A timely solution for the photosynthetic oxygen evolving clock

XFEL Hub collaboration reveals the intermediates of the photosynthetic water oxidation clock

A large international collaborative effort aided by the XFEL Hub at Diamond Light Source has generated the most detailed time-resolved studies to date of a key protein involved in photosynthesis. The pioneering work, recently published in Nature, shows how photosystem II harnesses light energy to produce oxygen – insights that could direct a next generation of photovoltaic cells. 
>Read more on the Diamond Light Source website

Image: this figure is issued from a video you can watch here.

Saving Rembrandt for future generations

New research on beamline I18 at Diamond Light Source investigates preservation techniques for Old Master paintings.

The surface of many Old Master paintings has been affected by the appearance of whitish lead-rich deposits, which are often difficult to fully characterise, thereby hindering conservation. Painted in 1663, Rembrandt’s Homer is an incredibly valuable and much-loved painting. Like many Old Masters it has a long and eventful past, which has taken its toll on the painting’s chemistry. The test of time and environmental factors, combined with the painting’s history, caused a barely visible, whitish crust to form on the surface of the painting. This crust indicates that chemical reactions are occurring which could potentially pose as risk for Homer and other old paintings if not kept in stable museum conditions.
A paper in ChemComm (Royal Society of Chemistry) has been published by a team of conservation scientists from the Mauritshuis in the Hague and the Rijksmuseum in Amsterdam, University of Amsterdam and scientists from Finden Ltd, UCL and Diamond Light Source, the UK’s National Synchrotron. Called “Unravelling the spatial dependency of the complex solid-state chemistry of Pb in a paint micro-sample from Rembrandt’s Homer using XRD-CT,” this paper is particularly timely given the celebrations occurring in 2019 to mark 350 years since the death of Rembrandt and the Dutch Golden Age. A paint micro-sample from Rembrandt’s Homer was imaged using X-ray Diffraction Computed Tomography (XRD-CT) in order to understand the evolving solid-state Pb chemistry from the painting surface and beneath.

>Read more on the Diamond Light Source website

Image: Stephen Price, Lead author from Diamond Light Source and Finden Ltd.

A series of stories celebrating the periodic table’s 150th anniversary

The ESRF is celebrating the International Year of the Periodic Table, because its elements are omnipresent in the research done at the facility. We will publish a series of stories on different elements during the coming weeks. The first series is about the fascinating elements at the bottom of the periodic table.

See the series start here on the ESRF website

Image: Kristina Kvashnina in front of the periodic table. She is from the Helmoltz-Zentrum Dresden-Rossendorf (HZDR) but based at the Rossendorf Beamline (BM20) of ESRF in Grenoble.
Credits: Moulyneux

Discovery may improve cystic fibrosis treatment

A University of Saskatchewan medical research team has made a groundbreaking finding with potential to lead to more effective, longer-lasting and better-tolerated treatments for cystic fibrosis (CF).

“Though we’re still at an early stage for developing new treatments, this is a major discovery of considerable potential relevance to CF patients,” said Dr. Juan Ianowski (PhD), a physiologist at the USask College of Medicine and senior author of a paper on the finding published today in the online Nature Research journal Scientific Reports.
For over 20 years, doctors have treated CF patients with an inhaled concentrated salt solution called hypertonic saline to increase the volume of airway surface liquid (ASL)—a microscopically thin liquid lining that helps remove infected secretions from the clogged chest of a CF patient. The scientific consensus has been that an osmotic reaction drawing water from the blood was responsible for the beneficial increase in ASL from this saline treatment.
But by using synchrotron imaging at the Canadian Light Source (CLS), the national research facility at USask, the nine-member team has concluded that scientists have not completely understood the body’s reaction to the saline treatment.
>Read more on the Canadian Light Source website

Image: Dr. Julian Tam (MD) and Dr. Juan Ianowski (PhD) are researchers with the university’s Respiratory Research Centre.

Platinum forms nano-bubbles

Technologically important noble metal oxidises more readily than expected.

