Tech

Transportation - Gauging pandemic impact

Oak Ridge National Laboratory researchers have developed a machine learning model that could help predict the impact pandemics such as COVID-19 have on fuel demand in the United States.

Called the Pandemic Oil Demand Analysis, or PODA, this model compared mobility patterns before and during the COVID-19 pandemic, analyzing historical weekly motor travel trends and projecting future usage.

"We developed this machine learning-based model by studying trip activities and corresponding fuel usage," ORNL's Shiqi (Shawn) Ou said. "The PODA analysis can serve as a useful tool to understand the impact of travel quarantine on fuel demand."

In a Nature Energy study sponsored by Aramco Research Center, researchers focusing on mid-May until August determined that average fuel demand is not likely to reach pre-pandemic levels before October 2020. However, while a continued quarantine would have a negative impact on fuel demand temporarily, demand would likely recover to normal levels quicker.

PODA data could help inform economic and energy planning.

Media contact: Jennifer Burke, 865.414.6835, burkejj@ornl.gov

Image: https://www.ornl.gov/sites/default/files/2020-08/Transportation-Gauging_pandemic_impact_ORNL.jpg

Caption: ORNL researchers developed a machine learning model to know the impact a pandemic can have on U.S. fuel demand prior to a travel quarantine. Credit: Andy Sproles/ORNL, U.S. Dept. of Energy

Ecosystem - At the root

Oak Ridge National Laboratory scientists evaluating northern peatland responses to environmental change recorded extraordinary fine-root growth with increasing temperatures, indicating that this previously hidden belowground mechanism may play an important role in how carbon-rich peatlands respond to warming.

The team working at DOE's whole-ecosystem warming experiment in northern Minnesota found that shrub fine-root growth increased linearly by 130% for every degree increase in soil temperature - a response 20 times greater than other ecosystems. This was driven by soil drying in the usually sodden peatlands, which store one-third of the world's soil carbon.

According to published results, this response could explain why shrub coverage is increasing in these landscapes, which could shade out Sphagnum moss - a key species for carbon fixation in peatlands - and have downstream effects on peatland carbon storage.

"This work helps us understand a previously unknown aspect of these ecosystems, the world belowground," said Avni Malhotra of Stanford University, formerly of ORNL.

Media contact: Stephanie Seay, 865.604.3384, seaysg@ornl.gov

Link: https://www.ornl.gov/sites/default/files/2020-08/FineRootGrowth.jpg

Caption: A belowground snapshot reveals the complex maze of tree and shrub roots and their fungal partners in carbon-rich peatland soils. Credit: Colleen Iversen/ORNL, U.S. Dept. of Energy

Link: https://www.ornl.gov/sites/default/files/2020-08/SPRUCE.png

Caption: Scientists use the Spruce and Peatland Responses Under Changing Environments experiment in Minnesota to assess the response of northern peatlands to increases in temperature and atmospheric carbon dioxide. Credit: ORNL, U.S. Dept. of Energy

Neutrons - Ferromagnetic topological material

A UCLA-led team that discovered the first intrinsic ferromagnetic topological insulator - a quantum material that could revolutionize next-generation electronics - used neutrons at Oak Ridge National Laboratory to help verify their finding.

Topological insulators act as insulators on the inside while allowing electrons to flow across their surfaces. Their less-studied ferromagnetic counterparts are thought to hold useful properties for quantum technology. The researchers discovered the first intrinsic ferromagnetic topological insulator - consisting of manganese, bismuth and tellurium atoms - by stacking ferromagnetic molecular layers.

To confirm the material's intrinsic nature, the team used the High Flux Isotope Reactor at ORNL.

"Neutron diffraction's high contrast can distinguish magnetic manganese atoms from others," said ORNL's Huibo Cao, co-author on the study published in Science Advances. "It is well-suited for the new two-dimensional material and its magnetism."

"Using neutron diffraction, we concluded the atomic arrangement in each layer and confirmed the ferromagnetic order to support this discovery," added ORNL co-author Lei Ding.

Media contact: Abby Bower, 865.323.9943, bowerae@ornl.gov

Image: https://www.ornl.gov/sites/default/files/2020-08/2017-S00412.jpg

Caption: Researchers performed single-crystal neutron diffraction using the HB-3A four circle diffractometer to confirm the first intrinsic ferromagnetic topological insulator. Credit: Genevieve Martin/ORNL, U.S. Dept. of Energy

Technology - Lab on a crystal

An all-in-one experimental platform developed at Oak Ridge National Laboratory's Center for Nanophase Materials Sciences accelerates research on promising materials for future technologies.

The "Lab-on-a-crystal," designed on a commercially available quartz crystal microbalance, or QCM, measures materials' interrelated responses to the environment in real time - something that traditionally required different specialized instruments, multiple experiments and a lot of time.

Modified QCM hardware has been incorporated into a machine learning platform that optimizes data collection and identifies correlations among several simultaneous measurements, including mechanical, electrical and optical.

"Being able to characterize multiple functionalities simultaneously at macro-, micro- and nanoscales on the same sample is a breakthrough for materials sciences. In a day, we can accomplish a month's worth of experiments," said ORNL's Ilia Ivanov.

