p = 0.035) and during the postpartum period (0.69; p = 0.009). The highest ARR occurred during the first 3 months postpartum (ARR 1.33). A total of 8 of 76 (10.5%) with onset of NMOSD prior to age 40 experienced their initial symptom during the 3 months postpartum, 2.9 times higher than expected. The postpartum period is a particularly high-risk time for initial presentation of NMOSD. In contrast to published observations in multiple sclerosis, in neuromyelitis optica, relapse rate during pregnancy was also increased, although to a lesser extent than after delivery. © 2017 American Academy of Neurology.

  9. Use of advanced magnetic resonance imaging techniques in neuromyelitis optica spectrum disorder

    NARCIS (Netherlands)

    S. Kremer (Stephane); F. Renard (Felix); S. Achard (Sophie); M.A. Lana-Peixoto (Marco A.); J. Palace (Jacqueline); N. Asgari (Nasrin); E.C. Klawiter (Eric C.); S. Tenembaum (Silvia); B. Banwell (Brenda); B.M. Greenberg (Benjamin M.); J.L. Bennett (Jeffrey); M. Levy (Michael); P. Villoslada (Pablo); A. Saiz (Albert Abe); K. Fujihara (Kazuo); K.H. Chan (Koon Ho); S. Schippling (Sven); F. Paul (Friedemann); H.J. Kim (Ho Jin); J. De Seze (Jerome); J.T. Wuerfel (Jens T.); P. Cabre (Philippe); R. Marignier (Romain); T. Tedder (Thomas); E.D. van Pelt - Gravesteijn (Daniëlle); S. Broadley (Simon); T. Chitnis (Tanuja); D. Wingerchuk (Dean); L. Pandit (Lekha); M.I. Leite (M. Isabel); M. Apiwattanakul (Metha); I. Kleiter (Ingo); N. Prayoonwiwat (Naraporn); M. Han (May); K. Hellwig (Kerstin); K. Van Herle (Katja); G. John (Gareth); D.C. Hooper (D. Craig); I. Nakashima (Ichiro); D. Sato (Douglas); M.R. Yeaman (Michael R.); E. Waubant (Emmanuelle); S. Zamvil (Scott); O. Stüve (Olaf); O. Aktas (Orhan); T.J. Smith (Terry J.); A. Jacob (Anu); K. O'Connor (Kevin)

    2015-01-01

    textabstractBrain parenchymal lesions are frequently observed on conventional magnetic resonance imaging (MRI) scans of patients with neuromyelitis optica (NMO) spectrum disorder, but the specific morphological and temporal patterns distinguishing them unequivocally from lesions caused by other

  10. Aquaporin-4 serostatus does not predict response to immunotherapy in neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Mealy, Maureen A; Kim, Su-Hyun; Schmidt, Felix; López, Reydmar; Jimenez Arango, Jorge A; Paul, Friedemann; Wingerchuk, Dean M; Greenberg, Benjamin M; Kim, Ho Jin; Levy, Michael

    2017-08-01

    Debate exists about whether neuromyelitis optica spectrum disorder seronegative disease represents the same immune-mediated attack on astrocytic aquaporin-4 as in seropositive disease. We investigated whether response to common treatments for neuromyelitis optica spectrum disorder differed by serostatus, as assessed by change in annualized relapse rate. We performed a multicenter retrospective analysis of 245 patients with neuromyelitis optica spectrum disorder who were treated with either rituximab or mycophenolate mofetil as their first-line immunosuppressive treatment for disease prevention. Patients were followed for a minimum of 6 months following treatment initiation. In those started on rituximab, the pre-treatment annualized relapse rates for seropositive and seronegative patients were 1.81 and 1.93, respectively. On-treatment annualized relapse rates significantly declined to 0.32 (seropositive; p optica spectrum disorder patients, treatment was effective regardless of serostatus. This suggests that treatment should not differ when considering these treatments.

  11. The Urine Proteome Profile Is Different in Neuromyelitis Optica Compared to Multiple Sclerosis

    DEFF Research Database (Denmark)

    Nielsen, Helle H; Beck, Hans C; Kristensen, Lars P

    2015-01-01

    OBJECTIVES: Inflammatory demyelinating diseases of the CNS comprise a broad spectrum of diseases like neuromyelitis optica (NMO), NMO spectrum disorders (NMO-SD) and multiple sclerosis (MS). Despite clear classification criteria, differentiation can be difficult. We hypothesized that the urine...

  12. Obtenção de nanocompósitos, nanodiamante sobre fibra de carbono e nanotubo de carbono sobre fibra de carbono

    OpenAIRE

    Leonardo Iusuti de Medeiros

    2009-01-01

    A proposta desta dissertação é a obtenção de dois compósitos nanoestruturados que sejam constituídos um por nanodiamante sobre fibra de carbono e, o outro, por nanotubo de carbono sobre a fibra de carbono. Em ambos os compósitos as fibras de carbono usadas são obtidas com três diferentes índices de grafitização 1000, 1500 e 2000°C. As fibras de carbono apresentam uma grande área superficial devido a sua estrutura. Quando utilizadas como substrato para crescimento de materiais nanoestruturados...

  13. Relaciones de equivalencia con estímulos compuestos

    Directory of Open Access Journals (Sweden)

    Aldo Hernández, Sonia Céspedes, Leonardo Prieto

    2007-03-01

    Full Text Available El propósito de la presente investigación fue identificar las relaciones emergentes de entrenamientos entre estímulos muestra simples con estímulos de comparación compuestos. El estudio realizado corresponde a una investigación de tipo intrasujeto. Se contó con diez estudiantes universitarios, seis hombres y cuatro mujeres, con edades entre los 17 y 22 años de edad fueron escogidos por conveniencia y recibieron entrenamiento en discriminación condicional a través de tareas de igualación a la muestra arbitraria de tres elecciones por medio de un aplicativo en Visual Basic. En el primer y segundo bloque de entrenamiento se establecieron las relaciones condicionales entre estímulos muestra simples y estÌmulos de comparación compuestos (ej., A1-B1B1; A2-B2B2; A3-C3C3 y B1-C1C1; B2-C2C2; B3-C3C3 y se conformaron tres clases equivalentes de tres miembros cada una (ej., A1A1-B1B1-C1C1, asÌ como relaciones equivalencia-equivalencia (ej. A1A2- B1B2-C1C2. Cuatro de los diez participantes mostraron relaciones emergentes de simetrÌa, transitividad y equivalencia junto con relaciones equivalencia-equivalencia. Estos hallazgos indican que los entrenamientos entre estímulos simples y compuestos o viceversa producen relaciones emergentes propias de la equivalencia de estímulos.

  14. Odontoma compuesto. Una patología oral a considerar

    Directory of Open Access Journals (Sweden)

    Jonathan Harris Ricardo

    2013-10-01

    Full Text Available Resumen El odontoma es el tumor odontogénico mixto con mayor frecuencia de aparición, las células y los tejidos son normales pero de estructura defectuosa, la etiología se le relaciona con restos paradentales de malassez y traumatismos, son de crecimiento limitado, asintomáticos, producen retención dentaria; se clasifica en compuesto y complejo, radiográficamente se presenta halo radiolúcido con múltiples imágenes radiopacas en su interior, con un patrón ordenado para el odontoma compuesto y en el odontoma complejo se presenta imagen radiopaca como conglomeraciones amorfas, con un patrón desordenado. El tratamiento es quirúrgico y su recurrencia es baja. Se reporta caso de paciente femenina de 30 años de edad, que acudió a la consulta del servicio de estomatología y cirugía oral de la Universidad de Cartagena Colombia, porque presentó, lesión tumoral que comprometía la zona de órganos dentarios 33 y 34, se realizó examen radiográfico, con diagnóstico presuntivo de odontoma compuesto, se programó la cirugía y se realizó enucleación de la lesión tumoral la cual se envió a patología; en el reporte histopatológico se diagnosticó odontoma compuesto. (DUAZARY 2010, 91 - 94Abstract The odontoma is the mixed odontogenic tumor observed with greater frequency. Cells and tissues are normal in structure but is defective in pattern. Etiology is associated with remainders of malassez paradentales tissues and trauma and injuries. They are growing limited, asymptomatic, produce tooth retention. They were classified as compound and complex radiographic radiolucent halo is presented with multiple radiopaque images inside it, with a pattern for the ordered compound odontoma and complex odontoma presents the image as radiopaque amorphous clusters with a disordered pattern. The treatment is surgical and recurrence is low. We report the case of female patient aged 30, who attended the service of dentistry and oral surgery at the

  15. Paucity of natural killer and cytotoxic T cells in human neuromyelitis optica lesions

    Science.gov (United States)

    Saadoun, Samira; Bridges, Leslie R.; Verkman, A. S.; Papadopoulos, Marios C.

    2013-01-01

    Neuromyelitis optica is a severe inflammatory demyelinating disease of the central nervous system. Most patients with neuromyelitis optica have circulating immunoglobulin G (IgG) antibodies against the astrocytic water channel protein aquaporin-4 (AQP4), which are pathogenic. Anti-AQP4 IgG-mediated complement-dependent astrocyte toxicity is a key mechanism of central nervous system damage in neuromyelitis optica, but the role of natural killer and cytotoxic T cells is unknown. Our objective was to determine whether natural killer and cytotoxic T cells play a role in human neuromyelitis optica lesions. We immunostained four actively demyelinating lesions, obtained from patients with anti-AQP4 IgG positive neuromyelitis optica, for Granzyme B and Perforin. The inflammatory cells were perivascular neutrophils, eosinophils and macrophages, with only occasional Granzyme B+ or Perforin + cells. Greater than 95% of inflamed vessels in each lesion had no surrounding Granzyme B+ or Perforin + cells. Granzyme B+ or Perforin+ cells were abundant in human spleen (positive control). Although natural killer cells produce central nervous system damage in mice injected with anti-AQP4 IgG, our findings here indicate that natural killer-mediated and T cell-mediated cytotoxicity are probably not involved in central nervous system damage in human neuromyelitis optica. PMID:23108041

  16. Pediatric familial neuromyelitis optica in two sisters with long term follow-up.

    Science.gov (United States)

    Chuquilin, Miguel; Mullaguri, Naresh; Weinshenker, Brian

    2016-07-01

    Neuromyelitis optica causes bilateral optic neuritis and longitudinal extensive transverse myelitis. Although usually sporadic, 3% of cases of neuromyelitis optica are familial. The interval over which attacks continue and the long term prognosis for pediatric-onset neuromyelitis optica are not well defined. We describe two patients with pediatric familial neuromyelitis optica with the longest clinical follow-up of a pediatric case reported in the literature to our knowledge. One woman developed blindness with bilateral eye involvement within a few weeks at age 3. This was followed by transverse myelitis with paraparesis at age 19 leading to diagnosis of neuromyelitis optica. Her serum anti-aquaporin 4 antibody was later found to be positive. She continued with sporadic myelitis-related relapses but remained ambulant until age 40 when she had a more severe relapse. There was evidence of longitudinal extensive T2 hyperintensity in the thoracic spinal cord. Her sister also developed blindness at age 3.5 followed by myelitis 1year later with multiple relapses of gait impairment until her death from pneumonia at age 21. These patients represent the rare occurrence of neuromyelitis optica in children within the same family and show that this disease can have prolonged periods of remission but a continued tendency to relapse, supporting the need for lifelong immunosuppression. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Actividad antioxidante de los compuestos fenólicos

    Directory of Open Access Journals (Sweden)

    Maestro Durán, R.

    1993-04-01

    Full Text Available This review deals with the oxidation processes induced by light and atmospheric oxygen, as well as the protective action on antioxidant compounds. The available data on the synthetic antioxidants and the problems associated to their use, together with the presence of natural phenolic antioxidants in plants, have been revised. These phenolic antioxidants have been classified in families: phenolic alcohols and acids, cinnamic acids, coumarins, favonoids (flavones and isoflavones, flavonols, flavanones and other phenolic compounds.

    Este trabajo recoge los estudios sobre los mecanismos de oxidación producida por la luz y el oxígeno del aire y sobre la protección de los compuestos antioxidantes contra esta oxidación. Se han revisado los datos existentes sobre los inconvenientes de los antioxidantes sintéticos, que aconsejan sustituirlos por otros naturales y sobre la presencia de antioxidantes naturales de carácter fenólico en las plantas. Los antioxidantes fenólicos se han agrupado por familias: alcoholes y ácidos fenólicos, ácidos cinámicos, cumarinas, flavonoides (flavonas e isoflavonas, flavonoles, flavanonas y otros compuestos fenólicos.

  18. Materiales compuestos C/SiC para aplicaciones estructurales de alta temperatura. Parte II: Sistemas de protección contra la oxidación

    Directory of Open Access Journals (Sweden)

    Aparicio, M.

    2001-02-01

    Full Text Available The fact which currently excludes the use of C/SiC composites in high temperature structural applications is the high oxidation rate of carbon fibres at temperatures higher than 450ºC. In this second part of the paper, a review of the different oxidation protection systems, including inhibitors, surface modification of composites, coatings and previous infiltration of the substrates, has been carried out. The addition of inhibitors reduces the oxidation rate, but only up to 850ºC, while the surface modification of composites leads to thin coatings with poor thermal shock resistance. On the other hand, the external layers are the most usual method employed because allows combining different compositions and thicknesses. The multilayer coatings are especially interesting in applications with wide temperature range and thermal shocks requirements. The infiltration of substrate porosity improves slightly the oxidation resistance of C/SiC composites reducing the oxygen accessibility to carbon fibres. However, the infiltration complements very well the oxidation protection performance of a coating system at low temperature, since these normally present open cracks due to mismatch between coating and substrate thermal expansion coefficients.

    La utilización de los materiales compuestos C/SiC en aplicaciones estructurales a alta temperatura está limitada por la elevada velocidad de oxidación de la fibra de carbono a temperaturas superiores de 450ºC. En esta segunda parte del trabajo se realiza una revisión de las posibilidades de protección contra la oxidación de estos materiales, incluyendo inhibidores, modificación superficial del material compuesto, recubrimientos e infiltración previa del sustrato. La eficacia de los inhibidores de la reacción de oxidación esta restringida a temperaturas de hasta 850ºC, mientras que la modificación superficial del material compuesto da lugar a capas delgadas y poco resistentes a los ciclos t

  19. Finding NMO: The Evolving Diagnostic Criteria of Neuromyelitis Optica

    Science.gov (United States)

    Bennett, Jeffrey L.

    2016-01-01

    Neuromyelitis optica (NMO) is an autoimmune demyelinating disorder of the central nervous system (CNS) with predilection for the optic nerves and spinal cord. Since its emergence in the medical literature in the late 1800’s, the diagnostic criteria for NMO has slowly evolved from the simultaneous presentation of neurologic and ophthalmic signs to a relapsing or monophasic CNS disorder defined by clinical, neuroimaging, and laboratory criteria. Due to the identification of a specific autoantibody response against the astrocyte water channel aquaporin-4 (AQP4) in the vast majority of affected individuals, the clinical spectrum of NMO has greatly expanded necessitating the development of new international criteria for the diagnosis of NMO spectrum disorder (NMOSD). The routine application of new diagnostic criteria for NMOSD in clinical practice will be critical for future refinement and correlation with therapeutic outcomes. PMID:27529327

  20. Visual evoked potentials in neuromyelitis optica and its spectrum disorders.

    Science.gov (United States)

    Ringelstein, Marius; Kleiter, Ingo; Ayzenberg, Ilya; Borisow, Nadja; Paul, Friedemann; Ruprecht, Klemens; Kraemer, Markus; Cohn, Eva; Wildemann, Brigitte; Jarius, Sven; Hartung, Hans-Peter; Aktas, Orhan; Albrecht, Philipp

    2014-04-01

    Optic neuritis (ON) is a key feature of neuromyelitis optica (NMO). Recently, NMO patients of predominantly Afro-Brazilian origin were evaluated by visual evoked potentials (VEPs) and showed marked amplitude reductions. Here, we analyzed VEPs in a predominantly Caucasian cohort, consisting of 43 patients with definite NMO, 18 with anti-aquaporin (AQP) 4 antibody-seropositive NMO spectrum disorders and 61 matched healthy controls. We found reduced amplitudes in only 12.3%, prolonged latencies in 41.9% and a lack of response in 14.0% of NMO eyes. Delayed P100 latencies in eyes without prior ON suggested this was a subclinical affection. The data indicate heterogenous patterns in NMO, warranting further investigation.

  1. Seronegative neuromyelitis optica presenting with life-threatening respiratory failure.

    Science.gov (United States)

    Nardone, Raffaele; Zuccoli, Giulio; Brigo, Francesco; Trinka, Eugen; Fitzgerald, Ryan T

    2016-11-01

    Dyspnea has rarely been reported as a presenting symptom in patients with neuromyelitis optica (NMO). We report an unusual case of NMO relapse presenting with rapidly progressive respiratory failure and briefly discuss the possible pathophysiological mechanisms of this potential life-threatening complication of NMO. The 58-year-old woman with a history of bilateral optic neuritis presented to the emergency department with rapidly worsening dyspnea. Cervical spine magnetic resonance imaging showed extensive abnormal signal with involvement of the medulla oblongata. Since in our patient chest radiography failed to disclose a diaphragmatic palsy that is commonly observed in patients with phrenic nerve involvement, this acute manifestation of the disease may be attributed to brainstem involvement instead of cervical myelitis. Clinicians should be aware of this atypical presentation of NMO, which needs to be promptly recognized and aggressively treated.

  2. Epidemiological, clinical and immunological aspects of neuromyelitis optica (NMO)

    DEFF Research Database (Denmark)

    Asgari, Nasrin

    2013-01-01

    Neuromyelitis optica (NMO) is an inflammatory demyelinating disease (IDD) of the central nervous system (CNS) and probably the most common non-multiple sclerosis (MS) CNS IDD. Serum immunoglobulin G autoantibodies have been identified in the majority of NMO patients with the water channel aquaporin...... on either the Wingerchuk 2006 criteria or the United States National Multiple Sclerosis Society 2008 criteria could be made purely on clinical grounds in a high proportion (64%) of cases. Heterogeneity of clinical NMO manifestations including optic neuritis, longitudinal extensive transverse myelitis (LETM...... with specific clinical, immunogenetic and experimental perspectives. The yearly incidence rate of NMO in the population was estimated to be 0.4 per 105 person-years (95% CI 0.30-0.54) and the prevalence was 4.4 per 105 (95% CI 3.1-5.7). The results indicated that NMO is more common in a Caucasian population...

  3. Hacia una definición de fibra alimentaria

    OpenAIRE

    García Ochoa, Omar Eduardo; Infante, Ramón Benito; Rivera, Carlos Julio

    2008-01-01

    La fibra alimentaria (FA) ha sido un tópico de considerable interés para los nutricionistas y médicos en estos últimos 35 años. Este artículo presenta un análisis sobre la definición de fibra alimentaria y la controversia que existe al respecto, así como las nuevas propuestas que han surgido para incluir en su definición. La FA fue definida como: todos los polisacáridos no almidones más la lignina, que no pueden ser digeridos o absorbidos en el intestino delgado humano. Esta definición no inc...

  4. Desarrollo de materiales compuestos tipo Cermet de matriz Fe

    Directory of Open Access Journals (Sweden)

    Gordo, E.

    2004-04-01

    Full Text Available The objective of this study aims to the development of Fe-matrix composites with high carbide content to achieve properties between high-speed steels (HSS and cemented carbides. Cemented carbides are harder and show higher wear resistance than HSS, but lower toughness. Besides, the substitution of Co or Ni for other binders is desirable due to the carcinogen character of these metals. In this work, a material constituted by an iron matrix and a 50 % wt of WC and TaC carbides is developed. Highenergy milling has been used to obtain composite powders presenting a good bonding and homogeneous distribution of the carbides in the matrix. Those powders were characterised and compacted by die pressing. The green compacts were sintered at different temperatures, and properties like hardness and density were determined. Also, the wear behaviour was studied and microstructural analysis by SEM was carried out to complete the study.

    El objetivo de este trabajo es el desarrollo de materiales compuestos de matriz Fe con alto contenido en carburos con propiedades entre los aceros rápidos y los carburos cementados, ya que estos últimos son más duros y presentan mayor resistencia al desgaste que los primeros pero también menor tenacidad. Además, se hace deseable la sustitución de Co o Ni por otros aglomerantes debido a los riesgos medioambientales y para la salud que estos metales representan. En este trabajo se estudia la obtención de un material formado por una matriz de acero con adición de 50 % en masa de carburos de wolframio (WC y tantalio (TaC. Para ello se han utilizado técnicas de molienda de alta energía que permiten obtener un polvo compuesto con una buena unión metal-cerámica y una distribución homogénea de carburos en la matriz. Después de la caracterización del polvo compuesto se compactaron probetas en matriz uniaxial con objeto de estudiar la sinterabilidad del material. Los compactos fueron sinterizados en vacío a

  5. Neuromyelitis optica and neuromyelitis optica spectrum disorder: Natural history and long-term outcome, an Indian experience

    Directory of Open Access Journals (Sweden)

    Sujit Abajirao Jagtap

    2015-01-01

    Full Text Available Background: Neuromyelitis optica (NMO has evolved from devic′s classical description to a broader disease spectrum, from monophasic illness to a polyphasic illness with multiple recurrences, disease confined to optic nerve and spinal cord to now brain stem, cerebrum and even endocrinopathy due to hypothalamic involvement. Objectives: To report, the epidemiological characteristics, clinical presentations, recurrence rate, treatment and response to therapy in 26 patients with NMO and NMO spectrum disorder among the Indian population. Methods: We performed observational, retrospective analysis of our prospectively maintained data base of patients with NMO, longitudinally extensive transverse myelitis during the period of January 2003-December 2012 who satisfied the national multiple sclerosis society (NMSS task force criteria for diagnosis of NMO and NMO spectrum disorder. Results: There were 26 patients (female: male, 21:5, the mean age of onset of symptom was 27 years (range 9-58, standard deviation = 12. Twenty-one patients (80% fulfilled NMSS criteria for NMO while rest 5 patients (20% were considered as NMO spectrum disorder. Seven patients (27% had a monophasic illness, 19 patients (73% had a polyphasic illness with recurrences. The Median recurrence rate was 4/patient in the polyphasic group. 13 (50% patient were tested for aquaporin 4 antibody, 8 (61% were positive while 5 patients (39% were negative. All patients received intravenous methyl prednisolone, 9 patients (35% required further treatment for acute illness in view of unresponsiveness to steroids. Thirteen patients (50% received disease-modifying agents for recurrences. Mean duration of follow-up was 5 years. All patients had a good outcome (modified Rankin scale, <3 except one who had poor visual recovery. Conclusion: Neuromyelitis optica/NMO spectrum disorder is demyelinating disorder with female predominance, polyphasic course, myelitis being most common event although brain

  6. Neuromyelitis optica with linear enhancement of corpus callosum in brain magnetic resonance imaging with contrast: a case report.

    Science.gov (United States)

    Sahraian, Mohammad Ali; Moghadasi, Abdorreza Naser; Owji, Mahsa; Naghshineh, Hoda; Minagar, Alireza

    2015-06-10

    Neuromyelitis optica is a demyelinating disease of the central nervous system with various patterns of brain lesions. Corpus callosum may be involved in both multiple sclerosis and neuromyelitis optica. Previous case reports have demonstrated that callosal lesions in neuromyelitis optica are usually large and edematous and have a heterogeneous intensity showing a "marbled pattern" in the acute phase. Their size and intensity may reduce with time or disappear in the chronic stages. In this report, we describe a case of a 25-year-old Caucasian man with neuromyelitis optica who presented clinically with optic neuritis and myelitis. His brain magnetic resonance imaging demonstrated linear enhancement of the corpus callosum. Brain images with contrast agent added also showed linear ependymal layer enhancement of the lateral ventricles, which has been reported in this disease previously. Linear enhancement of corpus callosum in magnetic resonance imaging with contrast agent could help in diagnosing neuromyelitis optica and differentiating it from other demyelinating disease, especially multiple sclerosis.

  7. Individualized rituximab treatment for relapsing neuromyelitis optica: a pediatric case report.

    Science.gov (United States)

    He, Dian; Yu, YunLi; Yan, WeiBo; Dai, QingQing; Xu, Zhu; Chu, Lan

    2014-08-01

    Neuromyelitis optica is an autoimmune inflammatory disorder of the central nervous system. Current therapeutic approaches are based on small uncontrolled trials, case series, or case reports. There are only a few case reports describing rituximab for pediatric neuromyelitis optica. A 7-year-old girl with neuromyelitis optica had high disease activity with recurrent myelitis and steroid dependence. A remarkable increase of CD19(+) B-cell count in the peripheral blood mononuclear cells and seropositivity for anti-aquaporin 4 antibody were detected at each attack. After induction therapy with rituximab, the CD19(+) B-cell number was significantly reduced and sustained at low levels. The level of serum anti-aquaporin 4 antibody normalized. She was relapse-free over 1-year follow-up period. An individualized maintenance therapy scheme is underway. Treatment with rituximab for relapsing neuromyelitis optica requires an individualized regimen to optimize the frequency and dosage of administration to maximize efficacy yet minimize overtreatment and cost. Personal levels of CD19(+) B cells in peripheral blood mononuclear cells at previous attacks and responsiveness to rituximab in induction therapy may be two useful indicators in establishing individualized maintenance therapy schemes for relapsing neuromyelitis optica. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Transverse myelitis associated with an itchy rash and hyperckemia: neuromyelitis optica associated with dermatitis herpetiformis.

    Science.gov (United States)

    Iyer, Anand; Rathnasabapathi, Devipriya; Elsone, Liene; Mutch, Kerry; Terlizzo, Monica; Footitt, David; Jacob, Anu

    2014-05-01

    Neuromyelitis optica is associated with severe neurodisability if not recognized and treated promptly. Several autoimmune disorders are associated with this condition and may vary in their presentation. It is essential that clinicians are aware of the uncommon presenting features of neuromyelitis optica and associated autoimmune conditions. A 53-year-old woman presented with nausea and vomiting and was noted to have an asymptomatic elevated creatinine kinase level, which improved with conservative management. She had a history of iron-deficiency anemia due to long-standing celiac disease that was managed with a gluten-free diet. She then presented with recurrent transverse myelitis and a vesicobullous rash over her arms and feet that was pruritic and excoriating. Skin biopsy results confirmed a clinical diagnosis of dermatitis herpetiformis and antibody test findings against aquaporin-4 were positive, leading to a diagnosis of neuromyelitis optica spectrum disorder. She was treated with methylprednisolone sodium succinate, plasma exchange, and azathioprine and has remained in remission. This report highlights the association of neuromyelitis optica with dermatitis herpetiformis, which can present even without clinical features of celiac disease. Nausea, vomiting, and asymptomatic hyperCKemia should be recognized as rare presenting features of neuromyelitis optica.

  9. Comportamiento en fluencia de un material compuesto de matriz metálica Al6061-15 vol % SiCw pulvimetalúrgico

    Directory of Open Access Journals (Sweden)

    González-Doncel, G.

    2005-12-01

    Full Text Available The creep behavior of a powder metallurgy (PM Al6061-15 vol % SiCw metal matrix composite has been studied. This behavior has been compared to that of 6061Al cast alloy and 6061Al PM alloy. The creep response of the PM unreinforced alloy is better than that of the cast 6061Al alloy. Similarly, the behavior of the composite is better than that of the PM unreinforced alloy. Two microstructural factors have been considered the responsible ones of this improvement. The first one is the dispersion of Al2O3 oxide particles of nanometric scale. The second one, is the presence of the SiC whisker reinforcement of micrometric scale. Despite the similar strengthening effect, the intrinsic nature of the reinforcing mechanism is, however, different for each type of particle due to the different microstructural scale.Se ha realizado un estudio de las propiedades en fluencia del material compuesto pulvimetalúrgico Al6061-15 vol % SiCw. Su comportamiento se ha comparado con el de la aleación Al6061 pulvimetalúrgica y la aleación Al6061 de colada. El comportamiento del material pulvimetalúrgico sin reforzar mejora respecto al del material de colada. Al mismo tiempo, el del material compuesto mejora respecto al comportamiento del material pulvimetalúrgico sin reforzar. Se consideran dos factores microestructurales como los principales responsables de la mejora de las propiedades en fluencia de este material compuesto. Por un lado, las partículas de Al2O3 de tamaño nanométrico y, por otro, las partículas de fibra corta cerámicas de SiC de tamaño micrométrico. Aunque ambos tipos de partículas dan lugar a un efecto de refuerzo similar, los mecanismos intrínsecos asociados a la presencia de estas partículas tienen una naturaleza diferente debido a la diferencia en la escala microestructural.

  10. Comportamiento mecánico y estudio in situ de la evolución del daño en el grafito y en un compuesto C/C a 77 y a 300 K

    Directory of Open Access Journals (Sweden)

    Salazar, A.

    2002-04-01

    Full Text Available The mechanical properties at 77 K and at 300 K were determined in two polycristalline graphites with different microstructures and in a C/C composite. The flexure strength and the fracture toughness were evaluated and the micromechanic failure was studied in situ with a long distance microscope. The results obtained showed that the mechanical properties of these carbon materials are not affected by the cryogenic temperatures. The porosity is the main responsible of the mechanical failure in the graphites while in the composite, the matrix/yarn interface deflect the crack nucleated in the mattrix, presenting the best mechanical behavior.

    En este trabajo se han evaluado las propiedades mecánicas a 77 y a 300 K de dos grafitos policristalinos con microestructuras muy diferentes y de un compuesto C/C. Se realizaron ensayos de flexión en tres puntos y de tenacidad, y en éstos últimos se midió in situ la iniciación y la evolución del daño en el fondo de la entalla con un microscopio de larga distancia focal. Los resultados obtenidos muestran que las temperaturas criogénicas no afectan el comportamiento mecánico de los compuestos de carbono estudiados. Además, la porosidad presente en los grafitos es el mecanismo de rotura dominante mientras que en el material compuesto, la intercara débil entre matriz y haz de fibras detiene y desvía las grietas nucleadas en la matriz, presentando el mejor comportamiento mecánico.

  11. Suspected bacterial meningomyelitis: The first presenting clinical feature of neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Li, Xiang; Lin, Jie; Pan, Sipei; Weng, Yiyun; Li, Jia; Zhang, Xu; Xia, Junhui; Tong, Qiaowen

    2017-08-15

    A rare case of neuromyelitis optica spectrum disorder, suspected to be bacterial meningomyelitis as the initial manifestation, is reported. The patient presented with initial symptoms of meningomyelitis and fever. Cerebrospinal fluid analysis revealed pleocytosis (1280×10 6 /L [98% lymphocytes]) and glucose level of 1.8mmol/L. Magnetic resonance imaging revealed >3 vertebral, longitudinally extensive transverse myelitis and area postrema lesions. Right optic neuritis was experienced 20months after the first attack. Serum anti-aquaporin-4 antibody was positive, and a diagnosis of neuromyelitis optica spectrum disorder was made, supporting the hypothesis that the pathogenesis of neuromyelitis optica is triggered by infection. Copyright © 2017. Published by Elsevier B.V.

  12. Imaging Differences between Neuromyelitis Optica Spectrum Disorders and Multiple Sclerosis: A Multi-Institutional Study in Japan.

    Science.gov (United States)

    Tatekawa, H; Sakamoto, S; Hori, M; Kaichi, Y; Kunimatsu, A; Akazawa, K; Miyasaka, T; Oba, H; Okubo, T; Hasuo, K; Yamada, K; Taoka, T; Doishita, S; Shimono, T; Miki, Y

    2018-05-03

    Both clinical and imaging criteria must be met to diagnose neuromyelitis optica spectrum disorders and multiple sclerosis. However, neuromyelitis optica spectrum disorders are often misdiagnosed as MS because of an overlap in MR imaging features. The purpose of this study was to confirm imaging differences between neuromyelitis optica spectrum disorders and MS with visually detailed quantitative analyses of large-sample data. We retrospectively examined 89 consecutive patients with neuromyelitis optica spectrum disorders (median age, 51 years; range, 16-85 years; females, 77; aquaporin 4 immunoglobulin G-positive, 93%) and 89 with MS (median age, 36 years; range, 18-67 years; females, 68; relapsing-remitting MS, 89%; primary-progressive MS, 7%; secondary-progressive MS, 2%) from 9 institutions across Japan (April 2008 to December 2012). Two neuroradiologists visually evaluated the number, location, and size of all lesions using the Mann-Whitney U test or the Fisher exact test. We enrolled 79 patients with neuromyelitis optica spectrum disorders and 87 with MS for brain analysis, 57 with neuromyelitis optica spectrum disorders and 55 with MS for spinal cord analysis, and 42 with neuromyelitis optica spectrum disorders and 14 with MS for optic nerve analysis. We identified 911 brain lesions in neuromyelitis optica spectrum disorders, 1659 brain lesions in MS, 86 spinal cord lesions in neuromyelitis optica spectrum disorders, and 102 spinal cord lesions in MS. The frequencies of periventricular white matter and deep white matter lesions were 17% and 68% in neuromyelitis optica spectrum disorders versus 41% and 42% in MS, respectively (location of brain lesions, P optica spectrum disorders (cervical versus thoracic, 29% versus 71%), whereas they were equally distributed in MS (46% versus 54%). Furthermore, thoracic lesions were significantly longer than cervical lesions in neuromyelitis optica spectrum disorders ( P = .001), but not in MS ( P = .80). Visually detailed

  13. Movement disorders in multiple sclerosis and neuromyelitis optica: A clinical marker of neurological disability.

    Science.gov (United States)

    Candeias da Silva, Carolina; Bichuetti, Denis Bernardi; Azevedo Silva, Sonia Maria Cesar de; Ferraz, Henrique Ballalai; Oliveira, Enedina Maria Lobato de; Borges, Vanderci

    2018-03-03

    Movement disorders are not rare in demyelinating diseases but there are few studies comparing their frequency between multiple sclerosis and neuromyelitis optica spectrum disorder. Our aim was to determine the frequency and the related features of movement disorders in a cohort of patients with multiple sclerosis and neuromyelitis optica spectrum disorder. It is a cross-sectional study of patients with multiple sclerosis and neuromyelitis optica spectrum disorder. Patients were evaluated by a movement disorder specialist. Data from a personal interview and neurological examination were collected. Fahn-Tolosa-Marin tremor rating scale was used for tremor evaluation. Health-related quality of life was assessed using EuroQol instrument. Two hundred fifty-three patients were included (mean [SD] age, 40 [12] years; 74.3% female; median [IQR] EDSS score 2.5 [1.0-6.0]); 26% presented with movement disorders. Paroxysmal dystonia (n = 32) and tremor (n = 27) were the most common movement disorders. Patients with multiple sclerosis and low Expanded Disability Status Scale score (below 4.0) have fewer movement disorders than patients with neuromyelitis optica spectrum disorder. The diagnosis of neuromyelitis optica spectrum disorder was strongly associated with paroxysmal dystonia (OR = 22.07, 95% CI = 2.56-189.78; p = 0.005). Patients with multiple sclerosis and patients without movement disorders have a slightly better quality of life. Paroxysmal dystonia was the most common movement disorder in demyelinating diseases and strongly associated with neuromyelitis optica spectrum disorder. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Neuromyelitis optica, atypical hemophagocytic lymphohistiocytosis and heterozygous perforin A91V mutation.

    Science.gov (United States)

    Palterer, Boaz; Brugnolo, Francesca; Sieni, Elena; Barilaro, Alessandro; Parronchi, Paola

    2017-10-15

    Neuromyelitis optica is an autoimmune demyelinating inflammatory disease characterized by optic neuritis and myelitis with anti-aquaporin 4 antibodies. Hemophagocytic lymphohistiocytosis is a severe systemic inflammatory syndrome that can present in a genetic primary form or secondarily to infective, neoplastic or autoimmune diseases. Our case discusses the first reported case of atypical late-onset hemophagocytic lymphohistiocytosis in a patient with neuromyelitis optica, with multiple triggering factors and carrying the common A91V hypomorphic perforin mutation, that blurs the distinction between primary and secondary forms. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Idiopathic Transverse Myelitis and Neuromyelitis Optica: Clinical Profiles, Pathophysiology and Therapeutic Choices

    Science.gov (United States)

    Awad, Amer; Stüve, Olaf

    2011-01-01

    Transverse myelitis is a focal inflammatory disorder of the spinal cord which may arise due to different etiologies. Transverse myelitis may be idiopathic or related/secondary to other diseases including infections, connective tissue disorders and other autoimmune diseases. It may be also associated with optic neuritis (neuromyelitis optica), which may precede transverse myelitis. In this manuscript we review the pathophysiology of different types of transverse myelitis and neuromyelitis optica and discuss diagnostic criteria for idiopathic transverse myelitis and risk of development of multiple sclerosis after an episode of transverse myelitis. We also discuss treatment options including corticosteroids, immunosuppressives and monoclonal antibodies, plasma exchange and intravenous immunoglobulins. PMID:22379456

  16. Neuromyelitis optica (NMO) - an autoimmune disease of the central nervous system (CNS)

    DEFF Research Database (Denmark)

    Asgari, N; Owens, T; Frøkiaer, J

    2010-01-01

    Asgari N, Owens T, Frøkiaer J, Stenager E, Lillevang ST, Kyvik KO. Neuromyelitis optica (NMO) - an autoimmune disease of the central nervous system (CNS).
Acta Neurol Scand: DOI: 10.1111/j.1600-0404.2010.01416.x.
© 2010 John Wiley & Sons A/S. In the past 10 years, neuromyelitis optica (NMO) has...... or by intrathecal administration to naive mice. NMO may be characterized as a channelopathy of the central nervous system with autoimmune characteristics....

  17. Fibras nervosas retinianas mielinizadas associadas a miopia e ambliopia

    OpenAIRE

    Borges, Bárbara; Cabugueira, Ana; Anjos, Rita; Paixão, Ana; Marques, Margarida; Toscano, Alcina

    2015-01-01

    Introdução: A presença de fibras nervosas mielinizadas na retina está descrita em cerca de 1% da população. Os doentes são habitualmente assintomáticos, embora possam coexistir outras alterações oculares como miopia e ambliopia. Material e Métodos: Descrevem-se 3 casos de crianças com fobras nervosas retinianas mielinizadas unilaterais, associadas a miopia e ambliopia. Resultados: A idade das crianças variou entre 1 e 7 anos. O olho afectado foi o olho direito. A melhor acuidade visual ...

  18. Challenges and opportunities in designing clinical trials for neuromyelitis optica

    Science.gov (United States)

    Barron, Gerard; Behne, Jacinta M.; Bennett, Jeffery L.; Chin, Peter S.; Cree, Bruce A.C.; de Seze, Jerome; Flor, Armando; Fujihara, Kazuo; Greenberg, Benjamin; Higashi, Sayumi; Holt, William; Khan, Omar; Knappertz, Volker; Levy, Michael; Melia, Angela T.; Palace, Jacqueline; Smith, Terry J.; Sormani, Maria Pia; Van Herle, Katja; VanMeter, Susan; Villoslada, Pablo; Walton, Marc K.; Wasiewski, Warren; Wingerchuk, Dean M.; Yeaman, Michael R.

    2015-01-01

    Current management of neuromyelitis optica (NMO) is noncurative and only partially effective. Immunosuppressive or immunomodulatory agents are the mainstays of maintenance treatment. Safer, better-tolerated, and proven effective treatments are needed. The perceived rarity of NMO has impeded clinical trials for this disease. However, a diagnostic biomarker and recognition of a wider spectrum of NMO presentations has expanded the patient population from which study candidates might be recruited. Emerging insights into the pathogenesis of NMO have provided rationale for exploring new therapeutic targets. Academic, pharmaceutical, and regulatory communities are increasingly interested in meeting the unmet needs of patients with NMO. Clinical trials powered to yield unambiguous outcomes and designed to facilitate rapid evaluation of an expanding pipeline of experimental agents are needed. NMO-related disability occurs incrementally as a result of attacks; thus, limiting attack frequency and severity are critical treatment goals. Yet, the severity of NMO and perception that currently available agents are effective pose challenges to study design. We propose strategies for NMO clinical trials to evaluate agents targeting recovery from acute attacks and prevention of relapses, the 2 primary goals of NMO treatment. Aligning the interests of all stakeholders is an essential step to this end. PMID:25841026

  19. International consensus diagnostic criteria for neuromyelitis optica spectrum disorders

    Science.gov (United States)

    Banwell, Brenda; Bennett, Jeffrey L.; Cabre, Philippe; Carroll, William; Chitnis, Tanuja; de Seze, Jérôme; Fujihara, Kazuo; Greenberg, Benjamin; Jacob, Anu; Jarius, Sven; Lana-Peixoto, Marco; Levy, Michael; Simon, Jack H.; Tenembaum, Silvia; Traboulsee, Anthony L.; Waters, Patrick; Wellik, Kay E.

    2015-01-01

    Neuromyelitis optica (NMO) is an inflammatory CNS syndrome distinct from multiple sclerosis (MS) that is associated with serum aquaporin-4 immunoglobulin G antibodies (AQP4-IgG). Prior NMO diagnostic criteria required optic nerve and spinal cord involvement but more restricted or more extensive CNS involvement may occur. The International Panel for NMO Diagnosis (IPND) was convened to develop revised diagnostic criteria using systematic literature reviews and electronic surveys to facilitate consensus. The new nomenclature defines the unifying term NMO spectrum disorders (NMOSD), which is stratified further by serologic testing (NMOSD with or without AQP4-IgG). The core clinical characteristics required for patients with NMOSD with AQP4-IgG include clinical syndromes or MRI findings related to optic nerve, spinal cord, area postrema, other brainstem, diencephalic, or cerebral presentations. More stringent clinical criteria, with additional neuroimaging findings, are required for diagnosis of NMOSD without AQP4-IgG or when serologic testing is unavailable. The IPND also proposed validation strategies and achieved consensus on pediatric NMOSD diagnosis and the concepts of monophasic NMOSD and opticospinal MS. PMID:26092914

  20. Widespread cortical thinning in patients with neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Kim, S-H; Kwak, K; Hyun, J-W; Jeong, I H; Jo, H-J; Joung, A; Kim, J-H; Lee, S H; Yun, S; Joo, J; Lee, J-M; Kim, H J

    2016-07-01

    Studies on cortical involvement and its relationship with cognitive function in patients with neuromyelitis optica spectrum disorder (NMOSD) remain scarce. The objective of this study was to compare cortical thickness on magnetic resonance imaging (MRI) between patients with NMOSD and multiple sclerosis (MS) and to investigate its relationship with clinical features and cognitive function. This observational clinical imaging study of 91 patients with NMOSD, 52 patients with MS and 44 healthy controls was conducted from 1 December 2013 to 30 April 2015 at the institutional referral center. Three tesla MRI of the brain and neuropsychological tests were performed. Cortical thickness was measured using three-dimensional surface-based analysis. Both sets of patients exhibited cortical thinning throughout the entire brain cortex. Patients with MS showed a significantly greater reduction in cortical thickness over broad regions of the bilateral frontal and parieto-temporal cortices and the left precuneus compared to those with NMOSD. Memory functions in patients with MS were correlated with broad regional cortical thinning, whereas no significant associations were observed between cortical thickness and cognitive function in patients with NMOSD. Widespread cortical thinning was observed in patients with NMOSD and MS, but the extent of cortical thinning was greater in patients with MS. The more severe cortical atrophy may contribute to memory impairment in patients with MS but not in those with NMOSD. These results provide in vivo evidence that the severity and clinical relevance of cortical thinning differ between NMOSD and MS. © 2016 EAN.

  1. Is pruritus an indicator of aquaporin-positive neuromyelitis optica?

    Science.gov (United States)

    Netravathi, Manjunath; Saini, Jitender; Mahadevan, Anita; Hari-Krishna, Bollampalli; Yadav, Ravi; Pal, Pramod Kumar; Satishchandra, Parthasarathy

    2017-05-01

    Recently, pruritus has been recognised as an important association with neuromyelitis optica spectrum disorders (NMOSD). To determine the clinical and radiological characteristics of patients with NMOSD and pruritus. Among 57 consecutive patients with NMOSD, 15 (26.3% women) reported pruritus. All had aquaporin-4 (AQP4) antibodies. The mean age was 34.5 ± 9.1 years, age at onset was 31.3 ± 11.0 years and the duration of illness was 3.9 ± 3.1 years. Pruritus preceded the neurological disturbances in all the patients. Predominant patients experienced pruritus in the cervical dermatome (66.7%) followed by cervicothoracic region (13.3%), trigeminal nerve (13.3%) and lumbar region (6.7%). Lesions extending from cervicomedullary junction up to the thoracic segment was the most common site of affection (40%) followed by cervicothoracic (26.7%), cervicomedullary junction to cervical cord (13.3%), cervical cord (6.7%) and thoracic segment (6.7%). This report is one of the largest series reporting the close association of pruritus with onset of neurological symptoms in NMOSD. It highlights the importance of recognising this rare symptom which may help in making a correct diagnosis in a patient with suspected demyelinating disorder. In a patient with NMOSD, early treatment with immunomodulation during pruritus may prevent or minimise occurrence of neurological dysfunction.

  2. Plasma Exchange in Severe Attacks of Neuromyelitis Optica

    Directory of Open Access Journals (Sweden)

    Mickael Bonnan

    2012-01-01

    Full Text Available Background. Neuromyelitis optica (NMO attacks are poorly controlled by steroids and evolve in stepwise neurological impairments. Assuming the strong humoral response underlying NMO attacks, plasma exchange (PLEX is an appropriate technique in severe NMO attacks. Objective. Presenting an up-to-date review of the literature of PLEX in NMO. Methods. We summarize the rationale of PLEX in relation with the physiology of NMO, the main technical aspects, and the available studies. Results. PLEX in severe attacks from myelitis or optic neuritis are associated with a better outcome, depending on PLEX delay (“time is cord and eyes”. NMO-IgG status has no influence. Finally, we build up an original concept linking the inner dynamic of the lesion, the timing of PLEX onset and the expected clinical results. Conclusion. PLEX is a safe and efficient add-on therapy in NMO, in synergy with steroids. Large therapeutic trials are required to definitely assess the procedure and define the time opportunity window.

  3. NMO-IgG: A Specific Biomarker for Neuromyelitis Optica

    Directory of Open Access Journals (Sweden)

    Brian G. Weinshenker

    2006-01-01

    Full Text Available Neuromyelitis optica (NMO is an inflammatory demyelinating disease that principally targets the optic nerves and spinal cord and often leads to severe disability and occasionally life threatening respiratory failure. Although its clinical manifestations overlap with those of multiple sclerosis (MS, in established cases these two conditions can be distinguished on the basis of clinical, radiological, and routine spinal fluid studies. The diagnosis in early cases or limited forms of NMO is difficult. We recently discovered a unique IgG autoantibody (NMO-IgG that is highly specific to patients with NMO and thus a valuable diagnostic aid. Its antigen, aquaporin-4 (AQP4, is the central nervous system’s predominant water channel protein. This antibody has not yet been proven to be pathogenic, but several facts suggest that it might be, including the similarity of the immunohistochemical pattern of NMO-(AQP4 IgG binding to mouse CNS tissues to the pattern of immune complex deposition in autopsied patients’ spinal cord tissue. The spectrum of diseases identified by NMO-IgG is broader than has previously been recognized clinically and includes incomplete forms of NMO, such as recurrent transverse myelitis without optic neuritis and recurrent optic neuritis without myelitis.

  4. Seronegative Neuromyelitis Optica: A Case Report of a Hispanic Male

    Directory of Open Access Journals (Sweden)

    Nabeel Badri

    2016-05-01

    Full Text Available Neuromyelitis optica (NMO is a rare disease, common in white females and rarely reported in Hispanic males. It is usually associated with recurrent demyelinating spectrum that is autoimmune in nature. The diagnosis is usually confirmed by antibody biomarkers; however, they can be negative and lead to more dilemma in diagnosis. Furthermore, the course of disease and prognosis are different in seronegative as compared to seropositive NMO. Treatment is similar in both subgroups with new approaches under investigation for seronegative NMO patients. We present an interesting case of a 37-year-old Hispanic male who presented with sudden onset of lower extremity weakness, numbness, blurry vision, and urinary retention. Magnetic resonance imaging (MRI of the thoracic spine showed multiphasic demyelinating process involving the thoracic spinal cord. His brain MRI also revealed changes suggesting optic neuritis. The patient met the criteria for diagnosis of NMO by having optic neuritis and myelitis by imaging studies despite having negative aquaporin-4 antibodies (AQP4-Ab. His condition improved after plasma exchange. NMO can be difficult to distinguish from acute multiple sclerosis in the early stages of the disease. Having AQP4-Ab testing is important for diagnosis with imaging studies; however, negative antibody results cannot exclude the diagnosis, but rather group it in seronegative subtype. Ongoing studies and research suggest that seronegative NMO might have a different pathophysiology, manifestation, and prognosis.

  5. Treatment of neuromyelitis optica: an evidence based review

    Directory of Open Access Journals (Sweden)

    Douglas Sato

    2012-01-01

    Full Text Available Neuromyelitis optica (NMO is an inflammatory disease of the central nervous system characterized by severe optic neuritis and transverse myelitis, usually with a relapsing course. Aquaporin-4 antibody is positive in a high percentage of NMO patients and it is directed against this water channel richly expressed on foot processes of astrocytes. Due to the severity of NMO attacks and the high risk for disability, treatment should be instituted as soon as the diagnosis is confirmed. There is increasing evidence that NMO patients respond differently from patients with multiple sclerosis (MS, and, therefore, treatments for MS may not be suitable for NMO. Acute NMO attacks usually are treated with high dose intravenous corticosteroid pulse and plasmapheresis. Maintenance therapy is also required to avoid further attacks and it is based on low-dose oral corticosteroids and non-specific immunosuppressant drugs, like azathioprine and mycophenolate mofetil. New therapy strategies using monoclonal antibodies like rituximab have been tested in NMO, with positive results in open label studies. However, there is no controlled randomized trial to confirm the safety and efficacy for the drugs currently used in NMO.

  6. Autoimmune AQP4 channelopathies and neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Hinson, Shannon R; Lennon, Vanda A; Pittock, Sean J

    2016-01-01

    Neuromyelitis optica (NMO) spectrum disorders (SD) represent an evolving group of central nervous system (CNS)-inflammatory autoimmune demyelinating diseases unified by a pathogenic autoantibody specific for the aquaporin-4 (AQP4) water channel. It was historically misdiagnosed as multiple sclerosis (MS), which lacks a distinguishing biomarker. The discovery of AQP4-IgG moved the focus of CNS demyelinating disease research from emphasis on the oligodendrocyte and myelin to the astrocyte. NMO is recognized today as a relapsing disease, extending beyond the optic nerves and spinal cord to include brain (especially in children) and skeletal muscle. Brain magnetic resonance imaging abnormalities, identifiable in 60% of patients at the second attack, are consistent with MS in 10% of cases. NMOSD-typical lesions (another 10%) occur in AQP4-enriched regions: circumventricular organs (causing intractable nausea and vomiting) and the diencephalon (causing sleep disorders, endocrinopathies, and syndrome of inappropriate antidiuresis). Advances in understanding the immunobiology of AQP4 autoimmunity have necessitated continuing revision of NMOSD clinical diagnostic criteria. Assays that selectively detect pathogenic AQP4-IgG targeting extracellular epitopes of AQP4 are promising prognostically. When referring to AQP4 autoimmunity, we suggest substituting the term "autoimmune aquaporin-4 channelopathy" for the term "NMO spectrum disorders." Randomized clinical trials are currently assessing the efficacy and safety of newer immunotherapies. Increasing therapeutic options based on understanding the molecular pathogenesis is anticipated to improve the outcome for patients with AQP4 channelopathy. © 2016 Elsevier B.V. All rights reserved.

  7. Ovarian Reserve in Women With Neuromyelitis Optica Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Jan Thöne

    2018-06-01

    Full Text Available Neuromyelitis optica spectrum disorder (NMOSD is a neuroinflammatory disease. The majority of NMOSD patients is seropositive for aquaporin-4 (AQP4 antibodies. AQP4 is the main water channel protein in the central nervous system, but has also been identified in the female reproductive system. Fertility issues and ovarian reserve has not yet been studied in females with NMOSD. The purpose of this study was to measure serum Anti-Müllerian hormone (AMH in females with NMOSD compared to healthy controls (HC, in combination with other lifestyle and reproduction parameters. AMH is independent from the menstrual cycle and a reliable indicator of both ovarian reserve and ovarian function. We included a total of 32 reproductive-age females, 18 HC and 14 with NMOSD. We used an enzymatically amplified two-site immunoassay to determine serum AMH level. In comparison to HC, mean AMH value was reduced in NMOSD. Apart from that significantly more women with NMOSD showed low AMH levels (< 0.8 ng/ml. Low AMH was associated with disease activity. In contrast, none of the immunotherapies for NMOSD, neither any reproductive life style parameter was associated with a decreased AMH. Our results contribute to understanding of hindered fertility in females with NMOSD and enables neurologists to better counsel female patients.

  8. Homogeneización de materiales compuestos de inclusiones elipsoidales periódicas

    Directory of Open Access Journals (Sweden)

    H. Hernández Cabanas

    2015-01-01

    Full Text Available Los materiales compuestos son de vital importancia para el ser humano desde sus primeros tiempos, en la actualidad el empleo de estos materiales ha proliferado en la industria debido a la presencia de propiedades físicas que no están presentes en ninguno de sus componentes. El hecho de conocer previamente las propiedades de los materiales compuestos es unos de los problemas a los que se enfrenta la ciencia. Los métodos de homogeneización se emplean para calcular las propiedades efectivas de materiales compuestos. En el presente trabajo se plantea la formulación del método de homogeneización asintótica para compuestos tridimensionales y la transformación de los problemas locales a partir de las simetrías presentes en un compuesto de inclusiones elipsoidales periódicas. Se formula la resolución de los problemas locales por el método de elementos finitos utilizando elementos tetraédricos de cuatro nodos en la discretización del problema. Se realizan los cálculos numéricos para la obtención de los coeficientes efectivos en un material de inclusiones elipsoidales periódicas de aluminio embebidas en una matriz. La matriz es a su vez un compuesto del mismo aluminio con inclusiones esféricas de carburo de silicio con distribución cuadrada. Se muestran algunos de los resultados obtenidos para este compuesto variando la fracción volumétrica de aluminio para distintas razones de aspecto de las inclusiones elipsoidales. Se observa que en el caso de constituyentes isotrópicos, con una geometría del compuesto que presente una dirección predominante, el material resultante pierde esta propiedad.

  9. Measurement of uranium concentration by molecular absorption spectrophotometry by means optical fibers; Medicion continua de concentracion de uranio por espectrofotometria de absorcion molecular mediante fibras opticas

    Energy Technology Data Exchange (ETDEWEB)

    Gauna, Alberto C.; Pascale, Ariel A. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Centro Atomico Ezeiza. Agencia Minipost

    1996-07-01

    An on-line method for measuring the concentration of uranium in uranyl nitrate-nitric acid aqueous solutions is described. The method is based on molecular absorption spectrophotometry with transmission of light by means of optical fibers. It is ideally suited for control and processes development applications. (author)

  10. Electric grid in Spain: a private network of optical fiber with national coverage; Red electrica de Espana: una red privada de fibra optica con cobertura nacional

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, A.

    1995-12-31

    Red Electrica constructed a grid with optical fiber in 1989 for the grids of 400-220 Kv. In 1995 the length of the grid will be of 6.600 Km. This grid supplies the telecommunication advanced services and contributes in the efficiency and quality of different tasks of Red Electrica.

  11. Thermometer by optical fiber for ampacity studies in overhead transmission lines; Termometro a fibra optica para estudo da ampacidade em linhas de transmissao aereas

    Energy Technology Data Exchange (ETDEWEB)

    Valente, L.C.G.; Kawase, L.R.; Silva Filho, J.I. da; Silva, J.M.M. da [Centro de Pesquisas de Energia Eletrica, Rio de Janeiro, RJ (Brazil); Igarashi, A.Y. [Universidade Federal, Rio de Janeiro, RJ (Brazil)

    1995-12-31

    This article suggests the utilization of thermometers constructed from optical fibers technology in overhead power transmission lines. This will help the studies in progress about the electric power systems ampacity. It also presents the advantages of using optical fibers instead of conventional thermometers. As an example, the fact that the optical fibers are dielectric and make possible the remote monitoring. It is also shown a possibility of introducing such measuring system in electric junctions where OPGW cables are used 4 refs., 4 figs.; e-mail: liliana at fis.puc-rio.br

  12. Optical fiber sensors for image formation in radiodiagnostic - preliminary essays; Sensores a fibra optica para formacao de imagens em radiodiagnostico - ensaios preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Cesar C. de; Werneck, Marcelo M. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Biomedica

    1998-07-01

    This work describes preliminary experiments that will bring subsidies to analyze the capability to implement a system able to capture radiological images with new sensor system, comprised by FOs scanning process and I-CCD camera. These experiments have the main objective to analyze the optical response from FOs bundle, with several typos of scintillators associated with them, when it is submitted to medical x-rays exposition. (author)

  13. Monitoring of pipeline deformations using optical fiber sensors based on Bragg lattices; Monitoracao de deformacoes em dutos utilizando sensores a fibra optica com base em redes de Bragg

    Energy Technology Data Exchange (ETDEWEB)

    Moszkowica, Viktor Nigri [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil)]. E-mail: vnigri@bol.com.br

    2002-06-01

    In the petroleum sector there is a growing need for the use of pipelines as well as for their monitoring. A way to avoid leaks that can cause great damage to the environment is by the monitoring of deformations. In case failures can not be avoided through operational procedures, the monitoring of deformations can identify the initial moment and location of the leak, allowing for quick action on the part of the cleaning and depollution teams. Also important is the monitoring of slopes and soil movements. The same thing applies to production and transfer submarine pipelines subject to complex dynamic loadings that combine internal and external pressure, torsion, axial stress and, the most common of all, flexion loading. For this type of application, optical fiber sensors present a number of interesting features. Multiplexing, remote operation and long distance distribution of sensors are characteristics that attract their use in deformation monitoring systems. Presented herein are the research results of works that had the objective of developing deformation monitoring techniques in pipelines using optical fiber sensors based on Bragg grating. The technical feasibility of this technology is demonstrated through laboratorial tests. Also discussed herein are methods for field implementation of sensors, optical signal multiplexing techniques and potential advantages of applying this technology. (author)

  14. Transmission lines with lightning arresters cables energized by optical fibers; Linhas de transmissao com cabos para-raios energizados com fibra optica

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Fumitaka; Cicarelli, Liliane Dias [Alcoa Aluminio S.A. (Brazil); D`Ajuz, Ary [ELETRONORTE, Belem, PA (Brazil); Martinez, Manuel L.B. [Escola Federal de Engenharia de Itajuba, MG (Brazil); Masuda, Mario [Tecname Engenharia (Brazil)

    1995-12-31

    Recently, the implementation of optical systems has been possible through the utilization of the existent transmission lines structure by the sharing between electric power and telecommunications enterprises, using Op-GW cables instead of conventional lightning-arresters cables. In order to make such optical sharing feasible, the enterprise ALCOA Aluminio S.A is developing the energized lightning-arrester system with optical fiber in it. This work presents such system and show its great advantages specially when implemented in low population density regions in order to supply electric power demand at lower costs 6 refs., 5 figs.

