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大块金属玻璃 2

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Effect of repeated gonadotropin stimulation on ovarian reserves and proliferation of ovarian surface epithelium in mice

Linlin LIANG, Bei XU, Guijin ZHU

《医学前沿（英文）》 2009年第3卷第2期页码 220-226 doi: 10.1007/s11684-009-0037-2

摘要： This study aimed to evaluate the effect of repeated ovarian stimulation (OS) on the ovarian follicular population and morphology in female mice and its influence on the embryo’s developmental ability, and the profile of the ovarian surface epithelium (OSE). A total of 75 mice were enrolled in this experiment and randomly assigned into three groups: repeated ovarian stimulated group [ =25; receiving 5 IU pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotropin (hCG) at 6 day intervals for 5 cycles]; single ovarian stimulated group ( =25; receiving 5 IU PMSG and hCG for 1 cycle), and control group ( =25; without additional treatment). The follicle number at various stages and the morphologies were recorded respectively in the three groups. The harvested oocytes or embryos, cleavage rate, good quality embryo rate, and blastocyst production rate were counted and calculated, and the proliferations of ovarian surface epithelium were evaluated respectively. In the three groups, the single ovarian stimulation treatment significantly increased the mean number of ovarian oocytes or embryos (39.25±10.77 one-cell embryos/female); on the other hand, repeated gonadotropin stimulation obtained the lowest mean number (5.15± 2.81 eggs/female, <0.01). Repeated ovarian stimulation also tended to decrease normal follicles of primary follicles (66.67%) and secondary follicles (72.86%), and got the lowest cleavage rate (67.47%), lowest good quality embryo rate (2.41%), and lowest blastocyst production rate (0). The OSE cells adjacent to the antral follicles and corpus luteum (CL) in the repeated ovarian stimulated group (81.8%) had a significantly higher proliferation rate than the other groups. The proliferation rate of the OSE in the single ovarian stimulated group (56.4%) was significantly higher than that in the control group (37.5%) ( <0.01). In conclusion, single ovarian stimulation may produce more oocytes/embryos. However, repeated gonadotropin stimulation may have a negative effect on the ovarian follicular quality, the number of mature retrieved oocytes, and the embryo quality, even increasing the chance of ovarian cancer.

关键词： gonadotropin-releasing hormone ovarian reserve embryo developmental ability ovarian surface epithelium

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Free radical scavenging window of infertile patients with polycystic ovary syndrome: correlation with embryo

null

《医学前沿（英文）》 2017年第11卷第2期页码 247-252 doi: 10.1007/s11684-017-0519-6

摘要：

The activity of free radicals in follicular fluid was related to ovarian responsiveness, in vitro fertilization (IVF), and embryo transfer success rate. However, studies analyzing the relationship between the free radical scavenging capacity and embryo quality of infertile women with polycystic ovarian syndrome (PCOS) were lacking. The aim of this study was to evaluate the relationship between the free radical scavenging window of women with PCOS and their embryo quality. The free radical scavenging capacity of follicular fluid from women with PCOS was determined by a,a-diphenyl-b-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) assay, superoxide radical, and reactive oxygen species (ROS) assay. In the DPPH and ROS assays, the follicular fluid from grades I and II embryos was significantly higher than the follicular fluid from grades III and IV embryos. The lower control limit of DPPH radical scavenging capacity and upper control limit of ROS level were 13.2% and 109.0 cps, respectively. The calculated lower control limit and upper control limit were further confirmed in the follicular fluid of embryos of all grades. These cut-off values of free radical scavenging activity of follicular fluid could assist embryologists in choosing the development of embryos in PCOS patients undergoing IVF.

