62 research outputs found

    Silver nanoparticle chains for ultra-long-range plasmonic waveguides for Nd3+ fluorescence

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    Plasmonic waveguides have been shown to be a promising approach to confine and transport electromagnetic energy beyond the diffraction limit. However, ohmic losses generally prevent their integration at micrometric or millimetric scales. Here, we present a gain-compensated plasmonic waveguide based on the integration of linear chains of Ag nanoparticles on an optically active Nd3+-doped solid-state gain medium. By means of dual confocal fluorescence microscopy, we demonstrate long-range optical energy propagation due to the near-field coupling between the plasmonic nanostructures and the Nd3+ ions. The subwavelength fluorescence guiding is monitored at distances of around 100 µm from the excitation source for two different emission ranges centered at around 900 nm and 1080 nm. In both cases, the guided fluorescence exhibits a strong polarization dependence, consistent with the polarization behavior of the plasmon resonance supported by the chain. The experimental results are interpreted through numerical simulations in quasi-infinite long chains, which corroborate the propagation features of the Ag nanoparticle chains at both excitation (λexc = 590 nm) and emission wavelengths. The obtained results exceed by an order of magnitude that of previous reports on electromagnetic energy transport using linear plasmonic chains. The work points out the potential of combining Ag nanoparticle chains with a small interparticle distance (~2 nm) with rare-earth-based optical gain media as ultra-long-range waveguides with extreme light confinement. The results offer new perspectives for the design of integrated hybrid plasmonic–photonic circuits based on rare-earth-activated solid-state platformsThis research has been funded by the Spanish State Research Agency under contracts PID2019-108257GB-I00 and RTI2018-098452-B-100, Comunidad de Madrid under contract CAM (SI1/PJI/2019-00105) and the María de Maeztu “Programme for Units of Excellence in R&D” CEX2018-000805-

    CosmoHub : Interactive exploration and distribution of astronomical data on Hadoop

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    We present CosmoHub (https://cosmohub.pic.es), a web application based on Hadoop to perform interactive exploration and distribution of massive cosmological datasets. Recent Cosmology seeks to unveil the nature of both dark matter and dark energy mapping the large-scale structure of the Universe, through the analysis of massive amounts of astronomical data, progressively increasing during the last (and future) decades with the digitization and automation of the experimental techniques. CosmoHub, hosted and developed at the Port d'Informacio Científica (PIC), provides support to a worldwide community of scientists, without requiring the end user to know any Structured Query Language (SQL). It is serving data of several large international collaborations such as the Euclid space mission, the Dark Energy Survey (DES), the Physics of the Accelerating Universe Survey (PAUS) and the Marenostrum Institut de Ciencies de l'Espai (MICE) numerical simulations. While originally developed as a PostgreSQL relational database web frontend, this work describes the current version of CosmoHub, built on top of Apache Hive, which facilitates scalable reading, writing and managing huge datasets. As CosmoHub's datasets are seldomly modified, Hive it is a better fit. Over 60 TiB of catalogued information and 50 × 109 astronomical objects can be interactively explored using an integrated visualization tool which includes 1D histogram and 2D heatmap plots. In our current implementation, online exploration of datasets of 109 objects can be done in a timescale of tens of seconds. Users can also download customized subsets of data in standard formats generated in few minutes

    SARS-CoV-2 RNAemia is associated with severe chronic underlying diseases but not with nasopharyngeal viral load

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    Supported by Plan Nacional de I + D + i 2013–2016 and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Economía, Industria y Competitividad, Spanish Network for Research in Infectious Diseases (REIPI, RD16/0016/0001, RD16/0016/0005, RD16/0016/0007, RD16/0016/0009, RD16/0016/0010, R D16/0016/0013) cofinanced by European Development Regional Fund “A way to achieve Europe”, Operative program Intelligent Growth 2014–2020. JSC and EC received grants from the Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación, Proyectos de Investigación sobre el SARSCoV-2 y la enfermedad COVID-19 ( COV20/00580 ; COV20/00370 ). J.S.C. is a researcher belonging to the program “Nicolás Monardes” (C-0059–2018), Servicio Andaluz de Salud, Junta de Andalucía, Spain

    Impact of SARS-CoV-2 RNAemia and other risk factors on long-COVID: A prospective observational multicentre cohort study

