Brain

Thousands of chemical processes used by the energy industry and for other applications rely on the high speed of catalytic reactions, but molecules frequently are hindered by molecular traffic jams that slow them down. Now an entirely new class of porous catalysts has been invented, using unique fins to speed up the chemistry by allowing molecules to skip the lines that limit the reaction.

This discovery was published in Nature Materials, the leading journal of materials science.

The breakthrough focused on reducing barriers for molecules accessing the interior pores of catalysts, called zeolites - aluminosilicates with pores smaller than a nanometer. Zeolites are widely used in commercial processes as solid catalysts for the production of gasoline and value-added chemicals and other products.

In these applications, chemistry within the zeolite pores first requires molecules to find the small number of openings on the outside surface of catalyst particles. This creates a queue of molecules that must "wait in line" to enter the particle, diffuse to the active site involved in the chemical reaction, and then exit the particle.

One approach to address these transport problems has been to synthesize small nanoparticles. As zeolites become smaller, the amount of surface area exposing the pores increases per amount of catalyst material, which grants increased access for molecules entering the pores. Smaller particles also reduce the internal distance molecules must travel through the particle.

However, the synthesis of these smaller zeolite particles is expensive, and the resulting particles are often too inefficient for practical applications.

Researchers at the University of Houston, led by Jeffrey Rimer, Abraham E. Dukler Professor of chemical and biomolecular engineering, developed a way to induce larger catalyst particles to behave like nanoparticles - that is, to allow molecules to enter, spark a reaction and exit quickly, by growing protrusions, or fins, on the surfaces of catalyst particles. By adding nanoscale fins that protrude from the external surface of large particles, the roughened exterior of the particle significantly increased in surface area, granting molecules increased access and reducing the transport limitations that frequently plague conventional zeolite materials.

"Our new synthesis approach capitalizes on work we have been doing in our group for many years, focused on controlling zeolite crystallization in ways that enable the growth of fins," Rimer said. "This new class of materials bypasses the need to directly synthesize nanoparticles, creating a new paradigm in zeolite catalyst design."

Rimer worked with a team of international experts in materials synthesis, characterization and modeling to demonstrate the capability of finned zeolites to improve the performance of this unique family of solid catalysts. By comparing finned zeolites with conventional catalytic materials, they showed that zeolites with fins lasted almost eight times longer. Rimer said the incorporation of fins leads to shorter internal diffusion pathways and ensures molecules efficiently reach the reaction sites while reducing the propensity of carbon-based species to become immobilized. That build up ultimately deactivates the catalyst.

Xiaodong Zou, professor of inorganic and structural chemistry at Stockholm University, and members of her laboratory conducted advanced 3D electron microscopy characterization to unravel the pore structures of the finned crystals and confirmed that the fins were extensions of the underlying crystal and did not create impediments for internal diffusion.

"It is amazing to see how well all these hundreds of individual nanofins are aligned with the parent crystal," Zou said.

Additional state-of-the-art techniques for characterizing zeolite catalysts in real time were performed at Utrecht University by the research group of Bert Weckhuysen, professor of catalysis, energy and sustainability. These measurements confirmed the exceptional ability of finned zeolites to prolong catalyst activity well beyond that of larger catalysts.

Weckhuysen said the use of operando spectroscopy clearly showed how the introduction of fins lowered the amount of external coke deposits during catalysis. "That substantially increased the lifetime of finned zeolite crystals," he said.

Jeremy Palmer, assistant professor of chemical and biomolecular engineering at UH, used computational methods to model finned materials and explain how the new design works to improve catalysis.

Researchers had expected the fins would perform better than a standard-sized zeolite catalyst, he said. "But we found it was not just a 10% or 20% improvement. It was a tripling of efficiency. The magnitude of the improvement was a real surprise to us."

Additional work at the University of Minnesota by the research group of Paul Dauenhauer, professor of chemical engineering and materials science, and by Michael Tsapatsis, professor of chemical and biomolecular engineering at Johns Hopkins University, confirmed the enhanced mass transport properties of finned zeolites. Using a new method to track molecule diffusion by infrared light, the UM researchers demonstrated that the fins enhanced molecule transport between 100 and 1,000 times faster than conventional particles.

"The addition of fins allows molecules to get inside the channels of zeolites where the chemistry happens, but it also lets molecules quickly get out of the particle, which lets them operate for a much longer period of time," Dauenhauer said.

The discovery has immediate relevance to industry for a host of applications, including the production of fuels, chemicals for plastics and polymers, and reactions that make molecules for food, medicine and personal care products.

"The beauty of this new discovery is its potential generalization to a wide range of zeolite materials, using techniques that are easy to incorporate in existing synthesis processes," Rimer said. "The ability to control the properties of fins could allow for much greater flexibility in the rational design of zeolite catalysts."

A new UC Davis Health study found that common gastrointestinal (GI) symptoms such as diarrhea, constipation and bloating are linked to troubling sleep problems, self-harm and physical complaints in preschool children. According to the study, published Aug. 6 in Autism Research, these GI symptoms are much more common and potentially disruptive in young kids with autism.

"Clinicians and parents need to be aware of the high occurrence of GI problems in kids with autism," said Bibiana Restrepo, assistant clinical professor of pediatrics and first author on the study. "This study highlights the link between GI symptoms and some problematic behaviors we see in preschool-aged children."

Children with autism experience more gastrointestinal symptoms

Gastrointestinal concerns are frequently reported by parents of children with autism spectrum disorder (ASD). Researchers from the UC Davis MIND Institute evaluated the presence of GI symptoms in preschool-aged children with and without autism.

