Breakthrough drug-eluting patch stops scar growth, reduces scar tissues

Scars — in particular keloid scars that result from overgrowth of skin tissue after injuries or surgeries — are unsightly and can even lead to disfigurement and psychological problems of affected patients. Individuals with darker pigmentation — in particular people with African, Hispanic or South-Asian genetic background — are more likely to develop this skin tissue disorder. Current therapy options, including surgery and injections of corticosteroids into scar tissues, are often ineffective, require clinical supervision and can be costly.A new invention by researchers from Nanyang Technological University in Singapore (reported in the current issue of TECHNOLOGY) provides a simple, affordable and — most importantly — highly effective way for patients to self-treat keloid scars. The team of scientists and engineers from NTU’s School of Chemical and Biomedical Engineering, in collaboration with clinicians from Singapore’s National Skin Centre, have developed a special patch made from polymers fabricated into microneedles, which are loaded with the US food and drug administration (FDA)-approved scar-reducing drug, 5-fluorouracil. Self-administered by patients, the microneedles attach the patch to scar tissue and allow sustained drug-release (one patch per night). The drug as well as the physical contact of the microneedles with the scar tissue contributes to the efficacy of the device, leading to the cessation of scar tissue growth and a considerable reduction of keloids as demonstrated in laboratory cultures and experiments with animals. “Most patients seek treatment due to disfigurement and/or pain or itch of scars,” says Assistant Professor Xu Chenjie from NTU who leads the study. “We wanted to develop a simple, convenient, and cost-effective device able to inhibit keloid growth in skin tissue and reduce the size of disfiguring scars,” adds Yuejun Kang, another key investigator in the study from NTU.”Self-administered treatment for keloid scars can reduce the economic burden on the healthcare system and provide a treatment option for patients who have limited access to medical care,” comments Professor Jeffrey Karp from Brigham and Women’s Hospital at Harvard Medical School, US, an expert on medical device design who was not involved in this study.Story Source:The above story is based on materials provided by World Scientific. Note: Materials may be edited for content and length.

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Key chocolate ingredients could help prevent obesity, diabetes

Improved thinking. Decreased appetite. Lowered blood pressure. The potential health benefits of dark chocolate keep piling up, and scientists are now homing in on what ingredients in chocolate might help prevent obesity, as well as type-2 diabetes. They found that one particular type of antioxidant in cocoa prevented laboratory mice from gaining excess weight and lowered their blood sugar levels. The report appears in ACS’ Journal of Agricultural & Food Chemistry.Andrew P. Neilson and colleagues explain that cocoa, the basic ingredient of chocolate, is one of the most flavanol-rich foods around. That’s good for chocolate lovers because previous research has shown that flavanols in other foods such as grapes and tea can help fight weight gain and type-2 diabetes. But not all flavanols, which are a type of antioxidant, are created equal. Cocoa has several different kinds of these compounds, so Neilson’s team decided to tease them apart and test each individually for health benefits.The scientists fed groups of mice different diets, including high-fat and low-fat diets, and high-fat diets supplemented with different kinds of flavanols. …

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Bamboo-loving giant pandas also have a sweet tooth

Despite the popular conception of giant pandas as continually chomping on bamboo to fulfill a voracious appetite for this reedy grass, new research from the Monell Center reveals that this highly endangered species also has a sweet tooth. A combination of behavioral and molecular genetic studies demonstrated that the giant panda both possesses functional sweet taste receptors and also shows a strong preference for some natural sweeteners, including fructose and sucrose.”Examining an animal’s taste DNA can give us clues to their past diet, knowledge that is particularly important for endangered animals in captivity,” said study author Danielle Reed, PhD, a behavioral geneticist at Monell. “This process can provide information on approaches to keep such animals healthy.”The Monell researchers studied the giant pandas as part of a long-term project focused on understanding how taste preferences and diet selection are shaped by taste receptor genes.One previous study found that cats, which must eat meat in order to survive, had lost the ability to taste sweets due to a genetic defect that deactivates the sweet taste receptor.Although giant pandas and cats belong to the same taxonomic order, Carnivora, the giant pandas have a very different diet, as they feed almost exclusively on bamboo.Noting that bamboo is a grass-like plant that contains very small amounts of sugars and does not taste sweet to humans, the researchers wondered whether giant pandas, like their Carnivora cat relatives, had lost sweet taste perception. An alternate possibility was that the panda maintain a functional sweet taste receptor, similar to other plant-eating mammals.In this study, published online in the open-access journal PLOS ONE, eight giant pandas between three and 22 years of age were studied at the Shaanxi Wild Animal Rescue and Research Center in China over a six-month period.For taste preference tests, the animals were given two bowls of liquid and allowed to drink for five minutes. One bowl contained water and the other contained a solution of water mixed with one of six different natural sugars: fructose, galactose, glucose, lactose, maltose, and sucrose. Each sugar was presented at a low and a high concentration.The pandas preferred all the sugar solutions to plain water. This was especially evident for fructose and sucrose, as the animals avidly consumed a full liter of these sugary solutions within the respective five-minute test periods.”Pandas love sugar,” said Reed. “Our results can explain why Bao Bao, the six-month-old giant panda cub at the National Zoo in Washington, DC, is apparently relishing sweet potato as a first food during weaning.”Another series of preference tests explored the giant panda’s response to five artificial sweeteners. There was little to no preference for most artificial sweetener solutions, suggesting that giant pandas cannot taste or do not strongly perceive these compounds as being sweet.Parallel cell-based studies showed a relationship between the pandas’ behavior and how panda taste receptor cells respond to sweeteners in vitro. Using DNA collected from the giant pandas during routine health examinations, genes that code for the panda sweet taste receptor were isolated and then inserted into human host cells grown in culture. …

