Saturn's main rings are composed of >95% water ice, and the nature of the remaining few percent has remained unclear. The Cassini spacecraft's traversals between Saturn and its innermost D ring allowed its cosmic dust analyzer (CDA) to collect material released from the main rings and to characterize the ring material infall into Saturn. We report the direct in situ detection of material from Saturn's dense rings by the CDA impact mass spectrometer. Most detected grains are a few tens of nanometers in size and dynamically associated with the previously inferred "ring rain." Silicate and water-ice grains were identified, in proportions that vary with latitude. Silicate grains constitute up to 30% of infalling grains, a higher percentage than the bulk silicate content of the rings.
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http://dx.doi.org/10.1126/science.aat3185 | DOI Listing |
Chemistry
January 2025
Osaka Metropolitan University: Osaka Koritsu Daigaku, Chemistry, 3-3-138 Sugimoto, Sumiyoshi-ku, 558-8585, Osaka, JAPAN.
Gold(I)-catalyzed intramolecular hydroarylation of dialkynyl(biaryl)phosphine oxides provided versatile benzo-fused phosphepine oxides. O-exo adducts were obtained as the major product, and O-endo adducts were the minor product. O-exo and O-endo indicate the position of an oxygen atom with respect to the central phosphepine framework.
View Article and Find Full Text PDFCell
January 2025
Department of Molecular Sociology, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany; Institute of Biochemistry, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany. Electronic address:
Upon infection, human immunodeficiency virus type 1 (HIV-1) releases its cone-shaped capsid into the cytoplasm of infected T cells and macrophages. The capsid enters the nuclear pore complex (NPC), driven by interactions with numerous phenylalanine-glycine (FG)-repeat nucleoporins (FG-Nups). Whether NPCs structurally adapt to capsid passage and whether capsids are modified during passage remains unknown, however.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
State Key Laboratory of Biobased Fiber Manufacturing Technology, China Light Industry Key Laboratory of Papermaking and Biorefinery, Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin 300457, China. Electronic address:
Exploring innovative and sustainable routes for the production of biodegradable biomass-based materials is critical to promote a circular carbon economy and carbon neutrality goals. Fossil-based non-biodegradable plastic waste poses a nonnegligible threat to humans and the ecological environment, and biomass-based functional materials are becoming increasingly viable alternatives. Lignin, a naturally occurring macromolecular polymer, is green and renewable resource rich in aromatic rings, with biodegradability, biocompatibility, and excellent processability for eco-friendly composites.
View Article and Find Full Text PDFArch Sex Behav
January 2025
School of Kinesiology and Health Science, 301F Stong College, York University, 4700 Keele St., Toronto, ON, Canada.
Critiques from queer theory have suggested that the legalization of same-sex marriage (SSM) predominantly benefits White, middle-class segments of the lesbian, gay, and bisexual (LGB) community. This study investigates the impact of the legalization of SSM on mental health among Black LGB individuals, focusing on those with lower incomes in the UK. Using a nationally representative panel sample and employing a quasi-experimental methodology, we analyzed changes in psychological distress and life dissatisfaction following the legalization of SSM.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
December 2024
Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences Beijing 100700, China.
This study aimed to investigate the potential role of Colquhounia Root Tablets against bone destruction in rheumatoid arthritis(RA) and its molecular mechanism. The study used ultra-performance liquid chromatography-mass spectrometry to analyze the major components of Colquhounia Root Tablets and predicted its candidate target gene set based on the major components. The key targets of RA bone destruction were obtained through GeneCards and the Database of Genetics and Medical Literature(OMIM), protein-protein interaction(PPI) network was constructed, and the key targets were identified by topological analysis.
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