New 2D Transistor Material Made Using Precision Lasers

(Above: Top, 2H-MoTe2 Bottom, 1T’-MoTe2)

-  A New Technique for Making 2D Transistor from dual-phase TMD Crystal -

(August 7, 2015)  Molybdenum ditelluride (MoTe2)  is a crystalline compound that if pure enough can be used as a transistor.  Its molecular structure is an atomic sandwich made up of one molybdenum atom for every two tellurium atoms.  It was first made in the 1960’s via several different fabrication methods, but until last year it had never been made in a pure enough form to be suitable for electronics.

Last year a multi-discipline research team led by South Korea’s Institute for Basic Science (IBS) Center for Integrated Nanostructure Physics at Sungkyunkwan University (SKKU) director Young Hee Lee devised a fabrication method for the creation of pure MoTe2.  Not only did they succeed in making MoTe2 in pure form, they were able to make two types of it — a semiconducting variety called 2H-MoTe2 (2H because of its hexagonal shape) and a metallic variety called 1T'-MoTe2 (1T’ because it has an octahedral shape) —  which are both stable at room temperature.

(Above: A simulation of the process of converting the  2H-MoTe2

into 1T'-MoTe2 with laser-irradiation)

Making MoTe2 in a pure form was very difficult and it was seen by some as a black sheep of the transition metal dichalcogenides (TMD) family and purposefully ignored.  TMDs are molecules that can be made exceedingly thin, only several atomic layers, and have an electrical property called a band gap, which makes them ideal for making electrical components, especially transistors. 

A TMD crystal follows an MX2 format: there is one transition metal, represented by M (M can be Tungsten, Molybdenum, etc.) and two chalcogenides, the X2 (Sulfur, Selenium, or Tellurium).  These atoms form a thin, molecular sandwich with the one metal and two chalcogenides, and depending on their fabrication method can exist in several slightly different shaped atomic arrangements.

(Above: the 2H-MoTe2 and 1T'-MoTe2 transition line and metal electrodes

attached to the 1T'-MoTe2)

The overwhelming majority of microchips that exist in electronics now are made from silicon, and they work extremely well.  However, as devices get smaller there is an increasing demand to shrink the size of the logic chips that make those devices work.  As the chips approach single or several atom thickness, (commonly referred to as 2-dimensional), silicon no longer works as well as it does in a larger, 3-dimensional (3D) scale.  As the scale approaches 2 dimensions (2D), the band gap of silicon changes (higher band gap than that of its 3D form) and the contact points with metal connections on silicon are no longer smooth enough to be used efficiently in electrical circuits.

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TSRI Chemists Report Nicotine-Chomping Bacteria May Hold Key to Anti-Smoking Therapy

Scripps Research Institute Professor Kim Janda (center), Graduate Student

Song Xue (left) and Research Associate Joel Schlosburg were authors of the new paper

(August 7, 2015) A new study from scientists at The Scripps Research Institute (TSRI) explores a bacterial enzyme that might be used as a drug candidate to help people quit smoking. The research shows that this enzyme can be recreated in lab settings and possesses a number of promising characteristics for drug development.

“Our research is in the early phase of drug development process, but the study tells us the enzyme has the right properties to eventually become a successful therapeutic,” said Kim Janda, the Ely R. Callaway Jr. Professor of Chemistry and member of the Skaggs Institute for Chemical Biology at TSRI.

The new research, published online ahead of print on August 6 in the Journal of the American Chemical Society, offers a possible alternative to current smoking cessation aids, which are shown to fail in at least 80 to 90 percent of smokers. The idea behind an enzyme therapy would be to seek out and destroy nicotine before it reaches the brain—depriving a person of the “reward” of nicotine that can trigger relapse into smoking.

For more than 30 years, Janda and his colleagues have struggled to create such an enzyme in the lab, but they recently ran across a potential enzyme found in nature—NicA2 from the bacteria known as Pseudomonas putida. It turns out this bacterium—originally isolated from soil in a tobacco field—consumes nicotine as its sole source of carbon and nitrogen.

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WATCHme - Cute Apple Watch charging stand

(August 6, 2015) WATCHme is a charging stand that will turn your smartwatch into a cute little monster.

WatchMe has been selectively bred for months for various behaviors, cord management capabilities, and physical attributes.

It has no external ears and has very poor eyesight, however, it can be greatly improved by peculiar spectacles called « SmartWatch ».

The domestic WatchMe performs many roles for people, such as decorating a bedside, companionship, and charging a wearable technology.

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COZZEE SPECIAL COFFEE

COZZEE Is a social good company that sells specialty coffee online and always you you impact the  World by giving the profits from your purchase to a cause that you choose.

You buy some of the best coffee around. You choose one of 7 causes you are most passionate about. We ship your freshly roasted coffee straight to your door. Then we give 100% of the profits of your purchase to our nonprofit partner leading a project in that cause area.

