1. Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
2. Department of Nuclear Medicine, Chinese PLA General Hospital, Beijing 100853, P. R. China
3. Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, P. R. China
4. Center for Advanced Materials Research, Beijing Normal University at Zhuhai, Zhuhai 519087, P. R. China