Category: 7. Science

For the first time, a research team at the University of Minnesota Twin Cities demonstrated a groundbreaking process that combines 3D printing, stem cell biology, and lab-grown tissues for spinal cord injury recovery. 

The study was recently published in Advanced Healthcare Materials, a peer-reviewed scientific journal.

According to the National Spinal Cord Injury Statistical Center, more than 300,000 people in the United States suffer from spinal cord injuries, yet there is no way to completely reverse the damage and paralysis from the injury. A major challenge is the death of nerve cells and the inability for nerve fibers to regrow across the injury site. This new research tackles this problem head-on.

The method involves creating a unique 3D-printed framework for lab-grown organs, called an organoid scaffold, with microscopic channels. These channels are then populated with regionally specific spinal neural progenitor cells (sNPCs), which are cells derived from human adult stem cells that have the capacity to divide and differentiate into specific types of mature cells.

“We use the 3D printed channels of the scaffold to direct the growth of the stem cells, which ensures the new nerve fibers grow in the desired way,” said Guebum Han, a former University of Minnesota mechanical engineering postdoctoral researcher and first author on the paper who currently works at Intel Corporation. “This method creates a relay system that when placed in the spinal cord bypasses the damaged area.”

In their study, the researchers transplanted these scaffolds into rats with spinal cords that were completely severed. The cells successfully differentiated into neurons and extended their nerve fibers in both directions-rostral (toward the head) and caudal (toward the tail)-to form new connections with the host’s existing nerve circuits. 

The new nerve cells integrated seamlessly into the host spinal cord tissue over time, leading to significant functional recovery in the rats.

Regenerative medicine has brought about a new era in spinal cord injury research. Our laboratory is excited to explore the future potential of our ‘mini spinal cords’ for clinical translation.”

Ann Parr, professor of neurosurgery, University of Minnesota

While the research is in its beginning stages, it offers a new avenue of hope for those with spinal cord injuries. The team hopes to scale up production and continue developing this combination of technologies for future clinical applications.

In addition to Han and Parr, the team included Hyunjun Kim and Michael McAlpine from the University of Minnesota Department of Mechanical Engineering; Nicolas S. Lavoie, Nandadevi Patil and Olivia G. Korenfeld from the University of Minnesota Department of Neurosurgery; Manuel Esguerra from the University of Minnesota Department of Neuroscience; and Daeha Joung from the Department of Physics at Virginia Commonwealth University.

This work was funded by the National Institutes of Health, the State of Minnesota Spinal Cord Injury and Traumatic Brain Injury Research Grant Program and the Spinal Cord Society.

Optical microscopy is a key technique for understanding dynamic biological processes in cells, but observing these high-speed cellular dynamics accurately, at high spatial resolution, has long been a formidable task.

Now, in an article published in Light: Science & Applications, researchers from The University of Osaka, together with collaborating institutions, have unveiled a cryo-optical microscopy technique that take a high-resolution, quantitatively accurate snapshot at a precisely selected timepoint in dynamic cellular activity.

Capturing fast dynamic cellular events with spatial detail and quantifiability has been a major challenge owing to a fundamental trade-off between temporal resolution and the ‘photon budget’, that is, how much light can be collected for the image. With limited photons and only dim, noisy images, important features in both space and time become lost in the noise.

Instead of chasing speed in imaging, we decided to freeze the entire scene. We developed a special sample-freezing chamber to combine the advantages of live-cell and cryo-fixation microscopy. By rapidly freezing live cells under the optical microscope, we could observe a frozen snapshot of the cellular dynamics at high resolutions.”

Kosuke Tsuji, one of the lead authors

For instance, the team froze calcium ion wave propagation in live heart-muscle cells. The intricately detailed frozen wave was then observed in three dimensions using a super-resolution technique that cannot normally observe fast cellular dynamics due to its slow imaging acquisition speed.

“This research began with a bold shift in perspective: to arrest dynamic cellular processes during optical imaging rather than struggle to track them in motion. We believe this will serve as a powerful foundational technique, offering new insights across life-science and medical research,” says senior author Katsumasa Fujita. One of the lead authors, Masahito Yamanaka, adds “Our technique preserves both spatial and temporal features of live cells with instantaneous freezing, making it possible to observe their states in detail. While cells are immobilized, we can take the opportunity to perform highly accurate quantitative measurements with a variety of optical microscopy tools.”

