The gut-brain connection in Alzheimer’s unveiled with X-rays

2025/02/032025/02/10

Scientists led by the Institute of Nanotechnology in Italy, in collaboration with the ESRF, have discovered how X-ray micro- and nano- tomography can provide clues on the processes that link the gut neurons with those in the brain and may trigger Alzheimer’s. The results are out today in Science Advances.

Alzheimer’s disease, the most common type of dementia, is a neurodegenerative disorder characterized by brain alteration including synaptic loss, chronic inflammation and neuronal cell death.

In recent years, scientists have found evidence that the gut and the brain communicate through the neurons placed in both organs. Dysfunction in this axis has been linked to psychiatric and neurological disorders, including Alzheimer’s.

The gut microbiota, which refers to the microorganisms in the intestinal tract, plays a key role in human health and influences brain function, cognition and behaviour. “There are already many studies that support that changes in the gut composition can contribute to Alzheimer’s onset and progression”, explains Alessia Cedola, researcher from the Institute of Nanotechnology in Italy and corresponding author of the article.

In particular, dysbiosis, which is the process by which there is a loss of microbial diversity, induces the prevalence of dangerous bacteria producing toxic metabolites promoting inflammation, and, consequently, the breakage of the gut/brain barriers.

What happens exactly when gut dysbiosis occurs? “The main hypothesis is that changes trigger the escape of bad bacteria from the gut, entering the circulation, reaching the brain and triggering Alzheimer’s, but evidence is still poor”, adds Cedola.

Now scientists have discovered that nano- and micro X-ray phase-contrast tomography (XPCT) is a powerful tool to study structural and morphological alterations in the gut, without tissue manipulation. The team came to the ESRF to scan samples on beamline ID16A. “Thanks to this technique we can image soft biological tissues with excellent sensitivity in 3D, with minimal sample preparation and without contrast agents”, explains Peter Cloetens, scientist in charge of ID16A and co-author of the publication.

The data of the experiments, partially carried out at ANATOMIX at Soleil, showed the changes in cell abundance and organisation in the tissues, as well as structural alteration in different tissues of mice affected with Alzheimer’s. Specifically, it showed relevant alterations in the villi and crypts of the gut, cellular transformations in Paneth and goblet cells, along with the detection of telocytes, neurons, erythrocytes, and mucus secretion by goblet cells within the gut cavity. All these elements, when working correctly, maintain gut health, support digestion, and protect the intestinal lining from damage.

Image: Nano-XPCT 3D rendering of the longitudinal view of one crypt of SAMR1 mouse. The epithelial layer of the crypt has been rendered in green. The Paneth cells are colored in yellow and the goblet cells in blue. Scale bars, 5 μm.

Credit: A. Cedola

Scientists visualise crucial step in protein production in bacteria

2025/01/242025/01/27

Researchers have visualized for the first time how mRNA is delivered to the ribosome to begin production of proteins. They solved 9 of the structures using the ESRF’s cryo-EM. The results are published in Science.

Our DNA holds the instructions for making proteins, which are essential for the body to function. To use these instructions, a molecular machine called RNA polymerase (RNAP) copies the relevant section of DNA into a short-lived copy called messenger RNA (mRNA). This mRNA carries the instructions to another molecular machine, the ribosome. In bacteria, these two steps happen at the same time, allowing RNAP and the ribosome to cooperate and regulate each other.

A team led by Albert Weixlbaumer at the Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC) in Strasbourg, France, wanted to know how bacterial ribosomes are recruited to mRNAs, while they are still transcribed by RNAP. Using cryo-electron microscopy (cryo-EM), they studied complexes where an mRNA emerging from RNA polymerase (RNAP) was bound to the ribosome’s small subunit.

The team used cryo-EM at the ESRF and at IGBMC to visualize the ribosome-mRNA assemblies at molecular resolution. This enabled them to observe the process in great detail. The cryo-EM experiments at the ESRF provided the structure of 9 of the complexes studied. “Access to high-end cryo-EM instruments is absolutely essential and represents the culmination of our work. It is a real pleasure to work with the scientists at the ESRF, we always feel they are very dedicated to the projects they support and the data quality and amount of date we obtain could not be better”, explains Albert Weixlbaumer, leader of the team and researcher at the IGBMC.

Complementary single-molecule fluorescence co-localization experiments carried out in the lab of Nils Walter (University of Michigan, USA) and in vivo crosslinking followed by mass spectrometry carried out in the lab of Juri Rappsilber (Technical University Berlin, Germany) suggest RNAP and the ribosome cooperate to facilitate recruitment of the small ribosomal subunit to the mRNA.

Intricate machines

“Our research reveals how these molecules work like intricate machines. I am always amazed that it is possible to reconstitute such an intricate and biologically fundamental process in a tube in the laboratory,” says Michael Webster, now a group leader at the John Innes Centre in the UK and one of the lead authors of the study which was published in Science.

