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Wednesday, August 24, 2016

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)

Watching Thoughts — And Addiction — Form in The Brain in Real Time

More than a hundred years ago, Ivan Pavlov conducted what would become one of the most famous and influential psychology studies — he conditioned dogs to salivate at the ringing of a bell. Now, scientists are able to see in real time what happens in the brains of live animals during this classic experiment with a new technique. Ultimately, the approach could lead to a greater understanding of how we learn, and develop and break addictions.



The study presented is part of the event: “Kavli symposium on chemical neurotransmission: What are we thinking?” It includes a line-up of global research and thought leaders at the multi-disciplinary interfaces of the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative with a focus on chemists’ contributions. The effort was launched in 2013 by the Obama Administration to enable researchers to study how brain cells interact to form circuits.

“We developed cell-based detectors called CNiFERs that can be implanted in a mouse brain and sense the release of specific neurotransmitters in real time,” says Paul A. Slesinger, Ph.D., who used this tool to revisit Pavlov’s experiment. Neurotransmitters are the chemicals that transmit messages from one neuron to another.

In a mouse brain, cell-based detectors called CNiFERs change their fluorescence when neurons release dopamine.
Credit: Slesinger & Kleinfeld labs 

CNiFERs stands for “cell-based neurotransmitter fluorescent engineered reporters.” These detectors emit light that is readable with a two-photon microscope and are the first optical biosensors to distinguish between the nearly identical neurotransmitters dopamine and norepinephrine. These signaling molecules are associated respectively with pleasure and alertness.

Slesinger, of the Icahn School of Medicine at Mount Sinai in New York, collaborated on the project with David Kleinfeld, Ph.D., at the University of California at San Diego. Their team conditioned mice by playing a tone and then, after a short delay, rewarding them with sugar. After several days, the researchers could play the tone, and the mice would start licking in anticipation of the sugar.

“We were able to measure the timing of dopamine surges during the learning process,” Slesinger says. “That’s when we could see the dopamine signal was measured initially right after the reward. Then after days of training, we started to detect dopamine after the tone but before the reward was presented.”

Slesinger and colleagues will also share new results on the first biosensors that can detect a subset of neurotransmitters called neuropeptides. Ultimately, Slesinger says they’d like to use this sensing technique to directly measure these neuromodulators, which affect the rate of neuron firing, in real time.

Scientists will be presented their work on August 22 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.

Slesinger and Kleinfeld acknowledge funding from the National Institute on Drug Abuse, the National Institute of Biomedical Imaging and Bioengineering andHoffmann-La Roche.




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

Delicious Trick: Machine To Infuse Sweet, Fat and Salty Tastes and Aromas in Healthy Foods to Fool the Brain

Scientists may be closing in on a way to let consumers savor the sweet taste of cake, cookies and other culinary delights without the sugar rush. In preliminary tests using a new device developed in-house that allows them to screen for odor compounds in real foods, they have isolated several natural aromatic molecules that could be used to trick our brains into believing that desserts and other foods contain more fat, sugar or salt than they actually do.

“Most consumers know that they should be eating more healthful foods made with reduced amounts of fat, sugar and salt. But this is problematic because these are the very ingredients that make many of the foods we like taste so delicious,” says Thierry Thomas-Danguin, Ph.D. “Based on our lab work, we’ve come to believe that aromas can help compensate for the reduction of fat, sugar and salt in healthful foods and make them more appealing to consumers.”

Adding certain aromas to foods made with less fat, sugar or salt could make these products more appealing to consumers.

Credit: Stockbyte/Thinkstock

Aroma plays a vital role in how we perceive food (just try pinching your nose closed while you eat — odds are you won’t taste anything). Based on this fact, food scientists have long used chemical aromatics, essential oils and botanical extracts to enhance the flavor of food and beverages to boost sales.

Recently, scientists have turned their attention to using aromas to improve the taste of foods made with reduced amounts of fat, sugar and salt, which many consumers avoid because of their notoriously bland flavor.

