Low levels of household income are associated with several lifetime mental disorders and suicide attempts, and a decrease in income is associated with a higher risk for anxiety, substance use, and mood disorders, according to a report in the April issue of Archives of General Psychiatry.

"To date, findings on the relationship between income and mental illness have been mixed," the authors write as background information in the article. "Some studies have found that lower income is associated with mental illness, while other studies have not found this relationship."

Jitender Sareen, M.D., FRCPC, of the University of Manitoba, Winnipeg, Canada, and colleagues analyzed data from the U.S. National Epidemiologic Survey of Alcohol and Related Conditions – the largest longitudinal, population-based mental health survey – to examine the relationship between income, mental disorders, and suicide attempts. A total of 34,653 non-institutionalized U.S. adults, age 20 years and older, were interviewed twice, three years apart.

"Participants with household income of less than $20,000 per year were at increased risk of incident mood disorders during the three-year follow-up period in comparison with those with income of $70,000 or more per year," the authors report.

"A decrease in household income during the two time points was also associated with an increased risk of incident mood, anxiety, or substance use disorders in comparison with respondents with no change in income," they write.

An increase in income during the follow-up period was not associated with any increase or decrease in the risk of developing mental disorders.

The authors believe their study findings have important public health implications.

"Most important, the findings suggest that income below $20,000 per year is associated with substantial psychopathologic characteristics and that there is a need for targeted interventions to treat and prevent mental illness in this low-income sector of the population," they conclude. "The findings also suggest that adults with reduction in income are at increased risk of mood and substance use disorders."

Source: PhysOrg

Scientists from the School of Pharmacy at Queen's University Belfast and Almac Discovery Ltd have developed a new treatment for cancer which rather than attacking tumours directly, prevents the growth of new blood vessels in tumours, starving them of oxygen and nutrients, thereby preventing their growth.

Targeting tumour blood vessels is not a new concept, however, this drug attacks the blood vessels using an entirely different pathway and therefore could be useful for treating tumours which don't respond to or which are resistant to current therapies of this type.

Professor Tracy Robson and her research team at Queen's, in collaboration with researchers at Almac Discovery, developed a new drug to disrupt the tumour blood supply. They have demonstrated that this leads to highly effective inhibition of tumour growth in a number of models as reported this month in Clinical Cancer Research, a journal of the American Association for Cancer Research. Almac Discovery is developing the drug candidate and expects to start clinical trials within the next year.

Professor Tracy Robson from the School of Pharmacy at Queen's explains: "By understanding the anti-angiogenic potential of the natural protein, FKBPL, we have been able to develop small peptide-based drugs that could be delivered to prevent tumour growth by cutting off their blood supply. This is highly effective in models of prostate and breast cancer.

"However, this also has the potential for the treatment of any solid tumour and we're excited about continuing to work with Almac Discovery as this drug enters clinical trials."

Dr Stephen Barr, President and Managing Director of Almac Discovery said: "This is a first class example of a collaboration between a university and industry to produce a novel approach to cancer therapy that has a real chance of helping patients".

The Almac Discovery / Queen's University drug is currently undergoing preclinical development and may provide a first-in-class therapy for targeting tumour angiogenesis by an entirely different pathway to those agents currently approved.

Source: EurekAlert

You might think indestructible things are a figment of the imagination of advertising. Even plastic components that have to stand up to major mechanical loads can break. The reason for this are microcracks that may be found in any component part. Researchers have now come up with elastic polymers that really heal themselves to put an end to the growth of cracks.

It can be a total surprise: car tires burst, sealing rings fail and even your dearly beloved panton chair or your freely oscillating plastic chair develops cracks and the material gets fatigued. The reason for this often sudden and unforeseen material failure is triggered by microcracks that may be found in any component. You may hardly see these cracks and they may grow fast or slow. This also applies to fractures in components made of plastic that can be elastically formed. Sealing rings or tires are made of these elastomers and they can withstand mechanical loads especially well.

In the OSIRIS project of the German Federal Ministry of Education and Research BMBF, researchers at the Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT in Oberhausen, Germany have come up with self-healing elastomers that can repair themselves autonomously, in order to put a stop to the growth of cracks already from the start while avoiding spontaneous material failure. The source of their inspiration was the caoutchouc tree hevea brasiliensis and plants that conduct latex, such as the Weeping Benjamin. This latex contains capsules that are filled with the protein hevein. If the caoutchouc tree is damaged, the latex escapes and the capsules break open to release hevein, which also links the latex particles in the latex to form a wound closure.

The scientists have applied this principle to elastomers. Dr. Anke Nellesen, who is a scientist at the Fraunhofer Institute for Environmental, Safety and Energy Technology, provides the explanation: "We loaded microcapsules with a one-component adhesive (polyisobutylene) and put it in elastomers made of synthetic caoutchouc to stimulate a self-healing process in plastics. If pressure is put on the capsules, they break open and separate this viscous material. Then this mixes with the polymer chains of the elastomers and closes the cracks. We were successful at making capsules stable to production, although they did not provide the self-healing effect we wanted." However, the researchers obtained good results by putting the self-healing component (i.e., the polyisobutylene) into the elastomer uncapsulised. Various test bodies from different synthetic caoutchoucs indicated clear self-healing properties, since the restored tension expansion was 40 percent after a healing period of 24 hours.

The experts even achieved better results by supplying elastomers with ions. Here, the caoutchouc tree also acted as the model for this method. The hevein proteins that are released when there is damage link up to each other through ions and stick in this process so that the crack closes. Therefore, if the elastomer material is damaged, the particles with opposite charges are looking for a new bonding partner – in other words, a plus ion attracts a minus ion, which makes it adhere. Anke Nellesen points out the advantage in relation to the microcapsule process: "We make sure that the wound closure is stable by charging the elastomers with ions, which means that the healing process can take place as often as needed. The scientist remarks that "there are already duromers with self-healing functions in the form of self-repairing paints in cars. We still haven't developed elastomers that can close their cracks without interference from outside."

The automobile industry could profit from this latest development, which is why you can see the prototype of self-repairing muffler suspension at the Hannover Fair in Hannover, Germany from April 4-8 at the joint Biokon stand in Hall 2.

Source: PhysOrg

Provided by Fraunhofer-Gesellschaft

Last December at the Future of Electric Vehicles conference in San Jose, a representative from The Netherlands' Eindhoven University of Technology presented research that his institution had been doing into a novel type of electromagnetic vehicle suspension. Now that a test car equipped with the suspension is about to appear at the AutoRAI exhibition in Amsterdam, the university has released some more details about the technology. For starters, it is claimed to improve the overall ride quality of cars by 60 percent.

The Eindhoven suspension is not only electromagnetic but also active, meaning that it doesn't just mechanically respond to bumps in the road, but is controlled by an onboard computer. That computer receives input from accelerometers and other sensors on the vehicle, and adjusts the suspension accordingly within a fraction of a second. While active suspension is nothing new (at least, not for cars), it has previously mainly been integrated into hydraulic systems. According to the Eindhoven researchers, however, hydraulics can't react as quickly as their electromagnetic system, and therefore can't match the smoothness of its ride.

As with existing active suspension systems, this one should also make driving safer, as it would reportedly keep cars from swaying into corners.

About the same size as a conventional shock absorber, the system consists of a passive spring, an electromagnetic actuator, a control unit and batteries. The spring – appropriately enough – provides springing action, while the magnets provide passive shock absorption. If the batteries should fail, the system will still work as a purely mechanical suspension.

With a peak consumption of 500 watts, the suspension uses about a quarter of the power of hydraulic systems. It also stretches its battery life by using road vibrations to generate electricity. The designers believe that with refinements, the suspension's energy-efficiency could be improved even further.

The 60 percent ride improvement figure was obtained when a single wheel equipped with the system was mounted on a laboratory testbed that simulates road conditions. Last month, a test car had the system installed on two of its wheels, for actual on-road testing. At the moment, each wheel equipped with the suspension acts independently, so the researchers are now developing systems for allowing the individual suspension units to communicate with one another and coordinate their actions.

Source: GizMag

Some people collect stamps and coins, but when it comes to sheer utility, few collections rival the usefulness of Rice University researcher Michael Deem's collection of 2.6 million zeolite structures.

Zeolites are materials -- including some natural minerals -- that act as molecular sieves, thanks to a Swiss-cheese-like arrangement of pores that can sort, filter, trap and chemically process everything from drugs and petroleum to nuclear waste. Zeolites are particularly useful as catalysts -- materials that spur chemical reactions. There are about 50 naturally occurring zeolites and almost three times as many man-made varieties.

Deem's database, which is described in a new paper that will be featured on the cover of an upcoming issue of the Royal Society of Chemistry's journal Physical Chemistry Chemical Physics, hints at the untapped possibilities for making even more synthetic zeolites.

"For many catalytic applications only a single material has been found," said Deem, the John W. Cox Professor in Biochemical and Genetic Engineering and professor of physics and astronomy. "Expanding the diversity of the zeolite structures would be helpful to improve performance in existing applications, to explore novel functions and to answer basic scientific questions."

Zeolites are useful because of the particular way atoms are mixed and arranged in their porous interiors. Based on these arrangements, zeolites can cause chemicals to react in particular ways, and even subtle changes in the arrangements can alter the reactions that are spurred. Deem's database was created to explore the many zeolite structures that are physically possible, and he said several researchers are already using the information to identify zeolites that could be used for carbon sequestration and other applications.

"Computational methods can play a stimulatory role in the synthesis of new zeolite materials," Deem said. "That is the motivation; that is the challenge that brings us back to zeolites time and again."

In 2007, Deem and his students used both supercomputers and unused computing cycles from more than 4,300 idling desktop PCs to painstakingly calculate every conceivable atomic formulation for zeolites. They created a database of more than 3.4 million atomic formulations of the porous silicate minerals.

In the current study, Deem, Rice graduate student Ramdas Pophale and Purdue University computational analyst Phillip Cheeseman designed tools to examine and compare the physical properties of each entry. Using these tools, they pared down the larger set by removing potential redundancies as well as "low-energy" structures that would either be unstable or impossible to synthesize.

For each of the 2.6 million remaining structures in the database, the team carried out calculations to find specific physical and chemical properties -- including X-ray diffraction patterns, ring-size distributions and dielectric constants -- that could help guide researchers interested in synthesizing them or in finding a new type of zeolite for a specific application.

Deem said the new database has been deposited in the publicly available Predicted Crystallography Open Database.

Source: physorg

Provided by Rice University

Tekniker-IK4 is taking part in a European project investigating new materials based on carbonaceous nanoparticles for application to sectors such as automobiles and construction.

A brake pedal able to detect the pressure of the driver's foot, a paint for vehicles resistant to scratching and with self-repairing capacity, self-lubricating engine components, a low-cost and fire-resistant construction panel or a thermal insulating foam with enhanced efficiency.

These are just some of the applications that can be generated by using new, value-added materials based on carbonaceous nanoparticles, and on the research of which Tekniker-IK4 technological centre is working within the remit of the European CarbonInspired Project.

The development of new materials with enhanced properties is a consequence of the fact that nanometric-sized materials present excellent and unique properties (mechanical, electrical, magnetic, optical, etc.), which enable their application to multiple sectors.

The project initiated its work this year by bringing together the skills of different bodies grouped into a consortium, and amongst which are, apart from the Basque centre, the Centre for Automotive Technology of Galicia (CTAG), the Association for Research into Plastics Materials (AIMPLAS), the Universidade de Aveiro (Portugal) and the Institut Polytechnique de Bordeaux (France).

One of the goals of the project, besides boosting research in a field that has multiple applications, is the creation of a network of transference between Spain, Portugal and the south of France for the application of these materials based on carbonaceous nanoparticles within the automotive and construction sectors.

The network of collaboration between public and private R+D+i centres created by CarbonInspired will act to transfer knowledge to the companies and will provide advice to companies in the southwest of Europe, especially to small and medium-sized companies, regarding the development of new carbonaceous nanoparticle-based products and processes.

Source: EurekAlert

Quantum physicists from the University of Innsbruck (Austria) have set another world record: They have achieved controlled entanglement of 14 quantum bits (qubits) and, thus, realized the largest quantum register that has ever been produced. With this experiment the scientists have not only come closer to the realization of a quantum computer but they also show surprising results for the quantum mechanical phenomenon of entanglement.

