Marie Sklodowska Curie (November 7, 1867 – July 4, 1934) began the science of radioactivity. She is best known as the discoverer of the radioactive elements polonium and radium and as the first woman to win a Nobel prize and first person to win two Nobel prizes, and was also the first woman in France to complete a doctorate. Marie Curie teamed up with her husband, Physics professor Pierre Curie, to conduct research on radioactive substances. They found that the uranium ore, or pitchblende, contained much more radioactivity than could be explained solely by the uranium content. They began the search for the source of the radioactivity and discovered two highly radioactive elements, "radium" and "polonium." The Curies won the 1903 Nobel prize for physics for their discovery. After her husband's death in 1906, Madame Curie continued her work on radioactive elements and won the 1911 Nobel prize for chemistry for isolating radium and studying its chemical properties. In 1914 she helped found the Radium Institute in Paris, and was the Institute's first director. When the first world war broke out, Madame Curie thought X-rays would help to locate bullets and facilitate surgery. It was also important not to move the wounded, so she invented X-ray vans and trained 150 female attendants. For scientists and the public, Curie's radium was a key to a basic change in our understanding of matter and energy. Her work not only influenced the development of fundamental science but also ushered in a new era in medical research and treatment.