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.

Correlation between severity of diabetic retinopathy and corneal SNP changes / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To investigate the correlation between severity of diabetic retinopathy(DR)and corneal sub-basal nerve plexus(SNP)changes. METHODS: There were 132 patients with 132 eyes in type 2 diabetes(T2DM)and 80 patients with 80 eyes in age-related cataract selected in our hospital from January 2018 to May 2021, among them, there were 52 non-diabetic retinopathy(NDR)patients with 52 eyes, 40 non proliferative diabetic retinopathy(NPDR)patients with 40 eyes and 40 proliferative diabetic retinopathy(PDR)patients with 40 eyes in T2DM. The general data and corneal laser scanning confocal microscopy were analyzed. Spearman rank correlation analysis was used to evaluate the correlation between DR clinical stage and nerve fiber length. RESULTS: There were no differences in gender and age comparisons among 4 groups(P>0.05). The diabetes duration in PDR group was significantly longer than NPDR group and NDR group(P<0.05). The diabetes duration in NPDR group was significantly longer than NDR group(P<0.05). The levels of fasting blood glucose and glycosylated hemoglobin in age-related cataract group were significantly lower than other three groups(P<0.05). The best corrected visual acuity in PDR group was significantly lower than NPDR group and NDR group(P<0.05). The best corrected visual acuity in NPDR group was significantly lower than NDR group(P<0.05). The length of nerve fibers in age-related cataract group was significantly higher than NDR group, NPDR group and PDR group(P<0.05). The length of nerve fibers in PDR group was significantly shorter than NPDR group(P<0.05). Spearman rank correlation analysis showed that there was a negative correlation between DR stage and nerve fiber length(rs=-0.347, P<0.001).CONCLUSION: There was a correlation between the severity of DR and the changes of corneal SNP. The length of nerve fibers in patients with PDR was significantly shorter than patients with NPDR; Both PDR and NPDR have a loss of neural structure and should pay attention to the evaluation and treatment of ocular surface lesions in the treatment of T2DM fundus lesions.

Analysis of clinical phenotype and genotype of Chinese children with disorders of sex development / 中华儿科杂志

Objective: To explore the heterogeneity and correlation of clinical phenotypes and genotypes in children with disorders of sex development (DSD). Methods: A retrospective study of 1 235 patients with clinically proposed DSD in 36 pediatric medical institutions across the country from January 2017 to May 2021. After capturing 277 DSD-related candidate genes, second-generation sequencing was performed to analyzed the heterogeneity and correlation combined with clinical phenotypes. Results: Among 1 235 children with clinically proposed DSD, 980 were males and 255 were females of social gender at the time of initial diagnosis with the age ranged from 1 day of age to 17.92 years. A total of 443 children with pathogenic variants were detected through molecular genetic studies, with a positive detection rate of 35.9%. The most common clinical phenotypes were micropenis (455 cases), hypospadias (321 cases), and cryptorchidism (172 cases) and common mutations detected were in SRD5A2 gene (80 cases), AR gene (53 cases) and CYP21A2 gene (44 cases). Among them, the SRD5A2 mutation is the most common in children with simple micropenis and simple hypospadias, while the AMH mutation is the most common in children with simple cryptorchidism. Conclusions: The SRD5A2 mutation is the most common genetic variant in Chinese children with DSD, and micropenis, cryptorchidism, and hypospadias are the most common clinical phenotypes. Molecular diagnosis can provide clues about the biological basis of DSD, and can also guide clinicians to perform specific clinical examinations. Target sequence capture probes and next-generation sequencing technology can provide effective and economical genetic diagnosis for children with DSD.

Effect of Yangjing Zhongyu Tang in Treating Kidney-Yin Deficiency Due to Repeated Implantation Failure and on LIF,VEGF,IL-1β,MCP-1 Levels / 中国实验方剂学杂志

