The simple face mask does not have a reservoir. The fraction of inspired oxygen is determined by the oxygen flow rate, the fit of the mask, and the patient’s minute ventilation. A face tent ...

The masks may represent a simple way to reduce TB transmissions ... and to allow patients to take medications. A mechanical ventilation system exhausted all ward air on alternating days to each ...

No matter the form of public transportation — planes, trains, trams, subways, buses or even rideshares — good ventilation can help reduce the spread of Covid-19, but masks work best.