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In lab tests, Imperial researchers have created a metal-based molecule that inhibits the build-up of a peptide associated with Alzheimer's disease.

A peptide is a fragment of a protein, and one of the key hallmarks of Alzheimer's disease is the build-up of a specific peptide known as amyloid-β. The team demonstrated that with the aid of ultrasound, their molecule can cross the blood-brain barrier in mice, targeting the part of the brain where the damaging peptide most often accumulates.

Alzheimer's disease is the most common form of dementia, affecting approximately 50 million people worldwide. There is a pressing need to develop drugs that can prevent or reverse the effects of this devastating disease.

Some metal-based molecules have been previously designed to prevent amyloid-β from building up. However, these are often toxic to cells, or are unable to cross the blood-brain barrier (BBB) - a semi-permeable protective barrier that carefully regulates the passage of substances that enter and exit the brain.

Now, a team from the Departments of Chemistry and Bioengineering at Imperial College London have designed a metal-based molecule that is highly effective at preventing the build-up of amyloid-β in lab-based studies.

They also showed that the molecule is non-toxic to human brain-like cells, and that it can cross the blood-brain barrier in mice with the help of a technique using microbubbles and focused ultrasound. The results are reported in the journal Chemical Science.

First author Tiffany Chan, from the Departments of Chemistry and Bioengineering at Imperial, said: "Very few metal-based molecules have been investigated as potential inhibitors of amyloid-β build-up because of toxicity issues and difficulty crossing the blood brain barrier. The molecule we have designed is able to interfere with amyloid-β and seems non-toxic, and it can be delivered across the blood brain barrier using ultrasound, which means you don't need an invasive procedure."

The molecule is centred around the metal cobalt, surrounded by organic molecules that form a complex, which binds to amyloid-β peptides, preventing them from binding to each other and building up. The molecule also incorporates chemical groups that prevent it from being taken up into human nerve cells, reducing its toxicity.

To demonstrate the molecule could cross the BBB, the team used a technique that involves injecting the molecule alongside microbubbles into the veins of mice. When ultrasound is directed at the brain, the microbubbles rapidly move back and forth, opening the BBB and allowing the molecule to enter the brain in a non-invasive and targeted manner.

The team were able to focus the ultrasound on the hippocampal region of the brain, which is often strongly impacted by the build-up of amyloid-β in the early stages of Alzheimer's disease. They were also able to show how specific the ultrasound targeting can be by delivering the molecule only to the left hippocampus.

The molecule was shown to be well tolerated by the mice, who showed no ill effects after several weeks. Co-author Professor Ramon Vilar, from the Department of Chemistry at Imperial, said: "This study shows the potential that metal-based molecules have in preventing amyloid-β aggregation. The new compound will be studied in more depth to establish whether it can also prevent amyloid-β build-up in mice without having unwanted toxic side effects."

Americans tend to be far more consumed with national politics than with local politics. As places like Utah, Arizona, Michigan and Maryland gear up to hold local elections this summer and fall, history predicts that they will see an average of 29-37% fewer voters than they would were their elections held "on cycle," in tandem with state and federal elections.

This apparent indifference to local policies can have serious consequences, according to BYU research recently published in the American Political Science Review.

The study found that local governments formed in "off-cycle" years (like 2021) are less responsive to the majority's preferences and more responsive instead to organized interest groups, particularly when the interest groups' desires oppose those of the masses. This may occur, for example, where developers want more higher-density housing, more commercial development and fewer green spaces than citizens or in conservative locations, where public employees generally desire more spending on salaries than residents.

"When turnout for local elections is lower, that opens opportunities for groups that are organized to get their people out to vote and elect those who are going to push policy in a way that benefits the interest groups," said BYU political science professor Adam Dynes, a co-author of the paper. "So election timing ends up being pretty important."

Of the more than 25,000 municipalities in the U.S., about 75% hold their elections off cycle, including many large cities like Chicago. When local residents don't vote -- and in off-cycle elections, it's common for fewer than a quarter of eligible voters to participate -- they relinquish significant power, Dynes observed.

"Our focus is often on national politics, whether that's because national politics reach everyone, because we are socialized to focus on national politics in school or because partisanship is increasingly becoming an important part of people's identities," he said. "But in our daily lives, we are arguably affected the most by local policies, which shape our water access, our streetlights, our K-12 schools, events like Fourth of July celebrations. Local politics influence what your neighborhood is like and your quality of life."

To determine whether local governments are more responsive to the masses or to interest groups, Dynes and his co-authors concentrated especially on policies regarding public employees, who reliably organize together regardless of a city's political leanings.

Examining expenditures on public employee salaries in 1,600 large cities from the 2012 U.S. Census Bureau, the authors reasoned that more conservative cities would spend less on public employees because conservatives favor smaller government. That assumption was borne out in the data -- but it was mostly driven by conservative places that held on-cycle elections. Conservative municipalities with off-cycle elections spent almost double per capita on public employee salaries compared to those with on-cycle elections, the same amount as more liberal-leaning places, suggesting the influence of public employee interest groups.

The study's findings inform the ongoing debate about the ideal timing of municipal elections. "If the goal is to have election outcomes reflect the preferences of your median voter," Dynes said, "then you may want to align local elections with state and national elections."

But even if most municipal elections never move to on-cycle years, Americans can still help ensure that their local governments are responsive to what matters to them.

"Find out when elections are in your city, show up to public hearings, sign up for email newsletters from local politicians and get involved," Dynes advised. "Local politics is the level of government where your individual actions can have the greatest influence."

