[1] Hebei Med Univ, Dept Anesthesiol, Hosp 2, 215 HePing West Rd, Shijiazhuang 050000, Peoples R China
[2] Hebei Univ, Affiliated Hosp, Dept Anesthesiol, Baoding 071000, Peoples R China
[3] Hebei Univ, Affiliated Hosp, Dept Thorac Surg, Baoding 071000, Peoples R China
[4] Hebei Med Univ, Electron Microscope Room, Shijiazhuang 050000, Peoples R China
[5] Hebei Univ, Affiliated Hosp, Dept Pathol, Baoding 071000, Peoples R China