Towards sustainable organic synthesis – Mechanochemistry replaces lithium with sodium in organic reactions
Peer-Reviewed Publication
Updates every hour. Last Updated: 8-Dec-2025 06:11 ET (8-Dec-2025 11:11 GMT/UTC)
Why does plastic turn brittle and paint fade when exposed to the sun for long periods? Scientists have long known that such organic photodegradation occurs due to the sun’s energy generating free radicals: molecules that have lost an electron to sunlight-induced ionization and have been left with an unpaired one, making them very eager to react with other molecules in the environment. However, the exact mechanisms for how and why the energy from the sun’s photons get stored and released in the materials over very long periods have eluded empirical evidence.
The problem lies in the timeframe. While scientists have access to extremely sophisticated spectroscopy equipment capable of measuring the energy levels of individual electrons at femtosecond to millisecond scales in organic materials, they have paid little attention to time scales beyond seconds – and these are processes that can take years.
As such, slow, transient charge accumulation has presented a disappointing data gap in both applied and theoretical optics. But now, researchers from the Organic Optoelectronics Unit at the Okinawa Institute of Science and Technology (OIST) have addressed this challenge with a new methodology that detects these faint signals. Their findings are published in Science Advances.
Poly(N-isopropylacrylamide) (PNIPAM) hydrogel undergoes significant but precise changes in size between 20 and 40 °C, making it an excellent candidate for use in variable-size deterministic lateral displacement (DLD) array devices. Researchers from Science Tokyo have built a tunable DLD cell-sorting platform and verified its ability to sort cancer cells of defined sizes from blood samples. This platform could offer high-resolution size-based cell sorting for a wide variety of biomedical applications
There is an important and unresolved tension in cosmology regarding the rate at which the universe is expanding, and resolving this could reveal new physics. Astronomers constantly seek new ways to measure this expansion in case there may be unknown errors in data from conventional markers such as supernovae. Recently, researchers including those from the University of Tokyo measured the expansion of the universe using novel techniques and new data from the latest telescopes. Their method exploits the way light from extremely distant objects takes multiple pathways to get to us. Differences in these pathways help improve models on what happens at the largest cosmological scales, including expansion.
Silver-based atomic switches that create stable electrical connections between individual molecules and electrodes have been developed by researchers from Japan, addressing a key challenge in wiring molecular electronics. The switch operates by forming and breaking silver atomic filaments when a voltage is applied and reversed, corresponding to the “on” and “off” states. This method enables the scalable integration of molecular components, paving the way for ultra-compact and energy-efficient circuits built from single molecules.