The research team, led by Jeffrey Hartgerink, professor of chemistry and bioengineering, has developed peptide-based hydrogels that mimic the aligned structure of muscle and nerve tissues. Alignment is critical for the tissues’ functionality, but it is a challenging feature to reproduce in the lab, as it entails lining up individual cells.

For over ten years, the team has been designing multidomain peptides (MDPs) that self-assemble into nanofibers. These resemble the fibrous proteins found naturally in the body, much like a spiderweb at nanoscale.

In their latest study, published online and featured on the cover of the journal ACS Nano, the researchers discovered a new method to create aligned MDP nanofiber “noodles.” By first dissolving the peptides in water and then extruding them into a salty solution, they were able to create aligned peptide nanofibers — like twisted strands of rope smaller than a cell. By increasing the concentration of ions, or salt, in the solution and repeating the process, they achieved even greater alignment of the nanofibers.

“Our findings demonstrate that our method can produce aligned peptide nanofibers that effectively guide cell growth in a desired direction,” explained lead author Adam Farsheed, who recently received his Ph.D. in bioengineering from Rice. “This is a crucial step toward creating functional biological tissues for regenerative medicine applications.”

One of the key findings of the study was an unexpected discovery: When the alignment of the peptide nanofibers was too strong, the cells no longer aligned. Further investigation revealed that the cells needed to be able to “pull” on the peptide nanofibers to recognize the alignment. When the nanofibers were too rigid, the cells were unable to exert this force and failed to arrange themselves in the desired configuration.

“This insight into cell behavior could have broader implications for tissue engineering and biomaterial design,” said Hartgerink. “Understanding how cells interact with these materials at the nanoscale could lead to more effective strategies for building tissues.”

Additional study co-authors from Rice include chemistry department Ph.D. graduates Tracy Yu and Carson Cole, graduate student Joseph Swain, and undergraduate researcher Adam Thomas. Bioengineering undergraduate researcher Jonathan Makhoul, graduate student Eric Garcia Huitron, and Professor K. Jane Grande-Allen were also co-authors on the study. The team of researchers from the University of Houston includes Ph.D. student Christian Zevallos-Delgado, research assistant Sajede Saeidifard, research assistant professor Manmohan Singh and engineering professor Kirill Larin.

This work was supported in part by grants from the National Institutes of Health (R01DE021798, R01EY022362, R01HD095520, R01EY030063), the National Science Foundation (2129122), the National Science Foundation Graduate Research Fellowship Program, and the Welch Foundation (C-2141). The content in this news release is solely the responsibility of the authors and does not necessarily represent the official views of the funding organizations.

“I didn’t expect to see pollutant concentrations breach health benchmarks in bedrooms within an hour of gas stove use, and stay there for hours after the stove is turned off,” said Stanford Doerr School of Sustainability Professor Rob Jackson, senior author of the May 3 study in Science Advances. Pollution from gas and propane stoves isn’t just an issue for cooks or people in the kitchen, he said. “It’s the whole family’s problem.”

Among other negative health effects, breathing high levels of nitrogen dioxide, or NO₂, over time can intensify asthma attacks and has been linked to decreased lung development in children and early deaths.

Although most exposure to NO₂ is caused by cars and trucks burning fossil fuels, the researchers estimate that the mix of pollutants coming from gas and propane stoves overall may be responsible for as many as 200,000 current childhood asthma cases. One quarter of these can be attributed to nitrogen dioxide alone, according to the paper’s authors, who include scientists from Central California Asthma Collaborative, PSE Healthy Energy, and the Harvard T.H. Chan School of Public Health.

“We found that just how much gas you burn in your stove is by far the biggest factor affecting how much you’re exposed. And then, after that, do you have an effective range hood — and do you use it?” said lead study author Yannai Kashtan, a PhD student in Earth system science.

Little room for additional exposure

Beyond asthma cases, the long-term exposure to NO₂ in American households with gas stoves is high enough to cause thousands of deaths each year — possibly as many as 19,000 or 40% of the number of deaths linked annually to secondhand smoke. This estimate is based on the researchers’ new measurements and calculations of how much nitrogen dioxide people breathe at home because of gas stoves and the best available data on deaths from long-term exposure to outdoor NO₂, which is regulated by the U.S. Environmental Protection Agency.

The death toll estimate is approximate in part because it does not factor in the harmful effects of repeated exposure to extremely high levels of nitrogen dioxide in short bursts, as occurs in homes with gas stoves. It also relies on past studies of health impacts from nitrogen dioxide encountered outdoors, where additional pollutants from vehicles and power plants are present.

The researchers used sensors to measure concentrations of NO₂ throughout more than 100 homes of various sizes, layouts, and ventilation methods, before, during, and after stove use. They incorporated these measurements and other data into a model powered by National Institutes for Standards and Technology (NIST) software known as CONTAM for simulating airflow, contaminant transport, and room-by-room occupant exposure in buildings. This allowed them to estimate nationwide averages and short-term exposures under a range of realistic conditions and behaviors, and cross-check model outputs against their home measurements.

The results show that nationwide, typical use of a gas or propane stove increases exposure to nitrogen dioxide by an estimated 4 parts per billion, averaged over a year. That’s three quarters of the way to the nitrogen dioxide exposure level that the World Health Organization recognizes as unsafe in outdoor air. “That’s excluding all outdoor sources combined, so it makes it much more likely you’re going to exceed the limit,” said Kashtan.

Understanding how gas stoves affect health

The study is the latest in a series from Jackson’s group at Stanford looking at indoor air pollution from gas stoves. Earlier studies documented the rate at which gas stoves emit other pollutants, including the greenhouse gas methane and the carcinogen benzene. But to understand the implications of stove emissions for human health, the researchers needed to find out how much pollutants spread through a home, build up, and eventually dissipate. “We’re moving from measuring how much pollution comes from stoves to how much pollution people actually breathe,” said Jackson, who is the Michelle and Kevin Douglas Provostial Professor in Earth System Science.

With any fuel source, particle pollution can rise from food cooking in a hot pan. The new research confirms that food emits little or no nitrogen dioxide as it cooks, however, and electric stoves produce no NO₂. “It’s the fuel, not the food,” said Jackson. “Electric stoves emit no nitrogen dioxide or benzene. If you own a gas or propane stove, you need to reduce pollutant exposures using ventilation.”

Home size matters

Even in larger homes, concentrations of nitrogen dioxide routinely spiked to unhealthy levels during and after cooking even if a range hood was on and venting air outdoors. But people who live in homes smaller than 800 square feet — about the size of a small two-bedroom apartment — are exposed to twice as much nitrogen dioxide over the course of a year compared to the national average, and four times more compared to those living in the largest homes, upwards of 3,000 square feet.

Because home size makes such a difference, there are also differences in exposure across racial, ethnic, and income groups. Compared to the national average, the researchers found long-term NO₂ exposure is 60% higher among American Indian and Alaska Native households, and 20% higher among Black and Hispanic or Latino households. This exposure to indoor air pollution from gas stoves compounds the fact that exposure to outdoor sources of nitrogen dioxide pollution, such as vehicle exhaust, is also typically higher among people in poorer, often minority, communities.

“People in poorer communities can’t always afford to change their appliances, or perhaps they rent and can’t replace appliances because they don’t own them,” Jackson said. “People in smaller homes are also breathing more pollution for the same stove use.”

This research was supported by HT, LLC.

Researchers say the drastic change in the region’s population of corals is sure to disrupt the delicate balance of the ecosystem and threaten marine biodiversity and coastal economies.

“Some fast-growing organisms, like algae, might thrive in the short term,” said the study’s lead author, Sara Swaminathan, an environmental engineering sciences Ph.D. candidate at the University of Florida. “But the loss of the susceptible corals could have long-lasting repercussions.”

Stony coral tissue loss disease, or SCTLD, was first reported off the coast of Miami in 2014 and has since moved throughout the Caribbean, having been identified in 18 countries and territories. Scientists don’t know what causes the disease, but it is thought to be a waterborne pathogen that spreads rapidly across the surface of the coral colony until, in most cases, no living tissue remains.

The research team analyzed existing data from the U.S. Virgin Islands as well as data from other U.S. territories in the Caribbean and western Atlantic, including Florida, Puerto Rico, and Dry Tortugas. They examined the effects of stony coral tissue loss disease on fish and benthic reef communities, which comprises anything living on the sea floor, like coral, algae, and sponges.

They found that the disease not only reduces susceptible coral populations but also diminishes crustose coralline algae, the resilient pink crust that is crucial for building reef structure. Consequently, certain fast-growing, weedy species, including macroalgae, cyanobacteria, and fire coral, thrive in the absence of competitors, spreading into the vacant spaces left by the decimated corals.

Swaminathan explained that fast-growing species benefitting from the disease create a more seaweed-dominated environment compared to the rock-hard reef structures.

“Macroalgae doesn’t support as much biodiversity because it doesn’t create a hard habitat,” she said. “It might be a positive for herbivores but not for other organisms that need places to settle and grow, hide, or mate.”

In fact, the researchers found that the disease’s impact varies among types of fish, and some associations are positive. The study revealed that the rugosity of the coral — the roughness of the habitat — plays more of a factor for the fish than whether the coral is alive or dead.

“Some infectious diseases can affect entire ecosystems, but SCTLD is particularly impactful,” said Kevin Lafferty, a senior scientist with the U.S. Geological Survey and leading expert on marine diseases. “And its impacts are complex, with some winners among the losers.”

In addition to Swaminathan and Lafferty, the research team included Andrew Altieri, an assistant professor in the Herbert Wertheim College of Engineering and associate director of UF’s Center for Coastal Solutions, and Nicole Knight, a post-doctoral researcher at the University of British Columbia. The work was funded by the U.S. Geological Survey and the National Science Foundation.

Across the Caribbean, international agencies, marine biologists and conservationists are responding to the environmental crisis, working to understand the mechanisms driving stony coral tissue loss disease and developing potential treatments. Probiotics have shown promise in slowing down or stopping active lesions when applied to affected corals, and so far, the disease has not spread beyond the western Atlantic and Caribbean.

“Coral reefs are biodiversity hotspots that serve as vital habitats for countless marine species, providing food, shelter, and breeding grounds,” Altieri said. “They are natural protectors of our coastlines, and the loss of these reefs threatens the livelihoods of coastal communities dependent on fishing and tourism. We need to protect and preserve them.”

The T cells of the immune system are the main players in the defense against viral infections and tumor cells. On the other hand, they attack the body’s own healthy tissue in autoimmune reactions, which can even be fatal. The body must therefore keep a tight control on T cell activity.

A large number of molecules and messenger are involved in the highly complex regulation of T cell activity. Only recently have researchers discovered that another group of immune cells contibutes to the control of T cell activity. Natural killer cells (NK cells) are part of the innate immunity, i.e. the rapid response force that quickly detects and eliminates infected or malignant cells.

“Studies have shown that NK cells can also kill activated T cells and thus limit their proliferation,” says Michael Platten, Head of Department at the DKFZ and Director of the Neurological University Clinic Mannheim. “However, until now we did not know which feature characterizes T cells as a target for the NK cell.”

When screening activated T cells from healthy donors, Platten’s team identified the protein B7H6 as a recognition molecule for NK cell attacks in a new study. Activated T cells from the blood of patients with autoimmune diseases, cancer or viral infections expose large amounts of B7H6 on their surface. Co-culture experiments in the culture dish showed that NK cells recognize the activated T cells by their B7H6 expression. In contrast, T cells whose B7H6 gene was destroyed with the CRISPR-Cas were protected from the lethal attack of the NK cells.

“The elimination of T cells by NK cells is triggered by an intrinsic mechanism of the T cells. The activated T cells temporarily identify themselves as targets for NK-induced cell lysis,” explains Michael Kilian, first author of the publication, and adds: “This may limit excessive activation and expansion of T cells as a control mechanism to curb destructive immune responses.”

Immune checkpoint inhibitor therapies are neutralized by NK cells

“We now know a number of so-called checkpoint molecules that reduce or enhance the activation of T cells and thus modulate the course of immune reactions. B7H6 can now be classified as a further inhibitory immune checkpoint on T cells,” explains study leader Platten.

Some widespread cancer therapies with drugs from the checkpoint inhibitor (ICI) group are targeting certain inhibitory checkpoint molecules. They activate the immune system against the tumor by releasing the immune brakes. Could the B7H6-mediated elimination of tumor-reactive T cells possibly counteract the effect of ICI cancer immunotherapy? The researchers tested this using tissue samples from patients with esophageal cancer who had received ICI therapy. Those patients who had not responded to ICI had a higher number of NK cells in the tumor tissue and actually had a shorter progression-free survival time.

Cellular immunotherapy more effective in the absence of NK cells

Cellular immunotherapies are becoming increasingly important in cancer medicine. For example, some forms of blood cancer are now often treated with so-called CAR-T cells, which are equipped with customized receptors against the cancer. However, the success of therapy is often limited as the number of therapeutic cells in the patient’s body declines rapidly.

The therapeutic CAR-T cells also carry B7H6 on the cell surface. Could NK cells be responsible for the rapid decline in their numbers after the start of therapy? Experiments with a humanized mouse model suggest this: if NK cells were added during CAR-T cell treatment of leukaemia, the number of therapeutic cells decreased, while the tumour load increased.

“NK control of T cells has the potential to interfere with various forms of cancer immunotherapy. By specifically intervening in this process, it may be possible to modulate T cell immune responses in the future,” explains Michael Platten, head of the current study. With the help of the CRISPR-Cas gene scissors, the researchers now want to protect CAR-T cells from elimination by NK cells in a clinical trial together with the Department of Haematology and Oncology at Heidelberg University Hospital and thus improve the effectiveness of cellular immunotherapy.

Her research and teaching focus on positive psychology, media and new communication technologies, and media and spirituality. The study, published April 13 in Society for Research in Child Development (SRCD), investigates how adolescents perceive and engage with digital communication, including connectedness, positive social comparison, authentic self-presentation, civil participation and self-control.

“This was such an amazing research study to be part of as we all are craving more nuanced answers on how digital technologies affect our children,” said Janicke-Bowles.

Janicke-Bowles’ research contributes to the understanding of digital flourishing (positive social media experiences) among adolescents, highlighting the importance of supportive parental mediation and digital skills in promoting positive digital engagement. Moving forward, interventions aimed at enhancing digital flourishing should consider the role of parental guidance and support in shaping adolescents’ online experiences.

• Adolescents who flourish in their digital communication over time are more likely to have parents who know their way around technology and who actively support their children to positively communicate online.
• For adolescents who digitally flourish less, their self-control over digital communication decreases.
• To increase digital flourishing, interventions can aim in assisting adolescents in their control over their digital communication and encourage parents to take an active role in their young adults’ digital communication.

These findings underscore the significance of parental influence and support in fostering positive digital communication experiences among adolescents.

In addition to her recent research, Janicke-Bowles has a distinguished history of exploring the intersection of media and psychology. As a member of a research team from Florida State and Penn State universities, she received a $1.9 million grant from the John Templeton Foundation to investigate the impact of media content on self-transcendent emotions. Her academic journey, spanning from clinical and media psychology in Germany to mass communication in the United States, underscores her commitment to understanding the profound effects of media on human experiences.

Spintronic devices harness the spin of an electron, rather than its charge, to create current and move information through electronic devices.

“One of the goals in spintronics is to move spin information through a material without also having to move the associated charge, because moving the charge takes more energy — it’s why your phone and computer get hot when you use them for a long time,” says David Waldeck, professor of chemistry in Pitt’s Kenneth P. Dietrich School of Arts and Sciences and co-corresponding author of the work.

Chiral solids are materials that cannot be superimposed on their mirror image — think of your left and right hands, for example. A left-handed glove does not fit on your right hand, and vice-versa. Chirality in spintronic materials allows researchers to control the direction of spin within the material.

“Prior to this work, it was thought that the sense of chirality, or ‘handedness,’ of a material was very important to how and whether the spin would move through that material,” says Dali Sun, associate professor of physics, member of the Organic and Carbon Electronics Lab (ORaCEL) at North Carolina State University and co-corresponding author of the work.

“And when you’re moving the whole electron through the material that is still true. But we found that if you inject pure spin into a chiral material, the absorption of spin current strongly depends on the angle between the spin polarization and chiral axis; in other words, whether the spin polarization is aligned parallel or perpendicular to the chiral axis.”

“We used two different approaches, microwave particle excitation and ultrafast laser heating, to inject pure spin into the selected chiral materials in this study, and both approaches gave us the same conclusion,” says Jun Liu, associate professor of mechanical and aerospace engineering, member of ORaCEL at NC State and co-corresponding author of the work.

“The chiral materials we chose are two chiral cobalt oxide thin films, each with a different chirality, or ‘handedness,'” Liu says. “Non-chiral cobalt oxide thin films are commonly used in modern electronics.”

When the team injected pure spin aligned perpendicular to the material’s chiral axis, they noted that the spin did not travel through the material. However, when the pure spin was aligned either parallel or anti-parallel to the chiral axis, its absorption, or ability to pass through the material, improved by 3000%.

“Since spin can only pass through these chiral materials in one direction, this could enable us to design chiral gateways for use in electronic devices,” Sun says. “And this work also challenges some of what we thought we knew about chiral materials and spin, which is something we want to explore further.”

The work appears in Science Advances and is supported by the Department of Energy under award numbers DE-SC0020992 and ER46430; the Air Force Office of Scientific Research, Multidisciplinary University Research Initiatives (MURI) Program under award numbers FA9550-23-1-0311and FA9550-23-1-0368; and the National Science Foundation under award numbers DMR 2011978 and NSF-ECCS 2246254.

NC State postdoctoral researcher Rui Sun, NC State graduate student Ziqi Wang, and University of Pittsburgh Research Assistant Professor Brian Bloom are co-first authors.

Among those algae most closely related to land plants, diverse body types are found — ranging from single-celled algae to more complex cell filaments. From this group of relatives, an international group of researchers led by the Universities of Göttingen and Nebraska-Lincoln has now generated the first genome data of such complex specimens, on four filamentous “star algae” of the genus Zygnema. Their results were published in Nature Genetics.

The researchers worked with four algal strains in total, two from a culture collection in the USA and two that have been kept safe in the Algal Culture Collection at Göttingen University (SAG). The research involved more than 50 scientists from nine countries who combined a range of cutting-edge sequencing techniques to elucidate the entire DNA sequence of these algae. The advanced methods enabled them to generate complete genomes for these organisms at the level of whole chromosomes — something that had never been done before on this group of algae. Comparing the genes on the genomes with those of other plants and algae led to the discovery of specific overabundances of signalling genes and environmental response factors. Dr Iker Irisarri, Leibniz Institute for the Analysis of Biodiversity Change, explains: “Many of these genes underpin molecular functions that were important for the emergence of the first multicellular terrestrial plants. It is fascinating that the genetic building blocks, whose origins predate land plants by millions of years, duplicated and diversified in the ancestors of plants and algae and, in doing so, enabled the evolution of more specialized molecular machinery.”

Professor Jan de Vries, University of Göttingen, says: “Not only do we present a valuable, high-quality resource for the entire plant scientific community, who can now explore these genome data, our analyses uncovered intricate connections between environmental responses. This sheds light on one of land plants’ most important features: their ability to adjust their growth and development so that it aligns with the environment in which they dwell — a process known as developmental plasticity.”