“Our main goal with this project is to be able to tell communities that are affected by extreme weather events whether they will continue to see more events like this in the future,” says Carl Schreck, senior research scientist with North Carolina State University’s North Carolina Institute for Climate Studies (NCICS). “Getting this information to them in a timely manner will help them make informed decisions about hardening infrastructure or rebuilding after a weather event.”

Schreck and a team of scientists from NC State, the National Oceanic and Atmospheric Administration (NOAA), the University of Colorado, Boulder and Princeton University set out to establish a routine process for evaluating extreme weather events. 

The test case for the study was an extreme heat wave that occurred in Texas and Louisiana in 2023. The event was notable for its duration – it lasted almost the entire summer. Most heat wave measurement metrics are designed for events that last three to seven days.

“The other interesting piece of this event is that it occurred within the daytime warming hole,” Schreck says. “The warming hole refers to an area in the central U.S. where temperatures have not warmed at the same rate that we see over most other places. This is because increased precipitation there has kept afternoon temperatures from warming.”

The scientists used a two-step process to determine whether the heat wave was an anomaly or part of a new pattern. First, they took historical data from heat monitoring stations across the U.S. from the past 100 years to see how unusual 2023 was. Then they compared that data with the frequency of heat waves in both past and present predictive computer models.

Comparing those predictive models can indicate whether climate change is playing a role in the event.

“A similar drought wouldn’t have been as hot 50 years ago,” Schreck says. “That tells us the heat wave is directly related to climate change and that we will see even hotter heat waves in the future.”

Now that these methods have been established, the researchers plan to use them to determine the role of climate change in future heat waves.

The work appears in Environmental Research: Climate and was supported by NOAA’s Climate Program Office and the U.S. Department of Commerce. David Coates and John Uehling, research associates at NCICS, and NC State research professors Xiangdong Zhang and Kenneth Kunkel are co-authors. David R. Easterling and Russell S. Vose, NOAA/National Centers for Environmental Information; Joseph J. Barsugli, University of Colorado Boulder; Andrew Hoell, NOAA/Physical Science Laboratory; Nathaniel C. Johnson, NOAA/Geophysical Fluid Dynamics Laboratory; and Zachary M. Labe, Princeton University, are also co-authors.  

“The evidence is clear; individuals should get vaccinated if they have conditions that place them at risk for severe disease. For older adults and those with chronic conditions, RSV should be considered as serious as the flu, and they should get vaccinated,” said Branche.

RSV is a significant cause of severe respiratory illness among older adults, especially those with underlying health conditions. Worldwide, RSV causes millions of infections, hundreds of thousands of hospitalizations, and tens of thousands of deaths annually in adults aged 60 and older. In the US, adults over 65 experience high rates of RSV-related hospital visits, intensive care unit admissions, and deaths. Older people with RSV are at higher risk of severe illness compared to those with influenza or COVID.

Vaccines Protect Against Severe Symptoms and Keep People Out of the Hospital

In 2023, the FDA approved three RSV vaccines for older adults. Studies have shown these vaccines to be effective, with the Pfizer, GSK, and Moderna vaccines preventing RSV pneumonia and bronchitis in more than 80 percent of participants.

A recent study published in The Lancet assessed the effectiveness of RSV vaccines using data from a large electronic health record network involving the Centers for Disease Control and Prevention (CDC) and multiple US healthcare systems. The study found that RSV vaccines were 80 percent effective in preventing hospitalization, ICU admission, and death among adults aged 60 and older. Vaccine effectiveness was consistent across age groups, including those 75 and older, and among immunocompromised individuals. The study did not find evidence of waning vaccine protection within the season.

However, the uptake of the RSV vaccine in the 2023-2024 winter season was low. An estimated 24 percent of US adults aged 60 years and older received the vaccine, compared to influenza vaccination rates, which approach 50 percent each year for the same group. “Providers were not sure how to apply the shared clinical decision-making recommendations in the first season, and there remains a general lack of knowledge among the medical community and the public on what constitutes a risk for severe disease and who needs to be protected,” said Branche.

Boosting Rates and Better Vaccines

Based on these findings, the US Advisory Committee on Immunization Practices (ACIP), a group of medical and public health experts that advises the CDC, updated guidelines in June 2024 to recommend RSV vaccination for all adults aged 75 and older, those 60 and older in long-term care facilities or with chronic and high-risk health conditions.

