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DURHAM, N.C. -- Biomedical engineers at Duke University have devised an algorithm to remove contaminated microbial genetic information from The Cancer Genome Atlas (TCGA). With a clearer picture of the microbiota living in various organs in both healthy and cancerous states, researchers will now be able to find new biomarkers of disease and better understand how numerous cancers affect the human body.

In the first study using the newly decontaminated dataset, the researchers have already discovered that normal and cancerous organ tissues have a slightly different microbiota composition, that bacteria from these diseased sites can enter the bloodstream, and that this bacterial information could help diagnose cancer and predict patient outcomes.

The results appear online on December 30 in the journal Cell Host & Microbe.

TCGA is a landmark cancer genomics program that molecularly characterized over 20,000 primary cancer and matched healthy samples spanning 33 cancer types. It has produced more than 2.5 million gigabytes of "omic" data. The atlas includes which DNA is present, what epigenetic markers are on the DNA, which DNA is turned on and which proteins are being produced. It is freely available for public use.

One study from the atlas data revealed an abundance of Fusobacterium nucleatum in colorectal cancer, which has since been shown to be indicative of stage, survival, metastasis and even drug responses of this kind of cancer.
Many more studies have searched for such bacterial biomarkers, however few have been discovered. A large reason for this is contamination. When bacteria get introduced into the samples accidentally by the laboratories, it becomes difficult to discern which species were actually in the samples to begin with. While similar microbiome studies using microbe-rich material such as feces can overcome small amounts of contamination, the relatively miniscule samples taken from live human organs and tumor samples cannot.

When examining a subset of TCGA sequencing data, previous analyses found that microbial DNA from a number of species was the result of lab contamination.

"All microbiota studies are plagued by the notion that if you find a microbe, was it really in the tissue or was it contamination introduced during processing?" said Xiling Shen, the Hawkins Family Associate Professor of Biomedical Engineering at Duke. "We've invented a method that can extract the microbes that were truly in each sample and used it to build what we've called The Cancer Microbiome Atlas, which will be a tremendous resource for the community and allow us to understand how cancer alters an organ's microbiome."

The method for removing contamination from TCGA data was invented by Anders Dohlman, a graduate student in Shen's laboratory. Dohlman first compared the microbiome signatures between cancer tissues from different organs and blood, and ruled out contaminant species that showed up indiscriminately. He then compared the microbiome signatures of identical samples that were processed at separate sites, ranging from Harvard to Baylor. Dohlman concluded that the microbial species that can only be detected from a specific site would be the contaminants, allowing him to assign a unique contamination signature for each site.

"A big challenge in this process was mixed-evidence species, which are bacteria that are both a contaminant and endogenous to the tissue," said Dohlman. "But because TCGA has so many different types of data, we were able to tease it out. Big data really helps!"

The effort is already paying dividends in a variety of ways. After using Dohlman's decontamination algorithm, the researchers took a close look at the microbiota signatures of samples taken from colorectal cancer patients. They discovered two unique groups of bacteria frequently found together, one of which appears to be associated with patient survival.

The researchers also discovered that some cancers do indeed alter the microbiome of their resident organs. It might be, Shen reasons, that tumors alter an organ's microenvironment, making it more or less hospitable to different microbial species. And by looking for microbial signatures within patient blood samples, they also found that, despite conventional wisdom to the contrary, some bacteria does find its way into the bloodstream, which could also provide an indication of a cancer's progress.

"There has been a sort of crisis in the field about whether or not high-profile papers can be reproduced, owing to the challenge of contamination," said Shen. "For example, while one center would be able to reproduce its results, another center would not. This explains why: Each center has its own very consistent bias. (Its own resident microbe contaminants.) In the future, new studies can use our method to remove this bias and reproduce results, and research centers might be able to use their bias we've identified to mitigate their contamination."

Many students, especially non-science majors, dread chemistry. The first lesson in an introductory chemistry course typically deals with how to interpret the periodic table of elements, but its complexity can be overwhelming to students with little or no previous exposure. Now, researchers reporting in ACS' Journal of Chemical Education introduce an innovative way to make learning about the elements much more approachable -- by using "pseudo" periodic tables filled with superheroes, foods and apps.

One of the fundamental topics taught in first-year undergraduate chemistry courses is the organization and layout of the periodic table of elements. However, many university students consider it a daunting and difficult subject to master, prompting professors to seek new ways to engage their students and make its concepts more accessible. Previous educational studies presented the table in different formats, such as crossword puzzles and cartograms, to address multiple types of learning styles. Gregory Watson and colleagues reasoned that introducing the periodic table with familiar items could also help. And rather than teaching the full details right away, the researchers wanted to focus on some of its key characteristics first, using a contemporary, engaging and multi-level strategy.

The team presented first-year chemistry students with a series of made-up, or pseudo, periodic tables with objects that they had likely encountered before, including fruits and nuts, superheroes, iPad apps and meats. The pseudo periodic versions replaced elements with single items to demonstrate one or more concepts needed to understand the trends and layout of the real chemical one. For example, a superhero table featured characters, such as Superman, Wonder Woman and the Green Lantern, prompting in-class discussions on how to group the icons by ability, strength, gender and other properties -- just as the elements are arranged in the real periodic table based on their similarities. Over 75% of students taught with this strategy identified it as somewhat, very or extremely useful. An increase in correct answers relating to the subject on midterm exams suggested that these periodic tables improved students' comprehension. The researchers say that the familiar items reduce stress and help students successfully build their base of chemistry knowledge.

On April 15, 2020, a brief burst of high-energy light swept through the solar system, triggering instruments on several NASA and European spacecraft. Now, multiple international science teams conclude that the blast came from a supermagnetized stellar remnant known as a magnetar located in a neighboring galaxy.

This finding confirms long-held suspicions that some gamma-ray bursts (GRBs) - cosmic eruptions detected in the sky almost daily - are in fact powerful flares from magnetars relatively close to home.

"This has always been regarded as a possibility, and several GRBs observed since 2005 have provided tantalizing evidence," said Kevin Hurley, a Senior Space Fellow with the Space Sciences Laboratory at the University of California, Berkeley, who joined several scientists to discuss the burst at the virtual 237th meeting of the American Astronomical Society. "The April 15 event is a game changer because we found that the burst almost certainly lies within the disk of the nearby galaxy NGC 253."

