Genetic �telepathy�? A bizarre new property of
DNA
Scientists are reporting evidence that intact,
double-stranded DNA has the �amazing� ability to recognize
similarities in other DNA strands from a distance. And then like
friends with similar interests, the bits of genetic material hangout
or congregate together. The recognition - of similar sequences in
DNA�s chemical subunits - occurs in a way once regarded as impossible,
the researchers suggest in a study scheduled for the Jan. 31 issue of
ACS� Journal of Physical Chemistry B.
Geoff S. Baldwin, Sergey Leikin, John M. Seddon,
and Alexei A. Kornyshev and colleagues say the homology recognition
between sequences of several hundred nucleotides occurs without
physical contact or presence of proteins, factors once regarded as
essential for the phenomenon. This recognition may help increase the
accuracy and efficiency of the homologous recombination of genes - a
process responsible for DNA repair, evolution, and genetic diversity.
The new findings thus may shed light on ways to avoid recombination
errors, which underpin cancer, aging, and other health problems.
In the study, scientists observed the behavior of
fluorescently tagged DNA strands placed in water that contained no
proteins or other material that could interfere with the experiment.
Strands with identical nucleotide sequences were about twice as likely
to gather together as DNA strands with different sequences.
�Amazingly, the forces responsible for the sequence recognition can
reach across more than one nanometer of water separating the surfaces
of the nearest neighbor DNA,� said the authors. - AD
Secret of the carnivorous pitcher plant's slurp
- solved at last
Scientists have deciphered the
complex cocktail of digestive and antibacterial enzymes of the
carnivorous pitcher plant.
Image: Courtesy of Tatsuro Hamada,
Ishikawa Prefectural University, Japan
Splash! Ooch! Yum! And so another unsuspecting
insect victim of Nepenthes alata (N. alata), commonly known as the
carnivorous pitcher plant, falls victim to the digestive fluids at the
bottom of the plant's famous cup-shaped leaf. For almost a century,
scientists have sought the full chemical recipe for the pitcher
plant's fluid. Japanese scientists now report completely deciphering
this complex cocktail of digestive and antibacterial enzymes. Their
study is scheduled for the February issue of ACS� Journal of Proteome
Research, a monthly publication.
Unlike other plants that absorb nutrients from the
soil, carnivorous plants growing in nutrient-poor soils have special
organs to capture insects, digest them and absorb the nitrogen and
phosphorous their environment sorely lacks. The identity of all the
myriad proteins involved in this evolutionary marvel - some of which
could have beneficial applications in medicine and agriculture - has
been a mystery until now.
Tatsuro Hamada and Naoya Hatano used cutting-edge
proteomic analysis to identify all of the components. They isolated
and sequenced the proteins, then compared each with existing proteins
to find structural matches. Hamada and Hatano detected seven proteins
that exist mainly in the pitcher fluid of N. alata - three of which
can only be found in this species - including useful enzymes that may
inhibit bacterial growth and rotting as the plant slowly digests its
prey. - AD
Toward a cleaner, more effective method for
destroying hormone-like pollutants in wastewater
Researchers report effectiveness of a powerful,
environmentally-friendly catalyst in destruction of various estrogens
that currently escape complete removal in our wastewater treatment
plants. Their study is scheduled for the Feb. 15 issue of ACS�
Environmental Science & Technology, a semi-monthly journal.
In the new study, Nancy Shappell and colleagues
explain that endocrine disruptors, both natural hormones and
hormone-like compounds, have been detected in the surface waters. Many
of these endocrine disruptors have estrogenic activity.
Ethinylestradiol, for instance, is an active ingredient in both the
birth control pill and the newly-introduced �no period pill.� It is a
major source of environmental estrogenic activity.
To address this problem, the researchers tested a
new catalyst called Fe-TAML or Fe-B*. In the presence of hydrogen
peroxide, the catalyst quickly and effectively destroyed various forms
of estrogens typically found in post-treatment wastewater, removing 95
percent of the chemicals - including Ethinylestradiol - in 15 minutes.
Estrogenic activity was also diminished to a similar extent. Further
research will evaluate Fe-B*�s efficacy on actual wastewater, in
addition to more extensive evaluation of byproduct toxicities.