“This new data enabled the ACIP to make more definitive recommendations, which will build public confidence in the effectiveness of these vaccines and make implementation a lot easier for providers and pharmacies,” said Branche.

New research shows that vaccines that target multiple strains of the RSV virus, called bivalent vaccines, may provide longer protection. URMC infectious disease experts Edward Walsh, MD, and Ann Falsey, MD, helped lead an international study of a bivalent RSV vaccine developed by Pfizer, the results of which were recently detailed in the New England Journal of Medicine. The vaccine effectively prevented severe RSV-related lower respiratory tract illnesses over two RSV seasons, with an overall efficacy of more than 80 percent. The experimental vaccine was particularly effective in individuals aged 60-79.

The team’s work builds on about two decades of research into graphenes, another family of 2D materials with important uses across many domains but which exhibit some shortcomings compared to MXenes (pronounced “maxenes”).

MXenes are made of atomically thin layers of transition metal carbides, nitrides or carbonitrides. They originate in what’s called the MAX phase, whose name describes its signature components: the “M,” a transition metal such as titanium or chromium; an “A” element such as aluminum; and the “X,” representing carbon or nitrogen atoms. The components are packed into a layered structure. To synthesize MXenes, chemists have used acidic solutions to etch away the layers of “A” elements while leaving the other layers intact — a relatively simple, high-yield technique.

Several dozen MXenes with different combinations of “M” and “X” elements have been synthesized. The Nebraska team has focused on one little-studied version that contains chromium, titanium and carbon atoms, said Alexander Sinitskii, professor of chemistry and lead researcher.

“The field is rapidly growing,” Sinitskii said.

MXenes have proved useful in storing energy, purifying water, protecting against electromagnetic interference, biomedical applications and more.

The keys to their usefulness are their chemical and structural diversity, as well as their scalability and processability, said Sinitskii, who also is affiliated with the Nebraska Center for Materials and Nanoscience, a nationally recognized center of excellence that draws upon research expertise from three of the four University of Nebraska campuses.

MXenes have a large surface area and are easily tunable. They also have a strong response to light and are hydrophilic — attracted to water — due to their oxygen- and hydroxyl-terminated surfaces.

Sinitskii’s team has discovered that the MXene containing chromium and titanium has “a certain set of properties not seen in others.” Previous research by the Nebraska team on other MXene materials revealed their n-type (electron-rich) character and decreased conductivity in response to light. In contrast, the new material is the first MXene with demonstrated p-type (electron-deficient) property and increasing conductivity under illumination.

“These are very unusual characteristics for MXenes,” Sinitskii said. “In many electronic applications, both n- and p-type materials are required and used in combination. Previously studied MXenes were all n-type, but now we demonstrate the first p-type MXene. This should enable complex structures where complementary MXenes are used together to achieve new electronic functionalities.”

His team also has been able to produce larger, more uniform flakes of the chromium/titanium carbide MXene than previously available, which makes them easier to research and use.

The team’s research was published in the Oct. 1 issue of the journal Matter.

Other Husker authors are Saman Bagheri, postdoctoral research associate, chemistry; Michael J. Loes, graduate student, chemistry; Haidong Lu, research assistant professor, physics and astronomy; Rashmeet Khurana, graduate student, chemistry; Md. Ibrahim Kholil, graduate student, chemistry; and Alexei Gruverman, Mach Professor of physics and astronomy. Co-authors, all from the South Dakota School of Mines and Technology, are Alexey Lipatov, Khimananda Acharya and Tula R. Paudel.

To resolve this controversy, Dr. Ruijing Ni, the first author of the study published today in the journal One Earth, and her colleagues at the Max Planck Institute for Chemistry have conducted a comprehensive global meta-analysis with researchers from China, the USA, and Australia. The research team determined the data from 68 epidemiologic studies from 2019 conducted across 22 countries, including those in North America, Western Europe, East Asia, South Asia, and Africa. They conclude that there is now sufficient evidence with high confidence level to support an association between long-term exposure to ambient PM_2.5 and asthma.

