From Argonne APS: “High-pressure imaging breakthrough a boon for nanotechnology”

News from Argonne National Laboratory

APRIL 9, 2013
Tona Kunz

“The study of nanoscale material just got much easier, and the design of nanoscale technology could get much more efficient, thanks to an advance in X-ray analysis.

Nanomaterials develop new physical and chemical properties, such as superconductivity and enhanced strength, when exposed to extreme pressure. A better understanding of how and when those changes occur can guide the design of better products that use nanotechnology.

But high-energy X-rays produced by lightsources such as the Advanced Photon Source (APS) at Argonne National Laboratory are the only way to study the in-situ structural changes induced by pressure in nanomaterials, and those studies have lacked precision.

Until now.

Bragg CXDI measurements were performed at 0.8, 1.7, 2.5, 3.2, and 6.4 GPa on the same crystal. The reconstructed images (both top and bottom views) are shown above. From W. Yang et al., Nat. Comm. 4 (2013).

As reported in a Carnegie Institute of Science press release, an international team of scientists using the APS detailed in the April 9 issue of the journal Nature Communications that they devised a way to overcome the distortion caused by sample environments used with the X-rays to improve spatial resolution imaging by two orders of magnitude. This 30-nanometer resolution greatly reduces uncertainties for studies of nanoscale materials. Researchers expect to fine-tune the technique to reach resolutions of a few nanometers in subsequent experiments.

The team, with members from the Carnegie Institution of Washington, the Center for High Pressure Science and Technology Advanced Research (P.R. China), Argonne National Laboratory, University College London (UK), and the Research Complex at Harwell (UK), found that by averaging the patterns of the bent waves—the diffraction patterns—of the same crystal using different sample alignments in the instrumentation, and by using an algorithm developed by researchers at the London Centre for Nanotechnology, they could compensate for the distortion and improve spatial resolution by two orders of magnitude. The new technique is called the “mutual coherent function” method, or MCF.”

See the Argonne article here. See the Argonne APS article here.

Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

The Advanced Photon Source at Argonne National Laboratory is one of five national synchrotron radiation light sources supported by the U.S. Department of Energy’s Office of Science to carry out applied and basic research to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels, provide the foundations for new energy technologies, and support DOE missions in energy, environment, and national security.

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From Argonne APS: "Protein Structure Could Lead to Better Treatments for HIV, Early Aging"

News from Argonne National Laboratory

APRIL 9, 2013
No Writer Credit

“Researchers have determined the molecular structure of a protein whose mutations have been linked to several early aging diseases, and side effects for common human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) medications. This breakthrough could eventually help researchers develop new treatments for these early-aging diseases and redesign AIDS medications to avoid side effects such as diabetes. The research was carried out at the Southeastern Regional Collaborative Access Team(SER-CAT) facility at the U.S. Department of Energy Office of Science’s Advanced Photon Source (APS) at Argonne National Laboratory.

Ribbon diagram of the Ste24p protease.

The researchers from the University of Virginia School of Medicine, the Hauptman-Woodward Medical Research Institute, and the University of Rochester School of Medicine and Dentistry determined the molecular structure of the enzyme Ste24p. Their Membrane Protein Structural Biology Consortium is funded by the National Institutes of Health Protein Structure Initiative, which supports the determination of molecular structures of biomedically important target proteins. Their findings were published March 29 in the journal Science.

Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

The Advanced Photon Source at Argonne National Laboratory is one of five national synchrotron radiation light sources supported by the U.S. Department of Energy’s Office of Science to carry out applied and basic research to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels, provide the foundations for new energy technologies, and support DOE missions in energy, environment, and national security.

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From Argonne APS: “Antibody evolution could guide HIV vaccine development”

News from Argonne National Laboratory

“Observing the evolution of a particular type of antibody in an infected HIV-1 patient has provided insights that will enable vaccination strategies that mimic the actual antibody development within the body. Spearheaded by Duke University, the multi-institution study included analysis from Los Alamos National Laboratory and used high-energy X-rays from the Advanced Photon Source at Argonne National Laboratory.

The evolution of the viral protein (green) from 14 weeks through 100 weeks post-transmission is compared with the maturation of the human antibody.

The kind of antibody studied is called a broadly cross-reactive neutralizing antibody, and details of its generation could provide a blueprint for effective vaccination, according to the study’s authors. In a paper published online in Nature this week titled Co-evolution of a broadly neutralizing HIV-1 antibody and founder virus, the team reported on the isolation, evolution and structure of a broadly neutralizing antibody from an African donor followed from the time of infection.

