Individual Identification in Facial Appearance Biometrics Based on Macroscopical Comparison / 法医学杂志

Individual identification is one of the research hotspots in the practice of forensic science, and the judgment is usually built on the comparison of the unique biological characteristics of the individual, such as fingerprints, iris and DNA. With the dramatic increase in the number of cases related to video image investigations, there is an increasing need for the technology to identify individuals based on the macroscopic comparison of facial appearance biometrics. At present, with the introduction of computer three-dimensional (3D) modeling and 3D superimposition comparison technology, considerable progress has been made in individual identification methods based on macroscopic comparison of facial appearance biometrics. This paper reviews individual facial appearance biometric methods based on macroscopical comparison, comprehensively analyzes the advantages and limitations of different methods, and puts forward recommendations and prospects for subsequent research.

Time Regularity of Morphology of Blood Pools / 法医学杂志

Objective To provide reference indexes and theoretical basis for age estimation of blood pools by investigating the entire drying process and monitoring the change of morphology and mass. Methods Four 15 mL blood pool samples were prepared on the clean ceramic plate. The change of morphology and mass of blood pools in a closed dark environment with a temperature of （20.0±0.5） ℃ and a humidity of 35%-45% were dynamically observed from 0 h to 60 h. Images of the blood pools were recorded by digital camera. The area of blood pools was calculated by MATLAB R2014b, the length of cracks was measured by Image J and the statistical analysis was performed by SPSS 16.0. Results By summarizing and analyzing, the drying of blood pools was divided into five stages： coagulation （0-4.5 h）, gelation （>4.5-20.0 h）, gel-solid mixing （>20.0-37.0 h）, solid （>37.0-40.0 h） and final desiccation （>40.0-45.0 h）. From 0 to 45 h, the mass of the blood pools decreased linearly with time, and the decrease was not obvious from 45.0 to 60.0 h. The standardized mass （y2） showed strong correlation with the time （x） y2=0.018 2 x+0.271 4（R2=0.967 9）. The area change rate of blood pools, the distance that the edge of blood pools moved, the average length of radical cracks had little correlation with the time that passed. Conclusion The overall morphological characteristics of blood pools show a certain regularity with the time and the standardized indexes established provide a reference for the age estimation of blood pools.

Development of Integrated Device of Trace Bloodstains Imaging and Age Analysis / 法医学杂志

Objective To develop a device of trace bloodstains imaging and age analysis, so as to provide a non-destructive, simple and objective method for age estimation of bloodstains at the crime scene. Methods Based on the principle of digital imaging and color pattern analysis, the mobile terminal of the device was used to collect images of bloodstains of different ages. The time-dependent pattern of 6 parameters （R, G, B, C, Y, M） reflecting the changes of color of images of different ages was obtained by computer image analysis. A multiparameter comprehensive inference equation of bloodstains age was established and embedded into the device software to realize the intelligent inference of the bloodstains age. Then the capability and reliability of the device was verified. Results This integrated device of bloodstains imaging and age analysis could quickly collect bloodstains at the crime scene and automatically analyze and infer the age of bloodstains combined with related intelligence software. In the blind test, the detection accuracy of this device was 95% in both natural light airtight group and dark airtight group, and 80% in the natural light ventilation group. Conclusion The integrated device of trace bloodstains imaging and age analysis can be used in a simple manner, which provides a new objective method for bloodstains age estimation.

Research Progress on Diagnosis of Drowning / 法医学杂志

These external and internal signs of drowning are non-specific. Therefore, diagnosis of drowning is always one of the most difficult tasks in forensic pathology. This paper meticulously and comprehensively reviews research progress on the diagnosis of drowning in pathological signs, laboratory examination, immunohistochemistry test and virtopsy technology, and it also prospects the research direction of diagnosis of drowning.

Relationship between corneal thickness and postmortem interval in rabbit / 法医学杂志

OBJECTIVE@#To explore the relationship between corneal thickness and postmortem interval (PMI) in rabbit.@*METHODS@#The rabbit model was established by air embolism. The rabbit cornea was sampled at 6-hour-interval from 0 to 72 h postmortem. After routine HE staining, the whole cornea image was collected by the optical microscope. Three markers were observed including corneal epithelial thickness (x1), corneal stromal thickness (x2) and whole corneal thickness (x3) using Motic Images Plus 2.0 image analysis software and the data were statistically analyzed to establish the regression function with PMI (y).@*RESULTS@#Within 72 h postmortem, rabbit corneal stromal thickness and whole corneal thickness increased at 12h postmortem and reached the peak at 54h postmortem. The two markers showed positive correlation with PMI. The regression functions of the two markers were y = -0.070 2 x2(2) +11.398 x2 + 1634 (R2 = 0.712 2, P < 0.05) and y = -0.074 9 x3(2) +12.036 x3 + 1819.4 (R = 0.675 0, P < 0.05), respectively.@*CONCLUSION@#The two markers of corneal stromal thickness and the whole corneal thickness showed the strong linear correlation with PMI. The correlation of the corneal stromal thickness is better than the whole corneal thickness. The two markers can be used to estimate PMI.

Time-dependent recruitment and differentiation of fibrocytes in mouse skin wound healing / 法医学杂志

OBJECTIVE@#To investigate the time-dependent recruitment and differentiation of fibrocytes in skin wound healing.@*METHODS@#Fibrocytes (expressing CD45 and procollagen I ) and myofibroblasts (expressing CD45 and alpha-SMA) were co-localized by immunofluorescent staining. The number of fibrocytes and myofibroblasts was counted at different post-wounding interval.@*RESULTS@#At 3 d after injury, fibrocytes started to recruit at the margin of the wounds. At 5 d after injury, myofibroblasts started to appear in new formed granulation tissue. The number of fibrocytes and myofibroblasts peaked at 7 d post-wounding.@*CONCLUSION@#During skin wound healing, myofibroblasts in granulation tissue originated at least partly from fibrocytic differentiation. The time-dependent recruitment and differentiation of fibrocytes may provide new information for wound age determination.

