While scientists recognize that oxygen-free soil stores large amounts of carbon, knowledge about the processes that protect and preserve carbon-rich molecules in these environments is lacking. In oxygen-rich soil, microbes break down organic molecules through aerobic respiration, allowing carbon to escape the ground as carbon dioxide gas.
Approximately 1,700 scientists visit SSRL annually to conduct experiments in broad disciplines including life sciences, materials, environmental science, and accelerator physics. Science highlights featured here and in our monthly newsletter, Headlines, increase the visibility of user science as well as the important contribution of SSRL in facilitating basic and applied scientific research. Many of these scientific highlights have been included in reports to funding agencies and have been picked up by other media. Users are strongly encouraged to contact us when exciting results are about to be published. We can work with users and the SLAC Office of Communication to develop the story and to communicate user research findings to a much broader audience. Visit SSRL Publications for a list of the hundreds of SSRL-related scientific papers published annually. Contact us to add your most recent publications to this collection.
May 2017
X-ray Absorption Spectroscopy
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April 2017
Famous for their role in the process of aging, telomeres are the regions of repetitive DNA sequences at the ends of our chromosomes. These repeats are critical for preserving the structure and function of our DNA in concert with numerous cellular factors. One factor responsible for the regulation and maintenance of telomere length is the shelterin complex, composed of six proteins including one called POT1.
Macromolecular Crystallography
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April 2017
An intracerebral hemorrhage (ICH) stroke occurs when a blood vessel bursts inside the brain and blood leaks into brain tissue. Secondary damage is caused by hemoglobin iron making free radicals that cause oxidative damage to brain cells. While prompt rehabilitative therapies have been shown to limit damage, the mechanism for this is unknown.
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March 2017
Coal-ash spills in Tennessee and North Carolina rivers have prompted concerns that toxic trace elements like arsenic could be concentrated in the food web to potentially affect humans. At the base of these freshwater food webs are periphyton biofilms, which contain a complex ecosystem of micro-organisms including bacteria, fungi, diatoms, and algae. Such biofilms can concentrate trace elements hundreds to thousands of times. To investigate whether arsenic concentrated in biofilms is propagated up the food chain, a team of scientists has studied the bioavailability of arsenic to organisms that feed on the periphyton biofilms.
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February 2017
Microtubules (MTs) are sub-cellular structures made of the protein tubulin. They have important roles in moving organelles around the cell and in chromosome segregation before cell division. MTs can exist in two states, either a dynamic state of growing and shrinking MTs or a stable state. MTs can also form complex bundles that can be found in neuronal axons. The neuronal protein Tau helps facilitate this process and has been implicated in some neurodegenerative disorders like Alzheimer’s disease. Yet Tau’s exact role in MT formation and bundling is unclear: different experiments (both in vivo and cell free) have shown Tau to mediate either attractive or repulsive forces between MTs.
Biological Small-angle X-ray Scattering (BioSAXS)
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January 2017
The presence of the receptor tyrosine kinase Axl on tumor cells is correlated with disease severity and thus is an important oncology target. Developing inhibitors to Axl has been met with limited success due to the tight affinity with which Axl binds its ligand, growth arrest-specific 6 (Gas6). Researchers have engineered a soluble “receptor decoy,” called MYD1, based on Axl’s ligand-binding domain, that binds Gas6 even more tightly than Axl does.
Macromolecular Crystallography
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January 2017
Lithium ion batteries are critical to many portable consumer electric devices, but they still do not have a high enough energy storage capacity for some applications, such as electric cars. Researchers and engineers are working to improve these batteries by changing the materials used. Using silicon as the anode has been promising, showing up to 10-fold higher capacity than the currently used graphite-based anode material. However, commercialization is still limited because the silicon expands and contracts dramatically when charged and discharged, causing cracking and pulverization that limit the battery lifetime.
X-ray reflectivity
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December 2016
Over the past three years a team of researchers has worked to understand the thermodynamic transitions in the antiferromagnetic ferroelectric BiFeO3 with La substitutions in relation to a new strategy for finding the ultimate magnetoelectric single phase material. The researchers made the striking finding that structural, ferroelectric, and magnetic phases evolve due to strong spin-lattice coupling, thereby producing a multiferroic triple phase point where three competing multiferroic phases merge.
Scanning transmission x-ray microscopy
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October 2016
Rare earth magnetic materials have many applications, such as MRI scanners, Maglev trains, and electric vehicles. Scientists are researching improvements to these magnets through optimizing the component materials. Taking a different approach, a team of scientists have studied the effects of nano-scale heterogeneity in the chemistry and structure of Nd2Fe14B, a very strong and widely-used rare earth magnet.
X-ray microscopy
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October 2016
Researchers are evaluating the use of organic semi-conductive polymers instead of inorganic semiconductors for use in solar cells. Polymer semiconductors are more flexible and more easily applied, which could allow for more uses and lower production costs. Unfortunately, solar cell devices made of these organic materials tend to have less power conversion efficiency, largely due to the way the donor and acceptor molecules are arranged in the bulk heterojunction (BHJ) structures.
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