Platinum, a noble metal, is oxidised more quickly than expected under conditions that are technologically relevant. This has emerged from a study jointly conducted by the DESY NanoLab and the Vienna University of Technology. Devices that contain platinum, such as the catalytic converters used to reduce exhaust emissions in cars, can suffer a loss in efficacy as a result of this reaction. The team around principal author Thomas Keller, from DESY and the University of Hamburg, is presenting its findings in the journal Solid State Ionics. The result is also a topic at the users’ meeting of DESY’s X-ray light sources with more than 1000 participants currently taking place in Hamburg.
“Platinum is an extremely important material in technological terms,” says Keller. “The conditions under which platinum undergoes oxidation have not yet been fully established. Examining those conditions is important for a large number of applications.”
The scientists studied a thin layer of platinum which had been applied to an yttria-stabilised zirconia crystal (YSZ crystal), the same combination that is used in the lambda sensor of automotive exhaust emission systems. The YSZ crystal is a so-called ion conductor, meaning that it conducts electrically charged atoms (ions), in this case oxygen ions. The vapour-deposited layer of platinum serves as an electrode. The lambda sensor measures the oxygen content of the exhaust fumes in the car and converts this into an electrical signal which in turn controls the combustion process electronically to minimize toxic exhausts.

>Read more on the DESY (PETRA III) website

Image: Electron microscope view into the interior of a platinum bubble. The cross-section was exposed with a focused ion beam. Below the hollow Pt bubble the angular YSZ crystal can be seen.
Credit: DESY, Satishkumar Kulkarni

Award for a pioneer in synchrotron techniques and tools

Zahid Hussain is honored with the Secretary’s Distinguished Service Award during a surprise ceremony.

Zahid Hussain, a longtime scientist at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), has always been more focused on achievements than accolades, though his lists run long in both categories.

His fingerprints are on many of the instruments and scientific milestones at Berkeley Lab’s Advanced Light Source (ALS), which produces many types of light, from infrared to X-rays, for a range of experiments carried out by visiting scientists from around the world. He has pioneered soft X-ray techniques and instrumentation at the ALS that have been widely adopted by the global scientific community.

>Read more on the Advanced Light Source (ALS) at Berkeley Lab

Towards upscaling the production of graphene nanoribbons for electronics

Two-dimensional sheets of graphene in the form of ribbons a few tens of nanometers across have unique properties that are highly interesting for use in future electronics.

Researchers have now for the first time fully characterised nanoribbons grown in both the two possible configurations on the same wafer with a clear route towards upscaling the production.
Graphene in the form of nanoribbons show so called ballistic transport, which means that the material does not heat up when a current flow through it. This opens up an interesting path towards high speed, low power nanoelectronics. The nanoribbon form may also let graphene behave more like a semiconductor, which is the type of material found in transistors and diodes. The properties of graphene nanoribbons are closely related to the precise structure of the edges of the ribbon. Also, the symmetry of the graphene structure lets the edges take two different configurations, so called zigzag and armchair, depending on the direction of the long respective short edge of the ribbon.

See some video interviews and the entire article on the MAX IV website

Intermittent plasticity in individual grains

A study using high energy x-ray diffraction.

Understanding the behavior of metals undergoing deformation is critical to design for fuel efficiency, performance and safety/crashworthiness. Traditional engineering analysis treats metal deformation as a smooth motion, like a fluid, when in reality the flow is intermittent at finer length scales. Use of a new detector enabled the study of these intermittent bursts of deformation at the scale of individual crystals in a loaded test sample.
A metal component is polycrystalline, composed of many crystals or grains. At the scale of millimeters, the deformation of a metal appears to proceed smoothly, whereas at the microscopic scale the underlying processes occurring in individual grains proceed in fits and starts. In this collaboration between researchers at Cornell University, the University of Illinois at Urbana-Champaign, the Air Force Research Laboratory and the Advanced Photon Source of Argonne National Laboratory, a high-speed detector was used to study these microscale deformation bursts in a grain-by-grain manner.

>Read more on the CHESS website

Image: The MM-PAD is shown with the vacuum cover and x-ray window removed. The 2×3 arrangement of detector modules are the brownish squares in the center.  Each module consists of 128×128 square pixels, where each pixel is 150µm of a side. Each module is roughly 2 cm x 2 cm in size. There is a 5 pixel wide (0.75 mm) inactive area between adjacent modules. (This photo is of an MM-PAD with Si, instead of CdTe sensors; otherwise, the two types of MM-PADs look identical.)

A two-pronged defense against bacterial self-intoxication

Researchers solved the structure of a bacterial toxin bound to a neutralizing protein, revealing two distinct mechanisms for how the toxin-producing bacteria avoid poisoning themselves.

Microbial communities are of fundamental importance to virtually all natural ecosystems, from the ocean floor to the gastrointestinal tract. Although the term “communities” implies cooperation, scientists now realize that bacterial colonies compete with each other for life-sustaining resources, availing themselves of a variety of strategies to reduce overcrowding. In some cases, they secrete toxins in their fight for survival. Here, researchers studied one such toxin from the bacterium Serratia proteamaculans, various strains of which live inside tree roots or inhabit the digestive tracts of insects and other animals.

