Magnetic multiwalled carbon nanotubes as nanocarrier tags for sensitive determination of fetuin in saliva

This paper reports the development and performance of an electrochemical immunosensor using magnetic multiwalled carbon nanotubes (m-MWCNTs) as nanocarrier tags for the determination of human fetuin A (HFA), a relevant biomarker of obesity, insulin resistance, and type-2 diabetes as well as for pancreatic and liver cancers and inflammatory processes. Screen-printed carbon electrodes were grafted with p-aminobezoic acid and streptavidin was covalently immobilized on the electrode surface. A biotinylated capture antibody was immobilized through streptavidin-biotin interaction and a sandwich assay configuration was implemented using m-MWCNTs conjugated with HRP and anti-HFA antibodies as the detection label. The determination of HFA was accomplished by measuring the current produced by the electrochemical reduction of benzoquinone at -200 mV upon addition of H2O2 as HRP substrate. The prepared m-MWCNTs were characterized by SEM, TEM, XRD and EDS. All the steps involved in the immunosensor preparation were monitored by electrochemical impedance spectroscopy and cyclic voltammetry. A linear calibration plot for HFA was found between 20 and 2000 pg/mL with a LOD value of 16 pg/mL. This performance is notably better than that reported for an ELISA kit and a chronoimpedimetric immunosensor. The favorable contribution of m-MWCNTs in comparison with MWCNTs without incorporated magnetic particles to this excellent analytical performance is also highlighted. The immunosensor selectivity against other proteins and potentially interfering compounds was excellent. In addition, the usefulness of the immunosensor was demonstrated by the analysis of HFA in saliva with minimal sample treatment

Searching for galactic sources in the Swift GRB catalog

Since the early 1990s Gamma Ray Bursts have been accepted to be of extra-galactic origin due to the isotropic distribution observed by BATSE and the redshifts observed via absorption line spectroscopy. Nevertheless, upon further examination at least one case turned out to be of galactic origin. This particular event presented a Fast Rise, Exponential Decay (FRED) structure which leads us to believe that other FRED sources might also be Galactic. This study was set out to estimate the most probable degree of contamination by galactic sources that certain samples of FREDs have. In order to quantify the degree of anisotropy the average dipolar and quadripolar moments of each sample of GRBs with respect to the galactic plane were calculated. This was then compared to the probability distribution of simulated samples comprised of a combination of isotropically generated sources and galactic sources. We observe that the dipolar and quadripolar moments of the selected subsamples of FREDs are found more than two standard deviations outside those of random isotropically generated samples.The most probable degree of contamination by galactic sources for the FRED GRBs of the Swift catalog detected until February 2011 that do not have a known redshift is about 21 out of 77 sources which is roughly equal to 27%. Furthermore we observe, that by removing from this sample those bursts that may have any type of indirect redshift indicator and multiple peaks gives the most probable contamination increases up to 34% (17 out of 49 sources). It is probable that a high degree of contamination by galactic sources occurs among the single peak FREDs observed by Swift.Comment: Published to A&A, 4 pages, 5 figures, this arXiv version includes appended table with all the bursts considered in this stud

The optical counterpart of the bright X-ray transient Swift J1745-26

We present a 30-day monitoring campaign of the optical counterpart of the bright X-ray transient Swift J1745-26, starting only 19 minutes after the discovery of the source. We observe the system peaking at i' ~17.6 on day 6 (MJD 56192) to then decay at a rate of ~0.04 mag/day. We show that the optical peak occurs at least 3 days later than the hard X-ray (15-50 keV) flux peak. Our measurements result in an outburst amplitude greater than 4.3 magnitudes, which favours an orbital period < 21 h and a companion star with a spectral type later than ~ A0. Spectroscopic observations taken with the GTC-10.4 m telescope reveal a broad (FWHM ~ 1100 km/s), double-peaked H_alpha emission line from which we constrain the radial velocity semi-amplitude of the donor to be K_2 > 250 km/s. The breadth of the line and the observed optical and X-ray fluxes suggest that Swift J1745-26 is a new black hole candidate located closer than ~7 kpc.Comment: 5 pages, 4 figures, accepted for publication in MNRA

The 1989 and 2015 outbursts of V404 Cygni: a global study of wind-related optical features

