Kamchatka’s Shiveluch volcano has had more than 40 violent eruptions over the last 10,000 years. The last gigantic blast occurred in 1964, creating a new crater and covering an area of nearly 100 square kilometers with pyroclastic flows. But Shiveluch is actually currently erupting, as it has been for over 20 years. So why would anyone risk venturing too close?

Researchers from Washington University in St. Louis, including Michael Krawczynski, assistant professor of earth and planetary sciences in Arts & Sciences and graduate student Andrea Goltz, brave the harsh conditions on Kamchatka because understanding what makes Shiveluch tick could help scientists understand the global water cycle and gain insights into the plumbing systems of other volcanoes.

In a recent study published in the journal Contributions to Mineralogy and Petrology, researchers from the Krawczynski lab looked at small nodules of primitive magma that were erupted and preserved amid other materials.

“The minerals in these nodules retain the signatures of what was happening early in the magma’s evolution, deep in Earth’s crust,” said Goltz, the lead author of the paper.

The researchers found that the conditions inside Shiveluch include roughly 10%-14% water by weight (wt%). Most volcanoes have less than 1% water. For subduction zone volcanoes, the average is usually 4%, rarely exceeding 8 wt%, which is considered superhydrous.

Of particular interest is a mineral called amphibole, which acts as a proxy or fingerprint for high water content at known temperature and pressure. The unique chemistry of the mineral tells researchers how much water is present deep underneath Shiveluch.

“When you convert the chemistry of these two minerals, amphibole and olivine, into temperatures and water contents as we do in this paper, the results are remarkable both in terms of how much water and how low a temperature we’re recording,” Krawczynski said.

“The only way to get primitive, pristine materials at low temperatures is to add lots and lots of water,” he said. “Adding water to rock has the same effect as adding salt to ice; you’re lowering the melting point. In this case, there is so much water that the temperature is reduced to a point where amphiboles can crystallize.”

Video: https://www.youtube.com/watch?v=ebVN7PcGJbo&feature=emb_logo

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Materials provided by Washington University in St. Louis. Original written by Shawn Ballard. Note: Content may be edited for style and length.

Now, a group of Brown University researchers has found a way to customize metallic grain structures from the bottom up. In a paper published in the journal Chem, the researchers show a method for smashing individual metal nanoclusters together to form solid macro-scale hunks of solid metal. Mechanical testing of the metals manufactured using the technique showed that they were up to four times harder than naturally occurring metal structures.

“Hammering and other hardening methods are all top-down ways of altering grain structure, and it’s very hard to control the grain size you end up with,” said Ou Chen, an assistant professor of chemistry at Brown and corresponding author of the new research. “What we’ve done is create nanoparticle building blocks that fuse together when you squeeze them. This way we can have uniform grain sizes that can be precisely tuned for enhanced properties.”

For this study, the researchers made centimeter-scale “coins” using nanoparticles of gold, silver, palladium and other metals. Items of this size could be useful for making high-performance coating materials, electrodes or thermoelectric generators (devices that convert heat fluxes into electricity). But the researchers think the process could easily be scaled up to make super-hard metal coatings or larger industrial components.

The key to the process, Chen says, is the chemical treatment given to the nanoparticle building blocks. Metal nanoparticles are typically covered with organic molecules called ligands, which generally prevent the formation of metal-metal bonds between particles. Chen and his team found a way to strip those ligands away chemically, allowing the clusters to fuse together with just a bit of pressure.

The metal coins made with the technique were substantially harder than standard metal, the research showed. The gold coins, for example, were two to four times harder than normal. Other properties like electrical conduction and light reflectance were virtually identical to standard metals, the researchers found.

The optical properties of the gold coins were fascinating, Chen says, as there was a dramatic color change when the nanoparticles were compressed into bulk metal.

“Because of what’s known as the plasmonic effect, gold nanoparticles are actually purplish-black in color,” Chen said. “But when we applied pressure, we see these purplish clusters suddenly turn to a bright gold color. That’s one of the ways we knew we had actually formed bulk gold.”

In theory, Chen says, the technique could be used to make any kind of metal. In fact, Chen and his team showed that they could make an exotic form of metal known as a metallic glass. Metallic glasses are amorphous, meaning they lack the regularly repeating crystalline structure of normal metals. That gives rise to remarkable properties. Metallic glasses are more easily molded than traditional metals, can be much stronger and more crack-resistant, and exhibit superconductivity at low temperatures.

