WorldWideScience

Sample records for avanzada pudiese ser

  1. marginalidad avanzada

    Directory of Open Access Journals (Sweden)

    Loïc Wacquant

    2007-01-01

    Full Text Available La sociología comparada de la estructura, la dinámica y la experiencia de la relegación urbana en Estados Unidos y en los principales países de la Unión Europea durante las tres décadas pasadas revela no una convergencia sobre el patrón del ghetto estadounidense, según afirman los medios dominantes y el discurso político sino la aparición de un nuevo régimen de marginalidad. Este régimen genera formas de pobreza que no son residuales, cíclicas ni de transición sino inscritas en el futuro de las sociedades contemporáneas en cuanto se nutren de la desintegración del salariado, de la desconexión funcional entre los barrios desheredados de las economías nacionales y globales, y de la reconfiguración del Estado benefactor como un instrumento para hacer que se cumpla la obligación del trabajo asalariado en la ciudad polarizante. Con base en una comparación metódica de la evolución del ghetto negro estadounidense y del suburbio obrero (banlieue francés a principios del siglo, así como una indagación selectiva de las formas cambiantes de las relaciones sociales y la experiencia cotidiana en barrios relegados en otras sociedades avanzadas, este artículo destaca tres propiedades espaciales distintivas de la “marginalidad avanzada” y sus implicaciones en cuanto a la formación del “precariado” en las sociedades postindustriales.

  2. Ser hija, ser madre

    OpenAIRE

    Sánchez Terrer, Zaida

    2015-01-01

    La maternidad vista desde el punto de vista de ser hijas. Cómo se identifican las mujeres con su modelo de madre y cómo configuran su relación con otras mujeres y desarrollan su propia experiencia maternal Maternidad, Mujer, Hijas, Madres

  3. ¿Qué hacemos con un hipertenso de edad avanzada?

    Directory of Open Access Journals (Sweden)

    Nancy Guinart Zayas

    Full Text Available Constituye la hipertensión arterial un problema médico de primera magnitud, no solo por las consecuencias que provoca, fundamentalmente complicaciones de tipo cardiovascular (infarto del miocardio, arteriopatías periféricas, infarto cerebral, nefroangioesclerosis, etc., sino también por ser una alteración muy frecuente en los pacientes de edad avanzada, en los que constituye el principal factor de riesgo cardiovascular. Su detección precoz está a cargo de los Médicos de Familia.

  4. Decisiones compartidas en la enfermedad avanzada

    Directory of Open Access Journals (Sweden)

    Mª Aránzazu García Martínez

    2013-12-01

    Full Text Available Tomar decisiones es una práctica diaria de todo ser humano. Hay decisiones sencillas, con pocos valores en juego, con con secuencias poco importantes y en las que solo una persona está implicada y otras más complejas y con consecuencias irreversibles.

  5. Ser reina

    Directory of Open Access Journals (Sweden)

    José Manuel NIETO SORIA

    2006-07-01

    Full Text Available L’historiographie du règne des Rois Catholiques, héritière directe de celle des autres Trastamare, se caractérise par son étroite relation avec des enjeux politiques concrets. L’activité historiographie s’est ainsi inscrite elle-même dans le cadre des conflits politiques en cours. C’est pourquoi la royauté d’Isabelle Ire de Castille impliqua une bonne part de la production historiographique de cettte époque : soit qu’on dénonçât un déficit de légitimité dû à sa condition féminine, soit qu’on démentît, au contraire, ce déficit en attribuant à la reine des qualités « masculines ». Bien entendu, ces débats furent fonction de l’engagement politique de chacun des historiens.La cronística y la historiografía del reinado de los Reyes Católicos, como directas herederas de la labor historiográfica de la época de los monarcas Trastámara, se caracterizó por su estrecha vinculación con intereses políticos concretos, inscribiéndose la propia actividad historiográfica en el marco de los conflictos políticos en curso. Por ello, la dimensión regia de Isabel I de Castilla supuso una dimensión significativa del quehacer historiográfico de la época, bien para plantear un déficit de legitimidad por razón de su propia condición femenina, bien para negar tal déficit con la atribución de “cualidades masculinas” en su persona. De este modo, la toma en consideración del hecho de “ser reina” representó una dimensión significativa del quehacer historiográfico, de acuerdo siempre con los compromisos políticos de los distintos historiadores de la época.

  6. Persistent misconceptions regarding SERS.

    Science.gov (United States)

    Moskovits, Martin

    2013-04-21

    SERS is some 35 years old, and the subject of over 11 000 articles. The field of Plasmonics, and large aspects of Metamaterials are clearly based on concepts that became current as a result of SERS. Despite this, a number of persistent, fuzzy ideas about the origin of the enhancement in SERS continue to be current even among SERS researchers, leading to the external impression that SERS is uniquely poorly understood. Six such ideas are discussed.

  7. Vacunas para la prevención de la gripe en personas de edad avanzada

    OpenAIRE

    Jefferson, Tom; Di Pietrantonj, Carlo; Al-Ansary, Lubna A.; Ferroni, Eliana; Thorning, Sarah; Thomas, Roger E.

    2010-01-01

    Antecedentes: Durante las últimas cuatro décadas, las vacunas han sido la principal arma global para disminuir la repercusión de la gripe en las personas de edad avanzada, y a nivel mundial se recomiendan para los individuos de 65 años o más de edad. El objetivo principal de la vacunación contra la gripe en las personas de edad avanzada es reducir el riesgo de complicaciones en quienes son más vulnerables. Objetivos: Evaluar la efectividad de las vacunas sobre la prevención de la gripe, la...

  8. La Psicoterapia de grupos en la crisis vital de la edad avanzada

    Directory of Open Access Journals (Sweden)

    Margarita Robertazzi

    2015-09-01

    Full Text Available Este artículo se propone narrar algunos aspectos del recorrido realizado por un grupo psicoterapéutico constituido por mujeres de edad avanzada y que lleva, hasta la actualidad, diez años de funcionamiento. Tomando como punto de partida esta experiencia, se desarrollan estos cuatro tópicos: el tratamiento grupal como una elección adecuada en las crisis vitales de la edad avanzada, algunas características de esta etapa evolutiva, las particularidades que la misma adquiere en un país como el nuestro y, finalmente, algunos prejuicios sobre la vejez que resultan obstaculizadores en el trabajo profesional con este tipo de pacientes. 

  9. Los retos del proceso de socialización en los sistemas educativos de las sociedades modernas avanzadas Los retos del proceso de socialización en los sistemas educativos de las sociedades modernas avanzadas

    Directory of Open Access Journals (Sweden)

    José María PéREz-AGOTE

    2010-07-01

    Full Text Available The crisis of modernity is particularly evident in the educational systems of advanced societies. These societies project on school systems more paradoxes and contradictions than they can really cope with. In the face of the deep transformations that concepts such as globalization, information and consumer society, postmodernity or reflexive modernity appear to claim, schools are losing their ability to successfully transmit models of identity and citizenship. This article explores the crisis of the socialising function of educational systems, and in particular the decline of the emancipatory goals this function is aimed at in its bureaucratic, systemic and communicative dimensions. In this way, the traditional strategies of socialization in advanced societies loose pace, and a restructuring is required. This restructuring should be tackled by departing from an eligibility horizon which in turn should be articulated by an ethos of desire.La crisis de la modernidad se manifiesta con gran crudeza en los sistemas educativos de las sociedades avanzadas, que proyectan sobre aquéllos más contradicciones y paradojas de las que pueden superar. Ante las profundas transformaciones invocadas por conceptos como globalización, sociedad de la información y/o del consumo, postmodernidad o modernidad reflexiva, las instituciones escolares están perdiendo su capacidad de transmitir modelos de identidad y ciudadanía eficazmente. Este trabajo explora la crisis de la función socializadora de los sistemas educativos, entendida como un declive sistémico, burocrático y comunicativo. De este modo, las clásicas estrategias de socialización propias de las sociedades modernas pierden su eficacia, siendo precisa su reconversión. Ésta puede ser afrontada orientando los procesos de socialización desde un horizonte de elegibilidad articulado por un ethos del deseo.

  10. Household arrangements of the elder elderly Arreglo domiciliar de los ancianos de edad avanzada Arranjo domiciliar dos idosos mais velhos

    Directory of Open Access Journals (Sweden)

    Elizandra Cristina Pedrazzi

    2010-02-01

    Full Text Available The aging context of the elder elderly needs to be taken into account, due to the redefinition of family as a social institution. This is an epidemiological, cross-sectional study that characterized the household arrangements of 147 elder elderly living in Ribeirão Preto, SP, through home interviews. The age range between 80 and 84 years predominated. The majority receives a retirement benefit ranging from one to three minimum wages, and owns their house. On the average, they have 4.08 children and live with 2.8 people. Most men live with their partners, while women live by themselves. The elderly head a large part of households. The most frequent arrangements are families with two and three generations. Regarding the household arrangement, there was equivalence in the results between the ones that moved into the house of the elderly and cases when the elderly moved into the family’s house, reinforcing the family as a protector and caregiver of the elderly.El contexto del envejecimiento de ancianos con edad avanzada necesita ser considerado como una consecuencia de la redefinición de la familia como institución social. Este es un estudio epidemiológico, transversal, que caracterizó el arreglo domiciliar de 147 ancianos con edad avanzada residentes en la comunidad de Ribeirao Preto, Sao Paulo, Brasil, a través de entrevistas domiciliares. Predominó el intervalo de edad de 80 a 84 años. La mayoría era jubilado, recibía de un a tres salarios mínimos y habitaba en casa propia. Tenían 4,08 hijos y vivían con 2,8 personas, en promedio. Los hombres vivían, en su mayoría, con el conyugue, en cuanto las mujeres, lo hacían solas, y los domicilios eran dirigidos por el anciano. Los arreglos más convenientes fueron los realizados con la segunda y tercera generaciones. En cuanto a la formación del arreglo domiciliar, hubo equivalencia en los resultados, entre aquellos que afirmaron haber ido a vivir con el anciano y aquellos en que el

  11. Valoración del dolor en pacientes con demencia avanzada institucionalizados

    Directory of Open Access Journals (Sweden)

    Marisa de la Rica Escuín

    Full Text Available Introducción: el dolor es un síndrome geriátrico que altera la calidad de vida de la persona y su entorno. Además, los pacientes con demencia avanzada son personas con expectativa de vida corta. Una valoración adecuada de un síntoma tan subjetivo requiere disponer de información por parte de los cuidadores habituales. Los cuidados paliativos deberían extenderse a patologías no oncológicas: la National Hospice Organization (NHO establece criterios para pacientes con demencia avanzada. Método: estudio descriptivo transversal. Área y población: 20 pacientes con criterios de demencia avanzada ingresados en la Residencia de Mayores "Núñez de Balboa" de Albacete. Desarrollado entre el 1 de marzo y el 15 de mayo de 2012. Criterios de inclusión: firma del consentimiento informado por parte del representante legal, tutor, familiar o cuidador. Variables: sociodemográficas: edad, sexo, tiempo de ingreso y relación familiar; clinicoasistenciales: patologías, criterios de demencia avanzada, registro de dolor, tratamiento analgésico, valoración del dolor por la escala PAINAD, valoración de depresión por la escala de Cornell, valoración conductual por la NPI-NH y criterios de terminalidad según la NHO. Análisis estadístico SPSS 15. Conclusiones: el dolor es causa de deterioro funcional multifactorial; identificarlo requiere valoración multidisciplinar. Está relacionado con depresión y con síntomas psicológicos y conductuales, es frecuente en residencias, y está infradiagnosticado e infratratado. Los residentes con deterioro cognitivo y pluripatología son población creciente; las residencias pueden constituirse en centros de cuidados paliativos. El personal sanitario requiere herramientas de detección del dolor para usuarios con demencias avanzadas; las escalas observacionales son un buen instrumento para valorarlo.

  12. Análisis de las tendencias en el desarrollo de las tecnologías de avanzada para la producción de citostáticos

    Directory of Open Access Journals (Sweden)

    Thamara Figueroa Rodríguez

    2003-08-01

    Full Text Available El desarrollo de tecnologías de avanzada para la preparación de citostáticos cobra especial interés por la baja selectividad de estos medicamentos y con ello su alta toxicidad. La aplicación de quimioterapéuticos que se emplean en el tratamiento del cáncer mediante las tecnologías de avanzada puede ser una de las más importantes alternativas para mejorar la eficacia de los tratamientos y la calidad de vida de los enfermos. Este trabajo de investigación se desarrolló para valorar la tendencia actual del comportamiento de las tecnologías de avanzada para los medicamentos genéricos empleados en la quimioterapia del cáncer, evaluando los autores y entidades líderes a nivel mundial, así como la actividad científica de esta temática y el estado del proceso de tramite de las patentes.The development of state-of-the-art technologies for the preparation of cytostatics acquires special interest owing to both the low selectivity of these drugs and their high toxicity. The application of chemotherapeutic drugs in the treatment of cancer through state-of-the-art techniques may be one of the most important choices for improving the efficacy of therapies and the quality of life of patients. This research paper was aimed at assessing the present trend in the behavior of such technologies for the generic drugs for cancer chemotherapy , taking the evaluation of world leading authors and organizations and the scientific activity in this field as well as the process of application for patents as a basis.

  13. Review on SERS of Bacteria

    Directory of Open Access Journals (Sweden)

    Pamela A. Mosier-Boss

    2017-11-01

    Full Text Available Surface enhanced Raman spectroscopy (SERS has been widely used for chemical detection. Moreover, the inherent richness of the spectral data has made SERS attractive for use in detecting biological materials, including bacteria. This review discusses methods that have been used to obtain SERS spectra of bacteria. The kinds of SERS substrates employed to obtain SERS spectra are discussed as well as how bacteria interact with silver and gold nanoparticles. The roll of capping agents on Ag/Au NPs in obtaining SERS spectra is examined as well as the interpretation of the spectral data.

  14. Machi Zugu: Ser Machi

    Directory of Open Access Journals (Sweden)

    José Quidel Lincoleo

    Full Text Available El presente trabajo tiene como primer objetivo provocar una discusión interna acerca de la institución del machi. Por ende un objetivo formativo hacia nuestra sociedad como asímismo hacia la juventud que acude al respaldo escrito de los conocimientos mapuche.El segundo objetivo es más bien de carácter político cultural dirigido a la sociedad nacional que aparece necesario ante las reiteradas imprecisiones que ocurren permanentemente acerca del tema de lo que es SER machi, MACHIGEN; específicamente a las definiciones de machi que surgieron en un texto escolar de circulación nacional y el cual provocó un alto nivel de critica en las distintas esferas de las instituciones mapuche y no mapuche.

  15. EVALUACIÓN DE GLIOMAS POR TÉCNICAS AVANZADAS DE RESONANCIA MAGNÉTICA

    Directory of Open Access Journals (Sweden)

    Dra. Cecilia Okuma, PhD

    2017-05-01

    Full Text Available Los gliomas cerebrales son la neoplasia maligna cerebral primaria más frecuente, y habitualmente se asocian a mal pronóstico. La técnica imagenológica de elección para su estudio es la resonancia magnética (RM. Si bien las secuencias convencionales de RM permiten una adecuada aproximación diagnóstica, frecuentemente son insuficientes para caracterizar tumores de naturaleza compleja como los gliomas cerebrales. Durante los últimos 30 años, se han desarrollado técnicas avanzadas de RM, entre las que se incluyen la difusión, perfusión y espectroscopía por RM, las que permiten evaluar distintas características fisiopatológicas de los gliomas cerebrales. En esta revisión, se discutirán brevemente los principios físicos de las técnicas avanzadas de RM y su relación con los mecanismos fisiopatológicos de este tipo de tumores. Además, se revisará en detalle la evidencia que sustenta el uso de las distintas técnicas en escenarios clínicos específicos, planificación terapéutica y evaluación de respuesta a tratamiento, incluyendo la revisión de los criterios imagenológicos de respuesta más utilizados actualmente y los conceptos de RM precoz, pseudoprogresión, pseudorespuesta y radionecrosis. Finalmente, se mencionará la relación entre técnicas imagenológicas y las mutaciones del gen IDH 1/2, la que constituye actualmente un importante foco de interés en la investigación en neurooncología.

  16. Cómo puede contribuir Twitter a una comunicación política más avanzada

    Directory of Open Access Journals (Sweden)

    Moya Sánchez, Miguel

    2015-08-01

    Full Text Available With the incorporation of innovative functionalities –retweets, mentions, replies and hashtags– Twitter has become a favourite platform for political activism. Since its initial conception as a channel for personal updates, Twitter has turned into a medium for communication and political cooperation. Twitter has facilitated the emancipation of citizens and has aroused the interest of the political leadership. It has also attracted the attention of the research community, which has highlighted those aspects that make Twitter ideal for advanced communication. Through a bibliographic review of outstanding contributions, we have obtained the basis for developing a Decalogue of its utilities for and horizontal political communication that provides transparency and promotes citizen participation.La incorporación de nuevas funcionalidades –retuits, menciones, respuestas y etiquetas– ha convertido a Twitter en un espacio preferido para el activismo político. De ser un canal concebido para actualizaciones personales ha pasado a ser un medio para la comunicación, la conversación y la concertación política. Twitter ha demostrado su capacidad para facilitar la emancipación informativa de los ciudadanos. Esto ha despertado el interés de la dirigencia política y también ha llamado la atención de la comunidad investigadora que viene destacando aquellas facetas de Twitter que lo hacen idóneo para una comunicación avanzada. A través de un recorrido bibliográfico sobre las contribuciones más destacadas respecto al potencial que ofrece Twitter para la comunicación, hemos obtenido los fundamentos para elaborar un decálogo de sus competencias y utilidades para una comunicación política horizontal que facilite la transparencia y promueva la implicación ciudadana.

  17. Aprendendo a ser psicoterapeuta

    Directory of Open Access Journals (Sweden)

    Elizabeth Amelio Faleiros

    Full Text Available Este estudo investiga, na perspectiva de Jacob Levy Moreno, a concepção que alunos de Psicologia têm sobre o que é ser psicoterapeuta, quais elementos são necessários para o desenvolvimento dessa tarefa e os fatores impeditivos para realizá-la. Propõe formas de soluções para o desempenho daquela função, favorecendo a reflexão sobre a importância dessa tarefa e a responsabilidade do profissional junto ao paciente. A metodologia utilizada é a qualitativa, pois esta permite abordar dimensões da subjetividade dos sujeitos. Os resultados revelam que os alunos possuem em sua concepção os alicerces básicos, cujos indicadores são apontados por Moreno e por outros autores, percebem os requisitos básicos que constituem a essência do papel de terapeuta, evidenciam críticas realistas sobre os fatores limitadores e sugerem ações pedagógicas para minimizá-los.

  18. Bloqueo del sistema renina-angiotensina-aldosterona en pacientes con enfermedad renal diabética avanzada

    Directory of Open Access Journals (Sweden)

    Sheila Bermejo

    2018-03-01

    Conclusiones: El tratamiento con BSRAA es más frecuente en pacientes con FGe≥30 mL/min/1,73m2. No observamos diferencias en la evolución de la función renal entre los tres grupos. La mayor mortalidad observada en pacientes que no recibieron BSRAA se relacionó con la edad avanzada y peor función renal.

  19. Plan de cuidado a personas de edad avanzada en riesgo nutricional

    Directory of Open Access Journals (Sweden)

    Irene García-Izquierdo

    Full Text Available Introducción: La intervención de enfermería es determinante en la identificación de las personas en riesgo nutricional mediante la inclusión de pruebas de cribado dentro del plan de cuidados enfermero a personas de edad avanzada. Esto facilitaría la identificación precoz de individuos en riesgo nutricional, así como el enunciado de propuestas de intervención para reducir la morbimortalidad de este grupo poblacional. Desarrollo del plan de cuidados: Se han seleccionado dos escalas de cribado nutricional, entre las disponibles en la literatura especializada, para su aplicación por los profesionales de enfermería, y se han propuesto dos diagnósticos enfermeros para el diseño de un plan de cuidados sistematizado que sirva de guía para llevar a cabo una atención individualizada. Discusión: Se propone realizar, mediante intervenciones enfermeras, atención a la salud nutricional, en respuesta a la demanda de las instituciones europeas de luchar contra la desnutrición.

  20. EXPERIENCIAS CONSTRUCCIONISTAS CON ROBÓTICA EDUCATIVA EN EL CENTRO INTERNACIONAL DE TECNOLOGÍAS AVANZADAS

    Directory of Open Access Journals (Sweden)

    Kathia Pittí

    2010-02-01

    Full Text Available La tecnología digital en relación a su utilización en el ámbito educativo tienen dos vertientes: la de información y la de construcción. Aunque el énfasis actual, debido a la percepción popular, se inclina a la parte informativa, este trabajo descubre una parte olvidada del potencial que ofrece la tecnología digital como medio de construcción, específicamente la robótica educativa, que por su carácter polivalente y multidisciplinario se sitúa como una herramienta de apoyo al aprendizaje novedosa y necesaria de conocer por las nuevas generaciones.En este sentido, como ejemplo de buenas prácticas presentamos los talleres NXT de robótica del Centro Internacional de Tecnologías Avanzadas, un escenario construccionista de aprendizaje activo y lúdico, que les permite a los participantes mejorar su comprensión de la tecnología, potenciar habilidades y desarrollar la creatividad.

  1. Procesos de oxidación avanzada para el tratamiento de aguas residuales industriales contaminadas con 1,4 dioxano

    OpenAIRE

    Barndok, Helen

    2016-01-01

    La mayor concienciación medio ambiental, una legislación cada vez más rigurosa, la optimización de los circuitos de agua, la reutilización de los efluentes industriales, así como los nuevos métodos de monitorización y control, obligan al desarrollo de nuevas tecnologías, cada vez más avanzadas, que permitan una mejor depuración de las aguas residuales industriales. Entre los contaminantes comunes en las aguas residuales industriales están los disolventes orgánicos, usados como productos de li...

  2. Stamping SERS for creatinine sensing

    Science.gov (United States)

    Li, Ming; Du, Yong; Zhao, Fusheng; Zeng, Jianbo; Santos, Greggy M.; Mohan, Chandra; Shih, Wei-Chuan

    2015-03-01

    Urine can be obtained easily, readily and non-invasively. The analysis of urine can provide metabolic information of the body and the condition of renal function. Creatinine is one of the major components of human urine associated with muscle metabolism. Since the content of creatinine excreted into urine is relatively constant, it is used as an internal standard to normalize water variations. Moreover, the detection of creatinine concentration in urine is important for the renal clearance test, which can monitor the filtration function of kidney and health status. In more details, kidney failure can be imminent when the creatinine concentration in urine is high. A simple device and protocol for creatinine sensing in urine samples can be valuable for point-of-care applications. We reported quantitative analysis of creatinine in urine samples by using stamping surface enhanced Raman scattering (S-SERS) technique with nanoporous gold disk (NPGD) based SERS substrate. S-SERS technique enables label-free and multiplexed molecular sensing under dry condition, while NPGD provides a robust, controllable, and high-sensitivity SERS substrate. The performance of S-SERS with NGPDs is evaluated by the detection and quantification of pure creatinine and creatinine in artificial urine within physiologically relevant concentration ranges.

  3. SERS substrate and a method of providing a SERS substrate

    DEFF Research Database (Denmark)

    2011-01-01

    Source: US2011116089A A substrate primarily for SERS determination, the substrate has a number of elongate elements with a density of at least 1x108 elongate elements per cm2 and having metal coated tips. When the elements may be made to lean toward each other, such as by providing a drop...

  4. Edad avanzada y factores de riesgo para infarto agudo de miocardio

    Directory of Open Access Journals (Sweden)

    M. A. Ciruzzi

    2002-12-01

    Full Text Available Este estudio caso-control analizó en los sujetos añosos el rol de los factores de riesgo coronario en el desarrollo del infarto agudo de miocardio (IAM, estableció la naturaleza de esta asociación y el grado de riesgo. Los datos fueron obtenidos en una investigación que incluyó 1060 casos y 1071 controles, realizada en 35 unidades coronarias de centros médicos de Argentina entre noviembre de 1991 y agosto de 1994. Nuestro análisis se basó en la información de los sujetos mayores de 65 años. Los casos fueron 427 pacientes con un primer IAM. Los controles fueron 396 sujetos sin evidencias clinicas de enfermedad cardiovascular, seleccionados en los mismos centros que los casos. Los Odds Ratios (OR y su intervalo de confianza del 95% (IC 95% se obtuvieron mediante un análisis de regresión logística, incluyendo variables como la edad, educación, clase social, tabaquismo, antecedente de diabetes o hipertensión arterial, índice de masa corporal e historia familiar de enfermedad coronaria. Los factores de riesgo relacionados independientemente con IAM fueron los siguientes: hipercolesterolemia (colesterol sérico > 240 mg/dl: OR=1.76 (IC 95%: 1.25-2.49, tabaquismo: OR=1.6 (IC 95%: 1.06-2.4, hipertensión arterial: OR=2.05 (IC 95%: 1.51-2.73, diabetes OR=1.71 (IC 95%: 1.12-2.70, historia de un familiar con enfermedad coronaria: OR=1.36 (IC 95%: 0.93-1.97 y de dos o más familiares: OR=2.63 (IC 95%: 1.21-5.71. Este estudio, confirma en los sujetos de edad avanzada la importancia de la hipercolesterolemia, del tabaquismo, la hipertesión arterial, la diabetes y la historia familiar de enfermedad coronaria como factores de riesgo de IAM

  5. Calidad de vida y bienestar psicológico en pacientes adultos con enfermedad avanzada y en cuidado paliativo en Bogotá

    OpenAIRE

    Mónica María Novoa Gómez; Claudia Caycedo; Mónica Aguillón; Raquel Andrea Suárez Álvarez

    2008-01-01

    El presente estudio evaluó la calidad de vida y el bienestar psicológico de pacientes oncológicos con diagnóstico de enfermedad avanzada y que al momento de la evaluación se encontraban en cuidado paliativo en la ciudad de Bogotá. La muestra estuvo constituida por 83 personas mayores de edad de ambos sexos, con diversos tipos de enfermedad oncológica y con diagnóstico de enfermedad avanzada. Previa firma del consentimiento informado, los instrumentos que se aplicaron fueron un Registro de Dat...

  6. La importancia de ser grande

    OpenAIRE

    Baisre, J. A.

    2007-01-01

    Se responde a las preguntas ¿por qué los mamíferos marinos son los animales más grandes del planeta?, ¿Por qué los peces no pueden ser más grandes?. Éstas y otras interrogantes son respondidas de forma sencilla y clara.

  7. Ingreso y bienes de la población de edad media y avanzada en México*

    Science.gov (United States)

    Wong, Rebeca; Espinoza, Mónica

    2017-01-01

    Resumen El propósito de este artículo es resumir el monto y los tipos de ingreso que percibe y bienes que posee la población de edad media y avanzada en México. Se usan datos de la nueva Encuesta Nacional sobre Salud y Envejecimiento en México (Enasem) 2001, un estudio prospectivo de panel con representación nacional de las personas de 50 años de edad y más. Los resultados confirman las hipótesis formuladas: la distribución del ingreso y la riqueza están sesgadas en favor de ciertos grupos, sobre todo aquéllos con mayor educación; la composición de la riqueza se da principalmente en forma no financiera y el apoyo familiar es una fuente de ingreso importante; la asociación entre riqueza y salud es positiva en general, lo cual es consistente con la literatura internacional. Además se encuentra que la riqueza acumulada está distribuida más equitativamente que el ingreso, y se concluye que el indicador de riqueza ofrece una dimensión de análisis adicional al ingreso, con potencial para contribuir a los estudios del bienestar de la población en edad media y avanzada en México. PMID:29386981

  8. Aplicación de técnicas clásicas y avanzadas de procesamiento de vibraciones al diagnóstico de cojinetes. Análisis experimental.

    Directory of Open Access Journals (Sweden)

    F. E. Hernández Montero

    2007-01-01

    Full Text Available El siguiente trabajo consiste en la aplicación de las técnicas de procesamiento de señal más importantes al análisis de vibraciones para el diagnóstico de los cojinetes de rodamientos, aunque pueden ser extendidos a otros tipos de componentes. Se efectúa una caracterización de las técnicas clásicas y avanzadas que más se emplean, en este caso, los análisis espectral, cepstral, de envolvente, de tiempo-frecuencia, estadístico de orden superior y cicloestacionario, y se muestra la manera en que se aplican en la tarea de detección de un desperfecto en un cojinete de rodamientos, siguiendo un enfoque simulado y otro experimental.This work relates the application of several signal processing techniques on rotating machine condition diagnosis, specifically, roller-ball bearings. These methods can be extended to the diagnosis of other machine components. Classical and advanced techniques are characterized and applied on the detection of localized bearing failures (in this work, outer raceway crack, in particular, spectral, cepstral, envelope, time-frequency, bispectral and cyclostationary analysis. These methods were applied on simulation and experimental signals processing

  9. Prevalencia y evaluación de síntomas en enfermedad renal crónica avanzada

    OpenAIRE

    Daniel Gutiérrez Sánchez; Juan P. Leiva-Santos; Rosa Sánchez-Hernández; Rafael Gómez García

    2015-01-01

    El paciente con enfermedad renal crónica avanzada (ERCA) presenta una elevada carga de síntomas que contribuyen a un aumento del sufrimiento y disminuyen su calidad de vida. El uso de instrumentos de evaluación es esencial para el control de síntomas. El objetivo de esta revisión es obtener una visión contrastada de los instrumentos más usados para evaluar síntomas en ERCA, realizando una descripción de la prevalencia de síntomas en esta población. Método: Se realizó una revisión de la litera...

  10. Ingreso y bienes de la población de edad media y avanzada en México

    OpenAIRE

    Rebeca Wong; Mónica Espinoza

    2003-01-01

    El propósito de este artículo es resumir el monto y los tipos de ingreso que percibe y bienes que posee la población de edad media y avanzada en México. Se usan datos de la nueva Encuesta Nacional sobre Salud y Envejecimiento en México (Enasem) 2001, un estudio prospectivo de panel con representación nacional de las personas de 50 años de edad y más. Los resultados confirman las hipótesis formuladas: la distribución del ingreso y la riqueza están sesgadas en favor de ciertos grupos, sobre tod...

  11. Programa de Tecnologías Educativas Avanzadas: Una reseña histórica

    Directory of Open Access Journals (Sweden)

    Alonso Delgado, Julia

    2007-11-01

    Full Text Available Resumen: Reseña Histórica. El propósito de este artículo es presentar un recorrido, desde las circunstancias que llevaron a su creación, los momentos claves en su desarrollo y consolidación, así como los logros más significativos y la visión de futuro del Programa de Tecnologías Educativas Avanzadas (PROTEA del Decanato de la Facultad de Educación de la Universidad de Costa Rica.Abstract:Historical review. The purpose of this article is to present a route, from the most significant circumstances that took to their creation, the key moments in their development and consolidation, as well as profits and the vision towards the future of the Program of Educative Technologies Advanced ((PROTEA for its acronym in Spanish of the Deanship of the Faculty of productividadn of the University of Costa Rica.

  12. Peculiaridades no pós-operatório de cirurgia cardíaca no paciente idoso Peculiaridades en el post operatorio de cirugía cardíaca en el paciente de edad avanzada Peculiarities of post-cardiac surgery care in elderly patients

    Directory of Open Access Journals (Sweden)

    Paulo de Oliveira Vasconcelos Filho

    2004-10-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O paciente idoso tem características fisiológicas próprias e, muitas vezes, pode apresentar deficiências orgânicas ou afecções graves, que por si, já tornam o pós-operatório complicado. O objetivo deste artigo é apresentar uma revisão das condutas pós-operatórias de cirurgia cardíaca no idoso, apresentando as alterações mais freqüentes nesse tipo de paciente. CONTEÚDO: As condutas no período intra-operatório do paciente idoso devem ser tomadas tendo em vista a diminuição da morbidade pós-operatória. Na chegada do paciente idoso à UTI, devem ser cumpridos os mesmos critérios utilizados na internação de outros pacientes adultos de cirurgia cardíaca, para o serviço ter sempre um padrão, que não leve a uma alteração na rotina e que não provoque equívocos. Estabelecer um plano de cuidados intensivos para o pós-operatório de cirurgia cardíaca irá resultar em uma ótima utilização de recursos da unidade, em efetividade de atenção e em diminuição do tempo nos cuidados em relação ao paciente idoso. Os exames auxiliares solicitados também devem seguir um padrão, estabelecido pelo serviço, a não ser que alterações sejam identificadas. Complicações neurológicas, pulmonares, circulatórias, insuficiência renal, infecção e hipotireoidismo são freqüentes, com particularidades no idoso. Elas estão delineadas neste artigo e devem ser bem compreendidas pelo intensivista que cuida desse tipo de paciente. CONCLUSÕES: As complicações apresentadas neste artigo são as que trazem maior preocupação ao intensivista, quando há um paciente idoso em pós-operatório de cirurgia cardíaca na UTI. Este paciente necessita de cuidados especiais, mesmo quando a cirurgia transcorre em perfeita normalidade, pois o estresse cirúrgico é muito grande e o idoso tem reserva funcional diminuída.JUSTIFICATIVA Y OBJETIVOS: El paciente de edad avanzada tiene características fisiol

  13. for SERS and Photocatalytic Applications

    Directory of Open Access Journals (Sweden)

    Xue Chen

    2011-01-01

    Full Text Available ZnS/Si nanocables were synthesized via a simple two-step thermal evaporation method. The shape and diameter of the ZnS/Si nanocables can be controlled by adjusting the morphologies of the ZnS nanostructures (nanowire or nanoribbon obtained in the first step and the deposition time of the Si shell in the second step, respectively. Furthermore, we obtained polycrystalline Si nanotubes with different shapes and diameters by etching away the inner ZnS core. The as-prepared Si nanotubes were employed as SERS-active substrates, which exhibited a high sensitivity for the detection of R6G. The Si nanotubes also showed effective photocatalytic activity on the decomposition of R6G under the irradiation of visible light.

  14. Ser do tempo em Bergson

    OpenAIRE

    Coelho,Jonas Gonçalves

    2004-01-01

    O artigo apresenta a concepção bergsoniana de duração. Pretende-se mostrar que, segundo Bergson, o tempo dos filósofos e cientistas é um tempo fictício, um esquema espacial que oculta a natureza do tempo real, o qual não pode ser separado dos acontecimentos físicos e psicológicos. Para Bergson, o tempo real é sucessão, continuidade, mudança, memória e criação. El presente artículo trata de la concepción bergsoniana de duración. Pretendemos mostrar que, según Bergson, el tiempo de los filós...

  15. Ser do tempo em Bergson

    OpenAIRE

    Coelho, Jonas Gonçalves

    2004-01-01

    O artigo apresenta a concepção bergsoniana de duração. Pretende-se mostrar que, segundo Bergson, o tempo dos filósofos e cientistas é um tempo fictício, um esquema espacial que oculta a natureza do tempo real, o qual não pode ser separado dos acontecimentos físicos e psicológicos. Para Bergson, o tempo real é sucessão, continuidade, mudança, memória e criação. We considered Bergson's duration concept. We intended to show that, according to Bergson, the time of philosophers and scientists i...

  16. Ser marrano em Minas Colonial

    Directory of Open Access Journals (Sweden)

    Anita Novinsky

    2001-01-01

    Full Text Available Baseado em 57 Processos inéditos de marranos (cristãos-novos, conversos presos em Minas Gerais no século XVIII, este artigo procura mostrar seu papel na Idade de Ouro do Brasil. 64% deles eram mercadores e 23% eram mineiros. Pertenciam à classe média e raros eram os magnatas. Nenhum dele esteve envolvido no tráfico negreiro. Acusados do crime de judaísmo e de pertencerem a sociedades secretas, representaram 42% dos brasileiros condenados à morte. Ser marrano entre os portugueses no Brasil mais um sentimento e uma visão de mundo do que uma prática religiosa.Based on 57 unknown trials of marranos (new christians, conversos arrested by the Inquisition in Minas Gerais in the XVIII the century, this article shows their role in shapping the history of Minas Gerais. 64% of them were merchants na 23% were miners. Most of them belonged to a middle class and rare were those whit great fortunes. No one of them were engaged in slave trade. Acused of judaism and of participating in secret society the marranos of Minas represented 42% of the Brazilian burned at the stake. Being a marrano in Minas Gerais was not always being a crypto-new. Marranism in Brasil was a feeling and a approach to life.

  17. Prevalencia y evaluación de síntomas en enfermedad renal crónica avanzada

    Directory of Open Access Journals (Sweden)

    Daniel Gutiérrez Sánchez

    2015-09-01

    Full Text Available El paciente con enfermedad renal crónica avanzada (ERCA presenta una elevada carga de síntomas que contribuyen a un aumento del sufrimiento y disminuyen su calidad de vida. El uso de instrumentos de evaluación es esencial para el control de síntomas. El objetivo de esta revisión es obtener una visión contrastada de los instrumentos más usados para evaluar síntomas en ERCA, realizando una descripción de la prevalencia de síntomas en esta población. Método: Se realizó una revisión de la literatura publicada sobre estudios en los que se utilizara algún instrumento para medir la intensidad de varios síntomas en pacientes con ERCA. La búsqueda se realizó en Pubmed, Cochrane, SciELO, TESEO, PROQOLID y BiblioPRO. Los criterios de inclusión fueron: estudios realizados con pacientes en ERCA, que evaluaran la sintomatología con algún instrumento de medición de síntomas, y que además, indicaran la prevalencia de varios síntomas. Resultados: Los instrumentos identificados fueron el Memorial Symptom Assessment Scale Short Form(MSAS-SF, el Dialysis Symptom Index (DSI, el Edmonton Symptom Assessment System (ESAS y el Palliative care Outcome Scale-Symptoms Renal (POS-S RENAL. En pacientes adultos con ERCA sometidos a tratamiento renal sustitutivo con hemodiálisis y diálisis peritoneal, los síntomas más prevalentes fueron el cansancio, prurito, estreñimiento, anorexia, dolor, alteraciones del sueño, ansiedad, disnea, nauseas, piernas inquietas, y depresión. Éstos síntomas fueron similares en pacientes con manejo renal conservador, y presentaron un patrón común con la sintomatología de otras enfermedades avanzadas. Concluimos que existe necesidad de investigar sobre prevalencia y evaluación de síntomas en esta población, y que el uso sistemático de los instrumentos específicos de evaluación de síntomas como medida de resultados es fundamental.

  18. Calidad de vida y bienestar psicológico en pacientes adultos con enfermedad avanzada y en cuidado paliativo en Bogotá

    Directory of Open Access Journals (Sweden)

    Mónica María Novoa Gómez

    2008-01-01

    Full Text Available El presente estudio evaluó la calidad de vida y el bienestar psicológico de pacientes oncológicos con diagnóstico de enfermedad avanzada y que al momento de la evaluación se encontraban en cuidado paliativo en la ciudad de Bogotá. La muestra estuvo constituida por 83 personas mayores de edad de ambos sexos, con diversos tipos de enfermedad oncológica y con diagnóstico de enfermedad avanzada. Previa firma del consentimiento informado, los instrumentos que se aplicaron fueron un Registro de Datos Sociodemográficos, Índice de Bienestar Psicológico (Dupuy, 1984 SF36 (Medical Outcomes Trust, 1992 y el McMaster Quality of Life Scale (Sterkenburg, Woodward y King, 1996, los cuales están diseñados para la medición de la calidad de vida en pacientes con cáncer. Se analizaron los datos en función de variables sociodemográficas, tipo de tratamientos recibidos y tipo de enfermedad avanzada.

  19. Entre contener y ser contenido

    Directory of Open Access Journals (Sweden)

    Jorge Morales Meneses

    2016-08-01

    Full Text Available El presente artículo propone una nueva manera de entender los elementos comunes en la formación y el hacer del diseño y de la arquitectura, posibilitando un pensar común y un coactuar en diversas escalas de intervención, necesarias para el manejo de la complejidad del paisaje contemporáneo. La convicción de un pensar común entre ambas disciplinas permite explorar un marco filosófico que incluye a pensadores tan trascendentales como Aristóteles, Kant y Heidegger, estableciendo un orden de pensamiento que los relaciona y sitúa. En momentos en que el territorio está siendo visible y negativamente afectado por elementos no pensados o que fueron imaginados separadamente, este artículo propone una mirada que le dé sentido de totalidad a las acciones del diseño y de la arquitectura, como elementos que permanentemente se contienen en otros de diferente escala, pero que siempre están vinculados. Reconocer el paisaje físico y mental, tangible e intangible que contiene al diseño y a la arquitectura contribuirá a establecer un marco de acción donde todos los elementos construidos por el ser humano puedan tener un rol específico y una escala asumida, e intercomprenderse para mejor utilización de los recursos, disminuir el impacto ambiental y contribuir a un orden social mejor interpretado por los objetos, espacios y sus representaciones.

  20. Impacto de la salud: análisis longitudinal del empleo en edad media y avanzada en México

    Directory of Open Access Journals (Sweden)

    César GONZÁLEZ-GONZÁLEZ

    2014-01-01

    Full Text Available A partir de los datos longitudinales del Estudio Nacional sobre Salud y Envejecimiento en Méxi - co, se analiza la relación entre el estado de salud y la participación laboral de las personas de 50 años o más en México. Los resultados confirman que la salud, medida a través de las enfermeda - des crónicas y la dificultad para realizar actividades de la vida diaria, es un factor clave en la par - ticipación laboral. Se encuentran diferencias importantes por sexo, con hipertensión y diabetes con efectos sobre hombres y mujeres y enfermedad del corazón y embolia sólo en los hombres. Este artículo aporta evidencia concreta sobre la participación económica y señala la importancia de diseñar políticas públicas sobre la creación de empleos adecuados para la población en edad media y avanzada.

  1. Plasmonic nanostructures for bioanalytical applications of SERS

    Science.gov (United States)

    Kahraman, Mehmet; Wachsmann-Hogiu, Sebastian

    2016-03-01

    Surface-enhanced Raman scattering (SERS) is a potential analytical technique for the detection and identification of chemicals and biological molecules and structures in the close vicinity of metallic nanostructures. We present a novel method to fabricate tunable plasmonic nanostructures and perform a comprehensive structural and optical characterization of the structures. Spherical latex particles are uniformly deposited on glass slides and used as templates to obtain nanovoid structures on polydimethylsiloxane surfaces. The diameter and depth of the nanovoids are controlled by the size of the latex particles. The nanovoids are coated with a thin Ag layer for fabrication of uniform plasmonic nanostructures. Structural characterization of the surfaces is performed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Optical properties of these plasmonic nanostructures are evaluated via UV/Vis spectroscopy, and SERS. The sample preparation step is the key point to obtain strong and reproducible SERS spectra from the biological structures. When the colloidal suspension is used as a SERS substrate for the protein detection, the electrostatic interaction of the proteins with the nanoparticles is described by the nature of their charge status, which influences the aggregation properties such as the size and shape of the aggregates, which is critical for the SERS experiment. However, when the solid SERS substrates are fabricated, SERS signal of the proteins that are background free and independent of the protein charge. Pros and cons of using plasmonic nano colloids and nanostructures as SERS substrate will be discussed for label-free detection of proteins using SERS.

  2. Tratamiento ortodóntico en paciente con periodontits crónica avanzada generalizada: reporte de un caso

    Directory of Open Access Journals (Sweden)

    Iván Enrique Porto Cortés

    2016-01-01

    Full Text Available El tratamiento de ortodoncia es un procedimiento que busca corregir la maloclusión y mejorar la estética dental a través de fuerzas leves por periodos de tiempos largos o medianos, dicho tratamiento en pacientes periodontalmente comprometidos genera polémica debido a que la colocación de la aparatología puede incrementar la formacion de biopelicula y por ende agravar la periodontitis; también las fuerzas ejercidas podrían aumentar la reabsorción ósea. Sin embargo, en la actualidad se pueden encontrar estudios que confirman que el tratamiento de ortodoncia ayuda al periodonto enfermo gracias a los diferentes movimientos dentales que se producen durante éste; siempre y cuando el ortodoncista y periodoncista trabajen en conjunto, eduquen y motiven al paciente a cambiar sus hábitos de higiene bucal y sigan unos parámetros determinados. El objetivo principal del artículo es la presentación de un caso clínico en el que se realizó un tratamiento de ortodoncia a un paciente con periodontitis crónica avanzada generalizada y con relación canina clase III para de detener el avance de esta enfermedad, además para corregir la maloclusión y lograr una buena estética facial y dental. En conjunto con este tratamiento se realizaron procedimientos de mantenimiento periodontal tales como profilaxis dental, fase higiénica y enseñanza en higiene bucal. Los resultados del tratamiento se consideraron satisfactorios, se culminó sin pérdida dentaria, con oclusión en clase 1 de Angle, una buena estética facial y dental, un periodonto sano y un paciente educado en higiene bucal.

  3. Laboratorio Web SCORM de Control PID con Integración Avanzada

    Directory of Open Access Journals (Sweden)

    Ildefonso Ruano Ruano

    2016-10-01

    Full Text Available Resumen: Los laboratorios Web (WebLabs son recursos cada vez más utilizados en las carreras técnicas universitarias. Cuando se presentan integrados en un sistema de gestión de aprendizaje (LMS, Learning Management System se obtienen una serie de ventajas para alumnos y docentes entre las que destaca el hecho de mostrarse en un entorno conocido y la posibilidad de personalizar la experiencia gracias a la identificación de usuarios que realiza el LMS. Este trabajo muestra un WebLab sobre control Proporcional-Integral-Derivativo (PID, un contenido fundamental de las asignaturas de Automática que se encuentra en todos los grados de Ingeniería Industrial. Este WebLab ha sido desarrollado mediante una metodología innovadora con la que se obtiene un recurso de aprendizaje eficaz basado en un paquete SCORM (Shared Content Object Reference Model. SCORM es el estándar de contenidos de e-learning más utilizado y es compatible con la mayoría de los LMS del mercado, esto permite que el WebLab pueda ser reutilizado fácilmente en diferentes entornos LMS. El WebLab contiene un plan de aprendizaje que incluye una serie de recursos de utilidad docente como teoría de control PID, pruebas de evaluación, un laboratorio virtual de control PID de un motor de corriente continua y experimentos personalizados para cada alumno cuyos resultados son almacenados en el LMS. Este WebLab se ha presentado en el LMS institucional de la Universidad de Jaén a 340 alumnos de la asignatura “Automática Industrial” en el curso 2014-15. Los datos de uso han permitido realizar diversas evaluaciones que demuestran que los alumnos que lo han completado han obtenido un rendimiento excelente en el propio WebLab, han conseguido unos resultados muy superiores al resto de alumnos en la evaluación final de la asignatura y lo han valorado muy positivamente. También se ha demostrado la reusabilidad del WebLab en diferentes LMS

  4. Combinación de procesos de oxidación avanzada y procesos anaerobios para tratamiento de aguas residuales hospitalarias

    OpenAIRE

    , Carlos; Chaparro, Tatiana

    2014-01-01

    Las aguas residuales hospitalarias son una de las principalesfuentes de contaminantes emergentes (e.g. antibióticos,antiepilépticos, hormonas). Debido a la baja eficiencia de los procesos convencionales usados en las plantas de tratamiento de aguas residuales municipales, para eliminar la materia orgánica de este origen, combinar procesos de oxidación avanzada con tratamientos biológicos, surge como una alternativa para reducir el impacto en en el ambiente de estas aguas residuales. Con base ...

  5. Development of SERS active fibre sensors

    CERN Document Server

    Polwart, E

    2002-01-01

    Surface-enhanced Raman scattering (SERS) is sensitive and selective and when coupled with fibre-optics could potentially produce an effective chemical sensing system. This thesis concerns the development of a single-fibre-based sensor, with an integral SERS-active substrate. A number of different methods for the manufacture of SERS-active surfaces on glass substrates were investigated and compared. The immobilisation of metal nanoparticles on glass functionalised with (3-aminopropyl)trimethoxysilane emerged as a suitable approach for the production of sensors. Substrates prepared by this approach were characterised using UV-visible spectroscopy, electron microscopy and Raman mapping. It was found that exposure of substrates to laser radiation led to a decrease in the signal recorded from adsorbed analytes. This speed of the decrease was shown to depend on the analyte, and the exciting wavelength and power. SERS-active fibre sensors were produced by immobilisation of silver nanoparticles at the distal end of a...

  6. Single molecule SERS: Perspectives of analytical applications

    Czech Academy of Sciences Publication Activity Database

    Vlčková, B.; Pavel, I.; Sládková, M.; Šišková, K.; Šlouf, Miroslav

    834-836, - (2007), s. 42-47 ISSN 0022-2860. [European Congress on Molecular Spectroscopy /28./. Istanbul, 03.09.2006-08.09.2006] R&D Projects: GA ČR GA203/04/0688 Institutional research plan: CEZ:AV0Z40500505 Keywords : surface-enhanced Raman scattering (SERS) * surface-enhanced resonance Raman (SERRS) * single molecule SERS Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.486, year: 2007

  7. Chk1 phosphorylation at Ser286 and Ser301 occurs with both stalled DNA replication and damage checkpoint stimulation

    International Nuclear Information System (INIS)

    Ikegami, Yosuke; Goto, Hidemasa; Kiyono, Tohru; Enomoto, Masato; Kasahara, Kousuke; Tomono, Yasuko; Tozawa, Keiichi; Morita, Akimichi; Kohri, Kenjiro; Inagaki, Masaki

    2008-01-01

    We previously reported Chk1 to be phosphorylated at Ser286 and Ser301 by cyclin-dependent kinase (Cdk) 1 during mitosis [T. Shiromizu et al., Genes Cells 11 (2006) 477-485]. Here, we demonstrated that Chk1-Ser286 and -Ser301 phosphorylation also occurs in hydroxyurea (HU)-treated or ultraviolet (UV)-irradiated cells. Unlike the mitosis case, however, Chk1 was phosphorylated not only at Ser286 and Ser301 but also at Ser317 and Ser345 in the checkpoint response. Treatment with Cdk inhibitors diminished Chk1 phosphorylation at Ser286 and Ser301 but not at Ser317 and Ser345 with the latter. In vitro analyses revealed Ser286 and Ser301 on Chk1 to serve as two major phosphorylation sites for Cdk2. Immunoprecipitation analyses further demonstrated that Ser286/Ser301 and Ser317/Ser345 phosphorylation occur in the same Chk1 molecule during the checkpoint response. In addition, Ser286/Ser301 phosphorylation by Cdk2 was observed in Chk1 mutated to Ala at Ser317 and Ser345 (S317A/S345A), as well as Ser317/Ser345 phosphorylation by ATR was in S286A/S301A. Therefore, Chk1 phosphorylation in the checkpoint response is regulated not only by ATR but also by Cdk2.

  8. Conocer y ser en el paradigma constructivista

    Directory of Open Access Journals (Sweden)

    Jose Antonio Camargo Rodriguez

    2014-03-01

    Full Text Available Toda teoría acerca del aprendizaje se fundamenta en una interpretación del conocimiento, la cual se encuentra, a su vez, ligada a una cierta concepción de «ser». No será posible asimilar verdaderamente cualquiera de tales teorías si se ignoran, o no se consideran con el debido detenimiento, las ideas de conocer y «ser» que le sirven de base. Sc pone de presente que el constructivismo, en contraste con la teoría transmisionista de la enseñanza y el aprendizaje, predominante en la pedagogía tradicional, tiene su fundamento en la interpretación según la cual el conocer es una actividad humana en la que, a medida quo conoce, el hombre construye el «ser». Antes de todo conocimiento, las cosas no tienen un «ser»; están ahí, pero no se sabe lo que son. El «ser», quo constituye el objeto de todo conocer, aquello que el sujeto persigue a través de su conocimiento, no toes dada de antemano, ni le viene de fuera, sino quo es una elaboración quo el mismo realiza a través de su actividad cognoscitiva, un contenido de su propia conciencia. Hay, pues, una cierta paradoja entre las ideas de conocer y «ser» que sirven de fundamento al constructivismo, cuya reflexión se propone en aras de ganar una mejor comprensión, de encontrarle a este paradigma un sentido más allá de la pedagogía y la didáctica.

  9. and Au nanoparticles for SERS applications

    Directory of Open Access Journals (Sweden)

    Fazio Enza

    2018-01-01

    Full Text Available The morphological and optical properties of noble metal nanoparticles prepared by picosecond laser generated plasmas in water were investigated. First, the ablation efficiency was maximized searching the optimal focusing conditions. The nanoparticle size, measured by Scanning Transmission Electron Microscopy, strongly depends on the laser fluence, keeping fixed the other deposition parameters such as the target to scanner objective distance and laser repetition frequency. STEM images indicate narrow gradients of NP sizes. Hence the optimization of ablation parameters favours a fine tuning of nanoparticles. UV-Visible spectroscopy helped to determine the appropriate laser wavelength to resonantly excite the localized surface plasmon to carry out Surface Enhanced Raman Scattering (SERS measurements. The SERS activity of Ag and Au substrates, obtained spraying the colloids synthesized in water, was tested using crystal violet as a probe molecule. The good SERS performance, observed at excitation wavelength 785 nm, is attributed to aggregation phenomena of nanoparticles sprayed on the support.

  10. Plasmonic SERS biosensing nanochips for DNA detection.

    Science.gov (United States)

    Ngo, Hoan T; Wang, Hsin-Neng; Fales, Andrew M; Vo-Dinh, Tuan

    2016-03-01

    The development of rapid, cost-effective DNA detection methods for molecular diagnostics at the point-of-care (POC) has been receiving increasing interest. This article reviews several DNA detection techniques based on plasmonic-active nanochip platforms developed in our laboratory over the last 5 years, including the molecular sentinel-on-chip (MSC), the multiplex MSC, and the inverse molecular sentinel-on-chip (iMS-on-Chip). DNA probes were used as the recognition elements, and surface-enhanced Raman scattering (SERS) was used as the signal detection method. Sensing mechanisms were based on hybridization of target sequences and DNA probes, resulting in a distance change between SERS reporters and the nanochip's plasmonic-active surface. As the field intensity of the surface plasmon decays exponentially as a function of distance, the distance change in turn affects SERS signal intensity, thus indicating the presence and capture of the target sequences. Our techniques were single-step DNA detection techniques. Target sequences were detected by simple delivery of sample solutions onto DNA probe-functionalized nanochips and measuring the SERS signal after appropriate incubation times. Target sequence labeling or washing to remove unreacted components was not required, making the techniques simple, easy-to-use, and cost-effective. The usefulness of the nanochip platform-based techniques for medical diagnostics was illustrated by the detection of host genetic biomarkers for respiratory viral infection and of the dengue virus gene.

  11. SERS Nanosensors for in Vivo Glucose Sensing

    Science.gov (United States)

    2017-09-01

    monitoring, medical device W81XWH-16-1-0376 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF...SERS, Raman scattering, spectroscopy, hydrogel, microneedle array, continuous glucose monitoring, medical device 3. ACCOMPLISHMENTS Major...stronger particle-particle interaction. Therefore, the electrostatic attraction between particles must be overcome to bring the particles closer to the

  12. Resultado de las quemaduras tratadas mediante cultivo de células epidérmicas autólogas : reglamentos e implicaciones para ensayos clínicos internacionales con Productos de Terapia Avanzada

    NARCIS (Netherlands)

    Middelkoop, E.; Gardien, K.L.M.; Brouwer, K.M.; Waaijman, T.; Uhlrich, M.M.W.; Gibbs, S.; Ulrich, M.M.W.

    2016-01-01

    Introducción. Los Productos de Terapia Avanzada (ATMPs) son considerados el siguiente paso para mejorar la evolución de las quemaduras. Sin embargo, existen serios obstáculos para su aplicabilidad con respecto al reglamento internacional vigente. Aparte de las exigencias reglamentarias para los

  13. Edad avanzada y factores de riesgo para infarto agudo de miocardio Risk factors for acute myocardial infarction in the elderly

    Directory of Open Access Journals (Sweden)

    M. A. Ciruzzi

    2002-12-01

    Full Text Available Este estudio caso-control analizó en los sujetos añosos el rol de los factores de riesgo coronario en el desarrollo del infarto agudo de miocardio (IAM, estableció la naturaleza de esta asociación y el grado de riesgo. Los datos fueron obtenidos en una investigación que incluyó 1060 casos y 1071 controles, realizada en 35 unidades coronarias de centros médicos de Argentina entre noviembre de 1991 y agosto de 1994. Nuestro análisis se basó en la información de los sujetos mayores de 65 años. Los casos fueron 427 pacientes con un primer IAM. Los controles fueron 396 sujetos sin evidencias clinicas de enfermedad cardiovascular, seleccionados en los mismos centros que los casos. Los Odds Ratios (OR y su intervalo de confianza del 95% (IC 95% se obtuvieron mediante un análisis de regresión logística, incluyendo variables como la edad, educación, clase social, tabaquismo, antecedente de diabetes o hipertensión arterial, índice de masa corporal e historia familiar de enfermedad coronaria. Los factores de riesgo relacionados independientemente con IAM fueron los siguientes: hipercolesterolemia (colesterol sérico > 240 mg/dl: OR=1.76 (IC 95%: 1.25-2.49, tabaquismo: OR=1.6 (IC 95%: 1.06-2.4, hipertensión arterial: OR=2.05 (IC 95%: 1.51-2.73, diabetes OR=1.71 (IC 95%: 1.12-2.70, historia de un familiar con enfermedad coronaria: OR=1.36 (IC 95%: 0.93-1.97 y de dos o más familiares: OR=2.63 (IC 95%: 1.21-5.71. Este estudio, confirma en los sujetos de edad avanzada la importancia de la hipercolesterolemia, del tabaquismo, la hipertesión arterial, la diabetes y la historia familiar de enfermedad coronaria como factores de riesgo de IAMThis case-control study, analized the role of coronary risk factors in acute myocardial infarction (AMI in the elderly, and established the nature of this association and the degree of risk. Data were derived from an investigation (1060 cases and 1071 controls conducted in 35 coronary care units from clinical

  14. Nanocomposites as probes for biodetection by SERS =

    Science.gov (United States)

    Cruz, Sandra Maria Alves da

    The present work aimed to explore the potential of new nanocomposites based on carbon nanostructures and metal nanoparticles for the detection of biomolecules through surface enhanced Raman scattering (SERS). In a first step, polyvinyl alcohol composites were prepared incorporating silver nanoparticles by two different reduction procedures. At first without introduction of carbon nanostructures. These composites showed good results for the SERS identification of nucleic acids. Next, the synthesis and characterization of graphene oxide was studied to be used in the preparation of silver and gold nanocomposites. The reduction of this nanomaterial with different chemical agents was explored, since its reduction degree may be a determinant factor for the application envisaged (biomolecules interaction). The preparation of the nanocomposites with silver and gold was performed with different reducing agents. The SERS activity of these new nanocomposites was then explored in the presence of different analytes, varying the experimental conditions for Raman spectra acquisition. It was interesting to verify that the silver containing nanocomposites presented the particularity to intensify the graphene D and G bands. It is also important to highlight that a new eco-friendly reducing agent was tested for the synthesis of the graphene oxide composites, an Eucalyptus Globulus extract. Other variable introduced was the preparation of gold nanostars synthesized with hydroxylamine in the presence of graphene oxide, which allowed the preparation of a new nanocomposite with SERS potential. Fibrous membranes were also prepared by electrospinning with the aim to prepare SERS supports with adequate topography and porosity for the formation of nanoparticles agglomerates for the creation of the so-called hot-spots and also to allow the penetration of the analyte molecules. The polymers polyvinyl alcohol and polyacrylonitrile were selected for electrospinning. Using this technique

  15. Educación sanitaria al paciente con enfermedad renal crónica avanzada: ¿existe evidencia de su utilidad?

    Directory of Open Access Journals (Sweden)

    Francisco Javier Bonilla León

    Full Text Available Introducción: La enfermedad renal crónica se ha convertido en un grave problema sanitario por su elevada incidencia y prevalencia e importante morbimortalidad y coste asistencial. Dada la gravedad del problema, es necesaria una detección precoz de la enfermedad y un tratamiento adecuado de las comorbilidades asociadas. El manejo, por parte del paciente de su tratamiento, dieta, medidas higiénicas, etc, puede prevenir o reducir esta complicación, para lo cual es fundamental la educación sanitaria. Objetivo: Conocer la producción científica acerca de la utilidad de la educación sanitaria en pacientes con enfermedad renal crónica avanzada. Métodos: Se trata de una revisión bibliográfica para la que se realizó una búsqueda en las bases de datos de PubMed, Scielo, Science Direct y Google Académico. Se incluyeron artículos científicos escritos en inglés y español. Se analizaron los artículos que trataban la educación sanitaria de pacientes con enfermedad renal crónica avanzada en consultas prediálisis. Resultados: Tras el análisis de los 24 artículos seleccionados, podemos decir que la educación sanitaria ofrece beneficios tangibles al enfermo renal. Entre las variables desarrolladas, cabe destacar la fuerte implicación que la educación tiene en la elección de modalidad de tratamiento y como se considera un factor asociado a la supervivencia. Además se relaciona con un 17% menos de riesgo de ingresar en el hospital, un inicio programado de la diálisis, reduce la morbilidad, aumenta los valores de parámetros bioquímicos positivos y da más seguridad al paciente para afrontar el manejo de su enfermedad. Conclusiones: La educación sanitaria es una herramienta de suma importancia en el tratamiento de los pacientes con enfermedad renal crónica avanzada, y se debe ofrecer en el marco de una consulta prediálisis formada por un equipo multidisciplinar, en el que enfermería tiene un rol activo muy importante.

  16. DISEÑO Y APLICACIÓN DE UN INSTRUMENTO PARA LA EVALUACIÓN DEL CONTEXTO DE APRENDIZAJE EN ORGANIZACIONES DE AVANZADA DEL TERRITORIO DE CIENFUEGOS/ DESIGN AND IMPLEMENTATION OF A TOOL FOR THE EVALUATION OF LEARNING CONTEXT IN ADVANCED ORGANIZATIONS

    Directory of Open Access Journals (Sweden)

    Dainelis Curbelo-Martínez

    2011-06-01

    Full Text Available

    El trabajo que se presenta está encaminado a diseñar un instrumento para evaluar el Contexto de Aprendizaje en organizaciones de avanzada del Sistema Empresarial cubano, utilizando un análisis integrador del conjunto de factores que lo condicionan y herramientas que lo facilitan. Finalmente se calcula un indicador que, de forma cuantitativa, intenta visualizar los resultados de la investigación. Para la evaluación del Contexto de Aprendizaje en este estudio se seleccionan como unidades de análisis 45 organizaciones consideradas de avanzada, por encontrarse entre las que desarrollan el proceso de Perfeccionamiento Empresarial y ser representativas de sectores que poseen una importante incidencia en el territorio de Cienfuegos. La fiabilidad y validez del instrumento diseñado permiten establecer criterios sobre el constructo estudiado (Contexto de Aprendizaje, lo que a través del análisis factorial se corrobora. Los resultados de la aplicación del instrumento diseñado revelan que el Contexto de Aprendizaje es favorable para la mayoría de las empresas analizadas y demuestran la necesidad de continuar investigaciones en este campo, en especial en lo referente a la medición.

    Abstract

    The investigation presented is aimed to design a tool to evaluate the Learning Context in advanced organizations of Cuban Managerial System using an integrating analysis of all conditioning factors and tools that facilitate it. Finally, an indicator, which in a quantitatively way attempts to visualize the results of the investigation is calculated. For the evaluation of Learning Context in this investigation, there are selected as analysis units 45 organizations considered as advanced ones, since they are developing the Managerial Improvement process and they are representative of sectors with a significant impact in Cienfuegos. The reliability and validity of the designed tool allow to establish criteria about the studied

  17. Sistemas de recuperación e internet: Metadescripción, procesamiento, webcrawling, técnicas de consulta avanzada, hacking documental y posicionamiento web

    OpenAIRE

    Blázquez Ochando, Manuel

    2013-01-01

    La búsqueda y recuperación en Internet consta de métodos y técnicas complementarios a los empleados en el desarrollo de algoritmos en los motores de búsqueda, véase blog de la asignatura Técnicas Avanzadas de Recuperación de Información. En este sentido, se estudiarán con detenimiento todos los metadatos Dublin Core básicos y extendidos, para su aplicación en páginas web en forma de etiquetas embebidas dentro del código fuente de una página web y en formato RDF. Tales sistemas de meta-descrip...

  18. Aplicación de técnicas de diagnóstico por imagen avanzadas en el estudio de la cabeza del caballo

    OpenAIRE

    Manso Díaz, Gabriel

    2015-01-01

    La cabeza del caballo es una muy compleja anatómicamente lo que dificulta su diagnóstico. Por tanto las técnicas de diagnóstico por imagen son fundamentales.Las técnicas de diagnóstico por imagen avanzadas, resonancia magnética o RM y tomografía computarizada o TC, generan imágenes tomográficas, evitando la superposición de estructuras. La TC se basa en la rotación de un generador de rayos x y una matriz de detectores alrededor del paciente, mientras que la RM se basa en la excitación de teji...

  19. Influencia de la consulta de enfermería de enfermedad renal crónica avanzada en pacientes que inician tratamiento renal sustitutivo

    Directory of Open Access Journals (Sweden)

    Ana Rebollo Rubio

    2014-12-01

    Full Text Available La remisión precoz del paciente con enfermedad renal crónica avanzada al especialista y una atención nefrológica integrada y especializada en la etapa prediálisis, proporcionada por un equipo multidisciplinar, ha demostrado tener importantes beneficios sobre pacientes en fase avanzada de la enfermedad renal que inician tratamiento renal sustitutivo. Objetivo: determinar si existe riesgo de alteraciones a nivel físico, psicológico o de la calidad de vida en pacientes que inician terapia sustitutiva renal en función de si han tenido seguimiento nefrológico multidisciplinar en la etapa prediálisis. Material y métodos: estudio observacional trasversal analítico sobre una muestra de 90 pacientes que inician terapia sustitutiva renal. Resultados: El 86,5% de los pacientes estudiados fue seguido por el nefrólogo en la etapa prediálisis, solo el 37,8% de los pacientes fue atendido por la enfermera. El 27,8% de los pacientes mostraban elevados niveles de ansiedad al iniciar diálisis. No se encontraron diferencias en la calidad de vida relacionado con la salud entre pacientes seguidos o no por la enfermera en la etapa prediálisis. Conclusiones: Un porcentaje muy bajo de pacientes son seguidos en la consulta de enfermería prediálisis, no existiendo diferencias significativas en la calidad de vida relacionada con la salud entre ambos grupos. Si se encontraron diferencias significativas en cuanto a la ansiedad; el grupo de pacientes atendidos por la enfermera en la etapa prediálisis presentan mayores niveles de ansiedad que los no atendidos.

  20. La cultura del horror en las sociedades avanzadas: de la sociedad centrípeta a la sociedad centrífuga.

    Directory of Open Access Journals (Sweden)

    EDUARDO BERICAT ALASTUEY

    2005-01-01

    Full Text Available El presente artículo expone los principales resultados de una investigación realizada con el objeto de analizar el papel que cumplen las emociones colectivas en el mantenimiento del orden social. En concreto, trata de explicar el hecho de que las noticias más importantes que aparecen en los medios de comunicación sean noticias de horror, es decir, noticias en las que la muerte siempre aparece en el primer plano de la escena. Los informativos de los medios de comunicación expresan y fomentan la cultura del horror característica de nuestras sociedades avanzadas. Ahora bien, para entender esta cultura es preciso determinar previamente la naturaleza emocional del horror, así como establecer una definición sociológica de este sentimiento. El horror es una emoción compleja compuesta por sentimientos de terror, de asco y de conmoción. El horror, sociológicamente, puede entenderse como "la emoción mediante la que un orden social señala sus límites más extremos". El estudio concluye señalando que existen dos modos alternativos de mantener el orden y la cohesión en el seno de un sistema social. El primer modo de legitimación, característico de las sociedades centrípetas, funciona mediante la gran potencia atractiva que ejerce sobre el campo social un núcleo central de valores sociales positivos. El segundo, característico de las sociedades centrífugas, funciona mediante la gran potencia repulsiva que ejercen sobre el campo social las transgresiones flagrantes del orden moral. El modo típico en el que las sociedades centrífugas regulan el orden social explica la cultura del horror característica de nuestras sociedades avanzadas.

  1. Suplementación de ácido fólico con o sin vitamina B12 para prevenir el deterioro cognitivo en sujetos de edad avanzada: análisis crítico de la literatura

    Directory of Open Access Journals (Sweden)

    Raúl Alberto Aguilera-Eguía

    2016-01-01

    Full Text Available La demencia es un síndrome que interfiere en funciones corticales de la persona, posiblemente causado por déficit de vitamina B12. Se cree que la suplementación de ácido fólico con o sin vitamina B12 puede prevenir el deterioro cognitivo o disminuirlo en sujetos sanos de edad avanzada que presentan altos niveles de homocisteína en plasma. El objetivo de este trabajo fue comprobar la validez y aplicabilidad de los resultados con respecto a la efectividad de la suplementación de ácido fólico con o sin vitamina B12 en sujetos de edad avanzada con niveles elevados de homocisteína y responder al siguiente interrogante: en sujetos sanos de edad avanzada con niveles altos de homocisteína, ¿puede la suplementación de ácido fólico con o sin vitamina B12 prevenir o disminuir el deterioro de las funciones cognitivas? Se analizó la revisión sistemática Cochrane “Ácido fólico con o sin vitamina B12 para la prevención y el tratamiento de personas sanas de edad avanzada con demencia”, de Malouf et al. (2008. La administración de ácido fólico por tres años con o sin vitamina B12 en sujetos sanos de edad avanzada con un alto nivel de homocisteína en plasma, podrían mejorar significativamente la función cognitiva global, presentando una diferencia media ponderada de 0,05 (IC 95%; 0,004 a 0,096. A pesar de las limitaciones metodológicas y la escasa cantidad de estudios primarios incluidos en la revisión sistemática analizada, encontramos razonable el uso de ácido fólico con o sin vitamina B12 para mejorar la función cognitiva en personas sanas de edad avanzada con niveles elevados de homocisteína.

  2. Hollow plasmonic antennas for broadband SERS spectroscopy

    Directory of Open Access Journals (Sweden)

    Gabriele C. Messina

    2015-02-01

    Full Text Available The chemical environment of cells is an extremely complex and multifaceted system that includes many types of proteins, lipids, nucleic acids and various other components. With the final aim of studying these components in detail, we have developed multiband plasmonic antennas, which are suitable for highly sensitive surface enhanced Raman spectroscopy (SERS and are activated by a wide range of excitation wavelengths. The three-dimensional hollow nanoantennas were produced on an optical resist by a secondary electron lithography approach, generated by fast ion-beam milling on the polymer and then covered with silver in order to obtain plasmonic functionalities. The optical properties of these structures have been studied through finite element analysis simulations that demonstrated the presence of broadband absorption and multiband enhancement due to the unusual geometry of the antennas. The enhancement was confirmed by SERS measurements, which showed a large enhancement of the vibrational features both in the case of resonant excitation and out-of-resonance excitation. Such characteristics indicate that these structures are potential candidates for plasmonic enhancers in multifunctional opto-electronic biosensors.

  3. PROTOTIPO PARA EL ANÁLISIS DEL RENDIMIENTO EN EL TRÁFICO DE UN SERVICIO BROADCAST UTILIZANDO LOS PROTOCOLOS HTTP Y RTP SOBRE IPV6 EN UNA RED ACADÉMICA DE TECNOLOGÍA AVANZADA

    Directory of Open Access Journals (Sweden)

    Roberto Ferro

    2011-08-01

    Full Text Available En el presente artículo se condensan los resultados obtenidos de la implementación y modelado de un Prototipo de Servicio Streaming sobre el Sistema Operativo Fedora 13 con el Programa VLC en la Red de Investigación y  Tecnología Avanzada de la Universidad Distrital RITA-UD sobre IPV6 utilizando como cliente la Universidad Minuto de Dios vía RUMBO mediante un Tunel 6a4.

  4. Será a pobreza terrorista?

    OpenAIRE

    Santos, João Paulo

    2006-01-01

    A temática deste artigo é o MST e o ambiente que o influencia e sobre o qual também exerce influência. O resultado é que o Movimento, antes unanimemente reconhecido como necessário e virtuoso, é hoje visto com todas as ressalvas senão com hostilidade pela classe média urbana. E, mesmo com o reconhecimento do STJ da legitimidade de suas ocupações de latifúndios, por ser "direito reclamar a implantação da reforma agrária" e "legítima a pressão aos órgãos competentes para que aconteça" (Habea...

  5. euro a ser una moneda internacional

    Directory of Open Access Journals (Sweden)

    María Hortensia Lacayo Ojeda

    2001-01-01

    Full Text Available En este trabajo se estudia cuáles son los principales factores económicos y financieros que llevan al euro, la nueva moneda común europea, a ser una moneda internacional junto al dólar y al yen. Entre dichos factores se encuentran, en primer lugar, el respaldo económico de los doce países de la Unión Económica y Monetaria medido a través de su importancia demográfica, su producto interno bruto (PIB y su grado de apertura comercial; en segundo lugar, la dimensión financiera de la zona euro en lo referente a las inversiones realizadas en la moneda europea, su utilización como moneda de reserva y como moneda de intercambio; en tercer término, la confianza que inspire el euro a los actores económicos

  6. Ser lo mismo, ser diferente: contra la masificación

    OpenAIRE

    Saldarriaga Roa, Alberto

    2005-01-01

    La sociedad moderna se ha configurado, en los dos últimos siglos, como una sociedad de masas. Esto parece ser una condición sine qua non de su estructura y operatividad. La masificación se manifiesta no sólo en el comportamiento social sino también en el

  7. D-Ser-containing humanin shows promotion of fibril formation.

    Science.gov (United States)

    Hayashi, Kanehiro; Sasabe, Jumpei; Chiba, Tomohiro; Aiso, Sadakazu; Utsunomiya-Tate, Naoko

    2012-06-01

    Humanin (HN), a peptide of 24 amino acid residues, suppresses the neuronal cell death that is induced by the gene products of Alzheimer's disease. HN contains two Ser residues at positions 7 and 14. Because the proportion of D-Ser isomerized from L-Ser in proteins appears to increase as cellular organs age, we explored the structural effects of the isomerization of each Ser residue in HN. By using a thioflavin-T assay to detect fibril formation, we found that an HN derivative that contained two isomerized D-Ser residues had a greater tendency to form fibrils than did wild-type HN or HNs containing single D-Ser residues. A previous report showed that HN containing two D-Ser residues exerts neuroprotective activity. Our data, therefore, suggest that the fibril formation by HN that contains two D-Ser residues may promote HN neuroprotective activity.

