An extreme [O III] emitter at z = 3.2: A low metallicity Lyman continuum source

Aims. Cosmic reionization is an important process occurring in the early epochs of the Universe. However, because of observational limitations due to the opacity of the intergalactic medium to Lyman continuum photons, the nature of ionizing sources is still not well constrained. While high-redshift star-forming galaxies are thought to be the main contributors to the ionizing background at z > 6, it is impossible to directly detect their ionizing emission. Therefore, looking at intermediate redshift analogues (z ∼ 2?4) can provide useful hints about cosmic reionization. Methods. We investigate the physical properties of one of the best Lyman continuum emitter candidate at z = 3.212 found in the GOODS-S/CANDELS field with photometric coverage from the U to the MIPS 24 ?m band and VIMOS/VLT and MOSFIRE/Keck spectroscopy. These observations allow us to derive physical properties such as stellar mass, star formation rate, age of the stellar population, dust attenuation, metallicity, and ionization parameter, and to determine how these parameters are related to the Lyman continuum emission. Results. Investigation of the UV spectrum confirms a direct spectroscopic detection of the Lyman continuum emission with S/N > 5. Non-zero Lyaα flux at the systemic redshift and high Lyman-aα ESCape fraction (f(Lyaα) ≥ 0.78) suggest a low H i column density. The weak C and Si low-ionization absorption lines are also consistent with a low covering fraction along the line of sight. The subsolar abundances are consistent with a young and extreme starburst. The [O iii] iiiλλ4959, 5007+Hβ equivalent width (EW) is one of the largest reported for a galaxy at z > 3 (EW([O iii] λλ4959, 5007 + Hβ) ≈1600 Å, rest-frame; 6700 Å observed-frame) and the near-infrared spectrum shows that this is mainly due to an extremely strong [O iii] emission. The large observed [O iii]/[O ii] ratio (>10) and high ionization parameter are consistent with prediction from photoionization models in the case of a density-bounded nebula scenario. Furthermore, the EW([O iiiλλ4959, 5007+Hβ) is comparable to recent measurements reported at z ∼ 7?9, in the reionization epoch. We also investigate the possibility of an AGN contribution to explain the ionizing emission but most of the AGN identification diagnostics suggest that stellar emission dominates instead. Conclusions. This source is currently the first high-z example of a Lyman continuum emitter exhibiting indirect and direct evidences of a Lyman continuum leakage and having physical properties consistent with theoretical expectation from Lyman continuum emission from a density-bounded nebula. A low H i column density, low covering fraction, compact star formation activity, and a possible interaction/merging of two systems may contribute to the Lyman continuum photon leakage. © 2015 ESO.We acknowledge the financial contribution from PRIN-INAF 2012.Peer Reviewe

Gangrena gaseosa: revisión de cuatro casos

Desde el mes de enero de 1988 hasta diciembre de 1993, hemos atendido en el Servicio de Cirugía Ortopédica y Traumatología 6.853 pacientes, de ellos 263 presentaron infecciones post-quirúrgicas, post-traumáticas o expontáneas. Del total de infecciones cuatro se manifestaron como un cuadro clínico de gangrena gaseosa. El origen fue post-traumático en tres casos y por arma de fuego en uno, localizándose la enfermedad en todos los pacientes en las extremidades inferiores. Para establecer el diagnóstico además de las manifestaciones clínicas se ha valorado el resultado bacterológico y anatomo-patológico de las muestras analizadas. El tratamiento consistió en Cirugía precoz, antibioticoterapia y oxigenoterapia hiperbárica cuando era necesario. La evolución ha sido buena en dos casos y desfavorable en el resto de los enfermos.From January 1988 to December 1993, we have seen in our institution 6853 patients, 263 of them presented post-surgical, post-traumatic or spontaneus infections. Of the total of infections, four of them were manifested as clinical cases of gaseous gangrene. The origin was post-traumatic in three cases, and gun shot in one case, localizing the disease in all patients in inferior extremities. For diagnosis clinical manifestations and the bacteriological and patologic results were evaluated. The treatment consisted of early surgery, antibiotical therapy and hiperbaric oxigenotherapy when it was necessary. The outcome was satisfactory in two cases and non favorable in the other two patients

