How To Detect Cancer With a Urine Test

Researchers centered at Nagoya University (Japan) develop a nanowire device able to detect microscopic levels of urinary markers potentially implicated in cancerCells communicate with each other through a number of different mechanisms. Some of these mechanisms are well-known: in animals, for example, predatory threats can drive the release of norepinephrine, a hormone that travels through the bloodstream and triggers heart and muscle cells to initiate a “fight-or-flight” response. A far less familiar mode of cellular transport is the extracellular vesicle (EV). EVs can be thought of as small “chunks” of a cell that are able to pinch off and circulate throughout the body to deliver messenger cargo to other cells. These messengers have become increasingly recognized as crucial mediators of cell-to-cell communication.

In a new study reported in Science Advances, researchers centered at Nagoya University have developed a novel medical device that can efficiently capture these EVs, and potentially use them to screen for cancer.

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EVs are potentially useful as clinical markers. The composition of the molecules contained in an EV may provide a diagnostic signature for certain diseases,” lead author Takao Yasui explains. “The ongoing challenge for physicians in any field is to find a non-invasive diagnostic tool that allows them to monitor their patients on a regular basis–for example, a simple urine test.”

Among the many molecules EVs have been found to harbor are microRNAs, which are short pieces of ribonucleic acid that play diverse roles in normal cellular biology. Critically, the presence of certain microRNAs in urine might serve as a red flag for serious conditions such as bladder and prostate cancer. While this important cargo could therefore theoretically aid physicians in cancer diagnoses, there are still many technological hurdles that need to be overcome. One such hurdle: finding a feasible method to capture EVs in sufficient quantities to analyze them in a routine clinical setting.

The content of EVs in urine is extremely low, at less than 0.01% of the total fluid volume. This is a major barrier to their diagnostic utility,” Yasui notes. “Our solution was to embed zinc oxide nanowires into a specialized polymer to create a material that we believed would be highly efficient at capturing these vesicles. Our findings suggest that the device is indeed quite efficient. We obtained a collection rate of over 99%, surpassing ultracentrifugation as well as other methods that are currently being used in the field.

Source: http://en.nagoya-u.ac.jp/

Nanoscale Memory Cell

Developing a superconducting computer that would perform computations at high speed without heat dissipation has been the goal of several research and development initiatives since the 1950s. Such a computer would require a fraction of the energy current supercomputers consume, and would be many times faster and more powerful. Despite promising advances in this direction over the last 65 years, substantial obstacles remain, including in developing miniaturized low-dissipation memory.

Researchers at the University of Illinois at Urbana-Champaign have developed a new nanoscale memory cell that holds tremendous promise for successful integration with superconducting processors. The new technology, created by Professor of Physics Alexey Bezryadin and graduate student Andrew Murphy, in collaboration with Dmitri Averin, a professor of theoretical physics at State University of New York at Stony Brook, provides stable memory at a smaller size than other proposed memory devices.

The device comprises two superconducting nanowires, attached to two unevenly spaced electrodes that were “written” using electron-beam lithography. The nanowires and electrodes form an asymmetric, closed superconducting loop, called a nanowire ‘SQUID’ (superconducting quantum interference device). The direction of current flowing through the loop, either clockwise or counterclockwise, equates to the “0” or “1” of binary code.

This is very exciting. Such superconducting memory cells can be scaled down in size to the range of few tens of nanometers, and are not subject to the same performance issues as other proposed solutions,” comments Bezryadin.

Murphy adds, “Other efforts to create a scaled-down superconducting memory cell weren’t able to reach the scale we have. A superconducting memory device needs to be cheaper to manufacture than standard memory now, and it needs to be dense, small, and fast.”

Source: https://physics.illinois.edu/

Super Efficient Nanowires shape the future of electronics

A group of researchers at the Basque Excellence Research Center into Polymers (POLYMAT), the University of the Basque Country (UPV/EHU), the University of Barcelona, the Institute of Bioengineering of Barcelona (IBEC), and the University of Aveiro, and led by Aurelio Mateo-Alonso, the Ikerbasque research professor at POLYMAT, have developed a new suite of molecular wires or nanowires that are opening up new horizons in molecular electronics.

The growing demand for increasingly smaller electronic devices is prompting the need to produce circuits whose components are also as small as possible, and this is calling for fresh approaches in their design.

Molecular electronics has sparked great interest because the manufacture of electronic circuits using molecules would entail a reduction in their size. Nanowires are conducting wires on a molecular scale that carry the current inside these circuits. That is why the efficiency of these wires is crucially important.