Objective:To explore the clinical efficacy of Yangjing Zhongyu Tang in treating kidney-Yin deficiency due to repeated implantation failure (RIF). Method:Totally 70 patients with kidney yin deficiency due to repeated implantation failure (RIF) who received the periodic Frozen thawed embyo (FET) after in vitro fertilization (IVF) embryo cryopreservation were selected from the Integrative Medicine Reproductive and Genetics Center of Affiliated Hospital of Shandong University of Traditional Chinese Medicine(TCM). They were randomly divided into observation group and control group, with 35 cases in each group. All patients were received long protocol controlled ovarian hyperstimulation. Observation group was given Yangjing Zhongyu Tang from the 5th day to the 14th day of the menstrual cycle 1 month before transplantation, and continued to take it on the 5th day of the menstrual cycle in the month of the transplantation. Control group did not given TCM. After treatment, TCM syndrome scores, endometrial thickness, typing, uterine artery pulsation index (PI) and resistance index (RI) of HCG, endometrial secretion leukemia inhibitory factor (LIF), blood vessels endothelial growth factor (VEGF), interleukin-1β (IL-1β) and monocyte chemoattractant protein-1 (MCP-1), number of eggs obtained, fertilization rate and embryo transfer results were observed. Result:After treatment, the scores of TCM syndromes in observation group were significantly improved, with statistically significant difference (PPPβ and LIF of observation group were higher than those of control group, and the MCP-1 was lower than that of control group (PPConclusion:Yangjing Zhongyu Tang can significantly alleviate the clinical symptoms of patients with kidney-Yin deficiency due to RIF, effectively improve the type A endometrial morphology of RIF patients, reduce the uterine artery blood flow resistance, optimize endometrial implantation, and significantly improve the clinical pregnancy rate.

Effects of Electroacupuncture on Expression of PI3K/Akt/Foxo3a in Granulosa Cells from Women with Shen (Kidney) Deficiency Syndrome Undergoing in vitro Fertilization-Embryo Transfer / 中国结合医学杂志

OBJECTIVE@#To observe the effects of electroacupuncture (EA) on reproductive outcomes in women with Shen (Kidndy) deficiency syndrome after in vitro fertilization-embryo transfer (IVF-ET), and explore the underlying molecular mechanism.@*METHODS@#Sixty-six infertile patients with Shen deficiency syndrome undergoing IVF-ET were divided into EA or control groups according to a random table, 33 cases in each group. Before undergoing IVF, patients in the EA and control groups received EA therapy and placebo needle puncture, respectively, for 3 menstrual cycles. Shen deficiency syndrome scores were assessed. Other outcome measures included the number of retrieved oocytes and fertilization, high-quality embryo and clinical pregnancy rates. Follicular fluid was collected on the day of oocyte retrieval, and granulosa cell expression of phosphatidylinositide 3-kinases (PI3K), serine-threonine kinase (Akt) and forkhead box O3 (Foxo3a) mRNA were measured by reverse transcribed and quantitative real-time polymerase chain reaction.@*RESULTS@#Syndrome scores for pre- versus post-treatments decreased significantly (16.53±1.75 to 8.67±1.61) in the EA group (P<0.05), but showed no significant change in the control group (17.18±1.58 to 14.74±1.58). A significant difference in score change was found between the EA and control groups (P<0.05). High-quality embryo and clinical pregnancy rates were both increased in the EA group compared with the control group [69.15% (195/282) vs. 60.27% (176/292) and 66.67% (22/33) vs. 42.42% (14/33), respectively, P<0.05]. The fertilization rate was equivalent in EA and control groups. No difference was found in the number of retrieved oocytes between the two groups. Granulosa cell expression levels of PI3K and Akt mRNA were significantly increased in the EA group compared with the control group, while the expression of Foxo3a was reduced (all P<0.05).@*CONCLUSIONS@#For infertile patients with Shen deficiency syndrome undergoing IVF, EA for tonifying Shen as an adjunct treatment may alleviate clinical symptoms and improve the high-quality embryo rate. The EA-induced mechanism may involve regulation of PI3K/Akt/Foxo3a expression in granulosa cells to improve the developmental microenvironment of oocytes and inhibit granulosa cell apoptosis, possibly contributing to the improved clinical pregnancy rate (Registration No. ChiCTR 1800016217).

Suppression of mel18 enhances differentiation of acute myeloid leukemia cell line HL60 induced by cinnamaldehyde / 中国病理生理杂志

AIM:To investigate the effect of suppression of mel18 gene on the differentiation of human acute myeloid leukemia cell line HL 60 induced by cinnamaldehyde ( CA) .METHODS:HL60 cells were treated with low con-centration of CA or all-trans retinoic acid (ATRA).shRNAmel18 vector and shRNALuc control vector were employed to package lentiviruses which were then used to infect HL 60 cells.The virus-infected HL60 cells were treated with low con-centration of CA , and ATRA was used as a positive control of differentiation-inducing agent .The differentiation markers on the cell surface and cell cycle of virus-infected HL60 cells were analyzed by flow cytometry .Western blot was used to deter-mine the expression of MEL18, cyclin D1 and p27, as well as the phosphorylation level of Akt .RESULTS:Low concen-tration of CA and ATRA increased the expression of granulocytic differentiation marker CD 11b on the HL60 cells, with the decreased expression of MEL 18 in the HL60 cells.The expression of MEL18 decreased in shmel18 virus-infected HL60 cells (shmel18-HL60 cells), but did not change in shLuc-HL60 cells.The expression of CD11b on shmel18-HL60 cells increased with G 1-phase arrest , which went even higher after treatment with CA .The phosphorylation level of Akt and the expression of cyclin D1 decreased in shmel18-HL60 cells with the increase in the expression of p27.CONCLUSION:In-hibition of mel18 gene leads HL60 cell granulocytic differentiation .mel18 gene may affect the differentiation of HL 60 cells by regulating cyclin D1 and p27 via PI3K/Akt signaling pathway.PI3K/Akt signaling pathway is also involved in CA-in-duced differentiation of HL60 cells by suppressing mel18 gene expression.

GDC-0032 inhibits cell viability and induces DNA damage in U251 human glioma cells / 中国病理生理杂志

AIM:To investigate the effect of phosphatidylinostiol 3-kinase ( PI3K) inhibitor GDC-0032 on cell viability, cell cycle and DNA damage in human glioma U 251 cells.METHODS:The cell viability was analyzed by MTT assay.The cell cycle distribution of U251 cells was examined by flow cytometry .The protein expression was examined by Western blot.The expression and localization of γ-H2AX were determined by laser-scanning confocal microscopy .RE-SULTS:GDC-0032 inhibited the cell viability in a dose-dependent manner .U251 cells showed G 1 phase arrest accompa-nied with upregulation of p 27 protein after exposure to GDC-0032, while the expression of cell division cycle protein 2 (Cdc2) was inhibited.GDC-0032 treatment increased the formation of γ-H2AX foci and histone H2AX phosphorylation in the U251 cells.In addition, GDC-0032 upregulated the phosphorylation levels of mitogen-activated protein kinases , inclu-ding extracellular signal-regulated kinase ( ERK) and c-Jun N-terminal kinase ( JNK) , in the glioma cells , while the ex-pression of survivin was inhibited .CONCLUSION:GDC-0032 inhibits U251 cell growth by inhibition of cell viability and cell cycle progression.GDC-0032 also induces DNA damage of U251 cells.The anticancer activity of GDC-0032 is associ-ated with increasing the activity of ERK and JNK and downregulating the expression of survivin .

Suppression of mel18 enhances differentiation of acute myeloid leukemia cell line HL60 induced by cinnamaldehyde / 中国病理生理杂志

AIM:To investigate the effect of suppression of mel18 gene on the differentiation of human acute myeloid leukemia cell line HL 60 induced by cinnamaldehyde ( CA) .METHODS:HL60 cells were treated with low con-centration of CA or all-trans retinoic acid (ATRA).shRNAmel18 vector and shRNALuc control vector were employed to package lentiviruses which were then used to infect HL 60 cells.The virus-infected HL60 cells were treated with low con-centration of CA , and ATRA was used as a positive control of differentiation-inducing agent .The differentiation markers on the cell surface and cell cycle of virus-infected HL60 cells were analyzed by flow cytometry .Western blot was used to deter-mine the expression of MEL18, cyclin D1 and p27, as well as the phosphorylation level of Akt .RESULTS:Low concen-tration of CA and ATRA increased the expression of granulocytic differentiation marker CD 11b on the HL60 cells, with the decreased expression of MEL 18 in the HL60 cells.The expression of MEL18 decreased in shmel18 virus-infected HL60 cells (shmel18-HL60 cells), but did not change in shLuc-HL60 cells.The expression of CD11b on shmel18-HL60 cells increased with G 1-phase arrest , which went even higher after treatment with CA .The phosphorylation level of Akt and the expression of cyclin D1 decreased in shmel18-HL60 cells with the increase in the expression of p27.CONCLUSION:In-hibition of mel18 gene leads HL60 cell granulocytic differentiation .mel18 gene may affect the differentiation of HL 60 cells by regulating cyclin D1 and p27 via PI3K/Akt signaling pathway.PI3K/Akt signaling pathway is also involved in CA-in-duced differentiation of HL60 cells by suppressing mel18 gene expression.

