When rain falls on a lotus leaf, the leaf doesn’t get wet. Thanks to its special structure, the water drops roll off without wetting the surface. Artificial materials can be made water-repellent, too. It is, however, extremely challenging to produce a surface with switchable wetting. Now, a research team from TU Wien, KU Leuven and University of Zürich has managed to manipulate a surface of a single layer of boron nitride in such a way that it can be switched back and forth between states with high and low wetting and adhesion.
Hexagons making waves
One of the most interesting physical properties of a surface is its stiction or static friction” says Stijn Mertens (Institute of Applied Physics at the Vienna University of Technology, and associated with KU Leuven in Belgium). „This force has to be overcome for an object on the surface to start sliding.” The nanostructure of the surface determines its stiction to a large extent: the details of the contact between the surface and another object (for example, a drop of liquid) depend on the geometry of its atoms and other properties. This in turn is crucial for adhesion, stiction and wetting. The relationship between stiction and wetting, however, is so far only poorly understood.
“Just as the material graphene consists of only one layer of carbon atoms, our boron nitride — which contains as many boron as nitrogen atoms — has a thickness of only one atomic layer”, explains Thomas Greber from the Physics Institute at the University of Zürich. This ultrathin layer can be grown on a rhodium single crystal. The atoms on the rhodium surface and in the boron nitride form a hexagonal pattern, but the distances between the atoms in the two materials are different. Thirteen atoms in boron nitride take the same space as twelve rhodium atoms, so that the two crystals do not fit together perfectly. Because of this mismatch, the boron nitride hexagons must bend, they appear as a frozen wave with a wavelength of 3.2 nanometres and a height of about 0.1 nanometres.
Precisely this two-dimensional nanowave influences the wetting of the surface by water”, says Stijn Mertens. In any case, the boron nitride superstructure can be made flat with a simple trick: by putting the material in acid and applying an electrical voltage, hydrogen atoms creep under the boron nitride layer and change the bond between nitrogen and rhodium. This makes the boron nitride flat. Suddenly the adhesion of a water drop on the surface changes dramatically – even though the drop is 100’000 times bigger than the tiny waves in the boron nitride. If the voltage is decreased, this effect is reversed: „We can switch the surface again and again between these two states”, explains Stijn Mertens.
Human beings inherit many genetic traits directly from their parents. However, cultural traits — tools, beliefs and behaviors that are transmitted by learning — can be passed on not only by parents but also teachers and peers. Many animals have learned behaviors, but people are uniquely good at building on existing knowledge to innovate further. This capacity, known as cumulative culture, was captured by Sir Isaac Newton when he said, “If I have seen further, it is by standing on the shoulders of giants.”
We can see evidence of this cumulative culture in the archaeological record; over time, there’s an accelerating increase in the number of tools people use. But the archaeological record reveals another pattern, too: there’s also evidence for large-scale losses of culture. For example, archaeological excavation suggests that Aboriginal populations in Tasmania lost numerous technologies over time, including nets, bone tools and warm clothing, even though these tools might still have been useful.
And it doesn’t seem like cultural accumulation just proceeds through time at a regular pace. The archaeological record shows some evidence of large bursts of innovation occurring after relatively long periods of little change. For example, the early human archaeological record is composed primarily of stone tools for approximately two million years. Then, from about 60,000 to 30,000 years ago, archaeologists find a burst of creative activity, such as burial sites, art forms including cave paintings and statues, and engraved bone and antler tools.
The U.S. Department of Energy’s Ames Laboratory has created a faster, cleaner biofuel refining technology that not only combines processes, it uses widely available materials to reduce costs.
Ames Laboratory scientists have developed a nanoparticle that is able to perform two processing functions at once for the production of green diesel, an alternative fuel created from the hydrogenation of oils from renewable feedstocks like algae.
The method is a departure from the established process of producing biodiesel, which is accomplished by reacting fats and oils with alcohols.
“Conventionally, when you are producing biodiesel from a feedstock that is rich in free fatty acids like microalgae oil, you must first separate the fatty acids that can ruin the effectiveness of the catalyst, and then you can perform the catalytic reactions that produce the fuel,” said Ames Lab scientist Igor Slowing. “By designing multifunctional nanoparticles and focusing on green diesel rather than biodiesel, we can combine multiple processes into one that is faster and cleaner.” Contrary to biodiesel, green diesel is produced by hydrogenation of fats and oils, and its chemical composition is very similar to that of petroleum-based diesel. Green diesel has many advantages over biodiesel, like being more stable and having a higher energy density.
