Síndrome polidípsico-poliúrico en trastornos de la conducta alimentaria de la adolescencia

Los trastornos de la conducta alimentaria son un espectro de enfermedades psiquiátricas poco frecuentes, con una prevalencia difícil de establecer en la población pediátrica. Estos desórdenes pueden tener diversas repercusiones sistémicas, dentro de las que se encuentran las alteraciones endocrinológicas. Se presenta el caso de una adolescente remitida a urgencias desde la consulta externa de endocrinología por polidipsia y poliuria. Durante la hospitalización se descartan diabetes insípida, diabetes mellitus, síndrome de secreción inadecuada de la hormona antidiurética y cerebro perdedor de sal. Por tanto, una vez excluidas las causas orgánicas, se identifica un trastorno de la conducta alimentaria que podría cursar con polidipsia psicógen

Tuning superconductivity and spin-vortex fluctuations in CaKFe4_4As4_4 through in-plane antisymmetric strains

Lattice strains of appropriate symmetry have served as an excellent tool to explore the interaction of superconductivity in the iron-based superconductors with nematic and stripe spin-density wave (SSDW) order, which are both closely tied to an orthorhombic distortion. In this work, we contribute to a broader understanding of the coupling of strain to superconductivity and competing normal-state orders by studying CaKFe$_4$As$_4$ under large, in-plane strains of $B_{1g}$ and $B_{2g}$ symmetry. In contrast to the majority of iron-based superconductors, pure CaKFe$_4$As$_4$ exhibits superconductivity with relatively high transition temperature of $T_c\,\sim\,$35 K in proximity of a non-collinear, tetragonal, hedgehog spin-vortex crystal (SVC) order. Through experiments, we demonstrate an anisotropic in-plane strain response of $T_c$, which is reminiscent of the behavior of other pnictides with nematicity. However, our calculations suggest that in CaKFe$_4$As$_4$, this anisotropic response correlates with the one of the SVC fluctuations, highlighting the close interrelation of magnetism and high-$T_c$ superconductivity. By suggesting moderate $B_{2g}$ strains as an effective parameter to change the stability of SVC and SSDW, we outline a pathway to a unified phase diagram of iron-based superconductivity.Comment: 5 pages, 4 figures + references and supplemental informatio

Consenso sobre el uso del monitor flash de glucosa de primera generación en pacientes menores de 18 años de edad con diagnóstico de diabetes mellitus tipo 1

Introducción: la diabetes mellitus tipo 1 (DM1) es una de las patologías endocrinas más frecuentes en la población pediátrica. La glucometría capilar, método de autocontrol más recomendado, se asocia con molestias que pueden disminuir la adherencia, lo que impulsó la creación de nuevas tecnologías que respondan a las necesidades de los pacientes. Objetivo: generar recomendaciones a partir del consenso de expertos acerca del uso del monitor flash de glucosa (MFG) en pacientes menores de 18 años con diagnóstico de DM1. Materiales y métodos: se realizó un consenso tipo Delphi modificado en el que participaron 8 especialistas en endocrinología pediátrica y un grupo desarrollador. A partir del análisis de los resultados, se presentaron las recomendaciones. Resultados: se obtuvieron recomendaciones acerca de indicaciones, frecuencia y modo de uso, perfil de seguridad e impacto de su uso en la calidad de vida. Conclusiones: el MFG tiene una precisión comparable con la glucometría capilar y se considera un dispositivo seguro, con la capacidad de impactar positivamente en la calidad de vida de los pacientes y sus cuidadores. Palabras clave: diabetes mellitus tipo 1, niño, adolescente, automonitorización de la glucosa sanguínea, sistema monitor flash glucosa

Stochastic semiclassical fluctuations in Minkowski spacetime

The semiclassical Einstein-Langevin equations which describe the dynamics of stochastic perturbations of the metric induced by quantum stress-energy fluctuations of matter fields in a given state are considered on the background of the ground state of semiclassical gravity, namely, Minkowski spacetime and a scalar field in its vacuum state. The relevant equations are explicitly derived for massless and massive fields arbitrarily coupled to the curvature. In doing so, some semiclassical results, such as the expectation value of the stress-energy tensor to linear order in the metric perturbations and particle creation effects, are obtained. We then solve the equations and compute the two-point correlation functions for the linearized Einstein tensor and for the metric perturbations. In the conformal field case, explicit results are obtained. These results hint that gravitational fluctuations in stochastic semiclassical gravity have a ``non-perturbative'' behavior in some characteristic correlation lengths.Comment: 28 pages, RevTeX, no figure

Stochastic semiclassical gravity

In the first part of this paper, we show that the semiclassical Einstein-Langevin equation, introduced in the framework of a stochastic generalization of semiclassical gravity to describe the back reaction of matter stress-energy fluctuations, can be formally derived from a functional method based on the influence functional of Feynman and Vernon. In the second part, we derive a number of results for background solutions of semiclassical gravity consisting of stationary and conformally stationary spacetimes and scalar fields in thermal equilibrium states. For these cases, fluctuation-dissipation relations are derived. We also show that particle creation is related to the vacuum stress-energy fluctuations and that it is enhanced by the presence of stochastic metric fluctuations.Comment: 26 pages, RevTeX, no figure

Semiclassical Equations for Weakly Inhomogeneous Cosmologies

The in-in effective action formalism is used to derive the semiclassical correction to Einstein's equations due to a massless scalar quantum field conformally coupled to small gravitational perturbations in spatially flat cosmological models. The vacuum expectation value of the stress tensor of the quantum field is directly derived from the renormalized in-in effective action. The usual in-out effective action is also discussed and it is used to compute the probability of particle creation. As one application, the stress tensor of a scalar field around a static cosmic string is derived and the backreaction effect on the gravitational field of the string is discussed.Comment: 35 pages, UAB-FT 316, Latex (uses a4wide.sty, a4.sty included in the file)(replaced due to tex problems