1.Effects of Moving Pattern on Dipping Thickness Distributions in Polymer Heart Valve
Haiyang WEI ; Zheng LI ; Qianwen HOU ; Yana MENG ; Liangwei ZHU ; Enhui HAN ; Jianjun HU ; Jianye ZHOU
Journal of Medical Biomechanics 2025;40(4):1012-1019
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.
2.Flow Field Characteristics of Aortic Valve with Eccentric Lower Valve Placement:A PIV Experimental Study
Enhui HAN ; Qianwen HOU ; Yang XIAO ; Yana MENG ; Haiyang WEI ; Yu JIANG ; Jianjun HU ; Jianye ZHOU
Journal of Medical Biomechanics 2025;40(1):25-33
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.
3.Development of a risk prediction score scale for late-onset sepsis in very low birth weight infants
Qianwen XIA ; Dan LI ; Lili YAO ; Yi GONG ; Mengfan QIU ; Fan WAN ; Yaoyao DONG ; Ruolin REN ; Yalan DOU ; Lin YUAN ; Xiaojing HU
Chinese Pediatric Emergency Medicine 2025;32(3):161-169
Objective:To analyze the predictive factors associated with late-onset sepsis(LOS) in very low birth weight infants,and to develop a risk prediction score scale applicable to these infants three days postnatal.This will provide valuable insights for early diagnosis and timely intervention.Methods:Very low birth weight infants admitted to the Children's Hospital of Fudan University from January 1,2022,to June 30,2024,were selected as research subjects.These infants were categorized into two groups:the LOS group and the non-LOS group,based on whether they developed LOS.LASSO regression analysis,alongside univariate and multivariate regression analyses,was employed to identify predictive factors for LOS in this population.A Logistic model was constructed using the optimal combination of predictive variables,and a risk assessment scale was subsequently developed.The prediction performance of the model was evaluated using the Hosmer-Lemeshow chi-square test and the receiver operating characteristic curve.Results:A total of 444 cases of very low birth weight infants were included,of which 185 had LOS and 259 did not.After screening the variables,seven independent factors were included into the model:birth weight,gestational age,tracheal intubation,abnormal skin color,abdominal distension,elevated C-reactive protein levels,and right hand perfusion index.A predictive scoring scale was developed based on the regression coefficients of each variable,with corresponding risk scores assigned as follows:1,4,3,2,1,1,and 2; a score of ≥3.5 indicated high-risk groups.The Hosmer-Lemeshow test results demonstrated that χ2 = 7.602( P = 0.473).The area under the receiver operating characteristic curve was 0.792 ( P<0.001),with a sensitivity of 73.5% and specificity of 71.0%. Conclusion:The risk score scale developed in this study exhibits significant predictive capability,providing valuable insights for clinical medical personnel to assess the risk of LOS in very low birth weight infants during the early postnatal period.
4.Effects of Moving Pattern on Dipping Thickness Distributions in Polymer Heart Valve
Haiyang WEI ; Zheng LI ; Qianwen HOU ; Yana MENG ; Liangwei ZHU ; Enhui HAN ; Jianjun HU ; Jianye ZHOU
Journal of Medical Biomechanics 2025;40(4):1012-1019
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.
5.Flow Field Characteristics of Aortic Valve with Eccentric Lower Valve Placement:A PIV Experimental Study
Enhui HAN ; Qianwen HOU ; Yang XIAO ; Yana MENG ; Haiyang WEI ; Yu JIANG ; Jianjun HU ; Jianye ZHOU
Journal of Medical Biomechanics 2025;40(1):25-33
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.
6.Development of a risk prediction score scale for late-onset sepsis in very low birth weight infants
Qianwen XIA ; Dan LI ; Lili YAO ; Yi GONG ; Mengfan QIU ; Fan WAN ; Yaoyao DONG ; Ruolin REN ; Yalan DOU ; Lin YUAN ; Xiaojing HU
Chinese Pediatric Emergency Medicine 2025;32(3):161-169
Objective:To analyze the predictive factors associated with late-onset sepsis(LOS) in very low birth weight infants,and to develop a risk prediction score scale applicable to these infants three days postnatal.This will provide valuable insights for early diagnosis and timely intervention.Methods:Very low birth weight infants admitted to the Children's Hospital of Fudan University from January 1,2022,to June 30,2024,were selected as research subjects.These infants were categorized into two groups:the LOS group and the non-LOS group,based on whether they developed LOS.LASSO regression analysis,alongside univariate and multivariate regression analyses,was employed to identify predictive factors for LOS in this population.A Logistic model was constructed using the optimal combination of predictive variables,and a risk assessment scale was subsequently developed.The prediction performance of the model was evaluated using the Hosmer-Lemeshow chi-square test and the receiver operating characteristic curve.Results:A total of 444 cases of very low birth weight infants were included,of which 185 had LOS and 259 did not.After screening the variables,seven independent factors were included into the model:birth weight,gestational age,tracheal intubation,abnormal skin color,abdominal distension,elevated C-reactive protein levels,and right hand perfusion index.A predictive scoring scale was developed based on the regression coefficients of each variable,with corresponding risk scores assigned as follows:1,4,3,2,1,1,and 2; a score of ≥3.5 indicated high-risk groups.The Hosmer-Lemeshow test results demonstrated that χ2 = 7.602( P = 0.473).The area under the receiver operating characteristic curve was 0.792 ( P<0.001),with a sensitivity of 73.5% and specificity of 71.0%. Conclusion:The risk score scale developed in this study exhibits significant predictive capability,providing valuable insights for clinical medical personnel to assess the risk of LOS in very low birth weight infants during the early postnatal period.
