150 research outputs found

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

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    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)

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    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

    Surface enhanced fluorescence of anti-tumoral drug emodin adsorbed on silver nanoparticles and loaded on porous silicon

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    Fluorescence spectra of anti-tumoral drug emodin loaded on nanostructured porous silicon have been recorded. The use of colloidal nanoparticles allowed embedding of the drug without previous porous silicon functionalization and leads to the observation of an enhancement of fluorescence of the drug. Mean pore size of porous silicon matrices was 60 nm, while silver nanoparticles mean diameter was 50 nm. Atmospheric and vacuum conditions at room temperature were used to infiltrate emodin-silver nanoparticles complexes into porous silicon matrices. The drug was loaded after adsorption on metal surface, alone, and bound to bovine serum albumin. Methanol and water were used as solvents. Spectra with 1 μm spatial resolution of cross-section of porous silicon layers were recorded to observe the penetration of the drug. A maximum fluorescence enhancement factor of 24 was obtained when protein was loaded bound to albumin, and atmospheric conditions of inclusion were used. A better penetration was obtained using methanol as solvent when comparing with water. Complexes of emodin remain loaded for 30 days after preparation without an apparent degradation of the drug, although a decrease in the enhancement factor is observed. The study reported here constitutes the basis for designing a new drug delivery system with future applications in medicine and pharmacyThe Secretaria de Estado de Investigacion, Desarrollo e Innovacion (MINECO) (Project FIS2010-15405: Plasmonics: Enhanced Molecular Sensing on Metal Nanostructures (POEMS), Comunidad de Madrid (MICROSERES Project, S2009TIC-1476) and grupo investigación 950247 of the UCM are gratefully acknowledged for their financial support. David Gomez (characterization service from the ICTP-CSIC) is also acknowledged for the FE-SEM image

    Aplicaciones de la espectroscopía SERS (Surface-Enhanced Raman Scattering) a la detección de pigmentos orgánicos naturales en objetos del Patrimonio Cultural

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    16 páginas, 17 figuras.La espectroscopía Raman, cuyas prestaciones se han visto considerablemente mejoradas en los últimos 15 años debido a la introducción de técnicas de microscopía (que han sido posibles gracias a importantes avances tecnológicos en filtros ópticos y detectores de alta sensibilidad), se ha convertido en una técnica de identificación molecular de gran utilidad en el campo del Patrimonio Cultural [1]. Al igual que la más conocida espectroscopía Infrarroja, la espectroscopía Raman proporciona información sobre los compuestos moleculares presentes en la muestra bajo estudio, ampliando por ello la información acerca de la presencia de elementos químicos que suministran otras técnicas espectroscópicas tales como XRF, SEM - EDX, PIXE y LIBS utilizadas habitualmente en el análisis de objetos artísticos [2]. Hoy en día podemos encontrar la técnica de microscopía Raman en los departamentos de Conservación y Restauración de los más importantes Museos y Bibliotecas de todo el mundo, utilizándose como técnica no destructiva (incluso in situ) para diagnóstico de diferentes materiales que van desde los pigmentos inorgánicos hasta los biomateriales, en objetos artísticos tan diferentes como manuscritos, pinturas, textiles, cerámicas, vidrios, esculturas, monumentos, e incluso momias o cañones hundidos. La información que se obtiene puede resultar decisiva para la datación y autenticación de las obras artísticas, y ayuda a determinar los cambios físicos y/o químicos que han contribuido a su deterioro a través de la identificación de los productos de degradación de los materiales originales.Agradecemos al MICINN (Proyectos FIS2007-63065 y CONSOLIDER CSD 2007- 0058) y a la Comunidad de Madrid (MICROSERES, S2009TIC-1476) por la financiación parcial de los trabajos aquí expuestos. Agradecemos también el apoyo recibido de la Red Temática de Patrimonio Histórico y Cultural (CSIC). MVC y EdP agradecen al CSIC y al FSE 2007-2013 la concesión de sus respectivos Contratos post- y predoctoral.Peer reviewe

