Characterization of the adsorption state of carbonate ions at the Au(111) electrode surface using in situ IRAS

The spectro-electrochemical behavior of carbonate and bicarbonate ions at the Au(111) electrode surface was studied using the infrared reflection absorption spectroscopy (IRAS). An absorption band caused by the adsorbed carbonate ions was observed in the wavenumber region of 1425–1511 cm⁻¹ both in Na₂CO₃ and NaHCO₃ solutions. It was concluded that the adsorbed carbonate ions co-ordinate with the electrode surface in the unidentate state with their symmetry axis normal to the substrate. This orientation is retained in the whole potential region where carbonate ions adsorb on the electrode surface in contrast to the behavior of the carbonate ions adsorbed on the Pt(111) electrode surface.     

L-赖氨酸双酶电极的研制及应用

用交联法将赖氨酸脱羧酶与碳酸酐酶共同固定于CO_2电极透气膜上,制成L-赖氨酸双酶电极,讨论了该双酶电极的响应特性。用双酶电极测定了金针菇和强化赖氨酸食品中赖氨酸含量,与氨基酸自动分析仪所得结果一致。     

双模板介导合成类骨磷灰石的研究进展

天然骨形成是一个多模板协同共组装的过程。与单模板自组装相比,双模板介导合成的类骨磷灰石具有与天然骨更加相近的多级结构,在生物矿化研究领域具有更重要的研究意义。本文介绍了双模板介导合成类骨磷灰石的研究进展,探讨了双模板的选择、设计及模板分子间的相互作用,阐述了模板对磷灰石晶体成核的调控机制。通过双模板介导自组装生成的磷灰石材料,以其特有的仿生多级结构和骨诱导效果,在骨缺损修复、齿科修复、表面涂层及药物载体等领域具有广阔的应用前景。     

Über die Identität eines sogenannten Ammoniumcarbonat‐Präparates

On the Identity of a so‐called Ammonium Carbonate Sample Commercial samples of so‐called “ammionum carbonate” are shown to contain ammonium carbamate rather than ammonium carbonate. In fact samples may contain varying quantities of α‐ and β‐(NH₄)(CO₂NH₂), of which only the α‐phase is reported in the literature. Mixtures of both phases tend to leak the volatile α‐phase and to react with moisture to form (NH₄)(HCO₃). The crystal structure of the new β‐(NH₄)(CO₂NH₂) is refined from X‐ray powder data.     

牛血清蛋白单层膜诱导形成网状结构的羟基磷灰石

0引言近来利用生物矿化的方法来合成具有特殊结构的晶体材料成为材料合成的一个热点[1.2]。羟基磷灰石(HAP)作为一种生物材料,广泛地存在于人和动物的骨骼和牙齿中,是生物矿化的产物。在骨骼的修复、替代和仿生抗菌陶瓷薄膜中有重要的应用[3]。因此,利用生物矿化的方法合成具有     

羟基磷灰石-碳酸钙-BSA水溶性复合物中蛋白质微观结构的研究

利用傅里叶变换红外光谱，结合二阶导数谱、退卷、积和曲线拟合等计算机解析方法，对牛血清白蛋白（BSA）－羟基磷灰灰石－碳酸钙水溶性复合物中BSA的二级结构进行了研究。结果表明，BSA的α－螺旋结构的含量增加，蛋白质结构趋于有序化；紫外光谱和紫外二阶导数谱的研究发现，BSA的芳香族氨基酸残基的微环境受到扰动，在生物体内，正是蛋白质结构的这些变化导致生物矿化过程的发生和进行。     

水热重结晶法制备羟基磷灰石纳米棒

本文以Ca(NO₃)₂和(NH₄)₂HPO₄为原料，采用重结晶法，在水热条件下制备了羟基磷灰石(HA)纳米棒；利用X-射线衍射(XRD)、透射电镜(TEM)、高分辨透射电镜(HRTEM)、红外光谱(FTIR)等分析测试手段，研究了pH值和晶化时间对HA组成和结构的影响。实验结果表明，室温混合pH值为7.5的沉淀物和pH值为10.5的清液，于180 ℃下水热处理10 h重结晶制得的HA纳米棒的平均长径比最长(约为28)；采用不同pH值的清液，体系的单体浓度(即化学势)改变时，得到的HA纳米棒的长径比不同；随着晶化时间延长，纳米棒的长径比先增大后减小。     

Effect of Hydroxyapatite Reinforced with 45S5 Glass on Physical,Structural and Mechanical Properties

This paper presents a study of physical and structural properties of Hydroxyapatite (HA) reinforced with different compositions of 45S5 (SG) bioglasses at different sintering temperatures. Hydroxyapatite reinforced with different compositions of 45S5 bioglasses had been prepared and investigated in terms of density, mechanical strength, and crystalline phases. A decrease in the density of HA was observed after the incorporation of SG, owing to the trapping of air in the SG reinforced HA after sintering process. When compared to the pure HA, different crystalline phases, such as β-tricalcium phosphate, calcium phosphate silicate and sodium calcium phosphate, were detected when different compositions of SG were incorporated into the HA     

Environmentally benign fabrication of calcium hydroxyapatite using seashells collected in Baltic Sea countries: A comparative study

In this study, high purity crystalline calcium hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂; CHAp) was fabricated from seashells collected in different regions of the Baltic Sea using an environment-friendly water-based sol-gel synthesis route. The phase composition of the synthesized CHAp powders was studied by X-ray diffraction analysis and Fourier transform infrared spectroscopy. The surface morphologies of the precursors and synthesized samples were examined by scanning electron microscopy. A single shell type, Macoma balthica (L.), was collected from various locations around the Baltic Sea. Nevertheless, the resulting CHAp powders had surprisingly large variations in the surface morphology of sol-gel-derived CHAp bioceramics.     

One‐Step Synthesis of Silver Nanoparticle‐Decorated Hydroxyapatite Nanowires for the Construction of Highly Flexible Free‐Standing Paper with High Antibacterial Activity

A highly flexible and free‐standing paper with high antibacterial activity made from silver nanoparticle (AgNP)‐decorated ultralong hydroxyapatite nanowires (HAPNWs) is reported. The HAPNWs@AgNPs nanocomposites were obtained from a facile one‐step solvothermal process and utilized for the construction of highly flexible and free‐standing inorganic paper through a simple vacuum‐filtration procedure. The structure and properties of the HAPNWs@AgNPs paper were characterized in detail. Scanning electron microscope (SEM) and transmission electron microscope (TEM) micrographs show that AgNPs are highly dispersed and stabilized in the nanocomposite and exhibit a narrow particle size distribution. The effects of the concentration of silver nitrate, solvothermal temperature and time on the product were systematically investigated. This method is simple, convenient and reproducible. The as‐prepared HAPNWs@AgNPs paper shows long‐time sustained silver‐ion release, high antibacterial activity against both Gram‐negative and Gram‐positive bacteria, and good biocompatibility. Overall, this work provides a novel pathway for the preparation of a new type of highly flexible, free‐standing and antibacterial inorganic paper made from silver nanoparticle‐decorated hydroxyapatite nanowires for various applications, as a promising functional biomaterial.