#Scientists get 1 step closer to finding how to repair damaged nerve cells A team of researchers at the IRCM led by Frdric Charron, Phd,
in collaboration with bioengineers at Mcgill University, uncovered a new kind of synergy in the development of the nervous system,
Their breakthrough, published today in the scientific journal PLOS Biology("Integration of Shallow Gradients of Shh
and Netrin-1 Guides Commissural Axons"),could eventually help develop tools to repair nerve cells following injuries to the nervous system (such as the brain and spinal cord).
To do so, they studied the relative change in concentration of guidance cues in the neuron's environment
"says Tyler F. W. Sloan, Phd student in Dr. Charron's laboratory and first author of the study."
"In collaboration with the Program in Neuroengineering at Mcgill University, Dr. Charron's team developed an innovative technique to recreate the concentration gradients of guidance cues in vitro,
that is to say they can study the developing axons outside their biological context.""This new method provides us with several benefits
and obtain extremely useful quantitative data, "adds Sloan.""It combines knowledge from the field of microfluidics,
which uses fluids at a microscopic scale to miniaturize biological experiments, with the cellular, biological and molecular studies we conduct in laboratories.""
""This is true multidisciplinary work, and an excellent example of what the Program in Neuroengineering aims to accomplish in situations where neurobiologists like myself have a specific question they want to address,
"Thus, thanks to this unique program, we teamed up with Mcgill's bioengineers and microfluidic and mathematical modelling experts to create the device required for our study.""
""This scientific breakthrough could bring us closer to repairing damaged nerve cells following injuries to the central nervous system,"states Dr. Charron."
"A better understanding of the mechanisms involved in axon guidance will offer new possibilities for developing techniques to treat lesions resulting from spinal cord injuries,
and possibly even neurodegenerative diseases.""Injuries to the central nervous system affect thousands of Canadians every year and can lead to lifelong disabilities.
Most often caused by an accident, stroke or disease, these injuries are currently very difficult to repair.
Research is required therefore for the development of new tools to repair damage to the central nervous system m
#Nanoparticles provide novel way to apply drugs to dental plaque Therapeutic agents intended to reduce dental plaque
and prevent tooth decay are removed often by saliva and the act of swallowing before they can take effect.
But a team of researchers has developed a way to keep the drugs from being washed away.
Dental plaque is made up of bacteria enmeshed in a sticky matrix of polymersa polymeric matrixthat is attached firmly to teeth.
The researchers, led by Danielle Benoit at the University of Rochester and Hyun Koo at the University of Pennsylvanias School of dental medicine
Their findings have been published in the journal ACS Nano("ph-Activated Nanoparticles for Controlled Topical Delivery of Farnesol To Disrupt Oral Biofilm Virulence".
"Farnesol is released from the nanoparticle carriers into the cavity-causing dental plaque. Graphic by Michael Osadciw/University of Rochester.
click on image to enlarge) We had two specific challenges, said Benoit, an assistant professor of biomedical engineering.
We had to figure out how to deliver the antibacterial agent to the teeth and keep it there,
and also how to release the agent into the targeted sites. To deliver the agentknown as farnesolto the targeted sites,
the researchers created a spherical mass of particles, referred to as a nanoparticle carrier. They constructed the outer layer out of cationicor positively chargedsegments of the polymers.
For inside the carrier, they secured the drug with hydrophobic and ph-responsive polymers. The positively charged outer layer of the carrier is able to stay in place at the surface of the teeth
because the enamel is made up, in part of HA (hydroxyapatite), which is negatively charged. Just as oppositely charged magnets are attracted to each other,
the same is true of the nanoparticles and HA. Because teeth are coated with saliva, the researchers werent certain the nanoparticles would adhere.
But not only did the particles stay in place, they were also able to bind with the polymeric matrix
and stick to dental plaque. Since the nanoparticles could bind both to saliva-coated teeth and within plaque,
Benoit and colleagues used them to carry an antibacterial agent to the targeted sites. The researchers then needed to figure out how to effectively release the agent into the plaque.
