1 Division of Cardiology, Duke University Medical Center, Durham, NC.
2 Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD.
3 Division of Pulmonary, Critical Care and Sleep Medicine, UC Davis Medical Center, Sacramento, CA.
4 Division of Cardiology, Emory University School of Medicine, Atlanta, GA.
5 NIH Library, Office of Research Services, Office of the Director, National Institutes of Health, MD.
6 Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD; National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD.
7 Department of Transfusion Medicine, Clinical Center, National Institutes of Health, Bethesda, MD.