The black hole transient V404 Cygni exhibited a bright outburst in June 2015 that was intensively followed over a wide range of wavelengths. Our team obtained high time resolution optical spectroscopy (~90 s), which included a detailed coverage of the most active phase of the event. We present a database consisting of 651 optical spectra obtained during this event, that we combine with 58 spectra gathered during the fainter December 2015 sequel outburst, as well as with 57 spectra from the 1989 event. We previously reported the discovery of wind-related features (P-Cygni and broad-wing line profiles) during both 2015 outbursts. Here, we build diagnostic diagrams that enable us to study the evolution of typical emission line parameters, such as line fluxes and equivalent widths, and develop a technique to systematically detect outflow signatures. We find that these are present throughout the outburst, even at very low optical fluxes, and that both types of outflow features are observed simultaneously in some spectra, confirming the idea of a common origin. We also show that the nebular phases depict loop patterns in many diagnostic diagrams, while P-Cygni profiles are highly variable on time-scales of minutes. The comparison between the three outbursts reveals that the spectra obtained during June and December 2015 share many similarities, while those from 1989 exhibit narrower emission lines and lower wind terminal velocities. The diagnostic diagrams presented in this work have been produced using standard measurement techniques and thus may be applied to other active low-mass X-ray binaries.Comment: Accepted for publication in MNRAS. 23 pages paper, plus a 9 pages appendix with extra tables and figures. 18 figures are included in the paper and 8 in the appendi

Esophageal diverticulum: a case report

Esophagic diverticulum’s are a rare entity. The prevalence in the world population is reported to be less than 1%. They are generally diagnosed incidentally, have a higher peak of prevalence in the fifth decade of life, affecting men and women equally. The most common esophageal diverticula are epiphrenic and the main symptom is usually dysphagia. A case of a 74-year-old female with diagnosis of epiphrenic esophageal diverticulum is reported, which is treated with conservative management. The objective of this study was to describe a clinical case of esophageal diverticulum, as well as its etiology, clinical presentation, and therapeutic conduct. The screening of these patients must be focused on what the literature indicates, symptomatic patients with long-term evolution, the treatment will be surgical and with minimally invasive techniques so clinical evolution will be more favorable, reducing possible complications

A decade of GRB follow-up by BOOTES in Spain (2003-2013)

This article covers ten years of GRB follow-ups by the Spanish BOOTES stations: 71 follow-ups providing 23 detections. Follow-ups by BOOTES-1B from 2005 to 2008 were given in the previous article, and are here reviewed, updated, and include additional detection data points as the former article merely stated their existence. The all-sky cameras CASSANDRA have not yet detected any GRB optical afterglows, but limits are reported where available

Estratificación de riesgo de VIH/SIDA / Stratification of the risk of HIV/AIDS

La estratificación epidemiológica, permitió identificar los consejos populares del municipio con similitudes en el comportamiento de diversos factores de riesgo, con el propósito de contribuir a la selección de los sitios de mayor riesgo en el incremento de la incidencia de seropositivos alVIH/SIDA y así establecer la vigilancia y control epidemiológico de este problema de salud, además, de aplicar intervenciones de acuerdo con las condiciones de cada estrato, facilitar la planificación y ubicación de recursos. Se realizó un estudio epidemiológico, descriptivo y transversal, para la estratificación de riesgo de los consejos populares en el municipio, sobre la distribución de los factores seleccionados de VIH/Sida, durante el período comprendido entre enero de 2007 al 31 de diciembre del 2009. El universo estuvo integrado por todos los consejos populares del municipio San Cristóbal, en los cuales se compararon las diferencias obtenidas entre los Consejos "casos" y los Consejos "controles", para los factores seleccionados: presencia de contactos con enfermos VIH/ SIDA, presencia de casos con conductas o comportamientos inadecuados, presencia de reclusorios, poca información sobre la enfermedad e inobservancia de normas de bioseguridad. La opinión de expertos fue decisiva a la hora de determinar los estratos epidemiológicos de riesgo, para los cuales, fue implementado un plan de intervención que abarcará medidas que favorecen la participación intersectorial y comunitaria.Palabras clave: SÍNDROME DE INMUNODEFICIENCIA ADQUIRIDA/epidemiología, prevención & control, FACTORES DE RIESGO, EPIDEMIOLOGÍA/clasificación. Stratification of the risk of HIV/AIDSABSTRACTThe epidemiological stratification allowed identifying the Popular Councils of the municipality with similarities in the behavior of diverse risk factors with the purpose of selecting the sites that presented the highest risks in the increase of seropositive incidence (HIV/AIDS) to establish the epidemiological surveillance and control of this health problem applying health interventions regarding the conditions of each stratus to draw up a plan and to arrange the resources. An epidemiological, descriptive and cross-sectional research was conducted with the purpose of stratifying the risks (HIV/AIDS) in the municipal Popular Councils and distribution of the factors chosen during January 2007 to December 2009. The target group was comprised of the Popular Councils in San Cristobal, where the differences obtained were compared among the "cases" Councils and "control" Councils to the factors chosen: presence of the contacts with HIV/AIDS carrier, cases with misconduct or inappropriate conduct and reclusive behavior, lack of information about the disease and non-observance of the security norms. The opinion of the experts on the subject was conclusive to determine the epidemiological stratus of the risk to establish a plan of intervention considering the measures that favour the inter-sectorial and community participation.Key words: Acquired inmunodeficiency syndrome/epidemiology/prevention & control, RISK FACTORS, EPIDEMIOLOGY/classification

