October 12, 2006, 9:58 PM CT

Closer To Holy Grail Of Modern Chemistry

University of Chicago chemist David Mazziotti has developed a new method for determining the behavior of electrons in atoms and molecules, a key ingredient in predicting chemical properties and reactions. He presented the details of his method in the Oct. 6 issue of the journal Physical Review Letters.

"In his new paper, David Mazziotti has made a major advance in fundamental theory," said Nobel laureate Dudley Herschbach, the Frank Baird Jr. Professor of Science at Harvard University. "It will surely find wide application."

The behavior of electrons in atoms and molecules affects a number of significant chemical reactions that govern everyday phenomena, including the fuel efficiency of combustion engines, the depletion of ozone in the atmosphere, and the design of new medicines. The importance of electrons in these and countless other chemical phenomena have led researchers since the 1950s to seek an efficient way to determine the distribution of electrons in atoms and molecules.

There can be hundreds or even thousands of electrons moving around the nuclei of a molecule--far too a number of for their distribution in the molecule to be determined exactly even with modern supercomputers. But during the 1950s, researchers realized that they could, in principle, use only a pair of electrons to represent any number of electrons accurately.........

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October 10, 2006, 10:28 PM CT

Decaffeinated coffee is not caffeine-free

Coffee addicts who switch to decaf for health reasons may not be as free from caffeine's clutches as they think. A new study by University of Florida researchers documents that almost all decaffeinated coffee contains some measure of caffeine.

Caffeine is the most widely consumed drug in the world. And because coffee is a major source in the supply line, people advised to avoid caffeine because of certain medical conditions like hypertension should be aware that even decaffeinated brew can come with a kick, UF researchers report in this month's Journal of Analytical Toxicology.

"If someone drinks five to 10 cups of decaffeinated coffee, the dose of caffeine could easily reach the level present in a cup or two of caffeinated coffee," said co-author Bruce Goldberger, Ph.D., a professor and director of UF's William R. Maples Center for Forensic Medicine. "This could be a concern for people who are advised to cut their caffeine intake, such as those with kidney disease or anxiety disorders".

Despite caffeine's widespread use, most medical texts have no guidelines for intake, Goldberger said, but even low doses might adversely affect some people. So UF researchers set out to conduct a two-phase study designed to gauge just how much caffeine is likely to turn up in decaffeinated coffees.........

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October 8, 2006, 6:32 PM CT

Champagne Unlocks The Secrets Of Bubble Formation

"I am drinking the stars," Dom Perignon, the monk credited with inventing champagne supposedly proclaimed upon taking his first sip of the bubbly wine. Researchers in France now report one of the most comprehensive explanations for those stars - the bubble trains that rise with that graceful sensuality from each fluted glass, which led poet Lord Byron to muse, "Champagne with foaming whirls, as white as Cleopatra's melted pearls".

The new study, conducted by the University of Reims' Gerard Liger-Belair and his colleagues, explains that the bubbles begin with minute cylindrical fibers deposited on champagne glasses from the air or towels used to dry the glasses. (For an extra bubbly experience, wipe the glass vigorously with a towel before pouring, the researchers advise. For fewer bubbles, avoid towel drying and keep the glass turned upside down.).

The report, in the current (Oct. 4) issue of the biweekly ACS Journal of Agricultural and Food Chemistry, describes how interactions between tiny gas pockets near the fibers influence the bubble trains. The researchers state that their observations in a champagne glass could have broader applications in food processing, medicine and other fields where undesired bubbles form.........

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October 8, 2006, 6:23 PM CT

Healthful Compounds In Native American Diets

California's role as a national "health food" trendsetter goes back farther than most people suspect -- way back, in fact, when it comes to consumption of a food particularly rich in healthy phytochemicals. In an advance toward understanding the early California Native American diet, food researchers have identified the full range of phytochemicals in tanoak acorns.

Acorns were a staple in the diet of early Native Americans in California, comprising up to 50 percent of total food intake, Alyson E. Mitchell and his colleagues note in a report in the current (Oct. 4) issue of the ACS biweekly Journal of Agricultural and Food Chemistry. Acorns are still used by Californian Native Americans -- special processing is needed to make the nuts edible -- to make acorn flour and soup.

