A cup of
coffee can make a refreshing and cheer up, but also lead to the
sleepless at nights. According to the latest report of the United States
of "daily health news", "Sleep
Medicine" magazine published in the United States a new study, it found
that caffeine only affects "lark" type crowd who accustomed to go to bed
early and get up early, but it did not interfere the people who are
staying up late.
In the new study, Stanford University researchers asked 50 college
students record their caffeine intake condition...