zcat ${sample}_R1.fastq.gz |sed -e '4~4y/KLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~/""""""""""""""""""""""""""""""""""""""""""""""""""""/' |gzip >${sample}_R1.fixed.fastq.gz &
zcat ${sample}_R2.fastq.gz |sed -e  '4~4y/KLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~/""""""""""""""""""""""""""""""""""""""""""""""""""""/' |gzip >${sample}_R2.fixed.fastq.gz & 
wait