This study is about using mass spectrometry to measure thousands of metabolites in patients' plasma to screen biomarkers for intravenous thrombolysis eligibility in ischemic stroke patients with unknown time pf onset. The dada uploaded here consists the clinical characteristics of patients and the metabolites detected in their blood. IS means acute ischaemic stroke. ES means early IS with onset time within 4.5h. LS means late IS with onset time >4.5h.