Research scientists at the Ruhr-University in Bochum were able to show that hydrogen atoms always result in n-doping. They could reversibly dope zinc oxide substrates using hydrogen and then eliminate the hydrogen by heating.
Powerful antioxidant properties to fight diseases, efficient catalyst for converting biofuels.
Fast molecular rearrangements hold key to plastic's toughness
Plastics are everywhere in our modern world, largely due to properties that render the materials tough and durable, but lightweight and easily workable. One of their most useful qualities, however - the ability to bend rather than break when put under stress - is also one of the most puzzling.
E. coli engineered to produce important class of antibiotic, anti-cancer drugs
Researchers have taken a major step forward in the field of metabolic engineering, successfully using the bacterium Escherichia coli to synthesize a class of natural products known bacterial aromatic polyketides, which include important antibiotic and anticancer drugs.
Early Interrogation and Recognition of DNA Sequence by Indirect Readout.
Image:
Crystals of the DNA-snipping protein HincII taken under a microscope. The crystals are iridescent because they refract light. The longest crystal is about one millimeter.
[Image credit: Nancy C. Horton, the University of Arizona]
Brown University chemist David Cane and international colleagues have identified the genetic sequence behind gray mold's killer arsenal. In an ACS Chemical Biology paper, the scientists report that deletion of a single, mastermind gene from gray mold's DNA shuts down its ability to produce toxins that kill cells in more than 200 species of garden and ornamental plants.
Sulfurous ping-pong in the urinary tract
Researchers studying transfer processes among sulfurylated molecules discovered a protein, sulfotransferase, whose function is known but which exhibits a previously unknown structure.
Study on cytotoxicity of carbon nanotubes
Owing to the novel properties of carbon nanotubes, a series of problems associated with in vitro toxicity assessments of carbon nanotubes have appeared in a lot of literature. In order to properly evaluate the potential risk to human health, the cell toxicity assay of carbon nanotubes can not be conducted by traditional methods employed in common toxicology.
Researchers coax bright white light from unexpected source
Duke University and United States Army scientists have found that a cheap and nontoxic sunburn and diaper rash preventative can be made to produce brilliant light best suited to the human eye.
Research could pave way for new data storage devices, drug delivery systems.
Photo:
A scanning electron micrograph of cobalt nanoclusters embedded in multi-walled carbon nanotubes. Researchers at Rensselaer used these new hybrid structures, the first of their kind, to detect magnetism at the nanoscale.
Sweet molecule could lead us to alien life
Scientists have detected an organic sugar molecule that is directly linked to the origin of life, in a region of our galaxy where habitable planets could exist.
Scientists have identified
chemical structures in pollen - shown above covering the face and
legs of a Marmelade fly- that could help provide a real-time
pollen detection and warning system to help allergy sufferers.
Image by Andr� Karwath
Researchers in Germany are reporting an advance
toward development of technology that could make life easier for
millions of people allergic to plant pollen. It could underpin the
first automated, real-time systems for identifying specific kinds of
allergy-inducing plant pollen circulating in the air. Their study is
in the current issue of ACS' Analytical Chemistry, a semi-monthly
journal.
In the study, Janina Kneipp and colleagues explain
that current pollen counts and allergy warnings are based on visual
identification of the specific kind of pollen by examining pollen
grains under a microscope. That procedure takes time, making it
impossible for allergy-sufferers to know the kinds of pollen that are
airborne on an hour-by-hour basis.
The researchers describe using a common laboratory
procedure to identify chemical structures in pollen grains that
distinguish oak and maple pollen, for instance, from maple and other
kinds. They obtained these chemical "signatures" for 15 different
kinds of tree pollen with the procedure, termed Raman spectroscopy.
