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. ¿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.

  3. 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.

  4. Realidad aumentada, realidad virtual, interfaces avanzadas, juegos educativos

    OpenAIRE

    Abásolo Guerrero, María José; Mitaritonna, Alejandro; Bouciguez, María José; Encina, Natalia; Vicenzi, Mario; De Giusti, Armando Eduardo; Naiouf, Marcelo; Giacomantone, Javier; Manresa Yee, Cristina

    2016-01-01

    La línea de investigación y desarrollo presentada consiste en estudiar, desarrollar y evaluar aplicaciones de realidad virtual, realidad aumentada e interfaces avanzadas. Uno de los principales objetivos es la formación de recursos humanos y fortalecimiento de la investigación mediante el trabajo intergrupal entre diferentes instituciones nacionales y extranjeras. El proyecto concluido Formación de Recursos Humanos e Investigación en Visión e Informática Gráfica (FRIVIG) de la AECI posibilitó...

  5. La salud sexual y reproductiva como área para desarrollar la enfermería de práctica avanzada

    Directory of Open Access Journals (Sweden)

    Jhon Henry Osorio-Castaño

    2017-07-01

    Full Text Available Introducción: la enfermería de práctica avanzada implica el desarrollo de nuevos roles en la formación y práctica enfermera a partir del nivel de maestría, cuya esencia es la ampliación de los dominios de actuación con autonomía e independencia. Metodología: revisión temática. Se realizó búsqueda en bases de datos Lilacs, Pubmed y EBSCO. Se utilizó como palabra clave enfermería de práctica avanzada, se limitó a los artículos publicados desde el año 2010 hasta el año 2016 en idioma inglés, español y portugués. Análisis: Resultados: La ley 266 de 1996 define la enfermería como como una profesión liberal. De otro lado, varias políticas, planes y programas en salud sexual y reproductiva manifiestan la necesidad de personal formado en estas temáticas y en componentes adicionales como la investigación y el liderazgo. Una oportunidad para el desarrollo de la autonomía y la independencia en enfermería es la práctica avanzada que favorezca la ampliación de los dominios de desempeño profesional y ayude a visibilizar el quehacer enfermero. Conclusión: la salud sexual y reproductiva puede ser un nicho propicio para el desarrollo de la enfermería de práctica avanzada en el marco de la atención primaria en salud siempre y cuando exista un marco político y regulatorio.

  6. 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.

  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. Plan anual de mercadeo para el aumento de los clientes y el mejoramiento de las ventas en la comercialización de tecnologías avanzadas para purificación ambienta

    OpenAIRE

    Colmenares Pareja, Ana María

    2013-01-01

    La División Ambiente, basada en el proceso de innovación y creada con el fin de motivar el crecimiento y la diversificación de Proquimes, se dedica a la comercialización de tecnologías avanzadas para purificación ambiental, ofreciendo soluciones integrales, innovadoras y confiables para garantizar la inocuidad y obtener un entorno seguro. Como ventajas competitivas se identifican el ser pionero en el mercado industrial y contar con la representación exclusiva en Colombia para la distribución ...

  9. Diabetes mellitus en el paciente con enfermedad renal avanzada

    Directory of Open Access Journals (Sweden)

    R. Verner Codoceo, Dr.

    2010-07-01

    Full Text Available La diabetes mellitus 2 (DM 2 y la enfermedad renal crónica (ERC son considerados problemas de salud pública a nivel mundial. Los pronósticos de ambas enfermedades están estrechamente relacionados, por lo que las acciones terapéuticas son complementarias. Un buen control glicémico revierte las alteraciones renales en sus etapas iniciales disminuyendo el deterioro microangiopático ya su vez el intento de obtener un control óptimo de glicemias requiere conocer y tratar las alteraciones provocadas por el ambiente urémico. Es muy importante considerar la existencia de cambios en la interpretación de los análisis de laboratorio, cambios en la farmacocinética y farmacodinamia de los medicamentos hipoglicemiantes e insulinas y finalmente la existencia de dificultades para realizar ejercicios y administrar una alimentación adecuada. Los esquemas de hipoglicemiantes utilizados, tanto medicamentos orales como insulinas, deben ser cuidadosamente personalizados. Se debe evitar la indicación de medicamentos de excreción renal exclusiva por el riesgo de hipoglicemias. Tanto las insulinas análogas como convencionales pueden ser administradas, con precaución en su dosificación y reconociendo la necesidad de un estricto automonitoreo de glicemia digital.

  10. Influencia de la consulta de enfermedad renal crónica avanzada en la elección de modalidad de terapia renal sustitutiva

    Directory of Open Access Journals (Sweden)

    Carmen Caro Domínguez

    Full Text Available Introducción: La enfermedad renal crónica constituye un problema de salud pública por su elevada incidencia y prevalencia, importante morbimortalidad y coste asistencial. Un aspecto fundamental para el paciente es la elección de modalidad de terapia sustitutiva renal. En este sentido, la consulta de enfermedad renal crónica avanzada o prediálisis, puede jugar un papel fundamental. Objetivo: Conocer producción científica sobre la influencia de la consulta de enfermedad renal crónica avanzada en la elección de modalidad de diálisis por parte del paciente. Metodología: Revisión bibliográfica para la que se realizaron búsquedas en las bases de datos de PubMed, Scielo, Science Direct, Proquest y Google Académico. Se analizaron los artículos que trataban la consulta prediálisis, variables que influyeran en la elección de modalidad de diálisis y satisfacción del paciente. Resultados: Se han revisado 25 artículos publicados en los años 2002-2014, de diseño observacional descriptivo y de cohortes. Se ha encontrado relación en la elección de las técnicas domiciliarias con la existencia de un programa de educación prediálisis, la información que ofrece enfermería, la entrada programada en diálisis, menor edad, menor comorbilidad y factores socioeconómicos o estructurales. Conclusion: Los factores que favorecen la elección de las técnicas de diálisis domiciliarias son la existencia de consulta de enfermedad renal crónica avanzada y la referencia oportuna del paciente a dicha consulta, ser joven, menor comorbilidad y la necesidad de contención de costes. Esta elección se ve perjudicada por factores estructurales. Las terapias domiciliarias producen mayor satisfacción en los pacientes.

  11. 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.

  12. Ecuaciones constitutivas avanzadas para describir el comportamiento termoviscoplástico de metales FCC

    OpenAIRE

    Pereira Valadés, Daniel

    2011-01-01

    En este proyecto de fin de carrera se ha llevado a cabo el estudio y proposición de ecuaciones constitutivas avanzadas que permitan describir con exactitud el comportamiento termoviscoplástico de metales FCC. Este estudio es de vital importancia para entender el proceso que tiene lugar en estos metales bajo condiciones de carga dinámicas, siempre en deformación plástica. La utilidad del estudio reside en la gran cantidad de procesos industriales que se llevan a cabo con este tipo de solicitac...

  13. Toward practical SERS sensing

    Science.gov (United States)

    Zhao, Yiping

    2012-06-01

    Since its discovery more than 30 years ago, surface-enhanced Raman scattering (SERS) has been recognized as a highly sensitive detection technique for chemical and biological sensing and medical diagnostics. However, the practical application of this remarkably sensitive technique has not been widely accepted as a viable diagnostic method due to the difficulty in preparing robust and reproducible substrates that provide maximum SERS enhancement. Here, we demonstrate that the aligned silver nanorod (AgNR) array substrates engineered by the oblique angle deposition method are capable of providing extremely high SERS enhancement factors (>108). The substrates are large area, uniform, reproducible, and compatible with general microfabrication process. The enhancement factor depends strongly on the length and shape of the Ag nanorods and the underlying substrate coating. By optimizing AgNR SERS substrates, we show that SERS is able to detect trace amount of toxins, virus, bacteria, or other chemical and biological molecules, and distinguish different viruses/bacteria and virus/bacteria strains. The substrate can be tailored into a multi-well chip for high throughput screening, integrated into fiber tip for portable sensing, incorporated into fluid/microfluidic devices for in situ real-time monitoring, fabricated onto a flexible substrate for tracking and identification, or used as on-chip separation device for ultra-thin layer chromatography and diagnostics. By combining the unique SERS substrates with a handheld Raman system, it can become a practical and portable sensor system for field applications. All these developments have demonstrated that AgNR SERS substrates could play an important role in the future for practical clinical, industrial, defense, and security sensing applications.

  14. Security effectiveness review (SER)

    International Nuclear Information System (INIS)

    Kouprianova, I.; Ek, D.; Showalter, R.; Bergman, M.

    1998-01-01

    As part of the on-going DOE/Russian MPC and A activities at the Institute of Physics and Power Engineering (IPPE) and in order to provide a basis for planning MPC and A enhancements, an expedient method to review the effectiveness of the MPC and A system has been adopted. These reviews involve the identification of appropriate and cost-effective enhancements of facilities at IPPE. This effort requires a process that is thorough but far less intensive than a traditional vulnerability assessment. The SER results in a quick assessment of current and needed enhancements. The process requires preparation and coordination between US and Russian analysts before, during, and after information gathering at the facilities in order that the analysis is accurate, effective, and mutually agreeable. The goal of this paper is to discuss the SER process, including the objectives, time scale, and lessons learned at IPPE

  15. SERS Engineering Collaboration

    Science.gov (United States)

    2012-06-01

    laser beam. In the second approach, a pulsed laser was used to texture a silicon wafer to form sharp features. Silver was evaporated onto the wafer...orders of magnitude larger than that measured on a gold nanoparticle array on a glass substrate. The largest SERS enhancement for a silver device was...surface plasmons," Yizhuo Chu and Kenneth B. Crozier, Optics Letters vol. 34, 244 (2009) K3. "Gold nanorings as substrates for surface-enhanced Raman

  16. 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.

  17. Quiero ser citado

    Directory of Open Access Journals (Sweden)

    Leonardo Romero

    2011-05-01

    Full Text Available Después de varios años de ser editor, muchos de mis jefes confunden la revista con el editor, y es común oír cosas como “conferencia a cargo de la revista” o en conversaciones se dirijan a mí para decir “y porque no te citan”, refiriéndose al motivo porqué la Rev peru biol. no es citada por otros trabajos. Aprovechando ese desquicio, en los siguientes párrafos encarnare a la revista y al editor, en la fusión mágica en la que algunos de mis jefes me imaginan.

  18. La edad materna avanzada como elemento favorecedor de complicaciones obstétricas y del nacimiento

    Directory of Open Access Journals (Sweden)

    Jorge Manuel Balestena Sánchez

    2015-10-01

    Full Text Available Introducción: el aumento actual del embarazo en mujeres añosas provoca un riesgo superior para la mujer y su feto. Objetivo: evaluar la edad materna avanzada como factor de complicaciones obstétricas y del nacimiento. Material y método: se efectuó una investigación observacional, retrospectiva, transversal y analítica en el Hospital General Docente "Abel Santamaría Cuadrado" de Pinar del Río entre 2012 y 2013. El universo de estudio fueron la totalidad de gestantes que ingresaron en el período estudiado. La muestra se formó con gestantes añosas (grupo estudio 360 pacientes y un grupo control (720 pacientes con embarazadas entre 25 y 30 años; ambos se escogieron por muestreo intencionado. Se resumieron las variables cualitativas mediante frecuencias absolutas y relativas porcentuales. Se utilizaron las pruebas de ji cuadrado, Odd Ratio. El intervalo de confianza para el Odd Ratio al 95%. Resultados: hubo un predominio de la embarazada con partos anteriores (92.8%, la normopeso (68.9%, el 34.4% padecían alguna enfermedad crónica, siendo la principal la hipertensión arterial; la anemia durante el embarazo estuvo presente en el 34.4%, el 88.3% parieron a término, de modo espontáneo; además preponderó la cesárea con un (52.2%. La morbilidad intraparto se manifestó en el 13.1%, mientras la puerperal en el 26.7%. Hubo una elevada asociación del embarazo prolongado con la enfermedad hipertensiva, el oligoamnios y la anemia (p < 0,001, también con la inducción del parto (p < 0,001 y la cesárea (p < 0,001, así como con la morbilidad puerperal (p < 0,001. Conclusiones: la edad materna avanzada es un factor de riesgo a tener en cuenta durante el proceso de la gestación y el nacimiento.

  19. PROCESOS FOTOSENSIBILIZADOS MEDIADOS POR PRODUCTOS DE GLICACION AVANZADA. EFECTOS SOBRE SISTEMAS DE IMPORTANCIA BIOLOGICA EN EL LENTE OCULAR.

    OpenAIRE

    FUENTEALBA PATIÑO, DENIS ALBERTO; FUENTEALBA PATIÑO, DENIS ALBERTO

    2009-01-01

    La reacción no enzimática de proteínas con azúcares (glicación o reacción de Maillard), lleva a la formación de una gran variedad de compuestos denominados productos de glicación avanzada (AGEs) y su acumulación en sistemas biológicos está relacionada con 194p.

  20. 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.

  1. 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.

  2. 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.

  3. 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...

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

    Directory of Open Access Journals (Sweden)

    Rebeca Wong

    2003-01-01

    Full Text Available 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.

  6. 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

  7. 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.

  8. ser en ortodoncia

    OpenAIRE

    Ruíz-Esculpi, María; Ricse-Chaupis, Estela; Villanueva-Vega, Judith; Torres-Maita, Liz

    2014-01-01

    La primera aplicación del láser en un diente fue realizada en 1965. Desde entonces ha presentado una constante evolución y desarrollo. La tecnología láser permite realizar procedimientos en tejidos duros y blandos, pudiendo ser utilizado con las siguientes finalidades: como prevención de la desmineralización, en la adhesión y remoción de brackets, en la reducción del dolor producto del movimiento dental, en la reparación ósea después de la expansión, en diversas cirugías y otras aplicaciones ...

  9. Evaluación agronómica de líneas avanzadas de fríjol voluble Phaseolus vulgaris L. en Paipa, Boyacá

    Directory of Open Access Journals (Sweden)

    Diana Katherine Ríos

    2014-06-01

    Full Text Available En Boyacá la oferta de germoplasma de frijol mejorado es baja. El objetivo de este estudio fue evaluar el comportamiento agronómico de 18 líneas avanzadas volubles de frijol, procedentes del CIAT. Se utilizó el diseño bloques completos al azar, con tres repeticiones, incluyendo Bola Roja, Bolívar y Cargamanto como testigos. Se evaluó días a floración, vigor de crecimiento, días a madurez, incidencia de enfermedades, número de vainas/planta, número de granos/vaina, peso de 100 granos y rendimiento. Los genotipos MAC27, MAC13, MBC26, MBC28 y MBC37 no se diferenciaron del Cargamanto pero sí mostraron ser más precoces que Bola Roja y Bolívar. En días a madurez MAC27 y MBC39 fueron más tempranos que los testigos. Todos los genotipos se comportaron como resistentes a enfermedades, excepto MBC30 que resultó susceptible a Uromyces phaseoli y MBC33 a Phoma exigua. En número de vainas por planta, número de granos por vaina, peso de 100 semillas y rendimiento se destacaron MAC27 y LAS399, sin diferencia significativa frente a Cargamanto pero si superando a Bola Roja y Bolívar. Pese al efecto de las heladas en la fase final del ciclo, LAS399, MAC27 y Cargamanto produjeron rendimientos de 1300, 1038 y 950 kg/ha, respectivamente, mostrando las ventajas de su precocidad, en comparación a Bola Roja y Bolívar que son tardíos. Se concluye que LAS399 y MAC27, por su alta precocidad y resistencia a patógenos, son las líneas más promisorias para continuar la evaluación respecto a la posibilidad de ampliar la oferta de germoplasma de frijol voluble en Boyacá.

  10. 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.

  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. SERS sensors for DVD platform

    DEFF Research Database (Denmark)

    Brøgger, Anna Line

    This Ph.D. thesis explores the engineering of a portable sensor system for detection of rare and small molecules. The Ph.D. project is part of the research project 'Multi-Sensor DVD platform' (MUSE), aiming to integrate different sensors on a rotating disc. The sensors are chosen to complement each...... other, creating more reliable and stable results for the end user. The rotating disc comprises microfluidic channels, which can be utilized for handling and manipulating liquid samples such as blood or water. The focus of this Ph.D. thesis, is on the integration of one specific sensor on a rotating disc....... The sensor is based upon surface enhanced Raman spectroscopy (SERS), which detects molecular vibrations. The aim of this thesis is to cover the different aspects of the sensor system. SERS substrates, consisting of nanopillars with gold or silver caps on top, have been fabricated by standard micro and nano...

  13. 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

  14. Tuning SERS for living erythrocytes

    DEFF Research Database (Denmark)

    Brazhe, Nadezda; Parshina, E.Y.; Khabanova, V.V.

    2013-01-01

    Surface-enhanced Raman spectroscopy (SERS) is a unique technique to study submembrane hemoglobin (Hbsm) in erythrocytes. We report the detailed design of SERS experiments on living erythrocytes to estimate dependence of the enhancemen t factor for main Raman bands of Hbsm on silver nanoparticle (Ag......NP) properties. We demonstrate that the enhancement factor for 4/A1g, 10/B1g and A2g Raman bands of Hbsm varies from 105 to 107 under proposed experimental conditions with 473 nm laser excitation. For the first time we show that the enhancement of Raman scattering increases with the increase in the relative...... between small AgNPs and Hbsm and, consequently, leads to the higher enhancement of Raman scattering of Hbsm. The enhancement of higher wavenumber bands 10/B1g and A2g is more sensitive to AgNPs' size and the relative amount of small AgNPs than the enhancement of the lower wavenumber band 4/A1g. This can...

  15. por láser

    Directory of Open Access Journals (Sweden)

    Mayra Garcimuño

    2013-01-01

    Full Text Available En el presente trabajo, la técnica Espectroscopia de plasmas producidos por láser (Laser-induced breakdown spectroscopy –LIBS– se aplicó a la determinación cuan- titativa de Na en agua natural dulce, de interés en agricultura para el estudio de la alcalinidad de aguas de regadío. Para efectuar el análisis, se prepararon soluciones con concentraciones conocidas del analito, se mezclaron con óxido de calcio y se compactaron en pastillas sólidas. Los plasmas se produjeron en aire a presión atmos- férica utilizando un láser pulsado Nd:YAG. Se construyó una curva de calibración y se calculó el límite de detección. Se analizaron muestras de agua natural y los resultados se compararon con los obtenidos mediante espectroscopia de absorción atómica. Se demostró la factibilidad del método para la determinación de Na en agua natural dulce.

  16. 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.

  17. 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.

  18. 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...

  19. 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...

  20. 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.

  1. 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.

  2. Achieving optimal SERS through enhanced experimental design.

    Science.gov (United States)

    Fisk, Heidi; Westley, Chloe; Turner, Nicholas J; Goodacre, Royston

    2016-01-01

    One of the current limitations surrounding surface-enhanced Raman scattering (SERS) is the perceived lack of reproducibility. SERS is indeed challenging, and for analyte detection, it is vital that the analyte interacts with the metal surface. However, as this is analyte dependent, there is not a single set of SERS conditions that are universal. This means that experimental optimisation for optimum SERS response is vital. Most researchers optimise one factor at a time, where a single parameter is altered first before going onto optimise the next. This is a very inefficient way of searching the experimental landscape. In this review, we explore the use of more powerful multivariate approaches to SERS experimental optimisation based on design of experiments and evolutionary computational methods. We particularly focus on colloidal-based SERS rather than thin film preparations as a result of their popularity. © 2015 The Authors. Journal of Raman Spectroscopy published by John Wiley & Sons, Ltd.

  3. 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.

  4. 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

  5. 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 ...

  6. SERS Technique for Rapid Bacterial Screening

    Science.gov (United States)

    This study reports the feasibility of citrate-reduced colloidal silver SERS for differentiating E. coli, Listeria, and Salmonella. FT-Raman and SERS spectra of both silver colloids and colloid-K3PO4 mixtures were collected and analyzed to evaluate the reproducibility and stability of silver colloids...

  7. Engineering Metal Nanostructure for SERS Application

    Directory of Open Access Journals (Sweden)

    Yanqin Cao

    2013-01-01

    Full Text Available Surface-enhanced Raman scattering (SERS has attracted great attention due to its remarkable enhancement and excellent selectivity in the detection of various molecules. Noble metal nanomaterials have usually been employed for producing substrates that can be used in SERS because of their unique local plasma resonance. As the SERS enhancement of signals depends on parameters such as size, shape, morphology, arrangement, and dielectric environment of the nanostructure, there have been a number of studies on tunable nanofabrication and synthesis of noble metals. In this work, we will illustrate progress in engineering metallic nanostructures with various morphologies using versatile methods. We also discuss their SERS applications in different fields and the challenges.

  8. 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

  9. SERS-Active Nanoinjector for Intracellular Spectroscopy

    Science.gov (United States)

    Vitol, Elina; Orynbayeva, Zulfiya; Bouchard, Michael; Azizkhan-Clifford, Jane; Friedman, Gary; Gogotsi, Yury

    2009-03-01

    We developed a multifunctional nanopipette which allows simultaneous cell injection and intacellular surface-enhanced Raman spectroscopy (SERS) analysis. SERS spectra contain the characteristic frequencies of molecular bond vibrations. This is a unique method for studying cell biochemistry and physiology on a single organelle level. Unlike the fluorescence spectroscopy, it does not require any specific staining. The principle of SERS is based on very large electromagnetic field enhancement localized around a nano-rough metallic surface. Gold colloids are widely used SERS substrates. Previously, the colloidal nanoparticles were introduced into a cell by the mechanism of endocytosis. The disadvantage of this method is the uncontrollable aggregation and distribution of gold nanoparticles inside a cell which causes a significant uncertainty in the origin of the acquired data. At the same time, the nanoparticle uptake is irreversible. We present a SERS-active nanoinjector, coated with gold nanoparticles, which enables selective signal acquisition from any point-of-interest inside a cell. The nanoinjector provides a highly localized SERS signal with sub-nanometer resolution in real time.

  10. 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

  11. 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.

  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. 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.

  14. 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

  15. 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...

  16. 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...

  17. 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.

  18. Gender inequalities in health among older Brazilian adults Desigualdades en función del género entre adultos brasileños de edad avanzada

    Directory of Open Access Journals (Sweden)

    Sandhi Maria Barreto

    2004-08-01

    Full Text Available OBJECTIVE: To investigate gender differences among older Brazilians in their health status and their use of health services. METHODS: Participants were individuals aged 60 years and older included in a national household survey conducted in Brazil in 1998. Data were analyzed by multiple logistic regression, taking into account the design effect due to multistage sampling. RESULTS: There were differences in the health and living conditions of older men and older women that were not explained by age or place of residence. Older women had worse indicators of schooling and personal income but better indicators of housing standards and per capita household income. The older women also reported more chronic diseases, had poorer indicators of independence and physical mobility, sought health services more often, and reported more medical visits in the previous year. Despite their apparent worse health conditions, elderly women in urban areas had lower hospitalization rates in the previous year (odds ratio = 0.89; 95% confidence interval, 0.82­0.96 than did elderly men in urban areas. CONCLUSIONS: Our results indicate that among older Brazilians there are gender inequalities in health that cannot be explained by age and place of residence. The findings raise questions on how health, socioeconomic, and cultural factors influence gender patterns of seeking and using health care in later life in the country. As pressures on health care and health funding increase in Brazil as a result of the aging of the population, there is a need to take a gender perspective into account.OBJETIVO: Investigar las diferencias halladas en función del género en el estado de salud y en el uso de servicios de salud en personas brasileñas de edad avanzada. MÉTODOS: Los participantes fueron personas de 60 años de edad o más que habían sido incluidas en una encuesta domiciliaria nacional realizada en el Brasil en 1998. Los datos se analizaron mediante regresión log

  19. Acerca de tres dimensiones del ser humano

    OpenAIRE

    Fúnez, Rubén

    2007-01-01

    El autor resume las ideas importantes del libro "Tres dimensiones del ser humano", se pregunta por la importancia del planteamiento zubiriano, tanto para la historia de la filosofía, como para la situación que actualmente nos ha tocado vivir.

  20. 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.

  1. Electrodeposited Silver Nanoparticles Patterned Hexagonally for SERS

    International Nuclear Information System (INIS)

    Gu, Geun Hoi; Lee, Sue Yeone; Suh, Jung Sang

    2010-01-01

    We have fabricated hexagonally patterned silver nanoparticles for surface-enhanced Raman scattering (SERS) by electrodepositing silver on the surface of an aluminum plate prepared by completely removing the oxide from anodic aluminum oxide (AAO) templates. Even after completely removing the oxide, well-ordered hexagonal patterns, similar to the shape of graphene, remained on the surface of the aluminum plate. The borders of the hexagonal pattern protruded up to form sorts of nano-mountains at both the sides and apexes of the hexagon, with the apexes protruding even more significantly than the sides. The aluminum plate prepared by completely removing the oxide has been used in the preparation of SERS substrates by sputter-coating of gold or silver on it. Instead of sputter-coating, here we have electro-deposited silver on the aluminum plate. When silver was electro-deposited on the plate, silver nanoparticles were made along the hexagonal margins.

  2. Flexible SERS Substrates: Challenges and Opportunities

    Science.gov (United States)

    2016-01-28

    are still widely used due to the ease with which silver and gold nanoparticles can be produced. Nanoparticle inks are colloidal suspensions of...interactions between the analyte, silver nanoparticles, and a salt. This system has also been applied to detection of trace antibiotics for food safety...Cleanable SERS Substrates Based on Silver Nanoparticle Decorated Electrospun Nano-fibrous Membranes Chaoyang Jiang Porous electrospun nanofibrous

  3. Criatividade em ação: ser criativo é ser criança

    Directory of Open Access Journals (Sweden)

    Antonio Mendes Silva Filho

    2012-11-01

    Full Text Available Todo ser humano é criativo e isso decorre da capacidade de imaginação. Essa capacidade é acentuada quando você tem a possibilidade de explorar e a curiosidade aguçada. Não exemplo melhor do que uma criança. Ser criativo é ser criança. Esta capacidade alcança o ápice quando se busca criar como criança fazendo uso de sagacidade, persistência, desorganização e com a possibilidade de errar. Isso é explorar e experimentar, deixando o cérebro livre e sem pressão, agindo despreocupadamente em determinado período de tempo. Nesse sentido, este artigo explora a importancia dar oportunidade do ser humano explorar sua capacidade de criar via imaginação

  4. Development of SERS active fibre sensors

    International Nuclear Information System (INIS)

    Polwart, Ewan

    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 (3-aminopropyl)trimethoxysilane-derivatised optical fibre. These sensors were used to obtain spectra with good signal to noise ratios from 4-(benzotriazol-5-ylazo)-3,5-dimethoxyphenylamine and crystal violet. Sensing of dyes in effluent was also investigated. The development of sensors for the measurement of pH, by treating the SERS-active fibre tip with pH sensitive dyes is also described. Spectral changes were observed with these sensors as a response to the pH. Partial least squares regression was used to produce linear calibration models for the pH range 5-11 from which it was possible to predict the pH with an accuracy of ∼0.2 pH units. Some of the limitations of these sensors were explored. The feasibility of using these sensors for measurement of oxygen and thiols, was investigated. The measurement of oxygen using methylene blue as a transducer was demonstrated. Two transduction methodologies--reactions with iron porphyrins and pyrrole-2,5-diones

  5. 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.

  6. El Segundo Cerebro del ser humano.

    OpenAIRE

    Rocío Ponce

    2015-01-01

    Existen dos tipos de cerebros, el conocido por todos formado por el sistema nervioso central, que sería el cerebro donde las emociones se forman en base a las experiencias anteriores. El segundo cerebro, el otro, ignorado por la mayoría de seres humanos es el cerebro que está en los intestinos, Sistema Nervioso Enteral o mesentérico, que se caracteriza por la relación del cerebro y aparato digestivo, este cerebro posee más neuronas que su par, guarda emociones, determina la respuesta de acuer...

  7. On the chemical enhancement in SERS

    Science.gov (United States)

    Jensen, Lasse

    2012-12-01

    In Surface-enhanced Raman scattering (SERS), the Raman signal of a molecule adsorbed on a metal surface is enhanced by many orders of magnitude. This provides a "finger-print" of molecules which can be used in ultrasensitive sensing devises. Here we present a time-dependent density functional theory (TDDFT) study of the molecule-surface chemical coupling in SERS. A systematic study of the chemical enhancement (CHEM) of meta-and para-substituted pyridines interacting with a small silver cluster (Ag20) is presented. We find that the magnitude of chemical enhancement is governed to a large extent by the energy difference between the highest occupied energy level (HOMO) of the metal and the lowest unoccupied energy level (LUMO) of the molecule. A two-state approximation shows that the enhancement scales roughly as (ωX/ω¯e)4, where accent="true">ω¯e is an average excitation energy between the HOMO of the metal and the LUMO of the molecule and wX the HOMO-LUMO gap of the free molecule. Furthermore, we demonstrate that it is possible to control the CHEM enhancement by switching a dithienylethene photoswitch from its closed form to its open form. The open form of the photoswitch is found to be the strongest Raman scatterer when adsorbed on the surface whereas the opposite is found for the free molecule. This trend is explained using the simple two-state approximation.

  8. Hiperentorno de enseñanza-aprendizaje sobre procedimientos técnicos de avanzada en la carrera de bioanálisis clínico

    Directory of Open Access Journals (Sweden)

    Haydée Cruz Vadell

    2015-07-01

    Full Text Available Teniendo en cuenta la insuficiente bibliografía disponible para los estudiantes de la carrera de bioanálisis clínico, sobre los procedimientos técnicos de avanzada, así como la escasa aplicación de los métodos con tecnología novedosa en los centros asistenciales, se diseñó un hiperentorno de enseñanza-aprendizaje, para que fuera utilizado como material de consulta, preparación y autoevaluación en esta asignatura. Para su confección como plataforma se empleó la herramienta CrheaSoft 2.2 y se estructuró en diferentes módulos: Inicio, Temario, Glosario, Ejercicios, Mediateca, Complemento, Créditos y Ayuda. La aplicación del módulo Ejercicio en un grupo de estudiantes de quinto año de la carrera demostró que el producto constituyó un importante material de apoyo a la docencia en esta especialidad

  9. 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

  10. SERS detection of biomolecules using lithographed nanoparticles towards a reproducible SERS biosensor

    Energy Technology Data Exchange (ETDEWEB)

    David, Catalina; Guillot, Nicolas; Chapelle, Marc Lamy de la [Laboratoire CSPBAT (FRE 3043), UFR SMBH, Universite Paris XIII, 74 rue Marcel Cachin, F-93017 Bobigny (France); Shen, Hong; Toury, Timothee, E-mail: marc.lamydelachapelle@univ-paris13.fr [ICD-LNIO-UMR, CNRS 6279, Universite de technologie de Troyes, 12 rue Marie Curie, F-10010 Troyes (France)

    2010-11-26

    In this paper we highlight the accurate spectral detection of bovine serum albumin and ribonuclease-A using a surface-enhanced Raman scattering (SERS) substrate based on gold nanocylinders obtained by electron-beam lithography (EBL). The nanocylinders have diameters from 100 to 180 nm with a gap of 200 nm. We demonstrate that optimizing the size and the shape of the lithographed gold nanocylinders, we can obtain SERS spectra of proteins at low concentration. This SERS study enabled us to estimate high enhancement factors (10{sup 5} for BSA and 10{sup 7} for RNase-A) of important bands in the protein Raman spectrum measured for 1 mM concentration. We demonstrate that, to reach the highest enhancement, it is necessary to optimize the SERS signal and that the main parameter of optimization is the LSPR position. The LSPR have to be suitably located between the laser excitation wavelength, which is 632.8 nm, and the position of the considered Raman band. Our study underlines the efficiency of gold nanocylinder arrays in the spectral detection of proteins.

  11. 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

  12. 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

  13. 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.

  14. La superación en el sector de la salud desde la teoría de la educación avanzada. Cuba. 2012-2014

    Directory of Open Access Journals (Sweden)

    Leticia Bustamante Alfonso

    2017-05-01

    Full Text Available Para los profesores que tienen como encargo la preparación de los cuadros y las reservas de la Salud Pública en Cuba, es imprescindible el mejoramiento profesional y humano en correspondencia con las exigencias del Sistema Nacional de Salud. En tal sentido, la autora se propuso como objetivo del presente trabajo investigativo diseñar una estrategia de superación para el mejoramiento profesional y humano de los profesores vinculados a la preparación de cuadros y reservas de la Salud Pública. Se realizó la caracterización del estado de la superación y del desempeño profesional pedagógico de estos profesores, se determinaron los problemas educativos, de investigación científica y de organización del trabajo que constituyeron la situación problémica en la superación. Mediante el proceso de parametrización empleado se determinó como variable el mejoramiento profesional y humano, se utilizaron métodos teóricos como el análisis documental, la sistematización entre otros y métodos empíricos como la encuesta, la entrevista y se consultó a los especialistas en el tema investigado. Se obtuvo una estrategia que ha propiciado el mejoramiento del desempeño profesional pedagógico de los referidos profesores. La estrategia diseñada sobre la base de las relaciones esenciales manifiestas entre las exigencias del Sistema Nacional de Salud y los postulados teóricos de la Pedagogía y de la Teoría de la Educación Avanzada, permitieron la factibilidad del mejoramiento profesional y humano de estos docentes.

  15. MODOS DE SER DA JUVENTUDE OCIDENTAL

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    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.

  16. Llegar a ser Simone de Beauvoir

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    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.

  17. Libertas que serás enfermagem

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    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.

