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BACKGROUND:Three-point mechanics is an effective method for ankle foot orthosis correction and prevention of various foot diseases.At present,the clinical application research on 3D printing ankle foot orthosis has been widespread;however,there are relatively few reports on numerical simulation and finite element analysis involving three-point mechanical correction.There is a lack of relevant biomechanical experimental verification. OBJECTIVE:Three-point force was loaded to analyze the composite model of ankle foot orthosis and foot by finite element method,observing the effect of foot correction with ankle foot orthosis under three-point force intervention,verifying the effectiveness of three-point force and the reliability of ankle foot orthosis. METHODS:A three-dimensional foot and ankle model of a healthy volunteer was constructed based on the medical image processing software Mimics.Rodin 4D and Geomagic reverse engineering software were used to optimize the models and design personalized ankle foot orthosis models.Solidworks software was utilized to turn the ankle model inside for 10° to simulate the foot varus disease.Static loading was carried out on the foot force application area by ANSYS software combined with the three-point mechanics principle.The deformation and stress changes of the foot and ankle tissues were analyzed when the human foot pain threshold was met.The display dynamics was used to further verify the effectiveness of the three-point force applied by the ankle foot orthosis. RESULTS AND CONCLUSION:(1)The personalized ankle foot orthosis designed in this paper had the effect of preventing and fixing foot and ankle varus.The ankle varus was 1.81 mm after being loaded with 1 N·m of varus when not wearing ankle foot orthosis,while it was only 0.44 mm after wearing ankle foot orthosis,the deformation rate was reduced by 75.7%,and the effect of preventing varus was significantly enhanced.(2)When only coronal correction was performed,the low calcaneal force would aggravate the varus angle of the front foot.After adjusting the correction force on the inside of the heel and above the medial malleolus,the varus angle of the front foot and the calcaneus position were improved;however,the medial phalangeal region of the foot still had different degrees of adduction and displacement,which would aggravate the adduction deformity of the patient's front foot.(3)The correction effect of the coronal plane and horizontal plane was better than that of the single coronal plane.There was no adduction and displacement of the medial phalanges of the front foot and the varus angle of the front foot decreased under the force(25,10,10,20 N)of the medial heel,the medial shaft of the first metatarsal,below the lateral malleolus and above the medial malleolus,and the valgus along the X-axis was corrected by 1.395 mm,the calcaneus valgus was corrected by 1.227 mm.The calcaneus varus angle was corrected from 10.21° to 7.25°,and the varus angle was improved by 28.9%.(4)The lateral plantar metatarsal load decreased,the medial plantar metatarsal load increased under the action of a two-plane three-point force,and the plantar bone stress was significantly improved after correction.Thus,the reliability of the three-point force principle was further verified.This study provides an important theoretical support for the implementation of ankle foot orthosis in the treatment of varus in clinical practice.
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BACKGROUND@#Current replacement procedures for stenosis or occluded arteries using prosthetic grafts have serious limitations in clinical applications, particularly, endothelialization of the luminal surface is a long-standing unresolved problem.METHOD: We produced a cell-based hybrid vascular graft using a bioink engulfing adipose-derived mesenchymal stromal cells (ADSCs) and a 3D bioprinting process lining the ADSCs on the luminal surface of GORE-Tex grafts. The hybrid graft was implanted as an interposition conduit to replace a 3-cm-long segment of the infrarenal abdominal aorta in Rhesus monkeys. @*RESULTS@#Complete endothelium layer and smooth muscle layer were fully developed within 21 days post-implantation, along with normalized collagen deposition and crosslinking in the regenerated vasculature in all monkeys. The regenerated blood vessels showed normal functionality for the longest observation of more than 1650 days. The same procedure was also conducted in miniature pigs for the interposition replacement of a 10-cm-long right iliac artery and showed the same long-term effective and safe outcome. @*CONCLUSION@#This cell-based vascular graft is ready to undergo clinical trials for human patients.
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Objective:To optimize the dispatch of pre-hospital emergency resources and address the assessment challenge of ambulance demand, a pre-hospital emergency demand prediction model based on multi-model fusion was constructed.Methods:The retrospective study design method was adopted, and historical pre-hospital emergency dispatch records and corresponding weather data were extracted. Three types of primary learners were trained by 5-fold cross-validation, and the training results of the primary learners were fused by Stacking. The fusion results were input into the secondary learner as new features, and the final prediction results of ambulance demand were obtained by the secondary learner.Results:By comparison experiments, results showed that the multi-model fusion prediction model based on Stacking was superior to the single model in both mean absolute error and root mean square error, indicating that the model could predict ambulance demand more accurately.Conclusion:The pre-hospital emergency demand prediction model based on multi-model fusion could improve the accuracy and generalization ability of ambulance demand prediction by using historical emergency data and weather data, and provide strong support for the optimization of pre-hospital emergency resources.
