Tokyo stocks opened sharply higher Tuesday, with the Nikkei index surging over 2 percent, as technology shares tracked overnight advances by their U.S. counterparts. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average rose 785.77 points, or 2.24 percent, from Friday to 35,810.77. The broader Topix index was up 44.04 points, or 1.77 percent, at 2,527.34. Japanese financial markets were closed Monday for a national holiday. On the top-tier Prime Market, gainers were led by mining, electric appliance and nonferrous metal issues.