Papers analyzing different aspects of the event and its implications were published on Jan. 13 in the journals Nature and Nature Astronomy.

GRBs, the most powerful explosions in the cosmos, can be detected across billions of light-years. Those lasting less than about two seconds, called short GRBs, occur when a pair of orbiting neutron stars - both the crushed remnants of exploded stars - spiral into each other and merge. Astronomers confirmed this scenario for at least some short GRBs in 2017, when a burst followed the arrival of gravitational waves - ripples in space-time - produced when neutron stars merged 130 million light-years away.

Magnetars are neutron stars with the strongest-known magnetic fields, with up to a thousand times the intensity of typical neutron stars and up to 10 trillion times the strength of a refrigerator magnet. Modest disturbances to the magnetic field can cause magnetars to erupt with sporadic X-ray bursts for weeks or longer.

Rarely, magnetars produce enormous eruptions called giant flares that produce gamma rays, the highest-energy form of light.

Most of the 29 magnetars now cataloged in our Milky Way galaxy exhibit occasional X-ray activity, but only two have produced giant flares. The most recent event, detected on Dec. 27, 2004, produced measurable changes in Earth's upper atmosphere despite erupting from a magnetar located about 28,000 light-years away.

Shortly before 4:42 a.m. EDT on April 15, 2020, a brief, powerful burst of X-rays and gamma rays swept past Mars, triggering the Russian High Energy Neutron Detector aboard NASA's Mars Odyssey spacecraft, which has been orbiting the Red Planet since 2001. About 6.6 minutes later, the burst triggered the Russian Konus instrument aboard NASA's Wind satellite, which orbits a point between Earth and the Sun located about 930,000 miles (1.5 million kilometers) away. After another 4.5 seconds, the radiation passed Earth, triggering instruments on NASA's Fermi Gamma-ray Space Telescope, as well as on the European Space Agency's INTEGRAL satellite and Atmosphere-Space Interactions Monitor (ASIM) aboard the International Space Station.

The eruption occurred beyond the field of view of the Burst Alert Telescope (BAT) on NASA's Neil Gehrels Swift Observatory, so its onboard computer did not alert astronomers on the ground. However, thanks to a new capability called the Gamma-ray Urgent Archiver for Novel Opportunities (GUANO), the Swift team can beam back BAT data when other satellites trigger on a burst. Analysis of this data provided additional insight into the event.

The pulse of radiation lasted just 140 milliseconds - as fast as the blink of an eye or a finger snap.

The Fermi, Swift, Wind, Mars Odyssey and INTEGRAL missions all participate in a GRB-locating system called the InterPlanetary Network (IPN). Now funded by the Fermi project, the IPN has operated since the late 1970s using different spacecraft located throughout the solar system. Because the signal reached each detector at different times, any pair of them can help narrow down a burst's location in the sky. The greater the distances between spacecraft, the better the technique's precision.

The IPN placed the April 15 burst, called GRB 200415A, squarely in the central region of NGC 253, a bright spiral galaxy located about 11.4 million light-years away in the constellation Sculptor. This is the most precise sky position yet determined for a magnetar located beyond the Large Magellanic Cloud, a satellite of our galaxy and host to a giant flare in 1979, the first ever detected.

Giant flares from magnetars in the Milky Way and its satellites evolve in a distinct way, with a rapid rise to peak brightness followed by a more gradual tail of fluctuating emission. These variations result from the magnetar's rotation, which repeatedly brings the flare location in and out of view from Earth, much like a lighthouse.

Observing this fluctuating tail is conclusive evidence of a giant flare. Seen from millions of light-years away, though, this emission is too dim to detect with today's instruments. Because these signatures are missing, giant flares in our galactic neighborhood may be masquerading as much more distant and powerful merger-type GRBs.

A detailed analysis of data from Fermi's Gamma-ray Burst Monitor (GBM) and Swift's BAT provides strong evidence that the April 15 event was unlike any burst associated with mergers, noted Oliver Roberts, an associate scientist at Universities Space Research Association's Science and Technology Institute in Huntsville, Alabama, who led the study.

In particular, this was the first giant flare known to occur since Fermi's 2008 launch, and the GBM's ability to resolve changes at microsecond timescales proved critical. The observations reveal multiple pulses, with the first one appearing in just 77 microseconds - about 13 times the speed of a camera flash and nearly 100 times faster than the rise of the fastest GRBs produced by mergers. The GBM also detected rapid variations in energy over the course of the flare that have never been observed before.

"Giant flares within our galaxy are so brilliant that they overwhelm our instruments, leaving them to hang onto their secrets," Roberts said. "For the first time, GRB 200415A and distant flares like it allow our instruments to capture every feature and explore these powerful eruptions in unparalleled depth."

Giant flares are poorly understood, but astronomers think they result from a sudden rearrangement of the magnetic field. One possibility is that the field high above the surface of the magnetar may become too twisted, suddenly releasing energy as it settles into a more stable configuration. Alternatively, a mechanical failure of the magnetar's crust - a starquake - may trigger the sudden reconfiguration.

Roberts and his colleagues say the data show some evidence of seismic vibrations during the eruption. The highest-energy X-rays recorded by Fermi's GBM reached 3 million electron volts (MeV), or about a million times the energy of blue light, itself a record for giant flares. The researchers say this emission arose from a cloud of ejected electrons and positrons moving at about 99% the speed of light. The short duration of the emission and its changing brightness and energy reflect the magnetar's rotation, ramping up and down like the headlights of a car making a turn. Roberts describes it as starting off as an opaque blob - he pictures it as resembling a photon torpedo from the "Star Trek" franchise - that expands and diffuses as it travels.

The torpedo also factors into one of the event's biggest surprises. Fermi's main instrument, the Large Area Telescope (LAT), also detected three gamma rays, with energies of 480 MeV, 1.3 billion electron volts (GeV), and 1.7 GeV - the highest-energy light ever detected from a magnetar giant flare. What's surprising is that all of these gamma rays appeared long after the flare had diminished in other instruments.

