. Scientific Frontline

Monday, August 1, 2022

Study finds nickelate superconductors are intrinsically magnetic

A muon, center, spins like a top within the atomic lattice of a thin film of superconducting nickelate. These elementary particles can sense the magnetic field created by the spins of electrons up to a billionth of a meter away. By embedding muons in four nickelate compounds at the Paul Scherrer Institute in Switzerland, researchers at SLAC and Stanford discovered that the nickelates they tested host magnetic excitations whether they’re in their superconducting states or not – another clue in the long quest to understand how unconventional superconductors can conduct electric current with no loss.
 Credit: Jennifer Fowlie/SLAC National Accelerator Laboratory

Electrons find each other repulsive. Nothing personal – it’s just that their negative charges repel each other. So, getting them to pair up and travel together, like they do in superconducting materials, requires a little nudge.

In old-school superconductors, which were discovered in 1911 and conduct electric current with no resistance, but only at extremely cold temperatures, the nudge comes from vibrations in the material’s atomic lattice.

But in newer, “unconventional” superconductors – which are especially exciting because of their potential to operate at close to room temperature for things like zero-loss power transmission – no one knows for sure what the nudge is, although researchers think it might involve stripes of electric charge, waves of flip-flopping electron spins that create magnetic excitations, or some combination of things.

In the hope of learning more by looking at the problem from a slightly different angle, researchers at Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory synthesized another unconventional superconductor family – the nickel oxides, or nickelates. Since then, they’ve spent three years investigating the nickelates’ properties and comparing them to one of the most famous unconventional superconductors, copper oxides or cuprates.

Super-earth skimming habitable zone of red dwarf

 The green region represents the habitable zone where liquid water can exist on the planetary surface. The planetary orbit is shown as a blue line. Ross 508 b skims the inner edge of the habitable zone (solid line), possibly crossing into the habitable zone for part of the orbit (dashed line).
Credit: Astrobiology Center

A super-Earth planet has been found near the habitable zone of a red dwarf star only 37 light-years from the Earth. This is the first discovery by a new instrument on the Subaru Telescope and offers a chance to investigate the possibility of life on planets around nearby stars. With such a successful first result, we can expect that the Subaru Telescope will discover more, potentially even better, candidates for habitable planets around red dwarfs.

Red dwarfs, stars smaller than the Sun, account for three-quarters of the stars in the Milky Way Galaxy, and are abundant in the neighborhood around the Sun. As such, they are important targets in the search for nearby extra-solar planets and extraterrestrial life. But red dwarfs are cool and don’t emit much visible light compared to other types of stars, making it difficult to study them.

In the infrared wavelengths red dwarfs are brighter. So, the Astrobiology Center in Japan developed an infrared observational instrument mounted on the Subaru Telescope to search for signs of planets around red dwarf stars. The instrument is called IRD for Infrared Doppler, the observational method used in this search.

Artificial Intelligence Edges Closer to the Clinic

TransMED can help predict the outcomes of COVID-19 patients, generating predictions from different kinds of clinical data, including clinical notes, laboratory tests, diagnosis codes and prescribed drugs. The other uniqueness of TransMED lies in its ability to transfer learn from existing diseases to better predict and reason about progression of new and rare diseases. 
Credit: Shannon Colson | Pacific Northwest National Laboratory

The beginning of the COVID-19 pandemic presented a huge challenge to healthcare workers. Doctors struggled to predict how different patients would fare under treatment against the novel SARS-CoV-2 virus. Deciding how to triage medical resources when presented with very little information took a mental and physical toll on caregivers as the pandemic progressed.

To ease this burden, researchers at Pacific Northwest National Laboratory (PNNL), Stanford University, Virginia Tech, and John Snow Labs developed TransMED, a first-of-its-kind artificial intelligence (AI) prediction tool aimed at addressing issues caused by emerging or rare diseases.

“As COVID-19 unfolded over 2020, it brought a number of us together into thinking how and where we could contribute meaningfully,” said chief scientist Sutanay Choudhury. “We decided we could make the most impact if we worked on the problem of predicting patient outcomes.”

“COVID presented a unique challenge,” said Khushbu Agarwal, lead author of the study published in Nature Scientific Reports. “We had very limited patient data for training an AI model that could learn the complex patterns underlying COVID patient trajectories.”

The multi-institutional team developed TransMED to address this challenge, analyzing data from existing diseases to predict outcomes of an emerging disease.

New Method to Promote Biofilm Formation and Increase Efficiency of Biocatalysis

 The researchers screened synthetic polymers for their ability to induce biofilm formation in a strain of E. coli (MC4100), which is known to be poor at forming biofilms. They also monitored the biomass and biocatalytic activity of both MC4100 and PHL644 (a good biofilm former), incubated the presence of these polymers, and found that MC4100 matched and even outperformed PHL644.
Credit: EzumeImages

Birmingham scientists have revealed a new method to increase efficiency in biocatalysis, in a paper published today in Materials Horizons.