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Light-activated antimicrobial surface that also works in the dark: World’s first

Researchers at UCL have developed a new antibacterial material which has potential for cutting hospital acquired infections. The combination of two simple dyes with nanoscopic particles of gold is deadly to bacteria when activated by light — even under modest indoor lighting. And in a first for this type of substance, it also shows impressive antibacterial properties in total darkness.The research, from by Sacha Noimark and Ivan Parkin (both UCL Chemistry) and Elaine Allan (UCL Eastman Dental Institute), is published today in the journal Chemical Science.Hospital-acquired infections are a major issue for modern medicine, with pathogens like methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile (C. diff) getting extensive publicity. Although medical establishments have stringent cleaning policies, insist on frequent hand-washing by staff, and have powerful drugs at their disposal, it is difficult to eliminate these infections unless you can make the hospital environment more hostile to microbes. Surfaces, such as door handles, medical equipment, keyboards, pens and so on are an easy route for germs to spread, even onto freshly-cleaned hands.One possible solution to this is to develop alternative strategies such as antibacterial coatings that make surfaces less accommodating to germs. These surfaces are not like antibacterial fluids that just wash away — the goal is to make a surface which is intrinsically deadly to harmful bacteria.”There are certain dyes that are known to be harmful to bacteria when subjected to bright light,” explains the study’s corresponding author Ivan Parkin (Head of UCL Chemistry). “The light excites electrons in them, promoting the dye molecules to an excited triplet state and ultimately produces highly reactive oxygen radicals that damage bacteria cell walls. Our project tested new combinations of these dyes along with gold nanoparticles, and simplified ways of treating surfaces which could make the technology easier and cheaper to roll out.”The team, tested several different combinations of the dyes crystal violet (already used to treat staph infections), methylene blue and nanogold, deposited on the surface of silicone. This flexible rubbery substance is widely used as a sealant, a coating and to build medical apparatus such as tubes, catheters and gaskets, and can also be used as protective casings for things like keyboards and telephones.While work to create antimicrobial surfaces in the past has often concentrated on complex ways of bonding dyes to the surface, this study took a simpler approach. …

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Fighting antibiotic resistance with ‘molecular drill bits’

In response to drug-resistant “superbugs” that send millions of people to hospitals around the world, scientists are building tiny, “molecular drill bits” that kill bacteria by bursting through their protective cell walls. They presented some of the latest developments on these drill bits, better known to scientists as antimicrobial peptides (AMPs), at the 247th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society.The meeting features more than 10,000 scientific reports across disciplines from energy to medicine.One of the researchers in the search for new ways to beat pathogenic bacteria is Georges Belfort, Ph.D. He and his team have been searching for a new therapy against the bacteria that cause tuberculosis (TB). It’s a well-known, treatable disease, but resistant strains are cropping up. The World Health Organization estimates that about 170,000 people died from multidrug-resistant TB in 2012.”If the bacteria build resistance to all current treatments, you’re dead in the water,” said Belfort, who is at Rensselaer Polytechnic Institute.To avoid this dire scenario, scientists are developing creative ways to battle the disease. In ongoing research, Belfort’s group together with his wife, Marlene Belfort, and her group at the University at Albany are trying to dismantle bacteria from within. They also decided to attack it from the outside.In their search for a way to do this, they came upon AMPs. Although these naturally occurring, short strings of amino acids are not new — all classes of organisms from humans to bacteria produce them as part of their natural defense strategy — the fight against drug-resistant pathogens has heightened attention on these protective molecules.Researchers began studying them in earnest in the 1980s. By 2010, they had identified nearly 1,000 unique AMPs from many sources, including fly larvae, frog skin and mammalian immune system cells. The molecules come in different shapes, lengths and with other varying traits. …

