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41.
Lachezar Radev Vladimir Hristov Irena Michailova Bisserka Samuneva 《Central European Journal of Chemistry》2009,7(3):322-327
Ceramics, with basic composition based on the CaO-SiO2-P2O5-MgO system with different Ca+ Mg/P+Si molar ratio (R), were prepared via polystep sol-gel technique. The structure of the
obtained ceramic materials has been studied by XRD, FTIR spectroscopy, and SEM. X-ray diffraction showed the presence of akermanite
and HA for the sample with R = 1.68 and Mg substituted β-TCP and silicocarnotite for the sample with R = 2.16, after thermal
treatment at 1200°C/2 h. The obtained results are in good agreement with FTIR. In vitro test for bioactivity in static condition
proved that the carbonate containing hydroxyapatite (CO3HA) can be formed on the surface of the synthesized samples. CO3HA consisted of both A- and B-type CO32− ions. SEM micrographs depicted different forms of HA particles, precipitated on the surface after soaking in 1.5 simulated
body fluid (SBF).
相似文献
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43.
哺乳类催产素及其衍生物是一系列包含S—S键的多肽分子. 应用原子-键电负性均衡σπ(ABEEMσπ)模型, 我们研究了该系列多肽分子的分子内氢键和整体软度与生物活性关系. 首先利用点电荷模型计算了该系列多肽分子的分子内氢键能, 并与实验值对比, 得到了基本一致的结果. 再根据整体软度与生物活性的关系: 即整体软度越大, 分子生物活性越大, 我们成功解释了催产素及其衍生物的分子生物活性的变化关系. 将ABEEMσπ模型初步应用于研究含 S—S键多肽的相关性质方面, 并取得了和实验以及其它理论计算较为一致的结果. 因此, 以上研究为该模型进一步探讨其它多肽的相关性质提供了一定的理论基础. 相似文献
44.
Feifei Zhang Qi Gao Bang Chen Wei Sun Dongxu Lv 《Phosphorus, sulfur, and silicon and the related elements》2016,191(5):786-789
An efficient one-pot, cyclocondensation of ammonium acetate, 1,2-diphenyl ethanedione, aromatic aldehyde or arylamine, and catalyzed by boric acid is achieved to form multisubstituted imidazole derivatives. Boric acid as green property is harmless to the environment and has improved the yield of multisubstituted imidazole derivatives. Moreover, we have tested the biological activities of imidazole derivatives by the four fungi. And the investigations showed most of imidazole derivatives have antifungal action on four fungus. 相似文献
45.
以2-苄硫基-5-甲基-7-羟基-1,2,4-三唑并[1,5-a]嘧啶为原料,经醚化、肼解、成盐、关环和席夫碱反应合成了20个新型的含1,2,4-三唑-5-硫酮席夫碱的1,2,4-三唑并[1,5-a]嘧啶类化合物,通过IR,1H NMR,MS和元素分析对所合成的化合物进行了结构表征.初步生物活性测试结果表明,部分化合物表现出一定的抑菌或较好的抗烟草花叶病毒(TMV)活性.在500μg/mL浓度下,化合物6b,6f和6p对TMV的抑制率分别为41%,43%和40%. 相似文献
46.
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硫酸二甲酯作为N-甲基化试剂,与相应的异噁唑啉反应,并在盐酸中三氯化铁作为阴离子交换试剂,合成了15个未见文献报道的2-甲基-3-(1’,2’-二-O-环亚己基二氧乙基)-5-芳基-3a,6a-二氢-4,6-二氧代氮杂茂并[3’,4’-d]异噁唑四氯化铁酸盐衍生物4a~4o.化合物4a~4o结构结构经1H NMR,IR和元素分析确证,并进行了初步药物活性筛选,大部分化合物显示了不同程度的抗癌和抗炎症性及免疫性疾病活性.体外抗癌活性试验表明,当样品浓度为20μg/mL时,除了4h无活性外,其余化合物对细胞分裂周期磷酸酯酶Cdc25B的抑制率为≥97.55%.此外,体外白细胞共同抗原活性试验表明,当样品浓度为20μg/mL时,所有化合物4a~4o对白细胞共同抗原CD45蛋白酪氨酸磷酸酶A具有良好的抑制活性,其抑制率为68.41%~93.38%.在此基础上,初步讨论了该类化合物的构效关系. 相似文献
48.
《Journal of Coordination Chemistry》2012,65(3):165-173
Abstract A new series of water soluble platinum(II) complexes of the type [Pt(DACH)[R-CH(COO)2]], wherein DACH represents IR,2R-cyclohexanediamine and R represents formamido. acetamido, (penta-O-acctyl-gluconyl)amino, and gluconylamino have been synthesized. The modes of binding of amidodicarboxylic acid derivatives in these complexes have been determined by various spectroscopic techniques: 1H, 13 C, and 195PtNMR; 2D-COSY{1H-1H} and 2D-HETCOSY{1H-13C} NMR, MS(FAB), IR and conductivity measurements. 相似文献
49.
Suck‐Kyu Cho Il‐Song Park Sook‐Jeong Lee Kyoung‐A Kim Ju‐Mi Park Seung‐Geun Ahn Kwang‐Yeob Song Dong‐Joo Yoon Min‐Ho Lee 《Surface and interface analysis : SIA》2012,44(1):114-120
The use of titanium‐based alloys as biomaterials is becoming more common because they have a reduced elastic modulus, superior biocompatibility, specific strength, good corrosion resistance, superior strain control, and fatigue resistance compared to conventional stainless steel and Co? Cr alloys. However, when implanted into the human body these metals are problematic because they do not directly bond with living bone. Surface treatments play an important role in nucleating calcium phosphate deposition on a surgical titanium alloy implant. The purpose of this study is to examine whether the precipitation of apatite on Ti? 10Ta? 10Nb alloy is affected by surface modification in H2O2 solution. Specimens were chemically treated with a solution containing 30 wt% H2O2 at 80 °C for 1 h, and subsequently heat treated at 400 °C for 1 h. All specimens were immersed in SBF (Simulated Body Fluid) with a pH of 7.4 at 36.5 °C for seven days, and the surfaces were examined with XRD, SEM, EDX and in vitro testing. The microstructure analysis of the Ti? 10Ta? 10Nb alloy after etching with Keller's etchant showed a Widmanstatten pattern. The micro‐Vickers hardness number was 236.44 ± 4.99, and surface roughness was increased by the surface treatment. The wettability after surface treatment was better than on the nontreated surface. Resistance to cytotoxicity was decreased by the chemical surface treatment (P < 0.05). Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
50.
P.Vijai Bharathy D. Nataraj Q. Yang M.S.R.N. Kiran 《Surface and interface analysis : SIA》2012,44(3):288-295
In this paper, the influence of nickel incorporation on the mechanical properties and the in vitro bioactivity of hydrogenated carbon thin films were investigated in detail. Amorphous hydrogenated carbon (a‐C:H) and nickel‐incorporated hydrogenated carbon (Ni/a‐C:H) thin films were deposited onto the Si substrates by using reactive biased target ion beam deposition technique. The films' chemical composition, surface roughness, microstructure and mechanical properties were investigated by using XPS, AFM, TEM, nanoindentation and nanoscratch test, respectively. XPS results have shown that the film surface is mainly composed of nickel, nickel oxide and nickel hydroxide, whereas at the core is nickel carbide (Ni3C) only. The presence of Ni3C has increased the sp2 carbon content and as a result, the mechanical hardness of the film was decreased. However, Ni/a‐C:H films shows very low friction coefficient with higher scratch‐resistance behavior than that of pure a‐C:H film. In addition, in vitro bioactivity study has confirmed that it is possible to grow dense bone‐like apatite layer on Ni/a‐C:H films. Thus, the results have indicated the suitability of the films for bone‐related implant coating applications. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献