Scientists Guide Gold Nanoparticles to Form "Diamond" Superlattices

Schematic illustration of the experimental strategy: Double stranded DNA bundles (gray) form

tetrahedral cages. Single stranded DNA strands on the edges (green) and vertices (red) match up with

complementary strands on gold nanoparticles. This results in a single gold particle being trapped

inside each tetrahedral cage, and the cages binding together by tethered gold nanoparticles at each

vertex. The result is a crystalline nanoparticle lattice that mimics the long-range order of crystalline

diamond. The images below the schematic are (left to right): a reconstructed cryo-EM density map of

the tetrahedron, a caged particle shown in a negative-staining TEM image, and a diamond superlattice

shown at high magnification with cryo-STEM.

(February 5, 2016)  DNA scaffolds cage and coax nanoparticles into position to form crystalline arrangements that mimic the atomic structure of diamond

Using bundled strands of DNA to build Tinkertoy-like tetrahedral cages, scientists at the U.S. Department of Energy's Brookhaven National Laboratory have devised a way to trap and arrange nanoparticles in a way that mimics the crystalline structure of diamond. The achievement of this complex yet elegant arrangement, as described in a paper published February 5, 2016, in Science, may open a path to new materials that take advantage of the optical and mechanical properties of this crystalline structure for applications such as optical transistors, color-changing materials, and lightweight yet tough materials.

"We solved a 25-year challenge in building diamond lattices in a rational way via self-assembly," said Oleg Gang, a physicist who led this research at the Center for Functional Nanomaterials (CFN) at Brookhaven Lab in collaboration with scientists from Stony Brook University, Wesleyan University, and Nagoya University in Japan.

Brookhaven Lab Center for Functional Nanomaterials (CFN) scientists Kevin Yager, Huolin Xin,

Wenyan Liu (seated), Alex Tkachenko (back), and Oleg Gang with a sample of gold nanoparticle

superlattices linked up by using fabricated DNA as a building material. The computer screen shows

the resulting simple-FCC (left) and diamond (right) crystal lattices formed by the nanoparticles,

as revealed by cryo scanning transmission electron microscopy at the CFN.

The scientists employed a technique developed by Gang that uses fabricated DNA as a building material to organize nanoparticles into 3D spatial arrangements. They used ropelike bundles of double-helix DNA to create rigid, three-dimensional frames, and added dangling bits of single-stranded DNA to bind particles coated with complementary DNA strands.

"We're using precisely shaped DNA constructs made as a scaffold and single-stranded DNA tethers as a programmable glue that matches up particles according to the pairing mechanism of the genetic code—A binds with T, G binds with C," said Wenyan Liu of the CFN, the lead author on the paper. "These molecular constructs are building blocks for creating crystalline lattices made of nanoparticles."

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Walking on Water: USU Researchers Unravel Science of Skipping Spheres

A high-speed camera captured this image of an elastic sphere bouncing off the water surface in a tank.

(photo: Chris Mabey)

(February 5, 2016)  It takes a perfect flick of the wrist and just the right angle to get a disk-shaped stone to skip across the surface of the water multiple times. So why is it so easy to get such impressive water-skipping performance from an elastic ball with only a mediocre launch?

Researchers at Utah State University’s College of Engineering say they have some answers that may offer new insight into water impact physics — an important area of study in naval applications and maritime and ocean engineering.

In collaboration with scientists at the Naval Undersea Warfare Center in Newport, R.I., and Brown University, assistant professor of mechanical engineering Tadd Truscott and his associates at USU’s Splash Lab have unraveled the physics of how elastic spheres bounce on water more easily than rigid ones. Truscott and his collaborators published their findings in the latest edition of Nature Communications — an online open access interdisciplinary journal.

Assistant Professor Tadd Truscott, right, works with graduate student Nathan Speirs at the Splash Lab. Truscott is studying

material compliance as it relates to water impact physics. 

The team uses high-speed cameras to capture images of elastic spheres bouncing across tanks of water in a laboratory. They found that elastic spheres skip along the water surface by deforming into an ideal disk-like geometry that resembles a stone one might find near the shore. Due to the sphere’s deformed shape, the water exerts a larger lifting force on elastic spheres than stones.

Truscott’s study not only reveals the physics of how elastic spheres interact with water, but also predicts how many skips will occur. In addition, the team found that elastic spheres can bounce off the water surface from much higher impact angles compared to rigid spheres — a big clue into why these elastic objects are much easier to skip.

Skipping objects along the water surface has a wide range of applications from simple aquatic toys, to naval operations like the WWII-era Wallis Bomb, or the water-walking locomotion of the Basilisk lizard.

Truscott’s setup may look like fun and games, but behind the scenes he and his team are conducting highly technical research with funding from the U.S. Navy. His work could help make inflatable boats and other soft-hull vessels safer for passengers and, on a more playful note, improve the design of water toys.

