Apraisal of the diagnostic value of the gag reflex in patients with neurogenic oropharyngeal dysphagia.

Introduction: The gag reflex is a protection mechanism that prevents food and unwanted agents from entering the lower airways. It is usually part of the physical examination of swallowing to detect oropharyngeal dysphagia, but it is a potentially ambiguous sign.

Objective: To evaluate the diagnostic value of the gag reflex in patients with neurogenic oropharyngeal dysphagia and adults without it.

Evolution of the SARS-CoV-2 proteome in three dimensions (3D) during the first six months of the COVID-19 pandemic.

Three-dimensional structures of SARS-CoV-2 and other coronaviral proteins archived in the Protein Data Bank were used to analyze viral proteome evolution during the first six months of the COVID-19 pandemic. Analyses of spatial locations, chemical properties, and structural and energetic impacts of the observed amino acid changes in >48,000 viral proteome sequences showed how each one of the 29 viral study proteins have undergone amino acid changes. Structural models computed for every unique sequence variant revealed that most substitutions map to protein surfaces and boundary layers with a minority affecting hydrophobic cores.