A key trait of the inner carrier material is that it destabilizes at acidicor low phlevels such as 4. 5,
allowing the drug to escape more rapidly. And thats exactly what happens to the ph level in plaque
In other words, the nanoparticles release the drug when exposed to cavity-causing eating habitsprecisely when it is needed most to quickly stop acid-producing bacteria.
said Hyun Koo, a professor in the Department of Orthodontics and co-senior author of the work.
When the drug was administered without the nanoparticle carriers, there was no effect on the number of cavities and only a very small reduction in their severity.
But when it was delivered by the nanoparticle carriers, both the number and severity of the cavities were reduced.
as well as other biofilm-related diseases s
#A new breakthrough in thermoelectric materials French physicist Jean Charles Athanase Peltier discovered a key concept necessary for thermoelectric (TE) temperature control in 1834.
Since his work, there have been steady advancements in materials and design. Despite the technological sophistication Peltier devices, they are still less energy efficient than traditional compressor/evaporation cooling.
or Antimony-Telluride (Sb2te3) alloys and had a peak efficiency (zt) of 1. 1, meaning the electricity going in was only slightly less than the heat coming out.
Since the 1960's there have been incremental advancements in alloy technology used in Peltier devices.
In 2014, researchers in South korea at IBS Center for Integrated Nanostructure Physics along with Samsung Advanced Institute of technology, the Department of Nano Applied Engineering at Kangwon National University, the Department of energy Science
at Sungkyunkwan University, and Materials science department at California Institute of technology California, USA have formulated a new method for creating a novel and much more efficient TE alloy.
TE alloys are special because the metals have an incredibly high melting point. Instead of melting the metals to fuse them,
they are combined through a process called sintering which uses heat and/or pressure to join the small,
metallic granules. The joint team, including IBS researchers, used a process called liquid-flow assisted sintering
which combined all three antimony, bismuth and telluride granules into one alloy (Bi0. 5sb1. 5te3).
Additional melted tellurium was used as the liquid between the Bi0. 5sb1. 5te3 granules to help fuse them into a solid alloy,
and excess Te is expelled in the process. This schematic illustration shows the generation of dislocation arrays during the liquid-phase compaction process.
The Te liquid (red) between the Bi0. 5sb1. 5te3 grains flows out during the compacting process
Institute for Basic Science) By creating the alloy this way, the joints between the fused grains,
which have led to a decrease in both thermal and electrical conductivity. The new liquid-phase sintering creates grain boundaries
as electrical vehicles and personal electronic devices become more ubiquitous in our daily lives, it is becoming increasingly necessary to have more efficient systems for localized electrical power generation and effective cooling mechanisms.
This new thermoelectric alloy paves the way for the future of modern TE devices s
#Octopus-inspired robot is the fastest underwater robot based on the given power (w/video)( Nanowerk News) Scientists in Singapore have developed a new octopus-inspired robot
This first-ever ultra-fast propulsion and super-manoeuvrability demonstrated in underwater vehicles is unprecedented; and is the work of researchers and an engineer from the Singapore-MIT Alliance for Research and Technology (SMART.
The first author, originally from SMART, is now with the University of Southampton. L-R:
Polycarbonate skeleton of robot, testing apparatus, fully blown membrane (last two pix. click on image to enlarge) This ground-breaking research was published in Bioinspiration
& Biomemetics("Ultra-fast escape maneuver of an octopus-inspired robot) "and Nature("Robot zips away like an octopus")and validates the physics of shape change (that forms the basis of jet propulsion of cephalopods) to give additional thrust to underwater vehicles.
Inspired by the speed at which cephalopods like the octopus, flee from danger by inflating its mantle cavity with water to a bluff-body shape
The end result is a polycarbonate 3d printed streamlined skeleton which had no moving parts (Fig. 1) and no energy storage device other than a thin elastic outer membrane.
It works like blowing up a balloon and then releasing it to fly around the room. The 27-cm long robot is inflated with water and once released,
rapidly deflates by shooting the water out through an aperture at its base to power its propulsion.
while creating minimum turbulence an important feature in underwater research/survey vehicles. The skeleton within the robot keeps the final shape streamlined,
When a fish escapes by swimming fast, it bends its body and zooms through the water, losing some energy to the surrounding water
and recovering about 30%of the energy. An octopus, on the other hand, uses more effectively, energy recovery mechanism to power its ultra-fast escape,
and is able to recover more than 50%of the energy available at the beginning. Hence, rendering this octopus robot highly energy efficient.