Nicola Omodei, a senior research scientist at Stanford University in California, led the LAT team investigating these gamma rays, which arrived between 19 seconds and 4.7 minutes after the main event. The scientists conclude that this signal most likely comes from the magnetar flare. "For the LAT to detect a random short GRB in the same region of the sky and at nearly the same time as the flare, we would have to wait, on average, at least 6 million years," he explained.

A magnetar produces a steady outflow of fast-moving particles. As it moves through space, this outflow plows into, slows, and diverts interstellar gas. The gas piles up, becomes heated and compressed, and forms a type of shock wave called a bow shock.

In the model proposed by the LAT team, the flare's initial pulse of gamma rays travels outward at the speed of light, followed by the cloud of ejected matter, which is moving nearly as fast. After several days, they both reach the bow shock. The gamma rays pass through. Seconds later, the cloud of particles - now expanded into a vast, thin shell - collides with accumulated gas at the bow shock. This interaction creates shock waves that accelerate particles, producing the highest-energy gamma rays after the main burst.

The April 15 flare proves that these events constitute their own class of GRBs. Eric Burns, an assistant professor of physics and astronomy at Louisiana State University in Baton Rouge, led a study investigating additional suspects using data from numerous missions. The findings will appear in The Astrophysical Journal Letters. Bursts near the galaxy M81 in 2005 and the Andromeda galaxy (M31) in 2007 had already been suggested to be giant flares, and the team additionally identified a flare in M83, also seen in 2007 but newly reported. Add to these the giant flare from 1979 and those observed in our Milky Way in 1998 and 2004.

"It's a small sample, but we now have a better idea of their true energies, and how far we can detect them," Burns said. "A few percent of short GRBs may really be magnetar giant flares. In fact, they may be the most common high-energy outbursts we've detected so far beyond our galaxy - about five times more frequent than supernovae."

KANSAS CITY, MO--What if the degenerative eye conditions that lead to glaucoma, corneal dystrophy, and cataracts could be detected and treated before vision is impaired? Recent findings from the lab of Investigator Ting Xie, PhD, at the Stowers Institute for Medical Research point to the ciliary body as a key to unlocking this possibility.

Previous work from the lab showed that when mouse stem cells were differentiated into light-sensing photoreceptor cells in vitro, and then transplanted back into mice with a degenerative condition of the retina, they could partially restore vision. However, the transplanted photoreceptors only lasted three to four months.

"You cannot cure the condition in a diseased eye if you don't know what causes the disease," says Xie. "This has been a major hurdle for stem cell therapy in treating degenerative diseases."

To this end, Xie's group began to study the eye tissue microenvironment, specifically a specialized tissue in the eye called the ciliary body. Located at the posterior edge of the iris, it is known to maintain ocular pressure by secreting aqueous humor, the clear fluid between the lens and the cornea. It has a similar function in mice and in humans, and defects in the ciliary body manifest in similar ways in the mouse and human eye.

"People think the ciliary body is boring," says Xie. This might be because the ciliary body was once thought to have a reserve of retinal stem cells, Xie explains, which turned out not to be true. However, its role in eye biology turns out to be quite broad, and "without a functioning ciliary body, the eye degenerates," Xie adds.

When the Notch signaling pathway--an important cell signaling system found across the animal kingdom--is defective in the ciliary bodies of newly born mice, they fail to develop folds, and secretions decrease, leading to shrunken vitreous bodies. In adult mice, defects in Notch signaling cause low eye pressure, a shrunken vitreous, and eye degeneration. Inactivation of the downstream transcription factor RBPJ in the ciliary body also leads to the same effects. Before now, the underlying molecular mechanism for this outcome was unclear.

In a paper published in Cell Reports on January 12, 2021, first author Ji Pang, a visiting PhD student from Shanghai Jiao Tong University, China, and others describe a signaling pathway wherein Notch and Nectin proteins in the ciliary body function in the development and maintenance of eye tissue and structure.

In this report, the researchers describe the roles of adhesion protein Nectin1 and gap junction protein Connexin43 in the ciliary body of mice. They found that Notch2/3-Rbpj signaling in the outer ciliary epithelium controls the expression of Nectin1, which works with Nectin3 in the inner ciliary epithelium to keep the two tissue layers together, which promotes proper folding of the ciliary body. They found that Notch signaling also maintains the expression of Connexin43 in the outer ciliary epithelium, while Nectin1 localizes and stabilizes Connexin43 on the lateral surface, which maintains the vitreous body and intraocular pressure.

Lastly, the researchers found that in addition to maintaining ocular pressure and directing ciliary body morphogenesis, Notch2/3-Rbpj signaling in the inner ciliary epithelium also regulates the secretion of various proteins such as Opticin and collagens into the vitreous body, providing nutritive support for the cornea, the lens, and the retina.

"We propose the ciliary body could be a niche for the eye tissues," explains Xie, in the sense that it can behave like a stem cell niche, by providing signals that affect cellular morphogenesis and function. "The next important question is what other protein factors secreted by the ciliary body are important for maintaining the cornea, the lens, and the retina, respectively. Some of these factors could be involved directly in eye diseases."

TROY, N.Y. -- Blood sample analysis showed that, two to five years after they gave birth, mothers of children with autism spectrum disorder (ASD) had several significantly different metabolite levels compared to mothers of typically developing children. That's according to new research recently published in BMC Pediatrics by a multidisciplinary team from Rensselaer Polytechnic Institute, Arizona State University, and the Mayo Clinic.

Researchers analyzed blood samples from 30 mothers whose young children had been diagnosed with ASD and 29 mothers of typically developing children. At the time that the samples were taken, the women's children were between 2 and 5 years old. The team found differences in several metabolite levels between the two groups of mothers. When examined further, researchers were able to group those differences into five subgroups of correlated metabolites. While the samples analyzed were taken several years after pregnancy, these research findings raise the question of whether or not the differences in metabolites may have been present during pregnancy as well, suggesting further research is needed in this area.

