Results 11 to 20 of about 408,955 (129)

体外受精和卵胞浆单精子注射完全受精失败的临床因素分析

open access: yesZhongshan Daxue xuebao. Yixue kexue ban, 2012
【目的】 分析体外受精(IVF)和卵胞浆内单精子注射(ICSI)治疗中完全受精失败(TFF)发生的临床原因?【方法】收集本中心2007年1月至2011年5月间辅助生殖治疗数据,分IVF组(5778例)?half-ICSI组(146例)?ICSI组(821例)和PESA-ICSI组(274例)进行?字2 检验?t-检验和Logistic回归分析等统计分析,并对部分ICSI完全受精失败卵母细胞进行免疫荧光染色和激光共聚焦显微镜观察?【结果】 IVF组和ICSI组TFF发生率分别为2.1% 和2.3%(P >
doaj   +1 more source

短时受精后提早剥离颗粒细胞对体外受精的影响

open access: yesZhongshan Daxue xuebao. Yixue kexue ban, 2016
摘 要: 【目的】 研究在人体外受精过程中提早剥除颗粒细胞对受精和发育的影响。【方法】 对本中心行短时受精(5 h)的53对夫妇纳入研究,当其精卵孵育5 h之后,将所用卵子平均分为2组(5 h组和19 h组),分别于受精5 h和19 h时剥除颗粒细胞。观察两组中同一批卵子受精情况并用荧光原位杂交(FISH)技术分析多原核胚胎中原核(PN)来源。【结果】 5 h组和19 h组两组之间的正常受精率(两原核率)、单原核率和未成熟卵率相似,差异均无统计学意义,然而多原核率在5 h组明显高于19 h组﹝(10.9
doaj   +1 more source

短时受精后早剥卵对胚胎质量及妊娠结局的影响

open access: yesZhongshan Daxue xuebao. Yixue kexue ban, 2014
摘 要: 【目的】 探讨短时受精后早期剥除颗粒细胞对体外受精胚胎质量及妊娠结局的影响。【方法】 回顾性分析2012年在本中心助孕的有早剥卵的103个IVF周期与74个ICSI周期,以ICSI组为对照,比较两组的2PN受精率、多PN受精率、可利用胚胎形成率、卵裂期优质胚胎形成率、种植率和临床妊娠率,再以IVF周期中的卵子是否进行早剥分为两组,比较早剥对IVF周期中2PN受精率、多PN受精率、可利用胚胎形成率、卵裂期优质胚胎形成率、种植率和临床妊娠率的影响。【结果】在IVF周期中共有1181枚卵子纳入研究 ...
doaj   +1 more source

常规IVF不受精周期行补救卵母细胞单精子注射 [PDF]

open access: yesZhongshan Daxue xuebao. Yixue kexue ban, 2007
【目的】探讨常规体外受精胚胎移植(in vitro fertilization and embryo transfer,IVF-ET)不受精时,应用卵母细胞单精子显微注射(intracytoplasmic sperm injection,ICSI)技术进行补救授精的临床意义。【方法】2001年8月~2005年8月,在499个常规IVF-ET周期中有25个周期完全不受精,进行补救ICSI,并与同期实施的179个正常ICSI周期进行比较。【结果】补救ICSI组与正常ICSI组比较,HCG日平均血清雌二醇水平、
李晓虹   +8 more
doaj   +1 more source

优化精液处理中的密度梯度离心法以提高受精结局的探讨 [PDF]

open access: yesZhongshan Daxue xuebao. Yixue kexue ban
目的本研究旨在改进生殖男科领域现有的精液处理方法,特别是针对双层密度梯度法中的300 ×g 20 min处理条件,以提高受精结局。方法收集2020年7月和9月以及2022年3月和5月在中山大学附属第六医院生殖医学中心进行辅助生殖助孕的1 623例患者的精液标本进行实验。预实验中,比较四种不同的双层密度梯度方法(200 ×g 10 min、200 ×g 20 min、300 ×g 10 min和300 ×g 20 min)处理后标本的精子DNA碎片率和回收率。然后,筛选出一种最优的方法作为新方法 ...
孙桂花   +3 more
doaj   +2 more sources

体外受精与胚胎移植研究进展 [PDF]

open access: yesZhongshan Daxue xuebao. Yixue kexue ban, 1997
摘 要 作者综述我院自1990年建立体外受精与胚胎移植技术应用于治疗不育的研究。目前本技术已处 于国内领先地位,技术的改进着重于如下几方面: ①改进治疗周期超排卵方案, 提高卵子受精率; ②改良选择性 减胎术,达到准确、简便、安全,减少多胎妊娠; ③应用体外受精与胚胎移植( IV F-E T)技术为卵巢早衰患者及遗 传病夫妇提供赠卵、赠胚胎治疗的方法; ④建立第2代IV F-ET技术,应用卵母细胞单精显微注射技术( ICS I)治 疗严重男性因素与不明原因不育,同时展望人工辅助破`壳 ...
庄广伦
doaj   +1 more source

Saline versus alkaline stresses in paddy soils drive divergent microbial nutrient limitations despite shared carbon constraints

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Soil salinization and alkalization often suppress microbial functional activity, triggering negative feedback loops in microbial metabolism, degrading nutrients and agricultural productivity.
Yuqi Chen, Lingying Xu, Xu Zhao
wiley   +1 more source

Improving efficiency in conservation planning by modeling species‐specific responses to threat abatement

open access: yesConservation Biology, EarlyView.
Abstract Reversing ongoing biodiversity loss requires effectively managing anthropogenic threats. Although conservation actions can mitigate these threats, prioritizing and targeting such actions remain challenging because species respond differently depending on the nature of the threats and their biological traits.
Camila Guerrero‐Pineda   +3 more
wiley   +1 more source

Observer coverage and interaction rates determine the choice between design‐based and machine learning bycatch estimators for rare species

open access: yesConservation Biology, EarlyView.
Abstract Robust estimates of the magnitude of protected species bycatch are essential for effective fisheries management and marine conservation. Existing bycatch estimation methods typically struggle to accurately and precisely estimate the bycatch of rare species as a result of the statistical assumptions necessary to overcome infrequent encounters ...
Christopher Long   +3 more
wiley   +1 more source

The shared benefits of fallen fruits: A novel mechanism stabilizing a nursery pollination mutualism between Sambucus and kateretid beetles

open access: yesPLANTS, PEOPLE, PLANET, Volume 8, Issue 6, Page 1930-1942, November 2026.
Understanding how cooperative interactions remain stable matters for biodiversity because many plants rely on specialist insects that can also impose reproductive costs. We studied the interaction between Sambucus sieboldiana and seed‐consuming Heterhelus beetles through detailed field observations and pollination experiments.
Suzu Kawashima   +3 more
wiley   +1 more source

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