Past research has indicated that acorns have higher levels of healthful tannin compounds than other nuts, so Mitchell's group set out to identify the specific hydrolyzable and condensed tannins in acorns. These same compounds are found in wine, cocoa and other foods with health benefits. Scientists identified more than two dozen specific compounds, in what they termed a first step toward understanding the role of those compounds in Native American diets.........

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October 8, 2006, 5:57 PM CT

Devoting More Research To Webicillin

Could a dose of webicillin beat that stubborn infection? Could a cobweb bandage help soldiers and accident victims with bleeding wounds? Is a wrapping of spider silk the key to preventing the body from rejecting implants?

A review of research on spider silk concludes that scientists have largely overlooked such possible medical applications of this extraordinary natural material, which is stronger than steel. In a report in the current (Sept. 13) issue of the ACS monthly journal Chemical Reviews, Randolph V. Lewis, of the University of Wyoming, describes other scientific research on spider silk during the last 15 years.

"Very few studies of biological testing of spider silk have been done in a rigorous manner," Lewis states. "There is a large body of folklore concerning the antibiotic, wound-healing, and clot-inducing activity of spider silk. However, much of that lore has not been seriously tested." The lore dates to the first century A.D. when spider webs were prized as wound dressings. They even found a place in Shakespeare's Midsummer Night's Dream: "I shall desire you of more acquaintance, good master cobweb," the character "Bottom" said. "If I cut my finger, I shall make bold of you".

The scanty scientific evidence is tantalizing, Lewis notes. He cites, for instance, animal studies concluding that spider silks do not induce an immune response -- which causes rejection of implants.........

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October 8, 2006, 5:48 PM CT

Marijuana's Ingredient May Slow Down Alzheimer's Disease

Scientists are reporting discovery in laboratory experiments of a previously unknown molecular mechanism in which the active ingredient in marijuana may slow the progression of Alzheimer's disease (AD). Scripps Research Institute's Kim D. Janda and colleagues used laboratory experiments to show that delta-9-tetrahydrocannabinol (THC) preserves brain levels of the key neurotransmitter acetylcholine.

Existing medications for AD, including donepezil and tacrine, also relieve AD symptoms by inhibiting the enzyme, acetylcholinesterase, which breaks down acetylcholine. THC does so by inhibiting an alternative site on acetylchlolinesterase and at lower concentrations, Janda's group reports in an article in the current (Oct. 2) issue of the ACS bimonthly journal, Molecular Pharmaceutics. Their experiments show that THC also prevents formation of the amyloid plaques that are a hallmark of AD and its damage to the brain.

"Our results provide a mechanism whereby the THC molecule can directly impact Alzheimer's disease pathology," they state. They also note that THC may provide a "drug lead" -- a model for developing new and more effective medications with more targeted effects on AD.

The researchers explain that such compounds "may provide an improved therapeutic for Alzheimer's disease, augmenting acetylcholine levels by preventing neurotransmitter degradation and reeducating amyloid beta aggregation, thereby simultaneously treating both the symptoms and progression of Alzheimer's disease".........

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October 3, 2006, 10:14 PM CT

Ultrafast Photochemical Reactions

MIT scientists have made a fundamental advance in understanding how different environments affect chemical reactions by devising a novel way to observe ultrafast photochemical reactions--reactions induced by a pulse of laser light--in crystals.

The new MIT experiments show that the reaction dynamics, including whether the product molecules remain or recombine to reform the original compound, depend with exquisite sensitivity on the local "cage" environment formed by neighboring molecules in the crystal. Cage effects of this sort play crucial roles in a number of natural and industrial chemical processes.

The method they have developed allows them to observe other light-induced changes in solids, including those used to burn CDs and DVDs. For some materials, these transitions may be reversible, allowing information to be both written and erased.

"This is a very active area of research for both fundamental and practical reasons," said Keith Nelson, MIT professor of chemistry and leader of the team. "What we're able to see, in a simple and direct way, is how different local environments around the reacting species lead to extremely different dynamics and different outcomes".

