1. Lanzhou University Second Hospital, Lanzhou University, The 940th Hospital of Joint Logistics Support Force of PLA, Lanzhou 730030, Gansu, China
2. School of Stomatology, Lanzhou University, The 940th Hospital of Joint Logistics Support Force of PLA, Lanzhou 730000, Gansu, China
3. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
4. School of Stomatology, Lanzhou University, Lanzhou 730000, Gansu, China