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A battery that ‘breathes’ could power next-gen electric vehicles

Sales of electric vehicles (EVs) nearly doubled in 2013, but most won’t take you farther than 100 miles on one charge. To boost their range toward a tantalizing 300 miles or more, researchers are reporting new progress on a “breathing” battery that has the potential to one day replace the lithium-ion technology of today’s EVs. They presented their work at the 247th National Meeting & Exposition of the American Chemical Society (ACS) in Dallas this week.”Lithium-air batteries are lightweight and deliver a large amount of electric energy,” said Nobuyuki Imanishi, Ph.D. “Many people expect them to one day be used in electric vehicles.”The main difference between lithium-ion and lithium-air batteries is that the latter replaces the traditional cathode — a key battery component involved in the flow of electric current — with air. That makes the rechargeable metal-air battery lighter with the potential to pack in more energy than its commercial counterpart.While lithium-air batteries have been touted as an exciting technology to watch, they still have some kinks that need to be worked out. Researchers are forging ahead on multiple fronts to get the batteries in top form before they debut under the hood.One of the main components researchers are working on is the batteries’ electrolytes, materials that conduct electricity between the electrodes. There are currently four electrolyte designs, one of which involves water. The advantage of this “aqueous” design over the others is that it protects the lithium from interacting with gases in the atmosphere and enables fast reactions at the air electrode. The downside is that water in direct contact with lithium can damage it.Seeing the potential of the aqueous version of the lithium-air battery, Imanishi’s team at Mie University in Japan tackled this issue. Adding a protective material to the lithium metal is one approach, but this typically decreases the battery power. …

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Don’t throw out old, sprouting garlic — it has heart-healthy antioxidants

“Sprouted” garlic — old garlic bulbs with bright green shoots emerging from the cloves — is considered to be past its prime and usually ends up in the garbage can. But scientists are reporting in ACS’ Journal of Agricultural and Food Chemistry that this type of garlic has even more heart-healthy antioxidant activity than its fresher counterparts.Jong-Sang Kim and colleagues note that people have used garlic for medicinal purposes for thousands of years. Today, people still celebrate its healthful benefits. Eating garlic or taking garlic supplements is touted as a natural way to reduce cholesterol levels, blood pressure and heart disease risk. It even may boost the immune system and help fight cancer. But those benefits are for fresh, raw garlic. Sprouted garlic has received much less attention. When seedlings grow into green plants, they make many new compounds, including those that protect the young plant against pathogens. Kim’s group reasoned that the same thing might be happening when green shoots grow from old heads of garlic. Other studies have shown that sprouted beans and grains have increased antioxidant activity, so the team set out to see if the same is true for garlic.They found that garlic sprouted for five days had higher antioxidant activity than fresher, younger bulbs, and it had different metabolites, suggesting that it also makes different substances. …

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Pinwheel ‘living’ crystals and the origin of life

Simply making nanoparticles spin coaxes them to arrange themselves into what University of Michigan researchers call ‘living rotating crystals’ that could serve as a nanopump. They may also, incidentally, shed light on the origin of life itself.The researchers refer to the crystals as ‘living’ because they, in a sense, take on a life of their own from very simple rules.Sharon Glotzer, the Stuart W. Churchill Collegiate Professor of Chemical Engineering, and her team found that when they spun individual nanoparticles in a simulation — some clockwise and some counterclockwise — the particles self-assembled into an intricate architecture.The team discovered the behavior while investigating methods to make particles self-assemble — one of the major challenges in nanotechnology — without complicated procedures. When the pieces are a thousand times smaller than a grain of sand, normal techniques for building structures are no longer effective.For this reason, researchers like Glotzer are exploring ways to make order develop naturally from disorder, much like what may have occurred at the very beginnings of life.”If we can understand that, not only can we begin to imagine new ways to make materials and devices, but also we may begin to understand how the first living structures emerged from a soup of chemicals,” said Glotzer, who is also a professor of materials science and engineering, macromolecular science and engineering, physics, and applied physics.”One way biology approaches the challenge of assembly is by constantly feeding building blocks with energy. So, that’s what we did with nanoparticles.”Recently, researchers in the field have found that if particles are given energy for some basic motion, such as moving in one direction, they can begin to influence one another, forming groups. Glotzer’s team looked at what would happen if the particles all were made to rotate.”They organize themselves,” said Daphne Klotsa, a research fellow in Glotzer’s lab. “They developed collective dynamics that we couldn’t have foreseen.”The team’s computer simulation can be imagined as two sets of pinwheels on an air hockey table. The air pushing up from the table drives some of the pinwheels clockwise, and others counterclockwise. When the pinwheels are tightly packed enough that their blades catch on one another, the team found that they begin to divide themselves into clockwise and counter-clockwise spinners — a self-organizing behavior known among researchers as phase separation.”The important finding here is that we get phase separation without real attraction,” Klotsa said.She calls the self-sorting counterintuitive because no direct forces push the same — spin pinwheels together or push opposite-spinners apart.The separation occurs because of the way the pinwheel blades collide. While a pair of pinwheels may be spinning in the same direction, where their blades might meet, they’re actually moving in opposite directions. …

