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Coating To Heal Car Scratches

Scientists have developed a polyurethane coating that heals its own scratches when exposed to sunlight, offering the promise of scratch-free cars and other products, researchers said on Thursday. “We developed a polymeric material that is able to repair itself by exposure to the sun,” said Marek Urban of the University of Southern Mississippi in Hattiesburg, whose study appears in the journal Science. “In essence, you create a scratch and that scratch will disappear upon exposure to the sun,” Urban said in an interview on the Science website. The self-healing coating uses chitosan, a substance found in the shells of crabs and shrimp. This is incorporated into traditional polymer materials, such as those used in coatings on cars to protect paint. When a scratch damages the chemical structure, the chitosan responds to ultraviolet light by forming chemical chains that begin bonding with other materials in the substance, eventually smoothing the scratch. The process can take less than an hour.

Urban said the new coating uses readily available materials, offering an advantage over other self-repairing coatings, which he said were “fairly elaborate and economically unfeasible.” The team tested the compound’s properties using a razor-blade-thin scratch. “We haven’t done any of the tests to show how wide it can be,” Urban said in a telephone interview. He said the polymer can only repair itself in the same spot once, and would not work after repeated scratches. “Obviously, this is one of the drawbacks,” he said, adding that the chances are low of having two scratches in exactly the same spot. Howell Edwards, who leads the chemical and forensic sciences division of the University of Bradford in Britain, said the findings were novel. “Clearly, there are future applications of this work in the repair of automotive components, which extensively use polyurethane polymers, that have suffered minor damage,” Edwards said in a statement. Urban said the coating could be used in packaging or furniture or anything that requires a high-performance type of coating. “You can dream up anything you desire,” he said. Urban said his team has patents pending on the material and is considering commercialization.

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A step closer to 'synthetic life'

Page last updated at 19:38 GMT, Thursday, 20 August 2009 20:38 UK

By Victoria Gill

Science reporter, BBC News

In what has been described as a step towards the creation of a synthetic cell, scientists have created a new "engineered" strain of bacteria.

A team successfully transferred the genome of one type of bacteria into a yeast cell, modified it, and then transplanted into another bacterium.

This paves the way to the creation of a synthetic organism - inserting a human-made genome into a bacterial cell.

The team describe the work in the journal Science.

This advance, the researchers say, overcomes the obstacle of making a new inserted genome work inside a recipient cell.

The experiment was carried out by a team that included scientist J Craig Venter, a leading figure in the controversial field of synthetic biology.

Sanjay Vashee, a researcher at the J Craig Venter Institute in Rockville, Maryland, in the US, was one of the authors.

The resulting cell he and his team created went on to undertake multiple rounds of cell division, to produce a new strain of the modified bacteria.

Dr Vashee explained to BBC News that the work overcame a hurdle in the quest to create a fully synthetic organism.

"Bacteria have 'immune' systems that protect them from foreign DNA such as those from viruses," he explained.

He and his colleagues managed to disable this immune system, which consists of proteins called restriction enzymes that home in on specific sections of DNA and chop up the genome at these points.

Bacteria can shield their own genomes from this process by attaching chemical units called methyl groups at the points which the restriction enzymes attack.

The scientists modified the original genome of the bacterium Mycoplasma mycoides, whilst it was inside the yeast cell. Then they either attached methyl groups to it, or inactivated the restriction enzyme of the recipient bacterium, before transplanting the genome into its new cell.

One of the team's ultimate aims is to transplant a fully synthetic genome into a bacterial cell - creating bacteria that can be programmed to carry out specific functions - for example, digesting biological material to produce fuel.

Race for life

Researchers at the same institute have already synthesised the complete genome of a bacterium they have called Mycoplasma genitalium. Dr Vashee described this work as a "logical extension" of that.

He told BBC News that attempts to create a synthetic bacterium by transplanting M. genitalium into a cell were "ongoing".

"We have as of yet no conclusive proof that we have obtained M. genitalium cells after its genome has been put into various recipient cells," he said.

"[but this] is a major advance in our effort to create a synthetic cell."

Dr Vashee continued: "We were very concerned that the differences between the modifications in... bacterial DNA and [yeast] DNA might be an insurmountable barrier, preventing transplantation into bacteria of genomes that were passed through yeast.

"Now we know how to do this."

Critics have expressed reservations about synthetic biology, and the aim to create what has been widely referred to as artificial life.

Many are concerned that the technology to engineer organisms could end up in the wrong hands.

Dr Vashee concluded: "Dr Venter and the team at JCVI continue to work with bioethicists, outside policy groups, [politicians], and the public to encourage discussion and understanding about the societal implications of their work and the field of synthetic genomics."

Wikipedia article on Synthetic Biology.

