plant the right crop in the right place (Nanowerk News) Corn, wheat and rapeseed can be used to produce biofuels, such as bioethanol and biodiesel.
According to recent findings by environmental scientists at Radboud University, the location of the agricultural lands used to grow these biofuel crops has a major impact on the greenhouse gas emission they ultimately produce.
The study that arrived at this conclusion is due to be published By nature Climate change("Greenhouse gas payback times for crop-based biofuels".
"This figure shows the duration of the payback times for greenhouse gases produced by corn-based bioethanol per intensively farmed crop location,
i e. where fertilizers and irrigation are used. While intensive crop farming results in greater greenhouse gas emission, it also increases the yields of crops used to produce biofuels and,
ultimately, reduces emission levels. To increase production of biofuels from crops, such as corn and wheat,
natural areas need to make way for agricultural land. The initial result of this is an increase in greenhouse gas emission.
Using a global model, Pieter Elshout and fellow environmental scientists at Radboud University have demonstrated how long it takes for the advantages that biofuels offer over fossil fuels to earn a return on this initial emission On the global scale,
the average payback time for greenhouse gases is nineteen years. This figure shows the duration of the payback times for greenhouse gases produced by corn-based bioethanol,
per extensively farmed crop location, i e. where fertilizers and irrigation are used not. While extensive crop farming reduces greenhouse gas emission,
it also yields smaller crops for producing biofuels. From Western europe to the tropics Elshout, a Phd candidate at Radboud University, explains:
Nineteen years sounds like a long time, but in farming terms, its not all that long.
Furthermore, that figure is a global average. In Western europe, that period is considerably shorter, sometimes spanning just a few years.
In the tropics, however, it can extend past a hundred years. The model demonstrates that the location of biofuel crops has a significant impact on greenhouse gas emission more so than does the type of crop
or crop management (i e. the amount of fertilizers and irrigation used). First global-scale model Our model, Elshout continues,
is the first that offers a global, spatially-explicit overview of biogenic gas emission resulting from crops used to produce biofuels.
In developing this model, our calculations of the durations of payback times took account of the entire production chain for fossil fuels and biofuels with the accompanying greenhouse emissions.
This global model is applicable to first-generation biofuels. These include bioethanol from corn, wheat and sugar cane,
as well as biodiesel from soybeans and rapeseed. Food for discussion These results will contribute an angle of nuance to the current debate on biofuels in The netherlands.
In a follow-up study on biofuel crop farming Elshout and his colleagues hope to investigate the payback times related to the impact on biodiversity y
#Controlling swarms of robots with light and a single finger (w/video)( Nanowerk News) Using a smart tablet and a red beam of light,
Georgia Institute of technology researchers have created a system that allows people to control a fleet of robots with the swipe of a finger.
A person taps the tablet to control where the beam of light appears on a floor. The swarm robots then roll toward the illumination,
When the person swipes the tablet to drag the light across the floor the robots follow.
If the operator puts two fingers in different locations on the tablet, the machines will split into teams
Using a smart tablet and a red beam of light, Georgia Institute of technology researchers have created a system that allows people to control a fleet of robots with the swipe of a finger.
A person taps the tablet to control where the beam of light appears on a floor. The swarm robots then roll toward the illumination,
When the person swipes the tablet to drag the light across the floor the robots follow.
If the operator puts two fingers in different locations on the tablet, the machines will split into teams
The new Georgia Tech algorithm that fuels this system demonstrates the potential of easily controlling large teams of robots,
which is relevant in manufacturing, agriculture and disaster areas.""It's not possible for a person to control a thousand
or a million robots by individually programming each one where to go, "said Magnus Egerstedt, Schlumberger Professor in Georgia Tech's School of Electrical and Computer engineering."
"Instead, the operator controls an area that needs to be explored. Then the robots work together to determine the best ways to accomplish the job."
which an operator sends a large fleet of machines into a specific area of a tsunami-ravaged region.
The Georgia Tech model is different from many other robotic coverage algorithms because it's not static.
