Science and technology in Argentina Argentina have enjoyed an international respect since the turn of the 1900s, when Dr. Luis Agote devised the first safe and effective means of blood transfusion as well as René Favaloro, who was a pioneer in the improvement of the bypass surgery . Argentina is the Latin American country with the most Nobel Prize laureates; and has three Nobel Prize winners in the sciences: Bernardo Houssay in Physiology or Medicine in 1947, Luis Federico Leloir in Chemistry in 1970, and César Milstein in Physiology or Medicine in 1984. Dr. Domingo Liotta created the first artificial heart in 1969, revolutionizing the
Human artificial chromosome by these vectors not only leads to different expression levels, but the inserts also disrupt the original genome. HACs differ in this regard, as they are entirely separate chromosomes. This separation from existing genetic material assumes that no insertional mutants would arise. This stability and accuracy makes HACs preferable to other methods such as viral vectors, YACs and BACs. HACs allow for delivery of more DNA (including promoters and copy-number variation) than is possible with viral vectors. Yeast artificial chromosomes and bacterial artificial chromosomes were created before human artificial chromosomes, which first appeared in 1997. HACs are useful in expression