GEN-ERIC News

Catastrophic bridge collapses in Minnesota, China and elsewhere have killed at least 58 people this year, and concrete weakened by water is partly to blame. A new study points to a waterproofing solution that lies close at hand—or, er, mouth: sodium acetate, the ingredient that gives salt-and-vinegar chips their delicious zing. Water seeps through concrete’s pores, cracking its exterior and damaging the steel beams within. Sodium acetate seals these pores from the inside, says researcher Awni Al-Otoom of the Jordan University of Science and Technology in Irbid, Jordan. When brushed onto concrete as part of a watery solution, the salty substance sinks in and forms crystals, partially plugging the pores. The crystals create an even better barrier when wet, since moisture—a drop of rain, say—makes them swell to fill openings more snugly.

MIT researchers have created a new structured gel that can rapidly change color in response to a variety of stimuli, including temperature, pressure, salt concentration and humidity. Among other applications, the structured gel could be used as a fast and inexpensive chemical sensor, said Edwin Thomas, MIT’s Morris Cohen Professor of Materials Science and Engineering. One place where such an environmental sensor could be useful is a food processing plant, where the sensor could indicate whether food that must remain dry has been overly exposed to humidity. Thomas is senior author of a paper on the work to be published in the Oct. 21 online edition of Nature Materials. Structured gels are those that feature an internal pattern such as layers. A critical component of the structured gel developed at MIT is a material that expands or contracts when exposed to certain stimuli. Those changes in the thickness of the gel cause it to change color, through the entire range of the visible spectrum of light. Objects that reflect different colors depending on which way you look at them already exist, but once those objects are manufactured, their properties can’t change. The MIT team set out to create a material that would change color in response to external stimuli.

Despite its deadly reputation, the gas carbon monoxide (CO) could actually save lives and boost health in future as a result of leading-edge UK research. Chemists at the University of Sheffield have discovered an innovative way of using targeted small doses of CO which could benefit patients who have undergone heart surgery or organ transplants and people suffering from high blood pressure. Although the gas is lethal in large doses, small amounts can reduce inflammation, widen blood vessels, increase blood flow, prevent unwanted blood clotting – and even suppress the activity of cells and macrophages* which attack transplanted organs. The researchers have developed innovative water-soluble molecules which, when swallowed or injected, safely release small amounts of CO inside the human body. Research carried out in the last decade had already highlighted possible advantages, as CO is produced in the body as part of its own natural defensive systems. However, the problem has been finding a safe way of delivering the right dose of CO to the patient. Conventional CO inhalation can run the risk of patients or medical staff being accidentally exposed to high doses. Now for the first time, thanks to chemistry, an answer appears to have been found.

MIT scientists propose that blood may help us think, in addition to its well-known role as the conveyor of fuel and oxygen to brain cells. “We hypothesize that blood actively modulates how neurons process information,” Christopher Moore, a principal investigator in the McGovern Institute for Brain Research at MIT, explained in an invited review in the October issue of the Journal of Neurophysiology. “Many lines of evidence suggest that blood does something more interesting than just delivering supplies. If it does modulate how neurons relay signals, that changes how we think the brain works.” According to Moore’s Hemo-Neural Hypothesis, blood is not just a physiological support system but actually helps control brain activity. Specifically, localized changes in blood flow affect the activity of nearby neurons, changing how they transmit signals to each other and hence regulating information flow throughout the brain. Ongoing studies in Moore’s laboratory support this view, showing that blood flow does modulate individual neurons. Moore’s theory has implications for understanding brain diseases such as Alzheimer’s, schizophrenia, multiple sclerosis and epilepsy.

A new membrane that mimics pores found in plants has applications in water, energy and climate change mitigation. Announced today in the international journal Science, the new plastic membrane allows carbon dioxide and other small molecules to move through its hourglass-shaped pores while preventing the movement of larger molecules like methane. Separating carbon dioxide from methane is important in natural gas processing and gas recovery from landfill. The new material was developed as part of an international collaboration involving researchers from Hanyang University in Korea, the University of Texas and CSIRO, through its Water for a Healthy Country Flagship. “This plastic will help solve problems of small molecule separation, whether related to clean coal technology, separating greenhouse gases, increasing the energy efficiency of water purification, or producing and delivering energy from hydrogen,” Dr Anita Hill of CSIRO Materials Science and Engineering said. “The ability of the new plastic to separate small molecules surpasses the limits of any conventional plastics. “It can separate carbon dioxide from natural gas a few hundred times faster than current plastic membranes and its performance is four times better in terms of purity of the separated gas.”

By mimicking a brick-and-mortar molecular structure found in seashells, University of Michigan researchers created a composite plastic that’s as strong as steel but lighter and transparent. It’s made of layers of clay nanosheets and a water-soluble polymer that shares chemistry with white glue. Engineering professor Nicholas Kotov almost dubbed it “plastic steel,” but the new material isn’t quite stretchy enough to earn that name. Nevertheless, he says its further development could lead to lighter, stronger armor for soldiers or police and their vehicles. It could also be used in microelectromechanical devices, microfluidics, biomedical sensors and valves and unmanned aircraft. Kotov and other U-M faculty members are authors of a paper on this composite material, “Ultrastrong and Stiff Layered Polymer Nanocomposites,” published in the Oct. 5 edition of Science. The scientists solved a problem that has confounded engineers and scientists for decades: Individual nano-size building blocks such as nanotubes, nanosheets and nanorods are ultrastrong. But larger materials made out of bonded nano-size building blocks were comparatively weak. Until now.

