Carbonized titanium dioxide nanotubes with semimetallic properties increase the efficiency of methanol fuel cells.
A carbo-thermal reduction treatment of a TiO2 nanotube
layer in acetylene converts the tube walls into highly
conductive and stable oxy carbide compounds.
Superheavy Element 114 Confirmed: A Stepping Stone to the Island of Stability.
Image: For decades nuclear scientists have searched for an Island of Stability among notoriously short-lived artificial elements
...
Physicists create first atomic-scale map of quantum dots
University of Michigan physicists have created the first atomic-scale maps of quantum dots, a major step toward the goal of producing "designer dots" that can be tailored for specific applications.
Planetary Chemistry
University of Hawai'i at Manoa team unravels the chemistry of Titan's hazy atmosphere.
|
Chemistry & Materials
Catalytic Catamarans
Common industrial catalyst sports rafts made of platinum. Best view yet of catalyst used for energy and environment applications suggests tricks to improve performance.
Step forward for nanotechnology: Controlled
movement of molecules
In a step forward for
nanotechnology, scientists are reporting an advance that allows
the controlled movement of individual molecules without help from
outside forces. Shown is a model of the atomic structure of a
silicon nanocrystal.
[Credit: National Science
Foundation]
Scientists in the United Kingdom are reporting an
advance toward overcoming one of the key challenges in nanotechnology:
Getting molecules to move quickly in a desired direction without help
from outside forces. Their achievement has broad implications, the
scientists say, raising the possibility of coaxing cells to move and
grow in specific directions to treat diseases. It also could speed
development of some long-awaited nanotech innovations. They include
self-healing structures that naturally repair tears in their surface
and devices that deliver medication to diseased while sparing healthy
tissue.
Mark Geoghegan and colleagues note long-standing
efforts to produce directed, controlled movement of individual
molecules in the nano world, where objects are about 1/50,000ththe
width of a human hair. The main solutions so far have involved use of
expensive, complex machines to move the molecules and they have been
only partially successful, the scientists say.
The scientists used a special surface with
hydrophobic (water repelling) and hydrophilic (water-attracting)
sections. The region between the two sections produced a so-called "energy
gradient" which can move tiny objects much like a conveyor belt. In
lab studies, the scientists showed that plastic nanoparticles (polymer
molecules) moved quickly and in a specific direction on this surface.
"This could have implications in many technologies such as coaxing
cells to move and grow in given directions, which could have major
implications for the treatment of paralysis," the scientists said.
ACS Nano: "Directed Single Molecule Diffusion
Triggered by Surface Energy Gradients" [Article ASAP; DOI:
10.1021/nn900991r].
A potential new imaging agent for early
diagnosis of most serious skin cancer
Scientists are reporting
development and testing of a potential new material for diagnosing
malignant melanoma, the most serious form of skin cancer. Shown is
an image of melanoma on a patient?s skin.
[Credit: Wikimedia Commons]
Scientists in Australia are reporting development
and testing in laboratory animals of a potential new material for
diagnosing malignant melanoma, the most serious form of skin cancer.
Ivan Greguric and colleagues working within the
Cooperative Research Consortium for Biomedical Imaging Develop, an
Australian Government funded research group, note that about 130,000
new cases of malignant melanoma occur each year worldwide. Patients do
best with early diagnosis and prompt treatment. The positron emission
tomography (PET) scans sometimes used for diagnosis sometimes miss
small cancers, delaying diagnosis and treatment.
The scientists' search for better ways of diagnosis
led them to a new group of radioactive imaging agents, called
fluoronicotinamides, which they tested in laboratory mice that had
melanoma. The most promising substance revealed melanoma cells with
greater accuracy than imaging agents now in use, the scientists note.
As a result, this substance could become a "superior" PET imaging
agent for improving the diagnosis and monitoring the effectiveness of
treatment of melanoma, they say. Clinical trials with this new agent
are now scheduled for 2010.
