Hierarchical Cluster Analysis of Ignitable Liquids Based on the Total Ion Spectrum

Gas chromatography–mass spectrometry (GC–MS) data of ignitable liquids in the Ignitable Liquids Reference Collection (ILRC) database were processed to obtain 445 total ion spectra (TIS), that is, average mass spectra across the chromatographic profile. Hierarchical cluster analysis, an unsupervised learning technique, was applied to find features useful for classification of ignitable liquids. A combination of the correlation distance and average linkage was utilized for grouping ignitable liquids with similar chemical composition. This study evaluated whether hierarchical cluster analysis of the TIS would cluster together ignitable liquids of the same ASTM class assignment, as designated in the ILRC database. The ignitable liquids clustered based on their chemical composition, and the ignitable liquids within each cluster were predominantly from one ASTM E1618‐11 class. These results reinforce use of the TIS as a tool to aid in forensic fire debris analysis.     

利用RASSF1A位点检测母体血浆中胎儿SNP分型

目的探讨利用母体血浆中高甲基化RASSF1A位点进行胎儿SNP分型的应用价值。方法随机收集10个未孕健康妇女和45例不同孕期（早期5例、中期20例、晚期20例）孕妇的血样本及相应胎儿组织（绒毛组织、羊水、胎盘组织）;利用甲基化敏感限制性内切酶BstUI酶切后进行PCR,产物进行血细胞、血浆和胎儿组织（绒毛或胎盘）DNA RASSF1A序列的甲基化模式检测,并采用直接测序法对SNP rs4688725位点进行分型。结果经BstUI酶消化,RASSF1A序列在母体血细胞中均未检出,而在绒毛或胎盘组织中均能检出;在45名孕妇血浆中,RASSF1A序列均能被检出,且序列内的SNP分型与相应胎儿组织一致;在10名非孕妇女血浆中均未检出RASSF1A序列。结论母体和胎儿DNA中RASSF1A基因启动子区域的甲基化模式存在差异,可用于对母体血浆中的游离胎儿DNA进行SNP分型。     

紫外分光光度法和二阶导数光谱法测定水样中的敌草快

目的建立测定水样中的敌草快的分析方法。方法采用紫外分光光度法和二阶导数光谱法测定水样中的敌草快。结果紫外分光光度法直接测定水样中的敌草快,在0.1~50μg/mL范围内线性关系良好,日内,日间精密度均小于2.6%。二阶导数光谱法在0.1~10μg/mL线性关系良好,日内、日间精密度均小于1.29%。结论该两种方法快速、简单、灵敏,适用于环境监测工作。     

STRtyper-10G系统9个STR基因座突变分析

目的观察和分析STRtyper-10G系统9个STR基因座的突变特点。方法在7 707例肯定亲子关系的案件中,统计使用STRtyper-10G试剂盒（9个STR基因座）检测发现的突变事件,判断突变等位基因的来源,计算各基因座的突变率,分析突变特点。结果在9个基因座上共发现118个突变事件,均为1步突变;平均突变率为1.69×10-3（95%CI 1.40×10-3~2.03×10-3）,各基因座的突变率介于0.78×10-3~2.84×10-3,父、母来源突变比例为9.64∶1;短、中、长等位基因的突变比值约为1∶8∶3,增加和减少重复单位的突变比值为1.29∶1。结论 9个基因座的突变率存在显著差异,实际检案时应结合各基因座的突变率进行PI值计算更为科学。     

实时荧光定量PCR检测羊肉制品中鼠源性成分

目的建立基于实时荧光PCR技术的肉制品中鼠源性成分的快速检测方法。方法以羊和鼠的细胞色素b基因序列设计特异性引物和Taqman荧光探针,通过特异性、灵敏性及模拟混合肉样检测实验,建立羊肉制品中鼠源性成分实时荧光定量PCR检测方法。结果该检测方法具有良好的特异性和灵敏度,在50mg羊肉和鼠肉的混合样品检测中,鼠源性成分检测限可低至1%。结论所建立的鼠源性成分检测的实时荧光定量PCR方法,为肉制品质量控制提供了有效的技术手段,弥补了利用RTi-PCR检测肉制品中鼠源性成分的技术空白。     