“It is particularly exciting to have the opportunity to use powerful imaging techniques to answer questions that researchers have been interested in for a long time,” he adds.

High-Power Laser Facility probes iron at the Earth’s core conditions

2025/01/202025/01/21

probe

Scientists have captured unprecedented detail of how iron behaves under extreme conditions approaching those of the core – advancing our understanding of planetary dynamics. Published in Physical Review Letters, these are the first experimental results from the new High-Power Laser Facility (HPLF) at the ESRF.

At the heart of our planet, Earth’s core comprises two distinct sections: a molten outer core that begins around 2,900 km beneath our feet, and a solid inner core starting around 5,150 km. Iron accounts for roughly 85% of the core by weight, combining with nickel and lighter elements to form alloys.

But uncertainties remain over the melting point of iron and its alloys under the extreme pressures of deep Earth. Debates also persist over how iron’s crystal structure may change with depth, which influences its physical and chemical properties at larger scales.

Shocked to the core

Fresh insights into these questions are revealed in new experimental work by Sofia Balugani, PhD student at the ESRF within the InnovaXN programme, in collaboration with the Ecole Polytechnique (LULI Laboratory, France), the First Light Fusion company (UK), and the HPLF team. The researchers “shocked” a tiny iron target (3.5 μm-thick) by firing it with a laser pulse, reaching a pressure of 240 GPa. By coupling the laser with X-rays, they recorded a bulk temperature measurement of 5,340K, the first of its kind for iron’s melting plateau under such extreme conditions. A melting point of 6200K was extrapolated for the even higher pressures of the inner core boundary (ICB).

“After three years of PhD research, this work fulfills my long-standing interest in planets, allowing me to study materials crucial to planets and their properties under extreme conditions, such as those on Earth,” says Balugani.

The research helps refine models of the Earth’s core’s behaviour. That’s because HPLF is optimised for this type of X-ray absorption experiment, which enabled the team to simultaneously track temperature alongside changes in the local order of iron. The findings rule out a transition in iron’s lattice structure to a high-temperature bcc (body-centred cubic) phase, which is observed in some other metals under shock compression such as copper and gold.

Instead, iron remains in the denser hcp (hexagonal close-packed) phase. The results may interest astrophysicists searching for exoplanets, given the importance of the core in generating a geomagnetic field and driving plate tectonics – both of which are key to supporting habitable conditions on Earth.

Image: The High-Power Laser Facility at the ESRF.

Credit: S. Candé.

Room-temperature serial crystallography experiments with microsecond pulsed beams

2025/01/132025/01/13

Scientists can now scan thousands of protein crystals at room temperature using X-ray microsecond pulses at the ESRF’s serial crystallography beamline, ID29. This capability is of utmost importance for time-resolved studies and drug discovery research at physiological conditions. The results are published in Communications Chemistry.

Studying macromolecular complexes at room temperature has always been challenging because of X-ray damage to the biological samples. Usually this is mitigated by collecting diffraction data at cryogenic conditions, but under these conditions functional dynamics are hindered.

Serial crystallography can provide an alternative way to collect data at physiological conditions with limited X-ray damage andto visualise functional dynamics that become untrapped. Serial femtosecond crystallography at X-ray free electron lasers (XFELs) allow scientists to decode macromolecular structures by acquiring data of tiny protein crystals at room temperature, outrunning the damage thanks to the extremely short pulses on the femtosecond. The transfer of the same technology to 3rd generation synchrotrons has been often limited to longer exposure time, flux and spatial resolution.

At the ESRF, thanks to the Extremely Brilliant Source, the ID29 beamline today has a flux density of ( > 1014 ph/s/µm2), three times higher than 3rd generation synchrotron sources. With this, scientists can deliver X-rays in very short pulses, on the microsecond time resolution, and at a very high repetition rate for macromolecular structure determination at room temperature.

Combined with a slightly polychromatic beam, this allows to measure complete reflections and ultimately accurate structure factor from thousands of microcrystals, even from low redundant datasets. This combination minimizes the sample consumption down to only a few microliters of crystal slurry, in contrast to larger amounts that are frequently needed for serial experiments, and allows complete data to be collected in the fraction of the time.

“Our beamline is the first in the world at a high energy 4th generation synchrotron which is designed to use the high flux density to study macromolecules at room temperature, with a microsecond time resolution”, explains Daniele de Sanctis, scientist in charge of ID29 together with Shibom Basu, EMBL scientist. “The technique, called serial microsecond crystallography (SµX), allows researchers to use less sample to achieve comprehensive structural detail of proteins under physiological conditions and also to visualise molecular movies in action on this time domain. Our work initiates a new future of time-resolved serial microsecond crystallography experiments at 4th generation storage rings, that will ultimately complement X-ray free electron laser (XFEL) experiments.”