Multiscale thermo-mechanical analysis of multi-layered coatings in solar thermal applications

Solar selective coatings can be multi-layered materials that optimize the solar absorption while reducing thermal radiation losses, granting the material long-term stability. These layers are deposited on structural materials (e.g., stainless steel, Inconel) in order to enhance the optical and thermal properties of the heat transfer system. However, interesting questions regarding their mechanical stability arise when operating at high temperatures. In this work, a full thermo-mechanical multiscale methodology is presented, covering the nano-, micro-, and macroscopic scales. In such methodology, fundamental material properties are determined by means of molecular dynamics simulations that are consequently implemented at the microstructural level by means of finite element analyses. On the other hand, the macroscale problem is solved while taking into account the effect of the microstructure via thermo-mechanical homogenization on a representative volume element (RVE). The methodology presented herein has been successfully implemented in a reference problem in concentrating solar power plants, namely the characterization of a carbon-based nanocomposite and the obtained results are in agreement with the expected theoretical values, demonstrating that it is now possible to apply successfully the concepts behind Integrated Computational Materials Engineering to design new coatings for complex realistic thermo-mechanical applications

Prótesis total de cadera con doble recubrimiento de porometal e hidroxiapatita: resultados preliminares

El objetivo de este trabajo es evaluar la eficacia de la prótesis con superficie de Poropatita, recubrimiento doble de Poropros e Hidroxiapatita, para su fijación ósea directa en el reemplazo total de cadera. El estudio ha sido llevado a cabo en 80 pacientes con un seguimiento mínimo de 3 años. La valoración clínica se ha realizado según el sistema de Harris modificado, obteniendo un 90% de buenos resultados y un 10% de resultados regulares en la serie estudiada. El análisis, revisado a partir de parámetros clínicos y radiográficos, permite apreciar que el recubrimiento de un metal poroso con hidroxiapatita supone un mecanismo de seguridad en la fijación primaria como secundaria del implante. La estabilidad inmediata del componente femoral y cotiloideo, factor importante en la osteointegración del implante.This study was aimed at evaluating the outcome in terms of primary bone fixation of a total hip prosthesis coated with Poropatita® , o double coating of porous-metal and hidroxyapatite. The study reviews 80 patients operated on with a minimum follow-up of 3 years. A modified Harris score was used for clinical assessment. Good clinical results wer obtained in 9 0% of patients, while 10% achieved a fair outcome. Based on clinical and radiographic parameters, porous-metal and hidroxyapatite double coating provides both excellent primary and secondary bone fixation of the prosthetic components. Primary stability of both femoral stem and cup seens to be an important factor for osteointegration of the implant

La artroscopia de rodilla: experiencia de 474 casos

El objetivo de este trabajo es dar a conocer los resultados de un estudio de 474 artroscopias realizadas en nuestro Servicio de Cirugía Ortopédica y Traumatología desde el mes de enero 1988 hasta agosto 1992. La edad media de los pacientes fue de 32 años, con una mayor incidencia en el sexo masculino (73%). La patología más frecuente correspondió a la meniscopatía interna (48%). Tuvimos una estancia media hospitalaria de 3 días, apreciándose una relación inversa entre ésta y la edad del paciente. La complicación más habitual en el post-operatorio fue el derrame sinovial (3%) siendo necesaria al artrocentesis para su desaparición en el plazo de 1-2 semanas.This work was aimed at presenting the results of 474 diagnostic artroscopies of the knee performed in our Department of orthopaedic surgery from January 1988 to August 1992. The mean age of the patients was 32 years. There was a greater incidence in males (73%). The most frequent pathologic finding was medial meniscopathy (48%). The mean period of hospitalization was 3 days. There was an opposite relationship betwen the hospitalization period and the age of the patient. As complications, synovial effusion was found in 3% of cases, synovial fluid evacuation been necessary

INTRABEAM: precision hypo-fractionated radiotherapy with a systemic immune response

Purpose or Objective: To evaluate the changes in immune-cell phenotype in peripheral blood following intraoperative radiotherapy (IORT) in breast cancer patients