献礼春节中科白癜风帮扶 http://pf.39.net/bdfyy/bdfyc/171121/5863544.html基于ATR-FTIR光谱技术研究血痕形成的时序性变化
Studyonthetime-dependentchangesofbloodstainformationusingATR-FTIRspectroscopy
吴雪梅王琪2陈卫平张更,4.福建医科大学基础医学院人体解剖学系2.重庆医科大学基础医学院法医学系.重庆市法医学会司法鉴定所4.福建医科大学临床应用解剖学研究室
摘要:目的应用衰减全反射-傅里叶变换红外(ATR-FTIR)光谱技术,研究血痕形成过程中主要化学基团的变化趋势,为今后构建血痕形成时间推断模型建立实验基础。方法采6例人体外周血样,各取滴从0cm高处滴于ATR探头,每0min采集一次FTIR光谱数据,共持续72h。运用Matlaba软件分析光谱数据,分别对主要吸收峰的吸光度值、峰面积值(x)和血痕形成时间(y)进行拟合。结果血痕形成大致可以分为两个阶段,血液干涸阶段(0-40min)和血痕形成阶段(40min)。第二个阶段,主要吸收峰峰形稍有改变,但峰位没有明显变化。不同吸收峰吸光度值随时间变化趋势较差;而对应峰面积值变化趋势较好,且多符合对数函数变化规律。结论血痕形成FTIR光谱分析,吸收峰的峰面积优法于吸光度法。绝大多数化学基团不断分解,主要呈先快后慢趋势;不同物质分解速率不同,同一物质不同基团、同一基团不同振动类型变化趋势亦不相同。其中,64、57、及cm-吸收峰降解趋势较为规律。
关键词:
法医学;ATR-FTIR;光谱;血痕;时序性变化;
ObjectiveTostudythetime-dependentchangesofmainchemicalgoupsintheprocessofbloodstainformationwithattenuatedtotalreflection–Fouriertransforminfrared(ATR-FTIR)spectroscopictechnology,andtoestablishtheexperimentalandtheoreticalbasisforconstructingrelativelyaccurateandreliabletimeinferencemathematicalmodelofbloodstainformation.MethodsOnedropofblood,respectivelyfromsixhealthyadultvolunteers,wasdroppeddirectlyontotheATRcrystalfrom0cmheight.TheFTIRspectrawererecordedevery0minutes,72h.total.Matlabawasusedtoanalyzethespectroscopicdata.Thedifferentabsorbanceorareasofpeakswerecalculated.Thecurveestimationanalysisbetweenabsorbanceorareasofpeaks(x)andtimeofbloodstainformation(y)wereperformedtoestablishmathematicalmodels.ResultsTheprocessofbloodstainformationcanberoughlydividedintothedrying(0-40min)andtheformationstage(40min).Inthesecondstage,theshapeofdifferentabsorptionpeakschangedwithpositionunchanged.Theareasofabsorbancepeakconformtotheruleoflogarithmicfunction,andworkbetterthantheabsorbancevalues.ConclusionsThespectraofbloodstainformationcouldbeinterferedbytheenvironment.Majoritychemicalgroupsinthebloodstainde
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