The tablet-based control system has one final benefit: it was designed with everyone in mind. Anyone can control the robots,
"In the future, farmers could send machines into their fields to inspect the crops, "said Georgia Tech Ph d. candidate Yancy Diaz-Mercado."
"Workers on manufacturing floors could direct robots to one side of the warehouse to collect items,
Scientists curve nanoparticle sheets into complex forms (Nanowerk News) Scientists have been making nanoparticles for more than two decades in two-dimensional sheets, three-dimensional crystals and random clusters.
But they have never been able to get a sheet of nanoparticles to curve or fold into a complex three-dimensional structure.
Now researchers from the University of Chicago, the University of Missouri and the U s. Department of energy's Argonne National Laboratory have found a simple way to do exactly that.
This highly magnified image of a folded gold nanoparticle scroll shows that even though researchers can fold the membrane,
Xiao-Min Lin et al, taken using a scanning electron microscope at the University of Chicago) The findings open the way for scientists to design membranes with tunable electrical,
magnetic and mechanical properties that could be used in electronics and may even have implications for understanding biological systems.
Working at the Center for Nanoscale Materials (CNM) and the Advanced Photon Source (APS), two DOE Office of Science User Facilities located at Argonne,
the team got membranes of gold nanoparticles coated with organic molecules to curl into tubes when hit with an electron beam.
Equally importantly they have discovered how and why it happens. The scientists coat gold nanoparticles of a few thousand atoms each with an oil-like organic molecule that holds the gold particles together.
When floated on water the particles form a sheet; when the water evaporates, it leaves the sheet suspended over a hole.
Its almost like a drumhead, says Xiao-Min Lin, the staff scientist at the Center for Nanoscale Materials who led the project.
But its a very thin membrane made of a single layer of nanoparticles. To their surprise,
when the scientists put the membrane into the beam of a scanning electron microscope, it folded.
It folded every time, and always in the same direction. That got our curiosity up,
so they end up distributing themselves in a nonuniform way across the top and bottom layers of the nanoparticle sheet.
When the electron beam hits the molecules on the surface it causes them to form an additional bond with their neighbors,
creating an asymmetrical stress that makes the membranes fold. Argonne researchers are able to fold gold nanoparticle membranes in a specific direction using an electron beam
because two sides of the membrane are different. Image: Xiao-Min Lin et al, taken at Argonnes Electron microscopy Center.
Subramanian Sankaranarayanan and Sanket Deshmukh at CNM used the high-performance computing resources at DOES National Energy Research Scientific Computing Center and the Argonne Leadership Computing Facility (ALCF), both
DOE Office of Science User Facilities, to analyze the surface of the nanoparticles. They discovered that the amount of surface covered by the organic molecules
and the molecules mobility on the surface both have an important influence on the degree of asymmetry in the membrane.
Fernando Bresme, professor of chemical physics at the Imperial College in London and a leading theorist on soft matter physics.
They advance significantly our ability to make new nanostructures with controlled shapes. In principle, scientists could use this method to induce folding in any nanoparticle membrane that has an asymmetrical distribution of surface molecules.
Said Lin, You use one type of molecule that hates water and rely on the water surfaces to drive the molecules to distribute non-uniformly,
#Combining graphene and nanotubes to make digital switches Graphene has been called a wonder material, capable of performing great and unusual material acrobatics.
Boron nitride nanotubes are no slackers in the materials realm either, and can be engineered for physical and biological applications.
However, on their own, these materials are terrible for use in the electronics world. As a conductor, graphene lets electrons zip too fasthere no controlling
or stopping themhile boron nitride nanotubes are so insulating that electrons are rebuffed like an overeager dog hitting the patio door.
But together, these two materials make a workable digital switch which is the basis for controlling electrons in computers, phones, medical equipment and other electronics.
Yoke Khin Yap, a professor of physics at Michigan Technological University, has worked with a research team that created these digital switches by combining graphene and boron nitride nanotubes.
The journal Scientific Reports recently published their work("Switching Behaviors of Graphene-Boron nitride nanotube Heterojunctions"."he question is:
How do you fuse these two materials together? Yap says. The key is in maximizing their existing chemical structures
and exploiting their mismatched features. Nanoscale Tweaks Graphene is a molecule-thick sheet of carbon atoms;
the nanotubes are made like straws of boron and nitrogen. Yap and his team exfoliate graphene
and modify the material surface with tiny pinholes. Then they can grow the nanotubes up and through the pinholes.
