Photoelectrochemical Complexes for Solar Energy Conversion
MIT researchers create new self-assembling photovoltaic technology that repairs itself. Molecules can turn sunlight into electricity & can be broken down and quickly reassembled.
MIT moves toward greener chemistry: Breaking up phosphorus with ultraviolet light may offer a safer, simpler way to build many industrial and household chemicals.
Transition metal catalysts could be key to origin of life, scientists report.
Researchers propose that structures like this could have catalyzed the formation of molecular building blocks, leading ultimately to the formation of complex molecules essential for the origin of life [Credit: Harold Morowitz, George Mason University].
Researchers Discover Proton Diode
Biophysicists in Bochum have discovered a diode for protons: just like the electronic component determines the direction of flow of electric current, the ?proton diode? ensures that protons can only pass through a cell membrane in one direction. Water molecules play an important role here as active components of the diode.
Hot Water in Cold Comets: An international research team recently succeeded deciphering an important aspect of the way by which water molecules often form in space.
Image:
Breakup on three pathways. A hydronium ion captures an
electron and can then split into different combinations
of fragments.
Edible nanostructures: Compounds made from renewable materials could be used for gas storage, food technologies.
Sugar, salt, alcohol and a little serendipity led a Northwestern University research team to discover a new class of nanostructures that could be used for gas storage and food and medical technologies. And the compounds are edible.
[Image credit: Angewandte Chemie, DOI
10.1002/anie.201002343]
Garlic oil shows protective effect against heart disease
in diabetes
Garlic has "significant"
potential for preventing cardiomyopathy, a form of heart
disease that is a leading cause of death in people with
diabetes, scientists have concluded in a new study. Their
report, which also explains why people with diabetes are at
high risk for diabetic cardiomyopathy, appears in ACS'
bi-weekly Journal of Agricultural and Food Chemistry.
Wei-Wen Kuo and
colleagues note that people with diabetes have at least
twice the risk of death from heart disease as others, with
heart disease accounting for 80 percent of all
diabetes-related deaths. They are especially vulnerable to a
form of heart disease termed diabetic cardiomyopathy, which
inflames and weakens the heart's muscle tissue. Kuo's group
had hints from past studies that garlic might protect
against heart disease in general and also help control the
abnormally high blood sugar levels that occur in diabetes.
But they realized that few studies had been done
specifically on garlic's effects on diabetic cardiomyopathy.
The scientists fed either
garlic oil or corn oil to laboratory rats with diabetes.
Animals given garlic oil experienced beneficial changes
associated with protection against heart damage. The changes
appeared to be associated with the potent antioxidant
properties of garlic oil, the scientists say, adding that
they identified more than 20 substances in garlic oil that
may contribute to the effect. "In conclusion, garlic oil
possesses significant potential for protecting hearts from
diabetes-induced cardiomyopathy," the report notes.
Simple approach could clean up oil remaining from Exxon
Valdez spill
Traces of crude oil that
linger on the shores of Alaska's Prince William Sound after
the Exxon Valdez oil spill remain highly biodegradable,
despite almost 20 years of weathering and decomposition,
scientists are reporting in a new study. Their findings,
which appear in ACS' semi-monthly journal Environmental
Science & Technology, suggest a simple approach for further
cleaning up remaining traces of the Exxon Valdez spill - the
largest in U.S. waters until the 2010 Deepwater Horizon
episode.
Albert D. Venosa and
colleagues note that bacteria, evaporation, sunlight, and
other items in Mother's Nature's clean-up kit work together
to break down the oil and make it disappear. Scientists have
known for years that adding nitrogen and phosphorus
fertilizer to oil-contaminated soil can speed the growth of
bacteria that decompose, or biodegrade, oil. But it has been
uncertain whether oil that has lingered in the environment
for almost 20 years still is biodegradable, leaving
questions on whether further clean-up efforts might be
worthwhile.
The scientists collected
oil-contaminated soil from different beaches in Prince
William Sound and treated the samples with phosphorus and
nitrogen fertilizer in the presence of excess oxygen from
the air. Oil in the fertilized samples biodegraded up to
twice as fast as oil in the unfertilized control samples,
but significant biodegradation occurred even in the
unfertilized controls. The results showed that oxygen supply
was the major bottleneck, or limiting factor, in the field
that prevented further decomposition of the oil. The
scientists used data from the research to postulate a simple
treatment scheme that would involve applying simple nitrate
salts to possibly break down the natural organic matter in
the sediment. That would cause an increase in sediment
porosity that would allow dissolved oxygen in seawater to
penetrate to the oiled zone and create oxygen-rich
conditions that might stimulate more rapid biodegradation.
Ingredient in soap points toward new drugs for infection that affects 2 billion
The antibacterial ingredient in some soaps, toothpastes, odor-fighting socks, and even computer keyboards is pointing scientists toward a long-sought new treatment for a parasitic disease that affects almost two billion people. Their report on how triclosan became the guiding light for future development of drugs for toxoplasmosis appears in ACS' monthly Journal of Medicinal Chemistry.
In the study, Rima McLeod and colleagues point out that toxoplasmosis is one of the world's most common parasitic infections, affecting about one-third of the world population, including 80 percent of the population of Brazil. People can catch the infection, spread by the parasite Toxoplasma gondii (T. gondii), from contact with feces from infected cats, eating raw or undercooked meat, and in other ways. Many have no symptoms because their immune systems keep the infection under control and the parasite remains inactive. But it can cause eye damage and other problems, even becoming life threatening in individuals with immune systems weakened by certain medications and diseases like HIV infection, which allow the parasite to become active again, and in some persons without immune compromise. Most current treatments have some potentially harmful side effects and none of them attack the parasite in its inactive stage.
