Strike Velocity Prediction of Stick Blunt Instruments Based on Backpropagation Neural Network / 法医学杂志

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.

Reconstruction and Quantitative Evaluation of Blunt Injury Cases by Finite Element Method / 法医学杂志

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.

Differentially expressed microRNAs in the testis of male rats exposed to cigarette smoke: Screening and function verification / 中华男科学杂志

Objective@#To screen differentially expressed miRNAs in the testis of male rats exposed to cigarette smoke (CS) and identify the early molecular markers of CS-induced apoptosis of testicular cells.@*METHODS@#We randomly divided 200 SPF male SD rats into blank control and low-dose (10 non-filter cigarettes/d), medium-dose (20 non-filter cigarettes/d) and high-dose (30 non-filter cigarettes/d) CS exposure groups. After 2, 4, 6, 8 and 12 weeks of CS exposure, we observed the histopathological changes of the testis by HE staining, detected the apoptosis of the testicular cells by TUNEL, and determined the expressions of caspase-3 and caspase-9 in the testis tissue by immunohistochemistry, RT-PCR and Western blot. Based on the laboratory results, we selected 4 testicular samples from the 12-week high-dose group and another 4 from the control for miRNA microarray-based screening, bioinformatics analysis, and verification of differentially expressed miRNAs in all the animals by RT-PCR.@*RESULTS@#Compared with the controls, the CS-exposed rats showed dose- and time-dependent increase in the atrophy of the testis and significantly increased number of apoptotic testis cells from the 6th week of exposure (P < 0.05), with dramatically up-regulated expressions of caspase-3 (P < 0.01) and caspase-9 protein and mRNA (P < 0.05) in the testis tissue. Microarray-based screening and RT-PCR revealed 5 differentially expressed miRNAs in the testis of the CS-exposed rats, of which miR-138-5p, miR-181d-5p, miR-19a-3p and miR-3588 were down-regulated, and miR-155-5p up-regulated, and the target genes of the differentially expressed miRNAs positively regulated the apoptosis of the testicular cells.@*CONCLUSIONS@#The differentially expressed miRNAs miR-155-5p, miR-138-5p, miR-181d-5p, miR-19a-3p and miR-3588 regulate CS-induced apoptosis of testicular cells, and may become biomarkers for early diagnosis and prognosis of CS-induced spermatogenesis obstruction.《.

Effect of serum containing Xihuang pill on proliferation of human breast cancer cell line MDA-MB-435 and MCF-7 Cells / 中国中药杂志

To study the effect of serum containing Xihuang pill on the proliferation of human breast cancer cell lines MDA-MB-435 and MCF-7 and the gene and protein expressions of Bcl-2, Bax, TP53, in order to explore the effect and mechanism of Xihuang pill in resisting breast cancer. The serum of the rats was prepared by the method of MTT assay. The expressions of Bcl-2 and Bax were detected by RT-PCR. The serum levels of Bcl-2 and Bax and the mRNA expression of TP53 were detected by immunofluorescence. The rats with serum containing Xihuang pill could inhibit the proliferation of MDA-MB-435 cells and MCF-7 cells (<0.05). The serum containing Xihuang pill increased TP53 and Bax in MDA-MB-435 cells (<0.05), and the ratio of Bcl-2/Bax was decreased (<0.05). Meanwhile, the serum containing Xihuang pill could up-regulate the mRNA expression of Bax in MCF-7 cells and decrease the expression of Bcl (<0.05), but there was no significant difference between the expression of TP53mRNA and Bax protein expressions after the treatment of MCF-7 cells with Xihuang pill serum. Serum containing Xihuang pill can induce the apoptosis of human breast cancer cells, and the mechanism of estrogen receptor-negative breast cancer cell apoptosis may be induced by up-regulating the mRNA expression of TP53, which can induce the expression of Bax and promote the metastasis of Bax to mitochondria, and ultimately play the role of inducing apoptosis.

