Electrons screen against conductivity-killer in organic semiconductors

Muhamed Duhandžić, doctoral candidate and study author, writes the equations he and Zlatan Akšamija (left) derived to describe the physics happening inside the doped polymer.
Photo Credit: Harriet Richardson/University of Utah

California’s Silicon Valley and Utah’s Silicon Slopes are named for the element most associated with semiconductors, the backbone of the computer revolution. Anything computerized or electronic depends on semiconductors, a substance with properties that conduct electrical current under certain conditions. Traditional semiconductors are made from inorganic materials—like silicon—that require vast amounts of water and energy to produce.

For years, scientists have tried to make environmentally friendly alternatives using organic materials, such as polymers. Polymers are formed by linking small molecules together to make long chains. The polymerization process avoids many of the energy-intensive steps required in traditional semiconductor manufacturing and uses far less water and fewer gasses and chemicals. They’re also cheap to make and would enable flexible electronics, wearable sensors and biocompatible devices that could be introduced inside the body. The problem is that their conductivity, while good, is not as high as their inorganic counterparts.

All electronic materials require doping, a method of infusing molecules into semiconductors to boost conductivity. Scientists use molecules, called dopants, to define the conductive parts of electrical circuits. Doping in organic materials has vexed scientists because of a lack of consistency—sometimes dopants improve conductivity while other times they make it worse.  In a new study, researchers from the University of Utah and University of Massachusetts Amherst have uncovered the physics that drive dopant and polymer interactions that explain the inconsistent conductivity issue.

The ties that bind

The soils in many iconic Australian landscapes, like the outback and deserts, are colored red by an abundant mineral known as goethite. This mineral tends to lock away trace metals over time, according to research from Washington University in St. Louis
Photo Credit: Nathan March

Trace metals are nutrient elements, like zinc, that animals and plants need in small amounts to function properly. Animals generally get trace metals in their diets or through environmental exposures, while plants take their trace minerals up from soil. If we get too little, we may experience a deficiency, but the opposite can also be true: too much of a trace metal can be toxic.

Scientists believe that up to 50% of the trace metals in soils and urban environments may be bound to the surfaces of mineral grains — rendering the trace metals essentially unavailable for consumption or exposure. Researchers at Washington University in St. Louis wondered what holds them in place.

“When minerals bind trace metals, we often assume that they act like a sponge,” said Jeffrey G. Catalano, a professor of earth, environmental and planetary sciences and the director of environmental studies in Arts & Sciences. “But sometimes, they bind trace metals and won’t let them go. That is great when they are contaminants, but bad when they are serving as micronutrients.”

In a study published in the journal Environmental Science & Technology, Catalano and Greg Ledingham, a PhD candidate in his laboratory, discovered that a common mineral called goethite — an iron-rich mineral that is abundant in soils that cover the Earth — tends to incorporate trace metals into its structure over time, binding the metals in such a way that it locks them out of circulation.

SwRI scientists find evidence of geothermal activity within icy dwarf planets

Eris and Makemake
Image Credit: Courtesy of Southwest Research Institute

A team co-led by Southwest Research Institute found evidence for hydrothermal or metamorphic activity within the icy dwarf planets Eris and Makemake, located in the Kuiper Belt. Methane detected on their surfaces has the tell-tale signs of warm or even hot geochemistry in their rocky cores, which is markedly different than the signature of methane from a comet.

“We see some interesting signs of hot times in cool places,” said SwRI’s Dr. Christopher Glein, an expert in planetary geochemistry and lead author of a paper about this discovery. “I came into this project thinking that large Kuiper Belt objects (KBOs) should have ancient surfaces populated by materials inherited from the primordial solar nebula, as their cold surfaces can preserve volatiles like methane. Instead, the James Webb Space Telescope (JWST) gave us a surprise! We found evidence pointing to thermal processes producing methane from within Eris and Makemake.”

The Kuiper Belt is a vast donut-shaped region of icy bodies beyond the orbit of Neptune at the edge of the solar system. Eris and Makemake are comparable in size to Pluto and its moon Charon. These bodies likely formed early in the history of our solar system, about 4.5 billion years ago. Far from the heat of our Sun, KBOs were believed to be cold, dead objects. Newly published work from JWST studies made the first observations of isotopic molecules on the surfaces of Eris and Makemake. These so-called isotopologues are molecules that contain atoms having a different number of neutrons. They provide data that is useful in understanding planetary evolution.