In fact, one of the main novelties in this new suite of nanowires developed by the group led by Aurelio Mateo lies in their high efficiency, which constitutes a step forward in miniaturizing electronic circuits.
The findings have been published today in the journal Nature Communications.

Source: https://www.ehu.eus/

How To Fine-Tune NanoFabrication

Daniel Packwood, Junior Associate Professor at Kyoto University’s Institute for Integrated Cell-Material Sciences (iCeMS), is improving methods for constructing tiny “nanomaterials” using a “bottom-up” approach called “molecular self-assembly”. Using this method, molecules are chosen according to their ability to spontaneously interact and combine to form shapes with specific functions. In the future, this method may be used to produce tiny wires with diameters 1/100,000th that of a piece of hair, or tiny electrical circuits that can fit on the tip of a needle.

nanofabrication

Molecular self-assembly is a spontaneous process that cannot be controlled directly by laboratory equipment, so it must be controlled indirectly. This is done by carefully choosing the direction of the intermolecular interactions, known as “chemical control”, and carefully choosing the temperature at which these interactions happen, known as “entropic control”. Researchers know that when entropic control is very weak, for example, molecules are under chemical control and assemble in the direction of the free sites available for molecule-to-molecule interaction. On the other hand, self-assembly does not occur when entropic control is much stronger than the chemical control, and the molecules remain randomly dispersed.

Packwood teamed up with colleagues in Japan and the U.S. to develop a computational method that allows them to simulate molecular self-assembly on metal surfaces while separating the effects of chemical and entropic controls. This new computational method makes use of artificial intelligence to simulate how molecules behave when placed on a metal surface. Specifically, a “machine learning” technique is used to analyse a database of intermolecular interactions. This machine learning technique builds a model that encodes the information contained in the database, and in turn this model can predict the outcome of the molecular self-assembly process with high accuracy.

Source: http://www.kyoto-u.ac.jp/

Battery That Could Be Recharged 200,000 Times

Scientists have long sought to use nanowires in batteries. Thousands of times thinner than a human hair, they’re highly conductive and feature a large surface area for the storage and transfer of electrons. However, these filaments are extremely fragile and don’t hold up well to repeated discharging and recharging, or cycling. In a typical lithium-ion battery, they expand and grow brittle, which leads to cracking.

Researchers fron the University of California Irvine (UCI) have solved this problem by coating a gold nanowire in a manganese dioxide shell and encasing the assembly in an electrolyte made of a Plexiglas-like gel. The combination is reliable and resistant to failure.

Mya Le Thai

The study leader, UCI doctoral candidate Mya Le Thai, cycled the testing electrode up to 200,000 times over three months without detecting any loss of capacity or power and without fracturing any nanowires. The findings were published today in the American Chemical Society’s Energy Letters. Hard work combined with serendipity paid off in this case, according to senior author Reginald Penner.

Mya was playing around, and she coated this whole thing with a very thin gel layer and started to cycle it,” said Penner, chair of UCI’s chemistry department. “She discovered that just by using this gel, she could cycle it hundreds of thousands of times without losing any capacity”.

That was crazy,” he added, “because these things typically die in dramatic fashion after 5,000 or 6,000 or 7,000 cycles at most.

Source: https://news.uci.edu/

Solar Fuel Cell For Hydrogen Electric Car

Why not a solar cell that that produces fuel rather than electricity? Researchers at Eindhoven University of Technology (TU/e) (Netherlands) and FOM Foundation today present a very promising prototype of this in the journal Nature Communications. The material gallium phosphide enables their solar cell to produce the clean fuel hydrogen gas from liquid water. Processing the gallium phosphide in the form of very small nanowires is novel and helps to boost the yield by a factor of ten. And does so using ten thousand times less precious material.


hydrogen electric car
The electricity produced by a solar cell can be used to set off chemical reactions. If this generates a fuel, then one speaks of solar fuels – a hugely promising replacement for polluting fuels. One of the possibilities is to split liquid water using the electricity that is generated (electrolysis). Among oxygen, this produces hydrogen gas that can be used as a clean fuel in the chemical industry or combusted in fuel cells – in cars for example – to drive engines.

To connect an existing silicon solar cell to a battery that splits the water may well be an efficient solution now but it is a very expensive one. Many researchers are therefore targeting their search at a semiconductor material that is able to both convert sunlight into an electrical charge and split the water, all in one; a kind of ‘solar fuel cell’. Researchers at TU/e and FOM see their dream candidate in gallium phosphide (GaP), a compound of gallium and phosphide that also serves as the basis for specific colored leds.

