1. Department of Biochemistry, Duke University, Durham, North Carolina, USA
2. Department of Radiology, Duke University, Durham, North Carolina, USA
3. Duke University NMR Center, Duke University Medical Center, Durham, North Carolina, USA
4. Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
5. Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA