Zürich, Switzerland
Zürich, Switzerland

Time filter

Source Type

News Article | February 28, 2017
Site: www.cemag.us

It’s not enough to design new drugs. For drugs to be effective, they have to be delivered safely and intact to affected areas of the body. And drug delivery, much like drug design, is an immensely complex task. Cutting-edge research and development like that conducted at the U.S. Department of Energy’s Oak Ridge National Laboratory can help solve some of the challenges associated with drug delivery. In fact, ORNL researchers and collaborators at Wayne State University recently used a unique combination of experimentation and simulation to shed light on the design principles for improved delivery of RNA drugs, which are promising candidates in the treatment of a number of medical conditions including cancers and genetic disorders. Specifically, the research team discovered that the motions of a tRNA (or transfer RNA) model system can be enhanced when coupled with nanodiamonds, or diamond nanoparticles approximately 5 to 10 nanometers in size. Nanodiamonds are good delivery candidates due to their spherical shape, biocompatibility and low toxicity. And because their surfaces can be easily tailored to facilitate the attachment of various medicinal molecules, nanodiamonds have tremendous potential for the delivery of a vast range of therapies. The discovery involved ORNL’s Spallation Neutron Source, which provides the most intense pulsed neutron beams in the world for scientific research and industrial development, and ORNL’s Titan supercomputer, the nation’s most powerful for open science -- a one-two punch for illuminating the physical properties of potential drugs that inform new design principles for safer, improved delivery platforms. By comparing the SNS neutron scattering data with the data from the team’s molecular dynamics simulations on Titan, the researchers have confirmed that nanodiamonds enhance the dynamics of tRNA when in the presence of water. This cross-disciplinary research was profiled in Journal of Physical Chemistry B. The project began when ORNL’s P. Ganesh and Xiang-Qiang Chu of Wayne State University wondered how the water-phobic surfaces of nanoparticles alter the dynamics of biomolecules coated with water, and if it might be something that they could eventually control. They then formed a team including Gurpreet Dhindsa, Hugh O’Neill, Debsindhu Bhowmik, and Eugene Mamontov of ORNL and Liang Hong of Shanghai Jiao Tong University in China to observe the motions of hydrogen atoms from the model system, tRNA, in water using SNS’s BASIS neutron backscattering spectrometer, SNS beam line 2. Hydration is essential for biomolecules to function, and neutrons are excellent at distinguishing between the motions of hydration water molecules and the biomolecule they are surrounding. Therefore, by measuring the atoms’ neutron scattering signals, the team was able to discern the movement of tRNA in water, providing valuable insight into how the large molecule relaxes in different environmental conditions. After comparing the results of the individual atoms, it was clear that the nanodiamonds were having a profound effect on their companion RNA molecules. The results were somewhat baffling because similar experiments had demonstrated that companion solid materials (such as nanodiamonds) tended to dampen biomolecule dynamics. Surprisingly however, nanodiamonds did the opposite for tRNA. “Scientists are always interested in the bio-nano interactions,” says Chu. “While the interfacial layer of the bio-nano systems has very distinctive properties, it is very hard to study this mysterious zone without neutron scattering, which only sees hydrogen.” To realize the potential of nanodiamonds in the delivery of biomolecules using tRNA as a model, the team turned to Titan to shed a much-needed light on the