A team of University of Houston pharmaceutical researchers is reporting a newly recognized process of drug metabolism in the intestines - followed by recycling through the liver - that could have important implications for developing treatments for intestinal diseases and for taking multiple medications at the same time.

"The intestines play a crucial role in metabolizing and recycling certain plant compounds and drugs," reports Ming Hu, Diana S-L. Chow Endowed Professor of Drug Discovery and Development and the senior author of the paper in eLife. "The discovery has important implications for scientists trying to understand how both phytochemicals (a type of plant compound, such as flavonoids) and medicines are metabolized in the body."

The new information could help chemists develop better drugs and clinicians to fine-tune medication dosing, especially when dealing with polypharmacy, where a patient takes multiple drugs at the same time.

Scientists have long recognized that bile acid is produced in the liver and released into the intestines and is then recycled back through the liver for reuse as the bile. Some medications that are metabolized in the liver also go through this process, known as enterohepatic recycling (EHR). This can extend the life of drugs in the body, which may affect how well they work and whether they cause side effects.

"The liver has long been considered the most important organ for drug metabolism," said lead author Yifan Tu, who conducted the study while he was doing his doctoral work at the UH College of Pharmacy. "But we've shown that the intestines also play a major role in drug metabolism."

In their experiments, the team administered 16 different types of flavonoids or drugs directly to the liver or intestines and then tracked what happened to the treatments. They found that some drugs and compounds were metabolized in the intestines and the metabolites were then transported to the liver before being cycled back into the intestines.

"In this process, the liver acts only as a recycling organ, which is rare, since the liver is known to be the metabolic 'superstar' organ in humans," said Tu, who is now a postdoctoral fellow at the pharmaceutical company Boehringer Ingelheim in Connecticut.

The team has called this new mechanism 'hepatic enteric recycling' (HER). They found that, in this process, the roles of the liver and intestines are reversed. "This may explain why some drugs or plant compounds have larger effects on the intestine than anticipated and could help scientists understand how intestinal diseases may alter drug metabolism in the body," said Tu.

"We hope our findings will be useful for medicinal chemists to design new drugs tailored to treat intestinal, especially colonic diseases," said Hu.

Firefighters battling wildfires in the western United States use a variety of suppression tactics to get the flames under control. Prescribed burns, or controlled fires intentionally set to clear shrubs and forest litter before a wildfire ever ignites, can make fire suppression operations almost three times as effective in limiting wildfire severity, according to a new study by researchers from Penn State, the U.S. National Park Service and the U.S. Forest Service.

"A lot happens once a fire starts burning," said Lucas Harris, a postdoctoral scholar in geography at Penn State. "Crews on the ground remove vegetation and construct fire lines, and planes and helicopters drop flame retardant to stop the spread of the fire. In this study, we measured the effectiveness of suppression operations and previous prescribed fires on fire severity, which is something that really hasn't been done before."

The researchers measured tree mortality in Lassen Volcanic National Park, California, one year after the 2012 Reading Fire burned more than 28,000 acres in the park and nearby communities. They combined this data with data on fuels, vegetation and previous prescribed fires, and they worked with fire managers to reconstruct the suppression operations that took place during the fire.

The researchers classified the fire suppression operations as being of low, moderate or high intensity and ran computer simulations to determine tree mortality rates in the forest with and without operations. They ran similar computer models to measure the impact of prescribed burns. They report their findings in the International Journal of Wildland Fire.

The scientists found that in areas with moderate to high operations intensity, suppression operations reduced tree mortality by 22%. Also, prescribed fires reduced tree mortality by 32%. The combination of prescribed fires and suppression operations, however, reduced tree mortality by 72%.

"We know that prescribed fires reduce the potential for the next fire in areas where they're used, and firefighters know them (these areas) as places where fire activity will be reduced and can use those areas as anchors to try to catch wildfires before they spread," said Alan Taylor, professor of geography and ecology and associate in the Earth and Environmental Systems Institute at Penn State. "Prior to this study, no one looked at the combined effectiveness of fire suppression operations and prescribed fires and quantified how important this interaction is in terms of fire severity. Those operations wouldn't have been as successful without the prescribed burns."

The study results show that prescribed fires have a strong moderating effect and help to provide good anchor points for operations during a wildfire, Harris added.

Harris and Taylor attributed the success of the study to Taylor's long-standing working relationships with local and federal partners in the area, especially with fire managers from the U.S. National Park Service and the U.S. Forest Service. They hope to continue working with these partners to conduct similar studies in other areas of California and the American West.

"This research demonstrates that the strategy of using prescribed fire to reduce potential fire activity and to facilitate fire suppression strategies works," said Taylor. "Fire managers have known that prescribed fire works, but they haven't been able to say how well it works. Here we're saying that it works really well."

A team of researchers, affiliated with UNIST has succeeded in developing a new optical microscope technology, capable of deeper imaging beyond the biological tissues. This breakthrough has been led by Professor Jung-Hoon Park and his research team in the Department of Biomedical Engineering at UNIST.

Optical imaging technology has emerged as an essential research tool for biomedical studies due to its high resolution and good tomography capability. However, the limited penetration depth of the optical microscope makes it difficult to observe biological tissues of more than 100 μm thickness. This is because strong light scattering, caused by various components of biological tissues, notably lipids and proteins, makes the subject out of focus, which then causes image blurring.

In this study, the research team showed that for wavefront shaping in thin anisotropic scattering media, such as biological tissues, they can optimize the wavefront shaping quality by simply limiting the numerical aperture (NA) of the incident wavefront.

