We quantified eight parent volatiles (H2O, C2H6, HCN, CO, CH3OH, H2CO, C2H2, and CH4) in the Jupiter-family comet Tempel 1 using high-dispersion infrared spectroscopy in the wavelength range 2.8 to 5.0 micrometers. The abundance ratio for ethane was significantly higher after impact, whereas those for methanol and hydrogen cyanide were unchanged. The abundance ratios in the ejecta are similar to those for most Oort cloud comets, but methanol and acetylene are lower in Tempel 1 by a factor of about 2. These results suggest that the volatile ices in Tempel 1 and in most Oort cloud comets originated in a common region of the protoplanetary disk.
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http://dx.doi.org/10.1126/science.1119337 | DOI Listing |
JAMA Netw Open
January 2025
Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego.
Importance: The degree that in-home cannabis smoking can be detected in the urine of resident children is unclear.
Objective: Test association of in-home cannabis smoking with urinary cannabinoids in children living at home.
Design, Setting, And Participants: This cross-sectional study used baseline data from Project Fresh Air, a 2012-2016 randomized clinical trial to reduce fine particulate matter levels.
J Chromatogr B Analyt Technol Biomed Life Sci
January 2025
Christina Lee Brown Envirome Institute, University of Louisville, Louisville, KY 40202, United States; Superfund Research Center, University of Louisville, Louisville, KY 40202, United States; Division of Environmental Medicine, Department of Medicine, University of Louisville, Louisville, KY 40202, United States. Electronic address:
Human exposure to volatile organic compounds (VOCs) poses significant health risks, contributing to cardiovascular disease, pulmonary disease, and cancer. Measurement of VOC metabolites (VOCm) in urine by liquid chromatography-mass spectrometry (LC-MS) is a preferred method for VOCm analysis; however, existing methods encounter challenges related to sensitivity, throughput, and analyte coverage. In addition to VOCm, the measurement of tobacco alkaloids (TAm) is critical to account for tobacco use in population-based studies.
View Article and Find Full Text PDFBMC Plant Biol
January 2025
State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
Thyme and oregano essential oils (EOs) and their components have numerous applications in the pharmaceutical, food, and cosmetic industries owing to their antioxidant, antibacterial, antifungal, anti-inflammatory, antiviral, and immunological properties. We attempted to create new chemotypes through the hybridization of thyme and oregano for functional EO research and product development. Here, we used interspecific hybridization to create new thyme and oregano germplasms with new EO chemotypes.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Child Healthcare, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Hospital), Tongji Medical College, Huazhong University of Science and Technology, 100 Hongkong Road, Wuhan, 430016, Hubei, China.
The gut microbiome and its metabolites may be important role in regulating the pathogenesis of obesity. This study aimed to characterize the gut microbiome and short-chain fatty acid (SCFA) metabolome in obese children. This case-control study recruited children aged 7‒14 years and divided them into a normal group (NG) and an obese group (OG) based on their body mass index.
View Article and Find Full Text PDFNat Commun
December 2024
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China.
Recent advances have uncovered an exotic sliding ferroelectric mechanism, which endows to design atomically thin ferroelectrics from non-ferroelectric parent monolayers. Although notable progress has been witnessed in understanding the fundamental properties, functional devices based on sliding ferroelectrics remain elusive. Here, we demonstrate the rewritable, non-volatile memories at room-temperature with a two-dimensional (2D) sliding ferroelectric semiconductor of rhombohedral-stacked bilayer MoS.
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