Cardiac Arrest in the Pediatric Population

Apresenta-se o caso clínico de uma criança de 10 anos com paragem cardíaca em repouso que foi reanimada, com sucesso. A investigação etiológica do acidente mostrou uma Cardiomiopatia Hipertrófica (CMH). Foi colocado um Cardiodesfibrilhador Implantável (CDI) para profilaxia secundária da Morte Súbita (MS). A Morte Súbita em idade pediátrica é uma situação rara, de muito mau prognóstico (sobrevida sem sequelas inferior a 5%) e com um impacto social significativo. A Cardiomiopatia Hipertrófica é uma causa conhecida de Morte Súbita, com possibilidade de prevenção. O caso apresentado serve para levantar questões sobre a necessidade e forma de estratégias para prevenir a MS de etiologica cardíaca em idade pediátrica

Coupled electric and magnetic dipole formulation for planar arrays of dipolar particles: metasurfaces with various electric and/or magnetic meta-atoms per unit cell

The optical properties of infinite planar array of scattering particles, metasurfaces and metagratings, are attracting special attention lately for their rich phenomenology, including both plasmonic and high-refractive-index dielectric meta-atoms with a variety of electric and magnetic resonant responses. Herein we derive a coupled electric and magnetic dipole (CEMD) analytical formulation to describe the reflection and transmission of such periodic arrays, including specular and diffractive orders, valid in the spectral regimes where only dipolar multipoles are needed. Electric and/or magnetic dipoles with all three orientations arising in turn from a single or various meta-atoms per unit cell are considered. The 2D lattice Green function is rewritten in terms of a 1D (chain) version that fully converges and can be easily calculated. Modes emerging as poles of such lattice Green function can be extracted. This formulation can be applied to investigate a wealth of plasmonic, all-dielectric, and hybrid metasurfaces/metagratings of interest throughout the electromagnetic spectrum.Comment: 8 pages, 4 figure

Biological actions and determinant factors of the circulating concentrations of insulin-like growth factor type 1, IGF-1, in the horse

El eje somatotrópico es esencial para el desarrollo somático del organismo, determinando el metabolismo celular. Aunque está constituido por diversas hormonas, los componentes esenciales son tres: la insulina, la hormona de crecimiento o GH y los factores de crecimiento similares a la insulina, tipos 1 y 2 (IGF-1 e IGF-2). La cuantificación de la GH es complicada debido, en primer lugar, a su liberación episódica hacia la circulación sistémica y en segundo lugar, a su corta vida media en sangre, unos 20 min. Uno de los lugares de actuación de la GH es el hígado, donde induce la síntesis de IGF-1 e IGF-2. La cuantificación de estos factores, por tanto, se considera un marcador fiable de la función hipofisaria y de la actividad del eje somatotrópico. En la presente revisión bibliográfica, en primer lugar, se describen las principales acciones biológicas del IGF-1. En segundo lugar, se presentan los factores principales que afectan significativamente a sus concentraciones circulantes. Entre estos factores, destacan el tamaño corporal, raza, edad, sexo, momento de la extracción de la muestra, ritmos circadianos, dieta, privación de comida, ejercicio y entrenamiento. El efecto de estos factores debe ser conocido antes de llevar a cabo una aplicación clínica e investigadora del IGF-1 en el caballoThe somatotropic axis is pivotal for somatic development and cell metabolism. Although it is composed by several hormones, the most important components are three: insulin, growth hormone or GH and insulin-like growth factors type 1 and 2 (IGF- 1 and IGF-2). The measurement of GH is difficult and inaccurate, because two main reasons: firstly, the GH hormone is released in an episodic way and secondly, its blood half-life is short, about 20 min. The GH hormone has significant actions on the liver, inducing the synthesis of IGF-1 and IGF-2. The measurement of these factors, therefore, is considered a reliable marker of the activity of the hypophysis and the somatotropic axis. In the present review, firstly, we will describe the main biological actions of the IGF-1 and secondly, we will define the main factors that could significantly influence the circulating concentrations of IGF-1. Among these factors, the most important are body size, breed, age, gender, time of blood extraction, circadian rhythms, diet, food privation, exercise and training. The effect of these factors should be assessed prior to extended clinical and research use of IGF-1 in horse

Variations in the dip properties of the low-mass X-ray binary XB 1254-69 observed with XMM-Newton and INTEGRAL

We have analysed data from five XMM-Newton observations of XB 1254-69, one of them simultaneous with INTEGRAL, to investigate the mechanism responsible for the highly variable dips durations and depths seen from this low-mass X-ray binary. Deep dips were present during two observations, shallow dips during one and no dips were detected during the remaining two observations. At high (1-4 s) time resolution ``shallow dips'' are seen to include a few, very rapid, deep dips whilst the ``deep'' dips consist of many similar very rapid, deep, fluctuations. The folded V-band Optical Monitor light curves obtained when the source was undergoing deep, shallow and no detectable dipping exhibit sinusoid-like variations with different amplitudes and phases. We fit EPIC spectra obtained from "persistent" or dip-free intervals with a model consisting of disc-blackbody and thermal comptonisation components together with Gaussian emission features at 1 and 6.6 keV modified by absorption due to cold and photo-ionised material. None of the spectral parameters appears to be strongly correlated with the dip depth except for the temperature of the disc blackbody which is coolest (kT ~ 1.8 keV) when deep dips are present and warmest (kT ~ 2.1 keV) when no dips are detectable. We propose that the changes in both disc temperature and optical modulation could be explained by the presence of a tilted accretion disc in the system. We provide a revised estimate of the orbital period of 0.16388875 +/- 0.00000017 day.Comment: 16 pages, 10 figures, 4 tables. Accepted for publication in A&

The 2011 October Draconids Outburst. II. Meteoroid Chemical Abundances from Fireball Spectroscopy

On October 8, 2011 the Earth crossed dust trails ejected from comet 21P/Giacobini-Zinner in the late 19th and early 20th Century. This gave rise to an outburst in the activity of the October Draconid meteor shower, and an international team was organized to analyze this event. The SPanish Meteor Network (SPMN) joined this initiative and recorded the October Draconids by means of low light level CCD cameras. In addition, spectroscopic observations were carried out. Tens of multi-station meteor trails were recorded, including an extraordinarily bright October Draconid fireball (absolute mag. -10.5) that was simultaneously imaged from three SPMN meteor ob-serving stations located in Andalusia. Its spectrum was obtained, showing a clear evolution in the relative intensity of emission lines as the fireball penetrated deeper into the atmosphere. Here we focus on the analysis of this remarkable spectrum, but also discuss the atmospheric trajectory, atmospheric penetration, and orbital data computed for this bolide which was probably released during 21P/Giacobini-Zinner return to perihelion in 1907. The spectrum is discussed together with the tensile strength for the October Draconid meteoroids. The chemical profile evolution of the main rocky elements for this extremely bright bolide is compared with the elemental abundances obtained for 5 October Draconid fireballs also recorded during our spectroscopic campaign but observed only at a single station. Significant chemical heterogeneity between the small meteoroids is found as we should expect for cometary aggregates being formed by diverse dust components.Comment: Manuscript in press in Monthly Notices of the Royal Astronomical Society. Accepted for publication in MNRAS on April 28th, 2013 Manuscript Pages: 28 Tables: 5 Figures: 12. Manuscript associated: "The 2011 October Draconids outburst. I. Orbital elements, meteoroid fluxes and 21P/Giacobini-Zinner delivered mass to Earth" by Trigo-Rodriguez et al. is also in press in the same journa