A COVID-19 state of emergency took effect in seven more prefectures on Friday, with restrictions on business activity aimed at curbing Japan's largest yet wave of infections. Ibaraki, Tochigi, Gunma, Shizuoka, Kyoto, Hyogo and Fukuoka will be under the measure until Sept 12, joining Chiba, Saitama, Tokyo, Kanagawa, Osaka and…