Looking into the heart of an antibiotic killer

β-lactam-based antibiotics currently account for about 65% of all applied antibiotics, due to their broad-spectrum of activity and favorable safety profile, making this class of drugs the most common clinical approach for treating bacterial infections. Examples of these drugs, which contain a β-lactam ring in their structure, include naturally occurring penicillins, and synthetic cephalosporins, monobactams, and carbapenems. Antibiotics with a β-lactam core target bacterial transpeptidases—enzymes necessary for cell-wall synthesis—and they block the formation of cross-bridges between adjacent peptidoglycan chains, leading to bacterial death. Overuse of β-lactam antibiotics has led to an increase in microorganisms with multidrug resistance. In β-lactam antibiotics, this resistance is driven primarily by bacterial enzymes called b-lactamases. Researchers have now revealed the crystal structure, binding, and cleavage of moxalactam antibiotic bound to L1 metallo-β-lactamase (MBL) from the emerging pathogen Stenotrophomonas maltophilia using the U.S. Department of Energy’s Advanced Photon Source (APS). Drug discovery based on the details captured in this study could contribute key information to counteract antimicrobial resistance and provide tools in future pandemics. The results were published in the journal Nature Communications.

Read more on the APS website

Image: Fig. 1. TR-SSX crystal structure of moxalactam of the active site of L1 MBL, L1 active site structure at 150 ms with hydrolyzed moxalactam (in yellow-red-blue), zinc (magenta) and protein residues (in silver-blue-red).

Shining a light on the Australian Synchrotron’s $100M BRIGHT beamlines

A special inaugural event held by ANSTO at its Australian Synchrotron for more than 30 funding organisations has showcased the first of the $100 million BRIGHT Program’s brand new, state-of-the-art beamlines.

The event, at the Clayton facility in Melbourne on Friday 9 December, also marked the official welcoming of the BRIGHT Program’s latest funding partnership with the University of South Australia as the 32nd contributor to provide additional capital funding for the construction of new beamlines.

Since 2018, the BRIGHT Program has received joint funding from leading Australian universities and medical research institutes, New Zealand government, universities and crown research institutes, via the New Zealand Synchrotron Group, and the Australian government through the CSIRO, Defence Science and Technology Group, and ANSTO.

The program is enabling the design, installation, and commissioning of eight new beamlines at the Australian Synchrotron to meet the growing demand of these sophisticated technologies by Australian and international researchers and industry partners.

Read more on the ANSTO website

Image: Prof Michael James, Senior Principal Scientist , Australian Synchrotron and Prof Enzo Lombi  of the University of South Australia. UniSA has announced funding support for the program.

Fred Mosselmans’ #My1stLight

This is the first EXAFS dataset I recorded for my PhD in December 1987 at station 9.2 of the SRS. It is of a molybdenum foil. I had been to the SRS after its HBL upgrade to help out on other peoples beamtimes but this is the first dataset that was part of my project. I went on to work at Daresbury and then Diamond, but when I recorded it using a monochrome Textronix terminal, I had no idea I would spend my working life collecting thousands of EXAFS and related spectra. The data was saved to a 3.5 “ floppy disk. The file takes up 35 kB and has a date stamp of “791022”, which I don’t understand, was started at 4 minutes to 7 in the morning with the ring current at 70mA.

Fred Mosselmans is Principal Beamline Scientist for Diamond’s I20 beamline LOLA: Versatile X-ray Spectroscopy

Mirian Garcia-Fernandez’s #My1stLight

Diamond’s I21 Resonant Inelastic X-ray Scattering (RIXS) beamline achieved first light in 2016. Mirian’s #My1st Light contribution shows the I21 team in the Diamond Control Room observing this fantastic achievement.

I21 is a dedicated Resonant Inelastic soft X-ray Scattering (RIXS) beamline that provides a highly monochromatised, focused and tunable X-ray beam onto materials, while detecting and energy-analysing scattered X-rays using a spatially-resolved two-dimensional detector. By studying the energy and momentum differences between the incident and the outgoing X-rays, one can obtain information such as the local lattice structure (local crystal field), electron orbitals (orbital excitations), collective lattice vibration (phonons), magnetic (spinons/magnons) and charge excitations of the material under investigation.

