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Wednesday, August 24, 2016

Earth-Mass World in Orbit Around Proxima Centauri, In Habitable Zone of Our Closet Stellar Neighbor (Videos, Photos)


Astronomers using ESO telescopes and other facilities have found clear evidence of a planet orbiting the closest star to Earth, Proxima Centauri. The long-sought world, designated Proxima b, orbits its cool red parent star every 11 days and has a temperature suitable for liquid water to exist on its surface. This rocky world is a little more massive than the Earth and is the closest exoplanet to us -- and it may also be the closest possible abode for life outside the Solar System. A paper describing this milestone finding will be published in the journal Nature on 25 August 2016.

This artist's impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image to the upper-right of Proxima itself. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface.

Credit: ESO/M. Kornmesser

The Pale Red Dot campaign aimed to find a planet orbiting our nearest stellar neighbor, Proxima Centauri. Incredibly, the quest succeeded and the team did indeed find a planet. Even more excitingly, the planet, Proxima b, falls within the habitable zone of its host star. The newly discovered Proxima b is by far the closest potential abode for alien life.

Just over four light-years from the Solar System lies a red dwarf star that has been named Proxima Centauri as it is the closest star to Earth apart from the Sun. This cool star in the constellation of Centaurus is too faint to be seen with the unaided eye and lies near to the much brighter pair of stars known as Alpha Centauri AB.

This infographic compares the orbit of the planet around Proxima Centauri (Proxima b) with the same region of the Solar System. Proxima Centauri is smaller and cooler than the Sun and the planet orbits much closer to its star than Mercury. As a result it lies well within the habitable zone, where liquid water can exist on the planet’s surface.

Credit: ESO/M. Kornmesser/G. Coleman

This artist’s impression video shows a view of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image between Proxima and the planet. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface.

Credit: ESO/M. Kornmesser

During the first half of 2016 Proxima Centauri was regularly observed with the HARPS spectrograph on the ESO 3.6-metre telescope at La Silla in Chile and simultaneously monitored by other telescopes around the world [1]. This was the Pale Red Dot campaign, in which a team of astronomers led by Guillem Anglada-Escudé, from Queen Mary University of London, was looking for the tiny back and forth wobble of the star that would be caused by the gravitational pull of a possible orbiting planet [2].

As this was a topic with very wide public interest, the progress of the campaign between mid-January and April 2016 was shared publicly as it happened on the Pale Red Dot website and via social media. The reports were accompanied by numerous outreach articles written by specialists around the world.

Guillem Anglada-Escudé explains the background to this unique search: "The first hints of a possible planet were spotted back in 2013, but the detection was not convincing. Since then we have worked hard to get further observations off the ground with help from ESO and others. The recent Pale Red Dot campaign has been about two years in the planning."

An angular size comparison of how Proxima will appear in the sky seen from Proxima b, compared to how the Sun appears in our sky on Earth. Proxima is much smaller than the Sun, but Proxima b lies very close to its star.

Credit: ESO/G. Coleman

The Pale Red Dot data, when combined with earlier observations made at ESO observatories and elsewhere, revealed the clear signal of a truly exciting result. At times Proxima Centauri is approaching Earth at about 5 kilometres per hour -- normal human walking pace -- and at times receding at the same speed. This regular pattern of changing radial velocities repeats with a period of 11.2 days. Careful analysis of the resulting tiny Doppler shifts showed that they indicated the presence of a planet with a mass at least 1.3 times that of the Earth, orbiting about 7 million kilometres from Proxima Centauri -- only 5% of the Earth-Sun distance [3].

Guillem Anglada-Escudé comments on the excitement of the last few months: "I kept checking the consistency of the signal every single day during the 60 nights of the Pale Red Dot campaign. The first 10 were promising, the first 20 were consistent with expectations, and at 30 days the result was pretty much definitive, so we started drafting the paper!"

Credit; ESO

Red dwarfs like Proxima Centauri are active stars and can vary in ways that would mimic the presence of a planet. To exclude this possibility the team also monitored the changing brightness of the star very carefully during the campaign using the ASH2 telescope at the San Pedro de Atacama Celestial Explorations Observatory in Chile and the Las Cumbres Observatory telescope network. Radial velocity data taken when the star was flaring were excluded from the final analysis.

Although Proxima b orbits much closer to its star than Mercury does to the Sun in the Solar System, the star itself is far fainter than the Sun. As a result Proxima b lies well within the habitable zone around the star and has an estimated surface temperature that would allow the presence of liquid water. Despite the temperate orbit of Proxima b, the conditions on the surface may be strongly affected by the ultraviolet and X-ray flares from the star -- far more intense than the Earth experiences from the Sun [4].


The relative sizes of a number of objects, including the three (known) members of Alpha Centauri triple system and some other stars for which the angular sizes have also been measured with the Very Large Telescope Interferometer (VLTI) at the ESO Paranal Observatory. The Sun and planet Jupiter are also shown for comparison.
Credit: ESO

Two separate papers discuss the habitability of Proxima b and its climate. They find that the existence of liquid water on the planet today cannot be ruled out and, in such case, it may be present over the surface of the planet only in the sunniest regions, either in an area in the hemisphere of the planet facing the star (synchronous rotation) or in a tropical belt (3:2 resonance rotation). Proxima b's rotation, the strong radiation from its star and the formation history of the planet makes its climate quite different from that of the Earth, and it is unlikely that Proxima b has seasons.

This image of the sky around the bright star Alpha Centauri AB also shows the much fainter red dwarf star, Proxima Centauri, the closest star to the Solar System. The picture was created from pictures forming part of the Digitized Sky Survey 2. The blue halo around Alpha Centauri AB is an artifact of the photographic process, the star is really pale yellow in colour like the Sun.

Credit: Digitized Sky Survey 2 Acknowledgement: Davide De Martin/Mahdi Zamani
This discovery will be the beginning of extensive further observations, both with current instruments [5] and with the next generation of giant telescopes such as the European Extremely Large Telescope (E-ELT). Proxima b will be a prime target for the hunt for evidence of life elsewhere in the Universe. Indeed, the Alpha Centauri system is also the target of humankind's first attempt to travel to another star system, the StarShot project.

Guillem Anglada-Escudé concludes: "Many exoplanets have been found and many more will be found, but searching for the closest potential Earth-analogue and succeeding has been the experience of a lifetime for all of us. Many people's stories and efforts have converged on this discovery. The result is also a tribute to all of them. The search for life on Proxima b comes next..."

This video shows an artist’s impression of a trip from Earth (the Pale Blue Dot) to Proxima b, a Pale Red Dot orbiting the closest star to the Solar System, Proxima Centauri. As we leave the Solar System we see the familiar constellation figures including the Southern Cross (Crux) and the bright stars Alpha and Beta Centauri. We gradually close in on a faint red star, this is Proxima Centauri, the closest star to Earth and the faintest component of a triple star system. The final part shows the planet Proxima b, the closest exoplanet to the Solar System.

Credit: ESO./L. Calçada/Nick Risinger (skysurvey.org)


On 24 August 2016 at 13:00 CEST, ESO hosted a press conference at its Headquarters in Garching, near Munich, Germany.

Credit: ESO/M. Kornmesser


Notes:
[1] Besides data from the recent Pale Red Dot campaign, the paper incorporates contributions from scientists who have been observing Proxima Centauri for many years. These include members of the original UVES/ESO M-dwarf programme (Martin Kürster and Michael Endl), and exoplanet search pioneers such as R. Paul Butler. Public observations from the HARPS/Geneva team obtained over many years were also included.

[2] The name Pale Red Dot reflects Carl Sagan's famous reference to the Earth as a pale blue dot. As Proxima Centauri is a red dwarf star it will bathe its orbiting planet in a pale red glow.

