目的构建基于健康体检数据的骨密度状况三阶段模型,并在此基础上简化模型参数得到骨质疏松(osteoporosis,OP)与骨量低下(osteopenia,OST)的三阶段预测(triple-stage osteoporosis and osteopenia prediction,TOOP)指数,用于中老年人群...目的构建基于健康体检数据的骨密度状况三阶段模型,并在此基础上简化模型参数得到骨质疏松(osteoporosis,OP)与骨量低下(osteopenia,OST)的三阶段预测(triple-stage osteoporosis and osteopenia prediction,TOOP)指数,用于中老年人群骨量异常风险的初筛、预测与评估。方法回顾性收集2019年1月至2021年12月在黔南州人民医院体检中心完成双能骨密度检查的40岁及以上体检者8021例,按1∶1随机划分为拟合集与验证评估集。利用条件概率原理将三阶段预测问题转化为OP和OST的独立预测问题,并将两者结合构成TOOP指数。采用准确率、灵敏度、特异度、检出率等指标与OSTA指数进行比较验证。结果性别、年龄和体重是OP的三个主要预测因子,年龄和体重是OST的两个主要预测因子。TOOP指数的预测准确率为0.70(95%CI:0.68~0.71),高于OSTA指数(P<0.001)。TOOP指数预测OP和OST的灵敏度分别为0.46(95%CI:0.40~0.53)和0.56(95%CI:0.53~0.60),均高于OSTA指数(OP:P<0.001,OST:P<0.001);特异度分别为0.96(95%CI:0.95~0.97)和0.79(95%CI:0.77~0.81),略低于OSTA指数(OP:P<0.001,OST:P<0.001)。TOOP指数对骨量异常人群的送检率(42.0%)与检出率(32.7%)均高于OSTA指数(P<0.001),漏检率(12.4%)低于OSTA指数(P<0.001)。结论TOOP指数为中老年人群骨质疏松与骨量低下的风险初筛提供了良好的预测工具。展开更多
By means of Miedema formation enthalpy model with Toop model, the excess free-energy, enthalpies of formation, excess entropies and activity values of all components of Mg-A1-Y ternary alloy were calculated with compu...By means of Miedema formation enthalpy model with Toop model, the excess free-energy, enthalpies of formation, excess entropies and activity values of all components of Mg-A1-Y ternary alloy were calculated with computer programming. The experimental results show that enthalpies of formation, excess free- energy and excess entropies of the ternary alloy are negative in the whole content range, the minimum values at 1 123 K are all obtained at x_Al=55%, x_y=45%, X_Mg=0%, which are -37.969, -30.961 kJ/mol and -6.24 J/（mol-k） respectively. Activity curves show that the activity values of A1 and Y in Mg-A1-Y ternary alloy rapidly decrease with the decrease of molar fraction, the values of which are very small when the molar fraction decreases to 0.4. It means that there is a strong interaction between A1 and Y and stable compounds can be form in the Mg-A1-Y ternary alloy system.展开更多
文摘目的构建基于健康体检数据的骨密度状况三阶段模型,并在此基础上简化模型参数得到骨质疏松(osteoporosis,OP)与骨量低下(osteopenia,OST)的三阶段预测(triple-stage osteoporosis and osteopenia prediction,TOOP)指数,用于中老年人群骨量异常风险的初筛、预测与评估。方法回顾性收集2019年1月至2021年12月在黔南州人民医院体检中心完成双能骨密度检查的40岁及以上体检者8021例,按1∶1随机划分为拟合集与验证评估集。利用条件概率原理将三阶段预测问题转化为OP和OST的独立预测问题,并将两者结合构成TOOP指数。采用准确率、灵敏度、特异度、检出率等指标与OSTA指数进行比较验证。结果性别、年龄和体重是OP的三个主要预测因子,年龄和体重是OST的两个主要预测因子。TOOP指数的预测准确率为0.70(95%CI:0.68~0.71),高于OSTA指数(P<0.001)。TOOP指数预测OP和OST的灵敏度分别为0.46(95%CI:0.40~0.53)和0.56(95%CI:0.53~0.60),均高于OSTA指数(OP:P<0.001,OST:P<0.001);特异度分别为0.96(95%CI:0.95~0.97)和0.79(95%CI:0.77~0.81),略低于OSTA指数(OP:P<0.001,OST:P<0.001)。TOOP指数对骨量异常人群的送检率(42.0%)与检出率(32.7%)均高于OSTA指数(P<0.001),漏检率(12.4%)低于OSTA指数(P<0.001)。结论TOOP指数为中老年人群骨质疏松与骨量低下的风险初筛提供了良好的预测工具。
基金Funded by the National Natural Science Foundation of China(Nos.51165032 and 51364035)the Innovative Group of Science and Technology of College of Jiangxi Province(No.00008713)+2 种基金the Jiangxi Province Education Commission Foundation(GJJ13203)the Production and Teaching and Research Cooperation Plan of Nanchang Non-party Experts and Doctor(No.2012-CYH-DW-XCL-002)the Special Funds for Postgraduate Innovation of Jiangxi Province
文摘By means of Miedema formation enthalpy model with Toop model, the excess free-energy, enthalpies of formation, excess entropies and activity values of all components of Mg-A1-Y ternary alloy were calculated with computer programming. The experimental results show that enthalpies of formation, excess free- energy and excess entropies of the ternary alloy are negative in the whole content range, the minimum values at 1 123 K are all obtained at x_Al=55%, x_y=45%, X_Mg=0%, which are -37.969, -30.961 kJ/mol and -6.24 J/（mol-k） respectively. Activity curves show that the activity values of A1 and Y in Mg-A1-Y ternary alloy rapidly decrease with the decrease of molar fraction, the values of which are very small when the molar fraction decreases to 0.4. It means that there is a strong interaction between A1 and Y and stable compounds can be form in the Mg-A1-Y ternary alloy system.