A collaboration with researchers from the European Union on advancing rapid-detection methods for enzymes that degrade milk quality highlights the platform's broad applications to CNMS users. -- Ashley Huff

Media contact: Sara Shoemaker, 865.576.9219, shoemakerms@ornl.gov

Image: https://www.ornl.gov/sites/default/files/2020-08/lab_on_crystal2.png

Caption: ORNL's Lab-on-a-crystal uses machine learning to correlate materials' mechanical, optical and electrical responses to dynamic environments. Credit: Ilia Ivanov/ORNL, U.S. Dept. of Energy

Computing - Enhancing fusion models

Combining expertise in physics, applied math and computing, Oak Ridge National Laboratory scientists are expanding the possibilities for simulating electromagnetic fields that underpin phenomena in materials design and telecommunications.

An initial application for the work is in fusion energy, for which modeling small-scale, energetic particle movements in fusion plasmas requires complex numerical simulations, particularly at plasma boundaries where electromagnetic fluctuations can result in energy loss or damage to the fusion reactor.

To overcome computational limitations and advance models of whole fusion reactors, the ORNL team developed the Adaptive Sparse Grid Discretization, or ASGarD, mathematical framework for solving complex equations.

As reported in a recent Computer Physics Communications paper, the team applied its framework to the foundational equations of electromagnetism, known as Maxwell's equations, and demonstrated a 100-times reduction in the computational resources required for solving the equations compared to traditional methods. -- Katie Jones

Media contacts: Jason Ellis, 865.241.5819, ellisjk@ornl.gov; or Scott Jones, 865.241.6491 jonesg@ornl.gov

Image: https://www.ornl.gov/sites/default/files/2020-08/Max1_t5e-1_EB.png

Caption: Using the ASGarD mathematical framework, scientists can model and visualize the electric fields, shown as arrows, circling around magnetic fields that are colorized to represent field magnitude of a fusion plasma. Credit: David Green/ORNL, U.S. Dept. of Energy

Resistance to artemisinin, the main component of the current antimalarial treatments recommended by WHO, is already widespread in South-East Asia, but it had not previously been described in Africa. Scientists from the Institut Pasteur, in collaboration with the National Malaria Control Program in Rwanda (Rwanda Biomedical Center), the World Health Organization (WHO), Cochin Hospital and Columbia University (New York, USA), recently detected the emergence and spread of malaria parasites capable of resisting artemisinin derivatives for the first time in Rwanda. The results of the research were published on August 3, 2020 in Nature Medicine.

Malaria, caused by parasites of the genus Plasmodium, represents a major public health problem. Almost 3.2 billion people (virtually half the world's population) in 89 countries are at risk of contracting the disease, for which there is currently no vaccine. Every year, over 200 million cases and over 400,000 deaths are recorded.

For more than 15 years, treatment of malaria episodes (typical cycles of the disease alternating between fever, shivering and chills, and severe sweating) caused by Plasmodium falciparum has depended on artemisinin-based combination therapies (ACTs), which combine a fast-acting artemisinin derivative and a partner drug with a long half-life. Since 2008, parasites capable of resisting artemisinin derivatives in South-East Asia (Cambodia, Thailand, Vietnam, Myanmar and Laos) have become increasingly prevalent. This resistance, which leads to a delay in the clearance of parasites from the bloodstream of individuals treated with an ACT, is currently a serious threat that may hinder efforts to tackle the disease. A major concern is that these resistant parasites will spread through Sub-Saharan Africa, the continent most affected by malaria (>90% of cases), as was the case with previous generations of antimalarial treatments (chloroquine and folic acid antagonists). In the 1980s, the reduced efficacy of chloroquine is thought to have contributed to several million additional deaths from malaria in young African children.

Since 2014, the geographical distribution of artemisinin resistance has been monitored based on the detection of mutations in the Kelch13 gene in parasites. These mutations are believed to reduce the function of the Kelch13 protein, thought to be involved in hemoglobin degradation in infected red blood cells. Currently, the most widespread resistant parasites in South-East Asia have the C580Y mutation. Recently, C580Y mutant parasites have also been detected in Guyana and Papua New Guinea. In Africa, where ACTs remain very effective, Kelch13 mutant parasites have remained rare. For instance, the KARMA study, the first global map of artemisinin resistance, showed that less than 5% of African samples had mutations and that more than 50% of the mutants detected had only been observed once. Scientists also demonstrated that the most frequently observed mutation in Africa (A578S) did not confer artemisinin resistance to gene-edited Asian parasites.

Scientists from the Institut Pasteur, involved in a WHO-supported project on molecular monitoring of resistance in Africa, recently identified the first signs of emergence of artemisinin-resistant Kelch13 mutant parasites in Africa. The results describe significant proportions of parasites carrying the R561H mutation in two locations 100km apart (prevalences of 7.4% in Masaka and 0.7% in Rukara, respectively). Whole-genome sequencing of these parasites indicates that the R561H mutants were selected from Rwandan parasite populations and that they had not spread from Asian parasites (from Thailand or Myanmar, where the R561H mutation has previously been observed). "These unexpected results contrast with previous scenarios in which the emergence of chloroquine- or pyrimethamine-resistant parasites in Africa was caused by the spread of resistant parasites from South-East Asia. It was thought that a similar scenario would apply for the emergence of artemisinin-resistant parasites in Africa," explains Didier Ménard, Head of the Malaria Genetics and Resistance Unit at the Institut Pasteur. The fact that this resistant strain has spread between several places in Rwanda and its ability to resist artemisinin in vitro have major public health implications. In the absence of effective measures to contain the spread of resistant parasites in Rwanda and neighboring countries, there is a risk that over time they will acquire the ability to resist the partner drugs used in ACTs. This would mean that the only available treatments would become ineffective, as has occurred in South-East Asia. A model of this scenario, in which no measures are taken, recently predicted that the inefficacy of ACTs in Africa could be responsible for 78 million additional cases and 116,000 additional deaths over a five-year period.