The researchers say that it could provide the basis for a real-time
pollen detection and warning system to help allergy sufferers. - MTS
Waste coffee grounds offer new source of
biodiesel fuel
Researchers in Nevada are reporting that waste
coffee grounds can provide a cheap, abundant, and environmentally
friendly source of biodiesel fuel for powering cars and trucks. Their
study appears in the current online issue of ACS' Journal of
Agricultural and Food Chemistry, a bi-weekly publication.
In the new study, Mano Misra, Susanta Mohapatra,
and Narasimharao Kondamudi note that the major barrier to wider use of
biodiesel fuel is lack of a low-cost, high quality source, or
feedstock, for producing that new energy source. Spent coffee grounds
contain between 11 and 20 percent oil by weight. That's about as much
as traditional biodiesel feedstocks such as rapeseed, palm, and
soybean oil.
Growers produce more than 16 billion pounds of
coffee around the world each year. The used or "spent" grounds
remaining from production of espresso, cappuccino, and plain
old-fashioned cups of java, often wind up in the trash or find use as
soil conditioner. The scientists estimated, however, that spent coffee
grounds can potentially add 340 million gallons of biodiesel to the
world's fuel supply.
To verify it, the scientists collected spent coffee
grounds from a multinational coffeehouse chain and separated the oil.
They then used an inexpensive process to convert 100 percent of the
oil into biodiesel.
The resulting coffee-based fuel - which actually
smells like java - had a major advantage in being more stable than
traditional biodiesel due to coffee's high antioxidant content, the
researchers say. Solids left over from the conversion can be converted
to ethanol or used as compost, the report notes. The scientists
estimate that the process could make a profit of more than $8 million
a year in the U.S. alone. They plan to develop a small pilot plant to
produce and test the experimental fuel within the next six to eight
months. - MTS
Better antifreezes to preserve donor organs for
transplantation
Chemists have developed a method
to better preserve organs for transplantation.
Image by The American Chemical
Society
Chemists in Canada have developed a new approach
for producing more effective medical antifreeze fluids for preserving
kidneys, hearts, and other organs donated for transplantation. These
next-generation antifreezes can decrease damage to organs caused by
ice crystals, and thus prolong the time a donated organ will remain
viable prior to transplantation. This could increase the number of
available organs for potential recipients. Their study is scheduled
for the current issue of the Journal of the American Chemical Society,
a weekly publication.
Robert N. Ben and colleagues note that the growth
of ice crystals is a major cause of damage to cells, tissues and
organs during cryopreservation, which leaves them unusable for
transplantation. To address this challenge, the researchers developed
synthetic antifreeze materials, called C-linked antifreeze
glycoprotein analogues (C-AFGP). These proteins contain a sugar
coating and have custom-tailored antifreeze activity.
Now the scientists describe the development of "hydration
index" that can be used to more reliably predict how prospective
antifreeze materials will behave. Their index provides a clearer
picture of how water molecules interact with the sugar component (as
well as native AFGP) and affect their chemical behavior. This is a key
to understanding their ability to resist the formation of ice crystals
when chilled. - MTS
Producing a more effective oral form of a
powerful disease-fighting protein
Scientists in Japan are reporting an advance toward
using a natural disease-fighting protein in pills or syrups that
patients can take by mouth rather than injection. Their study is the
first to show that coating the protein with a polymer material already
in wide medical use can increase its absorption by the intestine. The
research appears in the current issue of ACS' Bioconjugate Chemistry,
a monthly journal.
In the study, Atsushi Sato and colleagues note that
the protein - lactoferrin (LF) - occurs in saliva, breast milk and
other body fluids, where it has powerful effects in fighting bacteria,
viruses, and inflammation. LF is sparking excitement as a potential
treatment for cancer, gangrene, hepatitis, and a host of other
diseases. Although LF is available as a dietary supplement and as an
experimental oral drug, acid in the stomach quickly destroys existing
forms of LF, reducing the protein's effects.
