The dural thickness, ultimate load, tensile strength, elastic modulus and fracture force decreased sequentially, among which the dural thickness, ultimate load, elastic modulus and fracture force had a correlation with PMI （P0.05）. Conclusion The dural thickness, ultimate load, elastic modulus and fracture force change sequentially from 6 h to 96 h after death. The regression equation established by the relationship between the changes and PMI can be used for PMI estimation.Objective To explore the application value of interleukin-33 （IL-33） in wound age estimation in forensic practice by observing the sequential changes of IL-33 after skin wound. Methods Skin wound models were generated on the back of mice with a round file of 5 mm in diameter.  https://www.selleckchem.com/products/Nolvadex.html  Skin samples of the same size were taken from the same parts of mice in control group and injury group 1 h, 3 h, 6 h, 12 h, 1 d, 3 d, 5 d, 7 d and 10 d after skin wound. Hematoxylin-eosin （HE） staining method was applied to observe the morphological changes in the recovering process after skin wound. Western blotting, immunohistochemistry staining and double immunofluorescence staining methods were applied to detect the expression changes of IL-33 in the skin wound samples. Results The results of Western blotting showed that the expression of IL-33 protein decreased slightly at 3 h after skin wound, increased gradually at 6 h after skin wound, and reached the peak value at 3 d, then decreased gradually. Immunohistochemistry staining results showed that faint positive expression of IL-33 was observed in epidermis, hair follicles, sebaceous glands and dermal resident cells of the control group skin. The positive cell rate of IL-33 increased at 3 h after skin wound and reached the peak value at 3 d, then decreased gradually. The results of double immunofluorescence staining showed that the majority of IL-33 positive cells from 1 d to 3 d after wound were macrophages, while the majority of IL-33 positive cells from 5 d to 7 d after wound were myofibroblasts. In addition, the results of HE staining showed that the wound healing process of the skin wound model was consistent with the pathological development law of inflammation. Conclusion IL-33 could become a reference index for wound age estimation of skin wound in forensic practice.Objective To infer postmortem interval （PMI） based on spectral changes of the dorsal skin of rats within 15 days postmortem using Fourier transform infrared （FTIR） spectroscopy. Methods The rats were sacrificed by cervical dislocation after anesthesia, and then placed at 25 ℃ and relative humidity of 50%. The FTIR spectral data collected from the dorsal skin at PMI points were modeled with machine learning technique. Results There was no significant difference of absorption peak location among all the PMI groups but their peak intensities changed as a function of PMIs. The model for PMI estimation was constructed using partial least squares （PLS） regression, reaching a R2 of 0.92 and a root mean square error （RMSE） of 1.30 d. As shown in variable importance for projection （VIP）, four spectral bands including 1 760-1 700 cm-1, 1 660-1 640 cm-1, 1 580-1 540 cm-1 and 1 460-1 420 cm-1 were determined as important contributions to model prediction. Conclusion Application of the FTIR technique to detect postmortem spectral changes of the rat skin provides a novel proposal for PMI estimation.Objective To study the mechanism of rib fracture caused by landing on different parts of the trunk using finite element method, and to provide some new techniques and new ideas for the reconstruction of the whole process of falls from height. Methods The finite element method was used to study the rib fracture of human security model THUMS4.0 caused by landing on different parts of the trunk. Then the model was compared with actual cases and the mechanism of rib fracture caused by falls from height was analyzed from a biomechanical point of view. Results There were some differences in the stress and strain distribution as well as the rib fracture sites when different parts touched the ground. Ribs on both sides of the body were fractured when the front of the trunk touched the ground, and the fractures were mainly located in the junction of the ribs and costal cartilage and the midaxillary line area. When the right anterior part of the trunk touched the ground, rib fracture occurred first on the side that touched the ground, and rib fractures were mainly located in the area from the right midaxillary line to the posterior axillary line, and junction of ribs on both sides and costal cartilage. When the back of the trunk touched the ground, the fracture sites were mainly located on the back of the ribs on both sides. When the right posterior part of the trunk touched the ground, multiple rib fractures were likely to occur in the parts that touched the ground. The plastic strains were mainly concentrated at the fracture sites, while the von Mises stresses were not only concentrated at the fracture sites, but also at other sites. Conclusion There are some differences in rib fracture location sites and injury mechanisms when different parts of the trunk touch the ground.Objective To retrospectively analyze the forensic pathological postmortem examination and clinical data of children who died of viral pneumonia in identification of cause of death cases and to discuss the clinical characteristics and pathological features of viral pneumonia in children, in order to provide reference to pathological diagnosis of viral pneumonia in children caused by 2019 novel coronavirus （2019-nCoV） infection. Methods Postmortem examination data from 61 cases of children whose causes of death were identified as viral pneumonia in recent years were collected from the Center of Forensic Identification, Southern Medical University. The gender, age, clinical symptoms and pathological features were comparatively analyzed. Results Among the 61 cases of children who died of viral pneumonia, most were within 2 years old （83.61%）, and a large proportion died within 2 weeks after the onset of the disease （91.80%）. Gross changes in postmortem examination included respiratory mucosal hyperemia, pleural effusion, pulmonary swelling, variegated pulmonary pleura and serosa, as well as focal pulmonary hemorrhage and pulmonary edema.