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These creatures served as inspiration for a new dry adhesive tape that not only boasts impressive bonding strength, but can also be attached and detached thousands of times without losing its adhesive properties.

The secret to the wall climbing ability of many insects and geckos lies in the thousands of tiny hairs called setae that cover their feet and legs. The sheer abundance of these hairs, coupled with flattened tips that can splay out to maximize contact on even rough surface areas, make it sufficient for the Van der Waals forces, which operate at a molecular level and are relatively weak compared to normal chemical bonds, to provide the requisite adhesive strength that allows them to scurry along walls and ceilings.

It is this technique that the research group, led by Stanislav Gorb, have mimicked with their silicone tape. By patterning the tape with tiny hairs similar to setae, they created a tape that was at least two times harder to pull off of a surface than a flat tape of the same material. Additionally, the bioinspired tape leaves no sticky residue, can also work underwater, and can be repeatedly peeled off thousands of times without losing its ability to grip.

Providing an illustration of the adhesive properties of the new tape, a 20 x 20 cm (7.87 in) square piece was able to support the weight of one team member dangling from the ceiling.

The researchers are also looking to nature in the form of beetle coverwings, snake skin, and anti-adhesive plants, for inspiration for other bioinspired materials.

The University of Kiel team presented their findings at the AVS Symposium held in Nashville earlier this month.

Source: GizMag

 

The molecule has four branches that act as wheels, rotating when a tiny metal tip applied a small current to them.

With 10 electric bursts, the car was made to move six billionths of a metre.

The approach, published in Nature, joins recent single-molecule efforts, and seems to overcome the forces that often dominate at such tiny scales.

The "batteries" of the electric car come by way of the tip of what is called a scanning tunnelling microscope - an extraordinarily fine point of metal that ends in just an atom or two. As the tip draws near the molecule, electrons jump into it.

The motor of the approach lies with the four "molecular rotors" that act as the car's wheels; they undergo a change in shape when they absorb the electrons.

The demonstration is a tour de force in what is called "bottom-up" nanotechnology. A wide array of machines has been demonstrated in recent years, incorporating parts etched to minuscule sizes from chunks of metals or semiconductors - a small version of traditional, "top-down" manufacturing.

As the chemical groups in each "wheel" change shape, the car inches ahead

Building up from single, designed molecules is another matter, said Tibor Kudernac, a chemist now at the University of Twente, the Netherlands, and lead author of the paper.

"If you look around, in all biological systems are a vast number of molecular machines or rotors based on proteins that do important things very well; muscle contraction is based on protein motors," he explained.

"This is a simple demonstration that we can achieve anything like that. It's an important observation and I think it will motivate people to think about it perhaps a bit more from an application point of view."

Dr Kudernac concedes that applications for molecular machines like the car are probably far in the future. The first task, he said, was to make it work under normal conditions; the current work has been done at a blisteringly cold -266C and in a high vacuum.

And although each potential application will require a newly designed molecular machine, Dr Kudernac remains confident.

"There are ways to play around," he said. "That's what we chemists do - we try to design molecules for particular purposes, and I don't see any fundamental limitations."

Source: BBC

 
By Admin (from 21/01/2012 @ 14:06:33, in en - Science and Society, read 2339 times)

The World Diabetes Foundation estimated that some 285 million people, or around 6 percent of the world's adult population, were living with diabetes in 2010. For type 1 diabetics and up to 27 percent of type 2 diabetics, that means daily insulin injections, which can be uncomfortable and inconvenient. Since most people would rather pop a pill than get a shot, researchers have been trying to develop an oral form of insulin. However, this has proven difficult because insulin is a protein that is broken down in the stomach and gut. Now a team of researchers from Australia's Curtin University has found an insulin substitute to treat diabetes orally that they hope could help take the needle out of diabetes for many people.

In an effort to find a compound that emulates the molecular map of insulin, Professor Erik Helmerhorst and his colleagues at Curtin University in research undertaken with Australian pharmaceutical company Epichem searched the structures of three million compounds.