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Soy and phytoestrogens, explained

Learn more about Herbalife – Follow @Herbalife on Twitter- Like Herbalife on Facebook- What is Herbalife? More fitness advice – Watch ‘Fit Tips’ Videos on YouTube- Straightforward exercise advice- Get fit = be happy. Positivity advice Nutrition advice for you – Watch ‘Healthy Living’ on YouTube- Dieting advice you might like- Interesting weight loss articles Copyright © 2013 Herbalife International of America, Inc.

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New depression treatments reported

New insights into the physiological causes of depression are leading to treatments beyond common antidepressants such as Prozac and Zoloft, according to an evidence-based report in the journal Current Psychiatry.Depression treatments on the horizon include new medications, electrical and magnetic stimulation of the brain and long-term cognitive behavioral therapy for stress management.Authors are Murali Rao, MD, and Julie M. Alderson, DO. Rao is professor and chair of the Department of Psychiatry and Behavioral Neurosciences at Loyola University Chicago Stritch School of Medicine, and Alderson is a resident at East Liverpool City Hospital in East Liverpool, Ohio.For more than 50 years, depression has been studied and understood as a deficiency of chemical messengers, called neurotransmitters, that carry signals between brain cells. Commonly used antidepressants are designed to either increase the release or block the degradation of three neurotransmitters — dopamine, norepinephrine and serotonin.But drugs that target neurotransmitters, such as Prozac, Zoloft and Paxil, succeed in inducing the remission of depression in fewer than half of patients. This has prompted researchers “to look beyond neurotransmitters for an understanding of depressive disorders,” Rao and Alderson write.New theories of depression are focusing on differences in neuron density in various regions of the brain; on the effect of stress on the birth and death of brain cells; on the alteration of feedback pathways in the brain and on the role of inflammation evoked by the stress response.Chronic stress is believed to be the leading cause of depression, the authors write. Long-term stress harms cells in the brain and body. Stressful experiences are believed to be closely associated with the development of psychological alterations and, thus, neuropsychiatric disorders. In conditions of chronic stress exposure, nerve cells in the hippocampus begin to atrophy. (The hippocampus is a part of the brain involved with emotions, learning and memory formation.)The new depression theories “should not be viewed as separate entities because they are highly interconnected,” Rao and Alderson write. “Integrating them provides for a more expansive understanding of the pathophysiology of depression and biomarkers that are involved.”Such biomarkers are molecules in the body that can be indicators of depression. …

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New plant species a microcosm of biodiversity

Biologists working in the Andes mountains of Ecuador have described a new plant species, a wild relative of black pepper, that is in itself a mini biodiversity hotspot. The new species, Piper kelleyi, is the sole home of an estimated 40-50 insect species, most of which are entirely dependent on this plant species for survival. This discovery is part of a larger project which focuses on the influence of plant-produced chemical compounds on biodiversity.The study was published in the open access journal PhytoKeys.The chemical compounds produced by plants are source of plants’ unique flavors, aromas, and colors. What’s less appreciated is that these compounds often have important medicinal or toxic properties, and are the plant’s natural way to resist pesky herbivores. Black pepper and its wild relatives produce a wide diversity of chemical compounds, many of which are known to be biologically active (in fact, several compounds from the new species are currently under evaluation, and show promise as possible anti-cancer drugs). These compounds are known to deter most herbivores, but a certain group of caterpillars has been able to overcome their toxicity and, as a result, most species of the genus feed only on a single species of wild black pepper. To make matters more complex, each of these caterpillars typically has one to several predatory wasp and/or fly species that attack only that caterpillar species.Our team of scientists has made nearly 30,000 observations of over 100 black pepper relatives over 20+ years, and the new plant species described here supports the largest number of specialized caterpillar and predator species recorded for species in the black pepper family to date. Many of these insect species were discovered as a result of our investigations and are new to science (many remain unnamed). Piper kelleyi supports an estimated 40-50 species of specialized herbivores and predators, which makes this newly described plant species, in itself, a veritable biodiversity hotspot. Are there any vertebrate species that depend on this plant? …