“If you buy a product made with 30 percent less salt, and you don’t like it because it isn’t very tasty, what do you do?” Thomas-Danguin asks. “You’ll probably reach for the table salt and put some into the product. So the target is missed. Our goal is to optimize the reformulation process, so the food industry can produce more healthful products that consumers will like as they are and will choose to eat them regularly.”

In earlier work, Thomas-Danguin set out to prove that if the right aroma is added in the right amount in the right places in the right food, the brain can be fooled into thinking there is more fat, sugar or salt in it. Study participants were asked to taste flan, a type of custard, made in layers containing varying amounts of ham aroma and salt. The researchers found that the ham aroma, even though it contained no salt, increased the perception of saltiness of the flan. In fact, some participants thought one variation of the custard made with ham aroma and salt distributed unevenly in layers throughout it tasted the same as a flan made in the traditional way with 40 percent more salt.

In their latest study, Thomas-Danguin and his colleagues at the Centre des Sciences du Goût de l’Alimentation in France, sought to find a new way to isolate aroma molecules associated with sweet tastes. So they created a first-of-its-kind device called a Gas Chromatograph-Olfactometry Associated Taste (GC-OAT) and used it in conjunction with an olfactoscan, which delivers a continuous stream of aromas through a tube to a subject’s nose.

Participants were asked to smell real fruit juice aroma through the olfactoscan. Meanwhile, the researchers used the GC-OAT to isolate molecules from the juice. Then, they added the molecules one at a time into the olfactoscan tube. As the participants smelled each of these mixtures, they were asked if the molecule contributed to their perceived sweetness of the fruit juice. Thomas-Danguin says the preliminary results suggest that this new technique could eventually help food manufacturers better formulate more healthful foods without sacrificing taste, aroma or texture of the original products.

The researchers presented their work on August 22 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 Thursday. It features more than 9,000 presentations on a wide range of science topics.

Thomas-Danguin acknowledges funding from EU-FP7, EU-ERDF, EU-MSCA,Unilever R & D Vlaardingen, L.D.C. Group, INRA, Carnot Institute Qualiment andRegional Council of Burgundy.

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)

Time of Day Affects Our Susceptibility to Infection, Helps Explain why Shift Workers More Prone to Health Problems

We are more susceptible to infection at certain times of the day as our body clock affects the ability of viruses to replicate and spread between cells, suggests new research from the University of Cambridge.

The findings, published August 15 in the Proceedings of the National Academy of Sciences, may help explain why shift workers, whose body clocks are routinely disrupted, are more prone to health problems, including infections and chronic disease.

When a virus enters our body, it hijacks the machinery and resources in our cells to help it replicate and spread throughout the body. However, the resources on offer fluctuate throughout the day, partly in response to our circadian rhythms – in effect, our body clock. Circadian rhythms control many aspects of our physiology and bodily functions – from our sleep patterns to body temperature, and from our immune systems to the release of hormones. These cycles are controlled by a number of genes, including Bmal1 and Clock.

Credit: Alexandra Bilham

To test whether our circadian rhythms affect susceptibility to, or progression of, infection, researchers at the Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, compared normal ‘wild type’ mice infected with herpes virus at different times of the day, measuring levels of virus infection and spread. The mice lived in a controlled environment where 12 hours were in daylight and 12 hours were dark.

The researchers found that virus replication in those mice infected at the very start of the day – equivalent to sunrise, when these nocturnal animals start their resting phase – was ten times greater than in mice infected ten hours into the day, when they are transitioning to their active phase. When the researchers repeated the experiment in mice lackingBmal1, they found high levels of virus replication regardless of the time of infection.

“The time of day of infection can have a major influence on how susceptible we are to the disease, or at least on the viral replication, meaning that infection at the wrong time of day could cause a much more severe acute infection,” explains Professor Akhilesh Reddy, the study’s senior author. “This is consistent with recent studies which have shown that the time of day that the influenza vaccine is administered can influence how effectively it works.”

In addition, the researchers found similar time-of-day variation in virus replication in individual cell cultures, without influence from our immune system. Abolishing cellular circadian rhythms increased both herpes and influenza A virus infection, a dissimilar type of virus – known as an RNA virus – that infects and replicates in a very different way to herpes.