Many of the variances, the researchers said, were linked to low levels of folate, vitamin B12, and carnitine-conjugated molecules. Carnitine can be produced by the body and can come from meat sources like pork or beef, but there wasn't a correlation between mothers who ate more meat and mothers who had higher levels of carnitine.

According to Juergen Hahn, the head of the Department of Biomedical Engineering at Rensselaer and co-author on this paper, this finding suggests that the differences may be related to how carnitine is metabolized in some mothers' bodies.

"We had multiple metabolites that were associated with the carnitine metabolism," said Hahn, who is also a member of the Center for Biotechnology and Interdisciplinary Studies at Rensselaer. "This suggests that carnitine and mothers is something that should be looked at."

The team's big data approach proved to be highly accurate in using a blood sample analysis to predict which group a mother belonged to, which suggests that the development of a blood test to screen for mothers who are at a higher risk of having a child with ASD may be possible.

"A blood test would not be able to tell if your child has autism or not, but it could tell if you're at a higher risk," Hahn said. "And the classification of higher risk, in this case, can actually be significant."

"Based on these results, we are now conducting a new study of stored blood samples collected during pregnancy, to determine if those metabolites are also different during pregnancy," said James Adams, a President's Professor in the School of Engineering of Matter, Transport and Energy, and director of the Autism/Asperger's Research Program, both at Arizona State University. Adams co-authored this paper with Hahn.

This research builds upon Hahn's other work. He previously discovered patterns with certain metabolites in the blood of children with autism that can be used to successfully predict diagnosis. He has used this same method to investigate a mother's risk for having a child with ASD. He and Adams have also done similar work studying children with autism who have chronic gastrointestinal issues.

Skoltech researchers have found a way to use chemical sensors and computer vision to determine when grilled chicken is cooked just right. These tools can help restaurants monitor and automate cooking processes in their kitchens, and perhaps one day even end up in your 'smart' oven. The paper detailing this research results, supported by a Russian Science Foundation grant, was published in the journal Food Chemistry.

How do you tell that chicken breast on your grill is ready for your plate? You probably look at it closely and smell it to make sure it is done the way you like it. However, if you are a restaurant chef or head cook at a huge industrial kitchen, you cannot really rely on your eyes and nose to ensure uniform results up to the standards your customers expect. That is why the hospitality industry is actively looking for cheap, reliable, and sensitive tools to replace subjective human judgment with automated quality control.

Professor Albert Nasibulin of Skoltech and Aalto University, Skoltech senior research scientist Fedor Fedorov and their colleagues decided to do just that: get an 'e-nose,' an array of sensors detecting certain components of an odor, to 'sniff' the cooking chicken and a computer vision algorithm to 'look' at it. 'E-noses' are simpler and less expensive to operate than, say, a gas chromatograph or a mass spectrometer, and they have even been shown to be able to detect various types of cheeses or pick out rotten apples or bananas. On the other hand, computer vision can recognize visual patterns - for instance, to detect cracked cookies.

The Skoltech Laboratory of Nanomaterials, led by Professor Nasibulin, has been developing new materials for chemical sensors; one of the applications for these sensors is in the HoReCa segment, as they can be used to control the quality of air filtration in restaurant ventilation. A student of the lab and co-author of the paper, Ainul Yaqin, traveled to Novosibirsk for his Industrial Immersion project. He used the lab sensors to test the effectiveness of industrial filters produced by a major Russian company. That project led to experiments with the smell profile of grilled chicken.

"At the same time, to determine the proper doneness state, one cannot rely on 'e-nose' only but have to use computer vision -- these tools give you a so-called 'electronic panel' (a panel of electronic 'experts'). Building on the great experience in computer vision techniques of our colleagues from Skoltech CDISE, together, we tested the hypothesis that, when combined, computer vision and electronic nose provide more precise control over the cooking," Nasibulin says.

The team chose to combine these two techniques to monitor the doneness of food accurately and in a contactless manner. They picked chicken meat, which is popular across the world, and grilled quite a lot of chicken breast (bought at a local Moscow supermarket) to 'train' their instruments to evaluate and predict how well it was cooked.

The researchers built their own 'e-nose,' with eight sensors detecting smoke, alcohol, CO, and other compounds and temperature and humidity, and put it into the ventilation system. They also took photos of the grilled chicken and fed the information to an algorithm that specifically looks for data patterns. To define changes in odor consistent with the various stages of a grilling process, scientists used thermogravimetric analysis (to monitor the number of volatile particles for the 'e-nose' to detect), differential mobility analysis to measure the size of aerosol particles, and mass spectrometry.

But perhaps the most important part of the experiment involved 16 PhD students and researchers who taste-tested a lot of grilled chicken breast to rate its tenderness, juiciness, intensity of flavor, appearance, and overall doneness on a 10-point scale. This data was matched to the analytical results to test the latter against humans' perception who usually end up eating the chicken.

The researchers grilled meat just outside the lab and used the Skoltech canteen to set up the testing site. "Due to the COVID-19 pandemic, we had to wear masks and perform testing in small groups, so it was a rather unusual experience. All participants were given instructions and provided with sensory evaluation protocols to do the job properly. We cooked many samples, coded them, and used them in blind tests. It was an exciting experience for material scientists mainly and relied on data from sophisticated analytical tools. But, chicken tissues are materials too," Fedorov notes.

The team reports that their system was able to identify undercooked, well-cooked, and overcooked chicken quite well, so it can potentially automate quality control in a kitchen setting. The authors note that to use their technique on other parts of the chicken - say, legs or wings - or for a different cooking method, the electronic 'nose' and 'eyes' would have to be retrained on new data.

The researchers now plan to test their sensors in restaurant kitchen environments. One other potential application could be 'sniffing out' rotten meat at the very early stages when changes in its smell profile would still be too subtle for a human nose.

"We believe these systems can be integrated into industrial kitchens and even in usual kitchens as a tool that can help and advise about the doneness degree of your meat, when direct temperature measurement is not possible or not effective," Fedor Fedorov says.

Scientists tame photon-magnon interaction.

Working with theorists in the University of Chicago’s Pritzker School of Molecular Engineering, researchers in the U.S. Department of Energy’s (DOE) Argonne National Laboratory have achieved a scientific control that is a first of its kind. They demonstrated a novel approach that allows real-time control of the interactions between microwave photons and magnons, potentially leading to advances in electronic devices and quantum signal processing.

