electron microscopy – Lightsources.org

New electron microscope centre to advance research into structural biology and new materials

2023/02/242023/03/03

This cutting-edge facility will house two high-end electron microscopes: one to determine the structure of large protein complexes and another to study materials at atomic level.
Created thanks to the joint effort of several research institutes, the centre is located at the ALBA Synchrotron and will be open to the entire scientific community.
Catalan Research and Universities Minister Joaquim Nadal inaugurated the centre, which has received funding from the Catalan Government’s ERDF programme, on 24 February.

The Joint Electron Microscopy Center at ALBA (JEMCA) was created thanks to the collaboration of different research entities to launch a new centre within the ALBA Synchrotron building offering electron microscope services to the scientific community. In specific, eight different partners will be using this centre: the Institute for Molecular Biology of Barcelona (IBMB-CSIC), the Catalan Institute for Nanoscienc and Nanotechnology (ICN2), the Institute for Biomedical Research (IRB Barcelona), the Centre for Genome Regulation (CRG), the Institute for Materials Science of Barcelona (ICMAB-CSIC), the Spanish National Research Council (CSIC), the Universitat Autònoma de Barcelona (UAB), and the ALBA Synchrotron. The project definition phase also included the fundamental support of the Barcelona Institute of Science and Technology (BIST).

This is the only facility in all of Spain that allows working with tools that are complementary to the synchrotron light source with the aim of gathering more information in the field of structural biology and materials science.

The centre currently houses two microscopes: the Cryo-TEM, coordinated by the Institute for Molecular Biology of Barcelona (IBMB-CSIC), and the METCAM, coordinated by the Catalan Institute for Nanoscience and Nanotechnology (ICN2).

The Cryo-TEM microscope is key to being able to solve rapidly and with high resolution the protein structures that cannot be analysed with other techniques. This microscope is already being put to use in experiments with an elevated social return. For example, IBMB-CSIC researchers Núria Verdaguer and Pablo Guerra, in collaboration with IRB Barcelona researchers Manuel Palacín and David Aparicio and the spin-off Ona Therapeutics, are analysing a protein involved in metastatic lung cancer as well as the protein’s complex with an antibody of interest for a therapy that targets metastases. The Cryo-TEM is the second microscope of its kind in Spain and represents a great advance for the user community in this field.

Read more on the ALBA website

Strong and resilient synthetic tendons produced from hydrogels

2021/03/162021/03/18

Human tissues exhibit a remarkable range of properties. A human heart consists mostly of muscle that cyclically expands and contracts over a lifetime. Skin is soft and pliable while also being resilient and tough. And our tendons are highly elastic and strong and capable of repeatedly stretching thousands of times per day. While limited success has been achieved in producing man-made materials that can mimic some of the properties of natural tissues (for instance polymers used as synthetic skin for wound repair) scientists have failed to create artificial materials that can match all the outstanding features of tendons and many other natural tissues. An international team of researchers has transformed a standard hydrogel into an artificial tendon with properties that meet and even surpass those of natural tendons. This new material was examined via electron microscopy and x-ray scattering to reveal the microscopic structures responsible for its outstanding features. The x-ray measurements were gathered at the U.S. Department of Energy’s (DOE’s) Advanced Photon Source (APS). The researchers have shown that their new hydrogel-based material can be modified to mimic a variety of human tissues and could also potentially be adapted to non-biological roles. Their results were published in the journal Nature.

Read more on the APS website

Image: Fig. 1. SEM images (left) showing the deformation of the mesh-like nanofibril network during stretching and corresponding in situ SAXS patterns (right). Scale bars, 1 μm (SEM images); 0.025 Å−1 (SAXS images)

Tracking attosecond wave packets with extreme ultraviolet pulses

2020/09/242020/09/24

The fastest dynamical process in atoms, molecules and complexes is the electronic motion. It occurs on time scales reaching down to the attosecond regime (1 as = 10^-18s). The advent of novel light sources, providing extreme ultraviolet (XUV) or even X-ray pulses with as pulse duration paves the way to study these dynamics in real-time. Therefore, researchers around the world are currently developing new spectroscopic techniques using pulses of XUV or X-ray radiation.

An international research collaboration from Germany, Italy, Sweden, Switzerland, Denmark and the local team at the FERMI free-electron laser, has succeeded in observing the ultrafast electronic wave-packet evolution induced by the coherent excitation of an electron out of an inner shell in argon atoms. The measured quantum interference pattern exhibits oscillations that have a period of only ≈ 150 as. In order to achieve this, the collaboration extended a spectroscopy technique known from the visible spectral range – coherent wave-packet interferometry – to the XUV regime. This required a so far unprecedented level of control over the phase and timing properties of free-electron laser pulse pairs, which was achieved by exploiting the coherence of the high-gain harmonic generation process at FERMI. This novel spectroscopy technique will provide substantial insights and real-time information about intra and inter particle decay mechanisms in the XUV range.