Usefulness in wastewater treatment could be doubly beneficial, as
Fe-B* has been reported to destroy harmful bacterial spores. - MTS
Wiping out the coffee-ring effect advances
inkjet printing of electronic circuits
Examples of printed line
behaviors from inkjet printers: (a) individual drops, (b)
scalloped, (c) uniform, (d) bulging, and (e) stacked coins.
Image: Courtesy of the American
Chemical Society
Researchers in California report a key advance in
efforts to use inkjet printing technology in the manufacture of a new
generation of low cost, high-performance electronic circuits for
flexible video displays and other products. Their study, which
describes development of a new method for producing straighter,
uniform circuits using inkjet-printing, is scheduled for the March 4
issue of ACS� Langmuir, a bi-weekly publication.
In the report, Dan Soltman and Vivek Subramanian
note that inkjet-printed circuits must be extremely smooth and
straight. That difficult feat has been elusive because the
drop-by-drop nature of inkjet-printing often leaves uneven printed
features on surfaces, especially a circular pattern known as the
�coffee ring� effect, they note.
The scientists describe a new way to optimize
printing conditions to eliminate the coffee-ring effect and produce
smooth, narrow lines with an even edge. The development demonstrates
the feasibility of tuning and optimizing inkjet technology for
microelectronic applications, they say. - MTS
Converting sewage into drinking water: Wave of
the future?
Amid growing water shortages in
parts of the United States, more communities are considering tapping
their sewage treatment plants as a new source of drinking water. The
conversion of wastewater into tap water could help meet increased
demand for one of life�s most essential resources, according to an
article scheduled for the Jan. 28 issue of Chemical & Engineering
News, ACS�s weekly newsmagazine.
C&EN Associate Editor Jyllian Kemsley notes in the
article that some communities have used recycled wastewater for
decades to replenish their drinking water supplies and wastewater
often finds agricultural use for irrigation. Droughts, environmental
concerns, and population growth now are forcing water utilities to
consider adapting or expanding the practice, Kemsley explains.
Earlier in January, for instance, California approved operation of the
Advanced Water Purification Facility (AWPF), the largest water
reclamation plant in the nation. It will yield 70 million gallons per
day of drinkable water from sewage. That�s about 10 percent of the
district�s daily water demand for its 2.3 million residents. Although
AWPF�s purification process is complex, it produces clean, pure water
that meets or exceeds all drinking water standards, the article notes.
In early 2007, chemist Karl
Scheidt�s interest was piqued when marine chemist Amy Wright reported
about a new natural compound derived
from an uncommon deep-sea sponge was extremely effective at inhibiting
cancer cell growth.
As a synthetic chemist fascinated by natural products and their
potential in medicine, Scheidt knew what he had to do: Make that
molecule. Macrolide Neopeltolide.
A new chemical synthesis method based on a catalyst
worth many times the price of gold and providing a far more efficient
and economical method than traditional ones for designing and
manufacturing extremely novel pharmaceutical compounds is described by
its University at Buffalo developers in a review article in the
current issue of Nature.
JILA solves problem of quantum dot 'blinking'
Semiconductor nanocrystals have a secret problem: a kind of
nervous tic. They mysteriously tend to �blink� on and off like
Christmas tree lights, which can reduce their usefulness.
Debut of TEAM 0.5 - the World's Best
Microscope
TEAM 0.5 is the world's most powerful transmission electron
microscope and is capable of producing images with half-angstrom
resolution, less than the diameter of a single hydrogen atom.
This colorful image represents a nano-sized
crystalline cage that shows promise as a superior storage material
for methane.
Image by Shengqian Ma, Miami University
In a major advance in alternative fuel technology,
researchers report development of a sponge-like material with the
highest methane storage capacity ever measured. It can hold almost
one-third more methane than the U.S. Department of Energy�s (DOE)
target level for methane-powered cars, they report in a new study. It
is scheduled for the Jan. 23 issue of ACS� Journal of the American
Chemical Society, a weekly publication.