关键词： in vitro fertilization PCOS free radical embryo quality

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Current techniques for assessing developmental neurotoxicity of pesticides

GAO Yu, TIAN Ying, SHEN Xiaoming

《医学前沿（英文）》 2008年第2卷第4期页码 337-343 doi: 10.1007/s11684-008-0064-4

摘要： Organophosphates (OPs) and Pyrethroids (PRY) have been widely used in agriculture and in the home as broad spectrum insecticides, but may produce considerable risk to human health, especially to children. Children are more susceptible to environmental exposure, and concern about the neurotoxic effects of pesticide exposure on children is increasing. There is a need for better understanding of the potential developmental neurotoxicity of pesticides. Techniques for assessing developmental neurotoxicity of pesticides will continue to be developed, rendering a need for flexibility of testing paradigms. Current techniques used in evaluating the developmental neurotoxicity of OPs and PRY are presented in this review. These include: (1) techniques (PC12 cells, C6 cells and other cell models); (2) Non-mammalian models (sea urchins, zebrafish and other non-mammalian models); and (3) mammalian models (morphological techniques, neurobehavioral assessments and biomarkers).

关键词： paradigms Pyrethroids non-mammalian susceptible morphological

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reduces IgE binding ability of allergenic egg white proteins

Sen LI, Marina OFFENGENDEN, Michael G. GÄNZLE, Jianping WU

《农业科学与工程前沿（英文）》 2018年第5卷第3期页码 373-381 doi: 10.15302/J-FASE-2018210

摘要：

Egg white proteins are one of the major allergens. The objective of this study was to investigate the effect of Aspergillus oryzae cultivation on IgE binding ability of egg white proteins. Effect of A. oryzae on egg white proteins was determined using ninhydrin method, SDS-PAGE, ELISA, fluorescence FITC labeling, MALDI-TOF-MS and LC-MS/MS analysis. Adding mycelium of A. oryzae ATCC 1011 and 16868 substantially reduced the IgE binding ability of acidified egg white after 24 h incubation. The binding capacity of egg white proteins to IgE in plasma from four egg allergy patients was almost completely lost after incubation with mycelium of ATCC 16868. Results from SDS-PAGE, free amino acid analysis, MALDI-TOF-MS and LC-MS/MS indicated that there was no substantial protein degradation during incubation. Therefore, the reduction of IgE binding ability of egg white proteins during A. oryzae treatment was probably due to a loss of ~1700 Da mass including a fragment of the ovomucoid N terminus.

关键词： Aspergillus oryzae egg allergy egg white proteins IgE-binding ability ovomucoid

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HIGH QUALITY DEVELOPMENTAL APPROACH FOR SOIL AND WATER CONSERVATION AND ECOLOGICAL PROTECTION ON THE

《农业科学与工程前沿（英文）》 2021年第8卷第4期页码 501-511 doi: 10.15302/J-FASE-2021425

摘要：

The Loess Plateau is the core area in the Yellow River basin for implementing environmental protection and high-quality development strategies. A series of ecological projects has implemented aimed at soil and water conservation and ecological management on the Loess Plateau over the past 70 years. The effects of the ecological projects are apparent mainly through a marked increase in vegetation cover, controlled soil erosion and reduced flow of sediment into the Yellow River, continual optimization of the industrial structure and increased production from arable land, poverty alleviation and greater prosperity, and optimal allocation of space for biological organisms. Major problems have also been analyzed in ecological management including the fragile ecosystem of the region, maintaining the stability of vegetation, lower agricultural productivity and continued risk from natural disasters. Some suitable schemes and models have been developed for the coordinated development of the region through research and demonstration, striking the optimum balance between rural industry and ecology, and increased regional capacity to supply high-quality ecological products. Countermeasures to address the problems are suggested to guide ecological management and high-quality development in the future.

