. Scientific Frontline

Wednesday, March 15, 2023

For the first time, controlling the degree of twist in nanostructured particles

An array of different growth conditions, spanning from left-handed twists made with only left-handed cystine to flat pancakes made with a 50-50 mix to right-handed twists made only with right-handed cystine. The ability to control the degree of twist in a curling, nanostructured material could be a useful new tool in chemistry and machine vision.
Image Credit: Prashant Kumar, Kotov Lab, University of Michigan.

Being able to decide not only whether a micron-scale particle twists but also how much could open new avenues for machine vision and more

Micron-sized “bow ties,” self-assembled from nanoparticles, form a variety of different curling shapes that can be precisely controlled, a research team led by the University of Michigan has shown.

The development opens the way for easily producing materials that interact with twisted light, providing new tools for machine vision and producing medicines.

While biology is full of twisted structures like DNA, known as chiral structures, the degree of twist is locked in—trying to change it breaks the structure. Now, researchers can engineer the degree of twist.

Such materials could enable robots to accurately navigate complex human environments. Twisted structures would encode information in the shapes of the light waves that reflect from the surface, rather than in the 2D arrangement of symbols that comprise most human-read signs. This would take advantage of an aspect of light that humans can barely sense, known as polarization. The twisted nanostructures preferentially reflect certain kinds of circularly polarized light, a shape that twists as it moves through space.

New Fossil Analysis Reveals Dinosaur with Record-Holding 15-Meter-Long Neck

 A rendering of the sauropod known as Mamenchisaurus sinocanadorum, which had a 15-meter-long neck, about 10 feet longer than a typical school bus.
Illustration Credit: Júlia d'Oliveira

With their long necks and formidable bodies, sauropod dinosaurs have captured people’s imaginations since the first relatively complete sauropod fossils were discovered in the United States in the late 1800s. Now an international team led by Stony Brook University paleontologist Andrew J. Moore, PhD, has revealed that a Late Jurassic Chinese sauropod known as Mamenchisaurus sinocanadorum sported a 15-meter-long neck. A new analysis of this dinosaur, published in the Journal of Systematic Paleontology, provides fresh insights on the evolution of the iconic sauropod body.

For sauropods, the long neck was the anatomical key to achieving a large body size. To power such a large body, sauropods had to be efficient at gathering foodstuffs, and that's what a long neck was built for. A sauropod could plant itself in one spot and hoover up surrounding vegetation, conserving energy while taking in tons of food. Having a long neck probably also allowed enormous sauropods to shed excess body heat by increasing their surface area, much like the ears of elephants. This way of life – long neck-fueled, quadrupedal gigantism – is not one that is available to mammals or any other form of life today. The sauropod lifestyle was exceptionally successful: their lineage appeared early in dinosaur evolutionary history and persisted until the final days of the Mesozoic, when an asteroid wiped out all dinosaurs (except birds).

Game-changing high-performance semiconductor material could help slash heat emissions

WVU researchers Sergio Andres Paredes Navia, Cesar Octavio Romo de la Cruz, Liang Liang and Ellena Gemmen use an electron microscope to study the nanostructure of a new oxide ceramic material with the potential to make thermoelectric generators efficient enough to capture a significant portion of the waste heat that industrial systems like power plants emit.
Photo Credit: Courtesy of West Virginia University

Researchers at West Virginia University have engineered a material with the potential to dramatically cut the amount of heat power plants release into the atmosphere.

A team led by Xueyan Song, professor and George B. Berry Chair of Engineering at the Benjamin M. Statler College of Engineering and Mineral Resources, has created an oxide ceramic material that solves a longstanding efficiency problem plaguing thermoelectric generators. Those devices can generate electricity from heat, including power plant heat emissions, which contribute to global warming.

The breakthrough oxide ceramic Song’s team produced “achieved a record-high performance that had been deemed impossible,” she said. “We demonstrated the best thermoelectric oxide ceramics reported in the field worldwide over the past 20 years, and the results open up new research directions that could further increase performance.”

