“Cas A represents our best opportunity to look at the debris field of an exploded star and run a kind of stellar autopsy to understand what type of star was there beforehand and how that star exploded,” said Danny Milisavljevic of Purdue University in West Lafayette, Indiana, principal investigator of the Webb program that captured these observations.

“Compared to previous infrared images, we see incredible detail that we haven’t been able to access before,” added Tea Temim of Princeton University in Princeton, New Jersey, a co-investigator on the program.

Cassiopeia A is a prototypical supernova remnant that has been widely studied by a number of ground-based and space-based observatories, including NASA’s Chandra X-ray Observatory. The multi-wavelength observations can be combined to provide scientists with a more comprehensive understanding of the remnant.

Dissecting the Image

The striking colors of the new Cas A image, in which infrared light is translated into visible-light wavelengths, hold a wealth of scientific information the team is just beginning to tease out. On the bubble’s exterior, particularly at the top and left, lie curtains of material appearing orange and red due to emission from warm dust. This marks where ejected material from the exploded star is ramming into surrounding circumstellar gas and dust.

Interior to this outer shell lie mottled filaments of bright pink studded with clumps and knots. This represents material from the star itself, which is shining due to a mix of various heavy elements, such as oxygen, argon, and neon, as well as dust emission.

“We’re still trying to disentangle all these sources of emission,” said Ilse De Looze of Ghent University in Belgium, another co-investigator on the program.

The stellar material can also be seen as fainter wisps near the cavity’s interior.

Perhaps most prominently, a loop represented in green extends across the right side of the central cavity. “We’ve nicknamed it the Green Monster in honor of Fenway Park in Boston. If you look closely, you’ll notice that it’s pockmarked with what look like mini-bubbles,” said Milisavljevic. “The shape and complexity are unexpected and challenging to understand.”

Origins of Cosmic Dust — and Us

Among the science questions that Cas A may help answer is: Where does cosmic dust come from? Observations have found that even very young galaxies in the early universe are suffused with massive quantities of dust. It’s difficult to explain the origins of this dust without invoking supernovae, which spew large quantities of heavy elements (the building blocks of dust) across space.

However, existing observations of supernovae have been unable to conclusively explain the amount of dust we see in those early galaxies. By studying Cas A with Webb, astronomers hope to gain a better understanding of its dust content, which can help inform our understanding of where the building blocks of planets and ourselves are created.

“In Cas A, we can spatially resolve regions that have different gas compositions and look at what types of dust were formed in those regions,” explained Temim.

Supernovae like the one that formed Cas A are crucial for life as we know it. They spread elements like the calcium we find in our bones and the iron in our blood across interstellar space, seeding new generations of stars and planets.

“By understanding the process of exploding stars, we’re reading our own origin story,” said Milisavljevic. “I’m going to spend the rest of my career trying to understand what’s in this data set.”

The Cas A remnant spans about 10 light-years and is located 11,000 light-years away in the constellation Cassiopeia.

The answer: You see how it impacts things that you can see. In the case of dark matter, astronomers watch how light from distant galaxies bends around it.

An international team of astrophysicists and cosmologists have spent the past year teasing out the secrets of this elusive material, using sophisticated computer simulations and the observations from the one of the most powerful astronomical cameras in the world, the Hyper Suprime-Cam (HSC). The team is led by astronomers from Princeton University and the astronomical communities of Japan and Taiwan, using data from the first three years of the HSC sky survey, a wide-field imaging survey carried out with the 8.2-meter Subaru telescope on the summit of Maunakea in Hawai’i. Subaru is operated by the National Astronomical Observatory of Japan; its name is the Japanese word for the cluster of stars we call the Pleiades.

The team presented their findings at a webinar attended by more than 200 people, and they will share their work at the “Future Science with CMB x LSS” conference in Japan.

“Our overall goal is to measure some of the most fundamental properties of our universe,” said Roohi Dalal, a graduate student in astrophysics at Princeton. “We know that dark energy and dark matter make up 95% of our universe, but we understand very little about what they actually are and how they’ve evolved over the history of the universe. Clumps of dark matter distort the light of distant galaxies through weak gravitational lensing, a phenomenon predicted by Einstein’s General Theory of Relativity. This distortion is a really, really small effect; the shape of a single galaxy is distorted by an imperceptible amount. But when we make that measurement for 25 million galaxies, we’re able to measure the distortion with quite high precision.”