Scientists are unraveling the secrets of red and grey squirrel competition

Image Credit: Gemini Advance AI

In a first of its kind study, researchers have identified significant differences between the diversity of gut bacteria in grey squirrels compared to red squirrels which could hold the key to further understanding the ability of grey squirrels to outcompete red squirrels in the UK. 

New research, published in the Journal of Medical Microbiology, looked to understand more about the mechanisms by which grey squirrels are able to gain an advantage over red squirrels. Chris Nichols, Conservation Evidence Manager at the Woodland Trust, and co-author of the study, said:

“The more we know about grey squirrels, the more equipped we’re going to be in the future to tackle the threats they pose to red squirrels and our native trees, which is one of the biggest problems for forest conservation in the UK.”

Grey squirrels are an invasive, non-native species introduced from North America to sites in Great Britain and Ireland between 1876 to 1929. They out-compete the native red squirrels and multiply thanks to various traits including their ability to access a broader range of food sources including the bark of UK broadleaved trees. This causes significant damage to the trees, and is a behavior that, prior to this research, was not completely understood. 

Asexual Propagation of Crop Plants Gets Closer

Two varieties of the model plant thale cress: on the left a significantly larger hybrid variety, on the right the standard variety for laboratory research.
Photo Credit: Nicholas Desnoyer, UZH

When the female gametes in plants become fertilized, a signal from the sperm activates cell division, leading to the formation of new plant seeds. This activation can also be deliberately triggered without fertilization, as UZH researchers have shown. Their findings open up new avenues for the asexual propagation of crop plants.

Seeds are the end product of plant reproduction. Whether directly as food, or indirectly as animal feed, they provide around 80 percent of human calorie consumption. In the millennia since humans first settled, we have bred countless plant varieties with advantageous characteristics, such as increased yields, improved quality, resistance to pests or hardiness. Where possible, farmers use hybrid varieties, which are created by crossing two inbred lines and are more resistant and higher-yielding than normal varieties. The problem is that these desired properties are lost during propagation and, therefore, hybrid seeds have to be recreated every year.

Targeting inflammation to tackle long covid

Illustration Credit: Gerd Altmann

Overactivation of the immune system leading to circulation of inflammatory proteins around the body contributes to the development of long covid, and could be targeted to provide treatments for patients, finds new research.

Cardiff University research has uncovered biological markers that could be targeted by repurposing medication to treat long covid.

The research conducted extensive analysis of plasma samples obtained from a large cohort of healthy post-covid individuals and non-hospitalized patients with long covid. They found that the complement system – a system that plays a crucial part of the immune system, consisting of a group of proteins that work together to enhance the function of antibodies and immune cells – was commonly overactivated in those with long covid.

“The covid-19 pandemic has left a global legacy of ill health, with long covid estimated to affect up to 1.9 million people in the UK. Long covid can last for months or years after the triggering infection and is associated with diverse symptoms including brain fog, chest pain, breathlessness, fatigue, and sensory problems. The causes of this disease remain largely unknown, emerging evidence suggests an important role for chronic inflammation."
Professor Paul Morgan 'Professor of complement biology, Division of Infection and Immunity

The life of a Stone Age man has been mapped

Illustration Credit: Niels Bach
CC-BY 4.0

Researchers have mapped the life of a Stone Age man in detail. New scientific methods have revolutionized archaeology and the Swedish-Danish team of researchers at the University of Gothenburg are now able to state that “Vittrup Man”, a Stone Age man found in a bog in Denmark, travelled across a wide geographical area during his lifetime.

Vittrup Man was first discovered in 1915. His skull had been split by at least eight blows from a club and his body placed in a wetland in north Jutland. Until recently, this was all we knew about him. Researchers now know that he had travelled a long way before his death in about 3200 BCE. He must have led an interesting life.

“He comes from the north, from a relatively cold area, and it must have been a coastal area because the food he ate as a child came from the sea,” says archaeologist Karl-Göran Sjögren, a member of the research team.

Scientists help discover new treatment for many cancers

UniSA/CCB Professor Greg Goodall, part of the team that made the landmark discovery.
Photo Credit: Courtesy of University of South Australia 

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Researchers identified the specific molecular mechanism responsible for actively transporting circular RNAs (circRNAs) from the cell nucleus to the cytoplasm.
• Methodology: The study mapped the export pathway and revealed that circRNAs utilize a transport mechanism resembling that of proteins, distinct from the export routes used by other forms of RNA.
• Key Data: Circular RNA possesses a closed-loop genetic structure that renders it inherently more stable and durable in the body compared to linear mRNA, which degrades rapidly.
• Significance: Understanding this transport pathway overcomes a major limitation of current RNA technology, validating circRNA as a robust platform for more effective genetic medicines.
• Future Application: These findings enable the development of a next generation of RNA therapeutics and vaccines with increased potency and longevity for treating cancer and other diseases.
• Branch of Science: Molecular Biology, Oncology, and Pharmacology.
• Additional Detail: The discovery confirms that circRNAs are not cellular byproducts but are actively transported to the cytoplasm to perform critical biological functions.