A versatile sample environment

One specificity of serial crystallography is the set-up. How do scientists deliver a slurry of hundreds to thousands of microcrystals to the beam? This is a constantly evolving field and ID29 can accommodate different kinds of sample delivery methods with its flexible setup. The researchers applied the unique beam of ID29 to different sample delivery methods: fixed target (foils and chips) and three different types of high viscosity extruders demonstrating how structures obtained do not present any evident sign of radiation damage. The data quality obtained allows to unambiguously identify the electron density map of ligated molecules.

Image: Daniele De Sanctis, scientist in charge of the ESRF, and Shibom Basu, from the EMBL, on the beamline.

Credit: S. Candé.

Thin ceramics make strong piezoelectrics

2025/01/082025/01/10

Scientists from India and Australia have shown how to boost the electro-mechanical response of piezoelectrics made from ceramics. Published in Nature, their work reveals that the thinness of the ceramics is key to bringing the performance in line with expensive single-crystal ferroelectrics.

Piezoelectrics are materials that deform in response to an electric field. They are important in all sorts of industrial and consumer devices, typically acting as sensors, fine actuators and sound generators. Generally speaking, the bigger the piezoelectric response, the better.

Some of the biggest responses are found in ferroelectrics – that is, materials with a permanent electric polarization – in single crystal form, but these take a lot of time and energy to synthesise. On the other hand, ceramics can easily be processed on a large scale. These are brittle materials composed of many crystal grains, but usually they have less than two-fifths of the piezoelectric response of their counterparts made of single-crystal ferroelectrics.

Groups led by Rajeev Ranjan at the Indian Institute of Science in Bangalore, and John Daniels at the University of New South Wales in Sydney, have been investigating whether the piezoelectric response in ceramics might be limited by the “clamping” of individual crystal grains by their neighbours. If so, then a thinner ceramic ought to perform better, as a bigger portion of its grains would be at the material’s surfaces, where there are fewer neighbouring grains constraining it and therefore, theoretically, more freedom. “What we didn’t know is how deep from the surface the grains can still feel relatively free,” says Ranjan.

To answer that question, they had to come to the ID15A beamline at the ESRF. Here, armed with discs 0.2 to 1 mm thick of a range of ceramic compositions, they could perform high-energy X-ray diffraction to chart the movement of grains at variable depth as they applied an electric field and measured the subsequent deformation, in situ. Observing these dynamics at micron resolution relied on the quality of the focusing optics and the mechanical sample positioning. “High energy x-rays with a planar beam geometry of about 1 x 100 µm2 were necessary to have the depth resolution and sufficient grain sampling. The source and optics of ID15A allowed this unique combination,” says Daniels.

To the researchers’ surprise, the crystal grains were relatively free even 0.1 mm below the surface. This explained why the discs that were just 0.2 mm thick deformed by as much as 1% in that axis – a threefold improvement on 0.7 mm discs, and comparable to deformations found in expensive single-crystal ferroelectrics. “This is a revelation in the piezoceramic community,” says Ranjan.

New detoxification pathway for mercury in penguins

2024/12/112024/12/11

An international team of scientists led by the ESRF has found that emperor penguins detoxify mercury with both sulphur and selenium, a new pathway for a marine predator. This new detoxification pathway for mercury has been unveiled in a study published in the Journal of Hazardous Materials.

Mercury is considered by WHO as one of the top ten chemicals of major public health concern. Mercury bioaccumulates in organisms along time and biomagnifies in aquatic and terrestrial food webs as the neurotoxic form of methylmercury. Understanding the internal detoxification processes of methylmercury in animals is essential for protecting wildlife and designing treatments against mercury poisoning.

Alain Manceau, ESRF scientist and researcher emeritus at the CNRS, together with his collaborators from the University of La Rochelle and the CNRS (LIENSs and CEBC), the United States Geological Survey, and the University of California Davis, has been studying how animals detoxify mercury for years.

Back in 2021, they unveiled that apex predators, such as seabirds like giant petrels, and marine mammals like pilot whales, detoxify methylmercury through a sequence of reactions involving reduced selenium in the form of a prominent selenoprotein. Since mercury is ultimately detoxified as nontoxic mercury selenide, it has diminished toxicological consequences as long as there is sufficient selenium, because mercury selenide is chemically inert.

“We knew the mechanism that animals that are exposed to large quantities of mercury use; now we wanted to find out what happens with animals that are lower in the food chain, such as penguins”, Manceau explains. Emperor penguins feed mostly on Antarctic silver fish and squid, which contain methylmercury, albeit not in large quantities. Because of this, penguins are less contaminated with mercury than toothed whales, giant petrels, and other predators higher in the food web.