The scientists knew from past research that triclosan has a powerful effect in blocking the action of a key enzyme that T. gondii uses to live. Triclosan, however, cannot be used as a medication because it does not dissolve in the blood. The scientists describe using triclosan's molecular structure as the model for developing other potential medications, including some that show promise as more effective treatments for the disease.
Low levels of formaldehyde
in clothing unlikely to pose health risk
The formaldehyde added to fabrics
to keep clothing looking fresh and wrinkle-free is unlikely to pose a
health risk to consumers, according to an article in the current issue
of Chemical & Engineering News (C&EN), ACS' weekly newsmagazine.
C&EN Senior Correspondent David J.
Hanson notes that manufacturers have added formaldehyde to fabrics for
almost a hundred years to make fabrics easier to care for,
particularly to reduce wrinkling in cotton and prevent stains. But
concern has emerged over formaldehyde's potential for causing allergic
reactions such as skin rashes in some people. Formaldehyde also is a
potential human carcinogen.
The article describes a new
analysis of formaldehyde levels in clothing and the potential health
risks. The analysis found that formaldehyde levels in clothing have
fallen significantly over the past 25 years. In 1984, for instance, 67
percent of fabrics tested in government studies had levels greater
than 100 parts per million, a level the textile industry considers
high. But since 2003, less than two percent of items tested showed
such high levels and most clothing items had nondetectable levels, the
article says, noting that the health risk from formaldehyde is likely
very small.
Chemical & Engineering News: "Formaldehyde
in Clothing" [C&EN, Volume 88, Number 36; September 6, 2010; DOI:
10.1021/CEN083110114827].
Questioning the safety of certain 'healthful'
plant-based antioxidants
Scientists are calling for more research on the
possibility that some supposedly healthful plant-based antioxidants
- including those renowned for their apparent
ability to prevent cancer ? may actually aggravate or even cause
cancer in some individuals. Their recommendation follows a study in
which two such antioxidants - quercetin and
ferulic acid - appeared to aggravate kidney
cancer in severely diabetic laboratory rats. The study appears in ACS'
bi-weekly Journal of Agricultural and Food Chemistry.
Kuan-Chou Chen, Robert Peng, and colleagues note
that vegetables, fruits, and other plant-based foods are rich in
antioxidants that appear to fight cancer, diabetes, heart disease, and
other disorders. Among those antioxidants is quercetin, especially
abundant in onions and black tea, and ferulic acid, found in corn,
tomatoes, and rice bran. Both also are ingredients in certain herbal
remedies and dietary supplements. But questions remain about the
safety and effectiveness of some antioxidants, with research
suggesting that quercetin could contribute to the development of
cancer, the scientists note.
They found that diabetic laboratory rats fed either
quercetin or ferulic acid developed more advanced forms of kidney
cancer, and concluded the two antioxidants appear to aggravate or
possibly cause kidney cancer. "Some researchers believe that quercetin
should not be used by healthy people for prevention until it can be
shown that quercetin does not itself cause cancer," the report states.
"In this study we report that quercetin aggravated, at least, if not
directly caused, kidney cancer in rats," it adds, suggesting that
health agencies like the U. S. Food and Drug Administration should
reevaluate the safety of plant-based antioxidants.
Eyes of cattle may become new windows to detect
mad cow disease
The eyes may or may not be windows
to the soul, as the old adage goes, but scientists are reporting
evidence that a peek into the eyes of cattle may become the basis for
a long-sought test to detect infection with the agent that causes Mad
Cow Disease. That test could help prevent the disease from spreading
in the food supply. A study on using the tell-tale glow given off by
eyes infected with the Mad Cow agent appears in ACS' semi-monthly
journal Analytical Chemistry.
Jacob Petrich and colleagues note
that the human form of Mad Cow Disease is linked to eating beef from
animals infected with abnormal proteins called prions implicated in a
range of brain diseases. Scientists are trying to develop tests to
detect infected cattle before they enter the food supply. Past studies
suggest that chemical changes in an animal's retina, the light
sensitive nerve tissue in the back of the eye, may provide a basis for
detecting prion diseases.
The scientists showed that retinas
of sheep infected with scrapie, a disease similar to Mad Cow Disease,
emit a characteristic glow when examined with a beam of light from a
special instrument. They suggest that eye tests based on the finding
could become important in the future for fast, inexpensive diagnosis
of prion diseases and other neurological diseases.
New American Chemical Society
podcast: Economical biodiesel from sewage sludge
WASHINGTON, Sept. 8, 2010 -
Biodiesel fuel could be produced from municipal sewage sludge at a
cost that is within a few cents a gallon of being competitive with
conventional diesel refined from petroleum, according to the latest
episode in the American Chemical Society's (ACS) award-winning podcast
series, "Global
Challenges/Chemistry Solutions."
To boost biodiesel production,
sewage treatment plants could use microorganisms that produce higher
amounts of oil, says study leader David M. Kargbo, Ph.D., with the U.
S. Environmental Protection Agency (EPA).That step alone could
increase biodiesel production to the 10 billion gallon mark, which is
more than triple the nation's current biodiesel production capacity,
he reports.
Kargbo points out in the podcast
that demand for biodiesel has led to the search for cost-effective
biodiesel feedstocks, or raw materials. Soybeans, sunflower seeds and
other food crops have been used as raw materials but are expensive.
Sewage sludge is an attractive alternative feedstock ? the United
States alone produces about seven million tons of it each year. Sludge
is a good source of raw materials for biodiesel.
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