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Numerical Study of the Biomechanical Behavior of a 3D Printed Polymer Esophageal Stent in the Esophagus by BP Neural Network Algorithm 被引量:1
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作者 Guilin Wu Shenghua Huang +7 位作者 Tingting Liu Zhuoni Yang Yuesong Wu Guihong Wei Peng Yu Qilin Zhang Jun Feng Bo Zeng 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2709-2725,共17页
Esophageal disease is a common disorder of the digestive system that can severely affect the quality of life andprognosis of patients. Esophageal stenting is an effective treatment that has been widely used in clinica... Esophageal disease is a common disorder of the digestive system that can severely affect the quality of life andprognosis of patients. Esophageal stenting is an effective treatment that has been widely used in clinical practice.However, esophageal stents of different types and parameters have varying adaptability and effectiveness forpatients, and they need to be individually selected according to the patient’s specific situation. The purposeof this study was to provide a reference for clinical doctors to choose suitable esophageal stents. We used 3Dprinting technology to fabricate esophageal stents with different ratios of thermoplastic polyurethane (TPU)/(Poly-ε-caprolactone) PCL polymer, and established an artificial neural network model that could predict the radial forceof esophageal stents based on the content of TPU, PCL and print parameter. We selected three optimal ratios formechanical performance tests and evaluated the biomechanical effects of different ratios of stents on esophagealimplantation, swallowing, and stent migration processes through finite element numerical simulation and in vitrosimulation tests. The results showed that different ratios of polymer stents had different mechanical properties,affecting the effectiveness of stent expansion treatment and the possibility of postoperative complications of stentimplantation. 展开更多
关键词 Finite element method 3D printing polymer esophageal stent artificial neural network
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Stent,drug,polymer——enefits,risks,and opportunities
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作者 Samuel J.Shubrooks 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2006年第2期71-72,共2页
  It has been well established that use of drug-eluting stents has resulted in marked reduction in neointimal proliferation following stenting and that this is reflected clinically in a very significant decrease in ...   It has been well established that use of drug-eluting stents has resulted in marked reduction in neointimal proliferation following stenting and that this is reflected clinically in a very significant decrease in late lumen loss, instent restenosis, and target lesion revascularization. This benefit occurs, however, in the setting of delayed endothelial and vascular wall healing with its potential for continuing thrombogenicity requiring more prolonged use of dual antiplatelet therapy to prevent stent thrombosis.…… 展开更多
关键词 enefits risks and opportunities stent drug polymer
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Research on the Microstructure Construction Technology of Fully Degraded Polymer Vascular Stent Based on Electric Field Driven 3D Printing
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作者 Yanpu Chao Fulai Cao +3 位作者 Hao Yi Shuai Lu Yaohui Li Hui Cen 《Fluid Dynamics & Materials Processing》 EI 2024年第11期2489-2508,共20页
