Saturday, November 26, 2022

Rice lab’s catalyst could be key for hydrogen economy

Inexpensive catalyst uses energy from light to turn ammonia into hydrogen fuel

RICE UNIVERSITY

PHOTOCATALYST 1 — IMAGE: A REACTION CELL TESTS COPPER-IRON PLASMONIC PHOTOCATALYSTS FOR HYDROGEN PRODUCTION FROM AMMONIA. view more
CREDIT: BRANDON MARTIN/RICE UNIVERSITY

HOUSTON – (Nov. 24, 2022) – Rice University researchers have engineered a key light-activated nanomaterial for the hydrogen economy. Using only inexpensive raw materials, a team from Rice’s Laboratory for Nanophotonics, Syzygy Plasmonics Inc. and Princeton University’s Andlinger Center for Energy and the Environment created a scalable catalyst that needs only the power of light to convert ammonia into clean-burning hydrogen fuel.

The research is published online today in the journal Science.

The research follows government and industry investment to create infrastructure and markets for carbon-free liquid ammonia fuel that will not contribute to greenhouse warming. Liquid ammonia is easy to transport and packs a lot of energy, with one nitrogen and three hydrogen atoms per molecule. The new catalyst breaks those molecules into hydrogen gas, a clean-burning fuel, and nitrogen gas, the largest component of Earth’s atmosphere. And unlike traditional catalysts, it doesn’t require heat. Instead, it harvests energy from light, either sunlight or energy-stingy LEDs.

The pace of chemical reactions typically increases with temperature, and chemical producers have capitalized on this for more than a century by applying heat on an industrial scale. The burning of fossil fuels to raise the temperature of large reaction vessels by hundreds or thousands of degrees results in an enormous carbon footprint. Chemical producers also spend billions of dollars each year on thermocatalysts — materials that don’t react but further speed reactions under intense heating.

“Transition metals like iron are typically poor thermocatalysts,” said study co-author Naomi Halas of Rice. “This work shows they can be efficient plasmonic photocatalysts. It also demonstrates that photocatalysis can be efficiently performed with inexpensive LED photon sources.”

“This discovery paves the way for sustainable, low-cost hydrogen that could be produced locally rather than in massive centralized plants,” said Peter Nordlander, also a Rice co-author.

The best thermocatalysts are made from platinum and related precious metals like palladium, rhodium and ruthenium. Halas and Nordlander spent years developing light-activated, or plasmonic, metal nanoparticles. The best of these are also typically made with precious metals like silver and gold.

Following their 2011 discovery of plasmonic particles that give off short-lived, high-energy electrons called “hot carriers,” they discovered in 2016 that hot-carrier generators could be married with catalytic particles to produce hybrid “antenna-reactors,” where one part harvested energy from light and the other part used the energy to drive chemical reactions with surgical precision.

Halas, Nordlander, their students and collaborators have worked for years to find non-precious metal alternatives for both the energy-harvesting and reaction-speeding halves of antenna reactors. The new study is a culmination of that work. In it, Halas, Nordlander, Rice alumnus Hossein Robatjazi, Princeton engineer and physical chemist Emily Carter, and others show that antenna-reactor particles made of copper and iron are highly efficient at converting ammonia. The copper, energy-harvesting piece of the particles captures energy from visible light.

“In the absence of light, the copper-iron catalyst exhibited about 300 times lower reactivity than copper-ruthenium catalysts, which is not surprising given that ruthenium is a better thermocatalyst for this reaction,” said Robatjazi, a Ph.D. alumnus from Halas’ research group who is now chief scientist at Houston-based Syzygy Plasmonics. “Under illumination, the copper-iron showed efficiencies and reactivities that were similar to and comparable with those of copper-ruthenium.

Syzygy has licensed Rice’s antenna-reactor technology, and the study included scaled-up tests of the catalyst in the company’s commercially available, LED-powered reactors. In laboratory tests at Rice, the copper-iron catalysts had been illuminated with lasers. The Syzygy tests showed the catalysts retained their efficiency under LED illumination and at a scale 500 times larger than lab setup.

“This is the first report in the scientific literature to show that photocatalysis with LEDs can produce gram-scale quantities of hydrogen gas from ammonia,” Halas said. “This opens the door to entirely replace precious metals in plasmonic photocatalysis.”

“Given their potential for significantly reducing chemical sector carbon emissions, plasmonic antenna-reactor photocatalysts are worthy of further study,” Carter added. “These results are a great motivator. They suggest it is likely that other combinations of abundant metals could be used as cost-effective catalysts for a wide range of chemical reactions.”

Halas is Rice’s Stanley C. Moore Professor of Electrical and Computer Engineering and a professor of chemistry, bioengineering, physics and astronomy, and materials science and nanoengineering. Nordlander is Rice’s Wiess Chair and Professor of Physics and Astronomy, and professor of electrical and computer engineering, and materials science and nanoengineering. Carter is Princeton's Gerhard R. Andlinger Professor in Energy and Environment at the Andlinger Center for Energy and the Environment, senior strategic adviser for sustainability science at the Princeton Plasma Physics Laboratory, and professor of mechanical and aerospace engineering and of applied and computational mathematics. Robatjazi is also an adjunct professor of chemistry at Rice.

Halas and Nordlander are Syzygy co-founders and hold an equity stake in the company.