对做好民族地区群众工作的思考

党的宗旨是全心全意为人民服务。做好民族地区群众工作是践行党的宗旨的需要,是维护国家边疆稳定的需要,是促进民族地区科学发展,维护各族人民利益的需要。本文在分析民族地区群众工作面临新挑战的基础上。提出了做好民族地区群众工作的对策。     

The Church,Ethnonationalism, and the State

Although the process of the acquisition of independence by countries and large ethnic groups in the post-Soviet region and the Eastern Bloc as a whole is complete, over the next few decades Churches are hardly likely to become propagandists of peace and tolerance.     

Infrared Spectra of U.S. Automobile Original Finishes (Post – 1989). VIII: In Situ Identification of Bismuth Vanadate Using Extended Range FT‐IR Spectroscopy,Raman Spectroscopy,and X‐Ray Fluorescence Spectrometry

Chrome Yellow (PbCrO₄·xPbSO₄) was a common pigment in U.S. automobile OEM finishes for more than three decades, but in the early 1990s its use was discontinued. One of its main replacements was Bismuth Vanadate (BiVO₄·nBi₂MoO₆, n = 0–2), which was commercially introduced in 1985, as this inorganic pigment also produces a very bright hue and has excellent outdoor durability. This paper describes the in situ identification of Bismuth Vanadate in automotive finishes using FT‐IR and dispersive Raman spectroscopy and XRF spectrometry. Some differentiation of commercial formulations of this pigment is possible based on far‐infrared absorptions, Raman data, and elemental analysis. The spectral differences arise from the presence or absence of molybdenum, the use of two crystal polymorphs of BiVO₄, and differences in pigment stabilizers. Bismuth Vanadate is usually not used alone, and it is typically found with Isoindoline Yellow, hydrous ferric oxide, rutile, Isoindolinone Yellow 3R, or various combinations of these.     

A Preliminary Examination of Differential Decomposition Patterns in Mass Graves

Five pairs of mass graves, each containing carcasses of 21 rabbits, were used to examine differential decomposition at four locations within the burial: surface, deep, mid‐outer, and core. Every 100 accumulated degree days (ADD), a pair of graves was exhumed, and total body score (TBS) and internal carcass temperature of each rabbit were recorded. Decomposition did not differ for core‐ and deep‐positioned carcasses (p = 0.13); differences were significant (p < 0.001) for all other location comparisons. Decomposition occurred fastest in shallow carcasses, followed by mid‐outer carcasses; deep and core carcasses decomposed slowest and at rates not significantly different from one another. Adipocere formation was minimal and confined to deep carcasses. Carcass location within the mass grave significantly influenced internal carcass temperature (p < 0.001); a mean internal temperature difference of ca. 1°C existed between deep and shallow carcasses (30 cm apart). Effects of mass compactness and oxygenation require further investigation.     

基层公务员创新何以提升“放管服”改革成效?——基于组织学视角的逻辑解释

"放管服"改革是全面深化改革的重要内容,而基层公务员是打通"放管服"改革落地"最后一公里"的关键。探索如何将基层公务员创新行为转化为卓越的"放管服"改革成效具有重要现实意义。本研究基于行为公共管理视角,探索基层公务员创新行为对"放管服"改革成效的积极效果,通过对158家单位、793个有效配对样本的跨层次分析,结果表明,基层公务员创新行为对"放管服"改革任务绩效、政务服务满意度有显著的促进作用。其中,改革目标清晰度、服务群众导向会促进基层公务员创新行为对"放管服"改革任务绩效、政务服务满意度的积极影响。