Biocatalysis uses enzymes, cells or microbes to catalyze chemical reactions, and is used in settings such as the food and chemical industries to make products that are not accessible by chemical synthesis. It can produce pharmaceuticals, fine chemicals, or food ingredients on an industrial scale.

However, a major challenge in biocatalysis is that the most commonly used microbes, such as probiotics and non-pathogenic strains of Escherichia coli, are not necessarily good at forming biofilms, the growth promoting ecosystems that form a protective micro-environment around communities of microbes and increase their resilience and so boost productivity.

This problem is normally solved by genetic engineering, but researchers Dr Tim Overton from the university’s School of Chemical Engineering, and Dr Francisco Fernández Trillo from the School of Chemistry*, both of whom are members of the Institute of Microbiology and Infection, set out to create an alternative method to bypass this costly and time-consuming process.

The researchers identified a library of synthetic polymers and screened them for their ability to induce biofilm formation in E. coli, a bacterium that is one of the most widely studied micro-organisms, and commonly used in biocatalysis.

Why are some birds more intelligent than others?

Barbados bullfinch flying off with sugar packet.
Resized Image using AI by SFLORG
Source: McGill University

If you’ve ever seen a starling peck open a garbage bag or a grackle steal your dog pellets, you get a sense that some birds have learned to take advantage of new feeding opportunities – a clear sign of their intelligence. Scientists have long wondered why certain species of birds are more innovative than others, and whether these capacities stem from larger brains (which intuitively seems likely) or from a greater number of neurons in specific areas of the brain.

It turns out that it’s a bit of both, according to a recent study by an international team that included members from McGill University published in Nature Ecology and Evolution.

More neurons in the right place tied to greater intelligence in birds

The researchers used a new technique to estimate the number of neurons in a specific part of the brain called the pallium in 111 bird species. The pallium in birds is the equivalent of the human cerebral cortex, which is involved in memory, learning, reasoning, and problem-solving, among other things. When these estimates about neuron numbers in the pallium were combined with information about over 4,000 foraging innovations, the team found that the species with the higher numbers of neurons in the pallium were also likely to be the most innovative.

Scientists reveal distribution of dark matter around galaxies 12 billion years ago–further back in time than ever before

 The radiation residue from the Big Bang, distorted by dark matter 12 billion years ago.
Credit: Reiko Matsushita

A collaboration led by scientists at Nagoya University in Japan has investigated the nature of dark matter surrounding galaxies seen as they were 12 billion years ago, billions of years further back in time than ever before. Their findings, published in Physical Review Letters, offer the tantalizing possibility that the fundamental rules of cosmology may differ when examining the early history of our universe.

Seeing something that happened such a long time ago is difficult. Because of the finite speed of light, we see distant galaxies not as they are today, but as they were billions of years ago. But even more challenging is observing dark matter, which does not emit light.

Consider a distant source galaxy, even further away than the galaxy whose dark matter one wants to investigate. The gravitational pull of the foreground galaxy, including its dark matter, distorts the surrounding space and time, as predicted by Einstein’s theory of general relativity. As the light from the source galaxy travels through this distortion, it bends, changing the apparent shape of the galaxy. The greater the amount of dark matter, the greater the distortion. Thus, scientists can measure the amount of dark matter around the foreground galaxy (the “lens” galaxy) from the distortion.

However, beyond a certain point scientists encounter a problem. The galaxies in the deepest reaches of the universe are incredibly faint. As a result, the further away from Earth we look, the less effective this technique becomes. The lensing distortion is subtle and difficult to detect in most cases, so many background galaxies are necessary to detect the signal.

New Mexico Mammoths Among Best Evidence for Early Humans in North America

Close up of the bone pile during excavation. This random mix of ribs, broken cranial bones, a molar, bone fragments, and stone cobbles is a refuse pile from the butchered mammoths. It was preserved beneath the adult mammoth’s skull and tusks.
Credit: Timothy Rowe / The University of Texas at Austin.

About 37,000 years ago, a mother mammoth and her calf met their end at the hands of human beings.

Bones from the butchering site record how humans shaped pieces of their long bones into disposable blades to break down their carcasses, and rendered their fat over a fire. But a key detail sets this site apart from others from this era. It’s in New Mexico – a place where most archaeological evidence does not place humans until tens of thousands of years later.

A recent study led by scientists with The University of Texas at Austin finds that the site offers some of the most conclusive evidence for humans settling in North America much earlier than conventionally thought.

The researchers revealed a wealth of evidence rarely found in one place. It includes fossils with blunt-force fractures, bone flake knives with worn edges, and signs of controlled fire. And thanks to carbon dating analysis on collagen extracted from the mammoth bones, the site also comes with a settled age of 36,250 to 38,900 years old, making it among the oldest known sites left behind by ancient humans in North America.

