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.

Network Analysis of Y-STR in Six Ethnic Populations in Guangxi and Its Forensic Significances / 法医学杂志

Objective To explore the distribution of genetic structure of Y-SNP and Y-STR genetic markers in different ethnic groups and its application in forensic science. Methods SNaPshot minisequencing was used to detect the polymorphisms of 12 Y-SNP loci in 439 males from 6 ethnic groups, including Guangxi Han, Guangxi Jing, Guangxi Miao, Guangxi Yao, Guangxi Zhuang and Guangxi Dong. DNATyperTM Y26 kit was used to multiplex-amplify 26 Y-STR loci. The PCR products were analyzed by 3130xl genetic analyzer. The network analysis of Y-STR haplotype under the same Y-SNP haplogroup was analyzed by Network 5.0 software. Results Six haplogroups defined by 12 Y-SNP loci were detected in 6 ethnic groups, and 362 haplotypes were detected in 26 Y-STR loci. The haplotype diversity was 0.996 6. In the C haplogroup, the samples from Guangxi Yao, Guangxi Zhuang and Guangxi Dong were clustered on different branches; in the O1 haplogroup, those from Guangxi Zhuang, Guangxi Miao and Guangxi Jing were relatively independent and clustered separately; in the O2 haplogroup, some samples from Guangxi Miao and Guangxi Yao were gathered in a cluster. Conclusion Based on the Y-STR network analysis of samples with identical haplogroup of Y-SNP, some ethnic groups can be preliminarily distinguished, which could be used to infer male suspects' ethnic group through detecting their genetic markers left in the crime scene.

Genotyping of ABO Blood Group in Partial Population of Yunnan Province by SNaPshot Technology / 法医学杂志

OBJECTIVES@#To detect the genotype of ABO blood group by SNaPshot technology.@*METHODS@#DNA were extracted from the peripheral blood samples with known blood groups （obtained by serology） of 107 unrelated individuals in Yunnan. Six SNP loci of the 261th, 297th, 681th, 703th, 802th, and 803th nucleotide positions were detected by SNaPshot Multiplex kit, and relevant genetics parameters were calculated.@*RESULTS@#In 107 blood samples, the allele frequencies of types A, B, OA, and OG were 0.355 1, 0.168 2, 0.230 0 and 0.247 6, respectively, while that of types AG and cis AB were not detected. The genotyping results of ABO blood group were consistent with that of serologic testing.@*CONCLUSIONS@#SNaPshot technology can be adapted for genotyping of ABO blood group.

DNA polymorphism detection of Papaver somniferum L using fluorescent amplified fragment length polymorphism / 法医学杂志

OBJECTIVE@#To detect DNA polymorphism of Papaver somniferum L using fluorescent Amplified Fragment Length Polymorphism.@*METHODS@#Genomic DNA was isolated using the AxyPrep DNA Kit, double-digested by two restrictional endonucleases (Eco RI and Mse I) and ligated to oligonucleotide adapters. After Pre-amplification and selective amplification, the DNA fragments were separated by capillary electrophoresis using the CEQ8000 DNA Fragment Analyzer.@*RESULTS@#More than 20 fragments of highly polymorphic products were obtained by 8 pairs of primer from 64 selective amplifying primer pairs.@*CONCLUSION@#The fluorescent AFLP technique can be used to detect the DNA polymorphism of Papaver somniferum.

Gene frequencies of 4 STR loci in Tibetan population of Yunnan province / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the gene frequencies of 4 STR loci in Tibetan population of Yunnan.</p><p><b>METHODS</b>Multiple polymerase chain reaction (PCR), denaturing polyacrylamide gel electrophoresis and silver staining were used to detect D21S11, D8S1179, D16S539 and LPL loci. DNA samples collected from 105 unrelated Tibetan individuals in Yunnan province were analyzed.</p><p><b>RESULTS</b>At D21S11, D8S1179, D16S539 and LPL loci, 13, 8, 7, 6 alleles and 33, 21, 16 and 9 genotypes were observed, respectively. The genotype distribution of the 4 STR was in accordance with the Hardy-Weinberg equilibrium.</p><p><b>CONCLUSION</b>The high combined discrimination power and exclusion power of the four loci in Tibetan population make multi-PCR detection a valuable tool for forensic identity, genetics and anthropology.</p>