[3] The detection reported today has been technically possible for the last 10 years. In fact, signals with smaller amplitudes have been detected previously. However, stars are not smooth balls of gas and Proxima Centauri is an active star. The robust detection of Proxima b has only been possible after reaching a detailed understanding of how the star changes on timescales from minutes to a decade, and monitoring its brightness with photometric telescopes.

[4] The actual suitability of this kind of planet to support water and Earth-like life is a matter of intense but mostly theoretical debate. Major concerns that count against the presence of life are related to the closeness of the star. For example gravitational forces probably lock the same side of the planet in perpetual daylight, while the other side is in perpetual night. The planet's atmosphere might also slowly be evaporating or have more complex chemistry than Earth's due to stronger ultraviolet and X-ray radiation, especially during the first billion years of the star's life. However, none of the arguments has been proven conclusively and they are unlikely to be settled without direct observational evidence and characterisation of the planet's atmosphere. Similar factors apply to the planets recently found around TRAPPIST-1.

[5] Some methods to study a planet's atmosphere depend on it passing in front of its star and the starlight passing through the atmosphere on its way to Earth. Currently there is no evidence that Proxima b transits across the disc of its parent star, and the chances of this happening seem small, but further observations to check this possibility are in progress.

Octobot: Autonomous 3D Printed Untethered Soft Robot Uses No Electronics (Videos)

A team of Harvard University researchers with expertise in 3D printing, mechanical engineering, and microfluidics has demonstrated the first autonomous, untethered, entirely soft robot. This small, 3D-printed robot — nicknamed the octobot — could pave the way for a new generation of completely soft, autonomous machines as it uses no electronics.

Credit: SEAS

Soft robotics could revolutionize how humans interact with machines. But researchers have struggled to build entirely compliant robots. Electric power and control systems — such as batteries and circuit boards — are rigid and until now soft-bodied robots have been either tethered to an off-board system or rigged with hard components.

The octobot is powered by a chemical reaction and controlled with a soft logic board. A reaction inside the bot transforms a small amount of liquid fuel (hydrogen peroxide) into a large amount of gas, which flows into the octobot's arms and inflates them like a balloon. A microfluidic logic circuit, a soft analog of a simple electronic oscillator, controls when hydrogen peroxide decomposes to gas in the octobot.

Credit: Lori Sanders

Robert Wood, the Charles River Professor of Engineering and Applied Sciences and Jennifer A. Lewis, the Hansjorg Wyss Professor of Biologically Inspired Engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) led the research. Lewis and Wood are also core faculty members of the Wyss Institute for Biologically Inspired Engineering at Harvard University.


“One long-standing vision for the field of soft robotics has been to create robots that are entirely soft, but the struggle has always been in replacing rigid components like batteries and electronic controls with analogous soft systems and then putting it all together,” said Wood. “This research demonstrates that we can easily manufacture the key components of a simple, entirely soft robot, which lays the foundation for more complex designs.”

The research is described in the journal Nature.

“Through our hybrid assembly approach, we were able to 3D print each of the functional components required within the soft robot body, including the fuel storage, power and actuation, in a rapid manner,” said Lewis. “The octobot is a simple embodiment designed to demonstrate our integrated design and additive fabrication strategy for embedding autonomous functionality.”


The team used a microfluidic logic circuit, a soft analog of a simple electronic oscillator, to control when hydrogen peroxide decomposes to gas in the octobot.

Credit: Lori Sanders

Octopuses have long been a source of inspiration in soft robotics. These curious creatures can perform incredible feats of strength and dexterity with no internal skeleton.

Harvard’s octobot is pneumatic-based — powered by gas under pressure. A reaction inside the bot transforms a small amount of liquid fuel (hydrogen peroxide) into a large amount of gas, which flows into the octobot’s arms and inflates them like a balloon.


Credit: SEAS

“Fuel sources for soft robots have always relied on some type of rigid components,” said Michael Wehner, a postdoctoral fellow in the Wood lab and co-first author of the paper. “The wonderful thing about hydrogen peroxide is that a simple reaction between the chemical and a catalyst — in this case platinum — allows us to replace rigid power sources.”

To control the reaction, the team used a microfluidic logic circuit based on pioneering work by co-author and chemist George Whitesides, the Woodford L. and Ann A. Flowers University Professor and core faculty member of the Wyss. The circuit, a soft analog of a simple electronic oscillator, controls when hydrogen peroxide decomposes to gas in the octobot.

“The entire system is simple to fabricate, by combining three fabrication methods — soft lithography, molding and 3D printing — we can quickly manufacture these devices,” said Ryan Truby, a graduate student in the Lewis lab and co-first author of the paper.

The simplicity of the assembly process paves the way for more complex designs. Next, the Harvard team hopes to design an octobot that can crawl, swim and interact with its environment.

“This research is a proof of concept,” Truby said. “We hope that our approach for creating autonomous soft robots inspires roboticists, material scientists and researchers focused on advanced manufacturing,”

The paper was co-authored by Daniel Fitzgerald of the Wyss Institute and Bobak Mosadegh, of Cornell University. The research was supported by the National Science Foundation through the Materials Research Science and Engineering Center at Harvard and by the Wyss Institute.

Visit the new Harvard Robotics website to learn more about robotics at Harvard.




Contacts and sources:
Leah Burrows
Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS)

‘Ouchless’ Insulin Pill Made for Diabetes Treatment

Every day, millions of Americans with diabetes have to inject themselves with insulin to manage their blood-sugar levels. But less painful alternatives are emerging. Scientists are developing a new way of administering the medicine orally with tiny vesicles that can deliver insulin where it needs to go without a shot. Today, they share their in vivo testing results.

“We have developed a new technology called a CholestosomeTM,” says Mary McCourt, Ph.D., a leader of the research team. “A CholestosomeTM is a neutral, lipid-based particle that is capable of doing some very interesting things.”

The biggest obstacle to delivering insulin orally is ushering it through the stomach intact. Proteins such as insulin are no match for the harsh, highly acidic environment of the stomach. They degrade before they get a chance to move into the intestines and then the bloodstream where they’re needed.

A pill could one day simplify diabetes treatments.
Credit: MihaPater/iStock/Thinkstock


Some efforts have been made to overcome or sidestep this barrier. One approach packages insulin inside a protective polymer coating to shield the protein from stomach acids and is being tested in clinical trials. Another company developed and marketed inhalable insulin, but despite rave reviews from some patients, sales were a flop. Now its future is uncertain.

McCourt, Lawrence Mielnicki, Ph.D., and undergraduate student Jamie Catalano — all from Niagara University — have a new tactic. Using the patented CholestosomesTM developed in the McCourt/Mielnicki lab, the researchers have successfully encapsulated insulin. The novel vesicles are made of naturally occurring lipid molecules, which are normal building blocks of fats. But the researchers say that they are unlike other lipid-based drug carriers, called liposomes.



“Most liposomes need to be packaged in a polymer coating for protection,” says Mielnicki. “Here, we’re just using simple lipid esters to make vesicles with the drug molecules inside.”

Computer modeling showed that once the lipids are assembled into spheres, they form neutral particles resistant to attack from stomach acids. Drugs can be loaded inside, and the tiny packages can pass through the stomach without degrading. When CholestosomesTM reach the intestines, the body recognizes them as something to be absorbed. The vesicles pass through the intestines, into the bloodstream, and then cells take them in and break them apart, releasing insulin.

The team has delivered multiple molecules with these vesicles into cells in the lab. To pack the most insulin into the CholestosomesTM, the researchers determined the optimal pH and ionic strength of the drug-containing solution. They then moved the most promising candidates on to animal testing. Studies with rats showed that certain formulations of CholestosomesTM loaded with insulin have high bioavailability, which means the vesicles travel into the bloodstream where the insulin needs to be.

Next, the team plans to further optimize the formulations, conduct more animal testing and develop new partnerships to move forward into human trials.

The researchers presented their work at the 252nd National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through Agust 25th.  It features more than 9,000 presentations on a wide range of science topics.

The researchers acknowledge funding from Niagara University, CPL Associatesand Theraholdings A.G.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.




Contacts and sources:
Michael Bernstein
Katie Cottingham, Ph.D.
American Chemical Society (ACS)

Beetles Pollinated Orchids Millions of Year Ago, Fossil Evidence Shows

When most people hear the word "pollinator," they think of bees and butterflies. However, certain beetles are known to pollinate plants as well, and new fossil evidence indicates that they were doing so 20 million years ago.

A new study in American Entomologist by George Poinar, Jr. (Oregon State University) describes beetles found in fossilized amber with orchid pollen in their mouthparts.

"My paper points out that beetles may play a more important role in pollinating orchids than originally thought, and that they have been doing so for some 20 million years," Poinar said.

This is a fossil ptilodactyline beetle found in amber from Mexico. The black arrow points to pollinia attached to the beetle's mouthparts.

Credit: Entomological Society of America

Some present-day beetles use orchids for nectar, but no fossil evidence has ever been found showing beetles in the evolutionary past pollinating orchids -- until now.

The first specimen was a hidden-snout beetle (subfamily Cryptorhynchinae) found in amber from the Dominican Republic. This Dominican specimen had pollinaria from an orchid described as Cylindrocites browni attached to its thorax. The other specimen was a toe-winged beetle (family Ptilodactylidae) that was found in amber from Mexico. This toe-winged beetle had pollinaria from an orchid described as Annulites mexicana attached to its mouthparts.

The beetle in Dominican amber was estimated to be from 20 to 45 million years old, and the beetle in Mexican amber was in strata estimated to be from 22 to 26 million years old.

While other beetles are known to pollinate plants, no current-day hidden-snout beetles have been seen visiting orchid plants, and no current-day toe-winged beetles have been seen with pollinaria.

According to Poinar, the reason may lie in the beetles' secretive behavior, which makes it difficult to collect data about them.

"While no present-day cryptorhynchid weevils or ptilodactyline beetles are known to carry pollinaria, past and future collections of these and other beetles should be examined to search for attached pollinaria," Poinar said. "Orchids may have evolved beneficial associations with a much wider range of beetles and other insects than we thought possible."



Contacts and sources:
Richard Levine
Entomological Society of America, 


Citation: "Beetles with Orchid Pollinaria in Dominican and Mexican Amber," is available at http://ae.oxfordjournals.org/lookup/doi/10.1093/ae/tmw055.

Selecting The Right House Plant Can Improve Indoor Air (Animation)

Indoor air pollution is an important environmental threat to human health, leading to symptoms of “sick building syndrome.” But researchers report that surrounding oneself with certain house plants could combat the potentially harmful effects of volatile organic compounds (VOCs), a main category of these pollutants. Interestingly, they found that certain plants are better at removing particular harmful compounds from the air, suggesting that, with the right plant, indoor air could become cleaner and safer.

“Buildings, whether new or old, can have high levels of VOCs in them, sometimes so high that you can smell them,” says Vadoud Niri, Ph.D., leader of the study.

VOCs are compounds like acetone, benzene and formaldehyde that are emitted as gases and can cause short- and long-term health effects when inhaled. They can come from paints, furniture, copiers and printers, cleaning supplies and even dry-cleaned clothes.

Bromeliad plants are good at removing a wide variety of VOCs from the air.
Courtesy of Vadoud Niri

“Inhaling large amounts of VOCs can lead some people to develop sick building syndrome, which reduces productivity and can even cause dizziness, asthma or allergies,” Niri says. “We must do something about VOCs in indoor air.”

The most common solution is to install ventilation systems that cycle in air from outside. There are also methods that can remove these compounds, using adsorption, condensation and chemical reactions.


Credit: American Chemical Society

However, Niri is studying a cheap, simple tool to remove VOCs: house plants. Using plants to remove chemicals from indoor air is called biofiltration or phytoremediation. In addition to carbon dioxide, plants can take up gases such as benzene, toluene and other VOCs. NASA began studying this option in 1984 and found that plants could absorb these airborne compounds via their leaves and roots.

Since then, other studies have looked at how plants phytoremediate specific compounds, such as the carcinogen formaldehyde, in a closed space. Most of these studies focused on the removal of single VOCs by individual plants from the ambient air. However, Niri wanted to compare the efficiency and the rate of simultaneous removal of several VOCs by various plants.

To test this, Niri, who is at the State University of New York at Oswego (SUNY Oswego), and his team built a sealed chamber containing specific concentrations of several VOCs. They then monitored the VOC concentrations over several hours with and without a different type of plant in the chamber. For each plant type, they noted which VOCs the plants took up, how quickly they removed these VOCs from the air, and how much of the VOCs were ultimately removed by the end of the experiment.

The researchers tested five common house plants and eight common VOCs, and they found that certain plants were better at absorbing specific compounds. For example, all five plants could remove acetone — the pungent chemical that is abundant at nail salons — from the air, but the dracaena plant took up the most, around 94 percent of the chemical.

“Based on our results, we can recommend what plants are good for certain types of VOCs and for specific locations,” Niri says. “To illustrate, the bromeliad plant was very good at removing six out of eight studied VOCs — it was able to take up more than 80 percent of each of those compounds — over the twelve-hour sampling period. So it could be a good plant to have sitting around in the household or workplace.”



Niri says the next step in the research is to test these plants’ abilities in a real room, not just a sealed chamber. He would eventually like to put plants in a nail salon over the course of several months to see whether they can reduce the levels of acetone that workers are exposed to.

The researchers presented their work August 24th at the 252nd National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through August 25th

He acknowledges funding from SUNY Oswego’s Scholarly and Creative Activity Grants.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.





Contacts and sources:
Michael Bernstein
Katie Cottingham, Ph.D.
American Chemical Society (ACS)

New Global Migration Mapping Helps Fight Against Infectious Diseases

Geographers at the University of Southampton have completed a large scale data and mapping project to track the flow of internal human migration in low and middle income countries.

Researchers from the WorldPop project at the University have, for the first time, mapped estimated internal migration in countries across three continents; Africa, Asia and Latin America and the Caribbean.

Professor Andy Tatem, Director of WorldPop, comments: "Understanding how people are moving around within countries is vital in combating infectious diseases like malaria. The parasite which causes the disease can be quickly reintroduced to a malaria free area by highly mobile populations.

Estimated internal human migration flows between subnational administrative units for every malaria endemic country in Africa.
Credit:World Pop

"Having an accurate overview of how different regions of countries are connected by human movement aids effective disease control planning and helps target resources, such as treated bed nets or community health workers, in the right places. Having data for all low and middle income countries across three continents will greatly aid disease control and elimination planning on global and regional scales."

Working with colleagues at the Flowminder Foundation and supported by the Bill and Melinda Gates Foundation, the researchers have used census micro-data (anonymised census information at the individual level) to model estimates of migration flows within countries and then produced a series of maps to visually represent the data. The research paper 'Mapping internal connectivity through human migration in malaria endemic countries' published inScientific Data details the methods they employed, and presents the freely available data.

Lead author Dr Alessandro Sorichetta from the University of Southampton says: "We sourced the census data from around 40 different countries and have produced detailed population migration maps on a scale not seen before. They show webs of connectivity within countries -- indicating high and low flows of people moving between different locations."

Migration Map of Dominican Republic
Credit:World Pop

Figures from the International Organization for Migration and The World Bank show that, without accounting for seasonal and temporary migrants, more than one billion people live outside their place of origin -- 740 million as 'internal migrants'. Human mobility is expected to continue to rise, creating a range of impacts, such as invasive species, drug resistance spread and disease pandemics.

Dr Sorichetta comments: "It's crucial we understand human mobility, so we can quantify the effect it has on our societies and the environment and provide strong evidence to support the development of policies to address issues, such as public health problems."

The researchers are now integrating the migration estimates with data on malaria prevalence - helping to inform regional elimination and global eradication plans for the disease. Equally, they believe the data could be used to support regional control and elimination strategies for other infectious diseases, for example, Schistosomiasis, River Blindness, HIV, dengue and Yellow Fever. Furthermore, the datasets could help inform decisions in the fields of trade, demography, transportation and economics.



Contacts and sources:
Glenn Harris
University of Southampton

Chimpanzees Choose Cooperation over Competition

When given a choice between cooperating or competing, chimpanzees choose to cooperate five times more frequently, Yerkes National Primate Research Center researchers have found. This, the researchers say, challenges the perceptions humans are unique in our ability to cooperate and chimpanzees are overly competitive, and suggests the roots of human cooperation are shared with other primates.

Chimpanzee cooperation task. All chimpanzees must manipulate the handles at the same time in order for the food to be delivered. Video from Yerkes National Primate Research Center.


The study results are reported in this week’s early online edition of the Proceedings of the National Academy of Sciences.

To determine if chimpanzees possess the same ability humans have to overcome competition, the researchers set up a cooperative task that closely mimicked chimpanzee natural conditions, for example, providing the 11 great apes that voluntarily participated in this study with an open choice to select cooperation partners and giving them plenty of ways to compete. 


Working beside the chimpanzees’ grassy outdoor enclosure at the Yerkes Research Center Field Station, the researchers gave the great apes thousands of opportunities to pull cooperatively at an apparatus filled with rewards. In half of the test sessions, two chimpanzees needed to participate to succeed, and in the other half, three chimpanzees were needed.

While the set up provided ample opportunities for competition, aggression and freeloading, the chimpanzees overwhelmingly performed cooperative acts – 3,565 times across 94 hour-long test sessions.

The chimpanzees used a variety of enforcement strategies to overcome competition, displacement and freeloading, which the researchers measured by attempted thefts of rewards. These strategies included the chimpanzees directly protesting against others, refusing to work in the presence of a freeloader, which supports avoidance as an important component in managing competitive tendencies, and more dominant chimpanzees intervening to help others against freeloaders. Such third-party punishment occurred 14 times, primarily in response to aggression between the freeloader and the chimpanzee that was cooperatively working with others for the rewards.



“Previous statements in the literature describe human cooperation as a ‘huge anomaly’ and chimpanzees as preferring competition over collaboration,” says Malini Suchak, PhD, lead author of the study. “Studies have also suggested researchers have to ‘engineer cooperation’ during experiments rather than acknowledging chimpanzees are naturally cooperative. When we considered chimpanzees’ natural behaviors, we thought surely they must be able to manage competition on their own, so we gave them the freedom to employ their own enforcement strategies. And it turns out, they are really quite good at preventing competition and favoring cooperation.

 In fact, given the ratio of conflict to cooperation is quite similar in humans and chimpanzees, our study shows striking similarities across species and gives another insight into human evolution,” she continues. Suchak was a graduate student at the Yerkes Research Center at the time of this 2011-12 study and is now an Assistant Professor of Animal Behavior, Ecology and Conservation at Canisius College in Buffalo, NY.

Frans de Waal, PhD, director of the Living Links Center at the Yerkes Research Center, a C. H. Candler Professor of Psychology at Emory University and one of the study authors, adds, "It has become a popular claim in the literature that human cooperation is unique. This is especially curious because the best ideas we have about the evolution of cooperation come straight from animal studies. The natural world is full of cooperation, from ants to killer whales. Our study is the first to show that our closest relatives know very well how to discourage competition and freeloading. Cooperation wins!”

This study was supported by: the Living Links Center of the Yerkes National Primate Research Center; the National Institutes of Health’s Office of Research Infrastructure Programs base grant to the Yerkes National Primate Research Center - P51OD011132; Emory University’s PRISM Program (NSF GK12 #DGE0536941); Emory's Dean’s Teaching Fellowship Program; Emory’s FIRST Program (NIH/NIGMS {USA}) IRACDA grant #K12GM00680 to co-author Matt Campbell, PhD; the Expanding the Science and Practice of Gratitude Project the Greater Good Science Center runs in partnership with UC Berkeley with funding from the John Templeton Foundation; and the Canisius Earning Excellence Program.

Yerkes National Primate Research Center

Established in 1930, the Yerkes National Primate Research Center paved the way for what has become the National Institutes of Health-funded National Primate Research Center (NPRC) program. For more than eight decades, the Yerkes Research Center has been dedicated to conducting essential basic science and translational research to advance scientific understanding and to improve human health and well-being. Today, the Yerkes Research Center is one of only seven NPRCs. The center provides leadership, training and resources to foster scientific creativity, collaboration and discoveries, and research at the center is grounded in scientific integrity, expert knowledge, respect for colleagues, an open exchange of ideas and compassionate, quality animal care.

In the fields of microbiology and immunology, infectious diseases, pharmacology and drug discovery, transplantation, neurologic and psychiatric diseases, as well as behavioral, cognitive and developmental neuroscience, Yerkes scientists use innovative experimental models and cutting-edge technologies to explore and test transformative concepts aimed at: preventing and treating viral diseases such as AIDS; designing novel vaccines for infectious diseases such as malaria and tuberculosis; enhancing the potential of organ transplantation and regenerative medicine; discovering new drugs and drug classes through high-throughput screening; defining the basic neurobiology and genetics of social behavior and developing new therapies for disorders such as autism and drug addiction; understanding the biology of neurodegenerative diseases, such as Alzheimer’s and Parkinson’s diseases; and advancing knowledge about the evolutionary links between biology and behavior.



Contacts and sources:
Lisa Newbern
Woodruff Health Sciences Center
Emory Health Sciences



Citation: How chimpanzees cooperate in a competitive world  http://www.pnas.org/content/early/2016/08/16/1611826113

Tuesday, August 23, 2016

Nanoparticles Can Save Lives by Speeding Blood Clotting

Whether severe trauma occurs on the battlefield or the highway, saving lives often comes down to stopping the bleeding as quickly as possible. Many methods for controlling external bleeding exist, but at this point, only surgery can halt blood loss inside the body from injury to internal organs. Now, researchers have developed nanoparticles that congregate wherever injury occurs in the body to help it form blood clots, and they’ve validated these particles in test tubes and in vivo. 

“When you have uncontrolled internal bleeding, that’s when these particles could really make a difference,” says Erin B. Lavik, Sc.D. “Compared to injuries that aren’t treated with the nanoparticles, we can cut bleeding time in half and reduce total blood loss.”

Trauma remains a top killer of children and younger adults, and doctors have few options for treating internal bleeding. To address this great need, Lavik’s team developed a nanoparticle that acts as a bridge, binding to activated platelets and helping them join together to form clots. To do this, the nanoparticle is decorated with a molecule that sticks to a glycoprotein found only on the activated platelets.

Nanoparticles (green) help form clots in an injured liver. The researchers added color to the scanning electron microscopy image after it was taken.

Credit: Erin Lavik, Ph.D.


Initial studies suggested that the nanoparticles, delivered intravenously, helped keep rodents from bleeding out due to brain and spinal injury, Lavik says. But, she acknowledges, there was still one key question: “If you are a rodent, we can save your life, but will it be safe for humans?”

As a step toward assessing whether their approach would be safe in humans, they tested the immune response toward the particles in pig’s blood. If a treatment triggers an immune response, it would indicate that the body is mounting a defense against the nanoparticle and that side effects are likely. The team added their nanoparticles to pig’s blood and watched for an uptick in complement, a key indicator of immune activation. The particles triggered complement in this experiment, so the researchers set out to engineer around the problem.


Credit: American Chemical Society (ACS)

“We made a battery of particles with different charges and tested to see which ones didn’t have this immune-response effect,” Lavik explains. “The best ones had a neutral charge.” But neutral nanoparticles had their own problems. Without repulsive charge-charge interactions, the nanoparticles have a propensity to aggregate even before being injected. To fix this issue, the researchers tweaked their nanoparticle storage solution, adding a slippery polymer to keep the nanoparticles from sticking to each other.

