[1] Xian Jiaotong Univ, Hosp 1, Dept Gastroenterol, Xian, Shaanxi, Peoples R China
[2] Xian Jiaotong Univ, Hosp 2, Dept Gastroenterol, Xian, Shaanxi, Peoples R China
[3] Xian Jiaotong Univ, Inst Urol, Xian, Shaanxi, Peoples R China
[4] Xian Jiaotong Univ, Key Lab Environm & Genes Related Dis, Xian, Shaanxi, Peoples R China