"We took a 3D molecular map of insulin and identified the key features within this map that are needed for insulin's activity," Prof. Helmerhorst told Gizmag. "We then searched over 3 million small molecules 3D structures for their ability to fit the key features within this insulin map. We found a lead drug molecule that fitted the map and mimicked insulin in specific biological assays and animal models. We have already spent nearly 10 years optimizing this lead molecule."

Unlike insulin, the small drug molecule isn't broken down in the stomach so can be taken orally as a tablet. As well as appealing to people who aren't fond of needles, Prof. Helmerhorst says a tablet would also be cheaper to produce and easier to store than insulin. This would make it easier to distribute in developing countries where the rates of diabetes are on the rise.

Although Prof. Helmerhorst says the insulin substitute could potentially replace the need for injections for sufferers of both type 1 and type 2 diabetes, because type 1 diabetics depend on insulin for their survival, the researchers plan to initially target type 2 diabetics prior to them developing full insulin dependency.

The research is still in the lead optimization stage with clinical trials not expected to begin for another five years or so. Looking for licensees to market the insulin substitute and investors to fund the next stage of development, the Curtin University team recently presented their research and generated a lot of interest at Univation 2011, which aims to showcase research being developed at West Australia's universities to potential investors.

Source: GIZMAG

 

The success of the project to create a 're-programmable cell' could revolutionise synthetic biology and would pave the way for scientists to create completely new and useful forms of life using a relatively hassle-free approach.

Professor Natalio Krasnogor of the University's School of Computer Science, who leads the Interdisciplinary Computing and Complex Systems Research Group, said: "We are looking at creating a cell's equivalent to a computer operating system in such a way that a given group of cells could be seamlessly re-programmed to perform any function without needing to modifying its hardware."

"We are talking about a highly ambitious goal leading to a fundamental breakthrough that will, -- ultimately, allow us to rapidly prototype, implement and deploy living entities that are completely new and do not appear in nature, adapting them so they perform new useful functions."

The game-changing technology could substantially accelerate Synthetic Biology research and development, which has been linked to myriad applications -- from the creation of new sources of food and environmental solutions to a host of new medical breakthroughs such as drugs tailored to individual patients and the growth of new organs for transplant patients.

The multi-disciplinary project, funded with a leadership fellowship for Professor Krasnogor worth more than Ł1 million from the Engineering and Physical Sciences Research Council (EPSRC), involves computer scientists, biologists and chemists from Nottingham as well as academic colleagues at other universities in Scotland, the US, Spain and Israel.

The project -- Towards a Biological Cell Operating System (AUdACiOuS) -- is attempting to go beyond systems biology -- the science behind understanding how living organisms work -- to give scientists the power to create biological systems. The scientists will start the work by attempting to make e.coli bacteria much more easy to program.

Professor Krasnogor added: "This EPSRC Leadership Fellowship will allow me to transfer my expertise in Computer Science and informatics into the wet lab.

"Currently, each time we need a cell that will perform a certain new function we have to recreate it from scratch which is a long and laborious process. Most people think all we have to do to modify behaviour is to modify a cell's DNA but it's not as simple as that -- we usually find we get the wrong behaviour and then we are back to square one. If we succeed with this AUdACiOuS project, in five years time, we will be programming bacterial cells in the computer and compiling and storing its program into these new cells so they can readily execute them.

"Like for a computer, we are trying to create a basic operating system for a biological cell."

Among the most fundamental challenges facing the scientists will be developing new computer models that more accurately predict the behaviour of cells in the laboratory.

Scientists can already programme individual cells to complete certain tasks but scaling up to create a larger organism is trickier.

The creation of more sophisticated computer modelling programmes and a cell that could be re-programmed to fulfil any function without having to go back to the drawing board each time could largely remove the trial and error approach currently taken and allow synthetic biology research to take a significant leap forward.

