This systematic review aimed to evaluate the efficacy and safety of assisted hatching （AH） performed in couples with advanced maternal age. We searched for randomized controlled trials （RCTs） in electronic databas...This systematic review aimed to evaluate the efficacy and safety of assisted hatching （AH） performed in couples with advanced maternal age. We searched for randomized controlled trials （RCTs） in electronic databases, including MEDLINE, EMBASE and CENTRAL （from inception to January 2018）; in addition, we hand-searched the reference lists of included studies and similar reviews. We included RCTs comparing AH versus no treatment （control）. The meta-analysis was performed by RevMan 5.3 software. The search retrieved 943 records and 8 RCTs were included, comprising 870 cycles （n=440 for AH, and n=430 for control）. There was no significant difference in the rates of live birth （RR 0.88, 95% CI 0.65 to 1.18, 3 RCTs, n-427,I^2=0%）, clinical pregnancy （RR 1.00, 95% CI 0.83 to 1.19, 8 RCTs, n=870, I^2=22%）, implantation （RR 1.07, 95% CI 0.83 to 1.39, 4 RCTs, n=1359, I^2=0%）, miscarriage （RR 1.13, 95% CI 0.66 to 1.94, 2 RCTs, n=116, I^2=0%） and multiple pregnancy （RR 0.89, 95% CI 0.31 to 2.52, 1 RCT, n=97,I^2=not applicable） between the treatment group and control group. No reasonable conclusions could be drawn regarding reproductive outcomes after AH in patients with advanced maternal age due to the small sample pooled in meta-analyses. Studies of high methodological quality and with adequate power are necessary to further investigate the value of AH in assisted conception of those patients.展开更多
Assisted hatching(AH)is commonly performed before trophectoderm(TE)biopsy for preimplantation genetic testing for aneuploidy(PGT-A),yet whether AH timing influences the detection of chromosomal mosaicism remains uncer...Assisted hatching(AH)is commonly performed before trophectoderm(TE)biopsy for preimplantation genetic testing for aneuploidy(PGT-A),yet whether AH timing influences the detection of chromosomal mosaicism remains uncertain.Beyond timing,procedural choices in PGT-A must balance diagnostic yield against potential harm from additional handling(e.g.,repeat TE biopsy or cryopreservation steps),as underscored by a recent systematic review and meta-analysis[1].展开更多
针对单频地基增强系统(Ground Based Augmentation System,GBAS)中电离层异常时Hatch滤波器平滑精度降低问题,系统分析了电离层延时对Hatch滤波器平滑精度的影响,提出一种改进自适应Hatch滤波算法。根据卫星信号计算码载偏离度,并利用...针对单频地基增强系统(Ground Based Augmentation System,GBAS)中电离层异常时Hatch滤波器平滑精度降低问题,系统分析了电离层延时对Hatch滤波器平滑精度的影响,提出一种改进自适应Hatch滤波算法。根据卫星信号计算码载偏离度,并利用二阶线性时不变低通滤波器抑制码载偏离度高频信号,以实现电离层异常实时检测;建立平滑后伪距误差均方根与电离层延时变化率、伪距测量噪声标准差以及平滑时间三者之间的函数模型,并由此确定出Hatch滤波器最优平滑时间。利用GBAS原理样机进行验证实验,结果表明:自适应Hatch滤波算法能够根据卫星信号电离层延时变化率确定滤波器最优平滑时间,且当电离层异常时,自适应Hatch滤波器机载位置误差最大由1.15 m减小为0.43 m,从而验证了所提算法的有效性。展开更多
In order to investigate the effect of temperature on hatching result of fertilized peacock eggs, they were hatched under conditions of varying temperature and constant temperature respectively. The result shows that t...In order to investigate the effect of temperature on hatching result of fertilized peacock eggs, they were hatched under conditions of varying temperature and constant temperature respectively. The result shows that the hatching rate in the varying temperature treatment group （Group Ⅰ） is higher than that in the constant temperature treatment group （Group Ⅱ）. It suggests that the varying temperature treatment （high temperature in the early period, medium temperature in the middle period, slightly lower temperature in the late period, and slightly higher temperature in the hulling period） is in line with the optimum temperature variation in the hatching of fertilized peacock eggs, contributing the hatching of fertilized peacock eggs.展开更多
文摘This systematic review aimed to evaluate the efficacy and safety of assisted hatching （AH） performed in couples with advanced maternal age. We searched for randomized controlled trials （RCTs） in electronic databases, including MEDLINE, EMBASE and CENTRAL （from inception to January 2018）; in addition, we hand-searched the reference lists of included studies and similar reviews. We included RCTs comparing AH versus no treatment （control）. The meta-analysis was performed by RevMan 5.3 software. The search retrieved 943 records and 8 RCTs were included, comprising 870 cycles （n=440 for AH, and n=430 for control）. There was no significant difference in the rates of live birth （RR 0.88, 95% CI 0.65 to 1.18, 3 RCTs, n-427,I^2=0%）, clinical pregnancy （RR 1.00, 95% CI 0.83 to 1.19, 8 RCTs, n=870, I^2=22%）, implantation （RR 1.07, 95% CI 0.83 to 1.39, 4 RCTs, n=1359, I^2=0%）, miscarriage （RR 1.13, 95% CI 0.66 to 1.94, 2 RCTs, n=116, I^2=0%） and multiple pregnancy （RR 0.89, 95% CI 0.31 to 2.52, 1 RCT, n=97,I^2=not applicable） between the treatment group and control group. No reasonable conclusions could be drawn regarding reproductive outcomes after AH in patients with advanced maternal age due to the small sample pooled in meta-analyses. Studies of high methodological quality and with adequate power are necessary to further investigate the value of AH in assisted conception of those patients.
文摘Assisted hatching(AH)is commonly performed before trophectoderm(TE)biopsy for preimplantation genetic testing for aneuploidy(PGT-A),yet whether AH timing influences the detection of chromosomal mosaicism remains uncertain.Beyond timing,procedural choices in PGT-A must balance diagnostic yield against potential harm from additional handling(e.g.,repeat TE biopsy or cryopreservation steps),as underscored by a recent systematic review and meta-analysis[1].
基金Supported by Scientific and Technological Development General Program of Beijing Municipal Education Commission(KM201412448004)~~
文摘In order to investigate the effect of temperature on hatching result of fertilized peacock eggs, they were hatched under conditions of varying temperature and constant temperature respectively. The result shows that the hatching rate in the varying temperature treatment group （Group Ⅰ） is higher than that in the constant temperature treatment group （Group Ⅱ）. It suggests that the varying temperature treatment （high temperature in the early period, medium temperature in the middle period, slightly lower temperature in the late period, and slightly higher temperature in the hulling period） is in line with the optimum temperature variation in the hatching of fertilized peacock eggs, contributing the hatching of fertilized peacock eggs.