7.Impact of surgical approach on the efficacy and safety of patients with primary central nervous system lymphoma
Dai XIANGPING ; Xue LEI ; Xu QIANWEN ; Hu YAN ; Chen YUANLU ; Wang XINGBING
Chinese Journal of Clinical Oncology 2024;51(8):413-417
Objective:To investigate the effects of different surgical approaches on the efficacy and safety of patients with primary central nervous system lymphoma(PCNSL).Methods:The clinical data of 130 PCNSL patients admitted to The First Affiliated Hospital of University of Science and Tecnology of China between July 2012 and May 2023 were retrospectively analyzed.Patients were assigned into resection and biopsy groups according to the surgical approach.The safety and efficacy of the two groups were compared,including the objective re-sponse rate(ORR),overall survival(OS),and progression-free survival(PFS)after chemotherapy.Results:ORR and 2-year OS and PFS rates of the resection group were not significantly different from those of the biopsy group(ORR:63.2%vs.62.8%;2-year OS rate:68.6%vs.73.7%;2-year PFS rate:35.2%vs.40.7%,all P>0.05).The incidence of postoperative complications was significantly higher in the resection group than in the biopsy group(29.3%vs.11.4%,P=0.04).The difference in the length of hospitalization between the two groups was not statistic-ally significant.Treatment of the biopsy group was less expensive(P<0.01).Conclusions:In patients with PCNSL,biopsy and resection had comparable efficacy;however,the safety profile was better,and hospitalization was less costly in biopsy than in resection.
8.Clinical application progress of flow cytometry in diagnosis and therapeutic monitoring of patients with nonhematopoietic neoplasms
Qianwen HU ; Suwen YANG ; Sai QIAO ; Xinyou XIE ; Jun ZHANG
Chinese Journal of Laboratory Medicine 2024;47(7):722-728
Flow cytometry (FCM) is an interdisciplinary cell analysis technology that integrates optics, fluid dynamics, electronics, and computer science. While FCM is widely utilized in diagnosing and monitoring hematologic malignancies, its application in nonhematopoietic neoplasms (NHN) remains in its nascent stages. However, recent advancements in science and technology have led to the emergence of innovative FCM technologies, such as mass spectrometry flow cytometry (CyTOF) and spectral flow cytometry (SFC), offering promising avenues for their clinical application aiming to assist the clinical diagnosis of NHN patients. This review summarizes the features of fundamentals of traditional FCM, CyTOF, and SFC technologies, along with their applications and future prospective in NHN diagnosis and treatment, aiming to offer updated insights for the continued expansion and utilization of FCM technology in clinical laboratory settings.
9.Numerical Simulation of Biomechanics of Two Aortic Root Replacement Procedures with Valve Preservation
Qian WANG ; Xinjin LUO ; Juntao QIU ; Shengyi HU ; Xuechao DING ; Tianming DU ; Yanping ZHANG ; Qianwen HOU ; Aike QIAO
Journal of Medical Biomechanics 2024;39(4):691-698
Objective To elucidate the influence of two procedures aortic root remodeling using a straight tubular artificial vessel while preserving the aortic valve and the Florida sleeve procedure on the biomechanics of the aortic root.Methods Five finite element models of the aortic root were reconstructed using computed tomography angiography images,including two cases of aortic root remodeling(A1 and A2),two cases of the Florida sleeve procedure(B1 and B2),and one control group without aortic root pathology(C).Numerical simulations were performed to obtain the blood flow and pressure distribution result to assess the differences in the hemodynamics of the aortic root.Results There were no significant differences in the peak systolic velocity between the two procedures and the control.However,the flow velocity after aortic root remodeling was smoother,similar to the model of the control group,with a more stable average aortic pressure and wall shear stress.In the Florida sleeve procedure,high-speed blood flow affected the vessel wall,leading to various degrees of wall shear stress and pressure concentrations along the aortic wall.Conclusions After aortic root replacement with valve preservation,blood flow patterns in the reconstructed aortic root depended on postoperative changes in sinus geometry.Both surgical procedures showed favorable blood flow patterns;however,the flow pattern after aortic root remodeling was more stable than that after the Florida sleeve procedure.
10.Research progress on qualification certification of pediatric specialist nurses
Quan YUAN ; Kaiqi CHEN ; Qianwen ZENG ; Mengwan LIU ; Cuihuan HU
Chinese Journal of Modern Nursing 2024;30(19):2653-2657
This article reviews the concepts of specialist nurses and the current status of qualification certification for pediatric specialist nurses both domestically and internationally, and reflects on and looks forward to the certification system for pediatric specialist nurses in China, aiming to provide reference for the cultivation of pediatric specialist nurses.

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