Positives
The Curies integrity towards scientific research is a praiseworthy one. They believed that all scientific research belongs to everyone and refused to patent their method of producing radium, which would have made them very wealthy. Pierre's integrity is also what made him stick by his wife's side when they were on to something big, in this case, radiology.
Negatives
Marie Curie was unfortunately too encased in her work and didn't want to admit that her illnesses might be caused by her experiments. She didn't think that her prized work could cause ill to her and thus her death came.