Tech

Using a novel technique, scientists working at the Florida State University-headquartered National High Magnetic Field Laboratory have found evidence for a quantum spin liquid, a state of matter that is promising as a building block for the quantum computers of tomorrow.

Researchers discovered the exciting behavior while studying the so-called electron spins in the compound ruthenium trichloride. Their findings, published today in the journal Nature Physics , show that electron spins interact across the material, effectively lowering the overall energy. This type of behavior -- consistent with a quantum spin liquid -- was detected in ruthenium trichloride at high temperatures and in high magnetic fields.

Spin liquids, first theorized in 1973, remain something of a mystery. Despite some materials showing promising signs for this state of matter, it is extremely challenging to definitively confirm its existence. However, there is great interest in them because scientists believe they could be used for the design of smarter materials in a variety of applications, such as quantum computing.

This study provides strong support that ruthenium trichloride is a spin liquid, said physicist Kim Modic, a former graduate student who worked at the MagLab's pulsed field facility and is now an assistant professor at the Institute of Science and Technology Austria.

"I think this paper provides a fresh perspective on ruthenium trichloride and demonstrates a new way to look for signatures of spin liquids," said Modic, the paper's lead author.

For decades, physicists have extensively studied the charge of an electron, which carries electricity, paving the way for advances in electronics, energy and other areas. But electrons also have a property called spin. Scientists want to also leverage the spin aspect of electrons for technology, but the universal behavior of spins is not yet fully understood.

In simple terms, electrons can be thought of as spinning on an axis, like a top, oriented in some direction. In magnetic materials, these spins align with one another, either in the same or opposite directions. Called magnetic ordering, this behavior can be induced or suppressed by temperature or magnetic field. Once the magnetic order is suppressed, more exotic states of matter could emerge, such as quantum spin liquids.

In the search for a spin liquid, the research team homed in on ruthenium trichloride. Its honeycomb-like structure, featuring a spin at each site, is like a magnetic version of graphene -- another hot topic in condensed matter physics.

"Ruthenium is much heavier than carbon, which results in strong interactions among the spins," said MagLab physicist Arkady Shekhter, a co-author on the paper.

The team expected those interactions would enhance magnetic frustration in the material. That's a kind of "three's company" scenario in which two spins pair up, leaving the third in a magnetic limbo, which thwarts magnetic ordering. That frustration, the team hypothesized, could lead to a spin liquid state. Their data ended up confirming their suspicions.

"It seems like, at low temperatures and under an applied magnetic field, ruthenium trichloride shows signs of the behavior that we're looking for," Modic said. "The spins don't simply orient themselves depending on the alignment of neighboring spins, but rather are dynamic -- like swirling water molecules -- while maintaining some correlation between them."

The findings were enabled by a new technique that the team developed called resonant torsion magnetometry, which precisely measures the behavior of electron spins in high magnetic fields and could lead to many other new insights about magnetic materials, Modic said.

"We don't really have the workhorse techniques or the analytical machinery for studying the excitations of electron spins, like we do for charge systems," Modic said. "The methods that do exist typically require large sample sizes, which may not be available. Our technique is highly sensitive and works on tiny, delicate samples. This could be a game-changer for this area of research."

Modic developed the technique as a postdoctoral researcher and then worked with MagLab physicists Shekhter and Ross McDonald, another co-author on the paper, to measure ruthenium trichloride in high magnetic fields.

Their technique involved mounting ruthenium trichloride samples onto a cantilever the size of a strand of hair. They repurposed a quartz tuning fork -- similar to that in a quartz crystal watch -- to vibrate the cantilever in a magnetic field. Instead of using it to tell time precisely, they measured the frequency of vibration to study the interaction between the spins in ruthenium trichloride and the applied magnetic field. They performed their measurements in two powerful magnets at the National MagLab.

"The beauty of our approach is that it's a relatively simple setup, which allowed us to carry out our measurements in both a 35-tesla resistive magnet and a 65-tesla pulsed field magnet," Modic said.

The next step in the research will be to study this system in the MagLab's world-record 100-tesla pulsed magnet.

"That high of a magnetic field should allow us to directly observe the suppression of the spin liquid state, which will help us learn even more about this compound's inner workings," Shekhter said.

DURHAM, N.C. -- Even when a person suffering from malaria is burning up with fever and too sick to function, the tiny blood-eating parasites lurking inside them continue to flourish, relentlessly growing and multiplying as they gobble up the host's red blood cells.

The single-celled Plasmodium parasites that cause 200 million cases of malaria each year can withstand feverish temperatures that make their human hosts miserable. And now, a Duke University-led team is beginning to understand how they do it.

Assistant professor of chemistry Emily Derbyshire and colleagues have identified a lipid-protein combo that springs into action to gird the parasite's innards against heat shock.

Understanding how the malaria parasite protects its cells against heat stress and other onslaughts could lead to new ways to fight resistant strains, which have evolved ways to survive the drugs traditionally used to kill them, the researchers say.

Nearly half of the world's population is at risk of contracting malaria. The disease kills 400,000 people a year, most of them children.

Long before the cause of malaria was identified, the disease's harrowing fevers were well known. References to them have been found on 5,000-year-old clay tablets from ancient Mesopotamia. The Greek poet Homer wrote about their misery. Hippocrates too.

The Duke team, collaborating with professor of biological engineering Jacquin Niles at the Massachusetts Institute of Technology, wanted to know how the malaria parasites inside a person's body make it through these fevers unscathed.

When the parasites enter a person's bloodstream through the bite of an infected mosquito, the temperature around them jumps from the balmy mid-70s of the mosquito to 98.6 degrees in the human. The human host's body temperature can then rocket to 105 degrees or higher before dropping back down to normal two to six hours later, a roller coaster pattern that repeats itself every two to three days.

"It's like going from room temperature water to a hot tub," said first author Kuan-Yi Lu, who earned his Ph.D. in molecular genetics and microbiology in Derbyshire's lab at Duke.

For the paper, published Sept. 25 in the journal eLife, Lu spent hundreds of hours peering at parasites under the microscope, trying to figure out what happens inside them when temperatures seesaw.

