Complex sentence: Pappworth's teaching of postgraduate students had a profound effect on the Membership of the Royal College of Physicians (MRCP) examination pass rate, and his contact with junior doctors led him to investigate the ethics of medical research on humans.
Split into simpler sentences: Pappworth's teaching of postgraduate students had a profound effect on the Membership of the Royal College of Physicians (MRCP) examination pass rate. His contact with junior doctors led him to investigate the ethics of medical research on humans.