Tokyo stocks opened slightly higher Friday as investor sentiment improved after the U.S. Dow index ended at a record high overnight, but falling technology shares weighed on the market. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average rose 27.47 points, or 0.07 percent, from Thursday to 38,390.00. The broader Topix index was up 7.81 points, or 0.29 percent, at 2,700.83. On the top-tier Prime Market, gainers were led by nonferrous metal, electric power and gas, and marine transportation issues. At 9 a.m., the dollar fetched 144.89-90 yen compared with 144.94-145.04 yen in …