Development and validation for finite element model of one-year-old toddler head with detailed anatomical structures / 医用生物力学

Objective To explore the brain injury mechanism and enrich the database of human finite element (FE) biomechanical model by developing the FE model of one-year-old toddler head. Methods Based on CT data from Chinese one-year-old toddler head with substantial and detailed information, the head model with detailed anatomical structure was constructed by using the medical software Mimics to get the head geometry data, as well as the reverse engineering software to divide NURBS surface and build the geometric model. Finally, the FE pre-processing software was used mesh the model. The FE model of one-year-old toddle head was validated by data from anatomic and cadaver experiments, and was used for preliminary analysis on damage mechanism of one-year-old toddler head. Results The FE model of Chinese one-year-old male toddler head was developed, which included and distinguished the gray matter and white matter of brain and cerebellum, hippocampus, fontanel, sagittal suture, coronal suture, brainstem and ventricles. The cadaver head static compression experiments and drop experiments were reconstructed by using this head model, and the results showed that the FE model of head had similar mechanical properties with the cadaver, which proved the validity of the FE model. Simulation results showed that skull stiffness and skull injury severity varied with different compression rates. Conclusions The FE model of one-year-old toddler head with detailed anatomical structures is of great biofidelity. The FE head model can be used to further investigate the detailed injury mechanism of deep brain tissues, especially for the closed craniocerebral injury, which provides an effective way and tool for the related research and clinical application.

Analysis of growth plate material property effect on knee injury of six-year-old child occupant / 医用生物力学

Objective To develop the finite element model of six-year-old child occupant lower extremity with higher biofidelity and validate the model of knee joints, as well as analyze the biomechanical responses of growth plate under frontal impact load and injury mechanisms of the knee joint by using this model. Methods The six-year-old child occupant lower extremity with growth plate was modeled based on children’s anatomy and CT images, and corresponding material properties of the lower extremity model were assigned．The model was validated according to biomechanical experiments by Kerrigan et al. and Haut et al. and then was used to analyze the injury results of growth plate with different material properties. Results The model validation was qualified by comparing the curves from the experimental and simulation results．The growth plates at knee regions could change injury patterns of the child occupant lower extremity fracture. The material properties of growth plate could affect threshold of axial damage of the femur as well as relative position of the fracture． Conclusions The validated model can be used for related study and application on biomechanical responses and injury mechanisms of six-year-old child occupant lower extremities．

Analysis of growth plate material property effect on knee injury of six-year-old child occupant / 医用生物力学

Objective To develop the finite element model of six-year-old child occupant lower extremity with higher biofidelity and validate the model of knee joints,as well as analyze the biomechanical responses of growth plate under frontal impact load and injury mechanisms of the knee joint by using this model.Methods The sixyear-old child occupant lower extremity with growth plate was modeled based on children's anatomy and CT images,and corresponding material properties of the lower extremity model were assigned.The model was validated according to biomechanical experiments by Kerrigan et aL and Haut et aL and then was used to analyze the injury results of growth plate with different material properties.Results The model validation was qualified by comparing the curves from the experimental and simulation results.The growth plates at knee regions could change injury patterns of the child occupant lower extremity fracture.The material properties of growth plate could affect threshold of axial damage of the femur as well as relative position of the fracture.Conclusions The validated model can be used for related study and application on biomechanical responses and injury mechanisms of sixyear-old child occupant lower extremities.

Analysis of growth plate material property effect on knee injury of six-year-old child occupant / 医用生物力学

Objective To develop the finite element model of six-year-old child occupant lower extremity with higher biofidelity and validate the model of knee joints,as well as analyze the biomechanical responses of growth plate under frontal impact load and injury mechanisms of the knee joint by using this model.Methods The sixyear-old child occupant lower extremity with growth plate was modeled based on children's anatomy and CT images,and corresponding material properties of the lower extremity model were assigned.The model was validated according to biomechanical experiments by Kerrigan et aL and Haut et aL and then was used to analyze the injury results of growth plate with different material properties.Results The model validation was qualified by comparing the curves from the experimental and simulation results.The growth plates at knee regions could change injury patterns of the child occupant lower extremity fracture.The material properties of growth plate could affect threshold of axial damage of the femur as well as relative position of the fracture.Conclusions The validated model can be used for related study and application on biomechanical responses and injury mechanisms of sixyear-old child occupant lower extremities.

Effects from material parameters of craniocerebral tissues on impact responses of child head / 医用生物力学

Objective In view of the uncertainties of material parameters for child craniocerebral tissues, the effects of such parameters on responses of child head under direct impact loads were investigated. Methods The impact simulation experiments were conducted under direct impact loads by using a validated finite element model of 3-year-old child head. Taguchi orthogonal method and variance analysis were performed to analyze the material properties of craniocerebral tissues in child head. Results Elastic modulus of the skull had statistically significant effects on impact responses of child head. With the skull elastic modulus increasing, the coup pressure decreased significantly (P=0.000), whereas the contrecoup pressure (P=0.000) and maximum Von Mises stress of the skull increased significantly (P=0.000). The linear viscoelastic material parameters of brain tissues also had statistically significant effects on impact responses of child head. With the increase of the short-time shear modulus of brain tissues, the maximum shear stress of brain tissues increased significantly (P=0.000) whereas the maximum principal strain decreased significantly (P=0.000). Conclusions These statistical analysis results can provide references for selecting material parameter of craniocerebral tissues in finite element model of child head, which will be helpful to improve diagnosis accuracy of brain injuries such as concussion difficult to be definitely diagnosed when using brain CT images in clinic.

