(S (S (SBAR (IN Since) (S (VP (VBG being) (VP (VBN admitted) (PP (TO to) (BASENP (DT the) (NN hospital))))))) (COMMA ,) (S (BASENP (PRP he)) (VP (VBZ has) (VP (VP (VP (VBN undergone) (NP (BASENP (JJ several) (NNS rounds)) (PP (IN of) (BASENP (NN surgery))))) (PP (IN on) (BASENP (PRPD his) (NN brain)))) (PP (IN in) (NP (BASENP (DT an) (NN attempt)) (SBAR (S (VP (TO to) (VP (VB stop) (BASENP (NN bleeding)))))))))))) (PERIOD .))