We investigated the prognostic importance of noninvasive factors in predicting sperm retrieval failure in idiopathic nonobstructive azoospermia(iNOA).We studied 193 patients with nonobstructive azoospermia who underwe...We investigated the prognostic importance of noninvasive factors in predicting sperm retrieval failure in idiopathic nonobstructive azoospermia(iNOA).We studied 193 patients with nonobstructive azoospermia who underwent microsurgical testicular sperm extraction.The Chi-square test and Mann–Whitney U tests for clinical parameters and seminiferous tubule distribution were used for between-group comparisons.A logistic regression analysis was conducted to identify predictors of retrieval failure.Area under the receiver operating characteristic curve for each variable was evaluated,and the net clinical benefit was calculated using a clinical decision curve.Patients with iNOA had a lower sperm retrieval rate than those with known causes.Moreover,testicular volume was an independent factor affecting sperm extraction outcomes(odds ratio=0.79,P<0.05).The testicular volume cut-off value was 6.5 ml(area under the curve:0.694).The patients with iNOA were categorized into two groups on the basis of the distribution of seminiferous tubules observed.The sperm retrieval rate and testicular volume were significantly different between the groups with a uniform or heterogeneous tubule distribution.There was also a significant association between a uniform tubule distribution and testicular volume.In conclusion,a testicular volume of more than 6.5 ml effectively predicts microsurgical testicular sperm extraction failure due to a uniform tubule distribution in patients with iNOA.展开更多
针对目前体积最大化端元提取技术存在提取精度低、计算复杂性高等问题,提出了结合遗传算法和体积最大化的端元提取方法(Extraction Method Based on Genetic Algorithm and Volume Maximization,EE-GAVM),以改进现有的端元提取技术。EE-...针对目前体积最大化端元提取技术存在提取精度低、计算复杂性高等问题,提出了结合遗传算法和体积最大化的端元提取方法(Extraction Method Based on Genetic Algorithm and Volume Maximization,EE-GAVM),以改进现有的端元提取技术。EE-GAVM方法通过寻找单纯形体积最大的像元向量集合来定位到端元集合,将端元提取问题表述为单一目标,节约计算资源的同时实现了精度的提高。实验结果表明:所提方法在性能和精度方面优于其他对比算法。展开更多
文摘We investigated the prognostic importance of noninvasive factors in predicting sperm retrieval failure in idiopathic nonobstructive azoospermia(iNOA).We studied 193 patients with nonobstructive azoospermia who underwent microsurgical testicular sperm extraction.The Chi-square test and Mann–Whitney U tests for clinical parameters and seminiferous tubule distribution were used for between-group comparisons.A logistic regression analysis was conducted to identify predictors of retrieval failure.Area under the receiver operating characteristic curve for each variable was evaluated,and the net clinical benefit was calculated using a clinical decision curve.Patients with iNOA had a lower sperm retrieval rate than those with known causes.Moreover,testicular volume was an independent factor affecting sperm extraction outcomes(odds ratio=0.79,P<0.05).The testicular volume cut-off value was 6.5 ml(area under the curve:0.694).The patients with iNOA were categorized into two groups on the basis of the distribution of seminiferous tubules observed.The sperm retrieval rate and testicular volume were significantly different between the groups with a uniform or heterogeneous tubule distribution.There was also a significant association between a uniform tubule distribution and testicular volume.In conclusion,a testicular volume of more than 6.5 ml effectively predicts microsurgical testicular sperm extraction failure due to a uniform tubule distribution in patients with iNOA.
文摘针对目前体积最大化端元提取技术存在提取精度低、计算复杂性高等问题,提出了结合遗传算法和体积最大化的端元提取方法(Extraction Method Based on Genetic Algorithm and Volume Maximization,EE-GAVM),以改进现有的端元提取技术。EE-GAVM方法通过寻找单纯形体积最大的像元向量集合来定位到端元集合,将端元提取问题表述为单一目标,节约计算资源的同时实现了精度的提高。实验结果表明:所提方法在性能和精度方面优于其他对比算法。
