Objective To investigate the impact of eccentric placement for various types of artificial aortic valves on downstream flow dynamics.Methods A physiological pulsatile circulation simulation system was employed and particle image velocimetry(PIV)was utilized to analyze the downstream flow field variations for bioprosthetic and mechanical valves under two placement conditions:centralized placement(0 mm)and eccentric placement(1 mm).Hemodynamic parameters such as velocity,vorticity,and viscous shear stress were assessed to evaluate the flow field characteristics.Results By analyzing the flow field variations at four characteristic time points,namely,early systole,acceleration phase,peak systole,and deceleration phase,a significant difference in flow field distribution between bioprosthetic and mechanical valves was observed.The bioprosthetic valve exhibited a centrally symmetric jet with a higher flow velocity,whereas the mechanical valve displayed a three-jet structure with a lower central flow velocity.Under eccentric placement,the blood flow in the aortic sinus region was sluggish,with a reduction in average velocity,hindering the formation and maintenance of vortices.During the peak systolic phase,the maximum viscous shear stresses in the sinus region for the bioprosthetic and mechanical valves were 0.45 and 0.67 Pa,respectively,approaching the threshold for endothelial cell damage.Conclusions Eccentric placement of both mechanical and bioprosthetic valves resulted in reduced sinus blood flow velocity and diminished viscous shear stress,creating favorable conditions for thrombus formation.In clinical practice,careful attention should be given to the placement of valve replacement to prevent eccentric placement.

Objective To explore the impact of different moving patterns during the dip-coating process on thickness distributions of polymer heart valves.Methods Based on the volume of fluid(VOF)multiphase flow model,the Eulerian wall-film(EWF)model,and dynamic mesh technology,the dip-coating manufacturing process of polymer heart valves were numerically simulated.The effects of vertical,horizontal,and circular moving patterns on flow characteristics of the surface impregnation liquid and liquid film distributions under self-rotation conditions of the models were mainly studied.Subsequently,seven identical test points were set on each valve leaflet to collect thickness data,and the coefficient of variation(CV)was calculated to evaluate the uniformity of the liquid film thickness.Given that the vertical and horizontal patterns had fewer moving planes,limiting the optimization space,the circular pattern(45°)with richer moving planes was selected as the basis for optimization,and comparative analysis of numerical simulation was conducted.Results In the vertical pattern,the peak CV was 0.461 3;in the horizontal pattern,the CV was 0.060 8;and in the circular pattern,the CV at 30°,45° and 60° were 0.457 5,0.272 8,and 0.255 6,respectively.After optimization,the CV for the circular pattern(45°)decreased to 0.052 5,representing an 80.7％reduction compared to the pre-optimization value.Conclusions The moving patterns significantly affect the uniformity of dip-coating thickness distributions.The horizontal pattern demonstrates the best uniformity,while the vertical pattern shows the poorest uniformity.The CV for the circular pattern decreases as the angle increases,with its uniformity between that of the vertical and horizontal patterns.Optimization of moving pattern parameters based on simulation results has improved the uniformity of thickness distributions.

Objective To explore the impact of different moving patterns during the dip-coating process on thickness distributions of polymer heart valves.Methods Based on the volume of fluid(VOF)multiphase flow model,the Eulerian wall-film(EWF)model,and dynamic mesh technology,the dip-coating manufacturing process of polymer heart valves were numerically simulated.The effects of vertical,horizontal,and circular moving patterns on flow characteristics of the surface impregnation liquid and liquid film distributions under self-rotation conditions of the models were mainly studied.Subsequently,seven identical test points were set on each valve leaflet to collect thickness data,and the coefficient of variation(CV)was calculated to evaluate the uniformity of the liquid film thickness.Given that the vertical and horizontal patterns had fewer moving planes,limiting the optimization space,the circular pattern(45°)with richer moving planes was selected as the basis for optimization,and comparative analysis of numerical simulation was conducted.Results In the vertical pattern,the peak CV was 0.461 3;in the horizontal pattern,the CV was 0.060 8;and in the circular pattern,the CV at 30°,45° and 60° were 0.457 5,0.272 8,and 0.255 6,respectively.After optimization,the CV for the circular pattern(45°)decreased to 0.052 5,representing an 80.7％reduction compared to the pre-optimization value.Conclusions The moving patterns significantly affect the uniformity of dip-coating thickness distributions.The horizontal pattern demonstrates the best uniformity,while the vertical pattern shows the poorest uniformity.The CV for the circular pattern decreases as the angle increases,with its uniformity between that of the vertical and horizontal patterns.Optimization of moving pattern parameters based on simulation results has improved the uniformity of thickness distributions.