  18. 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

  19. Instaurando maneiras de ser, conhecer e interpretar

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    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.

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

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    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

  1. SERS microscopy: plasmonic nanoparticle probes and biomedical applications

    Science.gov (United States)

    Gellner, M.; Schütz, M.; Salehi, M.; Packeisen, J.; Ströbel, P.; Marx, A.; Schmuck, C.; Schlücker, S.

    2010-08-01

    Nanoparticle probes for use in targeted detection schemes and readout by surface-enhanced Raman scattering (SERS) comprise a metal core, Raman reporter molecules and a protective shell. One design of SERS labels specifically optimized for biomedical applications in conjunction with red laser excitation is based on tunable gold/silver nanoshells, which are completely covered by a self-assembled monolayer (SAM) of Raman reporters. A shell around the SAM-coated metal core stabilizes the colloid and prevents particle aggregation. The optical properties and SERS efficiencies of these plasmonic nanostructures are characterized both experimentally and theoretically. Subsequent bioconjugation of SERS probes to ligands such as antibodies is a prerequisite for the selective detection of the corresponding target molecule via the characteristic Raman signature of the label. Biomedical imaging applications of SERS-labeled antibodies for tumor diagnostics by SERS microscopy are presented, using the localization of the tumor suppressor p63 in prostate tissue sections as an example.

  2. 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

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    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

  3. Label-free in situ SERS imaging of biofilms.

    Science.gov (United States)

    Ivleva, Natalia P; Wagner, Michael; Szkola, Agathe; Horn, Harald; Niessner, Reinhard; Haisch, Christoph

    2010-08-12

    Surface-enhanced Raman scattering (SERS) is a promising technique for the chemical characterization of biological systems. It yields highly informative spectra, can be applied directly in aqueous environment, and has high sensitivity in comparison with normal Raman spectroscopy. Moreover, SERS imaging can provide chemical information with spatial resolution in the micrometer range (chemical imaging). In this paper, we report for the first time on the application of SERS for in situ, label-free imaging of biofilms and demonstrate the suitability of this technique for the characterization of the complex biomatrix. Biofilms, being communities of microorganisms embedded in a matrix of extracellular polymeric substances (EPS), represent the predominant mode of microbial life. Knowledge of the chemical composition and the structure of the biofilm matrix is important in different fields, e.g., medicine, biology, and industrial processes. We used colloidal silver nanoparticles for the in situ SERS analysis. Good SERS measurement reproducibility, along with a significant enhancement of Raman signals by SERS (>10(4)) and highly informative SERS signature, enables rapid SERS imaging (1 s for a single spectrum) of the biofilm matrix. Altogether, this work illustrates the potential of SERS for biofilm analysis, including the detection of different constituents and the determination of their distribution in a biofilm even at low biomass concentration.

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

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    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

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

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    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.

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

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    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.

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

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    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

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

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    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.

  9. QUE É O "SER DA FAMÍLIA"?

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    Josefa Aida Delgado

    2005-01-01

    Full Text Available Es un estudio basado en la filosofía fenomenológica heideggeriana, su propósito es desvelar los elementos estructurales de la existencia del "ser de la familia". El camino metodológico fue construido con base en el pensamiento de Heidegger. Los datos de la familia fueron recolectados por medio de las entrevistas y las observaciones. Cada uno de nosotros contribuye para su existencia, y ella posibilita el desarrollo de nuestro "ser-en el-mundo" al vivenciar y compartir experiencias cotidianas de la familia. Allí surge la posibilidad de compartir un modo de ser en el mundo, un modo de cuidado para "ser familia en el mundo". Un mundo que genera esa unidad de relacionamiento que emerge de sentimientos interligados entre los integrantes, respondiendo a las exigencias de cada miembro, por el sentimiento de pertenencia primaria generado en ellos. Esa unidad da la posibilidad de nacer a cada uno de nosotros, asi también, nos da la posibilidad de poder ser ser humano, llegando a ser un referencial de sí misma en cada ser humano.

  10. IR, Raman and SERS studies of methyl salicylate

    Science.gov (United States)

    Varghese, Hema Tresa; Yohannan Panicker, C.; Philip, Daizy; Mannekutla, James R.; Inamdar, S. R.

    2007-04-01

    The IR and Raman spectra of methyl salicylate (MS) were recorded and analysed. Surface enhanced Raman scattering (SERS) spectrum was recorded in silver colloid. The vibrational wave numbers of the compound have been computed using the Hartree-Fock/6-31G * basis and compared with the experimental values. SERS studies suggest a flat orientation of the molecule at the metal surface.

  11. 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

  12. Development of optimized nanogap plasmonic substrate for improved SERS enhancement

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    Jayakumar Perumal

    2017-05-01

    Full Text Available SERS enhancement factor (EF of planar substrates depends on the size and shape of the fine nanostructure forming a defect free, well-arranged matrix. Nano-lithographic process is considered to be the most advanced methods employed for the fabrication SERS substrates. Nanostructured plasmonic substrates with nanogap (NG pattern often results in stable, efficient and reproducible SERS enhancement. For such substrates, NG and their diagonal length (DL need to be optimized. Theoretically smaller NGs (∼30-40 nm or smaller results in higher SERS enhancement. However, fabrication of NG substrates below such limit is a challenge even for the most advanced lithography process. In this context, herein, we report the optimization of fabrication process, where higher SERS enhancement can be realized from larger NGs substrates by optimizing their DL of nanostructures between the NGs. Based on simulation we could demonstrate that, by optimizing the DL, SERS enhancement from larger NG substrate such as 60 and 80 nm could be comparable to that of smaller (40nm NG substrates. We envision that this concept will open up new regime in the nanofabrication of practically feasible NG based plasmonic substrates with higher SERS enhancement. Initial results of our experiments are in close agreement with our simulated study.

  13. 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

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

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    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.

  15. 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.

  16. Historia de una coma. Gadamer y el sentido del ser

    OpenAIRE

    Vattimo, Gianni

    2005-01-01

    A partir de la doble posibilidad de traducir en las lenguas románicas la expresión gadameriana «Sein, das verstanden werden kann, ist Sprache» como «El ser, que puede ser comprendido, es lenguaje» o como «El ser que puede ser comprendido es lenguaje», se consideran las importantes repercusiones ontológicas que tendría una interpretación más moderada (y más habitual) de ese enunciado (la primera exhibida), o una lectura más radical y nihilista (la que aquí se defiende) del mismo (la ...

  17. Dynamic SERS nanosensor for neurotransmitter sensing near neurons.

    Science.gov (United States)

    Lussier, Félix; Brulé, Thibault; Bourque, Marie-Josée; Ducrot, Charles; Trudeau, Louis-Éric; Masson, Jean-François

    2017-12-04

    Current electrophysiology and electrochemistry techniques have provided unprecedented understanding of neuronal activity. However, these techniques are suited to a small, albeit important, panel of neurotransmitters such as glutamate, GABA and dopamine, and these constitute only a subset of the broader range of neurotransmitters involved in brain chemistry. Surface-enhanced Raman scattering (SERS) provides a unique opportunity to detect a broader range of neurotransmitters in close proximity to neurons. Dynamic SERS (D-SERS) nanosensors based on patch-clamp-like nanopipettes decorated with gold nanoraspberries can be located accurately under a microscope using techniques analogous to those used in current electrophysiology or electrochemistry experiments. In this manuscript, we demonstrate that D-SERS can measure in a single experiment ATP, glutamate (glu), acetylcholine (ACh), GABA and dopamine (DA), among other neurotransmitters, with the potential for detecting a greater number of neurotransmitters. The SERS spectra of these neurotransmitters were identified with a barcoding data processing method and time series of the neurotransmitter levels were constructed. The D-SERS nanosensor was then located near cultured mouse dopaminergic neurons. The detection of neurotransmitters was performed in response to a series of K + depolarisations, and allowed the detection of elevated levels of both ATP and dopamine. Control experiments were also performed near glial cells, showing only very low basal detection neurotransmitter events. This paper demonstrates the potential of D-SERS to detect neurotransmitter secretion events near living neurons, but also constitutes a strong proof-of-concept for the broad application of SERS to the detection of secretion events by neurons or other cell types in order to study normal or pathological cell functions.

  18. 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.

  19. Superhydrophobic Ag nanostructures on polyaniline membranes with strong SERS enhancement.

    Science.gov (United States)

    Liu, Weiyu; Miao, Peng; Xiong, Lu; Du, Yunchen; Han, Xijiang; Xu, Ping

    2014-11-07

    We demonstrate here a facile fabrication of n-dodecyl mercaptan-modified superhydrophobic Ag nanostructures on polyaniline membranes for molecular detection based on SERS technique, which combines the superhydrophobic condensation effect and the high enhancement factor. It is calculated that the as-fabricated superhydrophobic substrate can exhibit a 21-fold stronger molecular condensation, and thus further amplifies the SERS signal to achieve more sensitive detection. The detection limit of the target molecule, methylene blue (MB), on this superhydrophobic substrate can be 1 order of magnitude higher than that on the hydrophilic substrate. With high reproducibility, the feasibility of using this SERS-active superhydrophobic substrate for quantitative molecular detection is explored. A partial least squares (PLS) model was established for the quantification of MB by SERS, with correlation coefficient R(2) = 95.1% and root-mean-squared error of prediction (RMSEP) = 0.226. We believe this superhydrophobic SERS substrate can be widely used in trace analysis due to its facile fabrication, high signal reproducibility and promising SERS performance.

  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. Aplicación de tecnologías gráficas avanzadas como elemento de apoyo en los procesos de enseñanza-aprendizaje del dibujo, diseño y artes plásticas

    OpenAIRE

    DE LA TORRE CANTERO, JORGE LUIS

    2013-01-01

    Los procesos de enseñanza¿aprendizaje del ¿dibujo¿ están muy condicionados por las herramientas gráficas empleadas. En los últimos años, han surgido diversas tecnologías y nuevos contextos educativos (Espacio Europeo de Educación, educación on¿line, ..) que plantean grandes retos en el campo de la enseñanza del ¿dibujo¿. Al mencionar las Tecnologías Gráficas Avanzadas (TGAs) se hace referencia, a aquellas que pueden tener impacto en la enseñanza. En el contexto específ...

  2. 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.

  3. 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.

  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. 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

  6. Potential application of SERS for arsenic speciation in biological matrices.

    Science.gov (United States)

    Yang, Mingwei; Matulis, Shannon; Boise, Lawrence H; McGoron, Anthony J; Cai, Yong

    2017-08-01

    Speciation of arsenic is usually carried out using chromatography-based methods coupled with spectroscopic determination; however, the inevitable procedures involving sample preparation and separation could potentially alter the integrity of the arsenic metabolites present in biological samples. Surface-enhanced Raman spectroscopy (SERS) could be a promising alternative for providing a reliable arsenic analysis under the influence of a cellular matrix. A method for arsenic speciation using SERS in cellular matrix was developed in this study and four arsenicals were selected, including arsenite (As III ), arsenate (As V ), monomethylarsonic acid (MMA V ) and dimethylarsinic acid (DMA V ). Silver nanoparticles in the form of colliodal suspension with different surface charges, i.e., coated with citrate (AgNPs-Citrate) and spermine (AgNPs-Spermine) were employed as SERS substrates. Adsorption of arsenicals on nanoparticles in colloidal suspensions and the cellular matrix and the pH, size, and zeta potential of the colloidal suspensions were investigated for a better understanding of the SERS signal response of arsenicals in the colloidal suspensions or under the influence of cellular matrix. Arsenicals showed substantially different SERS responses in the two colloidal suspensions, mainly because of the distinct difference in the interaction between the arsenicals and the nanoparticles. Arsenic speciation in cell lysate could be successfully carried out in AgNPs-Spermine suspension, while AgNPs-Citrate could not yield significant SERS signals under the experimental conditions. This study proved that AgNPs-Spermine colloidal suspension could be a promising SERS substrate for studying arsenic metabolism in a biological matrix, reducing the bias caused by traditional techniques that involve sample extraction and pretreatment.

  7. 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.

  8. 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...

  9. 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

  10. Plasmonic crystal based solid substrate for biomedical application of SERS

    Science.gov (United States)

    Morasso, Carlo F.; Mehn, Dora; Picciolini, Silvia; Vanna, Renzo; Bedoni, Marzia; Gramatica, Furio; Pellacani, Paola; Frangolho, Ana; Marchesini, Gerardo; Valsesia, Andrea

    2014-02-01

    Surface Enhanced Raman Spectroscopy is a powerful analytical technique that combines the excellent chemical specificity of Raman spectroscopy with the good sensitivity provided by the enhancement of the signal observed when a molecule is located on (or very close to) the surface of suitable nanostructured metallic materials. The availability of cheap, reliable and easy to use SERS substrates would pave the road to the development of bioanalytical tests that can be used in clinical practice. SERS, in fact, is expected to provide not only higher sensitivity and specificity, but also the simultaneous and markedly improved detection of several targets at the same time with higher speed compared to the conventional analytical methods. Here, we present the SERS activity of 2-D plasmonic crystals made by polymeric pillars embedded in a gold matrix obtained through the combination of soft-lithography and plasma deposition techniques on a transparent substrates. The use of a transparent support material allowed us to perform SERS detection from support side opening the possibility to use these substrates in combination with microfluidic devices. In order to demonstrate the potentialities for bioanalytical applications, we used our SERS active gold surface to detect the oxidation product of apomorphine, a well-known drug molecule used in Parkinson's disease which has been demonstrated being difficult to study by traditional HPLC based approaches.

  11. Normal Raman and SERS spectroscopy of the vitamin E

    International Nuclear Information System (INIS)

    Cai Tiantian; Gu Huaimin; Yuan Xiaojuan; Liu Fangfang

    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 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. 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.

  13. 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.

  14. Enhancing SERS by Means of Supramolecular Charge Transfer

    Science.gov (United States)

    Wong, Eric; Flood, Amar; Morales, Alfredo

    2009-01-01

    In a proposed method of sensing small quantities of molecules of interest, surface enhanced Raman scattering (SERS) spectroscopy would be further enhanced by means of intermolecular or supramolecular charge transfer. There is a very large potential market for sensors based on this method for rapid detection of chemical and biological hazards. In SERS, the Raman signals (vibrational spectra) of target molecules become enhanced by factors of the order of 108 when those molecules are in the vicinities of nanostructured substrate surfaces that have been engineered to have plasmon resonances that enhance local electric fields. SERS, as reported in several prior NASA Tech Briefs articles and elsewhere, has remained a research tool and has not yet been developed into a practical technique for sensing of target molecules: this is because the short range (5 to 20 nm) of the field enhancement necessitates engineering of receptor molecules to attract target molecules to the nanostructured substrate surfaces and to enable reliable identification of the target molecules in the presence of interferants. Intermolecular charge-transfer complexes have been used in fluorescence-, photoluminescence-, and electrochemistry-based techniques for sensing target molecules, but, until now, have not been considered for use in SERS-based sensing. The basic idea of the proposed method is to engineer receptor molecules that would be attached to nanostructured SERS substrates and that would interact with the target molecules to form receptor-target supramolecular charge-transfer complexes wherein the charge transfer could be photoexcited.

  15. 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.

  16. Highly Sensitive Filter Paper Substrate for SERS Trace Explosives Detection

    Directory of Open Access Journals (Sweden)

    Pedro M. Fierro-Mercado

    2012-01-01

    Full Text Available We report on a novel and extremely low-cost surface-enhanced Raman spectroscopy (SERS substrate fabricated depositing gold nanoparticles on common lab filter paper using thermal inkjet technology. The paper-based substrate combines all advantages of other plasmonic structures fabricated by more elaborate techniques with the dynamic flexibility given by the inherent nature of the paper for an efficient sample collection, robustness, and stability. We describe the fabrication, characterization, and SERS activity of our substrate using 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, and 1,3,5-trinitrobenzene as analytes. The paper-based SERS substrates presented a high sensitivity and excellent reproducibility for analytes employed, demonstrating a direct application in forensic science and homeland security.

  17. SERS-based pesticide detection by using nanofinger sensors

    Science.gov (United States)

    Kim, Ansoon; Barcelo, Steven J.; Li, Zhiyong

    2015-01-01

    Simple, sensitive, and rapid detection of trace levels of extensively used and highly toxic pesticides are in urgent demand for public health. Surface-enhanced Raman scattering (SERS)-based sensor was designed to achieve ultrasensitive and simple pesticide sensing. We developed a portable sensor system composed of high performance and reliable gold nanofinger sensor strips and a custom-built portable Raman spectrometer. Compared to the general procedure and previously reported studies that are limited to laboratory settings, our analytical method is simple, sensitive, rapid, and cost-effective. Based on the SERS results, the chemical interaction of two pesticides, chlorpyrifos (CPF) and thiabendazole (TBZ), with gold nanofingers was studied to determine a fingerprint for each pesticide. The portable SERS-sensor system was successfully demonstrated to detect CPF and TBZ pesticides within 15 min with a detection limit of 35 ppt in drinking water and 7 ppb on apple skin, respectively.

  18. In Vitro and In Vivo SERS Biosensing for Disease Diagnosis

    Directory of Open Access Journals (Sweden)

    T. Joshua Moore

    2018-05-01

    Full Text Available For many disease states, positive outcomes are directly linked to early diagnosis, where therapeutic intervention would be most effective. Recently, trends in disease diagnosis have focused on the development of label-free sensing techniques that are sensitive to low analyte concentrations found in the physiological environment. Surface-enhanced Raman spectroscopy (SERS is a powerful vibrational spectroscopy that allows for label-free, highly sensitive, and selective detection of analytes through the amplification of localized electric fields on the surface of a plasmonic material when excited with monochromatic light. This results in enhancement of the Raman scattering signal, which allows for the detection of low concentration analytes, giving rise to the use of SERS as a diagnostic tool for disease. Here, we present a review of recent developments in the field of in vivo and in vitro SERS biosensing for a range of disease states including neurological disease, diabetes, cardiovascular disease, cancer, and viral disease.

  19. 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

  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. Fabrication of SERS Substrate by Multilayered Nanosphere Deposition Technique

    International Nuclear Information System (INIS)

    Fu, Chit Yaw; Dinish, U. S.; Praveen, Thoniyot; Koh, Zhen Yu; Kho, Khiang Wei; Malini, Olivo

    2010-01-01

    Metal film over nanosphere (MFON) has been employed as a reproducible and predictable SERS-active device in biosensing applications. In addition to its economic fabrication process, such substrate can be further processed to a prism-structure with increased SERS enhancement and wider Plasmon tunability. In this work, we investigate an alternative coating method to deposit a larger area of well-ordered PS beads with different sizes (oe = 100nm and 400 nm) onto a glass. The result suggests that the proposed well-coating technique can be suitably used to form closely-packed PS beads with diameter less than 100 nm for developing MFON substrates.

  2. LA GENÉTICA Y LA DIGNIDAD DEL SER HUMANO

    OpenAIRE

    Nicolás Jouve de Barreda

    2013-01-01

    Los elementos biológicos del hombre no son suficientes para afrontar las cuestiones bioéticas que se plantean en torno al concepto de persona, pero son necesarios para definir con precisión las propiedades de los seres humanos y los aspectos teológicos, filosóficos y jurídicos que son atribuibles a cada persona. El ser humano es un ser singular. En él que conviven dos dimensiones de distinta naturaleza, una material y otra espiritual, y precisamente esta es la principal de las diferencias en...

  3. SERS Raman Sensor Based on Diameter-Modulated Sapphire Fiber

    Energy Technology Data Exchange (ETDEWEB)

    Shimoji, Yutaka

    2010-08-09

    Surface enhanced Raman scattering (SERS) has been observed using a sapphire fiber coated with gold nano-islands for the first time. The effect was found to be much weaker than what was observed with a similar fiber coated with silver nanoparticles. Diameter-modulated sapphire fibers have been successfully fabricated on a laser heated pedestal growth system. Such fibers have been found to give a modest increase in the collection efficiency of induced emission. However, the slow response of the SERS effect makes it unsuitable for process control applications.

  4. 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

    A great enhancement in Raman scattering (SERS) from heme-containing submembrane biomolecules inside intact erythrocytes and functional mitochondria is demonstrated for the first time using silver–silica beads prepared using a new method involving aerosol pyrolysis with aqueous diamminesilver...... 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...

  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. 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

  8. 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

  9. Processing ser and estar to locate objects and events

    Science.gov (United States)

    Dussias, Paola E.; Contemori, Carla; Román, Patricia

    2016-01-01

    In Spanish locative constructions, a different form of the copula is selected in relation to the semantic properties of the grammatical subject: sentences that locate objects require estar while those that locate events require ser (both translated in English as ‘to be’). In an ERP study, we examined whether second language (L2) speakers of Spanish are sensitive to the selectional restrictions that the different types of subjects impose on the choice of the two copulas. Twenty-four native speakers of Spanish and two groups of L2 Spanish speakers (24 beginners and 18 advanced speakers) were recruited to investigate the processing of ‘object/event + estar/ser’ permutations. Participants provided grammaticality judgments on correct (object + estar; event + ser) and incorrect (object + ser; event + estar) sentences while their brain activity was recorded. In line with previous studies (Leone-Fernández, Molinaro, Carreiras, & Barber, 2012; Sera, Gathje, & Pintado, 1999), the results of the grammaticality judgment for the native speakers showed that participants correctly accepted object + estar and event + ser constructions. In addition, while ‘object + ser’ constructions were considered grossly ungrammatical, ‘event + estar’ combinations were perceived as unacceptable to a lesser degree. For these same participants, ERP recording time-locked to the onset of the critical word ‘en’ showed a larger P600 for the ser predicates when the subject was an object than when it was an event (*La silla es en la cocina vs. La fiesta es en la cocina). This P600 effect is consistent with syntactic repair of the defining predicate when it does not fit with the adequate semantic properties of the subject. For estar predicates (La silla está en la cocina vs. *La fiesta está en la cocina), the findings showed a central-frontal negativity between 500–700 ms. Grammaticality judgment data for the L2 speakers of Spanish showed that beginners were significantly less

  10. 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.

  11. 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 Røssel

    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...

  12. 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.

  13. 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)

  14. Patchy silica-coated silver nanowires as SERS substrates

    International Nuclear Information System (INIS)

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

    2013-01-01

    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.

  15. [TLC-FT-SERS study on ingredients of Isrhynchophylline].

    Science.gov (United States)

    Wang, Yuan; Wang, Song-ying; Zhao, Yi-xue; Ren, Gui-fen; Zi, Feng-lan

    2002-02-01

    A new method for analysing the ingredients of Isrhynchophylline in Uncaria Rhynchophylla Jacks by thin layer chromatography (TLC) and the surface-enhanced Raman spectroscopy (SERS) is reported in this paper. The results show that the characteristic spectra bands of Isrhynchophylline situated at the thin layer with the amount of sample about 2.5 micrograms were obtained. The difference between SERS and solid spectra was found. Great enhancement of the 1,615 cm-1 spectral band was abstained. Molecule was absorbed in surface silver sol by pi electrons in phenyl and by pair of electrons in N together. An absorption model of Isrhynchophylline and silver sol was proposed. This method can be used to analyse the chemical ingredients with high sensitivity.

  16. [TLC-SERS study on evodiamine in evodia rutaecarpa].

    Science.gov (United States)

    Zhang, Jin-zhi; Wang, Yuan; Chen, Hui; Shao, Hui-bo

    2007-05-01

    A new method for analyzing the ingredients of evodiamine (EV), rutaecarpine (RU), hydroxyevodiamine (HYD), evodiamide (ED), dihydrorutaecarpine (DRU) and 14-formyldihydrorutaecarpine (FDRU) in evodia rutaecarpa using high performance thin layer chromatography (TLC) and surface enhanced Raman spectroscopy (SERS) technique is reported. The character of this method is that standard samples are not needed. The results show that the characteristic spectral bands of EV, RU, HYD, and ED can be obtained from the TLC spot with microgramme of sample. The spectral band at 1562 cm(-1) was obtained with great enhancement. Molecule absorbed in surface silver sol by nr electrons in ring. The spectral bands of EV, RU, HYD and ED are obviously different due to their differences in structure. The TLC and SERS techniques standard samples are a convenient and speedy method to analyze chemical ingredients with high sensitivity for the study of the Chinese traditional medicine.

  17. 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

  18. 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.

  19. 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.

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

    Science.gov (United States)

    2017-06-22

    which form covalent metal–S bonds), amine, cyanide , and carboxylic acid functional groups; and their adsorption depends on solution pH and ionic...for some SERS sensing appli- cations, such as biosensing in complex biological fluids (where multiple molecules with primary amine and carboxylic acid...bonding interactions.33d,e Furthermore, mixed SAMs can take advantage of multiple types of interactions and build complexity into the surface chemistry

  1. Significado de ser docente para el adulto mayor sanfernandino

    OpenAIRE

    Martina, Martha; Santos, Gladys; Lema, Julia

    2013-01-01

    Objetivos: Comprender el significado de ser docente para el adulto mayor de la Facultad de Medicina de San Marcos y describir las motivaciones que determinan, de alguna forma, su decisión de postergar su retiro, no obstante haber cumplido con los requisitos legales para la jubilación. Diseño: Estudio de caso cualitativo. Institución: Facultad de Medicina, UNMSM. Participantes: Docentes adulto mayores de la Facultad de Medicina. Intervenciones: Entrevista a profundidad. Principales medidas de ...

  2. Laser in medicine Láser en medicina

    Directory of Open Access Journals (Sweden)

    Juan C. Cárdenas

    1993-03-01

    Full Text Available The fundamentals of laser functioning and a brief historic description on the subject are presented; laser Is classified according to emission potency, materials with which it is built and pulsation. Different mechanisms of action of laser as well as Its indications and contraindications are discussed. Emphasis is given to low-power laser. Local and foreign experiences with Its medlcal use are briefly described

    Se revisan los principios fundamentales del funcionamiento del láser, se hace una breve revisión histórica del mismo y se lo clasifica de acuerdo con la potencia de emisión, los materiales de fabricación y la pulsación. Se enumeran los diferentes mecanismos de acción del láser y sus indicaciones y contraindicaciones haciendo énfasis en lo concerniente al láser de baja potencia, tanto pulsado como no pulsado; se alude a las experiencias nacionales y de otros países.

  3. Interpenetrating polyaniline-gold electrodes for SERS and electrochemical measurements

    Science.gov (United States)

    West, R. M.; Semancik, S.

    2016-11-01

    Facile fabrication of nanostructured electrode arrays is critical for development of bimodal SERS and electrochemical biosensors. In this paper, the variation of applied potential at a polyaniline-coated Pt electrode is used to selectivity deposit Au on the polyaniline amine sites or on the underlying Pt electrode. By alternating the applied potential, the Au is grown simultaneously from the top and the bottom of the polyaniline film, leading to an interpenetrated, nanostructured polymer-metal composite extending from the Pt electrode to the electrolyte solution. The resulting films have unique pH-dependent electrochemical properties, e.g. they retain electrochemical activity in both acidic and neutral solutions, and they also include SERS-active nanostructures. By varying the concentration of chloroaurate used during deposition, Au nanoparticles, nanodendrites, or nanosheets can be selectively grown. For the films deposited under optimal conditions, using 5 mmol/L chloroaurate, the SERS enhancement factor for Rhodamine 6G was found to be as high as 1.1 × 106 with spot-to-spot and electrode-to-electrode relative standard deviations as low as 8% and 12%, respectively. The advantages of the reported PANI-Au composite electrodes lie in their facile fabrication, enabling the targeted deposition of tunable nanostructures on sensing arrays, and their ability to produce orthogonal optical and electrochemical analytical results.

  4. 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.

  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. 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.

  7. Reduced graphene oxide wrapped Ag nanostructures for enhanced SERS activity

    Science.gov (United States)

    Nair, Anju K.; Kala, M. S.; Thomas, Sabu; Kalarikkal, Nandakumar

    2018-04-01

    Graphene - metal nanoparticle hybrids have received great attention due to their unique electronic properties, large specific surface area, very high conductivity and more charge transfer. Thus, it is extremely advantages to develop a simple and efficient process to disperse metal nanostructures over the surface of graphene sheets. Herein, we report a hydrothermal assisted strategy for developing reduced graphene oxide /Ag nanomorphotypes (cube, wire) for surface enhanced Raman scattering (SERS) applications, considering the advantages of synergistic effect of graphene and plasmonic properties of Ag nanomorphotypes.

  8. Silver coated aluminium microrods as highly colloidal stable SERS platforms.

    Science.gov (United States)

    Pazos-Perez, Nicolas; Borke, Tina; Andreeva, Daria V; Alvarez-Puebla, Ramon A

    2011-08-01

    We report on the fabrication of a novel material with the ability to remain in solution even under the very demanding conditions required for structural and dynamic characterization of biomacromolecule assays. This stability is provided by the increase in surface area of a low density material (aluminium) natively coated with a very hydrophilic surface composed of aluminium oxide (Al(2)O(3)) and metallic silver nanoparticles. Additionally, due to the dense collection of active hot spots on their surface, this material offers higher levels of SERS intensity as compared with the same free and aggregated silver nanoparticles. This journal is © The Royal Society of Chemistry 2011

  9. Hierarchical Ag mesostructures for single particle SERS substrate

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Minwei, E-mail: xuminwei@xjtu.edu.cn; Zhang, Yin

    2017-01-30

    Highlights: • Hierarchical Ag mesostructures with the size of 250, 360 and 500 nm are synthesized via a seed-mediated approach. • The Ag mesostructures present the tailorable size and highly roughened surfaces. • The average enhancement factors for individual Ag mesostructures were estimated to be as high as 10{sup 6}. - Abstract: Hierarchical Ag mesostructures with highly rough surface morphology have been synthesized at room temperature through a simple seed-mediated approach. Electron microscopy characterizations indicate that the obtained Ag mesostructures exhibit a textured surface morphology with the flower-like architecture. Moreover, the particle size can be tailored easily in the range of 250–500 nm. For the growth process of the hierarchical Ag mesostructures, it is believed that the self-assembly mechanism is more reasonable rather than the epitaxial overgrowth of Ag seed. The oriented attachment of nanoparticles is revealed during the formation of Ag mesostructures. Single particle surface enhanced Raman spectra (sp-SERS) of crystal violet adsorbed on the hierarchical Ag mesostructures were measured. Results reveal that the hierarchical Ag mesostructures can be highly sensitive sp-SERS substrates with good reproducibility. The average enhancement factors for individual Ag mesostructures are estimated to be about 10{sup 6}.

  10. Superhydrophobic analyte concentration utilizing colloid-pillar array SERS substrates.

    Science.gov (United States)

    Wallace, Ryan A; Charlton, Jennifer J; Kirchner, Teresa B; Lavrik, Nickolay V; Datskos, Panos G; Sepaniak, Michael J

    2014-12-02

    The ability to detect a few molecules present in a large sample is of great interest for the detection of trace components in both medicinal and environmental samples. Surface enhanced Raman spectroscopy (SERS) is a technique that can be utilized to detect molecules at very low absolute numbers. However, detection at trace concentration levels in real samples requires properly designed delivery and detection systems. The following work involves superhydrophobic surfaces that have as a framework deterministic or stochastic silicon pillar arrays formed by lithographic or metal dewetting protocols, respectively. In order to generate the necessary plasmonic substrate for SERS detection, simple and flow stable Ag colloid was added to the functionalized pillar array system via soaking. Native pillars and pillars with hydrophobic modification are used. The pillars provide a means to concentrate analyte via superhydrophobic droplet evaporation effects. A ≥ 100-fold concentration of analyte was estimated, with a limit of detection of 2.9 × 10(-12) M for mitoxantrone dihydrochloride. Additionally, analytes were delivered to the surface via a multiplex approach in order to demonstrate an ability to control droplet size and placement for scaled-up uses in real world applications. Finally, a concentration process involving transport and sequestration based on surface treatment selective wicking is demonstrated.

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

    African Journals Online (AJOL)

    Pramod Kumar

    Objective: We aimed at studying the relationship between apoA4 gene polymorphisms (Thr347Ser and ... showed significant association with lipid risk factors like high levels of ..... in German population showed that Ser347 allele is associated.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Synthesis of SERS active Au nanowires in different noncoordinating solvents

    Energy Technology Data Exchange (ETDEWEB)

    Hou Xiaomiao; Zhang Xiaoling, E-mail: zhangxl@bit.edu.cn [Key Laboratory of Cluster Science of Ministry of Education, Beijing Institute of Technology, Department of Chemistry, School of Science (China); Fang Yan, E-mail: fangyan@mail.cnu.edu.cn [Beijing Key Laboratory for Nano-Photonics and Nano-Structure (NPNS), Capital Normal University (China); Chen Shutang; Li Na; Zhou Qi [Key Laboratory of Cluster Science of Ministry of Education, Beijing Institute of Technology, Department of Chemistry, School of Science (China)

    2011-06-15

    Au nanowires with length up to micrometers were synthesized through a simple and one-pot solution growth method. HAuCl{sub 4} was reduced in a micellar structure formed by 1-octadecylamine and oleic acid in hexane, heptane, toluene and chloroform, respectively. As the non-polarity of noncoordinating solvents can affect the nucleation and growth rates of Au nanostructures, Au nanowires with different diameters could be obtained by changing the noncoordinating solvents in the synthetic process. The influences of the solvents on the morphology of Au nanowires were systematically studied. When using hexane as reaction solvent, the product turned to be high portion of Au nanowires with more uniform size than the others. Furthermore, surface-enhanced Raman scattering (SERS) spectrum of 2-thionaphthol was obtained on the Au nanowire-modified substrate, indicating that the as-synthesized Au nanowires have potential for highly sensitive optical detection application.