Scientists are reporting discovery of a much sought
after crack in the armor of a common microbe that infects the stomachs
of one-sixth of the world's population, causing stomach ulcers and
other diseases. They identified a group of substances that block a key
chemical pathway that the bacteria need for survival. Their study,
which could lead to new, more effective antibiotics to fight these
hard-to-treat microbes, is scheduled for the October 16, 2009, issue
of ACS Chemical Biology, a monthly journal.
Javier Sancho and colleagues note in the new study
that Helicobacter pylori ( H. pylori ) bacteria infect the stomach
lining and can cause gastritis and ulcers. Treatment with
broad-spectrum antibiotics can cure H. pylori infections. However, an
estimated one billion people remain infected worldwide because of the
cost of existing antibiotics and the emergence of antibiotic resistant
strains of the bacteria, the researchers say.
The scientists knew from past research that
blocking flavodoxin, a key protein that H. pylori needs for survival,
could be the key to developing narrow-spectrum antibiotics that
specifically target H. pylori. Sancho's team screened 10,000 chemicals
for their ability to block flavodoxin and identified four that showed
promise. They then showed that three of the four substances killed H.
pylori in cell cultures and did not have any apparent toxic effects in
lab animals. "These new inhibitors constitute promising candidates to
develop new specific antibiotics against H. pylori," the study states.
Getting plants to rid themselves of pesticide
residues
Scientists in China have discovered that a natural
plant hormone, applied to crops, can help plants eliminate residues of
certain pesticides.
Jing Quan Yu and colleagues note that pesticides
are essential for sustaining food production for the world's growing
population. Farmers worldwide use about 2.5 million tons of pesticides
each year. Scientists have been seeking new ways of minimizing
pesticide residues that remain in food crops after harvest - with
little success. Previous research suggested that plant hormones called
brassinosteroids (BRs) might be an answer to the problem.
The scientists treated cucumber plants with one
type of BR then treated the plants with various pesticides, including
chloropyrifos (CPF), a broad-spectrum commercial insecticide. BR
significantly reduced their toxicity and residues in the plants, they
say. BRs may be "promising, environmentally friendly, natural
substances suitable for wide application to reduce the risks of human
and environmental exposure to pesticides," the scientists note. The
substances do not appear to be harmful to people or other animals,
they add.
'Dung of the devil' plant roots point to new
swine flu drugs
These commercial products contain
extracts from the roots of the "dung of the devil" plant. New
research says it shows promise for fighting the H1N1 swine flu
virus.
[Credit: Wikimedia Commons]
Scientists in China have discovered that roots of a
plant used a century ago during the great Spanish influenza pandemic
contains substances with powerful effects in laboratory experiments in
killing the H1N1 swine flu virus that now threatens the world. The
plant has a pleasant onion-like taste when cooked, but when raw it has
sap so foul-smelling that some call it the "Dung of the Devil" plant.
In the study, Fang-Rong Chang and Yang-Chang Wu and
colleagues note that the plant, Ferula assa-foetida, grows mainly in
Iran, Afghanistan and mainland China. People used it as a possible
remedy during the1918 Spanish flu pandemic that killed between 20 to
100 million people. Until now, however, nobody had determined whether
the plant does produce natural antiviral compounds.
Chang and Wu identified a group of chemical
compounds in extracts of the plant that showed greater potency against
influenza A (H1N1) than a prescription antiviral drug available for
the flu. "Overall, the present study has determined that sesquiterpene
coumarins from F. assa-foetida may serve as promising lead components
for new drug development against influenza A (H1N1) viral infection,"
the authors write.
Baby boomers' boon? LED light and green tea
cream to smooth facial wrinkles
A combination of LED light
exposure and green tea extract significantly reduces skin wrinkles
(right image) when compared to treatment with LED light alone,
scientists are reporting.
[Credit: Crystal Growth & Design]
Scientists in Germany are reporting a major
improvement in their potential new treatment for facial wrinkles that
could emerge as an alternative to Botox and cosmetic surgery. The
non-invasive technique combines high-intensity light from
light-emitting diodes (LEDs) and a lotion made of green tea extract.
