Effects of Relative Humidity on Time-Resolved Molecular Characterization of Secondary Organic Aerosols from the OH-Initiated Oxidation of Cresol in the Presence of NO.

While biomass burning (BB) is the largest source of fine particles in the atmosphere, the influence of relative humidity (RH) and photochemistry on BB secondary organic aerosol (BB-SOA) formation and aging remains poorly constrained. These effects need to be addressed to better capture and comprehend the evolution of BB-SOA in the atmosphere. Cresol (CHO) is used as a BB proxy to investigate these effects.

Photodegradation of naphthalene-derived particle oxidation products.

While photochemical aging is known to alter secondary organic aerosol (SOA) properties, this process remains poorly constrained for anthropogenic SOA. This study investigates the photodegradation of SOA produced from the hydroxyl radical-initiated oxidation of naphthalene under low- and high-NO conditions. We used state-of-the-art mass spectrometry (MS) techniques, including extractive electrospray ionization and chemical ionization MS, for the in-depth molecular characterization of gas and particulate phases.

Gut microbiome and immune checkpoint inhibitor toxicity.

Background: Multiple studies have suggested that gut microbiome may influence immune checkpoint inhibitor (ICI) efficacy, but its association with immune-related adverse events (irAEs) is less well studied. In this prospective cohort study, we assessed whether gut microbiome composition at start, or changes during ICI, are associated with severe irAEs.

Methods: Stool samples of cancer patients treated with anti-PD-1 ± anti-CTLA-4 were analyzed using 16S rRNA gene sequencing and metagenomic shotgun sequencing.

Omnigene-Gut ensures fecal microbiome stability in the pediatric population.

Increasing evidence exists that the gut microbiome influences toxicity as well as outcomes in a variety of cancers. To investigate the role of the gut microbiome in pediatric neuro-oncology, microbiome analysis has been included in multiple prospective pediatric neuro-oncology clinical trials (NCT05009992, NCT04732065, NCT04775485). In these trials, the OMNIgene-GUT preservation tubes are used for the collection of the feces.

New particle formation from isoprene under upper-tropospheric conditions.

Aircraft observations have revealed ubiquitous new particle formation in the tropical upper troposphere over the Amazon and the Atlantic and Pacific oceans. Although the vapours involved remain unknown, recent satellite observations have revealed surprisingly high night-time isoprene mixing ratios of up to 1 part per billion by volume (ppbv) in the tropical upper troposphere. Here, in experiments performed with the CERN CLOUD (Cosmics Leaving Outdoor Droplets) chamber, we report new particle formation initiated by the reaction of hydroxyl radicals with isoprene at upper-tropospheric temperatures of -30 °C and -50 °C.