Objective To predict biomechanical responses of neck injuries under different loading conditions based on the finite element model of the 6-year-old pediatric neck. Methods The finite element model of the 6-year-old pediatric neck with real anatomical structural muscles was developed, according to the CT images. The model was verified by reconstructing the dynamic tensile test of different cervical spine segments, the tensile test of full cervical spine and the low speed impact experiment of the pediatric volunteers. Results The force-displacement curves, obtained from the simulations on tensile test of different cervical spine segments and tensile test of full cervical spine, were in good agreement with the experimental curves. The head angular velocity-time curve obtained from simulations on pediatric volunteer was consistent with the corridor obtained from experimental data. Conclusions The model is validated and can be used for studying the biomechanical responses and injury mechanism of pediatric neck under different loading conditions.

OBJECTIVES: To reconstruct the cases of acceleration craniocerebral injury caused by blunt in forensic cases by finite element method (FEM), and to study the biomechanical mechanism and quantitative evaluation method of blunt craniocerebral injury. METHODS: Based on the established and validated finite element head model of Chinese people, the finite element model of common injury tool was established with reference to practical cases in the forensic identification, and the blunt craniocerebral injury cases were reconstructed by simulation software. The cases were evaluated quantitatively by analyzing the biomechanical parameters such as intracranial pressure, von Mises stress and the maximum principal strain of brain tissue. RESULTS: In case 1, when the left temporal parietal was hit with a round wooden stick for the first time, the maximum intracranial pressure was 359 kPa; the maximum von Mises stress of brain tissue was 3.03 kPa at the left temporal parietal; the maximum principal strain of brain tissue was 0.016 at the left temporal parietal. When the right temporal was hit with a square wooden stick for the second time, the maximum intracranial pressure was 890 kPa; the maximum von Mises stress of brain tissue was 14.79 kPa at the bottom of right temporal lobe; the maximum principal strain of brain tissue was 0.103 at the bottom of the right temporal lobe. The linear fractures occurred at the right temporal parietal skull and the right middle cranial fossa. In case 2, when the forehead and left temporal parietal were hit with a round wooden stick, the maximum intracranial pressure was 370 kPa and 1 241 kPa respectively, the maximum von Mises stress of brain tissue was 3.66 kPa and 26.73 kPa respectively at the frontal lobe and left temporal parietal lobe, and the maximum principal strain of brain tissue was 0.021 and 0.116 respectively at the frontal lobe and left temporal parietal lobe. The linear fracture occurred at the left posterior skull of the coronary suture. The damage evaluation indicators of the simulation results of the two cases exceeded their damage threshold, and the predicted craniocerebral injury sites and fractures were basically consistent with the results of the autopsy. CONCLUSIONS The FEM can quantitatively evaluate the degree of blunt craniocerebral injury. The FEM combined with traditional method will become a powerful tool in forensic craniocerebral injury identification and will also become an effective means to realize the visualization of forensic evidence in court.
Humans ; Finite Element Analysis ; Biomechanical Phenomena ; Wounds, Nonpenetrating ; Head ; Craniocerebral Trauma

ObjectiveTo study the correlation of high-risk human papillomavirus 16 and 18 (HPV16/18) infections with the risk of prostate cancer (PCa) and their association with the clinicopathologic indexes of PCa.

METHODSWe collected tissue samples from 75 cases of PCa and 73 cases of benign prostatic hyperplasia (BPH). We detected HPV16/18 infections in the samples by immunohistochemistry and PCR combined with reverse dot blot (RDB) assay.

RESULTSImmunohistochemistry revealed 16 cases of HPV16/18 positive in the PCa (21.3%) and 7 cases in the BPH samples (9.5%), with statistically significant difference between the two groups (P=0.049). PCR combined with RDB assay showed 17 cases of HPV16 infection (22.6%) and 13 cases of HPV18 infection (17.8%), including 4 cases of HPV16/18 positive, in the PCa group, remarkably higher than 6 cases of HPV16 infection (8.2%), 3 cases of HPV18 infection (4.1%) and no HPV16/18 positive in the BPH controls (P=0.001). No significant differences were observed between the result of immunohistochemistry and that of PCR combined with RDB assay (P=0.069). The risk of HPV16/18 infections was found to be correlated with the clinical T-stage and Gleason score of PCa (P<0.05 ) but not with the patient's age, PSA level or lymph node metastasis (P>0.05 ).

CONCLUSIONSHigh-risk HPV16/18 infections are correlated with the risk of prostate cancer.

Human papillomavirus 16 ; Human papillomavirus 18 ; Humans ; Immunohistochemistry ; Lymphatic Metastasis ; Male ; Neoplasm Grading ; Papillomavirus Infections ; epidemiology ; Polymerase Chain Reaction ; Prostatic Hyperplasia ; epidemiology ; virology ; Prostatic Neoplasms ; epidemiology ; virology