The observations trace the co-evolution of the virus and antibodies, ultimately leading to the development of a strain of the potent antibodies in this subject, and they could provide insights into strategies to elicit similar antibodies by vaccination.

Patients early in HIV-1 infection have primarily a single “founder” form of the virus that has been strong enough to infect the patient, even though the population in the originating patient is usually far more diverse and contains a wide variety of HIV mutations. Once the founder virus is involved in the new patient’s system, the surrounding environment stimulates the HIV to mutate and form a unique, tailored population of virus that is specific to the individual.

‘Our hope is that a vaccine based on the series of HIV variants that evolved within this subject, that were together capable of stimulating this potent broad antibody response in his natural infection, may enable triggering similar protective antibody responses in vaccines,’ said [Bette] Korber, leader of the Los Alamos team.”

Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

The Advanced Photon Source at Argonne National Laboratory is one of five national synchrotron radiation light sources supported by the U.S. Department of Energy’s Office of Science to carry out applied and basic research to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels, provide the foundations for new energy technologies, and support DOE missions in energy, environment, and national security.

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From INL: “French nuclear designers tap American expertise”

Idaho National Laboratory

March 25, 2013
Nicole Stricker, INL
Angela Y. Hardin, Argonne

“The world’s nuclear experts have reached out to U.S. Department of Energy engineers for help evaluating a new nuclear reactor design that could increase safety margins while reducing waste. The project marked a series of firsts for nuclear engineers on both sides of the Atlantic. They fostered a new collaboration and tapped state-of-the-art analysis tools to evaluate a first-of-a-kind reactor design.

INL nuclear engineer John Bess helped perform INL’s portion of an advanced reactor analysis, which was a collaboration with Argonne National Laboratory and France’s Atomic Energy and Alternative Energies Commission. No image credit.

France’s Atomic Energy and Alternative Energies Commission (CEA) collaborated with nuclear engineers at DOE’s Idaho National Laboratory and Argonne National Laboratory for the project. Its goal: assess safety and performance parameters for a new fast reactor design. The effort used cutting-edge analysis tools, and the findings verified French predictions while highlighting where to focus future efforts.

‘We have tools and data today that we didn’t have 15 years ago,’ said INL Fellow Giuseppe Palmiotti, who led the lab’s contribution. ‘Plus, this enabled young American engineers to evaluate a unique design with a promising outlook.’

Hussein Khalil, director of Argonne’s Nuclear Engineering Division, added, ‘Enhancing safety is a key priority for future-generation reactors, and international collaboration is very beneficial for establishing safety criteria and verifying that new reactor designs meet or exceed these criteria.’”

France’s Advanced Sodium Technological Reactor for Industrial Demonstration (ASTRID) fast reactor design. No image credit

he ASTRID design includes passive safety systems and a fuel design that would naturally slow the fission process if reactor shutdown capability was lost. No image credit.

See the full article here.

In operation since 1949, INL is a science-based, applied engineering national laboratory dedicated to supporting the U.S. Department of Energy’s missions in nuclear and energy research, science, and national defense. INL is operated for the Department of Energy (DOE) by Battelle Energy Alliance (BEA) and partners, each providing unique educational, management, research and scientific assets into a world-class national laboratory.

From Argonne APS: "Shedding Light on Chemistry with a Biological Twist"

News from Argonne National Laboratory

MARCH 14, 2013
David Bradley

“Many of life’s processes rely on light to trigger a chemical change. Photosynthesis, vision, the movement of light-seeking or light-avoiding bacteria, for instance, all exploit photochemistry. Discovering exactly how living things absorb and convert light energy into a form that can change the molecules involved in such processes would not only help scientists understand them but could lead to ways to mimic such processes for more efficient solar energy conversion, for instance. A clearer understanding of how light can drive biological processes has emerged from x-ray diffraction studies carried out on beamlines at the U.S. Department of Energy Office of Science’s Advanced Photon Source (APS) at Argonne, and the European Synchrotron Radiation Facility (ESRF). This work will help science shed a brighter light on some of life’s most critical processes.”

The isomerization of a small molecule caged inside a photoactive protein recorded by time-resolved x-ray crystallography reveals a detailed sequence of events (represented by dominos) composed of a short-lived intermediate (red) whose reaction trajectory bifurcates along bicycle-pedal (left) and hula-twist (right) pathways. No image credit.

See the full article here.

Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

The Advanced Photon Source at Argonne National Laboratory is one of five national synchrotron radiation light sources supported by the U.S. Department of Energy’s Office of Science to carry out applied and basic research to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels, provide the foundations for new energy technologies, and support DOE missions in energy, environment, and national security.

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From Argonne: “Watching a Protein as it Functions”

News from Argonne National Laboratory

MARCH 14, 2013
Mona Mort

“When it comes to understanding how proteins perform their amazing cellular feats, it is often the case that the more one knows the less one realizes they know. For decades, biochemists and biophysicists have worked to reveal the relationship between protein structural complexity and function, only to discover more complexity. One challenging aspect of protein behavior has been the speed with which they change shape and interact with their neighboring biomolecules. Until recently, researchers have relied on a somewhat static approach, using freeze-trapping to capture protein intermediates at various steps along a biochemical pathway. But exciting breakthroughs now allow us to watch proteins changing in real time.

The PYP structure in its ground (pG) state: Arrows point to the pCA C2=C3 double bond and the Ca atoms of key residues. Hydrogen bonds are indicated with dashed blue lines. Arg52 is stabilized in its “closed” state via hydrogen bonds to the protein backbone.No image credit

A research group has developed the necessary infrastructure at the BioCARS 14-ID-B beamline at the U.S. Department of Energy Office of Science’s Advanced Photon Source to watch proteins function in real time on the picosecond time scale. Their work brings us many steps closer to knowing how proteins function, or malfunction when leading to disease.”

See the full article here.

Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

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From Argonne: “Teasing Out the Nature of Structural Instabilities in Ceramic Compounds”

News from Argonne National Laboratory

MARCH 12, 2013
No Writer Credit

“Materials scientists have been for some time preparing artificial ceramic systems that simply do not exist in nature, allowing scientists to engineer particularly interesting and even technologically applicable behaviors. But sometimes nature itself finds ingenious solutions to physical problems that we have not been able to solve.

The simple perovskite structure of EuTiO3 illustrated above shows the essential competing structural instabilities. At the center of the figure is the oxygen cage rotation, and to the right is the central titanium displacement. X-ray diffraction studies showed that, to accommodate the incompatibility of these distortions, they naturally form a long, inter-digitized superstructure (illustrated at far left), which allows them to coexist. Ultimately, this research demonstrates that when both electric and magnetic fields are applied as the europium spins align, the oxygen cage responds, mediating communication between the titanium electric and europium magnetic parameters.

An international team of researchers lead by Argonne National Laboratory utilized high-brightness x-rays from the U.S. Department of Energy Office of Science’s Advanced Photon Source at Argonne National Laboratory, as well as the European Synchrotron Radiation Facility (ESRF), to study the rare-earth magnetic material europium titanate (EuTiO3). Their results were published in the journal Physical Review Letters.

In a magnetic field, the (near) optical properties of EuTiO3 change quite dramatically, presenting hope of a strong magneto-electric material often dreamed of by engineers for use in combining magnetic and charge parameters for many memory, processing, and sensor devices.

Emerging ceramic materials are displaying a tantalizing array of characteristics that could find application in existing and new technologies including magnetic, piezoelectric, ferroelectric, metal insulator transitions, and even superconductivity. Most interesting to physicists is the delicate nature balancing the underlying parameters that drive each quality. If one introduces a different mix of materials, perhaps replacing one element with another or even slightly distorting the structure, then one parameter disappears while another emerges. How all the separate electronic orbits behave and interact with respect to, and with, each other is a fascinating arena for scientists seeking to understand ceramics, a well-known and ancient material family.”

See the full article here.

Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

The Advanced Photon Source at Argonne National Laboratory is one of five national synchrotron radiation light sources supported by the U.S. Department of Energy’s Office of Science to carry out applied and basic research to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels, provide the foundations for new energy technologies, and support DOE missions in energy, environment, and national security.

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From Argonne Lab: “Doubling Estimates of Light Elements in the Earth’s Core”

Argonne National Laboratory

MARCH 1, 2013
Zhu Mao

The inner core of the Earth is the remotest area on the globe, mostly impossible to study directly. It is an area of the planet that experiences both extremely high pressure ranging from 3,300,000 to 3,600,000 times atmospheric pressure, and extremely high temperatures somewhere from 5000 to 6000 K. One way to study this area is by recording how sound waves travel across the interior, matching these profiles to known information about how sound waves travel through candidate iron alloys, and attempting to discern which materials must be present. This method requires an understanding of how sound waves travel through the potential materials present in the core. A team of researchers utilized APS x-rays to develop a new model of how sound waves travel through iron and iron-silicon alloys, showing for the first time that increased temperatures will affect the sound wave profile, and that sound velocity and density correlate in a non-linear way. Their results suggest that the amount of light elements in the inner core could be two times more than estimated in previous studies without considering these effects.