An Ames Lab research group, which included Slowing, Kapil Kandel, Conerd Frederickson, Erica A. Smith, and Young-Jin Lee, first saw success using bi-functionalized mesostructured nanoparticles. These ordered porous particles contain amine groups that capture free fatty acids and nickel nanoparticles that catalyze the conversion of the acids into green diesel. Nickel has been researched widely in the scientific community because it is approximately 2000 times less expensive as an alternative to noble metals traditionally used in fatty acid hydrogenation, like platinum or palladium.
Creating a bi-functional nanoparticle also improved the resulting green diesel. Using nickel for the fuel conversion alone, the process resulted in too strong of a reaction, with hydrocarbon chains that had broken down. The process, called “cracking,” created a product that held less potential as a fuel.
“A very interesting thing happened when we added the component responsible for the sequestration of the fatty acids,” said Slowing. “We no longer saw the cracking of molecules. So the result is a better catalyst that produces a hydrocarbon that looks much more like diesel. “
“It also leaves the other components of the oil behind, valuable molecules that have potential uses for the pharmaceutical and food industries,” said Slowing.
But Slowing, along with Kapil Kandel, James W. Anderegg, Nicholas C. Nelson, and Umesh Chaudhary, took the process further by using iron as the catalyst. Iron is 100 times cheaper than nickel. Using iron improved the end product even further, giving a faster conversion and also reducing the loss of CO2 in the process.
“As part of the mission of the DOE, we are focused on researching the fundamental science necessary to create the process; but the resulting technology should in principle be scalable for industry,” he said.
There’s more to it than geography and corporate culture
After decades of bafflement and frustration, the world is still struggling to guess the secret of Silicon Valley’s success. Sure, the towns and cities at the San Francisco Bay’s southern end have plenty of high-tech talent, but that’s scarcely an explanation: those ambitious young engineers and innovators could find work just about anywhere they choose.
You can list the features that brought so many of them to the valley, but the riddle remains. Yes, the surrounding area has its share of universities, government research centers and commercial labs. And a start-up could hardly ask for more encouraging circumstances: a large pool of highly educated workers; access to plentiful venture capital; and a highly entrepreneurial, risk-taking culture.
But Silicon Valley has no monopoly on any of those features. To be sure, pockets of innovation have emerged on a smaller scale elsewhere in the U.S., like North Carolina’s Research Triangle and the Route 128 Corridor outside Boston. All the same, comparable advantages have been of little help to areas such as northern New Jersey, with the legendary Bell Labs and leading universities, along with proximity to Wall Street, the world capital of high-stakes investment.
Countries around the world are doing their best to copy the valley’s magic. Take China, where companies in a variety of industries have boosted their research and development spending by an average of 64 percent every year for the past five years, and the Beijing government is making huge investments in the country’s university system. The hope is that such an infusion of resources will generate a Silicon Valley–style symbiosis between industry and the research sector. The effort has been massive, but so far the results are anything but.
What are the valley’s emulators missing? As authors of The Culture of Innovation: What Makes San Francisco Bay Area Companies Different?, a 2012 joint study by the Bay Area Council Economic Institute and Booz & Co., we attempted to answer that question. What we found was a special trait that distinguishes Silicon Valley’s firms from ordinary companies: the ability to integrate their innovation strategies with their business strategies.
That one trait can make the difference between success and mediocrity—or worse. Our survey reported that Silicon Valley firms are almost four times as likely as the average U.S. company on Booz & Co.’s annual Global Innovation 1000 study to have a tight alignment of their overall corporate strategy with their innovation strategy. Not coincidentally, the corporate culture of a Silicon Valley firm is also two and a half times more likely to be attuned to the company’s innovation strategy.
Coordination like that can pay big dividends. According to the Global Innovation 1000 study, companies that successfully mesh their innovation strategies with their corporate aims grow far more vigorously than those that don’t, both in profitability and in net worth. And to underscore the importance of innovation, Silicon Valley companies are four times as likely as others to shake up their own status quo by hiring new product-development talent.
Fewer than three million monarch butterflies have shown up so far this year
ON the first of November, when Mexicans celebrate a holiday called the Day of the Dead, some also celebrate the millions of monarch butterflies that, without fail, fly to the mountainous fir forests of central Mexico on that day. They are believed to be souls of the dead, returned.
