The results, reported in the Proceedings of the National Academy of Sciences, suggest a previously unexplored avenue for achieving higher-temperature superconductivity, which offers a number of potential benefits to energy generators and consumers.

Electric current can move through superconducting materials without resistance, while traditional transmission materials lose as much as 10 percent of the energy between the generating source and the end user. Finding superconductors that work at or near room temperature — current superconductors require the use of a cooling agent — could allow utility companies to provide more electricity without increasing the amount of fuel required, reducing their carbon footprint and improving the reliability and efficiency of the power grid.

The transition temperature increased exponentially for the materials tested using the new method, although it remained below room temperature. But Paul C.W. Chu, chief scientist at the Texas Center for Superconductivity at UH (TcSUH) and corresponding author for the paper, said the method offers an entirely new way to approach the problem of finding superconductors that work at a higher temperature.

Chu, a physicist and TLL Temple Chair of Science at UH, said the current record for a stable high-temperature superconductor, set by his group in 1994, is 164 Kelvin, or about -164 Fahrenheit. That superconductor is mercury-based; the bismuth materials tested for the new work are less toxic, and unexpectedly reach a transition temperature above 90 Kelvin, or about -297 Fahrenheit, after first predicted drop to 70 Kelvin.

The work takes aim at the well-established principle that the transition temperature of a superconductor can be predicted through the understanding of the relationship between that temperature and doping — a method of changing the material by introducing small amounts of an element that can change its electrical properties — or between that temperature and physical pressure. The principle holds that the transition temperature increases up to a certain point and then begins to drop, even if the doping or pressure continues to increase.

Liangzi Deng, a researcher at TcSUH working with Chu and first author on the paper, came up with the idea of increasing pressure beyond the levels previously explored to see whether the superconducting transition temperature would increase again after dropping.

It worked. “This really shows a new way to raise the superconducting transition temperature,” he said. The higher pressure changed the Fermi surface of the tested compounds, and Deng said the researchers believe the pressure changes the electronic structure of the material.

The superconductor samples they tested are less than one-tenth of a millimeter wide; the researchers said it was challenging to detect the superconducting signal of such a small sample from magnetization measurements, the most definitive test for superconductivity. Over the past few years, Deng and his colleagues in Chu’s lab developed an ultrasensitive magnetization measurement technique that allows them to detect an extremely small magnetic signal from a superconducting sample under pressure above 50 gigapascals.

Deng noted that in these tests, the researchers did not observe a saturation point — that is, the transition temperature will continue to rise as the pressure increases.

They tested different bismuth compounds known to have superconducting properties and found the new method substantially raised the transition temperature of each. The researchers said it’s not clear whether the technique would work on all superconductors, although the fact that it worked on three different formulations offers promise.

But boosting superconductivity through high pressure isn’t practical for real-world applications. The next step, Chu said, will be to find a way to achieve the same effect with chemical doping and without pressure.

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Materials provided by University of Houston. Original written by Jeannie Kever. Note: Content may be edited for style and length.

“The record represents the largest individual within the genus Gyrinophilus, the largest body size of any cave-obligate salamander and the largest salamander within the Plethodontidae family in the United States,” said Nicholas Gladstone, a graduate student in UT’s Department of Earth and Planetary Sciences, who made the discovery.

The find is making scientists reexamine growth limits of these animals in harsh environments and how hospitable underground environments really are.

Salamanders can be found in a variety of habitats across Tennessee. Some species have adapted to live in cave environments, which are thought of as extreme and inhospitable ecosystems due to the absence of light and limited resources.

Salamanders are one of only two vertebrate animal groups to have successfully colonized caves. The other is fish, said Gladstone.

The record-breaking specimen had some damage to the tail, leading researchers to believe that it was once nearly 10 inches long.

The Berry Cave Salamander can be found in only 10 sites in eastern Tennessee, and in 2003 it was placed on the US Fish and Wildlife Service’s Candidate Species List for federal protection.

“This research will hopefully motivate additional conservation efforts for this rare and vulnerable species,” said Gladstone.

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The team has turned graphene oxide (GO) into a soft, moldable and kneadable play dough that can be shaped and reshaped into free-standing, three-dimensional structures.

Called “GO dough,” the product might be fun to play with it, but it’s more than a toy. The malleable material solves several long-standing — and sometimes explosive — problems in the graphene manufacturing industry.

“Currently graphene oxide is stored as dry solids or powders, which are prone to combustion,” said Jiaxing Huang, who led the study. “Or they have to be turned into dilute dispersions, which multiply the material’s mass by hundreds or thousands.”