Ankylosing spondylitis (AS) is a complex chronic inflammatory disease of the spine with involvement of the sacroiliac joints. Over the course of the disease, the joints and adjacent tissues ossify, which results in a partial or complete stiffening of the spine. Many patients complain of pain in the spine, lower back, buttocks and hips, which can be particularly severe in the morning. Pain in the second half of the night often wakes up AS patients and they need to do some exercise to relieve it. The disease most commonly presents in the twenties and thirties. "Female patients with AS are therefore mostly of childbearing age and are sometimes uncertain as to whether they can make their desire to have children a reality, despite their chronic disease," said EULAR President Professor Iain B. McInnes, Director of the Institute of Infection, Immunity and Inflammation at the University of Glasgow in Scotland.

A South Korean population-based case study investigated the question of whether AS in women could have an effect on the growth and development of their children in early childhood and what effect that might be. The team led by Sung Hae Chang from Soonchunhyang University College of Medicine Cheonan Hospital, Chungbuk National University Hospital and Korea University College of Medicine used two South Korean databases managed by the National Health Insurance Service (NHIS): the National Health Screening Program for Infants and Children (NHSIC) database, which records screening data of the growth and development of all children; and the NHIS database, which covers the entire population and includes comprehensive health claims data. The researchers enrolled all children born between 2008 and 2013, who were examined three times. The first examination took place at the age of four to six months, the second at nine to twelve months, and the third at either 54 to 65 months or 66 to 71 months.

"We analysed data on 794,544 children in total," explained the lead author of the study, Sung Hae Chang from the Soonchunhyang University College of Medicine Cheonan Hospital. Among them were 369 children of mothers with AS. Of these, 124 women had already been diagnosed with AS before delivery, while in 245 the disease was only detected post-partum.

This showed that the growth and development of children of mothers with AS were comparable to those of offspring of other women. And while mothers with an existing AS diagnosis were significantly more likely to have an infant with a low birth weight than women diagnosed with AS post-partum, their offspring developed similarly overall over the observation period of up to 71 months after birth. "Therefore, having a chronic disease like AS should not hinder female patients from having healthy children," said Professor John Isaacs, Newcastle University, UK, Chair of the EULAR Scientific Programme Committee. "We advise women with AS who want to have children to plan their pregnancy and to discuss it beforehand with their treating rheumatologist."

Climate change has increased the productivity of forests, according to a new study that synthesizes hundreds of thousands of carbon observations collected over the last quarter century at the Harvard Forest Long-Term Ecological Research site, one of the most intensively studied forests in the world.

The study, published today in Ecological Monographs, reveals that the rate at which carbon is captured from the atmosphere at Harvard Forest nearly doubled between 1992 and 2015. The scientists attribute much of the increase in storage capacity to the growth of 100-year-old oak trees, still vigorously rebounding from colonial-era land clearing, intensive timber harvest, and the 1938 Hurricane - and bolstered more recently by increasing temperatures and a longer growing season due to climate change. Trees have also been growing faster due to regional increases in precipitation and atmospheric carbon dioxide, while decreases in atmospheric pollutants such as ozone, sulfur, and nitrogen have reduced forest stress.

"It is remarkable that changes in climate and atmospheric chemistry within our own lifetimes have accelerated the rate at which forest are capturing carbon dioxide from the atmosphere," says Adrien Finzi, Professor of Biology at Boston University and a co-lead author of the study.

The volume of data brought together for the analysis - by two dozen scientists from 11 institutions - is unprecedented, as is the consistency of the results. Carbon measurements taken in air, soil, water, and trees are notoriously difficult to reconcile, in part because of the different timescales on which the processes operate. But when viewed together, a nearly complete carbon budget - one of the holy grails of ecology - emerges, documenting the flow of carbon through the forest in a complex, multi-decadal circuit.

"Our data show that the growth of trees is the engine that drives carbon storage in this forest ecosystem," says Audrey Barker Plotkin, Senior Ecologist at Harvard Forest and a co-lead author of the study. "Soils contain a lot of the forest's carbon - about half of the total - but that storage hasn't changed much in the past quarter-century."

The trees show no signs of slowing their growth, even as they come into their second century of life. But the scientists note that what we see today may not be the forest's future. "It's entirely possible that other forest development processes like tree age may dampen or reverse the pattern we've observed," says Finzi.

The study revealed other seeds of vulnerability resulting from climate change and human activity, such as the spread of invasive insects.

At Harvard Forest, hemlock-dominated forests were accumulating carbon at similar rates to hardwood forests until the arrival of the hemlock woolly adelgid, an invasive insect, in the early 2000s. In 2014, as more trees began to die, the hemlock forest switched from a carbon "sink," which stores carbon, to a carbon "source," which releases more carbon dioxide to the atmosphere than it captures.

The research team also points to extreme storms, suburbanization, and the recent relaxation of federal air and water quality standards as pressures that could reverse the gains forests have made.

"Witnessing in real time the rapid decline of our beloved hemlock forest makes the threat of future losses very real," says Barker Plotkin. "It's important to recognize the vital service forests are providing now, and to safeguard those into the future."

Real-time measurements captured by researchers at the Department of Energy's Oak Ridge National Laboratory provide missing insight into chemical separations to recover cobalt, a critical raw material used to make batteries and magnets for modern technologies.