In addition, using the same number of controlled modes, and therefore the same wavefront measurement time, the research team demonstrated that the wavefront shaped focus peak to background ratio can be increased by a factor of 2.1 while the energy delivery throughput can be increased by a factor of 8.9 through 710 μm thick brain tissue by just limiting the incident NA.

The research team anticipates that the new approach can open new avenues in a variety of biomedical applications where energy delivery enhancement or high-resolution imaging/photostimulation is required in a limited decorrelation time window or in light-starved environments.

A new study reveals the strategies that stop bandits from illegally fishing in Australian waters--but warns there is a cost to the region's poorer countries.

Co-author Dr Brock Bergseth, from the ARC Centre of Excellence for Coral Reef Studies at James Cook University, said poachers are simply following the recurring history of human fishing: intensively fish and devastate local resources, then move further afield to--in these cases--fish illegally or poach in other countries' waters.

"Millions of people rely on fish and seafood and when offered no alternative choice, will chose banditry and illegal fishing to get by," Dr Bergseth said.

"But without a regional strategy and investments for rebuilding and managing countries' fisheries, this just becomes one big game of whack-a-mole: you deal with the problem in one area, only for it to pop up in another," he said.

The study shows how Vietnamese poaching boats, or 'blue boats', encroached into Australian waters between 2013 and 2017.

Under a jointly signed Memorandum of Understanding (MOU) in 2017, the Australian Fisheries Management Authority and the Vietnamese Ministry for Agriculture and Rural Development designed and delivered a series of workshop interventions to deter illegal fishing by Vietnamese fishers in Australia between 2017 and 2018.

Both before and after the workshops, 82 fishers were surveyed to understand why they were coming to Australia and also whether the workshop's explanations of the penalties were effective in shifting perceptions related to reducing illegal fishing.

"The main reason these fishers engaged in banditry was their displacement from their traditional fishing grounds in the South China Sea," Dr Bergseth said. "This is just one of the implications of an expanding Chinese territory, and it affects countries as far away as Australia."

Lead author Dr Chris Wilcox, from Australia's national science agency CSIRO, said since the workshops, there hasn't been a single sighting of a Vietnamese fishing boat illegally fishing in Australian or Pacific waters.

But, he cautions, while an understanding of the penalties might deter fishers from poaching in Australian waters, they also lose their access to economically viable fish resources.

Captains and their crews opt to fish in other locations, legal or not, even in the face of penalties for doing so.

"Australia can build a wall of steel with patrol boats and surveillance aeroplanes to protect our waters--but without improvements in fish stocks in their legal fishing grounds, Vietnamese vessels will be under pressure to leave in pursuit of revenue. This is creating ongoing issues for our regional neighbours," Dr Wilcox said.

Reports continue to surface of Vietnamese fishers captured in other regional countries including Thailand, Malaysia, Indonesia, the Philippines and Vanuatu.

Dr Wilcox said regional action on the root causes of the problem can solve the issue for everyone. And though this is a long-term project, it also has the best potential for the highest long-term return on investment in terms of reducing illegal fishing.

"Incursions will continue as long as the number of fishing vessels across the region exceeds what the resources can support," Dr Wilcox said. "While it is essential to keep the enforcement pressure on, this is where coordination across the region could have a positive effect."

However, he also said tension amongst South East Asian countries over sea borders and other issues still precludes effective coordinated action on illegal fishing.

"Addressing the state of resources in the waters of countries across the region and their ability to collaborate to address vessels illegally crossing borders to fish are the two key ingredients for solving this problem," Dr Wilcox said.

Dr Bergseth said otherwise, things will only get worse as ocean resources dwindle.

"The decisions we make in the next 5-10 years could well chart the state of our oceans for the next 100," he said.

What the fruit fly is to zoologists, the thale cress is to botanists. The widespread herb with the botanical name Arabidopsis thaliana serves them as a model organism from which knowledge can be gained for other plants. It is therefore extremely well researched - also genetically. For example, it is now known that the genetic material of Arabidopsis thaliana (its genome) comprises around 125 million base pairs. It's like having a Lego manual in front of you that is 125 million letters long and contains everything you need to know to build an Arabidopsis plant.

Similar to humans, different Arabidopsis specimens are generally not genetically identical. If you were to compare the construction manual of all plants of this species, you would encounter differences in about 10 million places, experts estimate. "We have now taken a closer look at three million of these variable sites in the genome," explains Arthur Korte, junior professor of Evolutionary Genomics at the University of Würzburg. "And we did so in nearly 900 Arabidopsis plants from very different locations across Europe, from southern Spain to central Sweden."

For botanists, the variations in the genome are very interesting. because they are responsible for differences between individual Arabidopsis plants. Some plants can, for example, cope better with drought, while others are more resistant to frost. "To some extent, these are traits that we would like to introduce into our crop plants," Korte explains. "But to do that, we first need to know which genetic differences are related to which traits in the plant."

Too much heterogeneity is harmful

Classically, scientists use a method known by the abbreviation "GWAS" (genome-wide association study) for this purpose. They examine the genomes of thousands of plants and look for changes in the genetic blueprint that are particularly frequently associated with certain traits, such as better drought resistance. The more specimens one compares in this way, the more such links between genotype (the individual genetic blueprint) and phenotype (the properties of the plant in question) should stand out.

