The Nikkei stock index on Tuesday ended above the 70,000 line for the first time since early July as optimism about artificial intelligence- and semiconductor-related shares boosted investor sentiment.The 225-issue Nikkei Stock Average ended up 737.12 points, or 1.05 percent, from Monday at 70,683.98. The broader Topix index finished 38.34 points, or 0.92 percent, higher at 4,183.56.On the top-tier Prime Market, the main gainers were nonferrous metal, precision instrument and insurance issues.The U.S. dollar strengthened to the lower 158 yen range in Tokyo, amid speculation that the interes…READ FULL ARTICLE