. Scientific Frontline

Wednesday, March 13, 2024

Scientists reveal the first unconventional superconductor that can be found in mineral form in nature

A miassite crystal grown by Paul Canfield.
Photo Credit: Paul Canfield

Scientists from Ames National Laboratory have identified the first unconventional superconductor with a chemical composition also found in nature. Miassite is one of only four minerals found in nature that act as a superconductor when grown in the lab. The team’s investigation of miassite revealed that it is an unconventional superconductor with properties similar to high-temperature superconductors. Their findings further scientists’ understanding of this type of superconductivity, which could lead to more sustainable and economical superconductor-based technology in the future.

Superconductivity is when a material can conduct electricity without energy loss. Superconductors have applications including medical MRI machines, power cables, and quantum computers. Conventional superconductors are well understood but have low critical temperatures. The critical temperature is the highest temperature at which a material acts as a superconductor.

In the 1980s, scientists discovered unconventional superconductors, many of which have much higher critical temperatures. According to Ruslan Prozorov, a scientist at Ames Lab, all these materials are grown in the lab. This fact has led to the general belief that unconventional superconductivity is not a natural phenomenon.

Prozorov explained that it is difficult to find superconductors in nature because most superconducting elements and compounds are metals and tend to react with other elements, like oxygen. He said that miassite (Rh17S15) is an interesting mineral for several reasons, one of which is its complex chemical formula. “Intuitively, you think that this is something which is produced deliberately during a focused search, and it cannot possibly exist in nature,” said Prozorov, “But it turns out it does.”

It's in the Blood: Donor Diets Can Trigger Allergic Reactions in Blood Recipients

Photo Credit: Aman Chaturvedi

Blood transfusions are often life-saving procedures in various medical settings. They are required not only after severe blood loss due to surgery or trauma but also as standard treatment for certain blood disorders like anemia and sickle cell disease. However, blood transfusions can have serious side effects, with allergic transfusion reactions (ATRs) being particularly prevalent among children. Although scientists believe ATRs are caused by immunoglobulin E (IgE)-mediated type 1 allergy (or “immediate hypersensitivity”), the responsible allergens are not always known.

Against this backdrop, a research team composed of Dr. Ryu Yanagisawa of Shinshu University Hospital, Japan, alongside Dr. Minoru Tozuka and Dr. Yasunori Ito from Nagano Children's Hospital, Japan, set out to find more answers. In their latest study, published online in the journal Allergy, the researchers focused their attention on what might have appeared to be an unlikely suspect. Dr. Yanagisawa, wo led the study at the University’s Division of Blood Transfusion, explains: “In our previous study, we found that pediatric patients with food allergies were characteristically more prone to ATRs. Considering that food allergies are also more prevalent in children, we decided to investigate whether the food the donor ate before giving blood could be associated with the development of ATRs in children with food allergies.”

Satellites for quantum communications

Tobias Vogl investigates single photon sources in 2D materials in an experimental setup
Photo Credit: Jens Meyer / University of Jena

Through steady advances in the development of quantum computers and their ever-improving performance, it will be possible in the future to crack our current encryption processes. To address this challenge, researchers at the Technical University of Munich (TUM) are participating in an international research consortium to develop encryption methods that will apply physical laws to prevent the interception of messages. To safeguard communications over long distances, the QUICK³ space mission will deploy satellites.

How can it be ensured that data transmitted through the internet can be read only by the intended recipient? At present our data are encrypted with mathematical methods that rely on the idea that the factorization of large numbers is a difficult task. With the increasing power of quantum computers, however, these mathematical codes will probably no longer be secure in the future.

Ultra-short light pulses enable high-precision "artificial nose"

Hongtao Hu and Vinzenz Stummer
Photo Credit: Courtesy of Technische Universität Wien

A new spectroscopy method has been developed at TU Wien: Using a series of laser pulses, chemical analyses can be carried out much faster and more precisely than before.

Whether you want to analyze environmental samples in nature or monitor a chemical experiment, you often need highly sensitive sensors that can "sniff out" even tiny traces of a certain gas with extreme accuracy. Variants of Raman spectroscopy are often used for this purpose: Different molecules react in very characteristic ways to light of different wavelengths. If you irradiate a sample with the appropriate light and measure exactly how the light is modified by the sample, you can find out whether the sample contains a certain gas or not.

