Tin-Sulfur-Lithium-Ion Battery
More power, longer life, increased safety: Tin-sulfur-lithium-ion battery as alternative to conventional lithium batteries.
Photo-inactivation of Proteins
Light-activated 'warhead' turns modest molecules into super protein killers: Novel research tool from Scripps Florida could significantly expand search for new therapies.
A Phytochemical Atlas of Arabidopsis Thaliana
All natural ingredients. A catalog of the chemicals produced within a plant?s tissues yields fresh insights into its metabolic pathways and gene function.
Chemical Ecology
Smelling the Scenery in Stereo. Desert ants perceive odour maps in stereo and use this information for navigation.
Molecular Evolution
Unselfish molecules may have helped give birth to the genetic material of life.
Effective imitation: chitinase inhibition by chitobiose and chitotriose thiazolines.
Image:
Di- and trisaccharide analogues of the oxazoline intermediate formed during enzymatic hydrolysis of chitin were found to be potent inhibitors of chitinase A [Credit: Angewandte Chemie, Wiley-VCH].
DNA Repair
Mouse work: New insights on a fundamental DNA repair mechanism.
Synthetic Sea Shells
Scientists have made synthetic ?sea shells? from a mixture of chalk and polystyrene cups - and produced a tough new material that could make our homes and offices more durable.
Rice researchers make graphene hybrid. One-atom-thick sheet offers new microelectronic possibilities.
Image:
A one-atom-thick layer of a graphene and boron nitride hybrid is visible to the naked eye when deposited on a glass slide [credit: Rice University/Ajayan Lab].
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More News (open access):
Proteins in unroasted coffee beans may become
next-generation insecticides
Unroasted coffee beans contain
proteins that kill insects, a finding that may lead to new
insecticides for protecting food crops.
[Credit: Fernando Rebelo,
Wikimedia Commons]
Scientists in Brazil are reporting for the first
time that coffee beans contain proteins that can kill insects and
might be developed into new insecticides for protecting food crops
against destructive pests. Their study, which suggests a new use for
one of the most important tropical crops in the world, appears in ACS'
Journal of Agricultural and Food Chemistry, a bi-weekly publication.
Peas, beans and some other plant seeds contain
proteins, called globulins, which ward off insects. Coffee beans
contain large amounts of globulins, and Paulo Mazzafera and colleagues
wondered whether those coffee proteins might also have an insecticidal
effect. The high heat of roasting destroys globulins, so that they do
not appear in brewed coffee.
Their tests against cowpea weevil larva, insects
used as models for studying the insecticidal activity of proteins,
showed that tiny amounts of the coffee proteins quickly killed up to
half of the insects. In the future, scientists could insert genes for
these insect-killing proteins into important food crops, such as
grains, so that plants produce their own insecticides, the researchers
suggest. The proteins appear harmless to people.
Diet of contaminated insects harms endangered
meat-eating plants
The worldwide decline of
meat-eating plants, like those shown here, may be due to the
plants? consumption of insects contaminated with toxic metals.
[Credit: iStock]
Scientists in the United Kingdom are reporting
evidence that consumption of insects contaminated with a toxic metal
may be a factor in the mysterious global decline of meat-eating, or
carnivorous, plants. Their study describes how meals of contaminated
insects have adverse effects on the plants. It appears in ACS'
semi-monthly journal Environmental Science & Technology.
Iain Green and Christopher Moody note that many
species of carnivorous plants - which have the amazing ability to
lure, trap and digest insects - have become endangered through habitat
loss, illegal poaching, and pollution. One potential threat to these
meat-eating plants is exposure to insect prey contaminated with
certain metals, which can harm plants by interfering with water and
nutrient uptake. However, scientists know little about how such metals
actually affect the plants. Two metals of particular concern are
copper, a nutrient important for plant health, and cadmium, a toxic
metal found in fertilizers, metal coatings, and other products. It can
accumulate in the environment through improper waste disposal.