Lavik also developed nanoparticles that are stable at higher temperatures, up to 50 degrees Celsius (122 degrees Fahrenheit). This would allow the particles to be stored in a hot ambulance or on a sweltering battlefield.

In future studies, the researchers will test whether the new particles activate complement in human blood. Lavik also plans to identify additional critical safety studies they can perform to move the research forward. For example, the team needs to be sure that the nanoparticles do not cause non-specific clotting, which could lead to a stroke. Lavik is hopeful though that they could develop a useful clinical product in the next five to 10 years.

The researchers presented their work August 22nd at the 252nd National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through August 25th. It features more than 9,000 presentations on a wide range of science topics.

Lavik acknowledges funding from the National Institutes of Health and the U.S. Department of Defense.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.



Contacts and sources:
Michael Bernstein
Katie Cottingham, Ph.D.
American Chemical Society (ACS)

By Focusing On Cold Starts Cars Could Meet Future Emissions Standards (Video)

Car emissions is a high-stakes issue, as last year’s Volkswagen scandal demonstrated. Pressure to meet tightening standards led the carmaker to cheat on emissions tests. But wrongdoing aside, how are automakers going to realistically meet future, tougher emissions requirements to reduce their impact on the climate? Researchers report today that a vehicle’s cold start — at least in gasoline-powered cars — is the best target for future design changes.

“The main goal of our project was to find out how effective regulations of gasoline vehicle emissions have been at reducing the formation of smog,” says Greg Drozd, Ph.D. “It was also a very forward-thinking study in anticipation of how cars that meet future emissions standards will lead to reductions in air pollution.”

Tailpipe emissions are highest in the first 30 seconds to one minute of a cold start.
Credit: Wikipedia

Although the Environmental Protection Agency (EPA) has reported that air is cleaner today than it was in the 1970s, more than 130 million people in the U.S. still live in places where smog or particle pollution rises to unhealthful levels. Smog can cause coughing and shortness of breath, and can aggravate asthma or trigger asthma attacks. Much of this haze is formed from volatile organic compounds, or VOCs, and fine particulate matter from tailpipe emissions.

To find out what vehicles on the road are currently emitting, Drozd and colleagues at the University of California, Berkeley; Carnegie Mellon University; the University of California, San Diego; and the Massachusetts Institute of Technology rented 25 gasoline-powered cars, including two hybrids, from residents in the Los Angeles area. The vehicle ages ranged from 2 to 20 years.

Credit: American Chemical Society (ACS)

The researchers took the cars to the Haagen-Smit Laboratory funded by the California Air Resources Board and drove them on a giant treadmill. Using a proton-transfer reaction mass spectrometer, they were able to measure a wider range of compounds coming out of tailpipes more rapidly than in previous reports. They detected a cocktail of chemicals, including fuel components such as benzene, toluene and xylenes, and incomplete combustion products including acetaldehyde, formaldehyde and acetonitrile. But overall, their concentrations were very low for the newer cars.

“The clearest result was how effective emissions controls have become for organic gases,” Drozd says. “New vehicles less than 2 years old emitted as little as 1 percent of the total amount of organic gases that a 20-year-old vehicle emitted. Very few studies have tested new cars for these gases.”

The researchers also found that almost all emissions in properly functioning, new vehicles came out immediately after starting the cars when their engines were cold. But once new cars warmed up, they had to be driven 100 to 300 miles to match the levels that came out in the first 30 seconds of the engine turning on.

“Our work shows that for newer cars we should have fast measurements, so that we can then more accurately predict emissions from cars in the real world,” Drozd says.

Even malfunctioning and older cars would have to travel 50 to 100 miles, respectively, to release the same amount of emissions as they would within the first minute of a cold start, he adds. This concentrated release very early in a car’s operation occurs because its catalytic converter, which breaks down VOCs, hasn’t had a chance to warm up yet. The faster it can heat up, the lower the emissions could be, he explains.

“That tells us how we need to inform future vehicle engineering,” Drozd says. “We need to think a lot about that cold start. That’s still the best place to reduce emissions.”

The researchers’ findings could also help the EPA model future emissions standards as the U.S. works to lower them.

The researchers presented their work August 22nd at the 252nd National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through August 25th. It features more than 9,000 presentations on a wide range of science topics.

Drozd acknowledges funding from the California Air Resources Board.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.




Contacts and sources:
Michael Bernstein
Katie Cottingham, Ph.D.
American Chemical Society (ACS)

Stretchable Supercapacitors Power Smart Wearable Electronics That Can Power Other Gadgets

A future of soft robots that wash your dishes or smart T-shirts that power your cell phone may depend on the development of stretchy power sources. But traditional batteries are thick and rigid — not ideal properties for materials that would be used in tiny malleable devices. In a step toward wearable electronics, a team of researchers has produced a stretchy micro-supercapacitor using ribbons of graphene.

“Most power sources, such as phone batteries, are not stretchable. They are very rigid,” says Xiaodong Chen, Ph.D. “My team has made stretchable electrodes, and we have integrated them into a supercapacitor, which is an energy storage device that powers electronic gadgets.”

This stretchy supercapacitor made from graphene could spur the development of wearable electronics.
Credit: Xiaodong Chen, Ph.D. 


Supercapacitors, developed in the 1950s, have a higher power density and longer life cycle than standard capacitors or batteries. And as devices have shrunk, so too have supercapacitors, bringing into the fore a generation of two-dimensional micro-supercapacitors that are integrated into cell phones, computers and other devices. However, these supercapacitors have remained rigid, and are thus a poor fit for soft materials that need to have the ability to elongate.

In this study, Chen of Nanyang Technological University, Singapore, and his team sought to develop a micro-supercapacitor from graphene. This carbon sheet is renowned for its thinness, strength and conductivity. “Graphene can be flexible and foldable, but it cannot be stretched,” he says. To fix that, Chen's team took a cue from skin. Skin has a wave-like microstructure, Chen says. “We started to think of how we could make graphene more like a wave.”

The researchers’ first step was to make graphene micro-ribbons. Most graphene is produced with physical methods — like shaving the tip of a pencil — but Chen uses chemistry to build his material. “We have more control over the graphene’s structure and thickness that way,” he explains. “It’s very difficult to control that with the physical approach. Thickness can really affect the conductivity of the electrodes and how much energy the supercapacitor overall can hold.”

The next step was to create the stretchable polymer chip with a series of pyramidal ridges. The researchers placed the graphene ribbons across the ridges, creating the wave-like structure. The design allowed the material to stretch without the graphene electrodes of the superconductor detaching, cracking or deforming. In addition, the team developed kirigami structures, which are variations of origami folds, to make the supercapacitors 500 percent more flexible without decaying their electrochemical performance. As a final test, Chen has powered an LCD from a calculator with the stretchy graphene-based micro-supercapacitor. Similarly, such stretchy supercapacitors can be used in pressure or chemical sensors.

In future experiments, the researchers hope to increase the electrode’s surface area so it can hold even more energy. The current version only stores enough energy to power LCD devices for a minute, he says.

The researchers presented their work August 23rd at the 252nd National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through August 25th. It features more than 9,000 presentations on a wide range of science topics.

Chen acknowledges funding from the National Research Foundation, Prime Minister’s Office, Singapore, under its Campus for Research Excellence and Technological Enterprise (CREATE) Programme of Nanomaterials for Energy and Water Management.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.



Contacts and sources:
Michael Bernstein
Katie Cottingham, Ph.D.
American Chemical Society (ACS)

Edible Battery To Power Ingestible Devices for Diagnosing and Treating Diseases

Non-toxic, edible batteries could one day power ingestible devices for diagnosing and treating disease. One team reports new progress toward that goal with their batteries made with melanin pigments, naturally found in the skin, hair and eyes.