To mimic malarial fever in the lab, the researchers placed malaria-infected red blood cells in an incubator heated to 104 degrees Fahrenheit for six hours before bringing them back down to normal body temperature, 98.6 degrees.

They found that when temperatures rise, the parasites produce more of a lipid molecule called phosphatidylinositol 3-phosphate, or PI(3)P.

This substance builds up in the outer wall of a tiny sac inside the parasite's cells called the food vacuole -- the protist's version of a gut. There, it recruits and binds to another molecule, a heat shock protein called Hsp70, and together they help shore up the food vacuole's outer walls.

Without this lipid-protein boost, the team found that heat can make the food vacuole start to leak, unleashing its acidic contents into the gel-like fluid that fills the cell and possibly even digesting the parasite from the inside.

The findings are important because they could help researchers make the most of existing malaria drugs.

Previous research has shown that malaria parasites with higher-than-normal PI(3)P levels are more resistant to artemisinins, the leading class of antimalarials. Since artemisinins were first introduced in the 1970s, partial resistance has been increasingly reported in parts of Southeast Asia, raising fears that we may be losing one of our best weapons against the disease.

But the Duke-led study raises the possibility that new combination therapies for malaria -- artemisinins combined with other drugs that reduce the parasite's PI(3)P lipid levels and disrupt the food vacuole's membrane -- could be a way to re-sensitize resistant parasites, breaking down their defenses so the malaria treatments we already have are effective again.

"If there is an alternative way to increase the permeability of the digestive vacuole, it could make the digestive vacuole more accessible to those drugs again," Lu said.

The findings also suggest caution in giving malaria patients ibuprofen for fever if they're already taking artemisinin-based compounds, Derbyshire said. That's because artemisinins kill malaria parasites by damaging their cell's survival machinery, including the machinery that makes PI(3)P. If artemisinins suppress PI(3)P levels, and thereby make malaria parasites more vulnerable to heat stress, then fever reducers could prolong the time it takes for artemisinin-based drugs to kill the parasites, as some reports have suggested.

Much remains to be learned, Derbyshire said. "There's more work to do to establish the mode of action. But you could imagine designing new combination therapies to try and extend the life of artemisinin and prolong its effectiveness," Derbyshire said.

BOSTON - The coronavirus (COVID-19) pandemic has caused widespread harm to the health and well-being of already vulnerable children and adolescents in the U.S., particularly those in low-income households and children of color. Nevertheless, evidence-based programs known to reverse the negative effects of poverty are being widely neglected, according to a new report in Health Affairs. Such programs include basic income supports, other family supports, and universal health care structured to meet family needs. A combination of these interventions could substantially reduce the risks children face from poverty and early adversity, say the authors.

"America's children are already less healthy than children in every other industrialized nation, and poverty is one of the most important factors that impact their health and well-being," says James M. Perrin, MD, investigator at MassGeneral Hospital for Children and a professor of pediatrics at Harvard Medical School. Perrin was the lead author of the report, which he prepared with pediatric health experts from several other institutions.

This report builds upon the work described in four earlier studies developed by the National Academies of Sciences, Engineering, and Medicine (NASEM) to identify interventions that strengthen child and adolescent health and well-being. Those reports, published in 2019, each reviewed an aspect of this question: poverty; mental, emotional and behavioral health; adolescence; and young family health and education.

Thanks to that and other work, experts now agree that early experiences profoundly affect children's physical, mental and emotional development with lasting consequences. Researchers have also established that child and adolescent health in the U.S. lags well behind that in almost all other advanced economies in terms of most indicators of well-being. The effects of these factors can last into adulthood, putting vulnerable children at life-long risk of disadvantage and keeping them from participating fully in the workforce.

Taken together, the four NASEM reports provide strong, evidence-based guidance to end persistent disadvantage among disadvantaged children and youth, say Perrin and his colleagues. Further, they looked at how effective specific strategies were.

One key study looked for strategies that could cut poverty in half over a ten-year period, noting that the estimated cost of ignoring child poverty is about $1 trillion per year. It found that none of the 20 program and policy ideas developed by the NASEM committee could do so alone, but that certain combinations -- such as providing key family tax credits, expanding nutritional assistance programs, and ensuring families had housing -- could. A combination with similar promise included tax credits, along with a child allowance and child support, an increase in the minimum wage, and eliminating restrictions on the eligibility of immigrants for programs.

The reports stress the key role of parents and other caregivers in the outcomes for children - and the need to assure the health and well-being of parents. They call for transformation of maternal and child health care to team care, addressing social drivers of health through stronger community linkages, and integrating mental and behavioral health. Now, the researchers say, there is an urgent need for policy makers and local governments to implement these interventions.

"Adolescents and children can overcome adversity," says Perrin. "But we need to address the long-lasting causes of poor health and give them their best opportunity by supporting children's social, mental and emotional development. The health and well-being of children and youth should be our top priority."

East Hanover, NJ. October 5, 2020. Lauren Strober, PhD, at Kessler Foundation recently published results of the first prospective study of employment and multiple sclerosis (MS). Dr. Strober compared two groups of individuals with MS - those 'at risk' and 'not at risk' for unemployment, examining the influences of multiple factors on the likelihood of staying in the workplace. The article, "Determinants of unemployment in multiple sclerosis (MS): The role of disease measures, person-specific factors, and engagement in positive health-related behaviors" was epublished on September 2, 2020 by Multiple Sclerosis and Related Disorders.

Link to abstract: https://tinyurl.com/y4gvyljc

Multiple sclerosis affects people aged 20 to 50 years, comprising the peak working years. More than 90% are in the workforce at the time of their diagnosis, but on average, only 30% to 45% are employed after diagnosis. Unemployment has a negative impact on individuals and their families, as well as on society, in terms of lost productivity. Moreover, there are several physical and mental health "costs" associated with one becoming unemployed. Examining the factors that contribute to individuals with MS leaving the workforce is essential to identifying people at risk, and finding ways to help them maintain employment.

