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Sex Differences in Left Ventricular Remodeling for Aortic Regurgitation
In a multicenter cohort study of adults with moderate-severe AorticRegurgitation and preserved ejection fraction, women experienced higher mortality under medical management compared to men.
The optimal left ventricular end-systolic diameter index threshold associated with mortality was similar for both sexes (≥20 mm/m²), while volumetric thresholds differed: 40 mL/m² for women and 45 mL/m² for men.
These findings support the use of sex-specific thresholds to improve risk stratification and timing of intervention.
This cohort study evaluates sex differences in left ventricular remodeling among individuals with aortic regurgitation.
Ferroplasticity drives social isolation-induced anxiety via a ventral hippocampal iron-α-synuclein axis
Online now: Social isolation is a major risk factor for anxiety disorders. Wang et al. reveal that isolation of mice drives anxiety through an iron-dependent synaptic remodeling mechanism (ferroplasticity) in the ventral hippocampus. Targeting excess brain iron or α-synuclein signaling via non-invasive intranasal delivery rescues anxiety, offering a novel therapeutic strategy.
How your life story leaves epigenetic fingerprints on your immune cells
The COVID-19 pandemic gave us tremendous perspective on how wildly symptoms and outcomes can vary between patients experiencing the same infection. How can two people infected by the same pathogen have such different responses? It largely comes down to variability in genetics (the genes you inherit) and life experience (your environmental, infection, and vaccination history).
These two influences are imprinted on our cells through small molecular alterations called epigenetic changes, which shape cell identity and function by controlling whether genes are turned “on” or “off.”
Salk Institute researchers are debuting a new epigenetic catalog that reveals the distinct effects of genetic inheritance and life experience on various types of immune cells. The new cell type-specific database, published in Nature Genetics, helps explain individual differences in immune responses and may serve as the foundation for more effective and personalized therapeutics.
Earth’s Magnetic Field as Dark-Matter Sensor
One candidate for dark matter is a subatomic particle carrying a tiny electric charge many times smaller than that of the electron. This so-called millicharged dark matter would presumably interact with Earth’s magnetic field, generating potentially observable time variations in the magnetic field on Earth’s surface. A new study of archived data looked for this signal but came up empty [1]. The research has thus placed strict limits on the properties that a millicharged dark-matter particle could have if it has a small mass (in the range of 10–18 to 10–15 eV/c2).
Dark matter can’t have a typical electric charge, as it would interact too strongly with normal matter. But a small charge is possible and could produce features in-line with dark-matter models. Astrophysicists have looked for evidence of millicharged dark matter in stellar evolution data, as such particles could cause stars to cool faster than expected. No such signal has been seen, ruling out a large portion of millicharged-dark-matter parameter space.
Lei Wu from Nanjing Normal University in China and colleagues have explored another potential signal in the geomagnetic field. According to the team’s calculations, low-mass millicharged particles could annihilate each other in the presence of the planet’s magnetic-field background, producing an effective electric current that would generate its own magnetic field. This dark-matter-induced field would be small (roughly a million times less than Earth’s field), but it might be detectable owing to its peculiar time variation (at frequencies less than 1 Hz). The researchers failed to find such a signal in previously collected geomagnetic observations. The absence rules out low-mass dark-matter charges in a large range down to 10−30 times the electron charge. Such a small charge may seem implausible, but “nature sometimes surprises us,” Wu says.
‘Goldilocks size’ rhodium clusters advance reusable heterogeneous catalysts for hydroformylation
Recent research has demonstrated that a rhodium (Rh) cluster of an optimal, intermediate size—neither too small nor too large—exhibits the highest catalytic activity in hydroformylation reactions. Similar to the concept of finding the “just right” balance, the study identifies this so-called “Goldilocks size” as crucial for maximizing catalyst efficiency. The study is published in the journal ACS Catalysis and was featured as the cover story.
Led by Professor Kwangjin An from the School of Energy and Chemical Engineering at UNIST, in collaboration with Professor Jeong Woo Han from Seoul National University, the research demonstrates that when Rh exists as a cluster —comprising about 10 atoms—it outperforms both single-atom and nanoparticle forms in reaction speed and activity.
Hydroformylation is a vital industrial process used for producing raw materials for plastics, detergents, and other chemicals. Currently, many Rh catalysts are homogeneous—dissolved in liquids—which complicates separation and recycling. This challenge has driven efforts to develop solid, heterogeneous Rh catalysts that are easier to recover and reuse.
From stellar engines to Dyson bubbles, alien megastructures could hold themselves together under the right conditions
New theoretical models have strengthened the case that immense, energy-harvesting structures orbiting their host stars could exist in principle in distant stellar systems. With the right engineering precautions, calculations published in Monthly Notices of the Royal Astronomical Society, carried out by Colin McInnes at the University of Glasgow, show that both stellar engines and Dyson bubbles can become gravitationally stable, allowing them to tap into the vast amounts of energy emitted by their host stars.
For decades, astronomers have pondered the possibility of alien civilizations far more technologically advanced than our own. While these studies remain entirely speculative, many have converged on similar ideas for harvesting stellar energy: envisioning vast structures deployed around host stars.
If such structures could exist, they would provide civilizations with vastly more energy than any planet could offer—enough for ventures ranging from the terraforming of new worlds, to interstellar journeys spanning many generations.
Amazon Leo satellites exceed brightness limits, study finds
Seeing a satellite zip across the night sky can be a fascinating sight. However, what may be spectacular for people on the ground is becoming a major problem for astronomers. A new study published on the arXiv preprint server has found that satellites from Amazon’s mega Leo constellation (originally known as Project Kuiper) are bright enough to disrupt astronomical research.
Amazon launched the first satellites for its Project Kuiper in April 2025. Eventually, the constellation will comprise 3,232 satellites to provide high-speed internet across the globe. However, this connectivity can come at a cost.
NASA’s Juno measures thickness of Europa’s ice shell
Data from NASA’s Juno mission has provided new insights into the thickness and subsurface structure of the icy shell encasing Jupiter’s moon Europa. Using the spacecraft’s Microwave Radiometer (MWR), mission scientists determined that the shell averages about 18 miles (29 kilometers) thick in the region observed during Juno’s 2022 flyby of Europa. The Juno measurement is the first to discriminate between thin and thick shell models that have suggested the ice shell is anywhere from less than half a mile to tens of miles thick.
Slightly smaller than Earth’s moon, Europa is one of the solar system’s highest-priority science targets for investigating habitability. Evidence suggests that the ingredients for life may exist in the saltwater ocean that lies beneath its ice shell. Uncovering a variety of characteristics of the ice shell, including its thickness, provides crucial pieces of the puzzle for understanding the moon’s internal workings and the potential for the existence of a habitable environment.
The new estimate on the ice thickness in the near-surface icy crust was published on Dec. 17 in the journal Nature Astronomy.
3D material mimics graphene’s electron flow for green computing
University of Liverpool researchers have discovered a way to host some of the most significant properties of graphene in a three-dimensional (3D) material, potentially removing the hurdles for these properties to be used at scale in green computing. The work is published in the journal Matter.
Graphene is famous for being incredibly strong, lightweight, and an excellent conductor of electricity and its applications range from electronics to aerospace and medical technologies. However, its two-dimensional (2D) structure makes it mechanically fragile and limits its use in demanding environments and large-scale applications.