线性判别分析

解吸电喷雾质谱对氰基丙烯酸酯处理指纹图谱中安全套润滑剂的分类

ty10086 提交于 周四, 08/26/2021 - 13:11
摘要\n指纹中的安全套润滑剂痕迹可以成为性侵犯案件的宝贵信息。理想情况下,不仅可以确认安全套的存在,还可以确定使用的安全套品牌的类型。先前的研究表明,可以通过各种分析技术从含有润滑剂的指纹中检索有关安全套品牌和类型的信息。然而,在实际应用中,指纹往往会出现潜伏性,需要首先检测,这往往是通过氰基丙烯酸酯发烟来实现的。本研究发展了一种脱附电喷雾质谱( DESI-MS )方法,该方法结合主成分分析和线性判别分析( PCA- LDA ),可从含有安全套润滑剂痕迹的指纹中对安全套品牌和类型进行高精度分类。开发的方法与氰基丙烯酸酯( CA )发烟兼容。我们收集并分析了荷兰有代表性的数据集,其中包括32种不同的避孕套。采用DESI-MS法容易检测到聚乙二醇( PEG )、聚二甲基硅氧烷( PDMS )、辛氧醇-9和壬氧醇-9等独特的润滑剂组分。通过对润滑油斑点的分析,达到了99.0 %的分类精度。在分析含有指纹的润滑剂时,总体精度达到90.9 %。可以从指纹中生成完整的化学图像,显示润滑剂组分如PEG和PDMS在整个指纹中的分布,同时仍然允许分类。该方法有望发展基于DESI-MS的CA处理指纹外源性化合物分析方法,用于法医学研究。

Rapid detection of sepsis in rats through volatile organic compounds in breath.

ty10086 提交于 周四, 08/26/2021 - 12:58
Sepsis is one of the main causes of death in adult intensive care units. The major drawbacks of the different methods used for its diagnosis and monitoring are their inability to provide fast responses and unsuitability for bedside use. In this study, performed using a rat sepsis model, we evaluate breath analysis with Ion Mobility Spectrometry (IMS) as a fast, portable and non-invasive strategy.;This study was carried out on 20 Sprague-Dawley rats. Ten rats were injected with lipopolysaccharide from Escherichia coli and ten rats were IP injected with regular saline.