"Maybe the reason why free radicals and aging are correlated is because free radical production in the mitochondria (part of the cell) is a stress reaction to the damage of aging," Hekimi said.

海克米说：“人们之所以把自由基和衰老联系在一起，可能是因为自由基在线粒体(细胞的一部分)中产生是人体对衰老的应激反应。”

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If the stress of aging or disease increases sufficiently, he said, the damage caused by the free radicals might overwhelm their positive effects.

如果衰老或疾病过程中的应激大幅增加的话，自由基的破坏作用可能就会大于其积极作用。

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To simulate aging, the same bees were then placed in plastic tubes and exposed to a high-oxygen environment, a metabolic stress test.

为模拟老化，把条件相同的蜜蜂放在塑胶管中，暴露于高氧环境进行代谢性应激试验。

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