    In situ assessment of carbon nanotube diameter distribution with photoelectron spectroscopy

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    7 págs.; 6 figs.; 1 tab. ; PACS numberssd: 73.22.2f, 79.60.Jv, 61.46.1wIn situ UV-photoelectron spectroscopy (He I and He II) was performed on multiwalled carbon nanotubes (CNTs) with clearly differentiated diameter distributions. A significant dependence of valence- and conduction-band characteristics on the mean CNT diameter was observed, which was determined by high-resolution TEM and micro-Raman spectroscopy. The decrease of relative intensity of the π states at -3 eV in the He II experiments, indicative of increasing rehybridization between orbitals, was directly correlated with decreasing mean diameters. Furthermore, a progressive broadening of the unoccupied σ* band at 7.6 eV was found in the He I spectra. © 2005 The American Physical Society.J.W.S. is grateful to the Centre Interdisciplinaire de Microscopie Electronique sCIMEd at the Ecole Polytechnique Fédérale de Lausanne sEPFLd for access to TEM and technical support. We also thank the National Centre of Competence in Research for Nanosciences NCCRd and the Swiss National Foundation for financial support.Peer Reviewe

    Clima e incendios forestales en Cantabria: evolución y tendencias recientes

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    Los incendios son un fenómeno frecuente en Cantabria, pero su estacionalidad no se corresponde con el típico máximo estival característico del resto de España. La mayoría se concentran a fines del invierno y comienzos de la primavera y su origen son unas prácticas ganaderas (principalmente la quema de matorral para mantenimiento de pastos) que aprovechan las favorables condiciones atmosféricas originadas por un tipo de temporal de viento conocido localmente como ?surada?. En este artículo se analizan las tendencias de algunas variables climáticas, desde 1961, durante el periodo de máximo riesgo de incendios para determinar en qué medida la aparición de incendios forestales ha estado condicionada por la evolución climática reciente. Los resultados muestran que el clima regional ha experimentado un calentamiento y un desecamiento, debido al efecto combinado del incremento de la temperatura y de la reducción de humedad relativa y precipitación, variables que juegan un papel determinante en la aparición de este fenómeno. Sin embargo, la frecuencia de ?suradas? ha disminuido. Esta evolución climática regional está estrechamente vinculada con la evolución de la circulación atmosférica a escala sinóptica y hemisférica; la mayor frecuencia de células anticiclónicas sobre la Península Ibérica a fines del invierno y comienzo de la primavera, y la reducción del número de perturbaciones atlánticas concuerdan en gran medida con la evolución de la Oscilación del Atlántico Norte.Wildfires are a frequent event in Cantabria, but their seasonality does not match the typical warm season maximum generalized in most of the Iberian Peninsula. They occur at the end of the winter and the beginning of the spring (January to March), being mostly anthropogenically triggered, in conjunction with "Suradas", a windstorm which combines high winds and low humidity. In this contribution temporal trends of several climatic variables from meteorological observatories located in Cantabria and nearby regions are analyzed since 1961 during the highest risk period in order to assess to what extent the occurrence of wildfires may be linked to the recent climatic variability. Our results show that the regional climate has become warmer and drier, due to the combined effects of increases in temperatures and the decrease in relative humidity and precipitation, variables that are likely to play an important role in drought and fire proneness. However, the exception is the frequency of “Suradas”, which have reduced. Those regional climatic trends are strongly linked to the recent evolution of atmospheric circulation at regional and hemispheric scale. The higher frequency of anticyclonic cells over the Iberian Peninsula, and conversely, the reduction of the number of Atlantic baroclinic disturbances are consistent with the temporal evolution of the North Atlantic Oscillation

    Facile, fast and green synthesis of a highly porous calcium-syringate bioMOF with intriguing triple bioactivity