It’s as simple as that

Making a difference is the heart and soul of Cozzee. That’s why we give 100% of our profits away to fight 7 of the most urgent causes affecting our world today. We partner with 7 nonprofits, one for each cause area, every 7 weeks and raise funds for a specific project in each organization.

It’s as simple as that

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Flexible dielectric polymer can stand the heat

Researcher holds flexible dielectric polymer. Insert shows boron nitride nanosheets.

Image: Qing Wang/Penn State

(August 6, 2015)  Easily manufactured, low cost, lightweight, flexible dielectric polymers that can operate at high temperatures may be the solution to energy storage and power conversion in electric vehicles and other high temperature applications, according to a team of Penn State engineers.

"Ceramics are usually the choice for energy storage dielectrics for high temperature applications, but they are heavy, weight is a consideration and they are often also brittle," said Qing Wang, professor of materials science and engineering, Penn State. "Polymers have a low working temperature and so you need to add a cooling system, increasing the volume so system efficiency decreases and so does reliability."

Dielectrics are materials that do not conduct electricity, but when exposed to an electric field, store electricity. They can release energy very quickly to satisfy engine start-ups or to convert the direct current in batteries to the alternating current needed to drive motors.

Applications like hybrid and electric vehicles, aerospace power electronics and underground gas and oil exploration equipment require materials to withstand high temperatures. The researchers developed a cross-linked polymer nanocomposite containing boron nitride nanosheets. This material has high-voltage capacity for energy storage at elevated temperatures and can also be photo patterned and is flexible. The researchers report their results in a recent issue of Nature.

This boron nitride polymer composite can withstand temperatures of more than 480 degrees Fahrenheit under the application of high voltages. The material is easily manufactured by mixing the polymer and the nanosheets and then curing the polymer either with heat or light to create crosslinks. Because the nanosheets are tiny -- about 2 nanometers in thickness and 400 nanometers in lateral size, the material remains flexible, but the combination provides unique dielectric properties, which include higher voltage capability, heat resistance and bendability.

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Protective shells may boost silicon lithium-ion batteries

Lithium ions react with silicon to form a new compound, which causes

the electrode to expand. Researchers found that flouroethylene carbonate molecules

produce a rubber-like protective layer that can accommodate the electrode expansion.

Infographic by Sana Sandler/Sarah Schlieder

(August 6, 2015)  Imagine a cell a phone that charges in less than an hour and lasts for three to four days or an electric car that runs for hundreds of miles before needing to be plugged in.

Researchers at the U.S. Department of Energy’s Argonne National Laboratory are working to make this dream a reality by developing lithium-ion batteries containing silicon-based materials. The most commonly used commercial lithium-ion batteries are graphite-based, but scientists are becoming increasingly interested in silicon because it can store roughly 10 times more lithium than graphite.

“When we talk about batteries, we talk in terms of the amount of energy that can be stored,” said Daniel Abraham, materials scientist in Argonne’s Chemical Sciences and Engineering Division. “Silicon-based batteries could double or even triple the energy stored in conventional batteries, which would greatly benefit the consumer electronics market and the automotive industry.”

There’s just one problem: current batteries based on silicon materials don’t last long.

The problem lies in the battery’s chemistry. The electrolyte inside the battery transports lithium ions back and forth between positive and negative electrodes as the battery charges and discharges. The positive electrode contains a lithium-bearing compound, while the negative electrode contains materials such as graphite or silicon.

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Searching for Life in the Alpha Centauri System

The polarized light reflected from the leaf contains a footprint of the leaf's biopigments.

These biosignatures can be detected with a polarization filter, shown here

as a pair of sunglasses. Illustration: Svetlana Berdyugina

A new technique enables scientists to search for traces of life on exoplanets in reflected light

(August 6, 2015)  A new approach to searching for life on other planets: An international team has discovered that biopigments of plants, so-called biological photosynthetic pigments, leave behind unique traces in the light they reflect. Prof. Dr. Svetlana Berdyugina from the Institute of Physics of the University of Freiburg and the Freiburg Kiepenheuer Institute for Solar Physics studied these biosignatures together with researchers from the University of Hawaiʻi at Mānoa, USA, and the University of Aarhus, Denmark, with the help of polarization filters: If biopigments were present as a sign of life on a planet, they would leave behind a detectable polarized signature in the reflected light. The scientists have now published their findings in the International Journal of Astrobiology.

  

Figure 1: A green leaf absorbs almost all red, green and blue light (RGB), but it reflects

and transmits infrared light (shown in grey). The reflected infrared light is only weakly polarized

due to the reflection of a healthy leaf, but the reflected RGB light is strongly polarized due to

biopigments. Measuring the amount of polarized light at different colors reveals the signature

of the leaf biopigments. Green sand reflects and polarizes sunlight almost equally in all

wavelengths, which distinguishes it from a leaf that is a similar color.

