The research group of corresponding author Laure Kayser, assistant professor in the Department of Materials Science and Engineering in UD’s College of Engineering with a joint appointment in the Department of Chemistry and Biochemistry in the College of Arts and Sciences, regularly works with PEDOT:PSS, a polymer that has both electronic and ionic conductivity, and was interested in finding ways to synthesize this material from plastic waste.

After connecting with Argonne chemist David Kaphan during an event hosted by UD’s research office, the research teams at UD and Argonne began evaluating the hypothesis that PEDOT:PSS could be made by sulfonating polystyrene, a synthetic plastic found in many types of disposable containers and packing materials.

Sulfonation is a common chemical reaction where a hydrogen atom is replaced by sulfonic acid; the process is used to create a variety of products such as dyes, drugs and ion exchange resins. These reactions can either be “hard” (with higher conversion efficiency but that require caustic reagents) or “soft” (a less efficient method but one that uses milder materials).

In this paper, the researchers wanted to find something in the middle: “A reagent that is efficient enough to get really high degrees of functionalization but that doesn’t mess up your polymer chain,” Kayser explained.

The researchers first turned to a method described in a previous study for sulfonating small molecules, one that showed promising results in terms of efficiency and yield, using 1,3-Disulfonic acid imidazolium chloride ([Dsim]Cl). But adding functional groups onto a polymer is more challenging than for a small molecule, the researchers explained, because not only are unwanted byproducts harder to separate, any small errors in the polymer chain can change its overall properties.

To address this challenge, the researchers embarked on many months of trial and error to find the optimal conditions that minimized side reactions, said Kelsey Koutsoukos, a materials science doctoral candidate and second author of this paper.

“We screened different organic solvents, different molar ratios of the sulfonating agent, and evaluated different temperatures and times to see which conditions were the best for achieving high degrees of sulfonation,” he said.

The researchers were able to find reaction conditions that resulted in high polymer sulfonation, minimal defects and high efficiency, all while using a mild sulfonating agent. And because the researchers were able to use polystyrene, specifically waste Styrofoam, as a starting material, their method also represents an efficient way to convert plastic waste into PEDOT:PSS.

Once the researchers had PEDOT:PSS in hand, they were able to compare how their waste-derived polymer performed compared to commercially available PEDOT:PSS.

“In this paper, we looked at two devices — an organic electronic transistor and a solar cell,” said Chun-Yuan Lo, a chemistry doctoral candidate and the paper’s first author. “The performance of both types of conductive polymers was comparable, and shows that our method is a very eco-friendly approach for converting polystyrene waste into high-value electronic materials.”

Specific analyses conducted at UD included X-ray photoelectron spectroscopy (XPS) at the surface analysis facility, film thickness analysis at the UD Nanofabrication Facility, and solar cell evaluation at the Institute of Energy Conversion. Argonne’s advanced spectroscopy equipment, such as carbon NMR, was used for detailed polymer characterization. Additional support was provided by materials science and engineering professor Robert Opila for solar cell analysis and by David C. Martin, the Karl W. and Renate Böer Chaired Professor of Materials Science and Engineering, for the electronic device performance analyses.

One unexpected finding related to the chemistry, the researchers added, is the ability to use stoichiometric ratios during the reaction.

“Typically, for sulfonation of polystyrene, you have to use an excess of really harsh reagents. Here, being able to use a stoichiometric ratio means that we can minimize the amount of waste being generated,” Koutsoukos said.

This finding is something the Kayser group will be looking into further as a way to “fine-tune” the degree of sulfonation. So far, they’ve found that by varying the ratio of starting materials, they can change the degree of sulfonation on the polymer. Along with studying how this degree of sulfonation impacts the electrical properties of PEDOT:PSS, the team is interested in seeing how this fine-tuning capability can be used for other applications, such as fuel cells or water filtration devices, where the degree of sulfonation greatly impacts a material’s properties.

“For the electronic devices community, the key takeaway is that you can make electronic materials from trash, and they perform just as well as what you would purchase commercially,” Kayser said. “For the more traditional polymer scientists, the fact that you can very efficiently and precisely control the degree of sulfonation is going to be of interest to a lot of different communities and applications.”

The researchers also see great potential for how this research can contribute to ongoing global sustainability efforts by providing a new way to convert waste products into value-added materials.

“Many scientists and researchers are working hard on upcycling and recycling efforts, either by chemical or mechanical means, and our study provides another example of how we can address this challenge,” Lo said.

The complete list of co-authors includes Chun-Yuan Lo, Kelsey Koutsoukos, Dan My Nguyen, Yuhang Wu, David Angel Trujillo, Tulaja Shrestha, Ethan Mackey, Vidhika Damani, Robert Opila, David Martin, and Laure Kayser from the University of Delaware and Tabitha Miller, Uddhav Kanbur, and David Kaphan from Argonne National Laboratory.