  8. O Talco deve ser utilizado para Pleurodese

    Directory of Open Access Journals (Sweden)

    Steven A. Sahn

    2001-03-01

    Full Text Available RESUMO: A pleurodese està recomendada nos den·ames pleurais malignos quando o tumor não é sensível à quimioterapia. Aprcsenta taxas de sucesso vari:lveis em parte justificadas pelos diferentes agentes e doses utilizadas, a selecção de doentes eo tipo de técnica aplicada. O talco parece ser o agente mais efi caz de pleurodese.Steven Sahn defende que o talco deve ser utilizado para pleurodese, apoiando a sua opini ao em diferentes factores:Mecanisme da pleurodese para talcagcm - o talco após contacto com as células mesoteliais promove um influxo de neutrófil os IL8 mediadus e posterior acumulação de macrófagos, diminuiçãa actividade fibrinolftica e aumento do factor de crescimento dos fi broblastos. Quando o tumor reveste uma grande area de mesotclio, a pleurodese não é tao eficaz.Eficácia - uma revisão da li teratura inglesa de I966 a 1994 constatou que u talco foi o agente mais eficaz de pleurodese, cum uma taxa de sucesso de 93%, comparada cum a da tetraciclina de 67 %, doxicicli na de 72% e bleomicina de 54%. Outras séries reve1aram uma taxa de sucesso do talco sempre superior a 91 %.Custo - o talco é pouco dispendioso e se apl icado em suspensao (“slutTy” por tubo de toracostomia ainda reduz mais os custos inerentes a uma toracoscopia 4uando se utiliza o talco em pó, aprescntando cstas duas tecnicas, taxas ue eticacia scmelhantes. Reacçãoes Adversas Minor e Major Agudas- a toracalgia e a febre são OS efcitos adversos mains frequcntes, frequcntes de todos os agentes de pleurudese. A toracalgia surge em 7% dos doentcs submetiuos a plcurodesc com talco, em 28% com a bleomicina c 40% com a dox iciclina. A tetraciclina provoca geralmente wracalgia grave. A febre surge entre I6 a 69% após talcagem não ultrapassando as 72 horas.As reacçãoes adversas graves sao raras e incluern o cmpiema. arritmia cardfaca e insufcicncia rcspiratória. Se o talco

  9. Stabilization of alanine substituted p53 protein at Ser15, Thr18, and Ser20 in response to ionizing radiation

    International Nuclear Information System (INIS)

    Yamauchi, Motohiro; Suzuki, Keiji; Kodama, Seiji; Watanabe, Masami

    2004-01-01

    Phosphorylation of p53 at Ser15, Thr18, and Ser20 has been thought to be important for p53 stabilization in response to ionizing radiation. In the present study, we examined the X-ray-induced stabilization of Ala-substituted p53 protein at Ser15, Thr18, and Ser20, whose gene expression was controlled under an ecdyson-inducible promoter. We found that all single-, double-, or triple-Ala-substituted p53 at Ser15, Yhr18, and Ser20 were accumulated in the nucleus similarly to wild-type p53 after X-irradiation. These results indicate that the phosphorylation of p53 at Ser15, Thr18, and Ser20 is not necessarily needed for p53 stabilization in response to ionizing radiation

  10. Depression in late life: a hidden public health problem for Mexico? Depresión en la edad avanzada: ¿problema oculto de salud pública para México?

    Directory of Open Access Journals (Sweden)

    Fernando A. Wagner

    1999-05-01

    requiere más investigación acerca de factores de riesgo y protección para la depresión, ya que ello puede dar la pauta para establecer áreas de intervención. Atender la depresión entre las personas de edad avanzada puede contribuir significativamente a reducir costos de atención en salud, disminuir la discapacidad, la morbilidad y la mortalidad. Esto generaría importantes ahorros y liberaría recursos que podrían ser dedicados a la atención de otras necesidades de salud.

  11. MODOS DE SER DA JUVENTUDE OCIDENTAL

    Directory of Open Access Journals (Sweden)

    Prof. Dr. Luiz Antônio Dias

    2015-09-01

    Full Text Available O presente artigo é resultado de investigações ainda em andamento no Grupo de Pesquisa “Culturas juvenis, consumo e mobilidade urbana na contemporaneidade”, iniciadas em 2013 junto ao Programa de Mestrado Interdisciplinar em Ciências Humanas da Universidade de Santo Amaro (UNISA. A pesquisa dedica-se a entender, entre outras reflexões, o percurso dos jovens na sociedade contemporânea e as contribuições que eles trouxeram para repensar o espaço urbano. Nesse estudo buscamos localizar no espaço e no tempo em quais condições históricas o sentimento de juventude apareceu para a sociedade. Em seguida, fazemos um minucioso levantamento da trajetória dessa nova categoria social nos mais diferentes períodos da história contemporânea. Chegamos, assim, ao século XX, momento em que as reuniões juvenis deixam de ser fatos isolados e adquirem conotações de manifestações verdadeiramente sociais. Ainda nessa perspectiva de análise, buscamos compreender as similitudes, aproximações e distanciamentos do movimento punk com seus congêneres do passado.

  12. Paraplejia: pasado y futuro del ser

    Directory of Open Access Journals (Sweden)

    María Elisa Moreno-Fergusson

    Full Text Available El propósito del artículo es presentar una síntesis de la literatura publicada entre 1988 y 2008 sobre los cambios en la corporalidad de las personas con paraplejia secundaria a un trauma raquimedular y su relevancia para el cuidado de enfermería. La revisión incluyó 22 estudios cualitativos, 5 cuantitativos y 20 piezas documentales, publicadas por profesionales de la salud y de las ciencias humanas. Los resultados permiten concluir que las secuelas del trauma raquimedular causan dependencia, alteran la imagen corporal, la interacción social, el sentido de coherencia del ser y la corporalidad. Con el tiempo, estas personas, re-conocen su "nuevo cuerpo" y construyen una nueva corporalidad, proceso que aún no ha sido descrito y que se considera fundamental para el cuidado de enfermería, encaminado a ayudar a las personas con este tipo de lesión para lidiar con las dificultades cotidianas.

  13. Libertas que serás enfermagem

    Directory of Open Access Journals (Sweden)

    Mary Anne Fontenele Martins

    1998-09-01

    Full Text Available O título deste ensaio nos faz lembrar a Inconfidência Mineira, que teve como líder José Joaquim da Silva Xavier, o Tiradentes, sendo um movimento que ansiava por liberdade, assim como a enfermagem que, ao longo dos anos, vem construindo sua história e caminhando em busca de sua autonomia. A presente pesquisa tem como objetivo investigar os caminhos percorridos pela enfermagem, enquanto ciência na busca de sua autonomia, e refletir sobre a atuação do enfermeiro enquanto profissional criativo e autônomo. Estudo respaldado no materialismo histórico e dialético, realizado no período de maio a agosto de 1997 com enfermeiras do Estado do Ceará, que estão envolvidas com o processo histórico da profissão. Os resultados deram origem a uma categoria central, prática profissional e outras três: autonomia, criatividade e disposição para enfrentar desafios, que favoreceram uma melhor compreensão dos caminhos já trilhados pela enfermagem, além de nos permitir entender que o enfermeiro pode ser autônomo e livre.

  14. Llegar a ser Simone de Beauvoir

    Directory of Open Access Journals (Sweden)

    Nora Levinton Dolman

    2009-01-01

    Full Text Available A la manera de un Psicoanálisis aplicado a la obra de Simone de Beauvoir se señalan algunos aspectos cruciales que reflejan cómo se va configurando la vida y el pensamiento de una mujer que encarnó, para muchas de nosotras, un modelo de identificación. Su trabajo es en este sentido un espejo y una valiosa muestra de la naturaleza proyectiva de muchos de sus enunciados, donde a partir de su irreemplazable experiencia Simone arriba a conclusiones en las que podemos seguir el rastro de sus vivencias personales. En el contexto singular de su historia personal y en cómo es relatada. Al exponer su vida en sus libros y en numerosas entrevistas concedidas a distintos medios, ha dado lugar a que surgieran diferentes interpretaciones, por lo tanto a que sus palabras y argumentos puedan, como en este artículo, ser utilizados, contrastados entre sí y sometidos a exploración.

  15. Batch fabrication of disposable screen printed SERS arrays.

    Science.gov (United States)

    Qu, Lu-Lu; Li, Da-Wei; Xue, Jin-Qun; Zhai, Wen-Lei; Fossey, John S; Long, Yi-Tao

    2012-03-07

    A novel facile method of fabricating disposable and highly reproducible surface-enhanced Raman spectroscopy (SERS) arrays using screen printing was explored. The screen printing ink containing silver nanoparticles was prepared and printed on supporting materials by a screen printing process to fabricate SERS arrays (6 × 10 printed spots) in large batches. The fabrication conditions, SERS performance and application of these arrays were systematically investigated, and a detection limit of 1.6 × 10(-13) M for rhodamine 6G could be achieved. Moreover, the screen printed SERS arrays exhibited high reproducibility and stability, the spot-to-spot SERS signals showed that the intensity variation was less than 10% and SERS performance could be maintained over 12 weeks. Portable high-throughput analysis of biological samples was accomplished using these disposable screen printed SERS arrays.

  16. Instaurando maneiras de ser, conhecer e interpretar

    Directory of Open Access Journals (Sweden)

    Maria Stephanou

    1998-01-01

    Full Text Available O artigo propõe a discussão e a problematização do tema "currículo e história". Na primeira parte explicita os fundamentos propostos para a abordagem, as concepções de currículo e história. Na segunda, privilegia as indicações de autores e a experiência pessoal para: a caracterizar o que têm sido os currículos e o ensino de história, particularmente no ensino fundamental, comentan-do suas implicações; b examinar alternativas e encaminhamentos propostos pelos debates da atualidade. Sugere que a aprendizagem de conteúdos históricos na escola, para além da mera aquisição de informações, implica a produção ativa de subjetividades, ou maneiras de ser, conhecer e interpretar o mundo e a si próprio.This article proposes to discuses and to question the theme "curriculum & history". On first part, it explains the fundaments proposed to the dissertation, the conception of curriculum & history. On the second, it grants privilege upon authors remarks and personal experience for purpose to: a characterize what were the curricular activities and the teaching of history, inside primary school particularly, with comments about its implications. b examine alternatives and forwarding proposed by present debates. It suggests that in the school the apprenticeship around historical contents, other than a pure acquisition of information, implies and actives production of subjectivities or manners of being, knowing and interpreting the world and oneself.

  17. Reassessing SERS enhancement factors: using thermodynamics to drive substrate design.

    Science.gov (United States)

    Guicheteau, J A; Tripathi, A; Emmons, E D; Christesen, S D; Fountain, Augustus W

    2017-12-04

    Over the past 40 years fundamental and application research into Surface-Enhanced Raman Scattering (SERS) has been explored by academia, industry, and government laboratories. To date however, SERS has achieved little commercial success as an analytical technique. Researchers are tackling a variety of paths to help break through the commercial barrier by addressing the reproducibility in both the SERS substrates and SERS signals as well as continuing to explore the underlying mechanisms. To this end, investigators use a variety of methodologies, typically studying strongly binding analytes such as aromatic thiols and azarenes, and report SERS enhancement factor calculations. However a drawback of the traditional SERS enhancement factor calculation is that it does not yield enough information to understand substrate reproducibility, application potential with another analyte, or the driving factors behind the molecule-metal interaction. Our work at the US Army Edgewood Chemical Biological Center has focused on these questions and we have shown that thermodynamic principles play a key role in the SERS response and are an essential factor in future designs of substrates and applications. This work will discuss the advantages and disadvantages of various experimental techniques used to report SERS enhancement with planar SERS substrates and present our alternative SERS enhancement value. We will report on three types of analysis scenarios that all yield different information concerning the effectiveness of the SERS substrate, practical application of the substrate, and finally the thermodynamic properties of the substrate. We believe that through this work a greater understanding for designing substrates will be achieved, one that is based on both thermodynamic and plasmonic properties as opposed to just plasmonic properties. This new understanding and potential change in substrate design will enable more applications for SERS based methodologies including targeting

  18. EXPERIENCIAS CONSTRUCCIONISTAS CON ROBÓTICA EDUCATIVA EN EL CENTRO INTERNACIONAL DE TECNOLOGÍAS AVANZADAS CONSTRUCTIONIST EXPERIENCES WITH EDUCATIONAL ROBOTICS AT THE INTERNATIONAL CENTRE FOR ADVANCED TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Kathia Pittí

    2010-02-01

    Full Text Available La tecnología digital en relación a su utilización en el ámbito educativo tienen dos vertientes: la de información y la de construcción. Aunque el énfasis actual, debido a la percepción popular, se inclina a la parte informativa, este trabajo descubre una parte olvidada del potencial que ofrece la tecnología digital como medio de construcción, específicamente la robótica educativa, que por su carácter polivalente y multidisciplinario se sitúa como una herramienta de apoyo al aprendizaje novedosa y necesaria de conocer por las nuevas generaciones.En este sentido, como ejemplo de buenas prácticas presentamos los talleres NXT de robótica del Centro Internacional de Tecnologías Avanzadas, un escenario construccionista de aprendizaje activo y lúdico, que les permite a los participantes mejorar su comprensión de la tecnología, potenciar habilidades y desarrollar la creatividad. Digital technology in the education field has two aspects: information and construction. Although, more importance is currently placed upon the information aspect due to the general public’s opinion, this article will focus on construction. The construction side has been neglected in the field of digital technology, especially with regard to educational robotics. This is an innovative and necessary learning tool used to support young students, thanks to its all-purpose and multidisciplinary approach.   As an example of good practices in this field, the NTX Robotics Workshops take place at the International Centre of Advanced Technologies (CITA. This constructionist scenario allows participants to learn through activities and games, improving their understanding of technology and boosting their skills, as well as developing their creativity.

  19. Ser idoso e o processo do envelhecimento: saúde percebida Ser anciano y el proceso de envejecimiento: salud percibida Being an elderly and the process aging: perceived health

    Directory of Open Access Journals (Sweden)

    Juliana Araújo Dias

    2011-06-01

    Full Text Available Pesquisa qualitativa tipo survey realizada em Rio Novo-Minas Gerais que objetivou analisar a concepção dos idosos sobre envelhecimento e suas percepções de serem/estarem idosos. Amostra por tipicidade composta por 20 voluntários com 60 ou mais anos, cadastrados no Programa de Vacinação do Município. Excluíram-se pessoas com: alteração de consciência; dissociações moderadas do pensamento; dificuldade para verbalização; e moradores rurais. Identificaram-se 385 crenças, segundo Rokeach, que tenderam em 76,3% à centralidade. Duas concepções de envelhecimento foram identificadas (nova oportunidade na vida e deterioração corporal, da autonomia e das relações. A própria idade e o nível de inserção social foram os critérios para conceituar quem não se sente idoso ou envelhecido e quem é ou não envelhecido, respectivamente.La investigación cualitativa de tipo encuesta realizada en Rio Novo, Minas Gerais, que tuvo como objetivo analizar el diseño de los ancianos acerca del envejecimiento y su percepción de ser/estar con edad avanzada. Muestra por tipicidad compuesta de 20 voluntarios con 60 o más años, registrados en el Programa de Inmunizaciones de la Ciudad. Se excluyeron las personas con: la conciencia alterada; disociación moderada de pensamiento; dificultad para verbalizar; los residentes rurales. Según Rokeach, fueron identificadas 385 creencias que tendieron en 76,3% a la centralidad. Dos concepciones del envejecimiento fueron predominantes (nueva oportunidad en la vida y la decadencia física, la autonomía y las relaciones. La edad y el nivel de integración social fueron los criterios usados para la conceptualización de los que no se sienten ancianos o envejecidos y que es de edad avanzada o no, respectivamente.Qualitative research type survey conducted in Rio Novo, Minas Gerais, which aimed to analyze the design of the elderly about aging and their perception of being /are elderly. Sample by typicality

  20. SER MUJER Y SER HOMBRE SEGÚN ALGUNAS MUJERES Y ALGUNOS VARONES SENTENCIADOS POR HOMICIDIO

    Directory of Open Access Journals (Sweden)

    MARITEL YANES

    2016-07-01

    Full Text Available Mediante el uso de los métodos cualitativos, se aplicó un guión temático sobre las opiniones de ser mujer y ser hombre de un grupo de mujeres y varones sentenciados por homicidio recluidos en el Centro de Reinserción del Estado de Tabasco (CRESET. Se buscaba conocer en qué medida sus concepciones de género influenciaron en su comportamiento homicida y observar cuales eran las principales diferencias. Se presentan los resultados del análisis de las respuestas al guion temático de las entrevistas realizadas, donde se observa el criterio de selección y el primer contacto con los entrevistados (as, las condiciones en que se llevaron a cabo las entrevistas, los objetivos y las categorías que se utilizaron para la elaboración del guion. Posteriormente, se describen y comparan las opiniones de las mujeres y de los hombres entrevistados sobre las categorías del guion temático que permiten apreciar múltiples elementos desde la perspectiva de género.

  1. Highly sensitive and flexible inkjet printed SERS sensors on paper.

    Science.gov (United States)

    Hoppmann, Eric P; Yu, Wei W; White, Ian M

    2013-10-01

    Surface enhanced Raman spectroscopy (SERS) has the potential to be utilized for the detection of a broad range of chemicals in trace quantities. However, because of the cost and complexity of SERS devices, the technology has been unable to fill the needs of many practical applications, in particular the need for rapid, portable, on-site detection in the field. In this work, we review a new methodology for trace chemical detection using inkjet-printed SERS substrates on paper. The detection performance of the inkjet-printed SERS devices is demonstrated by detecting 1,2-Bis(4-pyridyl)ethylene (BPE) at a concentration as low as 1.8 ppb. We then illustrate the primary advantages of paper SERS substrates as compared to conventional SERS substrates. By leveraging lateral flow concentration, the detection limit of paper SERS substrates can be further improved. Two real-world applications are demonstrated. First, the inkjet-printed SERS substrates are used as "dipsticks" for detecting the fungicide malachite green in water. Then, the flexible paper-based SERS devices are used as swabs to collect and detect trace residues of the fungicide thiram from a surface. We predict that the combination of ultra-low-cost fabrication with the advantages of easy-to-use dipsticks and swabs and the option of lateral flow concentration position ink-jet printed SERS substrates as a technology which will enable the application of SERS in solving critical problems for chemical detection in the field. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Myofilament Calcium Sensitivity: Mechanistic Insight into TnI Ser-23/24 and Ser-150 Phosphorylation Integration

    Directory of Open Access Journals (Sweden)

    Hussam E Salhi

    2016-12-01

    Full Text Available Troponin I (TnI is a major regulator of cardiac muscle contraction and relaxation. During physiological and pathological stress, TnI is differentially phosphorylated at multiple residues through different signaling pathways to match cardiac function to demand. The combination of these TnI phosphorylations can exhibit an expected or unexpected functional integration, whereby the function of two phosphorylations are different than that predicted from the combined function of each individual phosphorylation alone. We have shown that TnI Ser-23/24 and Ser-150 phosphorylation exhibit functional integration and are simultaneously increased in response to cardiac stress. In the current study, we investigated the functional integration of TnI Ser-23/24 and Ser-150 to alter cardiac contraction. We hypothesized that Ser-23/24 and Ser-150 phosphorylation each utilize distinct molecular mechanisms to alter the TnI binding affinity within the thin filament. Mathematical modeling predicts that Ser-23/24 and Ser-150 phosphorylation affect different TnI affinities within the thin filament to distinctly alter the Ca2+-binding properties of troponin. Protein binding experiments validate this assertion by demonstrating pseudo-phosphorylated Ser-150 decreases the affinity of isolated TnI for actin, whereas Ser-23/24 pseudo-phosphorylation is not different from unphosphorylated. Thus, our data supports that TnI Ser-23/24 affects TnI-TnC binding, while Ser-150 phosphorylation alters TnI-actin binding. By measuring force development in troponin-exchanged skinned myocytes, we demonstrate that the Ca2+ sensitivity of force is directly related to the amount of phosphate present on TnI. Furthermore, we demonstrate that Ser-150 pseudo-phosphorylation blunts Ser-23/24-mediated decreased Ca2+-sensitive force development whether on the same or different TnI molecule. Therefore, TnI phosphorylations can integrate across troponins along the myofilament. These data demonstrate

  3. Eliminación de colorantes alimentarios en disolución acuosa mediante procesos químicos y electroquímicos de oxidación avanzada

    OpenAIRE

    Donoso Morcillo, María Guadalupe

    2017-01-01

    La presente Tesis Doctoral tiene como objetivo el estudio de la eliminación de dos colorantes: Azul Patentado V y Tartracina, estos dos compuestos son ampliamente utilizados como colorantes alimentarios. Para llevar a cabo la eliminación de estos contaminantes se aplicarán procesos químicos, electroquímicos y sonoquímicos de oxidación. Los procesos químicos de oxidación avanzada que se investigan son un amplio rango de sistemas, que comprenden desde los procesos químicos homogéneos hasta l...

  4. Estudio DFT de la reactividad sobre superficies aminofosfolipídicas. Mecanismos de reacciones relacionadas con la generación de productos de glicación avanzada (AGEs)

    OpenAIRE

    Solís Calero, Christian

    2014-01-01

    En el presente trabajo se proponen mecanismos para varias reacciones que conducen a la formación de productos de glicación avanzada, en base a cálculos realizados a nivel PBE/GGA, en el contexto de la teoría del funcional de la densidad (DFT), en un modelo de una capa de fosfolípidos diseñada bajo condiciones periódicas de contorno. En los modelos periódicos usados, cada celda unidad contiene dos moléculas de fosfatidiletanolamina (PE), moléculas reactivas adicionales según sea la reacción es...

  5. Estudio a 2 años para medir la eficacia del fentanilo intranasal en pectina en el dolor irruptivo en enfermos con dolor no oncológico de edad avanzada

    OpenAIRE

    R. Salazar Vecino

    2015-01-01

    Los enfermos con dolor de moderado a intenso en patologías no oncológicas reciben habitualmente opioides para el control de su dolor. Muchos de ellos también padecen dolor irruptivo de las mismas características que el oncológico, sobre todo incidental a la deambulación, que en este estudio tratamos con fentanilo nasal en pectina. Se trata de 22 enfermos en la visita basal -20 mujeres (M) y 2 varones (V)- con dolor crónico no oncológico, de edad avanzada 74,7 (60-88), en un seguimiento de 24 ...

  6. IMPLEMENTACIÓN DE PROCEDIMIENTOS DE GOBERNABILIDAD TI EN LA RED DE INVESTIGACIÓN DE TECNOLOGÍA AVANZADA BASADO EN ITIL, COBIT Y LA ISO 20000-27000

    Directory of Open Access Journals (Sweden)

    Roberto Ferro Escobar

    2015-09-01

    Full Text Available La implementación de la gobernabilidad de las Tecnologías de la Información TI es esencial en todo tipo de organización, por lo tanto es necesaria su aplicación en la Red de Investigación de Tecnología Avanzada de la Universidad Distrital Francisco José de Caldas para lograr la alineación de las TI con los objetivos globales de esta, como apoyo en todas sus áreas. Para ello se debe efectuar la práctica de modelos organizacionales como ITIL, COBIT, ISO 20000 e ISO 27000

  7. Efectos de la toxina botulínica A (Botox®) intraarticular en la artrosis de rodilla avanzada Effects of intraarticular Botulinum Toxin A (Botox®) on refractory knee osteoarthritis

    OpenAIRE

    P. Fenollosa Vázquez; R. M. Izquierdo Aguirre; M. A. Canós Verdecho; J. Pallarés Delgado

    2011-01-01

    Objetivos: la osteoartritis es la enfermedad articular más común y una de los problemas de salud más frecuentes y sintomáticos en la madurez y senectud. Este trabajo describe nuestra experiencia clínica con inyecciones intraarticulares de toxina botulínica tipo A (TBA) en dolor de rodilla artrósico y refractario. Materiales y métodos: doce mujeres con gonartrosis avanzada y refractaria, acudieron a consulta para el manejo del dolor de rodilla de moderado a severo. Las pacientes estuvieron en ...

  8. Diseño de una instalación para tratar un agua residual textil combinando tratamiento físico-químico y oxidación avanzada (Qdiseño = 100 m3/d)

    OpenAIRE

    FLORENCIA CEVALLOS, EDUARDO ANDRÉS

    2016-01-01

    [ES] El presente Trabajo Final de Grado tiene como finalidad diseñar una instalación para tratar el agua residual procedente de la industria textil. El tratamiento consiste en aplicar un tratamiento físico-químico y un tratamiento de oxidación avanzada. Para definir los parámetros de ambos tratamientos, se han realizado ensayos a nivel de laboratorio empleando disoluciones modelo. En el tratamiento físico-químico se han ensayado diferentes coagulantes y floculantes, haciéndose ...

  9. Fundamentals and applications of SERS-based bioanalytical sensing

    Science.gov (United States)

    Kahraman, Mehmet; Mullen, Emma R.; Korkmaz, Aysun; Wachsmann-Hogiu, Sebastian

    2017-03-01

    Plasmonics is an emerging field that examines the interaction between light and metallic nanostructures at the metal-dielectric interface. Surface-enhanced Raman scattering (SERS) is a powerful analytical technique that uses plasmonics to obtain detailed chemical information of molecules or molecular assemblies adsorbed or attached to nanostructured metallic surfaces. For bioanalytical applications, these surfaces are engineered to optimize for high enhancement factors and molecular specificity. In this review we focus on the fabrication of SERS substrates and their use for bioanalytical applications. We review the fundamental mechanisms of SERS and parameters governing SERS enhancement. We also discuss developments in the field of novel SERS substrates. This includes the use of different materials, sizes, shapes, and architectures to achieve high sensitivity and specificity as well as tunability or flexibility. Different fundamental approaches are discussed, such as label-free and functional assays. In addition, we highlight recent relevant advances for bioanalytical SERS applied to small molecules, proteins, DNA, and biologically relevant nanoparticles. Subsequently, we discuss the importance of data analysis and signal detection schemes to achieve smaller instruments with low cost for SERS-based point-of-care technology developments. Finally, we review the main advantages and challenges of SERS-based biosensing and provide a brief outlook.

  10. Fundamentals and applications of SERS-based bioanalytical sensing

    Directory of Open Access Journals (Sweden)

    Kahraman Mehmet

    2017-03-01

    Full Text Available Plasmonics is an emerging field that examines the interaction between light and metallic nanostructures at the metal-dielectric interface. Surface-enhanced Raman scattering (SERS is a powerful analytical technique that uses plasmonics to obtain detailed chemical information of molecules or molecular assemblies adsorbed or attached to nanostructured metallic surfaces. For bioanalytical applications, these surfaces are engineered to optimize for high enhancement factors and molecular specificity. In this review we focus on the fabrication of SERS substrates and their use for bioanalytical applications. We review the fundamental mechanisms of SERS and parameters governing SERS enhancement. We also discuss developments in the field of novel SERS substrates. This includes the use of different materials, sizes, shapes, and architectures to achieve high sensitivity and specificity as well as tunability or flexibility. Different fundamental approaches are discussed, such as label-free and functional assays. In addition, we highlight recent relevant advances for bioanalytical SERS applied to small molecules, proteins, DNA, and biologically relevant nanoparticles. Subsequently, we discuss the importance of data analysis and signal detection schemes to achieve smaller instruments with low cost for SERS-based point-of-care technology developments. Finally, we review the main advantages and challenges of SERS-based biosensing and provide a brief outlook.

  11. Realidad y Ser: una lectura comparada de Zubiri y Heidegger

    OpenAIRE

    Molina García, Diego

    2006-01-01

    Este Artículo Analiza Comparativamente Las Concepciones De Ser Y Realidad En Lasfilosofías De Xavier Zubiri Y Martin Heidegger, Centrándose Específicamente Enlas Obras "Sobre La Esencia E Inteligencia Y Realidad" De Zubiri Y "Ser Ytiempo" De Heidegger.

  12. IR, Raman, SERS and DFT study of amoxicillin

    Science.gov (United States)

    Bebu, Andreea; Szabó, László; Leopold, Nicolae; Berindean, Cătălin; David, Leontin

    2011-05-01

    In this work a joint experimental and theoretical study on amoxicillin is reported. The molecular vibrations of amoxicillin were investigated by FTIR, FT-Raman and SERS spectroscopies. In parallel, quantum chemical calculations based on density functional theory (DFT) were used to determine the geometrical, energetic and vibrational characteristics of the molecule with particular emphasis put on the interaction and adsorption geometry of the molecule to the silver colloidal surface. The SERS spectrum of amoxicillin was recorded using a 532 nm laser line and hydroxylamine reduced silver colloid as SERS substrate. FTIR, FT-Raman and SERS spectra of amoxicillin were assigned based on DFT calculations with the hybrid B3LYP exchange-correlation functional, coupled with the standard 6-31G(d) basis set. The calculated molecular electrostatic potential (MEP) was used in conjunction with SERS data to predict the adsorption geometry of the molecule on the silver surface.

  13. Photonic Crystal Fibre SERS Sensors Based on Silver Nanoparticle Colloid

    International Nuclear Information System (INIS)

    Zhi-Guo, Xie; Yong-Hua, Lu; Pei, Wang; Kai-Qun, Lin; Jie, Yan; Hai, Ming

    2008-01-01

    A photonic crystal fibre (PCF) surface enhanced Raman scattering (SERS) sensor is developed based on silver nanoparticle colloid. Analyte solution and silver nanoparticles are injected into the air holes of PCF by a simple modified syringe to overcome mass-transport constraints, allowing more silver nanoparticles involved in SERS activity. This sensor offers significant benefit over the conventional SERS sensor with high flexibility, easy manufacture. We demonstrate the detection of 4-mercaptobenzoic acid (4-MBA) molecules with the injecting way and the common dipping measurement. The injecting way shows obviously better results than the dipping one. Theoretical analysis indicates that this PCF SERS substrate offers enhancement of about 7 orders of magnitude in SERS active area

  14. Prospectiva y cambio social: ¿cómo orientar las políticas de I+D en las sociedades tecnológicas avanzadas?

    Directory of Open Access Journals (Sweden)

    López Peláez, Antonio

    2009-08-01

    Full Text Available The analysis of the future and taking decisions related to the tendencies of the detectable technological and social change in our present time has turned into a basic tool in the scientific-technological policy of the contemporary societies. The technological development can not be improvised: technologies have a long gestation period and public policies about science and technology should establish some financing guidelines that make possible to develop a technological path which may be considered as strategic. At the same time, the technological advances generate different kind of risks and the citizens who live in advanced democratic societies claim to participate in the scientific-technological policy, not only through their legitimate political representatives but also through their own behaviour like consumers. In this article, the basic dimensions of the denominated Futures Studies are analyzed, the most outstanding contributions and the actual situation of the prospective investigations in Spain and The European Union.El análisis del futuro, y la toma de decisiones en función de las tendencias de cambio tecnológico y social detectables en el presente, se han convertido en una herramienta básica en la política científico-tecnológica de las sociedades contemporáneas. El desarrollo tecnológico no se improvisa: las tecnologías tienen un largo período de gestación, y las políticas públicas sobre la ciencia y la tecnología deben establecer pautas de financiación que hacen posible desarrollar unas trayectorias tecnológicas consideradas estratégicas. A la vez, los avances tecnológicos generan riesgos de diverso tipo, y los ciudadanos, en sociedades democráticas avanzadas, reclaman participar en el diseño de la política científico-tecnológica, tanto a través de sus legítimos representantes políticos, como a través de su propio comportamiento como consumidores. En este artículo, se analizan las dimensiones básicas de

  15. Planeación avanzada de la calidad del producto (apqp: conceptos básicos y un caso práctico

    Directory of Open Access Journals (Sweden)

    Humberto Gutiérrez Pulido

    2007-01-01

    Full Text Available La globalización económica y comercial es una realidad en muchos de los sectores de la economía. Ante ello muchas empresas buscan adoptar nuevas estrategias, ideas y metodologías en sus diferentes áreas, como una forma de mejorar su competitividad y de “mantenerse en forma”. Sin embargo, esta búsqueda enfocada a lo nuevo causa que algunas veces las compañías olviden o no apliquen metodologías que han dado resultados desde hace años, aunque hoy en día reciban poco publicidad. Este es el caso de la Planeación de la Calidad del Producto, que a pesar de su trascendencia e importancia quedó establecida desde la primera mitad de década de los noventa, muchas empresas, principalmente pequeñas y medianas (PYME, no han aplicado esta metodología de manera formal, sobre todo a través de los trabajos de los gurús de la calidad y de la metodología Advanced Product Quality Planning (APQP desarrollada por la industria automotriz de Estados Unidos. El objetivo de este trabajo es hacer un estudio bibliográfico sobre la planeación avanzada de la calidad del producto y enfatizar sus características e importancia mediante su aplicación en una empresa mediana instalada en la ciudad de Guadalajara (México. El estudio inició con un análisis de las prácticas prevalecientes en cuanto a planeación de la calidad del producto. Este análisis se completó con entrevistas semi-estructuradas a directivos claves de la empresa. Con base en esto se diseñó un proyecto de aplicación. En este trabajo se presentan los principales resultados y beneficios de la ejecución de dicho proyecto.

  16. Resultado de la intervención Enseñanza: dieta prescrita en la consulta de enfermedad renal crónica avanzada

    Directory of Open Access Journals (Sweden)

    M.ª Carmen Torres Torradeflot

    2016-03-01

    Full Text Available En la consulta de enfermedad renal crónica avanzada (ERCA, se proporcionan cuidados a los pacientes con enfermedad renal crónica con un filtrado glomerular (FG < 30 ml/min. Estos incluyen diferentes intervenciones de enfermería. Una de ellas es la intervención 5614 Enseñanza: dieta prescrita. Objetivo: Analizar la eficacia de la intervención 5614 Enseñanza: dieta prescrita, en pacientes ERCA realizada en la consulta de enfermería, en la primera visita. Material y métodos: Estudio cuasiexperimental. Se incluyeron 92 pacientes incidentes en la consulta ERCA en 2014. Se realizó la intervención 5614 Enseñanza: dieta prescrita y se evaluaron indicadores de resultado 1004 Estado nutricional a los 2 meses de la intervención. Se llevó a cabo una estadística descriptiva de las variables pre y post intervención. Resultados: Edad media 69,5±15 años, 64,1% (n=59 hombres, 35,9% (n=33 mujeres, 41,3% diabéticos. Después de la intervención el 62% de los pacientes disminuyeron el valor del K, el 54,3% el del P, el 55,4% el del colesterol total, el 59,8% el del colesterol-LDL, y el 44,6% el del ácido úrico. El 67,4% de los pacientes presentó pérdida ponderal. En estos pacientes la variación media de la albúmina fue -0,005±0,0028 mg/dL. El FG permaneció estable en el 63% de los pacientes. La PAS media disminuye en el 42,4% de los pacientes y la PAD media en el 38%. Conclusiones: Tras la intervención 5614 Enseñanza: dieta prescrita realizada a los pacientes ERCA en la primera visita, se observa disminución del peso y valores plasmáticos de P, K, colesterol- LDL, colesterol total y ácido úrico. La Función renal permanece estable. La concentración de albúmina en los pacientes que perdieron peso se mantiene estable. La diferencia de la media para los valores de K y colesterol total fue estadísticamente significativa.

  17. Aplicación pedagógica de la lingüística de corpus a una clase de gramática avanzada de español como segunda lengua

    Directory of Open Access Journals (Sweden)

    Paz, Yanira

    2013-09-01

    Full Text Available Este estudio recoge las experiencias de la enseñanza de un curso de gramática avanzada de español como segunda lengua usando la lingüística de corpus (LC como herramienta pedagógica. Si bien el uso pedagógico de LC en lenguas como el inglés ha sido ampliamente reportado, son escasos los estudios relacionados con el español. Como se desprenderá de estas experiencias, la LC permite el estudio de las estructuras de la lengua (objetivo de una clase de gramática avanzada y, al mismo tiempo, permite ver estas estructuras y sus usos en producciones reales y naturales aparte de presentarlas en contextos textuales y culturales auténticos. La LC se constituye, de esta manera, en una forma de aprendizaje mediante el uso de datos (‘data-driven learning’. El/la estudiante investigador/a usa datos, en un proceso inductivo, para llegar a la proposición de reglas gramaticales; todo lo contrario de lo que ha sido la enseñanza tradicional de la gramática del español como primera o segunda lengua.

  18. Simple morphological control over functional diversity of SERS materials

    Science.gov (United States)

    Semenova, A. A.; Goodilin, E. A.

    2018-03-01

    Nowadays, surface-enhanced Raman spectroscopy (SERS) becomes a promising universal low-cost and real-time tool in biomedical applications, medical screening or forensic analysis allowing for detection of different molecules below nanomolar concentrations. Silver nanoparticles and nanostructures have proven to be a common choice for SERS measurements due to a tunable plasmon resonance, high stability and facile fabrication methods. However, a proper design of silver-based nanomaterials for highly sensitive SERS applications still remains a challenge. In this work, effective and simple preparation methods of various silver nanostructures are proposed and systematically developed using aqueous diamminesilver (I) hydroxide as a precursor.

  19. Expresiones antagónicas en el ser humano

    OpenAIRE

    Falconí A., Fernando

    1998-01-01

    Este trabajo presenta las relaciones, la vida y la muerte, el bien y el mal, el amor y el odio/agresión, tratando de ratificar que sin la una no existe la otra pues sería totalmente invisible. Analiza estas relaciones occidente-oriente y todas las relaciones duales que se pueda generar en el ser humano Licenciado en Artes Visuales Cuenca

  20. Surface enhanced Raman scattering (SERS) fabrics for trace analysis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jun [National Engineering Laboratory for Advanced Yarn and Fabric Formation and Clean Production, Wuhan Textile University, Wuhan 430073 (China); Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Ministry of Education & College of Chemistry & Chemical Engineering, Hubei University, Wuhan 430062 (China); Zhou, Ji [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Ministry of Education & College of Chemistry & Chemical Engineering, Hubei University, Wuhan 430062 (China); Tang, Bin, E-mail: bin.tang@deakin.edu.au [National Engineering Laboratory for Advanced Yarn and Fabric Formation and Clean Production, Wuhan Textile University, Wuhan 430073 (China); Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216 (Australia); Zeng, Tian; Li, Yaling [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Ministry of Education & College of Chemistry & Chemical Engineering, Hubei University, Wuhan 430062 (China); Li, Jingliang [Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216 (Australia); Ye, Yong, E-mail: yeyong@hubu.edu.cn [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials & Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Ministry of Education & College of Chemistry & Chemical Engineering, Hubei University, Wuhan 430062 (China); Wang, Xungai [National Engineering Laboratory for Advanced Yarn and Fabric Formation and Clean Production, Wuhan Textile University, Wuhan 430073 (China); Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216 (Australia)

    2016-11-15

    Highlights: • Gold nanoparticles are in-situ synthesized on silk fabrics by heating. • Flexible silk fabrics with gold nanoparticles are used for surface-enhanced Raman scattering (SERS). • SERS activities of silk fabrics with different gold contents are investigated. - Abstract: Flexible SERS active substrates were prepared by modification of silk fabrics with gold nanoparticles. Gold nanoparticles were in-situ synthesized after heating the silk fabrics immersed in gold ion solution. Localized surface plasmon resonance (LSPR) properties of the treated silk fabrics varied as the concentration of gold ions changed, in relation to the morphologies of gold nanoparticles on silk. In addition, X-ray diffraction (XRD) was used to observe the structure of the gold nanoparticle treated silk fabrics. The SERS enhancement effect of the silk fabrics treated with gold nanoparticles was evaluated by collecting Raman signals of different concentrations of p-aminothiophenol (PATP), 4-mercaptopyridine (4-MPy) and crystal violet (CV) solutions. The results demonstrate that the silk fabrics corresponding to 0.3 and 0.4 mM of gold ions possess high SERS activity compared to the other treated fabrics. It is suggested that both the gold content and morphologies of gold nanoparticles dominate the SERS effect of the treated silk fabrics.

  1. Chemical imaging of live fibroblasts by SERS effective nanofilm.

    Science.gov (United States)

    Radziuk, D; Schuetz, R; Masic, A; Moehwald, H

    2014-11-28

    Reliable and strong surface enhanced Raman scattering (SERS) signatures of intracellular compartments in live NIH3T3 fibroblasts are collected in real time by means of SERS active thin nanofilm (30 nm) on colloidal silica (1.5 μm). Nanofilm is composed of preformed silver nanoparticles in the matrix of polyacrylic acid, protecting against heating (37 °C) in water, or culture medium or phosphate buffered saline aqueous solution. The SERS enhancement factors (EFs) of the order 10(8) allow single biomolecule detection in the native environment of a single live cell. Primary and secondary SERS hot spots of nanofilm are responsible for such high EFs. A slow SERS EF intensity decay occurs over a broader distance of micron silica with nanofilm, not achievable in a common core-shell model (silver nanoparticle coated with a thin silica layer). Extensive local field EFs and SERS EFs are mainly delivered by prolate silver nanoparticles ("rugby-like" shape). This is achieved if an incident field is polarized along the z-axis and the direction of incident polarization and main axis (z) are perpendicular to each other, not observable in water or on gold.

  2. Surface enhanced Raman scattering (SERS) fabrics for trace analysis

    International Nuclear Information System (INIS)

    Liu, Jun; Zhou, Ji; Tang, Bin; Zeng, Tian; Li, Yaling; Li, Jingliang; Ye, Yong; Wang, Xungai

    2016-01-01

    Highlights: • Gold nanoparticles are in-situ synthesized on silk fabrics by heating. • Flexible silk fabrics with gold nanoparticles are used for surface-enhanced Raman scattering (SERS). • SERS activities of silk fabrics with different gold contents are investigated. - Abstract: Flexible SERS active substrates were prepared by modification of silk fabrics with gold nanoparticles. Gold nanoparticles were in-situ synthesized after heating the silk fabrics immersed in gold ion solution. Localized surface plasmon resonance (LSPR) properties of the treated silk fabrics varied as the concentration of gold ions changed, in relation to the morphologies of gold nanoparticles on silk. In addition, X-ray diffraction (XRD) was used to observe the structure of the gold nanoparticle treated silk fabrics. The SERS enhancement effect of the silk fabrics treated with gold nanoparticles was evaluated by collecting Raman signals of different concentrations of p-aminothiophenol (PATP), 4-mercaptopyridine (4-MPy) and crystal violet (CV) solutions. The results demonstrate that the silk fabrics corresponding to 0.3 and 0.4 mM of gold ions possess high SERS activity compared to the other treated fabrics. It is suggested that both the gold content and morphologies of gold nanoparticles dominate the SERS effect of the treated silk fabrics.

  3. Trace detection of herbicides by SERS technique, using SERS-active substrates fabricated from different silver nanostructures deposited on silicon

    International Nuclear Information System (INIS)

    Dao, Tran Cao; Luong, Truc Quynh Ngan; Nguyen, Ngoc Hai; Kieu, Ngoc Minh; Luong, Thi Thuy; Cao, Tuan Anh; Le, Van Vu

    2015-01-01

    In this report we present the initial results of the use of different silver nanostructures deposited on silicon for trace detection of paraquat (a commonly used herbicide) using the surface-enhanced Raman scattering (SERS) effect. More specifically, the SERS-active substrates were fabricated from silver nanoparticles (AgNPs) deposited onto the flat surface of a silicon wafer (AgNPs@Si substrate), as well as on the surface of an obliquely aligned silicon nanowire (SiNW) array (AgNPs@SiNWs substrate), and from silver nanodendrites (AgNDs) deposited onto the flat surface of a silicon wafer (AgNDs@Si substrate). Results showed that with the change of the structure of the SERS-active substrate, higher levels of SERS enhancement have been achieved. Specifically, with the fabricated AgNDs@Si substrate, paraquat concentration as low as 1 ppm can be detected. (paper)

  4. Prevalence of self-reported overweight-obesity and its association with socioeconomic and health factors among older Mexican adults Prevalencia de sobrepeso-obesidad autorreportados y su asociación con factores socioeconómicos y de salud en población de edad avanzada en México

    Directory of Open Access Journals (Sweden)

    Liliana Ruiz-Arregui

    2007-01-01

    Full Text Available OBJECTIVE: To investigate the prevalence of obesity and its association with socioeconomic factors and comorbidities in a population-based study. MATERIAL AND METHODS: Data were examined from 4 605 persons ages 60 and older that participated in the 2001 Mexican Health and Aging Study, conducted in rural and urban communities in Mexico. The prevalence of obesity (according to self-reported weight and height was obtained, stratified by age, and logistic regression was used to study cross-sectional associations between obesity and socioeconomic factors. RESULTS: Of the population studied, 20.9% were classified as obese and the prevalence diminishes with age. Overall, women were more likely than mentobe obese. Lower educational level was associated with lower risk of overweight. In both men and women, obesity was more common between subjects with hypertension (OR 1.38 and 1.71, respectively and long-distance walk limitation (OR 2.08 and 2.21, respectively. CONCLUISON: In older Mexican adults, hypertension and long-distance walk limitation were independent associated factors for higher prevalence of obesity.OBJETIVO: Estudiar la prevalencia de obesidad y su asociación con factores socioeconómicos y comorbilidades. MATERIAL Y MÉTODOS: Se analizaron los datos de 4 605 personas de 60 años y más que participaron en el Estudio Nacional sobre Salud y Envejecimiento en México 2001 (ENASEM 2001 en zonas rurales y urbanas. La prevalencia de obesidad (peso y talla autorreportados se obtuvo estratificada por edad y mediante una regresión logística se asoció con factores socioeconómicos. RESULTADOS: 20.9% se clasificaron como obesos y la prevalencia disminuyó con la edad. En general las mujeres tuvieron mayor probabilidad de ser obesas. Una baja escolaridad se asoció con menor riesgo de sobrepeso. En hombres y mujeres la obesidad se asoció con hipertensión (RM 1.38 y 1.71 respectivamente y con dificultad para caminar (RM 2.08 y 2.21 respectivamente

  5. Microfluidic setup for on-line SERS monitoring using laser induced nanoparticle spots as SERS active substrate

    Directory of Open Access Journals (Sweden)

    Oana-M. Buja

    2017-01-01

    Full Text Available A microfluidic setup which enables on-line monitoring of residues of malachite green (MG using surface-enhanced Raman scattering (SERS is reported. The SERS active substrate was prepared via laser induced synthesis of silver or gold nanoparticles spot on the bottom of a 200 μm inner dimension glass capillary, by focusing the laser beam during a continuous flow of a mixture of silver nitrate or gold chloride and sodium citrate. The described microfluidic setup enables within a few minutes the monitoring of several processes: the synthesis of the SERS active spot, MG adsorption to the metal surface, detection of the analyte when saturation of the SERS signal is reached, and finally, the desorption of MG from the spot. Moreover, after MG complete desorption, the regeneration of the SERS active spot was achieved. The detection of MG was possible down to 10−7 M concentration with a good reproducibility when using silver or gold spots as SERS substrate.

  6. SERS-based application in food analytics (Conference Presentation)

    Science.gov (United States)

    Cialla-May, Dana; Radu, Andreea; Jahn, Martin; Weber, Karina; Popp, Jürgen

    2017-02-01

    To establish detection schemes in life science applications, specific and sensitive methods allowing for fast detection times are required. Due to the interaction of molecules with strong electromagnetic fields excited at metallic nanostructures, the molecular fingerprint specific Raman spectrum is increased by several orders of magnitude. This effect is described as surface-enhanced Raman spectroscopy (SERS) and became a very powerful analytical tool in many fields of application. Within this presentation, we will introduce innovative bottom-up strategies to prepare SERS-active nanostructures coated with a lipophilic sensor layer. To do so, the food colorant Sudan III, an indirect carcinogen substance found in chili powder, palm oil or spice mixtures, is detected quantitatively in the background of the competitor riboflavin as well as paprika powder extracts. The SERS-based detection of azorubine (E122) in commercial available beverages with different complexity (e.g. sugar content, alcohol concentration) illustrates the strong potential of SERS as a qualitative as well as semiquantitative prescan method in food analytics. Here, a good agreement between the estimated concentration employing SERS as well as the gold standard technique HPLC, a highly laborious method, is found. Finally, SERS is applied to detect vitamin B2 and B12 in cereals as well as the estimate the ratio of lycopene and β-carotene in tomatoes. Acknowledgement: Funding the projects "QuantiSERS" and "Jenaer Biochip Initiative 2.0" within the framework "InnoProfile Transfer - Unternehmen Region" the Federal Ministry of Education and Research, Germany (BMBF) is gratefully acknowledged.

  7. SERS substrates for in-situ biosensing (Conference Presentation)

    Science.gov (United States)

    Venugopalan, Priyamvada; Quilis, Nestor; Jakub, Dostalek; Wolfgang, Knoll

    2017-06-01

    Abstract: Recent years have seen a rapid progress in the field of surface-enhanced Raman spectroscopy (SERS) which is attributed to the thriving field of plasmonics [1]. SERS is a susceptible technique that can address basic scientific questions and technological problems. In both cases, it is highly dependent upon the plasmonic substrate, where excitation of the localized surface plasmon resonance enhances the vibrational scattering signal of the analyte molecules adsorbed on to the surface [2]. In this work, using finite difference time domain (FDTD) method we investigate the optical properties of plasmonic nanostructures with tuned plasmonic resonances as a function of dielectric environment and geometric parameters. An optimized geometry will be discussed based on the plasmonic resonant position and the SERS intensity. These SERS substrates will be employed for the detection of changes in conformation caused by interactions between an aptamer and analyte molecules. This will be done by using a microfluidic channel designed within the configuration of the lab-on-a-chip concept based on the intensity changes of the SERS signal. More efficient and reproducible results are obtained for such a quantitative measurement of analytes at low concentration levels. We will also demonstrate that the plasmonic substrates fabricated by top down approach such as e-beam lithography (EBL) and laser interference lithography (LIL) are highly reproducible, robust and can result in high electric field enhancement. Our results demonstrate the potential to use SERS substrates for highly sensitive detection schemes opening up the window for a wide range of applications including biomedical diagnostics, forensic investigation etc. Acknowledgement: This work was supported by the Austrian Science Fund (FWF), project NANOBIOSENSOR (I 2647). References: [1] J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao and R. P. V. Duyne., " Biosensing with plasmonic nanosensors," Nature

  8. El nivel de la hormona paratiroidea (PTH y no el de fósforo sérico es predictor de la progresión de la enfermedad renal en pacientes mayores con enfermedad renal crónica avanzada

    Directory of Open Access Journals (Sweden)

    Néstor Gabriel Toapanta Gaibor

    2017-03-01

    Conclusiones: En nuestro grupo de pacientes de edad avanzada el deterioro de la función renal es muy lento, especialmente en los pacientes en estadio 5. La albuminuria y la PTH al inicio del seguimiento son factores pronósticos en la evolución de su función renal.

  9. RETRASO DIAGNÓSTICO Y ENFERMEDAD AVANZADA EN LA INFECCIÓN POR EL VIRUS DE LA INMUNODEFICIENCIA HUMANA EN LA COMUNIDAD DE MADRID (2007-2011

    Directory of Open Access Journals (Sweden)

    Carlos Cevallos García

    2012-01-01

    Full Text Available Fundamentos: El diagnóstico precoz de la infección por VIH conlleva un beneficio a nivel individual y de salud pública. El objetivo fue determinar la prevalencia de retrasos en el diagnóstico de infección por VIH en la Comunidad de Madrid (CM y factores asociados. Métodos: Estudio descriptivo de diagnósticos de VIH de enero- 2007 a septiembre-2011. Se estudiaron todos los nuevos diagnósticos con linfocitos CD4+ menores de 200/µl (presentación enfermedad avanzada, PEA, 350/µl (retraso diagnóstico, RD y 500/µl. Análisis descriptivo y multivariante mediante regresión logística. Resultados: Se notificaron 3.347 casos. Se disponía de cifra de linfocitos CD4+ en 2.896 casos. El 29,7 presentaron PEA, 48,1% RD y 67,7% <500CD4+/µ. Tanto en autóctonos como foráneos, la edad y mecanismo de transmisión (usuarios de drogas inyectadas (UDI y heterosexual (HTX fueron variables independientes relacionadas con el diagnóstico tardío. En foráneos, el área geográfica de origen fue, igualmente, una variable independiente La probabilidad de PEA y RD en españoles aumentó con la edad de diagnóstico y fue mayor en HTX [OR:3,38 (IC95%:2,29-4,98 y 2,44 (1,67-3,56] y UDI [OR:2,41 (1,47-3,94 y 1,89 (1,19-3,01] respecto hombres que tienen sexo con hombres (HSH. La probabilidad de PEA y RD en foráneos aumentó con la edad de diagnóstico y fue mayor en HTX (OR:2,04 (1,44-2,89 y 2,29 (1,61-3,25 respecto HSH y en procedentes de Latinoamérica [OR:2,56 (1,48-4,42 y 2,29 (1,49-3,51] y África Subsahariana [OR:2,83 (1,52-5,28 y 2,52 (1,48-4,30] respecto originarios de Europa Occidental. Conclusiones: En la CM un elevado número de nuevos diagnósticos se producen en pacientes susceptibles a tratamiento, parte de ellos además presentan un grado importante de inmunosupresión. La edad, mecanismo de transmisión y país de origen se relacionan con un diagnóstico más tardío.

  10. SERS-Based Prognosis of Kidney Transplant Outcome

    Science.gov (United States)

    Chi, Jingmao

    Kidney transplant is the predominant procedure of all organ transplants around the world. The number of patients on the waiting list for a kidney is growing rapidly, yet the number of donations does not keep up with the fast-growing need. This thesis focuses on the surface-enhanced Raman scattering (SERS) analysis of urine samples for prognosis of kidney transplant outcome, which can potentially let patients have a more timely treatment as well as expand the organ pool for transplant. We have observed unique SERS spectral features from urine samples of kidney transplant recipients that have strong associations with the kidney acute rejection (AR) based on the analysis of urine one day after the transplant. Our ability to provide an early prognosis of transplant outcome is a significant advance over the current gold standard of clinical diagnosis, which occurs weeks or months after the surgical procedure. The SERS analysis has also been applied to urine samples from deceased kidney donors. Excellent classification ability was achieved when the enhanced PCA-LDA analysis was used to classify and identify urine samples from different cases. The sensitivity of the acute tubular necrosis (ATN) class is more than 90%, which can indicate the usable kidneys in the high failure risk category. This analysis can help clinicians identify usable kidneys which would be discarded using conventional clinic methods as high failure risk. To investigate the biomarkers that cause the unique SERS features, an HPLC-SERS-MS approach was established. The high-performance liquid chromatography (HPLC) was used to separate the urinary components to reduce the sample complexity. The mass spectrometry (MS) was used to determine the formulas and the structures of the biomarkers. The presence of 1-methyl-2-pyrrolidone (NMP) and adenine in urine samples were confirmed by both MS and SERS analysis. Succinylmonocholine, a metabolite of suxamethonium, has a potential to be the biomarker that causes

  11. Normal Raman and SERS spectroscopy of the vitamin E

    Energy Technology Data Exchange (ETDEWEB)

    Cai Tiantian; Gu Huaimin; Yuan Xiaojuan; Liu Fangfang, E-mail: guhm@scnu.edu.cn [MOE Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, 510631, Guangzhou (China)

    2011-01-01

    In this study, surface-enhanced Raman scattering(SERS)spectra of vitamin E were obtained on colloidal silver(Ag). Alpha-(-) tocopherol which is the only form that is recognized to meet human requirements was selected to study. The analytes ({+-})- -tocopherol were dissolved in chloroform (CHCl{sub 3}) and the silver colloid was poured into the compound. Silver colloid was reduced by hydroxylamine hydrochloride. The analytes were the supernatant after standing the mixture for the reason that chloroform have no signals in surface-enhanced Raman scattering in the Ag colloid, and it would not affect the determination of the ({+-})- -tocopherol. The Normal Raman and SERS spectrum of Vitamin E were contrastively studied to realize how the vitamin E stuck to the silver nanoparticles. The results show the fat-soluble substances can be analysed by SERS. The spectra indicate that the molecules are adsorbed on the surface through the COO- groups by the simultaneous involvement of a and -type coordination. These results suggest some important criteria for consideration in SERS measurements and also provide important insights into the problem of predicting SERS activities for different fat-soluble substances.

  12. Correlative SEM SERS for quantitative analysis of dimer nanoparticles.

    Science.gov (United States)

    Timmermans, F J; Lenferink, A T M; van Wolferen, H A G M; Otto, C

    2016-11-14

    A Raman microscope integrated with a scanning electron microscope was used to investigate plasmonic structures by correlative SEM-SERS analysis. The integrated Raman-SEM microscope combines high-resolution electron microscopy information with SERS signal enhancement from selected nanostructures with adsorbed Raman reporter molecules. Correlative analysis is performed for dimers of two gold nanospheres. Dimers were selected on the basis of SEM images from multi aggregate samples. The effect of the orientation of the dimer with respect to the polarization state of the laser light and the effect of the particle gap size on the Raman signal intensity is observed. Additionally, calculations are performed to simulate the electric near field enhancement. These simulations are based on the morphologies observed by electron microscopy. In this way the experiments are compared with the enhancement factor calculated with near field simulations and are subsequently used to quantify the SERS enhancement factor. Large differences between experimentally observed and calculated enhancement factors are regularly detected, a phenomenon caused by nanoscale differences between the real and 'simplified' simulated structures. Quantitative SERS experiments reveal the structure induced enhancement factor, ranging from ∼200 to ∼20 000, averaged over the full nanostructure surface. The results demonstrate correlative Raman-SEM microscopy for the quantitative analysis of plasmonic particles and structures, thus enabling a new analytical method in the field of SERS and plasmonics.

  13. SERS investigation of coatings on thermal modified titanium dioxide nanoparticles

    Science.gov (United States)

    Amininejad, Sayed; Niessner, Reinhard; Baumann, Thomas

    2017-04-01

    Titanium dioxide nanoparticles (TiO2) are progressively manufactured and used in a wide variety of products such as sunscreens, papers, paints and toothpastes. The increase in the production and use of Titanium dioxide nanoparticles would escalate the risk for exposure of the natural environments to these compounds. There are several techniques for identifying and quantifying nanoparticles and Surface-Enhanced Raman Scattering (SERS) is an emerging technique which combines raman spectroscopy with nanotechnology. SERS can also be used to investigate the changes of natural coatings on nanoparticles as an important factor regarding their environmental fate and biological effects. In this work, TiO2 P25 nanoparticles are thermally modified at different temperatures to study the effects of thermal shock on the crystal structure, surface properties and subsequently the Surface-Enhanced Raman Scattering from 4-Mercaptobenzoic acid molecules coated on TiO2 nanoparticles has been observed. The results show that 4-Mercaptobenzoic acid molecules coated on nanoparticles exhibit different degree SERS enhancement on the surface of different nanoparticles modified at different temperatures by thermal modification method. This research work is expected to be important for improving SERS performance of TiO2 nanoparticles for characterization of natural coatings. Keywords: SERS, TiO2, 4-Mercaptobenzoic acid

  14. Ser lugar e ser território como experiências do ser-no-mundo: um exercício de existencialismo geográfico

    Directory of Open Access Journals (Sweden)

    Angelo Serpa

    2017-10-01

    Full Text Available Este ensaio busca aprofundar uma abordagem existencialista dos conceitos de lugar e território assumindo o pressuposto de que eles remetem, antes de tudo, a experiências geográficas que ora se distinguem, ora se aproximam e carregam em si a marca do espaço vivido. Para esta análise, parte-se do conceito de geograficidade – a base pré-consciente e pré-conceitual da geografia – assumindo também que, antes de qualquer conceituação ou estratégia de representação conceitual, as pessoas são seres essencialmente espaciais e que viver é produzir/experienciar espaço. O ensaio está dividido em seis seções: a introdução, uma problematização da dialética entre interior e exterior e seu desdobramento numa abordagem de como lugar e território se exprimem como modos geográficos de existência no espaço público; nas duas últimas seções, reflete-se sobre o papel do corpo nos processos de apropriação do espaço e sobre como ser lugar e ser território se exprimem como facetas do ser-no-mundo em seu sentido mais político.

  15. Synthesis, characterization and SERS activity of Au-Ag nanorods

    Science.gov (United States)

    Philip, Daizy; Gopchandran, K. G.; Unni, C.; Nissamudeen, K. M.

    2008-09-01

    The formation mechanism and morphology of Au-Ag bimetallic colloidal nanoparticles depend on the composition. Ag coated Au colloidal nanoparticles have been prepared by deposition of Ag through chemical reduction on performed Au colloid. The composition of the Au 100- x-Ag x particles was varied from x = 0 to 50. The obtained colloids were characterized by UV-vis spectroscopy and transmission electron microscopy (TEM). The Au 80-Ag 20 colloid consists of alloy nanorods with dimension of 25 nm × 100 nm. The activity of these nanorods in surface enhanced Raman spectroscopy (SERS) was checked by using sodium salicylate as an adsorbate probe. Intense SERS bands are observed indicating its usefulness as a SERS substrate in near infrared (NIR) laser excitation.

  16. ser en otorrinolaringología

    OpenAIRE

    Castillo F,Marcela; Lanas V,Andrés

    2006-01-01

    Esta revisión bibliográfica analiza los diferentes tipos de láser usados en otorrinolaringología, destacando las propiedades de cada uno. Posteriormente describe las características de una sesión con anestesia y uso de láser y las patologías con indicaciones de cirugía láser. Estas se clasifican en cinco rubros. Patología laringotraqueal, patología faringobucal, patología sinusal, otología y dermatología cérvico facial. En la primera se analizan: lesiones fonoquirúrgico, papilomatosis larínge...

  17. Superhydrophobic SERS substrates based on silicon hierarchical nanostructures

    Science.gov (United States)

    Chen, Xuexian; Wen, Jinxiu; Zhou, Jianhua; Zheng, Zebo; An, Di; Wang, Hao; Xie, Weiguang; Zhan, Runze; Xu, Ningsheng; Chen, Jun; She, Juncong; Chen, Huanjun; Deng, Shaozhi

    2018-02-01

    Silicon nanostructures have been cultivated as promising surface enhanced Raman scattering (SERS) substrates in terms of their low-loss optical resonance modes, facile functionalization, and compatibility with today’s state-of-the-art CMOS techniques. However, unlike their plasmonic counterparts, the electromagnetic field enhancements induced by silicon nanostructures are relatively small, which restrict their SERS sensing limit to around 10-7 M. To tackle this problem, we propose here a strategy for improving the SERS performance of silicon nanostructures by constructing silicon hierarchical nanostructures with a superhydrophobic surface. The hierarchical nanostructures are binary structures consisted of silicon nanowires (NWs) grown on micropyramids (MPs). After being modified with perfluorooctyltriethoxysilane (PFOT), the nanostructure surface shows a stable superhydrophobicity with a high contact angle of ˜160°. The substrate can allow for concentrating diluted analyte solutions into a specific area during the evaporation of the liquid droplet, whereby the analytes are aggregated into a small volume and can be easily detected by the silicon nanostructure SERS substrate. The analyte molecules (methylene blue: MB) enriched from an aqueous solution lower than 10-8 M can be readily detected. Such a detection limit is ˜100-fold lower than the conventional SERS substrates made of silicon nanostructures. Additionally, the detection limit can be further improved by functionalizing gold nanoparticles onto silicon hierarchical nanostructures, whereby the superhydrophobic characteristics and plasmonic field enhancements can be combined synergistically to give a detection limit down to ˜10-11 M. A gold nanoparticle-functionalized superhydrophobic substrate was employed to detect the spiked melamine in liquid milk. The results showed that the detection limit can be as low as 10-5 M, highlighting the potential of the proposed superhydrophobic SERS substrate in

  18. Monitoring enzymatic degradation of pericellular matrices through SERS stamping

    Science.gov (United States)

    Yan, Bo; Hong, Yan; Chen, Tianhong; Reinhard, Björn M.

    2012-06-01

    We introduce a surface enhanced Raman spectroscopy (SERS) stamping approach for acquiring cell-surface specific vibrational spectra of individual living cells under physiological conditions. The SERS stamping approach utilizes a nanostructured metal surface on top of a lithographically defined piston that can be translated in 3-dimensions with nanometer resolution to contact living cells in solution with a pristine metal surface. We applied this approach to characterize the chemical composition of the cellular surface of living MCF7 breast cancer cells and to monitor its change upon addition of the enzyme hyaluronidase, which degrades major constituents of the pericellular matrix. Although the cell surface spectra show significant cell-to-cell fluctuations, a statistical barcode analysis of the spectra ensembles reveals systematic changes in the cell surface SERS spectra upon addition of hyaluronidase, which are consistent with a thinning of the pericellular matrix.We introduce a surface enhanced Raman spectroscopy (SERS) stamping approach for acquiring cell-surface specific vibrational spectra of individual living cells under physiological conditions. The SERS stamping approach utilizes a nanostructured metal surface on top of a lithographically defined piston that can be translated in 3-dimensions with nanometer resolution to contact living cells in solution with a pristine metal surface. We applied this approach to characterize the chemical composition of the cellular surface of living MCF7 breast cancer cells and to monitor its change upon addition of the enzyme hyaluronidase, which degrades major constituents of the pericellular matrix. Although the cell surface spectra show significant cell-to-cell fluctuations, a statistical barcode analysis of the spectra ensembles reveals systematic changes in the cell surface SERS spectra upon addition of hyaluronidase, which are consistent with a thinning of the pericellular matrix. Electronic supplementary information

  19. La cuestión del ser y la Trinidad

    Directory of Open Access Journals (Sweden)

    Michael Schulz

    2009-01-01

    Full Text Available A la luz de la revelación de la Trinidad, el teólogo suizo Hans Urs von Balthasar plantea la cuestión del ser. Su ontología subraya la positividad del ser: características del ser que la tradición metafísica identifica con la deficiencia del ser finito en comparación con el ser de Dios; en contraste, Balthasar las interpreta como indicios que muestran la semejanza del ser a la Trinidad: diferencia, alteridad, receptividad, pasividad. Este planteamiento de una ontología trinitaria implica un debate sobre su estado epistemológico. El autor del presente artículo, concluye que sin ontología queda difícil la justificación racional de la posibilidad de una revelación definitiva de Dios. De tal manera, recurriendo a la prueba apagógica, se muestra la dimensión ontológica del pensamiento.In the light of revelation regarding the Trinity, the Swiss theologian Hans Urs von Balthasar posits the question of being. His ontology underlines the positivity of being: the characteristics of being, characterisitcs that metaphysical tradition identified with the deficiency of finite being in comparison to the being of God, Balthasar, in constrast to this tradition, interprets them as indicators that show the similarity of being with the Trinity: difference, alterity, receptivity, passivity. The author of the present article concludes that, without ontology, the rational justification of the possibility of a definitive revelation of God remains difficult. In this way, recurring to the apagogic proof, the ontological dimension of this thought is shown.

  20. SER Y ESTAR CON ADJETIVOS – SIGNIFICACION DE LAS PROPOSICIONES SER Y ESTAR CON ADJETIVOS – SIGNIFICACION DE LAS PROPOSICIONES

    Directory of Open Access Journals (Sweden)

    Javier García de María

    2008-07-01

    Full Text Available Ser y estar: uno de los temas difíciles de la enseñanza/aprendizaje del español. Este trabajo expone un enfoque que recurre a la significación como hilo conductor. Por una parte, a la significación de ser y de estar como verbos, en sí mismos. Por otra, a la significación de los adjetivos. El planteamiento no es ya qué significa un determinado adjetivo con ser o con estar, sino cuál de estos verbos puede expresar su significado único o cada uno de sus significados. Sobre esta base el análisis considera, primero, los significados de ser/estar y los significados de un adjetivo dado y, segundo, los resultados significativos que arroja la relación entre verbos y adjetivo. Cuando el significado de un adjetivo se pueda expresar con los dos verbos, la elección vendrá determinada por la intencionalidad del hablante en el contexto comunicativo en que se encuentre. A partir de aquí las construcciones en las que aparecen ser y estar son tratadas como proposiciones retórico-argumentativas.Ser and estar: a difficult aspect of Spanish as a foreign language. This essay presents an approach that takes signification as guide line. On the one hand, the signification of ser and estar for their own cause; on the other hand the signification of the adjectives. The question is no longer what the meaning of a given adjective is with ser or with estar, but with which of the two verbs is it possible to express the unique meaning or each of the meanings of that adjective. Starting from this basis the approach considers first, the isolated meanings of the verbs and of the adjectives and, second, the resultant signification out of the relation between the two sides. If the meaning of a given adjective can be expressed by both verbs, the selection of the verb is determined by the intentionality of the speaker in the communicative context in which he negotiates. From this background on the syntactical constructions in which ser and estar appear are treated as

  1. DEFINICIÓN DE UN MODELO DE SEGURIDAD PARA LA RED DE INVESTIGACIÓN DE TECNOLOGÍA AVANZADA DE LA UNIVERSIDAD DISTRITAL “FRANCISCO JOSÉ DE CALDAS” RITA-UD

    Directory of Open Access Journals (Sweden)

    Diego Rocha

    2011-11-01

    Full Text Available Uno de los aspectos más importantes dentro de las networking se relaciona con la protección de la información. Este trabajo permite identificar los aspectos más importantes a considerar en la definición de un modelo de seguridad para la red de investigación de tecnología avanzada de la Universidad Distrital Francisco José de Caldas RITA-UD basado en la aplicación de las normas ISO27001 y NTC-ISO/IEC17799.El diseño final obtenido es una propuesta para la implementación de un Firewall Cisco ASA5520.

  2. Anemia nos pacientes com insuficiência cardíaca avançada Anemia en los pacientes con insuficiencia cardíaca avanzada Anemia in patients with advanced heart failure

    Directory of Open Access Journals (Sweden)

    Juliano Cardoso

    2010-10-01

    Full Text Available FUNDAMENTO: Anemia está associada à pior evolução nos pacientes com insuficiência cardíaca (IC. Entretanto, há poucos estudos sobre a anemia nos pacientes com IC avançada. OBJETIVO: Avaliar as características da anemia na IC em fase avançada. MÉTODOS: Foram incluídos 99 pacientes hospitalizados para compensação de IC (CF IV/NYHA, com idade > 18 anos e FEVE 12 g/dl. A anemia foi marcador independente de mau prognóstico na análise multivariada (mortalidade 47% vs 24,6%, p = 0,016, risco relativo 2,54. CONCLUSÃO: Anemia acomete, aproximadamente, 1/3 dos pacientes com IC avançada, e a deficiência de ferro é uma importante etiologia. Pacientes anêmicos são mais idosos e apresentaram função renal mais deteriorada. A melhora da congestão não foi suficiente para melhorar a anemia na maioria dos casos. Nos pacientes com IC avançada, a anemia é marcador independente de mau prognóstico.FUNDAMENTO: Anemia está asociada a peor evolución en los pacientes con insuficiencia cardíaca (IC. Mientras tanto, hay pocos estudios sobre la anemia en los pacientes con IC avanzada. OBJETIVO: Evaluar las características de la anemia en la IC en fase avanzada. MÉTODOS: Fueron incluidos 99 pacientes hospitalizados para compensación de IC (CF IV/NYHA, con edad > 18 años y FEVI 12 g/dl. La anemia fue marcador independiente de mal pronóstico en el análisis multivariado (mortalidad 47% vs 24,6%, p = 0,016, riesgo relativo 2,54. CONCLUSIÓN: Anemia afecta, aproximadamente, 1/3 de los pacientes con IC avanzada, y la deficiencia de hierro es una importante etiología. Pacientes anémicos son más añosos y presentaron función renal más deteriorada. La mejora de la congestión no fue suficiente para mejorar la anemia en la mayoría de los casos. En los pacientes con IC avanzada, la anemia es marcador independiente de mal pronóstico.BACKGROUND: Anemia is linked with worsening of progress in patients with heart failure (HF. However, there are

  3. Time-resolved SERS for characterizing extracellular vesicles

    Science.gov (United States)

    Rojalin, Tatu; Saari, Heikki; Somersalo, Petter; Laitinen, Saara; Turunen, Mikko; Viitala, Tapani; Wachsmann-Hogiu, Sebastian; Smith, Zachary J.; Yliperttula, Marjo

    2017-02-01

    The aim of this work is to develop a platform for characterizing extracellular vesicles (EV) by using gold-polymer nanopillar SERS arrays simultaneously circumventing the photoluminescence-related disadvantages of Raman with a time-resolved approach. EVs are rich of biochemical information reporting of, for example, diseased state of the biological system. Currently, straightforward, label-free and fast EV characterization methods with low sample consumption are warranted. In this study, SERS spectra of red blood cell and platelet derived EVs were successfully measured and their biochemical contents analyzed using multivariate data analysis techniques. The developed platform could be conveniently used for EV analytics in general.

  4. Vaccines against dengue: a review of current candidate vaccines at advanced development stages Vacunas contra el dengue: una revisión de las vacunas candidatas en etapas avanzadas de desarrollo

    Directory of Open Access Journals (Sweden)

    Joachim Hombach

    2007-04-01

    Full Text Available Los esfuerzos sistemáticos para desarrollar una vacuna contra el dengue comenzaron durante la Segunda Guerra Mundial, inspirados en el desarrollo exitoso de una vacuna contra la fiebre amarilla. Sin embargo, la falta de modelos adecuados de la enfermedad, la información incompleta acerca de los mecanismos patogénicos y los insuficientes incentivos económicos han dificultado los avances. Debido al impacto actual del dengue en todo el mundo y su explosiva diseminación, ha aumentado el interés en el desarrollo de vacunas contra el dengue y se ha avanzado considerablemente en el camino hacia la evaluación clínica de vacunas candidatas. La Iniciativa para la Investigación en Vacunas, de la Organización Mundial de la Salud, está facilitando el desarrollo de y los ensayos con las vacunas candidatas. Las vacunas contra el dengue que se encuentran actualmente en etapas avanzadas de desarrollo son de tres tipos fundamentales: 1 vivas atenuadas; 2 vivas recombinantes; y 3 de subunidades e inactivadas. La mayoría de las vacunas en cartera son vivas atenuadas, siguiendo el camino exitoso de otras vacunas vivas contra flavivirus, especialmente de la desarrollada contra la fiebre amarilla. En general, las vacunas contra el dengue que se encuentran actualmente en desarrollo están bastante avanzadas y son muy diversas. Muy pronto comenzará la evaluación de estas vacuna candidatas en ensayos de eficacia basados en poblaciones expuestas, lo que requerirá resolver varios problemas técnicos, operacionales y regulatorios.

  5. Visualization of elongation measurements using an SER universal testing platform

    Czech Academy of Sciences Publication Activity Database

    Pivokonský, Radek; Filip, Petr; Zelenková, Jana

    2015-01-01

    Roč. 25, č. 1 (2015), s. 1-8 ISSN 1430-6395 R&D Projects: GA ČR(CZ) GAP105/11/2342 Institutional support: RVO:67985874 Keywords : elongational viscosity * Universal Testing Platform (SER) * polymer melts * LDPE Subject RIV: BK - Fluid Dynamics Impact factor: 1.241, year: 2015

  6. SERS internship fall 1995 abstracts and research papers

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Beverly

    1996-05-01

    This report is a compilation of twenty abstracts and their corresponding full papers of research projects done under the US Department of Energy Science and Engineering Research Semester (SERS) program. Papers cover a broad range of topics, for example, environmental transport, supercomputers, databases, biology. Selected papers were indexed separately for inclusion the the Energy Science and Technology Database.