The study included 255 (184 males/71 females) children with ASD between two and 3.5 years of age and 129 (75 males/54 females) typically developing children in the same age group. Pediatricians specializing in autism interviewed caregivers during the children's medical evaluation. They asked the parents how often their children experienced GI symptoms such as difficulty swallowing, abdominal pain, bloating, diarrhea, constipation, painful stooling, vomiting, difficulty swallowing, blood in stool and blood in vomit.

The researchers grouped children in two categories: those who experienced one or more GI symptom and those who never or rarely had GI symptoms in the last three months. They compared the children in the two groups on measures of developmental, behavioral and adaptive functioning.

The study found that preschool-aged children with ASD were 2.7 times more likely to experience GI symptoms than their typically developing peers. In fact, almost 50% of children with ASD reported frequent GI symptoms - compared to 18% of children with typical development. Around 30% of the children with ASD experienced multiple GI symptoms.

Problem behaviors as an expression of GI discomfort in children

Multiple GI symptoms were associated with increased challenges with sleep and attention, as well as problem behaviors related to self-harm, aggression and restricted or repetitive behavior in both autistic and typically developing children. The severity of these problems was higher in children with autism.

"Problem behaviors may be an expression of GI discomfort in preschool-aged children," said Christine Wu Nordahl, associate professor at UC Davis MIND Institute and the department of psychiatry and behavioral sciences. "GI symptoms are often treatable, so it is important to recognize how common they are in children with autism. Treating their GI symptoms could potentially provide some relief to the kids and their parents."

The study found no link between GI symptoms and the children's cognitive development or gender. GI symptoms were equally common in male and female preschool children.

Denver--(Embargoed for 7 a.m. EST August 8, 2020)--Patients with non-small cell lung cancer (NSCLC) carrying anaplastic lymphoma kinase (ALK) gene alterations who received ensartinib experienced substantially longer progression-free survival than a matched group of patients who received crizotinib, according to a presentation at the International Association for the Study of Lung Cancer World Conference on Lung Cancer Virtual Presidential Symposium.

The results were presented today by Leora Horn, MD, Ingram Associate Professor of Cancer Research in the Division of Hematology/Oncology and director of the Thoracic Oncology Program at Vanderbilt-Ingram Cancer Center, Nashville, Tenn. View a video interview of Dr. Horn discussing the trial here: https://vimeo.com/444703327/6ad043dd00

ALK-positive lung cancer occurs in approximately 5% to 7% of patients with NSCLC, mostly in patients younger than age 55. Mutated forms of the ALK gene and proteins have also been found in other types of cancer, such as neuroblastoma, and anaplastic large cell lymphoma. These changes directly contribute to the uncontrolled growth of cancer cells.

Ensartinib (X-396) is a novel next-generation ALK tyrosine kinase inhibitor (TKI). According to Dr. Horn, in Phase 1 and 2 studies, ensartinib showed promising activity in patients with ALK+ NSCLC who were ALK TKI treatment naive or received prior crizotinib or second-generation ALK TKIs, including strong activity in patients with brain metastases.

Crizotinib is an anti-cancer drug acting as an ALK, MET, and ROS1 inhibitor, approved for treatment of some subtypes of patients with NSCLC (including ALK+) in the United States and other countries worldwide.

Dr. Horn and her colleagues at the participating cancer centers randomized 290 patients with ALK+ NSCLC to either ensartinib or crizotinib--the prespecified intent to treat (ITT) population with locally determined ALK+ NSCLC. Patients were stratified by prior chemotherapy, Eastern Cooperative Oncology Group performance status, brain metastases, and geographic region. Baseline characteristics were well balanced between the two groups: median age was 54.1; 26% of patients had prior chemotherapy, and 36% of patients had baseline brain metastases (5% had prior brain radiotherapy). The modified ITT population (the prespecified patient population that was ALK+ as confirmed by central Abbott FISH test) included 247 patients, of which 121 received ensartinib and 126 received crizotinib.

At the July 1, 2020 data cutoff, based on a pre-planned interim analysis design (at 75% of progression-free survival events) treatment was ongoing in 64 ensartinib-treated patients (45%) and 25 crizotinib-treated patients (17%). There were 139 patients who experienced disease progression (as assessed by blinded independent review committee, BIRC) or death, which represented 73% of progression events in the ITT population and 119 BIRC-events or deaths (63%) in the mITT population.

According to Dr. Horn, the trial's analysis demonstrated a statistically significant difference between patients who received ensartinib, with a median progression-free survival of 25.8 months compared with 12.7 months with crizotinib, with a median follow-up of 23.8 and 20.2 months, respectively (HR, 0.52; 95% CI, 0.36-0.75; P=.0003 by log-rank test). In the mITT population, the median progression-free survival has not been reached yet for the ensartinib arm vs. 12.7 months for the crizotinib arm (HR, 0.48; 95% CI, 0.32-0.71; P=.0002 by log-rank test).

The overall response rate was 75% versus 67% with crizotinib; among patients with measurable brain metastases, the BIRC-assessed intracranial overall response rate was 64% with ensartinib versus 21% with crizotinib.

The time-to-treatment-failure rate in the brain in patients with no baseline brain metastases was also significantly lower with ensartinib compared to crizotinib (4% vs 24% at 12 months).

"In patients with ALK-positive NSCLC, ensartinib significantly prolonged progression-free survival over crizotinib with a favorable safety profile, representing a new option in the first-line setting," Dr. Horn concluded.

