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 the Nobel Prize in Physics, "in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel." At first the committee had intended to honor only Pierre Curie and Henri Becquerel, but a committee member and advocate for women scientists, Swedish mathematician Magnus Goesta Mittag-Leffler, alerted Pierre to the situation, and after his complaint, Marie's name was added to the nomination. Marie Curie was the first woman to be awarded a Nobel Prize. Curie and her husband declined to go to Stockholm to receive the prize in person; they were