Development and validation of finite element model for the 6-year-old pediatric neck / 医用生物力学

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.

Pharmacological activity of Terminalia chebula / 中国中药杂志

Terminalia chebula Retz, known as the "king" of Mongolian and Tibetan medicines, is a drug for a wide range of diseases. The main chemical components of myrobalan include triterpene acid, galloyl glucose, anthraquinonoid. The modern pharmacological studies show that myrobalan has multiple biological activities, including antimicrobial, anti-inflammatory, antioxidation as well as anti-tumor. Based on domestic and foreign literatures in recent years, this paper gave a review on the advance of studies for pharmacological activity of T. chebula. and its active components, so as to provide a reference for the in-depth studies on the pharmacological action of myrobalan, and the further development and utilization of myrobalan.

Changes of mechanical pain threshold in rats with experimental autoimmune prostatitis / 中华男科学杂志

<p><b>OBJECTIVE</b>To observe the changes of the mechanical pain threshold in the rat model of autoimmune prostatitis, explore the mechanism of autoimmune prostatitis pain and offer some animal experimental evidence for the drug therapy of the condition.</p><p><b>METHODS</b>Twenty male Wistar rats weighing 180 - 220 g were divided into a model and a control group. The autoimmune prostatitis model was established by subcutaneous injection of an extract of male rat prostate glands (RPG) at 60 mg/ml in Freund's complete adjuvant (FCA) and pertussis-diphtheria-tetanus vaccine at 0 and 30 days, respectively. Mechanical tactile hyperalgesia was measured once a week using Von Frey Filaments from the beginning of the study. At 8 weeks after modeling, the rats were sacrificed and the prostate tissues harvested for observation of histomorphological changes by HE staining.</p><p><b>RESULTS</b>HE staining revealed different degrees of benign prostatitis in the model rats. Compared with the controls, the mechanical pain threshold in the model rats was significantly decreased with the increased time of modeling, from (65.52 +/- 6.27) g at 0 week to (23.67 +/- 4.09) g at 8 weeks (P < 0.01). Statistically significant differences were found in the variation trend at different time points between the two groups (P < 0.01).</p><p><b>CONCLUSION</b>Autoimmune prostatitis models were successfully established in rats and hyperalgesia was induced after modeling.</p>

Simulation of dynamic tests on long bones of lower limbs based on finite element model / 医用生物力学

Objective To study the failure tolerance in long bones of lower limbs under dynamic loads. Methods Based on the finite element (FE) model of lower limb for Chinese people, the dynamic three-point bending test on the femur, tibia, leg and thigh was conducted , and the FE model was validated against the cadaveric experiment. Results The force-displacement curves between FE simulation and cadaveric experimental results for bending tests were correlated. The contact forces on femur, tibia, thigh and leg with failure tolerance were 4.29, 3.94, 4.81 and 4.086 kN, respectively，and the displacements from the impactor were 17.78, 34, 52.1, and 47.06 mm, respectively. The simulation results were correlated well with those in dynamic cadaveric experiments. Conclusions This study validated the effectiveness of the FE model, which would lay a good foundation for the further research on validation of FE model of knee joint and whole lower limb, and provide the theoretical references for the protection of pedestrians in crashes.

Erectile function of male rats in different age groups: an experimental study / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the relationship between aging and erectile function changes in rats in order to establish a rat model of aging-related erectile dysfunction (ED).</p><p><b>METHODS</b>Eighty male Wistar rats were equally divided into four age groups (3-, 6-, 12- and 18-month) and treated with intragastric administration of sildenafil citrate (Sn) for penile erection tests. Twenty 3-month-old female Wistar rats were randomized to four groups as oestrous rat models. We recorded the rate and frequency of penile erections of the male rats in different age groups.</p><p><b>RESULTS</b>The rates of penile erection were 85%, 75%, 40% and 30% and erectile frequencies were 2.27 +/- 0.80, 2.00 +/- 0.61, 1.40 +/- 0.51 and 1.29 +/- 0.49 in the 3-, 6-, 12- and 18-month rats, respectively, with statistically significant differences among different age groups (P < 0.01). And their erectile function exhibited a tendency to decrease with the increase of age. Besides, comparison of the 3-month with the 6-, 12- and 18-month groups showed significantly reduced erectile function in the 18-month rats (P < 0.05) but no remarkable difference between the 3-month and the 6- and 12-month groups (P > 0.05).</p><p><b>CONCLUSION</b>Aging is one of the main risk factors of rat erectile dysfunction, and 18-month-old male rats are qualified for the establishment of the rat model of aging-related erectile dysfunction.</p>