The research was supported by the Welch Foundation (C-1220, C-1222), the Air Force Office of Scientific Research (FA9550-15-1-0022), Syzygy Plasmonics, the Department of Defense and Princeton University.

Additional co-authors include Yigao Yuan, Jingyi Zhou, Aaron Bales, Lin Yuan, Minghe Lou and Minhan Lou of Rice, Linan Zhou of both Rice and South China University of Technology, Suman Khatiwada of Syzygy Plasmonics, and Junwei Lucas Bao of both Princeton and Boston College.

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A reaction cell (left) and the photocatalytic platform (right) used on tests of copper-iron plasmonic photocatalysts for hydrogen production from ammonia at Syzygy Plasmonics in Houston. All reaction energy for the catalysis came from LEDs that produced light with a wavelength of 470 nanometers.

CREDIT

Syzygy Plasmonics, Inc.

The photocatalytic platform used on tests of copper-iron plasmonic photocatalysts for hydrogen production from ammonia.

CREDIT

Photo by Brandon Martin/Rice University

Peer-reviewed paper:

"Earth-abundant photocatalyst for H2 generation from NH3 with light-emitting diode illumination" | Science | DOI: 10.1126/science.abn5636

Yigao Yuan, Linan Zhou, Hossein Robatjazi, Junwei Lucas Bao, Jingyi Zhou, Aaron Bayles, Lin Yuan, Minghe Lou, Minhan Lou, Suman Khatiwada, Emily A. Carter, Peter Nordlander, Naomi J. Halas

https://doi.org/10.1126/science.abn5636

VIDEO is available at:

https://youtu.be/EqZLykm0EXM

Video produced by Brandon Martin/Rice University

High-resolution IMAGES are available for download at:

https://news-network.rice.edu/news/files/2022/11/1205_PHOTOCAT-1-WEB.jpg

A reaction cell tests copper-iron plasmonic photocatalysts for hydrogen production from ammonia. (Credit: Photo by Brandon Martin/Rice University)

https://news-network.rice.edu/news/files/2022/11/1205_PHOTOCAT-2-WEB.jpg

The photocatalytic platform used on tests of copper-iron plasmonic photocatalysts for hydrogen production from ammonia. (Credit: Photo by Brandon Martin/Rice University)

https://news-network.rice.edu/news/files/2022/11/1205_PHOTOCAT-3-WEB.jpg

https://news-network.rice.edu/news/files/2022/11/1205_PHOTOCAT-4-WEB-Halas.jpg

CAPTION: Naomi Halas. (Credit: Photo by Jeff Fitlow/Rice University)

https://news-network.rice.edu/news/files/2022/11/1205_PHOTOCAT-5-WEB-Nordlander.jpg

CAPTION: Peter Nordlander. (Credit: Photo by Jeff Fitlow/Rice University)

https://news-network.rice.edu/news/files/2022/11/1205_PHOTOCAT-6-WEB-Robatjazi.jpg

CAPTION: Hossein Robatjazi. (Credit: Photo by Jeff Fitlow/Rice University)

JOURNAL

Science

DOI

10.1126/science.abn5636

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Earth-abundant photocatalyst for H2 generation from NH3 with light-emitting diode illumination

ARTICLE PUBLICATION DATE

24-Nov-2022

COI STATEMENT

Halas and Nordlander are Syzygy co-founders and hold an equity stake in the company.

Researchers create green fuel with the

flip of a light switch

Peer-Reviewed Publication

PRINCETON UNIVERSITY, ENGINEERING SCHOOL

High Performance Computer Center — IMAGE: COMPUTATIONS FOR THE PROJECT WAS PERFORMED AT PRINCETON'S HIGH PERFORMANCE COMPUTING RESEARCH CENTER. view more
CREDIT: PHOTO BY DENISE APPLEWHITE, PRINCETON UNIVERSITY OFFICE OF COMMUNICATIONS

Researchers at Princeton and Rice universities have combined iron, copper, and a simple LED light to demonstrate a low-cost technique that could be key to distributing hydrogen, a fuel that packs high amounts of energy with no carbon pollution.

The researchers used experiments and advanced computation to develop a technique using nanotechnology to split hydrogen from liquid ammonia, a process that until now has been expensive and energy intensive.

In an article published online Nov. 24 in the journal Science, the researchers describe how they used light from a standard LED to crack the ammonia without the need for high temperatures or expensive elements typically demanded by such chemistry. The technique overcomes a critical hurdle toward realizing hydrogen’s potential as a clean, low-emission fuel that could help meet energy demands without worsening climate change.

“We hear a lot about hydrogen being the ultimate clean fuel, if only it was less expensive and easy to store and retrieve for use,” said Naomi Halas, a professor at Rice University and one of the study’s principal authors. “This result demonstrates that we are moving rapidly towards that goal, with a new, streamlined way to release hydrogen on-demand from a practical hydrogen storage medium using earth-abundant materials and the technological breakthrough of solid-state lighting.”

Hydrogen offers many advantages as a green fuel including high energy density and zero carbon pollution. It is also used ubiquitously in industry, for example to make fertilizer, food, and metals. But pure hydrogen is expensive to compress for transport and is difficult to store for long periods. In recent years, scientists have sought to use intermediate chemicals to transport and store hydrogen. One of the most promising hydrogen carriers is ammonia (NH3), comprised of three hydrogen atoms and one nitrogen atom. Unlike pure hydrogen gas (H2), liquid ammonia, although hazardous, has existing systems for safe transportation and storage.