“For decades, people have been envisioning that one day, we would have edible electronic devices to diagnose or treat disease,” says Christopher Bettinger, Ph.D. “But if you want to take a device every day, you have to think about toxicity issues. That’s when we have to think about biologically derived materials that could replace some of these things you might find in a RadioShack.”

Christopher Bettinger, Ph.D., is developing an edible battery made with melanin and dissolvable materials.

Courtesy of: Bettinger lab 

About 20 years ago, scientists did develop a battery-operated ingestible camera as a complementary tool to endoscopies. It can image places in the digestive system that are inaccessible to the traditional endoscope. But it is designed to pass through the body and be excreted. For a single use, the risk that the camera with a conventional battery will get stuck in the gastrointestinal tract is small. But the chances of something going wrong would increase unacceptably if doctors wanted to use it more frequently on a single patient.

The camera and some implantable devices such as pacemakers run on batteries containing toxic components that are sequestered away from contact with the body. But for low-power, repeat applications such as drug-delivery devices that are meant to be swallowed, non-toxic and degradable batteries would be ideal.

“The beauty is that by definition an ingestible, degradable device is in the body for no longer than 20 hours or so,” Bettinger says. “Even if you have marginal performance, which we do, that’s all you need.”

Credit: American Chemical Society (ACS)

While he doesn’t have to worry about longevity, toxicity is an issue. To minimize the potential harm of future ingestible devices, Bettinger’s team at Carnegie Mellon University (CMU) decided to turn to melanins and other naturally occurring compounds. In our skin, hair and eyes, melanins absorb ultraviolet light to quench free radicals and protect us from damage. They also happen to bind and unbind metallic ions. “We thought, this is basically a battery,” Bettinger says.

Building on this idea, the researchers experimented with battery designs that use melanin pigments at either the positive or negative terminals; various electrode materials such as manganese oxide and sodium titanium phosphate; and cations such as copper and iron that the body uses for normal functioning.

“We found basically that they work,” says Hang-Ah Park, Ph.D., a post-doctoral researcher at CMU. “The exact numbers depend on the configuration, but as an example, we can power a 5 milliWatt device for up to 18 hours using 600 milligrams of active melanin material as a cathode.”

Although the capacity of a melanin battery is low relative to lithium-ion, it would be high enough to power an ingestible drug-delivery or sensing device. For example, Bettinger envisions using his group’s battery for sensing gut microbiome changes and responding with a release of medicine, or for delivering bursts of a vaccine over several hours before degrading.

In parallel with the melanin batteries, the team is also making edible batteries with other biomaterials such as pectin, a natural compound from plants used as a gelling agent in jams and jellies. Next, they plan on developing packaging materials that will safely deliver the battery to the stomach.

When these batteries will be incorporated into biomedical devices is uncertain, but Bettinger has already found another application for them. His lab uses the batteries to probe the structure and chemistry of the melanin pigments themselves to better understand how they work.

The researchers presented their work August 23rd at the 252nd National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through August 25th. It features more than 9,000 presentations on a wide range of science topics.

Bettinger acknowledges funding from the National Science Foundation and theShurl and Kay Curci Foundation.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.




Contacts and sources:
Michael Bernstein
Katie Cottingham, Ph.D.
American Chemical Society (ACS)

Using Completely Degradable, Synthetic Rubber Could Reduce Tire Waste (Video)

Scrap tires have been on environmentalists’ blacklist for decades. They pile up in landfills, have fed enormous toxic fires, harbor pests and get burned for fuel. Scientists trying to rid us of this scourge have developed a new way to make synthetic rubber. And once this material is discarded, it can be easily degraded back to its chemical building blocks and reused in new tires and other products.

“The basic idea behind this project was to take a byproduct of the petrochemical industry and turn some of it into recyclable value-added chemicals for use in tires and other applications,” says Robert Tuba, Ph.D., one of the lead researchers on the project. “We want to make something that is good for the community and the environment.”

Credit: American Chemical Society

According to the Rubber Manufacturers Association, nearly 270 million tires were discarded in the U.S. in 2013 — more than one tire per adult living in the country. Thousands get stockpiled in landfills. And because tires are non-degradable, they could potentially stick around indefinitely. More than half go on to become tire-derived fuel — shredded scrap tires that get mixed with coal and other materials to help power cement kilns, pulp and paper mills and other plants. But environmentalists are concerned that the emissions from this practice could be adding harmful pollutants to the air.

One possible solution to the nation’s scrap-tire glut would be to make new tires with degradable materials. Since 2012, the research team led by Hassan S. Bazzi, Ph.D., at the Texas A&M University campus in Qatar (TAMU-Qatar) has been working on this option. They started with a basic molecule called cyclopentene. Cyclopentene and its precursor cyclopentadiene are low-value major components of the abundant waste from petrochemical refining, in particular its steam-cracking operation C5 fraction, which contains hydrocarbons with five carbon atoms. With colleagues at the California Institute of Technology, they have been experimenting with catalysts to string cyclopentene molecules together to make polypentenamers, which are similar to natural rubber.

Currently, synthetic-rubber makers use butadiene as their base material, but its cost has recently gone up, opening the door to competition. So Tuba turned to cyclopentene as a potential alternative. Calculations showed that polymerizing cyclopentene and degrading it under relatively mild reaction conditions — and thus requiring minimal energy and expense — should be possible.


Credit: American Chemical Society

“We did theoretical studies to predict the feasibility of the synthesis and recyclability of polypentenamer-based tire additives using equilibrium ring opening metathesis polymerization,” explains Antisar Hlil, also at TAMU-Qatar. “Then we did experimental studies and found that the concept works very well.”

Using ruthenium, a transition-metal catalyst, the researchers polymerized cyclopentene at 0 degrees Celsius and decomposed the resulting material at 40 to 50 degrees. For industry, these are low temperatures that do not require a lot of energy. Additionally, in the lab, they could recover 100 percent of their starting material from several polypentenamer-based tire additives they developed.

In progress are new studies that mix the synthetic rubber with other tire materials, which include metals and fillers. The researchers are also scaling up their lab experiments to see whether the tire industry could realistically use their processes.

“If the fundamental studies are very promising — which at this point, we believe they are — then our industry partner will come in to continue this project and bring the material to market,” Tuba says.

The researchers presented their work August 22nd at the 252nd National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through August 25th. It features more than 9,000 presentations on a wide range of science topics.

The researchers acknowledge funding from the Qatar Foundation and the Qatar National Research Fund.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.



Contacts and sources:
Michael Bernstein
Katie Cottingham, Ph.D.
American Chemical Society (ACS)

Nanotechnology: 'Ideal' Energy Storage Material for Electric Vehicles Advanced

The energy-storage goal of a polymer dielectric material with high energy density, high power density and excellent charge-discharge efficiency for electric and hybrid vehicle use has been achieved by a team of Penn State materials scientists. The key is a unique three-dimensional sandwich-like structure that protects the dense electric field in the polymer/ceramic composite from dielectric breakdown.

“Polymers are ideal for energy storage for transportation due to their light weight, scalability and high dielectric strength,” says Qing Wang, professor of materials science and engineering and the team leader. “However, the existing commercial polymer used in hybrid and electric vehicles, called BOPP, cannot stand up to the high operating temperatures without considerable additional cooling equipment. This adds to the weight and expense of the vehicles.”

Boron nitride nanosheets (blue and white atoms) act as insulators to protect a barium nitrate central layer (green and purple atoms) for high temperature energy storage.


Image: Wang Lab/Penn State

The researchers had to overcome two problems to achieve their goal. In normal two-dimensional polymer films such as BOPP, increasing the dielectric constant, the strength of the electric field, is in conflict with stability and charge-discharge efficiency. The stronger the field, the more likely a material is to leak energy in the form of heat. The Penn State researchers originally attacked this problem by mixing different materials while trying to balance competing properties in a two-dimensional form. While this increased the energy capacity, they found that the film broke down at high temperatures when electrons escaped the electrodes and were injected into the polymer, which caused an electric current to form.

