SSRL Science Highlights Archive

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.

SCIENCE HIGHLIGHT BANNER IMAGES

December 2004
Mark A. Breidenbach, Axel T. Brunger
Figure 1.

The Botox® face lifts and botulism disease are both caused by a neurotoxin from the bacterium Clostridium botulinum. The toxin, often described as the most lethal substance known, is a member of the clostridal neurotoxins (CNTs) group, which block muscle contractions. When injected into someone's face, the effect is a lessening of wrinkles. When ingested, the toxin paralyzes muscles, including those of the internal organs, causing sickness and death. The toxin is also used in medicine for conditions such as uncontrolled blinking, lazy eye, and involuntary muscle contractions.

Macromolecular Crystallography
BL9-2
December 2004
J. Lüning, W. F. Schlotter, J. Stöhr
Figure 1.

Researchers at the Stanford Synchrotron Radiation Laboratory (SSRL) and the German laboratory BESSY have crafted a versatile and stunningly effective technique to take x-ray images of tiny variations and lightning-quick changes in materials a thousand times smaller than the thickness of a strand of hair. Their work merits the cover of the December 16 issue of Nature. Researchers Jan Lüning of SSRL, Stefan Eisebitt of BESSY and their colleagues demonstrated the first direct imaging technique - lensless x-ray holography - that will work at the world's first x-ray free electron laser, the Linac Coherent Light Source (LCLS), slated to open at SLAC in 2009. Lensless imaging opens the door for "single shot" pictures at LCLS using just one pulse of x-ray light to capture a clear picture of ultra-fast action occurring on ultra-small length scale.

November 2004
Myriam Perez De la Rosa, Gilles Berhault, Apurva Mehta, Russell R. Chianelli
Figure 1.

As oil prices rise, so will the market for cheaper forms of petroleum-based fuels. Cheaper petroleum contains more impurities, which will aggravate environmental problems, like heavier air pollution and acid rain. Purifying the fuel will alleviate the environmental harm. Sulfur impurities can be removed by treatment with catalytic materials such as Molybdenum disulfide (MoS2).

BL2-1
October 2004
Wayne W. Lukens, David K. Shuh, Norman C. Schroeder, Kenneth R. Ashley
Figure 1.

The Hanford nuclear waste site in southeastern Washington State is one of the most contaminated sites in the DOE complex. It stores millions of gallons of radioactive waste from the nation's nuclear weapons programs. High-level radioactive waste is leaking from about a third of Hanford's underground tanks.

BL4-1, BL11-2
October 2004
Eugenio Santelli, Laurie A. Bankston, Stephen H. Leppla, Robert C. Liddington
Figure 1.

X-ray images have revealed how anthrax hijacks important cell machinery to enter and destroy human cells. Researchers from The Burnham Institute and the National Institute of Allergy and Infectious Diseases discovered the structure of an anthrax toxin bound with a cell receptor using data taken at SSRL. The clearer picture of how anthrax works brings researchers closer to the development of a therapy against anthrax infection as well as a new cancer therapeutic.

Macromolecular Crystallography
BL9-2
September 2004
Douglas S. Daniels, Tammy T. Woo, Kieu X. Luu, David M. Noll, Neil D. Clarke, Anthony E. Pegg, John A. Tainer
Figure 1.

Error-free DNA replication depends on the maintenance of the correct chemical structure of each component base. Bases with altered structures may mispair during the replication process, causing mutations. One common chemical alteration is the addition of an alkyl group to guanine, causing mispairing to thiamine during replication.

Macromolecular Crystallography
BL9-1
September 2004
Elitza I. Tocheva, Michael E. P. Murphy
Figure 1.

Nitric oxide (NO) is a small but powerful biologically active molecule that can protect or destroy cells. The bacterial enzyme that creates NO can, however, also turn nitrogen fertilizers into ozone-depleting NO and nitrous oxide, a greenhouse gas. Researchers at the University of British Columbia now have a better understanding of how that enzyme, nitrite reductase (NiR), works. Elitza Tocheva and Michael Murphy used SSRL's macromolecular crystallography facilities to study difficult-to-prepare crystal complexes of NiR bound to NO or to nitrite (which NiR turns into NO).

Macromolecular Crystallography
BL7-1
August 2004
Michael T. Green, John H. Dawson, Harry B. Gray
Figure 1. The rebound mechanism of cytochrome P450.

Chloroperoxidase is one of a large class of heme proteins that play important roles in a number of physiological processes, including xenobiotic metabolism, neurological development, blood pressure control, and immune defense. These heme protein systems all have the ability to oxygenate saturated hydrocarbons under ambient conditions, a process which is chemically quite challenging, and hence is also of industrial importance.

BL7-3
August 2004
James Stevens, Ian A. Wilson
Figure 1. Ribbon representation of the hemagglutinin HA0 trimer from the 1918 influenza virus.

Researchers have literally unearthed clues as to why the 1918 influenza pandemic was so deadly. The 1918 influenza pandemic ranks as the largest and most destructive outbreak of an infectious disease, killing 20 to 40 million people worldwide. Using fragments of the flu genome from Alaskan victims preserved by permafrost and army autopsy tissues, James Stevens and Ian Wilson of the Scripps Research Institute in La Jolla, California and their collaborators have assembled genes from the 1918 flu virus.

Macromolecular Crystallography
BL9-2
July 2004
Anneli Munkholm (Lumileds Lighting), Sean Brennan (SSRL)
Figure 1.

New evidence is overturning the assumption that the thermal oxide grown on single crystal silicon is completely amorphous. SSRL researchers Anneli Munkholm (now at Lumileds Lighting) and Sean Brennan recently published work in Physical Review Letters showing that there is residual order within the oxide. The thermal oxide film on silicon has been studied extensively for decades because these oxides form the basis of most of the integrated circuits used in modern electronics. The new results have implications for theoretical models of the oxidation process.

X-ray scattering

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