Wissenschaftler identifizieren neuen Wirkbereich für Genregulationsenzym
Ein internationals Forscherteam konnte jetzt erstmals zeigen, dass ein Enzym zur Regulation von Genaktivität innerhalb von Histonen auch Nicht-Histon-Moleküle modifiziert und so deren Aktivität reguliert.
Strom aus Ameisensäure
Raumtemperatur genügt: Wasserstoff für Brennstoffzellen aus Ameisensäure.
Tröpfchen als Labor
Lab-on-a-Chip extrem: PCR-Schnelltest inklusive Probenvorbereitung im Taschenformat.
In a study of the molecular mechanisms by which plants protect themselves from oxidation damage should they absorb too much sunlight during photosynthesis, a team of researchers has discovered a molecular “dimmer switch” that helps control the flow of solar energy moving through the system of light harvesting proteins. The pigment-binding protein CP29, one of the “minor” light-harvesting proteins in green plants, has been identified as a valve that permits or blocks the critical release of excess solar energy during photosynthesis. Furthermore, it has been proposed that the opening and closing of this valve can be controlled by raising or lowering ambient pH levels.
Power from Formic Acid
Room temperature is warm enough: hydrogen for fuel cells from formic acid.
Arable land can have a negative impact on air quality
Farmland dust cloud from the Ukraine detected in Germany for the first time.
Researcher devises fuel that are more efficient cells, thanks to a new catalyst
A researcher has developed new materials that enable the manufacture of cheaper and more efficient methanol fuel cells.
ACS News (open access articles):
Fighting global warming - at the dinner table
Scientists report that eating
chicken, vegetables or fish, such as the swordfish above, instead
of red meat for just one meal per week does more to help fight
climate change than "buying local."
Credit: Courtesy of wikimedia
commons
Substituting chicken, fish, or vegetables for red
meat just once a week can help combat climate change - even more
dramatically than buying locally sourced food, according to scientists
in Pennsylvania who studied the environmental impacts of food
production and distribution in the United States. The study is
scheduled for the May 15 issue of ACS’s bi-weekly journal
Environmental Science & Technology.
In the study, Christopher L. Weber and H. Scott
Matthews explain that environmental advocates and retailers have urged
customers to purchase goods from local sources to minimize
environmental impacts. Despite this emphasis on “buying local,” the
researchers point out that few studies in the U. S. have compared
greenhouse gas emissions from food production to those of
transportation.
Weber and Matthews found that the production phase
dominates the average U.S. household’s greenhouse-gas burden -
contributing 83 percent of them - whereas transportation accounts for
only 11 percent. Red meat, according to the report, is almost 150
percent more greenhouse-gas-intensive than chicken or fish.
“Thus, we suggest that dietary shift can be a more
effective means of lowering an average household’s food-related
climate footprint than ‘buying local,’” the paper says. “Shifting less
than one day per week’s worth of calories from red meat and dairy
products to chicken, fish, eggs, or a vegetable-based diet achieves
more greenhouse-gas reduction than buying all locally sourced food.” -
JS
New insights on link between early consumption
of cows’ milk and Type-1 diabetes
Researchers in Maine report a new explanation for
the mysterious link between consumption of cows’ milk protein in
infant formula early in life and an increased risk of later developing
Type-1 diabetes. A protein in cow’s milk that triggers an unusual
immune response appears to be the main culprit, they say. The study is
scheduled for the June 6 issue of ACS’ monthly Journal of Proteome
Research.
In the new study, Marcia F. Goldfarb points out
that several studies have reported a possible link between the early
introduction of cow’s milk protein into an infant’s diet and
subsequent development of the disease. In Type-1 diabetes, the immune
system erroneously appears to attack and destroy insulin-producing
cells in the pancreas. It usually begins in childhood, requires
insulin injections, and afflicts about 800,000 people in the U.S.
alone. Scientists do not understand the link between cow’s milk and
diabetes. They know, however, that beta-lactoglobulin, a protein
present in cow’s milk but not found in human breast-milk, is
structurally similar to the human protein glycodelin, which controls
the production of T-cells. T-cells help guard the body against
infection.
Goldfarb describes research on patients with Type-1
diabetes, which suggests that an infant’s immature immune system may
inadvertently destroy glycodelin in an effort to destroy the similar
cow’s milk protein, which the system recognizes as foreign. This could
result in the overproduction of T-cells, which can attack the
insulin-producing cells of the pancreas and trigger diabetes, she says.
