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Thursday, 11 July 2013

Supercooled Water Transforms Into New Form of Liquid

Researchers at the University of Arkansas have identified that water, when chilled to a very low temperature, transforms into a new form of liquid.

Through a simulation performed in “supercooled” water, a research team led by chemist Feng “Seymour” Wang, confirmed a “liquid-liquid” phase transition at 207 Kelvins, or 87 degrees below zero on the Fahrenheit scale.

Water and ice (stock image). Researchers have identified that water, when chilled to a very low temperature, transforms into a new form of liquid. (Credit: © Oscar Espinosa / Fotolia)

Wednesday, 10 July 2013

3-D Structures Built out of Liquid Metal

Researchers from North Carolina State University have developed three-dimensional (3-D) printing technology and techniques to create free-standing structures made of liquid metal at room temperature.
Researchers have developed three-dimensional structures out of liquid metal. Image: Michael Dickey.


“It’s difficult to create structures out of liquids, because liquids want to bead up. But we’ve found that a liquid metal alloy of gallium and indium reacts to the oxygen in the air at room temperature to form a ‘skin’ that allows the liquid metal structures to retain their shapes,” says Dr. Michael Dickey, an assistant professor of chemical and biomolecular engineering at NC State and co-author of a paper describing the work.

Wednesday, 3 July 2013

Fluorescent Fingerprint Tag Aims to Increase IDs from 'Hidden' Prints On Bullets and Knives

A new way of detecting and visualizing fingerprints from crime scenes using colour-changing fluorescent films could lead to higher confidence identifications from latent (hidden) fingerprints on knives, guns, bullet casings and other metal surfaces. The technique is the result of a collaboration between the University of Leicester, the Institut Laue-Langevin and the STFC's ISIS pulsed neutron and muon source, and will be presented today at the Royal Society of Chemistry's Faraday Discussion in Durham.
Images of a fingermark left on a stainless steel substrate, following enhancement by electrodeposition of polypyrrole. The light regions are stainless steel that was protected by the sweat residue that was laid on top, preventing the polymer depositing onto it. The dark regions are the polymer in between the fingerprint sweat without the fluorescence 'turned on.' (Credit: University of Leicester)
Credit: http://www.eurekalert.org

Tuesday, 2 July 2013

Better Antibiotics: Atomic-Scale Structure of Ribosome With Molecule That Controls Its Motion

This may look like a tangle of squiggly lines, but you’re actually looking at a molecular machine called a ribosome. Its job is to translate DNA sequences into proteins, the workhorse compounds that sustain you and all living things.

The image is also a milestone. It’s the first time the atom-by-atom structure of the ribosome has been seen as it’s attached to a molecule that controls its motion. That’s big news if you’re a structural biologist.
 
Ribosome. (Credit: Image courtesy of DOE/Lawrence Berkeley National Laboratory)

Monday, 1 July 2013

Tiny Nanocubes Help Scientists Tell Left from Right

In chemical reactions, left and right can make a big difference. A "left-handed" molecule of a particular chemical composition could be an effective drug, while its mirror-image "right-handed" counterpart could be completely inactive. 

That's because, in biology, "left" and "right" molecular designs are crucial: Living organisms are made only from left-handed amino acids. So telling the two apart is important—but difficult.

Electron microscopy "maps" of octahedral gold nanoparticles surrounded by cubic silver shells. Attaching a biomolecule (e.g., DNA) to these nanoparticles strengthens a signal representing a difference between left- and right-handed molecules' response to light by 100 times, and pushes it toward the visible range of the electromagnetic spectrum. (Credit: Image courtesy of Brookhaven National Laboratory)