Results published in ACS Applied Materials and Interfaces, track the dynamics of molecules designed to grab cobalt from solutions containing a mixture of similar species.

"Understanding the molecular events that make it possible to separate elements is key to optimizing or creating new, tailored approaches for broad areas of materials recovery," said Ben Doughty of ORNL's Chemical Sciences Division.

The study investigates the fundamental chemistry underlying solvent extraction, a method of separating elements using two liquids that do not dissolve into one another, namely oil and water.

When agitated, oil-and-water solutions will self-separate into distinct layers. The phenomenon can be used to transfer targeted materials dissolved in one liquid phase to another, allowing specific elements like cobalt to be separated from everything else in the mix.

"The catch is that you need to have molecules at the interface between these liquid layers that are poised to bind selectively with the materials you want to extract," said Doughty. "But the complex chemistry happening at the surface has not been well understood."

Insight into the chemical reactions that enable cobalt and other separations has eluded researchers for decades, owing to the challenges of probing the liquid-liquid interface where oil and water meet. The molecularly thin surface is akin to a needle in a haystack, tending to be obscured by the bulk solution when traditional spectroscopic methods are used. Adding to the difficulty are competing time scales of activity, ranging from femtoseconds -- one quadrillionth of a second -- to minutes, that conventional static measurements do not capture.

"This interface is essentially the gatekeeper between oil and water layers, where chemical bonds that facilitate extractions are made or broken. To fine-tune the separation process, you need to understand what is happening at this interface in real time," Doughty said.

ORNL is one of a few groups specializing in techniques to probe a functioning liquid-liquid interface.

Building from previous work on polymers, the team looked at the ligand di-(2-ethylhexyl) phosphoric acid, or DEHPA, an industry-standard extractant that selectively binds with cobalt ions over similar metals such as nickel that often naturally accompany cobalt in solution.

DEHPA dissolved in oil was introduced to water-based solutions with and without cobalt and probed using vibrational sum frequency generation, an ultrafast pulsed laser technique that allowed researchers to home in on reactions taking place at the liquid-liquid interface.

What sets this technique apart from other experimental methods is the capability to track kinetics at the interface, or the changes taking place at the surface during a chemical reaction.

"Solvent extraction is designed to work within specific conditions for a given target, and pH is a commonly adjusted variable. So, our experiment was set up to observe the influence of pH ranges on DEHPA and understand what gives rise to the sweet spot for cobalt extraction," Doughty said.

The oil-based ligand interacts with water to form aggregates, or groups of molecules that play an important role in extractions. Their job is to bind and transport cobalt, but they need to be the right size and structure to work effectively. The team discovered that hydrogen bonds influence the arrangement of these aggregates and are sensitive to pH changes.

"Our findings highlight the essential role hydrogen bonding plays in developing new extraction methodologies," said Doughty. "Moreover, we observed that the pH of the bulk solution impacts hydrogen bonding and could potentially be adjusted to tune the liquid-liquid interface for peak performance."

Understanding the design rules for extraction opens avenues for reducing the energy and environmental costs of processing cobalt and, in turn, securing ethically sourced supply chains.

Cobalt recovery is just one example of how fundamental insight into chemical separations could be beneficial. Informed strategies could be applied to broad areas of critical materials recovery and nuclear waste cleanup where solvent extraction methods are widely employed.

Scientists at Tokyo Institute of Technology and Socionext Inc. have developed a novel transceiver for enabling seamless communication between earth ground platforms and satellites in the low, middle, and geostationary earth orbits. Among other things, this transceiver could bring Internet to people in remote rural areas and at sea.

We live in the information age, where communications technologies have reached unprecedented levels of advancement. Yet, bringing connectivity to remote locations, such as rural areas or the open sea, remains difficult. Satellite communication (SATCOM) is an attractive option for providing data links to such places; but for effective SATCOM, the right equipment must exist both in space and here on Earth.

At the forefront of research to achieve superior SATCOM are scientists from Prof Kenichi Okada's lab at Tokyo Institute of Technology (Tokyo Tech), who have developed a novel transceiver[1] for SATCOM using standard CMOS[2] technology. This transceiver operates in the "Ka band," which, for SATCOM, means a 27-31 GHz frequency range for uplink (ground to satellite) and 17-21 GHz range for downlink (satellite to ground).

Their design carries a variety of features that make it stand out from the competition. On the transmitter (TX) side, a high-quality-factor transformer is employed to achieve efficient power use and high linearity in transmission, which results in lower distortion during transmission. The receiver (RX) side features a dual-channel architecture that unlocks several capabilities.

First, having two RX channels allows for receiving signals from two satellites simultaneously. These signals are received in parallel using either two independent polarization modes or two different frequencies. In addition, the proposed design can perform adjacent-channel interference cancellation; that is, the "contamination" on a signal received in one channel by another signal on an adjacent frequency band is eliminated using information received at the other channel. This strategy increases the dynamic range of the system, thus allowing it to operate correctly even in less-than-ideal scenarios with stronger noise and interference.

Both the TX and RX perform direct conversion of a signal; that is, the TX directly converts a baseband signal[3] into a modulated signal[4] and the RX performs the inverse process without additional intermediate frequency conversions, unlike the more commonly used superheterodyne receivers. This makes the overall complexity, size, and power consumption of the transceiver considerably lower.

The scientists created a prototype chip to test the actual performance of their design when using all the modulation schemes regulated by the SATCOM DVB-S2X standard. This includes high-order modulation techniques like 64 APSK[5] and 256 APSK, which provide fast data rates.

