ABSTRACT
An epidemiological investigation was carried out on a local cluster of outbreak caused by imported cases of Coronavirus Disease 2019 (COVID-19) in rural areas of Chengdu in December 2020, to find out the source of infection and the chain of transmission. According to
Subject(s)
Humans , COVID-19 , Disease Outbreaks , Epidemics , Quarantine , SARS-CoV-2ABSTRACT
Objective To detect the DNA damage of ras gene induced by organic concentrate of drinking water using randomized terminal linker-dependent PCR. Methods The single-stranded probes of exons of rass gene in human were prepared. The TK6 cell was treated with organic concentrate of drinking water, then genomic DNA was amplified by RDPCR and detected by Southern hybridization with the probe. Results The clear hybridized band induced by organic concentrate of tap water could be seen in the position of exon 2 of N-ras gene,but in those of exon 1 of N-ras, exon 1 and 2 of H-ras gene it could not be detected. No hybridized bands induced by organic concentrate of raw water were seen in any position. Conclusion The organic concentrate of drinking water can cause the DNA damage of ras gene and it is considered as a kind of genotoxic substance.