A team of scientists has discovered a magnetic superatom ? a stable cluster of atoms that can mimic different elements of the periodic table ? that one day may be used to create molecular electronic devices for the next generation of faster computers with larger memory storage.
Self-Assembling
Sequence-Adaptive Peptide Nucleic Acids
Scripps research team creates simple chemical system that mimics
DNA. Findings offer possible clues about primordial world, and
could eventually lead to exotic new materials.
Small molecules mimic natural gene regulators
In the quest for new approaches to treating and preventing disease, one appealing route involves turning genes on or off at will, directly intervening in ailments such as cancer and diabetes, which result when genes fail to turn on and off as they should.
Methanogenesis
Nickel isotope may be methane producing microbe biomarker.
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ACS News:
Many floors in U. S. homes have "measurable"
levels of pesticides
Many floors in US homes have
measurable levels of pesticides, researchers say.
[Credit: Konrad A. Kociszewski,
Wikimedia Commons]
Insecticides used in and around homes - including
products voluntarily removed from the market years ago - were measured
on the floors of U.S. residences, according to the first study large
enough to generate national data on pesticide residues in homes. It is
scheduled for the June 15 issue of ACS' semi-monthly journal
Environmental Science & Technology.
Scientists at the U.S. Environmental Protection
Agency (EPA) and the U.S. Department of Housing and Urban Development
(HUD) collected samples with surface wipes from U.S. kitchen floors.
Additionally, occupants were surveyed regarding pesticide use and
housing factors. The most frequently detected pesticides, after
permethrin (89 percent), were chlorpyrifos (78 percent); chlordane (74
percent); piperonyl butoxide (52 percent); cypermethrin (46 percent);
and fipronil (40 percent). While in most cases, the pesticide
concentrations measured were low, the insecticides may serve as a
potential source of exposure to occupants.
Scientists launched the study to understand the
frequency and concentration of pesticide residues that might be found
in U.S. homes. EPA and HUD scientists plan to further investigate
these findings and the study's questionnaire results to explore the
relationships between pesticide concentrations found in homes and
housing factors (age of home, housing type, occupancy, etc.),
geographical location, pet treatments, and recent home pesticide
applications.
Milking microscopic algae could yield massive
amounts of oil
Scientists in Canada and India are proposing a
surprising new solution to the global energy crisis -"milking" oil
from the tiny, single-cell algae known as diatoms, renowned for their
intricate, beautifully sculpted shells that resemble fine lacework.
Their report appears online in the current issue of the ACS'
bi-monthly journal Industrial Engineering & Chemical Research.
Richard Gordon, T. V. Ramachandra, Durga Madhab
Mahapatra, and Karthick Band note that some geologists believe that
much of the world's crude oil originated in diatoms, which produce an
oily substance in their bodies. Barely one-third of a strand of hair
in diameter, diatoms flourish in enormous numbers in oceans and other
water sources. They die, drift to the seafloor, and deposit their
shells and oil into the sediments. Estimates suggest that live diatoms
could make 10-200 times as much oil per acre of cultivated area
compared to oil seeds, Gordon says.
"We propose ways of harvesting oil from diatoms,
using biochemical engineering and also a new solar panel approach that
utilizes genetically modifiable aspects of diatom biology, offering
the prospect of "milking" diatoms for sustainable energy by altering
them to actively secrete oil products," the scientists say. "Secretion
by and milking of diatoms may provide a way around the puzzle of how
to make algae that both grow quickly and have a very high oil content."
Study advises Chinese government to change fuel
in millions of households
Many homes in China use coal
briquettes for cooking and heating.
[Credit: Yingjun Chen, Chinese
Academy of Sciences]
Scientists in China are recommending that the
Chinese government consider phasing out the direct burning of
traditional chunks of coal in millions of households. It suggests that
the government substitute coal briquettes and improved stoves for
cooking and heating to help reduce the country's high air pollution
levels. The recommendation stems from one of the first scientific
studies showing that this approach is effective in improving air
quality, including a 98 percent reduction in air pollution from tiny,
inhalable particles of coal soot. Their study is scheduled for the
July 15 issue of ACS' Environmental Science & Technology, a
semi-monthly journal.