Similarly, yellow plants are different from yellow sand, etc. (Credit: S. Berdyugina)

Photosynthetic pigments are plant substances that absorb and reflect particular wavelengths of visible light, making them appear in color in the reflected wave ranges. Biopigments are what gives plants, algae, bacteria, and human skin and eyes their colorful appearance. Chlorophyll pigments in plant leaves, for instance, absorb blue to red light but reflect a small part of green in the visible spectrum and thus appear green. An exception is infrared light: half of it is reflected and the other half passes through the leaf. Carotenoids absorb blue and red light but reflect yellow light and are thus typically red, orange, or yellow in color.

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PLATEAU

Design by Søren Rose Studio, 2015

(August 6, 2015)  NEW! To be launched in Milan April 2015 (Available from August 2015).

The PLATEAU table adds a beautiful and timeless side table with an understated personality to the collection.  By combining a solid wooden top with an elegant brushed stainless steel base, the aesthetics of Søren Rose Studio and dk3 unites in celebrating simple design and paying tribute to simplicity and honest materials.

PLATEAU is developed with inspiration from a tree trunk and we created a side table with the ability to blend into any setting and room where aesthetics and quality are paramount.

Material: Solid walnut or oak

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Safe motorcycle helmets – made of carrot fibers?

Detailed life cycle assessments for industrial products of the future

August 6, 2015)  Crackpot idea or recipe for success? This is a question entrepreneurs often face. Is it worth converting the production process to a new, ecologically better material? Empa has developed an analysis method that enables companies to simulate possible scenarios – and therefore avoid bad investments. Here’s an example: Nanofibers made of carrot waste from the production of carrot juice, which can be used to reinforce synthetic parts.

Motorcycle helmets consist of fiber-reinforced synthetic material. Instead of glass fibers, a biological alternative is now also possible: plant fibers from the production of carrot juice. Empa researchers are now able to analyze whether this kind of production makes sense from an ecological and economical perspective – before money is actually invested in production plants. 

All over the world, research is being conducted into biodegradable and recyclable synthetics. However, fiber-reinforced components remain problematic – if glass or carbon fibers are used. Within the scope of an EU research project, the Scottish company Cellucomp Limited has now developed a method to obtain nanofibers from carrot waste. These fibers would be both cost-effective and biodegradable. However, is the method, which works in the lab, also marketable on a large scale? 

An MPAS (multi-perspective application selection) method developed at Empa helps identify the industrial sectors where new materials might be useful from a technical and economical perspective. At the same time, MPAS also considers the ecological aspect of these new materials. The result for our example: Nanofibers made of carrot waste might be used in the production of motorcycle helmets or side walls for motorhomes in the future.

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Non-magnetic metals turned into magnets

Maurice Savage/Alamy

Copper: not a magnetic metal, unless it is combined in thin films with organic molecules.

Thin films of copper and manganese made to behave like iron, cobalt or nickel.

(August 6, 2015)  Two common metals that are not magnetic — copper and manganese — can be transformed into magnets: a surprising effect that involves combining thin films of the metals with carbon-based organic molecules.

The magnetism is weak and fades away after a few days, but the discovery could lead to new kinds of hybrid metal–organic magnets that might be useful in applications such as medical imaging, says Oscar Cespedes of the University of Leeds, UK, who led the work1 reported on 5 August in Nature.

Permanent magnets, such as iron bars, gain their pulling power from the spins of the electrons inside them. This quantum-mechanical property means that each electron generates its own magnetic field. Most electrons couple their spins so as to cancel each other out, producing no overall effect, but some ‘unpaired’ electrons will align with an external magnetic field, and will stay that way when that field is removed. The cumulative effect of these tiny aligned magnetic fields makes the metals iron, cobalt and nickel magnetic at room temperature.

Cespedes and his colleagues made copper and manganese behave this way, too. They laid down films of the metals on layers of buckyballs, which are cage-like molecules made up of 60 carbon atoms, chosen because they are particularly good at stripping electrons from the metal films. This made the films partially magnetic, across a layer a few nanometres thick next to the buckyballs. When an external field was applied and then removed, some 10% of the induced magnetic field remained, producing a weak magnet.

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On the way towards the "green cell factory"

Cyanobacterial enzyme expression of enantioselective enzymes

is a sustainable source of biocatalysts for the chemical industry.

Bartsch et al. Microbial Cell Factories 2015 14:53   doi:10.1186/s12934-015-0233-5

Cyanobacteria can manufacture biocatalysts for the industry

Sustainable production: photosynthesis as energy source

(August 6, 2015)  Using photosynthetically active microorganisms, researchers at the Ruhr-Universität Bochum (RUB) have succeeded in manufacturing several biocatalysts suitable for industrial application: a crucial step towards sustainable chemical processes, according to Dr Marc Nowaczyk from the Chair for Plant Biochemistry and Jun.-Prof Dr Robert Kourist, Junior Research Group Microbial Biochemistry.