“This discovery paves the way for sustainable, low-cost hydrogen that could be produced locally rather than in massive centralized plants,” said Peter Nordlander, a professor at Rice and another principal author.

One persistent problem for advocates has been that cracking ammonia into hydrogen and nitrogen often requires high temperatures to drive the reaction. Conversion systems can require temperatures above 400 degrees Celsius (732 degrees Fahrenheit). That demands a lot of energy to convert the ammonia, as well as special equipment to handle the operation.

Researchers led by Halas and Nordlander at Rice University, and Emily Carter, the Gerhard R. Andlinger Professor in Energy and the Environment and Professor of Mechanical and Aerospace Engineering and Applied and Computational Mathematics at Princeton, wanted to transform the splitting process to make ammonia a more sustainable and economically viable carrier for hydrogen fuels. Using ammonia as a hydrogen carrier has drawn considerable research interest because of its potential to drive a hydrogen economy, as a recent review by the American Chemical Society shows.

Industrial operations often crack ammonia at high temperatures using a wide variety of materials as catalysts, which are materials that accelerate a chemical reaction without being changed by the reaction. Previous research has demonstrated that it is possible to lower the reaction temperature by using a ruthenium catalyst. But ruthenium, a metal in the platinum group, is expensive. The researchers believed they could use nanotechnology to allow cheaper elements like copper and iron to be used as a catalyst instead.

The researchers also wanted to tackle the energy cost of cracking ammonia. Current methods use a lot of heat to break the chemical bonds that hold ammonia molecules together. The researchers believed they could harness light to sever the chemical bonds like a scalpel rather than using heat to shatter them like a hammer. To do so, they turned to nanotechnology, along with a much cheaper catalyst containing iron and copper.

The combination of nanotechnology’s tiny metal structures and light is a relatively new field called plasmonics. By shining light into structures smaller than a single wavelength of light, engineers can manipulate the light waves in unusual and specific ways. In this case, the Rice team wanted to use this engineered light to excite electrons in the metal nanoparticles as a way to split the ammonia into its hydrogen and nitrogen components without the need for intense heat. Because plasmonics requires certain types of metals, such as copper, silver, or gold, the researchers added the iron to copper before creating the tiny structures. When finished, the copper structures behave as antennas to manipulate the light from the LED to excite the electrons to higher energies, while the iron atoms embedded in the copper act as catalysts to accelerate the reaction carried out by excited electrons.

The researchers created the structures and conducted the experiments in laboratories at Rice. They were able to adjust many variables around the reaction such as the pressure, the intensity of the light and the light’s wavelength. But calibrating the exact parameters was daunting. To investigate how these variables affected the reaction, the researchers worked with principal author Carter, who specializes in detailed investigations of reactions at the molecular level. Using Princeton’s high-performance computing system, the Terascale Infrastructure for Groundbreaking Research in Engineering and Science (TIGRESS), Carter and her postdoctoral fellow, Junwei Lucas Bao, ran the reactions through her specialized quantum mechanics simulator uniquely able to study excited electron catalysis. Molecular interactions of such reactions are incredibly complex, but Carter and her fellow researchers are able to use the simulator to understand which variables should be adjusted to further the reaction.

“With the quantum mechanics simulations, we can determine the rate-limiting reaction steps,” said Carter, who also holds appointments at Princeton’s Andlinger Center for Energy and the Environment, in applied and computational mathematics, and at the Princeton Plasma Physics Laboratory. “These are the bottlenecks.”

By fine-turning the process, while utilizing the atomic-scale understanding Carter and her team provided, the Rice team was able to consistently extract hydrogen from ammonia using only light from energy-efficient LEDs at room temperature with no additional heating. The researchers say the process is scalable. In further research, they plan to investigate other possible catalysts with an eye to increasing the process efficiency and decreasing the cost.

Carter, who also currently chairs the National Academies’ committee on carbon utilization, said a critical next step will be to decrease the costs and carbon pollution involved with creating the ammonia that begins the transportation cycle. Currently, most ammonia is created at high temperatures and pressures using fossil fuels. The process is both energy intensive and polluting. Carter said many researchers are working to develop green techniques for the production of ammonia as well.

“Hydrogen is used ubiquitously in industry and will be used increasingly as fuel as the world seeks to decarbonize its energy sources,” she said. “However, today it is mostly made unsustainably from natural gas – creating carbon dioxide emissions – and is difficult to transport and store. Hydrogen needs to be made and transported sustainably where it is needed. If carbon-emission-free ammonia could be produced, for example by electrolytic reduction of nitrogen using decarbonized electricity, it could be transported, stored, and possibly serve as an on-demand source of green hydrogen using the LED-illuminated iron-copper photocatalysts reported here.”

The article, Earth-abundant photocatalyst for H2 generation from NH3 with light-emitting diode illumination, was published in the Nov. 25 issue of Science. Besides Carter, Halas and Nordlander, co-authors include Hossein Robatjazi, who received his doctorate at Rice and is now chief scientist of Syzygy Plasmonics; Junwei Lucas Bao, who is now a professor at Boston College; Yigao Yuan, Jingyi Zhou, Aaron Bales, Lin Yuan, Minghe Lou and Minhan Lou of Rice University; Linan Zhou of both Rice and South China University of Technology, and Suman Khatiwada of Syzygy Plasmonics. Halas and Nordlander are co-founders of Syzygy and hold equity in the company.

Support for the research was provided in part by the Welch Foundation, the Air Force Office of Scientific Research, Syzygy Plasmonics, and the Department of Defense.

- Rice University’s Office of Public Affairs contributed to this article.

JOURNAL

Science

DOI

10.1126/science.abn5636

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Earth-abundant photocatalyst for H2 generation from NH3 with light-emitting diode illumination

ARTICLE PUBLICATION DATE

25-Nov-2022

COI STATEMENT

Halas and Nordlander are Syzygy co-founders and hold an equity stake in the company.

Stop counting cups. There’s an ocean of difference in our water needs

Peer-Reviewed Publication

UNIVERSITY OF WISCONSIN-MADISON

MADISON, Wisconsin — A new study of thousands of people reveals a wide range in the amount of water people consume around the globe and over their lifespans, definitively spilling the oft-repeated idea that eight, 8-ounce glasses meet the human body’s daily needs.

“The science has never supported the old eight glasses thing as an appropriate guideline, if only because it confused total water turnover with water from beverages and a lot of your water comes from the food you eat,” says Dale Schoeller, a University of Wisconsin–Madison emeritus professor of nutritional sciences who has been studying water and metabolism for decades. “But this work is the best we’ve done so far to measure how much water people actually consume on a daily basis — the turnover of water into and out of the body — and the major factors that drive water turnover.”

That’s not to say the new results settle on a new guideline. The study, published today in the journal Science, measured the water turnover of more than 5,600 people from 26 countries, ages ranging from 8 days to 96 years old, and found daily averages on a range between 1 liter per day and 6 liters per day.

“There are outliers, too, that are turning over as much as 10 liters a day,” says Schoeller, a co-author of the study. “The variation means pointing to one average doesn’t tell you much. The database we’ve put together shows us the big things that correlate with differences in water turnover.”

Previous studies of water turnover relied largely on volunteers to recall and self-report their water and food consumption, or were focused observations — of, say, a small group of young, male soldiers working outdoors in desert conditions — of questionable use as representative of most people.

The new research objectively measured the time it took water to move through the bodies of study participants by following the turnover of “labeled water.” Study subjects drank a measured amount of water containing trackable hydrogen and oxygen isotopes. Isotopes are atoms of a single element that have slightly different atomic weights, making them distinguishable from other atoms of the same element in a sample.

“If you measure the rate a person is eliminating those stable isotopes through their urine over the course of a week, the hydrogen isotope can tell you how much water they’re replacing and the elimination of the oxygen isotope can tell us how many calories they are burning,” says Schoeller, whose UW–Madison lab in the 1980s was the first to apply the labeled-water method to study people.

More than 90 researchers were involved in the study, which was led by a group that includes Yosuke Yamada, a former UW–Madison postdoctoral researcher in Schoeller’s lab and now section head of the National Institute of Biomedical Innovation, Health and Nutrition in Japan, and John Speakman, zoology professor at the University of Aberdeen in Scotland. They collected and analyzed data from participants, comparing environmental factors — such as temperature, humidity and altitude of the participants’ hometowns — to measured water turnover, energy expenditure, body mass, sex, age and athlete status.

The researchers also incorporated the United Nations’ Human Development Index, a composite measure of a country that combines life expectancy, schooling and economic factors.

Water turnover volume peaked for men in the study during their 20s, while women held a plateau from 20 through 55 years of age. Newborns, however, turned over the largest proportion daily, replacing about 28 percent of the water in their bodies every day.

Physical activity level and athletic status explained the largest proportion of the differences in water turnover, followed by sex, the Human Development Index, and age.

All things equal, men and women differ by about half a liter of water turnover. As a baseline of sorts, the study’s findings expect a male non-athlete (but of otherwise average physical activity) who is 20 years old, weighs 70kg (154 pounds), lives at sea level in a well-developed country in a mean air temperature of 10 degrees C (50 Fahrenheit) and a relative humidity of 50%, would take in and lose about 3.2 liters of water every day. A woman of the same age and activity level, weighing 60 kg (132 pounds) and living in the same spot, would go through 2.7 liters (91 ounces).

Doubling the energy a person uses will push their expected daily water turnover up by about liter, the researchers found. Fifty kilograms more body weight adds 0.7 liters a day. A 50% increase in humidity pushes water use up by 0.3 liters. Athletes use about a liter more than non-athletes.

The researchers found “hunter-gatherers, mixed farmers, and subsistence agriculturalists” all had higher water turnover than people who live in industrialized economies. In all, the lower your home country’s Human Development Index, the more water you go through in a day.

“That’s representing the combination of several factors,” Schoeller says. “Those people in low HDI countries are more likely to live in areas with higher average temperatures, more likely to be performing physical labor, and less likely to be inside in a climate-controlled building during the day. That, plus being less likely to have access to a sip of clean water whenever they need it, makes their water turnover higher.”

The measurements will improve our ability to predict more specific and accurate future water needs, especially in dire circumstances, according to Schoeller.

“Look at what's going on in Florida right now, or in Mississippi — where entire regions have been exposed by a calamity to water shortages,” he says. “The better we understand how much they need, the better prepared we are to respond in an emergency.”

And the better we can prepare for long-term needs and even notice short-term health concerns, the researchers believe.

“Determining how much water humans consume is of increasing importance because of population growth and growing climate change,” says Yamada. “Because water turnover is related to other important indicators of health, like physical activity and body fat percent, it has potential as a biomarker for metabolic health.”

The study and access to the data was funded by agencies around the world, including the International Atomic Energy Agency, the National Science Foundation and National Institutes of Health in the United States, and the Chinese Academy of Sciences.

###

— Chris Barncard, barncard@wisc.edu

JOURNAL

Science

DOI

10.1126/science.abm8668

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Variation in human water turnover associated with environmental and lifestyle factors

ARTICLE PUBLICATION DATE

25-Nov-2022

What determines water turnover in people around the world?

Peer-Reviewed Publication

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS)

A new global study of human water requirements by Yosuke Yamada and colleagues shows how water turnover – the water used by the body daily – differs and is determined by a variety of factors in people across the globe. Although data on water consumption and turnover are critical to global health decision-making and planning for future water needs, some recommendations for human water intake rely on self-reported data, which can be variable. Yamada et al. measured water turnover and total body water for 5,604 people, ages 8 days to 96 years, from 26 countries around the globe. Their method asks participants to drink a small amount of deuterium-enriched water, tracing the loss of deuterium to assess water turnover and its dilution to estimate total body water. The researchers confirmed that body size and composition, climate variables, pregnancy, and energy expenditure were all correlated with water turnover. People in countries with a low human development index (a measure of education, income, and life expectancy) had higher water turnover than those with a middle or high index, even when accounting for other environmental and physiological variables, they found. Turnover was greatest in 20- to 30-year-old men and 20- to 55-year-old women, and total body water was highest in adults 20 to 40 years old. Based on these data, the researchers also developed an equation that can be used to predict water usage for an individual.

A related podcast will be available at https://www.science.org/podcasts on Thursday, November 24.

JOURNAL

Science

DOI

10.1126/science.abm8668

ARTICLE TITLE

Variation in human water turnover associated with environmental and lifestyle factors

ARTICLE PUBLICATION DATE

25-Nov-2022

Penn Scientists develop 20-subtype mRNA flu vaccine to protect against future flu pandemics

Promising results in animal models help pave the way for clinical trials

Peer-Reviewed Publication

UNIVERSITY OF PENNSYLVANIA SCHOOL OF MEDICINE

PHILADELPHIA – An experimental mRNA-based vaccine against all 20 known subtypes of influenza virus provided broad protection from otherwise lethal flu strains in initial tests, and thus might serve one day as a general preventative measure against future flu pandemics, according to researchers from the Perelman School of Medicine at the University of Pennsylvania.

The “multivalent” vaccine, which the researchers describe in a paper published today in Science, uses the same messenger ribonucleic acid (mRNA) technology employed in the Pfizer and Moderna SARS-CoV-2 vaccines. This mRNA technology that enabled those COVID-19 vaccines was pioneered at Penn. Tests in animal models showed that the vaccine dramatically reduced signs of illness and protected from death, even when the animals were exposed to flu strains different from those used in making the vaccine.

“The idea here is to have a vaccine that will give people a baseline level of immune memory to diverse flu strains, so that there will be far less disease and death when the next flu pandemic occurs,” said study senior author Scott Hensley, PhD, a professor in of Microbiology at in the Perelman School of Medicine.

Hensley and his laboratory collaborated in the study with the laboratory of mRNA vaccine pioneer Drew Weissman, MD, PhD, the Roberts Family Professor in Vaccine Research and Director of Vaccine Research at Penn Medicine.

Influenza viruses periodically cause pandemics with enormous death tolls. The best known of these was the 1918-19 “Spanish flu” pandemic, which killed at least tens of millions of people worldwide. Flu viruses can circulate in birds, pigs, and other animals, and pandemics can start when one of these strains jumps to humans and acquires mutations that adapt it better for spreading among humans. Current flu vaccines are merely “seasonal” vaccines that protect against recently circulating strains, but would not be expected to protect against new, pandemic strains.

The strategy employed by the Penn Medicine researchers is to vaccinate using immunogens—a type of antigen that stimulates immune responses—from all known influenza subtypes in order to elicit broad protection. The vaccine is not expected to provide “sterilizing” immunity that completely prevents viral infections. Instead, the new study shows that the vaccine elicits a memory immune response that can be quickly recalled and adapted to new pandemic viral strains, significantly reducing severe illness and death from infections.

“It would be comparable to first-generation SARS-CoV-2 mRNA vaccines, which were targeted to the original Wuhan strain of the coronavirus,” Hensley said. “Against later variants such as Omicron, these original vaccines did not fully block viral infections, but they continue to provide durable protection against severe disease and death.”

The experimental vaccine, when injected and taken up by the cells of recipients, starts producing copies of a key flu virus protein, the hemagglutinin protein, for all twenty influenza hemagglutinin subtypes—H1 through H18 for influenza A viruses, and two more for influenza B viruses.

“For a conventional vaccine, immunizing against all these subtypes would be a major challenge, but with mRNA technology it’s relatively easy,” Hensley said.

In mice, the mRNA vaccine elicited high levels of antibodies, which stayed elevated for at least four months, and reacted strongly to all 20 flu subtypes. Moreover, the vaccine seemed relatively unaffected by prior influenza virus exposures, which can skew immune responses to conventional influenza vaccines. The researchers observed that the antibody response in the mice was strong and broad whether or not the animals had been exposed to flu virus before.