One such toy, the Water Bouncing Ball, or Waboba for short, was the inspiration for this study.

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Scientists Take Key Step Toward Custom-made Nanoscale Chemical Factories

The shell of a bacterial microcompartment (or BMC) is mainly composed of hexagonal proteins, with

pentagonal proteins capping the vertices, similar to a soccer ball (left). Scientists have engineered one

of these hexagonal proteins, normally devoid of any metal center, to bind an iron-sulfur cluster

(orange and yellow sticks, upper right). This cluster can serve as an electron relay to transfer

electrons across the shell. Introducing this new functionality in the shell of a BMC greatly expands

their possibilities as custom-made bio-nanoreactors.

(Credit: Clément Aussignargues/MSU, Cheryl Kerfeld and Markus Sutter/Berkeley Lab)

(February 5, 2016)  Scientists have for the first time reengineered a building block of a geometric nanocompartment that occurs naturally in bacteria. They introduced a metal binding site to its shell that will allow electrons to be transferred to and from the compartment. This provides an entirely new functionality, greatly expanding the potential of nanocompartments to serve as custom-made chemical factories.

Scientists hope to tailor this new use to produce high-value chemical products, such as medicines, on demand.

The sturdy nanocompartments, which are polyhedral shells composed of triangle-shaped sides and resemble 20-sided dice, are formed by hundreds of copies of just three different types of proteins. Their natural counterparts, known as bacterial microcompartments or BMCs, encase a wide variety of enzymes that carry out highly specialized chemistry in bacteria.

Scientists have reengineered nanoscale polyhedral shells, which have a natural

structure resembling the 20-sided die in this photo, to include a metal

cluster that gives the shells a new function. (Credit: Flickr/CGPsGrey.com)

Researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) devised synthetic shell structures derived from those found in a rod-shaped, ocean-dwelling bacterium, Haliangium ochraceum, and reengineered one of the shell proteins to serve as a scaffold for an iron-sulfur cluster found in many forms of life. The cluster is known as a “cofactor” because it can serve as a helper molecule in biochemical reactions.

BMC-based shells are tiny, durable and naturally self-assemble and self-repair, which makes them better-suited for a range of applications than completely synthetic nanostructures.

This image shows a natural atomic-scale protein structure (middle) in a polyhedral bacterial

microcompartment (left), and an engineered structure (right) that binds an iron-sulfur cluster

(in blue), giving it a new function. The engineered protein was produced in E. Coli bacteria—the

background image shows a scanning electron micrograph image of E. Coli.

(Credit: Berkeley Lab, National Institutes of Health)

“This is the first time anyone has introduced functionality into a shell. We thought the most important functionality to introduce was the ability to transfer electrons into or out of the shell,” said Cheryl Kerfeld, a structural biologist at Berkeley Lab and corresponding author in this study. Kerfeld’s research group focuses on BMCs. Kerfeld holds joint appointments with Berkeley Lab’s Molecular Biophysics and Integrated Bioimaging (MBIB) Division, UC Berkeley and the MSU-DOE Plant Research Laboratory at Michigan State University (MSU).

“That greatly enhances the versatility of the types of chemistries you can encapsulate in the shell and the spectrum of products to be produced,” she said. “Typically, the shells are thought of as simply passive barriers.”

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Battery technology could charge up water desalination

Inspired by the principles of a conventional sodium ion battery, Illinois mechanical science

and engineering professor Kyle Smith, right, and graduate student Rylan Dmello found they

could desalinate salt water more efficiently than using traditional methods. Photo by L. Brian Stauffer

(February 5, 2016)  The technology that charges batteries for electronic devices could provide fresh water from salty seas, says a new study by University of Illinois engineers. Electricity running through a salt water-filled battery draws the salt ions out of the water.

Illinois mechanical science and engineering professor Kyle Smith and graduate student Rylan Dmello published their work in the Journal of the Electrochemical Society.

“We are developing a device that will use the materials in batteries to take salt out of water with the smallest amount of energy that we can,” Smith said. “One thing I’m excited about is that by publishing this paper, we’re introducing a new type of device to the battery community and to the desalination community.”

Interest in water desalination technology has risen as water needs have grown, particularly in drought-stricken areas. However, technical hurdles and the enormous amounts of energy required have prevented wide-scale implementation. The most-used method, reverse osmosis, pushes water through a membrane that keeps out the salt, a costly and energy-intensive process. By contrast, the battery method uses electricity to draw charged salt ions out of the water.

The researchers were inspired by sodium ion batteries, which contain salt water. Batteries have two chambers, a positive electrode and a negative electrode, with a separator in between that the ions can flow across. When the battery discharges, the sodium and chloride ions – the two elements of salt – are drawn to one chamber, leaving desalinated water in the other.

In a normal battery, the ions diffuse back when the current flows the other direction. The Illinois researchers had to find a way to keep the salt out of the now-pure water.

