【作者】 朱军；

【导师】 沈玉华； 谢安建；

【作者基本信息】 安徽大学 ， 无机化学， 2005， 硕士

【摘要】 尿结石是人体内异常矿化的产物,也是危害人体健康的泌尿系统疾病。它是由某些无机盐结晶分散在有机基质中形成的,其中晶体的主要成分为草酸钙,且大都是一水草酸钙（COM）,而有机基质主要是蛋白质和多糖等。人们从尿结石的剖面图上发现其具有环状同心层结构,但其形成原因尚不清楚。我们选取多聚糖—琼脂凝胶作为介质,在一维、二维体系中模拟多种因素对草酸钙晶体生长及形成类似尿结石斑图结构中周期性环状沉淀的影响。 本论文主要分为四部分,主要内容如下: 第一部分:在一维凝胶体系中模拟草酸钙晶体的生长。采用XRD、FT-IR对晶体进行表征。结果发现在此条件下,得到了不同晶型的水合草酸钙,有棱角圆滑的薄片状的过渡态型、棒状及类球形等晶体出现。其中晶体组成以最不稳定的三水草酸钙（COT）为主,最稳定的COM次之,较稳定的二水草酸钙（COD）最少。由此说明在晶体生长过程中,琼脂介质体系降低了其界面能,提供成核位点,促进晶体异相成核和高能晶体的生成。 第二部分:在二维凝胶圆盘体系中,研究了加入不同生物分子等络合剂对晶体形貌的影响。结果发现在未加生物分子等络合剂的草酸钙-琼脂二维体系胶中所产生的晶体为截面为六边形的COM、四方锥形的COD和四边形的COT的三种晶型的晶体,且COM的含量较高;加入植酸、尿酸、天冬氨酸的二维体系中草酸钙晶体的COM、COT和COD三种晶型同时存在,但COM的含量明显降低了;而在加柠檬酸钠、乙二胺四乙酸钠和葡萄糖的草酸钙-琼脂二维体系胶中只存在COT和COD两种晶型晶体,COM被强烈抑制。表明上述生物分子等络合剂在一定环境中可有效地抑制尿结石的主要成分COM的形成。 第三部分:在二维凝胶圆盘体系中,研究稀土离子(La³⁺、Pr³⁺、Nd³⁺、Tb³⁺和Er³⁺)对草酸钙晶体生长和周期性环状沉淀的影响,并通过FT-IR、XRD等测试方法对其结构和性质进行分析。结果表明,在一定条件下,轻、重稀土离子都能促进周期性环状沉淀的产生。但环的形成时间、大小、数目又会因稀土离子的种类、浓度、扩散方式而不同。这可能是因为它们与Ca²⁺的性质十分相似,且与含氧配体结合能力较强,所以能促进周期性环状沉淀的形成。此外更多还原

【Abstract】 Urinary stone is the product of abnormal biomineralization in vivo. It is a kind of disease in urinary system. Urinary stone is composed of organic matrices containing polysaccharide, protein and inorganic salts, such as calcium oxalate （CaC₂O₄）, especially calcium oxalate monohydrate （COM） crystal. Researchers have found the ringed homocentric structures in the section of urinary stone, but the formation mechanism remains unclear. Therefore, in this paper, polysaccharide-agar gel system is used as a template to study the growth of CaC₂O₄ crystal and the formation of periodic ringed precipitation in agar gel systems.The paper is separated into four parts that are shown as follows:1. The growth of CaC₂O₄ crystals was studied in one dimension agar gel system and the crystals were characterized using XRD and FT-IR spectra. The results show that there were lamellar, rod and sphere-like CaC₂O₄ hydrate in the gel. The content of triclinic trihydrate （COT）, which was most unstable in normal condition, was the highest while the content of tetragonal dihydrate （COD） was the lowest in the gel. Those suggest that agar system diminished interfacial energy, offered nucleation site, and promoted heterogeneous nucleation of crystal and growth of high-energy crystal.2. Influences of different ligands including some biomolecules on crystallization of calcium oxalate were studied in the CaC₂O₄-agar two-dimensional disc system. A mixture of calcium oxalate monohydrate （COM）, calcium oxalate dihydrate（COD） and COT were obtained in the absence of ligands, and the content of COM was higher. All the three crystal forms, i.e., COM, COD and COT, were obtained in the presence of phytic acid, uric acid and aspartic acid, but the content of COM decreased apparently. The mixture of COT and COD occurred in the two-dimensional system containing sodium citrate, EDTA and dextrose, the formation of COM was inhibited. The experiment results suggest that all the ligands mentioned above can inhibit effectively the formation of COM in the CaC₂O₄-agar two-dimensional gel system.3. Influences of rare earth ions （La3+, Pr3+, Nd3+Gd3+, Tb3+ and Er3+） on crystallization of calcium oxalate and the fonnation of periodic ringed precipitation were studied in the two-dimensional agar gel system. Meanwhile, the structures and the properties of the crystals were characterized by XRD and FT-IR. The results show that light and heavy rare earth ions all can promote the fonnation of periodic ringed precipitation in the above system. The formation time, the size and the number of rings changed with the concentration and radius of rare ions. It demonstrates rare ions can promote the formation of periodic ringed precipitation. Rare ions are similar to Ca2+ in the property and have strong coordination with oxo-ligand, so they may exist in the periodic ringed precipitation. In addition, it was found that the fonnation of COM was promoted by the addition of Er3+and inhibited by the addition of Nd3+ and La3+. The formation mechanism of periodic ringed precipitation was discussed.4. Influences of transition metal ions and Li+ on crystallization of calcium oxalate and the formation of periodic ringed precipitation were investigated in the two-dimensional agar gel system. The results indicate that periodic ringed precipitation produced with a certain concentration of Fe3+, and the formation of COM was inhibited. In addition, the main crystal form is COD in the gel with Zn2+, Co2+, Ni2+ and U+, while COT in the gel with Cu2+. These results show that different metal ions had different influence on the crystallization of CaC2O4. Furthermore, the special phenomena in agar gel which was similar to the blaze and the radial stripe in urinary Stone were discussed.更多还原