The so-called fourth-generation biodegradable vascular stent has become a research hotspot in thefield of bioengineering because of its good degradation ability and drug-loading characteristics.However,the preparation... The so-called fourth-generation biodegradable vascular stent has become a research hotspot in thefield of bioengineering because of its good degradation ability and drug-loading characteristics.However,the preparationof polymer-degraded vascular stents is affected by known problem such as poor processflexibility,low formingaccuracy,large diameter wall thickness,limited complex pore structure,weak mechanical properties of radial support and high process cost.In this study,a deposition technique based on a high-voltage electric-field-driven continuous rotating jet is proposed to fabricate fully degraded polymer vascular stents.The experimental results showthat,due to the rotation of the deposition axis,the deposition direction of PCL(polycaprolactone)micro-jet isalways tangent to the surface of the deposition axis.The direction of the viscous drag force is also consistent withthe deposition direction of the jet.It is shown that by setting different rotation speeds of deposition axisωandlinear motion speeds of the nozzle V,the direction of rotation,pitch and angle of the individual printed spiralcurve can be precisely tuned.In the process of multiple spiral curves matching the deposition forming thin walltube mesh,the mesh shape and size of the thin wall tube can be accurately controlled by changing the number ofmatching spiral curves and the size of the matching position bias distance.Finally,the characteristics of a PCLtubular stent sample(with uniform-size microfibers and mesh shape),fabricated under the appropriate processparameters are described in detail. 展开更多
关键词 Electricfield driven micro-jet spiral curve polymer vascular stent
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用冠状动脉造影探讨无聚合物微孔紫杉醇药物洗脱支架置入后近期和远期随访结果 被引量:2
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作者 周旭晨 李田昌 +7 位作者 梁滨 黄荣翀 张波 尹达 王少鹏 王俊杰 朱皓 张妍 《中国循环杂志》 CSCD 北大核心 2010年第5期329-331,共3页
目的:前瞻性、非随机探索性研究,用定量冠状动脉(冠脉)造影方法(QCA),评价无聚合物微孔紫杉醇洗脱支架(YINYITMDES)置入冠脉原发(denovo)病变的近期、远期有效性和安全性。方法:2005-03至2005-09月大连医科大学附属第一医院和北京同仁... 目的:前瞻性、非随机探索性研究,用定量冠状动脉(冠脉)造影方法(QCA),评价无聚合物微孔紫杉醇洗脱支架(YINYITMDES)置入冠脉原发(denovo)病变的近期、远期有效性和安全性。方法:2005-03至2005-09月大连医科大学附属第一医院和北京同仁医院的冠心病患者69例,年龄30~70岁,其中男性49例(71.0%),女性20例(29.0%),经冠脉造影(CAG)证实至少一支冠脉狭窄(冠脉原发病变,直径狭窄≥70%),靶病变长度≤26mm,靶血管直径2.5~3.5mm,按照常规方法行冠脉造影并置入YINYITMDES。结果:69例患者共放置79个支架。支架平均直径为(3.21±0.45)mm,置入支架长度平均为(18.29±6.09)mm。69例患者临床平均随访(11±2)个月,随访率100%。其中对45例患者(放置53个支架)在支架置入后9~13个月进行了冠脉造影随访,随访率65.2%。与术前相比,术后即刻最小内腔直径(MLD)明显改善,术前为(0.45±0.27)mm,支架术后为(3.21±0.45)mm,术后9~13个月与术后即刻相比,支架内再狭窄程度为(10.59±12.45)%,最小内腔直径(2.87±0.41)mm,支架内晚期管腔丢失(0.34±0.11)mm;支架内再狭窄率5.7%。结论:无聚合物微孔紫杉醇载药YINYITM对冠脉原发病变有较好的近期和远期治疗作用。 展开更多
关键词 无聚合物微孔紫杉醇涂层支架 冠状动脉介入治疗 再狭窄
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考虑尺寸效应的聚合物血管支架力学性能 被引量:2
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作者 李红霞 谭忠 +1 位作者 王锡旸 史伟良 《医用生物力学》 CAS CSCD 北大核心 2023年第5期946-952,共7页
目的研究考虑尺寸效应的聚合物血管支架力学性能,分析支架结构对支架力学性能和支架变形过程中尺寸效应的影响规律,为支架的结构设计提供理论依据。方法建立考虑尺寸效应的聚乳酸的Cosserat理论模型,并结合有限元法,通过三点弯曲和平板... 目的研究考虑尺寸效应的聚合物血管支架力学性能,分析支架结构对支架力学性能和支架变形过程中尺寸效应的影响规律,为支架的结构设计提供理论依据。方法建立考虑尺寸效应的聚乳酸的Cosserat理论模型,并结合有限元法,通过三点弯曲和平板压获得支架抗弯刚度和径向刚度,进一步分析支架筋厚和筋宽、支撑单元曲率半径和轴向间距对支架径向支撑性能和尺寸效应的影响规律。结果聚合物血管支架在弯曲和压缩过程中均存在明显的尺寸效应现象;支架径向刚度与支撑单元曲率半径和轴向间距均呈负相关,与筋厚和筋宽均呈正相关;支撑单元曲率半径、轴向间距以及支架筋厚和筋宽越小,聚合物血管支架压缩过程中的尺寸效应越大。结论支架的径向支撑性能主要由结构的刚度决定,并受支架变形过程中尺寸效应的影响;支架几何结构的特征尺寸越小、支架弯扭变形的程度越大,则尺寸效应越明显,对支架径向支撑性能的增幅越大。 展开更多
