APXPS Finds Carbonate Reversal at Liquid Interfaces (5/26/2017) - Aqueous carbonate systems are central to many processes essential to life, from the blood buffer system to the global carbon cycle. Using APXPS, researchers probed the concentration of carbonates near an interface, finding a surprising reversal in the expected abundances as a function of depth.
A Closer Look at a Working Platinum/Electrolyte Interface (5/24/2017) - Ambient-pressure studies of the interface between a platinum electrode and an alkaline electrolyte revealed the molecular-level chemistry, structure, and dynamics of the platinum surface as a function of applied potential, highlighting differences between thermodynamic predictions and the actual surface composition.
A Hollow Pyramid Unlocks Principles of Protein Architecture (5/22/2017) - Researchers have designed a hollow, pyramid-shaped protein with a controllable cavity size that could be useful in the capture and release of smaller compounds. The tools and techniques developed could be useful in analyzing and optimizing designed protein assemblies and understanding their behavior in solution.
Strain Turns Tin into a 3D Topological Dirac Semimetal (5/11/2017) - A small amount of compressive strain turns a nonmetallic form of tin into a 3D topological Dirac semimetal—a kind of "supermetal" with very high electron mobility. With its rich topological phase diagram, the material shows promise for both novel physics and eventual device applications.
Electronic Phase Separation and Dramatic Inverse Band Renormalization in the Mixed-Valence Cuprate LiCu2O2 (4/28/2017) - Angle-resolved photoemission spectroscopy was used to measure the electronic structure of LiCu2O2, a mixed-valence cuprate where planes of Cu(I) (3d10) ions are sandwiched between layers containing one-dimensional edge-sharing Cu(II) (3d9) chains.
Modulating Infrared Light with 2D Black Phosphorus (4/24/2017) - Two-dimensional materials represent a promising new frontier in the field of optoelectronics. Most progress so far, however, has been in the visible-light range. Now, at the ALS, researchers have measured the infrared transmission spectra of ultrathin samples of black phosphorus under an applied electric field.
New Insights into Nanoscale Deformation (4/20/2017) - A group of scientists used Laue x-ray microdiffraction at the ALS to probe plastic deformation mechanisms at the nanoscale. Their findings may overturn conventional theory and reshape our understanding of the mechanical behavior of a host of nanocrystalline metals.
3D Visualization of Leaves during Drought (4/18/2017) - The veins of living leaves at increasing levels of drought stress were visualized using x-ray microtomography. The results expand our view of leaf drought responses, beyond the traditional embolism-centric view, to a broader focus on the role of the surrounding living tissues in water movement during drought.
Bending the (β-Sheet) Curve to Shape Protein Cavities (4/14/2017) - Curved β sheets are basic building blocks of many protein cavities that, by serving as binding sites for other molecules, are essential to protein function. β-sheet curvature can now be controlled with atomic-level accuracy, opening the door to custom-designed sites capable of entirely new functions.
Ancient Ocean Temperatures Recorded in Mother-of-Pearl (3/27/2017) - Researchers have shown that the thickness of the nacre, or mother-of-pearl, that lines the insides of mollusk shells can be used to estimate ocean temperatures as far back as the early Jurassic period. X-ray studies of modern and ancient shells help establish the method's feasibility.