Toxin targets cell division

The researchers showed that the toxin, Tre1, targets a bacterial protein, FtsZ, which is analogous to tubulin in human cells. Tubulin molecules are the building blocks of microtubules—long polymers that provide structure and shape to our cells and play an important role in cell division. In bacteria, FtsZ loses the ability to polymerize when attacked by the Tre1 toxin. Instead of dividing, the intoxicated cells grow longer and longer until they eventually split open and die (cellular elongation and lysis).

>Read more on the Advanced Light Source website

Image: Healthy bacteria (left) and bacteria (right) whose cell-division machinery has been disrupted by a toxin newly discovered in some bacterial arsenals.
Credit: Mougous Lab

Conclusion of the construction project: CHESS-U.

Fourteen months ago, Lt. Gov. Kathy Hochul came to the Cornell High Energy Synchrotron Source (CHESS) to announce a $15 million grant from the New York State Upstate Revitalization Initiative.

The URI funding was for an upgrade project – dubbed “CHESS-U” – which would arm CHESS with enhanced X-ray capabilities, keeping it a leading synchrotron source in the U.S. The project was also expected to create dozens of jobs, both at Cornell and across the region.
On Jan. 17, Hochul returned to Wilson Laboratory, the home of CHESS, to proclaim the project complete in an event that drew local lawmakers, stakeholders from Cornell, and representatives from several local and regional manufacturers whose contributions were on display during a short tour of the new experiment hutches and other equipment.
There is still some work to be done related to the project, and the linear accelerator and synchrotron beams – which were turned off for CHESS-U on June 4, 2018 – aren’t scheduled to be turned back on until Jan. 23. The event marked the official end of the construction project, for which crews worked double shifts over the final six months of 2018 in order to minimize downtime. In addition, wall and ceiling segments for most of the new experiment hutches were built off-sight at Advanced Design Consulting of Lansing and shipped to CHESS for installation. Beamlines will gradually be recommissioned in the coming months.

>Read more on the CHESS website

Image: CHESS Director Joel Brock, left, takes Lt. Gov. Kathy Hochul on a tour of the new construction at the Cornell High Energy Synchrotron Source during an event Jan. 17 to mark the conclusion of the $15 million upgrade project, known as CHESS-U.

The first observation of near-room-temperature superconductivity

For decades, room-temperature superconductivity has been one of physics’ ultimate goals, a Holy Grail-like objective that seems to keep drifting within realization yet always stubbornly out of reach. Various materials, theories, and techniques have been proposed and explored in search of this objective, but its realization has remained elusive. Yet recent experimental work on hydrogen-rich materials at high pressures is finally opening the pathway to practical superconductivity and its vast potential. Russell Hemley, a materials chemist at George Washington University in Washington, D.C., first announced evidence of superconductivity at 260 K in May, 2018, and then hints of an even higher 280 K transition in August of that year. Now Hemley, along with a team of researchers from The George Washington University and the Carnegie Institution for Science synthesized several lanthanum superhydride materials that demonstrated the first experimental evidence of superconductivity at near room temperature, and with colleagues from Argonne National Laboratory characterized them at the U.S. Department of Energy’s Advanced Photon Source (APS). Read more

Understanding the protein responsible for regulating heartbeats

A new research project uses the Canadian Light Source to help researchers understand the protein responsible for regulating heartbeats. Errors in this crucial protein’s structure can lead to potentially deadly arrhythmias, and understanding its structure should help researchers develop treatments. This protein, calmodulin (CaM), regulates the signals that cause the heart to contract and relax in almost all animals with a heartbeat.

“Usually you find some differences between versions of proteins from one species to another,” explains Filip Van Petegem, a professor in the University of British Columbia’s Department of Biochemistry and Molecular Biology. “For calmodulin that’s not the case—it’s so incredibly conserved.”

It also oversees hundreds of different proteins within the body, adjusting a broad array of cellular functions that are as crucial to our survival and health as a steady heartbeat.

>Read more on the Canadian Light Source website

Image: A surface representation of the disease mutant CaM (D95V, red) in complex with the piece of the voltage-gated calcium channel (blue).

The secret to Rembrandt’s impasto unveiled

Rembrandt van Rijn revolutionized painting with a 3D effect using his impasto technique, where thick paint makes a masterpiece protrude from the surface. Thanks to the ESRF, three centuries later an international team of scientists led by the Materials Science and Engineering Department of TU Delft and the Rijksmuseum have found how he did it.