Comprehensive multi-wavelength modelling of the afterglow of GRB050525A

The Swift era has posed a challenge to the standard blast-wave model of Gamma Ray Burst (GRB) afterglows. The key observational features expected within the model are rarely observed, such as the achromatic steepening (`jet-break') of the light curves. The observed afterglow light curves showcase additional complex features requiring modifications within the standard model. Here we present optical/NIR observations, millimeter upper limits and comprehensive broadband modelling of the afterglow of the bright GRB 0505025A, detected by Swift. This afterglow cannot be explained by the simplistic form of the standard blast-wave model. We attempt modelling the multi-wavelength light curves using (i) a forward-reverse shock model, (ii) a two-component outflow model and (iii) blast-wave model with a wind termination shock. The forward-reverse shock model cannot explain the evolution of the afterglow. The two component model is able to explain the average behaviour of the afterglow very well but cannot reproduce the fluctuations in the early X-ray light curve. The wind termination shock model reproduces the early light curves well but deviates from the global behaviour of the late-time afterglow.Comment: 20 pages, 6 figures, accepted for publication in MNRA

Guía psicopedagógica para estudiantes y profesores universitarios en el Espacio Europeo de Educación Superior

Esta Guía pone a vuestra disposición algunas de las claves de información y análisis necesarias para conocer, entender y hacer frente a las dificultades que conlleva el proceso de estudiar, aprender y formarse a lo largo de la vida. En ella podéis encontrar información acerca del EEES y ECTS, una descripción de cómo usar este recurso y toda la información de carácter académico-personal, que aparece estructurada en tres bloques: en el primer bloque, presentamos un análisis funcional de las principales variables y procesos que condicionan el ajuste a las exigencias de la vida universitaria; el segundo, contiene 25 temas relacionados con esas variables y procesos desde un punto de vista descriptivo, explicativo y preventivo. Entre los temas tratados se encuentran: hábitos de estudio: planificación y organización del tiempo, procrastinación, exámenes tipo test, técnicas de estudio, ansiedad y miedo a hablar en publico, ansiedad ante los exámenes, problemas de sueño, relaciones de pareja, orientación sexual, problemas con el alcohol, cannabis, habilidades sociales: asertividad, etc.; el tercer bloque, ofrece un conjunto de materiales de auto-evaluación, de auto-intervención y de auto-seguimiento, que pretenden serte de ayuda para mejorar tu rendimiento académico y satisfacción con los estudios. Por último, este material también cuenta con un glosario de términos de consulta para apoyarte en la comprensión de las ideas, conceptos, trucos, recomendaciones y recursos seleccionados para esta Guía.This Guide provides a useful foundation for students to know, understand and deal with the main challenges imbibed in the process of studying and learning, not only during the University years, but throughout the lifelong learning process. Inside, you can find information about the European Higher Education Area and the European Credit Transfer System, a detailed description about how to use this resource, as well as information on academic and personal issues organized into three parts. The first one contains a psychological functional analysis of the main variables and processes that determine the adjustment level of students to the challenges posed by the University life. The second one includes information, definitions, explanations and recommendations on twenty five of those main variables, factors and processes. Among others, the themes included are: Study habits and strategies like planification of tasks and organization of time, procrastination, multiple choice exam, study techniques, anxiety, exams ´anxiety, talking in public, sleep problems, couple relationships, sexual orientation, alcohol problems, cannabis, social skills, assertively, etc. The third bloc includes several examples and materials ready to be used for self-evaluation, self-intervention, and self-following up, effective to improve academic performance and personal satisfaction with your studies. Finally, a glossary with basic key terms is included to help you to better understand the ideas, concepts, tips, recommendations and resources selected for this Guide.Universidad de Granada, Vicerrectorado de Estudiante