Her latest research examines the health records and health care use of youth, individuals under age 21, who likely have been involved or whose families have been involved in the justice system. The challenge was identifying youth who have been impacted by mass incarceration, as most health care systems don’t routinely ask about incarceration. Families may not disclose that information due to stigma, fear of child protective services involvement, or judgment.

“There are few, if any, large community-level studies about the health of youth affected by incarceration, or their family’s incarceration, using medical records,” explains Boch, an assistant professor at the University of Cincinnati College of Nursing. “Despite a lot of youth and families affected by incarceration, gaps remain in understanding its prevalence and consequences. There are numerous reasons for this, some include a lack of provider awareness, lack of curriculum in provider training, lack of funding for this research and lack of routine sensitive screening for exposure.”

Boch and her research team searched the electronic medical records for justice-related keywords such as “prison,” “jail,” “sentenced,” “probation,” “parole,” and others, to determine the impact of incarceration. The researchers used data from Cincinnati Children’s Hospital collected over an 11-year period.

Their study, published in Academic Pediatrics, found that of the more than 1.7 million records reviewed, 38,263 (or 2.2%) of youth seen between January 2009 and December 2020 likely had a parent incarcerated or faced some type of confinement as a juvenile. This small percentage was also responsible for a disproportionate number of physical and mental health diagnoses and health care visits at Cincinnati Children’s. They were compared against a socio demographically matched sample without a justice keyword and the total sample population of youth.

Nearly 63.3% of all behavioral health inpatient admissions, 23.7% of all hospitalization inpatient days and 45.5% of all foster care visits were attributed to the 2.2% of youth who had documented probable personal or family justice system involvement. The findings complement another study led by Boch, published in 2021 using data from Nationwide Children’s Hospital in Columbus, Ohio.

Youth with a justice keyword in their record had 1.5 to 16.2 times the prevalence of various physical and mental health disorder groupings studied compared to matched youth who didn’t have a justice keyword but do have similar socioeconomic backgrounds. They also had 428.2 more physical health diagnoses and 269.2 more mental health diagnoses per 100 youth than the matched youth.

According to the study, youth with a justice keyword made up a large proportion of all of those who were diagnosed with health disorders or conditions at Cincinnati Children’s from 2009-2020. This includes 42.9% of all schizophrenia spectrum and other psychotic disorders, 42.1% of all bipolar and related disorders, 38.3% of all suicide and self-injury disorders, 24.5% of all trauma and stress related disorders, 44.9% of all shaken baby syndrome cases, 13.9% of all infectious diseases, 12.5% of speech language disorders and 12.8% of all youth pregnancies.

Nationally, about 7% of U.S. youth have had a parent incarcerated. Findings at Cincinnati Children’s and Nationwide Children’s Hospital in Columbus grossly underestimate the number of youth affected by incarceration or confinement, says Boch.

“Our data reflects families who disclosed and health providers who documented,” says Boch. “Families who refrain from disclosing or whose information is not documented were not represented which is a key limitation. This study is an attempt to uncover the size of the impact of mass incarceration on youth health in Cincinnati. Our health care systems and correctional systems clearly overlap and impact the lives of children.

“Replication of these findings in other communities would strengthen the growing justification for decarceration efforts and other reforms, especially if we want all U.S. children and families to thrive,” says Boch. “We will continue to have health care disparities and lead the world with poor health outcomes if we continue to lead in incarceration.”

Other co-authors of the study include Joshua Lambert, PhD, University of Cincinnati; Christopher Wilderman, PhD, Duke University; and Judith Dexheimer, PhD; Robert Kahn, MD; and Sarah Beal, PhD, all of the University of Cincinnati and Cincinnati Children’s.

The research study of Cincinnati youth was supported by Boch’s awards, including the Agency for Healthcare Research and Quality and Patient Centered Outcomes Research Institute (AHRQ/PCORI) K12 PEDSnet Scholars Learning Health Systems Career Development Program, internal funding from the University of Cincinnati College of Nursing Dean’s New Investigator Award, internal funding from the Cincinnati Children’s Hospital Medical Center James M. Anderson Center for Health Systems Excellence, and the NIH/NIMHD Loan Repayment Award for Clinician Scientists from Disadvantaged Backgrounds.

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“The way A-beta behaves in a variety of environments, including the human brain, is elusive,” said Brian Sun, an electrical systems and engineering alumnus of Washington University in St. Louis who is now an MD/PhD student in the School of Medicine.

“There’s an understanding of growth and decay that isn’t fully fleshed out,” he added.

