1. Graduate School of Ningxia Medical University; Yinchuan China
2. National Engineering Research Center for Beijing Biochip Technology; Sub-center in Ningxia; General Hospital of Ningxia Medical University; Yinchuan China
3. Department of Epidemiology and Biostatistics; School of Public Health; Ningxia Medical University; Yinchuan China
4. Health Examination Center; General Hospital of Ningxia Medical University; Yinchuan; China