 However, the team of Brazilian scientists, including Rocha e Silva, Beraldo, Rosenfeld and Ferreira never came to enjoy the royalties of such discovery, since they always published in the public domain of pure scientific knowledge.Among his many other contributions to biomedical sciences are the development of a rapid staining for blood smears combining May–Grunwald and Giemsa techniques in 1947 (Rosenfeld staining), the introduction a new treatment for chronic leukemia using personal control of maintenance dosis (1955) and described hementerin, an anticoagulant isolated of a Brazilian species of leech ("Haementeria depressa") jointly with Eva Maria Antonia Kelen in 1975.Dr.