Find out more on the beamline’s webpage

Milestone for laser technology

Research team demonstrates free-electron laser driven by plasma accelerated electron beams and seeded by additional light pulses.

Extremely intense light pulses generated by free-electron lasers (FELs) are versatile tools in research. Particularly in the X-ray range, they can be deployed to analyze the details of atomic structures of a wide variety of materials and to follow fundamental ultrafast processes with great precision. Until now, FELs such as the European XFEL in Germany are based on conventional electron accelerators, which make them long and expensive. An international team led by Synchrotron SOLEIL, France, and Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Germany, has now achieved a breakthrough on the way to an affordable alternative solution: they were able to demonstrate seeded FEL lasing in the ultraviolet regime based on a still young technology – laser-plasma acceleration. In the future, this might allow to build more compact systems, which would considerably expand the possible applications of FELs. The research collaboration presents their results in the journal Nature Photonics Nature Photonics (DOI: 10.1038/s41566-022-01104-w).

Read more on the HZDR website

Image: Together with colleagues from Synchrotron SOLEIL, LOA, PhLAM and HZDR, the German-French team succeeded for the first time in generating well-controllable laser light in a free-electron laser via plasma acceleration (Dr. Marie-Emanuelle Couprie, Dr. Arie Irman, Prof. Ulrich Schramm, Dr. Marie Labat, Dr. Amin Ghaiht, Dr. Maxwell LaBerge, Dr. Driss Oumbarek-Espinos, Dr. Alexandre Loulergue, Dr. Jurjen Couperus Cabadağ, Patrick Ufer, Dr. Yen-Yu Chang; from left to right)

Credit: HZDR/Sylvio Dittrich

A toothy temporal map of Arctic climate change

In the vast, remoteness of the Arctic, few have the opportunity to gather data on the environmental conditions over time or decipher the long-term effects of climate change. What is required? A considerable period to observe, a nearly autonomous method or actor for collection, a robust character to withstand the harsh surroundings. Researchers from Aarhus University in Denmark are tackling this issue through an interdisciplinary NordForsk project. At DanMAX beamline, the group will analyse a narwhal tusk to determine its chemical composition and biomineralization, both important potential markers of the changing environment.

Significant, accelerated signs of climate change have been reported in the Arctic and Antarctic zones, which research shows impact global climate. Scientists are looking at different ways to interpret the terrestrial and oceanic changes occurring in these areas, and how the change affects native wildlife. The described NordForsk project, developed by researchers from Denmark, Greenland and Sweden, seeks to elucidate the structure and formation of the narwhal tusk, and map the full life history of the animal through the growth lines along the full length of the tusk.

Read more on the MAX IV website

Image: Peter A. S. Vibe readies samples of the tusk at DanMAX beamline. 

Credit: MAX IV Laboratory

#SyncroLightAt75 – Structure of the Ribosome

Along with Ada Yonath and Thomas Steitz,Venkatraman Ramakrishnan from the MRC Laboratory of Molecular Biology in Cambridge, UK was awarded the 2009 Nobel Prize in Chemistry for determining the structure of the ribosome, one of the largest and most important molecules in the cell. X-ray crystallography experiments that enabled elucidation of the ribosome structure used synchrotron light from a number of light sources worldwide, each with unique capabilities, including the Swiss Light Source SLS.

Read more on the PSI website

Image: Interior view of the experimental hall at the Swiss Light Source SLS

Credit: Photo: H.R. Bramaz/PSI

Nanoparticles made from marine polymers for cutaneous drug delivery applications

A research led by the University of Porto in collaboration with the ALBA Synchrotron has studied for the first time the interaction of nanoparticles with the skin, using synchrotron light at the MIRAS beamline. The findings unveil the role of the different skin components and the mechanism of the permeation enhancement conferred with nanoparticles, made from marine polymers. A nano delivery system application in the skin will reduce the dosage needed due to controlled drug delivery and allow newer and better-targeting therapeutic strategies towards cutaneous administration.

Cutaneous drug delivery allows the administration of therapeutic and cosmetic agents through the skin. Advantages of this administration route include high patient compliance, avoidance of high concentration levels of the drug when reaching systemic circulation, and far fewer side effects compared to other administration routes.