"But we were able to show in our study that this is not necessarily the case," Korte emphasizes. "Instead, it's sometimes better to limit yourself to fewer specimens from a defined local area." The reason: plant populations that grow in locations with very different conditions often differ significantly in their genomes. This heterogeneity might lead to the scenario that a trait such as drought resistance has very different genetic origins in different locations. "Therefore, if a GWAS includes many plants with very high genetic heterogeneity, it may miss important associations between genotype and phenotype," Korte says.

In their study, the scientists were indeed able to demonstrate this effect. On the one hand, they conducted a GWAS of all nearly 900 plants. In addition, they also examined only subpopulations - for example, those Arabidopsis specimens that had been collected on the southern Iberian Peninsula. "In doing so, we found genetic correlations that were not seen in the overall population because they had become too diluted there," says Korte. "These results show that valuable new insights can be gained from smaller, more genetically homogeneous samples." That applies not only to plants, by the way, but just as much to GWAS in humans.

Local adaptations are often based on changes in gene networks

The study also provides interesting insights into the evolution of new traits: genetic adaptations to local conditions (for example, to a particularly dry environment) are usually not based on the fact that a single "drought gene" has changed and thus become more effective. Instead, they often involve regulator genes, which in turn intervene entire networks of traits. "These regulators could then provide a better fine-tuning of already existing metabolic pathways," says Korte.

This finding is also relevant for breeding new varieties. In the past, it was often thought that one simply had to cross a certain gene into a breeding line in order to obtain the desired trait there. In the meantime, however, it has become increasingly clear that networks of many different factor have to be considered. "We are now learning better and better how to identify such networks," says Korte. "With this knowledge, it might be possible in the future to adapt today's crops to new challenges such as climate change. "

Kamil Gareev, Associate Professor at ETU "LETI," justified the prospects of using magnetotactic bacteria to treat malignant tumors.

LETI researchers identified the main properties of magnetotactic bacteria and described the possibilities of their application in medicine. The results obtained will help create theranostic agents in neurooncology and cardioprotection. The results of the joint study with colleagues from St. Petersburg State University, RAS Institute of Cytology, and RAS Institute of Biotechnology were published as an overview article in the journal Magnetochemistry.

Magnetotactic bacteria (MTB) are distinguished by their ability to synthesize magnetosomes, special cellular organelles in which magnetite biomineralization occurs. Thanks to their magnetic properties, MTBs and isolated magnetosomes can be used in medicine to fight cancer. Using magnetosomes, drugs will be transported directly to the malignant tumor. In addition, scientists aim to study the formation of bacterial magnetite crystals inside MTB cells, the mechanisms of magnetostatic interaction between individual magnetosomes, and their chemical and aggregative stability outside the bacterial cells. These results will become the core of research in paleomagnetism and the physics of magnetic phenomena.

Currently, scientists from Germany, France, Brazil, the USA, and Japan are engaged in large-scale research of magnetotactic bacteria. The research of LETI scientists will be the first in St. Petersburg. LETI chose an interdisciplinary approach: the university formed a research team, which includes specialists in different fields - physics of magnetic phenomena, rock magnetism and magnetofossils, neurooncology, and target therapy based on nanoparticles, as well as the synthesis of composite magnetic particles based on iron oxide. That will make it possible to carry out a versatile study and obtain objective results.

"We expect to eventually complete the full cycle of research - from fermentation of MTBs in high throughput automated bioreactors of large volume and evaluation of their physical characteristics to functionalization of magnetosomes with pharmaceuticals and their laboratory tests. Thus, subject to the achievement of the set goals, for the first time in our city, there will be world-class results in this field of science." - Kamil Gareev, Associate Professor of the Department of Micro- and Nanoelectronics of LETI, Senior Researcher of the Engineering Center for Microtechnology and Diagnostics

The next stage of studying MTBs will bring scientists closer to the practical use of structures based on bacterial magnetosomes in medicine as new tools for targeted drug delivery, hyperthermia therapy, and contrast agents for magnetic resonance imaging. "Compared to currently used structures based on synthetic iron oxide nanoparticles, bacterial magnetite has better chemical stability, high uniformity in shape and size, and, even more importantly, high biocompatibility," commented Kamil Gareev.

LETI scientists obtained the first results of studying magnetic nanoparticles in 2013, and since then, research in this direction has continued. Until 2021, the research mainly focused on the properties of synthetic, rather than biogenic, magnetic nanoparticles, such as magnetosomes. The long-term experience allowed researchers to move on to a full-fledged study of magnetotactic bacteria and bacterial magnetosomes.

Autistic people need extra help in going green say researchers behind a new study which argues for a more inclusive environmental agenda.

Climate action movements are gathering extraordinary pace due to international campaigners like Greta Thunberg, whose autism has been well documented. Being autistic has been used to explain and celebrate, but also diminish and denigrate, her activism.

Thunberg, for example, reports that being autistic is a psychological "gift" and "superpower" that underpins her environmental attitudes and behaviours. This has fuelled speculation - in the media and the general public - that autistic personality traits are intrinsically linked to environmentalism. But, until now, there was no investigation to test the autistic aspect of the so-called 'Greta Thunberg Effect'.

Now a new study from the universities of Bath, Cardiff, Essex, and King's College London, in the Journal of Environmental Psychology, suggests that autistic personality traits are unrelated to environmental attitudes. In contrast they can be linked to lower engagement in pro-environmental green behaviours.

Reflecting on their findings based on data from over 2,000 people in the UK and US, they discuss several reasons why people with autistic traits might face challenges going green. This includes sensory challenges that can act as a barrier to using noisy and crowded public transport, as well as issues over changing diet to reduce meat consumption.

