id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
cord-271980-8x5g8r7c	Yao, Ye	Ambient nitrogen dioxide pollution and spread ability of COVID-19 in Chinese cities	2020-09-30		.txt	text/plain	3481	116	40	The relationship between NO 2 concentration and R 0 of COVID-19 may be mediated by population density or other air pollutants, such as city population and city area. To eliminate the effects of city population and city area on the relationship between NO 2 concentration and R 0 value, we applied a mediation analysis to verify whether more densely populated cities had both greater R 0 and NO 2 concentration values.	cache/cord-271980-8x5g8r7c.txt	txt/cord-271980-8x5g8r7c.txt