“In a conventional battery, the separator allows salt to diffuse from the positive electrode into the negative electrode,” Smith said. “That limits how much salt depletion can occur. We put a membrane that blocks sodium between the two electrodes, so we could keep it out of the side that’s desalinated.”

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Lithium battery catalyst found to harm key soil microorganism

Shewanella oneidensis thrives on metal ions, converting them to metals like iron that serve as

nutrients for other microbes. The bacterium was shown to be harmed by the compound nickel

manganese cobalt oxide, which is produced in nanoparticle form and is poised to become the

dominant material in the lithium ion batteries that will power portable electronics and electric vehicles.

(Illustration by Ella Marushchenko, University of Minnesota)

(January 4, 2016 )  The material at the heart of the lithium ion batteries that power electric vehicles, laptop computers and smartphones has been shown to impair a key soil bacterium, according to new research published online in the journal Chemistry of Materials.

The study by researchers at the University of Wisconsin—Madison and the University of Minnesota is an early signal that the growing use of the new nanoscale materials used in the rechargeable batteries that power portable electronics and electric and hybrid vehicles may have untold environmental consequences.

Researchers led by UW–Madison chemistry Professor Robert J. Hamers explored the effects of the compound nickel manganese cobalt oxide (NMC), an emerging material manufactured in the form of nanoparticles that is being rapidly incorporated into lithium ion battery technology, on the common soil and sediment bacterium Shewanella oneidensis.

“As far as we know, this is the first study that’s looked at the environmental impact of these materials,” says Hamers, who collaborated with the laboratories of University of Minnesota chemist Christy Haynes and UW–Madison soil scientist Joel Pedersen to perform the new work.

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40 years of science: Organic ag key to feeding the world

An assessment of organic farming relative to conventional farming illustrates that

organic systems better balance the four areas of sustainability.

(February 4, 2016)  Washington State University researchers have concluded that feeding a growing global population with sustainability goals in mind is possible. Their review of hundreds of published studies provides evidence that organic farming can produce sufficient yields, be profitable for farmers, protect and improve the environment and be safer for farm workers.

The review study, “Organic Agriculture in the 21st Century,” is featured as the cover story for the February issue of the journal Nature Plants and was authored by John Reganold, WSU regents professor of soil science and agroecology, and doctoral candidate Jonathan Wachter.

It is the first study to analyze 40 years of science comparing organic and conventional agriculture across the four goals of sustainability identified by the National Academy of Sciences: productivity, economics, environment and community well being.

“Hundreds of scientific studies now show that organic ag should play a role in feeding the world” said lead author Reganold (http://css.wsu.edu/people/faculty/john-p-reganold). “Thirty years ago, there were just a couple handfuls of studies comparing organic agriculture with conventional. In the last 15 years, these kinds of studies have skyrocketed.”

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Researchers Discover New Phase of Boron Nitride and a New Way to Create Pure c-BN

Scanning electron micrograph of c-BN nanoneedles and microneedles up to three

microns in length. Image credit: Anagh Bhaumik.

(February 4, 2016)  Researchers at North Carolina State University have discovered a new phase of the material boron nitride (Q-BN), which has potential applications for both manufacturing tools and electronic displays. The researchers have also developed a new technique for creating cubic boron nitride (c-BN) at ambient temperatures and air pressure, which has a suite of applications, including the development of advanced power grid technologies.

“This is a sequel to our Q-carbon discovery and converting Q-carbon into diamond,” says Jay Narayan, the John C. Fan Distinguished Chair Professor of Materials Science and Engineering at NC State and lead author of a paper describing the research. “We have bypassed what were thought to be the limits of boron nitride’s thermodynamics with the help of kinetics and time control to create this new phase of boron nitride.

“We have also developed a faster, less expensive way to create c-BN, making the material more viable for applications such as high-power electronics, transistors and solid state devices,” Narayan says. “C-BN nanoneedles and microneedles, which can be made using our technique, also have potential for use in biomedical devices.” C-BN is a form of boron nitride that has a cubic crystalline structure, analogous to diamond.

Early tests indicate that Q-BN is harder than diamond, and it holds an advantage over diamond when it comes to creating cutting tools. Diamond, like all carbon, reacts with iron and ferrous materials. Q-BN does not. The Q-BN has an amorphous structure, and it can easily be used to coat cutting tools, preventing them from reacting with ferrous materials.

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Hack-proof RFID chips

Researchers have designed an RFID chip that prevents so-called side-channel attacks,

which analyze patterns of memory access or fluctuations in power usage when a device is

performing a cryptographic operation, in order to extract its cryptographic key.

Pictured here is a standard RFID chip.

(February 4, 2016)  New technology could secure credit cards, key cards, and pallets of goods in warehouses.

Researchers at MIT and Texas Instruments have developed a new type of radio frequency identification (RFID) chip that is virtually impossible to hack.

If such chips were widely adopted, it could mean that an identity thief couldn’t steal your credit card number or key card information by sitting next to you at a café, and high-tech burglars couldn’t swipe expensive goods from a warehouse and replace them with dummy tags.

