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Prostaglandin E2 (PGE2), a bioactive lipid derived from arachidonic acid, mediates a broad range of physiological processes through four G protein-coupled receptor (GPCR) subtypes: EP1–EP4. While the high-resolution structures of EP2, EP3 and EP4 have been resolved, EP1 remained structurally uncharacterized due to its intrinsic instability, hindering detailed understanding of its Gq-mediated signaling.

In a study published in Proceedings of the National Academy of Sciences, a research team led by Eric H. Xu (Xu Huaqiang) and Xu Youwei from the Shanghai Institute of Materia Medica of the Chinese Academy of Sciences reported the cryo– (cryo-EM) structure of the human EP1 receptor in complexes with PGE2 and the heterotrimeric Gq protein, completed structural atlas of EP receptor family, and revealed EP1-specific mechanisms of ligand recognition and signal transduction.

To overcome the instability of EP1, the researchers employed a multi-pronged engineering strategy, including BRIL fusion, truncation of flexible loops, incorporation of a mini-Gq chimera, and NanoBiT-assisted complex stabilization. They resolved the structure of the EP1–PGE2–Gq complex at 2.55 Å resolution using single-particle cryo-EM, enabling detailed analysis of both ligand binding and G protein coupling interfaces.

A research team led by Prof. Wang Mingtai at the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has developed a finely tuned method for growing titanium dioxide nanorod arrays (TiO2-NA) with controllable spacing without changing individual rod size and demonstrated its application in high-performance solar cells.

Their findings, published in Small Methods, offer a new toolkit for crafting nanostructures across clean energy and optoelectronics.

Single-crystalline TiO2 nanorods excel at harvesting light and conducting charge, making them ideal for solar cells, photocatalysts, and sensors. However, traditional fabrication methods link rod density, diameter, and length—if one parameter is adjusted, the others shift accordingly, often affecting device efficiency.

At CERN’s Large Hadron Collider (LHC), lead atom nuclei, accelerated in opposite directions, collide at speeds close to the speed of light. In such scattering processes, the quarks and gluons that make up these nuclei collide, creating other quarks and gluons, produced by the fundamental interaction known as the “strong interaction.” The number of particles created is around one hundred times greater than the initial number.

As the particles created are numerous and interact strongly with one another, emergent phenomena arise: the whole is more than the sum of its parts. More precisely, the 30,000 or so created particles form a fluid (with droplets of femtoscopic size, 10-14 m), where their individuality disappears.

This description has the advantage of simplicity, as the fluid is characterized by a handful of parameters: (about 2,500 billion degrees) and velocity.

A research team from the School of Engineering at the Hong Kong University of Science and Technology has developed a new computational model to study the movement of granular materials such as soils, sands and powders. By integrating the dynamic interactions among particles, air and water phases, this state-of-the-art system can accurately predict landslides, improve irrigation and oil extraction systems, and enhance food and drug production processes.

The flow of granular materials—such as soil, sand and powders used in pharmaceuticals and food production—is the underlying mechanism governing many natural settings and industrial operations. Understanding how these particles interact with surrounding fluids like water and air is crucial for predicting behaviors such as soil collapse or fluid leakage.

However, existing models face challenges in accurately capturing these interactions, especially in partially saturated conditions where forces like and viscosity come into play.

Irritable bowel syndrome (IBS) is a prevalent and debilitating gastrointestinal disorder affecting approximately 5%–10% of the global population. Characterized by abdominal pain, bloating, and altered bowel habits, IBS imposes a significant burden on quality of life and health care systems worldwide.

Despite its prevalence, the exact pathogenesis of IBS remains elusive, and effective prevention strategies are lacking. Di Liu and colleagues conducted a comprehensive Mendelian randomization (MR) study—an approach that uses genetic variants as instrumental variables to infer causality.

The study integrates Mendelian randomization (MR) and multiresponse MR (MR2) analyses to distinguish genuine causal relationships from shared or spurious associations. The research is published in the journal eGastroenterology.

Whether diving off docks, cannonballing into lakes or leaping off the high board, there’s nothing quite like the joy of jumping into water.

Olympic divers turned this natural act into a sophisticated science, with the goal of making a as small as possible. But another sport looks for just the opposite: the extreme maximum splash, one as high, wide and loud as possible.

