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We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

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+ - Material Made From Crustaceans Could Combat Military Mortalities->

Submitted by MTorrice
MTorrice (2611475) writes "A foam composed of a polymer derived from crustacean shells may prevent more soldiers from falling victim to the most prolific killer on the battlefield: blood loss.

Pressure is one of the best tools that medics have to fight bleeding, but they can’t use it on severe wounds near organs. Here, compression could do more harm than good. First responders have no way to effectively dam blood flows from these noncompressible injuries, which account for the majority of hemorrhagic deaths. The new foam could help stop bleeding in these types of injuries.

It relies on chitosan, a biopolymer that comes from processed crustacean shells. By modifying the chitosan, the developers gave the material the ability to anchor blood cells into gel-like networks, essentially forming blood clots. The researchers dispersed the modified chitosan in water to create a fluid they could spray directly onto noncompressible wounds."

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+ - Some Biodegradable Plastics Don't Live Up To Their Claims-> 1

Submitted by ckwu
ckwu (2886397) writes "From bread bags to beverage bottles, many plastics now contain additives designed to make the materials biodegradable. But a new study shows that plastics made with such additives do not biodegrade in the environment significantly faster than those without the compounds. Researchers prepared films of commercial plastics with three different types of additives supplied by their manufacturers. The researchers then treated the film samples to mimic disposal of such plastics in a compost pile, a landfill, and soil. After about six months of composting, a year and a half of landfill-like conditions, and three years of soil burial, the plastics with additives did not show any more evidence of biodegradation than plastics without them."
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+ - Helping Brains Relieve Anxiety On Their Own->

Submitted by MTorrice
MTorrice (2611475) writes "A new study suggests a strategy to treat anxiety might be to design drugs that help the brain’s own regulatory circuitry kick in and tune down hyperactive neurons.

The study’s authors focus on a part of the brain that processes fear and other emotions—the amygdala. In people with anxiety disorders, the amygdala can become hyperactive, and one explanation for the elevated activity is disruption of endocannabinoid signaling. Endocannabinoids are lipids that hit the same brain receptors targeted by THC, the active chemical in marijuana. The greasy molecules help make sure nerve cells don't become overly excited or too lethargic.

In anxious mice, the researchers found the amygdala plays host to an overactive enzyme that disrupts endocannabinoid signaling. Inhibiting the unruly enzyme with a drug-like compound restores the circuit and stops anxious behavior in mice."

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+ - 100 Years of Chemical Weapons->

Submitted by MTorrice
MTorrice (2611475) writes "This year marks the 100th anniversary of the first large-scale use of chemical weapons during World War I. Sarah Everts at Chemical & Engineering News remembers the event with a detailed account of the day in 1915 when the German Army released chlorine gas on its enemies, igniting a chemical arms race. Read the diaries of soldiers involved in the first gas attack.

By the end of WWI, scientists working for both warring parties had evaluated some 3,000 different chemicals for use as weapons. Even though poison gas didn’t end up becoming an efficient killing weapon on WWI battlefields—it was responsible for less than 1% of WWI’s fatalities--its adoption set a precedent for using chemicals to murder en masse. In the past century, poison gas has killed millions of civilians around the world: commuters on the Tokyo subway, antigovernment demonstrators in Syria, and those incarcerated in Third Reich concentration camps. Everts profiles chemist Fritz Haber, the man who lobbied to unleash the gas that day in 1915."

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+ - Fantastic Voyage: Self-Propelled Micromotors Swim In Mouse Stomachs->

Submitted by MTorrice
MTorrice (2611475) writes "The idea sounds like something out of a science-fiction novel: Tiny medical machines zooming around the body delivering drugs, taking tissue samples, or performing small surgical repairs. But, now, for the first time, researchers have demonstrated a simple micromotor that can propel itself inside the body. When introduced into a mouse’s stomach, the micromotor swims to the stomach lining and delivers cargo.

The motors are 20-micron-long, 5-micron-wide cylindrical tubes made from a biocompatible polymer and filled with zinc. The zinc reduces hydrogen ions to produce bubbles of hydrogen gas. Inside the stomachs of mice, the tubes react with ions in gastric acids to swim around and penetrate the mucus layer on the stomach surface."

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+ - Deep-Frying Graphene Microspheres For Energy Storage->

Submitted by ckwu
ckwu (2886397) writes "Materials scientists have constructed round, pom-pom-like graphene microparticles by spraying graphene oxide droplets into a hot solvent—a process akin to deep-frying. The technique could provide a simple, versatile means to make electrode materials for batteries and supercapacitors, possibly leading to devices with improved energy and power densities, the researchers say. The microparticles contain graphene nanosheets radiating out from their centers, which increases the exposed surface area of the graphene and creates open nanochannels that can enhance charge transfer. Electrodes made with the graphene microspheres had higher capacitance than those made with unassembled graphene sheets, demonstrating that the 3-D structure of the particles improved performance."
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+ - Record-Breaking Nanowire Transistors->

Submitted by MTorrice
MTorrice (2611475) writes "With the functional size limit for silicon transistors fast approaching, researchers are working on transistor designs that rely on materials with better electrical properties than silicon. Now researchers have made high-performance transistors from a promising candidate material: gallium arsenide nanowires.

GaAs is a III/V semiconductor—each member of the family contains an element from the third and fifth columns of the periodic table. These materials have higher charge mobility than silicon, which should allow III/V transistors to switch on and off faster than silicon-based devices.

