Tech

Unconventional superconductors contain a number of exotic phases of matter that are thought to play a role, for better or worse, in their ability to conduct electricity with 100% efficiency at much higher temperatures than scientists had thought possible - although still far short of the temperatures that would allow their wide deployment in perfectly efficient power lines, maglev trains and so on.

Now scientists at the Department of Energy's SLAC National Accelerator Laboratory have glimpsed the signature of one of those phases, known as pair-density waves or PDW, and confirmed that it's intertwined with another phase known as charge density wave (CDW) stripes - wavelike patterns of higher and lower electron density in the material.

Observing and understanding PDW and its correlations with other phases may be essential for understanding how superconductivity emerges in these materials, allowing electrons to pair up and travel with no resistance, said Jun-Sik Lee, a SLAC staff scientist who led the research at the lab's Stanford Synchrotron Radiation Lightsource (SSRL).

Even indirect evidence of the PDW phase intertwined with charge stripes, he said, is an important step on the long road toward understanding the mechanism behind unconventional superconductivity, which has eluded scientists over more than 30 years of research.

Lee added that the method his team used to make this observation, which involved dramatically increasing the sensitivity of a standard X-ray technique known as resonant soft X-ray scattering (RSXS) so it could see the extremely faint signals given off by these phenomena, has potential for directly sighting both the PDW signature and its correlations with other phases in future experiments. That's what they plan to work on next.

The scientists described their findings today in Physical Review Letters.

Untangling superconductor secrets

The existence of the PDW phase in high-temperature superconductors was proposed more than a decade ago and it's become an exciting area of research, with theorists developing models to explain how it works and experimentalists searching for it in a variety of materials.

In this study, the researchers went looking for it in a copper oxide, or cuprate, material known as LSCFO for the elements it contains ­- lanthanum, strontium, copper, iron and oxygen. It's thought to host two other phases that may intertwine with PDW: charge density wave stripes and spin density wave stripes.

The nature and behavior of charge and spin stripes have been explored in a number of studies, but there had been only a few indirect glimpses of PDW - much like identifying an animal from its tracks - and none made with X-ray scattering techniques. Because X-ray scattering reveals the behavior of an entire sample at once, it's thought to be the most promising way to clarify whether PDW exists and how it relates to other key phases in cuprates, Lee said.

Over the past few years, the SSRL team has worked on increasing the sensitivity of RSXS so it could capture the signals they were looking for.

Postdoctoral researcher Hai Huang and SLAC staff engineer Sang-Jun Lee used the improved technique in this study. They scattered X-rays off LSCFO and into a detector, forming patterns that revealed what was going on inside the material. As they dropped the temperature of the material toward its superconducting range, spin stripes appeared and intertwined to form charge stripes, and those charge stripes were then associated with the emergence of two-dimensional fluctuations that are the hallmark of PDW.

The researchers said these results not only demonstrate the value of the new RSXS approach, but also support the possibility that the PDW is present not just in this material, but in all of the superconducting cuprates.

A research team led by Masaki Fujita at Tohoku University in Japan grew the high-quality LSCFO crystal used in the experiment and conducted preliminary tests on it there. The research was funded by the DOE Office of Science. SSRL is a DOE Office of Science user facility.

Survey of 3,536 healthcare workers suggests 67 percent are suffering burnout, but people who receive frequent COVID-19 tests are less likely to be burned out.

In a world-first, researchers from the Okinawa Institute of Science and Technology Graduate University (OIST) have captured an image showing the internal orbits, or spatial distribution, of particles in an exciton - a goal that had eluded scientists for almost a century.

Excitons are excited states of matter found within semiconductors - a class of materials that are key to many modern technological devices, such as solar cells, LEDs, lasers and smartphones.

"Excitons are really unique and interesting particles; they are electrically neutral which means they behave very differently within materials from other particles like electrons. Their presence can really change the way a material responds to light," said Dr. Michael Man, co-first author and staff scientist in the OIST Femtosecond Spectroscopy Unit. "This work draws us closer to fully understanding the nature of excitons."

Excitons are formed when semiconductors absorb photons of light, which causes negatively charged electrons to jump from a lower energy level to a higher energy level. This leaves behind positively charged empty spaces, called holes, in the lower energy level. The oppositely charged electrons and holes attract and they start to orbit each other, which creates the excitons.

Excitons are crucially important within semiconductors, but so far, scientists have only been able to detect and measure them in limited ways. One issue lies with their fragility - it takes relatively little energy to break the exciton apart into free electrons and holes. Furthermore, they are fleeting in nature - in some materials, excitons are extinguished in about a few thousandths of a billionth of a second after they form, when the excited electrons "fall" back into the holes.

"Scientists first discovered excitons around 90 years ago," said Professor Keshav Dani, senior author and head of the Femtosecond Spectroscopy Unit at OIST. "But up until very recently, one could generally access only the optical signatures of excitons - for example, the light emitted by an exciton when extinguished. Other aspects of their nature, such as their momentum, and how the electron and the hole orbit each other, could only be described theoretically."

However, in December 2020, scientists in the OIST Femtosecond Spectroscopy Unit published a paper in Science describing a revolutionary technique for measuring the momentum of the electrons within the excitons.

Now, reporting on 21st April in Science Advances, the team used the technique to capture the first ever image that shows the distribution of an electron around the hole inside an exciton.

The researchers first generated excitons by sending a laser pulse of light at a two-dimensional semiconductor - a recently discovered class of materials that are only a few atoms in thickness and harbor more robust excitons.

After the excitons were formed, the team used a laser beam with ultra-high energy photons to break apart the excitons and kick the electrons right out of the material, into the vacuum space within an electron microscope.

The electron microscope measured the angle and energy of the electrons as they flew out of the material. From this information, the scientists were able to determine the initial momentum of the electron when it was bound to a hole within the exciton.