The scientists, who used X-ray absorption spectroscopy, identified, for the first time, a second demethylation pathway of toxic methylmercury. In Emperor penguins, the toxic mercury is partially detoxified using the same chemical pathway as giant petrels, but theses penguins have also developed a second mechanism whereby their body forms a Hg-dithiolate complex. This complex binds to cysteine amino acids in enzymes, altering their function. This demethylation pathway had never been observed before in animals, only in bacteria.

Image: A baby penguin.

Credit: Yves Cherel.

Scientists visualise the paths controlling heart performance

2024/12/062024/12/10

Scientists have found the role of two proteins in the functioning of the heart. The results could help better design targeted strategies to treat certain cardiomyopathies. The results are out in PNAS.

The heart works using tiny muscle filaments, and two main steps control how they interact: first calcium signals cause changes in the thin filament (actin), allowing it to connect with myosin motors. Then myosin motors on the thick filament switch from “off” (inactive) to “on” (active), so they can pull on actin and create force and shortening. The thick filament can sense how much force is needed and adjust how many motors to turn on, but scientists are still figuring out exactly how this works.

Cardiomyopathies take place when these mechanisms regulating the contraction-relaxation cycle of the heart malfunction. This is due to mutations in the contractile proteins (myosin and actin) but also in accessory proteins (Myosin-binding protein-C and titin). Broadly, MyBP-C and titin ensure together that the heart contracts effectively while maintaining responsiveness to changes in demand.

A team from the University of Firenze (Italy) used small-angle X-ray diffraction at the ESRF’s ID02 beamline back in 2017 and showed that, during muscle contraction, myosin motors move outward from the thick filament, enabling interaction with actin based on the load, which in the cardiac ventricle is the arterial pressure against which blood must be pumped (Reconditi et al. PNAS 2017). Evidence from other laboratories also suggested that thick filament activation is modulated by regulatory domains in the myosin motor itself and by accessory proteins like MyBP-C and titin. However, their specific function in cardiac performance was not known in detail.

Now the same team has found the role that MyBP-C and titin play in the functioning of the heart, at beamline ID02. “The beamline ID02 is ideal thanks to its camera length, so we can have the detector closer or further to the samples in a range from 0.5 to 31 m. This lets us explore the contractile proteins as well as the sarcomere, the unit cell of muscle, which is crucial for our research”, says Massimo Reconditi, scientist at the University of Firenze and corresponding author of the paper. “With EBS, thanks to its low divergence, we can observe on the same diffraction pattern a high number of reflections together with their fine structure”, he adds.

Image: Theyencheri Narayanan, scientist in charge of ID02, on the beamline.

Credit: S. Candé.

Scientists reveal pore formation dynamics in copper laser welding

2024/11/262024/11/29

Scientists from academia and industry have identified four ways in which pores form in copper laser welding, thanks to in-situ X-ray imaging experiments at the ESRF combined with multi-physics simulation. The results provide clues for optimisation of the manufacturing of copper components through this method. The results are out in the International Journal of Machine Tools and Manufacture.

Copper is widely used for components in electric vehicles, energy storage or electronic devices because of it is excellent electrical and thermal conductivity. However, these same properties—high thermal conductivity and low infrared light absorption—pose challenges for traditional welding techniques, often leading to inconsistent results or defects.

The technique of laser beam welding overcomes some of these difficulties by delivering high-intensity, focused energy that rapidly heats and melts copper, enabling deep, narrow welds with minimal heat-affected zones. Its high processing speed and ability to be finely tuned for different material thicknesses and conditions make it ideal for modern manufacturing demands.

However, defects such as pores still happen, especially microscopic pores. Now scientists led by Technische Universität Ilmenau and TU Wien, and with the collaboration of the company COHERENT, leader in laser solutions and photonics technologies, and the ESRF, have unveiled the dynamics behind pore formation.

The findings show that pore formation is driven by four different mechanisms: bulging, spiking, upwelling waves at the keyhole rear wall and melt pool ejections. In particular, bulging takes place at the rear keyhole wall due to dynamic melt flow; spiking occurs when rapid keyhole penetration causes detachment and solidification at the tip; pores travel due to chaotic vapor flows and bulges in the melt pool and finally, depression pores are linked to melt pool ejection and dynamic keyhole pressure.

A special laser beam shape, called a concentric core-ring profile, was also analysed and found to help make the welding process more stable and reduce defects like pores.

The team used high-speed synchrotron X-ray imaging at beamline ID19, where they acquired 20,000 images per second to identify the processes in pore formation during laser beam welding.

The experiment was very challenging, with 12 engineers to install the laser welding instrument, which contained two lasers and an ESRF in-house developed gas nozzle. Alexander Rack, scientist in charge of the beamline ID19, explains the complexity of the set-up: “This is among the most demanding experiments done so far: we had to install dedicated power lines to feed the big laser needed for welding. Experiments with sample environments are core expertise of ESRF, and thanks to our experience with complex set-ups such as furnaces, gas launchers or high-pressure cells; we are perfectly adapted for this study”. He adds: “The white undulator light with the new EBS is bright enough to shine light through 3 mm of steel while welding, and we were able to take high-speed X-ray movies with microseconds exposure time”.