It works ten times faster than a similar anti-wrinkle treatment that
uses LEDs alone, the researchers say.
Andrei P. Sommer and Dan Zhu point out that
researchers have used light-therapy, or phototherapy, for more than 40
years to help heal wounds. Recently the scientists showed that use of
high-intensity LEDs, similar to those used in automotive tail lights
and computers, could help reduce skin wrinkles when applied daily for
several months. But exposure to intense LED light is also involved in
generating high levels of reactive oxygen species as byproducts that
can potentially damage cells. To combat that effect, the researchers
combined the LED with a potent antioxidant in green tea extract called
epigallocatechin gallate.
They applied a daily combination of LED light and
green tea extract to the facial wrinkles of a human volunteer one
month. The combination treatment resulted in smoother skin, including
"less pronounced wrinkle levels, shorter wrinkle valleys, and juvenile
complexion," the scientists say. The treatment showed promising
results in only one-tenth of the time it took for LED therapy alone to
reduce wrinkles. The study could form the basis of "an effective
facial rejuvenation program," and lead to a new understanding of the
effect reactive oxygen species on cellular aging, they note.
Getting plants to rid themselves of pesticide
residues
Scientists have discovered that a
naturally occurring plant hormone helps plants rid themselves of
certain pesticide residues.
[Credit: USDA Agricultural
Research Service]
Scientists in China are reporting the "intriguing"
discovery that a natural plant hormone, applied to crops, can help
plants eliminate residues of certain pesticides.
Jing Quan Yu and colleagues note that pesticides
are essential for sustaining food production for the world's growing
population. Farmers worldwide use about 2.5 million tons of pesticides
each year. Scientists have been seeking new ways of minimizing
pesticide residues that remain in food crops after harvest - with
little success. Previous research suggested that plant hormones called
brassinosteroids (BRs) might be an answer to the problem.
The scientists treated cucumber plants with one
type of BR then treated the plants with various pesticides, including
chloropyrifos (CPF), a broad-spectrum commercial insecticide. BR
significantly reduced their toxicity and residues in the plants, they
say. BRs may be "promising, environmentally friendly, natural
substances suitable for wide application to reduce the risks of human
and environmental exposure to pesticides," the scientists note. The
substances do not appear to be harmful to people or other animals,
they add.
Brain cancer cells like those in
this tumor could someday become the target of nanoparticles that
in lab experiments seek out and destroy brain cancer cells without
harming healthy cells.
[Image credit: Wikimedia Commons]
In an advance toward better treatments for the most
serious form of brain cancer, scientists in Illinois are reporting
development of the first nanoparticles that seek out and destroy brain
cancer cells without damaging nearby healthy cells.
Elena Rozhkova and colleagues note the pressing
need for new ways to treat the disease, glioblastoma multiforme (GBM),
which often causes death within months of diagnosis. Recent studies
show that titanium dioxide nanoparticles, a type of light-sensitive
material widely used in sunscreens, cosmetics, and even wastewater
treatment, can destroy some cancer cells when the chemical is exposed
to ultraviolet light. However, scientists have had difficulty getting
nanoparticles, each about 1/50,000th the width of a human hair, to
target and enter cancer cells while avoiding healthy cells.
The scientists' solution involves chemically linked
titanium dioxide nanoparticles to an antibody that recognizes and
attaches to GMB cells. When they exposed cultured human GMB cells to
these so-called "nanobio hybrids," the nanoparticles killed up to 80
percent of the brain cancer cells after 5 minutes of exposure to
focused white light. The results suggest that these nanoparticles
could become a promising part of brain cancer therapy, when used
during surgery, the researchers say.
Sustainable fertilizer: Urine and wood ash
produce large harvest
Human urine and wood ash appear to make a
potent, inexpensive fertilizer combination for boosting the
productivity of food crops, scientists say.