Meshed together like this, the material looks like a flake of bark sprouting erratic, thin hairs. hen we put these two aliens together,
explaining that it important that the materials have lopsided band gaps, or differences in how much energy it takes to excite an electron in the material. hen we put them together,
you form a band gap mismatchhat creates a so-called otential barrierthat stops electrons. The band gap mismatch results from the materialsstructure:
graphene flat sheet conducts electricity quickly, and the atomic structure in the nanotubes halts electric currents.
This disparity creates a barrier, caused by the difference in electron movement as currents move next to and past the hairlike boron nitride nanotubes.
These points of contact between the materialsalled heterojunctionsre what make the digital on/off switch possible. magine the electrons are like cars driving across a smooth track,
Yap says. hey circle around and around, but then they come to a staircase and are forced to stop.
Yap and his research team have shown also that because the materials are respectively so effective at conducting
or stopping electricity, the resulting switching ratio is high. In other words, how fast the materials can turn on
and off is several orders of magnitude greater than current graphene switches. In turn, this speed could eventually quicken the pace of electronics and computing.
Solving the Semiconductor Dilemma To get to faster and smaller computers one day, Yap says this study is a continuation of past research into making transistors without semiconductors.
The problem with semiconductors like silicon is that they can only get so small, and they give off a lot of heat;
the use of graphene and nanotubes bypasses those problems. In addition, the graphene and boron nitride nanotubes have the same atomic arrangement pattern,
or lattice matching. With their aligned atoms, the graphene-nanotube digital switches could avoid the issues of electron scattering. ou want to control the direction of the electrons,
Yap explains, comparing the challenge to a pinball machine that traps, slows down and redirects electrons. his is difficult in high speed environments,
and the electron scattering reduces the number and speed of electrons. Much like an arcade enthusiast, Yap says he
and his team will continue trying to find ways to outsmart or change the pinball setup of graphene to minimize electron scattering.
And one day all their tweaks could make for faster computersnd digital pinball gamesor the rest of us t
#Compact optical data transmission Compact optical transmission possibilities are of great interest in faster and more energy-efficient data exchange between electronic chips.
One component serving this application is the Mach-Zehnder modulator (MZM) which is able to convert electronic signals into optical signals.
which converts digital electrical signals into optical signals at a rate of up to 108 gigabit per second,
Optical technologies offer an enormous potential especially in transmitting data between computer chips, explains Manfred Kohl of the KIT.
Nano Scale Disruptive Silicon-Plasmonic Platform for Chip-to-Chip Interconnection, developed the plasmonic modulator (an electric-to-optical converter)
Compact optical transmitter and receiver units could exceed the speed limits of present-day electronic systems and help get rid of the bottlenecks in data centers.
Each modulator is made up of a metal-insulator-metal waveguide with a gap approximately 80 nanometers wide
and filled with an electro-optical polymer, and sidewalls made of gold which, at the same time, act as electrodes.
The electrodes carry a voltage which is modulated in line with the digital data. The electro-optical polymer changes its index of refraction as a function of the voltage.
The waveguide and the coupler made of silicon route the two parts of a split light beam to the gaps or from the gaps.
In the respective gap the light beams of the waveguides initiate electromagnetic surface waves, the so-called surface plasmons.
The voltage applied to the polymer modulates the surface waves. Modulation is different in both gaps but coherent,
as the same voltage is applied with different polarities. After passing through the gaps, the surface waves initially enter the output optical waveguides as modulated light beams
and are superimposed then. The result is a light beam in whose intensity (amplitude), the digital information was encoded.
In the experiment, the MZM works reliably over the entire spectral range of the broadband optical fiber networks of 1500 1600 nanometers at an electric bandwidth of 70 gigahertz with data flows of up to 108 gigabit per second.
The large depth of modulation is a consequence of the high manufacturing accuracy in silicon technology.
