In a new study in the journal Science Advances, a multidisciplinary team of researchers found the coatings prevented infection in live mice and mapped strain in commercial implants applied to sheep spines to warn of various implant or healing failures.

“This is a combination of bio-inspired nanomaterial design with flexible electronics to battle a complicated, long-term biomedical problem,” said study leader Qing Cao, a U. of I. professor of materials science and engineering.

Both infection and device failure are major problems with orthopedic implants, each affecting up to 10% of patients, Cao said. Several approaches to fighting infection have been attempted, but all have severe limitations, he said: Biofilms can still form on water-repelling surfaces, and coatings laden with antibiotic chemicals or drugs run out in a span of months and have toxic effects on the surrounding tissue with little efficacy against drug-resistant strains of bacterial pathogens.

Taking inspiration from the naturally antibacterial wings of cicadas and dragonflies, the Illinois team created a thin foil patterned with nanoscale pillars like those found on the insects’ wings. When a bacterial cell attempts to bind to the foil, the pillars puncture the cell wall, killing it.

“Using a mechanical approach to killing bacteria allowed us to bypass a lot of the problems with chemical approaches, while still giving us the flexibility needed to apply the coating to implant surfaces,” said pathobiology professor Gee Lau, a coauthor of the study.

On the back side of the nanostructured foil, where it contacts the implant device, the researchers integrated arrays of highly sensitive, flexible electronic sensors to monitor strain. This could help physicians watch the healing progress of individual patients, guide their rehabilitation to shorten the recovery time and minimize risks, and repair or replace devices before they hit the point of failure, the researchers said.

The engineering group then teamed up with veterinary clinical medicine professor Annette McCoy to test their prototype devices. They implanted the foils in live mice and monitored them for any sign of infection, even when bacteria were introduced. They also applied the coatings to commercially available spinal implants and monitored strain to the implants in sheep spines under normal load for device failure diagnosis. The coatings performed both functions well.

The prototype electronics required wires, but the researchers next plan to develop wireless power and data communications interfaces for their coatings, a crucial step for clinical application, Cao said. They also are working to develop large-scale production of the nanopillar-textured bacteria-killing foil.

“These types of antibacterial coatings have a lot of potential applications, and since ours uses a mechanical mechanism, it has potential for places where chemicals or heavy metal ions — as are used in commercial antimicrobial coatings now — would be detrimental,” Cao said.

The National Science Foundation and the U.S. Congressionally Directed Medical Research Programs supported this work.

“When pentacene is excited by light, the electrons in the material rapidly react,” explains Prof. Ralph Ernstorfer, a senior author of the study. “It was an open and very disputed question whether a photon excites two electrons directly or initially one electron, which subsequently shares its energy with another electron.”

To unravel this mystery the researchers used time- and angle-resolved photoemission spectroscopy, a cutting-edge technique to observe the dynamics of electrons on the femtosecond time scale, which is a billionth of a millionth of a second. This ultrafast electron movie camera enabled them to capture images of the fleeting excited electrons for the first time.

“Seeing these electrons was crucial to decipher the process,” says Alexander Neef, from the Fritz Haber Institute and the first author of the study. “An excited electron not only has a specific energy but also moves in distinct patterns, which are called orbitals. It is much easier to tell the electron apart if we can see their orbital shapes and how these change over time.”

With the images from the ultrafast electron movie at hand, the researchers decomposed the dynamics of the excited electrons for the first time based on their orbital characteristics. “We can now say with certainty that only one electron is excited directly and identified the mechanism of the excitation-doubling process,” adds Alexander Neef.

Knowing the mechanism of exciton fission is essential to using it for photovoltaic applications. A silicon solar cell enhanced with an excitation-doubling material could boost the solar-to-electricity efficiency by one-third. Such an advance could have enormous impacts since solar energy will be the dominant power source of the future. Already today large investments are flowing into the construction of these third-generation solar cells.

In a recent article published in PLoS Genetics, UCF College of Medicine microbiologist Dr. Salvador Almagro-Moreno uncovers the evolutionary origins of antimicrobial resistance (AMR) in bacteria. His studies on the bacterium that causes cholera, Vibrio cholerae, provide insight into deciphering what conditions must occur for infectious agents to become resistant.

“How AMR occurs in bacterial populations and the pathways leading to these new traits are still poorly understood,” he said. “This poses a major public health threat as antimicrobial resistance is on the rise.”

Dr. Almagro-Moreno studied genetic variants of a protein found in bacterial membranes called OmpU. Using computational and molecular approaches, his team found that several OmpU mutations in the cholera bacteria led to resistance to numerous antimicrobial agents. This resistance included antimicrobial peptides that act as defenses in the human gut. The researchers found that other OmpU variants did not provide these properties, making the protein an ideal system for deciphering the specific processes that occur to make some bacteria resistant to antimicrobials.

By comparing resistant and antibiotic sensitive variants, the researchers were able to identify specific parts of OmpU associated with the emergence of antibiotic resistance. They also discovered that the genetic material encoding these variants, along with associated traits, can be passed between bacterial cells, increasing therisk of spreading AMR in populations under antibiotic pressure.