关键词： ecological management high quality development industrial structure soil erosion soil and water conservation Loess Plateau

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Propensity score-matched study and meta-analysis of cumulative outcomes of day 2/3 versus day 5/6 embryo

null

《医学前沿（英文）》 2017年第11卷第4期页码 563-569 doi: 10.1007/s11684-017-0535-6

摘要：

The superiority of the cumulative outcomes of day 5/6 embryo transfer to those of day 2/3 embryo transfer in infertile couples has been debated. This retrospective study included data collected from 1051 patients from July 2011 to June 2014. Multiple maternal baseline covariates were subjected to propensity score matching analysis, and each day 5/6 group woman was matched to one day 2/3 group woman. A systematic meta-analysis was conducted to validate the results. After matching was completed, 217 patients on the day 2/3 group were matched with those on the day 5/6 group, and no significant differences in the baseline characteristics were observed between the two groups. The cumulative pregnancy rate (57.14% vs. 53.46%, OR 1.16, 95% CI 0.79–1.70) and cumulative live birth rate (53.00% vs. 49.77%, OR 1.14, 95% CI 0.78–1.66) of day 5/6 embryo transfers were higher than those of day 2/3 embryo transfers, but this difference was not significant. The mean cycles per live birth and mean days per live birth in the day 5/6 group were significantly lower than those in the day 2/3 group. This study demonstrated that day 5/6 embryo transfer is a more cost-effective and time-efficient policy than day 2/3 embryo transfer to produce a live baby.

关键词： blastocyst embryo transfer cumulative pregnancy rate cumulative live birth rate IVF

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Embryo-mediated genome editing for accelerated genetic improvement of livestock

Zachariah MCLEAN, Björn OBACK, Götz LAIBLE

《农业科学与工程前沿（英文）》 2020年第7卷第2期页码 148-160 doi: 10.15302/J-FASE-2019305

摘要：

Selecting beneficial DNA variants is the main goal of animal breeding. However, this process is inherently inefficient because each animal only carries a fraction of all desirable variants. Genome editing technology with its ability to directly introduce beneficial sequence variants offers new opportunities to modernize animal breeding by overcoming this biological limitation and accelerating genetic gains. To realize rapid genetic gain, precise edits need to be introduced into genomically-selected embryos, which minimizes the genetic lag. However, embryo-mediated precision editing by homology-directed repair (HDR) mechanisms is currently an inefficient process that often produces mosaic embryos and greatly limits the numbers of available edited embryos. This review provides a summary of genome editing in bovine embryos and proposes an embryo-mediated accelerated breeding scheme that overcomes the present efficiency limitations of HDR editing in bovine embryos. It integrates embryo-based genomic selection with precise multi-editing and uses embryonic cloning with elite edited blastomeres or embryonic pluripotent stem cells to resolve mosaicism, enable multiplex editing and multiply rare elite genotypes. Such a breeding strategy would enable a more targeted, accelerated approach for livestock improvement that allows stacking of beneficial variants, even including novel traits from outside the breeding population, in the most recent elite genetic background, essentially within a single generation.

关键词： animal breeding cattle cloning CRISPR/Cas9 cytoplasmic injection embryo genome editing germline chimaeras HDR livestock improvement TALENs

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加速胚胎移植技术产业化促进我国养牛业发展

郭志勤

《中国工程科学》 2000年第2卷第3期页码 12-17

摘要：

从我国养牛业的现状和存在的主要问题，指出养牛业需要大力发展，当前必须大量引种和繁殖种牛。而胚胎移植是引种的一种最好手段，具有方法简便、成本低、缩短改良时间、减少疾病传播等优点。同时，进一步分析了我国胚胎移植技术的研究概况，阐明了胚胎移植的主要技术关键及产业化的必要性和可能性。并根据我国养牛业的现状，提出奶牛、肉牛业应用胚胎移植技术的措施与办法。

关键词：胚胎移植产业化养牛业

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水产养殖动物营养与饲料工程发展战略研究

解绶启,张文兵,韩冬,麦康森

《中国工程科学》 2016年第18卷第3期页码 29-36 doi: 10.15302/J-SSCAE-2016.03.005

摘要：

本文综述了我国水产养殖动物营养学研究和饲料工程方面近期的研究，分析了产业发展的问题，探讨了下一步的政策措施。可以发现，过去10多年里，水产动物营养与饲料的发展在营养素需求、动物的摄食与投喂、仔稚鱼饲料、亲本营养、添加剂等方面取得了重要的进展，但仍然存在饵料系数高、环境排放大、饲料成本高、效益不稳定等问题。下一步的研究应该以“安全高效，节约环保”为目标，引入生态学和现代组学理念，开展水产动物营养代谢的分子机理、动物的营养需要与精准饲料配方技术、饲料质量控制与加工工艺、精准投喂技术、品质调控技术等方面的研究，同时在政策上应该扩大学科交流、实行长期稳定支持等。

