19 research outputs found

    Near-infrared spectroscopy in NGC 7538

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    The characterisation of the stellar population toward young high-mass star-forming regions allows to constrain fundamental cluster properties like distance and age. These are essential when using high-mass clusters as probes to conduct Galactic studies. NGC 7538 is a star-forming region with an embedded stellar population only unearthed in the near-infrared. We present the first near-infrared spectro-photometric study of the candidate high-mass stellar content in NGC 7538. We obtained H and K spectra of 21 sources with both the multi-object and long-slit modes of LIRIS at the WHT, and complement these data with sub-arcsecond JHKs photometry of the region using the imaging mode of the same instrument. We find a wide variety of objects within the studied stellar population of NGC 7538. Our results discriminate between a stellar population associated to the HII region, but not contained within its extent, and several pockets of more recent star formation. We report the detection of CO bandhead emission toward several sources as well as other features indicative of a young stellar nature. We infer a spectro-photometric distance of 2.7+-0.5 kpc, an age spread in the range 0.5-2.2 Myr and a total mass ~1.7x10^3 Msun for the older population.Comment: 11 pages, 8 figures, 1 table, accepted by A&

    Derivation and external validation of the SIMPLICITY score as a simple immune-based risk score to predict infection in kidney transplant recipients

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    Existing approaches for infection risk stratification in kidney transplant recipients are suboptimal. Here, we aimed to develop and validate a weighted score integrating non-pathogen-specific immune parameters and clinical variables to predict the occurrence of post-transplant infectious complications. To this end, we retrospectively analyzed a single-center derivation cohort of 410 patients undergoing kidney transplantation in 2008-2013 in Madrid. Peripheral blood lymphocyte subpopulations, serum immunoglobulin and complement levels were measured at one-month post-transplant. The primary and secondary outcomes were overall and bacterial infection through month six. A point score was derived from a logistic regression model and prospectively applied on a validation cohort of 522 patients undergoing kidney transplantation at 16 centers throughout Spain in 2014-2015. The SIMPLICITY score consisted of the following variables measured at month one after transplantation: C3 level, CD4+ T-cell count, CD8+ T-cell count, IgG level, glomerular filtration rate, recipient age, and infection within the first month. The discrimination capacity in the derivation and validation cohorts was good for overall (areas under the receiver operating curve of 0.774 and 0.730) and bacterial infection (0.767 and 0.734, respectively). The cumulative incidence of overall infection significantly increased across risk categories in the derivation (low-risk 13.7%; intermediate-risk, 35.9%; high-risk 77.6%) and validation datasets (10.2%, 28.9% and 50.4%, respectively). Thus, the SIMPLICITY score, based on easily available immune parameters, allows for stratification of kidney transplant recipients at month one according to their expected risk of subsequent infection

    Near-infrared study of the stellar population of Sh2-152

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    Context: The discovery of new massive star clusters and massive stellar populations in previously known clusters in our Galaxy by means of infrared studies has changed our view of the Milky Way from an inactive to an active star-forming machine. Within this scenario, we present a near-infrared spectrophotometric study of the stellar content of the compact H II region Sh2-152. Aims: We aim to determine the distance, extinction, age, and mass of Sh2-152, using for the first time near-infrared stellar classification for several sources in the region. Methods: Using our near-infrared (J, H, and Ks) photometry and the colour-magnitude diagram for the cluster field, we selected 13 bright stars, candidate members of the reddened cluster's main sequence, for H- and K- spectroscopy and spectral classification. This near-infrared information was complemented with an optical spectrum of the ionizing central star to confirm its spectral nature. Results: From the 13 spectroscopically observed stars, 5 were classified as B-type, 3 as G-type, 2 were young stellar objects (YSOs), and 3 remained unclassified (because of the poor data quality). The cluster's extinction varies from A_{Ks}=0.5 to 2.6 magnitudes (A_V=4.5 to 24 magnitudes) and the distance is estimated to be 3.21\pm0.21 kpc. The age of the cluster is younger than 9.4 Myr and the lower limit to the total mass of the cluster is (2.45\pm0.79)\cdot10^3 M_{Sun}. We compare the number of ionizing photons emitted from the OB-type stars with the Lyman continuum photons derived from the radio observations and conclude that both quantities are consistent for the central region of Sh2-152. In contrast, the main ionizing source of the lower region remains unidentified.Comment: 12 pages, 10 figures, 3 tables, A\&A, in pres

    The Neutrophil Life Cycle.

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    Neutrophils are recognized as an essential part of the innate immune response, but an active debate still exists regarding the life cycle of these cells. Neutrophils first differentiate in the bone marrow through progenitor intermediaries before entering the blood, in a process that gauges the extramedullary pool size. Once believed to be directly eliminated in the marrow, liver, and spleen, neutrophils, after circulating for less than 1 day, are now known to redistribute into multiple tissues with poorly understood kinetics. In this review, we provide an update on the dynamic distribution of neutrophils across tissues in health and disease, and emphasize differences between humans and model organisms. We further highlight issues to be addressed to exploit the unique features of neutrophils in the clinic

    Approaches in biotechnological applications of natural polymers

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    Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

    Apéndice a los Ecos Dolientes.

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    Copia digital : Biblioteca de Galicia, 201

    Homenaje a don José Toribio Medina

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    Incluye:- Facultad de filosofía y ciencias de la educación: sesión extraordinaria en 12 y 19 de diciembre de 1930 . Por Luis Galdames, Luis A. Puga y Raúl Ramírez.- Consejo universitario: sesión ordinaria en 15 de diciembre de 1930. Por J. Castro Oliveira y Gustavo Lira. - Don José Toribio Medina: la obra del mayor de los bibliógrafos americanos. Por Armando Alonso.- La obra de Medina. Por L. Briones.- Don José Toribio Medina (Editorial de "El Mercurio" de 12 de diciembre de 1930)- Don José Toribio Medina (Editorial de "La Nación" de 12 de diciembre de 1930

    An RFID-Based Digital Bracelet for the Timely Assistance of Indigents

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    High rates of indigence characterize several countries in Latin America, such as Mexico. In the north of our country, the phenomenon of migration contributes to indigence. To get a preliminary understanding of the needs of indigents in our community, we conducted interviews with homeless and migrants. This helped us identify preliminary system requirements that led to the design of a digital bracelet to enable local agencies to monitor and provide support to the indigents who roam the city. We refined our conceptual design through an iterative process of contextual inquiry, persona development, prototyping, and user assessment. An evaluation of our design was conducted with the coordinator of the main social assistance agency of the municipality, which allowed us to confirm the system potential to be used and adopted
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