1. Beijing Engineering Research Center for BioNanotechnology and CAS Key Laboratory for Biological Effects of Nanomaterials and NanosafetyCAS Center for Excellence in NanoscienceNational Center for NanoScience and Technology No. 11 Zhongguancun Beiyitiao Beijing 100190 P. R. China
2. Clinical Laboratory of South BuildingChinese P. L. A. General Hospital Beijing 100853 China
3. University of Chinese Academy of Sciences Beijing 100049 P. R. China
4. Current address: Institute of Medical BiologyChinese Academy of Medical Sciences and Peking Union Medical College Kunming Yunnan 650000 P. R. China
5. Current address: Department of Biomedical EngineeringSouthern University of Science and Technology No. 1088 Xueyuan Rd, Nanshan District Shenzhen Guangdong 518055 P. R. China