Application of Demirjian's and Cameriere's Method in Dental Age Estimation of 8-16 Year Old Adolescents from Hunan Han Nationality / 法医学杂志

Objective To apply Demirjian's and Cameriere's method for dental age estimation of adolescents from Hunan Han nationality, and compare the accuracy of the two methods. Methods A total of 480 orthopantomograms of?8-16 year?old adolescents from Hunan Han nationality?with no special diseases and good nutritional status were collected?by Xiangya Stomatological Hospital of Central South University from January, 2016 to July, 2017, among them 236 males and 244 females. The dental age of each adolescent was determined by Demirjian's method and Cameriere's method, respectively, and the paired t-test of the estimated dental age and the chronological age determined by the two methods was conducted by SPSS 20.0 software to compare the difference between estimated dental age and chronological age. Results Mean chronological age of males and females was 11.91 and 11.88 years, respectively. The estimated dental age determined by Demirjian's method showed an underestimate of chronological age by an average of 0.11 years （males） and 0.15 years （females）, while the estimated dental age determined by Cameriere's method showed an underestimate of chronological age by an average of 0.83 years （males） and 0.72 years （females）. Conclusion Demirjian's method is more accurate than Cameriere's method in dental age estimation of adolescents from Hunan Han nationality, therefore more suitable for dental age estimation of adolescents in this region.

Research Progress of Vitreous Humor Detection Technique on Estimation of Post-mortem Interval / 法医学杂志

Estimation of postmortem interval(PMI)plays a crucial role in forensic study and identifica-tion work. Because of the unique anatomy location, vitreous humor is considered to be used for estima-ting PMI, which has aroused interest among scholars, and some researches have been carried out. The detection techniques of vitreous humor are constantly developed and improved which have been gradually applied in forensic science, meanwhile, the study of PMI estimation using vitreous humor is updated rapidly. This paper reviews various techniques and instruments applied to vitreous humor detection, such as ion selective electrode, capillary ion analysis, spectroscopy, chromatography, nano-sensing technology, automatic biochemical analyser, flow cytometer, etc., as well as the related research progress on PMI es-timation in recent years. In order to provide a research direction for scholars and promote a more accu-rate and efficient application in PMI estimation by vitreous humor analysis, some inner problems are also analysed in this paper.

Genetic Polymorphisms of 21 STR Loci in Hunan Province-based Han Population / 法医学杂志

OBJECTIVES@#To investigate the genetic polymorphisms of 21 short tandem repeat （STR） loci （D3S1358, D13S317, D7S820, D16S539, Penta E, D2S441, TPOX, TH01, D2S1338, CSF1PO, Penta D, D10S1248, D19S433, vWA, D21S11, D18S51, D6S1043, D8S1179, D5S818, D12S391 and FGA）.@*METHODS@#A total of 560 blood samples were collected from unrelated healthy individuals of Han population in Hunan Province. Chelex-100 extraction method was applied to the extraction of genomic DNA, and an AGCU EX22 Kit and 9700 STR amplification was used in amplification reactions. The products were separated and analyzed on 310 Genetic Analyzer.@*RESULTS@#A total of 248 alleles were observed, the allelic frequencies ranging from 0.001 to 0.518. Observation of genotype distributions for each locus showed no deviations from Hardy-Weinberg equilibrium except Penta E （P=0.023）. The combined power of discrimination, combined power of exclusion, and combined matching probability of the 21 STR loci were approximately 0.999 999 999 999 999 999 999 999 8, 0.999 999 998, and 1.36×10⁻²⁵, respectively.@*CONCLUSIONS@#The 21 STR loci show high polymorphisms in the Han population, which can provide valuable data and a theoretical basis for forensic individual identification and paternity testing.

Identification of sarcosaphagous Calliphorid flies by analyzing the sequence of 16S rDNA / 法医学杂志

OBJECTIVE@#To explore the application of a 289bp fragment of the 16S rDNA gene to identify various species of sarcosaphagous Calliphorid flies.@*METHODS@#Twenty-six Calliphorid flies were collected from 14 Chinese provinces. All specimens were properly assigned into three genera and six species. The DNA of the pectoralis was extracted using CTAB method. Then PCR amplification was done for the 289 bp fragment of the 16S rDNA gene. The PCR products were then purified and sequenced, and the obtained sequences were uploaded to GenBank. The phylogenetic tree was built by the neighbor-joining method and intraspecific and interspecific divergences were calculated by sequence analysis.@*RESULTS@#The above 26 sarcosaphagous flies could be well clustered according to different genera and species. The evolutional intraspecific values were all zero, the evolutional interspecific variations varied from 0.3% to 6.5%.@*CONCLUSION@#The 289 bp fragment of the 16S rDNA of sarcosaphagous flies can be effectively used to identify most of the flies at species level. This method appears to be fast and low dissipative, which might be used to estimate postmortem interval by sarcosaphagous flies.

Comparison of mtDNA extraction from different parts of sarcosaphagous insects / 法医学杂志

OBJECTIVE@#To explore mitochondrial DNA (mtDNA) extraction effects of different parts from sarcosaphagous insects using improved cetyltriethylammnonium bromide (CTAB) method.@*METHODS@#Thirteen Lucilia sericata (Meigen) and 13 Nicrophorus fossor (Erichson) were collected from the corpses of rabbits placed on the outdoor lawn in Huhehot district. Four parts (head, chest muscle, legs and wings) of insect were collected, and the mtDNA of all samples were extracted using CTAB method. The purity and concentration were tested using protein and nucleic acid spectrophotometry. The integrity of the extracted mtDNA and PCR products were checked by agarose gel electrophoresis. The PCR products were sequenced and the obtained sequences were imputed into GenBank for comparison.@*RESULTS@#mtDNA were successfully extracted from 10 head samples, 6 legs samples, 4 wing samples and 13 chest muscle samples of the Lucilia sericata (Meigen). Also, mtDNA were successfully extracted from 5 head samples, 8 legs samples, 3 wing samples and 13 chest muscle samples of the Nicrophorus fossor (Erichson).@*CONCLUSION@#mtDNA can be obtained from chest muscle and other parts of sarcosaphagous insects using the improved CTAB method.

