Cálculo de índices de confort térmico en recintos cerrados con transferencia de calor

El trabajo que se presenta forma parte de los estudios que el grupo de investigación "Análisis Térmico y Ventilación en la Ingeniería y la Edificación" está desarrollando para la realización del Proyecto "Estudio de la eficiencia energética y del confort en un edificio bioclimático" en la Universidad Politécnica de Madrid. El objetivo general de dicho proyecto es aportar, a través de modelos físicos y datos experimentales, información relevante que sirva para optimizar el consumo energético de una vivienda bioclimática en la Comunidad de Madrid. Con este fin, en el presente trabajo se simula el comportamiento del aire en una habitación, mediante un modelo CFD (Computational Fluid Dynamics), con el fin de determinar los índices deconfort térmico en el recinto, bajo dos supuestos de calefacción utilizados en edificación: radiadores y suelo radiante

Switching TNF antagonists in patients with chronic arthritis: An observational study of 488 patients over a four-year period

The objective of this work is to analyze the survival of infliximab, etanercept and adalimumab in patients who have switched among tumor necrosis factor (TNF) antagonists for the treatment of chronic arthritis. BIOBADASER is a national registry of patients with different forms of chronic arthritis who are treated with biologics. Using this registry, we have analyzed patient switching of TNF antagonists. The cumulative discontinuation rate was calculated using the actuarial method. The log-rank test was used to compare survival curves, and Cox regression models were used to assess independent factors associated with discontinuing medication. Between February 2000 and September 2004, 4,706 patients were registered in BIOBADASER, of whom 68% had rheumatoid arthritis, 11% ankylosing spondylitis, 10% psoriatic arthritis, and 11% other forms of chronic arthritis. One- and two-year drug survival rates of the TNF antagonist were 0.83 and 0.75, respectively. There were 488 patients treated with more than one TNF antagonist. In this situation, survival of the second TNF antagonist decreased to 0.68 and 0.60 at 1 and 2 years, respectively. Survival was better in patients replacing the first TNF antagonist because of adverse events (hazard ratio (HR) for discontinuation 0.55 (95% confidence interval (CI), 0.34-0.84)), and worse in patients older than 60 years (HR 1.10 (95% CI 0.97-2.49)) or who were treated with infliximab (HR 3.22 (95% CI 2.13-4.87)). In summary, in patients who require continuous therapy and have failed to respond to a TNF antagonist, replacement with a different TNF antagonist may be of use under certain situations. This issue will deserve continuous reassessment with the arrival of new medications. © 2006 Gomez-Reino and Loreto Carmona; licensee BioMed Central Ltd