Translucency of graphene to van der Waals forces

If in the infinitely large it is the gravitational force that determines the evolution in space and time of planets, stars and galaxies, when we focus our observation on the atomic scale other are the forces that allow materials to exist. These are forces that, like a “special glue”, allow atoms and molecules to aggregate to form living and non-living systems. Among them we find one that, although discovered 150 years ago by Johannes Diderik van der Waals (vdW), still carries with it some aspects of ambiguity. Van der Waals was the first to reveal its origin and to give a first and simple analytical description, even though it took more than a century, with the new discoveries of quantum field theory, to be able to fully understand its quantum character and its relation to the vacuum energy and Casimir force. And only in the last 30 years it has been realized how much this force pervades the natural world. One of the wonders is represented by the geckos, who use these forces to climb vertical and smooth walls thanks to the vdW forces, which are enhanced because of the multitude of hairs present in each finger of their legs. These forces are also known to affect the stability of the double helix of the DNA and are also responsible for the interactions between different groups of amino acids.
What makes the vdW force unique is the fact that it is the weakest of the inter-atomic and inter-molecular forces present in nature and therefore it remains extremely difficult to measure with great accuracy. At the same time, even the inclusion of these force in the most accurate methods of calculation has not yet found a universal solution and the different approaches used by theoretical physicists and chemists to take them into account can sometimes lead to conflicting results.

>Read more on the Elettra website

Image:   CO desorption from Gr/Ir(111). (a) Selected spectra of the uptake corresponding to θCO=0.08 ML (bottom) and 0.30 ML (top). (b) TP-XPS C 1s core level spectra showing its evolution during thermal desorption of CO from Gr/Ir(111). (c) Comparison of CO coverage evolution as a function of temperature for selected CO initial coverages. 

More magnets, smoother curves: the Swiss Light Source upgrade

The Swiss Light Source SLS is set to undergo an upgrade in the coming years: SLS 2.0.

The renovation is made possible by the latest technologies and will create a large-scale research facility that will meet the needs of researchers for decades to come.

Since 2001, “the UFO” has been providing reliable and excellent service: In the circular building of the Swiss Light Source SLS, researchers from PSI and all over the world carry out cutting-edge research. For example, they can investigate the electronic properties of novel materials, determine the structure of medically relevant proteins, and make visible the nanostructure of a human bone.
“Internationally, the SLS has been setting standards for nearly two decades”, says Terence Garvey, SLS 2.0 accelerator project head. Now, Garvey continues, it’s time for a modernisation. In the coming years, SLS is expected to undergo an upgrade with the project title SLS 2.0. SLS will remain within the same UFO-shaped building, but will get changes in crucial areas inside. Garvey is one of the two project leaders for the upgrade, together with Philip Willmott.

Swiss Light Source (SLS) , , ,

Inventing a way to see attosecond electron motions with an X-ray laser

Called XLEAP, the new method will provide sharp views of electrons in chemical processes that take place in billionths of a billionth of a second and drive crucial aspects of life.

Researchers at the Department of Energy’s SLAC National Accelerator Laboratory have invented a way to observe the movements of electrons with powerful X-ray laser bursts just 280 attoseconds, or billionths of a billionth of a second, long.

The technology, called X-ray laser-enhanced attosecond pulse generation (XLEAP), is a big advance that scientists have been working toward for years, and it paves the way for breakthrough studies of how electrons speeding around molecules initiate crucial processes in biology, chemistry, materials science and more.
The team presented their method today in an article in Nature Photonics.

“Until now, we could precisely observe the motions of atomic nuclei, but the much faster electron motions that actually drive chemical reactions were blurred out,” said SLAC scientist James Cryan, one of the paper’s lead authors and an investigator with the Stanford PULSE Institute, a joint institute of SLAC and Stanford University. “With this advance, we’ll be able to use an X-ray laser to see how electrons move around and how that sets the stage for the chemistry that follows. It pushes the frontiers of ultrafast science.”

Image: A SLAC-led team has invented a method, called XLEAP, that generates powerful low-energy X-ray laser pulses that are only 280 attoseconds, or billionths of a billionth of a second, long and that can reveal for the first time the fastest motions of electrons that drive chemistry. This illustration shows how the scientists use a series of magnets to transform an electron bunch (blue shape at left) at SLAC’s Linac Coherent Light Source into a narrow current spike (blue shape at right), which then produces a very intense attosecond X-ray flash (yellow).
Credit: Greg Stewart/SLAC National Accelerator Laboratory

>Read more on the Linear Coherent Light Source (SLAC) website

First electrons turn in the ESRF’s Extremely Brilliant Source Storage Ring

This is an important milestone on the way to opening to the international scientific community the first high-energy fourth-generation synchrotron light source, known as EBS – Extremely Brilliant Source.