They fed contaminated house fly maggots to a group
of endangered white-topped pitcher plants (Sarracenia leucophylla) and
found that cadmium accumulated in the plants' stems in a way that can
be toxic and disrupt growth. By contrast, the plants easily processed
and controlled copper intake and the metal did not appear to cause any
toxic effects, the scientists say. The findings emphasize the
importance of limiting carnivorous plants' exposure to cadmium, they
suggest.
American industry's thirst for water: First study
of its kind in 30 years
Manufacturers, farmers, shippers
and others in the "supply chain" use almost 270 gallons of water
to put $1 worth of sugar on supermarket shelves, according to a
new study documenting American industry?s water use.
[Credit: iStock]
How many gallons of water does it take to produce
$1 worth of sugar, dog and cat food, or milk? The answers appear in
the first comprehensive study in 30 years documenting American
industry's thirst for this precious resource. The study, which could
lead to better ways to conserve water, is in ACS' Environmental
Science & Technology, a semi-monthly journal.
Chris Hendrickson and colleagues note in the new
study that industry (including agriculture) long has been recognized
as the biggest consumer of water in the United States. However,
estimates of water consumption on an industry-by-industry basis are
incomplete and outdated, with the last figures from the U.S. Census
Bureau dating to 1982.
They estimated water use among more than 400
industry sectors - from finished products to services - using a
special computer model. The new data shows that most water use by
industry occurs indirectly as a result of processing, such as
packaging and shipping food crops to the supermarket, rather than
direct use, such as watering crops. Among the findings for consumer
products: It takes almost 270 gallons of water to produce $1 worth of
sugar; 200 gallons of water to make $1 worth of dog and cat food; and
140 gallons of water to make $1 worth of milk. "The study gives a way
to look at how we might use water more efficiently and allows us to
hone in on the sectors that use the most water so we can start
generating ideas and technologies for better management," the
scientists note.
Nitric oxide-releasing wrap for donor organs and
cloth for therapeutic socks
Porous materials termed zeolites,
incorporated into this cloth, point the way to therapeutic
bandages and wraps that can deliver healing nitric oxide.
Credit: American Chemical Society
Scientists in Texas are reporting development of a
first-of-its-kind cloth that releases nitric oxide gas - an advance
toward making therapeutic socks for people with diabetes and a wrap to
help preserve organs harvested for transplantation. The study is in
ACS' Chemistry of Materials, a bi-weekly journal.
Kenneth Balkus and Harvey Liu note in the new study
that nitric oxide (NO) helps increase blood flow and regulates a range
of other body functions. Scientists have tried for years to find
practical ways to store and deliver NO for use in medicine. However,
they have had difficulty finding a suitable material that allows
controlled delivery of NO. Recent studies suggested that zeolites
could work. These porous materials soak up and store large amounts of
gases like NO.
The scientists describe development of a new
bandage composed of nitric oxide-absorbing zeolites embedded in a
special water-repellant polymer. In experiments with laboratory rats,
the bandage slowly released nitric oxide and increased blood flow.
"The bandage could be used to wrap a donor organ ensuring intimate
contact and direct delivery of nitric oxide," the report states.
"Additionally, these interwoven fabrics could also find applications
in smart textiles such as NO-releasing socks for diabetic patients,
who have been shown to produce less nitric oxide than healthy
patients."
A huge step toward mass production of coveted form
of carbon
This graphic represents an
atom-thin sheet of graphene, a form of carbon that could replace
silicon in future electronic devices. Scientists have developed a
simple manufacturing method that could allow its mass production.
[Credit: Wikimedia Commons]
Scientists have leaped over a major hurdle in
efforts to begin commercial production of a form of carbon that could
rival silicon in its potential for revolutionizing electronics devices
ranging from supercomputers to cell phones. Called graphene, the
material consists of a layer of graphite 50,000 times thinner than a
human hair with unique electronic properties. Their study appears in
ACS' Nano Letters, a monthly journal.
Victor Aristov and colleagues indicate that
graphene has the potential to replace silicon in high-speed computer
processors and other devices. Standing in the way, however, are
today's cumbersome, expensive production methods, which result in
poor-quality graphene and are not practical for industrial scale
applications.
Aristov and colleagues report that they have
developed "a very simple procedure for making graphene on the cheap."
