Tag: 3D Imaging

Precise 3D imaging using dark-field X-ray microscopy under a structured illumination

Precise 3D imaging using dark-field X-ray microscopy under a structured illumination

Synchrotron X-ray tomography provides scientists a powerful tool for obtaining three-dimensional, high-resolution images of ordered materials. But successfully performing synchrotron tomography typically involves a complex and tedious process. For instance, the selected sample and its containment vessel must be rotated together in tiny incremental steps under a focused X-ray beam, over a full 360-degree rotation. And during this full rotation an extremely precise alignment between the crystalline lattice and rotational axis must be continuously maintained. Failure to meet this challenging protocol frequently introduces errors that seriously degrade the tomographic images.

In pursuit of a more efficient and reliable approach, a research team recently combined dark-field X-ray microscopy (DFXM) with a technique called structured illumination. This combination allows the sample and sample environment to remain stationary throughout the imaging process, resulting in quicker setup times, faster data collection, and a more robust path to achieving high-quality 3D images. The new imaging technique was performed on a pnictide superconductor at beamline 6-ID-C of the Advanced Photon Source (APS), a U.S. Department of Energy (DOE) Office of Science user facility at DOE’s Argonne National Laboratory.

The experimental results demonstrate the practicality of the less complex, yet still powerful, modified DFXM technique, opening up a new approach for scientists to obtain accurate 3D imaging at sub-micrometer resolutions.

3D imaging generally entails using some sort of rotation or translation. Medical CT scanners, for example, revolve an X-ray beam and detectors around a stationary patient. During each revolution the X-rays image a “slice” of the patient’s interior, and a computer then combines multiple slices to form a three-dimensional body image.

Synchrotron tomography reverses this process by fixing the X-ray beam’s direction, which then scans an incrementally rotating sample. Unfortunately, this arrangement introduces complexities that frequently lead to imaging errors. This is partly due to the sophisticated equipment that rotates with the sample, such as containment vessels for maintaining the sample at high or low temperatures, at extreme pressures, or within high magnetic fields. A servomotor then rotates both the sample and containment vessel, a complicated arrangement that not only requires long setup times but also provides multiple paths for mechanical deviations.

Read more on APS website

Tomography helps to provide insights into Aboriginal cultural belongings

Tomography helps to provide insights into Aboriginal cultural belongings

ANSTO is committed to using its infrastructure and expertise to work with Aboriginal communities and organisations to confirm the great antiquity of Aboriginal cultural heritage and assist with their preservation.

A number of sophisticated non-invasive nuclear and accelerator techniques were used to provide information about the origin and age of an Australian Aboriginal knife held in the collection of the Powerhouse Museum.

The knife with a striking highly polished resin handle was selected to be part of a 26-object exhibition, The Invisible Revealed held at the Powerhouse during 2021-2022.

Prior to the exhibition, the Powerhouse Museum wanted to determine the materials used in the construction of the knife and handle.

Powerhouse Museum First Nations Collections Coordinator, Tammi Gissell, explained that because little was known about the origin or use of the blade, it had to be handled with caution and following cultural protocols.

For this reason, the object was sent in a closed box to senior instrument scientist Dr Joseph Bevitt.

“Essentially, we had to answer these questions without looking at the object. The object was sent  to the Australian Synchrotron, where we used a 3D imaging technique, known as tomography, on the Imaging and Medical beamline (IMBL) to analyse it. The powerful X-ray can penetrate the box and the object to reveal important information about the materials,” explained Dr Bevitt.

The imaging was done by IMBL instrument scientist Dr Anton Maksimento and the data processed by Dr Bevitt.

“We could determine that the object was not made of metal but a very dense bone. Only two animals had bone that dense – the Australian cassowary and the water buffalo. As the museum told us it was found in northern Queensland, the source would have been the cassowary,” he added.

The next investigation used radiocarbon dating of the red Abrus seeds found on the handle.

Radiocarbon dates of the seeds from the Centre for Accelerator Science at ANSTO indicated  that they were most likely to have been harvested between 1877 and 1930— which may indicate the knife’s time of production.