underlying physics. “Molecular dynamics simulation can really tell those stories that current experimental advancement might not be able to,” says Bhowmik of ORNL’s Computational Science and Engineering Division, who set up and conducted the simulations alongside Monojoy Goswami of the laboratory’s Computer Science and Mathematics Division and Hong of Shanghai Jiao Tong University. “By combining these two techniques, you can enter a whole new world.” These simulations revealed that the “weak dynamic heterogeneity” of RNA molecules in the presence of nanodiamonds was responsible for the enhanced effect. In other words, the reactions among the nanodiamonds, water and the RNA molecule forms a water layer on the nanodiamond surface, which then blocks it and prevents strong RNA contact to the nanodiamond. Since RNA is hydrophilic, or “likes water,” the molecules on the nanodiamond surface swell with excess hydration and weaken the heterogeneous dynamics of the molecules. “You can fine-tune these dynamics with chemical functionalization on the nanodiamond surface, further enhancing its effectiveness,” says Goswami. The findings will likely guide future studies not only on the potential of nanodiamonds in drug delivery but also on fighting bacteria and treating viral diseases. Using simulation to confirm and gain insight into experiments is nothing new. But mimicking large-scale systems precisely is often a challenge, and the lack of quantitative consistency between the two disciplines makes data comparison difficult and answers more elusive to researchers. This lack of precision, and by extension lack of consistency, is largely driven by the uncertainty surrounding force-field parameters or the interaction criteria between different particles. The exact parameters are scarce for many macromolecules, often forcing researchers to use parameters that closely, but not exactly, match the experiment. Miscalculating the precision of these parameters can have major consequences for the interpretation of the experimental results. To ensure the calculations were correct, Goswami worked with Jose Borreguero and Vickie Lynch, both of ORNL’s Neutron Data Analysis and Visualization Division and Center for Accelerated Materials Modeling, to develop a workflow optimization technique known as Pegasus. This method compares molecular dynamics simulations with neutron scattering data and refines the simulation parameters to validate the results with the proper experimental precision. “Using the Pegasus workflow to run simulations sampling, the force-field parameter space saved time and eliminated input errors,” says Lynch. These parameters also helped researchers better characterize the nanodiamond-water interactions and tRNA dynamics in the presence of nanodiamonds. The researchers then developed an automated system capable of optimizing parameters across a wide spectrum of simulation systems and neutron experiments, an effort that will be of great worth to similar experiments going forward. This new workflow is also compatible with the laboratory’s Compute and Data Environment for Science (CADES), which assists experimentalists with the analysis of vast quantities of data. “Users of the CADES infrastructure can carry the optimization of the simulations within the Bellerophon Environment for the Analysis of Materials, in active development at ORNL,” says Borreguero. The Bellerophon Environment for the Analysis of Materials (BEAM) is an end-to-end workflow software system, developed at ORNL, enabling user-friendly, remote access to robust data storage and compute capabilities offered at CADES and the Oak Ridge Leadership Computing Facility, home of Titan, for scalable data analysis and modeling. It’s these in-house resources that make ORNL a world leader in experimentation, modeling, and the nexus in between and that make discoveries like this possible.