The MZM can also be made by means of the widespread CMOS-processes in microelectronics, and thus can easily be integrated into current chip architectures.
At the present time, some 10 percent of the electricity in Germany is consumed by information and communication technologies, such as computers and smart phones of users,
but also by the servers in large computer centers. As data traffic grows exponentially, new approaches are necessary to increase throughput and, at the same time, curb power consumption.
Plasmonic components could make a decisive contribution to this end. The NAVOLCHI EU project serves to use the interaction of light
and electrons in metal surfaces to develop novel components for optical data transmission between chips. The project is funded under the 7th Research Framework Programme of the European union
and has a budget of EUR 3. 4 million n
#Artificial blood vessels become resistant to thrombosis Scientists from ITMO University developed artificial blood vessels that are not susceptible to blood clot formation.
The achievement was made possible by a new generation of drug-containing coating applied to the inner surface of the vessel.
The results of the study were published in the Journal of Medicinal Chemistry("Synthesis of Thrombolytic Solel Coatings:
Toward Drug-Entrapped Vascular Grafts"."Surgery, associated with cardiovascular diseases, such as ischemia, often require the implantation of vascular grafts-artificial blood vessels,
aimed at restoring the blood flow in a problematic part of the circulatory system. A serious disadvantage of vascular grafts is their tendency to get blocked due to clot formation,
which results in compulsory and lifelong intake of anticoagulants among patients and sometimes may even require an additional surgical intervention.
In the study, a research team led by Vladimir Vinogradov, head of the International Laboratory of Solution Chemistry of Advanced Materials and Technologies at ITMO University proposed a solution to the problem.
The team managed to synthesize a thin film made of densely packed aluminum oxide nanorods blended with molecules of a thrombolytic enzyme (urokinase-type plasminogen activator).
) Adhered to the inner surface of a vascular graft, the film causes the parietal area of the graft to get filled with a stable concentration of a substance, called plasmin,
which is capable of dissolving the appearing clots. The unique properties of the film arise from its structure,
The matrix protects the plasminogen activator from the aggressive environment of the organism, at the same time preserving the ability of the enzyme to interact with certain external agents through a system of pores.
they actively release medicine into the blood. The lifetime of such grafts is determined often by the amount of drug stored within the graft,
but to any kind of implants. You just need to take the right kind of drug. For example, after the implantation of an artificial ureter, urease crystals often start to grow inside
and doctors do not know how to deal with this problem. It is possible to apply a similar drug-containing coating that dissolves urease.
The same approach may be used for kidney or liver surgery, but these are plans for the future,
"concludes Vladimir Vinogradov d
#5 billion light years across: the largest feature in the universe A Hungarian-US team of astronomers have found
report their work in a paper in Monthly Notices of the Royal Astronomical Society("A giant ringlike structure at 0. 78<z<0. 86 displayed by GRBS").
releasing as much energy in a few seconds as the Sun does over its 10 billion year lifetime.
-and ground-based observatories (see the Gamma ray Burst Online Index at http://www. astro. caltech. edu/grbox/grbox. php).
This osmological Principleis backed up by observations of the early universe and its microwave background signature
#Nanotechnology developed to help treat heart attack and stroke Australian researchers funded by the National Heart Foundation are a step closer to a safer
and more effective way to treat heart attack and stroke via nanotechnology. The research jointly lead by Professor Christoph Hagemeyer, Head of the Vascular Biotechnology Laboratory at Baker IDI Heart and Diabetes Institute and Professor Frank Caruso,
an ARC Australian Laureate Fellow in the Department of Chemical and Biomolecular engineering at the University of Melbourne, was published today in Advanced Materials("Multifunctional Thrombin-Activatable Polymer Capsules for Specific Targeting to Activated Platelets").
"Professor Hagemeyer said this latest step offers a revolutionary difference between the current treatments for blood clots and
what might be possible in the future. This life saving treatment could be administered by paramedics in emergency situations without the need for specialised equipment as is currently the case. ee created a nanocapsule that contains a clot-busting drug.