Read more on the ANSTO website

Image: Image from the Imaging and Medical beamline at the Australian Synchrotron

Credit: ANSTO

Seeing more deeply into nanomaterials

Seeing more deeply into nanomaterials

New 3D imaging tool reveals engineered and self-assembled nanoparticle lattices with highest resolution yet—7nm—about 1/100,000 of the width of a human hair

From designing new biomaterials to novel photonic devices, new materials built through a process called bottom-up nanofabrication, or self-assembly, are opening up pathways to new technologies with properties tuned at the nanoscale. However, to fully unlock the potential of these new materials, researchers need to “see” into their tiny creations so that they can control the design and fabrication in order to enable the material’s desired properties.

This has been a complex challenge that researchers from the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Columbia University have overcome for the first time, imaging the inside of a novel material self-assembled from nanoparticles with seven nanometer resolution, about 1/100,000 of the width of a human hair. In a new paper published on April 7, 2022 in Science, the researchers showcase the power of their new high-resolution x-ray imaging technique to reveal the inner structure of the nanomaterial. 

The team designed the new nanomaterial using DNA as a programmable construction material, which enables them to create novel engineered materials for catalysis, optics, and extreme environments. During the creation process of these materials, the different building blocks made of DNA and nanoparticles shift into place on their own based on a defined “blueprint”—called a template—designed by the researchers. However, to image and exploit these tiny structures with x-rays, they needed to convert them into inorganic materials that could withstand x-rays while providing useful functionality. For the first time, the researchers could see the details, including the imperfections within their newly arranged nanomaterials.

Read more on the BNL website

Image: An artist’s impression of how the researchers used x-ray tomography as a magnifying lens to see into the inner structure of nanomaterials

Safely studying dangerous infections just got a lot easier

Safely studying dangerous infections just got a lot easier

An extremely fast new 3D imaging method can show how cells respond to infection and to possible treatments

To combat a pandemic, science needs to move quickly. With safe and effective vaccines now widely available and a handful of promising COVID-19 treatments coming soon, there’s no doubt that many aspects of biological research have been successfully accelerated in the past two years.

Now, researchers from Lawrence Berkeley National Laboratory (Berkeley Lab) and Heidelberg University in Germany have cranked up the speed of imaging infected cells using soft X-ray tomography, a microscopic imaging technique that can generate incredibly detailed, three-dimensional scans.

Their approach takes mere minutes to gather data that would require weeks of prep and analysis with other methods, giving scientists an easy way to quickly examine how our cells’ internal machinery responds to SARS-CoV-2, or other pathogens, as well as how the cells respond to drugs designed to treat the infection.

“Prior to our imaging technique, if one wanted to know what was going on inside a cell, and to learn what changes had occurred upon an infection, they’d have to go through the process of fixing, slicing, and staining the cells in order to analyze them by electron microscopy. With all the steps involved, it would take weeks to get the answer. We can do it in a day,” said project co-lead Carolyn Larabell, a Berkeley Lab faculty scientist in the Biosciences Area. “So, it really speeds up the process of examining cells, the consequences to infection, and the consequences of treating a patient with a drug that may or may not cure or prevent the disease.”

Taking cellular freeze frames

Larabell is a professor of anatomy at UC San Francisco and director of the National Center for X-Ray Tomography, a facility based at Berkeley Lab’s Advanced Light Source (ALS). The facility’s staff developed soft X-ray tomography (SXT) in the early 2000s to fill in the gaps left by other cellular imaging techniques. They currently offer the SXT to investigators worldwide and continue to refine the approach. As part of a study published in Cell Reports Methods late last year, she and three colleagues performed SXT on human lung cell samples prepared by their colleagues at Heidelberg University and the German Center for Infection Research.

Read more on the Berkeley Lab website

Image: Digital images of cells infected with SARS-CoV-2, created from soft X-ray tomography taken of chemically fixed cells at the Advanced Light Source

Credit: Loconte et al./Berkeley Lab