"COVID-19" . "Viral respiratory tract infections" . "Chlorides" . "RTT" . "Redox indicators" . "Occupational safety and health" . "Vital stains" . "Phenothiazines" . "Histology" . "Antidotes" . "Zoonoses" . "Dimethylamino compounds" . "Monoamine oxidase inhibitors" . "Thiazine dyes" . "World Health Organization essential medicines" .