They describe growing high-quality graphene on the surface of
commercially available silicon carbide wafers to produce material with
excellent electronic properties. It "represents a huge step toward
technological application of this material as the synthesis is
compatible with industrial mass production," their report notes.
NoMix toilets get thumbs-up in 7 European
countries
'NoMix' toilets, like the one
shown here, collect urine and feces separately. They have gained
wide support by consumers in Europe as a way to reduce pollution
and conserve water.
[Credit: Yvonne Lehnhard]
People in seven European countries have positive
attitudes toward a new eco-friendly toilet that could substantially
reduce pollution problems and conserve water and nutrients, scientists
in Switzerland are reporting. Their article, which calls on
authorities to give wider support for the innovative toilet
technology, is in ACS' Environmental Science & Technology, a
semi-monthly journal.
Judit Lienert and Tove Larsen note in the article
that the so-called NoMix toilet collects urine separately instead of
mixing it together with feces as in conventional toilets. Urine
contains 80 percent of the nitrogen and 50 percent of the phosphorus
arriving at wastewater treatment plants. Separating it in advance
could have a number of advantages. This includes a reduction in the
amount of nitrogen and phosphorous nutrients that trigger algae blooms
and in pharmaceutical residues, which can enter waterways and pose a
threat to fish. Separating urine also allows its use as an
agricultural fertilizer, the scientists note. However, scientists have
not widely explored public attitudes about using this promising
technology until now.
The scientists reviewed surveys on acceptance and
use of NoMix toilets among seven European countries with responses
from 2700 people. Those countries were Switzerland, Germany, Austria,
Luxembourg, The Netherlands, Sweden, and Denmark. The researchers
found that the technology is well-accepted, with about 80 percent of
users expressing support of the idea, with many willing to use it at
work or at home. Between 75 to 85 percent of the users found that the
design, hygiene, smell and seating comfort of the NoMix toilets equals
that of conventional toilets. About 85 percent of users were open to
the idea of using stored urine as fertilizer. "No Mix-technology
deserves more support by authorities and mainstream research," the
article notes.
World crude oil production may peak a decade
earlier than some predict
The world's crude oil production,
which comes from sources like this oil field, may peak a decade
earlier than some scientists had predicted.
[Credit: iStock]
In a finding that may speed efforts to conserve oil
and intensify the search for alternative fuel sources, scientists in
Kuwait predict that world conventional crude oil production will peak
in 2014 - almost a decade earlier than some other predictions. Their
study is in ACS' Energy & Fuels, a bi-monthly journal.
Ibrahim Nashawi and colleagues point out that rapid
growth in global oil consumption has sparked a growing interest in
predicting "peak oil" - the point where oil production reaches a
maximum and then declines. Scientists have developed several models to
forecast this point, and some put the date at 2020 or later. One of
the most famous forecast models, called the Hubbert model, accurately
predicted that oil production would peak in the United States in 1970.
The model has since gained in popularity and has been used to forecast
oil production worldwide. However, recent studies show that the model
is insufficient to account for more complex oil production cycles of
some countries. Those cycles can be heavily influenced by technology
changes, politics, and other factors, the scientists say.
The new study describe development of a new version
of the Hubbert model that accounts for these individual production
trends to provide a more realistic and accurate oil production
forecast. Using the new model, the scientists evaluated the oil
production trends of 47 major oil-producing countries, which supply
most of the world's conventional crude oil. They estimated that
worldwide conventional crude oil production will peak in 2014, years
earlier than anticipated. The scientists also showed that the world's
oil reserves are being depleted at a rate of 2.1 percent a year. The
new model could help inform energy-related decisions and public policy
debate, they suggest.
Chemicals that eased one environmental problem may
worsen another
Forests are being damaged by acid
rain, which contains a corrosive ingredient that may result from
the breakdown of chemicals introduced to help protect Earth's
ozone layer.
[Credit: Wikimedia Commons]
Chemicals that helped solve a global environmental
crisis in the 1990s - the hole in Earth's protective ozone layer - may
be making another problem - acid rain - worse, scientists are
reporting. Their study on the chemicals that replaced the
ozone-destroying chlorofluorocarbons (CFCs) once used in aerosol spray
cans, air conditioners, refrigerators, and other products, appears in
ACS' Journal of Physical Chemistry A, a weekly publication.