The performance test results are very promising, especially when compared with other existing SATCOM transceivers, putting this developed novel design on the map. Prof Okada remarks, "Our paper presents the first Ka-band SATCOM transceiver implemented using standard CMOS technology and designed for an earth ground platform communication with geostationary and low Earth orbit satellites."

These orbits are at 35,786 km and 200-2,000 km, respectively. Communicating with satellites that far away from a 3 mm by 3 mm chip is certainly no simple feat.

For years, Prof Okada's lab has been developing various types of state-of-the-art transceivers for next-generation technology, including 5G applications, Internet-of-Things-enabled devices, and low-power Bluetooth communications. This latest transceiver is another piece in the puzzle of enabling seamless worldwide connectedness. "Satellite communication has become a key technology for providing interactive TV and broadband internet services in low-density rural areas. Implementing Ka-band communications using silicon--CMOS technology in particular--is a promising solution owing to the potential for global coverage at low cost and using the wide available bandwidth," Prof Okada says.

Let us hope that the efforts of these Tokyo Tech researchers help more people benefit from instant communication in the current information era.

As the COVID-19 pandemic continues to spread, scientists and health care providers are seeking ways to keep the coronavirus from infecting tissues once they're exposed. A new study suggests luring the virus with a decoy - an engineered, free-floating receptor protein - binds the virus and blocks infection.

Erik Procko, a professor of biochemistry at the University of Illinois, Urbana-Champaign, led the study, published in the journal Science.

To infect a human cell, a virus must first bind to a receptor protein on the surface of the cell. SARS-CoV-2, the coronavirus that causes COVID-19, binds to a receptor called ACE2, which plays a number of roles in regulating blood pressure, blood volume, and inflammation. It is found in tissues throughout the body, but especially in the lungs, heart, arteries, kidneys and intestines. Many researchers hypothesize that the host of symptoms associated with COVID-19 may stem from the coronavirus binding to ACE2 and keeping it from doing its job.

"Administering a decoy based on ACE2 might not only neutralize infection, but may have the additional benefit of rescuing lost ACE2 activity and directly treating aspects of COVID-19," Procko said.

As a potential therapeutic agent, a decoy receptor has one advantage over other drugs: To evade it, the virus would have to mutate in a way that would make it less infectious.

"A benefit of a decoy receptor is that it closely resembles the natural receptor. Therefore, the virus cannot easily adapt to escape neutralization without simultaneously losing its ability to bind to its natural receptor. This means the virus has limited ability to acquire resistance," Procko said.

Although ACE2 binds to SARS-CoV-2, it is not optimized for that purpose, which means that subtle mutations to the receptor could make it bind more strongly. This makes it an ideal candidate for a decoy receptor, Procko said.

Procko examined more than 2,000 ACE2 mutations and created cells with the mutant receptors on their surfaces. By analyzing how these interacted with the coronavirus, he found a combination of three mutations that made a receptor that bound to the virus 50 times more strongly, making it a much more attractive target for the virus.

Procko then made a soluble version of the engineered receptor. Detached from cells, the soluble receptor is suspended in solution and free to interact with the virus as a decoy receptor.

After Procko posted his findings to a preprint server, a colleague connected him with the U.S. Army Medical Research Institute of Infectious Diseases. Researchers there, along with the lab of Illinois biochemistry professor David Kranz, verified the strong affinity between the virus and the decoy receptor, rivaling the best antibodies identified to date, Procko said. Furthermore, they found that the decoy receptor not only binds to the virus in live tissue cultures, it effectively neutralizes it, preventing cells from becoming infected.

Further work is required to determine whether the decoy receptors could be an effective treatment of or preventive agent against COVID-19.

"We are testing whether the decoy receptor is safe and stable in mice, and if successful, we then hope to show treatment of disease in animals. Hopefully that data can facilitate a clinical trial," Procko said. He also is exploring how the decoy receptor bonds to other coronaviruses with potential to become future pandemics if they cross from bats to humans.

By exploring variants of a soluble version of the receptor that SARS-CoV-2 uses to binds human cells - which are being considered as therapeutic candidates that neutralize COVID-19 infection by acting as a decoy - researchers identified one that binds the virus's spike protein tightly enough to compete with spike binding by monoclonal antibodies. Its similarity to the natural receptor on human cells may limit the possibility for the virus to "escape" it, as it would when under pressure from antibodies. The SARS-CoV-2 virus enters human cells when the spike protein binds to the host ACE2 receptor. While neutralizing antibodies to the spike protein have been isolated, the spike can develop "escape mutations" that help it evade them. Compared to antibodies, the virus may be less likely to escape neutralization by a decoy ACE2 without simultaneously decreasing affinity for this receptor. Thus, a soluble version of ACE2 is now being explored as a therapeutic. Hypothesizing that mutations in ACE2 may increase its binding affinity to SARS-CoV-2, Kui Chan and colleagues sought out such mutations using deep mutagenesis. They diversified a full-length sequence of ACE2 to create a library containing all possible single amino acid substitutions that spanned the interface between the spike protein and its binding cavity. Following expression of these variants in human cells, Chan and colleagues report one promising soluble variant, dubbed sACE2.v2.4, with a binding affinity comparable to that of neutralizing antibodies. It neutralized both SARS-CoV-2 and SARS-CoV-1 in a cell-based assay, they say, making it a powerful potential virus decoy. "It is possible that the decoy receptor will neutralize diverse ACE2-utilizing coronaviruses that have yet to cross over to humans," they note.

