Strong emissions and aerosol formation potential of higher alkanes from diesel vehicles.

Higher alkanes are a major class of intermediate volatile organic compounds (IVOCs) emitted by vehicles, which have been considered as important precursors of secondary organic aerosol (SOA) in urban area. Dynamometer experiments were conducted to characterize emissions from gasoline and diesel vehicles in China. Three types of higher alkanes, namely acyclic, cyclic, and bicyclic alkanes, were explicitly quantified through the novel proton transfer reaction time-of-flight mass spectrometer with NO ionization (NO PTR-ToF-MS) with time response of 1 second.

Predictive biosignatures for hospitalization in patients with virologically confirmed COVID-19.

Background: COVID-19, caused by the SARS-CoV-2 virus, presents with varying severity among individuals. Both viral and host factors can influence the severity of acute and chronic COVID-19, with chronic COVID-19 commonly referred to as long COVID. SARS-CoV-2 infection can be properly diagnosed by performing real-time reverse transcription PCR analysis of nasal swab samples.

Biomechanical analysis of the tandem spinal external fixation in a multiple-level noncontiguous lumbar fractures model: a finite element analysis.

Objective: This study aimed to investigate the biomechanical characteristics of the tandem spinal external fixation (TSEF) for treating multilevel noncontiguous spinal fracture (MNSF) using finite element analysis and provide a theoretical basis for clinical application.

Methods: We constructed two models of L2 and L4 vertebral fractures that were fixed with the TSEF and the long-segment spinal inner fixation (LSIF). The range of motion (ROM), maximum stresses at L2 and L4 vertebrae, the screws and rods, and the intervertebral discs of the two models were recorded under load control.