Definition: In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
Input: Background: Respiratory protection effi ciency of facemasks is critically important in the battle against communicable respiratory infections such as infl uenza and severe acute respiratory syndrome (SARS). We studied the spatial distributions of simulated virus-laden respiratory droplets when human subjects wore facemasks and were exposed to regulatory viral droplets by conducting in vivo experiments in facemask use. Methods: Transmission pathway of aerosols of Fluorescein-KCl solution through facemasks and protective effi ciency of facemasks were examined by using normal surgical facemasks and two facemasks with exhaust valves (Facemask A) and exhaust holes (Facemask B) covered with the same surgical fi lters situated at the back of the facemasks. Fluorescein-KCl solution was sprayed onto the faces of participants wearing the facemasks and performing intermittent exercises on a treadmill in a climatic chamber. Results: Experimental results showed that when droplets spread onto a person face-to-face over short distances, 92.3% to 99.5% of droplets were blocked by the front surface of the facemask, whereas only 0.5% to 7.7% of droplets reached the back of the facemask. Both facemasks A and B had near or over 99% protection effi ciency, compared with that of 95.5% to 97% of surgical facemasks. Using the same fi lters as normal surgical masks, facemasks A and B provided more effective respiratory protection against communicable respiratory infections such as infl uenza and SARS by the location of the breathing pathway to the back of the facemasks. Conclusions: Separating the breathing pathway from the virus-contaminated area in facemasks can provide more effective protection against communicable respiratory infections such as infl uenza and SARS.

Transmission of communicable respiratory infections and facemasks