Underwater'robot'with 3d printed hull and elastic membrane demonstrates ultra-fast escape inspired from Octopus.
Professor Michael Triantafyllou who is also the William I. Koch Professor of Marine Technology Professor of Mechanical and Ocean Engineering and Director of the Center for Ocean Engineering at MIT, explained:
With this fundamental understanding in fluid mechanics, our research will pave the way for future robots that require fast maneuvers to help us get close to something that moves fast
Currently, no autonomous underwater vehicle (AUV) can achieve this ultra-fast performance except torpedoes which require a lot of fuel.
With further R&d, future AUVS and other marine vehicles can adopt this mechanism to help it evade threats or track something fast stealthily underwater without the need for much energy.
and implementing the technology on marine vehicles s
#Engineers invent two-dimensional liquid (Nanowerk News) Where water and oil meet, a two-dimensional world exists.
Recently, a team from the Department of Chemical and Biomolecular engineering in the School of engineering and Applied science has shown how to do just that.
Their soft nanoparticles stick to the plane where oil and water meet, but do not stick to one another.
effectively acting as a 2-D liquid("Interactions and Stress Relaxation in Monolayers of Soft Nanoparticles at Fluid-Fluid Interfaces".
"The researchers created a 2-D liquid consisting of nanoparticles at the interface between a drop of oil and the surrounding water.
The researchers created a 2-D liquid consisting of nanoparticles at the interface between a drop of oil and the surrounding water.
The team, consisting of postdoctoral researcher Valeria Garbin, graduate student Ian Jenkins and professors Talid Sinno, John Crocker,
and Kathleen Stebe, also devised clever ways of measuring the properties of this unique system.
Their data will better inform computer simulations and potentially lead to applications in fields like nanomanufacturing and catalysis. We understand how particles work in 3-D,
Crocker says. If you put polymer chains on the surface that are attracted to the solvent,
the particles will bounce off each other and make a nice suspension, meaning you can do work with them.
However, people havent really done that in 2-D before. Even when particles are able to stay at the interface
The teams technique for surmounting this problem hinged on decorating their gold nanoparticles with surfactant, or soap-like, ligands.
zero-play flexure joints provide very fast response with 4g acceleration, operating frequencies up to 100 Hz (small signal),
The used-defined pivot point (center of rotation) can be changed on the fly by one software command for increased versatility.
and freely definable paths with high trajectory accuracy can easily be programmed with the included software tools.
and Light Extremely stiff carbon fiber components reduce the inertia and result in a high Eigenfrequency of 200hz, important for fast response, high operating frequencies,
The direct-drive hexapod comes with a powerful digital vector motion controller with open software architecture and hexapod-specific Software applications of the H-860kmag Linear Motor Hexapod Motion
-860kmag 6d hexapods. php? onl prweb About PI PI is a leading manufacturer of precision motion control equipment, piezo motors, air bearing stages and hexapod parallel-kinematics for semiconductor applications, photonics, bio-nano-technology and medical engineering.
PI has been developing and manufacturing standard & custom precision products with piezoceramic and electromagnetic drives for 4 decades.
PI is present worldwide with eight subsidiaries, R&d/engineering on 3 continents and total staff of 800
#Micro-magnetometer Nanowerk News) MIT researchers have developed a new, ultrasensitive magnetic-field detector that is 1, 000 times more energy-efficient than its predecessors.
It could lead to miniaturized, battery-powered devices for medical and materials imaging, contraband detection,
Magnetic-field detectors, or magnetometers, are used already for all those applications. But existing technologies have drawbacks:
Synthetic diamonds with nitrogen vacancies (NVS) defects that are extremely sensitive to magnetic fields have held long promise as the basis for efficient, portable magnetometers.
A diamond chip about one-twentieth the size of a thumbnail could contain trillions of nitrogen vacancies,
the Jamieson Career development Assistant professor in Electrical engineering and Computer science and one of the designers of the new device. e make use of almost all the pump light to measure almost all of the NVS.