  15. Desarrollo material polimérico reforzado con fibras naturales

    OpenAIRE

    2012-01-01

    El fundamento de los llamados materiales compuestos de la modernidad, son definidos como polímeros sintéticos. Uno de ellos es la baquelita, el cual fue uno de los primeros polímeros totalmente sintéticos. Iniciando de esta creación, es probable en la actualidad, adaptar y generar novedades en los polímeros que pueden llegar a ser producidos para sectores específicos. Por ejemplo se han desarrollado nuevos tipos o clases de polímeros que no presentan defectos a largo plazo por corrosión. Es p...

  16. Serological prevalence of celiac disease in Brazilian population of multiple sclerosis, neuromyelitis optica and myelitis.

    Science.gov (United States)

    de Oliveira, Pérola; de Carvalho, Daniel Rocha; Brandi, Ivar Viana; Pratesi, Riccardo

    2016-09-01

    Comorbidity of celiac disease with demyelinating diseases of the central nervous system has been reported since the 1960s. The objective of this study was to determine the serological prevalence of celiac disease in the largest series of patients diagnosed with multiple sclerosis, neuromyelitis optica, or myelitis. A prevalence study was conducted with patients evaluated at Sarah Network of Rehabilitation Hospitals between March 2012 and September 2013. They were previously diagnosed with multiple sclerosis, neuromyelitis optica, or idiopathic myelitis. The serum levels of antibodies against tissue transglutaminase and endomysium were assessed. Of the 379 patients evaluated, 249 (65.70%) were diagnosed with multiple sclerosis, 37 (9.56%) with neuromyelitis optica, and 96 (24.54%) with idiopathic myelitis. Two patients (0.53%), one with multiple sclerosis and other with myelitis, tested positive for both antibodies. Our study do not confirm the relationship between celiac serological antibodies with multiple sclerosis, neuromyelitis optica and inflammatory myelitis of an unknown etiology. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Diagnosis and management of Neuromyelitis Optica Spectrum Disorder (NMOSD) in Iran

    DEFF Research Database (Denmark)

    Sahraian, Mohammad Ali; Moghadasi, Abdorreza Naser; Azimi, Amir Reza

    2017-01-01

    Neuromyelitis Optica Spectrum Disorder (NMOSD) is a relapsing neuro inflammatory disease of the central nervous system that typically presents with optic neuritis or myelitis and may cause severe disability. The diagnostic criteria have been updated and several immunosuppressive agents have been...

  18. Cognitive Impairment and Whole Brain Diffusion in Patients with Neuromyelitis Optica after Acute Relapse

    Science.gov (United States)

    He, Diane; Wu, Qizhu; Chen, Xiuying; Zhao, Daidi; Gong, Qiyong; Zhou, Hongyu

    2011-01-01

    The objective of this study investigated cognitive impairments and their correlations with fractional anisotropy (FA) and mean diffusivity (MD) in patients with neuromyelitis optica (NMO) without visible lesions on conventional brain MRI during acute relapse. Twenty one patients with NMO and 21 normal control subjects received several cognitive…

  19. Continuous Positive Airway Pressure (CPAP for prevention of recurrent pneumonia in the Neuromyelitis Optica patient

    Directory of Open Access Journals (Sweden)

    James A. Welker

    2014-01-01

    Conclusions: Patients with Neuromyelitis Optica differ from those with traumatic spinal cord injury as they have a chronic progressive systemic illness that causes continued deterioration of their nervous system resulting in the need for routine monitoring that ensures the timely addition of CPAP for the prevention of pneumonia and its associated medical expenses.

  20. Neuromyelitis optica with Hashimoto′s thyroiditis: A new syndrome or just coincidence

    Directory of Open Access Journals (Sweden)

    Abhishek Singhai

    2015-01-01

    Full Text Available Neuromyelitis optica (NMO is an uncommon disease syndrome of the central nervous system that affects the optic nerves and spinal cord. NMO with endocrinopathies has been described as being unique to black Antillean and Afro-Brazilian women. We describe one case of NMO with hashimoto′s thyroiditis in a young female, probably first case report in India.

  1. Neuromyelitis optica spectrum disorders in Algeria: A preliminary study in the region of Tizi Ouzou.

    Science.gov (United States)

    Daoudi, Smail; Bouzar, Melissa

    2016-03-01

    Neuromyelitis optica (NMO) is a disabling inflammatory condition that targets astrocytes in the optic nerves and spinal cord. Recent advances led to the individualization of a set of conditions now referred as NMO spectrum disorder (NMOSD). To describe the prevalence and characteristics of NMO SD in north Algeria. The present study is a retrospective and descriptive work which took place in Nedir Mohamed teaching hospital, Tizi-Ouzou, Algeria. 938 Medical files of patients with CNS inflammatory demyelinating diseases were reviewed then patients with optic neuritis and/or myelitis were preselected. Patients who met the 2015 neuromyelitis optica spectrum disorders criteria were selected and analyzed 08 Patients (3.4%) met the 2015 criteria for neuromyelitis optica spectrum disorders, 3/8 (37.5%) were positive to AQ4-IgG and 5/8 (62.5%) were negative. Mean age of onset was 29 years, female to male ratio was 3:1, cerebral MRI was normal in 75% of cases and longitudinally extensive transverse myelitis was present in 75% of cases. 37/232 Patients (15.9%) were considered at high risk of neuromyelitis optica spectrum disorders The present study suggests that the spectrum of NMO disorders is a rare entity among patients with optic nerve and spinal cord demyelinating lesions in north Algeria. However, the lack of accurate AQ4-IgG test certainly underestimates its real prevalence. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Antibodies against aquaporin-4 in neuromyelitis optica: distinction between recurrent and monophasic patients

    NARCIS (Netherlands)

    Ketelslegers, I.A.; Modderman, P.W.; Vennegoor, A.; Killestein, J.; Hamann, D.; Hintzen, R.Q.

    2011-01-01

    The detection of antibodies against aquaporin-4 (AQP4) has improved the diagnosis of neuromyelitis optica (NMO). We evaluated a recently established cell-based anti-AQP4 assay in 273 patients with inflammatory CNS demyelination. The assay had a specificity of 99% and a sensitivity of 56% to detect

  3. Brain perfusion SPECT analysis : New insights in mild cognitive impairment and neuromyelitis optica

    NARCIS (Netherlands)

    Sánchez Catasùs, Carlos Alfredo

    2018-01-01

    Het doel van dit proefschrift was om aan te tonen dat hersenperfusie SPECT kan helpen bij het verhelderen van belangrijke vragen met betrekking tot het prodromale “Mild Cognitive Impairment” (MCI) stadium van de ziekte van Alzheimer (AD) en recidiverende Neuromyelitis Optica (NMO). Dit is niet

  4. Acquired Demyelinating Syndromes: Focus on Neuromyelitis Optica and childhood-onset Multiple Sclerosis

    NARCIS (Netherlands)

    E.D. van Pelt - Gravesteijn (Daniëlle)

    2016-01-01

    markdownabstractAcquired demyelinating syndromes (ADS) cover a broad spectrum of central nervous system (CNS) inflammatory demyelinating syndromes, of which multiple sclerosis (MS) is the most common subtype. This thesis focuses on two relatively rare clinical subtypes of ADS: neuromyelitis optica

  5. Estudio sobre la inclusión de fibra dietética en productos reestructurados de pescado

    OpenAIRE

    Sánchez Alonso, Isabel

    2009-01-01

    El objetivo principal de esta memoria es el estudio tecnológico de la inclusión de fibra dietética en músculo de pescado picado y geles elaborados a partir de surimi, ambos conservados en estado congelado. Se estudian dos tipos de fibra dietética: A/ fibra de trigo y B/ concentrado de fibra dietética antioxidante obtenido a partir de subproductos de la industria vinícola. Los dos tipos de fibras dietéticas elegidas, presentan propiedades muy diferentes en sus diversos aspectos funcional-tecno...

  6. Neuromyelitis optica: association with paroxysmal painful tonic spasms.

    Science.gov (United States)

    Carnero Contentti, E; Leguizamón, F; Hryb, J P; Celso, J; Pace, J L Di; Ferrari, J; Knorre, E; Perassolo, M B

    2016-10-01

    Paroxysmal painful tonic spasms (PPTS) were initially described in multiple sclerosis (MS) but they are more frequent in neuromyelitis optica (NMO). The objective is to report their presence in a series of cases of NMO and NMO spectrum disorders (NMOSD), as well as to determine their frequency and clinical features. We conducted a retrospective assessment of medical histories of NMO/NMOSD patients treated in 2 hospitals in Buenos Aires (Hospital Durand and Hospital Álvarez) between 2009 and 2013. Out of 15 patients with NMOSD (7 with definite NMO and 8 with limited NMO), 4 presented PPTS (26.66%). PPTS frequency in the definite NMO group was 57.14% (4/7). Of the 9 patients with longitudinally extensive transverse myelitis (LETM), 44.44% (9/15) presented PPTS. Mean age was 35 years (range, 22-38 years) and all patients were women. Mean time between NMO diagnosis and PPTS onset was 7 months (range, 1-29 months) and mean time from last relapse of LETM was 30 days (range 23-40 days). LETM (75% cervicothoracic and 25% thoracic) was observed by magnetic resonance imaging (MRI) in all patients. Control over spasms and pain was achieved in all patients with carbamazepine (associated with gabapentin in one case). No favourable responses to pregabalin, gabapentin, or phenytoin were reported. PPTS are frequent in NMO. Mean time of PPTS onset is approximately one month after an LETM relapse, with extensive cervicothoracic lesions appearing on the MRI scan. They show an excellent response to carbamazepine but little or no response to pregabalin and gabapentin. Prospective studies with larger numbers of patients are necessary in order to confirm these results. Copyright © 2014 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Diagnosis of neuromyelitis optica (NMO) spectrum disorders: is MRI obsolete?

    Energy Technology Data Exchange (ETDEWEB)

    Downer, Jonathan James; Carter, Ranjana; Kueker, Wilhelm; Quaghebeur, Gerardine [John Radcliffe Hospital, Department of Neuroradiology, Oxford (United Kingdom); Leite, Maria Isabel; Palace, Jacqueline [Oxford University, Department of Clinical Neurology, Oxford (United Kingdom)

    2012-04-15

    Neuromyelitis optica (NMO) is a severe demyelinating disease that preferentially involves spinal cord and optic nerve. It is part of a spectrum of neurological conditions associated with antibodies to aquaporin-4 (AQP4). This study investigates the role of MRI where novel, more sensitive AQP4 antibody immunoassay techniques are being used. Retrospective review of neuroimaging in 69 patients (25 antibody positive, 44 antibody negative), investigated in the context of suspected NMO or NMO spectrum disorder, was performed independently by two consultant neuroradiologists. Longitudinally extensive, central spinal cord lesions were more frequent in AQP4 positive patients (95.2% vs 35.5%, p < 0.0001; 85.7% vs 45.2%, p = 0.015). Multiple sclerosis diagnostic criteria were less frequently fulfilled on brain MRI in antibody positive patients (5.6% vs 33.3%, p = 0.035). Juxtacortical and corpus callosal lesions were also less common in this group (16.7% vs 46.7%, p = 0.063; 5.6% vs 46.7%, p = 0.0034). Hypothalamic and periependymal disease related to the aqueduct was not seen in antibody negative patients. T1 hypointensity was more common in cord lesions of antibody positive patients (75.0% vs 35.3%, p = 0.037). However, this characteristic did not discriminate antibody positive and negative longitudinally extensive cord lesions (73.3% vs 62.5%, p = 0.66). The NMO spectrum of diseases are among an increasing number of neurological conditions defined by serological tests. However, despite improved immunoassay techniques, MRI of the brain and spinal cord continues to be among the first-line investigations in these patients, providing valuable diagnostic information that will help guide patient management. (orig.)

  8. Diagnosis of neuromyelitis optica (NMO) spectrum disorders: is MRI obsolete?

    International Nuclear Information System (INIS)

    Downer, Jonathan James; Carter, Ranjana; Kueker, Wilhelm; Quaghebeur, Gerardine; Leite, Maria Isabel; Palace, Jacqueline

    2012-01-01

    Neuromyelitis optica (NMO) is a severe demyelinating disease that preferentially involves spinal cord and optic nerve. It is part of a spectrum of neurological conditions associated with antibodies to aquaporin-4 (AQP4). This study investigates the role of MRI where novel, more sensitive AQP4 antibody immunoassay techniques are being used. Retrospective review of neuroimaging in 69 patients (25 antibody positive, 44 antibody negative), investigated in the context of suspected NMO or NMO spectrum disorder, was performed independently by two consultant neuroradiologists. Longitudinally extensive, central spinal cord lesions were more frequent in AQP4 positive patients (95.2% vs 35.5%, p < 0.0001; 85.7% vs 45.2%, p = 0.015). Multiple sclerosis diagnostic criteria were less frequently fulfilled on brain MRI in antibody positive patients (5.6% vs 33.3%, p = 0.035). Juxtacortical and corpus callosal lesions were also less common in this group (16.7% vs 46.7%, p = 0.063; 5.6% vs 46.7%, p = 0.0034). Hypothalamic and periependymal disease related to the aqueduct was not seen in antibody negative patients. T1 hypointensity was more common in cord lesions of antibody positive patients (75.0% vs 35.3%, p = 0.037). However, this characteristic did not discriminate antibody positive and negative longitudinally extensive cord lesions (73.3% vs 62.5%, p = 0.66). The NMO spectrum of diseases are among an increasing number of neurological conditions defined by serological tests. However, despite improved immunoassay techniques, MRI of the brain and spinal cord continues to be among the first-line investigations in these patients, providing valuable diagnostic information that will help guide patient management. (orig.)

  9. Neuromyelitis optica: a positive appraisal of seronegative cases.

    Science.gov (United States)

    Bernard-Valnet, R; Liblau, R S; Vukusic, S; Marignier, R

    2015-12-01

    Neuromyelitis optica (NMO) is a rare inflammatory disorder of the central nervous system. The hallmark of NMO is the presence of specific autoantibodies directed against aquaporin 4 (AQP4-IgG). AQP4-IgG, included in diagnostic criteria, has enlarged the clinical spectrum of NMO and serves to predict relapses. Moreover AQP4-IgG has provided unprecedented insight in the immunopathology of NMO, representing a rationale for therapeutic intervention with relevant novel treatment strategies specific for NMO. However, some patients remain seronegative for AQP4-IgG despite a definite diagnosis of NMO and the use of the finest methods for antibody detection. Interestingly, seronegative NMO (NMO(neg)) patients exhibit different demographic and disease-related characteristics in comparison to seropositive patients. The recent association with autoantibodies specific for myelin oligodendrocyte glycoprotein (MOG) is the main indication that disease mechanisms might differ in NMO(pos) and NMO(neg), challenging the position of NMO(neg) patients in the spectrum of demyelinating diseases and therapeutic strategies to be adopted. Thus, a reappraisal of the NMO(neg) population is needed to improve NMO care. Here the current knowledge regarding NMO(neg) is reviewed and hypotheses on its pathogenesis are made including a comprehensive description of detection methods and the prevalence of AQP4-IgG and a review of the epidemiological, clinical and paraclinical characteristics of NMO(neg); finally an integrated view of the general pathophysiological mechanisms underlying NMO(neg) is provided. © 2015 EAN.

  10. Gender differences among Chinese patients with neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Sun, Hui; Sun, Xuan; Li, Jie; Huo, Yunyun; Wu, Lei; Huang, Dehui; Yu, Shengyuan; Wu, Weiping

    2017-10-01

    Neuromyelitis optica spectrum disorders (NMOSD) are autoimmune, inflammatory demyelinating diseases of the central nervous system, which have established variations in prevalence across different ethnicities and genders. The objective of this study was to investigate differences in clinical features among men and women with NMOSD, according to the 2015 diagnostic criteria. A total of 97 patients with NMOSD were recruited from inpatient neurology clinics in this retrospective study. Demographic and clinical data were extracted from the various databases. Data on epidemiology, clinical signs, initial symptoms, and laboratory indices of men and women with NMOSD were compared. The cohort of this study had a female/male ratio of 5.47:1, with annualized relapse rates of 0.72 in female and 0.56 in male patients. Among female patients, 29.2% and 53.6% initially experienced acute optic neuritis and acute myelitis, respectively, while the prevalence of these symptoms was 46.6% and 53.3% among male patients. A total of 14.6% and 2.4% of female patients had area postrema symptoms and other brainstem signs, respectively on study enrollment. The prevalence of anti-AQP4-autoantibodies and anti-thyroid peroxidase autoantibodies/anti-thyroglobulin autoantibodies (TPO/TG-Ab) was significantly higher among women (77% and 45.7%) than among men (46.1% and 13.3%) (P < 0.05 for both comparisons). A total of 11 women with NMOSD (11.3% of the cohort) also had autoimmune diseases. Women with NMOSD have higher morbidity levels than men with this disease and are more likely to have autoimmune diseases and brainstem lesions, especially in the area postrema. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. White matter atrophy and cognitive dysfunctions in neuromyelitis optica.

    Directory of Open Access Journals (Sweden)

    Frederic Blanc

    Full Text Available Neuromyelitis optica (NMO is an inflammatory disease of central nervous system characterized by optic neuritis and longitudinally extensive acute transverse myelitis. NMO patients have cognitive dysfunctions but other clinical symptoms of brain origin are rare. In the present study, we aimed to investigate cognitive functions and brain volume in NMO. The study population consisted of 28 patients with NMO and 28 healthy control subjects matched for age, sex and educational level. We applied a French translation of the Brief Repeatable Battery (BRB-N to the NMO patients. Using SIENAx for global brain volume (Grey Matter, GM; White Matter, WM; and whole brain and VBM for focal brain volume (GM and WM, NMO patients and controls were compared. Voxel-level correlations between diminished brain concentration and cognitive performance for each tests were performed. Focal and global brain volume of NMO patients with and without cognitive impairment were also compared. Fifteen NMO patients (54% had cognitive impairment with memory, executive function, attention and speed of information processing deficits. Global and focal brain atrophy of WM but not Grey Matter (GM was found in the NMO patients group. The focal WM atrophy included the optic chiasm, pons, cerebellum, the corpus callosum and parts of the frontal, temporal and parietal lobes, including superior longitudinal fascicle. Visual memory, verbal memory, speed of information processing, short-term memory and executive functions were correlated to focal WM volumes. The comparison of patients with, to patients without cognitive impairment showed a clear decrease of global and focal WM, including brainstem, corticospinal tracts, corpus callosum but also superior and inferior longitudinal fascicles. Cognitive impairment in NMO patients is correlated to the decreased of global and focal WM volume of the brain. Further studies are needed to better understand the precise origin of cognitive impairment in

  12. STAT4 Polymorphisms are Associated with Neuromyelitis Optica Spectrum Disorders.

    Science.gov (United States)

    Shi, Ziyan; Zhang, Qin; Chen, Hongxi; Lian, Zhiyun; Liu, Ju; Feng, Huiru; Miao, Xiaohui; Du, Qin; Zhou, Hongyu

    2017-12-01

    STAT4 plays a crucial role in the functioning of the innate and adaptive immune cells and has been identified as a susceptibility gene in numerous autoimmune disorders. However, its association with neuromyelitis optica spectrum disorders (NMOSD) remains uncertain. Here, we performed a case-control study to determine whether STAT4 contributed to the risk of NMOSD. We tested five STAT4 SNPs in 233 patients with established NMOSD and 492 healthy controls. Chi-square tests and logistic regression analyses were performed with four genetic models, including allelic, additive, dominant, and recessive models, to identify associations with NMOSD. The results of multiple test comparisons were corrected using the Benjamini and Hochberg false discovery rate (FDR-BH). After correcting for multiple test comparisons, the minor alleles of four STAT4 SNPs exhibited significant association with increased risk of NMOSD (rs7574865 T, odds ratio [OR] = 1.66, 95% confidence interval [CI] 1.32-2.08, P corr  = 0.000; rs10181656 G, OR = 1.62, 95% CI 1.29-2.03, P corr  = 0.000; rs10168266 T, OR = 1.59, 95% CI 1.27-2.00, P corr  = 0.001; and rs13426947 A, OR = 1.51, 95% CI 1.21-1.90, P corr  = 0.004). Identical results were observed in the dominant, recessive, and additive models. In contrast, the G allele of rs7601754 displayed a protective effect against NMOSD (OR = 0.53, 95% CI 0.36-0.76, P corr  = 0.006). Our study indicates that STAT4 polymorphisms are associated with the risk of NMOSD, which provides novel insights into the underlying mechanisms of this disease.

  13. Features of anti-aquaporin 4 antibody-seropositive Chinese patients with neuromyelitis optica spectrum optic neuritis.

    Science.gov (United States)

    Li, Hongyang; Wang, Yanling; Xu, Quangang; Zhang, Aidi; Zhou, Huanfen; Zhao, Shuo; Kang, Hao; Peng, Chunxia; Cao, Shanshan; Wei, Shihui

    2015-10-01

    The detection of anti-aquaporin-4 autoantibody (AQP-4 Ab) is crucial to detect patients who will develop neuromyelitis optica (NMO); however, there are few studies on the AQP-4 Ab serostatus of patients with neuromyelitis optica spectrum ON. We analyzed the clinical and paraclinical features of neuromyelitis optica spectrum ON patients in China according to the patients' AQP4-Ab serostatus. 125 patients with recurrent and bilateral ON with simultaneous attacks were divided into AQP-4 Ab-seropositive and -seronegative groups. Demographic, clinical, serum autoantibody data, connective tissue disorders (CTDs), visual performance were compared. A Visual Acuity (VA) of less than 0.1 during acute ON attacks occurred more frequently in the seropositive group (p = 0.023); however, there was not a significant difference between groups on VA recovery after the first attack. The seropositive group experienced the worst outcome during the last attack (p = 0.017). Other co-existing autoimmunity antibodies (p optica spectrum ON.

  14. Neuromyelitis optica med udtalte cerebrale magnetisk resonans-skannings-forandringer hos en niårig pige

    DEFF Research Database (Denmark)

    Trautner, Simon; Pedersen, Hans Peder; Bendtson, Inger

    2009-01-01

    Neuromyelitis optica (NMO) is a rare inflammatory disorder characterised by optic neuritis and transverse myelitis. We report a severe pediatric case presenting with impaired vision, tetraparesis, bladder retention and lower extremity pain. Magnetic resonance imaging demonstrated longitudinally...

  15. Compuestos de organosilicio para almacenamiento de energía Compuestos de organosilicio para almacenamiento de energía

    Directory of Open Access Journals (Sweden)

    Adrián Peña-Hueso

    2012-02-01

    Full Text Available   Las pilas recargables de ion litio han tenido un considerable desarrollo en los últimos años y son ampliamente utilizadas en dispositivos electrónicos. Los derivados de organosilicio enlazados a unidades de etilenglicol están siendo estudiados como una opción atractiva para sustituir a los disolventes convencionales en la preparación de electrolitos, pues poseen altos puntos de inflamación, buena conductividad, baja toxicidad y buena estabilidad electroquímica. Aunado a eso, la síntesis de estos compuestos a partir de materias primas sencillas y económicas los convierte en buenos candidatos para su uso en pilas de ion litio a nivel comercial. En este artículo se hace una revisión de los aspectos más sobresalientes del trabajo con electrolitos de organosilanos que ha realizado el Dr. Robert West.There has been a large development of Li-ion batteries during last years and they are widely used in consumer electronic devices. Organosilicon compounds coupled to ethylene glycol chains are being studied as a good option to substitute conventional solvents in the preparation of electrolytes, because they have high flash points, good conductivities, low toxicity and good electrochemical stability. These compounds are prepared from simple and cheap reagents, which also makes them attractive for their industrial application in Li-ion batteries. This paper is a review of the most important results obtained by Professor Robert West in the field of organosilicon electrolytes.

  16. Neuromyelitis optica-IgG testing in an Indian cohort with neuromyelitis optica and related demyelinating disorders: Our experience

    Directory of Open Access Journals (Sweden)

    Narayanan Unni

    2013-01-01

    Full Text Available Background: Neuromyelitis optica (NMO is an immune-mediated inflammatory demyelinating disorder of the central nervous system with a predilection for the optic nerves and the spinal cord. Immunopathological evidence suggests that the target antigen of the disease is aquaporin-4. An IgG antibody against this protein has been explored as a molecular marker for the disease and as a diagnostic tool due to its high sensitivity and specificity in various populations. Objective: To assess the value of NMO-IgG testing in Indian patients with clinical and magnetic resonance imaging features consistent with NMO and longitudinally extensive transverse myelitis (LETM. Materials and Methods: Forty-five patients with clinical and magnetic resonance imaging features consistent with NMO, LETM, and MS were tested for serum NMO-IgG. Of these patients, 22 patients satisfied revised (2006 Wingerchuk criteria for NMO (excluding NMO-IgG status and 11 patients had LETM. Twelve patients satisfied the revised (2010 McDonald criteria for multiple sclerosis (MS. Results: Of the 21 patients, satisfying the criteria for NMO and for whom the test results were available, 17 were positive for NMO-IgG (80.9%, and of the 11 patients having LETM, 6 (54.5% were positive for NMO-IgG. In one patient with NMO, the test result was not available. None of the 12 patients satisfying McDonald criteria for MS showed NMO-IgG seropositivity. Conclusion: Our study suggests that it is worthwhile to pursue NMO-IgG testing as a diagnostic tool for patients with clinical and Magnetic Resonance Imaging (MRI features consistent with NMO and LETM in the Indian population.

  17. Influencia de los componentes del concreto reforzado con fibras en sus propiedades mecánicas

    OpenAIRE

    González Salcedo, Luis Octavio

    2013-01-01

    El concreto es un material de construcción y estructural por excelencia, elaborado con cemento, agua, agregados, adiciones minerales y aditivos químicos. Sin embargo, es conocido también como un material quebradizo, característica que es contrarrestada con la incorporación de un volumen de fibra como reforzamiento de su matriz basada en cemento. La incorporación de fibra hace que se denomine como concreto reforzado con fibra, o simplemente fibrorreforzado, y se caracteriza c...

  18. Plan estratégico Sudamericana de Fibras (2016-2020)

    OpenAIRE

    Herrera Chávez, Santiago; Leyva Forcelledo, Johanna; Ríos Oroz, Erika

    2016-01-01

    La presente investigación tiene como finalidad elaborar un plan estratégico para la empresa Sudamericana de Fibras S.A.; así como proponer recomendaciones con el fin que pueda crecer, en los niveles local y regional, con un modelo sostenible. La empresa Sudamericana de Fibras S.A. opera en el país desde el año 1972 y se dedica a la elaboración de fibras acrílicas, material que se encuentra al inicio de la cadena de suministro en el rubro textil, y permite otorgar propiedades extraordinarias a...

  19. Aplicaciones del cemento reforzado con fibra de vidrio (GRC

    Directory of Open Access Journals (Sweden)

    Barros Llerena, Ángel

    1981-12-01

    Full Text Available Not available.

    El presente artículo tiene como objeto dar a conocer la utilización de fibras de vidrio como refuerzo de los cementos. Se da una breve reseña histórica, se mencionan sus características y comportamiento. Además se presenta un caso práctico y reciente de utilización en la fabricación de elementos de fachada del Estadio «Santiago Bernabéu» del Real Madrid C. de F., y se completa con una relación de los actuales y futuros usos del G.R.C. (glass reinforced cement, denominación inglesa del material más comúnmente utilizado.

  20. CARACTERIZACIÓN DE LOS COMPUESTOS VOLÁTILES ACTIVOS OLFATIVAMENTE EN UCHUVA (Physalis peruviana L.

    Directory of Open Access Journals (Sweden)

    Doris Gutierrez

    2011-01-01

    Full Text Available Durante el estudio de los compuestos activos olfativamente en el aroma de la uchuva (Physalis peruviana L. se identificaron los compuestos volátiles, obtenidos por 3 técnicas, extracción líquido-líquido con pentano-diclorometano (1:1 (LL, Solvent-Assisted Flavor Evaporation (SAFE y Headspace-Microextracción en fase sólida (HS-MEFS, y se encontraron diferencias en la calidad del aroma de los extractos mediante el análisis olfatométrico. La técnica SAFE permitió obtener un extracto con un aroma muy semejante al de la fruta fresca. Los compuestos que presentaron los valores más altos de factor de dilución de aroma (FD fueron: hexanal, 3-hidroxi-2-butanona, 2-metilpropanol, 2-hidroxibutanoato de etilo, octanoato de etilo y 3-hidroxibutanoato de butilo. En el extracto LL se detectaron algunos compuestos sin actividad olfativa en la fruta; en contraste, mediante la técnica de HS-MEFS no fue posible detectar todos los compuestos activos olfativamente, principalmente los de mayor polaridad. Estos resultados muestran la utilidad del nuevo enfoque de análisis en química de aromas, el cual le da más relevancia al análisis olfativo en estos estudios.

  1. Microscopía electrónica para el estudio del Na2Si0(4 en la durabilidad de un compuesto a base de cemento portlánd y refuerzo de caoba Analysis of Na2Si0(4 effect on durability of a portlánd cement matrix and mahogany reinforcement composite through electron microscopy

    Directory of Open Access Journals (Sweden)

    Inocente Bojórque

    2007-12-01

    Full Text Available Con la ayuda de la microscopía electrónica, se logra apreciar el trabajo desarrollado por el silicato de sodio como agente mineraüzador de las fibras orgánicas en compuestos polifásicos con matriz de cemento Portland Tipo I. El objetivo de este trabajo fue el estudio de la acción del agente en la durabilidad del material, debido a la incompatibilidad química entre el hidróxido de calcio Ca(OH2 y el refuerzo a base de fibras procedentes de la caoba (Swietenia Macrophylla, en compuestos con características semejantes pero de tres diferentes edades y en compuestos de la misma edad pero elaborados con dos diferentes fracciones volumétricas del ingrediente orgánico. Los ensayos se realizaron en tres diferentes zonas: matriz, refuerzo y transición, empleando un Microscopio Electrónico de Barrido (MEB mientras que la composición química se hizo con un Analizador de Rayos "X" (EDS; a través del primer equipo se observó el contraste entre las diversas fases del compuesto por la diferencia entre los números atómicos; con el segundo, se analizó la composición química de las zonas de interés. Los resultados mostraron las bondades del agente en la durabilidad del material y, los beneficios del uso de la microscopía electrónica para visualizar el comportamiento microestructuralNa2Si0(4 behavior as a mineralizer agent on organic fibers composites with Type I Portland Cement matrix is possible to observe it through a Scanning Electron Microscope (SEM. The purpose of this research was to study the role of this agent on this material's durability due to the chemical incompatibility between calcium hydroxide Ca(OH2 and the fiber reinforcement from the mahogany (Swietenia Macrophylla, from composites of three different ages and two different fiber volumetric fraction as well. The tests were made in three different zones: matrix, reinforcement and transition zone, using a SEM, whereas the chemical composition was scanned out with an Energy

  2. ESTUDO DA SECAGEM DA FIBRA RESIDUAL DO ABACAXI

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    T. G. M. WAUGHON

    2009-01-01

    Full Text Available

    O objetivo deste trabalho foi caracterizar o resíduo fibroso gerado na industrialização do suco de abacaxi (Ananas comosus L. e estudar seu beneficiamento, através da secagem, visando obter um produto rico em fibras dietéticas. O resíduo caracterizado apresentou um elevado teor de fibras (32,95% b.s.. A secagem foi realizada em secador de leito fixo, em camada delgada, utilizando planejamento fatorial completo a três níveis, com triplicata no ponto central. As variáveis de entrada foram: temperatura (50 ºC, 60 ºC e 70ºC e velocidade de circulação do ar (2,0 m/s; 2,5 m/s e 3,0 m/s. As variáveis de resposta avaliadas foram: umidade de equilíbrio, tempo de secagem, taxa de secagem à velocidade constante e coloração do produto. Os resultados obtidos através da análise de variância mostraram que a temperatura foi a variável de entrada que apresentou maior influência sobre as variáveis de resposta analisadas, não exercendo influência significativa apenas sobre a cor do produto.

  3. Cognitive performance of neuromyelitis optica patients: comparison with multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Sandra Vanotti

    2013-06-01

    Full Text Available The aim of the present research was to investigate cognitive pattern of patients with neuromyelitis optica (NMO and to compare it with multiple sclerosis (MS patients' performance. Methods: Fourteen NMO, 14 relapsing remitting multiple sclerosis (RRMS, and 14 healthy control patients participated in the investigation. Neuropsychological functions were evaluated with the Brief Repeatable Neuropsychological Battery for MS; Symbol Digit Modalities Test; Digit Span; and Semantic Fluency. Results: Fifty-seven percent of NMO patients and 42.85% of the MS ones had abnormal performance in at least two cognitive tests. The NMO Group showed abnormal performance in verbal fluency, verbal and visual memories, with greater attention deficits. NMO patients outperformed healthy control in the paced auditory serial addition test (PASAT. However, no difference was found between NMO and RRMS patients. Conclusions: The NMO Group showed more dysfunction in attention and verbal fluencies than in verbal and visual memories. When compared with the MS patients, a similar dysfunction pattern was found. O objetivo da presente pesquisa foi investigar o padrão cognitivo de pacientes com neuromielite óptica (NMO e compará-lo com o desempenho de pacientes com esclerose múltipla (EM. Métodos: Quatorze pacientes com NMO, 14 com esclerose múltipla recorrente remitente (EMRR e 14 participantes do Controle saudáveis participaram da presente investigação. As funções neuropsicológicas foram avaliadas com a Bateria Breve de Testes Neuropsicológicos de Rao, Teste Símbolo Digit e a Fluência Semântica. Resultados: Cinquenta e sete por cento dos pacientes com NMO e 42,85% daqueles com EM apresentaram desempenho anormal em pelo menos dois testes cognitivos. O Grupo NMO apresentarou desempenho anormal na fluência verbal e nas memórias visual e verbal, com maiores déficits de atenção. Pacientes com NMO superaram os controles saudáveis em PASAT. No entanto, não foi

  4. Early and extensive spinal white matter involvement in neuromyelitis optica.

    Science.gov (United States)

    Hayashida, Shotaro; Masaki, Katsuhisa; Yonekawa, Tomomi; Suzuki, Satoshi O; Hiwatashi, Akio; Matsushita, Takuya; Watanabe, Mitsuru; Yamasaki, Ryo; Suenaga, Toshihiko; Iwaki, Toru; Murai, Hiroyuki; Kira, Jun-Ichi

    2017-05-01

    Studies of longitudinally extensive spinal cord lesions (LESCLs) in neuromyelitis optica (NMO) have focused on gray matter, where the relevant antigen, aquaporin-4 (AQP4), is abundant. Because spinal white matter pathology in NMO is not well characterized, we aimed to clarify spinal white matter pathology of LESCLs in NMO. We analyzed 50 spinal cord lesions from eleven autopsied NMO/NMO spectrum disorder (NMOSD) cases. We also evaluated LESCLs with three or fewer spinal cord attacks by 3-tesla MRI in 15 AQP4 antibody-positive NMO/NMOSD patients and in 15 AQP4 antibody-negative multiple sclerosis (MS) patients. Pathological analysis revealed seven cases of AQP4 loss and four predominantly demyelinating cases. Forty-four lesions from AQP4 loss cases involved significantly more frequently posterior columns (PC) and lateral columns (LC) than anterior columns (AC) (59.1%, 63.6%, and 34.1%, respectively). The posterior horn (PH), central portion (CP), and anterior horn (AH) were similarly affected (38.6%, 36.4% and 31.8%, respectively). Isolated perivascular inflammatory lesions with selective loss of astrocyte endfoot proteins, AQP4 and connexin 43, were present only in white matter and were more frequent in PC and LC than in AC (22.7%, 29.5% and 2.3%, P corr  = 0.020, and P corr  = 0.004, respectively). MRI indicated LESCLs more frequently affected PC and LC than AC in anti-AQP4 antibody-seropositive NMO/NMOSD (86.7%, 60.0% and 20.0%, P corr  = 0.005, and P corr  = 0.043, respectively) and AQP4 antibody-seronegative MS patients (86.7%, 73.3% and 33.3%, P corr  = 0.063, and P corr  = 0.043, respectively). PH, CP and AH were involved in 93.3%, 86.7% and 73.3% of seropositive patients, respectively, and in 53.3%, 60.0% and 40.0% of seronegative patients, respectively. NMO frequently and extensively affects spinal white matter in addition to central gray matter, especially in PC and LC, where isolated perivascular lesions with astrocyte endfoot

  5. Adult methylmalonic acidemia presented as neuromyelitis optica: one case report

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    Sheng-de LI

    2015-10-01

    Full Text Available A 26-year-old male was admitted to our department, complaining of cognitive impairment, urine incontinence for 3 months, blurred vision for one month and numbness of bilateral lower limbs for 20 days. Presumed as “depression” and “viral encephalitis”, antidepressant and dexamethasone had been given but had no response. Neurological examination demonstrated impaired orientation to time and place; hearing impairment of right ear; normal muscle force in upper limbs, proximal lower muscle force was 2 and distal was 0; normal tendon reflex in both upper limbs; diminished tendon reflex in both lower limbs; left palmomental reflex (+; bilateral Babinski sign (+. Below T10: diminished superficial, deep sensation and cortical sensory. Cranial MRI on admission revealed widened sulci in bilateral cleft and frontal, temporal and insular lobes, indicating brain atrophy. Spinal MRI revealed high-intensity signals of C3-7 level and T1-12 level. The patient was diagnosed as “neuromyelitis optica (NMO” at first, but cognitive impairment is really rare in NMO. It finally turned out to be “inherited metabolic diseases” with the negative results of aquaporin 4 (AQP4, NMO-IgG, GM1, voltage-gated potassium channel (VGKC from serum and cerebrospinal fluid (CSF. The elevated level of plasm homocysteine [30.79 mmol/L (5-20 mmol/L] and urine methylmalonic acid [0.40 mmol/L (0.001 mmol/L] ascertained the diagnosis of methylmalonic acidemia. The patient was given oral treatment of folate 5 mg (3 times a day, 13 days and levocarnitine 1 g (3 times a day, 8 days and intramuscular injection of mecobalamine 1mg (once a day, 4 days or 0.50 mg (once a day, 8 days and adenosylcobalamine 0.50 mg (once a day, 8 days. Sixteen days on discharge, the patient’s neurological examination revealed no obvious recovery of vision; lower muscle force: about Ⅳ, right sensory level: T12-L1, and left sensory level lowered to L3. Reexamination of MRI revealed brain atrophy

  6. El envejecimiento de las pastas de cemento reforzadas con fibras de vidrio

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    Sánchez Paradela, M. L.

    1992-06-01

    Full Text Available Cement pastes reinforced with glassfibre, popularly called GRC ("Glassfibre Reinforced Cements" are compound materials which have been widely used in the construction field for the last 30 years. Their good mechanical properties, lightness and resistance to corrosion and fire make them suitable in the process of replacing the fibrocements with asbestos base in numerous applications. For that reason, their use has been extended in recent years and they have mainly been used to manufacture panels for facades and interior decoration as well as, to a smaller extent, for plumbing installations, roofs, lost formwork and even for "fingers" at the airports (1, 2, 3, 4, 5. Nevertheless, it has been known for over 25 years that GRC suffer deterioration with the time which affects their mechanical properties and especially their tenacity; they become fragile and crack under small deformations. The research carried out to determine the causes of the phenomenon and look for possible solutions has been intense and it would be impossible to give more details here due to the lack of space. We will try, nevertheless, to summarize some more relevant aspects of the problem and the solutions that have reached the highest point of development so far.

    Las pastas de cemento reforzadas con fibras de vidrio, denominadas popularmente GRC ("Glassfibre Reinforced Cements", son materiales compuestos que se utilizan ampliamente en el campo de la Construcción desde hace unos 30 años. Sus buenas propiedades mecánicas, ligereza y resistencia a la corrosión y al fuego les hacen idóneos en el proceso de sustitución de los fibrocementos de base amianto en numerosas aplicaciones. Por tal motivo, su empleo se ha extendido en los últimos años, utilizándose fundamentalmente para fabricar paneles de cierre de fachadas y decoración de interiores y en menor grado para tuberías, cubiertas, encofrados permanentes e incluso para "fingers" o brazos de acceso a los aviones

  7. Estudio de la fractura de materiales compuestos por una matriz de plástico

    OpenAIRE

    Maspoch, M. Ll. (Maria Lluïsa)

    1992-01-01

    Se estudia el comportamiento a fractura de materiales, compuestos por una matriz de plástico en la que se ha dispersado una segunda fase en forma de partículas elastoméricas. Como matriz se han utilizado dos materiales diferentes: una resina de poliéster insaturada y poliestireno. Se estudia la morfología de los materiales compuestos preparados, se determinan los parámetros de fractura y otras propiedades mecánicas, se realiza el estudio fractográfico y finalmente se analizan los resultados e...

  8. El CITA realiza estudios sobre compuestos nutraceúticos en pimiento y cebolla

    OpenAIRE

    Area de Información, Documentación y Cultura Científica. Centro de Investigación y Tecnología Agroalimentaria de Aragón

    2013-01-01

    Se está trabajando en la detección de compuestos nutracéuticos ( sustancias de origen biológico beneficiosas para la salud) en pimiento y cebolla y que son potencialmente muy útiles para el sector farmacéutico. El Centro de Investigación y Tecnología Agroalimentaria de Aragón, organismo perteneciente al Departamento de Industria e Innovación, está desarrollando técnicas analíticas y moleculares para el estudio de compuestos nutraceúticos en pimiento y cebolla. La investigación esta ...

  9. Eliminación de compuestos volátiles olorosos por electrocoagulación

    OpenAIRE

    Mariz Medeiros, Djalma; Hernández Muñoz, Aurelio; Hernández Lehmann, Aurelio; Lucas Filho, Manoel

    2011-01-01

    La emisión de olores en las depuradoras de aguas residuales representa un impacto significativo. En este sentido, resulta de especial interés la electrocoagulación, como procedimiento de tratamiento de compuestos olorosos presentes en aguas residuales. Durante la presente investigación se ha estudiado la eliminación de los siguientes compuestos volátiles olorosos mediante el proceso de electrocoagulación: sulfuro de carbono, tolueno y diclorometano. Se ha investigado el efecto del diseño del...

  10. Material compuesto electroconductor con coeficiente de expansión térmica controlado

    OpenAIRE

    Borrell, Amparo; García Moreno, Olga; Fernández, Adolfo; Torrecillas, Ramón

    2009-01-01

    Material compuesto electroconductor con coeficiente de expansión térmica controlado. La presente invención se refiere a un material compuesto que comprende un componente cerámico, caracterizado por tener un coeficiente de expansión térmico negativo, y nanofilamentos de carbono, a su procedimiento de obtención y a sus usos como electroconductor en microelectrónica, óptica de precisión, aeronáutica y aeroespacial.

  11. USO DE LÁMINAS PULTRUÍDAS DE POLÍMEROS REFORZADOS CON FIBRA DE VIDRIO PARA INCREMENTAR LA RESISTENCIA A FLEXIÓN DE VIGAS DE HORMIGÓN ARMADO

    Directory of Open Access Journals (Sweden)

    A. Busnelli

    2016-06-01

    Full Text Available Por medio de este artículo se presenta el estudio que se viene realizando en la Facultad de Ingeniería de Rosario, en referencia al uso de láminas pultruídas de Polímeros Reforzados con Fibra de Vidrio (PRFV para incrementar la resistencia a flexión de vigas de hormigón armado, siendo dichas láminas unos de los elementos de materiales compuestos más empleados para este tipo de refuerzos. El material de mayor difusión a nivel mundial que lo constituye son las de fibras de carbono, pero su elevado costo desalienta la utilización en la reparación de estructuras en el mercado argentino. Uno de los objetivos de este programa de investigación, es comprobar la posibilidad de sustitución de dichas láminas por elementos de fibra de vidrio de fabricación nacional significativamente más económicos. Los resultados obtenidos en los ensayos demostraron la factibilidad de esta alternativa. Además, el mayor espesor de las láminas de fibra de vidrio permite el uso de anclajes adicionales abulonados, que otorgan al sistema capacidad portante post crítica y ductilidad, características muy necesarias, por ejemplo, para las estructuras en zona sísmica. Through this article the study being done at the Faculty of Engineering of Rosario, referring to the use of sheets pultruded Reinforced Polymer Fiberglass (GRP to increase the bending strength of reinforced concrete beams is presented, THESE layers are one of the elements of compound materials most commonly used in these type of reinforcements. The material most widely distributed worldwide that constitutes it is the carbon fibers, but its high cost discourages the use in the repair of structures in the Argentine market. One of the goals of this research program is to check the possibility of replacing such sheets by fiberglass elements of Argentinean production and significantly cheaper. The results of the tests demonstrated the feasibility of this alternative. In addition, the increased

  12. Síndrome de Straatsma. Caso familiar de mielinización de fibras nerviosas

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    Fanny Campos-Jiménez

    2014-01-01

    Full Text Available En condiciones normales sólo ocurre mielinización de fibras del nervio óptico por detrás de la lámina cribosa, pero se observa mielinización de parte de la capa de fibras nerviosas de la retina en el 0.32% a 0.98% de los pacientes. la mielinización intraocular generalmente es yuxtapapilar, y las fibras toman un aspecto característico: manchas blancas, nacaradas, parecidas a una pluma, que siguen la dirección de las fibras de la retina y a veces ocultan la papila. Aparte de estas características fundoscópicas, la mayoría de los pacientes son normales. Se ha encontrado que puede haber una asociación entre la mielinización de las fibras de la retina y una miopía ipsilateral, y también se ha observado ambliopía y estrabismo. Se describe un caso de mielinización de fibras nerviosas, en madre e hija, hecho que sugiere un factor genético en su génesis.

  13. Evaluación de rendimiento de compuestos de ajo tipo Taiwán Evaluación de rendimiento de compuestos de ajo tipo Taiwán

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    Briseida Mendoza Celedón

    2012-02-01

    Full Text Available Se evaluó el rendimiento y variables de calidad de compuestos de ajo (Allium sativum L., durante el ciclo otoño-invierno 2008-2009, en San Luis de la Paz, Gto., México. Se emplearon compuestos de ajo del tipo Taiwán, con resultados variables de acuerdo a su genotipo. Entre los compuestos sobresalieron por su altura de planta, rendimiento de bulbo, mayor peso promedio de bulbo y menor número de dientes por bulbo los siguientes: el Compuesto 4 (El pato, bodegas, Salamanca, Gto., el Compuesto 5 (Santa Teresa, tabla III, Salamanca, Gto., y el Compuesto 1 (Ajo sano, varias regiones del Edo. de Gto.. Es importante continuar con el programa de mejoramiento genético de ajo para el estado de Guanajuato, basado en selección de nuevas líneas de entre los compuestos mejores y con ayuda de técnicas como la eliminación de virus, para mejorar rendimiento y calidad del ajo. Field yield and bulb quality of garlic (Allium sativum L. compounds were evaluated during the 2008-2009 fall-winter cycle at the San Luis de la Paz, Gto., Mexico. Taiwan compounds were evaluated with variable results, depending on the genotype. Best plant height, bulb yield, higher weight per bulb and smaller clove number per bulb were obtained with: Compuesto 4 (El pato, bodegas, Salamanca, Gto., Compuesto 5 (Santa Teresa, tabla III, Salamanca, Gto., and Compuesto 1 (Ajo sano, varias regiones del Edo. de Gto.. It is important to continue with the program of garlic genetic breeding to Guanajuato state, based on selection of new garlic lines derived from the best compounds and using techniques as the virus elimination for improving yield and quality.

  14. Modelación del módulo de la resistencia a la flexión de un material compuesto cementicio a partir de propiedades en estado fresco

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    Fernando Toro

    2014-01-01

    Full Text Available En la presente investigación se estudió la relación entre las propiedades del estado fresco y el estado endurecido de un material compuesto formado por una matriz de cemento Pórtland reforzado con fibra de fique dispuestas al azar, las propiedades evaluadas en estado fresco fueron: ondulabilidad, fluidez, drenabilidad y en estado endurecido el módulo de la resistencia a la flexión. Las muestras se prepararon con diferentes materias primas (Fibra de fique, Bentonita, Pulpa, Humo de Sílice y Acronal, las componentes se agregaron a una mezcladora a velocidad constante, luego se vertió la mezcla en una cámara de drenado donde se extrajo el agua y se conformó la lámina con dimensiones de 130x50x6 mm, luego se sumergió en una piscina de curado por 28 días para ser evaluado el módulo de la resistencia a la flexión. El modelo de regresión lineal que se propuso para predecir el módulo de la resistencia a la flexión, en función de las propiedades en estado fresco, se realizó a través del análisis de las interacciones entre las variables de la formulación de la mezcla utilizada. Como resultado del modelo de regresión se obtuvo que existe una clara correlación entre el módulo de la resistencia a la flexión y las propiedades predictoras ondulabilidad, fluidez y drenabilidad, además estas tienen un efecto negativo sobre el módulo de la resistencia a la flexión.

  15. Treatment-resistant neuromyelitis optica spectrum disorders associated with Toxocara canis infection: A case report.

    Science.gov (United States)

    Kambe, Daisuke; Takeoka, Kayo; Ogawa, Kenta; Doi, Kosuke; Maruyama, Haruhiko; Yoshida, Ayako; Suenaga, Toshihiko; Kageyama, Takashi

    2017-04-01

    A 53-year-old woman was admitted to the department of neurology in Tenri Hospital because of progressive thoracic myelitis a month after she had eaten uncooked bovine liver. A previous episode of right optic neuritis and a positive test for serum anti-aquaporin-4 antibodies indicated a diagnosis of neuromyelitis optica spectrum disorders. Although the patient initially recovered with the reduction of anti-aquaporin-4 antibodies during treatment with intravenous methylprednisolone infusion and plasma exchange, her neurological symptoms deteriorated soon after the completion of plasma exchange. Western blotting analysis detected anti-Toxocara canis antibodies in the serum; thus, the patient underwent oral albendazole treatment. This resulted in the alleviation of her symptoms. We therefore consider that rigorous investigation should be encouraged to detect rare pathogens including parasites in cases of treatment-resistant neuromyelitis optica spectrum disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Seronegative neuromyelitis optica spectrum disorder patients diagnosed using new diagnostic criteria.

    Science.gov (United States)

    Uzawa, Akiyuki; Mori, Masahiro; Uchida, Tomohiko; Masuda, Hiroki; Ohtani, Ryohei; Kuwabara, Satoshi

    2016-09-01

    Recently, new diagnostic criteria for neuromyelitis optica spectrum disorders (NMOSD) were published. Our primary aim was to evaluate the usefulness of the new diagnostic criteria in anti-aquaporin 4 (AQP4) antibody-negative cases. Consecutive 471 patients whose anti-AQP4 antibody was measured at Chiba University were reviewed. Four anti-AQP4 antibody negative-patients, who fulfilled the new diagnostic criteria for NMOSD but not 2006 diagnostic criteria for neuromyelitis optica (NMO), were identified. They showed high cerebrospinal fluid interleukin-6 and glial fibrillary acidic protein levels, an absence of oligoclonal bands and/or cloud-like enhancement on magnetic resonance imaging, which are compatible findings for NMO. The new diagnostic criteria are clinically useful in seronegative NMOSD. © The Author(s), 2015.

  17. Painful tonic spasms and brainstem involvement in a patient with neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Roman-Filip, Corina; Ungureanu, Aurelian; Cernuşcă-Miţaru, Mihaela

    2016-01-01

    Neuromyelitis optica (NMO) is an inflammatory-demyelinating disease of the central nervous system classically characterized by optic neuritis and severe myelitis. New diagnostic criteria defined neuromyelitis optica spectrum disorder as limited forms of NMO or diverse neurologic presentations in the presence of specific antiaquaporin-4 antibodies. We report the case of a 57-year-old woman admitted in our department for recurrent attacks of optic neuritis, tetraparesis with severe painful tonic spasms of the left limbs and brainstem involvement. Painful tonic spasms have been described as movement disorders associated with multiple sclerosis, but a growing number of reports describe them in cases of NMO. Copyright © 2015 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  18. Neuromyelitis Optica: An Often Forgotten Cause of Intractable Nausea and Vomiting

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    Chijioke Enweluzo

    2013-07-01

    Full Text Available Neuromyelitis optica, also known as Devic's disease, is a rare autoimmune disorder in which a patient's immune system affects the optic nerves and the spinal cord, leading to loss of vision and spinal cord dysfunction. We present our experience with a 38-year-old female who presented to our facility with complaints of intractable nausea and vomiting. After extensive evaluation, she was found to have neuromyelitis optica. Her symptoms completely resolved following institution of appropriate therapy. She made a significant recovery and has since been placed on chronic immunosuppressive therapy. Through this article we hope to bring attention to a significant cause of intractable nausea and vomiting that may often be forgotten in general medicine or gastroenterology services.

  19. Acute Respiratory Failure due to Neuromyelitis Optica Treated Successfully with Plasmapheresis

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    Massa Zantah

    2016-01-01

    Full Text Available Neuromyelitis Optica (NMO is a demyelinating autoimmune disease involving the central nervous system. Acute respiratory failure from cervical myelitis due to NMO is known to occur but is uncommon in monophasic disease and is treated with high dose steroids. We report a case of a patient with NMO who developed acute respiratory failure related to cervical spinal cord involvement, refractory to pulse dose steroid therapy, which resolved with plasmapheresis.

  20. Neuromyelitis optica presenting with horner syndrome: A case report and review of literature.

    Science.gov (United States)

    Uludağ, İrem Fatma; Sarıteke, Alp; Öcek, Levent; Zorlu, Yaşar; Şener, Ufuk; Tokuçoğlu, Figen; Uludağ, Burhanettin

    2017-05-01

    Neuromyelitis optica (NMO) is a demyelinating disease of the central nervous system that predominantly affects the spinal cord and optic nerves. We describe a 19 years old woman with left Horner syndrome (HS), who was diagnosed as NMO with characteristic longitudinally extensive myelitis and positive serum aquaporin-4 immunoglobulin G antibodies (AQP4-IgG). Our report describes one of the very rare ocular motor symptoms in NMO patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Comportamiento mecánico de fibras henequén cubano e interfase con polímeros termoplásticos del tipo poliolefina//Mechanical behavior of Cuban henequen fibers and interphase with thermoplastic polymers of the polyolefin family

    Directory of Open Access Journals (Sweden)

    Daniel Díaz-Batista

    2015-09-01

    Full Text Available El aprovechamiento de las fibras lignocelulósicas de agave fourcroydes o henequén, cultivado en las condiciones de Cuba,  para el diseño de un material compuesto con matriz de termoplástico, demandó conocer su comportamiento mecánico y el de la interfase con los polímeros propuestos como matriz. Se ensayaron fibras de la región de Limonar provincia de Matanzas, encontrándose valores de resistencia típicos de 500 MPa, mostrándose además estadísticas de otros parámetros como el área de la fibra y la relación perímetro-área. La interacción con polietileno de baja densidad dio como resultado un valor de resistencia al corte interfacial de 5,6 MPa, en cambio utilizando el copolímero de etileno 1-hexeno se alcanzó 8,4 MPa. Para estas condiciones se obtuvo longitudes críticas de 8,1 milímetros y menores. Se presentó una forma de preparación de las muestras para el ensayo de desprendimiento a tracción y un diseño de dispositivo para llevar a cabo esta prueba. Palabras clave: henequén, polímero termoplástico, fibra lignocelulósica, interfase, material compuesto______________________________________________________________________________AbstractIncorporating fibers from agave fourcroydes, also named henequen, grown in Cuban farm conditions, into thermoplastic-matrix compositedesign took evaluating mechanical behavior of both the fiber and interphase with polymeric matrix candidates. Fibers from Limonar area in the province of Matanzas were tested, finding 500 MPa as typical tensile strength value. Statistical of fiber cross sectional area and perimeter to cross sectional area ratio is also showed. Fiber interaction with low density polyethylene yielded an interphase shear strength equal to 5.6 MPa but increased to 8.4 interacting with ethylene 1-hexene copolymer. For these experimental conditions, critical lengths of 8.1 millimeters and shorter were obtained. Are also presented both, an alternative to prepare pull-out test

  2. Análisis de compuestos volátiles en cilantro ( L. Análisis de compuestos volátiles en cilantro (Coriandrum sativum L.

    Directory of Open Access Journals (Sweden)

    Tábata Rosales-Reyes

    2012-02-01

    Full Text Available In the present study, volatile compounds were recovered from the fresh leaves and stems ofcilantro (Coriandrum sativum L. by two methods: Liquid-Solid Extraction (LSE and SimultaneousDistillation-Extraction (SDE. The identification and quantification was done byGas Chromatography-Mass Spectrometry (GC-MS. Fourteen compounds were characterizedby LSE and GC-MS; whereas by SDE and GC-MS, they were twenty three compounds.The statistical analysis revealed significant quantitative differences (p ≤ 0,05 between theanalyzed techniques (LSE and SDE. In this work, the Simultaneous Distillation-Extractionshowed the greater identification and total concentration of volatile compounds. Aldehydes,monoterpenes, and alcohols comprised 78% of the volatile found for two methods, the restwere hydrocarbons. (E-2-decenal was the most abundant compound in cilantro in bothextraction techniques. En el presente estudio se recuperaron los compuestos volátiles de las hojas y los tallos frescos de cilantro (Coriandrum sativum L. mediante dos métodos: Extracción Sólido Líquido (LSE y Extracción-Destilación Simultánea (SDE. La identificación y cuantificación fue por Cromatografía de Gases-Espectrometría de Masas (GC-MS. Se caracterizaron catorce compuestos por LSE y GC-MS; mientras que por SDE y GC-MS, fueron veintitrés compuestos. El análisis estadístico reveló significativas diferencias cuantitativas (p ≤ 0,05 entre las técnicas analizadas (LSE y SDE. En este trabajo, la Extracción-Destilación Simultánea arrojó la mayor identificación y concentración total de compuestos volátiles. Los aldehídos, monoterpenos y alcoholes comprendieron el 78% de los volátiles encontrados por los dos métodos, el resto fueron hidrocarburos. En ambas técnicas de extracción el (E-2-decenal fue el compuesto más abundante en el cilantro.

  3. A Rare Case of Neuromyelitis Optica Spectrum Disorder in Patient with Sjogren’s Syndrome

    Directory of Open Access Journals (Sweden)

    Supat Thongpooswan

    2014-01-01

    Full Text Available We report a 48-year-old female with the history of Sjogren’s syndrome who presented with 3-week history of tingling, numbness, and shooting back, waist, and bilateral leg pain and numbness in the pelvic region with urinary and bowel incontinence. Physical examination was remarkable for reduced motor power in both lower extremities with spasticity. Sensory deficit was noted at the T6 level. Laboratory investigation revealed elevated ESR and CRP and positive serum antiaquaporin-4 IgG. Thoracic and lumbar magnetic resonance imaging revealed abnormal patchy areas, leptomeningeal enhancement through the thoracic cord extending from T3 through T6 levels, without evidence of cord compression. Impression of neuromyelitis optica spectrum disorder was made and patient was treated with methylprednisolone intravenously followed by tapering oral prednisone. Neurological symptoms gradually improved with resolution of bowel and urinary incontinence. In a patient with Sjogren’s syndrome who presents with neurological complaints, the possibility of neuromyelitis optica or neuromyelitis optica spectrum disorder should be considered. Awareness of the possibility of CNS disease is important due to the serious nature of CNS complications, some of which are treatable with immunosuppressants. Our patient with Sjogren’s syndrome who presented with myelopathy benefited from early recognition and institution of appropriate therapy.

