Objective To analyze the characteristic of trauma in 246 fatal falls. Methods We collect 246 cases of fatal falls from Pudong district of Shanghai from 2005 to 2014, and then analyze the characteristics of trauma by using different parameters. Results The height in suicides by fall is higher than accidents by fall (25.7m:13.98m). In all fatal falls, head has a higher possibility in suffering trauma than other body regions (75.2%), while neck has a lower possibility (6.5%). The possibility of head trauma in accidents by fall is higher than suicides by fall (89.4%:75.2%). Conclusion Comparing with suicides by fall, victims in accidents by fall have lack of protection from limbs. Besides, the low rate of ifnding neck trauma suggests legal physicians should be more careful in examining this area.

MicroRNA has speciifc biological and expression properties in transcription level, which has more potential than genomic DNA in the identification for forensic body fluid, species and degraded crime biological materials. Here we introduce the speciifc research of forensic body lfuid identiifcation, research strategies and applied perspectives with forensic miRNA, expecting to provide the application and study of miRNA analysis for reference.

Objective To construct a rapid genetic DNA extraction method, with nano magnetic beads, self-designed reagents system and extracting process. Method Part I: DNA extraction from old blood cotton swab sample with self-designed DNA extraction kit, then quantiifed by UV spectrophotometer. The method was further optimized on the preliminary results. Part II: All kinds of difficult DNA sample were tested with optimized kit, to detect the applicability of the kit. Result By improving the experimental condition, the extraction effects of different DNA sample is good, meanwhile, the extraction cost is relatively low.

In recent years, the cases of prenatal paternity testing gradually increased in forensic practice. The traditional prenatal paternity analysis can be performed only after invasive sampling of chorionic villi or amniotic fluid, which can result in a risk of miscarriage. The existence of circulating cell-free fetal nucleic acid in maternal plasma has brought new opportunities for the noninvasive prenatal paternity testing. In this paper, the research situation and application prospect of circulating cell-free fetal nucleic acid in maternal plasma in prenatal paternity testing are reviewed.

Objective To establish a digital system for forensic identiifcation of the palatal rugae and evaluate its application effects. Methods High-resolution digital images of the palatal rugae were harvested under the standard condition and processed including data collection, noise reduction, contrast enhancement, image segmentation, feature extraction, edge detection, and information matching. Apply an MATLAB software system to develop a digital system for forensic identiifcation of the palatal rugae ,and its application effects were evaluated. Results A digital system for forensic identification of the palatal rugae was successfully established. The digital system had an accuracy rate of 100%. Conclusion Establishing a digital system for forensic identiifcation of the palatal rugae provides a novel method for forensic identiifcation.

Objective To investigate the alteration of energy metabolism and oxidative injury in the myocardia suffering from lethal ventricular tachyarrhythmia (LVTA). Methods Two LVTA-SCD SD rat models, induced by aconitine injection or coronary artery ligation (CAL), respectively, were developed. Rats that died from over-anaesthesia or CAL-induced heart failure were served as their controls, respectively. Mitochondrial membrane potential (MMP), reactive oxygen species (ROS), malonaldehyde (MDA), phosphocreatine (PCr) in the ventricular myocardia, and serum troponin I (cTnI) were detected, and compared between LVTA rats and their controls. Results Fourteen ACO-LVTA and six CAL-LVTA rats were successfully developed. As compared to their controls, ACO-LVTA and CAL-LVTA rats had higher ROS and MDA content, and lower concentration of PCr in the ventricular myocardia. MDA content in ACO-LVTA group is signiifcantly higher than that of its control (P<0.05). MMP in myocardia of ACO-LVTA is lower than that of its control, but is higher than those of two CAL groups. Serum cTnI in rats of both LVTA models is higher than those of their controls and pre-treated control. Specially, serum cTnI in CAL-LVTA was signiifcantly higher than that of ACO-LVTA and its control (P<0.01). The myocardial ROS content is correlated with the duration of VT and VF (P<0.05), with correlation coefifcients being 0.44 and 0.46, respectively. Conclusions After LVTA, the ventricular myocardia had lower MMP and PCr content, higher concentration of ROS, MDA, as well as higher serum cTnI than their controls, indicative of oxidative injury and alteration of energy metabolism under LVTA-SCD.