"This is a remarkable achievement that gives patients with ALK+ lung cancer and treating physicians a safe and effective new treatment choice to control the disease before any other ALK TKI has been used. The study continues to follow patients that are on treatment and will be updated at upcoming conferences," said Li Mao, M.D. and CEO of Xcovery Holdings, Inc., the sponsor of the study.

In research published in Science Advances, a group led by scientists from the RIKEN Center for Emergent Matter Science (CEMS) have used a principle, "magneto-rotation coupling," to suppress the transmission of sound waves on the surface of a film in one direction while allowing them to travel in the other. This could lead to the development of "acoustic rectifiers"--devices that allow waves to propagate preferentially in one direction, with potential applications in communications technology.

Devices known as "rectifiers," are extremely important for our technological civilization. The best known are electronic diodes, which are used to convert AC into DC electricity, essentially making electrification possible.

In the current study, the group examined the movement of acoustic surface waves--movements of sound like the propagation of earthquakes over the surface of the earth--in a magnetic film. It is known that there is a interplay between the surface acoustic waves and "spin waves"--disturbances in magnetic fields within the material that can move through the material.

Acoustic surface waves can excite spin waves in two different ways. One, magneto-elastic coupling, is very well documented. However, a second, magneto-rotation coupling, was proposed more than forty years ago by Sadamichi Maekawa, one of the authors of the current study, but was not experimentally verified until now.

In the current study, the authors found that the two mechanisms occur at the same time but under different intensities. They found that when the magnetization of the magnetic specimen is rotating in the same direction of the surface acoustic waves, the energy of the acoustic surface waves is more efficiently transferred to the spin waves, increasing the rotation of the magnetization. In fact, the researchers were able to identify a configuration of unidirectional coupling where only the energy of surface acoustic waves in one direction could be transferred to the rotation of the magnetization. They also noticed that this "rectification" effect was more pronounced when the magnetic material contained magnetic anisotropy, meaning there was a preferred direction of internal magnetization even before the application of an external magnetic field.

According to Mingran Xu of RIKEN CEMS, the first author of the paper, "It was very exciting to show that the phenomenon of magneto-rotation coupling actually takes place, and that it can be used to completely suppress the movement of acoustic energy in one direction."

Jorge Puebla, also of RIKEN CEMS, says, "We hope that we can use this work to create an "acoustic diode" equivalent to the electronic diodes that are so important. We could relatively easily make a device where the acoustic energy is efficiently transfer in one direction but blocked in the other. This is happening at microwave frequencies, which is the range of interest for 5G communication technology, so surface acoustic waves may be an interesting candidate for this technology."

The ongoing COVID-19 pandemic is shining a bright spotlight on vaccine development. As numerous vaccines race through clinical trials, physicians and researchers continue to work on developing new vaccine technologies to generate the most effective vaccines with the fewest side effects.

A new proof-of-concept study by researchers at the University of Chicago and Duke University demonstrates the potential for one such platform, using self-assembling peptide nanofibers tagged with antigens to prime the immune system against a potential invasion.

Their research, published in Science Advances on August 7, 2020, showed that these nanofibers can induce an immune response and activate T cells without the use of additional adjuvants, which can induce inflammation and are associated with common vaccine side effects, like soreness at the injection site or low-grade fever.

"We wanted to understand how the body processed this nanofiber system, from its first interaction with the immune system to the point where it led to a complete immune response," said co-senior author Anita Chong, PhD, a professor of surgery at the University of Chicago Medicine. "In order to visualize the uptake of the nanofibers, we decided to try the intranasal route, because it would give us access to dendritic cells in the lungs and let us track their movement into the draining lymph nodes."

Lining the surfaces of the lungs and intestines, dendritic cells act as a first point of contact for the innate immune system. These cells bind to and gobble up the antigens found on the surface of invading pathogens, then turn around and present the antigens on their own cell surface to other immune system cells, including T and B cells. This allows the T cells to initiate an immune response and prepare to defend the body against the invading bacteria, fungus or virus.

In the study, the researchers leveraged their nanofiber platform to test a specific kind of vaccine, called a subunit vaccine, which only uses a specific protein intended to act as the main antigen to stimulate an immune response. This is in contrast to other kinds of vaccines, such as live-attenuated vaccines or inactivated vaccines, which challenge the immune system by introducing the whole virus, in a less virulent or inactive form.

Each type of vaccine has its advantages and disadvantages; live-attenuated vaccines can offer the most protection, but because they contain the actual pathogen, they frequently can't be used for patients with weakened immune systems.

"The major advantage of subunit vaccines is safety since they don't involve the replication of live pathogens," said first author Youhui Si, PhD, a research scientist at UChicago. "On the other hand, to increase their effectiveness, subunit vaccines require adjuvants and repeated doses to induce long lasting immunity against a disease."

Adjuvants have the big downside of provoking inflammation. "This makes it difficult to find the balance between getting a strong enough immune response and making the vaccine as safe and side effect-free as possible," said co-senior author Joel Collier, PhD, an associate professor of biomedical engineering at Duke University.

"The fiber we've developed is unique in that it doesn't require that inflammation," he continued. "The scaffolding itself seems to be able to activate the dendritic cells to kick off the immune response. But before now, we didn't have any real understanding of which pathways were involved in this process, so this study provides some insight into what's going on."

The researchers say that not requiring adjuvants has a lot of advantages. "Aside from the inflammation issues, adjuvants require vaccines to be kept in cold storage," Chong said. "Without them, the peptides are quite heat stable, and can be delivered as a dry powder to be reconstituted into nanofibers on site, making it easier to get vaccines into resource-limited areas."

The researchers believe that the primary strength of their nanofiber scaffolding is that it provides a physical structure that presents the antigens to the dendritic cells, making it easier for the innate immune system to recognize the antigens and begin a response.