The scientists found that laboratory rats absorbed
10 times more LF if the protein is coated with the polymer, called
polyethylene glycol (PEG). In addition, the coated PEG remained active
in the bloodstream longer than the uncoated protein. The scientists
also showed that the coated drug retained most of its disease-fighting
potency, including antibacterial, antioxidative and anti-inflammatory
activity, compared to the uncoated drug. The PEG-coating technique not
only is a promising advance toward making lactoferrin an oral drug,
but also may be used to convert other healthful food proteins into
useful drugs, the researchers note. - MTS
The trees of Christmas future may be safer from an
insect pest that makes Ebenezer Scrooge's famous nightmare pale in
comparison - killing millions of pine trees, according to an scheduled
for the December 22 issue of Chemical & Engineering News, ACS' weekly
newsmagazine. That tiny beetle, which is decimating the certain
populations of pine trees, has led chemists to develop new, more
effective control methods that could help save these economically and
environmentally important trees, it added.
In the article, C&EN Associate Editor Rachel
Petkewich points out that the mountain pine beetle has killed millions
of acres of pine trees. About the size of a grain of rice, the beetles
damage trees by boring into bark and depositing their eggs. Dead trees
also pose a forest fire risk, the article notes.
Scientists now are fighting back with a combination
of chemistry and forestry management techniques. The management
techniques involve removing infected trees, diversifying tree species,
monitoring beetle populations, and thinning forests in advance of an
outbreak. Researchers are also experimenting with chemical protection
and control methods using bug-repelling plant hormones and
insecticides, according to the article.
High pesticide levels found in fruit-based
drinks in some countries outside U. S.
Elevated levels of pesticides
appear in fruit-based soft drinks in many countries, scientists
report.
Image by Wikipedia Commons
In the first worldwide study of pesticides in
fruit-based soft drinks, researchers in Spain are reporting relatively
high levels of pesticides in drinks in some countries, especially the
United Kingdom and Spain. Drinks sampled from the United States,
however, had relatively low levels, the researchers note. Their study
is scheduled for the December 15 issue of ACS' Analytical Chemistry, a
semi-monthly journal.
In the report, Antonio Molina-D�az, Amadeo
Fern�ndez-Alba and colleagues note that strict regulations limit
pesticide levels in fresh fruits, vegetables, and drinking water.
However, regulators have paid less attention to the presence of
pesticides in soft drinks made from fruits. Scientists are
increasingly concerned about the possible impact of
pesticide-containing fruit juices on the health of children, who tend
to consume large amounts of such soft drinks, they add.
The scientists used a sophisticated lab test to
measure levels of a wide range of common pesticides in more than 100
fruit-based soft drink samples from 15 different countries. They
tested for pesticides such as carbendazim, thiabendazole, and imazalil,
and malathion, which are applied to crops after harvest and can remain
on fruits and vegetables during processing. They found relatively
large concentrations of pesticides, in the micrograms per liter range,
in most of the samples analyzed. Samples from Spain and the U. K. had
the highest levels of pesticides, while samples from the U. S. and
Russia were among the lowest. "Steps should be taken toward the
removal of pesticides in these beverages by changing the way they are
manufactured," the researchers conclude. - MTS
Scientists have identified the
cluster of genes responsible for "gray mold," a common,
devestating plant disease.
Credit: American Chemical Society
Scientists are reporting identification of the
cluster of genes responsible for the toxins produced by "gray mold," a
devastating plant disease that kills almost 200 different food and
ornamental plants including tomatoes, strawberries and roses. Their
findings could lead to genetically engineered crops or new fungicides
to fight this disease, which frustrates backyard gardeners and
commercial farmers alike, the researchers say. The study is in the
current online issue issue of ACS Chemical Biology, a monthly journal.
David Cane, Isidro Collado, Muriel Viaud and
colleagues note that gray mold is so-named because it covers infected
plants with fuzzy gray spores that can ultimately kill plants. A
fungus named Botrytis cinerea causes the disease. Studies show that
the fungus kills by producing two main plant toxins, botrydial and
botcinic acid. Conventional fungicides are largely ineffective in
destroying the fungus, which can easily spread to other plants.
