[1] Cent South Univ, Dept Gen Surg, Xiangya Hosp, Changsha, Hunan, Peoples R China
[2] Univ Calif Davis, Dept Math, Davis, CA USA
[3] Cent South Univ, Dept Oncol, Xiangya Hosp 2, Changsha, Hunan, Peoples R China
[4] Clin Res Ctr Thyroid Dis Hunan Prov, Changsha, Hunan, Peoples R China
[5] Hunan Prov Engn Res Ctr Thyroid & Related Dis Trea, Changsha, Hunan, Peoples R China
[6] Xiangya Hosp, Natl Clin Res Ctr Geriatr Disorders, Changsha, Hunan, Peoples R China