The technology could be used in a whole range of applications where being able to modify the behaviour of organisms could be advantageous. In the long run, this includes the creation of new microorganisms that could help to clean the environment for example by capturing carbon from the burning of fossil fuel or removing contaminants, e.g. arsenic from water sources. Alternatively, the efficacy of medicine could be improved by tailoring it to specific patients to maximise the effect of the drugs and to reduce any harmful side effects.

Source: University of Nottingham

 

Oliver Brunt, a Design for Industry student, is competing in London against five fellow finalists hoping to win the Autocar-Courland Next Generation Award 2011 – an annual competition that aims to identify, support and develop automotive talent of the future.

The 21-year-old has designed the Social Heads Up Display (SHUD) System. The concept uses the 3G phone network and Bluetooth to enable cars to share information about speed, direction and location in order to give other road users prior knowledge of incoming traffic and accident hotspots. The information is displayed on the windscreen, rather than as a potentially distracting dashboard alert, using Organic Light Emitting Diode (OLED) technology sandwiched between the windscreen glass to display the information on the screen.

Satnav instructions would appear directly on the windscreen with speed zone information highlighted. Music players or mobile phone calling facilitators would be activated via voice command. The aim is to ensure that the driver does not have to take their eyes away from the road at any point in their journey, thus improving safety.

Oliver, originally from Scunthorpe, is currently in contact with various car manufacturers and a German independent OLED screen specialist in the hope of developing the idea into a working prototype. He said: “Combining the SHUD system with the OLED technology could save lives, reduce traffic and decrease in-car driver distractions by eradicating the need to look anywhere else in the car apart from the windows and mirrors.

“The whole idea is built upon existing technology and infrastructure but merges key elements to create a whole new concept that could save lives, time and our environment.”

The Next Generation Award offers entrants a unique chance to launch a coveted industry career and is run in partnership with Courland Automotive and the Society of Motor Manufacturers & Traders. The 2011 award is backed by McLaren Automotive, Mercedes-Benz, Toyota, Peugeot and Skoda.

Open to transportation design students across the country, the competition asked entrants to submit a proposal suggesting some improvement that would be a worthwhile benefit to the automotive business on a small or large scale. Entries were narrowed down to 12 candidates who were selected to attend an assessment day to present their idea to a panel of senior industry executives. Oliver and five other candidates impressed the judges following a series of interviews, professional personality profiling and psychometric tests. A final presentation to a panel of industry insiders will determine the award winner, who will win a placement with a car manufacturer as well as a cash prize.

Kevin Gaskell, Chairman of Courland Automotive Practice, is leading the assessment panel in the competition. He said: “The high calibre of the students we interviewed at the assessment days were very impressive. It was great to see such enthusiastic raw talent and I have no doubt that they all have great careers ahead of them.”

Source: PhysOrg

Provided by Northumbria University

 
By Admin (from 15/01/2012 @ 08:09:12, in en - Science and Society, read 1969 times)

The team of Professor Keon Jae Lee (Department of Materials Science and Engineering, KAIST) has developed fully functional flexible non-volatile resistive random access memory (RRAM) where a memory cell can be randomly accessed, written, and erased on a plastic substrate.

Memory is an essential part in electronic systems, as it is used for data processing, information storage and communication with external devices. Therefore, the development of flexible memory has been a challenge to the realization of flexible electronics.

Although several flexible memory materials have been reported, these devices could not overcome cell-to-cell interference due to their structural and material limitations. In order to solve this problem, switching elements such as transistors must be integrated with the memory elements. Unfortunately, most transistors built on plastic substrates (e.g., organic/oxide transistors) are not capable of achieving the sufficient performance level with which to drive conventional memory. For this reason, random access memory operation on a flexible substrate has not been realized thus far.

Recently, Prof. Lee's research team developed a fully functional flexible memory that is not affected by cell-to-cell interference. They solved the cell-to-cell interference issue by integrating a memristor (a recently spotlighted memory material as next-generation memory elements) with a high-performance single-crystal silicon transistor on flexible substrates. Utilizing these two advanced technologies, they successfully demonstrated that all memory functions in a matrix memory array (writing/reading/erasing) worked perfectly.