The nanowire transistors have fast switching speeds, turning on and off 75 billion times a second, or at 75 GHz. The previous record for planar nanowire transistors was 1.8 GHz.
 "

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+ - Flexible White Organic LEDs Achieve Record Efficiencies->

Submitted by MTorrice
MTorrice (2611475) writes "One challenge for achieving high-efficiency organic light-emitting diodes (OLEDs) is making flexible transparent electrodes. The brittle indium tin oxide (ITO) electrodes used in conventional glass devices cannot be used in bendable applications such as roll-up displays. So researchers have explored electrodes made of carbon nanotubes, graphene, and silver nanowires. Now materials scientists have built large, flexible organic light-emitting diodes (OLEDs) that shine white light with record-high efficiency thanks to a new method for making transparent electrodes with silver networks.

The embedded silver electrodes are highly transparent, transmitting more than 88% of light hitting them. They also have a low electrical resistance of 4.7 ohms per square, which is better than the 15 to 20 ohms per square of other reported silver nanowire electrodes, or even ITO-based ones."

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+ - U.S. Passenger Vehicle Fleet Dirtier After 2008 Recession->

Submitted by MTorrice
MTorrice (2611475) writes "The 2008 recession hammered the U.S. auto industry, driving down sales of 2009 models to levels 35% lower than those before the economic slump. A new study has found that because sales of new vehicles slowed, the average age of the U.S. fleet climbed more than expected, increasing the rate of air pollutants released by the fleet.

In 2013, the researchers studied the emissions of more than 68,000 vehicles on the roads in three cities—Los Angeles, Denver, and Tulsa. They calculated the amount of pollution released per kilogram of fuel burned for the 2013 fleet and compared the rates to those that would have occurred if the 2013 fleet had the same age distribution as the prerecession fleet. For the three cities, carbon monoxide emissions were greater by 17 to 29%, hydrocarbons by 9 to 14%, nitrogen oxide emissions by 27 to 30%, and ammonia by 7 to 16%."

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+ - Pantry Pests Harbor Plastic-Chomping Bacteria->

Submitted by MTorrice
MTorrice (2611475) writes "In the U.S. alone, consumers discard over 32 million tons of plastic each year, only 9% of which is recycled. Polyethylene is one of the most popular and, unfortunately, persistent types of plastics. Bags, bottles, and packaging made from the polymer accumulate in landfills and oceans across the globe. Scientists have lamented that the material isn't biodegradable because microbes can’t chew up the plastic to render it harmless. However, a new study reports the first definitive molecular evidence that two species of bacteria, found in the guts of a common pantry pest, can thrive on polyethylene and break it apart."
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+ - European Nations Release Troubling Levels Of Chemicals->

Submitted by MTorrice
MTorrice (2611475) writes "An ecological footprint is a popular metric that shows the amount of natural resources required to provide raw materials and food to sustain an individual or a country. Comparing the footprint to what nature actually can provide allows people to easily grasp their impact on the environment.

Now, researchers report the first methods for calculating a chemical footprint to explain how the mix of chemicals released into the environment affects ecosystem health. The footprint describes how much freshwater is needed to dilute all of the chemicals released by a country to safe levels.

Analyses using these indicators suggest that most European countries don’t have enough freshwater in their rivers and lakes to dilute their chemical pollution to safe levels for their aquatic ecosystems."

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+ - Researchers Direct Growth Of Neurons With Silicon Nitride Microtubes->

Submitted by MTorrice
MTorrice (2611475) writes "Bioengineers want to connect electronics and neurons to make devices such as new cochlear implants or prosthetic limbs with a seemingly natural sense of touch. They also could build synthetic neural circuitry to use to study how the brain processes information or what goes wrong in neurodegenerative diseases.

As a step toward these applications, a team of researchers has developed a way to direct the growth of axons, the connection-forming arms of neurons. They use transparent silicon nitride microtubes on glass slides to encourage the cells’ axons to grow in specific directions. The cultured nerve cells grow aimlessly until they bump into one of the tubes. The axon then enters the tube, and its growth is accelerated 20-fold.

Silicon nitride already is used in some orthopedic devices, and could serve as a substrate for electronics to interface with the growing neurons.

 "

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Comment: Re:Nature scraping (Score 5, Informative) 77

Usually the compound in your pill is not the compound someone fished out of a microbe. It's been modified to give it better pharmacological properties--last longer in your bloodstream--and to avoid toxicity issues. So there is a lot of intellectual work that goes into making the compound you ingest even if the initial inspiration came from a fungus.

Comment: Re:Nature scraping (Score 4, Insightful) 77

No one takes a molecule from a bacterium or fungus and then starts giving it to patients. You have to find the specific compound that allows the fungus/bacterium to kill its neighbors--a very labor intensive process. Then you have to get its structure. Then you test it to see if is druggable--will it last long enough in the bloodstream to be effective, for example. It probably isn't, so then you need to synthesize analogs and test them. Then you have to test it for toxicity, maybe synthesize more analogs to get around toxicity problems. And then you can start clinical trials--three rounds of them usually. Somewhere along the way you need to devise a way to make the compound in large enough quantities to turn it into a pill or injection or whatever deliverable form you're picking. So there are a lot of steps between "hey this compound from this fungus killed that bacteria," and "take this pill once a day for 10 days."

To err is human -- to blame it on a computer is even more so.

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