Objective To investigate the impact of eccentric placement for various types of artificial aortic valves on downstream flow dynamics.Methods A physiological pulsatile circulation simulation system was employed and particle image velocimetry(PIV)was utilized to analyze the downstream flow field variations for bioprosthetic and mechanical valves under two placement conditions:centralized placement(0 mm)and eccentric placement(1 mm).Hemodynamic parameters such as velocity,vorticity,and viscous shear stress were assessed to evaluate the flow field characteristics.Results By analyzing the flow field variations at four characteristic time points,namely,early systole,acceleration phase,peak systole,and deceleration phase,a significant difference in flow field distribution between bioprosthetic and mechanical valves was observed.The bioprosthetic valve exhibited a centrally symmetric jet with a higher flow velocity,whereas the mechanical valve displayed a three-jet structure with a lower central flow velocity.Under eccentric placement,the blood flow in the aortic sinus region was sluggish,with a reduction in average velocity,hindering the formation and maintenance of vortices.During the peak systolic phase,the maximum viscous shear stresses in the sinus region for the bioprosthetic and mechanical valves were 0.45 and 0.67 Pa,respectively,approaching the threshold for endothelial cell damage.Conclusions Eccentric placement of both mechanical and bioprosthetic valves resulted in reduced sinus blood flow velocity and diminished viscous shear stress,creating favorable conditions for thrombus formation.In clinical practice,careful attention should be given to the placement of valve replacement to prevent eccentric placement.

BACKGROUND:In clinical practice,Cibotium barometz and Epimedium have shown significant efficacy in the treatment of rheumatoid arthritis,but the complex active ingredients contained in the two have an unclear mechanism of action at the molecular level for the treatment of rheumatoid arthritis. OBJECTIVE:Based on network pharmacology and molecular docking technology,to establish a collagen-induced arthritis model and to verify the potential targets and pathways of Cibotium barometz and Epimedium in the treatment of rheumatoid arthritis,providing reliable experimental evidence for the use of clinical formulas with Cibotium barometz and Epimedium as the main components. METHODS:Utilizing traditional Chinese medicine research platforms,traditional Chinese medicine encyclopedias,and databases of traditional Chinese medicine and chemical components from the Shanghai Institute of Organic,effective ingredients were retrieved and identified.3D molecular formulas were obtained from the PubChem platform and target predictions were made using PharmMapper and SwissTargetPrediction.Disease targets for rheumatoid arthritis were obtained from gene databases such as DrugBank,GeneCards,and OMIM.The intersections of targets and Cibotium barometz and Epimedium were plotted using VENNY 2.1 after calibration with the Uniport database.A protein-protein interaction network graph was constructed using the STRING platform.Gene Ontology function analysis and Kyoto Encyclopedia of Genes and Genomes enrichment analysis were performed using the Metascape platform for data visualization.A four-layered network model of traditional Chinese medicine,ingredients,targets,diseases,and pathways was constructed using Cytoscape 3.9.0.The main effective ingredients were docked with core targets using AutoDock-Vina software to explore the best binding targets.A type II collagen+adjuvant-induced arthritis rat model was established,and the effects of Cibotium barometz and Epimedium on relevant pathway targets and inflammatory cell factors were observed after 21 days of intervention. RESULTS AND CONCLUSION:A total of 28 active ingredients from Cibotium barometz and Epimedium were selected,yielding 288 intersection targets for rheumatoid arthritis.The main ingredients included isobavachalcone,cibotium,and epimedium.The main targets included protein kinase 1 for serine/threonine(AKT1),tumor necrosis factor,and vascular endothelial growth factor A.Gene ontology analysis yielded 2 232 biological processes,mainly related to serine protein phosphorylation,positive regulation of serine/threonine protein kinase,and reactive oxygen metabolism.Kyoto Encyclopedia of Genes and Genomes enrichment analysis yielded 202 pathways,mainly involving the PI3K/AKT signaling pathway and epidermal growth factor receptor signaling pathway,which may exert therapeutic effects by regulating synovial cell apoptosis and proliferation and suppressing inflammatory factors.Molecular docking results showed the strongest binding activity and stable structure of Cibotium barometz and Epimedium with AKT1 and estrogen receptor transcription factor 1,which was closely related to apoptosis and proliferation and inflammatory signaling pathways such as PI3K/AKT.Cibotium barometz and Epimedium reduced the expression of interleukin-1β,interleukin-6,and tumor necrosis factor-α in the serum of collagen-induced arthritis rat models.Cibotium barometz and Epimedium reduced the expression of p-PI3K,p-AKT,and p-FOXO1 in the synovium of collagen-induced arthritis rat models.The results indicate that the combination of Cibotium barometz and Epimedium may exert therapeutic effects by inhibiting the proliferation of synovial cells and suppressing the expression of inflammatory factors via the PI3K/AKT/FOXO1 signaling pathway.This may be closely related to the occurrence of inflammation and bone destruction in rheumatoid arthritis,and provides a reference for the rational use and development of new drugs in clinical practice.