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How to tell when bubbly goes bad before popping the cork

In the rare case that New Year’s revelers have a bottle of leftover bubbly, they have no way to tell if it’ll stay good until they pop the cork and taste it at the next celebration. But now scientists are reporting a precise new way for wineries — and their customers — to predict how long their sparkling wines will last. The study appears in ACS’ Journal of Agricultural and Food Chemistry.Montserrat Riu-Aumatell and colleagues explain that the shelf life of various sparkling wines, from champagne to prosecco, depends on environmental factors such as temperature. Currently, wineries detect the so-called browning of bubbly by measuring its “absorbance,” or its absorption of light at a particular wavelength. It’s a fast and easy technique but not very sensitive. Researchers exploring the chemistry of sparkling wine are turning to the food industry for alternatives. Food manufacturers can measure a compound called 5-HMF, which builds up in food as it goes bad, to tell when to toss a product out. Riu-Aumatell’s team decided to see if they could use the compound, which is also found in bubbly, to predict the shelf life of sparkling wines.They tested levels of this browning compound in several bottles stored over two years at different temperatures: room, cellar (61 degrees Fahrenheit) and refrigerator (39 degrees Fahrenheit). Their study found that 5-HMF is a good indicator of freshness, and also that refrigerating sparkling wines almost completely prevented browning. To make their results more practical for wineries, the researchers came up with a mathematical model that predicts how long products will stay drinkable at varying storage temperatures.Story Source:The above story is based on materials provided by American Chemical Society. …

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Herbicides may not be sole cause of declining plant diversity

The increasing use of chemical herbicides is often blamed for the declining plant biodiversity in farms. However, other factors beyond herbicide exposure may be more important to species diversity, according to Penn State researchers.If herbicides are a key factor in the declining diversity, then thriving species would be more tolerant to widely used herbicides than rare or declining species, according to J. Franklin Egan,research ecologist, USDA-Agricultural Research Service.”Many ecotoxicology studies have tested the response of various wild plant species to low dose herbicide exposures, but it is difficult to put these findings in context,” said Egan. “Our approach was to compare the herbicide tolerances of plant species that are common and plant species that are rare in an intensively farmed region. We found that rare and common plant species had roughly similar tolerances to three commonly used herbicides.”This could mean that herbicides may not have a persistent effect in shaping plant communities.The researchers, who report their findings in the online version of the journal Environmental Toxicology and Chemistry, said that over the past several decades, in the same time that the use of herbicides was on the rise, other factors such as the simplification of crop rotations, segregation of crop and livestock and increasing mechanization have also been rapidly evolving. In addition, the clearing of woodlots, hedgerows, pastures and wetlands to make way for bigger fields has continued apace and resulted in habitat loss.While the findings are preliminary, the approach could be effective in clarifying the implications of herbicide pollution for plant conservation, Egan said.”These findings are not an invitation to use herbicides recklessly,” he said. “There are many good reasons to reduce agriculture’s reliance on chemical weed control. But, for the objective of plant species conservation, other strategies like preserving farmland habitats including woodlots, pastures and riparian buffers may be more effective than trying to reduce herbicide use.”Egan worked with David Mortensen, professor of weed and applied plant ecology, and Ian Graham, an undergraduate student in plant science.Story Source:The above story is based on materials provided by Penn State. The original article was written by Jennifer Lynch. Note: Materials may be edited for content and length.

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Antibiotic ‘smart bomb’ can target specific strains of bacteria