Microwave photons are elementary particles forming the electromagnetic waves that we use for wireless communications. On the other hand, magnons are the elementary particles forming what scientists call “spin waves” — wave-like disturbances in an ordered array of microscopic aligned spins that can occur in certain magnetic materials.

“Before our discovery, controlling the photon-magnon interaction was like shooting an arrow into the air. One has no control at all over that arrow once in flight.” — Xufeng Zhang, assistant scientist in Argonne’s Center for Nanoscale Materials

Microwave photon-magnon interaction has emerged in recent years as a promising platform for both classical and quantum information processing. Yet, this interaction had proved impossible to manipulate in real time, until now.

“Before our discovery, controlling the photon-magnon interaction was like shooting an arrow into the air,” said Xufeng Zhang, an assistant scientist in the Center for Nanoscale Materials, a DOE User Facility at Argonne, and the corresponding author of this work. “One has no control at all over that arrow once in flight.”

The team’s discovery has changed that. “Now, it is more like flying a drone, where we can guide and control its flight electronically,” said Zhang.

By smart engineering, the team employs an electrical signal to periodically alter the magnon vibrational frequency and thereby induce effective magnon-photon interaction. The result is a first-ever microwave-magnonic device with on-demand tunability.

The team’s device can control the strength of the photon-magnon interaction at any point as information is being transferred between photons and magnons. It can even completely turn the interaction on and off. With this tuning capability, scientists can process and manipulate information in ways that far surpass present-day hybrid magnonic devices.

“Researchers have been searching for a way to control this interaction for the past few years,” noted Zhang. The team’s discovery opens a new direction for magnon-based signal processing and should lead to electronic devices with new capabilities. It may also enable important applications for quantum signal processing, where microwave-magnonic interactions are being explored as a promising candidate for transferring information between different quantum systems.

Tsukuba, Japan - Work causes so much stress that it's become a global public health issue. Stress's impact on mental and physical health can also hurt productivity and result in economic loss. A new study now finds that working people who regularly take walks in forests or greenspaces may have higher stress-coping abilities.

In a study published in Public Health in Practice, researchers led by Professor Shinichiro Sasahara at the University of Tsukuba analyzed workers' "sense of coherence" (SOC) scores, demographic attributes, and their forest/greenspace walking habits. SOC comprises the triad of meaningfulness (finding a sense of meaning in life), comprehensibility (recognizing and understanding stress), and manageability (feeling equipped to deal with stress). Studies have found factors such as higher education and being married can strengthen SOC, while smoking and not exercising can weaken it. People with strong SOC also have greater resilience to stress.

The study used survey data on more than 6,000 Japanese workers between 20 and 60 years old. It found stronger SOC among people who regularly took walks in forests or greenspaces.

"SOC indicates mental capacities for realizing and dealing with stress," Professor Sasahara says. "With workplace stress as a focal issue, there's a clear benefit in identifying everyday activities that raise SOC. It seems we may have found one."

People find comfort in nature, and in countries like Japan urban greenspaces are increasing in popularity where nature isn't readily accessible. This means many workers in cities can easily take a walk among the trees.

The researchers divided the survey respondents into four groups based on their frequency of forest/greenspace walking. Then, they compared their walking activity against attributes such as age, income, and marital status, and with the respondents' SOC scores, which were grouped as weak, middle, and strong.

Those with strong SOC showed a significant correlation with both forest and greenspace walking at least once a week. This key finding implies the greater benefits of urban greening--not just environmental, but also socioeconomic.

"Our study suggests that taking a walk at least once a week in a forest or greenspace can help people have stronger SOC," explains Professor Sasahara. "Forest/greenspace walking is a simple activity that needs no special equipment or training. It could be a very good habit for improving mental health and managing stress."

Stiffness in our tissues causes tension in our cells. Research from the Buck Institute, the University Health Network (University of Toronto), Stanford University, and the University of Alberta shows that stiffness impacts the innate immune system by upping its metabolism. The findings suggest the cellular tension likely sets off an inflammatory loop that contributes to the development of chronic diseases of aging. Publishing in Cell Reports, Buck Associate Professor Dan Winer, MD, and colleagues present an emerging way of looking at how the immune system functions, possibilities for new immunotherapeutics, and a call for scientists to reconsider the way they do research.

While stiffness is a recognized factor in acute infections (think swollen lymph glands or swelling after a cut), Winer is particularly focused on how stiffness that arises from the environment impacts immune cells. "While viruses and bacteria are key players in triggering an immune response, we think that the forces in the environment around the cells are an extremely important part of the puzzle that influences immunity," he said. "Stiffness in our tissues and the resulting cellular tension changes in most diseases, as well as in aging itself," said Winer. "This work provides support for a new way of thinking about how the immune system functions, suggesting that mechanical force primes and likely controls immunology during acute and chronic disease because it readies the immune system in the face of danger."

Winer and his team, led by Mainak Chakraborty, MSc, Research Assistant at the University Health Network in Toronto and Sue Tsai, a former post-doctoral fellow in the lab, now an Assistant Professor at the University of Alberta, cultured dendritic cells (DCs), a component of the innate immune system that orchestrates an immune response, from mouse bone marrow and spleen at different degrees of physiological stiffness. "DCs grown at physiological resting stiffness showed reduced proliferation, activation and cytokine production compared to cells grown under high stiffness which mimicked fibro-inflammatory disease," said Chakraborty. "High stiffness grown DCs showed increased activation and flux in major glucose metabolic pathways," added Tsai. "In models of autoimmune diabetes and tumor immunotherapy, the cellular tension primed the DCs to elicit a response from the adaptive immune system, which kicks in specifically and secondarily following infection or injury." The findings were not limited to mouse DCs, as human DCs also showed enhanced markers of activity under higher tension.