Succession of sarcosaphagous insects at summer and autumn in Shijiazhuang area / 法医学杂志

OBJECTIVE@#To study the succession of sarcosaphagous insects and their regular activity on carcass in Shijiazhuang area.@*METHODS@#Nine rabbits were sacrificed and placed at the same site during June to September in 2007-2009. The common species of sarcosaphagous insects were observed.@*RESULTS@#Nine main species could be identified belonging to 3 families and 4 genera from Diptera, including Musca domestica (Linnaeus), Muscina stabulans (Fall én), Hydrotaea (Ophyra) capensis (Wiedemann), Hydrotaea (Ophyra) spinigera (Stein), Lucilia sericata (Meigen), Chrysomya megacephala (Fabricius), Boerttcherisca Peregrina (Robineau-Desvoidy), Parasarcophaga crassipalpi (Macquart) and Helicophagella melanura (Meigen). Eleven main species belonging to 4 families from Coleoptera include Nicrophorus concolor (Kraatz), Silpha carinata(Herbst), Nicrophorus fossor (Eneshas), Ptomascopus morio (Kraatz), Eusilpha bicolor (Fairmaire), Scarabaeus rugosus (Hausmann), Harpalus rufipes (DeGeer), Dolichus halensis (Schaller), Goncephalum pusillum (Fabricius), Cafius seminitens (Horn) and Aleochara pacifica (Casey). Two main species from 2 families were Tetramorium caespitum (Linnaeus) and Vespa velutina(Lepeletier).@*CONCLUSION@#It is evident that the succession of sarcosaphagous flies in Shijiazhuang with its unique geographical features. It may be used for estimating postmortem interval in Shijiazhuang area.

Extract human DNA from maggot crop contents by phenol-chloroform method coupled with paramagnetic particle method / 法医学杂志

OBJECTIVE@#To establish an effective phenol-chloroform method coupled with paramagnetic particle method for human DNA extraction from maggot crop contents in STR genotyping.@*METHODS@#Human DNA was extracted from the maggot crop contents using phenol-chloroform method and purified by paramagnetic particle method. DNA was quantified by PCR with Quantifiler Human DNA Quantification Kit using 7500 real-time fluorescence quantitative PCR instrument. PCR products were genotyped by AmpFlSTR Identifiler PCR Amplification Kit using 3130XL-Avant genetic analyzer.@*RESULTS@#The template DNA yield by the method described were increased at least 2 times than the phenol-chloroform extraction method alone. All of the full 16 STR profiles could be obtained with the samples extracted by this method when the DNA yield reached (0.218 +/- 0.041) ng/microL.@*CONCLUSION@#Phenol-chloroform method coupled with paramagnetic particle method can effectively increase the sensitivity of STR analysis of human DNA recovered from maggot crop contents and is a valuable tool for forensic entomology.

The development and application of lie detection in forensic science / 法医学杂志

Lie detection technology has been applied increasingly to investigate and solve criminal cases. This article explores the evolvement of lie detection technology in the ancient times and the application of the psychological and physiological parameters which have become more accurate with the introduction of modern polygraph. The cognitive exploration and the application of Event Related Potentials (ERPs), functional Magnetic Resonance Imaging (fMRI), and Event-Related functional Magnetic Resonance Imaging (E-R fMRI) have made detection technology focus on the brain activities, which produce more objective results by tracing the original state of lying. In summary, this article describes different types of lie detections, simple and complex, their working principles, the latest development, and the prospect of their application in forensic science.

Advances of forensic entomology in China / 法医学杂志

Forensic entomology is a branch of forensic medicine, which applies studies of insects and arthropods to getting evidence for court and has an analogous advantage in the estimation of the postmortem interval (PMI) and other questions of forensic relevance. The paper expounds its definition and contents and reviews some progress of the studies in some aspects in China such as the constitution and succession of insect community on the different cadavers, the applications of morphological features of insects and the technology of analysis of deoxyribonucleic acid (DNA) in forensic entomology, and forensic entomological toxicology etc.

Relationship between CO II gene of mtDNA of Lucilia sericata and latitude interval / 法医学杂志

OBJECTIVE@#To deduce the region that the geographical species of Lucilia sericata come from and determine the scene of crime (SOC) based on the gene analysis of mtDNA CO II.@*METHODS@#A 635 bp region for CO II of 4 Lucilia sericata (belong to 2 geographical species) were collected and sequenced, compared with the data of GenBank. A neighbour-joining tree with the Tamura and Nei model was constructed by MEGA2.1 package. The number of inherit intervals of inner-species were analyzes by Kimura's two-parameter model and used for construction the relationships between hereditary and latitude interval by SPSS10.5 soft.@*RESULTS@#It showed that they had the relationships between inherit and latitude interval for the 8 geographical species of Lucilia sericata for CO II.@*CONCLUSION@#This method can be the evidence deducing the region that the geographical species of Lucilia sericata come from and further to determine the scene of crime (SOC).