关键词：水产养殖动物营养饲料发展策略

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Filtration ability of hollow fiber membrane for production of magnesium ammonium phosphate crystals by

H. Watamura, H. Marukawa, I. Hirasawa

《化学科学与工程前沿（英文）》 2013年第7卷第1期页码 55-59 doi: 10.1007/s11705-013-1312-y

摘要： Relationship between magnesium ammonium phosphate (MAP) crystal properties and the filtration ability of hollow fiber membrane (HFM) were investigated. Phosphorus recovery process by crystallization has a problem that it produces a large amount of fine crystals. So improvement of the crystallization process by combining with filtration was discussed. MAP crystals were obtained by batch reaction crystallization and the filtration characteristics were investigated. The filtration was evaluated by the specific filtration resistance ( ) on HFM. Filtered slurry was prepared with each suspension density and crystal size distribution. The solution was filtered at constant pressure of 0.02 MPa and the filtration time on each filtrated volume was recorded. As a result, decreases exponentially with suspension density increasing from 0.25 g/L to 0.5 g/L and decreases moderately with suspension density increasing from 0.5 g/L to 1.5 g/L. of large crystals decreases exponentially at less suspension density than of small crystals does. Also, increases as the ratio of the fractured crystals increases.

关键词： membrane separation crystallization MAP

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一类弱非线性波浪数值模型及其适用性分析

刘忠波,唐军

《中国工程科学》 2010年第12卷第9期页码 96-100

摘要：

研究了一类含弱非线性的改进型Boussinesq水波方程，在非交错网格下，利用有限差分法建立了混合四阶Adams-Bashforth-Moulton的预报校正格式的波浪数值模型。在数值模型中，关于空间一阶导数差分格式采用四阶精度、二阶导数差分格式采用二阶精度。针对波浪的一维、二维传播变形问题进行了数值计算，并通过与相关实验结果对比分析考察了该数值模型的适用性。

关键词：数值模型适用性波浪

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优化输水方式提高三峡船闸通过能力措施研究

曹光荣,胡亚安,高雄

《中国工程科学》 2007年第9卷第12期页码 75-80

摘要：探讨了三峡船闸四级运行方式下二闸首作为首级运行时一闸室水体波动特性；阐述了波动形成的机理，分析了二闸首阀门运行方式对一闸室波动的影响；提出了满足一闸室待闸安全要求的阀门开启方式；通过实船试验检验了一闸室待闸船舶停泊条件，总结了一闸室待闸调度方式。运行实践表明，三峡船闸完建期实行四级运行方式下，将下行船舶由靠船墩移至一闸室满闸室待闸，可提高船闸日均通过闸次近3个，通航效益明显。

关键词：三峡船闸；输水方式；水流条件；通过能力

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Factors affecting early embryonic development in cattle: relevance for bovine cloning