By understanding how mutations occur, researchers can better understand and develop therapeutics to combat resistant infections. Dr. Almagro-Moreno is also looking at environmental factors such as pollution and warming of the oceans, as possible causes of resistant bacteria. “We are studying the genetic diversity ofenvironmental populations, including coastal Florida isolates, to develop a new approach to understandinghow antimicrobial resistance evolves,” he explained.

Understanding the bacteria that causes cholera, an acute diarrheal illness linked to infected water and foods, has global implications. The disease sickens up to 4 million people worldwide and severe cases can cause death within hours.

At the microbiological level, life can be described as belonging to one of three kingdoms — how species are described in relation to one another. Eukarya contains complex organisms like animals and plants and microorganisms such as fungi. The other two categories, bacteria and archaea, are comprised only of microorganisms. Archaea are prevalent in a range of environments, from some of the most hostile like volcanoes and permafrost. However, archaea are also common in the human microbiome and as an important part of soil ecology.

“As temperature is a major driver of biological processes, climate warming will impact various ecological communities,” Zhou said. “Based on long-term time-series data, our previous studies revealed that experimental warming leads to the divergent succession of soil bacterial and fungal communities, accelerates microbial temporal scaling, reduces the biodiversity of soil bacteria, fungi and protists, but increases bacterial network complexity and stability. However, how climate warming affects the temporal succession of the archaeal community remains elusive. Archaea are ubiquitously present in soil and are vital to soil functions, e.g., nitrification and methanogenesis.”

Using a long-term multifactor experimental field site at OU’s Kessler Atmospheric and Ecological Field Station, the researchers showed that experimental warming of a tallgrass prairie ecosystem significantly altered the community structure of soil archaea and reduced their taxonomic and phylogenetic diversity. In contrast to the researchers’ previous observations in bacteria and fungi, their finds show that climate warming leads to convergent succession of the soil archaeal community, suggesting archaeal community structures would become more predictable in a warmer world.

Because contrasting societal views have created an approach that simultaneously manages horses on the range as wildlife, livestock and pets, current government programs are incapable of succeeding, the researchers argue in the article that appears in the journal BioScience.

“For the federal government to sustain healthy populations, ecosystem health and fiscal responsibility, lawmakers must properly define how feral equids should be labeled,” the scientists wrote. “Each label (wild, livestock, pet) has validity, and management plans can be implemented to optimize equid populations with other land uses. Furthermore, providing a clear definition of feral equids will determine the legal tools that can be applied for their management.”

The lead author of the paper is Jacob Hennig, a former UW Ph.D. student who is now a postdoctoral researcher at Oklahoma State. Hennig’s advisers at UW — Professor Jeff Beck and Associate Professor Derek Scasta, both in the Department of Ecosystem Science and Management — are co-authors of the paper. So are Oklahoma State Professor Sam Fuhlendorf and Assistant Professor Courtney Duchardt, who is a former UW Ph.D. student; Colorado State University research scientist Saeideh Esmaeili, also a former UW Ph.D. student; and Tolani Francisco, of Native Healing LLC in New Mexico.

The researchers note that, while the fossil record shows there were horses in North America previously, they went extinct about 10,000 years ago.

“The equids currently inhabiting North America did not coevolve there; they are descendants of livestock that underwent millennia of domestication and artificial selection,” the paper says. “Most large predators that would help limit their population growth went extinct at the end of the Pleistocene (epoch), and the Anthropocene (current epoch) has led to further predator reductions.”

Because wild horses have no natural predators, cannot be legally hunted under federal law and are no longer slaughtered as livestock in the United States, their numbers on the range have more than doubled in the last decade, the researchers say. They also note that horses removed from the range by the Bureau of Land Management (BLM) and held in government facilities and private lands have grown in number by 33 percent during that time, with the BLM spending over $550 million since 2013 supporting the captive animals.

“The BLM has increased the number of individuals removed from the wild in each of the past four years, leading to decreases in the on-range population,” the paper acknowledges. “However, the total on-range population is still approximately 50,000 individuals above the maximum (appropriate management level), and the recent moderate decrease in on-range individuals is directly correlated with an increase in the off-range population and subsequent expenditures.”

Removing wild horses from Western rangelands and placing them in long-term holding is not a solution, the researchers say. Doing so “simply exports the issue elsewhere — including the imperiled tallgrass prairie ecosystem — with unknown ecological effects,” they wrote, noting that there are now about 23,500 wild horses on private lands in Oklahoma, five times more than the number on open range in Wyoming.

Additionally, the paper contends that wild horses have a comparatively large impact on the range, as they consume more forage and water than ruminants such as cattle, per capita.

The scientists credit the BLM for basing recent management on science, including better population estimates of wild horses and deploying measures to keep them from reproducing. But there are too many animals on the range for this approach to work.

“Although the BLM has admirably increased fertility control research and application, if they are unable to also remove tens of thousands of equids, this process is doomed to be a Sisyphean task,” the researchers wrote.