The work was reported in the Aug. 31 online issue of Science. Nelson's co-author on the paper is Peter Poulin, a former graduate student in his lab.........

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September 28, 2006, 9:25 PM CT

Improbable Buckyegg Hatched

An egg-shaped fullerene, or "buckyball egg" has been made and characterized by chemists at UC Davis, Virginia Tech and Emory and Henry College, Va. The unexpected discovery opens new possibilities for structures for fullerenes, which could have a wide range of uses.

"It was a total surprise," said Christine Beavers, a chemistry graduate student working with Professors Alan Balch and Marilyn Olmstead at UC Davis. Beavers is first author on the paper, published this month in the Journal of the American Chemical Society.

Fullerenes, sometimes called "buckyballs," are commonly spherical molecules of carbon, named after the futurist R. Buckminster Fuller, inventor of the geodesic dome. The carbon atoms are arranged in pentagons and hexagons, so their structures can resemble a soccer ball. An important rule -- until now -- is that no two pentagons can touch, but are always surrounded by hexagons.

The "buckyegg" compound was made by collaborating researchers at Virginia Tech, led by Professor Harry Dorn. They heated a mixture of carbon and other ingredients under special conditions to make a mixture of fullerenes, then shipped the products to UC Davis, where Balch's group worked on characterizing their structures.

When Beavers started to map out the structure, she found two pentagons next to each other, making the pointy end of the egg. Initially she thought that the results were a mistake, but she showed the data to Marilyn Olmstead, an expert on X-ray crystallography, and they decided that the results were real. The egg contains a molecule of triterbium nitride inside.........

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September 25, 2006, 10:04 PM CT

Better Sludge Through Metagenomics

Few stop to consider the consequences of their daily ablutions, the washing of clothes, the watering of lawns, and the flush of a toilet. However, wastewater therapy--one of the cornerstones of modern civilization--is the largest microbially-mediated biotechnology process on the planet. When it works, it is a microbial symphony in tune with humanity. When it fails, the consequences can be dire. Scientists from the U.S. Department of Energy Joint Genome Institute (DOE JGI) and collaborators at the University of Wisconsin-Madison, and the Advanced Wastewater Management Centre, University of Queensland, Australia, have published the first metagenomic study of an activated sludge wastewater therapy process. The research appeared online in the September 24 edition of the journal Nature Biotechnology (http://www.nature.com/nbt/journal/vaop/ncurrent/abs/nbt1247.html).

The metagenomic strategy entails generating DNA sequence information directly from samples of sewage sludge to provide a blueprint of the genes and hence the metabolic possibilities of the wastewater environment, with a view to understanding how the system works and predicting and averting failures or crashes.

"This is a first step in a much broader strategy employing a systems biology approach to the study of microbial communities with the goal of designing predictive models to understand how these communities function," said Hector Garcia Martin, lead author of the study and post-doctoral fellow in the DOE JGI's Microbial Ecology Program. "With this information now available, there are opportunities to bioengineer the process to make it more reliable."........

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September 24, 2006, 9:56 PM CT

Carbon Capture And Water Filtration

It's time to create a comprehensive accounting system for natural capital to recognize the full value of ecosystem services provided by boreal forests, an ecological economist will urge delegates to Canada's 10th National Forest Congress Sept. 25-27.

The forests' huge value as sinks and reservoirs of atmospheric carbon, for example, is unaccounted for today but needs to be recognized in future, as per Mark Anielski of Edmonton, who will make a presentation to Canadian and international forest officials, and experts from native peoples communities, the energy, farming and tourism sectors and other stakeholders assembling for the Congress at Lac Leamy, Gatineau-Ottawa.

Anielski and research colleagues estimate that environmental services from the boreal from climate regulation via carbon capture and storage, water filtration and waste therapy, to biodiversity maintenance, pest control by birds, etc. are worth about $160 per hectare, or $93 billion per year in Canada.

Globally, the estimates produce a rough value of ecosystem services rendered by boreal forests (almost 10 million northern square km spanning Canada, Russia, Sweden, Finland, Norway and Alaska) of US $250 billion per year, a huge figure unrecognized in national income accounts or measures such as Gross Domestic Product.........

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