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Rapid Commun Mass Spectrom
April 2025
Solar System Exploration Division, NASA Goddard Space Center, Greenbelt, Maryland, USA.
Rationale: Extraterrestrial amines and ammonia are critical ingredients for the formation of astrobiologically important compounds such as amino acids and nucleobases. However, conventional methods for analyzing the composition and isotopic ratios of volatile amines suffer from lengthy derivatization and purification procedures, high sample mass consumption, and chromatographic interferences from derivatization reagents and non-target compounds.
Methods: Here we demonstrate a highly efficient method to analyze the composition and compound specific isotopic ratios of C to C amines as well as ammonia based on solid phase micro-extraction (SPME) on-fiber derivatization.
Otol Neurotol
February 2025
Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
Background Introduction: Vestibular schwannoma (VS) tumors typically present with sensorineural hearing loss (SNHL). Losartan has recently demonstrated prevention of tumor-associated SNHL in a mouse model of VS through suppression of inflammatory and pro-fibrotic factors, and the current study investigates this association in humans.
Methods: This is a retrospective study of patients with unilateral VS and hypertension followed with sequential audiometry at a tertiary referral hospital from January 1994 to June 2023.
Chem Soc Rev
January 2025
Department of Chemistry, Purdue University, West Lafayette, Indiana, 47906, USA.
The light-absorbing chemical components of atmospheric organic aerosols are commonly referred to as Brown Carbon (BrC), reflecting the characteristic yellowish to brown appearance of aerosol. BrC is a highly complex mixture of organic compounds with diverse compositions and variable optical properties of its individual chromophores. BrC significantly influences the radiative budget of the climate and contributes to adverse air pollution effects such as reduced visibility and the presence of inhalable pollutants and irritants.
View Article and Find Full Text PDFACS Earth Space Chem
December 2024
Université Paris-Est Créteil and Université Paris Cité, CNRS, LISA, Créteil F-94010, France.
Hydroxyacetone (HA) is an atmospheric oxidation product of isoprene and other organic precursors that can form brown carbon (BrC). Measured bulk aqueous-phase reaction rates of HA with ammonium sulfate, methylamine, and glycine suggest that these reactions cannot compete with aqueous-phase hydroxyl radical oxidation. In cloud chamber photooxidation experiments with either gaseous or particulate HA in the presence of the same N-containing species, BrC formation was minor, with similar mass absorption coefficients at 365 nm (<0.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Chemistry, University of Helsinki, FI-00014 Helsinki, Finland.
Quantum chemical calculations were employed to construct Jablonski diagrams for a series of phenolic carbonyls, including vanillin, iso-vanillin, 4-hydroxybenzaldehyde, syringaldehyde, and coniferyl aldehyde. These molecules can enter the Earth's atmosphere from forest fire emissions and participate in photochemical reactions within the atmospheric condensed phase, including cloud and fog droplets and aqueous aerosol particles. This photochemistry alters the composition of light-absorbing organic content, or brown carbon, in droplets and particles through the formation and destruction of key chromophores.
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