Objective Few studies are reported on the construction of a finite element model of human complex knee joint using multimodality CT and MRI images.In this study, we developed a finite element model of the knee joint for total knee arthroplasty (TKA) using matched and fused CT and MRI data, hoping to provide a useful tool for the simulation study of knee joint biomechanics of TKA.Methods The CT and MRI image data about an intact knee of a 26-year-old male volunteer were imported into the Mimics software for the establishment of 3D models of bony and soft-tissue structures.A complete knee model was developed following the registration and fusion of the constructed 3D models based on the external landmarks.After the simulated implantation of TKA components, a finite element model of the TKA knee was constructed with the Hypermesh software.Then the finite element model was analyzed following the definition of its material behavior, boundary conditions and loading.Results The finite element model of the TKA knee, which was composed of bones, ligaments, components, polyethylene insert and bone cement, was developed from CT-MRI image registration and fusion and maintained its important spatial relationship among different structures in the TKA knee.The results obtained from the finite element analysis showed the characteristics of stress distribution in the TKA knee.Conclusion The finite element model of the knee joint for TKA can be established by matching and fusing CT and MRI image data, which can be employed as a useful tool for the study of knee joint biomechanics of TKA.

Objective To evaluate the accuracy of ultrasound-measured inferior vena cava (IVC) diameter in assessment of the preoperative blood volume in elderly patients.Methods Sixty patients,aged 60-75 yr,with body mass index 20-25 kg/m2,of ASA physical status Ⅰ-Ⅲ,scheduled for elective transurethral resection of prostate,were randomly divided into 3 groups (n =20 each):control group (group C),lactated Ringer's solution group (group RL),and hydroxyethyl starch group (group H).Lactated Ringer's solution 8 ml/kg was infused intravenously in group RL.Hydroxyethyl starch 130/0.4 8 ml/kg was infused intravenously in group H.SpO2,mean arterial pressure (MAP),HR and central venous pressure (CVP) were monitored before and after fluid therapy.The IVC diameters,both during expiration (IVCe) and inspiration (IVCi),were measured using ultrasound.IVC collapsibility index (IVC-CI) was calculated.Results The IVCeand IVCi were significantly increased,and IVC-CI was decreased after fluid therapy as compared with those before fluid therapy in RL and H groups.Compared with group C,the IVCe and IVCi were significantly increased,and IVC-CI was decreased after fluid therapy in RL and H groups.IVCe and IVCi were positively correlatedwith CVP (r=0.746 and 0.697,respectively).IVC-CI was negatively correlated with CVP (r =-0.547).Conclusion Ultrasoundmeasured IVC diameter provides better accuracy in assessing the preoperative blood volume in elderly patients.

Objective UPLC-MS/MS bio-analysis method was developed for the simultaneous determination ofberberine,naringin,hesperidin,and neohesperidin in plasma of rats.Methods UPLC Acquity BEH C18 (50 rmm × 2.1 mm,1.7 μm) column was used,mobile phases were containing 0.05％ formic acid and 2 mmol/L ammonium formate in water (A)-containing 0.05％ formic acid in acetonitrile (B) as the mobile phase gradient elution;SD rats were randomly divided into oral administration berberine group,Citrus aurantium extract group,and berberine and C.aurantium extract compatibility group.Results UPLC-MS/MS method could be applied to determination of berberine,naringin,hesperidin,and neohesperidin,method validation meets the requirements of biological sample analysis.When rats were administered with berberine and C.aurantium extract compatibility,the plasma concentration of berberine was much more than single dose of berberine group and the bioavailability of berberine was increased.Meanwhile,naringin and neohesperidin can be detected in rat's plasma.Conclusion The bioavailability of flavonoids is significantly improved as well compared to the single dose of C.aurantium extract.This suggests that berberine and C.aurantium extract compatibility has significant drug-drug interaction.

BACKGROUND: Preoperative diagnosis and differential diagnosis of small solid pulmonary nodules are very difficult. Computed tomography (CT), as a common method for lung cancer screening, is widely used in clinical practice. The aim of this study was to analyze the clinical data of patients with malignant pulmonary nodules and intrapulmonary lymph nodes in the clinical diagnosis and treatment of <1 cm solid pulmonary nodules, so as to provide reference for the differentiation of the two. METHODS: Patients with solid pulmonary nodules who underwent surgery from June 2017 to June 2020 were analyzed retrospectively. The clinical data of 145 nodules (lung adenocarcinoma 60, lung carcinoid 2, malignant mesothelioma 1, sarcomatoid carcinoma 1, lymph node 81) were collected and finally divided into two groups: lung adenocarcinoma and intrapulmonary lymph nodes, and their clinical data were statistically analyzed. According to the results of univariate analysis (χ² test, t test), the variables with statistical differences were selected and included in Logistic regression multivariate analysis. The predictive variables were determined and the receiver operating characteristic (ROC) curve was drawn to get the area under the curve (AUC) value of the area under the curve. RESULTS: Logistic regression analysis showed that the longest diameter, Max CT value, lobulation sign and spiculation sign were important indicators for distinguishing lung adenocarcinoma from intrapulmonary lymph nodes, and the risk ratios were 106.645 (95%CI: 3.828-2,971.220, P<0.01), 0.980 (95%CI: 0.969-0.991, P<0.01), 3.550 (95%CI: 1.299-9.701, P=0.01), 3.618 (95%CI: 1.288-10.163, P=0.02). According to the results of Logistic regression analysis, the prediction model is determined, the ROC curve is drawn, and the AUC value under the curve is calculated to be 0.877 (95%CI: 0.821-0.933, P<0.01). CONCLUSIONS For <1 cm solid pulmonary nodules, among many factors, the longest diameter, Max CT value, lobulation sign and spiculation sign are more important in distinguishing malignant pulmonary nodules from intrapulmonary lymph nodes.