  4. Clinical characteristics of late-onset neuromyelitis optica spectrum disorder: A multicenter retrospective study in Korea.

    Science.gov (United States)

    Seok, Jin Myoung; Cho, Hye-Jin; Ahn, Suk-Won; Cho, Eun Bin; Park, Min Su; Joo, In-Soo; Shin, Ha Young; Kim, Sun-Young; Kim, Byung-Jo; Kim, Jong Kuk; Cho, Joong-Yang; Huh, So-Young; Kwon, Ohyun; Lee, Kwang-Ho; Kim, Byoung Joon; Min, Ju-Hong

    2017-11-01

    There are currently few studies regarding late-onset neuromyelitis optica spectrum disorder (LO-NMOSD). We aimed to describe the characteristic features of patients with LO-NMOSD in Korea. Anti-aquaporin-4 antibody-positive patients with neuromyelitis optica spectrum disorder (NMOSD) from nine tertiary hospitals were reviewed retrospectively. The patients were divided into two groups based on age of onset: LO-NMOSD (⩾50 years of age at onset) versus early-onset neuromyelitis optica spectrum disorder (EO-NMOSD) (<50 years of age at onset). Clinical, laboratory, and magnetic resonance imaging (MRI) parameters were investigated. Among a total of 147 patients (125 female; age of onset, 39.4 ± 15.2 years), 45 patients (30.6%) had an age of onset of more than 50 years. Compared to patients with EO-NMOSD, patients with LO-NMOSD had more frequent isolated spinal cord involvement at onset (64.4% vs 37.2%, p = 0.002), less frequent involvement of the optic nerve (40.0% vs 67.7%, p = 0.002), and less frequent brain MRI lesions (31.1% vs 50.0%, p = 0.034). Furthermore, there was a significant positive correlation between age of onset and Expanded Disability Status Scale (EDSS) score at last follow-up ( r = 0.246, p = 0.003). Age of onset could be an important predictor of lesion location and clinical course of patients with NMOSD.

  5. New onset neuromyelitis optica in a young Nigerian woman with possible antiphospholipid syndrome: a case report

    Directory of Open Access Journals (Sweden)

    Komolafe Morenikeji A

    2008-11-01

    Full Text Available Abstract Introduction Devic's neuromyelitis optica is an inflammatory demyelinating disease that targets the optic nerves and spinal cord. It has a worldwide distribution and distinctive features that distinguish it from multiple sclerosis. There has been no previous report of neuromyelitis optica from our practice environment, and we are not aware of any case associated with antiphospholipid syndrome in an African person. Case presentation We report the case of a 28-year-old Nigerian woman who presented with neck pain, paroxysmal tonic spasms, a positive Lhermitte's sign and spastic quadriplegia. She later developed bilateral optic neuritis and had clinical and biochemical features of antiphospholipid syndrome. Her initial magnetic resonance imaging showed a central linear hyperintense focus in the intramedullary portion of C2 to C4. Repeat magnetic resonance imaging after treatment revealed resolution of the signal intensity noticed earlier. Conclusion Neuromyelitis optica should be considered in the differential diagnoses of acute myelopathy in Africans. We also highlight the unusual association with antiphospholipid syndrome. Physicians should screen such patients for autoimmune disorders.

  6. Diffusion tensor imaging of brain in relapsing neuromyelitis optica

    International Nuclear Information System (INIS)

    Yu Chunshui; Li Kuncheng; Qin Wen; Lin Fuchun; Jiang Tianzi

    2007-01-01

    Objective: To investigate the presence of occult brain tissue damage in patients with relapsing neuromyelitis optica (RNMO) and its possible mechanism by using diffusion tensor imaging (DTI). Methods: DTI scans were performed in 16 patients with RNMO and 16 sex- and age-matched healthy controls. Histogram analysis of mean diffusivity (MD) and fractional anisotropy (FA) was performed in brain tissue (BT), white matter (WM) and gray matter (GM) to detect the presence of occult brain tissue damage in RNMO patients. Region of interest (ROI) analysis of MD and FA was also performed in 6 dedicated regions with or without direct connection with spinal cord or optic nerve to determine the relationship between occult brain tissue damage and the damage of spinal cord and optic nerve. Results Patients with RNMO had a significantly higher average MD of the BT [RNMO (0.95 ± 0.02) x 10 -3 mm 2 /s, controls (0.91 ± 0.03) x 10 -3 mm 2 /s, t=3.940, P -3 mm 2 /s, controls(0.80 ± 0.02) x 10 -3 mm 2 /s, t=3.117, P=0.004] an.d GM [RNMO (1.06 ± 0.04) x 10 -3 mm 2 /s, controls (0.88 ± 0.05) x 10 -3 mm 2 /s, t=4.031, P -3 mm 2 /s, controls (0.81 ± 0.02) x 10 -3 mm 2 /s, t=4.373, P -3 mm 2 /s, controls (1.11 ± 0.10) x 10 -3 mm 2 /s, t=4.260, P -3 mm 2 /s, controls (0.87 ± 0.05) x 10 -3 mm 2 /s, t4.391, P -3 mm 2 /s, controls (0.72 ± O.01) x 10 -3 mm 2 /s, t=4.683, P -3 mm 2 /s, controls (0.82+0.03) x 10-3 mm2/s, t = 4. 619, P -3 mm 2 /s, controls (0.73±0.03) x 10 -3 mm 2 /s, t =2.804, P=0.009 and splenium of corpus callosum: RNMO(0.77 ± 0.05) x 10 -3 mm 2 /s, controls (0.73 ± 0.04) x 10 -3 mm 2 /s, t=2.234, P=0.033] and FA [genu of corpus callosum: RNMO 0.82± 0.03 ,controls 0.82 ± 0.03, t=0.196, P=0.846 and splenium of corpus caltosum: RNMO 0.83±0.03, controls 0.83 ± 0.02, t=0.333, P=0.741] between RNMO patients and controls. Conclusion: RNMO patients have occult brain tissue damage, which might be related to the antegrade and retrograde degeneration secondary to lesions in

  7. A Novel MK-based Geopolymer Composite Activated with Rice Husk Ash and KOH: Performance at High Temperature; Nuevo material compuesto de matriz geopolimérica activado con ceniza de cascarilla de arroz y KOH: Desempeño a alta temperatura.

    Energy Technology Data Exchange (ETDEWEB)

    Villaquirán-Caicedo, M.A.; Mejía de Gutiérrez, R.; Gallego, N.C.

    2017-07-01

    Geopolymers were produced using an environmentally friendly alkali activator (based on Rice Husk Ash and potassium hydroxide). Aluminosilicates particles, carbon and ceramic fibres were used as reinforcement materials. The effects of reinforcement materials on the flexural strength, linear-shrinkage, thermophysical properties and microstructure of the geopolymers at room and high temperature (1200 °C) were studied. The results indicated that the toughness of the composites is increased 110.4% for geopolymer reinforced by ceramic fibres (G-AF) at room temperature. The presence of particles improved the flexural behaviour 265% for geopolymer reinforced by carbon fibres and particles after exposure to 1200 .C. Linear-shrinkage for geopolymer reinforced by ceramic fibres and particles and the geopolymer G-AF compared with reference sample (without fibres and particles) is improved by 27.88% and 7.88% respectively at 900 °C. The geopolymer materials developed in this work are porous materials with low thermal conductivity and good mechanical properties with potential thermal insulation applications for building applications. [Spanish] Compuestos geopoliméricos fueron producidos usando un activador alcalino alternativo (basado en ceniza de cascarilla de arroz e hidróxido de potasio), partículas aluminosilicatos, fibras de carbono y cerámicas. Se estudió el efecto de fibras y partículas en la resistencia a la flexión, contracción lineal, propiedades termofísicas y microestructura de los geopolímeros a temperatura ambiente y 1200 °C. Los resultados indican que la tenacidad se incrementó 110.4% para el geopolímero reforzado con fibras cerámicas (G-AF) a temperatura ambiente. La presencia de partículas mejora el comportamiento a la flexión 265% para el geopolímero reforzado con fibras de carbono y partículas después de la exposición a 1200 °C. La contracción lineal para el geopolímero reforzado con fibras cerámicas y partículas y el geopolímero G

  8. Proyecto de apertura de una Planta de Recolección de Fibras Secundarias en la zona norte de la República del Perú, Piura

    OpenAIRE

    Coellar Neira, Paulo Geovanny

    2005-01-01

    Fibras Secundarias. La utilización de fibras secundarias en la elaboración y producción de papel. La recuperación de fibras secundarias. El Mercado Ecuatoriano de Fibras Secundarias. Análisis de Mercado. Determinación del mercado potencial, comparación con países desarrollados. ¿Cómo potenciar el mercado nacional de recuperación de fibras?. Marco legal actual y deseado. Análisis y comentario. Fuentes alternativas de aprovisionamiento de fibras secundarias. Análisis del potencial mercado del P...

  9. Quantifying visual pathway axonal and myelin loss in multiple sclerosis and neuromyelitis optica.

    Science.gov (United States)

    Manogaran, Praveena; Vavasour, Irene M; Lange, Alex P; Zhao, Yinshan; McMullen, Katrina; Rauscher, Alexander; Carruthers, Robert; Li, David K B; Traboulsee, Anthony L; Kolind, Shannon H

    2016-01-01

    The optic nerve is frequently injured in multiple sclerosis and neuromyelitis optica, resulting in visual dysfunction, which may be reflected by measures distant from the site of injury. To determine how retinal nerve fiber layer as a measure of axonal health, and macular volume as a measure of neuronal health are related to changes in myelin water fraction in the optic radiations of multiple sclerosis and neuromyelitis optica participants with and without optic neuritis and compared to healthy controls. 12 healthy controls, 42 multiple sclerosis (16 with optic neuritis), and 10 neuromyelitis optica participants (8 with optic neuritis) were included in this study. Optical coherence tomography assessment involved measurements of the segmented macular layers (total macular, ganglion cell layer, inner plexiform layer, and inner nuclear layer volume) and paripapillary retinal nerve fiber layer thickness. The MRI protocol included a 32-echo T2-relaxation GRASE sequence. Average myelin water fraction values were calculated within the optic radiations as a measure of myelin density. Multiple sclerosis and neuromyelitis optica eyes with optic neuritis history had lower retinal nerve fiber layer thickness, total macular, ganglion cell and inner plexiform layer volumes compared to eyes without optic neuritis history and controls. Inner nuclear layer volume increased in multiple sclerosis with optic neuritis history (mean = 0.99 mm(3), SD = 0.06) compared to those without (mean = 0.97 mm(3), SD = 0.06; p = 0.003). Mean myelin water fraction in the optic radiations was significantly lower in demyelinating diseases (neuromyelitis optica: mean = 0.098, SD = 0.01, multiple sclerosis with optic neuritis history: mean = 0.096, SD = 0.01, multiple sclerosis without optic neuritis history: mean = 0.098, SD = 0.02; F3,55 = 3.35, p = 0.03) compared to controls. Positive correlations between MRI and optical coherence tomography measures were also apparent

  10. Hormigones de alta resistencia con nano-adiciones y fibras de acero

    OpenAIRE

    Alizo Mirabal, Manuel Arturo

    2015-01-01

    El presente Trabajo Fin de Máster consistió en determinar la influencia que pueden poseer las nano-adiciones de Sílice y Alúmina y fibras de acero en un Hormigón de Alta Resistencia. Partiendo de una dosificación de Hormigón de Alta Resistencia conocida, que contenía humo de Sílice (10%) y fibras de poliolefina (3kg/m3), se les procedió a sustituir por la incorporación de nano-adiciones de Sílice y Alúmina (7% y 3% respectivamente) y añadiendo fibras de acero en lugar de poliolefina. En el pr...

  11. CONCRETO REFORZADO CON FIBRA NATURAL DE ORIGEN ANIMAL (PLUMAS DE AVES)

    OpenAIRE

    Díaz Cabrejos, Pablo; Universidad Señor de Sipán SAC

    2016-01-01

    Para mejorar las propiedades del concreto como la resistencia y la durabilidad ha sido investigado a través de los años. Con ayuda de la tecnología se han obtenido óptimos diseños para concretos reforzados con fibras pero su aplicación comercial aún está limitada debido a que estas fibras incrementan el costo.Con la presente investigación se pretende determinar el contenido óptimo de las fibras en el concreto teniendo en cuenta la inhibición causadas por la contracción plástica. Se estudiará ...

  12. Caracterización de los compuestos del aroma en rones colombianos por HS-SPME-GC-MS-O

    Directory of Open Access Journals (Sweden)

    Jazmín Osorio Monsalve

    2016-11-01

    Full Text Available Se identificaron por primera vez 46 compuestos volátiles olfativamente activos con actividad aromática significativa presentes en rones comerciales de Colombia. Lo anterior, mediante microextracción en fase sólida en modo espacio de cabeza (HS-SPME, acoplada a cromatografía de gases con detectores de espectrometría de masas y olfatometría (GC-MS-O. Dentro de los compuestos identificados se encuentran ésteres, compuestos aromáticos, alcoholes, acetales, lactonas y furfural. De esos 46 compuestos, nueve están presentes en todos los rones estudiados y algunos otros son característicos solo de la marca.

  13. Estudio de viabilidad de cajones marítimos con hormigón con fibras

    OpenAIRE

    Ramos Marquès, Òscar Gonçal

    2017-01-01

    En este TFM se estudia la viabilidad de sustituir la armadura pasiva por fibras metálicas o plásticas en cajones para obras portuarias. Para ello, en primer lugar, se estudia el procedimiento constructivo de un cajón y las propiedades de los hormigones con fibras. Una vez analizado el estado del conocimiento se procede a escoger un cajón representativo, ya construido con armadura pasiva. El cajón escogido es el cajón tipo 3 del dique est...

  14. Sensores de fibra óptica basados en resonancias electromagnéticas

    OpenAIRE

    López Lambás, Sergio

    2011-01-01

    Este trabajo surge como continuación a los trabajos basados en LMR ya realizados con el objetivo de profundizar en el estudio y fabricación de sensores de fibra óptica basados en resonancias electromagnéticas utilizando diferentes materiales y técnicas. En concreto el proyecto perseguirá los siguientes objetivos: Desarrollar sensores de fibra óptica basados en resonancias electromagnéticas con recubrimientos metálicos y su aplicación a la detección de campo magnético. Estudiar y mejorar la fa...

  15. Reconstrucción de lesiones osteocondrales con fibra de carbono

    OpenAIRE

    Carranza Bencano, A.; Armas-Padrón, J. R.; Lozano, Mª A.

    1998-01-01

    Objetivo: Estudiar a largo plazo la evolución histológica de defectos osteocondrales de la rótula de conejos tratados con fibra de carbono. Material y Método: 18 conejos de raza gigante español, variedad parda, de ambos sexos, con un peso aproximado de 1.5 a 2 Kg y 18 discos Cleveland de fibra de carbono de 8 mm de diámetro (Medicarb®, fabricado por Leyland Medical International). Creación de un defecto de 6 mm. de diámetro en la superficie articular de la rótula, hasta alcanzar el teji...

  16. Caracterización de propiedades relacionadas con la textura de suspensiones de fibras alimentarias

    OpenAIRE

    CÓRDOBA SEQUEIRA, ARTURO

    2008-01-01

    La fibra dietética es un componente que, además de ser beneficioso para la salud, puede resultar adecuado para aumentar la viscosidad y otras propiedades relacionadas de determinados productos. No obstante, la procedencia de la misma, así como su concentración y el modo en que se adicione puede afectar a su funcionalidad. En este trabajo se ha realizado un estudio de las propiedades físico-químicas y estructurales de fibras dietéticas procedentes de diferentes frutas (limón, naranja y manzana...

  17. Desenvolvimento de sorvete de chocolate utilizando fibra de casca de laranja como substituto de gordura

    Directory of Open Access Journals (Sweden)

    Camila Comas e Boff

    2013-10-01

    Full Text Available A procura por alimentos mais saudáveis por parte dos consumidores tem impulsionado as indústrias de alimentos a desenvolverem alimentos que contenham menor teor de gordura, contudo sem alterar as características sensoriais e nutricionais dos produtos. A indústria de sorvetes é uma das que mais utiliza gordura em suas formulações, contendo, em média, 10% desse ingrediente. Uma alternativa para a substituição de gorduras é a fibra de frutas cítricas, que vem sendo utilizada com sucesso, reduzindo o teor de gordura na indústria de embutidos, por exemplo. Nesse sentido, o objetivo deste trabalho foi avaliar as características sensoriais e físico-químicas de sorvetes elaborados com fibra de casca de laranja amarga comercial como substituto da gordura. Foram utilizadas duas formulações com concentrações diferentes de fibra de laranja (F1 com 0,74% e F2 com 1,10% de fibra e uma formulação controle (com gordura. Para as duas formulações, foram encontrados valores condizentes com a literatura para a composição centesimal do sorvete. Em relação ao valor energético dos sorvetes, foi observada uma redução de mais de 25%, indicando que o produto pode ter alegação de light. Para o teor de fibra dos sorvetes, os valores observados foram de F1 1,4% e F2, 2,0%, podendo considerar o sorvete da formulação F2 como fonte de fibras. Os atributos de cor, odor e textura não apresentaram diferenças entre as amostras. Já sabor, sabor residual e aceitação global obtiveram diferenças entre as amostras com fibra e a controle. Os sorvetes elaborados com fibra de casca de laranja obtiveram índices de aceitação de 78%.

  18. Quantitative Susceptibility Mapping Indicates a Disturbed Brain Iron Homeostasis in Neuromyelitis Optica ? A Pilot Study

    OpenAIRE

    Doring, Thomas Martin; Granado, Vanessa; Rueda, Fernanda; Deistung, Andreas; Reichenbach, Juergen R.; Tukamoto, Gustavo; Gasparetto, Emerson Leandro; Schweser, Ferdinand

    2016-01-01

    Dysregulation of brain iron homeostasis is a hallmark of many neurodegenerative diseases and can be associated with oxidative stress. The objective of this study was to investigate brain iron in patients with Neuromyelitis Optica (NMO) using quantitative susceptibility mapping (QSM), a quantitative iron-sensitive MRI technique. 12 clinically confirmed NMO patients (6 female and 6 male; age 35.4y±14.2y) and 12 age- and sex-matched healthy controls (7 female and 5 male; age 33.9±11.3y) underwen...

  19. What do we know about brain contrast enhancement patterns in neuromyelitis optica?☆

    Science.gov (United States)

    Pekcevik, Yeliz; Orman, Gunes; Lee, In Ho; Mealy, Maureen A.; Levy, Michael; Izbudak, Izlem

    2016-01-01

    Neuromyelitis optica (NMO) is an autoimmune disorder of the central nervous system that usually presents with acute myelitis and/or optic neuritis. Recently, some brain magnetic resonance imaging findings have been described in NMO that are important in the differential diagnosis. Pencil-thin, leptomeningeal, and cloud-like enhancement may be specific to NMO. These patterns are usually seen during relapses. Recognizing these lesions and enhancement patterns may expedite the diagnosis and allows early effective treatment. The purpose of this article is to review the latest knowledge and to share our experience with the contrast enhancement patterns of NMO brain lesions. PMID:26615899

  20. Comparison of the efficacy of azathioprine and rituximab in neuromyelitis optica spectrum disorder

    DEFF Research Database (Denmark)

    Nikoo, Zahra; Badihian, Shervin; Shaygannejad, Vahid

    2017-01-01

    Neuromyelitis optica spectrum disorder (NMOSD) often follows a relapsing course. As disability in NMOSD is attack-related, effective treatments are needed. We aimed to compare the efficacy of azathioprine (AZA) and rituximab (RIT) as maintenance therapy in NMOSD patients. An open, randomized...... = 0–7). Patients were randomized into two groups, which did not differ according to age, gender distribution, and disease duration. In the AZA group, 35 patients [20 aquaporin-4 (AQP4)-IgG positive] were started on 50 mg/day oral AZA and increased to 2–3 mg/kg/day (with oral prednisolone as adjunctive...

  1. Pulmonary tuberculosis with neuromyelitis optica: an uncommon association of a common disease

    International Nuclear Information System (INIS)

    Siddiqi, S.A.; Hashmi, M.; Azmat, Z.; Mustafa, S.; Siddiqui, K.A.

    2012-01-01

    Systemic tuberculosis has been reported with varying neurological manifestations like meningitis, tuberculomas, myositis and neuropathy. Neuromyelitis optica (NMO) is a well known neurological entity which has been described in association with several systemic disorders like systemic lupus erythematosis, diabetes mellitus, hypothyroidism, exposure to Mycobacterium tuberculosis. insecticides etc. However, only a few cases of NMO have been reported in association with Here, we report a case of pulmonary tuberculosis in association with NMO to highlight the under-reported association of NMO with pulmonary tuberculosis presenting in a peculiar anatomical fashion i.e. longitudinal myelitis with predominant posterior column involvement. (author)

  2. Convergence spasm due to aquaporin-positive neuromyelitis optica spectrum disorder

    Directory of Open Access Journals (Sweden)

    Pınar Özçelik

    2017-06-01

    Full Text Available A female 27 presented with nausea and diplopia for 1 week. On examination she had normal vertical gaze but would develop convergence with miosis whenever she made horizontal saccades. Pupils were 6 mm and unreactive to light. MRI showed extensive hyperintensity in the dorsal midbrain and thalamus. Spinal MRI and CSF were both normal. Serum aquaporin-4-antibody was positive. She was treated with steroids and plasmapheresis and after 3 months convergence spasm resolved but pupils remained unreactive. Neuromyelitis optica often presents with brainstem signs, rarely a dorsal midbrain syndrome. Convergence spasm is occasionally of organic neurologic origin.

  3. Change in autoantibody and cytokine responses during the evolution of neuromyelitis optica in patients with systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Kovacs, Katalin T; Kalluri, Sudhakar Reddy; Boza-Serrano, Antonio

    2016-01-01

    BACKGROUND: Neuromyelitis optica (NMO)-systemic lupus erythematosus (SLE) association is a rare condition characterized by multiple autoantibodies. OBJECTIVE: To examine if, during the evolution of NMO, anti-AQP4 responses are part of polyclonal B cell activation, and if T cell responses contribute...

  4. A systematic analysis of the complement pathways in patients with neuromyelitis optica indicates alteration but no activation during remission

    DEFF Research Database (Denmark)

    Veszeli, Nóra; Füst, György; Csuka, Dorottya

    2014-01-01

    Neuromyelitis optica (NMO) is an autoimmune demyelinating inflammatory disorder, mediated by pathogenic autoantibodies against aquaporin 4 (AQP4), the main water channel of the central nervous system (CNS). NMO is characterized by local IgG deposition and complement activation within the CNS...

  5. Sudden onset of sleep due to hypothalamic lesions in neuromyelitis optica spectrum disorder positive for anti-aquaporin-4 antibody.

    Science.gov (United States)

    Okuma, H; Matsumura, K; Hatanaka, Y; Saito, F; Sonoo, M

    2014-09-01

    We report a patient with neuromyelitis optica spectrum disorders who presented with sudden onset of sleep as the sole manifestation. Magnetic resonance imaging investigation revealed lesions in the hypothalamus bilaterally, which vanished completely after methylprednisolone pulse therapy. © The Author(s) 2014.

  6. Estudo de propriedades estruturais e opticas de multicamadas epitaxiais emissoras de luz baseadas em InGaN/GaN

    Science.gov (United States)

    Pereira, Sergio Manuel de Sousa

    Esta tese apresenta os resultados de uma investigacao experimental em filmes epitaxiais emissores de luz baseados em InxGa1-xN. O InxGa1-xN e uma liga semicondutora ternaria do grupo III-N muito utilizada como camada activa numa gama de dispositivos optoelectronicos em desenvolvimento, incluindo diodos emissores de luz (LEDs) e diodos laser (LDs), para operacao na regiao do visivel e ultravioleta do espectro electromagnetico. Neste estudo, caracterizam-se as propriedade opticas e estruturais de camadas simples e pocos quânticos multiplos (Multiple Quantum Wells, MQWs) de InxGa1-xN/GaN, com enfase nas suas propriedades fisicas fundamentais. O objectivo central do trabalho prende-se com a compreensao mais profunda dos processos fisicos que estao por tras das suas propriedades opticas, preenchendo o fosso existente entre aplicacoes tecnologicas e o conhecimento cientifico. Nomeadamente, a tese aborda os problemas da medicao da fraccao de InN (x) em multicamadas ultrafinas sujeitas a tensoes, a influencia da composicao e das tensoes microscopicas nas propriedades opticas e estruturais. A questao relativa a segregacao de fases em multicamadas de InxGa1-xN/GaN e tambem discutida a luz dos resultados obtidos. A metodologia seguida assenta na integracao de resultados obtidos por tecnicas complementares atraves de uma analise sistematica e multidisciplinar. Esta abordagem passa pela combinacao de: 1) Crescimento de amostras por deposicao epitaxial em fase de vapor organometalico (MOVPE) com caracteristicas especificas de forma a tentar isolar parâmetros estruturais, tais como espessura e composicao; 2) Caracterizacao nanoestrutural por microscopia de forca atomica (AFM), microscopica electronica de varrimento (SEM), difraccao de raios-X e retro-dispersao de Rutherford (RBS); 3) Caracterizacao optica a escalas complementares por: espectroscopia de absorcao optica (OA), fotoluminescencia (PL), catodoluminescencia (CL) e microscopia confocal (CM) com analise espectral. Com

  7. Influence of female sex and fertile age on neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Borisow, Nadja; Kleiter, Ingo; Gahlen, Anna; Fischer, Katrin; Wernecke, Klaus-Dieter; Pache, Florence; Ruprecht, Klemens; Havla, Joachim; Krumbholz, Markus; Kümpfel, Tania; Aktas, Orhan; Ringelstein, Marius; Geis, Christian; Kleinschnitz, Christoph; Berthele, Achim; Hemmer, Bernhard; Angstwurm, Klemens; Weissert, Robert; Stellmann, Jan-Patrick; Schuster, Simon; Stangel, Martin; Lauda, Florian; Tumani, Hayrettin; Mayer, Christoph; Zeltner, Lena; Ziemann, Ulf; Linker, Ralf A; Schwab, Matthias; Marziniak, Martin; Then Bergh, Florian; Hofstadt-van Oy, Ulrich; Neuhaus, Oliver; Winkelmann, Alexander; Marouf, Wael; Rückriem, Lioba; Faiss, Jürgen; Wildemann, Brigitte; Paul, Friedemann; Jarius, Sven; Trebst, Corinna; Hellwig, Kerstin

    2017-07-01

    Gender and age at onset are important epidemiological factors influencing prevalence, clinical presentation, and treatment response in autoimmune diseases. To evaluate the impact of female sex and fertile age on aquaporin-4-antibody (AQP4-ab) status, attack localization, and response to attack treatment in patients with neuromyelitis optica (NMO) and its spectrum disorders (neuromyelitis optica spectrum disorder (NMOSD)). Female-to-male ratios, diagnosis at last visit (NMO vs NMOSD), attack localization, attack treatment, and outcome were compared according to sex and age at disease or attack onset. A total of 186 NMO/SD patients (82% female) were included. In AQP4-ab-positive patients, female predominance was most pronounced during fertile age (female-to-male ratio 23:1). Female patients were more likely to be positive for AQP4-abs (92% vs 55%; p 40 years. Our data suggest an influence of sex and age on susceptibility to AQP4-ab-positive NMO/SD. Genetic and hormonal factors might contribute to pathophysiology of NMO/SD.

  8. Higher frequency of brain abnormalities in neuromyelitis optica spectrum disorder patients without primary Sjögren's syndrome.

    Science.gov (United States)

    Gu, Li-Na; Zhang, Min; Zhu, Hui; Liu, Jing-Yao

    2016-10-01

    Neuromyelitis optica spectrum disorder often co-exists with primary Sjögren's syndrome. We compared the clinical features of 16 neuromyelitis optica spectrum disorder patients with ( n = 6) or without primary Sjögren's syndrome ( n = 10). All patients underwent extensive clinical, laboratory, and MRI evaluations. There were no statistical differences in demographics or first neurological involvement at onset between neuromyelitis optica spectrum disorder patients with and without primary Sjögren's syndrome. The laboratory findings of cerebrospinal fluid oligoclonal banding, serum C-reactive protein, antinuclear autoantibody, anti-Sjögren's-syndrome-related antigen A antibodies, anti-Sjögren's-syndrome-related antigen B antibodies, and anti-Sm antibodies were significantly higher in patients with primary Sjögren's syndrome than those without. Anti-aquaporin 4 antibodies were detectable in 67% (4/6) of patients with primary Sjögren's syndrome and in 60% (6/10) of patients without primary Sjögren's syndrome. More brain abnormalities were observed in patients without primary Sjögren's syndrome than in those with primary Sjögren's syndrome. Segments lesions (> 3 centrum) were noted in 50% (5/10) of patients without primary Sjögren's syndrome and in 67% (4/6) of patients with primary Sjögren's syndrome. These findings indicate that the clinical characteristics of neuromyelitis optica spectrum disorder patients with and without primary Sjögren's syndrome are similar. However, neuromyelitis optica spectrum disorder patients without primary Sjögren's syndrome have a high frequency of brain abnormalities.

  9. Protective effect of an elastase inhibitor in a neuromyelitis optica-like disease driven by a peptide of myelin oligodendroglial glycoprotein.

    NARCIS (Netherlands)

    Herges, K.; Jong, B.A. de; Kolkowitz, I.; Dunn, C.; Mandelbaum, G.; Ko, R.M.; Maini, A.; Han, M.H.; Killestein, J.; Polman, C.; Goodyear, A.L.; Dunn, J.; Steinman, L.; Axtell, R.C.

    2012-01-01

    BACKGROUND: The pathology of neuromyelitis optica (NMO), in contrast to multiple sclerosis, comprises granulocyte infiltrates along extensive lengths of spinal cord, as well as optic nerve. Furthermore, IFN-beta treatment worsens NMO. We recently found that experimental autoimmune encephalomyelitis

  10. Fibra de sisal como envoltório na drenagem agrícola

    Directory of Open Access Journals (Sweden)

    Viviane F. Silva

    2014-06-01

    Full Text Available O trabalho foi realizado objetivando analisar o desempenho do sistema de drenagem com fibra de sisal envolto orgânico como material alternativo.  A pesquisa foi realizada no Laboratório de Engenharia de Irrigação e Drenagem da Universidade Federal de Campina Grande. Usando-se um sistema experimental composto de nove tanques construídos de alvenaria e impermeabilizados internamente. Os tratamentos foram dispostos em um arranjo fatorial com três tipos de tubos, Drenoflex, Kananet e tubo de PVC liso próprio para Esgoto envolto com fibra de sisal num delineamento inteiramente casualizado com três repetições. Foram avaliados a carga hidráulica de entrada (he, fluxo(q e resistência de entrada(re e analisados  estatisticamente, utilizando-se o software ASSISTAT . A comparação dos tubos Drenoflex, PVC liso e Kananet envolto com fibra de sisal, as médias da carga hidráulica na entrada para os tubos variando os valores de 0,40486 a 0,35543, sendo significativo para o tubo Kananet, devido possuir furos maiores facilitando assim a passagem da água pelo tubo. E em relação à resistência de entrada na interação entre os tubos drenantes e a fibra de sisal diferiu estatisticamente com o tubo PVC liso. O desempenho do sistema drenante com envolto de fibra de sisal é considerado muito bom.

  11. OBTENCIÓN DE FIBRA DIETETICA NUTRICIONAL DE VALOR AGREGADO A PARTIR DE BAGAZO DE CAÑA

    OpenAIRE

    LICONA AGUILAR, ANGELES IVETH

    2014-01-01

    La fibra dietética se reconoce cada vez más como un elemento importante para una nutrición sana; numerosas referencias respaldan esta aseveración en las que se ha demostrado no solo la importancia que la fibra tiene en la regulación de las funciones intestinales sino también para la prevención de algunas enfermedades. En este contexto, tiene sentido analizar la posibilidad de aprovechar la potencial utilización que brindan numerosos residuos agrícolas como fuente de fibra en una gran variedad...

  12. Severe optic neuritis in a patient with combined neuromyelitis optica spectrum disease and primary Sjögren’s syndrome: a case report

    Directory of Open Access Journals (Sweden)

    Tan Petrina

    2012-11-01

    Full Text Available Abstract Introduction Optic neuritis, although uncommon, can be the initial presentation of Sjögren’s syndrome. Coexisting Sjögren’s syndrome has also been reported with neuromyelitis optica spectrum disorder. This case report highlights the association between the two diseases and the importance of rheumatological and neurological evaluations in patients with such diagnoses. Distinction of neuromyelitis optica with coexisting connective tissue disease has both prognostic and therapeutic significance for the patient. Case presentation We report a case of a 56-year-old Chinese woman who presented with bilateral asymmetric visual loss secondary to optic neuritis. She was subsequently found to be seropositive for neuromyelitis optica immunoglobulin G (NMO-IgG (anti-aquaporin-4 antibody and was diagnosed with neuromyelitis optica spectrum disorder. She also fulfilled the international criteria for Sjögren’s syndrome. Despite initial high dose immunosuppressive therapy, she failed to regain vision in one eye. Conclusion Patients presenting with optic neuritis and severe visual loss should be screened for neuromyelitis optica and treated appropriately. Neuromyelitis optica has been associated with systemic autoimmune diseases, in particular Sjögren’s syndrome, and current evidence indicates that they are two distinct entities. We recommend that both diagnoses be considered in cases of optic neuritis with severe visual loss.

  13. Modelos de elementos finitos de componentes de autobuses fabricados en materiales compuestos

    OpenAIRE

    Grimaldi Pastoril, Rocío; Alcalá Fazio, Enrique

    2010-01-01

    La creciente preocupación por la seguridad en el transporte de pasajeros, ha hecho que las estructuras de los autobuses y autocares se vean sometidas a solicitaciones cada vez más exigentes, sobre todo ante condiciones de vuelco cuyos requerimientos vienen determinados por el Reglamento 66 de ginebra. Es por eso que en esta ponencia se pretende presentar una alternativa de pilares de estructura con materiales compuestos para el uso de los mismos como método reductor de masa de los vehícu...

  14. Extracción de compuestos aromáticos con furfural en aceites lubricantes recuperados

    OpenAIRE

    Meléndez Hernández, Marianna Andrea

    2015-01-01

    Se presenta un estudio experimental y diseño conceptual con especificación de equipos y análisis económico de un proceso de extracción con furfural de compuestos aromáticos presentes en la base lubricante recuperada, para su decoloración y desodorización, después del proceso de regeneración de aceites usados en la empresa Biochemical Group -- Se realiza un diseño de experimentos factorial 32 para evaluar el proceso determinando la composición de hidrocarburos aromáticos en el extracto y refin...

  15. COMPUESTOS DE HIERRO PARA SUPLEMENTACIÓN ORAL: PRINCIPIOS Y AVANCES -REVISIÓN SISTEMATICA

    OpenAIRE

    PEREZ M, Lina J.; TOBÓN, Gloria

    2006-01-01

    Se presenta una revisión que abarca los principales aspectos sobre la absorción oral del hierro (fuentes y captación) y sus funciones en el organismo, centrándose en la tendencia actual de utilizar complejos o quelatos de este metal con ligandos orgánicos para el tratamiento oral por deficiencia del mismo (monosacáridos, aminoácidos y ácidos carboxílicos de bajo peso molecular), ya que estos compuestos aumentan la biodisponibilidad del hierro y disminuyen los efectos adversos que presentan su...

  16. Modelización de impactos de material compuesto contra célula de carga

    OpenAIRE

    López Toledo, Álvaro

    2015-01-01

    En el presente trabajo fin de grado se han desarrollado dos modelos numéricos correspondientes a un modelo completo y otro simplificado donde se hace impactar lajas de material compuesto de dimensiones 81x42 mm2 y 2.4 mm de espesor y de secuencia de laminado (+45/-45/0/90/90/0)s. Este material está formado por doce láminas y se recrea de varias formas, introduciendo diferente cantidad de elementos cohesivos, en concreto de cero, uno y tres. Para ambos modelos se utilizan velocidades de lanzam...

  17. Caracterización del material compuesto mármol-poliéster

    OpenAIRE

    Corpas Iglesias, F. A.; Iglesias Godino, F. J.; Codina Sánchez, S.; Ruiz Román, J. M.; Ruiz Prieto, J. M.; Alonso Santos, C.

    2002-01-01

    En este trabajo, caracterizamos un nuevo material compuesto, formado con una mezcla de poliéster y de mármol blanco triturado. El propósito final es doble: por un lado obtener un material para aplicaciones lo suficientemente competitivas como para que se pueda iniciar un estudio económico de viabilidad, aumentando el rendimiento de la materia prima y mejorando las salidas laborales de las comarcas extractoras. Para la caracterización del material se ha determinado el porcentaje adecuado de...

  18. El Nopal fresco como fuente de fibra y calcio en panqués El Nopal fresco como fuente de fibra y calcio en panqués

    OpenAIRE

    José Eleazar Barboza- Corona; Victor Manuel Da Mota; Ernesto Camarena-Aguilar; Guadalupe Alanís- Guzmán; Rosa Inés Pineda Torres; Mayela Bautista-Justo

    2012-01-01

    El objetivo de este trabajo fue utilizar nopal fresco en la formulación de panqués para incrementar su contenido de fibra dietética y calcio. Se desarrollaron cinco formulaciones de panqués utilizando nopal fresco (Opuntia amyclaea Tenore), 4 con sucralosa (una testigo sin nopal) y una con azúcar y nopal. Se evaluaron sensorialmente por 60 jueces no entrenados mediante la prueba de preferencia, utilizando una escala hedónica del 1 al 9. Se les determinó el contenido de proteína (Nx6.25), hume...

  19. Anti-N-methyl-d-aspartate receptor encephalitis in a patient with neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Luo, Jing-Jing; Lv, He; Sun, Wei; Zhao, Juan; Hao, Hong-Jun; Gao, Feng; Huang, Yi-Ning

    2016-07-01

    We described a female patient with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis occurring sequentially with neuromyelitis optica spectrum disorders (NMOSD). The 19-year-old patient initially presented a diencephalic syndrome with aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) and brain lesions which involving bilateral medial temporal lobes and periependymal surfaces of the third ventricle on magnetic resonance imaging (MRI). Ten months later, the patient developed cognitive impairment, psychiatric symptoms and dyskinesia with left basal ganglia lesions on brain MRI. Meanwhile, the anti-NMDAR antibodies were positive in the patient's serum and cerebrospinal fluid, while the screening tests for an ovarian teratoma and other tumors were all negative. Hence, the patient was diagnosed NMOSD and anti-NMDAR encephalitis followed by low-dose rituximab treatment with a good response. This case was another evidence for demyelinating syndromes overlapping anti-NMDAR encephalitis in Chinese patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Seronegative Neuromyelitis Optica Spectrum - The challenges on disease definition and pathogenesis

    Directory of Open Access Journals (Sweden)

    Douglas Kazutoshi Sato

    2014-06-01

    Full Text Available Neuromyelitis optica spectrum disorders (NMOSD are characterized by severe optic neuritis and/or longitudinally extensive transverse myelitis, and some brain lesions are also unique to NMOSD. Serum autoantibodies against aquaporin-4 (AQP4 are detected in most cases of NMOSD. However, some patients with NMOSD remain seronegative despite repetitive testing during attacks with highly sensitive cell-based assays. The differential diagnosis of NMOSD is not restricted to multiple sclerosis and it includes many diseases that can produce longitudinally extensive myelitis and/or optic neuritis. We review the clinical features, imaging, and laboratory findings that can be helpful on the diagnostic work-up, discuss the differences between AQP4 antibody positive and negative patients with NMOSD, including features of NMOSD with antibodies against myelin oligodendrocyte glycoprotein.

  1. Contribution of spinal cord biopsy to diagnosis of aquaporin-4 antibody positive neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Ringelstein, M; Metz, I; Ruprecht, K; Koch, A; Rappold, J; Ingwersen, J; Mathys, C; Jarius, S; Brück, W; Hartung, H-P; Paul, F; Aktas, O

    2014-06-01

    Longitudinally extensive transverse myelitis is characteristic but not pathognomonic for neuromyelitis optica spectrum disorders (NMOSDs) and may mimic local tumors. In this retrospective study based on a cohort of 175 NMOSD patients we identified seven patients who initially presented with a longitudinally extensive spinal cord lesion and underwent spinal cord biopsy due to magnetic resonance imaging (MRI)-suspected malignancies. Remarkably, routine neuropathology was inconclusive and did not guide the diagnostic process to anti-aquaporin-4 (AQP4)-seropositive NMOSD. Serious postoperative complications occurred in 5/7 patients and persisted during follow-up in 2/7 patients (29%). Considering these sequelae, AQP4-antibody testing should be mandatory in patients with inconclusive longitudinally extensive spinal cord lesions prior to biopsy. © The Author(s) 2013.

  2. Monoclonal antibody therapy for neuromyelitis optica spectrum disorder: current and future.

    Science.gov (United States)

    Lin, Jie; Xue, Binbin; Li, Xiang; Xia, Junhui

    2017-08-01

    Monoclonal-antibody has been used for patients with autoimmune disorders for several years, and efficacy and safety were appreciated for these patients. Neuromyelitis optica specturm disorder (NMOSD) has been defined as an autoimmune demyelination disorder of the central nervous system (CNS) with a course of relapse-remission. Treatment of prevention is important for patients with NMOSD because of the increased disability after several attacks. Multiple factors were involved in the pathogenesis of NMOSD. Currently, targeting specific factor was favored in the research into the treatment for NMOSD. Previous studies reported the efficacy and tolerance in NMOSD for drugs such as rituximab, tocilizumab, and eculizumab. The aim of this article is to review the current monoclonal therapies for NMOSD patients, and also future alternative options.

  3. Combination Treatment of C16 Peptide and Angiopoietin-1 Alleviates Neuromyelitis Optica in an Experimental Model

    Directory of Open Access Journals (Sweden)

    Yuanyuan Zhang

    2018-01-01

    Full Text Available Neuromyelitis optica (NMO is an autoimmune inflammatory demyelinating disease that mainly affects the spinal cord and optic nerve, causing blindness and paralysis in some individuals. Moreover, NMO may cause secondary complement-dependent cytotoxicity (CDC, leading to oligodendrocyte and neuronal damage. In this study, a rodent NMO model, showing typical NMO pathogenesis, was induced with NMO-IgG from patient serum and human complement. We then tested whether the combination of C16, an αvβ3 integrin-binding peptide, and angiopoietin-1 (Ang1, a member of the endothelial growth factor family, could alleviate NMO in the model. Our results demonstrated that this combination therapy significantly decreased disease severity, inflammatory cell infiltration, secondary demyelination, and axonal loss, thus reducing neural death. In conclusion, our study suggests a possible treatment that can relieve progressive blindness and paralysis in an animal model of NMO through improvement of the inflammatory milieu.

  4. Depressive state and chronic fatigue in multiple sclerosis and neuromyelitis optica.

    Science.gov (United States)

    Akaishi, Tetsuya; Nakashima, Ichiro; Misu, Tatsuro; Fujihara, Kazuo; Aoki, Masashi

    2015-06-15

    Depression and chronic fatigue are frequently present in multiple sclerosis (MS); however, the prevalence rates have not been investigated in neuromyelitis optica (NMO). Thirty-nine consecutive NMO and 75 MS patients were compared using self-rating questionnaires for depressive states, daily activity, and fatigue, as well as serum carnitine levels. A subgroup of patients with low carnitine levels were re-evaluated regarding depression and fatigue after levocarnitine treatment. Depression and fatigue were equally prevalent in MS and NMO and were strongly correlated with one another. Measurement of the serum carnitine levels and the administration of levocarnitine did not appear to be beneficial. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Anti-C1q autoantibodies in patients with neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Yoshikura, Nobuaki; Kimura, Akio; Hayashi, Yuichi; Inuzuka, Takashi

    2017-09-15

    We examined anti-complement C1q (C1q) autoantibody levels in serum and cerebrospinal fluid (CSF) samples of patients with neuromyelitis optica spectrum disorders (NMOSD). We analyzed the correlations between anti-C1q autoantibody levels and the clinical and other CSF characteristics of NMOSD. Serum and CSF anti-C1q autoantibody levels increased during the acute phase of NMOSD, reverting to the same levels as controls during remission. CSF anti-C1q autoantibody levels during the acute phase correlated with several markers reflecting disease severity, Expanded Disability Status Scale worsening, spinal cord lesion length in cases with myelitis, CSF protein and interleukin-6 levels, and CSF/serum albumin ratios. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Clinical analysis of neuromyelitis optica presenting as intractable nausea, vomiting and hiccups.

    Science.gov (United States)

    Jin, Xuehong; Pei, Shaofang; Liu, Yi; Li, Xia

    2017-10-01

    Vomiting and hiccups can be the manifestations of numerous systemic and neurological illnesses. Intractable nausea, vomiting and hiccups (INH) are reported as possible initial manifestations of neuromyelitis optica (NMO), but not correctly identified. Awareness of these atypical presentations is conducive to NMO early diagnosis and proper treatment to prevent further disability. In this paper, 12 NMO were reported, whose intractable vomiting and hiccups were the sole manifestations of the first attack and other attacks involving spinal cord and optic nerves developed later. All the patients were women and serum aquaporin 4 antibody (AQP4-Ab) of 83% patients was positive. MRI of 50% patients showed T2-weighted imaging/fluid attenuated inversion recovery hyperintensity which were longitudinally extensive transverse myelitis or linear signal changes. Sixty-seven percent of patients had medulla lesions, in which dorsomedial and area postrema were involved.

  7. Posterior reversible encephalopathy syndrome masquerading as progressive multifocal leukoencephalopathy in rituximab treated neuromyelitis optica.

    Science.gov (United States)

    Berger, Joseph R; Neltner, Janna; Smith, Charles; Cambi, Franca

    2014-11-01

    Both progressive multifocal leukoencephalopathy (PML) and posterior reversible encephalopathy syndrome (PRES) have been reported as complications of rituximab therapy. These disorders may appear indistinguishable on magnetic resonance imaging (MRI). We report on a 42 year old woman with neuromyelitis optica (NMO) of 10 years duration who developed extensive white matter disease affecting chiefly both parietal lobes 6 months after her first and only dose of rituximab. The MRI findings suggested the diagnosis of PML, but her history was more consistent with PRES. Ultimately, a brain biopsy was performed which was consistent with the diagnosis of PRES. PRES and PML may have overlapping symptomatology and be indistinguishable on MRI. An approach to distinguishing between these two disorders is addressed. Copyright © 2014. Published by Elsevier B.V.

  8. Use of Advanced Magnetic Resonance Imaging Techniques in Neuromyelitis Optica Spectrum Disorder

    DEFF Research Database (Denmark)

    Kremer, S.; Renard, F.; Achard, S.

    2015-01-01

    Brain parenchymal lesions are frequently observed on conventional magnetic resonance imaging (MRI) scans of patients with neuromyelitis optica (NMO) spectrum disorder but the specific morphological and temporal patterns distinguishing them uneqtaivcally from lesions caused by other disorders have...... not been identified. This literature review summarizes the literature on advanced quantitative imaging measures reported for patients with NMO spectrum disorder, including proton MR spectroscopy, diffusion tensor imaging, magnetization transfer imaging, quantitative MR voltametry, and ultrahigh...... diffusion-weighted imaging and brain tissue volumetry indicate greater white matter than gray matter degradation. These findings could be confirmed by ultrahigh-field MRI. The use of nonconventional MR I techniques may further our understanding of the pathogenic processes hi NMO spectrum disorders and may...

  9. Neuromyelitis optica in pregnancy complicated by posterior reversible encephalopathy syndrome, eclampsia and fetal death.

    Science.gov (United States)

    Igel, Catherine; Garretto, Diana; Robbins, Matthew S; Swerdlow, Michael; Judge, Nancy; Dayal, Ashlesha

    2015-03-01

    Neuromyelitis optica (NMO) is a demyelinating syndrome characterized by optic neuritis and acute myelitis with poor recovery and a progressive course. We report a poor outcome complicated by posterior reversible encephalopathy syndrome (PRES) and eclampsia and review available literature and current evidence for anticipation of adverse fetal and maternal effects. After a pregnancy complicated by multiple admissions for painful NMO exacerbations, a primiparous patient with seropositive NMO presented at 31 + 3/7 weeks with eclampsia, HELLP and subsequent fetal death. MRI confirmed PRES. NMO may be associated with eclampsia and leads to adverse maternal and fetal outcomes. Posited mechanisms include antibody-mediated placental damage and a heightened risk of eclampsia-associated PRES. Further characterization of the course of NMO and its relationship with pregnancy outcomes in larger series would be invaluable.

  10. Neuromyelitis optica spectrum disorder in patient with systemic lupus erythematosus - our experience

    Directory of Open Access Journals (Sweden)

    Božić Ksenija

    2018-01-01

    Full Text Available Introduction. Neuromyelitis optica spectrum disorder (NMOSD is a rare demyelinating immune-mediated central nervous system disease. It is extremely rare to occur in patients with systemic lupus erythematosus (SLE, and it represents a diagnostic and therapeutic challenge. Case report. A 38-year-old Caucasian woman with medical history of SLE and new onset of flaccid paraparesis, fecal and urinary incontinence, persistent nausea and vomiting was admitted to our hospital. Based on the clinical presentation, magnetic resonance imaging findings and positive aquaporin 4 (AQP4 antibodies, a NMOSD with coexisting SLE were diagnosed. Pulse-doses of cyclophosphamide and glucocorticoids were efficient in patient treatment. Conclusion. In a patient with SLE and symptoms of longitudinal extensive transverse myelitis and/or optic neuritis and area postrema syndrome, assessment of AQP4 antibodies is neccessary for diagnosing NMOSD. Accurate diagnosis, and timely and long-term administration of immunosuppressive therapy are crucial for favorable outcome of these two coexisting diseases.

  11. Presentation of Neuromyelitis Optica with Recurrent Severe Myelitis and Acute Respiratory Failure in an Old Woman

    Directory of Open Access Journals (Sweden)

    Saeed Razmeh

    2017-06-01

    Full Text Available Neuromyelitis Optica (NMO is a rare disease of the central nervous system that causes optic nerve and spinal cord involvement. The our patient first developed acute paraplegia that was treated with intravenous methylprednisolone with diagnosis of acute thoracic myelitis according to magnetic resonance imaging (MRI finding , concurrently with tapering of oral prednisolone, again affected by quadriplegia and respiratory failure. She was seropositivity for NMO-IgG that was negative in first admission and MRI of spine shows hyperintense lesion in whole cervical and upper thoracic MRI. With considering the findings, NMO was diagnosed and the plasmapheresis starts for her. We report a case of this syndrome because it can increase the physician’s awareness of the unusual manifestations of this syndrome.

  12. Endocrinopathies in paediatric-onset neuromyelitis optica spectrum disorder with aquaporin 4 (AQP4) antibody.

    Science.gov (United States)

    Hacohen, Yael; Messina, Silvia; Gan, Hoong-Wei; Wright, Sukhvir; Chandratre, Saleel; Leite, Maria Isabel; Fallon, Penny; Vincent, Angela; Ciccarelli, Olga; Wassmer, Evangeline; Lim, Ming; Palace, Jacqueline; Hemingway, Cheryl

    2018-04-01

    The involvement of the diencephalic regions in neuromyelitis optica spectrum disorder (NMOSD) may lead to endocrinopathies. In this study, we identified the following endocrinopathies in 60% (15/25) of young people with paediatric-onset aquaporin 4-Antibody (AQP4-Ab) NMOSD: morbid obesity ( n = 8), hyperinsulinaemia ( n = 5), hyperandrogenism ( n = 5), amenorrhoea ( n = 5), hyponatraemia ( n = 4), short stature ( n = 3) and central hypothyroidism ( n = 2) irrespective of hypothalamic lesions. Morbid obesity was seen in 88% (7/8) of children of Caribbean origin. As endocrinopathies were prevalent in the majority of paediatric-onset AQP4-Ab NMOSD, endocrine surveillance and in particular early aggressive weight management is required for patients with AQP4-Ab NMOSD.

  13. Catálogo de Radio-Fuentes Opticas con Astrolabio Fotoeléctrico PAII

    Science.gov (United States)

    Manrique, W. T.; Podestá, R. C.; Alonso, E.; Actis, E. V.; Pacheco, A. M.; Bustos, G.; Lizhi, L.; Zezhi, W.; Fanmiao, Z.; Hongqi, W.; Perdomo, R.

    Usando los datos observados en San Juan con el Astrolabio Fotoeléctrico PAII desde Febrero de 1992 hasta Marzo de 1997, se ha realizado el Catálogo de Radio-Fuentes Opticas de San Juan conteniendo 69 estrellas. Las observaciones de las posiciones de las radio-fuentes están realizadas para la época y equinoccio J2000,0 y en un sistema cercano al del FK5. Las precisiones medias son ± 2,2 ms y ± 0,"035 en ascensión recta y declinación respectivamente. Las magnitudes de las estrellas son desde 0,9 a 10,7 . Las declinaciones son desde --2,5 grados a --60 grados. La época media es 1995,1. Se muestran también los resultados comparados con el Catálogo Hiparcos.

  14. Uso de fibra natural de sisal em blocos de concreto para alvenaria estrutural

    OpenAIRE

    Indara Soto Izquierdo

    2011-01-01

    A utilização de fibras vegetais como reforço constitui um grande interesse na obtenção de novos materiais para a construção civil produto de seu baixo custo, alta disponibilidade e reduzido consumo de energia para sua produção. Este trabalho avalia a incorporação de fibras de sisal, de comprimento 20 e 40 mm, e fração volumétrica de 0,5 e 1%, em concretos para a alvenaria de blocos estruturais e determina o uso destas unidades na execução de prismas e mini-paredes. Foram realizados os testes ...

  15. Perfis de polietileno reciclado carregado com fibra de açaí

    OpenAIRE

    BRITO, Paulo Roberto de Oliveira

    2012-01-01

    Foram obtidos perfis tubulares porosos de polietileno (PE) e de polietileno/fibra de açaí (PE/PA) 80/20 extrudados a partir de partículas granuladas de polietileno de alta densidade reciclado de embalagens pós-consumo de 600 μm, e deste com fibra de açaí de 300 μm. Para o processamento das peças foi desenvolvida uma extrusora mono-rosca de bancada, com sistema mecânico acionado por um motor elétrico de ½ CV (0,37 kw) controlado por um inversor de freqüência, com canhões, roscas, matriz e sist...

  16. Vibrómetro de fibra óptica codificado en frecuencia

    OpenAIRE

    Sánchez Prudencio, Guillermo

    2013-01-01

    En el presente proyecto se expone el desarrollo de un vibrómetro basado en fibra óptica. La motivación de este proyecto es el diseño de un sistema capaz de monitorizar las vibraciones de una máquina mediante el uso de tecnología láser y de fibra óptica. Mediante este sistema es posible el cálculo de la frecuencia y amplitud de la vibración de la máquina. El vibrómetro está basado en el principio de interferencia de la luz. Un haz de luz coherente proporcionado por un láser se divide en dos: u...

  17. Bebidas a base de frutas procesadas por tecnologías no térmicas: compuestos bioactivos y bioaccesibilidad

    OpenAIRE

    Carbonell Capella, Juana Mª

    2016-01-01

    La presente tesis doctoral se centró en el análisis de compuestos bioactivos y parámetros de calidad en bebidas a base de zumos de frutas y sus modificaciones tras el procesado por tecnologías no térmicas (altas presiones hidrostáticas [APH], pulsos eléctricos de alta intensidad [PEAI], descargas eléctricas de alto voltaje [DEAV] y ultrasonidos [USN]), así como el estudio de la bioaccesibilidad de estos compuestos. La aplicación conjunta de dos estrategias de conservación (aplicación de tecno...

  18. Caracterización preliminar de los compuestos hidrofóbicos removidos de Andisoles repelentes al agua de Antioquia.

    Directory of Open Access Journals (Sweden)

    Jaramillo J. Daniel F.

    2000-06-01

    Full Text Available En 15 muestras de Andisoles repelentes al agua se caracterizaron los compuestos orgánicos extraídos por mezclas de etanol - benceno, 1:2 y de isopropanol - amoniaco 7:3; se confirmó que los compuestos responsables de la hidrofobicidad del suelo extraídos son poco humificados, tienen una composición general de ácidos carboxílicos alifáticos de cadenas largas y que corresponden a humus tipo Rp.

  19. Seronegative Neuromyelitis Optica Spectrum Disorder following Exposure to Hepatitis B Vaccination

    Directory of Open Access Journals (Sweden)

    Richard Heekin

    2015-04-01

    Full Text Available Controversy exists regarding a potential link between exposure to recombinant hepatitis B vaccine (HBV and central nervous system demyelinating diseases. Here, we present a case of seronegative neuromyelitis optica spectrum disorder (NMOSD following exposure to HBV. A 28-year-old man developed painful eye movements 11 days after exposure to HBV. Within 24 h, he experienced vision loss, ascending numbness, and ataxia. T-spine MRI showed a cord lesion spanning T6-T9. Brain MRI showed bilateral optic nerve contrast enhancement and a right-sided internal capsule lesion. Cerebrospinal fluid analysis was normal, including negative oligoclonal bands and normal IgG index. AQP4-IgG serology was negative. The patient's visual symptoms improved after treatment with steroids and plasma exchange. He received plasma exchange weekly for 4 weeks with decreased numbness and tingling as well as improved coordination. Treatment with mycophenolate mofetil was started, and the patient remains clinically stable with near resolution of his prior symptoms. Neuromyelitis optica is characterized by optic neuritis and/or longitudinally extensive transverse myelitis. While our patient tested seronegative for AQP4-IgG (which remains negative in 10-50% of NMOSD cases, despite testing with the most sensitive assays available, he did meet NMOSD diagnostic criteria. In a literature review, we found 7 cases of NMOSD onset or relapse associated with exposure to various vaccines, but to our knowledge this represents the first published report of NMOSD onset following exposure to HBV. While causality between vaccination and CNS demyelinating disease remains elusive, it is important to report these cases to help develop safer vaccinations and provoke further inquiry into the pathogenesis of NMOSD.

  20. Experimental Neuromyelitis Optica Induces a Type I Interferon Signature in the Spinal Cord

    Science.gov (United States)

    Kaufmann, Nathalie; Zeka, Bleranda; Schanda, Kathrin; Fujihara, Kazuo; Illes, Zsolt; Dahle, Charlotte; Reindl, Markus; Lassmann, Hans; Bradl, Monika

    2016-01-01

    Neuromyelitis optica (NMO) is an acute inflammatory disease of the central nervous system (CNS) which predominantly affects spinal cord and optic nerves. Most patients harbor pathogenic autoantibodies, the so-called NMO-IgGs, which are directed against the water channel aquaporin 4 (AQP4) on astrocytes. When these antibodies gain access to the CNS, they mediate astrocyte destruction by complement-dependent and by antibody-dependent cellular cytotoxicity. In contrast to multiple sclerosis (MS) patients who benefit from therapies involving type I interferons (I-IFN), NMO patients typically do not profit from such treatments. How is I-IFN involved in NMO pathogenesis? To address this question, we made gene expression profiles of spinal cords from Lewis rat models of experimental neuromyelitis optica (ENMO) and experimental autoimmune encephalomyelitis (EAE). We found an upregulation of I-IFN signature genes in EAE spinal cords, and a further upregulation of these genes in ENMO. To learn whether the local I-IFN signature is harmful or beneficial, we induced ENMO by transfer of CNS antigen-specific T cells and NMO-IgG, and treated the animals with I-IFN at the very onset of clinical symptoms, when the blood-brain barrier was open. With this treatment regimen, we could amplify possible effects of the I-IFN induced genes on the transmigration of infiltrating cells through the blood brain barrier, and on lesion formation and expansion, but could avoid effects of I-IFN on the differentiation of pathogenic T and B cells in the lymph nodes. We observed that I-IFN treated ENMO rats had spinal cord lesions with fewer T cells, macrophages/activated microglia and activated neutrophils, and less astrocyte damage than their vehicle treated counterparts, suggesting beneficial effects of I-IFN. PMID:26990978

  1. Neuromyelitis optica immunoglobulin G in Chinese patients detected by immunofluorescence assay on a monkey brain substrate.