Hong-Cai Zhou and colleagues note that lack of an
effective, economical and safe on-board storage system for methane gas
has been one of the major hurdles preventing methane-driven
automobiles from competing with traditional ones. Recently,
highly-porous, crystalline materials called metal-organic frameworks (MOFs)
have emerged as promising storage materials due to their high surface
areas. However, none of the MOF compounds have reached DOE target
levels considered practical for fuel storage applications, the
scientists say.
The report describes development of a new type of
MOF, called PCN-14, that has a high surface area of over 2000 m2/g.
Laboratory studies show that the compound, composed of clusters of
nano-sized cages, has a methane storage capacity 28 percent higher
than the DOE target, a record high for methane-storage materials, the
researchers say. - MTS
Growing consumer demand for �greener� cleaning
products sparks industry changes
Amid growing consumer demand for more
environmentally-friendly cleaning products, chemical suppliers are
stepping-up their efforts to provide greener ingredients with the same
effectiveness of conventional ones, according to an article scheduled
for the Jan. 21 issue of Chemical & Engineering News, ACS� weekly
newsmagazine.
In the magazine�s cover story, C&EN Assistant
Managing Editor Michael McCoy notes that �green� cleaning supplies
were once the province of fringe industries but are now attracting the
attention of big corporations in the United States and beyond.
Increasingly, suppliers are generating consumer cleaning products that
contain natural or naturally-derived ingredients, avoid the use of
environmentally-harmful chemicals, and generate less carbon dioxide
during manufacturing and use, McCoy states. Consumer products giant
Clorox will join the bandwagon this month by rolling out a new line of
green cleaning products with the earth-friendly name Green Works, he
notes.
Under pressure from groups including consumers, the
government and the news media, chemical suppliers are feverishly
working to come up with new ingredients that are both
environmentally-friendly and perform as well as conventional cleaning
products, the writer notes. But the road to green is not necessarily a
smooth one. For one thing, there is no consensus on what is considered
natural. Moreover, environmental standards can vary from region to
region, the article points out. Still, there are clear signs that
greener cleaning supplies will become more commonplace and more
competitive with conventional ones, a trend that could make for a
cleaner, greener future, the article suggests.
New microchip for PCR testing at crime scenes,
doctors� offices
This tiny microchip (center, attached to pipette
tips) could give researchers the ability to analyze DNA at crime
scenes, doctor's offices and other out-of-lab locations.
Image by I-Ming Hsing, the Hong Kong University of
Science and Technology
Researchers in Hong Kong have miniaturized
technology needed to perform the versatile polymerase chain reaction
(PCR) - widely used in criminal investigations, disease diagnosis, and
a range of other key applications. In a study scheduled for the Jan.
15 issue of ACS� Analytical Chemistry, a semi-monthly journal, they
report development of a long-sought PCR microchip that could permit
use of PCR at crime scenes, in doctors� offices, and other out-of-lab
locations.
I-Ming Hsing and colleagues note that PCR works
like a biological copy machine, transforming a few wisps of DNA into
billions of copies. However, existing PCR machines are so big and
complex that they can be used only in laboratories. Scientists have
searched for years for a portable, PCR technique that can be used
outside the lab.
The study describes a new PCR technique that uses
electrochemical DNA sensors to provide simultaneous DNA amplification
and detection on a silicon-glass microchip. Their performance tests
show that the new technique, called electrochemical real-time PCR
(ERT-PCR), is about as fast and sensitive as conventional PCR. The new
technique shows �tremendous� promise as a portable system for moving
DNA analysis out of the lab and into remote locations, the researchers
say. - MTS
Celecoxib can adversely affect heart
rhythm
COX-2 inhibitors like Celecoxib have come under scrutiny lately
due to adverse cardiovascular side-effects stemming from COX-2
reduction. In both fruit fly and rat models, researchers reveal
another adverse effect of Celecoxib; this drug can induce
arrhythmia. More interestingly, this effect is independent of
the COX-2 enzyme.
New buffer resists pH change, even as
temperature drops
Researchers have found a simple solution to a problem that has
plagued scientists for decades: the tendency of chemical buffers
used to maintain the pH of laboratory samples to lose their
efficacy as the samples are cooled.
Seagull blood shows promise for monitoring
pollutants from oil spills
Seagull blood shows promise for
monitoring pollutants from oil spills in marine environments.
