人体生物钟之谜

人体内有一个独特的生物钟，来适应地球的昼夜变换。它在一天之中的不同时段，对我们的生理功能进行着非常精准的调节，这个生物钟到底是如何工作的？2017年诺贝尔生物学奖获得者们通过分离基因，为我们揭示了到底是什么样的机制使得细胞内的生物钟持续工作。

We spend around a third of our lives like this. 

Sleeping at night and being active during the day is second nature. That's because we're at the mercy of the constant ticking of clocks inside nearly every cell of our bodies. Our mood, strength, hormone levels, body temperature, metabolism and even the risk of a heart attack all fluctuate in a daily rhythm. 

This clock is not controlled by cogs and pendulums. Instead, it's the swing in gene activity over 24 hours that keeps our body's time. The US’s trio Jeffrey Hall, Michael Rosbash and Michael Young found the genes involved. 

Dr Michael Hastings, a circadian rhythm scientist in Cambridge, said it took the discovery for the field to be treated seriously. 

Nobody now doubts the importance of our body clocks. Ask someone who is jet lagged or working shifts what it's like to live out of sync with your internal clock. 

Long-term circadian rhythm disruption is linked to a host of diseases, from cancer to type 2 diabetes, but understanding how the body’s timepiece works is also unlocking new ideas, like taking medicines at the time of day when they will have the biggest impact on the body.