Twelve years after a first patient was identified as cured of H.I.V., the virus that causes AIDS, a second patient undergoing similar treatment was diagnosed as in long-term remission, according to a New York Times report citing an article in to be published tomorrow in the journal Nature. The report means that a cure for the disease is possible, but several obstacles remain before it can be developed and applied broadly, according to scientists quoted by the Times. The findings are set to be presented at the Conference on Retroviruses and Opportunistic Infections in Seattle, on Tuesday. The successful treatment involved bone-marrow transplants that were given to patients infected with H.I.V.