In the new study, the scientists describe the
identification of five genes involved in producing the enzymes that
are responsible for making the toxins produced by the fungus. In lab
studies, the researchers showed that inactivating one of the genes,
called BcBOT2, blocked the gene cluster's ability to make the
botrydial toxin. The finding could help the development of new, more
effective fungicides or other resistance strategies, that target the
ability of B. cinerea to make botrydial, the researchers suggest. -
MTS
Tiny delivery system with a big impact on cancer
cells
A new group of nanocomposite
particles could lead to improved anti-cancer drugs, researchers
report.
Credit: Hari S. Muddana
Researchers in Pennsylvania are reporting for the
first time that nanoparticles 1/5,000 the diameter of a human hair
encapsulating an experimental anticancer agent, kill human melanoma
and drug-resistant breast cancer cells growing in laboratory cultures.
The discovery could lead to the development of a new generation of
anti-cancer drugs that are safer and more effective than conventional
chemotherapy agents, the scientists suggest. The research is scheduled
for the Dec. 10 issue of ACS' Nano Letters, a monthly journal.
In the new study, Mark Kester, James Adair and
colleagues at Penn State's Hershey Medical Center and University Park
campus point out that certain nanoparticles have shown promise as drug
delivery vehicles. However, many of these particles will not dissolve
in body fluids and are toxic to cells, making them unsuitable for drug
delivery in humans. Although promising as an anti-cancer agent,
ceramide also is insoluble in the blood stream making delivery to
cancer cells difficult.
The scientists report a potential solution with
development of calcium phosphate nanocomposite particles (CPNPs). The
particles are soluble and with ceramide encapsulated with the calcium
phosphate, effectively make ceramide soluble. With ceramide
encapsulated inside, the CPNPs killed 95 percent of human melanoma
cells and was "highly effective" against human breast cancer cells
that are normally resistant to anticancer drugs, the researchers say.
Penn State Research Foundation has licensed the
calcium phosphate nanocomposite particle technology known as "NanoJackets"
to Keystone Nano, Inc. MK and JA are CMO and CSO, respectively. - MTS
Tracking community-wide drug use by testing
water at sewage treatment plants
Scientists in Oregon and Washington State are
reporting the development and successful testing of a new method for
determining the extent of illicit drug use in entire communities from
water flushed down toilets that enters municipal wastewater treatment
plants. The technique may be an effective tool for comparing drug use
in different regions of the United States and the world, they note in
a study is scheduled for the December 15 issue of ACS' Environmental
Science & Technology, a semi-monthly journal.
In the study, Aurea C. Chiaia and colleagues note
that the new test eliminates the need for sample preparation - saving
time and money and decreasing the risk of sample contamination. They
proved the test's effectiveness by measured levels of illegal drugs
like methamphetamine and legal drugs like prescription painkillers in
wastewater from seven U.S. municipalities. The research team also
tested the levels of 'urine indicators' such as creatinine, a
metabolic byproduct that can be used as an indicator of drug use.
The scientists determined the 'index loads' of the
different drugs - the amount of drug per person per day - based on
estimates of the population served by each wastewater facility. These
calculated index loads generally reflect known illegal drug use
patterns in the US and worldwide. The loads for methamphetamine in
western and southern U.S. were much larger than previous reports from
Europe, for example. The authors proposed that urine indicator
compounds like creatinine could be used in place of population
estimates - which can fluctuate and be unreliable - to determine more
accurate community-level drug index loads, which can then be compared
between municipalities. - KSD
Healthy make-over: Natural colors replace
artificial colorants in foods, beverages
In the future, Santa may be leaving candy canes and
nibbling holiday cookies that are a little duller, but better for your
health. The reason? Food color manufacturers are going natural. Food
manufacturers worldwide are increasingly turning to more natural
colors in an effort to replace potentially harmful, though often
dazzling, artificial colorings now used in many foods and beverages.
