Japanese Emperor Naruhito visits a medical research center in London,Japanese Head Naruhito visited one of England's top clinical examination focuses on Wednesday as the second day of a state visit featured the logical and social ties between the nations.The 64-year-old head and his soul mate, Ruler Masako, were welcomed in London on Tuesday by Master Charles III and his life partner, Sovereign Camilla, with a gun salute, a strategic motorcade and a carriage ride to Buckingham Palace, before a state dinner.