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    A facile, fast and green strategy based on ethanol is utilized to prepare a new bioMOF, namely, CaSyr-1, with particular characteristics of full biocompatibility given by using just calcium and syringic acid, the latter being a phenolic natural product found in fruits and vegetables, permanent porosity with an outstanding surface area >1000 m2 g−1, and a micropore diameter of 1.4 nm close to mesopore values. Collectively, these data establish CaSyr-1 as one of the most porous bioMOFs reported to date, with high molecular adsorption capacity. The CaSyr-1 adsorptive behavior is revised here through the reversible adsorption of CO2 and the encapsulation of bioactive ingredients in the structure. Remarkably, CaSyr-1 enables the development of triple therapeutic entities, involving bioactive Ca2+, syringic acid and an impregnated drug

    Comparative evaluation of Panbio and SD Biosensor antigen rapid diagnostic tests for COVID-19 diagnosis

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    The aim of our study was to evaluate the diagnostic performance of two antigen rapid diagnostic tests (Ag‐RDTs) to diagnose severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection. We evaluated Panbio and SD‐Biosensor Ag‐RDTs. We employed 186 polymerase chain reaction (PCR) negative samples to evaluate the specificity and 170 PCR positive samples to assess the sensitivity. We evaluated their sensitivity according to Cycle threshold (Ct) values and days post onset of symptoms (d.p.o.). Tests were compared using the McNemar's test. Agreement was evaluated using the kappa score. Specificity was 100% for Panbio and 97.3% for SD‐Biosensor. Sensitivity for samples with Ct ≤ 20 was 100% for both assays and for samples with Ct = 20–25 was 93.0% (Panbio) and 95.3% (SD‐Biosensor) (p = 1.000). Sensitivity decreased for samples wit Ct = 25–30 (Panbio: 41.3%, SD‐Biosensor: 52.2%, p = 0.125) and samples with Ct ≥ 30 (Panbio: 5.0%, SD‐Biosensor: 17.5%, p = 0.063). Sensitivity within seven d.p.o. was 87.7% for Panbio and 90.4% for SD‐Biosensor and notably decreased after seven d.p.o. Agreement with PCR was excellent for high viral load samples (Ct ≤ 25): Panbio, 98.9%, kappa = 0.974; SD‐Biosensor, 97.4%, kappa = 0.940. Agreement between Ag‐RDTs was excellent (94.9%, kappa = 0.882). Panbio and SD‐Biosensor Ag‐RDTs showed excellent agreement and diagnostic performance results for samples with high viral loads (Ct ≤ 25) or samples within seven d.p.o

    Opinions and perceptions of patients with cardiovascular disease on adherence: a qualitative study of focus groups

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    Background Cardiovascular diseases are becoming more frequent throughout the world. Adherence to both pharmacological and non-pharmacological treatment, as well as lifestyles, is important for good management and control of the disease. This study aims to explore the opinions and perceptions of patients with ischemic heart disease on the difculties associated with therapeutic adherence. Methods An interpretive phenomenological study was carried out using focus groups and one semi-structured interview. The MAXQDA qualitative data analysis program was used for inductive interpretation of the group discourses and interview. Data were coded, and these were grouped by categories and then consolidated under the main themes identifed. Results Two in-person focus groups and one remote semi-structured interview were performed. Twelve participants (6 men and 6 women) from the Hospital de San Juan de Alicante participated, two of them being family companions. The main themes identifed were aspects related to the individual, heart disease, drug treatment, and the perception of the health care system. Conclusions Adhering to recommendations on healthy behaviors and taking prescribed medications for cardiovascular disease was important for most participants. However, they sometimes found polypharmacy difcult to manage, especially when they did not perceive the symptoms of their disease. Participants related the concept of fear to therapeutic adherence, believing that the latter increased with the former. The relationship with health professionals was described as optimal, but, nevertheless, the coordination of the health care system was seen as limited.This study was funded by the Spanish Ministry of Science and Innovation (MICINN) and Carlos III Health Institute (ISCIII)/European Regional Development Fund (ERDF), (RICAPPS: RD21/0016/0024). The authors acknowledge support from the Health Research Projects—Strategic Action in Health (Reference: PI20/01304) of the SpanishFondo de Investigación Sanitaria—Instituto de Salud Carlos III, co-funded by the European Regional Development Fund/European Social Fund: A way to make Europe/Investing in Your Future
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