Here is the latest American Chemical Society (ACS) News Service Weekly PressPac with news from ACS’ 36 peer-reviewed journals and Chemical & Engineering News.
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In research that may redefine ear buds, earphones, stereo loudspeakers, and other devices for producing sound, researchers in China are reporting development of flexible loudspeakers thinner than paper that might be inserted into the ears with an index finger or attached to clothing, walls, or windows. Their report on what may be the world’s thinnest loudspeakers, made from transparent carbon nanotube films, is scheduled for the December 10 issue of ACS’ Nano Letters, a monthly journal.
Kaili Jiang, Shoushan Fan, and colleagues note that most of today’s loudspeakers are relatively bulky, complex, and inflexible, consisting of a permanent magnet fixed to a voice coil and a cone. To meet the growing demand for smaller speakers for portable digital consumer electronics devices, manufacturers need new technology, they say.
The scientists describe the development of super-thin carbon nanotube (CNT) films — 1/1,000th the width of a single human hair — that are capable of transmitting music and other sounds. In laboratory tests, the researchers mounted a thin CNT film onto two electrodes to form a simple loudspeaker. The speaker produced sound with the same excellent quality as conventional loudspeakers, but without magnets and moving components, the researchers say. They also demonstrated that the flexible film could be used just as effectively to play music from an iPod and while pasted to a flexible, waving flag (please see accompanying video).
“These CNT thin film loudspeakers are transparent, flexible, and stretchable, which can be tailored into many shapes and mounted on a variety of insulating surfaces, such as room walls, ceilings, pillars, windows , flags, and clothes without limitations. Furthermore, CNT thin films can also be made into small area devices, such as earphones and buzzers. There is no doubt that more and more applications will be developed as time goes on. This technique might open new applications of and approaches to manufacturing loudspeakers and other acoustic devices.”— MTS
Click the links below to view videos of the loudspeakers using QuickTime:
CNT loudspeakers play music while being stretched
CNT speakers play movie soundtrack via iPod
CNT speakers pasted onto a flag
Researchers in Spain and the United Kingdom are reporting development of a faster test for identifying the food protein that triggers celiac disease, a difficult-to-diagnose digestive disease involving the inability to digest protein called gluten that occurs in wheat, oats, rye, and barley. The finding could help millions of people avoid diarrhea, bloating, and other symptoms that occur when they unknowingly eat foods containing gluten. The study is scheduled for the December 15 issue of Analytical Chemistry, a semi-monthly journal.
In the new report, Alex Fragoso, Ciara O’Sullivan and colleagues note that patients with celiac disease can avoid symptoms by avoiding foods that contain gluten. Doing so can be tricky, however, because gluten may be a hidden ingredient in unsuspected foods, such as soy sauce, canned soups, and licorice candy. Some prepared foods list gluten content on package labels, but identifying its presence remains difficult and time-consuming.
The scientists describe development of a new sensor that detects antibodies to the protein gliadin, a component of gluten. Laboratory tests showed that it is superior to the so-called enzyme-linked immunosorbent assay (ELISA), now the standard test for gliadin. It took the new test barely 90 minutes to detect gliadin in the parts per billion range, compared to 8 hours for the ELISA test. Although both tests were equally accurate, the new sensor would be easier to use at food manufacturing plants, the researchers note. — MTS
Researchers in Missouri have borrowed the technology that living cells use to produce energy to develop a tiny, self-powered sensor for rapid detection of hidden explosives. The experimental sensor, about the size of a postage stamp, represents the first of its kind to be powered by mitochondria, the microscopic “powerhouses” that provide energy to living cells, the researchers say. Their study is scheduled for the November 26 issue of the weekly Journal of the American Chemical Society.
In the new study, Shelley Minteer, Marguerite Germain, and Robert Arechederra point out that today’s explosives detectors are expensive, bulky, and complex. Society needs smaller, cheaper, simpler detection devices, based on technology that perhaps could be incorporated into cell phones and portable digital music players, the researchers suggest.
The scientists describe development of an experimental sensor built from a special biofuel cell, essentially a battery-like device consisting of a thin layer of mitochondria sandwiched between a carbon-based electrode and a gas-permeable electrode. In laboratory studies using nitrobenzene as a test compound, the sensor showed a significant boost in electrical power in the presence of the substance, demonstrating the sensor’s potential for detecting TNT and related explosives, the researchers say. — MTS
Journal: Journal of the American Chemical Society
Journal Article: “Nitroaromatic Actuation of Mitochondrial Bioelectrocatalysis for Self-Powered Explosive Sensors”
Counterintuitive as it may seem, those healthful phytoestrogen nutrients that consumers usually associate with fruits and vegetables also exist in foods of animal origin. After all, “phyto” means “plant.” Now the first comprehensive study of phytoestrogen content in foods has identified the best sources of these nutrients. The study is scheduled for the November 26 issue of ACS’ bi-weekly Journal of Agricultural and Food Chemistry.
