中文摘要：

目的观察和探讨人死后肝组织细胞激光共聚焦显微拉曼光谱的变化规律及其与死亡时间的关系。方法离体肝组织于死后48～72h内每隔4h提取样品,采用激光共聚焦显微拉曼光谱技术进行检测。观察800cm-1～3 200cm-1范围内检测样本特征峰的变化,指认其对应的化学基团,选择强度比值I1094/I2923作为响应值,并进行统计学计算。结果在48～72h内,随时间的延长,肝组织细胞主要散射峰峰位无明显变化,而其峰强度有明显差异;与核酸有关的峰（1 094cm-1）强度随时间推移有明显下降;与脂类有关的峰（1 454cm-1、2 923cm-1）强度变化不明显;各相对峰强（I1094/I2923）随死亡时间的推移而减小,并得到回归方程（r=0.914）。结论人死后肝组织细胞DNA降解随死亡时间延长呈下降趋势,I1094/I2923值与PMI呈负线性关系。激光共聚焦显微拉曼光谱技术有望成为推断死亡时间的检测方法。

英文摘要：

Objective To investigate the relationship between the variation of postmortem human liver tissue and postmortem interval（PMI） by laser confocal micro-Raman spectroscopy.Methods From 48 to 72 hours after death,samples of in vitro human liver tissues were collected every 4 hours and analyzed by laser confocal micro-Raman spectroscopy.In the wavelength ranging from 800cm-1 to 3 200cm-1,changes of characteristic peaks for test samples were observed,and the corresponding functional groups were identified,the intensity ratio of I1094/I2923 was chosen as a response value for statistical analysis.Results Within PMI between 48 to 72 hours,there was no significant change for the position of main scattering peaks of the liver tissue,but the intensity of these peaks have significant difference,and the intensity of the nucleic acid-related peak（1 094cm-1）descended obviously with the extension of PMI.The intensity of the lipid-related peaks（1 454cm-1,2 923cm-1）did not show significant change,but each relative peak intensity（I1094/I2923）reduced with time lapse,from which the regression equation was obtained（r=0.914）.Conclusions DNA content in hepatic cells decreases gradually with extension of PMI.There is a negative linear relationship between relative peak intensities I1094/I2923 and PMI.Laser Confocal Raman spectroscopy is expected to be a method for estimation of PMI.