11 percent of new cases of asthma in Germany are attributable to particulate matter

“We estimate that globally in 2019, almost a third of asthma cases are attributable to long-term PM_2.5 exposure, corresponding to 63.5 million existing cases and 11.4 million new cases. In Germany, the pollution may have been responsible for 11 percent of new asthma cases, which corresponds to 28,000 people. We also find that the risk of asthma associated with PM_2.5 is much higher in children than in adults, reflecting the age-related vulnerability,” says Dr. Ni.

Typically, the full maturation of lung and immune function is gradually completed until early adulthood. As a result, children may be more susceptible to air pollution exposure, which can lead to airway oxidative stress, inflammation, and hyper-responsiveness, as well as changes in immunological responses and respiratory sensitization to allergens. All these factors play a role in the development of asthma.

Further using these data, the research team established exposure-response curves for both childhood and adult asthma. Such curves are widely employed to quantitatively assess health risks by illustrating the relationship between the level of exposure to a particular substance, e.g., PM_2.5 and the magnitude of the effect it produces, e.g., asthma risk. The exposure-response curves were determined by incorporating evidence from countries and regions across various income levels, which capture the global variation in PM_2.5 exposure. “This initiative is important for quantifying global health effects of air pollution,” comments Prof. Yuming Guo, an epidemiologist from Monash University.

Countries with different income levels and particulate matter pollution considered

Populations in low- and middle-income countries (LMICs) are typically exposed to higher concentrations of air pollution and bear a greater burden of PM_2.5. In contrast, research on the health effects of PM_2.5 has been limited in these regions previously, with the majority of studies conducted in North America and Western Europe. Consequently, attempting a global health impact assessment of PM_2.5 exposure necessitates extrapolating exposure-response associations observed in high-income countries to LMICs. The approach may introduce large uncertainty due to the differences in air pollution sources, healthcare systems, and demographic characteristics between high-income countries and LMICs.

The inclusion of evidence from several LMICs mitigates the limitation in approach and enables the exposure-response curves to be applicable to assess city- to global-scale attributable burden of asthma, as well as asthma health benefits associated with air pollution reductions, e.g., health benefits obtained from policy-driven reductions in air pollution under different scenarios.

“Our findings highlight the urgent need for policymakers to enforce stringent legislation to continuously combat air pollution, while personal protective measures, such as wearing masks, can also help reduce individual exposure and mitigate the risk of asthma,” emphasizes Prof. Yafang Cheng, the corresponding author of the study and the director at the Max Planck Institute for Chemistry.

The study was conducted by researchers from Max Planck Institute for Chemistry (Germany), Institute of Atmospheric Physics at the Chinese Academy of Sciences (China), University of Washington (USA), and Monash University (Australia).

“Our goal was to design a printable concrete that performs better and is more eco-friendly,” said Osman Ozbulut, a professor at UVA’s Department of Civil and Environmental Engineering. “The addition of graphene to LC2 cement offers a unique opportunity to lower carbon emissions while maintaining the strength and flexibility required for 3D printed construction.”

The study, which explored the flow properties, mechanical performance and environmental impacts of this material, was led by visiting scholar Tugba Baytak and UVA’s Tawfeeq Gdeh, doctoral researchers at Resilient and Advanced Infrastructure Laboratory at University of Virginia. Collaborating with researchers at Virginia Transportation Research Council (VTRC), Baytak and Gdeh applied graphene — known for its outstanding mechanical properties — to LC2 cement, significantly improving its performance for 3D printing applications.

“This kind of innovation is essential for the future of construction, and I’m proud to be part of the team driving this forward,” said Baytak.

A key aspect of the research was a Life Cycle Assessment (LCA), conducted by Zhangfan Jiang, a postdoctoral researcher the Department of Civil and Environmental Engineering, in collaboration with Lisa Colosi Peterson, an environmental engineering professor at the University of Virginia. The LCA revealed that this graphene-enhanced LC2 concrete could reduce greenhouse gas emissions by approximately 31% compared to traditional printable concrete mixtures.

“Being able to see the full environmental footprint of this new concrete was important,” explained Jiang. “It not only exhibits better mechanical performance but also has a lower environmental impact, making 3D concrete construction technology more sustainable compared to traditional 3D printing methods with higher carbon emissions.”

“It’s rewarding to see science push us toward greener building practices,” said Colosi Peterson.

The partnership with VTRC allowed the UVA team to assess the material’s potential applications in transportation infrastructure, further showcasing its real-world potential. “The VTRC collaboration was essential in uncovering the fundamental properties of this new concrete,” added Ozbulut.

