What will happen if PHD doctor in any field lost his work and research on his dead hard what you will do to get information back ?

Is the hdd is not working at all and you have to get the data back in any cost. Then there is one option. You have to go to any company which provide data recovery. They can recover your data by placing HDD's disk to another working HDD's disk or just simply by replacing HDD's board. If they cost enough as much as new hdd cost then do it yourself by getting old/used working hdd with same capacity and brand model. First try by replacing the board then go with changing disk to another disks. (Last option will require skills to do that in zero dust particle environment)

I am sure that every research work must have documented in papers from very first day when a person started his PHD thesis and he/she mush maintained a record of his work and finally he/she submitted these documents in front of a authority or institution who award him/her PDD degree on this basis.  So, we never lost any PDH work or research in that case.

In air tight isolation room replace the failed mechanical parts and retreive the data.

Hello, this can be achieved if the stability of the human life path is achieved by cleaning the professional through the DNA in question and the various memory files to re-create artificial insemination to restore the creation and achieve the conditions established by the deceased and monitor the path to extract the facts and scientific research and other things