For this prospective study, 252 individuals with MS aged 20 to 64, who were working full- or part-time, were recruited through the national and local chapters of the National MS Society. A survey administered at the outset of the study identified 67 participants at risk for unemployment, defined as considering reducing their hours or leaving their jobs in the near future. The 'at risk' and 'not at risk' groups were compared by disease measures, person-specific factors, and health-related behaviors.

"Individuals at risk tended to have progressive disease, more fatigue, poorer coping mechanisms, and less MS self-efficacy," reported Dr. Strober, senior research scientist in the Center for Neuropsychology and Neuroscience Research at Kessler Foundation. "They were also less likely to report engaging in positive behaviors such as healthful diets, exercise, and social and intellectual activities."

"Risk of unemployment is highest during the first three to five years after diagnosis, so we need to be able to intervene early to prevent job losses, and their subsequent impact on physical and mental health, as well as on personal and family finances. This study points to factors related to risk of unemployment that may be amenable to early intervention," said Dr. Strober. "While further research is needed, professionals who provide MS care should be aware of the potential impact of this diagnosis on future employment, and be prepared to intervene before individuals leave the work force."

NASA's Terra satellite obtained visible imagery of Tropical Storm Gamma being battered by outside winds in the south central Gulf of Mexico. Over the weekend of Oct. 3 and 4, Gamma tracked over Mexico's Yucatan Peninsula.

Tropical Depression 25 formed on Oct. 2 by 11 a.m. EDT over the northwestern Caribbean Sea. At the time of formation, NOAA's National Hurricane Center (NHC) issued warnings and watches for a portion of the Yucatan Peninsula of Mexico. By 8 p.m. EDT, the depression strengthened into a tropical storm and re-named Gamma.

Gamma brought heavy rainfall to the Yucatan Peninsula over the weekend of Oct. 3 and 4. On Oct. 3, NHC noted, "Surface observations and satellite images indicate that the center of Tropical Storm Gamma made landfall in the northeast Yucatan Peninsula near Tulum, Mexico, around 11:45 a.m. CDT (12:45 p.m. EDT). The storm was very close to hurricane strength at landfall, with maximum sustained winds near 70 mph (110 mph) with higher gusts."

The storm had weakened after tracking over the peninsula. By 5 p.m. EDT, Gamma's center had moved off the northern coast of the Yucatan Peninsula and appeared to be stalled. The storm did not move much by Oct. 5.

Watches and Warnings on Oct. 5

On Oct. 5, the NHC posted a warning and a watch. A Tropical Storm Warning is in effect for north and west of Cancun to Dzilam, Mexico A Tropical Storm Watch is in effect from west of Dzilam to Campeche, Mexico.

Gamma's Wind Shear Troubles  

The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Terra satellite captured a visible image of Tropical Storm Gamma on Oct. 5.

Gamma is a strongly sheared tropical storm that has been meandering just north of the northern coast of the Yucatan Peninsula of Mexico. The MODIS image revealed the strongest thunderstorms were pushed far to the north of the center of circulation by those outside winds (wind shear) from the south.

Infrared imagery showed that strong convective cloud tops colder than minus 80 degrees Celsius were more than 60 nautical miles north and northeast of the well-defined and fully exposed low-level circulation center. That southerly wind shear was pushing those strong storms north of the center.

NHC noted that the Decay SHIPS intensity computer forecast model does indicate a very brief period of decreasing wind shear magnitude just prior to landfall around the 24-hour period. Afterward, the shear, once again, increases and the storm will weaken.

The satellite imagery was created using NASA's Worldview product at NASA's Goddard Space Flight Center in Greenbelt, Md.

Gamma's Status on Oct. 5

At 2 p.m. EDT (1800 UTC), the center of Tropical Storm Gamma was located near latitude 22.3 degrees north and longitude 87.9 degrees west. It was centered about 135 miles (220 km) north-northwest of Cozumel, Mexico.

Gamma is moving toward the southwest near 4 mph (7 kph), and this general motion is expected to continue through Wednesday morning. Maximum sustained winds have decreased to near 40 mph (65 kph) with higher gusts.  The estimated minimum central pressure is 1003 millibars.

Key Messages

NHC issued two key messages about Gamma, as the storm is expected to continue affecting the Yucatan Peninsula:

Through midweek, Gamma is expected to produce an additional 3 to 6 inches of rainfall with isolated maximum amounts of 8 inches across portions of the Mexican states of Yucatan, Campeche, and Tabasco. This rainfall may produce significant flash flooding.

Tropical storm conditions are likely in portions of the Tropical Storm Warning area along the northern coast of the Yucatan Peninsula for a brief period this afternoon. Tropical Storm conditions are possible within the Tropical Storm Watch area.

Gamma's Forecast 

On the forecast track, the center of Gamma should move inland over the northwest coast of the Yucatan Peninsula Tuesday night and remain inland through Thursday. Gradual weakening is forecast, and Gamma is expected to become a depression this evening and degenerate to a post-tropical remnant low tonight.

The most significant advances in human civilization are marked by the progression of the materials that humans use. The Stone Age gave way to the Bronze Age, which in turn gave way to the Iron Age. New materials disrupt the technologies of the time, improving life and the human condition.

Modern technologies can likewise be directly traced to innovations in the materials used to make them, as exemplified by the use of silicon in computer chips and state-of-the-art steels that underpin infrastructure. For centuries, however, materials and alloy design have relied on the use of a base, or principal, element, to which small fractions of other elements are added. Take steel, for instance, in which tiny amounts of carbon added to the principal element iron (Fe), lead to improved properties. When small amounts of other elements are added, the steel can be tailored for, say, enhanced corrosion resistance or improved strength.

Dating back to an idea proposed in 2004, the past several years have witnessed the emergence of a new paradigm in alloy design, in which three or more elements are mixed in roughly equal proportions. Named multiprincipal element alloys (MPEAs), or often known as a subset of these alloys called high-entropy alloys, these materials blur the distinction between majority and minority populations of elements. This more perfect union of atomic partners that make up the collective material exhibit exciting properties that allow them to perform better than their traditional counterparts.

