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The rising crime rate associated with document forgery has a significant impact on public safety and social stability. In document fraud cases, determining the origin of a particular stamp-pad ink is the most important objective. In this study, a comprehensive analysis of the volatile compounds in quick-drying stamp-pad inks from six commonly used brands were performed for the first time, utilizing a combination of headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and multivariate statistical analysis methods. Visual and comparative analysis of the differential volatile components among different stamp-pad ink samples was conducted using fingerprints and volcano plots. A total of 127 volatile compounds were accurately identified, with ketones, esters, alcohols, and aldehydes being the most abundant compounds in the stamp-pad inks. Hierarchical clustering analysis (HCA), including dendrograms and clustering heatmaps, was utilized to explore the correlations between these compounds and the samples. Additionally, the precise identification of positional isomers and functional group isomers of aliphatic compounds was achieved. To achieve accurate discrimination of various stamp-pad ink samples, a multivariate statistical analysis method was utilized to establish a classification model for them. Based on the results obtained from HS-GC-IMS, effective discrimination among different brands of stamp-pad ink samples was achieved through principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). The model exhibited excellent performance, with the fit index of dependent variables (R2Y) and the predictive index of the model (Q2) values of 0.99 and 0.984, respectively. These results provided significant theoretical evidence for the application of HS-GC-IMS as an efficient technique in the analysis of volatile compounds, identification of positional isomers and functional group isomers, as well as tracing the origin of stamp-pad ink and analyzing the formation time of documents. [ABSTRACT FROM AUTHOR]

Three sites with different surface roughness were selected to explore the turbulent/synoptic separation and self-similar wall-attached coherent structures in the atmospheric surface layer. At each site, the facility permits synchronous multi-point measurements of three-dimensional wind velocity and temperature at different heights, as well as synchronous measurements via the global positioning system among the three sites. A filter based on the linear coherent spectrum between two sites (separated by 500 m) is adopted to separate turbulent and synoptic signals. After the separation, the two-point correlations of the filtered turbulent streamwise velocity component reveal that increasing surface roughness leads to less coherence in both the wall-normal and streamwise directions. The present results with unstable stratification and different surface roughness also demonstrate good agreement with the self-similar range of the wall-attached turbulence reported in Baars et al. (J Fluid Mech 823:R2, 2017). The aspect ratio of coherent structures (defined as the ratio of streamwise wavelength to the wall-normal offset) for the streamwise and spanwise velocity components and temperature increases with increasing surface roughness. [ABSTRACT FROM AUTHOR]

Electrical injury is a relatively uncommon but potentially devastating form of multi-system injury with high morbidity and mortality. In common electric injury cases, it is usually difficult to find characteristic changes of electric injury in major organs by using routine histopathological test methods unless there are landmark traces of electric injury, known as electric marks. How to determine electric shock death, especially in the absence of typical electrical marks on the body surface in some cases (which account for about two-thirds of electric injury cases), remains a challenging problem in forensic practice. Our summary shows that many current related studies have focused their efforts to find characteristic histopathological changes in major organs of the body caused by electric injury. Based on the results obtained through comparison of the literature, we find that it may be more urgent and important to find the optimal autopsy or sampling sites in cases with no typical electric marks, knowing that these sites may often reflect the most significant histopathological changes of electric injury, for instance anatomy and sampling of the anterior wrist and the medial malleolus in cases involving the hand-to-foot electric circuit pathway. In this article, we make a summary of advances in identification methods of electric injury, hoping that it could provide some new insights for further research in this field. [ABSTRACT FROM AUTHOR]

Gastromalacia, a postmortem dissolution of the stomach, is caused by endogenous enzymes resulting in thinning and softening of the stomach wall with focal perforation. Thus, identifying gastromalacia and differentiating it from other causes of gastric perforation is essential to avoid misdiagnosis. Herein, three cases of gastromalacia are described. The victims died due to hyperthermia, leukemia complicated by cerebral hemorrhage, and asphyxia due to inhaled vomitus, respectively. The macroscopic and microscopic appearance in three cases indicated gastromalacia, although multiple factors confused the diagnosis. Furthermore, the differential diagnosis and the underlying mechanism are discussed. [ABSTRACT FROM AUTHOR]

The genetic polymorphisms of 21 autosomal short tandem repeat (STR) loci included in the GlobalFiler™ PCR Amplification Kit were evaluated in 3032 unrelated individuals Altay Han of Xinjiang, northwest China. All of the loci reached the Hardy-Weinberg equilibrium. These loci were examined to determine allele frequencies and forensic statistical parameters. SE33 showed the greatest power of discrimination in Altay Han population, whereas TPOX showed the lowest. The combined discrimination power and probability of excluding paternity of the 21 autosomal STR loci were 0.999999999999999999999999889838 and 0.999999996664704, respectively. Both pairwise genetic distance and phylogenetic methods indicated that the Altay Han had the closest genetic relationship with the Han origin and Hui populations. The present results revealed that the GlobalFiler system had a high level of polymorphism in Altay Han population and hence could be a powerful tool for forensic application and population genetic study. [ABSTRACT FROM AUTHOR]