The MIT researchers report their new device in the latest issue of Nature Physics("roadband Magnetometry and Temperature Sensing with a Light Trapping Diamond Waveguide".
a graduate student in electrical engineering who is advised by senior authors Englund and Danielle Braje, a physicist at MIT Lincoln Laboratory.
Theye joined by Englund students Matthew Trusheim and Carson Teale (who also at Lincoln Lab) and by Tim Schröder, a postdoc in MIT Research Laboratory of Electronics y
#Atomic structure identified in coherent interfaces between superhard materials of diamond and boron nitride (Nanowerk News) The research group led by Professor Yuichi Ikuhara (also appointed as a professor at Tokyo University), Associate professor Zhongchang Wang and Assistant professor Chunlin Chen at the Advanced Institute for Materials Research
, Tohoku University (AIMR), in collaboration with Group Leader Takashi Taniguchi at the National Institute for Materials science (NIMS) and Japan Fine Ceramics Center (JFCC), succeeded for the first time in identifying the atomic structure and bonding mechanism in coherent interfaces between diamond
, the hardest known material, and cubic boron nitride, the second hardest, using a state-of-the-art super-high-resolution scanning transmission electron microscope and first-principles calculation.
a and b) HAADF STEM images of c-BN/diamond interface viewed in direction parallel to 1-10 zone axis,(a) coherent area without defects,(b) area with defects,
(c and d) HAADF STEM images of c-BN/diamond interface viewed in direction parallel to 11-2 zone axis,(c) area without defects,
and (d) area with defects. Partial dislocations are observable. By comparing (c) and (d), a Burgers vector,
which characterizes partial dislocations, of 1/4 was determined. All scale bars are 0. 5 nm in length.
The research group has attempted to develop new functional materials by focusing on lattice defects in crystals
namely dislocation, grain boundaries and interfaces, analyzing their atomic structures, and controlling lattice defects. Through the concurrent use of atomic-resolution scanning transmission electron microscopy, for which technological breakthroughs were achieved in recent years,
and extensive theoretical calculation based on first principles, the group revealed that in coherent interfaces between diamond and cubic boron nitride,
This study was published in the online version of the UK scientific journal Nature Communications("Misfit accommodation mechanism at the heterointerface between diamond and cubic boron nitride
3-D images of nanoscale objects (w/video)( Nanowerk News) To design the next generation of optical devices, ranging from efficient solar panels to LEDS to optical transistors,
engineers will need a 3-dimensional image depicting how light interacts with these objects on the nanoscale.
thousandths the size of a grain of sand, in 3-D and with nanometer scale resolution.
The research is detailed in the current issue of Nature Nanotechnology("Nanoscale optical tomography with cathodoluminescence spectroscopy".
cathodoluminescence and tomography, enabling the generation of 3-D maps of the optical landscape of objects,
said study lead author Ashwin Atre, a graduate student in the lab group of Jennifer Dionne, an assistant professor of materials science and engineering.
The target object in this proof-of-principle experiment was coated a gold crescent 250 nanometers in diameter several hundred times as thin as a human hair.
they first imaged it using a modified scanning electron microscope. As the focused electron beam passed through the object
Each pixel in this image also contained information about the wavelength of emitted photons across visible and near-infrared wavelengths.
which light interacts with this nanometer scale object.""Interpreting a 2-D image, however, can be quite limiting,
We really wanted to improve upon that with our work.""To push the technique into the third dimension,
the engineers tilted the nanocrescent and rescanned it, collecting 2-D emission data at a number of angles,
By using tomography to combine this tilt-series of 2-D images, similar to how 2-D X-ray images of a human body are stitched together to produce a 3-D CT image,
This experimental map reveals sources of light emission in the structure with a spatial resolution on the order of 10 nanometers.
"This work could enable a new era of 3d optical imaging with nanometer scale spatial and spectral resolution,
who is an affiliate of the Stanford Institute for Materials and Energy Sciences at SLAC.
"For instance, it could be used in manufacturing LEDS to optimize the way light is emitted, or in solar panels to improve the absorption of light by the active materials."
"The technique could even be modified for imaging biological systems without the need for fluorescent labels.
