1. Department of Biomedical Engineering, University of Michigan, 1119 Carl A. Gerstacker Building, 2200 Bonisteel Boulevard, Ann Arbor, MI 48109, USA
2. Department of Internal Medicine and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
3. Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
4. Medicine Service, Endocrinology and Metabolism Section, VA Ann Arbor Health Care System, Ann Arbor, MI, USA
5. Department of Surgery, University of Michigan, USA