Dr Rachel Edgar, the first author, adds: “Each cell in the body has a biological clock that allows them to keep track of time and anticipate daily changes in our environment. Our results suggest that the clock in every cell determines how successfully a virus replicates. When we disrupted the body clock in either cells or mice, we found that the timing of infection no longer mattered – viral replication was always high. This indicates that shift workers, who work some nights and rest some nights and so have a disrupted body clock, will be more susceptible to viral diseases. If so, then they could be prime candidates for receiving the annual flu vaccines.”

As well as its daily cycle of activity, Bmal1 also undergoes seasonal variation, being less active in the winter months and increasing in summer. The researchers speculate that this may help explain why diseases such as influenza are more likely to spread through populations during winter.

Using cell cultures, the researchers also found that herpes viruses manipulate the molecular ‘clockwork’ that controls our circadian rhythms, helping the viruses to progress. This is not the first time that pathogens have been seen to ‘game’ our body clocks: the malaria parasite, for example, is known to synchronise its replication cycle with the host’s circadian rhythm, producing a more successful infection.


“Given that our body clocks appear to play a role in defending us from invading pathogens, their molecular machinery may offer a new, universal drug target to help fight infection,” adds Professor Reddy.

The research was mostly funded by the Wellcome Trust and the European Research Council.



Contacts and sources:
Craig Brierley
University of Cambridge

Citation: Edgar, RS et al. Cell autonomous regulation of herpes and influenza virus infection by the circadian clock. PNAS; e-pub 15 Aug 2016; DOI: 10.1073/pnas.1601895113

New Wrinkle: Squid, Jellyfish and Human Skin Inspire Materials for Anti-Glare Screens and Encryption

What do squid and jellyfish skin have in common with human skin? All three have inspired a team of chemists to create materials that change color or texture in response to variations in their surroundings. These materials could be used for encrypting secret messages, creating anti-glare surfaces, or detecting moisture or damage, they say.

“Our experimental materials use cracks, folds or wrinkles to mimic the surface engineering of skin,” says Luyi Sun, Ph.D., who heads the research. “These new materials are unique because they change color or transparency when they’re stretched or exposed to moisture.”

Human fingers wrinkle when they’ve been submerged in water for a while. But jellyfish skin can also wrinkle, Sun’s graduate student Songshan Zeng says. “When they’re scared, some types of jellyfish form a wrinkled surface that is opaque and warns off predators,” says Zeng, who has a leading role in the project. “That same surface is transparent when it’s flat.” Even more impressive is the reaction of a squid when it is startled: Muscles in its skin contract, exposing colored pigments that serve as camouflage.


A coating on a circuit board is unobservable when dry (top) but wrinkles to display “H2O” when exposed to moisture (bottom).
Credit: Songshan Zeng


Sun’s team and their collaborator, Dianyun Zhang, Ph.D., who are all at the University of Connecticut, studied these three types of skin to determine how surface engineering alters their properties in response to changes in the environment. The researchers replicated the wrinkled surfaces by placing a rigid thin film of polyvinyl alcohol on a rubbery base of polydimethylsiloxane (PDMS). “Like finger skin, whenever part of the film is exposed to moisture, it swells slightly, generating wrinkles,” Sun says. Because the wrinkled part of the film is opaque, it can be used to form patterns — such as letters — that appear when the film is moistened. Sun notes that his is one of very few teams studying the dynamics of moisture-induced wrinkles, including how long they last and how to reverse them.

The presence and degree of crosslinking between polymer chains in the thin film dictates whether the wrinkling is reversible. On the one hand, if the film is formulated without crosslinking, wrinkles can be generated by moisture and subsequently smoothed out, but they cannot form again. This would be useful for displaying a message and then permanently erasing it once it’s read — a feature that James Bond would appreciate, Zeng notes. 

On the other hand, if the film has a certain type of crosslinking, wrinkles generated by moisture can never be erased. Thus, a small label incorporating the technology could go inside a cell phone (or on any circuit board). If the phone fell into a toilet, permanent wrinkles would form on the label in any desired shape (such as the chemical formula for water, “H2O”). This would be a dead give-away to a vendor that a customer had voided the warranty.

