CAT and chronic obstructive pulmonary disease: injury (612/14.4%), model (565/13.3%), asthma (449/10.6%), COPD (398/9.4%), lipid peroxidation (351/8.3%), apoptosis (343/8.1%), ROS (308/7.2%), macrophage (272/6.4%), glutathione (269/6.3%), cytokine (266/6.3%), cancer (246/5.8%), oxidative damage (232/5.5%), DNA (211/5.0%), catalase (210/4.9%), SOD (206/4.8%), particle (203/4.8%), MDA (189/4.4%), glutathione peroxidase (183/4.3%), airway inflammation (179/4.2%), heme oxygenase (174/4.1%), biomarker (174/4.1%), cigarette smoke (167/3.9%), imbalance (167/3.9%), acute lung injury (166/3.9%), cystic fibrosis (165/3.9%)