Coral reefs are creeping away from the tropics in response to warming oceans, but the pace is too slow to beat the heat and escape impacts of climate change, according to a breakthrough study published June 6 in Science Advances. The study, authored by researchers at University of Hawaiʻi at Mānoa’s Hawaiʻi Institute of Marine Biology (HIMB) Marine Ecological Theory Lab, also offers a hopeful alternative: immediate actions to reduce greenhouse gas emissions can significantly improve the future outlook for coral reefs globally.

Recently, the team led by Academician Wei-Hong Zhu at East China University of Science and Technology proposed a novel photo-rearrangement reaction of diarylethenes induced by intramolecular proton transfer (IPT), while exploring the reactivity of active carbon sites in diarylethene systems. In this study, published in CCS Chemistry, aldehyde and carboxyl groups were innovatively introduced at the active carbon positions, revealing distinct photoresponsive behaviors. The dialdehyde-substituted system exhibited typical reversible photochromism, whereas the dicarboxylate-substituted counterpart underwent an unexpected photorearrangement to yield polycyclic aromatic structures. Mechanistic studies, including transient absorption spectroscopy and density functional theory (DFT) calculations, demonstrated that the rearrangement proceeds through electrocyclization followed by an IPT-driven decarboxylation process. This work opens a new pathway for light-induced synthesis of polycyclic aromatic hydrocarbons and highlights potential applications in molecular modification, photoreaction mechanisms, and synthetic photochemistry.

When visiting the dentist, you might remember being poked and prodded by a thin metal instrument to check your teeth and gums. This technique, called periodontal probing, is used to look for signs of gum disease. Now, researchers publishing in ACS Sensors report a toothbrush-shaped ultrasound transducer that can provide a less invasive screening for gum disease. In proof-of-concept demonstrations on animal tissues, the device produced measurements similar to those of a manual probe.

Co-packaged optics (CPO) technology requires reliable laser sources, either integrated or external, for operation. Since integrated laser sources are associated with reliability challenges, researchers are increasingly exploring CPO systems with external sources. Recently, polymer waveguides fabricated on glass-epoxy substrates have emerged as a reliable solution for transmitting laser signals from external sources to photonic circuits. Researchers from Japan have now demonstrated the suitability of these waveguides for use in CPO systems.