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Objective:To investigate the correlation between TNFAIP3 gene polymorphism and osteoporotic fractures in the elderly and bone metabolism indexes.Methods:A total of 115 patients with senile osteoporotic fractures admitted to Peace Hospital Affiliated to Shanxi Changzhi Medical College from Jan. 2019 to Jun. 2021 were enrolled as the observation group, and 120 patients with senile osteoporotic fractures matched with gender, age and body mass index of the observation group were selected as the control group. The levels of blood calcium, blood phosphorus, alkaline phosphatase, 25-hydroxyvitamin D and other bone metabolism indexes of all subjects were recorded. The genotypes of rs10499194 and rs13207033 in TNFAIP3 gene were analyzed by capillary electrophoresis and fragment analysis (SNaPshot) . The mRNA relative expression level of TNFAIP3 gene in peripheral blood of all subjects was determined by quantitative real-time fluorescence quantitative polymerase chain reaction.Results:There were statistically significant differences in genotype distribution and gene frequency of RS10499194 and RS13207033 between the observation group and the control group ( P<0.05) . For rs10499194, CT genotype carriers had a significantly higher risk of fracture than wild-type CC genotype carriers [OR=3.253 (1.223-8.652) , P=0.014]. The dominant model was also statistically significant ( P=0.003) . For rs13207033, GA carriers had a significantly higher risk of fracture than wild-type GG carriers [OR=3.775 (1.192-11.952) , P= 0.016]. The dominant model was statistically significant ( P=0.009) . The blood calcium level in AA+GA group was significantly higher than that in GG group at rs13207033 site ( P=0.006) . The mRNA expression level of TNFAIP3 gene in the observation group was 1.41±0.09, which was significantly lower than that in the observation group (2.07±0.12, t=6.69, P<0.001) . TNFAIP3 mRNA expression level of rs10499194 site TT+CT group was 1.35±0.11, significantly lower than CC group 1.43±0.13 ( t=2.82, P=0.007) . Conclusion:The polymorphism of TN-FAIP3 gene is related to the occurrence of osteoporotic fractures and bone metabolism, and may affect the gene expression level.
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Objective To study urodynamic changes of urine at different degrees of hydronephrosis based on computational fluid dynamics (CFD) method, so as evaluate the influence of hydronephrosis degree on kidneys’ ability to discharge stones. Methods Twelve models, including the branched pelvis Model A (normal hydronephrosis A1, mild hydronephrosis A2, medium hydronephrosis A3, severe hydronephrosis A4 models), mature ampullary pelvis Model B (normal hydronephrosis B1, mild hydronephrosis B2, medium hydronephrosis B3, severe hydronephrosis B4 models), and embryo pot abdominal pelvis Model C (normal hydronephrosis C1, mild hydronephrosis C2, medium hydronephrosis C3, severe hydronephrosis C4 models) were established. The urine flow velocity and velocity vector at the neck of the kidney, the outlet of the renal pelvis were calculated by CFD method. Results As the degree of hydronephrosis increased, the flow velocity of urine at the neck of the kidney and the outlet of the renal pelvis decreased. The urinary shearing force of the stones and the kidney’s ability to discharge stones gradually decreased, whereas the circulatory stagnation zone and the velocity boundary layer in kidney aggregate system gradually increased. Conclusions Hydronephrosis can cause changes in urodynamics of the urine. Therefore, the effect of hydronephrosis with different degrees on the patient’s ability to discharge stones after surgery should be fully considered， so as to choose an appropriate treatment method for kidney stones in clinic.
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Objective To compare the efficacy and safety between minimally invasive plate osteosynthesis (MIPO) and open reduction and internal fixation (ORIF) in the treatment of humeral shaft fracture.Methods Case-control studies and randomized clinical trials comparing MIPO with ORIF in the treatment of humeral shaft fracture from January 2010 to June 2018 were retrieved from PubMed Library,Cochrane Library,Embase Library,China National Knowledge Internet and Wanfang Data.Methodological quality of the studies and trials was critically assessed.REVMANS.3 was used for data analysis.The 2 groups of patients were compared in terms of University of California,Los Angeles shoulder rating scale (UCLA),Mayo Elbow Performance Score (MEPS),union time,nonunion rate and complications.Results A total of 452 patients from 9 articles were included.There were 216 cases in the MIPO group and 236 ones in the ORIF group.The Meta analyses showed that the MIPO group had a significantly higher UCLA score (WMD =0.36,P=0.03),significantly lower incidences of complications (OR =-0.15,P ＜ 0.05) and iatrogenie radial nerve palsy (OR =0.24,P ＜ 0.05),and significantly shorter union time (SMD =-0.36,P =0.02) than the ORIF group.There were no significant differences between the 2 groups in MEPS (WMD =-0.48,P =0.43) or nonunion rate (OR =0.45,P =0.11).Conclusion MIPO may be a better choice for humeral shaft fracture than ORIF in regards to postoperative shoulder functions,union time,and incidences of complications and iatrogenic radial nerve palsy.