“Making metallic glass from a single component is notoriously hard to do, so most metallic glasses are alloys,” Chen said. “But we were able to start with amorphous palladium nanoparticles and use our technique to make a palladium metallic glass.”

Chen says he’s hopeful that the technique could one day be widely used for commercial products. The chemical treatment used on the nanoclusters is fairly simple, and the pressures used to squeeze them together are well within the range of standard industrial equipment. Chen has patented the technique and hopes to continue studying it.

“We think there’s a lot of potential here, both for industry and for the scientific research community,” Chen said.

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The team, which includes Thomas Danz and Professor Claus Ropers, took advantage of an unusual property of a material made up of atomically thin layers of sulphur and tantalum atoms. At room temperature, its crystal structure is distorted into tiny wavelike structures — a “charge-density wave” is formed. At higher temperatures, a phase transition occurs in which the original microscopic waves suddenly disappear. The electrical conductivity also changes drastically, an interesting effect for nano-electronics.

In their experiments, the researchers induced this phase transition with short laser pulses and recorded a film of the charge-density wave reaction. “What we observe is the rapid formation and growth of tiny regions where the material was switched to the next phase,” explains first author Thomas Danz from Göttingen University. “The Ultrafast Transmission Electron Microscope developed in Göttingen offers the highest time resolution for such imaging in the world today.” The special feature of the experiment lies in a newly developed imaging technique, which is particularly sensitive to the specific changes observed in this phase transition. The Göttingen physicists use it to take images that are composed exclusively of electrons that have been scattered by the crystal’s waviness.

Their cutting-edge approach allows the researchers to gain fundamental insights into light-induced structural changes. “We are already in a position to transfer our imaging technique to other crystal structures,” says Professor Claus Ropers, leader of Nano-Optics and Ultrafast Dynamics at Göttingen University and Director at the MPI for Biophysical Chemistry. “In this way, we not only answer fundamental questions in solid-state physics, but also open up new perspectives for optically switchable materials in future, intelligent nano-electronics.”

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The research is important because “NSAIDs are arguably the most commonly used anti-inflammatory medications,” said principal investigator Craig B. Wilen, Assistant Professor of Laboratory Medicine and Immunology, Yale University School of Medicine.

In addition to taking NSAIDs for chronic conditions such as arthritis, people take them “for shorter periods of time during infections, and [during] acute inflammation as experienced with COVID-19, and for side effects from vaccination, such as soreness, fever, and malaise,” said Dr. Wilen. “Our work suggests that the NSAID meloxicam dampens the immune response to SARS-CoV-2 infection.”

The research also suggests that the consequences of NSAID use during natural infection and vaccination should be evaluated in humans, said Dr. Wilen. “This data likely exists, particularly in the clinical trials for the vaccines, so it should be mined to see if it produces antibody responses in people.”

“Taking NSAIDs during COVID-19 could be harmful or beneficial, depending on the timing of administration,” said Dr.Wilen. The potent anti-inflammatory, dexamethasone (not an NSAID), is detrimental to COVID-19 sufferers when taken early in the infection, but beneficial when administered during later stages of COVID-19, said Dr. Wilen.

Similarly, NSAIDs’ anti-inflammatory activity might be detrimental early in SARS-CoV-2 infection, because at this stage, inflammation is usually helpful. That changes at later stages of COVID-19, particularly if the patient undergoes an intense inflammation known as a cytokine storm. A cytokine storm is an immune response of inflammatory compounds that often occurs in COVID-19 patients, can lead to complications, need for the intensive care unit, and even death.

A reduction in neutralizing antibodies caused by NSAIDs might be benign, or it might blunt the immune system’s ability to fight the disease during the early stages of infection. It could also reduce the magnitude and/or length of protection from either natural infection or vaccination, said Dr. Wilen.

The initial motivation to investigate NSAIDs’ effect on COVID-19 “was a twitter thread, suggesting NSAIDs should not be used during COVID-19,” said Dr. Wilen. “This seemed suspicious to us, so we wanted to investigate.”

Dr. Wilen and his team expected that there would be little to no effect of NSAIDs on viral infection, which turned out to be correct.They also thought that NSAIDs would not significantly affect the antibody response to natural infection. “In fact, we initially didn’t even carefully look at the antibody response, because we didn’t expect it to be altered by NSAIDs. This turned out to be wrong, said Dr. Wilen.

