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Site-Dependent Osseointegration of Biodegradable High-Purity Magnesium for Orthopedic Implants in Femoral Shaft and Femoral Condyle of New Zealand Rabbits

Cheng Pengfei , Zhao Changli , Han Pei , Ni Jiahua , Zhang Shaoxiang , Zhang Xiaonong , Chai Yimin

材料科学技术(英) doi:10.1016/j.jmst.2016.03.012

Magnesium (Mg) has been widely accepted as osteoconductive biomaterial, but osseointegration of Mg device at different implantation sites is still unclear. In the present study, high-purity magnesium (HP Mg) pins were implanted into femoral shaft and condyle of New Zealand rabbits concurrently. 2, 8, 12 and 16 weeks after surgery, rabbit femurs were harvested for micro-computed tomography (micro-CT) scanning and subsequent histological examinations. HP Mg pins were retrieved for scanning electron microscope and energy dispersive spectrum (SEM/EDS) analyses. HP Mg pins at both implantation sites performed stable corrosion with mineral deposition and bone incorporation on surface. However, difference in distribution of contact osteogenesis centers and biological properties of peri-implant bone tissues was detected between femoral shaft and femoral condyle. In femoral condyle, contact osteogenesis centers originated from both periosteum and cancellous bones and the whole HP Mg pin was encapsuled in trabecular bone at 16 weeks. Meanwhile, bone volume to total bone volume (BV/TV) and bone mineral density (BMD) of peri-implant bone tissues were above those of normal bone tissues. In femoral shaft, contact osteogenesis centers were only from periosteum and direct bone contact was confined in cortical bone, while BV/TV and BMD kept lower than normal. Furthermore, new formation of peri-implant bone tissues was more active in femoral condyle than in femoral shaft at 16 weeks. Therefore, although HP Mg performed good biocompatibility and corrosion behavior in vivo, its bioadaption of osseointegration at different implantations sites should be taken into consideration. Bone metaphysic was suitable for Mg devices where peri-implant bone tissues regenerated rapidly and the biological properties were close to normal bone tissues.

关键词: Osseointegration , High-purity magnesium , Site-dependent , Femoral shaft and condyle , Bioadaption

HAN液晶盒中开关时间对形变场弛豫过程的影响

李晓吉 , 郑桂丽 , 张志东

液晶与显示 doi:10.3788/YJYXS20132801.0025

HAN液晶盒撤掉外加电压的过程(即弛豫过程)中,假定电压的开关时间为有限的,把电压处理为时间的指数衰减函数.在这一假定下,对撤掉外加电压后HAN液晶盒中指向矢的分布情况进行研究,得到了对HAN液晶盒的弛豫过程有影响的电压开关时间的范围.

关键词: HAN液晶盒 , 有限开关时间 , 驰豫过程 , 动力学理论

PEI复合润滑膜的制备与摩擦性能

廖晨棵 , 赵文轸 , 张春婉 , 李磊

复合材料学报 doi:10.3321/j.issn:1000-3851.2008.03.006

用不同溶剂通过两步法制备MoS2填充芳香和半脂肪聚醚酰亚胺(PEI)复合膜,采用乙酸酐和三氟乙酸酐(TFAA)封端.利用IR Prestige-21红外光谱仪表征纯PEI亚胺化程度;采用SDT Q600测试纯PEI的热转变与热稳定性能;用M-200型环块摩擦试验机考察干摩条件下分子柔顺性、封端剂、填料比例对PEI润滑膜摩擦因数一时间(μ-t)曲线的影响,以及载荷、填料比例对稳定服役阶段μ平均值(μ)的影响;采用扫描电镜观察磨损表面形貌,分析磨损机制.结果表明,半脂肪族PEI分子设计在不明显降低热稳定性能的前提下,显著降低了聚合物的Tg.PEI润滑膜的μ值随着摩擦时间的增加先上升后下降,但波动时间较短,μ随后逐渐升高直至润滑失效.柔性结构、三氟乙酸酐封端和适当的填料比有利于改善摩擦性能,填充70 wt%MoS2的氟化酸酐封端PEI-2具有最低为0.027的(μ)值.PEI润滑膜的(μ)值还与载荷、MoS2填料比有关.