  7. Graphene Plasmonics: Guiding, Excitation and Strong SERS Enhancement

    DEFF Research Database (Denmark)

    Xiao, Sanshui

    Propagation of graphene plasmons in nanoribbon waveguides is numerically investigated and excitation of the graphene plasmons in a continuous graphene monolayer is experimentally demonstrated. Interaction between a graphene monolayer with metallic nanostructures is further experimentally studied......, and strong SERS enhancement for the graphene monolayer is observed with the aid of metallic nanostructures....

  8. Expanding Applications of SERS through Versatile Nanomaterials Engineering (Postprint)

    Science.gov (United States)

    2017-06-22

    Puebla and L. M. Liz-Marzan, Traps and cages for universal SERS detection, Chem. Soc. Rev., 2012, 41(1), 43–51. 32 (a) A. Grondin, D. C. Robson, W. E...de Aber- asturi, J.-M. Montenegro, I. Ruiz de Larramendi, T. Rojo, T. A. Klar and R. Alvarez- Puebla , et al., Optical Sensing of Small Ions with

  9. New nanocomposites for SERS studies of living cells and mitochondria

    DEFF Research Database (Denmark)

    Sarycheva, A. S.; Brazhe, N. A.; Baizhumanov, A. A.

    2016-01-01

    molecules. The SERS spectra of functional mitochondria are sensitive to the activity of the mitochondrial electron transport chain, thus making the method a novel label-free approach to monitor the redox state and conformation of cytochromes in their natural cell environment. The developed nanocomposites...

  10. Plasmonic response and SERS modulation in electrochemical applied potentials

    DEFF Research Database (Denmark)

    Martino, G. Di; Turek, V. A.; Tserkezis, Christos

    2017-01-01

    amplification of 100 molecules. Modulation of the plasmonic spectra and the SERS response is observed with applied voltage under a variety of electrolytes. Different scenarios are discussed to untangle the various mechanisms that can be involved in the electronic interaction between NPs and electrode surfaces....

  11. BACH1 Ser919Pro variant and breast cancer risk

    International Nuclear Information System (INIS)

    Vahteristo, Pia; Yliannala, Kristiina; Tamminen, Anitta; Eerola, Hannaleena; Blomqvist, Carl; Nevanlinna, Heli

    2006-01-01

    BACH1 (BRCA1-associated C-terminal helicase 1; also known as BRCA1-interacting protein 1, BRIP1) is a helicase protein that interacts in vivo with BRCA1, the protein product of one of the major genes for hereditary predisposition to breast cancer. Previously, two BACH1 germ line missense mutations have been identified in early-onset breast cancer patients with and without family history of breast and ovarian cancer. In this study, we aimed to evaluate whether there are BACH1 genetic variants that contribute to breast cancer risk in Finland. The BACH1 gene was screened for germ line alterations among probands from 43 Finnish BRCA1/2 negative breast cancer families. Recently, one of the observed common variants, Ser-allele of the Ser919Pro polymorphism, was suggested to associate with an increased breast cancer risk, and was here evaluated in an independent, large series of 888 unselected breast cancer patients and in 736 healthy controls. Six BACH1 germ line alterations were observed in the mutation analysis, but none of these were found to associate with the cancer phenotype. The Val193Ile variant that was seen in only one family was further screened in an independent series of 346 familial breast cancer cases and 183 healthy controls, but no additional carriers were observed. Individuals with the BACH1 Ser919-allele were not found to have an increased breast cancer risk when the Pro/Ser heterozygotes (OR 0.90; 95% CI 0.70–1.16; p = 0.427) or Ser/Ser homozygotes (OR 1.02; 95% CI 0.76–1.35; p = 0.91) were compared to Pro/Pro homozygotes, and there was no association of the variant with any breast tumor characteristics, age at cancer diagnosis, family history of cancer, or survival. Our results suggest that the BACH1 Ser919 is not a breast cancer predisposition allele in the Finnish study population. Together with previous studies, our results also indicate that although some rare germ line variants in BACH1 may contribute to breast cancer development, the

  12. BACH1 Ser919Pro variant and breast cancer risk

    Directory of Open Access Journals (Sweden)

    Eerola Hannaleena

    2006-01-01

    Full Text Available Abstract Background BACH1 (BRCA1-associated C-terminal helicase 1; also known as BRCA1-interacting protein 1, BRIP1 is a helicase protein that interacts in vivo with BRCA1, the protein product of one of the major genes for hereditary predisposition to breast cancer. Previously, two BACH1 germ line missense mutations have been identified in early-onset breast cancer patients with and without family history of breast and ovarian cancer. In this study, we aimed to evaluate whether there are BACH1 genetic variants that contribute to breast cancer risk in Finland. Methods The BACH1 gene was screened for germ line alterations among probands from 43 Finnish BRCA1/2 negative breast cancer families. Recently, one of the observed common variants, Ser-allele of the Ser919Pro polymorphism, was suggested to associate with an increased breast cancer risk, and was here evaluated in an independent, large series of 888 unselected breast cancer patients and in 736 healthy controls. Results Six BACH1 germ line alterations were observed in the mutation analysis, but none of these were found to associate with the cancer phenotype. The Val193Ile variant that was seen in only one family was further screened in an independent series of 346 familial breast cancer cases and 183 healthy controls, but no additional carriers were observed. Individuals with the BACH1 Ser919-allele were not found to have an increased breast cancer risk when the Pro/Ser heterozygotes (OR 0.90; 95% CI 0.70–1.16; p = 0.427 or Ser/Ser homozygotes (OR 1.02; 95% CI 0.76–1.35; p = 0.91 were compared to Pro/Pro homozygotes, and there was no association of the variant with any breast tumor characteristics, age at cancer diagnosis, family history of cancer, or survival. Conclusion Our results suggest that the BACH1 Ser919 is not a breast cancer predisposition allele in the Finnish study population. Together with previous studies, our results also indicate that although some rare germ line variants

  13. Desarrollo de materiales compuestos Invar-Carbono y caracterización con técnicas pulvimetalúrgicas avanzadas

    OpenAIRE

    Pretus Yagüe, Miguel

    2014-01-01

    Los materiales compuestos de matriz metálica (MCMMs) son materiales muy atractivos para ser empleados en multitud de aplicaciones y áreas de la ingeniería. Aunque existen muchos casos de estudio relacionados con este tipo de materiales, la mayoría de los esfuerzos han sido dirigidos a potenciar y desarrollar materiales compuestos de matriz polimérica. Este proyecto tiene como interés fundamental analizar un material compuesto formado por Invar (aleación de hierro y níquel) que constituirá el ...

  14. Análisis numérico de la distribución del tiempo de residencia en tipologías avanzadas de mezcladores tubulares

    OpenAIRE

    Femenía Martínez, Daniel

    2015-01-01

    Los reactores de flujo oscilatorio (OBR) son equipos tubulares aptos para el mezclado, en los que se superpone un flujo neto y un flujo oscilatorio. La velocidad del flujo neto que atraviesa el tubo es propia de un flujo laminar con muy bajo número de Reynolds, mientras que las velocidades superpuestas por la oscilación de tipo sinusoidal pueden ser de hasta tres órdenes de magnitud mayor. Los tubos contienen elementos insertados que promueven el mezclado radial -típicamente coronas circulare...

  15. Alteración argilica avanzada de rocas piroclasticas en función de su estructura en la zona de rodalquilar (Almeria

    Directory of Open Access Journals (Sweden)

    Leguey, S.

    1989-08-01

    Full Text Available Advanced-argillic alteration process is studied in different types of pyroclastic volcanic rocks: dacitic tuffs, riodacitic ignimbrites and andesitic agglomerates located in the Rodalquilar area (Almería, SE Spain. Tuffaceous material show massive alteration with vertical zonal patterns. In the lower zones silicification and propylitization processes (quartz, chlorite, illite ± pyrite predominate and evolve into advanced-argillic paragenesses (illite, kaolinite ± alunite at intermediate zones and to a quartz-alunite rock in the upper rones. Ferrie aureolaes and limonitic crusts are developed between the intermediate and upper zones. Agglomeratic and ignimbritic rocks show similar a1teration arranged in a more complex fissural patterns probably related to the intense fracturation displayed in that materials. Fissural zones are characterized by the incidence of supergenic processes with an increase in the size, idiomorphism and crystallinity of quartz crystals. Zones of massive argillie a1teration with alunite show important contents in Cl (0.4%, while limonitic crusts and ferrie aureolaes concentrate Sb (30 ppm. and As (500 ppm.. The Arsenic is also concentrated in quartz levels (80 ppm.. A genetic model related to sea water hydrothermal flow in a «hot spring» environment is discussed: The influence of weathering and supergenic processes in the redistribution of some analyzed minor elements (Cl, As, and Sb and Fe is discussed toghether with the evolution in morphology and crystallinity of siliceous minerals.Se han estudiado diferentes procesos de alteración argílica avanzada en tobas dacíticas, ignimbritas riodacíticas y aglomerados andesíticos, observándose el desarrollo de procesos supergénicos posteriores que destacan por su influencia en la modificación de la cristalinidad y hábito de las fases silíceas y ferruginosas primarias. En los materiales tobáceos se desarrollan alteraciones masivas zonadas en la vertical. En

  16. Applications of the surface enhanced Raman scattering (SERS)

    International Nuclear Information System (INIS)

    Picquart, M.; Haro P, E.; Bernard, S.

    2007-01-01

    Full text: Vibration spectroscopy techniques are used for many times to identify substances, determine molecular structure and quantify them, independently of their physical state. Raman spectroscopy as infrared absorption permit to access the vibration energy levels of molecules. In the second case, the permanent dipolar moment is involved while in the first one it is the polarizability (and the induced dipolar moment). Unfortunately, the classical Raman spectroscopy is low sensitive in particular in the case of biological molecules. On the opposite, the surface enhanced Raman spectroscopy (SERS) offers great potentialities. In this case, the molecules are adsorbed on a rough surface or on nanoparticles of gold or silver and the: signal can be increased by a factor of 10 7 to 10 8 . Moreover, the spectral enhancement is greater for the vibrations of the functional group of the molecule adsorbed on the substrate. In this work, we present the main theoretical bases of SERS, and some results obtain on different systems. (Author)

  17. Synthesis, characterization and SERS activity of biosynthesized silver nanoparticles

    Science.gov (United States)

    Bindhu, M. R.; Sathe, V.; Umadevi, M.

    2013-11-01

    Silver nanoparticles were rapidly synthesized using Moringa oleifera flower extract as the reducing agent shows surface plasmon resonance peak at 439 nm. The size and shape of the nanoparticles controlled by varying the concentration of M. oleifera flower extract in the reaction medium. The synthesized silver nanoparticles were well-dispersed spherical nanoparticles with the average size of 14 nm. The retinoic acid present in M. oleifera flower extract used as reducing agent and proteins was responsible for capping of the bioreduced silver nanoparticles. The obtained nanoparticle shows size-dependent SERS activity. The SERS spectrum indicates that the pyridine adsorbed on the silver surface in a stand-on orientation via its nitrogen lone pair electrons.

  18. Patchy silica-coated silver nanowires as SERS substrates

    Energy Technology Data Exchange (ETDEWEB)

    Hunyadi Murph, Simona E.; Murphy, Catherine J.

    2013-05-08

    We report a class of core-shell nanomaterials that can be used as efficient surface-enhancement Raman scattering (SERS) substrates. The core consists of silver nanowires, prepared through a chemical reduction process, that are used to capture 4- mercaptobenzoic acid (4-MBA), a model analyte. The shell was prepared through a modified Stöber method and consists of patchy or full silica coats. The formation of silica coats was monitored via transmission electron microscopy, UV-visible spectroscopy and phase-analysis light scattering for measuring effective surface charge. Surprisingly, the patchy silica coated silver nanowires are better SERS substrate than silver nanowires; nanomolar concentration of 4-MBA can be detected. In addition, “nano-matryoshka” configurations were used to quantitate/explore the effect of the electromagnetic field at the tips of the nanowire (“hot spots”) in the Raman scattering experiment.

  19. Development of a SERS aptasensor for detection of medical residues

    DEFF Research Database (Denmark)

    Frøhling, Kasper Bayer

    surface. By hybridisation to a labelled complementary strand it was proven that aptamer was indeed immobilised. It was also found that stronger binding to the gold covered nanopillars could be obtained by a short treatment in reactive O2 plasma. Likewise it was found that the addition of a detergent......Low levels of medical residues in environmental, industrial and domestic water systems is a growing concern. The biosensor industry is trying to accomodate the need of sensitive and specific sensor systems capable of ultra-low level detection of medical residues. In this PhD project a surface...... enhanced Raman spectroscopy (SERS) sensor for the female sexhormone 17β-estradiol was attempted. It is commonly used in contraceptive pills from where it find its way through waste water treatment plants and into the environment. The SERS substrate was fabricated in a cleanroom facility using techniques...

  20. Advanced Gas Sensors Using SERS-Activated Waveguides

    Science.gov (United States)

    Lascola, Robert; McWhorter, Scott; Murph, Simona Hunyadi

    2010-08-01

    This contribution describes progress towards the development and testing of a functionalized capillary that will provide detection of low-concentration gas-phase analytes through SERS. Measurement inside a waveguide allows interrogation of a large surface area, potentially overcoming the short distance dependence of the SERS effect. The possible use of Raman spectroscopy for gas detection is attractive for IR-inactive molecules or scenarios where infrared technology is inconvenient. However, the weakness of Raman scattering limits the use of the technique to situations where low detection limits are not required or large gas pressures are present. With surface-enhanced Raman spectroscopy (SERS), signal enhancements of 106 are often claimed, and higher values are seen in specific instances. However, most of the examples of SERS analysis are on liquid-phase samples, where the molecular density is high, usually combined with some sort of sample concentration at the surface. Neither of these factors is present in gas-phase samples. Because the laser is focused to a small point in the typical experimental setup, and the spatial extent of the effect above the surface is small (microns), the excitation volume is miniscule. Thus, exceptionally large enhancements are required to generate a signal comparable to that obtained by conventional Raman measurements. A reflective waveguide offers a way to increase the interaction volume of the laser with a SERS-modified surface. The use of a waveguide to enhance classical Raman measurements was recently demonstrated by S.M. Angel and coworkers, who obtained 12- to 30-fold sensitivity improvements for nonabsorbing gases (CO2, CH4) with a silvered capillary (no SERS enhancement). Shi et al.. demonstrated 10-to 100-fold enhancement of aqueous Rhodamine 6G in a capillary coated with silver nanoparticles. They observed enhancements of 10- to 100-fold compared to direct sampling, but this relied on a "double substrate", which required

  1. Development of a SERS aptasensor for detection of medical residues

    OpenAIRE

    Frøhling, Kasper Bayer; Jakobsen, Mogens Havsteen; Boisen, Anja; Bache, Michael

    2015-01-01

    Low levels of medical residues in environmental, industrial and domestic water systems is a growing concern. The biosensor industry is trying to accomodate the need of sensitive and specific sensor systems capable of ultra-low level detection of medical residues. In this PhD project a surface enhanced Raman spectroscopy (SERS) sensor for the female sexhormone 17β-estradiol was attempted. It is commonly used in contraceptive pills from where it find its way through waste water treatment plants...

  2. Design and Preparation of Nanoparticle Dimers for SERS Detection

    Science.gov (United States)

    2012-09-10

    illustration of the antibody functionalized antitags. (b) SERS-based ELISA-analog detection. Human α-thrombin (Thr) antigen (yellow) is exposed to...Schaeffer,  H.  Kolcker,  W.  Horninger,  G.   Bartsch ,  C.  A.  Mirkin,  Proc.   Natl.  Acad.  Sci.  U.S.A.   2009

  3. Ser649 and Ser650 are the major determinants of protein kinase A-mediated activation of human hormone-sensitive lipase against lipid substrates

    DEFF Research Database (Denmark)

    Krintel, Christian; Osmark, Peter; Larsen, Martin Rask

    2008-01-01

    Hormone-sensitive lipase (HSL) is a key enzyme in the mobilization of fatty acids from stored triacylglycerols. Its activity is regulated by reversible protein phosphorylation. In rat HSL Ser563, Ser659 and Ser660 have been shown to be phosphorylated by protein kinase A (PKA) in vitro as well...

  4. La polémica sobre el ser en el Avicena y Averroes latinos

    OpenAIRE

    García-Marqués, A. (Alfonso)

    1987-01-01

    Fiosofía medieval; recepción del aristotelismo árabe en Occidente; metafísica; aristotelismo platonizante; esencia; universal; accidentalidad del ser; ser y esencia; ser veritativo y ser extramental; crítica de Averroes a Avicena.

  5. Leucipo, Demócrito e Kant: uma Reflexão sobre a Equivalência entre Ser e Não-Ser

    Directory of Open Access Journals (Sweden)

    Eberth Eleuterio dos Santos

    2015-08-01

    Full Text Available De início, apresentaremos a tese de Demócrito e Leucipo, segundo a qual o ser não é mais que o não-ser, tendo como contraponto o pensamento eleata acerca da inexistência necessária do não-ser. Esta discussão nos remete à oposição entre o pleno (cheio e o vazio que será posteriormente traduzida na oposição entre o ser e o nada (ou o não-ser. Desse modo, a oposição entre o pleno e o vazio é uma oposição que se desloca para o ser e o não-ser. Em seguida, faremos a apreciação do escrito pré-crítico kantiano Ensaio para introduzir em filosofia o conceito de grandeza negativa, no qual distinguimos certo tipo de oposição tomada entre grandezas em geral que, acreditamos, poderia ser interpretado como estando de acordo com o posicionamento de Demócrito e Leucipo sobre o estatuto ontológico do não-ser como princípio equivalente ao ser, e não como sua contradição em sentido puramente lógico.

  6. SERS OF BACTERIORHODOPSIN WITH OUT-DIFFUSED SILVER NANOISLANDS

    Directory of Open Access Journals (Sweden)

    H. Fabian

    2014-09-01

    Full Text Available We present the studies on surface-enhanced Raman spectroscopy (SERS of bacteriorhodopsin in purple membranes using self-assembled silver nanoisland films for Raman signal enhancement. These metal island films were fabricated on soda-lime glass slides subjected to silver-sodium ion exchange in molten Ag0.05Na0.95NO3 at the temperature of 325°C for 20 minutes and subsequent treatment in hydrogen atmosphere at the temperature of 250°C for 10 minutes. The films typically consisted of 20–30 nm closely placed nanoislands. Being tested as SERS substrates for rhodamine 6G the nanoisland films gave the possibility to observe respective characteristic Raman lines from a dried drop of rhodamine 6G dissolved in water in the concentration of 10–6 M. Similarly fabricated substrates were used to obtain SERS spectra of bacteriorhodopsin in purple membranes dispersed in water, and Raman peaks at 1000–1020 cm–1, 1150–1220 cm–1 and 1530– 1570cm–1 were resolved. The substrates made it possible to register characteristic Raman peaks only for an order of magnitude lower concentration of bacteriorhodopsin in contrast to the virgin glass substrate, that is the enhancement of Raman signal was considerably less than for rhodomin 6G. This is supposed to be due to bacteriophodopsin molecules packing in patches, and it prevents bacteriophodopsin in purple membranes from penetration between the nanoislands where the local enhancement of the electric field of exciting light wave is maximal.

  7. La suspensión de la Diálisis en pacientes con Insuficiencia Renal Crónica Avanzada: ¿qué opinan los enfermos?

    Directory of Open Access Journals (Sweden)

    Iñaki Saralegui

    Full Text Available El proceso de voluntades anticipadas permite a los pacientes dar a conocer sus preferencias. Método: estudio cualitativo de subgrupos homogéneos con pacientes con enfermedad renal crónica en programa de diálisis a través de entrevistas semiestructuradas, con el objetico de conocer su deseo de participar en la toma de decisiones sanitarias, en particular las relacionadas con el final de la vida. Resultados: de mayo a diciembre de 2012 se entrevistaron a catorce pacientes, con una mediana de edad de 66 años. Creen que reciben una información adecuada, pero reconocen que no se les habla sobre el final de la vida o la retirada de diálisis. Creen que los médicos no hablan de ello porque están centrados en otras cuestiones y no quieren entristecerles. Quieren participar en la toma de decisiones y expresar sus preferencias. En caso de deterioro neurológico severo preferirían suspender la diálisis y recibir tratamiento para no tener dolor, en su casa si es posible. Sería conveniente integrar los cuidados paliativos en la asistencia de los pacientes en diálisis.

  8. Development of an optofluidic SERS-based biomedical sensor

    Science.gov (United States)

    Walton, Brian; Huang, Po-Jung; Kameoka, Jun; Deutz, Nicolaas; Coté, Gerard L.

    2016-03-01

    Rapid assessment of radiation exposure to sensitive organs like the gut is extremely important for large populations exposed to ionized radiation, for instance during warfare. Recent results have shown that plasma citrulline levels appear to track gut function after irradiation levels in mice and humans. The current ways to monitor blood citrulline levels are bulky, laborious, time-consuming and expensive methods. Therefore, an optofludic point-of-care (POC) system using surface enhanced Raman spectroscopy to measure plasma citrulline as a marker for radiation exposure that overcomes the above issues is being developed. As a first step toward development of this system four colloidal nanoparticles, spherical gold, silver cubes, silica-gold nanoshells, and silver-gold nanocages have been analyzed for use in the POC system. Transmission electron microscopy (TEM) images have been taken of each nanoparticle to visualize the morphology of the nanoparticles, which is vital for SERS. Ultraviolet-visible (UV/Vis) spectroscopy was also collected to verify the extinction spectra for each nanoparticle was in resonance with the excitation wavelength. The nanoparticles were functionalized with mercaptobenzoic acid (MBA), a Raman reporter molecule, and SERS spectra were collected to determine which has better utility in a novel micro-to-nanochannel. The data showed that the silver nanocubes have a larger enhancement factor than the gold nanospheres, nanoshells, or nanocages. Currently, these nanocubes are being functionalized with the citulline for assessing the concentration sensitivity and dynamic range for ultimate use as a marker for radiation.

  9. LAS CONSECUENCIAS JURÍDICAS DE NO SER UNA PROVINCIA*

    Directory of Open Access Journals (Sweden)

    Leonardo Hugo Limanski

    2015-09-01

    Full Text Available En el presente trabajo se analiza, en forma profunda, la autonomía de la Ciudad Autónoma de Buenos Aires, en comparación con las 23 provincias argentinas. A su vez, se intentará demostrar que la Ciudad de Buenos Aires debe ser tratada en forma equivalente a una provincia, desarrollando los problemas que la interpretación actual de la Constitución Nacional por parte de la Corte Suprema acarrea. A los efectos de lograr una cabal comprensión del tema se realizará una breve reseña histórica partiendo desde la federalización en el año 1880, y se hará hincapié en aquellos temas que, creo, violan la igualdad. Es así que se pondrán de manifiesto cuales son las consecuencias jurídicas de no ser considerada una provincia y, por último, se realizará una aproximación al vínculo existente entre las comunas y los municipios, a efectos de dejar planteado un problema

  10. ROTATION AND GRANULATION OF THE K2 GIANT α SER

    Energy Technology Data Exchange (ETDEWEB)

    Gray, David F., E-mail: dfgray@uwo.ca [Department of Physics and Astronomy University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada)

    2016-07-20

    The red giant α Ser was observed over 10 seasons, 2001–2010, at the Elginfield Observatory with the high-resolution coudé spectrograph. Season-mean radial velocities appear to show a small secular rise ∼11 ± 3 m s{sup 1} yr{sup 1}. The absolute spectroscopic radial velocity with convective blueshifts taken into account is 2730 m s{sup 1}. Ten line-depth ratios were investigated and show that the star's temperature is constant with any secular variation below 1.3 ± 1.0 K over the 11 years of observation. Fourier analysis of the line broadening yields v sin i = 2.0 ± 0.3 km s{sup 1} and a radial-tangential macroturbulence dispersion ζ {sub RT} = 4.50 ± 0.10 km s{sup 1}. The third-granulation-signature plot shows that the granulation velocities of α Ser are only 0.55 ± 0.10 as large as the Sun's. The line bisector of Fe i λ 6253 has the usual “C” shape and when mapped onto the third-signature plot results in a flux deficit that is slightly broader than seen in other measured K giants. The deficit fractional area of 12.3 ± 1.5% suggests a temperature difference between granules and lanes of 105 K as seen averaged over the stellar disk.

  11. Análisis cualitativo de las competencias para la especialidad de Enfermería Familiar y Comunitaria. Construyendo el camino hacia la enfermería clínica avanzada.

    Directory of Open Access Journals (Sweden)

    Á́ngeles Arias-Rodríguez

    2012-08-01

    Full Text Available Las competencias a adquirir en la especialidad de Enfermería Familiar y Comunitaria se establecen en la Orden SAS/1729/2010. El objetivo principal del estudio es conocer su distribución más apropiada para la formación. Entendiendo la enfermería clínica avanzada como una profesión centrada en las necesidades de cuidados de los pacientes, las familias y la comunidad, cuya práctica clínica se basa en la evidencia, en el uso del método clínico, y en el uso de técnicas de intervención complejas, mediante un enfoque holístico de la salud. Para ello se eligen dos técnicas cualitativas: grupos focales y la técnica semicualitativa Delphi. El resultado principal permite decidir que competencias alcanzar, en cada curso de la especialidad. Objetivo principal: Analizar el contenido y la distribución de las competencias que establece la orden SAS/1729/2010, de 17 de junio para la especialidad de EFyC.

  12. Tunable plasmon resonance nanostructures: SERS application in wines identification

    International Nuclear Information System (INIS)

    Serra, A.; Manno, D.

    2013-01-01

    A real-time and sensitive methodology has been developed and optimized to detect water-soluble molecules by surface-enhanced Raman spectroscopy (SERS). Silver nanoparticles were synthesized by using erytrithol and fructose as capping and reducing agents, respectively. The proposed method can be successfully applied to solve problems and obtain optimal Raman spectra also from organic dyes or specific phenolic compounds highly fluorescent. In this work we illustrate the potentiality of the methodology applying it to the characterization of red wine, which, as we know, it is very difficult to be analyzed by Raman spectroscopy precisely because of the strong fluorescence of the phenolic compounds that give red wine its typical and popular features.

  13. Nanofabrication of SERS Substrates for Single/Few Molecules Detection

    KAUST Repository

    Melino, Gianluca

    2015-05-04

    Raman spectroscopy is among the most widely employed methods to investigate the properties of materials in several fields of study. Evolution in materials science allowed us to fabricate suitable substrates, at the nanoscale, capable to enhance the electromagnetic field of the signals coming from the samples which at this range turn out to be in most cases singles or a few molecules. This particular variation of the classical technique is called SERS (Surface Enanched Raman Spectroscopy). In this work, the enhancement of the electromagnetic field is obtained by manipulation of the optical properties of metals with respect to their size. By using electroless deposition (bottom up technique), gold and silver nanoparticles were deposited in nanostructured patterns obtained on silicon wafers by means of electron beam lithography (top down technique). Rhodamine 6G in aqueous solution at extremely low concentration (10-8 M) was absorbed on the resultant dimers and the collection of the Raman spectra demonstrated the high efficiency of the substrates.

  14. Identidades en flujo, diversas maneras de ser colombianos

    Directory of Open Access Journals (Sweden)

    Omar Rincón

    2015-05-01

    Full Text Available La televisión es todo esto porque es lo más común que tenemos entre los colombianos: es un pegante cultural para un país de identidades juntas pero no revueltas. La televisión se ha convertido en el marco de referencia cultural de la mayoría para comprender sus vidas. El maestro Jesús Martín-Barbero en su libro Televisión y melodrama (1992 lo expresa bien cuando escribe que “en medio del desgarramiento que vive el país ¡el fútbol y la telenovela pueden llegar a ser una de las pocas maneras como los colombianos nos sentimos juntos!”. Fútbol, televisión, música y humor son las prácticas más importantes para juntar y conectar a los colombianos.

  15. FKBP51 regulates decidualization through Ser473 dephosphorylation of AKT.

    Science.gov (United States)

    Wei, Muyun; Gao, Ying; Lu, Bingru; Jiao, Yulian; Liu, Xiaowen; Cui, Bin; Hu, Shengnan; Sun, Linying; Mao, Shaowei; Dong, Jing; Yan, Lei; Chen, Zijiang; Zhao, Yueran

    2018-03-01

    Defective decidualization of human endometrial stromal cells (ESCs) has recently been highlighted as an underlying cause of implantation failure. FK-506-binding protein 51 (FKBP51) has been shown to participate in the steroid hormone response and the protein kinase B (AKT) regulation process, both of which are important pathways involved in decidualization. The objective of the present study was to investigate the potential effects and mechanisms of FKBP51 in the regulation of ESC decidualization. By performing immunohistochemical staining on an endometrial tissue microarray (TMA) derived from normal females, we found that FKBP51 expression was much higher in the luteal phase than in the follicular phase in ESCs. Primary ESCs were isolated from patients to build an in vitro decidualization model through co-culture with medroxyprogesterone acetate (MPA) and 8-bromoadenosine (cAMP). SC79, a specific AKT activator in various physiological and pathological conditions, and shRNA-FKBP51 were used to examine the roles of AKT and FKBP51 in decidualization. The Western blot and RT-PCR results showed that FKBP51, insulin-like growth factor-binding protein 1 (IGFBP1) and prolactin (PRL) expression increased in ESCs treated with MPA + cAMP; meanwhile, the level of p-Ser473 AKT (p-S473 AKT) decreased and forkhead box protein O1 (FOXO1A) expression increased. Decidualization was inhibited by the AKT activator SC79 and the transfection of FKBP51-shRNA by affecting protein synthesis, cell morphology, cell growth and cell cycle. Furthermore, this inhibition was rescued by FKBP51-cDNA transfection. The results supported that FKBP51 promotes decidualization by reducing the Ser473 phosphorylation levels in AKT. © 2018 Society for Reproduction and Fertility.

  16. Ser excepción o del individualismo.

    Directory of Open Access Journals (Sweden)

    Juan Fernando Pérez.

    1998-06-01

    Full Text Available Lección inaugural de la Maestría en Ciencias Sociales: Psicoanálisis, Cultura y Vínculo social. A partir del texto de Freud Los seres excepcionales (también traducido Las excepciones el autor interroga una categoría no psicoanalítica como es la de individualismo, con el concepto de Freud allí expuesto. Propone que el concepto freudiano ser excepción, permite pensar al menos algunas dimensiones de la fenomenología descrita bajo la categoría de individualismo, hecho de interés particular para el examen de algunas modalidades del malestar contemporáneo y de la naturaleza del vínculo social que ese mundo propone. En este orden de ideas aparece cómo las dos figuras que Freud define al lado de “las excepciones”, es decir “los delincuentes por sentimientos de culpa” y “los que fracasan al triunfar”, tienden a desdibujarse en las sociedades de hoy, en favor de una mayor significación esta forma singular de individualismo como es la de “ser excepción”. El hecho revela en forma bien específica cómo el declinamiento de padre en la época de la ciencia implica el fortalecimiento de la tendencia particular del sujeto contemporáneo de definirse como excepción frente a la ley.

  17. Desarrollo de tecnologías de Avanzada para la producción de Fármacos: Análisis Informétrico

    Directory of Open Access Journals (Sweden)

    Dayami Laza Loaces

    2001-12-01

    Full Text Available El desarrollo significativo que ha presentado en las últimas décadas del siglo la Industria Farmacéutica, muestra un marcado interés por investigadores e instituciones científicas en el diseño de medicamentos, con un alcance rápido de un nivel terapéutico efectivo del fármaco en un tiempo breve, que dure desde la recuperación total del paciente hasta la eliminación completa de los síntomas que se quieren suprimir. Se realizó un análisis informétrico sobre las tendencias de investigación en la temática durante los últimos años y para ello se utilizó la información que sobre el tema existe en las bases de datos International Pharmaceutical Abstract y Medline. Estas 2 bases contienen información bibliográfica sobre farmacia, medicina, farmacología, toxicología, etc., susceptible de ser analizada por medios automatizados. Se obtuvo como resultado, después de un análisis minucioso sobre la relevancia de los artículos, una base de datos con 2 855 registros.The significant development of the Pharmaceutical Industry during the last decades shows the marked interest of researchers and scientific institutions in the drug design, which reaches fast an effective therapeutic level of the drug in a short time and that lasts from the total recovery of the patient to the complete elimination of the symptoms. An informetric analysis of the trends of research on this topic during the last years was made by using the information existing on the International Pharmaceutical Abstract and on the Medline databases. These 2 databases contain bibliographic information on pharmacy, medicine, pharmacology, toxicology, etc., that may be analyzed by automated means. After a detailed analysis on the relevance of the articles, a database of 2 855 entries was obtained.

  18. Sandwich-like layer-by-layer assembly of gold nanoparticles with tunable SERS properties

    Directory of Open Access Journals (Sweden)

    Zhicheng Liu

    2016-07-01

    Full Text Available Sandwich-like layer-by-layer thin films consisting of polyelectrolytes and gold nanoparticles were utilized to construct surface-enhanced Raman scattering (SERS substrates with tunable SERS properties. It is found that both the size of the nanoparticles in the layers and the interlayer distance significantly influence the SERS performance of the multilayered thin film. These simple, low-cost, easily processable and controllable SERS substrates have a promising future in the field of molecular sensing.

  19. Rough surface Au@Ag core-shell nanoparticles to fabricating high sensitivity SERS immunochromatographic sensors.

    Science.gov (United States)

    Fu, Qiangqiang; Liu, Hongwu Liu; Wu, Ze; Liu, An; Yao, Cuize; Li, Xiuqing; Xiao, Wei; Yu, Shiting; Luo, Zhi; Tang, Yong

    2015-11-14

    Immunochromatographic sensors (ICSs) are inexpensive, simple, portable, and robust, thus making ICSs commonplace in clinical diagnoses, food testing, and environmental monitoring. However, commonly used gold nanoparticles (AuNPs) ICSs have low sensitivity. Therefore, we developed highly sensitive surface enhanced Raman scattering (SERS) ICSs. To enhance the sensitivity of SERS ICSs, rough surface core-shell Au@Ag nanoparticles (RSAu@AgNPs) were prepared by coating silver on the surface of gold nanoflowers (AuNFs). Then these nanoparticles were used as SERS substrate in the SERS ICSs, after which the SERS ICSs were implemented to detect haemoglobin and heavy metal cadmium ion (Cd(2+)). The limit of detection (LOD) of the SERS ICSs for detecting haemoglobin was 8 ng/mL, and the linear range of the SERS ICSs was from 31.3 to 2000 ng/mL. The LOD of the SERS ICSs for detecting Cd(2+) was 0.05 ng/mL and the linear analysis range was from 0.05 to 25 ng/mL. The cross reactivity of the SERS ICSs was studied and results showed that the SERS ICSs exhibited highly specific for detection of haemoglobin and Cd(2+), respectively. The SERS ICSs were then used to detect haemoglobin (spiked in serum and in stool) and Cd(2+) (spiked in tap water, river water, and soil leaching water), and the results showed high recovery. These characteristics indicated that SERS ICSs were ideal tools for clinical diagnosis and environmental pollution monitoring.

  20. ¿PERMITE SER FELIZ LA MORAL CRISTIANA?

    Directory of Open Access Journals (Sweden)

    Waldo Romo P

    2006-01-01

    Full Text Available La pregunta que encabeza el artículo ya es desafiante: "¿Permite ser feliz la moral cristiana?". Existe la posibilidad de responder negativamente. El autor, después de analizar algunos pensadores (Nietzsche, entre ellos que han negado a la moral cristiana la posibilidad de hacer feliz al ser humano, presenta las condiciones de posibilidad para que dicha moral se encauce a ser un camino de felicidad. Entre esas condiciones se destaca: el paso de una moral heterónama a una moral de autonomía teónoma, una moral centrada en la persona más que una moral centrada en la ley, una moral de discipulado que pone primero el amor y luego el cumplimiento normativo. Profundiza, al respecto, en el logion de Jesucristo: "El que me ama, cumple mis mandamientos". Esta enseñanza plantea el orden secuencial de toda moral cristiana: porque se ama a Jesús, se entiende el cumplimiento de las normas. Estas se transforman, entonces, en el "test" verificador del amor. De lo contrario, se permanece en un ritualismo normativo, que en defintiva hastía y no lleva a la felicidad. Por ello, el artículo profundiza en una moral de opción fundamental expresada en actitudes y actos morales coherentes con esa opción. Si las condiciones de posibilidad propuestas se llegan a dar, la interrogante que organiza el artículo tendrá una respuesta positivaThe question that heads this article is already challenging: "Does Christian morality permit one to be happy?" The possibility of responding negatively exists. The author, after analyzing the contributions of some thinkers (Nietszche among them who have denied the possibility that Christian morality could make human beings happy, presents the conditions that would orient said morality towards the possibility of becoming a path to happiness. Among those conditions, the author highlights: the passage from a "heteronomous" morality to a morality of "theonomous" autonomy, a morality centered on the person rather than a morality

  1. "Ser diferente é normal?"/"Being different: is it normal?"

    Directory of Open Access Journals (Sweden)

    Viviane Veras

    2007-01-01

    Full Text Available A pergunta título deste trabalho retoma o slogan “Ser diferente é normal”, que é parte da campanha criada para uma organização não-governamental que atende portadores de Síndrome de Down. O objetivo é a inclusão social da pessoa com deficiência e o primeiro passo foi propor a inclusão de um grupo de diferentes no grupo dito normal. No vídeo de lançamento da campanha, o diferente, identificado como normal, é mostrado por meio de exemplos – um negro com cabelo black-power, um skin-head, um corpo tatuado, um corpo feminino halterofílico, uma família hippie, uma garota com síndrome de Down. A visão da adolescente dançando reduz, de certo modo, o efeito imaginário que vai além da síndrome, uma vez que apenas o corpo com seus olhinhos puxados se destacam, e não se interrogam questões cognitivas. Minha proposta é refletir sobre o estatuto paradoxal do exemplo, tal como é trabalhado nesse vídeo: se, por definição, um exemplo mostra de fato seu pertencimento a uma classe, pode-se concluir que é exatamente por ser exemplar que ele se encontra fora dela, no exato momento em que a exibe e define. The question in the title of this paper refers to the slogan "ser diferente é normal" ("It´s normal to be different", which is part of a campaign created for a NGO that supports people with Down syndrome. The objective of the campaign is to promote the social inclusion of individuals with Down syndrome, and the first step was to propose the inclusion of a group of "differents" in the so-called normal group. The film launching the campaign shows the different identified as normal by means of examples: a black man exhibiting blackpower haircut, a skin-head, a tattooed body, an over-athletic female body, a hippie family and a girl with Down syndrome. The vision of the dancing teenager lessens the imaginary effect that surpasses the syndrome, since only her body and her little oriental eyes stand out and no cognitive issues are

  2. Técnicas de avanzada en el diagnóstico patológico de edificaciones:: "El Templete" de la Habana Vieja Advanced techniques in building pathology diagnosis:: "El Templete" of Old Habana

    Directory of Open Access Journals (Sweden)

    José Armando Chávez Hernández

    2012-08-01

    Full Text Available En el lugar exacto donde se fundó la Villa de San Cristóbal de La Habana, se levanta un monumento que semeja un pequeño templo de la Grecia antigua: El Templete. Esta importante edificación de la ciudad ha estado sufriendo de lesiones estructurales poco comunes para un inmueble de estas características: pequeña, de una estructura robusta, materiales adecuados, buena ejecución, y por tanto de una excelente estabilidad estructural. Varias intervenciones no han podido evitar que vuelvan a aparecer estas lesiones estructurales, por lo que se hizo necesario un estudio de mayor complejidad y utilizando técnicas más avanzadas, que permitieran llegar a conocer las verdaderas causas de los daños. En este trabajo se expone el procedimiento que se ha seguido para llegar a un diagnóstico sobre bases científicas, que es el soporte para realizar el proyecto de intervención y recuperación del inmueble.Exactly in the same place where the Villa of San Cristóbal of Havana was founded, a monument that look like a small temple from Ancient Greece rises: The Templete. This important building of the city has been suffering unusual structural lesions for a construction with those characteristics: small, robust construction, suitable materials, proper execution, and therefore an excellent structural stability. Several interventions have failed to prevent reappearance of structural lesions, that is why it became necessary a more complex study and the use of more advanced techniques, which allow to get to know the true causes of the damage. This paper outlines the procedure to be followed to arrive at a diagnosis on a scientific basis, which is the main support for the proposed intervention and recovery project of the property.

  3. Tecnologías avanzadas de manufactura en países en vías de desarrollo: una comparación entre Costa Rica y México

    Directory of Open Access Journals (Sweden)

    Carlos Mora Monge

    2006-05-01

    Full Text Available Hoy, para los países en vías de desarrollo es crítico asegurar sus capacidades de manufactura para poder competir globalmente, en especial cuando hay tratados de libre comercio que se están negociando. Esto es particularmente importante para países como Costa Rica, el cual tiene un tratado de libre comercio con México y está en proceso de aprobación del tratado de libre comercio con los Estados Unidos (CAFTA, por sus siglas en inglés. Mucho se ha dicho sobre si Costa Rica está listo para firmar el tratado. Este artículo provee puntos de vista desde una perspectiva de manufactura y examina las diferencias en inversiones de tecnologías avanzadas de manufactura (AMT, por sus siglas in inglés y las barreras de implementación entre empresas mexicanas y costarricenses. Después de haber hecho una extensiva investigación sobre AMT en la literatura, dos preguntas de investigación se formularon con respecto a las diferencias entre ambos países. Usando una metodología en forma de cuestionario, la información se recolectó entre 125 empresas, 85 mexicanas y 40 costarricenses. Para probar la hipótesis planteada, se usó el análisis ANOVA (análisis de varianza. Los resultados indican que hay diferencias entre algunas tecnologías y barreras de implementación de AMT entre ambos países.

  4. Alimentación del paciente de cáncer en fase avanzada y terminal: consideraciones éticas y recomendaciones prácticas Ethical and practical recommendations: How to food terminal and advanced stage cancer patents

    Directory of Open Access Journals (Sweden)

    Ángela J Suárez Pérez

    2006-08-01

    Full Text Available El objetivo fundamental del tratamiento al paciente de cáncer en fase avanzada y terminal es alcanzar la mejor calidad de vida posible. Para ello se requiere una atención integral cuya base científica, filosófica y ética preserve, en el final de la vida, la dimensión humana. La eficiencia y eficacia de la atención depende de cuanto se adapte a las peculiaridades y condiciones concretas de cada paciente. Entre los síntomas que inciden con mayor frecuencia en estos pacientes se encuentra la anorexia, la que tiene consecuencias no sólo físicas sino que afecta otras esferas de la vida personal del enfermo. Se exponen las posibles causas de la anorexia, se plantean algunas consideraciones éticas en torno a la alimentación de estos pacientes y se brindan recomendaciones prácticas encaminadas a lograr un manejo adecuado de la alimentación que contribuya a mantener una calidad de vida aceptable en esta etapa de la vida.The main objective of the treatment to the cancer patient in advanced and terminal phases is to reach to the possible best quality of life. For this an integral attention is required, which scientific, philosophical and ethics base preserves, in the end of life, the human dimension. The efficiency and effectiveness of attention depends on how much attention is adapted to each patient's peculiarities and concrete conditions. Among the symptoms that more frequently impact in this patients is the anorexia, that not only carries physical consequences, but rather it anorexia are exposed, some ethical considerations around the feeding of these patients and practical recommendations are offered, guided to achieve an appropriate handling of the feeding that contributes to maintain an acceptable quality of life in this stage

  5. SERS of semiconducting nanoparticles (TIO{sub 2} hybrid composites).

    Energy Technology Data Exchange (ETDEWEB)

    Rajh, T.; Musumeci, A.; Gosztola, D.; Schiller, T.; Dimitrijevic, N. M.; Mujica, V.; Martin, D.; Center for Nanoscale Materials

    2009-05-06

    Raman scattering of molecules adsorbed on the surface of TiO{sub 2} nanoparticles was investigated. We find strong enhancement of Raman scattering in hybrid composites that exhibit charge transfer absorption with TiO{sub 2} nanoparticles. An enhancement factor up to {approx}10{sup 3} was observed in the solutions containing TiO{sub 2} nanoparticles and biomolecules, including the important class of neurotransmitters such as dopamine and dopac (3,4-dihydroxy-phenylacetic acid). Only selected vibrations are enhanced, indicating molecular specificity due to distinct binding and orientation of the biomolecules coupled to the TiO{sub 2} surface. All enhanced modes are associated with the asymmetric vibrations of attached molecules that lower the symmetry of the charge transfer complex. The intensity and the energy of selected vibrations are dependent on the size and shape of nanoparticle support. Moreover, we show that localization of the charge in quantized nanoparticles (2 nm), demonstrated as the blue shift of particle absorption, diminishes SERS enhancement. Importantly, the smallest concentration of adsorbed molecules shows the largest Raman enhancements suggesting the possibility for high sensitivity of this system in the detection of biomolecules that form a charge transfer complex with metal oxide nanoparticles. The wavelength-dependent properties of a hybrid composite suggest a Raman resonant state. Adsorbed molecules that do not show a charge transfer complex show weak enhancements probably due to the dielectric cavity effect.

  6. Juan O’Gorman. Formas de no ser arquitecto

    Directory of Open Access Journals (Sweden)

    Javier Jerez González

    2015-12-01

    Full Text Available La obra proyectada y construida por Juan O’Gorman a lo largo de su vida traza un recorrido largo y sincopado entre formas de entender la arquitectura totalmente antagónicas. Su primera etapa de radical racionalismo desarrolla, según procedimientos estrictamente técnicos, un lenguaje revolucionario basado en la austeridad y la precisión. A pesar de ello muchas de sus obras destacan por la plasticidad de sus composiciones volumétricas, la riqueza espacial o, incluso, por la creación de atmósferas oníricas. Los primeros años de frenética actividad dan paso a un periodo de voluntario alejamiento de la práctica profesional de la arquitectura: ni una sola obra, ni un solo proyecto durante cerca de 15 años. Tan solo su actividad docente le mantiene en contacto con el mundo de la arquitectura. Cuando Juan O’Gorman vuelve a ejercer como arquitecto, lo hace construyendo algunos de los iconos del movimiento de integración plástica de México: la biblioteca central de la UNAM y su casa en San Jerónimo. A pesar de las enormes diferencias, o más bien oposiciones, entre unos momentos y otros, puede identificarse una invariante clara como señal de identidad personal: una velada voluntad de no ser arquitecto

  7. Fotografia: viajar, ver e ser visto na internet

    Directory of Open Access Journals (Sweden)

    Anabel S. Cavalcanti

    2011-02-01

    Full Text Available

    Este artigo pretende tratar da fotografia – especialmente turística – como meio de ver e ser visto, numa visão antropológica das Teorias da Imagem. O valor dado às memórias e à identidade familiar nos tradicionais álbuns de família é transferido à exposição virtual na rede mundial de computadores, facilitada pelas novas tecnologias. Mais do que aproveitar as viagens turísticas, na contemporaneidade se quer mostrar que viajou. E para isso não existe melhor caminho do que fotografar-se e exibir-se na internet.


  8. A microfluidic dialysis device for complex biological mixture SERS analysis

    KAUST Repository

    Perozziello, Gerardo

    2015-08-01

    In this paper, we present a microfluidic device fabricated with a simple and inexpensive process allowing rapid filtering of peptides from a complex mixture. The polymer microfluidic device can be used for sample preparation in biological applications. The device is fabricated by micromilling and solvent assisted bonding, in which a microdialysis membrane (cut-off of 12-14 kDa) is sandwiched in between an upper and a bottom microfluidic chamber. An external frame connects the microfluidic device to external tubes, microvalves and syringe pumps. Bonding strength and interface sealing are pneumatically tested. Microfluidic protocols are also described by using the presented device to filter a sample composed of specific peptides (MW 1553.73 Da, at a concentration of 1.0 ng/μl) derived from the BRCA1 protein, a tumor-suppressor molecule which plays a pivotal role in the development of breast cancer, and albumin (MW 66.5 kDa, at a concentration of 35 μg/μl), the most represented protein in human plasma. The filtered samples coming out from the microfluidic device were subsequently deposited on a SERS (surface enhanced Raman scattering) substrate for further analysis by Raman spectroscopy. By using this approach, we were able to sort the small peptides from the bigger and highly concentrated protein albumin and to detect them by using a label-free technique at a resolution down to 1.0 ng/μl.

  9. The frequency of genotypes for the SNP Ser/Ser in the studied population of Albanian women is higher in the Balkan region

    Directory of Open Access Journals (Sweden)

    Zafer Gashi

    2016-08-01

    Full Text Available In women undergoing natural cycles, just one oocyte is usually selected for ovulation, yet routine clinical techniques to support the development of multiple follicles using additional gonadotrophins result in numerous ovulations. Several parameters have been postulated as predictors of ovarian response (inhibin B, 17-β-estradiol and antiMüllerian hormone. Nevertheless, the FSH level on the day 3 of menstrual cycle remains, the most widely used biomarker due to its low cost, although, the genetic background of individuals seems to determine the response of patients to rFSH stimulation better than the stimulation design. Consequently, the variants of FSHR were explored and they may be involved in the role of FSH receptor in mediated signal transduction and with ovarian response in infertile women submitted to ovarian stimulation. In this study we examined, for the first time, the prevalence of genotype variants Asn680Ser in population Albanian women from Kosovo Dukagjin region who took part in IVF / ICSI program. The frequencies of the Asn680Ser genotype variants were as follows: Asn/Asn 22.1%, Asn/Ser 47.1%, and Ser/Ser 30.8%, respectively (Table 1. bE2 levels between the three genotype variants showed slight but statistically significant difference (p= 0.0308. No difference was also found between the genotype groups either in terms of AFC, amount of the FSH required for ovulation induction, stimulation length days, number of dominant follicles, oocyte retrieval number or endometrial thickness (Table 2. BMI was significantly higher in the Ser/Ser group as compared to those from the Asn/Ser or the Asn/Asn group (p= 0.0010 (Table 2. In the study population of Albanian women Dukagjin region of Kosovo had a higher incidence of Ser / SER genotype compared to Asn / Asn genotype. Our research results in the Albanian population differ from published data for other ethnic groups in the Balkans.

  10. We are European Citizens. Jugar para aprender a ser europeos.

    Directory of Open Access Journals (Sweden)

    Beatriz LEGEREN LAGO

    2015-07-01

    ñó y desarrolló un proyecto de entretenimiento interactivo para el alumnado que consistió en dos videojuegos multilingües (una aventura gráfica y una simulación. Finalmente evaluamos el nivel de satisfacción de alumnos y profesores con respecto a los cursos de capacitación y las nuevas herramientas diseñadas. En el presente curso 2014-15 estamos evaluando los conocimientos adquiridos por los alumnos de los centros participantes después de mejorar el nivel de formación del profesorado y del uso y disfrute de los videojuegos desarrollados. En el trabajo que presentamos ahora nos centramos en la fase de creación y validación de dichos videojuegos y en la metodología de aprendizaje basada en la experiencia en el diseño de los productos de entretenimiento interactivos.Las conclusiones a las que hemos llegado tras este trabajo han sido que el uso de videojuego para el aprendizaje de materias tan teóricas como puede ser el conocimiento de la Unión Europea pueden ser herramientas muy motivantes y efectivas para su uso en el aula. 

  11. ACCOUNTABILITY: A RAZÃO DE SER DA CONTABILIDADE

    Directory of Open Access Journals (Sweden)

    MIBA MASAYUKI NAKAGAWA

    2007-01-01

    Full Text Available Este trabajo tuvo como objetivo comprender si la accountability es, o no, la razón de ser de la Contabilidad. Si la respuesta es positiva y correctamente comprendida por los maestros, investigadores y profesionales de la Contabilidad, podremos alimentar la esperanza de que nuestro estatus social, político y económica alcanzará brevemente el nivel deseado por todos nosotros, en la misma medida en la que el concepto de accountability sea aplicado en nuestro País, con due diligence. Las pesquisas que vienen siendo realizadas hace más de 15 (quince años en la Fundación Instituto de Investigaciones Contables, Actuarias y Financieras (Fipecafi vinculada a la FEA/USP, revelan que, en el mundo de los negocios públicos y privados, existen básicamente dos formas de accountability, de ellas es de naturaleza exógena y otra endógena. Las dos formas de accountability aportan para la comprensión del concepto de plena accountability a que se refiere el modelo de gobierno empresarial de la International Federation of Accountants (Ifac. La pesquisa de campo que, en el inicio de los años 90, fue objeto de una consulta de la directoria para América del Sur y Caribe del Banco Mundial a la Fipecafi, con el objetivo de medirse el nivel de accountability en Brasil, tanto en el sector público como privado, es algo que aún permanece en abierto, como desafío para los porvenires encuestadores de esa tema.

  12. ACCOUNTABILITY: A RAZÃO DE SER DA CONTABILIDADE

    Directory of Open Access Journals (Sweden)

    MASAYUKI NAKAGAWA, MIBA

    2007-12-01

    Full Text Available Este trabalho teve como objetivo compreender se a accountability é, ou não, a razão de ser da Contabilidade. Se a resposta for positiva e corretamente compreendida pelos professores, pesquisadores e profissionais da Contabilidade, poderemos alimentar a esperança de que o nosso status social, político e econômica atingirá brevemente o nível desejado por todos nós, na mesma medida em que o conceito de accountability for aplicado em nosso País, com due diligence. As pesquisas que vêm sendo realizadas há mais de 15 (quinze anos na Fundação Instituto de Pesquisas Contábeis, Atuariais e Financeiras (Fipecafi vinculada à FEA/USP, revelam que, no mundo dos negócios públicos e privados, existem basicamente duas formas de accountability, uma delas é de natureza exógena e outra endógena. As duas formas de accountability contribuem para a compreensão do conceito de plena accountability a que se refere o modelo de governança empresarial da International Federation of Accountants (Ifac. A pesquisa de campo que, no início dos anos 90, foi objeto de uma consulta da diretoria para a América do Sul e Caribe do Banco Mundial à Fipecafi, com o objetivo de se mensurar o nível de accountability no Brasil, tanto no setor público como privado, é algo que ainda permanece em aberto, como desafio para os futuros pesquisadores desse tema.

  13. Industrial Applications of the Surface-Enhanced Raman Spectroscopy Application industrielle du SERS

    Directory of Open Access Journals (Sweden)

    Nabiev I.

    2006-11-01

    Full Text Available Surface-enhanced Raman scattering (SERS spectroscopy is now a well-established phenomenon, which has been thoroughly characterized in a variety of interfacial and colloidal environments. Although some quantitative aspects of the underlying enhancement mechanisms apparently remain unresolved, attention is now shifting towards application of SERS to explore phenomena of chemical, physical, biological and industrial significance. The goal of this review is to appreciate the industrial value of innovative SERS technique on the basis of our experience in development of new SERS-active substrates and in their biomedical and biotechnological applications. Examples of diverse SERS analytical applications as well as some very recent facilities, as SERS microprobe analysis, SERS fiber optics probes, FT-SERS spectroscopy, SERS detection for high-performance liquid chromatography, etc. , are also discussed. Le SERS (Surface Enhanced Raman Spectroscopy est un phénomène aujourd'hui bien connu qui a été étudié dans toute une gamme de milieux interfaciaux et colloïdaux. Si certains aspects quantitatifs des mécanismes d'exaltation restent apparemment non résolus, l'attention se porte à présent vers l'application de la spectroscopie SERS à l'exploration de phénomènes présentant un intérêt chimique, physique, biologique et industriel. L'objectif de cet article est d'estimer la valeur industrielle des nouvelles techniques de spectroscopie SERS à partir de notre expérience dans le développement de nouveaux substrats actifs en SERS et leurs applications biomédicales et biotechnologiques. Les auteurs discutent également des exemples de diverses applications analytiques de la spectroscopie SERS ainsi que de quelques procédés très récents : analyse par microsonde SERS, sondes SERS à fibres optiques, spectroscopie FT-SERS, détection SERS pour la chromatographie haute performance en phase liquide, etc.

  14. Loss of p53 Ser18 and Atm results in embryonic lethality without cooperation in tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Heather L Armata

    Full Text Available Phosphorylation at murine Serine 18 (human Serine 15 is a critical regulatory process for the tumor suppressor function of p53. p53Ser18 residue is a substrate for ataxia-telangiectasia mutated (ATM and ATM-related (ATR protein kinases. Studies of mice with a germ-line mutation that replaces Ser18 with Ala (p53(S18A mice have demonstrated that loss of phosphorylation of p53Ser18 leads to the development of tumors, including lymphomas, fibrosarcomas, leukemia and leiomyosarcomas. The predominant lymphoma is B-cell lymphoma, which is in contrast to the lymphomas observed in Atm(-/- animals. This observation and the fact that multiple kinases phosphorylate p53Ser18 suggest Atm-independent tumor suppressive functions of p53Ser18. Therefore, in order to examine p53Ser18 function in relationship to ATM, we analyzed the lifespan and tumorigenesis of mice with combined mutations in p53Ser18 and Atm. Surprisingly, we observed no cooperation in survival and tumorigenesis in compound p53(S18A and Atm(-/- animals. However, we observed embryonic lethality in the compound mutant animals. In addition, the homozygous p53Ser18 mutant allele impacted the weight of Atm(-/- animals. These studies examine the genetic interaction of p53Ser18 and Atm in vivo. Furthermore, these studies demonstrate a role of p53Ser18 in regulating embryonic survival and motor coordination.

  15. Sonochemically synthesized Ag nanoparticles as a SERS active substrate and effect of surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Dar, Nitzan, E-mail: n58987012@mail.ncku.edu.tw [Department of Material Science and Engineering, National Cheng Kung University, Tainan 70101 Taiwan (China); Chen, Kuang-Yu [Department of Material Science and Engineering, National Cheng Kung University, Tainan 70101 Taiwan (China); Nien, Yung-Tang, E-mail: ytnien@nfu.edu.tw [Department of Materials Science and Engineering, National Formosa University, Huwei, Yunlin 63201, Taiwan (China); Perkas, Nina [Institute of nanotechnology and advanced materials, Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002 (Israel); Gedanken, Aharon, E-mail: Aharon.Gedanken@biu.ac.il [Institute of nanotechnology and advanced materials, Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002 (Israel); Chen, In-Gann, E-mail: ingann@mail.ncku.edu.tw [Department of Material Science and Engineering, National Cheng Kung University, Tainan 70101 Taiwan (China)

    2015-03-15

    Highlights: • Solid state Ag SERS active substrates were sonochemically synthesized. • High intensity SERS spectra of both crystal violet and rhodamine 6G were observed. • We discovered that PVP aided synthesized substrates showed higher SERS intensity. - Abstract: Surface enhanced Raman scattering (SERS) enables the detection of substances at low concentrations using silver or gold nanostructure. The SERS technique has many applications, such as environmental detection and biosensing. Sonochemistry is an excellent and cheap deposition technique for coating substrates in a form of nanostructure at ambient temperature. It can also be utilized to prepare large SERS substrates. Here, we used the advantages of sonochemistry to deposit solid SERS substrates immobilized on GaN nanostructure. Morphology was studied by scanning electron microscopy. The elemental composition and the spatial distribution were examined by energy dispersive X-ray spectroscopy. The crystal structure and atomic presence was confirmed by X-ray diffraction. SERS substrates were examined with the analytes crystal violet (10{sup −5} M) and rhodamine 6G (10{sup −6} M), they showed prominent characteristic peaks. We discovered that the SERS intensity of poly-vinyl-pyrrolidinone aided sonochemical deposition of Ag nanoparticles was increased. The reason for the effect is morphological changes of the Ag nanoparticles. Smaller nanoparticles were fabricated, which increase their SERS intensity.

  16. Obesidade infantil: como podemos ser eficazes? Childhood obesity: towards effectiveness

    Directory of Open Access Journals (Sweden)

    Elza D. de Mello

    2004-06-01

    Full Text Available OBJETIVO: Revisar a abordagem terapêutica da obesidade infantil, bem como aspectos de seu diagnóstico e prevenção. FONTES DOS DADOS: Foi realizada busca de artigos científicos através das bases de dados MEDLINE, Ovid, Highwire e Scielo. As palavras-chave utilizadas foram: "childhood obesity" e também combinações junto a "treatment", "prevention" e "consequence". Dentre os artigos provenientes da busca incluíam-se artigos de revisão, estudos observacionais, ensaios clínicos e posições de consenso. Percebida a relevância, também se buscou diretamente referências indicadas. O período de coleta de dados foi de 1998 a 2003. SÍNTESE DOS DADOS: Foram encontrados vários trabalhos de prevalência no Brasil. No entanto, poucos trazem resultados de programas educativos aplicáveis em nosso meio. CONCLUSÕES: Deve-se prevenir a obesidade infantil com medidas adequadas de prescrição de dieta na infância desde o nascimento, além de se estudar mais sobre programas de educação que possam ser aplicados no nível primário de saúde e nas escolas.OBJECTIVE: To review therapeutic approaches to childhood obesity and also its diagnosis and prevention. SOURCES OF DATA: Searches were performed of scientific papers held on the MEDLINE, Ovid, Highwire and Scielo databases. Keywords utilized were: "childhood obesity" and a variety of combinations of this term with "treatment", "prevention" and "consequence". The search returned papers including review articles, observational studies, clinical trials and consensus statements. Bibliographical references in these articles were also investigated if it was perceived that they were relevant. Data was collected from 1998 to 2003. SUMMARY OF THE FINDINGS: While a number of different Brazilian prevalence studies were found, few gave details of the results of educational programs in our country. CONCLUSIONS: Childhood obesity must be prevented through prescriptive diets from birth throughout childhood

  17. PGC-1alpha Gly482Ser polymorphism associates with hypertension among Danish whites

    DEFF Research Database (Denmark)

    Andersen, Gitte; Wegner, Lise; Jensen, Dorit Packert

    2005-01-01

    PGC-1alpha is a coactivator of numerous transcription factors and is expressed in tissues with high energy demands and abundant in mitochondria. It is induced in the myocardium on fasting and physical exercise, and cardiac-specific overexpression stimulates mitochondrial biogenesis in mice....... The common Gly482Ser polymorphism of PGC-1alpha has previously shown association with arterial hypertension among Austrian men. Thus, we aimed at investigating this relationship in the Danish white population. The Gly482Ser polymorphism was genotyped in a total of 2562 Danish white subjects using polymerase......, the Ser/Ser genotype group had an estimated odds ratio of 0.70 (95% confidence interval, 0.56 to 0.86) for hypertension compared with Gly/X carriers (P=0.001). In conclusion, the Ser allele of PGC-1alpha Gly482Ser confers a significantly reduced risk of hypertension in whites. Further studies are needed...

  18. Jóvenes investigadores: La formación del ser investigador: obstáculos y desafíos Young researchers: The Formation of to be Researcher: Obstacles and Challenges

    Directory of Open Access Journals (Sweden)

    María Nubia Romero B.

    2007-09-01

    Full Text Available Reflexión sobre la necesidad de apuntalar esfuerzos locales y globales en la formación y fortalecimiento de espíritus científicos en Enfermería. Explora tres elementos centrales: uno, alrededor del papel de la educación superior en la formación de investigadoras; dos, acerca del significado de ser investigadora, y tres, el papel que han de desempeñar las instituciones formadoras y empleadoras en este ejercicio pedagógico y de vida al formar y consolidar el ser investigador. En estos elementos se encuentra un reto de transformación para el presente y futuro de la enfermería, y por ello la reflexión se centra en el análisis de tres dimensiones complementarias: el deseo del sujeto, la voluntad política de la institución y el campo del saber en la investigación, presentando sus obstáculos y desafíos y entendiendo que lo que se expresa es un deseo propositivo para abonar el terreno donde han de germinar las semillas que darán frutos científicos, quizá con esperanzas en el pregrado, pero con certezas en niveles de formación avanzada, como maestrías y doctorados.A reflection about the necessity to prop up local and global efforts in formation and strengthening of scientific spirits inside nursing. It explores three central elements: one, around the upper education’s role in the researches formation; two, about the meaning of to be researcher, and three, the role that training and employment institutions should play in this exercise of pedagogy and of life to form and fortify to be researcher. Into these elements it is found a challenge of transformation for present and future in nursing, and for that, the reflection’s core is the analysis of three complementary dimensions: the individual wish, the political will of the institution, and the knowledge in the research, showing its handicaps and challenges, and understanding the expressed things are wishes that are proposed to fertilize the ground where the seeds that are going

  19. Novel bottom-up SERS substrates for quantitative and parallelized analytics.

    Science.gov (United States)

    Strelau, Katharina K; Schüler, Thomas; Möller, Robert; Fritzsche, Wolfgang; Popp, Jürgen

    2010-02-01

    Surface-enhanced Raman spectroscopy (SERS) is an emerging technology in the field of analytics. Due to the high sensitivity in connection with specific Raman molecular fingerprint information SERS can be used in a variety of analytical, bioanalytical, and biosensing applications. However, for the SERS effect substrates with metal nanostructures are needed. The broad application of this technology is greatly hampered by the lack of reliable and reproducible substrates. Usually the activity of a given substrate has to be determined by time-consuming experiments such as calibration or ultramicroscopic studies. To use SERS as a standard analytical tool, cheap and reproducible substrates are required, preferably with a characterization technique that does not interfere with the subsequent measurements. Herein we introduce an innovative approach to produce low-cost and large-scale reproducible substrates for SERS applications, which allows easy and economical production of micropatterned SERS active surfaces on a large scale. This approach is based on an enzyme-induced growth of silver nanostructures. The special structural feature of the enzymatically deposited silver nanoparticles prevents the breakdown of SERS activity even at high particle densities (particle density >60%) that lead to a conductive layer. In contrast to other approaches, this substrate exhibits a relationship between electrical conductivity and the resulting SERS activity of a given spot. This enables the prediction of the SERS activity of the nanostructure ensemble and therewith the controllable and reproducible production of SERS substrates of enzymatic silver nanoparticles on a large scale, utilizing a simple measurement of the electrical conductivity. Furthermore, through a correlation between the conductivity and the SERS activity of the substrates it is possible to quantify SERS measurements with these substrates.

  20. TLC-SERS Plates with a Built-In SERS Layer Consisting of Cap-Shaped Noble Metal Nanoparticles Intended for Environmental Monitoring and Food Safety Assurance

    Directory of Open Access Journals (Sweden)

    H. Takei

    2015-01-01

    Full Text Available We report on a thin layer chromatograph (TLC with a built-in surface enhanced Raman scattering (SERS layer for in-situ identification of chemical species separated by TLC. Our goal is to monitor mixture samples or diluted target molecules suspended in a host material, as happens often in environmental monitoring or detection of food additives. We demonstrate that the TLC-SERS can separate mixture samples and provide in-situ SERS spectra. One sample investigated was a mixture consisting of equal portions of Raman-active chemical species, rhodamine 6 G (R6G, crystal violet (CV, and 1,2-di(4-pyridylethylene (BPE. The three components could be separated and their SERS spectra were obtained from different locations. Another sample was skim milk with a trace amount of melamine. Without development, no characteristic peaks were observed, but after development, a peak was observed at 694 cm−1. Unlike previous TLC-SERS whereby noble metal nanoparticles are added after development of a sample, having a built-in SERS layer greatly facilitates analysis as well as maintaining high uniformity of noble metal nanoparticles.

  1. Surface-enhanced Raman scattering (SERS) for detection of phenylketonuria for newborn screening

    Science.gov (United States)

    Javanmard, M.; Davis, R. W.

    2014-02-01

    Diagnosis of Phenylketonuria (PKU) in newborns is important because it can potentially help prevent mental retardation since it is treatable by dietary means. PKU results in phenylketonurics having phenylalanine levels as high as 2 mM whereas the normal upper limit in healthy newborns is 120 uM. To this end, we are developing a microfluidic platform integrated with a SERS substrate for detection of high levels of phenylalanine. We have successfully demonstrated SERS detection of phenylalanine using various SERS substrates fabricated using nanosphere lithography, which exhibit high levels of field enhancement. We show detection of SERS at clinically relevant levels.

  2. Re-thinking surface enhance Raman spectroscopy (SERS) sensors with a systems perspective

    Science.gov (United States)

    White, Ian M.

    2017-02-01

    While surface enhanced Raman spectroscopy (SERS) may not compete with the standard central lab approaches for chemical and biological sensing, SERS may have the potential to provide unique capabilities for analytics away from the central lab. Raman spectrometers have evolved from benchtop systems to high-performing handheld instruments that are compatible with analysis of samples in the field. However, for SERS to truly succeed as a "point-of-sample" analytical technique, the SERS sensor must fit the needs of analysis in the field, including little or no sample preparation, minimal peripheral equipment, and ease of use. Traditional plasmonically-active rigid devices do not meet these requirements. Even microfluidic SERS devices generally are not compatible with point-of-sample analysis, as the "world-to-chip" interface presents challenges, and peripheral equipment is generally required. In this review we will discuss the advances in plasmonic substrates fabricated on porous membranes, leading to SERS sensors that can collect samples via swabbing or dipping, clean up samples through separation, concentrate analytes by lateral flow focusing, and avoid the need for peripheral equipment. In particular, we will focus on inkjet-fabricated devices, which may present the best opportunity for scale-up via roll-to-roll manufacturing. We will also discuss the directions that flexible SERS sensors are moving the field, such as simple fabrication techniques, new support materials, SERS swabs, and SERS-active tapes and films.

  3. Graphene-Plasmonic Hybrid Platform for Label-Free SERS Biomedical Detection

    Science.gov (United States)

    Wang, Pu

    Surface Enhanced Raman Scattering (SERS) has attracted explosive interest for the wealth of vibrational information it provides with minimal invasive effects to target analyte. Nanotechnology, especially in the form of noble metal nanoparticles exhibit unique electromagnetic and chemical characteristics that are explored to realize ultra-sensitive SERS detection in chemical and biological analysis. Graphene, atom-thick carbon monolayer, exhibits superior chemical stability and bio-compatibility. A combination of SERS-active metal nanostructures and graphene will create various synergies in SERS. The main objective of this research was to exploit the applications of the graphene-Au tip hybrid platform in SERS. The hybrid platform consists of a periodic Au nano-pyramid substrate to provide reproducible plasmonic enhancement, and the superimposed monolayer graphene sheet, serving as "built-in" Raman marker. Extensive theoretical and experimental studies were conducted to determine the potentials of the hybrid platform as SERS substrate. Results from both Finite-Domain Time-Domain (FDTD) numerical simulation and Raman scattering of graphene suggested that the hybrid platform boosted a high density of hotspots yielding 1000 times SERS enhancement of graphene bands. Ultra-high sensitivity of the hybrid platform was demonstrated by bio-molecules including dye, protein and neurotransmitters. Dopamine and serotonin can be detected and distinguished at 10-9 M concentration in the presence of human body fluid. Single molecule detection was obtained using a bi-analyte technique. Graphene supported a vibration mode dependent SERS chemical enhancement of ˜10 to the analyte. Quantitative evaluation of hotspots was presented using spatially resolved Raman mapping of graphene SERS enhancement. Graphene plays a crucial role in quantifying SERS hotspots and paves the path for defining SERS EF that could be universally applied to various SERS systems. A reproducible and statistically

  4. Body’s perceptions of elderly women in a physical activity program Cambios en la percepción del cuerpo de mujeres de edad avanzada, a través de un programa de actividad física

    Directory of Open Access Journals (Sweden)

    P. Silva

    2011-06-01

    Full Text Available

    The aim of the study is to know elderly women’s body perceptions and the importance of a multicomponent physical activity program. Semi-structured interviews and focus groups were conducted in 19 elderly women. Data were subjected to an interpretative analysis after the treatment of the information (QSRNVivo7. Before the PA program, data suggested social representations of the female body: weakened body; functional limitations; sickness. These women seek PA program because they expect body improvements: functional independence; health; physical appearance. After PA program they perceived some changes related to their mobility; better capacity to cope with chronic disease and counter with advancing age; and also physical repositioning of identities. In this way, physical activity program can be considered as a valid instrument for body empowerment, an “independent” and “healthy” body, i.e., weakened body recovers a certain social significance and repositions itself in the society.
    Key Words: women, physical activity, body

    El objetivo de este estudio es conocer la percepción del cuerpo de las mujeres en edad avanzada antes y después de un programa multicomponente de actividad física. Los datos de las entrevistas, semiestructuradas y de grupo, a 19 ancianas se sometieron a un análisis interpretativo tras el tratamiento de la información (QSRNVivo7. Antes del programa de actividad física, los datos reflejan representaciones sociales de un cuerpo envejecido y frágil (con dolores y limitaciones funcionales. Estas mujeres buscan la actividad física por razones relacionadas con la independencia funcional y con la salud, y también con la apariencia física. Tras el programa, las mujeres percibieron un cuerpo más ágil, capaz de controlar el dolor y detener el avance de la edad. Las mujeres identifican la actividad física como un instrumento importante para mantenerse

  5. El deber ser de la auditoría

    Directory of Open Access Journals (Sweden)

    Omar de Jesús Montilla Galvis

    2006-01-01

    Full Text Available No falta mucho tiempo para asistir a la integración de las sociedades de la Tierra, a llegar a lo que algunos denominan “aldea global”. No podemos detener los cambios, u oponernos a ellos con la idea de que si les somos indiferentes y no les damos importancia no suceden. Las naciones se vienen transformando multidimensionalmente, no es sólo la tecnología, ni los nichos de mercado, nilas formas de producción, ni la competencia en las economías liberadas, es uncambio en la manera cognoscitiva de pensar y actuar en el mundo de hoy. La auditoría es una práctica de trascendental importancia social y económica, permite entablar relaciones de diversa índole entre los agentes económicos, debido a la confianza que se deposita en el trabajo de los contadores públicos cuando ellos extienden su garantía personal o fe pública, respecto del trabajo de investigación denominado auditoría. Es respecto al conocimiento sobre la auditoría que el presente artículo propone hacerle frente a la necesidad de cambio, las adaptaciones y transformaciones con las que sobreviven las especies, la auditoría se ve en grave riesgo de ser absorbida por otras profesiones, motivo por el cual es necesario comenzar un proceso de adaptación para que sobreviva como una práctica propia de los contadores públicos. La adaptación propuesta tiene como finla evolución de la auditoría, “articulando” toda la información derivada del desarrollo del objeto social de las organizaciones para realizar gestión del conocimiento en las mismas, de este modo convertir dicho conocimiento en la ventaja competitiva más importante de la organización. No es posible esperar que la auditoría continúe con las ideas de su génesis antes de la era cristiana, o con los cambios sufridos a causa de la gran depresión, la responsabilidad de la auditoría ahora tiene que ver con el mejoramiento dela sociedad como efecto del cambio de las organizaciones. Es hora de romper el statu quo

  6. Evaluación de la retinopatía diabética proliferativa después del tratamiento con láser Evaluation of proliferative diabetic retinopathy after laser treatment

    Directory of Open Access Journals (Sweden)

    Juana Elvira Maciques Rodríguez

    2007-12-01

    Full Text Available La fotocoagulación láser (panfotocoagulación es indicación absoluta en la retinopatía diabética proliferativa (RDP sin y con características de alto riesgo de pérdida visual severa. Con el objetivo de evaluar este tratamiento en la RDP, se realizó este estudio desde enero de 2004 a diciembre de 2005 en el Centro de Atención al Diabético del Instituto de Endocrinología. Se estudiaron 120 pacientes con RDP, que se fotocoagularon. Las variables estudiadas fueron: edad, sexo, tiempo de evolución de la diabetes y presencia de hipertensión arterial y/o neuropatía. Se realizó examen oftalmológico y se comparó la agudeza visual y el estadio de la retinopatía antes y después del tratamiento. Para el análisis estadístico se utilizó la prueba de chi cuadrado. La forma avanzada de RDP se encontró en pacientes con más de 20 años de evolución de la enfermedad. Después del tratamiento en las mujeres predominó la RDP sin características de alto riesgo (CAR (38,1 % y en los hombres la RDP con CAR (38,9 %; 11 pacientes pasaron a la forma de retinopatía diabética (RD no proliferativa. La hipertensión arterial y la nefropatía diabética predominaron en la RDP con CAR y avanzada. Se concluye que la forma más grave de RD se asoció a mayor tiempo de evolución. La hipertensión arterial y la nefropatía son factores de riesgo asociados a las formas más severas de RD. La fotocoagulación no mejoró la visión de forma significativa, pero sí detiene la progresión de la retinopatía, e incluso, es capaz de modificar la severidad pasando a formas no proliferativas.Laser photocoagulation (panphotocoagulation is an absolute indication in the proliferative diabetic retinopathy (PDR without or with characteristics of high risk for severe visual loss. This study was undertaken at the Diabetic Care Center of the Institute of Endocrinology from January 2004 to December 2005 in order to evaluate this treatment in PDR. 120 patients with PDR

  7. Influencia de las especies del dosel en la disponibilidad de recursos y regeneración avanzada en un bosque templado lluvioso del sur de Chile Influence of overstorey species identity on resource availability and variation in composition of advanced regeneration in a temperate rainforest in southern Chile

    Directory of Open Access Journals (Sweden)

    ALFREDO SALDAÑA

    2003-12-01

    Full Text Available La heterogeneidad de hábitat en el sotobosque es un factor que promueve el mantenimiento de la diversidad de especies de la comunidad forestal. En este estudio se evaluó la influencia de cuatro especies dominantes de un bosque templado del sur de Chile, Laureliopsis philippiana, Aextoxicon punctatum, Eucryphia cordifolia y Nothofagus dombeyi, sobre la disponibilidad de recursos y su relación con la composición de la regeneración avanzada. Se estimó el porcentaje de luz difusa, la disponibilidad de nitrógeno, fósforo y calcio, el contenido de nitrógeno, fósforo y calcio de la hojarasca, y se determinó la composición de la regeneración avanzada bajo los doseles de cada una de las cuatro especies. Además, se realizó una ordenación para evaluar la variación de la composición de la regeneración avanzada. Se encontraron diferencias significativas en la transmisión de luz bajo cada especie, así como en el contenido nutricional de la hojarasca y disponibilidad de los nutrientes N-NO3 y P. Los tres nutrientes evaluados presentaron escasa disponibilidad en el suelo, debido a baja mineralización y alta inmovilización. De acuerdo a la ordenación, la composición de la regeneración avanzada bajo N. dombeyi y L. philippiana, fue distinguible de la composición de la regeneración bajo E. cordifolia y A. punctatum. La luz fue el recurso que explicó la mayor parte de la variación en la composición de la regeneración avanzada en el sotobosque. En cambio, la variación en la disponibilidad de nutrientes no tuvo relación con la especie en el dosel. Postulamos que las especies que regeneran bajo este dosel difieren más en sus requerimientos lumínicos que nutricionales, siendo la luz el recurso más limitante en el sotobosqueUnderstory habitat heterogeneity is a factor promoting maintenance of species diversity in forest communities. The influence of over storey species identity on resource availability and variation in composition of

  8. Silver nanoflowers for single-particle SERS with 10 pM sensitivity.

    Science.gov (United States)

    Roy, Shrawan; Muhammed Ajmal, C; Baik, Seunghyun; Kim, Jeongyong

    2017-11-17

    Surface-enhanced Raman scattering (SERS) has received considerable attention as a noninvasive optical sensing technique with ultrahigh sensitivity. While numerous types of metallic particles have been actively investigated as SERS substrates, the development of new SERS agents with high sensitivity and their reliable characterization are still required. Here we report the preparation and characterization of flower-shaped silver (Ag) nanoparticles that exhibit high-sensitivity single-particle SERS performance. Ag nanoflowers (NFs) with bud sizes in the range 220-620 nm were synthesized by the wet synthesis method. The densely packed nanoscale petals with thicknesses in the range 9-22 nm exhibit a large number of hot spots that significantly enhance their plasmonic activity. A single Ag NF particle (530-620 nm) can detect as little as 10 -11 M 4-mercaptobenzoic acid, and thus provides a sensitivity three orders of SERS magnitude greater than that of a spherical Ag nanoparticle. The analytical enhancement factors for single Ag NF particles were found to be as high as 8.0 × 10 9 , providing unprecedented high SERS detectivity at the single particle level. Here we present an unambiguous and systematic assessment of the SERS performances of the Ag NFs and demonstrate that they provide highly sensitive sensing platforms by single SERS particle.