  17. La persona: razón de ser del derecho

    Directory of Open Access Journals (Sweden)

    Jaime Baquero de la Calle

    2008-01-01

    Full Text Available Todo ordenamiento jurídico se propone alcanzar el bien común. Dentro de este marco institucional, la justicia es el valor supremo que procura garantizar la autoridad competente. ¿Cuándo es posible decir que se está actuando según la justicia? Encontrar una respuesta requiere remontarse a los principios fundamentales que han dado origen a toda formulación jurídica. Y detrás de tales principios se encuentra la persona, destinatario final del ordenamiento. La norma escrita no se funda –por lo menos, no debería ser así– en el azar o las ideas políticas del gobierno de turno. Ante la inminente presencia de una Asamblea Constituyente, es imperativo volver sobre los fundamentos últimos de todo Estado de Derecho.

  18. Laser ablation studies of Deposited Silver Colloids Active in SERS

    International Nuclear Information System (INIS)

    La Porte, R.T.; Moreno, D.S.; Striano, M.C.; Munnoz, M.M.; Garcia-Ramos, J.V.; Cortes, S.S.; Koudoumas, E.

    2002-01-01

    Laser ablation of deposited silver colloids, active in SERS, is carried out at three different laser wavelengths (KrF, XeCl and Nd:YAG at λ = 248, 308 and 532 nm respectively). Emission form excited neutral Ag and Na atoms, present in the ablation plume, is detected with spectral and temporal resolution. The expansion velocity of Ag in the plume is estimated in ∼1x104m s-1, Low-fluence laser ablation of the colloids yields ionized species that are analyzed by time-of-flight mass spectroscopy. Na+ and Agn+(n≤3) are observed. Composition of the mass spectra and widths of the mass peaks are found to be dependent on laser wavelength, suggesting that the dominant ablation mechanisms are different at the different wavelenghts.

  19. 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.

  20. La razón de ser de los conglomerantes

    Directory of Open Access Journals (Sweden)

    Fernández Paris, J. M.

    1978-09-01

    Full Text Available La palabra cemento sirve para designar cualquier sustancia con capacidad adherente, mientras que el término conglomerante se aplica a la acción de aglutinar en un todo partículas que anteriormente estaban sueltas o independientes. Según su capacidad o no de endurecer bajo agua, los conglomerantes se clasifican en hidráulicos y no hidráulicos. Se denominan hidráulicos a aquéllos que tienen la citada facultad. Entre todos los conglomerantes hidráulicos, han adquirido en la construcción una carta de naturaleza inusitada durante los últimos tiempos los denominados cementos porland. Quiero hacer constar que trato de exponer simplemente aquellos conceptos químicos que, a mi modo de ver y de acuerdo con mi experiencia, constituyen la razón de ser que nos permita apreciar sus cualidades y propiedades.

  1. 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.

  2. Recubrimiento por láser de aleaciones cuasicristalinas

    Directory of Open Access Journals (Sweden)

    Audebert, F.

    1998-04-01

    Full Text Available Quasicrystals are a new class of ordenated structures with metaestable characteristics at room temperature. Quasicrystalline phases can be obtained by rapid quenching from the melt of some alloys. In general, quasicrystals present properties which make these alloys promising for wear and corrosion resistant coatings applications. During the last years, the development of quasicrystalline coatings by means of thermal spray techniques has been impulsed. However, no references have been found of their application by means of laser techniques. In this work four claddings of quasicrystalline compositions formed over aluminum substrate, produced by a continuos CO2 laser using simultaneous powders mixture injection are presented. The claddings were characterized by X ray diffraction, scanning electron microscopy and Vickers microhardness.

    Los cuasicristales constituyen un nuevo tipo de estructuras ordenadas con características metaestables a temperatura ambiente. En general, en determinadas aleaciones, pueden obtenerse por enfriamiento rápido desde el estado líquido. Han demostrado poseer buenas propiedades para su aplicación como recubrimientos resistentes al desgaste y a la corrosión. En este sentido, desde hace unos años, se ha impulsado el desarrollo de su aplicación mediante técnicas de thermal spray, aunque no se han encontrado referencias de su aplicación mediante técnicas de láser. En este trabajo, se presenta la formación de cuatro recubrimientos de aleaciones con composiciones cuasicristalinas sobre un sustrato de aluminio, utilizando un láser continuo de CO2, con inyección simultánea del material en forma de mezcla de polvos. Los mismos fueron caracterizados por difracción de rayos X, microscopía electrónica de barrido y microdureza Vickers.

  3. Study of pyruvate decarboxylase and thiamine kinase from brewer's yeast by SERS

    Science.gov (United States)

    Maskevich, Sergei A.; Chernikevich, Ivan P.; Gachko, Gennedy A.; Kivach, Leonid N.; Strekal, Nataliya D.

    1993-06-01

    The Surface Enhanced Raman Scattering (SERS) spectra of holopyruvate decarboxylase (PDC) and thiamine kinase (ThK) adsorbed on silver electrode were obtained. In contrast to the Raman, the SERS spectrum of PDC contained no modes of tryptophan residues, it indicates a removal of this moiety from the surface. In the SERS spectrum of ThK the bands belonging to ligands bound to the protein were observed. A correlation between the SERS signal intensity and the enzymatic activity of the ThK separate fraction and found. The influence of amino acids on SERS spectra of thiamine (Th) was studied to determine the possible composition on microsurrounding of coenzyme.

  4. SERS substrates fabricated using ceramic filters for the detection of bacteria

    Science.gov (United States)

    Mosier-Boss, P. A.; Sorensen, K. C.; George, R. D.; Obraztsova, A.

    2016-01-01

    SERS substrates were fabricated by filtering either Ag or Au colloidal particles onto rigid, ceramic filters - onto which suspensions of bacteria were then filtered. SERS spectra of the bacteria were obtained using a Raman spectrometer that has an 'orbital raster scan' capability. It was shown that bacteria samples prepared in this manner were uniformly distributed onto the surface of the SERS substrate. The effect of common buffer systems on the SERS spectra was investigated and the utility of using the SERS technique for speciation of bacteria was explored.

  5. "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

  6. ¿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

  7. 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.

  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. 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.

  10. SERS as a tool for in vitro toxicology.

    Science.gov (United States)

    Fisher, Kate M; McLeish, Jennifer A; Jamieson, Lauren E; Jiang, Jing; Hopgood, James R; McLaughlin, Stephen; Donaldson, Ken; Campbell, Colin J

    2016-06-23

    Measuring markers of stress such as pH and redox potential are important when studying toxicology in in vitro models because they are markers of oxidative stress, apoptosis and viability. While surface enhanced Raman spectroscopy is ideally suited to the measurement of redox potential and pH in live cells, the time-intensive nature and perceived difficulty in signal analysis and interpretation can be a barrier to its broad uptake by the biological community. In this paper we detail the development of signal processing and analysis algorithms that allow SERS spectra to be automatically processed so that the output of the processing is a pH or redox potential value. By automating signal processing we were able to carry out a comparative evaluation of the toxicology of silver and zinc oxide nanoparticles and correlate our findings with qPCR analysis. The combination of these two analytical techniques sheds light on the differences in toxicology between these two materials from the perspective of oxidative stress.

  11. [Eugenics and Falange through the journal Ser (1942-1957)].

    Science.gov (United States)

    Rendon, Sara Navarro

    2016-01-01

    Biopolitics has played an important role in fascist totalitarianism and the-Francoist regime was no exception. From the and with ultimate goal or regulating the population, measures were implemented to increase, care for and indoctrinate the population. This present study analyses the selection and promotion measures of some populations and the marginalisation of others proposed the Spanish Falangist Movement's official publication in the field of medicine, the journal Ser, Revista Medico-Social by the National Delegation of Health of the Traditionalist Spanish Phalanx of the Committees of the National Syndicalist Offensivie (F.E.T y de las J. O. N. S. 1942-1957). In this respect, the analysis of eugenic ideas and practice defended therein become especially interesting, claiming that, through indoctrination and health development, the race would be improved both physically and mentally. From the systematic analysis of the journals's contenets it has been demonstrated that this was one of the instruments used by the dictatorial regime to reconfigure eugenics in accordance with Catholic morals and national syndicalist politics.

  12. 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

  13. Fasting mediated increase in p-BAD(ser155) and p-AKT(ser473) in the prefrontal cortex of mice.

    Science.gov (United States)

    Pitchaimani, Vigneshwaran; Arumugam, Somasundaram; Thandavarayan, Rajarajan Amirthalingam; Karuppagounder, Vengadeshprabhu; Sreedhar, Remya; Afrin, Rejina; Harima, Meilei; Suzuki, Hiroshi; Miyashita, Shizuka; Nomoto, Mayumi; Sone, Hirohito; Suzuki, Kenji; Watanabe, Kenichi

    2014-09-05

    BAD-deficient mice and fasting have several common functional roles in seizures, beta-hydroxybutyrate (BHB) uptake in brain and alteration in counterregulatory hormonal regulation during hypoglycemia. Neuronal specific insulin receptor knockout (NIRKO) mice display impaired counterregulatory hormonal responses during hypoglycemia. In this study we investigated the fasting mediated expression of p-BAD(ser155) and p-AKT(ser473) in different regions of brain (prefrontal cortex, hippocampus, midbrain and hypothalamus). Fasting specifically increases p-BAD(ser155) and p-AKT(ser473) in prefrontal cortex and decreases in other regions of brain. Our results suggest that fasting may increase the uptake BHB by decreasing p-BAD(ser155) in the brain during hypoglycemia except prefrontal cortex and it uncovers specific functional area of p-BAD(ser155) and p-AKT(ser473) that may regulates counter regulatory hormonal response. Overall in support with previous findings, fasting mediated hypoglycemia activates prefrontal cortex insulin signaling which influences the hypothalamic paraventricular nucleus mediated activation of sympathoadrenal hormonal responses. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  14. 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

  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. The IkappaB kinase family phosphorylates the Parkinson's disease kinase LRRK2 at Ser935 and Ser910 during Toll-like receptor signaling.

    Directory of Open Access Journals (Sweden)

    Nicolas Dzamko

    Full Text Available Mutations in leucine-rich repeat kinase 2 (LRRK2 are strongly associated with late-onset autosomal dominant Parkinson's disease. LRRK2 is highly expressed in immune cells and recent work points towards a link between LRRK2 and innate immunity. Here we demonstrate that stimulation of the Toll-Like Receptor (TLR pathway by MyD88-dependent agonists in bone marrow-derived macrophages (BMDMs or RAW264.7 macrophages induces marked phosphorylation of LRRK2 at Ser910 and Ser935, the phosphorylation sites that regulate the binding of 14-3-3 to LRRK2. Phosphorylation of these residues is prevented by knock-out of MyD88 in BMDMs, but not the alternative TLR adaptor protein TRIF. Utilising both pharmacological inhibitors, including a new TAK1 inhibitor, NG25, and genetic models, we provide evidence that both the canonical (IKKα and IKKβ and IKK-related (IKKε and TBK1 kinases mediate TLR agonist induced phosphorylation of LRRK2 in vivo. Moreover, all four IKK members directly phosphorylate LRRK2 at Ser910 and Ser935 in vitro. Consistent with previous work describing Ser910 and Ser935 as pharmacodynamic biomarkers of LRRK2 activity, we find that the TLR independent basal phosphorylation of LRRK2 at Ser910 and Ser935 is abolished following treatment of macrophages with LRRK2 kinase inhibitors. However, the increased phosphorylation of Ser910 and Ser935 induced by activation of the MyD88 pathway is insensitive to LRRK2 kinase inhibitors. Finally, employing LRRK2-deficient BMDMs, we present data indicating that LRRK2 does not play a major role in regulating the secretion of inflammatory cytokines induced by activation of the MyD88 pathway. Our findings provide the first direct link between LRRK2 and the IKKs that mediate many immune responses. Further work is required to uncover the physiological roles that phosphorylation of LRRK2 by IKKs play in controlling macrophage biology and to determine how phosphorylation of LRRK2 by IKKs impacts upon the use of Ser

  17. 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.

  18. 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.

  19. Surface-enhanced Raman spectroscopy (SERS) using Ag nanoparticle films produced by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Smyth, C.A., E-mail: smythc2@tcd.ie [School of Physics, Trinity College Dublin, Dublin 2 (Ireland); Mirza, I.; Lunney, J.G.; McCabe, E.M. [School of Physics, Trinity College Dublin, Dublin 2 (Ireland)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer Pulsed laser deposition (PLD) produces silver nanoparticle films. Black-Right-Pointing-Pointer These films can be used for surface-enhanced Raman spectroscopy (SERS). Black-Right-Pointing-Pointer Commercial film shows good SERS reproducibility but poor signal intensity. Black-Right-Pointing-Pointer PLD shows a good SERS response coupled with good reproducibility. - Abstract: Thin silver nanoparticle films, of thickness 7 nm, were deposited onto glass microslides using pulsed laser deposition (PLD). The films were then characterised using UV-vis spectroscopy and scanning transmission electron microscopy before Rhodamine 6G was deposited onto them for investigation using surface-enhanced Raman spectroscopy (SERS). The sensitivity obtained using SERS was compared to that obtained using a colloidal silver suspension and also to a commercial SERS substrate. The reproducibility of the films is also examined using statistical analysis.

  20. 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

  1. Self-assembly Ag nanoparticle monolayer film as SERS Substrate for pesticide detection

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Li, E-mail: zhlisuzh@163.com [School of Chemistry and Life Science, Anhui Key Laboratory of Spin Electron and Nanomaterials (Cultivating Base), Suzhou University, SuZhou 234000 (China)

    2013-04-01

    A self-assembled protocol is introduced to provide effective platforms for the fabrication of ordered Ag nanosized monolayer film. The assembled Ag nanosized monolayer film was characterized using scanning electronic microscopy and surface-enhanced Raman scattering (SERS). The results show that the assembled SERS substrate own excellent Raman enhancement and reproducibility. The synthesized SERS-active substrate was further used to detect methyl-parathion, and the limitation of detection can reach 10{sup −7} M.

  2. El ser humano y sus posibilidades de construcción desde el cuidado

    Directory of Open Access Journals (Sweden)

    Alacoque Lorenzini Erdmann

    2003-01-01

    Full Text Available El artículo presenta algunas concepciones del ser humano en relación con el cuidado de enfermería. A partir de la organización de la vida se establecen relaciones, interacciones del ser humano, sus límites y posibilidades para el cuidado con la vida, con lo cotidiano y con la naturaleza. Resalta la importancia y el compromiso en la construcción colectiva del ser ciudadano.

  3. Realidad virtual y realidad aumentada : Interfaces avanzadas

    OpenAIRE

    Abásolo Guerrero, María José; Manresa Yee, Cristina; Más Sansó, Ramón; Vénere, Marcelo

    2011-01-01

    El presente libro es el resultado de la docencia e investigación en las áreas de Realidad Virtual, Realidad Aumentada e Interfaces basadas en visión, llevadas a cabo en tres instituciones universitarias, dos de ellas de Argentina –Universidad Nacional de La Plata (UNLP) y Universidad Nacional del Centro de la Provincia de Buenos Aires (UNICEN)– y una española –Universidad de las Islas Baleares (UIB)–. El texto se estructura en dos partes principales: la primera parte relacionada con Realid...

  4. Improving SERS uniformity by isolating hot spots in gold rod-in-shell nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shanshan; Liu, Zhonghui [Shanghai Jiao Tong University, School of Biomedical Engineering & Med-X Research Institute (China); Bartic, Carmen [KU Leuven, Department of Physics (Belgium); Xu, Hong, E-mail: xuhong@sjtu.edu.cn; Ye, Jian, E-mail: yejian78@sjtu.edu.cn [Shanghai Jiao Tong University, School of Biomedical Engineering & Med-X Research Institute (China)

    2016-08-15

    Surface-enhanced Raman scattering (SERS) tags show ultrasensitivity and multiplexing abilities due to strong and characteristic Raman signals and therefore can be utilized as optical labeling agents similar to fluorescent dyes and quantum dots for biosensing and bioimaging. However, SERS tags have the difficulty to realize quantitative analysis due to the uniformity and reproducibility issue. In this work, we have reported on a new type of SERS tag called Au rod-in-shell (RIS) gap-enhanced Raman tag (GERT). With the high-resolution transmission electron microscopy (TEM) and optical absorbance measurements, we have demonstrated the subnanometer sized gap junctions inside the RIS GERTs. SERS measurements and FDTD calculations show that the core–shell subnanometer gap geometry in the RIS GERTs not only generates strong SERS hot spots but also isolates SERS hot spots by Au shells to avoid the influence when the particle aggregates form, therefore showing better SERS uniformity and stronger SERS intensity than normal Au nanorods. Those RIS NPs exhibit great potential as the labeling agents for SERS-based bioimaging and biosensing applications.

  5. 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.

  6. Improving SERS uniformity by isolating hot spots in gold rod-in-shell nanoparticles

    International Nuclear Information System (INIS)

    Wang, Shanshan; Liu, Zhonghui; Bartic, Carmen; Xu, Hong; Ye, Jian

    2016-01-01

    Surface-enhanced Raman scattering (SERS) tags show ultrasensitivity and multiplexing abilities due to strong and characteristic Raman signals and therefore can be utilized as optical labeling agents similar to fluorescent dyes and quantum dots for biosensing and bioimaging. However, SERS tags have the difficulty to realize quantitative analysis due to the uniformity and reproducibility issue. In this work, we have reported on a new type of SERS tag called Au rod-in-shell (RIS) gap-enhanced Raman tag (GERT). With the high-resolution transmission electron microscopy (TEM) and optical absorbance measurements, we have demonstrated the subnanometer sized gap junctions inside the RIS GERTs. SERS measurements and FDTD calculations show that the core–shell subnanometer gap geometry in the RIS GERTs not only generates strong SERS hot spots but also isolates SERS hot spots by Au shells to avoid the influence when the particle aggregates form, therefore showing better SERS uniformity and stronger SERS intensity than normal Au nanorods. Those RIS NPs exhibit great potential as the labeling agents for SERS-based bioimaging and biosensing applications.

  7. 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

  8. 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.

  9. 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

  10. 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

  11. A Ag synchronously deposited and doped TiO2 hybrid as an ultrasensitive SERS substrate: a multifunctional platform for SERS detection and photocatalytic degradation.

    Science.gov (United States)

    Yang, Libin; Sang, Qinqin; Du, Juan; Yang, Ming; Li, Xiuling; Shen, Yu; Han, Xiaoxia; Jiang, Xin; Zhao, Bing

    2018-06-06

    Ag simultaneously deposited and doped TiO2 (Ag-TiO2) hybrid nanoparticles (NPs) were prepared via a sol-hydrothermal method, as both a sensitive surface-enhanced Raman scattering (SERS) substrate and a superior photocatalyst for the first time. Ag-TiO2 hybrid NPs exhibit excellent SERS performance for several probe molecules and the enhancement factor is calculated to be 1.86 × 105. The detection limit of the 4-mercaptobenzoic acid (4-MBA) probe on the Ag-TiO2 substrate is 1 × 10-9 mol L-1, which is four orders of magnitude lower than that on pure TiO2 as a consequence of the synergistic effects of TiO2 and Ag. This is the highest SERS sensitivity among the reported semiconductor substrates and even comparable to noble metal substrates, and a SERS enhancement mechanism from the synergistic contribution of the semiconductor and noble metal was proposed. And importantly, the Ag-TiO2 hybrid shows excellent photocatalytic degradation activity for the detected species under UV light irradiation at lower concentration conditions, even for the hard to degrade 4-MBA molecule. This makes the Ag-TiO2 hybrid promising as a dual-function platform for both highly sensitive SERS detection and photocatalytic degradation of a pollutant system. Moreover, it also proves that the Ag-TiO2 hybrid can serve as a promising recyclable SERS-active substrate by virtue of its photocatalytic self-cleaning properties for some specific applications, for instance comparative studies of different species on the same SERS platform, in addition to the economic benefit.

  12. In cellulo phosphorylation of XRCC4 Ser320 by DNA-PK induced by DNA damage

    International Nuclear Information System (INIS)

    Sharma, Mukesh Kumar; Imamichi, Shoji; Fukuchi, Mikoto; Samarth, Ravindra Mahadeo; Tomita, Masanori; Matsumoto, Yoshihisa

    2016-01-01

    XRCC4 is a protein associated with DNA Ligase IV, which is thought to join two DNA ends at the final step of DNA double-strand break repair through non-homologous end joining. In response to treatment with ionizing radiation or DNA damaging agents, XRCC4 undergoes DNA-PK-dependent phosphorylation. Furthermore, Ser260 and Ser320 (or Ser318 in alternatively spliced form) of XRCC4 were identified as the major phosphorylation sites by purified DNA-PK in vitro through mass spectrometry. However, it has not been clear whether these sites are phosphorylated in vivo in response to DNA damage. In the present study, we generated an antibody that reacts with XRCC4 phosphorylated at Ser320 and examined in cellulo phosphorylation status of XRCC4 Ser320. The phosphorylation of XRCC4 Ser320 was induced by γ-ray irradiation and treatment with Zeocin. The phosphorylation of XRCC4 Ser320 was detected even after 1 Gy irradiation and increased in a manner dependent on radiation dose. The phosphorylation was observed immediately after irradiation and remained mostly unchanged for up to 4 h. The phosphorylation was inhibited by DNA-PK inhibitor NU7441 and was undetectable in DNA-PKcs-deficient cells, indicating that the phosphorylation was mainly mediated by DNA-PK. These results suggested potential usefulness of the phosphorylation status of XRCC4 Ser320 as an indicator of DNA-PK functionality in living cells

  13. Au coated PS nanopillars as a highly ordered and reproducible SERS substrate

    Science.gov (United States)

    Kim, Yong-Tae; Schilling, Joerg; Schweizer, Stefan L.; Sauer, Guido; Wehrspohn, Ralf B.

    2017-07-01

    Noble metal nanostructures with nanometer gap size provide strong surface-enhanced Raman scattering (SERS) which can be used to detect trace amounts of chemical and biological molecules. Although several approaches were reported to obtain active SERS substrates, it still remains a challenge to fabricate SERS substrates with high sensitivity and reproducibility using low-cost techniques. In this article, we report on the fabrication of Au sputtered PS nanopillars based on a template synthetic method as highly ordered and reproducible SERS substrates. The SERS substrates are fabricated by anodic aluminum oxide (AAO) template-assisted infiltration of polystyrene (PS) resulting in hemispherical structures, and a following Au sputtering process. The optimum gap size between adjacent PS nanopillars and thickness of the Au layers for high SERS sensitivity are investigated. Using the Au sputtered PS nanopillars as an active SERS substrate, the Raman signal of 4-methylbenzenethiol (4-MBT) with a concentration down to 10-9 M is identified with good signal reproducibility, showing great potential as promising tool for SERS-based detection.

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

    DEFF Research Database (Denmark)

    Jensen, Annie Aarup; Løhr, Mille; Eriksen, Louise

    2012-01-01

    of the comet assay. We collected blood samples from 1,019 healthy subjects and genotyped for the OGG1 Ser326Cys polymorphism. We found 49 subjects homozygous for the variant genotype (Cys/Cys) and selected same numbers of age-matched subjects with the heterozygous (Ser/Cys) and homozygous wild-type genotype...

  15. Development of surface enhanced Raman scattering (SERS) spectroscopy monitoring of fuel markers to prevent fraud

    Science.gov (United States)

    Wilkinson, Timothy; Clarkson, John; White, Peter C.; Meakin, Nicholas; McDonald, Ken

    2013-05-01

    Governments often tax fuel products to generate revenues to support and stimulate their economies. They also subsidize the cost of essential fuel products. Fuel taxation and subsidization practices are both subject to fraud. Oil marketing companies also suffer from fuel fraud with loss of legitimate sales and additional quality and liability issues. The use of an advanced marking system to identify and control fraud has been shown to be effective in controlling illegal activity. DeCipher has developed surface enhanced Raman scattering (SERS) spectroscopy as its lead technology for measuring markers in fuel to identify and control malpractice. SERS has many advantages that make it highly suitable for this purpose. The SERS instruments are portable and can be used to monitor fuel at any point in the supply chain. SERS shows high specificity for the marker, with no false positives. Multiple markers can also be detected in a single SERS analysis allowing, for example, specific regional monitoring of fuel. The SERS analysis from fuel is also quick, clear and decisive, with a measurement time of less than 5 minutes. We will present results highlighting our development of the use of a highly stable silver colloid as a SERS substrate to measure the markers at ppb levels. Preliminary results from the use of a solid state SERS substrate to measure fuel markers will also be presented.

  16. SERS detection of the biomarker hydrogen cyanide from Pseudomonas aeruginosa cultures isolated from cystic fibrosis patients

    DEFF Research Database (Denmark)

    Lauridsen, Rikke Kragh; Madsen Sommer, Lea Mette; Johansen, Helle Krogh

    2017-01-01

    . The P. aeruginosa biomarker hydrogen cyanide (HCN) contains a triple bond, which is utilized in this study because of the resulting characteristic C≡N peak at 2135 cm-1 in a Raman spectrum. The Raman signal was enhanced by surface-enhanced Raman spectroscopy (SERS) on a Au-coated SERS substrate. After...

  17. 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

  18. Parameter optimization for Ag-coated TiO2 nanotube arrays as recyclable SERS substrates

    Science.gov (United States)

    Sun, Yuyang; Yang, Lulu; Liao, Fan; Dang, Qian; Shao, Mingwang

    2018-06-01

    The Ag-coated titanium dioxide nanotube arrays (Ag-coated TNTs) are obtained via the deposition of Ag nanoparticles on the two-step anodized TNTs. The wall thickness of TNTs is modulated via finite difference time domain simulation to get the favorable electromagnetic field for surface enhanced Raman scattering (SERS). Ag-coated TNTs with optimal wall thickness of 20 nm were employed as the SERS substrates to detect 2-mercaptobenzoxazole, which show superior detection sensitivity and uniformity. In addition, due to the photocatalysis of TNTs, the SERS substrates could clean themselves and be repeatedly used by photo-degradation of target molecules under the ultra-violet irradiation. The Ag-coated TNTs are a kind of bifunctional SERS substrates which can produce high-quality SERS signals and reuse to reduce the cost.

  19. A Sensitive Gold Nanoplasmonic SERS Quantitative Analysis Method for Sulfate in Serum Using Fullerene as Catalyst

    Directory of Open Access Journals (Sweden)

    Chongning Li

    2018-04-01

    Full Text Available Fullerene exhibited strong catalysis of the redox reaction between HAuCl4 and trisodium citrate to form gold nanoplasmon with a strong surface-enhanced Raman scattering (SERS effect at 1615 cm−1 in the presence of Vitoria blue B molecule probes. When fullerene increased, the SERS peak enhanced linearly due to formation of more AuNPs as substrate. Upon addition of Ba2+, Ba2+ ions adsorb on the fullerene surface to inhibit the catalysis of fullerene that caused the SERS peak decreasing. Analyte SO42− combined with Ba2+ to form stable BaSO4 precipitate to release free fullerene that the catalysis recovered, and the SERS intensity increased linearly. Thus, a new SERS quantitative analysis method was established for the detection of sulfate in serum samples, with a linear range of 0.03–3.4 μM.

  20. 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.

  1. 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.

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

    KAUST Repository

    Kessentini, Sameh; Barchiesi, Dominique; D'Andrea, Cristiano; Toma, Andrea; Guillot, Nicolas; Di Fabrizio, Enzo M.; Fazio, Barbara; Maragó , Onofrio M.; Gucciardi, Pietro Giuseppe; Lamy De La Chapelle, Marc L.

    2014-01-01

    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.

  3. Dynamic phosphorylation of RelA on Ser42 and Ser45 in response to TNFα stimulation regulates DNA binding and transcription.

    Science.gov (United States)

    Lanucara, Francesco; Lam, Connie; Mann, Jelena; Monie, Tom P; Colombo, Stefano A P; Holman, Stephen W; Boyd, James; Dange, Manohar C; Mann, Derek A; White, Michael R H; Eyers, Claire E

    2016-07-01

    The NF-κB signalling module controls transcription through a network of protein kinases such as the IKKs, as well as inhibitory proteins (IκBs) and transcription factors including RelA/p65. Phosphorylation of the NF-κB subunits is critical for dictating system dynamics. Using both non-targeted discovery and quantitative selected reaction monitoring-targeted proteomics, we show that the cytokine TNFα induces dynamic multisite phosphorylation of RelA at a number of previously unidentified residues. Putative roles for many of these phosphorylation sites on RelA were predicted by modelling of various crystal structures. Stoichiometry of phosphorylation determination of Ser45 and Ser42 revealed preferential early phosphorylation of Ser45 in response to TNFα. Quantitative analyses subsequently confirmed differential roles for pSer42 and pSer45 in promoter-specific DNA binding and a role for both of these phosphosites in regulating transcription from the IL-6 promoter. These temporal dynamics suggest that RelA-mediated transcription is likely to be controlled by functionally distinct NF-κB proteoforms carrying different combinations of modifications, rather than a simple 'one modification, one effect' system. © 2016 The Authors.

  4. 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.

  5. Analytical characterization using surface-enhanced Raman scattering (SERS) and microfluidic sampling

    International Nuclear Information System (INIS)

    Wang, Chao; Yu, Chenxu

    2015-01-01

    With the rapid development of analytical techniques, it has become much easier to detect chemical and biological analytes, even at very low detection limits. In recent years, techniques based on vibrational spectroscopy, such as surface enhanced Raman spectroscopy (SERS), have been developed for non-destructive detection of pathogenic microorganisms. SERS is a highly sensitive analytical tool that can be used to characterize chemical and biological analytes interacting with SERS-active substrates. However, it has always been a challenge to obtain consistent and reproducible SERS spectroscopic results at complicated experimental conditions. Microfluidics, a tool for highly precise manipulation of small volume liquid samples, can be used to overcome the major drawbacks of SERS-based techniques. High reproducibility of SERS measurement could be obtained in continuous flow generated inside microfluidic devices. This article provides a thorough review of the principles, concepts and methods of SERS-microfluidic platforms, and the applications of such platforms in trace analysis of chemical and biological analytes. (topical review)

  6. Development of an optical fiber SERS microprobe for minimally invasive sensing applications

    Science.gov (United States)

    Mamun, Md Abdullah Al; Juodkazis, Saulius; Mahadevan-Jansen, Anita; Stoddart, Paul R.

    2018-02-01

    Numerous potential biomedical sensing applications of surface-enhanced Raman scattering (SERS) have been reported, but its practical use has been limited by the lack of a robust sensing platform. Optical fiber SERS probes show great promise, but are limited by the prominent silica Raman background, which requires the use of bulky optics for filtering the signal collection and excitation delivery paths. In the present study, a SERS microprobe has been designed and developed to eliminate the bottlenecks outlined above. For efficient excitation and delivery of the SERS signal, both hollow core photonic crystal fiber and double clad fiber have been investigated. While the hollow core fiber was still found to have excessive silica background, the double clad fiber allows efficient signal collection via the multi-mode inner cladding. A micro filtering mechanism has been designed, which can be integrated into the tip of the optical fiber SERS probe, providing filtering to suppress silica Raman background and thus avoiding the need for bulky optics. The design also assists in the efficient collection of SERS signal from the sample by rejecting Rayleigh scattered light from the sample. Optical fiber cleaving using ultra-short laser pulses was tested for improved control of the fiber tip geometry. With this miniaturized and integrated filtering mechanism, it is expected that the developed probe will promote the use of SERS for minimally invasive biomedical monitoring and sensing applications in future. The probe could potentially be placed inside a small gauge hypodermic needle and would be compatible with handheld portable spectrometers.

  7. 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

  8. 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).

  9. 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

  10. 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”,

  11. Design of SERS nanoprobes for Raman imaging: materials, critical factors and architectures.

    Science.gov (United States)

    Li, Mingwang; Qiu, Yuanyuan; Fan, Chenchen; Cui, Kai; Zhang, Yongming; Xiao, Zeyu

    2018-05-01

    Raman imaging yields high specificity and sensitivity when compared to other imaging modalities, mainly due to its fingerprint signature. However, intrinsic Raman signals are weak, thus limiting medical applications of Raman imaging. By adsorbing Raman molecules onto specific nanostructures such as noble metals, Raman signals can be significantly enhanced, termed surface-enhanced Raman scattering (SERS). Recent years have witnessed great interest in the development of SERS nanoprobes for Raman imaging. Rationally designed SERS nanoprobes have greatly enhanced Raman signals by several orders of magnitude, thus showing great potential for biomedical applications. In this review we elaborate on recent progress in design strategies with emphasis on material properties, modifying factors, and structural parameters.