关键词 可降解聚合血管支架 尺寸效应 COSSERAT理论 三点弯曲 平板压
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Six-month angiographic and one-year clinical outcomes of polymer free paclitaxel-eluting stent in patients with ST-segment elevation myocardial infarction: a comparison with permanent polymer sirolimus-eluting stent 被引量:4
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作者 DANG Qun LI Yong-jian +2 位作者 GAO Lu JIN Zhe GOU Li-xin 《Chinese Medical Journal》 SCIE CAS CSCD 2012年第19期3393-3397,共5页
Background Since permanent polymer is implicated in adverse events associated with delayed vessel healing after drug eluting stents (DES) implantation, great efforts have been made to develop more biocompatible DES ... Background Since permanent polymer is implicated in adverse events associated with delayed vessel healing after drug eluting stents (DES) implantation, great efforts have been made to develop more biocompatible DES with biodegradable polymer or without polymer. The present study aimed to evaluate the safety and efficacy of polymer free paclitaxel-eluting stents (PF-PES) in comparison with permanent polymer sirolimus-eluting stents (PP-SES) in patients with acute ST-segment elevation myocardial infarction (STEMI). Methods Patients with STEMI were randomly assigned to receive PP-SES (n=55), and PF-PES (n=50). The 6-month angiographic and 1-year clinical outcomes were compared between the two groups. Target lesion failure (TLF) was defined as the composite of cardiac death, recurrent nonfatal myocardial infarction (Re-MI), or target lesion revascularization (TLR). Results Follow-up angiography at six months was performed in 72.7% of the PP-SES group and 70.0% of the PF-PES group (P=0.757). The two groups had comparable angiographic outcomes including minimal luminal diameter, diameter stenosis, late loss and binary restenosis. All patients were clinically followed up to one year. The two groups had similar clinical outcomes with relatively low rates of target lesion failure (10.9% PP-SES vs. 12.0% PF-PES, P=0.861) and definite or probable stent thrombosis (1.8% PP-SES vs. 2.0% PF-PES, P=1.000) at one year. Conclusions The present study suggests that the safety and efficacy of PF-PES in the setting of STEMI are comparable to PP-SES. Further randomized trials with laraer study DODUlations are needed to net definite conclusions. 展开更多
关键词 polymer free paclitaxel-eluting stent permanent polymer sirolimus-eluting stent acute ST-segment elevation myocardial infarction stent thrombosis
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等离子体聚合聚环氧乙烷类涂层用于提高镁合金心血管支架抗腐蚀性能 被引量:3
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作者 余东海 熊开琴 黄楠 《材料导报》 EI CAS CSCD 北大核心 2020年第6期166-171,共6页
本研究以二乙二醇二甲醚(Diglyme)为单体,通过等离子体聚合技术得到均匀、无孔的聚环氧乙烷类(PEO-Like)涂层,并用来提高MgZnMn合金的抗腐蚀性能。在两种放电功率下制得了不同结构的涂层。X射线光电子能谱(XPS)和傅里叶变换衰减全反射... 本研究以二乙二醇二甲醚(Diglyme)为单体,通过等离子体聚合技术得到均匀、无孔的聚环氧乙烷类(PEO-Like)涂层,并用来提高MgZnMn合金的抗腐蚀性能。在两种放电功率下制得了不同结构的涂层。X射线光电子能谱(XPS)和傅里叶变换衰减全反射红外光谱(ATR-FTIR)显示,高功率下制备的涂层(HPEO)比低功率下制备的涂层(LPEO)分子结构交联度更高。电化学与体外浸泡测试证明两种涂层均具有良好的防腐蚀效果,但HPEO保护效果更佳。经过球囊扩张试验后,HPEO在MgZnMn支架上仍粘附良好,并且在后续的PBS浸泡实验中,涂层依旧能显著降低支架的降解速率。 展开更多
关键词 等离子体聚合 镁合金 降解 心血管支架 聚环氧乙烷类
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Five-year outcomes of biodegradable versus second-generation durable polymer drug-eluting stents used in complex percutaneous coronary intervention 被引量:1