  9. SER-Commissie neemt roer Arboraad over: afscheid met gemengde gevoelens

    NARCIS (Netherlands)

    Blijswijk, M. van

    1993-01-01

    De Arboraad heeft haar laatste vergadering achter de rug. De Raad wordt geïntegreerd in de SER door middel van een nieuwe SER-commissie Arbeidsomstandigheden. Hoewel de oud-voorzitter van de Arboraad pleitte voor een voorlopig nog zelfstandig functionerende Raad, wil minister De Vries door middel

  10. Reduced graphene oxide-supported gold nanostars for improved SERS sensing and drug delivery.

    Science.gov (United States)

    Wang, Yusong; Polavarapu, Lakshminarayana; Liz-Marzán, Luis M

    2014-12-24

    Development of novel surface-enhanced Raman scattering (SERS) substrates and how they interface target analytes plays a pivotal role in determining the spectrum profile and SERS enhancement magnitude, as well as their applications. We present here the seed-mediated growth of reduced graphene oxide-gold nanostar (rGO-NS) nanocomposites and employ them as active SERS materials for anticancer drug (doxorubicin, DOX) loading and release. By this synthetic approach, both the morphology of rGO-NS nanohybrids and the corresponding optical properties can be precisely controlled, with no need of surfactant or polymer stabilizers. The developed rGO-NS nanohybrids show tunable optical properties by simply changing growth reaction parameters, improved stability as compared to bare Au nanostars, and sensitive SERS response toward aromatic organic molecules. Furthermore, SERS applications of rGO-NS to probe DOX loading and pH-dependent release are successfully demonstrated, showing promising potential for drug delivery and chemotherapy.

  11. Gold dimer nanoantenna with slanted gap for tunable LSPR and improved SERS

    KAUST Repository

    Kessentini, Sameh

    2014-02-13

    We focus on improving the surface-enhanced Raman scattering (SERS) of dimer nanoantenna by tailoring the shape of the coupled nanoantennas extremities from rounded to straight or slanted ones. A numerical model based on the discrete dipole approximation method-taking into account periodicity, adhesion layer, and roughness-is first validated by comparison with localized surface plasmon resonance (LSPR) and SERS experiments on round-edged dimer nanoantennas and then used to investigate the effect of the straight or slanted gap in the dimer antenna. Simulations show that both LSPR and SERS can be tuned by changing the gap slanting angle. The SERS enhancement factor can also be improved by 2 orders of magnitude compared to the one reached using a rounded gap. Therefore, the slanting angle can be used as a new control parameter in the design of SERS substrates to guarantee stronger field confinement and higher sensitivity, especially as its feasibility is demonstrated. © 2014 American Chemical Society.

  12. Technology transfer and application of SERS continuous monitor for trace organic compounds

    International Nuclear Information System (INIS)

    Swindle, D.W. Jr.; Vo-Dinh, T.; Yalcintas, M.G.

    1992-01-01

    An in situ-enhanced Raman Scattering (SERS) continuous monitoring system was developed for exciting and collecting SERS signals generated on silver-coated microparticles deposited on a continuously rotating filter-paper support. SERS measurements were successfully conducted for several organic compounds. An in situ SERS fiber-optic system was also developed for exciting and collecting SERS signals generated from a sensing tip having silver-coated microparticles deposited on a glass-plate support. These devices will be very useful in remote identification of unknown chemicals from hazardous waste sites. This patented technology has been licensed from Oak Ridge National Laboratory to an analytical instrumentation firm which is in the process of completing development and marketing these detectors. Advantages to using this technology range from increased safety and sensitivity for detecting hazardous compounds to better statistics and reliable results. During this presentation, efforts of the Environmental Restoration Program to evaluate and support development of this technology will be described

  13. Gold Superparticles Functionalized with Azobenzene Derivatives: SERS Nanotags with Strong Signals.

    Science.gov (United States)

    Ma, Ying; Promthaveepong, Kittithat; Li, Nan

    2017-03-29

    The surface-enhanced Raman spectroscopy (SERS) nanotag was proposed as a substitute for fluorescent dye for imaging and biosensors several decades ago. However, its weak signal and poor reproducibility has hindered its application. Here, we report a new strategy to form Au superparticles (AuSPs) with high SERS enhancement via one-pot formation and self-assembly of Au nanoparticles (NPs). An azobenzene-carrying Raman reporter was synthesized to exhibit a large Raman cross-section and multiple bands. The self-assembly of the Raman reporter on AuSPs generated SERS nanotags with intense signals. A Raman reporter carrying boronic acid and azobenzene groups displayed six distinctive bands. Its corresponding SERS nanotag demonstrated a high sensing ability toward glycoprotein through aggregation-induced SERS enhancement or as a substitute for labeled antibodies in an immunoassay of the glycoprotein.

  14. [Monolithic column-gold composite substrate preparation and application to SERS detection of pigment].

    Science.gov (United States)

    Xie, Yun-Fei; Li, Yan; Yu, Hui; Qian, He; Yao, Wei-Rong

    2014-03-01

    In the present study, we developed a novel SERS substrate with the porous monolith material combined with classic gold nanoparticles, and erythrosine as the research object, by adjusting the different experimental conditions for optimal SERS enhancements, including system pH and mixing time, and ultimately selected the optimum pH value 5.06 and mixing time 25 min. Compared with the traditional gold plastic substrate enhancement effect, the experimental conditions were applied to the monolith substrate SERS detection of dye erythrosine, different concentrations of samples were used for erythrosine SERS detection, and the detection limit reached 0.1 g x mL(-1). The method uses the payload of gold nanoparticles in mesoporous materials to effectively enhance the SERS signal. And this method has the advantages of simpleness and good stability, which provides a favorable theoretical basis for the rapid prohibited colorings screening.

  15. A Widely Applicable Silver Sol for TLC Detection with Rich and Stable SERS Features

    Science.gov (United States)

    Zhu, Qingxia; Li, Hao; Lu, Feng; Chai, Yifeng; Yuan, Yongfang

    2016-04-01

    Thin-layer chromatography (TLC) coupled with surface-enhanced Raman spectroscopy (SERS) has gained tremendous popularity in the study of various complex systems. However, the detection of hydrophobic analytes is difficult, and the specificity still needs to be improved. In this study, a SERS-active non-aqueous silver sol which could activate the analytes to produce rich and stable spectral features was rapidly synthesized. Then, the optimized silver nanoparticles (AgNPs)-DMF sol was employed for TLC-SERS detection of hydrophobic (and also hydrophilic) analytes. SERS performance of this sol was superior to that of traditional Lee-Meisel AgNPs due to its high specificity, acceptable stability, and wide applicability. The non-aqueous AgNPs would be suitable for the TLC-SERS method, which shows great promise for applications in food safety assurance, environmental monitoring, medical diagnoses, and many other fields.

  16. eenagers Want to be Mothers... But... Las adolescentes quieren ser madres... pero... Adolescentes desejam ser mães… mas…

    Directory of Open Access Journals (Sweden)

    DURÁN DE VILLALOBOS MARÍA MERCEDES

    2010-10-01

    entrevistas a profundidad a 30 adolescentes gestantes, Del análisis emergieron siete categorías: “Embarazo inesperado”, “Asumiendo el embarazo”, “Experimentando formas de cuidarse”, “Padeciendo pérdidas por el embarazo”, “Culpándose por el embarazo”, “Resistiéndose al aborto” y “Reedificando redes de apoyo”. Emerge la categoría central y por ende el planteamiento hipotético afirmando que las adolescentes están “Deseando el embarazo pero no tan pronto”. Se parte del concepto ambivalencia como hilo conductor para mostrar cómo evoluciona esta secuencia de acciones/interacciones en respuesta a la experiencia del embarazo y cómo se alinean según las condiciones y cambios que han experimentado en su contexto también ambivalente.

    Se concluye que las adolescentes embarazadas delegan en el hombre la protección frente a un posible embarazo, sin embargo, cuando se enteran de estar embarazadas los excluyen y excusan de cualquier responsabilidad. Asocian cuidado con cambios en sus comportamientos sociales sin ser significativos los cambios físicos. El 21% de las participantes, están pasando por su segundo embarazo, indicador alarmante para el bienestar de estas jóvenes y sus hijos por nacer. La relación padres-adolescente se afianza durante el embarazo, aunque sus madres cuando tuvieron conocimiento de que sus hijas ya habían iniciado su actividad sexual, lo ignoraron. Se hace un llamado urgente a innovar estrategias de cuidado individualizado y contextualizado.

    Este estudo foi realizado com base teórica e objetivou o seguinte: descrever a experiência de gravidez e gerar uma hipótese sobre esse processo em um grupo de adolescentes; coletar dados através de entrevistas em profundidade realizadas em 30 adolescentes grávidas.

    Sete categorias surgiram da analise: “Gravidez inesperada”; “Assumindo a gravidez”, “Experimentando métodos de prevenção”,

  17. Teenagers Want to be Mothers... But... Las adolescentes quieren ser madres... pero... Adolescentes desejam ser mães… mas…

    Directory of Open Access Journals (Sweden)

    VIRGINIA INÉS SOTO LESMES

    2010-10-01

    álisis emergieron siete categorías: "Embarazo inesperado", "Asumiendo el embarazo", "Experimentando formas de cuidarse", "Padeciendo pérdidas por el embarazo", "Culpándose por el embarazo", "Resistiéndose al aborto" y "Reedificando redes de apoyo". Emerge la categoría central y por ende el planteamiento hipotético afirmando que las adolescentes están "Deseando el embarazo pero no tan pronto". Se parte del concepto ambivalencia como hilo conductor para mostrar cómo evoluciona esta secuencia de acciones/interacciones en respuesta a la experiencia del embarazo y cómo se alinean según las condiciones y cambios que han experimentado en su contexto también ambivalente. Se concluye que las adolescentes embarazadas delegan en el hombre la protección frente a un posible embarazo, sin embargo, cuando se enteran de estar embarazadas los excluyen y excusan de cualquier responsabilidad. Asocian cuidado con cambios en sus comportamientos sociales sin ser significativos los cambios físicos. El 21% de las participantes, están pasando por su segundo embarazo, indicador alarmante para el bienestar de estas jóvenes y sus hijos por nacer. La relación padres-adolescente se afianza durante el embarazo, aunque sus madres cuando tuvieron conocimiento de que sus hijas ya habían iniciado su actividad sexual, lo ignoraron. Se hace un llamado urgente a innovar estrategias de cuidado individualizado y contextualizado.Este estudo foi realizado com base teórica e objetivou o seguinte: descrever a experiência de gravidez e gerar uma hipótese sobre esse processo em um grupo de adolescentes; coletar dados através de entrevistas em profundidade realizadas em 30 adolescentes grávidas. Sete categorias surgiram da analise: "Gravidez inesperada"; "Assumindo a gravidez", "Experimentando métodos de prevenção", "Sofrendo perdas pela gravidez", "Sentindo culpa pela gravidez", "Rejeitando o aborto" e "Reconstruindo redes de apoio". Surge a categoria central e, portanto, a hipótese afirmando que as

  18. Cyanuric acid hydrolase from Azorhizobium caulinodans ORS 571: crystal structure and insights into a new class of Ser-Lys dyad proteins.

    Directory of Open Access Journals (Sweden)

    Seunghee Cho

    Full Text Available Cyanuric acid hydrolase (CAH catalyzes the hydrolytic ring-opening of cyanuric acid (2,4,6-trihydroxy-1,3,5-triazine, an intermediate in s-triazine bacterial degradation and a by-product from disinfection with trichloroisocyanuric acid. In the present study, an X-ray crystal structure of the CAH-barbituric acid inhibitor complex from Azorhizobium caulinodans ORS 571 has been determined at 2.7 Å resolution. The CAH protein fold consists of three structurally homologous domains forming a β-barrel-like structure with external α-helices that result in a three-fold symmetry, a dominant feature of the structure and active site that mirrors the three-fold symmetrical shape of the substrate cyanuric acid. The active site structure of CAH is similar to that of the recently determined AtzD with three pairs of active site Ser-Lys dyads. In order to determine the role of each Ser-Lys dyad in catalysis, a mutational study using a highly sensitive, enzyme-coupled assay was conducted. The 10⁹-fold loss of activity by the S226A mutant was at least ten times lower than that of the S79A and S333A mutants. In addition, bioinformatics analysis revealed the Ser226/Lys156 dyad as the only absolutely conserved dyad in the CAH/barbiturase family. These data suggest that Lys156 activates the Ser226 nucleophile which can then attack the substrate carbonyl. Our combination of structural, mutational, and bioinformatics analyses differentiates this study and provides experimental data for mechanistic insights into this unique protein family.

  19. O livro Г da Metafí­sica de Aristóteles: Ontologia - a Ciência do Ser enquanto Ser

    Directory of Open Access Journals (Sweden)

    Susana Amaral Vieira

    2010-10-01

    Full Text Available o objetivo do presente artigo é o de apontar para o modo em que se realiza a ciência aristotélica do ser enquanto ser. Para isso é necessário esclarecer as noções de "analogia" e "substância", A autora nega a concepçáo realista da substância e pretende situar a questáo dentro do universo semântico e interpretativo da linguagem.

  20. L'oblit: El dret a ser diferent… d'un mateix. Una reconsideració del dret a ser oblidat

    Directory of Open Access Journals (Sweden)

    Norberto Nuno Gomes de Andrade

    2012-03-01

    Full Text Available

    Aquest article proposa una nova conceptualització del dret a ser oblidat, argumenta a favor de la seva construcció teòrica i aplicació concreta emparades en el dret a la identitat. Des d'aquesta perspectiva, l'article pretén llançar una nova llum sobre el dret a ser oblidat per contribuir a una conceptualització i una aplicabilitat  més desenvolupades al mateix temps que n'aclareix l'àmbit d'aplicació.

     

    Basant-se en la distinció entre el dret a la identitat i el dret a la privadesa, l'article presenta els avantatges de relacionar el dret a ser oblidat amb el dret a la identitat. Amb aquesta conceptualització basada en el dret a la identitat, s'afirma que el dret a ser oblidat també s'ha d'aplicar al contingut generat pels usuaris i la informació tractada per a finalitats personals eliminant l'exempció per a activitats domèstiques establerta en la Directiva europea sobre protecció de dades. L'article sosté que el dret a l'oblit, emmarcat com a part del dret a la identitat personal, també ha d'abordar fets públics i informació, oferint una justificació racional i més forta amb la qual aconseguir un equilibri millor i més just amb el dret a la llibertat d'informació amb el qual competeix.

     

    En l'article es comenten els conflictes de drets més rellevants que el dret a ser oblidat haurà d'abordar, és a dir, el conflicte amb la llibertat d'expressió i el conflicte amb la necessitat de preservar la memòria social. 

     

    Com a ramificació del dret a la identitat, el dret a ser oblidat es presenta com el dret a ser diferent, no dels altres sinó d'un mateix, és a dir, del que un era abans. El dret a ser oblidat també subratlla el procés de creació d'identitat no solament constructiu, sinó també desconstructiu. 

  1. Phosphorylation of rat melanopsin at Ser-381 and Ser-398 by light/dark and its importance for intrinsically photosensitive ganglion cells (ipRGCs) cellular Ca2+ signaling

    DEFF Research Database (Denmark)

    Fahrenkrug, Jan; Falktoft, Birgitte; Georg, Birgitte

    2014-01-01

    a number of amino acids with a high probability of being phosphorylated. We generated antibodies against melanopsin phosphorylated at Ser-381 and Ser-398, respectively. The antibody specificity was verified by immunoblotting and immunohistochemical staining of HEK-293 cells expressing rat melanopsin...... mutated in Ser-381 or Ser-398. Using the antibody recognizing phospho-Ser-381 melanopsin, we demonstrated by immunoblotting and immunohistochemical staining in HEK-293 cells expressing rat melanopsin that the receptor is phosphorylated in this position during the dark and dephosphorylated when light......, phosphorylation at Ser-381 and Ser-398 was independent of each other. The changes in phosphorylation were confirmed in vivo by immunohistochemical staining of rat retinas during light and dark. We further demonstrated that mutation of Ser-381 and Ser-398 in melanopsin-expressing HEK-293 cells affected the light...

  2. Phospholipid Encapsulated AuNR@Ag/Au Nanosphere SERS Tags with Environmental Stimulus Responsive Signal Property.

    Science.gov (United States)

    Su, Xueming; Wang, Yunqing; Wang, Wenhai; Sun, Kaoxiang; Chen, Lingxin

    2016-04-27

    Surface-enhanced Raman scattering (SERS) tags draw much attention due to the ultrasensitivity and multiplex labeling capability. Recently, a new kind of SERS tags was rationally designed by encapsulating metal nanoparticles with phospholipid bilayers, showing great potential in theranostics. The lipid bilayer coating confers biocompatibility and versatility to changing surface chemistry of the tag; however, its "soft" feature may influence SERS signal stability, which is rarely investigated. Herein, we prepared phospholipid-coated AuNR@Ag/Au nanosphere SERS tags by using three different kinds of Raman reporters, i.e., thio-containing 4-nitrothiophenol (NT), nitrogen-containing hydrophobic chromophore cyanine 7 monoacid (Cy7), and alkyl chain-chromophore conjugate 1,1'-dioctadecyl-3,3,3',3'-tetramethylindodicarbocyanine (DiD). It was found that signal responses were different upon additional stimulation which the tags may encounter in theranostic applications including the presence of detergent Triton X-100, lipid membrane, and photothermal treatment. Living-cell imaging also showed signal changing distinction. The different SERS signal performances were attributed to the different Raman reporter releasing behaviors from the tags. This work revealed that Raman reporter structure determined signal stability of lipid-coated SERS tags, providing guidance for the design of stimulus responsive tags. Moreover, it also implied the potential of SERS technique for real time drug release study of lipid based nanomedicine.

  3. PKCδ-mediated IRS-1 Ser24 phosphorylation negatively regulates IRS-1 function

    International Nuclear Information System (INIS)

    Greene, Michael W.; Ruhoff, Mary S.; Roth, Richard A.; Kim, Jeong-a; Quon, Michael J.; Krause, Jean A.

    2006-01-01

    The IRS-1 PH and PTB domains are essential for insulin-stimulated IRS-1 Tyr phosphorylation and insulin signaling, while Ser/Thr phosphorylation of IRS-1 disrupts these signaling events. To investigate consensus PKC phosphorylation sites in the PH-PTB domains of human IRS-1, we changed Ser24, Ser58, and Thr191 to Ala (3A) or Glu (3E), to block or mimic phosphorylation, respectively. The 3A mutant abrogated the inhibitory effect of PKCδ on insulin-stimulated IRS-1 Tyr phosphorylation, while reductions in insulin-stimulated IRS-1 Tyr phosphorylation, cellular proliferation, and Akt activation were observed with the 3E mutant. When single Glu mutants were tested, the Ser24 to Glu mutant had the greatest inhibitory effect on insulin-stimulated IRS-1 Tyr phosphorylation. PKCδ-mediated IRS-1 Ser24 phosphorylation was confirmed in cells with PKCδ catalytic domain mutants and by an RNAi method. Mechanistic studies revealed that IRS-1 with Ala and Glu point mutations at Ser24 impaired phosphatidylinositol-4,5-bisphosphate binding. In summary, our data are consistent with the hypothesis that Ser24 is a negative regulatory phosphorylation site in IRS-1

  4. Apoptotic phosphorylation of histone H3 on Ser-10 by protein kinase Cδ.

    Directory of Open Access Journals (Sweden)

    Choon-Ho Park

    Full Text Available Phosphorylation of histone H3 on Ser-10 is regarded as an epigenetic mitotic marker and is tightly correlated with chromosome condensation during both mitosis and meiosis. However, it was also reported that histone H3 Ser-10 phosphorylation occurs when cells are exposed to various death stimuli, suggesting a potential role in the regulation of apoptosis. Here we report that histone H3 Ser-10 phosphorylation is mediated by the pro-apoptotic kinase protein kinase C (PKC δ during apoptosis. We observed that PKCδ robustly phosphorylates histone H3 on Ser-10 both in vitro and in vivo. Ectopic expression of catalytically active PKCδ efficiently induces condensed chromatin structure in the nucleus. We also discovered that activation of PKCδ is required for histone H3 Ser-10 phosphorylation after treatment with DNA damaging agents during apoptosis. Collectively, these findings suggest that PKCδ is the kinase responsible for histone H3 Ser-10 phosphoryation during apoptosis and thus contributes to chromatin condensation together with other apoptosis-related histone modifications. As a result, histone H3 Ser-10 phosphorylation can be designated a new 'apoptotic histone code' mediated by PKCδ.

  5. Phospho-Bcl-xL(Ser62) influences spindle assembly and chromosome segregation during mitosis.

    Science.gov (United States)

    Wang, Jianfang; Beauchemin, Myriam; Bertrand, Richard

    2014-01-01

    Functional analysis of a series of phosphorylation mutants reveals that Bcl-xL(Ser62Ala) influences cell entry into anaphase and mitotic exit in taxol-exposed cells compared with cells expressing wild-type Bcl-xL or a series of other phosphorylation mutants, an effect that appears to be independent of its anti-apoptotic activity. During normal mitosis progression, Bcl-xL(Ser62) is strongly phosphorylated by PLK1 and MAPK14/SAPKp38α at the prometaphase, metaphase, and the anaphase boundaries, while it is de-phosphorylated at telophase and cytokinesis. Phospho-Bcl-xL(Ser62) localizes in centrosomes with γ-tubulin and in the mitotic cytosol with some spindle-assembly checkpoint signaling components, including PLK1, BubR1, and Mad2. In taxol- and nocodazole-exposed cells, phospho-Bcl-xL(Ser62) also binds to Cdc20- Mad2-, BubR1-, and Bub3-bound complexes, while Bcl-xL(Ser62Ala) does not. Silencing Bcl-xL expression and expressing the phosphorylation mutant Bcl-xL(Ser62Ala) lead to an increased number of cells harboring mitotic spindle defects including multipolar spindle, chromosome lagging and bridging, aneuploidy with micro-, bi-, or multi-nucleated cells, and cells that fail to resolve undergo mitosis within 6 h. Together, the data indicate that during mitosis, Bcl-xL(Ser62) phosphorylation impacts on spindle assembly and chromosome segregation, influencing chromosome stability. Observations of mitotic cells harboring aneuploidy with micro-, bi-, or multi-nucleated cells, and cells that fail to resolve undergo mitosis within 6 h were also made with cells expressing the phosphorylation mutant Bcl-xL(Ser49Ala) and dual mutant Bcl-xL(Ser49/62Ala).

  6. Intencionalidad y ausencia en El Ser y La Nada de Jean-Paul Sartre

    OpenAIRE

    Wilfer Alexis Yepes Muñoz

    2017-01-01

    Esta reflexión rehúnde sus raíces en la tensión original de la conciencia con su correlato, esto es, de la conciencia como con- ciencia de algo. Sobre este pilar de la fenomenología husserliana, Sartre construye las estructuras del para-sí que, en la segunda y en la tercera parte de El ser y la nada , enmarcan esa tensión entre la nada humana como para-sí y el en-sí como ser macizo. Esa conciencia, por tanto, pasará a ser una conciencia de nada co...

  7. Synthesis of silver nanocubes as a SERS substrate for the determination of pesticide paraoxon and thiram

    Science.gov (United States)

    Wang, Bin; Zhang, Li; Zhou, Xia

    2014-03-01

    The silver cube-like nanostructure with uniform size and high yield have been synthesized through the rapid sulfide-mediated polyol method. The morphology, structure and optical properties of the as-prepared silver nanocubes were characterized by UV-Visible spectroscopy, field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The Surface-Enhanced Raman Scattering (SERS) performance of the as-prepared Ag nanocubes was characterized by crystal violet (CV) as the probe molecules. Furthermore, the low levels of thiram and pesticide paraoxon can be detected by the SERS technique, which shows that the silver nanocubes as a SERS substrate have excellent sensitivity and reproducibility.

  8. Refletindo sobre a corporeidade do ser criança com paralisia cerebral

    OpenAIRE

    Milbrath, Viviane Marten; Motta, Maria da Graça Corso da; Resta, Darielli Gindri; Freitag, Vera Lucia

    2016-01-01

    Objetivo: instigar o exercício de refletir sobre a corporeidade do ser criança com paralisia cerebral a partir do olhar da fenomenologia existencial. Método: estudo descritivo, do tipo reflexão teórico filosófica à luz da perspectiva heidegeriana. Resultados: os padrões de normalidade vigentes na sociedade supervalorizam as questões morfofuncionais em detrimento do ser criança que vive com necessidades especiais, como um ser que pode adotar uma atitude autêntica e alcançar o auge do desenvolv...

  9. DNA self-assembly on graphene surface studied by SERS mapping

    DEFF Research Database (Denmark)

    Botti, Sabina; Rufoloni, Alessandro; Laurenzi, Susanna

    2016-01-01

    The self-assembly of double-stranded DNA (dsDNA) segments on two variations of graphene surfaces having nano-platelets with different lateral sizes and thicknesses was investigated using surface enhanced Raman spectroscopy (SERS) and electrical impedance spectroscopy (EIS) techniques. Due...... nano-platelets. Results from the EIS analysis supported the SERS findings and confirmed that SERS mapping is a reliable method for a rapid monitoring of the procedures used to interface DNA with graphene surfaces. The present study, linking DNA anchoring morphology to the conductive properties of nano...

  10. Evaluation of Colloids and Activation Agents for Determination of Melamine Using UV-SERS

    OpenAIRE

    Kämmer, Evelyn; Dörfer, Thomas; Csáki, Andrea; Schumacher, Wilm; Da Costa Filho, Paulo Augusto; Tarcea, Nicolae; Fritzsche, Wolfgang; Rösch, Petra; Schmitt, Michael; Popp, Jürgen

    2012-01-01

    UV-SERS measurements offer a great potential for environmental or food (detection of food contaminats) analytics. Here, the UV-SERS enhancement potential of various kinds of metal colloids, such as Pd, Pt, Au, Ag, Au–Ag core–shell, and Ag–Au core–shell with different shapes and sizes, were studied using melamine as a test molecule. The influence of different activation (KF, KCl, KBr, K2SO4) agents onto the SERS activity of the nanomaterials was investigated, showing that the combination of a ...

  11. Following the Dynamics of pH in Endosomes of Live Cells with SERS Nanosensors

    DEFF Research Database (Denmark)

    Kneipp, J.; Kneipp, Harald; Wittig, B.

    2010-01-01

    The surface enhanced Raman scattering (SERS) spectrum of a reporter molecule attached to gold or silver nanostructures, which is pH-sensitive, can deliver information on the local pH in the environment of the nanostructure. Here, we demonstrate the use of a mobile SERS nanosensor made from gold...... nanaoaggregates and 4-mercaptobenzoic acid (pMBA) attached as a reporter for monitoring changes in local pH of the cellular compartments of living NIH/3T3 cells. We show that SERS nanosensors enable the dynamics of local pH in individual live cells to be followed at subendosomal resolution in a timeline...

  12. The ''Adatom Model'' of SERS (Surface Enhanced Raman Scattering): The present status

    International Nuclear Information System (INIS)

    Otto, A.; Billmann, J.; Eickmans, J.; Ertuerk, U.; Pettenkofer, C.

    1984-01-01

    The model predicts resonant Raman scattering by adsorbate vibrations through photon excited charge transfer transition from localized electronic states at sites of atomic scale roughness (e.g. 'adatoms') on silver surfaces to the affinity levels of the adsorbates. Experimental tests are discussed: search for the localized states, shifts of the affinity levels, comparison of SERS at sites of ASR and at atomically smooth parts of the surface, changes in SER vibrational bands by shifts of the affinity levels, 'SERS' vibrational selection rules. Infrared enhancement at sites of ASR is conjectured. Different hypotheses on the role of the 'porosity' of coldly deposited silver films are discussed. (orig.)

  13. SERS and in situ SERS spectroscopy of riboflavin adsorbed on silver, gold and copper substrates. Elucidation of variability of surface orientation based on both experimental and theoretical approach

    Science.gov (United States)

    Dendisová-Vyškovská, Marcela; Kokaislová, Alžběta; Ončák, Milan; Matějka, Pavel

    2013-04-01

    Surface-enhanced Raman scattering and in situ surface-enhanced Raman scattering spectra have been collected to study influences of (i) used metal and (ii) applied electrode potential on orientation of adsorbed riboflavin molecules. Special in situ SERS spectroelectrochemical cell was used to obtain in situ SERS spectra of riboflavin adsorbed on silver, gold and copper nanostructured surfaces. Varying electrode potential was applied in discrete steps forming a cycle from positive values to negative and backward. Observed spectral features in in situ SERS spectra, measured at alternate potentials, have been changing very significantly and the spectra have been compared with SERS spectra of riboflavin measured ex situ. Raman spectra of single riboflavin molecule in the vicinity to metal (Ag, Au and Cu) clusters have been calculated for different mutual positions. The results demonstrate significant changes of bands intensities which can be correlated with experimental spectra measured at different potentials. Thus, the orientation of riboflavin molecules adsorbed on metal surfaces can be elucidated. It is influenced definitely by the value of applied potential. Furthermore, the riboflavin adsorption orientation on the surface depends on the used metal. Adsorption geometries on the copper substrates are more diverse in comparison with the orientations on silver and gold substrates.

  14. Stimulatory effect of nobiletin, a citrus polymethoxy flavone, on catecholamine synthesis through Ser19 and Ser40 phosphorylation of tyrosine hydroxylase in cultured bovine adrenal medullary cells.

    Science.gov (United States)

    Zhang, Han; Yanagihara, Nobuyuki; Toyohira, Yumiko; Takahashi, Keita; Inagaki, Hirohide; Satoh, Noriaki; Li, Xiaoja; Goa, Xiumei; Tsutsui, Masato; Takahaishi, Kojiro

    2014-01-01

    We previously reported the dual effects of nobiletin, a compound of polymethoxy flavones found in citrus fruits, on catecholamine secretion in cultured bovine adrenal medullary cells. Here, we report the effects of nobiletin on catecholamine synthesis in the cells. Nobiletin increased the synthesis of (14)C-catecholamines from [(14)C]tyrosine in a time (20-30 min)- and concentration (1.0-100 μM)-dependent manner. Nobiletin (10-100 μM) also activated tyrosine hydroxylase activity. The stimulatory effect of nobiletin on (14)C-catecholamine synthesis was not observed when extracellular Ca(2+) was not present in the incubation medium. Protein kinase inhibitors including H-89, an inhibitor of cyclic AMP-dependent protein kinase, and KN-93, an inhibitor of Ca(2+)/calmodulin-dependent protein kinase II, suppressed the stimulatory effects of nobiletin on catecholamine synthesis as well as tyrosine hydroxylase activity. Nobiletin also induced the phosphorylation of tyrosine hydroxylase at Ser(19) and Ser(40). Nobiletin (1.0-100 μM) inhibited (14)C-catecholamine synthesis induced by acetylcholine. The present findings suggest that nobiletin, by itself, stimulates catecholamine synthesis through tyrosine hydroxylase phosphorylation at Ser(19) and Ser(40), whereas it inhibits catecholamine synthesis induced by acetylcholine in bovine adrenal medulla.

  15. La Linguistica Aplicada a la Relacion Paradigmatica entre los Verbos "Ser" y "Estar" (Linguistics Applied to the Paradigmatic Relationship between the Verbs "Ser" and "Estar")

    Science.gov (United States)

    Marchetti, Magda Ruggeri

    1977-01-01

    Speakers of Italian often have problems mastering Spanish because they erroneously believe its great similiarity to Italian makes it easy to learn. One of the fundamental problems is the lack of ability to choose the correct verb, "ser" or "estar," both equivalents of the Italian "essere." (Text is in Spanish.) (CFM)

  16. La luminosa sed: Esbozo de un itinerario de la manifestación del ser como deseo de ser al Dios deseante que viene a nuestro encuentro

    Directory of Open Access Journals (Sweden)

    Alberto Toutin

    2009-01-01

    Full Text Available En este artículo se presenta un primer atisbo de un itinerario de pensamiento que busca articular, por un lado, una comprensión de la poesía en Octavio Paz como manifestación del ser humano como apertura al otro, como deseo de ser y, por otro, la comprensión en Hans Urs von Balthasar del acontecimiento de la automanifestación de Dios, como expresión de su deseo de encuentro con el ser humano y que para ello adopta arriesgada y creativamente su lenguaje en la diversidad de sus expresiones. Con ello tan sólo queremos poner algunas bases para una poética teológica, ya iniciada tanto por Dios como por el hablar del ser humano, y que llama de ella misma a ser continuada y profundizada.In this article, the author presents a first glimpse of an itinerary of thought that seeks to articulate, on the one hand, an understanding of poetry by Octavio Paz as a manifestation of the human being as openness to the other and as desire for being and, on the other hand, Hans Urs von Balthasar's understanding of the event of God's self-manifestation as the expression of His desire to meet the human being and, to that end, adopting, with risk and creativity, the human being's language in all the diversity of its expressions. With that, the author only wants to lay some foundations for a theological poetics, already initiated as much by God as by the speech of the human being, and which calls from its own self to be continuous and deepened.

  17. Monitoring prion protein expression in complex biological samples by SERS for diagnostic applications

    International Nuclear Information System (INIS)

    Manno, D; Filippo, E; Fiore, R; Serra, A; Urso, E; Rizzello, A; Maffia, M

    2010-01-01

    Surface-enhanced Raman spectroscopy (SERS) allows a new insight into the analysis of cell physiology. In this work, the difficulty of producing suitable substrates that, besides permitting the amplification of the Raman signal, do not interact with the biological material causing alteration, has been overcome by a combined method of hydrothermal green synthesis and thermal annealing. The SERS analysis of the cell membrane has been performed with special attention to the cellular prion protein PrP C . In addition, SERS has also been used to reveal the prion protein-Cu(II) interaction in four different cell models (B104, SH-SY5Y, GN11, HeLa), expressing PrP C at different levels. A significant implication of the current work consists of the intriguing possibility of revealing and quantifying prion protein expression in complex biological samples by a cheap SERS-based method, replacing the expensive and time-consuming immuno-assay systems commonly employed.

  18. Water Ser - areng läbi torude ja üle kraavide / Ain Alvela

    Index Scriptorium Estoniae

    Alvela, Ain, 1967-

    2007-01-01

    1992. aastal asutatud vee- ja kanalisatsioonitorustike paigaldamisele spetsialiseerunud perefirma AS Water Ser on kasvanud rahvusvaheliselt mainekaks kontserniks. Vt. samas: Perefirma arengu kronoloogia; Amet sai alguse teismelise eas kraavikaevamisest. Kommenteerivad Andrus Piir ja Toomas Kapp

  19. Self-catalytic stabilized Ag-Cu nanoparticles with tailored SERS response for plasmonic photocatalysis

    Science.gov (United States)

    He, Lili; Liu, Changqing; Tang, Jia; Zhou, Youchen; Yang, Hui; Liu, Ruiyu; Hu, Jiugang

    2018-03-01

    In-situ SERS monitoring of direct plasmon-driven photocatalysis was achieved using relatively earth-abundant Cu NPs following their decoration with tiny amounts of silver, which promoted excellent SERS and high catalytic activity. The SERS and catalytic performance of the Ag-Cu NPs can be tuned by changing their composition. In particular, it was found that the surface oxidation state of copper could be switched to its metallic state via self-plasmon catalysis under laser irradiation, highlighting the potential of air-unstable copper NPs as stable plasmonic catalysts. These dual functional Ag-Cu NPs were used for SERS real-time monitoring of plasmon-driven photocatalysis reactions involving the degradation of Rhodamine 6G and the dimerization of 4-nitrothiophenol. The corresponding catalytic reaction mechanisms were discussed.

  20. Stilbazolium Merocyanine Dye Determination in Different Solutions, Concentrations and Colloids Using SERS

    DEFF Research Database (Denmark)

    Pajchrowski, Grzegorz; Abdali, Salim; Nørbygaard, Thomas

    2006-01-01

    Surface Enhanced Raman Scattering (SERS) measurements were carried out on stilbazolium merocyanine dye in methanol and pyridine solvents. Both solutions were measured in series of concentrations, covering a range of 5·10-5 M to 5·10-8 M. In these measurements Ag and Au colloids were used and the ......Surface Enhanced Raman Scattering (SERS) measurements were carried out on stilbazolium merocyanine dye in methanol and pyridine solvents. Both solutions were measured in series of concentrations, covering a range of 5·10-5 M to 5·10-8 M. In these measurements Ag and Au colloids were used...... report here on the success of using SERS to obtain Raman spectra of merocyanine dye at very low concentration in an attempt of new approach, which can be used for further investigations of the dye. The SERS spectra will here be reported and the results from different solutions, colloids, concentrations...

  1. Novel SERS materials for multiplex biomolecular detection via controlled nanoparticle linking and polymer encapsulation

    Energy Technology Data Exchange (ETDEWEB)

    Braun, G B; Lee, S J; Laurence, T; Fera, N; Fabris, L; Bazan, G C; Moskovits, M; Reich, N O

    2008-07-21

    Over the past decade the emphasis on single-molecule sensitivity of surface-enhanced Raman spectroscopy (SERS) has brought to prominence the special role played by so-called SERS 'hot spots', oftentimes nanometer-scale junctions between nanostructures. In this report, optimally SERS enhancing silver clusters were synthesized using bifunctional linkers and polymer and/or protein encapsulation. The synthesis, which results in stable clusters even when stored for months or dried and re-dissolved, is scalable to large quantities. Using a sacrificial linker approach we also employ a permeable polymer/protein shell for general small molecule sensing. Finally, we utilize these nanomaterials by tagging specific epitopes on cancer cells and show that SERS signals from single clusters can be measured routinely.

  2. [Synthesis of poly (Lys-Ser-Glu) and study of its antigenic and immunogenic properties].

    Science.gov (United States)

    Khalikov, Sh Kh; Valiev, R V; Sharetskiĭ, A N; Aristovskaia, L V

    1988-05-01

    We have synthesized oligo- and polypeptides containing lysin, serine and glutamic acid residues. Di- and tripeptides were prepared by the successive elongation of C-terminus by means of the N,N'-dicyclohexylcarbodiimide or mixed anhydride methods. The oligopeptides were obtained by block condensation of pentafluorophenyl esters of tripeptides, and polypeptides by polycondensation of dipeptide 2,4,5-trichlorophenyl esters. The three amino acids (Lys, Ser, Glu) were shown to take part in formation of antigenic determinants, serine being probably the immunodominant amino acid, and dipeptide Ser-Glu- the most important component of the epitope Lys-Ser-Glu. Polypeptides (Lys-Ser-Glu)n induced cross-reacting or heteroclitic antibodies. The expression of immune response depended on genotype of experimental animals.

  3. Characterization of copper SERS-active substrates prepared by electrochemical deposition

    Energy Technology Data Exchange (ETDEWEB)

    Cejkova, Jitka, E-mail: jitka.cejkova@vscht.cz [Institute of Chemical Technology Prague, Department of Chemical Engineering, Technicka 5, 166 28 Prague 6 (Czech Republic); Prokopec, Vadym; Brazdova, Sona; Kokaislova, Alzbeta; Matejka, Pavel [Institute of Chemical Technology Prague, Department of Analytical Chemistry, Technicka 5, 166 28 Prague 6 (Czech Republic); Stepanek, Frantisek [Institute of Chemical Technology Prague, Department of Chemical Engineering, Technicka 5, 166 28 Prague 6 (Czech Republic)

    2009-06-30

    Surface Enhanced Raman Scattering (SERS) on copper substrates of various morphologies, prepared by electrochemical deposition on platinum targets, was investigated. The substrate preparation procedures differed by the coating bath compositions, applied current densities and the duration of individual steps. The surface morphology of the substrates was visualized by means of Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). SERS spectra of selected organic thiols were measured and the relation between SERS spectral intensity and the surface structure of SERS-active substrates was studied. It has been shown that good Raman surface enhancement can be achieved on the copper substrates prepared by electrochemical deposition from ammoniac baths. Copper substrates fabricated from acidic baths did not show efficient Raman surface enhancement. The results of microscopic measurements demonstrated that the average surface roughness value does not play a substantial role, whereas the shape of the surface nanostructures is a key parameter.

  4. New SERS-active junction based on cerium dioxide facet dielectric films for biosensing

    Directory of Open Access Journals (Sweden)

    I. Kurochkin

    2014-10-01

    In this paper we investigated the possibility of the facet structures, based on cerium dioxide to further enhance the SERS signal. During the studies a new metamaterial was developed. The metamaterial is based on the facet cerium dioxide films and plasmonic nanoparticles that are immobilized on its surface. The new metamaterial provides additional SERS signal amplification factor of 211. Thus developed material offers the prospect of increasing the sensitivity and selectivity of biochemical and immunological analysis.

  5. Excellent surface-enhanced Raman scattering (SERS) based on AgFeO2 semiconductor nanoparticles

    Science.gov (United States)

    Shi, Zhijie; Wang, Tao; Lin, Haiyang; Wang, Xiuhua; Ding, Juanjuan; Shao, Mingwang

    2013-09-01

    A simple hydrothermal method was employed to synthesize AgFeO2 nanoparticles, which were utilized as substrates in SERS detection of Rhodamine 6G and 4-mercaptobenzoic acid. The magnetic properties of the products provided the capability of concentrating analyte molecules under an external magnetic field. The detection in aqueous solution has ensured the uniformity of the SERS signals and the reproducibility of the substrates. It was interesting that the substrates exhibited high SERS activity at Rhodamine 6G concentration of 1 × 10-7 M with an enhancement factor of 5.1 × 105, showing the highest SERS effect for semiconductor substrates, which might be ascribed to the orderly orientation of AgFeO2 nanoparticles under external magnetic field.A simple hydrothermal method was employed to synthesize AgFeO2 nanoparticles, which were utilized as substrates in SERS detection of Rhodamine 6G and 4-mercaptobenzoic acid. The magnetic properties of the products provided the capability of concentrating analyte molecules under an external magnetic field. The detection in aqueous solution has ensured the uniformity of the SERS signals and the reproducibility of the substrates. It was interesting that the substrates exhibited high SERS activity at Rhodamine 6G concentration of 1 × 10-7 M with an enhancement factor of 5.1 × 105, showing the highest SERS effect for semiconductor substrates, which might be ascribed to the orderly orientation of AgFeO2 nanoparticles under external magnetic field. Electronic supplementary information (ESI) available: UV-vis absorption, magnetic hysteresis loop and thermogravimetric analysis of AgFeO2, Raman spectra of 0.01 M R6G solution and 4-mercaptobenzoic acid powder. See DOI: 10.1039/c3nr03460g

  6. Fabrication of Semiconductor ZnO Nanostructures for Versatile SERS Application

    Directory of Open Access Journals (Sweden)

    Lili Yang

    2017-11-01

    Full Text Available Since the initial discovery of surface-enhanced Raman scattering (SERS in the 1970s, it has exhibited a huge potential application in many fields due to its outstanding advantages. Since the ultra-sensitive noble metallic nanostructures have increasingly exposed themselves as having some problems during application, semiconductors have been gradually exploited as one of the critical SERS substrate materials due to their distinctive advantages when compared with noble metals. ZnO is one of the most representative metallic oxide semiconductors with an abundant reserve, various and cost-effective fabrication techniques, as well as special physical and chemical properties. Thanks to the varied morphologies, size-dependent exciton, good chemical stability, a tunable band gap, carrier concentration, and stoichiometry, ZnO nanostructures have the potential to be exploited as SERS substrates. Moreover, other distinctive properties possessed by ZnO such as biocompatibility, photocatcalysis and self-cleaning, and gas- and chemo-sensitivity can be synergistically integrated and exerted with SERS activity to realize the multifunctional potential of ZnO substrates. In this review, we discuss the inevitable development trend of exploiting the potential semiconductor ZnO as a SERS substrate. After clarifying the root cause of the great disparity between the enhancement factor (EF of noble metals and that of ZnO nanostructures, two specific methods are put forward to improve the SERS activity of ZnO, namely: elemental doping and combination of ZnO with noble metals. Then, we introduce a distinctive advantage of ZnO as SERS substrate and illustrate the necessity of reporting a meaningful average EF. We also summarize some fabrication methods for ZnO nanostructures with varied dimensions (0–3 dimensions. Finally, we present an overview of ZnO nanostructures for the versatile SERS application.

  7. Fabrication of Semiconductor ZnO Nanostructures for Versatile SERS Application.

    Science.gov (United States)

    Yang, Lili; Yang, Yong; Ma, Yunfeng; Li, Shuai; Wei, Yuquan; Huang, Zhengren; Long, Nguyen Viet

    2017-11-19

    Since the initial discovery of surface-enhanced Raman scattering (SERS) in the 1970s, it has exhibited a huge potential application in many fields due to its outstanding advantages. Since the ultra-sensitive noble metallic nanostructures have increasingly exposed themselves as having some problems during application, semiconductors have been gradually exploited as one of the critical SERS substrate materials due to their distinctive advantages when compared with noble metals. ZnO is one of the most representative metallic oxide semiconductors with an abundant reserve, various and cost-effective fabrication techniques, as well as special physical and chemical properties. Thanks to the varied morphologies, size-dependent exciton, good chemical stability, a tunable band gap, carrier concentration, and stoichiometry, ZnO nanostructures have the potential to be exploited as SERS substrates. Moreover, other distinctive properties possessed by ZnO such as biocompatibility, photocatcalysis and self-cleaning, and gas- and chemo-sensitivity can be synergistically integrated and exerted with SERS activity to realize the multifunctional potential of ZnO substrates. In this review, we discuss the inevitable development trend of exploiting the potential semiconductor ZnO as a SERS substrate. After clarifying the root cause of the great disparity between the enhancement factor (EF) of noble metals and that of ZnO nanostructures, two specific methods are put forward to improve the SERS activity of ZnO, namely: elemental doping and combination of ZnO with noble metals. Then, we introduce a distinctive advantage of ZnO as SERS substrate and illustrate the necessity of reporting a meaningful average EF. We also summarize some fabrication methods for ZnO nanostructures with varied dimensions (0-3 dimensions). Finally, we present an overview of ZnO nanostructures for the versatile SERS application.

  8. Fabrication and Characterization of the US Army Research Laboratory Surface Enhanced Raman Scattering (SERS) Substrates

    Science.gov (United States)

    2017-12-04

    enhancement. The chemical enhancement occurs when there is a charge transfer resonance between the molecule and the metalized surface. These effects can also...various genes, chemical warfare species, bacteria,60,108–114 diagnostic markers, environmental pollutants , glucose monitoring,102,115 and stress...Inspired Materials 5 1.2 US Army-Relevant Applications of SERS-Hazard Detection 7 1.3 Assessing SERS Substrate: ARL/Edgewood Chemical Biological

  9. Magnetically Assembled SERS Substrates Composed of Iron-Silver Nanoparticles Obtained by Laser Ablation in Liquid.

    Science.gov (United States)

    Scaramuzza, Stefano; Badocco, Denis; Pastore, Paolo; Coral, Diego F; Fernández van Raap, Marcela B; Amendola, Vincenzo

    2017-05-05

    The widespread application of surface-enhanced Raman scattering (SERS) would benefit from simple and scalable self-assembly procedures for the realization of plasmonic arrays with a high density of electromagnetic hot-spots. To this aim, the exploitation of iron-doped silver nanoparticles (NPs) synthesized by laser ablation of a bulk bimetallic iron-silver target immersed in ethanol is described. The use of laser ablation in liquid is key to achieving bimetallic NPs in one step with a clean surface available for functionalization with the desired thiolated molecules. These iron-silver NPs show SERS performances, a ready response to external magnetic fields and complete flexibility in surface coating. All these characteristics were used for the magnetic assembly of plasmonic arrays which served as SERS substrates for the identification of molecules of analytical interest. The magnetic assembly of NPs allowed a 28-fold increase in the SERS signal of analytes compared to not-assembled NPs. The versatility of substrate preparation and the SERS performances were investigated as a function of NPs surface coating among different thiolated ligands. These results show a simple procedure to obtain magnetically assembled regenerable plasmonic arrays for repeated SERS investigation of different samples, and it can be of inspiration for the realization of other self-assembled and reconfigurable magnetic-plasmonic devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Designing multilayered nanoplatforms for SERS-based detection of genetically modified organisms

    Science.gov (United States)

    Uluok, Saadet; Guven, Burcu; Eksi, Haslet; Ustundag, Zafer; Tamer, Ugur; Boyaci, Ismail Hakki

    2015-01-01

    In this study, the multilayered surface-enhanced Raman spectroscopy (SERS) platforms were developed for the analysis of genetically modified organisms (GMOs). For this purpose, two molecules [11-mercaptoundecanoic acid (11-MUA) and 2-mercaptoethylamine (2-MEA)] were attached with Aurod and Auspherical nanoparticles to form multilayered constructions on the gold (Au)slide surface. The best multilayered platform structure was chosen depending on SERS enhancement, and this surface was characterised with atomic force microscopy (AFM) and attenuated total reflectance Fourier transform infrared spectroscopy. After the optimum multilayered SERS platform and nanoparticle interaction was identified, the oligonucleotides on the Aurod nanoparticles and Auslide were combined to determine target concentrations from the 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) signals using SERS. The correlation between the SERS intensities for DTNB and target concentrations was found to be linear within a range of 10 pM to 1 µM, and with a detection limit of 34 fM. The selectivity and specificity of the developed sandwich assay were tested using negative and positive controls, and nonsense and real sample studies. The obtained results showed that the multilayered SERS sandwich method allows for sensitive, selective, and specific detection of oligonucleotide sequences.

  11. Determination of histamine in fish by Surface Enhanced Raman Spectroscopy using silver colloid SERS substrates.

    Science.gov (United States)

    Janči, Tibor; Valinger, Davor; Gajdoš Kljusurić, Jasenka; Mikac, Lara; Vidaček, Sanja; Ivanda, Mile

    2017-06-01

    This study was focused on development of a rapid and sensitive method for histamine determination in fish based on Surface Enhanced Raman Spectroscopy (SERS) using simple and widely available silver colloid SERS substrate. Extraction of histamine with 0.4M perchloric acid and purification with 1-butanol significantly shortened sample preparation (30min) and provided clear SERS spectra with characteristic Raman bands of histamine. Principal component analysis effectively distinguished SERS spectra of fish samples with different histamine content. Partial least square (PLS) regression models confirmed reliability of detection and spectral analysis of histamine with SERS. In histamine concentration range 0-200mgkg -1 , significant in legislative and fish quality control aspects, PLS regression model based on spectral range 1139.9-1643.7cm -1 showed linear trend with R 2 pred =0.962, RPD=7.250. Presented protocol for histamine extraction and purification followed by SERS analysis coupled with chemometric approach, enabled development of rapid and inexpensive method for histamine determination in fish. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. SERS Sensors: Recent Developments and a Generalized Classification Scheme Based on the Signal Origin.

    Science.gov (United States)

    Gu, Xin; Trujillo, Michael J; Olson, Jacob E; Camden, Jon P

    2018-03-16

    Owing to its extreme sensitivity and easy execution, surface-enhanced Raman spectroscopy (SERS) now finds application for a wide variety of problems requiring sensitive and targeted analyte detection. This widespread application has prompted a proliferation of different SERS-based sensors, suggesting the need for a framework to classify existing methods and guide the development of new techniques. After a brief discussion of the general SERS modalities, we classify SERS-based sensors according the origin of the signal. Three major categories emerge from this analysis: surface-affinity strategy, SERS-tag strategy, and probe-mediated strategy. For each case, we describe the mechanism of action, give selected examples, and point out general misconceptions to aid the construction of new devices.Wehope this review serves as a useful tutorial guide and helps readers to better classify and design practical and effective SERS-based sensors. Expected final online publication date for the Annual Review of Analytical Chemistry Volume 11 is June 12, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  13. Label-free SERS in biological and biomedical applications: Recent progress, current challenges and opportunities.

    Science.gov (United States)

    Zheng, Xiao-Shan; Jahn, Izabella Jolan; Weber, Karina; Cialla-May, Dana; Popp, Jürgen

    2018-05-15

    To achieve an insightful look within biomolecular processes on the cellular level, the development of diseases as well as the reliable detection of metabolites and pathogens, a modern analytical tool is needed that is highly sensitive, molecular-specific and exhibits fast detection. Surface-enhanced Raman spectroscopy (SERS) is known to meet these requirements and, within this review article, the recent progress of label-free SERS in biological and biomedical applications is summarized and discussed. This includes the detection of biomolecules such as metabolites, nucleic acids and proteins. Further, the characterization and identification of microorganisms has been achieved by label-free SERS-based approaches. Eukaryotic cells can be characterized by SERS in order to gain information about the outer cell wall or to detect intracellular molecules and metabolites. The potential of SERS for medically relevant detection schemes is emphasized by the label-free detection of tissue, the investigation of body fluids as well as applications for therapeutic and illicit drug monitoring. The review article is concluded with an evaluation of the recent progress and current challenges in order to highlight the direction of label-free SERS in the future. Copyright © 2018. Published by Elsevier B.V.

  14. Aluminum nanostructures with strong visible-range SERS activity for versatile micropatterning of molecular security labels.

    Science.gov (United States)

    Lay, Chee Leng; Koh, Charlynn Sher Lin; Wang, Jing; Lee, Yih Hong; Jiang, Ruibin; Yang, Yijie; Yang, Zhe; Phang, In Yee; Ling, Xing Yi

    2018-01-03

    The application of aluminum (Al)-based nanostructures for visible-range plasmonics, especially for surface-enhanced Raman scattering (SERS), currently suffers from inconsistent local electromagnetic field distributions and/or inhomogeneous distribution of probe molecules. Herein, we lithographically fabricate structurally uniform Al nanostructures which enable homogeneous adsorption of various probe molecules. Individual Al nanostructures exhibit strong local electromagnetic field enhancements, in turn leading to intense SERS activity. The average SERS enhancement factor (EF) for individual nanostructures exceeds 10 4 for non-resonant probe molecules in the visible spectrum. These Al nanostructures also retain more than 70% of their original SERS intensities after one-month storage, displaying superb stability under ambient conditions. We further achieve tunable polarization-dependent SERS responses using anisotropic Al nanostructures, facilitating the design of sophisticated SERS-based security labels. Our micron-sized security label comprises two-tier security features, including a machine-readable hybrid quick-response (QR) code overlaid with a set of ciphertexts. Our work demonstrates the versatility of Al-based structures in low-cost modern chemical nano-analytics and forgery protection.

  15. Surface enhanced Raman spectroscopy (SERS) for in vitro diagnostic testing at the point of care

    Science.gov (United States)

    Marks, Haley; Schechinger, Monika; Garza, Javier; Locke, Andrea; Coté, Gerard

    2017-06-01

    Point-of-care (POC) device development is a growing field that aims to develop low-cost, rapid, sensitive in-vitro diagnostic testing platforms that are portable, self-contained, and can be used anywhere - from modern clinics to remote and low resource areas. In this review, surface enhanced Raman spectroscopy (SERS) is discussed as a solution to facilitating the translation of bioanalytical sensing to the POC. The potential for SERS to meet the widely accepted "ASSURED" (Affordable, Sensitive, Specific, User-friendly, Rapid, Equipment-free, and Deliverable) criterion provided by the World Health Organization is discussed based on recent advances in SERS in vitro assay development. As SERS provides attractive characteristics for multiplexed sensing at low concentration limits with a high degree of specificity, it holds great promise for enhancing current efforts in rapid diagnostic testing. In outlining the progression of SERS techniques over the past years combined with recent developments in smart nanomaterials, high-throughput microfluidics, and low-cost paper diagnostics, an extensive number of new possibilities show potential for translating SERS biosensors to the POC.

  16. Designing multilayered nanoplatforms for SERS-based detection of genetically modified organisms

    Energy Technology Data Exchange (ETDEWEB)

    Uluok, Saadet [Dumlupinar University, Department of Chemistry, Faculty of Arts and Sciences (Turkey); Guven, Burcu [Hacettepe University, Department of Food Engineering, Faculty of Engineering (Turkey); Eksi, Haslet [Hacettepe University, Food Research Center (Turkey); Ustundag, Zafer [Dumlupinar University, Department of Chemistry, Faculty of Arts and Sciences (Turkey); Tamer, Ugur [Gazi University, Department of Analytical Chemistry, Faculty of Pharmacy (Turkey); Boyaci, Ismail Hakki, E-mail: ihb@hacettepe.edu.tr [Hacettepe University, Department of Food Engineering, Faculty of Engineering (Turkey)

    2015-01-15

    In this study, the multilayered surface-enhanced Raman spectroscopy (SERS) platforms were developed for the analysis of genetically modified organisms (GMOs). For this purpose, two molecules [11-mercaptoundecanoic acid (11-MUA) and 2-mercaptoethylamine (2-MEA)] were attached with Au{sub rod} and Au{sub spherical} nanoparticles to form multilayered constructions on the gold (Au){sub slide} surface. The best multilayered platform structure was chosen depending on SERS enhancement, and this surface was characterised with atomic force microscopy (AFM) and attenuated total reflectance Fourier transform infrared spectroscopy. After the optimum multilayered SERS platform and nanoparticle interaction was identified, the oligonucleotides on the Au{sub rod} nanoparticles and Au{sub slide} were combined to determine target concentrations from the 5,5′-dithiobis (2-nitrobenzoic acid) (DTNB) signals using SERS. The correlation between the SERS intensities for DTNB and target concentrations was found to be linear within a range of 10 pM to 1 µM, and with a detection limit of 34 fM. The selectivity and specificity of the developed sandwich assay were tested using negative and positive controls, and nonsense and real sample studies. The obtained results showed that the multilayered SERS sandwich method allows for sensitive, selective, and specific detection of oligonucleotide sequences.

  17. Label-free SERS in biological and biomedical applications: Recent progress, current challenges and opportunities

    Science.gov (United States)

    Zheng, Xiao-Shan; Jahn, Izabella Jolan; Weber, Karina; Cialla-May, Dana; Popp, Jürgen

    2018-05-01

    To achieve an insightful look within biomolecular processes on the cellular level, the development of diseases as well as the reliable detection of metabolites and pathogens, a modern analytical tool is needed that is highly sensitive, molecular-specific and exhibits fast detection. Surface-enhanced Raman spectroscopy (SERS) is known to meet these requirements and, within this review article, the recent progress of label-free SERS in biological and biomedical applications is summarized and discussed. This includes the detection of biomolecules such as metabolites, nucleic acids and proteins. Further, the characterization and identification of microorganisms has been achieved by label-free SERS-based approaches. Eukaryotic cells can be characterized by SERS in order to gain information about the outer cell wall or to detect intracellular molecules and metabolites. The potential of SERS for medically relevant detection schemes is emphasized by the label-free detection of tissue, the investigation of body fluids as well as applications for therapeutic and illicit drug monitoring. The review article is concluded with an evaluation of the recent progress and current challenges in order to highlight the direction of label-free SERS in the future.

  18. Reproducible E. coli detection based on label-free SERS and mapping.

    Science.gov (United States)

    Yang, Danting; Zhou, Haibo; Haisch, Christoph; Niessner, Reinhard; Ying, Yibin

    2016-01-01

    The biosensing for rapid detection of bacteria based on surface-enhanced Raman scattering (SERS) has been widely explored for recent years. It is still a challenge to achieve a high sensitive, reproducible label free detection method for bacteria. In this work, a label-free SERS detection method of Escherichia coli based on incubation with silver colloid was reported. Optimized incubation conditions including shaking speed, time and temperature were used to help construct a rapid SERS method for E. coli analysis. It was found that the enhancement of the Raman signal of E. coli could be achieved to 1.8×10(4) cps (counts per second) with high reproducibility. Three strains of E. coli DSM 1116/498/5695 could be successfully discriminated using such SERS method combining discriminant analysis. Finally, the lowest concentration of E. coli at 1×10(5) cell/mL can be detected by SERS mapping. Thus, our detection method offers higher sensitivity and reproducibility compared to previously reported label free simple-mixing methods, opening an avenue for developing various SERS-based biosensor. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Surface enhanced Raman spectroscopy (SERS for in vitro diagnostic testing at the point of care

    Directory of Open Access Journals (Sweden)

    Marks Haley

    2017-06-01

    Full Text Available Point-of-care (POC device development is a growing field that aims to develop low-cost, rapid, sensitive in-vitro diagnostic testing platforms that are portable, self-contained, and can be used anywhere – from modern clinics to remote and low resource areas. In this review, surface enhanced Raman spectroscopy (SERS is discussed as a solution to facilitating the translation of bioanalytical sensing to the POC. The potential for SERS to meet the widely accepted “ASSURED” (Affordable, Sensitive, Specific, User-friendly, Rapid, Equipment-free, and Deliverable criterion provided by the World Health Organization is discussed based on recent advances in SERS in vitro assay development. As SERS provides attractive characteristics for multiplexed sensing at low concentration limits with a high degree of specificity, it holds great promise for enhancing current efforts in rapid diagnostic testing. In outlining the progression of SERS techniques over the past years combined with recent developments in smart nanomaterials, high-throughput microfluidics, and low-cost paper diagnostics, an extensive number of new possibilities show potential for translating SERS biosensors to the POC.

  20. Nefropatía diabética incipiente en una población mediterránea: análisis del riesgo cardiovascular y estudio de intervención farmacológica sobre la progresión a nefropatía avanzada.

    OpenAIRE

    Pérez Maraver, Manuel

    2005-01-01

    DELIMITACIÓN DE OBJETIVOS E HIPÓTESIS DE TRABAJO: La hipótesis es doble en relación a los dos aspectos clínicamente más relevantes de la nefropatía diabética inicial en la diabetes tipo 2: el riesgo cardiovascular y la progresión a nefropatía avanzada.1- La nefropatía diabética inicial (micro y macroalbuminuria) en pacientes con diabetes tipo 2 se asocia con un riesgo de enfermedad cardiovascular superior al de la población diabética sin nefropatía, también en una comunidad de bajo riesgo car...

  1. Transparent and Flexible Surface-Enhanced Raman Scattering (SERS) Sensors Based on Gold Nanostar Arrays Embedded in Silicon Rubber Film.

    Science.gov (United States)

    Park, Seungyoung; Lee, Jiwon; Ko, Hyunhyub

    2017-12-20

    Integration of surface-enhanced Raman scattering (SERS) sensors onto transparent and flexible substrates enables lightweight and deformable SERS sensors which can be wrapped or swabbed on various nonplanar surfaces for the efficient collection and detection of analytes on various surfaces. However, the development of transparent and flexible SERS substrates with high sensitivity is still challenging. Here, we demonstrate a transparent and flexible SERS substrate with high sensitivity based on a polydimethylsiloxane (PDMS) film embedded with gold nanostar (GNS) assemblies. The flexible SERS substrates enable conformal coverage on arbitrary surfaces, and the optical transparency allows light interaction with the underlying contact surface, thereby providing highly sensitive detection of analytes adsorbed on arbitrary metallic and dielectric surfaces which otherwise do not provide any noticeable Raman signals of analytes. In particular, when the flexible SERS substrates are covered onto metallic surfaces, the SERS enhancement is greatly improved because of the additional plasmon couplings between GNS and metal film. We achieve the detection capability of a trace amount of benzenethiol (10 -8 M) and enormous SERS enhancement factor (∼1.9 × 10 8 ) for flexible SERS substrates on Ag film. In addition, because of the embedded structure of GNS monolayers within the PDMS film, SERS sensors maintain the high sensitivity even after mechanical deformations of stretching, bending, and torsion for 100 cycles. The transparent and flexible SERS substrates introduced in this study are applicable to various SERS sensing applications on nonplanar surfaces, which are not achievable for hard SERS substrates.

  2. Aging reveals a role for nigral tyrosine hydroxylase ser31 phosphorylation in locomotor activity generation.

    Directory of Open Access Journals (Sweden)

    Michael F Salvatore

    Full Text Available BACKGROUND: Tyrosine hydroxylase (TH regulates dopamine (DA bioavailability. Its product, L-DOPA, is an established treatment for Parkinson's disease (PD, suggesting that TH regulation influences locomotion. Site-specific phosphorylation of TH at ser31 and ser40 regulates activity. No direct evidence shows that ser40 phosphorylation is the dominating mechanism of regulating TH activity in vivo, and physiologically-relevant stimuli increase L-DOPA biosynthesis independent of ser40 phosphorylation. Significant loss of locomotor activity occurs in aging as in PD, despite less loss of striatal DA or TH in aging compared to the loss associated with symptomatic PD. However, in the substantia nigra (SN, there is equivalent loss of DA or TH in aging and at the onset of PD symptoms. Growth factors increase locomotor activity in both PD and aging models and increase DA bioavailability and ser31 TH phosphorylation in SN, suggesting that ser31 TH phosphorylation status in the SN, not striatum, regulates DA bioavailability necessary for locomotor activity. METHODOLOGY AND PRINCIPAL FINDINGS: We longitudinally characterized locomotor activity in young and older Brown-Norway Fischer 344 F(1 hybrid rats (18 months apart in age at two time periods, eight months apart. The aged group served as an intact and pharmacologically-naïve source of deficient locomotor activity. Following locomotor testing, we analyzed DA tissue content, TH protein, and TH phosphorylation in striatum, SN, nucleus accumbens, and VTA. Levels of TH protein combined with ser31 phosphorylation alone reflected inherent differences in DA levels among the four regions. Measures strictly pertaining to locomotor activity initiation significantly correlated to DA content only in the SN. Nigral TH protein and ser31 phosphorylation together significantly correlated to test subject's maximum movement number, horizontal activity, and duration. CONCLUSIONS/SIGNIFICANCE: Together, these results show ser

  3. Signal enhancement ratio (SER) quantified from breast DCE-MRI and breast cancer risk

    Science.gov (United States)

    Wu, Shandong; Kurland, Brenda F.; Berg, Wendie A.; Zuley, Margarita L.; Jankowitz, Rachel C.; Sumkin, Jules; Gur, David

    2015-03-01

    Breast magnetic resonance imaging (MRI) is recommended as an adjunct to mammography for women who are considered at elevated risk of developing breast cancer. As a key component of breast MRI, dynamic contrast-enhanced MRI (DCE-MRI) uses a contrast agent to provide high intensity contrast between breast tissues, making it sensitive to tissue composition and vascularity. Breast DCE-MRI characterizes certain physiologic properties of breast tissue that are potentially related to breast cancer risk. Studies have shown that increased background parenchymal enhancement (BPE), which is the contrast enhancement occurring in normal cancer-unaffected breast tissues in post-contrast sequences, predicts increased breast cancer risk. Signal enhancement ratio (SER) computed from pre-contrast and post-contrast sequences in DCE-MRI measures change in signal intensity due to contrast uptake over time and is a measure of contrast enhancement kinetics. SER quantified in breast tumor has been shown potential as a biomarker for characterizing tumor response to treatments. In this work we investigated the relationship between quantitative measures of SER and breast cancer risk. A pilot retrospective case-control study was performed using a cohort of 102 women, consisting of 51 women who had diagnosed with unilateral breast cancer and 51 matched controls (by age and MRI date) with a unilateral biopsy-proven benign lesion. SER was quantified using fully-automated computerized algorithms and three SER-derived quantitative volume measures were compared between the cancer cases and controls using logistic regression analysis. Our preliminary results showed that SER is associated with breast cancer risk, after adjustment for the Breast Imaging Reporting and Data System (BI-RADS)-based mammographic breast density measures. This pilot study indicated that SER has potential for use as a risk factor for breast cancer risk assessment in women at elevated risk of developing breast cancer.

  4. A Nanosensor for Explosives Detection Based on Molecularly Imprinted Polymers (MIPs) and Surfaced-enhanced Raman Scattering (SERS)

    Science.gov (United States)

    2010-03-01

    Controlling Film Thickness The xerogels were spun cast as thin films onto purchased Klarite SERS substrates using a spin coater . SERS enhancement is known to...different (a) volumes and (b) spinning speeds. ..........................................................................5 Figure 3. SERS spectra of...controlled. In order to determine the optimal thickness, the volume and spin deposition rate of the sol solutions was optimized. Figure 2a presents

  5. Modos de ser enfermeiro-professor-no-ensino-do-cuidadode-enfermagem: um olhar heideggeriano

    Directory of Open Access Journals (Sweden)

    Luciara Fabiane Sebold

    2013-08-01

    Full Text Available Estudo qualitativo de abordagem fenomenológica. Objetivou desvelar, à luz do pensamento de Martin Heidegger, os modos de ser dos enfermeiros-professores na vivência de ensinar-aprender o cuidado de enfermagem em uma instituição federal de ensino superior do sul do Brasil. A técnica utilizada para captar os significados foi a entrevista fenomenológica com 11 docentes. A análise permitiu compreender os Modos de Ser enfermeiro-professor, que foram didaticamente apresentados em duas unidades de significado: Modo de ser enfermeiro para o cuidado; Modo de ser professor para o ensino do cuidado. Alguns professores identificam-se como enfermeiros, suas experiências profissionais são suas bases e a coexistência com outros pôde lhes servir de exemplo. Outros se percebem professores de enfermagem e desejam ensinar os desafios de ser enfermeiro, e aprimoram o cuidado através de pesquisas. Ao ensinar, envolvem-se com o universo de ensino no qual o cuidar também é aprender e ensinar.

  6. Trace determination of thiram using SERS-active hollow sea-urchin gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guanghui; Zhang, Chuankun, E-mail: zhangchk-lx@huat.edu.cn; Ma, Yanan; Wang, Zheng; Wang, Shun; Xu, Chan; Wang, Dashuang [Hubei University of Automotive Technology, School of Science (China)

    2017-04-15

    Surface-enhanced Raman scattering (SERS) is greatly structure-dependent on the absorbed nanoparticles. Nanostructures with different novel morphologies show different Raman enhancement factor orders of magnitude. Herein, a unique nanostructure with fruitful SERS-active sites, composed of hollow interiors and thorns which named as hollow sea-urchin gold nanoparticles (HSU-GNPs), was synthesized by using a one-pot galvanic replacement method. And the corresponding morphologies and optical properties were characterized by TEM images and absorption spectra. Importantly, the synthetic parameters of HSU-GNPs were optimized to obtain a superior SERS performance by analyzing the formation mechanism and the SERS spectra of R6G-labeled HSU-GNPs which obtained at different concentrations of AgNO{sub 3}. Furthermore, the SERS-based application of HSU-GNPs was performed on the dose-response detection of thiram. The experimental result shows this detection strategy is available for thiram with decent sensitivity and reproducibility, which suggests that it is an excellent candidate for the detection of pesticides.