To jump to the punchline: The team has measured a value for the “clumpiness” of the universe’s dark matter (known to cosmologists as “S₈“) of 0.776, which aligns with values that other gravitational lensing surveys have found in looking at the relatively recent universe — but it does not align with the value of 0.83 derived from the Cosmic Microwave Background, which dates back to the universe’s origins.

The gap between these two values is small, but as more and more studies confirm each of the two values, it doesn’t appear to be accidental. The other possibilities are that there’s some as-yet unrecognized error or mistake in one of these two measurements or the standard cosmological model is incomplete in some interesting way.

“We’re still being fairly cautious here,” said Michael Strauss, chair of Princeton’s Department of Astrophysical Sciences and one of the leaders of the HSC team. “We’re not saying that we’ve just discovered that modern cosmology is all wrong, because, as Roohi has emphasized, the effect that we’re measuring is a very subtle one. Now, we think we’ve done the measurement right. And the statistics show that there’s only a one in 20 chance that it’s just due to chance, which is compelling but not completely definitive. But as we in the astronomy community come to the same conclusion over multiple experiments, as we keep on doing these measurements, perhaps we’re finding that it’s real.”

Hiding and uncovering the data

The idea that some change is needed in the standard cosmological model, that there is some fundamental piece of cosmology yet to be discovered, is a deliciously enticing one for some scientists.

“We are human beings, and we do have preferences. That’s why we do what we call a ‘blinded’ analysis,” Strauss said. “Scientists have become self-aware enough to know that we will bias ourselves, no matter how careful we are, unless we carry out our analysis without allowing ourselves to know the results until the end. For me, I would love to really find something fundamentally new. That would be truly exciting. But because I am prejudiced in that direction, we want to be very careful not to let that influence any analysis that we do.”

To protect their work from their biases, they quite literally hid their results from themselves and their colleagues — month after month after month.

“I worked on this analysis for a year and didn’t get to see the values that were coming out,” said Dalal.

The team even added an extra obfuscating layer: they ran their analyses on three different galaxy catalogs, one real and two with numerical values offset by random values.

“We didn’t know which of them was real, so even if someone did accidentally see the values, we wouldn’t know if the results were based on the real catalog or not,” she said.

On February 16, the international team gathered together on Zoom — in the evening in Princeton, in the morning in Japan and Taiwan — for the “unblinding.”

“It felt like a ceremony, a ritual, that we went through,” Strauss said. “We unveiled the data, and ran our plots, immediately we saw it was great. Everyone went, ‘Oh, whew!’ and everyone was very happy.”

Dalal and her roommate popped a bottle of champagne that night.

A huge survey with the world’s largest telescope camera

HSC is the largest camera on a telescope of its size in the world, a mantle it will hold until the Vera C. Rubin Observatory currently under construction in the Chilean Andes, begins the Legacy Survey of Space and Time (LSST) in late 2024. In fact, the raw data from HSC is processed with the software designed for LSST. “It is fascinating to see that our software pipelines are able to handle such large quantities of data well ahead of LSST,” said Andrés Plazas, an associate research scholar at Princeton.

The survey that the research team used covers about 420 square degrees of the sky, about the equivalent of 2000 full moons. It’s not a single contiguous chunk of sky, but split among six different pieces, each about the size that you could cover with an outstretched fist. The 25 million galaxies they surveyed are so distant that instead of seeing these galaxies as they are today, the HSC recorded how they were billions of years ago.

Each of these galaxies glows with the fires of tens of billions of suns, but because they are so far away, they are extremely faint, as much as 25 million times fainter than the faintest stars we can see with the naked eye.

“It is extremely exciting to see these results from HSC collaboration, especially as this data is closest to what we expect from Rubin Observatory, which the community is working towards together,” said cosmologist Alexandra Amon, a Senior Kavli Fellow at Cambridge University and a senior researcher at Trinity College, who was not involved in this research. “Their deep survey makes for beautiful data. For me, it is intriguing that HSC, like the other independent weak lensing surveys, point to a low value for S₈ — it’s important validation, and exciting that these tensions and trends force us to pause and think about what that data is telling us about our Universe!”

