Artificial heart valve was later changed to use silicone-coated material. The first implantation of mechanical heart valve to human was performed by Dr. Hufnagel on 11 September 1952, using the valve that he developed. This event accelerated the development of other artificial heart valves. Artificial heart valve An artificial heart valve is a device implanted in the heart of a patient with valvular heart disease. When one of the four heart valves malfunctions, the medical choice may be to replace the natural valve with an artificial valve. This requires open-heart surgery. Valves are integral to the normal physiological functioning of the human heart.
History of the Jews in Argentina 1906 and 1912, some 13,000 Jews immigrated to Argentina every year, mostly from Europe, but also from Morocco and the Ottoman Empire. By 1920, more than 150,000 Jews were living in Argentina. After the death of his son and heir, de Hirsch devoted himself to Jewish philanthropy and alleviating Jewish suffering in Eastern Europe. He developed a plan to bring Jews to Argentina as autonomous agricultural settlers. This meshed with Argentina's campaign to attract immigrants. The 1853 constitution guaranteed religious freedom, and the country had vast, unpopulated land reserves. Under President Domingo F. Sarmiento, a policy of mass immigration was