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    As the COVID-19 pandemic has progressed, long-COVID has emerged as a major problem that poses a significant challenge for attending physicians and health care policy makers. Therefore, we read with much interest the recently published unicentre study in the Journal of Infection by Righi et al.,1 carried out on 465 adult COVID-19 patients (235 [50.5%] hospital-admitted) followed-up during nine months, concluding that those with advanced age, intensive care unit (ICU) admission, and multiple symptoms at onset were more likely to have long-term COVID-19 symptoms, with negative impact on physical and mental wellbeing. Other studies have found that female gender, age, longer hospital stay, pre-existing hypertension, cardiovascular disease, diabetes, chronic obstructive pulmonary disease, smoking, obesity, and chronic alcoholism increase the likelihood of long-COVID.2,3 It is known that SARS-CoV-2 RNAemia is a predictor of COVID-19 severity and in-hospital complications.4,5 However, to the best of our knowledge, only two studies have assessed, up to one or three months after the acute COVID-19 onset, whether SARS-CoV-2 RNAemia may have an impact on long-COVID,6,7 both finding that RNAemia at presentation might predict the persistence of symptoms. However, these studies did not provide information regarding long-COVID symptoms nor the association with SARS-CoV-2 RNAemia beyond three months, and could not differentiate between “true” long-COVID and the convalescence phase of the SARS-CoV-2 infection.A.R. has received a predoctoral research grant from the Instituto de Salud Carlos III, Spanish Ministry of Science, Innovation and Universities, (PFIS grant FI18/00183). G.A.A. reports a predoctoral research grant from the 201808-10 project, funded by La Marató de TV3. This study was supported by the Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Economía, Industria y Competitividad, the Spanish Network for Research in Infectious Diseases (REIPI, RD16/0016/0001, RD16/0016/0005, RD16/0016/0009, RD16/0016/0013)-co-financed by the European Development Regional Fund, A way to achieve Europe, Operative program Intelligent Growth 2014-2020, and the Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC) [CB21/13/00009; CB21/13/00006], Madrid, Spain. J.S.C. and E.C. received grants from the Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación, Proyectos de Investigación sobre el SARS-CoV-2 y la enfermedad COVID-19 (COV20/00580; COV20/00370). J.S.C. is a researcher belonging to the program “Nicolás Monardes” (C-0059–2018), Servicio Andaluz de Salud, Junta de Andalucía, Spain. Samples and data from patients included in this study from the Hospital Universitario Cruces (Bizkaia, Spain) were provided by the Basque Biobank (www.biobancovasco.org) and were processed following standard operation procedures with appropriate approval of the Ethical and Scientific Committees.Peer reviewe

    The Phoenix stream : a cold stream in the southern hemisphere

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    We report the discovery of a stellar stream in the Dark Energy Survey Year 1 (Y1A1) data. The discovery was made through simple color–magnitude filters and visual inspection of the Y1A1 data. We refer to this new object as the Phoenix stream, after its resident constellation. After subtraction of the background stellar population we detect a clear signal of a simple stellar population. By fitting the ridge line of the stream in color–magnitude space, we find that a stellar population with age τ=11.5±0.5 Gyr and [Fe/H]<−1.6, located 17.5±0.9 kpc from the Sun, gives an adequate description of the stream stellar population. The stream is detected over an extension of 8°.1 (2.5 kpc) and has a width of ∼54 pc assuming a Gaussian profile, indicating that a globular cluster (GC) is a probable progenitor. There is no known GC within 5 kpc that is compatible with being the progenitor of the stream, assuming that the stream traces its orbit. We examined overdensities (ODs) along the stream, however, no obvious counterpart-bound stellar system is visible in the coadded images. We also find ODs along the stream that appear to be symmetrically distributed—consistent with the epicyclic OD scenario for the formation of cold streams—as well as a misalignment between the northern and southern part of stream. Despite the close proximity we find no evidence that this stream and the halo cluster NGC 1261 have a common accretion origin linked to the recently found EriPhe OD

    An r -process enhanced star in the dwarf galaxy Tucana III

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    Chemically peculiar stars in dwarf galaxies provide a window for exploring the birth environment of stars with varying chemical enrichment. We present a chemical abundance analysis of the brightest star in the newly discovered ultra-faint dwarf galaxy candidate Tucana III. Because it is particularly bright for a star in an ultra-faint Milky Way (MW) satellite, we are able to measure the abundance of 28 elements, including 13 neutron-capture species. This star, DES J235532.66−593114.9 (DES J235532), shows a mild enhancement in neutron-capture elements associated with the r-process and can be classified as an r-I star. DES J235532 is the first r-I star to be discovered in an ultra-faint satellite, and Tuc III is the second extremely low-luminosity system found to contain rprocess enriched material, after Reticulum II. Comparison of the abundance pattern of DES J235532 with r-I and r-II stars found in other dwarf galaxies and in the MW halo suggests a common astrophysical origin for the neutron-capture elements seen in all r-process enhanced stars. We explore both internal and external scenarios for the r-process enrichment of Tuc III and show that with abundance patterns for additional stars, it should be possible to distinguish between them

    Discovery of a z = 0.65 post-starburst BAL quasar in the DES supernova fields

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    We present the discovery of a z = 0.65 low-ionization broad absorption line (LoBAL) quasar in a post-starburst galaxy in data from the Dark Energy Survey (DES) and spectroscopy from the Australian Dark Energy Survey (OzDES). LoBAL quasars are a minority of all BALs, and rarer still is that this object also exhibits broad Fe II (an FeLoBAL) and Balmer absorption. This is the first BAL quasar that has signatures of recently truncated star formation, which we estimate ended about 40 Myr ago. The characteristic signatures of an FeLoBAL require high column densities, which could be explained by the emergence of a young quasar from an early, dust-enshrouded phase, or by clouds compressed by a blast wave. The age of the starburst component is comparable to estimates of the lifetime of quasars, so if we assume the quasar activity is related to the truncation of the star formation, this object is better explained by the blast wave scenario