In addition to Atre and Dionne, the research was authored co by Aitzol Garcia-Etxarri, a postdoctoral fellow at Stanford now at DIPC in Spain,
and he is the first graduate from Dionne's lab b
#Novel photolithographic technology that enables control over functional shapes of microstructures Professor Shin-Hyun Kim
and his research team in the Department of Chemical and Biomolecular engineering at Korea Advanced Institute of Science and Technology (KAIST) have developed a novel photolithographic technology enabling control over the functional shapes of micropatterns using oxygen diffusion.
The research was published online in the March 13th issue of Nature Communications("Dynamic designing of microstructures by chemical gradient-mediated growth)
especially in the semiconductor manufacturing industry. Conventional photolithography relied on photomasks which protected certain regions of the substrate from the input UV LIGHT.
Professor Kim research team discovered that: 1) the areas exposed to UV LIGHT lowered the concentration of oxygen
shape and size of the polymers. Based on these findings, the team developed a new photolithographic technology that enabled the production of micropatterns with three-dimensional structures in various shapes and sizes.
Professor Kim and his team proved this phenomenon both empirically and theoretically. Furthermore, by injecting an external oxygen source
and thus control the shape and size of the polymer. The use of the polymerization inhibitors enabled
and facilitated the fabrication of complex, three-dimensional micropatterns. Professor Kim said, hile 3d printing is considered an innovative manufacturing technology,
it cannot be used for mass-production of microscopic products. The new photolithographic technology will have a broad impact on both the academia and industry especially because existing,
His newest technology will enhance the manufacturing process of three-dimensional polymers which were considered difficult to be commercialized.
The research was dedicated also to the late Professor Seung-Man Yang of the Department of Chemical and Biomolecular engineering at KAIST.
He was considered one of the greatest scholars in Korea in the field of hydrodynamics and colloids.
#Multimetal nanoframes improve catalyst performance (Nanowerk News) A team of researchers has synthesized a highly active and durable class of electrocatalysts by exploiting the structural evolution of solid Pt-Ni bimetallic nanocrystals into porous
cage-like structures or nanoframes("Highly Crystalline Multimetallic Nanoframes with Three-dimensional Electrocatalytic Surfaces"."This novel material significantly enhanced catalytic activity for the oxygen reduction reaction--the splitting of an O2 molecule into two oxygen ions--that is critical to fuel cells and potentially other electrochemical applications.
The Impact This approach to synthesizing the material is a significant advance towards realizing electrocatalysts with superior catalytic properties and lower cost.
The open structure of the nanoframes addresses some of the major design criteria for advanced nanoscale electrocatalysts, namely, high surface-to-volume ratio, three-dimensional surface accessibility to reactants,
and optimal precious metal use. Researchers are optimistic that the approach can be applied readily to other multimetallic catalysts
potentially lowering the cost of catalytic material production. Summary Control of structure at the atomic level can precisely and effectively tune catalytic properties of materials, enabling enhancement of both activity and durability.
and the University of Wisconsin synthesized a highly active and durable class of electrocatalysts by exploiting the structural evolution of solid Pt-Ni bimetallic nanocrystals into porous cage-like structures or nanoframes.
The material was synthesized by exploiting the structural evolution of platinum-nickel (Pt-Ni) bimetallic nanocrystals into cage-like structures with a self-assembled Pt skin structure on the interior and exterior surfaces.
crystalline Ptni3 nanoparticles, are transformed in solution and at mild temperatures into Pt3ni nanoframes with surfaces that have three-dimensional molecular accessibility.
The Pt-rich edges of the starting Ptni3 nanoparticles are maintained in the final Pt3ni nanoframes.
Both the interior and exterior surfaces of this open framework structure are composed of a Pt-rich skin structure that exhibits enhanced oxygen reduction reaction activity.
The Pt3ni nanoframe catalysts achieved a more than 36-fold and 22-fold enhancement in two different measures of catalytic activity (mass and specific activities, respectively) for the oxygen reduction reaction in comparison to state-of-the-art
carbon-supported Pt catalysts (Pt/C) during prolonged exposure to reaction conditions. This work is a significant advance towards developing more efficient electrocatalysts for water-splitting reactions and fuel generation.
