Find the number of papers published by authors from the institution "Tokohu University".
SELECT count(DISTINCT t1.title) FROM papers AS t1 JOIN authorship AS t2 ON t1.paperid  =  t2.paperid JOIN inst AS t3 ON t2.instid  =  t3.instid WHERE t3.name  =  "Tokohu University"
"Tohoku Üniversitesi" kurumundan yazarlar tarafından yayınlanan makalelerin sayısını bulun.