    VDES J2325−5229 a z = 2.7 gravitationally lensed quasar discovered using morphology-independent supervised machine learning

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    We present the discovery and preliminary characterization of a gravitationally lensed quasar with a source redshift zs = 2.74 and image separation of 2.9 arcsec lensed by a foreground zl = 0.40 elliptical galaxy. Since optical observations of gravitationally lensed quasars showthe lens system as a superposition of multiple point sources and a foreground lensing galaxy, we have developed a morphology-independent multi-wavelength approach to the photometric selection of lensed quasar candidates based on Gaussian Mixture Models (GMM) supervised machine learning. Using this technique and gi multicolour photometric observations from the Dark Energy Survey (DES), near-IR JK photometry from the VISTA Hemisphere Survey (VHS) and WISE mid-IR photometry, we have identified a candidate system with two catalogue components with iAB = 18.61 and iAB = 20.44 comprising an elliptical galaxy and two blue point sources. Spectroscopic follow-up with NTT and the use of an archival AAT spectrum show that the point sources can be identified as a lensed quasar with an emission line redshift of z = 2.739 ± 0.003 and a foreground early-type galaxy with z = 0.400 ± 0.002.We model the system as a single isothermal ellipsoid and find the Einstein radius θE ∼ 1.47 arcsec, enclosed mass Menc ∼ 4 × 1011 M and a time delay of ∼52 d. The relatively wide separation, month scale time delay duration and high redshift make this an ideal system for constraining the expansion rate beyond a redshift of 1

    Searching for dark matter annihilation in recently discovered Milky Way satellites with Fermi-LAT

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    We search for excess γ-ray emission coincident with the positions of confirmed and candidate Milky Way satellite galaxies using six years of data from the Fermi Large Area Telescope (LAT). Our sample of 45 stellar systems includes 28 kinematically confirmed dark-matter-dominated dwarf spheroidal galaxies (dSphs) and 17 recently discovered systems that have photometric characteristics consistent with the population of known dSphs. For each of these targets, the relative predicted γ-ray flux due to dark matter annihilation is taken from kinematic analysis if available, and estimated from a distance-based scaling relation otherwise, assuming that the stellar systems are DM-dominated dSphs. LAT data coincident with four of the newly discovered targets show a slight preference (each ~2σ local) for γ-ray emission in excess of the background. However, the ensemble of derived γ-ray flux upper limits for individual targets is consistent with the expectation from analyzing random blank-sky regions, and a combined analysis of the population of stellar systems yields no globally significant excess (global significance 1 TeV and mDM,t+t-> 70 GeV) and weakening by a factor of ~1.5 at lower masses relative to previously observed limits

    Manejo Multidisciplinario del Adenocarcinoma de Páncreas: Guía de Práctica Clínica AUNA

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    Introduction: This article provides recommendations for the Multidisciplinary Management of Pancreatic Adenocarcinoma in the RED AUNA. Methods: A systematic search of clinical practice guidelines (CPG) similar to topics of interest was developed, it was assessed with the AGREE II instrument, a list of questions was elaborated under the PICO structure, a de novo search was carried out prioritizing reviews systematic with or without meta-analysis, followed by primary studies, the elaboration of the evidence tables and the evaluation of the global quality for the outcomes of the clinical questions was carried out following the GRADE methodology. Results: 5 PICO questions corresponding to initial management and systemic management were formulated with 18 recommendations regarding the most effective method for pathological diagnosis, biliary drainage and the most effective and safe systemic treatment in the neoadjuvant, adjuvant and metastatic setting. Conclusions: This article summarizes the methodology and evidence-based recommendations of the CPG for the multidisciplinary management of pancreatic adenocarcinoma of the AUNA Clinic Network.Introducción: Este artículo brinda recomendaciones para el Manejo Multidisciplinario del Adenocarcinoma de Páncreas en la RED AUNA. Métodos: Se desarrolló una búsqueda sistemática de guías de práctica clínica (GPC) similares al tópico de interés, se valoró con el instrumento AGREE II, se elaboró un listado de preguntas bajo la estructura PICO, se realizó una búsqueda de novo priorizando revisiones sistemáticas con o sin meta-análisis, seguida de estudios primarios, la elaboración de las tablas de evidencia y la evaluación de la calidad global para los desenlaces de las preguntas clínicas se realizó siguiendo la metodología GRADE. Resultados: Se formularon 5 preguntas PICO correspondientes al manejo inicial y manejo sistémico con 18 recomendaciones respecto al método más efectivo para el diagnóstico patológico, el drenaje biliar y el tratamiento sistémico más efectivo y seguro en el escenario neoadyuvante, adyuvante y metastásico. Conclusiones: El presente artículo resume la metodología y las recomendaciones basadas en evidencia de la GPC para el manejo multidisciplinario del Adenocarcinoma de páncreas de la Red de Clínicas AUNA
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