Still, the peculiar skin structure assures protection to the human organism and hampers drug delivery. To overcome this issue, skin permeation enhancers, such as nanoparticles, can be used. They are pharmacologically inactive molecules that can increase skin permeability by interacting with the stratum corneum, the first layer of the epidermis, which is the outermost layer of the skin. However, the mechanisms of nanoparticles’ interaction with the skin structure are still unknown.

A research project led by the University of Porto (Portugal) in collaboration with the ALBA Synchrotron has studied for the first time the interaction of polymeric nanoparticles with the skin, using synchrotron light.

Read more on the ALBA website

Image: Nanoparticles made visible on human skin – 3D Rendering

Credit: Adobe Stock

Innovative fuels for Small Modular Reactors

If Canada is to meet its target of net-zero emissions by 2050, our country must transition to a diverse, innovative range of alternative sources of energy.

Mouna Saoudi, a materials scientist at Canadian Nuclear Laboratories (CNL), is using the Canadian Light Source at the University of Saskatchewan to explore how advanced nuclear fuels for small modular reactors (SMRs) could be used to help fill the gap between fossil fuels and renewables.

“SMRs would be an efficient way to reach net zero by 2050, which is an ambitious but hopefully achievable goal,” says Saoudi.

SMRs can power electrical grids, provide process heat, and offer energy solutions for various industries — such as remote mining operations.

Saoudi is currently investigating how types of advanced nuclear fuels behave under different reactor conditions.

“My main focus is characterization of advanced nuclear fuels for potential use in small modular reactors,” Saoudi says.

The advanced fuels combine uranium oxide — the main element used in nuclear fuel for decades —with the naturally occurring and abundant element thorium in oxide form. Saoudi says that there are many advantages to mixing the two elements, including increased efficiency and better in-reactor performance.

Using the HXMA beamline, Saoudi was able to confirm the similar distribution of the two elements, uranium and thorium, in the mixed fuel oxides. Saoudi believes this was the first time the CLS has been used for this type of study.

Saoudi has been working with USask researcher Andrew Grosvenor from the Department of Chemistry. Their findings were recently published in the Journal of Nuclear Materials.

The CLS allowed Saoudi and her collaborators to investigate the electronic and local structure of the fuel — crucial information needed to identify the optimum fuel composition that would have better in-reactor performance than that of uranium oxide.

Read more on the CLS website

Image: (Left to right) Dr. Than Do, Dr. Mouna Saoudi, and Dr. Julien Lang, R&D scientists at Canadian Nuclear Laboratories (CNL).

Ultrafast all-optical spin injection in silicon revealed at FERMI

A revolutionary and energy-efficient information technology encoding digital data in electron spin (spintronics) by combining semiconductors and ferromagnets is being developed worldwide. Merging of memory and logic computing of magnetic based storage devices and silicon-based logic transistors is expected to ultimately lead to new computing paradigms and novel spin-based multifunctional devices. The advantages of this new technology would be non-volatility, increased data processing speed, reduced electric power consumption. All of them are essential steps towards next generation quantum computers.

To create spin-based electronics with potential to revolutionize information technology, silicon, the predominant semiconductor, needs to be integrated with spin functionality. Although silicon is non-magnetic at equilibrium, spin polarized currents can be established in Si by a variety of approaches such as the use of polarized light, hot electrons spin injection, tunnel spin injection, Seebeck spin tunneling and dynamical spin pumping methods, as had been demonstrated recently. In general, spin polarized currents refer to the preferential alignment of the spin angular momentum of the electrons in a particular direction.

Read more on the Elettra website

Image: Figure 1: a) the optical generation of spin polarized superdiffusive currents across a ferromagnetic/semiconductor interface is illustrated. b) the principles of TR-MOKE experiment are illustrated  together with a cross-section TEM image describing the quality of the Ni/Si interface.

Cellulose-based actuators can be programmed and repair themselves

Smart gifts will soon unwrap themselves

With the help of the high-brilliance X-ray source PETRA III, a German-Swedish research group has developed a new cellulose polymer material that can be specifically animated to move by moisture, making it an ideal base material for programmable actuators. In addition, the composite material is also very resistant to stretching and able to repair itself, as the group reports in the scientific journal “Advanced Functional Materials”. The mechanism of this self-healing in particular was investigated at PETRA III.

n nature, fascinating functions and mechanisms have prevailed over millions of years of evolution. In bionics research, scientists try to copy and reproduce these efficient methods from nature. For example, in sensors or bionic actuators, active elements that – controlled by a signal – can switch or move something. Modern actuators should be programmably stimulable, very robust and able to cope with a wide range of working conditions.