Sustainable manufacture of enzymes for the industry

Seeing as our planet's fossil resources are limited, researchers are looking for new methods for the production of certain substances, which are not dependent on mineral oil. Photoautotrophic organisms, which gain their energy from light, could be a key to success. The preparation of enzymes allows industrial applications as detergents and for the manufacture of food The only source materials that organisms such as cyanobacteria require for enzyme synthesis are light, water, nutrient salts and CO2. Complex carbon sources such as sugar are not needed, making the approach a sustainable and renewable alternative to the use of agricultural products for cultivation. The researchers from RUB are attempting to develop such "green cell factories".

 Plasmids for the site-directed genome integration of genes by homologous recombination.

Bartsch et al. Microbial Cell Factories 2015 14:53   doi:10.1186/s12934-015-0233-5

Feasibility study successful: cyanobacteria compatible with enzyme production

Using cyanobacteria, the researchers from Bochum manufactured enzymes which, in turn, can be used for producing valuable pharmaceutical substances. For this purpose, they planted genes for enzyme synthesis into the microorganisms. "A particularly important observation was that cell components of cyanobacteria do not interfere with the catalytic activity," Robert Kourist sums up the results of the study. "Using photosynthesis for the production of industrial enzymes from carbon dioxide and water is a novel and environmentally friendly approach."

Process generates pure products

Many catalytic processes result in not only the desired product, but also in a number of by-products, which have to be painstakingly filtered out. Chemical reactions often generate two substances whose chemical structures behave like image and mirror image, so called enantiomers. Using the cyanobacterial, the Bochum researchers have succeeded in generating primarily one structure – an important requirement for pharmaceutical application. They published the results in the journal "Microbial Cell Factories".

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journal reference (Open Access)  >>

“Yolks” and “shells” improve rechargeable batteries

A new "yolk-and-shell" nanoparticle could boost the capacity and power of lithium-ion batteries.

The gray sphere at center represents an aluminum nanoparticle, forming the "yolk."

The outer light-blue layer represents a solid shell of titanium dioxide, and the space

in between the yolk and shell allows the yolk to expand and contract without damaging the shell.

In the background is an actual scanning electron microscope image of a collection of

these yolk-shell nanoparticles. Image: Christine Daniloff/MIT

Aluminum could give a big boost to capacity and power of lithium-ion batteries.

(August 6, 2015)  One big problem faced by electrodes in rechargeable batteries, as they go through repeated cycles of charging and discharging, is that they must expand and shrink during each cycle — sometimes doubling in volume, and then shrinking back. This can lead to repeated shedding and reformation of its “skin” layer that consumes lithium irreversibly, degrading the battery’s performance over time.

Now a team of researchers at MIT and Tsinghua University in China has found a novel way around that problem: creating an electrode made of nanoparticles with a solid shell, and a “yolk” inside that can change size again and again without affecting the shell. The innovation could drastically improve cycle life, the team says, and provide a dramatic boost in the battery’s capacity and power.

The new findings, which use aluminum as the key material for the lithium-ion battery’s negative electrode, or anode, are reported in the journal Nature Communications, in a paper by MIT professor Ju Li and six others. The use of nanoparticles with an aluminum yolk and a titanium dioxide shell has proven to be “the high-rate champion among high-capacity anodes,” the team reports.

Most present lithium-ion batteries — the most widely used form of rechargeable batteries — use anodes made of graphite, a form of carbon. Graphite has a charge storage capacity of 0.35 ampere-hours per gram (Ah/g); for many years, researchers have explored other options that would provide greater energy storage for a given weight. Lithium metal, for example, can store about 10 times as much energy per gram, but is extremely dangerous, capable of short-circuiting or even catching fire. Silicon and tin have very high capacity, but the capacity drops at high charging and discharging rates.

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Two Spin Liquids Square Off in an Iron-Based Superconductor

Model electron spin maps of the iron-tellurium-sulfur material. The left-hand column, a-c,

shows three models of electron spin correlations, with the red and green colors

of the peaks and corresponding planar projections below each model representing

oppositely oriented spins. The images on the right, d-f, show the resulting neutron

scattering patterns for each case. Starting at a, which represents the dominant

correlations at high temperature, notice how the spins form alternating squares

like a checkerboard in the planar projection, and how the "square dance partners"

of the pattern change to diagonals in (b), which occurs on cooling to low temperature,

and finally to alternating stripes stipulated to exist in a good superconductor (c).

Changes in short-range, transient order in competing liquid-like phases precede onset of superconductivity

(August 6, 2015)  Despite a quarter-century of research since the discovery of the first high-temperature superconductors, scientists still don't have a clear picture of how these materials are able to conduct electricity with no energy loss. Studies to date have focused on finding long-range electronic and magnetic order in the materials, such as patterns of electron spins, based on the belief that this order underlies superconductivity. But a new study published online the week of August 3, 2015, in the Proceedings of the National Academy of Sciences is challenging this notion.