  7. Ag Nanorod Arrays for SERS: Aspects of Spectral Reproducibility, Surface Contamination, and Spectral Sensitivity

    Directory of Open Access Journals (Sweden)

    Martin Šubr

    2015-01-01

    Full Text Available Ag nanorod arrays prepared by oblique angle vapor deposition (OAD represent regular, large area substrates for surface-enhanced Raman scattering (SERS spectroscopy. We studied uniformity and spectral reproducibility of silver OAD-fabricated substrates (AgOADs by spectral mapping of methylene blue. The results demonstrate good reproducibility apart from occasional “hot-spot” sites where the intensity is higher. The number of “hot-spots” represents 2%–6% of SERS-active sites of mapping substrate area. We were able to obtain good SERS spectra of testing amino acid tryptophan at 1 × 10−5 M concentration and three different free-base porphyrins down to ∼10−7 M concentration. We found out that keeping the AgOADs in a vacuum chamber overnight prevents the surface from binding any contaminants from the ambient atmosphere, without significant reduction in the SERS enhancement. Such substrates provide stable SERS enhancement even when stored for 1 year after preparation.

  8. Mixing Assisted "Hot Spots" Occupying SERS Strategy for Highly Sensitive In Situ Study.

    Science.gov (United States)

    Lu, Hui; Zhu, Li; Zhang, Chuanlong; Chen, Kexiang; Cui, Yiping

    2018-03-20

    To solve the problem that analyte molecules cannot easily enter "hot spots" on a conventional solid SERS substrate, we developed a mixing-assisted "hot spots" occupying (MAHSO) SERS strategy to improve utilization of "hot spots". Compared with the conventional substrate, the MAHSO substrate enhances the sensitivity of SERS measurement by thousands of times. The MAHSO substrate possesses excellent properties of high enhancement, high uniformity, and long-term stability because the MAHSO substrate is integrated inside an ultrafast microfluidic mixer. The mixer makes analytes and metal colloid homogeneously mixed, and analytes are naturally located in "hot spots", the gaps between adjacent NPs, during the process that NPs deposit on the channel wall. As a multi-inlet device, the MAHSO chip offers a convenient in situ method to study environmental effects on analytes or molecular interactions by flexibly regulating fluid in microchannels and monitoring responses of analytes by SERS spectra. Because all experiments are conducted in aqueous environments, which is similar to the physiological conditions, the MAHSO chip is especially suitable to be applied to study biomolecules. Using this strategy, different conformational changes of the wild type and mutant G150D of protein PMP22-TM4 depending on environmental pH have been observed in situ and analyzed. As a lab-on-a-chip (LoC) device, the MAHSO SERS chip will benefit the field of molecular dynamics, as well as molecule-molecule or molecule-surface interactions in the future.

  9. Use of Polycrystalline Ice for Assembly of Large Area Au Nanoparticle Superstructures as SERS Substrates.

    Science.gov (United States)

    Bekana, Deribachew; Liu, Rui; Amde, Meseret; Liu, Jing-Fu

    2017-01-11

    It is still a great challenge to develop simple and low-cost methods for preparation of surface-enhanced Raman scattering (SERS) substrates with high sensitivity and reproducibility. Taking advantage of the microstructure of polycrystalline ice, we developed a new method to assemble large area gold nanoparticle (AuNP) superstructures as SERS substrates without external templating and aggregating agent. The assembly was conducted by freezing AuNP colloid at -20 °C, which concentrated AuNPs in the ice veins and produced an AuNP superstructure upon thawing the ice. The AuNP superstructures exhibited high SERS activity with enhancement factors on the order of 7.63 × 10 7 owing to the high-density hot spots throughout the superstructures. The SERS activity was found to increase with particle size and aggregate size of AuNP superstructures. Besides, the substrates showed good uniformity and reproducibility with relative standard deviations of 11.9% and 12.4%, respectively. The substrates showed long-term stability, maintaining SERS activity over a period of five months without noticeable change in morphology of the superstructures. The substrates was further used for label-free detection of trace Thiram on apple fruit with high sensitivity down to the concentration of 0.28 ng/cm 2 , offering great potential to monitor Thiram levels in foodstuffs and environmental samples.

  10. Paper based Flexible and Conformal SERS Substrate for Rapid Trace Detection on Real-world Surfaces

    Science.gov (United States)

    Singamaneni, Srikanth; Lee, Chang; Tian, Limei

    2011-03-01

    One of the important but often overlooked considerations in the design of surface enhanced Raman scattering (SERS) substrates for trace detection is the efficiency of sample collection. Conventional designs based on rigid substrates such as silicon, alumina, and glass resist conformal contact with the surface under investigation, making the sample collection inefficient. We demonstrate a novel SERS substrate based on common filter paper adsorbed with gold nanorods, which allows conformal contact with real-world surfaces, thus dramatically enhancing the sample collection efficiency compared to conventional rigid substrates. We demonstrate the detection of trace amounts of analyte (140 pg spread over 4 cm2) by simply swabbing the surface under investigation with the novel SERS substrate. The hierarchical fibrous structure of paper serves as a 3D vasculature for easy uptake and transport of the analytes to the electromagnetic hot spots in the paper. Simple yet highly efficient and cost effective SERS substrate demonstrated here brings SERS based trace detection closer to real-world applications. We acknowledge the financial support from Center for Materials Innovation at Washington University.

  11. Commercial Gold Nanoparticles on Untreated Aluminum Foil: Versatile, Sensitive, and Cost-Effective SERS Substrate

    Directory of Open Access Journals (Sweden)

    Kristina Gudun

    2017-01-01

    Full Text Available We introduce low-cost, tunable, hybrid SERS substrate of commercial gold nanoparticles on untreated aluminum foil (AuNPs@AlF. Two or three AuNP centrifugation/resuspension cycles are proven to be critical in the assay preparation. The limits of detection (LODs for 4-nitrobenzenethiol (NBT and crystal violet (CV on this substrate are about 0.12 nM and 0.19 nM, respectively, while maximum analytical SERS enhancement factors (AEFs are about 107. In comparative assays LODs for CV measured on AuNPs@Au film and AuNPs@glass are about 0.35 nM and 2 nM, respectively. The LOD for melamine detected on AuNPs@ Al foil is 27 ppb with 3 orders of magnitude for linear response range. Overall, AuNPs@AlF demonstrated competitive performance in comparison with AuNPs@ Au film substrate in SERS detection of CV, NBT, and melamine. To check the versatility of the AuNPs@AlF substrate we also detected KNO3 with LODs of 0.7 mM and SERS EF around 2 × 103, which is on the same order with SERS EF reported for this compound in the literature.

  12. Theoretical calculation (DFT), Raman and surface-enhanced Raman scattering (SERS) study of ponceau 4R

    Science.gov (United States)

    Xie, Yunfei; Li, Yan; Sun, Yingying; Wang, Heya; Qian, He; Yao, Weirong

    2012-10-01

    Ponceau 4R is used as a coloring agent in many different products, such as food, drinks, medicines, cosmetics and tobacco. However, ponceau 4R also shows carcinogenic, teratogenic and mutagenic behavior in high doses. In this work, standard Raman, theoretical Raman and surface-enhanced Raman scattering (SERS) spectra have been used to investigate ponceau 4R. More specifically, density functional theory (DFT) calculations have been used to calculate the optimized Raman spectrum of ponceau 4R at the B3LYP/6-31G(d) level. This has provided a better understanding of the optimized geometry and vibrational frequencies of this dye. In addition, the experimental spectrum of ponceau 4R has been compared with the theoretical spectrum; good agreement was obtained. Finally, it has shown that using SERS the detection limit of the ponceau 4R solution can be as low as 5 μg/mL. This has been achieved by SERS measurements of ponceau 4R on a substrate of gold nanoparticles. The SERS peaks at 1030, 1236, 1356 and 1502 cm-1 were chosen as index for semi-quantitative analysis, showing that the SERS technique provided a useful ultrasensitive method for the detection of ponceau 4R.

  13. Micro-nano zinc oxide film fabricated by biomimetic mineralization: Designed architectures for SERS substrates

    Science.gov (United States)

    Lu, Fei; Guo, Yue; Wang, Yunxin; Song, Wei; Zhao, Bing

    2018-05-01

    In this study, we have investigated the effect of the surface morphologies of the zinc oxide (ZnO) substrates on surface enhanced Raman spectroscopy (SERS). During synthetic process, the self-assembly monolayers (SAMs) with different terminal groups are used as templates to induce the nucleation and growth of Zn(NO3)2·6H2O crystals, then different morphologies micro-nano ZnO powders are obtained by annealing Zn(NO3)2·6H2O crystals at 450 °C. The products obtained at different conditions are characterized by means of X-ray diffraction (XRD) patterns, scanning electron microscopy (SEM) and Raman spectra. The as-prepared ZnO micro-sized particles have been used the efficient Surface enhanced Raman scattering (SERS) substrates, and the SERS signals of 4-mercaptopyridine (Mpy) probe molecules are much influenced by the morphologies of the ZnO structures. Results indicated that the more (0001) facets appear in the of ZnO morphology, the greater degree of charge-transfer (PCT) for the SERS enhancement on the surface of semiconductors is achieved. The chemical interaction between ZnO structures and Mpy molecules plays a very important role in the SERS enhancement.

  14. Trace determination of thiram using SERS-active hollow sea-urchin gold nanoparticles

    Science.gov (United States)

    Zhang, Guanghui; Zhang, Chuankun; Ma, Yanan; Wang, Zheng; Wang, Shun; Xu, Chan; Wang, Dashuang

    2017-04-01

    Surface-enhanced Raman scattering (SERS) is greatly structure-dependent on the absorbed nanoparticles. Nanostructures with different novel morphologies show different Raman enhancement factor orders of magnitude. Herein, a unique nanostructure with fruitful SERS-active sites, composed of hollow interiors and thorns which named as hollow sea-urchin gold nanoparticles (HSU-GNPs), was synthesized by using a one-pot galvanic replacement method. And the corresponding morphologies and optical properties were characterized by TEM images and absorption spectra. Importantly, the synthetic parameters of HSU-GNPs were optimized to obtain a superior SERS performance by analyzing the formation mechanism and the SERS spectra of R6G-labeled HSU-GNPs which obtained at different concentrations of AgNO3. Furthermore, the SERS-based application of HSU-GNPs was performed on the dose-response detection of thiram. The experimental result shows this detection strategy is available for thiram with decent sensitivity and reproducibility, which suggests that it is an excellent candidate for the detection of pesticides.

  15. Application of silver nanodendrites deposited on silicon in SERS technique for the trace analysis of paraquat

    Science.gov (United States)

    Cao Dao, Tran; Quynh Ngan Luong, Truc; Cao, Tuan Anh; Kieu, Ngoc Minh; Le, Van Vu

    2016-03-01

    In order to detect trace concentrations of organic or biological molecules by surface-enhanced Raman scattering (SERS) technique, the SERS-active substrates with high enhancement factor are required. The silver nanodendrites (AgNDs) are a growing class of such SERS-active substrates. This report presents the preliminary results of the trace detection of paraquat (PQ), a commonly used herbicide, with the use of SERS-active substrates, which have been made from AgNDs deposited on silicon. The AgNDs were produced either by electroless deposition, or by electrodeposition onto a silicon wafer, using aqueous solution of HF and AgNO3. It was observed that the silver dendrites are formed only when AgNO3 concentration is high enough. Next, it was found that with the additional assistance of an electric potential in the electrodeposition, the dendrites have grown up with the more perfect ramification. The AgNDs with more perfect branching gave the Raman spectrum of PQ with higher enhancement factor. More specifically, while the SERS-active substrates prepared from electrodeposited AgNDs were able to detect PQ with concentration as low as 0.01 ppm, the ones made from electroless deposited AgNDs could only detect PQ at concentration of hundreds times higher.

  16. Espacialidade do ser-profissional-de-enfermagem no mundo do cuidado à criança que tem câncer Especialidad del ser profesional de enfermería en el mundo del cuidado al niño que tiene cáncer Spaciality of being-nursing-professional in the world of caring to children who has cancer

    Directory of Open Access Journals (Sweden)

    Cintia Flores Mutti

    2012-09-01

    Full Text Available OBJETIVO: compreender o significado para equipe de enfermagem de cuidar de crianças que têm doença oncológica avançada, cuja enfermidade não responde mais aos tratamentos curativos. MÉTODO: Investigação fenomenológica heideggeriana. Etapa de campo desenvolvida no período de dezembro/2010 a março/2011, com 15 profissionais de enfermagem no Hospital Universitário de Santa Maria, Rio Grande do Sul, Brasil. RESULTADOS: O profissional de enfermagem expressa que, no cotidiano de cuidado à criança que tem câncer, tem que separar o profissional do emocional. Descreve o seu dia a dia dentro e fora do hospital. Com o tempo, aprende a separar o trabalho da vida pessoal. CONCLUSÕES: Aponta a necessidade do desenvolvimento de estratégias de ação multiprofissional entre a equipe que cuida, considerando que também precisa ser cuidada.OBJETIVO: comprender el significado para el equipo de enfermería de atención a niños que tienen enfermedad oncológica avanzada, cuya enfermedad no responde más a los tratamientos curativos. MÉTODO: Investigación fenomenológica heideggeriana. Etapa de campo desarrollada en el período de diciembre/2010 a marzo/2011, con 15 profesionales de enfermería en el Hospital Universitario de Santa Maria, Rio Grande do Sul, Brasil. RESULTADOS: El profesional de enfermería expresa que, en el cotidiano de cuidado al niño que tiene cáncer, tiene que separar el profesional del emocional. Describe su rutina dentro y fuera del hospital. Con el tiempo aprende a separar el trabajo de la vida profesional. CONCLUSIONES: Apunta la necesidad del desarrollo de estrategias de acción multiprofesional entre el equipo que cuida, considerando que también necesita atención.OBJECTIVE: to comprehend the meaning of taking care of children who have an advanced cancer that no longer responds to curative treatments for nursing staff. METHODS: heideggerian phenomenological research. Field step developed from December/2010 to March

  17. Fe2O3-Au hybrid nanoparticles for sensing applications via sers analysis

    International Nuclear Information System (INIS)

    Murph, Simona Hunyadi; Searles, Emily

    2017-01-01

    Nanoparticles with large amounts of surface area and unique characteristics that are distinct from their bulk material provide an interesting application in the enhancement of inelastic scattering signal. Surface Enhanced Raman Spectroscopy (SERS) strives to increase the Raman scattering effect when chemical species of interest are in the close proximity of metallic nnaostructures. Gold nanoparticles of various shapes have been used for sensing applications via SERS as they demonstrate the greatest effect of plasmonic behavior in the visible-near IR region of the spectrum. When coupled with other nanoparticles, namely iron oxide nanoparticles, hybrid structures with increased functionality were produced. Multifunctional iron oxide-gold hybrid nanostructures have been created via solution chemistries and investigated for analyte detection of a model analyte. By exploiting their magnetic properties, nanogaps or “hot spots” were rationally created and evaluated for SERS enhancement studies.

  18. Acerca de la doctrina de la indestructibilidad de nuestro verdadero ser por la muerte

    OpenAIRE

    Schopenhauer, Arthur

    2010-01-01

    "Acerca de la doctrina de la indestructibilidad de nuestro verdadero ser por la muerte" es un escrito complementario del famoso capítulo 41 del Tomo II de El mundo como voluntad y representación, que lleva el paradójico título: "Sobre la muerte y su relación con la indestructibilidad de nuestro ser en sí" . El título es paradójico porque Schopenhauer habla de "nuestro ser en sí" y no parece fácilmente concebible la adscripción del posesivo"nuestro" a lo que"es en sí", o sea, a lo que existe i...

  19. In situ synthesis of Ag nanoparticles-graphene oxide nanocomposites with strong SERS activity

    Science.gov (United States)

    Shi, Zengliang; Hao, Xiaolong; Xu, Chunxiang

    2018-01-01

    Without any capping agents or multistep process, a simple and green method for in situ synthesis of the Ag nanoparticles-graphene oxide sheets (Ag NPs-GO) nanocomposites was proposed. The Ag NPs were well-distributed on the surface of the GO sheets with a uniform size. The formation mechanism of the resulting nanocomposites was discussed. The presence of Ag NPs enhanced the Raman signal of GO in the resulting nanocomposites with an enhancement factor (EF) of 43. The resulting nanocomposites exhibited strong surface-enhanced Raman scattering (SERS) activity toward rhodamine 6G (R6G) with an EF of 1.4 × 107. The synergistic effects of the R6G molecules adsorbed on GO sheets and the coupled EM field caused by the Ag NPs lead to the significant SERS enhancement. This result makes the resulting Ag NPs-GO nanocomposites a more promising SERS substrate.

  20. Investigation of particle shape and size effects in SERS using T-matrix calculations.

    Science.gov (United States)

    Boyack, Rufus; Le Ru, Eric C

    2009-09-14

    The influence of particle size and shape effects on average and punctual surface-enhanced Raman scattering (SERS) enhancement factors (EFs) is investigated using exact T-matrix electrodynamic calculations of silver and gold spheroids over a large parameter space. This study extends the conventional treatment of these effects within the frameworks of the electrostatics approximation, its generalizations, or Mie theory for spheres. It confirms the qualitative features of these approaches, but provides in addition quantitative predictions of SERS EFs in the case of large non-spherical particles, where the lightning-rod effect (shape effect) and radiation damping (size effect) operate simultaneously. Finally, the localization effect at large SERS EF (hot-spots) is shown to be dictated only by shape, not size, in the case of metallic spheroids at the dipolar localized surface plasmon resonance.

  1. Designing of a novel gold nanodumbbells SERS substrate for detection of prohibited colorants in drinks

    Science.gov (United States)

    Meng, Juan; Qin, Suhua; Zhang, Li; Yang, Liangbao

    2016-03-01

    It is reported that the use of gold nanodumbbells as surface-enhanced Raman spectroscopy (SERS) substrates for the detection of ultra-low levels of four different food colorants: sunset yellow, lemon yellow, orange II and chrysoidin. Gold nanodumbbells are suitable to on-site detection because which have a λmax of 785 nm that tune the surface plasmon resonance of the nanoparticles to the laser excitation wavelength of the Raman spectrometer equipped with a 785 nm diode laser. In order to investigate the on-site application of the gold nanodumbbells substrate, four pigments in the orange juice and coke were detected by the portable Raman instrument. The results showed that this novel SERS platform can be used as an effective method in detecting prohibited additive colorants in food. This SERS platform provides valuable and powerful analytical tool in real-world applications in food analysis.

  2. Synthesis by picosecond laser ablation of ligand-free Ag and Au nanoparticles for SERS applications

    Science.gov (United States)

    Fazio, Enza; Spadaro, Salvatore; Santoro, Marco; Trusso, Sebastiano; Lucotti, Andrea.; Tommasini, Matteo.; Neri, Fortunato; Maria Ossi, Paolo

    2018-01-01

    The morphological and optical properties of noble metal nanoparticles prepared by picosecond laser generated plasmas in water were investigated. First, the ablation efficiency was maximized searching the optimal focusing conditions. The nanoparticle size, measured by Scanning Transmission Electron Microscopy, strongly depends on the laser fluence, keeping fixed the other deposition parameters such as the target to scanner objective distance and laser repetition frequency. STEM images indicate narrow gradients of NP sizes. Hence the optimization of ablation parameters favours a fine tuning of nanoparticles. UV-Visible spectroscopy helped to determine the appropriate laser wavelength to resonantly excite the localized surface plasmon to carry out Surface Enhanced Raman Scattering (SERS) measurements. The SERS activity of Ag and Au substrates, obtained spraying the colloids synthesized in water, was tested using crystal violet as a probe molecule. The good SERS performance, observed at excitation wavelength 785 nm, is attributed to aggregation phenomena of nanoparticles sprayed on the support.

  3. Tatuajes y su eliminación por láser

    Directory of Open Access Journals (Sweden)

    T. Castro

    Full Text Available La eliminación de los tatuajes con buen resultado cosmético ha sido una inquietud mantenida durante siglos. La introducción del tratamiento láser ha supuesto un avance importante de cara a obtener buenos resultados con mínimos efectos secundarios. En este trabajo se exponen los diferentes tipos de tatuajes con sus características de pigmento, origen, tipos de tratamientos para su eliminación, y entre ellos, la utilización de la tecnología láser, más concretamente de los láseres de emisión en Q-Switch con sus ventajas y limitaciones. Presentamos también los avances y el futuro de la aplicación del láser en el tratamiento de los tatuajes.

  4. Synthesis of Dendritic Silver Nanoparticles and Their Applications as SERS Substrates

    Directory of Open Access Journals (Sweden)

    Jinshan Yu

    2013-01-01

    Full Text Available The silver nanoparticles are synthesized by electrodeposition in ultradilute Ag+ concentration electrolyte under high overpotential. The as prepared Ag nanoparticles, with the sizes ranging from 20 to 30 nm, are arrayed orderly and formed dendritic morphology. The formation of this special dendritic nanoparticle structure can be contributed to the relatively high growth rate and the preferential growth directions along 111 due to the high overpotential, as well as the relative small number of Ag+ ions arriving at the Ag crystal surface per unit time due to the ultradilute Ag+ concentration. Surface enhanced Raman scattering (SERS experiments reveal that the as-prepared dendritic Ag nanoparticles possess high SERS properties and can be used as a candidate substrate for practical SERS applications to detect the Rhodamine 6G molecules.

  5. Quaternized chitosan/silver nanoparticles composite as a SERS substrate for detecting tricyclazole and Sudan I

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Kaihang; Shen, Zuguang [State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Luo, Jiwen, E-mail: holdit@126.com [State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Wang, Xiaoying, E-mail: xyw@scut.edu.cn [State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Sun, Runcang [State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Institute of Biomass Chemistry and Technology, Beijing Forestry University, Beijing 100083 (China)

    2015-10-01

    Graphical abstract: - Highlights: • Synthesis optimization of Ag NPs with quaternized chitosan (QCS) was studied. • The size of Ag NPs was tuned by changing the DS and Mw of QCS. • QCS/Ag NPs exhibited much better SERS performance than Ag NPs without free QCS. • QCS/Ag NPs as SERS substrate detected tricyclazole in low concentration of 50 ppb. • QCS/Ag NPs as SERS substrate detected Sudan I with the detection limit of 10 ppm. - Abstract: There is an urgent need to develop a highly sensitive detection system for detecting trace amounts of food contaminants. In this study, optimal synthesis of silver nanoparticles (Ag NPs) with stable and narrow size distribution in the range of 15–25 nm was performed under microwave irradiation, using quaternized chitosan (QCS) as reducing and stabilizing agent. The results showed that the ratio of QCS to [Ag(NH{sub 3}){sub 2}]{sup +}, reaction temperature, irradiation time, the degree of substitution (DS) and molecular weight (Mw) of QCS had obvious effects on the formation, particle size and size distribution of Ag NPs. In addition, utilizing QCS/Ag NPs composite as SERS substrate, tricyclazole and Sudan I could be rapidly and sensitively detected with the limit of detection (LOD) as low as 50 ppb and 10 ppm, respectively. Compared with previously reported works, our detection system are of great stability and operability. The QCS was coated on the surface of Ag core, avoiding aggregation of Ag NPs and creating hot spots, in turn, providing superior amplification of SERS. Thus, it is believed that the QCS/Ag NPs composite could be considered as an ideal SERS-active substrate for detection of food contaminants.

  6. Development of nanostars as a biocompatible tumor contrast agent: toward in vivo SERS imaging

    Directory of Open Access Journals (Sweden)

    D’Hollander A

    2016-08-01

    Full Text Available Antoine D’Hollander,1–3 Evelien Mathieu,1,4 Hilde Jans,1 Greetje Vande Velde,2,3 Tim Stakenborg,1 Pol Van Dorpe,1,4 Uwe Himmelreich,2,3 Liesbet Lagae1,4 1Department of Life Science Technology, Imec, 2Department of Imaging and Pathology, Faculty of Medicine, Biomedical MRI Unit, 3Faculty of Medicine, Molecular Small Animal Imaging Center (MoSAIC, 4Department of Physics, Faculty of Sciences, Laboratory of Solid State Physics and Magnetism, KU Leuven, Leuven, Belgium Abstract: The need for sensitive imaging techniques to detect tumor cells is an important issue in cancer diagnosis and therapy. Surface-enhanced Raman scattering (SERS, realized by chemisorption of compounds suitable for Raman spectroscopy onto gold nanoparticles, is a new method for detecting a tumor. As a proof of concept, we studied the use of biocompatible gold nanostars as sensitive SERS contrast agents targeting an ovarian cancer cell line (SKOV3. Due to a high intracellular uptake of gold nanostars after 6 hours of exposure, they could be detected and located with SERS. Using these nanostars for passive targeting after systemic injection in a xenograft mouse model, a detectable signal was measured in the tumor and liver in vivo. These signals were confirmed by ex vivo SERS measurements and darkfield microscopy. In this study, we established SERS nanostars as a highly sensitive contrast agent for tumor detection, which opens the potential for their use as a theranostic agent against cancer. Keywords: SERS, gold nanostars, cancer imaging, Raman active

  7. Paper membrane-based SERS platform for the determination of glucose in blood samples.

    Science.gov (United States)

    Torul, Hilal; Çiftçi, Hakan; Çetin, Demet; Suludere, Zekiye; Boyacı, Ismail Hakkı; Tamer, Uğur

    2015-11-01

    In this report, we present a paper membrane-based surface-enhanced Raman scattering (SERS) platform for the determination of blood glucose level using a nitrocellulose membrane as substrate paper, and the microfluidic channel was simply constructed by wax-printing method. The rod-shaped gold nanorod particles were modified with 4-mercaptophenylboronic acid (4-MBA) and 1-decanethiol (1-DT) molecules and used as embedded SERS probe for paper-based microfluidics. The SERS measurement area was simply constructed by dropping gold nanoparticles on nitrocellulose membrane, and the blood sample was dropped on the membrane hydrophilic channel. While the blood cells and proteins were held on nitrocellulose membrane, glucose molecules were moved through the channel toward the SERS measurement area. Scanning electron microscopy (SEM) was used to confirm the effective separation of blood matrix, and total analysis is completed in 5 min. In SERS measurements, the intensity of the band at 1070 cm(-1) which is attributed to B-OH vibration decreased depending on the rise in glucose concentration in the blood sample. The glucose concentration was found to be 5.43 ± 0.51 mM in the reference blood sample by using a calibration equation, and the certified value for glucose was 6.17 ± 0.11 mM. The recovery of the glucose in the reference blood sample was about 88 %. According to these results, the developed paper-based microfluidic SERS platform has been found to be suitable for use for the detection of glucose in blood samples without any pretreatment procedure. We believe that paper-based microfluidic systems may provide a wide field of usage for paper-based applications.

  8. El láser CO2 y sus aplicaciones en oftalmología veterinaria

    OpenAIRE

    Torrubia, I.

    2012-01-01

    El LASER (Light Amplification by Stimulated Emision of Radiation) es una fuente de energía descubierta a finales de los años 50 que se emplea en multitud de campos y que ha evolucionado constantemente desde entonces, obteniéndose multitud de tipos de láser en función de la longitud de onda con la que se trabaje. Este gran avance no puede dejar de tener sus aplicaciones en la medicina. Este artículo hace una referencia básica sobre los diferentes tipos de láser y sus características, tratando ...

  9. Surface-Enhanced Raman Scattering (SERS) for Detection in Immunoassays: applications, fundamentals, and optimization

    International Nuclear Information System (INIS)

    Jeremy Daniel Driskell

    2006-01-01

    Immunoassays have been utilized for the detection of biological analytes for several decades. Many formats and detection strategies have been explored, each having unique advantages and disadvantages. More recently, surface-enhanced Raman scattering (SERS) has been introduced as a readout method for immunoassays, and has shown great potential to meet many key analytical figures of merit. This technology is in its infancy and this dissertation explores the diversity of this method as well as the mechanism responsible for surface enhancement. Approaches to reduce assay times are also investigated. Implementing the knowledge gained from these studies will lead to a more sensitive immunoassay requiring less time than its predecessors. This dissertation is organized into six sections. The first section includes a literature review of the previous work that led to this dissertation. A general overview of the different approaches to immunoassays is given, outlining the strengths and weaknesses of each. Included is a detailed review of binding kinetics, which is central for decreasing assay times. Next, the theoretical underpinnings of SERS is reviewed at its current level of understanding. Past work has argued that surface plasmon resonance (SPR) of the enhancing substrate influences the SERS signal; therefore, the SPR of the extrinsic Raman labels (ERLs) utilized in our SERS-based immunoassay is discussed. Four original research chapters follow the Introduction, each presented as separate manuscripts. Chapter 2 modifies a SERS-based immunoassay previously developed in our group, extending it to the low-level detection of viral pathogens and demonstrating its versatility in terms of analyte type, Chapter 3 investigates the influence of ERL size, material composition, and separation distance between the ERLs and capture substrate on the SERS signal. This chapter links SPR with SERS enhancement factors and is consistent with many of the results from theoretical treatments

  10. Gold nanoparticles decorated liposomes and their SERS performance in tumor cells

    Science.gov (United States)

    Zhu, D.; Wang, Z. Y.; Zong, S. F.; Chen, H.; Chen, P.; Li, M. Y.; Wu, L.; Cui, Y. P.

    2015-05-01

    Due to their unique properties, liposomes have been widely used as drug nanocarriers. Herein a liposome-Au nanohybrid has been demonstrated as a SERS active intracellular drug nanocarrier. In this study, cationic Raman reporter tagged gold nanoparticles (Au@4MBA@PAH) were anchored onto the surfaces of anionic liposomes via electrostatic interactions. Using SKBR3 cells as model cells, we revealed that the hybrid formulation can be effectively taken up by tumor cells and tracked by the SERS signals. Collectively, the liposome-Au nanohybrids hold great promise in biomedical applications.

  11. Aplicaciones del láser Doppler en odontología

    OpenAIRE

    Pérez-García, Sílvia; Paredes García, Jordi; Berini Aytés, Leonardo; Gay Escoda, Cosme

    2002-01-01

    El flujómetro de láser Doppler es un método no invasivo que proporciona una medida continua del registro del flujo sanguíneo a nivel microvascular. Un haz de luz láser incidente en cualquier tejido humano, es dispersado tanto en las estructuras estáticas como por los glóbulos rojos. Los haces devueltos por los glóbulos rojos sufren una desviación en su frecuencia de acuerdo con el efecto Doppler, mientras que los dispersos por el tejido estático permanecen inalterados. Ambas fracciones de luz...

  12. Negación del ser para el reconocimiento del otro

    OpenAIRE

    Higuera Aguirre, Édison Francisco

    2014-01-01

    El presente trabajo propone la negación del ser como punto de partida para el reconocimiento del Otro. En su desarrollo el autor define qué es Ontología y resume su historia; explica la ambigüedad y equivocidad que los vocablos ser y Ontología tienen en la actualidad; denuncia la incompatibilidad de las respuestas de la Ontología tradicional ante el cambio de paradigmas; sostiene que una “Ontología” de la educación debe realizar una reflexión sobre los actos educativos concretos, ...

  13. Sistema láser de eliminación de Varroa

    OpenAIRE

    López Pérez, Ángel M.

    2016-01-01

    Descripción y diseño de un sistema de reconocimiento y destrucción por láser de los parásitos de las abejas melíferas. Descripció i disseny d'un sistema de reconeixement i destrucció per làser dels paràsits de les abelles mel·líferes. This work describes the design of a device for capturing stereoscopic images, through a system of computer vision. The vision system gives an analysis and monitoring of images and is able to recognize some parasites of the honey bees "apis mellifera", once...

  14. SERS analysis of Ag nanostructures produced by ion-beam deposition

    Science.gov (United States)

    Atanasov, P. A.; Nedyalkov, N. N.; Nikov, Ru G.; Grüner, Ch; Rauschenbach, B.; Fukata, N.

    2018-03-01

    This study deals with the development of a novel technique for formation of advanced Ag nanostructures (NSs) to be applied to high-resolution analyses based on surface enhanced Raman scattering (SERS). It has direct bearing on human health and food quality, e.g., monitoring small amount or traces of pollutants or undesirable additives. Three types of nanostructured Ag samples were produced using ion-beam deposition at glancing angle (GLAD) on quartz. All fabricated structures were covered with BI-58 pesticide (dimethoate) or Rhodamine 6G (R6G) for testing their potential for use as substrates for (SERS).

  15. Influence of the OGG1 Ser326Cys polymorphism on oxidatively damaged DNA and repair activity

    DEFF Research Database (Denmark)

    Jensen, Annie; Løhr, Mille; Eriksen, Louise

    2012-01-01

    Oxidatively damaged DNA base lesions are considered to be mainly repaired by 8-oxoguanine DNA glycosylase (OGG1) mediated pathways. We investigated the effect of the OGG1 Ser326Cys polymorphism on the level and repair of oxidatively damaged DNA in mononuclear blood cells (MNBC) by means of the co......Oxidatively damaged DNA base lesions are considered to be mainly repaired by 8-oxoguanine DNA glycosylase (OGG1) mediated pathways. We investigated the effect of the OGG1 Ser326Cys polymorphism on the level and repair of oxidatively damaged DNA in mononuclear blood cells (MNBC) by means...

  16. Ser educador(a é ... (também socializar inquietações

    Directory of Open Access Journals (Sweden)

    Sandra Marisa Allebrandt-Padilha

    2011-11-01

    Full Text Available O presente artigo convida os educadores a refletir sobre questões candentes do cotidiano escolar, tais como: o sofrimento diante do aluno que não aprende, o mal-estar-docente decorrente das transformações sociopolíticas que convergem para a Educação Inclusiva. Nessa perspectiva, com o propósito de buscar respostas para a Educação na Diversidade, elegemos algumas iniciativas que desafiam aqueles que desejam ser protagonistas no ofício SER EDUCADOR.Palavras-chave: Cotidiano Escolar. Dificuldade de Aprendizagem. Educação Inclusiva, Mal-Estar-Docente. Diversidade..

  17. O ser alcoolista: estudo compreensivo à luz da anÃlise existencial.

    OpenAIRE

    Ivando Amancio da Silva Junior

    2012-01-01

    O problema do alcoolismo à evidenciado nos efeitos desta droga que, alÃm de causar complicaÃÃes sociais, podem produzir consequÃncias orgÃnicas, mentais e espirituais. Os problemas advindos do uso abusivo de Ãlcool podem produzir vÃrios efeitos facilmente observÃveis no cotidiano das pessoas. Objetivando compreender o ser alcoolista, buscamos respaldo teÃrico na AnÃlise Existencial por estar atrelada aos preceitos compreensivo fenomenolÃgicos e ter a preocupaÃÃo com o significado do ser. O lo...

  18. Towards quantitative SERS detection of hydrogen cyanide at ppb level for human breath analysis

    DEFF Research Database (Denmark)

    Lauridsen, Rikke Kragh; Rindzevicius, Tomas; Molin, Søren

    2015-01-01

    ) at ppb level has been reported to be a PA biomarker. For early PA detection in CF children not yet chronically lung infected a non-invasive Surface-Enhanced Raman Spectroscopy (SERS)-based breath nanosensor is being developed. The triple bond between C and N in cyanide, with its characteristic band......). Lower KCN concentrations of 10 and 100 nM (corresponding to 0.18 and 1.8 ppb) produced SERS intensities that were relatively similar to the reference signal. Since HCN concentration in the breath of PA colonized CF children is reported to be ∼13.5 ppb, the detection of cyanide is within the required...

  19. Surface-Enhanced Raman Scattering (SERS) for Detection in Immunoassays. Applications, fundamentals, and optimization

    Energy Technology Data Exchange (ETDEWEB)

    Driskell, Jeremy Daniel [Iowa State Univ., Ames, IA (United States)

    2006-08-09

    Immunoassays have been utilized for the detection of biological analytes for several decades. Many formats and detection strategies have been explored, each having unique advantages and disadvantages. More recently, surface-enhanced Raman scattering (SERS) has been introduced as a readout method for immunoassays, and has shown great potential to meet many key analytical figures of merit. This technology is in its infancy and this dissertation explores the diversity of this method as well as the mechanism responsible for surface enhancement. Approaches to reduce assay times are also investigated. Implementing the knowledge gained from these studies will lead to a more sensitive immunoassay requiring less time than its predecessors. This dissertation is organized into six sections. The first section includes a literature review of the previous work that led to this dissertation. A general overview of the different approaches to immunoassays is given, outlining the strengths and weaknesses of each. Included is a detailed review of binding kinetics, which is central for decreasing assay times. Next, the theoretical underpinnings of SERS is reviewed at its current level of understanding. Past work has argued that surface plasmon resonance (SPR) of the enhancing substrate influences the SERS signal; therefore, the SPR of the extrinsic Raman labels (ERLs) utilized in our SERS-based immunoassay is discussed. Four original research chapters follow the Introduction, each presented as separate manuscripts. Chapter 2 modifies a SERS-based immunoassay previously developed in our group, extending it to the low-level detection of viral pathogens and demonstrating its versatility in terms of analyte type, Chapter 3 investigates the influence of ERL size, material composition, and separation distance between the ERLs and capture substrate on the SERS signal. This chapter links SPR with SERS enhancement factors and is consistent with many of the results from theoretical treatments

  20. Being elderly with functional dependence and their family caregivers Ser anciano con incapacidad y sus cuidadores familiares Ser idoso com incapacidade e seus cuidadores familiares

    Directory of Open Access Journals (Sweden)

    Amanda Maria Souza de Oliveira

    2012-01-01

    Full Text Available OBJECTIVE: To identify the authors` point of discussion on the elderly with functional dependence, correlating it with the ontological time discussed in Heidegger. METHODS: This is a bibliographic, systematic and qualitative study. Data was collected in the Scientific Electronic Library Online database. A total of 123 studies were identified, 15 studies were included considering the inclusion criteria. RESULTS: Based on the semantic analysis of Bardin, the following categories of analysis were established: being caregiver for the elderly with functional dependence, being elderly with functional dependence, family dynamics. CONCLUSION: It was understood that factors related to the worldliness of these people as family relationships, support of formal and informal services, economic and social situation, among others, are part of the history of these people influencing their modes of being. Searching to understand these factors is important to promote the health of these people, thinking of the biological and existential care.OBJETIVO: Identificar el punto de discusión de los autores sobre el anciano con incapacidad funcional, correlacionando con el tiempo ontológico heideggeriano. MÉTODOS: Estudio de tipo bibliográfico, sistemático y cualitativo. Los datos fueron recolectados en el banco de datos del Scientific Electronic Library Online. De un total de 123 publicaciones identificadas, fueron seleccionados 15 estudios, de acuerdo a los criterios de inclusión adoptados. RESULTADOS: Con base en el análisis temático de Bardin, fueron constituídas las siguientes categorías de análisis: ser-cuidador del anciano con incapacidad, ser-anciano con incapacidad, dinámica familiar. CONCLUSIÓN: Se comprendió que los factores relacionados a a relación familiar, apoyo de los servicios formales e informales, situación económica, social, entre otras, forman parte de la historicidad de éstas influenciando su modo de ser. Es importante buscar la

  1. SERS-active Ag Nanostars Substrates for Sensitive Detection of Ethyl Carbamate in Wine.

    Science.gov (United States)

    Li, Manli; Zhao, Yuan; Cui, Malin; Wang, Chan; Song, Qijun

    2016-01-01

    A simple and sensitive surface-enhanced Raman scattering (SERS) method for the detection of ethyl carbamate (EC) is reported in this work. Star-shaped silver nanostars (Ag NSs) were used as a novel SERS substrate. In comparison to other plasmonic nanoparticles (NPs), including Au NPs, Au NSs and Ag NPs, Ag NSs exhibit best SERS activity. Raman signal of EC at a trace level can be enhanced by several orders of magnitude with the help of Ag NSs. The Raman intensity of EC increased linearly with an increase of the EC concentration in the range from 5 × 10(-9) mol L(-1) to 1.0 × 10(-4) mol L(-1) with detection limit (LOD) of 1.37 × 10(-9) mol L(-1) (S/N = 3). The developed SERS approach also has the advantages of being simple, fast and requiring less amount of the sample. It could serve as a useful technology for the rapid determination of EC in both alcoholic beverages and fermented food.

  2. SERS detection of uranyl using functionalized gold nanostars promoted by nanoparticle shape and size.

    Science.gov (United States)

    Lu, Grace; Forbes, Tori Z; Haes, Amanda J

    2016-08-15

    The radius of curvature of gold (Au) nanostar tips but not the overall particle dimensions can be used for understanding the large and quantitative surface-enhanced Raman scattering (SERS) signal of the uranyl (UO2)(2+) moiety. The engineered roughness of the Au nanostar architecture and the distance between the gold surface and uranyl cations are promoted using carboxylic acid terminated alkanethiols containing 2, 5, and 10 methylene groups. By systematically varying the self-assembled monolayer (SAM) thickness with these molecules, the localized surface plasmon resonance (LSPR) spectral properties are used to quantify the SAM layer thickness and to promote uranyl coordination to the Au nanostars in neutral aqueous solutions. Successful uranyl detection is demonstrated for all three functionalized Au nanostar samples as indicated by enhanced signals and red-shifts in the symmetric U(vi)-O stretch. Quantitative uranyl detection is achieved by evaluating the integrated area of these bands in the uranyl fingerprint window. By varying the concentration of uranyl, similar free energies of adsorption are observed for the three carboxylic acid terminated functionalized Au nanostar samples indicating similar coordination to uranyl, but the SERS signals scale inversely with the alkanethiol layer thickness. This distance dependence follows previously established models assuming that roughness features associated with the radius of curvature of the tips are considered. These results indicate that SERS signals using functionalized Au nanostar substrates can provide quantitative detection of small molecules and that the tip architecture plays an important role in understanding the resulting SERS intensities.

  3. SERS Detection of Penicillin G Using Magnetite Decorated with Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Paula C. Pinheiro

    2017-10-01

    Full Text Available Sensitive and reliable procedures for detecting vestigial antibiotics are of great relevance for water quality monitoring due to the occurrence of such emergent pollutants in the aquatic environment. As such, we describe here research concerning the use of multifunctional nanomaterials combining magnetic and plasmonic components. These nanomaterials have been prepared by decorating magnetite nanoparticles (MNP with colloidal gold nanoparticles (Au NPs of distinct particle size distributions. Several analytical conditions were investigated in order to optimize the surface enhanced Raman scattering (SERS detection of penicillin G (PG dissolved in water. In particular, the dependence of the SERS signal by using distinct sized Au NPs adsorbed at the MNP was investigated. Additionally, microscopic methods, including Raman confocal microscopy, were employed to characterize the SERS substrates and then to qualitatively detect penicillin G using such substrates. For example, magnetic–plasmonic nanocomposites can be employed for magnetically concentrate analyte molecules and their removal from solution. As a proof of concept, we applied magneto-plasmonic nanosorbents in the removal of aqueous penicillin G and demonstrate the possibility of SERS sensing this antibiotic.

  4. Baroja o la conciencia de que el novelista debe ser un artesano

    Directory of Open Access Journals (Sweden)

    Jaime Espinosa Dederle

    1979-04-01

    Full Text Available No se puede volver la mirada a la España romántica, sin detenernos con obstinada curiosidad en la novelística de Pío Baroja. Su obra, como en rigor toda gran obra literaria, sólo con la perspectiva del tiempo puede ser evaluada con alguna justeza y meditación.

  5. Structure-dependent SERS activity of plasmonic nanorattles with built-in electromagnetic hotspots.

    Science.gov (United States)

    Liu, Keng-Ku; Tadepalli, Sirimuvva; Wang, Zheyu; Jiang, Qisheng; Singamaneni, Srikanth

    2017-11-20

    Hollow plasmonic nanostructures with built-in and accessible electromagnetic hotspots such as nanorattles, obtained through a galvanic replacement reaction, have received wide attention in chemical and biological sensing and targeted drug delivery. In this study, we investigate the surface enhanced Raman scattering (SERS) activity of plasmonic nanorattles obtained through different degrees of galvanic replacement of Au@Ag nanocubes. We found that the SERS efficacy of the nanorattles is governed by the plasmon extinction intensity, localized surface plasmon resonance (LSPR) wavelength of the nanostructures with respect to the excitation source and intensity of the electromagnetic field at the hotspot, with the latter playing a determining role. Finite-difference time-domain (FDTD) simulations showed excellent agreement with the experimental findings that an optimal degree of galvanic replacement is critical for maximum SERS enhancement. The rational design and synthesis of the plasmonic nanorattles based on these findings can make these nanostructures highly attractive for SERS-based chemical and biological sensing and bioimaging.

  6. Derivatization reaction-based surface-enhanced Raman scattering (SERS) for detection of trace acetone.

    Science.gov (United States)

    Zheng, Ying; Chen, Zhuo; Zheng, Chengbin; Lee, Yong-Ill; Hou, Xiandeng; Wu, Li; Tian, Yunfei

    2016-08-01

    A facile method was developed for determination of trace volatile acetone by coupling a derivatization reaction to surface-enhanced Raman scattering (SERS). With iodide modified Ag nanoparticles (Ag IMNPs) as the SERS substrate, acetone without obvious Raman signal could be converted to SERS-sensitive species via a chemical derivatization reaction with 2,4-dinitrophenylhydrazine (2,4-DNPH). In addition, acetone can be effectively separated from liquid phase with a purge-sampling device and then any serious interference from sample matrices can be significantly reduced. The optimal conditions for the derivatization reaction and the SERS analysis were investigated in detail, and the selectivity and reproducibility of this method were also evaluated. Under the optimal conditions, the limit of detection (LOD) for acetone was 5mgL(-1) or 0.09mM (3σ). The relative standard deviation (RSD) for 80mgL(-1) acetone (n=9) was 1.7%. This method was successfully used for the determination of acetone in artificial urine and human urine samples with spiked recoveries ranging from 92% to 110%. The present method is convenient, sensitive, selective, reliable and suitable for analysis of trace acetone, and it could have a promising clinical application in early diabetes diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. DNA detection and single nucleotide mutation identification using SERS for molecular diagnostics and global health

    Science.gov (United States)

    Ngo, Hoan T.; Gandra, Naveen; Fales, Andrew M.; Taylor, Steve M.; Vo-Dinh, Tuan

    2017-02-01

    Nucleic acid-based molecular diagnostics at the point-of-care (POC) and in resource-limited settings is still a challenge. We present a sensitive yet simple DNA detection method with single nucleotide polymorphism (SNP) identification capability. The detection scheme involves sandwich hybridization of magnetic beads conjugated with capture probes, target sequences, and ultrabright surface-enhanced Raman Scattering (SERS) nanorattles conjugated with reporter probes. Upon hybridization, the sandwich probes are concentrated at the detection focus controlled by a magnetic system for SERS measurements. The ultrabright SERS nanorattles, consisting of a core and a shell with resonance Raman reporters loaded in the gap space between the core and the shell, serve as SERS tags for ultrasensitive signal detection. Specific DNA sequences of the malaria parasite Plasmodium falciparum and dengue virus 1 (DENV1) were used as the model marker system. Detection limit of approximately 100 attomoles was achieved. Single nucleotide polymorphism (SNP) discrimination of wild type malaria DNA and mutant malaria DNA, which confers resistance to artemisinin drugs, was also demonstrated. The results demonstrate the molecular diagnostic potential of the nanorattle-based method to both detect and genotype infectious pathogens. The method's simplicity makes it a suitable candidate for molecular diagnosis at the POC and in resource-limited settings.

  8. Hierarchical Nanogaps within Bioscaffold Arrays as a High-Performance SERS Substrate for Animal Virus Biosensing

    NARCIS (Netherlands)

    Shao, Feng; Lu, Zhicheng; Liu, Chen; Han, Heyou; Chen, Kun; Li, Wentao; He, Qigai; Peng, Hui; Chen, Juanni

    2014-01-01

    A three-dimensional (3D) biomimetic SERS substrate with hierarchical nanogaps was formed on the bioscaffold arrays of cicada wings by one-step and reagents-free ion-sputtering techniques. This approach requires a minimal fabrication effort and cost and offers Ag nanoislands and Ag nanoflowers with

  9. Metal Nanoparticles Deposited on Porous Silicon Templates as Novel Substrates for SERS

    Directory of Open Access Journals (Sweden)

    Lara Mikac

    2015-12-01

    Full Text Available In this paper, results on preparation of stable and uniform SERS solid substrates using macroporous silicon (pSi with deposited silver and gold are presented. Macroporous silicon is produced by anodisation of p-type silicon in hydrofluoric acid. The as prepared pSi is then used as a template for Ag and Au depositions. The noble metals were deposited in three different ways: by immersion in silver nitrate solution, by drop-casting silver colloidal solution and by pulsed laser ablation (PLA. Substrates obtained by different deposition processes were evaluated for SERS efficiency using methylene blue (MB and rhodamine 6G (R6G at 514.5, 633 and 785 nm. Using 514.5 nm excitation and R6G the limits of detection (LOD for macroporous Si samples with noble metal nanostructures obtained by immersion of pSi sample in silver nitrate solution and by applying silver colloidal solution to pSi template were 10–9 M and 10–8 M respectively. Using 633 nm laser and MB the most noticeable SERS activity gave pSi samples ablated with 30000 and 45000 laser pulses where the LODs of 10–10 M were obtained. The detection limit of 10–10 M was also reached for 4 mA cm–2-15 min pSi sample, silver ablated with 30000 pulses. Macroporous silicon proved to be a good base for the preparation of SERS substrates.

  10. O HOMEM QUE QUERIA SER REI: Uma Aventura Maçônica

    OpenAIRE

    Freitas Neto, Edgard da Costa

    2014-01-01

    O presente trabalho busca demonstrar a influência da filosofia e do simbolismo maçônico presentesno conto “O homem que queria ser Rei”, de Rudyard Kipling, ressaltando as lições maçônicas que sepodem extrair daquela obra.

  11. Nonequilibrium Chemical Effects in Single-Molecule SERS Revealed by Ab Initio Molecular Dynamics Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Sean A.; Apra, Edoardo; Govind, Niranjan; Hess, Wayne P.; El-Khoury, Patrick Z.

    2017-02-03

    Recent developments in nanophotonics have paved the way for achieving significant advances in the realm of single molecule chemical detection, imaging, and dynamics. In particular, surface-enhanced Raman scattering (SERS) is a powerful analytical technique that is now routinely used to identify the chemical identity of single molecules. Understanding how nanoscale physical and chemical processes affect single molecule SERS spectra and selection rules is a challenging task, and is still actively debated. Herein, we explore underappreciated chemical phenomena in ultrasensitive SERS. We observe a fluctuating excited electronic state manifold, governed by the conformational dynamics of a molecule (4,4’-dimercaptostilbene, DMS) interacting with a metallic cluster (Ag20). This affects our simulated single molecule SERS spectra; the time trajectories of a molecule interacting with its unique local environment dictates the relative intensities of the observable Raman-active vibrational states. Ab initio molecular dynamics of a model Ag20-DMS system are used to illustrate both concepts in light of recent experimental results.

  12. SERS Substrates by the Assembly of Silver Nano cubes: High-Throughput and Enhancement Reliability Considerations

    International Nuclear Information System (INIS)

    Rabin, O.; Lee, S.Y.; Rabin, O.

    2012-01-01

    Small clusters of nanoparticles are ideal substrates for SERS measurements, but the SERS signal enhancement by a particular cluster is strongly dependent on its structural characteristics and the measurement conditions. Two methods for high-throughput assembly of silver nano cubes into small clusters at predetermined locations on a substrate are presented. These fabrication techniques make it possible to study both the structure and the plasmonic properties of hundreds of nanoparticle clusters. The variations in SERS enhancement factors from cluster to cluster were analyzed and correlated with cluster size and configuration, and laser frequency and polarization. Using Raman instruments with 633 nm and 785 nm lasers and linear clusters of nano cubes, an increase in the reproducibility of the enhancement and an increase in the average enhancement values were achieved by increasing the number of nano cubes in the cluster, up to 4 nano cubes per cluster. By examining the effect of cluster configuration, it is shown that linear clusters with nano cubes attached in a face-to-face configuration are not as effective SERS substrates as linear clusters in which nano cubes are attached along an edge

  13. Detection of Water Binding to the Oxygen Evolving Complex Using Low Frequency Sers

    Science.gov (United States)

    Wilson, Andrew J.; Jain, Prashant

    2017-06-01

    The oxygen evolving complex (OEC) in Photosystem II (PSII) is a hallmark catalyst for efficiently splitting water to generate molecular oxygen. Much of what is known about the structure of the OEC has been provided by X-ray analysis of PSII at low temperatures, from which the mechanism of water splitting has been inferred. Surface-enhanced Raman scattering (SERS) offers an opportunity to build on our current understanding of this catalytic system as it can provide time-resolved, molecular vibrational information in a physiological environment. With low frequency SERS, we are able to separate the manganese oxide vibrational modes of the OEC from those in a complex, biological environment. With isotopically labelled water, we use SERS to identify water binding to the OEC. Raman spectra calculated by density functional theory support the assignment of water binding to a manganese atom outside of the cuboidal OEC. Detection of water binding sites on the OEC with SERS can not only compliment previous structural studies, but can also provide a powerful platform for in operando mechanistic studies.

  14. Quantification of a bacterial secondary metabolite by SERS combined with SLM extraction for bioprocess monitoring

    DEFF Research Database (Denmark)

    Morelli, Lidia; Andreasen, Sune Zoëga; Jendresen, Christian Bille

    2017-01-01

    and combined it with surface enhanced Raman scattering (SERS) sensing for the screening of a biological process, namely for the quantification of a bacterial secondary metabolite, p-coumaric acid (pHCA), produced by Escherichia coli. The microfluidic device proved to be robust and reusable, enabling efficient....... The obtained data showed good correlation with HPLC analysis....

  15. Site-Specific Ser/Thr/Tyr Phosphoproteome of Sinorhizobium meliloti at Stationary Phase.

    Directory of Open Access Journals (Sweden)

    Tao Liu

    Full Text Available Sinorhizobium meliloti, a facultative microsymbiont of alfalfa, should fine-tune its cellular processes to live saprophytically in soils characterized with limited nutrients and diverse stresses. In this study, TiO2 enrichment and LC-MS/MS were used to uncover the site-specific Ser/Thr/Tyr phosphoproteome of S. meliloti in minimum medium at stationary phase. There are a total of 96 unique phosphorylated sites, with a Ser/Thr/Tyr distribution of 63:28:5, in 77 proteins. Phosphoproteins identified in S. meliloti showed a wide distribution pattern regarding to functional categories, such as replication, transcription, translation, posttranslational modification, transport and metabolism of amino acids, carbohydrate, inorganic ion, succinoglycan etc. Ser/Thr/Tyr phosphosites identified within the conserved motif in proteins of key cellular function indicate a crucial role of phosphorylation in modulating cellular physiology. Moreover, phosphorylation in proteins involved in processes related to rhizobial adaptation was also discussed, such as those identified in SMa0114 and PhaP2 (polyhydroxybutyrate synthesis, ActR (pH stress and microaerobic adaption, SupA (potassium stress, chaperonin GroEL2 (viability and potentially symbiosis, and ExoP (succinoglycan synthesis and secretion. These Ser/Thr/Tyr phosphosites identified herein would be helpful for our further investigation and understanding of the role of phosphorylation in rhizobial physiology.

  16. Phosphorylation of rat aquaporin-4 at Ser(111) is not required for channel gating

    DEFF Research Database (Denmark)

    Assentoft, Mette; Kaptan, Shreyas; Fenton, Robert A.

    2013-01-01

    is therefore of therapeutic interest. Phosphorylation of some aquaporins has been proposed to regulate their water permeability via gating of the channel itself. Protein kinase (PK)-dependent phosphorylation of Ser(111) has been reported to increase the water permeability of AQP4 expressed in an astrocytic...

  17. Cloning and expression of a portion of Bombyx Mori Ser/2 gene

    OpenAIRE

    STAŠKOVÁ, Tereza

    2009-01-01

    A 897 bp section of Bombyx mori Ser-2 gene was amplified, cloned into a bacterial expression vector, and used to prepare a recombinant sericin-like protein. The protein is expected to contain domain supporting growth of mammalian cells. It will be used in assays verifying this assumption; if confirmed, recombinant protein will be considered for preparations of scaffold guiding tissue reconstruction.

  18. Rapid detection of salmonella using SERS with silver nano-substrate

    Science.gov (United States)

    Sundaram, J.; Park, B.; Hinton, A., Jr.; Windham, W. R.; Yoon, S. C.; Lawrence, K. C.

    2011-06-01

    Surface Enhanced Raman Scattering (SERS) can detect the pathogen in rapid and accurate. In SERS weak Raman scattering signals are enhanced by many orders of magnitude. In this study silver metal with biopolymer was used. Silver encapsulated biopolymer polyvinyl alcohol nano-colloid was prepared and deposited on stainless steel plate. This was used as metal substrate for SERS. Salmonella typhimurium a common food pathogen was selected for this study. Salmonella typhimurium bacteria cells were prepared in different concentrations in cfu/mL. Small amount of these cells were loaded on the metal substrate individually, scanned and spectra were recorded using confocal Raman microscope. The cells were exposed to laser diode at 785 nm excitation and object 50x was used to focus the laser light on the sample. Raman shifts were obtained from 400 to 2400 cm-1. Multivariate data analysis was carried to predict the concentration of unknown sample using its spectra. Concentration prediction gave an R2 of 0.93 and standard error of prediction of 0.21. The results showed that it could be possible to find out the Salmonella cells present in a low concentration in food samples using SERS.

  19. O ser humano da sociedade capitalista na concepção de Erich Fromm

    Directory of Open Access Journals (Sweden)

    Edmilson Ferreira Marques

    2010-07-01

    Full Text Available

    A proposta deste texto é buscar na psicanálise pensada e desenvolvida por Erich Fromm elementos para se pensar o ser humano da sociedade capitalista. Erich Fromm, dentre a maioria dos psicanalistas existentes, desde Freud, procurou desenvolver suas pesquisas e reflexões a partir da “psicanálise humanista”, oferecendo, assim, recursos heurísticos fundamentais para se pensar a vida na sociedade. Nesse sentido, propomos analisar primeiramente o seu método de análise, a partir do qual acreditamos ser fundamental para compreender o procedimento teórico/metodológico que utilizava para pensar os temas por ele abordados, e, nesse sentido, encontrar o caminho a ser percorrido na busca em seu pensamento da seguinte questão: como abordar a partir de seu ponto de vista, o ser humano da sociedade capitalista? Enfim, propomos uma avaliação da própria teoria de Fromm, apontando suas principais contribuições.

  20. Raman and SERS recognition of β-carotene and haemoglobin fingerprints in human whole blood.

    Science.gov (United States)

    Casella, Michele; Lucotti, Andrea; Tommasini, Matteo; Bedoni, Marzia; Forvi, Elena; Gramatica, Furio; Zerbi, Giuseppe

    2011-09-01

    The present work reports on Raman and Surface Enhanced Raman Scattering (SERS) vibrational fingerprints of β-carotene and haemoglobin in fresh whole blood (i.e. right after blood test) with different laser excitations, i.e. visible (514 nm) and near-infrared (NIR, 785 nm). The use of colloidal silver nanoparticles significantly increases the Raman signal, thus providing a clear SERS spectrum of blood. The collected spectra have been examined and marker bands of β-carotene and of the haem prosthetic group of haemoglobin have been found. In particular, the fundamental features of β-carotene (514 nm excitation), blood proteins and haem molecules (785 nm excitation) were recognized and assigned. Moreover haemoglobin SERS signals can be identified and related with its oxygenation state (oxy-haemoglobin). The data reported show the prospects of Raman and SERS techniques to detect important bio-molecules in a whole blood sample with no pre-treatment. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Fabrication of SERS Active Surface on Polyimide Sample by Excimer Laser Irradiation

    Directory of Open Access Journals (Sweden)

    T. Csizmadia

    2014-01-01

    Full Text Available A possible application of excimer laser irradiation for the preparation of surface enhanced Raman spectroscopy (SERS substrate is demonstrated. A polyimide foil of 125 μm thickness was irradiated by 240 pulses of focused ArF excimer laser beam (λ = 193 nm, FWHM = 20 ns. The applied fluence was varied between 40 and 80 mJ/cm2. After laser processing, the sample was coated with 40 nm silver by PLD in order to create a conducting layer required for the SERS application. The SERS activity of the samples was tested by Raman microscopy. The Raman spectra of Rhodamine 6G aqueous solution (c=10−3 mol/dm3 were collected from the patterned and metalized areas. For areas prepared at 40–60 mJ/cm2 laser fluences, the measured Raman intensities have shown a linear dependence on the applied laser fluence, while above 60 mJ/cm2 saturation was observed. The morphology of the SERS active surface areas was investigated by scanning electron microscopy. Finite element modeling was performed in order to simulate the laser-absorption induced heating of the polyimide foil. The simulation resulted in the temporal and spatial distribution of the estimated temperature in the irradiated polyimide sample, which are important for understanding the structure formation process.

  2. A SERS-based lateral flow assay biosensor for highly sensitive detection of HIV-1 DNA.

    Science.gov (United States)

    Fu, Xiuli; Cheng, Ziyi; Yu, Jimin; Choo, Priscilla; Chen, Lingxin; Choo, Jaebum

    2016-04-15

    User-friendly lateral flow (LF) strips have been extensively used for point-of-care (POC) self-diagnostics, but they have some limitations in their detection sensitivity and quantitative analysis because they only identify the high cut-off value of a biomarker by utilizing color changes that are detected with the naked eye. To resolve these problems associated with LF strips, we developed a novel surface-enhanced Raman scattering (SERS)-based LF assay for the quantitative analysis of a specific biomarker in the low concentration range. Herein, human immunodeficiency virus type 1 (HIV-1) DNA was chosen as the specific biomarker. Raman reporter-labeled gold nanoparticles (AuNPs) were employed as SERS nano tags for targeting and detecting the HIV-1 DNA marker, as opposed to using bare AuNPs in LF strips. It was possible to quantitatively analyze HIV-1 DNA with high sensitivity by monitoring the characteristic Raman peak intensity of the DNA-conjugated AuNPs. Under optimized conditions, the detection limit of our SERS-based lateral flow assay was 0.24 pg/mL, which was at least 1000 times more sensitive compared to colorimetric or fluorescent detection methods. These results demonstrate the potential feasibility of the proposed SERS-based lateral flow assay to quantitatively detect a broad range of genetic diseases with high sensitivity. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Complete urinary tract infection (UTI) diagnosis and antibiogram using surface enhanced Raman spectroscopy (SERS)

    Science.gov (United States)

    Hadjigeorgiou, Katerina; Kastanos, Evdokia; Kyriakides, Alexandros; Pitris, Costas

    2012-03-01

    There are three stages to a complete UTI diagnosis: (1) identification of a urine sample as positive/negative for an infection, (2) identification of the responsible bacterium, (3) antibiogram to determine the antibiotic to which the bacteria are most sensitive to. Using conventional methods, all three stages require bacterial cultures in order to provide results. This long delay in diagnosis causes a rise in ineffective treatments, chronic infections, health care costs and antibiotic resistance. In this work, SERS is used to identify a sample as positive/negative for a UTI as well as to obtain an antibiogram against different antibiotics. SERS spectra of serial dilutions of E. coli bacteria mixed with silver nanoparticles, showed a linear correlation between spectral intensity and concentration. For antibiotic sensitivity testing, SERS spectra of three species of gram negative bacteria were collected four hours after exposure to the antibiotics ciprofloxacin and amoxicillin. Spectral analysis revealed clear separation between bacterial samples exposed to antibiotics to which they were sensitive and samples exposed to antibiotics to which they were resistant. With the enhancement provided by SERS, the technique can be applied directly to urine samples leading to the development of a new, rapid method for UTI diagnosis and antibiogram.

  4. Phosphoproteome analysis of E-coli reveals evolutionary conservation of bacterial Ser/Thr/Tyr phosphorylation

    DEFF Research Database (Denmark)

    Macek, B.; Gnad, F.; Soufi, Boumediene

    2008-01-01

    Protein phosphorylation on serine, threonine, and tyrosine (Ser/Thr/Tyr) is generally considered the major regulatory posttranslational modification in eukaryotic cells. Increasing evidence at the genome and proteome level shows that this modification is also present and functional in prokaryotes...

  5. An association between apo-A4 gene polymorphism (Thr347Ser ...

    African Journals Online (AJOL)

    Pramod Kumar

    Background: Coronary artery disease (CAD) is emerging as a major health problem in India. .... nary artery disease. Objectives were (I) To study the frequency distribution of apoA4 Thr347Ser, Gln360His genotype and alleles in healthy individuals (control) and patients with CAD; (II) To ..... Atherosclerosis: the road ahead.

  6. Nano graphene oxide-wrapped gold nanostars as ultrasensitive and stable SERS nanoprobes

    Science.gov (United States)

    Jalani, Ghulam; Cerruti, Marta

    2015-05-01

    We report a facile method to synthesize highly branched gold nanostars wrapped with nano graphene oxide (nGO) sheets with or without the addition of Raman dyes, as nanoprobes with high SERS activity. Both cysteamine and nGO are added to gold nanostars; the positively charged amino groups help self-assembly of nGO flakes around the nanostars. This increases the Raman signal of nGO by 5.3 folds compared to samples in which nGO is in contact with the nanostars but does not wrap them. We also prepare dye-based SERS nanoprobes by sandwiching a typical Raman reporter such as Rhodamine B (RhB), Crystal Violet (CV) and Rhodamine 6G (R6G) between the nanostars and the nGO coating. The Raman signals of RhB are 5.2 times larger when sandwiched between nGO and nanostars than if the molecules are just adsorbed on the nanostar surface, and similar enhancements are observed for the other dyes. In addition to improving SERS efficiency, the wrapping greatly improves the stability of the dye-based nanoprobes, showing a reproducible Raman signal of RhB for over a week in simulated body fluids at 37 °C. High SERS signal, facile fabrication method and excellent stability make these nanoprobes highly promising for SERS-based biosensing and bioimaging applications.We report a facile method to synthesize highly branched gold nanostars wrapped with nano graphene oxide (nGO) sheets with or without the addition of Raman dyes, as nanoprobes with high SERS activity. Both cysteamine and nGO are added to gold nanostars; the positively charged amino groups help self-assembly of nGO flakes around the nanostars. This increases the Raman signal of nGO by 5.3 folds compared to samples in which nGO is in contact with the nanostars but does not wrap them. We also prepare dye-based SERS nanoprobes by sandwiching a typical Raman reporter such as Rhodamine B (RhB), Crystal Violet (CV) and Rhodamine 6G (R6G) between the nanostars and the nGO coating. The Raman signals of RhB are 5.2 times larger when

  7. Improved size-tunable synthesis and SERS properties of Au nanostars

    Science.gov (United States)

    Khlebtsov, Boris; Panfilova, Elizaveta; Khanadeev, Vitaly; Khlebtsov, Nikolai

    2014-10-01

    Multibranched Au nanoparticles with sharp tips (commonly called nanostars, NSTs) have attracted significant attention as bright scattering labels, photothermal transducers, nanocarriers, and surface-enhanced Raman scattering (SERS) tags. However, for surfactant-free synthesized NSTs, the existing data on the size tuning and the relation between the size of NSTs and their SERS efficiency still remain limited. Here, we address these questions by synthesizing and comparing SERS for surfactant-free NSTs of different sizes and plasmon resonance (PR) wavelengths. The NSTs were fabricated by seeded growth through a two-step surfactant-free approach in which quasispherical seeds were overgrown via reduction of added Au by ascorbic acid in the presence of Ag ions. By varying the seed size from 3 to 35 nm, we tuned the final NST size from 45 to 150 nm while retaining the star-like morphology with sharp tips and ensuring PR tunability from 630 to 900 nm. The NST size and PR limits can be expanded from 40 to 200 nm and from 600 to 930 nm, respectively, by simultaneous variation in the seed size and concentration. The SERS efficiency of the fabricated NSTs was examined by Raman measurements of 1,4-aminothiophenol (ATP) adsorbed on the surface of colloidal NST particles. Although the homogenous analytical enhancement factor (AEF) did not depend essentially on the NST size and varied from 4 × 106 to 107, the enhancing properties of single-particle NST tags were strongly size-dependent. Specifically, the AEF for 150-nm NST35-ATP complexes was 30 and 100 times greater than that for 70-nm NST15-ATP and 45-nm NST3-ATP complexes, respectively. These properties make the NST-ATP complex a prospective platform for SERS imaging.

  8. Controlled graphene oxide assembly on silver nanocube monolayers for SERS detection: dependence on nanocube packing procedure

    Directory of Open Access Journals (Sweden)

    Martina Banchelli

    2016-01-01

    Full Text Available Hybrid graphene oxide/silver nanocubes (GO/AgNCs arrays for surface-enhanced Raman spectroscopy (SERS applications were prepared by means of two procedures differing for the method used in the assembly of the silver nanocubes onto the surface: Langmuir–Blodgett (LB transfer and direct sequential physisorption of silver nanocubes (AgNCs. Adsorption of graphene oxide (GO flakes on the AgNC assemblies obtained with both procedures was monitored by quartz crystal microbalance (QCM technique as a function of GO bulk concentration. The experiment provided values of the adsorbed GO mass on the AgNC array and the GO saturation limit as well as the thickness and the viscoelastic properties of the GO film. Atomic force microscopy (AFM measurements of the resulting samples revealed that a similar surface coverage was achieved with both procedures but with a different distribution of silver nanoparticles. In the GO covered LB film, the AgNC distribution is characterized by densely packed regions alternating with empty surface areas. On the other hand, AgNCs are more homogeneously dispersed over the entire sensor surface when the nanocubes spontaneously adsorb from solution. In this case, the assembly results in less-packed silver nanostructures with higher inter-cube distance. For the two assembled substrates, AFM of silver nanocubes layers fully covered with GO revealed the presence of a homogeneous, flexible and smooth GO sheet folding over the silver nanocubes and extending onto the bare surface. Preliminary SERS experiments on adenine showed a higher SERS enhancement factor for GO on Langmuir–Blodgett films of AgNCs with respect to bare AgNC systems. Conversely, poor SERS enhancement for adenine resulted for GO-covered AgNCs obtained by spontaneous adsorption. This indicated that the assembly and packing of AgNCs obtained in this way, although more homogeneous over the substrate surface, is not as effective for SERS analysis.

  9. Surface enhanced Raman scattering (SERS) with biopolymer encapsulated silver nanosubstrates for rapid detection of foodborne pathogens.

    Science.gov (United States)

    Sundaram, Jaya; Park, Bosoon; Kwon, Yongkuk; Lawrence, Kurt C

    2013-10-01

    A biopolymer encapsulated with silver nanoparticles was prepared using silver nitrate, polyvinyl alcohol (PVA) solution, and trisodium citrate. It was deposited on a mica sheet to use as SERS substrate. Fresh cultures of Salmonella Typhimurium, Escherichia coli, Staphylococcus aureus and Listeria innocua were washed from chicken rinse and suspended in 10 ml of sterile deionized water. Approximately 5 μl of the bacterial suspensions was placed on the substrate individually and exposed to 785 nm HeNe laser excitation. SERS spectral data were recorded over the Raman shift between 400 and 1800 cm(-1) from 15 different spots on the substrate for each sample; and three replicates were done on each bacteria type. Principal component analysis (PCA) model was developed to classify foodborne bacteria types. PC1 identified 96% of the variation among the given bacteria specimen, and PC2 identified 3%, resulted in a total of 99% classification accuracy. Soft Independent Modeling of Class Analogies (SIMCA) of validation set gave an overall correct classification of 97%. Comparison of the SERS spectra of different types of gram-negative and gram-positive bacteria indicated that all of them have similar cell walls and cell membrane structures. Conversely, major differences were noted around the nucleic acid and amino acid structure information between 1200 cm(-1) and 1700 cm(-1) and at the finger print region between 400 cm(-1) and 700 cm(-1). Silver biopolymer nanoparticle substrate could be a promising SERS tool for pathogen detection. Also this study indicates that SERS technology could be used for reliable and rapid detection and classification of food borne pathogens. Published by Elsevier B.V.

  10. Label-free direct surface-enhanced Raman scattering (SERS) of nucleic acids (Conference Presentation)

    Science.gov (United States)

    Guerrini, Luca; Morla-Folch, Judit; Gisbert-Quilis, Patricia; Xie, Hainan; Alvarez-Puebla, Ramon

    2016-03-01

    Recently, plasmonic-based biosensing has experienced an unprecedented level of attention, with a particular focus on the nucleic acid detection, offering efficient solutions to engineer simple, fast, highly sensitive sensing platforms while overcoming important limitations of PCR and microarray techniques. In the broad field of plasmonics, surface-enhanced Raman scattering (SERS) spectroscopy has arisen as a powerful analytical tool for detection and structural characterization of biomolecules. Today applications of SERS to nucleic acid analysis largely rely on indirect strategies, which have been demonstrated very effective for pure sensing purposes but completely dismiss the exquisite structural information provided by the direct acquisition of the biomolecular vibrational fingerprint. Contrarily, direct label-free SERS of nucleic acid shows an outstanding potential in terms of chemical-specific information which, however, remained largely unexpressed mainly because of the inherent poor spectral reproducibility and/or limited sensitivity. To address these limitations, we developed a fast and affordable high-throughput screening direct SERS method for gaining detailed genomic information on nucleic acids (DNA and RNA) and for the characterization and quantitative recognition of DNA interactions with exogenous agents. The simple strategy relies on the electrostatic adhesion of DNA/RNA onto positively-charged silver colloids that promotes the nanoparticle aggregation into stable clusters yielding intense and reproducible SERS spectra at picogram level (i.e. the analysis can be performed without the necessity of amplification steps thus providing realistic direct information of the nucleic acid in its native state). We anticipate this method to gain a vast impact and set of applications in different fields, including medical diagnostics, genomic screening, drug discovery, forensic science and even molecular electronics.

  11. O cotidiano do ser-adolescendo com aids: movimento ou momento existencial?

    Directory of Open Access Journals (Sweden)

    Cristiane Cardoso de Paula

    Full Text Available As crianças com AIDS por transmissão vertical transitam da infância para adolescência, e pouco se sabe sobre como cuidam de si. Compreender este cotidiano do adolescer foi o objetivo desta investigação fenomenológica com análise hermenêutica heideggeriana. A entrevista com 11 meninos/meninas (12-14 anos não institucionalizados, que conheciam seu diagnóstico, ocorreu depois da aprovação do projeto pelo Comitê de Ética de três instituições do Rio de Janeiro, cenários da pesquisa. Os resultados apontaram um cotidiano marcado pelos momentos infância e adolescência. Às vezes quer voltar a ser-criança para brincar; se re-conhece como ser-adolescente pela aparência, humor, atividades diárias, lazer e relacionamentos. Transitando entre esses momentos, re-vela-se como ser-adolescendo. Neste movimento existencial des-vela-se como ser-de-possibilidades, que não está limitado à dupla-facticidade: adolescer (segundo demarcações etárias e características predeterminadas e AIDS (fragilidade clínica. Portanto, conjugar as dimensões biológica e existencial, no modelo assistencial-institucional, é o desafio do cuidado ao ser-adolescendo.