"I think there has not been enough attention toward understanding the physical scaffolding surrounding antigens, and the information that scaffolding provides to the immune system," said Chong. "This system will let us start picking apart the signals that are delivered by a physical structure; are they complimentary to, or distinct from, the soluble chemical adjuvants?"

While the study was intended primarily to uncover the mechanism by which the nanofibers can induce an immune response, the results also demonstrate that this platform has great potential for generating safe, effective intranasal vaccines.

"We saw that the peptide fibers alone generated a strong immune response via the intranasal route," Collier said. "This route is great for vaccine compliance, because it doesn't involve a needle. Some people have a hard time with needles - including myself! They can induce a vasovagal response, causing people to lose consciousness, and it's difficult to control. Eliminating needles from a vaccine platform could help with this issue and may mean that more people will seek out the vaccine."

This platform would also allow physicians and scientists to more precisely dial in the immune response to provide the best protection against a disease. They provided the example of SARS-CoV-2, the novel coronavirus that causes COVID-19, as an example where being able to fine-tune the immune response and delivering the vaccine directly to the most affected tissues could be beneficial.

"We don't know yet which antigens will be most maximally protective against COVID-19," said Collier. "This would let us very precisely target and produce antibodies and T cells that will provide the most protection."

The researchers said that the intranasal platform and the similar sublingual platform, which involves spraying the vaccine under the tongue, have a lot of potential. "Not only are these routes needle-free, making it easier and more comfortable for people to access, but they can also elicit an immune response in the lungs or mucosal tissues directly," Chong said. "Many infections occur through the oral and respiratory routes, including COVID-19, so being able to trigger that immune response in the right area of the body is very helpful, and could make a vaccine more protective."

Helium is the second most abundant element in the universe after hydrogen. But scientists aren't sure just how much there actually is in the Sun's atmosphere, where it is hard to measure. Knowing the amount of helium in the solar atmosphere is important to understanding the origin and acceleration of the solar wind - the constant stream of charged particles from the Sun.

In 2009, NASA launched a sounding rocket investigation to measure helium in the extended solar atmosphere - the first time we've gathered a full global map. The results, recently published in Nature Astronomy, are helping us better understand our space environment.

Previously, when measuring ratios of helium to hydrogen in the solar wind as it reaches Earth, observations have found much lower ratios than expected. Scientists suspected the missing helium might have been left behind in the Sun's outermost atmospheric layer - the corona - or perhaps in a deeper layer. Discovering how this happens is key to understanding how the solar wind is accelerated.

To measure the amount of atmospheric helium and hydrogen, NASA's Helium Resonance Scattering in the Corona and Heliosphere, or HERSCHEL, sounding rocket took images of the solar corona. Led by the Naval Research Lab in Washington, D.C., HERSCHEL was an international collaboration with the Osservatorio Astrofisico di Torino in Italy and the Institute d'Astrophysique Spatiale in France.

HERSCHEL's observations showed that helium wasn't evenly distributed around the corona. The equatorial region had almost no helium while the areas at mid latitudes had the most. Comparing with images from ESA/NASA's Solar and Heliospheric Observatory (SOHO), the scientists were able to show the abundance at the mid latitudes overlaps with where Sun's magnetic field lines open out into the solar system.

This shows that the ratio of helium to hydrogen is strongly connected with the magnetic field and the speed of the solar wind in the corona. The equatorial regions, which had low helium abundance measurements, matched measurements from the solar wind near Earth. This points to the solar atmosphere being more dynamic than scientists thought.

The HERSCHEL sounding rocket investigation adds to a body of work seeking to understand the origin of the slow component of the solar wind. HERSCHEL remotely investigates the elemental composition of the region where the solar wind is accelerated, which can be analyzed in tandem with in situ measurements of the inner solar system, such as those of the Parker Solar Probe. While the heat of the Sun is enough to power the lightest element - ionized hydrogen protons - to escape the Sun as a supersonic wind, other physics must help power the acceleration of heavier elements such as helium. Thus, understanding elemental abundance in the Sun's atmosphere, provides additional information as we attempt to learn the full story of how the solar wind is accelerated.

In the future, scientists plan to take more observations to explain the difference in abundances. Two new instruments - Metis and EUI on board ESA/NASA's Solar Orbiter - are able to make similar global abundance measurements and will to help provide new information about the helium ratio in the corona.

The review, published in the British Ecological Society Journal People and Nature, is the first to focus on nature connection in children and adolescents. In the article Dr Chawla comprehensively reviews the full scope of literature on the topic, covering peer-reviewed articles, books and studies by environmental organizations.

The review finds that connecting with nature supports multiple areas of young people's wellbeing. "There is strong evidence that children are happier, healthier, function better, know more about the environment, and are more likely to take action to protect the natural world when they spend time in nature." said Dr Chawla.

Several studies found that children's connection with nature increased with time spent in natural environments. Time spent in this way was also a predictor for active care for nature in adulthood. These findings support strategies and policies that ensure that young people have access to wild areas, parks, gardens, green neighborhoods, and naturalized grounds at schools.

However, a connection with nature is not universally positive. "My review shows that connecting with nature is a complex experience that can generate troubling emotions as well as happiness." said Dr Chawla.

"We need to keep in mind that children are inheriting an unravelling biosphere, and many of them know it. Research shows that when adolescents react with despair, they are unlikely to take action to address challenges."

Thankfully the review finds that there is overlap in the strategies used to increase children's feelings of connection with nature and supporting them with difficult dimensions of this connection.

