Researchers from the NIST Center for Nanoscale Science and Technology have observed electromagnetically induced transparency at room temperature and atmospheric pressure in a silicon nitride optomechanical system. This work highlights the potential of silicon nitride as a material for producing integrated devices in which mechanical vibrations can be used to manipulate and modify optical signals.
An unwanted byproduct from a bygone method of...
A new tool for analyzing mountains of data from SLAC National Accelerator Laboratory’s Linac...
Computational biologists in Austria have recently shown that the common practice of averaging is not always a good thing when it comes to analyzing protein crystal structures. A study shows that protein structures could be more dynamic and heterogeneous than current methods of x-ray analysis suggest.
Lawrence Berkeley National Laboratory researchers have produced the first detailed look at the 3-D structure of the Cas9 enzyme and how it partners with guide RNA to interact with target DNA. The results should enhance Cas9’s value and versatility as a genome-editing tool.
The sponges of the future will do more than clean house. Picture this, for example: Doctors use a tiny sponge to soak up a drug and deliver it directly to a tumor. Chemists at a manufacturing plant use another to trap and store unwanted gases. These technologies are what a Univ. at Buffalo team had in mind when they led the design of a new material called UBMOF-1.
A research group based in Japan has succeeded for the first time in fabricating a 3-D structure of a quasicrystal composed of a single element. Discovered in 1984, quasicrystals have been found in more than 100 kinds of alloy, polymer and nanoparticle systems. However, a quasicrystal composed of a single element has not yet been found.
Researchers have combined cutting-edge experimental techniques and computer simulations to find a new way of predicting how water dissolves crystalline structures like those found in natural stone and cement. The research could have wide-ranging impacts in diverse areas, including water quality and planning, environmental sustainability, corrosion resistance and cement construction.
Scientists from NIST and Sandia National Laboratories have added something new to a family of engineered, high-technology materials called metal-organic frameworks (MOFs): the ability to conduct electricity. This breakthrough—conductive MOFs—has the potential to make these already remarkable materials even more useful, particularly for detecting gases and toxic substances.
An interdisciplinary team of University of Pennsylvania researchers has already developed a technique for controlling liquid crystals by means of physical templates and elastic energy, rather than the electromagnetic fields that manipulate them in televisions and computer monitors. They envision using this technique to direct the assembly of other materials, such as nanoparticles.
New York Univ. chemists have discovered crystal growth complexities, which at first glance appeared to confound 50 years of theory and deepened the mystery of how organic crystals form. But, appearances can be deceiving. The researchers focused on L-cystine crystals, the chief component of a particularly nefarious kind of kidney stone.
Researchers at the Virginia Tech Carilion Research Institute have reported the first experimental evidence that supports the theory that a soccer ball-shaped nanoparticle, commonly called a buckyball, is the result of a breakdown of larger structures rather than being built atom-by-atom from the ground up.
Computer simulations conducted at Lawrence Berkeley National Laboratory could help scientists make sense of a recently observed and puzzling wrinkle in one of nature’s most important chemical processes. It turns out that calcium carbonate may momentarily exist in liquid form as it crystallizes from solution.
By determining the 3-D structure of proteins at the atomic level, researchers at the National Institutes of Health have discovered how some commonly used flame retardants, called brominated flame retardants (BFRs), can mimic estrogen hormones and possibly disrupt the body’s endocrine system. BFRs are chemicals added or applied to materials to slow or prevent the start or growth of fire.
A new study from an international team led by Oak Ridge National Laboratory is guiding drug designers toward improved pharmaceuticals to treat HIV. The scientists used neutrons and x-rays to study the interactions between HIV protease, a protein produced by the HIV virus, and an antiviral drug commonly used to block virus replication.
Researchers have been investigating the formation of defects occurring when a Coulomb crystal of ions is driven through a second-order phase transition. This process effectively models the universal Kibble-Zurek mechanism which describes the formation of such defects and is the basis of one theory of how matter was created 10-30 seconds after the Big Bang.
Nanocrystals can grab specific molecules and particles out the air, hold on to them and then release them. But progress in utilizing adsorption and desorption has been hindered by limitations in existing methods for measuring the physical and chemical changes that take place in individual nanocrystals. A newly developed system may solve this by directly measuring the manner in which nanocrystals adsorb and release hydrogen and other gases.
In some ways, granular material can behave much like a crystal, with its close-packed grains mimicking the precise, orderly arrangement of crystalline atoms. Now researchers at Massachusetts Institute of Technology have pushed that similarity to a new limit, creating 2-D arrays of micrograins that can funnel acoustic waves, much as specially designed crystals can control the passage of light or other waves.
Chemists have unexpectedly made two differently colored crystals—one orange, the other blue—from one chemical in the same flask while studying a special kind of molecular connection called an agostic bond. The discovery is providing new insights into important industrial chemical reactions such as those that occur while making plastics and fuels.
If you squeeze a normal object in all directions, it shrinks in all directions. But a few strange materials will actually grow in one dimension when compressed. A team of chemists has now discovered a structure that takes this property to a new level, expanding more dramatically under pressure than any other known material.
Lawrence Livermore National Laboratory researchers, for the first time, have created movies of irreversible reactions that occur too rapidly to capture with conventional microscopy. The team used multiframe, nanosecond-scale imaging in the dynamic transmission electron microscope to create movies of the crystallization of phase-change materials used for optical and resistive memory.
Scientists at Ames Laboratory have discovered a new family of rare-earth quasicrystals using an algorithm they developed to help pinpoint them. Quasicrystalline materials may be found close to crystalline phases that contain similar atomic motifs, called crystalline approximants. And just like fishing experts know how to hook a big catch, the scientists used their knowledge to hone in on the right spot for their discovery.
An international collaboration of scientists has discovered a unique crystalizing behavior at the interface between two immiscible liquids that could aid in sustainable energy development. Liquid interface behavior cannot be investigated at atomic level by most modern methods. Only brilliant X-rays at world-leading light sources can investigate this type of important chemical processes.
With the hand of nature trained on a beaker of chemical fluid, the most delicate flower structures have been formed in a Harvard University laboratory—and not at the scale of inches, but microns. These minuscule sculptures, curved and delicate, don't resemble the cubic or jagged forms normally associated with crystals, though that's what they are. Rather, fields of flowers seem to bloom from the surface of a submerged glass slide.
A Purdue University-led team has revealed the proton transfer pathway responsible for a majority of energy storage in photosynthesis. The team used X-ray crystallography to describe the molecular structure of the cytochrome complex isolated from cyanobacteria, the most primitive photosynthetic organism. The findings contribute to the understanding of the function of photosynthesis and that of membrane proteins.
More powerful batteries could help electric cars achieve a considerably larger range and thus a breakthrough on the market. A new nanomaterial made from tiny tin crystals, deployed at the anode of lithium-ion batteries, has been developed in the labs of chemists in Europe and enables considerably more power to be stored in these batteries.
Quasiperiodic structures, or quasicrystals, because of their unique ordering of atoms and a lack of periodicity, possess remarkable crystallographic, physical and optical properties not present in regular crystals. Researchers at Syracuse University have recently authored a paper that presents the history of quasicrystals and how this area can open up numerous opportunities in fundamental optics research.
When a crystal is hit by an intense, ultrashort light pulse, its atomic structure is set in motion. Researchers in Germany have used intensive ultraviolet laser pulses of only a few femtoseconds duration to cause this change in titanium dioxide, a semiconductor. They report that they can observe how the configuration of electrons and atoms changes, confirming that even subtle changes in the electron distribution caused by the excitation can have a considerable impact on the whole crystal structure.
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