GaP
has good electrical properties but the drawback that it cannot easily absorb light when it is a large flat surface as used in GaP solar cells. The researchers have overcome this problem by making a grid of very small GaP nanowires, measuring five hundred nanometers (a millionth of a millimeter) long and ninety nanometers thick. This immediately boosted the yield of hydrogen by a factor of ten to 2.9 percent. A record for GaP cells, even though this is still some way off the fifteen percent achieved by silicon cells coupled to a battery.

According to research leader and TU/e professor Erik Bakkers, it’s not simply about the yield – where there is still a lot of scope for improvement he points out: “For the nanowires we needed ten thousand less precious GaP material than in cells with a flat surface. That makes these kinds of cells potentially a great deal cheaper,” Bakkers says. “In addition, GaP is also able to extract oxygen from the water – so you then actually have a fuel cell in which you can temporarily store your solar energy. In short, for a solar fuels future we cannot ignore gallium phosphide any longer.”

Source: https://www.tue.nl/

How To convert Your Waste Heat Into Electricity

A mathematical model of heat flow through miniature wires could help develop thermoelectric devices that efficiently convert heat — even their own waste heat — into electricity.

Developed at A*STAR (Singapore), the model describes the movement of vibrations called phonons, which are responsible for carrying heat in insulating materials. Phonons typically move in straight lines in nanowires — threads barely a few atoms wide. Previous calculations suggested that if parts of a nanowire contained random arrangements of two different types of atoms, phonons would be stopped in their tracks. In actual alloy nanowires, though, atoms of the same element might cluster together to form short sections composed of the same elements.

phononsPhonons (vibrations) are typically responsible for carrying heat along a nanowire. A*STAR researchers have used a numerical model to calculate the effects of short-range ordering on phonon behaviour.

Now, Zhun-Yong Ong and Gang Zhang of the A*STAR Institute of High Performance Computing in Singapore have calculated the effects of such short-range order on the behavior of phonons1. Their results suggest that heat conduction in a nanowire does not just depend on the relative concentrations of the alloy atoms and the difference in their masses; it also depends on how the atoms are distributed.

Source: http://www.research.a-star.edu.sg/

Stronger Microbes To Clean Up Nuclear Waste

A microbe developed to clean up nuclear waste and patented by a Michigan State University (MSU)researcher has just been improved. In earlier research, Gemma Reguera, MSU microbiologist, identified that Geobacter bacteria’s tiny conductive hair-like appendages, or pili, did the yeoman’s share of remediation. By increasing the strength of the pili nanowires, she improved their ability to clean up uranium and other toxic wastes. In new research, published in the current issue of Applied and Environmental Microbiology, Reguera has added an additional layer of armor to her enhanced microbes. The microbes also use the pili to stick to each other and grow a film on just about any surface, similar to the bacterial film that forms on teeth. The Geobacter biofilm, encased by a network of nanowires and slime, gives the bacteria a shield and increases their ability to neutralize even more uranium. The improvement also allows the bacteria to survive longer even when exposed to higher concentrations of the radioactive material. Geobacter immobilizing uranium can be described as nature’s version of electroplating. The beefed-up microbes engulf the uranium and turn it into a mineral, preventing the toxic material from leaching into groundwater.
nucelar waste
The results surpassed our most optimistic predictions,” Reguera said. “Even thin biofilms immobilized uranium like sponges. They reduced it to a mineral, all while not suffering any damage to themselves, for prolonged periods of time.
Source: http://msutoday.msu.edu/

Copper, The Cheap Material For Solar Energy

Copper adorns the Statue of Liberty, makes sturdy, affordable wiring, and helps our bodies absorb iron. Now, researchers at Duke University would like to use copper to transform sunlight and water into a chemical fuel. Converting solar energy into storable fuel remains one of the greatest challenges of modern chemistry. One of the ways chemists have tried to capture the power of the sun is through water splitting, in which the atoms of H2O are broken apart so the hydrogen may be collected and used as fuel. Plants do this naturally through photosynthesis, and for half a century, scientists have tried to recreate that process by tinkering with chemical catalysts jumpstarted by sunlight. Indium tin oxide (ITO) is one material they’ve commonly tried to use. Researchers prefer it for its transparency — which allows sunlight to pass through and trigger the water-splitting reactions — and its ability to conduct electricity. But ITO is far from an ideal material.
Copper Nanowire

Indium is not very abundant,” said Ben Wiley, assistant professor of chemistry at Duke University. “It is similar in abundance to silver in the earth’s crust.” As a result, solar fuel cells using ITO will likely remain expensive and uncompetitive with conventional energy sources like coal and natural gas“, he said. Copper is 1000 times more plentiful and 100 times less expensive than indium. Copper nanowire catalysts also cost less to produce than their ITO counterparts because they can be “printed” on pieces of glass or plastic in a liquid ink form, using a machine that functions much like a printing press. ITO production, by contrast, requires large, sequential chambers of pumps and vacuums that deposit a thin layer of indium atoms at a far slower rate.

