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

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

WE51 SSRL Slider

The Stanford Synchrotron Radiation Lightsource (SSRL) is one of the pioneering synchrotron facilities in the world, known for outstanding user support, training future generations and important contributions to science and instrumentation. SSRL is an Office of Science User Facility operated for the U.S. Department of Energy by Stanford University.

Week51 FERMI Slider

The program of construction and commissioning through user experiments of the FEL source FERMI, the only FEL user facility in the world currently exploiting external seeding to offer intensity, wavelength and line width stability, achieved all of its intended targets in 2017.

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.