Researchers from North Carolina State University have developed a de facto antibiotic “smart bomb” that can identify specific strains of bacteria and sever their DNA, eliminating the infection. The technique offers a potential approach to treat infections by multi-drug resistant bacteria.”Conventional antibiotic treatments kill both ‘good’ and ‘bad’ bacteria, leading to unintended consequences, such as opportunistic infections,” says Dr. Chase Beisel, an assistant professor of chemical and biomolecular engineering at NC State and senior author of a paper describing the work. “What we’ve shown in this new work is that it is possible to selectively remove specific strains of bacteria without affecting populations of good bacteria.”The new approach works by taking advantage of a part of an immune system present in many bacteria called the CRISPR-Cas system. The CRISPR-Cas system protects bacteria from invaders such as viruses by creating small strands of RNA called CRISPR RNAs, which match DNA sequences specific to a given invader. When those CRISPR RNAs find a match, they unleash Cas proteins that cut the DNA.The NC State researchers have demonstrated that designing CRISPR RNAs to target DNA sequences in the bacteria themselves causes bacterial suicide, as a bacterium’s CRISPR-Cas system attacks its own DNA.”In lab testing, we found that this approach removes the targeted bacteria,” Beisel says. “We’re still trying to understand precisely how severing the DNA leads to elimination of the bacteria. However, we’re encouraged by the ease in specifically targeting different bacteria and the potency of elimination.”The researchers tested the approach in controlled cultures with different combinations of bacteria present, and were able to eliminate only the targeted strain. “For example, we were able to eliminate Salmonella in a culture without affecting good bacteria normally found in the digestive tract,” Beisel says.The researchers were also able to demonstrate the precision of the technique by eliminating one strain of a species, but not another strain of the same species which shares 99 percent of the same DNA.Another benefit of the approach, Beisel says, is that “by targeting specific DNA strands through the CRISPR-Cas system, we’re able to bypass the mechanisms underlying the many examples of antibiotic resistance.”The researchers are currently working to develop effective methods for delivering the CRISPR RNAs in clinical settings.”This sets the stage for next-generation antibiotics using programmable CRISPR-Cas systems,” says Dr. Rodolphe Barrangou, an associate professor of food, bioprocessing and nutrition sciences at NC State and co-author of the manuscript.Story Source:The above story is based on materials provided by North Carolina State University. …

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New catalyst to convert greenhouse gases into chemicals

A team of researchers at the University of Delaware has developed a highly selective catalyst capable of electrochemically converting carbon dioxide — a greenhouse gas — to carbon monoxide with 92 percent efficiency. The carbon monoxide then can be used to develop useful chemicals.The researchers recently reported their findings in Nature Communications.”Converting carbon dioxide to useful chemicals in a selective and efficient way remains a major challenge in renewable and sustainable energy research,” according to Feng Jiao, assistant professor of chemical and biomolecular engineering and the project’s lead researcher.Co-authors on the paper include Qi Lu, a postdoctoral fellow, and Jonathan Rosen, a graduate student, working with Jiao.The researchers found that when they used a nano-porous silver electrocatalyst, it was 3,000 times more active than polycrystalline silver, a catalyst commonly used in converting carbon dioxide to useful chemicals.Silver is considered a promising material for a carbon dioxide reduction catalyst because of it offers high selectivity — approximately 81 percent — and because it costs much less than other precious metal catalysts. Additionally, because it is inorganic, silver remains more stable under harsh catalytic environments.The exceptionally high activity, Jiao said, is likely due to the UD-developed electrocatalyst’s extremely large and highly curved internal surface, which is approximately 150 times larger and 20 times intrinsically more active than polycrystalline silver.Jiao explained that the active sites on the curved internal surface required a much smaller than expected voltage to overcome the activation energy barrier needed drive the reaction.The resulting carbon monoxide, he continued, can be used as an industry feedstock for producing synthetic fuels, while reducing industrial carbon dioxide emissions by as much as 40 percent.To validate whether their findings were unique, the researchers compared the UD-developed nano-porous silver catalyst with other potential carbon dioxide electrocatalysts including polycrystalline silver and other silver nanostructures such as nanoparticles and nanowires.Testing under identical conditions confirmed the non-porous silver catalyst’s significant advantages over other silver catalysts in water environments.Reducing greenhouse carbon dioxide emissions from fossil fuel use is considered critical for human society. Over the last 20 years, electrocatalytic carbon dioxide reduction has attracted attention because of the ability to use electricity from renewable energy sources such as wind, solar and wave.Ideally, Jiao said, one would like to convert carbon dioxide produced in power plants, refineries and petrochemical plants to fuels or other chemicals through renewable energy use.A 2007 Intergovernmental Panel on Climate Change report stated that 19 percent of greenhouse gas emissions resulted from industry in 2004, according to the Environmental Protection Agency’s website.”Selective conversion of carbon dioxide to carbon monoxide is a promising route for clean energy but it is a technically difficult process to accomplish,” said Jiao. “We’re hopeful that the catalyst we’ve developed can pave the way toward future advances in this area.”The research team’s work is supported through funding from the American Chemical Society Petroleum Research Fund and University of Delaware Research Foundation. Jiao has patented the novel application technique in collaboration with UD’s Office of Economic Innovation and Partnerships.Story Source:The above story is based on materials provided by University of Delaware. The original article was written by Karen B. Roberts. Note: Materials may be edited for content and length.

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Is the Outlawing of Psychoactive Drugs Tantamount to Scientific ‘Censorship’?