Huang recounted his most recent shipment of 5 kilograms of graphene oxide, which was dispersed in 500 liters of liquid. “It had to be delivered in a truck,” he said. “The same amount of graphene oxide in dough form would weigh about 10 kilograms, and I could carry it myself.”

The research was published today (Jan. 24) in the journal Nature Communications. Huang is a professor of materials science and engineering in Northwestern’s McCormick School of Engineering.

Graphene oxide, which is a product of graphite oxidation, is often used to make graphene, a single-atom-layer thick sheet of carbon that is remarkably strong, lightweight and has potential for applications in electronics and energy storage.

Just add water

Huang’s team made GO dough by adding an ultra-high concentration of graphene oxide to water. If the team had used binding additives, they would have had to further process the material to remove these additives in order to return graphene oxide to its pure form.

“Adding binders such as plastics could turn anything into a dough state,” Huang said. “But these additives often significantly alter the material’s properties.”

After being shaped into structures, the dough can be converted into dense solids that are electrically conductive, chemically stable and mechanically hard. Or, more water can be added to the dough to transform it into a high-quality GO dispersion on demand. The dough can also be processed further to make bulk graphene oxide and graphene materials of different forms with tunable microstructures. Huang hopes that GO dough’s ease of use could help graphene meet its much-anticipated potential as a super material.

“My dream is to turn graphene-based sheets into a widely accessible, readily usable engineering material, just like plastic, glass and steel,” Huang said. “I hope GO dough can help inspire new uses of graphene-based materials, just like how play dough can inspire young children’s imagination and creativity.”

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Now a Northwestern University team has developed a new tool that images blood flow through these tiny vessels, giving insight into this central portion of the human circulatory system. Called spectral contrast optical coherence tomography angiography (SC-OCTA), the 3D-imaging technique can detect subtle changes in capillary organization for early diagnosis of disease.

“There has been a progressive push to image smaller and smaller blood vessels and provide more comprehensive, functional information,” said Vadim Backman, who led the study. “Now we can see even the smallest capillaries and measure blood flow, oxygenation and metabolic rate.”

The paper was published last week in the journal Light: Science and Applications. Backman is the Walter Dill Scott Professor of Biomedical Engineering in Northwestern’s McCormick School of Engineering.

Researchers and physicians have long been able to see inside major veins and arteries with Doppler ultrasound, which uses high-frequency sound waves to measure blood flow. But this insight does not give a full picture of the circulatory system. Unlike veins and arteries, capillaries are responsible for oxygen exchange, or delivering oxygen to organs and tissues throughout the body while shuttling carbon dioxide away. Low blood oxygen can cause mild problems such as headaches to severe issues such as heart failure.

“You can have great blood flow through arteries and still have absolutely no blood sending oxygen to tissues if you don’t have the right microvasculature,” Backman said. “Oxygen exchange is important to everything the body does. But many questions about what happens in microvasculature have gone unanswered because there was no tool to study them. Now we can tackle that.”

“SC-OCTA is a valuable diagnostic tool,” added James Winkelmann, a graduate student in Backman’s laboratory and the study’s first author. “We can now detect alterations to capillary organization, which is evident in a variety of conditions ranging from cancer to cardiovascular disease. Detecting these diseases earlier has the potential to save lives.”

Researchers have had difficulties peering inside capillaries because of the vessels’ microscopic size. A single capillary is a mere 5-10 microns in diameter — so small that red blood cells must flow through in single file.

SC-OCTA works by combining spectroscopy, which looks at the various visible light wavelengths, or color spectra, with conventional optical coherence tomography (OCT), which is similar to ultrasound except uses light waves instead of sound waves. Like a radar, OCT pinpoints the tissue of interest, and then spectroscopy characterizes it.

SC-OCTA has many advantages over traditional imaging: it does not rely on injected dyes for contrast or harmful radiation. Many types of imaging also only work if the area of interest is moving (for example, ultrasound can only image blood when it is flowing) or completely still. SC-OCTA can take a clear picture of both. This enables it to image stagnant blood or moving organs, such as a beating heart.

“It can measure blood flowing regardless of how fast it goes, so motion is not a problem,” Backman said.

“SC-OCTA’s unique ability to image non-flowing blood could also become a valuable tool for the booming field of organoids, which studies how organs develop and respond to disease,” Winkelmann said. “I am excited to start exploring all the applications.”

The new technology’s only limitation is that it cannot image deeper than 1 millimeter. This might seem shallow compared to ultrasound, which can see several centimeters below the surface. Backman said this can be remedied by putting the tool on the end of an endoscopic probe. By inserting it into the body, the tool can image organs up-close. That is something that his laboratory is working on now.