The research team with members from the Royal Institute of Technology Stockholm (KTH), DESY and the Helmholtz Centre for Heavy Ion Research has now produced a thin film of cellulose nanofibres with two types of polymers, following the example of biological tissue. To do this, they mixed polyvinyl alcohol (PVA) and polystyrene sulfonate (PSS) with the cellulose fibrils and poured the solution onto a glass plate. When it dried out, a circular film was formed in which a tight network of chemical and physical bonds formed. “It is the polystyrene sulphonate in particular that makes the film extremely stretchable and tough,” says DESY scientist Qing Chen, first author of the study. “This ingredient of the solution can be broadened by mixing food colouring agents, thus making it more colourful and diverse.”

Pieces up to several centimetres in size can be cut out of this film, which bend when exposed to moisture. “In principle, we can make an active wrapping paper out of the material,” says Stephan Roth (DESY and KTH), head of the PETRA III beamline P03 and co-author of the study, “you just have to spray some moisture on it, and it unwraps itself.”

Read more on the DESY website

Image: The cellulose polymer actuators can be used for a variety of purposes.

Credit: DESY, Qing Chen

Formation of the defect dipoles around dopants demonstrated in dielectric ceramics

A team of international scientists from China, Germany, Norway and Pakistan with SESAME staff have used the BM08 – XAFS/XRF beamline at SESAME for high dielectric constant materials that are of particular interest as indispensable components in electronics. The authors have demonstrated a new approach for optimizing the dielectric properties by acceptor–donor co-doping in (Gax, Cuy) Zn1−x–yO films fabricated with pulse laser deposition (PLD) or, alternatively, exchanging the co-doping step by ion implantation. Exploitation of defect engineering in dielectric ceramics for enhancing performance is an active research area globally. Materials with high dielectric constant (k) and low loss throughout a wide frequency range are among the key components for the device size scale-down in nanoelectronics. The XAFS study performed at SESAME revealed the formation of the defect dipoles around dopants.

Read more on the SESAME website

Image: Examples of the X-ray analysis. a) XPS data showing the Cu 2p spectra for the Cu8Zn92O and Ga0.5Cu8Zn91.5O films. b) The X-ray absorption near edge structure (XANES) spectra at the Cu K-edge of Cu8Zn92O and Ga0.5Cu8Zn91.5O samples including reference samples, e.g., Cu foil and CuO powder. c) Magnitude of the Fourier transform of the extended X-ray absorption fine structure (EXAFS) spectra. d) Fourier transform of Real χ at the Zn K-edge of Ga0.5Zn99.5O, Cu8Zn92O, and Ga0.5Cu8Zn91.5O samples compared with theoretical model (black lines).

Advanced Light Source upgrade approved to start construction

Berkeley Lab’s biggest project in three decades now moves from planning to execution. The ALS upgrade will make brighter beams for research into new materials, chemical reactions, and biological processes.

The Advanced Light Source (ALS), a scientific user facility at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), has received federal approval to start construction on an upgrade that will boost the brightness of its X-ray beams at least a hundredfold.

“The ALS upgrade is an amazing engineering undertaking that is going to give us an even more powerful scientific tool,” said Berkeley Lab Director Michael Witherell. “I can’t wait to see the many ways researchers use it to improve the world and tackle some of the biggest challenges facing society today.”

Scientists will use the upgraded ALS for research spanning biology; chemistry; physics; and materials, energy, and environmental sciences. The brighter, more laser-like light will help experts better understand what’s happening at extremely small scales as reactions and processes take place. These insights can have a huge array of applications, such as improving batteries and clean energy technologies, creating new materials for sensors and computing, and investigating biological matter to develop better medicines.

“That’s the wonderful thing about the ALS: The applications are so broad and the impact is so profound,” said Dave Robin, the project director for the ALS upgrade. “What really excites me every day is knowing that, when it’s complete, the ALS upgrade will enable researchers to make scientific advances in many different areas for the next 30 to 40 years.”