"The technique has some similarities to the collider experiments of high-energy physics, where particles are smashed together with intense amounts of energy, breaking them open. By measuring the trajectories of the smaller internal particles produced in the collision, scientists can start to piece together the internal structure of the original intact particles," said Professor Dani. "Here, we are doing something similar - we are using extreme ultraviolet light photons to break apart excitons and measuring the trajectories of the electrons to picture what's inside."

"This was no mean feat," continued Professor Dani. "The measurements had to be done with extreme care - at low temperature and low intensity to avoid heating up the excitons. It took a few days to acquire a single image."

Ultimately, the team succeeded in measuring the exciton's wavefunction, which gives the probability of where the electron is likely to be located around the hole.

"This work is an important advancement in the field," said Dr. Julien Madeo, co-first author and staff scientist in the OIST Femtosecond Spectroscopy Unit. "Being able to visualize the internal orbits of particles as they form larger composite particles could allow us to understand, measure and ultimately control the composite particles in unprecedented ways. This could allow us to create new quantum states of matter and technology based on these concepts."

The Dead Sea Scrolls, discovered some seventy years ago, are famous for containing the oldest manuscripts of the Hebrew Bible (Old Testament) and many hitherto unknown ancient Jewish texts. But the individual people behind the scrolls have eluded scientists, because the scribes are anonymous. Now, by combining the sciences and the humanities, University of Groningen researchers have cracked the code, which enables them to discover the scribes behind the scrolls. They presented their results in the journal PLOS ONE on 21 April.

The scribes who created the scrolls did not sign their work. Scholars suggested some manuscripts should be attributed to a single scribe based on handwriting. 'They would try to find a "smoking gun" in the handwriting, for example, a very specific trait in a letter which would identify a scribe', explains Mladen Popović, professor of Hebrew Bible and Ancient Judaism at the Faculty of Theology and Religious Studies at the University of Groningen. He is also director of the university's Qumran Institute, dedicated to studying the Dead Sea Scrolls. However, these identifications are somewhat subjective and often hotly debated.

Scribes

That is why Popović, in his project The Hands that Wrote the Bible which was funded by the European Research Council, teamed up with his colleague Lambert Schomaker, professor of Computer Science and Artificial Intelligence at the Faculty of Science and Engineering. Schomaker has long worked on techniques to allow computers to read handwriting, often from historical materials. He also performed studies to investigate how biomechanical traits, like the way in which someone holds a pen or stylus, would affect handwriting.

In this study, together with PhD candidate Maruf Dhali, they focused on one scroll in particular: the famous Great Isaiah Scroll (1QIsaa) from Qumran Cave 1. The handwriting in this scroll seems near-uniform, yet it has been suggested it was made by two scribes sharing a similar writing style. So how could this be decided? Schomaker: 'This scroll contains the letter aleph, or "a", at least five thousand times. It is impossible to compare them all just by eye.' Computers are well suited to analyse large datasets, like 5,000 handwritten a's. Digital imaging makes all sorts of computer calculations possible, at the microlevel of characters, such as measuring curvature (called textural), as well as whole characters (called allographic).

Neural network

'The human eye is amazing and presumably takes these levels into account too. This allows experts to "see" the hands of different authors, but that decision is often not reached by a transparent process,' Popović says. 'Furthermore, it is virtually impossible for these experts to process the large amounts of data the scrolls provide.' That is why their results are often not conclusive.

The first hurdle was to train an algorithm to separate the text (ink) from its background (the leather or the papyrus). For this separation, or 'binarization', Dhali developed a state-of-the-art artificial neural network that can be trained using deep learning. This neural network keeps the original ink traces made by the scribe more than 2,000 years ago intact as they appear on the digital images. 'This is important because the ancient ink traces relate directly to a person's muscle movement and are person-specific', Schomaker explains.

Similarities

Dhali performed the first analytical test of this study. His analysis of textural and allographic features showed that the 54 columns of text in the Great Isaiah Scroll fell into two different groups that were not distributed randomly through the scroll, but were clustered, with a transition around the halfway mark.

With the remark that there might be more than one writer, Dhali then handed the data to Schomaker who then recomputed the similarities between the columns, now using the patterns of letter fragments. This second analytical step confirmed the presence of two different. Several further checks and controls were performed. Schomaker: 'When we added extra noise to the data, the result didn't change. We also succeeded in demonstrating that the second scribe shows more variation within his writing than the first, although their writing is very similar.'

Handwriting

In the third step, Popović, Dhali, and Schomaker have produced a visual analysis. They created 'heat maps' that incorporate all the variants of a character across the scroll. Then they produced an averaged version of this character for the first 27 columns and the last 27 columns. Comparing these two average letters by eye shows that they are different. This links the computerized and statistical analysis to human interpretation of the data by approximation, because the heatmaps are neither dependent nor produced from the primary and secondary analyses.

Certain aspects of the scroll and the positioning of the text had led some scholars to suggest that after column 27 a new scribe had started, but this was not generally accepted. Popović: 'Now, we can confirm this with a quantitative analysis of the handwriting as well as with robust statistical analyses. Instead of basing judgment on more-or-less impressionistic evidence, with the intelligent assistance of the computer, we can demonstrate that the separation is statistically significant.'

New window

In addition to transforming the palaeography of the scrolls - and potentially other ancient manuscript corpora - this study of the Great Isaiah Scroll opens up a totally new way to analyse the Qumran texts based on physical characteristics. Now, researchers can access the microlevel of individual scribes and carefully observe how they worked on these manuscripts.

Popović: 'This is very exciting, because this opens a new window on the ancient world that can reveal much more intricate connections between the scribes that produced the scrolls. In this study, we found evidence for a very similar writing style shared by the two Great Isaiah Scroll scribes, which suggests a common training or origin. Our next step is to investigate other scrolls, where we may find different origins or training for the scribes.'

In this way, it will be possible to learn more about the communities that produced the Dead Sea Scrolls. 'We are now able to identify different scribes', Popović concludes. 'We will never know their names. But after seventy years of study, this feels as if we can finally shake hands with them through their handwriting.'