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More Efficient Solar Cells with Carbon Nanotubes

Silicon is one of the basic but expensive materials used in designing solar panels. If we can use something else as effective as silicon but more economical, solar power will be within the reach of the common consumers. Cornell researchers are thinking on somewhat similar lines. They are using a carbon nanotube instead of traditional silicon that hopefully will lead to much more efficient ways of converting light to electricity.

The researchers extracted a simple solar cell known as photodiode and fabricated, tested and measured this photodiode. The specialty of this photodiode is it is made up of an individual carbon nanotube. Paul McEuen, the Goldwin Smith Professor of Physics, and Jiwoong Park, assistant professor of chemistry and chemical biology take pride in their work and elaborate about the device their team has prepared under their leadership. They explained that their device transforms light into electricity in an exceptionally efficient process that multiplies the amount of electrical current that flows. This process could leave its mark for next-generation high efficiency solar cells.

Nathan Gabor who is a graduate student in McEuen’s lab, says, “We are not only looking at a new material, but we actually put it into an application — a true solar cell device.”

The researchers utilized a rolled-up sheet of grapheme to create their solar cell. They designed a single-walled carbon nanotube from grapheme. The nanotube was about the size of a DNA molecule. The nanotube was wired between two electrical contacts and close to two electrical gates, one negatively and one positively charged. Other scientists too had created a diode, which is a simple transistor that allows current to flow in only one direction. They too had utilized a single-walled nanotube. The Cornell team went ahead with the basic idea but with a twist. They built something similar, but this time threw light on it. They threw lasers of different colors onto different areas of the nanotube. They were in for a pleasant surprise. They discovered that higher levels of photon energy had a multiplying effect on how much electrical current was produced.

How did this desirable event happen to the research team? When they gave their consideration to the whole event they discovered that the narrow, cylindrical structure of the carbon nanotube forced the electrons to be neatly squeezed through one by one. The electrons running through the nanotube became excited and created new electrons that continued to form a stream. The research team thinks that the nanotube might be a nearly ideal photovoltaic cell because it permitted electrons to produce more electrons by making use of the spare energy from the light.

If we compare carbon nanotubes with the current cells we will find that the latter in fact loses the extra energy as heat. So the conventional cells need cooling factors to function properly. Work is going on for the carbon nanotube but to produce it on commercial scale will still be challenging. The team has just been successful on the theoretical and conceptual fronts only.

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Mad scientists, hoping to someday rewrite your memories with frickin' "lasers", are now practicing on flies

Bad memories written with lasers

By Victoria Gill

Science reporter, BBC News

Page last updated at 14:05 GMT, Friday, 16 October 2009 15:05 UK

Laser-controlled flies may be the latest addition to the neuroscientist's tool kit, thanks to a new technique.

Researchers have devised a way to write memories onto the brains of flies, revealing which brain cells are involved in making bad memories.

The researchers said that in flies just 12 brain cells were responsible for what is known as "associative learning".

They describe their findings in the journal Cell.

Associative memories are made when an animal learns to link a cue to a particular outcome. It might for example learn that a certain odour is a sign that a predator is nearby.

"So the appearance of that odour predicts that something bad is going to happen," explained Gero Miesenbock from the University of Oxford, UK, who led this study.

Previous research had already identified that the brain cells or neurons responsible for this type of learning are those that produce dopamine. This is a chemical which acts as a signal that can be transmitted from cell to cell in the brain.

Professor Miesenbock and his team "tapped into these gene regulatory mechanisms" of the neurons - programming them to respond to a laser.

They modified the neurons by adding a sort of trigger, or receptor, to each one. This receptor was activated by a chemical called ATP.

"Since there's no ATP floating around in the fly's brain, the [modified] receptors remain closed and the flies behave just like normal flies that don't have the receptor," said Professor Miesenbock.

Now for the laser-activated trickery.

The scientists injected ATP into the flies' brains, in a form that was locked inside a light-sensitive chemical cage.

"[Then] we turned on the laser light and the light sensitive cage fell apart," Professor Miesenbock explained. "The ATP was released and acted only on the cells [with] the receptor."

Memory circuit

The laser flash was paired with an odour, which allowed the scientists to find out if their memory-writing experiment had been successful.

They gave the flies a simple choice between two odours - one of which the flies had been exposed to just before the laser flash.

"[The flies] moved along a narrow chamber and at the midpoint they were presented with an odour on the left and an odour on the right," said Professor Miesenbock.

He knew that the laser had successfully written a bad memory into the fly's brain when the insect avoided the odour that had been paired with the laser flash.

The flies associated the smell with a bad experience, so the laser flash gave the fly a memory of a bad experience that it never actually had.

Simply by looking inside the flies' brains with a microscope, the researchers were able to narrow this memory formation process down to just 12 neurons.