This year, for or the first time in memory, the monarch butterflies didn’t come, at least not on the Day of the Dead. They began to straggle in a week later than usual, in record-low numbers. Last year’s low of 60 million now seems great compared with the fewer than three million that have shown up so far this year. Some experts fear that the spectacular migration could be near collapse.
“It does not look good,” said Lincoln P. Brower, a monarch expert at Sweet Briar College.
It is only the latest bad news about the dramatic decline of insect populations.
Another insect in serious trouble is the wild bee, which has thousands of species. Nicotine-based pesticides called neonicotinoids are implicated in their decline, but even if they were no longer used, experts say, bees, monarchs and many other species of insect would still be in serious trouble.
That’s because of another major factor that has not been widely recognized: the precipitous loss of native vegetation across the United States.
“There’s no question that the loss of habitat is huge,” said Douglas Tallamy, a professor of entomology at the University of Delaware, who has long warned of the perils of disappearing insects. “We notice the monarch and bees because they are iconic insects,” he said. “But what do you think is happening to everything else?”
A big part of it is the way the United States farms. As the price of corn has soared in recent years, driven by federal subsidies for biofuels, farmers have expanded their fields. That has meant plowing every scrap of earth that can grow a corn plant, including millions of acres of land once reserved in a federal program for conservation purposes.
Another major cause is farming with Roundup, a herbicide that kills virtually all plants except crops that are genetically modified to survive it.
As a result, millions of acres of native plants, especially milkweed, an important source of nectar for many species, and vital for monarch butterfly larvae, have been wiped out. One study showed that Iowa has lost almost 60 percent of its milkweed, and another found 90 percent was gone. “The agricultural landscape has been sterilized,” said Dr. Brower.
The loss of bugs is no small matter. Insects help stitch together the web of life with essential services, breaking plants down into organic matter, for example, and dispersing seeds. They are a prime source of food for birds. Critically, some 80 percent of our food crops are pollinated by insects, primarily the 4,000 or so species of the flying dust mops called bees. “All of them are in trouble,” said Marla Spivak, a professor of apiculture at the University of Minnesota.
Farm fields are not the only problem.
Scientists at Cold Spring Harbor Laboratory (CSHL) and five other institutions have used an unconventional approach to cancer drug discovery to identify a new potential treatment for acute myeloid leukemia (AML).
As reported in Nature online on August 3, the scientists have pinpointed a protein called Brd4 as a novel drug target for AML, an aggressive blood cancer that is currently incurable in 70% of patients. Using a drug compound that inhibits the activity of Brd4, the scientists were able to suppress the disease in experimental models.
“The drug candidate not only displays remarkable anti-leukemia activity in aggressive disease models and against cells derived from patients with diverse, genetic subtypes of AML, but is also minimally toxic to non-cancerous cells,” says CSHL scientist Chris Vakoc, M.D., Ph.D., who led the team. “The drug is currently being developed for therapeutic use for cancer patients by Tensha Therapeutics and is expected to enter clinical trials within two years.”
The protein target identified in the RNAi screen described in the current study, Brd4 — which contains a distinct domain or region known as a bromodomain — is a member of the BET family of proteins, which help regulate gene expression. By “reading” certain epigenetic marks or chemical tags attached to chromatin — the combined package of DNA and proteins around which it is coiled within the cell’s nucleus — Brd4 helps control the pattern of which genes are switched on and how they work.
“Cancer is clearly a genetic disease, but we also appreciate that epigenetic changes in how genes are expressed contribute to the uncontrolled growth of cancer cells,” says Vakoc. Cancer cells exploit this altered epigenetic landscape to drive their cell-growth programs.
Vakoc and other scientists have seized on the idea of interfering with this epigenetic dependency to turn the tables on cancer. “Epigenetic alterations acquired during cancer progression are potentially reversible and therefore susceptible to drug intervention,” he explains. With this insight as the backbone of their strategy to find new therapies for cancer, “we began to systematically search for what the cancer needs to keep itself going, to find a way to shut down that cancer-fueling factor and develop a new therapy.”
A new invention may make things easier for patients with serious bone injuries.
From wounded warriors to cancer patients to accident victims, there are an estimated 500,000 bone graft procedures every year in the U.S.
The bone graft breakthrough takes its cue from a most unusual source: an ingredient found in carpet padding.