OBJECTIVES: To analyze and predict the striking velocity range of stick blunt instruments in different populations, and to provide basic data for the biomechanical analysis of blunt force injuries in forensic identification. METHODS: Based on the Photron FASTCAM SA3 high-speed camera, Photron FASTCAM Viewer 4.0 and SPSS 26.0 software, the tester's maximum striking velocity of stick blunt instruments and related factors were calculated and analyzed, and inputed to the backpropagation (BP) neural network for training. The trained and verified BP neural network was used as the prediction model. RESULTS: A total of 180 cases were tested and 470 pieces of data were measured. The maximum striking velocity range was 11.30-35.99 m/s. Among them, there were 122 female data, the maximum striking velocity range was 11.63-29.14 m/s; there were 348 male data, the maximum striking velocity range was 20.11-35.99 m/s. The maximum striking velocity of stick blunt instruments increased with the increase of weight and height, but there was no obvious increase trend in the male group; the maximum striking velocity decreased with age, but there was no obvious downward trend in the female group. The maximum striking velocity of stick blunt instruments has no significant correlation with the material and strike posture. The root mean square error (RMSE), the mean absolute error (MAE) and the coefficient of determination (R²) of the prediction results by using BP neural network were 2.16, 1.63 and 0.92, respectively. CONCLUSIONS The prediction model of BP neural network can meet the demand of predicting the maximum striking velocity of different populations.
Male ; Humans ; Female ; Neural Networks, Computer ; Software ; Wounds, Nonpenetrating ; Forensic Medicine

Objective: To investigate the incidence and risk factors of systemic allergic reactions induced by subcutaneous immunotherapy (SCIT) in patients undergoing SCIT injections in Peking Union Medical College Hospital (PUMCH). Methods: This is a single center retrospective cohort study. Using the outpatient information system of PUMCH, the demographic information and injection-related reaction data of patients undergoing SCIT injection in Allergy Department of PUMCH from December 2018 to December 2022 were retrospectively analyzed to count the incidence and risk factors of systemic allergic reactions caused by SCIT. Mann-Whitney nonparametric test or chi-square test was used for single-factor analysis, and multiple logistic regression was used for multiple-factor analysis. Results: A total of 2 897 patients received 18 070 SCIT injections in Allergy Department during the four years, and 40 systemic allergic reactions occurred, with the overall incidence rate of 0.22%. The incidence of systemic allergic reaction was 0.37% when using imported dust mite preparation and 0.15% when using domestic multi-component allergen preparation. The risk factors significantly related with SCIT-induced systemic allergic reactions in patients using imported dust mite preparation were age less than 18 years old (OR=3.186,95%CI: 1.255-8.085), highest injection concentration (OR value could not be calculated because all patients with systemic reactions were injected with highest concentration), and large local reaction in previous injection (OR=22.264,95%CI: 8.205-60.411). The risk factors for SCIT-induced systemic allergic reactions in patients using domestic allergen preparation were 5 or more types of allergens (OR=3.455,95%CI: 1.147-10.402), highest injection concentration (OR=3.794,95%CI: 1.226-11.740) and large local reaction in previous injection (OR=63.577,95%CI: 22.248-181.683). However, SCIT injection in pollen allergic patients during the pollen season did not show a correlation with systemic allergic reaction. Conclusion: The incidence of SCIT-induced systemic allergic reactions was low in the Chinese patient population of this study. Patients with one or more risk factors, such as multiple allergen injection, highest injection concentration, large local reaction in previous injection, should be given high attention and vigilance against systemic allergic reactions.
Humans ; Allergens ; Asian People ; Desensitization, Immunologic/adverse effects* ; Hypersensitivity/epidemiology* ; Retrospective Studies

Objective: To investigate the incidence and risk factors of systemic allergic reactions induced by subcutaneous immunotherapy (SCIT) in patients undergoing SCIT injections in Peking Union Medical College Hospital (PUMCH). Methods: This is a single center retrospective cohort study. Using the outpatient information system of PUMCH, the demographic information and injection-related reaction data of patients undergoing SCIT injection in Allergy Department of PUMCH from December 2018 to December 2022 were retrospectively analyzed to count the incidence and risk factors of systemic allergic reactions caused by SCIT. Mann-Whitney nonparametric test or chi-square test was used for single-factor analysis, and multiple logistic regression was used for multiple-factor analysis. Results: A total of 2 897 patients received 18 070 SCIT injections in Allergy Department during the four years, and 40 systemic allergic reactions occurred, with the overall incidence rate of 0.22%. The incidence of systemic allergic reaction was 0.37% when using imported dust mite preparation and 0.15% when using domestic multi-component allergen preparation. The risk factors significantly related with SCIT-induced systemic allergic reactions in patients using imported dust mite preparation were age less than 18 years old (OR=3.186,95%CI: 1.255-8.085), highest injection concentration (OR value could not be calculated because all patients with systemic reactions were injected with highest concentration), and large local reaction in previous injection (OR=22.264,95%CI: 8.205-60.411). The risk factors for SCIT-induced systemic allergic reactions in patients using domestic allergen preparation were 5 or more types of allergens (OR=3.455,95%CI: 1.147-10.402), highest injection concentration (OR=3.794,95%CI: 1.226-11.740) and large local reaction in previous injection (OR=63.577,95%CI: 22.248-181.683). However, SCIT injection in pollen allergic patients during the pollen season did not show a correlation with systemic allergic reaction. Conclusion: The incidence of SCIT-induced systemic allergic reactions was low in the Chinese patient population of this study. Patients with one or more risk factors, such as multiple allergen injection, highest injection concentration, large local reaction in previous injection, should be given high attention and vigilance against systemic allergic reactions.
Humans ; Allergens ; Asian People ; Desensitization, Immunologic/adverse effects* ; Hypersensitivity/epidemiology* ; Retrospective Studies