Hensley and his colleagues currently are designing human clinical trials, he said. The researchers envision that, if those trials are successful, the vaccine may be useful for eliciting long-term immune memory against all influenza subtypes in people of all age groups, including young children.

“We think this vaccine could significantly reduce the chances of ever getting a severe flu infection,” Hensley said.

In principle, he added, the same multivalent mRNA strategy can be used for other viruses with pandemic potential, including coronaviruses.

Support for the research was provided by the National Institute of Allergy and Infectious Diseases (75N93021C00015, 75N93019C00050, 1R01AI108686, and R56AI150677).

###

Penn Medicine is one of the world’s leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania (founded in 1765 as the nation’s first medical school) and the University of Pennsylvania Health System, which together form a $9.9 billion enterprise.

The Perelman School of Medicine has been ranked among the top medical schools in the United States for more than 20 years, according to U.S. News & World Report's survey of research-oriented medical schools. The School is consistently among the nation's top recipients of funding from the National Institutes of Health, with $546 million awarded in the 2021 fiscal year.

The University of Pennsylvania Health System’s patient care facilities include: the Hospital of the University of Pennsylvania and Penn Presbyterian Medical Center—which are recognized as one of the nation’s top “Honor Roll” hospitals by U.S. News & World Report—Chester County Hospital; Lancaster General Health; Penn Medicine Princeton Health; and Pennsylvania Hospital, the nation’s first hospital, founded in 1751. Additional facilities and enterprises include Good Shepherd Penn Partners, Penn Medicine at Home, Lancaster Behavioral Health Hospital, and Princeton House Behavioral Health, among others.

Penn Medicine is powered by a talented and dedicated workforce of more than 52,000 people. The organization also has alliances with top community health systems across both Southeastern Pennsylvania and Southern New Jersey, creating more options for patients no matter where they live.

Penn Medicine is committed to improving lives and health through a variety of community-based programs and activities. In fiscal year 2021, Penn Medicine provided more than $619 million to benefit our community.

JOURNAL

Science

METHOD OF RESEARCH

Randomized controlled/clinical trial

SUBJECT OF RESEARCH

Animals

ARTICLE PUBLICATION DATE

24-Nov-2022

Multivalent mRNA vaccine candidate another step closer to universal flu vaccine

Peer-Reviewed Publication

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS

Claudia Arevalo and colleagues have developed a mRNA lipid nanoparticle vaccine that contains antigens from all 20 known subtypes of influenza A and B viruses, a strategy that may serve as the basis for universal flu vaccines. Their vaccine produced high levels of cross-reactive and subtype-specific antibodies in mice and ferrets and could protect animals against disease symptoms and death after infection with both antigenically matched and mismatched strains of influenza. Even with increased global surveillance, it is difficult to predict which flu strain will cause the next flu pandemic, making a universal vaccine important. The approach by Arevalo et al. differs from previous attempts to craft a universal flu vaccine by including antigens specific to each subtype, rather than just a smaller set of antigens shared among subtypes. Following on the success of mRNA vaccines against SARS-CoV-2, the researchers prepared 20 different nanoparticle encapsulated mRNAs, each encoding a different hemagglutinin antigen – a highly immunogenic flu protein that helps the virus enter cells. Antibody levels remained mostly stable four months after vaccination in the mice. Multivalent protein vaccines produced using more traditional methods elicited fewer antibodies and were less protective compared to the multivalent mRNA vaccine in the animals. In a related Perspective, Alyson Kelvin and Darryl Falzarano discuss the results, noting that “questions remain regarding the regulation and approval pathway of such a vaccine that targets viruses of pandemic potential but are not currently in human circulation.”

JOURNAL

Science

DOI

10.1126/science.abm0271

ARTICLE TITLE

A multivalent nucleoside-modified mRNA vaccine against all known influenza virus subtypes

ARTICLE PUBLICATION DATE

25-Nov-2022

Review provides new perspective on grieving loss of a pet

A new review published in the CABI journal Human-Animal Interactions provides counselors with new perspectives to consider in their practice when working with clients who are grieving the loss of their pet.

Peer-Reviewed Publication

CABI

A new review published in the CABI journal Human-Animal Interactions provides counselors with new perspectives to consider in their practice when working with clients who are grieving the loss of their pet.

The research highlights how during the COVID-19 pandemic, there was more opportunity for people to spend longer with their pets – relying on them to help maintain a sense of normality and provide security during periods of isolation.

Dr Michelle Crossley, Assistant Professor at Rhode Island College, and Colleen Rolland, President and pet loss grief specialist for Association for Pet Loss and Bereavement (APLB), suggest that pets play a significant role in the lives of their caregivers.

However, they add that grieving the loss of a pet continues to be disenfranchised in society.

Dr Crossley said, “Perceptions of judgment can lead individuals to grieve the loss without social support.

“The present review builds on research in the field of pet loss and human bereavement and factors in the impact of the COVID-19 pandemic on human-animal attachment.

“A goal of the present review is to provide counsellors with perspectives to consider in their practice when working with clients who have attachments to their companion animals.

“It also aims to acknowledge the therapeutic benefits of working through the grief process to resolution as a way to continue the bond with a deceased pet.”

