The 3D structure of bone is critical for maintaining strength. Skeletal diseases such as osteoporosis and environmental conditions such as weightlessness, radiation, and vitamin D deficiency can affect bone structure. Understanding the 3D structure of bone is critical to understanding how these conditions affect bone's form and function.
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.
June 2010
Scanning transmission x-ray microscopy
BL6-2
June 2010
HIV protease is a common and critical drug target for combating HIV infection and AIDS. As HIV develops resistance to anti-viral drugs, new therapies are required. Since most of the virus's mutations that confer drug resistance cluster in the active site of the protease, scientists are interested in molecules that may bind other places on the enzyme. Computer simulations aid the design of drugs and fragments, which are smaller than typical drugs, to bind the enzyme's surface in a way that compliments the activity of traditional active-site binding drugs.
Macromolecular Crystallography
BL9-2, BL11-1
May 2010
Archaeopteryx, the half-reptilian, half-avian creature that lived 150 million years ago is famous as the fossil record's link between dinosaurs and birds. The discovery of the firstArchaeopteryx fossil, which coincided with the publication of Charles Darwin's On the Origin of Species, provided strong evidence of the theory of evolution. Because Archaeopteryxfossils are important and rare, no samples have been taken for standard chemical analysis, which is a destructive process.
BL6-2
May 2010
An unusual property of the last year's H1N1 "swine flu" virus pandemic is that it disproportionately affected the young. People over the age of around 65 showed much less vulnerability than to more typical flu strains, suggesting that they might have been exposed to a similar virus over three decades ago. Another atypical property of the 2009 H1N1 strain is that its hemagglutinin (HA) subunit is the same subtype as the regular seasonal strains, whereas most pandemics are caused by viruses with novel HA domains.
Macromolecular Crystallography
BL9-2
May 2010
Cells need copper to function, but too much copper can be toxic, leading to liver damage and neurological problems, as happens in disorders such as Wilson disease. The inorganic small molecule tetrathiomolybdate (TM), assumed to be a copper chelator, is commonly used to treat Wilson disease. TM may also be an effective treatment of some cancers by starving the cancer cells of the copper they need to grow. Despite its common use, its molecular mechanism was unknown.
X-ray Absorption Spectroscopy
BL9-3
April 2010
The potential for using biological enzymes to make hydrogen to use as a renewable energy source is a hot topic, but little is known about how these complex enzymes assemble and work. The [FeFe]-hydrogenase enzyme binds iron and sulfur ions to catalyze the reversible production of hydrogen ions from protons and electrons. The enzyme's active site, termed the H-cluster, uses a complex Fe-S cluster comprised of a [4Fe-4S] subcluster and a 2Fe subcluster to catalyze the reaction.
Macromolecular Crystallography
BL9-1, BL9-2
April 2010
Superconductivity is a hot topic in physics for good reason. With an electrical resistance of zero, superconductors transport electrical current with no loss of energy. Unfortunately, scientists have only found materials to be superconducting at very low temperatures, much too low for widespread use. In the 1980s, scientists discovered a class of "high-temperature" superconductors that can be used at the temperature of liquid nitrogen (~-200°C).
Angle-resolved photoelectron spectroscopy
BL5-4
April 2010
Hydrogen fuel cells are a green alternative to fossil fuels for powering vehicles, since the byproduct of fuel cell energy production is simply water. A problem with using fuel cells is their high cost, largely due to the use of the expensive element platinum in their design. The platinum is used at the cathode of the fuel cell, where it catalyzes the reduction of oxygen molecules into oxygen atoms. It is a good choice for this role because it binds the reactant well, breaks the O-O bond efficiently, and does not bind too tightly to the products.
BL2-1, BL4-2, BL13-2
March 2010
The advent of photosynthesis gave life forms a new way to capture energy from the sun. The by-product of the success of photosynthesis, an abundance of dioxygen (O2) in our atmosphere allowed aerobic creatures, including humans, to evolve and prosper. This process transformed the history of life on Earth. The oxidation of water to O2 is catalyzed by the oxygen-evolving complex (Mn4OxCa cluster) in the membrane protein, photosystem II (PSII).
X-ray emission spectroscopy
BL6-2
March 2010
UC Irvine researchers have unveiled the mystery behind one of the deadliest toxins that causes liver cancer. Aflatoxins are common contaminants of foods such as nuts and grains, which make up the staple diets of many developing countries. These toxins are produced by moldy fungi during food production, and are considered by the FDA to be an unavoidable food contaminant. Aflatoxin molecules are characterized by the presence of multiple aromatic rings. Chronic ingestion of aflatoxin B1 leads to liver tumors that are a major cause of death in Asia, Africa, and Central America. This toxin wreaks havoc of p53, an important gene in our body that prevents cancer. Without the protective effect of p53, then, aflatoxin further compromises immunity, interferes with our body metabolism, and causes severe malnutrition. It is urgently important to find inexpensive strategies that help protect the world population from aflatoxin food contamination.
Macromolecular Crystallography
BL9-2
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