Publications by authors named "J G B Van Den Top"

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionu37grk9c4s0ucqlqkmcbmku0pch79fl1): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once