1. Department of Pathology, Immunology and Laboratory Medicine, and Department of Pediatrics, College of Medicine, University of Florida, Gainesville, FL 32610, USA.
2. University of Florida Diabetes Institute, University of Florida, Gainesville, FL 32610, USA.
3. Barbara Davis Center for Diabetes, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO 80045, USA.
4. Department of Biomedical Engineering, College of Engineering, University of Florida, Gainesville, FL 32610, USA.