In the new study, Yingjun Chen and colleagues note
that government officials have said for years that coal briquettes and
improved stoves with better ventilation may cut emissions, but few
scientific studies have tested this claim. Millions of homes in rural
China and other parts of the world burn raw coal chunks in small,
low-efficiency stoves for cooking and heating. Studies indicate that
emissions from incomplete coal combustion in these stoves contribute
significantly to China's serious air pollution levels - among the
highest in the world.
The scientists compared emissions between
traditional and improved stoves using either raw (unprocessed) coal
chunks or coal briquettes. The briquettes consist of coal powder and
clay and are molded into multihole columns. They found that burning
briquettes in well-ventilated stoves dramatically reduced black carbon
emissions by 98 percent and other emissions by more than 60 percent.
The study concludes that this approach can bring about "explicit
benefits in environment and health, together with possible gains in
climate stabilization."
New evidence that vinegar may be natural
fat-fighter
Found in many salad dressings,
pickles, and other foods, vinegar could help prevent accumulation
of body fat and weight gain, scientists report.
[Credit: Wikipedia Commons]
Researchers in Japan are reporting new evidence
that the ordinary vinegar - a staple in oil-and-vinegar salad
dressings, pickles, and other foods - may live up to its age-old
reputation in folk medicine as a health promoter. They are reporting
new evidence that vinegar can help prevent accumulation of body fat
and weight gain. Their study is scheduled for the July 8 issue of ACS'
Journal of Agricultural and Food Chemistry, a bi-weekly publication.
Tomoo Kondo and colleagues note in the new study
that vinegar has also been used as a folk medicine since ancient times.
People have used it for a range of ills. Modern scientific research
suggests that acetic acid, the main component of vinegar, may help
control blood pressure, blood sugar levels, and fat accumulation.
Their new study showed that laboratory mice fed a
high-fat diet and given acetic acid developed significantly less body
fat (up to 10 percent less) than other mice. Importantly, the new
research adds evidence to the belief that acetic acid fights fat by
turning on genes for fatty acid oxidation enzymes. The genes churn out
proteins involved in breaking down fats, thus suppressing body fat
accumulation in the body.
No more test tubes on four feet? EPA moves
toward animal-free toxicity tests
The U.S. Environmental Protection Agency (EPA)
plans to switch to a new generation of animal-free tests for
predicting the toxicity of chemicals to humans, according to an
article scheduled for the June 22 issue of Chemical & Engineering
News, ACS' weekly newsmagazine.
C&EN associate editor Britt Erickson points out
that there are more than 80,000 chemicals on the market, with about
700 more added each year. Over the next ten years, EPA plans to
increasingly rely on so-called toxicity-based pathways to evaluate
these substances.
This approach involves using human cell cultures to
screen newly marketed chemicals for adverse effects. The new tests
will produce results in a fraction of the time now required with
animal studies.
But the switch won't be easy, the C&EN article
notes. Some experts question the validity of these next-generation
tests. Meanwhile, new technologies for predicting toxicity may emerge
and complement conventional animal tests, according to the article.
Toward an "electronic nose" to sniff out kidney
disease in exhaled breath
Scientists report advances toward
an "electronic nose" that could detect kidney disease.
[Credit: The American Chemical
Society]
Scientists in Israel have identified the key
substances in exhaled breath associated with healthy and diseased
kidneys - raising expectations, they say, for development of
long-sought diagnostic and screening tests that literally sniff out
chronic renal failure (CRF) in its earliest and most treatable stages.
Their report is in the current issue of ACS Nano, a monthly journal.
In the new study, Hossam Haick and colleagues point
out that the blood and urine tests now used to diagnose CRF can be
inaccurate and may come out "normal" even when patients have lost 75
percent of their kidney function. The most reliable test, a kidney
biopsy, is invasive and may result in infections and bleeding. Doctors
have long hoped for better tests for early detection of kidney disease.
