Several years ago an “electronic nose” was developed at Linköping University in Sweden. It was based on a number of different gas sensors and programmed to differentiate between various substances in air. This nose is now being joined by a corresponding sensor for fluids, the “electronic tongue.” The principle behind the “electronic tongue” is that a number of electrodes are submerged in the fluid. When a current is turned on across the electrodes the response varies depending on the liquid’s content

Wires one-millionth of a millimetre wide change composition along their length.

Wires one-millionth of a millimetre wide that change chemical composition along their length, just as fruit pastilles change flavour along a packet, have been grown in the United States. These multi-flavoured nanowires can act as miniature bar-codes, diodes and light sources.

Conventional microelectronics components are etched into flat layers of semiconducting material. Charles Lieber and collea

30 years of slowing Pacific circulation may have changed climate

A recent slowing in the circulation of Pacific Ocean waters could have raised Pacific sea surface temperatures. It may even mean that less carbon has reached the atmosphere from the ocean surface over the past two decades.

Across the Pacific, water circulates in two giant loops in the Northern and Southern Hemispheres. It flows from the subtropics to the tropics about at a depth of 100-400 metres, rises to the

Scientists continue to create new uses for carbon nanotubes, those tiny cylinders comprised of pure carbon. A paper published today in the journal Nature describes a thermometer made out of a column of carbon just 10 micrometers long. According to the report, the nanodevice can measure temperatures between 50 and 500 degrees Celsius and “should be suitable for use in a wide variety of microenvironments.”

Yihua Gao and Yoshio Bando of the National Institute for Materials Science in Ibaraki,

Drug leads in protein that sends gut bacteria packing

A protein enables harmful Salmonella bacteria to switch from clinging to our gut lining to swimming off. This get-up-and-go is so crucial to Salmonella’s survival that the protein could prove to be a good target for drugs.

The Salmonella variant Typhimurium causes around 1.4 million cases of food poisoning in the United States each year, and about 1,000 deaths – mainly among infants and the elderly. The bug grips the gut

The information in DNA can be copied into new molecules without proteins’ help.

Chemists have reproduced the basic process of information transfer central to all life without the catalysts that facilitate it in living cells 1 .

They show that DNA alone can pass its message on to subsequent generations. Many researchers believe that DNA-like molecules acted thus to get life started about four billion years ago – before catalytic proteins existed to help DNA t