Estudio por métodos espectroscópicos de la interacción de aminoácidos y homopéptidos con componentes cristalinos de cálculos renales

Tesis Univ. Complutense de Madrid.ProQuestFac. de Ciencias QuímicasTRUEpu

Near-field electromagnetic wave scattering from random self-affine fractal metal surfaces: Spectral dependence of local field enhancements and their statistics in connection with surface-enhanced Raman scattering

11 págs.; 10 figs.By means of rigorous numerical simulation calculations based on the Green's theorem integral equation formulation, we study the near electromagnetic field in the vicinity of very rough, one-dimensional self-affine fractal surfaces of Ag, Au, and Cu (for both vacuum and water propagating media) illuminated by a p-polarized field. Strongly localized enhanced optical excitations (hot spots) are found, with electric field intensity enhancements of close to 4 orders of magnitude and widths below a tenth of the incoming wavelength. These effects are produced by the roughness-induced surface-plasmon polariton excitation. We study the characteristics of these optical excitations as well as other properties of the surface electromagnetic field, such as its statistics (probability density function, average, and fluctuations), and their dependence on the excitation spectrum (in the visible and near-infrared regions). Our study is relevant to the use of self-affine fractals as surface-enhanced Raman scattering substrates, where large local and average field enhancements are desired. ©2000 American Physical SocietyThis work was supported by the Spanish Dirección General de Ensenñanza Superior e Investigación Científica y Técnica, through Grant No. PB97-1221. We also thank the Mexican-Spanish CONACYT-CSIC program for partial travel support.Peer Reviewe

Hollow Au/Ag nanostars displaying broad plasmonic resonance and high surface-enhanced Raman sensitivity

9 pas.; 7 figs.; 2 tabs.This journal is © The Royal Society of Chemistry. Bimetallic Au/Ag hollow nanostar (HNS) nanoparticles with different morphologies were prepared in this work. These nanoplatforms were obtained by changing the experimental conditions (concentration of silver and chemical reductors, hydroxylamine and citrate) and by using Ag nanostars as template nanoparticles (NPs) through galvanic replacement. The goal of this research was to create bimetallic Au/Ag star-shaped nanoparticles with advanced properties displaying a broader plasmonic resonance, a cleaner exposed surface, and a high concentration of electromagnetic hot spots on the surface provided by the special morphology of nanostars. The size, shape, and composition of Ag as well as their optical properties were studied by extinction spectroscopy, hyperspectral dark field microscopy, transmission and scanning electron microscopy (TEM and SEM), and energy dispersive X-ray spectroscopy (EDX). Finally, the surface-enhanced Raman scattering (SERS) activity of these HNS was investigated by using thioflavin T, a biomarker of the β-amyloid fibril formation, responsible for Alzheimer's disease. Lucigenin, a molecule displaying different SERS activities on Au and Ag, was also used to explore the presence of these metals on the NP surface. Thus, a relationship between the morphology, plasmon resonance and SERS activity of these new NPs was made.This work has been supported by the Spanish Ministerio de Economía y Competitividad (MINECO, grant FIS2014-52212- R). A. G.-L. acknowledges CSIC and FSE 2007–2013 for a JAE-CSIC predoctoral grant.Peer Reviewe

Collective electromagnetic emission from molecular layers on metal nanostructures mediated by surface plasmons

6 págs.; 3 figs.; PACS number s : 73.20.Mf, 78.30. j, 78.67.Bf, 42.25.FxCollective electromagnetic processes stemming from molecular emission close to complex nanostructured metal surfaces pumped at and/or near surface-plasmon resonances are theoretically investigated. A classical electrodynamics model is used to describe macroscopically the surface molecular layer emission. Generalized Fresnel coefficients are analytically obtained for planar surfaces, indeed predicting collective quenching for redshifted emission at given angles. The model is introduced into a scattering formulation based on surface integral equations in order to explore collective spontaneous emission near metallic nanoantennas and surface-enhanced Raman scattering. Frequency-shifted near-field patterns and properly defined enhancement factors are obtained that manifest collective processes and cannot be simply inferred from calculations of near fields at the pump frequency. © 2007 The American Physical Society.This work was supported in part by the Spanish “Ministerio de Educación y Ciencia” Grant Nos. FIS2006-07894 and FIS2004-0108 and “Comunidad de Madrid” Grant No. S-0505/TIC-0191 and V.G.’s Ph.D. scholarshipPeer Reviewe