The standard cosmological model

The standard model of cosmology is “astonishingly simple” in some ways, explained Andrina Nicola of the University of Bonn, who advised Dalal on this project when she was a postdoctoral scholar at Princeton. The model posits that the universe is made up of only four basic constituents: ordinary matter (atoms, mostly hydrogen and helium), dark matter, dark energy and photons.

According to the standard model, the universe has been expanding since the Big Bang 13.8 billion years ago: it started out almost perfectly smooth, but the pull of gravity on the subtle fluctuations in the universe has caused structure — galaxies enveloped in dark matter clumps — to form. In the present-day universe, the relative contributions of ordinary matter, dark matter, dark energy are about 5%, 25% and 70%, plus a tiny contribution from photons.

The standard model is defined by only a handful of numbers: the expansion rate of the universe; a measure of how clumpy the dark matter is (S₈); the relative contributions of the constituents of the universe (the 5%, 25%, 70% numbers above); the overall density of the universe; and a technical quantity describing how the clumpiness of the universe on large scales relates to that on small scales.

“And that’s basically it!” Strauss said. “We, the cosmological community, have converged on this model, which has been in place since the early 2000s.”

Cosmologists are eager to test this model by constraining these numbers in various ways, such as by observing the fluctuations in the Cosmic Microwave Background (which in essence is the universe’s baby picture, capturing how it looked after its first 400,000 years), modeling the expansion history of the universe, measuring the clumpiness of the universe in the relatively recent past, and others.

“We’re confirming a growing sense in the community that there is a real discrepancy between the measurement of clumping in the early universe (measured from the CMB) and that from the era of galaxies, ‘only’ 9 billion years ago,” said Arun Kannawadi, an associate research scholar at Princeton who was involved in the analysis.

Five lines of attack

Dalal’s work does a so-called Fourier-space analysis; a parallel real-space analysis was led by Xiangchong Li of Carnegie Mellon University, who worked in close collaboration with Rachel Mandelbaum, who completed her physics A.B. in 2000 and her Ph.D. in 2006, both from Princeton. A third analysis, a so-called 3×2-point analysis, takes a different approach of measuring the gravitational lensing signal around individual galaxies, to calibrate the amount of dark matter associated with each galaxy. That analysis was led by Sunao Sugiyama of the University of Tokyo, Hironao Miyatake (a former Princeton postdoctoral fellow) of Nagoya University and Surhud More of the Inter-University Centre for Astronomy and Astrophysics in Pune, India.

These five sets of analyses each use the HSC data to come to the same conclusion about S₈.

Doing both the real-space analysis and the Fourier-space analysis “was sort of a sanity check,” said Dalal. She and Li worked closely to coordinate their analyses, using blinded data. Any discrepancies between those two would say that the researchers’ methodology was wrong. “It would tell us less about astrophysics and more about how we might have screwed up,” Dalal said.

“We didn’t know until the unblinding that two results were bang-on identical,” she said. “It felt miraculous.”

Sunao added: “Our 3×2-point analysis combines the weak lensing analysis with the clustering of galaxies. Only after unblinding did we know that our results were in beautiful agreement with those of Roohi and Xiangchong. The fact that all these analyses are giving the same answer gives us confidence that we’re doing something right!”

The Johns Hopkins University team reports for the first time the mechanisms by which a protein known as histone H3 controls when and how worm embryos produce both highly specific cells and pluripotent cells, cells that can turn certain genes on and off to produce varying kinds of body tissue. The details are published today in Science Advances.

The new research could shed light on how mutations associated with these proteins influence various diseases. In children and young adults, for example, histone H3 is closely associated with various cancers.

“These mutations are highly prevalent in different cancers, so understanding their normal role in regulating cell fate and potentially differentiation of tissues may help us understand why some of them are more prevalent in certain diseases,” said lead author Ryan J. Gleason, a postdoctoral fellow in biology at Johns Hopkins. “The histones that we’re looking at are some of the most mutated proteins in cancer and other diseases.”

Histones are the building blocks of chromatin, the structural support of chromosomes within a cell’s nucleus. While histone H3 is particularly abundant in multicellular organisms such as plants and animals, unicellular organisms teem with a nearly identical variant of H3. That’s why scientists think the difference in rations of H3 and its variant hold crucial clues in the mystery of why pluripotent cells are so versatile during early development.

