A mysterious space within a protein critical to photosynthesis is filled with fat molecules that influence both the protein’s architecture and electrical properties, according to two recent studies. Researchers studied the atomic structure of, and electrical interactions within, the cytochrome bf complex, a protein complex central to the transport of electrons within membranes of a plant cell, a critical step in photosynthesis.
A novel x...
Experiments at SLAC National Accelerator Laboratory solve a long-standing mystery in the role calcium atoms serve in a chemical reaction that releases oxygen into the air we breathe. The results offer new clues about atomic-scale processes that drive the life-sustaining cycle of photosynthesis and could help forge a foundation for producing cleaner energy sources by synthesizing nature's handiwork.
Purdue Univ. researchers have discovered the structure of the enzyme that makes cellulose, a finding that could lead to easier ways of breaking down plant materials to make biofuels and other products and materials. The research also provides the most detailed glimpse to date of the complicated process by which cellulose is produced.
The liver provides critical functions, such as ridding the body of toxins, but its failure can be deadly, and there are few options for fixing it. A promising alternative in development is transplanting liver cells made using adult stem cells, but the only source identified until now has been bone marrow. Recently, scientists identified another, more convenient, source of adult stem cells that could be used for this purpose:tonsils.
Manufactures of turbine engines for airplanes, automobiles and electric generation plants could expedite the development of more durable, energy-efficient turbine blades thanks to a partnership between Argonne National Laboratory, the German Aerospace Center and the universities of Central Florida and Cleveland State. The ability to operate turbine blades at higher temperatures improves efficiency and reduces energy costs.
Sugar is a vital source of energy. Understanding just how sugar makes its way into the cell could lead to the design of better drugs for diabetes patients and an increase in the amount of fruits and vegetables farmers are able to grow. Stanford Univ. researchers have recently uncovered one of these "pathways” into the cell by piecing together proteins slightly wider than the diameter of a strand of spider silk.
A comprehensive look at how tiny particles in a lithium-ion battery electrode behave shows that rapid-charging the battery and using it to do high-power, rapidly draining work may not be as damaging as researchers had thought—and that the benefits of slow draining and charging may have been overestimated.
A team of Lawrence Berkeley National Laboratory researchers believes it has uncovered the secret behind the unusual optoelectronic properties of single atomic layers of transition metal dichalcogenide (TMDC) materials, the 2-D semiconductors that hold great promise for nanoelectronic and photonic applications.
Plastics are made of polymers, which are a challenge for scientists to study. Their chain-like strands of thousands of atoms are tangled up in a spaghetti-like jumble, their motion can be measured at many time scales and they are essentially invisible to some common x-ray study techniques. A better understanding of polymers at the molecular scale could lead to improved manufacturing techniques and the creation of new materials.
A record-setting x-ray microscopy experiment may have ushered in a new era for nanoscale imaging. Working at Lawrence Berkeley National Laboratory (Berkeley Lab), a collaboration of researchers used low energy or “soft” x-rays to image structures only 5 nm in size. This resolution, obtained at Berkeley Lab’s Advanced Light Source, is the highest ever achieved with x-ray microscopy.
Using an "electric prism", or deflector, scientists have found a new way of separating water molecules that differ only in their nuclear spin states and, under normal conditions, do not part ways. Since water is such a fundamental molecule in the universe, the recent study may impact a multitude of research areas ranging from biology to astrophysics.
Accurately examining materials in liquids using electron microscopy is a difficult task for scientists, as electron beams perturb the sample and induce artifacts. Scientists at Pacific Northwest National Laboratory and the Univ. of California, Davis have demonstrated that in in situ liquid experiments, the choice of electron beam energy has a strong effect that goes far beyond merely increasing the concentration of reducing radicals.
Scientists have for the first time mapped the atomic structure of a protein within a living cell. The technique, which peered into cells with an x-ray laser, could allow scientists to explore some components of living cells as never before.
