One of the strangest consequences of quantum mechanics is the seemingly instantaneous communication of subatomic particles over long distances. Known as quantum entanglement, pairs or groups of particles can become linked so that any changes made to one will cause the others to respond quicker than the time it takes for light to travel between them.
Approximately 1,600 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 and to add your most recent publications to this collection.
While we continue to refine our science highlights content you may access older science summaries that date between 04/2001 to 06/2010 by visiting http://www-ssrl.slac.stanford.edu/science/sciencehighlights.html. We will be offering science summaries that date from 06/2012 to the present soon.
Scientists have recently identified a family of human antibodies that can take out an unprecedented number of different types of flu viruses, including H5N1 'bird flu' and the 1918 H1N1 'Spanish flu', which killed millions around the world during World War I, as well as seasonal flu. Using SSRL's Beam Line 9-2, Dr. Robert Liddington from the Burnham Institute for Medical Research led a team of scientists that determined the crystal structure of one such antibody, F10, in complex with the hemagglutinin H5 to unveil the molecular mechanism of virus neutralization. Results were published online 22 February 2009 in the journal Nature Structural and Molecular Biology.
Organomercury is a well-known poison, and the potential for exposure worries many communities worldwide. Developing embryos are especially susceptible to mercury poisoning, which can result in serious birth defects. Despite the awareness of mercury's adverse health affects, little is known about the mechanisms for mercury toxicity.
Currently, more than 1/6th of the people in the world lack safe and clean water. Population shifts, global warming and many other global changes will make this shortage even more critical in the coming years. Solutions to this problem lie in the development of new, energy-efficient means of purifying water. One of the traditional purification technologies—called membrane-based reverse osmosis—is very energy intensive, and this is spurring a flurry of activities into creating new, energy-efficient materials. Among the most promising of these materials are carbon nanotubes. A related material, activated carbon—basically carbon treated at extreme temperatures to achieve a high degree of microporosity and functionality-has been used for a century or more to filter water, and soak up unwanted compounds. However, the precise arrangements of the atoms that give rise to these purifying properties have mostly remained a mystery.
Phytoplankton are microorganisms that live in the ocean surface waters and are important because they act as lungs for the planet, consuming carbon dioxide and producing oxygen. Phytoplankton account for an astounding 50% of the total biological uptake (or sequestration) of carbon dioxide annually. Understanding the factors that affect the growth of phytoplankton, is therefore of particular importance for this carbon sequestration, since the amount of released carbon dioxide continues to increase world-wide.
DNA is softer and stretchier than previously believed, at least on the short length scales of up to 20 base pairs. This finding is the result of a recent study conducted in part at SSRL's biological small-angle x-ray scattering Beam Line 4-2 by a team of researchers from Stanford University. The results were published in the October 17 edition of the journal Science.
Using macromolecular crystallography techniques, the team solved the structure of a protein on the Ebolavirus's surface, called glycoprotein GP, in complex with a rare antibody identified in a human survivor. The glycoprotein-antibody complex proved especially challenging to crystallize and subsequently, to yield well-diffracting crystals. The team grew ~50,000 crystal samples and screened 800 of the largest, using in part the highly-automated robotics hardware and software at the SSRL beam lines, before finding a sample that would diffract to 3.4 Angstroms.
Scientists are one step closer to understanding a piece of the machinery involved in DNA transcription and repair, thanks to work done in part at the SSRL macromolecular crystallography Beam Line 11-1. The team, led by The Scripps Research Institute researcher John Tainer, and colleagues worked out the structure of an important enzyme call XPD, a member of the helicase family of enzymes, found in all living organisms. The results were published in the May 2008 edition of the journal Cell.
Iron plays an integral role in many biochemical processes essential for life. However excess iron leads to the production of highly reactive hydroxyl radicals by Fenton chemistry (1). These free radicals are deleterious to cells as they react indiscriminately with proteins, DNA and lipids. Hence, iron homeostasis is a highly regulated process and is critical to human health (2). Disorders in iron metabolism, are however, surprisingly common. Iron deficiency affects more than one billion people worldwide (3,4), while iron overload disorders (hereditary hemochromatosis) are among the most frequent single gene disorders in humans. For example occurrence of disease associated allele, HFEC282Y, is as high as 10% in individuals of Northern European descent (5).
The recent discovery of superconductivity in iron-based layered compounds known as iron oxypnictides has renewed interest in high-temperature superconductivity. Now, SLAC and Stanford researchers, using SSRL's angle resolved photoemission spectrometer at Beam Line 5-4, have furthered the quest to understand this iron-based compound. In a recent paper published in Nature, SSRL scientist Donghui Lu, with colleagues at SSRL and Stanford, reported on the mechanism behind the superconductivity of a lanthanum-oxygen-iron-phosphorus (LaOFeP) compound, one of the new iron-based superconducting materials.




![Figure 1. Bromine EXAFS signal (A) and the R-function (B) for the 0.5M rubidium bromide reference solution. Corresponding bromine EXAFS (C) and R-function (D) for the activated carbon sample, along with model fits (in red) derived from FEFF8.[3] The fit was performed over a k-space from 3 to 12.7 Å-1 (R from 1 to 4.7 Å) for the solution sample and the AC6 sample. The difference between the peak positions and the true Br coordination distances can be resolved by a phase correction term. Figure 1.](http://www-ssrl.slac.stanford.edu/content/sites/default/files/styles/custom-160/public/images/science/highlights/2009/carbon-nanotubes_fig1.jpg?itok=YdhFvFMs)
![Figure 1. Top: Iron is thought to limit phytoplankton in much of the world's oceans. Bottom: Structure of the iron-siderophore complex ferrioxamine B [Fe(III)HDFOB+]. Image courtesy of Andrzej Jarzecki, Brooklyn College, the City University of New York. Figure 1.](http://www-ssrl.slac.stanford.edu/content/sites/default/files/styles/custom-160/public/images/science/highlights/2009/mn-marine-cycle_fig1.jpg?itok=c52Ct986)
![Figure 1: [A] Scattering intensity as a function of scattering angle for the 20 base-pair double-labeled (blue), single-labeled (red, magenta; indistinguishable), and unlabeled (cyan) DNA duplexes. The intensity of the double-labeled sample has been scaled by a factor of 1/2 to aid visual comparison. The pattern of scattering interference between the two nanocrystal labels (black) is obtained by summing the intensities of the double-labeled and unlabeled samples, then subtracting the intensities of the two single-labeled samples. [B] Transformation of the nanocrystal scattering interference pattern into a weighted sum of sinusoidal basis functions (corresponding to different interprobe distances) yields the probability distribution for nanocrystal center-of-mass separation. Figure 1.](http://www-ssrl.slac.stanford.edu/content/sites/default/files/styles/custom-160/public/images/science/highlights/2008/molecular_ruler_fig1.jpg?itok=Ft-7pXFi)







