Effects of Hypoxic Prconditioning on Myocardial Ischemia/Reperfusion Injury---Roles of Hypoxia-Inducible Factor (HIF), Free Radicals, and Antioxidant System and a Functional Genomic Study by cDNA Microarray (I)=缺氧預處理的效用---缺氧預處理對心臟缺血/再灌注傷害的效用---HIF、自由基、及抗氧化系統的角色，及利用微矩陣的功能性基因體研究(I)