However, scientists at TU Wien (Vienna) have now taken a significant step forward in this area: a new method has been developed to generate and precisely control suitable light for such experiments. This not only enables much greater accuracy than before; the method also works without moving parts and is therefore much faster than the best technologies to date. The method has now been published in the journal Light: Science and Applications.

Is life based on a seeming violation of Newton’s law in molecular interactions?

Interactions between molecules that are not equal and opposite, a seeming violation of Newton’s third law of motion, can occur naturally according to new research. A kinase enzyme adds a chemical modification to other molecules, resulting in a phosphorylated protein. Phosphatase enzymes remove the modifications, such that the kinases create products that are acted upon by phosphatases and vice versa. Researchers demonstrated that the kinase is attracted to the phosphatase, but the phosphatase is repelled by the kinase, in what is called a non-reciprocal interaction.
Illustration Credit: Niladri Sekhar Mandal / Pennsylvania State University
(CC BY-NC-ND 4.0 DEED)

It turns out that every action may not have an equal and opposite reaction, despite what Newton’s third law of motion says, according to new research conducted by a team from Penn State and the University of Maine. The finding could offer insight into how certain molecular interactions could have evolved in a pre-life world.

The work was published in the journal Chem, and the researchers said this is the first demonstration of the mechanism by which these interactions occur at the molecular level. Last year’s discovery by researchers at Kyoto University that sperm movement does not cause an opposite reaction in its environment as it moves provided an example of a seeming violation of Newton’s third law of motion, but it did not address the mechanism.

“We all have heard the phrase ‘every action has an equal and opposite reaction,’ to describe Newton’s third law of motion, but we see examples that seemingly violate this every day, especially in the behavior of complex living systems small and large where there is constant input of energy,” said Ayusman Sen, Verne M. Willaman Professor of Chemistry in the Eberly College of Science at Penn State and one of the research team leaders. “An example at the larger scale is that a predator is attracted to its prey, but the prey is repelled by the predator. This type of interaction is called non-reciprocal, and we were interested to see if it also occurred in the much simpler interactions among molecules with constant energy input.”

Tuesday, March 12, 2024

Scientists develop a rapid gene-editing screen to find effects of cancer mutations

Using a variant of CRISPR genome-editing known as prime editing, MIT researchers have developed a method to screen cancer-associated genetic mutations much more easily and quickly than any existing approach. This illustration, by Samuel Gould’s brother Owen Gould, is an artistic interpretation of the research and the idea of “rewriting the genome,” explains Samuel.
Illustration Credit: Owen Gould
(CC BY-NC-ND 4.0 DEED)

Tumors can carry mutations in hundreds of different genes, and each of those genes may be mutated in different ways — some mutations simply replace one DNA nucleotide with another, while others insert or delete larger sections of DNA.

Until now, there has been no way to quickly and easily screen each of those mutations in their natural setting to see what role they may play in the development, progression, and treatment response of a tumor. Using a variant of CRISPR genome-editing known as prime editing, MIT researchers have now come up with a way to screen those mutations much more easily.

The researchers demonstrated their technique by screening cells with more than 1,000 different mutations of the tumor suppressor gene p53, all of which have been seen in cancer patients. This method, which is easier and faster than any existing approach, and edits the genome rather than introducing an artificial version of the mutant gene, revealed that some p53 mutations are more harmful than previously thought.

The researchers say this technique could also be applied to many other cancer genes, and could eventually be used for precision medicine, to determine how an individual patient’s tumor will respond to a particular treatment.

“In one experiment, you can generate thousands of genotypes that are seen in cancer patients, and immediately test whether one or more of those genotypes are sensitive or resistant to any type of therapy that you’re interested in using,” says Francisco Sanchez-Rivera, an MIT assistant professor of biology, a member of the Koch Institute for Integrative Cancer Research, and the senior author of the study.

MIT graduate student Samuel Gould is the lead author of the paper, which appears today in Nature Biotechnology.

Range-shifting fishes are climate-change losers, according to new research

Pouting (Trisopterus luscus)
Photo Credit: Diego Delso
(CC BY-SA 4.0 DEED)

The warming of the Earth’s oceans due to climate change is affecting where the world’s fishes live, eat and spawn — and often in ways that can negatively impact their populations. That’s according to a new paper in the journal Nature Ecology and Evolution.

The researchers write that populations that experience rapid-range shift decline noticeably, up to 50 per cent over a decade. The populations affected most are those living on the northern poleward edges of their species’ range.