It marks the successful completion of the engineering and installation of a worldwide-unique accelerator within the existing ESRF infrastructure, and the start of the commissioning phase of a brand-new generation of high-energy synchrotron.
Expectation was high in the ESRF’s control room on 2 December as teams carefully monitored the first turns of the electrons around the new EBS storage ring. “Seeing the first electrons circulating is a huge achievement and proof of the hard work and expertise of the teams who have been working on this since 2015,” said Pantaleo Raimondi, ESRF accelerator and source director and EBS storage ring concept inventor and project leader. “It’s a great moment for all involved.”

>Read more on the ESRF website

Image: The first three turns of electrons in the new EBS storage ring.

One of Sirius’ most important steps: first electron loop around the storage ring

This is one of the most important stages of the largest scientific project in Brazil .

The Sirius project has just completed one of its most important steps: the first electron loop around its main particle accelerator, called the Storage Ring. In this large structure, 518 meters in circumference, the electrons accelerated to very high energies produce synchrotron light: a very bright light used in scientific experiments that could revolutionize knowledge in health, energy, materials and more.
The first loop demonstrates that thousands of components such as magnets, ultra-high-vacuum chambers and sensors are working in sync, and that the entire structure, with parts weighing hundreds of kilograms, have been aligned to micrometer standards (up to five times smaller than a strand of hair) needed to guide the trajectory of the particles.
Sirius is the largest and most complex scientific infrastructure ever built in Brazil and one of the first 4th generation synchrotron light source to be built in the world and it was designed to put Brazil at the forefront of this type of technology.

The next steps of the project include concluding the assembly of the first beamlines: the research stations where scientists conduct their experiments. These stations allow researchers to study the structure of virtually any organic and inorganic materials, such as proteins, viruses, rocks, plants, soil, alloys, among many others, in the atomic and molecular scale with very high resolution and speed.

>Read more on the LNLS (CNPEM) website

Picture: first loop around the storage ring.

Asia-Oceania Forum for Synchrotron Radiation Research in Tawain

The Asia-Oceania Forum for Synchrotron Radiation Research (AOFSRR) was formally established in 2006. The current members include Australia, China, India, Japan, Malaysia, New Zealand, South Korea, Singapore, Taiwan, Thailand, and Vietnam. Its objective is to strengthen collaboration among the synchrotron radiation (SR) facilities and to promote SR sciences and accelerator-based research in the Asia-Oceania region.

Image: Students performed experiments and analyzed data at various endstations.

Read more on the NSRRC website

New biocompatible nanoparticles for breast cancer therapy

A research team has studied the efficacy of new CHO/PA polymeric nanoparticles for the sustained delivery of a drug used in breast cancer therapy. Some of the experiments have been carried out in the NCD-SWEET beamline at ALBA.

According to data from the Spanish Association against Cancer (AECC) observatory, breast cancer is the second most common type of cancer in Spain with 33,307 new cases in 2019. The number of deceased has reached 6,689 this year. Many research groups are exploring new ways to fight against this disease.
Dasatinib, an FDA-approved compound for the treatment of chronic myeloid leukemia, has become a potential candidate for the treatment of other cancers. It has been recently demonstrated that it could have a relevant role in breast cancer therapy. However, the solubility of this compound is extremely low, leading to poor absorption by the organism. Thus, the administration of a higher dosage is needed in order to obtain a better effect.
An alternative solution to enhance its therapeutic effect is the development of polymeric nanoparticles for a sustained and controlled delivery of the drug.
>Read more on the ALBA website

Image: 2D SAXS and WAXS patterns of the CHO/PA nanoparticles recorded at NCD-SWEET beamline, which confirm the lack of well-structured mesophase.

 

First molecular movies at European XFEL

Scientists show how to use extremely short X-ray pulses to make the first movies of molecular processes at the European XFEL.

In a paper published today in Nature Methods, scientists show how to effectively use the high X-ray pulse repetition rate of the European XFEL to produce detailed molecular movies. This type of information can help us to better understand, for example, how a drug molecule reacts with proteins in a human cell, or how plant proteins store light energy.

Traditional structural biology methods use X-rays to produce snapshots of the 3D structure of molecules such as proteins. Although valuable, this information does not reveal details about the dynamics of biomolecular processes. If several snapshots can be taken in fast enough succession, however, these can be pasted together to make a so-called molecular movie. The high repetition rate of the extremely short X-ray pulses produced by the European XFEL makes it now possible to collect large amounts of data to produce movies with more frames than ever before. An international group of scientists have now worked out how to make optimal use of the European XFEL’s very high X-ray repetition rate to make these molecular movies at the facility in order to reveal unprecedented details of our world.