The scientists describe tests of an experimental "electronic
nose" on exhaled breath of laboratory rats with no kidney function and
normal kidney function. The device identified 27 so-called volatile
organic compounds that appear only in the breath of rats with CRF. The
results presented in this study raise expectations for future
capabilities for diagnosis, detection, and screening various stages of
kidney disease," they said, noting that the tests could detect
patients with early disease who could be treated in ways that could
slow its progression.
New approach in the quest for lighting's Holy
Grail
Researchers have developed a new,
simpler white LED that shows promise as a more efficient and
stable source of pure white light for improved illumination of
homes and offices.
[Credit: The American Chemical
Society]
Researchers are reporting the first use of a
fundamentally new approach in the quest to snare the Holy Grail of the
lighting industry: An LED (light-emitting diode) - those
ultra-efficient, long-lived light sources - that emits pure white
light. The new approach yielded what the scientists describe as the
most efficient and stable source of pure white light ever achieved.
The advance could speed the development of this next-generation
technology for improved lighting of homes, offices, displays, and
other applications, they say. Their study appears in the May 29 online
issue of the Journal of the American Chemical Society, a weekly
publication.
Soo Young Park and colleagues note that white LEDs
show promise as a brighter, longer-lasting and more energy-efficient
light source than conventional lighting, such as incandescent and
fluorescent lights, which they may replace in the future. But
scientists have had difficulty producing white LEDs that are suitable
for practical use. Existing technologies produce tinted shades of
white light, require complex components, and become unstable over
time.
The researchers describe development of a new,
simpler white LED that is the first to achieve stable white light
emissions using a single molecule. Their specially engineered molecule
combines two light-emitting materials, one orange and one blue, which
together produce white light over the entire visible range. In
laboratory studies, the scientists showed that light production from
an LED using the new molecule was highly efficient and had excellent
color stability and reproducibility, features that make it a practical
white light source.
Reengineering a food poisoning microbe to carry
medicines and vaccines
Scientists have used genetic engineering to tame
one of the most deadly food poisoning microbes and turn it into a
potential new way of giving patients medicine and vaccines in pills
rather than injections. The study is in the current issue of ACS'
Molecular Pharmaceutics, a bi-monthly journal.
Colin Pouton and colleagues note that patients by
far prefer pills and capsules to the discomfort and inconvenience of
injections. But many medicines and vaccines cannot be given by mouth
because they would be destroyed by stomach acid without being absorbed
into the bloodstream. One promising approach is to use live bacteria,
which can survive those harsh conditions and pass easily from the GI
tract into the blood.
The scientists describe development of a new strain
of Listeria monocytogenes, bacteria that normally cause food poisoning,
but which have been genetically engineered to be harmless. Instead of
causing disease, the new microbes can be loaded with medicine or
vaccine, and deliver that beneficial cargo by "infecting" cells. After
entering cells, the bacteria burst and die, leading to Pouton's term "suicidal
strain" for the microbes. The researchers demonstrated that engineered
bacteria containing a test protein could successfully penetrate a
group of intestinal cells grown in the lab and deliver the protein
inside the cells while leaving the cells unharmed. The findings
suggest that the approach could potentially work in humans, the
researchers say.
New tests: Marijuana damages DNA and may cause
cancer
Using a highly sensitive new test, scientists in
Europe are reporting "convincing evidence" that marijuana smoke
damages the genetic material DNA in ways that could increase the risk
of cancer. Their study is scheduled for the June 15 issue of ACS'
Chemical Research in Toxicology, a monthly journal.
Rajinder Singh and colleagues note that toxic
substances in tobacco smoke can damage DNA and increase the risk of
lung and other cancers. However, there has been uncertainty over
whether marijuana smoke has the same effect. Scientists are especially
concerned about the toxicity of acetaldehyde, present in both tobacco
and marijuana. However, it has been difficult to measure DNA damage
from acetaldehyde with conventional tests.
The scientists describe development and use of a
modified mass spectrometry method that showed clear indications that
marijuana smoke damages DNA. "In conclusion, these results provide
evidence for the DNA damaging potential of cannabis [marijuana] smoke,
implying that the consumption of cannabis cigarettes may be
detrimental to human health with the possibility to initiate cancer
development," the article states. "The data obtained from this study
suggesting the DNA damaging potential of cannabis smoke highlight the
need for stringent regulation of the consumption of cannabis
cigarettes, thus limiting the development of adverse health effects
such as cancer."