Welcome to the world of “manu jumping.” Although not a familiar term in the United States, manu jumping is beloved throughout New Zealand. The sport originated in the Māori community, where popping a manu is a way of life. There, manu jumpers leap from bridges, wharves and diving platforms to make the giant splashes.

A team of researchers from TU Dortmund University, the University of Paderborn, and the University of Nottingham has developed a new optical method to detect ultra-weak atomic motion. Their experiment performed in Dortmund has demonstrated unprecedented sensitivity of the detection of atomic motion in crystals by exploiting light interference.

The findings, recently published in Nature Materials, open new ways for studying ultrafast processes in materials.

Precise optical measurements rely on interferometers, where the beam probing a distance of interest interferes with a reference beam traveling a fixed path. This allows for assessing the path length difference of the two beams with high precision. A striking example is gravitational interferometers, which detect induced by a distant event in the universe, such as the collision of black holes.

Quantum annealing is a specific type of quantum computing that can use quantum physics principles to find high-quality solutions to difficult optimization problems. Rather than requiring exact optimal solutions, the study focused on finding solutions within a certain percentage (≥1%) of the optimal value.

Many real-world problems don’t require exact solutions, making this approach practically relevant. For example, in determining which stocks to put into a mutual fund, it is often good enough to just beat a leading market index rather than beating every other stock portfolio.

High-energy particles or gamma rays are usually needed to kick an atomic nucleus up to a higher-energy state. But last year, scientists excited thorium-229 nuclei with just laser light (see Viewpoint: Shedding Light on the Thorium-229 Nuclear Clock Isomer). Laser-excited nuclei could be useful for making precise timekeepers and sensitive quantum sensors. And now, Wolfram Ratzinger at the Weizmann Institute of Science in Israel and his colleagues have shown how these nuclei also provide a way to detect certain speculative particles that may constitute dark matter [1].

Several models of dark matter involve axions or other extremely light bosons. Thanks to their lightness, these particles would have to be abundant—so much so that they would collectively behave like a classical field, oscillating at a frequency proportional to their mass. The particles’ interactions with the building blocks of nuclei—quarks and gluons—would cause various nuclear properties to oscillate at that same frequency. Among those properties is the energy of the photon emitted by an excited thorium-229 nucleus. Crucially, the oscillations in that energy are predicted to be much more pronounced, and therefore easier to detect, than those in other properties.

Ratzinger and his colleagues conducted the first-ever search for these oscillations in a previously reported spectrum of light emitted by excited thorium-229 nuclei. Finding no oscillations, the researchers set upper limits on the coupling strength of ultralight dark matter particles to quarks and gluons for particles ranging in mass from 10–20 to 10–13 eV. These limits are less stringent than those obtained through other means, but the team anticipates that ongoing and future experiments could set much stronger and possibly decisive constraints.

To validate these simulated results, PhD student Omri Cohen fabricated a series of disks from two polymer layers. The lower layer was patterned with a regular matrix and the upper one consisted of thin lines radiating out from the center. When the disks were heated and then cooled again, the matrix layer remained the same, while the upper layer contracted by a varying amount along the radial direction. This difference induced a curvature in the disk, and the team was able to replicate the simulated series of shape transitions by varying the curvature and thickness of the disks.

Further analysis shows that the formation of each cusp acts as a focal point for the stresses that accumulate in the petal. In older petals this localized concentration of stress inhibits growth around the cusps, producing a concave distortion on the rounded edge of the petal. “This completes a nice feedback cycle,” explains Sharon. “Simple growth first generates Mainardi-Codazzi-Peterson incompatibility, leading to a mechanical instability that forms cusps. These cusps then focus the stress, which affects the further growth of the tissue.”

Understanding the mechanical mechanisms that alter the shape of rose petals as they grow could inform the design of self-shaping materials and structures for applications like soft robotics and deployable spacecraft. “The idea is to program internal forces to enable the material to shape itself, and this work offers a new strategy for creating more localized shaping,” explains Benoît Roman of ESPCI ParisTech, an expert in shape-changing materials. “But the real value of this study is that it provides a perfect example of using physics to uncover and describe a deep and general phenomenon.”