In fact, ORNL researchers and collaborators at Wayne State University recently used a unique combination of experimentation and simulation to shed light on the design principles for improved delivery of RNA drugs, which are promising candidates in the treatment of a number of medical conditions including cancers and genetic disorders. Specifically, the research team discovered that the motions of a tRNA (or transfer RNA) model system can be enhanced when coupled with nanodiamonds, or diamond nanoparticles approximately 5 to 10 nanometers in size. Nanodiamonds are good delivery candidates due to their spherical shape, biocompatibility and low toxicity. And because their surfaces can be easily tailored to facilitate the attachment of various medicinal molecules, nanodiamonds have tremendous potential for the delivery of a vast range of therapies. The discovery involved ORNL's Spallation Neutron Source, which provides the most intense pulsed neutron beams in the world for scientific research and industrial development, and ORNL's Titan supercomputer, the nation's most powerful for open science—a one-two punch for illuminating the physical properties of potential drugs that inform new design principles for safer, improved delivery platforms. By comparing the SNS neutron scattering data with the data from the team's molecular dynamics simulations on Titan, the researchers have confirmed that nanodiamonds enhance the dynamics of tRNA when in the presence of water. This cross-disciplinary research was profiled in Journal of Physical Chemistry B. The best of both worlds The project began when ORNL's P. Ganesh and Xiang-Qiang Chu of Wayne State University wondered how the water-phobic surfaces of nanoparticles alter the dynamics of biomolecules coated with water, and if it might be something that they could eventually control. They then formed a team including Gurpreet Dhindsa, Hugh O'Neill, Debsindhu Bhowmik and Eugene Mamontov of ORNL and Liang Hong of Shanghai Jiao Tong University in China to observe the motions of hydrogen atoms from the model system, tRNA, in water using SNS's BASIS neutron backscattering spectrometer, SNS beam line 2. Hydration is essential for biomolecules to function, and neutrons are excellent at distinguishing between the motions of hydration water molecules and the biomolecule they are surrounding. Therefore, by measuring the atoms' neutron scattering signals, the team was able to discern the movement of tRNA in water, providing valuable insight into how the large molecule relaxes in different environmental conditions. After comparing the results of the individual atoms, it was clear that the nanodiamonds were having a profound effect on their companion RNA molecules. The results were somewhat baffling because similar experiments had demonstrated that companion solid materials (such as nanodiamonds) tended to dampen biomolecule dynamics. Surprisingly however, nanodiamonds did the opposite for tRNA. "Scientists are always interested in the bio-nano interactions," said Chu. "While the interfacial layer of the bio-nano systems has very distinctive properties, it is very hard to study this mysterious zone without neutron scattering, which only sees hydrogen." To realize the potential of nanodiamonds in the delivery of biomolecules using tRNA as a model, the team turned to Titan to shed a much-needed light on the underlying physics. "Molecular dynamics simulation can really tell those stories that current experimental advancement might not be able to," said Bhowmik of ORNL's Computational Science and Engineering Division, who set up and conducted the simulations alongside Monojoy Goswami of the laboratory's Computer Science and Mathematics Division and Hong of Shanghai Jiao Tong University. "By combining these two techniques, you can enter a whole new world." These simulations revealed that the "weak dynamic heterogeneity" of RNA molecules in the presence of nanodiamonds was responsible for the enhanced effect. In other words, the reactions among the nanodiamonds, water and the RNA molecule forms a water layer on the nanodiamond surface, which then blocks it and prevents strong RNA contact to the nanodiamond. Since RNA is hydrophilic, or "likes water," the molecules on the nanodiamond surface swell with excess hydration and weaken the heterogeneous dynamics of the molecules. "You can fine-tune these dynamics with chemical functionalization on the nanodiamond surface, further enhancing its effectiveness," said Goswami. The findings will likely guide future studies not only on the potential of nanodiamonds in drug delivery but also on fighting bacteria and treating viral diseases. Using simulation to confirm and gain insight into experiments is nothing new. But mimicking large-scale systems precisely is often a challenge, and the lack of quantitative consistency between the two disciplines makes data comparison difficult and answers more elusive to researchers. This lack of precision, and by extension lack of consistency, is largely driven by the uncertainty surrounding force-field parameters or the interaction criteria between different particles. The exact parameters are scarce for many macromolecules, often forcing researchers to use parameters that closely, but not exactly, match the experiment. Miscalculating the precision of these parameters can have major consequences for the interpretation of the experimental results. To ensure the calculations were correct, Goswami worked with Jose Borreguero and Vickie Lynch, both of ORNL's Neutron Data Analysis and Visualization Division and Center for Accelerated Materials Modeling, to develop a workflow optimization technique known as Pegasus. This method compares molecular dynamics simulations with neutron scattering data and refines the simulation parameters to validate the results with the proper experimental precision. "Using the Pegasus workflow to run simulations sampling, the force-field parameter space saved time and eliminated input errors," said Lynch. These parameters also helped researchers better characterize the nanodiamond-water interactions and tRNA dynamics in the presence of nanodiamonds. The researchers then developed an automated system capable of optimizing parameters across a wide spectrum of simulation systems and neutron experiments, an effort that will be of great worth to similar experiments going forward. This new workflow is also compatible with the laboratory's Compute and Data Environment for Science (CADES), which assists experimentalists with the analysis of vast quantities of data. "Users of the CADES infrastructure can carry the optimization of the simulations within the Bellerophon Environment for the Analysis of Materials, in active development at ORNL," said Borreguero. The Bellerophon Environment for the Analysis of Materials (BEAM) is an end-to-end workflow software system, developed at ORNL, enabling user-friendly, remote access to robust data storage and compute capabilities offered at CADES and the Oak Ridge Leadership Computing Facility, home of Titan, for scalable data analysis and modeling. It's these in-house resources that make ORNL a world leader in experimentation, modeling and the nexus in between and that make discoveries like this possible. Explore further: High-performance simulation, neutrons uncover three classes of protein motion More information: Gurpreet K. Dhindsa et al. Enhanced Dynamics of Hydrated tRNA on Nanodiamond Surfaces: A Combined Neutron Scattering and MD Simulation Study, The Journal of Physical Chemistry B (2016). DOI: 10.1021/acs.jpcb.6b07511