    Science.gov (United States)

    Long, Youming; Hu, Xueqiang; Peng, Fuhua; Lu, Zhengqi; Wang, Yuge; Yang, Yu; Qiu, Wei

    2012-01-01

    Serum neuromyelitis optica immunoglobulin G (NMO-IgG) is used as a biomarker to differentiate between neuromyelitis optica (NMO) and multiple sclerosis (MS). However, the original assay is expensive and complex and shows low sensitivity. Here, we investigated the potential of NMO-IgG detection using an indirect immunofluorescence (IIF) assay on monkey brains. NMO-IgG seroprevalence was determined in 168 samples by an IIF assay on a monkey brain substrate. The data were compared with those from a standard mouse brain IIF assay using McNemar and kappa tests. Thirty-one of 50 (62%) NMO patients, 7 of 18 (38.9%) longitudinally extensive transverse myelitis patients, 6 of 57 (10.5%) MS patients, and 5 of 10 (50%) optic neuritis patients were seropositive for NMO-IgG. None of the acute partial transverse myelitis patients (n = 3) or healthy controls (n = 20) was positive. Thus, the sensitivity of the test was 62% for the patients with clinically definite NMO. The specificity was 89.5%, considering the 57 MS patients as the control group. The modified IIF assay on monkey brains and the standard IIF assay based on mouse brains were not significantly different (McNemar test; p = 1.000). The two assays were concordant in 39 seropositive samples and 100 seronegative samples (kappa test; kappa = 0.592, p monkey brain assay was no better than the standard mouse brain IIF assay, we affirmed that NMO-IgG is a sensitive and specific biomarker to differentiate between NMO and MS. Copyright © 2011 S. Karger AG, Basel.

  2. Neuromyelitis optica spectrum disease characteristics in Isfahan, Iran: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Fereshte Ashtari

    2017-01-01

    Full Text Available Background: Neuromyelitis optica spectrum disease (NMOSD is a severe autoimmune demyelinating disorder of the central nervous system that throughout epidemiological data, it has not been completely determined. The aim of this study was to assess characteristics of NMOSD patients in Isfahan as one of the most prevalent cities for multiple sclerosis in Iran. Materials and Methods: Forty-five patients diagnosed as neuromyelitis optica (NMO disease through 5 years enrolled in this study. Demographics and characteristics of disease such as Expanded Disability Status Scale (EDSS score, disease duration, clinical symptoms, laboratory data, and magnetic resonance imaging findings (including T1, T2, and flair protocols were recorded. NMO-immunoglobulin G serology assay was done in all of the patients by ELISA test. Results: Female to male ratio was 5.4:1. The mean age of disease onset was 29.8 ± 11.2 years. NMO antibody was positive in 24.4% of patients. The presenting symptoms were optic neuritis (55.5%, transverse myelitis (40%, and brainstem symptoms (4.5%. The interval between the first and second attack was 19.28 ± 31.27 months (range: 1 month to 17 years. The mean EDSS score of the patients was 2.8 ± 2.25. Frequency of long-extending cervical plaque was higher among men than women (85.7% vs. 57.9%. Conclusion: Based on this study, the mean age of NMOSD onset among Isfahan population was considerably lower than other studies, and there was higher frequency of long-extending cervical lesion among male patients which needs more consideration in further studies.

  3. Fibra da casca do coco verde como substrato agrícola

    Directory of Open Access Journals (Sweden)

    Carrijo Osmar Alves

    2002-01-01

    Full Text Available A produção comercial de mudas e o cultivo sem solo de hortaliças estão se tornando práticas comuns entre os olericultores. Vários materiais orgânicos como as turfas, resíduos de madeira, casca de pinus e de arroz parcialmente carbonizada ou não, ou materiais inorgânicos como areia, rochas vulcânicas, perlita, lã de rocha e a espuma fenólica já são utilizados como substratos, isoladamente ou em composição. A casca de coco verde que em muitas regiões causa transtorno ao serviço de limpeza pública pelo volume e pela dificuldade de decomposição produz uma fibra que pode ser utilizada como substrato. Para a produção da fibra, a casca de coco verde é picada, desfibrada, triturada, lavada e secada. Para o uso como substrato na produção de mudas, a fibra deve passar por um processo de compostagem. Este processo não é necessário para o uso como substrato em cultivo sem solo, mas no entanto, o substrato necessitará ser enriquecido com nutrientes em pré-plantio ou em fertirrigação. O uso do substrato da fibra de coco verde na produção de tomate em casa de vegetação, alcançou, em termos absolutos, 13,2 kg m-2 de frutos comerciais (média de 3 anos cerca de 7,3% mais que o segundo melhor substrato, o pó de serra com 12,3 kg m-2.

  4. PROPRIEDADES TERMOFÍSICAS DE COMPÓSITO DE MATRIZ DE GESSO E FIBRA VEGETAL

    Directory of Open Access Journals (Sweden)

    George Santos Marinho

    2013-03-01

    Full Text Available Foi desenvolvido um compósito de matriz de gesso e reforço de fibra vegetal (Cocos nucifera destinado à fabricação de elementos construtivos (e. g., placas para forração de coberturas e painéis de vedação. Corpos de prova foram produzidos na forma de sanduíche de gesso / fibra / gesso. Duas espessuras diferentes da fatia de fibra foram consideradas: 8 mm e 10 mm. Um corpo de prova de gesso sem a fatia de fibra foi fabricado para servir como padrão de comparação. Utilizando-se um equipamento analisador térmico, foram realizados ensaios para determinação das seguintes propriedades termofísicas dos corpos de prova: condutividade térmica (k, capacidade térmica volumétrica (.CP e difusividade térmica (. A partir dos resultados foi possível evidenciar vantagens do compósito em relação ao padrão. O menor valor de k conferiu ao compósito uma maior capacidade de isolação, possibilitando redução da carga térmica no interior das edificações devido à radiação solar. Nsse aspecto, o compósito se mostra adequado ao uso como elemento de vedação em edificações situadas em localidades de baixas latitudes (e. g., região Nordeste do Brasil. Além das vantagens citadas, o compósito pode proporcionar mais leveza e economia de material, possibilitando a produção de elementos construtivos mais esbeltos.

  5. Neuromyelitis optica spectrum disorder presenting with repeated hypersomnia due to involvement of the hypothalamus and hypothalamus-amygdala linkage.

    Science.gov (United States)

    Kume, Kodai; Deguchi, Kazushi; Ikeda, Kazuyo; Takata, Tadayuki; Kokudo, Yohei; Kamada, Masaki; Touge, Tetsuo; Takahashi, Toshiyuki; Kanbayashi, Takashi; Masaki, Tsutomu

    2015-06-01

    We report the case of a 46-year-old Japanese woman with neuromyelitis optica spectrum disorder presenting with repeated hypersomnia accompanied by decreased CSF orexin level. First episode associated with hypothalamic-pituitary dysfunction showed bilateral hypothalamic lesions that can cause secondary damage to the orexin neurons. The second episode associated with impaired memory showed a left temporal lesion involving the amygdala. The mechanism remains unknown, but the reduced blood flow in the hypothalamus ipsilateral to the amygdala lesion suggested trans-synaptic hypothalamic dysfunction secondary to the impaired amygdala. A temporal lesion involving the amygdala and hypothalamus could be responsible for hypersomnia due to neuromyelitis optica spectrum disorder. © The Author(s), 2015.

  6. An update on the evidence for the efficacy and safety of rituximab in the management of neuromyelitis optica

    Science.gov (United States)

    Collongues, Nicolas; de Seze, Jérôme

    2016-01-01

    Neuromyelitis optica spectrum disorders (NMOSDs) is a new concept which includes classical neuromyelitis optica (NMO) and partial forms of NMO such as recurrent optic neuritis with positive aquaporin-4 antibodies (AQP4) or brainstem symptoms (intractable hiccups or vomiting). This disease is clearly distinguished from multiple sclerosis (MS) and the therapeutic approach is clearly different. Rituximab is actually considered to be one of the most efficient treatments of NMOSD, even if class I studies are clearly lacking. In the present review, we describe the state of the art about rituximab treatment in NMOSD, including adults and children, plus its efficacy and tolerance and we also underline the questions that should be addressed in the near future. PMID:27134673

  7. An update on the evidence for the efficacy and safety of rituximab in the management of neuromyelitis optica.

    Science.gov (United States)

    Collongues, Nicolas; de Seze, Jérôme

    2016-05-01

    Neuromyelitis optica spectrum disorders (NMOSDs) is a new concept which includes classical neuromyelitis optica (NMO) and partial forms of NMO such as recurrent optic neuritis with positive aquaporin-4 antibodies (AQP4) or brainstem symptoms (intractable hiccups or vomiting). This disease is clearly distinguished from multiple sclerosis (MS) and the therapeutic approach is clearly different. Rituximab is actually considered to be one of the most efficient treatments of NMOSD, even if class I studies are clearly lacking. In the present review, we describe the state of the art about rituximab treatment in NMOSD, including adults and children, plus its efficacy and tolerance and we also underline the questions that should be addressed in the near future.

  8. Müller cells and retinal axons can be primary targets in experimental neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Zeka, Bleranda; Lassmann, Hans; Bradl, Monika

    2017-01-01

    Recent work from our laboratory, using different models of experimental neuromyelitis optica spectrum disorder (NMOSD), has led to a number of observations that might be highly relevant for NMOSD patients. For example: (i) in the presence of neuromyelitis optica immunoglobulin G, astrocyte-destructive lesions can be initiated by CD4+ T cells when these cells recognize aquaporin 4 (AQP4), but also when they recognize other antigens of the central nervous system. The only important prerequisite is that the T cells have to be activated within the central nervous system by "their" specific antigen. Recently activated CD4+ T cells with yet unknown antigen specificity are also found in human NMOSD lesions. (ii) The normal immune repertoire might contain AQP4-specific T cells, which are highly encephalitogenic on activation. (iii) The retina might be a primary target of AQP4-specific T cells and neuromyelitis optica immunoglobulin G: AQP4-specific T cells alone are sufficient to cause retinitis with low-grade axonal pathology in the retinal nerve fiber/ganglionic cell layer. A thinning of these layers is also observed in NMOSD patients, where it is thought to be a consequence of optic neuritis. Neuromyelitis optica immunoglobulin G might target cellular processes of Müller cells and cause their loss of AQP4 reactivity, when AQP4-specific T cells open the blood-retina barrier in the outer plexiform layer. Patchy loss of AQP4 reactivity on Müller cells of NMOSD patients has been recently described. Cumulatively, our findings in experimental NMOSD suggest that both CD4+ T cell and antibody responses directed against AQP4 might play an important role in the pathogenesis of tissue destruction seen in NMOSD.

  9. Serial quantitative MR assessment of optic neuritis in a case of neuromyelitis optica, using gadolinium-'enhanced' STIR imaging

    International Nuclear Information System (INIS)

    Barkhof, F.; Scheltens, P.; Valk, J.; Waalewijn, C.; Uitdehaag, B.M.J.; Polman, C.H.

    1991-01-01

    A patient is presented with neuromyelitis optica. MR imaging, using a short inversion time inversion recovery (STIR) technique, clearly depicted the lesion in the left optic nerve. Subsequent serial STIR imaging, with and without Gadolinium-DTPA, allowed quantitative assessment of changes parallel to improved optic nerve function. STIR imaging is a sensitive technique to demonstrate optic nerve lesions, and enables quantitative assessment to be made of the effect of (steroid) medication. (orig.)

  10. Theory of the Sagnac's interferometer of low birefringence and twist fiber; Teoria del interferometro de Sagnac de fibra de baja birrefrigencia y torcida

    Energy Technology Data Exchange (ETDEWEB)

    Estudillo-Ayala, J. M.; Kuzin, E. A.; Ibarra-Escamilla, B. [Instituto Nacional de Astrofisica, Optica y Electronica, Puebla (Mexico); Rojas-Laguna, R. [Universidad de Guanajuato, Guanajuato (Mexico)

    2001-06-01

    The fibre Sagnac interferometer of low birefringence and twist in the lineal region is examined numerically, a method is shown to measure the birefringence in the fibers and rotation of the axes inside of the interferometer fibre loop. [Spanish] El interferometro de Sagnac de fibra de baja birrefrigencia y torcida en la region lineal es numericamente examinado, se muestra un metodo para medir la birrefrigencia en las fibras y rotacion de los ejes dentro de la fibra del lazo del interferometro.

  11. Comportamiento mecánico del concreto reforzado con fibras de bagazo de caña de azúcar

    OpenAIRE

    Espinoza Carvajal, Marlon Jonathan

    2015-01-01

    El tema de investigación que a continuación vamos a describir se centra en el estudio de la incorporación de fibras naturales a una matriz de cemento. Primeramente se evaluó el Estado del Arte, verificando la existencia de estudios que tenga similitud con el tema y sirvan de referentes. Ya en campo empezamos con la recolección de la fibra natural en el Ingenio Monterrey, (MALCA), luego se procede con el aislamiento de la fibra por un tiempo no mayor a tres meses, esto ayuda a que la fibra...

  12. Combinación de fibras de acero de última generación para el refuerzo de hormigón autocompactante

    OpenAIRE

    Alberti, Marcos; Enfedaque, Alejandro; Galvez, Jaime; Cortez, Adriana

    2018-01-01

    [ES] Dado que la mayor desventaja mecánica del hormigón son sus propiedades en tracción, las fibras normalmente se utilizan para mejorar la respuesta frente a solicitaciones de tracción y flexión, siendo las fibras de acero las más comúnmente utilizadas. Este tipo de fibras se ha utilizado con éxito en aplicaciones estructurales en los últimos 50 años y, como consecuencia, se han desarrollado nuevas fibras de acero de última generación de las que existe una bibliografía muy lim...

  13. Efecto citotóxico de algunos compuestos naturales aislados de plantas Laureaceae y derivados sintéticos

    Directory of Open Access Journals (Sweden)

    Luis Enrique Cuca

    2011-03-01

    Conclusión. Los compuestos evaluados que exhibieron actividad contra la proliferación celular mostraron resultados interesantes, lo cual sugiere su potencial uso como cabezas de serie o moléculas plantilla en el desarrollo de agentes anticancerígenos.

  14. Compuestos sintéticos del tipo de estirilquinolinas con actividades leishmanicida y citotóxica

    Directory of Open Access Journals (Sweden)

    Emy Luz Sánchez

    2014-12-01

    Conclusión. A pesar de su toxicidad, el compuesto E3 de la 2-estirilquinolina demostró una actividad prometedora contra L. (V. panamensis, pues fue capaz de inhibir de manera significativa los amastigotes en el interior de la célula y de reducir la infección.

  15. Compuestos de Paladio soportados en distintos materiales. Aplicación en Catálisis heterogénea

    OpenAIRE

    Leyva Perez, Antonio

    2011-01-01

    Leyva Perez, A. (2005). Compuestos de Paladio soportados en distintos materiales. Aplicación en Catálisis heterogénea [Tesis doctoral no publicada]. Universitat Politècnica de València. doi:10.4995/Thesis/10251/1839.

  16. Desarrollo de prótesis ortopédicas en materiales compuestos para uso competitivo

    OpenAIRE

    Villar, Juan Ignacio; Fontana, Marco; Sznajderman, Lucas; Antokoletz, Sebastián Pablo

    2017-01-01

    El trabajo describe el diseño, construcción y posterior validación de una prótesis transtibial de uso competitivo destinada a carreras de velocidad. La misma es concebida en materiales compuestos y las bases del diseño contemplan la medición de parámetros biomecánicos del usuario para un posterior análisis de similaridad. Las principales características que se pretende lograr de una prótesis tipo ‘Flex- Foot’ son la respuesta elástica lineal, tamaño y proporción apropiada, frecuencia natur...

  17. Iron and Non-Iron-Related Characteristics of Multiple Sclerosis and Neuromyelitis Optica Lesions at 7T MRI.

    Science.gov (United States)

    Chawla, S; Kister, I; Wuerfel, J; Brisset, J-C; Liu, S; Sinnecker, T; Dusek, P; Haacke, E M; Paul, F; Ge, Y

    2016-07-01

    Characterization of iron deposition associated with demyelinating lesions of multiple sclerosis and neuromyelitis optica has not been well studied. Our aim was to investigate the potential of ultra-high-field MR imaging to distinguish MS from neuromyelitis optica and to characterize tissue injury associated with iron pathology within lesions. Twenty-one patients with MS and 21 patients with neuromyelitis optica underwent 7T high-resolution 2D-gradient-echo-T2* and 3D-susceptibility-weighted imaging. An in-house-developed algorithm was used to reconstruct quantitative susceptibility mapping from SWI. Lesions were classified as "iron-laden" if they demonstrated hypointensity on gradient-echo-T2*-weighted images and/or SWI and hyperintensity on quantitative susceptibility mapping. Lesions were considered "non-iron-laden" if they were hyperintense on gradient-echo-T2* and isointense or hyperintense on quantitative susceptibility mapping. Of 21 patients with MS, 19 (90.5%) demonstrated at least 1 quantitative susceptibility mapping-hyperintense lesion, and 11/21 (52.4%) had iron-laden lesions. No quantitative susceptibility mapping-hyperintense or iron-laden lesions were observed in any patients with neuromyelitis optica. Iron-laden and non-iron-laden lesions could each be further characterized into 2 distinct patterns based on lesion signal and morphology on gradient-echo-T2*/SWI and quantitative susceptibility mapping. In MS, most lesions (n = 262, 75.9% of all lesions) were hyperintense on gradient-echo T2* and isointense on quantitative susceptibility mapping (pattern A), while a small minority (n = 26, 7.5% of all lesions) were hyperintense on both gradient-echo-T2* and quantitative susceptibility mapping (pattern B). Iron-laden lesions (n = 57, 16.5% of all lesions) were further classified as nodular (n = 22, 6.4%, pattern C) or ringlike (n = 35, 10.1%, pattern D). Ultra-high-field MR imaging may be useful in distinguishing MS from neuromyelitis optica. Different

  18. Comportamiento dieléctrico de compuestos epoxi/aluminio/BaTiO3

    Directory of Open Access Journals (Sweden)

    Castro, M. S.

    2009-06-01

    Full Text Available In order to improve the dielectric behaviour of epoxi/BaTiO3, in this work the influence of micrometric aluminum metal flakes (Al, on the dielectric properties of epoxy / BaTiO3 composites was studied. Epoxy resin, Al and BaTiO3 were mixed using an ultrasonic mixer and composites were deposited onto glass substrates by dipping technique. Obtained materials presented good dielectric properties at room temperature, and relaxation process appeared due to the resin behaviour. Obtained results were compared with those reported in literature for similar systems.Con el objetivo de mejorar el comportamiento dieléctrico de los compuestos epoxi/BaTiO3, en este trabajo se estudió la influencia de partículas metálicas de aluminio (Al, con forma de escamas y tamaño micrométrico, sobre las propiedades dieléctricas de sistemas epoxi / BaTiO3. El material compuesto fue obtenido por la técnica de inmersión o “dipping”. La mezcla de los componentes fue llevado a cabo en mezclador ultrasónica y la deposición se realizó sobre sustratos de vidrio. Los materiales obtenidos presentaron buenas propiedades dieléctricas a temperatura ambiente, sin alcanzar el límite de percolación, y los fenómenos de relajación fueron generados por los dominios de la resina. Los valores obtenidos fueron comparados con los reportados en la bibliografía para sistemas similares.

  19. Análisis de los compuestos volátiles de la ciruela amarilla (Prunus domestica L. ssp. domestica

    Directory of Open Access Journals (Sweden)

    Yineth Ruiz

    2011-01-01

    Full Text Available El aroma de las frutas se debe a los constituyentes volátiles presentes que, aunque se encuentran en muy bajas concentraciones, contribuyen al aroma global en grados muy diversos. Se hace necesario usar técnicas de aislamiento y concentración que garanticen el análisis de una composición química semejante a la de la fruta. Este trabajo tuvo como objetivo el análisis de los compuestos volátiles de la ciruela amarilla (Prunus domestica L. ssp. domestica por el método de evaporación del aroma asistida por solvente (SAFE. Este método utiliza un equipo de destilación conectado a una bomba de alto vacío que ofrece la posibilidad de aislar rápidamente compuestos volátiles sin daño térmico en diferentes matrices alimentarias. La separación e identificación de los compuestos volátiles se realizó por cromatografía de gases-espectrometría de masas (GC-MS. Se identificaron 47 compuestos (6,55 mg/kg de pulpa de fruta, entre ellos 14 alcoholes, 8 aldehídos, 7 ésteres, 5 cetonas, 4 ácidos carboxílicos, 4 hidrocarburos aromáticos, 3 lactonas, un compuesto azufrado y una hidroxicetona; 16 de ellos se informan por primera vez. El acetato de etilo (2,88 mg/kg, etanol (1 mg/kg y ácido octanoico (0,78 mg/kg fueron los constituyentes volátiles mayoritarios de esta variedad de ciruela.

  20. Análisis de los compuestos volátiles de la ciruela amarilla (Prunus domestica L. ssp. domestica

    Directory of Open Access Journals (Sweden)

    Yineth Ruiz

    2011-06-01

    Full Text Available El aroma de las frutas se debe a los constituyentes volátiles presentes que, aunque se encuentran en muy bajas concentraciones, contribuyen al aroma global en grados muy diversos. Se hace necesario usar técnicas de aislamiento y concentración que garanticen el análisis de una composición química semejante a la de la fruta. Este trabajo tuvo como objetivo el análisis de los compuestos volátiles de la ciruela amarilla (Prunus domestica L. ssp.domestica por el método de evaporación del aroma asistida por solvente (SAFE. Este método utiliza un equipo de destilación conectado a una bomba de alto vacío que ofrece la posibilidad de aislar rápidamente compuestos volátiles sin daño térmico en diferentes matrices alimentarias. La separación e identificación de los compuestos volátiles se realizó por cromatografía de gases-espectrometría de masas (GC-MS. Se identificaron 47 compuestos (6,55 mg/kg de pulpa de fruta, entre ellos 14 alcoholes, 8 aldehídos, 7 ésteres, 5 cetonas, 4 ácidos carboxílicos, 4 hidrocarburos aromáticos, 3 lactonas, un compuesto azufrado y una hidroxicetona; 16 de ellos se informan por primera vez. El acetato de etilo (2,88 mg/kg, etanol (1 mg/kg y ácido octanoico (0,78 mg/kg fueron los constituyentes volátiles mayoritarios de esta variedad de ciruela.

  1. El Nopal fresco como fuente de fibra y calcio en panqués El Nopal fresco como fuente de fibra y calcio en panqués

    Directory of Open Access Journals (Sweden)

    José Eleazar Barboza- Corona

    2012-02-01

    Full Text Available El objetivo de este trabajo fue utilizar nopal fresco en la formulación de panqués para incrementar su contenido de fibra dietética y calcio. Se desarrollaron cinco formulaciones de panqués utilizando nopal fresco (Opuntia amyclaea Tenore, 4 con sucralosa (una testigo sin nopal y una con azúcar y nopal. Se evaluaron sensorialmente por 60 jueces no entrenados mediante la prueba de preferencia, utilizando una escala hedónica del 1 al 9. Se les determinó el contenido de proteína (Nx6.25, humedad, cenizas, lípidos, hidratos de carbono, fibra dietética total, calcio y fósforo por los métodos de la AOAC, (1990. Los resultados revelaron contenidos de proteínas (Nx6.25 entre 9.54 y 10.08, de humedad entre 35.75 y 40.00, de cenizas, 2.29 g/100 g y 2.44 g/100 g peso húmedo. La evaluación sensorial mostró una buena aceptación, los contenidos de fibra dietética total estuvieron entre 8.27 % y 10.43 % y los de calcio entre 0.27 y 0.375 g/100 g. El valor calórico fue de 216.02 kcal a 225.68 kcal kJ/100 g de panqué, aproximadamente 50 % menos que los que se ofrecen en el mercado. Por su alto contenido de fibra y calcio, ausencia de azúcar y bajo valor calórico estos productos podrían ser una opción saludable para personas diabéticas y obesas.The aim of this work was to utilize fresh cactus as a source of dietary fiber and calciumin pound cake formulations. Five pound cake formulations using fresh cactus (Opuntiaamyclaea Tenore were developed (four with sucralosa, one of them without cactus andone with sugar cane and cactus. Sensory evaluation was performed by 60 untrained judgesand based on a preference assay with a hedonic scale from 1 to 9. Protein (Nx6.25,lipids, ashes, carbohydrates, total dietary fiber, calcium and phosphorus were determinedaccording to the methods of the AOAC, (1990. The results showed protein contentsfrom 9.54 to 10.08, moisture from 35.75 to 40.00, lipids from 2.29 g/100 g y 2.44 g/100g fresh weight. The

  2. Neuromyelitis Optica

    Science.gov (United States)

    ... may help prevent with accumulation of disability. Rarely, muscle weakness can be severe enough to cause breathing difficulties and may require the use of artificial ventilation. x Prognosis Most individuals with NMO have ...

  3. Avaliação da determinação da fibra em detergente neutro e da fibra em detergente ácido pelo sistema ANKOM

    Directory of Open Access Journals (Sweden)

    Berchielli Telma Teresinha

    2001-01-01

    Full Text Available O objetivo do trabalho foi comparar os valores de fibra em detergente neutro (FDN e os de fibra em detergente ácido (FDA obtidos com o equipamento ANKOM e pelo método convencional (Van Soest. No primeiro ensaio foram analisados cinco materiais diferentes (cana-de-açúcar, capim-braquiária, silagem de milho, polpa cítrica e fezes bovina e testados quatro tipos de saquinhos para filtragem de amostra. O delineamento experimental foi em blocos casualizados, em um fatorial 5x4 (cinco materiais diferentes e quatro tipos de saquinhos de filtragem, com três repetições. As médias obtidas foram comparadas àquelas obtidas com método convencional. No segundo ensaio procurou-se avaliar o efeito da quantidade de amostra por saquinho (0,5; 0,8 e 1,0 g sobre os teores de FDN e FDA em três tipos de alimentos, utilizando o ANKOM. Neste ensaio, o delineamento experimental foi em blocos casualizados em esquema fatorial 3x3 (três alimentos x três quantidades, com três repetições. Os tipos de saquinhos de filtragem utilizados não influenciaram os teores de FDN nos diferentes alimentos, com exceção das fezes, cujos saquinhos de náilon resultaram em concentrações de FDN inferiores. Não houve diferença entre os valores de FDN e FDA, obtidos pelo equipamento ANKOM ou pelo convencional, para os alimentos estudados, com exceção da polpa cítrica, cujo valor médio de FDA pelo ANKOM foi inferior àquele obtido pelo método convencional. A quantidade não exerceu efeito sobre a concentração de FDN dos alimentos analisados no equipamento ANKOM.

  4. Tenacidad a la fractura de compuestos cermets 3Al2O3*2SiO2/Ag manufacturados por molienda de alta energía

    OpenAIRE

    Hernández,José G. Miranda; Bustamante,Miriam Vázquez; Hernández,Héctor Herrera; Morán,Carlos O. González; Rangel,Enrique Rocha; García,Elizabeth Refugio

    2016-01-01

    La fabricación de materiales compuestos de matriz cerámica reforzados con partículas metálicas han propiciado la formación de nuevos materiales conocidos como compuestos CERMETS, materiales que debido a sus elementos precursores poseen propiedades distintas a las de los materiales convencionales. En este trabajo se establece la ruta de fabricación de materiales compuestos cermets base 3Al2O3*2SiO2 reforzados con partículas metálicas de Ag a partir de la formación de la composición química en ...

  5. Características de adhesión entre fibras de queratina y poliéster insaturado

    Directory of Open Access Journals (Sweden)

    Marco Paniagua

    2008-01-01

    Full Text Available En este trabajo se presentan los métodos y resultados utilizados para determinar las características de adhesión entre fibras de queratina y una matriz de poliéster insaturado. Las fibras fueron preparadas con varios tratamientos superficiales para determinar el efecto de estos en la adhesión a la matriz mediante: i pruebas de desgarre de monofilamento, pull-out, como método directo de medición y ii pruebas de tensión en laminados como método indirecto para estudiar, mediante microscopía electrónica SEM, la adhesión fibra matriz en la zona de fractura.

  6. Estudo da Estabilização Termo-Oxidativa de Fitas e Feixes de Fibras de Poliacrilonitrila

    Directory of Open Access Journals (Sweden)

    Costa Andréa M. A. R.

    2002-01-01

    Full Text Available Os estudos relacionados ao processo de fabricação de fibras de carbono indicam que a etapa de estabilização termo-oxidativa das fibras precursoras é limitante, envolvendo reações químicas complexas e mudanças na estrutura física das fibras. Com o objetivo de se conhecer melhor a etapa de estabilização e eliminar gastos em testes experimentais, a modelagem e a simulação surgem para tentar otimizar este processo. Apresenta-se neste trabalho um modelo matemático para a etapa de estabilização de uma fita de fibras de poliacrilonitrila. As equações do modelo descrevem as principais reações químicas de estabilização, a difusão de oxigênio e a transferência de calor na fita. Para a resolução do modelo foi desenvolvido um programa computacional na linguagem Fortran, utilizando os métodos de Colocação Ortogonal e Rungefraction three-quarters Kutta Semi-implícito. Foram obtidos resultados de temperaturas e concentrações na fita de fibras de poliacrilonitrila em função do tempo de estabilização e da posição na espessura da fita. Estes resultados foram analisados e comparados com os simulados em um feixe de fibras de poliacrilonitrila e indicaram que a transferência de calor na fita é melhor do que no feixe e conseqüentemente as reações exotérmicas são mais controladas.

  7. Mechanical properties of unidirectional laminates with carbon fiber and epoxy resin DA4518U USG0540; Propiedades mecanicas de los laminados unidireccionales de fibra de carbono con resina epoxica DA4518U Y USG0540

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Melo, Monica I.; Rubio Gonzalez, Carlos; Del Llano Vizcaya, Luis [CIDESI. Centro de Ingenieria y Desarrollo Industrial Queretaro, Queretaro (Mexico)]. E-mail: monica.sanchez.melo@gmail.com; crubio@cidesi.mx; lvizcaya@cidesi.mx

    2010-11-15

    In this paper, a study of the mechanical properties of composite materials with carbon fiber and epoxy resin DA4518U USG0540 is described, due to no such properties have been published to date, this study is performed. This work is developed at the Center for Engineering and Industrial Development (CIDESI). As a part of this research, the elastic modulus, Poisson's ratio and shear modulus are obtained both analytical and experimentally. Tests are performed to high cycle fatigue in both materials, and then these specimens are examined by ultrasound with the immersion technique in order to detect variations in material delamination, changes in obtain the attenuation and wave propagation. Finally, the tensional test to the specimen fatigue is repeated for changes in their mechanical properties. Also, a comparison is made between the results to determine which of those materials is more reliable for future applications in the aerospace industry. [Spanish] En este articulo se describe el estudio de las propiedades mecanicas de los materiales compuestos de fibra de carbono con resina epoxica DA4518U y USG0540, dicho estudio se lleva a cabo debido a que, a la fecha, no se han publicado tales propiedades, este trabajo se desarrollo en el Centro de Ingenieria y desarrollo Industrial (CIDESI). Como parte de esta investigacion, se obtienen analitica y experimentalmente el modulo de elasticidad, modulo de Poisson y modulo de corte. Tambien se realizan pruebas de fatiga a altos ciclos en ambos materiales, posteriormente estos especimenes se examinan por ultrasonido con la tecnica de inmersion para detectar variaciones en el material como delaminaciones, cambios de atenuacion y en la velocidad de propagacion de onda. Por ultimo se repite la prueba de tension a la probeta fatiga para conocer los cambios en sus propiedades mecanicas. Asi mismo se hace una comparacion entre los resultados obtenidos, para determinar cual material es mas confiable para futuras aplicaciones en la

  8. Propiedades mecánicas de morteros de cemento con adiciones de fibras de carbono, nanotubos de carbono y grafeno = Mechanical properties of cement mortars with additions of carbon fibres, carbon nanotubes and graphene

    Directory of Open Access Journals (Sweden)

    María Ursúa Goicoechea

    2017-12-01

    Full Text Available El carbono es uno de los elementos más abundantes de la naturaleza. Su particular estructura hace que pueda tener hasta cinco tipos distintos de alótropos. Durante los últimos años se han producido grandes avances en el estudio de estos materiales de carbono. Las fibras de carbono (CF, los nanotubos de carbono (CNTs y el grafeno y óxido de grafeno (GO, en función de su estructura y su escala, presentan unas propiedades notablemente diferenciadas. Este estudio pretende comparar y determinar los efectos de estas características en matrices de cemento. Las características de estos materiales son difíciles de transmitir de forma exacta a los compuestos de cemento y hormigones, principalmente por las dificultades que presentan los nanomateriales en su dispersión. Por ello, los datos obtenidos en distintos estudios muestran resultados muy variables. Sin embargo, se ha demostrado que, para mejoras medias, los nanomateriales resultan ser más eficientes. Abstract Carbon is one of the most abundant elements of nature. Its particular structure has to have up to five different types of allotropes. During the last years there have been great advances in the study of these carbon materials. Carbon fibers (CF, carbon nanotubes (CNT and graphene and graphene oxide (GO, depending on their structure and scale, have remarkably different properties. This study aims to compare and determine the effects of these characteristics on cement matrices. The characteristics of these materials are difficult to transmit accurately to concrete and cement compounds, mainly due to the difficulties presented by nanomaterials in their dispersion. Therefore, the data obtained in different studies, results, very variable. However, it has been shown that, for average improvements, nanomaterials are more efficient.

  9. Efeito da fibra do polissacarídeo de soja no peso e na umidade das fezes de ratos em fase de crescimento

    OpenAIRE

    Freitas,Karine C.; Motta,Maria Eugênia F. A.; Amâncio,Olga M. S.; Fagundes Neto,Ulysses; Morais,Mauro B.

    2004-01-01

    OBJETIVO: Comparar, em ratos, o efeito do polissacarídeo de soja em relação a celulose e fórmula de soja sem fibra alimentar sobre o peso e a umidade fecal. MÉTODOS: Foram utilizados 12 ratos Wistar machos, com 21 dias de vida, distribuídos em três grupos, que receberam ração AIN-93G variando-se a fonte de fibra alimentar: grupo polissacarídeo, com 5% de fibra na forma de polissacarídeo de soja; grupo fórmula de soja, com 5% de fórmula de soja sem fibra; e grupo celulose, com 5% de fibra na f...

  10. Limit of detection of a fiber optics gyroscope using a super luminescent radiation source; Limite de deteccion de un giroscopio de fibra optica usando una fuente de radiacion superluminiscente

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval R, G.E. [Laboratorio de Optica Aplicada, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-186, 04510 Mexico D.F. (Mexico); Nikolaev, V.A. [Departamento de Optica y Radiofisica Cuantica, Universidad Estatal de Telecomunicaciones de San Petersburgo, M.A. Bonch-Bruyevich, Kanal Moika 61, Saint Petersburg 191186, (Russian Federation)

    2003-07-01

    The main objective of this work is to establish the dependence of characteristics of the fiber optics gyroscope (FOG) with respect to the parameters of the super luminescent emission source based on doped optical fiber with rare earth elements (Super luminescent Fiber Source, SFS), argument the pumping rate election of the SFS to obtain characteristics limits of the FOG sensibility. By using this type of emission source in the FOG is recommend to use the rate when the direction of the pumping signal coincide with the super luminescent signal. The most results are the proposition and argumentation of the SFS election as emission source to be use in the FOG of the phase type. Such a decision allow to increase the characteristics of the FOG sensibility in comparison with the use of luminescent source of semiconductors emission which are extensively used in the present time. The use of emission source of the SFS type allow to come closer to the threshold of the obtained sensibility limit (detection limit) which is determined with the shot noise. (Author)

  11. Experimental study and by Monte Carlo of a prototype of hodoscopic of fibre optics for high resolution applications; Estudio experimental y por Monte Carlo de un prototipo de hodoscopio de fibras opticas para aplicaciones de alta resolucion

    Energy Technology Data Exchange (ETDEWEB)

    Granero, D.; Blasco, J. M.; Sanchis, E.; Gonzalez, V.; Martin, J. D.; Ballester, F.; Sanchis, E.

    2013-07-01

    The purpose of this work is to test the response of a system composed of 21 scintillators radiation fibres and its electronics as proof of the validity of the System. For this it has radiated test system with a source of verification of Sr-90. In addition, performed Monte Carlo simulations of the system by comparing the results of the simulations with those obtained experimentally. Moreover taken an approximation to the behavior of a hodoscopic composed of 100 scintillators, transverse fibers between if, in proton therapy, conducting different Monte Carlo simulations. (Author)

  12. Optical fibre-lightning arrester cable appliances. Its repercussion in concrete unconventional power transmission lines projects; Aplicacao de cabo para-raios composto com fibra optica. Sua repercursao em projetos de LT`s concreto nao convencionais

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Ramon Sade [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil)

    1993-12-31

    With the adoption of lightning rod cables made of Optical Fibre, (in systems over Europe, Japan and North America), these became very popular in Countries capable of installing the system. The Brazilian electrical party was then challenged by a new technological experience: the lightning rod cable for lines of transmission has specific characteristics. The particularity of the electrical system in Brazil in relation to the diversity of the parameters involved, and the necessity to clarifying the concepts, take us to new strategies in planning and measuring our Power Transmission Lines 4 refs., 1 tab.

  13. Optical fibres sensor based in the intensity switch of a linear laser with two Bragg gratings; Sensor de fibra optica basado en el salto de intensidad de un laser lineal con dos rejillas de Bragg

    Energy Technology Data Exchange (ETDEWEB)

    Basurto P, M.A.; Kuzin, E.A.; Archundia B, C.; Marroquin, E.; May A, M.; Cerecedo N, H.H.; Sanchez M, J.J. [Departamento de Fotonica y Fisica Optica, Instituto Nacional de Astrofisica, Optica y Electronica (INAOE). Apartado Postal 51 y 216, 72000 Puebla (Mexico); Tentori S, D.; Marquez B, I.; Shliagin, M.; Miridonov, S. [Centro de Investigacion CESE (Mexico)

    2000-07-01

    In this work we propose a new configuration for an optical fiber temperature sensor, based on a linear type Er-doped fiber laser. The laser cavity consists of an Er-doped fiber and two identical Bragg gratings at the fiber ends (working as reflectors). Temperature changes are detected by measuring, through one of the gratings, the intensity variations atthe system's output. When the temperature of one of the Bragg gratings is modified, a wavelength shift of its spectral reflectivity is observed. Hence, the laser emission intensity of the system is modified. We present experimental results of the intensity switch observed when the temperature difference between the gratings detunes their spectral reflectance. Making use of this effect it is possible to develop limit comparators to bound the temperature range for the object under supervision. This limiting work can be performed with a high sensitivity using a very simple interrogation procedure. (Author)

  14. Variación de la estructura fina de las fibras acrílicas en la hilatura

    OpenAIRE

    Gacén Guillén, Joaquín; Maillo Garrido, Josefina; Manich i Bou, Albert Mª; Ussmane, Mahomed

    2002-01-01

    Dos fibras acrílicas comerciales de diferente finura han sido transformadas en hilados en continua de hilar (3.3. dtex) y en hilatura de rotor (1.3 dtex). Los hilos resultantes han sido vaporizados y teñidos en condiciones standard. Las variaciones de la estructura producidas por las operaciones de hilatura, vaporizado y tintura han sido evaluadas a través del ensayo de solubilidad de las fibras acrílicas en una mezcla dimetilformamida/agua (95/5). Two commercial acrylic fibres of d...

  15. Variación de la estructura fina de las fibras acrílicas en la hilatura

    OpenAIRE

    Gacén Guillén, Joaquín; Maillo Garrido, Josefina; Manich i Bou, Albert Mª; Ussmane, Mahomed

    2002-01-01

    [ESP] Dos fibras acrílicas comerciales de diferente finura han sido transformadas en hilados en continua de hilar (3.3. dtex) y en hilatura de rotor (1.3 dtex). Los hilos resultantes han sido vaporizados y teñidos en condiciones standard. Las variaciones de la estructura producidas por las operaciones de hilatura, vaporizado y tintura han sido evaluadas a través del ensayo de solubilidad de las fibras acrílicas en una mezcla dimetilformamida/agua (95/5).

  16. Fertilidade de substratos para mudas de mangabeira, contendo fibra de coco e adubados com fósforo

    OpenAIRE

    Dias,Thiago Jardelino; Pereira,Walter Esfrain; Sousa,Geocleber Gomes de

    2007-01-01

    Este experimento foi executado no Centro de Ciências Agrárias da UFPB, Areia, Estado da Paraíba, com objetivo de avaliar a fertilidade de substratos compostos por diferentes concentrações de fibra de coco (0 a 40%), esterco bovino (0 a 25%), terra vegetal (25 a 70%), 15% de areia e adubados com superfosfato triplo (0; 5,5 e 11 g L-1). Houve aumento das características químicas desejáveis do substrato com aumento da concentração de terra vegetal, fibra de coco e dose máxima do superfosfato tri...

  17. Hernia hiatal y su relación con la ingestión de fibra dietética

    OpenAIRE

    Rodríguez Miranda, Adelaida; González-Carbajal Pascual, Miguel; Naranjo Hernández, Daysi; Valdés Alonso, Lidunka; Companioni Acosta, Susana

    1995-01-01

    Se estudiaron 226 pacientes con diagnóstico de hernia hiatal por radiología, endoscopia y manometría esofágica y 200 controles normales para determinar la cantidad de fibra dietética ingerida y su relación con la hernia hiatal. Se encontró que los pacientes que presentaron hernia hiatal consumían menos cantidad de fibra dietética que los controles, lo cual fue demostrado estadísticamente.

  18. Papel de la fibra dietética en la prevención de las enfermedades cardiovasculares

    OpenAIRE

    María Zurdo Seijas, Claudia

    2015-01-01

    Las enfermedades cardiovasculares constituyen una de las principales causas de muerte en España. Casi todos los factores de riesgo cardiovascular son modificables, ya que tienen relación con el estilo de vida, y más concretamente, con la alimentación. La relación entre el consumo de fibra y las enfermedades cardiovasculares ha sido muy estudiada, tanto a través de ensayos clínicos como en los grandes estudios de cohortes. El objetivo de este trabajo es describir los tipos de fibra dietética q...

  19. Conocimiento y hábitos en relación a la fibra dietética: resultados preliminaries

    OpenAIRE

    Leal, Marcela; Carranza, C; Herrera, J; Guiné, Raquel

    2015-01-01

    Introducción. El consumo de fibra dietética, y el conocimiento de sus beneficios son fundamentales en el cambio de conducta alimentaria para la prevención de ECNT. Objetivo. Describir los hábitos de consumo de alimentos con fibra dietética y el nivel de conocimiento. Metodología. Estudio cuantitativo, descriptivo, no experimental transversal, parte del proyecto internacional del Instituto Politécnico (Portugal) donde participan 10 países. Muestra no probabilística por voluntarios de 8...

  20. Altered topological organization of white matter structural networks in patients with neuromyelitis optica.

    Directory of Open Access Journals (Sweden)

    Yaou Liu

    Full Text Available OBJECTIVE: To investigate the topological alterations of the whole-brain white-matter (WM structural networks in patients with neuromyelitis optica (NMO. METHODS: The present study involved 26 NMO patients and 26 age- and sex-matched healthy controls. WM structural connectivity in each participant was imaged with diffusion-weighted MRI and represented in terms of a connectivity matrix using deterministic tractography method. Graph theory-based analyses were then performed for the characterization of brain network properties. A multiple linear regression analysis was performed on each network metric between the NMO and control groups. RESULTS: The NMO patients exhibited abnormal small-world network properties, as indicated by increased normalized characteristic path length, increased normalized clustering and increased small-worldness. Furthermore, largely similar hub distributions of the WM structural networks were observed between NMO patients and healthy controls. However, regional efficiency in several brain areas of NMO patients was significantly reduced, which were mainly distributed in the default-mode, sensorimotor and visual systems. Furthermore, we have observed increased regional efficiency in a few brain regions such as the orbital parts of the superior and middle frontal and fusiform gyri. CONCLUSION: Although the NMO patients in this study had no discernible white matter T2 lesions in the brain, we hypothesize that the disrupted topological organization of WM networks provides additional evidence for subtle, widespread cerebral WM pathology in NMO.

  1. Use of Advanced Magnetic Resonance Imaging Techniques in Neuromyelitis Optica Spectrum Disorder

    Science.gov (United States)

    Kremer, Stephane; Renard, Felix; Achard, Sophie; Lana-Peixoto, Marco A.; Palace, Jacqueline; Asgari, Nasrin; Klawiter, Eric C.; Tenembaum, Silvia N.; Banwell, Brenda; Greenberg, Benjamin M.; Bennett, Jeffrey L.; Levy, Michael; Villoslada, Pablo; Saiz, Albert; Fujihara, Kazuo; Chan, Koon Ho; Schippling, Sven; Paul, Friedemann; Kim, Ho Jin; de Seze, Jerome; Wuerfel, Jens T.

    2016-01-01

    Brain parenchymal lesions are frequently observed on conventional magnetic resonance imaging (MRI) scans of patients with neuromyelitis optica (NMO) spectrum disorder, but the specific morphological and temporal patterns distinguishing them unequivocally from lesions caused by other disorders have not been identified. This literature review summarizes the literature on advanced quantitative imaging measures reported for patients with NMO spectrum disorder, including proton MR spectroscopy, diffusion tensor imaging, magnetization transfer imaging, quantitative MR volumetry, and ultrahigh-field strength MRI. It was undertaken to consider the advanced MRI techniques used for patients with NMO by different specialists in the field. Although quantitative measures such as proton MR spectroscopy or magnetization transfer imaging have not reproducibly revealed diffuse brain injury, preliminary data from diffusion-weighted imaging and brain tissue volumetry indicate greater white matter than gray matter degradation. These findings could be confirmed by ultrahigh-field MRI. The use of nonconventional MRI techniques may further our understanding of the pathogenic processes in NMO spectrum disorders and may help us identify the distinct radiographic features corresponding to specific phenotypic manifestations of this disease. PMID:26010909

  2. The Contribution of Optical Coherence Tomography in Neuromyelitis Optica Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Javier Mateo

    2017-09-01

    Full Text Available Neuromyelitis optica spectrum disorders (NMOSD comprises a group of central nervous system disorders of inflammatory autoimmune origin that mainly affect the optic nerves and the spinal cord and can cause severe visual and general disability. The clinical signs are similar to those of multiple sclerosis (MS, with the result that it is often difficult to differentiate between the two, thus leading to misdiagnosis. As the treatment and prognosis of NMOSD and MS are different, it is important to make an accurate and early diagnosis of NMOSD. Optical coherence tomography (OCT is a non-invasive technique that enables a quantitative study of the changes that the optic nerve and the macula undergo in several neurodegenerative diseases. Many studies have shown that some of these changes, such as retinal nerve fiber layer thinning or microcystic macular edema, can be related to alterations in the brain due to neurodegenerative disorders. The purpose of this mini-review is to show how OCT can be useful for the diagnosis of NMOSD and follow-up of affected patients, as well as for the differential diagnosis with MS.

  3. Default-mode network and deep gray-matter analysis in neuromyelitis optica patients.

    Science.gov (United States)

    Rueda-Lopes, Fernanda C; Pessôa, Fernanda M C; Tukamoto, Gustavo; Malfetano, Fabíola Rachid; Scherpenhuijzen, Simone Batista; Alves-Leon, Soniza; Gasparetto, Emerson L

    2018-02-20

    The aim of our study was to detect functional changes in default-mode network of neuromyelitis optica (NMO) patients using resting-state functional magnetic resonance images and the evaluation of subcortical gray-matter structures volumes. NMO patients (n=28) and controls patients (n=19) were enrolled. We used the integrated registration and segmentation tool, part of FMRIB's Software Library (FSL) to segment subcortical structures including the thalamus, caudate nucleus, putamen, hippocampus and amygdalae. Resting-state functional magnetic resonance images were post-processed using the Multivariate Exploratory Linear Optimized Decomposition into Independent Components, also part of FSL. Average Z-values extracted from the default-mode network were compared between patients and controls using t-tests (P values default-mode network of patients compared to controls, notably in the precuneus and right hippocampus (corrected Pdefault-mode network. The hyperactivity of certain default-mode network areas may reflect cortical compensation for subtle structural damage in NMO patients. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  4. Comparative clinical characteristics of neuromyelitis optica spectrum disorders with and without medulla oblongata lesions.

    Science.gov (United States)

    Wang, Yanqiang; Zhang, Lei; Zhang, Bingjun; Dai, Yongqiang; Kang, Zhuang; Lu, Ciyong; Qiu, Wei; Hu, Xueqiang; Lu, Zhengqi

    2014-05-01

    Brainstem involvement, especially the medulla oblongata (MO), has been reported in neuromyelitis optica spectrum disorders (NMOSDs). The purpose of this study was to investigate retrospectively and compare clinical, laboratory, and imaging features of NMOSDs with and without MO lesions. A total of 170 patients with NMOSDs were enrolled, including 44 patients with MO lesions and 126 patients without MO lesions. Clinical features, laboratory tests, and magnetic resonance imaging findings among these patients were assessed. MO lesions were found in 25.9 % of the NMOSDs patients. The mean duration was 13 months. Patients with MO lesions had a higher Annualized relapse rate and Expanded Disability Status Score Scale. Headache, dizziness, nystagmus, dysarthria, intractable hiccup and nausea, choking cough or dysphagia, movement disorders, and neuropathic pain were more common in MO lesion patients. Patients with MO lesions were more frequently complicated with thyroid diseases. Multiple brain involvement, More importantly, Longitudinally extensive transverse myelitis were more frequently found in patients with MO lesions. MO lesions might be a symbol of more severe neurologic deficits and worse prognosis of NMOSDs.

  5. Multifrequency magnetic resonance elastography of the brain reveals tissue degeneration in neuromyelitis optica spectrum disorder

    International Nuclear Information System (INIS)

    Streitberger, Kaspar-Josche; Fehlner, Andreas; Sack, Ingolf; Pache, Florence; Lacheta, Anna; Papazoglou, Sebastian; Brandt, Alexander; Bellmann-Strobl, Judith; Ruprecht, Klemens; Braun, Juergen; Paul, Friedemann; Wuerfel, Jens

    2017-01-01

    Application of multifrequency magnetic resonance elastography (MMRE) of the brain parenchyma in patients with neuromyelitis optica spectrum disorder (NMOSD) compared to age matched healthy controls (HC). 15 NMOSD patients and 17 age- and gender-matched HC were examined using MMRE. Two three-dimensional viscoelastic parameter maps, the magnitude G* and phase angle φ of the complex shear modulus were reconstructed by simultaneous inversion of full wave-field data in 1.9-mm isotropic resolution at 7 harmonic drive frequencies from 30 to 60 Hz. In NMOSD patients, a significant reduction of G* was observed within the white matter fraction (p = 0.017), predominantly within the thalamic regions (p = 0.003), compared to HC. These parameters exceeded the reduction in brain volume measured in patients versus HC (p = 0.02 whole-brain volume reduction). Volumetric differences in white matter fraction and the thalami were not detectable between patients and HC. However, phase angle φ was decreased in patients within the white matter (p = 0.03) and both thalamic regions (p = 0.044). MMRE reveals global tissue degeneration with accelerated softening of the brain parenchyma in patients with NMOSD. The predominant reduction of stiffness is found within the thalamic region and related white matter tracts, presumably reflecting Wallerian degeneration. (orig.)

  6. Neuromyelitis optica IgG stimulates an immunological response in rat astrocyte cultures.

    Science.gov (United States)

    Howe, Charles L; Kaptzan, Tatiana; Magaña, Setty M; Ayers-Ringler, Jennifer R; LaFrance-Corey, Reghann G; Lucchinetti, Claudia F

    2014-05-01

    Neuromyelitis optica (NMO) is a primary astrocyte disease associated with central nervous system inflammation, demyelination, and tissue injury. Brain lesions are frequently observed in regions enriched in expression of the aquaporin-4 (AQP4) water channel, an antigenic target of the NMO IgG serologic marker. Based on observations of disease reversibility and careful characterization of NMO lesion development, we propose that the NMO IgG may induce a dynamic immunological response in astrocytes. Using primary rat astrocyte-enriched cultures and treatment with NMO patient-derived serum or purified IgG, we observed a robust pattern of gene expression changes consistent with the induction of a reactive and inflammatory phenotype in astrocytes. The reactive astrocyte factor lipocalin-2 and a broad spectrum of chemokines, cytokines, and stress response factors were induced by either NMO patient serum or purified IgG. Treatment with IgG from healthy controls had no effect. The effect is disease-specific, as serum from patients with relapsing-remitting multiple sclerosis, Sjögren's, or systemic lupus erythematosus did not induce a response in the cultures. We hypothesize that binding of the NMO IgG to AQP4 induces a cellular response that results in transcriptional and translational events within the astrocyte that are consistent with a reactive and inflammatory phenotype. Strategies aimed at reducing the inflammatory response of astrocytes may short circuit an amplification loop associated with NMO lesion development. Copyright © 2014 Wiley Periodicals, Inc.

  7. A voxel-based morphometry study of brain volume changes in patients with neuromyelitis optica

    International Nuclear Information System (INIS)

    Duan Yunyun; Liu Yaou; Liang Peipeng; Huang Jing; Ren Zhuoqiong; Ye Jing; Dong Huiqing; Chen Hai; Li Kuncheng

    2012-01-01

    Objective: To detect changes of regional grey matter and white matter volume in patients of neuromyelitis optica (NMO) by voxel-based morphometry (VBM), and investigate its relationship with clinical variables. Methods: Conventional magnetic resonance imaging (MRI) and structural three-dimensional MRI were obtained from 20 NMO and 20 sex-and age-matched healthy volunteers. The comparison of grey matter and white matter volume between the two groups was analyzed by VBM tools of statistical parametric mapping (SPM) 5. Pearson correlation analysis was used to assess correlations between regional volume decrease and disease duration and expanded disability status scale (EDSS) scores in NMO patients. Results: Compared with normal controls, NMO patients had grey matter atrophy in several cortical regions, such as right inferior frontal gyrus (cluster size 514), left superior temporal gyrus (282), right middle temporal gyrus (229) and right insula (211) (t=3.58-5.11, AlphaSim corrected, P<0.05). White matter atrophy was found in several subcortical regions in NMO patients, such as right precentral and postcentral gyrus (cluster size 457, 110), left middle frontal gyrus (285), and right inferior parietal lobule (231) (t=2.90-4.25, AlphaSim corrected, P<0.05). Grey matter and white matter volume loss were not significantly correlated with clinical duration or EDSS score in NMO. Conclusion: By means of VBM, regional atrophy of grey matter and white matter is found in NMO patients, which may provide evidence for brain structural abnormality in NMO. (authors)

  8. The expanded spectrum of neuromyelitis optica: evidences for a new definition

    Directory of Open Access Journals (Sweden)

    Marco A Lana-Peixoto

    2012-10-01

    Full Text Available Neuromyelitis optica (NMO has been traditionally described as the association of recurrent or bilateral optic neuritis and longitudinally extensive transverse myelitis (LETM. Identification of aquaporin-4 antibody (AQP4-IgG has deeply changed the concept of NMO. A spectrum of NMO disorders (NMOSD has been formulated comprising conditions which include both AQP4-IgG seropositivity and one of the index events of the disease (recurrent or bilateral optic neuritis and LETM. Most NMO patients harbor asymptomatic brain MRI lesions, some of them considered as typical of NMO. Some patients with aquaporin-4 autoimmunity present brainstem, hypothalamic or encephalopathy symptoms either preceding an index event or occurring isolatedly with no evidence of optic nerve or spinal involvement. On the opposite way, other patients have optic neuritis or LETM in association with typical lesions of NMO on brain MRI and yet are AQP4-IgG seronegative. An expanded spectrum of NMO disorders is proposed to include these cases.

  9. Short segment myelitis as a first manifestation of neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Huh, So-Young; Kim, Su-Hyun; Hyun, Jae-Won; Jeong, In Hye; Park, Min Su; Lee, Sang-Hyun; Kim, Ho Jin

    2017-03-01

    Some patients with neuromyelitis optica spectrum disorders (NMOSD) present with spinal cord lesions extending fewer than three vertebral segments (short transverse myelitis, STM), hindering an early diagnosis. We investigated the frequency and imaging characteristics of STM lesions in patients presenting with myelitis as an initial manifestation of NMOSD. Patients seen at three referral hospitals in Korea between June 2005 and March 2015 who met the following inclusion criteria were recruited for review: seropositivity for aquaporin-4 antibody, initial presentation with myelitis and spinal cord magnetic resonance imaging (MRI) performed within 1 month of initial myelitis onset. Of the 76 enrolled patients, 65 (85.5%) collectively had 69 longitudinally extensive transverse myelitis lesions, while the remaining 11 (14.5%) had a total of 15 STM lesions. Of the 15 STM lesions, 5 spanned 2.5 vertebral segments, 6 were continuous over two segments, 3 showed a length of 1.5 segments and 1 was confined to a single segment. On axial imaging, all of the STM lesions involved the central grey matter. These MRI findings suggested that STM does not preclude the possibility of an NMOSD diagnosis.

