1. Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China;
2. Department of Neurosurgery, Beijing Tiantan Hospital and Beijing Neurosurgical Institute, Capital Medical University, Beijing, PR China;
3. Information Center, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China;
4. Department of Clinical Laboratory, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China