Image by Alberto Velando,
Universidade de Vigo, Spain
Like the proverbial coal miners� canary-in-the-cage,
seagulls may become living sentinels to monitor oil pollution levels
in marine environments, report scientists in Spain. Their study is
scheduled for the Feb. 1 issue of ACS� Environmental Science &
Technology, a semi-monthly journal.
In the study, Alberto Velando and colleagues note
that researchers have known for years that large oil spills can
increase levels of polycyclic aromatic hydrocarbons (PAHs) in marine
environments. Studies have linked these compounds to cancer in humans.
While oil spills quickly kill large numbers of seabirds and other
animals, scientists do not fully understand the non-lethal biological
effects of these spills, the Spanish researchers say.
The researchers measured PAH levels in the blood of
Yellow-legged gulls living in the vicinity of the oil spill caused by
the 2002 shipwreck of the Prestige, one of Europe�s largest oil spills.
Gulls exposed to the oil showed twice the levels of PAHs in their
blood than unexposed birds, even though these levels were measured 17
months after the initial spill, the researchers say. The findings
�give support to the nondestructive use of seabirds as biomonitors of
oil pollution in marine environments,� the article states. - MTS
Scientists in the United States and India are
reporting development of a high-protein variety of rice, dietary
staple for half the world�s population. The study is scheduled for the
Jan. 23 issue of ACS� Journal of Agricultural and Food Chemistry, a
biweekly publication.
Researchers have been trying to bolster the protein
in rice for five decades. Rice already is a main source of calories as
well as protein intake for billions of people, and its enrichment of
protein would have a positive impact on millions of poor and
malnourished people in developing countries, the report says.
In the study, Hari B. Krishnan and colleagues
created a hybrid by crossing a commonly cultivated rice species called
Oryza sativa with a wild species, Oryza nivara. The product showed a
protein content of 12.4 percent, which is 18 percent and 28 percent
higher than those of the parents. The results demonstrate the
potential for wild rice�s relatives for boosting the protein content
in rice. The researchers conclude that the hybrid could serve as
initial breeding material for new rice genotypes that could combine
types with superior cooking quality with those of high protein content.
- JS
Edible �antifreeze� prevents unwanted ice
crystals in ice cream and frozen foods
Researchers have developed an
edible "antifreeze" that shows promise for preventing the
formation of ice crystals in ice cream.
Foto by USDA-ARS, Keith Weller
A scientist in Wisconsin reports development of an
edible and tasteless �antifreeze� that prevents the formation of ice
crystals that can spoil the smooth, silky texture of ice cream and
interfere with the palatability of other frozen foods. The study is
scheduled for the Jan. 9 issue of ACS� Journal of Agricultural and
Food Chemistry, a bi-weekly publication.
In the new report, Srinivasan Damodaran explains
that preventing the formation of large ice crystals is a major
challenge for frozen food manufacturers and consumers who store
packages in home freezers. Although several different substances have
been added to frozen foods to prevent ice crystal growth, none is
really effective, the researcher says.
Damodaran�s solution is gelatin hydrolysate, a
protein known to act as a natural antifreeze. In a controlled study
using batches of ice cream prepared with and without the non-toxic
compound, ice cream containing the antifreeze developed significantly
smaller and fewer ice crystals than batches prepared without the
compound, the researcher says. - MTS
Once-irrelevant compound may have medical role
in preventing diabetes complications
A compound formed during insulin production and
once dismissed as irrelevant in diabetes may be a key to preventing
the complications that make Type 1 diabetes such a serious disease,
according to an article [http://pubs.acs.org/cen/science/86/8602sci1.html]
scheduled for the Jan. 14 issue of Chemical & Engineering News, ACS�
weekly newsmagazine. Type 1 diabetes, also known as insulin-dependent
diabetes, afflicts about 800,000 people in the U.S. alone, sharply
increasing their risk of heart attacks, vision loss, kidney failure,
and other complications.