  12. Nanosphere Lithography on Fiber: Towards Engineered Lab-On-Fiber SERS Optrodes

    Directory of Open Access Journals (Sweden)

    Giuseppe Quero

    2018-02-01

    Full Text Available In this paper we report on the engineering of repeatable surface enhanced Raman scattering (SERS optical fiber sensor devices (optrodes, as realized through nanosphere lithography. The Lab-on-Fiber SERS optrode consists of polystyrene nanospheres in a close-packed arrays configuration covered by a thin film of gold on the optical fiber tip. The SERS surfaces were fabricated by using a nanosphere lithography approach that is already demonstrated as able to produce highly repeatable patterns on the fiber tip. In order to engineer and optimize the SERS probes, we first evaluated and compared the SERS performances in terms of Enhancement Factor (EF pertaining to different patterns with different nanosphere diameters and gold thicknesses. To this aim, the EF of SERS surfaces with a pitch of 500, 750 and 1000 nm, and gold films of 20, 30 and 40 nm have been retrieved, adopting the SERS signal of a monolayer of biphenyl-4-thiol (BPT as a reliable benchmark. The analysis allowed us to identify of the most promising SERS platform: for the samples with nanospheres diameter of 500 nm and gold thickness of 30 nm, we measured values of EF of 4 × 105, which is comparable with state-of-the-art SERS EF achievable with highly performing colloidal gold nanoparticles. The reproducibility of the SERS enhancement was thoroughly evaluated. In particular, the SERS intensity revealed intra-sample (i.e., between different spatial regions of a selected substrate and inter-sample (i.e., between regions of different substrates repeatability, with a relative standard deviation lower than 9 and 15%, respectively. Finally, in order to determine the most suitable optical fiber probe, in terms of excitation/collection efficiency and Raman background, we selected several commercially available optical fibers and tested them with a BPT solution used as benchmark. A fiber probe with a pure silica core of 200 µm diameter and high numerical aperture (i.e., 0.5 was found to be the

  13. [Preparation of a kind of SERS-active substrates for spot fast analysis].

    Science.gov (United States)

    Ji, Nan; Li, Zhi-Shi; Zhao, Bing; Zou, Bo

    2013-02-01

    A kind of SERS-active substrates was prepared using chemical self-assembly method, aiming at spot fast analysis using portable Raman spectrometer. PDDA was first absorbed on the inner wall of vials, and then Ag colloids were assembled on the inner wall. UV-Vis spectra and Raman spectra of two kinds of blank vials were investigated and the transparent vials were thought to be better for SERS-vials. UV-Vis spectra were used to monitor the assembly process of Ag colloids. SERS activity of our substrates was characterized using p-ATP as probing molecules.

  14. Unidad did??ctica: concepciones filos??ficas del ser humano

    OpenAIRE

    Mart??nez Moreno, Roc??o

    2012-01-01

    Esta unidad did??ctica se justifica en tanto que ofrece la posibilidad de estudiar al ser humano desde varias perspectivas filos??ficas, consider??ndolo desde sus diferentes dimensiones. Esto nos aleja del dogmatismo o la creencia de que el ser humano es un constructo cerrado y definible. Quiz?? desde las ciencias nos acerquemos a una visi??n de lo que ??ste es en su versi??n mec??nica o biol??gica; pero no debemos olvidar que el ser humano tambi??n est?? sujeto al paso del tiempo, a la socie...

  15. 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.

  16. Application of surface-enhanced Raman spectroscopy (SERS) for cleaning verification in pharmaceutical manufacture.

    Science.gov (United States)

    Corrigan, Damion K; Cauchi, Michael; Piletsky, Sergey; Mccrossen, Sean

    2009-01-01

    Cleaning verification is the process by which pharmaceutical manufacturing equipment is determined as sufficiently clean to allow manufacture to continue. Surface-enhanced Raman spectroscopy (SERS) is a very sensitive spectroscopic technique capable of detection at levels appropriate for cleaning verification. In this paper, commercially available Klarite SERS substrates were employed in order to obtain the necessary enhancement of signal for the identification of chemical species at concentrations of 1 to 10 ng/cm2, which are relevant to cleaning verification. The SERS approach was combined with principal component analysis in the identification of drug compounds recovered from a contaminated steel surface.

  17. Visiones sobre la alteridad: la lectura sartreana de Ser y tiempo

    OpenAIRE

    Szeftel, Micaela

    2011-01-01

    Al abordar el estudio del Para-otro en El Ser y la Nada, Sartre reconoce la astucia que Heidegger tuvo al haber enunciado la “realidad-humana” como una relación de ser. La oposición entre sujeto y objeto, en la cual las teorías del conocimiento encuentran no sólo el fundamento del existir humano sino también el punto de partida para la pregunta por el ser, es reemplazada por un vínculo fundado en una esfera pre-ontológica. Mientras que Sartre considera que tanto Hegel como Husserl han quedado...

  18. 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...

  19. Comparison of time-gated surface-enhanced Raman spectroscopy (TG-SERS) and classical SERS based monitoring of Escherichia coli cultivation samples.

    Science.gov (United States)

    Kögler, Martin; Paul, Andrea; Anane, Emmanuel; Birkholz, Mario; Bunker, Alex; Viitala, Tapani; Maiwald, Michael; Junne, Stefan; Neubauer, Peter

    2018-06-08

    The application of Raman spectroscopy as a monitoring technique for bioprocesses is severely limited by a large background signal originating from fluorescing compounds in the culture media. Here we compare time-gated Raman (TG-Raman)-, continuous wave NIR-process Raman (NIR-Raman) and continuous wave micro-Raman (micro-Raman) approaches in combination with surface enhanced Raman spectroscopy (SERS) for their potential to overcome this limit. For that purpose, we monitored metabolite concentrations of Escherichia coli bioreactor cultivations in cell-free supernatant samples. We investigated concentration transients of glucose, acetate, AMP and cAMP at alternating substrate availability, from deficiency to excess. Raman and SERS signals were compared to off-line metabolite analysis of carbohydrates, carboxylic acids and nucleotides. Results demonstrate that SERS, in almost all cases, led to a higher number of identifiable signals and better resolved spectra. Spectra derived from the TG-Raman were comparable to those of micro-Raman resulting in well-discernable Raman peaks, which allowed for the identification of a higher number of compounds. In contrast, NIR-Raman provided a superior performance for the quantitative evaluation of analytes, both with and without SERS nanoparticles when using multivariate data analysis. This article is protected by copyright. All rights reserved. © 2018 American Institute of Chemical Engineers.

  20. 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.

  1. Nanosphere Templating Through Controlled Evaporation: A High Throughput Method For Building SERS Substrates

    Science.gov (United States)

    Alexander, Kristen; Hampton, Meredith; Lopez, Rene; Desimone, Joseph

    2009-03-01

    When a pair of noble metal nanoparticles are brought close together, the plasmonic properties of the pair (known as a ``dimer'') give rise to intense electric field enhancements in the interstitial gap. These fields present a simple yet exquisitely sensitive system for performing single molecule surface-enhanced Raman spectroscopy (SM-SERS). Problems associated with current fabrication methods of SERS-active substrates include reproducibility issues, high cost of production and low throughput. In this study, we present a novel method for the high throughput fabrication of high quality SERS substrates. Using a polymer templating technique followed by the placement of thiolated nanoparticles through meniscus force deposition, we are able to fabricate large arrays of identical, uniformly spaced dimers in a quick, reproducible manner. Subsequent theoretical and experimental studies have confirmed the strong dependence of the SERS enhancement on both substrate geometry (e.g. dimer size, shape and gap size) and the polarization of the excitation source.

  2. 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.

  3. 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...

  4. 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...... pathogens. In Listeria monocytogenes, several virulence genes, which depend on the transcription activator PrfA, are repressed by glucose, fructose, etc., in a catabolite repressor (CcpA)-independent mechanism. However, the catabolite co-repressor P-Ser-HPr was found to inhibit the activity of Prf...... is preceded by an operator site, which serves as target for the CcpA/P-Ser-HPr complex. Numerous Gram-negative pathogens also contain hprK, which is often organised in an operon with transcription regulators necessary for the development of virulence, indicating that in these organisms P-Ser-HPr also plays...

  5. 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.

  6. 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

  7. SERS imaging of cell-surface biomolecules metabolically labeled with bioorthogonal Raman reporters.

    Science.gov (United States)

    Xiao, Ming; Lin, Liang; Li, Zefan; Liu, Jie; Hong, Senlian; Li, Yaya; Zheng, Meiling; Duan, Xuanming; Chen, Xing

    2014-08-01

    Live imaging of biomolecules with high specificity and sensitivity as well as minimal perturbation is essential for studying cellular processes. Here, we report the development of a bioorthogonal surface-enhanced Raman scattering (SERS) imaging approach that exploits small Raman reporters for visualizing cell-surface biomolecules. The cells were cultured and imaged by SERS microscopy on arrays of Raman-enhancing nanoparticles coated on silicon wafers or glass slides. The Raman reporters including azides, alkynes, and carbondeuterium bonds are small in size and spectroscopically bioorthogonal (background-free). We demonstrated that various cell-surface biomolecules including proteins, glycans, and lipids were metabolically incorporated with the corresponding precursors bearing a Raman reporter and visualized by SERS microscopy. The coupling of SERS microscopy with bioorthogonal Raman reporters expands the capabilities of live-cell microscopy beyond the modalities of fluorescence and label-free imaging. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. 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.

  9. Neighboring phosphoSer-Pro motifs in the undefined domain of IRAK1 impart bivalent advantage for Pin1 binding.

    Science.gov (United States)

    Rogals, Monique J; Greenwood, Alexander I; Kwon, Jeahoo; Lu, Kun Ping; Nicholson, Linda K

    2016-12-01

    The peptidyl prolyl isomerase Pin1 has two domains that are considered to be its binding (WW) and catalytic (PPIase) domains, both of which interact with phosphorylated Ser/Thr-Pro motifs. This shared specificity might influence substrate selection, as many known Pin1 substrates have multiple sequentially close phosphoSer/Thr-Pro motifs, including the protein interleukin-1 receptor-associated kinase-1 (IRAK1). The IRAK1 undefined domain (UD) contains two sets of such neighboring motifs (Ser131/Ser144 and Ser163/Ser173), suggesting possible bivalent interactions with Pin1. Using a series of NMR titrations with 15N-labeled full-length Pin1 (Pin1-FL), PPIase, or WW domain and phosphopeptides representing the Ser131/Ser144 and Ser163/Ser173 regions of IRAK1-UD, bivalent interactions were investigated. Binding studies using singly phosphorylated peptides showed that individual motifs displayed weak affinities (> 100 μm) for Pin1-FL and each isolated domain. Analysis of dually phosphorylated peptides binding to Pin1-FL showed that inclusion of bivalent states was necessary to fit the data. The resulting complex model and fitted parameters were applied to predict the impact of bivalent states at low micromolar concentrations, demonstrating significant affinity enhancement for both dually phosphorylated peptides (3.5 and 24 μm for peptides based on the Ser131/Ser144 and Ser163/Ser173 regions, respectively). The complementary technique biolayer interferometry confirmed the predicted affinity enhancement for a representative set of singly and dually phosphorylated Ser131/Ser144 peptides at low micromolar concentrations, validating model predictions. These studies provide novel insights regarding the complexity of interactions between Pin1 and activated IRAK1, and more broadly suggest that phosphorylation of neighboring Ser/Thr-Pro motifs in proteins might provide competitive advantage at cellular concentrations for engaging with Pin1. © 2016 Federation of European

  10. Physikalische Grundlagen von chemischen Raman-Sensoren mit Schwerpunkt auf faseroptischen SERS-Sonden

    OpenAIRE

    Viets, Carmen

    2001-01-01

    Faseroptische SERS-Sensoren wurden durch die Beschichtung der Endflächen von optischen Fasern mit rauhen Metallfilmen erzeugt. Zu den verschiedenen Präparationstechniken, die angewendet und verglichen wurden, gehörten das langsame Aufdampfen von Metall-Inselfilmen und das Bedampfen von Nanopartikeln, aufgerauhten oder elektronenlithographisch strukturierten Oberflächen mit Metallfilmen. Der Einfluß der Laserleistung auf die Messungen mit SERS-Sensoren wurde untersucht, und es wurden maximale ...

  11. CisSERS: Customizable In Silico Sequence Evaluation for Restriction Sites.

    Directory of Open Access Journals (Sweden)

    Richard M Sharpe

    Full Text Available High-throughput sequencing continues to produce an immense volume of information that is processed and assembled into mature sequence data. Data analysis tools are urgently needed that leverage the embedded DNA sequence polymorphisms and consequent changes to restriction sites or sequence motifs in a high-throughput manner to enable biological experimentation. CisSERS was developed as a standalone open source tool to analyze sequence datasets and provide biologists with individual or comparative genome organization information in terms of presence and frequency of patterns or motifs such as restriction enzymes. Predicted agarose gel visualization of the custom analyses results was also integrated to enhance the usefulness of the software. CisSERS offers several novel functionalities, such as handling of large and multiple datasets in parallel, multiple restriction enzyme site detection and custom motif detection features, which are seamlessly integrated with real time agarose gel visualization. Using a simple fasta-formatted file as input, CisSERS utilizes the REBASE enzyme database. Results from CisSERS enable the user to make decisions for designing genotyping by sequencing experiments, reduced representation sequencing, 3'UTR sequencing, and cleaved amplified polymorphic sequence (CAPS molecular markers for large sample sets. CisSERS is a java based graphical user interface built around a perl backbone. Several of the applications of CisSERS including CAPS molecular marker development were successfully validated using wet-lab experimentation. Here, we present the tool CisSERS and results from in-silico and corresponding wet-lab analyses demonstrating that CisSERS is a technology platform solution that facilitates efficient data utilization in genomics and genetics studies.

  12. CisSERS: Customizable In Silico Sequence Evaluation for Restriction Sites.

    Science.gov (United States)

    Sharpe, Richard M; Koepke, Tyson; Harper, Artemus; Grimes, John; Galli, Marco; Satoh-Cruz, Mio; Kalyanaraman, Ananth; Evans, Katherine; Kramer, David; Dhingra, Amit

    2016-01-01

    High-throughput sequencing continues to produce an immense volume of information that is processed and assembled into mature sequence data. Data analysis tools are urgently needed that leverage the embedded DNA sequence polymorphisms and consequent changes to restriction sites or sequence motifs in a high-throughput manner to enable biological experimentation. CisSERS was developed as a standalone open source tool to analyze sequence datasets and provide biologists with individual or comparative genome organization information in terms of presence and frequency of patterns or motifs such as restriction enzymes. Predicted agarose gel visualization of the custom analyses results was also integrated to enhance the usefulness of the software. CisSERS offers several novel functionalities, such as handling of large and multiple datasets in parallel, multiple restriction enzyme site detection and custom motif detection features, which are seamlessly integrated with real time agarose gel visualization. Using a simple fasta-formatted file as input, CisSERS utilizes the REBASE enzyme database. Results from CisSERS enable the user to make decisions for designing genotyping by sequencing experiments, reduced representation sequencing, 3'UTR sequencing, and cleaved amplified polymorphic sequence (CAPS) molecular markers for large sample sets. CisSERS is a java based graphical user interface built around a perl backbone. Several of the applications of CisSERS including CAPS molecular marker development were successfully validated using wet-lab experimentation. Here, we present the tool CisSERS and results from in-silico and corresponding wet-lab analyses demonstrating that CisSERS is a technology platform solution that facilitates efficient data utilization in genomics and genetics studies.

  13. 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

    chemical sensing layer for the enrichment of gas molecules on sensor surface. The leaning nano-pillar substrate also showed highly reproducible SERS signal in cyclic VOCs detection, which can reduce the detection cost in practical applications. Further, multiplex SERS detection on different combination...... device for multiplex, specific and highly sensitive detection of complex VOCs samples that can find potential applications in exhaled breath analysis, hazardous gas analysis, homeland security and environmental monitoring....

  14. 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.

  15. Analysis of silver nanoparticles in antimicrobial products using surface-enhanced Raman spectroscopy (SERS).

    Science.gov (United States)

    Guo, Huiyuan; Zhang, Zhiyun; Xing, Baoshan; Mukherjee, Arnab; Musante, Craig; White, Jason C; He, Lili

    2015-04-07

    Silver nanoparticles (AgNPs) are the most commonly used nanoparticles in consumer products. Concerns over human exposure to and risk from these particles have resulted in increased interest in novel strategies to detect AgNPs. This study investigated the feasibility of surface-enhanced Raman spectroscopy (SERS) as a method for the detection and quantification of AgNPs in antimicrobial products. By using ferbam (ferric dimethyl-dithiocarbamate) as an indicator molecule that binds strongly onto the nanoparticles, AgNPs detection and discrimination were achieved based on the signature SERS response of AgNPs-ferbam complexes. SERS response with ferbam was distinct for silver ions, silver chloride, silver bulk particles, and AgNPs. Two types of AgNPs with different coatings, citrate and polyvinylpirrolidone (PVP), both showed strong interactions with ferbam and induced strong SERS signals. SERS was effectively applicable for detecting Ag particles ranging from 20 to 200 nm, with the highest signal intensity in the 60-100 nm range. A linear relationship (R(2) = 0.9804) between Raman intensity and citrate-AgNPs concentrations (60 nm; 0-20 mg/L) indicates the potential for particle quantification. We also evaluated SERS detection of AgNPs in four commercially available antimicrobial products. Combined with ICP-MS and TEM data, the results indicated that the SERS response is primarily dependent on size, but also affected by AgNPs concentration. The findings demonstrate that SERS is a promising analytical platform for studying environmentally relevant levels of AgNPs in consumer products and related matrices.

  16. [Study on the ingredients of reserpine by TLC-FT-SERS].

    Science.gov (United States)

    Wang, Y; Zi, F; Wang, Y; Zhao, Y; Zhang, X; Weng, S

    1999-12-01

    A new method for analysing the ingredients of reserpine by thin layer chromatography (TLC) and surface-enhanced Raman spectroscopy (SERS) is reported in this paper. The results show that the characteristic spectral bands of reserpine satuated at the thin layer with the amount of sample about 2 microg were obtained. The difference between SERS and solid spectra was found. An absorption model of reserpine and silver sol was proposed. This method can be used to analyse the chemical ingredients with high sensitivity.

  17. Modification of the SERS spectrum of cyanide traces due to complex formation between cyanide and silver

    Science.gov (United States)

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

    2018-06-01

    It is well known that cyanide is an extremely toxic lethal poison with human death within minutes after exposure to only 300 ppm cyanide. On the other hand, cyanide is released into the environment (mainly through waste water) every day from various human activities. Therefore, rapid, sensitive and cost-effective cyanide trace detection is an urgent need. Surface-enhanced Raman scattering (SERS) is a method that meets these requirements. It should be noted, however, that in this technique SERS substrates, which are usually made of gold or silver, will be leached with aqueous cyanide by the formation of complexes between gold or silver with cyanide. This will cause the SERS spectrum of cyanide to be modified. When determining cyanide concentrations by SERS analysis, this spectral modification should be taken into account. This report presents the SERS spectral modification of aqueous cyanide traces (in ppm and lower concentration range) when the SERS substrates used are flower-like silver micro-structures.

  18. A practicable detection system for genetically modified rice by SERS-barcoded nanosensors.

    Science.gov (United States)

    Chen, Kun; Han, Heyou; Luo, Zhihui; Wang, Yanjun; Wang, Xiuping

    2012-04-15

    Since the global cultivation of genetically modified crops constantly expands, it remains a high demand to establish different ways to sort food and feed that consist or contain genetically modified organisms. Surface-enhanced Raman scattering (SERS) spectroscopy is a flexible tool for biological analysis due to its excellent properties for detecting wide varieties of target biomolecules including nucleic acids. In the present study, a SERS-barcoded nanosensor was developed to detect Bacillus thuringiensis (Bt) gene-transformed rice expressing insecticidal proteins. The barcoded sensor was designed by encapsulation of gold nanoparticles with silica and conjugation of oligonucleotide strands for targeting DNA strands. The transition between the cry1A(b) and cry1A(c) fusion gene sequence was used to construct a specific SERS-based detection method with a detection limit of 0.1 pg/mL. In order to build the determination models to screen transgene, a series mixture of Bt rice and normal rice were prepared for SERS assay, and the limit of detection was 0.1% (w/w) transgenic Bt rice relative to normal rice. The sensitivity and accuracy of the SERS-based assay was comparable with real-time PCR. The SERS-barcoded analytical method would provide precise detection of transgenic rice varieties but also informative supplement to avoid false positive outcomes. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  19. 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.

  20. 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.

  1. Colorimetry and SERS dual-mode detection of telomerase activity: combining rapid screening with high sensitivity.

    Science.gov (United States)

    Zong, Shenfei; Wang, Zhuyuan; Chen, Hui; Hu, Guohua; Liu, Min; Chen, Peng; Cui, Yiping

    2014-01-01

    As an important biomarker and therapeutic target, telomerase has attracted considerable attention concerning its detection and monitoring. Here, we present a colorimetry and surface enhanced Raman scattering (SERS) dual-mode telomerase activity detection method, which has several distinctive advantages. First, colorimetric functionality allows rapid preliminary discrimination of telomerase activity by the naked eye. Second, the employment of SERS technique results in greatly improved detection sensitivity. Third, the combination of colorimetry and SERS into one detection system can ensure highly efficacious and sensitive screening of numerous samples. Besides, the avoidance of polymerase chain reaction (PCR) procedures further guarantees fine reliability and simplicity. Generally, the presented method is realized by an "elongate and capture" procedure. To be specific, gold nanoparticles modified with Raman molecules and telomeric repeat complementary oligonucleotide are employed as the colorimetric-SERS bifunctional reporting nanotag, while magnetic nanoparticles functionalized with telomerase substrate oligonucleotide are used as the capturing substrate. Telomerase can synthesize and elongate telomeric repeats onto the capturing substrate. The elongated telomeric repeats subsequently facilitate capturing of the reporting nanotag via hybridization between telomeric repeat and its complementary strand. The captured nanotags can cause a significant difference in the color and SERS intensity of the magnetically separated sediments. Thus both the color and SERS can be used as indicators of the telomerase activity. With fast screening ability and outstanding sensitivity, we anticipate that this method would greatly promote practical application of telomerase-based early-stage cancer diagnosis.

  2. 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.

  3. 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.

  4. Biofabrication of chitosan-silver composite SERS substrates enabling quantification of adenine by a spectroscopic shift

    International Nuclear Information System (INIS)

    Luo, X L; Bentley, W E; Buckhout-White, S; Rubloff, G W

    2011-01-01

    Surface-enhanced Raman scattering (SERS) has grown dramatically as an analytical tool for the sensitive and selective detection of molecules adsorbed on nano-roughened noble metal structures. Quantification with SERS based on signal intensity remains challenging due to the complicated fabrication process to obtain well-dispersed nanoparticles and well-ordered substrates. We report a new biofabrication strategy of SERS substrates that enable quantification through a newly discovered spectroscopic shift resulting from the chitosan-analyte interactions in solution. We demonstrate this phenomenon by the quantification of adenine, which is an essential part of the nucleic acid structure and a key component in pathways which generate signal molecules for bacterial communications. The SERS substrates were fabricated simply by sequential electrodeposition of chitosan on patterned gold electrodes and electroplating of a silver nitrate solution through the chitosan scaffold to form a chitosan-silver nanoparticle composite. Active SERS signals of adenine solutions were obtained in real time from the chitosan-silver composite substrates with a significant concentration-dependent spectroscopic shift. The Lorentzian curve fitting of the dominant peaks suggests the presence of two separate peaks with a concentration-dependent area percentage of the separated peaks. The chitosan-mediated composite SERS substrates can be easily biofabricated on predefined electrodes within microfluidic channels for real-time detection in microsystems.

  5. 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.

  6. Chemically Roughened Solid Silver: A Simple, Robust and Broadband SERS Substrate

    Directory of Open Access Journals (Sweden)

    Shavini Wijesuriya

    2016-10-01

    Full Text Available Surface-enhanced Raman spectroscopy (SERS substrates manufactured using complex nano-patterning techniques have become the norm. However, their cost of manufacture makes them unaffordable to incorporate into most biosensors. The technique shown in this paper is low-cost, reliable and highly sensitive. Chemical etching of solid Ag metal was used to produce simple, yet robust SERS substrates with broadband characteristics. Etching with ammonium hydroxide (NH4OH and nitric acid (HNO3 helped obtain roughened Ag SERS substrates. Scanning electron microscopy (SEM and interferometry were used to visualize and quantify surface roughness. Flattened Ag wires had inherent, but non-uniform roughness having peaks and valleys in the microscale. NH4OH treatment removed dirt and smoothened the surface, while HNO3 treatment produced a flake-like morphology with visibly more surface roughness features on Ag metal. SERS efficacy was tested using 4-methylbenzenethiol (MBT. The best SERS enhancement for 1 mM MBT was observed for Ag metal etched for 30 s in NH4OH followed by 10 s in HNO3. Further, MBT could be quantified with detection limits of 1 pM and 100 µM, respectively, using 514 nm and 1064 nm Raman spectrometers. Thus, a rapid and less energy intensive method for producing solid Ag SERS substrate and its efficacy in analyte sensing was demonstrated.

  7. Intracellular surface-enhanced Raman scattering (SERS) with thermally stable gold nanoflowers grown from Pt and Pd seeds

    KAUST Repository

    Song, Hyon Min; Deng, Lin; Khashab, Niveen M.

    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

  8. SERS study of transformation of phenylalanine to tyrosine under particle irradiation

    Science.gov (United States)

    Zhang, Jingjing; Huang, Qing; Yao, Guohua; Ke, Zhigang; Zhang, Hong; Lu, Yilin

    2014-08-01

    Surface enhanced Raman scattering or spectroscopy (SERS) is a very powerful analytical tool which has been widely applied in many scientific research and application fields. It is therefore also very intriguing for us to introduce SERS technique in the radiobiological research, where in many cases only a very few of biomolecules are subjected to changes which however can lead to significant biological effects. The radiation induced biochemical reactions are normally very sophisticated with different substances produced in the system, so currently it is still a big challenge for SERS to analyze such a mixture system which contains multiple analytes. In this context, this work aimed to establish and consolidate the feasibility of SERS as an effective tool in radiation chemistry, and this purpose, we employed SERS as a sensitive probe to a known process, namely, the oxidation of phenylalanine (Phe) under particle irradiation, where the energetic particles were obtained from either plasma discharge or electron-beam. During the irradiation, three types of tyrosine (Tyr), namely, p-Tyr, m-Tyr and o-Tyr were produced, and all these tyrosine isomers together with Phe could be identified and measured based on the SERS spectral analysis of the corresponding enhanced characteristic signals, namely, 1002 cm-1 for Phe, 1161 cm-1 for p-Tyr, 990 cm-1 for m-Tyr, and 970 cm-1 for o-Tyr, respectively. The estimation of the quantities of different tyrosine isomers were also given and verified by conventional method such as high performance liquid chromatography (HPLC). As for comparison of different ways of particle irradiation, our results also indicated that electron-beam irradiation was more efficient for converting Phe into Tyr than plasma discharge treatment, confirming the role of hydroxyl radicals in the Phe-Tyr conformation. Therefore, our work has not only demonstrated that SERS can be successfully applied in the radiobiological study, but also given insights into the

  9. Association of the hOGG1 Ser326Cys polymorphism with sporadic amyotrophic lateral sclerosis.

    Science.gov (United States)

    Coppedè, Fabio; Mancuso, Michelangelo; Lo Gerfo, Annalisa; Carlesi, Cecilia; Piazza, Selina; Rocchi, Anna; Petrozzi, Lucia; Nesti, Claudia; Micheli, Dario; Bacci, Andrea; Migliore, Lucia; Murri, Luigi; Siciliano, Gabriele

    2007-06-13

    Amyotropic lateral sclerosis (ALS) is a fatal and progressive neurodegenerative disease causing the loss of motoneurons of the brain and the spinal cord. The etiology of ALS is still uncertain, but males are at increased risk for the disease than females. Several studies have suggested that motoneurons in ALS might be subjected to the double insult of increased DNA oxidative damage and deficiencies in DNA repair systems. Particularly, increased levels of 8-oxoguanine and impairments of the DNA base excision repair system have been observed in neurons of ALS patients. There is evidence that the Ser326Cys polymorphism of the human 8-oxoguanine DNA glycosylase 1 (hOGG1) gene is associated with a reduced DNA repair activity. To evaluate the role of the hOGG1 Ser326Cys polymorphism in sporadic ALS (sALS), we screened 136 patients and 129 matched controls. In the total population, we observed association between both the Cys326 allele (p=0.02) and the combined Ser326Cys+Cys326Cys genotype (OR=1.65, 95% CI=1.06-2.88) and increased risk of disease. After stratification by gender, the Cys326 allele (p=0.01), both the Ser326Cys genotype (OR=2.14, 95% CI=1.09-4.19) and the combined Ser326Cys+Cys326Cys genotype (OR=2.15, 95% CI=1.16-4.01) were associated with sALS risk only in males. No significant association between the Ser326Cys polymorphism and disease phenotype, including age and site of onset and disease progression, was observed. Present results suggest a possible involvement of the hOGG1 Ser326Cys polymorphism in sALS pathogenesis.

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

    International Nuclear Information System (INIS)

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

    2017-01-01

    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 AgNO_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.

  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. 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.

  13. A study on the correlation between the dewetting temperature of Ag film and SERS intensity.

    Science.gov (United States)

    Quan, Jiamin; Zhang, Jie; Qi, Xueqiang; Li, Junying; Wang, Ning; Zhu, Yong

    2017-11-07

    The thermally dewetted metal nano-islands have been actively investigated as cost-effective SERS-active substrates with a large area, good reproducibility and repeatability via simple fabrication process. However, the correlation between the dewetting temperature of metal film and SERS intensity hasn't been systematically studied. In this work, taking Ag nano-islands (AgNIs) as an example, we reported a strategy to investigate the correlation between the dewetting temperature of metal film and SERS intensity. We described the morphology evolution of AgNIs on the SiO 2 planar substrate in different temperatures and got the quantitative information in surface-limited diffusion process (SLDP) as a function of annealing temperature via classical mean-field nucleation theory. Those functions were further used in the simulation of electromagnetic field to obtain the correlation between the dewetting temperature of Ag film and theoretical analysis. In addition, Raman mapping was done on samples annealed at different temperatures, with R6G as an analyte, to accomplish the analysis of the correlation between the dewetting temperature of Ag film and SERS intensity, which is consistent with the theoretical analysis. For SLDP, we used the morphological characterization of five samples prepared by different annealing temperatures to successfully illustrate the change in SERS intensity with the temperature fluctuation, obtaining a small deviation between the experimental results and theoretic prediction.

  14. Effect of the size of silver nanoparticles on SERS signal enhancement

    Science.gov (United States)

    He, Rui Xiu; Liang, Robert; Peng, Peng; Norman Zhou, Y.

    2017-08-01

    The localized surface plasmon resonance arising from plasmonic materials is beneficial in solution-based and thin-film sensing applications, which increase the sensitivity of the analyte being tested. Silver nanoparticles from 35 to 65 nm in diameter were synthesized using a low-temperature method and deposited in a monolayer on a (3-aminopropyl)triethoxysilane (APTES)-functionalized glass slide. The effect of particle size on monolayer structure, optical behavior, and surface-enhanced Raman scattering (SERS) is studied. While increasing particle size decreases particle coverage, it also changes the localized surface plasmon resonance and thus the SERS activity of individual nanoparticles. Using a laser excitation wavelength of 633 nm, the stronger localized surface plasmon resonance coupling to this excitation wavelength at larger particle sizes trumps the loss in surface coverage, and greater SERS signals are observed. The SERS signal enhancement accounts for the higher SERS signal, which was verified using a finite element model of a silver nanoparticle dimer with various nanoparticle sizes and separation distances.

  15. Rapid detection of acetamiprid in foods using surface-enhanced Raman spectroscopy (SERS).

    Science.gov (United States)

    Wijaya, Wisiani; Pang, Shintaro; Labuza, Theodore P; He, Lili

    2014-04-01

    Acetamiprid is a neonicotinoid pesticide that is commonly used in modern farming. Acetamiprid residue in food commodities can be a potential harm to human and has been implicated in the honey bee hive die off crisis. In this study, we developed rapid, simple, and sensitive methods to detect acetamiprid in apple juice and on apple surfaces using surface-enhanced Raman spectroscopy (SERS). No pretreatment of apple juice sample was performed. A simple surface swab method was used to recover acetamiprid from the apple surface. Samples were incubated with silver dendrites for several minutes and SERS spectra were taken directly from the silver surface. Detection of a set of 5 apple juice samples can be done within 10 min. The swab-SERS method took 15 min for a set of 5 samples. Resulting spectral data were analyzed using principal component analysis. The highest acetamiprid peak at 634 cm(-1) was used to detect and quantify the amount of acetamiprid spiked in 1:1 water-methanol solvent, apple juice, and on apple surface. The SERS method was able to successfully detect acetamiprid at 0.5 μg/mL (0.5 ppm) in solvent, 3 μg/mL (3 ppm) in apple juice, and 0.125 μg/cm(2) on apple surfaces. The SERS methods provide simple, rapid, and sensitive ways to detect acetamiprid in beverages and on the surfaces of thick skinned fruits and vegetables. © 2014 Institute of Food Technologists®

  16. 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.

  17. Effects of surface topography on SERS response: Correlating nanoscopy with spectroscopy

    Science.gov (United States)

    Das, Sumit Kumar; Ghosh, Manash; Chowdhury, Joydeep

    2018-05-01

    This paper reports for the first time the hidden correlation between the topographical features of the bilayer Langmuir-Blodgett (LB) film substrates of stearic acid (SA) incubated in Au@Ag nanocolloids over various dipping times (DTs) with their corresponding SERS responses. The topographies of the as prepared substrates are investigated from the statistical considerations in terms of lateral correlation length, interface width, Hurst and Lyapnov exponents. The real space of the substrates are mapped directly from the FESEM and AFM images of the bilayer LB film of SA immersed in Au@Ag nanocolloids over various DTs ranging between 6 and 72 h. The SERS spectra of the Rhodamine 6G molecules adsorbed on the as prepared substrates have been reported. The statistical parameters of the substrates that exhibit maximum SERS efficacy have been suggested. The far field distributions in presence and in absence of Raman dipole together with spatial distribution of the near field from the hottest spot of the as prepared substrate have also been reported. To our knowledge, this is the first report that links nanoscopy with SERS spectroscopy from statistical considerations and is expected to open a new window towards the fabrication of more efficient and reproducible SERS active substrates in future endeavours.