  12. The BARD1 Cys557Ser variant and breast cancer risk in Iceland.

    Directory of Open Access Journals (Sweden)

    Simon N Stacey

    2006-07-01

    Full Text Available Most, if not all, of the cellular functions of the BRCA1 protein are mediated through heterodimeric complexes composed of BRCA1 and a related protein, BARD1. Some breast-cancer-associated BRCA1 missense mutations disrupt the function of the BRCA1/BARD1 complex. It is therefore pertinent to determine whether variants of BARD1 confer susceptibility to breast cancer. Recently, a missense BARD1 variant, Cys557Ser, was reported to be at increased frequencies in breast cancer families. We investigated the role of the BARD1 Cys557Ser variant in a population-based cohort of 1,090 Icelandic patients with invasive breast cancer and 703 controls. We then used a computerized genealogy of the Icelandic population to study the relationships between the Cys557Ser variant and familial clustering of breast cancer.The Cys557Ser allele was present at a frequency of 0.028 in patients with invasive breast cancer and 0.016 in controls (odds ratio [OR] = 1.82, 95% confidence interval [CI] 1.11-3.01, p = 0.014. The alleleic frequency was 0.037 in a high-predisposition group of cases defined by having a family history of breast cancer, early onset of breast cancer, or multiple primary breast cancers (OR = 2.41, 95% CI 1.22-4.75, p = 0.015. Carriers of the common Icelandic BRCA2 999del5 mutation were found to have their risk of breast cancer further increased if they also carried the BARD1 variant: the frequency of the BARD1 variant allele was 0.047 (OR = 3.11, 95% CI 1.16-8.40, p = 0.046 in 999del5 carriers with breast cancer. This suggests that the lifetime probability of a BARD1 Cys557Ser/BRCA2 999del5 double carrier developing breast cancer could approach certainty. Cys557Ser carriers, with or without the BRCA2 mutation, had an increased risk of subsequent primary breast tumors after the first breast cancer diagnosis compared to non-carriers. Lobular and medullary breast carcinomas were overrepresented amongst Cys557Ser carriers. We found that an excess of ancestors

  13. Hierarchically assembled Au microspheres and sea urchin-like architectures: formation mechanism and SERS study

    Science.gov (United States)

    Wang, Xiansong; Yang, Da-Peng; Huang, Peng; Li, Min; Li, Chao; Chen, Di; Cui, Daxiang

    2012-11-01

    The hierarchically assembled Au microspheres/sea urchin-like structures have been synthesized in aqueous solution at room temperature with and without proteins (bovine serum albumin, BSA) as mediators. The average diameter of an individual Au microsphere is 300-600 nm, which is composed of some compact nanoparticles with an average diameter of about 15 nm. Meanwhile, the sea urchin-like Au architecture exhibits an average diameter of 600-800 nm, which is made up of some nanopricks with an average length of 100-200 nm. These products are characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electronic microscopy (TEM). It is found that the BSA and ascorbic acid (AA) have great effects on the morphology of the resulting products. Two different growth mechanisms are proposed. The study on surface enhanced Raman scattering (SERS) activities is also carried out between Au microspheres and Au sea urchin-like architectures. It is found that Au urchin-like architectures possess much higher SERS activity than the Au microspheres. Our work may shed light on the design and synthesis of hierarchically self-assembled 3D micro/nano-architectures for SERS, catalysis and biosensors.The hierarchically assembled Au microspheres/sea urchin-like structures have been synthesized in aqueous solution at room temperature with and without proteins (bovine serum albumin, BSA) as mediators. The average diameter of an individual Au microsphere is 300-600 nm, which is composed of some compact nanoparticles with an average diameter of about 15 nm. Meanwhile, the sea urchin-like Au architecture exhibits an average diameter of 600-800 nm, which is made up of some nanopricks with an average length of 100-200 nm. These products are characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electronic microscopy (TEM). It is found that the BSA and ascorbic acid (AA) have great effects on the morphology of

  14. Use of Single-Layer g-C3N4/Ag Hybrids for Surface-Enhanced Raman Scattering (SERS)

    OpenAIRE

    Jiang, Jizhou; Zou, Jing; Wee, Andrew Thye Shen; Zhang, Wenjing

    2016-01-01

    Surface-enhanced Raman scattering (SERS) substrates with high activity and stability are desirable for SERS sensing. Here, we report a new single atomic layer graphitic-C3N4 (S-g-C3N4) and Ag nanoparticles (NPs) hybrid as high-performance SERS substrates. The SERS mechanism of the highly stable S-g-C3N4/Ag substrates was systematically investigated by a combination of experiments and theoretical calculations. From the results of XPS and Raman spectroscopies, it was found that there was a stro...

  15. 3D Fractals as SERS Active Platforms: Preparation and Evaluation for Gas Phase Detection of G-Nerve Agents

    Directory of Open Access Journals (Sweden)

    Marta Lafuente

    2018-01-01

    Full Text Available One of the main limitations of the technique surface-enhanced Raman scattering (SERS for chemical detection relies on the homogeneity, reproducibility and reusability of the substrates. In this work, SERS active platforms based on 3D-fractal microstructures is developed by combining corner lithography and anisotropic wet etching of silicon, to extend the SERS-active area into 3D, with electrostatically driven Au@citrate nanoparticles (NPs assembly, to ensure homogeneous coating of SERS active NPs over the entire microstructured platforms. Strong SERS intensities are achieved using 3D-fractal structures compared to 2D-planar structures; leading to SERS enhancement factors for R6G superior than those merely predicted by the enlarged area effect. The SERS performance of Au monolayer-over-mirror configuration is demonstrated for the label-free real-time gas phase detection of 1.2 ppmV of dimethyl methylphosphonate (DMMP, a common surrogate of G-nerve agents. Thanks to the hot spot accumulation on the corners and tips of the 3D-fractal microstructures, the main vibrational modes of DMMP are clearly identified underlying the spectral selectivity of the SERS technique. The Raman acquisition conditions for SERS detection in gas phase have to be carefully chosen to avoid photo-thermal effects on the irradiated area.

  16. Application of a SERS-based lateral flow immunoassay strip for the rapid and sensitive detection of staphylococcal enterotoxin B

    Science.gov (United States)

    Hwang, Joonki; Lee, Sangyeop; Choo, Jaebum

    2016-06-01

    A novel surface-enhanced Raman scattering (SERS)-based lateral flow immunoassay (LFA) biosensor was developed to resolve problems associated with conventional LFA strips (e.g., limits in quantitative analysis and low sensitivity). In our SERS-based biosensor, Raman reporter-labeled hollow gold nanospheres (HGNs) were used as SERS detection probes instead of gold nanoparticles. With the proposed SERS-based LFA strip, the presence of a target antigen can be identified through a colour change in the test zone. Furthermore, highly sensitive quantitative evaluation is possible by measuring SERS signals from the test zone. To verify the feasibility of the SERS-based LFA strip platform, an immunoassay of staphylococcal enterotoxin B (SEB) was performed as a model reaction. The limit of detection (LOD) for SEB, as determined with the SERS-based LFA strip, was estimated to be 0.001 ng mL-1. This value is approximately three orders of magnitude more sensitive than that achieved with the corresponding ELISA-based method. The proposed SERS-based LFA strip sensor shows significant potential for the rapid and sensitive detection of target markers in a simplified manner.A novel surface-enhanced Raman scattering (SERS)-based lateral flow immunoassay (LFA) biosensor was developed to resolve problems associated with conventional LFA strips (e.g., limits in quantitative analysis and low sensitivity). In our SERS-based biosensor, Raman reporter-labeled hollow gold nanospheres (HGNs) were used as SERS detection probes instead of gold nanoparticles. With the proposed SERS-based LFA strip, the presence of a target antigen can be identified through a colour change in the test zone. Furthermore, highly sensitive quantitative evaluation is possible by measuring SERS signals from the test zone. To verify the feasibility of the SERS-based LFA strip platform, an immunoassay of staphylococcal enterotoxin B (SEB) was performed as a model reaction. The limit of detection (LOD) for SEB, as

  17. Background information for the SER Energy Agreement for Sustainable Growth calculations. Sector Built Environment; Achtergronddocument bij doorrekening SER Energieakkoord. Sector Gebouwde omgeving

    Energy Technology Data Exchange (ETDEWEB)

    Menkveld, M.; Tigchelaar, C. [ECN Beleidsstudies, Petten (Netherlands)

    2013-09-01

    This publication is part of the support given by ECN and PBL in the development of a national energy agreement between March and September 2013 as initiated by the SER (Social and Economic Council of the Netherlands). The report gives background information on the evaluation of measures in the agreement aimed at the built environment. It is an annex of the general evaluation of PBL/ECN [Dutch] Dit rapport is geschreven als onderdeel van de ondersteuning door ECN en PBL bij het tot stand komen van het energieakkoord in de periode maart tot september 2013. Dit rapport dient als achtergrond bij de doorrekening van de maatregelen gericht op energiebesparing in de gebouwde omgeving.

  18. Ser ou não ser: os conflitos funcionais do profissional no contexto das escolas de ensino superior no Brasil

    Directory of Open Access Journals (Sweden)

    Jalmir Pinheiro de Souza Júnior

    2013-12-01

    Full Text Available http://dx.doi.org/10.5007/1983-4535.2013v6n4p49   As instituições de ensino superior brasileiras vêm passando por sucessivas mudanças desde a implementação da LDB, e consequente atuação do professor alicerçada na tríade ensino, pesquisa e extensão. Um processo de transformação em direção a conceber a universidade como empresa, orientada para as demandas do mercado, com cobranças por maior produtividade ganhou força. Este estudo qualitativo, interpretativista, visa ampliar a discussão dos impactos que este cenário tem causado nos docentes, e na realização da prática docente. Foram entrevistados nove docentes que se posicionaram por meio da exposição da experiência já vivenciada na sua atuação cotidiana. Os resultados, pós análise do discurso, evidenciaram a situação preocupante em que se encontra a classe de professores de ensino superior no Brasil, passando por frustrações e insatisfações, no campo profissional, que só fazem estimular o individualismo, aguçar a competitividade entre colegas, e a conseqüente queda na qualidade das relações estabelecidas entre alunos e professores. A desmotivação profissional tem se intensificado a cada período e é ilustrado pelo aumento dos conflitos e pela inquietação com a qual muitos já convivem, na dúvida iminente por ser ou não ser um professor universitário.

  19. Silver nanocluster films for glucose sensing by Surface Enhanced Raman Scattering (SERS

    Directory of Open Access Journals (Sweden)

    Raju Botta

    2016-07-01

    Full Text Available The detection of glucose by Surface Enhanced Raman Scattering (SERS is a challenging problem because glucose molecules have a small Raman scattering cross-section and they have a low affinity for adsorption on metal nanoparticle surfaces. In this study we used 2-Thienylboronic acid (2-TBA as a bridge or linker molecule between the metal surface and the glucose molecule and observed an intense Raman line at 986 cm−1 that was used to quantify the glucose concentration in the molar concentration range 1 μM–500 μM. A good correlation was observed between the intensity of this line and molar concentration of glucose. These results would find applications in the development of a non-invasive glucose sensor for diabetic patients using saliva as the body fluid instead of blood serum. Keywords: SERS, Nanoclusters, Raman Spectroscopy, 2-Thienylboronic acid, d-Glucose

  20. Copper nanowire coated carbon fibers as efficient substrates for detecting designer drugs using SERS.

    Science.gov (United States)

    Halouzka, Vladimir; Halouzkova, Barbora; Jirovsky, David; Hemzal, Dusan; Ondra, Peter; Siranidi, Eirini; Kontos, Athanassios G; Falaras, Polycarpos; Hrbac, Jan

    2017-04-01

    Miniature Surface Enhanced Raman Scattering (SERS) sensors were fabricated by coating the carbon fiber microelectrodes with copper nanowires. The coating procedure, based on anodizing the copper wire in ultrapure water followed by cathodic deposition of the anode-derived material onto carbon fiber electrodes, provides a "clean" copper nanowire network. The developed miniature (10µm in diameter and 2mm in length) and nanoscopically rough SERS substrates are applicable in drug sensing, as shown by the detection and resolving of a range of seized designer drugs in trace amounts (microliter volumes of 10 -10 -10 -12 M solutions). The copper nanowire modified carbon microfiber substrates could also find further applications in biomedical and environmental sensing. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Determining molecular orientation via single molecule SERS in a plasmonic nano-gap.

    Science.gov (United States)

    Marshall, Addison R L; Stokes, Jamie; Viscomi, Francesco N; Proctor, John E; Gierschner, Johannes; Bouillard, Jean-Sebastien G; Adawi, Ali M

    2017-11-16

    In this work, plasmonic nano-gaps consisting of a silver nanoparticle coupled to an extended silver film have been fully optimized for single molecule Surface-Enhanced Raman Scattering (SERS) spectroscopy. The SERS signal was found to be strongly dependent on the particle size and the molecule orientation with respect to the field inside the nano-gap. Using Finite Difference Time Domain (FDTD) simulations to complement the experimental measurements, the complex interplay between the excitation enhancement and the emission enhancement of the system as a function of particle size were highlighted. Additionally, in conjunction with Density Functional Theory (DFT), the well-defined field direction in the nano-gap enables to recover the orientation of individual molecules.

  2. Phospho-Ser/Thr-binding domains: navigating the cell cycle and DNA damage response.

    Science.gov (United States)

    Reinhardt, H Christian; Yaffe, Michael B

    2013-09-01

    Coordinated progression through the cell cycle is a complex challenge for eukaryotic cells. Following genotoxic stress, diverse molecular signals must be integrated to establish checkpoints specific for each cell cycle stage, allowing time for various types of DNA repair. Phospho-Ser/Thr-binding domains have emerged as crucial regulators of cell cycle progression and DNA damage signalling. Such domains include 14-3-3 proteins, WW domains, Polo-box domains (in PLK1), WD40 repeats (including those in the E3 ligase SCF(βTrCP)), BRCT domains (including those in BRCA1) and FHA domains (such as in CHK2 and MDC1). Progress has been made in our understanding of the motif (or motifs) that these phospho-Ser/Thr-binding domains connect with on their targets and how these interactions influence the cell cycle and DNA damage response.

  3. Heparin Assisted Photochemical Synthesis of Gold Nanoparticles and Their Performance as SERS Substrates

    Science.gov (United States)

    Rodríguez-Torres, Maria del Pilar; Díaz-Torres, Luis Armando; Romero-Servin, Sergio

    2014-01-01

    Reactive and pharmaceutical-grade heparins were used as biologically compatible reducing and stabilizing agents to photochemically synthesize colloidal gold nanoparticles. Aggregates and anisotropic shapes were obtained photochemically under UV black-light lamp irradiation (λ = 366 nm). Heparin-functionalized gold nanoparticles were characterized by Scanning Electron Microscopy and UV-Vis spectroscopy. The negatively charged colloids were used for the Surface Enhanced Raman Spectroscopy (SERS) analysis of differently charged analytes (dyes). Measurements of pH were taken to inspect how the acidity of the medium affects the colloid-analyte interaction. SERS spectra were taken by mixing the dyes and the colloidal solutions without further functionalization or addition of any aggregating agent. PMID:25342319

  4. Optical manipulation of plasmonic nanoparticles, bubble formation and patterning of SERS aggregates.

    Science.gov (United States)

    Liu, Zuwei; Hung, Wei Hsuan; Aykol, Mehmet; Valley, David; Cronin, Stephen B

    2010-03-12

    We present an optical method for patterning SERS (surface-enhanced Raman spectroscopy)--enhancing aggregates of gold nanoparticles, using a focused laser beam to optically trap the nanoparticles in suspension. At high laser powers, heat generated from the plasmonic excitation causes boiling of the aqueous suspension and the formation of gaseous bubbles of water vapor. By measuring the Raman peak of the hydroxyl bond of water, the temperature in the laser spot during the aggregation can be determined in situ. The hydrophilic nanoparticles are found to aggregate at the liquid-vapor interface. By allowing the suspension to dry, a ring of gold nanoparticles is deposited on the substrate, producing a highly SERS-active region. These aggregates are studied using optical microscopy, scanning electron microscopy and micro-Raman spectroscopy.

  5. pH sensing through a single optical fibre using SERS and CMOS SPAD line arrays.

    Science.gov (United States)

    Ehrlich, K; Kufcsák, A; McAughtrie, S; Fleming, H; Krstajic, N; Campbell, C J; Henderson, R K; Dhaliwal, K; Thomson, R R; Tanner, M G

    2017-12-11

    Full exploitation of fibre Raman probes has been limited by the obstruction of weak Raman signals by background fluorescence of the sample and the intrinsic Raman signal of the delivery fibre. Here we utilised functionalised gold nanoshells (NS) to take advantage of the surface-enhanced Raman spectroscopy (SERS) effect to enhance the pH responsive spectrum of 4-mercaptobenzoic acid (MBA). However, the fibre background is still dominant. Using the photon arrival time-resolving capability of a CMOS single-photon avalanche diode (SPAD) based line sensor, we recover the SERS spectrum without a fibre background in a 10 s measurement. In this manner, pH sensing through a multimode fibre at a low excitation power that is safe for future in vivo applications, with short acquisition times (10 or 60 s), is demonstrated. A measurement precision of ± 0.07 pH units is thus achieved.

  6. Caracterización de haces láser empleados en la industria

    OpenAIRE

    Ramos de Campos, Jose A.

    2012-01-01

    Los láseres tienen numerosas aplicaciones. En estas aplicaciones es necesario utilizar sistemas ópticos para guiar y a veces transformar el haz láser. Para un correcto diseño de estos sistemas ópticos es fundamental, además de un conocimiento de las propiedades de propagación de los haces láser, el empleo de técnicas de caracterización de los mismos. Existe una serie de cuestiones que todavía no han sido investigadas suficientemente y que no son fenómenos de excepción, sino que se present...

  7. Ag nanoparticles agargel nanocomposites for SERS detection of cultural heritage interest pigments

    Science.gov (United States)

    Amato, F.; Micciche', C.; Cannas, M.; Gelardi, F. M.; Pignataro, B.; Li Vigni, M.; Agnello, S.

    2018-02-01

    Agarose gel (agargel) composites with commercial and laboratory made silver nanoparticles were prepared by a wet solution method at room temperature. The gel composites were used for pigment extraction and detection by Raman spectroscopy. Red (alizarin) and violet (crystal violet) pigments deposited on paper were extracted by the composites and were investigated by micro-Raman spectroscopy. Evaluation was carried out of the surface-enhanced Raman spectroscopy (SERS) effect induced by the silver nanoparticles embedded in the gel. A kinetic approach as a function of time was used to determine the efficiency of pigments extraction by composites deposition. A non-invasive extraction process of few minutes is demonstrated. This process induces active SERS for both used pigments. The reported results show the full exploitability of agargel silver nanoparticle composites for the extraction of pigments from paper based artworks.

  8. Tornar-se uma outra na histeria e ser uma outra do falso self

    OpenAIRE

    Pinheiro, Teresa

    2004-01-01

    Este trabalho pretende fazer uma comparação entre a histeria e o falso self a partir do projeto de “ser uma outra” presente nas duas patologias. O projeto de “tornar-se uma outra” na histeria aponta para personagens que necessariamente estão presentes nesse modelo fantasmático: a vítima e o vilão. A noção de “ser uma outra”, no falso-self, apresenta-se como única forma possível de estar no mundo, onde a ilusão não tem lugar. Este trabajo pretende comparar la histeria con el falso-self a pa...

  9. Tornar-se uma outra na histeria e ser uma outra do falso self

    Directory of Open Access Journals (Sweden)

    Teresa Pinheiro

    Full Text Available Este trabalho pretende fazer uma comparação entre a histeria e o falso self a partir do projeto de “ser uma outra” presente nas duas patologias. O projeto de “tornar-se uma outra” na histeria aponta para personagens que necessariamente estão presentes nesse modelo fantasmático: a vítima e o vilão. A noção de “ser uma outra”, no falso-self, apresenta-se como única forma possível de estar no mundo, onde a ilusão não tem lugar.

  10. Controllable Charge Transfer in Ag-TiO₂ Composite Structure for SERS Application.

    Science.gov (United States)

    Wang, Yaxin; Yan, Chao; Chen, Lei; Zhang, Yongjun; Yang, Jinghai

    2017-06-28

    The nanocaps array of TiO₂/Ag bilayer with different Ag thicknesses and co-sputtering TiO₂-Ag monolayer with different TiO₂ contents were fabricated on a two-dimensional colloidal array substrate for the investigation of Surface enhanced Raman scattering (SERS) properties. For the TiO₂/Ag bilayer, when the Ag thickness increased, SERS intensity decreased. Meanwhile, a significant enhancement was observed when the sublayer Ag was 10 nm compared to the pure Ag monolayer, which was ascribed to the metal-semiconductor synergistic effect that electromagnetic mechanism (EM) provided by roughness surface and charge-transfer (CT) enhancement mechanism from TiO₂-Ag composite components. In comparison to the TiO₂/Ag bilayer, the co-sputtered TiO₂-Ag monolayer decreased the aggregation of Ag particles and led to the formation of small Ag particles, which showed that TiO₂ could effectively inhibit the aggregation and growth of Ag nanoparticles.

  11. Solution-dispersible Au nanocube dimers with greatly enhanced two-photon luminescence and SERS

    Science.gov (United States)

    Liu, Xiao-Li; Liang, Shan; Nan, Fan; Yang, Zhong-Jian; Yu, Xue-Feng; Zhou, Li; Hao, Zhong-Hua; Wang, Qu-Quan

    2013-05-01

    We report the synthesis of 43-nm diameter Au nanocube dimers by using Ag+ ions as competitive ligands to freeze l-cysteine-induced assembly process of the nanocubes to a desirable stage. Ascribed to the resonant interparticle coupling with an newly arising plasmon band at 710 nm and local field enhancement, the two-photon luminescence intensity of the Au nanocube dimers in solution was over 20 times stronger than that of the monomers in the wavelength range 555-620 nm. Furthermore, by coupling Raman tags onto the nanocube surface, a solution-based surface-enhanced Raman scattering (SERS) of the nanocube dimers had an enhancement factor of over 10 times compared to the isolated nanocubes. To sum up, with high stability in solution and attractive optical properties, the Au nanocube dimers have potential applications in in vivo bio-imaging and solution-based SERS.We report the synthesis of 43-nm diameter Au nanocube dimers by using Ag+ ions as competitive ligands to freeze l-cysteine-induced assembly process of the nanocubes to a desirable stage. Ascribed to the resonant interparticle coupling with an newly arising plasmon band at 710 nm and local field enhancement, the two-photon luminescence intensity of the Au nanocube dimers in solution was over 20 times stronger than that of the monomers in the wavelength range 555-620 nm. Furthermore, by coupling Raman tags onto the nanocube surface, a solution-based surface-enhanced Raman scattering (SERS) of the nanocube dimers had an enhancement factor of over 10 times compared to the isolated nanocubes. To sum up, with high stability in solution and attractive optical properties, the Au nanocube dimers have potential applications in in vivo bio-imaging and solution-based SERS. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr01170d

  12. Porous plasmonic nanocomposites for SERS substrates fabricated by two-step laser method

    Energy Technology Data Exchange (ETDEWEB)

    Koleva, M.E., E-mail: mihaela_ek@yahoo.com [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee blvd., Sofia 1784 (Bulgaria); International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 (Japan); Nedyalkov, N.N.; Atanasov, P.A. [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee blvd., Sofia 1784 (Bulgaria); Gerlach, J.W.; Hirsch, D.; Prager, A.; Rauschenbach, B. [Leibniz Institute of Surface Modification (IOM), Permoserstrasse 15, D-04318 Leipzig (Germany); Fukata, N.; Jevasuwan, W. [International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 (Japan)

    2016-04-25

    This research is focused on investigation of coupled plasmonic/metal-semiconductor nanomaterials. A two-step laser-assisted method is demonstrated for formation of plasmonic Ag nanoparticles (NPs) distributed into porous metal–oxide semiconductors. The mosaic Ag-ZnO target is used for laser ablation and, subsequently, laser annealing of the deposited layer is applied. The plasmon resonance properties of the nanostructures produced are confirmed by optical transmission spectroscopy. The wurtzite structure of ZnO is formed with tilted c-axis orientation and, respectively, a mixed Raman mode appears at 580 cm{sup −1}. The oxygen pressure applied during a deposition process has impact on the morphology and thickness of the porous nanostructures, but not on the size and size distribution of AgNPs. The porous nanocomposites exhibited potential for SERS applications, most pronounced for the oxygen deficient sample, grown at lower oxygen pressure. The observed considerable SERS enhancement of R6G molecules on AgNP/ZnO can be attributed to the ZnO-to-molecule charge transfer contribution, enhanced by the additional electrons from the local surface plasmon resonance (LSPR) of AgNPs to the ZnO through the conduction band. - Highlights: • Porous AgNPs/ZnO composites are obtained by laser deposition and laser annealing. • Morphology and properties depend on growth oxygen pressure. • The emergence of mixed-symmetry Raman mode at 580 cm{sup −1} is registered. • The AgNPs/ZnO porous nanocomposites are suitable for SERS-active substrates. • The charge transfer enhanced by LSPR has a contribution to SERS effect.

  13. Towards quantitative SERS detection of hydrogen cyanide at ppb level for human breath analysis

    Directory of Open Access Journals (Sweden)

    Rikke Kragh Lauridsen

    2015-09-01

    Full Text Available Lung infections with Pseudomonas aeruginosa (PA is the most common cause of morbidity and mortality in cystic fibrosis (CF patients. Due to its ready adaptation to the dehydrated mucosa of CF airways, PA infections tend to become chronic, eventually killing the patient. Hydrogen cyanide (HCN at ppb level has been reported to be a PA biomarker. For early PA detection in CF children not yet chronically lung infected a non-invasive Surface-Enhanced Raman Spectroscopy (SERS-based breath nanosensor is being developed. The triple bond between C and N in cyanide, with its characteristic band at ∼2133 cm−1, is an excellent case for the SERS-based detection due to the infrequent occurrence of triple bonds in nature. For demonstration of direct HCN detection in the gas phase, a gold-coated silicon nanopillar substrate was exposed to 5 ppm HCN in N2. Results showed that HCN adsorbed on the SERS substrate can be consistently detected under different experimental conditions and up to 9 days after exposure. For detection of lower cyanide concentrations serial dilution experiments using potassium cyanide (KCN demonstrated cyanide quantification down to 1 μM in solution (corresponding to 18 ppb. Lower KCN concentrations of 10 and 100 nM (corresponding to 0.18 and 1.8 ppb produced SERS intensities that were relatively similar to the reference signal. Since HCN concentration in the breath of PA colonized CF children is reported to be ∼13.5 ppb, the detection of cyanide is within the required range.

  14. Measurement of elongational viscosity of polymer melts using SER Universal Testing Platform

    Czech Academy of Sciences Publication Activity Database

    Filip, Petr; Švrčinová, Petra

    2012-01-01

    Roč. 22, č. 1 (2012), s. 14776 ISSN 1430-6395 R&D Projects: GA ČR GA103/08/1307; GA ČR GA103/09/2066 Institutional research plan: CEZ:AV0Z20600510 Keywords : elongational viscosity * SER Universal Testing Platform * polymer melts * LDPE Subject RIV: BK - Fluid Dynamics Impact factor: 1.226, year: 2012 http://www.ar.ethz.ch/TMPPDF/23074299892.48/ApplRheol_22_14776.pdf

  15. P-Ser-HPr-a link between carbon metabolism and the virulence of some pathogenic bacteria

    DEFF Research Database (Denmark)

    Mijakovic, Ivan

    2005-01-01

    HPr kinase/phosphorylase phosphorylates HPr, a phosphocarrier protein of the phosphoenolpyruvate:carbohydrate phosphotransferase system, at serine-46. P-Ser-HPr is the central regulator of carbon metabolism in Gram-positive bacteria, but also plays a role in virulence development of certain patho...... a role in pathogenesis. Indeed, inactivation of Neisseria meningitidis hprK strongly diminished cell adhesion of this pathogen....

  16. ID-SERS Based Reference Method for Quantification of Large Biomolecules on a Single Chip

    Science.gov (United States)

    Yaghobian, Fatemeh; Stosch, Rainer; Henrion, André; Güttler, Bernd

    2010-08-01

    Accuracy and precision of quantitative SERS results have been significantly increased by applying a method based on the so-called isotope-dilution (ID) principle. In this ID-SERS approach, an isotopically labeled analogue of the target molecule (isotopologue) is spiked to the sample at a known concentration. Due to the slight difference in their molar masses, some Raman bands of the heavier isotopologue are red-shifted with respect to the same signals resulting from the unlabelled compound. As a result, spectra evaluation is reduced to the determination of intensity ratios rather than absolute intensities, and the unknown quantity of the analyte can be calculated from the known quantity of the standard. This procedure is of particular interest in the development of highly accurate reference procedures for metrology in chemistry. Because the sample is spiked prior to any further treatment, potential loss of material or matrix effects would equally affect both isotopologues, without influencing the final result. The method has been successfully applied for quantifying small diagnostic marker molecules like creatinine at their relevant serum concentration levels using silver colloids as SERS substrates. Now, the ID-SERS approach has been realized as a "one-chip" approach using "Bio-chips" made of intrinsically grown spherical silver nanoparticles with gaps less than 10 nm in between (Fig. 1). In addition, the scope of the method has been extended to larger biomolecules like peptides which will be shown using the example of the human growth-hormone (hGH) peptide T12 at physiologically relevant serum concentration levels (Fig. 2). Further developments towards the quantification of full proteins will also be reported.

  17. NZ Ser: the results of the analysis of the 25 years photometric activity

    Science.gov (United States)

    Barsunova, O.; Mel'nikov, S.; Grinin, V.; Katysheva, N.; Shugarov, S.

    2014-03-01

    We present the analysis of the long-term photometric variability of NZ Ser. The object shows both large-scale cyclic variability and low-amplitude Algol-like, fading typical for UX Ori stars. The variations of the stellar brightness are accompanied by variations of the B-V and V-R colors: when the brightness decreases, B-V decreases, while V-R increases.

  18. SERS enhancement of silver nanoparticles prepared by a template-directed triazole ligand strategy.

    Science.gov (United States)

    Kashmery, Heba A; Thompson, David G; Dondi, Ruggero; Mabbott, Samuel; Graham, Duncan; Clark, Alasdair W; Burley, Glenn A

    2015-08-21

    Two advances in the development of a one-pot method to prepare silver nanoparticles (AgNPs) using the Tollens' reagent are described. First, a template-directed process of AgNP synthesis using resorcinol triazole ligands bearing two pendent galactose sugars is shown. Second, the conversion of these AgNPs into SERS nanotags is demonstrated using malachite green isothiocyanate as the Raman reporter molecule.

  19. A reagent-assisted method in SERS detection of methyl salicylate

    Science.gov (United States)

    Li, Yali; Li, Qianwen; Wang, Yanan; Oh, Joohee; Jin, Sila; Park, Yeonju; Zhou, Tieli; Zhao, Bing; Ruan, Weidong; Jung, Young Mee

    2018-04-01

    With the explosive application of methyl salicylate (MS) molecules in food and cosmetics, the further detection of MS molecules becomes particularly important. Here we investigated the detection of MS molecules based on surface-enhanced Raman scattering (SERS) in a novel molecule/assistant/metal system constructed with MS, 4,4‧-(hexafluoroisopropylidene) bis (benzoic acid) and Ag nanoparticles (AgNPs). The minimum detection concentration is 10-4 M. To explore the function of assisted reagent, we also referred another system without assistant molecules. The result demonstrates that SERS signals were not acquired, which proves that the assistant molecules are critical for the capture of MS molecules. Two possible mechanisms of MS/assistant/AgNPs system were speculated through two patterns of hydrogen bonds. The linker molecules acted as the role of the bridge between metallic substrates and target molecules through the molecular recognition. This strategy is very beneficial to the expanding of MS detection techniques and other hydrogen bond based coupling detections with SERS.

  20. Therapeutic drug monitoring of flucytosine in serum using a SERS-active membrane system

    Science.gov (United States)

    Berger, Adam G.; White, Ian M.

    2017-02-01

    A need exists for near real-time therapeutic drug monitoring (TDM), in particular for antibiotics and antifungals in patient samples at the point-of-care. To truly fit the point-of-care need, techniques must be rapid and easy to use. Here we report a membrane system utilizing inkjet-fabricated surface enhanced Raman spectroscopy (SERS) sensors that allows sensitive and specific analysis despite the elimination of sophisticated chromatography equipment, expensive analytical instruments, and other systems relegated to the central lab. We utilize inkjet-fabricated paper SERS sensors as substrates for 5FC detection; the use of paper-based SERS substrates leverages the natural wicking ability and filtering properties of microporous membranes. We investigate the use of microporous membranes in the vertical flow assay to allow separation of the flucytosine from whole blood. The passive vertical flow assay serves as a valuable method for physical separation of target analytes from complex biological matrices. This work further establishes a platform for easy, sensitive, and specific TDM of 5FC from whole blood.

  1. Chemiresistive/SERS dual sensor based on densely packed gold nanoparticles

    Directory of Open Access Journals (Sweden)

    Sanda Boca

    2015-12-01

    Full Text Available Chemiresistors are a class of sensitive electrical devices capable of detecting (biochemicals by simply monitoring electrical resistance. Sensing based on surface enhanced Raman scattering (SERS represents a radically different approach, in which molecules are optically detected according to their vibrational spectroscopic fingerprint. Despite different concepts are involved, one can find in the literature examples from both categories reporting sensors made of gold nanoparticles. The same building blocks appear because both sensor classes share a common principle: nanometric interparticle gaps are needed, for electron tunneling in chemiresistors, and for enhancing electromagnetic fields by plasmon coupling in SERS-based sensors. By exploiting such nano-gaps in self-assembled films of gold nanoparticles, we demonstrate the proof of concept of a dual electrical/optical sensor, with both chemiresistive and SERS capabilities. The proposed device is realized by self-assembling 15 nm gold nanoparticles into few micrometers-wide strips across commercially available interdigitated electrodes. The dual-mode operation of the device is demonstrated by the detection of a biologically relevant model analyte, 4-mercaptophenyl boronic acid.

  2. The effect of silver thickness on the enhancement of polymer based SERS substrates

    International Nuclear Information System (INIS)

    Schneidewind, H; Weber, K; Zeisberger, M; Hübner, U; Dellith, A; Cialla-May, D; Mattheis, R; Popp, J

    2014-01-01

    We investigated silver-covered polymer based nanogratings as substrates for surface-enhanced Raman spectroscopy (SERS), in particular with respect to the thickness of the plasmonically active silver film. In order to obtain accurate geometrical input data for the simulation process, we inspected cross sections of the gratings prepared by breaking at cryogenic temperature. We noticed a strong dependence of the simulation results on geometrical variations of the structures. Measurements revealed that an increasing silver film thickness on top of the nanogratings leads to a blue shift of the plasmonic resonance, as predicted by numerical simulations, as well as to an increased field enhancement for an excitation at 488 nm. We found a clear deviation of the experimental data compared to the simulated results for very thin silver films due to an island-like growth at a silver thickness below 20 nm. In order to investigate the SERS activity. we carried out measurements with crystal violet as a model analyte at an excitation wavelength of 488 nm. The SERS enhancement increases up to a silver thickness of about 30 nm, whereas it remains nearly constant for thicker silver films. (paper)

  3. Silver films over silica microspheres (AgFOSM) as SERS substrates

    Science.gov (United States)

    Flores-Romero, E.; Rodríguez-Sevilla, E.; Cheang-Wong, J. C.

    2018-02-01

    Through the years, nanosphere lithography (NSL) has attracted a growing interest because of its potential to manufacture a wide variety of homogeneous arrays of nanostructures. In this work, NSL was used for the fabrication of Surface-Enhanced Raman Spectroscopy (SERS) substrates. The proposed Raman-SERS substrates consist of 50 nm or 120 nm thick silver thin films evaporated over a monolayer of silica microspheres (AgFOSM) onto silicon or quartz substrates. The samples were tested as SERS substrates using Rhodamine 6G as analyte. As a comparison and to determine the Raman enhancement factor, not only the AgFOSM samples were measured, but also we studied similar samples obtained when the Ag film is directly deposited onto the silicon or quartz substrate. Our results show that the R6G Raman signal is always more intense by two or three orders of magnitude for the AgFOSM samples than for the Ag maskless ones. In the case of the 120 nm thick Ag films, the calculated enhancement factors for the AgFOSM samples are of the order of 104 for both silicon and quartz substrates.

  4. SENTIDOS DO SER-AÍ-MULHER-APÓS-CIRURGIA-CARDÍACA À LUZ DE HEIDEGGER

    Directory of Open Access Journals (Sweden)

    Thaís Vasconselos Amorim

    2013-01-01

    Full Text Available Estudio cualitativo con objetivo de presentar el descubrimiento de sentidos del ser-mujer-después-cirugía-cardíaca sostenidos por Heidegger. El escenario fue un hospital de alta complejidad cardiovascular en Minas Gerais, Brasil. La fase de campo se produjo en diciembre de 2011 y enero de 2012, y las entrevistadas fueron llevadas a cabo a partir de la pregunta: ¿Cómo es su día a día después de la cirugía? Las lecturas y escuchas de testimonios posibilitaron análisis y interpretación. La mujer aparece en la publicidad, dominada por impersonal, siendo en la charla, curiosidad y ambigüedad. Revela insuficiencia en temor mediado a través del miedo, horror y terror, en dirección a la de-cadencia. Ante los movimientos existenciales, se puede comprender que como ser-en el-mundo, la mujer se escondió en la disposición para el autocuidado, señalando hueco a ser llenado por el enfermero a través de la promoción de la salud que debe aplicarse en su práctica.

  5. SER Performance of Large Scale OFDM-SDMA Based Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Mostafa Hefnawi

    2014-01-01

    Full Text Available This paper proposes an adaptive large scale multiple input multiple output-beamforming scheme (LSMIMO-BF for uplink (UL access in broadband wireless cognitive networks with multiple primary users (PUs and secondary users (SUs sharing the same spectrum and employing orthogonal frequency-division multiplexing (OFDM. The proposed algorithm seeks the optimal transmit/receive weight vectors that maximize the UL MIMO channel capacity for each cognitive user while controlling the interference levels to PUs. Under the assumption of very large number of antennas at the base station, a closed-form expression for the symbol error rate (SER performance of the cognitive LSMIMO-OFDM system is derived and compared with the one based on conventional beamforming schemes such as MIMO-maximum ratio combining (MIMO-MRC. The analysis and simulation show that when SUs are transmitting with the proposed constrained capacity-aware (CCA scheme, the total interference level at the primary base station is reduced and the SER of PUs is improved compared to the case when the secondary network is using conventional MIMO-MRC. It was also shown that, as the number of base station antennas becomes larger, the constraints imposed by the primary network could be relaxed and the symbol error rate (SER of SUs is improved without harming the PUs performance.

  6. Determination of thiabendazole in orange juice using an MISPE-SERS chemosensor.

    Science.gov (United States)

    Feng, Jingyi; Hu, Yaxi; Grant, Edward; Lu, Xiaonan

    2018-01-15

    Thiabendazole, a systemic fungicide used to treat vegetables and fruits during postharvest process, persists as detrimental residue to consumers. We combine a molecularly imprinted polymers (MIPs) with surface enhanced Raman spectroscopy (SERS) to form a novel MISPE-SERS chemosensor and determined thiabendazole in orange juice. Kinetic and static adsorption tests validated the efficient and selective adsorption of thiabendazole using synthesized MIPs via precipitation polymerization. Synthesized MIPs were packed into solid phase extraction (SPE) cartridge to serve as tailor-made sorbents for the separation of thiabendazole in orange juice. Silver colloids synthesized by reduction of AgNO 3 by trisodium citrate were used as SERS-active substrate to quantify the eluted thiabendazole from MISPE. The overall process including sample preparation and detection took 23min and the limit of detection of this chemosensor was 4ppm for thiabendazole in orange juice. This chemosensor can be used for rapid and sensitive detection of thiabendazole in agri-foods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Alkaline phosphatase labeled SERS active sandwich immunoassay for detection of Escherichia coli

    Science.gov (United States)

    Bozkurt, Akif Goktug; Buyukgoz, Guluzar Gorkem; Soforoglu, Mehmet; Tamer, Ugur; Suludere, Zekiye; Boyaci, Ismail Hakki

    2018-04-01

    In this study, a sandwich immunoassay method utilizing enzymatic activity of alkaline phosphatase (ALP) on 5-bromo-4-chloro-3-indolyl phosphate (BCIP) for Escherichia coli (E. coli) detection was developed using surface enhanced Raman spectroscopy (SERS). For this purpose, spherical magnetic gold coated core-shell nanoparticles (MNPs-Au) and rod shape gold nanoparticles (Au-NRs) were synthesized and modified for immunomagnetic separation (IMS) of E. coli from the solution. In order to specify the developed method to ALP activity, Au-NRs were labeled with this enzyme. After successful construction of the immunoassay, BCIP substrate was added to produce the SERS-active product; 5-bromo-4-chloro-3-indole (BCI). A good linearity (R2 = 0.992) was established between the specific SERS intensity of BCI at 600 cm- 1 and logarithmic E. coli concentration in the range of 1.7 × 101-1.7 × 106 cfu mL- 1. LOD and LOQ values were also calculated and found to be 10 cfu mL- 1 and 30 cfu mL- 1, respectively.

  8. Hierarchically assembled Au microspheres and sea urchin-like architectures: formation mechanism and SERS study.

    Science.gov (United States)

    Wang, Xiansong; Yang, Da-Peng; Huang, Peng; Li, Min; Li, Chao; Chen, Di; Cui, Daxiang

    2012-12-21

    The hierarchically assembled Au microspheres/sea urchin-like structures have been synthesized in aqueous solution at room temperature with and without proteins (bovine serum albumin, BSA) as mediators. The average diameter of an individual Au microsphere is 300-600 nm, which is composed of some compact nanoparticles with an average diameter of about 15 nm. Meanwhile, the sea urchin-like Au architecture exhibits an average diameter of 600-800 nm, which is made up of some nanopricks with an average length of 100-200 nm. These products are characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electronic microscopy (TEM). It is found that the BSA and ascorbic acid (AA) have great effects on the morphology of the resulting products. Two different growth mechanisms are proposed. The study on surface enhanced Raman scattering (SERS) activities is also carried out between Au microspheres and Au sea urchin-like architectures. It is found that Au urchin-like architectures possess much higher SERS activity than the Au microspheres. Our work may shed light on the design and synthesis of hierarchically self-assembled 3D micro/nano-architectures for SERS, catalysis and biosensors.

  9. Study of optical and physicochemical properties of colloidal silver nanoparticles as an efficient substrate for SERS

    International Nuclear Information System (INIS)

    Cyrankiewicz, M; Kruszewski, S

    2011-01-01

    The unique optical and physicochemical properties of the noble metal colloidal nanoparticles enable their use in a wide range of applications, especially as a substrate in SERS and MEF study. The aim of this work is to characterize the conditions for the enhancement of Raman scattering by molecules adsorbed on silver surface. Silver sol is prepared by slightly modified Lee-Meisel's method and rhodamine 6G is used as a probe adsorbate. Pure colloidal silver suspension containing isolated nanoparticles exhibits relatively poor SERS efficiency. The extremely large electromagnetic field is induced in the junctions between two or more metallic nanocrystalites so some degree of their aggregation is necessary. The influence of potassium chloride and nitric acid as the aggregating agents is investigated here. The experiments show that both of them can promote the controlled aggregation process but chloride anions, unlike nitrate, much more effectively affect both electromagnetic and chemical mechanisms contributing to SERS. Due to the co-adsorption with rhodamine 6G they allow the dye molecules to directly interact with metallic surface. Moreover, the results clearly indicate that chloride in the presence of silver particles can induce the dimerization of the dye molecules.

  10. The application of Silver nanoparticle based SERS in diagnosing thyroid tissue

    Energy Technology Data Exchange (ETDEWEB)

    Huang Zufang; Chen Rong; Chen Guannan; Lin Duo; Xi Gangqin; Chen Yongjian; Lin Hongxin; Lei Jinping [Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, Fujian Normal University, Fuzhou 350007 (China); Li Zuanfang, E-mail: chenr@fjnu.edu.cn [Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou 350108 (China)

    2011-01-01

    Surface-enhanced Raman scattering (SERS) is proved to be a powerful analytical tool for investigation of biological tissue. In this study, SERS based on Ag nanoparticles was used to investigate the normal and cancerous thyroid tissue. Preliminary results indicated that Raman peaks and the spectra profile from both normal and cancerous tissues showed a basic similarity, obvious differences are that, first, Raman peaks 563cm{sup -1}, 1449cm{sup -1} and 1587cm{sup -1} in cancerous tissue decreased obviously compared with the normal thyroid tissue. Besides, Raman peaks 1004cm{sup -1} and 1128cm{sup -1} might be specific peaks for normal thyroid tissue, whereas 1294cm{sup -1} might attribute to specific peak for cancerous thyroid tissue. In addition, some peaks in normal thyroid tissue appeared to have shifted in cancerous tissue. Intensity ratio of 656cm{sup -1} vs. 725cm{sup -1} in normal tissue are significantly different from cancerous tissue (P<0.005), and it can be a reference for spectroscopic diagnostics of thyroid tissue. This study demonstrates that SERS can be used to monitor the changes at molecular level as well as a complementary tool in thyroid histopathology.

  11. Insights of adsorption mechanisms of Trp-peptides on plasmonic surfaces by SERS

    Science.gov (United States)

    daFonseca, Bruno Guilherme; Costa, Luiz Antônio Sodré; Sant'Ana, Antonio Carlos

    2018-02-01

    The adsorptions of tryptophan (Trp) on silver or gold surfaces were investigated by surface-enhanced Raman scattering (SERS) measurements. In addition, peptides with Trp in different chain positions were studied and the adsorption sites were determined based on marker bands. The indole ring was the main group responsible for the interactions with gold nanoparticles (AuNPs). In the presence of HCl, the SERS spectra suggested that the anchoring of such peptides on AuNPs was reinforced by ionic pair interactions between protonated amine and chloride ions. The adsorptions of Trp and its derivatives on silver nanoparticles (AgNPs) show some variability in the spectral patterns, even though the enhanced carboxilate and amino features were ever ascribed as preferable adsorption site. Based on DFT calculations the vibrational assignment allows the reinterpretation of previous published works. The investigations showed that both the high affinity of indole moiety for the AuNP surfaces make these substrates adequate for studying the adsorption of peptides containing Trp and the proposed SERS assignments could be helpful for further studies of more complex structures.

  12. Detection of Pseudomonas aeruginosa Metabolite Pyocyanin in Water and Saliva by Employing the SERS Technique

    Directory of Open Access Journals (Sweden)

    Olga Žukovskaja

    2017-07-01

    Full Text Available Pyocyanin (PYO is a metabolite specific for Pseudomonas aeruginosa. In the case of immunocompromised patients, it is currently considered a biomarker for life-threating Pseudomonas infections. In the frame of this study it is shown, that PYO can be detected in aqueous solution by employing surface-enhanced Raman spectroscopy (SERS combined with a microfluidic platform. The achieved limit of detection is 0.5 μM. This is ~2 orders of magnitude below the concentration of PYO found in clinical samples. Furthermore, as proof of principle, the SERS detection of PYO in the saliva of three volunteers was also investigated. This body fluid can be collected in a non-invasive manner and is highly chemically complex, making the detection of the target molecule challenging. Nevertheless, PYO was successfully detected in two saliva samples down to 10 μM and in one sample at a concentration of 25 μM. This indicates that the molecules present in saliva do not inhibit the efficient adsorption of PYO on the surface of the employed SERS active substrates.

  13. SERS and DFT study of copper surfaces coated with corrosion inhibitor

    Directory of Open Access Journals (Sweden)

    Maurizio Muniz-Miranda

    2014-12-01

    Full Text Available Azole derivatives are common inhibitors of copper corrosion due to the chemical adsorption occurring on the metal surface that gives rise to a protective film. In particular, 1,2,4-triazole performs comparable to benzotriazole, which is much more widely used, but is by no means an environmentally friendly agent. In this study, we have analyzed the adsorption of 1,2,4-triazole on copper by taking advantage of the surface-enhanced Raman scattering (SERS effect, which highlights the vibrational features of organic ligand monolayers adhering to rough surfaces of some metals such as gold, silver and copper. To ensure the necessary SERS activation, a roughening procedure was implemented on the copper substrates, resulting in nanoscale surface structures, as evidenced by microscopic investigation. To obtain sufficient information on the molecule–metal interaction and the formation of an anticorrosive thin film, the SERS spectra were interpreted with the aid of theoretical calculations based on the density functional theory (DFT approach.

  14. Multi-branched gold nanostars with fractal structure for SERS detection of the pesticide thiram

    Science.gov (United States)

    Zhu, Jian; Liu, Mei-Jin; Li, Jian-Jun; Li, Xin; Zhao, Jun-Wu

    2018-01-01

    The surface-enhanced Raman scattering (SERS) activity of multi-branched gold nanostars with fractal structure has been investigated for trace detection of pesticide thiram. Raman spectrum results show that the gold nanostars substrate can produce about 102 fold stronger signal than the thiram alone with the thiram concentration increase of 103 times and 1.4 fold stronger signal than the gold nanostars without fractal feature. In the detection procedure, the most prominent SERS peak at 1376 cm- 1 has been chosen to characterize and quantify the concentration of thiram. Experimental results indicate this Raman substrate based on fractal gold nanostars exhibits excellent selective probing performance for thiram with a detection limit as low as 10- 10 M in solution and 0.24 ng/cm2 in apple peels. Interference experiment results show that the effects from the interfering pesticides could be neglected in the detection procedure. Therefore, the gold nanostars as a SERS substrate have excellent sensitivity and selectivity.

  15. O ser com AIDS em sua dimensão existencial

    Directory of Open Access Journals (Sweden)

    Dorotea Erica Dresler

    1993-03-01

    Full Text Available A inquietação sobre o significado de estar com AIDS, sob a perspectiva da pessoa que vivência a doença, levou as autoras a uma pesquisa que as norteie para uma assistência de enfermagem que contemple o doente em sua dimensão existencial. Desta forma, utilizando os passos de uma investigação fenomenológica, puderam, a partir dos discursos das pessoas sobre as suas experiências vividas de um ser com AIDS, desvelar facetas que integram a essência desse vivenciar e que o afetam enquanto um ser histórico. O momento crítico de revelação do diagnóstico, o conviver com a doença e com os sintomas a ela inerentes, a perspectiva de finitude próxima, a configuração de seu horizonte existencial face ao que lhes está acontecendo, foram facetas que emergiram e que são analisadas. Esses resultados contribuem, efetivamente, para uma assistência de enfermagem que assegure aos doentes o exercício de sua condição primordial de ser humano: a sua dimensão existencial.

  16. Estar críticamente enfermo significa no ser capaz y no poder decidir

    Directory of Open Access Journals (Sweden)

    Oscar Beltrán Salazar

    Full Text Available Objetivo: Describir el significado para los pacientes críticamente enfermos hospitalizados en UCI de la experiencia de ser dependientes de los enfermeros para la satisfacción de las necesidades. Metodología: Investigación con enfoque fenomenológico realizada en Medellín en 2006; incluyó a nueve personas adultas entre 24 y 80 años que estuvieron críticamente enfermos y hospitalizados en UCI. La entrevista en profundidad se utilizó para la recolección de información. Los datos se analizaron según el esquema propuesto por Cohen, Kahan y Steeves. Resultados: Depender de otras personas para actuar y para decidir, el sufrimiento y el dolor influyen en la dureza de la experiencia de padecer una enfermedad grave. Discusión: No ser capaz de autosatisfacer las necesidades propias y no poder tomar decisiones contribuyen para que la experiencia de padecer una enfermedad grave sea "dura y difícil". Conclusión: la dependencia de los pacientes que padecen una enfermedad grave no debe ser asumida por los enfermeros sino que debe evaluarse en cada caso, lo mismo que las respuestas a dicha dependencia para asegurar el respeto por los derechos de las personas enfermas.

  17. Prominent stylistic aspects in music of Nāser Khosrow's poetry

    Directory of Open Access Journals (Sweden)

    Morteza Mohseni

    2017-04-01

    Full Text Available It is axiomatic  for those who are stylistically a little familiar  about  the periods of  Persian  poetry  that  quasidas  of  Nāser-e Khosrow are totally  different  from  those  of  the  poets  in  fifth  lunar  century  both  in  terms  of  their  contents  and  technically.  This difference  is  seen  even  in  those  areas  of  his  poetry in which the poet is confided to make innovations. This paper investigates Nāser-e Khosrow's style in the field of the music of poetry. It also aims to identify his slylistic differences comparing with those of his most famous contemporaries (Onsori, Farrokhi and Manoochehri in external, lateral and internal areas.      As the first  step, all the Nāser Khosrow's poems -exept for additions section- was considered the Scope of this study, accompanied by main parts of other three cited  poets' divans (poetical works which consists almost 23600 distiches. For the second stage, each poet's divan were separatly scrutinized in three fields of the music of poetry. The frequency of each cases were recorded and after comparing statistics related to Nāser-e Khosrow's poems with other tree poets,  stylistic charachteristics of his poetry were explored. Statistical information related to the poets were generally recorded in a table and some parts of them were shown in a bar graph. It seems necessary to note that the researcher considered two items of  innovation and frequncy in all phases of the study.     Most of the studies done in the field of Nāser-e Khosrow's music of poetry, investigated the prosody and meter of his poetry. Most of these studies considered difficulty and relevancy as the important prosodic characteristics of  his poetry. Regarding the lateral and internal areas of Nāser-e Khosrow's poetry, there are not much argument proposed except for using difficult rhymes and nominal radifs ( for lateral music of poetry and attending to figures of

  18. SER Derivation and Power Optimization of a Two-Way MultiRelay Cooperative Communication System

    Directory of Open Access Journals (Sweden)

    Shakeel-Ur-Rehman Rehman

    2014-01-01

    Full Text Available In this paper, we consider Rayleigh fading based cooperative communication system with AaF (Amplify and Forward relaying using multiple relays. We take spectrally efficient two-way model of cooperative communication terminals and formulate performance evaluation framework in terms of SER (Symbol Error Rate. We not only consider fading channel for this performance evaluation but also consider the effect of relay terminal location into our model which does not require any CSI (Channel State Information at transmitting nodes. We have proposed power allocation framework for these nodes and analytically derived SER performance results. We have numerically evaluated this framework for power optimization as well as minimizing required SER. Significant performance improvement as compared with equal power sharing among the cooperating terminals is achieved using our proposed framework. It is shown that virtual cooperative antenna configurations is able to demonstrate up to 3dB gain as compared with co-located antenna configurations. Thus incorporating relay location information for performance evaluation results significant power savings

  19. Similarities and differences in the spectral behavior of W Ser and UX Mon in the ultraviolet

    Science.gov (United States)

    Sanad, M. R.; Bobrowsky, M.

    2013-04-01

    We present ultraviolet spectra of two eclipsing interacting binary systems, W Ser and UX Mon, with good coverage over the 14.16-day and 5.9-day orbital periods, respectively, using observations taken by the International Ultraviolet Explorer ( IUE) during the period between 1978-1993 and 1981-1991. Two profiles of W Ser and UX Mon showing variations of line fluxes at two orbital phases are presented. This paper focuses on the N V emission line at 1240 Å, C II emission line at 1336 Å, C IV emission line at 1550 Å, O III emission line at 1666 Å and the Si III emission line at 1892 Å, produced in an extended gaseous envelope around the mass-gaining component by calculating spectral line fluxes. Our results show that there are variations of line fluxes with time, similar to the light curves found for both W Ser and UX Mon. We attribute these spectral variations to eclipse effects and to variations in the mass transfer rate. These results from the IUE observations support the thick disk model around the primary star in which variations of mass transfer affect the observed radiation from the gaseous envelope around the hot star. Future, high-resolution imaging is recommended to confirm the inferred asymmetrical circumstellar envelopes.

  20. SERS and fluorescence-based ultrasensitive detection of mercury in water.

    Science.gov (United States)

    Makam, Pandeeswar; Shilpa, Rohilla; Kandjani, Ahmad Esmaielzadeh; Periasamy, Selvakannan R; Sabri, Ylias Mohammad; Madhu, Chilakapati; Bhargava, Suresh Kumar; Govindaraju, Thimmaiah

    2018-02-15

    The development of reliable and ultrasensitive detection marker for mercury ions (Hg 2+ ) in drinking water is of great interest for toxicology assessment, environmental protection and human health. Although many Hg 2+ detection methods have been developed, only few offer sensitivities below 1pM. Herein, we describe a simple histidine (H) conjugated perylene diimide (PDI) bolaamphiphile (HPH) as a dual-responsive optical marker to develop highly selective and sensitive probe as visible (sol-to-gel transformation), fluorescence and SERS-based Hg 2+ sensor platform in the water. Remarkably, HPH as a SERS marker supported on Au deposited monodispersed nanospheres monolayers (Au-MNM) of polystyrene offers an unprecedented selectivity and the best ever reported detection limit (LOD) of 60 attomolar (aM, 0.01 parts-per-quadrillion (ppq)) for Hg 2+ in water. This is ten orders of magnitude lower than the United States Environmental Protection Agency (USEPA) tolerance limit of Hg 2+ in drinking water (10nM, 2 ppb). This simple and effective design principle of host-guest interactions driven fluorescence and SERS-based detection may inspire the future molecular engineering strategies for the development of ultrasensitive toxic analyte sensor platforms. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Green synthesis of gold nanoparticles by Allium sativum extract and their assessment as SERS substrate

    Science.gov (United States)

    Coman, Cristina; Leopold, Loredana Florina; Rugină, Olivia Dumitriţa; Barbu-Tudoran, Lucian; Leopold, Nicolae; Tofană, Maria; Socaciu, Carmen

    2014-01-01

    A green synthesis was used for preparing stable colloidal gold nanoparticles by using Allium sativum aqueous extract both as reducing and capping agent. The obtained nanoparticles were characterized by UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy. Moreover, their potential to be used as surface-enhanced Raman scattering (SERS) substrate was investigated. The obtained gold nanoparticles have spherical shape with mean diameters of 9-15 nm (depending on the amount of reducing agent used under boiling conditions) and are stable up to several months. FTIR spectroscopy shows that the nanoparticles are capped by protein molecules from the extract. The protein shell offers a protective coating, relatively impervious to external molecules, thus, rendering the nanoparticles stable and quite inert. These nanoparticles have the potential to be used as SERS substrates, both in solution and inside human fetal lung fibroblast HFL-1 living cells. We were able to demonstrate both the internalization of the nanoparticles inside HFL-1 cells and their ability to preserve the SERS signal after cellular internalization.

  2. LA ELOCUENCIA, SISTEMA DE VIDA ÍNSITO EN EL SER HUMANO

    Directory of Open Access Journals (Sweden)

    Bulmaro Reyes Coria

    2013-01-01

    Full Text Available Resumen Este artículo se funda en el repaso directo de las preceptivas retóricas aristotélica y ciceroniana, incluida la Retórica a Herenio. Pretende mostrar que la elocuencia, o retórica, no es una simple asignatura escolar que se desliga de la esencia del ser humano, sino un sistema que le es inherente a este. Tal sistema es capaz de ser cultivado y fortalecido por el estudio o la ejercitación, y estas dos tareas constituyen el lugar donde se nutre la invención: ahí se hace evidente la materia prima de los entimemas, ahí el ser humano cobra consciencia de que ese otro sistema es parte de su integridad, a pesar de que le sea intangible al tacto, como lo era para Sancho, quien, sin embargo, no podía vivir sin hablar ni siquiera contra los mandatos del amo.

  3. LA ELOCUENCIA, SISTEMA DE VIDA ÍNSITO EN EL SER HUMANO

    Directory of Open Access Journals (Sweden)

    Bulmaro Reyes Coria

    2013-01-01

    Full Text Available Este artículo se funda en el repaso directo de las preceptivas retóricas aristotélica y ciceroniana, incluida la Retórica a Herenio. Pretende mostrar que la elocuencia, o retórica, no es una simple asignatura escolar que se desliga de la esencia del ser humano, sino un sistema que le es inherente a este. Tal sistema es capaz de ser cultivado y fortalecido por el estudio o la ejercitación, y estas dos tareas constituyen el lugar donde se nutre la invención: ahí se hace evidente la materia prima de los entimemas, ahí el ser humano cobra consciencia de que ese otro sistema es parte de su integridad, a pesar de que le sea intangible al tacto, como lo era para Sancho, quien, sin embargo, no podía vivir sin hablar ni siquiera contra los mandatos del amo.

  4. Novel Ser79Leu and Ser81Ile substitutions in the quinolone resistance-determining regions of ParC topoisomerase IV and GyrA DNA gyrase subunits from recent fluoroquinolone-resistant Streptococcus pneumoniae clinical isolates.

    Science.gov (United States)

    Korzheva, Nataliya; Davies, Todd A; Goldschmidt, Raul

    2005-06-01

    Resistance of Streptococcus pneumoniae to fluoroquinolones is caused predominantly by amino acid substitutions at positions Ser79 of ParC and Ser81 of GyrA to either Phe or Tyr encoded in the quinolone resistance-determining regions of the parC topoisomerase IV and gyrA DNA gyrase genes. Analysis of highly resistant clinical isolates identified novel second-step substitutions, Ser79Leu (ParC) and Ser81Ile (GyrA). To determine contributions of these new mutations to fluoroquinolone resistance either alone or in combination with other Ser79/81 alleles, the substitutions Ser79Leu/Phe/Tyr in ParC and Ser81Ile/Phe/Tyr in GyrA were introduced into the R6 background, resulting in 15 isogenic strains. Their level of fluoroquinolone resistance was determined by susceptibility testing for ciprofloxacin, levofloxacin, moxifloxacin, gatifloxacin, gemifloxacin, garenoxacin, and norfloxacin. Leu79 and Ile81 alone as well as 79/81Phe/Tyr substitutions did not contribute significantly to resistance, with fluoroquinolone MICs increasing two- to fourfold compared to wild type for all agents tested. Fluoroquinolone MICs for double transformants ParC Ser79Phe/Tyr/Leu-GyrA Ser81Phe/Tyr were uniformly increased by 8- to 64-fold regardless of pairs of amino acid substitutions. However, combinations including Ile81 conferred two- to fourfold-higher levels of resistance than did combinations including any other Ser81 GyrA substitution, thus demonstrating the differential effects of diverse amino acid substitutions at particular hotspots on fluoroquinolone MICs.

  5. Endurecimiento superficial de aceros y fundiciones mediante láser de Nd: YAG

    Directory of Open Access Journals (Sweden)

    Sagaró, R.

    2001-10-01

    Full Text Available This work relates with heat treatment by laser of metallic surfaces. The hardening of steels AISI 1045, W1, W112 and flake and nodular cast irons was carried out using a Nd: YAG laser. Operation parameters of laser like beam power (P and traverse speed of the laser Spot (V are closely related to the depth of hardening. The authors present some analyses on metallographic studies. In all cases Vickers microhardness valves of about 500-900 HV (three or four times higher than original substrates. Relations between microhardness and depth of hardening are presented for the processed materials. Experimental results showed that the scan speed increase produces a decrease on depth of hardening as reported by others researchers. On the other hand, the samples with higher carbon content show lower hardenining depth. In addition, tribological tests were carried out. These tests show wear resistance when compared with conventional heat treatment. The frictional coefficient decrease in the samples with laser surface treatment.

    En el trabajo se presentan los resultados del tratamiento térmico superficial, con técnica láser, de superficies metálicas. Con el empleo de un láser de Nd:YAG se procedió al endurecimiento superficial de los aceros AISI 1045, W1, W112 y fundiciones de tipo laminar y nodular. Se presentan los resultados del tratamiento térmico superficial atendiendo al parámetro velocidad de barrido del haz de láser (V. De igual forma se estudian las microestructuras metalográficas obtenidas. En todos los casos, se obtienen valores de microdureza Vickers que oscilan entre los 500-900 HV (incrementos de tres-cuatro veces respecto al material base. Los resultados obtenidos permiten afirmar que, en todos los casos estudiados, el incremento de la velocidad de barrido provocó una disminución de la profundidad de la capa endurecida, en correspondencia con otros resultados expuestos en la literatura especializada. Las experiencias del

  6. High-Throughput Fabrication of Nanocone Substrates through Polymer Injection Moulding For SERS Analysis in Microfluidic Systems

    DEFF Research Database (Denmark)

    Viehrig, Marlitt; Matteucci, Marco; Thilsted, Anil H.

    Metal-coated nanostructured surfaces have shown promise as substrates for surface-enhanced Raman spectroscopy (SERS) as they allow chemical trace detection with high sensitivity and rapid response. This sensitivity and specificity makes SERS especially interesting for environmental and biological...

  7. A Dutch translation of the Self-Efficacy for Rehabilitation Outcome Scale (SER) : a first impression on reliability and validity

    NARCIS (Netherlands)

    Stevens, M; van den Akker-Scheek, [No Value; van Horn, [No Value; Akker-Scheek, I.; van Horn, J.R.

    Self-efficacy is a relevant factor during rehabilitation after total hip or knee arthroplasty. Research was done into the reliability and validity of a Dutch translation of the Self-Efficacy for Rehabilitation Outcome Scale (SER). One hundred and forty-one persons filled in the SER questionnaire and

  8. El modo de ser cínico de los dirigentes The Way of Being Cynical of the Leaders

    Directory of Open Access Journals (Sweden)

    Álvaro Zapata Domínguez

    2009-06-01

    Full Text Available Bédard (1995, 2002, ha identificado tres modos de ser que ella designa como “Modo de Ser mítico”, “Modo de Ser sistemático”, “Modo de Ser pragmático”, un cuarto modo de Ser, el “Modo de Ser relacional” ha sido propuesto por Alain Chanlat (1995. Estos modos de Ser, son para los autores, la manifestación de las grandes tendencias del pensamiento occidental. En este contexto en el presente artículo se desarrolla el “Modo de Ser Cínico” de los dirigentes. Los valores fundamentales que distinguen el cinismo, son: la resistencia, la impasibilidad, la maldad.Bédard (1995, 2002, has identified three manners of being, that she designates as the “Way of being mythical”, the “Way of being systematic”, and the “Way of being pragmatic”. A fourth way of being, the “Way of being relational” has been proposed by Alain Chanlat (1995. These ways of being, are for the authors, the manifestation of big trends in Western thought. In this context, in the present article, the “Way of being cynical” of the leaders is developed. The fundamental values that distinguish the cynicism are: resistance, impassivity and evil.

  9. Ser respetuoso es ser persona. El niño y la pedagogía moral de los nahuas del centro de México

    Directory of Open Access Journals (Sweden)

    Lorente Fernández, David

    2012-12-01

    Full Text Available Inside informal education, the teaching of respect results decisive for Central Mexico indigenous nahua. The respect is the moral value through which a human being becomes a «person». This pedagogical process has been barely studied and has not been solved how children grabs this important tool to conduce themselves among the family and the community life. Based on an extended fieldwork performed on the Texcoco Sierra area, located close to Mexico City, in which the more common adscription features, as the indigenous language and dress has disappeared due the modernization process, this article shows that respect constitutes a solid base to preserve ethnic identity. Children are educated through oral tales and the participation on a vast array of activities on the daily life. Despite the fact to be under «mestizo» respect, which is taught on schools, the nahua morality exists among the children as «granted» and constitutes the lifestyle of the Sierra.

    En el seno de la educación informal, la transmisión infantil del respeto resulta determinante para los indígenas nahuas del centro de México. El respeto es el valor moral principal que permite convertir a un ser humano en «persona». Sin embargo, este proceso pedagógico ha sido escasamente analizado y en gran parte continúa siendo un enigma cómo los niños adquieren lo que representa su más valiosa herramienta para conducirse adecuadamente en la vida familiar y comunitaria. Basándome en un prolongado trabajo de campo realizado en la región de la Sierra de Texcoco, cercana a la Ciudad de México, en la que los rasgos de autoascripción más convencionales, como el idioma indígena y la vestimenta tradicional, han desaparecido por los embates de los procesos de modernización, el artículo demuestra que inculcar el respeto constituye una sólida base para la conservación de la identidad étnica. Los niños son educados con relatos orales y mediante su participación en las

  10. Synthesis of micro-sized shell-isolated 3D plasmonic superstructures for in situ single-particle SERS monitoring

    Science.gov (United States)

    Zhang, Kun; Zhao, Jingjing; Ji, Ji; Liu, Baohong

    2016-04-01

    A single-particle SERS system enabling real-time and in situ observation of Au-catalyzed reactions has been developed. Both the catalytic activity and the SERS effect are coupled into a single bi-functional 3D superstructure comprising Au nanosatellites self-assembled onto a shell-insulated Ag microflower core, which eliminates the interference from photocatalysis.A single-particle SERS system enabling real-time and in situ observation of Au-catalyzed reactions has been developed. Both the catalytic activity and the SERS effect are coupled into a single bi-functional 3D superstructure comprising Au nanosatellites self-assembled onto a shell-insulated Ag microflower core, which eliminates the interference from photocatalysis. Electronic supplementary information (ESI) available: Details of the synthesis and characterization of the Ag@SiO2@Au superstructures (SEM and TEM images, UV/vis and SERS spectra). See DOI: 10.1039/c6nr00278a

  11. A wafer-scale backplane-assisted resonating nanoantenna array SERS device created by tunable thermal dewetting nanofabrication

    Science.gov (United States)

    Chang, Te-Wei; Ranjan Gartia, Manas; Seo, Sujin; Hsiao, Austin; Logan Liu, Gang

    2014-04-01

    A tunable lithography-less nanofabrication process using a metal thin-film thermal dewetting technique has been developed to fabricate wafer-scale and uniform plasmonic substrates at low cost for optimal performance in surface enhanced Raman scattering (SERS) applications. The relationship between the tunable parameters of this process and the corresponding optical and plasmonic characteristic is investigated both experimentally and theoretically to understand the deterministic design of an optimal SERS device with a three-dimensional plasmonic nanoantenna structure. The enhancement of SERS using various nanoplasmonic particle sizes, structure lengths, lateral hot spot spacings and resonating effects are examined and demonstrated. We achieve a uniform optimal enhancement factor of 1.38 × 108 on a 4 in wafer-scale SERS substrate with a backplane-assisted resonating nanoantenna array design. Sensitive environmental nitrate sensing, vitamin detection and oligonucleotide identification are demonstrated on the high-performance SERS device.

  12. A green, reusable SERS film with high sensitivity for in-situ detection of thiram in apple juice

    Science.gov (United States)

    Sun, Hongbao; Liu, Hai; Wu, Yiyong

    2017-09-01

    We report a green and reusable surface-enhanced Raman scattering (SERS) film based on PMMA/Ag NPs/graphene. By using this Raman substrate, the SERS signals of R6G were significantly enhanced reaching a minimum detectable concentration of 5 × 10-8 M, due to having lots of hot spots adhered backside to the exposed graphene. The SERS film can be used for in-situ monitoring of trace thiram in apple juice with a detection limit of 1 × 10-6 M (0.24 ppm), which is below the maximal residue limit (MRL) of 7 ppm in fruit prescribed by the U.S. Environmental Protection Agency (EPA). Furthermore, reusability studies show that the SERS film can be used repeatedly. In addition, the graphene-enhanced SERS technique shows great potential applications for the in-situ detection and identification of pesticide residues in environmental water, fruits and vegetables.

  13. Highly Sensitive Magnetic-SERS Dual-Function Silica Nanoprobes for Effective On-Site Organic Chemical Detection

    Science.gov (United States)

    Jeong, Cheolhwan; Kim, Hyung-Mo; Park, So Yeon; Cha, Myeong Geun; Park, Sung-Jun; Kyeong, San; Pham, Xuan-Hung; Hahm, Eunil; Ha, Yuna; Jeong, Dae Hong; Jun, Bong-Hyun; Lee, Yoon-Sik

    2017-01-01

    We report magnetic silver nanoshells (M-AgNSs) that have both magnetic and SERS properties for SERS-based detection. The M-AgNSs are composed of hundreds of Fe3O4 nanoparticles for rapid accumulation and bumpy silver shell for sensitive SERS detection by near-infrared laser excitation. The intensity of the SERS signal from the M-AgNSs was strong enough to provide single particle-level detection. We obtained much stronger SERS signal intensity from the aggregated M-AgNSs than from the non-aggregated AgNSs. 4-Fluorothiophenol was detected at concentrations as low as 1 nM, which corresponds to 0.16 ppb. The limit of detection for tetramethylthiuram disulfide was 10 μM, which corresponds to 3 ppm. The M-AgNSs can be used to detect trace amounts of organic molecules using a portable Raman system. PMID:28608835

  14. Highly Sensitive Magnetic-SERS Dual-Function Silica Nanoprobes for Effective On-Site Organic Chemical Detection

    Directory of Open Access Journals (Sweden)

    Cheolhwan Jeong

    2017-06-01

    Full Text Available We report magnetic silver nanoshells (M-AgNSs that have both magnetic and SERS properties for SERS-based detection. The M-AgNSs are composed of hundreds of Fe3O4 nanoparticles for rapid accumulation and bumpy silver shell for sensitive SERS detection by near-infrared laser excitation. The intensity of the SERS signal from the M-AgNSs was strong enough to provide single particle-level detection. We obtained much stronger SERS signal intensity from the aggregated M-AgNSs than from the non-aggregated AgNSs. 4-Fluorothiophenol was detected at concentrations as low as 1 nM, which corresponds to 0.16 ppb. The limit of detection for tetramethylthiuram disulfide was 10 μM, which corresponds to 3 ppm. The M-AgNSs can be used to detect trace amounts of organic molecules using a portable Raman system.

  15. Inhibition of deubiquitinating activity of USP14 decreases tyrosine hydroxylase phosphorylated at Ser19 in PC12D cells.