New Algorithm Disentangles Intrinsic Brain Patterns from Sensory Inputs

Image Credit: Omid Sani, Using Generative Ai

Maryam Shanechi, Dean’s Professor of Electrical and Computer Engineering and founding director of the USC Center for Neurotechnology, and her team have developed a new machine learning method that reveals surprisingly consistent intrinsic brain patterns across different subjects by disentangling these patterns from the effect of visual inputs.

The work has been published in the Proceedings of the National Academy of Sciences (PNAS).

When performing various everyday movement behaviors, such as reaching for a book, our brain has to take in information, often in the form of visual input — for example, seeing where the book is. Our brain then has to process this information internally to coordinate the activity of our muscles and perform the movement. But how do millions of neurons in our brain perform such a task? Answering this question requires studying the neurons’ collective activity patterns, but doing so while disentangling the effect of input from the neurons’ intrinsic (aka internal) processes, whether movement-relevant or not.

That’s what Shanechi, her PhD student Parsa Vahidi, and a research associate in her lab, Omid Sani, did by developing a new machine-learning method that models neural activity while considering both movement behavior and sensory input.

Better diagnosis and treatment of cryptococcosis

Photo Credit: Courtesy of University of Cologne

Global guideline for the management of cryptococcosis, a fungal infection that can have serious health consequences, published in the journal ‘The Lancet Infectious Diseases’

A group of international mycology experts led by Professor Dr Oliver A. Cornely at the University of Cologne has jointly drafted a guideline for the diagnosis and treatment of cryptococcosis, which aims at improving infection management and thus the survival rate of patients. Cryptococcosis is a fungal infection of mainly the lungs that might lead to meningitis. The article ‘Global guideline for the diagnosis and management of cryptococcosis’ was published in the journal The Lancet Infectious Diseases.

Cryptococcosis, especially cryptococcal meningitis (CM) as the most fatal form, is responsible for a high fatality rate among patients. It is one of the most widespread invasive fungal infections in the world and is a major threat particularly to people suffering from immunodeficiencies. For example, around one million cases of cryptococcal meningoencephalitis are diagnosed worldwide every year in people with HIV alone, and more than 600,000 people die from the disease each year. Patients who have undergone a bone marrow transplant or organ transplant are also at high risk of infection. It is transmitted through the inhalation of spores from soil. Other organs are then also infected via the bloodstream. The lungs, brain, skin and bones are most frequently affected.

Compounds released by bleaching coral reefs promote bacteria

Field site in Moʻorea, French Polynesia.
Photo Credit: Milou Arts of NIOZ

On healthy reefs, corals, algae, fishes and microbes live interconnected and in balance—exchanging nutrients, resources and chemical signals. New research led by the University of Hawaiʻi at Mānoa and the Royal Netherlands Institute for Sea Research (NIOZ) revealed that when coral bleaching occurs, corals release unique organic compounds into the surrounding water that not only promote bacterial growth overall, but also promote bacteria that may further stress reefs and pose the risk for more damage.

“Our results demonstrate how the impacts of both short-term thermal stress and long-term bleaching may extend beyond coral and into the water column,” said Wesley Sparagon, co-lead author, postdoctoral researcher in the UH Mānoa College of Tropical Agriculture and Human Resources and previous doctoral student with the UH Mānoa School of Ocean and Earth Science and Technology (SOEST).

The research team, which included scientists from UH Mānoa, NIOZ, Scripps Institution of Oceanography and University of California, Santa Barbara, conducted experiments on bleached and unbleached corals gathered during a bleaching event in Moorea, French Polynesia in 2019.

“Although coral bleaching is a well-documented and increasingly widespread phenomenon in reefs across the globe, there has been relatively little research on the implications for reef water column microbiology and biogeochemistry,” said Craig Nelson, senior author on the study and professor in SOEST.

Discovery of new plant protein fold may be seed for anti-cancer drugs

The new protein fold from AhyBURP is found in the roots of the peanut plant. The protein uses copper and oxygen to form cyclic peptides. We can investigate how this chemistry occurs more thoroughly now that we know what the protein structure looks like.
Image Credit: Lisa Mydy / University of Michigan

University of Michigan researchers are celebrating their discovery of a new plant biochemistry and its unusual ability to form cyclic peptides—molecules that hold promise in pharmaceuticals as they can bind to challenging drug targets.