Objective:To analyze the risk factors and prognosis of endoleak after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm.Methods:The clinical data of patients with infrarenal abdominal aortic aneurysms treated by endovascular repair at the Department of Vascular Surgery,the First Affiliated Hospital of Guangxi Medical University from Jun 2012 to Nov 2021 were retrospectively analyzed.Results:During the first follow-up CTA after surgery,136 out of 299 patients had endoleak.A total of 186 patients had at least one CTA reexamination after discharge. Statistical analysis showed that excessive neck angulation was an independent risk factor for type Ⅰa endoleak ( t=-6.108, P<0.001), wider common iliac artery diameter (left Z=-2.787, P=0.005, Right Z=-2.381, P=0.017) and iliac aneurysm ( χ2=6.398, P=0.011) were risk factors for type Ⅰb endoleak. The survival time of patients in endoleak group was similar to no endoleak group. Conclusions:Excessive neck angulation is an independent risk factor for type Ⅰa endoleak. Most leaks resolve spontaneously ,the prognosis is fair.

Objective:To explore the effects of micro class combined with modular teaching on experimental teaching of internal medicine and basic nursing.Methods:Four classes of nursing students of Batch 2016 were selected as the research objects by drawing lots, and 148 nursing undergraduates were randomly divided into two groups. The combined teaching group adopted micro class combined with modular teaching, and the modular teaching group adopted modular teaching method. The examination scores, SDLRS (self-directed learning readiness scale for nursing education) scores, medical education environment and teaching satisfaction of the two groups were compared. SPSS 22.0 was conducted for chi-square test and t test. Results:The scores of internal medicine nursing, basic nursing and operation skills in the combined teaching group were significantly higher than those in the traditional teaching group ( P<0.05); at the end of the semester, the scores of self-management, love of learning, self-control and SDLRS total score of the combined teaching group were higher than those of the modular teaching group ( P<0.05); the scores of learning perception, teacher perception, environment perception and total score of the combined teaching group were higher than those of the modular teaching group ( P<0.05); the teaching satisfactions with improving learning interest, learning efficiency, learning initiative and mastering key contents better in the combined teaching group were higher than those in the modular teaching group ( P<0.05). Conclusion:The combination of micro class and modular teaching can improve the examination results and self-directed learning readiness of nursing students, improve the internal environment of medical education, and students' teaching satisfaction is high.

Objective:To determine the equilibrium solubility and n-octanol/water partition coefficients (Papp)of cinnamon acid and cinnamaldehyde. Methods:The equilibrium solubility of cinnamon acid and cinnamaldehyde in different solutions was determined by HPLC,and their n-octanol/water partition coefficients were determined by a shaking flask method combined with HPLC-DAD. Results:When the pH of solution was 7.8,the equilibrium solubility of cinnamon acid was the largest,while that of cinnamaldehyde was the largest in pH 6.8 solution. The scopes of lgPappof cinnamon acid and cinnamaldehyde in different buffer solutions(pH 1.2-7.8) were -1.04-2.27 and 0.29-1.67, respectively, while those in n-octanol/water solvent were 0.85 and 1.26, respectively. Conclusion:The method is simple,accurate and fast to predicate the absorption of chemical components. In gastrointestinal physiological environment,cinnamaldehyde has good absorption, while cinnamon acid is with poor absorption in stomach and with better absorption in intestinal.

Objective To evaluate the treatment results and psychological changes in female patients with stress urinary incontinence (SUI) before and after TVT-O.Methods Fifty-six female patients with SUI underwent TVT-O from Nov.2011 to Mar.2012.Preoperative and postoperative International Consultation on Incontinence Questionnaire Short Form (ICIQ-SF) score,Incontinence Quality of Life Questionnaire (I-QOL) score,one hour urine pad test,Self-rating Anxiety Scale (SAS) score,and Self-rating Depression Scale (SDS) score were recorded and analyzed.Results Followed up for 3 months,the subjective satisfactory rate was 94.6％ (53/56),the objective efficiency rate was 91.1％ (51/56),and there was no recurrence in this group.Before operation and 3-month after operation,ICIQ-SF scores were 15.9±3.2(13-20) and 8.6±2.7 (4-13),t=6.02,P=0.01 ; I-QOL scores were 40.3±18.9 (33-62) and 87.6±11.2(76-102),t=6.81,P=0.01; The urine leakages in one hour urine pad test were 26.7±7.1 (9-51)g and 5.2±2.5 (1-8)g,t=7.13,P=0.00; SAS scores were 59.3±8.3 (48-72) and 42.6±4.6 (39-52),t=9.15,P =0.01; SDS scores were 57.2±5.6 (49-69) and 40.2±3.4 (36-54),t=8.63,P=0.01,respectively.No serious and long-term complication occurred.Conclusions TVT-O is a safe and effective treatment option for female SUI.This treatment can improve the quality of life and psychological status of the patients.

10.3969/j.issn.2095-4344.2013.25.020