Johrde L G, Cocks F H
J Biomed Mater Res. 1986 Sep;20(7):945-50. doi: 10.1002/jbm.820200709.
The effects of synthetic urine environments of pH 4, 6, and 9.5 on the microhardness of renal calculi have been investigated. Tests were made, using both Vickers and Knoop indenters, on three compositions of calculi: 100% calcium oxalate monohydrate (whewellite), 100% uric acid, and 98% magnesium ammonium phosphate hexahydrate (struvite) mixed with 2% carbonate apatite. Whewellite calculi hardness was lowered, relative to (dry) values by 45-55% when saturated with a solution of pH 9.5. Exposure to lower pH conditions was not as effective in lowering hardness in this case. Struvite calculi hardness was lowered by 41-52% compared to the dry hardness and uric acid calculi hardness decreased by 25-36%, compared to dry hardnesses. For uric acid stones the reduction in hardness did not depend on pH within the range of pH values investigated. For struvite stones, acid pH conditions appear to give an increased softening, compared to other pH values.
研究了pH值为4、6和9.5的合成尿液环境对肾结石显微硬度的影响。使用维氏压头和努氏压头对三种结石成分进行了测试：100%一水合草酸钙（水草酸钙）、100%尿酸以及98%六水合磷酸镁铵（鸟粪石）与2%碳酸磷灰石的混合物。当用pH值为9.5的溶液饱和时，水草酸钙结石的硬度相对于（干燥）值降低了45 - 55%。在这种情况下，暴露于较低pH条件下降低硬度的效果不那么显著。与干燥硬度相比，鸟粪石结石的硬度降低了41 - 52%，尿酸结石的硬度降低了25 - 36%。对于尿酸结石，在所研究的pH值范围内，硬度的降低并不取决于pH值。对于鸟粪石结石，与其他pH值相比，酸性pH条件似乎会导致更大程度的软化。
