Can you be alive but be dead at the same time?

Yes, if you include someone who is "brain-dead" . This would be synonymous with a vegetative state, where a persons vital functions of circulation and respiration are maintained by the medulla oblongata. Higher thinking functions and awareness controlled by the cerebral cortex is missing. Unlike someone in a coma, consciousness and self awareness beyond simple reaction to environmental stimuli do not return in a person in this state. Also, individuals in drowning situations where hypothermia lowers body temperature have been resuscitated even after an hour underwater , since lower temperatures have prevented oxidative processes from degrading the tissues.