|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Numerical Simulation of Fluid and Heat Transfer in a Biological Tissue Using an Immersed Boundary Method Mimicking the Exact Structure of the Microvascular Network显示文摘The aim of this study is to develop a model of fluid and heat transfer in a biological tissue taking into account the exact structure of the related microvascular network,and to analyze the influence of structural changes of such a network induced by diabetes.A cubic region representing local skin tissue is selected as the computational domain,which in turn includes two intravascular and extravascular sub-domains.To save computational resources,the capillary network is reduced to a 1D pipeline model and embedded into the extravascular region.On the basis of the immersed boundary method(IBM)strategy,fluid and heat fluxes across a capillary wall are distributed to the surrounding tissue nodes by a delta function.We consider both steady and periodic blood pressure conditions at the entrances of the capillary network.Under steady blood pressure conditions,both the interstitial fluid pressure and tissue temperature around the capillary network are larger than those in other places.When the periodic blood pressure condition is considered,tissue temperature tends to fluctuate with the same frequency of the forcing,but the related waveform displays a smaller amplitude and a certain time(phase)delay.When the connectivity of capillary network is diminished,the capacity of blood redistribution through the capillary network becomes weaker and a subset of the vessel branches lose blood flow,which further aggravates the amplitude attenuation and time delay of the skin temperature fluctuation. | Yuanliang Tang Lizhong Mu Ying He | 2020 | Fluid Dynamics & Materials Processing2020，16，2： | 3 |
| 2 | Influence of Clip Locations on Intraaneurysmal Flow Dynamics in Patient-specific Anterior Communicating Aneurysm Models with Different Aneurysmal Angle显示文摘To improve aneurysm treatment,this study examined the influence of clip locations on hemodynamic factors in patient-specific anterior communicating artery(ACoA)aneurysms with different aneurysmal angle.We proposed a simplified classification of ACoA aneurysms using aneurysmal angle,defined by the angle of pivot of the aneurysmal dome and the virtual two-dimensional plane created by both proximal A2 segments of anterior cerebral artery(ACA).ACoA aneurysms with three different aneurysmal angles,which are 15°,80°and 120°,were analyzed in our study.In this work,we obtained hemodynamics before and after clipping surgery with three clip locations based on clinical clipping strategies in three ACoA aneurysms with different aneurysm angles.Results showed that local high pressure occurs at impingement region of the ACoA aneurysm before clipping and new impingement region close to the clipping location after clipping treatment.For clipping the aneurysm with aneurysmal angle 15°and a wide neck,wall shear stress(WSS)distribution is more uniform when the clipping angle of two clips close to 180°comparing with other two angles.In addition,for clipping the aneurysm with aneurysmal angle 80°and 120°,local high pressure appears on new impingement region and high WSS distributes around the clipping location when the clip plane is normal to the direction of inflow of aneurysm from the dominance of A1 segment of ACA.Hence,we should avoid the impingement of inflow from the A1 segment and choose a favorable clipping location for the fastness of clip.The results of our study could preoperatively give a useful information to the decision of surgical plan. | Lizhong Mu Qingzhuo Chi Changjin Ji Ying He Ge Gao | 2018 | Computer Modeling in Engineering & Sciences2018，，8： | 1 |
| 3 | Haemodynamic Analysis of the Relationship between the Morphological Alterations of the Ascending Aorta and the Type A Aortic-Dissection Disease显示文摘Type A aortic dissection(AD)is one of the most serious cardiovascular diseases,whose risk predictors are controversial.The purpose of this research was to investigate how elongation accompanied by dilation of the ascending aorta(AAo)affects the relevant haemodynamic characteristics using image-based computational models.Five elongated AAos with different levels of dilation have been reconstructed based on the centerlines data of an elderly and an AD patient.Numerical simulations have been performed assuming an inflow waveform and a Windkessel model with three elements for all outflow