Is the Outlawing of Psychoactive Drugs Tantamount to Scientific ‘Censorship’?October 4th 2013 | By: Staff | Posted In: Drugs and Alcohol, Policy and RegulationThree researchers are protesting the current laws on psychoactive drugs such as marijuana and “magic” mushrooms. These three researchers – David Nutt and Leslie King from Imperial College, London, and David Nichols from the University of North Carolina – believe that the current laws are akin to scientific censorship and say that the unfortunate consequence of laws restricting psychoactive drugs is that research studies that could be conducted to find a valid use in treating anxiety, depression or post-traumatic stress are now impossible.Propagators of this view on the current psychoactive law say that the legal prescription drugs often used to treat these …

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Scientists use blur to sharpen DNA mapping

Oct. 9, 2013 — With high-tech optical tools and sophisticated mathematics, Rice University researchers have found a way to pinpoint the location of specific sequences along single strands of DNA, a technique that could someday help diagnose genetic diseases.Proof-of-concept experiments in the Rice lab of chemist Christy Landes identified DNA sequences as short as 50 nucleotides at room temperature, a feat she said is impossible with standard microscopes that cannot see targets that small, or electron microscopes that require targets to be in a vacuum or cryogenically frozen.The technique called “super-localization microscopy” has been known for a while, Landes said, but its application in biosensing is just beginning. Scientists have seen individual double-stranded DNA molecules under optical microscopes for years, but the ability to see single-stranded DNA is a new achievement, and breaking the diffraction limit of light adds value, she said.The work by Landes, Rice postdoctoral associate Jixin Chen and undergraduate student Alberto Bremauntz is detailed in the American Chemical Society journal Applied Materials and Interfaces.The Rice researchers call their super-resolution technique “motion blur point accumulation for imaging in nanoscale topography” (mbPAINT). With it, they resolved structures as small as 30 nanometers (billionths of a meter) by making, essentially, a movie of fluorescent DNA probes flowing over a known target sequence along an immobilized single strand of DNA.The probes are labeled with a fluorescent dye that lights up only when attached to the target DNA. In the experimental setup, most would flow by unseen, but some would bind to the target for a few milliseconds, just long enough to be captured by the camera before the moving liquid pulled them away. Processing images of these brief events amidst the background blur allows the researchers to image objects smaller than the natural diffraction limits of light-based imaging, which do not allow for the resolution of targets smaller than the wavelength of light used to illuminate them.Even the Landes lab’s system is subject to these physical limitations. Individual images of fluorescing probes on targets are just a pixelated blur. But it’s a blur with a bright spot, and careful analysis of multiple images allows the researchers to pinpoint that spot along the strand.”The probes are moving so fast that in real time, all we would see with the camera is a line,” Chen said. But when the camera firing at 30-millisecond intervals happened to catch a bound probe, it clearly stood out. The probes sometime picked out two sequences along a strand that would have been seen as a single blur via regular fluorescent microscopy.Landes said one goal for mbPAINT is to map ever-smaller fragments of DNA. …

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Carbon’s new champion: Carbyne, a simple chain of carbon atoms, strongest material of all?

Oct. 9, 2013 — Carbyne will be the strongest of a new class of microscopic materials if and when anyone can make it in bulk.If they do, they’ll find carbyne nanorods or nanoropes have a host of remarkable and useful properties, as described in a new paper by Rice University theoretical physicist Boris Yakobson and his group. The paper appears this week in the American Chemical Society journal ACS Nano.Carbyne is a chain of carbon atoms held together by either double or alternating single and triple atomic bonds. That makes it a true one-dimensional material, unlike atom-thin sheets of graphene that have a top and a bottom or hollow nanotubes that have an inside and outside.According to the portrait drawn from calculations by Yakobson and his group:* Carbyne’s tensile strength — the ability to withstand stretching — surpasses “that of any other known material” and is double that of graphene. (Scientists had already calculated it would take an elephant on a pencil to break through a sheet of graphene.)* It has twice the tensile stiffness of graphene and carbon nanotubes and nearly three times that of diamond.* Stretching carbyne as little as 10 percent alters its electronic band gap significantly.* If outfitted with molecular handles at the ends, it can also be twisted to alter its band gap. With a 90-degree end-to-end rotation, it becomes a magnetic semiconductor.* Carbyne chains can take on side molecules that may make the chains suitable for energy storage.* The material is stable at room temperature, largely resisting crosslinks with nearby chains.That’s a remarkable set of qualities for a simple string of carbon atoms, Yakobson said.”You could look at it as an ultimately thin graphene ribbon, reduced to just one atom, or an ultimately thin nanotube,” he said. It could be useful for nanomechanical systems, in spintronic devices, as sensors, as strong and light materials for mechanical applications or for energy storage.”Regardless of the applications,” he said, “academically, it’s very exciting to know the strongest possible assembly of atoms.”Based on the calculations, he said carbyne might be the highest energy state for stable carbon. “People usually look for what is called the ‘ground state,’ the lowest possible energy configuration for atoms,” Yakobson said. “For carbon, that would be graphite, followed by diamond, then nanotubes, then fullerenes. But nobody asks about the highest energy configuration. …

