title: Withdrawal of cigarette smoking: a study on tracheobronchial clearance.
mesh_terms: D000328:Adult; D000336:Aerosols; D001980:Bronchi / Q000502:physiology* / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D011138:Polytetrafluoroethylene; D012907:Smoking / Q000503:physiopathology*; D013667:Technetium; D013997:Time Factors; D014132:Trachea / Q000502:physiology* / Q000503:physiopathology
chemical_list: D000336:Aerosols; D013667:Technetium; D011138:Polytetrafluoroethylene