Category Chemistry/Nanotechnology

Bacteria’s Secret Weapon Against Pesticides, Antibiotics Revealed

A. This image shows methyl phosphate. B. Methyl phosphonate. Phosphonate compounds are characterized by a direct link between carbon (C) and phosphorus (P), marked with red. C. The molecular structure of the C-P lyase complex. Credit: Ditlev E. Brodersen, Aarhus University

A. This image shows methyl phosphate. B. Methyl phosphonate. Phosphonate compounds are characterized by a direct link between carbon (C) and phosphorus (P), marked with red. C. The molecular structure of the C-P lyase complex. Credit: Ditlev E. Brodersen, Aarhus University

Bacteria exhibit extreme adaptability, which makes them capable of surviving in the most inhospitable conditions. New research results produced by Danish and British researchers now reveal the molecular details behind one of the secret weapons used by bacteria in their battle to survive under very nutrient-poor and even toxic conditions.

All living things need phosphate to grow, which is why several hundred million tons of phosphate fertilisers are used every year in agriculture throughout the world...

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Dancing Droplets Launch themselves from Thin Hydrophobic Fibers

Figure 1

The discovery may aid Water Purification and Oil Refining. Researchers have observed droplets spontaneously fling themselves from thin fibers. As long as the strands are moderately hydrophobic and relatively thin, small droplets combining into one are apt to dance themselves right off of the tightrope.

“We were studying how insect wings with a hairy structure clean themselves, and an undergrad Adam Williams saw two droplets merge and suddenly leave a strand of hair,” said Chuan-Hua Chen, associate professor of mechanical engineering and materials science at Duke. “Since we couldn’t easily reproduce the effect, we thought it was just an artifact, perhaps due to the slight breeze created by the humidifier in the experiment.”

IMAGES: self-propelled removal of drops from a hydrophobic fiber, where the surface energy released upon drop coalescence overcomes the drop-fiber adhesion, producing spontaneous departure that would not occur on a flat substrate of the same contact angle. The self-removal takes place above a threshold drop-to-fiber radius ratio, and the departure speed is close to the capillary-inertial velocity at large radius ratios.

IMAGES: self-propelled removal of drops from a hydrophobic fiber, ...

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Glass Paint could keep Metal Roofs and other Structures Cool even on Sunny Days

To fend off damage and heat from the sun’s harsh rays, scientists have developed a new, environmentally friendly paint out of glass that bounces sunlight off metal surfaces – keeping them cool and durable. “Most paints you use on your car or house are based on polymers, which degrade in the ultraviolet light rays of the sun,” says Jason J. Benkoski, Ph.D. “So over time you’ll have chalking and yellowing. Polymers also tend to give off volatile organic compounds, which can harm the environment. That’s why I wanted to move away from traditional polymer coatings to inorganic glass ones.”
Glass, which is made out of silica, would be an ideal coating. It’s hard, durable and has the right optical properties. But it’s very brittle.

Benkoski, at Johns Hopkins University Applied Physics Lab, modif...

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Unlikely element turns up in Enzyme; Commercial Renewable Fuels might Ultimately Result

Tungsten is exceptionally rare in biological systems. Thus, it came as a huge surprise to researchers when they discovered this novel enzyme in hot spring-inhabiting bacterium, Caldicellulosiruptor bescii. This tungstoenzyme plays a key role in C. bescii’s primary metabolism, and its ability to convert plant biomass to simple fermentable sugars which could lead to commercially viable conversion of cellulosic (woody) biomass to fuels and chemical feedstocks, which could substantially reduce greenhouse emissions.

Cellulosic biomass’ advantage as a feedstock for fuel and chemical production is that it need not compete with food production for land. Its big challenge is that cellulose is highly resistant to enzymatic degradation...

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