The researchers revealed that as C. elegans roundworm embryos grew, increasing H3 levels in their systems restricted the potential or “plasticity” of their pluripotent cells. When the team changed the worm’s genome to lower the amount of H3, they successfully prolonged the window of time for pluripotency that is normally lost in older embryos.

“As cells differentiate, you start to get a hundredfold histone H3 being expressed at that time period, which coincides with that lineage-specific regulation,” Gleason said. “When you lower the amount of H3 during embryogenesis, we were able to change the normal path of development to adopt alternative paths of cell fate.”

In pluripotent cells, histones help switch certain genes on and off to commit to specific cell types, be they neurons, muscles, or other tissue. Highly regulated by histones, genes act as a voice that tell cells how to develop. How quiet or loud a gene is determines a cell’s fate.

The new findings come from the gene-editing technique CRISPR, which helped the team track the role the two histones played as the worm’s offspring developed. CRISPR has made it much easier for scientists in the last decade to study the nuts and bolts of changing genetic material and spot what that does to animal, plant, and microbe traits, Gleason said.

Even though the C. elegans roundworm gives finer insights into how these pluripotent cells evolve, further research is needed to zero in on how histones might also underpin embryogenesis in humans and animals composed of hundreds of types of cells, said Xin Chen, a Johns Hopkins biology professor and co-investigator.

“Even though we are using this small worm to make these discoveries, really this finding should not be specific to one animal,” Chen said. “It’s hard to imagine the findings are only going to be applicable to one histone or one animal but, of course, more research needs to be done.”

The team includes Yanrui Guo of Johns Hopkins, Christopher S. Semancik of Tufts University, Cindy Ow of University of California, San Francisco, and Gitanjali Lakshminarayanan of Dana-Farber Cancer Institute.

The research is supported by grants NIGMS/NIH F32GM119347, NICHD/NIH K99HD09605, NIGMS/NIH R35GM127075, and a Faculty Scholarship and Investigator program from Howard Hughes Medical Institute.

The intestinal epithelium, made up of a layer of cells that lines the intestine, plays an important role in IBD because it can be easily disrupted during gut inflammation. A specialized type of epithelial cells are Paneth cells. The antimicrobial peptides these cells produce help regulate the gut microbiota, or the community of microorganisms that exist in the gut.

A research team led by Declan F. McCole, a biomedical scientist and IBD expert at the University of California, Riverside, reports in their mouse study that reduced activity of the IBD risk gene PTPN2 in intestinal epithelial cells can lead to a decrease in the production of Paneth cell antimicrobial peptides.

The study, published in the journal Cellular and Molecular Gastroenterology and Hepatology, establishes a critical link between PTPN2 and Paneth cells that plays a major role in maintaining normal gut microbe properties.

“This study develops our focus on improving personalized medicine approaches in IBD by understanding how patients with variants in the PTPN2 gene develop IBD,” said McCole, a professor of biomedical sciences in the School of Medicine. “Loss of PTPN2 can lead also to selective loss of Paneth cells in the intestinal epithelium. This loss of PTPN2 causes significant changes in the gut microbiota and increases a particular E. coli.”

Escherichia coli, or E. coli, are bacteria found in the environment, foods, and intestines of people and animals. McCole explained that the E. coli in question, the adherent-invasive E. coli, or AIEC, is increased in IBD and worsens inflammation. First identified in Crohn’s disease patients, AIEC can adhere to and invade epithelial cells as well as immune cells called macrophages.

“AIEC are the strongest candidate for a causal role for bacteria in IBD,” he said.

According to McCole, Paneth cells do not function properly in many patients living with IBD, and this can serve as a marker of disease. The antimicrobial peptides these cells produce are crucially relevant to the intestine’s protective barrier for regulating the relative proportions of bacteria and their interactions with each other. They also help neighboring intestinal stem cells function better.

“We know that in IBD, Paneth cells are often unable to produce sufficient antimicrobial peptides or respond appropriately to gut bacteria,” McCole said. “These functional defects can also be associated with changes in the structure of Paneth cells that reduce their ability to secrete the protective antimicrobial peptides, leading to increases in the populations of bacteria associated with IBD, such as AIEC. These structural changes in the appearance of Paneth cells can also serve as a marker of disease in IBD, especially Crohn’s disease.”