Scientists’ underwater cameras got a boost this summer from the Electron Microscopy Center at Argonne National Laboratory. Along with colleagues at the Univ. of Manchester, researchers captured the world’s first real-time images and simultaneous chemical analysis of nanostructures while “underwater,” or in solution.
Only recently has it become possible to accurately “see” the structure of a liquid. Using x-rays and a high-tech apparatus that holds liquids without a container, a professor at Washington Univ. in St. Louis was able to compare the behavior of glass-forming liquids as they approach the glass transition.
The field of astrophysics has a stubborn problem and it’s called lithium. The quantities of lithium predicted to have resulted from the Big Bang are not actually present in stars. But the calculations are correct, a fact which has now been confirmed for the first time in experiments conducted at the underground laboratory in the Gran Sasso mountain in Italy.
One of nature’s mysteries is how plants survive impact by the huge amounts of energy contained in the sun’s rays, while using this energy for photosynthesis. The hypothesis is that the light-absorbing proteins in the plant’s blades quickly dissipate the energy throughout the entire protein molecule through so-called protein “quakes”. Researchers have now managed to successfully “film” this process.
Research published last week in Science suggested that the makeup of the Earth's lower mantle, which makes up the largest part of the Earth by volume, is significantly different than previously thought. According to scientists, the work performed at Argonne National Laboratory’s Advanced Photon Source will have a significant impact on our understanding of the lower mantle.
A team of scientists from Germany, Canada, and the United States has now developed a promising new measurement method that works without destroying anything yet offers nanoscale resolution. The method, an enhancement of resonant x-ray reflectometry identifies the chemical elements involved and is able to determine both the magnetic order and the electron distribution.
Scientists have, for the first time, characterized so-called quantum vortices that swirl within tiny droplets of liquid helium. The research, led by scientists at Lawrence Berkeley National Laboratory, the Univ. of Southern California and SLAC National Accelerator Laboratory, confirms that helium nanodroplets are in fact the smallest possible superfluidic objects and opens new avenues for studying quantum rotation.
Earth’s magnetic field, a familiar directional indicator over long distances, is routinely probed in applications ranging from geology to archaeology. Now it has provided the basis for a technique which might, one day, be used to characterize the chemical composition of fluid mixtures in their native environments.
Rice Univ. scientists have won a race to find the crystal structure of the first virus known to infect the most abundant animal on Earth. The Rice laboratories of structural biologist Yizhi Jane Tao and geneticist Weiwei Zhong, with help from researchers at Baylor College of Medicine and Washington Univ., analyzed the Orsay virus that naturally infects a certain type of nematode, the worms that make up 80% of the living animal population.
The human brain harbors far more copper, iron and zinc than anywhere else in the body. Abnormally high levels of these metals can lead to disorders such as Alzheimer’s and Parkinson’s diseases. Chris Chang, a faculty chemist with Berkeley Lab’s Chemical Sciences Div., has spent the past several years developing new probes and techniques for imaging the molecular activity of these metals in the brain.
The “Bearded Man, 170-180 A.D.” is a Roman-Egyptian portrait that adorned the sarcophagus sheltering his mummified remains. The details of who he was have been lost to time, but a microscopic sliver of painted wood could hold the keys to unraveling the first part of this centuries-old mystery. Figuring out what kind of pigment was used, and the exact materials used to create it, could help scientists unlock his identity.
Zeolites used extensively in industry are promising catalysts that turn biomass into transportation fuels, but the activity and stability of this class of materials is challenging to understand and predict. Employing a combination of methods devised at Pacific Northwest National Laboratory and the Swiss Light Source, scientists were able to determine the distribution of aluminum ions in structural variants of zeolites.
Researchers at SLAC National Accelerator Laboratory have developed a laser-timing system that could allow scientists to take snapshots of electrons zipping around atoms and molecules. Taking timing to this new extreme of speed and accuracy at the Linac Coherent Light Source x-ray laser will make it possible to see the formative stages of chemical reactions.
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