Cunning Plumbing

摘要

Gerhard hummer was pondering a serious plumbing problem. He was try ing to unravel the inner workings of tiny proteins called aquaporins, which are found in the walls of living cells. Each aquaporin is threaded by a narrow pore that helps control the flow of water into the cell. The pore is a complex thing, narrow in parts and wide in others, lined with a variety of chemical groups that mostly repel water. But it is basically a pipe.rnAnd that realisation made Hummer, working at the US National Institutes of Health in Bethesda, Maryland, turn his attention to carbon nanotubes. Consisting of curled-up sheets of carbon and just nanometres wide, they are essentially smooth pipes of water-repelling graphite. Hummer hoped that their simple structure might offer new insights into the way that water travels through aquaporins.