title: Long-term oxygen therapy in COPD.
mesh_terms: D004920:Erythropoiesis; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000503:physiopathology / Q000628:therapy*; D010100:Oxygen / Q000627:therapeutic use*; D013997:Time Factors
chemical_list: D010100:Oxygen