Impasto is thick paint laid on the canvas in an amount that makes it stand from the surface. The relief of impasto increases the perceptibility of the paint by increasing its light-reflecting textural properties. Scientists know that Rembrandt, epitome of the Dutch Golden Age, achieved the impasto effect by using materials traditionally available on the 17thcentury Dutch colour market, namely lead white pigment (a mixture of hydrocerussite Pb3(CO3)2.(OH)2 and cerussite PbCO3), and organic mediums (mainly linseed oil). The precise recipe was, however, unknown until today.

>Read more on the European Synchrotron (ESRF) website

Image: Scientist Marine Cotte on beamline ID21.
Credit: Steph Candé.

Identification of a new genetic mutation associated with intellectual disability

Study contributes to the understanding of mechanisms involved in neurodevelopmental disorders

Once a disease-related protein or enzyme is identified as a therapeutic target, the study of its three-dimensional structure – the positions of each of its atoms and their interactions – allows a deeper understanding of its mechanisms of action.

This is possible not only for these substances produced by microorganisms, such as viruses or bacteria, capable of attacking our body. It is also possible, for example, to understand molecules normally produced by the human body itself, but which had their structure and function altered due to some genetic mutation.

Thus, in an article recently published in Nature Chemical Biology, Juliana F. de Oliveira, of the Brazilian Biosciences National Laboratory (LNBio), and collaborators elucidates the mechanism of action of a new genetic mutation in the UBE2A gene identified in patients with intellectual disability.

The UBE2A gene is located on the X chromosome and encodes the protein of the same name that participates in the process of “labeling” defective proteins inside the cell. This labeling is done by adding and protein called ubiquitin to the defective proteins as if it were a label. Next, under normal conditions, the defective proteins are sent for degradation.

>Read more on the Brazilian Synchrotron Light Laboratory (LNLS) website

Image: Overlap of the patient’s UBE2A protein structure (blue) with the normal protein (gray) evidences similarity between them. On the right, it is shown in detail the only altered amino acid in the patient’s protein due to the genetic mutation.

Tomography beamline at SESAME is officially launched

On 1st January 2019, the European Horizon 2020 project BEAmline for Tomography at SESAME (BEATS) was launched with the objective to design, procure, construct and commission a beamline for hard X-ray full-field tomography at the SESAME synchrotron in Jordan.

The European grant is worth 6 million euros and will span a four-year period from beginning 2019 to end 2022.
Led by the ESRF, the European synchrotron (France), BEATS involves leading research facilities in the Middle East (SESAME and the Cyprus Institute), and European synchrotron radiation facilities ALBA-CELLS (Spain), DESY (Germany), the ESRF (France), Elettra (Italy), INFN (Italy), PSI (Switzerland), SESAME (Jordan) and SOLARIS (Poland). The initiative is funded by the European Union’s Horizon 2020 research and innovation programme.

Nine partner institutes will join forces to lay the groundwork for the efficient and sustainable operation of the SESAME research infrastructure. Through the development and consolidation of the scientific case for a beamline for tomography, and actions to fortify the scientific community, the partners will pay particular attention to the R&D and technology needs of the SESAME Members. Built upon the OPEN SESAME project, BEATS will address the issue of sustainability of operation by preparing medium- to long-term funding scenarios for the tomography beamline and the facility.

>Read more on the European Synchrotron (ESRF) website

Mapping terrestrial analogs for martian samples

Internships at Brookhaven’s National Synchrotron Light Source II helped turn her love for rocks into serious study.

Catherine Trewhella, a recent graduate from the University of Massachusetts, Amherst, and current intern at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, is taking a microscopic look at rocks at the National Synchrotron Light Source II (NSLS-II), a DOE Office of Science user facility. Her research will help prepare scientists for analyzing samples brought back from outer space, specifically Mars.
Trewhella is currently interning as a part of Brookhaven Lab’s Office of Educational Programs’ Supplemental Undergraduate Research Program (SURP). Over the course of the fall, she has been using NSLS-II’s Submicron Resolution X-ray Spectroscopy (SRX) beamline to map out the chemical make-up of terrestrial analogs for Martian samples.
“They’re terrestrial rocks,” she said. “But what makes them worth the closer look is researchers believe they’re similar to rock formations expected on Mars.” These x-ray fluorescence images (XRF) will therefore help scientists better understand what they are seeing when studying Martian samples.

>Read more on the National Synchrotron Light Source II (NSLS-II) website

Image: Catherine Trewhella at the Submicron Resolution X-ray Spectroscopy (SRX) beamline at the National Synchrotron Light Source II (NSLS-II) at Brookhaven Lab.