“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.