The researchers conclude that autism spectrum conditions can present obstacles for pro-environmental action and are calling for greater support for people with autism and mental health conditions as well as more research on the topic.

Practical support might include adapting cognitive behavioural therapy, which is commonly used to facilitate behaviour change in people with mental health conditions, to support pro-environmental behaviours. They suggest it is also important to consider early environmental education for families and teachers supporting children with neurodevelopmental and metal health conditions.

Dr Punit Shah, Associate Professor of Psychology at the University of Bath and the GW4 Neurodevelopmental Neurodiversity Network, explained: "The 'Greta Thunberg Effect' has powerfully emerged in recent years, with many focussing on her autism diagnosis to explain her environmental activism.

"Intuitively, the speculation between autism and environmentalism has resonated with the public, including autistic adults who helped co-produce our new research. We also know from research that interests in animals, nature, and the environment, are widely reported by autistic individuals, which enhances their subjective wellbeing and life satisfaction.

"However, our findings show the link between autism and environmentalism is not clear cut. Given our results, we strongly recommend a move away from 'Thunberg-driven' autism-based narratives, whether positive or negative, of recent advances in climate policy.

Emily Taylor, lead author of the article said: "Our research is some of the first on how neurodevelopmental or mental health conditions may influence environmental attitudes and behaviour, and climate change beliefs. We focussed on autistic traits, but many other psychological differences and difficulties are likely to be associated with barriers to personal action on climate change. For instance, those with anxiety, or high levels of stress more generally, may be unable to move towards pro-environmental behaviours, for example using public transport, and have difficulty sustaining any changes they make.

"We need to think harder about supporting people to manage stress and mental health difficulties, which might then give them the cognitive resources to direct towards engaging in green behaviours. Mental health and environmental science are often thought about separately, but greater coherence - in terms of research and policy - will be crucial for both people's mental wellbeing and the environment."

Dr Shah added: "The United Nations recently called for a 'disability-inclusive' approach to climate action. Although there is some understanding of how 'physical' health impairments are linked to difficulties with engagement in environmental behaviours, there is little understanding of how 'mental' health problems or 'hidden disabilities' may have the same effect.

"Based on our findings, we speculate that the psychological and financial support required for autistic people and people with other mental health conditions to engage in pro-environmental activities is underestimated and must be a focus in the future - for a fairer, more inclusive environmental agenda."

RESEARCH TRIANGLE PARK, N.C. -- Army-funded research identified a new chemistry approach that could remove micropollutants from the environment.

Micropollutants are biological or chemical contaminants that make their way into ground and surface waters in trace quantities.

Using a pioneering imaging technique, Cornell University researchers obtained a high-resolution snapshot of how ligands, molecules that bind to other molecules or metals, interact with the surface of nanoparticles. In doing so, they made an unexpected breakthrough discovery. They determined that by varying the concentration of an individual ligand they could control the shape of the particle it attached too.

This approach could result in an array of daily applications, including developing chemical sensors that are sensitive at a very low level to a specific chemical in the environment.

"Professor Peng Chen's work allows for deep insights into molecular adsorption processes, which is important to understand for designing molecular sensors, catalysts, and schemes to clean up micro-pollutants in the environment," said Dr. James Parker, program manager, U.S. Army Combat Capabilities Development Command, known as DEVCOM, Army Research Laboratory. "This research is also important for designing and engineering stimuli-responsive materials with specialized function that could not be found in regular, bulk materials."

The research, published in Nature Communications, studied interactions of ligands and gained new understanding of the strength, or affinity of ligand adsorption as well as how multiple ligands cooperate, or don't, with each other.

"When the molecule adsorbs on the surface of a nanoscale material, it also actually protects the surface and makes it more stable," said Dr. Peng Chen, the Peter J.W. Debye Professor of Chemistry in the College of Arts and Sciences at Cornell University, who led the research. "This can be utilized to control how nanoscale particles grow and become their eventual shape. And we found we can do this with just one ligand. You don't do any other trick. You just decrease the concentration or increase the concentration, and you can change the shape."

Understanding how ligands interact with the surface of nanoparticles has been a challenge to study. Adsorbed ligands are difficult to identify because there are other molecules in the mix, and nanoparticle surfaces are uneven and multifaceted, which means they require incredibly high spatial resolution to be scrutinized.

A nanoparticle's size and surface structures, or facets, are intrinsically tied to the particle's potential applications. The larger the particle, the more atoms fit inside it, while smaller particles have less available space internally but a greater surface volume ratio for atoms to sit atop, where they can be utilized for processes such as catalysis and adsorption. The different types of structures the atoms and molecules form on these surface facets are directly correlated with the particle's shape.

Army-funded research identifies a new chemistry approach that could remove micropollutants from the environment.

Scientists have used several imaging methods to survey these particles, but until now, they haven't been able to obtain nanometer resolution to really explore the nooks and crannies of the multiple surface facets and quantify the affinity, or strength, of a ligand's adsorption. The research team was able to do just that by employing a method of their own devising called COMPetition Enabled Imaging Technique with Super-Resolution or COMPEITS.

The process works by introducing a molecule that reacts with the particle surface and generates a fluorescent reaction. A nonfluorescent molecule is then sent to bind to the surface, where its reaction competes with the fluorescent signal. The resulting decrease in fluorescence, essentially creating a negative image, can then be measured and mapped with super high resolution.

