PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • Femtosecond lasers, so-called because they deliver ultrafast pulses of light per quadrillionths of a second (a femtosecond), have long been used in optic surgeries to correct conditions such as nearsightedness, farsightedness and astigmatism.
http://www.w3.org/ns/prov#wasQuotedFrom
  • lef.org