"Some of these materials exhibit exceptional combinations of strength, ductility and damage tolerance," writes a team of UC Santa Barbara researchers -- including materials professors Dan Gianola, Tresa Pollock and Irene Beyerlein, and postdoctoral researcher Fulin Wang -- and their co-authors in a paper published today in the journal Science. "Refractory alloys [made from a group of nine metal elements on the periodic table that are highly resistant to heat and wear] are attractive candidates for use at extremely high temperatures associated with many technology applications."

MPEAs motivated the development of refractory MPEAs, first made in 2010. But using multiple alloys almost infinitely increases the number of possible alloy "recipes." The sheer number of combinations that can be achieved sets the stage for the use of advanced computational screening and machine learning to target the materials subsets having the most interesting and desirable properties.

"For these ap­proaches to be successful, it is criti­cal that the alloy design process is guided by an understanding of the origins of the specific properties that are desired," writes Julie Cairney, a professor at the School of Aerospace, Mechanical and Mechatronic Engineering, at the University of Sydney, in Australia, in a companion piece.

In their Science paper, the UCSB team and colleagues at the University of Kentucky, the U.S. Naval Research Laboratory, and the U.S. Air Force Research Laboratory, suggest a way to enhance the ability to predict which alloys might have valuable properties.

Chief among such properties is an alloy's ability to deform, i.e. be molded or bent, without cracking and to maintain its material integrity under the excessive loads and the high heat found in extreme environments, such as in airplane wings, rocket engines and industrial turbines.

"On the atomic level, a material deforms, or changes its shape, as a result of moving atoms," explained Wang, a postdoc in Gianola's lab.

The crystalline structures of metals are made up of stacked planes of atoms organized into a highly regular grid. When a metal deforms, atoms move, or slide, over each other on the grid. The line separating the regions where atoms have moved and where they have not is called a dislocation. The properties of dislocations, including how easily and where they can move, therefore become very important to the deformation behaviors of the material.

Despite the advantages of MPE alloys, progress in designing them has been slow. While traditional trial-and-error approaches are inefficient, from about 2017, more research efforts were devoted to developing theories to try to identify the underlying reason that a particular alloy had desirable properties.

"But," Wang said, "there is a lack of experimental evidence to inform some critical elements of the theory. When I started working on this project, my immediate question was, what's special about the MPEAs compared to traditional alloys? Since we are interested in mechanical properties, we focus on the dislocations."

In this study, the researchers used electron microscopy to investigate the configurations of dislocations and unveil the mechanistic origins that give rise to desirable properties in a model alloy. Combined with the atomistic simulations from the group of Irene Beyerlein, they showed that the random field of different elements unlocks multiple pathways for dislocation movements, features not available in conventional alloys.

"For conventional dislocations, the force to break atomic bonds at a dislocation is single valued because all the atoms are alike," Beyerlein said. "For the MPE dislocation, this force cannot be deterministic. The structure of an MPE dislocation becomes redefined as it tries to move through randomly changing atomic environments.

"With our atomistic calculations, we took the approach of expecting the unexpected and probed not only the usual modes but additional higher modes of slip, typically neglected in the literature to date," she added. "We also performed thousands of calculations, which exposed just how widely varying this critical dislocation force can be and how favorable alternative higher modes of slip are."

The study is part of a larger collaborative effort led by Pollock and funded by the Office of Naval Research, named MPE.edu, that also involves UCSB researchers Carlos Levi and Anton van der Ven, aimed at gaining fundamental insights regarding how best to explore the vast refractory alloy space.

"While compositionally complex alloys have long been of interest to us, progress in exploring the large compositional space has been slow," said Pollock. "With the MPE project, we brought together a team that used emerging computational, machine learning, and experimental tools, which have enabled us to uncover new behaviors and rapidly explore new compositional domains. The very high melting points of the refractory materials of interest have made them notoriously difficult to fabricate and study in the past, but our new approaches, combined with the possibility of 3D printing, completely change the landscape."

"This work is emblematic of the true power of combining experiments with simulation and theory," Gianola said. "Many researchers pay lip service to this synergy, but this study could not have gone as far as it did without the constant back and forth between the experimental and simulation groups. The future looks very bright."

NASA's Aqua satellite provided an infrared view of Tropical Storm Marie that revealed the effects of outside winds battering the storm.

Wind shear occurs when winds at different levels of the atmosphere push against the rotating cylinder of winds, weakening the rotation by pushing it apart at different levels.

NASA's Aqua Satellite Reveals Effects of Wind Shear 

Infrared light is a tool used to analyze the strength of storms in tropical cyclones by providing temperature information about a system's clouds. The strongest thunderstorms that reach highest into the atmosphere have the coldest cloud top temperatures. This temperature information can also tell forecasters if the strongest storms in a tropical cyclone are being pushed away from the center, indicating wind shear.

On Oct.5 at 6:20 a.m. EDT (1020 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Aqua satellite gathered infrared data on Marie that confirmed wind shear was adversely affecting the storm. Westerly vertical wind shear has pushed strongest storms east of the center where cloud top temperatures are as cold as minus 50 degrees Fahrenheit (minus 45.5 Celsius). The remains of the deep convection associated with Marie continues to get further displaced from the exposed low-level center due strong upper-level westerly winds, with the gap now over 100 nautical miles between those two features.

Status of Tropical Storm Marie  

At 11 a.m. EDT (1500 UTC), the center of Tropical Storm Marie was located near latitude 21.1 degrees north and longitude 131.9 degrees west. Marie is moving toward the west-northwest near 9 mph (15 km/h), and this general motion, with a decrease in forward speed, is anticipated during the next couple of days followed by a turn to the west. Maximum sustained winds are near 60 mph (95 kph) with higher gusts.

Forecast for Marie

Continued weakening is expected and Marie is forecast to degenerate into a remnant low by Tuesday night.

EVANSTON, Ill. -- Northwestern University researchers are casting a net for nanoparticles.

The team has discovered a new, rapid method for fabricating nanoparticles from a simple, self-assembling polymer. The novel method presents new possibilities for diverse applications, including water purification, diagnostics and rapidly generating vaccine formulations, which typically require many different types of molecules to be either captured or delivered at the same time.