  18. 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.

  19. 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.

  20. 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.

  1. Reproducible and recyclable SERS substrates: Flower-like Ag structures with concave surfaces formed by electrodeposition

    Science.gov (United States)

    Bian, Juncao; Shu, Shiwei; Li, Jianfu; Huang, Chao; Li, Yang Yang; Zhang, Rui-Qin

    2015-04-01

    Direct synthesis of three-dimensional Ag structures on solid substrates for the purposes of producing reproducible and recyclable surface-enhanced Raman scattering (SERS) applications remains challenging. In this work, flower-like Ag structures with concave surfaces (FACS) were successfully electrodeposited onto ITO glass using the double-potentiostatic method. The FACS, with an enhancement factor of the order of 108, exhibited a SERS signal intensity 3.3 times stronger than that measured from Ag nanostructures without concave surfaces. A cleaning procedure involving lengthy immersion of the sample in ethanol and KNO3 was proposed to recycle the substrate and confirmed by using rhodamine 6G, adenine, and 4-aminothiophenol as target molecules. The findings can help to advance the practical applications of Ag nanostructure-based SERS substrates.

  2. 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...

  3. Quantification of Protein Biomarker Using SERS Nano-Stress Sensing with Peak Intensity Ratiometry

    Science.gov (United States)

    Goh, Douglas; Kong, Kien Voon; Jayakumar, Perumal; Gong, Tianxun; Dinish, U. S.; Olivo, Malini

    We report a surface enhanced Raman spectroscopy (SERS) ratiometry method based on peak intensity coupled in a nano-stress sensing platform to detect and quantify biological molecules. Herein, we employed an antibody-conjugated p-aminothiophenol (ATP) functionalized on a bimetallic-film-over-nanosphere (BMFON) substrate as a sensitive SERS platform to detect human haptoglobin (Hp) protein, which is an acute phase protein and a biomarker for various cancers. Correlation between change in the ATP spectral characteristics and concentration of Hp protein was established by examining the peak intensity ratio at 1572cm-1 and 1592cm-1 that reflects the degree of stress experienced by the aromatic ring of ATP during Hp protein-antibody interaction. Development of this platform shows the potential in developing a low-cost and sensitive SERS sensor for the pre-screening of various biomarkers.

  4. Porous Au-Ag Nanospheres with High-Density and Highly Accessible Hotspots for SERS Analysis.

    Science.gov (United States)

    Liu, Kai; Bai, Yaocai; Zhang, Lei; Yang, Zhongbo; Fan, Qikui; Zheng, Haoquan; Yin, Yadong; Gao, Chuanbo

    2016-06-08

    Colloidal plasmonic metal nanoparticles have enabled surface-enhanced Raman scattering (SERS) for a variety of analytical applications. While great efforts have been made to create hotspots for amplifying Raman signals, it remains a great challenge to ensure their high density and accessibility for improved sensitivity of the analysis. Here we report a dealloying process for the fabrication of porous Au-Ag alloy nanoparticles containing abundant inherent hotspots, which were encased in ultrathin hollow silica shells so that the need of conventional organic capping ligands for stabilization is eliminated, producing colloidal plasmonic nanoparticles with clean surface and thus high accessibility of the hotspots. As a result, these novel nanostructures show excellent SERS activity with an enhancement factor of ∼1.3 × 10(7) on a single particle basis (off-resonant condition), promising high applicability in many SERS-based analytical and biomedical applications.

  5. 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.

  6. Effect of Etching on the Optical, Morphological Properties of Ag Thin Films for SERS Active Substrates

    Directory of Open Access Journals (Sweden)

    Desapogu Rajesh

    2013-01-01

    Full Text Available Structural, optical, and morphological properties of Ag thin films before and after etching were investigated by using X-ray diffraction, UV-Vis spectrophotometer, and field emission scanning electron microscopy (FESEM. The HNO3 roughened Ag thin films exhibit excellent enhancement features and better stability than pure Ag thin films. Further, the Ag nanostructures are covered with Rhodamine 6G (Rh6G and then tested with surface enhanced raman spectroscopy (SERS for active substrates. Etched Ag films were found to exhibit a strong SERS effect and excellent thermal stability. Hence, the present method is found to be useful in the development of plasmon-based analytical devices, especially SERS-based biosensors.

  7. Combining surface enhanced Raman scattering (SERS) and high-performance thin-layer chromatography (HPTLC)

    Science.gov (United States)

    Koglin, E.

    A new method for preparing SERS active surfaces using silver colloidal spheres deposited on HPTLC plates, used for thin-layer chromatography, is discussed in detail. The sensitivity of these activated HPTLC plates is so high that in-situ vibrational investigations of chromatogram spots are possible at the nanogram level. The HPTLC/SERS spectra of purine, benzoic acid and 1-nitro-pyrene adsorbed on silver colloidal activated silica gel plates are measured in the nanogram region. In addition we also report in this paper on the results of a feasibility study performed to evaluate the analytical potential of micro-Raman spectroscopy (triple monochromator, multichannel detection system) in SERS/HPTLC spot characterization. It permits the acquisition of Raman spectra from HPTLC spots down to 1 μm in size or other forms of microsamples approaching the picogram level in mass.

  8. Ultra-thin layer chromatography with integrated silver colloid-based SERS detection.

    Science.gov (United States)

    Wallace, Ryan A; Lavrik, Nickolay V; Sepaniak, Michael J

    2017-01-01

    Simplified lab-on-a-chip techniques are desirable for quick and efficient detection of analytes of interest in the field. The following work involves the use of deterministic pillar arrays on the micro-scale as a platform to separate compounds, and the use of Ag colloid within the arrays as a source of increased signal via surface enhanced Raman spectroscopy (SERS). One problem traditionally seen with SERS surfaces containing Ag colloid is oxidation; however, our platforms are superhydrophobic, reducing the amount of oxidation taking place on the surface of the Ag colloid. This work includes the successful separation and SERS detection of a fluorescent dye compounds (resorufin and sulforhodamine 640), fluorescent anti-tumor drugs (Adriamycin and Daunomycin), and purine and pyrimidine bases (adenine, cytosine, guanine, hypoxanthine, and thymine). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Controllable Ag nanostructure patterning in a microfluidic channel for real-time SERS systems.

    Science.gov (United States)

    Leem, Juyoung; Kang, Hyun Wook; Ko, Seung Hwan; Sung, Hyung Jin

    2014-03-07

    We present a microfluidic patterning system for fabricating nanostructured Ag thin films via a polyol method. The fabricated Ag thin films can be used immediately in a real-time SERS sensing system. The Ag thin films are formed on the inner surfaces of a microfluidic channel so that a Ag-patterned Si wafer and a Ag-patterned PDMS channel are produced by the fabrication. The optimum sensing region and fabrication duration for effective SERS detection were determined. As SERS active substrates, the patterned Ag thin films exhibit an enhancement factor (EF) of 4.25 × 10(10). The Ag-patterned polymer channel was attached to a glass substrate and used as a microfluidic sensing system for the real-time monitoring of biomolecule concentrations. This microfluidic patterning system provides a low-cost process for the fabrication of materials that are useful in medical and pharmaceutical detection and can be employed in mass production.

  10. 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.

  11. 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.

  12. Design of Hybrid Nanostructural Arrays to Manipulate SERS-Active Substrates by Nanosphere Lithography.

    Science.gov (United States)

    Zhao, Xiaoyu; Wen, Jiahong; Zhang, Mengning; Wang, Dunhui; Wang, Yaxin; Chen, Lei; Zhang, Yongjun; Yang, Jinghai; Du, Youwei

    2017-03-01

    An easy-handling and low-cost method is utilized to controllably fabricate nanopattern arrays as the surface-enhanced Raman scattering (SERS) active substrates with high density of SERS-active areas (hot spots). A hybrid silver array of nanocaps and nanotriangles are prepared by combining magnetron sputtering and plasma etching. By adjusting the etching time of polystyrene (PS) colloid spheres array in silver nanobowls, the morphology of the arrays can be easily manipulated to control the formation and distribution of hot spots. The experimental results show that the hybrid nanostructural arrays have large enhancement factor, which is estimated to be seven times larger than that in the array of nanocaps and three times larger than that in the array of nanorings and nanoparticles. According to the results of finite-difference time-domain simulation, the excellent SERS performance of this array is ascribed to the high density of hot spots and enhanced electromagnetic field.

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

    International Nuclear Information System (INIS)

    Chen, Kaihang; Shen, Zuguang; Luo, Jiwen; Wang, Xiaoying; Sun, Runcang

    2015-01-01

    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 3 ) 2 ] + , 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

  14. 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.

  15. 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.

  16. Project W-320, waste retrieval sluicing system: BIO/SER implementation matrices

    International Nuclear Information System (INIS)

    Bailey, J.W.

    1998-01-01

    This document provides verification that the safety related commitments specified in HNF-SD-WM-810-001, Addendum 1 for the Waste Retrieval Sluicing System, Project W-320 and Project W-320 Safety Evaluation Report (SER), have been implemented in the project hardware, procedures and administrative controls. Four appendices include matrices which show where the 810 commitments are implemented for limiting conditions of operation and surveillance requirements controls, administrative controls, defense-in-depth controls and controls discussed in 810 Addendum 1. A fifth appendix includes the implementation of Project W-320 SER issues and provisions

  17. SERS spectra of pyridine adsorbed on nickel film prepared by magnetron sputtering

    Science.gov (United States)

    Li, Daoyong; Ouyang, Yu; Chen, Li; Cao, Weiran; Shi, Shaohua

    2011-02-01

    As a repeating well and cheaper enhancement substrate, the nickel film was fabricated with magnetron sputtering coating instrument. Surface enhanced Raman spectra (SERS) of pyridine adsorbed on this nickel film are compared with the experimental values of gaseous pyridine, the theoretical value of pyridine solution listed in other literatures and our method is better than electro-chemical etching electrode method for large scale preparation. The enhancement factor of the nickel film is calculated and the result indicates that magnetron sputtering coating technology is feasible for obtaining good SERS active surface.

  18. 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..

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    in combination with previously published results. The Ser/Ser genotype was significantly associated with a reduced risk of hypertension and with lower systolic, diastolic, and mean arterial blood pressure levels, predominantly among women. Finally, in a combined analysis using data obtained in both sexes...... to elucidate the differential role of this polymorphism in men and women.......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...

  20. 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).

  1. 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

  2. Nanostructured Silver Substrates With Stable and Universal SERS Properties: Application to Organic Molecules and Semiconductor Nanoparticles

    Directory of Open Access Journals (Sweden)

    Waurisch C

    2009-01-01

    Full Text Available Abstract Nanostructured silver films have been prepared by thermal deposition on silicon, and their properties as SERS substrates investigated. The optimal conditions of the post-growth annealing of the substrates were established. Atomic force microscopy study revealed that the silver films with relatively dense and homogeneous arrays of 60–80-nm high pyramidal nanoislands are the most efficient for SERS of both organic dye and inorganic nanoparticles analytes. The noticeable enhancement of the Raman signal from colloidal nanoparticles with the help of silver island films is reported for the first time.

  3. 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

  4. 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

  5. Ser hombre o ser mujer a través de la música: una encuesta a jóvenes de Barcelona

    OpenAIRE

    Martí,Josep

    1999-01-01

    Este artigo trata da problemática da relação entre gênero e música. Sabemos que a música como meio de comunicação contribui também para a construção social da realidade; se nos interessamos pela música como fenômeno sócio-cultural, então o aspecto de gênero constitui uma dimensão que não pode ser ignorada. Ao longo deste artigo, apresentarei alguns dados relativos a uma pesquisa tipo survey realizada com...

  6. 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.

  7. Authoring Multiple "Formas de ser": Three Bilingual Latino/a Fifth Graders Navigating School

    Science.gov (United States)

    Cuero, Kimberley K.

    2009-01-01

    Drawing from sociocultural and anthropological perspectives, I present 3 case examples of bilingual, Mexican-origin students enrolled in a transitional bilingual educational program in an urban elementary school. By using the theoretical constructs of figured worlds, authoring, and "formas de ser" (ways of being), I examine how student identities…

  8. 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.

  9. Using Ag-embedded TiO{sub 2} nanotubes array as recyclable SERS substrate

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Yunhan, E-mail: yhling@mail.tsinghua.edu.cn [Lab of Advanced Materials, School of Materials Science & Engineering, Tsinghua University, Beijing 100084 (China); Zhuo, Yuqing; Huang, Liang [Lab of Advanced Materials, School of Materials Science & Engineering, Tsinghua University, Beijing 100084 (China); Mao, Duolu [School of Physical and Electronic Information Engineering, Qinghai Nationalities University, Xining, Qinghai 810007 (China)

    2016-12-01

    Highlights: • Ag embedded nanoparticles inside nanotube have better SERS enhancement than surface cap. • Ag NPs reconstruction via self-migration with UV and humidity control. • Self-cleaning effects both on organic molecule photo-oxidation as well as Ag ions photo-reduction. - Abstract: A simple strategy for synthesizing Ag-loaded TiO{sub 2} nanotube film for use as multifunctional photocatalyst and recyclable surface-enhanced Raman scattering (SERS) substrate is introduced. Highly aligned TiO{sub 2} nanotube arrays (TNTA) prepared via electrochemical anodization were used as a 3D rough host for silver nanoparticles. Ag deposits were sputtered in a vacuum, and it was found that their morphologies were mainly influenced by the diameters of nanotubes and the UV irradiation induced aging process, especially the self-migration of silver along the tubular wall. SERS and the self-cleaning effect were observed using Rhodamine 6G (R6G) as the probe molecule. The results showed that narrow nanotube and silver nanoparticles embedment contributed significantly to both the phenomenal SERS and recyclability.

  10. 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.

  11. 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.

  12. Nanostructured surfaces for analysis of anticancer drug and cell diagnosis based on electrochemical and SERS tools

    Science.gov (United States)

    El-Said, Waleed A.; Yoon, Jinho; Choi, Jeong-Woo

    2018-04-01

    Discovering new anticancer drugs and screening their efficacy requires a huge amount of resources and time-consuming processes. The development of fast, sensitive, and nondestructive methods for the in vitro and in vivo detection of anticancer drugs' effects and action mechanisms have been done to reduce the time and resources required to discover new anticancer drugs. For the in vitro and in vivo detection of the efficiency, distribution, and action mechanism of anticancer drugs, the applications of electrochemical techniques such as electrochemical cell chips and optical techniques such as surface-enhanced Raman spectroscopy (SERS) have been developed based on the nanostructured surface. Research focused on electrochemical cell chips and the SERS technique have been reviewed here; electrochemical cell chips based on nanostructured surfaces have been developed for the in vitro detection of cell viability and the evaluation of the effects of anticancer drugs, which showed the high capability to evaluate the cytotoxic effects of several chemicals at low concentrations. SERS technique based on the nanostructured surface have been used as label-free, simple, and nondestructive techniques for the in vitro and in vivo monitoring of the distribution, mechanism, and metabolism of different anticancer drugs at the cellular level. The use of electrochemical cell chips and the SERS technique based on the nanostructured surface should be good tools to detect the effects and action mechanisms of anticancer drugs.

  13. In situ SERS detection of emulsifiers at lipid interfaces using label-free amphiphilic gold nanoparticles.

    Science.gov (United States)

    Li, Yue; Driver, Michael; Winuprasith, Thunnalin; Zheng, Jinkai; McClements, David Julian; He, Lili

    2014-10-21

    Herein, we fabricated amphiphilic gold nanoparticles (GNPs) that can self-assemble at oil-water interfaces. We applied those GNPs for in situ SERS detection of emulsifier molecules within the interfacial region of oil in water (O/W) emulsion systems.

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

    Energy Technology Data Exchange (ETDEWEB)

    Manno, D; Filippo, E; Fiore, R; Serra, A [Dipartimento di Scienza dei Materiali, Universita del Salento, Lecce (Italy); Urso, E; Rizzello, A; Maffia, M [Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Universita del Salento, Lecce (Italy)

    2010-04-23

    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{sup 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{sup 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.

  15. Circles within circles: crosstalk between protein Ser/Thr/Tyr-phosphorylation and Met oxidation

    Science.gov (United States)

    Background: Reversible posttranslational protein modifications such as phosphorylation of Ser/Thr/Tyr and Met oxidation are critical for both metabolic regulation and cellular signalling. Although these modifications are typically studied individually, herein we describe the potential for cross-talk...

  16. SERS-active ZnO/Ag hybrid WGM microcavity for ultrasensitive dopamine detection

    Science.gov (United States)

    Lu, Junfeng; Xu, Chunxiang; Nan, Haiyan; Zhu, Qiuxiang; Qin, Feifei; Manohari, A. Gowri; Wei, Ming; Zhu, Zhu; Shi, Zengliang; Ni, Zhenhua

    2016-08-01

    Dopamine (DA) is a potential neuro modulator in the brain which influences a variety of motivated behaviors and plays a key role in life science. A hybrid ZnO/Ag microcavity based on Whispering Gallery Mode (WGM) effect has been developed for ultrasensitive detection of dopamine. Utilizing this effect of structural cavity mode, a Raman signal of R6G (5 × 10-3 M) detected by this designed surface-enhanced Raman spectroscopy (SERS)-active substrate was enhanced more than 10-fold compared with that of ZnO film/Ag substrate. Also, this hybrid microcavity substrate manifests high SERS sensitivity to rhodamine 6 G and detection limit as low as 10-12 M to DA. The Localized Surface Plasmons of Ag nanoparticles and WGM-enhanced light-matter interaction mainly contribute to the high SERS sensitivity and help to achieve a lower detection limit. This designed SERS-active substrate based on the WGM effect has the potential for detecting neurotransmitters in life science.

  17. Using a silver-enhanced microarray sandwich structure to improve SERS sensitivity for protein detection.

    Science.gov (United States)

    Gu, Xuefang; Yan, Yuerong; Jiang, Guoqing; Adkins, Jason; Shi, Jian; Jiang, Guomin; Tian, Shu

    2014-03-01

    A simple and sensitive method, based on surface-enhanced Raman scattering (SERS), for immunoassay and label-free protein detection is reported. A series of bowl-shaped silver cavity arrays were fabricated by electrodeposition using a self-assembled polystyrene spheres template. The reflection spectra of these cavity arrays were recorded as a function of film thickness, and then correlated with SERS enhancement using sodium thiophenolate as the probe molecule. The results reveal that SERS enhancement can be maximized when the frequency of both the incident laser and the Raman scattering approach the frequency of the localized surface plasmon resonance. The optimized array was then used as the bottom layer of a silver nanoparticle-protein-bowl-shaped silver cavity array sandwich. The second layer of silver was introduced by the interactions between the proteins in the middle layer of the sandwich architecture and silver nanoparticles. Human IgG bound to the surface of this microcavity array can retain its recognition function. With the Raman reporter molecules labeled on the antibody, a detection limit down to 0.1 ng mL(-1) for human IgG is easily achieved. Furthermore, the SERS spectra of label-free proteins (catalase, cytochrome C, avidin and lysozyme) from the assembled sandwich have excellent reproducibility and high quality. The results reveal that the proposed approach has potential for use in qualitative and quantitative detection of biomolecules.

  18. 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

  19. 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.

  20. Planar SERS nanostructures with stochastic silver ring morphology for biosensor chips

    DEFF Research Database (Denmark)

    Semenova, Anna; Goodilin, Eugene; Brazhe, Nadezda

    2012-01-01

    Surface-enhanced Raman spectroscopy (SERS) of living cells has rapidly become a powerful trend in biomedical diagnostics. It is a common belief that highly ordered, artificially engineered substrates are the best future decision in this field. This paper, however, describes an alternative...

  1. The Ser311Cys variation in the paraoxonase 2 gene increases the ...

    Indian Academy of Sciences (India)

    Supplementary data: The Ser311Cys variation in the paraoxonase 2 gene increases the risk of type 2 diabetes in northern Chinese. Yanchun Qu, Ze Yang, Feng Jin, Liang Sun, Chuanfang Zhang, Linong Ji, Hong Sun, Binyou Wang and Li Wang. J. Genet. 87, 165–169. Table 1. Clinical characteristics of case and control.

  2. Organelle-targeting surface-enhanced Raman scattering (SERS) nanosensors for subcellular pH sensing.

    Science.gov (United States)

    Shen, Yanting; Liang, Lijia; Zhang, Shuqin; Huang, Dianshuai; Zhang, Jing; Xu, Shuping; Liang, Chongyang; Xu, Weiqing

    2018-01-25

    The pH value of subcellular organelles in living cells is a significant parameter in the physiological activities of cells. Its abnormal fluctuations are commonly believed to be associated with cancers and other diseases. Herein, a series of surface-enhanced Raman scattering (SERS) nanosensors with high sensitivity and targeting function was prepared for the quantification and monitoring of pH values in mitochondria, nucleus, and lysosome. The nanosensors were composed of gold nanorods (AuNRs) functionalized with a pH-responsive molecule (4-mercaptopyridine, MPy) and peptides that could specifically deliver the AuNRs to the targeting subcellular organelles. The localization of our prepared nanoprobes in specific organelles was confirmed by super-high resolution fluorescence imaging and bio-transmission electron microscopy (TEM) methods. By the targeting ability, the pH values of the specific organelles can be determined by monitoring the vibrational spectral changes of MPy with different pH values. Compared to the cases of reported lysosome and cytoplasm SERS pH sensors, more accurate pH values of mitochondria and nucleus, which could be two additional intracellular tracers for subcellular microenvironments, were disclosed by this SERS approach, further improving the accuracy of discrimination of related diseases. Our sensitive SERS strategy can also be employed to explore crucial physiological and biological processes that are related to subcellular pH fluctuations.

  3. Sodium Chloride Crystal-Induced SERS Platform for Controlled Highly Sensitive Detection of Illicit Drugs.

    Science.gov (United States)

    Yu, Borong; Li, Pan; Zhou, Binbin; Tang, Xianghu; Li, Shaofei; Yang, Liangbao

    2018-04-03

    A sodium chloride crystal-driven spontaneous 'hot spot' structure was demonstrated as a SERS-active platform, to get reproducible SERS signals, and eliminate the need for mapping large areas, in comparison with solution phase testing. During the process of solvent evaporation, the crystals produced induced silver aggregates to assemble around themselves. The micro-scale crystals can also act as a template to obtain an optical position, such that the assembled hot area is conveniently located during SERS measurements. More importantly, the chloride ions added in colloids can also replace the citrate and on the surface of the silver sol, and further decrease the background interference. High quality SERS spectra from heroin, methamphetamine (MAMP), and cocaine have been obtained on the crystal-driven hot spot structure with high sensitivity and credible reproducibility. This approach can not only bring the nanoparticles to form plasmonic hot spots in a controlled way, and thus provide high sensitivity, but also potentially be explored as an active substrate for label-free detection of other illicit drugs or additives. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. [TLC-FT-SERS study on a pair of optic isomers in ephedra].

    Science.gov (United States)

    Wang, Yuan; Zhang, Jin-zhi; Ma, Xin-yong

    2004-11-01

    A new method for analyzing the ingredients of a pair of optic isomers in ephedra, nor-ephedrine and nor-pseudo-ephedrine, using hyphenated high-efficiency thin layer chromatography (TLC) and surface-enhanced Raman spectroscopy (SERS) techniques, is reported. The results show that the characteristic spectral bands of nor-ephedrine and nor-pseudo-ephedrine can be obtained from the TLC spot with 8 microg sample of about 2.0 mm in diameter. The difference between the SERS and solid spectra was found. Spectral bands at 1004 cm(-1) and 1605 cm(-1) were found greatly enhanced. Molecule was absorbed in surface silver sol by pi electrons in ring. Under similar experimental conditions the spectral information of Levo-nor-ephedrine ramifications TLC-SERS is rich with strong credibility, whereas dextral-nor-ephedrine ramifications show a relatively strong fluorescence backdrop with less spectral information and weak credibility. The effective combination of TLC and SERS can be used to analyse the chemical ingredients with high sensitivity.

  5. 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

  6. Efectividad del láser de baja intensidad en el control de la hipersensibilidad dentrinaria

    OpenAIRE

    Gomez, Nadia; Garcia, Karen; Herrera, Helen de; Herrera, Henry

    2008-01-01

    La hipersensibilidad dentinaria se define "un dolor breve y agudo que se origina en la dentina expuesta como respuesta a los estímulos típicos como los térmicos, evaporativos, táctiles, osmóticos o químicos que no pueden ser atribuidos a otra patología dental

  7. 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...

  8. 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.

  9. 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.

  10. SERS and DFT study of p-hydroxybenzoic acid adsorbed on colloidal silver particles.

    Science.gov (United States)

    Chen, Y; Chen, S J; Li, S; Wei, J J

    2015-10-16

    In this study, normal Raman spectra of p—hydroxybenzoic acid (PHBA) powder and its surface—enhanced Raman scattering (SERS) spectra in silver colloidal solutions were measured under near infrared excitation conditions. In theoretical calculation, two models of PHBA adsorbed on the surfaces of silver nanoparticles were established. The Raman frequencies of these two models using density functional theory (DFT) method were calculated, and compared with the experimental results. It was found that the calculated Raman frequencies were in good agreement with experimental values, which indicates that there are two enhanced mechanism physical (electromagnetic, EM) enhancement and chemical (charge—transfer, CT) enhancement, in silver colloidal solutions regarding SERS effect. Furthermore, from high—quality SERS spectrum of PHBA obtained in silver colloids, we inferred that PHBA molecules in silver colloids adsorb onto the metal surfaces through carboxyl at a perpendicular orientation. The combination of SERS spectra and DFT calculation is thus useful for studies of the adsorption—orientation of a molecule on a metal colloid.

  11. Thin silica shell coated Ag assembled nanostructures for expanding generality of SERS analytes.

    Directory of Open Access Journals (Sweden)

    Myeong Geun Cha

    Full Text Available Surface-enhanced Raman scattering (SERS provides a unique non-destructive spectroscopic fingerprint for chemical detection. However, intrinsic differences in affinity of analyte molecules to metal surface hinder SERS as a universal quantitative detection tool for various analyte molecules simultaneously. This must be overcome while keeping close proximity of analyte molecules to the metal surface. Moreover, assembled metal nanoparticles (NPs structures might be beneficial for sensitive and reliable detection of chemicals than single NP structures. For this purpose, here we introduce thin silica-coated and assembled Ag NPs (SiO2@Ag@SiO2 NPs for simultaneous and quantitative detection of chemicals that have different intrinsic affinities to silver metal. These SiO2@Ag@SiO2 NPs could detect each SERS peak of aniline or 4-aminothiophenol (4-ATP from the mixture with limits of detection (LOD of 93 ppm and 54 ppb, respectively. E-field distribution based on interparticle distance was simulated using discrete dipole approximation (DDA calculation to gain insight into enhanced scattering of these thin silica coated Ag NP assemblies. These NPs were successfully applied to detect aniline in river water and tap water. Results suggest that SiO2@Ag@SiO2 NP-based SERS detection systems can be used as a simple and universal detection tool for environment pollutants and food safety.

  12. Progress in the Development of SERS-Active Substrates Based on Metal-Coated Porous Silicon.

    Science.gov (United States)

    Bandarenka, Hanna V; Girel, Kseniya V; Zavatski, Sergey A; Panarin, Andrei; Terekhov, Sergei N

    2018-05-21

    The present work gives an overview of the developments in surface-enhanced Raman scattering (SERS) with metal-coated porous silicon used as an active substrate. We focused this review on the research referenced to SERS-active materials based on porous silicon, beginning from the patent application in 2002 and enclosing the studies of this year. Porous silicon and metal deposition technologies are discussed. Since the earliest studies, a number of fundamentally different plasmonic nanostructures including metallic dendrites, quasi-ordered arrays of metallic nanoparticles (NPs), and metallic nanovoids have been grown on porous silicon, defined by the morphology of this host material. SERS-active substrates based on porous silicon have been found to combine a high and well-reproducible signal level, storage stability, cost-effective technology and handy use. They make it possible to identify and study many compounds including biomolecules with a detection limit varying from milli- to femtomolar concentrations. The progress reviewed here demonstrates the great prospects for the extensive use of the metal-coated porous silicon for bioanalysis by SERS-spectroscopy.

  13. Progress in the Development of SERS-Active Substrates Based on Metal-Coated Porous Silicon

    Directory of Open Access Journals (Sweden)

    Hanna V. Bandarenka

    2018-05-01

    Full Text Available The present work gives an overview of the developments in surface-enhanced Raman scattering (SERS with metal-coated porous silicon used as an active substrate. We focused this review on the research referenced to SERS-active materials based on porous silicon, beginning from the patent application in 2002 and enclosing the studies of this year. Porous silicon and metal deposition technologies are discussed. Since the earliest studies, a number of fundamentally different plasmonic nanostructures including metallic dendrites, quasi-ordered arrays of metallic nanoparticles (NPs, and metallic nanovoids have been grown on porous silicon, defined by the morphology of this host material. SERS-active substrates based on porous silicon have been found to combine a high and well-reproducible signal level, storage stability, cost-effective technology and handy use. They make it possible to identify and study many compounds including biomolecules with a detection limit varying from milli- to femtomolar concentrations. The progress reviewed here demonstrates the great prospects for the extensive use of the metal-coated porous silicon for bioanalysis by SERS-spectroscopy.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. [AgBr colloids prepared by electrolysis and their SERS activity research].

    Science.gov (United States)

    Si, Min-Zhen; Fang, Yan; Dong, Gang; Zhang, Peng-Xiang

    2008-01-01

    Ivory-white AgBr colloids were prepared by means of electrolysis. Two silver rods 1.0 cm in diameter and 10.0 cm long were respectively used as the negative and positive electrodes, the aqueous solution of hexadecyl trimethyl ammonium bromide was used as the electrolyte, and a 7 V direct current was applied on the silver rods for three hours. The obtained AgBr colloids were characterized by UV-Vis spectroscopy, transmission electron microscopy, and SERS using a 514. 5 nm laser line on Renishaw 2000 Raman spectrometer. These particles are about nanometer size and their shapes are as spherical or elliptic, with a slight degree of particle aggregation. The UV-Vis spectra exhibit a large plasmon resonance band at about 292.5 nm, similar to that reported in the literature. The AgBr colloids were very stable at room temperature for months. In order to test if these AgBr colloids can be used for SERS research, methyl orange, Sudan red and pyridine were used. It was found that AgBr colloids have SERS activity to these three molicules. For methyl orange, the intense Raman peaks are at 1 123, 1 146, 1 392, 1 448 and 1 594 cm(-1); for Sudan red, the intense Raman peaks are at 1 141, 1 179, 1 433 and 1 590 cm(-1); and for pyridine, the intense Raman peaks are at 1 003, 1 034 and 1 121 cm(-1). It is noticeable that SERS of methyl orange was observed on AgBr colloids, but not on the gray and yellow silver colloids prepared by traditional means. The possible reason was explained. One major advantage of this means is the absence of the spectral interference such as citrate, BH4- arising from reaction products of the colloids formation process. On AgBr colloids, one can get some molecular SERS impossible to get on the gray and yellow silver colloids.

  20. 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.

  1. Why Ser and not Thr brokers catalysis in the trypsin fold.

    Science.gov (United States)

    Pelc, Leslie A; Chen, Zhiwei; Gohara, David W; Vogt, Austin D; Pozzi, Nicola; Di Cera, Enrico

    2015-02-24

    Although Thr is equally represented as Ser in the human genome and as a nucleophile is as good as Ser, it is never found in the active site of the large family of trypsin-like proteases that utilize the Asp/His/Ser triad. The molecular basis of the preference of Ser over Thr in the trypsin fold was investigated with X-ray structures of the thrombin mutant S195T free and bound to an irreversible active site inhibitor. In the free form, the methyl group of T195 is oriented toward the incoming substrate in a conformation seemingly incompatible with productive binding. In the bound form, the side chain of T195 is reoriented for efficient substrate acylation without causing steric clash within the active site. Rapid kinetics prove that this change is due to selection of an active conformation from a preexisting ensemble of reactive and unreactive rotamers whose relative distribution determines the level of activity of the protease. Consistent with these observations, the S195T substitution is associated with a weak yet finite activity that allows identification of an unanticipated important role for S195 as the end point of allosteric transduction in the trypsin fold. The S195T mutation abrogates the Na(+)-dependent enhancement of catalytic activity in thrombin, activated protein C, and factor Xa and significantly weakens the physiologically important allosteric effects of thrombomodulin on thrombin and of cofactor Va on factor Xa. The evolutionary selection of Ser over Thr in trypsin-like proteases was therefore driven by the need for high catalytic activity and efficient allosteric regulation.

  2. 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

  3. Si pudiese volver no cambiaría ese día: el relato de una joven tras sufrir un accidente de tráfico

    Directory of Open Access Journals (Sweden)

    Celia Martí García

    Full Text Available Los accidentes de tráfico son causa de un porcentaje bastante elevado de muertes en los países occidentalizados. Si hablamos de accidentes de moto, los factores de riesgo para que la persona sufra daños mayores se ven multiplicados, sobre todo si tenemos en cuenta lo desprotegida que va la víctima y las velocidades a las que se suelen producir este tipo de accidentes. La informante de este relato nos contará la vivencia que supuso para ella sufrir un accidente en motocicleta cuando tenía 15 años, las intervenciones quirúrgicas a las que tuvo que someterse, y su reincorporación académica. En definitiva, cómo le ha influido en su vida y qué secuelas le ha dejado su exceso de velocidad.