“That’s why we developed this sandwich structure,” Wang says. “We have the top and bottom layers that block charge injection from the electrodes. Then in the central layer we can put all of the high dielectric constant ceramic/polymer filler material that improves the energy and power density.”

The outer layers, composed of boron nitride nanosheets in a polymer matrix, are excellent insulators, while the central layer is a high dielectric constant material called barium titanate.

“We show that we can operate this material at high temperature for 24 hours straight over more than 30,000 cycles and it shows no degradation,” Wang says.
Comparison to BOPP

A comparison of BOPP and the sandwich structure nanocomposite, termed SSN-x, in which the x refers to the percentage of barium titanate nanocomposites in the central layer, shows that at 150 degrees C, SSN-x has essentially the same charge-discharge energy as BOPP at it typical operating temperature of 70 degrees C. However, SSN-x has several times the energy density of BOPP, which makes SSN-x highly preferable for electric vehicle and aerospace applications as an energy storage device due to the ability to reduce the size and weight of the electronics significantly while improving system performance and stability. The elimination of bulky and expensive cooling equipment required for BOPP is an additional bonus.

“Our next step is to work with a company or with more resources to do processability studies to see if the material can be produced at a larger scale at a reasonable cost,” Wang says. “We have demonstrated the materials performance in the lab. We are developing a number of state-of-the-art materials working with our theory colleague Long-Qing Chen in our department. Because we are dealing with a three-dimensional space, it is not just selecting the materials, but how we organize the multiple nanosized materials in specific locations. Theory helps us design materials in a rational fashion.”

Their results were published on August 22nd in the Proceedings of the National Academy of Sciences (PNAS).

In addition to Professors Wang and Chen, contributors to the paper, titled “Sandwich-Structured Polymer Nanocomposites with High Energy Density and Great Charge-Discharge Efficiency at Elevated Temperatures,” include first author and post-doctoral scholar Qi Li, Ph.D. student Feihua Liu, Matthew Gadinski, a former Ph.D. student now at DOW Chemical, Guangzu Zhang, a post-doctoral scholar, all in Wang’s lab, and Tiannan Yang, a graduate student in Chen’s group.

This work was supported by the US Office of Naval Research.



Contacts and sources:
by Walt Mills
Penn State University

Spidey Sense: Hibernating Animals Can Sense Danger While Dormant


What happens to hibernating or torpid animals when a bushfire rages? Are they able to sense danger and wake up from their energy-saving sleep to move to safety? Yes, says Julia Nowack of the University of New England in Australia, lead author of a study in Springer's journal The Science of Nature about the reaction of pygmy-possums in such instances. The study is the first to investigate in detail the physical response of hibernating animals to smoke and fire.

Pygmy-possums (Cercartetus nanus) live in trees mainly along the south-east coast of Australia. These small and agile nocturnal marsupials use their tails to grasp onto branches while moving about, and are even able to climb up their own tails.

Pygmy-possum.

Credit: Gerhard Koertner

Nowack's team conducted tests under laboratory conditions on five eastern pygmy-possums while they were experiencing torpor. During this state of inactivity and metabolic rest, the animals do not need food, their body temperatures drop and they experience periods of deep dormancy that can go on for up to a month at a time. In possums, these energy-saving events are not linked to specific seasons, and can occur year-round. In nature, they stay put in a nest of bark and leaves in tree hollows, underground or in bird nests. This puts these creatures at risk of falling victim to prescribed burns during winter, but also during the summer wildfires that are increasing in frequency in Australia because of climate change.

It was found that pygmy-possums are able to pick up the smell of smoke while experiencing torpor, but that their subsequent responses are temperature dependent. No movements were observed when the outdoor temperature stood at a cold 10 degrees Celsius and the possums had a low body temperature. By 15 degrees Celsius, the three males in the study aroused enough to start moving, while the two females still only lifted their heads. The animals' body temperature also played a role for their ability to move. When their body temperature was around 24 degrees Celsius, the pygmy-possums were able to perform advanced moves such as climbing up their tails. A drop of their body temperatures to below 13 degrees Celsius, caused their reactions and movements to be extremely slow and very basic.

The study is the first to show that animals are able to smell while in torpor. The results are particularly important in light of expected increases in the frequency of fires due to climate change. It also has implications concerning the implementation of prescribed burns during the colder months of the year. In many areas where bushfires occur regularly during summer, such as in Australia, prescribed burns are conducted in winter to reduce the amount of flammable plant material during the warmer months and to help maintain a healthy ecosystem.

"Prescribed burns during winter should be avoided on very cold days to allow torpid animals enough time to respond," says Nowack.




Contacts and sources: 
Joan Robinson
Springer

Citation: Nowack, J. et al (2016). Can hibernators sense and evade fires? Olfactory acuity and locomotor performance during deep torpor, The Science of Nature. DOI 10.1007/s00114-016-1396-6

Fungi Can Recycle Rechargeable Lithium-Ion Batteries

Although rechargeable batteries in smartphones, cars and tablets can be charged again and again, they don’t last forever. Old batteries often wind up in landfills or incinerators, potentially harming the environment. And valuable materials remain locked inside. Now, a team of researchers is turning to naturally occurring fungi to drive an environmentally friendly recycling process to extract cobalt and lithium from tons of waste batteries.

“The idea first came from a student who had experience extracting some metals from waste slag left over from smelting operations,” says Jeffrey A. Cunningham, Ph.D., the project’s team leader. “We were watching the huge growth in smartphones and all the other products with rechargeable batteries, so we shifted our focus. The demand for lithium is rising rapidly, and it is not sustainable to keep mining new lithium resources,” he adds.

Although a global problem, the U.S. leads the way as the largest generator of electronic waste. It is unclear how many electronic products are recycled. Most likely, many head to a landfill to slowly break down in the environment or go to an incinerator to be burned, generating potentially toxic air emissions.


The fungi Aspergillus niger (top left), Penicillium simplicissimum (top right) and Penicillium chrysogenum (bottom) can recycle cobalt and lithium from rechargeable batteries.

Credit: Aldo Lobos

While other methods exist to separate lithium, cobalt and other metals, they require high temperatures and harsh chemicals. Cunningham’s team is developing an environmentally safe way to do this with organisms found in nature — fungi in this case — and putting them in an environment where they can do their work. “Fungi are a very cheap source of labor,” he points out.

To drive the process, Cunningham and Valerie Harwood, Ph.D., both at the University of South Florida, are using three strains of fungi — Aspergillus niger, Penicillium simplicissimum and Penicillium chrysogenum. “We selected these strains of fungi because they have been observed to be effective at extracting metals from other types of waste products,” Cunningham says. “We reasoned that the extraction mechanisms should be similar, and, if they are, these fungi could probably work to extract lithium and cobalt from spent batteries.”

The team first dismantles the batteries and pulverizes the cathodes. Then, they expose the remaining pulp to the fungus. “Fungi naturally generate organic acids, and the acids work to leach out the metals,” Cunningham explains. “Through the interaction of the fungus, acid and pulverized cathode, we can extract the valuable cobalt and lithium. We are aiming to recover nearly all of the original material.”

Results so far show that using oxalic acid and citric acid, two of the organic acids generated by the fungi, up to 85 percent of the lithium and up to 48 percent of the cobalt from the cathodes of spent batteries were extracted. Gluconic acid, however, was not effective for extracting either metal.

The cobalt and lithium remain in a liquid acidic medium after fungal exposure, Cunningham notes. Now his focus is on how to get the two elements out of that liquid.

“We have ideas about how to remove cobalt and lithium from the acid, but at this point, they remain ideas,” he says. “However, figuring out the initial extraction with fungi was a big step forward.”

Credit: American Chemical Society

Other researchers are also using fungi to extract metals from electronic scrap, but Cunningham believes his team is the only one studying fungal bioleaching for spent rechargeable batteries.

