title: Effect of gas density and expiratory flow on "closing volume".
mesh_terms: D000328:Adult; D000388:Air; D005459:Fluorides; D005740:Gases; D006371:Helium; D006801:Humans; D008297:Male; D010100:Oxygen; D011868:Radioisotopes; D012119:Respiration; D012129:Respiratory Function Tests; D013147:Spirometry; D013455:Sulfur; D014978:Xenon
chemical_list: D005740:Gases; D011868:Radioisotopes; D006371:Helium; D014978:Xenon; D013455:Sulfur; D005459:Fluorides; D010100:Oxygen