  10. Clinical characteristics of disabling attacks at onset in patients with neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Seok, Jin Myoung; Cho, Eun Bin; Lee, Hye Lim; Cho, Hye-Jin; Min, Ju-Hong; Lee, Kwang Ho; Kim, Byoung Joon

    2016-09-15

    Individual attacks of neuromyelitis optica (NMO) are generally severe enough to cause disability even after the onset attack. We aimed to elucidate the clinical characteristics of disabling attacks at the onset of NMO. We investigated the clinical characteristics at onset and at first relapse in patients with NMO or NMO spectrum disorder with seropositive for the anti-aquaporin-4 antibody. A disabling attack at onset (DAO) was defined as an onset attack in which, at best recovery (allowing up to one year), patients were unable to walk without assistance or were left functionally blind in at least one affected eye. Fifty-seven patients were enrolled (53 females; onset age, 41.9±14.8years). Ten patients (17.5%) had a DAO; four had become unable to walk without assistance following myelitis, and six had severe visual impairment following optic neuritis despite rescue treatments. Attack severity at nadir was the only clinical factor predicting a DAO (odds ratio, 2.120; 95% CI, 1.162-3.869; P=0.014). The use of immunosuppressants delayed the interval to the first relapse (P=0.003). Our study showed characteristics of NMO onset attacks that caused severe disability. However, no clinically modifiable factors predicted disabling attacks, except attack severity. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Circulating regulatory B cell subsets in patients with neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Han, Jinming; Sun, Li; Wang, Zhongkun; Fan, Xueli; Wang, Lifang; Song, Yang-Yang; Zhu, Jie; Jin, Tao

    2017-07-01

    This study analyzed the populations of three different subsets of regulatory B cells (Bregs) in the peripheral blood mononuclear cells (PBMCs) of patients with neuromyelitis optica spectrum disorders (NMOSDs) and explored the relationship between the changes in these subsets of Bregs and the severity of NMOSD. A total of 22 patients with relapsed NMOSDs before treatment were recruited in our study, along with 20 age and gender-matched healthy controls, from May 2015 to March 2016. The percentages and numbers for three different subsets of Bregs including the CD19 + CD24 hi CD38 hi , CD19 + CD24 hi CD27 + , and CD19 + CD5 + CD1d hi populations were evaluated in parallel by flow cytometry. Afterwards, correlations between the change of three different subsets of Bregs and disease severity were analyzed. We found significantly lower percentages of CD19 + CD24 hi CD38 hi and CD19 + CD5 + CD1d hi Bregs in NMOSDs patients than in healthy individuals. In contrast, the CD19 + CD24 hi CD27 + Bregs population was significantly higher in NMOSDs patients than in healthy individuals. However, the three different Bregs subsets showed no significant correlation with expanded disability status scale (EDSS) or annualized relapse rate (ARR). Our findings suggest that the subsets of Bregs may play complex roles in the pathogenesis of NMOSDs and are not correlated with clinical disease severity. Further insights into the potential role of subsets of Bregs could increase our basic knowledge of NMOSDs pathogenesis.

  12. Pruritus may be a common symptom related to neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    He, Zhiyong; Ren, Ming; Wang, Xiaofeng; Guo, Qifeng; Qi, Xiaokun

    2017-04-01

    To evaluate pruritus in patients with neuromyelitis optica spectrum disorders (NMOSD) and to characterize the relationship between pruritus and lesions of NMOSD. 61 patients with NMOSD were included in the study and their medical records were reviewed for pruritus, neurological symptoms and magnetic resonance imaging (MRI) images. We focused on the patients' history of pruritus, especially the severity, duration, region, and the relationship of pruritus with other symptoms of NMOSD. Of the 61 patients with NMOSD, 59 had longitudinally extensive transverse myelitis (LETM). 38 of these patients (64.4%) reported pruritus during the course of their illness, with 16 patients reporting pruritus as the initial symptoms followed by limb weakness. In 35 of 38 patients (92.1%), pruritus was located within the dermatomes innervated by the spinal nerves from the involved spinal cord. Our results show that pruritus is a common symptom of NMOSD and relates to the lesions in the spinal cord. Pruritus may indicate a new episode of myelitis in patients with NMOSD. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. The Immunology of Neuromyelitis Optica-Current Knowledge, Clinical Implications, Controversies and Future Perspectives.

    Science.gov (United States)

    Jasiak-Zatonska, Michalina; Kalinowska-Lyszczarz, Alicja; Michalak, Slawomir; Kozubski, Wojciech

    2016-03-02

    Neuromyelitis optica (NMO) is an autoimmune, demyelinating disorder of the central nervous system (CNS) with typical clinical manifestations of optic neuritis and acute transverse myelitis attacks. Previously believed to be a variant of multiple sclerosis (MS), it is now considered an independent disorder which needs to be differentiated from MS. The discovery of autoantibodies against aquaporin-4 (AQP4-IgGs) changed our understanding of NMO immunopathogenesis and revolutionized the diagnostic process. AQP4-IgG is currently regarded as a specific biomarker of NMO and NMO spectrum disorders (NMOsd) and a key factor in its pathogenesis. Nevertheless, AQP4-IgG seronegativity in 10%-25% of NMO patients suggests that there are several other factors involved in NMO immunopathogenesis, i.e., autoantibodies against aquaporin-1 (AQP1-Abs) and antibodies against myelin oligodendrocyte glycoprotein (MOG-IgGs). This manuscript reviews current knowledge about NMO immunopathogenesis, pointing out the controversial issues and showing potential directions for future research. Further efforts should be made to broaden our knowledge of NMO immunology which could have important implications for clinical practice, including the use of potential novel biomarkers to facilitate an early and accurate diagnosis, and modern treatment strategies improving long-term outcome of NMO patients.

  14. Neuromyelitis optica and multiple sclerosis: Seeing differences through optical coherence tomography

    Science.gov (United States)

    Bennett, JL; de Seze, J; Lana-Peixoto, M; Palace, J; Waldman, A; Schippling, S; Tenembaum, S; Banwell, B; Greenberg, B; Levy, M; Fujihara, K; Chan, KH; Kim, HJ; Asgari, N; Sato, DK; Saiz, A; Wuerfel, J; Zimmermann, H; Green, A; Villoslada, P

    2015-01-01

    Neuromyelitis optica (NMO) is an inflammatory autoimmune disease of the central nervous system that preferentially targets the optic nerves and spinal cord. The clinical presentation may suggest multiple sclerosis (MS), but a highly specific serum autoantibody against the astrocytic water channel aquaporin-4 present in up to 80% of NMO patients enables distinction from MS. Optic neuritis may occur in either condition resulting in neuro-anatomical retinal changes. Optical coherence tomography (OCT) has become a useful tool for analyzing retinal damage both in MS and NMO. Numerous studies showed that optic neuritis in NMO typically results in more severe retinal nerve fiber layer (RNFL) and ganglion cell layer thinning and more frequent development of microcystic macular edema than in MS. Furthermore, while patients’ RNFL thinning also occurs in the absence of optic neuritis in MS, subclinical damage seems to be rare in NMO. Thus, OCT might be useful in differentiating NMO from MS and serve as an outcome parameter in clinical studies. PMID:25662342

  15. Complexity and wide range of neuromyelitis optica spectrum disorders: more than typical manifestations

    Science.gov (United States)

    Han, Jinming; Yang, Meng-ge; Zhu, Jie; Jin, Tao

    2017-01-01

    Neuromyelitis optica (NMO), considered to be mediated by autoantibodies, often cause severely disabling disorders of the central nervous system, and predominantly cause optic nerve damage and longitudinally extensive transverse myelitis. Remarkable progress has been made in deciphering NMO pathogenesis during the past decade. In 2015, the International Panel for NMO Diagnosis proposed the unifying term “NMO spectrum disorders” (NMOSD) and the updated NMOSD criteria reflects a wide range of disease and maintains reasonable specificity. Moreover, cumulative findings have indicated that NMOSD are frequently associated with multiple autoimmune diseases, thereby presenting complex clinical symptoms that make this disease more difficult to recognize. Notably, most neurologists do not heed these symptoms or comorbid conditions in patients with NMOSD. Whereas previous reviews have focused on pathogenesis, treatment, and prognosis in NMOSD, we summarize the present knowledge with particular emphasis on atypical manifestations and autoimmune comorbidities in patients with NMOSD. Furthermore, we emphasized the identification of these atypical characteristics to enable a broader and better understanding of NMOSD, and improve early accurate diagnosis and therapeutic decision making. PMID:29118581

  16. Neuromyelitis optica and the evolving spectrum of autoimmune aquaporin-4 channelopathies: a decade later

    Science.gov (United States)

    Pittock, Sean J.; Lucchinetti, Claudia F.

    2015-01-01

    The discovery of AQP4-IgG (a pathogenic antibody that targets the astrocytic water channel aquaporin-4) as the first sensitive and specific biomarker for any inflammatory central nervous system demyelinating disease, has shifted emphasis from the oligodendrocyte and myelin to the astrocyte as a central immunopathogenic player. Neuromyelitis optica (NMO) spectrum disorders (SD) represent an evolving spectrum of IDDs extending beyond the optic nerves and spinal cord to include the brain (especially in children) and, rarely, muscle. NMOSD typical brain lesions are located in areas that highly express the target antigen, AQP4, including the circumventricular organs (accounting for intractable nausea and vomiting) and the diencephalon (accounting for sleep disorders, endocrinopathies, and syndrome of inappropriate antidiuresis). Magnetic resonance imaging (MRI) brain abnormalities fulfill Barkoff criteria for multiple sclerosis in up to 10% of patients. As the spectrum broadens, the importance of highly specific assays that detect pathogenic AQP4-IgG targeting extracellular epitopes of AQP4 cannot be overemphasized. The rapid evolution of our understanding of the immunobiology of AQP4 autoimmunity necessitates continuing revision of NMOSD diagnostic criteria. Here, we describe scientific advances that have occurred since the discovery of NMO-IgG in 2004 and review novel targeted immunotherapies. We also suggest that NMOSDs should now be considered under the umbrella term autoimmune aquaporin-4 channelopathy. PMID:26096370

  17. Neuromyelitis optica accompanied by nephrotic syndrome and autoimmune-related pancytopenia.

    Science.gov (United States)

    ZhangBao, Jingzi; Zhou, Lei; Lu, Jiahong; Xi, Jianying; Zhao, Chongbo; Quan, Chao

    2016-05-01

    Neuromyelitis optica (NMO) associated with nephrotic syndrome and autoimmune-related pancytopenia has not been reported previously. We report herein a young woman who initially presented with bilateral blurring of vision and numbness in her hands. MRI disclosed multiple white matter lesions and a long cervical spinal cord lesion extending to the medulla oblongata. Serum aquaporin-4 antibody was positive and the patient was diagnosed with NMO. While in the hospital, she presented with hypoproteinemia and heavy proteinuria, meeting the diagnostic criteria of nephrotic syndrome. After high-dose methylprednisolone treatment, her vision improved significantly and urine protein quantity decreased. However, the patient subsequently developed severe pancytopenia with a positive Coombs' test. Thrombocytopenia finally led to uncontrollable gastrointestinal bleeding as the direct cause of the patient's death. This case illustrates the extremely rare condition of concurrence of NMO, nephrotic syndrome, and autoimmune pancytopenia in one patient, which suggests the involvement of organs beyond the central nervous system in NMO spectrum disorders. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Optical Coherence Tomography and Magnetic Resonance Imaging in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder.

    Science.gov (United States)

    Manogaran, Praveena; Hanson, James V M; Olbert, Elisabeth D; Egger, Christine; Wicki, Carla; Gerth-Kahlert, Christina; Landau, Klara; Schippling, Sven

    2016-11-15

    Irreversible disability in multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) is largely attributed to neuronal and axonal degeneration, which, along with inflammation, is one of the major pathological hallmarks of these diseases. Optical coherence tomography (OCT) is a non-invasive imaging tool that has been used in MS, NMOSD, and other diseases to quantify damage to the retina, including the ganglion cells and their axons. The fact that these are the only unmyelinated axons within the central nervous system (CNS) renders the afferent visual pathway an ideal model for studying axonal and neuronal degeneration in neurodegenerative diseases. Structural magnetic resonance imaging (MRI) can be used to obtain anatomical information about the CNS and to quantify evolving pathology in MS and NMOSD, both globally and in specific regions of the visual pathway including the optic nerve, optic radiations and visual cortex. Therefore, correlations between brain or optic nerve abnormalities on MRI, and retinal pathology using OCT, may shed light on how damage to one part of the CNS can affect others. In addition, these imaging techniques can help identify important differences between MS and NMOSD such as disease-specific damage to the visual pathway, trans-synaptic degeneration, or pathological changes independent of the underlying disease process. This review focuses on the current knowledge of the role of the visual pathway using OCT and MRI in patients with MS and NMOSD. Emphasis is placed on studies that employ both MRI and OCT to investigate damage to the visual system in these diseases.

  19. Plasma complement biomarkers distinguish multiple sclerosis and neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Hakobyan, Svetlana; Luppe, Sebastian; Evans, David Rs; Harding, Katharine; Loveless, Samantha; Robertson, Neil P; Morgan, B Paul

    2017-06-01

    Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) are autoimmune inflammatory demyelinating diseases of the central nervous system. Although distinguished by clinicoradiological and demographic features, early manifestations can be similar complicating management. Antibodies against aquaporin-4 support the diagnosis of NMOSD but are negative in some patients. Therefore, there is unmet need for biomarkers that enable early diagnosis and disease-specific intervention. We investigated whether plasma complement proteins are altered in MS and NMOSD and provide biomarkers that distinguish these diseases. Plasma from 54 NMOSD, 40 MS and 69 control donors was tested in multiplex assays measuring complement activation products and proteins. Using logistic regression, we tested whether combinations of complement analytes distinguished NMOSD from controls and MS. All activation products were elevated in NMOSD compared to either control or MS. Four complement proteins (C1inh, C1s, C5 and FH) were higher in NMOSD compared to MS or controls. A model comprising C1inh and terminal complement complex (TCC) distinguished NMOSD from MS (area under the curve (AUC): 0.98), while C1inh and C5 distinguished NMOSD from controls (AUC: 0.94). NMOSD is distinguished from MS by plasma complement biomarkers. Selected complement analytes enable differential diagnosis. Findings support trials of anti-complement therapies in NMOSD.

  20. Evaluation of Clinical Interest of Anti-Aquaporin-4 Autoantibody Followup in Neuromyelitis Optica

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste Chanson

    2013-01-01

    Full Text Available Neuromyelitis optica (NMO is an autoimmune disease in which a specific biomarker named NMO-IgG and directed against aquaporin-4 (AQP4 has been found. A correlation between disease activity and anti-AQP4 antibody (Ab serum concentration or complement-mediated cytotoxicity has been reported, but the usefulness of longitudinal evaluation of these parameters remains to be evaluated in actual clinical practice. Thirty serum samples from 10 NMO patients positive for NMO-IgG were collected from 2006 to 2011. Anti-AQP4 Ab serum concentration and complement-mediated cytotoxicity were measured by flow cytometry using two quantitative cell-based assays (CBA and compared with clinical parameters. We found a strong correlation between serum anti-AQP4 Ab concentration and complement-mediated cytotoxicity (P<0.0001. Nevertheless, neither relapse nor worsening of impairment level was closely associated with a significant increase in serum Ab concentration or cytotoxicity. These results suggest that complement-mediated serum cytotoxicity assessment does not provide extra insight compared to anti-AQP4 Ab serum concentration. Furthermore, none of these parameters appears closely related to disease activity and/or severity. Therefore, in clinical practice, serum anti-AQP4 reactivity seems not helpful as a predictive biomarker in the followup of NMO patients as a means of predicting the onset of a relapse and adapting the treatment accordingly.

  1. Cognitive impairment differs between neuromyelitis optica spectrum disorder and multiple sclerosis.

    Science.gov (United States)

    Kim, Su-Hyun; Kwak, Kichang; Jeong, In Hye; Hyun, Jae-Won; Jo, Hyo-Jin; Joung, AeRan; Yu, Eun-Seung; Kim, Ji-Hee; Lee, Sang Hyun; Yun, Sooin; Joo, Jungnam; Lee, Dong-Kyun; Lee, Jong-Min; Kim, Ho Jin

    2016-12-01

    To compare the frequency and pattern of cognitive impairment (CI) between patients with neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS). A total of 82 NMOSD patients, 58 MS patients, and 45 healthy controls (HCs) underwent a neuropsychological assessment. CI was observed in 29% of NMOSD and 50% of MS patients (p < 0.001); CI was considered present if a patient scored lower than the fifth percentile compared with HCs in at least three domains. A lower frequency of CI was consistently found when CI was indicated by at least two failed tests (p < 0.001). MS patients performed worse than did NMOSD patients on verbal learning and verbal and visual memory tests. Levels of education and depression and the interval from disease onset to treatment were associated with a negative influence on cognition in patients with NMOSD. CI in patients with NMOSD may be not as common as in patients with MS. MS patients exhibited severe impairment, particularly on learning and memory tests, compared with NMOSD patients. Differential prevalence and patterns of CI between NMOSD and MS patients suggest that the two diseases have different mechanisms of brain injury. © The Author(s), 2016.

  2. Detection and clinical value of NMO-IgG in neuromyelitis optica

    Directory of Open Access Journals (Sweden)

    De-hui HUANG

    2014-09-01

    Full Text Available Neuromyelitis optica (NMO is an inflammatory demyelinating disease of the central nervous system (CNS of autoimmune etiology which predominantly affects the optic nerves and spinal cord. In 2004, a highly specific serum antibody, NMO-IgG, was found in the sera of NMO patients. Subsequently, the target antigen of NMO-IgG was identified as aquaporin 4 (AQP4, a water channel densely expressed in optic nerves, spinal cord and area around cerebral ventricles. NMO-IgG/AQP4 antibody has demonstrated extreme importance for the diagnosis and differential diagnosis, the evaluation of disease activity, therapeutic effect and prognosis of NMO. In recent years, different techniques have been used to examine NMO-IgG in serum and cerebrospinal fluid, including tissue-based, cell-based and protein-based assays. In this review, the authors give an overview of the tests currently available for the detection of NMO-IgG and their clinical significance. doi: 10.3969/j.issn.1672-6731.2014.09.003

  3. The Contribution of Optical Coherence Tomography in Neuromyelitis Optica Spectrum Disorders

    Science.gov (United States)

    Mateo, Javier; Esteban, Olivia; Martínez, Mireya; Grzybowski, Andrzej; Ascaso, Francisco Javier

    2017-01-01

    Neuromyelitis optica spectrum disorders (NMOSD) comprises a group of central nervous system disorders of inflammatory autoimmune origin that mainly affect the optic nerves and the spinal cord and can cause severe visual and general disability. The clinical signs are similar to those of multiple sclerosis (MS), with the result that it is often difficult to differentiate between the two, thus leading to misdiagnosis. As the treatment and prognosis of NMOSD and MS are different, it is important to make an accurate and early diagnosis of NMOSD. Optical coherence tomography (OCT) is a non-invasive technique that enables a quantitative study of the changes that the optic nerve and the macula undergo in several neurodegenerative diseases. Many studies have shown that some of these changes, such as retinal nerve fiber layer thinning or microcystic macular edema, can be related to alterations in the brain due to neurodegenerative disorders. The purpose of this mini-review is to show how OCT can be useful for the diagnosis of NMOSD and follow-up of affected patients, as well as for the differential diagnosis with MS. PMID:29085325

  4. Lesions of the posterior limb of the internal capsule in neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Long, Youming; Wu, Linzhan; Zhong, Rong; Ouyang, Xiaoming; Liang, Junyan; Gao, Cong; Chen, Xiaohui; Qiu, Wei; Chang, Yanyu; Wang, Zhanhang; Ye, Jinlong

    2017-05-01

    Posterior limb of the internal capsule lesions (PLICL) are one of the MRI features of neuromyelitis optica spectrum disorder (NMOSD). However, there is no evidence that such lesions are pathogenically related to NMOSD. We retrospectively analyzed features of PLICL in NMOSD, and other central nervous system inflammatory disorders, in 561 patients. We also examined the pathological samples of six patients. Of the 561 patients investigated, PLICL were found in 65 patients (11.6%). Lesions were bilateral in 26 cases (40%) and unilateral in 39 cases (60%). Unilateral lesions were mainly located on the left side (74.3%, 29/39). Of the 65 patients with PLICL, 46 patients had NMOSD (70.8%) and were positive for anti-aquaporin (AQP4-IgG), four had NMOSD (6.2%) and were AQP4-IgG negative, 10 patients had multiple sclerosis (MS), three patients had NMDAR encephalitis, and two had autoimmune meningoencephalitis. Of the six patients whose pathological samples were evaluated, all had PLICL and were negative for AQP4-IgG, and none had pathological NMOSD lesion features. These cases included three patients with multiple sclerosis, one with anti-N-methyl-D-aspartate receptor encephalitis, and two with autoimmune meningoencephalitis. In conclusion, PLICL are found not only in patients with NMOSD, but also in MS and other disorders.

  5. Application of diffusional kurtosis imaging to detect occult brain damage in multiple sclerosis and neuromyelitis optica.

    Science.gov (United States)

    Qian, Wenshu; Chan, Koon Ho; Hui, Edward S; Lee, Chi Yan; Hu, Yong; Mak, Henry Ka-Fung

    2016-11-01

    Multiple sclerosis (MS) and neuromyelitis optica (NMO) are two common types of inflammatory demyelinating disease of the central nervous system. Early distinction of NMO from MS is crucial but quite challenging. In this study, 13 NMO spectrum disorder patients (Expanded Disability Status Scale (EDSS) of 3.0 ± 1.7, ranging from 2 to 6.5; disease duration of 5.3 ± 4.7 years), 17 relapsing-remitting MS patients (EDSS of 2.6 ± 1.4, ranging from 1 to 5.5; disease duration of 7.9 ± 7.8 years) and 18 healthy volunteers were recruited. Diffusional kurtosis imaging was employed to discriminate NMO and MS patients at the early or stable stage from each other, and from healthy volunteers. The presence of alterations in diffusion and diffusional kurtosis metrics in normal-appearing white matter (NAWM) and diffusely increased mean diffusivity (MD) in the cortical normal-appearing gray matter (NAGM) favors the diagnosis of MS rather than NMO. Meanwhile, normal diffusivities and kurtosis metrics in all NAWM as well as increases in MD in the frontal and temporal NAGM suggest NMO. Our results suggest that diffusion and diffusional kurtosis metrics may well aid in discriminating the two diseases. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Treatment of neuromyelitis optica: state-of-the-art and emerging therapies

    Science.gov (United States)

    Papadopoulos, Marios C.; Bennett, Jeffrey L.; Verkman, Alan S.

    2014-01-01

    Neuromyelitis optica (NMO) is an autoimmune disease of the CNS that is characterized by inflammatory demyelinating lesions in the spinal cord and optic nerve, potentially leading to paralysis and blindness. NMO can usually be distinguished from multiple sclerosis (MS) on the basis of seropositivity for IgG antibodies against the astrocytic water channel aquaporin-4 (AQP4). Differentiation from MS is crucial, because some MS treatments can exacerbate NMO. NMO pathogenesis involves AQP4-IgG antibody binding to astrocytic AQP4, which causes complement-dependent cytotoxicity and secondary inflammation with granulocyte and macrophage infiltration, blood–brain barrier disruption and oligodendrocyte injury. Current NMO treatments include general immunosuppressive agents, B-cell depletion, and plasma exchange. Therapeutic strategies targeting complement proteins, the IL-6 receptor, neutrophils, eosinophils and CD19—all initially developed for other indications—are under clinical evaluation for repurposing for NMO. Therapies in the preclinical phase include AQP4-blocking antibodies and AQP4-IgG enzymatic inactivation. Additional, albeit currently theoretical, treatment options include reduction of AQP4 expression, disruption of AQP4 orthogonal arrays, enhancement of complement inhibitor expression, restoration of the blood–brain barrier, and induction of immune tolerance. Despite the many therapeutic options in NMO, no controlled clinical trials in patients with this condition have been conducted to date. PMID:25112508

  7. Differentiating neuromyelitis optica from other causes of longitudinally extensive transverse myelitis on spinal magnetic resonance imaging

    Science.gov (United States)

    Pekcevik, Yeliz; Mitchell, Charles H; Mealy, Maureen A; Orman, Gunes; Lee, In H; Newsome, Scott D; Thompson, Carol B; Pardo, Carlos A; Calabresi, Peter A; Levy, Michael; Izbudak, Izlem

    2016-01-01

    Background Although spinal magnetic resonance imaging (MRI) findings of neuromyelitis optica (NMO) have been described, there is limited data available that help differentiate NMO from other causes of longitudinally extensive transverse myelitis (LETM). Objective To investigate the spinal MRI findings of LETM that help differentiate NMO at the acute stage from multiple sclerosis (MS) and other causes of LETM. Methods We enrolled 94 patients with LETM into our study. Bright spotty lesions (BSL), the lesion distribution and location were evaluated on axial T2-weighted images. Brainstem extension, cord expansion, T1 darkness and lesion enhancement were noted. We also reviewed the brain MRI of the patients during LETM. Results Patients with NMO had a greater amount of BSL and T1 dark lesions (p < 0.001 and 0.003, respectively). The lesions in NMO patients were more likely to involve greater than one-half of the spinal cord’s cross-sectional area; to enhance and be centrally-located, or both centrally- and peripherally-located in the cord. Of the 62 available brain MRIs, 14 of the 27 whom were NMO patients had findings that may be specific to NMO. Conclusions Certain spinal cord MRI features are more commonly seen in NMO patients and so obtaining brain MRI during LETM may support diagnosis. PMID:26209588

  8. Risk of venous thromboembolism in neuromyelitis optica patients hospitalized for acute relapse.

    Science.gov (United States)

    Farber, Rebecca Straus; Gross, Robert; Zakin, Elina; Fabian, Michelle

    2017-06-01

    Neuromyelitis optica spectrum disorder (NMOSD) patients may be at increased risk of venous thromboembolism (VTE) not only due to ambulatory disability but also due to systemic autoimmune and inflammatory mechanisms altering the hemostatic balance. To compare the risk of VTE in NMOSD versus multiple sclerosis (MS) patients hospitalized for acute relapses. Hospital admissions for MS or NMOSD exacerbations were retrospectively identified. Demographics and medical history were recorded. The relationship between visit diagnosis and presence of VTE within 6 weeks of relapse onset was assessed by univariate logistic regression. A multivariate model evaluated the relationship between diagnosis, age, race, gender, body mass index (BMI), disease modifying therapy use, oral corticosteroid use, oral contraceptive use, smoking, length of stay (LOS), and ambulatory status on VTE risk. A total of 30 NMOSD patients had 55 hospitalizations; 179 MS patients had 264 hospitalizations. Six NMOSD patients and one MS patient had VTE. NMOSD visits compared to MS visits had an odds ratio (OR) of VTE of 32.2 ( p = 0.002). NMOSD was more likely to be associated with VTE (OR = 17.4; p = 0.01) controlling for age, LOS, and ambulatory disability. NMOSD may be a risk factor for VTE. Larger prospective studies are required to confirm this risk and determine implications for prophylaxis.

  9. Comparative molecular dynamics study of neuromyelitis optica-immunoglobulin G binding to aquaporin-4 extracellular domains.

    Science.gov (United States)

    Alberga, Domenico; Trisciuzzi, Daniela; Lattanzi, Gianluca; Bennett, Jeffrey L; Verkman, Alan S; Mangiatordi, Giuseppe Felice; Nicolotti, Orazio

    2017-08-01

    Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system in which most patients have serum autoantibodies (called NMO-IgG) that bind to astrocyte water channel aquaporin-4 (AQP4). A potential therapeutic strategy in NMO is to block the interaction of NMO-IgG with AQP4. Building on recent observation that some single-point and compound mutations of the AQP4 extracellular loop C prevent NMO-IgG binding, we carried out comparative Molecular Dynamics (MD) investigations on three AQP4 mutants, TP 137-138 AA, N 153 Q and V 150 G, whose 295-ns long trajectories were compared to that of wild type human AQP4. A robust conclusion of our modeling is that loop C mutations affect the conformation of neighboring extracellular loop A, thereby interfering with NMO-IgG binding. Analysis of individual mutations suggested specific hydrogen bonding and other molecular interactions involved in AQP4-IgG binding to AQP4. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Neuromyelitis optica spectrum disorders: long-term safety and efficacy of rituximab in Caucasian patients.

    Science.gov (United States)

    Radaelli, M; Moiola, L; Sangalli, F; Esposito, F; Barcella, V; Ferrè, L; Rodegher, M; Colombo, B; Fazio, R; Martinelli, V; Comi, G

    2016-04-01

    To assess the long-term benefit-risk profile of repeated courses of rituximab in Caucasian patients affected by neuromyelitis optica (NMO) and related disorders, in everyday clinical practice. This is a prospective observational study performed at San Raffaele Hospital, Milan, Italy. From February 2006, we recruited 21 patients affected by NMO and NMO spectrum of disorders (NMOSD) whom underwent at least one cycle of intravenous (i.v.) rituximab and then were followed for at least 2 years. At a mean follow-up time of 48 months, we observed a significant reduction of the annualized relapse rate (ARR), from 2.0 to 0.16 (p < 0.01); and of the median Expanded Disability Status Scale (EDSS), from 5.5 to 4.0 (p < 0.013). There were 12 patients (57%) who remained disease free during the follow-up period. Five patients (24%) reported mild hematological adverse events. Serious infectious adverse events were reported by another four patients: These were all wheelchair bound at the beginning of their rituximab treatment. A fixed treatment scheme of rituximab, with re-treatment every 6 months, was efficacious for NMO and NMOSD, with a good safety profile; however, to obtain an even better benefit-risk ratio, close monitoring of CD19(+) B cells should be performed before the re-treatment of patients with high-level disability, concomitant leukopenia and hypogammaglobulinemia. © The Author(s), 2015.

  11. Assessment of Optic Nerve Impairment in Patients with Neuromyelitis Optica by MR Diffusion Tensor Imaging.

    Directory of Open Access Journals (Sweden)

    Zhiye Chen

    Full Text Available Diffusion tensor imaging (DTI has been used for the evaluation of the white matter integrity. In this study, we evaluated optic nerve impairment in patients with neuromyelitis optica (NMO using DTI.Optic nerve DTI were performed on 28 NMO patients and 38 normal controls. Fractional anisotropy (FA values were measured in the anterior, middle, and posterior parts of the intraorbital optic nerve segment. For the posterior intraorbital optic nerve, FA values of BI (0.20±0.07, MI (0.24±0.16, and NA (0.25±0.14 decreased significantly compared with that of NC (0.43±0.07 (P<0.05, and ROC analysis demonstrated that the area under the curve (AUC measurements for BI vs. NC, MI vs. NC, NA vs. NC, and NMO (including BI, MI, and NA vs. NC were 0.99, 0.93, 0.88, and 0.96, respectively. The corresponding diagnostic sensitivities of ROC analysis were 100%, 80%, 80%, and 91%; and the specificities were 93%, 97%, 91%, and 93%.Decreased FA value in the intraorbital optic nerve, especially in the posterior part of the nerve, was demonstrated as a characteristic MR feature for NMO-related optic nerve impairment.

  12. Cognitive dysfunction in adult patients with neuromyelitis optica: a systematic review and meta-analysis.

    Science.gov (United States)

    Meng, Hao; Xu, Jun; Pan, Chenling; Cheng, Jiaxing; Hu, Yue; Hong, Yin; Shen, Yuehai; Dai, Hua

    2017-08-01

    The objective of this study was to investigate cognitive dysfunction in 24-60-year-old neuromyelitis optica (NMO) patients, demographically matched healthy subjects, and MS patients. We conducted a comprehensive literature review of the PubMed, Medline, EMBASE, CNKI, Wan Fang Date, Web of Science, and Cochrane Library databases from inception to May 2016 for case-control studies that reported cognitive test scores in NMO patients, healthy subjects, and MS patients. Outcome measures were cognitive function evaluations, including performance on attention, language, memory, information processing speed, and executive function tests. The meta-analysis included eight studies. NMO patients performed significantly worse on attention (P < 0.00001), language (P = 0.00008), memory (P = 0.00004), information processing speed (P < 0.00001), and executive function tests (P = 0.00009) than healthy subjects. There were no significant differences in performance between NMO patients and MS patients on these tests. This meta-analysis indicates that NMO patients aged 24-60 years have significantly worse cognitive performance than demographically matched healthy subjects. However, this was comparable to the performance of demographically matched MS patients. There is a need for further rigorous randomized controlled trials with focus on elucidating the underlying mechanism of cognitive dysfunction in NMO patients.

  13. Complement-independent retinal pathology produced by intravitreal injection of neuromyelitis optica immunoglobulin G

    Directory of Open Access Journals (Sweden)

    Christian M. Felix

    2016-10-01

    Full Text Available Abstract Background Neuromyelitis optica (NMO, an autoimmune inflammatory disease of the central nervous system, is often associated with retinal abnormalities including thinning of the retinal nerve fiber layer and microcystic changes. Here, we demonstrate that passive transfer of an anti-aquaporin-4 autoantibody (AQP4-IgG produces primary retinal pathology. Methods AQP4-IgG was delivered to adult rat retinas by intravitreal injection. Rat retinas and retinal explant cultures were assessed by immunofluorescence. Results Immunofluorescence showed AQP4-IgG deposition on retinal Müller cells, with greatly reduced AQP4 expression and increased glial fibrillary acidic protein by 5 days. There was mild retinal inflammation with microglial activation but little leukocyte infiltration and loss of retinal ganglion cells by 30 days with thinning of the ganglion cell complex. Interestingly, the loss of AQP4 was complement independent as seen in cobra venom factor-treated rats and in normal rats administered a mutated AQP4-IgG lacking complement effector function. Exposure of ex vivo retinal cultures to AQP4-IgG produced a marked reduction in AQP4 expression by 24 h, which was largely prevented by inhibitors of endocytosis or lysosomal acidification. Conclusions Passive transfer of AQP4-IgG results in primary, complement-independent retinal pathology, which might contribute to retinal abnormalities seen in NMO patients.

  14. Imbalance in multiple sclerosis and neuromyelitis optica: association with deep sensation disturbance.

    Science.gov (United States)

    Demura, Yutaka; Kinoshita, Masako; Fukuda, Osamu; Nose, Shouzou; Nakano, Hitoshi; Juzu, Akira; Murase, Nagako; Yamamoto, Kenji

    2016-12-01

    Abnormality in balance is one of the most important causes of gait disturbance which has a direct impact to disability and medical cost in multiple sclerosis (MS) and neuromyelitis optica (NMO). However, characteristics of imbalance in these two diseases have not been fully elucidated. The aim of this study was to evaluate the degree and features of imbalance using stabilography, the degree of deep sensation disturbance using tibial nerve somatosensory evoked potentials (SEP), and their association with clinical impairment, in patients with MS and NMO. Seven NMO patients and seven MS patients with balance disturbance were examined. The relationship among stabilography measurements representing the degree and features of imbalance, height-adjusted P38 peak latency of SEP, and neurological functional disability, were analyzed. Stabilography evaluation showed a significantly severer degree of imbalance in NMO than in MS. Romberg quotient of the patients with brainstem lesions was significantly larger than those without them. In all patients, length of excursion per second significantly correlated positively with anterio-posterior-axis power spectra at intermediate frequency band. In all patients and in NMO, P38 peak latency adjusted by height significantly correlated positively with anterio-posterior-axis power spectra at intermediate frequency band. These findings suggest that the degree of imbalance of MS and NMO possibly correlate with deep sensation disturbance, which could be evaluated by anterio-posterior-axis power spectra at intermediate frequency band by stabilography. Severer imbalance in NMO than MS may be associated with the severe longitudinally extensive spinal cord lesions.

  15. Gender effect on neuromyelitis optica spectrum disorder with aquaporin4-immunoglobulin G.

    Science.gov (United States)

    Kim, Sung-Min; Waters, Patrick; Woodhall, Mark; Kim, Yoo-Jin; Kim, Jin-Ah; Cheon, So Young; Lee, Sehoon; Jo, Seong Rae; Kim, Dong Gun; Jung, Kyeong Cheon; Lee, Kwang-Woo; Sung, Jung-Joon; Park, Kyung Seok

    2017-07-01

    Neuromyelitis optica spectrum disorder with aquaporin4-immunoglobulin G (NMOSD-AQP4) is an inflammatory disease characterised by a high female predominance. However, the effect of gender in patients with NMOSD-AQP4 has not been fully evaluated. The aim of this study was to determine the effect of gender in clinical manifestations and prognosis of patients with NMOSD-AQP4. The demographics, clinical and radiological characteristics, pattern reversal visual evoked potential (VEP) test results, and prognosis of 102 patients (18 males) with NMOSD-AQP4 were assessed. Male patients had a higher age at onset (48.7 vs 41 years, p = 0.037) and less optic neuritis as the onset attack (17% vs 44%, p = 0.026), higher tendency to manifest as isolated myelitis over the follow-up period (67% vs 28%, p = 0.005), fewer optic neuritis attacks per year (0.08 vs 0.27, p gender was significantly associated with the absence of optic neuritis attacks over the follow-up period independent of their age of onset. In NMOSD-AQP4 patients, gender impacts on disease onset age and site of attack. This may be an important clue in identifying NMOSD-AQP4 patients with limited manifestations as well as in predicting their clinical courses.

  16. Abnormal brain function in neuromyelitis optica: A fMRI investigation of mPASAT.

    Science.gov (United States)

    Wang, Fei; Liu, Yaou; Li, Jianjun; Sondag, Matthew; Law, Meng; Zee, Chi-Shing; Dong, Huiqing; Li, Kuncheng

    2017-10-01

    Cognitive impairment with the Neuromyelitis Optica (NMO) patients is debated. The present study is to study patterns of brain activation in NMO patients during a pair of task-related fMRI. We studied 20 patients with NMO and 20 control subjects matched for age, gender, education and handedness. All patients with NMO met the 2006 Wingerchuk diagnostic criteria. The fMRI paradigm included an auditory attention monitoring task and a modified version of the Paced Auditory Serial Addition Task (mPASAT). Both tasks were temporally and spatially balanced, with the exception of task difficulty. In mPASAT, Activation regions in control subjects included bilateral superior temporal gyri (BA22), left inferior frontal gyrus (BA45), bilateral inferior parietal lobule (BA7), left cingulate gyrus (BA32), left insula (BA13), and cerebellum. Activation regions in NMO patients included bilateral superior temporal gyri (BA22), left inferior frontal gyrus (BA9), right cingulate gyrus (BA32), right inferior parietal gyrus (BA40), left insula (BA13) and cerebellum. Some dispersed cognition related regions are greater in the patients. The present study showed altered cerebral activation during mPASAT in patients with NMO relative to healthy controls. These results are speculated to provide further evidence for brain plasticity in patients with NMO. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Brain parenchymal damage in neuromyelitis optica spectrum disorder - A multimodal MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Pache, F.; Paul, F. [Max Delbrueck Center for Molecular Medicine and Charite Universitaetsmedizin Berlin, NeuroCure Clinical Research Center and Experimental and Clinical Research Center, Berlin (Germany); Charite Universitaetsmedizin Berlin, Department of Neurology, Berlin (Germany); Zimmermann, H.; Lacheta, A.; Papazoglou, S.; Kuchling, J.; Wuerfel, J.; Brandt, A.U. [Max Delbrueck Center for Molecular Medicine and Charite Universitaetsmedizin Berlin, NeuroCure Clinical Research Center and Experimental and Clinical Research Center, Berlin (Germany); Finke, C. [Charite Universitaetsmedizin Berlin, Department of Neurology, Berlin (Germany); Humboldt-Universitaet zu Berlin, Berlin School of Mind and Brain, Berlin (Germany); Hamm, B. [Charite Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Ruprecht, K. [Charite Universitaetsmedizin Berlin, Department of Neurology, Berlin (Germany); Scheel, M. [Max Delbrueck Center for Molecular Medicine and Charite Universitaetsmedizin Berlin, NeuroCure Clinical Research Center and Experimental and Clinical Research Center, Berlin (Germany); Charite Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany)

    2016-12-15

    To investigate different brain regions for grey (GM) and white matter (WM) damage in a well-defined cohort of neuromyelitis optica spectrum disorder (NMOSD) patients and compare advanced MRI techniques (VBM, Subcortical and cortical analyses (Freesurfer), and DTI) for their ability to detect damage in NMOSD. We analyzed 21 NMOSD patients and 21 age and gender matched control subjects. VBM (GW/WM) and DTI whole brain (TBSS) analyses were performed at different statistical thresholds to reflect different statistical approaches in previous studies. In an automated atlas-based approach, Freesurfer and DTI results were compared between NMOSD and controls. DTI TBSS and DTI atlas based analysis demonstrated microstructural impairment only within the optic radiation or in regions associated with the optic radiation (posterior thalamic radiation p < 0.001, 6.9 % reduction of fractional anisotropy). VBM demonstrated widespread brain GM and WM reduction, but only at exploratory statistical thresholds, with no differences remaining after correction for multiple comparisons. Freesurfer analysis demonstrated no group differences. NMOSD specific parenchymal brain damage is predominantly located in the optic radiation, likely due to a secondary degeneration caused by ON. In comparison, DTI appears to be the most reliable and sensitive technique for brain damage detection in NMOSD. (orig.)

  18. Multifrequency magnetic resonance elastography of the brain reveals tissue degeneration in neuromyelitis optica spectrum disorder

    Energy Technology Data Exchange (ETDEWEB)

    Streitberger, Kaspar-Josche [Charite - Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Charite - Universitaetsmedizin Berlin, Department of Neurology with Experimental Neurology, Berlin (Germany); Fehlner, Andreas; Sack, Ingolf [Charite - Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Pache, Florence [Charite - Universitaetsmedizin Berlin, Department of Neurology with Experimental Neurology, Berlin (Germany); Charite - Universitaetsmedizin Berlin, NeuroCure Clinical Research Center, Berlin (Germany); Lacheta, Anna; Papazoglou, Sebastian; Brandt, Alexander [Charite - Universitaetsmedizin Berlin, NeuroCure Clinical Research Center, Berlin (Germany); Bellmann-Strobl, Judith [Max Delbrueck Center for Molecular Medicine and Charite - Universitaetsmedizin Berlin, Experimental and Clinical Research Center, Berlin (Germany); Ruprecht, Klemens [Charite - Universitaetsmedizin Berlin, Department of Neurology with Experimental Neurology, Berlin (Germany); Braun, Juergen [Charite - Universitaetsmedizin Berlin, Institute of Medical Informatics, Berlin (Germany); Paul, Friedemann [Charite - Universitaetsmedizin Berlin, Department of Neurology with Experimental Neurology, Berlin (Germany); Charite - Universitaetsmedizin Berlin, NeuroCure Clinical Research Center, Berlin (Germany); Max Delbrueck Center for Molecular Medicine and Charite - Universitaetsmedizin Berlin, Experimental and Clinical Research Center, Berlin (Germany); Wuerfel, Jens [Charite - Universitaetsmedizin Berlin, NeuroCure Clinical Research Center, Berlin (Germany); Max Delbrueck Center for Molecular Medicine and Charite - Universitaetsmedizin Berlin, Experimental and Clinical Research Center, Berlin (Germany); Medical Image Analysis Center (MIAC AG), Basel (Switzerland)

    2017-05-15

    Application of multifrequency magnetic resonance elastography (MMRE) of the brain parenchyma in patients with neuromyelitis optica spectrum disorder (NMOSD) compared to age matched healthy controls (HC). 15 NMOSD patients and 17 age- and gender-matched HC were examined using MMRE. Two three-dimensional viscoelastic parameter maps, the magnitude G* and phase angle φ of the complex shear modulus were reconstructed by simultaneous inversion of full wave-field data in 1.9-mm isotropic resolution at 7 harmonic drive frequencies from 30 to 60 Hz. In NMOSD patients, a significant reduction of G* was observed within the white matter fraction (p = 0.017), predominantly within the thalamic regions (p = 0.003), compared to HC. These parameters exceeded the reduction in brain volume measured in patients versus HC (p = 0.02 whole-brain volume reduction). Volumetric differences in white matter fraction and the thalami were not detectable between patients and HC. However, phase angle φ was decreased in patients within the white matter (p = 0.03) and both thalamic regions (p = 0.044). MMRE reveals global tissue degeneration with accelerated softening of the brain parenchyma in patients with NMOSD. The predominant reduction of stiffness is found within the thalamic region and related white matter tracts, presumably reflecting Wallerian degeneration. (orig.)

  19. MRI abnormalities and related risk factors of the brain in patients with neuromyelitis optica

    International Nuclear Information System (INIS)

    Xiao Hui; Ma Lin; Lou Xin; Cai Youquan; Wang Yulin; Wang Yan; Wu Lei; Wu Weiping

    2011-01-01

    Objective: To investigate the MRI features of the brain in patients with neuromyelitis optica (NMO), and to evaluate the correlation between the brain abnormalities and related risk factors. Methods: Fifty-four patients with definite NMO according to 2006 Wingerchuk diagnosis criteria were enrolled in this study. MRI scanning of the brain was performed in these patients. Distribution and signal features of all the lesions were analyzed. A Logistic regression analysis was used to evaluate the risk factors of brain abnormalities. Results: Twenty-four NMO patients (44.4%) showed unremarkable findings and thirty (55.6%) showed abnormalities on brain MRI. Multiple and non-specific small lesions in the subcortical white matter and grey-white matter junction were the most frequent abnormalities on brain MRI (13/30, 43.3%). Typical lesion locations included corpus callosum, subependyma of ventricles, hypothalamus and brain stem. The lesions showed punctate, patchy and linear abnormal signals. Post-contrast MRI showed no abnormal enhancement in 16 cases. Logistic regression analysis showed that coexisting autoimmune disease or infection. history had correlations with abnormalities of the brain on MRI (OR=3.519, P<0.05). Conclusions: There was a high incidence of brain abnormalities in NMO. Subependymal white matter, corpus callosum, hypothalamus and brain stem were often involved in NMO. NMO patients with coexisting autoimmune disease and infection history had higher risk of brain abnormalities. (authors)

  20. European ancestry predominates in neuromyelitis optica and multiple sclerosis patients from Brazil.

    Directory of Open Access Journals (Sweden)

    Doralina Guimarães Brum

    Full Text Available BACKGROUND: Neuromyelitis optica (NMO is considered relatively more common in non-Whites, whereas multiple sclerosis (MS presents a high prevalence rate, particularly in Whites from Western countries populations. However, no study has used ancestry informative markers (AIMs to estimate the genetic ancestry contribution to NMO patients. METHODS: Twelve AIMs were selected based on the large allele frequency differences among European, African, and Amerindian populations, in order to investigate the genetic contribution of each ancestral group in 236 patients with MS and NMO, diagnosed using the McDonald and Wingerchuck criteria, respectively. All 128 MS patients were recruited at the Faculty of Medicine of Ribeirão Preto (MS-RP, Southeastern Brazil, as well as 108 healthy bone marrow donors considered as healthy controls. A total of 108 NMO patients were recruited from five Neurology centers from different Brazilian regions, including Ribeirão Preto (NMO-RP. PRINCIPAL FINDINGS: European ancestry contribution was higher in MS-RP than in NMO-RP (78.5% vs. 68.7% patients. In contrast, African ancestry estimates were higher in NMO-RP than in MS-RP (20.5% vs. 12.5% patients. Moreover, principal component analyses showed that groups of NMO patients from different Brazilian regions were clustered close to the European ancestral population. CONCLUSIONS: Our findings demonstrate that European genetic contribution predominates in NMO and MS patients from Brazil.

  1. Brain parenchymal damage in neuromyelitis optica spectrum disorder - A multimodal MRI study

    International Nuclear Information System (INIS)

    Pache, F.; Paul, F.; Zimmermann, H.; Lacheta, A.; Papazoglou, S.; Kuchling, J.; Wuerfel, J.; Brandt, A.U.; Finke, C.; Hamm, B.; Ruprecht, K.; Scheel, M.

    2016-01-01

    To investigate different brain regions for grey (GM) and white matter (WM) damage in a well-defined cohort of neuromyelitis optica spectrum disorder (NMOSD) patients and compare advanced MRI techniques (VBM, Subcortical and cortical analyses (Freesurfer), and DTI) for their ability to detect damage in NMOSD. We analyzed 21 NMOSD patients and 21 age and gender matched control subjects. VBM (GW/WM) and DTI whole brain (TBSS) analyses were performed at different statistical thresholds to reflect different statistical approaches in previous studies. In an automated atlas-based approach, Freesurfer and DTI results were compared between NMOSD and controls. DTI TBSS and DTI atlas based analysis demonstrated microstructural impairment only within the optic radiation or in regions associated with the optic radiation (posterior thalamic radiation p < 0.001, 6.9 % reduction of fractional anisotropy). VBM demonstrated widespread brain GM and WM reduction, but only at exploratory statistical thresholds, with no differences remaining after correction for multiple comparisons. Freesurfer analysis demonstrated no group differences. NMOSD specific parenchymal brain damage is predominantly located in the optic radiation, likely due to a secondary degeneration caused by ON. In comparison, DTI appears to be the most reliable and sensitive technique for brain damage detection in NMOSD. (orig.)

  2. Deformación plástica de compuestos mullita/óxido de itrio

    Directory of Open Access Journals (Sweden)

    Ramírez de Arellano López, A.

    2001-06-01

    Full Text Available Mullite (3Al2O3.2SiO2 based composites have excellent mechanical and thermal properties. The same characteristics that give mullite good resistance to plastic deformation also make its sintering difficult. Yttria is one of the most commonly used additives to reduce sintering temperatures in mullite. Additionally vitreous silicates (Y2Si2O7 could improve ductility. In this work we have used mullite samples with various amounts of Y2O3 (0, 5 and 9 wt.%. Details of processing and characterization of these composites have been the subject of a previous publication. We have compared the ductility of these composites by means of compressive deformation tests at elevated temperatures. Creep tests were performed at temperatures between 1300 and 1400ºC, in air, in a stress range of 0.69 to 34.5 MPa.

    Los compuestos a partir de mullita (3Al2O3.2SiO2 presentan unas magníficas propiedades mecánicas y térmicas. Las mismas características que hacen de la mullita resistente a la deformación plástica, dificultan su densificación. El óxido de itrio es uno de los aditivos más utilizados para reducir la temperatura de sinterización de la mullita. Adicionalmente la presencia de silicatos vítreos (en este caso Y2Si2O7 incrementan la ductilidad. En esta investigación se han usado muestras de mullita con diversas cantidades de Y2O3 (0%, 5% y 9% en peso. Los detalles sobre el procesado y caracterización de los compuestos han sido objeto de una publicación previa. Se ha estudiado comparativamente la ductilidad de estos materiales mediante experimentos de deformación en compresión a alta temperatura. Los ensayos se han desarrollado entre 1300 y 1400ºC, en atmósfera de aire, cubriendo un rango de tensiones de compresión entre 0.69 y 34.4 MPa.

  3. Aluminio pulvimetalúrgico: desarrollo y mejora de sus aleaciones y materiales compuestos

    Directory of Open Access Journals (Sweden)

    Ruiz-Navas, E. M.

    2008-06-01

    Full Text Available Powder metallurgy components demand is increasing in the last few years mainly due to the necessity of products assigned to automotive and aerospace industries, which has allow an important development of aluminium alloys and composites (AMCs. Consolidation of aluminium alloys by sintering present a main problem: the oxide layer that cover aluminium particles. Several alternatives are studied in this work as solution to the oxide layer problem during the sintering of series 2xxx aluminium alloys. One of these solutions is related to the addition of tin traces, and the other is the addition of a second alloy. Moreover, aluminium metal matrix composites are characterized by excellent properties as combination of properties which comes from the matrix and from the reinforcement. The last part of this study is focused to the analysis of one aluminium matrix composite as the influence of several quantities of reinforcement.

    El auge en la demanda de componentes pulvimetalúrgicos destinados principalmente al sector automovilístico y aeroespacial ha permitido un fuerte desarrollo tanto de aleaciones como de MMCs base aluminio (AMCs. El principal problema a la hora de consolidar estos materiales vía pulvimetalúrgica es la capa de óxido que recubre a las partículas de aluminio. En este trabajo se presentan varias alternativas como solución a este problema, aplicadas a la consolidación de aleaciones de aluminio pertenecientes a la serie 2xxx, entre ellas, la adición de trazas de estaño y la adición de una aleación Al-Si. En cuanto a los materiales compuestos de matriz de aluminio, se caracterizan por presentar propiedades únicas como combinación de las propiedades individuales que caracterizan tanto a la matriz como al refuerzo. En la última parte de este trabajo se estudia la consolidación de un material compuesto así como la influencia de las distintas cantidades de refuerzo.

  4. SÍNTESIS IN SITU DE NANOPARTÍCULAS DE PLATA SOBRE FIBRAS DE FIQUE

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    Sergio Ovalle

    2014-07-01

    Full Text Available Se realizó la síntesis de un material nanocompuesto mediante la deposiciónin situ de nanopartículas (NPs de plata sobre fibras de Fique. La influencia de parámetros experimentales, como concentración del precursor, concentración del agente reductor y tiempos de inmersión de las fibras en la solución del precursor y del agente reductor, se evaluó en términos de recubrimiento, tamaño y dispersión del nanomaterial sobre la superficie. Los nanocompositos fueron caracterizados mediante espectroscopia de reflectancia difusa UV-Vis (RD, microscopía electrónica (FESEM y difracción de rayos X (DRX. El control de los parámetros experimentales mencionados permitió obtener un material que exhibe recubrimiento uniforme y completo de NPs sobre la superficie y tamaños promedio de NPs de 40 nm. 

  5. Método experimental para consolidar fibras de papel. (I parte del estudio

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    Alicia De Lera Santín

    2009-08-01

    Full Text Available En este artículo describimos un nuevo método enzimático para consolidar la celulosa del papel. Este método consiste en la síntesis de la celulosa con una enzima hidrolítica: la celulasa. Ésta actúa como una sintetasa, consolidando el papel cuando es mezclada en una solución orgánica de solvente/tampón (4:1 en presencia de un sustrato (β-cellobiosyl fluoride. Para mejorar el tratamiento añadimos un gel de agar-agar con todos los reactivos necesarios. Para observar el estado de las fibras antes y después del tratamiento, realizamos test mecánicos y fotografías de microscopía electrónica de barrido. Se observó que el proceso de consolidación casi consigue recuperar el estado físico inicial de las fibras así como su resistencia al desgarre y alargamiento.

  6. Quantitative MRI analysis of the brain after twenty-two years of neuromyelitis optica indicates focal tissue damage

    DEFF Research Database (Denmark)

    Aradi, Mihaly; Koszegi, Edit; Orsi, Gergely

    2013-01-01

    ). In such abnormal NAWM regions, biexponential diffusion analysis and quantitative spectroscopy indicated extracellular edema and axonal loss, respectively. Repeated analysis 6 months later identified the same alterations. Such patchy alterations were not detectable in the NAWM of the 3 cases with short-term NMO......BACKGROUND: The long-term effect of neuromyelitis optica (NMO) on the brain is not well established. METHODS: After 22 years of NMO, a patient's brain was examined by quantitative T1- and T2-weighted mono- and biexponential diffusion and proton spectroscopy. It was compared to 3 cases with short...

  7. Efecto de la ingesta de compuestos avanzados de la reacción de Maillard sobre el metabolismo gastrointestinal

    OpenAIRE

    Pastoriza de la Cueva, Silvia

    2013-01-01

    La realización de la presente tesis doctoral se ha llevado a cabo gracias a un contrato de Técnico Superior de Laboratorio adscrito al Proyecto de Excelencia concedido por la Junta de Andalucía (AGR-4135) denominado "Repercusiones de la ingesta de compuestos avanzados de la reacción de Maillard sobre el metabolismo gastrointestinal y óseo".

  8. FIBRAS ANIMALES ARQUEOLÓGICAS. ESTUDIO DE LA ESTRUCTURA FÍSICA CELULAR DE LAS FIBRAS/Archaeological animal fibres. Study of their physical cellular structure

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    María del Carmen Reigadas

    2012-11-01

    Full Text Available El análisis microscópico de la morfología de fibras animales se ha empleado conjuntamente con otras líneas de evidencia, brindando información taxonómica útil para reconstruir posibles escenarios que den cuenta de las estrategias implementadas por las sociedades cazadoras- recolectoras y/ o productoras, en vistas a la explotación y aprovechamiento de los recursos animales. En esta oportunidad y en el marco de la vía mencionada, se presenta como complemento de los resultados obtenidos a partir de las variables cualitativas y cuantitativas tales como grosor, médula, tipo de fibra y color, el avance realizado en el estudio de la corteza, estructura no contemplada hasta el presente. Se evalúa a partir de la información generada su relevancia en la búsqueda de indicadores interespecíficos. El análisis fue realizado en muestras correspondientes al nivel 4 del sitio Cueva Salamanca 1 (7500 + 60 AP [Beta 178223] (Pintar 2004 y nivel 4 de Quebrada Seca 3 (Cal. 3684- 4226 1s (Aschero et al. 1993-94, ambos localizados en la puna meridional (Antofagasta de la Sierra, Argentina de las cuales ya se disponen designaciones taxonómicas obtenidas por análisis morfológico. Abstract Microscopic analysis of the morphology of animal fibers has been used in conjunction with other lines of evidence, providing useful taxonomic information to reconstruct scenarios that account for the strategies implemented by hunter-gatherers and producers, in view of the use of animal resources. Here, the advance made in the study of cortical cells is offered as a complement to results obtained from qualitative and quantitative variables such as thickness, medulla, fiber type and color. The information gained is used to evaluate the relevance in the search of interspecific indicators. The analysis was performed on samples corresponding to level 4 from Cueva Salamanca 1 (7500 ± 60 BP [Beta 178223] (Pintar 2004 and level 4 from Quebrada Seca 3 (Cal. 3684 to 4226 1s

  9. CONDUCTIVIDAD Y PERCOLACION DE UN MATERIAL COMPUESTO: OXIDO MAGNETICO-POLIANILINA

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    Juan C. Aphesteguy

    2013-01-01

    Full Text Available El objetivo de este trabajo es estudiar la conductividad de un material compuesto (óxido de hierro /polianilina a fin de determinar la relación mínima entre sus componentes que mantiene la interconexión entre las partículas de polianilina. Para ello se prepararon por mezcla sólida, sistemas formados por polianilina (en su forma básica, no conductora, emeraldina dopada con ácido canforsulfónico (CSA y un óxido de hierro magnético (Fe xOy (parcialmente encapsulado en polianilina. Los polvos fueron compactados a 1,3.103 MPa. Se estudió la conductividad del sistema en función de la fracción en volumen (P del óxido incluido. Se determinó, para las condiciones experimentales establecidas, una fracción de percolación Pc = 0,131 (38,6 % m/m FexOy a 300K. Los resultados experimentales indicaron que la conductividad presenta un comportamiento crítico no universal que se interpretó empleando el modelo de Kusy.

  10. REMOCIÓN DEL COLORANTE COMPUESTO NARANJA REMAZOL DE AGUAS RESIDUALES GENERADAS EN LA INDUSTRIA TEXTIL

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    Luis A. Bernal

    2017-01-01

    Full Text Available El objetivo de este trabajo, fue determinar la capacidad de remoción del colorante compuesto naranja remazol presente en aguas residuales textiles, utilizando el proceso de adsorción con carbón activado, con base en el pH y la concentración de colorante. La metodología involucró la preparación de muestras con concentraciones de 100 a 600 ppm de colorante a pH de 3, 7 y 9; la obtención de isotermas ajustadas a los modelos de Langmuir y Freundlich; y la determinación de la concentración del colorante a través de un espectrofotómetro UV-Vis. Los resultados indicaron una mejor eficiencia de remoción del colorante a pH 3, concluyendo que a mayor pH disminuye la capacidad de adsorción, debido principalmente a las interacciones electrostáticas que se generan entre la superficie del adsorbente y el colorante.

  11. INTERACCIONES NUTRIMENTALES Y NORMAS DE DIAGNÓSTICO DE NUTRIMENTO COMPUESTO EN NOGAL PECANERO (Carya illinoensis

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    J. L. García-Hernández

    2009-01-01

    Full Text Available El cultivo de nogal pecanero (Carya illinoensis es actualmente uno de los de mayor rentabilidad en el norte de México. En la región conocida como la Comarca Lagunera que comprende parte de los estados de Coahuila y Durango se han reportado diversos desbalances nutrimentales que afectan el rendimiento y productividad de este cultivo. Este estudio fue desarrollado para determinar las normas de diagnóstico de nutrimento compuesto (DNC y para estudiar las interacciones entre nutrimentos de dicho cultivo. A través de la metodología de DNC se determinó el valor mínimo de alto rendimiento de fruto maduro, así como los rangos de macronutrimentos (N, P, K, Ca y Mg óptimos correspondientes en el tejido foliar, los cuales son llamados normas nutrimentales. Estas normas se definieron considerando un valor de rendimiento mínimo de 1.39 t·ha-1 en este cultivo. Los análisis de componentes principales, utilizando los índices de DNC, permitieron identificar las siguientes interacciones: positiva N-R y negativas N-Ca, K-Mg y P-Ca.