Using COMPEITS on a gold nanoparticle, the team was able to quantify the strength of ligand adsorption, and they discovered ligand behavior can be very diverse. Ligands, it turns out, are fair-weather friends of a sort, at some sites they cooperate to help each other adsorb, but at other sites they can impair each other's efforts. The researchers also discovered that sometimes this positive and negative cooperativity exists at the same site.

In addition, the researchers learned that the surface density of adsorbed ligands can determine which facet is dominant. This crossover inspired the team to vary the concentrations of individual ligands as a way to tune the shape of the particle itself.

"For us, this has opened more possibilities," Chen said. "For example, one way to remove micropollutants, such as pesticides, from the environment is to adsorb micro-portions on the surface of some adsorbent particle. After it is adsorbed on the surface of the particle, if the particle is a catalyst, it can catalyze the destruction of the micropollutants."

Antimicrobials are used to kill or slow the growth of bacteria, viruses and other microorganisms. They can be in the form of antibiotics, used to treat bodily infections, or as an additive or coating on commercial products used to keep germs at bay. These life-saving tools are essential to preventing and treating infections in humans, animals and plants, but they also pose a global threat to public health when microorganisms develop resistance to them, a concept known as antimicrobial resistance.

One of the main drivers of antimicrobial resistance is the misuse and overuse of antimicrobial agents, which includes silver nanoparticles, an advanced material with well-documented antimicrobial properties. It is increasingly used in commercial products that boast enhanced germ-killing performance - it has been woven into textiles, coated onto toothbrushes, and even mixed into cosmetics as a preservative.

The Gilbertson Group at the University of Pittsburgh Swanson School of Engineering used laboratory strains of E.coli to better understand bacterial resistance to silver nanoparticles and attempt to get ahead of the potential misuse of this material. The team recently published their results in Nature Nanotechnology.

"Bacterial resistance to silver nanoparticles is understudied, so our group looked at the mechanisms behind this event," said Lisa Stabryla, lead author on the paper and a recent civil and environmental PhD graduate at Pitt. "This is a promising innovation to add to our arsenal of antimicrobials, but we need to consciously study it and perhaps regulate its use to avoid decreased efficacy like we've seen with some common antibiotics."

Stabryla exposed E.coli to 20 consecutive days of silver nanoparticles and monitored bacterial growth over time. Nanoparticles are roughly 50 times smaller than a bacterium.

"In the beginning, bacteria could only survive at low concentrations of silver nanoparticles, but as the experiment continued, we found that they could survive at higher doses," Stabryla noted. "Interestingly, we found that bacteria developed resistance to the silver nanoparticles but not their released silver ions alone."

The group sequenced the genome of the E.coli that had been exposed to silver nanoparticles and found a mutation in a gene that corresponds to an efflux pump that pushes heavy metal ions out of the cell.

"It is possible that some form of silver is getting into the cell, and when it arrives, the cell mutates to quickly pump it out," she added. "More work is needed to determine if researchers can perhaps overcome this mechanism of resistance through particle design."

The group then studied two different types of E.coli: a hyper-motile strain that swims through its environment more quickly than normally motile bacteria and a non-motile strain that does not have physical means for moving around. They found that only the hyper-motile strain developed resistance.

"This finding could suggest that silver nanoparticles may be a good option to target certain types of bacteria, particularly non-motile strains," Stabryla said.

In the end, bacteria will still find a way to evolve and evade antimicrobials. The hope is that an understanding of the mechanisms that lead to this evolution and a mindful use of new antimicrobials will lessen the impact of antimicrobial resistance.

"We are the first to look at bacterial motility effects on the ability to develop resistance to silver nanoparticles," said Leanne Gilbertson, assistant professor of civil and environmental engineering at Pitt. "The observed difference is really interesting and merits further investigation to understand it and how to link the genetic response - the efflux pump regulation - to the bacteria's ability to move in the system.

"The results are promising for being able to tune particle properties for a desired response, such as high efficacy while avoiding resistance."

To extract the polarization information of incident light, polarization-sensitive photodetectors (PSPDs) exhibit significant practical application in both military and civil areas, like bio-imaging, remote sensing, night vision, and helmet-mounted sight for fighter plane. Optical filters combined with polarizers are usually needed for traditional photodetectors to realize polarized light detection. But it will increase the size and complexity of devices. To obtain a small-size PSPD, one-dimensional (1D) nanomaterials with geometrical anisotropy, such as nanowires, nanoribbons, and nanotubes, have been used as the sensitive materials for PSPDs, which can directly identify the polarization information of incident light without any optical filters and polarizers. However, it is not an easy task for patterning and integrating these 1D nanochannels for mass production of PSPDs.

Atomically layered two-dimensional (2D) semiconductors with low crystal symmetry show great potential in micro-nano PSPDs recently due to their intrinsically in-plane anisotropic properties. For example, SnS, ReS2, GeS2, GeAs2, AsP and black phosphorus (BP) exhibit an obvious in-plane anisotropy behavior in carrier transport, thermal conductivity, electrical conductivity, thermoelectric transport and optical absorption processes. They have potential applications in polarization sensitive photodetectors, polarization ultrafast lasers, polarization field effect transistors and polarization sensors. Among them, BP-based PSPDs have the highest photocurrent anisotropy ratio of 0.59, benefitting from its high carrier mobility and the strong in-plane anisotropy coming from the low-symmetry puckered honeycomb crystal structure. But BP-based optoelectronic devices are hard to get rid of the ambient degradation problem. 2D layered indium selenide (InSe), which also has high carrier mobility and is more stable than BP in atmospheric environment, exhibit huge potential application in high performance optoelectronic and electronic devices. In addition, the anisotropic optical and electronic properties of 2D layered InSe have already been demonstrated in 2019. Worth noting that InSe crystal has three specific polytypes, which are in β, γ, and ε phases, respectively. Among them, InSe in γ-phase and ε-phase belong to symmetry groups. Only the InSe in β-phase (β-InSe) belongs to the nonsymmetry point group, indicating that β-InSe exhibits better anisotropic optoelectronic properties than the other two polytypes.