Expression of cannabinoid receptor I during mice skin incised wound healing course / 法医学杂志

OBJECTIVE@#To investigate the expression of cannabinoid receptor I (CB1R) during mice skin incised wound healing course and time-dependent changes of CB1R in wound age determination.@*METHODS@#The changes of CBIR expression in skin incised wound were detected by immunohistochemistry and Western blotting.@*RESULTS@#The control group showed a low expression of CB1R detected mainly in epidermis, hair follicles, sebaceous gland and dermomuscular layer. CB1R expression was undetectable in neutrophils in the wound specimens from 6h to 12h post-injury. CB1R positive cells were mostly mononuclear cells (MNCs) and fibroblastic cells (FBCs) from 1 d to 5 d post-injury. CB1R positive cells were mostly FBCs from 7 d to 14d post-injury. The ratio of the CB1R positive cells increased gradually in the wound specimens from 6 h to 3 d post-injury, reached peak level at 5 d, and then decreased gradually from 7d to 14 d post-injury. The positive bands of CB1R were observed in all time points of the wound healing course by Western blotting. The expression peak showed at 5 d post-injury.@*CONCLUSION@#CB1R is activated during the wound healing course. The expression of CB1R is found in mononuclear cells, which could be involved in inflammation reaction. CBIR is observed in fibroblastic cells, which could participate in the wound healing. CB1R may be a potentially useful marker for determination of wound healing age.

DNA degradation in nucleolus of skeletal muscle, heart, liver, kidney and brain in mice after death / 法医学杂志

OBJECTIVE@#To study the change of DNA degradation in nucleolus of mice organs and its relationship with the postmortem interval, and to investigate a new accurate method to estimate the postmortem interval.@*METHODS@#Eight parameters of cell nuclei were chosen, including the head DNA level, the tail DNA level, the head radius, the tail length, the tail moment, the Olive moment, the head area and the tail area. The changes of DNA degradation were analyzed in skeletal muscle, myocardium, liver, kidney and brain in mice at different intervals (0-72 h postmortem) by using single-cell gel electrophoresis and fluorescent microscope connected with auto-analysis-image system.@*RESULTS@#The tail DNA level, the tail length, the tail moment, the Olive moment and the tail area showed an increasing tendency. The head DNA level, the head radius and the head area showed a decreasing tendency within 72h postmortem in mice. A quadratic regression equation (P < 0.001) and multiple regression equation of DNA degradation tendency were established (P < 0.000 1).@*CONCLUSION@#The regression equations established can be used as a new method for estimating postmortem interval in forensic practice.

The time-dependent changes of phospho-JNK expression during the skin incised wound healing in mice / 法医学杂志

OBJECTIVE@#To investigate the changes of phospho-JNK (p-JNK) during the incised wound healing of the skin in mice and to explore the rule of the time-dependent change of p-JNK in wound age determination.@*METHODS@#The changes of p-JNK expression in incised skin wound were detected by immunohistochemistry and Western blot.@*RESULTS@#There was a minimal baseline staining of p-JNK in control mouse skin. Changes of p-JNK expression were mainly detectable in neutrophils in the wound specimens from 3 hours to 12 hours after injury. Afterwards, the p-JNK positive cells were mostly mononuclear cells and fibroblasts between post-injury day 1 and day 5, whereas the p-JNK positive cells were mostly fibroblasts between post-injury day 7 and day 14. Morphometrically, the ratio of the p-JNK positive cells to the total increased gradually in the wound specimens from 3 hours to day 1, and maximized at day 1 with a slight decrease from post-injury day 3 to day 5. The ratio showed a second peak in the specimens of day 7, and then decreased gradually from post-injury day 10 to day 14. The changes of p-JNK expression were observed throughout the wound healing stages by Western blot as well, with a peak expression occurring between 12 hour and day 3 after injury.@*CONCLUSION@#p-JNK may play a pivotal role in inducing apoptosis of neutrophils, mononuclear cells, and fibroblasts during skin wound healing and meanwhile, p-JNK may be a potentially useful marker for wound age determination.

Posttraumatic stress disorder (psychiatric injury) after road traffic accidents in forensic medicine: a primary study / 法医学杂志

OBJECTIVE@#Studying forensic medical problem related with RTA leading PTSD and supplying accumulating evidence for psychiatric compensation in court.@*METHODS@#One hundred and fifty six victims of RTA were recruited who applied to court for a costs order. The victims were examined for psychiatric diagnosis by psychiatrists and for rank of impairment by experts in forensic clinical medicine. The self-report psychopathological status and quality of life were also measured.@*RESULTS@#Eighty one victims of 156 (51.92%) fulfilled the criteria for PTSD (ICD-10). Morbidity difference in male and female were significant; The more serious extent of impairment is, the more PTSD'possibility is; The scores in World Health Organization Quality of Life were lower and in SAS and SDS were higher in PTSD group than in non-PTSD group. Acquirement of awarded costs could obviously prevent PTSD.@*CONCLUSION@#The higher PTSD incidence existed in the RTA victims who applied to court for a costs order, and acquirement of awarded costs could obviously prevent PTSD.