“What we’ve got is amazing,” said lead author Timothy Rowe, a paleontologist and a professor in the UT Jackson School of Geosciences. “It’s not a charismatic site with a beautiful skeleton laid out on its side. It’s all busted up. But that’s what the story is.”

NIST Researchers Develop Miniature Lens for Trapping Atoms

Graphical illustration of light focusing using a planar glass surface studded with millions of nanopillars (referred to as a metalens) forming an optical tweezer. (A) Device cross section depicts plane waves of light that come to a focus through secondary wavelets generated by nanopillars of varying size. (B) The same metalens is used to trap and image single rubidium atoms.
Credit: Sean Kelley/NIST

Atoms are notoriously difficult to control. They zigzag like fireflies, tunnel out of the strongest containers and jitter even at temperatures near absolute zero.

Nonetheless, scientists need to trap and manipulate single atoms in order for quantum devices, such as atomic clocks or quantum computers, to operate properly. If individual atoms can be corralled and controlled in large arrays, they can serve as quantum bits, or qubits — tiny discrete units of information whose state or orientation may eventually be used to carry out calculations at speeds far greater than the fastest supercomputer.

Researchers at the National Institute of Standards and Technology (NIST), together with collaborators from JILA — a joint institute of the University of Colorado and NIST in Boulder — have for the first time demonstrated that they can trap single atoms using a novel miniaturized version of “optical tweezers” — a system that grabs atoms using a laser beam as chopsticks.

Ordinarily, optical tweezers, which garnered the 2018 Nobel Prize in Physics, feature bulky centimeter-size lenses or microscope objectives outside the vacuum holding individual atoms. NIST and JILA have previously used the technique with great success to create an atomic clock.

In the new design, instead of typical lenses, the NIST team used unconventional optics — a square glass wafer about 4 millimeters in length imprinted with millions of pillars only a few hundreds of nanometers (billionths of a meter) in height that collectively act as tiny lenses. These imprinted surfaces, dubbed metasurfaces, focus laser light to trap, manipulate and image individual atoms within a vapor. The metasurfaces can operate in the vacuum where the cloud of trapped atoms is located, unlike ordinary optical tweezers.

Triazavirin to Be Tested for Effectiveness Against Tick-Borne Encephalitis

Triazavirin was developed by scientists of the Ural Federal University and the Ural Branch of the Russian Academy of Sciences.
Credit: UrFU Press Service

The scientific community has provided research recommendations

The Medsintez plant, the manufacturer of the antiviral drug Triazavirin, plans to conduct studies of the drug for effectiveness against tick-borne encephalitis. Aleksandr Petrov, Chairman of the Board of Directors of the Medsintez Plant LLC, notes that the company has already received recommendations from the scientific community. This was reported by TASS.

"The effectiveness of Triazavirin against tick-borne encephalitis is a very interesting topic to study. Scientists are already saying that the drug can be effective against this virus. Currently we are guided by the opinion of scientists, that is why we are considering the possibility of conducting such studies," said Petrov.

He stressed that this year in some regions there is a high activity of ticks and increased detection of cases of encephalitis, that is why Triazavirin research in this area is relevant.

Medsintez plant is located in Novouralsk (Sverdlovsk region). It specializes in the production of pharmaceutical products. The plant produces infusion solutions, ready forms of genetically engineered human insulin, solid and liquid forms of drugs. The plant manufactures licensed products and is engaged in the creation of new drugs.

Source/Credit: Ural Federal University


Black cardamom effective against lung cancer cells

NUS researchers embarked on a scientific study of black cardamom, a spice used in Indian Ayurvedic medicine, as a source of potent bioactive compounds that are effective against lung cancer cells. Source: National University of Singapore

The main challenges associated with existing lung cancer drugs are severe side effects and drug resistance. There is hence a constant need to explore new molecules for improving the survival rate and quality of life of lung cancer patients.

In Indian Ayurvedic medicine, black cardamom has been used in formulations to treat cancer and lung conditions. A team of researchers from the NUS Faculty of Science, NUS Yong Loo Lin School of Medicine, and NUS College of Design and Engineering studied the scientific basis behind this traditional medicinal practice and provided evidence of the cytotoxic effect of black cardamom on lung cancer cells. The research highlighted the spice as a source of potent bioactives, such as cardamonin and alpinetin, which could be used in the treatment or prevention of lung cancer. The study is the first to report the association of black cardamom extract with oxidative stress induction in lung cancer cells, and compare the spice’s effects on lung, breast and liver cancer cells.

The findings could potentially lead to the discovery of safe and effective new bioactives which can prevent or cure cancer formation. The research was first published in the Journal of Ethnopharmacology.

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