1. Division of Endocrinology and Metabolism, Department of Internal Medicine, Huashan Hospital, Fudan University, 12 Wulumuqi Middle Road, 200040, Shanghai, China 2. PET Center, Division of Nuclear Medicine, Huashan Hospital, Fudan University, 518 Wuzhong East Road, 200235, Shanghai, China 3. The Key Laboratory of Molecular Medicine, Ministry of Education and Institute of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China 4. The Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China