温度对死后大鼠肾组织FTIR光谱特征的影响

Effects of Temperature on FTIR Spectral Characteristics of Renal Tissue in Rats after Death

目的分析大鼠死后肾组织在不同温度下的傅里叶变换红外(Fourier transform infrared,FTIR)光谱数据,探究温度对死后大鼠肾组织FTIR光谱特征的影响。方法大鼠颈椎脱臼处死后置于4℃、20℃和30℃环境中,于不同时间点提取大鼠肾组织,采集FTIR光谱数据,并利用数据挖掘技术对数据进行分析。结果 4℃、20℃和30℃环境组中部分时间点样本主成分分析结果具有明显聚类趋势。分别利用三个温度组光谱数据建立偏最小二乘(partial least square,PLS)回归模型,结果 20℃和30℃组数据的PLS回归模型性能均优于4℃组,20℃组模型稳定性优于30℃组。结论大鼠死后肾组织在不同温度下的FTIR光谱特征具有差异,温度对FTIR光谱PLS回归模型性能具有重要影响,因此在利用光谱法推断死亡时间的研究中需要考虑温度对模型的影响,以提高死亡时间推断的准确性。

Objective To analyse the Fourier transform infrared（FTIR） spectral data of renal tissue at different temperatures in rats after death,and to explore the effects of temperature on the FTIR spectral characteristics of renal tissue.Methods The rats were sacrificed by cervical dislocation and placed at 4 ℃,20 ℃ and 30 ℃.The FTIR spectral data of renal tissue were collected at different time points and analysed by data mining method.Results The principal component analysis（PCA） results showed that there were significant trends of clustering in the samples of partial time point at 4 ℃,20 ℃ and 30 ℃.Partial least square（PLS） regression models were established with the spectral data at three temperature groups.The performance of PLS regression models in 20 ℃ and 30 ℃ groups were more superior than that in 4 ℃group,and the stability of the model in 20 ℃ group was better than that in 30 ℃ group.Conclusion There are differences in the FTIR spectral characteristics of renal tissue of rats after death at different temperatures.Temperature has a major impact on the performance of FTIR spectral PLS regression model.Therefore,in order to improve the accuracy of postmortem interval estimation,the effects of temperature on the model should be considered in the related study by spectral method.