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Astrophysicists have unearthed a surprising diversity in the ways in which white dwarf stars explode in deep space after assessing almost 4,000 such events captured in detail by a next-gen astronomical sky survey. Their findings may help us more accurately measure distances in the universe and further our knowledge of “dark energy.”
The dramatic explosions of white dwarf stars at the ends of their lives have for decades played a pivotal role in the study of dark energy—the mysterious force responsible for the accelerating expansion of the universe. They also provide the origin of many elements in our periodic table, such as titanium, iron and nickel, which are formed in the extremely dense and hot conditions present during their explosions.
A major milestone has been achieved in our understanding of these explosive transients with the release of a major dataset, and associated 21 publications in an Astronomy & Astrophysics special issue.
University of Queensland researchers have for the first time introduced genetic material into plants via their roots, opening a potential pathway for rapid crop improvement. The research is published in Nature Plants.
Professor Bernard Carroll from UQ’s School of Chemistry and Molecular Biosciences said nanoparticle technology could help fine-tune plant genes to increase crop yield and improve food quality.
“Traditional plant breeding and genetic modification take many generations to produce a new crop variety, which is time-consuming and expensive,” Professor Carroll said.
In April 1982, Prof. Dan Shechtman of the Technion–Israel Institute of Technology made the discovery that would later earn him the 2011 Nobel Prize in Chemistry: the quasiperiodic crystal. According to diffraction measurements made with an electron microscope, the new material appeared “disorganized” at smaller scales, yet with a distinct order and symmetry apparent at a larger scale.
This form of matter was considered impossible, and it took many years to convince the scientific community of the discovery’s validity. The first physicists to theoretically explain this discovery were Prof. Dov Levine, then a doctoral student at the University of Pennsylvania and now a faculty member in the Technion Physics department, and his advisor, Prof. Paul Steinhardt.
The key insight that enabled their explanation was that quasicrystals were, in fact, periodic—but in a higher dimension than the one in which they exist physically. Using this realization, the physicists were able to describe and predict mechanical and thermodynamic properties of quasicrystals.
Three studies at the University of Zurich demonstrate that hypnosis alters activity in the large-scale functional networks of the brain. It also affects the neurochemical milieu of specific brain areas.
Hypnosis has so far been something of a black box from the scientific perspective. Up to now, we have not had the data to prove whether hypnosis really is an extraordinary state of human consciousness, or simply in the subject’s imagination. Yet it remains a topic of fascination for many.
A well-known women’s magazine recently dedicated an entire dossier to hypnosis. And now and again we’ll hear of a remarkable hypnosis success story. For example, in 2018 at the Hirslanden Klinik St. Anna in Lucerne, a 45-year-old man had a metal plate removed from his lower arm under hypnosis only, without any anesthetic or pain relief. Much to the amazement of the surgical team, the man did not experience any significant pain either during or after the operation, as the Swiss public broadcaster SRF Puls health magazine program reported on 17 September of that year.
Mice learn best when the opponent opposing forces of dopamine and serotonin work together, a new study shows, helping to resolve long-standing questions about the neuromodulators’ relationship.
In the intricate dance of learning and motivation, two key brain chemicals—dopamine (DA) and serotonin (5HT)—play opposing yet deeply interconnected roles. Scientists have long speculated how these neuromodulators work together to shape our ability to form new associations, but testing these theories directly has been a challenge.
Now, researchers have developed a new mouse model that allows them to simultaneously study both dopamine and serotonin neurons in the brain. Their experiments focused on the nucleus accumbens (NAc), a region known for processing rewards. By monitoring neural activity, they found that receiving a reward boosts dopamine signals while simultaneously suppressing serotonin signals.
To understand how this dynamic affects learning, the team used optogenetics—a technique that uses light to control brain activity. They found that disrupting dopamine or serotonin alone caused only mild learning impairments. However, when both signals were suppressed together, the mice struggled significantly to learn from rewards. On the flip side, artificially recreating both dopamine and serotonin responses helped the mice learn more effectively than manipulating either signal alone.
These findings reveal that dopamine and serotonin work in opposition to control reinforcement and learning. Instead of acting in isolation, they create a delicate balance that shapes how we associate actions with rewards—providing new insights into how the brain learns and adapts.
The trihydrogen cation (H3+) plays a key role in the interstellar chemistry. Here the authors, using state of the art experiments and computation, identify factors that govern H3+ formation from doubly ionized small organic molecules, offering guidelines for examining alternative sources of H3+ in the universe.
An electrospray engine applies an electric field to a conductive liquid, generating a high-speed jet of tiny droplets that can propel a spacecraft. These miniature engines are ideal for small satellites called CubeSats that are often used in academic research.
Since electrospray engines utilize propellant more efficiently than the powerful, chemical rockets used on the launchpad, they are better suited for precise, in-orbit maneuvers. The thrust generated by an electrospray emitter is tiny, so electrospray engines typically use an array of emitters that are uniformly operated in parallel.
However, these multiplexed electrospray thrusters are typically made via expensive and time-consuming semiconductor cleanroom fabrication, which limits who can manufacture them and how the devices can be applied.
Nanoparticle researchers spend most of their time on one thing: counting and measuring nanoparticles. Each step of the way, they have to check their results. They usually do this by analyzing microscopic images of hundreds of nanoparticles packed tightly together. Counting and measuring them takes a long time, but this work is essential for completing the statistical analyses required for conducting the next, suitably optimized nanoparticle synthesis.
Alexander Wittemann is a professor of colloid chemistry at the University of Konstanz. He and his team repeat this process every day. “When I worked on my doctoral thesis, we used a large particle counting machine for these measurements. It was like a cash register, and, at the time, I was really happy when I could measure three hundred nanoparticles a day,” Wittemann remembers.
However, reliable statistics require thousands of measurements for each sample. Today, the increased use of computer technology means the process can move much more rapidly. At the same time, the automated methods are very prone to errors, and many measurements still need to be conducted, or at least double-checked, by the researchers themselves.
Nanozymes are a class of nanomaterials that exhibit catalytic functions analogous to those of natural enzymes. They demonstrate considerable promise in the biomedical field, particularly in the treatment of bone infections, due to their distinctive physicochemical properties and adjustable catalytic activities. Bone infections (e.g., periprosthetic infections and osteomyelitis) are infections that are challenging to treat clinically. Traditional treatments often encounter issues related to drug resistance and suboptimal anti-infection outcomes. The advent of nanozymes has brought with it a new avenue of hope for the treatment of bone infections.