In order to achieve high performance PSPDs with good stability, the advanced optoelectronic devices research team led by Professor Han Zhang from the Shenzhen University prepare the stable p-type 2D layered β-InSe via temperature gradient method. The anisotropic nature of the β-InSe has been revealed by angle-resolved Raman. The intensity of the out-of-plane and in-plane vibrational modes exhibit pronounced periodic variations with the polarization angle of the excitations. Besides, a good stability of β-InSe flakes and their FET devices has been proved by long-time AFM measurement and multi-repeat electrical performance test. The experimental results (a-b) are in good agreement with the theoretical calculations (c-d) that there are strong anisotropic transport and polarization-sensitive photoresponse in 2D layered β-InSe flakes. The photocurrent anisotropic ratio of the β-InSe photodetector reaches 0.70, which is ranking high among the single 2D material based PSPDs. The strong anisotropic Raman, transport and photoresponse properties of the β-InSe enable its great application potential in filter-free polarization sensitive photodetectors.

New research from the University of Georgia finds that older Mexican Americans who live in low English-speaking neighborhoods are at greater risk for poor health and even an early death.

Language barriers can be a significant deterrent to health. People who don't speak English well are less likely to seek health care or receive health information. This can lead to delay of care and missed health screenings for chronic disease and cancers. Language isolation is also linked to poor mental health.

These issues only compound as non-English speakers age, said study co-author Kerstin Emerson, a clinical associate professor of gerontology at the Institute of Gerontology in UGA's College of Public Health.

"Not many studies have looked at the link between language isolation and health outcomes for Hispanic older adults," said Emerson, and few have studied how a whole neighborhood that is linguistically isolated - where more than a third of households do not speak English or speak it proficiently - may impact health.

Understanding risk at the community level is vital for creating effective public health interventions, which focus on improving health in populations, said Emerson.

Older Mexican Americans tend to have lower English-speaking proficiency than other Latino groups, and increasingly, this group is experiencing poorer health outcomes.

"So, we are trying to explain one factor - living in this community with a lot of linguistically isolated households and whether it would matter a lot to their health, and even survival during old age," said co-author Donglan "Stacy" Zhang, assistant professor of health policy and management at UGA CPH.

The team analyzed data from the Hispanic Established Populations for the Epidemiologic Studies of the Elderly dataset, a survey of over 1,100 Mexican Americans, 65 and older, living in five U.S. states. The survey followed respondents up to 13 years, tracking demographic factors and personal health factors.

"We controlled for individual level factors, like their smoking status and alcohol use, because these behavior issues contribute to all-cause mortality, and we also adjusted for community-level factors. Community poverty rates, for example, are highly correlated with all-cause mortality, but living in a linguistically isolated community still significantly predicts all-cause mortality," said Zhang, who led data analysis for the study.

In fact, older Mexican Americans who lived in linguistically isolated neighborhoods had mortality rates that were about 1.25 times higher.

"If you are linguistically isolated, you're very likely to be isolated socially, and we know social isolation contributes to mortality," said Emerson. Her research on social isolation among older adults has found that social connection is essential to accessing and maintaining good health.

"It's not just that you're not using the health care system; you're very likely not to have a large social network outside of your neighborhood. The bigger your social networks are, the more likely you are to find out about services," she said.

Zhang recommends that health care providers need to be trained to provide culturally adaptive services to non-English speaking community members, and more outreach should be done to bring preventive services like chronic disease screenings to the patients who need it.

Emerson agrees.

"We focus on the easy thing, which is translating a pamphlet [into Spanish], but we're actually talking about entire neighborhoods that are socially isolated, so not just the one home or one person. Translating pamphlets isn't going to cut it," she said.

Reducing health disparities, says Zhang, will require tackling a wider set of issues like language barriers. Zhang and Emerson say that more long-term, population studies like this one are needed to support better public health outreach.

"It would mean targeting those communities with specific interventions that are linguistically and culturally appropriate. So, let's spend our money there and do it culturally, competently," said Emerson.

Children exposed to elevated levels of air pollution may be more likely to have poor inhibitory control during late childhood and poor academic skills in early adolescence, including spelling, reading comprehension, and math skills. Difficulty with inhibition in late childhood was found to be a precursor to later air pollution-related academic problems. Interventions that target inhibitory control might improve outcomes.

Results of the study by researchers at the Columbia Center for Children's Environmental Health (CCCEH) at Columbia University Mailman School of Public Health and Columbia University Irving Medical Center are published in the journal Environmental Research.

"Children with poor inhibitory control are less able to override a common response in favor of a more unusual one--such as the natural response to say 'up' when an arrow is facing up or 'go' when a light is green--and instead say 'down' or 'stop,'" says first author Amy Margolis, PhD, associate professor of medical psychology in the Department of Psychiatry at Columbia University Irving Medical Center. "By compromising childhood inhibitory control, prenatal exposure to air pollution may alter the foundation upon which later academic skills are built."

