[1] Mudanjiang Med Univ, Affiliated Hosp 2, Dept Neurol, Mudanjiang 157010, Heilongjiang, Peoples R China
[2] Mudanjiang Med Univ, Affiliated Hosp 2, Dept Resp Med, Mudanjiang 157010, Heilongjiang, Peoples R China
[3] Mudanjiang Med Univ, Affiliated Hosp 2, Dept Gastroenterol, Mudanjiang 157010, Heilongjiang, Peoples R China
[4] Mudanjiang Med Univ, Affiliated HongQi Hosp, Dept Gen Surg, 5 Tongxiang Rd, Mudanjiang 157011, Heilongjiang, Peoples R China