1. Theoretical and Applied Mechanics Program, McCormick School of Engineering, Northwestern University, Evanston, Illinois
2. Department of Mechanical Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois
3. Division of Gastroenterology and Hepatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
4. Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
5. Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania