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《Composite Interfaces》2013,20(2-3):191-200
Biocompatibility in research and development of advanced prosthetics is a current problem faced by medical researchers. A major challenge in tissue engineering is to find materials and processing techniques that allow them to produce extracellular matrices (ECM) mimicking scaffolds that promote cell growth and organization into a specific architecture, inducing cell differentiation and subsequent cell function. The ideal tissue repair material thus should consist of synthetic biomaterials, such as natural polymers mimicking the mechanical and biological functionality of the ECM. Cellulose acetate membranes were used as scaffolds for microvascular cell growth. Hydroxyapatite (HA) is a natural ceramic (responsible for strength and stability in the human skeletal system) operable as a biocomposite coating to improve the biocompatibility of implant substrates. In this work, HA was prepared from low cost natural calcium source — eggshells. Its structural properties were investigated by scanning (SEM), transmission (TEM) electron microscopies and Fourier Transformed Infrared spectroscopy (FT-IR). The composition analyses of HA were measured by the total reflection X-ray fluorescence spectrometer (TXRF) and by prompt gamma activation analysis (PGAA). Hydroxyapatite added biodegradable scaffolds have been prepared by electrospinning method to enhance biological functionality. 相似文献
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Antipyrine derivatives I (Z = O, S; Z1 = CH2, CH2OCH2; n = 0, 1, 2, 3) were prepared as open-chain crown ether analogs. Thus, refluxing diethylene glycol ditosylate with 4-hydroxyantipyrine and K2CO3 in acetone for 15 h gave I (Z = O, Z1 = CH2OCH2). The activities of I as phase-transfer catalyst for iodination of 1-bromoctane with NaI, or KI were reported. 相似文献
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大孔的苯乙烯-二乙烯苯共聚物经氯甲基化后,分别与乙酰丙酮镍、乙酰丙酮钠和四正丁基乙酰丙酮铵三种不同的乙酰丙酮盐反应,可制得聚3-(p-乙烯苄基)戊二酮-[2,4]。其中以由乙酰丙酮镍制得的聚合物最好,除二乙烯苯外,78%左右的苯环乙酰丙酮化了。该聚合物螯合Fe~(3 )和Ni~(2 )的能力与β-二酮基高聚物相仿或稍优。还比较了此类高聚物的物理机械性能。 相似文献
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表面活性剂对金属荧光反应的增敏作用 总被引:9,自引:0,他引:9
研究了各种类型的表面活性剂对铪-栎精、锆-栎精、锡-桑色素、镁-8-羟基喹啉-5-磺酸(镁-H_QS)、锌-H_2QS、镉-H_2QS、铽-EDTA-磺基水杨酸体系荧光光谱的影响.结果表明:在适当的表面活性剂存在下,各种配合物的荧光强度均大大增强.确定了在有表面活性剂参与下三元配合物的最佳形成条件;以荧光法测定了这些荧光配合物的组成.用相对法测定了有表面活性剂和没有表面活性剂存在时荧光配合物的量子效率,并计算了在激发波长下各自的摩尔吸光系数.发现在有表面活性剂存在时,由于生成了有固定组成的三元离子缔合物,荧光配合物的量子效率和摩尔吸光系数都有不同程度的提高,从而大大增强了它们的荧光强度.讨论了表面活性剂胶束的作用以及表面活性剂的分子结构对荧光反应的影响.指出只有那些分子中带电荷基团与共轭大π键不相邻的表面活性剂才能对荧光反应起增敏作用.利用表面活性剂的增敏作用有可能建立一些高灵敏度的金属荧光分析法. 相似文献
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MoCl5或WCl6与锌粉及适当的膦配体和CO在常压常温进行反应,合成了含膦配体的炭基钼和钨的化合物(Ph2PR)nM(CO)6-n(M=Mo,W;R=ME,Et,n-Pr,Ph;n=2,3),用该方法也成功地将M(CO)5(M=Mo,W)单元负载到含膦的高分子链上,化合物(Ph2PEt)2Mo(CO)4与HgCl2反应得到含Mo-Hg键的化合物。用(Ph3P)2Mo(CO)4和(Ph3P)2Ni(CO)2二元催化体系,在适当温度和压力下对甲醇羰基化反应进行初步研究,得到了初步研究,得到了醋酸和醋酸甲酯。该催化过程对甲醇的转化率可达92%,对醋酸和醋酸甲酯的选择性可达68%。 相似文献
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