1 Department of Radiation Disaster Medicine, Division of Radiation Medical Science, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan. Electronic address: hirohasi@hiroshima-u.ac.jp.
2 Department of Emergency and Critical Care Medicine, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan.
3 Intensive Care Unit, Jikei University Hospital, Tokyo, Japan.