Source: http://today.duke.edu/

Viruses Boost Electric Car Batteries

MIT researchers find a way to boost lithium-air battery performance, with the help of modified viruses. Lithium-air batteries have become a hot research area in recent years: They hold the promise of drastically increasing power per battery weight, which could lead, for example, to electric cars with a much greater driving range. But bringing that promise to reality has faced a number of challenges, including the need to develop better, more durable materials for the batteries’ electrodes and improving the number of charging-discharging cycles the batteries can withstand. Now, MIT researchers have found that adding genetically modified viruses to the production of nanowires — wires that are about the width of a red blood cell, and which can serve as one of a battery’s electrodes — could help solve some of these problems.
viruses for electric batteries
Professor Angela Belcher, the W.M. Keck Professor of Energy and a member of MIT’s Koch Institute for Integrative Cancer Research, explains that this process of biosynthesis is “really similar to how an abalone grows its shell”. Belcher emphasizes that this is early-stage research, and much more work is needed to produce a lithium-air battery that’s viable for commercial production. This work only looked at the production of one component, the cathode; other essential parts, including the electrolyte — the ion conductor that lithium ions traverse from one of the battery’s electrodes to the other — require further research to find reliable, durable materials. Also, while this material was successfully tested through 50 cycles of charging and discharging, for practical use a battery must be capable of withstanding thousands of these cycles.
The findings have been published in the journal Nature Communications, co-authored by graduate student Dahyun Oh, professors Angela Belcher and Yang Shao-Horn, and three others

Source: http://web.mit.edu/

Solar Power : Quantum Dots Versus Nanowires

A trio of researchers at North Dakota State University, Fargo, and the University of South Dakota have turned to computer modeling to help decide which of two competing materials should get its day in the sun as the nanoscale energy-harvesting technology of future solar panelsquantum dots or nanowires. Andrei Kryjevski and his colleagues, Dimitri Kilin and Svetlana Kilina, report in AIP Publishing’s Journal of Renewable and Sustainable Energy that they used computational chemistry models to predict the electronic and optical properties of three types of nanoscale (billionth of a meter) silicon structures with a potential application for solar energy collection: a quantum dot, one-dimensional chains of quantum dots and a nanowire. The ability to absorb light is substantially enhanced in nanomaterials compared to those used in conventional semiconductors. Determining which form — quantum dots or nanowire — maximizes this advantage was the goal of the numerical experiment conducted by the three researchers.nanowires
Amorphous Silicon nanowire (yellow network) facilitates harvesting of solar energy in the form of a photon (wavy line). In the process of light absorption a pair of mobile charge carriers is created (red clouds depict an electron smeared in space, while the blue clouds visualize the so-called hole which is a positively charged carrier). The energy of their directed motion is then transformed into electricity.
We used Density Functional Theory, a computational approach that allows us to predict electronic and optical properties that reflect how well the nanoparticles can absorb light, and how that effectiveness is affected by the interaction between quantum dots and the disorder in their structures,” Kryjevski said. “This way, we can predict how quantum dots, quantum dot chains and nanowires will behave in real life even before they are synthesized and their working properties experimentally checked.
Source: http://jrse.aip.org/
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http://www.eurekalert.org/

Artificial Skin For Robots Like Human Skin

Researchers from the Georgia Institute of Technology have fabricated arrays of piezotronic transistors capable of converting mechanical motion directly into electronic controlling signals. The arrays could help give robots a more adaptive sense of touch. Mimicking the sense of touch electronically has been challenging, and is now done by measuring changes in resistance prompted by mechanical touch. The devices developed By Georgia Tech scientists rely on a different physical phenomenon – tiny polarization charges formed when piezoelectric materials such as zinc oxide are moved or placed under strain. In the piezotronic transistors, the piezoelectric charges control the flow of current through the wires just as gate voltages do in conventional three-terminal transistors.

robots

Any mechanical motion, such as the movement of arms or the fingers of a robot, could be translated to control signals,” explained Zhong Lin Wang, a Regents’ professor and Hightower Chair in the School of Materials Science and Engineering at the Georgia Institute of Technology. “This could make artificial skin smarter and more like the human skin. It would allow the skin to feel activity on the surface.
Source: http://www.gatech.edu/