McCole was joined in the study by Vinicius Canale, Marianne R. Spalinger, Rocio Alvarez, Anica Sayoc-Becerra, Golshid Sanati, Salomon Manz, Pritha Chatterjee, Alina N. Santos, Hillmin Lei, Sharon Jahng, Timothy Chu, and Ali Shawki of UCR; Elaine Hanson and Lars Eckmann of UC San Diego; and André J. Ouellette of the University of Southern California.

The study was supported by the Crohn’s and Colitis Foundation; Swiss National Science Foundation; American Gastroenterological Association; Science Without Borders Program; and California Institute of Regenerative Medicine.

“This work sets the foundation for our new research project that will identify pharmacologic agents capable of rescuing Paneth cell function and reducing the contributions of microbes to intestinal inflammation,” McCole said.

How OH itself forms in the atmosphere was viewed as a complete story, but in new research published in Proceedings of the National Academy of Sciences, a research team that includes Sergey Nizkorodov, a University of California, Irvine professor of chemistry, report that a strong electric field that exists at the surface between airborne water droplets and the surrounding air can create OH by a previously unknown mechanism.

It’s a finding that stands to reshape how scientists understand how the air clears itself of things like human-emitted pollutants and greenhouse gases, which OH can react with and eliminate. “You need OH to oxidize hydrocarbons, otherwise they would build up in the atmosphere indefinitely,” said Nizkorodov.

“OH is a key player in the story of atmospheric chemistry. It initiates the reactions that break down airborne pollutants and helps to remove noxious chemicals such as sulfur dioxide and nitric oxide, which are poisonous gases, from the atmosphere,” said Christian George, an atmospheric chemist at the University of Lyon in France and lead author of the new study. “Thus, having a full understanding of its sources and sinks is key to understanding and mitigating air pollution.”

Before, researchers assumed that sunlight was the chief driver of OH formation.

“The conventional wisdom is that you have to make OH by photochemistry or redox chemistry. You have to have sunlight or metals acting as catalysts,” Nizkorodov said. “What this paper says in essence is you don’t need any of this. In the pure water itself, OH can be created spontaneously by the special conditions on the surface of the droplets.”

The team built on research from Stanford University scientists led by Richard Zare that reported spontaneous formation of hydrogen peroxide on the surfaces of water droplets. The new findings help interpret the unexpected results from the Zare group.

The team measured OH concentrations in different vials — some containing an air-water surface and others containing only water without any air — and tracked OH production in darkness by including a “probe” molecule in the vials that fluoresces when it reacts with OH.

What they saw is that OH production rates in darkness mirror those and even exceed rates from drivers like sunlight exposure. “Enough of OH will be created to compete with other known OH sources,” said Nizkorodov. “At night, when there is no photochemistry, OH is still produced and it is produced at a higher rate than would otherwise happen.”

The findings, Nizkorodov reported, alter understanding of the sources of OH, something that will change how other researchers build computer models that attempt to forecast how air pollution happens.

“It could change air pollution models quite significantly,” Nizkorodov said. “OH is an important oxidant inside water droplets and the main assumption in the models is that OH comes from the air, it’s not produced in the droplet directly.”

To determine whether this new OH production mechanism plays a role, Nizkorodov thinks the next step is to perform carefully designed experiments in the real atmosphere in different parts of the world.

But first, the team expects the results to make a splash in the atmospheric research community.

“A lot of people will read this but will not initially believe it and will either try to reproduce it or try to do experiments to prove it wrong,” said Nizkorodov. “There will be many lab experiments following up on this for sure.”

He added that UCI is a prime place for such science to continue happening, because other labs at UCI, like that of Ann Marie Carlton, professor of chemistry, focus their efforts on the role water droplets play in the atmosphere.

This project, which was funded by the European Research Council, involved researchers from France’s University Claude Bernard, China’s Guangdong University of Technology, and Israel’s Weizmann Institute.

“We found that lonely individuals are exceptionally dissimilar to their peers in the way that they process the world around them … even when taking into account the number of friends that they have,” said lead author Elisa C. Baek (University of Southern California) in an interview. Her study showed that lonely individuals’ neural responses differ from those of other people, suggesting that “seeing the world differently than those around you may be a risk factor for loneliness, even if you regularly socialize with them.”