The researchers say that stigma associated with grieving a loss can complicate the healing process and that counselors would expect to see more clients wanting to discuss their grieving – particularly during the COVID-19 pandemic.

They add that while empathy may come more naturally when discussing human loss, there are other types of loss that are not acknowledged or given a similar amount of attention by society.

This includes death by suicide, a lost pregnancy/miscarriage, death from AIDS and the death of a pet.

Ms Rolland said, “When relationships are not valued by society, individuals are more likely to experience disenfranchised grief after a loss that cannot be resolved and may become complicated grief.

“The major goals of this review are to provide counsellors with an aspect to consider in their therapeutic work with clients dealing with grief and loss and present different factors that may impact how one grieves the loss of a pet.

“It also discusses considerations for counseling that can be utilized to foster a supportive and non-judgmental space where clients’ expressions of grief are validated.”

Dr Crossley and Ms Rolland, in their review, suggest that having a safe space to discuss the meanings associated with the companion animal relationship is beneficial for moving through the loss in a supportive environment, leading to the resolution of the pain of the loss.

Dr Crossley added, “When an individual loses a pet, it can be a traumatic experience, especially given the strength of attachment, the role the pet played in the life of the individual, as well as the circumstances and type of loss.

“Giving a voice to individuals grieving a disenfranchised loss is one way in which counsellors can help clients through pet loss.

“It is also important to integrate pet loss work into counseling interventions and coping strategies that are already being used in the therapeutic space.”

The researchers believe that group counselling sessions in person or web-based chatrooms can both work as healing spaces for those working through grief.

Counselors can also engage both children and adults who are navigating pet loss by providing them with supplies and space to paint, draw, or use figures to draw out their anxieties and fears about the loss, they state.

In conclusion, Dr Crossley and Ms Rolland argue that understanding the grief process of pet owners can better prepare professionals to foster non-judgmental spaces where clients can feel open to display their grief.

Furthermore, providing empathy and validating the feelings that any type of loss of a pet can create for the clients may lead to more open sharing among the community further enhancing the healing process and a possible societal shift in the recognition of grieving pet loss as a normative experience.

Full paper reference

Crossley, M., and Rolland, C., ‘Overcoming the Social Stigma of Losing a Pet: Considerations for Counseling Professionals,’ Human-Animal Interactions, 25 November (2022). DOI: 10.1079/hai.2022.0022

The paper can be read open access once the embargo lifts here: https://www.cabidigitallibrary.org/doi/10.1079/hai.2022.0022

Media enquiries

For more information and advance copy of the paper contact:

Dr Michelle Crossley, Assistant Professor, Rhode Island College – email: mcrossley@ric.edu

Wayne Coles, Communications Manager, CABI – email: w.coles@cabi.org

About Human—Animal Interactions

Human—Animal Interactions is an open access interdisciplinary journal devoted to the dissemination of research in all fields related to interactions between non-human animals and their human counterparts.

About CABI

CABI is an international not-for-profit organization that improves people’s lives by providing information and applying scientific expertise to solve problems in agriculture and the environment.

Through knowledge sharing and science, CABI helps address issues of global concern such as improving global food security and safeguarding the environment. We do this by helping farmers grow more and lose less of what they produce, combating threats to agriculture and the environment from pests and diseases, protecting biodiversity from invasive species, and improving access to agricultural and environmental scientific knowledge. Our 49-member countries guide and influence our core areas of work, which include development and research projects, scientific publishing and microbial services.

We gratefully acknowledge the core financial support from our member countries (and lead agencies) including the United Kingdom (Foreign, Commonwealth and Development Office), China (Chinese Ministry of Agriculture and Rural Affairs), Australia (Australian Centre for International Agricultural Research), Canada (Agriculture and Agri-Food Canada), Netherlands (Directorate-General for International Cooperation, and Switzerland (Swiss Agency for Development and Cooperation). Other sources of funding include programme/project funding from development agencies, the fees paid by our member countries and profits from our publishing activities which enable CABI to support rural development and scientific research around the world.

DOI

10.1079/hai.2022.0022

METHOD OF RESEARCH

Literature review

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Overcoming the Social Stigma of Losing a Pet: Considerations for Counseling Professionals

ARTICLE PUBLICATION DATE

25-Nov-2022

Risk of severe asthma attacks doubled after Covid-19 restrictions lifted

Peer-Reviewed Publication

QUEEN MARY UNIVERSITY OF LONDON

Adults with asthma had, at one point, an approximately doubled risk of a severe asthma attack after Covid-19 restrictions were relaxed in the UK, according to new research from Queen Mary University of London*, funded by Barts Charity.

Episodes of progressive worsening of asthma symptoms, termed exacerbations or asthma attacks, are the major cause of illness and death in this condition. Asthma affects more than 5 million people in the UK and more than 300 million globally. Symptoms include breathlessness and chest tightness as well as wheezing and coughing.

Published in Thorax and presented at today’s British Thoracic Society meeting, the research found an increased risk of these attacks after Covid-19 restrictions were relaxed. When restrictions were lifted, fewer people wore face coverings and there was more social mixing, and subsequently a higher risk of Covid-19 and other acute respiratory infections. The research also found that Covid-19 was not significantly more likely to trigger asthma attacks than other respiratory infections.

In April 2021, when social mixing restrictions and the need for face coverings started to be relaxed, 1.7 per cent of participants reported having a severe asthma attack in the previous month. In January 2022, this proportion more than doubled, going up to 3.7 per cent.

