1. University of Alabama at Birmingham, Division of Pulmonary, Allergy and Critical Care Medicine, 215 THT, 1900 University Blvd, Birmingham, AL 35294, USA. mdransfield99@msn.com
2. University of Alabama at Birmingham, Division of Pulmonary, Allergy and Critical Care Medicine, 215 THT, 1900 University Blvd, Birmingham, AL 35294, USA