Solar energy technology gets more
visually-appealing makeover
Those unsightly rooftop solar panels - hailed as
energy savers but often frowned upon as neighborhood eyesores - may
soon become a thing of the past, according to an article scheduled for
the June 15 issue of Chemical & Engineering News, ACS' weekly
newsmagazine. It foresees a new generation of unobtrusive or even
visually attractive solar panels that blend seamlessly into the
architecture of homes and business.
C&EN senior business editor Melody Voith notes that
scientists, engineers, and architects are developing new solar panels,
including materials that resemble normal shingles and invisible solar
films that can cover glass windows. There's a rapidly growing demand
for these so-called building-integrated photovoltaics, or BIPV, that
blend solar technology into the overall building aesthetic. One
estimate suggests that the market for BIPV will grow by 18 percent a
year through 2014, with revenues of about $780 million, according to
the article.
Japan and Europe are now the strongest markets for
BIPV. Sales are just beginning to rise in the United States,
especially in states like sunny California, which offers generous
subsidies for solar power. But several hurdles stand in the way of
further expansion of this new solar technology, including a need for
more efficient solar cells and demand for more durable and
cost-effective materials. Although buildings clad in nearly invisible
solar cells are mostly visions of the future, government incentives
and ongoing technology improvements could combine to make this dream a
widespread reality, the article suggests.
Compared with bottled wine, boxed
wine appears to have lower levels of certain chemicals that can
mask its fruity and floral taste, scientists report.
[Credit: Wikimedia Commons]
In a surprise discovery that may help boxed wine
shake off its image as a gauche alternative to bottles, scientists in
Canada are reporting that multilayer aseptic cartons (a.k.a. 'boxes')
may help reduce levels of substances that contribute odors to wine and
can lower its quality. Their study, the first comprehensive comparison
of packaging type to wine quality, is scheduled for the June 10 issue
of ACS' Journal of Agricultural and Food Chemistry, a bi-weekly
publication.
Gary Pickering and colleagues note that trace
amounts of chemicals called alkyl-methoxypyrazines (MPs) are generally
negative to wine quality, masking the desirable fruity and floral
flavors and giving wine an unpleasant green taste. With the wine
industry still searching for a way of reducing MP levels, the
scientists decided to look at the effects of wine packaging and
closures like corks and screw caps.
They added MPs to red and white wines and monitored
levels of MPs for 18 months in wine packaged in boxes and bottles with
natural cork, synthetic cork, or screw caps. Boxed wine had less MPs -
up to 45 percent less - than any other packaging. Bottles sealed with
synthetic cork and screw caps performed best, with natural corks
associated with the highest levels of MPs. One concern with the boxed
wine, however, was evidence of greater oxidation of the wine, which
itself is undesirable during wine storage.
A newly discovered chemical weapon in poison
frogs' arsenal
Scientists have discovered new
toxins that some Amazonian poison frogs use as a chemical defense
against predators.
[Credit: The American Chemical
Society]
New research documents a surprising chemical weapon
used by some Amazonian poison frogs. The study identified for the
first time a family of poisons never before known to exist in these
brightly colored creatures or elsewhere in nature: the
N-methyldecahydroquinolines. The authors then speculated on its origin
in the frogs' diet, most likely ants. The report is scheduled for the
June 26 issue of ACS' Journal of Natural Products, a monthly
publication.
H. Martin Garraffo and colleagues note there are
more than 500 alkaloids, potentially toxic substances, known to exist
in the skin of poison frogs of the family Dendrobatidae. Frogs use
them as a chemical defense to discourage predators from biting and
eating them. Western Colombian natives have used skin extracts from
another group of frogs, unrelated to those in the new study, to coat
blow-darts for hunting.
Frogs get nearly all of the alkaloids from their
diet, removing alkaloids from ants, mites, small beetles, millipedes
and possibly other small arthropods, concentrating them with
incredible efficiency, and storing them in their skin. However,
Garraffo's group was not certain about the origin of the newly
discovered N-methyldecahydroquinolines, which could also be produced
in the frogs' own bodies. Feeding experiments with alkaloids fed to
captive frogs are planned, which might settle this point.