What The Study Did: Researchers looked at whether short-term exposure to air pollution from a 2018 California wildfire was associated with changes in the number of clinic visits for eczema or itch and medications prescribed for eczema.

Authors: Maria L. Wei, M.D., Ph.D., of the University of California, San Francisco, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamadermatol.2021.0179)

Editor's Note: The article includes conflicts of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

The effects of the steadily increasing amount of plastic in the ocean are complex and not yet fully understood. Scientists at GEOMAR Helmholtz Centre for Ocean Research Kiel have now shown for the first time that the uptake of microplastics by zooplankton can have significant effects on the marine ecosystem even at low concentrations. The study, published in the international journal Nature Communications, further indicates that the resulting changes may be responsible for a loss of oxygen in the ocean beyond that caused by global warming.

Plastic debris in the ocean is a widely known problem for large marine mammals, fish and seabirds. These animals can mistake plastic objects, such as plastic bags, for similar-looking food items, such as jellyfish. Tiny zooplankton can also mistake very small plastic particles for food and ingest them either accidentally or by chance (when the particles have combined with organic particles).

The direct effects of such microplastic ingestion on zooplankton are poorly understood, but the broader effects on ecosystems of zooplankton replacing some of their food with plastic are much less well understood. Now, for the first time, a research team has used an Earth system model to simulate how zooplankton that ingest microplastics could affect the base of the ocean food web and nutrient cycling. The results, now published in the international journal Nature Communications, suggest that even low concentrations of microplastics can have a strong impact on ecosystems. "This influence is already sufficient to affect global nutrient cycling", says Dr Karin Kvale, lead author of the study.

"These findings are significant because there has long been scepticism in the scientific community that microplastic concentrations in the ocean are high enough to have any impact on nutrient cycling", says Dr Karin Kvale "Our study shows that even at levels present in the ocean today, it may already be the case if zooplankton replace some of their natural food with microplastics. If zooplankton eat the microplastics and thus take up less food, this can have far-reaching ecological effects that can, for example, lead to increased algal blooms via a reduction in feeding pressure that affect the oxygen content of the oceans almost as much as climate change", Kvale continues. These findings point to a new potential driver of human-induced ocean change that has not been considered before. However, Kvale points out that the results are "very preliminary" because little is yet known about how the base of the food web interacts with microplastic pollution. Further work on this topic is needed, she says, but the study provides strong motivation to expand the capacity of Earth system models to include pollution effects as a new driver of ocean change.

Most battery materials, novel catalysts, and storage materials for hydrogen have one thing in common: they have a structure comprised of tiny pores in the nanometer range. These pores provide space which can be occupied by guest atoms, ions, and molecules. As a consequence, the properties of the guest and the host can change dramatically. Understanding the processes inside the pores is crucial to develop innovative energy technologies.

Observing the filling process

So far, it has only been possible to characterise the pore structure of the substrate materials precisely. The exact structure of the adsorbate inside the pores has remained hidden. To probe this, a team from the HZB together with colleagues from the University of Hamburg, from Germany's national metrology institute PTB, and Humboldt-Universität zu Berlin combined for the first time two different X-ray methods applied in-situ during filling and emptying of the porous host. Doing so, they made the structure of the guest atoms alone visible.

Model system: Mesoporous Silicon with Xenon

The team examined the process on a model system made of mesoporous silicon. The noble gas xenon was brought into contact with the silicon sample in a custom-made physisorption cell under temperature and pressure control. They examined the sample using anomalous small-angle X-ray scattering (ASAXS) and X-ray absorption near-edge structure (XANES) spectroscopy simultaneously, near the X-ray absorption edge of the guest xenon. In this way, they were able to sequentially record how xenon migrates into the pores. They could observe that the atoms first form a monoatomic layer on the pores' inner surfaces. Further layers are added and undergo rearrangements until the pores are filled. It gets clear that the filling and emptying of the pores proceed through different mechanisms with distinct structures.

Signal of the Xenon guests extracted

"Using conventional X-ray scattering (SAXS), you mainly see the porous material, the contributions of the guests are hardly visible", says Eike Gericke, first author of the study, who is doing his PhD on X-ray techniques. "We changed that by using ASAXS and measured at the X-ray absorption edge of xenon. The interactions between xenon and the X-ray beam change at this edge, so we can mathematically extract the signal of the xenon guests."

Empirical insight into confined matter

"This gives us for the first time direct access to an area that previously could only be speculated about", explains Dr. Armin Hoell, a corresponding author of the paper. "Applying the combination of these two X-ray methods to the process now makes it possible to observe the behaviour of matter confined in nanostructures empirically. This is a powerful new tool to gain deeper insights into battery electrodes, catalysts, and hydrogen storage materials."

The lifestyle and eating habits of human groups that have lived for thousands of years can be examined by tooth. An international research group analyzed the prehistoric findings of the Neolithic Age. In addition to providing knowledge about the lifestyles of people who lived in prehistoric times, a novel study of tooth remains paved the way for other methods previously not used. This study applies the complementary approaches of stable isotope and dental microwear analyses to study the diets of past people living in today's Hungary. Their joint results were published in the scientific journal Scientific Reports.

The Great Hungarian Plain is considered one of the most interesting areas for archeology because of its central geographic position in the European continent. The area played a key role in the spread and development of farming across Europe and was the meeting point for eastern and western European cultures. As such, it was a major cultural and technological transitional region throughout prehistory. But despite being a rich archeological region, few studies have analyzed the diets of the past people living in today's Hungary. In this context, researchers from the Catalan Institute of Human Paleoecology and Social Evolution (IPHES-CERCA) and the Universitat Rovira i Virgili (URV) in Tarragona (Spain), have carried out interdisciplinary research contributing new data about the evolution of the diets of the first agricultural and pastoral communities in Central Europe. This investigation has just been published in the journal Scientific Reports.