The researchers also demonstrated how this technique improves quantification accuracy. By freezing cells labeled with a fluorescent calcium ion probe, they were able to use exposure times 1000 times longer than practical in live-cell imaging, substantially increasing the measurement accuracy.

To capture transient biological events at precisely defined moments, the researcher integrated an electrically triggered cryogen injection system. With UV light stimulation to induce calcium ion waves, this system enabled freezing of the calcium ion waves at a specific time point after the initiation of the event, with 10 ms precision. This allowed the team to arrest transient biological processes with unprecedented temporal accuracy.

Finally, the team tuned their attention to combining different imaging techniques, which are often difficult to align in time. By the near-instantaneous freezing of samples, multiple imaging modalities can now be applied sequentially without worrying about temporal mismatch. In their study, the team combined spontaneous Raman microscopy and super-resolution fluorescence microscopy on the same cryofixed cells. This allowed them to view intricate cellular information from a number of perspectives at the exact same point in time.

This innovation opens new avenues for observing fast, transient cellular events, providing researchers with a powerful tool to explore the mechanisms underlying dynamic biological processes.

A 23-year-old paper has received an addendum for “possible inadvertent errors” in the figures. But a sleuth says the update doesn’t address issues with the work. 

The 2002 paper, which describes the behavior of Langerhans cells in normal and inflamed skin, was published in Nature Immunology and has been cited 774 times, according to Clarivate’s Web of Science. 

The article received a correction in 2003 to replace two “incorrect” figures. Over 20 years later, PubPeer commenter “Archasia belfragei” flagged issues with different figures, noting in December that some PCR bands were “more similar than expected.”

An addendum this April addressed the data errors, which, according to the notice, “may have occurred during the assembly of PCR measurements.” 

Miriam Merad, lead author of the paper and now Chair of the Department of Immunology and Immunotherapy at Mount Sinai in New York, called the similarity between bands an “unfortunate mistake in assembling the PCR.” She told us “the PCR that was misassembled was measuring housekeeping genes, which are expressed by all cells” and were not the focus of the study. 

The research was conducted at Irving Weissman’s lab at Stanford University in California. 

But image expert and sleuth David Sanders told us the addendum is “inadequate in multiple senses.” While the correction applied to two proteins, the “problematic” data involve the expression of a third, he said. 

“The argument that an image concerning protein expression … somehow justifies thoroughly flawed images of RNA levels is absurd,” Sanders said. The “extent and nature of the problems with the figures would, in my opinion, dictate that the article should have been retracted,” he added.

Merad responded to Sanders’ concerns by emphasizing “there was no misconduct here.” 

One of the paper’s authors, Harvard professor Amy Wagers, had another correction earlier this year to a 2023 paper in Nature Aging. The author correction addressed “potential duplication in two of the micrographs shown in the paper,” the January notice reads. Two of the probes were “unintentionally swapped” while the authors prepared images for the final submission of the paper. Wagers was one of 20 coauthors on this paper, which has been cited 37 times. She did not respond to email requests for comment.

Wagers is the cochair of Harvard’s Department of Stem Cell and Regenerative Biology. In 2010, Wagers retracted a paper from Nature for data concerns. A postdoc in Wagers’ lab was dismissed after accepting responsibility for the “duplicated data and other inappropriate manipulations” cited in a retraction in 2011 from Blood.
Lee Rubin, co-corresponding author and professor of stem cell and regenerative biology at Harvard, told us a coauthor of the paper discovered the mistake with the figures. “We are upset that we made the mistake but feel like we rectified it quickly and openly,” he said.

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Astronomers using the Visible Broadband Imager at NSF’s Daniel K. Inouye Solar Telescope captured dark coronal loop strands with unprecedented clarity during the decay phase of an X1.3-class flare on August 8, 2024. The loops averaged 48.2 km in width — perhaps as thin as 21 km — the smallest coronal loops ever imaged. This marks a potential breakthrough in resolving the fundamental scale of solar coronal loops and pushing the limits of flare modeling into an entirely new realm.

Coronal loops are arches of plasma that follow the Sun’s magnetic field lines, often preceding solar flares that trigger sudden releases of energy associated with some of these magnetic field lines twisting and snapping.