In the study, Gunter G. C. Kuhnle, Laure Thomas and colleagues point out that phytoestrogens have garnered increasing attention for their beneficial role in preventing several diseases, including osteoporosis, type-2 diabetes and certain cancers. But much of the scientific research on these compounds has focused on their occurrence in plant-based foods, which has led to an underestimation of actual amounts people consume, the study says.
The researchers analyzed 115 foods of animal origin and found that all food groups studied contained phytoestrogens. Isoflavones — one of the three major classes of these compounds — were considerably higher in soy-based foods. In fact, the amount of phytoestrogens in soy-based infant formula was more than 300 times higher than in normal infant formula. In animal products, phytoestrogens are low when compared to foods containing soy, the paper notes, but the range is similar to that of many commonly consumed vegetables. — JS
Journal: Journal of Agricultural and Food Chemistry
Journal Article: “Phytoestrogen Content of Foods of Animal Origin: Dairy Products, Eggs, Meat, Fish, and Seafood”
In the face of growing environmental concerns and a renewed interest in energy efficiency, the construction of homes and businesses that emphasize “green” construction materials is on the rise, according to an article scheduled for the November 17 issue of Chemical & Engineering News, ACS’ weekly newsmagazine.
In the two-part C&EN cover story, Senior Business Editor Melody Voith notes that while green building materials were once viewed as a trendy environmental statement focusing on natural or recyclable items, these materials now are emerging as practical, high-performance products that also provide energy efficiency. The market for green building products and services was $12 billion in 2007 and experts project it to increase to $60 billion by 2010, the article notes.
Today, a “green building” usually refers to a commercial building or home that has been certified as such by the U.S. Green Building Council (USGBC) for its use of environmentally-friendly materials, among other considerations. The USGBC plans to release updated certification standards in 2009 that emphasize lower energy use and reduced greenhouse gas emissions, the article notes. The U.S. Department of Energy, meanwhile, assists builders in making homes more energy efficient by publishing guideline specifications for insulation, windows, ductwork, appliances, and other items. Says one producer of construction materials, “All of a sudden, green is becoming serious and growing up. It is a huge shift in how buildings are designed and constructed.”
It's never too late to explore a treasure trove of news sources, background material and story ideas available from the ACS' latest National Meeting, which was held in Philadelphia from August 17-21, 2008. Reporters can view press releases, search an archive with abstracts of more than 9,000 scientific presentations and hundreds of non-technical summaries of those presentations, and access other resources at: www.eurekalert.org/acsmeet.php.
The ACS Office of Public Affairs also offers recorded video versions of its national meeting "chat room" briefings and accompanying chat transcripts by going to http://www.ustream.tv/channel/acslive. To use this site, you must first register with Ustream.tv by going to http://ustream.tv/sign-up-step-1. It's free and only takes a minute or two to sign up. To view the archived chat room sessions, proceed by clicking the "Login" button at the top right of the Ustream window and then selecting "Past Clips." Please note that Ustream requires the latest version of Adobe Flash, which can be downloaded without charge at http://www.adobe.com/products/flashplayer.
Don’t miss this special series of ACS podcasts on some of the 21st Century’s most daunting challenges, and how cutting-edge research in chemistry matters in the quest for solutions. This sweeping panorama of challenges includes topics such as providing a hungry, thirsty world with ample supplies of safe food and clean water; developing alternatives to petroleum to fuel the global economy; preserving the environment and assuring a sustainable future for our children; and improving human health. An ongoing saga of chemistry for life — chemistry that truly matters — Global Challenges debuts June 25 with new episodes through December. Subscribe at iTunes or listen and access other resources at the ACS web site www.acs.org/GlobalChallenges.
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PressPac information is intended for your personal use in news gathering and reporting and should not be distributed to others. Anyone using advance PressPac information for stocks or securities dealing may be guilty of insider trading under the federal Securities Exchange Act of 1934.
The American Chemical Society — the world’s largest scientific society — is a nonprofit organization chartered by the U.S. Congress 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.
Journal: Chemical & Engineering News
Journal Article: “High-Performance Buildings”