Thought so.

Help could be on the way from one of the most common, yet poorly understand, forms of power generation: static electricity.

“Nearly everyone has zapped their finger on a doorknob or seen child’s hair stick to a balloon. To incorporate this energy into our electronics, we must better understand the driving forces behind it,” says James Chen, PhD, assistant professor in the Department of Mechanical and Aerospace Engineering in the School of Engineering and Applied Sciences at the University at Buffalo.

Chen is a co-author of a study in the December issue of the Journal of Electrostatics that suggests the cause of this hair-raising phenomenon is tiny structural changes that occur at the surface of materials when they come into contact with each other.

The finding could ultimately help technology companies create more sustainable and longer-lasting power sources for small electronic devices.

Supported by a $400,000 National Science Foundation grant, Chen and Zayd Leseman, PhD, associate professor of mechanical and nuclear engineering at Kansas State University, are conducting research on the triboelectric effect, a phenomenon wherein one material becomes electrically charged after it contacts a different material through friction.

The triboelectric effect has been known since ancient times, but the tools for understanding and applying it have only become available recently due to the advent of nanotechnology.

“The idea our study presents directly answers this ancient mystery, and it has the potential to unify the existing theory. The numerical results are consistent with the published experimental observations,” says Chen.

The research Chen and Leseman conduct is a mix of disciplines, including contact mechanics, solid mechanics, materials science, electrical engineering and manufacturing. With computer models and physical experiments, they are engineering triboelectric nanogenerators (TENGs), which are capable of controlling and harvesting static electricity.

“The friction between your fingers and your smartphone screen. The friction between your wrist and smartwatch. Even the friction between your shoe and the ground. These are great potential sources of energy that we can to tap into,” Chen says. “Ultimately, this research can increase our economic security and help society by reducing our need for conventional sources of power.”

As part of the grant, Chen has worked with UB undergraduate students, as well as high school students at the Health Sciences Charter School in Buffalo, to promote science, technology, engineering and math (STEM) education.

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Fatal listeriosis in Lower Austria

The study was motivated by an episode of fatal listeriosis in fattening pigs in a pig farm in Lower Austria with an integrated fattening unit with space for 450 pigs. Clinical symptoms such as anorexia, bloody diarrhea and an increased body temperature up to 40°C were observed in about 10% of the fattening pigs, mostly in well-fed animals with a bodyweight of 40-100 kg. In total, 35 fattening pigs died in a period of about 3 weeks.

A real crime thriller: evidence from DNA fingerprinting

Two fattening pigs with clinical symptoms as well as fed maize silage samples were investigated for further diagnostics. Molecular biological characterization isolated identical L. monocytogenes strains from samples taken from the pigs and in the maize silage. Additionally, a high content of deoxynivalenol was found in the maize silage. Deoxynivalenol is a mycotoxin found above all as a metabolic product in affected grains with potentially negative effects for the immune system. “The feeding of maize silage contaminated by listeria, which survive under poor ensilaging conditions, was the most likely source of infection of the fattening pigs,” says first author Heiko Stein.

Ensilaging under anaerobic conditions provides reliable protection

The researchers were able to show with their study that L. monocytogenes can cause clinical disease in fattening pigs that may be the result of immunosuppression due to high deoxynivalenol exposure. Stein therefore formulates the following appeal: “When feeding silage, it is important that all ensilaging procedures occur under appropriate anaerobic conditions to guarantee suppression of listerial growth.”

Important new insights for food safety

Listeria are rod-shaped bacteria that naturally occur in many different places. Most are harmless for people. The species L. monocytogenes, however, is anything but harmless for humans and animals. An infection caused by these bacteria can result in serious diarrhea and encephalitis in humans and may even be fatal.

It is known from cattle and sheep that feeding silage of poor quality can lead to L. monocytogenes transmission causing encephalitis or bloody diarrhea. In the scientific literature, however, only a few older case reports have dealt with L. monocytogenes transmission in pig herds despite the fact that L. monocytogenes contamination of pork products is of great concern for public health.

“Whenever bloody diarrhea combined with increased mortality occurs in fattening pigs, L. monocytogenes should be part of the list of differential diagnoses, especially if silage is part of feeding. Since in our case therapeutic and prophylactic measures led to a fast recovery of diseased animals, antimicrobial therapy is indicated as soon as possible to avoid further shedding of L. monocytogenes via faeces and to prevent additional fatal cases,” says Stein in conclusion.