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Objective To investigate the effect of POSTN protein on the proliferation of chondrocytes of tibial plateau in old rats.Methods Cartilage cells collected from the tibial plateau of old rats were cultured in vitro to the third generation.Then the cells were divided into 3 groups:POSTN group,PBS group and POSTN antibody group.The proliferations of the three groups at 24 h,48 h and 72 h were determined by EDU method.The expression of Notch1 protein was detected by immunohistochemistry in all groups at the same time.Female 20-month-old Sprague-Dawley rats were randomly divided into 3 groups:POSTN protein injection group,Phosphate Buffered Saline (PBS) injection group and POSTN antibody injection group.Twelve weeks after the operation,related reagents were injected 3 times consecutively at day 1,day 3,day 5 and EDU was injected into joints at day 1.At 2 weeks after injection,the rats were killed and the knee tibial plateau was taken to observe the proliferation of the cartilage cells.Results At 24 h,there were differences between the three groups O(F=27.32,P=0.017).The proliferation rates of POSTN group [(23±8)％] and PBS group [(21±10)％] were higher than that of POSTN antibody group (16±5)(P=0.003,P=0.011).At 48 h,there were differences between the three groups (F=35.34,P＜0.01).The proliferation rate of POSTN group [(36±11)％] was higher than that of the other groups [(22±6)％],(18±6)％(P=0.021,P＜0.01).At 72h,there were differences between the three groups (F=52.62,P=0.000).The proliferation rate of POSTN group [(56±17)％] was the highest one,the proliferation rate of PBS group [(31±8)％] was the medium,and the POSTN antibody group [(26±7)％] was the lowest one (all P＜0.05).As for Notch1 protein expression in chondrocytes,there were differences between the three groups (F=26.72,P＜0.01).The Notch1 protein was the most frequently expressed in POSTN protein-injection group and the least in the anti-POSTN group.In rats,the proliferation rate of the chondrocytes in the medial tibia plateau of the knee of POSTN protein injection group [(36±14)％],which was the highest,and that of the POSTN antibody injection group [(10 ±4)％] was the lowest (all P＜0.05).Conclusion POSTN protein can promote the proliferation of chondrocytes knee OA rats.POSTN antibody injection has been shown to induce the proliferation of chondrocytes.The POSTN protein may promote the proliferation of chondrocytes by activating the Notch signaling pathway.
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A total of 1273 elders above 65 years old received health check-up in our community.Among them,63.3％ ( 806/1273 ) had a history of hypertension and 64.9％ ( 523/806 ) showed abnormal blood pressure.And 43.2％ (202/467) of those without a history of hypertension were firstly found to have abnormal blood pressure.Among 674 blood testers,19.6％ had an elevated level of fasting blood glucose.And 11.4％ of those without a history of diabetes had an elevated level of fasting blood glucose.Hyperuricemia (21.8％,n =147),hypercholesteremia ( 11.1％,n =75),hypertriglyceridemia (35.5％,n =239) and increased low density lipoprotein-cholesterol (LDL-C) (46.3％,n =312) were noted.The levels of total cholesterol and LDL-C were higher in females than those in males ( both P ＞ 0.05 ).The results suggested that general practitioners should pay more attention to the management of chronic diseases and the health education and screening of high-risk populations.
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[Objective]To evaluate the effect of bone cement oscillator on increasing bone cement-bone interface binding intensity.[Method]Sixty fresh femoral bones of adult pig were randomly divided into experiment group and control group under the 30%,50%,70% ultimate shear strengh of the cement/bone.There were 10 samples in each subgroup.Mechanics test was performed by MTS-810 material testing machine,and the binding intensity of bone cement-bone interface in oscillating cement-bone interface binding intensity in experiment group was compared with control group.[Result]Mechanics test showed bone cement group were significantly stronger than control group under the 30%,50% ultimate shear strengh of the cement-bone(P 0.05).[Conclusion]Bone cement oscillator can increase binding intensity of bone-cement interface,and effectively reduce long-term aseptic loosening of artificial prostheses.