Can sheer willpower keep patients alive in their dying hours?
'Doctor holding elderly lady's hand' [Shutterstock]

Marjorie Severance had lived 91 years, five months, and two weeks when, if you believe such things, she decided she could let herself die. She had completed all of her funeral and memorial service plans. Her finances were set. "Nana," as she was known to her many grandchildren and great-grandchildren, spent the last weeks of her…