They then compared these results with multi-physics modeling simulations. This physics-based model, closely aligned with experimental data, allows researchers to validate elusive phenomena with unprecedented accuracy.

Image: Leander Schmidt, from Technische Universität Ilmenau, during the experiment on ID19.

Credit: S. Candé.

The secrets of fossil teeth

2024/11/132024/11/13

Compared to the great apes, humans have an exceptionally long childhood, during which parents, grandparents and other adults contribute to their physical and cognitive development. This is a key developmental period for acquiring all the cognitive skills needed in the complex social environment of a human group. The current consensus is that the very long growth of modern humans has evolved as a consequence of the increase in brain volume, since such an organ requires significant energy resources to grow.

However, the ‘big brain – long childhood’ hypothesis may need to be revised, as shown by an international team of researchers in the journal Nature, based on an analysis of the dental growth of an exceptional fossil.

The research team, made up of scientists from the University of Zurich (Switzerland), the ESRF and the Georgian National Museum (Georgia), used synchrotron imaging to study the dental development of a near-adult fossil of early Homo from the Dmanisi site in Georgia, dated to around 1.77 million years ago.

Teeth are the key

“Childhood and cognition do not fossilise, so we have to rely on indirect information. Teeth are ideal because they fossilise well and produce daily rings, in the same way that trees produce annual rings, which record their development”, explains Christoph Zollikofer from the University of Zurich and first author of the publication. “Dental development is strongly correlated with the development of the rest of the body, including brain development. Access to the details of a fossil hominid’s dental growth therefore provides a great deal of information about its general growth”, adds Paul Tafforeau, scientist at the ESRF and co- author of the study.

18 years of research

The project was launched in 2005, following the initial success of non-destructive analyses of dental microstructures using phase contrast synchrotron tomography at the ESRF. This technique enabled scientists to create virtual microscopic slices through the teeth of this fossil. The exceptional quality of preservation of the growth structures in this specimen has made it possible to reconstruct all the phases of its dental growth, from birth to death, with unprecedented precision. In a way, the scientists have virtually regrown the teeth of this hominid.

This project took almost 18 years from its initial conception in 2005 to the finalisation of the results in 2023. The scientists scanned the teeth for the first time in 2006, and the first results on the fossil’s age at death were obtained in 2007. “We expected to find either dental development typical of early hominids, close to that of the great apes, or dental development close to that of modern humans. When we obtained the first results, we couldn’t believe what we saw, because it was something different that implied faster molar crown growth than in any other fossil hominin or living great ape”, explains Paul Tafforeau.

Over the following few years, five series of experiments and four complete analyses using different approaches were carried out as technical advances were made in dental synchrotron imaging. With the results all pointing in the same direction, and potentially having a strong impact on the ‘big brain – long childhood’ hypothesis, the scientists had to think outside the box to understand this fossil. “It’s been a slow maturation, both technically and intellectually, to finally arrive at the hypothesis we are publishing today”

A new extinct species of coelacanth discovered thanks to the ESRF

2024/11/122024/11/15

Scientists from the Natural History Museum (MHNG) and the University of Geneva (UNIGE) have discovered a new species of coelacanth, a fish considered to be a living fossil that only had two species known until now. This finding was possible thanks to the experiments done at the ESRF. The work is out in the journal PlosOne.

Fossilisation is a process that allows the preservation of plants and animals in rocks for
hundreds of millions of years. During this period, geological upheavals often deteriorate
fossils and paleontologists put great deal of effort and imagination into reconstructing
organisms as they were when they were alive.

A team of paleontologists from the MHNG and UNIGE, in collaboration with researchers from the Senckenberg Research Institute, Natural History Museum in Frankfurt am Main (Germany) and the ESRF, have just published a paper that shows the discovery of some 240-million-year-old coelacanth fossils, which show extremely detailed characteristics of of their preserved skeleton that had never been observed before.

Coelacanths are fish of which there are only two current species and which, with a few
exceptions, evolved slowly over more than 400 million years. The fossils studied by
the international team were discovered in clay nodules from the Middle Triassic period in Lorraine (France), near Saverne. The specimens, about fifteen centimetres long, are
preserved in three dimensions.

Some specimens were analysed at the ESRF in Grenoble. After hundreds of hours of work consisting of virtually individualising the bones of the skeleton by computer, the team obtained virtual 3D models of the fossils that can be easily studied.

The results enabled the team to reconstruct the skeleton of these fish with a level of detail never obtained before for this type of fossil.