Texas Instruments has built several prototypes of the new chip, to the researchers’ specifications, and in experiments the chips have behaved as expected. The researchers presented their research this week at the International Solid-State Circuits Conference, in San Francisco.

According to Chiraag Juvekar, a graduate student in electrical engineering at MIT and first author on the new paper, the chip is designed to prevent so-called side-channel attacks. Side-channel attacks analyze patterns of memory access or fluctuations in power usage when a device is performing a cryptographic operation, in order to extract its cryptographic key.

“The idea in a side-channel attack is that a given execution of the cryptographic algorithm only leaks a slight amount of information,” Juvekar says. “So you need to execute the cryptographic algorithm with the same secret many, many times to get enough leakage to extract a complete secret.”

One way to thwart side-channel attacks is to regularly change secret keys. In that case, the RFID chip would run a random-number generator that would spit out a new secret key after each transaction. A central server would run the same generator, and every time an RFID scanner queried the tag, it would relay the results to the server, to see if the current key was valid.

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Novel nanoparticle made of common mineral may help keep tumor growth at bay

(February 2, 2016)  Engineers at Washington University in St. Louis found a way to keep a cancerous tumor from growing by using nanoparticles of the main ingredient in common antacid tablets.

The research team, led by Avik Som, an MD/PhD student, and Samuel Achilefu, PhD, professor of radiology and of biochemistry & molecular biophysics in the School of Medicine and of biomedical engineering in the School of Engineering & Applied Science, in collaboration with two labs in the School of Engineering & Applied Science, used two novel methods to create nanoparticles from calcium carbonate that were injected intravenously into a mouse model to treat solid tumors. The compound changed the pH of the tumor environment, from acidic to more alkaline, and kept the cancer from growing.

With this work, researchers showed for the first time that they can modulate pH in solid tumors using intentionally designed nanoparticles. Results of the research were recently published online in Nanoscale.

“Cancer kills because of metastasis,” said Som, who is working on a doctorate in biomedical engineering in addition to a medical degree. “The pH of a tumor has been heavily correlated with metastasis. For a cancer cell to get out of the extracellular matrix, or the cells around it, one of the methods it uses is a decreased pH.”

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Jean Paul Gaultier - JPG Furniture

(February 2, 2016) Collaboration avec Jean Paul Gaultier par Lelièvre

After having been inspired by couture fashion shows and the melting pot culture of big cities, Jean Paul Gaultier now lets us discover his visions of nature - alternative, inverted, oxidised but extremely pure.

For this new fabric collection edited by Lelièvre and called Nature et Découverte, Jean Paul Gaultier imagined Oxydation (3465), a suedine of very delicate soft touch which contrasts with the roughness of the rusted metal aspect.

This soft all-purpose faux suede is used in decoration and accessories by Jean Paul Gaultier.

The lounge chairs spelling out JPG of the collection Typographia from TABISSO were chosen by Jean Paul Gaultier and Lelièvre to present and launch this new textile.

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Turning air into fuel: USC scientists convert carbon dioxide into methanol

(February 2, 2016)  The research could one day lead to a sustainable fuel source from greenhouse gas emissions

They’re making fuel from thin air at the USC Loker Hydrocarbon Research Institute.

For the first time, researchers there have directly converted carbon dioxide from the air into methanol at relatively low temperatures.

The work, led by G.K. Surya Prakash and George Olah of the USC Dornsife College of Letters, Arts and Sciences, is part of a broader effort to stabilize the amount of carbon dioxide in the atmosphere by using renewable energy to transform the greenhouse gas into its combustible cousin – attacking global warming from two angles simultaneously. Methanol is a clean-burning fuel for internal combustion engines, a fuel for fuel cells and a raw material used to produce many petrochemical products.

“We need to learn to manage carbon. That is the future,” said Prakash, professor of chemistry and director of the USC Loker Hydrocarbon Research Institute.

The researchers bubbled air through an aqueous solution of pentaethylenehexamine (or PEHA), adding a catalyst to encourage hydrogen to latch onto the CO2 under pressure. They then heated the solution, converting 79 percent of the CO2 into methanol. Though mixed with water, the resulting methanol can be easily distilled, Prakash said.

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Microreactor replaces animal testing

© Photo: Fraunhofer IZI

Scheme of the microfluidic bioreactor (top), and details of the wells containing microparticles

(oxygen probes) and cells in the background (below).

(February 2, 2016)  Researchers all over Europe are working on alternatives to animal testing that can be used to evaluate the adverse side-effects of medications. But many of these test methods still present problems. A microreactor developed as part of an EU-funded collaborative research project enables cultured liver cells to be used as test samples. Unlike animal testing, this novel method enables the assessment of potentially toxic substances on tissue in real time.

