目的:分析多胎妊娠选择性减胎术后的围生结局。方法:回顾性分析2012年1月至2015年9月间173例多胎妊娠孕妇在广州医科大学附属第三医院胎儿医学中心通过经腹胎儿心内注射氯化钾(KCL)减胎术或射频消融(RFA)减胎术将多胎妊娠减至单胎或双...目的:分析多胎妊娠选择性减胎术后的围生结局。方法:回顾性分析2012年1月至2015年9月间173例多胎妊娠孕妇在广州医科大学附属第三医院胎儿医学中心通过经腹胎儿心内注射氯化钾(KCL)减胎术或射频消融(RFA)减胎术将多胎妊娠减至单胎或双胎的临床资料,分析减胎术后的围生结局。结果:KCL减胎术121例,术后流产率为10.0%,围生儿存活率89.2%。孕早期的流产率、≤34周早产率与孕中期比较,差异无统计学意义(P>0.05);保留单胎的分娩孕周较保留双胎的延长约2周(37.96±2.65周vs 35.93±2.19周)且新生儿体质量更重(2.91±0.55 kg vs 2.51±0.44kg),差异有统计学意义(P<0.05)。RFA减胎术52例,术后围生儿存活率为71.2%。双胎输血综合征(TTTS)、选择性胎儿生长受限(s FGR)、双胎反向灌注序列综合征(TRAPs)、双胎之一结构或遗传异常术后的存活率分别为68.2%、83.3%、100.0%、53.8%。结论:KCL减胎术可在孕早中期进行,减至单胎可能更有益于围生结局。RFA减胎术中s FGR和TRAPs术后的存活率较高。选择性减胎术对改善多胎妊娠的围生结局有益。展开更多
In this paper,the advantage of using numerical models with the strength reduction method(SRM) to evaluate entry stability in complex multiple-seam conditions is demonstrated.A coal mine under variable topography from ...In this paper,the advantage of using numerical models with the strength reduction method(SRM) to evaluate entry stability in complex multiple-seam conditions is demonstrated.A coal mine under variable topography from the Central Appalachian region is used as a case study.At this mine,unexpected roof conditions were encountered during development below previously mined panels.Stress mapping and observation of ground conditions were used to quantify the success of entry support systems in three room-and-pillar panels.Numerical model analyses were initially conducted to estimate the stresses induced by the multiple-seam mining at the locations of the affected entries.The SRM was used to quantify the stability factor of the supported roof of the entries at selected locations.The SRM-calculated stability factors were compared with observations made during the site visits,and the results demonstrate that the SRM adequately identifies the unexpected roof conditions in this complex case.It is concluded that the SRM can be used to effectively evaluate the likely success of roof supports and the stability condition of entries in coal mines.展开更多
文摘目的:分析多胎妊娠选择性减胎术后的围生结局。方法:回顾性分析2012年1月至2015年9月间173例多胎妊娠孕妇在广州医科大学附属第三医院胎儿医学中心通过经腹胎儿心内注射氯化钾(KCL)减胎术或射频消融(RFA)减胎术将多胎妊娠减至单胎或双胎的临床资料,分析减胎术后的围生结局。结果:KCL减胎术121例,术后流产率为10.0%,围生儿存活率89.2%。孕早期的流产率、≤34周早产率与孕中期比较,差异无统计学意义(P>0.05);保留单胎的分娩孕周较保留双胎的延长约2周(37.96±2.65周vs 35.93±2.19周)且新生儿体质量更重(2.91±0.55 kg vs 2.51±0.44kg),差异有统计学意义(P<0.05)。RFA减胎术52例,术后围生儿存活率为71.2%。双胎输血综合征(TTTS)、选择性胎儿生长受限(s FGR)、双胎反向灌注序列综合征(TRAPs)、双胎之一结构或遗传异常术后的存活率分别为68.2%、83.3%、100.0%、53.8%。结论:KCL减胎术可在孕早中期进行,减至单胎可能更有益于围生结局。RFA减胎术中s FGR和TRAPs术后的存活率较高。选择性减胎术对改善多胎妊娠的围生结局有益。
文摘In this paper,the advantage of using numerical models with the strength reduction method(SRM) to evaluate entry stability in complex multiple-seam conditions is demonstrated.A coal mine under variable topography from the Central Appalachian region is used as a case study.At this mine,unexpected roof conditions were encountered during development below previously mined panels.Stress mapping and observation of ground conditions were used to quantify the success of entry support systems in three room-and-pillar panels.Numerical model analyses were initially conducted to estimate the stresses induced by the multiple-seam mining at the locations of the affected entries.The SRM was used to quantify the stability factor of the supported roof of the entries at selected locations.The SRM-calculated stability factors were compared with observations made during the site visits,and the results demonstrate that the SRM adequately identifies the unexpected roof conditions in this complex case.It is concluded that the SRM can be used to effectively evaluate the likely success of roof supports and the stability condition of entries in coal mines.