    Science.gov (United States)

    Nakashima, Akira; Ohnuma, Syuhei; Kodani, Yu; Kaneko, Yoko S; Nagasaki, Hiroshi; Nagatsu, Toshiharu; Ota, Akira

    2016-04-15

    Tyrosine hydroxylase (TH) is the rate-limiting enzyme in catecholamine biosynthesis, and its stability is a fundamental factor to maintain the level of the catecholamines in cells. However, the intracellular stability determined by the degradation pathway remains unknown. In this study, we investigated the mechanism by which phosphorylation of TH affected the proteasome pathway. The inhibition of proteasomes by MG-132 increased the percentage of TH molecules phosphorylated at their Ser19, Ser31 and/or Ser40 among the total TH proteins to about 70% in PC12D cells over a 24-hr period; although the percentage of phosphorylated TH molecules was about 20% under basal conditions. Moreover, the inhibition of proteasomes by epoxomicin with high specificity increased primarily the quantity of TH molecules phosphorylated at their Ser19. The phosphorylation of Ser19 potentiated Ser40 phosphorylation in cells by a process known as hierarchical phosphorylation. Therefore, the proteasome inhibition might result in an increase in the levels of all 3 phosphorylated TH forms, thus complicating interpretation of data. Conversely, activation of proteasome degradation by IU-1, which is an inhibitor for the deubiquitinating activity of USP14, decreased only the quantity of TH molecules phosphorylated at their Ser19, although it did not decrease that of TH phosphorylated at its Ser31 and Ser40 or that of TH molecules. These results suggest that the phosphorylation of Ser19 in the N-terminal portion of TH is critical as a trigger for the degradation of this enzyme by the ubiquitin-proteasome pathway. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Synergistic effects of semiconductor substrate and noble metal nano-particles on SERS effect both theoretical and experimental aspects

    Science.gov (United States)

    Yang, Chen; Liang, Pei; Tang, Lisha; Zhou, Yongfeng; Cao, Yanting; Wu, Yanxiong; Zhang, De; Dong, Qianmin; Huang, Jie; He, Peng

    2018-04-01

    As a means of chemical identification and analysis, Surface enhanced Raman spectroscopy (SERS), with the advantages of high sensitivity and selectivity, non-destructive, high repeatability and in situ detection etc., has important significance in the field of composition detection, environmental science, biological medicine etc. Physical model of coupling effect between different semiconductor substrates and noble metal particles were investigated by using 3D-FDTD method. Mechanism and the effects of excitation wavelength, particle spacing and semiconductor substrate types on the SERS effect were discussed. The results showed that the optimal excitation wavelengths of three noble metals of Ag, Au, Cu, were located at 510, 600 and 630 nm, respectively; SERS effect of Ag, Au, Cu increases with the decreasing of the inter distance of particles, while the distance of the NPs reaches the critical value of 3 nm, the strength of SERS effect will be greatly enhanced. For the four different types of substrate of Ge, Si, SiO2 (glass) and Al2O3, the SERS effect of Ag on SiO2 > Ge > Al2O3 > Si. For Au and Cu nanoparticles, the SERS effect of them on oxide substrate is stronger than that on non-oxide substrate. In order to verify FDTD simulations, taking silver nanoparticles as an example, and silver nanoparticles prepared by chemical method were spinning coating on the four different substrates with R6G as probe molecules. The results show that the experimental results are consistent with FDTD theoretical simulations, and the SERS enhancement effect of Ag-SiO2 substrate is best. The results of this study have important theoretical significance to explain the variations of SERS enhancement on different noble metals, which is also an important guide for the preparation of SERS substrates, especially for the microfluidics. The better Raman effect can be realized by choosing proper substrate type, particle spacing and excitation wavelength, result in expanding the depth and width

  17. Compreendendo o ser da pessoa com câncer: suas posturas e possibilidades existenciais

    Directory of Open Access Journals (Sweden)

    Karina Machado Siqueira

    2008-09-01

    Full Text Available O número expressivo de pessoas que buscam as instituições de saúde para o tratamento do câncer nos leva a assumir uma postura reflexiva em relação à forma com que vêm sendo cuidadas pelos profissionais de saúde. O desenvolvimento deste estudo teve como propósito desvelar o significado de ser-com-câncer para pacientes oncológicos, buscando compreendê-los nesse vivenciar e vislumbrando a descoberta de novos caminhos para o cuidado a essas pessoas. Sustentando-me no entendimento de que somente as pessoas que experimentam a situação de adoecer com câncer são capazes de transmitir o sentido e o significado do que estão vivendo, optei pela metodologia da pesquisa qualitativa – modalidade fenomenológica, baseada no referencial filosófico de Edmund Husserl. Foram realizadas entrevistas junto a onze pacientes internados em uma instituição de saúde especializada no tratamento do câncer, localizada em Goiânia – GO. Todos os pacientes eram adultos e estavam conscientes do diagnóstico. Apropriei-me de algumas idéias da ontologia existencial de Martin Heidegger para melhor desenvolver a análise dos dados. Pude apreender que o câncer mostra-se ao Ser que vive essa situação de doença como uma experiência difícil, saturada de sofrimento e dor. O recebimento do diagnóstico revelou-se como um dos piores momentos para o paciente, quando vivencia, dentre outros sentimentos, a angústia diante do desconhecido e o medo da morte. Ao aproximar-me do mundo-vida dessas pessoas, percebi o quanto o câncer, enquanto realidade na vida do Ser, pode afetar tanto sua autopercepção e seu comportamento, quanto suas relações sociais. A partir do momento em que o Ser se depara com a realidade de existir com uma doença grave, diversos projetos existenciais tendem a ser anulados ou modificados pela situação vivida. Ao se depararem com a necessidade de conviver com um problema de saúde grave, as pessoas buscam, em muitos casos, formas de

  18. IMPACT OF ADVANCED REPRODUCTIVE BIOTECHNOLOGIES ON ANIMAL HEALTH AND LIVESTOCK PRODUCTION EL IMPACTO DE LA BIOTECNOLOGÍA REPRODUCTIVA AVANZADA EN LA SALUD Y LA REPRODUCCIÓN ANIMAL

    Directory of Open Access Journals (Sweden)

    Bertolini Marcelo

    2009-05-01

    parto, distocias, y nacimiento de terneros grandes con baja supervivencia postnatal. Las bajas tasas de preñez con las altas tasas de pérdidas gestacionales representan pérdidas económicas significativas por baja prolificidad. El entendimiento de los mecanismos de crecimiento prenatal durante el desarrollo normal y en aquellos relacionados con el síndrome sería muy significativo en la prevención, atenuación de las anormalidades de ocurrencia común en el ganado, con implicaciones directas a nivel científico y económico.

  19. ser blando en puntos de acupuntura para el tratamiento de enfermedades bucales

    Directory of Open Access Journals (Sweden)

    CAROLINA J VALIENTE ZALDÍVAR

    1997-06-01

    Full Text Available La radiación láser blanda o de baja energía es de uso terapéutico, pues en ella predomina un efecto fotoquímico que desencadena, a nivel celular, reacciones bioquímicas, bioenergéticas y bioeléctricas, lo que produce en el organismo un efecto al reducir el dolor, el edema y estimular la regeneración tisular, según el depósito energético que se realice. Teniendo en cuenta que la medicina tradicional oriental considera que las enfermedades se producen a consecuencia de un desequilibrio energético en la zona lesionada, y por ende, en el organismo, se trata de lograr estabilidad de la energía estimulando puntos de acupuntura con agujas, moxa, presión digital, etcétera, y en la actualidad con láser (técnica denominada laserpuntura. Presentamos el procedimiento terapéutico para la utilización del láser blando sobre puntos de acupuntura y se hacen recomendaciones con puntos de acción general que apoyan este procedimiento.The soft or low energy laser radiation has a therapeutic use due to its photochemical effect that causes at the cellular level biochemical, bioenergetic and bioelectric reactions, which reduce pain and edema and stimulate tissue regeneration, according to the energetic depot made. Taking into account that the oriental traditional medicine considers that diseases result from an energetic unbalance in the injured zone, and consequently in the organism, energy stability in tried to be achieved by stimulating acupuncture points with needles, moxa, digital pressure, etc., and at present with laser (this technique is called laserpuncture. The therapeutical procedure for the utilization of soft laser on acupuncture points is presented, and recommendations with points of general action supporting this procedure are made.

  20. Outra mente que ser: revolvendo questões à luz da pedagogia do oprimido

    Directory of Open Access Journals (Sweden)

    Lovison, Aida Maria

    2008-01-01

    Full Text Available Neste texto, a ética da alteridade de Emmanuel Levinas, para quem a nudez do rosto não é uma figura de estilo, mas a consciência moral, encontra a teoria da ação (cultural dialógica, fundamento, na pedagogia do oprimido de Paulo Freire, de sua denúncia-anúncio contra a desumanização e a opressão. Para ambos, a violência toma o sentido de posse, modo pelo qual um ente, embora existindo, é parcialmente negado. Essa parcialidade, ao negar a independência do ente, instaura a opressão, negando ao oprimido a sua vocação de ser mais. A opressão mata a vida. Contudo, é pela tomada de consciência desta condição de ser-para-outro, que a própria possibilidade do humano pode ser pensada, porque a relação com outrem ou com a coletividade é nossa relação, irredutível à compreensão. Reconhecer tal subversão, ou seja, que os oprimidos, na medida em que se libertam, eles evitam a volta ao regime opressor e, ao fazê-lo, libertam o opressor, eles inauguram o amor não é assumir, em essência, que ética é a construção do sentido da vida humana desde o encontro com o outro?

  1. Controllable synthesis and SERS characteristics of hollow sea-urchin gold nanoparticles.

    Science.gov (United States)

    Li, Junpeng; Zhou, Jun; Jiang, Tao; Wang, Binbing; Gu, Min; Petti, Lucia; Mormile, Pasquale

    2014-12-14

    Hollow sea-urchin gold nanoparticles (HSU-GNPs) were successfully prepared through a novel one-step galvanic replacement strategy, and their corresponding optical properties was studied in detail. During the synthesis process, the sizes of the interior hollows of the HSU-GNPs could be changed by adjusting the amount of silver nitrate added into hydrogen tetrachloroaurate trihydrate solution. The absorption spectra of the HSU-GNPs showed that the localized surface plasmon resonance (LSPR) peaks were red-shifted with increasing size of the interior hollows in the HSU-GNPs. When the added amount of silver nitrate was up to 6 μl, the LSPR peak of the synthesized HSU-GNP reached 726 nm as a maximum red-shift. Furthermore, the absorption spectra of the HSU-GNPs with different morphologies were theoretically simulated by the finite element method, which was consistent with the experimental results and explained the origin of the red-shift of the LSPR peaks. In addition, the surface-enhanced Raman scattering (SERS) of the sea urchin gold nanoparticles were also investigated using 4-mercaptobenzoic acid as a Raman reporter molecule. Both the experimental and calculated results showed that the HSU-GNPs had stronger SERS enhancement than the solid sea-urchin gold nanoparticles. In particular, the HSU-GNPs prepared by adding 6 μl silver nitrate exhibited a maximum SERS enhancement factor, EF = 1.1 × 10(9), due to the LSPR peak at 726 nm which is near to the excitation wavelength, 785 nm. This feature is significant for designing a biosensor with a super-high sensitivity based on the morphology of the HSU-GNPs.

  2. Ser mujer en el barrio : análisis de significados de ser mujer para las adultas mayores de los barrios Pañuelito, Delicias del Carmen y Unicerros, barrios populares de la localidad de Usaquén

    OpenAIRE

    Baracaldo Silva, Flor del Pilar

    2017-01-01

    Este estudio de tipo etnográfico busca reflexionar a partir de las historias de vida de un grupo de mujeres mayores, sobre la construcción de significados de ser mujer en el contexto de los barrios populares de la localidad de Usaquén. Sus narrativas se tejen alrededor de las tensiones de lo que implica el progreso en la ciudad en situación de migración y marginalidad, y a su vez en lo que esta búsqueda de salir adelante, o ser alguien en la vida. Confronta los significados de ser una mujer b...

  3. Histórias de reencontro: ancestralidade, pertencimento e enraizamento na descoberta de ser negra

    OpenAIRE

    Miriam Rosa dos Santos

    2014-01-01

    Este trabalho se propõe a compreender os processos subjetivos implicados na descoberta de ser negra. Analisamos o legado histórico deixado à população negra, a saber: o escravismo, o racismo e a ideologia do embranquecimento e os desdobramentos destes sobre a subjetividade da mulher negra. Apresentamos um breve panorama dos estudos da Psicologia sobre a temática racial. A pesquisa de campo se desenvolveu a partir do depoimento de três mulheres negras, de diferentes localidades do país, que em...

  4. Ser professor : marcas de identidade profissional equacionadas à luz da pedagogia social

    OpenAIRE

    Monteiro, Marta Patrícia Araújo

    2012-01-01

    O presente Sumário Executivo refere-se ao Relatório Reflexivo «Ser Professor: marcas de identidade profissional equacionadas à luz da Pedagogia Social», elaborado no âmbito do curso do Mestrado em Ciências da Educação, especialização em Pedagogia Social, da Faculdade de Educação e Psicologia da Universidade Católica Portuguesa (FEP- UCP), Porto. O documento em referência centra-se nas experiências e vivências que consideramos terem tido maior relevância no desenvolvimento profissional ao l...

  5. Requisitos e impedimentos para ser árbitro en el derecho español

    OpenAIRE

    Marcela Rodríguez Mejía

    2011-01-01

    La ley española de arbitraje, Ley 60 de 2003, contempla en distintos artículos los requisitos legales que debe reunir todo aquel que pretenda ser árbitro en una controversia regida por la misma, así como también, aquellas situaciones que de presentarse, les impedirán obrar como tal. Al mismo tiempo, y en consonancia con la prevalencia que da a la autonomía de la voluntad de las partes, el legislador español permitió que éstas acuerden otros requisitos a los futuros árbitros. Así las cosas, el...

  6. Antike Gläser und versteinertes Elfenbein: Röntgenanalyse in der Kunst

    Science.gov (United States)

    Reiche, Ina; Radtke, Martin; Brouder, Christian

    2003-03-01

    Physikalische Methoden der Archäometrie liefern den Kunsthistorikern und Archäologen wichtige Informationen. Materialspezifische Größen geben Aufschluss über Alter, Authentizität, Herkunft und Herstellungstechniken sowie Alterserscheinungen von Gegenständen. Insbesondere die Röntgenanalyse hat in jüngster Zeit wertvolle Beiträge hierzu geliefert. Dabei spannt sich ein weiter Bogen von den Mysterien ägyptischer Augenschminke über die Herstellungstechnik römischer Gläser bis zur Authentizitätsuntersuchung mittelalterlicher Silberstiftzeichnungen.

  7. SERS active systems of water-soluble polythiophene and plasmonic nanoparticles: preparation and optical properties

    Czech Academy of Sciences Publication Activity Database

    Kazim, Samrana; Pfleger, Jiří; Halašová, Klára; Procházka, M.; Bondarev, D.; Vohlídal, J.

    2011-01-01

    Roč. 55, č. 2 (2011), 23905_1-23905_6 ISSN 1286-0042. [International Symposium on Flexible Organic Electronics /3./. Ouranoupolis, 06.07.2010-09.07.2010] R&D Projects: GA AV ČR KAN100500652; GA MŠk 7E10040; GA ČR GAP208/10/0941 Institutional research plan: CEZ:AV0Z40500505 Keywords : nanocomposite * SERS * .pi.-conjugated polymer s Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.771, year: 2011

  8. Disfruto el poder de ser feliz: experiencia en personas que viven con VIH

    OpenAIRE

    Guadalupe Erendira Montoya Ramirez; Mayra Itzel Huerta Baltazar; Mónica Fulgencio Juárez; Gloria Correa Vieyra; Roberto Martinez Arenas

    2016-01-01

    Las personas que viven con virus de inmunodeficiencia humana (VIH) pueden presentar alteraciones biopsicosociales que generan infelicidad. La gaudibilidad (capacidad para ser feliz y disfrutar), puede favorecerse al crear nuevos patrones de conducta mental con la programación neurolingüística (PNL). El propósito fue: analizar la experiencia vivida en un taller de PNL para personas que viven con VIH, a la luz del referente teórico de; Rogers. Estudio cualitativo con diseño fenomenológico, part...

  9. Paradigmas de luz : a parapsicologia no redimensionamento cientifico do ser humano

    OpenAIRE

    Rosa Maria Viana

    2002-01-01

    Resumo: Este estudo tem como objetivo analisar o percurso histórico-conceitual da construção da Parapsicologia como um campo de conhecimento científico que se estrutura desde o século XIX dentro das concepções teóricas e critérios metodológicos preconizados pela ciencia. A tese central procura demonstrar que a Parapsicologia é uma das áreas da ciência atual que contribui para uma concepção mais ampla de Ser Humano entendido como multidimensional e multisensorial, o que também vem sendo indica...

  10. Kant, la Ilustración y la Domesticación del Ser Humano

    OpenAIRE

    Pele, Antonio

    2011-01-01

    RESUMENEste trabajo pretende entender qué idea de justicia implícita es inherente a las reflexiones de Kant sobre la Ilustración y en particular en su artículo publicado en 1784 sobre este tema. Para poder entender esta noción, demuestro cómo Kant pretende redefinir las relaciones entre el Estado y los individuos, neutralizando lo que llama la domesticación del ser humano. La liberación que surge de este proceso debe provocar una redefinición de la conducta política y legal del Estado en rela...

  11. Biomedical Applications of Micro-Raman and Surface-Enhanced Raman Scattering (SERS) Technology

    Science.gov (United States)

    2012-10-01

    al., "Visible, near-infrared, and ultraviolet laser- excited Raman spectroscopy of the monocytes/macrophages (U937) cells", J. Raman Spectrosc., 41...Visible, near-infrared, and ultraviolet laser-excited Raman spectroscopy of the monocytes/macrophages (U937) cells,” J. Raman Spectrosc., 41(3), 268...spectroscopy,” Journal of Photochemistry and Photobiology B-Biology, 16(2), 211-233 (1992). [17] K. Kneipp, H. Kneipp, and H. G. Bohr, “Single-molecule SERS

  12. Triplet and SERS study of crystal violet in presence of metal nanoparticles

    Science.gov (United States)

    Chadha, Ridhima; Maiti, Nandita; Kapoor, Sudhir

    2013-07-01

    Recently, it has been shown that triplet of methylene blue gets quenched by Au nanoparticles (J. Am. Chem. Soc. 132 (2010) 6298). Herein, we have shown that the reactivity of triplet crystal violet (CV), produced by ionizing radiation, is low towards Ag nanoparticles contrary to Au nanoparticles. Using absorption and surface-enhanced Raman spectroscopy (SERS) we have further examined the interaction of CV with Ag and Au nanoparticles. It has been shown that the polarizability of CV changes with the excitation wavelength and it is independent of metal nanoparticles.

  13. Microprocesos láser para la mejora de dispositivos fotovoltaicos basados en silicio cristalino

    OpenAIRE

    Sanchez Aniorte, Maria Isabel

    2013-01-01

    En los últimos años la tecnología láser se ha convertido en una herramienta imprescindible en la fabricación de dispositivos fotovoltaicos, ayudando a la consecución de dos objetivos claves para que esta opción energética se convierta en una alternativa viable: reducción de costes de fabricación y aumento de eficiencia de dispositivo. Dentro de las tecnologías fotovoltaicas, las basadas en silicio cristalino (c-Si) siguen siendo las dominantes en el mercado, y en la actualidad los esfuerzos c...

  14. Ética: la medida y la grandeza del ser humano

    OpenAIRE

    Alvira, Rafael

    2006-01-01

    De Acuerdo Con La Tradición Neoplatónica, El Texto Subraya El Carácter Centraldel Concepto De Límite O Medida, Particularmente En Relación Con La Práctica. Adiferencia De Lo Que Puede Parecer, Alcanzar Los Propios Límites, Lejos Deempequeñecer Al Ser Humano, Es Lo Que Le Concede Grandeza. La Grandeza De Ánimoque Nace En La Conciencia Correcta De La Propia Medida, Es La Virtud Más Bella Ysignificativa.

  15. Ser y acción en la obra del primer M. Blondel

    Directory of Open Access Journals (Sweden)

    José Javier FERNÁNDEZ PEREIRA

    2009-12-01

    Full Text Available RESUMEN: La pregunta por el ser cuando se hace desde la filosofía de la acción, como la de M. Blondel en su tesis L'Action. Essai d'une critique de la vie et d'une science de lapratiquede 1893, adquiere un interés inédito pues al integrar las aportaciones de la crítica moderna puede contribuir al replanteamiento de los viejos problemas ontológicos para dar origen a un -realismo superior» con sentido para el hombre de hoy.De la fenomenología integral de la acción se llega inevitablemente al planteamiento necesario del problema del ser. Puesto que la acción implica siempre una opción que es emergente respecto a sus condiciones científicas de posibilidad, ésta se convierte en la condición necesaria para que del conocimiento del ser se pase al ser en el conocimiento. La libertad se pone así en el centro de la ontología sin que ésta pierda su rigor racional.ABSTRACT: When the question about the being is made from the point of view of the action philosophy, as the one made by M. Blondel in his thesis L'Action. Essai d'une critique de la vie et d'une science de lapratique in 1893, adquires an unusual interest.By putting together the contributions of modern critic, it may help us to consider again the oíd ontological problems and so give rise to a superior realism with meaning for up-to-date man.The action integral phenomenology takes us inevitably to a necessary reconsideration of the problem of being. Since the action always implies an emerging option regarding its scientific condition of possibility, it becomes the necessary condition for the knowledge of the being to turn into the being in the knowledge. Thus, freedom becomes the centre of ontology with no loss of its rational exactness.

  16. Entre la libertad de ser y hacer: un proyecto de vida para elegir

    OpenAIRE

    Márquez-Fernández, Álvaro B.

    2011-01-01

    La Filosofía para Niños y Niñas de M. Lipman, promueve una praxis de la vida que considera la libertad como el auténtico proyecto de realización individual y social, que debe ser asumido desde la infancia. Propiciar una experiencia investigativa y dialógica que le permita a los niños y las niñas problematizar filosóficamente la realidad, es decir, indagar acerca del sentido de cualquier acción, acto, praxis tiene su punto de origen en un interrogar-se por la libertad como experiencia que hace...

  17. Arnold Gehlen, reflexões sobre ser humano

    Arnold Gehlen, reflections on human being

    OpenAIRE

    Javier Ignacio Vernal

    2009-01-01

    PortuguesEste manuscrito trata da concepção de Arnold Gehlen sobre ser humano. A tese de Gehlen é a do homem biologicamente deficiente que através da atividade de transformação da matéria e do meio de acordo com suas necessidades, se constitui diverso dos outros animais. Esse agir humano, que gera a distância progressiva em relação aos outros animais, pressupõe a abertura especificamente humana para o mundo. A cultura é considerada por Gehlen como o espaço e o ambiente necessários para a vida...

  18. O espaço em Quem me dera ser onda, de Manuel Rui

    Directory of Open Access Journals (Sweden)

    Chimica Francisco

    2017-08-01

    Full Text Available O presente artigo tem em vista a realização de um estudo em torno da categoria espaço. A abordagem centra-se na obra marcadamente emblemática de sua época no contexto da contribuição para o enriquecimento e a periodização da literatura de seu país. Trata-se da obra Quem me dera ser onda (2005, do angolano Manuel Rui. Quem me dera ser onda é uma novela que retrata a situação de uma população que, por força da Revolução, isto é, com o final da guerra colonial em 1975, procura adaptar-se à nova realidade fruto das conquistas dessa mesma Revolução. Verifica-se o movimento da população do subúrbio em direção às áreas urbanizadas de Luanda e os desafios, os choques com que se enfrenta essa nova realidade de vida. Assim, narram-se fatos ocorridos no pós-independência de Angola. Quem me dera ser onda tem como espaço fundamental a capital angolana, a grande cidade luandense que está vivendo uma experiência nova fruto das conquistas do povo, uma explosão demográfica, em um movimento unidirecional, do subúrbio para o urbano, para o desconhecido. Será adotada uma metodologia analítica e descritiva apoiada em conceitos sobre espaço a partir de teóricos como Reis e Lopes (2000; Paz e Moniz (2004; Umbelino (2011 e, sobretudo, Bourneuf e Ouellet (1976, que apresentam o espaço opressivo como sendo predominante nos romances contemporânes. Dada a confluência de eventos no espaço Luanda, acha-se importante o aprofundamento desta categoria na obra.

  19. Análise da luz circularmente polarizada produzida por um ser vivo

    OpenAIRE

    Flemming, J.; Rosa, C.A.

    2015-01-01

    Analisamos a luz refletida por um escaravelho (Phanaeus splendidulus) de cor metálica iridescente que transforma luz não polarizada em circularmente polarizada à esquerda. Animais ou plantas que produzam este tipo de luz não são comuns, apesar desta particular espécie ser bastante disseminada no Brasil. Este fato somado à relativa facilidade de obter um polarizador e uma lâmina de quarto de onda acromática permitem esta demonstração experimental e a análise da polarização circular nos laborat...

  20. Non-labeling multiplex surface enhanced Raman scattering (SERS) detection of volatile organic compounds (VOCs)

    DEFF Research Database (Denmark)

    Wong, Chi Lok; Dinish, U. S.; Schmidt, Michael Stenbæk

    2014-01-01

    of acetone and ethanol vapor was also successfully demonstrated. The vibrational fingerprints of molecular structures provide specific Raman peaks for different VOCs contents. To the best of our knowledge, this is the first multiplex VOCs detection using SERS. We believe that this work may lead to a portable......-pillars. In this experiment, detections of acetone and ethanol vapor at different concentrations were demonstrated. The detection limits were found to be 0.0017 ng and 0.0037 ng for ethanol and acetone vapor molecules respectively. Our approach is a non-labeling method such that it does not require the incorporation of any...

  1. El SERS como sensor de pH en entornos nanométricos

    OpenAIRE

    López-Tocón, Isabel

    2015-01-01

    La Espectroscopia SERS (Surface-Enhanced Raman Spectroscopy) se caracteriza por la enorme intensificación de la señal Raman de una molécula cuando se encuentra en las proximidades de una superficie metálica rugosa a escala nanométrica. Se trata, por tanto, de una técnica de alta sensibilidad que permite el registro de muestras a muy baja concentración y además, de alta selectividad, ya que únicamente aquellas moléculas que presenten un centro capaz de interaccionar con el metal, como un par ...

  2. IMPORTANCIA DE LA MUSICOTERAPIA EN EL ÁREA EMOCIONAL DEL SER HUMANO

    Directory of Open Access Journals (Sweden)

    Serafina Poch Blasco

    2001-01-01

    Full Text Available La Musicoterapia científica es una técnica terapéutica de plena actualidad, cuyo interés crece progresivamente. Las carencias en el área de la educación emocional de niños y adolescentes podrían paliarse con programas de Musicoterapia en los centros educativos, ya que la salud emocional es fundamental para el ser humano, sin la cual todo lo demás cae por su base. Se exponen dos programas: uno de Musicoterapia Preventiva y otro de Ayuda a niños de preescolar, con problemas, hijos de padres separados.

  3. Utilization of triangle nanosilver to prepare spherical nanosilver and quantitatively detect trace titanium by SERS

    OpenAIRE

    Liu, Qingye; Wen, Guiqing; Zhang, Xinghui; Liang, Aihui; Jiang, Zhiliang

    2014-01-01

    The blue triangle nanosilver (BAgNP) sol was prepared by the two reducers of NaBH4 and H2O2. Using BAgNP as the precursor, a small spherical nanosilver (AgNP) sol in yellow was synthesized by addition of suitable amounts of X ? (X?=?Cl, Br, and I). The oxidization process of BAgNP to AgNP was studied in detail by resonance Rayleigh scattering (RRS), surface-enhanced Raman scattering (SERS), laser scattering, surface plasmon resonance (SPR) absorption, and microscope techniques. It has been ob...

  4. Gold-sputtered Blu-ray discs: simple and inexpensive SERS substrates for sensitive detection of melamine.

    Science.gov (United States)

    Nieuwoudt, Michél K; Martin, Jacob W; Oosterbeek, Reece N; Novikova, Nina I; Wang, Xindi; Malmström, Jenny; Williams, David E; Simpson, M Cather

    2016-06-01

    Nanostructured gold substrates provide chemically stable, signal-enhancing substrates for the sensitive detection of a variety of compounds through surface-enhanced Raman spectroscopy (SERS). Recent developments in advanced fabrication methods have enabled the manufacture of SERS substrates with repeatable surface nanostructures that provide reproducible quantitative analysis, historically a weakness of the SERS technique. Here, we describe the novel use of gold-sputtered Blu-ray disc surfaces as SERS substrates. The unique surface features and composition of the Blu-ray disc recording surface lead to the formation of gold nano-islands and nanogaps following simple gold sputtering, without any background peaks from the substrate. The SERS performance of this substrate is strong and reproducible with an enhancement factor (EF) of 10(3) for melamine. A limit of detection (LOD) for this compound of 70 ppb and average reproducibility of ±12 % were achieved. Gold-sputtered Blu-ray discs thus offer an excellent alternative to more exotic gold SERS substrates prepared by advanced, time-consuming and expensive methods. Graphical abstract AFM 3D images of 1-μm(2) sections of uncoated and gold-sputtered recordable Blu-ray disc (BD-R) surfaces and the SERS signal obtained on the gold-sputtered surface for a 1000 ppm aqueous solution of melamine.

  5. A surface-enhanced Raman scattering (SERS-active optical fiber sensor based on a three-dimensional sensing layer

    Directory of Open Access Journals (Sweden)

    Chunyu Liu

    2014-08-01

    Full Text Available To fabricate a new surface-enhanced Raman scattering (SERS-active optical fiber sensor, the design and preparation of SERS-active sensing layer is one of important topics. In this study, we fabricated a highly sensitive three-dimensional (3D SERS-active sensing layer on the optical fiber terminal via in situ polymerizing a porous polymer material on a flat optical fiber terminal through thermal-induced process, following with the photochemical silver nanoparticles growth. The polymerized polymer formed a 3D porous structure with the pore size of 0.29–0.81 μm, which were afterward decorated with abundant silver nanoparticles with the size of about 100 nm, allowing for higher SERS enhancement. This SERS-active optical fiber sensor was applied for the determination of 4-mercaptopyridine, crystal violet and maleic acid The enhancement factor of this SERS sensing layer can be reached as about 108. The optical fiber sensor with high sensitive SERS-active porous polymer is expected for online analysis and environment detection.

  6. O significado de ser especialista para o enfermeiro estomaterapeuta El sentido de ser especialista para el enfermero estomaterapeuta The meaning of specialization for the esterostomal therapist

    Directory of Open Access Journals (Sweden)

    Maria Angela Boccara de Paula

    2003-08-01

    Full Text Available Este estudo teve como objetivo conhecer e compreender as percepções dos estomaterapeutas em relação aos significados de ser especialista, tendo como referencial metodológico a Teoria das Representações Sociais. A análise dos discursos de 12 estomaterapeutas permitiu significar três Unidades Temáticas: o estomaterapeuta como profissional, pessoa e junto ao cliente. Representações principalmente positivas como valorização, reconhecimento, remuneração, ascensão, satisfação, vontade de crescer, destaque profissional, melhoria da qualidade da assistência e segurança do cliente foram desveladas para os enfermeiros em relação à Estomaterapia. Algumas significações negativas como cobrança e falta de reconhecimento também surgiram. Essas representações indicaram a especialização como importante dimensão no percurso profissional, fato que tem influenciado positivamente o caminhar do enfermeiro em particular do estomaterapeuta. Esse constrói sua existência no tempo, escreve sua história impulsionada para a ação autônoma e com credibilidade, que permite a conquista de espaço e a resignificação do cuidar - fundamento da arte e ciência da Enfermagem.Este estudio tuvo como objetivo conocer y comprender las percepciones de los estomaterapeutas en relación con el sentido de ser especialista, tiendo como referencial metodológico la Teoría de las Representaciones Sociales. El análisis de los discursos de 12 terapistas enterostomales (ET permitió significar tres Unidades Temáticas: el TE como profesional, persona y junto al cliente. Representaciones principalmente positivas como valoración, reconocimiento, remuneración, ascensión, satisfacción, ganas de crecer, realce profesional, mejora de la calidad de la atención y seguridad del cliente, fueron desveladas por los enfermeros en relación a la Terapia Enterostomal. Algunas significaciones negativas como cobranza y falta de reconocimiento también surgieron

  7. Microconformado de Materiales Metálicos mediante Pulsos Láser en el Dominio de ns

    OpenAIRE

    Garcia Garcia, Oscar; Morales Furió, Miguel; García-Ballesteros Ramírez, Juan José; Porro González, Juan Antonio; Molpeceres Álvarez, Carlos Luis; Sanchez Perez, Angel M.; Ocaña Moreno, José Luis

    2008-01-01

    La demanda de miniaturización introducida, entre otros, por la industria de fabricación de MEMS (Micro Electro Mechanical Systems), hace necesario caracterizar y validar los procesos que emplean el láser en el microconformado de materiales metálicos a escala submilimétrica. Como alternativa al microconformado térmico, que hace uso de las deformaciones de origen térmico inducidas por la radiación láser, el microconformado mediante pulsos láser en el dominio de ns hace posible el conformado de ...

  8. Levantamiento láser y modelización de la Iglesia de San Martín (Segovia)

    OpenAIRE

    Gorrotxategi Elosegi, Mireia

    2013-01-01

    Se ha realizado el levantamiento mediante láser escáner 3D y el modelado de la iglesia de San Martín, en el casco viejo de Segovia, así como el levantamiento láser de un recorrido por las calles cercanas al mismo. Las fases de trabajo que conforman el proyecto son las siguientes: 1- Toma de datos en campo 2- Edición de los datos de campo 3- Obtención de productos derivados. La primera de ellas consiste en realizar el levantamiento láser de la Iglesia de San Martín, sus alred...

  9. Sintomatologia da depress?o e representa??es sociais de ser idoso e depress?o

    OpenAIRE

    Oliveira, Marcos Francisco de

    2011-01-01

    Introdu??o: O envelhecimento, apesar de ser uma grande vit?ria, est? causando uma ampla preocupa??o para os governantes, devido ao aumento populacional e ao risco de adoecimento, capaz de afetar a qualidade de vida das pessoas idosas. Objetivos: Avaliar a sintomatologia da depress?o referida por idosos; conhecer as representa??es sociais sobre ser idoso e depress?o; e identificar aspectos psicossociais associados a ser idoso e depress?o. Metodologia: Estudo explorat?rio, realiz...

  10. Controlled Growth of Gold Nanostars: Effect of Spike Length on SERS Signal Enhancement.

    Science.gov (United States)

    Sheen Mers, S V; Umadevi, S; Ganesh, V

    2017-05-19

    Two different types of gold nanostars (Au NS), namely, short-spiked nanostars (SSNS) and long-spiked nanostars (LSNS), are prepared by using a hexagonal lyotropic liquid-crystalline (LLC) phase as a template. The formation, size and length of spikes or arms of the resultant Au NS are controlled by preparation in either a hexagonal LLC phase or an isotropic phase. These NS are anchored onto indium tin oxide (ITO) electrodes through a self-assembled monolayer of 3-mercaptopropyltrimethoxysilane, which acts as a linker molecule. Structural and morphological characterisations of SSNS- and LSNS-anchored ITO electrodes are performed by means of microscopic and spectroscopic analyses. Further electrochemical techniques, namely, cyclic voltammetry and electrochemical impedance spectroscopy, are also used to confirm the immobilisation of these Au NS on ITO electrodes and to study the electrochemical characteristics. These studies clearly reveal the formation of star-shaped, branched, anisotropic nanostructures of gold during the template preparation method and these Au NS are successfully anchored onto ITO electrodes through a covalent immobilisation strategy. Furthermore, the SERS activity of these Au NS is analysed by using glutathione and crystal violet as analytes and by employing glass and ITO as substrates. It is interesting to note that SSNS show a significant enhancement in SERS signals relative to those of LSNS. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Monitoring cell culture media degradation using surface enhanced Raman scattering (SERS) spectroscopy.

    Science.gov (United States)

    Calvet, Amandine; Ryder, Alan G

    2014-08-20

    The quality of the cell culture media used in biopharmaceutical manufacturing is a crucial factor affecting bioprocess performance and the quality of the final product. Due to their complex composition these media are inherently unstable, and significant compositional variations can occur particularly when in the prepared liquid state. For example photo-degradation of cell culture media can have adverse effects on cell viability and thus process performance. There is therefore, from quality control, quality assurance and process management view points, an urgent demand for the development of rapid and inexpensive tools for the stability monitoring of these complex mixtures. Spectroscopic methods, based on fluorescence or Raman measurements, have now become viable alternatives to more time-consuming and expensive (on a unit analysis cost) chromatographic and/or mass spectrometry based methods for routine analysis of media. Here we demonstrate the application of surface enhanced Raman scattering (SERS) spectroscopy for the simple, fast, analysis of cell culture media degradation. Once stringent reproducibility controls are implemented, chemometric data analysis methods can then be used to rapidly monitor the compositional changes in chemically defined media. SERS shows clearly that even when media are stored at low temperature (2-8°C) and in the dark, significant chemical changes occur, particularly with regard to cysteine/cystine concentration. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Controllable Charge Transfer in Ag-TiO2 Composite Structure for SERS Application

    Directory of Open Access Journals (Sweden)

    Yaxin Wang

    2017-06-01

    Full Text Available The nanocaps array of TiO2/Ag bilayer with different Ag thicknesses and co-sputtering TiO2-Ag monolayer with different TiO2 contents were fabricated on a two-dimensional colloidal array substrate for the investigation of Surface enhanced Raman scattering (SERS properties. For the TiO2/Ag bilayer, when the Ag thickness increased, SERS intensity decreased. Meanwhile, a significant enhancement was observed when the sublayer Ag was 10 nm compared to the pure Ag monolayer, which was ascribed to the metal-semiconductor synergistic effect that electromagnetic mechanism (EM provided by roughness surface and charge-transfer (CT enhancement mechanism from TiO2-Ag composite components. In comparison to the TiO2/Ag bilayer, the co-sputtered TiO2-Ag monolayer decreased the aggregation of Ag particles and led to the formation of small Ag particles, which showed that TiO2 could effectively inhibit the aggregation and growth of Ag nanoparticles.

  13. Privadesa a Internet i el dret a ser oblidat/dret a l'oblit

    Directory of Open Access Journals (Sweden)

    Cécile de Terwangne

    2012-03-01

    Full Text Available El dret a l'oblit, també anomenat dret a ser oblidat, és el dret de les persones físiques a fer que s'esborri la informació sobre elles després d'un període de temps determinat. Internet ha comportat la necessitat d'un nou equilibri entre la lliure difusió de la informació i l'autodeterminació individual. Aquest equilibri és precisament el que està en joc amb el dret a l'oblit. Aquest dret presenta tres facetes: el dret a l'oblit del passat judicial, el dret a l'oblit establert per la legislació de protecció de dades i un nou dret digital i encara polèmic a l'oblit, que equivaldria a l'atribució d'una data de caducitat a les dades personals o que hauria de ser aplicable en el context específic de les xarxes socials. Aquest treball analitza cadascuna d'aquestes facetes en l'entorn d'Internet.

  14. Instant synthesis of gold nanoparticles at room temperature and SERS applications

    International Nuclear Information System (INIS)

    Britto Hurtado, R.; Cortez-Valadez, M.; Ramírez-Rodríguez, L.P.; Larios-Rodriguez, Eduardo; Alvarez, Ramón A.B.; Rocha-Rocha, O.; Delgado-Beleño, Y.; Martinez-Nuñez, C.E.; Arizpe-Chávez, H.; Hernández-Martínez, A.R.; Flores-Acosta, M.

    2016-01-01

    Nowadays, gold nanoparticles (AuNps) can be used in a variety of applications, thus efficient methods to produce them are necessary. Several methods have been proposed in this area, but NPs production time is one limitation of these approaches. In this study, we propose a high competitive method to synthesize gold colloidal nanoparticles, instantaneously, using no-toxic reducing agents. These substances allow the instantaneous synthesis at room temperature, even without magnetic stirrers, ovens or ultrasonic baths. Optic analysis showed two absorption bands, associated with surface Plasmon as function of HAuCl 4 concentration. The nanoparticles synthesized have a 10–20 nm size, seen by the transmission electron microscopy (TEM). Therefore, it was possible to obtain several geometric patterns of AuNps, and the synthesis was performed reducing significantly processing time. Additionally, Mie and Fuchs theories were used to predict the location of the absorption bands linked to the plasmon surface in gold nanoparticles. The Surface Enhanced Raman Spectroscopy (SERS) effect was analyzed considering natural zeolite (Chabazite) as analyte, in order to determinate its possible application in soil analysis. - Highlights: • Cubic and spherical morphologies in AuNp. • Surface plasmon prediction in cubic and spherical AuNp. • Instant synthesis of AuNp. • SERS applications in soil analysis.

  15. Telmisartan activates endothelial nitric oxide synthase via Ser1177 phosphorylation in vascular endothelial cells.

    Directory of Open Access Journals (Sweden)

    Masahiro Myojo

    Full Text Available Because endothelial nitric oxide synthase (eNOS has anti-inflammatory and anti-arteriosclerotic functions, it has been recognized as one of the key molecules essential for the homeostatic control of blood vessels other than relaxation of vascular tone. Here, we examined whether telmisartan modulates eNOS function through its pleiotropic effect. Administration of telmisartan to mice significantly increased the phosphorylation level of eNOS (Ser1177 in the aortic endothelium, but administration of valsartan had no effect. Similarly, telmisartan treatment of human umbilical vein endothelial cells significantly increased the phosphorylation levels of AMP-activated protein kinase (Thr172 and eNOS and the concentration of intracellular guanosine 3',5'-cyclic monophosphate (cGMP. Furthermore, pretreatment with a p38 mitogen-activated protein kinase (p38 MAPK inhibitor suppressed the increased phosphorylation level of eNOS and intracellular cGMP concentration. These data show that telmisartan increases eNOS activity through Ser1177 phosphorylation in vascular endothelial cells mainly via p38 MAPK signaling.

  16. Toward understanding the influence of intermolecular interactions and molecular orientation on the chemical enhancement of SERS.

    Science.gov (United States)

    Cabalo, Jerry; Guicheteau, Jason A; Christesen, Steven

    2013-09-19

    Implementation of SERS as an analytical technique is limited because the factors that govern the enhancement of individual vibrational modes are not well understood. Although the chemical effect only accounts for up to two orders of magnitude enhancement, it can still have a significant impact on the consistency of chemical spectral signatures. We report on a combined theoretical and experimental study on the benzenethiol on silver and 4-mercaptophenol on silver systems. The primary and unique finding was that for the benzenethiol on silver system the inclusion of interaction between multiple benzenethiol analyte molecules was essential to account for the relative enhancements observed experimentally. An examination of the molecular orbitals showed sharing of electron density across the entire model of multiple benzenethiol molecules mediated by the metal atoms. The addition of multiple 4-mercaptophenol molecules to the theoretical model had little effect on the predicted spectra, and we attribute this to the fact that a much larger model is necessary to replicate the networks of hydrogen bonds. Molecular orientation was also found to affect the predicted spectra, and it was found that an upright position improved agreement between theoretical and experimental spectra. An analysis of the vibrational frequency shifts between the normal Raman spectrum of the neat compound and the SERS spectrum also suggests that both benzenethiol and 4-mercaptophenol are in an upright position.

  17. Graphene oxide on magnetron sputtered silver thin films for SERS and metamaterial applications

    Science.gov (United States)

    Politano, Grazia Giuseppina; Cazzanelli, Enzo; Versace, Carlo; Vena, Carlo; De Santo, Maria Penelope; Castriota, Marco; Ciuchi, Federica; Bartolino, Roberto

    2018-01-01

    In the last years the potential of combining the attractive materials characteristics of graphene related materials and silver nanostructures for SERS and metamaterials has emerged. Here, we report of graphene oxide thin films deposited by dip-coating on magnetron sputtered silver thin films. Our work represents a novelty in the field of the study of graphene oxide- silver composites, since magnetron sputtering deposition is an alternative way to silver thin films fabrication; previous works used instead silver nitrate aqueous solution mixed with the graphene oxide. Micro-Raman technique, morphological analysis and variable angle spectroscopic ellipsometry were performed. The final SERS signal intensity was investigated and we found Raman peaks dependent on the intensity of the laser and the thickness of silver and GO films. These results could open somestudies on plasmonics and on the reduction of graphene oxide mediated by silver thin films. Moreover, effective medium theory calculations show the possible use of these graphene oxide/silver thin films in multilayer hyperbolic metamaterials for optical applications.

  18. Instant synthesis of gold nanoparticles at room temperature and SERS applications

    Energy Technology Data Exchange (ETDEWEB)

    Britto Hurtado, R. [Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal 5-88, 83190, Hermosillo, Sonora (Mexico); Cortez-Valadez, M., E-mail: jose.cortez@unison.mx [CONACYT-Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal 5-88, 83190, Hermosillo, Sonora (Mexico); Ramírez-Rodríguez, L.P. [Departamento de Física, Universidad de Sonora, Apdo. Postal 5-88, 83190, Hermosillo, Sonora (Mexico); Larios-Rodriguez, Eduardo [Departamento de Ingeniería Química y Metalurgia, Universidad de Sonora, Rosales y Luis Encinas S/N, Hermosillo, Sonora (Mexico); Alvarez, Ramón A.B.; Rocha-Rocha, O.; Delgado-Beleño, Y.; Martinez-Nuñez, C.E.; Arizpe-Chávez, H. [Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal 5-88, 83190, Hermosillo, Sonora (Mexico); Hernández-Martínez, A.R. [Centro de Física Aplicada y Tecnología Avanzada (CFATA), Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro C.P. 76130 (Mexico); Flores-Acosta, M. [Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal 5-88, 83190, Hermosillo, Sonora (Mexico)

    2016-08-06

    Nowadays, gold nanoparticles (AuNps) can be used in a variety of applications, thus efficient methods to produce them are necessary. Several methods have been proposed in this area, but NPs production time is one limitation of these approaches. In this study, we propose a high competitive method to synthesize gold colloidal nanoparticles, instantaneously, using no-toxic reducing agents. These substances allow the instantaneous synthesis at room temperature, even without magnetic stirrers, ovens or ultrasonic baths. Optic analysis showed two absorption bands, associated with surface Plasmon as function of HAuCl{sub 4} concentration. The nanoparticles synthesized have a 10–20 nm size, seen by the transmission electron microscopy (TEM). Therefore, it was possible to obtain several geometric patterns of AuNps, and the synthesis was performed reducing significantly processing time. Additionally, Mie and Fuchs theories were used to predict the location of the absorption bands linked to the plasmon surface in gold nanoparticles. The Surface Enhanced Raman Spectroscopy (SERS) effect was analyzed considering natural zeolite (Chabazite) as analyte, in order to determinate its possible application in soil analysis. - Highlights: • Cubic and spherical morphologies in AuNp. • Surface plasmon prediction in cubic and spherical AuNp. • Instant synthesis of AuNp. • SERS applications in soil analysis.

  19. OUTRAS FACES DO SER INDÍGENA: ENTRE PERTENCIMENTOS E EXCLUSÕES

    Directory of Open Access Journals (Sweden)

    Assis da Costa Oliveira

    2009-12-01

    Full Text Available O presente artigo analisa a lógica da ins/constituição identitária e percepção sobre ações afirmativas de 19 estudantes universitários autodeclarados indígenas vinculados a Universidade Federal do Pará. Este “outro” pertencimento étnico configura-se numa afirmação variada do ser indígena condicionada a aspectos genealógicos, simbólicos e territoriais, com reflexos no referencial demográfico indígena no Brasil e nas condições político-antropológicas de reconhecimento identitário. A passagem do eixo da identidade para a dos direitos indígenas, mediada pela questão das ações afirmativas, revelou efeitos na consideração do ser indígena pelo ingresso na relação de alteridade com o “outro” contemplado pelas cotas, de tal modo complexa que torna a ligação entre ins/constituição identitária e ações afirmativas uma necessidade acessória, condicionada a aspectos sociopolíticos.

  20. LOS SIGNIFICADOS DE SER HOMBRE ASOCIADOS AL CONSUMO DE SUSTANCIAS PSICOACTIVAS

    Directory of Open Access Journals (Sweden)

    MARCO ANTONIO TOQUERO HERNÁNDEZ

    2013-01-01

    Full Text Available e l estudio del uso de sustancias psicoactivas ( spa , desde el construc - cionismo social, implica comprender cómo se articulan los conceptos y las prácticas. e l objetivo del presente trabajo fue conocer los signifi - cados de ser hombre, en un usuario de spa . s e empleó una metodo - logía cualitativa, a través de la historia de vida, se realizó un análisis narrativo en cuatro ejes: i c onsumo de spa en la familia y entorno; ii v ida emocional; iii c ontexto de pares y i V r elación con la figura femenina. l os resultados muestran que el uso de spa en la familia y entorno es una práctica que se “naturaliza” en la vida cotidiana; en la vida emocional, es un medio para evitar el sentimiento de vulne - rabilidad como hombres; en la relación con los pares es un recurso para obtener reconocimiento; y con la figura femenina representa un medio de control. d esde una perspectiva de género, el uso de spa significa ser hombre, asumir el control y poder.

  1. Emergence of two near-infrared windows for in vivo and intraoperative SERS.

    Science.gov (United States)

    Lane, Lucas A; Xue, Ruiyang; Nie, Shuming

    2018-04-06

    Two clear windows in the near-infrared (NIR) spectrum are of considerable current interest for in vivo molecular imaging and spectroscopic detection. The main rationale is that near-infrared light can penetrate biological tissues such as skin and blood more efficiently than visible light because these tissues scatter and absorb less light at longer wavelengths. The first clear window, defined as light wavelengths between 650nm and 950nm, has been shown to be far superior for in vivo and intraoperative optical imaging than visible light. The second clear window, operating in the wavelength range of 1000-1700nm, has been reported to further improve detection sensitivity, spatial resolution, and tissue penetration because tissue photon scattering and background interference are further reduced at longer wavelengths. Here we discuss recent advances in developing biocompatible plasmonic nanoparticles for in vivo and intraoperative surface-enhanced Raman scattering (SERS) in both the first and second NIR windows. In particular, a new class of 'broad-band' plasmonic nanostructures is well suited for surface Raman enhancement across a broad range of wavelengths allowing a direct comparison of detection sensitivity and tissue penetration between the two NIR window. Also, optimized and encoded SERS nanoparticles are generally nontoxic and are much brighter than near-infrared quantum dots (QDs), raising new possibilities for ultrasensitive detection of microscopic tumors and image-guided precision surgery. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. In situ detection and identification of hair dyes using surface-enhanced Raman spectroscopy (SERS).

    Science.gov (United States)

    Kurouski, Dmitry; Van Duyne, Richard P

    2015-03-03

    Hair is one of the most common types of physical evidence found at a crime scene. Forensic examination may suggest a connection between a suspect and a crime scene or victim, or it may demonstrate an absence of such associations. Therefore, forensic analysis of hair evidence is invaluable to criminal investigations. Current hair forensic examinations are primarily based on a subjective microscopic comparison of hair found at the crime scene with a sample of suspect's hair. Since this is often inconclusive, the development of alternative and more-accurate hair analysis techniques is critical. In this study, we utilized surface-enhanced Raman spectroscopy (SERS) to demonstrate that artificial dyes can be directly detected on hair. This spectroscopic technique is capable of a confirmatory identification of analytes with single molecule resolution, requires minimal sample, and has the advantage of fluorescence quenching. Our study reveals that SERS can (1) identify whether hair was artificially dyed or not, (2) determine if a permanent or semipermanent colorants were used, and (3) distinguish the commercial brands that are utilized to dye hair. Such analysis is rapid, minimally destructive, and can be performed directly at the crime scene. This study provides a novel perspective of forensic investigations of hair evidence.

  3. Phosphorylation of DEPDC1 at Ser110 is required to maintain centrosome organization during mitosis.

    Science.gov (United States)

    Chen, Dan; Ito, Satoko; Hyodo, Toshinori; Asano-Inami, Eri; Yuan, Hong; Senga, Takeshi

    2017-09-15

    DEPDC1 (DEP domain containing 1) is overexpressed in multiple cancers and is associated with cell cycle progression. In this report, we have investigated the expression, localization, phosphorylation and function of DEPDC1 during mitosis. DEPDC1 has two isoforms (isoform a and isoform b), and both of them are increased in mitosis and degraded once cells exit mitosis. DEPDC1a is localized to the centrosome in metaphase, whereas DEPDC1b is localized to the entire cell cortex during mitosis. DEPDC1a, but not DEPDC1b, was required for the integrity of centrosome and organization of the bipolar spindle. Mass spectrometry and biochemical analyses revealed phosphorylation of DEPDC1 at Ser110. The phosphorylation of Ser110 is essential for localization of DEPDC1a to the centrosome. Consistently, non-phosphorylation mutants of DEPDC1a did not rescue disruption of centrosome organization by depletion of endogenous DEPDC1. Our results show a novel role for DEPDC1 in maintaining centrosome integrity during mitosis for the accurate distribution of chromosomes. Copyright © 2017. Published by Elsevier Inc.

  4. SERS activity of silver and gold nanostructured thin films deposited by pulsed laser ablation

    Science.gov (United States)

    Agarwal, N. R.; Tommasini, M.; Fazio, E.; Neri, F.; Ponterio, R. C.; Trusso, S.; Ossi, P. M.

    2014-10-01

    Nanostructured Au and Ag thin films were obtained by nanosecond pulsed laser ablation in presence of a controlled Ar atmosphere. Keeping constant other deposition parameters such as target-to-substrate distance, incidence angle, laser wavelength and laser fluence, the film morphology, revealed by SEM, ranges from isolated NPs to island structures and sensibly depends on gas pressure (10-100 Pa) and on the laser pulse number (500-3 × 10). The control of these two parameters allows tailoring the morphology and correspondingly the optical properties of the films. The position and width of the surface plasmon resonance peak, in fact, can be varied with continuity. The films showed remarkable surface-enhanced Raman activity (SERS) that depends on the adopted deposition conditions. Raman maps were acquired on micrometer-sized areas of both silver and gold substrates selected among those with the strongest SERS activity. Organic dyes of interest in cultural heritage studies (alizarin, purpurin) have been also considered for bench marking the substrates produced in this work. Also the ability to detect the presence of biomolecules was tested using lysozyme in a label free configuration.

  5. Selective Growth and SERS Property of Gold Nanoparticles on Amorphized Silicon Surface

    International Nuclear Information System (INIS)

    Matsuoka, T; Nishi, M; Sakakura, M; Shimotsuma, Y; Miura, K; Hirao, K

    2011-01-01

    We have fabricated gold patterns on a silicon substrate by a simple three-step method using a focused ion beam (FIB). The obtained gold patterns consisted of a large number of gold nanoparticles which grew selectively on the preprocessed silicon surface from an Au ion-containing solution dropped on the substrate. The solution was prepared by reacting HAuCl 4 aqueous solution with (3-mercaptopropyl)trimethoxysilane (MPTMS). It was found that the size and shape of the precipitating gold nanoparticles is controllable by changing the mixing ratio between HAuCl 4 aqueous solution and MPTMS. Additionally, we confirmed that the fabricated gold structures were surface enhanced Raman scattering (SERS)-active; the enhanced Raman peaks of rhodamin 6G (R6G) were detected on the fabricated gold structures, whereas no peak was detected on the alternative silicon surface. We also demonstrated the gold patterning using a femtosecond laser instead of an FIB. We believe that our method is a favorable candidate for fabricating SERS-active substrates, since the substrates can be prepared very simply and flexibly.

  6. Laser treatment of Ag@ZnO nanorods as long-life-span SERS surfaces.

    Science.gov (United States)

    Macias-Montero, Manuel; Peláez, Ramón J; Rico, Victor J; Saghi, Zineb; Midgley, Paul; Afonso, Carmen N; González-Elipe, Agustín R; Borras, Ana

    2015-02-04

    UV nanosecond laser pulses have been used to produce a unique surface nanostructuration of Ag@ZnO supported nanorods (NRs). The NRs were fabricated by plasma enhanced chemical vapor deposition (PECVD) at low temperature applying a silver layer as promoter. The irradiation of these structures with single nanosecond pulses of an ArF laser produces the melting and reshaping of the end of the NRs that aggregate in the form of bundles terminated by melted ZnO spherical particles. Well-defined silver nanoparticles (NPs), formed by phase separation at the surface of these melted ZnO particles, give rise to a broad plasmonic response consistent with their anisotropic shape. Surface enhanced Raman scattering (SERS) in the as-prepared Ag@ZnO NRs arrays was proved by using a Rhodamine 6G (Rh6G) chromophore as standard analyte. The surface modifications induced by laser treatment improve the stability of this system as SERS substrate while preserving its activity.

  7. Control de procesos de temple con láser mediante dispositivos pirométricos

    Directory of Open Access Journals (Sweden)

    Molpeceres, C.

    2002-06-01

    Full Text Available In this work, a detailed description of an on-line control system for laser heat treatments based on pyrometric monitorization, is presented. The study includes full details concerning monitorization devices and comprehensive description of the control loop, based on a direct synthesis regulator. The system validation and exportable character of the proposed method are also discussed. Finally, results obtained for CO2 laser transformation hardening of F-114 steel are analyzed, including parametric analysis of control variables through metallurgical testing of the treated material.

    Se presenta un sistema de regulación en tiempo real del temple de aceros con láser basado en el empleo de dispositivos pirométricos de radiación. Se incluye una descripción completa del dispositivo de monitorización junto con un análisis detallado del bucle de control, basado en un regulador por síntesis directa y su validación, especificando su concepción flexible y exportable a otro tipo de sistemas y tratamientos láser diferentes al empleado en el presente trabajo. Finalmente, se analizan los resultados obtenidos aplicando el sistema en procesos reales de temple superficial en acero F-114, incluyendo un estudio paramétrico de las posibles variables de control a través de ensayos de dureza y profundidad de temple de las probetas tratadas.

  8. O significado de ser familiar cuidador do portador de transtorno mental

    Directory of Open Access Journals (Sweden)

    Marília Mazzuco Sant'Ana

    2011-01-01

    Full Text Available Este es un estudio cualitativo de enfoque exploratorio, descriptivo, cuyo objetivo fue comprender el significado de ser un cuidador familiar de pacientes con trastornos mentales. El estudio se desarrolló con los familiares de los pacientes con trastornos mentales, seguido en la clinica integrada de Atención Primaria de Salud en el municipio de Biguaçu-SC, vinculada a Universidade do Vale do Itajaí. Los datos cualitativos fueron obtenidos por entrevista dialógica y analizados sobre la base de la teoría del Devenir Humano. Del análisis de los dados surgieron las siguientes categorías: la experiencia de trastorno mental en las familias; hacer frente a las dificultades y limitaciones, la interrelación con la familia y "otros"; y co-creación de las posibilidades de trascendencia. Se concluyó que viver la teoría del Devenir Humano con el familiar cuidador de pacientes con trastorno mental, implica la co-participación del enfermero en la iluminación de los significados de las situaciones vivenciadas, co-trasciendendo sus propias condiciones de ser y actuar en el mundo en busca de una mejor calidad de vida.

  9. Mixing thiols on the surface of silver nanoparticles: preserving antibacterial properties while introducing SERS activity

    Energy Technology Data Exchange (ETDEWEB)

    Taglietti, Angelo, E-mail: angelo.taglietti@unipv.it [Università di Pavia, Dipartimento di Chimica (Italy); Diaz Fernandez, Yuri A. [Chalmers University of Technology, Department of Chemical and Biological Engineering (Sweden); Galinetto, Pietro [Università di Pavia, Dipartimento di Fisica (Italy); Grisoli, Pietro [Università di Pavia, Dipartimento di Scienze del Farmaco (Italy); Milanese, Chiara; Pallavicini, Piersandro [Università di Pavia, Dipartimento di Chimica (Italy)

    2013-11-15

    Controlling the surface composition of self-assembled monolayers is one of the major experimental challenges in nanotechnology. Despite the significant interest of the scientific community and the considerable number of publications related to this topic, the potential in this field is still far from being fully exploited.We present in this study a versatile method to coat silver nanoparticles (AgNPs) having average diameter of 7 nm with mixed monolayers of two thiols, achieving a precise control of surface composition. Different combinations of thiols have been investigated, and the nanomaterials obtained have been characterized by complementary experimental techniques, addressing the composition of the mixed monolayer. The surface-enhanced Raman spectroscopy (SERS) effect on a Raman reporter (7-mercapto-4-methylcoumarine) introduced into the mixed monolayers has also been investigated. The antibacterial activity of the coated AgNPs was investigated, showing that the colloids were active against Escherichia coli and Staphilococcus aureus irrespective of the nature of the mixed monolayer. These materials are good candidates as SERS-tags for biological applications.

  10. A experiencia de ser surdo: uma descrição fenomenológica

    Directory of Open Access Journals (Sweden)

    Rodrigo Rosso Marques

    2016-04-01

    Full Text Available A presente tese expoe uma pesquisa ontologica sobre o Ser Surdo, fundamentada no corpo proprio; uma reflexao sobre as pessoas surdas antes de destacar seus aspectos culturais. O que leva essas pessoas a produzir estes aspectos? Seria apenas uma necessidade linguistica? Objetivando repensar a questao da deficiencia e da cultura, a fundamentacao parte de uma premissa fenomenologica nos estudos de Maurice Merleau-Ponty; em particular, da sua obra Fenomenologia da Percepcao, a qual aborda a questao do corpo proprio. A tese foi desenvolvida com base na experiencia da surdez do proprio autor, uma vez que, atuando como ator e autor da experiencia em diversos campos, vivenciou a transicao para a surdez, o desespero e aceitacao da familia, o cotidiano escolar na infancia, na adolescencia, na juventude e maturidade, e nos diversos niveis de ensino ate a conclusao desta pesquisa. Desenvolvido sob o método descritivo, a abordagem fenomenologica induz a uma analise do corpo enquanto agente essencial das atitudes que descrevem a pessoa surda; atitudes essas, tomadas por um grupo de pessoas surdas, evidenciam a chamada “cultura surda”. Como resultado, evidenciaram-se caracteristicas corporais e perceptuais que sao especificas das pessoas surdas, constituindo-lhes a essencia de ser e contrapondo a questao da deficiencia. Nao obstante, a pesquisa ainda apresenta novas formas de repensar os estudos sobre as pessoas surdas, naquilo que sempre foi rejeitado como uma possibilidade a elas: o som.

  11. Exonuclease III-boosted cascade reactions for ultrasensitive SERS detection of nucleic acids.

    Science.gov (United States)

    Sun, Yudie; Peng, Pai; Guo, Ruiyan; Wang, Huihui; Li, Tao

    2018-05-01

    A variety of nucleic acid amplification techniques have been integrated into different detection methods to promote the development of sensitive and convenient analysis of nucleic acids. However, it is still in urgent need to develop amplified nucleic acid biosensors for the analysis of susceptible gene and even distinguishing single-base mismatched DNA in complex biological samples. Benefiting from the achieved detection strategies, here we boost isothermal nucleic acid amplification by resorting to enzyme amplification, and combine this two-stage amplification method with surface-enhanced Raman spectroscopy (SERS) to develop a signal-on nucleic acid detection platform. Due to the high cleavage efficiency of Exonuclease III (Exo III), a large amount of trigger DNA are produced to initiate multiple hybridization chain reaction circles. The product structure tagged with Tamra is then anchored onto the plasmonic SERS substrate and meanwhile enriched. It is demonstrated that this detection platform is sensitive toward the myocardial infarction disease related gene. A detection limit of 1 fM for the gene analysis in a linear relationship in the wide range from 1 fM to 10nM is achieved, better than most of previous counterparts. Meanwhile, our developed detection platform exhibits a high selectivity for the target gene over mismatched analogues. Our strategy provides a robust tool for signal amplification of gene detection even in blood samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Phenomenological features of dreams: Results from dream log studies using the Subjective Experiences Rating Scale (SERS).

    Science.gov (United States)

    Kahan, Tracey L; Claudatos, Stephanie

    2016-04-01

    Self-ratings of dream experiences were obtained from 144 college women for 788 dreams, using the Subjective Experiences Rating Scale (SERS). Consistent with past studies, dreams were characterized by a greater prevalence of vision, audition, and movement than smell, touch, or taste, by both positive and negative emotion, and by a range of cognitive processes. A Principal Components Analysis of SERS ratings revealed ten subscales: four sensory, three affective, one cognitive, and two structural (events/actions, locations). Correlations (Pearson r) among subscale means showed a stronger relationship among the process-oriented features (sensory, cognitive, affective) than between the process-oriented and content-centered (structural) features--a pattern predicted from past research (e.g., Bulkeley & Kahan, 2008). Notably, cognition and positive emotion were associated with a greater number of other phenomenal features than was negative emotion; these findings are consistent with studies of the qualitative features of waking autobiographical memory (e.g., Fredrickson, 2001). Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Determination of acetylsalicylic acid in commercial tablets by SERS using silver nanoparticle-coated filter paper

    Science.gov (United States)

    Sallum, Loriz Francisco; Soares, Frederico Luis Felipe; Ardila, Jorge Armando; Carneiro, Renato Lajarim

    2014-12-01

    In this work, filter paper was used as a low cost substrate for silver nanoparticles in order to perform the detection and quantification of acetylsalicylic acid by SERS in a commercial tablet. The reaction conditions were 150 mM of ammonium hydroxide, 50 mM of silver nitrate, 500 mM of glucose, 12 min of the reaction time, 45 °C temperature, pretreatment with ammonium hydroxide and quantitative filter paper (1-2 μm). The average size of silver nanoparticles deposited on the paper substrate was 180 nm. Adsorption time of acetylsalicylic acid on the surface of the silver-coated filter paper was studied and an adsorption time of 80 min was used to build the analytical curve. It was possible to obtain a calibration curve with good precision with a coefficient of determination of 0.933. The method proposed in this work was capable to quantify acetylsalicylic acid in commercial tablets, at low concentration levels, with relative error of 2.06% compared to the HPLC. The preparation of filter paper coated with silver nanoparticles using Tollen's reagent presents several advantages such as low cost of synthesis, support and reagents; minimum amount of residuals, which are easily treated, despite the SERS spectroscopy presenting fast analysis, with low sample preparation and low amount of reactants as in HPLC analysis.

  14. Stacking faults enriched silver nanowires: facile synthesis, catalysis and SERS investigations.

    Science.gov (United States)

    Xu, Minmin; Yang, Fengzhu; Yuan, Yaxian; Guo, Qinghua; Ren, Bin; Yao, Jianlin; Gu, Renao

    2013-10-01

    A facile approach based on seed-mediated method for synthesis of stacking faults enriched Ag nanowires (SFEANWs) was successfully developed. SFEANWs were formed and attached onto the seed (α-Fe2O3/Au) surfaces through the reduction of AgNO3 by ascorbic acid (AA) in the presence of sodium polyacrylate (PAANa). Their length can be tuned with different concentrations of AgNO3 or PAANa. According to the effects of seeds and PAANa, the plausible growth mechanism of SFEANWs was discussed. The catalytic activity of SFEANWs comparing with fivefold twinned Ag nanowires (FFTANWs) was evaluated through reducing p-nitrophenol by NaBH4. The activation energy of the classical reaction catalyzed by SFEANWs was calculated through the Arrhenius equation. In addition, these SFEANWs exhibited excellent surface enhanced Raman scattering (SERS) activities due to the hot spots located in the cross of the twist wires. The detection limit of by SERS for 1,4-benzenedithiol (1,4-BDT) was estimated about 10(-7) mol/L. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Starting points for the reference path in the evaluation of the SER Energy Agreement for Sustainable Growth; Uitgangspunten voor het referentiepad bij de evaluatie van het SER-energieakkoord

    Energy Technology Data Exchange (ETDEWEB)

    Koelemeijer, R.; Verdonk, M. [Planbureau voor de Leefomgeving PBL, Den Haag (Netherlands); Van Dril, T.; Seebregts, A. [ECN Beleidsstudies, Amsterdam (Netherlands)

    2013-09-01

    The effect of the measures from the SER (Social and Economic Council of the Netherlands) energy agreement on energy, renewable energy and greenhouse gas emissions is assessed by ECN and PBL in relation to the so-called SER-reference path. This paper provides an overview of the assumptions for this reference path with regard to policy, macro-economic development, demography and energy prices and the CO2 price and gives the effect on the price for electricity [Dutch] Het effect van de maatregelen uit het SER-energieakkoord op energiegebruik, hernieuwbare energie en broeikasgasemissies is door ECN en PBL geraamd ten opzichte van het z.g. SER-referentiepad. Deze notitie geeft een overzicht van de gehanteerde uitgangspunten voor dit referentiepad ten aanzien van beleid, macro-economische groei, demografie en energie- en de CO2-prijs en geeft het effect daarvan op de elektriciteitsprijs.

  16. A Toolkit For CryoSat Investigations By The ESRIN EOP-SER Altimetry Team

    Science.gov (United States)

    Dinardo, Salvatore; Bruno, Lucas; Benveniste, Jerome

    2013-12-01

    The scope of this work is to feature the new tool for the exploitation of the CryoSat data, designed and developed entirely by the Altimetry Team at ESRIN EOP-SER (Earth Observation - Exploitation, Research and Development). The tool framework is composed of two separate components: the first one handles the data collection and management, the second one is the processing toolkit. The CryoSat FBR (Full Bit Rate) data is downlinked uncompressed from the satellite, containing un-averaged individual echoes. This data is made available in the Kiruna CalVal server in a 10 day rolling archive. Daily at ESRIN all the CryoSat FBR data, in SAR and SARin Mode, are downloaded (around 30 Gigabytes) catalogued and archived in local ESRIN EOP-SER workstations. As of March 2013, the total amount of FBR data is over 9 Terabytes, with CryoSat acquisition dates spanning January 2011 to February 2013 (with some gaps). This archive was built by merging partial datasets available at ESTEC and NOAA, that have been kindly made available for EOP-SER team. The on-demand access to this low level data is restricted to expert users with validated ESA P.I. credentials. Currently the main users of the archiving functionality are the team members of the Project CP4O (STSE- CryoSat Plus for Ocean), CNES and NOAA. The second component of the service is the processing toolkit. On the EOP-SER workstations there is internally and independently developed software that is able to process the FBR data in SAR/SARin mode to generate multi-looked echoes (Level 1B) and subsequently able to re-track them in SAR and SARin mode (Level 2) over open ocean, exploiting the SAMOSA model and other internally developed models. The processing segment is used for research & development scopes, supporting the development contracts awarded confronting the deliverables to ESA, on site demonstrations/training to selected users, cross- comparison against third part products (CLS/CNES CPP Products for instance), preparation

  17. Sensory experience ratings (SERs) for 1,659 French words: Relationships with other psycholinguistic variables and visual word recognition.

    Science.gov (United States)

    Bonin, Patrick; Méot, Alain; Ferrand, Ludovic; Bugaïska, Aurélia

    2015-09-01

    We collected sensory experience ratings (SERs) for 1,659 French words in adults. Sensory experience for words is a recently introduced variable that corresponds to the degree to which words elicit sensory and perceptual experiences (Juhasz & Yap Behavior Research Methods, 45, 160-168, 2013; Juhasz, Yap, Dicke, Taylor, & Gullick Quarterly Journal of Experimental Psychology, 64, 1683-1691, 2011). The relationships of the sensory experience norms with other psycholinguistic variables (e.g., imageability and age of acquisition) were analyzed. We also investigated the degree to which SER predicted performance in visual word recognition tasks (lexical decision, word naming, and progressive demasking). The analyses indicated that SER reliably predicted response times in lexical decision, but not in word naming or progressive demasking. The findings are discussed in relation to the status of SER, the role of semantic code activation in visual word recognition, and the embodied view of cognition.

  18. SERS activity of Au nanoparticles coated on an array of carbon nanotube nested into silicon nanoporous pillar

    International Nuclear Information System (INIS)

    Jiang Weifen; Zhang Yanfeng; Wang Yusheng; Xu Lei; Li Xinjian

    2011-01-01

    A novel composite structure, Au nanoparticles coated on a nest-shaped array of carbon nanotube nested into a silicon nanoporous pillar array (Au/NACNT/Si-NPA), was fabricated for surface-enhanced Raman scattering (SERS). The morphology of the Au/NACNT/Si-NPA composite structure was characterized with the aid of scanning electron microscopy, X-ray diffraction instrumentation and Transmission electron microscopy. Compared with SERS of rhodamine 6G (R6G) adsorbed on SERS-active Au substrate reported, the SERS signals of R6G adsorbed on these gold nanoparticles were obviously improved. This was attributed to the enlarged specific surface area for adsorption of target molecules brought by the nest-shaped CNTs structure.

  19. SERS spectroscopy of kaempferol and galangin under the interaction of human serum albumin with adsorbed silver nanoparticles

    Science.gov (United States)

    Zhang, Wei; Bai, Xueyuan; Wang, Yingping; Zhao, Bing; Zhao, Daqing; Zhao, Yu

    Raman and surface-enhanced Raman scattering (SERS) spectroscopy were employed to probe the interaction of the flavonol drugs, kaempferol and galangin, with human serum albumin (HSA). SERS spectra of both flavonol derivatives were obtained from a colloidal silver surface in physiological condition, based on the high performance of the enhanced substrate, the most enhanced modes of kaempferol and galangin were those with certain motions perpendicular to the metal surface. The SERS spectra were allowed to predict similar orientation geometry for both of the drugs on the colloidal surface with minor difference. In addition, both flavonols-HSA complexes were prepared in different concentration ratios and the orientated differences between kaempferol and galangin were investigated by SERS.

  20. Structural and functional characterization of hBD-1(Ser35), a peptide deduced from a DEFB1 polymorphism.

    Science.gov (United States)

    Circo, Raffaella; Skerlavaj, Barbara; Gennaro, Renato; Amoroso, Antonio; Zanetti, Margherita

    2002-04-26

    beta-Defensins are mammalian antimicrobial peptides that share a unique disulfide-bonding motif of six conserved cysteines. An intragenic polymorphism of the DEFB1 gene that changes a highly conserved Cys to Ser in the peptide coding region has recently been described. The deduced peptide cannot form three disulfide bonds, as one of the cysteines is unpaired. We have determined the cysteine connectivities of a corresponding synthetic hBD-1(Ser35) peptide, investigated the structure by circular dichroism spectroscopy, and assayed the in vitro antimicrobial activity. Despite a different arrangement of the disulfides, hBD-1(Ser35) proved as active as hBD-1 against the microorganisms tested. This activity likely depends on the ability of hBD-1(Ser35) to adopt an amphipathic conformation in hydrophobic environment, similar to the wild type peptide, as suggested by CD spectroscopy.

  1. Incorporation of multilayered silver nanoparticles into polymer brushes as 3-dimensional SERS substrates and their application for bacteria detection

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qian; Wang, Xiang-Dong; Tian, Ting; Chu, Li-Qiang, E-mail: chuliqiang@tust.edu.cn

    2017-06-15

    Highlights: • POEGMA/AgNPs composite film prepared via the in-stacking method is employed as 3D SERS substrate. • Control over POEGMA chain length is achieved via SI-ATRP method. • Influence of POEGMA chain length and in-stacking process on SERS performance is investigated. • The 3D SERS substrate is used for the ultrasensitive detection of ATP and S. aureus. - Abstract: Surface-enhanced Raman scattering (SERS) sensors have been extensively studied for ultrasensitive detection of diverse chemical or biological analytes. Facile fabrication of highly sensitive SERS substrates is believed to be of crucial importance in these analytical applications. In this regard, the preparation of 3-dimensional (3D) SERS substrates are explored via the incorporation of multilayered silver nanoparticles (AgNPs) into poly (oligo(ethylene glycol) methacrylate) (POEGMA) brushes by repeating the immersion-rinsing-drying steps for different lengths of time (i.e., the so-called in-stacking method). The POEGMA brushes of different chain lengths are synthesized by surface-initiated atom transfer radical polymerization (ATRP) with various reaction time. The resulting POEGMA/AgNP nanocomposites are characterized by FE-SEM, UV–vis and Raman spectroscopy. FE-SEM and UV–vis results indicate that the AgNPs are successfully incorporated into the POEGMA brushes with a 3D configuration. The nanocomposite films are employed as SERS substrates for the detection of a Raman reporter molecule (i.e., 4-aminothiophenol), giving rise to an enhancement factor of up to 1.29 × 10{sup 7} and also having relatively good uniformity and reproducibility. The obtained 3D SERS substrates are also used for the detection of a typical gram-positive bacterium, Staphylococcus aureus. The limit of detection is found to be as low as ca. 8 CFU/mL.

