Have you ever felt strangely exhausted after waking up from a dream? Researchers took a look at how the brain allocates energy during sleep to explain this “paradoxical sleep.”

A research team from Saitama University and Taisei Corporation has experimentally clarified how deformation-accommodating tunnel support systems behave under isotropic stress conditions that simulate squeezing ground. Using 1/20-scale laboratory tunnel support models, the team showed that yielding elements can absorb large tunnel deformations and that their installation position influences the deformation pattern of the entire support system.

Researchers have achieved the world’s first demonstration of a gate-defined quantum dot in zinc oxide (ZnO), a material prized for qubit applications. Beyond confirming controlled single-electron behavior, the devices showed an unconventional Kondo effect appearing regardless of electron number—a surprising signature of ZnO’s strong electron correlations and a new platform for quantum technology research.

Researchers from Kochi University of Technology and Nagoya University have developed a self-adaptive copper–cobalt catalyst that efficiently converts nitrate contaminants into ammonia under ambient conditions. By combining advanced operando and quasi-operando spectroscopic analyses with density functional theory calculations, the team discovered that the catalyst dynamically reconstructs during electrochemical nitrate reduction to form hydroxyl-rich Cu–OH active sites. Amorphous cobalt oxide supplies reactive hydrogen via hydrogen spillover, enabling highly efficient ammonia synthesis. The catalyst achieved an ammonia production rate of 54.68 mg h⁻¹ mgcat⁻¹ with a Faradaic efficiency of 95.4% at −0.2 V versus the reversible hydrogen electrode and maintained stable performance for more than 60 hours in a flow cell. The work establishes adaptive catalyst reconstruction as a new design principle for sustainable electrocatalysis.

A fleeting photoinduced electronic state and the subsequent formation of a photoinduced hidden state in a metal–organic framework were captured in just 30 femtoseconds by researchers at Science Tokyo, Tohoku University, and Nagoya Institute of Technology, Japan. By combining ultrafast laser spectroscopy with theoretical analysis, the researchers found that a transient electronic state plays a key role in this process. The findings provide new insights into controlling material properties with light for future applications.

A new liquid-based platform called “floatony” can form and maintain complex three-dimensional microbial structures without solidifying the surrounding medium, report researchers from Japan. Using a liquid drawing technique, the team suspended bacteria within a specially tuned “canvas solution,” achieving stable colonies that preserve molecular diffusion, spatial structures, and cell mobility. This approach could offer new ways to study gut microbiota, biofilms, and other spatially organized microbial communities.

Laser cutting is widely used in the manufacture of semiconductor chips and other precision electronic parts, as it can shape and cut materials without damaging the parts. However, laser cutting requires precision, and measuring the depth of the laser’s penetration during cutting remains challenging. Now, researchers from Chiba University have developed a simple yet effective monitoring technique that uses recoil forces to detect the processing depth and penetration of the laser in real time.

Our ability to see color comes from changes in proteins around the same retinal molecule in cone cells, which alter how it absorbs light. Unravelling the molecular mechanism of spectral tuning, Nagoya Institute of Technology researchers studied macaque cone pigments, which closely resemble human ones, and found that just three amino acid changes explain nearly all of the difference between red and green light detection. The findings show how small structural changes shape color vision.

Crystalline organic semiconductors offer excellent charge transport but have been difficult to incorporate into practical OLEDs. Researchers from the University of Toyama developed the first OLED using a non-epitaxial crystalline rubrene thin film. Using a two-step annealing process, they achieved 1,000-fold higher current density and a turn-on voltage of just 1.33 V. This breakthrough demonstrates that crystalline organic semiconductors can be integrated into practical OLEDs, paving the way for a "crystalline generation" of displays.

Kyoto, Japan -- Habit formation describes the repeated performance of a behavior until it becomes routine: in other words, the shift from deliberate to automatic decision-making. This concept is often invoked as a way to improve one's life by making a routine of beneficial activities that can otherwise feel tedious, such as cleaning, studying, and regular exercise.

That repeating the same behavior is essential for forming a habit has become well-established, but whether a habit develops as an exact replication of the original behavior, or if the behavior itself gradually changes as it becomes a habit, remains unclear. Because habit formation takes a long time, comparing behavioral and neural changes within the same subject before and after a habit develops has been difficult. To overcome this challenge, a team of researchers at Kyoto University developed a new training method that achieves rapid habit formation in mice, allowing them to track these transitions directly.

"Habits are one of the brain's most mysterious functions, and we often struggle to control them even though they are our own actions," says co-corresponding author Nozomi Asaoka. "By uncovering how habits work, we may eventually find ways to take control of them rather than letting them control us."