News Article | February 15, 2017
Site: www.eurekalert.org

Using theoretical methods, an international group of scientists led by Artem R. Oganov, Professor of Skoltech, Stony Brook University and Moscow Institute of Physics and Technology predicted unusual from the point of view of classical chemistry nitrides of hafnium and chromium with the chemical formulae HfN10 (and its zirconium analogue ZrN10) and CrN4. These compounds can be obtained at relatively low pressures and contain high-energy groups of nitrogen atoms. Pure polymeric nitrogen is the ideal high-energy compound that packs so much energy per unit volume or mass that it could be used as a powerful explosive if it were not for gigantic pressures of its synthesis. This work shows that nitrogen polymerizes at much lower pressures in presence of metal ions, and such compounds might find practical use. The authors also predicted a range of new hafnium nitrides as well as nitrides, carbides and borides of chromium, with an unusual combination of properties (high hardness, electrical conductivity, and toughness). Superhard materials can be divided into two main classes: compounds of boron, carbon, nitrogen and oxygen together and compounds of transition metals with boron, carbon and nitrogen. The scientists studied four systems in two simultaneously published works: hafnium-nitrogen, chromium-nitrogen, chromium-carbon and chromium-boron. Several new materials, which can be formed at relatively low pressure, were predicted. Among them there are materials with an unusual combination of very high hardness and electrical conductivity. In particular, newly predicted carbide Cr2C should even be stable at atmospheric pressure; and researchers were able to resolve for the first time the crystal structure of a known compound Cr2N. The most interesting finding is the chemical compound with the formula HfN10 - here, there are ten nitrogen atoms per hafnium atom. Its structure is very peculiar from a chemical point of view: The hafnium atoms and N2 molecules are sandwiched between infinite chains of nitrogen atoms. Such structure is formed under relatively low pressure of 0.23 Mbar. According to Professor Artem R. Oganov: "This finding brings us back to one of the Holy Grails in material science, the search for polymeric nitrogen, an ideal high-energy-density material". The fact of the matter is that all good explosive compounds contain nitrogen - at the moment of explosion the nitrogen atoms form the extraordinary stable N2 molecule, releasing a vast amount of energy. The more nitrogen atoms in a compound, and the more unusual their bonding, the more energy will be released as a result of the explosion. Polymeric nitrogen was first predicted by American physicist C. Mailhiot in 1992 and then synthesized in 2004 by Russian physicist Michael Eremets under pressures exceeding one million atmospheres. At such pressures only micron-sized samples can be made, which rules out any practical applications. Professor Oganov says: "Our group works on several projects related to metal polynitrides. This is a promising class of high-energy-density compounds, requiring much lower pressures than pure polymeric nitrogen (e.g., 5 times lower in case of HfN10, or even less for CrN4, and this is likely not the limit). Chemists have long dreamed about synthesising polymeric nitrogen in large quantities. We have proposed the compound class that can fulfil this dream. " Two publications appeared as a result of these studies. The first author of the article published in The Journal of Physical Chemistry Letters is Alexander Kvashnin, a postdoc at Skoltech. The first author of the second article in Physical Review B is Jin Zhang, Oganov's graduate student at Stony Brook University. The Skolkovo Institute of Science and Technology (Skoltech) is a private graduate research university. Established in 2011 in collaboration with the Massachusetts Institute of Technology (MIT), Skoltech educates global leaders in innovation, advance scientific knowledge, and fosters new technologies to address critical issues facing Russia and the world. Skoltech conducts it work integrating the best practices of the best Russian and international educational and scientific research universities. Moreover, the university pays particular attention to entrepreneurship and innovative education. Website: http://www.