That’s going to change, thanks to research recently published by Sun with colleagues in Associate Professor Matthew Lew’s lab at the Preston M. Green Department of Electrical and Systems Engineering (ESE) in WashU’s McKelvey School of Engineering. .

In first of its kind work, Sun and colleagues were able to make measurements of amyloid fibril beta-sheet assemblies, the underlying girders of the protein conglomeration, while they were changing. Previous high-resolution microscopy studies have only gotten static shots.

“We wanted to look specifically at dynamics of the underlying structure of A-beta that could be responsible for the changes we’re seeing, not just changes in the overall shape,” Sun said.

Lew uses Lego as an analogy, noting that current imaging technology shows you the full Lego building but not any look at how each individual brick is organized.

“The individual proteins are always changing in response to their environment,” Lew said. “It is like having certain Lego bricks causing other bricks to change their shape. The changing architecture of the proteins and the assembled aggregates together leads to the complexity of neurogenerative disease.”

The Lew lab has developed a new type of imaging tech that allows them to see the orientation and other minute details in nanostructures of biological systems that were previously invisible. Their technique — single-molecule orientation-localization microscopy (SMOLM) — uses the flashes of light from chemical probes to visualize the sheets of peptides underlying Aβ42, one kind of A-beta peptide.

Using SMOLM lets them look at individual orientation of the underlying beta-sheets to see the relationship between their organization and how that relates to the overall structure of the amyloid protein.

Multiple ways to remodel

Aβ42 is constantly changing, and step one is to try to find a method to the madness, a model or pattern of action to predict the protein’s behavior.

Now that the Lew lab can make these measurements, they made some intuitive observations and found some surprises hidden in the amyloid-beta architecture.

As can be expected, stable Aβ42 structures tend to retain stable underlying beta-sheetsgrowing structures have underlying beta-sheets that become more defined and rigid as the growth continues. Decaying structures exhibit increasingly disordered and less rigid beta-sheets. But they also found more than one way that Aβ42 can renovate.

“There are multiple different ways for Aβ42 structures to remain stable, or grow and decay,” Sun said.

The researchers also discovered that Aβ42 can grow and decay in ways that defy expectations. For example, Aβ42 can grow and decay in ways that preserve the underlying structure; sometimes there’s growth where the peptides just pile on, but the underlying beta-sheet orientations don’t change. In other cases, Aβ42 undergoes “stable decay,” where the opposite happens i.e. peptides leave, but beta-sheet structure remains. Finally, Aβ42’s beta-sheets sometimes reorganize and change orientations without immediate accompanying changes to the overall shape. These nano-structural reorganizations can predispose to future large-scale remodeling.

“Because SMOLM can track Aβ42’s underlying organization and not just its shape, we can see different kinds of subtypes of remodeling that aren’t visible to diffraction-limited, non-orientation imaging modalities,” Sun said.

If it all sounds a bit vague, keep in mind this is the first pass at even looking at these constantly shifting nanoscale structures. There were no previous works to compare notes, which makes it all the more notable that Sun crafted this work while juggling COVID-19 lockdown restrictions and his undergrad course load at WashU, which he completed in three years. It paves the way for him and others to start really getting a handle on amyloid architecture.

He’ll likely end up chasing more of these questions during the graduate phase of his MD/PhD training, where he plans to design nanoscale imaging systems and sensors that could reveal hidden mechanisms of difficult-to-treat diseases.

Sun credits WashU ESE department and the Lew lab for the rigorous training that made this study and academic trajectory possible, as well as WashU’s MSTP for supporting his continued research post-graduation. “I’m really glad I went through this journey,” he said.

Research reported in this publication was supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Number R35GM124858.

It has long been observed that organisms modify their traits, including reproductive patterns, in response to changes in their environment. This type of evolutionary plasticity has been observed in many types of animals in different habitats and with varying predators.

“We knew that fish who laid their eggs externally often adapted depending on the predators in the area, but we did not know how quickly species could change to these externals pressures,” said biology Professor Matthew Walsh, who recently published a paper on the topic in the journal Proceedings of the Royal Society B.

For his research, Dr. Walsh and biology lab technician Christopher Roden studied a small type of fish called the killifish that lives on the island of Trinidad in the Caribbean. Ranging in size from about 2 to 6 inches, the killifish are ideal for evolutionary studies because they are highly adaptable to their surroundings. Some types of killifish are even known to be amphibious, able to live on land to avoid predators.

The researchers tested the differences in egg-hatching plasticity among killifish living in sites with and without predators. They then examined the reproductive habits of those two populations by measuring the rates of hatching when eggs were laid submerged in water versus outside water on the surface of moist peat moss. The timing, hatching and offspring growth rates between the two groups of fish were then compared.