boundaries.The numerical results have revealed that the elongation of AAo can disturb the systolic helical flow pattern between the root of AAo and the aortic arch.The helical flow inside the AAo starts to develop into a vortex flow when the elongated AAo becomes dilated.The vortex gives rise to a localized oscillatory shear index at the ostia of the brachiocephalic artery(BA)and the inner curve of the aortic arch.This study suggests that abnormal growth of AAo,especially accompanied by its moderate dilation,can be considered as morphological risk factors of AD. | Qingzhuo Chi Huimin Chen Lizhong Mu Ying He Yong Luan | 2021 | Fluid Dynamics & Materials Processing2021，17，4： | 1 |
| 4 | In-vitro experimental study on the fluid-structure interaction in an image-based flexible model with a lateral cerebral aneurysm显示文摘Aiming to experimentally investigate the effect of aspect ratio(AR)of image-based aneurysm on wall deformation oscillation under different pulsatile flow conditions with considering the fluid-structure interaction.In this study,three silicon aneurysm models with different AR(0.8,1.0,and 1.2)were constructed.It was found that the detected wall deformation oscillation of patient-specific aneurysm increased with pulsatile inflow frequency increases,which was greater and more obvious oscillation than that in the ideal lateral aneurysm.In addition,the maximum amplitude of wall deformations oscillation of the aneurysm at the dome during the systolic phase decrease and the oscillation of wall deformation become obvious as AR increases.These results could provide more knowledge about the effect of AR and pulsatile flow on the wall deformation of aneurysm and will be helpful for understanding the aneurysm rupture risk. | Qingzhuo Chi Xinyu Li Sheng Chang Lizhong Mu Ying He Ge Gao | 2019 | Medicine in Novel Technology and Devices2019，，3： | 0 |
| 5 | Effects of size and location of distal tear on hemodynamics and wave propagation in type B aortic dissection显示文摘The type B aortic dissection(TBAD)is a perilous disease with high morbidity and mortality rates.The hemodynamics of TBAD in different scenarios has been widely studied by computational fluid dynamics(CFD)research.However,the flow pattern and wave propagation characteristics in the cardiovascular system with TBAD are not yet clear,and the effect of the distal tear is still unknown.In this work,a onedimensional(1D)cardiovascular system model coupling with a zero-dimensional(0D)lumped-parameter model is introduced to study the hemodynamics and wave propagation in the cardiovascular system.The results show that the proposed 0D-1D method well captures the oscillation and retrograde characteristics for the flow in the false lumen(FL),and the smaller distal tear damps the retrograde flow.Besides,the distal tear should also be paid attention to,and the wave intensity(WI)can be used as an access mark of the degree of the aortic dissection(AD). | Huimin CHEN Qingzhuo CHI Ying HE Lizhong MU Yong LUAN | 2022 | Applied Mathematics and Mechanics(English Edition)2022，43，9： | 0 |
| 6 | Study of Effect of Boundary Conditions on Patient-Specific Aortic Hemodynamics显示文摘Cardiovascular computational fluid dynamics(CFD)based on patient-specific modeling is increasingly used to predict changes in hemodynamic parameters before or after surgery/interventional treatment for aortic dissection(AD).This study investigated the effects of flow boundary conditions(BCs)on patient-specific aortic hemodynamics.We compared the changes in hemodynamic parameters in a type A dissection model and normal aortic model under different BCs:inflow from the auxiliary and truncated structures at aortic valve,pressure control and Windkessel model outflow conditions,and steady and unsteady inflow conditions.The auxiliary entrance remarkably enhanced the physiological authenticity of numerical simulations of flow in the ascending aortic cavity.Thus,the auxiliary entrance can well reproduce the injection flow fromthe aortic valve.In addition,simulations of the aortic model reconstructed with an auxiliary inflow structure and pressure control and the Windkessel model outflow conditions exhibited highly similar flow patterns and wall shear stress distribution in the ascending aorta under steady and unsteady inflow conditions.Therefore,the inflow structure at the valve plays a crucial role in the hemodynamics of the aorta.Under limited time and calculation cost,the steady-state study with an auxiliary inflow valve can reasonably reflect the blood flow state in the ascending aorta and aortic arch.With reasonable BC settings,cardiovascular CFD based on patient-specific ADmodels can aid physicians in noninvasive and rapid diagnosis. | Qingzhuo Chi Huimin Chen Shiqi Yang Lizhong Mu Changjin Ji Ying He Yong Luan | 2022 | Computer Modeling in Engineering & Sciences2022，，4： | 0 |