  12. Análisis comparativo de compuestos fenólicos totales y actividad antioxidante de cuatro marcas de tisanas de Hibiscus sabdariffa (Malvaceae comercializadas en Costa Rica

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    Melissa Agüero

    2014-01-01

    Full Text Available Las tisanas de rosa de Jamaica (Hibiscus sabdariffa son consumidas en Costa Rica por su conocido efecto cardioprotector asociado a la presencia de compuestos fenólicos, principalmente antocianinas. Este trabajo estableció diferencias en el perfil de compuestos fenólicos y su actividad anti-radical entre diferentes comercializadores de tisanas de Hibiscus sabdariffa en Costa Rica. Se identificaron cualitativamente taninos, flavonoides y antocianinas. Se cuantificó la cantidad total de compuestos fenólicos por el método de Folin-Ciocalteu y se cuantificó la actividad antioxidante con el método de DPPH. Todas las marcas comerciales demostraron presencia de compuestos fenólicos, incluyendo antocianinas; sin embargo, se encontraron diferencias significativas en el contenido de compuestos fenólicos y actividad anti-radical, entre los diferentes productores de tisanas. Por ello, se concluye que en el mercado costarricense, el perfil en compuestos fenólicos de las tisanas en estudio varía de acuerdo con el productor.

  13. CONSUMO DE FIBRA DIETÉTICA EN LACTANTES MENORES DE 2 AÑOS Y ESTREÑIMIENTO FUNCIONAL

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    Carlos Alberto Velasco Benítez

    2014-09-01

    Full Text Available Introducción: La inclusión de la fibra dietética (FD, tiene múltiples beneficios sobre la salud del ser humano; sin embargo, en pediatría, existen grandes brechas concernientes a la relación de fibra y estreñimiento. Objetivo: Describir el hábito intestinal en lactantes . Se tuvo en cuenta la alimentación con leche materna, el tiempo de inicio de alimentación complementaria y el antecedente de madre o cuidador con EF. Los resultados son expresados como X±DS. El análisis estadístico incluyó X2 y prueba de Spearman  o Fischer. Resultados: Se estudiaron 125 lactantes de 13±7 meses, 86 masculinos. No hubo diferencias significativas en edad, sexo, consumo de gramos de fibra/d, ni con la alimentación con leche materna, el tiempo de inicio de la alimentación complementaria y el antecedente de madre o cuidador con EF. Conclusión: No encontramos ninguna asociación entre hábito intestinal y gramos de fibra consumidos, ni alimentación con leche materna, inicio de la alimentación complementaria precoz y antecedente de EF en la madre o cuidador.

  14. Comportamiento frente al desgaste en materiales compuestos de aluminio reforzados con partículas cerámicas

    Directory of Open Access Journals (Sweden)

    Busquets-Mataix, D.

    2004-04-01

    Full Text Available The present work deals with the wear behaviour on AA6061 based aluminium matrix composites reinforced with different kinds of ceramic particles: TiB2, B4C, Si3N4, Al2O3 y SiC. Composites were obtained by means of a solid-state consolidation method, combining both powder metallurgy processing and hot extrusion. The study carried out was based on a pin-on-ring apparatus under dry sliding conditions (dry friction. Both friction coefficient and wear rate were measured for each composite. Scanning Electron Microscope (SEM was used to analyse wear and the tribolayer formed. Results show that wear rate is lower in composites than in the unreinforced alloy in every case, as expected. Differences among composites are probably related to different particle size rather than nature of reinforcements. On the other hand, friction coefficient do not show a trend on composites, being lower than the base alloy in some cases and higher in others.

    El presente artículo trata sobre las propiedades tribológicas en materiales compuestos de matriz de aleación de aluminio AA6061, reforzados con partículas cerámicas de diferente naturaleza: TiB2, B4C, Si3N4, SiC y Al2O3. Los materiales compuestos fueron obtenidos mediante un procedimiento de consolidación en estado sólido que combina la pulvimetalurgia con un proceso de extrusión en caliente. El estudio tribológico realizado se basó en una metodología de ensayo del tipo pin-on-ring con deslizamiento en seco (sin lubricación. Se analizaron para cada caso el coeficiente de rozamiento y la tasa de desgaste en función de la distancia de deslizamiento. Asimismo, las muestras ensayadas se observaron mediante microscopía electrónica de barrido. Los resultados obtenidos demuestran que las tasas de desgaste de los compuestos son inferiores en todos los casos a los de la matriz sin reforzar. Entre los compuestos, las diferencias encontradas son debidas al tamaño medio de las partículas de refuerzo, obteni

  15. Gaze palsy, hypogeusia and a probable association with miscarriage of pregnancy--the expanding clinical spectrum of non-opticospinal neuromyelitis optica spectrum disorders: a case report.

    Science.gov (United States)

    Chang, Thashi; Withana, Milinda

    2015-02-10

    Neuromyelitis optica is characterised by optic neuritis, longitudinally-extensive transverse myelitis and presence of anti-aquaporin-4 antibodies in the serum. However, non-opticospinal central nervous system manifestations have been increasingly recognised. Awareness of the widening clinical spectrum of neuromyelitis optica (unified within the nosology of 'neuromyelitis optica spectrum disorders') is key to earlier diagnosis and appropriate therapy. We report 2 patients to illustrate the varied clinical manifestations of neuromyelitis optica spectrum disorders while postulating an effect of anti-aquaporin-4 antibodies on the miscarriage of pregnancy. This is the first report of horizontal gaze palsy as a presenting symptom of neuromyelitis optica spectrum disorders. Patient 1: A 17-year-old Sri Lankan female presented with hypersomnolence, lateral gaze palsy and loss of taste of 1 week duration. Two years previously she had presented with intractable hiccups and vomiting followed by a brainstem syndrome. Magnetic resonance imaging showed a lesion in the left cerebellum extending into the pons while lesions in bilateral hypothalami and medulla noted 2 years ago had resolved. Autoimmune, vasculitis and infection screens were negative. Anti-aquaporin-4 antibodies were detected in serum. All her symptoms resolved with immunosuppressive therapy. Patient 2: A 47-Year-old Sri Lankan female presented with persistent vomiting lasting over 3 weeks. Three years previously, at 25-weeks of her 4(th) pregnancy, she had presented with quadriparesis and was found to have a longitudinally extensive transverse myelitis from C2 to T2 vertebral levels, which gradually improved following intravenous steroid therapy. Magnetic resonance imaging showed a hyper-intense lesion in the area postrema and longitudinally extensive atrophy of the cord corresponding to her previous myelitis. Autoimmune, vasculitis and infection screens were negative. Anti-aquaporin-4 antibodies were detected in

  16. Comportamiento al corte de hormigones reforzado con fibras de acero Shear behavior of steel fiber reinforced concretes

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    Sergio Carmona Malatesta

    2009-01-01

    Full Text Available En este artículo se presentan los resultados de un estudio experimental a cerca de la influencia de la incorporación de fibras de acero en el comportamiento del hormigón frente a esfuerzos de corte, medidos utilizando el ensayo JSCE - SF6, modificado. Usando los resultados de los ensayos realizados se evalúa La capacidad de disipación de energía del hormigón durante la rotura o tenacidad del hormigón reforzado con fibras en función del contenido y tipo de Fibra utilizada. Con los resultados obtenidos, se puede concluir que la incorporación de fibras como refuerzo al esfuerzo de corte aumenta la ductilidad del hormigón, permitiendo mayores deformaciones que un hormigón convencional. Se observa que la capacidad de absorber energía de los hormigones, cuantificada a través de la tenacidad absoluta, se incrementa más de tres veces cuando se incorporar fibras y no se tienen roturas frágiles. Por lo tanto, la incorporación de fibras como refuerzo es una buena solución para mejorar la respuesta del hormigón ante solicitaciones de corte. Por otra parte, se demuestra que el ensayo de corte propuesto por la recomendación japonesa JSCE-SF6, levemente modificada, entrega resultados coherentes y reproducibles, permitiendo cuantificar diferentes propiedades del hormigón reforzado con fibras sometido a solicitaciones de corte.This paper presents the results of an experimental research on influence of steel fibers on shear behavior of concrete, using modified JSCE - SF6 test. The tests results are used to evaluate the energy dissipation capacity of concrete during failure or fiber reinforced concrete toughness, in terms of amount and type of fibers. With the results, it can be concluded that the addition of fibers as shear reinforcement influence significantly the ductility of concrete. The results show that the absorption energy capacity of concrete, measured by mean of absolute toughness, increase 3 times when concrete is reinforced with

  17. Clinical and imaging characteristics and autoantibody analysis of neuromyelitis optica spectrum disorders

    Directory of Open Access Journals (Sweden)

    Nan LIU

    2014-09-01

    Full Text Available Objective To observe the clinical and imaging characteristics and the changes of autoimmune antibodies in the serum and cerebrospinal fluid (CSF of patients with neuromyelitis optica spectrum disorders (NMOSDs.  Methods The data of 10 patients with NMOSDs in Aviation General Hospital of China Medical University from January 2011 to June 2014 were collected. The clinical and imaging features were retrospectively reviewed, and NMO-IgG in serum and CSF, anti-nuclear antibody (ANA, homocysteine (Hcy and thyroid function were analyzed.  Results Cranial and spinal MRI of these patients showed that brain stem was involved in 3 cases, cervical cord in 3 cases, thoracic cord in 6 cases, and cervical-thoracic cord in one case. Serum NMO-IgG were tested in 8 cases, among whom 3 patients were positive (3/8 and 5 were negative (5/8. ANA was positive in one case (1/3, and thyroglobulin (TG antibody and thyroid peroxidase (TPO antibody were positive in 2 cases (2/3. Hypothyroidism occured in 2 cases, hyperthyroidism occured in one case, and Hcy rised in 2 cases.  Conclusions NMOSDs frequently occur in young and middle-aged women. Patients who were highly suspected with NMOSDs should receive tests of autoimmune antibodies in the serum and CSF, and cranial and spinal MRI examination, in order to make a definite diagnosis and receive appropriate treatment. Retesting the autoimmune antibodies should be done in catabasis, in order to identify the relationship between autoimmune antibodies and NMOSDs. doi: 10.3969/j.issn.1672-6731.2014.09.010

  18. Long-term MRI findings in neuromyelitis optica: seropositive versus seronegative patients.

    Science.gov (United States)

    Kıyat-Atamer, A; Ekizoğlu, E; Tüzün, E; Kürtüncü, M; Shugaiv, E; Akman-Demir, G; Eraksoy, M

    2013-05-01

    Neuromyelitis optica (NMO) is a severe demyelinating inflammatory disorder associated with serum antibodies against aquaporin 4 (AQP4-Ab). A significant number of patients with NMO remain seronegative over time. Long-term observational magnetic resonance imaging (MRI) studies of the CNS in patients with NMO are rare or of limited duration. The objective of this study is to determine long-term MRI characteristics of seropositive and seronegative patients, and assess possible overlap with multiple sclerosis (MS). Clinical and radiological characteristics of 28 patients with NMO at onset and of 17 patients after an average follow-up time of 9 years were recorded. Fifty percent of patients were seropositive for AQP4-Ab. Onset and final brain/spinal MRI scans were retrospectively analysed and compared. Significantly more patients in the seronegative group had brain lesions at onset. Spinal lesions of seropositive patients were longer and showed increased cord swelling at onset MRI scans. After the follow-up time the differences between both groups disappeared. Patients in the seropositive group tended to develop brain lesions over time. No patient fulfilled Barkhof's or McDonald's radiological criteria for MS at onset or over time. Brain MRI features show differences between seropositive and seronegative patients at time of onset in NMO, but differences between groups vanish over time. None of the AQP4-negative patients fulfill radiological MS criteria on a long-term basis, suggesting that seronegative NMO constitutes an independent entity. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

  19. Quantitative Susceptibility Mapping Indicates a Disturbed Brain Iron Homeostasis in Neuromyelitis Optica - A Pilot Study.

    Directory of Open Access Journals (Sweden)

    Thomas Martin Doring

    Full Text Available Dysregulation of brain iron homeostasis is a hallmark of many neurodegenerative diseases and can be associated with oxidative stress. The objective of this study was to investigate brain iron in patients with Neuromyelitis Optica (NMO using quantitative susceptibility mapping (QSM, a quantitative iron-sensitive MRI technique. 12 clinically confirmed NMO patients (6 female and 6 male; age 35.4y±14.2y and 12 age- and sex-matched healthy controls (7 female and 5 male; age 33.9±11.3y underwent MRI of the brain at 3 Tesla. Quantitative maps of the effective transverse relaxation rate (R2* and magnetic susceptibility were calculated and a blinded ROI-based group comparison analysis was performed. Normality of the data and differences between patients and controls were tested by Kolmogorov-Smirnov and t-test, respectively. Correlation with age was studied using Spearman's rank correlation and an ANCOVA-like analysis. Magnetic susceptibility values were decreased in the red nucleus (p0.95; between -15 and -22 ppb depending on reference region with a trend toward increasing differences with age. R2* revealed significantly decreased relaxation in the optic radiations of five of the 12 patients (p<0.0001; -3.136±0.567 s-1. Decreased relaxation in the optic radiation is indicative for demyelination, which is in line with previous findings. Decreased magnetic susceptibility in the red nucleus is indicative for a lower brain iron concentration, a chemical redistribution of iron into less magnetic forms, or both. Further investigations are necessary to elucidate the pathological cause or consequence of this finding.

  20. The Pathology of an Autoimmune Astrocytopathy: Lessons Learned from Neuromyelitis Optica

    Science.gov (United States)

    Lucchinetti, Claudia F.; Guo, Yong; Popescu, Bogdan F. Gh.; Fujihara, Kazuo; Itoyama, Yasuto; Misu, Tatsuro

    2014-01-01

    Neuromyelitis optica (NMO) is a disabling autoimmune astrocytopathy characterized by typically severe and recurrent attacks of optic neuritis and longitudinally-extensive myelitis. Until recently, NMO was considered an acute aggressive variant of multiple sclerosis (MS), despite the fact that early studies postulated that NMO and MS may be two distinct diseases with a common clinical picture. With the discovery of a highly specific serum autoantibody (NMO-IgG), Lennon and colleagues provided the first unequivocal evidence distinguishing NMO from MS and other CNS inflammatory demyelinating disorders. The target antigen of NMO-IgG was confirmed to be aquaporin-4 (AQP4), the most abundant water channel protein in the central nervous system (CNS), mainly expressed on astrocytic foot processes at the blood brain barrier, subpial and subependymal regions. Pathological studies demonstrated that astrocytes were selectively targeted in NMO as evidenced by the extensive loss of immunoreactivities for the astrocytic proteins, AQP4 and glial fibrillary acidic protein (GFAP), as well as perivascular deposition of immunoglobulins and activation of complement even within lesions with a relative preservation of myelin. In support of these pathological findings, GFAP levels in the cerebrospinal fluid (CSF) during acute NMO exacerbations were found to be remarkably elevated in contrast to MS where CSF-GFAP levels did not substantially differ from controls. Additionally, recent experimental studies showed that AQP4 antibody is pathogenic, resulting in selective astrocyte destruction and dysfunction in vitro, ex vivo, and in vivo. These findings strongly suggest that NMO is an autoimmune astrocytopathy where damage to astrocytes exceeds both myelin and neuronal damage. This chapter will review recent neuropathological studies that have provided novel insights into the pathogenic mechanisms, cellular targets, as well as the spectrum of tissue damage in NMO. PMID:24345222

  1. Painful tonic spasm in neuromyelitis optica spectrum disorders: Prevalence, clinical implications and treatment options.

    Science.gov (United States)

    Liu, Ju; Zhang, Qin; Lian, Zhiyun; Chen, Hongxi; Shi, Ziyan; Feng, Huiru; Miao, Xiaohui; Du, Qin; Zhou, Hongyu

    2017-10-01

    Painful tonic spasm (PTS) is a common symptom in patients with neuromyelitis optica spectrum disorders (NMOSD). This study aimed to obtain further insights into the prevalence, characteristics, and treatment of PTS in patients with NMOSD, and to systematically investigate and compare the clinical features and prognosis of NMOSD with and without PTS. We reviewed the medical records and prospectively interviewed patients with NMOSD who attended the West China Hospital of Sichuan University in Chengdu, China between September 2014 and December 2016. In total, 52 of the 230 patients with NMOSD experienced PTS (22.61%). Patients with NMOSD and PTS were characterized by a higher age at onset (P = 0.017), higher annual relapse rate (ARR) (P = 0.003), higher ARR of myelitis (P = 0.011), and a tendency to experience pruritus (P = 0.025). Sodium channel blocking antiepileptic drugs (carbamazepine or oxcarbazepine) had higher efficacy than gabapentin in the treatment of PTS (P = 0.001). Although the progression index was higher in patients with PTS, this difference did not reach statistical significance (P = 0.05). Our study suggested that immunosuppressors for the prevention of relapse should be administered without delay in patients with NMOSD and PTS. Owing to the side effects of carbamazepine, we recommend oxcarbazepine as the first-line of treatment for PTS in patients with NMOSD. Whether PTS is a marker of disease severity in NMOSD remains to be determined, requiring a long-term prospective observational study. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Aquaporin-4 antibody in neuromyelitis optica: re-testing study in a large population from China.

    Science.gov (United States)

    Long, Youming; Liang, Junyan; Zhong, Rong; Wu, Linzhan; Qiu, Wei; Lin, Shaopeng; Gao, Cong; Chen, Xiaohui; Zheng, Xueping; Yang, Ning; Gao, Min; Wang, Zhanhang

    2017-09-01

    Aquaporin-4 (AQP4) antibody sero-positivity is critically important in neuromyelitis optica (NMO). However, the sensitivity of different assays is highly variable. Repeating detection with a highly sensitive assay in a large population is necessary in the case of so-called negative NMO. Retrospective analysis where AQP4 antibodies were detected by commercial cell-based assay (CBA), in-house M23-CBA and in-house M1-CBA. Of the 1011 serum samples, 206 (20.4%) were sero-positive by primary commercial CBA. In the retest, all 206 participants positive by primary commercial CBA also yielded positive results by in-house M23-CBA and the second commercial CBA again, but only 124 positive in in-house M1-CBA. Among the 805 participants negative by primary commercial CBA, 71 participants were positive for in-house M23-CBA, of which 20 participants were positive for the second commercial CBA, and none were positive by in-house M1-CBA. Of the 171 cerebral spinal fluid samples, 75 (43.9%) were positive by primary commercial CBA. All 75 participants positive by primary commercial CBA also yielded positive results by in-house M23-CBA and the second commercial CBA. Forty-nine (65.3%) of these 75 participants were positive by in-house M1-CBA. Among the 96 participants negative by primary commercial CBA, 15 participants were positive for in-house M23-CBA and none were positive by in-house M1-CBA and the second commercial CBA. Different AQP4 isoforms in CBA result in different detection effects, and in-house M23-CBA is the most sensitive method. Some AQP4 antibody-negative NMO may be subject to diagnostic uncertainty due to limitations of the assays.

  3. Disruption of the leptomeningeal blood barrier in neuromyelitis optica spectrum disorder

    Science.gov (United States)

    Flanagan, Eoin P.; Fujihara, Kazuo; Kim, Ho Jin; Skejoe, Hanne P.; Wuerfel, Jens; Kuroda, Hiroshi; Kim, Su Hyun; Maillart, Elisabeth; Marignier, Romain; Pittock, Sean J.; Paul, Friedemann; Weinshenker, Brian G.

    2017-01-01

    Objective: To describe leptomeningeal blood-barrier impairment reflected by MRI gadolinium-enhanced lesions in patients with aquaporin-4 immunoglobulin G (AQP4-IgG)–positive neuromyelitis optica spectrum disorder (NMOSD). Methods: A retrospective case series of 11 AQP4-IgG–positive NMOSD patients with leptomeningeal enhancement (LME) were collected from 5 centers. External neuroradiologists, blinded to the clinical details, evaluated MRIs. Results: LME was demonstrated on postcontrast T1-weighted and fluid-attenuated inversion recovery images as a sign of leptomeningeal blood-barrier disruption and transient leakage of contrast agent into the subarachnoid space in 11 patients, 6 in the brain and 6 in the spinal cord. The patterns of LME were linear or extensive and were accompanied by periependymal enhancement in 5 cases and intraparenchymal enhancement in all cases. The location of LME in the spinal cord was adjacent to intraparenchymal contrast enhancement with involvement of a median number of 12 (range 5–17) vertebral segments. At the time of LME on MRI, all patients had a clinical attack such as encephalopathy (36%) and/or myelopathy (70%) with median interval between symptom onset and LME of 12 days (range 2–30). LME occurred in association with an initial area postrema attack (44%), signs of systemic infection (33%), or AQP4-IgG in CSF (22%) followed by clinical progression. LME was found at initial clinical presentation in 5 cases and at clinical relapses leading to a diagnosis of NMOSD in 6 cases. Conclusion: This study suggests that altered leptomeningeal blood barrier may be accompanied by intraparenchymal blood-brain barrier breakdown in patients with AQP4-IgG–positive NMOSD during relapses. PMID:28451627

  4. Frequency of autoimmune disorders and autoantibodies in patients with neuromyelitis optica.

    Science.gov (United States)

    Pereira, Wildéa Lice de Carvalho Jennings; Reiche, Edna Maria Vissoci; Kallaur, Ana Paula; Oliveira, Sayonara Rangel; Simão, Andréa Name Colado; Lozovoy, Marcell Alysson Batisti; Schiavão, Lucas José Vaz; Rodrigues, Paula Raquel do Vale Pascoal; Alfieri, Daniela Frizon; Flauzino, Tamires; Kaimen-Maciel, Damacio Ramón

    2017-06-01

    The aim of this study was to report the frequency of autoimmune disorders and autoantibodies in 22 patients with neuromyelitis optica (NMO), as well as whether the seropositivity for autoantibodies differs between anti-aquaporin 4 (AQP4) positive and AQP4 negative NMO patients. Demographic, medical records, and a profile of autoantibodies were evaluated in 22 NMO patients, including AQP4, anti-thyroid-stimulating hormone receptor, antinuclear antibodies (ANA), anti-thyroperoxidase (anti-TPO), anti-thyroglobulin (anti-Tg), anti-double-stranded DNA, anti-neutrophil cytoplasmic, anti-cyclic citrullinate peptide, rheumatoid factor, anti-SSA/Ro, anti-SSB/La, anti-Smith antibodies (anti-Sm), anti-ribonucleoprotein, anti-nucleosome, and anti-Scl70. Thyroid-stimulating hormone and free thyroxin were measured. The frequency of women was higher than men (95.5% vs. 4.5%) and 68.2% were Afro-Brazilians. Six (27.3%) patients presented other autoimmune disorders, such as Hashimoto thyroiditis (n=2), Graves' disease (n=1), juvenile idiopathic arthritis (n=1), systemic lupus erythematosus and systemic sclerosis (n=1), and Raynaud's phenomenon (n=1). The most frequent autoantibodies were anti-AQP4 (54.5%), anti-nucleosome (31.8%), ANA (27.3%), anti-TPO (22.7%), and anti-Tg (22.7%). Difference was not observed in the frequency of autoimmune disorders when the patients were compared according to their anti-AQP4 status. The results of the present study underscored that the NMO patients present high frequency of autoantibodies against cellular antigens and the presence of autoimmune disorders. Further studies with large number of NMO patients may contribute to advances in the understanding of NMO disease mechanisms.

  5. Anti-thyroid antibodies and thyroid function in neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Wang, Xuan; Yi, Huan; Liu, Jia; Li, Min; Mao, Zhi-Feng; Xu, Li; Peng, Fu-Hua

    2016-07-15

    Neuromyelitis optica spectrum disorders (NMOSD) are complicated neuroautoimmune disorders which can coexist with other organ-specific autoimmune disorders. The most frequently specific organ is the thyroid. The aim of this study is to evaluate the thyroid function of NMOSD patients and detect the difference between anti-thyroid antibodies (ATAbs) seropositive and seronegative NMOSD patients. 88 patients diagnosed with NMOSD were enrolled and their thyroid functions were evaluated. They were divided into two groups by ATAbs abnormalities. In addition, demographic characteristics, clinical symptoms and MRI scan results of brain and spinal cord were assessed. Anti-thyroid peroxidase antibodies (TPOAbs) and anti-thyroglobulin antibodies (TGAbs) seropositivities were detected more frequently in patients with NMOSDs when compared with healthy controls (37.5% vs 14.9%, P=0.01, Diff22.6%, 95CI[9.0%, 34.9%]; 31.8% vs 16.2%, P=0.022, Diff15.6%, 95CI[2.27%, 27.9%]). In NMOSD patients, the Expanded disability status scale score (EDSS) score was significantly higher in ATAbs seropositive group than that in ATAbs seronegative group (median 6.5 vs 3.75, P=0.012). However, there is no significant difference for demographic characteristics and other clinical symptoms. Moreover, NMOSD patients with ATAbs abnormalities had more brain and cervical cord lesions when compared with ATAbs negative NMOSD patients (83.8% vs 61.4%, P=0.029, Diff22.4%, 95CI[0.9%, 40.9%]; 93.9% vs 59.6%, P=0.001, Diff34.3%, 95CI[13.6%, 50.4%]). NMOSD patients have a higher frequency of ATAbs abnormalities. ATAbs may be associated with disability status, brain abnormalities and cervical cord lesions. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Low T3 syndrome in neuromyelitis optica spectrum disorder: Associations with disease activity and disability.

    Science.gov (United States)

    Cho, Eun Bin; Min, Ju-Hong; Cho, Hye-Jin; Seok, Jin Myoung; Lee, Hye Lim; Shin, Hee Young; Lee, Kwang-Ho; Kim, Byoung Joon

    2016-11-15

    Neuromyelitis optica (NMO) sometimes coexists with serological marker-positive, non-organ-specific autoimmune disorders. We evaluated the prevalence of thyroid dysfunction and anti-thyroid antibodies in patients with NMO spectrum disorder (NMOSD) and investigated the associations between thyroid dysfunction/autoimmunity and clinical features of NMOSD. Forty-nine NMOSD patients with anti-aquaporin-4 antibody and 392 age- and sex-matched healthy controls were included. We measured the levels of thyroid hormones and anti-thyroid antibodies. The prevalence of clinical hypothyroidism, subclinical hyperthyroidism, and low T3 syndrome were higher in patients with NMOSD (4.1%, 12.2%, and 20.4%, respectively) compared with healthy controls (0.3%, 2.8%, and 0.5%, respectively; p=0.034, p=0.001, and p<0.001, respectively). However, anti-thyroperoxidase antibody (anti-TPO)-positivity did not significantly differ between NMOSD patients (20.4%) and controls (11.5%). Low T3 syndrome was more prevalent among patients during an attack (N=10/19, 52.6%) than those in remission (N=1/30, 3.3%). In addition, patients with low T 3 syndrome had significantly higher EDSS scores at the last visits as well as at sampling compared to those without low T3 syndrome. T3 levels were inversely correlated with EDSS score at the last visit after adjustment for age, sex, disease duration, clinical status (attack vs. remission), oral prednisolone use, iv methylprednisolone use, other immunosuppressive agents use, and the location of lesion (ρ=-0.416, p=0.010). Our study suggests that thyroid dysfunction is frequent in patients with NMOSD; particularly, serum T3 levels may be a useful indicator of disease activity and disability in NMOSD. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Fatigue in patients with neuromyelitis optica spectrum disorder and its impact on quality of life.

    Directory of Open Access Journals (Sweden)

    Jin Myoung Seok

    Full Text Available Fatigue is a prevalent symptom and major burden in neuroimmunological diseases. In neuromyelitis optica spectrum disorder (NMOSD, a severe autoimmune central nervous system (CNS inflammatory disease with autoantibodies reactive to aquaporin-4, there are few reports about fatigue and quality of life (QOL. We aimed to evaluate the severity of fatigue and its relationship with QOL in patients with NMOSD. We prospectively studied patients with NMOSD who were in remission and seropositive for anti-aquaporin-4 antibody, and they were divided into 2 groups based on the presence of fatigue assessed using the Functional Assessment of Chronic Illness Therapy-fatigue score. Sleep quality, depression, pain, and QOL were also evaluated. A total of 35 patients were enrolled (mean age, 46.5 ± 14.1 years; female: male = 29:6, and the median Expanded Disability Status Scale (EDSS score was 2.0 (range, 0 to 8.0. The patients with fatigue (N = 25, 71.4% had poorer sleep quality and more severe depression than those without fatigue (p = 0.009 and p = 0.001. Both the physical and mental QOL scores were lower in patients with fatigue than in those without fatigue (p = 0.033 and p = 0.004. Multiple linear regression analyses showed that the degree of fatigue with EDSS score and pain were independent predictors of physical aspects of QOL (B = 0.382, p = 0.001, whereas depression was the only predictor of the mental components of QOL (B = -0.845, p = <0.001. Fatigue is a common symptom and an important predictor of QOL in patients with NMOSD.

  8. Serological markers associated with neuromyelitis optica spectrum disorders in South India

    Directory of Open Access Journals (Sweden)

    Lekha Pandit

    2016-01-01

    Full Text Available Background: Neuromyelitis optica spectrum disorders (NMOSDs represent 20% of all demyelinating disorders in South India. No studies have determined the seroprevalence to both antibodies against aquaporin-4FNx01 and antimyelin oligodendrocyte glycoprotein antibody (anti-MOG+ in this population. Objective: To identify and characterize seropositive patients for anti-aquaporin-4 antibody (anti-AQP4+ and anti-MOG+ in South India. Materials and Methods: We included 125 consecutive patients (15 children who were serologically characterized using live transfected cells to human M23-AQP4 or full-length MOG. Results: Among a total of 125 patients, 30.4% of patients were anti-AQP4+, 20% were anti-MOG+, and 49.6% were seronegative. No patient was positive for both. Anti-MOG+ patients represented 28.7% (25/87 of seronegative NMOSD. In comparison to anti-AQP4+ patients, anti-MOG+ patients were commonly male, had less frequent attacks and milder disability on expanded disability status score scale. Seronegative patients were also predominantly male, 36% (9/25 had monophasic longitudinally extensive transverse myelitis and disability was comparable with anti-AQP4+ patients. Lumbar cord involvement was common in anti-MOG+ and seronegatives, whereas anti-AQP4+ patients had more cervical lesions. Conclusion: Anti-AQP4+/anti-MOG + patients accounted for nearly half of the patients suspected of having NMOSD in South India, indicating that antibody testing may be useful on the management of subgroups with different prognosis.

  9. Efficacy and safety of rituximab in neuromyelitis optica: Review of evidence

    Directory of Open Access Journals (Sweden)

    Masoud Etemadifar

    2017-01-01

    Full Text Available Neuromyelitis optica (NMO is an autoimmune inflammatory disease of the central nervous system with preferential involvement in the optic nerve and spinal cord with a widespread spectrum of clinical features; multiple therapeutic agents have been used with different results. Recent evidence points to B-cell-mediated humoral immunity in the pathogenesis of NMO. Rituximab targets the CD20 antigen on B-cells. Treatment leads to profound B-cell depletion, principally over an antibody-dependent cell cytotoxicity mechanism. The aim of our study was to review clinical trials to elucidate the impact of rituximab on the relapse rate, Expanded Disability Status Scale (EDSS, and progression of disability in NMO. We performed a comprehensive review of all studies that evaluated clinical and paraclinical effects of rituximab on NMO. MEDLINE-PubMed, Web of Sciences, EMBASE, and Cochrane databases up to June 2016 included in our searches. In addition, reference lists from articles identified by search as well as a key review article to identify additional articles included in the study. Rituximab targets the CD20 antigen on B-cells and decreases attack frequency and severity in patients with NMO; however, it does not remove attacks, even when modifying treatment to achieve B-cell depletion. Most of the investigations revealed that EDSS significantly in all patients with rituximab treatment will be decreased after treatment with rituximab. No new or enlarged lesions or pathological gadolinium enhancement was observed in serial brain and spinal cord magnetic resonance imaging, except for those observed concomitantly with clinical relapses and the median length of spinal cord lesions was significantly reduced after therapy. Rituximab targets the CD20 antigen and decreases attack frequency and severity in patients with NMO.

  10. Crescimento inicial de mudas de Acacia mangium cultivadas em mantas de fibra de coco contendo substrato de lodo de esgoto

    Directory of Open Access Journals (Sweden)

    Rômulo Fredson Duarte

    2011-02-01

    Full Text Available O objetivo deste trabalho foi avaliar o crescimento inicial de mudas de Acacia mangium semeadas em "manta" de fibra de coco contendo substrato de lodo de esgoto. O delineamento experimental foi em blocos casualizados com 13 tratamentos e três repetições, distribuídos em esquema fatorial (6 x 2 + 1 com seis proporções de fibra de coco e resíduo agregante, combinados com substratos com e sem lodo de esgoto, mais o tratamento-controle (terra de subsolo. Foram avaliados o índice de velocidade de emergência (IVE, a percentagem de emergência (EM e a altura das plantas aos 40 e 60 dias após a emergência. O tratamento- controle apresentou melhores resultados em relação ao IVE e EM quando comparado com os tratamentos utilizando "manta" de fibra de coco e resíduo agregante. Não houve diferença entre o controle e os tratamentos com "mantas" em altura das plantas aos 40 e 60 dias. Não foram observadas interações entre o tipo de substrato utilizado no semeio e as diferentes proporções de fibra de coco na "manta". A presença de lodo no substrato não influenciou o IVE e a EM, contudo verificou-se que o substrato sem lodo de esgoto proporcionou maior crescimento em altura das plantas. O uso de "mantas" contendo 50 e 100% de fibra de coco proporcionou maior crescimento às mudas de acácia em condições de campo.

  11. Association between TPMT*3C and decreased thiopurine S-methyltransferase activity in patients with neuromyelitis optica spectrum disorders in China.

    Science.gov (United States)

    Gong, Xiaoqing; Mei, Shenghui; Li, Xindi; Li, Xingang; Zhou, Heng; Liu, Yonghong; Zhou, Anna; Yang, Li; Zhao, Zhigang; Zhang, Xinghu

    2018-06-01

    Thiopurines are effective drugs in treating neuromyelitis optica spectrum disorders and other diseases. Thiopurines' toxicity is mainly imputed to thiopurine S-methyltransferase activity. In Chinese population, the most common and important variation of thiopurine S-methyltransferase is TPMT*3C (rs1142345). This study aims to reveal the association between thiopurine S-methyltransferase activity and genetic polymorphisms of thiopurine S-methyltransferase in patients with neuromyelitis optica spectrum disorders in China. A liquid chromatography tandem mass/mass method was used to evaluate the thiopurine S-methyltransferase activity by using 6-mercapthioprine as the substrate in human erythrocyte haemolysate via 1 h incubation at 37 °C to form its methylated product 6-methylmercaptopurine. The amount of 6-methylmercaptopurine was adjusted by haematocrit and normalized to 8 × 10 8 erythrocytes. The selected polymorphisms of thiopurine S-methyltransferase were identified using MassARRAY system (Sequenom) and multiple SNaPshot technique. In 69 patients with neuromyelitis optica spectrum disorders, thiopurine S-methyltransferase activity was 80.29-154.53 (127.51 ± 16.83) pmol/h/8 × 10 8 erythrocytes. TPMT*3C (rs1142345) was associated with lower thiopurine S-methyltransferase activity (BETA = -25.37, P = 0.011). Other selected variants were not associated with thiopurine S-methyltransferase activity. TPMT*3C affects TPMT activity in Chinese patients with neuromyelitis optica spectrum disorders. Further studies are warranted to confirm the results. TPRs = thiopurines; NMOSD = neuromyelitis optica spectrum disorders; TPMT = thiopurine S-methyltransferase; LC-MS/MS = liquid chromatography tandem mass/mass; 6-MMP = 6-methylmercaptopurine; IS = internal standard; SNP = single nucleotide polymorphism; MAF = minor allele frequency; HWE = Hardy-Weinberg equilibrium; BETA = regression coefficients; UTR-3 = untranslated region 3.

  12. Obtención de fibra dietética nutricional de valor agregado a partir de bagazo de caña

    OpenAIRE

    Licona Aguilar, Angeles Iveth

    2013-01-01

    La fibra dietética se reconoce cada vez más como un elemento importante para una nutrición sana; numerosas referencias respaldan esta aseveración en las que se ha demostrado no solo la importancia que la fibra tiene en la regulación de las funciones intestinales sino también para la prevención de algunas enfermedades. En este contexto, tiene sentido analizar la posibilidad de aprovechar la potencial utilización que brindan numerosos residuos agrícolas como fuente de fibra en una gran variedad...

  13. Carga limite para juntas mecânicas em laminados de fibra de carbono

    OpenAIRE

    Arthur Chaves de Mas Santacreu

    1989-01-01

    Neste trabalho são testadas várias juntas parafusadas com laminados de fibra de carbono. São investigadas as influências dos parâmetros geométricos e dos parâmetros de constituição do laminado no comportamento da curva carga versus deformação do furo carregado. Paralelamente é desenvolvido um modelo de elementos finitos linear elástico para calcular a deformação do furo carregado a partir das propriedades mecânicas do material e da geometria da junta. É proposto um critério de previsão de car...

  14. DESENVOLVIMENTO DE SORVETE ENRIQUECIDO COM FIBRAS DE LINHAÇA E LACTOBACILOS VIVOS E SUA VIABILIDADE

    Directory of Open Access Journals (Sweden)

    Marina Leopoldina Lamounier,

    2012-08-01

    Full Text Available Observa-se um aumento no número de consumidores conscientes que se preocupam em adquirir produtos de qualidade, que apresentam sabor e aparência agradáveis e são mais nutritivos e saudáveis. Dentre esses alimentos, se destacam os probióticos e as fibras que são comprovadamente benéficos à saúde. Este trabalho teve como objetivos desenvolver sorvete de ameixa enriquecido com fibras de linhaça e lactobacilos vivos, bem como verificar sua aceitação e viabilidade durante o período de validade. Foi utilizado Lactobacillus acidophilus como agente de fermentação do leite e sua viabilidade na mistura foi avaliada através das análises microbiológicas durante 0, 7, 14, 21 e 28 dias de estocagem. Os resultados obtidos mostraram que sorvete pode ser armazenado durante 28 dias a -18 ºC mantendo as suas características probióticas. Apesar de haver uma redução no número de células viáveis após o armazenamento, o sorvete apresentou no final desse período contagens médias de 1,9 x 107 UFC/g, estando de acordo com a legislação podendo, portanto ser considerado um alimento probiótico. A avaliação sensorial foi realizada por 50 provadores não treinados onde 91% aprovaram o produto e 76% declararam que comprariam o produto. Assim, demonstra-se a viabilidade de elaboração do sorvete adicionado de Lactobacillus acidophilus e linhaça.

  15. Estado de la cuestión sobre compuestos de yeso. la importancia actual de los residuos

    OpenAIRE

    San-Antonio González, A; Río Merino, Mercedes Del; Viñas Arrebola, Carmen

    2013-01-01

    El interés de los investigadores por mejorar las propiedades de los materiales tradicionales de construcción ha dado lugar a una gran cantidad de publicaciones durante las últimas décadas. El yeso es un material natural comúnmente utilizado en la construcción de edificios en forma de enlucidos y placas de yeso prefabricadas. En este estudio se estudian las líneas de investigación llevadas a cabo sobre los compuestos que tienen una matriz de yeso, mediante el análisis de los artículos científi...

  16. Revisión - Caracterización de compuestos de caucho con residuos de cuero posindustrial

    OpenAIRE

    Urrego Yepes, William; Cardona Vásquez, Natalia; Velásquez Restrepo, Sandra Milena; Abril Carrascal, Carolina

    2017-01-01

    RESUMEN Comúnmente los residuos industriales son dispuestos en vertederos o destinados para incineración, perdiendo con esto su uso potencial como materias primas en la fabricación de nuevos materiales. Las industrias del caucho y del cuero son consideradas como algunas de las más contaminantes a nivel mundial, sin embargo la industria del caucho ha demostrado su interés en el desarrollo de compuestos que involucren el uso de materiales clasificados como de desecho. Esta revisión abarca de ma...

  17. Materiales compuestos biodegradables con usos agronómicos a partir de raíces tuberosas

    OpenAIRE

    Versino, Florencia

    2017-01-01

    Los materiales poliméricos abarcan un amplio abanico de compuestos tanto naturales (proteínas, almidones, etc.) como sintéticos (polietilenos, poliuretanos, resinas epoxy, etc.) cuya versatilidad y fácil procesamiento los ha vuelto adecuados para un gran número de aplicaciones industriales. A raíz de la creciente necesidad de mitigar las emisiones de gases de efecto invernadero, reducir la acumulación de residuos sólidos y disminuir el consumo de recursos no renovables, el interés en el desar...

  18. Inmunonutrición: una potente herramienta para evaluar situaciones nutricionales y beneficios de nutrientes, compuestos bioactivos y alimentos

    OpenAIRE

    Díaz, L. E.; Gómez Martínez, Sonia; Nova, Esther; Romeo, J.; Marcos, Ascensión

    2012-01-01

    © 2012 Kellogg Company.El texto está disponible para cualquiera que se registre previamente en http://www.katedrakelloggs.com .- 8.Inmunonutrición: una potente herramienta para evaluar situaciones nutricionales y beneficios de nutrientes, compuestos bioactivos y alimentos119-130; 12 páginas,3 figuras, 3 tablas--Manual Práctico de Nutrición y Salud Kellogg’s, obra colectiva de visión multidisciplinar que surge a propuesta del colectivo médico ante la necesidad de recibir formación en materia d...

  19. Una interesante aproximación histórica al estudio del péndulo compuesto

    OpenAIRE

    Camargo, C.; Páez, R.

    2012-01-01

    Este artículo presenta una adaptación de la versión que hace E. Mach de la solución de Huy gens al problema de hallar el período de oscilación de un péndulo compuesto por varias partículas colocadas en linea, un problema de interés histórico y didáctico. Se propone también una solución intuitiva, que surge de consideraciones semejantes, al problema de hallar el periodo de oscilación de un aro.

  20. Study of optic nerve in patients with neuromyelitis optica using diffusion tensor imaging

    International Nuclear Information System (INIS)

    Chen Zhiye; Zhu Lijun; Lou Xin; Li Jinfeng; Yang Yang; Ma Lin

    2012-01-01

    Objective: To explore the diagnostic value of optic diffusion tensor imaging (DTI) in detecting the impairment of optic nerve in neuromyelitis optica (NMO) patients. Methods: Conventional MRI and optic DTI were performed in 28 NMO patients and 38 normal controls (NC). Fractional anisotropy (FA) values were measured in the anterior part, middle part and posterior part of intraorbital segment of optic nerve. The patients were classified into 3 groups based on the impairment of vision and visual evoked potential (VEP): monocular impairment (MI) group, 10 eyes; biocular impairment (BI) group, 36 eyes; and normal-appearing (NA) group, 10 eyes. All patients were performed with the evaluation of expanded disability status scale (EDSS). One-way analysis of variance (ANOVA), receiver operating characteristic (ROC) curve, and Spearman correlation analysis were performed among the subgroups of NMO and normal controls. Results: There was significantly statistical difference between the four groups (F=43.54, P<0.01). Decreased FA values were demonstrated in the MI group (0.29 ±0.08), BI group (0.27 ±0.08), and NA group (0.35 ±0.13) compared with NC (0.45 ±0.07) (P<0.01). FA value in BI group was significantly lower than that of NA group (P<0.01). Area under curve by ROC analysis in NC vs MI, NC vs BI, NC vs NA, and NC vs NMO was 0.92, 0.95, 0.74, and 0.91, respectively. The diagnostic sensitivity of ROC was 80%, 86%, 50%, and 79%, respectively. The diagnostic specificity of ROC was 95% for the each compared groups. FA value showed no correlation with EDSS for each NMO groups, and showed negative correlation with disease duration for BI group (r=-0.371, P<0.05). Conclusions: Various degrees of optic nerve injuries, indicated by decreased FA value,are present in NMO patients, and optic DTI may be a simple and effective tool for the quantitative evaluation of optic nerve in NMO patients. (authors)

  1. Comparative brain stem lesions on MRI of acute disseminated encephalomyelitis, neuromyelitis optica, and multiple sclerosis.

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    Zhengqi Lu

    Full Text Available BACKGROUND: Brain stem lesions are common in patients with acute disseminated encephalomyelitis (ADEM, neuromyelitis optica (NMO, and multiple sclerosis (MS. OBJECTIVES: To investigate comparative brain stem lesions on magnetic resonance imaging (MRI among adult patients with ADEM, NMO, and MS. METHODS: Sixty-five adult patients with ADEM (n = 17, NMO (n = 23, and MS (n = 25 who had brain stem lesions on MRI were enrolled. Morphological features of brain stem lesions among these diseases were assessed. RESULTS: Patients with ADEM had a higher frequency of midbrain lesions than did patients with NMO (94.1% vs. 17.4%, P<0.001 and MS (94.1% vs. 40.0%, P<0.001; patients with NMO had a lower frequency of pons lesions than did patients with MS (34.8% vs. 84.0%, P<0.001 and ADEM (34.8% vs. 70.6%, P = 0.025; and patients with NMO had a higher frequency of medulla oblongata lesions than did patients with ADEM (91.3% vs. 35.3%, P<0.001 and MS (91.3% vs. 36.0%, P<0.001. On the axial section of the brain stem, the majority (82.4% of patients with ADEM showed lesions on the ventral part; the brain stem lesions in patients with NMO were typically located in the dorsal part (91.3%; and lesions in patients with MS were found in both the ventral (44.0% and dorsal (56.0% parts. The lesions in patients with ADEM (100% and NMO (91.3% had poorly defined margins, while lesions of patients with MS (76.0% had well defined margins. Brain stem lesions in patients with ADEM were usually bilateral and symmetrical (82.4%, while lesions in patients with NMO (87.0% and MS (92.0% were asymmetrical or unilateral. CONCLUSIONS: Brain stem lesions showed various morphological features among adult patients with ADEM, NMO, and MS. The different lesion locations may be helpful in distinguishing these diseases.

  2. Neuromyelitis optica study model based on chronic infusion of autoantibodies in rat cerebrospinal fluid.

    Science.gov (United States)

    Marignier, R; Ruiz, A; Cavagna, S; Nicole, A; Watrin, C; Touret, M; Parrot, S; Malleret, G; Peyron, C; Benetollo, C; Auvergnon, N; Vukusic, S; Giraudon, P

    2016-05-18

    Devic's neuromyelitis optica (NMO) is an autoimmune astrocytopathy, associated with central nervous system inflammation, demyelination, and neuronal injury. Several studies confirmed that autoantibodies directed against aquaporin-4 (AQP4-IgG) are relevant in the pathogenesis of NMO, mainly through complement-dependent toxicity leading to astrocyte death. However, the effect of the autoantibody per se and the exact role of intrathecal AQP4-IgG are still controversial. To explore the intrinsic effect of intrathecal AQP4-IgG, independent from additional inflammatory effector mechanisms, and to evaluate its clinical impact, we developed a new animal model, based on a prolonged infusion of purified immunoglobulins from NMO patient (IgG(AQP4+), NMO-rat) and healthy individual as control (Control-rat) in the cerebrospinal fluid (CSF) of live rats. We showed that CSF infusion of purified immunoglobulins led to diffusion in the brain, spinal cord, and optic nerves, the targeted structures in NMO. This was associated with astrocyte alteration in NMO-rats characterized by loss of aquaporin-4 expression in the spinal cord and the optic nerves compared to the Control-rats (p = 0.001 and p = 0.02, respectively). In addition, glutamate uptake tested on vigil rats was dramatically reduced in NMO-rats (p = 0.001) suggesting that astrocytopathy occurred in response to AQP4-IgG diffusion. In parallel, myelin was altered, as shown by the decrease of myelin basic protein staining by up to 46 and 22 % in the gray and white matter of the NMO-rats spinal cord, respectively (p = 0.03). Loss of neurofilament positive axons in NMO-rats (p = 0.003) revealed alteration of axonal integrity. Then, we investigated the clinical consequences of such alterations on the motor behavior of the NMO-rats. In a rotarod test, NMO-rats performance was lower compared to the controls (p = 0.0182). AQP4 expression, and myelin and axonal integrity were preserved in AQP4-Ig

  3. Immunotherapies in neuromyelitis optica spectrum disorder: efficacy and predictors of response.

    Science.gov (United States)

    Stellmann, Jan-Patrick; Krumbholz, Markus; Friede, Tim; Gahlen, Anna; Borisow, Nadja; Fischer, Katrin; Hellwig, Kerstin; Pache, Florence; Ruprecht, Klemens; Havla, Joachim; Kümpfel, Tania; Aktas, Orhan; Hartung, Hans-Peter; Ringelstein, Marius; Geis, Christian; Kleinschnitz, Christoph; Berthele, Achim; Hemmer, Bernhard; Angstwurm, Klemens; Young, Kim Lea; Schuster, Simon; Stangel, Martin; Lauda, Florian; Tumani, Hayrettin; Mayer, Christoph; Zeltner, Lena; Ziemann, Ulf; Linker, Ralf Andreas; Schwab, Matthias; Marziniak, Martin; Then Bergh, Florian; Hofstadt-van Oy, Ulrich; Neuhaus, Oliver; Zettl, Uwe; Faiss, Jürgen; Wildemann, Brigitte; Paul, Friedemann; Jarius, Sven; Trebst, Corinna; Kleiter, Ingo

    2017-08-01

    To analyse predictors for relapses and number of attacks under different immunotherapies in patients with neuromyelitis optica spectrum disorder (NMOSD). This is a retrospective cohort study conducted in neurology departments at 21 regional and university hospitals in Germany. Eligible participants were patients with aquaporin-4-antibody-positive or aquaporin-4-antibody-negative NMOSD. Main outcome measures were HRs from Cox proportional hazard regression models adjusted for centre effects, important prognostic factors and repeated treatment episodes. 265 treatment episodes with a mean duration of 442 days (total of 321 treatment years) in 144 patients (mean age at first attack: 40.9 years, 82.6% female, 86.1% aquaporin-4-antibody-positive) were analysed. 191 attacks occurred during any of the treatments (annual relapse rate=0.60). The most common treatments were rituximab (n=77, 111 patient-years), azathioprine (n=52, 68 patient-years), interferon-β (n=32, 61 patient-years), mitoxantrone (n=34, 32.1 patient-years) and glatiramer acetate (n=17, 10 patient-years). Azathioprine (HR=0.4, 95% CI 0.3 to 0.7, p=0.001) and rituximab (HR=0.6, 95% CI 0.4 to 1.0, p=0.034) reduced the attack risk compared with interferon-β, whereas mitoxantrone and glatiramer acetate did not. Patients who were aquaporin-4-antibody-positive had a higher risk of attacks (HR=2.5, 95% CI 1.3 to 5.1, p=0.009). Every decade of age was associated with a lower risk for attacks (HR=0.8, 95% CI 0.7 to 1.0, p=0.039). A previous attack under the same treatment tended to be predictive for further attacks (HR=1.5, 95% CI 1.0 to 2.4, p=0.065). Age, antibody status and possibly previous attacks predict further attacks in patients treated for NMOSD. Azathioprine and rituximab are superior to interferon-β. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  4. Connexin 43 astrocytopathy linked to rapidly progressive multiple sclerosis and neuromyelitis optica.

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    Katsuhisa Masaki

    Full Text Available BACKGROUND: Multiple sclerosis (MS and neuromyelitis optica (NMO occasionally have an extremely aggressive and debilitating disease course; however, its molecular basis is unknown. This study aimed to determine a relationship between connexin (Cx pathology and disease aggressiveness in Asian patients with MS and NMO. METHODS/PRINCIPAL FINDINGS: Samples included 11 autopsied cases with NMO and NMO spectrum disorder (NMOSD, six with MS, and 20 with other neurological diseases (OND. Methods of analysis included immunohistochemical expression of astrocytic Cx43/Cx30, oligodendrocytic Cx47/Cx32 relative to AQP4 and other astrocytic and oligodendrocytic proteins, extent of demyelination, the vasculocentric deposition of complement and immunoglobulin, and lesion staging by CD68 staining for macrophages. Lesions were classified as actively demyelinating (n=59, chronic active (n=58 and chronic inactive (n=23. Sera from 120 subjects including 30 MS, 30 NMO, 40 OND and 20 healthy controls were examined for anti-Cx43 antibody by cell-based assay. Six NMO/NMOSD and three MS cases showed preferential loss of astrocytic Cx43 beyond the demyelinated areas in actively demyelinating and chronic active lesions, where heterotypic Cx43/Cx47 astrocyte oligodendrocyte gap junctions were extensively lost. Cx43 loss was significantly associated with a rapidly progressive disease course as six of nine cases with Cx43 loss, but none of eight cases without Cx43 loss regardless of disease phenotype, died within two years after disease onset (66.7% vs. 0%, P=0.0090. Overall, five of nine cases with Cx43 loss and none of eight cases without Cx43 loss had distal oligodendrogliopathy characterized by selective myelin associated glycoprotein loss (55.6% vs. 0.0%, P=0.0296. Loss of oligodendrocytic Cx32 and Cx47 expression was observed in most active and chronic lesions from all MS and NMO/NMOSD cases. Cx43-specific antibodies were absent in NMO/NMOSD and MS patients. CONCLUSIONS

  5. Diffusion-weighted imaging helps differentiate multiple sclerosis and neuromyelitis optica-related acute optic neuritis.

    Science.gov (United States)

    Wan, Hailin; He, Huijin; Zhang, Fang; Sha, Yan; Tian, Guohong

    2017-06-01

    To evaluate the apparent diffusion coefficient (ADC) values between multiple sclerosis (MS) and neuromyelitis optica (NMO)-related acute optic neuritis (ON) patients and predict their optic nerve atrophy of optic coherence tomography (OCT) parameters. Nineteen MS and 15 NMO-related acute ON patients who underwent a diffusion-weighted imaging sequence in 3.0 Tesla MR scanner and a follow-up OCT examination after 6 months were included. The ADC values, thickness of the retinal nerve fiber layer (RNFL) and the macular ganglion cell complex (GCC) between MS and NMO related ON were assessed. The mean ADC value of the NMO-ON, (0.691 ± 0.195[SD]) × 10 -3 mm 2 /s, was significantly smaller (P = 0.0133) than that of MS-ON. The mean ADC value of MS-ON, (0.879 ± 0.144) × 10 -3 mm 2 /s, was significantly smaller (P < 0.0001) than that of control group, (1.025 ± 0.067) × 10 -3 mm 2 /s. Using an ADC value smaller than 0.830 × 10 -3 mm 2 /s as the threshold value for differentiating MS-ON from NMO-ON patients, the highest accuracy of 76.7%, with 75.0% sensitivity and 78.3% specificity, was obtained. The ADC value measured at the acute stage of ON was correlated with the thickness of the RNFL (r = 0.441; P = 0.006) and the GCC (r = 0.526; P < 0.0001) after 6 months. The ADC value might be helpful for differentiating MS-ON from NMO-ON patients. The decreased ADC value was correlated with optic nerve atrophy on OCT. 3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;45:1780-1785. © 2016 International Society for Magnetic Resonance in Medicine.

  6. Ring-enhancing spinal cord lesions in neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Zalewski, Nicholas L; Morris, Padraig P; Weinshenker, Brian G; Lucchinetti, Claudia F; Guo, Yong; Pittock, Sean J; Krecke, Karl N; Kaufmann, Timothy J; Wingerchuk, Dean M; Kumar, Neeraj; Flanagan, Eoin P

    2017-03-01

    We assessed the frequency and characteristics of ring-enhancing spinal cord lesions in neuromyelitis optica spectrum disorder (NMOSD) myelitis and myelitis of other cause. We reviewed spinal cord MRIs for ring-enhancing lesions from 284 aquaporin-4 (AQP4)-IgG seropositive patients at Mayo Clinic from 1996 to 2014. Inclusion criteria were as follows: (1) AQP4-IgG seropositivity, (2) myelitis attack and (3) MRI spinal cord demonstrating ring-enhancement. We identified two groups of control patients with: (1) longitudinally extensive myelopathy of other cause (n=66) and (2) myelitis in the context of a concurrent or subsequent diagnosis of multiple sclerosis (MS) from a population-based cohort (n=30). Ring-enhancement was detected in 50 of 156 (32%) myelitis episodes in 41 patients (83% single; 17% multiple attacks). Ring-enhancement was noted on sagittal and axial images in 36 of 43 (84%) ring enhancing myelitis episodes and extended a median of two vertebral segments (range, 1-12); in 21 of 48 (44%) ring enhancing myelitis episodes, the ring extended greater than or equal to three vertebrae. Ring-enhancement was accompanied by longitudinally extensive (greater than or equal to three vertebral segments) T2-hyperintensity in 44 of 50 (88%) ring enhancing myelitis episodes. One case of a spinal cord biopsy during ring-enhancing myelitis revealed tissue vacuolation and loss of AQP4 immunoreactivity with preserved axons. The clinical characteristics of ring-enhancing myelitis episodes did not differ from non-ring-enhancing episodes. Ring-enhancing spinal cord lesions were more common in NMOSD than other causes of longitudinally extensive myelopathy (50/156 (32%) vs 0/66 (0%); p≤0.001) but did not differ between NMOSD and MS (50/156 (32%) vs 6/30 (20%); p=0.20). Spinal cord ring-enhancement accompanies one-third of NMOSD myelitis episodes and distinguishes NMOSD from other causes of longitudinally extensive myelopathies but not from MS. Published by the BMJ Publishing

  7. Elevated Plasma Chemokines for Eosinophils in Neuromyelitis Optica Spectrum Disorders during Remission

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    Yanping Tong

    2018-02-01

    Full Text Available BackgroundA prominent pathological feature of neuromyelitis optica spectrum disorders (NMOSD is markedly greater eosinophilic infiltration than that seen in other demyelinating diseases, like multiple sclerosis (MS. Eosinophils express the chemokine receptor CCR3, which is activated by eotaxins (CCL11/eotaxin-1, CCL24/eotaxin-2, CCL26/eotaxin-3 and CCL13 [monocyte chemoattractant protein (MCP-4]. Moreover, CCL13 is part of the chemokine set that activates CCR2. The present study aimed to evaluate plasma levels of eotaxins (CCL11, CCL24, and CCL26 and MCPs (CCL13, CCL2, CCL8, and CCL7 in patients with NMOSD during remission.MethodsHealthy controls (HC; n = 30 and patients with MS (n = 47 and NMOSD (n = 58 in remission were consecutively enrolled in this study between January 2016 and August 2017. Plasma CCL11, CCL24, CCL26, CCL2, CCL8, CCL7, CCL13, tumor necrosis factor (TNF-α, and interleukin (IL-1β levels were detected using the human cytokine multiplex assay.ResultsPlasma CCL13, CCL11, and CCL26 levels were all significantly higher in patients with NMOSD than in HC and patients with MS. No significant differences were found in the CCL13, CCL11, or CCL26 levels between patients with NMOSD receiving and not receiving immunosuppressive therapy. The plasma levels of TNF-α and IL-1β, which stimulate the above chemokines, were higher in patients with NMOSD than in HC. There was no difference in CCL24 levels among the three groups. In most cases, the CCL7 levels were below the threshold value of the human cytokine multiplex assay, which is in line with other studies. Adjusted multiple regression analyses showed a positive association of CCL13 levels with the number of relapses after controlling gender, age, body mass index, and disease duration in patients with NMOSD.ConclusionThe study indicates that in NMOSD, the overproduction of cytokines such as IL-1β and TNF-α during remission stimulates eosinophilic chemoattractants such as

  8. Retinal ganglion cell-inner plexiform and nerve fiber layers in neuromyelitis optica.

    Science.gov (United States)

    Hu, Sai-Jing; Lu, Pei-Rong

    2018-01-01

    To determine the thickness of the retinal ganglion cell-inner plexiform layer (GCIPL) and the retinal nerve fiber layer (RNFL) in patients with neuromyelitis optica (NMO). We conducted a cross-sectional study that included 30 NMO patients with a total of 60 eyes. Based on the presence or absence of optic neuritis (ON), subjects were divided into either the NMO-ON group (30 eyes) or the NMO-ON contra group (10 eyes). A detailed ophthalmologic examination was performed for each group; subsequently, the GCIPL and the RNFL were measured using high-definition optical coherence tomography (OCT). In the NMO-ON group, the mean GCIPL thickness was 69.28±21.12 µm, the minimum GCIPL thickness was 66.02±10.02 µm, and the RNFL thickness were 109.33±11.23, 110.47±3.10, 64.92±12.71 and 71.21±50.22 µm in the superior, inferior, temporal and nasal quadrants, respectively. In the NMO-ON contra group, the mean GCIPL thickness was 85.12±17.09 µm, the minimum GCIPL thickness was 25.39±25.1 µm, and the RNFL thicknesses were 148.33±23.22, 126.36±23.45, 82.21±22.30 and 83.36±31.28 µm in the superior, inferior, temporal and nasal quadrants, respectively. In the control group, the mean GCIPL thickness was 86.98±22.37 µm, the minimum GCIPL thickness was 85.28±10.75 µm, and the RNFL thicknesses were 150.22±22.73, 154.79±60.23, 82.33±7.01 and 85.62±13.81 µm in the superior, inferior, temporal and nasal quadrants, respectively. The GCIPL and RNFL were thinner in the NMO-ON contra group than in the control group ( P deviation (MD) and corrected pattern standard deviation (PSD) in the NMO-ON group ( P <0.05). The thickness of the GCIPL and RNFL, as measured using OCT, may indicate optic nerve damage in patients with NMO.

