1. Department of Surgery and Biomedical Engineering; Beckman Laser Institute and Medical Clinic; University of California; Irvine CA 92617 U.S.A
2. Department of Dermatology; Xijing Hospital; Fourth Military Medical University; Xi'an 710032 China
3. Department of Biomedical Engineering; University of California; Irvine CA 92617 U.S.A
4. Department of Dermatology; Brigham and Women's Hospital; Harvard Institute of Medicine; Boston MA 02115 U.S.A