These strategies include helping young people learn what they can do to protect the natural world, as individuals and working collectively with others, and sharing examples of people who care for nature. Research covered in the review finds that young people are more likely to believe a better world is possible when friends, family and teachers listen sympathetically to their fears and give them a safe space to share their emotions.

One of the most surprising findings from the review was the complete disconnect between researchers studying the benefits of childhood connection to nature and those studying responses to environmental threats. "People who study children's connection with nature and those who study their coping with environmental risk and loss have been pursuing separate directions without referencing or engaging with each other." said Dr Chawla. "I am arguing that researchers on both sides need to be paying attention to each other's work and learning from each other".

A detailed study of roaming reactions - where atoms of compounds split off and orbit other atoms to form unexpected new compounds - could enable scientists to make much more accurate predictions about molecules in the atmosphere, including models of climate change, urban pollution and ozone depletion.

In a paper published today in the journal Science, a team of researchers from UNSW Sydney, University of Sydney, Emory University and Cornell University showed in unprecedented detail exactly what happens during roaming reactions of chemical compounds.

Professor Scott Kable, an atmospheric scientist who is also the head of UNSW's School of Chemistry, likens the study to lifting the hood on roaming reactions and seeing for the first time how the parts fit together. He says the study will give scientists new tools to understand the machinations of reactions in the atmosphere.

"Chemical reactions, where atoms are rearranged to make new substances, are occurring all the time in our atmosphere as a result of natural emission from plants and animals as well as human activity," Prof Kable says.

"Many of the key reactions in the atmosphere that contribute to photochemical smog and the production of carbon dioxide are initiated by sunlight, which can split molecules apart.

"For a long time, scientists thought these reactions happened in a simple way, that sunlight was absorbed and then the molecule explodes, sending atoms in different directions.

"But, in the last few years it was found that, where the energy from the sun was only just enough to break a chemical bond, the fragments perform an intimate dance before exchanging atoms and creating new, unanticipated, chemical products - known as roaming reactions.

"Our research shows these 'roaming' reactions exhibit unusual and unexpected features."

Prof Kable says in an experiment detailed in the paper, the researchers looked at the roaming reaction in formaldehyde (CH2O) and were surprised to see instead, two quite distinct signals, "which we could interpret as two distinct roaming mechanisms".

The theoretical and computational work was performed by a team in the US led by Professors Joel Bowman (Emory) and Paul Houston (Cornell). Prof Bowman observed that "detailed modelling of these reactions not only agree with the experimental findings, they provide insight into the motion of the atoms during the reaction".

Professor Meredith Jordan from University of Sydney says the experiments and theory results suggest roaming reactions straddle the classical and quantum worlds of physics and chemistry.

"Analysing the results with the incredible detail in both experiments and simulations allowed us to understand the quantum mechanical nature of roaming reactions. We expect these characteristics to be present in all roaming reactions," she says.

The results of this study will provide theoreticians with the data needed to hone their theories, which in turn will allow scientists to accurately predict the outcomes of sunlight-initiated reactions in the atmosphere.

Prof Kable says the study could also benefit scientists working in the areas of combustion and astrophysics, who use complex models to describe how molecules interact with each other in gaseous form.

A study led by researchers at Florida Atlantic University's Harbor Branch Oceanographic Institute examined toxins in tissue concentrations and pathology data from 83 stranded dolphins and whales along the southeastern coast of the United States from 2012 to 2018. Researchers examined 11 different animal species to test for 17 different substances in animals found on the shores in North Carolina and Florida.

This is the first study to date to publish a report examining concentrations in blubber tissues of stranded cetaceans of atrazine, an herbicide, DEP, (a phthalate ester found in plastics), NPE or nonylphenol ethoxylate commonly used in food packing, and triclosan, an antibacterial and antifungal agent present in some consumer products, including toothpaste, soaps, detergents and toys.

The study also is the first to report concentrations of toxicants in a white-beaked dolphin and in Gervais' beaked whales, species for which the scientific literature remains sparse. Documenting toxicants in cetaceans is a critical step in tracing chemical contaminants within the marine food web and understanding their effects on biological systems.

For the study, just published in the journal Frontiers in Marine Science, lead author Annie Page-Karjian, D.V.M., Ph.D., an assistant research professor and clinical veterinarian at FAU's Harbor Branch, and collaborators, analyzed blubber samples for five organic toxicants including atrazine, DEP, NPE, bisphenol-A, diethyl phthalates and triclosan. They also analyzed liver samples for five non-essential elements (arsenic, cadmium, lead, mercury, thallium), six essential elements (cobalt, copper, manganese, iron, selenium, zinc) and one toxicant mixture class (Aroclor, a highly toxic industrial compound).

Results of the study showed that toxin and element concentrations varied based on animal demographic factors including species, sex, age and location. Liver samples from bottlenose dolphins had significantly higher average concentrations of lead, manganese, mercury, selenium, thallium, and zinc, and lower average concentrations of NPE, arsenic, cadmium, cobalt, and iron than samples from pygmy sperm whales. In adult female bottlenose dolphins, average arsenic concentrations were significantly higher and iron concentrations were significantly lower than in adult males. Adult bottlenose dolphins had significantly higher average concentrations of lead, mercury, and selenium, and significantly lower average manganese concentrations compared to juveniles.

Geography also had an impact. Dolphins that stranded in Florida had significantly higher average concentrations of lead, mercury, and selenium, and lower concentrations of iron than dolphins that stranded in North Carolina.

Toxicants in the marine environment result from polluted runoff and chemicals in waterways from fossil fuels as well as single-use plastics commonly used by humans. These plastic objects include packaging film, detergents and some children's toys and contain dangerous phthalates.