The brains of people with seasonal depression may be too efficient at bundling away a key chemical, a new study suggests. The finding in people with (SAD) backs the prevailing theory about the biochemical causes of depression, and could give clues into new ways to treat the condition. The prevailing theory of depression is that affected people do not have enough of certain neurotransmitters called monoamines – serotonin, norepinephrine, and dopamine – in the spaces between neurons. Most modern antidepressants work by blocking the absorption of these neurotransmitters back into the cell. However, there is little agreement on why levels are inadequate in the first place. It could be that depressed people produce lower volumes of the neurotransmitters, or they could break them down too rapidly. Or it could be that the neurotransmitters are removed from the junction between neurons, called the synaptic cleft, too quickly. Matthaeus Willeit and Harald Sitte at the University of Vienna in Austria and their colleagues now have evidence for the last of these – that serotonin is being removed too efficiently.

For two generations of physicists, it has been a standard belief that the neutron, an electrically neutral elementary particle and a primary component of an atom, actually carries a positive charge at its center and an offsetting negative charge at its outer edge. The notion was first put forth in 1947 by Enrico Fermi, a Nobel laureate noted for his role in developing the first nuclear reactor. But new research by a University of Washington physicist shows the neutron’s charge is not quite as simple as Fermi believed. Using precise data recently gathered at three different laboratories and some new theoretical tools, Gerald A. Miller, a UW physics professor, has found that the neutron has a negative charge both in its inner core and its outer edge, with a positive charge sandwiched in between to make the particle electrically neutral. “Nobody realized this was the case,” Miller said. “It is significant because it is a clear fact of nature that we didn’t know before. Now we know it.” The discovery changes scientific understanding of how neutrons interact with negatively charged electrons and positively charged protons. Specifically, it has implications for understanding the strong force, one of the four fundamental forces of nature (the others are the weak force, electromagnetism and gravity).

Rice University chemists have discovered a way to load dozens of molecules of the anti-cancer drug paclitaxel onto tiny gold spheres. The result is a tiny ball, many times smaller than a living cell that literally bristles with the drug. Paclitaxel, which is sold under the brand name Taxol®, prevents cancer cells from dividing by jamming their inner works. “Paclitaxel is one of the most effective anti-cancer drugs, and many researchers are exploring how to deliver much more of the drug directly to cancer cells,” said lead researcher Eugene Zubarev, the Norman Hackerman-Welch Young Investigator and assistant professor of chemistry at Rice. “We looked for an approach that would clear the major hurdles people have encountered – solubility, drug efficacy, bioavailability and uniform dispersion – and our initial results look very promising.” The research is available online and will appear in the Sept. 19 issue of the Journal of the American Chemical Society.

Easy-to-remove chewing gum is to become a reality, thanks to a major technological break-through. The announcement will be made this week at the BA Festival of Science in York. Revolymer, a spin out company from the University of Bristol, has completed development of its new Clean Gum that can be easily removed from shoes, clothes, pavements and hair. Preliminary results also indicate that the gum will degrade naturally in water. The company has completed initial street trials on pavements in local high streets as part of a collaborative agreement with local councils. In the two trials, leading commercial gums remained stuck to the pavements three out of four times. In all tests the Revolymer gum was removed within 24 hours by natural events. Professor Terence Cosgrove, of the University of Bristol and Chief Scientific Officer of Revolymer said: “The advantage of our Clean Gum is that it has a great taste, it is easy to remove and has the potential to be environmentally degradable.” “The basis of our technology is to add an amphiphilic polymer to a modified chewing gum formulation which alters the interfacial properties of the discarded gum cuds, making them less adhesive to most common surfaces.”

Attention Deficit Hyperactivity Disorder (ADHD) is a prevailing issue in the United States, with millions of children getting diagnosed every year. A new study reveals that Pycnogenol, (pic-noj-en-all), an antioxidant plant extract from the bark of the French maritime pine tree, reduces ADHD in children. The study shows Pycnogenol balances stress hormones, which lowers adrenaline and dopamine, resulting in a decrease of ADHD. The findings, to be published in an upcoming issue of the journal Nutritional Neuroscience is a spin-off of a 2006 study found in the journal of European Child & Adolescent Psychiatry that revealed Pycnogenol helped reduce hyperactivity and improve attention, concentration and motor-visual coordination in children with ADHD. The current study measures urine samples and blood samples of the children, which were not accounted for in the results of the original study. “Pycnogenol’s ability to naturally treat symptoms of ADHD is what makes this extract exceptionally pleasing to parents who may be uneasy about medicating their children with stimulant medications,"said Dr. Peter Rohdewald of the Institute of Pharmaceutical Chemistry at Germany’s University of Munster and one of the authors of the study.