1. Department of Mechanical Engineering and Materials Science, Duke University, Hudson Hall, Durham, North Carolina 27708
2. Division of Rheumatology and Immunology, Duke University Medical Center, 508 Fulton St, Durham, North Carolina 27707
3. Division of Rheumatology and Immunology, Duke University Medical Center, and Medical Research Service, Durham VA Medical Center, 508 Fulton St, Durham, North Carolina 27707