1. Pulmonary and Critical Care Service. Dr. José Eleuterio González University Hospital. UANL. Monterrey, México
2. Pulmonary Service. Clínic Hospital. UB-IDIBAPS. Barcelona, Spain
3. CIBER de enfermedades respiratorias (CIBERES). Madrid, Spain
4. Unit of Biophysics and Bioengineering. Faculty of Medicine. IDIBAPS. University of Barcelona. Barcelona, Spain
5. Bio-Araba Research Institute and Clinical Research Unit, Hospital Universitario Araba. Vitoria, Spain
6. Pulmonary Service. Sagrat Cor Hospital. Barcelona, Spain
7. Respiratory Dept. IRBLleida. Lleida, Spain
8. Pulmonary Service. Hospital San Pedro de Alcantara. Cáceres. Spain