The researchers are also working on another cell phone application for wrinkled materials. Because wrinkles scatter light rays in multiple directions, rather than reflecting them directly back at a viewer, a different formulation of the material could make a cheap and effective anti-glare screen for phones, the researchers note.

In a separate project, Sun’s group mimicked squid skin by creating a PDMS base layer containing a small amount of fluorescent dye and coating it with a rigid thin film of polyvinyl alcohol/clay composite. The clay makes the surface layer prone to developing a multitude of tiny cracks and folds. Stretching the material opens the folds and cracks on the originally smooth surface, altering its topography and appearance. Depending on the formulation, the film can reversibly change color, luminesce or go from clear to opaque. One potential application is a smart window containing a clear material that could be stretched slightly so it turns opaque to provide privacy. The team is the first to make these types of materials, Sun says.


The researchers presented their work on August 22 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 Thursday. It features more than 9,000 presentations on a wide range of science topics.

Sun acknowledges funding from the University of Connecticut and General Electric.'

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)

Citrus Fruits Help Prevent Obesity-Related Heart Disease, Liver Disease, Diabetes

Oranges and other citrus fruits are good for you — they contain plenty of vitamins and substances, such as antioxidants, that can help keep you healthy. Now a group of researchers reports that these fruits also help prevent harmful effects of obesity in mice fed a Western-style, high-fat diet.

“Our results indicate that in the future we can use citrus flavanones, a class of antioxidants, to prevent or delay chronic diseases caused by obesity in humans,” says Paula S. Ferreira, a graduate student with the research team.

More than one-third of all adults in the U.S. are obese, according to the U.S. Centers for Disease Control and Prevention. Being obese increases the risk of developing heart disease, liver disease and diabetes, most likely because of oxidative stress and inflammation, Ferreira says. When humans consume a high-fat diet, they accumulate fat in their bodies. Fat cells produce excessive reactive oxygen species, which can damage cells in a process called oxidative stress. The body can usually fight off the molecules with antioxidants. But obese patients have very enlarged fat cells, which can lead to even higher levels of reactive oxygen species that overwhelm the body’s ability to counteract them.

Healthful antioxidants in oranges and other citrus fruits could stave off some harmful effects of obesity.

Credit:  NIH

Citrus fruits contain large amounts of antioxidants, a class of which are called flavanones. Previous studies linked citrus flavanones to lowering oxidative stress in vitro and in animal models. These researchers wanted to observe the effects of citrus flavanones for the first time on mice with no genetic modifications and that were fed a high-fat diet.

The team, at Universidade Estadual Paulista (UNESP) in Brazil, conducted an experiment with 50 mice, treating them with flavanones found in oranges, limes and lemons. The flavanones they focused on were hesperidin, eriocitrin and eriodictyol. For one month, researchers gave groups either a standard diet, a high-fat diet, a high-fat diet plus hesperidin, a high-fat diet plus eriocitrin or a high-fat diet plus eriodictyol.

The high-fat diet without the flavanones increased the levels of cell-damage markers called thiobarbituric acid reactive substances (TBARS) by 80 percent in the blood and 57 percent in the liver compared to mice on a standard diet. But hesperidin, eriocitrin and eriodictyol decreased the TBARS levels in the liver by 50 percent, 57 percent and 64 percent, respectively, compared with mice fed a high-fat diet but not given flavanones. Eriocitrin and eriodictyol also reduced TBARS levels in the blood by 48 percent and 47 percent, respectively, in these mice. In addition, mice treated with hesperidin and eriodictyol had reduced fat accumulation and damage in the liver.

“Our studies did not show any weight loss due to the citrus flavanones,” says Thais B. Cesar, Ph.D., who leads the team. “However, even without helping the mice lose weight, they made them healthier with lower oxidative stress, less liver damage, lower blood lipids and lower blood glucose.”

Ferreira adds, “This study also suggests that consuming citrus fruits probably could have beneficial effects for people who are not obese, but have diets rich in fats, putting them at risk of developing cardiovascular disease, insulin resistance and abdominal obesity.”