Researchers identified the Hippo-signaling molecule, TAZ, as an important factor impacting DC metabolism and function under tension in the innate immune response. Winer says that finding is significant, given that a lab at the University of California, Los Angeles recently showed that same pathway facilitated the effects of tension in the adaptive immune system. "This seems to be a critical pathway for sensing environmental force in both arms of the immune system," said Winer. "Mechanoimmunology still has been understudied. We hope our work moves this emerging field forward and leads to the development of new force-targeting immunotherapies that would allow the immune system to function normally across the many conditions that alter tissue stiffness."

Big implications for killer diseases and chronic diseases of aging

Winer says there are number of diseases predicted to be influenced by the impact of tissue stiffness on the immune system. "Heart disease, cancer and lower lung disease are among the top causes of death in the U.S.," he said. "Computer algorithms from our study show that all of these conditions are strongly modulated by genes or protein interactions that are induced by tension in the immune system. Those studying these diseases should consider this finding."

Noting that tissue stiffness is a well-known phenomenon associated with aging (for instance, the lungs and their blood vessels can double in stiffness with age), Winer says it's likely that the interaction with the immune system contributes to the low-grade chronic inflammation that fuels many of the diseases of aging. "The tension from the stiffness promotes metabolism and cytokine production in DCs which may potentially contribute to what is now known as inflammaging." Winer says his lab plans on looking at mechanoimmunology in aging mice and in the context of specific diseases.

Winer says the genes that are activated via cellular tension are potential targets for immunotherapeutics, which is another focus in his lab. He says techniques now exist (via an add-on to Magnetic Resonance Imaging or ultrasound) that enable the mapping of tension in specific tissues and organs. Winer says the ability to track the tension could provide a biomarker of aging and make it easier to test new drugs.

A final note to researchers: Be wary of culturing on plastic!

Almost as important as the findings in this study, Winer is urging researchers to consider changing the way they culture immune cells. He says for decades the vast majority of scientists have been using plastic plates to grow their cells, which exerts tension thousands of times higher than what a cell feels in the body. "Many immune cells need to anchor themselves in the dish and the stiffness of the plastic imparts supraphysiological force on the cells" he said. Winer's team grows immune cells on soft silicone gels which have been treated to closely mimic the physiology inside the body. "We think adopting new research culturing techniques in immunology might better mimic the physiology inside the body."

You are likely familiar with the serious consequences of anorexia for those who experience it, but you might not be aware that the disorder may not be purely psychological. A recent review from researchers at the University of Oxford in the open-access journal
Frontiers in Psychiatry examines the evidence that gut microbes could play a significant role in anorexia by affecting appetite, weight, and psychiatric issues such as anxiety and compulsive behavior, among others. Intriguingly, the study also examines the potential for microbial treatments for anorexia, but highlights that we are just beginning to understand the complex relationship between gut microbes and disease.

"Anorexia nervosa is a very common psychiatric disorder and can be incredibly debilitating or even fatal, but is unfortunately still quite challenging to treat," explained Ana Ghenciulescu, lead author of the review. "Moreover, there has been a great deal of recent excitement about the idea that gut microbes affect many aspects of our health, including our mental health - and that this relationship goes both ways."

Recent research has examined these questions in the context of anorexia, and Ghenciulescu and colleagues combed the literature to summarize these findings. "In anorexia, microbial communities seem to be less diverse and more abundant in 'harmful' species," said Dr Phil Burnet, the senior researcher on the review.

For instance, previous research has shown that anorexia patients may have more bacteria that digest the protective mucus layer of the gut, making the gut 'leaky' and contributing to chronic inflammation, which is associated with psychiatric symptoms. Other microbes found in anorexia may affect appetite and energy metabolism, both of which can contribute to anorexia.

However, it is difficult to tell whether the microbial imbalance in anorexia patients contributes to the disease, or whether it is simply an effect of their dramatically restricted diet. This chicken and egg situation is a puzzle, but studies in mice may shed some light on the situation. While the experiments may seem a little strange, as they rely on the most readily available source of gut microbes, feces, the results are compelling.

"In a mouse study, researchers transferred fecal samples from anorexia patients to the guts of mice with no microbiome of their own," said Ghenciulescu. "Such mice gained less weight and developed more anxious and compulsive behaviors compared with mice who received feces from healthy patients. This suggests that their altered gut bacteria might be contributing to similar symptoms in anorexia patients as well."

While these results are preliminary, they hint at the intriguing possibility that targeting the microbiome could be a viable treatment for anorexia. Promoting and maintaining a better microbial balance may help to reduce some of the symptoms of anorexia.

So, what might such treatments look like? It could as simple as taking probiotic supplements, or may involve fecal transplants. However, the review highlights that our understanding of the relationship between gut microbes and anorexia is very much in its infancy. "There is still no consensus over what a 'healthy' microbiome profile looks like, and the optimal composition is probably different for each person," said Burnet. "Much more work needs to be done to understand the rich and highly complex microbial ecosystem within our gut."

WASHINGTON, January 12, 2021 -- Sodium-ion batteries are a potential replacement for lithium batteries, but the anodes -- positively charged electrodes -- that work well for lithium-ion batteries don't provide the same level of performance for sodium-ion batteries.

Amorphous carbon, which lacks a crystalline structure, is known to be a useful anode, because it has defects and voids that can be used to store sodium ions. Nitrogen/phosphorus-doped carbon also offers appealing electrical properties.

In Applied Physics Reviews, from AIP Publishing, researchers in China from Zhejiang University, Ningbo University, and Dongguan University of Technology describe how they applied basic physical concepts of atomic scale to build high-performance anodes for sodium-ion batteries.

"Recent studies have shown that doped amorphous carbon, especially electron-rich element-doped amorphous carbon, is a good anode for sodium storage," said Tu. "But there was no common explanation for how sodium storage works or the doping effect of doped carbon."

On a quest for answers, the researchers used the concept of energy level orbitals to explain the affinity of pyrrolic nitrogen and a phosphorus-oxygen bond, their atomic interaction, electron distribution, and electron cloud configuration.

To get a closer look at distinct storage behavior, they applied first principles calculations, which is a method that uses basic physical quantities to calculate physical properties. It is based on electron density function, a concept of quantum mechanics that can reveal a crystal's molecular structure.

When they analyzed the electron distribution, system chemical parameters, and adsorption energies of sodium ions embedded within modified carbon materials, they found that pyrrolic nitrogen and phosphorus-oxygen bonds show real potential for sodium storage.