关键词: 聚醚酰亚胺 , 脂肪族PI , 摩擦磨损 , 润滑膜 , MoS2

PVA/PEI复合纳滤膜的制备及性能优化

侯影飞 , 王金凤 , 刘敏

膜科学与技术 doi:10.16159/j.cnki.issn1007-8924.2016.06.009

用聚砜超滤膜为底膜,以聚乙烯亚胺(PEI)为阳离子添加剂,与聚乙烯醇(PVA)共混制备带正电复合纳滤膜.讨论了制膜条件对膜性能的影响,并用红外光谱、扫描电镜、接触角对膜的化学组成、表面形态和疏水性进行表征.结果表明,随着PEI含量的增加,纳滤膜对二价盐溶液的截留率先增加后减小,最佳制膜条件为:PVA和PEI的质量分数均为2%,PVA与PEI质量比为PVA∶PEI=8∶1,戊二醛的质量分数为2%,硫酸的质量分数为1%;热处理温度为70℃.此时复合纳滤膜对2 g/L MgSO4溶液的截留率为94.52%,通量为5.91 L/(m2·h).复合纳滤膜对4种盐截留率大小顺序为:MgSO4>MgCl2>Na2 SO4>NaCl.添加PEI后的膜表面电位变大,分离性能增加,亲水性变好,通量增大.

关键词: 聚乙烯亚胺 , 聚乙烯醇 , 纳滤膜

电场诱导纳米结构HAN液晶盒中新型有序重构过程的描述

陈思博 , 王永超 , 周璇 , 张志东

液晶与显示 doi:10.3788/YJYXS20163109.0853

基于 Landau-de Gennes 理论,利用松弛迭代的方法,研究了包含-1/2向错线的混合排列(HAN)液晶盒中,平行于向错线的电场所诱导的结构转变。结果表明,盒厚固定时,电场诱导五种结构转变过程;电场固定时,盒厚变化产生三类结构转变方式。力曲线上的极小值确定了液晶系统发生结构转变的临界盒厚。

关键词: 有序重构 , Landau-de Gennes理论 , -1/2 向错 , 力曲线

复合型吸附材料PEI/SiO2对胆红素的吸附作用

雷海波 , 高保娇 , 申艳玲

应用化学 doi:10.3969/j.issn.1000-0518.2007.05.020

通过γ-氯丙基三甲氧基硅烷的偶联,将聚乙烯亚胺(PEI)偶合接枝在硅胶微粒表面,制得了对胆红素具有强吸附性能且可经酸碱处理重复使用的复合型吸附材料.结果表明,PEI大分子链中大量质子化的胺基氮原子与胆红素分子中电离的羧基之间产生的静电相互作用使PEI/SiO2对胆红素有吸附作用.考察了介质pH值、离子强度及PEI在复合材料PEI/SiO2的键合量对胆红素吸附容量的影响.静态吸附实验结果表明,硅胶表面的PEI对胆红素具有强的吸附能力,等温吸附满足Freundlich吸附方程,当胆红素初始质量浓度为0.590 g/L时,平衡吸附量可达13.17 mg/g;在近中性(pH=6)溶液中,复合吸附材料PEI/SiO2对胆红素吸附能力最强;在酸性溶液中,由于胆红素的羧基电离度较小,PEI/SiO2对胆红素的作用力较弱;在碱性溶液中,虽然胆红素的羧基电离度较大,但由于PEI的胺基氮原子质子化程度变小,PEI/SiO2与胆红素之间的作用力较弱.由于静电屏蔽作用,离子强度在很大程度上影响PEI/SiO2对胆红素的吸附容量.

