1. Department of Mechanical EngineeringJohns Hopkins University Baltimore MD 21218 USA
2. Key Laboratory of Opto Electronic Science and Technology for Medicine of Ministry of EducationFujian Provincial Key Laboratory of Photonics TechnologyFujian Normal University Fuzhou 350007 P. R. China
3. Department of ChemistryIndian Institute of Technology Delhi Hauz Khas New Delhi 110016 India
4. Department of PathologyJohns Hopkins University School of Medicine Baltimore MD 21287 USA
5. Department of Laboratory Medicine and PathologyMayo Clinic Rochester MN 55906 USA
6. Department of OncologyThe Johns Hopkins University School of Medicine Baltimore MD 21205 USA
7. The Russell H. Morgan Department of Radiology and Radiological ScienceThe Johns Hopkins University School of Medicine Baltimore MD 21205 USA