GDC-0032 inhibits cell viability and induces DNA damage in U251 human glioma cells / 中国病理生理杂志

AIM:To investigate the effect of phosphatidylinostiol 3-kinase ( PI3K) inhibitor GDC-0032 on cell viability, cell cycle and DNA damage in human glioma U 251 cells.METHODS:The cell viability was analyzed by MTT assay.The cell cycle distribution of U251 cells was examined by flow cytometry .The protein expression was examined by Western blot.The expression and localization of γ-H2AX were determined by laser-scanning confocal microscopy .RE-SULTS:GDC-0032 inhibited the cell viability in a dose-dependent manner .U251 cells showed G 1 phase arrest accompa-nied with upregulation of p 27 protein after exposure to GDC-0032, while the expression of cell division cycle protein 2 (Cdc2) was inhibited.GDC-0032 treatment increased the formation of γ-H2AX foci and histone H2AX phosphorylation in the U251 cells.In addition, GDC-0032 upregulated the phosphorylation levels of mitogen-activated protein kinases , inclu-ding extracellular signal-regulated kinase ( ERK) and c-Jun N-terminal kinase ( JNK) , in the glioma cells , while the ex-pression of survivin was inhibited .CONCLUSION:GDC-0032 inhibits U251 cell growth by inhibition of cell viability and cell cycle progression.GDC-0032 also induces DNA damage of U251 cells.The anticancer activity of GDC-0032 is associ-ated with increasing the activity of ERK and JNK and downregulating the expression of survivin .

Real-time Vessel Navigation Using Indocyanine Green Fluorescence during Robotic or Laparoscopic Gastrectomy for Gastric Cancer

PURPOSE: Identification of the infrapyloric artery (IPA) type is a key component of pylorus-preserving gastrectomy. As the indocyanine green (ICG) fluorescence technique is known to help visualize blood vessels and flow during reconstruction, we speculated that this emerging technique would be helpful in identifying the IPA type. MATERIALS AND METHODS: From August 2015 to February 2016, 20 patients who underwent robotic or laparoscopic gastrectomy were prospectively enrolled. After intravenous injection of approximately 3 mL of ICG (2.5 mg/mL), a near-infrared fluorescence apparatus was applied. The identified shape of the IPA was confirmed by examining the actual anatomy following infrapyloric dissection. RESULTS: The mean interval time between ICG injection and visualization of the artery was 22.2 seconds (range, 14–30 seconds), and the mean duration of the arterial phase was 16.1 seconds (range, 9–30 seconds). The overall positive predictive value (PPV) of ICG fluorescence in identifying the IPA type was 80% (16/20). The IPA type was incorrectly predicted in four patients, all of whom were obese with a body mass index (BMI) of more than 25 kg/m². CONCLUSIONS: Our preliminary results indicate that intraoperative vascular imaging using the ICG fluorescence technique may be helpful for robotic or laparoscopic pylorus-preserving gastrectomy.

Case Report of an Adult Patient Who Underwent a Serial Transverse Enteroplasty Procedure for Short Bowel Syndrome Following an Esophagectomy and Total Gastrectomy

Since its introduction as an alternative intestinal lengthening technique, the serial transverse enteroplasty (STEP) procedure has been used increasingly as the surgical treatment of choice for children with short bowel syndrome (SBS). On the other hand, there are few report of its efficacy in adults with SBS, particularly those who have previously undergone a gastrectomy. This case report describes a 34-year-old woman with a short bowel after an esophagectomy and total gastrectomy due to lye ingestion followed by an extensive intestinal resection due to small bowel strangulation. The STEP procedure was performed successfully and the small intestine was lengthened from 55 to 75 cm. The patient tolerated the procedure well and was weaned off total parenteral nutrition. The frequency and characteristics of diarrhea improved, and her weight remained acceptable via management with intermittent parenteral nutritional support for 6 months postoperatively. This case suggests that the STEP procedure should be considered for gastrectomized patients with SBS.

