1. Department of GynecologyThe First Hospital of Jilin UniversityChangchun 130021 P. R. China
2. Department of Respiratory, China‐Japan Union HospitalJilin UniversityChangchun 130021 P. R. China
3. The First People's Hospital of TianmenTianmen Hubei 431700 P. R. China
4. Physical Examination Center, China‐Japan Union HospitalJilin UniversityChangchun 130031 P. R. China