Using a polymer net that collapses into nanoscale hydrogels (or nanogels), the method efficiently captures over 95% of proteins, DNA or small molecule drugs -- alone or in combinations. By comparison, loading efficiency is typically between 5% and 20% for other nanoparticle delivery systems.

"We use a polymer that forms a wide net throughout an aqueous solution," said Northwestern's Evan A. Scott, who led the study. "Then we induce the net to collapse. It collects anything within the solution, trapping therapeutics inside of nanogel delivery vehicles with very high efficiency."

"It works like a fishing net, which first spreads out due to electrostatic repulsion and then shrinks upon hydration to trap 'fish,'" added Fanfan Du, a postdoctoral fellow in Scott's laboratory.

The paper was published last week (Sept. 29) in the journal Nature Communications.

Scott is the Kay Davis Professor of Biomedical Engineering at Northwestern's McCormick School of Engineering. Northwestern professors Monica Olvera de la Cruz and Vinayak Dravid coauthored the paper.

Molecules found in nature, such as DNA and peptides, can rapidly self-assemble and organize into diverse structures. Mimicking this process using human-made polymer systems, however, has remained limited. Previously developed processes for self-assembling drug delivery systems are time consuming, labor intensive and difficult to scale. The processes also tend to be woefully inefficient, culminating in a small fraction of the drug actually making it inside the delivery system.

"Clinical application of self-assembled nanoparticles has been limited by difficulties with scalability and with loading large or multiple therapeutics, especially proteins," Scott said. "We present a highly scalable mechanism that can stably load nearly any therapeutic molecule with high efficiency."

Scott's team found success by using a polypropylene sulfone (PPSU) homopolymer, which is highly soluble in dimethylsulfoxide (DMSO) solution, but forms electrostatic and hydrophilic aggregates in water. The aggregates are amphiphilic, which causes them to assemble into networks and eventually collapse into gels.

"Adding more water induces the network to collapse, leading to the formation of nanogels," Du said. "The manner in which water is added affects the PPSU chain formation, which changes the nanogels' size and structure."

Atomistic simulations -- performed by Baofu Qiao in the Olvera de la Cruz group -- confirmed that the nanostructures were stabilized by weak sulfone-sulfone bonding. Using coarse-grained simulations performed by Northwestern postdoctoral fellow Trung Dac Nguyen, the researchers observed the nanonet structures. This opens a new avenue for soft materials assembly by means of sulfone-sulfone bonding.

In addition to drug delivery applications, the researchers also believe the novel method could be used for water purification. The network could collapse to collect contaminants in water, leaving pure water behind.

A new study shows that the body size of the iconic gigantic or megatooth shark, about 15 meters (50 feet) in length, is indeed anomalously large compared to body sizes of its relatives.

Formally called Otodus megalodon, the fossil shark that lived nearly worldwide roughly 15-3.6 million years ago is receiving a renewed look at the significance of its body size in the shark world, based on a new study appearing in the international journal Historical Biology.

Otodus megalodon is commonly portrayed as a super-sized, monstrous shark, in novels and films such as the 2018 sci-fi thriller "The Meg," but it is known that the scientifically justifiable maximum possible body size for the species is about 15 meters (50 feet). Nonetheless, it is still an impressively large shark, and the new study illuminates exactly how uniquely gigantic the shark was, according to Kenshu Shimada, a paleobiologist at DePaul University in Chicago and lead author of the study.

Otodus megalodon belongs to the shark group called lamniforms with a rich fossil record, but the biology of extinct forms is poorly understood because these cartilaginous fishes are mostly known only from their teeth. Based on measurements taken from present-day non-planktivorous lamniforms, the study presents an equation that would allow estimations about the body length of extinct forms from their teeth. The study demonstrates that O. megalodon that reached about 15 meters (50 feet) is truly an outlier because practically all other non-planktivorous sharks have a general size limit of 7 meters (23 feet), and only a few plankton-eating sharks, such as the whale shark and basking shark, were equivalent or came close to the size. The study also reveals that the Cenozoic Era (after the age of dinosaurs, including today) saw more lamniform lineages attaining larger sizes than the Mesozoic (age of dinosaurs) Era.

Warm-bloodedness has previously been proposed to have led to the gigantism (over 6 meters, or 20 feet) in multiple lamniform lineages. The new study proposes their live-bearing reproductive strategy with a unique cannibalistic egg-eating behavior to nourish early-hatched embryos to large sizes inside their mother to be another possible cause for the frequent evolution of gigantism achieved by lamniform sharks.

Understanding body sizes of extinct organisms is important in the context of ecology and evolution. "Lamniform sharks have represented major carnivores in oceans since the age of dinosaurs, so it is reasonable to assert that they must have played an important role in shaping the marine ecosystems we know today," said Shimada.

"This is compelling evidence for the truly exceptional size of megalodon," noted co-author Michael Griffiths, a professor of environmental science at William Paterson University in Wayne, New Jersey. Co-author Martin Becker, also a professor of environmental science at William Paterson University, added, "this work represents a critical advancement in our understanding of the evolution of this ocean giant."

Most parents know or suspect when their child smokes, but they are much more likely to be in the dark if the child vapes or uses other tobacco products, according to a large national study by researchers at UC San Francisco.

The study, which tracked more than 23,000 participants aged 12 to 17 years old, found that parents or guardians were substantially less likely to report knowing or suspecting that their child had used tobacco if the child used only e-cigarettes, non-cigarette combustible products or smokeless tobacco, compared to smoking cigarettes or using multiple tobacco products.

The researchers also found that when parents set strong household rules about not using tobacco - applying to all residents - their children were less likely to start tobacco use. Just talking to kids about not smoking was far less effective. The study publishes at 9:01 p.m. PT, Oct. 4, 2020, in Pediatrics.

"We know that tobacco-free homes are a key tool to help prevent smoking by kids," said corresponding and senior author Benjamin Chaffee, DDS, MPH, PhD, an associate professor at the UCSF School of Dentistry. "What studies haven't examined is how tobacco-free homes stack up against other approaches and how much tobacco-free home rules might help with other tobacco products beyond smoking.

"Tobacco use by children is troubling, and dentists, like all healthcare providers, should be concerned about preventing youth tobacco use," Chaffee said.