Oliver Hofmann and his research group at the Institute of Solid State Physics at TU Graz are working on the optimization of modern electronics. A key role in their research is played by interface properties of hybrid materials consisting of organic and inorganic components, which are used, for example, in OLED displays or organic solar cells. The team simulates these interface properties with machine-learning-based methods. The results are used in the development of new materials to improve the efficiency of electronic components.

Long-range charge transfer as a subject of investigation

The researchers have now taken up the phenomenon of long-range charge transfer. A transfer of electrons from one material to another already occurs in the switched-off state if there are energetically more favourable states for the electrons in the neighbouring material. This raises the fundamental question of how far this transfer of electrons can extend in organic material, i.e. how many layers it encompasses. Many studies report that for organic-inorganic interfaces this effect is limited to the first layer, i.e. the layer where the (organic) molecules are in direct contact with the (inorganic) metal surface.

On the other hand, some reports assume that the effect also extends over longer distances, to the second layer or beyond. "If this is the case, the effect could be used to reduce the electrical resistance of the hybrid material, making it more energy efficient," says Hofmann, explaining why it is so interesting.

New examination method combines two machine learning methods

In order to demonstrate long-range charge transport in organic-inorganic interfaces, the researchers used the new machine learning methods SAMPLE and BOSS to investigate a copper-tetracyanoethylene interface (TCNE/Cu(111)), "since there are particularly strong experimental data available here that indicate long-range charge transport," said Hofmann. There is no clear theory why some systems show this effect. Hofmann and his team wanted to "solve this mystery in order to create a basis for how to produce materials with the same property."

By combining both methods, the researchers were able to identify over two million potential interface structures for the TCNE-Cu interfaces and predict the behaviour of the molecules under various experimental conditions. Surprisingly, the results showed that there is no long-range charge transfer, but instead the molecules in the system change their structure.

Molecules change their atomic arrangement

When molecules are applied, usually they retain their general arrangement and pack more closely until, at a certain density, they finally start growing the second layer. In the TCNE/Cu(111) system, however, the adsorbed molecules change from the original lying position to a standing one after a certain amount has been deposited. They thus straighten up in order to be able to crowd even closer together. "However, standing molecules have a completely different charge transfer than lying molecules. The structural transformation is difficult to detect experimentally, but the measurement results are similar to those of long-range charge transport," explains Hofmann.

The investigations refute the hypothesis of long-range charge transfer. The use of the combined machine learning methods SAMPLE and BOSS is intended to support future experiments in material development in such a way that such misinterpretations no longer occur. By taking a deeper look into the physical processes, the new processes help to ensure that materials are no longer designed to chase an effect that does not exist in this form. Hofmann underlines the advantage of the new method: "Thanks to the two methods, millions of different structures can be simulated in the future." The TU Graz researchers recently published details of the study in Advanced Science.

C1 polymerization is a useful technique for preparing polymers with a carbon-carbon main chain. This technique constructs a polymer backbone from "one carbon unit", in contrast to conventional vinyl polymerization, which produces polymers from a "two carbon unit" derived from vinyl groups. The representative characteristic of C1 polymerization is that it can yield carbon-carbon main polymers having a substituent on each main chain carbon atom [poly(substituted methylene)s]. For the C1 polymerization system, diazoacetates are suitable monomers, yielding polymers with an alkoxycarbonyl group (ester) on each main chain carbon atom.

Stimuli-responsive polymers or smart polymers are macromolecules that undergo a change in properties in response to external stimuli, such as temperature, pH, light, and additives. Their stimuli-responsive behavior strongly depends on the primary structure of the polymer, and thus precise synthesis is necessary to develop smart materials with superior properties. Precise C1 polymerization for diazoacetates is still a challenge, whereas various controlled/living polymerization techniques of vinyl monomers have been achieved to give well-defined stimuli-responsive vinyl polymers. In this context, with the results reported in this report, we have demonstrated that diazoacetates with a sterically bulky substituent can be polymerized in a controlled manner with the π-allylPdCl/borate systems to yield polymers with narrow molecular weight distribution. In addition, we have successfully synthesized carboxy-functionalized dendronized polymers and demonstrated the characteristic pH-responsive behavior derived from the dense accumulation of the side chains in comparison to the corresponding vinyl polymers bearing the same side chains. The introduction of functional groups, other than a carboxy group, in the peripheral phenyl groups should result in a high density of the functional groups around the rigid main chain. These structural characteristics will lead to development of a variety of new functional poly(substituted methylene)s in the near future.

The RCP 8.5 C02 emissions pathway, long considered a "worst case scenario" by the international science community, is the most appropriate for conducting assessments of climate change impacts by 2050, according to a new article published today in the Proceedings of the National Academy of Sciences. The work was authored by Woods Hole Research Center (WHRC) Risk Program Director Dr. Christopher Schwalm, Dr. Spencer Glendon, a Senior Fellow at WHRC and founder of Probable Futures, and by WHRC President Dr. Philip Duffy. Long dismissed as alarmist or misleading, the paper argues that is actually the closest approximation of both historical emissions and anticipated outcomes of current global climate policies, tracking within 1% of actual emissions.

"Not only are the emissions consistent with RCP 8.5 in close agreement with historical total cumulative CO2 emissions (within 1%), but RCP8.5 is also the best match out to mid-century under current and stated policies with still highly plausible levels of CO2 emissions in 2100," the authors wrote. "...Not using RCP8.5 to describe the previous 15 years assumes a level of mitigation that did not occur, thereby skewing subsequent assessments by lessening the severity of warming and associated physical climate risk."

