Abstract：
Establishing a correlation between environmental variables and chemical change can significantly improve the quality of research in multiple fields. Among various environmental variables, temperature and humidity are closely related to the rate of chemical reactions. This study aimed to confirm changes in metabolite markers that were previously discovered in other temperature and humidity environment conditions and to confirm the possibility that they could act as markers. After blood collection from the subjects and bloodstain preparation, the quantitative values of the bloodstain metabolites were confirmed (when the age of the bloodstain was within a month) under eight environmental conditions (4 °C/30%, 4 °C/60%, 25 °C/30%, 25 °C/60%, 25 °C/90%, 40 °C/30%, 40 °C/60%, and 40 °C/90%). Age-of-bloodstain estimation models were constructed to confirm the applicability of bloodstain metabolites as markers for bloodstain age in various environments. The average concentration of metabolite markers exhibited a decreasing trend with the age of the bloodstain, which transformed into an increasing trend from day 7 onwards. In terms of temperature and humidity, 25 °C and 90%, respectively, showed the most dissimilar metabolite change pattern compared to other conditions. The age-of-bloodstain estimation models developed here have an R-square value of up to 0.92 for each condition and an R-square value of 0.71 when all environmental conditions were combined. The findings herein highlight the immense potential of blood metabolites for field application, confirming the possibility of predicting metabolite changes from the rates of their chemical reactions and validating the importance of metabolites as age-of-bloodstain markers under various environmental conditions.
摘要：
在环境变量和化学变化之间建立相关性可以显着提高多个领域的研究质量。在各种环境变量中，温度和湿度与化学反应的速率密切相关。这项研究旨在确认以前在其他温度和湿度环境条件下发现的代谢物标记的变化，并确认它们可以作为标记的可能性。在从受试者收集血液和血迹制备后，在八种环境条件（4°C/30％，4°C/60%,25°C/30%,25°C/60%,25°C/90%,40°C/30%,40°C/60%,和40°C/90%)。建立了血迹年龄估计模型，以确认血迹代谢物在各种环境中作为血迹年龄标记的适用性。代谢物标记物的平均浓度随着血迹的年龄呈现下降趋势,从第7天开始转变为增长趋势。在温度和湿度方面，25°C和90%，分别,与其他条件相比，显示出最不同的代谢物变化模式。此处开发的血迹年龄估计模型在每种条件下的R平方值均高达0.92，在组合所有环境条件时的R平方值为0.71。本文的发现突出了血液代谢物在现场应用的巨大潜力，确认从其化学反应速率预测代谢物变化的可能性，并验证在各种环境条件下代谢物作为血迹年龄标记物的重要性。