The term entanglement was introduced by the Austrian Nobel laureate Erwin Schrödinger in 1935, and it describes a quantum mechanical phenomenon that while it can clearly be demonstrated experimentally, is not understood completely. Entangled particles cannot be defined as single particles with defined states but rather as a whole system. By entangling single quantum bits, a quantum computer will solve problems considerably faster than conventional computers. "It becomes even more difficult to understand entanglement when there are more than two particles involved," says Thomas Monz, junior scientist in the research group led by Rainer Blatt at the Institute for Experimental Physics at the University of Innsbruck. "And now our experiment with many particles provides us with new insights into this phenomenon," adds Blatt.

World record: 14 quantum bits

Since 2005 the research team of Rainer Blatt has held the record for the number of entangled quantum bits realized experimentally. To date, nobody else has been able to achieve controlled entanglement of eight particles, which represents one quantum byte. Now the Innsbruck scientists have almost doubled this record. They confined 14 calcium atoms in an ion trap, which, similar to a quantum computer, they then manipulated with laser light. The internal states of each atom formed single qubits and a quantum register of 14 qubits was produced. This register represents the core of a future quantum computer. In addition, the physicists of the University of Innsbruck have found out that the decay rate of the atoms is not linear, as usually expected, but is proportional to the square of the number of the qubits. When several particles are entangled, the sensitivity of the system increases significantly. "This process is known as superdecoherence and has rarely been observed in quantum processing," explains Thomas Monz. It is not only of importance for building quantum computers but also for the construction of precise atomic clocks or carrying out quantum simulations.

Increasing the number of entangled particles

By now the Innsbruck experimental physicists have succeeded in confining up to 64 particles in an ion trap. "We are not able to entangle this high number of ions yet," says Thomas Monz. “However, our current findings provide us with a better understanding about the behavior of many entangled particles." And this knowledge may soon enable them to entangle even more atoms.

Some weeks ago Rainer Blatt’s research group reported on another important finding in this context in the scientific journal Nature: They showed that ions might be entangled by electromagnetic coupling. This enables the scientists to link many little quantum registers efficiently on a micro chip. "All these findings are important steps to make quantum technologies suitable for practical information processing," Rainer Blatt is convinced.

The results of this work are published in the scientific journal Physical Review Letters.

More information: 14-Qubit Entanglement: Creation and Coherence. Thomas Monz, Philipp Schindler, Julio T. Barreiro, Michael Chwalla, Daniel Nigg, William A. Coish, Maximilian Harlander, Wolfgang Hänsel, Markus Hennrich, Rainer Blatt. Phys. Rev. Lett. 106, 130506 (2011) DOI:10.1103/PhysRevLett.106.130506

Source: physorg

Provided by University of Innsbruck

Researchers at the University of Warwick have developed a gold plated window as the transparent electrode for organic solar cells. Contrary to what one might expect, these electrodes have the potential to be relatively cheap since the thickness of gold used is only 8 billionths of a metre.

This ultra-low thickness means that even at the current high gold price the cost of the gold needed to fabricate one square metre of this electrode is only around £4.5. It can also be readily recouped from the organic solar cell at the end of its life and since gold is already widely used to form reliable interconnects it is no stranger to the electronics industry.

Organic solar cells have long relied on Indium Tin Oxide (ITO) coated glass as the transparent electrode, although this is largely due to the absence of a suitable alternative. ITO is a complex, unstable material with a high surface roughness and tendency to crack upon bending if supported on a plastic substrate. If that wasn't bad enough one of its key components, indium, is in short supply making it relatively expensive to use.

An ultra-thin film of air-stable metal like gold would offer a viable alternative to ITO, but until now it has not proved possible to deposit a film thin enough to be transparent without being too fragile and electrically resistive to be useful.

Now research led by Dr Ross Hatton and Professor Tim Jones in the University of Warwick 's department of Chemistry has developed a rapid method for the preparation of robust, ultra-thin gold films on glass. Importantly this method can be scaled up for large area applications like solar cells and the resulting electrodes are chemically very well-defined.