News Article | February 15, 2017
Site: www.eurekalert.org

Erlantz Lizundia, a researcher in the UPV/EHU's department of Physical Chemistry and expert in cellulose, started the research during a period of time he spent in Canada. The research group he was in specialised in the helix-shaped organisation of a product extracted from cellulose, cellulose nanocrystals (CNCs). Under specific conditions, the crystals can assume a helical structure, or what is the same, they can form chiral nematic structures when the crystals are organised into ordered layers, and membranes with unique properties can thus be obtained: "The membrane displays a different colour depending on the distance existing between the layers of cellulose nanocrystals that form the helical, or chiral nematic structure. An interaction takes place between the structure and the light and, as a result, the wavelength of the light changes and materials in bright colours are obtained," explained Lizundia. This capacity to change colour displayed by the structure "could prove very useful in enabling these membranes to be used as sensors; for example, when they are put into a humid environment, the structure will swell and the distance between the layers will increase and the colour will change," he added. This effect is known as structural coloration and is very common in nature. The colour of a whole host of animals (snakes, chameleons) and plants is the direct consequence of their supramolecular structure, and contrary to what one may think, is not linked to the presence of pigments. Suitable as metal sensors and for bioimaging purposes Inserting carbon dots into the chiral nematic structure of the cellulose nanocrystals makes this material particularly suited as a detector for the presence of iron so, as Lizundia explains, "it is very useful for detecting environmental pollution or the presence of metals in the body. I, specifically, studied the material's response to zinc and iron, as they are both present in large quantities in environmental and biological matters. I was able to see that the interaction of the metal ions with the carbon nanoparticles influences the degree of fluorescence emitted by the nanoparticles. The fluorescence diminishes in the presence of iron, whereas it increases in the presence of zinc". Another possible application of this material could be in bioimaging. In the research conducted, Lizundia only managed to get as far as testing that it does in fact offer this possibility. "I will shortly be embarking on research to go further into this subject and use these nanoparticles to create bioimages". Bioimaging consists of creating images using non-invasive methods in biological processes, such as cell processes, as well as measuring the interaction between molecules in real time in the location where these interactions are taking place. The UPV/EHU researcher Erlantz Lizundia conducted his research work in collaboration with the University of British Columbia (UBC) in Canada, and with the FPInnovations organisation, also Canadian. At that time, Lizundia was a researcher in the department of Physical Chemistry on the UPV/EHU's Leioa campus. Right now, however, he is assistant lecturer in the Department of Graphic Expression and Engineering Projects in the Faculty of Engineering in Bilbao. Wanting to go a step beyond what he had learned in Canada, Lizundia considered incorporating other functional nanoparticles into this chiral nematic structure, particles whose properties change in the presence of external stimuli. He chose some carbon nanodots, firstly because they are fluorescent, in other words, they emit colour when excited by ultraviolet light, and secondly, because he was able to obtain them by using sugar as the raw material. "I obtained these nanoparticles by subjecting glucose to hydrothermal treatment using water and heat only and by means of a fast, cheap process," the researcher pointed out. The final material displayed the characteristics Lizundia had been seeking. Firstly, "it is an environmentally friendly material as it is non-toxic and its raw materials are of a renewable nature, and the synthesis process is fast, simple and scalable. Secondly, the fact that the material is fluorescent gives it interesting properties enabling it to be used as a sensor," specified Lizundia.