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A new Flinders University study of 1040 online participants from five western countries published in PLOS ONE explores people’s response to the stresses of the escalating pandemic, finding more than 13% of the sample had post-traumatic stress disorder (PTSD) related symptoms consistent with levels necessary to qualify for a clinical diagnosis.

With ongoing economic and social fallout, and death toll of more than 2 million, the team of psychology researchers warn more needs to be done to cope with the potential short and long-term spike in PTSD cases resulting from the pandemic — as well as related mental health problems such as anxiety, depression, psychosocial functioning, etc.

“While the global pandemic does not fit into prevailing PTSD models, or diagnostic criteria, our research shows this ongoing global stressor can trigger traumatic stress symptoms,” says lead researcher Associate Professor Melanie Takarangi, from Flinders Psychology.

“We found that traumatic stress was related to future events, such as worry about oneself or a family member contracting COVID-19, to direct contact with the virus, as well as indirect contact such as via the news and government lockdown — a non-life threatening event,” says co-author Victoria Bridgland, who is undertaking a PhD studying the triggers of PTSD.

PTSD is a set of reactions, including intrusive recollections such as flashbacks, that can develop in people exposed to an event that threatened their life or safety (e.g., sexual assault, natural disaster).

“Our findings highlight the need to focus on the acute psychological distress — including the perceived emotional impact of particular events — associated with COVID-19 and build on other research from the past year that demonstrates the damaging psychological impact of COVID-19 on mental health,” says Ms Bridgland.

Comprehensive long-term documentation of COVID-19 related traumatic stress reactions will allow health professionals to help people who could otherwise fall through the cracks, the research team concludes.

The online survey examined a range of responses to common post-traumatic stress symptoms, such as repeated disturbing and unwanted images, memories or thoughts about the COVIC-19 pandemic.

COVID-19’s psychological fallout has been dubbed the “second curve,” predicted to last for months to years, the paper notes.

“Notably, while most of our participants reported experiencing some form of psychological distress and 13.2% of our sample were likely PTSD positive when anchoring symptoms to COVID-19, only 2% of our total sample reported they had personally tested positive to COVID-19, and only 5% reported that close family and friends had tested positive.

“It therefore seems likely that the psychological fallout from COVID-19 may reach further than the medical fallout,” the paper concludes.

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Most plastics resist natural degradation processes. Consequently, increasing contamination of the environment with plastics has led to a call for degradable plastics. Such materials can be subjected to chemical recycling processes, in which chemical reactions break up polymer bonds. Industry then either recovers the monomers and re-subjects them to polymerization, or it collects the resulting small molecules as useful building blocks for further reactions.

However, degradable polymers require a more elaborate polymer design. The linkages between the polymer building blocks should be sensitive to chemical or enzymatic treatments. In addition, sustainable polymers should be made of bio-based feedstock.

Tae-Lim Choi and colleagues from Seoul National University, South Korea, have found a way to produce high-quality polymers from xylose-based monomers. Xylose is a sugar found in plant cell walls. The method they use involves the preparation of the xylose-based monomers, including the attachment of linker groups, and reacting the monomers in a polymerization process called cascade metathesis polymerization.

To test if such plastic materials are degradable, the researchers treated the xylose-based polymers with hydrochloric acid, a treatment commonly found in chemical recycling procedures. The researchers found that the degradability depended on the linkage type. If the polymer contained a linkage made of a carbon atom, the polymer resisted hydrolysis, but linkages made with nitrogen or oxygen atoms led to immediate degradation.

Polymers with a nitrogen-based linkage resulted in compounds called pyrroles, whereas those made with oxygen produced furans. Pyrroles and furans are both abundant, naturally occurring compounds. However, the researchers advise care: “Furan derivatives are known to have a broad range of biological activity, which should be taken into consideration when identifying applications for these polymeric materials,” they said.

In block copolymers, different “blocks” of shorter polymer strands are attached to each other. Accordingly, block copolymers have properties arising from those of the single blocks. As many functional materials can be made with block copolymers, the authors tested whether xylose-based block copolymers containing blocks with non-degradable linkages would also disintegrate by acid treatment. They did. “After 24 h, also the carbon-linkage-containing block was almost completely degraded to small molecules, with only a little oligomeric material remaining,” the authors reported.

The researchers also integrated small reporter molecules in the polymers. Acid hydrolysis of the polymers with oxygen linkages produced furan derivatives, which subsequently released para-nitrophenol as a reporter molecule. “This type of cargo enables easy quantification of release. However, it can be substituted with other compounds, which exert various functions after their release,” Choi says.

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