A Scots widow who lost her dementia-stricken husband to coronavirus faced further heartbreak after discovering his final wish to donate his brain cannot be fulfilled.Jim Powell was diagnosed with Covid-19 on April 21 after contracting the killer bug in the care home where he lived before tragically passing away a week later.The 74-year-old, who had Alzheimer's disease, had planned to donate his brain to science after reaching an agreement with wife Sally, 73, five years ago.But due to the pandemic, the couple's hopes were dashed with Sally being left unable to fulfil her promise to her dearly-loved husband.Grandad Jim will instead be laid to rest with a small funeral service on Friday.Gran-of-five Sally praised the carers who looked after