1. Institute of Biomedical Engineering; Chongqing University of Science and Technology; Chongqing 401331 People's Republic of China
2. Department of Biomedical Engineering; Dalian University of Technology; Dalian Liaoning 116024 People's Republic of China
3. Biosystems and Biomaterials Division; National Institute of Standards and Technology (NIST); Gaithersburg 20899 Maryland
4. Bioengineering College; Chongqing University; Chongqing 400044 People's Republic of China