| 7 | Thermogram-based estimation of foot arterial blood flow using neural networks显示文摘The altered blood flow in the foot is an important indicator of early diabetic foot complications.However,it is challenging to measure the blood flow at the whole foot scale.This study presents an approach for estimating the foot arterial blood flow using the temperature distribution and an artificial neural network.To quantify the relationship between the blood flow and the temperature distribution,a bioheat transfer model of a voxel-meshed foot tissue with discrete blood vessels is established based on the computed tomography(CT)sequential images and the anatomical information of the vascular structure.In our model,the heat transfer from blood vessels and tissue and the inter-domain heat exchange between them are considered thoroughly,and the computed temperatures are consistent with the experimental results.Analytical data are then used to train a neural network to determine the foot arterial blood flow.The trained network is able to estimate the objective blood flow for various degrees of stenosis in multiple blood vessels with an accuracy rate of more than 90%.Compared with the Pennes bioheat transfer equation,this model fully describes intra-and inter-domain heat transfer in blood vessels and tissue,closely approximating physiological conditions.By introducing a vascular component to an inverse model,the blood flow itself,rather than blood perfusion,can be estimated,directly informing vascular health. | Yueping WANG Lizhong MU Ying HE | 2023 | Applied Mathematics and Mechanics(English Edition)2023，44，2： | 0 |
| 8 | Safety and immunogenicity of inactivated SARS-CoV-2 vaccine in high-risk occupational population:a randomized,parallel,controlled clinical trial显示文摘Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the resulting coronavirus disease 2019 (COVID-19) have a substantial burden on health-care systems around the world. This is a randomized parallel controlled trial for assessment of the immunogenicity and safety of an inactivated SARS-CoV-2 vaccine, aiming to determine an appropriate vaccination interval of the vaccine for high-risk occupational population.Methods: In an ongoing randomized, parallel, controlled phase IV trial between January and May 2021 in Taiyuan City, Shanxi Province, China, we randomly assigned the airport ground staff and public security officers aged 18 to 59 years to receive two doses of inactivated SARS-CoV-2 vaccine at 14 days, 21 days, or 28 days. The serum neutralizing antibody to live SARS-CoV-2 was performed at baseline and 28 days after immunization. Long-term data are being collected. The primary immunogenicity endpoints were neutralization antibody seroconversion and geometric mean titer (GMT) at 28 days after the second dose. Analysis of variance (ANOVA), chi-square, and logistic regression analysis were used for data analysis.Results: A total of 809 participants underwent randomization and received two doses of injections: 270, 270, 269 in the 0-14, 0-21, and 0-28 vaccination group, respectively. By day 28 after the second injection, SARS-CoV-2 neutralizing antibody of GMT was 98.4 (95%CI: 88.4-108.4) in the 0-14 group, which was significantly lower compared with 134.4 (95%CI: 123.1-145.7) in the 0-21 group (P < 0.001 vs 0-14 group) and 145.5 (95%CI: 131.3-159.6) in the 0-28 group (P < 0.001 vs 0-14 group), resulting in the seroconversion rates to neutralizing antibodies (GMT ≥ 16) of 100.0% for all three groups, respectively. The intention-to-treat (ITT) analysis yielded similar results. All reported adverse reactions were mild.Conclusions: Both a two-dose of inactivated SARS-CoV-2 vaccine at 0-21 days and 0-28 days regimens significantly improved SARS-CoV-2 neutralizing antibody level compared to the 0-14 days regimen in high-risk occupational population, with seroconversion rates of 100.0%. | Yongliang Feng Jing Chen Tian Yao Yue Chang Xiaoqing Li Rongqin Xing Hong Li Ruixue Xie Xiaohong Zhang Zhiyun Wei Shengcai Mu Ling Liu Lizhong Feng Suping Wang | 2021 | Infectious Diseases of Poverty2021，10，6： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员