"We must do our part to reduce the amount of toxicants that enter into our marine environment, which have important health and environmental implications not just for marine life but for humans," said Page-Karjian. "These chemicals work their way up through the food chain and get more concentrated the higher up they go. When dolphins and whales eat fish with concentrations of the chemicals, the toxic elements enter their bodies. Dolphins eat a variety of fish and shrimp in these marine environments and so do humans."

Drug overdoses are psychologically traumatic events that can lead to symptoms of post-traumatic stress disorder (PTSD), according to a study focused on female sex workers in Baltimore City that was led by researchers at the Johns Hopkins Bloomberg School of Public Health.

The study of 380 sex workers found that more than one-half reported symptoms of PTSD in the six months after experiencing or witnessing an overdose and after accounting for other traumas they may have experienced.

The findings, published online July 22 in the International Journal of Drug Policy, could help inform overdose treatment programs, which typically focus on reducing physical harms but largely avoid addressing psychological consequences.

Overdose is currently the leading cause of injury-related death in the U.S., exceeding vehicle crashes and firearms as the opioid crisis continues to grow. By itself the fatality statistic doesn't capture the full picture of the overdose crisis.

"For every overdose fatality, there are even more non-fatal overdoses," says Kristin Schneider, PhD, postdoctoral research fellow at the Bloomberg School and the paper's first author. "It's been unclear what mental health toll these events take on survivors and witnesses, particularly in the vulnerable and marginalized populations that overdose often affects. These findings suggest the consequences are not insignificant."

For the study, the authors used data from Enabling Mobilization, Empowerment, Risk Reduction, and Lasting Dignity (EMERALD), a long-running study of female sex workers in Baltimore City. As part of this study, the researchers recruited 380 female sex workers to answer questions on a tablet in a mobile van. These questions covered a variety of topics, including participants' demographic characteristics, sex work history, drug use, overdose experiences, mental health symptomology, police interactions, and drug- and sexual-risk behaviors. The study data cover responses from September 2017 to January 2019.

Study participants were asked if they had experienced an overdose themselves or witnessed a fatal or non-fatal overdose in the past six months. They also answered a 20-item questionnaire that evaluates PTSD symptoms in four separate domains outlined in the Diagnostic and Statistical Manual of Mental Disorders 5 (DMS-5): intrusion, which involves re-experiencing the event through unwanted memories, nightmare, or flashbacks; avoidance, which includes intentionally trying to avoid trauma-related thoughts, feelings, and external reminders; cognition/mood, which involves negative thoughts and feelings that were brought on or worsened by a trauma; and arousal/reactivity symptoms, which involve irritability, aggression, and hypervigilance.

Results showed that more than half of the participants had recently witnessed an overdose, with close to a third witnessing a fatal overdose and about half witnessing a non-fatal overdose. Close to a third of these volunteers had experienced a recent overdose themselves. More than half--199 participants--met the cutoff for a provisional diagnosis of PTSD using the criteria from the 20-item questionnaire. Most participants reported symptoms in each PTSD domain.

The authors found that even after accounting for other types of traumas experienced by this population--for example, two-thirds of these women had been homeless in the past six months, two-thirds had gone hungry at least once a week, 44% reported client violence, and 22% reported intimate partner violence--overdose trauma was still closely linked with PTSD symptoms. Although experiencing an overdose was associated with symptoms in all four domains, witnessing an overdose was associated with intrusive and arousal/reactivity domains.

"Existing measures for PTSD don't always accurately represent the effects of overdose traumas on populations that have high rates of cumulative trauma, like street-based female sex workers," says co-author Susan Sherman, PhD, MPH, professor in the Bloomberg School's Department of Health, Behavior and Society and principal investigator of the EMERALD study. "The traumas of witnessing and experiencing an overdose often add to a history of trauma, such that in addition to having an impact, overdoses can be triggering."

In addition, Sherman adds, the effects of some drugs--such as cocaine and other stimulants--can mimic the agitation of the arousal/reactivity domain.

The authors say that linking overdose trauma to PTSD could help guide new treatment paradigms for overdose that are focused on harm reduction--not just for those who experience overdose themselves, but for witnesses, who are increasingly becoming first responders in overdose events.

"Largely the treatment for overdose has been focused on saving lives. That's incredibly important, and it should be the first priority," Schneider says. "But in addition to physical harms, we should also be addressing the enormous psychological harms that accompany overdose to help people fully recover from the trauma in their lives."

PITTSBURGH (August 5, 2020) ... Developing catalysts for sustainable fuel and chemical production requires a kind of Goldilocks Effect - some catalysts are too ineffective while others are too uneconomical. Catalyst testing also takes a lot of time and resources. New breakthroughs in computational quantum chemistry, however, hold promise for discovering catalysts that are "just right" and thousands of times faster than standard approaches.

University of Pittsburgh Associate Professor John A. Keith and his lab group at the Swanson School of Engineering are using new quantum chemistry computing procedures to categorize hypothetical electrocatalysts that are "too slow" or "too expensive", far more thoroughly and quickly than was considered possible a few years ago. Keith is also the Richard King Mellon Faculty Fellow in Energy in the Swanson School's Department of Chemical and Petroleum Engineering.

The Keith Group's research compilation, "Computational Quantum Chemical Explorations of Chemical/Material Space for Efficient Electrocatalysts (DOI: 10.1149.2/2.F09202IF)," was featured this month in Interface, a quarterly magazine of The Electrochemical Society.