Jeffrey Gaffney, Carrie J. Christiansen, Shakeel S.
Dalal, Alexander M. Mebel and Joseph S. Francisco point out that
hydrochlorofluorocarbons (HCFCs) emerged as CFC replacements because
they do not damage the ozone layer. However, studies later suggested
the need for a replacement for the replacements, showing that HCFCs
act like super greenhouse gases, 4,500 times more potent than carbon
dioxide. The new study adds to those concerns, raising the possibility
that HCFCs may break down in the atmosphere to form oxalic acid, one
of the culprits in acid rain.
They used a computer model to show how HCFCs could
form oxalic acid via a series of chemical reactions high in the
atmosphere. The model, they suggest, could have broader uses in
helping to determine whether replacements for the replacements are as
eco-friendly as they appear before manufacturers spend billions of
dollars in marketing them.
Soil contains microbes that are
increasingly resistant to antibiotics, a finding that could have
broad consequences to public health.
[Credit: iStock]
A team of scientists in the United Kingdom and the
Netherlands are reporting disturbing evidence that soil microbes have
become progressively more resistant to antibiotics over the last 60
years. Surprisingly, this trend continues despite apparent more
stringent rules on use of antibiotics in medicine and agriculture, and
improved sewage treatment technology that broadly improves water
quality in surrounding environments. Their report appears in ACS'
bi-weekly journal Environmental Science and Technology.
David Graham and colleagues note that, although
scientists have known for years that resistance was increasing in
clinical situations, this is the first study to quantify the same
problem in the natural environment over long time-scales. They express
concern that increased antibiotic resistance in soils could have broad
consequences to public health through potential exposure through water
and food supplies. Their results "imply there may be a progressively
increasing chance of encountering organisms in nature that are
resistant to antimicrobial therapy."
The study involved an analysis of 18 different
antibiotic resistance genes (ARGs) to four different classes of
antibiotics in soil samples collected in the Netherlands from 1940 to
2008. ARGs are genes chosen to assess potential changes in resistance
in microbes. Using data from sites around the Netherlands, the
scientists found increasing levels in 78 percent of the ARG tested,
clearly indicating increased potential for resistance over time.
Because soil samples were only collected from the Netherlands, the
scientists conclude their report by suggesting that further studies
need be performed around the world so that the scope and possible
ramifications of their results can be better understood.
Supermarket lighting enhances nutrient level of
fresh spinach
Spinach on display under 24-hour
light in supermarkets actually gains in content of some nutrients.
[Credit: Marc Villalobos, USDA-ARS]
Far from being a food spoiler, the fluorescent
lighting in supermarkets actually can boost the nutritional value of
fresh spinach, scientists are reporting. The finding could lead to
improved ways of preserving and enhancing the nutritional value of
spinach and perhaps other veggies, they suggest in a study in ACS'
bi-weekly Journal of Agricultural and Food Chemistry.
Gene Lester, Donald J. Makus, and D. Mark Hodges
note that fresh spinach is a nutritional powerhouse, packed with
vitamin C, vitamin E, folate (a B vitamin), and healthful carotenoid
antioxidants. Supermarkets often display fresh spinach in clear
plastic containers at around 39 degrees Fahrenheit in showcases that
may be exposed to fluorescent light 24 hours a day. Lester, Makus, and
Hodges wondered how this continuous light exposure might affect
spinach's nutritional value.
The scientists exposed fresh spinach leaves to
continuous light or darkness during simulated retail storage
conditions for three to nine days. Spinach stored in light for as
little as three days had significantly higher levels of vitamins C, K,
E, and folate. They also had higher levels of the healthful
carotenoids (plant pigments) lutein and zeaxanthin. During continuous
light exposure after nine days, levels of folate increased between 84
and 100 percent, for instance. Levels of vitamin K increased between
50 and 100 percent, depending on the spinach variety tested. By
contrast, spinach leaves stored under continuous darkness tended to
have declining or unchanged levels of nutrients, the scientists say.
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