Kyoto, Japan -- The space around Earth is becoming increasingly crowded, with thousands of satellites and pieces of debris now sharing low Earth orbit. Even above this region -- at altitudes of several hundred kilometers -- the extremely thin upper atmosphere can slow satellites down, making accurate information on atmospheric density essential for predicting satellite motion and preventing collisions.

The upper atmosphere is composed of more than 99 percent electrically neutral atmosphere called the thermosphere, and thermospheric density is the term used to describe neutral atmospheric density at heights from 100 to 1000 kilometers above the Earth's surface. While the ionized gas of the ionosphere makes up less than 1 percent of the atmosphere, the effect of the ionized gas on radio wave propagation renders the ionosphere relatively easy to observe, while thermospheric observations pose a considerable challenge.

Nonetheless, developing observation methods for thermospheric density is essential both to further advancing the science of the upper atmosphere and for applications in space engineering. These needs inspired a team of researchers at Kyoto University to develop a new method of visualizing this elusive environment.

Per- and polyfluoroalkyl substances and plastic particles may not drift through the bloodstream alone. The working hypothesis is that they bind lipids and proteins, forming aggregates that persist for years. A team at Technische Universität Dresden asked whether therapeutic apheresis, an extracorporeal therapy developed to strip lipoproteins from patients with severe dyslipidemia, also removes such contaminants. In small exploratory cohorts, PFAS and micro- and nanoplastic levels decreased in patient blood after double filtration plasmapheresis, with PFAS detectable in the discarded eluate. Raman spectroscopy located plastic particles inside human skin. Responses varied across individuals and analytes, and the mechanism remains unknown.

Carbon fixation continues through winter

A paper published in Carbon Research reports that microbial inorganic carbon fixation remains active in Qinghai Lake, the largest saline lake in China, during the ice-covered season. The work focuses on how microorganisms assimilate inorganic carbon beneath lake ice, a period that has received far less attention than the summer open-water season despite its importance for annual lake carbon cycling.

The team, led by corresponding author Xiaoyan Li of Beijing Normal University, examined both light-dependent carbon fixation and dark-dependent carbon fixation in under-ice waters. Qinghai Lake, located on the Tibetan Plateau, provides a natural setting for this question because it is a high-altitude saline lake with prolonged seasonal ice cover, low temperatures, and distinctive microbial habitats.

Halide-based solid electrolytes (HSEs) have garnered substantial interest for all-solid-state batteries (ASSBs) due to their wide electrochemical windows, moderate-to-high room-temperature ionic conductivity, and enhanced air stability over traditional sulfide and oxide-based SEs. This review consolidates recent advances in HSEs, focusing on the link between structure, compositions, and materials properties that influence the transport of lithium-ion (Li-ion) and post-lithium-ion (P-Li-ion) and their stability at the interface. Based on the chemistry of their central metal, HSEs are divided into five classes; key factors influencing ionic conductivity are examined. Nevertheless, despite these benefits, many challenges remain, including interfacial instability, the trade-off between ionic conductivity and electrochemical stability, mechanical challenges, and material costs. The main synthesis methods, mechanochemical, co-melting, and wet-chemical, are investigated for phase formation, scalability, and defect control. The link between synthesis, microstructure, and device-level performance metrics, including critical current density, area-specific resistance, and cycle life, is examined. The strategies, involving bilayer and dual-electrolyte design as well as interface engineering, are analyzed to reduce interfacial resistance and dendrite growth. The applications of HSE in Li-ion and P-Li-ion systems are examined. This review offers a detailed framework and delineates potential research paths to advance scalable, high-performance HSEs for next-generation ASSBs.

Researchers from Zhejiang University and Northeast Forestry University have developed an exhalation-responsive optoelectronic clip that turns human breath into a clear optical ON/OFF signal. The wearable device combines optical microfibers with nanocellulose films and can be used for touch-free alerts, coded communication, and respiratory monitoring.