Introduction
Chronic obstructive pulmonary disease (COPD) is a common chronic non-communicable disease among the elderly. Its main pathological feature is persistent airflow limitation caused by abnormal alveolar structures and bronchial…

Chronic obstructive pulmonary disease (COPD) is a common chronic non-communicable disease among the elderly. Its main pathological feature is persistent airflow limitation caused by abnormal alveolar structures and bronchial…