The DOE approval, known as Critical Decision 3 (CD-3), formally releases funds for purchasing, building, and installing upgrades to the ALS. This includes constructing an entirely new storage ring and accumulator ring, building four feature (two new and two upgraded) beamlines, and installing seismic and shielding upgrades for the concrete structure housing the equipment. The $590 million project is the biggest investment at Berkeley Lab since the ALS was built in 1993.

Read more on the Berkeley Laboratory website

Image: The upgrade to the Advanced Light Source at Berkeley Lab will add two new particle accelerator rings within the iconic building’s footprint. 

Credit: Thor Swift/Berkeley Lab

Influence of alloying on slip intermittency and implications for dwell fatigue in titanium

The high precision of HEDM measurements at FAST offer new insight into the microscopic processes that cause dwell fatigue, pointing toward new alloying strategies for mitigation.

What is the discovery?

Titanium alloys exhibit a phenomenon known as dwell fatigue: when the alloys are held under persistent loads as low as 60% of yield stress, their fatigue lifetime is gradually reduced. The culprit for this degradation in performance is believed to be dislocation slip, which is an intermittent, scale bridging phenomenon, not unlike a nanoscale earthquake occurring in the alloy. Sudden dislocation slips can induce large stress bursts and initiate crack formation. In a new publication appearing in Nature Communications, a team lead by Felicity Worsnop (MIT) and David Dye (Imperial College London) has used high-energy diffraction microscopy at the FAST beamline at CHEXS to observe and quantify thousands of sudden “stress drop” events in thousands of different crystalline grains inside titanium alloys held under dwell fatigue conditions. The team was able to collect unprecedentedly precise statistics for the probability for different types of stress drop events to occur in different alloys. The figure below shows the probability for stress drops with magnitude equal to or greater than Δτ̅ and associated with the possible 3 slip modes (illustrated at right), in 4 different alloys (a – disordered Ti-7AL, low oxygen content; b – higher oxygen content; c – low oxygen, after aging; d – high oxygen, after aging). They discover that interstitial oxygen promotes slip homogeneity, with a higher frequency of smaller stress drops being observed, whereas precipitation of regions with aluminum ordering results in fewer, larger events. Basal slip is observed to be the most common of the slip modes and gives rise to the largest slip events.

Read more on the CHESS website

Watching nanoparticle chemistry and structure evolve

Using a multimodal approach developed at the Advanced Light Source (ALS), researchers learned how chemical properties correlate with structural changes during nanoparticle growth.

The work will enable a greater understanding of the mechanisms affecting the durability of nanoparticles used to catalyze a broad range of chemical reactions, including clean-energy reactions.

Catalyzing technological progress

In applications ranging from chemical synthesis to energy storage, catalysts enable chemical reactions to run at more favorable temperatures, pressures, or in general, with lower energy requirements. For example, catalysts enable the efficient splitting of water to generate hydrogen, which can then be used as a clean, decarbonized fuel.

For such applications, nanoparticles on the surface of a transition-metal oxide work well as catalysts, but they are susceptible to coarsening, agglomeration, and other forms of degradation, shortening their usable lifetime. In this work, researchers applied a technique they developed at the ALS to simultaneously study the chemistry and structure of catalyst materials as they form, a capability that will help scientists identify strategies for improving nanoparticle durability.

Understanding nanoparticle exsolution

A process called “exsolution” has shown significant promise for controlling nanoparticle size, shape, distribution, and stability. Briefly, the process involves causing dopant atoms in a host matrix to migrate to the surface and gather to form nanoparticles. This is done by heating the host material under reducing conditions (i.e., in a reducing gas such as hydrogen). Exsolution from metal oxide hosts produces highly stable metal nanoparticles that are often partially embedded in the oxide surface and show high activity for the oxygen evolution reaction (OER), a key step in many electrochemical reactions, including water splitting.

Here, the samples studied were thin films of SrTi0.9Nb0.05Ni0.05O3-δ (STNNi). When STNNi is heated in H2 gas, the Ni atoms migrate to the surface and form nanoparticles. Before the reducing treatment, such samples are inactive with respect to the OER. After treatment, the system becomes active, despite a relatively small amount of Ni doping.

Read more on the ALS website

Image: Atomic force microscope images of nickel- and niobium-co-doped strontium titanate, before (left) and after (right) thermal treatment in a reducing (H2) atmosphere. After treatment, bright features consistent with the formation of nickel nanoparticles are observed.