The federal Wild and Free-Roaming Horses and Burros Act of 1971 essentially calls for wild horses to freely roam like wild animals, but they are treated differently from wild animals because the act prohibits hunting. At the same time, the BLM’s practice of gathering and removing wild horses from the range “more closely resemble livestock operations than wildlife management, whereas adoption programs, sales restrictions and the abolition of slaughter have resulted in feral equids effectively serving as society’s pets,” the paper says.

Choosing one of the labels — wild, livestock or pets — offers the best hope for the federal government to succeed in wild horse management, the scientists wrote.

“As a wild species that lacks sufficient predation to keep most populations in check, a hunting or culling program, like those for other wild ungulates, could slow their population growth,” the paper says. “As livestock, gathers and removals that lead to sale or slaughter would limit growth and give the animals the monetary value they currently lack. As pets, simultaneously conducting large-scale removals and administering fertility control, including permanent sterilization (and potentially euthanasia), could reduce population sizes and slow growth.”

The researchers’ conclusion?

“The current state of feral horse and burro management in the United States is unsustainable and will continue to be a painful resource sink without fundamental changes to the law. We recommend that the U.S. federal government should officially declare the status of feral equids as either wild, livestock or pets and should provide the BLM and (U.S. Forest Service) the legal latitude and funding to develop and implement respective management options.”

The research team from SLAC, Stanford and other institutions started with what is now a fairly standard technique: They zapped a mixture of ferricyanide and water with an ultraviolet laser and bright X-rays generated by the Linac Coherent Light Source (LCLS) X-ray free-electron laser. The ultraviolet light kicked the molecule into an excited state while the X-rays probed the sample’s atoms, revealing features of ferricyanide’s atomic and electronic structure and motion.

What was different this time is how the researchers extracted information from the X-ray data. Instead of studying only one spectroscopic region, known as the Kβ main emission line, the team captured and analyzed a second emission region, called valence-to-core, which has been significantly more challenging to measure on ultrafast timescales. Combining information from both regions enabled the team to obtain a detailed picture of the ferricyanide molecule as it evolved into a key transitional state.

The team showed that ferricyanide enters an intermediate, excited state for about 0.3 picoseconds — or less than a trillionth of a second — after being hit with a UV laser. The valence-to-core readings then revealed that following this short-lived, excited period, ferricyanide loses one of its molecular cyanide “arms,” called a ligand. Ferricyanide then either fills this missing joint with the same carbon-based ligand or, less likely, a water molecule.

“This ligand exchange is a basic chemical reaction that was thought to occur in ferricyanide, but there was no direct experimental evidence of the individual steps in this process,” SLAC scientist and first author Marco Reinhard said. “With only a Kβ main emission line analysis approach, we wouldn’t really be able to see what the molecule looks like when it is changing from one state to the next; we’d only obtain a clear picture of the beginning of the process.”

“You want to be able to replicate what nature does to improve technology and increase our foundational scientific knowledge,” SLAC senior scientist Dimosthenis Sokaras said. “And in order to better replicate natural processes, you have to know all of the steps, from the most obvious to those that happen in the dark, so to speak.”

In the future, the research team wants to study more complex molecules, such as hemeproteins, which transport and store oxygen in red blood cells — but which can be tricky to study because scientists do not understand all the intermediate steps of their reactions, Sokaras said.

The research team refined their X-ray spectroscopy technique at SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL) and the LCLS over many years, and then combined all this expertise at the LCLS’s X-ray Correlation Spectroscopy (XCS) instrument to capture the molecular structural changes of ferricyanide. The team published their results today in Nature Communications.

“We leveraged both SSRL and LCLS to complete the experiment. We couldn’t have finished developing our method without access to both facilities and our longstanding collaboration together,” said Roberto Alonso-Mori, SLAC lead scientist. “For years, we have been developing these methods at these two X-ray sources, and now we plan to use them to uncover previously inaccessible secrets of chemical reactions.”

240 study participants viewed an interactive Monet Water Lily art exhibition from Google Arts and Culture. By filling out a questionnaire, they provided information about their state of mind, how much pleasure they felt when looking at the pictures, and how meaningful they considered the experience to be. The results showed significant improvements in mood and anxiety after just a few minutes of viewing.

“Online art viewing is an untapped source of support for well-being that can be consumed as bite-sized bits of meaning-making and pleasure,” says MacKenzie Trupp, first author from the University of Vienna.

The study also found that some participants were more receptive to art than others and were able to benefit more. This advantage could be predicted using a metric called “aesthetic responsiveness.”

“Aesthetic responsiveness describes how people react to diverse aesthetic stimuli, like art and nature. The results showed that individuals with high levels of art and aesthetic responsiveness benefit more from online art viewing due to having more pleasurable and meaningful art experiences,” explains Edward A. Vessel of MPIEA, developer of the Aesthetic Responsiveness Assessment (AReA).

The findings of this study are particularly interesting for people who are unable to visit museums in person, such as those with health problems. Furthermore, the results suggest that interactive art exhibitions and similar online experiences should be designed with an awareness of individual differences in aesthetic responsiveness. The study thus expands insight into the benefits and limitations of art in digital media and points the way for increasing the wellness potential of online art.