The study, conducted by researchers from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and Oak Ridge National Laboratory (ORNL), describes how an iron-telluride material related to a family of high-temperature superconductors develops superconductivity with no long-range electronic or magnetic order when "doped" with a small amount of sulfur. In fact, the material displays a liquid-like magnetic state consisting of two coexisting and competing disordered magnetic phases, which appears to precede—and may be linked to—its superconducting behavior.

Left to right: Brookhaven physicists Igor Zaliznyak, Alexei Tsvelik, and Cedomir Petrovic

with models representing electron spin correlations in an iron-based superconductor.

"Our results challenge a number of widely accepted paradigms into how unconventional superconductors work," said the study's lead researcher, Brookhaven physicist Igor Zaliznyak. "I believe that we have uncovered an important clue to the nature of magnetism and its connections to superconductivity in the iron-based superconductors."

This advance could open up a new avenue for exploring the emergence of a property with great potential for widespread use. Conventional superconductors, which must be chilled to extremely low temperatures to operate, already play a key role in many modern technologies, from medical magnetic resonance imaging (MRI) to maglev trains. New clues about the function of unconventional superconductors, which do not need to be super-cooled, could lead to many more technologies, including, potentially, zero-energy-loss power transmission lines and other important energy applications. Indeed, other materials based upon a similar structure as the material studied here can operate as superconductors at these "warmer" temperatures, so understanding the physics of this close relative has many important implications.

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River Buries Permafrost Carbon at Sea

WHOI Associate Scientist Valier Galy lowers a sampling device into the Mackenzie River.

Chemical analysis of the collected samples revealed that the river’s transport of organic carbon creates

a carbon sink, burying CO2 in Arctic Ocean sediments without releasing it into the atmosphere.

(Photo by Robert Hilton, Durham University)

New study traces the fate of carbon stored in thawing Arctic soils

(August 6, 2015)  As temperatures rise, some of the organic carbon stored in Arctic permafrost meets an unexpected fate—burial at sea. As many as 2.2 million metric tons of organic carbon per year are swept along by a single river system into Arctic Ocean sediment, according to a new study an international team of researchers published today in Nature. This process locks away carbon dioxide (CO2) - a greenhouse gas - and helps stabilize the earth’s CO2 levels over time, and it may help scientists better predict how the natural carbon cycle will interplay with the surge of CO2 emissions due to human activities.

“The erosion of permafrost carbon is very significant,” says Woods Hole Oceanographic Institution (WHOI) Associate Scientist Valier Galy, a co-author of the study. “Over thousands of years, this process is locking CO2 away from the atmosphere in a way that amounts to fairly large carbon stocks. If we can understand how this process works, we can predict how it will respond as the climate changes.”

Northern Canada’s Mackenzie River is the largest river flowing into the Arctic Ocean from North America—and the dominant source of biosphere-derived organic carbon in Arctic Ocean sediments, according to a new study. (Photo by Robert Hilton, Durham University)

Permafrost—frozen ground found in the Arctic and in some alpine regions—is known to hold billions of tons of organic material. Amid concerns about rising Arctic temperatures and their impact on permafrost, many researchers have directed their efforts to studying the permafrost carbon cycle—the processes through which carbon circulates between the atmosphere, the soil and plants (the biosphere), and the sea. Yet how this cycle works and how it responds to the warming, changing climate remains poorly understood.

Galy and his colleagues from Durham University, the Institut de Physique du Globe de Paris, the NERC Radiocarbon Facility, Stockholm University, and the Universite Paris-Sud set out to characterize the carbon cycle in one particular piece of the Arctic landscape—northern Canada’s Mackenzie River, the largest river flowing into the Arctic Ocean from North America and that ocean’s greatest source of sediment. The researchers hypothesized that the Mackenzie’s muddy water might erode soils along its path, some from places where permafrost is melting, and wash that biosphere-derived material and the organic carbon within it into the ocean, preventing the degradation of organic carbon and associated release of CO2 into the atmosphere.

The researchers collected samples (denoted by circles) at three locations along the Mackenzie River—the river delta (black), Tsiigehtchic (grey), and Norman Wells (white)—along with its major tributaries, the Liard River (red diamond), the Arctic Red River (light blue square), and the Peel River (dark blue square). They compared the chemical composition of these samples with those obtained from the sediment core MTW01 in the Arctic Ocean’s Mackenzie trough (triangle).  a, The river’s major channels (black lines) are overlain on a digital elevation model that shows sediment catchment areas and flow accumulation and flow direction with dotted lines. b, A map shows the status of permafrost in the upstream areas of the Mackenzie River basin. c, White rectangles show the sample locations near the Mackenzie River delta overlain on satellite imagery of the basin.