"When evaluating student's learning problems and formulating treatment plans, parents and teachers should consider that academic problems related to environmental exposures may require intervention focused on inhibitory control problems, rather than on content-related skill deficits, as is typical in interventions designed to address learning disabilities," Margolis adds.

"This study adds to a growing body of literature showing the deleterious health effects of prenatal exposure to air pollution on child health outcomes, including academic achievement," says co-author Julie Herbstman, PhD, CCCEH director and associate professor of environmental health sciences at Columbia Mailman School. "Reducing levels of air pollution may prevent these adverse outcomes and lead to improvements in children's academic achievement."

The new findings align with prior Columbia research finding a DNA marker for PAH exposure was associated with altered development of self-regulatory capacity and ADHD symptoms.

The study followed 200 children enrolled in a longitudinal cohort study in Northern Manhattan and the Bronx led by CCCEH researchers. Researchers collected measures of prenatal airborne polycyclic aromatic hydrocarbons (PAH, a major component of air pollution) during the third trimester of pregnancy, a period when the fetus is highly vulnerable to environmental insults. Tests of inhibitory control were administered at or around age 10 and tests of academic achievement, at or around age 13.

Inhibitory Control and Learning

When students learn new concepts, they often need to override a previous habit in order to incorporate a new rule into a skill. For example, when learning to read a vowel a child will learn that the letter a has a short vowel sound "a as in apple" but a long sound when the consonant is followed by a "magic e," as in "rate."

The COVID-19 pandemic and the situations of stress and sadness associated with it have not significantly increased the prevalence of depression and anxiety among participants in the Brazilian Longitudinal Study of Adult Health (ELSA-Brazil) who live in the city of São Paulo.

ELSA-Brazil has been monitoring the overall health of 15,000 civil servants at six public universities and research centers in Brazil since 2008. The survey on mental health during the pandemic was conducted in São Paulo and involved 2,117 members of the staff of the University of São Paulo (USP) - in active service or retired - who are participants in the nationwide study and aged 50-80.

The survey is supported by São Paulo Research Foundation - FAPESP
and aims to compare mental health before and during the pandemic in both healthy subjects and people suffering from anxiety or depression.

"This is good news, but it's worth noting that São Paulo has one of the highest rates of prevalence of psychiatric disorders in the world, with about 20% of the population being affected. Similar studies to ours conducted in the UK, for example, point to 16% prevalence. The explanation could be what we call a ceiling effect: prevalence is already so high that it can't get any higher," André Brunoni,
principal investigator for the project, told. Brunoni is a professor at the University of São Paulo's Medical School (FM-USP).

The results of the study are reported in an article published in Psychological Medicine.They show prevalence falling from 23.5% to 21.1% for mental illness generally in 2020, from 3.3% to 2.8% for depression, and from 13.8% to 8% for anxiety.

In the three periods of the year during which information was collected on the mental health of the participants - May-July, July-September, and October-December - the prevalence of depression, anxiety and stress held steady or fell moderately.

"Of course, everyone is sadder and more worried about the situation," Brunoni said. "Our questionnaire showed 30% of respondents reporting depression or symptoms of anxiety. However, these were subjective assessments. The diagnoses pointed to stability or even a reduction. The same was true of symptoms of anxiety or depression."

According to Brunoni, psychiatrists only diagnose depression if patients display at least two major symptoms for more than two months (e.g. sadness and lack of pleasure from activities previously enjoyed) and five out of nine minor symptoms (anxiety, sleep disorders, weight loss or gain, thoughts of low self-worth, and alterations in libido).

The most vulnerable

The data described in the article indicates that the risk of mental illness was greater among the youngest and most vulnerable socially, such as women, subjects without a university degree, and nonwhites. "The only risk factor not among the classical elements of vulnerability in our society was age," Brunoni said. "The risk of mental illness was highest for the youngest participants in our study, the under-sixties. This was probably because older people were shielded during the pandemic and didn't have to go out to work even after mobility restrictions were lifted."

Another aspect observed in the study, and one that will be explored in more depth with new analyses, is the intensification of women's double burden. "Mental illness didn't increase among male respondents with children at home but did among women. We now want to think about the impact of having a paid job, doing the housework and caring for the children during lockdown," he explained.

Financial stability was also an important factor in the maintenance of mental health, even in highly stressful situations. The study sample was older, with a mean age of 62, and as civil servants the participants have job tenure as well as other forms of social protection not available to the general population.

"We believe age contributed more than security to the absence of an increase in psychiatric disorders. A study of adolescents conducted along the same lines would probably detect an increase in the diagnosis of mental problems," Brunoni said. The reason is that mental disorders are associated with genetic or biological vulnerability, as well as environmental factors such as external stress. "Mental illness typically peaks around the age of 20 or 30, when the subject is most exposed to the outside world. After that, it declines."

About 25% of the participants had been diagnosed with some kind of psychiatric disorder. "Looking back, these people aged 50-80 had been through dictatorship, hyperinflation, the Collor Plan [an economic program implemented in 1990 by Fernando Collor, Brazil's president until 1992, freezing all bank accounts, among other measures] and probably many losses in life. They've experienced a great many adversities and may have developed mental disorders if they had a genetic predisposition," Brunoni said.

Loneliness during the pandemic was also covered by the study and will be explored more deeply in future research. "Many respondents said technology was key to coping with solitude and keeping in touch with family and friends, albeit virtually," he noted. "This was important because people who report interpersonal difficulties run a heightened risk of experiencing symptoms of mental illness."