[Credit: Wikimedia Commons]
Results of the first study evaluating the use of
human urine mixed with wood ash as a fertilizer for food crops has
found that the combination can be substituted for costly synthetic
fertilizers to produce bumper crops of tomatoes without introducing
any risk of disease for consumers. The study appears in the current
issue of ACS' Journal of Agricultural and Food Chemistry, a bi-weekly
publication.
In the study, Surendra Pradhan and colleagues point
out that urine, a good source of nitrogen, has been successfully used
to fertilize cucumber, corn, cabbage, and other crops. Only a few
studies, however, have investigated the use of wood ash, which is rich
in minerals and also reduces the acidity of certain soils. Scientists
have not reported on the combinaton of urine and wood ash, they say.
The new study found that plants fertilized with
urine produced four times more tomatoes than nonfertilized plants and
as much as plants given synthetic fertilizer. Urine plus wood ash
produced almost as great a yield, with the added benefit of reducing
the acidity of acid soils. "The results suggest that urine with or
without wood ash can be used as a substitute for mineral fertilizer to
increase the yields of tomato without posing any microbial or chemical
risks," the report says.
Powerful new 'molecular GPS' helps probe aging
and disease processes
Scientists in Michigan are reporting the
development of a powerful new probe for identifying proteins affected
by a key chemical process important in aging and disease. The probe
works like a GPS or navigation system for finding these proteins in
cells. It could lead to new insights into disease processes and
identify new targets for disease treatments, the researchers say.
Their study is scheduled for the Sept. 18 issue of ACS Chemical
Biology, a monthly journal.
Kate Carroll and colleagues note that scientists
have known for years that the excess build-up of highly-reactive
oxygen-containing molecules in cells can contribute to aging and
possibly to disorders such as cancer and Alzheimer's disease.
Scientists believe that a diet rich in antioxidants, which are
abundant in fruits and vegetables, may help deter this cell-damaging
process by blocking the accumulation of these molecules, also known as
reactive oxygen species (ROS). But until now, scientists have lacked
the proper tools to study the effects of these molecules in detail.
The researchers developed a new molecule called
DAz-2, which they say functions like a tiny GPS device for quickly
finding specific proteins that are affected by ROS. The molecules do
this by chemically "tagging" sulfenic acid. Formed in cells, sulfenic
acid indicates that a protein has undergone a type of reaction -
called oxidation - caused by ROS. In lab studies using cultured cells,
the scientists identified more than 190 proteins that undergo this
reaction. The study may lead to better strategies for fighting the
wide range of diseases that involve these excessive oxidation
reactions, the researchers say.
'NanoPen' may write new chapter in
nanotechnology manufacturing
These highly-magnified images are composed of
tiny nanoparticles produced by a "NanoPen."
[Credit: Wikimedia Commons]
Researchers in California are reporting development
of a so-called "NanoPen" that could provide a quick, convenient way of
laying down patterns of nanoparticles - from wires to circuits - for
making futuristic electronic devices, medical diagnostic tests, and
other much-anticipated nanotech applications. A report on the device,
which helps solve a long-standing challenge in nanotechnology,
appeared in ACS' Nano Letters, a monthly journal.
In the new study, Ming Wu and colleagues point out
that researchers have already developed several different techniques
for producing patterns of nanoparticles, which are barely 1/50,000th
the width of a human hair. But current techniques tend to be too
complex and slow. They require bulky instrumentation and take minutes
or even hours to complete. These techniques also require the use of
very high temperatures to apply the nanostructures to their target
surfaces. Such limitations prevent widespread application of such
techniques, the researchers say.
The scientists say their NanoPen solves these
problems. In lab studies, the researchers used it to deposit various
nanoparticles into specific patterns in the presence of relatively low
light and temperature intensities. The process, which requires the use
of special "photoconductive" surfaces, takes only seconds to complete,
they note. Manufacturers can adjust the size and density of the
patterns by adjusting the voltage, light intensity, and exposure time
applied during the process, the researchers say.
The author- or copyrights of the listed Internet pages
are held by the respective authors or site operators, who are also responsible
for the content of the presentations.