Four scenarios known as Representative Concentration Pathways (RCPs) were developed in 2005 for the most recent Intergovernmental Panel on Climate Change Assessment Report (AR5). The RCP scenarios are used in global climate models, and include historical greenhouse gas emissions until 2005, and projected emissions subsequently. RCP 8.5 assumes the greatest fossil fuel use, and a resulting additional 8.5 watts per square meter of radiative forcing by 2100.

The commentary also emphasizes that while there are signs of progress on bending the global emissions curve and that our emissions picture may change significantly by 2100, focusing on the unknowable, distant future may distort the current debate on these issues. "For purposes of informing societal decisions, shorter time horizons are highly relevant, and it is important to have scenarios which are useful on those horizons. Looking at mid-century and sooner, RCP8.5 is clearly the most useful choice," they wrote.

The article also notes that RCP 8.5 would not be significantly impacted by the COVID-19 pandemic, adding that "we note that the usefulness of RCP 8.5 is not changed due to the ongoing COVID-19 pandemic. Assuming pandemic restrictions remain in place until the end of 2020 would entail a reduction in emissions of -4.7 Gt CO2. This represents less than 1% of total cumulative CO2 emissions since 2005 for all RCPs and observations."

"Given the agreement of 2005-2020 historical and RCP8.5 total CO2 emissions and the congruence between current policies and RCP8.5 emission levels to mid-century, RCP8.5 has continued utility, both as an instrument to explore mean outcomes as well as risk," they concluded. "Indeed, if RCP8.5 did not exist, we'd have to create it."

The COVID-19 pandemic has led to severe financial stress for both hospitals and physician practices, raising serious concerns that many may either close or be purchased by larger organizations. Such consolidation is well-recognized to lead to higher prices. Whether it will lead to better quality of care is less clear.

A new study published in the August Issue of Health Affairs, based on the first comprehensive national survey of physician practices, hospitals and health systems, found that larger, more integrated systems do not generally deliver better quality. "We looked at a broad range of quality measures and compared independent hospitals and practices with those owned by different kinds of health systems," said Elliott Fisher, MD, MPH, lead author and professor of medicine and health policy at Dartmouth. "In no case was ownership by larger, more complex health systems associated with better quality."

Another key finding from the study was the remarkable degree of variation in quality scores across hospitals and physician practices, regardless of whether they were independent or owned by larger systems. "This degree of variation points to tremendous opportunities to improve the quality of care in both hospitals and practices," said Stephen Shortell, PhD, Professor of the Graduate School, University of California, Berkeley. "We must continue to put in place the incentives and programs needed to drive improvement."

The research team assessed the degree to which hospitals and physician practices under several different ownership structures--including financial independence and financial integration with larger health systems--adopted care delivery and payment reforms intended to improve quality. They analyzed data from the National Survey of Healthcare Organizations and Systems, which included responses from 2,190 physician practices and 739 hospitals that were collected between June 2017 and August 2018. The surveys included questions about care for complex, high-need patients; participation in quality-focused payment programs; screening for clinical conditions and social needs; and use of registries and evidence-based guidelines.

"The policy implications of this research are clear," said Carrie Colla, PhD, professor of health policy and clinical practice at Dartmouth, who worked as a policy advisor in Congress during a recent sabbatical. "With Covid-19 wreaking financial havoc on smaller healthcare organizations, policy makers--both at the federal and state levels--should ensure that purchases of practices and hospitals adhere to current antitrust law. They should also consider financial support for those most threatened by the pandemic."

Published in Advanced Functional Materials, a University of Sydney team of biomedical engineers has developed a plasma technology to robustly attach hydrogels ­­- a jelly-like substance which is structurally similar to soft tissue in the human body - to polymeric materials, allowing manufactured devices to better interact with surrounding tissue.

To function optimally in the body, a manufactured implant - whether it be an artificial hip, a fabricated spinal disc or engineered tissue - must bond and interact with appropriate surrounding tissues and living cells.

When that doesn't happen an implant may fail or, worse still, be rejected by the body. Worldwide, implant failures and rejections are a significant cost to health systems, placing large financial and health burdens on patients.

The team, which was led by School of Biomedical Engineering, Dr Behnam Akhavan and Professor Marcela Bilek, successfully combined hydrogels including those made from silk with Teflon and polystyrene polymers.

"Despite being similar to the natural tissue of the body; in medical science hydrogels are notoriously difficult to work with as they are inherently weak and structurally unstable. They do not easily attach to solids which means they often cannot be used in mechanically demanding applications such as in cartilage and bone tissue engineering," said Dr Akhavan.

Hydrogels are highly attractive for tissue engineering because of their functional and structural similarity to human body soft tissue," said Biomedical Engineering PhD student Ms Rashi Walia, who carried out the research in collaboration with the University of Sydney's School of Physics and School of Chemical and Biomolecular Engineering, as well as Tufts University in Massachusetts, USA.

"Our group's unique plasma process, recently reported in ACS Applied Materials and Interfaces, enables us to activate all surfaces of complex, porous structures, such as scaffolds, to covalently attach biomolecules and hydrogels", said ARC Laureate and Biomedical Engineering academic, Professor Marcela Bilek.

"These advances enable the creation of mechanically robust complex-shaped polymeric scaffolds infused with hydrogel, bringing us a step closer to mimicking the characteristics of natural tissues within the body," said Professor Bilek.

"The plasma process is carried out in a single step, generates zero waste, and does not require additional chemicals that can be harmful to the environment."

