$RLine = "R.N. Raox, J. Pure and Appl. Phys."; 
#Should not match -> Pattern OK

$RLine = "R.N. Raox, J. Pure text Appl. Phys."; 
#Should match -> Pattern OK

$RLine = "R.N. Raox, J. Pure and text Appl. Phys.";
#Should match but it is not -> Pattern NOT OK

$RLine = "R.N. and Raox, J. Pure text Appl. Phys.";
#Should match but it is not -> Pattern NOT OK