  4. 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.

  5. 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.

  6. 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.

  7. A FILOSOFIA DOS JOVENS SOBRE O SER JOVEM: UMA PESQUISA SOCIOPOÉTICA

    OpenAIRE

    Carneiro, Cristianne Teixeira; Universidade Federal do Piauí - UFPI; Bezerra, Maria Augusta Rocha; Universidade Federal do Piauí - UFPI; Adad, Shara Jane Holanda Costa; Universidade Federal do Piauí - UFPI; Santos, Kathia Raquel Piauilino; Universidade Federal do Piauí - UFPI; Carvalho, Francimeiry Santos; Universidade Federal do Piauí - UFPI

    2015-01-01

    Objetivou-se conhecer os modos de pensar dos jovens de um curso técnico em enfermagem de um colégio técnico federal sobre “o que é ser jovem?”. A pesquisa se insere no paradigma qualitativo de investigação utilizando a Sociopoética, foi realizada com 11 jovens que cursavam o ensino médio concomitante ao técnico em enfermagem em 2013. Os jovens problematizaram a dimensão do tempo de espera para o mundo adulto, mostrando que não há um único modo de ser jovem e nem de se tornar adulto, pois para...

  8. Optical Characterization of SERS Substrates Based on Porous Au Films Prepared by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    V. V. Strelchuk

    2015-01-01

    Full Text Available The SERS (surface enhanced Raman spectroscopy substrates based on nanocomposite porous films with gold nanoparticles (Au NPs arrays were formed using the method of the pulsed laser deposition from the back low-energy flux of erosion torch particles on the glass substrate fixed at the target plain. The dependencies of porosity, and morphology of the surface of the film regions located near and far from the torch axis on the laser ablation regime, laser pulses energy density, their number, and argon pressure in the vacuum chamber, were ascertained. The Au NPs arrays with the controllable extinction spectra caused by the local surface plasmon resonance were prepared. The possibility of the formation of SERS substrates for the detection of the Rhodamine 6G molecules with the concentration 10−10 Mol/L with the enhancement factor 4·107 was shown.

  9. 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.

  10. 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.

  11. 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

  12. 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...

  13. Linear Optical and SERS Study on Metallic Membranes with Subwavelength Complementary Patterns

    Science.gov (United States)

    Hao, Qingzhen; Zeng, Yong; Jensen, Lasse; Werner, Douglas; Crespi, Vincent; Huang, Tony Jun; Interdepartmental Collaboration

    2011-03-01

    An efficient technique is developed to fabricate optically thin metallic films with subwavelength patterns and their complements simultaneously. By comparing the spectra of the complementary films, we show that Babinet's principle nearly holds in the optical domain. A discrete-dipole approximation can qualitatively describe their spectral dependence on the geometry of the constituent particles and the illuminating polarization. Using pyridine as probe molecules, we studied surface-enhanced Raman spectroscopy (SERS) from the complementary structure. Although the complementary structure posses closely related linear spectra, they have quite different near-field behaviors. For hole arrays, their averaged local field gains as well as the SERS enhancements are strongly correlated to their transmission spectra. We therefore can use cos 4 θ to approximately describe the dependence of the Raman intensity on the excitation polarization angle θ , while the complementary particle arrays present maximal local field gains at wavelengths generally much bigger than their localized surface plasmonic resonant wavelengths.

  14. Surface modified gold nanoparticles for SERS based detection of vulnerable plaque formations (Conference Presentation)

    Science.gov (United States)

    Matthäus, Christian; Dugandžić, Vera; Weber, Karina; Cialla-May, Dana; Popp, Jürgen

    2017-02-01

    Cardiovascular diseases are the leading cause of death worldwide. Atherosclerosis is closely related to the majority of these diseases, as a process of thickening and stiffening of the arterial walls through accumulation of lipids, which is a consequence of aging and life style. Atherosclerosis affects all people in some extent, but not all arterial plaques will necessarily lead to the complications, such as thrombosis, stroke and heart attack. One of the greatest challenges in the risk assessment of atherosclerotic depositions is the detection and recognition of plaques which are unstable and prone to rupture. These vulnerable plaques usually consist of a lipid core that attracts macrophages, a type of white blood cells that are responsible for the degradation of lipids. It has been hypothesized that the amount of macrophages relates to the overall plaque stability. As phagocytes, macrophages also act as recipients for nanoscale particles or structures. Administered gold nanoparticles are usually rabidly taken up by macrophages residing within arterial walls and can therefore be indirectly detected. A very sensitive strategy for probing gold nanoparticles is by utilizing surface enhanced Raman scattering (SERS). By modifying the surface of these particles with SERS active labels it is possible to generate highly specific signals that exhibit sensitivity comparable to fluorescence. SERS labeled gold nanoparticles have been synthesized and the uptake dynamics and efficiency on macrophages in cell cultures was investigated using Raman microscopic imaging. The results clearly show that nanoparticles are taken up by macrophages and support the potential of SERS spectroscopy for the detection of vulnerable plaques. Acknowledgements: Financial support from the Carl Zeiss Foundation is highly acknowledged. The project "Jenaer Biochip Initiative 2.0" (03IPT513Y) within the framework "InnoProfile Transfer - Unternehmen Region" is supported by the Federal Ministry of

  15. 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

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

    Science.gov (United States)

    2017-12-04

    environmental contamination concerns. For SERS to function as an accurate, reliable, and reproducible technology for all of these research areas, it is... manufactured , demonstrate signal reproducibility from substrate to substrate and lot to lot, and are capable of being used in a host of environments...support staff must have safe food , air, water, and a secure environment. To ensure this safety it is important to not only detect, but also to

  17. 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.

  18. 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

  19. Accurate SERS detection of malachite green in aquatic products on basis of graphene wrapped flexible sensor.

    Science.gov (United States)

    Ouyang, Lei; Yao, Ling; Zhou, Taohong; Zhu, Lihua

    2018-10-16

    Malachite Green (MG) is a banned pesticide for aquaculture products. As a required inspection item, its fast and accurate determination before the products' accessing market is very important. Surface enhanced Raman scattering (SERS) is a promising tool for MG sensing, but it requires the overcoming of several problems such as fairly poor sensitivity and reproducibility, especially laser induced chemical conversion and photo-bleaching during SERS observation. By using a graphene wrapped Ag array based flexible membrane sensor, a modified SERS strategy was proposed for the sensitive and accurate detection of MG. The graphene layer functioned as an inert protector for impeding chemical transferring of the bioproduct Leucomalachite Green (LMG) to MG during the SERS detection, and as a heat transmitter for preventing laser induced photo-bleaching, which enables the separate detection of MG and LMG in fish extracts. The combination of the Ag array and the graphene cover also produced plentiful densely and uniformly distributed hot spots, leading to analytical enhancement factor up to 3.9 × 10 8 and excellent reproducibility (relative standard deviation low to 5.8% for 70 runs). The proposed method was easily used for MG detection with limit of detection (LOD) as low as 2.7 × 10 -11  mol L -1 . The flexibility of the sensor enable it have a merit for in-field fast detection of MG residues on the scale of a living fish through a surface extraction and paste transferring manner. The developed strategy was successfully applied in the analysis of real samples, showing good prospects for both the fast inspection and quantitative detection of MG. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. 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. Keywords: Surface-Enhanced Raman Spectroscopy, Hydrogen cyanide, Pseudomonas aeruginosa, Cystic fibrosis, Breath analysis

  1. Study of recombinant proteins derived from Ser-2 gene of Bombyx mori

    OpenAIRE

    STAŠKOVÁ, Tereza

    2012-01-01

    Four different variants of recombinant proteins derived from Bombyx mori Ser-2 gene were expressed in bacteria. The ability of these proteins to coat hydrofobic surfaces and to support growth of various types of adherent cells in vitro were examined. It was shown that these proteins support cell adhesion and proliferation, and could be used as coating agents to realize surfaces suitable for growth of vertebrate and insect cells.

  2. Next-generation Surface Enhanced Raman Scattering (SERS) Substrates for Hazard Detection

    Science.gov (United States)

    2012-09-01

    substrates at differing concentrations ranging from 0.05 ug/cm2 to 50 ug/cm2. These concentrations were independently validated by UV -Vis...standard Klarite substrates at a concentration of 5.0 ug/cm2. The concentration jetted was validated using a secondary UV -Vis technique.(20, 81) After... Spectros ., 994 (1997). [58] Alexander, T.A., Le, D.M., "Characterization of a commercialized SERS-active substrate and its application to the

  3. Control d'un làser mitjançant Arduino

    OpenAIRE

    Bernal Muñoz, Ferran

    2015-01-01

    ARDUINO is a vey usefull platform for prototypes. In this project ARDUINO will be used for controling a Semiconductor Tuneable Laser. [ANGLÈS] Diode laser for communications control based on an Arduino board. Temperature control implementation. Software and hardware protection for the laser implementation. [CASTELLÀ] Control de un láser de comunicaciones ópticas desde el ordenador utilizando una placa Arduino. Implementación de un control de temperatura y protección software y hardware ...

  4. SERS detection of pneumonia in breath of children with cystic fibrosis

    DEFF Research Database (Denmark)

    Lauridsen, Rikke Kragh; Molin, Søren

    Cystic fibrosis (CF) is the most frequently inherited disease in the Western world, and also the one with the highest morbidity and mortality. The main reason is chronic lung infections caused by the pathogenic bacterium Pseudomonas aeruginosa, which is well-adapted to the thick and dehydrated mu...... exposed to passive smoking at home. The SERS substrate has a background peak in the Raman spectrum, which needs to be addressed, because it is located very close to the cyanide peak....

  5. The Staphylococcus aureus autoinducer-2 synthase LuxS is regulated by Ser/Thr phosphorylation.

    Science.gov (United States)

    Cluzel, Marie-Eve; Zanella-Cléon, Isabelle; Cozzone, Alain J; Fütterer, Klaus; Duclos, Bertrand; Molle, Virginie

    2010-12-01

    The Staphylococcus aureus autoinducer-2 (AI-2) producer protein LuxS is phosphorylated by the Ser/Thr kinase Stk1 at a unique position, Thr14. The enzymatic activity of the phosphorylated isoform of LuxS was abrogated compared to that of nonphosphorylated LuxS, thus providing the first evidence of an AI-2-producing enzyme regulated by phosphorylation and demonstrating that S. aureus possesses an original and specific system for controlling AI-2 synthesis.

  6. The Staphylococcus aureus Autoinducer-2 Synthase LuxS Is Regulated by Ser/Thr Phosphorylation▿

    Science.gov (United States)

    Cluzel, Marie-Eve; Zanella-Cléon, Isabelle; Cozzone, Alain J.; Fütterer, Klaus; Duclos, Bertrand; Molle, Virginie

    2010-01-01

    The Staphylococcus aureus autoinducer-2 (AI-2) producer protein LuxS is phosphorylated by the Ser/Thr kinase Stk1 at a unique position, Thr14. The enzymatic activity of the phosphorylated isoform of LuxS was abrogated compared to that of nonphosphorylated LuxS, thus providing the first evidence of an AI-2-producing enzyme regulated by phosphorylation and demonstrating that S. aureus possesses an original and specific system for controlling AI-2 synthesis. PMID:20870760

  7. 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.

  8. Disulphide linkage: To get cleaved or not? Bulk and nano copper based SERS of cystine

    Science.gov (United States)

    P. J., Arathi; Seemesh, Bhaskar; Rajendra Kumar Reddy, G.; Suresh Kumar, P.; Ramanathan, V.

    2018-05-01

    Different nano-structures of noble metals have been the conventional substrates for carrying out Surface Enhanced Raman Spectroscopy (SERS). In this paper we examine electrodeposited copper (Cu) nano-structures on pencil graphite as novel substrate to carry out SERS measurements by considering L-cystine (Cys-Cys) (dimer of the amino acid cysteine) as the probe. The formation of monolayer of the probe molecule on the substrates was confirmed using cyclic voltammetric measurements. Mode of adsorption of Cys-Cys was observed to be different on bulk Cu (taken in the wire form) and nano-structured Cu on pencil graphite. Whereas in the former the disulphide bond of Cys-Cys remained intact, it got cleaved when Cys-Cys was adsorbed on electrodeposited copper indicating the activated nature of the nano-structure compared to bulk copper. Csbnd S stretching mode of vibration underwent blue shift in Cys-Cys adsorbed on Cu on pencil graphite vis-à-vis Cys-Cys adsorbed on Cu wire. Further evidence on the cleavage of the Csbnd S bond on an activated substrate was obtained by considering a bimetallic substrate comprising of silver on copper which was electrodeposited on pencil graphite. Our studies have demonstrated that nano-copper surface is an excellent substrate for SERS giving 200 μM as lower detection limit for Cys-Cys.

  9. 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.

  10. 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.

  11. Method for assessing the reliability of molecular diagnostics based on multiplexed SERS-coded nanoparticles.

    Directory of Open Access Journals (Sweden)

    Steven Y Leigh

    Full Text Available Surface-enhanced Raman scattering (SERS nanoparticles have been engineered to generate unique fingerprint spectra and are potentially useful as bright contrast agents for molecular diagnostics. One promising strategy for biomedical diagnostics and imaging is to functionalize various particle types ("flavors", each emitting a unique spectral signature, to target a large multiplexed panel of molecular biomarkers. While SERS particles emit narrow spectral features that allow them to be easily separable under ideal conditions, the presence of competing noise sources and background signals such as detector noise, laser background, and autofluorescence confounds the reliability of demultiplexing algorithms. Results obtained during time-constrained in vivo imaging experiments may not be reproducible or accurate. Therefore, our goal is to provide experimentalists with a metric that may be monitored to enforce a desired bound on accuracy within a user-defined confidence level. We have defined a spectral reliability index (SRI, based on the output of a direct classical least-squares (DCLS demultiplexing routine, which provides a measure of the reliability of the computed nanoparticle concentrations and ratios. We present simulations and experiments to demonstrate the feasibility of this strategy, which can potentially be utilized for a range of instruments and biomedical applications involving multiplexed SERS nanoparticles.

  12. 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.

  13. 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.

  14. 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.

  15. Ser derivation and power optimization of a two-way multirelay cooperative communication system

    International Nuclear Information System (INIS)

    Rehman, S.U.; Shah, S.I.; Fareed, M.M.

    2014-01-01

    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. (author)

  16. 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.

  17. 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)

  18. SERS detection of the biomarker hydrogen cyanide from Pseudomonas aeruginosa cultures isolated from cystic fibrosis patients

    Science.gov (United States)

    Lauridsen, Rikke Kragh; Sommer, Lea M.; Johansen, Helle Krogh; Rindzevicius, Tomas; Molin, Søren; Jelsbak, Lars; Engelsen, Søren Balling; Boisen, Anja

    2017-03-01

    Pseudomonas aeruginosa is the primary cause of chronic airway infections in cystic fibrosis (CF) patients. Persistent infections are seen from the first P. aeruginosa culture in about 75% of young CF patients, and it is important to discover new ways to detect P. aeruginosa at an earlier stage. The P. aeruginosa biomarker hydrogen cyanide (HCN) contains a triple bond, which is utilized in this study because of the resulting characteristic C≡N peak at 2135 cm-1 in a Raman spectrum. The Raman signal was enhanced by surface-enhanced Raman spectroscopy (SERS) on a Au-coated SERS substrate. After long-term infection, a mutation in the patho-adaptive lasR gene can alter the expression of HCN, which is why it is sometimes not possible to detect HCN in the breath of chronically infected patients. Four P. aeruginosa reference strains and 12 clinical P. aeruginosa strains isolated from CF children were evaluated, and HCN was clearly detected from overnight cultures of all wild type-like isolates and half of the later isolates from the same patients. The clinical impact could be that P. aeruginosa infections could be detected at an earlier stage, because daily breath sampling with an immediate output could be possible with a point-of-care SERS device.

  19. Two-step fabrication of nanoporous copper films with tunable morphology for SERS application

    Science.gov (United States)

    Diao, Fangyuan; Xiao, Xinxin; Luo, Bing; Sun, Hui; Ding, Fei; Ci, Lijie; Si, Pengchao

    2018-01-01

    It is important to design and fabricate nanoporous metals (NPMs) with optimized microstructures for specific applications. In this contribution, nanoporous coppers (NPCs) with controllable thicknesses and pore sizes were fabricated via the combination of a co-sputtering of Cu/Ti with a subsequent dealloying process. The effect of dealloying time on porous morphology and the corresponding surface enhanced Raman scattering (SERS) behaviors were systematically investigated. Transmission electron microscopy (TEM) identified the presences of the gaps formed between ligaments and also the nanobumps on the nanoparticle-aggregated ligament surface, which were likely to contribute as the ;hot spots; for electromagnetic enhancement. The optimal NPC film exhibited excellent SERS performance towards Rhodamine 6G (R6G) with a low limiting detection (10-9 M), along with good uniformity and reproducibility. The calculated enhancement factor of ca. 4.71 × 107 was over Au substrates and comparable to Ag systems, promising the proposed NPC as a cheap candidate for high-performance SERS substrate.

  20. 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.

  1. SERS-barcoded colloidal gold NP assemblies as imaging agents for use in biodiagnostics

    Science.gov (United States)

    Dey, Priyanka; Olds, William; Blakey, Idriss; Thurecht, Kristofer J.; Izake, Emad L.; Fredericks, Peter M.

    2014-03-01

    There is a growing need for new biodiagnostics that combine high throughput with enhanced spatial resolution and sensitivity. Gold nanoparticle (NP) assemblies with sub-10 nm particle spacing have the benefits of improving detection sensitivity via Surface enhanced Raman scattering (SERS) and being of potential use in biomedicine due to their colloidal stability. A promising and versatile approach to form solution-stable NP assemblies involves the use of multi-branched molecular linkers which allows tailoring of the assembly size, hot-spot density and interparticle distance. We have shown that linkers with multiple anchoring end-groups can be successfully employed as a linker to assemble gold NPs into dimers, linear NP chains and clustered NP assemblies. These NP assemblies with diameters of 30-120 nm are stable in solution and perform better as SERS substrates compared with single gold NPs, due to an increased hot-spot density. Thus, tailored gold NP assemblies are potential candidates for use as biomedical imaging agents. We observed that the hot-spot density and in-turn the SERS enhancement is a function of the linker polymer concentration and polymer architecture. New deep Raman techniques like Spatially Offset Raman Spectroscopy (SORS) have emerged that allow detection from beneath diffusely scattering opaque materials, including biological media such as animal tissue. We have been able to demonstrate that the gold NP assemblies could be detected from within both proteinaceous and high lipid containing animal tissue by employing a SORS technique with a backscattered geometry.

  2. 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.

  3. Sensitive SERS-pH sensing in biological media using metal carbonyl functionalized planar substrates.

    Science.gov (United States)

    Kong, Kien Voon; Dinish, U S; Lau, Weber Kam On; Olivo, Malini

    2014-04-15

    Conventional nanoparticle based Surface enhanced Raman scattering (SERS) technique for pH sensing often fails due to the aggregation of particles when detecting in acidic medium or biosamples having high ionic strength. Here, We develop SERS based pH sensing using a novel Raman reporter, arene chromium tricarbonyl linked aminothiophenol (Cr(CO)3-ATP), functionalized onto a nano-roughened planar substrates coated with gold. Unlike the SERS spectrum of the ATP molecule that dominates in the 400-1700 cm(-1) region, which is highly interfered by bio-molecules signals, metal carbonyl-ATP (Cr(CO)3)-ATP) offers the advantage of monitoring the pH dependent strong CO stretching vibrations in the mid-IR (1800-2200 cm(-1)) range. Raman signal of the CO stretching vibrations at ~1820 cm(-1) has strong dependency on the pH value of the environment, where its peak undergo noticeable shift as the pH of the medium is varied from 3.0 to 9.0. The sensor showed better sensitivity in the acidic range of the pH. We also demonstrate the pH sensing in a urine sample, which has high ionic strength and our data closely correlate to the value obtained from conventional sensor. In future, this study may lead to a sensitive chip based pH sensing platform in bio-fluids for the early diagnosis of diseases. © 2013 Published by Elsevier B.V.

  4. SERS-Fluorescence Dual-Mode pH-Sensing Method Based on Janus Microparticles.

    Science.gov (United States)

    Yue, Shuai; Sun, Xiaoting; Wang, Ning; Wang, Yaning; Wang, Yue; Xu, Zhangrun; Chen, Mingli; Wang, Jianhua

    2017-11-15

    A surface-enhanced Raman scattering (SERS)-fluorescence dual-mode pH-sensing method based on Janus microgels was developed, which combined the advantages of high specificity offered by SERS and fast imaging afforded by fluorescence. Dual-mode probes, pH-dependent 4-mercaptobenzoic acid, and carbon dots were individually encapsulated in the independent hemispheres of Janus microparticles fabricated via a centrifugal microfluidic chip. On the basis of the obvious volumetric change of hydrogels in different pHs, the Janus microparticles were successfully applied for sensitive and reliable pH measurement from 1.0 to 8.0, and the two hemispheres showed no obvious interference. The proposed method addressed the limitation that sole use of the SERS-based pH sensing usually failed in strong acidic media. The gastric juice pH and extracellular pH change were measured separately in vitro using the Janus microparticles, which confirmed the validity of microgels for pH sensing. The microparticles exhibited good stability, reversibility, biocompatibility, and ideal semipermeability for avoiding protein contamination, and they have the potential to be implantable sensors to continuously monitor pH in vivo.

  5. 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.

  6. 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

  7. [Size dependent SERS activity of gold nanoparticles studied by 3D-FDTD simulation].

    Science.gov (United States)

    Li, Li-mei; Fang, Ping-ping; Yang, Zhi-lin; Huang, Wen-da; Wu, De-yin; Ren, Bin; Tian, Zhong-qun

    2009-05-01

    By synthesizing Au nanoparticles with the controllable size from about 16 to 160 nm and measuring their SERS activity, the authors found that Au nanoparticles film with a size in the range of 120-135 nm showed the highest SERS activity with the 632.8 nm excitation, which is different from previous experimental results and theoretical predictions. The three dimensional finite difference time domain (3D-FDTD)method was employed to simulate the size dependent SERS activity. At the 632.8 nm excitation, the particles with a size of 110 nm shows the highest enhancement under coupling condition and presents an enhancement as high as 10(9) at the hot site. If the enhancement is averaged over the whole surface, the enhancement can still be as high as 10(7), in good agreement with our experimental data. For Au nanoparticles with a larger size such as 220 nm, the multipolar effect leads to the appearance of the second maximum enhancement with the increase in particles size. The averaged enhancement for the excitation line of 325 nm is only 10(2).

  8. Silver-gelatine bionanocomposites for qualitative detection of a pesticide by SERS.

    Science.gov (United States)

    Fateixa, S; Soares, S F; Daniel-da-Silva, A L; Nogueira, H I S; Trindade, T

    2015-03-07

    The controlled release of pesticides using hydrogel vehicles is an important procedure to limit the amount of these compounds in the environment, providing an effective way for crop protection. A key-step in the formulation of new materials for these purposes encompasses the monitoring of available pesticides in the gel matrix under variable working conditions. In this work, we report a series of bionanocomposites made of Ag nanoparticles (NPs) and gelatine A for the surface enhanced Raman scattering (SERS) detection of sodium diethyldithiocarbamate (EtDTC) as a pesticide model. These studies demonstrate the effectiveness of these substrates for the detection of EtDTC in aqueous solutions in a concentration as low as 10(-5) M. We have monitored the Raman signal enhancement of this analyte in bionanocomposites having an increasing amount of gelatine due to their relevance in formulating hydrogels of variable gel strengths. Under these conditions, the bionanocomposites have shown an effective SERS activity using EtDTC, demonstrating their effectiveness in the qualitative detection of this analyte. Finally, experiments involving the release of EtDTC from Ag/gelatine samples have been monitored by SERS, which attest the potential of this spectroscopic method in the laboratorial monitoring of hydrogels for pesticide release.

  9. SERS and DFT study of water on metal cathodes of silver, gold and platinum nanoparticles.

    Science.gov (United States)

    Li, Jian-Feng; Huang, Yi-Fan; Duan, Sai; Pang, Ran; Wu, De-Yin; Ren, Bin; Xu, Xin; Tian, Zhong-Qun

    2010-03-14

    The observed surface-enhanced Raman scattering (SERS) spectra of water adsorbed on metal film electrodes of silver, gold, and platinum nanoparticles were used to infer interfacial water structures on the basis of the change of the electrochemical vibrational Stark tuning rates and the relative Raman intensity of the stretching and bending modes. To explain the increase of the relative Raman intensity ratio of the bending and stretching vibrations at the very negative potential region, density functional theory calculations provide the conceptual model. The specific enhancement effect for the bending mode was closely associated with the water adsorption structure in a hydrogen bonded configuration through its H-end binding to surface sites with large polarizability due to strong cathodic polarization. The present results allow us to propose that interfacial water molecules exist on these metal cathodes with different hydrogen bonding interactions, i.e., the HO-HH-Pt dihydrogen bond for platinum and the HO-HAg(Au) for silver and gold. This dihydrogen bonding configuration on platinum is further supported from observation of the Pt-H stretching band. Furthermore, the influences of the pH effect on SERS intensity and vibrational Stark effect on the gold electrode indicate that the O-H stretching SERS signals are enhanced in the alkaline solutions because of the hydrated hydroxide surface species adsorbed on the gold cathode.

  10. SERS-Based Flavonoid Detection Using Ethylenediamine-β-Cyclodextrin as a Capturing Ligand

    Directory of Open Access Journals (Sweden)

    Jae Min Choi

    2017-01-01

    Full Text Available Ethylenediamine-modified β-cyclodextrin (Et-β-CD was immobilized on aggregated silver nanoparticle (NP-embedded silica NPs (SiO2@Ag@Et-β-CD NPs for the effective detection of flavonoids. Silica NPs were used as the template for embedding silver NPs to create hot spots and enhance surface-enhanced Raman scattering (SERS signals. Et-β-CD was immobilized on Ag NPs to capture flavonoids via host-guest inclusion complex formation, as indicated by enhanced ultraviolet absorption spectra. The resulting SiO2@Ag@Et-β-CD NPs were used as the SERS substrate for detecting flavonoids, such as hesperetin, naringenin, quercetin, and luteolin. In particular, luteolin was detected more strongly in the linear range 10−7 to 10−3 M than various organic molecules, namely ethylene glycol, β-estradiol, isopropyl alcohol, naphthalene, and toluene. In addition, the SERS signal for luteolin captured by the SiO2@Ag@Et-β-CD NPs remained even after repeated washing. These results indicated that the SiO2@Ag@Et-β-CD NPs can be used as a rapid, sensitive, and selective sensor for flavonoids.

  11. 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.

  12. Synthesis and characterization of silver colloidal nanoparticles with different coatings for SERS application

    International Nuclear Information System (INIS)

    Mikac, L.; Ivanda, M.; Gotić, M.; Mihelj, T.; Horvat, L.

    2014-01-01

    Silver colloids were produced by chemical reduction of silver salt (silver nitrate, AgNO 3 ) solution. As reducing agents, trisodium citrate, sodium borohydride, ascorbic acid, polyvinylpyrrolidone, and glucose were used. The colloids were characterized by UV–Vis, DLS, zeta potential measurements, and SEM. The colloids were stabilized with negative groups or large molecules attached to their surface. The surface-enhanced Raman scattering (SERS) effect of stabilized nanoparticles was measured by using pyridine and rhodamine 6G molecules as analytes and NaNO 3 , KCl, and KBr at different concentrations as aggregating agents. The best Raman signal enhancement was achieved using silver nanoparticles of 40 nm size reduced and stabilized with citrate. The SERS signal of analyte molecules was further enhanced with the addition of sodium borohydride as an alternative aggregating agent. The borohydride had the strongest impact on the SERS effect of the colloid consistent of large (0.5 µm) silver nanoparticles stabilized with aminodextran. The mixture colloid-borohydride-pyridine was stable for hours. The mechanism of borohydride in the colloids is discussed

  13. Synthesis and characterization of silver colloidal nanoparticles with different coatings for SERS application

    Energy Technology Data Exchange (ETDEWEB)

    Mikac, L.; Ivanda, M., E-mail: ivanda@irb.hr [Ruđer Bošković Institute, Laboratory for Molecular Physics (Croatia); Gotić, M. [Ruđer Bošković Institute, Laboratory for Synthesis of New Materials (Croatia); Mihelj, T. [Ruđer Bošković Institute, Laboratory for Synthesis and Processes of Self-assembling of Organic Molecules (Croatia); Horvat, L. [Ruđer Bošković Institute, Laboratory for Electron Microscopy (Croatia)

    2014-12-15

    Silver colloids were produced by chemical reduction of silver salt (silver nitrate, AgNO{sub 3}) solution. As reducing agents, trisodium citrate, sodium borohydride, ascorbic acid, polyvinylpyrrolidone, and glucose were used. The colloids were characterized by UV–Vis, DLS, zeta potential measurements, and SEM. The colloids were stabilized with negative groups or large molecules attached to their surface. The surface-enhanced Raman scattering (SERS) effect of stabilized nanoparticles was measured by using pyridine and rhodamine 6G molecules as analytes and NaNO{sub 3}, KCl, and KBr at different concentrations as aggregating agents. The best Raman signal enhancement was achieved using silver nanoparticles of 40 nm size reduced and stabilized with citrate. The SERS signal of analyte molecules was further enhanced with the addition of sodium borohydride as an alternative aggregating agent. The borohydride had the strongest impact on the SERS effect of the colloid consistent of large (0.5 µm) silver nanoparticles stabilized with aminodextran. The mixture colloid-borohydride-pyridine was stable for hours. The mechanism of borohydride in the colloids is discussed.

  14. 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.

  15. Quantitative SERS Detection of Dopamine in Cerebrospinal Fluid by Dual-Recognition-Induced Hot Spot Generation.

    Science.gov (United States)

    Zhang, Kun; Liu, Yu; Wang, Yuning; Zhang, Ren; Liu, Jiangang; Wei, Jia; Qian, Hufei; Qian, Kun; Chen, Ruoping; Liu, Baohong

    2018-05-09

    Reliable profiling of the extracellular dopamine (DA) concentration in the central nervous system is essential for a deep understanding of its biological and pathological functions. However, quantitative determination of this neurotransmitter remains a challenge because of the extremely low concentration of DA in the cerebrospinal fluid (CSF) of patients. Herein, on the basis of the specific recognition of boronate toward diol and N-hydroxysuccinimide ester toward the amine group, a simple and highly sensitive strategy was presented for DA detection by using surface-enhanced Raman scattering (SERS) spectroscopy as a signal readout. This was realized by first immobilizing 3,3'-dithiodipropionic acid di( N-hydroxysuccinimide ester) on gold thin film surfaces to capture DA, followed by introducing 3-mercaptophenylboronic acid (3-MPBA)-functionalized silver nanoparticles to generate numerous plasmonic "hot spots" with the nanoparticle-on-mirror geometry. Such a dual-recognition mechanism not only avoids complicated bioelement-based manipulations but also efficiently decreases the background signal. With the direct use of the recognition probe 3-MPBA as a Raman reporter, the "signal-on" SERS method was employed to quantify the concentration of DA from 1 pM to 1 μM with a detection limit of 0.3 pM. Moreover, our dual-recognition-directed SERS assay exhibited a high resistance to cerebral interference and was successfully applied to monitoring of DA in CSF samples of patients.

  16. 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

  17. Development of chitosan-coated gold nanoflowers as SERS-active probes

    Science.gov (United States)

    Xu, Dan; Gu, Jiangjiang; Wang, Weina; Yu, Xuehai; Xi, Kai; Jia, Xudong

    2010-09-01

    Surface-enhanced Raman scattering (SERS) has been intensely researched for many years as a potential technique for highly sensitive detection. This work, through the reduction of HAuCl4 with pyrrole in aqueous solutions, investigated a facile one-pot synthesis of flower-like Au nanoparticles with rough surfaces. The formation process of the Au nanoflowers (AuNFs) was carefully studied, and a spontaneous assembly mechanism was proposed based on the time-course experimental results. The key synthesis strategy was to use pyrrole as a weak particle stabilizing and reducing agent to confine crystal growth in the limited ligand protection region. The nanometer-scale surface roughness of AuNFs provided several hot spots on a single particle, which significantly increased SERS enhancement. Good biocompatible stable Raman-active probes were synthesized by coating AuNFs with chitosan. The conservation of the SERS effects in living cells suggested that the chitosan-capped AuNFs could be suitable for highly sensitive detection and have potential for targeting of tumors in vivo.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. Au@Ag core/shell cuboids and dumbbells: Optical properties and SERS response

    Science.gov (United States)

    Khlebtsov, Boris N.; Liu, Zhonghui; Ye, Jian; Khlebtsov, Nikolai G.

