RESUMO
We use a formulation of Noether's theorem for contact Hamiltonian systems to derive a relation between the thermodynamic entropy and the Noether invariant associated with time-translational symmetry. In the particular case of thermostatted systems at equilibrium, we show that the total entropy of the system plus the reservoir are conserved as a consequence thereof. Our results contribute to understanding thermodynamic entropy from a geometric point of view.
RESUMO
We derive a formula for the dry adiabatic lapse rate of atmospheres composed of real gases. We restrict our study to those described by a family of two-parameter cubic equations of state and the recent Guevara-Rodríguez noncubic equation. Since our formula depends on the adiabatic curves, we compute them all at once, considering molecules that can move, rotate, and vibrate, for any equation of state. To illustrate our results, we estimate the lapse rate of the troposphere of Titan, obtaining a better approximation to the observed data in some instances, when compared to the estimation provided by the virial expansion up to the third order.
RESUMO
Los tumores pediátricos del sistema nervioso central (SNC) con diseminación leptomeníngea tienen mal pronóstico y es preciso encontrar nuevas alternativas terapéuticas. Una de las principales dificultades en el tratamiento de los tumores del SNC es la penetración de la barrera hematoencefálica, por lo que el tratamiento intratecal ha demostrado su eficacia en múltiples tumores pediátricos. En este artículo se revisa la experiencia disponible sobre la utilización de citarabina liposomal para pacientes pediátricos con tumores del SNC con diseminación leptomeníngea: farmacología, forma de administración, datos de seguridad y estudios de eficacia
Leptomeningeal dissemination in paediatric central nervous system (CNS) tumours is associated with a poor outcome, and new therapeutic strategies are desperately needed. One of the main difficulties in the treatment of CNS tumours is blood brain barrier penetration. Intrathecal therapy has shown to be effective in several paediatric tumours. The aim of this article is to review the data available on the use of liposomal cytarabine for paediatric patients with leptomeningeal dissemination of CNS tumours, including the pharmacology, administration, safety and efficacy data
Assuntos
Humanos , Criança , Citarabina/uso terapêutico , Aracnoide-Máter/patologia , Neoplasias Meníngeas/tratamento farmacológico , Metástase Neoplásica/patologia , Injeções Espinhais , Neoplasias do Sistema Nervoso Central/patologia , Ependimoma/tratamento farmacológico , Meduloblastoma/tratamento farmacológicoRESUMO
Leptomeningeal dissemination in paediatric central nervous system (CNS) tumours is associated with a poor outcome, and new therapeutic strategies are desperately needed. One of the main difficulties in the treatment of CNS tumours is blood brain barrier penetration. Intrathecal therapy has shown to be effective in several paediatric tumours. The aim of this article is to review the data available on the use of liposomal cytarabine for paediatric patients with leptomeningeal dissemination of CNS tumours, including the pharmacology, administration route, safety and efficacy data.