The drug-loaded nanocapsule is coated with an antibody that specifically targets activated platelets, the cells that form blood clots,
Professor Hagemeyer said. nce located at the site of the blood clot, thrombin (a molecule at the centre of the clotting process) breaks open the outer layer of the nanocapsule,
releasing the clot-busting drug. We are effectively hijacking the blood clotting system to initiate the removal of the blockage in the blood vessel,
he said. Professor Frank Caruso from the Melbourne School of engineering said the targeted drug with its novel delivery method can potentially offer a safer alternative with fewer side effects for people suffering a heart attack
or stroke. p to 55,000 Australians experience a heart attack or suffer a stroke every year. bout half of the people who need a clot-busting drug can use the current treatments
because the risk of serious bleeding is too high, he said i
#Molecular tinkering doubles cancer drug's efficacy The drug paclitaxel has been used for decades to fight breast, ovarian, lung and other cancers.
But its effectiveness has been limited by its small molecular size and insolubility in water--properties that allow the body to clear the drug too quickly,
reducing its accumulation in tumors. Many molecular packaging systems have been developed to deliver the drug while counteracting these effects, with a protein-bound version of the drug called Abraxane currently the leading therapy.
But Ashutosh Chilkoti, professor and chair of the Department of Biomedical engineering at Duke university thought his team could do better.
By surrounding molecules of paclitaxel with self-assembling spheres composed of amino acids, the Duke team doubled tumor exposure to the drug compared to Abraxane
while simultaneously reducing its effects on healthy tissue. This kept mice with tumors alive significantly longer and, in some cases, completely eradicated the tumors.
The results were published online in Nature Communications on August 4, 2015("A paclitaxel-loaded recombinant polypeptide nanoparticle outperforms Abraxane in multiple murine cancer models".
"The big difference between Abraxane and the Duke approach is the types of molecular bonds that are formed.
In Abraxane, the paclitaxel is surrounded physically by albumin, a common blood protein. In the new packaging system, multiple copies of the drug are bonded chemically to an amino acid polypeptide,
forming a water-soluble nanoparticle with the drug hidden in its core. These nanoparticles are highly soluble in blood
and are the perfect size to penetrate and accumulate in tumors where they take advantage of a tumor's acidic environment."
"The chemical bonds holding the polypeptide cage together are stable in blood, but dissolve in a tumor's lower ph levels,"said Jayanta Bhattacharyya, senior researcher in Chilkoti's lab and first author on the paper."
"This delivers the drug directly to the tumor and helps prevent it from randomly absorbing into healthy tissue, reducing side effects."
"To test their system, Chilkoti, Bhattacharyya and their colleagues used two groups of mice. The first group had human breast cancer growing in their own mammary glands.
While none of the mice treated with Abraxane survived past 85 days, most of the mice treated with the new packaging system survived past 100 days.
A second group of mice had human prostate tumors growing under their skin. Similarly, while they did not survive past 60 days
with some experiencing a complete cure. As the mortality rates suggest the Duke technology showed a higher concentration of paclitaxel in the tumors with more staying power than Abraxane,
while simultaneously showing much lower levels throughout the rest of the mice's bodies.""Clearly in the animal model there is a night and day difference,
"said Neil Spector, an oncologist at Duke Medicine familiar with the work.""But it's not just the increase in clinical efficacy
it's also the improvement in targeting and reduction in toxicity, which is just icing on the cake.
it could be a game-changer for cancer therapy.""In future work, Chilkoti and coworkers will begin applying the packaging system to other cancer drugs with the goal of developing a"one size fits all"technology to improve the effectiveness of many other cancer drugs s
#Atomic view of microtubules Microtubules, hollow fibers of tubulin protein only a few nanometers in diameter, form the cytoskeletons of living cells
and play a crucial role in cell division (mitosis) through their ability to undergo rapid growth and shrinkage, a property called"dynamic instability."
