1. Department of Mechanical and Aerospace Engineering, The George Washington University, Washington, District of Columbia.
2. Department of Pharmacology and Physiology, Georgetown University, Washington, District of Columbia.
3. Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey.
4. Department of Biomedical Engineering, The George Washington University, Washington, District of Columbia.
5. Department of Medicine, The George Washington University, Washington, District of Columbia.