Dr Hatton says "This new method of creating gold based transparent electrodes is potentially widely applicable for a variety of large area applications, particularly where stable, chemically well-defined, ultra-smooth platform electrodes are required, such as in organic optoelectronics and the emerging fields of nanoelectronics and nanophotonics."

The paper documents the team's success in creating this simple, practical and effective method of depositing the films onto glass, and also reports how the optical properties can be fine tuned by perforating the film with tiny circular holes using something as simple as polystyrene balls. The University of Warwick research team has also had some early success in depositing ultra-thin gold films directly on plastic substrates, an important step towards realising the holy grail of truly flexible solar cells. This innovation is set to be exploited by Molecular Solar Ltd, a Warwick spinout company dedicated to commercialising the discoveries of its academic founders in the area of organic solar cells.

Source: ScienceDaily

A Stanford research team uses glowing nanopillars to give biologists, neurologists and other researchers a deeper, more precise look into living cells.

As words go, evanescent doesn't see enough use. It is an artful term whose beauty belies its true meaning: fleeting or dying out quickly. James Dean was evanescent. The last rays of a sunset are evanescent. All that evanesces, however, is not lost, as a team of Stanford researchers demonstrated in a recent article in Proceedings of the National Academy of Sciences. In fact, in the right hands, evanescence can have a lasting effect.

The Stanford team – led by chemist Bianxiao Cui and engineer Yi Cui (no relation), with scholars Chong Xie and Lindsey Hanson – have created a cellular research platform that uses nanopillars that glow in such a way as to allow biologists, neurologists and other researchers a deeper, more precise look into living cells.

"This novel system of illumination is very precise," said Bianxiao Cui, the study's senior author and assistant professor of chemistry at Stanford. "The nanopillar structures themselves offer many advantages that make this development particularly promising for the study of human cells."

Longstanding challenges

To comprehend the potential of this breakthrough, it is helpful to understand the challenges to earlier forms of molecular imaging, which shine light directly on the subject area rather than using backlighting, as in this approach.

Scientists hoping for better, smaller molecular imaging have for years been handcuffed by a physical limitation on how small an area they could focus on – an area known as the observation volume. The minimum observation volume has long been limited to the wavelength of visible light, about 400 nanometers. Individual molecules, even long proteins common in biology and medicine, are much smaller than 400 nanometers.

This is where evanescence comes in. The Stanford team has successfully employed quartz nanopillars that glow just enough to provide light to see by, but weak enough to punch below the 400-nanometer barrier. The field of light surrounding the glowing nanopillars – known as the "evanescence wave" – dies out within about 150 nanometers of the pillar. Voilà – a light source smaller than the wavelength of light. The Stanford researchers estimate that they have shrunk the observation volume to one-tenth the size of previous methods.
Particular promise

The Stanford nanopillar imaging technique is particularly promising in cellular studies for several reasons. First, it is non-invasive – it does not harm the cell that is being observed, a downfall of some earlier technologies. For instance, a living neuron can be cultured on the platform and observed over long periods of time.

Second, the nanopillars essentially pin the cells in place. This is promising for the study of neurons in particular, which tend to move over time due to the repeated firing and relaxation necessary for study.

Lastly, and perhaps most importantly, the Stanford team found that by modifying the chemistry on the surface of the nanopillars they could attract specific molecules they want to observe. In essence they can handpick molecules to study even within the crowded and complex environment of a human cell.

"We know that proteins and their antibodies attract each other," said Bianxiao Cui. "We coat the pillars with antibodies and the proteins we want to look at are drawn right to the light source – like prima donnas to the limelight."

Setting the scene

To create their nanopillars, the Stanford team members begin with a sheet of quartz, which they spray with fine dots of gold in a scattershot pattern – Jackson Pollock-style. They then etch the quartz using a corrosive gas. The gold dots shield the quartz directly below from the etching process, leaving behind tall, thin pillars of quartz.

A scanning electron microscope image of a cell grown over and interacting with nanopillars. Arrows indicate three nanopillars.