  9. Flujo de compuestos organoclorados en las cadenas troficas de la cienaga de Santa Marta

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    Hernado Campos Néstor

    1993-12-01

    Full Text Available Monthly samples of seston and fish species of different throphic levels were done at the Ciénaga Grande de Santa Marta in orderto describe organochlorinated compounds dynamics. The fish used were: atlantic anchoveta, mulletand catfish. The organochlorinated contents were determined by gas-liquid chromatography using n-Hexane and Acetonitrilo as extraction solvents. The results were compared to 14 organochlorinated pure patrons. The following accumulations patterns were found: atlantic nchoveta 2240 times, mullet 2343 times and catfish 21800 times and the magnifying factors among the differents thropic levels: mullet/atlantic anchoveta = 1.47, catfish/atlantic anchoveta = 2.6 and catfish/mullet = 3.3 The transport model of the organochlorinated compounds in the Cienaga Grande de Santa Marta is described bassed in these results.Con el fin de describir la dinámica de los compuestos organoclorados a través de la red trófica de la Ciénaga Grande de Santa Marta, se adelantaron muestreos simultáneos del seston y de peces de diferentes niveles tróficos: bocona (cetengraulis edentulus planctófago; lisa (Mugil incilis detritívoro; el chivo (Ariopsis boniiíei; carnívoro. Se determinaron los contenidos de organoclorados por cromatografía gas-líquido, empleando n-hexano y acetonitrilo como solventes de extracción y se compararon con 14 patrones puros de organoclorados. Los factores de acumulación para la bocona son de 2240 veces, para la lisa 2343 y para el chivo 21800. Los factores de magnificación entre los diferentes niveles tróficos son lisa/bocona = 1.47; chivo/lisa = 3.3; chivo/bocona = 2.6. Se describe el modelo de flujos de los organoclorados en la Ciénaga Grande de Santa Marta con base en estos resultados.

  10. Compuestos fenólicos del olivo (Olea europea

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    Maestro-Durán, R.

    1994-08-01

    Full Text Available Certain plant properties, such as the colour, the nutritional value, the resistance to microorganisms, the pharmacologic effects and the organoleptic character, are due to the phenolic compounds. It is interesting the study of phenolic compounds from olive because they:

    -Inhibit Gram+ microorganisms, such as Lactobacillus, which are involved in the fermentation of the olive fruit. -Inhibit the activity of cellulases and other enzymes. -Contribute to the stability and organoleptic character of virgin olive oil. -Inhibit the effect of microorganisms involved in the anaerobic depuration of vegetation water. Thus, the phenolic compounds are the major bothersome contaminants of these wastewater. -Have pharmacologic properties (to reduce blood pressure levels. -Are natural antioxidants.

    In the present review we describe the composition of the phenolic compounds from the olive fruit (pulp and seed, the olive oil and its by-products (vegetation water and rape and the olive leaves.

    Ciertas propiedades de las plantas, como el color, valor nutricional, autoprotección contra microorganismos, propiedades farmacológicas o caracteres organolépticos, son debidas a los compuestos fenólicos. Su estudio, en el caso del olivo, es de gran interés por diversas razones:

    -Por su carácter antibiótico, los fenoles de la aceituna inhiben los microorganismos Gram+, como Lactobacillus, necesarios para la fermentación de aceitunas de mesa. -Inhiben la acción de las celulasas y otras enzimas. -Son los responsables de la alta estabilidad de los aceites vírgenes de oliva, así como de alguno de sus caracteres organolépticos. -Inhiben la acción de los microorganismos responsables de la depuración anaerobia de los alpechines y son las sustancias contaminantes de estas aguas residuales cuya degradación para eliminar la DQO presenta más dificultades. -Tienen propiedades

  11. Procesado y propiedades de impacto de materiales compuestos laminados de base hierro

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    Carreño, F.

    2001-04-01

    Full Text Available A seven layers steel based laminated composite (four ultra-high carbon steel, UHCS, layers and three mild steel, MS, layers has been processed by rolling bonding and its microstructure and impact properties have been studied. Suitable parameters of temperature and thickness reduction were selected to obtain a finer microstructure relative to the original material components. This finer microstructure induces improved mechanical properties. Charpy impact tests values in both "crack arrester" and "crack divider" orientations improve the values of the UHCS constituent material. Furthermore, the crack arrester orientation value exceed that of the MS material. The delamination, which is controlled by interface bonding, plays a key role deflecting the crack, absorbing energy and imposing the nucleation of new cracks in the next material layer.

    Se ha procesado un material compuesto laminado de base hierro, de 7 capas alternas de dos aceros diferentes (cuatro capas de acero de ultra-alto contenido en carbono, AUAC, y tres de acero suave, AS, mediante unión por laminación y se ha estudiado su microestructura y propiedades de impacto. Se eligieron los parámetros adecuados de temperatura y de reducción de espesor para obtener una microestructura más fina que la de los aceros constituyentes originales, lo que induce una mejora en las propiedades mecánicas. Los valores de energía absorbida en el ensayo Charpy, tanto en la dirección "en paralelo" como "en serie", han mejorado sustancialmente el valor asociado al AU AC monolítico. Además, el valor obtenido en la dirección "en serie" es superior al del AS. Se observa que la delaminación, que depende de la unión de las intercaras, juega un papel importante en la deflexión de las fisuras, absorbiendo energía e imponiendo sucesivas nucleaciones de grietas en las siguientes capas.

  12. Efeito do tratamento alcalino de fibras de Curauá sobre as propriedades de compósitos de matriz biodegradável

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    Lílian Vanessa Rossa Beltrami

    2014-06-01

    Full Text Available Neste trabalho avaliou-se a influência do tratamento alcalino das fibras de curauá, nas concentrações de 1, 5 e 10%(m/v de NaOH, nas propriedades dos compósitos com matriz de PHBV e 20% m/m de fibras de curauá. Os compósitos foram moldados por extrusão e injeção e avaliadas suas as propriedades morfológicas, térmicas e mecânicas. Os resultados de FTIR mostraram que o tratamento alcalino promoveu modificações na estrutura das fibras de curauá, comprovadas pela remoção da hemicelulose e da lignina, evidenciadas pela ausência das bandas típicas destes compostos. Nos compósitos com fibras de curauá tratadas com solução de NaOH na concentração de 5% apresentaram um aumento de 30% na resistência à flexão e 12% na resistência ao impacto, quando comparados aos compósitos com fibras sem tratamento. Estes resultados indicam que o tratamento alcalino promoveu uma melhoria na adesão das fibras na matriz, o que melhorou significativamente as propriedades mecânicas dos compósitos.

  13. Influencia de compuestos azúcares y no azúcares en la calidad industrial de caña de azúcar en Tucumán (R. Argentina: Parte 1: caña limpia y despuntada Influence of sugar and nonsugar compounds on sugarcane industrial quality in Tucumán (Argentine Republic

    Directory of Open Access Journals (Sweden)

    B. Silvia Zossi

    Full Text Available Se estudió la concentración de compuestos azúcares y no azúcares, especialmente los que influyen en la formación del color y otros que inciden en el proceso industrial de producción de azúcar blanco directo, de las cuatro variedades comerciales de caña más difundidas en Tucumán (R. Argentina: TUCCP 77-42, LCP 85-384, CP 65-357 y RA 87-3. Estos ensayos fueron realizados durante las zafras 2004 a 2007 en caña limpia y despuntada. Los parámetros analizados fueron: extracción de jugo, Brix %, pol % en jugo y en caña, sacarosa y azúcar recuperable. Se estudiaron no azúcares inorgánicos, tales como cenizas, fosfato y sílice, y no azúcares orgánicos: fibra, almidón, compuestos antocianos y fenoles, nitrógeno amínico, ácidos cis y trans-aconítico, "indicator value" y color. De las cuatro variedades analizadas, la que mejor comportamiento presentó para producir azúcar blanco directo fue LCP 85-384, por su alto contenido en sacarosa y bajo contenido de componentes no azúcares. El segundo lugar le correspondió a la variedad RA 87-3, seguida por CP 65-357 y TUCCP 77-42.The concentration of sugar and nonsugar compounds, especially those which play a part in colour formation and others which affect direct white sugar manufacturing process, was studied in the four commercial cane varieties most widely grown in Tucumán (Argentine Republic: TUCCP 77-42, LCP 85-384, CP 65-357 and RA 87-3. Trials with clean cane were conducted during the 2004-2007 harvests. Analyzed parameters were: juice extraction, Brix %, pol % in juice and cane, sucrose and sugar recovery. Inorganic nonsugar compounds, such as ash, phosphate and silica, as well as organic ones, such as fibre, starch, anthocyanin and phenolic compounds, amino nitrogen, cis and trans-aconitic acids, indicator value and colour, were studied. Results showed that LCP 85-384 variety had the best factory performance to produce direct white sugar because of its high sucrose and low

  14. CONSUMO DE FIBRA DIETÉTICA EN LACTANTES MENORES DE 2 AÑOS Y ESTREÑIMIENTO FUNCIONAL

    OpenAIRE

    Carlos Alberto Velasco Benítez; Sandra Carolina Giraldo Lora

    2014-01-01

    Introducción: La inclusión de la fibra dietética (FD), tiene múltiples beneficios sobre la salud del ser humano; sin embargo, en pediatría, existen grandes brechas concernientes a la relación de fibra y estreñimiento. Objetivo: Describir el hábito intestinal en lactantes . Se tuvo en cuenta la alimentación con leche materna, el tiempo de inicio de alimentación complementaria y el antecedente de madre o cuidador con EF. Los resultados son expresados como X±DS. El análisis estadístico incluyó X...

  15. Utilização de pós residuais e fibra de sisal em blocos de concreto

    OpenAIRE

    Indara Soto Izquierdo

    2015-01-01

    A pesquisa tem como enfoque fundamental a aplicação de novos materiais alternativos para uma construção sustentável. Pós residuais, provenientes do resíduo orgânico e do setor mineral, e fibras de sisal constituem bons exemplos de materiais não convencionais. Dessa forma, o objetivo principal foi avaliar a incorporação dos pós residuais e da fibra de sisal no concreto para a fabricação de blocos de concreto e elementos de alvenaria. Foram estudados três relações cimento: agregado, de 1:15, 1:...

  16. Método para la formulación de hormigones de fibras metálicas

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    Serna Ros, Pedro

    1984-06-01

    Full Text Available In the work we are presenting, we have set ourselves the target of determining a practical method for ascertaining the dosage of fibrous concrete. To do this, as in any problem regarding dosage, we shall start from the possibilities of supply, which will be conditioned by the nature of the aggregates to be used, of certain technical restrictions imposed by the admixtures and of the carrying out requirements which will set the concrete workability. The first part of our study amounts to determining the optimal percentages for each aggregate and the water-cement ratio, starting with the dosage of cement established initially and for each fibre content proposed. In the second part, we shall develop the study of acceptable limits of fibre content, in order to prevent 'balls of fibre' from forming.

    En los trabajos que presentamos nos hemos planteado el objetivo de determinar un método práctico de dosificación de hormigones de fibras. Para ello partiremos, como en cualquier problema de dosificación, de unas posibilidades de suministro que nos condicionarán la naturaleza de los áridos a utilizar, de unas limitaciones técnicas impuestas por los aditivos, y de unas necesidades de puesta en obra que nos fijarán la trabajabilidad del hormigón. La primera parte de nuestro trabajo se reduce a determinar, a partir de la dosificación en cemento fijada inicialmente, y para cada contenido en fibras propuesto, los porcentajes óptimos de cada uno de los áridos y la relación agua/cemento. En la segunda parte desarrollaremos el estudio de los límites admisibles del contenido en fibras, para evitar la formación de "pelotas de fibras".

  17. Neuropatia experimental por DDT: análise de nervo por microdissecção de fibras

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    Edison Matos Nóvak

    1984-09-01

    Full Text Available Estudou-se o nervo gênito-femural do rato albino submetido a intoxicação crônica por DDT, administrado por 180 dias na dose de 5 mg/kg de peso via oral. Os resultados mostraram proporção anormal de fibras tipo C, sendo sugerido ocorrer degeneração tipo axonal determinada pelo DDT.

  18. Studio dei fattori che influenzano la digeribilità della fibra nella bovina da latte: approcci dinamici

    OpenAIRE

    Bonfante, Elena

    2017-01-01

    I ruminanti sono altamente specializzati nella digestione della fibra. In condizioni di ottima funzionalità digestiva, sono le particelle di foraggio ad essere trattenute per lungo tempo nel rumine dove possono essere degradate dai batteri cellulosolitici. Nonostante queste conoscenze, la stima della degradabilità ruminale delle porzioni potenzialmente degradabili delle fibre è stata notevolmente sottostimata da taluni modelli dinamici di razionamento. Studi più recenti realizzati da Kriz...

  19. Qualitative and quantitative autoradiographic investigations on DNA-repair in the pars optica retinae of the rabbit

    International Nuclear Information System (INIS)

    Kellner, G.; Reindl, E.; Pichler, L.; Hofer, H.

    1974-01-01

    In vitro and in vivo investigations into the incorporation of 3 H-thymidine into the nuclei of pars optica retinae of rabbits after β-irradiation with 60 krad were performed. The results of the in vitro and in vivo experiments are comparable with the in vitro data showing smaller statistical deviations. The rate comparable with the in vitro data showing smaller statistical deviations. The rate of incorporation of 3 H-thymidine into the nuclei of Ggl. opticum and Ggl. retinae is about the same, but it is significantly lower in the nuclei of photoreceptor cells by one order of magnitude. The in vitro experiment demonstrates that ganglion cells are capable of DNA repair even after circulation has been stopped for 15 or more minutes. (author)

  20. Serum 25-hydroxyvitamin D3 is associated with disease status in patients with neuromyelitis optica spectrum disorders in south China.

    Science.gov (United States)

    Shan, Yilong; Tan, Sha; Zhang, Lei; Huang, Jianhua; Sun, Xiaobo; Wang, Yuge; Cai, Wei; Qiu, Wei; Hu, Xueqiang; Lu, Zhengqi

    2016-10-15

    Here, we investigated the relationship between serum 25-hydroxyvitamin D 3 (25[OH]D 3 ) levels and neuromyelitis optica spectrum disorder (NMOSD). Patients with NMOSD had lower 25(OH)D 3 levels than healthy people, with lower levels in patients in the acute phase than those in remission. An inverse correlation was found between 25(OH)D 3 and Expanded Disability Status Scale scores of patients during attacks. Higher serum 25(OH)D 3 levels were associated with greater amelioration of symptoms during corticosteroid therapy. These results indicate that decreased vitamin D may be involved in NMOSD pathogenesis, and that 25(OH)D 3 serum levels may reflect the severity of NMOSD in the acute phase. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. A case of seropositive Neuromyelitis Optica in a paediatric patient with co-existing acute nephrotic syndrome.

    Science.gov (United States)

    Volkman, Thomas; Hemingway, Cheryl

    2017-11-01

    Neuromyelitis optica (NMO) and NMO spectrum disorder (NMOSD) is a rare relapsing autoimmune disease of the central nervous system constituting less than 1% of demyelinating diseases (Jeffery and Buncic, 1996). It preferentially affects the optic nerves and spinal cord, with the brain parenchyma generally spared. Demyelinating lesions are characterised by longitudinally extensive transverse myelitis (LETM) and often longitudinally extensive optic neuritis. Following the discovery of a novel pathogenic antibody, Aquaporin 4 in 2004 (Lennon et al., 2004) this disease has been seen as a separate entity from Multiple Sclerosis (MS). We report the case of a severe AQP4 IgG case of NMO in a 10 year old child. This case unusually had a coexisting diagnosis of acute nephrotic syndrome which has only been reported once previously in the literature 2 . This article will examine some of the treatment challenges and the spectrum of co-existing autoimmune disease in NMOSD. Copyright © 2017. Published by Elsevier B.V.

  2. CFHR1-Modified Neural Stem Cells Ameliorated Brain Injury in a Mouse Model of Neuromyelitis Optica Spectrum Disorders.

    Science.gov (United States)

    Shi, Kaibin; Wang, Zhen; Liu, Yuanchu; Gong, Ye; Fu, Ying; Li, Shaowu; Wood, Kristofer; Hao, Junwei; Zhang, Guang-Xian; Shi, Fu-Dong; Yan, Yaping

    2016-11-01

    A major hurdle for effective stem cell therapy is ongoing inflammation in the target organ. Reconditioning the lesion microenvironment may be an effective way to promote stem cell therapy. In this study, we showed that engineered neural stem cells (NSCs) with complement factor H-related protein 1, a complement inhibitor protein, can attenuate inflammatory infiltration and immune-mediated damage of astrocytes, an important pathogenic progress in patients with neuromyelitis optica spectrum disorders. Furthermore, we demonstrated that transplantation of the complement factor H-related protein 1-modified NSCs effectively blocked the complement activation cascade and inhibited formation of the membrane attack complex, thus contributing to the protection of endogenous and transplanted NSC-differentiated astrocytes. Therefore, manipulation of the lesion microenvironment contributes to a more effective cell replacement therapeutic strategy for autoimmune diseases of the CNS. Copyright © 2016 by The American Association of Immunologists, Inc.

  3. COMPORTAMIENTO DEL CONCRETO REFORZADO CON FIBRAS DE ACERO ZP-306 SOMETIDO A ESFUERZOS DE COMPRESIÓN

    Directory of Open Access Journals (Sweden)

    Lina P. Gallo-Arciniegas

    2013-01-01

    Full Text Available En Colombia, el uso del concreto reforzado con fibras de acero (CRFA es muy limitado, debido a que en el país no existe suficiente evidencia experimental y requisitos reglamentarios al respecto. En el artículo se presentan los resultados de una investigación experimental y analítica sobre el comportamiento del CRFA elaborado con fibras ZP-306, sometidas a esfuerzos de compresión. El estudio involucra la revisión y discusión de los modelos disponibles en la literatura, así como un programa experimental que incluye el ensayo de 48 especímenes. A partir de un análisis de regresión de los datos medidos, se proponen ecuaciones para estimar las principales propiedades mecánicas del CRFA, tales como resistencia a compresión, módulo de elasticidad y relación de Poisson. Las ecuaciones correlacionan las propiedades mecánicas con las principales características de las fibras de acero, tales como dosificación y relación de aspecto.

  4. Importância da fibra na nutrição de coelhos Importance of fibre in rabbit nutrition

    Directory of Open Access Journals (Sweden)

    Alexandra del Pilar Naranjo Herrera

    2001-06-01

    Full Text Available Os coelhos, por serem herbívoros não ruminantes, podem ser alimentados com considerável quantidade de alimentos fibrosos. No entanto, não apresentam eficiência tão grande para utilizar essa fibra sendo, nesse aspecto, inferior aos ruminantes e, inclusive, aos suínos. Por outro lado, a fibra, apesar de seu escasso valor nutritivo, apresenta valor lastre, sendo importante, pois, na regulação do trânsito da digesta e na prevenção de distúrbios digestivos. Assim, o objetivo deste artigo é revisar alguns aspectos da composição química da fibra e de sua digestão pelos coelhos, bem como a sua relação com outros nutrientes da dieta, como proteína e energia.Rabbits are monogastric herbivorous that intake quantity significative of fibrous feed. However they not show efficiency to degrate this fibre, being less capacity, in this aspect, that ruminants and inclusively, of the swine. For other hand, the fibre have ballast value, being important in the transit digestive regulation and prevention of digestive disturb. Thus, the objetive of this paper is to review some aspects of chemistry composition of fibre and it's digestion for rabbits and it's relation with other components of diet like protein and energy.

  5. Catalizadores soportados en carbón activado para la oxidación total de Compuestos Orgánicos Volátiles

    OpenAIRE

    Abdelouahab Reddam, Zinab

    2015-01-01

    Los compuestos orgánicos volátiles (COVs) forman un grupo importante de contaminantes atmosféricos. Estos compuestos, precursores de la formación de ozono troposférico, no sólo son perjudiciales para los seres humanos, sino que también pueden alterar la actividad fotosintética de las plantas y contribuyen al calentamiento global del planeta. Por ello, se han desarrollado varias técnicas para su eliminación en corrientes de aire contaminadas, de las cuales la oxidación catalítica ha demostrado...

  6. Feixes de fibras Lignocelulósicas refinadas mecanicamente em compósitos cimentícios para avaliação da resistência à tração

    Directory of Open Access Journals (Sweden)

    Flávio Airton knuth

    2017-07-01

    Full Text Available As fibras vegetais têm características particulares em relação a outros tipos de fibras usadas em compósitos. Os estudos utilizam, em sua maioria, fibras cuja lignina fora previamente removida pelo processo de polpação. Segundo a literatura, a lignina prejudica a ancoragem fibra-matriz. No entanto, sem a lignina, é necessário que seja feito tratamento superficial no conjunto fibroso. Isso por que as fibras sofrem processo de inchamento e retração no interior da matriz devido a seu caráter hidrofílico, o que diminui sua vida útil. No entanto, a despeito das considerações literárias, esse trabalho se propõe a fazer uso da vantagem de proteção, estruturação e impermeabilização que a lignina exerce sobre as fibras vegetais. Isso implica na necessidade de suprir a redução da resistência do compósito, especialmente à tração, que a lignina causa pela sua atuação negativa na ancoragem fibra-matriz. Para tanto, fibras lignocelulósicas extraídas de talos de banana foram submetidas a processo de refinamento mecânico. Segundo a literatura, a fibra sofre modificações na sua parede externa quando submetida a esse refinamento. Ao final do processo, foram obtidas fibras com formato helicoidal e superfície corrugada o que resultou em maior aderência no conjunto fibra-matriz. As fibras submetidas ao maior grau de refinamento aumentaram a resistência do compósito à tração na compressão diametral em 40% em relação a corpo de prova de cimento puro.

  7. Enhancing Brain Lesions during Acute Optic Neuritis and/or Longitudinally Extensive Transverse Myelitis May Portend a Higher Relapse Rate in Neuromyelitis Optica Spectrum Disorders.

    Science.gov (United States)

    Orman, G; Wang, K Y; Pekcevik, Y; Thompson, C B; Mealy, M; Levy, M; Izbudak, I

    2017-05-01

    Neuromyelitis optica spectrum disorders are inflammatory demyelinating disorders with optic neuritis and/or longitudinally extensive transverse myelitis episodes. We now know that neuromyelitis optica spectrum disorders are associated with antibodies to aquaporin-4, which are highly concentrated on astrocytic end-feet at the blood-brain barrier. Immune-mediated disruption of the blood-brain barrier may manifest as contrast enhancement on brain MR imaging. We aimed to delineate the extent and frequency of contrast enhancement on brain MR imaging within 1 month of optic neuritis and/or longitudinally extensive transverse myelitis attacks and to correlate contrast enhancement with outcome measures. Brain MRIs of patients with neuromyelitis optica spectrum disorders were evaluated for patterns of contrast enhancement (periependymal, cloudlike, leptomeningeal, and so forth). The Fisher exact test was used to evaluate differences between the proportion of contrast enhancement in patients who were seropositive and seronegative for aquaporin-4 antibodies. The Mann-Whitney test was used to compare the annualized relapse rate and disease duration between patients with and without contrast enhancement and with and without seropositivity. Brain MRIs of 77 patients were evaluated; 59 patients (10 males, 49 females) were scanned within 1 month of optic neuritis and/or longitudinally extensive transverse myelitis attacks and were included in the analysis. Forty-eight patients were seropositive, 9 were seronegative, and 2 were not tested for aquaporin-4 antibodies. Having brain contrast enhancement of any type during an acute attack was significantly associated with higher annualized relapse rates ( P = .03) and marginally associated with shorter disease duration ( P = .05). Having periependymal contrast enhancement was significantly associated with higher annualized relapse rates ( P = .03). Brain MRIs of patients with neuromyelitis optica spectrum disorders with contrast

  8. Serial quantitative MR assessment of optic neuritis in a case of neuromyelitis optica, using gadolinium-'enhanced' STIR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Barkhof, F.; Scheltens, P.; Valk, J. (Vrije Univ., Amsterdam (Netherlands). Dept. of Diagnostic Radiology); Waalewijn, C.; Uitdehaag, B.M.J.; Polman, C.H. (Vrije Univ., Amsterdam (Netherlands). Dept. of Neurology)

    1991-02-01

    A patient is presented with neuromyelitis optica. MR imaging, using a short inversion time inversion recovery (STIR) technique, clearly depicted the lesion in the left optic nerve. Subsequent serial STIR imaging, with and without Gadolinium-DTPA, allowed quantitative assessment of changes parallel to improved optic nerve function. STIR imaging is a sensitive technique to demonstrate optic nerve lesions, and enables quantitative assessment to be made of the effect of (steroid) medication. (orig.).

  9. Aplicações de fibras vegetais na secagem de concretos refratários Use of natural fibers to speed up the drying step of refractory castables

    Directory of Open Access Journals (Sweden)

    C. S. Isaac

    2004-06-01

    Full Text Available A secagem de concretos refratários é uma etapa crítica em seu processamento devido aos riscos de explosão durante a saída de água contida em sua estrutura. Para minimizar esses problemas e aumentar a velocidade de secagem, fibras poliméricas têm sido adicionadas às formulações de concreto. Uma variável importante a ser considerada no desempenho desse aditivo é o tipo de fibra utilizada. Trabalhos do grupo de pesquisa indicaram que fibras vegetais podem apresentar bom desempenho na geração de canais permeáveis. Esse fato, aliado à sua grande disponibilidade e baixo custo, sugere que estas fibras sejam uma alternativa interessante às fibras sintéticas utilizadas atualmente. Neste trabalho, comparou-se o desempenho de fibras vegetais com o do polipropileno utilizados como aditivos de secagem. Foram realizadas medidas de permeabilidade utilizando a Equação de Forchheimer, ensaios de permeametria em alta temperatura e análise termogravimétrica do concreto. As fibras foram caracterizadas por calorimetria exploratória diferencial e termogravimetria.The drying of refractory castables is a critical step during application due to the possibility of spalling. In order to decrease these risks and improve the drying rate, polymeric fibers have been added to the castables' formulation. The type of fiber is an important aspect to be studied. Authors' previous works indicated that vegetable fibers can be good candidates. This fact, associated with its wide availability and low cost, suggests that these fibers can be interesting substitutes to synthetic ones. In this work, vegetable and polypropylene fibers had their performance evaluated as drying agents. The results of permeability measurements and hot air permeametry were related with the thermogravimety of the fiber-containing castables. The fibers were characterized by differential scanning calorimetry and thermogravimetry.

  10. Comparison study of imaging features of multiple sclerosis and neuromyelitis optica

    International Nuclear Information System (INIS)

    Liu Jianguo; Zhang Hailing; Zheng Kuihong; Zhang Wenluo; Dong Qinwen; Qi Xiaokun

    2012-01-01

    Objective: To compare the imaging characteristics of multiple sclerosis (MS) and neuromyelitis optica (NMO) for better diagnosis and differential diagnosis. Methods: The brain and spinal MRI images of 60 MS and 48 NMO cases were retrospectively reviewed. The imaging characteristics including the predilection site, morphological features, enhancement manifestations were summarized. All data was analyzed by using t test and Chi square test with SPSS 13.0. Results: (1) The three top predilection sites of brain in head MRI of MS patients were periventricular white matter (34 cases in 60), subcortical white matter (27 cases in 60), brain stem (23 cases in 60). MS lesions also were found in basal ganglia, cerebellum, corpus callosum and thalamus,as well as cortex (9 cases in 60). By contrast, brain lesions were observed in 59.4% (19/32) of NMO patients, and the three top predilection sites of NMO by turns were brain stem (13 cases in 19), periventricular white matter (12 cases in 19), subcortical white matter (7 cases in 19). Furthermore, the lesions surrounding third ventricle (6 cases in 19) and the tegmentum of brain stem near peri-aqueduct (8 cases in 19) in NMO were not found in patients of MS. The involvement of brain stem and thalamus was more frequent in NMO than in MS (χ 2 =5.267, 6.004, P<0.05, respectively). (2) The lesions of spinal cord in MS patients were typically oval, peripheral, and asymmetric, but in NMO patients they were longitudinally extensive and centrally located. The mean number of involved vertebral segments in NMO patients was significantly more than that in MS patients (7.3 vs 2.2, t=-9.288, P<0.01). Furthermore, the number of spinal cord lesions in MS patients was remarkably more than that in NMO (2.0 vs 1.3, t=4.565, P<0.01). The ratios of occurrence of spinal cord swelling and distension of NMO patients was 58.3% (28/48), which was significantly higher than 21.9% in MS (7/32, χ 2 =10.370, P<0.01). (3) The enhancement pattern in MS was

  11. Retinal ganglion cell-inner plexiform and nerve fiber layers in neuromyelitis optica

    Directory of Open Access Journals (Sweden)

    Sai-Jing Hu

    2018-01-01

    Full Text Available AIM: To determine the thickness of the retinal ganglion cell-inner plexiform layer (GCIPL and the retinal nerve fiber layer (RNFL in patients with neuromyelitis optica (NMO. METHODS: We conducted a cross-sectional study that included 30 NMO patients with a total of 60 eyes. Based on the presence or absence of optic neuritis (ON, subjects were divided into either the NMO-ON group (30 eyes or the NMO-ON contra group (10 eyes. A detailed ophthalmologic examination was performed for each group; subsequently, the GCIPL and the RNFL were measured using high-definition optical coherence tomography (OCT. RESULTS: In the NMO-ON group, the mean GCIPL thickness was 69.28±21.12 μm, the minimum GCIPL thickness was 66.02±10.02 μm, and the RNFL thickness were 109.33±11.23, 110.47±3.10, 64.92±12.71 and 71.21±50.22 μm in the superior, inferior, temporal and nasal quadrants, respectively. In the NMO-ON contra group, the mean GCIPL thickness was 85.12±17.09 μm, the minimum GCIPL thickness was 25.39±25.1 μm, and the RNFL thicknesses were 148.33±23.22, 126.36±23.45, 82.21±22.30 and 83.36±31.28 μm in the superior, inferior, temporal and nasal quadrants, respectively. In the control group, the mean GCIPL thickness was 86.98±22.37 μm, the minimum GCIPL thickness was 85.28±10.75 μm, and the RNFL thicknesses were 150.22±22.73, 154.79±60.23, 82.33±7.01 and 85.62±13.81 μm in the superior, inferior, temporal and nasal quadrants, respectively. The GCIPL and RNFL were thinner in the NMO-ON contra group than in the control group (P<0.05; additionally, the RNFL was thinner in the inferior quadrant in the NMO-ON group than in the control group (P<0.05. Significant correlations were observed between the GCIPL and RNFL thickness measurements as well as between thickness measurements and the two visual field parameters of mean deviation (MD and corrected pattern standard deviation (PSD in the NMO-ON group (P<0.05. CONCLUSION: The thickness of the GCIPL

  12. Infiltração de sal de alumínio em fibras de sisal para obtenção de fibras de alumina Infiltration of aluminum salt into sisal to produce alumina fibers

    Directory of Open Access Journals (Sweden)

    T. E. Andrade Jr.

    2005-03-01

    Full Text Available O sisal é um recurso estratégico para a região Nordeste e, particularmente, para o estado do Rio Grande do Norte, por ser uma cultura renovável e adaptada às condições do semi-árido. Em virtude das condições adversas de clima e solo, o sisal é, em algumas regiões, o único produto agrícola rentável passível de plantio. Agregar valor aos produtos manufaturados a partir do sisal contribui não só para o desenvolvimento científico e tecnológico da região, como também para a geração de renda para a população dos municípios potiguares produtores de sisal. Da planta extraem-se fibras ligninocelulósicas utilizadas na produção artesanal de cordas e industrial de mantas e tapetes. Uma outra alternativa é o aproveitamento da estrutura da fibra para a produção de fibras de alumina (Al2O3 pela biomodelagem. Este processo consiste na reprodução da estruturas natural do material de partida. O objetivo deste trabalho foi estudar as condições de infiltração da fibra de sisal com sal de alumínio para posterior conversão da estrutura em fibras de alumina. Inicialmente, as fibras de sisal foram pré-tratadas com hidróxido de sódio, infiltradas com uma solução saturada de sal de alumínio (Al2Cl6 e sinterizadas entre 1400 °C e 1650 °C. A caracterização das fibras de alumina foi feita por difração de raios X e microscopia eletrônica de varredura. Os resultados mostraram a conversão completa apenas da superfície da fibra de sisal em alfa-Al2O3, resultando em baixa resistência ao manuseio. Novos métodos de infiltração são propostos com o objetivo de reproduzir-se a estrutura interna da fibra de sisal, resultando em fibras materiais com melhor resistência mecânica.Sisal is a renewable agricultural resource adapted to the hostile climatic and soil conditions particularly encountered in the semi-arid areas of the state of Rio Grande do Norte, located in Northeastern Brazil. Consequently, sisal has played a

  13. Desarrollo de técnicas de extracción y análisis de antocianinas y compuestos fenólicos en Jaboticaba (Myrciaria Cauliflora)

    OpenAIRE

    Mera Morillo, Celia

    2015-01-01

    Desarrollo de técnicas de extracción mediante ultrasonidos y mediante fluidos presurizados para así, obtener las condiciones óptimas de extracción de las antocianinas mayoritarias y compuestos fenólicos totales presentes en la jaboticaba

  14. Morfologia e morfometria dos tipos de fibras do músculo reto abdominal de cadelas (Canis familiaris durante a gestação

    Directory of Open Access Journals (Sweden)

    Maila Karina Mattos de Brito

    2007-08-01

    Full Text Available Neste trabalho foram avaliadas as alterações morfológicas e o grau de hipertrofia das fibras de contração lentas (tipo I e rápidas (tipo II do músculo reto abdominal de cadelas adultas nas fases: pré-gestacional, 30 e 60 dias de gestação e 30 dias pós-parto (pp. Em todas essas fases, sob anestesia, foram removidas biópsias musculares, as quais foram congeladas. Cortes histológicos foram obtidos em um micrótomo e corados com hematoxilina e eosina (HE para a avaliação da morfologia. Outros cortes foram submetidos à ATPase miofibrilar (m-ATPase, após pré-incubação em meio alcalino (pH = 10,4 e em meio ácido (pH = 4,4, visando à identificação das fibras tipo I e II. Nas cadelas virgens, o tecido muscular revelou-se constituído por fibras com diferentes diâmetros, com contornos poligonais, tendo um ou mais núcleos periféricos. Estas características foram similares nos animais com 30 dias de gestação. Aos 60 dias, ao lado de fibras com aparência normal, observaram-se fibras com contornos mais polimórficos e outras fibras de diâmetros muito pequenos. Aos 30 dias pp, as características do tecido foram similares às dos animais em fase pré-gestacional. Em todas as fases estudadas, os diâmetros fibras tipo II foram maiores do que as do tipo I. Aos 30 dias observou-se a redução significativa dos diâmetros de ambos os tipos de fibras e aumento significativo aos 60 dias de gestação. Durante a gestação, o estímulo crônico, representado pela expansão da parede abdominal, promoveu alterações da morfologia e morfometria das fibras.

  15. Biodegradación de compuestos fenólicos del alpechín con Aspergillus terreus

    Directory of Open Access Journals (Sweden)

    García Paeja, María P.

    1992-04-01

    Full Text Available Olive mill wastewater degradation by Aspergillus terreus and under aerobic conditions at 28°C, was measured by the parameter of phenol content. We have explored the effect of different concentrations of olive mill wastewater upon the activity of Aspergillus terreus. Through HPLC, 10 phenol compounds (90% of the total phenolic content of the olive mill wastewater were identified.Se estudia la degradación de alpechines con Aspergillus terreus en condiciones de aerobiosis y temperatura de 28°C, utilizando como parámetro el contenido fenólico. Se analiza el efecto de la concentración de alpechín con Aspergillus terreus utilizando el mismo parámetro. Se han identificado por cromatografía líquida de alta eficacia (CLAE 10 compuestos fenólicos que suponen el 90% del total del alpechín.

  16. PROPIEDADES TÉCNICO-FUNCIONALES DE LA FIBRA DIETARIA DE CÁSCARAS DE MANGO VARIEDADHILACHA (Mangifera indica L.: EFECTO DEL SECADO POR CONVECCIÓN

    Directory of Open Access Journals (Sweden)

    GUSTAVO ADOLFO HINCAPIÉ LL.

    2014-06-01

    Full Text Available Un subproducto de la obtención del jugo de mango es su cáscara; la cual contiene niveles considerables de fibra dietaria que podrían ser utilizados en la elaboración de productos alimenticios, sin embargo, actualmente no es muy aprovechado. El proceso de secado prolonga la vida útil de la cascara y permite que pueda ser adicionada a otros alimentos. En este estudio, se caracterizó fisicoquímicamente la Cáscara de Mango Hilacha (CMH y se evaluó el efecto de cinco temperaturas de secado sobre las propiedades técnico-funcionales de la fibra dietaria; Capacidad de Hinchamiento (CH, Capacidad de Retención de Agua (CRA y Capacidad de Adsorción de Lípidos (CAL, características que determinan en gran medida la calidad de la fibra dietaria (FD. Los resultados obtenidos indican que la CMH tiene un contenido de fibra dietaria total, proteína, extracto etéreo, carbohidratos y fibra cruda similar al de otras variedades de mango. La cáscara de mango hilacha seca y molida (CSMH obtenida, es una promisoria fuente de FD, ya que su calidad no se vio afectada significativamente por el proceso de secado empleado en este trabajo.

  17. DETERMINACIÓN DE ÁCIDOS GRASOS Y COMPUESTOS TRITERPENOIDES DEL CUERPO FRUCTIFERO DE Suillus luteus.

    Directory of Open Access Journals (Sweden)

    Ivonne Nieto

    2009-04-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Del cuerpo fructífero de Suillus luteus se extrajeron e identificaron, con base en el análisis de sus espectros de masas,  dieciséis compuestos, los cuales corresponden al ácido palmítico, oléico, linolénico y linoléico, octadecanoato de etilo, ergosta-7,22-dien-3β-ol, ergosta-7-en-3β-ol, estigmasterol, ergosta-3,5,7,9(11,22-pentaeno, ergosta-2,5,7,9(11,14,22-hexaeno, 23-metil-estigmast-3,5,7,22-tetraeno, 23-metil-estigmast-3,5,7,9(11,22-pentaeno, ergosta-4,6,15(16,22-tetraen-3-ona,  ergosta-1,5,7,9(11,22-pentaen-3-ona, ergosta-5,7,9(11,22-tetraen-3β-ol y ergosta-5,6,7-trihidroxi-7,22-dien-3β-ol. Siendo este un hongo tan poco estudiado, todos los compuestos, a excepción de los ácidos grasos, se reportan aquí por primera vez.

  18. Volatile organic compound (VOC) determination in working atmospheres; Determinacion de compuestos organicos volatiles (VOC) en ambiente laboral

    Energy Technology Data Exchange (ETDEWEB)

    Blass A, Georgina; Panama T, Luz A; Corrales C, Deyanira [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2003-07-01

    The present work describes, in a synthesized way, the implementation and application of procedures based on the normativity related to the subject of the volatile organic compounds (Volatile Organic Compounds VOC), that allow to sample, quantify and evaluate the present contamination in the working atmosphere of a refinery due to the fugitive emissions of VOC and other substances. In accordance with the corresponding normativity, more than 189 organic compounds denominated dangerous air polluting agents (Hazardous Air Pollutants, HAP) can be found in a working atmosphere, but they are the 11 main HAP that can be found in a refinery. In the present article the work made for the sampling and quantification of 5 of the 11 dangerous polluting agents of the air: benzene, toluene, xylene, iso-octane and naphthalene. [Spanish] El presente trabajo describe, de manera sintetizada, la implementacion y aplicacion de procedimientos basados en la normatividad relacionada al tema de los compuestos organicos volatiles (Volatil Organic Compounds, VOC), que permiten muestrear, cuantificar y evaluar la contaminacion presente en el ambiente laboral de una refineria debido a las emisiones fugitivas de VOC y otras sustancias. De acuerdo con la normatividad correspondiente, mas de 189 compuestos organicos denominados contaminantes peligrosos del aire (Hazardous Air Pollutants, HAP), pueden ser encontrados en un ambiente laboral, pero son 11 los principales HAP que pueden ser hallados en una refineria. En el presente articulo se informa el trabajo realizado para el muestreo y cuantificacion de 5 de los 11 contaminantes peligrosos del aire: benceno, tolueno, xileno, iso-octano y naftaleno.

  19. Prevalence of obesity, sarcopenic obesity and associated factors: A FIBRA Network study

    Directory of Open Access Journals (Sweden)

    Carla Moura Santos

    Full Text Available Abstract Introduction: Sarcopenic obesity in older adults may lead to an inability to use muscles efficiently and has been associated with functional deficits and disabilities. Objective: To identify the prevalence of obesity and sarcopenic obesity (SO among community-dwelling older adults, and to characterize associated sociodemographics, health conditions and functional performance. Methods: Study data are from the FIBRA Network database of the Federal University of Minas Gerais. There were 1,373 older adult participants, subdivided into three groups: 1 non-obese; 2 non-sarcopenic obese; and 3 sarcopenic obese (SO. The latter is defined as a BMI ≥30 kg/m2 and weak palmar grip strength (PGS. Results: The overall prevalence of obesity and SO among older adults was 25.85% and 4.44%, respectively, with levels of frailty and pre-frailty among at 36.1% and 59%, respectively. Gait speed (GS was lower in the SO group as well, compared to the other groups. An average increase in GS of 0.1 m/sec reduced the likelihood of SO by 85.1%, in average. Sarcopenic obese older adults were 14.2 times more likely to be pre-fragile and 112.9 times more likely to be fragile than the other groups. Conclusion: The prevalence of obesity found in this study was higher than that in the general population, but similar to national statistics for the sample’s mean age and gender. SO was directly associated with frailty in advanced and instrumental activities of daily living as well as gait speed and significantly increased the likelihood of being pre-frail and frail. GS may be an extremely useful tool for monitoring the progress of SO in older adults.

  20. Postes prefabricados de fibra: Consideraciones para su uso clínico

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    Hugo Calabria Díaz

    Full Text Available En la década de los 90 los Postes Prefabricados de Fibra (PPF se introdujeron al mercado como alternativa a los sistemas metálicos o cerámicos. Hasta la fecha se mantienen en uso, modificando de manera constante sus presentaciones comerciales y estrategias de fijación. Sus cualidades mecánicas como su bajo Módulo Elástico (ME similar al dentinario, introducen un nuevo paradigma en la rehabilitación del Diente Endodonticamente Tratado (DET: .ldquo;el poste debe acompañar en forma solidaria la flexión de los tejidos dentarios frente a las cargas.rdquo;. Sus actuales cualidades estéticas, la fácil remoción y la posibilidad de su cementado adhesivo, los han convertido en una alternativa válida a las soluciones convencionales. Sin embargo, algunos resultados contradictorios junto con la importante dificultad de lograr hibridación en la dentina radicular, mantienen interrogantes a resolver en el futuro. Se indican en casos en donde se prevea retratamiento, en pacientes jóvenes, de alta exigencia estética y toda vez que se quiera y pueda eludir los costos de aleaciones nobles. En el presente artículo se analizan los fundamentos clínicos y experimentales de distintos autores, extrapolándose consideraciones prácticas para su uso. Los mismos se ilustran en un caso clínico para un paciente joven, con antecedente de traumatismo y con altas expectativas estéticas

  1. Espalhamento e secagem de filme de amido-glicerol-fibra preparado por "tape-casting"

    Directory of Open Access Journals (Sweden)

    Jaqueline Oliveira de Moraes

    2014-02-01

    Full Text Available O objetivo deste trabalho foi avaliar processos de espalhamento e secagem de filme de amido-glicerol-fibras de celulose, preparado por "tape-casting". O espalhamento da suspensão foi avaliado a 50, 150 e 250 cm min-1, seguido de secagem em estufa com circulação forçada de ar, a 40 ou 70ºC; avaliou-se também o espalhamento da suspensão a 150 cm min-1, seguido da secagem do filme sobre suporte de "tape-casting" a 22ºC e 60% de umidade relativa, com velocidades do ar de 4, 6 e 8 m s-1 no túnel de secagem. Ensaios reológicos mostraram que o espalhamento das suspensões a temperaturas inferiores a 50ºC apresentou módulo de elasticidade superior ao módulo viscoso, em todo o espectro de frequências de oscilação. As microscopias mostraram filmes secos a 40 e 70ºC sem defeitos de formação, e cujas propriedades mecânicas não diferiam. A velocidade de espalhamento e a do ar não modificam o tempo de secagem nem as propriedades dos filmes. O tempo de secagem pode ser reduzido para aproximadamente duas horas, o que é importante para a produção dos filmes em larga escala.

  2. EVALUACIÓN HISTOLÓGICA DE BIOCOMPATIBILIDAD Y BIOCONDUCCIÓN DEL COMPUESTO HIDROXIAPATITA - LIGNINA IMPLANTADO EN TIBIA DE CONEJOS

    Directory of Open Access Journals (Sweden)

    Marlene Vargas V

    2009-04-01

    Full Text Available Objetivo. Evaluar histologicamente la biocompatibilidad y propiedad óseoconductora del compuesto de hidroxiapatita - lignina implantado en tibias de conejos. Material y métodos. Se utilizaron 20 conejos de raza nueva Zelanda, en cada uno, la tibia izquierda fue tratada con el compuesto y la tibia derecha no fue tratada y sirvió como control. Con la ayuda de taladro manual y una broca se realizó un defecto óseo de aproximadamente 4 mm de diámetro en la superficie lateral proximal tibial, hasta alcanzar el canal medular. Dos comprimidos del compuesto (400 mg, se utilizaron para rellenar el defecto. El mismo procedimiento quirúrgico se realizó en el grupo control, sin la utilización del compuesto. Las evaluaciones histológicas se realizaron a los 8, 30, 60, 90 y 120 días postcirugía, para lo que fue necesaria la eutanasia de 4 animales por fecha de evaluación. Resultados. En las evaluaciones de 30, 60, 90 y 120 días se observó una formación ósea más acelerada y extensa en el grupo tratado al compararse las lecturas histológicas con el grupo control. Conclusiones. El compuesto hidroxiapatita-lignina permitió el crecimiento de tejido óseo desde los bordes hasta el centro del defecto a un ritmo de crecimiento mayor, con formación de hueso mas organizado que en el grupo control. Además se observó su integración al tejido óseo; lo que sugiere su biocompatibilidad y propiedad óseoconductora, hecho que permite recomendarlo como substituto.

  3. ANÁLISIS DEL PERFIL DE COMPUESTOS VOLÁTILES DEL MANGO (Mangifera indica L. Var. Tommy Atkins TRATADO POR MÉTODOS COMBINADOS

    Directory of Open Access Journals (Sweden)

    Angélica Moreno

    2010-09-01

    Full Text Available Se evaluó el perfil de compuestos volátiles del mango (Mangifera indica L. Var. Tommy Atkins al ser tratado con la combinación de los métodos de deshidratación osmótica con o sin pulso de vacío (DOPV y DO y con secado por aire caliente o con vacío (SAC y VAC. El tiempo utilizado en la cinética del proceso de DO fue de 42 horas y la DOPV de 30 horas; en los procesos de secado, el SAC se realizó durante 24 horas y el VAC requirió 40 horas. En el perfil de compuestos volátiles del mango fresco analizado por cromatografía de gases acoplada a detector de espectrometría de masas (GC-MS se encontraron compuestos tipo mono y sesquiterpénico, además de ácidos y ésteres grasos. El germacreno D (20,49% fue el compuesto terpénico de mayor abundancia encontrado en el análisis realizado. La cantidad de compuestos volátiles en la fruta procesada fue afectada por la aplicación de DOPV y VAC; sin embargo estas pérdidas fueron menores que en las muestras secadas sin pretratamiento osmótico. En el análisis sensorial realizado, las frutas tratadas con DOPV y DO presentaron una menor intensidad calificada en el olor en comparación con la muestra no pretratada.

  4. EVALUACIÓN QUIMICA DE LA FIBRA EN SEMILLA, PULPA Y CÁSCARA DE TRES VARIEDADES DE AGUACATE

    Directory of Open Access Journals (Sweden)

    ADELA MARÍA CEBALLOS P

    Full Text Available El sector agropecuario colombiano requiere integrarse al sector agroindustrial para aumentarle valor a sus productos y residuos. Utilizar residuos agrícolas y agroindustriales como materias primas para obtener metabolitos secundarios es tema de interés en investigación y busca dar respuestas al uso de esos residuos, mediante desarrollo de tecnologías aplicables al entorno colombiano. Se valoraron cáscara, semilla y pulpa de aguacate variedades Booth8, Trinidad y Papelillo en estados de madurez fisiológica (MF y consumo (MC. Se hizo caracterización bromatológica, contenido de fibra como carbohidratos solubles (CHOS, lignina LG, celulosa y hemicelulosa (CEL y HEMICEL y fibra bruta (FB según (Tappi Methods 1993, 1998, AOAC, 2001. Los resultados fueron analizados mediante ANOVA (P < 0,05 utilizando SAS V9.1. Los CHOS en los dos estados de madurez y para las tres variedades variaron entre 12-38% cáscara, 20-35% pulpa y 17-35% semilla; CEL y HEMICEL 8-50% cáscara, 7-26% pulpa, 1-5% semilla, los cuales pueden ser útiles como complementos de procesos biotecnológicos. La pulpa de las tres variedades tiene alto valor nutricional por sus contenidos de proteína, fibra y minerales. La composición de la cáscara y semilla podrían ser importantes para suplementos de dieta animal o como recuperador de suelos para la producción agrícola

  5. La fibra óptica y el fenómeno no lineal mezcla de cuarta onda

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    Fabián Gómez López

    2015-12-01

    Full Text Available RESUMEN Para aprovechar de mejor manera el ancho de banda que tiene la fibra óptica, los sistemas de comunicaciones ópticos han tenido que aumentar la potencia de transmisión de las señales para poder transportar a grandes distancias la información. Debido a lo anterior, comienzan a producirse ciertos fenómenos ópticos no lineales como la mezcla de cuarta onda (Four Wave Mixing, FWM, que degradan la señal de información. En este documento se realiza un estado del arte de la fibra óptica y un estudio del fenómeno no lineal FWM, que se genera cuando dos o más señales ópticas se propagan en la fibra, lo cual conlleva a una mezcla de señales que puede generar nuevos componentes de interferencia de la señal óptica transmitida. ABSTRACT To make better use of the bandwidth that has the optical fiber, optical communications systems have had to increase the transmission power of signals to transport information over long distances. Because of this, certain nonlinear optical phenomena such as four wave mixing (Four Wave Mixing, FWM, which degrade the information signal begin to occur. Herein a state of the art of optical fiber and a study of the nonlinear FWM phenomenon, which is generated when two or more optical signals propagating in the fiber takes place, which leads to a mixture of signals that can generate new components interference of the transmitted optical signal.

  6. Caracterización de morteros de yeso reforzados con fibras recuperadas de eslingas textiles de un solo uso.

    OpenAIRE

    Tasán Cruz, Dany Marcelo

    2012-01-01

    Este trabajo estudia el comportamiento de conglomerantes a base de yeso agregados con Residuos de Construcción y demolición (RCD) como fibras recuperadas de eslingas textiles de un solo uso, incorporadas en tres porcentajes y comparando con una muestra de referencia.Las eslingas textiles de un solo uso, tienen como origen, dos obras situadas en la Comunidad de Madrid (Centro de Neurociencias Ramón y Cajal) y la Comunidad de Castilla la Mancha (Nuevo Hospital de Cuenca). Han sido estudiadas...

  7. Estudo do comportamento fotofísico de prepregs de fibra de vidro e resina fenólica.

    OpenAIRE

    Rogério da Silva Rosa

    2007-01-01

    O objetivo desse trabalho é a aplicação da Espectroscopia de Luminescência em modo estacionário para o estudo do processo de cura de pré-impregnados (prepregs) de fibra de vidro e resina fenólica, tratadas termicamente em três diferentes temperaturas 90, 120 e 150 C. O processo de cura dos prepregs também foi monitorado por Espectroscopia de absorção na região do Infravermelho com transformada de Fourier (FT-IR). Os espectros de luminescência dos prepregs mostram mudanças significativas atrib...

  8. Medición de microdeformaciones en losas viales usando sensores de redes de Bragg en fibras ópticas

    OpenAIRE

    Vélez-Hoyos, Francisco Javier; Serpa-Imbet, Claudia Milena; Gómez-Cardona, Nelson Darío

    2010-01-01

    En este trabajo se presenta un método no invasivo para la medición de microdeformaciones en estructuras de concreto usando sensores de redes de Bragg en fibras ópticas adheridos a su superficie. Se realizan mediciones en losas viales de concreto bajo una carga estática de 10 kN, encontrándose una relación aproximada de 2 : 1 entre la deformación registrada por los sensores y los valores arrojados por una simulación computacional con el método de elementos finitos. Se propone el uso de estos s...

  9. Comportamiento del hormigón con áridos siderúrgicos (EAF) reforzado con fibras

    OpenAIRE

    Fuente Alonso, José Antonio de la

    2016-01-01

    La investigación que recoge la presente Tesis Doctoral desarrolla un estudio experimental para obtener hormigones destinados a pavimentos y/o soleras utilizando como áridos los residuos generados en la fabricación de acero en hornos eléctricos de arco, escoria negra EAF, y reforzándolo con fibras metálicas o sintéticas. El objetivo principal es la elaboración de un hormigón siderúrgico, utilizando escoria negra de horno eléctrico de arco EAF como sustitución de los áridos naturales en un 7...

  10. Incremento de productividad en la producción de fibras acrílicas mediante la mejora de procesos.

    OpenAIRE

    Zabarburu Chuquizuta, Segundo Jose; Zabarburu Chuquizuta, Segundo Jose; Zabarburu Chuquizuta, Segundo Jose

    2012-01-01

    Vivimos en la época de la globalización, en donde no existen fronteras económicas, con mercados altamente competitivos, los cuales obligan a las empresas a realizar innovaciones tecnológicas, mejorar sus procesos, reducir sus costos y mejorar su calidad para lograr precisamente ser más competitivos. En este sentido la empresa Sudamericana de Fibras S.A. busca optimizar sus procesos y el uso de sus recursos. El siguiente trabajo de tesis está basado en la modificación de procesos que tra...

  11. Resistência à compressão de argamassas em função da adição de fibra de coco

    OpenAIRE

    Silva,Everton J. da; Silva,Paola D. da; Marques,Maria L.; Fornari Junior,Celso C. M.; Garcia,Fermin C.; Luzardo,Francisco H. M.

    2014-01-01

    Neste trabalho se propôs analisar a influência que a variação do comprimento da fibra de coco exerce na resistência à compressão da argamassa, em busca de se determinar, experimentalmente, o comprimento mais próximo ao tamanho crítico. Foram confeccionadas argamassas com adição (0,3% em relação ao volume total da mistura) de 6 comprimentos diferentes de fibras de coco: 12,5; 25,0; 37,5; 50,0; 62,5 e 75,0 mm, além de uma argamassa de referência sem adição de fibra de coco. Para a avaliação do ...

  12. Estado del arte sobre el comportamiento físico-mecánico de la escayola reforzada con fibras de vidrio E

    Directory of Open Access Journals (Sweden)

    Comino Almenara, Pablo

    2004-10-01

    Full Text Available This article contains a discussion of the results and conclusions obtained in different studies to determine the physical and mechanical performance of fibre-reinforced plaster/scagliola specimens. The reinforcement used in this case is short filaments of fibreglass-E, the type of fibre most widely used at this time in Spain to reinforce prefabricated plaster/scagliola.En este artículo se presentan los resultados y las conclusiones obtenidas en diferentes estudios, sobre el comportamiento físico y mecánico, realizados en probetas de yeso/escayola reforzadas mediante la incorporación de fibras, y, en concreto, de fibras de vidrio E, en formato de hilos cortados. Este tipo de fibras son las más utilizadas en la actualidad para el refuerzo en prefabricados de yeso/ escayola, en España.