Serious efforts are underway to significantly reduce the number of animal tests carried out for research purposes. The latest EU Cosmetics Regulation, which came into force in 2013, bans the sale of cosmetic products containing ingredients that have been tested on animals. But it is difficult to find alternatives, not only for the cosmetics industry but also in the field of pharmaceutical research. In many cases, there are no other suitable methods of toxicity testing available. Numerous research groups are therefore working on the development of new, viable test formats.

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Cooling with metal muscles: Engineers develop the refrigerator of the future

(February 2, 2016)  Cooling is a hugely important process in today’s world. But how can cooling be carried out in future in a way that does not harm the climate and that helps to conserve natural resources? The approach taken by Professors Stefan Seelecke and Andreas Schütze from Saarland University focuses on systems that use shape memory materials, also known as ‘metal muscles’ or ‘artificial muscles’. Working together with researchers in Bochum, they are developing a new method of cooling in which heat and cold are transferred using ‘muscles’ made from a nickel-titanium alloy. Extensive series of tests have yielded results that are now being used to develop a prototype cooling circuit that will be used to further increase the efficiency of the process. The German Research Foundation (DFG), which has been funding the project for the last three years, has agreed to invest a further 500,000 euros. In total, the project has brought around 950,000 euros in funding to the region.

Cooling is carried out in all parts of the world. Refrigerators operate around-the-clock, air conditioning units cool offices, cooling systems help to keep computers and motors running smoothly. And the demand for cooling is being driven both by climate change and global population growth. But more cooling systems come at a price – and not just a financial one. Increased cooling means increased consumption of electrical power and therefore higher emissions of greenhouse gases into the atmosphere, driving global warming even faster. A more environmentally friendly cooling method has been developed by the research teams led by engineers Stefan Seelecke and Andreas Schütze in conjunction with the materials scientists Gunther Eggeler and Jan Frenzel at Ruhr University Bochum. The cooling process that they are developing does not require climatically harmful refrigerants and should consume less energy than the conventional cooling technologies used thus far.

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Carrara Marble Vessels

(February 2, 2016) moreno ratti casts carrara marble vessels within resin blocks

moreno ratti is an italian architect and designer that has been specializing in the context of marble since 2013. nowadays, carrara white marble is considered more and more to be sold per ton that ever before. usually, the blocks are covered with resin to increase the stress resistance imparted by cutting machines used to obtain slabs or around two to three-centimeter thickness. the italian designer has created the ‘suspended collection’ for marmo triology, referencing this process. the intention was to emphasize the material and the artisan know-how to obtain unique and not replicable objects.the marble pieces are achieved by using waste material coming from coring. the resin used symbolizes the discarded pieces called spectrum.

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Cell culture experiments reveal potent antiviral activity of Cistus incanus extracts against HIV and Ebola

(February 2, 2016)  Neuherberg, February 2, 2016. Scientists at the Helmholtz Zentrum München discover that extracts of the medicinal plant Cistus incanus (Ci) prevent human immunodeficiency viruses from infecting cells. Active antiviral ingredients in the extracts inhibit docking of viral proteins to cells. Antiviral activity of Cistus extracts also targets Ebola- and Marburg viruses. The results were published in Scientific Reports*.

Virus infections are among the ten leading causes of death worldwide and represent a major global health challenge. Their control requires the continuous development of new and potent antiviral drugs/therapeutic options.  Despite the availability of numerous drugs for chronic treatment of HIV/AIDS, new drugs are needed to prevent the emergence of drug resistant viral variants. Furthermore, new antiviral drugs are required for rapid treatment of acute infections by viruses like Marburg and Ebola viruses during acute viral outbreaks. A recent study by the team of Professor Ruth Brack-Werner and Dr. Stephanie Rebensburg from the Institute for Virology (VIRO) of the Helmholtz Zentrum München demonstrates that extracts of the medicinal plant attack HIV and Ebola virus particles and prevent them from multiplying in cultured cells.

HIV: broad activity, no resistance

The Brack-Werner team found potent activity of Ci extracts acted against a broad spectrum of clinical HIV-1 and HIV-2 isolates. This also included a virus isolate resistant against most available drugs. „Antiviral ingredients of Ci extracts target viral envelope proteins on infectious particles and prevent them from contacting host cells“, Brack-Werner explains. No resistant viruses were detected during long-term treatment (24 weeks) with Ci extract, indicating that Ci extract attacks viruses without causing resistance. The Brack-Werner study suggests that commercial herbal extracts from plants like Cistus incanus*or other plants like Pelargonium sidoides** are promising material for the development of scientifically validated antiviral phytotherapeutics. „Since antiviral activity of Ci extracts differs from all clinically approved drugs, Ci-derived products could be an important complementation to current established drug regimens“, says Brack-Werner. 