"Sodium ions tend to be stored within these two structures," Tu said.

The researchers designed a hydrothermal treatment to build the precursor of a phosphorus-oxygen structure, then doped a carbon anode with the dual electron-rich elements. It shows "enhanced electrochemical performance in cycle life and capacity for batteries," said Tu.

Their anode achieved a life cycle of 5,000 cycles, with an enhanced capacity of 220 milliampere hours/gram, and reduced capacity loss (0.003%/cycle).

"Our work fills the theoretical gap about the sodium storage behavior of electron-rich element-doped amorphous carbon and provides the experimental basis for using carbon," said Tu. "We provide directions to modify carbon materials for large-scale sodium-ion batteries."

Imagine you gave the exact same art pieces to two different groups of people and asked them to curate an art show. The art is radical and new. The groups never speak with one another, and they organize and plan all the installations independently. On opening night, imagine your surprise when the two art shows are nearly identical. How did these groups categorize and organize all the art the same way when they never spoke with one another?

The dominant hypothesis is that people are born with categories already in their brains, but a study from the Network Dynamics Group (NDG) at the Annenberg School for Communication has discovered a novel explanation. In an experiment in which people were asked to categorize unfamiliar shapes, individuals and small groups created many different unique categorization systems while large groups created systems nearly identical to one another.

"If people are all born seeing the world the same way, we would not observe so many differences in how individuals organize things," says senior author Damon Centola, Professor of Communication, Sociology, and Engineering at the University of Pennsylvania. "But this raises a big scientific puzzle. If people are so different, why do anthropologists find the same categories, for instance for shapes, colors, and emotions, arising independently in many different cultures? Where do these categories come from and why is there so much similarity across independent populations?"

To answer this question, the researchers assigned participants to various sized groups, ranging from 1 to 50, and then asked them to play an online game in which they were shown unfamiliar shapes that they then had to categorize in a meaningful way. All of the small groups invented wildly different ways of categorizing the shapes. Yet, when large groups were left to their own devices, each one independently invented a nearly identical category system.

"If I assign an individual to a small group, they are much more likely to arrive at a category system that is very idiosyncratic and specific to them," says lead author and Annenberg alum Douglas Guilbeault (Ph.D. '20), now an Assistant Professor at the Haas School of Business at the University of California, Berkeley. "But if I assign that same individual to a large group, I can predict the category system that they will end up creating, regardless of whatever unique viewpoint that person happens to bring to the table."

"Even though we predicted it," Centola adds, "I was nevertheless stunned to see it really happen. This result challenges many long—held ideas about culture and how it forms."

The explanation is connected to previous work conducted by the NDG on tipping points and how people interact within networks. As options are suggested within a network, certain ones begin to be reinforced as they are repeated through individuals' interactions with one another, and eventually a particular idea has enough traction to take over and become dominant. This only applies to large enough networks, but according to Centola, even just 50 people is enough to see this phenomenon occur.

Centola and Guilbeault say they plan to build on their findings and apply them to a variety of real—world problems. One current study involves content moderation on Facebook and Twitter. Can the process of categorizing free speech versus hate speech (and thus what should be allowed versus removed) be improved if done in networks rather than by solitary individuals? Another current study is investigating how to use network interactions among physicians and other health care professionals to decrease the likelihood that patients will be incorrectly diagnosed or treated due to prejudice or bias, like racism or sexism. These topics are explored in Centola's forthcoming book, CHANGE: How to Make Big Things Happen (Little, Brown & Co., 2021).

"Many of the worst social problems reappear in every culture, which leads some to believe these problems are intrinsic to the human condition," says Centola. "Our research shows that these problems are intrinsic to the social experiences humans have, not necessarily to humans themselves. If we can alter that social experience, we can change the way people organize things, and address some of the world's greatest problems."

Producing clean energy and reducing the power consumption of illumination and personal devices are key challenges to reduce the impact of modern civilization on the environment. As a result, the surging demand for solar cells and light-emitting devices is driving scientists to explore new semiconductor materials and improve their performances, while lowering the production costs.

Semiconductor nanocrystals (materials with sizes about 10 nanometers, which is approximately 10,000 times thinner than our hair) hold great promise for these applications: they are cheap to produce, can be easily integrated in these devices and possess exceptionally enhanced properties upon interaction with the light, as compared to their bulk counterparts. This strong coupling with light gives them a distinctive edge over conventional semiconductors, thus paving the way to high efficiency devices.

Unfortunately, this edge comes at a cost: when the size of a semiconductor is reduced, electrons can no longer travel freely across the material constrained by their physical dimensions. Furthermore, their much larger surfaces necessitate the use of passivation strategies (e.g., with organic ligands) to reduce the traps that could inadvertently affect the charge transport even further. Therefore, practical wide-spread applications of nanocrystals are limited, and their disruptive potential cannot be exploited.

In a new paper published in Light: Science & Application, a team of scientists, led by Professor Tze Chien Sum from Nanyang Technological University (NTU), Singapore, have discovered that nanocrystals made of halide perovskites possess extraordinary properties of energy transport, which replace the transport of charges, and could open new venues for implementing these materials in high efficiency devices.

Prof. Sum and his team have already pioneered the study of charge transport in these materials. In 2013 the team reported unprecedented electron transport properties for bulk halide perovskites and this discovery underpinned the successes of halide perovskites in the following years.

In this work, Prof. Sum's team demonstrated that surprisingly energy can be transported very efficiently in films made of nanocrystals. The team used a microscopy imaging system to "visualize" the energy traveling using their strong light-emission as a probe, as shown in Figure 1.

While negative and positive charges (electrons and holes, respectively) alone cannot travel inside this nanostructured material, they can team up and form so-called "excitons" to travel together, as shown in the Figure 2. The energy mobility in these materials exceeds that of other conventional nanostructures, such as Cadmium Selenide (CdSe) quantum dots by more than 1 order of magnitude. Moreover, energy can even travel in these materials further compared to what charges can do in bulk halide perovskites.