"For decades, catalyst development was the result of trial and error - years-long development and testing in the lab, giving us a basic understanding of how catalytic processes work. Today, computational modeling provides us with new insight into these reactions at the molecular level," Keith explained. "Most exciting however is computational quantum chemistry, which can simulate the structures and dynamics of many atoms at a time. Coupled with the growing field of machine learning, we can more quickly and precisely predict and simulate catalytic models."

In the article, Keith explained a three-pronged approach for predicting novel electrocatalysts: 1) analyzing hypothetical reaction paths; 2) predicting ideal electrochemical environments; and 3) high-throughput screening powered by alchemical perturbation density functional theory and machine learning. The article explains how these approaches can transform how engineers and scientists develop electrocatalysts needed for society.

"These emerging computational methods can allow researchers to be more than a thousand times as effective at discovering new systems compared to standard protocols," Keith said. "For centuries chemistry and materials science relied on traditional Edisonian models of laboratory exploration, which bring far more failures than successes and thus a lot of wasted time and resources. Traditional computational quantum chemistry has accelerated these efforts, but the newest methods supercharge them. This helps researchers better pinpoint the undiscovered catalysts society desperately needs for a sustainable future."

WASHINGTON, August 4, 2020 -- Tea drinkers have been saying it for years. Water heated in a microwave just isn't the same.

Typically, when a liquid is being warmed, the heating source -- a stove, for example -- heats the container from below. By a process called convection, as the liquid toward the bottom of the container warms up, it becomes less dense and moves to the top, allowing a cooler section of the liquid to contact the source. This ultimately results in a uniform temperature throughout the glass.

Inside a microwave, however, the electric field acting as the heating source exists everywhere. Because the entire glass itself is also warming up, the convection process does not occur, and the liquid at the top of the container ends up being much hotter than the liquid at the bottom.

A team of researchers from the University of Electronic Science & Technology of China studied this nonuniform heating behavior and presents a solution to this common problem in the journal AIP Advances, from AIP Publishing.

By designing a silver plating to go along the rim of a glass, the group was able to shield the effects of the microwave at the surface of the liquid. The silver acts as a guide for the waves, reducing the electric field at the top and effectively blocking the heating. This creates a convection process similar to traditional approaches, resulting in a more uniform temperature.

Placing silver in the microwave may seem like a dangerous idea, but similar metal structures with finely tuned geometry to avoid ignition have already been safely used for microwave steam pots and rice cookers.

"After carefully designing the metal structure at the appropriate size, the metal edge, which is prone to ignition, is located at weak field strength, where it can completely avoid ignition, so it is still safe," said Baoqing Zeng, one of the authors on the paper and professor of electronic science and engineering at UESTC.

Solids don't undergo convection, so getting your leftovers to warm up uniformly is a completely different challenge.

"For solids, there is no simple way to design a bowl or plate in order to achieve a much better heating result," Zeng said. "We can change the field distribution, but the change is very small, so the improvement is limited."

The group is considering other ways to improve nonuniformity in solid foods, but the methods are currently too expensive for practical use. For now, they're focusing their efforts on working with a microwave manufacturer to commercialize their microwave accessories for liquids.

A future in which tea can be microwaved without ridicule may not be too far away.

New insight on differences in the brains of men and women with autism has been published today in the open-access journal eLife.

The study suggests that autistic men, but not women, have enhanced neural excitability in specific brain regions that are important for social cognition and self-reflection, and this may differentially impact their ability to navigate social situations.

These findings support the idea that imbalances between excitation and inhibition in the brain affect some individuals with autism more than others. They also pave the way for further research to measure the imbalance of excitation and inhibition with non-invasive neuroimaging techniques. This could help scientists evaluate how different treatments may affect this aspect of the brain's biology.

The brain possesses its own natural balance between excitation and inhibition, but this balance differs among individuals. Higher levels of excitation are linked to the function of some autism-relevant genes that are found on the sex chromosomes, and can also be affected by hormones produced in higher quantities in men, such as testosterone. Differences in these sex-related mechanisms are important as autism affects males more than females.

"With this study, we wanted to gain a better understanding of how excitation-inhibition imbalance may affect autistic men differently to women," says one of the study's lead authors, Stavros Trakoshis, a graduate student at the Laboratory for Autism and Neurodevelopmental Disorders at the Istituto Italiano di Tecnologia (IIT) in Rovereto, Italy, and also based at the University of Cyprus.

To do this, Trakoshis and his colleagues started by using a computer model that simulates excitatory and inhibitory neurons as they interact and influence each other within the brain. The model allowed them to control the ratio of mixture between excitation and inhibition, simulated these interactions, and then reported neuronal population responses over time. The outputs are similar to data commonly measured with neuroimaging techniques, such as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI).

Trakoshis and the team observed that specific statistical attributes of the simulated data changed systematically with changes to the underlying excitation-inhibition ratios. These statistical changes were also validated using data from fMRI scans of brains in living mice that were given drugs to induce enhanced excitation.

After validating that non-invasive fMRI can reveal changes to the underlying cellular excitation-inhibition ratio, the team next applied their technique to fMRI data from adult men and women with autism. This revealed that autistic men, but not women, have atypically enhanced excitation in a brain region called the medial prefrontal cortex. The function of this brain region is typically associated with social cognition and self-reflection. The analysis also showed that, in women with autism, a more intact medial prefrontal cortex response (with less enhanced excitation, for example) was associated with better camouflaging of social difficulties in real-world social situations.

"Our work suggests that sex-related biological mechanisms could be integral for how excitation-inhibition balance develops in autistic men versus women," says senior author Michael Lombardo, Director of the Laboratory for Autism and Neurodevelopmental Disorders at the IIT. "This could help explain why we see phenomena such as camouflaging manifesting differently in autistic males versus females."

