Acute Radiation SyndromeRadiation InjuriesRadiation Injuries, ExperimentalRadioactive Hazard ReleaseRadiodermatitisRadiation DosageDose-Response Relationship, RadiationSyndromeRadiation-Protective AgentsWhole-Body IrradiationRadiation PneumonitisProctitisRadiation ToleranceLethal Dose 50RadiometryRadiotherapyRadiation, IonizingGamma RaysRadiationRadiation ProtectionRadiation MonitoringDown SyndromeMetabolic Syndrome XMice, Inbred C57BLRadiation Oncology