An article on this topic is scheduled for the December 15 issue of
Chemical & Engineering News, ACS' weekly newsmagazine.
In the article, C&EN senior editor Melody Voith
points out that some artificial colors, such as Red #40, have been
linked to hyperactivity in children as well as other health problems.
Such health concerns have spurred colorant phase-outs and new
regulations, causing manufacturers to search for natural alternatives.
Food coloring now represents a $1.2 billion global market, with
natural colors capturing 31 percent of the food market but growing at
a rate of 5 percent yearly, according to the article.
The switch is not easy. Food manufacturers are
finding it difficult to substitute synthetic colors with natural ones
that preserve the exact look and appeal of the original product, whose
quality consumers often judge by appearance. That's why researchers
are now experimenting with a wide range of natural colorants derived
from dark-colored vegetables in an effort to closely match their
artificial counterparts. Ingredient makers are looking, for example,
to red cabbage and purple sweet potatoes to provide new natural
sources of red, purple, and blue, the article notes.
Advance toward early diagnosis of chronic
obstructive pulmonary disease
Researchers have identified a "biomarker"
that could lead to early detection of chronic obstructive
pulmonary disease.
Credit: National Heart Lung and
Blood Institute
Researchers in Finland are reporting identification
of the first potential "biomarker" that could be used in development
of a sputum test for early detection of chronic obstructive pulmonary
disease (COPD). That condition, which causes severe difficulty in
breathing - most often in cigarette smokers - affects 12 million
people in the United States.
In an article scheduled for the December 5 issue of
ACS' Journal of Proteome Research, a monthly publication, Vuokko L.
Kinnula and colleagues point out that no disease marker for COPD
currently exists, despite extensive efforts by scientists to find one.
Past research pointed to a prime candidate - surfactant protein A
(SP-A), which has a major role in fighting infections and inflammation
in the lung.
The scientists compared levels of a variety of
proteins obtained from the lung tissues of healthy individuals,
patients with COPD, and those with pulmonary fibrosis. They found that
the lungs of COPD patients contained elevated levels of SP-A. The
scientists also found elevated levels of SP-A in the sputum samples of
COPD patients. "This suggests that SP-A might represent a helpful
biomarker in the early detection of COPD and other related disorders,"
the article notes. - MTS
Clothing with a brain: "Smart fabrics" that
monitor health
Researchers have developed a
cost-effective procedure of making disease-detecting wearable
fabrics, "smart fabrics." Above are microscopic images of the
E-fibers.
Credit: American Chemical Society
Researchers in United States and China are
reporting progress toward a simple, low-cost method to make "smart
fabrics," electronic textiles capable of detecting diseases,
monitoring heart rates, and other vital signs. A report on these
straight-out-of-science-fiction-fibers, made of carbon nanotubes, is
scheduled for the December 10 issue of ACS' Nano Letters, a monthly
publication.
In the new study, Nicholas A. Kotov, Chuanlai Xu,
and colleagues point out that electronic textiles, or E-textiles,
already are a reality. However, the current materials are too bulky,
rigid, and complex for practical use. Fabric makers need simpler, more
flexible materials to make E-fibers practical for future applications,
they say.
The scientists describe development of cotton
fibers coated with electrolytes and carbon nanotubes (CNT) - thin
filaments 1/50,000 the width of a single human hair. The fibers are
soft, flexible, and capable of transmitting electricity when woven
into fabrics. In laboratory tests, the researchers showed that the new
E-fibers could light up a simple light-emitting diode when connected
to a battery. When coated with certain antibodies, the fibers detected
the presence of albumin, a key protein in blood - a function that
could be used to detect bleeding in wounded soldiers. The fabrics
could also help monitor diseases and vital signs, they say. - MTS
Waste peel from pomegranate juice factories
makes healthy cattle feed
Feed supplemented with
pomegranate peels could usher in healthier, antioxidant-rich meat,
scientists report.