“Our study found striking differences in egg-hatching plasticity among killifish living in different habitats,” said Walsh. “This research provides new insights into how aquatic organisms adapt and evolve to changes in their environment. These findings may be particularly important in predicting how species are able to adapt to external pressures, such as those caused by climate change.”

Hibernophis breithaupti has unique anatomical features, in part because the specimens are articulated — meaning they were found all in one piece with the bones still arranged in the proper order — which is unusual for fossil snakes. Researchers believe it may be an early member of Booidea, a group that includes modern boas and pythons. Modern boas are widespread in the Americas, but their early evolution is not well understood.These new and very complete fossils add important new information, in particular, on the evolution of small, burrowing boas known as rubber boas.

Traditionally, there has been much debate on the evolution of small burrowing boas. Hibernophis breithaupti shows that northern and more central parts of North America might have been a key hub for their development. The discovery of these snakes curled together also hints at the oldest potential evidence for a behavior familiar to us today — hibernation in groups.

“Modern garter snakes are famous for gathering by the thousands to hibernate together in dens and burrows,” says Michael Caldwell, a U of A paleontologist who co-led the research along with his former graduate student Jasmine Croghan, and collaborators from Australia and Brazil. “They do this to conserve heat through the effect created by the ball of hibernating animals. It’s fascinating to see possible evidence of such social behavior or hibernation dating back 34 million years.”

In their study, recently published in Nature Catalysis, researchers demonstrated that carbon dioxide, a greenhouse gas, can be converted into a type of liquid fuel called methanol in a highly efficient manner.

This process happened by taking cobalt phthalocyanine (CoPc) molecules and spreading them evenly on carbon nanotubes, graphene-like tubes that have unique electrical properties. On their surface was an electrolyte solution, which, by running an electrical current through it, allowed CoPc molecules to take electrons and use them to turn carbon dioxide into methanol.

Using a special method based on in-situ spectroscopy to visualize the chemical reaction, researchers for the first time saw those molecules convert themselves into either methanol or carbon monoxide, which is not the desired product. They found that which path the reaction takes is decided by the environment where the carbon dioxide molecule reacts.

Tuning this environment by controlling how the CoPc catalyst was distributed on the carbon nanotube surface allowed carbon dioxide to be as much as eight times more likely to produce methanol, a discovery that could increase the efficiency of other catalytic processes and have a widespread impact on other fields, said Robert Baker, co-author of the study and a professor in chemistry and biochemistry at The Ohio State University.

“When you take carbon dioxide and convert it to another product, there are many different molecules you can make,” he said. “Methanol is definitely one of the most desirable because it has such a high energy density and can be used directly as an alternative fuel.”

While transforming waste molecules into useful products isn’t a new phenomenon, until now, researchers have often been unable to watch how the reaction actually takes place, a crucial insight into being able to optimize and improve the process.

“We might empirically optimize how something works, but we don’t really have an understanding of what makes it work, or what makes one catalyst work better than another catalyst,” said Baker, who specializes in surface chemistry, the study of how chemical reactions change when they occur on the face of different objects. “These are very difficult things to answer.”

But with the help of special techniques and computer modeling, the team has come significantly closer to grasping the complex process. In this study, researchers used a new type of vibrational spectroscopy, which allowed them to see how molecules behave on the surface, said Quansong Zhu, the lead author of the study and former Ohio State Presidential Scholar whose challenging measurements were vital to the discovery.

“We could tell by their vibrational signatures that it was the same molecule sitting in two different reaction environments,” said Zhu. “We were able to correlate that one of those reaction environments was responsible for producing methanol, which is valuable liquid fuel.”

According to the study, deeper analysis also found these molecules were directly interacting with supercharged particles called cations that enhanced the process of methanol formation.

More research is needed to learn more about what else these cations enable, but such a finding is key to achieving a more efficient way to create methanol, said Baker.

“We’re seeing systems that are very important and learning things about them that have been wondered about for a long time,” said Baker. “Understanding the unique chemistry that happens at a molecular level is really important to enabling these applications.”

Besides being a low-cost fuel for vehicles like planes, cars and shipping boats, methanol produced from renewable electricity could also be utilized for heating and power generation, and to advance future chemical discoveries.

“There’s a lot of exciting things that can come next based on what we’ve learned here, and some of that we’re already starting to do together,” said Baker. “The work is ongoing.”

Co-authors include Conor L. Rooney and Hailiang Wang from Yale University, Hadar Shema and Elad Gross from Hebrew University, and Christina Zeng and Julien A. Panetier from Binghamton University. This work was supported by the National Science Foundation and the United States-Israel Binational Science Foundation (BSF) International Collaboration.