Biomedical devices, organ implants, biosensors and tissue engineering scaffolds that are set to benefit from the new hydrogel technology.

"There are several scenarios in which this technology can be used. The gel could be loaded with a drug to release slowly over time, or it can be used to mimic structures such as bone-cartilage," said Dr Akhavan.

"These materials are also excellent candidates for applications such as lab-on-a-chip platforms, bioreactors that mimic organs, and biomimetic constructs for tissue repair as well as antifouling coatings for surfaces submerged in marine environments."

The research tested the material using biomolecules found in the body, which demonstrated a positive cellular response.

Dr Akhavan and the team will be progressing their area of research and will further develop the technology to combine hydrogels with non-polymeric solid materials, such as ceramics and metals.

MANHATTAN, KANSAS -- Yunjeong Kim and Kyeong-Ok "KC" Chang, virologists in the College of Veterinary Medicine at Kansas State University, have published a study showing a possible therapeutic treatment for COVID-19.

Pathogenic coronaviruses are a major threat to global public health, as shown by severe acute respiratory syndrome coronavirus, or SARS-CoV; Middle East respiratory syndrome coronavirus, known as MERS-CoV; and the newly emerged SARS-CoV-2, the virus that causes COVID-19 infection.

The study, "3C-like protease inhibitors block coronavirus replication in vitro and improve survival in MERS-CoV-infected mice," appears in the Aug. 3 issue of the prestigious medical journal Science Translational Medicine. It reveals how small molecule protease inhibitors show potency against human coronaviruses. These coronavirus 3C-like proteases, known as 3CLpro, are strong therapeutic targets because they play vital roles in coronavirus replication.

"Vaccine developments and treatments are the biggest targets in COVID-19 research, and treatment is really key," said Chang, professor of diagnostic medicine and pathobiology. "This paper describes protease inhibitors targeting coronavirus 3CLpro, which is a well-known therapeutic target."

The study demonstrates that this series of optimized coronavirus 3CLpro inhibitors blocked replication of the human coronaviruses MERS-CoV and SARS-CoV-2 in cultured cells and in a mouse model for MERS. These findings suggest that this series of compounds should be investigated further as a potential therapeutic for human coronavirus infection.

Chang and Kim have been using National Institutes of Health grants to develop antiviral drugs to treat MERS and human norovirus infections. Their work extends to other human viruses such as rhinoviruses and SARS-CoV-2.

"The work that this group of collaborators has been doing on antivirals and inhibitors for SARS and MERS at K-State for a number of years has been vital to their ability to quickly pivot to emphasize research on SARS-CoV-2 virus and therapeutics," said Peter K. Dorhout, vice president for research at K-State.

Co-collaborators on the research include teams lead by Bill Groutas at Wichita State University, Stanley Perlman at the University of Iowa and Scott Lovell at the University of Kansas.

"Drs. Groutas, Perlman and Lovell brought decades of experience to our research team," Chang said. "We would not have been able to come this far without important collaborations with our colleagues at other institutions."

"Getting things published right now is very important for the scientific community," Kim said. "I think we are adding valuable information to the antiviral field."

Prey can evade predators and also avoid attacks. However, some can escape after a successful attack, that is, from inside a predator after being swallowed. For example, some animals that can survive predators' digestive systems are excreted in feces and thereby escape, albeit in a passive manner. Now, for the first time, research has documented the quick, active escape of prey from the body of a predator after being eaten.

Kobe University ecologist SUGIURA Shinji found that the aquatic beetle Regimbartia attenuata can actively escape from the vent of the frog Pelophylax nigromaculatus via the digestive system (Fig. 1; Movie: https://youtu.be/qbefo_vUzog). Furthermore, his laboratory experiments suggest that the beetle can promote frog excretion to facilitate its escape. His research appears in the 3 August 2020 issue of Current Biology.

Many frog species lack teeth and are unable to kill prey before swallowing it. Therefore, frogs' digestive systems play an important role in killing prey. To investigate the defenses of insects against frogs, Sugiura provided frogs with various insect species.

The aquatic beetle species R. attenuata and frog species P. nigromaculatus are frequently found in the same paddy fields in Japan (Fig. 1). Because P. nigromaculatus preys on various terrestrial and aquatic insects, this frog species can attack R. attenuata under field conditions. To investigate the responses of R. attenuata to P. nigromaculatus, Sugiura provided R. attenuata adults (body length 3.8-5.0 mm) to juvenile and adult P. nigromaculatus (snout-vent length 22.5-74.2 mm) under laboratory conditions. All adults were easily swallowed by the frogs. However, 93.3% of the swallowed beetles were excreted within 6 h (0.1-3.5 h) after being swallowed (Figs. 1-3). Surprisingly, all excreted beetles were alive and active.

These observations indicate that swallowed R. attenuata move toward the frog vent through the digestive system. P. nigromaculatus always excreted the undigested parts of prey (except live R. attenuata ) > 24 h after swallowing them (Fig. 3). Because the frog's sphincter muscle pressure keeps the vent closed, the tiny beetles are unable to exit through the vent without inducing the frog to open it. Therefore, R. attenuata may stimulate the frog's gut to promote excretion. The same behavior was observed when R. attenuata was swallowed by four other frog species: Pelophylax porosus, Glandirana rugosa, Fejervarya kawamurai, and Hyla japonica (Fig. 2).

This study is the first to report the successful escape of prey insects from the vent of a predator and to suggest that the prey promotes predator excretion to escape from inside the predator's body.