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Motorized microscopic matchsticks move in water with sense of direction

Sep. 10, 2013 — Chemists, physicists and computer scientists at the University of Warwick have come together to devise a new powerful and very versatile way of controlling the speed and direction of motion of microscopic structures in water using what they have dubbed chemically ‘motorised microscopic matchsticks’.Before now most research seeking to influence the direction of motion of microscopic components have had to use outside influences such as a magnetic field or the application of light. The University of Warwick team have now found a way to do it by simply adding a chemical in a specific spot and then watching the microscopic matchstick particles move towards it, a phenomenon known as chemotaxis.The research published in the journal Materials Horizons (RSC) in a paper entitled “Chemotaxis of catalytic silica-manganese oxide “matchstick” particles” found that by adding a small amount of a catalyst to the head of a set microscopic rods, they could then cause the rods to be propelled towards the location of an appropriate ‘chemical fuel’ that was then added to a mixture.For the purposes of this experiment the researchers placed silica-manganese oxide ‘heads’ on the matchstick material and introduced hydrogen peroxide as the chemical fuel in one particular place.They placed the ‘matchsticks’ in a mixture alongside ordinary polymer microspheres.When the hydrogen peroxide was added the microspheres continued to move in the direction of convection currents or under Brownian motion but the matchsticks were clearly rapidly propelled towards the chemical gradient where the hydrogen peroxide could be found.The reaction was so strong that more than half of the matchstick particles did not reverse their orientation once over their 90 seconds of travel towards the hydrogen peroxide — even though they were contending with significant convection and Brownian rotation.University of Warwick research chemical engineer Dr Stefan Bon who led the research said:”We choose high aspect ratio rod-like particles as they are a favourable geometry for chemotactic swimmers, as seen for example in nature in the shapes of certain motile organisms””We placed the ‘engine’ that drives the self-propulsion as a matchstick head on the rods because having the engine in the ‘head’ of the rod helps us align the rod along the direction of travel, would also show the asymmetry perpendicular to the direction of self-propulsion, and at the same time it maintains rotational symmetry parallel to the plane of motion.”Our approach is very versatile and should allow for future fabrication of micro-components of added complexity.”The ability to direct motion of these colloidal structures can form a platform for advances in supracolloidal science, the self-assembly of small objects.”It may even provide some insight into how rod shapes were selected for self-propelled microscopic shapes in the natural world.”

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Recycled sewage water is safe for crop irrigation, study suggests

Sep. 9, 2013 — The first study under realistic field conditions has found reassuringly low levels of pharmaceuticals and personal care products (PPCPs) in crops irrigated with recycled sewage water, scientists reported in Indianapolis today at the 246th National Meeting & Exposition of the American Chemical Society (ACS).”The levels of pharmaceuticals and personal care products that we found in food crops growing under real-world conditions were quite low and most likely do not pose any health concern,” said Jay Gan, Ph.D., who led the study. “I think this is good news. These substances do not tend to accumulate in vegetables, including tomatoes and lettuce that people often eat raw. We can use that information to promote the use of this treated wastewater for irrigation.”Gan and colleagues at the University of California-Riverside launched the study because drought and water shortages in the American southwest and in other arid parts of the world are using water recycled from municipal sewage treatment plants to irrigate food crops as the only option.Water from toilets and sinks enters those facilities from homes and offices, and undergoes processing to kill disease-causing microbes and remove other material. Processing leaves that water, or “effluent,” from most sewage treatment plants clean enough to drink. Traditionally, however, sewage treatment plants simply discharge the water into rivers or streams. The effluent still may contain traces of impurities, including the remains of ingredients in prescription drugs, anti-bacterial soaps, cosmetics, shampoos and other PPCPs that are flushed down toilets and drains.Gan explained that concerns have arisen about the health and environmental effects of those residual PPCPs, especially over whether they might accumulate to dangerous levels in food crops. Previous studies on PPCPs in food crops were small in scale and conducted in laboratories or greenhouses. Gan said his team was the first to focus on 20 PPCPs in multiple crops under realistic field conditions.They chose eight vegetables that people often eat raw — carrots, bell peppers, tomatoes, cucumbers, lettuce, spinach, celery and cabbage. …

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