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Nature Materials: Smallest Lattice Structure Worldwide

The smallest lattice in the world is visible under the microscope only. Struts and braces

are 0.2 µm in diameter. Total size of the lattice is about 10 µm. (Photo: J. Bauer / KIT)

(February 2, 2016)  3D Lattice with Glassy Carbon Struts and Braces of Less Than 200 nm in Diameter Has Higher Specific Strength Than Most Solids

KIT scientists now present the smallest lattice structure made by man in the Nature Materials journal. Its struts and braces are made of glassy carbon and are less than 1 µm long and 200 nm in diameter. They are smaller than comparable metamaterials by a factor of 5. The small dimension results in so far unreached ratios of strength to density. Applications as electrodes, filters or optical components might be possible. (DOI: 10.1038/nmat4561)

“Lightweight construction materials, such as bones and wood, are found everywhere in nature,” Dr.-Ing. Jens Bauer of Karlsruhe Institute of Technology (KIT), the first author of the study, explains. “They have a high load-bearing capacity and small weight and, hence, serve as models for mechanical metamaterials for technical applications.”

Metamaterials are materials, whose structures of some micrometers (millionths of a meter) in dimension are planned and manufactured specifically for them to possess mechanical or optical properties that cannot be reached by unstructured solids. Examples are invisibility cloaks that guide light, sound or heat around objects, materials that counterintuitively react to pressure and shear (auxetic materials) or lightweight nanomaterials of high specific stability (force per unit area and density).

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New Research Uses Nanotechnology to Prevent Preterm Birth

(February 2, 2016)  Using nanoparticles to engineer a special drug, a team of researchers has demonstrated in mice a new way to both reduce preterm birth and avoid the risks of medication in pregnancy to unborn babies.

Jerrie S. Refuerzo, M.D., of the University of Texas Medical School at Houston (UTHealth) was frustrated with the limitations of existing tocolytic (anti-contraction or labor-repressant) medications such as indomethacin in treating women experiencing preterm labor.  These drugs can cross the placental barrier and cause a heart defect or other problems in the fetus. Dr. Refuerzo and Monica Longo, M.D., Ph.D. (UT Health), in collaboration with colleagues from Houston Methodist Research Institute, Biana Godin, PharmD, Ph.D., bioengineered an innovative microscopic nanoparticle of indomethacin aimed at reaching the pregnant uterus but not crossing the placenta to the fetus. This targeted liposomal indomethacin, called LIPINDORA, was coated with an oxytocin receptor antagonist to make it bind to uterine tissue.

LIPINDORA was given to near-term pregnant mice and the researchers found that the treated mice were significantly less likely than controls to have preterm uterine contractions or to deliver prematurely.

“These findings are exciting because we don’t currently have any medication that can reliably stop contractions or prevent preterm birth without also crossing the mom’s placenta and causing risks to babies,” explained Edward R. B. McCabe, M.D., Ph.D,, senior vice president and chief medical officer of the March of Dimes.

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LONG-TERM GLOBAL WARMING REQUIRES EXTERNAL DRIVERS

(February 1, 2016)  By examining how Earth cools itself back down after a period of natural warming, a study by scientists at Duke University and NASA’s Jet Propulsion Laboratory confirms that global temperature does not rise or fall chaotically in the long run. Unless pushed by outside forces, temperature should remain stable.

The new evidence may finally help put the chill on skeptics’ belief that long-term global warming occurs in an unpredictable manner, independently of external drivers such as human impacts. 

“This underscores that large, sustained changes in global temperature like those observed over the last century require drivers such as increased greenhouse gas concentrations,” said lead author Patrick Brown, a PhD student at Duke’s Nicholas School of the Environment.

Natural climate cycles alone are insufficient to explain such changes, he said.

Brown and his colleagues published their peer-reviewed research Feb. 1 in the Journal of Climate.

Using global climate models and NASA satellite observations of Earth’s energy budget from the last 15 years, the study finds that a warming Earth is able to restore its temperature equilibrium through complex and seemingly paradoxical changes in the atmosphere and the way radiative heat is transported.

Scientists have long attributed this stabilization to a phenomenon known as the Planck Response, a large increase in infrared energy that Earth emits as it warms. Acting as a safety valve of sorts, this response creates a negative radiative feedback that allows more of the accumulating heat to be released into space through the top of the atmosphere.

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Diversity of nature formulated

Specific food web formed by plants, plant eaters and top predators and their feeding

connections. Plants are capable of using basic chemical or physical nutrients to live and

reproduce, this means there is a flow of energy from the nutrients to the plants. Plant-eating

animals may live exclusively on the available plants while top predators feed on other animals.

(Credit: Jan Härter, Niels Bohr Institute)

(February 1, 2016) We humans are affecting nature to a greater and greater degree and this is contributing to the reduction of biodiversity globally. To better assess the consequences requires a better understanding of the environmental conditions that the species in an ecosystem live under. A group of biophysicists from the Niels Bohr Institute have therefore analysed data and calculated how the species in an area affect each other and how an ecosystem can be in balance or out of balance. The results are published in the scientific journal, PLoS Computational Biology.