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．

Clinical significance of serum CEA, CA125 and CA72-4 in gastric carcinoma with peritoneal metastasis / 中国癌症杂志

Background and purpose: Peritoneal metastasis of gastric cancer is mainly discovered in the ad-vanced cancer. Nonetheless, the clinical applicability of each tumor biomarker in peritoneal metastasis of gastric cancer is still ambiguous. Therefore, this study investigated the diagnostic value and clinical significance of CEA, CA125 and CA72-4 in gastric carcinoma patients with peritoneal metastases. Methods: A total of 108 gastric carcinoma patients with peritoneal metastases from Jan. 2008 to Dec. 2013 were studied. All patients were diagnosed by imaging, operations and pathological examination, and also received intravenous or intraperitoneal chemotherapy. Serum tumor markers such as CEA, CA125 and CA72-4 were determined during diagnosis and before each chemotherapy. The diagnostic sensitivity of single marker and combined detection with 2 or 3 markers were analyzed. The correlations among the serum tumor markers and clinical pathological factors, chemotherapeutic effects and survival time were analyzed. Results: Positive rates of CEA, CA125 and CA72-4 were 20.4%, 46.3% and 45.4% in gastric cancer patients with peritoneal metastases, respectively. For these patients, the positive rates of CEA/CA125, CEA/CA72-4, CA125/CA72-4 and CEA/CA125/CA72-4 were 54.7%, 52.8%, 69.5% and 79.6%, respectively. The combined detection of 3 tumor markers was much better than single marker detection (P<0.05). Positive rates of CEA, CA125 and CA72-4 were correlated with the ECOG scale (P<0.05). Positive rate of CA125 was associated with ascites (P<0.001), while positive rate of CA72-4 was associated with ovarian metastasis (P<0.05). Median survival time of patients with positive rates of CEA, CA125 and CA72-4 was significantly lower than that of the patients with normal levels of these markers (P<0.05). Compared with pre-treatment, the levels of all three tumor markers significantly declined after three cycles of chemo-therapy (P<0.05). The decline in CA125 level after chemotherapy was significantly correlated with decreased amount of ascites (P<0.05). The tumor markers turned negative after 3 cycles chemotherapy in patients with positive markers upon initial diagnosis, their survival was significantly prolonged (P<0.001). Conclusion: Combined detection of serum CEA, CA125 and CA72-4 can significantly promote diagnostic rate of gastric cancer with peritoneal metastasis, and may be helpful in evaluating chemotherapeutic effects and predicting prognosis.

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.

Can Robotic Gastrectomy Surpass Laparoscopic Gastrectomy by Acquiring Long-Term Experience? A Propensity Score Analysis of a 7-Year Experience at a Single Institution

PURPOSE: It is hypothesized that robotic gastrectomy may surpass laparoscopic gastrectomy after the operators acquire long-term experience and skills in the manipulation of robotic arms. This study aimed to evaluate the long-term learning curve of robotic distal gastrectomy (RDG) for gastric cancer compared with laparoscopic distal gastrectomy (LDG). MATERIALS AND METHODS: From October 2008 to December 2015, patients who underwent LDG (n=809) were matched to patients who underwent RDG (n=232) at a 1:1 ratio, by using a propensity score matching method after stratification for the operative year. The surgical outcomes, such as trends of operative time, blood loss, and complication rate, were compared between the two groups. RESULTS: The RDG group showed a longer operative time (171.3 minutes vs. 147.6 minutes, P<0.001) but less estimated blood loss (77.6 ml vs. 116.6 ml, P<0.001). The complication rate and postoperative recovery did not differ between the two groups. The RDG group showed a longer operative time and similar estimated blood loss compared with the LDG group after 5 years of experience (operative time: 159.2 minutes vs. 136.0 minutes in 2015, P=0.003; estimated blood loss: 72.9 ml vs. 78.1 ml in 2015, P=0.793). CONCLUSIONS: In terms of short-term surgical outcomes, RDG may not surpass LDG after a long-term experience with the technique.

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.