News Article | February 16, 2017
Site: www.chromatographytechniques.com

Wearable electronics are here — the most prominent versions are sold in the form of watches or sports bands. But soon, more comfortable products could become available in softer materials made in part with an unexpected ingredient: green tea. Researchers report in ACS’ The Journal of Physical Chemistry C a new flexible and compact rechargeable energy storage device for wearable electronics that is infused with green tea polyphenols. Powering soft wearable electronics with a long-lasting source of energy remains a big challenge. Supercapacitors could potentially fill this role — they meet the power requirements, and can rapidly charge and discharge many times. But most supercapacitors are rigid, and the compressible supercapacitors developed so far have run into roadblocks. They have been made with carbon-coated polymer sponges, but the coating material tends to bunch up and compromise performance. Guruswamy Kumaraswamy, Kothandam Krishnamoorthy and colleagues wanted to take a different approach. The researchers prepared polymer gels in green tea extract, which infuses the gel with polyphenols. The polyphenols converted a silver nitrate solution into a uniform coating of silver nanoparticles. Thin layers of conducting gold and poly(3,4-ethylenedioxythiophene) were then applied. And the resulting supercapacitor demonstrated power and energy densities of 2,715 watts per kilogram and 22 watt-hours per kilogram — enough to operate a heart rate monitor, LEDs or a Bluetooth module. The researchers tested the device’s durability and found that it performed well even after being compressed more than 100 times.


News Article | February 16, 2017
Site: www.sciencedaily.com

Wearable electronics are here -- the most prominent versions are sold in the form of watches or sports bands. But soon, more comfortable products could become available in softer materials made in part with an unexpected ingredient: green tea. Researchers report in ACS' The Journal of Physical Chemistry C a new flexible and compact rechargeable energy storage device for wearable electronics that is infused with green tea polyphenols. Powering soft wearable electronics with a long-lasting source of energy remains a big challenge. Supercapacitors could potentially fill this role -- they meet the power requirements, and can rapidly charge and discharge many times. But most supercapacitors are rigid, and the compressible supercapacitors developed so far have run into roadblocks. They have been made with carbon-coated polymer sponges, but the coating material tends to bunch up and compromise performance. Guruswamy Kumaraswamy, Kothandam Krishnamoorthy and colleagues wanted to take a different approach. The researchers prepared polymer gels in green tea extract, which infuses the gel with polyphenols. The polyphenols converted a silver nitrate solution into a uniform coating of silver nanoparticles. Thin layers of conducting gold and poly(3,4-ethylenedioxythiophene) were then applied. And the resulting supercapacitor demonstrated power and energy densities of 2,715 watts per kilogram and 22 watt-hours per kilogram -- enough to operate a heart rate monitor, LEDs or a Bluetooth module. The researchers tested the device's durability and found that it performed well even after being compressed more than 100 times.


Wearable electronics are here—the most prominent versions are sold in the form of watches or sports bands. But soon, more comfortable products could become available in softer materials made in part with an unexpected ingredient: green tea. Researchers report in ACS' The Journal of Physical Chemistry C a new flexible and compact rechargeable energy storage device for wearable electronics that is infused with green tea polyphenols. Powering soft wearable electronics with a long-lasting source of energy remains a big challenge. Supercapacitors could potentially fill this role—they meet the power requirements, and can rapidly charge and discharge many times. But most supercapacitors are rigid, and the compressible supercapacitors developed so far have run into roadblocks. They have been made with carbon-coated polymer sponges, but the coating material tends to bunch up and compromise performance. Guruswamy Kumaraswamy, Kothandam Krishnamoorthy and colleagues wanted to take a different approach. The researchers prepared polymer gels in green tea extract, which infuses the gel with polyphenols. The polyphenols converted a silver nitrate solution into a uniform coating of silver nanoparticles. Thin layers of conducting gold and poly(3,4-ethylenedioxythiophene) were then applied. And the resulting supercapacitor demonstrated power and energy densities of 2,715 watts per kilogram and 22 watt-hours per kilogram—enough to operate a heart rate monitor, LEDs or a Bluetooth module. The researchers tested the device's durability and found that it performed well even after being compressed more than 100 times. More information: Chayanika Das et al. Elastic Compressible Energy Storage Devices from Ice Templated Polymer Gels treated with Polyphenols, The Journal of Physical Chemistry C (2017). DOI: 10.1021/acs.jpcc.6b12822 Abstract Design and fabrication of rechargeable energy storage devices that are robust to mechanical deformation is essential for wearable electronics. We report the preparation of compressible supercapacitors that retain their specific capacitance after large compression and that recover elastically after at least a hundred compression–expansion cycles. Compressible supercapacitors are prepared using a facile, scalable method that readily yields centimeter-scale macroporous objects. We ice template a solution of polyethylenimine in green tea extract to prepare a macroporous cross-linked polymer gel (PG) whose walls are impregnated with green tea derived polyphenols. As the PG is insulating, we impart conductivity by deposition of gold on it. Gold deposition is done in two steps: first, silver nanoparticles are formed on the PG walls by in situ reduction by polyphenols and then gold films are deposited on these walls. Gold coated PGs (GPGs) were used as electrodes to deposit poly(3,4-ethylenedioxythiophene) as a pseudocapacitive material. The specific capacitance of PEDOT coated GPGs (PGPG) was found to be 253 F/g at 1 A/g. PGPG could be compressed and expanded over a hundred cycles without any suffering mechanical failure or loss of capacitative performance. The capacitance was found to be 243 F/g upon compressing the device to 25% of its original size (viz. compressive strain = 75%). Thus, even large compression does not affect the device performance. This device shows power and energy densities of 2715 W/kg and 22 Wh/kg, respectively, in the uncompressed state. The macroporous nature of PGPG makes it possible to fill the PGPG pores with gel electrolyte. We report that the gel electrolyte filled supercapacitor exhibited a specific capacitance of 200 F/g, which increased by 4% upon 75% compression.