Instead of having to use a patient’s own bones or a cadaver source, researchers at the University of Texas at San Antonio are developing something similar to help build bones, using a medical grade of polyurethane foam, the porous, spongy stuff you can find in everything from toys to carpet padding.
Dr. Joo Ong, a professor of biomedical engineering, co-invented the bone scaffold. He says it can be used instead of bone grafts for injuries as small as five millimeters.
Calcium phosphate, the mineral found naturally in bone, coats the polyurethane foam. Then it’s put in a furnace. Less than 24 hours later, the foam burns away. The calcium phosphate takes its shape, hardening into a scaffold.
Meat grown using tissue engineering techniques, so-called ‘cultured meat’, would generate up to 96% lower greenhouse gas emissions than conventionally produced meat, according to a new study.
The analysis, carried out by scientists from Oxford University and the University of Amsterdam, also estimates that cultured meat would require 7-45% less energy to produce than the same volume of pork, sheep or beef. It would require more energy to produce than poultry but only a fraction of the land area and water needed to rear chickens.
A report of the team’s research is published in the journal Environmental Science & Technology.
‘What our study found was that the environmental impacts of cultured meat could be substantially lower than those of meat produced in the conventional way,’ said Hanna Tuomisto of Oxford University’s Wildlife Conservation Research Unit, who led the research. ‘Cultured meat could potentially be produced with up to 96% lower greenhouse gas emissions, 45% less energy, 99% lower land use, and 96% lower water use than conventional meat.’
Researchers say that sharp-edged nanoparticles can block neurodegenerative proteins that impede cognitive function.
The next challenge is making nanoparticles in this shape out of nontoxic materials.
Nanoparticles have been investigated in recent years as tools for defending the brain against neurotoxic proteins that may contribute to the onset of several different neurodegenerative disorders including Alzheimer’s disease. Such proteins, in particular amyloid-beta peptides, are thought to play a role depositing fibrous plaques on the brain that damage synapses(the contact points between neurons) and lead to a decline in cognitive capabilities.
During the onset of Alzheimer’s, amyloid beta collects in the brain centers that form new memories. As the disease progresses, these toxic protein fragments block neurotransmitters from reaching receptors on neurons. The promise of nanoparticles is that their capacity to mimic some biological functions as well as penetrate the blood–brain barrier will enable them to stop the growth of neuron-blocking fibrils better than drug compounds that might contain some variation of short peptides, antibodies or proteins—such as human serum albumin (HSA) protein. (There currently are no anti-Alzheimer’s drugs on the market.) Whereas such compounds have been shown to interfere with fibril formation, researchers are hoping that inorganic nanoparticles can do so more effectively.
Although the nanotech approach has great potential, the challenges are many, including finding a nanoparticle material that is effective yet also biocompatible and nontoxic. Another source of controversy: some nanoparticles that have been studied, including quantum dots and carbon nanotubes, seem to actually promote or accelerate fibrillation rather than prevent it.
A multidisciplinary team of researchers from the University of Michigan at Ann Arbor(U.M.) and South Korea’s Kyungpook National University claim to have resolved at least some of nanotech’s shortcomings in tackling amyloid-beta peptides. In a study published online last month in Angewandte Chemie International Edition the researchers describe inhibiting amyloid-beta fibrillation using cadmium telluride (CdTe) nanoparticles with a tetrahedral shape and negative charge.
“We decided to look at how inorganic materials can affect fibrillation of amyloid peptides, which are small proteinlike structures that form extended assemblies that look like nanofibers,” says Nicholas Kotov, a U.M. chemical engineering professor who led the study.
Whereas as these CdTe nanoparticles are not biocompatible and would be toxic in the body, the researchers chose them because they resemble in size, charge and behavior some of the proteins that have proved effective in blocking fibrillation.
Wine glasses that don’t shatter? Baby bottles that don’t break? Coffee mugs that last generations?
All are possible with a new process for strengthening glass and ceramics developed by an Alfred University researcher.
Alfred University has signed a royalty agreement with Santanoni Glass and Ceramics, Inc., of Alfred Station, NY, for proprietary technology related to the strengthening of glass.
The process allows Santanoni to produce “unbreakable” glassware such as wine glasses, canning jars, bottles, tumblers, goblets and mugs at a cost that allows the products to be competitive with normal, un-strengthened glassware.