The study is focused on Great Hungarian Plain populations that lived from Middle Neolithic (5,500 - 5,000 BC) to Late Bronze Age (1,450 - 800 BC). Important changes in human diets occurred during this timeframe, influenced, most probably, by the socioeconomic, demographical and cultural transformations characterizing this period of some 5,000 years.

Raquel Hernando is a co-author of the paper carrying out her PhD studies with the URV and IPHES-CERCA and is beneficiary of a Marti-Franqueses Research Grant (URV2019PMF-PIPF-59). She says: "The demographic increase during the transition from Neolithic to Copper Age, produced changes in the settlement pattern and an increased focus on animal husbandry with a more reliance on cattle". And she adds "With the arrival of bronze metallurgy from the eastern steppe, significant changes occurred in the intensification of agriculture, with more hierarchical societies and fortified settlements".

All of these events took place at the same time over much of the European continent and
"...had implications on the dietary subsistence patterns of the human populations of that time" points out Beatriz Gamarra, a postdoctoral Beatriu de Pinós AGAUR Fellow and co-author of the paper in collaboration with other academics of research centres and universities from Ireland, Hungary and Portugal.

The team studied the diets of past human populations living in the Great Hungarian Plain from the Middle Neolithic and Late Bronze Age periods, demonstrating that, compared with subsequent periods, people consumed less abrasive and/or more processed foods during Middle Neolithic period. The Middle Neolithic people consumed meat and cereals (like wheat, einkorn and barley), although their diets varied between the sites. The researchers also found that, although other crops were consumed increasingly during the Middle Bronze Age (such as millet), this did not have any effects on the abrasiveness of the food and the way they processed it.

These results have been obtained from the same individuals using two approaches that were found to be complementary: stable isotope and dental microwear analyses. Each method is indicative of different dietary traits and few studies have combined both of them to infer ancestral diets. In this sense, Raquel Hernando states:

"The novelty of our study is that, thanks to the rich Hungarian archaeological human record, we have been able to employ both approaches on the same individuals, something that it has rarely been applied in previous studies, and has been developed in this exhaustive work".

Dental microwear analysis applied on molars provides information about the abrasiveness of the diets and the previous process of the foods consumed. Meanwhile, the stable isotopes study provides information about the origins of the animal proteins present in the ingested foods. Beatriz Gamarra highlights:

"We have demonstrated the complementary of these two techniques, which is not very common on this kind of research, as many of the archaeological context of the samples employed (such as collective burials) do not allow for this kind of combination on the same individuals' skeletal remains."

To carry out this research, a total of 89 individuals sampled from 17 archaeological sites dating to different periods and situated in the north-eastern part of the Great Hungarian Plain were employed. The material is stored in the Herman Ottó Museum in Miskolc, Hungary. Raquel Hernando specifies:

"From each individual, we have employed their teeth (first and second molars) for the microwear study, postcranial remains for the stable isotope analysis, and the petrous bone (inner ear) to perform ancient DNA analyses in order to biologically sex them ", specifies Raquel Hernando.

Dental microwear consists of quantifying a series of marks, such as striations and pits, formed on tooth enamel surfaces during the chewing process due to the presence in the foods of particles harder than tooth enamel. Using information from the microwear patterns, the abrasiveness of the food ingested and/or the previous process the foods might suffered before its consumption, can be inferred. To avoid damaging the original remains, molds of the teeth were made during the research stay of Raquel Hernando at the University College Dublin (UCD, Ireland). These molds were later analysed at the Servei de Recursos Cienífics I Tècnics facilities of the URV (at Seslades Campus, Tarragona).

The stable isotope analyses are based on the principle that the biochemical composition of the food consumed by animals is preserved in their body tissues. The carbon and nitrogen isotopic fractions were calculated from bone collagen and are indicative of the origin of the proteins consumed by the individuals a few years prior to their death. This research was carried out by Beatriz Gamarra at the School of Archaeology of University College Dublin (Ireland) thanks to funding from her previous MSCA (Marie Sk?odowska-Curie Actions) project.

For more sustainability on a global level, EU legislation should be changed to allow the use of gene editing in organic farming. This is what an international research team involving the Universities of Bayreuth and Göttingen demands in a paper published in the journal "Trends in Plant Science".

In May 2020, the EU Commission presented its "Farm-to-Fork" strategy, which is part of the "European Green Deal". The aim is to make European agriculture and its food system more sustainable. In particular, the proportion of organic farming in the EU's total agricultural land is to be increased to 25 percent by 2030. However, if current EU legislation remains in place, this increase will by no means guarantee more sustainability, as the current study by scientists from Bayreuth, Göttingen, Düsseldorf, Heidelberg, Wageningen, Alnarp, and Berkeley shows.

Numerous applications derived from new biotechnological processes are severely restricted or even banned by current EU law. This is especially true for gene editing, a new precision tool used in plant breeding. "Expanding organic farming further under the current legal restrictions on biotechnology could easily lead to less sustainability instead of more. Yet gene editing in particular offers great potential for sustainable agriculture," says Kai Purnhagen, lead author of the study and Professor of German & European Food Law at the University of Bayreuth.

Organic farming focuses on greater farming diversity and prohibits the use of chemical fertilisers and pesticides. Therefore, it can have a beneficial effect on environmental protection and biodiversity at the local level. However, compared to conventional farming, organic farming also delivers lower yields. Consequently, more land is needed to produce the same amount of high-quality food. "As global demand for high-quality food increases, more organic farming in the EU would lead to an expansion of agricultural land elsewhere in the world. This could easily result in environmental costs that exceed any local environmental benefits in the EU, as the conversion of natural land into agricultural land is one of the biggest drivers of global climate change and biodiversity loss," says co-author Matin Qaim, Professor of Agricultural Economics at the University of Göttingen.