This burst of energy fuels solar storms that can impact Earth’s critical infrastructure.

Astronomers at the Inouye observe sunlight at the H-alpha wavelength (656.28 nm) to view specific features of the Sun, revealing details not visible in other types of solar observations.

“This is the first time the Inouye Solar Telescope has ever observed an X-class flare,” said Dr. Cole Tamburri, an astronomer with the University of Colorado Boulder.

“These flares are among the most energetic events our star produces, and we were fortunate to catch this one under perfect observing conditions.”

Dr. Tamburri and colleagues focused on the razor-thin magnetic field loops (hundreds of them) woven above the flare ribbons.

On average, the loops measured about 48 km across, but some were right at the telescope’s resolution limit.

“Before Inouye, we could only imagine what this scale looked like,” Dr. Tamburri said.

“Now we can see it directly. These are the smallest coronal loops ever imaged on the Sun.”

The Inouye’s Visible Broadband Imager (VBI) instrument, tuned to the H-alpha filter, can resolve features down to 24 km.

That is over two and a half times sharper than the next-best solar telescope, and it is that leap in resolution that made this discovery possible.

“Knowing a telescope can theoretically do something is one thing,” said Dr. Maria Kazachenko, also from the University of Colorado Boulder.

“Actually watching it perform at that limit is exhilarating.”

While the original research plan involved studying chromospheric spectral line dynamics with the Inouye’s Visible Spectropolarimeter (ViSP) instrument, the VBI data revealed something unexpected treasures — ultra-fine coronal structures that can directly inform flare models built with complex radiative-hydrodynamic codes.

“We went in looking for one thing and stumbled across something even more intriguing,” Dr. Kazachenko said.

Theories have long suggested coronal loops could be anywhere from 10 to 100 km in width, but confirming this range observationally has been impossible — until now.

“We’re finally peering into the spatial scales we’ve been speculating about for years,” Dr. Tamburri said.

“This opens the door to studying not just their size, but their shapes, their evolution, and even the scales where magnetic reconnection — the engine behind flares — occurs.”

Perhaps most tantalizing is the idea that these loops might be elementary structures — the fundamental building blocks of flare architecture.

“If that’s the case, we’re not just resolving bundles of loops; we’re resolving individual loops for the first time,” Dr. Tamburri said.

“It’s like going from seeing a forest to suddenly seeing every single tree.”

The imagery itself is breathtaking: dark, threadlike loops arching in a glowing arcade, bright flare ribbons etched in almost impossibly sharp relief — a compact triangular one near the center, and a sweeping arc-shaped one across the top.

“Even a casual viewer would immediately recognize the complexity,” Dr. Tamburri said.

“It’s a landmark moment in solar science.”

“We’re finally seeing the Sun at the scales it works on.”

The team’s paper appears in the Astrophysical Journal Letters.

_____

Cole A. Tamburri et al. 2025. Unveiling Unprecedented Fine Structure in Coronal Flare Loops with the DKIST. ApJL, in press; doi: 10.3847/2041-8213/adf95e

Titans Space Industries, a commercial space company, selected a new cohort of astronaut candidates this spring – and among them is NASA citizen scientist, Benedetta Facini. She has participated in not one, but many NASA citizen science projects: Cloudspotting on Mars, Active Asteroids, Daily Minor Planet, GLOBE, Exoasteroids and International Astronomical Collaboration (IASC). We asked her a few questions about her work with NASA and her path to becoming an astronaut candidate.

Q: How did you learn about NASA Citizen Science?

A: Through colleagues and social media, I often came across people talking about Citizen Science, and this immediately caught my curiosity. I did some online research on the subject, and I asked some colleagues already involved in it. Finally, I managed to find the way to participate by exploring the programs offered by NASA Citizen Science, which impressed me with their variety.

Q: What would you say you have gained from working on these NASA projects?

A: Curiosity in discovering new things and a lot of patience: many projects indeed require attention and, as mentioned, patience. I was pleased to discover that even NASA relies on “ordinary people” to carry out research, giving them the opportunity to learn new things using simple tools.

I also gained hands-on experience in analyzing real data and identifying celestial objects to contribute to real research efforts. My favorite part was to learn to recognize the pattern of clouds in data collected by the Mars Climate Sounder on the Mars Reconnaissance Orbiter.