Over the last decade, the smoking landscape has dramatically changed, especially among youth, for whom cigarette smoking has declined while use of electronic cigarettes soared. Last year, the Centers for Disease Control and Prevention reported that more than 1 in 4 high school students was vaping.

The new study used data from the Population Assessment of Tobacco and Health (PATH) Study to investigate parental awareness of youth tobacco use and the role of household tobacco rules in preventing smoking. In addition to cigarettes and e-cigarettes, the study looked at non-cigarette combustible products (including cigars, pipes, hookahs, and bidis), and smokeless tobacco (including snuff, chewing tobacco, snus, and dissolvable tobacco).

It found that parents were more likely to know or suspect that their child was using a tobacco or nicotine product if the child was older, male, identified as white, and lived with a tobacco user, as well as if the parents were less educated. Mothers were singled out as more aware than fathers.

The researchers also found that teens and tweens living in homes with the strictest rules prohibiting tobacco use were 20-26 percent less likely to start using tobacco, compared to youth living in the most permissive homes.

The investigators suggest that parents:

Don't smoke;

Create tobacco-free home environments that include all parts of the home;

Establish strict rules against all tobacco use that apply to all members of the household;

Have high-quality, clear communication with youth about not using tobacco.

"Low parental awareness of e-cigarette use belies rising public attention to youth vaping," said co-author Tsu-Shuan Wu, a student at the UCSF School of Dentistry. "Youth tobacco use is a considerable public health concern, regardless of the tobacco product used, and parents play a very important role in tobacco prevention.

"Creating tobacco-free home environments is one approach parents can use to set norms and expectations about tobacco use," she said. "And for healthcare providers, raising parental awareness should be part of overall guidance and tobacco-prevention support."

Super-micro, low-power sensors and devices that can send and receive signals and information anytime, anywhere will become an integral part of people's lives in a hyper-connected world driven by the Internet of Things (IoT). The question is how to continually supply electricity to the countless electronic devices connected to the system. This is because it is difficult to reduce the size and weight of the battery using the conventional way of charging and changing it.

What is believed to provide a fundamental solution to this problem is the triboelectric generator. It generates energy in a semi-permanent manner by inducing triboelectricity from contact between different materials, just as how static electricity is produced in everyday life.

The Korea Institute of Science and Technology (KIST) announced that a team of researchers led by Dr. Seoung-Ki Lee at the Center for Functional Composite Material Research developed a touch sensor that enhances the triboelectrification efficiency by more than 40% by forming crumple structured molybdenum disulfide through a joint study with Chang-Kyu Jeong, Professor of Advanced Materials Engineering at JeonBuk National University.

General triboelectric generators could not be applied to wearable electronic devices since they would become excessively large and heavy if their capacity was raised to generate sufficient electricity. To find a solution, there are studies being carried out that involve applying a two-dimensional semiconductor material that is atomically thin and has excellent physical properties as an active layer in generating triboelectricity.

The intensity of the triboelectricity generated varies according to the type of two materials coming in contact. When it came to the two-dimensional materials used in the past, the transfer of electric charges with the insulating material did not occur smoothly, thus substantially lowering the output of energy produced from triboelectricity.

The joint research team formed by KIST and Jeonbuk National University adjusted the properties of molybdenum disulfide (MoS2), a two-dimensional semiconductor, and changed its structure to boost the triboelectricity generation efficiency. The material was crumpled during a strong heat treatment process that is applied in a semiconductor manufacturing process, and this resulted in a material with wrinkles to which internal stress has been applied. Due to the wrinkles, which help increase the contact area per unit area, the surface-crumpled MoS2 device can generate around 40% more power than a flat counterpart. Not only that, the triboelectricity output was maintained at steady levels in a cyclic experiment even after 10,000 repetitions.

By applying the crumpled two-dimensional material developed as above to a touch sensor that can be used in a touchpad or touchscreen display, the joint research team came up with a lightweight and flexible self-powered touch sensor that can be operated without a battery. This type of touch sensor with high power generation efficiency is sensitive to stimulation and can recognize touch signals even at a small level of force, without any electric power.

Dr. Seoung-Ki Lee from KIST said, "Controlling the internal stress of the semiconductor material is a useful technique in the semiconductor industry, but this was the first time that a material synthesis technique involving synthesis of a two-dimensional semiconductor material and application of internal stress at the same time was implemented" "It presents a way to increase the triboelectricity generation efficiency by combining the material with a polymer, and it will serve as a catalyst for the development of next-generation functional materials based on two-dimensional substances."

Archaeologists have uncovered a warrior burial in Berkshire that could change historians' understanding of southern Britain in the early Anglo-Saxon era.

The burial, on a hilltop site near with commanding views over the surrounding Thames valley, must be of a high-status warlord from the 6th century AD, archaeologists from the University of Reading believe.

The 'Marlow Warlord' was a commanding, six-foot-tall man, buried alongside an array of expensive luxuries and weapons, including a sword in a decorated scabbard, spears, bronze and glass vessels, and other personal accoutrements.

The pagan burial had remained undiscovered and undisturbed for more than 1,400 years until two metal detectorists, Sue and Mick Washington came across the site in 2018.

Sue said: "On two earlier visits I had received a large signal from this area which appeared to be deep iron and most likely not to be of interest. However, the uncertainty preyed on my mind and on my next trip I just had to investigate, and this proved to be third time lucky!"

Sue, who along with other members of the Maidenhead Search Society metal detecting club had visited the site several times previously, initially unearthed two bronze bowls. Realising the age and significance of the find, she stopped digging and the Club, in line with best practice, registered this discovery with the Portable Antiquities Scheme. (PAS).

The PAS Finds Liaison Officer for Buckinghamshire undertook a targeted excavation to recover the very fragile bronze vessels and, in the process, recovered a pair of iron spearheads suggested that the context was likely to be an Anglo-Saxon grave.

Thanks to their actions, the bowls and spearheads were identified and conserved, and following Sue's generous donation, are soon to go on display at Buckinghamshire Museum in Aylesbury.

