Danaher Corp. has completed the $21.4 billion acquisition of General Electric’s Healthcare Life Sciences division. Under Danaher's ownership, the business will be called Cytiva, loosely based on the Greek word for "cell." Cytiva is already ramping up hiring locally, with plans to add 40 to 50 jobs at its operations in Westborough and Marlborough, according to Cytiva president Emmanuel Ligner.