Retrospective Analysis of 73 Hanging and Ligature Strangulation Cases / 法医学杂志

Objective To retrospectively analyze 40 cases of hanging and 33 cases of ligature strangulation in Kunming, to explore the neck injury characteristics and similarities and differences of related asphyxia signs of corpses in hanging and ligature strangulation cases, in order to provide reference for forensic identification. Methods Statistics of hanging and ligature strangulation cases accepted by Kunming Municipal Public Security Bureau from 2000 to 2017 were collected. Data including the gender, age, injury tool, neck injury and related asphyxia signs of the deceased in hanging and ligature strangulation cases were statistically tested by SPSS 23.0. Results There were more males in hanging cases than females. However, there were more females than males in ligature strangulation cases. In hanging cases, suicide was common, while homicide was rare. In ligature strangulation cases, homicide was common, while suicide or accidental death was rare. The average age of the deceased in hanging cases were older than those in ligature strangulation cases. The ligature mark in hanging was usually above the thyroid cartilage. The ligature mark in ligature strangulation was usually at the same level of the thyroid cartilage. The most common vital reactions were exfoliation and subcutaneous hemorrhage at the ligature mark, common among the deceased in hanging cases. Hyoid fracture rate of the deceased in ligature strangulation cases was more common than those in hanging cases. Conclusion The gender, age distribution, position of ligature mark, detection rate of vital reactions at the ligature mark and hyoid fracture rate of the deceased can help distinguish hanging from ligature strangulation.

Application of 18S rDNA Clone Library to Detect Diatom Population Diversity in Dianchi / 法医学杂志

Objective To detect the diatom population diversity in Dianchi by constructing a 18S rDNA clone library. Methods DNA from diatoms in 6 water samples of Dianchi was amplified with diatom 18S rDNA specific primer.The 18S rDNA clone library was constructed, and clones were randomly selected for sequence. Sequence alignment was performed by BLAST. The diatom population distribution in Dianchi was analyzed and the phylogenetic tree of diatom 18S rDNA in Dianchi waters was established with the MEGA v7.0.14 software. Results Two hundred and forty clones were sequenced, with 167 diatom sequences obtained, including 11 diatom species such as Stephanodiscus, Diatoma, and Melosira. There were certain differences in diatom population distribution among the 6 samples. Conclusion The population distribution of diatom species in Dianchi shows unique features and the sequence analysis of diatom 18S rDNA has a certain reference value to the inference of forensic drowning sites.