1. Key Laboratory of Particle & Radiation Imaging of Ministry of Education, Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China.
2. Yuquan Hospital, Medical Center, Tsinghua University, Beijing, People's Republic of China.
3. Department of Biological Pharmaceuticals, Beijing University of Chinese Medicine, Beijing, People's Republic of China.
4. Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, Institute of Developmental Biology, School of Life Sciences, Shandong University, Jinan, People's Republic of China.