Read more on the Elettra website

Image: Artistic rendering of the electronic motion in the electronic shell of an atom, induced and probed by a double pulse sequence.

Single atoms can make more efficient catalysts

2019/01/072019/01/31

Detailed observations of iridium atoms at work could help make catalysts that drive chemical reactions smaller, cheaper and more efficient.

Catalysts are chemical matchmakers: They bring other chemicals close together, increasing the chance that they’ll react with each other and produce something people want, like fuel or fertilizer.

Since some of the best catalyst materials are also quite expensive, like the platinum in a car’s catalytic converter, scientists have been looking for ways to shrink the amount they have to use.

Now scientists have their first direct, detailed look at how a single atom catalyzes a chemical reaction. The reaction is the same one that strips poisonous carbon monoxide out of car exhaust, and individual atoms of iridium did the job up to 25 times more efficiently than the iridium nanoparticles containing 50 to 100 atoms that are used today.

>Read more on the SSRL at SLAC website

Image: Scientists used a combination of four techniques, represented here by four incoming beams, to reveal in unprecedented detail how a single atom of iridium catalyzes a chemical reaction.
Credit: Greg Stewart/SLAC National Accelerator Laboratory

Funds for the latest generation of electron cryomicroscopy

2018/11/062018/11/22

The Polish Ministry of Science and Higher Education handed over to SOLARIS the official decision to establish the National Cryo-EM Centre at the Polish partner facility, granting the requested financial support.

The successful application is the result of an agreement and cooperation of 17 leading scientific institutions in Poland in the area of structural biology. This very unique nation-wide consortium, led by Dr. Sebastian Glatt (the Malopolska Centre of Biotechnology, Jagiellonian University, Kraków) and Dr. hab. Marcin Nowotny (the International Institute of Molecular and Cell Biology, Warsaw), was not only key to bring this breakthrough research technique to Poland, but also exemplifies how scientists from around the country are able to work efficiently together for a greater common goal. This state-of-the-art microscope will allow its users to follow the progress of other international research centres and will transfer Polish and international scientists into the first class of structural biology.

The advances made in cryo-EM have revolutionized the field of structural biology over the last decade. The increased recognition of this technology has also culminated in the Chemistry Nobel Prize being awarded to its creators in 2017. The development of this technique has opened up new research horizons, which resulted in a long list of groundbreaking studies published in the most prestigious scientific journals. Foremost, the anticipated results are extremely relevant for a better understanding of the function of the human body, of the formation of human diseases and of processes like aging, and can lead to the development of new effective therapies. Structural biology has already contributed to a huge progress in the treatment of various human diseases, including cancer, Alzheimer’s disease and obesity. Last but not least, the presence of a high-end cryo-electron microscope at SOLARIS means that Krakow will attract national and international structural biologists.

>Read more on the SOLARIS website

Image: The image of mimivirus made with the use of a cryo-electron microscope.
Credit: Xiao C, Kuznetsov YG, Sun S, Hafenstein SL, Kostyuchenko VA, et al. (2009) [CC BY 2.5]

The microstructure of a parrotfish tooth contributes to its toughness

2018/02/082018/02/15

During a 2012 visit to the Great Barrier Reef off the coast of Australia, ALS staff scientist Matthew Marcus became intrigued with parrotfish. “I was reminded that this is a fish that crunches up coral all day and is responsible for much of the white sand on beaches,” Marcus said. “But how can this fish eat coral and not lose its teeth?” So Marcus teamed up with Pupa Gilbert, a biophysicist at the University of Wisconsin–Madison, and an international team of researchers she assembled, to understand how parrotfish teeth work.

Because conventional microscopes can overlook the unique orientation of crystals in tooth enamel, the team used the technique called polarization-dependent imaging contrast (PIC) mapping that Gilbert invented, which uses the photoemission electron microscopy (PEEM) Beamline 11.0.1 at the ALS. The PIC maps allowed them to visualize the orientation of individual crystals of fluorapatite, the main mineral component of parrotfish teeth.

Separate experiments used tomography (Beamline 8.3.2) and microdiffraction (Beamline 12.3.2) to further analyze the crystal orientations and strains in the teeth.

>Read more on the ALS website

Image: (extract) PIC maps acquired at the tips of four different parrotfish teeth show that they consist of 100-nm-wide, microns-long crystals, bundled into “fibers” interwoven like warp and weft fibers in fabric. These fibers gradually decrease in average diameter from 5 μm at the back of a tooth to 2 μm at the tip. Intriguingly, this decrease in size is spatially correlated with an increase in hardness and stiffness. The orientation angle of the crystals is color-coded (chart at bottom).