January 2007


Inspired by a 140-year-old conundrum, chemists have created a nanomachine that works like a ratchet, transporting molecules in only one direction. The device is unusual because it drives the molecules away from their thermodynamic equilibrium, proving that artificial devices can mimic the sophisticated biochemical machinery in every living cell. 

Or some of its secrets. Javier Gonzalez-Maeso at Mount Sinai School of Medicine in New York, and colleagues have thrown new light on the unique psychedelic effects caused by hallucinogens like LSD. It’s a drug that some people think defined an era, though it’s centenarian inventor, Albert Hofmann, is rarely remembered.

Hofmann and LSD molecule. Albert Hofmann Foundation

If you want to find agreement among experts about the best solar cell technology, forget it. There are nearly as many opinions as experts. But most do agree on one key point: that the photovoltaic industry is nearing a breakthrough point, beyond which production capacity will soar, offering consumers a wide variety of options at much lower prices. 

Most animals will steer well clear of poisonous toads belonging to the Bufonidae family. But not so a species of Asian snake, which happily eats them and recycles the toxins to ward off predators of its own.             

Unlucky toad

Accumulating toxic compounds from the diet is a trick that can be pulled off by several invertebrates and a few frogs. But it’s very rare for vertebrates to sequester toxins from their food, especially from vertebrate prey, says Deborah Hutchinson of the Old Dominion University in Norfold, Virginia, US.

Now she and her colleagues have demonstrated that the Japanese colubrid snake Rhabdophis tigrinus is getting its bufadienolides by snaffling up toads. For most would-be predators these are dangerous compounds, bringing the heart to a sudden halt by inhibiting the membrane-bound sodium/potassium pump.

UK pharmaceutical giant GlaxoSmithKline, which has spent the past few years fighting off accusations of risks associated with its market-leading antidepressant Seroxat, has rejected fresh claims that it improperly withheld medical trial information in the 1990s. 

The BBC’s claim is that GSK had told drugs reps in 2001 that Seroxat demonstrated ‘remarkable efficacy and safety in the treatment of adolescent depression’. This followed clinical trials that had shown the reverse.

American researchers have used hydrogels to control the flow of liquid in microfluidic devices. They made hydrogel plugs that change size to control the flow within a network of channels.

Hydrogels are jelly-like polymers that swell when wetted and have been used to provide actuation for valve and pumps in microfluidic systems.

Not one for hayfever sufferers, perhaps. Researchers are touting pollen capsules filled with nanomaterials as drug delivery vehicles.

US scientists have built a device capable of detecting masses as small as 1 attogram (1 x 10-18 g) at ambient temperature and pressure. This sets a new record for detection under these conditions, they claim. Previous devices have required high vacuum and low temperature in order to achieve comparable sensitivity.

Canadian researchers have come to the surprising conclusion that nematode worms can be taught to solve mazes.

The worm that turned 

How useful that is remains to be seen. But, says one of the researchers, ’the fun of nematode worms is the challenge they offer a creature with billions of neurons (us) to come up with clever experiments like this to see what worms can do with only 302 neurons!’

This research might represent a breakthrough in x-ray imaging. A new technique means x-ray microscopes could be used to picture individual atoms in living cells without using a lens.

Now a lot of work has already been done on lensless x-ray imaging, but the scientists claim their method marks significant progress towards the ‘ultimate microscope’, with the potential to reach the greatest resolution allowed by an x-ray’s wavelength: a span of around 0.1 nanometres, roughly the width of a carbon atom. They’ve not got there yet, but that sounds pretty impressive to me…

 

 

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