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作者 Na Xu Lin Jiang +10 位作者 Yi Yao Jingjing Xu Ru Liu Huanhuan Wang Ying Song Lijian Gao Zhan Gao Xueyan Zhao Bo Xu Yaling Han Jinqing Yuan 《Chinese Medical Journal》 SCIE CAS CSCD 2023年第3期322-330,共9页
Background:There are few data comparing clinical outcomes of complex percutaneous coronary intervention(CPCI)when using biodegradable polymer drug-eluting stents(BP-DES)or second-generation durable polymer drug-elutin... Background:There are few data comparing clinical outcomes of complex percutaneous coronary intervention(CPCI)when using biodegradable polymer drug-eluting stents(BP-DES)or second-generation durable polymer drug-eluting stents(DP-DES).The purpose of this study was to investigate the safety and efficacy of BP-DES and compare that with DP-DES in patients with and without CPCI during a 5-year follow-up.Methods:Patients who exclusively underwent BP-DES or DP-DES implantation in 2013 at Fuwai Hospital were consecutively enrolled and stratified into two categories based on CPCI presence or absence.CPCI included at least one of the following features:unprotected left main lesion,≥2 lesions treated,≥2 stents implanted,total stent length>40 mm,moderate-to-severe calcified lesion,chronic total occlusion,or bifurcated target lesion.The primary endpoint was major adverse cardiac events(MACE)including all-cause death,recurrent myocardial infarction,and total coronary revascularization(target lesion revascularization,target vessel revascularization[TVR],and non-TVR)during the 5-year follow-up.The secondary endpoint was total coronary revascularization.Results:Among the 7712 patients included,4882(63.3%)underwent CPCI.Compared with non-CPCI patients,CPCI patients had higher 2-and 5-year incidences of MACE and total coronary revascularization.Following multivariable adjustment including stent type,CPCI was an independent predictor of MACE(adjusted hazard ratio[aHR]:1.151;95%confidence interval[CI]:1.017–1.303,P=0.026)and total coronary revascularization(aHR:1.199;95%CI:1.037–1.388,P=0.014)at 5 years.The results were consistent at the 2-year endpoints.In patients with CPCI,BP-DES use was associated with significantly higher MACE rates at 5 years(aHR:1.256;95%CI:1.078–1.462,P=0.003)and total coronary revascularization(aHR:1.257;95%CI:1.052–1.502,P=0.012)compared with that of DP-DES,but there was a similar risk at 2 years.However,BP-DES had comparable safety and efficacy profiles including MACE and total coronary revascularization compared with DP-DES in patients with non-CPCI at 2 and 5 years.Conclusions:Patients underwent CPCI remained at a higher risk of mid-to long-term adverse events regardless of the stent type.The effect of BP-DES compared with DP-DES on outcomes was similar in CPCI and non-CPCI patients at 2 years but had inconsistent effects at the 5-year clinical endpoints. 展开更多
关键词 Complex percutaneous coronary intervention Durable polymer drug-eluting stents Biodegradable polymer drug-eluting stents
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3D Printing of Biodegradable Polymer Vascular Stents:A Review 被引量:1
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作者 Weijian Hua Weiliang Shi +4 位作者 Kellen Mitchell Lily Raymond Ryan Coulter Danyang Zhao Yifei Jin 《Chinese Journal of Mechanical Engineering(Additive Manufacturing Frontiers)》 2022年第2期1-15,共15页