Prof. Lee said, "This result represents an exciting technology with the strong potential to realize all flexible electronic systems for the development of a freely bendable and attachable computer in the near future."

This result was published in the October online issue of the Nano Letters ACS journal.

Source: PhysOrg

 

In addition to its renewable energy generating capabilities, the landmark tower would provide an observation deck, meeting space, office space, a museum, and parking. The lace-like skyscraper combines practical mixed use space with the ability to produce an impressive amount of clean power for the city.

Inspiration for the Taiwan tower’s design came from woven bamboo or bamboo scaffolding – a meshed exterior encases all the programmatic elements. The weaving of the structure creates an intricate pattern and a series of voids that offer views of the city.

The gaps between the mesh also provide space to install 600 wind turbines for a total of 6 MW. These small vertical axis wind turbines are quiet and sculptural – as opposed to large, noisy turbines. The landmark tower’s Eddy turbine-studded facade doubles as a power plant that generates energy for the city. Visitors to the landmark tower will enjoy views of the city and cultural events from a building wrapped with renewable energy-generating turbines.

Source: NL Architects & InHabitat

 

Researchers reversed their age-related wrinkles, muscle wasting and cataracts, and it could lead to a fountain of youth for humans, too.

It sounds too wonderful to be true, but it's not science fiction. The researchers, who published their work today in Nature, made the mice youthful by manipulating their "senescent cells," which have retired and stopped dividing. That helps prevent tumors from forming, but they were also suspected of contributing to the ugly side of aging.

To find out whether removing the cells might keep us pretty and healthy as we grow old, the researchers genetically engineered mice to give them the ability to flush away all their senescent cells. And what do you know? Without them, the critters lost their age-related wrinkles (actually loss of skin fat that causes wrinkles, mice don't really get them), cataracts and muscle wasting.

The immune system clears out some of our senescent cells automatically, but not all of them, and they accumulate over time. Up to 10 percent of all cells in really old people are senescent.

It sounds so simple: all we have to do is get rid of our senescent cells for forever youth! But it's not that easy, of course. The scientists suggest developing a drug that could clear the cells, or an immune booster to make the natural process more efficient. But either would take years to develop.

One other caveat: the youthful mice didn't live longer than normal. So if a treatment for humans ever does come to fruition you might not live forever, but at least you'll look marvelous!

Source: GIZMODO

 

They could lead to "superlenses" able to image proteins, viruses and DNA, and perhaps even make a "Star Trek" cloaking device.

Other metamaterials offer unique magnetic properties that could have applications in microelectronics or data storage.

The limitation, so far, is that techniques like electron-beam lithography or atomic sputtering can only create these materials in thin layers. Now Cornell researchers propose an approach from chemistry to self-assemble metamaterials in three dimensions.

Nanomanufacturing technology has enabled scientists to create metamaterials - stuff that never existed in nature - with unusual optical properties. Two polymer molecules linked together will self-assemble into a complex shape, in this case a convoluted "gyroid." One of the polymers is chemically removed, leaving a mold that can be filled with metal. Finally the other polymer is removed, leaving a metal gyroid with features measured in nanometers. Credit: Wiesner Lab

Uli Wiesner, the Spencer T. Olin Professor of Engineering, and colleagues present their idea in the online edition of the journal Angewandte Chemie.

Wiesner's research group offers a method they have pioneered in other fields, using block copolymers to self-assemble 3-D structures with nanoscale features.

A polymer is made up of molecules that chain together to form a solid or semisolid material. A block copolymer is made by joining two polymer molecules at the ends so that when each end chains up with others like itself, the two solids form an interconnected pattern of repeating geometric shapes -- planes, spheres, cylinders or a twisty network called a gyroid. Elements of the repeating pattern can be as small as a few nanometers across. Sometimes tri-polymers can be used to create even more complex shapes.