    2015-12-01

    Recent studies have conclusively shown that the plasmonic properties of Au nanorods can be finely controlled by Ag coating. Here, we investigate the effect of asymmetric silver overgrowth of Au nanorods on their extinction and surface-enhanced Raman scattering (SERS) properties for colloids and self-assembled monolayers. Au@Ag core/shell cuboids and dumbbells were fabricated through a seed-mediated anisotropic growth process, in which AgCl was reduced by use of Au nanorods with narrow size and shape distribution as seeds. Upon tailoring the reaction rate, monodisperse cuboids and dumbbells were synthesized and further transformed into water-soluble powders of PEGylated nanoparticles. The extinction spectra of AuNRs were in excellent agreement with T-matrix simulations based on size and shape distributions of randomly oriented particles. The multimodal plasmonic properties of the Au@Ag cuboids and dumbbells were investigated by comparing the experimental extinction spectra with finite-difference time-domain (FDTD) simulations. The SERS efficiencies of the Au@Ag cuboids and dumbbells were compared in two options: (1) individual SERS enhancers in colloids and (2) self-assembled monolayers formed on a silicon wafer by drop casting of nanopowder solutions mixed with a drop of Raman reporters. By using 1,4-aminothiophenol Raman reporter molecules, the analytical SERS enhancement factor (AEF) of the colloidal dumbbells was determined to be 5.1×106, which is an order of magnitude higher than the AEF=4.0×105 for the cuboids. This difference can be explained by better fitting of the dumbbell plasmon resonance to the excitation laser wavelength. In contrast to the colloidal measurements, the AEF=5×107 of self-assembled cuboid monolayers was almost twofold higher than that for dumbbell monolayers, as determined with rhodamine 6G Raman reporters. According to TEM data and electromagnetic simulations, the better SERS response of the self-assembled cuboids is due to uniform

  3. 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

  4. 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

  5. {331}-Faceted trisoctahedral gold nanocrystals: synthesis, superior electrocatalytic performance and highly efficient SERS activity

    Science.gov (United States)

    Song, Yahui; Miao, Tingting; Zhang, Peina; Bi, Cuixia; Xia, Haibing; Wang, Dayang; Tao, Xutang

    2015-04-01

    We investigate the effect of gold (Au) seeds prepared in cetyltrimethylammonium chloride solution (CTAC-Au seeds) on the index facets of trisoctahedral gold nanocrystals (TOH Au NCs). We demonstrate that monodisperse {331}-faceted TOH Au NCs with controllable sizes (from 60 to 255 nm) can be successfully prepared in high yield by using 3.0 nm CTAC-Au seeds or as-prepared 70 nm TOH Au NCs as seeds. We find that the electrocatalytic performance on methanol oxidation and surface enhancement Raman spectroscopy (SERS) activity of {331}-faceted TOH Au NCs is size-dependent. In comparison with well-known nanoporous gold (0.088 mA cm-2), {331}-faceted TOH Au NCs with sizes of 110 nm exhibit fairly high catalytic activity (0.178 mA cm-2) on methanol oxidation (1.0 M) in alkaline media due to the presence of increasing density of atomic steps, ledges, and kinks on the NC surfaces. Their current density is reduced by less than 7% after 500 cycling tests. {331}-Faceted TOH Au NCs with sizes of 175 nm exhibit the highest SERS activity for 4-aminothiophenol (4-ATP) molecules. The enhancement factors of a1 modes of 4-ATP molecules can reach the order of 109 when the 4-ATP concentration is 3 × 10-6 M. Moreover, Raman signals (ag modes) of 4,4'-dimercaptoazobenzene (DMAB) molecules on TOH Au NCs are stronger than those on spherical Au NCs of comparable size due to the enhanced laser-induced transformation of 4-ATP molecules by high-index {331}-facets during SERS measurement. Furthermore, the SERS intensities of 4-methylbenzenethiol (4-MTP) molecules on TOH Au NCs are also higher than those on spherical Au NCs of comparable size due to sharp extremities.We investigate the effect of gold (Au) seeds prepared in cetyltrimethylammonium chloride solution (CTAC-Au seeds) on the index facets of trisoctahedral gold nanocrystals (TOH Au NCs). We demonstrate that monodisperse {331}-faceted TOH Au NCs with controllable sizes (from 60 to 255 nm) can be successfully prepared in high yield by

  6. Nurses in advanced roles: a review of acceptability in Portugal Las enfermeras de competencias avanzadas: una revisión de aceptación en Portugal Enfermeiros em funções avançadas: uma análise da aceitação em Portugal

    Directory of Open Access Journals (Sweden)

    James Buchan

    2013-02-01

    Full Text Available OBJECTIVE: This paper focuses on the policy context for the deployment of nurses in advanced roles, with particular reference to Portugal. The health sector in Portugal, as in all countries, is labour intensive, and the scope to utilise nurses in more advanced roles is currently being debated. METHODS: Mixed methods were used: an analysis of international data on the nursing workforce; an analysis of documents and media articles; interviews with key-informants; an online survey of managers, and a technical workshop with key-informants. CONCLUSIONS: The limited evidence base on nurses in advanced roles in Portugal is a constraint on progress, but it is not an excuse for inaction. Further research in Portugal on health professionals in innovative roles would assist in informing policy direction. There is the need to move forward with a fully informed policy dialogue, taking account of the current political, economic and health service realities of Portugal.OBJETIVO: Este estudio se focaliza en el contexto político del desarrollo de competencias avanzadas de enfermería, con énfasis en el caso portugués. El sector de la salud en Portugal, como en todos los países, es intensivo en mano de obra, y la posibilidad de utilizar enfermeros en funciones más avanzadas está actualmente en debate. MÉTODOS: Fue utilizado una aproximación mixta: análisis de datos internacionales sobre la fuerza de trabajo de enfermería; análisis de documentos y noticias; entrevistas con informadores clave; un cuestionario online y una oficina técnica con informadores clave. CONCLUSIONES: La limitada base de evidencia sobre la extensión de competencias de los enfermeros en Portugal es un obstáculo para el progreso pero no es una excusa para la inacción. Investigación adicional sobre profesionales de la salud en papeles innovadores podría ayudar a informar y direccionar la decisión política. Es necesario avanzar con un diálogo político plenamente informado

  7. 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...

  8. Ser hombre o ser mujer a través de la música: una encuesta a jóvenes de Barcelona

    Directory of Open Access Journals (Sweden)

    Josep Martí

    1999-10-01

    Full Text Available Este artigo trata da problemática da relação entre gênero e música. Sabemos que a música como meio de comunicação contribui também para a construção social da realidade; se nos interessamos pela música como fenômeno sócio-cultural, então o aspecto de gênero constitui uma dimensão que não pode ser ignorada. Ao longo deste artigo, apresentarei alguns dados relativos a uma pesquisa tipo survey realizada com jovens barcelonenses durante o outono de 1995. Entre os diferentes objetivos da pesquisa buscava-se obter informações sobre o significado e funções da música na sociedade catalã, com algumas questões orientadas para tratar do papel que desempenha a música nas relações de gênero. Concretamente, os resultados da amostra nos aportam dados sobre o uso da música como estratégia de identidade de gênero, assim como sobre as funções que pode exercer a música como expressão e ao mesmo tempo recurso de manutenção das relações de gênero, que em nossa sociedade caracterizam-se pela sua natureza assimétrica.

  9. 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

  10. A FILOSOFIA DOS JOVENS SOBRE O SER JOVEM: UMA PESQUISA SOCIOPOÉTICA

    Directory of Open Access Journals (Sweden)

    Cristianne Teixeira Carneiro

    2015-02-01

    Full Text Available Objetivou-se conhecer os modos de pensar dos jovens de um curso técnico em enfermagem de um colégio técnico federal sobre “o que é ser jovem?”. A pesquisa se insere no paradigma qualitativo de investigação utilizando a Sociopoética, foi realizada com 11 jovens que cursavam o ensino médio concomitante ao técnico em enfermagem em 2013. Os jovens problematizaram a dimensão do tempo de espera para o mundo adulto, mostrando que não há um único modo de ser jovem e nem de se tornar adulto, pois para eles os ritos de passagem eram: casamento, saída da casa dos pais, o ingresso em um colégio técnico federal e o início dos estágios do curso técnico em enfermagem, demonstrando que esse momento não é fixo e nem demarcado. Eles também relataram jeitos de ser jovem em bandos que agem de modo diferente. Discutiram o tempo e a liberdade, ressaltando o quanto a rotina do jovem está relacionada à escola. Essa pesquisa possibilitou a oportunidade de reflexão sobre os conceitos sobre jovens, muitas vezes cristalizados numa sociedade que raramente leva em consideração a voz de quem mais entende sobre si mesmo, ou seja, do próprio sujeito que tem a experiência e vivencia a juventude.

  11. SYNTHESIS OF MULTI-LAYER SUBSTRATE FOR OBSERVING OF HYDROXYBENZOIC ACIDS MOLECULES BY SERS

    Directory of Open Access Journals (Sweden)

    E. A. Yasenko

    2015-05-01

    Full Text Available Subject of study. The paper deals with the results of the multilayer substrate synthesis having an effect of SERS from hydroxybenzoic acid molecules which are adsorbed on its surface. Methods. To produce SERS substrate we have applied colloid chemistry methods: washing of colloids using a laboratory centrifuge OPn-8, carrying out serial chemical reactions for modifying the surface of semiconductor particles of SiO2 in the solution, determining the maximum of the absorption spectrum of the substrate obtained (in the range from 400 to 1000 nm. To observe hydroxybenzoic acids molecules the method of Raman scattering on OPTEC-785 Video-M spectrometer has been used. Main results. A new method of the substrate chemical synthesis is proposed, which has the effect of SERS by radiationexcitation wavelength of 785 nm, based on micron silica particles with immobilized surface of gold and silver. Raman spectra of hydroxybenzoic acids (Gallic and p-hydroxybenzoic in free and adsorbed state have been experimentally obtained and interpreted. It was shown that both acids in a crystalline state are in the form of dimers. Also, the presence of a certain group of characteristic bands indicates that the hydroxybenzoic acid is chemically bonded to the substrate surface through an oxygen bridge of deprotonated hydroxyl groups. However, unlike Gallic acid, p-hydroxybenzoic acid passes into the monomer form. Practical significance. This technique for enhancing substrate preparation is usable in the laboratory without sophisticated technical equipment. Experimental data on the method of securing the hydroxybenzoic acids and form of their existence on the surface of the substrate will be useful in the design of sensor systems based on them. Characteristic bands of undistorted aromatic ring of hydroxybenzoic acids may also be used in developing

  12. Seeded Growth Synthesis of Gold Nanotriangles: Size Control, SAXS Analysis, and SERS Performance.

    Science.gov (United States)

    Kuttner, Christian; Mayer, Martin; Dulle, Martin; Moscoso, Ana; López-Romero, Juan Manuel; Förster, Stephan; Fery, Andreas; Pérez-Juste, Jorge; Contreras-Cáceres, Rafael

    2018-04-04

    We studied the controlled growth of triangular prismatic Au nanoparticles with different beveled sides for surface-enhanced Raman spectroscopy (SERS) applications. First, in a seedless synthesis using 3-butenoic acid (3BA) and benzyldimethylammonium chloride (BDAC), gold nanotriangles (AuNTs) were synthesized in a mixture with gold nanooctahedra (AuNOCs) and separated by depletion-induced flocculation. Here, the influence of temperature, pH, and reducing agent on the reaction kinetics was initially investigated by UV-vis and correlated to the size and yield of AuNT seeds. In a second step, the AuNT size was increased by seed-mediated overgrowth with Au. We show for the first time that preformed 3BA-synthesized AuNT seeds can be overgrown up to a final edge length of 175 nm and a thickness of 80 nm while maintaining their triangular shape and tip sharpness. The NT morphology, including edge length, thickness, and tip rounding, was precisely characterized in dispersion by small-angle X-ray scattering and in dry state by transmission electron microscopy and field-emission scanning electron microscopy. For sensor purposes, we studied the size-dependent SERS performance of AuNTs yielding analytical enhancement factors between 0.9 × 10 4 and 5.6 × 10 4 and nanomolar limit of detection (10 -8 -10 -9 M) for 4-mercaptobenzoic acid and BDAC. These results confirm that the 3BA approach allows the fabrication of AuNTs in a whole range of sizes maintaining the NT morphology. This enables tailoring of localized surface plasmon resonances between 590 and 740 nm, even in the near-infrared window of a biological tissue, for use as colloidal SERS sensing agents or for optoelectronic applications.

  13. Phosphorylation of Mycobacterium tuberculosis Ser/Thr phosphatase by PknA and PknB.

    Directory of Open Access Journals (Sweden)

    Andaleeb Sajid

    2011-03-01

    Full Text Available The integrated functions of 11 Ser/Thr protein kinases (STPKs and one phosphatase manipulate the phosphorylation levels of critical proteins in Mycobacterium tuberculosis. In this study, we show that the lone Ser/Thr phosphatase (PstP is regulated through phosphorylation by STPKs.PstP is phosphorylated by PknA and PknB and phosphorylation is influenced by the presence of Zn(2+-ions and inorganic phosphate (Pi. PstP is differentially phosphorylated on the cytosolic domain with Thr(137, Thr(141, Thr(174 and Thr(290 being the target residues of PknB while Thr(137 and Thr(174 are phosphorylated by PknA. The Mn(2+-ion binding residues Asp(38 and Asp(229 are critical for the optimal activity of PstP and substitution of these residues affects its phosphorylation status. Native PstP and its phosphatase deficient mutant PstP(c (D38G are phosphorylated by PknA and PknB in E. coli and addition of Zn(2+/Pi in the culture conditions affect the phosphorylation level of PstP. Interestingly, the phosphorylated phosphatase is more active than its unphosphorylated equivalent.This study establishes the novel mechanisms for regulation of mycobacterial Ser/Thr phosphatase. The results indicate that STPKs and PstP may regulate the signaling through mutually dependent mechanisms. Consequently, PstP phosphorylation may play a critical role in regulating its own activity. Since, the equilibrium between phosphorylated and non-phosphorylated states of mycobacterial proteins is still unexplained, understanding the regulation of PstP may help in deciphering the signal transduction pathways mediated by STPKs and the reversibility of the phenomena.

  14. 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.

  15. Surface Enhanced Raman Spectroscopy (SERS) methods for endpoint and real-time quantification of miRNA assays

    Science.gov (United States)

    Restaino, Stephen M.; White, Ian M.

    2017-03-01

    Surface Enhanced Raman spectroscopy (SERS) provides significant improvements over conventional methods for single and multianalyte quantification. Specifically, the spectroscopic fingerprint provided by Raman scattering allows for a direct multiplexing potential far beyond that of fluorescence and colorimetry. Additionally, SERS generates a comparatively low financial and spatial footprint compared with common fluorescence based systems. Despite the advantages of SERS, it has remained largely an academic pursuit. In the field of biosensing, techniques to apply SERS to molecular diagnostics are constantly under development but, most often, assay protocols are redesigned around the use of SERS as a quantification method and ultimately complicate existing protocols. Our group has sought to rethink common SERS methodologies in order to produce translational technologies capable of allowing SERS to compete in the evolving, yet often inflexible biosensing field. This work will discuss the development of two techniques for quantification of microRNA, a promising biomarker for homeostatic and disease conditions ranging from cancer to HIV. First, an inkjet-printed paper SERS sensor has been developed to allow on-demand production of a customizable and multiplexable single-step lateral flow assay for miRNA quantification. Second, as miRNA concentrations commonly exist in relatively low concentrations, amplification methods (e.g. PCR) are therefore required to facilitate quantification. This work presents a novel miRNA assay alongside a novel technique for quantification of nuclease driven nucleic acid amplification strategies that will allow SERS to be used directly with common amplification strategies for quantification of miRNA and other nucleic acid biomarkers.

  16. 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...

  17. Aprender a ser incompetente en educación física: un enfoque psicosocial

    OpenAIRE

    Ruiz Pérez, Luis Miguel

    2000-01-01

    Aprender a ser incapaz de dominar las habilidades en educación física es uno de los muchos fenómenos que pueden suceder. Los últimos veinte años han mostrado como en los diferentes contextos educativos, un sector del alumnado no dispone de los recursos necesarios para poder solventar las exigencias de las materias escolares y desarrollan un sentimiento de desmoralización y desvalimiento que les lleva a aceptar su condición, y abandonar cualquier intento por aprender. Este fenómeno también ocu...

  18. 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

  19. 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.

  20. La bioluminiscencia como recurso para potenciar la capacidad creativa del ser humano

    OpenAIRE

    Laugerud Tabarini, Isabel

    2014-01-01

    La bioluminiscencia, capacidad que poseen algunos organismos vivos de producir luz, ocurre mayormente en hábitats marinos donde raramente tiene testigos humanos. Al asombro natural que nos causa lo desconocido se le suma la particularidad de este fenómeno, poco representado y que además nos es solamente evidente en total ausencia de luz. Fuera de su zona de confort es donde el ser humano generalmente incrementa su habilidad de generar y/o conectar ideas para crear algo e implementarlo en su r...

  1. Delivering happiness at UEM: aprendiendo a ser feliz en el trabajo

    OpenAIRE

    Vidal García, Marta Esmeralda; Linati, Andrea

    2014-01-01

    El objetivo último de cualquier persona es ser feliz, todo aquello que hacemos está encaminado a alcanzar dicha meta. La felicidad es el pilar sólido que nos permitirá alcanzar el éxito tanto en lo personal como en lo profesional. Cuando somos felices en el trabajo, estamos más motivados, rendimos más, somos más productivos, mejores compañeros, tenemos mejores ideas, etc., y todo ello aumenta enormemente las probabilidades de tener éxito. La felicidad pronostica importantes res...

  2. S6K1 is involved in polyploidization through its phosphorylation at Thr421/Ser424.

    Science.gov (United States)

    Ma, Dongchu; Yu, Huiying; Lin, Di; Sun, Yinghui; Liu, Liping; Liu, Yage; Dai, Bing; Chen, Wei; Cao, Jianping

    2009-04-01

    Studies on polyploidization of megakaryocytes have been hampered by the lack of synchronized polyploid megakaryocytes. In this study, a relatively synchronized polyploid cell model was successfully established by employing Dami cells treated with nocodazole. In nocodazole-induced cells, cyclin B expression oscillated normally as in diploid cells and polyploid megakaryocytes. By using the nocodazole-induced Dami cell model, we found that 4E-BP1 and Thr421/Ser424 of ribosomal S6 kinase 1(S6K1) were phosphorylated mostly at M-phase in cytoplasm and oscillated in nocodazole-induced polyploid Dami cells, concomitant with increased expression of p27 and cyclin D3. However, phosphorylation of 4E-BP1 and S6K1 on Thr421/Ser424 was significantly decreased in differentiated Dami cells induced by phorbol 12-myristate 13-acetate (PMA), concomitant with increased expression of cyclin D1 and p21 and cyclin D3. Overexpression of the kinase dead form of S6K1 containing the mutation Lys 100 --> Gln in PMA-induced Dami cells increased ploidy whereas overexpression of rapamycin-resistant form of S6K1 containing the mutations Thr421 --> Glu and Ser424 --> Asp significantly dephosphorylated 4E-BP1 and reduced expression of cyclin D1, cyclin D3, p21 and p27, and slightly decreased the ploidy of PMA-induced Dami cells, compared with treatment with PMA alone. Moreover, overexpression of rapamycin-resistant form of S6K1 significantly reversed polyploidization of nocodazole-induced Dami cells. Furthermore, MAP (a novel compound synthesized recently) partly blocked the phosphorylation of S6K1 on Thr421/Ser424 and decreased the expression of p27 and polyploidization in nocodazole-induced Dami cells. Taken together, these data suggested that S6K1/4E-BP1 pathway may play an important role in polyploidization of megakaryocytes. (c) 2008 Wiley-Liss, Inc.

  3. Ab Initio Calculations and Raman and SERS Spectral Analyses of Amphetamine Species

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Nørbygaard, Thomas; White, Peter C.

    2011-01-01

    For the first time, the differences between the spectra of amphetamine and amphetamine-H+ and between different conformers are thoroughly studied by ab initio model calculations, and Raman and surface-enhanced Raman spectroscopy (SERS) spectra are measured for different species of amphetamine....... The spectra of amphetamine and amphetamine-H+ sampleswere obtained and assigned according to a comparison of the experimental spectra and the ab initio MO calculations, performed using the Gaussian 03W program (Gaussian, Inc., Pittsburgh, PA). The analyses were based on complete geometry minimization...

  4. Neutron beam irradiation study of workload dependence of SER in a microprocessor

    Energy Technology Data Exchange (ETDEWEB)

    Michalak, Sarah E [Los Alamos National Laboratory; Graves, Todd L [Los Alamos National Laboratory; Hong, Ted [STANFORD; Ackaret, Jerry [IBM; Sonny, Rao [IBM; Subhasish, Mitra [STANFORD; Pia, Sanda [IBM

    2009-01-01

    It is known that workloads are an important factor in soft error rates (SER), but it is proving difficult to find differentiating workloads for microprocessors. We have performed neutron beam irradiation studies of a commercial microprocessor under a wide variety of workload conditions from idle, performing no operations, to very busy workloads resembling real HPC, graphics, and business applications. There is evidence that the mean times to first indication of failure, MTFIF defined in Section II, may be different for some of the applications.

  5. 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 ...

  6. Smart supramolecular sensing with cucurbit[n]urils: probing hydrogen bonding with SERS.

    Science.gov (United States)

    de Nijs, Bart; Kamp, Marlous; Szabó, Istvan; Barrow, Steven J; Benz, Felix; Wu, Guanglu; Carnegie, Cloudy; Chikkaraddy, Rohit; Wang, Wenting; Deacon, William M; Rosta, Edina; Baumberg, Jeremy J; Scherman, Oren A

    2017-12-04

    Rigid gap nano-aggregates of Au nanoparticles formed using cucurbit[n]uril (CB[n]) molecules are used to investigate the competitive binding of ethanol and methanol in an aqueous environment. We show it is possible to detect as little as 0.1% methanol in water and a ten times higher affinity to methanol over ethanol, making this a useful technology for quality control in alcohol production. We demonstrate strong interaction effects in the SERS peaks, which we demonstrate are likely from the hydrogen bonding of water complexes in the vicinity of the CB[n]s.

  7. 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...

  8. SERS substrates fabricated using ceramic filters for the detection of bacteria: Eliminating the citrate interference

    Science.gov (United States)

    Mosier-Boss, P. A.; Sorensen, K. C.; George, R. D.; Sims, P. C.; O'braztsova, A.

    2017-06-01

    It was found that spectra obtained for bacteria on SERS substrates fabricated by filtering citrate-generated Ag nanoparticles (NPs) onto rigid, ceramic filters exhibited peaks due to citrate as well as the bacteria. In many cases the citrate spectrum overwhelmed that of the bacteria. Given the simplicity of the method to prepare these substrates, means of eliminating this citrate interference were explored. It was found that allowing a mixture of bacteria suspension and citrate-generated Ag NPs to incubate prior to filtering onto the ceramic filter eliminated this interference.

  9. 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.

  10. 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...

  11. ABOUT PROBABILITY OF RESEARCH OF THE NN Ser SPECTRUM BY MODEL ATMOSPHERES METHOD

    OpenAIRE

    Sakhibullin, N. A.; Shimansky, V. V.

    2017-01-01

    The spectrum of close binary system NN Ser is investigated by a models atmospheres method. It is show that the atmosphere near the centrum of a hot spot on surface of red dwarf has powerful chromospheres, arising from heating in Laiman continua. Four models of binary system with various of parameters are constructed and their theoretical spectra are obtained. Temperature of white dwarf Tef = 62000 K, radius of the red dwarf RT = 0.20139 and angle inclination of system i = 82“ are determined. ...

  12. El significado de ser estudiante de Psicología Universidad de Manizales

    OpenAIRE

    López Insuasty, Isabel Cristina

    2015-01-01

    Tesis (Maestría en Educación. Docencia). Universidad de Manizales. Facultad de Educación y Psicología, 2004 La presente investigación pretende da respuesta a la pregunta ¿Qué significa ser estudiante de Psicología? en el marco de la Educación Superior como realidad vivida que se constituye en un escenario intersubjetivo en el cual se construye el mundo de la vida de los actores y sus experiencias vividas. Nuevas realidades en la educación superior permite vislumbrar el papel protagónic...

  13. An improved method to unravel phosphoacceptors in Ser/Thr protein kinase-phosphorylated substrates.

    Science.gov (United States)

    Molle, Virginie; Leiba, Jade; Zanella-Cléon, Isabelle; Becchi, Michel; Kremer, Laurent

    2010-11-01

    Identification of the phosphorylated residues of bacterial Ser/Thr protein kinase (STPK) substrates still represents a challenging task. Herein, we present a new strategy allowing the rapid determination of phosphoacceptors in kinase substrates, essentially based on the dual expression of the kinase with its substrate in the surrogate E. coli, followed by MS analysis in a single-step procedure. The performance of this strategy is illustrated using two distinct proteins from Mycobacterium tuberculosis as model substrates, the GroEL2 and HspX chaperones. A comparative analysis with a standard method that includes mass spectrometry analysis of in vitro phosphorylated substrates is also addressed.

  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...... 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...

  15. SERS activity with tenfold detection limit optimization on a type of nanoporous AAO-based complex multilayer substrate

    Science.gov (United States)

    Sui, Chaofan; Wang, Kaige; Wang, Shuang; Ren, Junying; Bai, Xiaohong; Bai, Jintao

    2016-03-01

    Most of SERS applications are constricted by heterogeneous hotspots and aggregates of nanostructure, which result in low sensitivity and poor reproducibility of characteristic signals. This work intends to introduce SERS properties of a type of SERS-active substrate, Au-CuCl2-AAO, which is innovatively developed on a porous anodic alumina oxide (AAO) template. Spectral measuring results of Rhodamine 6G (R6G) on this substrate optimized by controlling morphology and gold thickness showed that enhancement factor (2.30 × 107) and detection limit (10-10 M) were both improved and represented better performance than its template AAO. Homogenous hot spots across the region of interest were achieved by scanning SERS intensity distribution for the band at 1505 cm-1 in 5 × 5 μm2 area. Furthermore, the promising SERS activity of the flower-patterned substrate was theoretically explained through simulation of the electromagnetic field distribution. In addition, this SERS substrate is proposed for applications within the field of chemical and biochemical analyses.Most of SERS applications are constricted by heterogeneous hotspots and aggregates of nanostructure, which result in low sensitivity and poor reproducibility of characteristic signals. This work intends to introduce SERS properties of a type of SERS-active substrate, Au-CuCl2-AAO, which is innovatively developed on a porous anodic alumina oxide (AAO) template. Spectral measuring results of Rhodamine 6G (R6G) on this substrate optimized by controlling morphology and gold thickness showed that enhancement factor (2.30 × 107) and detection limit (10-10 M) were both improved and represented better performance than its template AAO. Homogenous hot spots across the region of interest were achieved by scanning SERS intensity distribution for the band at 1505 cm-1 in 5 × 5 μm2 area. Furthermore, the promising SERS activity of the flower-patterned substrate was theoretically explained through simulation of the

  16. Electromagnetic Modelling of Raman Enhancement from Nanoscale Structures as a Means to Predict the Efficacy of SERS Substrates

    Directory of Open Access Journals (Sweden)

    Richard J. C. Brown

    2007-01-01

    Full Text Available The requirement to optimise the balance between signal enhancement and reproducibility in surface enhanced Raman spectroscopy (SERS is stimulating the development of novel substrates for enhancing Raman signals. This paper describes the application of finite element electromagnetic modelling to predict the Raman enhancement produced from a variety of SERS substrates with differently sized, spaced and shaped morphologies with nanometre dimensions. For the first time, a theoretical comparison between four major generic types of SERS substrate (including metal nanoparticles, structured surfaces, and sharp tips has been performed and the results are presented and discussed. The results of the modelling are consistent with published experimental data from similar substrates.

  17. Coupling FT Raman and FT SERS microscopy with TLC plates for in situ identification of chemical compounds

    Science.gov (United States)

    Caudin, J. P.; Beljebbar, A.; Sockalingum, G. D.; Angiboust, J. F.; Manfait, M.

    1995-11-01

    Direct analysis of sub-femtogram quantities of chemical compounds on thin layer chromatography plates has been made possible by associating Fourier transform Raman microspectroscopy with SERS spectroscopy. The interfacing elements of the FT Raman microscope system are discussed and optimised such that a lateral resolution on the micron scale is achieved in the sample plane. Micro-FT SERS results obtained from a model biological molecule indicate preservation of molecular conformation upon adsorption at the SERS active surface. With NIR radiation it is thus possible to analyse plates with or without fluorescence indicators.

  18. 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...

  19. 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.

  20. Positive selection at codon 38 of the human KCNE1 (= minK gene and sporadic absence of 38Ser-coding mRNAs in Gly38Ser heterozygotes

    Directory of Open Access Journals (Sweden)

    Pfeufer Arne

    2009-08-01

    Full Text Available Abstract Background KCNE1 represents the regulatory beta-subunit of the slowly activating delayed rectifier potassium channel (IKs. Variants of KCNE1 have repeatedly been linked to the long-QT syndrome (LQTS, a disorder which predisposes to deafness, ventricular tachyarrhythmia, syncope, and sudden cardiac death. Results We here analyze the evolution of the common Gly38Ser variant (rs1805127, using genomic DNAs, complementary DNAs, and HEK293-expressed variants of altogether 19 mammalian species. The between species comparison reveals that the human-specific Gly38Ser polymorphism evolved under strong positive Darwinian selection, probably in adaptation to specific challenges in the fine-tuning of IKs channels. The involved amino acid exchanges (Asp > Gly, Gly > Ser are moderately radical and do not induce apparent changes in posttranslational modification. According to population genetic analyses (HapMap phase II a heterozygote advantage accounts for the maintenance of the Gly38Ser polymorphism in humans. On the other hand, the expression of the 38Ser allele seems to be disadvantageous under certain conditions, as suggested by the sporadic deficiency of 38Ser-coding mRNAs in heterozygote Central Europeans and the depletion of homozygotes 38Ser in the Yoruban sample. Conclusion We speculate that individual differences in genomic imprinting or genomic recoding might have contributed to conflicting results of recent association studies between Gly38Ser polymorphism and QT phenotype. The findings thus highlight the relevance of mRNA data in future association studies of genotypes and clinical disorders. To the best of our knowledge, they moreover provide first time evidence for a unique pattern; i.e. coincidence of positive Darwinian selection and polymorphism with a sporadically suppressed expression of one allele.

  1. 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

  2. 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.

  3. Taladrado de pizarra mediante láser de Nd:Yag

    Directory of Open Access Journals (Sweden)

    Larosi, M. S.

    1998-04-01

    Full Text Available A serie of experiments to investigate the feasibility of using a Nd: YAG laser to process slate tiles and the influence of the processing parameters have been undertaken. The objective of this work is to investigate the capabilities of a Nd:YAG pulsed laser to drill tiny holes in slate tiles, in order to produce a better quality drilled slate tile in a reduced time. Part of the results obtained in a systematic study about the influence of the processing parameters, such as average power, pulse width, frequency, pressure and type of assisting gas is presented.

    Se ha desarrollado una serie de experimentos para investigar la viabilidad del uso de un láser de Nd: YAG para el procesamiento de piezas de pizarra, así como los parámetros que más afectan al proceso. El objetivo concreto de este trabajo es investigar la capacidad de un láser de Nd:YAG pulsado para taladrar orificios de pequeño diámetro en láminas de pizarra, con el fin de obtener mejor calidad de taladrado en un tiempo reducido. Se presenta parte de los resultados obtenidos en un estudio sistemático de la influencia de los parámetros de procesamiento en la forma del orificio, tales como, potencia, duración de pulso, frecuencia, presión y tipo de gas de aportación.

  4. 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.

  5. Monstruos míticos, cuerpos fragmentados y un ser prostituido.

    Directory of Open Access Journals (Sweden)

    María Cecilia Salas.

    1998-06-01

    Full Text Available Las representaciones míticas de la feminidad, la mujer condensada en un órgano y la mujer prostituida en su ser, o lo que sería equivalente: el mito, el fragmento del cuerpo y el pacto $simbólico propio de la prostitución, se han constituido a través de la historia en discursos, símbolos, imágenes y destinos posibles para ese margen enigmático, fantasmal e inaprehensible de la feminidad, margen no capturable en la mujer como género ni en la mujer como madre. Los tres registros son un intento por atrapar algo de la extimidad femenina, tan extranjera pero tan íntima. Tal vez han sido un esfuerzo por hacer hablar a un órgano oscuro y mistérico: unos dientes con ideas, una vagina dentada, de los cuales se espera una revelación que las palabras no profieren, quizá porque simplemente la feminidad es una esfinge sin secreto o un indecible secreto.

  6. La cuestión de la moral en Ser y tiempo de Martin Heidegger

    Directory of Open Access Journals (Sweden)

    Lozano Díaz, Vicente

    2015-08-01

    Full Text Available In Being and Time one can perceive an attempt to establish an ethics of authenticity, as human life is described as a constant endeavour to move forward, establishing goals and striving to achieve them based on decisions and a sense of responsibility grounded in one’s understanding of oneself as an individual and a non-transferable project. But these ethics of authenticity would only be acceptable to Heidegger if considered as an ontological or metaphysical foundation independent from the truths, values or principles which, in turn, are used as criteria for specific conducts and behaviours.Se puede ver en Ser y tiempo el intento de establecer una moral de la autenticidad, pues la vida humana se considera como constante proyectarse hacia adelante, estableciendo metas e intentando cumplirlas a partir de la decisión y de la responsabilidad que surge de la propia comprensión de uno mismo como proyecto individual e intransferible. Pero esta moral de la autenticidad solo sería aceptable para Heidegger si se considerase como fundamento ontológico o metafísico independiente de las verdades, valores o principios que a su vez se utilizarían como criterios para las conductas o comportamientos concretos.