(Illustration courtesy of Hilton, et al)

The researchers collected samples at various depths and locations along the river system, lowering a specially-designed device to take samples of the water and suspended sediments carried by the river. To take into consideration the river’s seasonal variation—its flow increases sharply during the spring, when warm temperatures melt the snowpack and raise water levels, and drops during the frozen winter months—they sampled it during different seasons across three years starting in 2009.

Then the researchers sifted through the samples to isolate the carbon they contained. They used the presence of one specific isotope of carbon that decays over time, carbon-14, to determine how old the carbon was. This was important because it revealed the carbon’s origin– rock or biosphere.

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Sandcastles Inspire New Nanoparticle Binding Technique

NC State researchers develop a technique to assemble nanoparticles into filaments (left) in liquid.

The filaments can be broken (middle) and then re-assembled (right).

Image courtesy of Bhuvnesh Bharti.

(August 6, 2015)  If you want to form very flexible chains of nanoparticles in liquid in order to build tiny robots with flexible joints or make magnetically self-healing gels, you need to revert to childhood and think about sandcastles.

In a paper published this week in Nature Materials, researchers from North Carolina State University and the University of North Carolina-Chapel Hill show that magnetic nanoparticles encased in oily liquid shells can bind together in water, much like sand particles mixed with the right amount of water can form sandcastles.

“Because oil and water don’t mix, the oil wets the particles and creates capillary bridges between them so that the particles stick together on contact,” said Orlin Velev, INVISTA Professor of Chemical and Biomolecular Engineering at NC State and the corresponding author of the paper.

“We then add a magnetic field to arrange the nanoparticle chains and provide directionality,” said Bhuvnesh Bharti, research assistant professor of chemical and biomolecular engineering at NC State and first author of the paper.

Chilling the oil is like drying the sandcastle. Reducing the temperature from 45 degrees Celsius to 15 degrees Celsius freezes the oil and makes the bridges fragile, leading to breaking and fragmentation of the nanoparticle chains. Yet the broken nanoparticles chains will re-form if the temperature is raised, the oil liquefies and an external magnetic field is applied to the particles.

“In other words, this material is temperature responsive, and these soft and flexible structures can be pulled apart and rearranged,” Velev said. “And there are no other chemicals necessary.”

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Concertina Design Paper Chair/Sofa

Inspired by the flexible accordion, designers have created these breathable furniture that can not only use as decorations, but also furniture. This paper sofa utilizes recyclable kraft paper with a concertina design to expand into a sturdy matrix to hold things. These materials are waterproof and the stretching ratio can reach 1:50. It can also fold back into a two dimensional form which is ideal for those that are short in space or that tend to move around a lot. Available in many sizes, the small size can use as single chair, the bigger size, sofa as well.

source >>

Could Body Posture During Sleep Affect How Your Brain Clears Waste?

The brain’s glymphatic pathway clears harmful wastes, especially during sleep.

This lateral position could prove to be the best position for the brain-waste clearance process.

Stony Brook researchers publish experimental findings in the Journal of Neuroscience that show the lateral position more efficiently rids the brain of solutes that may contribute to disease

(August 5, 2015)  Sleeping in the lateral, or side position, as compared to sleeping on one’s back or stomach, may more effectively remove brain waste and prove to be an important practice to help reduce the chances of developing Alzheimer’s, Parkinson’s and other neurological diseases, according to researchers at Stony Brook University.

By using dynamic contrast magnetic resonance imaging (MRI) to image the brain’s glymphatic pathway, a complex system that clears wastes and other harmful chemical solutes from the brain, Stony Brook University researchers Hedok Lee, PhD, Helene Benveniste, MD, PhD, and colleagues, discovered that a lateral sleeping position is the best position to most efficiently remove waste from the brain. In humans and many animals the lateral sleeping position is the most common one. The buildup of brain waste chemicals may contribute to the development of Alzheimer’s disease and other neurological conditions. Their finding is published in the Journal of Neuroscience.

Helene Benveniste, MD, PhD, and Hedok Lee, PhD,

analyzed the glymphatic pathways of rodent models to assess

how body posture affects the clearance of brain waste. 

Dr. Benveniste, Principal Investigator and a Professor in the Departments of Anesthesiology and Radiology at Stony Brook University School of Medicine, has used dynamic contrast MRI for several years to examine the glymphatic pathway in rodent models. The method enables researchers to identify and define the glymphatic pathway, where cerebrospinal fluid (CSF) filters through the brain and exchanges with interstitial fluid (ISF) to clear waste, similar to the way the body’s lymphatic system clears waste from organs. It is during sleep that the glymphatic pathway is most efficient. Brain waste includes amyloid β (amyloid) and tau proteins, chemicals that negatively affect brain processes if they build up.