After the structure has formed, one of the two polymers can be dissolved away, leaving a 3-D mold that can be filled with a metal -- often gold or silver. Then the second polymer is burned away, leaving a porous metal structure.

In their paper the researchers propose to create metal gyroids that allow light to pass through, but are made up of nanoscale features that interact with light, just as the atoms in glass or plastic do. In this way, they say, it should be possible to design materials with a negative index of refraction, that is, materials that bend light in the opposite direction than in an ordinary transparent material.

Special lenses made of such a material could image objects smaller than the wavelength of visible light, including proteins, viruses and DNA. Some experimenters have made such superlenses, but so far none that work in the visible light range. Negative refraction materials might also be configured to bend light around an object -- at least a small one -- and make it invisible.

The Cornell researchers created computer simulations of several different metal gyroids that could be made by copolymer self-assembly, then calculated how light would behave when passing through these materials. They concluded that such materials could have a negative refractive index in the visible and near-infrared range. They noted that the amount of refraction could be controlled by adjusting the size of the repeating features of the metamaterial, which can be done by modifying the chemistry used in self-assembly.

They tried their calculations assuming the metal structures might be made of gold, silver or aluminum, and found that only silver produced satisfactory results.

Could these materials actually be made? According to graduate student Kahyun Hur, lead author on the paper, "We're working on it."

Source: Cornell University

 

This raises the possibility that patients' own stem cells may one day be rescued and banked to treat their age-related diseases.

Stem cells are immature cells that have the potential to convert into bone, muscle, blood vessels, nerve fibers, and other body cells and tissues. It's no wonder medical science seeks to utilize these versatile cells to restore tissues deteriorated by age, disease or injury.

Older stem cells are not as robust as young ones, however — a challenge to clinicians who seek to use patients' own stem cells to treat age-relateddiseases.

"The number and quality of those cells decline with age, that is very clear," said Xiao-Dong Chen, M.D., Ph.D., a stem cell researcher at the UT Health ScienceCenter. "And, using the patient's own cells can impact results."

Dr. Chen's team recently made a discovery in mice that, if translated to humans, could solve this predicament.


Old cells expand when grown on a young scaffold of tissue
Dr. Chen suspected that giving stem cells a youthful environment for growth would cause them to regenerate faster. His team extracted mesenchymal stem cells from the bone marrow of 3-month-old mice and 18-month-old mice. The group also obtained extracellular matrix (ECM) from mice of both ages. ECM is a scaffold of connective tissue, such as collagen, which constitutes a majority of the body's structure.

The lab team seeded half of the older stem cells on ECM from the 3-month-old mice and half on ECM from the 18-month-old mice. Likewise, half of the young stem cells were seeded on the young ECM and half were seeded on the old ECM.
Young and old cells showed a 16.1-fold and 17.1-fold expansion, respectively, when grown on ECM from young mice, compared to a 4.1-fold and 3.8-fold expansion when grown on ECM from old mice.

Finding confirmed in rodent implants
Next, under the skin of mice, Dr. Chen's group implanted artificial scaffolds seeded with stem cells of both ages that had been grown on young or old ECM. These were left to grow for eight weeks. The researchers targeted bone formation. When the implants were removed, the team found that old cells that had been grown on a young ECM produced just as much bone as young cells, while old cells grown on an old ECM produced no bone. The results were published in the FASEB Journal earlier this year.

"If this research transfers successfully to clinical application in humans, we could establish personal stem cell banks," Dr. Chen said. "We would collect a small number of older stem cells from patients, put those into our young microenvironment to rescue them — increasing their number and quality — then deliver them back into the patient."
This stem cell rescue and infusion could be done as often as disease treatment requires it, he said. The next step is to repeat the study in human stem cells and ECM.

Dr. Chen, an associate professor of comprehensive dentistry in the Health Science Center Dental School, discussed the finding at the Strategies for Engineered Negligible Senescence conference

(SENS, http://www.sens.org/conferences/sens5) held at Queens' College in Cambridge, U.K.
Source: Medical Xpress

 
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