目的比较S. T. O. N. E.肾结石评分与Guy肾结石分级对经皮肾镜取石术(percutaneous nephroscope lithoipsy,PCNL)结石清除率预测的准确性。方法选择2015-01至2017-12在西安交通大学第二附属医院接受PCNL的患者146例,术前分别进行S. T. O...目的比较S. T. O. N. E.肾结石评分与Guy肾结石分级对经皮肾镜取石术(percutaneous nephroscope lithoipsy,PCNL)结石清除率预测的准确性。方法选择2015-01至2017-12在西安交通大学第二附属医院接受PCNL的患者146例,术前分别进行S. T. O. N. E.评分和Guy分级。术后统计结石清除率,分别计算S. T. O. N. E.评分和Guy分级的ROC曲线下面积,对比两种方法预测的准确性。结果结石清除率为73. 97%。S. T. O. N. E.肾结石评分预测PCNL术后结石清除率的准确性为74. 8%,最佳阈值为8. 5分,灵敏度为73. 7%,特异度为71. 3%; Guy分级预测PCNL术后结石清除率的准确性为71. 5%,最佳阈值为2. 5级,灵敏度为71. 1%,特异度为64. 8%。两种方法的ROC曲线下面积分别为0. 748和0. 715,无统计学差异。结论 S. T. O. N. E.评分与Guy分级均具有中等水平预测能力,均可用来评估PCNL术后结石清除率,两个方法的预测能力未见统计学差别。展开更多
In this paper, Ni/Zr–Yb–O catalysts with different sodium contents are prepared by a co-precipitation method, using aqueous Na2CO3 solution as a precipitant, and the effect of sodium on the catalyst structure and ca...In this paper, Ni/Zr–Yb–O catalysts with different sodium contents are prepared by a co-precipitation method, using aqueous Na2CO3 solution as a precipitant, and the effect of sodium on the catalyst structure and catalytic performance for syngas methanation is extensively investigated using five Ni/Zr–Yb–O catalysts, containing 0, 0.5, 1.5,4.5 and 13.5 wt% Na^+, those are denoted as Cat-1, Cat-2, Cat-3, Cat-4 and Cat-5 respectively. It is found that the interaction between Ni and support determines the catalytic performance of Ni/Zr–Yb–O and the residual sodium content negatively affects the interaction between Ni and support. Cat-1 exhibits an excellent catalytic performance.During a long run time of 380 h, no deactivation is observed and both CO conversion and CH4 selectivity maintain a level above 90%. However, Cat-3 and Cat-5 suffer rapid deactivation under the same reaction condition. The characterization results indicate the strong interaction between Ni and support enables Cat-1 to possess well dispersed Ni species, resistance to sintering and carbon deposition and thus the excellent catalytic performance. However, the presence of sodium ions over Ni/Zr–Yb–O degrades the interaction between Ni and support and the catalytic performance, especially for the stability. The relative weak interaction between Ni and support results in severe sintering of both ZrO2 and Ni under the reaction condition, carbon deposition and the poor catalytic performance.展开更多
文摘目的比较S. T. O. N. E.肾结石评分与Guy肾结石分级对经皮肾镜取石术(percutaneous nephroscope lithoipsy,PCNL)结石清除率预测的准确性。方法选择2015-01至2017-12在西安交通大学第二附属医院接受PCNL的患者146例,术前分别进行S. T. O. N. E.评分和Guy分级。术后统计结石清除率,分别计算S. T. O. N. E.评分和Guy分级的ROC曲线下面积,对比两种方法预测的准确性。结果结石清除率为73. 97%。S. T. O. N. E.肾结石评分预测PCNL术后结石清除率的准确性为74. 8%,最佳阈值为8. 5分,灵敏度为73. 7%,特异度为71. 3%; Guy分级预测PCNL术后结石清除率的准确性为71. 5%,最佳阈值为2. 5级,灵敏度为71. 1%,特异度为64. 8%。两种方法的ROC曲线下面积分别为0. 748和0. 715,无统计学差异。结论 S. T. O. N. E.评分与Guy分级均具有中等水平预测能力,均可用来评估PCNL术后结石清除率,两个方法的预测能力未见统计学差别。
基金Supported by the National Natural Science Foundation of China(21673187,21336009,21576228)National Key Technology Support Program of China(2014BAC10B01).
文摘In this paper, Ni/Zr–Yb–O catalysts with different sodium contents are prepared by a co-precipitation method, using aqueous Na2CO3 solution as a precipitant, and the effect of sodium on the catalyst structure and catalytic performance for syngas methanation is extensively investigated using five Ni/Zr–Yb–O catalysts, containing 0, 0.5, 1.5,4.5 and 13.5 wt% Na^+, those are denoted as Cat-1, Cat-2, Cat-3, Cat-4 and Cat-5 respectively. It is found that the interaction between Ni and support determines the catalytic performance of Ni/Zr–Yb–O and the residual sodium content negatively affects the interaction between Ni and support. Cat-1 exhibits an excellent catalytic performance.During a long run time of 380 h, no deactivation is observed and both CO conversion and CH4 selectivity maintain a level above 90%. However, Cat-3 and Cat-5 suffer rapid deactivation under the same reaction condition. The characterization results indicate the strong interaction between Ni and support enables Cat-1 to possess well dispersed Ni species, resistance to sintering and carbon deposition and thus the excellent catalytic performance. However, the presence of sodium ions over Ni/Zr–Yb–O degrades the interaction between Ni and support and the catalytic performance, especially for the stability. The relative weak interaction between Ni and support results in severe sintering of both ZrO2 and Ni under the reaction condition, carbon deposition and the poor catalytic performance.