The scientists analyzed alkaloids from the skin of
13 of the more than 25 species of the genus Ameerega of poison frogs.
They identified the new toxins in the frogs as being of the
N-methyldecahydroquinoline class, which were present among several
other alkaloids.
Overcoming non-scientific barriers to making
sustainability a reality
With sustainability emerging as a top priority for
businesses and industries, a workshop of 40 experts has identified and
published a set of recommendations for businesses to overcome the
nontechnical barriers to applying sustainable industrial practices.
Their article is scheduled for the June 15 issue of ACS' Environmental
Science & Technology, a semi-monthly journal.
In the article, Martin A. Abraham and colleagues
point out that important scientific, or technical, advances are
occurring in green chemistry and green engineering. These enable
industry to embrace more environmentally friendly processes that
minimize the use of potentially toxic substances, for instance, and
produce less waste. Despite such technical advances, other barriers to
implementing sustainable practices remain.
The American Chemical Society and the American
Institute of Chemical Engineers convened the workshop to identify
approaches for overcoming these nontechnical hurdles to implementing
sustainability ? often defined as the ability to meet present needs
without compromising those of future generations. The group identified
five major approaches to overcoming barriers, which include economic,
regulatory, educational and cultural factors. One, for instance,
involves a shift in mindset in which business executives view
sustainability not just as regulatory compliance but as a pathway to
innovation.
Scientists found a group of molecules that act
like an "on-off switch" and could be used to develop medicines
against various diseases.
[Credit: The American Chemical Society]
Scientists in Michigan and California are reporting
an advance toward development of a new generation of drugs that treat
disease by orchestrating how genes in the body produce proteins
involved in arthritis, cancer and a range of other disorders. Acting
like an "on-off switch," the medications might ratchet up the
production of proteins in genes working at abnormally low levels or
shut off genes producing an abnormal protein linked to disease. Their
report is in the current issue of ACS Chemical Biology, a monthly
journal.
In the study, Anna K. Mapp and colleagues discusses
molecules that cause genes to be active and churn out proteins -
so-called transcriptional activators. That's because they control a
key process known as transcription, in which instructions coded in
genes produce proteins. Malfunctions in these activators could lead to
altered transcription patterns that lead to disease. For example,
variations in the tumor suppressor gene p53 are found in more than
half of all human cancers.
Mapp describes discovery of a group of molecules
that could be used to help scientists better understand transcription.
Known as activator artificial transcriptional activation domains,
these small molecules mimic natural activators and could provide
insights on how mistakes in gene regulation result in various diseases.
"Evidence suggests that these small molecules mimic the function and
mechanism of their natural counterparts and present a framework for
the broader development of small molecule transcriptional switches,"
Mapp states.
Growing demand for certain metals creates new
push for sustainability
Growing demand for certain metals used in
automotive catalytic converters, computers, and other widely-used
products - combined with a limited supply - is fostering a quest for
ways to apply the principles of sustainability to humanity's use of
metals. That's the topic of an article on sustainability - the effort
to meet the needs of society today without compromising the ability of
future generations to meet their own needs - scheduled for the June 8
issue of Chemical & Engineering News, ACS' weekly newsmagazine.
C&EN senior editor Steve Ritter explains that
metals are limited natural resources, just like crude oil and fresh
water. He described copper, zinc, platinum, and certain other metals
as "endangered species," which could be depleted by the end of this
century. That's because such metals are being used faster than they
can be replenished through recycling.
Proposed solutions for making the use of metals
sustainable include smarter design of consumer products so that people
can more easily recycle and use the metal content. Other solutions
involve encouraging companies to adapt more efficient recycling
strategies and providing more financial incentives to encourage people
to recycle. Other possibilities include mining new sources of metals,
such as those found in metal sulfide deposits near deep-sea
hydrothermal vents or manganese nodules found in deep-sea sediments.
While such innovative mining approaches are expensive and not
practical today, new technology may enable their use in the future,
the article suggests.
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