Aristides Leao

Aristides Leão was a renowned Brazilian neurophysiologist of Italian background, university professor, scientist and experimental physicist. He is remembered as the discoverer of the spreading depression, a novel electrophysiological phenomenon that occurs in the cerebral cortex and other neural structures. He also invented the first artificial heart-lung machine in Brazil. He was born in Rio de Janeiro, Brazil, in 1914. He graduated in mathematics and physics from the University of São Paulo in 1943. He was part of a group of young Brazilian physicists who worked under European teachers such as Gleb Wataghin and Giuseppe Occhialini. He travelled to England in 1946 to join the group of Cecil Powell at the University of Bristol. There, he improved the nuclear emulsion used by Powell to study cosmic rays. In 1947, he collaborated with Powell, Occhialini and Hugh Muirhead in the experimental discovery of the pion, a composite subatomic particle made of a quark and an antiquark. He also visited a weather station on top of the Chacaltaya mountain in Bolivia, where he registered more pion decay events. In 1948, he worked with Eugene Gardner at UC Berkeley, where he detected the artificial production of pions in the lab's cyclotron. He was just 24 years old. He returned to Brazil in 1949 and became a professor and researcher at the Federal University of Rio de Janeiro and the Brazilian Center for Physical Research. He was one of the founders of both institutions. He also helped to create the National Council for Scientific and Technological Development (CNPq) and the State University of Campinas (Unicamp). He was a member of the Brazilian Academy of Sciences and published over 200 scientific papers. He received many awards and honors for his contributions to physics and science, such as the Order of Scientific Merit and the Moinho Santista Prize. He died of heart failure in São Paulo, Brazil, at the age of 79.