Cunningham, Harwood and graduate student Aldo Lobos are now exploring different fungal strains, the acids they produce and the acids’ efficiencies at extracting metals in different environments.

The team has received funding for this project from the National Science Foundation.

The researchers presented their work on August 21 at the 252nd National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through August 25. It features more than 9,000 presentations on a wide range of science topics.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.



Contacts and sources:
Michael Bernstein
Katie Cottingham, Ph.D.
American Chemical Society (ACS)

After An Heart Attack: Injectable Hydrogels Could Prevent Future Heart Failure (Video)


Credit: American Chemical Society

During a heart attack, clots or narrowed arteries block blood flow, harming or killing cells within the tissue. But the damage doesn’t end after the crushing pain subsides. Instead, the heart’s walls thin out, the organ becomes enlarged, and scar tissue forms. If nothing is done, the patient can eventually experience heart failure. But scientists now report they have developed gels that, in animal tests, can be injected into the heart to shore up weakened areas and prevent heart failure.


Credit: American Chemical Society

Heart attacks strike 750,000 people each year in the U.S., according to the American Heart Association. And more than 5 million U.S. residents are living with heart failure, with symptoms that progress from fatigue and shortness of breath to eventual death. “Heart failure is a huge problem, and few therapies are available for these patients,” says Jason A. Burdick, Ph.D., leader of the study.

Treatments include lifestyle changes, medication, implants or heart transplants. Burdick, who is at the University of Pennsylvania (Penn), explains that these options often don’t work well or, in the case of transplants, are hard to come by. So scientists are pursuing other treatment methods. For instance, researchers at other institutions have done animal studies in which they injected cells into the damaged section of the heart to try to repair damage. 

To prevent the cells from leaking out, those researchers embedded them in biodegradable “hydrogels” — water-swollen networks of polymer chains with a consistency similar to Jell-OTM. But the scientists noticed something odd when they ran control experiments in which they injected the hydrogel without added cells: Some of the animals’ hearts still showed improvement compared with untreated animals.

Based on those findings, a handful of labs are now experimenting with hydrogel treatments, including two materials that are in clinical trials. Neither is from Burdick’s lab, but as he notes, “It’s important we all keep moving forward to figure out how this therapy could be used, because it’s different than any current treatment.” In addition, different types of hydrogels could suit different patients’ needs.

Some experimental heart attack treatments require surgery to open up the chest, but the two hydrogel materials already in clinical trials are injected into the damaged tissue through a long catheter inserted through the skin — eliminating the need for open-chest surgery.

Burdick and his graduate student Christopher B. Rodell, in collaboration with Robert C. Gorman, M.D., also at Penn, are using this same minimally invasive technique in their own work. But his team has gone a step further by identifying properties that would be useful in treating heart attack patients and then designing hydrogels with those properties. For instance, his group developed a hydrogel that forms additional crosslinks between the polymer chains after injection. The resulting material is stiffer and lasts longer than a gel without these additional crosslinks and the gels in clinical trials.

In fact, Burdick’s gel is unique among hydrogels in providing mechanical support to stabilize the damaged area. In sheep studies, this gel limits formation of scar tissue, thinning of the heart’s walls and enlargement of the heart. By preserving the organ’s size, the gels also reduce leakage of blood through the mitral valve. Together, these benefits maintain the heart’s blood-pumping ability and could stave off heart failure.

The team’s materials are based on hyaluronic acid (HA), a type of sugar molecule that occurs naturally in the body. The researchers modified the HA molecules by attaching adamantane and cyclodextrin groups to allow the gels to flow through catheters, and they added thiol and methacrylate groups to enable post-injection cross-linking to stiffen the hydrogel. Once the researchers finalize the hydrogel formulation and delivery method, they hope to partner with a catheter firm to bring a product to market. Burdick’s team and other research groups are also designing hydrogels that contain drugs or cells that can repair heart tissue.

The researchers presented their work August 22nd at the 252nd National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through August 25th. It features more than 9,000 presentations on a wide range of science topics.

He acknowledges funding from the National Institutes of Health and theAmerican Heart Association.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.


Contacts and sources:
Michael Bernstein
Katie Cottingham, Ph.D.
American Chemical Society (ACS)

Paper-Based Device Detects Falsified or Degraded Medications (Video)

The developing world is awash in substandard, degraded or falsified medications, which can either directly harm users or deprive them of needed treatment. And with internet sales of medications on the rise, people everywhere are increasingly at risk. So, a team of researchers has developed a simple, inexpensive paper-based device to screen suspicious medications.

 
Credit: American Chemical Society

“People who don’t have access to the best-quality medicines also don’t have as many resources to buy the analytical instrumentation to detect the quality problems,” says Marya Lieberman, Ph.D. “Instead of a $30,000 instrument, we’ve developed a $1 paper card. We designed the card so it would be as easy and inexpensive to use as possible.”

Medications can be compromised in many different ways. For example, they may be bulked up with fillers, or they can degrade because they are stored improperly. Identifying poor-quality medications is challenging, as inspectors may not know in advance what chemical adulterants or degradation products they need to look for. Plus, bad-quality medications may contain at least some of the active ingredient, so simply detecting the presence of the real medication isn’t enough to rule out issues.

Credit: American Chemical Society

In this study, Lieberman of the University of Notre Dame, along with Hamline University undergraduate Sarah Bliese, developed a card to detect falsified or degraded antibiotics such as ciprofloxacin or ceftriaxone, both of which the World Health Organization lists as “essential.” To screen for a variety of potential quality issues, the researchers included 12 lanes separated by wax barriers on the paper device. Each lane contained a different set of reagents to detect materials or functional groups found in active pharmaceutical ingredients, degradation products or common fillers.

To run a sample, the researchers crush a pill and rub the resulting powder across all 12 lanes, and then dip the bottom of the paper card in water for three minutes. The water wicks up the lanes, bringing reagents into contact with the powder. Colors are formed when the reagents interact with the pharmaceutical, filler or degradation product. The researchers then compare the color pattern from the sample with the color patterns obtained from high-quality pharmaceutical products. The comparison can be done by eye or with an image-analysis program on a smartphone.

Ceftriaxone is sensitive to heat and breaks down if storage temperatures climb too high. As an experiment, the researchers subjected ceftriaxone to high temperatures and ran the card test, simultaneously analyzing the degradation products via liquid chromatography-mass spectrometry. They verified that the colorimetric pattern for the degraded antibiotic was different from that of the correctly stored product. In addition to these tests on the pure active ingredient, Lieberman and Bliese analyzed dozens of real-world samples of ceftriaxone from Kenya and Uganda.

Credit: American Chemical Society

Unscrupulous makers of falsified medication sometimes add colorants containing toxic heavy metals to their products to make the illicit pills more closely resemble their legitimate counterparts, Bliese says. So, in a related project at Hamline University, Bliese and Deanna O'Donnell, Ph.D., are exploring whether a portable X-ray fluorescence spectroscopy device can scan pills for these substances.

In June, Lieberman and Bliese traveled to Kenya to test a new paper card which can detect substandard antibiotics. While Lieberman is currently focusing her work on the developing world, she says her cards could be applicable worldwide to perform, for example, the analysis of herbal medicines and nutritional supplements. “Sometimes those ‘herbal products’ are actually spiked with pharmaceuticals,” she explains. “The paper test cards could be a defense against this.” Bliese says her next project will be to develop a paper test card to help first responders identify drugs of abuse and differentiate them from household products or legitimate medicines.

The researchers will presented their work August 21 at the 252nd National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through August 25. It features more than 9,000 presentations on a wide range of science topics.  

Lieberman acknowledges funding from the US-AID Development Innovation Ventures program, the Bill & Melinda Gates Foundation and the Indiana Clinical and Translational Sciences Institute. Bliese acknowledges funding from theNational Science Foundation REU program.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.



Contacts and sources:
Michael Bernstein
Katie Cottingham, Ph.D.
American Chemical Society (ACS)