Recognising the importance of the burial and the need for more detailed archaeological investigation, a team led by the Department of Archaeology at the University of Reading carried out a full survey and excavation in August 2020. The burial was at a very shallow depth, making the excavation crucial to protect it from farming activity.

Dr Gabor Thomas, a specialist in early medieval archaeology at the University of Reading, said: "We had expected to find some kind of Anglo-Saxon burial, but what we found exceeded all our expectations and provides new insights into this stretch of the Thames in the decades after the collapse of the Roman administration in Britain.

"This the first burial of its kind found in the mid-Thames basin, which is often overlooked in favour of the Upper Thames and London. It suggests that the people living in this region may have been more important than historians previously suspected.

"This guy would have been tall and robust compared to other men at the time, and would have been an imposing figure even today. The nature of his burial and the site with views overlooking the Thames suggest he was a respected leader of a local tribe and had probably been a formidable warrior in his own right."

The early Anglo-Saxon period was one of great change in England with significant levels of immigration from the continent and the formation of new identities and power structures in the vacuum created by the collapse of the Roman administration around 400 AD. Around a century later - the period in which the Marlow Warlord lived -England was occupied by local tribal groupings, some of which expanded into Anglo-Saxon kingdoms, such as Wessex, Mercia and Kent.

The region of the mid-Thames between London and Oxford was previously thought to be a 'borderland' in this region, with powerful tribal groups on each side. This new discovery suggests that the area may have hosted important groups of its own. It is likely that the area was later squeezed out or absorbed into the larger neighbouring proto-kingdoms of Kent, Wessex and Mercia.

A team involving archaeologists from the University of Reading and local volunteer groups carried out a two-week excavation of the site in August 2020 with the kind permission of the supportive landowner. This activity included geophysical survey, test excavations, and a full excavation of the grave site.

Found buried with the Marlow Warlord were a sword with an exceptionally well-preserved scabbard - making it one of the best-preserved sheathed swords known from the period -made of wood and leather with decorative bronze fittings, spears, bronze and glass vessels, dress-fittings, shears and other implements.

These objects are currently being conserved by Pieta Greaves of Drakon Heritage and Conservation. Further analysis of the human remains will be carried out at the Department of Archaeology, University of Reading, to help determine the man's age, health, diet and geographical origins.

Michael Lewis, Head of the British Museum's Portable Antiquities Scheme, said: "This is a great example of archaeologists and metal-detectorists working together. Especially important is the fact that the finders stopped when they realised they had discovered something significant and called in archaeological assistance. By doing so they ensure much more could be learnt about this interesting burial."

Michael Lewis, Head of the British Museum's Portable Antiquities Scheme, said: "This is a great example of archaeologists and metal-detectorists working together. Especially important is the fact that the finders stopped when they realised they had discovered something significant and called in archaeological assistance. By doing so they ensure much more could be learnt about this interesting burial."

The team are now hoping to raise funds to pay for further conservation work, to allow some of the finds to go on display to the public at the Buckinghamshire Museum in 2021, when their newly refurbished permanent galleries re-open.

To donate, visit https://reading.hubbub.net/p/marlowwarlord

CHICAGO - Artificial intelligence (AI) used in machine learning models can predict which patients are at highest risk for severe pain after surgery, and help determine who would most benefit from personalized pain management plans that use non-opioid alternatives, suggests new research being presented at the ANESTHESIOLOGY® 2020 annual meeting.

Some patients experience more severe pain after surgery and need higher doses of opioids for longer periods of time, which increases their risk for opioid abuse disorder. By knowing which patients are at higher risk for severe post-surgical pain, physician anesthesiologists can create an anesthesia plan using non-opioid alternatives - such as nerve blocks, epidurals and other medications - to more effectively address pain and reduce the need for opioids.

Currently physicians use time-consuming questionnaires to identify patients at higher risk for severe post-surgical pain, asking about their history of anxiety, sleep quality and depression. In this study, researchers sought a faster, more effective method using machine learning, where a system learns and evolves based on data it is provided. They created three machine learning models that analyzed patients' electronic medical records, which identified that younger age, higher body mass index, female gender, pre-existing pain and prior opioid use were the most predictive factors of post-surgical pain.

"We plan to integrate the models with our electronic medical records to provide a prediction of post-surgical pain for each patient," said Mieke A. Soens, M.D., lead author of the study and an anesthesiologist at Brigham and Women's Hospital and anesthesiology instructor at Harvard Medical School, Boston. "If the patient is determined to be at high risk for severe post-surgical pain, the physician anesthesiologist can then adjust the patient's anesthesia plan to maximize non-opioid pain management strategies that would reduce the need for opioids after surgery."

In the two-part study, researchers looked at data from 5,944 patients who had a wide variety of surgeries, including gallbladder removal, hysterectomy, hip replacement and prostate surgery. Of those, 1,287 (22%) had consumed 90 morphine milligram equivalent (MME) in the first 24 hours after surgery, which is considered a high dose. In the first part of the study, they used 163 potential factors to predict high pain post-surgery, based on a literature search and consultation with experts. From there they created three machine learning algorithm models (logistical regression, random forest and artificial neural networks) that mined the patients' medical records and whittled the 163 predictor factors down to those which most accurately predicted patients' pain severity and potential opioid needs after surgery.

In the second part, they compared what the models predicted to actual opioid use in those same patients. They determined all three models had similar predictive accuracy overall: 81% for logistical regression and random forest methods and 80% for artificial neural networks. That means the models accurately identified which people were more likely to have severe pain and need higher doses of opioids about 80% of the time.

"Electronic medical records are a valuable and underused source of patient data and can be employed effectively to enhance patients' lives," said Dr. Soens. "Selectively identifying patients who typically need high doses of opioids after surgery is important to help reduce opioid misuse."

CHICAGO - When it comes to surgery, minority children lag far behind white children, according to two analyses of large national databases being presented at the ANESTHESIOLOGY® 2020 annual meeting. One found Black children are more than twice as likely as white children to die following surgical complications that require an unplanned additional operation. Another study determined Black, Asian and Hispanic children are about half as likely to have surgery as white children.