"We labelled the cells .... that were made responsive to light and which ones were not, so by elimination we could narrow it down."

This finding, said Professor Miesenbock, has begun to unravel how animals and humans learn from mistakes and how "error signals" drive animals to adapt their behaviour.

"In the fly we have isolated and manipulated these error signals, so what we can now do is try to understand how these signals are calculated in the brain and how this works mechanistically.

"I have every expectation that the fundamental mechanisms that produce these error signals are the same in the brain of the fly as they are in the brain of the human.

David Shepherd, a neuroscientist from the University of Bangor in North Wales described the study as "a fantastic piece of work".

Professor Shepherd, who was not involved in this study, told BBC News: "We have known for years that flies are capable of sophisticated behaviours such as learning and memory. We have also been able to manipulate gene and cell function in flies.

"This work combines these elements to make a real breakthrough in our understanding of how memories are formed."

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Fricking Lightning Guns

Dec. 17) -- In Greek mythology, it was a weapon of war. Now the U.S. military is looking to tame lightning, which remains one of nature's most confounding -- and feared -- phenomena.

The Defense Advanced Research Projects Agency, the R&D arm of the Pentagon, has embarked on a project called NIMBUS, which seeks to understand the underlying mechanisms of lightning. "Although significant progress has been made in recent years in our understanding of the lightning discharge and related phenomena, fundamental questions remain unanswered," the agency said in an announcement released today.

Lightning has long perplexed scientists. Not only are atmospheric scientists unsure of exactly what initiates lightning, but they also don't understand precisely how and why it is able to propagate over great distances, and where it will strike. That makes it, in DARPA's view, "one of the major unsolved mysteries in the atmospheric sciences."

The fanciful-sounding NIMBUS project has a serious goal: curbing the $5 billion in damage that lightning strikes cause each year. Lightning is not only little understood, it is dangerous and destructive -- strikes cause more than $5 billion in damages annually, according to the Lightning Safety Institute. NIMBUS will look at ways to protect against that destruction, including attempting to direct where lightning strikes. The initiative also includes plans to try to trigger lightning using rockets, which could be used to model and study the discharges.

This by no means is the military's first foray into lightning research. Pentagon officials have in the past expressed interest in other enigmatic phenomena associated with lightning, such as so-called ball lightning. Though its existence is disputed, ball lightning is purported to manifest itself as luminous, energetic spheres during storms.

The Pentagon has even funded modest efforts looking at whether ball lightning could be used as a weapon.

Another, somewhat more straightforward application of lightning, not mentioned as part of the DARPA project, is the possibility of creating a "lightning gun" -- a weapon that shoots bolts of electricity. In fact, the Defense Department has funded work in this area. A Tuscon, Ariz., company called Applied Energetics (formerly Ionatron) has received a number of multimillion-dollar contracts from the Army and Navy to develop a lightning weapon that uses ultra-short laser pulses to channel electrostatic discharges. Another company, Xtreme Alternative Defense Systems, in Anderson, Ind., has built a prototype of a lightning gun, named StunStrike.

But don't look to NIMBUS to yield a deployable death ray. DARPA says the project has a more benign goal: the protection of people and assets.

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In December 2009, the Science Channel began a new show, Sci-Fi Science, hosted by Michio Kaku. He takes sci-fi concepts -- existence of & travel to parallel universes, teleportation, invisibility, FTL travel, sentient/sapient robots, etc. -- and sees how close we are to really having them.

Last week's ep, he made a Super Hero Suit, with:

* Super-Strength (via two types of artificial muscles, some made from a memory metal powered by alcohol fumes [the inventor must've been a Futurama fan], and some made from carbon nanotubes),

* Protection (carbon nanofiber),

* Mind Reading (touch range, via ultra-miniaturized MRI-like devices in the gauntlets),

* Super-Senses (X-ray Vision, and some other vision enhancements, based on lobster eyes), and

* Additional Limbs (two extending from the shoulders, controlled via impulses from the spine which would rewire itself to control them... not unlike Doc Ock)

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At one time I know he made at least the blueprint for a lightsaber-esque device. He reckons we're within forty to fifty years of that, the big issue being battery capacity (nano-carbon layer batteries being the solution here apparently).

That was on one of the eps of this show, too. Funny thing is, it looked not unlike the toy lightsabers you see -- the plasma "blade" would be confined by a telescoping ceramic composite... thingy, like the telescoping plastic "blade" of a toy lightsaber.

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Would it leave one side open? Or would the ceramic be hot enough to cut something? How would it have a cutting edge if the ceramic (tube?) surrounds the light beam?

As I recall, the tubes had lots of holes around them, to let the plasma out enough so it could burn/melt anything you wanted, from any angle.

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