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If you’ve been hankering for an intersection of nanomaterials and old spy movie cliches, today’s your day: a gang of researchers in Illinois reckon they’ve found a way to use nanoparticles to make messages that erase themselves after a certain amount of time.

A team at Northwestern University in Evanston, Illinois, coated gold nanoparticles with a layer of hair-like molecules called 4-(11-mercaptoundecanoxy)azobenzene or MUA. When zapped with ultraviolet light, these filaments change their shape and charge distribution, causing the nanoparticles to congregate together and change colour […]

To put this colour-changing ability to good use, the team dispersed the nanoparticles in a gel and sandwiched it between plastic sheets to produce a thin, red film. When Grzybowski and his colleagues shone UV light at the film, either through a patterned mask or using a UV pen, they found they could print a range of images or write words onto the film in just a few seconds.

The colour change is not permanent, however. In the absence of UV light, the MUA gradually reverts to its original shape, allowing the nanoparticles to disperse and the images to disappear.

Your mission, should you choose to accept it, is to work out how many times more expensive and complicated it would be to use this stuff instead of scribbling a note on some rice paper. Or whether the Etch-a-Sketch people will be tempted to build a 2.0 version.

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Achieving longevity

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moai_profileThere always seems to be some intriguing news on progress in extending lifespans, or achieving what Aubrey De Grey calls engineered negligible senescence. From Physorg we have news that a compound called rapamycin, first discovered on Easter Island, can increase the lifespans of laboratory mice:

The University of Texas Health Science Center at San Antonio and two collaborating centers reported that the Easter Island compound – called “rapamycin” after the island’s Polynesian name, Rapa Nui – extended the expected lifespan of middle-aged mice by 28 percent to 38 percent. In human terms, this would be greater than the predicted increase in extra years of life if cancer and heart disease were both cured and prevented.

Protein folding in certain species of bats has been found to lead to an increase in their lifespans:

Asish and colleagues made their discovery by extracting proteins from the livers of two long-lived bat species (Tadarida brasiliensis and Myotis velifer) and young adult mice and exposed them to chemicals known to cause protein misfolding. After examining the proteins, the scientists found that the bat proteins exhibited less damage than those of the mice, indicating that bats have a mechanism for maintaining proper structure under extreme stress.

And finally the curious case of Brooke Greenberg: who is the size of an infant, with the mental capacity of a toddler, but turned 16 in January:

In a recent paper for the journal “Mechanisms of Ageing and Development,” Walker and his co-authors, who include Pakula and All Children’s Hospital (St. Petersburg, Fla.) geneticist Maxine Sutcliffe chronicled a baffling range of inconsistencies in Brooke’s aging process. She still has baby teeth at 16, for instance. And her bone age is estimated to be more like 10 years old.

“There’ve been very minimal changes in Brooke’s brain,” Walker said. “Various parts of her body, rather than all being at the same stage, seem to be disconnected.”

A substantial increase in human lifespans would be a huge, world-changing, medical and technological achievement, but could well lead to many social problems. An excellent exploration of the effects of longevity is Bruce Sterling‘s sublime Holy Fire.

[from Physorg and abcnews][image from anoldent on flickr]

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Eye in the sky – commercial satellites trace Sudanese arms purchases

Europe seen from space at nightWell, maybe ubiquitous global surveillance isn’t all bad. Remember that big load of tanks and armaments that Somalian pirates scored from a Ukranian cargo ship and subsequently ransomed back? Well, two magazine reporters used commercial imaging satellites to chase down their final destination, proving in the process that they were en route to the breakaway government of South Sudan:

Images captured by DigitalGlobe satellites in March 2009 showed 33 tanks parked at Kahawa Barracks northeast of Nairobi. In parallel, satellite imagery captured from southern Sudan showed tracked vehicles, parked under camouflage, at a Sudan People’s Liberation Army (SPLA) compound northeast of Juba, the capital of South Sudan. Jane’s observed that SPLA attempts to conceal the location “were deliberate and masterful, but dimensional analysis, tracked-vehicle scarring and the staging of three vehicles in a tactical perimeter established the concealed vehicles as tanks.”

It’s not particularly good news – governments tooling up for nasty regional conflicts never is – but it’s the sort of news we’re better off having than not. Maybe the UN should be funding more similar satellites so as to keep an eye on governments who are somewhat economical with the truth about their military build-ups? [image by woodleywonderworks]

Maybe we could use them to keep Obama and Medvedev honest with regards to their nuclear disarmament agreement… provided the whole thing isn’t a carefully orchestrated publicity play in the first place, natch.

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Mono-molecular optical transistor brings quantum computing closer

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Researchers at the Swiss Federal Institute of Technology have managed to make an optical transistor from a single molecule, offering another potential stay of execution for Moore’s Law.

ETH’s Martin Pototschnig told us more about the molecule used for the experiments. “It is a small hydrocarbon molecule called dibenzanthanthrene (DBATT). The molecules are doped in n-tetradecane, an organic solvent. So the sample is a pink liquid at room temperature. Then we cryogenically cool the small portion of the sample then the n-tetradecane freezes and forms a molecular crystal.”

The molecule itself is about 2 nanometers in size, over ten times smaller than standard transistors, which means that a lot more could be integrated in a single chip.

Great, you may be thinking, but what is it good for? Well, not much. Yet.

By using a laser beam to impose the quantum state of a molecular transistor, the research team demonstrated control of a second laser beam, which reflects the way in which a conventional transistor works.

“The next step is to ‘connect’ two or more [single-molecule optical transistors],” Pototschnig told us with regard to future areas the team will be focusing on. “In other words, we have to connect two molecules in a way that the quantum mechanical superposition state of each molecule is exchanged in a coherent manner. Only that way the strength of the quantum computing principles can be fully taken advantage of. We are in the middle of coming up with actual ways to implement the connection idea.”

Doesn’t really explain much, but then I don’t really fully understand how quantum computing is meant to work, despite numerous attempts to research it a bit further… if anyone can point me towards a good simplified explanation, please pipe up in the comments.

One thing I do know is that a lot of people are skeptical of quantum computing having any practical real-world applications, assuming it ever makes it out of the developmental stages. But then IBM’s chairman of 1943 never imagined the world would need more than five regular computers, and he’s been proved very wrong since then. Human ingenuity being what it is, we’ll find something to do with it once it’s here.

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