“It’s exciting to be part of a project that addresses both the technical demands of modern construction and the urgent need for more eco-friendly materials,” said Gdeh.

The research team included Tugba Baytak, a doctoral researcher from Istanbul Technical University and a visiting scholar at University of Virginia, Tawfeeq Gdeh, Zhangfan Jiang, Lisa Colosi, and Osman E. Ozbulut from the University of Virginia, and Gabriel Arce, a research scientist from the Virginia Transportation Research Council.

The article was entitled “Rheological, Mechanical, and Environmental Performance of Printable Graphene-Enhanced Cementitious Composites with Limestone and Calcined Clay” published in the Journal of Building Engineering, 2024.

This research was funded in part by the University of Virginia’s 3 Cavaliers Program and The Scientific and Technological Research Council of Turkey (TUBITAK).

A new technique for growing these microscopic crystals, published this week in Science, has not only found a new, more efficient way to build a useful type of quantum dot, but also opened up a whole group of novel chemical materials for future researchers’ exploration.

“I am excited to see how researchers across the globe can harness this technique to prepare previously unimaginable nanocrystals,” said first author Justin Ondry, a former postdoctoral researcher in UChicago’s Talapin Lab.

The team — which included researchers from the University of Chicago, University of California Berkeley, Northwestern University, the University of Colorado Boulder, and Argonne National Laboratory — achieved these remarkable results by replacing the organic solvents typically used to create nanocrystals with molten salt — literally superheated sodium chloride of the type sprinkled on baked potatoes.

“Sodium chloride is not a liquid in your mind, but assume you heat it to such a crazy temperature that it becomes a liquid. It looks like liquid. It has similar viscosity as water. It’s colorless. The only problem was that nobody ever considered these liquids as media for colloidal synthesis,” said Prof. Dmitri Talapin at the UChicago Pritzker School of Molecular Engineering (UChicago PME) and the Chemistry Department.

Why salt?

Quantum dots are among the more well-known nanocrystals, not only for their wide commercial uses but for the recent 2023 Nobel Prize in Chemistry given to the team that discovered them.

“If there is a material from the world of nano that has had an impact on the society in terms of applications, it’s the quantum dot,” said UC Berkeley Prof. Eran Rabani, a co-author of the paper.

However, much of the previous research on quantum dots, including the Nobel work, was around dots grown using combinations of elements from the second and sixth groups on the periodic table, Rabani said. These are called “II-VI” (two-six) materials.

More promising materials for quantum dots can be found elsewhere on the periodic table.

Materials found in the third and fifth groups of the periodic table (III-V materials) are used in the most efficient solar cells, brightest LEDs, most powerful semiconductor lasers, and fastest electronic devices. They would potentially make great quantum dots, but, with few exceptions, it was impossible to use them to grow nanocrystals in solution. The temperatures required to make these materials were too high for any known organic solvent.

Molten salt can handle the heat, making these previously inaccessible materials accessible.

“This distinct advance of molten salt synthesis that Prof. Talapin’s group has pioneered for the first time many materials for which previously colloidal synthesis was simply unavailable,” said co-author Richard D. Schaller, who has a joint appointment with Argonne National Laboratory and Northwestern University. “Fundamental as well as applied advances can now be made by with many of these newly available materials and at the same time there is now a whole new synthetic frontier available to the community.”

The Quantum Age

One of the reasons researchers synthesizing nanocrystals overlooked molten salt was because of its strong polarity, said UChicago graduate student Zirui Zhou, second author of the new paper.

Salt’s positively charged ions and negatively charged ions have a strong pull toward each other. Small things like nanocrystals have small surface charges, so researchers assumed the charge would be too weak to push back as salt’s ions pull in. Any growing crystals would be crushed before they could form a stable material.

Or so previous researchers thought.

“It’s a surprising observation,” Zhou said. “This is very contradictory to what scientists traditionally think about these systems.”

The new technique can mean new building blocks for better, faster quantum and classical computers, but for many on the research team, the truly exciting part is opening up new materials for study.

“Many eras in human history are defined by the materials humanity had available — think ‘Bronze Age’ or ‘Iron Age,'” Ondry said. “In this work we have unlocked the ability to synthesize nearly a dozen new nanocrystal compositions which will enable future technologies.”