The ability to design and control the activities of transition metal catalysts, which are scarce in nature and thus expensive, has been of great importance to the development of economical industrial and energy-saving processes. Over the years several methods have been suggested, especially for processes using platinum, which is the most active metal catalyst for many important reactions, including the reduction of oxygen in fuel cells.
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.
July 2012
BL13-2
June 2012
Changing the electronic structure of a metal in order to “tune” its affinity to catalytic reaction intermediates is a key element in catalyst design. Tailor-made catalysts with a carefully adjusted ratio of two or more different alloy components are particularly needed in fuel cells, which could efficiently power electric vehicles – without the range limitations of current batteries. Both convert chemically stored energy into electricity, but in batteries this storage is limited to the electrode materials themselves, while fuel cells draw hydrogen or methanol from a tank and oxygen from air.
X-ray Absorption Spectroscopy
BL6-2, BL11-2
June 2012
Dramatic improvements in energy storage devices are essential to meet the increasing need to move away from fossil fuels and toward clean, renewable energy. Rechargeable lithium-sulfur (Li-S) batteries hold great potential for high-performance energy storage systems because they have a high theoretical specific energy, low cost, and are eco-friendly; but a better understanding of how the battery functions is required to design improvements for higher efficiency and capacity.
X-ray diffraction
BL6-2c, BL11-3
June 2012
Prostate cancer, the most common cancer in men, is often a localized, slow-growing cancer, which aids treatment and improves survival rates. However, highly aggressive, metastatic forms of the cancer occur frequently enough to make it the No. 2 cause of death in U.S. men. Part of the reason for this high mortality rate is the lack of effective drugs to fight these more aggressive cancers.
Macromolecular Crystallography
BL9-2
May 2012
The continuous advancement of X-ray spectroscopic techniques allows us to probe the structure of biological machineries for smaller samples in more dilute concentrations and thus to ask tough scientific questions about problems that have not been possible in the past. Careful biochemical preparation and systematic analytical characterization resulted in galactose oxidase samples that could be interrogated by X-rays. This metalloenzyme contains a copper at its active site that is coordinated to a cross-linked tyrosine and cysteine ligand, which both are essential to convert alcohols and sugars to their oxidized aldehyde forms by oxygen molecule. The remarkable feature of this reaction that it is selective and does not results in formation of carboxylates (a form of vinegar).
X-ray Absorption Spectroscopy
BL4-3, BL6-2
May 2012
Nearly 400 years ago, the Swedish warship Vasa sank to its watery grave. In 287 BCE, a Roman warship with its bronze naval ram sank after battle to the bottom of the sea. And in 1545, the flagship of Henry VIII’s navy, the Mary Rose, sank outside of Portsmouth while maneuvering to engage the French fleet. Using SSRL Beam Line 4-3, a team of SSRL and University of Palermo researchers measured x-ray spectra of the sulfur inside wooden sections of the Roman ram, revealing the kinds of sulfur hidden within.
X-ray Absorption Spectroscopy
BL4-3
April 2012
However, the superconducting gap distributions in iron-based superconductors do not fall neatly into either of these two symmetries. Nodeless gap distributions, such as are associated with s-wave pairing symmetry have been directly observed in some members of the iron-based family of high-temperature superconductors, and the signatures of nodal superconducting gaps have been reported in others.
Angle-resolved photoelectron spectroscopy
BL5-4
April 2012
Cytokines are central to the innate immune system. Type I interferons (IFNs) are a kind of cytokine signaling protein that is important for cellular communication, regulating diverse cellular processes. Showing surprising economy, just one receptor is responsible for binding a variety of IFNs, each with differing functions.
Macromolecular Crystallography
BL9-1, BL9-2, BL11-1
April 2012
In order for our eyes to see in both intense and low light conditions, molecular mechanisms allow for light and dark adaptation. The G-protein transducin is responsible for transducing signal from the photon receptor protein rhodopsin in rod and cone photoreceptors of our retina. Transducin is composed of three polypeptides, α, β and γ. The α subunit contains the GTP binding site. While waiting for a signal from rhodopsin, transducin is bound to the outer segment of the neuron. During exposure to normal daylight, transducin becomes displaced and migrates to another part of the cell: the photoreceptor is adapting to light. In darkness or very dim light, transducin will return to its “home” membrane.
Macromolecular Crystallography
March 2012
Strategies to combat HIV require structural knowledge of how antibodies recognize HIV envelope proteins and how they are used by the immune system to eliminate viruses and virally-infected cells. A few years after infection, some HIV-infected patients develop broadly neutralizing antibodies (bNAbs), which neutralize across many HIV strains and confer protection against simian immunodeficiency virus (SIV) infection in non-human primates when delivered by passive immunization (i.e. purified Abs were injected). Despite the fact that HIV-infected individuals can produce bNAbs, a vaccine that can elicit such Abs has yet to be identified or designed.
Macromolecular Crystallography
BL12-2
Pages