Trapping and storing carbon dioxide underground

2024/11/062024/11/14

A team led by the University of Oslo in Norway, in collaboration with the University of Maryland in USA, is investigating how to massively store carbon dioxide (CO2) underground by copying nature. Through a chemical reaction, carbon dioxide can be trapped naturally inside the Earth’s subsurface and stored as solid minerals, called carbonates. The researchers are now carrying out experiments at the ESRF with the aim to accelerate such a process.

Carbon dioxide levels in the atmosphere are higher than ever, mainly due to the burning of fossil fuels and other anthropogenic activities. This, in turn, increases global temperatures and impacts sea levels and the ocean ecosystems.

A potential solution to this crisis would be to trap and store CO₂ underground as solid minerals, which is a natural process that occurs over long periods thanks to the reaction of CO₂ with rocks in the Earth’s crust and mantle.

Scientists have been studying the injection of CO₂in the subsurface for years. For example, in Sleipner, in the North Sea, millions of tons of carbon dioxide have been injected into a sandstone geological reservoir in the past fifteen years, where CO₂ is stored in liquid form. CO₂ can also be stored in solid form through mineralization processes, minimising the risk of leakage. Small-scale ongoing projects, such as Carbfix in Iceland, show promising results but questions of efficiency remain.

“The natural process is very effective but too slow, so we wonder whether we could somehow accelerate it so that large quantities of CO₂ could be injected underground, without leakage”, explains François Renard, director of the Njord Centre at the University of Oslo and ESRF user.

The natural process

Atmospheric CO₂ and water from precipitations naturally react with rocks present at the Earth’s surface – this process is called weathering. Some of these rocks have been produced by volcanic activity (basalts in Iceland) or were exhumed to the Earth’s surface from the mantle (peridotites). When reacting with CO₂ and water, they may dissolve partially over geological time scales, liberating magnesium, iron, and calcium ions that can bind with carbon dioxide, in a process called mineral carbonation, which converts CO₂ into minerals. The end product is a calcium, iron or magnesium carbonate, which are stable minerals that effectively trap carbon dioxide into a solid form.

Renard and his team are focusing on storing CO₂ in basaltic and peridotite rocks, rich in magnesium and calcium, as they are the most efficient environments for it due to their high reactivity. They make up about 70% of the Earth’s surface and are responsible for 1/3 of the trapping of CO₂ from the atmosphere through weathering. Estimates suggest that mid-ocean ridges worldwide can store up to 100,000 Gt of CO₂. This is more than 2000 times the annual global emissions of CO₂.

Once in the basaltic or peridotite rocks, the CO₂ quickly reacts with the divalent cations (Ca²⁺, Mg²⁺, and Fe²⁺) from dissolving minerals in the rock and form carbonate minerals. In comparison, it might take several tens of thousands of years for significant amounts of CO₂ to mineralize in a sandstone reservoir. After it becomes a mineral, the carbon will not move over geological timescales.

Carbonation at the ESRF

The team is focused on studying how basalts and peridotites can host large quantities of flows of carbon dioxide mixed with water, which will react with the rock to produce carbonate minerals.

TexTOM: bringing crystallographic texture analysis to the third dimension

2024/10/152024/10/23

Texture tomography (TexTOM) is a cutting-edge 3D crystallographic texture-analysis tool for polycrystalline materials, now available at beamlines ID13 and ID15A, with future expansions planned for additional beamlines. TexTOM offers rapid, quantitative texture analysis with enhanced spatial resolution, making it ideal for complex materials like biominerals, deformed metals, and technical alloys. This technique enables in-situ and operando studies, expanding the possibilities for real-time texture investigations.

Crystallographic texture plays a crucial role in determining the mechanical, electronic, magnetic, and optical properties of polycrystalline materials. Existing techniques, such as 3D X-ray diffraction (3DXRD) [1] and dark-field X-ray microscopy [2], are effective for analyzing well-aligned, narrow structures in technical materials. However, they are limited in their ability to provide comprehensive quantitative texture information in 3D analysis for broader more complex textures, which are typically found in biomaterials, biominerals, or deformed technical materials.

While wide-angle X-ray scattering (WAXS) tensor tomography [3] (derived from small-angle X-ray scattering tensor tomography [4,5,6]) has facilitated more detailed 3D orientation analysis, it lacks a fully quantitative approach due to its reliance on a reciprocal space model of single Bragg reflections. In contrast, typical diffraction patterns contain multiple crystalline reflections, whose intensity and distribution offer valuable additional information.

TexTOM is a new tool developed by Tilman Grünewald’s group at the Institut Fresnel, Marseille, in collaboration with beamlines ID13 and ID15A, designed to fill the gap in 3D crystallographic texture analysis. The technique utilizes a hyperspherical harmonics [7] approach to model local orientation distribution functions (ODF), enabling the description of crystallographic texture in 3D. By incorporating prior knowledge of crystal symmetry, TexTOM reduces the data required compared to WAXS tensor tomography, thereby accelerating the measurement process and minimizing sample exposure.