Biodegradable polymer vascular stents(BPVSs)have been widely used in percutaneous coronary interventions for the treatment of coronary artery diseases.The development of BPVSs is an integrated process that combines ma... Biodegradable polymer vascular stents(BPVSs)have been widely used in percutaneous coronary interventions for the treatment of coronary artery diseases.The development of BPVSs is an integrated process that combines material design/selection,manufacturing,and performance characterization.Three-dimensional(3D)printing technology is a powerful tool for polymer stent fabrication.Current review studies have focused primarily on the material and structural design of polymer stents but have failed to comprehensively discuss different 3D printing approaches and stent characterization techniques.In this paper,we address these shortcomings by discussing 3D printing methods and their application in BPVSs.First,some commonly used 3D printing methods(including material extrusion,vat polymerization,and powder bed fusion)and potential 3D printing strategies(including material jetting and binder jetting)for fabricating BPVSs are discussed;furthermore,the main post-treatments are summarized.Then,techniques to characterize the morphology,mechanical properties,and biological prop-erties of the printed BPVSs are introduced.Subsequently,representative commercial BPVSs and lab-grade BPVSs are compared.Finally,based on the limitations of stent printing and characterization processes,future perspec-tives are proposed,which may help develop new techniques to fabricate more customized stents and accurately evaluate their performance. 展开更多
关键词 Biodegradable polymer vascular stents 3D printing approaches MORPHOLOGY Mechanical properties Biological properties Future perspectives
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多孔水凝胶的制备及性能研究
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作者 潘禧凯 张小娟 +4 位作者 肖文柯 赵媛 田耘小 周敏 钱飘 《科技创新导报》 2021年第15期33-35,共3页
由于支架存在钙化等问题,人工角膜植入后仍有很多并发症,因此目前研究重点是改善支架力学性能。本文采用无皂乳液聚合法制备了聚苯乙烯(PS)模板,并用模板法将丙烯酰胺(AM)前驱液填充到PS模板,制得PS/PAM复合水凝胶。通过二甲苯浸泡除去P... 由于支架存在钙化等问题,人工角膜植入后仍有很多并发症,因此目前研究重点是改善支架力学性能。本文采用无皂乳液聚合法制备了聚苯乙烯(PS)模板,并用模板法将丙烯酰胺(AM)前驱液填充到PS模板,制得PS/PAM复合水凝胶。通过二甲苯浸泡除去PS模板,制得多孔PAM水凝胶。采用傅里叶红外光谱仪(FTIR)、扫描电镜(SEM)和万能力学试验机分析多孔PAM水凝胶的官能团、形貌和机械性能。结果表明,PAM水凝胶具有多孔结构。与无孔PAM水凝胶相比,多孔PAM水凝胶的抗拉强度和断裂伸长率均有提高。 展开更多
关键词 人工角膜支架 无皂乳液聚合法 模板法 PS模板 聚丙烯酰胺 多孔水凝胶
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金属支架在慢性输尿管梗阻中的应用 被引量:2
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作者 刘伟 田跃军 +3 位作者 李谛音 庞阳阳 王羽含 王志平(审校) 《临床泌尿外科杂志》 2016年第11期1046-1049,共4页
由不同病因引起的慢性输尿管梗阻(CUO),金属支架(MS)植入可以作为另一种治疗方法的选择。较之传统聚合物支架,其换管周期长,性价比更高,可以用作长期引流,尤其适合治疗恶性肿瘤压迫引起的输尿管梗阻,或治疗复杂的、常规方法治疗有困难... 由不同病因引起的慢性输尿管梗阻(CUO),金属支架(MS)植入可以作为另一种治疗方法的选择。较之传统聚合物支架,其换管周期长,性价比更高,可以用作长期引流,尤其适合治疗恶性肿瘤压迫引起的输尿管梗阻,或治疗复杂的、常规方法治疗有困难的良性输尿管梗阻。术前仔细的病例筛选及术后密切随访,对预防和治疗MS植入的并发症是十分必要的。 展开更多
关键词 慢性输尿管梗阻 金属支架 聚合物支架
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三亚甲基碳酸酯-丙交酯-乙交酯三元共聚物的合成与性能表征 被引量:6
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作者 袁媛 董建廷 +1 位作者 李速明 范仲勇 《复旦学报(自然科学版)》 CAS CSCD 北大核心 2012年第4期493-500,共8页
以辛酸亚锡为催化剂,采用开环聚合制备了高分子量的三亚甲基碳酸酯-丙交酯二元共聚物(PTLA)和三亚甲基碳酸酯-丙交酯-乙交酯三元共聚物(PTLGA).所有聚合物样品的数均分子量均在105以上,分子量分布指数n介于1.4~1.9.通过合成方法的控制... 以辛酸亚锡为催化剂,采用开环聚合制备了高分子量的三亚甲基碳酸酯-丙交酯二元共聚物(PTLA)和三亚甲基碳酸酯-丙交酯-乙交酯三元共聚物(PTLGA).所有聚合物样品的数均分子量均在105以上,分子量分布指数n介于1.4~1.9.通过合成方法的控制,制备的PTLA和PTLGA具有无规序列结构.与PLLA和PTLA相比,GA单元的引入使得聚合物的结晶能力下降,PTLGA具有更低的熔点和结晶度.在力学性能测试中,三种聚合物材料的拉伸强度均高于47MPa.然而,PTLGA的拉伸断裂功为1.0×105 kJ·m-3,远高于PLLA与PTLA的断裂功(约2.0×104 kJ·m-3),表明PTLGA的拉伸韧性大幅提高.血小板粘附实验显示PTLGA对血小板的激活程度小,具有更好的血液相容性.因此PTLGA是一种新型生物可降解聚合物血管支架材料. 展开更多
关键词 丙交酯 三亚甲基碳酸酯 乙交酯 开环聚合 血管支架
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