1. Adolphe Merkle Institute; University of Fribourg; Route de l'Ancienne Papeterie P.O. Box 209 Marly 1723 (Switzerland)
2. Respiratory Medicine; Bern University Hospital, Inselspital; Freiburgstrasse Bern 3010 (Switzerland)
3. Department of Chemistry; University of Fribourg; Chemin du Musee 9 Fribourg 1700 (Switzerland)