Baek and colleagues Ryan Hyon, Karina López, Meng Du, Mason A. Porter, and Carolyn Parkinson (University of California, Los Angeles [UCLA]) came to this conclusion by comparing the functional magnetic resonance imaging (fMRI) scans of 63 first-year university students.

During each 90-minute scan, participants viewed 14 engaging video clips in the same order. After the scan, they self-reported their feelings of social connection using the UCLA Loneliness Scale. Earlier in the academic year, each participant had also completed a social network survey in which they were asked to list the names of each person with whom they studied, ate meals, or otherwise hung out during their first several months as students.

In order to analyze these data, Baek and colleagues divided participants into two groups: a “lonely” group with participants who scored higher than the median on the loneliness scale and a nonlonely group with participants who scored under the median.

When the researchers compared these participants’ scans, they found that the brain activity of lonely participants was very dissimilar to that of both nonlonely participants and other lonely participants. By comparison, the brain activity of nonlonely participants was similar to that of other nonlonely participants. This was especially true in the default-mode network, in which shared brain activity appears to be associated with interpreting narratives and friendships in a similar manner, and in the reward-processing areas of the brain, the researchers wrote. These findings remained significant even when the researchers controlled for demographic characteristics and the size of participants’ social networks.

“Lonely people process the world idiosyncratically, which may contribute to the reduced sense of being understood that often accompanies loneliness,” the researchers explained.

Additional research is needed in order to determine the underlying cause of these results, however, Baek said.

“One possibility is that lonely individuals do not find value in the same aspects of situations or scenes as their peers,” Baek and colleagues wrote. “This may result in a reinforcing feedback loop in which lonely individuals perceive themselves to be different from their peers, which may in turn lead to further challenges in achieving social connection.”

Another possibility is that loneliness itself could lead people to process information differently, the researchers added.

In either case, learning more about how lonely people think, and how to promote shared understanding, could help identify new pathways for reducing loneliness, Baek said.

“Copper is one of the most studied and relevant surfaces, both in catalysis and in corrosion science,” explained Anibal Boscoboinik, materials scientist at CFN. “So many mechanical parts that are used in industry are made of copper, so trying to understand this element of the corrosion processes is very important.”

“I’ve always liked looking at copper systems,” said Ashley Head also a materials scientist at CFN. “They have such interesting properties and reactions, some of which are really striking.”

Gaining a better understanding of oxide catalysts gives researchers more control of the chemical reactions they produce, including solutions for clean energy. Copper, for example, can catalytically form and convert methanol into valuable fuels, so being able to control the amount of oxygen and number of electrons on copper is a key step to efficient chemical reactions.

Peroxide as a Proxy

Peroxides are chemical compounds that contain two oxygen atoms linked by shared electrons. The bond in peroxides is fairly weak, allowing other chemicals to alter its structure, which makes them very reactive. In this experiment, scientists were able to alter the redox steps of catalytic oxidation reactions on an oxidized copper surface (CuO) by identifying the makeup of peroxide species formed with different gases: O₂ (oxygen), H₂ (hydrogen), and CO (carbon monoxide).

Redox is a combination of reduction and oxidation. In this process, the oxidizing agent gains an electron and the reducing agent loses an electron. When comparing these different peroxide species and how these steps played out, researchers found that a surface layer of peroxide significantly enhanced CuO reducibility in favor of H₂ oxidation. They also found that, on the other hand, it acted as an inhibitor to suppress CuO reduction against CO (carbon monoxide) oxidation. They found that this opposite effect of the peroxide on the two oxidation reactions stems from the modification of the surface sites where the reaction takes place.

By finding these bonding sites and learning how they promote or inhibit oxidation, scientists can use these gases to gain more control of how these reactions play out. In order to tune these reactions though, scientists had to get a clear look at what was happening.

The Right Tools for the Job

Studying this reaction in situ was important to the team, since peroxides are very reactive and these changes happen fast. Without the right tools or environment, it’s hard to catch such a limited moment on the surface.

Peroxide species on copper surfaces were never observed using in-situ infrared (IR) spectroscopy in the past. With this technique, researchers use infrared radiation to get a better understanding of a material’s chemical properties by looking at the way the radiation is absorbed or reflected under reaction conditions. In this experiment, scientists were able to differentiate “species” of peroxide, with very slight variations in the oxygen they were carrying, which would have otherwise been very hard to identify on a metal oxide surface.

