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Neurotransmitter-activated GPCR signaling in myelin plasticity

Myelination is increasingly recognized as a dynamic and adaptive process regulated by oligodendrocytes throughout life. Beyond providing electrical insulation, myelin supports axonal metabolism and may serve as an energy reservoir under metabolic stress, highlighting the importance of physiological myelin turnover. Dysregulation of myelin dynamics contributes to a wide spectrum of neurological disorders, including demyelinating, neurodegenerative, and neuropsychiatric diseases. Growing evidence indicates that neurotransmitter signaling through G protein-coupled receptors (GPCRs) expressed by oligodendrocyte lineage cells regulates myelin formation, remodeling, and repair.

Gut microbiota-derived deoxycholic acid shapes an immunosuppressive tumor microenvironment and promotes breast cancer progression

Li et al. identify deoxycholic acid as a microbiota-derived driver of breast cancer progression. Deoxycholic acid activates farnesoid X receptor signaling to induce interleukin-6 production, promoting immunosuppressive cell recruitment and establishing a metabolite-driven immune regulatory axis with therapeutic potential.

Brighter red micro-LEDs could help solve full-color display stability challenge

Researchers at The University of Osaka, in collaboration with Ritsumeikan University, have demonstrated that growing europium-doped gallium nitride (Eu-doped GaN) on a semipolar crystal plane dramatically improves red light emission. The team found that this approach selectively promotes the formation of highly efficient Eu luminescent centers, resulting in red emission intensity more than 3.6 times higher than that of conventionally grown polar-plane material.

The study is published in the journal Applied Physics Letters.

Red emitters based on Eu-doped GaN are attracting attention as promising light sources for next-generation micro-LED displays because they can provide narrow-linewidth, wavelength-stable red emission based on intra-4f-shell transitions of Eu ions. This is particularly important for full-color monolithic integration with blue and green InGaN LEDs, where wavelength stability under device operation is essential.

Gravitational waves from colliding black holes may allow detection of dark matter

Dark matter is thought to make up most of the matter in the universe, but the only way it interacts with its surroundings is through gravity. If two colliding black holes spiral through a dense region of dark matter and merge, gravitational waves rippling across space and time could carry an imprint of that dark matter.

Now, physicists may be able to spot such imprints of dark matter in gravitational waves that are detected on Earth.

Researchers at MIT and in Europe have developed a method that makes predictions for what a gravitational wave should look like if it were produced by black holes that moved through dark matter, rather than empty space. They applied the technique to publicly available gravitational-wave data previously recorded by LIGO-Virgo-KAGRA (LVK), the global network of observatories that detect gravitational waves from black hole mergers and other far-off astrophysical sources.

Gravitational wave detectors can now ‘autotune’ signals to harmonize the heavens

Gravitational wave researchers working on the world’s most sensitive scientific instruments have found a way to tune their detectors using a process akin to the pitch-correction used in music production.

Scientists at the international LIGO, Virgo and KAGRA (LVK) gravitational wave observatory collaboration have employed the technique, which they call astrophysical calibration, to use gravitational-wave signals to measure the response of their incredibly sensitive instruments.

It enables them to ensure that they can clearly “hear” the sounds of colossal cosmic events like the collision of black holes, even when one gravitational wave detector is slightly out of tune. This is crucial to accurately interpret the signals and find their source location.

80 years after the Trinity nuclear test, scientists identify new molecule-trapping crystal formed in the blast

Matter behaves strangely under extreme conditions, and often, remnants of these behaviors are left behind even when conditions return to normal. The Trinity nuclear test in 1945 left behind such remnants, and now, 80 years after the explosion, researchers have identified another unique example of what happens when various materials are heated to temperatures exceeding 1,500 °C (2,730 °F) and put under pressures tens of thousands of times atmospheric pressure.

The team describes a clathrate compound never before found among nuclear-explosion products in their new study, published in the Proceedings of the National Academy of Sciences.

AI surrogate accelerates nonlinear optics simulations by orders of magnitude

Simulating the nonlinear optical physics that underlies ultrafast laser systems is computationally demanding—a practical bottleneck in settings that require rapid feedback. A study by researchers at Stanford University, University of California, Los Angeles (UCLA), and SLAC National Accelerator Laboratory introduces a deep learning surrogate that delivers orders-of-magnitude acceleration over conventional simulation methods, while maintaining high fidelity across a challenging range of pulse shapes.

The work centers on second-order nonlinear optics (χ² processes), in which light waves exchange energy inside specially engineered crystals to generate new frequencies and tailored pulse shapes. In particle accelerator facilities, these processes play a key role. At SLAC’s upgraded Linac Coherent Light Source (LCLS-II), infrared laser pulses are first to green light and then to ultraviolet (UV). The UV pulse strikes a cathode to liberate an electron bunch that is subsequently accelerated and modulated to produce intense X-ray pulses. The temporal shape of the UV pulse directly influences the properties of that electron bunch—and ultimately the quality of the X-rays available for science.

A surrogate model for the nonlinear χ² frequency conversion step at the heart of this process is reported in Advanced Photonics.

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