Determination of antibacterial properties and cytocompatibility of silver-loaded coral hydroxyapatite

In this study, silver-loaded coral hydroxyapatites (SLCHAs) were used as scaffolds for bone tissue engineering. The SLCHAs were prepared by surface adsorption process and ion-exchange reaction between Ca²⁺ of coral hydroxyapatite (CHA) and Ag⁺ of silver nitrate with different concentrations at room temperature. The properties of the composite SLCHAs were investigated by inductively coupled plasma-atomic emission spectrometry (ICP-AES), scanning electron microscropy (SEM) equipped with backscattered electron detector (BSE), and energy-dispersive X-ray spectrometer (EDS). The SEM images showed that the morphology of the SLCHAs depended on the content of Ag⁺, and the silver ions were uniformly distributed on the surface of SLCHAs. The ICP-AES results demonstrated that the silver content of the SLCHAs decreased along with the decrease of the concentration of silver nitrate. The SLCHAs were found effective against Escherichia coli and Staphylococcus aureus by antibacterial test. Mouse embryonic pre-osteoblast cells (MC3T3-E1) were used to test the cytocompatibility of SLCHAs, CHA, and pure coral. Cell morphology and cell proliferation were studied with SEM, laser scanning confocal microscope (LSCM), and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay after 1, 3, and 5 days of culture. The results indicated the cell morphology and proliferation on the scaffolds of Ag⁺ (13.6 μg/ml)/CHA and Ag⁺ (1.7 μg/ml)/CHA were better than that on Ag⁺ (170 μg/ml)/CHA. In addition, adhesion of MC3T3-E1 on the scaffolds showed that the confluent cells showed fusiform shape and arranged tightly on the scaffolds. All the results showed that the antibacterial SLCHAs would have potential clinical application as the scaffolds for bone tissue engineering.     

含氟高分子生物材料的表面改性研究进展

含氟高分子材料因具有优异的稳定性和物理机械性能而成为目前研究和应用广泛的医用生物材料,但是,生物相容性的不足影响和限制了其作为体内长期植入材料的应用。因此,提高含氟高分子材料的生物相容性,尤其是通过表面改性的方法提高其生物相容性是一项有意义的研究课题。分别从改性手段和改性物质两方面综述了近年来国内外含氟高分子生物材料表面改性的研究发展。     

液氢温区下单温区双管道绝热支撑的热-结构耦合研究分析

以液氢温区下的单温区低温双管道为研究对象,对其进行了热流分析,建立了数学模型及几何模型,采用有限元方法进行了热-结构耦合分析求解,分析了不同壁厚下漏热、应力及形变的变化规律,和不同隔热孔径下的漏热、应力及形变的变化规律.研究结果表明:壁厚减小,漏热值减少,绝热支撑总体应力增加,支撑形变增大;相同壁厚下,隔热孔孔径增大,...     

Preparation,electronic structure and optical properties of CoxLaMg1−xAl11O19 microcrystals

Journal of Materials Science: Materials in Electronics - Co-doped LaMgAl11O19 microcrystals were synthesized by a facile sol–gel method. The as-synthesized microcrystals were near hexagonal...     

澳大利亚职业技术教育的核心与特色

介绍澳大利亚职业技术教育 (TechnicalandFurtherEducation ,简称TAFE)的核心与特色。     

基于商业综合体中复合需求的动线策略研究

本文首先探讨综合体模式下的商业混合趋势及其对设计的影响．并归纳多样商业形态组合的一些基本特点,在分析CCDI三个正在实施的工程实例的基础上,提出三种能够产生更多富于设计价值的空间的动线连接策略。     

基于PLC控制的组合磁力控制站测控系统的可靠性设计

本文重点从系统电源、微机测控、系统硬件及系统软件角度阐述基于PLC控制的HT6L1 4 0 0Z/ 114 0组合磁力控制站的可靠性设计。现场运行表明该磁力控制站性能稳定,运行可靠,具有广阔的应用前景     

Enhanced mechanical,thermal and dielectric properties of polyimide nanocomposites containing SiCp (SiCw) nanofillers for high energy-storage applications

Journal of Polymer Research - In this paper, we aimed to develop the nanocarrier based on poly (N-isopropyl acrylamide)—allyl acetoacetate grafted MoS2 nanosheets. The obtained polymer...     

磷化工"双废"联用工艺研究

以磷化工"双废"——磷石膏、磷尾矿为原料,通过硫酸循环酸浸磷尾矿,经盐酸分解磷尾矿、碳化磷石膏、转晶、酸化、析钙、析磷、浓缩、析镁等过程,得到了转化率为96.94％ 的CaCO 3,CaO质量分数为23.38％ 的二水石膏,MgO质量分数为8.27％、P2O5质量分数为23.89％、氮质量分数为6.83％ 的氮镁磷肥,氮质量分数为23.76％ 的氯化铵以及M g O质量分数为30.04％ 的碳酸镁等,所得产品均符合工业应用要求.讨论了循环酸浸过程中离子浓度的变化情况,为联合处理磷石膏、磷尾矿提供了新思路.     

溶胶-凝胶电泳WO_3膜的电致变色特性

采用溶胶-凝胶电泳法制备非晶态WO_8电致变色膜,经过适当条件热处理后,由于H~+(或/和Li~+)离子和电子的双注入,该膜能呈现无色至深蓝色的电致变色效应。其性能为:对应于响应时间t_(res)≈1S时,变色对比度C_R>2:1;开路存贮时间τ_(?)≈64h;变色循环寿命n≈8×10~4次。实验在C/二甲基亚砜+LiClO_4(液体电解质)/WO_8/ITO构成的可逆电池中进行。 讨论了热处理条件、试验电压、膜厚等对胶体膜结构、含水量、光密度变量、循环寿命、着色可逆性及保持特性的影响。