1. Department of Cardiac Surgery, Zhongshan Hospital, Fudan University, Shanghai 200032, P. R. China
2. Shanghai Institute of Cardiovascular Disease, Shanghai 200032, P. R. China
3. Department of Cardio-Thoracic Surgery, Affiliated Hospital of Zunyi Medical College, Zunyi 563003, P. R. China
4. Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China