 Mathematically, coexistence means that a path through the interaction matrix, formed by all

species in the food web, can be found. The figure visualizes an example interaction matrix,

with white boxes connecting neighbor trophic levels contain non-zero elements.

The path consists of using the combination of a given row and column only once,

as shown by blue boxes. The connections to the nutrient source, shown by yellow, which

feeds all species at the bottom layer, can - but need not – be used as a part of the path.

In the given case, there are 4 basal species, e.g. plants, 5 plant eaters, and 2 top predators.

(Credit: Jan Härter, Niels Bohr Institute)

In nature, animals move around and encroach into new areas where other animals have their habitat.   Here they might be prey for some of the original animals and they can also be eaten themselves. They are all part of the food chain. This pattern of eating and being eaten can be in balance or it can lead to disturbances in the environment, for example when rabbits were introduced in Australia and the rabbits multiplied dramatically, as they had no natural enemies.

But how do you know if an ecosystem is in balance? Can you even formulate it? Yes, a group of biophysicists from the Niels Bohr Institute has done it. The formula is called Lotka-Volterra and it is used to calculate the mutual influence, which is a key factor in a sustainable coexistence.

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Switching light with a silver atom

The switch is based on the voltage-induced displacement of one or more silver atoms

in the narrow gap between a silver and a platinum plate.

(Illustration: Alexandros Emboras / ETH Zurich)

(February 1, 2016)  Researchers working under Juerg Leuthold, Professor of Photonics and Communications, have created the world’s smallest integrated optical switch. Applying a small voltage causes an atom to relocate, turning the switch on or off.

The quantity of data exchanged via communications networks around the globe is growing at a breathtaking rate. The volume of data for wired and mobile communications is currently increasing by 23% and 57% respectively every year. It is impossible to predict when this growth will end. This also means that all network components must constantly be made more efficient.

These components include so-called modulators, which convert the information that is originally available in electrical form into optical signals. Modulators are therefore nothing more than fast electrical switches that turn a laser signal on or off at the frequency of the incoming electrical signals. Modulators are installed in data centres in their thousands. However, they all have the disadvantage of being quite large. Measuring a few centimetres across, they take up a great deal of space when used in large numbers.

From micromodulators to nanomodulators

Six months ago, a working group led by Jürg Leuthold, Professor of Photonics and Communications already succeeded in proving that the technology could be made smaller and more energy-efficient. As part of that work, the researchers presented a micromodulator measuring just 10 micrometres across – or 10,000 times smaller than modulators in commercial use

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A highway for spin waves

The spin wave remains trapped in the domain wall, which is formed in the middle

between the differently oriented magnetizations. Researchers at the HZDR could

thus control its propagation purposefully. Foto: HZDR/H. Schultheiß

(February 1, 2016)  Researchers in Dresden develop process for controlling innovative information media

The success story of information processing by way of moving electrons is slowly coming to an end. The trend towards more and more compact chips constitutes a major challenge for manufacturers, since the increasing miniaturization creates partly unsolvable physical problems. This is why magnetic spin waves could be the future: they are faster than electronic charge carriers and use less power. Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and TU Dresden have developed a method for controlling the propagation of these information carriers at the nanolevel in a targeted and simple way; so far, this required a lot of power. They have thus created a basis for nanocircuits that use spin waves.

"Our current information processing is based on electrons," explains Dr. Helmut Schultheiß from the HZDR's Institute of Ion Beam Physics and Materials Research. "These charged particles flow through the wires, creating electric currents. Yet in the process they collide with atoms and lose energy, which escapes into the crystal lattice in the form of heat. This means that chips get all the warmer, the closer the elements on them are grouped together. Eventually they fail, because the heat cannot be conveyed anymore." This is why Schultheiß, head of an Emmy Noether Junior Research Group, pursues a different approach: information transport via spin waves, also known as magnons.

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Turning good vibrations into energy

(February 1, 2016)  Mechanical trees become power ‘plants’ when they sway in breeze

New tools for harvesting wind energy may soon look less like giant windmills and more like tiny leafless trees.

A project at The Ohio State University is testing whether high-tech objects that look a bit like artificial trees can generate renewable power when they are shaken by the wind—or by the sway of a tall building, traffic on a bridge or even seismic activity.

In a recent issue of the Journal of Sound and Vibration, researchers report that they’ve uncovered something new about the vibrations that pass through tree-shaped objects when they are shaken.

Specifically, they’ve demonstrated that tree-like structures made with electromechanical materials can convert random forces—such as winds or footfalls on a bridge—into strong structural vibrations that are ideal for generating electricity.

The idea may conjure images of fields full of mechanical trees swaying in the breeze. But the technology may prove most valuable when applied on a small scale, in situations where other renewable energy sources such as solar are not an option, said project leader Ryan Harne, assistant professor of mechanical and aerospace engineering at Ohio State, and director of the Laboratory of Sound and Vibration Research.