>Read more on the European XFEL website

Image: Artistic visualisation of a serial crystallography experiment. A stream of crystalline proteins are struck by an optical laser that initiates a reaction. Following a short delay the X-ray laser strikes the crystals. The information recorded about the arrangement of the atoms in the protein is used to reconstruct a model of the structure of the protein.
Credit: European XFEL / Blue Clay Studios

Canadian researchers extend the life of rechargeable batteries

Carbon coating that extends lithium ion battery capacity by 50% could pave the way for next-generation batteries in electric vehicles.

Researchers from Western University, using the Canadian Light Source (CLS) at the University of Saskatchewan, found that adding a carbon-based layer to lithium-ion rechargeable batteries extends their life up to 50%.
The finding, recently published in the journal ACS Applied Materials and Interfaces, tackles a problem many Canadians will be familiar with: rechargeable batteries gradually hold less charge over time.
“We added a thin layer of carbon coating to the aluminum foil that conducts electric current in rechargeable batteries,” said lead researcher Dr. Xia Li of Western University. “It was a small change, but we found the carbon coating protected the aluminum foil from corrosion of electrolyte in both high voltage and high energy environments – boosting the battery capacities up to 50% more than batteries without the carbon coating.”

>Read more on the Canadian Light Source website

Image: Dr. Li in the lab. 

A fast and precise look into fibre-reinforced composites

Researchers at the Paul Scherrer Institute PSI have improved a method for small angle X-ray scattering (SAXS) to such an extent that it can now be used in the development or quality control of novel fibre-reinforced composites.

This means that in the future, such materials can be investigated not only with X-rays from especially powerful sources such as the Swiss Light Source SLS, but also with those from conventional X-ray tubes. The researchers have published their results in the journal Nature Communications.
Novel fibre-reinforced composites are becoming increasingly important as stable and lightweight materials. One example of this type of composite is carbon fibre reinforced polymers (CFRP), which are used in aircraft construction or in the construction of Formula 1 racing cars and sports bicycles. The properties of these materials depend to a large extent on how the tiny fibres are aligned and how they are arranged and embedded in the surrounding material, influencing the mechanical, optical, or electromagnetic behaviour of the composites.

To investigate the fibre’s orientation in such composites, researchers must look inside them. One could use small angle X-ray scattering (SAXS), exploiting the fact that X-rays are scattered when they penetrate matter. The resulting scattering pattern can then be used to obtain information about the interior of a sample and potentially the orientation of the fibres. However, the common SAXS methods have the disadvantage of being quite slow: It can take up to several hours to scan centimetre-sized specimens with the required resolution.

>Read more on the Swiss Light Source (PSI) website

Image: Matias Kagias (left) and Marco Stampanoni in front of the apparatus with which they examined the composites using the newly developed X-ray method. Both hold one of the workpieces that have been X-rayed.
Credit: Paul Scherrer Institute/Mahir Dzambegovic

Egyptian mummy bones explored with X-rays and infrared light

Researchers from Cairo University work with teams at Berkeley Lab’s Advanced Light Source to study soil and bone samples dating back 4,000 years.

Experiments at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) are casting a new light on Egyptian soil and ancient mummified bone samples that could provide a richer understanding of daily life and environmental conditions thousands of years ago.
In a two-monthslong research effort that concluded in late August, two researchers from Cairo University in Egypt brought 32 bone samples and two soil samples to study using X-ray and infrared light-based techniques at Berkeley Lab’s Advanced Light Source (ALS). The ALS produces various wavelengths of bright light that can be used to explore the microscopic chemistry, structure, and other properties of samples.
Their visit was made possible by LAAAMP – the Lightsources for Africa, the Americas, Asia and Middle East Project – a grant-supported program that is intended to foster greater international scientific opportunity and collaboration for scientists working in that region of the globe.

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

Image: From left, Cairo University postdoctoral researcher Mohamed Kasem, ALS scientist Hans Bechtel, and Cairo University associate professor Ahmed Elnewishy study bone samples at the ALS using infrared light.
Credit: Marilyn Sargent/Berkeley Lab

Using European XFEL to shed light on photosynthesis

First membrane protein studied at European XFEL

In a paper now published in Nature Communications an international group of scientists show that the fast X-ray pulse rate produced by the European XFEL can be used to study the structure of membrane proteins such as those involved in the process of photosynthesis. These results open up eagerly awaited experimental opportunities for scientists studying these types of proteins.

Large proteins and protein complexes are difficult to study with traditional structural biology approaches. Large protein complexes, such as those that sit across cell membranes and regulate traffic in and out of cells, are difficult to crystalize and generally only produce small crystals that are hard to analyse. The extremely fast X-ray pulses generated by European XFEL now enable scientists to collect large amounts of data from a stream of small crystals to develop detailed models of the 3D structure of these proteins.