The combination of organic farming and modern biotechnology could be a way to resolve this dilemma. "Gene editing offers unique opportunities to make food production more sustainable and to further improve the quality, but also the safety, of food. With the help of these new molecular tools, more robust plants can be developed that deliver high yields for high-quality nutrition, even with less fertiliser," says co-author Stephan Clemens, Professor of Plant Physiology at the University of Bayreuth and founding Dean of the new Faculty of Life Sciences: Food, Nutrition & Health on the Kulmbach campus. In addition, gene editing is used to breed fungus-resistant plants that thrive under organic farming without copper-containing pesticides. Copper is particularly toxic to soil and aquatic organisms, but its use to control fungi is nevertheless permitted in organic farming because of the lack of non-chemical alternatives to date. "Organic farming and gene editing could therefore complement each other very well and, combined, could contribute to more local and global sustainability," says Qaim.

However, the use of genetic engineering in organic farming requires legal changes at the EU level. "There is certainly no political majority for this at present, because genetic engineering is viewed very critically by many. Yet perhaps improved communication could gradually lead to greater societal openness, at least towards gene editing, because this form of genetic engineering enables very targeted breeding without having to introduce foreign genes into the plants. Highlighting this point could dispel many of the widespread fears of genetic engineering," says Purnhagen.

BETHESDA, Md. -- The COVID-19 pandemic heavily influenced spending on prescription drugs in the U.S. in 2020, according to the ASHP's (American Society of Health-System Pharmacists) National Trends in Prescription Drug Expenditures and Projections for 2021. Shifts in care related to the pandemic will continue to be a significant driver of drug expenditures in 2021, along with uptake in the use of biosimilars, a large pipeline of new cancer drugs, and increased approvals of specialty medications.

Prescription drug spending in 2020 grew at a moderate rate of 4.9% to $535.3 billion. Increased utilization drove the growth, which accounted for 2.9% of the total increase. Spending on new drugs accounted for 1.8% of the increase, and price changes accounted for 0.3%.

"Reflecting the overarching impact of COVID-19 on healthcare, ASHP's drug expenditures report illustrates the factors that can impact hospital and health-system budgets," said Daniel J. Cobaugh, Pharm.D., FAACT, DABAT, vice president of publishing at ASHP and editor-in-chief of AJHP. "We provide this annual report to help hospital and health-system leaders, policy makers, and others understand drug expenditure patterns to anticipate future growth and spending."

Drug expenditures in nonfederal hospitals declined 4.6%, while drug spending in home care settings increased 13%. Drug expenditures in nonfederal hospitals spiked in the three weeks immediately following the March 8, 2020, lockdown. Spending then dropped precipitously, remaining low for 19 weeks before rebounding. When those volatile early weeks of the pandemic are removed from the data, drug spending in hospitals showed modest growth compared to 2019.

Top drugs by overall spending were the immunosuppressive adalimumab for immune disorders such as arthritis and Crohn's disease; apixaban, a treatment to prevent blood clotting in patients with atrial fibrillation; and insulin glargine.

Many effects of the pandemic are likely to persist in 2021 and could have a dramatic impact on drug expenditures into 2022, said the report's lead author, Eric Tichy, Pharm.D., M.B.A., division chair, supply chain management at Mayo Clinic, Rochester, Minnesota. "Hospital and health-system pharmacy leaders should expect to continue suffering from drug expenditure whiplash in 2021 and beyond as they manage the implications from COVID-19, including the commercial availability of new high-cost drug therapies and shifts in site of care throughout the evolution of the pandemic."

As drugs approved under emergency use authorizations transition to full Food and Drug Administration (FDA) approval, expenditures for agents like remdesivir and monoclonal antibody cocktails will move from the federal government to the sectors where care is delivered. Remdesivir exceeded expenditures for all drugs in nonfederal hospitals, despite it only being commercially available for the final three months of 2020. In addition, approvals for several new drugs for the management of COVID-19 will affect spending in coming years.

Hospitals and health systems are also likely to see a rebound of prescription drug expenditures resulting from higher utilization of acute care services due to patients' reluctance to get preventative care during the pandemic.

The report also predicts the expanded use of biosimilars over innovator products will serve as a powerful deflationary force on drug expenditures for the foreseeable future. Expected approvals of new biosimilars for adalimumab, ranibizumab, and pegfilgrastim in 2021 and 2022, will increase competition and may cause further reductions in expenditures.

Other factors expected to influence prescription drug spending in 2021 include a large pipeline of new cancer drugs, the development of treatments for rare diseases, and expected FDA approval for several specialty drugs. The growth in spending on specialty drugs continues to outpace the rest of the market and could exceed 50% of overall drug expenditures in 2021. Efforts by payers to implement site-of-care restrictions will push more use of high-cost specialty drugs out of hospitals and into lower-cost sites, including ambulatory infusion centers and homecare.

The report is published online ahead of print at https://academic.oup.com/ajhp/advance-article-abstract/doi/10.1093/ajhp/zxab160/6242438?redirectedFrom=fulltext and will appear in print in the July 15 edition of AJHP.

Brandi Wren was studying social distancing and infections before masking tape marks appeared on the grocery store floor and plastic barriers went up in the post office.

Wren, a visiting scholar in the Department of Anthropology at Purdue University, spent a year studying wild vervet monkey troops in South Africa, tracking both their social grooming behavior and their parasite load. Her results, some of which were published Wednesday (April 21) in PLOS ONE showed evidence that monkeys carrying certain gastrointestinal parasites do not groom others as much as those without the parasite, and that routes of transmission may not be as clear cut as biologists think.

With implications for both animal behavior and human health, Wren's results open new avenues for research and new ways to consider old research. Vervet monkeys share surprising similarities with humans. In addition to sharing more than 90% of human DNA -- something that is true of all primate species -- vervet monkeys have also been known to exhibit conditions more familiar in humans than in other animals, including anxiety and hypertension. Biologists have found that studying vervet monkey physiology, genetics and behavior can shed light on some aspects of human biology.

"We have so many behavioral similarities; the roots and nuances of social behavior tend to be similar across all of the primates, especially from monkeys to humans," Wren said. "This study shows some of those similarities down to, when we feel sick, we don't want to talk to anybody. 'You can rub my back, whatever, but I really want to be left alone.' We see a lot of similarities in how humans and monkeys interact within their own groups."