"Through a combination of high-resolution cryo-electron microscopy (CRYO EM) and a unique methodology for image analysis, a team of researchers with Berkeley Lab and the University of California (UC) Berkeley has produced an atomic view of microtubules
and reform into spindles that are used by the dividing cell to move chromosomes. For chromosome migration to occur,
the microtubules attached to them must disassemble, carrying the chromosomes in the process. The dynamic instability that makes it possible for microtubules to transition from a rigid polymerized
or"assembled"nucleotide state to a flexible depolymerized or"disassembled"nucleotide state is driven by guanosine triphosphate (GTP) hydrolysis in the microtubule lattice."
a biophysicist with Berkeley Lab's Life sciences Division who led this research. Nogales, who is also a professor of biophysics
and structural biology at UC Berkeley and investigator with the Howard hughes medical institute, is a leading authority on the structure and dynamics of microtubules.
In this latest study, she and her group used CRYO EM in which protein samples are flash-frozen at liquid nitrogen temperatures to preserve their natural structure,
to determine microtubule structures in different nucleotide states with and without EB3. With CRYO EM and their image analysis methodology, they achieved a resolution of 3. 5 Angstroms, a record for microtubules.
For perspective, the diameter of a hydrogen atom is about 1. 0 Angstroms.""We can now study the atomic details of microtubule polymerization
and depolymerization to develop a complete description of microtubule dynamics, "Nogales says. Beyond their importance to our understanding of basic cell biology, microtubules are a major target for anticancer drugs, such as Taxol,
which can prevent the transition from growing to shrinking nucleotide states or vice versa.""A better understanding of how microtubule dynamic instability is regulated could open new opportunities for improving the potency and selectivity of existing anticancer drugs,
#Giving robots a more nimble grasp (w/video) Most robots on a factory floor are fairly ham-handed:
using the environment as a helping hand. The team, led by Alberto Rodriguez, an assistant professor of mechanical engineering,
and graduate student Nikhil Chavan-Dafle, has developed a model that predicts the force with which a robotic gripper needs to push against various fixtures in the environment
in order to adjust its grasp on an object. For instance, if a robotic gripper aims to pick up a pencil at its midpoint,
it could use the environment to adjust its grasp. Instead of releasing the pencil and trying again
and push the pencil against a nearby wall, just enough to slide the robot gripper closer to the pencil midpoint. robotic gripper A simple robotic gripper can adjust its grip using the environment.
Here, a robot grips a rod lightly while pushing it against a tabletop. This allows the rod to rotate in the robot fingers.
Image courtesy of the researchers) Partnering robots with the environment to improve dexterity is an approach Rodriguez calls xtrinsic dexterityas opposed to the intrinsic dexterity of,
But programming such intrinsic dexterity in a robotic hand is extremely tricky, significantly raising a robot cost.
With Rodriguez new approach, existing robots in manufacturing, medicine, disaster response, and other gripper-based applications may interact with the environment,
in a cost-effective way, to perform more complex maneuvers. hasing the human hand is still a very valid direction in robotics,
which the environment may be exploited to increase the dexterity of simple robotic grippers. In ongoing work
his group is looking for ways in which a robot might use gravity to toss
In this most recent paper, the group investigates an approach to extrinsic dexterity called rehensile pushingexploiting fixtures in the environment to manipulate a grasped object. ee sort of outsourcing that dexterity that you don have in the gripper to the environment and the arm,
Rodriguez explains. nstead of dexterity that intrinsic to the hand, it extrinsic, in the environment.
and between the object and the environment, as well as the object mass, inertia, and shape. MIT engineers have devised a way to give more dexterity to simple robotic grippers using the environment as a helping hand.
Their model predicts the force with which a robotic gripper must push against surrounding fixtures
Robot footage and additional editing by Nikhil Chavan-Dafle and Alberto Rodriguez) xploiting the environmentin its current iteration, the model predicts the force a gripper must exert, on the object and the environment,
How do you engineer fixtures in the environment so that a robot motions are more reliable,
A surgical robot may push a scalpel against an operating table to adjust its grip, while a forensic robot in the field may angle a piece of evidence against a nearby rock to better examine it. xploiting the environment is,
and will be, important for robots and the research community, Rodriguez says. ny applications where you have limitations in terms of payload or cost or complexity, areas like manufacturing,
or surgery, or field operations, or even space exploration whenever you have a gripper that is not dexterous like a human hand,
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