Objective To detect the molecular characteristics of the serum samples of rats suffered from sudden unexpected death of acute myocardial ischemia (experimental group) and death caused by air embolism (control group) applied by ATR-FTIR, and to discuss the forensic signiifcance of identiifcation of causes of death by sudden unexpected death of acute myocardial ischemia by two-dimension infrared spectroscopy. Methods Adult male SD rats were randomly divided into SCD group and DCAE group. The serum samples were analyzed by ATR-FTIR. The similarity coefifcient of spectra between two groups was analyzed by OMNIC software. The spectra with higher signal-noise ratio were obtained and used to build two-dimension spectra model by Matlab 2010a software. Results The peak shapes, positions and intensities of the spectra were extremely similar between two groups, and the similarity coefifcient reached 99.78%. Meanwhile, the similarity coefifcient of second derivative spectra decreased to 98.62% between two groups. Moreover, on the two-dimension spectra model, the component differences were present at about 1 625cm-1, 1 550cm-1, 1 080cm-1 and 860cm-1, and the number of auto-peaks was different, which suggested that the evident differences were related to the molecular contents of protein, glycogen, nuclear acid, and so on. Conclusion It is hard to differentiate the molecular differences of serum samples of rats between SCD and DACE based on one-dimension spectra. However, two-dimension infrared spectra could intuitively and effectively relfect the molecular differences, and it would apply to determining the cause of death in forensic science.

Objective To investigate the relationship between the root diameter and the diameter of the root canal and the diameter of the root canal of the maxillary central incisors of Han nationality.Methods November 2014 to 2015 during November,select the database in a local three grade hospital in 420 cases of Han nationality in CBCT image data as the research object,according to the age will be all of the subjects were divided into six (8～12 years old,13 to 17,18 22,23 to 27,28 to 32,33 to 37 years old),70 cases in each group,men and women,15 cases in each group.Of all the research object of the maxillary central incisor root diameter and root pipe diameter were measured,take the cemento enamel junction from the apical 3/4,analysis of maxillary central incisor root diameter and root tube diameter and age,men and women of the maxillary central incisor root diameter.Results The men and women of the maxillary central incisor root diameter compared with significant difference (P＜0.05);male and female maxillary central incisor root diameter compared with significant difference (P＜0.05);male and female maxillary incisor root diameter and root diameter ratio compared with the difference significant (P＜0.05);different genders maxillary central incisor root diameter and root diameter ratio and age has certain correlation (R2=0.623,P＜0.05).Conclusion The root diameter and the diameter of root canal of maxillary central incisors of Han nationality were correlated with the age,and the trend of male root canal diameter was higher than that of female.

Objective To explore the effectiveness of whole genome amplification technology in DNA typing of trace samples.Methods Simulated trace samples which contain 1～20 cells were prepared by micromanipulation.Whole genome amplification was added before conventional PCR-STR typing step,to compare the effectiveness of PEP and MDA in DNA typing of trace samples from four aspects i.e.allele imbalance,allele drop-out,locus drop-out and pseudo allele (which contains the stutter peak).Results Amplification efficiency of MDA was higher than PEP method,but allele drop-out and pseudo allele were more frequently detected.Correct DNA typing rate of PEP is higher than MDA method,however,advantaged amplification of small fiagments DNA is more obvious.Conclusion MDA method is not suitable for the current STR typing.When the absolute amount of trace samples is quite small,we couldconsider using the PEP method to enhancethe sample quantity to meet the requirement of repeat testing.At the same time it could encounterthe failure of the large DNA fragments.

Next generation sequencing (NGS),also known as massively parallel sequencing (MPS),with significant advantages such as high throughput,rapidness,integration and low cost,has been widely used in research and clinical diagnosis fields and promises bright future for forensic applications.Compared with traditional DNA sequencing methods,NGS technologies allow the simultaneous detection of various forensic genetic markers.The classical CE-based STR genotyping method only can differentiate alleles with length polymorphism.However,there are occasions like DNA base substitution and repeat sequence variations,which give different alleles with the same size of amplicons.These alleles are heritable from parents to off-springs,and could be of great importance for solving criminal cases.NGS-based STR genotyping can be compatible with current STR data output mode,and allows for the full resolution of STR loci by providing additional sequencing polymorphism information.In this article,the authors focused on the forensic STR genetic markers and next generation sequencing,and reviewed recent progresses on NGS-based STR genotyping.Perspectives of NGS-based full resolution STR genotyping were presented and possible challenges were discussed in the hope of providing a reference for related studies and applications.