1. National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, China
2. Jiangsu Advanced Textile Engineering Technology Center, Nantong 226007, China
3. Department of Applied Physics, The Hong Kong Polytechnic University, 11 Yukchoi Rd., Hung Hom, Kowloon 10087, Hong Kong, P. R. China
4. Department of Urology, The First Affiliated Hospital of Soochow University, Suzhou 215006, China