Oxide ceramics are from the same family as materials like pottery, porcelain, clay bricks, cement and silicon, but contain various metallic elements. They’re hard, resistant to heat and corrosion, and well-suited for high-temperature applications in air. They can serve as the material for thermoelectric generator components.

Bypassing antibiotic resistance with a combination of drugs

A confocal microscopy image of macrophages treated with MTX (cyan) that have eaten bacteria (magenta)
Image Credit: © Singapore-MIT Alliance for Research and Technology (SMART)

By combining an antibiotic with an anti-cancer agent, an international team has developed a treatment capable of circumventing the antibiotic resistance of the bacterium Enterococcus faecalis.

Antibiotic resistance is one of the world’s most pressing health challenges: in 2019, nearly 5 million people died from an infection associated with or attributed to antibiotic resistance. A research consortium involving the Singapore-MIT Alliance for Research and Technology (SMART), the Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University (NTU), the Massachusetts Institute of Technology (MIT) and the University of Geneva (UNIGE) has tackled the potentially deadly Enterococcus faecalis bacterium, most strains of which have developed resistance to common antibiotics. The scientists have developed an innovative strategy that consists of adding mitoxantrone, an anti-cancer agent, to vancomycin, the main antibiotic used in this context. The combination of these two drugs targets simultaneously the bacteria and the human immune system, and circumvents resistance. These promising results can be read in the journal Science Advances.

Scientists have new tool to estimate how much water might be hidden beneath a planet’s surface

Exoplanets similar to Earth, artist concept.
Image Credit: NASA

Scientists from the University of Cambridge now have a way to estimate how much water a rocky planet can store in its subterranean reservoirs. It is thought that this water, which is locked into the structure of minerals deep down, might help a planet recover from its initial fiery birth.

The researchers developed a model that can predict the proportion of water-rich minerals inside a planet. These minerals act like a sponge, soaking up water which can later return to the surface and replenish oceans. Their results could help us understand how planets can become habitable following intense heat and radiation during their early years.

Planets orbiting M-type red dwarf stars — the most common star in the galaxy — are thought to be one of the best places to look for alien life. But these stars have particularly tempestuous adolescent years — releasing intense bursts of radiation that blast nearby planets and bake off their surface water.

Immune cell gives possible explanation for sex differences in pancreatic cancer

Left to Right: Fei He Photo Credit: Yifei Chen | Dhifaf Sarhan. Photo Credit: Stefan Zimmerman

Immunotherapy is an effective form of therapy for different types of cancer. However, for pancreatic cancer, its effect is limited and differs between men and women. Researchers at Karolinska Institutet have now found a possible explanation for this sex difference. The study, which is published in Cancer Research, reveals the presence of an immune cell in women with pancreatic cancer that obstructs the body’s immune response. The results can pave the way for a more sex-specific treatment.

“More and more evidence is coming in that male and female hormones affect our immune system, but much remains to be done before sex can be included as a self-evident biological factor in medical research and therapy,” says the paper’s first author Fei He, former visiting researcher at the Department of Laboratory Medicine, Karolinska Institutet. “Our results provide new perspectives that can have high impact on the treatment of cancer.”

In recent years, immunotherapy, which stimulates the immune system to attack cancer cells, has contributed significantly to the treatment of different kinds of cancer, such as melanoma and lung, kidney and liver cancer. However, it is much less effective against pancreatic cancer, which remains one of the deadliest kinds of cancer that leaves patients, on average, with four to six months left to live after diagnosis.

Extinction vulnerability during ancient biodiversity crises is unpredictable

Jurassic marine fossils
Photo Credit: Dr James Witt

Evidence from past extinctions cannot be used as a definitive way of predicting future biodiversity loss, scientists have found by using AI.

A team of researchers including Dr James Witts of the University of Bristol’s School of Earth Sciences and led by Dr William Foster from Hamburg University used fossils from previous mass extinctions to see if AI-generated models can accurately predict extinction vulnerability.

Despite expectations, this research found that mass extinctions could not be used to generate predictive models for other biodiversity crises, with no common cause flagged. This is because marine communities are constantly evolving and no two mass extinctions are impacting the same marine ecosystem.