In the article, C&EN Senior Editor Celia Henry
Arnaud notes that scientists previously believed that the compound,
called C-peptide, had little biological activity and was a useless
byproduct of insulin production. In recent years, however, researchers
have seen beneficial effects of C-peptide in patients with type 1
diabetes, including improved kidney function, nerve function, and
blood flow. New laboratory research now bolsters that view, suggesting
that the compound may work by enhancing the ability of red blood cells
to utilize glucose similar to the role that insulin plays for other
cell types but only when it binds a metal ion, the article notes.
Clinical studies on the compound, so far
inconclusive, may determine if C-peptide can help prevent or delay
complications of type 1 diabetes, Arnaud points out. The new research
is �a significant contribution to our understanding of C-peptide
biology,� according to the article.
The bright, metallic sheen
of fish skin is due to a sophisticated system of crystals, Israeli
scientists report.
Courtesy of Florida Keys NMS;
Photo by Bob Care
The bright, metallic sheen of fish skin - source of
endless fascination for fishermen and aquarium owners - is due to a
sophisticated system of crystals that enhance light reflection and may
help fish hide from predators in the wild, scientists in Israel are
reporting. Their study is scheduled for the current issue of ACS�
Crystal Growth & Design, a bi-monthly journal.
In the new study, Lia Addadi and colleagues note
that researchers have known for years that guanine crystals in the
skin underneath the scales of fish reflect light to produce a
mirror-like sheen. This silvery reflectance acts as a form of
camouflage that helps protect fish from predators as fish swim near
the water�s surface. However, the exact shape of these guanine
crystals and how they work remained a mystery.
The researchers extracted guanine crystals from the
skin of the Japanese Koi fish and analyzed the crystals using X-ray
diffraction and an electron microscope. They compared the results to
guanine crystals made in the laboratory. The researchers found that
the biogenic crystals develop in an unexpected direction that differs
from the lab-made crystals and that their unique shape improves light
reflectivity. The arrangement represents a �strategy evolved by fish
to produce more efficient photonic crystals,� the article states. -
MTS
Scientists at Arizona State University�s Biodesign
Institute have developed the world�s first gene detection platform
made up entirely from self-assembled DNA nanostructures. The results,
appearing in the January 11 issue of the journal Science, could have
broad implications for gene chip technology and may also revolutionize
the way in which gene expression is analyzed in a single cell.
Silver-rich Lumps
Large cluster complexes with almost 500 silver atoms.
Electrospray droplet research yields
surprising, practical results
Chemical engineers are the first to mathematically describe
precisely how droplets form when liquids are exposed to electric
fields, an advance that could have applications in areas ranging
from manufacturing to medical diagnostics.
Researchers bend light through waveguides
in colloidal crystals
Researchers at the University of Illinois are the first to
achieve optical waveguiding of near-infrared light through
features embedded in self-assembled, three-dimensional photonic
crystals.
A �fingerprint� for fruit juices
Adulterations or other possible food frauds are a financial
problem that affects many foodstuffs. This is why achieving the
authentification of food products is of great importance. In the
case of fruit juices the most common type of adulteration is
mixing the original juice with juices from other, cheaper fruits
(mainly grapefruit, grape or pear); in other words falsifying
the juice...
ACS News:
Amber fossils reveal ancient France was a jungle
Amber fossils collected in France
suggest that the country was once a jungle.
Courtesy of Andr� Nel, Mus�um
National d�Histoire Naturelle, Paris
Research on a treasure trove of amber has yielded
evidence that France once was covered by a dense tropical rainforest
with trees similar to those found in the modern-day Amazon. The report
on 55-million-year-old pieces of amber from the Oise River area in
northern France is scheduled for the Jan. 4 issue of ACS� Journal of
Organic Chemistry, a biweekly publication.
In the new study, Akino Jossang and colleagues used
laboratory instruments to analyze the fossilized tree sap in an effort
to link specific samples of amber to specific kinds of trees. The
amber remained intact over the ages, while the trees from which it
oozed disappeared. Efforts to make such connections have been
difficult because amber from different sites tended to have very
similar chemical compositions. The report describes discovery of a new
organic compound in amber called �quesnoin,� whose precursor exists
only in sap produced by a tree currently growing only in Brazil�s
Amazon rainforest.