“I got really excited when I was looking up the infrared spectra of these peroxide species on a surface and seeing that there weren’t many publications. It was exciting that we could see these differences using a technique that’s not widely applied to these kind of species,” recalled Head.

IR spectroscopy on its own wasn’t enough to be sure though, which is why the team also used another spectroscopy technique called ambient pressure X-ray Photoelectron Spectroscopy (XPS). XPS uses lower energy x-rays to kick electrons out of the sample. The energy of these electrons gives scientists clues about the chemical properties of atoms in the sample. Having both techniques available through the CFN User Program was key to making this research possible.

“One of the things that we pride ourselves in is the instruments that we have and modified here,” said Boscoboinik. “Our instruments are connected, so users can move the sample in a controlled environment between these two techniques and study them in situ to get complementary information. In most other circumstances, a user would have to take the sample out to go to a different instrument, and that change of environment could alter its surface.”

“A nice feature of CFN lies not only in its state-of-the-art facilities for science, but also the opportunities it provides to train young researchers,” said Guangwen Zhou professor at the Thomas J. Watson College of Engineering and Applied Science’s Department of Mechanical Engineering and the Materials Science program at Binghamton University. “Each of the students involved have benefited from extensive, hands-on experience in the microscopy and spectroscopy tools available at CFN.”

This work was accomplished with the contributions of four PhD students in Zhou’s group: Yaguang Zhu and Jianyu Wang, the first co-authors of this paper, and Shyam Patel and Chaoran Li. All of these students are early in their career, having just earned their PhDs in 2022.

Future Findings

The results of this study may apply to other types of reactions and other catalysts besides copper. These findings and the processes and techniques that led scientists there could find their ways into related research. Metal oxides are widely used as catalysts themselves or components in catalysts. Tuning peroxide formation on other oxides could be a way to block or enhance surface reactions during other catalytic processes.

“I’m involved in some other projects related to copper and copper oxides, including transforming carbon dioxide to methanol to use as a fuel for clean energy,” said Head. “Looking at these peroxides on the same surface that I use has the potential to make an impact on other projects using copper and other metal oxides.”

The research, published this week in JAMA Network Open, compared magnetic resonance imaging (MRI) brain scans of older adults who had high blood pressure between the ages of 30 to 40 with older adults who had normal blood pressure.

The researchers found that the high blood pressure group had significantly lower regional brain volumes and worse white matter integrity. Both factors are associated with dementia.

The research also showed that the negative brain changes in some regions — such as decreased grey matter volume and frontal cortex volume — were stronger in men. They note the differences may be related to the protective benefits of estrogen before menopause.

“Treatment for dementia is extremely limited, so identifying modifiable risk and protective factors over the life course is key to reducing disease burden,” said first author Kristen M. George, an assistant professor in the Department of Public Health Sciences.

“High blood pressure is an incredibly common and treatable risk factor associated with dementia. This study indicates hypertension status in early adulthood is important for brain health decades later,” George said.

High blood pressure prevalent in U.S.

High blood pressure, also known as hypertension, is blood pressure that is higher than normal. A normal blood pressure level is less than 130/80 mmHg. The Centers for Disease Control and Prevention estimates that 47% of adults in the United States have hypertension.

The rate of high blood pressure varies by sex and race. About 50% of men have high blood pressure compared to 44% of women. The rate of hypertension is about 56% in Black adults, 48% in white adults, 46% in Asian adults and 39% in Hispanic adults. African Americans ages 35 to 64 years are 50% more likely to have high blood pressure than whites.

Data from healthy aging studies

The researchers looked at data from 427 participants from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study and the Study of Healthy Aging in African Americans (STAR). This provided them with health data from 1964 to 1985 for a diverse cohort of older Asian, Black, Latino and white adults.

They obtained two blood pressure readings from when the participants were between the ages of 30 to 40. This allowed them to determine if they had been hypertensive, transitioning to hypertensive or had normal blood pressure in young adulthood.

MRI scans of the participants conducted between 2017 and 2022 allowed them to look for late-life neuroimaging biomarkers of neurodegeneration and white matter integrity.

A significant reduction in cerebral gray matter volume is seen in both men and women with hypertension but is stronger in men.