  7. 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.

  8. 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.

  9. 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.

  10. Low-cost silver capped polystyrene nanotube arrays as super-hydrophobic substrates for SERS applications.

    Science.gov (United States)

    Lovera, Pierre; Creedon, Niamh; Alatawi, Hanan; Mitchell, Micki; Burke, Micheal; Quinn, Aidan J; O'Riordan, Alan

    2014-05-02

    In this paper, we describe the fabrication, simulation and characterization of dense arrays of freestanding silver capped polystyrene nanotubes, and demonstrate their suitability for surface enhanced Raman scattering (SERS) applications. Substrates are fabricated in a rapid, low-cost and scalable way by melt wetting of polystyrene (PS) in an anodized alumina (AAO) template, followed by silver evaporation. Scanning electron microscopy reveals that substrates are composed of a dense array of freestanding polystyrene nanotubes topped by silver nanocaps. SERS characterization of the substrates, employing a monolayer of 4-aminothiophenol (4-ABT) as a model molecule, exhibits an enhancement factor of ∼1.6 × 10(6), in agreement with 3D finite difference time domain simulations. Contact angle measurements of the substrates revealed super-hydrophobic properties, allowing pre-concentration of target analyte into a small volume. These super-hydrophobic properties of the samples are taken advantage of for sensitive detection of the organic pollutant crystal violet, with detection down to ∼400 ppt in a 2 μl aliquot demonstrated.

  11. Low-cost silver capped polystyrene nanotube arrays as super-hydrophobic substrates for SERS applications

    International Nuclear Information System (INIS)

    Lovera, Pierre; Creedon, Niamh; Alatawi, Hanan; Mitchell, Micki; Burke, Micheal; Quinn, Aidan J; O’Riordan, Alan

    2014-01-01

    In this paper, we describe the fabrication, simulation and characterization of dense arrays of freestanding silver capped polystyrene nanotubes, and demonstrate their suitability for surface enhanced Raman scattering (SERS) applications. Substrates are fabricated in a rapid, low-cost and scalable way by melt wetting of polystyrene (PS) in an anodized alumina (AAO) template, followed by silver evaporation. Scanning electron microscopy reveals that substrates are composed of a dense array of freestanding polystyrene nanotubes topped by silver nanocaps. SERS characterization of the substrates, employing a monolayer of 4-aminothiophenol (4-ABT) as a model molecule, exhibits an enhancement factor of ∼1.6 × 10 6 , in agreement with 3D finite difference time domain simulations. Contact angle measurements of the substrates revealed super-hydrophobic properties, allowing pre-concentration of target analyte into a small volume. These super-hydrophobic properties of the samples are taken advantage of for sensitive detection of the organic pollutant crystal violet, with detection down to ∼400 ppt in a 2 μl aliquot demonstrated. (paper)

  12. A white-emitting ZnO-Au nanocomposite and its SERS applications

    Energy Technology Data Exchange (ETDEWEB)

    Sun Lanlan [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China); Zhao Dongxu, E-mail: dxzhao2000@yahoo.com.cn [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China); Ding Meng; Zhao Haifeng; Zhang Zhenzhong; Li Binghui; Shen Dezhen [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China)

    2012-08-01

    We reported a simple method to synthesize ZnO-Au nanocomposites (hybrid A) by combining hydrothermal and electric beam evaporation deposition method. It was found that Au deposition time takes an important role in the generation of Au nanoparticles. Changing Au deposition time makes the thickness of Au formed on ZnO nanorods increase from 10 nm to 70 nm. On the other hand, white-emitting ZnO-Au nanocomposites (hybrid B) were obtained after treating hybrid A with HCl solution. Thanks to the covering of Au film and acid etching, it induces many defects on the surface of ZnO NRs, and largely enhances the visible emission of surviving ZnO and finally generates white emission on Au mesocrystals (hybrid B). Both of the ZnO-Au hybrids (A and B) can be applied as substrates in surface-enhanced Raman scattering (SERS) measurement. A typical probe molecule, 4-ATP was used to test the SERS activity of the ZnO-Au composites and the results indicated good Raman activity on the substrates.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. BSA-coated nanoparticles for improved SERS-based intracellular pH sensing.

    Science.gov (United States)

    Zheng, Xiao-Shan; Hu, Pei; Cui, Yan; Zong, Cheng; Feng, Jia-Min; Wang, Xin; Ren, Bin

    2014-12-16

    Local microenvironment pH sensing is one of the key parameters for the understanding of many biological processes. As a noninvasive and high sensitive technique, surface-enhanced Raman spectroscopy (SERS) has attracted considerable interest in the detection of the local pH of live cells. We herein develop a facile way to prepare Au-(4-MPy)-BSA (AMB) pH nanosensor. The 4-MPy (4-mercaptopyridine) was used as the pH sensing molecule. The modification of the nanoparticles with BSA not only provides a high sensitive response to pH changes ranging from pH 4.0 to 9.0 but also exhibits a high sensitivity and good biocompatibility, stability, and reliability in various solutions (including the solutions of high ionic strength or with complex composition such as the cell culture medium), both in the aggregation state or after long-term storage. The AMB pH nanosensor shows great advantages for reliable intracellular pH analysis and has been successfully used to monitor the pH distribution of live cells and can address the grand challenges in SERS-based pH sensing for practical biological applications.

  18. Facile fabrication of silver nanoparticles with temperature-responsive sizes as highly active SERS substrates

    Science.gov (United States)

    Wu, Jing; Fang, Jinghuai; Cheng, Mingfei; Gong, Xiao

    2016-12-01

    In our work, large-scale silver NPs (nanoparticles) are successfully synthesized on zinc foils with controllable size by regulating the temperature of the displacement reaction. Our results show that when the temperature is 70 °C, the average size of silver NPs is approximately 88 nm in diameter, and they exhibit the strongest SERS activity. The gap between nanoparticles is simultaneously regulated as near as possible, which produces abundant "hot spots" and nanogaps. Crystal violet (CV) was used as probe molecules, and the SERS signals show that the values of relative standard deviation in the intensity of the main vibration modes are less than 10%, demonstrating excellent reproducibility of the silver NPs. Furthermore, the high surface-average enhancement factor of 3.86 × 107 is achieved even when the concentration of CV is 10-7 M, which is sufficient for single-molecule detection. We believe that this low cost and rapid route would get wide applications in chemical synthesis.

  19. 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.

  20. 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.

  1. 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

    Aquaporin 4 (AQP4) is the predominant water channel in the mammalian brain and is mainly expressed in the perivascular glial endfeet at the brain-blood interface. AQP4 has been described as an important entry and exit site for water during formation of brain edema and regulation of AQP4 is theref......Aquaporin 4 (AQP4) is the predominant water channel in the mammalian brain and is mainly expressed in the perivascular glial endfeet at the brain-blood interface. AQP4 has been described as an important entry and exit site for water during formation of brain edema and regulation of AQP4...... 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...... of activators and inhibitors of PKG and PKA. Mutation of Ser(111) to alanine or aspartate (to prevent or mimic phosphorylation) did not change the water permeability of AQP4. PKG activation had no effect on the water permeability of AQP4 in primary cultures of rat astrocytes. Molecular dynamics simulations...

  2. Performance Characteristics of Bio-Inspired Metal Nanostructures as Surface-Enhanced Raman Scattered (SERS) Substrates.

    Science.gov (United States)

    Areizaga-Martinez, Hector I; Kravchenko, Ivan; Lavrik, Nickolay V; Sepaniak, Michael J; Hernández-Rivera, Samuel P; De Jesús, Marco A

    2016-09-01

    The fabrication of high-performance plasmonic nanomaterials for bio-sensing and trace chemical detection is a field of intense theoretical and experimental research. The use of metal-silicon nanopillar arrays as analytical sensors has been reported with reasonable results in recent years. The use of bio-inspired nanocomposite structures that follow the Fibonacci numerical architecture offers the opportunity to develop nanostructures with theoretically higher and more reproducible plasmonic fields over extended areas. The work presented here describes the nanofabrication process for a series of 40 µm × 40 µm bio-inspired arrays classified as asymmetric fractals (sunflower seeds and romanesco broccoli), bilaterally symmetric (acacia leaves and honeycombs), and radially symmetric (such as orchids and lily flowers) using electron beam lithography. In addition, analytical capabilities were evaluated using surface-enhanced Raman scattering (SERS). The substrate characterization and SERS performance of the developed substrates as the strategies to assess the design performance are presented and discussed. © The Author(s) 2016.

  3. 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.

  4. 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.

  5. Danmark læser - en kulturkampagne mellem flere tider og mange dagsordner

    DEFF Research Database (Denmark)

    Dalsgård, Anne Line; Lund, Niels D.

    2016-01-01

    The national campaign Denmark is reading (Danmark læser) was carried out in the years 2013-15 and was a significant cultural policy initiative – the biggest of its kind ever in Denmark – with the object of getting more Danes to read fiction. This article describes the aim and contents of the camp......The national campaign Denmark is reading (Danmark læser) was carried out in the years 2013-15 and was a significant cultural policy initiative – the biggest of its kind ever in Denmark – with the object of getting more Danes to read fiction. This article describes the aim and contents...... of the campaign and analyses its position at the interface between established educational thinking and contemporary event culture, as well as considering its relations to other current agendas in the politics of culture and literature: the book market, literacy, public libraries, the concept of dissemination...... into perspective sections of contemporary Scandinavian research about books, literature, reading and the dissemination of literature. The campaign was characterised by its broad social and geographical scope, which both retained Danish public libraries as central players and involved a great number of innovative...

  6. 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

  7. 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.

  8. 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.

  9. Plasmonic nanoholes as SERS devices for biosensing applications: An easy route for nanostructures fabrication on glass substrates

    KAUST Repository

    Candeloro, Patrizio; Iuele, Ernesto; Perozziello, Gerardo; Coluccio, Maria Laura; Gentile, Francesco; Malara, Natalia; Mollace, Vincenzo; Di Fabrizio, Enzo M.

    2016-01-01

    , such as reproducibility, quantitative analysis and signal background interference. In this work we propose an easy and cheap route, based on a template stripping technique, for producing plasmonic nanostructured films with SERS capabilities. We focus our attention

  10. La ley del rey es la ley de dios: el deber ser de la institucion matrimonial durante la colonia

    Directory of Open Access Journals (Sweden)

    Tatiana Gonzalaez

    2014-02-01

    Full Text Available "La ley del rey es la ley de Dios" aborda el problema aborda el problema del deber ser de la institucion matrimonial que regia las millones de parejas en el Nuevo Mundo hasta mediados del siglo XVIII.

  11. 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.

  12. A SERS protocol as a potential tool to access 6-mercaptopurine release accelerated by glutathione-S-transferase.

    Science.gov (United States)

    Wang, Ying; Sun, Jie; Yang, Qingran; Lu, Wenbo; Li, Yan; Dong, Jian; Qian, Weiping

    2015-11-21

    The developed method for monitoring GST, an important drug metabolic enzyme, could greatly facilitate researches on relative biological fields. In this work, we have developed a SERS technique to monitor the absorbance behaviour of 6-mercaptopurine (6-MP) and its glutathione-S-transferase (GST)-accelerated glutathione (GSH)-triggered release behaviour on the surface of gold nanoflowers (GNFs), using the GNFs as excellent SERS substrates. The SERS signal was used as an indicator of absorbance or release of 6-MP on the gold surface. We found that GST can accelerate GSH-triggered release behaviour of 6-MP from the gold surface. We speculated that GST catalyzes nucleophilic GSH to competitively bind with the electrophilic substance 6-MP. Experimental results have proved that the presented SERS protocol can be utilized as an effective tool for accessing the release of anticancer drugs.

  13. Silver-gold core-shell nanoparticles containing methylene blue as SERS labels for probing and imaging of live cells

    International Nuclear Information System (INIS)

    Guo, X.; Guo, Z.; Jin, Y.; Liu, Z.; Zhang, W.; Huang, D.

    2012-01-01

    We report on silver-gold core-shell nanostructures that contain Methylene Blue (MB) at the gold/x96silver interface. They can be used as reporter molecules in surface-enhanced Raman scattering (SERS) labels. The labels are stable and have strong SERS activity. TEM imaging revealed that these nanoparticles display bright and dark stripe structures. In addition, these labels can act as probes that can be detected and imaged through the specific Raman signatures of the reporters. We show that such SERS probes can identify cellular structures due to enhanced Raman spectra of intrinsic cellular molecules measured in the local optical fields of the core-shell nanostructures. They also provide structural information on the cellular environment as demonstrated for these nanoparticles as new SERS-active and biocompatible substrates for imaging of live cells. (author)

  14. Effect of x-radiation on SERS spectra of chitosan adsorbed on silver nanoparticles with plasmon resonance

    International Nuclear Information System (INIS)

    Motevich, I.G.; Strekal', N.D.; Dul', M.V.; Ganchits, A.T.; Lagun, Yu.Ya.; Melamed, V.D.; Maskevich, S.A.

    2016-01-01

    Chitosan, a deacetylated product of the polysaccharide chitin, is a natural biopolyaminosaccharide obtained from various organisms. Raman and SERS spectra of irradiated and unirradiated chitosan, adsorbed on silver hydrosols, are presented. (authors)

  15. Fabrication of chitosan-silver nanoparticle hybrid 3D porous structure as a SERS substrate for biomedical applications

    Science.gov (United States)

    Jung, Gyeong-Bok; Kim, Ji-Hye; Burm, Jin Sik; Park, Hun-Kuk

    2013-05-01

    We propose a simple, low-cost, large-area, and functional surface enhanced Raman scattering (SERS) substrate for biomedical applications. The SERS substrate with chitosan-silver nanoparticles (chitosan-Ag NPs) hybrid 3D porous structure was fabricated simply by a one-step method. The chitosan was used as a template for the Ag NPs deposition. SERS enhancement by the chitosan-Ag NPs substrate was experimentally verified using rhodamine B as an analyte. Thiolated single stranded DNA was also measured for atopic dermatitis genetic markers (chemokines CCL17) at a low concentration of 5 pM. We successfully designed a novel SERS substrate with silver nanoparticle hybridized 3D porous chitosan that has the potential to become a highly sensitive and selective tool for biomedical applications.

  16. Notas introdutórias sobre a Manualidade do mundo em “ser e tempo” (zuhandenheit

    Directory of Open Access Journals (Sweden)

    Silva, Jayme Camargo da

    2009-01-01

    Full Text Available O filósofo Martin Heidegger explicitou que, a diferença específica entre a existência do homem (Dasein e a dos demais objetos da realidade – aos quais denominou como “Vorhandenheit” (entes intramundanos ou meramente subsistentes -, é que o homem ao existir na compreensão do ser, se autocompreende como ser-no-mundo que é, e assim torna possível a manifestação dos entes subsistentes (circulo hermenêutico. O processo operativo dos modos de ser da existência no cotidiano, se dá através da ocupação (Besorgen e se manifesta no “serem” constitutivo do modo de ser-no-mundo do homem

  17. Subnanomolar Sensitivity of Filter Paper-Based SERS Sensor for Pesticide Detection by Hydrophobicity Change of Paper Surface.

    Science.gov (United States)

    Lee, Minwoo; Oh, Kyudeok; Choi, Han-Kyu; Lee, Sung Gun; Youn, Hye Jung; Lee, Hak Lae; Jeong, Dae Hong

    2018-01-26

    As a cost-effective approach for detecting trace amounts of pesticides, filter paper-based SERS sensors have been the subject of intensive research. One of the hurdles to overcome is the difficulty of retaining nanoparticles on the surface of the paper because of the hydrophilic nature of the cellulose fibers in paper. This reduces the sensitivity and reproducibility of paper-based SERS sensors due to the low density of nanoparticles and short retention time of analytes on the paper surface. In this study, filter paper was treated with alkyl ketene dimer (AKD) to modify its property from hydrophilic to hydrophobic. AKD treatment increased the contact angle of the aqueous silver nanoparticle (AgNP) dispersion, which consequently increased the density of AgNPs. The retention time of the analyte was also increased by preventing its rapid absorption into the filter paper. The SERS signal was strongly enhanced by the increased number of SERS hot spots owing to the increased density of AgNPs on a small contact area of the filter surface. The reproducibility and sensitivity of the SERS signal were optimized by controlling the distribution of AgNPs on the surface of the filter paper by adjusting the concentration of the AgNP solution. Using this SERS sensor with a hydrophobicity-modified filter paper, the spot-to-spot variation of the SERS intensity of 25 spots of 4-aminothiophenol was 6.19%, and the limits of detection of thiram and ferbam as test pesticides were measured to be 0.46 nM and 0.49 nM, respectively. These proof-of-concept results indicate that this paper-based SERS sensor can serve for highly sensitive pesticide detection with low cost and easy fabrication.

  18. 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.

  19. 3D Plasmonic Ensembles of Graphene Oxide and Nobel Metal Nanoparticles with Ultrahigh SERS Activity and Sensitivity

    OpenAIRE

    Jing Lin; Xiansong Wang; Guangxia Shen; Daxiang Cui

    2016-01-01

    We describe a comparison study on 3D ensembles of graphene oxide (GO) and metal nanoparticles (silver nanoparticles (AgNPs), gold nanoparticles (GNPs), and gold nanorods (GNRs)) for surface-enhanced Raman scattering (SERS) application. For the first time, GNRs were successfully assembled on the surfaces of GO by means of electrostatic interactions without adding any surfactant. The SERS properties of GO/AgNPs, GO/GNPs, and GO/GNRs were compared using 2-mercaptopyridine (2-Mpy) as probing mole...

  20. 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.

  1. 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.

    2017-01-01

    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/Ca2+-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. PMID:27998980

  2. 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.

    analysis. Metal-capped silicon nanopillars, fabricated through a maskless ion etch, are state-of-the-art for on-chip SERS substrates. A dense cluster of high aspect ratio polymer nanocones was achieved by using high-throughput polymer injection moulding over a large area replicating a silicon nanopillar...... structure. Gold-capped polymer nanocones display similar SERS sensitivity as silicon nanopillars, while being easily integrable into a microfluidic chips....

  3. Melanin-Associated Synthesis of SERS-Active Nanostructures and the Application for Monitoring of Intracellular Melanogenesis

    OpenAIRE

    Haixin Dong; Zhiming Liu; Huiqing Zhong; Hui Yang; Yan Zhou; Yuqing Hou; Jia Long; Jin Lin; Zhouyi Guo

    2017-01-01

    Melanin plays an indispensable role in the human body. It serves as a biological reducer for the green synthesis of precious metal nanoparticles. Melanin?Ag nanocomposites were successfully produced which exhibited very strong surface-enhanced Raman scattering (SERS) effect because of the reducibility property of melanin. A melanin?Ag composite structure was synthesized in situ in melanin cells, and SERS technique was performed for the rapid imaging and quantitative assay of intracellular mel...

  4. Preparation of sensitive and recyclable porous Ag/TiO{sub 2} composite films for SERS detection

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhengyi; Yu, Jiajie; Yang, Jingying; Lv, Xiang; Wang, Tianhe, E-mail: thwang56@126.com

    2015-12-30

    Graphical abstract: - Highlights: • A new but simple method of fabricating robust TiO{sub 2} films on glass. • AgNPs were deposited on the surface of TiO{sub 2} films with the assistance of UV irradiation. • Substrates with high SERS sensitivity and excellent recyclability. - Abstract: Porous Ag/TiO{sub 2} composite films were prepared by spin coating of titania on normal glass slides and subsequent photochemical deposition of silver nanoparticles (AgNPs). The films were characterized by XRD and FESEM to reveal micro structural and morphological differences between films obtained under varied conditions. The SERS properties of these films were investigated using aqueous crystal violet (CV) as probe molecules. The results indicate that the content of polyethylene glycol (PEG) and photo-reduction time had significant influences on both the microstructure and SERS performance of Ag/TiO{sub 2} films. The highest SERS sensitivity that allowed as low as 10{sup −10} M aqueous CV to be detected, was achieved with the PEG/(C{sub 4}H{sub 9}O){sub 4}Ti molar ratio being 0.08% and with 30 min of UV irradiation. With this film a linear relationship was established through experiment between SERS intensity and CV concentration from 10{sup −10} to 10{sup −5} M, which could be used as a calibration curve for CV concentration measurement. In addition, the film could be reused as a SERS substrate for up to four times without significantly losing SERS sensitivity if a simple regeneration was followed. It is visualized that the Ag/TiO{sub 2} film on glass has potentials for being developed into a practical SERS substrate with high sensitivity and good reusability.

  5. 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.

  6. Highlights from Faraday Discussion FDSERS17: Surface Enhanced Raman Scattering - SERS, Glasgow, UK, 30th August-1st September 2017.

    Science.gov (United States)

    Di Martino, G; Fleming, H; Kamp, M; Lussier, F

    2017-11-28

    The 2017 Faraday Discussion on Surface Enhanced Raman Scattering (SERS) attracted more than a hundred delegates from a broad spectrum of backgrounds and experience levels, bringing together leading scientists involved in the long living field of SERS. The meeting gave an overview of the liveliness of the topic, characterised by open questions and fascinating science still to discover. In the following, we discuss the topics covered during this meeting and briefly highlight the content of each presentation.

  7. 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 dewetting of 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.

  8. Facile fabrication of Ag dendrite-integrated anodic aluminum oxide membrane as effective three-dimensional SERS substrate

    Science.gov (United States)

    Zhang, Cong-yun; Lu, Ya; Zhao, Bin; Hao, Yao-wu; Liu, Ya-qing

    2016-07-01

    A novel surface enhanced Raman scattering (SERS)-active substrate has been successfully developed, where Ag-dendrites are assembled on the surface and embedded in the channels of anodic aluminum oxide (AAO) membrane, via electrodeposition in AgNO3/PVP aqueous system. Reaction conditions were systematically investigated to attain the best Raman enhancement. The growth mechanism of Ag dendritic nanostructures has been proposed. The Ag dendrite-integrated AAO membrane with unique hierarchical structures exhibits high SERS activity for detecting rhodamine 6G with a detection limit as low as 1 × 10-11 M. Furthermore, the three-dimensional (3D) substrates display a good reproducibility with the average intensity variations at the major Raman peak less than 12%. Most importantly, the 3D SERS substrates without any surface modification show an outstanding SERS response for the molecules with weak affinity for noble metal surfaces. The potential application for the detection of polycyclic aromatic hydrocarbons (PAHs) was evaluated with fluoranthene as Raman target molecule and a sensitive SERS detection with a limit down to 10-8 M was reached. The 3D SERS-active substrate shows promising potential for rapid detection of trace organic pollutants even weak affinity molecules in the environment.

  9. Porous Silicon Covered with Silver Nanoparticles as Surface-Enhanced Raman Scattering (SERS) Substrate for Ultra-Low Concentration Detection.

    Science.gov (United States)

    Kosović, Marin; Balarin, Maja; Ivanda, Mile; Đerek, Vedran; Marciuš, Marijan; Ristić, Mira; Gamulin, Ozren

    2015-12-01

    Microporous and macro-mesoporous silicon templates for surface-enhanced Raman scattering (SERS) substrates were produced by anodization of low doped p-type silicon wafers. By immersion plating in AgNO3, the templates were covered with silver metallic film consisting of different silver nanostructures. Scanning electron microscopy (SEM) micrographs of these SERS substrates showed diverse morphology with significant difference in an average size and size distribution of silver nanoparticles. Ultraviolet-visible-near-infrared (UV-Vis-NIR) reflection spectroscopy showed plasmonic absorption at 398 and 469 nm, which is in accordance with the SEM findings. The activity of the SERS substrates was tested using rhodamine 6G (R6G) dye molecules and 514.5 nm laser excitation. Contrary to the microporous silicon template, the SERS substrate prepared from macro-mesoporous silicon template showed significantly broader size distribution of irregular silver nanoparticles as well as localized surface plasmon resonance closer to excitation laser wavelength. Such silver morphology has high SERS sensitivity that enables ultralow concentration detection of R6G dye molecules up to 10(-15) M. To our knowledge, this is the lowest concentration detected of R6G dye molecules on porous silicon-based SERS substrates, which might even indicate possible single molecule detection.

  10. 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

  11. 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

  12. 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

  13. 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).

  14. MODOS DE SER JOVEM NA ESCOLA: um estudo de caso etnográfico

    Directory of Open Access Journals (Sweden)

    Livian Lino Netto

    2016-08-01

    Full Text Available O artigo apresenta um recorte de pesquisa realizada com estudantes do Instituto Federal Sul-rio-grandense, que teve por objetivo descrever imagens da juventude com foco na percepção que os jovens têm sobre si mesmos na escola. A partir de princípios qualitativos, o estudo caracterizou-se como estudo de caso de inspiração etnográfica. A coleta foi realizada através da filmagem de documentários pelos estudantes sobre o que é ser jovem na escola e qual o sentido da mesma em suas vidas. Como resultado, afirma-se que o principal sentido atribuído pelos jovens à escola é o estar junto com o outro.

  15. SERS spectrum of gallic acid obtained from a modified silver colloid

    Science.gov (United States)

    Garrido, C.; Diaz-Fleming, G.; Campos-Vallette, M. M.

    2016-06-01

    Two different crystals of the gallic acid were microscopically separated from a p.a. commercial product. The Raman spectra analysis allowed distinguishing monomeric and dimeric structures. The vibrational wave numbers were computed using DFT quantum chemical calculations. The data obtained from wave number calculations are used to assign vibrational bands obtained in the Raman spectrum. The dimer, characterized as ellagic acid, involves the carboxyl and hydroxyl moieties. The Raman spectrum in water solution of each species is dominated by the monomeric form. A low negatively charged Ag colloid allowed obtain to the best of our knowledge, the first surface enhanced Raman scattering (SERS) spectrum of the gallic acid. The possible electrophilic attacking sites of the title molecule are identified using MEP surface plot study and the orientation of the analyte on the metal surface is proposed tilted to the surface.

  16. 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...

  17. 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.

  18. Ecofriendly Synthesis of Anisotropic Gold Nanoparticles: A Potential Candidate of SERS Studies

    Directory of Open Access Journals (Sweden)

    Ujjwala Gaware

    2012-01-01

    Full Text Available Ecofriendly synthesis of nanoparticles has been inspiring to nanotechnologists especially for biomedical applications. Moreover, anisotropic particle synthesis is an attractive option due to decreased symmetry of such particles often leads to new and unusual chemical and physical behaviour. This paper reports a single-step room-temperature synthesis of gold nanotriangles using a cheap bioresource of reducing and stabilizing agent Piper betle leaf extract. On treating aqueous chloroauric acid solution with Piper betle leaf extract, after 12 hr, complete reduction of the chloroaurate ions was observed leading to the formation of flat and single crystalline gold nanotriangles. These gold nanotriangles can be exploited in photonics, optical coating, optoelectronics, magnetism, catalysis, chemical sensing, and so forth, and are a potential candidate of SERS studies.

  19. 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.

  20. Electron microscopy localization and characterization of functionalized composite organic-inorganic SERS nanoparticles on leukemia cells.

    Science.gov (United States)

    Koh, Ai Leen; Shachaf, Catherine M; Elchuri, Sailaja; Nolan, Garry P; Sinclair, Robert

    2008-12-01

    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.

  1. 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.

  2. 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.

  3. 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

    2014-03-01

    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.

  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. [Conformation analysis of the N-glycosylation site Asn-X-Thr/Ser in glycoproteins].

    Science.gov (United States)

    Avanov, A Ia; Lipkind, G M

    1990-03-01

    Theoretical conformational analysis of oligopeptides CH3CO-Asn-X-Thr-NHCH3 (X = Gly, Ala, Pro), modelling N-glycosylation site, and their glycosylated derivatives CH3CO-(GlcNAc beta 1-4GlcNAc beta 1) Asn-X-Thr-NHCH3 has been carried out. Active conformations of the site are found, corresponding to structural prerequisities of N-glycosylation: Asn residue's position in beta-turn and hydrogen bond formation between side chains of Asn and Thr/Ser residues. In this case the L conformation of the central residue X is most probable. Since Pro residue does not possess this conformation, sequences with X = Pro are not glycosylated. It is shown that glycosylation of the above-mentioned sites is accompanied by reorientation of the Asn residue's side chains.

  6. Del deber ser de la acción política

    Directory of Open Access Journals (Sweden)

    Ángel Emilio Muñoz Cardona

    2007-04-01

    Full Text Available En los Estados democráticos modernos la política se distingue como el conjunto de acciones encaminadas a conquistar y preservar el poder supremo de la soberanía. Poder soberano que se encuentra y radica en la sociedad, la cual, a través de su accionar define las leyes e instituciones para ser defendida y gobernada. De esta manera, si bien el Estado puede implementar medidas que afecten a la sociedad en su conjunto, también es cierto que él mismo se encuentra regulado por la sociedad que lo conforma, es decir, por los procesos normativos y sociales que lo delimitan en su acción. Finalmente, es la sociedad que con su sentir y con su obrar forja el gobierno que desea o merece.

  7. Marine Longilenes, Oxasqualenoids with Ser-Thr Protein Phosphatase 2A Inhibition Activity

    Directory of Open Access Journals (Sweden)

    Francisco Cen-Pacheco

    2018-04-01

    Full Text Available The red seaweed Laurencia viridis is a rich source of oxygenated secondary metabolites that were derived from squalene. We report here the structures of three novel compounds, (+-longilene peroxide (1, longilene (2, and (+-prelongilene (3 that were isolated from this alga, in addition to other substances, 4 and 5, resulting from their acid-mediated degradation. The effect of compounds 1 and 3 against Ser-Thr protein phosphatase type 2A (PP2A was evaluated, showing that (+-longilene peroxide (1 inhibited PP2A (IC50 11.3 μM. In order to explain the interaction between PP2A and compounds 1 and 3, molecular docking simulations onto the PP2A enzyme-binding region were used.

  8. 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...

  9. 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.

  10. Vivências da mulher a ser mastectomizada: esclarecimentos e orientações

    Directory of Open Access Journals (Sweden)

    Jaqueline Ferreira Ventura Bittencourt

    2002-08-01

    Full Text Available Com vistas a compreender o significado que a mulher com câncer de mama atribui ao vir-a-ser-mastectomizada, fundamentei-me na abordagem fenomenológica. A análise compreensiva dos depoimentos de sete mulheres, desvelou que a carência do cuidar se insere no mundo-vida dessas mulheres, sobressaindo principalmente a carência das informações negadas, ou seja, na falta de esclarecimento e orientação, O estudo aponta para o enfoque de um cuidado, que busque contemplar a integralidade da mulher, em seus aspectos físicos, como também em seus aspectos emocionais, sociais e sobretudo no envolvimento da equipe multidisciplinar.

  11. Phosphorylation of dynamin I on Ser-795 by protein kinase C blocks its association with phospholipids

    DEFF Research Database (Denmark)

    Powell, K A; Valova, V A; Malladi, C S

    2000-01-01

    Dynamin I is phosphorylated in nerve terminals exclusively in the cytosolic compartment and in vitro by protein kinase C (PKC). Dephosphorylation is required for synaptic vesicle retrieval, suggesting that its phosphorylation affects its subcellular localization. An in vitro phospholipid binding ...... assay was established that prevents lipid vesiculation and dynamin lipid insertion into the lipid. Dynamin I bound the phospholipid in a concentration-dependent and saturable manner, with an apparent affinity of 230 +/- 51 nM. Optimal binding occurred with mixtures of phosphatidylserine...... the phosphorylation site in PKCalpha-phosphorylated dynamin I as a single site at Ser-795, located near a binding site for the SH3 domain of p85, the regulatory subunit of phosphatidylinositol 3-kinase. However, phosphorylation had no effect on dynamin binding to a bacterially expressed p85-SH3 domain. Thus...

  12. 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

    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...... 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...

  13. 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.

  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. Monomer functionalized silica coated with Ag nanoparticles for enhanced SERS hotspots

    Science.gov (United States)

    Newmai, M. Boazbou; Verma, Manoj; Kumar, P. Senthil

    2018-05-01

    Mesoporous silica (SiO2) spheres are well-known for their excellent chromatographic properties such as the relatively high specific surface, large pore volume, uniform particle size, narrow pore size distribution with favorable pore connectivity; whereas the noble metal Ag nanoparticles have unique size/shape dependant surface plasmon resonance with wide ranging applications. Thus, the desire to synchronize both their properties for specific applications has naturally prompted research in the design and synthesis of core-shell type novel nanoAg@mesoSiO2 nanocomposites, which display potential utility in applications such as photothermal therapy, photocatalysis, molecular sensing, and photovoltaics. In the present work, SiO2 spheres were carefully functionalized with the monomer, N-vinyl pyrrolidone (NVP), which cohesively controls the uniform mass transfer of Ag+ metal ions, thereby enabling its sequential reduction to zerovalent Ag (in the presence of slightly excess NaOH) by electron transfer from nucleophilic attack of the NVP vinyl group by the water molecules even under ambient conditions. Complete metal nanoshell coverage of the silica surface was obtained after multiple Ag deposition cycles, as systematically confirmed from the BET, TEM, optical and FTIR characterization. Our present Ag-coated silica spheres were directly utilized as viable SERS substrates with high sensitivity in contrast with other long chain polymer/surfactant coated silica spheres, owing to the presence of significant number of nanogaps enhanced SERS 'hotspots', which were methodically analyzed utilizing two example analytes, such as crystal violet (CV) and calendula officinalis (CaF).

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.