Researchers say that amber probably seeped out of a
similar tree growing in a tropical forest that covered France millions
of years ago before Earth�s continents drifted into their current
positions. �The region corresponding to modern France could have been
found in a geographically critical marshy zone belonging to Africa and
a tropical zone 55 million years ago extending through North Africa to
the Amazon,� the report states. - AD
Toward solving the mystery of idiosyncratic drug
reactions
A mysterious and unpredictable group of side
effects from modern medications called idiosyncratic drug reactions (IDRs)
likely will persist as a major health care problem unless there is a
dramatic increase in research funding, according to a 20-year review
of research in the field scheduled for the January issue of ACS�
Chemical Research in Toxicology, a monthly journal.
The review, by Jack Uetrecht, defines IDRs as
reactions that happen unexpectedly and with no obvious connection to
the known effects of a medication�s ingredients or dosage. Although
relatively rare, IDRs make an important contribution to the annual
burden of death, illness, and increased health care costs from serious
adverse drug reactions. In addition, serious IDRs that appear after a
new drug has gone into wide use can force drug companies to withdraw
products after R&D investments totaling hundreds of millions of
dollars.
Two decades of research have produced significant
progress, the report acknowledges. However, medical science still has
only a �superficial� understanding of how and why IDRs occur and a
growing recognition that the mechanisms behind IDRs may be as
complicated as those involved in cancer or diabetes. The review
describes a need for increased research funding, with more scientists
focusing on IDRs, in order to achieve faster progress. - JS
Toward preventing the warping and splitting of wood
Scientists in France and Japan report an advance
toward unlocking the secrets of �tension wood (TW),� a step that could
have practical applications in preventing costly warping and splitting
of wood used in construction projects. The report is scheduled for the
Jan. 14 issue of ACS� Biomacromolecules, a bi-monthly journal.
In the study, Bruno Clair and colleagues point out
that whereas normal wood tends to shrink a small amount when dried, TW
undergoes surprisingly high shrinkage. This shrinkage makes it
undesirable for use in sun decks and other construction applications.
Now, researchers want a valid explanation for this phenomenon.
In the current study, Clair and colleagues
collected TW and normal wood samples from a chestnut tree and exposed
the samples to different drying conditions. Using nitrogen adsorption,
a technique to measure the porosity of materials, they found that the
TW was composed of a gel-like layer with a surface area more than 30
times higher than in normal wood. The collapse of this gel during
drying likely caused TW�s high shrinkage rate, the scientists say. The
finding could lead to ways to reduce this shrinkage in order to make
TW more usable for construction applications. - MTS
Discovery of enzyme�s structure may lead to new
treatments for celiac disease
Researchers have discovered a new structure for a
key enzyme associated with celiac disease, a finding that could lead
to the design of new medications for the common digestive disorder,
according to an article scheduled for the Jan. 7 issue of Chemical &
Engineering News, ACS� weekly newsmagazine.
Celiac disease is a condition in which the stomach
cannot properly digest wheat and other gluten-containing foods. The
disease afflicts an estimated 2 million people in the United States
alone.
In the article, C&EN Deputy Assistant Managing
Editor Stu Borman notes that the disease is believed to occur when the
protein gluten interacts with an enzyme called transglutaminase 2
(TG2), triggering an autoimmune reaction that damages the small
intestine and causes diarrhea, abdominal pain and other symptoms. As a
result, people with the disease are urged to follow a strict
gluten-free diet.
Although scientists have previously obtained the
X-ray crystal structure of human TG2, they have only revealed its
�closed� or inactive form, the article points out. Now, Chaitan Khosla
and colleagues at Stanford University report the first-ever
determination of the �open� structure of the enzyme, in which its
active site is accessible to substrates. The finding that could help
scientists design inhibitors of the enzyme that could serve as
medications for celiac disease and other related conditions, according
to the article.
Research explores role of hydrogen
peroxide in cell health
Hydrogen peroxide, the same mild acid that many people use to
disinfectant their kitchens or treat cuts and abrasions, is also
produced by the body to keep cells healthy ...
Smaller is Stronger - Now Scientists Know Why!
As metal structures get smaller - as their dimensions approach
the micrometer scale or less - they get stronger. Now scientists
have learned how.
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