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“Glucocorticoids such as cortisone have been used to treat inflammatory diseases such as asthma or rheumatism for many decades, and they are the most commonly prescribed anti-inflammatory drugs,” explains Prof. Henriette Uhlenhaut, Group Leader at the Institute for Diabetes and Obesity (IDO) at the Helmholtz Zentrum München and the Gene Center of the LMU. “They are also frequently used in autoimmune diseases, organ transplantations and cancer. It is estimated that between one and three percent of the Western population are currently receiving these drugs — which corresponds to more than one million Germans alone.”

However, although glucocorticoids are prescribed for a wide range of conditions, their use is limited by the various side effects — including unwanted metabolic effects — that can occur during treatment. Once the glucocorticoids bind to their receptor inside the cell, the receptor starts switching numerous genes on and off. “These include various metabolic genes, which can consequently cause so-called steroid diabetes,” Henriette Uhlenhaut explains.

In the current study, her team — together with colleagues from the Max Delbrück Center for Molecular Medicine in Berlin, the Salk Institute in San Diego and the University of Freiburg — set out to identify the exact sequence of events that occurs once the steroids bind their receptor.

“What struck us most was the E47 transcription factor, which — along with the glucocorticoid receptor — is responsible for the changes in gene expression, particularly in liver cells,” explains Charlotte Hemmer, a doctoral candidate at the IDO and first author of the current study. “We were able to identify the underlying pathway by conducting genome-wide analyses and genetic studies.”

In order to corroborate their findings, the scientists then proceeded to examine a preclinical model lacking the E47 gene. “The loss of E47 actually protected against the negative impact of glucocorticoids, while an intact E47 gene led to metabolic changes such as high blood sugar, elevated blood fat levels or a fatty liver as a response to steroid treatment,” Charlotte Hemmer adds.

Since the components of the newly discovered mechanism are also conserved in humans, Henriette Uhlenhaut and her team, along with their clinical cooperation partners, would now like to find out whether their results can be translated to human studies. “If this is the case, it could open up new opportunities for therapeutic intervention and the use of safer immuno-suppressants in order to combat the side effects of steroid therapy.”

The study identified microplastic fibers, along with a variety of medicines and household contaminants, in two aquifer systems in Illinois. The findings are published in the journal Groundwater.

“Plastic in the environment breaks down into microscopic particles that can end up in the guts and gills of marine life, exposing the animals to chemicals in the plastic,” said John Scott, a researcher at the Illinois Sustainable Technology Center and study co-author. “As the plastics break down, they act like sponges that soak up contaminants and microbes and can ultimately work their way into our food supply.”

Groundwater flows through the cracks and voids in limestone, sometimes carrying sewage and runoff from roads, landfills and agricultural areas into the aquifers below, Scott said.

The researchers collected 17 groundwater samples from wells and springs — 11 from a highly fractured limestone aquifer near the St. Louis metropolitan area and six from an aquifer containing much smaller fractures in rural northwestern Illinois.

All but one of the 17 samples contained microplastic particles, with a maximum concentration of 15.2 particles per liter from a spring in the St. Louis area, the study reports. However, deciphering what that concentration means is a challenge, Scott said. There are no published risk assessment studies or regulations.

The researchers did find, however, that concentrations from their field area are comparable to those of surface water concentrations found in the rivers and streams in the Chicago area, said Samuel V. Panno, an Illinois State Geological Survey researcher and lead author of the study.

“The research on this topic is at a very early stage, so I am not convinced we have a frame of reference to state expectations or bounds on what is considered low or high levels,” said Tim Hoellein, a biology professor at Loyola University Chicago and study co-author. “Our questions are still basic — how much is there and where is it coming from?”

The researchers identified a variety of household and personal health contaminants along with the microplastics, a hint that the fibers may have originated from household septic systems.

“Imagine how many thousands of polyester fibers find their way into a septic system from just doing a load of laundry,” Scott said. “Then consider the potential for those fluids to leak into the groundwater supply, especially in these types of aquifers where surface water interacts so readily with groundwater.”

There is still a monumental amount of work to be done on this subject, Scott said. He anticipates that microplastic contamination in both surface water and groundwater will be a problem for years to come.

“Even if we quit plastics cold turkey today, we will still deal with this issue for years because plastic never really goes away,” Scott said. “It is estimated that 6.3 billion metric tons of plastic waste have been produced since the 1940s, and 79 percent of that is now in landfills or the natural environment. To me, it is such a weird concept that these materials are intended for single use, yet they are designed to last forever.”

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Materials provided by University of Illinois at Urbana-Champaign. Original written by Lois Yoksoulian. Note: Content may be edited for style and length.