1. Department of Orthopaedics Xijing Hospital Fourth Military Medical University Xi'an 710032 P. R. China
2. Department of Neurosurgery The Second Affiliated Hospital of Xi'an Jiao Tong University Xi'an 710032 P. R. China
3. School of Ecology and Environment Northwestern Polytechnical University Xi'an 710072 P. R. China
4. Department of Thoracic Surgery The Second Affiliated Hospital of Xi'an Jiao Tong University Xi'an 710032 P. R. China
5. Department of Cell Biology School of Medicine Northwest University Xi'an 710032 P. R. China
6. State Key Laboratory of Military Stomatology National Clinical Research Center for Oral Diseases Shaanxi International Joint Research Center for Oral Diseases Department of Oral Anatomy and Physiology and TMD School of Stomatology the Fourth Military Medical University Xi'an 710032 P. R. China