In the 1960s, two Japanese scientists discovered a drug that could prevent maternal deaths. It took decades for them to be proved right.
Many women in the developing world die during childbirth - but a cheap kit containing a condom could save tens of thousands of lives.
The story of Carol Jennings and how her family's uncommon form of Alzheimer's led scientists to a breakthrough in understanding the disease.
Charismatic and controversial, surgeon Christiaan Barnard pioneered human heart transplants - and faced a barrage of criticism.