Co-author Dr Witts explained: “In a time of increasing extinction risk, knowing whether we can make predictions about the vulnerabilities of different organisms to extinction is essential.”

Dr Foster continued: “The scale of environmental change currently affecting our planet is unprecedented in human history, and so the best source of evidence we have for comparable environmental change lies in the deep past, accessible via analysis of the fossil record.

A common metabolite may help treat autoimmune diseases

In mice models with adoptive transfer experimental autoimmune encephalomyelitis, treatment with itaconate (right) greatly ameliorates the effects of the disease, compared to untreated mice
Image Credit: Kuniyuki Aso, et al. Nature Communications. February 27, 2023

Researchers have revealed the modulatory effect of the anti-inflammatory metabolite itaconate on T helper and T regulatory cells, which may lead to new therapeutic approaches to treating some autoimmune diseases.

Autoimmune diseases occur when the immune system attacks its own body. There are more than eighty known types of autoimmune diseases. In many cases, autoimmune diseases can be treated by suppressing the immune system; however, a side effect of such treatment is that the patient has an increased risk of severe infectious diseases, which is a leading cause of death. Hence there is a need to establish novel therapies for autoimmune diseases to reduce the risk of infectious diseases. 

A research team led by Professor Tatsuya Atsumi, Assistant Professor Michihito Kono and graduate student Kuniyuki Aso at Hokkaido University, along with Senior Lecturer Masatoshi Kanda at Sapporo Medical University, has studied the effect of the molecule itaconate on the immune system. Their findings, which have implications for treating autoimmune disorders, were published in the journal Nature Communications.

World’s first completely roll-to-roll printable perovskite solar cell

Dr David Beynon (Left) and Dr Ershad Parvazian (Right) hold a sample of the new fully roll-to-roll (R2R) coated device.
Photo Credit: Courtesy of Swansea University

Swansea University has established a low-cost and scalable carbon ink formulation capable of unlocking, for the first time, the potential for perovskite solar cells to be manufactured at scale.

Using slot die coating in a roll-to-roll (R2R) process, academics from the SPECIFIC Innovation and Knowledge Centre at Swansea University have established a way to create “fully printable” perovskite photovoltaics (PV), a term often used but, until now, incorrect.

The team searched for an alternative to the gold electrode that is typically applied using an expensive and slow evaporation process after the device has been printed.

Dr David Beynon, Senior Research Officer at SPECIFIC, said: “The key was identifying the right solvent mix, one which dries as a film without dissolving the underlying layer.

“X-ray diffraction analysis showed carbon electrode ink is capable of this when formulated with an orthogonal solvent system.

“This innovative layer can be applied continuously and compatibly with the underlying layers at a low temperature and high speed.”

Monday, March 13, 2023

Stanford study reveals why the world's largest whales needed to be so big

Minke whales in Antarctica were studied by researchers using instrumented tags that can measure various aspects of their feeding activity.
Image Credit: Duke Marine Robotics and Remote Sensing.
This research was conducted under National Marine Fisheries Service permit #23095

Scientists studied a unique group of Antarctic minke whales and found that these gigantic mammals actually represent the smallest possible body size required for their style of feeding. The findings could inform which whale species are more vulnerable to future climate change impacts, like shifting food sources.

The largest animals to ever live owe their enormous size to feeding on the tiniest creatures in the sea, but their survival requires a minimum body size, Stanford-led research has found.

Published March 13 in Nature Ecology & Evolution, the study focuses on the “rorqual whales,” a lineage of filter feeders that includes the blue whale, the largest animal of all time. The group is characterized by a lunging maneuver where individuals engulf an enormous amount of water along with their prey, which they then strain through fringed structures at the roof of their mouth.

By examining the smallest living species in this group – the Antarctic minke whale – the authors found that individuals need to grow to at least 4.5 meters (approximately 15 feet, or weighing 1-2 tons), the length of weaned minke juveniles, in order to eat enough food to survive.

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