  13. Comportamiento mecánico y dinámico de una mezcla asfáltica con adición de fibras

    Directory of Open Access Journals (Sweden)

    Oscar Javier Reyes Ortiz

    2005-01-01

    Full Text Available El artículo refiere el análisis experimental en el laboratorio, del efecto de la adición de fibras de polipropileno por vía seca (reemplazo de material granular por fibra sobre las propiedades mecánicas y dinámicas de una mezcla. Inicialmente se caracteriza el material granular y asfalto CA60/70, se realiza el diseño de la mezcla asfáltica de granulometría 0/10 (IDU RSV 2002 y asfalto de acuerdo con la metodología Marshall; se evalúa el efecto de fibras sobre las propiedades mecánicas mediante la evaluación de la estabilidad y fluencia, y dinámicamente por su valor de deformación permanente y modulo dinámico. Los resultados muestran un efecto positivo de las fibras en la modificación de la mezcla asfáltica. El modulo dinámico aumenta en un 45% promedio en un porcentaje de adición de 0.60%; la deformación permanente disminuye en 27.6% para una adición de fibras de 0.60% y 48.8% para la adición de fibras de 0.75%, respectivamente. Este comportamiento refleja otra alternativa eficaz para mejorar la mezcla asfáltica, aumentando la resistencia a la disgregación por efecto abrasivo del tráfico y retardando el inicio y propagación del agrietamiento por ahuellamiento

  14. Fiber-optic components for optical communicatios and sensing =

    Science.gov (United States)

    Marques, Carlos Alberto Ferreira

    Nos ultimos anos, a Optoelectronica tem sido estabelecida como um campo de investigacao capaz de conduzir a novas solucoes tecnologicas. As conquistas abundantes no campo da optica e lasers, bem como em comunicacoes opticas tem sido de grande importancia e desencadearam uma serie de inovacoes. Entre o grande numero de componentes opticos existentes, os componentes baseados em fibra optica sao principalmente relevantes devido a sua simplicidade e a elevada de transporte de dados da fibra optica. Neste trabalho foi focado um destes componentes opticos: as redes de difraccao em fibra optica, as quais tem propriedades opticas de processamento unicas. Esta classe de componentes opticos e extremamente atraente para o desenvolvimento de dispositivos de comunicacoes opticas e sensores. O trabalho comecou com uma analise teorica aplicada a redes em fibra e foram focados os metodos de fabricacao de redes em fibra mais utilizados. A inscricao de redes em fibra tambem foi abordado neste trabalho, onde um sistema de inscricao automatizada foi implementada para a fibra optica de silica, e os resultados experimentais mostraram uma boa aproximacao ao estudo de simulacao. Tambem foi desenvolvido um sistema de inscricao de redes de Bragg em fibra optica de plastico. Foi apresentado um estudo detalhado da modulacao acustico-optica em redes em fibra optica de silica e de plastico. Por meio de uma analise detalhada dos modos de excitacao mecanica aplicadas ao modulador acustico-optico, destacou-se que dois modos predominantes de excitacao acustica pode ser estabelecidos na fibra optica, dependendo da frequencia acustica aplicada. Atraves dessa caracterizacao, foi possivel desenvolver novas aplicacoes para comunicacoes opticas. Estudos e implementacao de diferentes dispositivos baseados em redes em fibra foram realizados, usando o efeito acustico-optico e o processo de regeneracao em fibra optica para varias aplicacoes tais como rapido multiplexador optico add-drop, atraso de grupo

  15. Elaboración de salchichas de pollo bajas en grasa y ricas en omega-3 y fibra

    OpenAIRE

    CARDA NAVARRO, CARLOS

    2014-01-01

    [ES] La industria cárnica constituye uno de los sectores de más importancia en la industria alimentaria, la cual destaca por su fortaleza ante la difícil situación económica. El objetivo del presente trabajo es la formulación de un producto cárnico, en concreto, de salchichas cocidas a base de pollo con diferentes compuestos de origen vegetal con una elevada calidad nutricional. El trabajo se realiza teniendo en cuenta la necesidad que existe en el mercado de productos cárnicos...

  16. Unexpected exacerbations following initiation of disease-modifying drugs in neuromyelitis optica spectrum disorder: Which factor is responsible, anti-aquaporin 4 antibodies, B cells, Th1 cells, Th2 cells, Th17 cells, or others?

    Science.gov (United States)

    Kira, Jun-Ichi

    2017-08-01

    Some disease-modifying drugs for multiple sclerosis, which mainly act on T cells, are ineffective for neuromyelitis optica spectrum disorder and induce unexpected relapses. These include interferon beta, glatiramer acetate, fingolimod, natalizumab, and alemtuzumab. The cases reported here suggest that dimethyl fumarate, which reduces the number of Th1 and Th17 cells and induces IL-4-producing Th2 cells, is also unsuitable for neuromyelitis optica spectrum disorder, irrespective of anti-aquaporin 4 IgG serostatus. Although oral dimethyl fumarate with manageable adverse effects is easy to initiate in the early course of multiple sclerosis, special attention should be paid for atypical demyelinating cases.

  17. Produção de biscoitos extrusados de polvilho azedo com fibras: efeito de parâmetros operacionais sobre as propriedades físicas

    OpenAIRE

    Camargo,Karina Fernandes de; Leonel,Magali; Mischan,Martha Maria

    2008-01-01

    Neste trabalho buscou-se avaliar o efeito de parâmetros operacionais do processo de extrusão no desenvolvimento de biscoitos de polvilho com fibras, utilizando como matérias-primas o polvilho azedo e o farelo de mandioca. O processamento foi realizado em um extrusor mono-rosca, sendo considerados parâmetros variáveis: temperatura na 3ª zona de extrusão, umidade e porcentagem de fibras na mistura. Para analisar o efeito combinado das variáveis independentes nas características tecnológicas dos...

  18. Consumo de fibra dietética en lactantes menores de 2 años y estreñimiento funcional

    OpenAIRE

    Velasco Benítez, Carlos Alberto; Giraldo Lora, Sandra Carolina

    2015-01-01

    Antecedentes. La inclusión de la fibra dietética (FD), tiene múltiples beneficios sobre la salud del ser humano; sin embargo, en pediatría, existen grandes brechas concernientes a la relación de fibra y estreñimiento. Objetivo. Describir el hábito intestinal en lactantes . Se tuvo en cuenta la alimentación con leche materna, el tiempo de inicio de alimentación complementaria y el antecedente de madre o cuidador con EF. Los resultados son expresados como promedio ± desviación estándar. El anál...

  19. Elaboración y caracterización estructural de fibras de tereftalato de polietileno (PET) dopadas con nanocobre (0) utilizando proceso de extrusión

    OpenAIRE

    Guzman, A.; Cárcamo, H.; León, O.

    2015-01-01

    El presente estudio describe la elaboración y caracterización de una fibra sintética bactericida compuesta por Tereftalato de Polietileno reciclado (rPET) y nanopartículas de cobre (0), mediante un proceso de extrusión utilizando una extrusora monohusillo. Las nanopartículas empleadas fueron elaboradas utilizando radiación microondas y ultrasonido. Para la elaboración de la fibra se produce un masterbatch de rPET con polvo de cobre nanométrico empleando un solvente de alto punto de fusión (tr...

  20. Metodología para el diseño óptimo de dovelas de hormigón reforzado con fibras

    OpenAIRE

    Fuente Antequera, Albert de la; Pujadas Álvarez, Pablo; Blanco Álvarez, Ana; Aguado de Cea, Antonio

    2012-01-01

    En este trabajo se presentan una de las experiencias más relevantes relativas al uso de fibras estructurales como refuerzo del hormigón substitución prácticamente toda la armadura pasiva tradicional en dovelas para anillos de revestimiento en el área metropolitana de Barcelona. Es conocido, que la adición de fibras estructurales mejora, por una parte, la respuesta estructural del elemento durante su construcción, especialmente durante la acción del empuje de los gatos, y, por otra parte, cond...

  1. Sintesis in situ de nanopartículas de peróxido de zinc sobre fibras de plátano con potencial en la industria textil

    OpenAIRE

    María Estefanía Ballesteros García; John Ricardo Jr. Duran Romero; Juliana Gutiérrez Corrales; Alis Pataquiva-Mateus

    2017-01-01

    El presente trabajo de investigación plantea un desarrollo entorno al manejo de residuos en los cultivos de plátano, siendo una idea sostenible con respecto a la extracción y adquisición de fibras con cualidades innovadoras que posean nanopartículas (NPs) de ZnO2 como la capacidad antimicrobiana. La finalidad de la investigación fue la de nanoestructurar fibras provenientes de residuos del plátano con NPs de peróxido de zinc como una propuesta sostenible, teniendo en cuenta factores de optimi...

  2. Construção e caracterização de um amplificador em fibra para pulsos ultracurtos em ʎ = 1.5 um

    OpenAIRE

    ARIAS, Luis Alfredo Giraldo

    2014-01-01

    Lasers de pulsos ultracurtos baseados em fibras ópticas como meio de ganho constituem fortes candidatos para substituir lasers de estado sólido mais tradicionais, tais como o laser de Ti:safira. Uma das razões é o custo direto e outra é a possibilidade de compactação de sistemas que ocupam muito espaço e consomem quantidades significativas de energia. Um dos problemas de lasers baseados em fibras ópticas é que a potência óptica média disponível é relativamente baixa, da ordem d...

  3. Estudo da flamabilidade e resistência à chama de compósito de poliéster insaturado e fibra da folha do abacaxizeiro (PALF)

    OpenAIRE

    Ribeiro, Luciene Mendes

    2011-01-01

    Na presente pesquisa foram desenvolvidos compósitos com fibras da folha do abacaxizeiro (PALF - Pineapple Leaf Fiber), utilizando resina de poliéster insaturado como matriz, incorporando retardante de chama em diferentes composições. As fibras da folha do abacaxizeiro foram obtidas na ramada 4 do município de Ielmo Marinho no Estado do Rio Grande do Norte. A resina de poliéster insaturado e o catalisador foram comprados no comércio. O retardante de chama de alumina trihidratada (hidróxido de ...

  4. Contribución al desarrollo de sensores de temperatura y redes de sensores en tecnología de fibra óptica

    OpenAIRE

    Madruga Saavedra, Francisco Javier

    2006-01-01

    Este trabajo de tesis recoge las contribuciones aportadas en el campo de los sensores de fibra óptica en tres ámbitos de trabajo. Un sistema sensor de alta temperatura sin contacto con transductores de fibras ópticas de sílice se ha presentado. Dos topologías de "ojo abierto" y "ojo cerrado" y un algoritmo de decodificación "pirometría de banda dual" propuesto en este trabajo son las novedosas aportaciones presentadas. El sistema ha sido validado en laboratorio y en pruebas de campo de forma ...

  5. Contribución al desarrollo de sensores de temperatura y redes de sensores en tecnología de fibra óptica

    OpenAIRE

    Madruga Saavedra, Francisco Javier

    2008-01-01

    RESUMEN: Este trabajo de tesis recoge las contribuciones aportadas en el campo de los sensores de fibra óptica en tres ámbitos de trabajo. Un sistema sensor de alta temperatura sin contacto con transductores de fibras ópticas de sílice se ha presentado. Dos topologías de "ojo abierto" y "ojo cerrado" y un algoritmo de decodificación "pirometría de banda dual" propuesto en este trabajo son las novedosas aportaciones presentadas. El sistema ha sido validado en laboratorio y en pruebas de campo ...

  6. Frequency of brain MRI abnormalities in neuromyelitis optica spectrum disorder at presentation: A cohort of Latin American patients.

    Science.gov (United States)

    Carnero Contentti, Edgar; Daccach Marques, Vanessa; Soto de Castillo, Ibis; Tkachuk, Veronica; Antunes Barreira, Amilton; Armas, Elizabeth; Chiganer, Edson; de Aquino Cruz, Camila; Di Pace, José Luis; Hryb, Javier Pablo; Lavigne Moreira, Carolina; Lessa, Carmen; Molina, Omaira; Perassolo, Monica; Soto, Arnoldo; Caride, Alejandro

    2018-01-01

    Brain magnetic resonance imaging (BMRI) lesions were classically not reported in neuromyelitis optica (NMO). However, BMRI lesions are not uncommon in NMO spectrum disorder (NMOSD) patients. To report BMRI characteristic abnormalities (location and configuration) in NMOSD patients at presentation. Medical records and BMRI characteristics of 79 patients with NMOSD (during the first documented attack) in Argentina, Brazil and Venezuela were reviewed retrospectively. BMRI abnormalities were observed in 81.02% of NMOSD patients at presentation. Forty-two patients (53.1%) showed typical-NMOSD abnormalities. We found BMRI abnormalities at presentation in the brainstem/cerebellum (n = 26; 32.9%), optic chiasm (n = 16; 20.2%), area postrema (n = 13; 16.4%), thalamus/hypothalamus (n = 11; 13.9%), corpus callosum (n = 11; 13.9%), periependymal-third ventricle (n = 9; 11.3%), corticospinal tract (n = 7; 8.8%), hemispheric white matter (n = 1; 1.2%) and nonspecific areas (n = 49; 62.03%). Asymptomatic BMRI lesions were more common. The frequency of brain MRI abnormalities did not differ between patients who were positive and negative for aquaporin 4 antibodies at presentation. Typical brain MRI abnormalities are frequent in NMOSD at disease onset. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Efficacy of Polyvalent Human Immunoglobulins in an Animal Model of Neuromyelitis Optica Evoked by Intrathecal Anti-Aquaporin 4 Antibodies

    Directory of Open Access Journals (Sweden)

    Benedikt Grünewald

    2016-08-01

    Full Text Available Neuromyelitis Optica Spectrum Disorders (NMOSD are associated with autoantibodies (ABs targeting the astrocytic aquaporin-4 water channels (AQP4-ABs. These ABs have a direct pathogenic role by initiating a variety of immunological and inflammatory processes in the course of disease. In a recently-established animal model, chronic intrathecal passive-transfer of immunoglobulin G from NMOSD patients (NMO-IgG, or of recombinant human AQP4-ABs (rAB-AQP4, provided evidence for complementary and immune-cell independent effects of AQP4-ABs. Utilizing this animal model, we here tested the effects of systemically and intrathecally applied pooled human immunoglobulins (IVIg using a preventive and a therapeutic paradigm. In NMO-IgG animals, prophylactic application of systemic IVIg led to a reduced median disease score of 2.4 on a 0–10 scale, in comparison to 4.1 with sham treatment. Therapeutic IVIg, applied systemically after the 10th intrathecal NMO-IgG injection, significantly reduced the disease score by 0.8. Intrathecal IVIg application induced a beneficial effect in animals with NMO-IgG (median score IVIg 1.6 vs. sham 3.7 or with rAB-AQP4 (median score IVIg 2.0 vs. sham 3.7. We here provide evidence that treatment with IVIg ameliorates disease symptoms in this passive-transfer model, in analogy to former studies investigating passive-transfer animal models of other antibody-mediated disorders.

  8. The cervical spinal cord in neuromyelitis optica patients: A comparative study with multiple sclerosis using diffusion tensor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pessôa, Fernanda Miraldi Clemente, E-mail: fernandamiraldi@hotmail.com [Federal University of Rio de Janeiro, Medical Student, Rua Rodolpho Paulo Rocco, 255, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ (Brazil); Lopes, Fernanda Cristina Rueda, E-mail: frueda81@hotmail.com [Department of Radiology, Federal University of Rio de Janeiro, Avenida das Américas, 4666 sl 325, Barra da Tijuca, Rio de Janeiro, RJ (Brazil); Costa, João Victor Altamiro, E-mail: victoraltamiro@gmail.com [Department of Radiology, Federal University of Rio de Janeiro, Rua Rodolpho Paulo Rocco, 255, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ (Brazil); Leon, Soniza Vieira Alves, E-mail: sonizavleon@globo.com [Department of Neurology, Federal University of Rio de Janeiro, Rua Rodolpho Paulo Rocco, 255, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ (Brazil); Domingues, Romeu Côrtes, E-mail: romeu@CDPi.com.br [CDPI – Clínica de Diagnóstico Por Imagem, Avenida das Américas, 4666 sl 325, Barra da Tijuca, Rio de Janeiro, RJ (Brazil); Gasparetto, Emerson Leandro, E-mail: egasparetto@gmail.com [Department of Radiology, Federal University of Rio de Janeiro, Avenida das Américas, 4666 sl 325, Barra da Tijuca, Rio de Janeiro, RJ (Brazil); CDPI – Clínica de Diagnóstico Por Imagem, Avenida das Américas, 4666 sl 325, Barra da Tijuca, Rio de Janeiro, RJ (Brazil)

    2012-10-15

    Introduction: This study aims to evaluate “in vivo” the integrity of the normal-appearing spinal cord in patients with neuromyelitis optica (NMO), using diffusion tensor MR imaging, comparing to controls and patients with multiple sclerosis (MS). Materials and methods: We studied 8 patients with NMO and 17 without any neurologic disorder. Also, 32 MS patients were selected. Fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity (MD) were calculated within regions of interest at C2 and C7 levels in the four columns of the spinal cord. Results: At C2, the FA value was decreased in NMO patients compared to MS and controls in the anterior column. Also in this column, RD value showed increase in NMO compared to MS and to controls. The FA value of the posterior column was decreased in NMO in comparison to controls. At C7, AD value was higher in NMO than in MS in the right column. At the same column, MD values were increased in NMO compared to MS and to controls. Conclusions: There is extensive NASC damage in NMO patients, including peripheral areas of the cervical spinal cord, affecting the white matter, mainly caused by demyelination. This suggests a new spinal cord lesion pattern in NMO in comparison to MS.

  9. MR imaging findings of the corpus callosum region in the differentiation between multiple sclerosis and neuromyelitis optica

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhiye, E-mail: yyqf@hotmail.com [Department of Radiology, PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China); Feng, Feng, E-mail: cjr.fengfeng@vip.163.com [Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 1 Shuaifuyuan, Wangfujing, Beijing 100730 (China); Yang, Yang, E-mail: whitean0584@sina.com.cn [Department of Neurology, PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China); Li, Jinfeng, E-mail: lijf_301@163.com [Department of Radiology, PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China); Ma, Lin, E-mail: cjr.malin@vip.163.com [Department of Radiology, PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China)

    2012-11-15

    Purpose: To evaluate MR imaging findings in corpus callosum region for the discrimination between opticospinal multiple sclerosis (OSMS) and neuromyelitis optica (NMO). Materials and methods: Forty-two definite OSMS with seronegative NMO-IgG and 23 NMO with seropositive NMO-IgG, and 27 age-matched normal controls (NC) were recruited. Sagittal T2-FLAIR images with 2-mm slice thickness were obtained. Subcallosal dot-dash (SCDD) sign and subcallosal striations (SCS) sign were reviewed. Results: SCDD was more commonly detected in OSMS (28 of 42 patients) than in NMO (5 of 23 patients) (P < 0.05). SCS showed no difference between OSMS (31 of 42 patients) and NMO (12 of 23 patients) (P > 0.05). For comparing ROC analysis among SCDD, SCS, and SCDD + SCS for predicted probability through binary logistic regression analysis, SCDD + SCS had the largest area under ROC curve (0.777) than SCDD (0.725) and SCS (0.608). Conclusion: SCDD may be helpful in distinguishing OSMS from NMO. The regression equation may also be a simple and effective method of choice for the differentiation between OSMS and NMO.

  10. Patient with neuromyelitis optica and inflammatory demyelinating lesions comprising whole spinal cord from C2 level till conus: case report

    Directory of Open Access Journals (Sweden)

    Pavlisa Goran

    2009-10-01

    Full Text Available Abstract Background Neuromyelitis optica (NMO is an idiopathic, severe, inflammatory demyelinating disease of the central nervous system, that causes severe optic neuritis and myelitis attacks. Early discrimination between multiple sclerosis (MS and NMO is important, as optimum treatment for both diseases may differ considerably. Case Presentation We report a case of a patient who initially presented as longitudinally extensive transverse myelitis (LETM, having spastic upper extremities diparesis and spastic paraplegia, C2/C3 sensory level and urinary incontinence, as well as extensive inflammatory spinal cord lesions from C2 level to conus. After 5 months the patient had another attack of transverse myelitis, had electrophysiological findings consistent with optic neuritis, was seropositive for NMO-IgG (aquaporin-4 IgG and thus fulfilled NMO diagnostic criteria. Following treatment of disease attacks with pulse corticosteroid therapy and intravenous immunoglobulins, we included oral azathioprine in a combination with oral prednisone in the therapy. Since there was no significant clinical improvement, we decided to use cyclophosphamide therapy, which resulted in good clinical improvement and gradual decrease of cord swelling. Conclusion In this NMO case report we wanted to emphasize the extensiveness of inflammatory spinal cord changes in our patient, from C2 level to conus. In the conclusion it is important to say that accurate, early diagnosis and distinction from MS is critical to facilitate initiation of immunosuppressive therapy for attack prevention.

  11. Sjögren syndrome and neuromyelitis optica spectrum disorder co-exist in a common autoimmune milieu

    Directory of Open Access Journals (Sweden)

    Diogo C. Carvalho

    2014-06-01

    Full Text Available The relationship between Sjögren’s syndrome (SS and neuromyelitis optica spectrum disorder (NMOSD is not completely understood. We report two patients with both conditions and review 47 other previously reported cases meeting currently accepted diagnostic criteria, from 17 articles extracted from PubMed. Out of 44 patients whose gender was informed, 42 were females. Mean age at onset of neurological manifestation was 36.2 years (10-74. Serum anti-AQP4-IgG was positive in 32 patients, borderline in 1, and negative in 4. Our Case 1 was seronegative for AQP4-IgG and had no non-organ-specific autoantibodies other than anti-SSB antibodies. Our Case 2 had serum anti-AQP4, anti-SSA/SSB, anti-thyreoglobulin and anti-acethylcholine-receptor antibodies, as well as clinical hypothyreoidism, but no evidence of myasthenia gravis. Our Cases and others, as previously reported in literature, with similar heterogeneous autoimmune response to aquaporin-4, suggest that SS and NMO co-exist in a common autoimmune milieu which is not dependent on aquaporin-4 autoimmunity.

  12. Linear lesions may assist early diagnosis of neuromyelitis optica and longitudinally extensive transverse myelitis, two subtypes of NMOSD.

    Science.gov (United States)

    Cai, Wei; Tan, Sha; Zhang, Lei; Shan, Yilong; Wang, Yanqiang; Lin, Yinyao; Zhou, Fangjing; Zhang, Bingjun; Chen, Xiaoyu; Zhou, Li; Wang, Yuge; Huang, Xuehong; Men, Xuejiao; Li, Haiyan; Qiu, Wei; Hu, Xueqiang; Lu, Zhengqi

    2016-01-15

    To investigate the relationship between linear lesions (LL) and the development of longitudinally extensive spinal cord lesions (LESCL) in Chinese patients with neuromyelitis optica or longitudinally extensive transverse myelitis. The clinical records of 143 patients with these conditions were reviewed. Forty-one patients with LL were divided into three groups according to the order of appearance of LL and LESCL (simultaneously [n=10], LL first [n=26], or LESCL first [n=5]). The remaining 102 patients without LL were used as a control group. Patients who developed LL first demonstrated a lower annualized relapse rate than those in the simultaneous group (1.00 [0.23-10.00] vs. 4.38 [0.60-6.67], p=0.017) and the control group (1.00 [0.23-10.00] vs. 2.00 [0.24-10.00], p=0.007). Among all patients with LL, there were significantly more who developed them before LESCL than those who developed them after LESCL (poptica and longitudinally extensive transverse myelitis. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Experimental mouse model of optic neuritis with inflammatory demyelination produced by passive transfer of neuromyelitis optica-immunoglobulin G

    Science.gov (United States)

    2014-01-01

    Background Although optic neuritis (ON) is a defining feature of neuromyelitis optica (NMO), appropriate animal models of NMO ON are lacking. Most NMO patients are seropositive for immunoglobulin G autoantibodies (NMO-IgG) against the astrocyte water channel aquaporin-4 (AQP4). Methods Several approaches were tested to develop a robust, passive-transfer mouse model of NMO ON, including NMO-IgG and complement delivery by: (i) retrobulbar infusion; (ii) intravitreal injection; (iii) a single intracranial injection near the optic chiasm; and (iv) 3-days continuous intracranial infusion near the optic chiasm. Results Little ON or retinal pathology was seen using approaches (i) to (iii). Using approach (iv), however, optic nerves showed characteristic NMO pathology, with loss of AQP4 and glial fibrillary acidic protein immunoreactivity, granulocyte and macrophage infiltration, deposition of activated complement, demyelination and axonal injury. Even more extensive pathology was created in mice lacking complement inhibitor protein CD59, or using a genetically modified NMO-IgG with enhanced complement effector function, including significant loss of retinal ganglion cells. In control studies, optic nerve pathology was absent in treated AQP4-deficient mice, or in wild-type mice receiving control (non-NMO) IgG and complement. Conclusion Passive transfer of NMO-IgG and complement by continuous infusion near the optic chiasm in mice is sufficient to produce ON with characteristic NMO pathology. The mouse model of NMO ON should be useful in further studies of NMO pathogenesis mechanisms and therapeutics. PMID:24468108

  14. MOG-IgG-Associated Optic Neuritis, Encephalitis, and Myelitis: Lessons Learned From Neuromyelitis Optica Spectrum Disorder

    Science.gov (United States)

    dos Passos, Giordani Rodrigues; Oliveira, Luana Michelli; da Costa, Bruna Klein; Apostolos-Pereira, Samira Luisa; Callegaro, Dagoberto; Fujihara, Kazuo; Sato, Douglas Kazutoshi

    2018-01-01

    Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) have been found in some cases diagnosed as seronegative neuromyelitis optica spectrum disorder (NMOSD). MOG-IgG allowed the identification of a subgroup with a clinical course distinct from that of NMOSD patients who are seropositive for aquaporin-4-IgG antibodies. MOG-IgG is associated with a wider clinical phenotype, not limited to NMOSD, with the majority of cases presenting with optic neuritis (ON), encephalitis with brain demyelinating lesions, and/or myelitis. Therefore, we propose the term MOG-IgG-associated Optic Neuritis, Encephalitis, and Myelitis (MONEM). Depending on the clinical characteristics, these patients may currently be diagnosed with NMOSD, acute disseminated encephalomyelitis, pediatric multiple sclerosis, transverse myelitis, or ON. With specific cell-based assays, MOG-IgG is emerging as a potential biomarker of inflammatory disorders of the central nervous system. We review the growing body of evidence on MONEM, focusing on its clinical aspects. PMID:29670575

  15. Eleven episodes of recurrent optic neuritis of the same eye for 22 years eventually diagnosed as neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Yew, Yih Chian; Hor, Jyh Yung; Lim, Thien Thien; Kanesalingam, Ruban; Ching, Yee Ming; Arip, Masita; Easaw, P E Samuel; Eow, Gaik Bee

    2016-11-01

    It is difficult to predict whether a particular attack of neuromyelitis optica spectrum disorder (NMOSD) will affect the optic nerve [optic neuritis (ON): unilateral or bilateral], spinal cord (myelitis), brain or brainstem, or a combination of the above. We report an interesting case of recurrent ON of the same eye for a total of 11 episodes in a Chinese woman. Over a period of 22 years, the attacks only involved the left eye, and never the right eye and also no myelitis. For a prolonged duration, she was diagnosed as recurrent idiopathic ON. Only until she was tested positive for aquaporin 4 antibody that her diagnosis was revised to NMOSD. Optical coherence tomography revealed thinning of the retinal nerve fibre layer (RNFL) for the affected left eye, while the RNFL thickness was within normal range for the unaffected right eye. The disability accrual in NMOSD is generally considered to be attack-related - without a clinical attack of ON, there shall be no visual impairment, and no significant subclinical thinning of RNFL. Our case is in agreement with this notion. This is in contrast to multiple sclerosis where subclinical RNFL thinning does occur. This case highlights the importance of revisiting and questioning a diagnosis of recurrent idiopathic ON particularly when new diagnostic tools are available. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. MR imaging findings of the corpus callosum region in the differentiation between multiple sclerosis and neuromyelitis optica

    International Nuclear Information System (INIS)

    Chen, Zhiye; Feng, Feng; Yang, Yang; Li, Jinfeng; Ma, Lin

    2012-01-01

    Purpose: To evaluate MR imaging findings in corpus callosum region for the discrimination between opticospinal multiple sclerosis (OSMS) and neuromyelitis optica (NMO). Materials and methods: Forty-two definite OSMS with seronegative NMO-IgG and 23 NMO with seropositive NMO-IgG, and 27 age-matched normal controls (NC) were recruited. Sagittal T2-FLAIR images with 2-mm slice thickness were obtained. Subcallosal dot-dash (SCDD) sign and subcallosal striations (SCS) sign were reviewed. Results: SCDD was more commonly detected in OSMS (28 of 42 patients) than in NMO (5 of 23 patients) (P 0.05). For comparing ROC analysis among SCDD, SCS, and SCDD + SCS for predicted probability through binary logistic regression analysis, SCDD + SCS had the largest area under ROC curve (0.777) than SCDD (0.725) and SCS (0.608). Conclusion: SCDD may be helpful in distinguishing OSMS from NMO. The regression equation may also be a simple and effective method of choice for the differentiation between OSMS and NMO.

  17. Spinal cord lesions in patients with neuromyelitis optica: a retrospective long-term MRI follow-up study

    Energy Technology Data Exchange (ETDEWEB)

    Krampla, Wolfgang; Hruby, Walter [SMZ-Ost Donauspital, Department of Radiology, Vienna (Austria); Aboul-Enein, Fahmy; Jecel, Julia; Kristoferitsch, Wolfgang [SMZ-Ost Donauspital, Department of Neurology, Vienna (Austria); Lang, Wilfried [Hospital of Barmherzige Brueder, Department of Neurology, Vienna (Austria); Fertl, Elisabeth [Krankenanstalt Rudolfstiftung, Department of Neurology, Vienna (Austria)

    2009-10-15

    Neuromyelitis optica (NMO) is characterised by a particular pattern of the optic nerves and the spinal cord. Long-term MRI follow-up studies of spinal NMO lesions are rare, or limited by short observation periods. In nine patients with definite NMO or recurrent longitudinally extensive transverse myelitis (LETM) with NMO-IgG serum antibodies, repeated MRI examinations of the spine were carried out over a period of up to 11 years and evaluated regarding the changes over time in this retrospective study. In eight patients spinal cord lesions were located centrally, involving the grey and white matter. In the first examination after clinical onset changes resembled a stroke of the anterior spinal artery in two patients. Symmetrical signal alterations within the grey matter were observed. In one patient this pattern was transient, but it remained in the other. During the chronic stage, either a variable degree of spinal cord atrophy and high signal alterations, or almost complete remission of the lesions, was observed. Spinal MRI of patients with NMO myelitis can resemble a stroke. MRI of acute NMO stages did not allow a prediction of the clinical outcome. To a variable degree, NMO left behind typical defects which correlated with the clinical outcome. (orig.)

  18. The cervical spinal cord in neuromyelitis optica patients: A comparative study with multiple sclerosis using diffusion tensor imaging

    International Nuclear Information System (INIS)

    Pessôa, Fernanda Miraldi Clemente; Lopes, Fernanda Cristina Rueda; Costa, João Victor Altamiro; Leon, Soniza Vieira Alves; Domingues, Romeu Côrtes; Gasparetto, Emerson Leandro

    2012-01-01

    Introduction: This study aims to evaluate “in vivo” the integrity of the normal-appearing spinal cord in patients with neuromyelitis optica (NMO), using diffusion tensor MR imaging, comparing to controls and patients with multiple sclerosis (MS). Materials and methods: We studied 8 patients with NMO and 17 without any neurologic disorder. Also, 32 MS patients were selected. Fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity (MD) were calculated within regions of interest at C2 and C7 levels in the four columns of the spinal cord. Results: At C2, the FA value was decreased in NMO patients compared to MS and controls in the anterior column. Also in this column, RD value showed increase in NMO compared to MS and to controls. The FA value of the posterior column was decreased in NMO in comparison to controls. At C7, AD value was higher in NMO than in MS in the right column. At the same column, MD values were increased in NMO compared to MS and to controls. Conclusions: There is extensive NASC damage in NMO patients, including peripheral areas of the cervical spinal cord, affecting the white matter, mainly caused by demyelination. This suggests a new spinal cord lesion pattern in NMO in comparison to MS

  19. Spinal cord lesions in patients with neuromyelitis optica: a retrospective long-term MRI follow-up study

    International Nuclear Information System (INIS)

    Krampla, Wolfgang; Hruby, Walter; Aboul-Enein, Fahmy; Jecel, Julia; Kristoferitsch, Wolfgang; Lang, Wilfried; Fertl, Elisabeth

    2009-01-01

    Neuromyelitis optica (NMO) is characterised by a particular pattern of the optic nerves and the spinal cord. Long-term MRI follow-up studies of spinal NMO lesions are rare, or limited by short observation periods. In nine patients with definite NMO or recurrent longitudinally extensive transverse myelitis (LETM) with NMO-IgG serum antibodies, repeated MRI examinations of the spine were carried out over a period of up to 11 years and evaluated regarding the changes over time in this retrospective study. In eight patients spinal cord lesions were located centrally, involving the grey and white matter. In the first examination after clinical onset changes resembled a stroke of the anterior spinal artery in two patients. Symmetrical signal alterations within the grey matter were observed. In one patient this pattern was transient, but it remained in the other. During the chronic stage, either a variable degree of spinal cord atrophy and high signal alterations, or almost complete remission of the lesions, was observed. Spinal MRI of patients with NMO myelitis can resemble a stroke. MRI of acute NMO stages did not allow a prediction of the clinical outcome. To a variable degree, NMO left behind typical defects which correlated with the clinical outcome. (orig.)

  20. Fibras vegetais utilizadas na pesca artesanal na microrregião do Salgado, Pará

    Directory of Open Access Journals (Sweden)

    Jorge Oliveira

    Full Text Available As espécies vegetais fibrosas ocupam papel de destaque no cotidiano das comunidades tradicionais amazônicas ao lado das espécies medicinais, alimentícias e madeireiras. Na microrregião do Salgado do estado do Pará - constituída pelos municípios de Colares, Curuçá, Magalhães Barata, Maracanã, Marapanim, Salinópolis, Santarém Novo, São Caetano de Odivelas, São João de Pirabas e Vigia - as fibras vegetais são usadas em cestaria, trançados, fixadoras em substituição ao prego, adornos e vestuário. Para a elaboração do presente trabalho, os dados foram obtidos entre artesãos e pescadores artesanais da microrregião do Salgado do estado do Pará, com cerca de 150 entrevistas semiestruturadas. Foram registradas 17 espécies, distribuídas em oito famílias e 17 gêneros utilizados na preparação de implementos de pesca artesanal, cujas matérias prima são provenientes de diversas partes da planta, onde as talas são da haste caulinar de Marantaceae e estipe de Arecaceae, os cipós são raízes de Araceae e Cyclanthaceae e os caules de Bignoniaceae e Dilleniaceae, enquanto que as palhas são folhas e pinas de Arecaceae. A família mais representativa com relação ao número de espécies e o fornecimento de matéria prima utilizada foi Arecaceae com 8 spp., seguida de Dilleniaceae e Araceae com 2 spp., Bignoniaceae, Bombacaceae, Cyclanthaceae, Marantaceae e Poaceae com 1 sp. cada. O trabalho visa contribuir para o conhecimento das espécies vegetais fibrosas, quanto a sua morfologia, origem e manuseio da matéria prima, os produtos confeccionados e seus usos, além do registro dos aspectos culturais da utilização de espécies vegetais fibrosas no cotidiano da atividade pesqueira artesanal daquela microrregião.

  1. Hardware reconfigurable para la reconstrucción de videos transmitidos por un mazo de fibras incoherente

    Directory of Open Access Journals (Sweden)

    Pablo Montejo Valdés

    2013-04-01

    Full Text Available La transmisión de imágenes mediante mazos de fibras ópticas no coherentes (IOFB necesita información sobre la posición de cada fibra para ser usada en la reconstrucción de la imagen original. Otro importante requerimiento es poseer suficiente memoria para almacenar la imagen durante su reconstrucción y durante su retransmisión. La mayoría de las veces estos aspectos obligan el uso de memoria externa si se utilizan FPGAs en el sistema. Este trabajo presenta una solución a este problema. Se propone un sistema en un chip capaz de almacenar la información necesaria y las imágenes sobre las que se está trabajando usando un FPGA de bajo costo. Se presentan dos soluciones y se implementa la que resulta más ventajosa. Los resultados son discutidos. El uso de este método hace posible transmitir  video usando IOFB y reconstruir las imágenes originales casi en tiempo real, debido a su baja latencia. Esta propuesta podría utilizarse en sistemas autónomos sacando ventaja de su nivel de compactación, fiabilidad y bajo costo.

  2. Poliolefinas reforçadas com fibras vegetais curtas: sisal × curauá Polyolefins reinforced with short vegetal fibers: sisal vs. curauá

    Directory of Open Access Journals (Sweden)

    Márcia A. S. Spinacé

    2011-01-01

    Full Text Available É crescente o interesse nos compósitos poliméricos reforçados com fibras vegetais curtas em substituição às fibras de vidro, pois as fibras naturais provêm de fontes renováveis, não são abrasivas aos equipamentos de processamento, são biodegradáveis, e possuem baixa densidade comparada às fibras de vidro. Elas apresentam início de degradação em torno de 200 °C, sendo adequadas para reforçar poliolefinas que são processadas até essa temperatura ou termofíxos. Várias fibras vegetais vêm sendo usadas como reforço, dentre elas o curauá e o sisal; no entanto, há grande controvérsia na literatura sobre as propriedades finais dos compósitos. Neste trabalho comparamos as propriedades de compósitos de polietileno de alta densidade ou polipropileno com 20% em massa de fibras curtas de sisal ou de curauá com ou sem agentes de acoplagem. Todos foram processados por extrusão e moldados por injeção, exatamente nas mesmas condições, e os resultados foram comparados em termos das propriedades mecânicas. As fibras de curauá apresentam resistência à tração superior às fibras de sisal e os compósitos com fibras de curauá apresentaram resistência à tração e flexão ligeiramente superior aos compósitos com fibra de sisal. No caso da resistência ao impacto a situação se inverte. Como o sisal é mais frágil que o curauá, durante o processamento ocorre maior quebra da fibra provocando essa diferenciação nas propriedades mecânicas dos compósitos.There is growing interest in reinforced polymer composites using short vegetal fibers to replace glass fibers for several reasons. The composite fibers are produced from renewable resources, being biodegradable and less abrasive to the processing equipment, in addition to possessing a lower density than the glass fibers. Since their thermal degradation onset is at 200 °C, they can be used to reinforce thermoplastics processed below this temperature and thermosets

  3. Mapa de preferência de sorvetes ricos em fibras Preference map of high-fiber ice cream

    Directory of Open Access Journals (Sweden)

    Regiane Lopes de Sales

    2008-12-01

    Full Text Available Quatro amostras de sorvete foram preparadas adicionando-se diferentes concentrações de granola e Frutooligossacarídeo (FOS. Foi avaliado o teor de fibras segundo método AOAC. A avaliação da aceitabilidade sensorial foi realizada por 78 consumidores, com idade entre 15 e 25 anos. Estes avaliaram a aceitação global das formulações, utilizando a escala hedônica de nove pontos, em uma única seção, de forma monádica. O experimento foi estruturado segundo delineamento em blocos inteiramente casualizados. Os resultados foram submetidos à análise de variância, ao teste de médias de Tuckey e à metodologia do Mapa de Preferência interno para análise dos componentes principais. As amostras controle e as adicionadas de FOS tiveram melhor aceitação. A amostra contendo somente FOS foi a que mais se aproximou do produto tradicional, não diferindo significativamente quanto à aceitação global. A granola distinguiu-se estatisticamente do produto tradicional. O teor de fibras analisado foi superior ao fornecido pelo fabricante da granola. As concentrações de fibras nos sorvetes variaram de 0,9 a 5,45 g.100 g-1 de sorvete, com a maior concentração de fibras provenientes do FOS. Esse resultado permite concluir que o FOS é um ingrediente promissor no desenvolvimento de produtos ricos em fibras.Four samples of ice cream were prepared with four different concentrations of granola and fructooligosaccharide (FOS. The concentration of fiber was evaluated using the AOAC method. The acceptance evaluation was conducted by 78 consumers between 15 and 25 years of age. The consumers evaluated the global acceptance of the formulations through the structured 9-point hedonic scale, in a single section, in a monadic form. The experiment was structured by a Randomized Complete Block Design. The results were submitted to the analysis of variance, Tukey test, and to the preference mapping technique for principal component analysis. The control samples

  4. Protección contra la oxidación de materiales compuestos SiC(C/SiC mediante la combinación de recubrimientos de silicatos de itrio y sílice

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    Aparicio, M.

    2001-12-01

    Full Text Available The factor which currently precludes the use of carbon fibre reinforced silicon carbide (C/SiC in high temperature structural applications is the oxidation of carbon fibres at temperatures greater than 450ºC (1. For this reason, it is necessary to develop coatings capable of protecting C/SiC components from oxidation for extended periods at 1600ºC. Conventional coatings consist of multilayers of different materials with complementary antioxidant properties. The objective of this work was to develop a multilayer coating consisted by a bonding layer of SiC, a intermediate layer of yttrium silicates: Y2Si2O7 and Y2SiO5, and an external layer of SiO2. Different techniques have been used to prepare the layers: painting with policarbosilane solutions, slip-coating and sol-gel, respectively. The behaviour against oxidation of coated composite material has been evaluated, and the samples before and after oxidation has been characterised by SEM. The cracking of SiC coating leads to a very low oxidation resistance at low temperatures. Only when the substrate is protected by the trilayer coating the reduction of the oxidation rate is considerable, and the weight loss is reduced from 50% (with a SiC coating to 15%.

    El principal inconveniente para la utilización de los materiales compuestos C/SiC en aplicaciones estructurales de alta temperatura es la elevada velocidad de oxidación de la fibra de carbono por encima de 450°C (1. Por esta razón, es necesario el desarrollo de recubrimientos capaces de proteger de la oxidación a estos materiales durante periodos prolongados a temperaturas de hasta 1600°C. Habitualmente, los recubrimientos están formados por multicapas con características antioxidantes complementarias. El objetivo de este trabajo ha sido el desarrollo de un recubrimiento multicapa formado por una capa interior de SiC, una intermedia de silicatos de itrio: Y2Si2O7 y Y2SiO5, y una exterior de SiO2. En su procesamiento se han

  5. Análisis del perfil de compuestos volátiles del mango (mangifera indica l. var. tommy atkins) tratado por métodos combinados

    OpenAIRE

    Moreno, Angélica; León, David F.; Giraldo, Germán A.; Ríos, Eunice

    2010-01-01

    Se evaluó el perfil de compuestos volátiles del mango (Mangifera indica L. Var. Tommy Atkins) al ser tratado con la combinación de los métodos de deshidratación osmótica con o sin pulso de vacío (DOPV y DO) y con secado por aire caliente o con vacío (SAC y VAC). El tiempo utilizado en la cinética del proceso de DO fue de 42 horas y la DOPV de 30 horas; en los procesos de secado, el SAC se realizó durante 24 horas y el VAC requirió 40 horas. En el perfil de compuestos volátiles del mango fresc...

  6. ANÁLISIS DEL PERFIL DE COMPUESTOS VOLÁTILES DEL MANGO (Mangifera indica L. Var. Tommy Atkins) TRATADO POR MÉTODOS COMBINADOS

    OpenAIRE

    Angélica Moreno; David F. León; Germán A. Giraldo; Eunice Ríos

    2010-01-01

    Se evaluó el perfil de compuestos volátiles del mango (Mangifera indica L. Var. Tommy Atkins) al ser tratado con la combinación de los métodos de deshidratación osmótica con o sin pulso de vacío (DOPV y DO) y con secado por aire caliente o con vacío (SAC y VAC). El tiempo utilizado en la cinética del proceso de DO fue de 42 horas y la DOPV de 30 horas; en los procesos de secado, el SAC se realizó durante 24 horas y el VAC requirió 40 horas. En el perfil de compuestos volátiles del mango fresc...

  7. Identificación de los compuestos volátiles de frutos de papaya sin ovipositar y ovipositados por toxotrypana curvicauda (diptera: tephritidae).

    OpenAIRE

    Ruiz Gómez, Olga Lidia

    2016-01-01

    En los tefrítidos la búsqueda, localización y aceptación del hospedero, depende generalmente de estímulos químicos que pueden ser identificados por las hembras a la distancia. La emisión de compuestos volátiles del fruto, puede cambiar con la oviposición y modificar la atracción de las hembras. En el presente estudio se evaluó la atracción de hembras grávidas de Toxotrypana curvicauda hacia frutos de papaya sin ovipositar y ovipositados y se identificaron los compuestos volátiles de los fruto...

  8. Propiedades electrónicas en compuestos intermetálicos de Ce: del cálculo de bandas a las interacciones de muchos cuerpos

    OpenAIRE

    Vildosola, Verónica L.

    2004-01-01

    En este trabajo se estudian las propiedades electrónicas de compuestos de Cerio que se caracterizan por la presencia de electrones 4ƒ. En una primera parte, se llevan a cabo cálculos de primeros principios mediante el método FP-LAPW para analizar el efecto del entorno químico y cristalino en el grado de localización espacial del estado 4ƒ y su relación con el valor del momento magnético de espín del Cerio en un grupo de compuestos de Cerio. Posteriormente, dentro del mismo marco teórico nos a...

  9. Concreto autoadensável reforçado com fibras de aço: comportamento à flexão

    Directory of Open Access Journals (Sweden)

    A. R. Barros

    Full Text Available Este estudo foi desenvolvido para avaliar o comportamento de vigas de concreto autoadensável (CAA reforçado com fibras de aço submetidas à flexão. Para tal, foram utilizadas fibras de aço com fator l/d = 50, em uma fração volumétrica de 1%. Foram confeccionadas vigas armadas de dimensões (12,5 x 23,5 x 132 cm, as quais foram ensaiadas por flexão a quatro pontos, aos 28 dias de idade, sendo feitas medições das deformações apresentadas nos estribos e armadura longitudinal, além de medições das deformações do concreto na região comprimida e das flechas no meio do vão. Os resultados dos ensaios mostraram que a adição das fibras de aço ao CAA promoveu sensível ganho na capacidade resistente da viga, com menores flechas, menores deformações das armaduras, longitudinal e transversal, e melhorado controle da fissuração, em comparação às demais vigas produzidas com concretos convencionais, com e sem fibras de aço.

  10. Fibras reforçadas por resina (FRC em Ortodontia. Versatilidade clínica: parte 2 Fiber reinforced composite (FRC in Orthodontic. Clinical versatility: part II

    Directory of Open Access Journals (Sweden)

    Daniel Ianni Filho

    2005-06-01

    Full Text Available As fibras de vidro e de polietileno podem ser utilizadas na prática ortodôntica em diversas situações clínicas, nos casos com ou sem extrações dentárias. Este artigo tem como objetivo mostrar algumas das aplicações clínicas nas quais as fibras contribuíram de forma significativa para a realização dos tratamentos ortodônticos, simplificando-os e aumentando a eficiência clínica. As fibras foram utilizadas principalmente em segmentos de ancoragem e na substituição da banda pela colagem da associação fibra/tubo nos molares.Glass and polyethylene fibers can be used in orthodontic practice on several clinical(s situations, in cases with or without teeth extraction. The objective of this article is to show some of the clinical applications in which the fibers contributed in a positive way to improve the performance of orthodontic treatments, simplifying and raiseing the clinical efficiency. These fibers were mainly used on anchorage segments, and as a substitute for the band by bonding the fiber/tube association in molars.

  11. EFEITO DE DIFERENTES TEMPOS DE COZIMENTO NOS TEORES DE FIBRAS ALIMENTARES EM FOLHAS DE BRÓCOLIS, COUVE-FLOR E COUVE (BRASSICA OLERACEA L.

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    Mônica Alessandra Teixeira dos SANTOS

    2009-07-01

    Full Text Available

    Foram determinados os teores de fibras alimentares (FDA, FDN, lignina e pectinas das folhas de brócolis e couve-flor e comparados aos teores encontrados nas tradicionais folhas de couve. Os materiais estudados foram cultivados no município de Ijaci MG, com o objetivo da utilização integral dessas hortaliças como fonte alternativa de fibras. As folhas foram submetidas a cocção por seis diferentes tempos (0, 2, 4, 6, 8 e 10 minutos. Acompanhando o comportamento das diversas frações da fibra no material úmido e após secagem. Os resultados mostraram que as folhas de couve-flor e brócolis superaram a couve comum, que apresentou teores superiores apenas na fração FDA do material seco. Os resultados revelaram que as folhas das hortaliças analisadas podem ser consideradas como boas fontes de fibras insolúveis, mas não contribuem significativamente com a porção solúvel.

  12. Sintesis in situ de nanopartículas de peróxido de zinc sobre fibras de plátano con potencial en la industria textil

    Directory of Open Access Journals (Sweden)

    María Estefanía Ballesteros García

    2017-09-01

    Full Text Available El presente trabajo de investigación plantea un desarrollo entorno al manejo de residuos en los cultivos de plátano, siendo una idea sostenible con respecto a la extracción y adquisición de fibras con cualidades innovadoras que posean nanopartículas (NPs de ZnO2 como la capacidad antimicrobiana. La finalidad de la investigación fue la de nanoestructurar fibras provenientes de residuos del plátano con NPs de peróxido de zinc como una propuesta sostenible, teniendo en cuenta factores de optimización en procesos para la síntesis de las nanopartículas. Los resultados más relevantes se obtuvieron en la prueba física microscopia electrónica de barrido (SEM, en donde se destaca el tamaño nanométrico de las partículas sintetizadas de 94 nm. Se demostró el factor hidrofóbico de las fibras de plátano por encima de las fibras de algodón.

  13. Análise quantitativa da camada de fibras nervosas da retina de cães normais e glaucomatosos através da polarimetria a laser

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    Ana Lucia Braga Martins

    2003-01-01

    Full Text Available As lesões glaucomatosas são progressivas e irreversíveis. Estudos sobre o aparecimento e comportamento desta enfermidade vêm sendo discutidos na oftalmologia em geral. O diagnóstico precoce é de extrema importância para o tratamento e estabilização da mesma. A análise da espessura da camada de fibras nervosas retinianas ''in vivo'' foi proposta na oftalmologia humana, para estabelecer as alterações produzidas pelo glaucoma, e tem demonstrado que tais alterações podem ser detectadas até seis anos antes de alterações de campo visual e aumento de pressão intraocular. Entretanto, na Medicina Veterinária, estes dados carecem de estudo e discussão. Neste experimento foram utilizados dois grupos de cães, com olhos normais e olhos glaucomatosos, que foram submetidos à análise das fibras nervosas retinianas através do Analisador de Fibras Nervosas GDx. Os resultados estatísticos demonstraram que a camada de fibras nervosas dos olhos dos cães glaucomatosos estava mais delgada (p < 0,05 quando comparados aos olhos de cães normais, confirmando a perda de axônios das células ganglionares em olhos de cães com glaucoma.

  14. Influência das fibras de aço e das adições minerais na fissuração de tirantes de concreto armado

    Directory of Open Access Journals (Sweden)

    L. A. Oliveira Júnior

    Full Text Available Neste trabalho é investigada a influência das fibras de aço e das adições minerais (sílica ativa e cinza volante na fissuração de tirantes de concreto armado. Fibras de aço com gancho nas extremidades e relação de aspecto igual a 65 foram usadas nas frações volumétricas de 0,75%, 1,00% e 1,50%. Dezesseis tirantes de 800 mm de comprimento e seção transversal quadrada de 150 mm de lado reforçados com uma barra de aço CA-50 de 20 mm de diâmetro foram submetidos à tração axial para determinação das aberturas das fissuras. Os resultados mostraram que as fibras reduziram a abertura média de fissuras em até 75% e que as adições minerais melhoraram o comportamento do concreto na fissuração. As aberturas de fissuras foram comparadas aos valores sugeridos pelas recomendações das normas brasileira, americana e européia, que se mostraram inadequadas para estimar a abertura de fissuras em concretos reforçados com fibras.

  15. Comparación de la microestructura y propiedades de impacto de dos materiales compuestos laminados de acero de ultraalto contenido de carbono

    Directory of Open Access Journals (Sweden)

    Pozuelo, M.

    2004-04-01

    Full Text Available Two ferrous laminated composites containing six layers have been processed by roll bonding. One of them consists of three layers of an ultrahigh carbon steel (1.3%C UHCS interlayered with other three layers of a microalloyed steel. The other composite consists of three layers of UHCS and three layers of a mild steel. Microstructure, Vickers hardness and impact properties have been studied. The absorbed energy values of the two laminated composites were higher than that of the UHCS.

    Se procesaron mediante laminación en caliente dos materiales compuestos laminados de acero de ultraalto contenido de carbono (AUAC, 1,3%C de seis capas cada uno: El primero está compuesto por tres capas de AUAC alternadas con tres capas de un acero microaleado, y el segundo con tres del mismo AUAC alternadas con tres de un acero suave. Se ha realizado un estudio de sus microestructuras, dureza Vickers y propiedades de impacto. Se han mejorado los valores de energía absorbida de los dos materiales compuestos laminados respecto al del AUAC.

  16. Estudio teórico de moléculas de interés en Astrofísica: compuestos binarios policarbonados

    Science.gov (United States)

    Largo-Cabrerizo, A.

    Se han detectado en el espacio distintos compuestos binarios policarbonados (que se pueden formular como CnX), algunos de ellos con elementos de la primera fila del sistema periódico, pero también existen otros que contienen elementos de la segunda fila, como azufre o silicio. La información experimental sobre estos últimos compuestos es escasa, por lo que los estudios teóricos son especialmente valiosos en este campo. En esta comunicación presentaremos los avances mas recientes que sobre el tema ha realizado nuestro grupo. Incidiremos particularmente en dos aspectos. En primer lugar resumiremos los estudios en los que hemos intentado proporcionar información estructural sobre carburos metálicos formados por sodio, magnesio, aluminio o calcio, que pueda ser de ayuda a la hora de caracterizar estas moléculas en laboratorio como paso previo a su eventual detección en el espacio. Un aspecto importante dentro de este primer apartado es el análisis de las propiedades moleculares en función del tamaño del sistema (cuantificado en el numero de átomos de carbono) con el objeto de intentar sistematizar su estudio. En segundo lugar comentaremos brevemente algunos de los estudios realizados sobre posibles reacciones que pueden ser vías de síntesis de este tipo de compuestos en el medio interestelar.

  17. Modificação da rugosidade de fibras de carbono por método químico para aplicação em compósitos poliméricos

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    Burakowski Liliana

    2001-01-01

    Full Text Available O presente trabalho aborda o tratamento superficial de fibras de carbono por ácidos clorídrico e nítrico, visando o aumento controlado da rugosidade superficial da fibra e assim melhorar a ligação fibra/matriz no processamento de compósitos poliméricos reforçados com fibras longas. Foram utilizadas fibras de carbono com size, da empresa Toray. Essas foram tratadas com os ácidos clorídrico e nítrico, a 103°C, em concentrações de 35,5 % e 97 %, em massa, respectivamente, em tempos de exposição de 5, 10, 20, 30, 40 e 60 minutos. As fibras modificadas quimicamente foram caracterizadas por microscopia eletrônica de varredura e por ensaios mecânicos de tração e os dados foram tratados pelo método estatístico de Weibull. Os resultados mostram que os tratamentos empregados modificam a superfície da fibra e que períodos de tratamento superiores a 20 minutos as danificam, degradando de maneira significativa as suas propriedades mecânicas.

  18. Degradabilidad in situ de la materia seca, proteína y fibra del forraje de morera (morus alba

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    Carlos Boschini

    2001-01-01

    Full Text Available Con el propósito de conocer la degradabilidad ruminal de la materia seca, de la proteína cruda, de la fibra neutro detergente y de sus fracciones contenidas en rebrotes de morera de 56, 84 y 112 días. Se determinó la degradación en hojas, tallos y la planta entera. La degradabilidad potencial en los tres componentes estudiados fue disminuyendo conforme aumentó la edad del rebrote. La fracción soluble en la materia seca varió de 29 a 25% en la hoja y de 27 a 19% en el tallo al aumentar la edad de 56 a 112 días. La fracción degradable en la hoja se mantuvo constante en las tres edades (61-63% con tasas de degradación ruminal de 14, 10 y 9%/h a 56, 84 y 112 días. En el tallo la fracción degradable disminuyó de 42 a 30% entre 56 y 112 días con velocidades de degradación de 8,4, 6,7 y 5,3%/h al aumentar la edad. La proteína cruda soluble disminuyó de 41 a 33% en la planta entera, conforme aumentó la edad, y la fracción degradable permaneció constante en 49-51%. La tasa de degradación fue superior a 9,4%/h. La fibra neutro detergente presentó una fracción degradable de 71%, 62% y 43% a 56, 84 y 112 días respectivamente, con tasas de degradación de 13, 10 y 9%/h en el mismo orden. La degradación de la fibra neutro detergente se inició en el rumen con un tiempo de rezago de 1,5 a 3,2 horas

  19. DESENVOLVIMENTO DE PRODUTO À BASE DE FIBRAS DE BETERRABA (BETA VULGARIS VARIEDADE AÇUCAREIRA

    Directory of Open Access Journals (Sweden)

    CLáUDIA HELENA DEGÁSPARI

    2009-07-01

    Full Text Available

    O presente trabalho procurou desenvolver um produto para atender os indivíduos com doença celíaca. O produto escolhido foi uma formulação de quibe na forma frita. Os testes foram realizados comparando-se uma formulação de quibe contendo trigo integral moído com uma formulação que substituá 100% do trigo por fibra de beterraba (Fibrex® As formulações foram desenvolvidas apenas em protótipo de produto para demonstrar a aplicabilidade deste, submetendo-as a testes de análise sensorial de preferência com emprego do método de escala hedônica, com uma equipe de vinte provadores semitreinados. Os diversos testes sensoriais realizados demonstraram que tanto a formulação com trigo integral quanto a com fibra de beterraba mostraram-se sensorialmente adequadas, sem diferenças entre si nos parâmetros sensoriais avaliados, exceto no atributo aroma em que o resultado apontou uma diferença significativa de 5% em favor da formulação com fibra de beterraba. Pelos resultados de aceitabilidade, acredita-se ter esse produto um bom potencial de comercialização, principalmente para o público portador de doença celíaca. Da mesma forma, os cálculos de estimativa realizados para verificar o possível aumento no custo final do produto demonstraram que este não interfere significativamente, uma vez que o ingrediente que se apresenta com maior contribuição no custo final é a carne.

  20. Evaluación del comportamiento de vigas en voladizo de concreto reforzado con fibras ante la aplicación de cargas cíclicas

    Directory of Open Access Journals (Sweden)

    Daniel Ruiz

    2015-04-01

    Full Text Available El concreto es un material frágil con poca resistencia a la tensión y que no desarrolla grandes deformaciones en el rango inelástico. Para mejorar estas propiedades mecánicas del concreto, en las últimas décadas se han usado adiciones de fibras en aplicaciones estructurales en Colombia, Suramérica. En este documento los autores presentan el comportamiento mecánico de vigas en voladizo hechas con tres diferentes mezclas de concreto: una de concreto normal y dos con dos diferentes porcentajes de adición de fibras de acero (adiciones de fibras metálicas en una proporción de 15 kg/m³ y 30 kg/m³. Todas las vigas fueron ensayadas con desplazamientos cíclicos que fueron aplicados con un actuador dinámico. Todas las vigas fueron ensayadas para evaluar sus ciclos de histéresis y su capacidad de disipación de energía. Con base en los resultados y para el mismo nivel de desplazamiento, las vigas de concreto reforzado adicionado con fibras disiparon 160% más energía que las elaboradas con concreto reforzado normal. Adicionalmente las fibras metálicas disminuyeron la cantidad y la longitud de las grietas y las fisuras para grandes desplazamientos. Estas características pueden ser benéficas para aplicaciones estructurales específicamente para mejorar el desempeño sísmico de estructuras de concreto.