High-temperature superconductors (HTSCs) operate in mysterious ways, but scientists are starting to understand their peculiarities by using a state-of-the-art spectroscopy system at SSRL. One of the biggest mysteries is how a material that starts as an insulator-which does not conduct electricity-can become a high-temperature superconductor after being doped with electric carriers. Researchers Kyle Shen and Donghui Lu (both SSRL), working in Zhi-xun Shen's group at SSRL and Stanford, looked at the evolution from insulator to superconductor by studying an HTSC material at different doping concentrations.
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.
March 2005
Angle-resolved photoelectron spectroscopy
BL5-4
February 2005
The lysosome is the "digestive system" of an animal cell. Molecules taken up from the outside are sent to the lysosome to be broken up into a form that can be safely used by the rest of the cell. A network of membrane vesicles called the endocytic pathway moves cargo destined for the lysosome from the surface of the cell. One of the last steps before the cargo reaches the cell is the pinching-off of small vesicles into the center of a big vesicle.
Macromolecular Crystallography
BL9-2
December 2004
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
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
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
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
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
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
September 2004
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
August 2004
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
Pages