Brain scans reveal differences

Compared to participants with normal blood pressure, the brain scans of those transitioning to high blood pressure or with high blood pressure showed lower cerebral gray matter volume, frontal cortex volume and fractional anisotropy (a measure of brain connectivity). The scores for men with high blood pressure were lower than those for women.

The study joins a growing body of evidence that cardiovascular risk factors in young adulthood are detrimental to late-life brain health.

The researchers note that due to the sample size, they could not examine racial and ethnic differences and recommended interpreting results regarding sex differences with caution. They also note that the MRI data was only available from one time-point late in life. This can only determine physical properties like volumetric differences, not specific evidence of neurodegeneration over time.

“This study truly demonstrates the importance of early life risk factors, and that to age well, you need to take care of yourself throughout life — heart health is brain health,” said Rachel Whitmer, senior author of the study. Whitmer is a professor in the departments of Public Health Sciences and Neurology and chief of the Division of Epidemiology. She’s also the associate director of the UC Davis Alzheimer’s Disease Center.

“We are excited to be able to continue following these participants and to uncover more about what one can do in early life to set yourself up for healthy brain aging in late life,” Whitmer said.

Additional authors of the study include Pauline Maillard, Evan Fletcher, Dan M. Mungas and Charles DeCarli, UC Davis; Paola Gilsanz, Kaiser Permanente Division of Research; Rachel L. Peterson, University of Montana, Missoula; Joseph Fong and Elizabeth Rose Mayeda from UCLA; L. Barnes from Rush Medical College; M. Maria Glymour from UCSF.

The study, led by senior author Anthony R. Flores, MD, PhD, MPH, associate professor and chief of pediatric infectious diseases at McGovern Medical School at UTHealth Houston, was published this month in Clinical Infectious Diseases.

During the COVID-19 pandemic, the rate of other infectious diseases dropped due to safety measures such as social distancing and mask-wearing, according to researchers. But as those safety measures began to lift, diseases such as respiratory syncytial virus, the flu, and group A strep all experienced a resurgence in cases.

Infectious disease experts first noticed the rise in cases in the UK, now with 355 deaths of which 40 were children dying from severe group A strep infections. Researchers such as Flores then turned to what was occurring in the U.S.

“In 2020 and 2021, the overall number of infections that we saw due to group A strep were far lower than what we had seen before the pandemic,” Flores said. “When we look at the number of infections by quarter, historically, pre-pandemic cases of group A strep were pretty consistent from quarter to quarter with a little variation and more infections in the winter months. But during the last quarter of 2022, the number of infections we saw, including invasive infections, were far greater than what we’d ever seen before.”

In 2022, a total of 318 individual group A strep cases were identified in young children in Houston. Researchers looked at three group A strep disease types: invasive group A strep (iGAS), skin and soft tissue infections (SSTI), and pharyngeal, or throat, infections (PHG). The study found that group A strep strains derived from iGAS accounted for 31.4%, SSTI for 17.6%, and pharyngeal for 50.9%.

“Proportionately speaking, if we just looked at the percentage of all infections that were invasive, it was the same as we had seen in the past,” Flores said. “It wasn’t like, all of a sudden, 75% of our cases are invasive diseases. What we’re seeing is an increase in the total number of infections.”

The study also found that emm12 group A strep strains were disproportionately represented, compared to emm1 group A strep, which was the dominant emm type pre-pandemic. Emm type is a marker that differentiates different strains of group A strep.

“By looking at the molecular epidemiology, we can look at specific things about the bacteria that give us clues as to whether or not something is changing,” Flores said. “What we will be observing as we go forward is whether it will shift back to what it was pre-pandemic, and if it doesn’t, then we hope to have some work underway that is going to tell us why.”

As cases of group A strep continued to be high in the first quarter of 2023 in Houston, the disease is a cause for concern for pediatricians who see children with symptoms of group A strep.

“The reason why this is important is we’re seeing group A strep more frequently than what we have seen in the past, and therefore, if a physician has a child coming in with a sore throat or with a skin infection, we should have a high index of suspicion for group A strep,” Flores said.

Co-authors on the paper from McGovern Medical Schools department of pediatrics infectious diseases division included Aya Aboulhosn, MD; Misu A. Sanson-Iglesias, MD, PhD; Luis Alberto Vega, PhD; and Maria G. Segura, MD.