Erythropoietin gene-modified conditioned medium of human mesenchymal cells promotes hematopoietic development from human embryonic stem cells / 中国实验血液学杂志

The study was aimed to investigate the effect of deriving hematopoietic cells from human embryonic stem cells (hESCs) by the erythropoietin gene-modified conditioned medium of human mesenchymal cells. The mesenchymal stem cells (MSCs) steadily expressing EPO were established by lentiviral system. The expression of exogenous EPO was detected by RT-PCR and Western blot. After suspension culture, hESCs developed into embryonic bodies (EBs). Then the EB cells were cultured in conditional medium. The hESCs-derived hematopoietic cells were analyzed by immunofluorescence, CFU assay and RT-PCR. The results indicated that the exogenous EPO successfully expressed in the EPO transfected MSCs (EPO/MSCs). The supernatant from EPO/MSCs increased CD34(+) cell population and the expression of globin, and enhanced colony forming unit incidence. These effects were obviously higher than that of control. It is concluded that the EPO gene-modified conditioned medium of human mesenchymal cells can induce the hESCs to differentiate into hematopoietic cells.

Observation on the therapeutic effect of warming needle moxibustion on knee osteoarthritis / 中国针灸

<p><b>OBJECTIVE</b>To compare clinical therapeutic effects of warming needle moxibustion and acupuncture plus TDP radiation on knee osteoarthritis.</p><p><b>METHODS</b>Eighty cases conforming with the diagnostic criteria for knee osteoarthritis were randomly divided into a warming needle moxibustion group and an acupuncture plus TDP radiation group. In the two groups, Dubi (ST 35), Xiyan (EX-LE), Yanglingquan (GB 34),etc. were selected and the treatment was given once every other day, 10 sessions constituting one course. After treatment of 2 courses, their therapeutic effects were compared.</p><p><b>RESULTS</b>The clinically basic recovery rate was 30.0% in the warming needle moxibustion group and 10.0% in the acupuncture plus TDP radiation group, with a very significant difference between the two groups (P < 0.01).</p><p><b>CONCLUSION</b>Warming needle moxibustion is an effective therapy for knee osteoarthritis.</p>

Analysis on the characteristics of blood serum Ab-IgG detective result of severe acute respiratory syndrome patients in Guangzhou, China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To probe blood serum Ab-IgG characteristics of severe acute respiratory syndrome (SARS) patients in Guangzhou and investigate the related factors.</p><p><b>METHODS</b>The serum of such population diagnosed as SARS convalescent patients, non-SARS patients, family consanguineous contraction persons, wild animal and vegetable salesman and community common people was collected. The lab detective method of ELISA was adopted for these serum samples. And the epidemic investigations for the SARS patients were also carried out.</p><p><b>RESULTS</b>Of these populations, the detective rate of Ab-IgG for the clinic diagnosed SARS patients, which was 53.7%; That for the wild animal salesman and community common people were 16.7% and 0.9%, respectively. Among the clinic diagnosed SARS patients, the positive antibody detective rate was 90.4% for those which had specific contact history or infectivity, which was higher than that for other population. Among the specific contact history or infectivity cases, the antibody positive rate for the young and the old was lower than that for the adult. Meanwhile the difference did not exist among other cases. The antibody positive rate was identical between the male and the female. And the antibody detective rate was decreased by the month.</p><p><b>CONCLUSION</b>As a whole SARS-CoV Ab-IgG detective rate for the clinic diagnosed SARS patients was 53.7% only. The reasons for that mainly lie in the wrong clinic diagnosis besides these factors such as age, hormone use and reagent and so on. The combination of lab detection results and epidemic investigation was propitious to the diagnosis veracity. It was impossible for the sub-clinic infection of SARS-CoV virus. The importance in the virus transmitting course need to be further studied.</p>