- MTS
Boosting “mussel” power: New technique for
making key marine mussel protein
By adding a certain gene to
genetically engineered bacteria, researchers have increased
production of a sticky protein from mussels that could lead to
better, cheaper antibacterial coatings.
Image by Hyung Joon Cha
Researchers in Korea report development of a way to
double production of a sticky protein from marine mussels destined for
use as an antibacterial coating to prevent life-threatening infections
in medical implants. The coating, produced by genetically-engineered
bacteria, could cut medical costs and improve implant safety, the
researchers say. Their study is scheduled for the June 6 issue of ACS’
Biotechnology Progress, a bi-monthly publication.
Bacterial infection of medical implants, such as
cardiac stents and dialysis tubing, threatens thousands of people each
year and is a major medical challenge due to the emergence of
antibiotic-resistant bacteria. Several research groups are working on
long-lasting, germ-fighting coatings from mussel proteins, but
production of these coatings is inefficient and expensive.
Hyung Joon Cha and colleagues previously developed
a way to use genetically engineered E. coli bacteria to produce mussel
adhesive proteins. Now they report adding a new gene for producing
Vitreoscilla hemoglobin (VHb), a substance that boosts production of
proteins under low-oxygen conditions. Adding the VHb gene to the
engineered E. coli doubled the amount of mussel proteins produced,
which could lead to more cost-effective coatings, the researchers say.
- MTS
Munch-o-matic: Scientists develop the artificial
mouth
A schematic representation of the
artificial mouth apparatus, which scientists have designed to
mimic human digestion.
Image: Courtesy of the American
Chemical Society.
For years scientists have tried to build an
electronic tongue, a robotic tasting device that could have profound
applications in improving food quality and safety. But before machines
learn to taste their food, they first need to learn how to chew it. In
a study scheduled for the May 14 issue of ACS’ bi-weekly Journal of
Agricultural and Food Chemistry, scientists report the design of an
artificial mouth that mimics the first vital steps of human digestion
- chewing, saliva release and the initial breakdown of food.
In the study, Gaëlle Arvisenet and colleagues point
out that a number of factors are involved in the release of aromatic
and flavor compounds in the mouth. Chewing, the release of saliva, the
rate of food breakdown and the temperature all affect the flavor and
smell of food before it’s swallowed. To accurately reproduce the
effects of chewing, Arvisenet's team needed to build a machine that
could imitate several - if not all - of these subtle processes. “Our
aim was not to reproduce the human mouth conditions exactly, but to
reproduce the result of mastication,” says Arvisenet.
The researchers compared apples chewed by their
machine and by human mouths. The resulting apple pulp was scrutinized
for texture, color and aromatic compound release. “Experimental
conditions were determined that produced fruit in a state closest to
that obtained after mastication in a human mouth,” reports Arvisenet.
- AD
No more needles: Toward an artificial pancreas
for fighting diabetes
A specially coated metal tube, no larger than a
cigarette, could be the key to developing an artificial pancreas to
help millions of people with diabetes avoid insulin injections,
according to an article scheduled for the May 5, 2008 issue of
Chemical & Engineering News, ACS’ weekly newsmagazine. The so-called
“bioartificial pancreas” also could help keep blood sugar closer to
normal levels, and perhaps reduce the risk of diabetic complications,
which include blindness, kidney failure, and premature death, the
article suggests.
Written by Associate Editor Bethany Halford, the
C&EN article points out that researchers have been trying to develop
an artificial pancreas for years. Most approaches involve
encapsulating healthy islet cells - the pancreatic cells that detect
glucose and release insulin - and transplanting them into diabetic
patients. But enclosing a large collection of cells has been difficult
because the materials designed to hold them are not biocompatible, or
optimal for use in the body, Halford notes.
The new device, developed by Joseph P. Kennedy and
colleagues at the University of Akron in Ohio, is coated with a
permeable polymer membrane that is key to its success. In addition to
improving the exchange of insulin and glucose between the islet cells
and the blood, the polymer membrane helps increase the supply of
oxygen to the cells for improved function and lifespan. The device
itself has already shown promise in preliminary animal studies and
researchers are looking ahead to clinical trials in humans, the
article notes.