Cyclic peptides are an emerging and promising area of drug research.

A new study, led by U-M College of Pharmacy researchers Lisa Mydy and Roland Kersten, revealed a mechanism by which plants generate cyclic peptides.

Mydy identified the new plant protein fold and its novel chemistry, which she said had never been seen before. The protein can generate cyclic peptides, one of which holds potential as an anti-cancer drug.

“It’s extremely exciting,” said Mydy, a postdoctoral research fellow in the Department of Medicinal Chemistry. “This type of discovery doesn’t happen too often.”

A standard blood test can predict a heart attack

Researchers have proceeded from the hypothesis that several important biological processes are active during the months before a heart attack and that these could be detected using a simple blood test.
Photo Credit: Fernando Zhiminaicela

Using the results of a standard blood test and an online tool, you can find out if you are at increased risk of having a heart attack within six months. The tool has been developed by a research group at Uppsala University in the hope of increasing patients’ motivation to change their lifestyle.

Heart attacks are the most common cause of death in the world and are increasing globally. Many high-risk people are not identified or do not take their preventive treatment.

Now researchers led by Professor Johan Sundström at Uppsala University have found that heart attacks can be predicted with a standard blood test.

The problem, according to the researchers, is that risk factors have previously been verified in studies involving five to ten years of follow-up, where only factors that are stable over time can be identified.

“However, we know that the time just before a heart attack is very dynamic. For example, the risk of a heart attack doubles during the month after a divorce, and the risk of a fatal heart event is five times as high during the week after a cancer diagnosis,” says Sundström, who is a cardiologist and professor of epidemiology at Uppsala University.

Fundamental Equation for Superconducting Quantum Bits Revised

Cryogenic microwave setup used for quantum device measurements.
Photo Credit: Qinu GmbH

Quantum bits can be described more precisely with the help of newly 

Physicists from Forschungszentrum Jülich and the Karlsruhe Institute of Technology have uncovered that Josephson tunnel junctions – the fundamental building blocks of superconducting quantum computers – are more complex than previously thought. Just like overtones in a musical instrument, harmonics are superimposed on the fundamental mode. As a consequence, corrections may lead to quantum bits that are 2 to 7 times more stable. The researchers support their findings with experimental evidence from multiple laboratories across the globe, including the University of Cologne, Ecole Normale Supérieure in Paris, and IBM Quantum in New York.

It all started in 2019, when Dr. Dennis Willsch and Dennis Rieger – two PhD students from FZJ and KIT at the time and joint first authors of the paper – were having a hard time understanding their experiments using the standard model for Josephson tunnel junctions. This model had won Brian Josephson the Nobel Prize in Physics in 1973. Excited to get to the bottom of this, the team led by Professor Ioan Pop scrutinized further data from the Ecole Normale Supérieure in Paris and a 27-qubit device at IBM Quantum in New York, as well as data from previously published experiments. Independently, researchers from the University of Cologne were observing similar deviations of their data from the standard model.

Red nets signal “stop” to insect pests, reduce need for insecticides

Field test in Kyoto, Japan. The type of Welsh onions used in the experiment were a variety called Kujo leek, or Kujo negi in Japanese. These onions are a traditional vegetable of the Kyoto region and a staple part of local cooking.
Photo Credit: © 2024 Tokumaru et al./Scientific Reports

Red nets are better at keeping away a common agricultural insect pest than typical black or white nets, according to a new study. Researchers experimented with the effect of red, white, black and combination-colored nets on deterring onion thrips from eating Kujo leeks, also called Welsh onions. In both lab and field tests, red nets were significantly better at deterring the insect than other colors. Also, in field tests, onion crops which were either partially or fully covered by red netting required 25-50% less insecticide than was needed for a totally uncovered field. Changing agricultural nets from black or white to red could help reduce pesticide use and the related negative impact it can have on the environment, while supporting more sustainable and effective agricultural practices.

Insect pests can be a nightmare for any gardener. No sooner do fresh buds appear than they are covered in aphids, beetles and other bugs looking for a tasty snack. While synthetic insecticides are widely used to control pests in gardens and on agricultural crops, many are known to cause damage to the natural environment by leaching into the soil and water supplies, and poisoning plants, wildlife and harmless insects. Some pests are also becoming resistant to the chemicals, so farmers are running out of options for what to use and needing to apply more often.