Velocity-density plots of the samples at high pressures and temperatures. The top panel shows the velocity-density plot for hcp-Fe at both 300 K and 700 K. The dashed lines shows the linear fit, while the solid line shows the power law fit, which matches the data more closely. The bottom panel shows the velocity-density relation of both hcp-Fe and the iron-silicon alloy at 300 K.

See the full article here.

Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

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From Argonne Lab: “Breakthrough could lead to drugs that better combat ‘superbugs’ “

News from Argonne National Laboratory

February 28, 2013
Jen Salazar

“In the never-ending battle between antibiotic developers and the bacteria they fight, scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have made a key breakthrough that could allow for the development of new drugs to more effectively combat antibiotic-resistant ‘superbugs’.

NDM-1, present in a number of pathogenic bacteria, including Klebsiella pneumonia and Escherichia coli, is able to defeat many of the world’s most widely used antibiotics, including penicillin derivatives, cephalosporins, monobactams and carbapenems.

An Argonne team led by Youngchang Kim of the Structural Biology Center, in collaboration with researchers from the Midwest Center for Structural Genomics, the University of Texas-Pan American and Texas A&M University, recently determined the structure of NDM-1, a harmful enzyme able to overcome several antibiotics. The team used a combination of X-ray crystallography at Argonne’s Advanced Photon Source (APS), biochemical assays, and computational modeling using resources at two Texas universities.

‘These kinds of enzymes can recognize many different targets,’ said Andrzej Joachimiak, head of Argonne’s Structural Biology Center and the Midwest Center for Structural Genomics.

‘The next step in the research is to look for inhibitors that we can create that would block the functioning of the enzyme,’ Joachimiak said. ‘If we can stop the enzyme from cutting the ring, the antibiotics stand a much better chance of staying effective.”

See the full article here.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

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From Argonne Lab: “Probing Ultrafast Solvation Dynamics with High Repetition-Rate Laser/X-ray Methodologies”

News from Argonne National Laboratory

FEBRUARY 11, 2012
No Writer credit

“The chemical reactivity of molecules in solution critically depends on a complex interplay among intramolecular processes and interactions with the caging solvation shell, which surrounds a solute molecule. Accordingly, the influence of solvation on the reactivity of chemical and biological molecular species has been the subject of increasingly intense research. Ultrafast time-resolved x-ray measurement techniques that combine picosecond lasers and short-pulse x-rays in laser pump/x-ray probe experiments are powerful tools for studying this interplay in photo-active molecular systems.

X-ray absorption, emission and diffuse scattering data acquired in a single experiment using MHz pump-probe repetition rates. By including x-ray diffuse scattering, the researchers could detect an ultrafast change in the solvent density (lower right, blue points) upon photo-excitation of the solute.

Such time-resolved laser pump/x-ray probe experiments have been carried out at synchrotrons for several years; however, few have been able to make use of the full x-ray flux available, often because of the low (kHz) repetition rate of amplified laser systems. Thanks to implementation of a high-repetition-rate (54 kHz–6.5 MHz), high-power (>10 W) laser system at the X-ray Science Division 7-ID-D beamline at the Advanced Photon Source (APS), it has become possible to fully match the repetition rate of the laser to the 6.5-MHz rate of the x-rays, and thus to more efficiently use the flux provided by the APS.

This has enabled laser pump/x-ray probe measurements incorporating simultaneous x-ray spectroscopy and x-ray scattering techniques to study light-induced intramolecular processes and solvent interactions in challenging molecular systems. It is accomplished by simultaneous, time-resolved utilization of several complementary analytical techniques that all take advantage of the thousand-fold increase in useful x-ray flux provided by the MHz scheme.

Researchers from the Technical University of Denmark, the Hungarian Academy of Sciences, the European XFEL at DESY (Germany), Argonne National Laboratory, the University of Copenhagen, SLAC National Accelerator Laboratory, and Lund University (Sweden) designed such an experiment for a highly detailed study of the photoinduced low-spin (LS) to high-spin (HS) conversion of iron(II)-tris(2,2′-bipyridine), [Fe(bpy)3]2+, in aqueous solution, to provide information on the interplay between intramolecular dynamics and the caging solvent response on a 100-ps time scale.

See the full article here.

Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

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