I have learned the importance of international collaboration: I know many citizen scientists now, and interacting with them teaches me a lot every day. 

Q. What do you do when you’re not working on citizen science?

A: I am a student and a science communicator. I share my knowledge and enthusiasm through social media, schools, webinars around the world, and space festivals across Italy where I have the opportunity to engage with a wide audience, from young students to adults.

Recently, I achieved a major milestone: I was selected as an Astronaut Candidate by the commercial space company, Titans Space Industries. I am thrilled to soon begin the basic training, which marks the first step toward realizing my dream of becoming an astronaut and contributing directly to human spaceflight and scientific research.

Q. What do you need to do to become an astronaut?

A: Gain as much experience as possible. During astronaut selection, not only academic achievements are evaluated, but also professional and personal experiences.

Every skill can be useful during the selection process: the ability to work in a team, which is essential during space missions; survival skills; experience as a diver, skydiver, or pilot; knowledge of other languages; and the ability to adapt to different situations.

I would also like to debunk a myth: you don’t need to be Einstein and fit as an Olympic level athlete; you just need to be good at what you do and be healthy.

Q: How has citizen science helped you with your career?

A: Citizen Science was very helpful for my career as a science communicator, as it gave me the opportunity to show people that anyone can contribute to the space sector. At the same time, it has allowed me to become a mentor and a point of reference for many students (mainly with the IASC project).

The hands-on experience I gained in analyzing real data was also very helpful for my academic career, too. I had never had real data to work with before, and this experience proved extremely valuable for the practical courses in my physics degree program.

Q. Do you have any advice you’d like to share for other citizen scientists or for people who want to become astronauts?

A: For other citizen scientists my advice is to stay curious and persistent.

Don’t be afraid to ask for help and interact with other colleagues because the goal of the NASA Citizen Science program is international collaboration and every small contribution can make a difference.

For aspiring astronauts, my advice is to gain as much experience as possible. Academic results are important but hands-on skills, teamwork, adaptability, and real experiences are also important.

Stay passionate and never lose your curiosity; the astronaut path is challenging; don’t give up after an eventual first rejection. You will always meet people trying to make you change your mind and your dream, even people from your family, but don’t stop in front of obstacles. The greatest regret is knowing you didn’t try to make your dream come true.

Quoting my inspiration, Italian astronaut Paolo Nespoli: “You need to have the ability and the courage to dream of impossible things. Everyone can dream of things that are possible. Dream of something impossible, one of those things that, when you say it out loud, people look at you and say: “Sure, study hard and you’ll make it,” but deep down no one really believes it. Those are the impossible things that are worth trying to do!”

Q: Thank you for sharing your story with us! Is there anything else you would like to add?

A: I would like to thank the team behind NASA Citizen Science.

These projects play a crucial role in keeping students’ passion for science alive and guiding them toward a potential career in this field.

Knowing that I have contributed to helping scientists is incredibly motivating and encourages me and students around the world to keep going, stay curious, and continue pursuing our path in the science field.

The opportunity to participate in these projects while learning is inspiring and it reinforces the idea that everyone, regardless of their background, can make a real impact in the scientific community.

A glowing hand stretches across the cosmos, with its palm and fingers sculpted from the wreckage of a massive stellar explosion.

The eerie structure is part of the nebula MSH 15-52, powered by pulsar B1509-58 — a rapidly spinning neutron star that is only about 12 miles (20 kilometers) in diameter. By combining radio data from the Australia Telescope Compact Array (ATCA) with X-rays from NASA’s Chandra X-ray Observatory, astronomers created a new view of the nebula, which spans over 150 light-years and resembles a human hand reaching toward the remains of the supernova — formally known as RCW 89 — that formed the pulsar at the heart of the image.

“MSH 15–52 and RCW 89 show many unique features not found in other young sources,” according to a statement from the Chandra X-ray Observatory, releasing the new composite image. “There are, however, still many open questions regarding the formation and evolution of these structures.”

The central object, pulsar B1509-58, formed when a massive star ran out of fuel and collapsed before exploding as a supernova. The pulsar spins nearly seven times per second and has a magnetic field some 15 trillion times stronger than Earth’s. Despite its small size, it acts like a cosmic dynamo, accelerating particles to extreme energies and driving winds that carve the nebula into its hand-like form.