News Article | February 15, 2017
Site: www.eurekalert.org

Wearable electronics are here -- the most prominent versions are sold in the form of watches or sports bands. But soon, more comfortable products could become available in softer materials made in part with an unexpected ingredient: green tea. Researchers report in ACS' The Journal of Physical Chemistry C a new flexible and compact rechargeable energy storage device for wearable electronics that is infused with green tea polyphenols. Powering soft wearable electronics with a long-lasting source of energy remains a big challenge. Supercapacitors could potentially fill this role -- they meet the power requirements, and can rapidly charge and discharge many times. But most supercapacitors are rigid, and the compressible supercapacitors developed so far have run into roadblocks. They have been made with carbon-coated polymer sponges, but the coating material tends to bunch up and compromise performance. Guruswamy Kumaraswamy, Kothandam Krishnamoorthy and colleagues wanted to take a different approach. The researchers prepared polymer gels in green tea extract, which infuses the gel with polyphenols. The polyphenols converted a silver nitrate solution into a uniform coating of silver nanoparticles. Thin layers of conducting gold and poly(3,4-ethylenedioxythiophene) were then applied. And the resulting supercapacitor demonstrated power and energy densities of 2,715 watts per kilogram and 22 watt-hours per kilogram -- enough to operate a heart rate monitor, LEDs or a Bluetooth module. The researchers tested the device's durability and found that it performed well even after being compressed more than 100 times. The authors acknowledge funding from the University Grants Commission of India, the Council of Scientific and Industrial Research (India) and the Board of Research in Nuclear Sciences (India). The abstract that accompanies this study is available here. The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. ACS does not conduct research, but publishes and publicizes peer-reviewed scientific studies. Its main offices are in Washington, D.C., and Columbus, Ohio. To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.


