Marie Curie theory of "radioactivity" (a term that she coined), techniques for isolating radioactive isotopes, and the discovery of two elements, polonium and radium. Under her direction, the world's first studies into the treatment of neoplasms were conducted using radioactive isotopes. She founded the Curie Institutes in Paris and in Warsaw, which remain major centres of medical research today. During World War I, she developed mobile radiography units to provide X-ray services to field hospitals. While a French citizen, Marie Skłodowska Curie, who used both surnames, never lost her sense of Polish identity. She taught her daughters the Polish language and took
Marie Curie of Paris decided to retain the chair that had been created for her late husband and to offer it to Marie. She accepted it, hoping to create a world-class laboratory as a tribute to her husband Pierre. She was the first woman to become a professor at the University of Paris. Curie's quest to create a new laboratory did not end with the University of Paris, however. In her later years, she headed the Radium Institute ("Institut du radium", now Curie Institute, "Institut Curie"), a radioactivity laboratory created for her by the Pasteur Institute and the University of Paris. The