>Read more on the European XFEL website

Image (extract, full illustration in the article): Graphic shows the basic design of a serial femtosecond crystallography experiment at European XFEL. X-ray bursts strike crystallized samples resulting in diffraction patterns that can be reassembled into detailed images.
Credit: Shireen Dooling for the Biodesign Institute at ASU

Machine learning enhances light-beam performance at the ALS

Successful demonstration of algorithm by Berkeley Lab-UC Berkeley team shows technique could be viable for scientific light sources around the globe.

Synchrotron light sources are powerful facilities that produce light in a variety of “colors,” or wavelengths – from the infrared to X-rays – by accelerating electrons to emit light in controlled beams.
Synchrotrons like the Advanced Light Source at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) allow scientists to explore samples in a variety of ways using this light, in fields ranging from materials science, biology, and chemistry to physics and environmental science. Researchers have found ways to upgrade these machines to produce more intense, focused, and consistent light beams that enable new, and more complex and detailed studies across a broad range of sample types. But some light-beam properties still exhibit fluctuations in performance that present challenges for certain experiments.

Image: This image shows the profile of an electron beam at Berkeley Lab’s Advanced Light Source synchrotron, represented as pixels measured by a charged coupled device (CCD) sensor. When stabilized by a machine-learning algorithm, the beam has a horizontal size dimension of 49 microns (root mean squared) and vertical size dimension of 48 microns (root mean squared). Demanding experiments require that the corresponding light-beam size be stable on time scales ranging from less than seconds to hours to ensure reliable data.
Credit: Lawrence Berkeley National Laboratory

Operando X-ray diffraction during laser 3D printing

Additive manufacturing, a bottom-up approach for manufacturing components layer by layer from a 3D computer model, plays a key role in the so-called “fourth” industrial revolution. Selective laser melting (SLM), one of the more mature additive manufacturing processes, uses a high power-density laser to selectively melt and fuse powders spread layer by layer. The method enables to build near full density functional parts and has viable economic benefits. Despite significant progress in recent years, the relationship between the many processing parameters and final microstructure is not well understood, which strongly limits the number of alloys that can be produced by SLM for commercial applications.

>Read more on the Swiss Light Source (PSI) website

Image: Rendered 3D model of the MiniSLM device.

First structure of a DNA crosslink repair ligase determined

Diamond’s Electron Bio-Imaging Facility (eBIC) has been used to generate the first 3D structure of the Fanconi anaemia (FA) core complex, a multi-subunit E3 ubiquitin ligase required for the repair of damaged DNA. The work, led by Dr Lori Passmore from the MRC Laboratory of Molecular Biology and a team of researchers, has been published today in Nature, and their research provides the molecular architecture of the FA core complex and new insights into how the complex functions.

The FA pathway senses and repairs DNA crosslinks that occur after exposure to chemicals including chemotherapeutic agents and alcohol, but also as a result of normal cellular metabolism. The megadalton FA core complex acts as an E3 ubiquitin ligase to initiate removal of these DNA crosslinks, helping to repair the damage caused. The research team used eBIC’s imaging facilities to make a major breakthrough in understanding the FA core complex by determining its structure using an integrative approach including cryo-electron microscopy and mass spectrometry.

Dr Peijun Zhang, Director of eBIC notes that:

Enabling cutting-edge research like this is exactly why we established eBIC, to provide scientists with state-of-the-art experimental equipment and expertise in the field of cryo-electron microscopy, for both single particle analysis and cryo-electron tomography. Determining the structure of the FA core complex for the first time is a fantastic achievement for the MRC research team.

>Read more on the Diamond Light Source website

Image: The FA core complex.
Credit: Phospho Biomedical Animation

Welcome back users!

This month marks the official start of user operation at CHESS and all three partner programs: The NSF funded CHEXS, as well as MacCHESS supported by NIH and NYSTAR, and the Materials Solutions Network at CHESS, or MSN-C, funded by the Air Force Research Lab (AFRL), all welcomed users to new hutches and beamlines. 

Louise Debefve stands outside a hutch on the experimental floor of the Cornell High Energy Synchrotron Source, CHESS. She is preparing the experimental equipment for some of the first data to be collected at CHESS since the completion of the CHESS-U upgrade. The platinum samples that she is about to study at the new beamlines will provide insights into the catalytic function of the element, enabling for example the generation of cleaner energy powering everything from cars to laptops.

But for now, Louise is happy to just be using the X-rays again, a familiar occurrence for the former graduate student, who spent years developing her research of catalysts through the use of X-rays at SSRL. As a postdoc at CHESS, Louise initially found herself right in the middle of the feverish construction of the upgrade, with no X-rays available for research.

>Read more on the CHESS website

Image: Louise Debefve, right, works with Chris Pollock and Ken Finkelstein at the new PIPOXS station.