Alternatives for "conducted" with respect to research
Solution 1:
You actually can’t conduct a research, because it is not a count noun.
But you can conduct, do, pursue, guide, lead, head, preside over, or engage in research.
Other more courageous terms include chaperon, shepherd, and trailblaze.
Solution 2:
Can you use:
Scientists. . .
"studied"
"researched"
"evaluated"
"analyzed"
Solution 3:
Besides the suggestions offered already, you could look up synonyms of conduct in a thesaurus. This should give you candidates such as directed, performed, oversaw, etc.
Another alternative is to query a collocations database such as this one. Querying it with the string [v?d*] research
threw up words such as established, compiled, and pursued.