Image: Fig. 1: Texture tomography (TexTOM). a) Data collection involves raster-scanning a sample through a focused X-ray beam at multiple rotation and tilt angles, capturing a 2D diffraction pattern at each scan point. b) Selected diffractlets form the basis for structural reconstruction. c) Successful reconstruction of a silica biomorph, where a full orientation distribution is determined for each voxel, allowing detailed analysis.

EBS flux reveals fate of over-compressed water

2024/10/012024/10/07

ESRF users have exploited the high X-ray flux of the EBS to confirm that water freezes into a particular ‘cubic’ form of ice when it is compressed very quickly. Published in Nature Communications, the results clear up a long-standing mystery in high-pressure physics, and will provide insights into the composition of the Solar System’s icy moons.

Water is so familiar to us that the ancients considered it one of the four basic elements. To modern physicists, however, it is a marvel – a liquid that, unlike almost all others, becomes not easier but harder to solidify at high pressures and, when it does solidify, expands rather than contracts. The behaviour results from the way the constituent hydrogen atoms bond with one another, and is vital for life. Without it, lakes and seas would freeze from the bottom up, killing everything inside.

In fact, the freezing of water is even more complicated than this. Under various pressures and temperatures, water is known to form at least 19 distinct phases of ice. The one we know well on Earth has its oxygen and hydrogen atoms in hexagonal rings. On the other hand, the most common phase in the Universe is likely to be a type of low-density amorphous ice, without any long-range crystal structure at all. Another very common phase with big scientific interest is the cubic-bonded ice VII, which is stable over a vast pressure range from 2 to 80 gigapascals, equivalent to those present on icy planets and moons.

The gateway to ice VII may be higher pressures, but the speed of compression is critical. Take it slowly, and normal water freezes at about one gigapascal into ice VI, a tetrahedral phase, before forming ice VII at about 2 gigapascals. Go faster, though, and the freezing is waylaid, occurring at higher and higher pressures.

Until now, no-one has been sure what water ultimately freezes into when it is compressed very quickly. The answer is important, because the freezing of water on other planets and moons could have taken place when it was over-compressed during planetary impact.

Charles Pépin, Paul Loubeyre and colleagues at the CEA Laboratory for Materials at Extreme Conditions at the Université Paris-Saclay in France, together with scientists at the ESRF in France and the Paul Scherrer Institute (PSI) in Switzerland, have finally solved the mystery using a range of cutting-edge instrumentation for time-resolved X-ray diffraction.

One part of the toolkit was a special “dynamic-piezo” diamond anvil cell (d-DAC), designed by the CEA team to compress water in a well-controlled manner. Another was the latest Jungfrau detector – the result of a joint PSI–ESRF development – which can record an X-ray image every few microseconds. Most importantly, however, was the extremely high flux of X-rays streaming through the ID09 beamline, provided by the EBS.

30 years of ESRF users: Pioneering science

2024/10/012024/10/01

On this 1st October the ESRF celebrates 30 years of science and user operation. When the ESRF officially opened its doors to users in 1994, it offered 15 state-of-the-art beamlines and capabilities based on a state-of-the-art synchrotron source. Three decades later, and with a record of discoveries in its history, the ESRF enters a new era of scientific possibilities with EBS.

Thirty years ago, just one day after its official inauguration on 30 September 1994, the first users came to the ESRF to begin their experiments. Since then, the ESRF has contributed to over 40,000 publications and four Nobel Prizes, driving the frontiers of science across numerous fields.

Among the first users was Jean Daillant, the new ESRF director general. “When I first came as a user to the ESRF, back in 1994, it was a unique place to carry out experiments we could only have imagined before, and this experience definitely shaped my career”, explains Daillant.

During these three decades, the ESRF users have been coming onsite with ever more complex scientific questions to answer, while the scientists, engineers and technicians in-house have made use of their creativity to implement the best set-ups to achieve what one day seemed unachievable.

Long-term user and former member of the Science Advisory Committee Moshe Deutsch, professor at Bar-Ilan University (Israel), explains the importance of this collaboration: “Suggestions coming from the users to the beamline scientists and up to the committees and management, i.e. bottom up, along with the combined expertise of the users and the staff, are, and have always been at the ESRF, the seeds of new directions for science, for instrumentation and for beamlines”.

The number of proposals throughout these years has increased exponentially: In 1995, there were 792 proposals. In 2024, there were a total of 2200. Joanne McCarthy, head of the User Office, explains how the beamtime proposals have become more sophisticated: “Today scientists need to get a full picture of a scientific question, and thanks to EBS and the different access modes, there is an increasing number of proposals that include experiments using complementary techniques and with teams including different expertise”. An example of this is the Human Organ Atlas Hub, where interdisciplinary groups made of doctors, physicists and engineers join forces to provide unprecedented insights into our bodies in health, ageing and disease.