  2. Glutamate Counteracts Dopamine/PKA Signaling via Dephosphorylation of DARPP-32 Ser-97 and Alteration of Its Cytonuclear Distribution.

    Science.gov (United States)

    Nishi, Akinori; Matamales, Miriam; Musante, Veronica; Valjent, Emmanuel; Kuroiwa, Mahomi; Kitahara, Yosuke; Rebholz, Heike; Greengard, Paul; Girault, Jean-Antoine; Nairn, Angus C

    2017-01-27

    The interaction of glutamate and dopamine in the striatum is heavily dependent on signaling pathways that converge on the regulatory protein DARPP-32. The efficacy of dopamine/D1 receptor/PKA signaling is regulated by DARPP-32 phosphorylated at Thr-34 (the PKA site), a process that inhibits protein phosphatase 1 (PP1) and potentiates PKA action. Activation of dopamine/D1 receptor/PKA signaling also leads to dephosphorylation of DARPP-32 at Ser-97 (the CK2 site), leading to localization of phospho-Thr-34 DARPP-32 in the nucleus where it also inhibits PP1. In this study the role of glutamate in the regulation of DARPP-32 phosphorylation at four major sites was further investigated. Experiments using striatal slices revealed that glutamate decreased the phosphorylation states of DARPP-32 at Ser-97 as well as Thr-34, Thr-75, and Ser-130 by activating NMDA or AMPA receptors in both direct and indirect pathway striatal neurons. The effect of glutamate in decreasing Ser-97 phosphorylation was mediated by activation of PP2A. In vitro phosphatase assays indicated that the PP2A/PR72 heterotrimer complex was likely responsible for glutamate/Ca 2+ -regulated dephosphorylation of DARPP-32 at Ser-97. As a consequence of Ser-97 dephosphorylation, glutamate induced the nuclear localization in cultured striatal neurons of dephospho-Thr-34/dephospho-Ser-97 DARPP-32. It also reduced PKA-dependent DARPP-32 signaling in slices and in vivo Taken together, the results suggest that by inducing dephosphorylation of DARPP-32 at Ser-97 and altering its cytonuclear distribution, glutamate may counteract dopamine/D1 receptor/PKA signaling at multiple cellular levels. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Cómo comunicar y ser competente: habilidades comunicativas y competencias profesionales y académicas

    OpenAIRE

    Fernández Prados, Juan Sebastián

    2016-01-01

    Reseña del libro "Cómo comunicar y ser competente: habilidades comunicativas y competencias profesionales y académicas" Fernández Prados, JS. (2016). Cómo comunicar y ser competente: habilidades comunicativas y competencias profesionales y académicas. REDU. Revista de Docencia Universitaria. 14(2):345-347. doi:10.4995/redu.2016.5998 345 347 14 2

  4. Amnesic shellfish poisoning biotoxin detection in seawater using pure or amino-functionalized Ag nanoparticles and SERS.

    Science.gov (United States)

    Müller, Csilla; Glamuzina, Branko; Pozniak, Iva; Weber, Karina; Cialla, Dana; Popp, Jürgen; Cîntă Pînzaru, Simona

    2014-12-01

    Domoic acid (DA) biotoxin responsible for the amnesic shellfish poisoning (ASP) has been unambiguously detected in seawater in a broad range of concentration, with both pure and amino-functionalized Ag nanoparticles employed for surface enhanced Raman scattering (SERS). To achieve this, a comprehensive SERS study on DA dissolved in distilled water has been conducted. SERS of DA dissolved in seawater in concentrations ranging from 3.3 × 10(-4) to 3.3 × 10(-8) mol l(-1) exhibited specific signal, completely different to those of the corresponding DA aqueous solutions, due to the seawater interference in the overall SERS effect. In order to assess the capability of the technique as a cheaper alternative for rapid and unambiguous detection of the DA biotoxin in seawater, three detection schemes have been proposed. DA was detectable at 0.33 nmoll(-1) concentration (0.33) dissolved in distilled water and 0.033 nmol l(-1) (0.033 ppb) in seawater respectively, much lower than the admitted level by the current regulation. A solvent specific interaction of DA with the NPs was concluded, since DA aqueous solution added to Ag nanoparticles provided different SERS signal compared to that of DA directly dissolved in seawater. Employing amino-functionalized Ag nanoparticles with 4-aminothiophenol as SERS tag, SERS signal of DA on amino-AgNPs revealed significant specificity associated with the aromatic primary amine interaction of the SERS tag with DA, thus allowing DA detection in seawater at 4.16 × 10(-4) mol l(-1) concentration, much higher than in the case of pure NPs. To highlight the findings, a brief literature review to date on the DA biotoxin detection was also provided. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. NARRATIVAS EM CONVERGÊNCIAS: SER-AGIR EM UMA METODOLOGIA COMPLEXA

    Directory of Open Access Journals (Sweden)

    Felipe Gustsack

    2008-07-01

    Full Text Available Esse estudo questiona a suficiência dos aportes teóricos vinculados ao paradigma da complexidade para a emergência de uma metodologia complexa da aprendizagem e demais afazeres do campo da educação. Nossas hipóteses partem da convicção de que tais constructos dão conta dessas especificidades, potencializando o conhecer como um ser-agir em convivência. Procuramos demonstrar essa perspectiva, nesse texto, procedendo à descrição do funcionamento do Grupo de Ações e Investigações Autopoiéticas - GAIA, colocando-nos como sujeitos das ações de pesquisa, como observadores implicados no ato mesmo de observar, o que vincula este estudo às abordagens autopoiéticas e metacognitivas. O desafio é possibilitar, a partir de vivências dialógicas em ambientes complexos como as redes presenciais e virtuais de aprendizagens, novas compreensões acerca da inseparabilidade do conhecer-viver como fluxo passível de aplicação na educação. Articulando pesquisas de diferentes áreas do conhecimento, os pesquisadores envolvidos com o GAIA tendem a convergir na defesa de uma educação que se tece junto; que faz emergir o respeito mútuo, a amorosidade e também a morosidade necessária ao ser-agir na consciência de que cada organismo conspira para a vida com seu próprio ritmo e implicações cósmicas. Nossas conclusões apontam para vínculos significativos entre os recortes teóricos apresentados e a compreensão do observar-agir com um modo de pesquisar e de aprender, tendo como veículos as narrativas do grupo em convergências diversas, processo que nominamos como ontoepistemogênese. Além disso, demonstramos com esse estudo a processualidade das narrativas como fluxos que nos permitem mapear uma metodologia complexa, que emerge e faz emergir o ser-conhecer a partir de padrões que conectam e marcadores conceituais. Palavras-chave: educação; complexidade; linguagem; narrativas; aprendizagem.

  6. Economia verde: por que o otimismo deve ser aliado ao ceticismo da razão

    Directory of Open Access Journals (Sweden)

    Andrei Cechin

    2012-01-01

    Full Text Available A iniciativa da economia verde carrega consigo o otimismo da vontade de que a economia pode e deve ser impulsionada por investimentos em atividades limpas em contraposição à extração de recursos naturais e à indústria poluente. No entanto, existem limites à ênfase que se coloca nos aumentos de eficiência e na substituição entre setores de uma economia. Para ser verde de fato, a redução no impacto ambiental por unidade do PIB deve ser maior do que o aumento do PIB num período. Mesmo que evidências recentes mostrem que alguns países já passaram do pico no uso de materiais e energia, globalmente a extração de recursos naturais e a emissão de CO2 só tem aumentado. Uma provável causa é porque países ricos têm terceirizado as atividades poluentes para países mais pobres. É hora de trazer o ceticismo da razão para o debate e discutir seriamente o decrescimento, não do PIB ou das oportunidades de desenvolvimento humano, mas da extração de recursos e da emissão de carbono globais.The green economy initiative carries with it the optimistic view that the economy can and should be driven by investments in clean activities as opposed to the extraction of natural resources and polluting industries. However there are limits to the emphasis that is often put on efficiency improvements and on the substitution between sectors of an economy. For the economy to be green, the reduction in environmental impact per unit of GDP should be higher than GDP growth over a period. Even though recent evidence shows that some countries aparently passed the peak in the use of materials and energy, global extraction of natural resources and CO2 emissions has increased. A probable cause is that rich countries have outsourced polluting activities to poorer countries. It is time to bring the skepticism of reason to the debate and seriously discuss degrowth, not of GDP or of opportunities for human development, but of the global resource extration

  7. Apps y gestión de marca ¿es indispensable ser mobile?

    Directory of Open Access Journals (Sweden)

    Zahaira González Romo

    2011-05-01

    Full Text Available La gestión estratégica de la marca a través de los medios de comunicación digital ha cobrado especial relevancia en los últimos años, y prácticamente todas las empresas que se aprecien de llevar una comunicación acorde a sus públicos han desarrollado herramientas y adaptado su comunicación de marca a los diferentes soportes, medios y entornos que han ido emergiendo, hasta el punto de que este proceso ha sufrido una metamorfosis que no todas las empresas consiguen asumir y entender. No sólo hablamos de un replanteamiento y adaptación a las nuevas tecnologías, sino una “nueva forma” de pensar las marcas y su repercusión e imagen en la mente de los consumidores. Tal es el caso de las aplicaciones para los smartphones, que se han desarrollado con una virulencia impresionante, aproximadamente 200.000 actualmente, y el número continúa creciendo. Este estudio pretende ser una primera aproximación a la aparición de las marcas en las aplicaciones para móviles, específicamente en las aplicaciones destinadas a iPhone.Gracias esta investigación sabemos que es indispensable tener en cuenta tres criterios básicos en el desarrollo de aplicaciones; el primero y más importante es que los anunciantes deben centrarse en el análisis de las necesidades de los usuarios, determinar sus objetivos, elaborar planes de integración y sobre todo preparar los medios de comunicación multicanal y de apoyo a la comercialización. Si la aplicación es correcta pero no funciona adecuadamente, deteriora la imagen de la marca de cara al cliente. En segundo lugar, la experiencia del usuario en las aplicaciones móviles debe ser complementaria y coherente con su experiencia a través de otros canales, es decir, debe mantenerse fiel a la marca y a la identidad de la empresa. Y el tercer criterio, es importante para la marca ir adaptándose a las nuevas tecnologías, pues una incorporación precaria y mal desarrollada puede ser más perjudicial que no el

  8. ser puntura como complemento en el tratamiento de la rinitis alérgica

    Directory of Open Access Journals (Sweden)

    Enrique Arce-Morera

    2016-09-01

    Full Text Available Objetivos: evaluar la utilidad de la láser puntura como tratamiento complementario en la rinitis alérgica. Relacionar la mejoría clínica entre el género y los grupos de edades en los casos investigados en este estudio. Métodos:se realizó un estudio de tipo experimental, prospectivo y longitudinal, durante los meses de junio a diciembre de 2013 a los pacientes que asistieron al Servicio de Rehabilitación Integral del Policlínico Docente Dr. Tomás Romay remitidos por el Servicio de Otorrinolaringología del municipio de Artemisa. Integraron la muestra 62 pacientes: 31 recibieron tratamiento convencional (Grupo Control y los 31 restantes recibieron tratamiento convencional y láser puntura (Grupo Estudio. Para determinar confiabilidad del estudio se utilizó la prueba para diferencia de proporciones en la comparación entre ambos grupos al final del tratamiento con un nivel de significación ά 0,05. Resultados: en este estudio 27 pacientes (87,08% del grupo estudio presentaron mejoría en sus síntomas, no así los del grupo control con solo 19 pacientes mejorados (61,29%. Predominaron los enfermos del género femenino con 22 casos que mostraron mejoría clínica (91,66 % y de igual manera ocurrió en los grupos de edades hasta 19 años con 18 pacientes (90,00%. Conclusiones: resultó de utilidad el tratamiento complementario con láser puntura en la rinitis alérgica, en cuanto a la de regresión de los síntomas de esta molesta enfermedad que se presentó con mayor frecuencia y con mejores resultados en el género femenino, en grupos de edades infantiles y en la adolescencia.

  9. Descripción del coronógrafo a ser instalado en Argentina (MICA)

    Science.gov (United States)

    Stenborg, G.; Francile, C.; Schwenn, R.; Epple, A.; Rovira, M.

    El ``Coronógrafo de espejo para Argentina'' es un telescopio solar terrestre a ser colocado en el Observatorio Astronómico Félix Aguilar (El Leoncito), antes de finalizar 1996, como parte de un programa de ciencia bilateral entre Alemania y Argentina. Eclipses fotográficos de alta resolución han revelado que la corona solar es altamente estructurada y variable. De hecho, está contínuamente deformada y moldeada por los movimientos convectivos de los extremos de los arcos magnéticos en la fotosfera, estando, en muchas oportunidades, afectada por explosivas liberaciones de energía. MICA, en conjunción con otros telescopios solares espaciales y terrestres, tratará de contribuir al entendimiento de cuestiones fundamentales de la física solar. Entre ellas: cómo la corona está siendo calentada, dónde y cómo el viento solar es acelerado, qué causa los transitorios coronales, etc. Para ello investigará la distribución de los parámetros del plasma y su evolución con el tiempo, la estructura espacial de la corona en fina y gran escala, procesos que ocurren en los transitorios coronales y factores que los disparan, etc. Para responder a estas cuestiones MICA observará la atmósfera solar por sobre el limbo entre 1.1 y 2 radios solares aproximadamente, usando un nuevo tipo de sistema coronográfico que permite suprimir el brillo del disco solar suficientemente bien, tomando las imágenes con una cámara CCD de 1024x1024 pixels, codificada en 12 bits, pudiendo el mismo ser operado en forma remota. En la presente exposición describiremos las características del instrumento, cómo será controlado y qué esperamos observar basados en las imágenes obtenidas por los telescopios de similares características LASCO C1 a bordo del SOHO y PICO (ubicado en el Observatorio de Pic du Midi, Francia).

  10. La comprensión de ser según Bernhard Welte

    Directory of Open Access Journals (Sweden)

    César Lambert

    2003-01-01

    Full Text Available El artículo intenta mostrar que la noción de comprensión de salvación, que Welte expone en su libro Heilsverständnis (publicado en 1966, tiene que ser entendida desde el concepto de comprensión de ser, que el propio Welte también utiliza y que él toma del pensamiento de Martin Heidegger. La comprensión de ser se articula, por su parte, como comprensión de mundo; mundo no se da sin el Yo humano, y éste no existe sino en tanto está en el mundo. Es lo que Welte denomina "Weltdasein". Ahora, el mundo en su conexion esencial con nosotros tiene el carácter fundamental de la significatividad. Pues bien, a propósito de esta última Welte hace ver que hay un orden de significatividad: las significaciones concretas suponen un horizonte previo, que es una totalidad significativa o principio de la significatividad. Y este principio no es otra cosa que una pre-comprensión de la salvación. Se trata aquí de una plenitud de sentido -ontológica, no meramente óntica- que permite que los entes y especialmente los seres humanos sean a cabalidad lo que sonThis article argues that Welte's notion of understanding of salvation, in his book Heilsverständnis (1966, should be comprehended from Martin Heidegger's understanding of being. This understanding of being is articulated with an understanding of the world, in which the world is not given without the human subject, and this exist only in relation with the world. This is what Welte refers to as "Weltdasein". Now our essential connection with the world has the fundamental character of significance. Welte describes an order of significance: the concrete order of significance presupposes a previous horizon, which is a totality or principle of significance. This principle is nothing other than a precomprehension of salvation: understood as the fullness of meaning -ontological, not only ontic- that allows beings and especially human beings to be completely what they are

  11. Investigation of simultaneously existed Raman scattering enhancement and inhibiting fluorescence using surface modified gold nanostars as SERS probes.

    Science.gov (United States)

    Shan, Feng; Zhang, Xiao-Yang; Fu, Xing-Chang; Zhang, Li-Jiang; Su, Dan; Wang, Shan-Jiang; Wu, Jing-Yuan; Zhang, Tong

    2017-07-28

    One of the main challenges for highly sensitive surface-enhanced Raman scattering (SERS) detection is the noise interference of fluorescence signals arising from the analyte molecules. Here we used three types of gold nanostars (GNSs) SERS probes treated by different surface modification methods to reveal the simultaneously existed Raman scattering enhancement and inhibiting fluorescence behaviors during the SERS detection process. As the distance between the metal nanostructures and the analyte molecules can be well controlled by these three surface modification methods, we demonstrated that the fluorescence signals can be either quenched or enhanced during the detection. We found that fluorescence quenching will occur when analyte molecules are closely contacted to the surface of GNSs, leading to a ~100 fold enhancement of the SERS sensitivity. An optimized Raman signal detection limit, as low as the level of 10 -11  M, were achieved when Rhodamine 6 G were used as the analyte. The presented fluorescence-free GNSs SERS substrates with plentiful hot spots and controllable surface plasmon resonance wavelengths, fabricated using a cost-effective self-assembling method, can be very competitive candidates for high-sensitive SERS applications.

  12. Enhanced Self-Organized Dewetting of Ultrathin Polymer Blend Film for Large-Area Fabrication of SERS Substrate.

    Science.gov (United States)

    Zhang, Huanhuan; Xu, Lin; Xu, Yabo; Huang, Gang; Zhao, Xueyu; Lai, Yuqing; Shi, Tongfei

    2016-12-06

    We study the enhanced dewetting of ultrathin Polystyrene (PS)/Poly (methyl methacrylate) (PMMA) blend films in a mixed solution, and reveal the dewetting can act as a simple and effective method to fabricate large-area surface-enhanced Raman scattering (SERS) substrate. A bilayer structure consisting of under PMMA layer and upper PS layer forms due to vertical phase separation of immiscible PS/PMMA during the spin-coating process. The thicker layer of the bilayer structure dominates the dewetting structures of PS/PMMA blend films. The diameter and diameter distribution of droplets, and the average separation spacing between the droplets can be precisely controlled via the change of blend ratio and film thickness. The dewetting structure of 8 nm PS/PMMA (1:1 wt%) blend film is proved to successfully fabricate large-area (3.5 cm × 3.5 cm) universal SERS substrate via deposited a silver layer on the dewetting structure. The SERS substrate shows good SERS-signal reproducibility (RSD polymer blend films broadens the application of dewetting of polymer films, especially in the nanotechnology, and may open a new approach for the fabrication of large-area SERS substrate to promote the application of SERS substrate in the rapid sensitive detection of trace molecules.

  13. Site-Specific SERS Assay for Survivin Protein Dimer: From Ensemble Experiments to Correlative Single-Particle Imaging.

    Science.gov (United States)

    Wissler, Jörg; Bäcker, Sandra; Feis, Alessandro; Knauer, Shirley K; Schlücker, Sebastian

    2017-08-01

    An assay for Survivin, a small dimeric protein which functions as modulator of apoptosis and cell division and serves as a promising diagnostic biomarker for different types of cancer, is presented. The assay is based on switching on surface-enhanced Raman scattering (SERS) upon incubation of the Survivin protein dimer with Raman reporter-labeled gold nanoparticles (AuNP). Site-specificity is achieved by complexation of nickel-chelated N-nitrilo-triacetic acid (Ni-NTA) anchors on the particle surface by multiple histidines (His 6 -tag) attached to each C-terminus of the centrosymmetric protein dimer. Correlative single-particle analysis using light sheet laser microscopy enables the simultaneous observation of both elastic and inelastic light scattering from the same sample volume. Thereby, the SERS-inactive AuNP-protein monomers can be directly discriminated from the SERS-active AuNP-protein dimers/oligomers. This information, i.e. the percentage of SERS-active AuNP in colloidal suspension, is not accessible from conventional SERS experiments due to ensemble averaging. The presented correlative single-particle approach paves the way for quantitative site-specific SERS assays in which site-specific protein recognition by small chemical and in particular supramolecular ligands can be tested. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Tethering of Gly-Arg-Gly-Asp-Ser-Pro-Lys Peptides on Mg-Doped Hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Alessandro Pistone

    2017-02-01

    Full Text Available Stem cell homing, namely the recruitment of mesenchymal stem cells (MSCs to injured tissues, is highly effective for bone regeneration in vivo. In order to explore whether the incorporation of mimetic peptide sequences on magnesium-doped (Mg-doped hydroxyapatite (HA may regulate the homing of MSCs, and thus induce cell migration to a specific site, we covalently functionalized MgHA disks with two chemotactic/haptotactic factors: either the fibronectin fragment III1-C human (FF III1-C, or the peptide sequence Gly-Arg-Gly-Asp-Ser-Pro-Lys, a fibronectin analog that is able to bind to integrin transmembrane receptors. Preliminary biological evaluation of MSC viability, analyzed by 3-(4,5-dimethyl­thiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT test, suggested that stem cells migrate to the MgHA disks in response to the grafted haptotaxis stimuli.

  15. Quantification of a bacterial secondary metabolite by SERS combined with SLM extraction for bioprocess monitoring.

    Science.gov (United States)

    Morelli, Lidia; Andreasen, Sune Zoëga; Jendresen, Christian Bille; Nielsen, Alex Toftgaard; Emnéus, Jenny; Zór, Kinga; Boisen, Anja

    2017-11-20

    During the last few decades, great advances have been reached in high-throughput design and building of genetically engineered microbial strains, leading to a need for fast and reliable screening methods. We developed and optimized a microfluidic supported liquid membrane (SLM) extraction device and combined it with surface enhanced Raman scattering (SERS) sensing for the screening of a biological process, namely for the quantification of a bacterial secondary metabolite, p-coumaric acid (pHCA), produced by Escherichia coli. The microfluidic device proved to be robust and reusable, enabling efficient removal of interfering compounds from the real samples, reaching more than 13-fold up-concentration of the donor at 10 μL min -1 flow rate. With this method, we quantified pHCA directly from the bacterial supernatant, distinguishing between various culture conditions based on the pHCA production yield. The obtained data showed good correlation with HPLC analysis.

  16. Estudo piloto sobre alimentos que devem ser evitados nos portadores de psoríase

    OpenAIRE

    Festugato,Moira

    2011-01-01

    FUNDAMENTOS: Psoríase é uma doença inflamatória crônica, sistêmica, mediada por fatores imunológicos. Serão abordados os alimentos que atuam sobre estes fatores, contribuindo para a psoríase. Como doença sistêmica, que compartilha o mesmo substrato fisiopatológico com outras comorbidades, a dieta alimentar também leva à piora das comorbidades. OBJETIVO: Destacar um grupo de alimentos que pode atuar como um fator de manifestação e/ou agravo da psoríase e ao mesmo tempo viabilizar estratégias i...

  17. Fiber-optic SERS microfluidic chip based on light-induced gold nano-particle aggregation

    Science.gov (United States)

    Liu, Haitao; Liu, Jiansheng; Li, Shaopeng; Chen, Luoyang; Zhou, Hongwen; Zhu, Jinsong; Zheng, Zheng

    2015-10-01

    A novel optofluidic surface-enhanced Raman scattering (SERS) chip was specially designed and fabricated using polydimethylsiloxane (PDMS) and embedded with normal silica multi-mode optical fibers. Unlike in a conventional Raman detection configuration where an angle of 90° is commonly adopted, here the orientations of the excitation fiber and the collection fiber was set at such an obtuse angle so that the light beam from the excitation fiber can illuminate the endface, but is not within the acceptance angle of the collection fiber. It was found that with the laser irradiating on the endface of the collection fiber in the sample solution, the Raman scattering intensity continued to grow and a level about 30-times than its initial intensity was observed, which was understood by light-induced gold nano-particle aggregation. The effects of fibers' coupling angles, positions and laser irradiation power on the aggregation were investigated.

  18. Gênero e geografia no espaço do vir-a-ser

    Directory of Open Access Journals (Sweden)

    María Franco Garcia

    2011-11-01

    Full Text Available Nos últimos tempos os membros do CEGeT, Centro de Estudos de Geografia do Trabalho, temos desenvolvido uma crescente preocupação: a complexa relação entre classe, gênero e território, junto a outros aspectos da cultura e a identidade. Além da literatura que chega às nossas mãos e a informação impressa que podemos acessar, navegamos pelos "espaços do vir-a-ser" on-line. Recolhemos aqui algumas destas trilhas virtuais, que esperamos se ampliem em próximas edições. Apenas é o começo da navegação, no obstante podem-se constituir no passo mais importante na pesquisa, o primeiro, ou uma porta de entrada e redimensionamento do nosso objeto de estudo: a realidade analógica.  

  19. PODER DE PROJETAR-SE DO SER-NO-MUNDO EM MERLEAU-PONTY

    Directory of Open Access Journals (Sweden)

    Ivanhoé Albuquerque Leal

    2015-07-01

    Full Text Available Este texto analisa a espacialidade e a motricidade do corpopróprio investigadas por Merleau-Ponty na Fenomenologia dapercepção e indica que elas descerram a perspectiva existencial etemporal implicadas no poder de projetar-se do ser no mundo. Aintencionalidade corporalizada responde às solicitações do ambientevital e recria sempre uma orientação para a existência. Tal atitudenão é equiparável a um puro estipular de posições no mundo físico.Isto é, a tonalidade do perceber é motivada, nesse sentido, o espaçoé existencial, assim como a existência é espacial, quer dizer, aespacialidade da existência corresponde à deiscência do existir, auma força em direção ao mundo.

  20. La inconstitucionalidad de algunas restricciones al derecho a ser elegido en Colombia

    Directory of Open Access Journals (Sweden)

    Juan Fernando Reyes Kuri

    2009-12-01

    Full Text Available Este artículo cuestiona la facultad normativa que existe en Colombia para restringir el derecho a ser elegido por razones distintas de las contenidas en los tratados internacionales que hacen parte del bloque de constitucionalidad y que, es claro, deben primar en el orden interno. El Código Único Disciplinario (Ley 734 de 2002, por ejemplo, permite que mediante un proceso de carácter administrativo, distinto del penal, se limiten duramente los derechos políticos fundamentales de los ciudadanos, a pesar de lo establecido en el artículo 23 de la Convención Americana sobre Derechos Humanos referente a esta clase de derechos. Sin embargo, la Corte Constitucional insiste en la constitucionalidad de las referidas normas que a todas luces resultan violatorias de nuestra Constitución.

  1. Twaróg i ser smażony – wczoraj i dziś

    OpenAIRE

    Chudy, Sylwia; Makowska, Agnieszka

    2015-01-01

    Zarówno twaróg jak i ser smażony wytwarzany zgodnie przekazywaną z pokolenia na pokolenie recepturą, cieszy się w Polsce ogromnym popytem. Z roku na rok przybywa konsumentów tych produktów także poza granicami kraju, głównie w Niemczech. Początki przerobu mleka na ziemiach polskich datuje się już na początek VI w.p.n.e. Pierwszym produktem pochodzącym z przerobu mleka był twaróg. W XVIII wieku rolnicy pochodzących z obszaru Niemiec i Holandii zapoczątkowali w Wielkopolsce smażenie dojrzałego ...

  2. De la identidad del ser a la pedagogía de la diferencia

    Directory of Open Access Journals (Sweden)

    Ignacio Calderón Almendros

    2016-06-01

    Full Text Available Las distintas definiciones acerca del ser humano intentan identificar una característica que generalizar para todo el género Homo. Esta cuestión nace del principio de identidad, y tiene fuertes repercusiones en las concepciones antropológicas sobre las que se asienta la pedagogía. El cuestionamiento de este principio permitiría dar cabida al conflicto en el discurso pedagógico, así como poner en crisis algunas de las bases sobre las que asentamos el análisis de la diversidad y su atención educativa. Nos puede definir la diferencia en lugar de la homogeneidad, lo que implica el cuestionamiento de la norma.

  3. Luis Álvarez-Gaumé to speak at El Ser Creativo 2011

    CERN Multimedia

    Jordan Juras

    2011-01-01

    During the weekend of 19 October, 2011, Madrid will host this year’s El Ser Creativo – a three-day conference celebrating new ideas that can change the world.   Over the course of the conference, 21 speakers will have the chance to share their opinions and ideas for 21 minutes each – the estimated time that the human brain is able to maintain complete focus. Among the Nobel Prize winners, scientists, doctors, and thinkers invited to this year's conference is Luis Álvarez-Gaumé, a theoretical physicist at CERN. Having made significant contributions to the understanding of gravitation, minimal supergravity theory and supersymmetry, Álvarez-Gaumé was an obvious choice to be invited to share his thoughts about the theory and reality of current physics ideas with the conference attendees. A webcast will be available to stream the entire conference live.

  4. Clarice Lispector e o simbolismo da montanha: Retrato de um ser entre dois mundos

    Directory of Open Access Journals (Sweden)

    Santo Gabriel Vaccaro

    2012-11-01

    Full Text Available Clarice Lispector, en su relato 'Onde estivestes de noite', produce con su divinidad andrógina El-ella y con sus seguidores un movimiento que aborda la sexualidad a partir de nuevos paradigmas y configura una escritura en que el hombre es retratado como un ser irremediablemente escindido entre naturaleza y cultura, entre deseo y razón. Esa dicotomía se extiende a otros personajes clariceanos aquí rescatados, cuya particular caracterización psicológica posibilita un análisis basado en los postulados psicoanalíticos, a partir del texto Cinco lecciones de psicoanálisis de Sigmund Freud.

  5. Vlastos e a noção platônica de ser

    Directory of Open Access Journals (Sweden)

    Carolina Araújo

    2015-12-01

    Full Text Available Este artigo é sobre o significado de ser em Platão de acordo com Gregory Vlastos e suas consequências para a chamada teoria das ideias. Analisam-se aqui as premissas de sua interpretação do argumento do terceiro homem com o objetivo de discutir a teoria dos graus da realidade em relação ao problema da autopredicação. Neste contexto está implícita uma mudança na posição Vlastos, testemunhada sobretudo por sua posterior hipótese sobre a predicação paulina. Esta mudança revelaria – embora isso Vlastos nunca tenha aceitado – que Platão não se compromete com a autopredicação, o que exigiria uma reavaliação da teoria das ideias.

  6. Gold nanomaterials for the selective capturing and SERS diagnosis of toxins in aqueous and biological fluids

    DEFF Research Database (Denmark)

    Hassanain, Waleed A.; Izake, Emad L.; Schmidt, Michael Stenbæk

    2017-01-01

    the extractor nanoparticles within 5min by manipulating the pH environment of the nanoparticles. The regenerated extractor nanoparticles maintained their capture efficiency and, therefore, were re-used to capture of MC-LR from successive samples. The released purified toxin was screened within 10min on gold......A highly sensitive nanosensing method for the combined selective capture and SERS detection of Microcystin-LR (MC-LR) in blood plasma has been developed. The new method utilizes gold coated magnetic nanoparticles that are functionalized with anti MC-LR antibody Fab' fragments for the selective...... capture of MC-LR from aqueous media and blood plasma. Using an oriented immobilization approach, the Fab' fragments are covalently attached to gold surface to form a monolayer with high capture efficiency towards the toxin. After the selective capture, the purified MC-LR molecules were released from...

  7. Gold Incorporated Mesoporous Silica Thin Film Model Surface as a Robust SERS and Catalytically Active Substrate

    Directory of Open Access Journals (Sweden)

    Anandakumari Chandrasekharan Sunil Sekhar

    2016-05-01

    Full Text Available Ultra-small gold nanoparticles incorporated in mesoporous silica thin films with accessible pore channels perpendicular to the substrate are prepared by a modified sol-gel method. The simple and easy spin coating technique is applied here to make homogeneous thin films. The surface characterization using FESEM shows crack-free films with a perpendicular pore arrangement. The applicability of these thin films as catalysts as well as a robust SERS active substrate for model catalysis study is tested. Compared to bare silica film our gold incorporated silica, GSM-23F gave an enhancement factor of 103 for RhB with a laser source 633 nm. The reduction reaction of p-nitrophenol with sodium borohydride from our thin films shows a decrease in peak intensity corresponding to –NO2 group as time proceeds, confirming the catalytic activity. Such model surfaces can potentially bridge the material gap between a real catalytic system and surface science studies.

  8. Electron microscopy localization and characterization of functionalized composite organic-inorganic SERS nanoparticles on leukemia cells

    International Nuclear Information System (INIS)

    Koh, Ai Leen; Shachaf, Catherine M.; Elchuri, Sailaja; Nolan, Garry P.; Sinclair, Robert

    2008-01-01

    We demonstrate the use of electron microscopy as a powerful characterization tool to identify and locate antibody-conjugated composite organic-inorganic nanoparticle (COINs) surface enhanced Raman scattering (SERS) nanoparticles on cells. U937 leukemia cells labeled with antibody CD54-conjugated COINs were characterized in their native, hydrated state using wet scanning electron microscopy (SEM) and in their dehydrated state using high-resolution SEM. In both cases, the backscattered electron (BSE) detector was used to detect and identify the silver constituents in COINs due to its high sensitivity to atomic number variations within a specimen. The imaging and analytical capabilities in the SEM were further complemented by higher resolution transmission electron microscopy (TEM) images and scanning Auger electron spectroscopy (AES) data to give reliable and high-resolution information about nanoparticles and their binding to cell surface antigens.

  9. Preparation of gold nanoparticles-agarose gel composite and its application in SERS detection.

    Science.gov (United States)

    Ma, Xiaoyuan; Xia, Yu; Ni, Lili; Song, Liangjing; Wang, Zhouping

    2014-01-01

    Agarose gel/gold nanoparticles hybrid was prepared by adding gold nanoparticles to preformed agarose gel. Nanocomposite structures and properties were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and UV-Vis-NIR absorption spectroscopy. Based on the swelling-contraction characteristics of agarose gel and the adjustable localized surface plasmon resonance (LSPR) of the gold nanoparticles, the nanocomposites were used as surface enhanced Raman scattering (SERS) substrate to detect the Raman signal molecules (NBA, MBA, 1NAT). Results revealed that the porous structure of the agarose gel provided a good carrier for the enrichment of the gold nanoparticles. The gold nanoparticles dynamic hot-spot effect arising from the agarose gel contraction loss of water in the air greatly enhanced the Raman signal. Furthermore, the gel could be cleaned with washing solution and recycling could be achieved for Raman detection. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Enfermagem: uma maneira própria de ser, estar, pensar e fazer

    Directory of Open Access Journals (Sweden)

    Maria Ribeiro Lacerda

    1998-06-01

    Full Text Available O presente ensaio busca estimular os enfermeiros e estudantes de Graduação e Pós-graduação de Enfermagem a terem cada vez mais conhecimento e orgulho dá Enfermagem. Trás uma explanação sintética da Enfermagem enquanto profissão, disciplina, ciência, arte, tecnologia e para além de ciência e arte. Considera a Enfermagem como algo que a enfermeiras criam ao cuidar de alguém através de um conhecimento profissional e de uma maneira própria de ser enfermeira.

  11. Entre el ser y el poder. La vida. Una apuesta prevaricante

    OpenAIRE

    López Petit, Santiago, 1950-

    1990-01-01

    Esta tesis no quiere ser situada dentro del campo de la filosofía política, pues ni busca recuperar el verdadero sentido de las antiguas categorías (democracia, libertad...) ni elabora una critica del totalitarismo. La política se ha velado al convertirse en simple intervención de dominio sobre "lo social" y en espectáculo de la representación. No se trata de restaurarla. Más bien hay que estar atento para no confundir este mutarse de la política con la desaparición de "'lo político". Aquí no...

  12. Consejos fundamentales para ser un periodista freelance en línea

    Directory of Open Access Journals (Sweden)

    Lic. Rocío Jiménez

    2000-01-01

    Full Text Available Como afirma Philip Meyer, "Un periodista competente es un científico en ejercicio". Los periodistas, como los científicos, buscan demostrar la realidad: observan lo que les rodea, lo estudian y analizan, para sacar luego sus propias hipótesis; a partir de éstas calibran las consecuencias y desarrollan una metodología, que puede ser comprobada empíricamente dando lugar a teorías que se aplicarán de nuevo, y que, muchas veces, se convierten en paradigmas. Hoy, más que nunca, con la aparición de Internet el comportamiento en la red se está autoinventando y el periodista en línea juega un papel decisivo en la definición de la comunicación en la web.

  13. SERS spectroscopy for detection of hydrogen cyanide in breath from children colonised with P. aeruginosa

    DEFF Research Database (Denmark)

    Lauridsen, Rikke Kragh; Skou, Peter Bæk; Rindzevicius, Tomas

    2017-01-01

    ) nanochip optimised for detection of trace amounts of the P. aeruginosa biomarker hydrogen cyanide (HCN) was mounted inside a Tedlar bag, which the patient breathed into. The SERS chip was then analysed in a Raman spectrometer, investigating the C≡N peak at 2131 cm-1 and correlated with sputum cultures. One...... new P. aeruginosa colonisation occurred during the trial period. The C≡N peak intensity was enhanced in this sample in contrast to the subject's 3 other samples. Three additional patients had intense C≡N SERS signals from their breath, but no P. aeruginosa was cultured from their sputum....... It is concluded that SERS spectroscopy can be developed into an easy to use hypersensitive clinical prescreening method for detection of HCN in human breath. ...

  14. SERS studies on the interaction between UO22+ and PVP-stabilized silver nanoparticles

    International Nuclear Information System (INIS)

    Roy, M.; Tyagi, A.K.; Kumar, Rakesh; Pandey, A.K.; Goswami, A.

    2010-01-01

    Interaction between uranyl (UO 2 2+ ) ions and silver nanoparticles (Ag-nps) stabilized by suitable polymeric capping agents has been studied in aqueous phase using surface enhanced resonance Raman spectroscopy technique (SERS). Polyvinylpyrrolidone (PVP) stabilized Ag-nps were synthesized by dissolving in water appropriate amount of PVP and AgNO 3 along with a suitable reducing agent in the form of either formamide or sodium borohydride. The solution was vigorously stirred for 5h and finally nanoparticle sols were obtained. A series of analyte samples was prepared by adding an appropriate amount of silver sol to different volumes of uranyl stock solution prepared at pH=3. The solutions were then drop cast on glass slides and dried in air. Preliminary results on drop-cast samples are presented here

  15. Ultrasensitive SERS detection of mercury based on the assembled gold nanochains.

    Science.gov (United States)

    Xu, Liguang; Yin, Honghong; Ma, Wei; Kuang, Hua; Wang, Libing; Xu, Chuanlai

    2015-05-15

    Mercuric ions (Hg(2+)) mediate the transformation of single-stranded DNA to form double helical DNA by T-Hg(2+)-T interaction between base pairs. With this strategy, DNA modified gold nanoparticles (Au NPs) were assembled into chains which were displayed remarkable surface-enhanced Raman scattering (SERS) signal. Under optimized conditions, the length of gold nanochains was directly proportional to the mercuric ions concentrations over 0.001-0.5 ng mL(-1) and the limit of detection (LOD) in drinking water was as low as 0.45 pg mL(-1). With ultrasensitivity and excellent selectivity, this feasible and simple method is potentially as a promising tool for monitoring of mercury ions in food safety and environmental applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Vlastos e a noção platônica de ser

    OpenAIRE

    Carolina Araújo

    2015-01-01

    Este artigo é sobre o significado de ser em Platão de acordo com Gregory Vlastos e suas consequências para a chamada teoria das ideias. Analisam-se aqui as premissas de sua interpretação do argumento do terceiro homem com o objetivo de discutir a teoria dos graus da realidade em relação ao problema da autopredicação. Neste contexto está implícita uma mudança na posição Vlastos, testemunhada sobretudo por sua posterior hipótese sobre a predicação paulina. Esta mudança revelaria – embora isso V...

  17. Tratamiento del herpes simple labial con láser de baja potencia

    OpenAIRE

    Bianka M. González; Adel Hernández; Adonis Estevez

    2008-01-01

    Introducción: El herpes simple es causado por Herpes virus hominis, que produce una afección eruptiva aguda de uno o más grupos de vesículas sobre una base eritematosa; puede localizarse en cualquier parte del cuerpo preferentemente en la boca y los genitales precedida y acompañada de ardor y prurito.Objetivos: Se evaluó la efectividad del tratamiento con láser de baja potencia en relación al tratamiento convencional según la evolución clínica, desaparición de síntomas y signos en los pacient...

  18. Surface-enhanced Raman scattering (SERS) characterization of trace organoarsenic antimicrobials using silver/polydimethylsiloxane nanocomposites.

    Science.gov (United States)

    Olavarría-Fullerton, Jenifier; Wells, Sabrina; Ortiz-Rivera, William; Sepaniak, Michael J; De Jesús, Marco A

    2011-04-01

    Organoarsenic drugs such as roxarsone and 4-arsanilic acid are poultry feed additives widely used in US broilers to prevent coccidosis and to enhance growth and pigmentation. Despite their veterinary benefits there has been growing concern about their use because over 90% of these drugs are released intact into litter, which is often sold as a fertilizing supplement. The biochemical degradation of these antimicrobials in the litter matrix can release significant amounts of soluble As(III) and As(V) to the environment, representing a potential environmental risk. Silver/polydimethylsiloxane (Ag/PDMS) nanocomposites are a class of surfaceenhanced Raman scattering (SERS) substrates that have proven effective for the sensitive, reproducible, and field-adaptable detection of aromatic acids in water. The work presented herein uses for the first time Ag/PDMS nanocomposites as substrates for the detection and characterization of trace amounts of roxarsone, 4-arsanilic acid, and acetarsone in water. The results gathered in this study show that organoarsenic species are distributed into the PDMS surface where the arsonic acid binds onto the embedded silver nanoparticles, enhancing its characteristic 792 cm(-1) stretching band. The chemisorption of the drugs to the metal facilitates its detection and characterization in the parts per million to parts per billion range. An extensive analysis of the distinct spectroscopic features of each drug is presented with emphasis on the interactions of the arsonic acid, amino, and nitro groups with the metal surface. The benefits of SERS based methods for the study of arsenic drugs are also discussed. © 2011 Society for Applied Spectroscopy

  19. EL SER HUMANO AL LÍMITE: UNA MIRADA REFLEXIVA AL HABITANTE DE CALLE

    Directory of Open Access Journals (Sweden)

    Alberto André Restrepo Alzate

    2016-01-01

    Full Text Available El ser humano, permeado por las dinámicas sociales cambiantes de la modernidad, se ve obligado a asumir unos espacios, territorios y formas de vida particulares; razón por la cual este artículo plantea una reflexión acerca del habitante de calle en el contexto urbano, cómo es abocado por éste, cómo es su rostro según los planteamientos de Salcedo (2006 y cuáles condiciones lo ponen en el límite de su existencia. Así mismo, se presenta la exclusión como un factor potenciador de la problemática que divide el mundo en dos: los aceptados e inaceptados, los de adentro y afuera, los incluidos y excluidos; condición que los ubica, según Moreno (2003, en estado de “exclusión” debido a que sus estilos de vida son reprobados por la “sociedad”. Para finalizar, se propone un acercamiento a la teoría de las representaciones sociales desde los planteamientos de Moscovici y Araya Umaña (2002, como herramienta que puede generar una comprensión humana de los habitantes de calle y desde este conocimiento, realizar una reflexión que permita al ciudadano del común sensibilizarse respecto a la representación que tiene de esta población y, de esta forma, identificar que ese sujeto diferente continúa presentándose como un ser humano al límite.

  20. Synthesis of colloidal silver nanoparticle clusters and their application in ascorbic acid detection by SERS.

    Science.gov (United States)

    Cholula-Díaz, Jorge L; Lomelí-Marroquín, Diana; Pramanick, Bidhan; Nieto-Argüello, Alfonso; Cantú-Castillo, Luis A; Hwang, Hyundoo

    2018-03-01

    Ascorbic acid (vitamin C) has an essential role in the human body mainly due to its antioxidant function. In this work, metallic silver nanoparticle (AgNP) colloids were used in SERS experiments to detect ascorbic acid in aqueous solution. The AgNPs were synthesized by a green method using potato starch as reducing and stabilizing agent, and water as the solvent. The optical properties of the yellowish as-synthesized silver colloids were characterized by UV-vis spectroscopy, in which besides a typical band at 410 nm related to the localized surface plasmon resonance of the silver nanoparticles, a shoulder band around 500 nm, due to silver nanoparticle cluster formation, is presented when relatively higher concentrations of starch are used in the synthesis. These starch-capped silver nanoparticles show an intrinsic Raman peak at 1386 cm -1 assigned to deformation modes of the starch structure. The increase of the intensity of the SERS peak at 1386 cm -1 with an increase in the concentration of the ascorbic acid is related to a decrease of the gap between dimers and trimers of the silver nanoparticle clusters produced by the presence of ascorbic acid in the colloid. The limit of detection of this technique for ascorbic acid is 0.02 mM with a measurement concentration range of 0.02-10 mM, which is relevant for the application of this method for detecting ascorbic acid in biological specimen. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Os policiais podem ser controlados? Is it possible to control police officers?

    Directory of Open Access Journals (Sweden)

    Antonio Oliveira

    2010-04-01

    Full Text Available A atividade policial na democracia impõe a questão sobre o controle dos policiais, ou seja, como assegurar que eles, em sua tarefa de assegurar a ordem pública, não violarão os direitos dos cidadãos. A organização policial inclina-se em direção aos mecanismos formais de controle como as normas e os procedimentos, mas essas formas de regulação de conduta podem ser insuficientes, devido à ampla margem de liberdade que os guardas desfrutam nas ruas. Tomando-se como referência os discursos de oficiais policiais militares da Bahia, este artigo discute a prática policial na sociedade democrática e a percepção elaborada pelos policiais dos mecanismos de controle de seus pares e conclui enfatizando os obstáculos que podem ser encontrados na tarefa de controle dos policiais, empecilhos cuja superação torna-se difícil porque têm origem na própria atividade policial.In a democracy, police activity requires control of the police officers, to make sure that in their task of ensuring public order they will not violate the citizens' rights. The police organization leans toward the formal mechanisms of control, such as rules and procedures, but these forms of conduct regulation may be insufficient, due to the large margin of freedom the officers have on the streets. Examining the discourse of military police officers from the state of Bahia, this article discusses the police practice in a democratic society, and the officers' perception of the mechanisms used to control their colleagues. In the conclusion, the paper emphasizes the obstacles that can be found in the task of controlling police officers, obstacles that are difficult to overcome because they have their origin in the police activity.

  2. Corte de placas solares con láser. Estudio de modificaciones microestructurales

    Directory of Open Access Journals (Sweden)

    Ramírez Del Valle, A. J.

    2003-06-01

    Full Text Available In photovoltaic solar cells manufacturing process, system breaks are produced. Recycling improves the material profitability. In this sense, manufacturing of components with non-straight shapes is not feasible using traditional methods. The processing of these materials through Nd-YAG laser, allows manufacturing with any geometric shape. This work shows a study of solar cells cutting process with laser. First of all, it is necessary to carry out a parameter optimization in order to make an accurate material cutting. The microstructure of the cutting area and possible microcompositional changes were studied by scanning electronic miscroscopy (SEM and X-ray analysis (EDX.

    En el proceso de fabricación de placas fotovoltaicas se producen roturas de las células solares, por tanto, el reciclaje es necesario para mejorar la rentabilidad de este proceso, además, la fabricación de piezas de formas curvas no es factible por los métodos tradicionales. El procesado de estos materiales mediante un láser de Nd-YAG, permitirá la fabricación en cualquier forma geométrica además del mejor aprovechamiento de las placas desechadas por estar rotas. El presente trabajo muestra un estudio del proceso de corte de placas solares con láser. En primer lugar se procede a la optimización de los parámetros necesarios para realizar el corte de este material. La microestructura de la zona de corte y los posibles cambios microcomposicionales que se hayan podido producir, se estudian mediante microscopía electrónica de barrido, con microanálisis de energías dispersivas de Rayos X.

  3. Modelling Ser129 phosphorylation inhibits membrane binding of pore-forming alpha-synuclein oligomers.

    Directory of Open Access Journals (Sweden)

    Georg Sebastian Nübling

    Full Text Available BACKGROUND: In several neurodegenerative diseases, hyperphosphorylation at position Ser129 is found in fibrillar deposits of alpha-synuclein (asyn, implying a pathophysiological role of asyn phosphorylation in neurodegeneration. However, recent animal models applying asyn phosphorylation mimics demonstrated a protective effect of phosphorylation. Since metal-ion induced asyn oligomers were identified as a potential neurotoxic aggregate species with membrane pore-forming abilities, the current study was undertaken to determine effects of asyn phosphorylation on oligomer membrane binding. METHODS: We investigated the influence of S129 phosphorylation on interactions of metal-ion induced asyn oligomers with small unilamellar lipid vesicles (SUV composed of POPC and DPPC applying the phosphorylation mimic asyn129E. Confocal single-particle fluorescence techniques were used to monitor membrane binding at the single-particle level. RESULTS: Binding of asyn129E monomers to gel-state membranes (DPPC-SUV is slightly reduced compared to wild-type asyn, while no interactions with membranes in the liquid-crystalline state (POPC-SUV are seen for both asyn and asyn129E. Conversely, metal-ion induced oligomer formation is markedly increased in asyn129E. Surprisingly, membrane binding to POPC-SUV is nearly absent in Fe(3+ induced asyn129E oligomers and markedly reduced in Al(3+ induced oligomers. CONCLUSION: The protective effect of pseudophosphorylation seen in animal models may be due to impeded oligomer membrane binding. Phosphorylation at Ser129 may thus have a protective effect against neurotoxic asyn oligomers by preventing oligomer membrane binding and disruption of the cellular electrophysiological equilibrium. Importantly, these findings put a new complexion on experimental pharmaceutical interventions against POLO-2 kinase.

  4. Modos de trabalhar e de ser na reestruturação bancária

    Directory of Open Access Journals (Sweden)

    Grisci Carmem Ligia Iochins

    2004-01-01

    Full Text Available O artigo discute como a reestruturação produtiva do trabalho bancário afetou os modos de trabalhar e de ser dos trabalhadores de uma centenária instituição bancária pública que implementou Programas de Apoio à Demissão Voluntária como uma das novas ferramentas de gestão. Trata-se de um estudo de caso que investigou 104 trabalhadores dos estados do Rio Grande do Sul e de Santa Catarina que aderiram à terceira edição de um desses Programas, ocorrido na empresa em 2001, além de cinco gestores e três funcionários da área de Recursos Humanos da empresa diretamente envolvidos com os Programas ou com os desligados. A coleta de dados deu-se através de questionário, entrevistas individuais semi-estruturadas e fontes documentais. Os dados coletados foram submetidos à análise de conteúdo. Os resultados da pesquisa indicam que a reestruturação produtiva do trabalho bancário demarca a passagem de uma cultura de estabilidade e segurança para uma cultura de instabilidade e insegurança que afeta os modos de trabalhar e de ser dos bancários. O investimento que a empresa deseja, por parte dos sujeitos do trabalho diz, portanto, de uma mobilização subjetiva total e incondicional ao seu projeto e aos objetivos de lucratividade.

  5. Soldadura de metales disimilares por láser de CO2

    Directory of Open Access Journals (Sweden)

    Garciandía, F.

    1998-04-01

    Full Text Available The work carried out in CETENASA (Laser department in order to weld dissimilar metals is summarized. The involved metallic pair is M-35 and F-143, a high speed steel and a spring steel, respectively. Looking at the chemical composition of the involved alloys that will appear later, it can be easily understood the difficulty to obtain welded parts with structures metallurgicaly acceptable because of the high cracking degree that these materials show, specially M-35. The principles of a study which is being developed in the authors' laboratory and which shows some interesting CO2 laser possibilities are presented.

    En el presente documento se resumen los trabajos llevados a cabo en CETENASA (Dpto. Láser para la obtención de puntos de soldadura entre metales disimilares. El par metálico estudiado es M-35 y F-143, correspondientes a un acero rápido y un acero para muelles, respectivamente. Debido a las composiciones químicas de las aleaciones implicadas se comprende la dificultad para obtener soldaduras con estructuras aceptables, desde el punto de vista metalúrgico, dado el alto grado de fisuración que presentan estos materiales, especialmente el M-35. El presente trabajo es un avance de los primeros resultados encontrados dentro de una investigación más amplia, en la que se demuestran las posibilidades que presenta la soldadura con láser de CO2.

  6. “Falar de Mim é Fácil, Difícil é Ser Eu"

    Directory of Open Access Journals (Sweden)

    Érica Alessandra F. Aniceto

    2016-07-01

    Full Text Available No presente artigo, pretende-se verificar como alunos da Educação de Jovens e Adultos (EJA de uma escola localizada na periferia de Mariana – MG constroem sua identidade no site de relacionamentos Orkut. Na referida rede de relacionamentos, as relações cotidianas se mostram através da exposição do sujeito em variados níveis de visibilidade, em que as pessoas se revelam de acordo com a maneira que gostariam de ser vistas e respeitadas pela sociedade, buscando sua própria identidade nesse contexto virtual. Nessa construção intencional da identidade, permitida no mundo da Internet, o sujeito tem autonomia para elaborar e construir sua identidade da maneira que lhe convém. Lembrando que a linguagem não pode dissociar-se do contexto social em que funciona, pode-se afirmar que, com a intenção de interagir com a comunidade em que vivem, na tentativa de mostrar-se como parte dela, os referidos alunos de EJA apresentam nesse cenário virtual uma determinada identidade de grupo. Ao observar os perfis de três estudantes, concluímos, baseados na teoria interacionista de Goffman (2008, que, no momento em que o sujeito se apresenta diante dos outros, ele constrói a sua identidade de acordo com os valores reconhecidos e legitimados por determinada comunidade, numa tentativa de ser aceito por ela.

  7. La experiencia de ser cuidadora de un anciano con enfermedad crónica

    Directory of Open Access Journals (Sweden)

    Gabriela Aldana-González

    2011-01-01

    Full Text Available Objetivo: conocer la construcción de la experiencia de ser cuidador de un anciano con enfermedad crónico-degenerativa en mujeres de San Cristóbal Ecatepec, México. Método: investigación de corte cualitativo, con cuatro personas de sexo femenino todas ellas cuidadoras de ancianos con enfermedades crónico-degenerativas. Se utilizó la entrevista a profundidad como técnica para la recolección de datos. Los datos se analizaron a partir de ubicar categorías de análisis desde una orientación fenomenológica. La investigación se llevó a cabo en la ciudad de San Cristóbal Ecatepec, Estado de México, México, entre marzo y junio del 2008. Resultados: el rol de cuidador está asignado a las mujeres. La categoría que aquí se describe se refiere a la cotidianidad del cuidado. Los discursos nos permiten develar el conflicto al que se enfrentan las cuidadoras: la responsabilidad moral del cuidado al adulto mayor y la necesidad de desarrollar un proyecto de vida autónomo. Conclusiones: la experiencia de ser cuidadora se asume como una responsabilidad y un compromiso moral que tiene que cumplirse por encima del cuidado personal. Tiene relación con la cultura mexicana respecto a la construcción de género y familia.

  8. Smart SERS Hot Spots: Single Molecules Can Be Positioned in a Plasmonic Nanojunction Using Host-Guest Chemistry.

    Science.gov (United States)

    Kim, Nam Hoon; Hwang, Wooseup; Baek, Kangkyun; Rohman, Md Rumum; Kim, Jeehong; Kim, Hyun Woo; Mun, Jungho; Lee, So Young; Yun, Gyeongwon; Murray, James; Ha, Ji Won; Rho, Junsuk; Moskovits, Martin; Kim, Kimoon

    2018-03-01

    Single-molecule surface-enhanced Raman spectroscopy (SERS) offers new opportunities for exploring the complex chemical and biological processes that cannot be easily probed using ensemble techniques. However, the ability to place the single molecule of interest reliably within a hot spot, to enable its analysis at the single-molecule level, remains challenging. Here we describe a novel strategy for locating and securing a single target analyte in a SERS hot spot at a plasmonic nanojunction. The "smart" hot spot was generated by employing a thiol-functionalized cucurbit[6]uril (CB[6]) as a molecular spacer linking a silver nanoparticle to a metal substrate. This approach also permits one to study molecules chemically reluctant to enter the hot spot, by conjugating them to a moiety, such as spermine, that has a high affinity for CB[6]. The hot spot can accommodate at most a few, and often only a single, analyte molecule. Bianalyte experiments revealed that one can reproducibly treat the SERS substrate such that 96% of the hot spots contain a single analyte molecule. Furthermore, by utilizing a series of molecules each consisting of spermine bound to perylene bisimide, a bright SERS molecule, with polymethylene linkers of varying lengths, the SERS intensity as a function of distance from the center of the hot spot could be measured. The SERS enhancement was found to decrease as 1 over the square of the distance from the center of the hot spot, and the single-molecule SERS cross sections were found to increase with AgNP diameter.

  9. Predicting local recurrence following breast-conserving treatment: parenchymal signal enhancement ratio (SER) around the tumor on preoperative MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Young; Cho, Nariya; Koo, Hye Ryoung; Yun, Bo La; Bae, Min Sun; Moon, Woo Kyung [Dept. of Radiology, Seoul National Univ. Coll. of Medicine, Seoul National Univ. Hospital, Seoul (Korea, Republic of)], e-mail: river7774@gmail.com; Chie, Eui Kyu [Dept. of Radiation Oncology, Seoul National Univ. Coll. of Medicine, Seoul National Univ. Hospital, Seoul (Korea, Republic of)

    2013-09-15

    Background: The level of background parenchymal enhancement around tumor is known to be associated with breast cancer risk. However, there is no study investigating predictive power of parenchymal signal enhancement ratio (SER) around tumor for ipsilateral breast tumor recurrence (IBTR). Purpose: To investigate whether the breast parenchymal SER around the tumor on preoperative dynamic contrast-enhanced magnetic resonance imaging (MRI) is associated with subsequent IBTR in breast cancer patients who had undergone breast-conserving treatment. Material and Methods: Nineteen consecutive women (mean age, 44 years; range, 34-63 years) with breast cancer who developed IBTR following breast-conserving treatment and 114 control women matched for age, as well as T and N stages were included. We compared the clinicopathologic features of the two groups including nuclear grade, histologic grade, hormonal receptor status, human epidermal growth factor receptor-2 (HER-2) status, lymphovascular invasion, negative margin width, use of adjuvant therapy, and parenchymal SER around the tumor on preoperative DCE-MRI. The SER was measured on a slice showing the largest dimension of the tumor. Multivariate conditional logistic regression analysis was used to identify independent factors associated with IBTR. Results: In univariate analysis, ER negativity (odds ratio [OR] = 4.7; P = 0.040), PR negativity (OR = 4.0; P = 0.013), HER-2 positivity (OR = 3.6; P = 0.026), and a parenchymal SER greater than 0.53 (OR = 23.3; P = 0.011) were associated with IBTR. In multivariate analysis, ER negativity (OR = 3.8; P = 0.015) and a parenchymal SER greater than 0.53 (OR = 13.2; P = 0.040) on preoperative MRI were independent factors associated with IBTR. Conclusion: In addition to ER negativity, a higher parenchymal SER on preoperative MRI was an independent factor associated with subsequent IBTR in patients with breast cancer who had undergone breast-conserving treatment.

  10. Application of surface-enhanced Raman scattering (SERS) for the identification of anthraquinone dyes used in works of art

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Kui [ORNL; Leona, Marco [ORNL; Yan, Fei [ORNL; Wabuyele, Musundi B [ORNL; Vo Dinh, Tuan [ORNL

    2006-04-01

    Surface-enhanced Raman scattering (SERS) was investigated for applications in the analysis of anthraquinone dyes used in works of art. Two SERS procedures were developed and evaluated with three frequently used anthraquinone dyes, alizarin, carminic acid and lac dye. The first procedure involves coating a layer of silver nanoparticles directly on pieces of filter paper stained with the dyes of interest by thermal evaporation to induce SERS effect. In the second procedure, a SERS-active Ag-Al{sub 2}O{sub 3} substrate was prepared by spin-coating an alumina-nanoparticle layer onto a glass slide to provide the nanostructure of the substrate, followed by thermally evaporating a layer of silver nanoparticles on top of the alumina layer. Aliquots of dye solutions were delivered onto this substrate to be analyzed. Intense SERS spectra characteristic of alizarin, carminic acid and lac dye were obtained using both SERS procedures. The effects of two parameters, the concentration of the alumina suspension and the thickness of the silver nanoparticle layer on the performance of the Ag-Al{sub 2}O{sub 3} substrate were examined with alizarin as the model compound. Comparative studies were conducted between the Ag-Al{sub 2}O{sub 3} substrate and the SERS substrate prepared using Tollens reaction. The Ag-Al{sub 2}O{sub 3} substrate was shown to offer larger enhancement and improved reproducibility than the Tollens substrates. Finally, the potential applicability of the Ag-Al{sub 2}O{sub 3} substrate for the analysis of real artifact objects was illustrated by the identification of alizarin extracted from a small piece of textile dyed using traditional methods and materials. The limit of detection for alizarin was estimated to be 7 x 10{sup -15} g from tests performed on solutions of known concentration.

  11. Optimizing silver-capped silicon nanopillars to simultaneously realize macroscopic, practical-level SERS signal reproducibility and high enhancement at low costs

    DEFF Research Database (Denmark)

    Wu, Kaiyu; Rindzevicius, Tomas; Schmidt, Michael Stenbæk

    2017-01-01

    and show that the improved structures exhibit unrivalled macroscale SERS uniformities (RSD: ∼2.5% in millimeter scale, ∼7% in wafer scale) and reproducibility (RSD: ∼1.5% across 3 wafers), while at the same time exhibiting a very large average SERS enhancement factor of >108. The obtained SERS uniformity...

  12. Iodide-induced organothiol desorption and photochemical reaction, gold nanoparticle (AuNP) fusion, and SERS signal reduction in organothiol-containing AuNP aggregates

    Science.gov (United States)

    Gold nanoparticles (AuNPs) have been used extensively as surface-enhanced Raman spectroscopic (SERS) substrates for their large SERS enhancements and widely believed chemical stability. Presented is the finding that iodide can rapidly reduce the SERS intensity of the ligands, including organothiols ...

  13. High-adhesive superhydrophobic 3D nanostructured silver films applied as sensitive, long-lived, reproducible and recyclable SERS substrates

    Science.gov (United States)

    Wu, Yunwen; Hang, Tao; Komadina, Jason; Ling, Huiqin; Li, Ming

    2014-07-01

    Silver films with different morphologies were chemically deposited by controlling the bath composition. It is found that the wettability and surface enhanced Raman scattering (SERS) properties were closely connected with the surface morphology. Due to the perfect 3D morphology and the 3D electromagnetic field enhanced by three types of nanogaps distributed uniformly, the 3D microball/nanosheet (MN) silver film shows better SERS properties than those of 2D nanosheets (NSs) and nanoparticles (NPs). The MN silver film showed high adhesive superhydrophobic properties after an oxidation process without any functionalization. It can hold the liquid droplet and trace the target molecules in a rather small volume. The SERS properties of the oxidized MN substrate were enhanced remarkably compared to those of the freshly prepared substrate because of the concentrating effect of the superhydrophobicity. The as-prepared 3D MN silver substrate has also exhibited good performances in reproducibility and reutilization which makes it a promising substrate for molecule tracing.Silver films with different morphologies were chemically deposited by controlling the bath composition. It is found that the wettability and surface enhanced Raman scattering (SERS) properties were closely connected with the surface morphology. Due to the perfect 3D morphology and the 3D electromagnetic field enhanced by three types of nanogaps distributed uniformly, the 3D microball/nanosheet (MN) silver film shows better SERS properties than those of 2D nanosheets (NSs) and nanoparticles (NPs). The MN silver film showed high adhesive superhydrophobic properties after an oxidation process without any functionalization. It can hold the liquid droplet and trace the target molecules in a rather small volume. The SERS properties of the oxidized MN substrate were enhanced remarkably compared to those of the freshly prepared substrate because of the concentrating effect of the superhydrophobicity. The as

  14. Functionalized Au@Ag-Au nanoparticles as an optical and SERS dual probe for lateral flow sensing.

    Science.gov (United States)

    Bai, Tingting; Wang, Meng; Cao, Min; Zhang, Juan; Zhang, Kangzhen; Zhou, Ping; Liu, Zhengxia; Liu, Ying; Guo, Zhirui; Lu, Xiang

    2018-02-14

    Lateral flow assay strips (LFASs) with Au nanoparticles (NPs) have been widely used as a probe for biomarkers in point-of-care testing; however, there still remain challenges in detection sensitivity and quantitative analysis. In this study, we developed a surface-enhanced Raman scattering (SERS)-based LFAS for quantitative analysis of a biomarker in the low concentration range. Moreover, apart from conventional Au NPs, three other types of citrate-capped Au-Ag bimetallic NPs: Au core with Ag shell NPs (Au@Ag NPs), rattle-like Au core in Ag-Au shell NPs (Au@Ag-Au NPs) and Ag-Au NPs were prepared and functionalized, and their solution-based SERS activities were comprehensively studied by experimental measurement and theoretical analysis. The results clearly indicated that the citrate-capped Au@Ag-Au NPs exhibited the highest SERS activity among the probes tested. Au@Ag-Au NPs were used as both optical and SERS probes in a SERS-based LFAS. In the presence of the analyte at high concentrations, a purple color appeared in the test zone. Highly sensitive and quantitative analysis was realized by measurement of SERS signals from the test lines. One of the most specific markers for cardiac injury, cardiac troponin I (cTnI), was chosen as the detection model. The detection limit of the SERS-based LFAS for cardiac troponin I was 0.09 ng/mL, lowered by nearly 50 times compared with visual results, and could be further lowered by optimization. These results demonstrated that the SERS-based LFAS using citrate-capped Au@Ag-Au NPs as probes can be a powerful tool for highly sensitive and quantitative detection of biomarkers. Graphical abstract A surface-enhanced Raman scattering (SERS)-based lateral flow assay strip using rattle-like Au core in Ag-Au shell (Au@Ag-Au) nanoparticles as probes was developed for quantitative analysis of a biomarker, with a detection limit nearly 50 times lower than that of visual assessment. C control line, T test line.

  15. Effective SERS-active substrates composed of hierarchical micro/nanostructured arrays based on reactive ion etching and colloidal masks.

    Science.gov (United States)

    Zhang, Honghua; Liu, Dilong; Hang, Lifeng; Li, Xinyang; Liu, Guangqiang; Cai, Weiping; Li, Yue

    2016-09-30

    A facile route has been proposed for the fabrication of morphology-controlled periodic SiO2 hierarchical micro/nanostructured arrays by reactive ion etching (RIE) using monolayer colloidal crystals as masks. By effectively controlling the experimental conditions of RIE, the morphology of a periodic SiO2 hierarchical micro/nanostructured array could be tuned from a dome-shaped one to a circular truncated cone, and finally to a circular cone. After coating a silver thin layer, these periodic micro/nanostructured arrays were used as surface-enhanced Raman scattering (SERS)-active substrates and demonstrated obvious SERS signals of 4-Aminothiophenol (4-ATP). In addition, the circular cone arrays displayed better SERS enhancement than those of the dome-shaped and circular truncated cone arrays due to the rougher surface caused by physical bombardment. After optimization of the circular cone arrays with different periodicities, an array with the periodicity of 350 nm exhibits much stronger SERS enhancement and possesses a low detection limit of 10(-10) M 4-ATP. This offers a practical platform to conveniently prepare SERS-active substrates.

  16. O cuidado de enfermagem: uma visão fenomenológica do ser leucêmico

    Directory of Open Access Journals (Sweden)

    Catarina Aparecida Sales

    1999-06-01

    Full Text Available Este trabalho é uma investigação sobre o cuidado de enfermagem na visão do ser leucêmico. A pesquisadora parte de inquietações emergidas em seu cotidiano enquanto, enfermeira assistencial e docente de enfermagem, buscando a apreender o sentido do cuidado no existir diário do ser leucêmico, enquanto um ser-no-mundo. Apresenta uma reflexão sobre o caminho a ser percorrido, e encontra na pesquisa qualitativa fenomenológica, no enfoque hermenêutico, fundamentado no pensar de Martin Heidegger, o método para desvelar o velado no discurso dos sujeitos, demonstrando que o ser leucêmico percebe o cuidado de enfermagem como: forma inautêntica de estar-com, assistir de forma diferenciada, paciência e compreensão e forma autêntica de estar-com. Ao desvelar o sentido emergido nos discursos, a pesquisadora percebe-se re-aprendendo a cuidar, através da linguagem dos sujeitos investigados.

  17. Use of Single-Layer g-C3N4/Ag Hybrids for Surface-Enhanced Raman Scattering (SERS).

    Science.gov (United States)

    Jiang, Jizhou; Zou, Jing; Wee, Andrew Thye Shen; Zhang, Wenjing

    2016-09-30

    Surface-enhanced Raman scattering (SERS) substrates with high activity and stability are desirable for SERS sensing. Here, we report a new single atomic layer graphitic-C 3 N 4 (S-g-C 3 N 4 ) and Ag nanoparticles (NPs) hybrid as high-performance SERS substrates. The SERS mechanism of the highly stable S-g-C 3 N 4 /Ag substrates was systematically investigated by a combination of experiments and theoretical calculations. From the results of XPS and Raman spectroscopies, it was found that there was a strong interaction between S-g-C 3 N 4 and Ag NPs, which facilitates the uniform distribution of Ag NPs over the edges and surfaces of S-g-C 3 N 4 nanosheets, and induces a charge transfer from S-g-C 3 N 4 to the oxidizing agent through the silver surface, ultimately protecting Ag NPs from oxidation. Based on the theoretical calculations, we found that the net surface charge of the Ag atoms on the S-g-C 3 N 4 /Ag substrates was positive and the Ag NPs presented high dispersibility, suggesting that the Ag atoms on the S-g-C 3 N 4 /Ag substrates were not likely to be oxidized, thereby ensuring the high stability of the S-g-C 3 N 4 /Ag substrate. An understanding of the stability mechanism in this system can be helpful for developing other effective SERS substrates with long-term stability.

  18. Surface-enhanced vibrational spectroscopy of B vitamins: what is the effect of SERS-active metals used?

    Science.gov (United States)

    Kokaislová, A; Matějka, P

    2012-05-01

    Surface-enhanced Raman scattering (SERS) spectroscopy and surface-enhanced infrared absorption (SEIRA) spectroscopy are analytical tools suitable for the detection of small amounts of various analytes adsorbed on metal surfaces. During recent years, these two spectroscopic methods have become increasingly important in the investigation of adsorption of biomolecules and pharmaceuticals on nanostructured metal surfaces. In this work, the adsorption of B-group vitamins pyridoxine, nicotinic acid, folic acid and riboflavin at electrochemically prepared gold and silver substrates was investigated using Fourier transform SERS spectroscopy at an excitation wavelength of 1,064 nm. Gold and silver substrates were prepared by cathodic reduction on massive platinum targets. In the case of gold substrates, oxidation-reduction cycles were applied to increase the enhancement factor of the gold surface. The SERS spectra of riboflavin, nicotinic acid, folic acid and pyridoxine adsorbed on silver substrates differ significantly from SERS spectra of these B-group vitamins adsorbed on gold substrates. The analysis of near-infrared-excited SERS spectra reveals that each of B-group vitamin investigated interacts with the gold surface via a different mechanism of adsorption to that with the silver surface. In the case of riboflavin adsorbed on silver substrate, the interpretation of surface-enhanced infrared absorption (SEIRA) spectra was also helpful in investigation of the adsorption mechanism.

  19. Intracellular surface-enhanced Raman scattering (SERS) with thermally stable gold nanoflowers grown from Pt and Pd seeds

    KAUST Repository

    Song, Hyon Min

    2013-01-01

    SERS provides great sensitivity at low concentrations of analytes. SERS combined with near infrared (NIR)-resonant gold nanomaterials are important candidates for theranostic agents due to their combined extinction properties and sensing abilities stemming from the deep penetration of laser light in the NIR region. Here, highly branched gold nanoflowers (GNFs) grown from Pd and Pt seeds are prepared and their SERS properties are studied. The growth was performed at 80°C without stirring, and this high temperature growth method is assumed to provide great shape stability of sharp tips in GNFs. We found that seed size must be large enough (>30 nm in diameter) to induce the growth of those SERS-active and thermally stable GNFs. We also found that the addition of silver nitrate (AgNO3) is important to induce sharp tip growth and shape stability. Incubation with Hela cells indicates that GNFs are taken up and reside in the cytoplasm. SERS was observed in those cells incubated with 1,10-phenanthroline (Phen)-loaded GNFs. This journal is © 2013 The Royal Society of Chemistry.

  20. Towards SERS based applications in food analytics: Lipophilic sensor layers for the detection of Sudan III in food matrices

    Energy Technology Data Exchange (ETDEWEB)

    Jahn, Martin; Patze, Sophie [Friedrich-Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena (Germany); Leibniz Institute of Photonic Technology (IPHT) Jena, Albert-Einstein-Strasse 9, 07745 Jena (Germany); Bocklitz, Thomas [Friedrich-Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena (Germany); Weber, Karina [Friedrich-Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena (Germany); Leibniz Institute of Photonic Technology (IPHT) Jena, Albert-Einstein-Strasse 9, 07745 Jena (Germany); Cialla-May, Dana, E-mail: dana.cialla-may@uni-jena.de [Friedrich-Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena (Germany); Leibniz Institute of Photonic Technology (IPHT) Jena, Albert-Einstein-Strasse 9, 07745 Jena (Germany); Popp, Jürgen [Friedrich-Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena (Germany); Leibniz Institute of Photonic Technology (IPHT) Jena, Albert-Einstein-Strasse 9, 07745 Jena (Germany)

    2015-02-20

    Highlights: • A lipophilic sensor layer was applied to enzymatically grown SERS substrates. • Sudan III molecules could be detected in presence of water-insoluble competitors. • The carcinogenic food dye Sudan III was detected in a relevant concentration range. • Multivariate statistics allows quantitative measurements of Sudan III. • Sudan III contaminations were successfully detected out of spiked paprika powder. - Abstract: Food safety is a topic of great importance for our society which places high demands on analytical methods. Surface enhanced Raman spectroscopy (SERS) meets the requirements for a rapid, sensitive and specific detection technique. The fact that metallic colloids, one of the most often used SERS substrates, are usually prepared in aqueous solution makes the detection of water-insoluble substances challenging. In this paper we present a SERS based approach for the detection of water-insoluble molecules by applying a hydrophobic surface modification onto the surface of enzymatic generated silver nanoparticles. By this approach the detection of the illegal water-insoluble food dyes, such as Sudan III in presence of riboflavin, as water-soluble competitor, is possible. Moreover, we demonstrate the usability of this kind of SERS substrates for determination of Sudan III out of spiked paprika extracts.