News Article | February 22, 2017
Site: phys.org

Unai Alvarez-Rodriguez is a researcher in the Quantum Technologies for Information Science (QUTIS) research group attached to the UPV/EHU's Department of Physical Chemistry, and an expert in quantum information technologies. Quantum information technology uses quantum phenomena to encode computational tasks. Unlike classical computation, quantum computation "has the advantage of not being limited to producing registers in values of zero and one," he said. Qubits, the equivalent of bits in classical computation, can take values of zero, one or both at the same time, a phenomenon known as superposition, which "gives quantum systems the possibility of performing much more complex operations, establishing a computational parallel on a quantum level, and offering better results than classical computation systems," he added. The research group to which Alvarez-Rodriguez belongs decided to focus on imitating biological processes. "We thought it would be interesting to create systems capable of emulating certain properties exclusive of living entities. In other words, we were seeking to design quantum information protocols whose dynamics were analogous to these properties." The processes they chose to imitate by means of quantum simulators were natural selection, memory and intelligence. This led them to develop the concept of quantum biomimetics. They recreated a natural selection environment in which there were individuals, replication, mutation, interaction with other individuals and the environment, and a state equivalent to death. "We developed this final mechanism so that the individuals would have a finite lifetime," said the researcher. So by combining all these elements, the system has no single clear solution: "We approached the natural selection model as a dispute between different strategies in which each individual would be a strategy for resolving the problem, the solution would be the strategy capable of dominating the available space." The mechanism to simulate memory, on the other hand, consists of a system governed by equations. But equations display a dependence on their previous and future states, so the way in which the system changes "does not only depend on its state right now, but on its state five minutes ago, and where it is going to be in five minutes' time," explained Alvarez-Rodriguez. Finally, in the quantum algorithms relating to learning processes, they developed mechanisms to optimize well-defined tasks, to improve classical algorithms, and to improve the error margins and reliability of operations. "We managed to encode a function in a quantum system but not to write it directly; the system did it autonomously, we could say that it 'learned' by means of the mechanism we designed so that it would happen. That is one of the most novel advances in this research," he said. From computational models to the real world All these methods and protocols developed in his research have provided the means to resolve all kinds of systems. Alvarez-Rodriguez says that the memory method can be used to resolve highly complex systems: "It could be used to study quantum systems in different ambient conditions, or on different scales in a more accessible, more cost-effective way." With respect to natural selection, "more than anything we have come up with a quantum mechanism on which self-replicating systems could be based and which could be used to automate processes on a quantum scale." And finally, as regards learning, "we have come up with a way of teaching a machine a function without having to insert the result beforehand. This is something that is going to be very useful in the years to come, and we will get to see it," he said. All the models developed in the research were computational models. But Alvarez-Rodriguez has made it clear that one of the main ideas of his research group is that "science takes place in the real world. Everything we do has a more or less direct application. Despite having been conducted in theoretical mode, the simulations we have proposed are designed so that they can be carried out in experiments, on different types of quantum platforms, such as trapped ions, superconducting circuits and phototonic waveguides, among others. To do this, we had the collaboration of the experimental groups." Explore further: Quantum RAM: Modelling the big questions with the very small


News Article | February 21, 2017
Site: www.24-7pressrelease.com

MUNSTER, GERMANY, February 21, 2017-- Klaus Funke is a celebrated Marquis Who's Who biographee. As in all Marquis Who's Who biographical volumes, individuals profiled are selected on the basis of current reference value. Factors such as position, noteworthy accomplishments, visibility, and prominence in a field are all taken into account during the selection process.Marquis Who's Who, the world's premier publisher of biographical profiles, is proud to name Klaus Funke a Lifetime Achiever. An accomplished listee, Klaus Funke celebrates many years' experience in his professional network, and has been noted for achievements, leadership qualities, and the credentials and successes he has accrued in his field.Dr. Funke has recently retired from educating students at the University of Münster in Germany, as a professor of physical chemistry.Numerous societies dedicated to promoting the research of chemistry and physics have honored Dr. Funke for his achievements. The German Physical Society presented him with the prestigious Walter-Schottky Prize. He was also awarded the Wilhelm Jost Memorial Lecture of the Bunsen Society for Physical Chemistry. Marquis Who's Who has also recognized Dr. Funke for his contributions with inclusion in Who's Who in the World and Who's Who in Science and Engineering.In recognition of outstanding contributions to his profession and the Marquis Who's Who community, Klaus Funke has been featured on the Marquis Who's Who Lifetime Achievers website. Please visit http://whoswholifetimeachievers.com/2017/01/02/klaus-funke/ to view this distinguished honor.About Marquis Who's Who :Since 1899, when A. N. Marquis printed the First Edition of Who's Who in America , Marquis Who's Who has chronicled the lives of the most accomplished individuals and innovators from every significant field of endeavor, including politics, business, medicine, law, education, art, religion and entertainment. Today, Who's Who in America remains an essential biographical source for thousands of researchers, journalists, librarians and executive search firms around the world. Marquis publications may be visited at the official Marquis Who's Who website at www.marquiswhoswho.com

Loading Physical Chemistry collaborators
Loading Physical Chemistry collaborators