1. Department of Computer Science, City University of Hong Kong , Tat Chee Avenue, Kowloon , Hong Kong
2. Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School , MA 02138 , United States
3. Department of Chemistry, City University of Hong Kong , Tat Chee Avenue, Kowloon , Hong Kong
4. Shenzhen Research Institute, City University of Hong Kong , Shenzhen , China