A study by Stony Brook University researchers suggests that sleeping on one’s side,

as opposed to other positions such as on one’s back or stomach, may more effectively

remove brain waste, a contributor to the development of neurological disorders.

In the paper, “The Effect of Body Posture on Brain Glymphatic Transport,” Dr. Benveniste and colleagues used a dynamic contrast MRI method along with kinetic modeling to quantify the CSF-ISF exchange rates in anesthetized rodents’ brains in three positions – lateral (side), prone (down), and supine (up).

“The analysis showed us consistently that glymphatic transport was most efficient in the lateral position when compared to the supine or prone positions,” said Dr. Benveniste. “Because of this finding, we propose that the body posture and sleep quality should be considered when standardizing future diagnostic imaging procedures to assess CSF-ISF transport in humans and therefore the assessment of the clearance of damaging brain proteins that may contribute to or cause brain diseases.”

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Lost lithium destroyed by ancient stars

‘Sunbirth’: a painting inspired by the formation of a star. Credit: Arthure Billard.

(August 5, 2015)  Lithium, the lightest metal, used in batteries and mood-stabilising drugs, is rarer than it should be. Models of the period after the Big Bang explain how it, hydrogen and helium were synthesised in nuclear reactions, before the universe cooled enough for the stars and planets that we see today to come into being. Astronomers though think that about three times as much lithium was produced in that earliest epoch than remains today in the oldest stars in the galaxy, and the difference has proved hard to explain.

Now a group of scientists, led by Xiaoting Fu of the International School for Advanced Studies in Trieste, Italy, think they have the answer to this so-called ‘lithium problem’: it was destroyed and re-accumulated by these stars shortly after they were born. The team publish their work in Monthly Notices of the Royal Astronomical Society.

In the past astronomers have speculated on what might be responsible for the lithium deficit. Ideas included as yet unknown aspects of particle physics, nuclear physics or even new models of cosmology.

Fu’s team instead looked at how much lithium there would have been when a particular subset of the first long-lived stars formed, just a few hundred million years after the Big Bang. These are still around today, so provide astronomers with some insight into the history of the universe and how its composition has changed.

An illustration of a protostar (a pre-main sequence star) surrounded by a disk of gas and dust.

Credit: NASA/CXC/M.Weiss.

The stars have between 50 and 85% of the mass of the Sun, have lives that are significantly longer, and are thought to remain stable on the so-called ‘main sequence’ for between 15 and 30 billion years. They are poor in most ‘metals’, which in astronomy means every element heavier than helium. The scientists modelled the way that these stars process lithium, starting with the early part of their lives when they are still contracting and heating up under the influence of gravity.

In that ‘pre-main sequence’ phase, the new model suggests that there is more mixing in the different layers of these objects. To put this in context, stars have a hot core, where nuclear fusion is converting hydrogen to helium, a cooler outer layer where convection cycles material from above the core to the surface and down again, and a surface where electromagnetic radiation (including light and heat) escapes into space.

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Flowers Can Endanger Bees

Photo shows a bumblebee (Bombus melanopygus) in flight towards a pansy flower.

Photo credit: Kathy Keatley Garvey, UC Davis.

Study by UC Riverside entomologist and colleagues shows flowers serve as parasite-dispersing hubs

(August 5, 2015)  Despite their beauty, flowers can pose a grave danger to bees by providing a platform of parasites to visiting bees, a team of researchers has determined.

“Flowers are hotspots for parasite spread between and within pollinator populations,” said Peter Graystock, a postdoctoral researcher in the Department of Entomology at the University of California, Riverside and a member of the research team. “Both the flower and bee species play a role in how likely parasite dispersal will occur.”

The study, published online in the Proceedings of the Royal Society B, is the first to show that not only can bees disperse parasites around the environment but also that flowers are platforms for a host of pollinator parasites subsequently dispersed onto visiting bees.

“By showing that visits from parasite-carrying bees can turn flowers into parasite platforms, we can say that it is likely that heavily visited flowers may become more ‘dirty’ with bee parasites,” said Graystock, the research paper’s first author.  “Planting more flowers would provide bees with more options, and parasite spread may thus be reduced.”

Photo shows a honey bee (Apis mellifera) and a bumblebee (Bombus spp.) foraging

on a purple coneflower. PHOTO CREDIT: KATHY KEATLEY GARVEY, UC DAVIS.

The researchers found four common honey bee and bumblebee parasites dispersed via flowers: Nosema apis (causes a honey bee disease), Nosema ceranae (causes an emergent disease in honey bees and bumblebees), Crithidia bombi (causes a bumblebee disease) and Apicystis bombi (mostly found in bumblebees). These parasites are known to cause, lethargy, dysentery, colony collapse, and queen death in heavily infected bees.

Photo shows a honey bee (Apis mellifera) foraging on a pansy flower.