These electrocatalyst structures were applied to the hydrogen evolution reaction (HER), which is the crucial cathodic reaction in water-alkali electrolyzers,
The HER activity for highly crystalline Pt3nit-skin nanoframe surface was enhanced by almost one order of magnitude relative to Pt/C. Utilizing the spontaneous structural evolution of a bimetallic nanoparticle from solid polyhedra to hollow nanoframes with controlled size, structure,
and surface composition should be readily applicable to other multimetallic catalysts s
#Plant cell structure discovery could lead to improved renewable materials (Nanowerk News) Major steps forward in the use of plants for renewable materials,
energy and for building construction could soon arise, thanks to a key advance in understanding the structure of wood.
The step forward follows research by the Universities of Warwick and Cambridge and the unexpected discovery of a previously unknown arrangement of molecules in plant cell walls.
The paper("Probing the Molecular Architecture of Arabidopsis thaliana Secondary cell Walls Using Two-and Three-dimensional 13c Solid State Nuclear Magnetic resonance Spectroscopy")describing this work was Editors Choice for the American
ACS (click on image to enlarge) The researchers investigated the polymer xylan which comprises a third of wood matter.
Professor Ray Dupree from the University of Warwick, one of the researchs authors, says:""Using advanced NMR techniques we found that the xylan polymer,
which comprises about a third of wood, has unexpected an shape inside the plant cell walls"."The structure of the xylan was ascertained by creating 2d maps of the molecular structure of the woody stalks of thale cress in the UKS most advanced solid-state Nuclear Magnetic resonance (NMR) Facility, based at the University of Warwick.
Professor Paul Dupree of the University of Cambridge (son of Professor Ray Dupree) says"For the first time we have been able to study the arrangement of molecules in woody plant materials.
Plant cell walls provide the mechanical strength to plants. This major step forward in understanding the molecular architecture of plant cell walls will impact the use of plants for renewable materials
energy and for building construction"."Professors Ray and Paul Dupree have discussed the possibility of working together to solve outstanding questions in plant biochemistry for twenty years.
Only recently has it become possible due to the ability to grow suitable experimental plants at the University of Cambridge and the availability of the powerful NMR facility in Warwick.
Commenting on the use of the NMR Facility, co-researcher Professor Steven Brown of the University of Warwick says:
The NMR Facility is a flagship national success for shared equipment and multi-disciplinary research.
#Scientists a step closer to developing renewable propane (Nanowerk News) Researchers at The University of Manchester have made a significant breakthrough in the development of synthetic pathways that will enable renewable biosynthesis of the gas propane.
This research is part of a programme of work aimed at developing the next generation of biofuels.
In this latest study, published in the journal Biotechnology for Biofuels("A microbial platform for renewable propane synthesis based on a fermentative butanol pathway"),scientists at the Universitys Manchester Institute of Biotechnology (MIB
working with colleagues at Imperial College and University of Turku, have created a synthetic pathway for biosynthesis of the gas propane.
Their work brings scientists one step closer to the commercial production of renewable propane, a vital development as fossil fuels continue to dwindle.
Professor Nigel Scrutton, Director of the MIB, explains the significance of their work: The chemical industry is undergoing a major transformation as a consequence of unstable energy costs, limited natural resources and climate change.
Efforts to find cleaner, more sustainable forms of energy as well as using biotechnology techniques to produce synthetic chemicals are currently being developed at The University of Manchester.
Natural metabolic pathways for the renewable biosynthesis of propane do not exist but scientists at the University have developed an alternative microbial biosynthetic pathway to produce renewable propane.
The team led by Nigel Scrutton and Dr Patrik Jones from Imperial College, modified existing fermentative butanol pathways using an engineered enzyme variant to redirect the microbial pathway to produce propane as opposed to butanol.
The team was able to achieve propane biosynthesis creating a platform for next-generation microbial propane production.
Propane has very good physicochemical properties which allow it to be stored and transported in a compressed liquid form.
While under ambient conditions it is a clean-burning gas, with existing global markets and infrastructure for storage,
Professor Scrutton comments: This study focused on the construction and evaluation of alternative microbial biosynthetic pathways for the production of renewable propane.
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