Diseño de un procedimiento de actuación en accidentes de turismo activo

[ES] ElTurismo activo ha venido siendo un sector empresarial en auge y desarrollo en el territorio español, con una gran diversidad de normativas existentes en base a las competencias que recaen en las Comunidades Autónomas. El riesgo inherente a estas prácticas deportivas en el medio natural conlleva la exposición de los participantes a la posibilidad de sufrir un accidente. Ante la inexistencia de un Procedimiento de Actuación ante accidentes en actividades de Turismo activo, se ha desarrollado una herramienta de aplicación a todas las actividades del sector, a partir de los aspectos a valorar por parte del guía de Turismo activo, la cual establece cinco fases desde que se produce el accidente hasta el finde la actividad. Para ello se ha realizado una revisión bibliográfica y la consulta a un grupo de expertos vinculados a la prevención de riesgos, rescate, organización y guiado de actividades en el medio natural y el Turismo activo. La herramienta propuesta aporta unas pautas de actuación seguras en caso de accidente, para los guías de Turismo activo, en base a la normativa vigente y las características propias de las actividades que realizan, con el fin de asegurar una correcta actuación para subsanar o evitar el agravio de las lesiones padecidas y/o facilitar el rescate y evacuación de la persona accidentada[EN] ActiveTourism has been a developing business sector in the Spanish territory.There are a great diversity of different regulations and legislation for each Autonomous Community. The practice of physical activity in the natural environment entails the exposure of the athletes to the possibility of suffering an accident. In the absence of an Action Procedure for accidents in active tourism activities, an application tool has been developed for all activities in the sector. It has been based on the aspects to be assessed by the Active Tourism guide.The tool stablishes five steps to follow, from the accident until the end of the activity.A bibliographic review and consultation with a group of experts has been carried out.The group of experts were linked to risk prevention, rescue, organization, and guide of activities in the natural environment and active tourism. The proposed procedure provides guidelines for safe action in the event of an accident, for ActiveTourism guides, based on current regulations and the characteristics of the activities they carry out, to ensure correct action to correct, or avoid, the grievance of the injuries suffered and / or facilitate the rescue and evacuation of the injured personN

Solution SERS of an insoluble synthetic organic pigment-quinacridone quinone-employing calixarenes as dispersive cavitands

3 páginas, 5 figuras.A possibility of getting SERS spectra of insoluble aromatic compounds in colloidal silver solutions is described. The method tested for the organic pigment quinacridone quinone consists of dispersing it in calix[n]arenes. The potentials of such cavitands, both as dispersing and as silver functionalization agents, is reported as a function of the substitution in their lower rim and their cavity size.This work has been financially supported by the Ministerio de Ciencia e Innovacio´n of Spain (Projects FIS2007-63065 and CONSOLIDER CSD2007-0058/TCP) and the Comunidad de Madrid (MICROSERES II Project S2009/TIC1476).Peer reviewe

Caracterización molecular de nanoportadores de fármacos mediante espectroscopía intensificada por plasmones localizados: Fluorescencia (SEF) y Raman (SERS)

The combined application of SERS (Surface-Enhanced Raman Scattering) and SEF (Surface Enhanced Fluorescence) to the molecular characterization of druǵs nanocarriers based on silver colloids is here shown for the antitumoral drug emodin, and the Non-Steroidal Anti-Inflammatory Drugs indomethacin and ketorolac. The system >silver nanoparticles-emodin> was subsequently embedded in porous silicon and the new system also characterized. The joint analysis of the SERS, SEF and UV-Vis spectra of indomethacin and ketorolac at different pHs has also allowed to propose schemes for the approaching mechanisms of the drug molecules to the silver nanoparticles surface in the pH range studied.© Sociedad Española de Óptica.Se agradece al MINECO (proyecto FIS2010-15405), a la Comunidad de Madrid (proyecto MICROSERES II-S 2009TIC-1476) y al Grupo Investigación 950247 de la UCM, la financiación recibida para llevar a cabo este trabajo.Peer Reviewe

Noble metal nanoparticles used as carriers systems for NSAIDs drugs: SEF, release and binding

Peer Reviewe