关键词: 胆红素 , 吸附材料 , 聚乙烯亚胺 , 静电相互作用 , 吸附作用

PEEKK/PEI共混物的相容性和力学性能

WEI Yong-Hui , 陈彪

应用化学 doi:10.3969/j.issn.1000-0518.2008.08.023

在380℃下熔融挤出制得聚醚醚酮酮(PEEKK)与聚醚酰亚胺(PEI)共混物.采用差示扫描量热仪(DSC)、广角X射线衍射仪(WAXD)和万能力学试验机研究了共混物的相容性、结晶行为和力学性能.结果表明,PEEKK/PEI共混体系为相容体系.其Tg组成的关系符合Fox方程.随共混体系中PEI用量的增加,共混物的冷结晶温度从208℃升至280℃.熔体降温结晶温度从315℃降至260℃,熔融温度从363℃降至322℃,熔融焓在-31.5~-2.2 J/g之间变化.共混物基本保持了PEEKK的力学性能,断裂伸长率随着PEI用量的增加从25%增加到60%,说明PEI对PEEKK有增韧作用.

关键词: 聚醚醚酮酮(PEEKK) , 聚醚酰亚胺(PEI) , 相容性 , 共混物 , 力学性能

Comparison Study of Corrosion Behavior and Biocompatibility of Polyethyleneimine (PEI)/Heparin and Chitosan/Heparin Coatings on NiTi alloy

Ping Dong

材料科学技术(英)

Biomedical molecule has received extensive application in surface modification coating. In this paper, polyethyleneimine (PEI)/heparin coating and chitosan/heparin coating on NiTi alloy substrates were prepared by layer-by-layer method, and differences of corrosion behavior and biocompatibility of the coatings were studied. Static contact angles and Fourier transform infrared (FT-IR) test were used to analysis the surface morphology and structure character of the materials, and atomic absorption spectrum was used to verify the corrosion behavior of the materials. Furthermore, hemolysis, dynamic clotting time and platelet binding test were utilized to investigate the biocompatibility of the materials. The results revealed that the blood compatibility of PEI/heparin coating is better than that of the chitosan/heparin coating as well as the substrate.

关键词: Biocompatibility , null , null , null , null

PEI 用于磁性纳米颗粒载药及联合载药抗肿瘤的研究进展?

吴慎剑 , 刘源岗 , 王士斌

材料导报 doi:10.11896/j.issn.1005-023X.2015.013.016

聚乙烯亚胺(PEI)作为一种阳离子聚合物在药物负载中受到了广泛的关注。PEI 具有载药高效、易于修饰粒子和生物相容性好等特点,成为了研究热点。综述了目前 PEI 的研究现状,介绍了 PEI 修饰磁性纳米颗粒的制备方法,并对其载药治疗癌症的相关进展进行了讨论,重点阐述了 PEI 在联合载药抗肿瘤方面的应用,最后指出了PEI 在肿瘤治疗过程中仍需解决的问题和未来发展趋势。

关键词: 聚乙烯亚胺 , 药物负载 , 肿瘤治疗 , 联合载药

PEG/PEI复合膜渗透汽化汽油脱硫研究(Ⅰ)制膜条件影响

陈剑 , 李继定 , 亓荣彬 , 叶宏 , 陈翠仙

膜科学与技术 doi:10.3969/j.issn.1007-8924.2009.04.007

PEI超滤膜为支撑层,PEG为复合层,制备了PEG/PEI渗透汽化RCC汽油脱硫复合膜.通过傅立叶红外光谱仪对PEG/PEI复合膜表面进行了结构分析,考察了交联前后官能团的变化.通过扫描电子显微镜分析了复合膜表面和断面的形态.将制备的复合膜应用于正庚烷和噻吩体系,首先考察了膜的溶胀性和稳定性.研究了不同聚合物PEG浓度、交联剂浓度,交联温度和交联时间对分离性能的影响,从而得到最佳制膜条件.

关键词: 渗透汽化 , 汽油脱硫 , PEG/PEI复合膜 , 正庚烷/噻吩

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