[1] Division of Pulmonary, Critical Care and Occupational Medicine, University of Iowa Hospitals and Clinics
[2] Department of Cardiovascular Surgery, University Heart Center Hamburg
[3] Hardin Library for the Health Sciences, University of Iowa Hospitals and Clinics
[4] Division of Pulmonary and Critical Care Medicine, University of Maryland
[5] Department of Thoracic Surgery, Zurich University Hospital
[6] Department of Thoracic Surgery and Lung Transplant Unit, University Hospitals Leuven
[7] Department of Thoracic Surgery, Helios Klinikum Wuppertal - University Hospital Witten/Herdecke
[8] Department of Thoracic Surgery, Medical University of Vienna
[9] Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center
[10] Department of Medicine, University of Iowa Hospitals and Clinics, University of Iowa Hospitals and Clinics
[11] Cardiothoracic Surgery Unit, The Alfred Hospital
[12] Department of Thoracic Surgery and Surgical Endoscopy Ruhrlandklinik, University Clinic Essen Tueschener Weg