Next, the team will explore how best to administer these flavanones, whether in citrus juice, by consuming the fruit or developing a pill with these antioxidants. In addition, the team plans to conduct studies involving humans, Cesar says.

Cesar acknowledges funding from the Support Program for Scientific Development of the School of Pharmaceutical Sciences at UNESP and byCitrosuco, an orange juice production company in Matão, Sao Paulo, Brazil.

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 through Thursday. 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)

Monday, August 22, 2016

San Salvador at Risk from Magma Buildup Beneath the City

Researchers from the EU-funded VUELCO project have found that the build-up of magma 6 kilometers below El Salvador’s Ilopango caldera means that the country’s capital, San Salvador, may be at risk from future volcanic eruptions.

San Salvador skyline, panoramic picture taken from the San Salvador Volcano

Credit: Wikipedia

The team, comprised of VUELCO researchers from the University of Bristol, UK, and El Salvador’s Ministry of the Environment and Natural Resources, studied the density distribution beneath the Ilopango caldera and how tectonic stresses – caused by movement of tectonic plates along fault lines – have on the build-up of magma at depth. The findings have been published in a recent issue of the journal ‘Nature Communications’.

A caldera is a large cauldron-like volcanic depression or crater, formed by the collapse of an emptied magma chamber. The depression often originates from very big explosive eruptions. In Guatemala and El Salvador, caldera volcanoes straddle tectonic fault zones along the Central American Volcanic Arc (CAVA). The CAVA is 1 500km long, stretching from Guatemala to Panama.

Specifically the Ilopango caldera is an eight kilometre by 11km volcanic collapse structure of the El Salvador Fault Zone. The collapsed caldera was the result of at least five large eruptions over the past 80 000 years. The last of these eruptions occurred around 1 500 years ago and produced enough volcanic ash to form a 15cm thick layer across an areas the size of the UK. The eruption was so powerful that it would have destroyed almost everything within a 100km radius, including a well-developed Mayan population. It also significantly disturbed Mayan populations as far as 200km away. The most recent eruptions were in 1879-1880 but were on a much smaller scale.

Panorama of the capital San Salvador, located in the Boquerón Volcano Valley
Credit: Wikipedia

‘Most earthquakes take place along the edges of tectonic plates, where many volcanoes are also located,’ commented VUELCO project coordinator and co-author of the study, Dr. Joachim Gottsmann. There is therefore a link between the breaking of rocks, which causes faults and earthquakes, and the movement of magma from depth to the surface, to feed a volcanic eruption. The link between large tectonic fault zones and volcanism is, however, not very well understood.’

Previous studies have shown that magma accumulation before a large caldera-forming eruption, as well as the caldera collapse itself, may be controlled by fault structures. However, the research team states that it’s unclear to what extent regional tectonic stresses influence magma accumulation between large caldera-forming eruptions.

The team discovered that the current tectonic stress field promotes the accumulation of magma and hydrothermal fluids at shallow (less than 6km) depth beneath Ilopango. The magma contains a considerable amount of gas, which indicates the system is charged to possibly feed the next eruption.

Lake Ilopango seen from the east, San Salvador city and San Salvador Volcano can be seen just behind the lake looming in the haze
File:Ilopango caldera.jpg
Credit: Lee Siebert (Smithsonian Institution)

‘Our results indicate that localized extension along the fault zone controls the accumulation, ascent and eruption of magma at Ilopango,’ said Dr. Gottsmann. ‘This fault-controlled magma accumulation and movement limits potential vent locations for future eruptions at the caldera in its central, western and northern part – an area that now forms part of the metropolitan area of San Salvador, which is home to two million people. As a consequence, there is a significant level of risk to San Salvador from future eruptions of Ilopango.’

Although these findings have only just been published, the VUELCO project officially ended in September 2015 and received just under EUR 3, 500 000 in EU funding. The project, a collaborative effort between European and Latin American researchers, devised global strategies for enhancing volcanic monitoring capacity, better data interpretation and the identification of reliable eruption precursors.


Contacts and sources: 
CORDIS
University of Bristol