Wild animals typically carry a nominal load of parasites. Biologists have long assumed that these infections are innocuous -- that they are asymptomatic and don't significantly affect either the animal's health or prospects. Even more interesting is that the parasites Wren was studying --whipworm, or Trichuris -- are not parasites that are typically spread through social contact. These are gastrointestinal parasites that are usually spread through contaminated soil or substances in the environments. But Wren's research shows that they may be spread through social contact and that they can significantly affect an individual's social behavior.

"Infected individuals show a little bit of lethargy, but the interesting thing is that they still let other individuals groom them; they just don't groom others," Wren said. "They also don't cuddle with the other monkeys as much. It appears they just don't feel well."

Wren and her team followed three troops of vervet monkeys, Chlorocebus pygerythrus, throughout their range in the Loskop Dam Nature Preserve in South Africa. By exhaustively cataloging individual monkeys' interactions and grooming habits and by cross-referencing that with infection information from fecal samples, Wren and her team were able to disentangle that monkeys infected with whipworm spent less time grooming other monkeys. They accepted grooming -- when it was offered -- but did not offer to groom their troop-mates back.

Wren notes that this difference in behavior is not so stark that it is noticeable just by observing the monkeys. Only by rigorously observing grooming behavior, exhaustively studying fecal samples and analyzing those results in relation to each other, was Wren able to decode this relationship.

"There's no way we would have been able to tell which monkeys were infected just from observation," Wren said. "There are no other signs of the infection, other than the social behavior. And the change is often so hard to detect. It takes following one individual for a substantial time and collecting the data to see it. The effect is hidden in this complex web of interactions."

Wren posits that her discovery is important for animal researchers to bear in mind. As studies of animal personalities begin to gain popularity, she stressed the importance of incorporating information like parasite load and hormone profiles into those studies. Otherwise, biologists might misattribute behaviors to personality traits when really the culprit is an active infection.

"There are some individuals you watch and you think, 'Gosh, this guy is such a jerk! He always lets everybody groom him, but he doesn't groom anybody else!'" Wren said. "What we're attributing to personality or attitude could just be because he has a gut full of parasites."

Wren draws parallels between the troop's behavior and human behavior during the pandemic. Like the monkeys, humans crave social contact, though more in the form of handshakes, high-fives and hugs. Like the monkeys, humans can spread diseases through social contact and tend to withdraw a bit during an illness. Unlike the monkeys, however, humans understand about contagion, about hygiene and about the importance of reducing contact or increasing cleanliness.

"All these social behaviors affect health on a practical level," Wren said. "We know COVID-19 is spread through close social contact. A fascinating thing about studying other species, and one reason to observe and understand them, is that we are always learning new things. There is always more to learn. Even when we're looking at previous research, even when we thought we understood the results, we still may not know the whole picture."

Scientists have found fragments of titanium blasting out of a famous supernova. This discovery, made with NASA's Chandra X-ray Observatory, could be a major step in pinpointing exactly how some giant stars explode.

This work is based on Chandra observations of the remains of a supernova called Cassiopeia A (Cas A), located in our galaxy about 11,000 light-years from Earth. This is one of the youngest known supernova remnants, with an age of about 350 years.

For years, scientists have struggled to understand how massive stars - those with masses over about 10 times that of the Sun - explode when they run out of fuel. This result provides an invaluable new clue.

"Scientists think most of the titanium that is used in our daily lives -- such as in electronics or jewelry -- is produced in a massive star's explosion," said Toshiki Sato of Rikkyo University in Japan, who led the study that appears in the journal Nature. "However, until now scientists have never been able to capture the moment just after stable titanium is made."

When the nuclear power source of a massive star runs out, the center collapses under gravity and forms either a dense stellar core called a neutron star or, less often, a black hole. When a neutron star is created, the inside of the collapsing massive star bounces off the surface of the stellar core, reversing the implosion.

The heat from this cataclysmic event produces a shock wave - similar to a sonic boom from a supersonic jet - that races outwards through the rest of the doomed star, producing new elements by nuclear reactions as it goes. However, in many computer models of this process, energy is quickly lost and the shock wave's journey outwards stalls, preventing the supernova explosion.

Recent three-dimensional computer simulations suggest that neutrinos -- very low-mass subatomic particles -- made in the creation of the neutron star play a crucial role in driving bubbles that speed away from the neutron star. These bubbles continue driving the shock wave forward to trigger the supernova explosion.

With the new study of Cas A, the team discovered powerful evidence for such a neutrino-driven explosion. In the Chandra data they found that finger-shaped structures pointing away from the explosion site contain titanium and chromium, coinciding with iron debris previously detected with Chandra. The conditions required for the creation of these elements in nuclear reactions, such as the temperature and density, match those of bubbles in simulations that drive the explosions.

The titanium that was found by Chandra in Cas A and that is predicted by these simulations is a stable isotope of the element, meaning that the number of neutrons its atoms contain implies that it does not change by radioactivity into a different, lighter element. Previously astronomers had used NASA's NuSTAR telescope to discover an unstable isotope of titanium in different locations in Cas A. Every 60 years about half of this titanium isotope transforms into scandium and then calcium.

"We have never seen this signature of titanium bubbles in a supernova remnant before, a result that was only possible with Chandra's incredibly sharp images," said co-author Keiichi Maeda of Kyoto University in Japan. "Our result is an important step in solving the problem of how these stars explode as supernovae."

"When the supernova happened, titanium fragments were produced deep inside the massive star. The fragments penetrated the surface of the massive star, forming the rim of the supernova remnant Cas A," said co-author Shigehiro Nagataki of the RIKEN Cluster for Pioneering Research in Japan.

These results strongly support the idea of a neutrino-driven explosion to explain at least some supernovae.