Yanna DANG, Kun ZHANG

《农业科学与工程前沿（英文）》 2019年第6卷第1期页码 33-41 doi: 10.15302/J-FASE-2018228

摘要：

Female infertility represents a major challenge for improving the production efficiency in the dairy industry. Historically, fertility has declined whereas milk yield has increased tremendously due to intensive genetic selection. evidence reveals about 60% pregnancy loss takes place during the first month following fertilization. Meanwhile, early embryo development is significant for somatic cell nuclear transfer in cattle as a large proportion of cloned embryos fail to develop beyond peri-implantation stage. Oocyte quality is of utmost importance for the early embryo to develop to term for both fertilized and cloned embryos. Epigenetic reprogramming is a key process occurring after fertilization and critical roles of epigenetic modifiers during preimplantation development are now clear. Incomplete epigenetic reprogramming is believed to be a major limitation to cloning efficiency. Treatment of cloned embryos with epigenetic modifying drugs (e.g., Trichostatin A) could greatly improve cloning efficiency in both mice and cattle. Recently, the rapid progress in high-throughput sequencing technologies has enabled detailed deciphering of the molecular mechanisms underlying these events. The robust efficiency of genomic editing tools also presents an alternative approach to the functional annotation of genes critical to early development.

关键词： bovine cloning embryo development somatic cell nuclear transfer X-inactive specific transcript

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3,4-ethylenedioxythiophene)-overoxidized polypyrrole composite films with enhanced electrocatalytic ability

《化学科学与工程前沿（英文）》 2023年第17卷第6期页码 735-748 doi: 10.1007/s11705-022-2262-z

摘要： In this study, a simple and effective method was proposed to improve the electrocatalytic ability of overoxidized poly(3,4-ethylenedioxythiophene)-overoxidized polypyrrole composite films modified on glassy carbon electrode for rutin and luteolin determination. The composite electrode was prepared by cyclic voltammetry copolymerization with LiClO₄-water as the supporting electrolyte. The peak current of rutin and luteolin on the composite electrode gradually decreased or even disappeared with the increase in the positive potential limit. After incubation in NaOH–ethanol solution with a volume ratio of 1:1, the composite electrodes prepared at positive potential limit greater than 1.5 V exhibited enhanced differential pulse voltammetry peak currents, reduced charge transfer resistance, larger effective specific surface area and higher electron transfer rate constant. The composite electrode prepared in the potential range of 0–1.7 V showed optimal electrocatalytic performance. The X-ray photoelectron spectroscopy results indicated that the content of –SO₂/–SO and –C=N– groups in the composite film increased significantly after incubation. Further, the Raman spectra and Fourier transform infrared spectra revealed that the thiophene ring structure changed from benzene-type to quinone-type, and the quinone-type pyrrole ring was formed. The electrocatalytic mechanism of the composite film was proposed based on the experimental results and further verified by Density Functional Theory calculation.

关键词： overoxidized poly(3 4-ethylenedioxythiophene)-overoxidized polypyrrole rutin luteolin incubation electrocatalytic mechanism

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Bisphenol-A epoxy resin reinforced and toughened by hyperbranched epoxy resin

ZHANG Daohong, JIA Demin, HUANG Xianbo

《化学科学与工程前沿（英文）》 2007年第1卷第4期页码 349-354 doi: 10.1007/s11705-007-0063-z

摘要： The study on toughening and reinforcing of bisphenol-A epoxy resin is one of important developmental direction in the field. This paper reports a one-pot synthesis of aromatic polyester hyperbranched epoxy resin HTDE-2, an effect of HTDE-2 content on the mechanical and thermal performance of the bisphenol-A (E51)/HTDE-2 hybrid resin in detail. Fourier transform infrared (FT-IR) spectrometer, scanning electronic microscopy (SEM), differential scanning calo ri metry (DSC), thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMA) and molecular simula tion technology are used to study the structure of HTDE-2, performance and toughening and reinforcing mechanism of the HTDE-2/E51 hybrid resin. It has been shown that the content of HTDE-2 has an important effect on the performance of the hybrid resin, and the performance of the HTDE-2/E51 blends has maximum with the increase in HTDE-2 content. The impact strength and fracture toughness of the hybrid resin with 9 wt-% HTDE-2 are almost 3.088 and 1.749 times of E51 performance respectively, furthermore, the tensile and flexural strength can also be enhanced about 20.7% and 14.2%, respectively. The glass transition temperature and thermal degradation temperature, however, are found to decrease to some extent.

关键词： thermogravimetric analysis developmental direction flexural strength HTDE-2/E51 technology