PHOTO CREDIT: KATHY KEATLEY GARVEY, UC DAVIS.

Currently, bees are frequently transported across state and international territories.  Quarantine and parasite screening usually cover only the screening of host-specific diseases.  But bumblebees can transport honey bee parasites, and vice versa, the research team has now shown, and proposes that increased screening protocols be employed to protect pollinator diversity.

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Researchers strategize to outsmart bacteria

Rice University lab identifies mutations that allow bacteria to resist antibiotics

(August 5, 2015)  Rice University scientists are developing strategies to keep germs from evolving resistance to antibiotics by heading them off at the pass.

The Rice lab of biochemist Yousif Shamoo identified a genetic mechanism that allows bacteria to develop resistance while simultaneously and quickly spreading the capability to others in a population.

“This is really a double whammy,” Shamoo said. “Our finding that these bacteria become more antibiotic-resistant while at the same time spreading their resistance more efficiently was really surprising and worrying.”

The researchers hope this knowledge will help predict when and how bacterial strains are likely to develop resistance to future antibiotics and perhaps act to halt — or at least slow — the process. The research appeared in the journal Molecular Biology and Evolution.

Antibiotic resistance is responsible for hundreds of thousands of infections acquired in American hospitals, according to the Centers for Disease Control and Prevention. These infections kill thousands of patients. While progress is being made to control microbes that spread infection, the overriding concern remains that drugs developed to kill germs will ultimately stop working.

Until now, the only effective way to keep antibiotics from losing their potency has been to use them sparingly, said Kathryn Beabout, a Rice graduate student and lead author of the new paper.

“The best you can do is try to manage when you use the antibiotic,” she said. “But our idea is that if we can predict how resistance is going to emerge, we can come up with strategies to use antibiotics in a more intelligent way.”

The lab used experimental evolution to study a specific combination of bacteria and an antibiotic that had not been in common contact. The bacteria of interest was Enterococcus faecalis, found in the gastrointestinal tract. The antibiotic was tigecycline, a highly effective but sparingly used derivative of tetracycline. The goal was to see how horizontal gene transfer – the means by which cells pass along favorable mutations – would work in the presence of the antibiotic.

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Berkeley Lab Spinoff Company Makes Fast, Accurate Nanoscale Sensor

Optokey’s Robert Chebi (left) and Frank Chen are commercializing a nanoscale sensor

developed at Berkeley Lab. (Photo by Julie Chao)

Optokey’s “biochemical nose” can be used in food safety, medical diagnosis, chemical analysis, and a wide array of other fields.

(August 5, 2015)  Imagine being able to test your food in your very own kitchen to quickly determine if it carried any deadly microbes. Research conducted at Lawrence Berkeley National Laboratory (Berkeley Lab) and now being commercialized by Optokey may make that possible.

Optokey, a startup based in Hayward, California, has developed a miniaturized sensor based on Raman spectroscopy that can quickly and accurately detect or diagnose substances at a molecular level. “Our system can do chemistry, biology, biochemistry, molecular biology, clinical diagnosis, and chemical analysis,” said company president and co-founder Fanqing Frank Chen. “And our system can be implemented very cheaply, without much human intervention.”

The technology is based on surface-enhanced Raman spectroscopy, a technique for molecular fingerprinting. While SERS is a highly sensitive analytical tool, the results are not easily reproducible. As a scientist at Berkeley Lab, Chen and colleagues developed a solution to this problem using what they called “nanoplasmonic resonators,” which measures the interaction of photons with an activated surface using nanostructures in order to do chemical and biological sensing. The method produces measurements much more reliably.

“At Optokey we’re able to mass produce this nanoplasmonic resonator on a wafer scale,” Chen said. “We took something from the R&D realm and turned it into something industrial-strength.”

The miniaturized sensors use a microfluidic control system for “lab on a chip” automated liquid sampling. The company is taking a page from the semiconductor industry in making its chip. “We’re leveraging knowledge acquired from high-tech semiconductor manufacturing methods to get the cost, the volume, and the accuracy in the chip,” said VP of Manufacturing Robert Chebi, a veteran of the microelectronic industry who previously worked at Lam Research and Applied Materials. “We’re also leveraging all the knowledge in lasers and optics for this specific Raman-based method.”

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Atomic View of Microtubules

Berkeley Lab Researchers Achieve Record 3.5 Angstroms Resolution and Visualize Action of a Major Microtubule-Regulating Protein

(August 5, 2015)  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 that enabled them to identify the crucial role played by a family of end-binding (EB) proteins in regulating microtubule dynamic instability.

During mitosis, microtubules disassemble 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.

“Our study shows how EB proteins can either facilitate microtubule assembly by binding to sub-units of the microtubule, essentially holding them together, or else cause a microtubule to disassemble by promoting GTP hydrolysis that destabilizes the microtubule lattice,” says Eva Nogales, 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.

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