These effects were probably the result of some biochemical changes Dr Dunlap saw in the treated ewes.

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Certain diseases, such as cancers, will induce biochemical changes in the body such as changes in the balance of molecules that it produces.

ECONOMIST: A biological computer diagnoses and treats cancer

The same biochemical changes took place in the brains of mice, and the mice in question were far less active than untreated mice.

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He carried the baton a bit farther by looking at the biochemical changes involved in the formation of memory first (because such experiments are unethical in people) in sea slugs, and then in mice.

ECONOMIST: The Nobel prizes

Instead of today's crude tools, the new gene-derived tests will help doctors spot tiny biochemical changes deep inside the body that presage the onset of myriad cancers, heart failure and other ills before symptoms appear.

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As the brain grows older, it undergoes complex and poorly understood changes from the biochemical, to the molecular, structural and functional that lead it to shrink.

ECONOMIST: The ageing brain