"This result is unprecedented. When you reduce the size of a material, usually it means you reduce the maximum distance that the charges can travel inside it. However, in halide perovskites, when you reduce their dimension to quantum size, these charges manage to arrange themselves into excitons and find a different way to travel. Their range now is even for longer distance than their initial travel range before you reduce their sizes!" said Dr. David Giovanni and Dr. Marcello Righetto, two of the lead authors of the work who shared equal contributions.

Here, two energy transport mechanisms were identified: the excitons "jump" very effectively between different nanocrystals, and their transport is assisted by emission light being trapped within the film and therefore reabsorbed. For the first time, scientist provided a method to distinguish these two contributions.

While the next challenge to directly implement these extraordinary properties for actual devices still remains (i.e., excitons have to be split in positive and negative charges to create a detectable current), this discovery of long-range energy transport and their mechanisms provide new ways of exploiting nanostructures into devices.

Scientists at Japan's Nagoya University and the National Institute for Materials Science have found that a simple one-drop approach is cheaper and faster for tiling functional nanosheets together in a single layer. If the process, described in the journal ACS Nano, can be scaled up, it could advance development of next-generation oxide electronics.

"Drop casting is one of the most versatile and cost-effective methods for depositing nanomaterials on a solid surface," says Nagoya University materials scientist Minoru Osada, the study's corresponding author. "But it has serious drawbacks, one being the so-called coffee-ring effect: a pattern left by particles once the liquid they are in evaporates. We found, to our great surprise, that controlled convection by a pipette and a hotplate causes uniform deposition rather than the ring-like pattern, suggesting a new possibility for drop casting."

The process Osada describes is surprisingly simple, especially when compared to currently available tiling techniques, which can be costly, time-consuming, and wasteful. The scientists found that dropping a solution containing 2D nanosheets with a simple pipette onto a substrate heated on a hotplate to a temperature of about 100°C, followed by removal of the solution, causes the nanosheets to come together in about 30 seconds to form a tile-like layer.

Analyses showed that the nanosheets were uniformly distributed over the substrate's surface, with limited gaps. This is probably a result of surface tension driving how particles disperse, and the shape of the deposited droplet changing as the solution evaporates.

The scientists used the process to deposit particle solutions of titanium dioxide, calcium niobate, ruthenium oxide, and graphene oxide. They also tried different sizes and shapes of a variety of substrates, including silicon, silicon dioxide, quartz glass, and polyethylene terephthalate (PET). They found they could control the surface tension and evaporation rate of the solution by adding a small amount of ethanol.

Furthermore, the team successfully used this process to deposit multiple layers of tiled nanosheets, fabricating functional nanocoatings with various features: conducting, semiconducting, insulating, magnetic and photochromic.

"We expect that our solution-based process using 2D nanosheets will have a great impact on environmentally benign manufacturing and oxide electronics," says Osada. This could lead to next-generation transparent and flexible electronics, optoelectronics, magnetoelectronics, and power harvesting devices.

Silicon carbide (SiC), a versatile and resistant material that exists in multiple crystalline forms, has attracted much attention thanks to its unique electronic properties. From its use in the first LED devices, to its applications in high-voltage devices with low power losses, SiC displays exceptional semiconductor behavior. So far, the operating voltages for unipolar SiC devices are below 3.3 kV. Though useful for the electronic systems of cars, trains, and home appliances, unipolar SiC-based devices cannot be used in power generation and distribution systems, which operate at voltages above 10 kV.

Some researchers believe that the solution to this conundrum lies in bipolar SiC devices, which offer low on-resistance (and hence lower losses) through conductivity modulation. However, the conductivity modulation effect is tightly related to the lifetime of excited charge carriers in the semiconductor; longer carrier lifetimes in the thick voltage blocking layer of SiC devices lead to increased modulation. On the other hand, excessively long carrier lifetimes increase the switching losses, and this trade-off has to be appropriately balanced by accurately controlling the distribution of carrier lifetimes within the semiconductor.

Unfortunately, most available techniques for measuring the carrier lifetime distribution of a semiconductor are destructive; the sample has to be cut for its cross-section to be analyzed. This motivated a research team from Japan, led by Associate Professor Masashi Kato from Nagoya Institute of Technology, to focus on improving one of the two existing non-destructive methods: time-resolved free-carrier absorption with intersectional lights (IL-TRFCA). In their new study published in Review of Scientific Instruments, the researchers present some impactful changes made to this technique (which they had previously pioneered) along with some very promising results.

The IL-TRFCA method essentially consists of excitation laser, which creates photoexcited carriers and a probe laser plus a detector, which measure their lifetime. By pointing both lasers at the edges of an objective lens (see Figure 1), they are made to converge at the surface of the sample with opposite incidence angles. Then, the sample is moved towards the lens in micrometric steps, which causes the excitation and probe lasers to intersect not at the surface of the sample, but at progressively deeper regions. In this way, the scientists managed to measure the distribution of carrier lifetimes within the sample without the need to cut it.

Two substantial changes the researchers made to the IL-TRFCA method were the adoption of a larger incidence angle of 34° (34 degrees) for both lasers and a higher numerical aperture in the objective lens and detector. These modifications resulted in enhanced depth resolution and also made it possible to use IL-TRFCA in thicker SiC layers. Excited about the results, Dr. Kato remarks, "Our non-destructive approach for measuring the distribution of carrier lifetimes allows one to determine the non-uniformity of a material without destroying the sample, which can then be used to fabricate devices, and research and develop bipolar SiC technology, such as high-voltage diodes and transistors."

Having appropriate measurements techniques at one's disposal is one of the most essential factors in materials research, and IL-TRFCA could easily pave the way for the study--and ultimately adoption--of SiC in ultrahigh-voltage applications. In this regard, Dr. Kato comments, "SiC devices can operate with lower power consumption compared with conventional semiconductors, and their commercialization could result in a substantial reduction in energy consumption in power systems throughout the world. In turn, this could alleviate serious environmental threats such as the accumulation of greenhouse gases."

Now that the tools have been laid out, it is time to delve deeper into how carrier lifetime distributions can be tuned in thick SiC and other semiconductors. Let us hope this leads us to more efficient devices and a more ecofriendly future!