OBJECTIVE: To study the effect of dexmedetomidine (Dex) on cognitive dysfunction induced by tibial fracture in rats. METHODS: Sixteen male SD rats were randomized into control group and tibial fracture group, and the behavior indicators were measured on days 1, 3, 5 and 7 after tibial fracture and the expressions of CX3L1 protein and mRNA in the hippocampus were detected. Another 24 male SD rats were randomly divided into control group, tibial fracture group, and tibia fracture with CX3CL1 antibody group, and the behavior indicators and hippocampal CX3L1 protein expression were evaluated after corresponding treatments. In another experiment, we randomized 24 male SD rats into control group, tibial fracture group and tibial fracture with Dex treatment, and tested their hippocampal CX3L1 protein and mRNA expressions as well as the behavior indicators after the treatments. RESULTS: Compared with the control rats, the rats with tibial fracture spent significantly less time in the novel arm on days 1, 3, 5 and 7 after the fracture ( < 0.05) with obviously lowered expressions of CX3L1 protein and mRNA in the hippocampus ( < 0.05). In the rats with tibial fracture, treatment with CX3CL1 antibody further decreased the time spent in the novel arm ( < 0.05) and the expression level of CX3L1 protein in the hippocampus ( < 0.05); In contrast, treatment with Dex significantly increased the time spent time in the novel arm ( < 0.05) and enhanced the hippocampal expressions of CX3L1 protein and mRNA in rats with tibial fractures ( < 0.05). CONCLUSIONS Dex can alleviate cognitive dysfunction induced by tibial fracture in rats by increasing the expression of CX3CL1 in the hippocampus.
Animals ; Cognitive Dysfunction ; Dexmedetomidine ; Hippocampus ; Male ; Rats ; Rats, Sprague-Dawley ; Tibial Fractures

BACKGROUND: With the extensive development of minimally invasive surgery for pulmonary nodules, preoperative localization becomes more and more critical. There are some defects in traditional localization methods, so it is necessary to improve. The aim of this study was to compare and analyze the safety and effectiveness of two new methods, namely four-hook needle and memory alloy coil, in the localization of pulmonary nodules. METHODS: A retrospective analysis of 152 patients was performed. 76 cases were in four-hook needle group, and 76 cases were in memory alloy coil group. Pulmonary nodules were located before operation, and then video-assisted wedge resection was performed. The average procedure time, localization complications and nodule resection time were counted. RESULTS: The target pulmonary nodules were successfully removed in both groups. In four-hook needle group, 76 patients found localization devices, all the pulmonary nodules were successfully removed, and one case was transferred to open the chest for wedge resection of pulmonary nodules due to severe thoracic adhesion. All 76 patients in memory alloy coil group were successfully resected with pulmonary nodules, and one patient underwent compromising enlarged resection because no lesion was found after the specimen was removed during the operation. There was no significant difference in the incidence of pneumothorax and pulmonary hemorrhage, the success rate of localization and nodule wedge resection time between the two groups. The average time of localization in four-hook needle group was (13.66±3.11) min, lower than that of memory alloy coil group (15.51±3.65) min, and the difference was statistically significant (P=0.001). In memory alloy coil group, when the distance from the nodule to the pleura was ≥1.5 cm and <1.5 cm, the average localization time was (17.20±4.46) min and (14.91±3.15) min, respectively, and there was a statistical difference between the two distance (P=0.044). CONCLUSIONS Four-hook needle and memory alloy coil have good safety and effectiveness, and the localization time of four-hook needle is shorter. When using memory alloy coil, the effect of the method is better for pulmonary nodules with a distance less than 1.5 cm to pleura.
Alloys ; Humans ; Lung Neoplasms/surgery* ; Multiple Pulmonary Nodules ; Retrospective Studies ; Thoracic Surgery, Video-Assisted ; Tomography, X-Ray Computed