"Our research could be the most important observational result probing the role of neutrinos in exploding massive stars since the detection of neutrinos from Supernova 1987A," said co-author Takashi Yoshida of Kyoto University in Japan.

Astronomers used over a million and half seconds, or over 18 days, of Chandra observing time from Cas A taken between 2000 and 2018. The amount of stable titanium produced in Cas A exceeds the total mass of the Earth.

These results have been published in the April 22, 2021 issue of Nature. In addition to Sato, Maeda, Nagataki and Yoshida, the authors of the paper are Brian Grefenstette (California Institute of Technology in Pasadena, California), Brian J. Williams (NASA Goddard Space Flight Center in Greenbelt, Maryland), Hideyuki Umeda (University of Tokyo in Japan), Masaomi Ono (RIKEN Cluster for Pioneering Research in Japan), and Jack Hughes (Rutgers University in Piscataway, New Jersey).

NASA's Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science from Cambridge Massachusetts and flight operations from Burlington, Massachusetts.

RESEARCH TRIANGLE PARK, N.C. -- With Army funding, scientists invented a way to make compostable plastics break down within a few weeks with just heat and water. This advance will potentially solve waste management challenges at forward operating bases and offer additional technological advances for American Soldiers.

The new process, developed by researchers at University of California, Berkeley and the University of Massachusetts Amherst, involves embedding polyester-eating enzymes in the plastic as it's made.

When exposed to heat and water, an enzyme shrugs off its polymer shroud and starts chomping the plastic polymer into its building blocks -- in the case of biodegradable plastics, which are made primarily of the polyester known as polylactic acid, or PLA, it reduces it to lactic acid that can feed the soil microbes in compost. The polymer wrapping also degrades.

The process, published in Nature, eliminates microplastics, a byproduct of many chemical degradation processes and a pollutant in its own right. Up to 98% of the plastic made using this technique degrades into small molecules.

"These results provide a foundation for the rational design of polymeric materials that could degrade over relatively short timescales, which could provide significant advantages for Army logistics related to waste management," said Dr. Stephanie McElhinny, program manager, Army Research Office, an element of the U.S. Army Combat Capabilities Development Command, known as DEVCOM, Army Research Laboratory. "More broadly, these results provide insight into strategies for the incorporation of active biomolecules into solid-state materials, which could have implications for a variety of future Army capabilities including sensing, decontamination, and self-healing materials."

The new process to break down compostable plastics involves embedding polyester-eating enzymes in the plastic as it's made. When exposed to heat and water, the enzyme shrugs off its polymer shroud and starts chomping the plastic polymer into its building blocks -- in the case of PLA, reducing it to lactic acid, which can feed the soil microbes in compost.

Plastics are designed not to break down during normal use, but that also means they don't break down after they're discarded. Compostable plastics can take years to break down, often lasting as long as traditional plastics.

The research teams embedded nanoscale polymer-eating enzymes directly in a plastic or other material in a way that sequesters and protected them until the right conditions to unleash them. In 2018, they showed how this works in practice. The team embedded in a fiber mat an enzyme that degrades toxic organophosphate chemicals, like those in insecticides and chemical warfare agents. When the mat was immersed in the chemical, the embedded enzyme broke down the organophosphate.

The researchers said protecting the enzyme from falling apart, which proteins typically do outside of their normal environment, such as a living cell, resulted in the key innovation.

For the Nature paper, the researchers showcased a similar technique by enshrouding the enzyme in molecules they designed called random heteropolymers or RHPs, and embedding billions of these nanoparticles throughout plastic resin beads that are the starting point for all plastic manufacturing. The process is similar to embedding pigments in plastic to color them.

"This work, combined with the 2018 discovery, reveals these RHPs as highly effective enzyme stabilizers, enabling the retention of enzyme structure and activity in non-biological environments," said Dr. Dawanne Poree, program manager, ARO. "This research really opens the door to a new class of biotic-abiotic hybrid materials with functions only currently found in living systems."

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The results showed that the RHP-shrouded enzymes did not change the character of the plastic, which could be melted and extruded into fibers like normal polyester plastic at temperatures around 170 degrees Celsius (338 degrees Fahrenheit).

To trigger degradation, it was necessary only to add water and a little heat. At room temperature, 80% of the modified PLA fibers degraded entirely within about one week. Degradation was faster at higher temperatures. Under industrial composting conditions, the modified PLA degraded within six days at 50 degrees Celsius (122 degrees Fahrenheit).

Another polyester plastic, PCL (polycaprolactone), degraded in two days under industrial composting conditions at 40 degrees Celsius (104 degrees Fahrenheit). For PLA, the team embedded an enzyme called proteinase K that chews PLA up into molecules of lactic acid; for PCL, they used lipase. Both are inexpensive and readily available enzymes.

"If you have the enzyme only on the surface of the plastic, it would just etch down very slowly," said Ting Xu, UC Berkeley professor of materials science and engineering and of chemistry. "You want it distributed nanoscopically everywhere so that, essentially, each of them just needs to eat away their polymer neighbors, and then the whole material disintegrates."

Xu suspects that higher temperatures make the enshrouded enzyme move around more, allowing it to more quickly find the end of a polymer chain and chew it up and then move on to the next chain. The RHP-wrapped enzymes also tend to bind near the ends of polymer chains, keeping the enzymes near their targets.

The modified polyesters do not degrade at lower temperatures or during brief periods of dampness. For instance, a polyester shirt made with this process would withstand sweat and washing at moderate temperatures.

Soaking the biodegradable plastic in water for three months at room temperature did not cause it to degrade, but soaking for that time period in lukewarm water did.

Xu is developing RHP-wrapped enzymes that can degrade other types of polyester plastic, but she also is modifying the RHPs so that the degradation can be programmed to stop at a specified point and not completely destroy the material. This might be useful if the plastic were to be re-melted and turned into new plastic.

"Imagine, using biodegradable glue to assemble computer circuits or even entire phones or electronics, then, when you're done with them, dissolving the glue so that the devices fall apart and all the pieces can be reused," Xu said.