The study analysed data from 2,312 UK adults with asthma, participating in Queen Mary’s COVIDENCE UK study between November 2020 and April 2022. Details on face covering use, social mixing, and asthma symptoms were collected via monthly online questionnaires.

Professor Adrian Martineau, lead author of the research and Clinical Professor of Respiratory Infection and Immunity at Queen Mary University of London, said: “This research shows that relaxation of Covid-19 restrictions coincided with an increased risk of severe asthma attacks. Our study was observational, so it can’t prove cause-and-effect. But our findings do raise the possibility that certain elements of the public health measures introduced during the pandemic – such as wearing facemasks - could help in reducing respiratory illnesses moving forward”.

Dr Florence Tydeman, first author on the paper, added: “It is also reassuring to see that Covid-19 was not significantly more likely to trigger asthma attacks than other respiratory infections in our study participants.”

The study is the first to compare the influence of COVID-19 versus other respiratory infections on risk of asthma exacerbations. And it is one of few studies that looks at the impact of lifting national restrictions on people with asthma.

JOURNAL

Thorax

Trends and biases in African large carnivore population assessments: Identifying priorities and opportunities from a systematic review of two decades of research

Peer-Reviewed Publication

PEERJ

Lioness walking on re sand-dune — IMAGE: LIONESS WALKING ON RE SAND-DUNE view more
CREDIT: CHRIS STENGER

African large carnivores have undergone significant range and population declines over recent decades. Although conservation planning and the management of threatened species requires accurate assessments of population status and monitoring of trends, there is evidence that biodiversity monitoring may not be evenly distributed or occurring where most needed.

New research published in the Open Access, peer-reviewed journal PeerJ provides the first systematic review of African large carnivore population assessments published over the last two decades (2000-2020), to investigate trends in research effort and identify knowledge gaps. The article is a timely review for a very important conservation topic, and provides an informed broad-scale framework for decision-making that is currently lacking in the field of large carnivore research in Africa - to guide funding, research investment, and priorities.

Researchers from the University of Oxford, the University of KwaZulu-Natal, Endangered Wildlife Trust, South Africa and Panthera used generalised linear models and generalised linear mixed models to identify taxonomic and geographical biases in previously published research into large carnivores in Africa, and also uncovered biases associated with land use type and author nationality.

“Research effort is significantly biassed towards lions (Panthera leo) and against striped hyena (Hyaena hyaena), despite the latter being the species with the widest continental range. African wild dogs (Lycaon pictus) also exhibited a negative bias in research attention, although this is partly explained by its relatively restricted distribution,” write the authors. “Our findings highlight the urgent need for additional cheetah population assessments, particularly in northern, western, and central Africa. Due to their large country ranges, studies in Chad and Ethiopia should especially be considered a priority.”

Population assessments have been biassed towards southern and eastern Africa, particularly South Africa and Kenya. Northern, western, and central Africa are generally under-represented. Most studies have been carried out in photographic tourism protected areas under government management, while non-protected and trophy hunting areas received less research attention.

Outside South Africa, 41% of studies did not include authors from the study country, suggesting that significant opportunities exist for capacity building. Overall, large parts of Africa remain under-represented in the literature, and opportunities exist for further research on most species and in most countries.

The authors developed recommendations for actions aimed at overcoming the identified biases and provide researchers, practitioners, and policymakers with priorities to help inform future research and monitoring agendas.

Recommendations

Reducing the identified geographical and taxonomic biases in population assessments would help ensure that all species and areas of conservation importance have an adequate knowledge base available, with the potential to improve their conservation outlook.

Geographical biases in research and assessments are immediate hurdles for science-based conservation management of African large carnivores. As a result, northern, western, and central Africa should be considered priority regions for future research.

Increased attention should in particular be given to the twenty-six countries which currently lack any published estimates, especially Angola, DRC, South Sudan, and Chad, given their considerable large carnivore country ranges and their potential importance for the conservation of these species.

Building capacity of researchers and practitioners in large carnivore survey and monitoring techniques in under-represented areas should be a priority. The fact that only 59% of studies outside of South Africa included a co-author from the study country reinforces suggestions that research in developing countries is disproportionately led by scientists from more developed areas, and shows there is considerable need for such capacity building efforts.

Donors and foreign researchers should maximise the involvement of local scientists, students, and practitioners in future assessments, including through capacity building initiatives such as the provision of training, funding, and equipment. Conservation donors and funders should encourage efforts in understudied regions, as well as for understudied species, to ensure that conservation research occurs where it is most needed.

On a species level, population assessments of striped hyena are needed, and further population assessments of African wild dogs are essential, particularly given the species is classified as Endangered. Such efforts are especially required in countries that have been identified as critical for the species, but where no recent assessments have been carried out (e.g. Botswana and Tanzania).

Urgent need for additional cheetah population assessments, particularly in northern, western, and central Africa. Due to their large country ranges, studies in Chad and Ethiopia should especially be considered a priority. As in the case of African wild dog, development and standardisation of cheetah population monitoring techniques, including the exploration of citizen-science based approaches, are recommended.

JOURNAL

PeerJ

DOI

10.7717/peerj.14354

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Trends and biases in African large carnivore population assessments: Identifying priorities and opportunities from a systematic review of two decades of research

ARTICLE PUBLICATION DATE

25-Nov-2022