The “trees” themselves would be very simple structures: think of a trunk with a few branches—no leaves required.

Early applications would include powering the sensors that monitor the structural integrity and health of civil infrastructure, such as buildings and bridges. Harne envisions tiny trees feeding voltages to a sensor on the underside of a bridge, or on a girder deep inside a high-rise building.

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Small ponds produce an outsized share of greenhouse gases

Tiny ponds play a disproportionately large role in global greenhouse gas emissions from

inland waters, according to a new study by Yale’s School of Forestry & Environmental Studies.

(February 1, 2016)  Although ponds less than a quarter of an acre in size make up only 8.6% of the surface area of the world’s lakes and ponds, they account for 15.1% of carbon dioxide (CO2) emissions and 40.6% of diffusive methane (CH4) emissions. The findings appear in the Feb. 1 online edition of the journal Nature Geoscience.

“Our study is the first to include these small ponds in global estimates of CO2 and CH4 emissions, largely because they are difficult to map and were thought to play a small role in carbon cycling,” said Yale doctoral student Meredith Holgerson, the study’s lead author.

Holgerson and co-author Peter Raymond, professor of ecosystem ecology at Yale, conducted their analysis by combining recent estimates on the global number of lakes and ponds with a compilation of direct measurements of CO2 and CH4 concentrations from 427 lakes and ponds. They found that concentrations were greatest in smaller ponds and decreased as the ponds and lakes grew larger.

The reason has to do with the physical makeup of very small ponds and the way they cycle carbon. Small ponds have a high perimeter-to-surface-area ratio, for example, and accumulate a higher load of terrestrial carbon — so-called “leaf litter,” sediment particles and other material. Small ponds also tend to be shallow, which means their terrestrial carbon loads are highly concentrated compared to larger lakes. Lastly, gases produced at the bottom of these ponds are able to reach the top more often than what occurs in larger lakes, due to greater water mixing and shallower waters. Because of this, CO2 and CH4 generated in sediments affects the entire pond.

“That makes small ponds an important player in the carbon cycle,” Holgerson said.

The findings warrant additional research to more accurately estimate the number of tiny ponds around the world, she added. Such spots don’t typically show up on satellite images, but they can be mapped using aerial images and LiDAR, a remote sensing technology that uses reflected laser light. The researchers also said their findings suggest that small ponds are likely breaking down terrestrial carbon that is not factored into assessments of the world’s carbon stocks and fluxes.

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Robotic Fingers with a Gentle Touch

(February 1, 2016)  Soft electronics are changing the way robots can touch. EPFL Scientists have developed a new soft robotic gripper -- made out of rubber and stretchable electrodes -- that can bend and pick up delicate objects like eggs and paper, taking robotics to a whole new level.

Have you ever rubbed a balloon in your hair to make it stick to the wall? This electrostatic stickiness called electroadhesion may change robotics forever.

EPFL scientists have invented a new soft gripper that uses electroadhesion: flexible electrode flaps that act like a thumb-index gripper. It can pick up fragile objects of arbitrary shape and stiffness, like an egg, a water balloon or paper.

This lightweight gripper may soon be handling food for the food industry, capturing debris in outer space or incorporated into prosthetic hands. The research, which was funded by NCCR Robotics, is featured in Advanced Materials.

"This is the first time that electroadhesion and soft robotics have been combined together to grasp objects," says Jun Shintake, doctoral student at EPFL and first author of the publication.

When the voltage is turned on, the electrodes bend towards the object to be picked up, imitating muscle function. The tip of the electrodes act like fingertips that gently conform to the shape of the object, gripping onto it with electrostatic forces in the same way that the balloon sticks to the wall. These electrodes can carry 80 times its own weight and no prior knowledge about the object's shape is necessary.

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Perovskite-nanotubes take light sensitivity to new heights

 Illustration of the perovskite-enhanced photodetector. © E.Horvath (EPFL)

 (February 1, 2016)  EPFL scientists build the most sensitive carbon nanotube-based photodetector to date. The material is sensitized with CN3NH3PbI3 perovskite nanowires, which propel its responsivity by almost seven orders of magnitude.

Semiconducting carbon nanotubes are often used in photovoltaic and optoelectronic devices. But light detection with pristine carbon-nanotube field-effect phototransistors so far is limited in the range of 10% quantum efficiency. The responsivity of the best carbon nanotube devices is around 0.1 A/W. Publishing in Nanoscale, EPFL scientists have now fabricated a carbon-nanotube photodetector with responsivity as high as 7.7×105 A/W.

The lab of László Forró, led by postdocs Bálint Náfrádi and Endre Horváth, at EPFL built the device and overlaid it with perovskite (CN3NH3PbI3) nanowires to sensitize its light-detection capacity. The unprecedented high performance is a result of the two materials working together: the perovskite nanowires can convert incoming light into free charge-carriers with high efficiency, while the carbon nanotube transfers the electrons to the detection circuit.

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