This technology could be very useful for generating new materials in forward operating environments, Poree said.

"Think of having a damaged equipment or vehicle parts that can be degraded and then re-made in the field, or even repurposed for a totally different use," Poree said. "It also has potential impacts for expeditionary manufacturing."

Making the speed of electronic technology as fast as possible is a central aim of contemporary materials research. The key components of fast computing technologies are transistors: switching devices that turn electrical currents on and off very quickly as basic steps of logic operations. In order to improve our knowledge about ideal transistor materials, physicists are constantly trying to determine new methods to accomplish such extremely fast switches. Researchers from the Fritz Haber Institute of the Max Planck Society in Berlin and the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg have now figured out that a novel type of ultrafast switch can be accomplished with light.

The physicists involved in the project are studying how to best get materials to change their properties - to make magnetic metals non-magnetic, for example, or to change the electric conductivity of a crystal. A material's electrical properties are strongly related to the arrangement of the electrons in the crystal. Controlling the electrons' arrangement has been a key topic for decades. Most control methods, however, are fairly slow. "We knew that external influences like temperature or pressure variations work", says Dr. Ralph Ernstorfer, Group Leader at the Department of Physical Chemistry at the Fritz Haber Institute, "but that takes time, at least a few seconds." Those who regularly use a smart phone or computer know that a few seconds can feel like eternity. So Dr. Ernstorfer's group explored how to switch material properties much faster by means of light.

Using brand new equipment at the Fritz Haber Institute, the researchers have massively cut down the switching time to only 100 femtoseconds - 0,000 000 000 000 1 of a second - by shooting ultrashort optical laser pulses at their chosen material, a semi-metallic crystal composed of tungsten and tellurium atoms. Shining light on the crystal encourages it to re-organize its internal electronic structure, which also changes the conductivity of the crystal. In addition, the scientists were able to observe exactly how its electronic structure changed. "We used a new instrument to take pictures of the transition every step of the way", explains Dr. Samuel Beaulieu, who worked as a postdoctoral fellow with Ralph Ernstorfer at the Fritz-Haber-Institut (2018-2020) and who is now a permanent researcher at the Centre Lasers Intenses et Applications (CELIA) at CNRS-Bordeaux University. "This is amazing progress - we used to only know what the electronic structure of the material looked like after, but never during the transition," he adds. Moreover, state-of-the-art modeling of this new process by Dr. Nicolas Tancogne-Dejean, Dr. Michael Sentef, and Prof. Dr. Angel Rubio from Max the Planck Institute for the Structure and Dynamics of Matter has revealed the origin of this novel type of ultrafast electronic transition. The laser pulse impinging on the materials changes the way electrons interact with each other. That is the driving force of this exotic transition, known as a Lifshitz transition.

This method is bound to generate a great deal of knowledge about possible future transistor materials. The fact alone that light can drive ultrafast electronic transitions is a first step towards even quicker and more efficient technology.

When deciding whether to have children, there are many factors to consider: finances, support systems, personal values. For a growing number of people, climate change is also being added to the list of considerations, says a University of Arizona researcher.

Sabrina Helm, an associate professor in the Norton School of Family and Consumer Sciences in the College of Agriculture and Life Sciences, is lead author of a new peer-reviewed study that looks at how climate change is affecting people's decisions about whether to have children.

"For many people, the question of whether to have children or not is one of the biggest they will face in their lives," Helm said. "If you are worried about what the future will look like because of climate change, obviously it will impact how you view this very important decision in your life."

Helm and her collaborators wanted to better understand the specific climate change-related reasons people have for not wanting to have children. They started by analyzing online comments posted in response to news articles written about the growing trend of people forgoing having children due to climate change concerns.

They then sought out adults ages 18 to 35 who said climate change plays an important role in their reproductive decision-making. They interviewed 24 participants about their concerns.

The researchers' findings, published in the journal Population and Environment, identify three major themes that emerged in both the online comments and the interviews.

1) Overconsumption. This was the most common concern expressed by interviewees, Helm said. Almost all participants said they worried about how children would contribute to climate change through an increased carbon footprint and overuse of resources that could become more scarce in the future, such as food and water.

2) Overpopulation. Overpopulation was the prevailing concern among online commenters, and it often came up in interviews as well, Helm said. Some participants said they felt having more than two children would be problematic and even selfish, as they would be "over-replacing" themselves and their partner. Some said they saw adoption as a more responsible choice. "Adoption was seen as the low-carbon alternative," Helm said.

3) An uncertain future. Interviewees and online commenters also frequently expressed a sense of doom about the future if climate change continues unchecked. Many said they would feel guilty or as if they were doing something morally or ethically wrong if they brought a child into a world with such an uncertain future.

While the "doom" perspective was prevalent, it was also balanced with expressions of hope, Helm said. Some interviewees and commenters said the very idea of children gives hope for a better and brighter future. Others expressed hope that future generations could contribute to environmental improvement by increasing climate change awareness and action.

"There was a hope that future generations will get the job done and makes things better," Helm said. "But that puts a lot of burden on small children."

Understanding how climate change affects reproductive decision-making is part of a larger effort by Helm and other researchers to understand how climate change is impacting individuals mentally and emotionally overall. Helm noted that climate change anxiety is on the rise, especially in younger people.

"Many people now are severely affected in terms of mental health with regard to climate change concerns," she said. "Then you add this very important decision about having kids, which very few take lightly, and this is an important topic from a public health perspective. It all ties into this bigger topic of how climate change affects people beyond the immediate effect of weather phenomena."

Helm said many study participants expressed anger and frustration that their concerns aren't taken seriously by family members and friends, who might dismissively tell them they will change their minds about having kids when they're older or meet the right person.

"It's still a bit taboo to even talk about this - about how worried they are - in an environment where there are still people who deny climate change," Helm said. "I think what's been lacking is the opportunity to talk about it and hear other people's voices. Maybe this research will help."