title: Intrapulmonary mixing in chronic bronchitis and emphysema.
mesh_terms: D001991:Bronchitis / Q000503:physiopathology*; D006371:Helium; D006801:Humans; D008297:Male; D008722:Methods; D011653:Pulmonary Diffusing Capacity; D011656:Pulmonary Emphysema / Q000175:diagnosis / Q000503:physiopathology*; D012129:Respiratory Function Tests; D013997:Time Factors
chemical_list: D006371:Helium