Pioneering research

Back in 1994, the ESRF was one of the very first 3rd generation synchrotrons and could provide higher flux than previously built machines, which allowed several fields to really take off.

One of the clearest examples is structural biology, which was already popular in the early days (1/3 of the proposals submitted), leading to several Nobel Prize laureates from the user community.

Throughout the years, cryo macromolecular crystallography became a key success of structural biology, but a significant limitation is that the crystals were not in their natural environment. Today, thanks to EBS, the ESRF offers room-temperature serial crystallography, which enables the capture of crystal structures in conformations closer to ‘native’ conditions, allowing scientists to follow reactions in real-time. These new capabilities are very relevant for the design of new drugs and biotechnological applications.

Another field where the ESRF was a pioneer is paleontology. The first experiments were carried out in the year 2000 by Paul Tafforeau, PhD student at the time, when José Baruchel, in charge of the X-ray microtomography beamline, gave him the chance to scan some fossil teeth. “Until then I had used destructive methods, which are not convenient for unique specimens like fossils”, explains Tafforeau, who is now in charge of BM18. “Every time I had beamtime it felt like a whole new world opened up”.

The ESRF soon became the referent for research in paleontology, where the oldest sample scanned are 2.8 billion year old bacteria. In the beginning, the sizes of the samples were no more than 1-2 cm, which increased to 16cm when the first scan of a hominid brain took place. Today, with the new BM18 and the EBS higher coherence and energy than previously, paleontologists will be able to scan 250 cm tall samples weighing around 300kg.

Mechanism behind the enormous density increase in highly-compressed liquid water

2024/09/172024/09/17

Researchers reveal details behind the microscopic mechanism that enables the large increase of density in compressed water using experimental data from the ESRF and first principles simulations.

Water is one of the most ubiquitous substances and essential for all forms of life on Earth. Its many thermodynamic anomalies render water one of the most extraordinary liquids known to mankind. Yet, after decades of intense research, the structural details at atomic length scales underlying these anomalies remain unclear.

An example of the strange behaviour of water is its density, which is highest at 4 C. This heavily affects water’s buoyancy and impacts ocean circulation and climate patterns. Likewise, water’s low density ice phase, common ice Ih, is less dense than liquid water, a fact that is vital for aquatic life and the stability of our ecosystems. Pressure is one of the fundamental experimental parameters and is often used by researchers to observe a system’s respond to it, yielding invaluable information about the interactions between atoms and molecules at play.

Now an international team of scientists lead by the ESRF have studied pressurized water in its liquid state at atomic length scales. “There is still a lot of controversy as to how hydrogen bonding between water molecules evolves under pressure, so our study aimed to shed light on this question”, explains Christoph Sahle, scientist in charge of beamline ID20 and co-corresponding author of the publication.

Jean Daillant starts as new DG of the ESRF

2024/09/022024/09/10

As the ESRF celebrates 30 years of science, the European synchrotron welcomes a new Director General: Jean Daillant. Appointed by the ESRF International Council, which brings together the 20 ESRF partner countries, Jean Daillant took up his new role of DG on 1st September.

Jean Daillant is a widely recognised expert on synchrotron radiation. A soft matter physicist, his expertise focuses on soft matter physics and liquid interface dynamics, delving into their intermolecular interactions and surface phenomena. Utilising advanced techniques like synchrotron X-ray and atomic force microscopy, he has analysed these systems at the nanoscale. His interest also extends to practical applications, particularly in nanomaterials synthesis through self-assembly.

Jean Daillant was Director General of the SOLEIL synchrotron over the last thirteen years, during which time it has become a leading facility among the medium-energy synchrotron radiation sources. After serving as Chair, he is now Vice-Chair of LEAPs, the League of European Accelerator-based Photon Sources, which aims to promote scientific excellence and strengthen the cooperation between synchrotron and X-ray free electron laser facilities to support an innovative and sustainable European Research Area.

He was a member of the ESRF Science Advisory Committee over the period 2003-2009 and headed SOLEIL’s Scientific Council between 2006 and 2010. After graduating in Physics at the École Normale Supérieure de St-Cloud, he joined the CEA in 1989, where he subsequently became Head of the Soft Matter and Interfaces Group before becoming joint director of LURE, the French national synchrotron light source in Orsay, from 1999 to 2003. In 2004, he became Head of the CEA-CNRS Laboratory LIONS for Interdisciplinary Research on Nanometric and Supramolecular Organisation, until 2011, at which time he took up the role of Director General at SOLEIL.

“The ESRF can be happy that in Jean Daillant we have a new Director General that brings both the science perspective of a user and, as the previous DG of SOLEIL, the strategic and management views that are needed to fully exploit the EBS”, says Elias Vlieg, chair of the ESRF Council. “The Council is looking forward to a fruitful collaboration with him and the other members of the management team in the coming years.”