The researchers can control the height of the nanopillars by adjusting the amount of time the etching gas is in contact with the quartz and the diameter of the nanopillars by varying the size of the gold dots. Once the etching process is complete and the pillars are created, they add a layer of platinum to the flat expanse of quartz at the base of the pillars.
The setting is something out of a futuristic John Ford film – Monument Valley rendered in quartz crystal. All that is missing is a stagecoach and John Wayne. In this world, a wide desert of platinum stretches to the horizon, interrupted on occasion by transparent spikes of crystalline quartz that rise several hundred nanometers from the valley floor.

The Stanford researchers then shine a light from below their creation. The opaque platinum blocks most of the light, but a small amount travels up through the nanopillars, which glow against the dark field of platinum.

"The nanopillars look a bit like tiny light sabers," said Yi Cui, associate professor of materials science and engineering at Stanford, "but they provide just the right amount of light to allow scientists to do some pretty amazing stuff – like looking at individual molecules."

The team has created an exceptional platform for culturing and observing human cells. The platinum is biologically inert and the cells grow over and closely adhere to the nanopillars. The glowing spires then meet with fluorescent molecules within the living cell, causing the molecules to glow – providing the researchers just the light they need to peer inside the cells.

"So, not only have we found a way to illuminate volumes one-tenth as small as previous methods – letting us look at smaller and smaller structures – but we can also pick and choose which molecules we want to observe," said Yi Cui. "This could prove just the sort of transformative technology that researchers in biology, neurology, medicine and other areas need to take the next leap forward in their research."

Source: PhysOrg

In an interesting feat of nanoscale engineering, researchers at Lund University in Sweden and the University of New South Wales have made the first nanowire transistor featuring a concentric metal 'wrap-gate' that sits horizontally on a silicon substrate.

Two remarkable aspects of their design are the simplicity of the fabrication and the unique ability to tune the length of the wrap-gate via a single wet-etch step, notes Associate Professor Adam Micolich, an ARC Future Fellow in the Nanoelectronics Group in the UNSW School of Physics.

Packing ever higher densities of transistors into a microchip comes at a hefty price – the reduced overlap between the semiconductor channel through which the current flows and the metal gate makes it harder to switch the current on and off.

This drove the development of the ‘Fin Field-Effect Transistor’, or FinFET, where the silicon either side of the channel is etched away to create a raised mesa structure. This allows the gate to fold down around the sides of the channel, improving the switching without increasing the chip space needed by the device. Even better control can be obtained by wrapping the gate all the way around the channel. But getting metal underneath the channel without compromising the device can be a formidable task using conventional ‘top-down’ silicon microfabrication techniques.

This has led to significant interest in self-assembled nanowires for computing applications (see D.K. Ferry, doi: 10.1126/science.1154446). These tiny semiconductor needles, around 50 nm in diameter and up to several microns in length, are grown using chemical vapour deposition and stand vertically on a semiconductor substrate, making it possible to deposit an insulator and gate metal around the nanowire’s entire outer surface.

Although these coated nanowires can be made into fully-functioning transistors in the vertical orientation, the process to achieve this is very involved. And in many cases, it is more desirable to have the nanowire transistor lying flat on the substrate, as with conventional silicon transistors. This poses an interesting challenge for nanotechnologists: Is it possible to make nanowire transistors with an all-around metal ‘wrap-gate’ that lay flat on a semiconductor substrate?

In work published this week in Nano Letters [Storm et al. doi:10.1021/nl104403g], the team not only demonstrate the first such horizontal wrap-gate nanowire transistors, but they demonstrate that they can be made using a remarkably simple process that allows them to precisely set the wrap-gate’s length using a single wet-etch step, without any need for further lithography.

Their approach exploits the etchant solution’s ability to undercut the resist and etch along the nanowire, producing gates that range in length from slightly less than the contact separation to as low as 100 nm, simply by tuning the etchant concentration. The resulting devices have excellent electrical performance and can be produced reliably with high yield.

Beyond being a significant advance in nanofabrication techniques, these devices open interesting new avenues for fundamental research.

The wrap-gated nanowires are ideal for studies of one-dimensional quantum transport in semiconductors, where remarkable phenomena such as electron crystallization and spin-charge separation may be observed. Additionally, the strong gate-channel coupling combined with an exposed gold wrap-gate surface offers interesting potential for sensing applications by utilising the established chemistry for binding antibodies and other polypeptides to gold surfaces.

Source: PhysOrg