“There is a conventional wisdom among many climate-change biologists that species that shift their ranges quickly by moving northward should provide a mechanism to sustain healthy populations — that shifting species should be climate-change winners. Our results show the exact opposite,” says paper co-author Jean-Philippe Lessard, a professor in the Department of Biology.

“Species that are shifting their range quickly experience little change in their population size in their core range. But some of them experience a major collapse in their populations at the northern edges.

“In fact, the population collapse is mostly driven by the northern poleward populations,” he adds. “We were expecting that many individuals from the core of the range would be moving up north due to climate change and maintain these northern populations. But the northern-edge populations are the ones most likely to collapse.”

Bees master complex tasks through social interaction

Bees can learn complex, multi-step tasks through social interaction, even if they cannot figure them out on their own.
Photo Credit: Michael Hodgins

In a groundbreaking discovery, bumblebees have been shown to possess a previously unseen level of cognitive sophistication.

 A new study, published in Nature, reveals that these bees can learn complex, multi-step tasks through social interaction, even if they cannot figure them out on their own. This challenges the long-held belief that such advanced social learning is unique to humans, and hints at the presence of key elements of cumulative culture in these insects.

Led by Dr Alice Bridges, postdoctoral researcher at the University of Sheffield, the research team designed a two-step puzzle box requiring bumblebees to perform two distinct actions in sequence to access a sweet reward at the end. The temporary reward was eventually taken away, and bees subsequently had to open the whole box before getting the treat. 

While individual bees struggled to solve the puzzle when starting from scratch, those allowed to observe a trained "demonstrator" bee readily learned the entire sequence – even the first step – while only getting a reward at the end.

You Didn’t See It Coming: the Spontaneous Nature of Turbulence

Photo Credit: Scientific Frontline 

We experience turbulence every day: a gust of wind, water gushing down a river or mid-flight bumps on an airplane.

Although it may be easy to understand what causes some kinds of turbulence — a felled tree in a river or a bear splashing around for salmon — there is now evidence that a very small disturbance at the start can have dramatic effects later. Instead of a tree, think of a twig — or even the swerving motion of a molecule.

University of California San Diego Chancellor’s Distinguished Professor of Physics Nigel Goldenfeld, along with his former student Dmytro Bandak, and Professors Alexei Mailybaev and Gregory Eyink, has shown in theoretical models of turbulence that even molecular motions can create large-scale patterns of randomness over a defined period of time. Their work appears in Physical Review Letters.

The butterfly effect

A butterfly flaps its wings in Brazil which later causes a tornado in Texas. Although we may commonly use the phrase to denote the seeming interconnectedness of our own lives, the term “butterfly effect” is sometimes associated with chaos theory. Goldenfeld said their work represents a more extreme version of the butterfly effect, first described by mathematician and meteorologist Edward Lorenz in 1969.

SwRI develops off-road autonomous driving tools focused on camera vision

SwRI is exploring using stereo cameras, or stereovision, as an alternative to lidar sensors in automated vehicles. SwRI's stereovision algorithms create disparity maps that estimate the depth of roadway features and obstacles. The left image shows how a conventional camera sees an off-road trail. The middle image shows a lidar image of the same trail. The right image shows a stereovision disparity map based on SwRI's algorithms, where colors indicate the distance of detected objects (yellow is near and blue is far). The gray/white in the lidar image suggests the outline of trees and a vehicle hood, but it does not indicate depth or distance.
Image Credit: Courtesy of Southwest Research Institute

Southwest Research Institute has developed off-road autonomous driving tools with a focus on stealth for the military and agility for space and agriculture clients. The vision-based system pairs stereo cameras with novel algorithms, eliminating the need for lidar and active sensors.

“We reflected on the toughest machine vision challenges and then focused on achieving dense, robust modeling for off-road navigation,” said Abe Garza, a research engineer in SwRI’s Intelligent Systems Division.

Through internal research, SwRI engineers developed a suite of tools known as the Vision for Off-Road Autonomy (VORA). The passive system can perceive objects, model environments and simultaneously localize and map while navigating off-road environments.

The VORA team envisioned a camera system as a passive sensing alternative to lidar, a light detection and ranging sensor, that emits active lasers to probe objects and calculate depth and distance. Though highly reliable, lidar sensors produce light that can be detected by hostile forces. Radar, which emits radio waves, is also detectable. GPS navigation can be jammed, and its signals are often blocked in canyons and mountains, which can limit agricultural automation.

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