Credit: Zalman Henkin
Pomegranate peel left over from production of the
juice renowned for its potential health benefits can make a nutritious
feed supplement for cattle, researchers in Israel report in an article
in the November 12 issue of ACS' biweekly Journal of Agricultural and
Food Chemistry. The peel packs some of the weight-boosting and
health-enhancing effects of antibiotics and hormones without the
detrimental effects, and researchers say it may yield meat with higher
levels of beneficial antioxidants.
In the new study, Ariel Shabtay and colleagues note
that consumption of pomegranate products is increasing amid reports
that the fruit may help fight cancer, infections, and other diseases
in humans due to its high levels of antioxidants. Recent studies also
have shown that boosting antioxidant levels in the diet of cattle may
help improve their health. Those findings seemed to make pomegranate
peel, a waste product of the pomegranate industry with higher
antioxidant levels than the juice itself, an attractive candidate as a
nutritional supplement for cattle feed.
To find out, the scientists fed calves either
normal cattle feed or feed supplemented with pomegranate peels. After
eight weeks, the calves supplemented with pomegranate had higher blood
levels of alpha-tocopherol, a form of vitamin E that may help retain
nutrients and extend the shelf life of meat by preventing spoilage.
The pomegranate-fed animals gained more weight than the animals on
standard feed. - MTS
New "wipes" for better decontamination of
chemical warfare agents and toxic chemicals
Scientists in Texas, California, and Maryland are
reporting development of high-tech "wipes" that are capable of quickly
decontaminating people and equipment exposed to a broad range of
military and industrial chemicals, including the deadly blister agent
known as "mustard." The next generation wipes, which are a major step
toward a universal personal decontamination system for nearly any
toxic or hazardous chemical, could help save the lives of soldiers and
civilians. Their work will be described in an article scheduled for
online publication today in ACS' Industrial & Engineering Chemistry
Research, a bi-weekly journal.
Seshadri Ramkumar and colleagues note that the
military long has used powders and liquids to decontaminate soldiers
and equipment exposed to chemical warfare agents. But powders, such as
activated carbon, can disperse into the air and damage the lungs,
while water-based and reactive decontamination liquids target only a
limited set of chemicals or can damage electronic equipment. Better
materials are needed, the scientists say.
In the new study, the scientists describe
development of a new fabric-based "wipe" composed of a layer of
activated carbon sandwiched between layers of absorbent fibers. The
researchers evaluated the ability of the new fabric to absorb and
adsorb sulfur mustard, a toxic liquid that causes skin blistering, and
compared the results to activated carbon particles and a standard
military decontamination kit that uses powdered carbon mixed with
other materials. The wipes were better than particulate carbon alone
and as effective as the military decontamination kit, the researchers
say, noting that the flexible and non-particulate wipes show promise
for decontaminating a wide range of surfaces and toxic or hazardous
chemicals. - MTS
Updated standards to reduce metal contaminants
in prescription drugs
Prescription medicines in the United States could
soon have lower levels of potentially harmful metals, as the
organization that sets drug standards develops new limits for
impurities like mercury, arsenic, and lead, according to an article
scheduled for the December 8 issue of Chemical & Engineering News, ACS'
weekly newsmagazine.
In the article, C&EN Associate Editor Jyllian
Kemsley notes that researchers have known for years that potentially
toxic metals can wind up in pharmaceutical ingredients through raw
materials, catalysts, equipment, and other sources. But the testing
method currently prescribed by the U.S. Pharmacopeia (USP), the
nonprofit organization that sets standards for the pharmaceutical
industry, has not kept pace with that new knowledge. That method
involves a 100-year-old test that is time-consuming, difficult to
interpret, and generally not quantitative, according to the article.
USP now is developing new standards and testing
methods that will be finished in 2010 and implemented over a span of
years. USP will require drug makers to use improved methods and
instruments to detect metal contaminants.
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