“All parents want the best medical care for their children, and ensuring that quality surgical care is available for minority as well as white children will require a multifaceted solution,” said Ethan L. Sanford, M.D., lead author of one of the studies and assistant professor of anesthesiology and pain management at UT Southwestern Medical Center, Dallas. “Clearly we have a lot of work to do.”

Black children more likely to die after reoperation

Researchers at Nationwide Children’s Hospital in Columbus, Ohio, set out to better assess a surgical outcome known as “failure to rescue” in Black children. In this context, failure to rescue means the patient suffered a post-surgical complication that led to a second unplanned operation, but ultimately died. While previous studies have looked at racial disparities related to this outcome in children having heart surgery, this study looked at failure to rescue in all surgeries.

The researchers analyzed data from the American College of Surgeons’ National Surgical Quality Improvement Pediatric Participant Use Data file and found that of 276,917 children who had an inpatient surgical procedure between 2012 and 2017, 10,425 (8,409 white children and 2,016 Black children) suffered a complication that sent them back to the operating room. Two-hundred and nine children subsequently died, 135 white (1.6% of all white children who suffered a complication) and 74 Black (3.7% of all Black children who suffered a complication), meaning Black children were more than twice as likely to die.

They found the racial disparities in failure to rescue were greatest among the sickest children and when the reoperation occurred within four days of the initial surgery.

The researchers note there are many possible factors that lead to failure to rescue in Black children after surgery, including: socioeconomic status and access to quality care and preventive measures; and health risk factors, such as higher incidence of obesity, asthma and sleep apnea.

“We don’t fully understand all of the issues that place a Black child at greater risk and how all of these issues interact with each other,” said Brittany Willer, M.D., lead author of the study and a pediatric anesthesiologist at Nationwide Children’s Hospital. “Our study gives physician anesthesiologists and surgeons insight into those at highest risk to heighten their awareness of the most vulnerable patients during the early post-operative period, which may have the biggest immediate impact on easing racial disparities.”

Minority children less likely to have surgery than white children

Researchers at UT Southwestern Medical Center conducted the first study to assess the difference in the incidence of surgery between Black, Hispanic, Asian, and white children. They analyzed data from the National Health Interview Survey, which is conducted by the Centers for Disease Control and Prevention (CDC). The study included 227,025 children age 18 or younger, of whom 11,018 had received any type of inpatient or outpatient surgery within the previous 12 months.

Even after adjusting for factors, such as the health of the child, poverty, whether the child was insured and the level of education attained by the parents, minority children were about half as likely as white children to have surgery. The authors note there is no evidence to suggest that white children are more likely to need surgery or to have cosmetic procedures – factors that potentially could play a role in the large difference between the two groups.

“We must consider implicit systemic biases within perioperative health care,” said Dr. Sanford. “Bias can occur at several points, from deciding whether to refer a child to a surgeon, when a surgeon is deciding whether or not to operate on a child and when a physician anesthesiologist is deciding whether it is safe for a child to proceed with surgery. Further, some minority families may mistrust the health system, there may be communication or cultural difficulties, as well as barriers such as travel and the ability to take time off work.”

Dr. Sanford said he hopes the research will help lead to broader health disparities research, such as routine collection of race and ethnicity data for children during all health care visits. Also important are quality improvement initiatives such as standardized teaching for health care workers about systemic bias and cultural competency, as well as increasing workforce diversity.

ASA’s Committee on Professional Diversity recently posted a “living” document, “Anesthesiology and Health Equity,” which looks into health care disparities in resources, quality of care, outcomes and mortality based on race and socioeconomic status. The committee anticipates the document will be reviewed and updated as new insights and perspectives on the issue are brought to its attention.

Microscopic fibres created during the laundry cycle can cause damage to the gills, liver and DNA of marine species, according to new research.

Scientists at the University of Plymouth exposed the Mediterranean mussel (Mytilus galloprovincialis), found in various locations across the world, to differing quantities of tumble dryer lint.

They demonstrated that increasing the amount of lint resulted in significant abnormality within the mussels' gills, specifically leading to damage of tissues including deformity, extensive swelling and loss of cilia. In the liver, the presence of lint led to atrophy or deformities leading to loss of definition in digestive tubules.

The increasing concentration of fibres also led to a reduction in the mussels' ability to filter food particles from the seawater and a significant increase in DNA strand breaks in the blood cells.

Scientists say the precise causes of the effects are not wholly clear, but are likely to arise from the fibres themselves and chemicals present within them.

They say the findings are unlikely to solely apply to lint, as its properties are consistent with other textiles and fibres found commonly in waste water and throughout the marine environment.

The study, published in the journal Chemosphere, was conducted by academics in the School of Biological and Marine Sciences and School of Geography, Earth and Environmental Sciences.

Dr Andrew Turner, Associate Professor of Environmental Sciences, was the study's senior author and has previously conducted research highlighting the chemicals - including bromine, iron and zinc - found within lint.

He said: "The laundering of clothes and other textiles is among the most significant sources of synthetic microfibers within the environment. However, despite their known presence in a range of species, there have been very few studies looking in detail at their impact. This study shows for the first time what harm they can cause, and it is particularly interesting to consider that it is not just the fibres themselves which create issues but also the cocktail of more harmful chemicals which they can mobilise."

Co-author Awadhesh Jha, Professor in Genetic Toxicology and Ecotoxicology, added: "Mytilus species are commonly used to monitor water quality in coastal areas, and the damage shown to them in this study is a cause for significant concern. Given their genetic similarity to other species and the fact they are found all over the world, we can also assume these effects will be replicated in other shellfish and marine species. Damage to DNA and impairment of the filter feeding abilities would have potential impact on the health of the organisms and the ecosystem. That is particularly significant as we look in the future to increase our reliance on aquaculture as a global source of food."

This study is the latest research by the University in the field, with it being awarded a Queen's Anniversary Prize for Higher and Further Education in 2020 for its ground-breaking research and policy impact on microplastics pollution in the oceans.

That research has included work showing that washing clothes releases thousands of microplastic particles into environment, and that devices fitted to washing machines can reduce the fibres produced in laundry cycle by up to 80%. Scientists from the University have also showed that wearing clothes could release more microfibres to the environment than washing them.