"Our approach could also be useful for understanding other neurodevelopmental conditions that affect males more than females, such as attention deficit-hyperactivity disorder," Lombardo concludes.

In efforts to automatically capture important data from scientific papers, computer scientists at the National Institute of Standards and Technology (NIST) have developed a method that can accurately detect small, geometric objects such as triangles within dense, low-quality plots contained in image data. Employing a neural network approach designed to detect patterns, the NIST model has many possible applications in modern life.

NIST's neural network model captured 97% of objects in a defined set of test images, locating the objects' centers to within a few pixels of manually selected locations.

"The purpose of the project was to recover the lost data in journal articles," NIST computer scientist Adele Peskin explained. "But the study of small, dense object detection has a lot of other applications. Object detection is used in a wide range of image analyses, self-driving cars, machine inspections, and so on, for which small, dense objects are particularly hard to locate and separate."

The researchers took the data from journal articles dating as far back as the early 1900s in a database of metallic properties at NIST's Thermodynamics Research Center (TRC). Often the results were presented only in graphical format, sometimes drawn by hand and degraded by scanning or photocopying. The researchers wanted to extract the locations of data points to recover the original, raw data for additional analysis. Until now such data have been extracted manually.

The images present data points with a variety of different markers, mainly circles, triangles, and squares, both filled and open, of varying size and clarity. Such geometrical markers are often used to label data in a scientific graph. Text, numbers and other symbols, which can falsely appear to be data points, were manually removed from a subset of the figures with graphics editing software before training the neural networks.

Accurately detecting and localizing the data markers was a challenge for several reasons. The markers are inconsistent in clarity and exact shape; they may be open or filled and are sometimes fuzzy or distorted. Some circles appear extremely circular, for example, whereas others do not have enough pixels to fully define their shape. In addition, many images contain very dense patches of overlapping circles, squares, and triangles.

The researchers sought to create a network model that identified plot points at least as accurately as manual detection--within 5 pixels of the actual location on a plot size of several thousand pixels per side.

As described in a new journal paper, NIST researchers adopted a network architecture originally developed by German researchers for analyzing biomedical images, called U-Net. First the image dimensions are contracted to reduce spatial information, and then layers of feature and context information are added to build up precise, high-resolution results.

To help train the network to classify marker shapes and locate their centers, the researchers experimented with four ways of marking the training data with masks, using different-sized center markings and outlines for each geometric object.

The researchers found that adding more information to the masks, such as thicker outlines, increased the accuracy of classifying object shapes but reduced the accuracy of pinpointing their locations on the plots. In the end, the researchers combined the best aspects of several models to get the best classification and smallest location errors. Altering the masks turned out to be the best way to improve network performance, more effective than other approaches such as small changes at the end of the network.

The network's best performance--an accuracy of 97% in locating object centers--was possible only for a subset of images in which plot points were originally represented by very clear circles, triangles, and squares. The performance is good enough for the TRC to use the neural network to recover data from plots in newer journal papers.

Although NIST researchers currently have no plans for follow-up studies, the neural network model "absolutely" could be applied to other image analysis problems, Peskin said.

A University of Houston College of Medicine researcher has found how a protein inside the body reduces the adverse effects of hypertonicity, an imbalance of water and solutes inside cells. Hypertonicity causes cell shrinkage and eventual cell death. The findings could have implications for a wide range of illnesses including edema from brain tumors, autoimmune diseases and kidney damage.

"We have found a mechanism for how the protein, called Nuclear Factor of Activated T cells 5 (NFAT 5), works to regulate tonicity particularly in response to hypertonicity," said Raj Kumar, clinical professor of biochemistry, UH College of Medicine. Kumar is reporting his findings in the journal Proceedings of the National Academy of Sciences of the United States of America. NFAT5 plays a crucial role protecting cells against harmful effects of stress in tissues, such as the kidneys, that experience large fluctuations in fluid volume. When NFAT5 is activated, it expresses protective osmolytes, small solutes that impact the balance of fluids and help maintain the integrity of cells. Kumar found that the work of osmolytes doesn't stop there. In a symbiotic process, they also may activate NFAT5.

"NFAT5 makes osmolytes and osmolytes act on NFAT 5 to give it structure so it can activate genes," said Kumar. The first 200 amino acids in the genetic sequence of NFAT5 are intrinsically ordered, unstructured with no defined shape. Kumar found that osmolytes increase the structure in the region and once structured, NFAT5 interacts with other proteins, some critical to maintain cellular function.

"Such protein-protein interactions are the natural function of any transcription factor. One of the proteins interacting with the structured NFAT5 is high mobility group protein (HMGI-C), which is known to suppress apoptosis or programed cell death," said Kumar.

Importance of water

If you've ever owned a plant, you know how important water is to its lifeblood. Not surprisingly, water plays the same role with humans, making up about 70% of cell mass. For all 70 trillion cells in the human body, each one needs the balance of water and solutes to carry out its mission, assuring the body, its organs and tissues, all work properly.

But that delicate balance is sometimes disturbed and, just as when water leeches out of plant cells causing the plant to die, when water leeches out of human cells, via osmosis, cell death begins as the cells start shrinking.

"Mammalian cells have adaptive responses that enhance survival during various forms of stress," said Kumar. "Cells adapt to hypertonic stress by accumulating organic osmolytes, which are known to compensate for the cell volume reduction induced by the hyperosmotic environment by allowing for the osmotic influx of water into cells."

The findings raise the possibility that increased intracellular ionic strength and elevated osmolytes caused by hypertonicity activate and stabilize NFAT5.