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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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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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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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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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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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Reproductive toxicity study with a novel deoxyguanosine analogue (Metacavir) in pregnant SD rats

null

《医学前沿（英文）》 2015年 第9卷 第1期   页码 82-89 doi: 10.1007/s11684-015-0376-0

摘要：

Our preliminary studies demonstrated that Metacavir has potential to become a new anti-HBV agent. The main targets of the toxic effects of Metacavir, in rhesus monkeys, were gastrointestinal tracts, liver, blood, and kidneys, which were not related to mitochondrial effects. In this study, the maternal toxicity, embryo-fetal developmental toxicity and teratogenicity were studied in pregnant Sprague-Dawley rats after intragastric administration of Metacavir (200, 100, 50, 0 mg/kg body weight) during the first 6–15 days of pregnancy. Slower weight gain was observed in 5 out of 21 rats subjected to a 200 mg/kg dose, as well as 2 out of 20 subjected to a 100 mg/kg dose. Compared with the solvent control group, the calibration weight gain in the 200 mg/kg and 100 mg/kg dosage groups respectively, during first 6–20 pregnant days were significantly different (P<0.01, P<0.05). Significant dose related adverse effects to other reproductive parameters were not seen in F0 and F1, but the number of stillbirths in high dose group showed notably difference compared with the control group (P<0.05), while the litter incidence showed no difference. No Metacavir-associated pathological changes were observed. The present research indicated that at a dose of 200 mg/(kg·d) (i.e., 40 times the effective dose in rats), Metacavir shows some maternal toxicity to SD rats. The embryotoxicity in the 200 mg/kg group encompass decreased fetal body weight, and higher fetal mortality rates, compared with the control group. However, the litter incidence showed no statistical difference. All the treated rats displayed normal bone development, no teratogenicity and without adverse effects on fetal development, thus indicating that below a dose of 200 mg/(kg·d) there is no teratogenic side effects.

关键词： deoxyguanosine analogue     Metacavir     pregnancy     maternal toxicity     embryo toxicity     teratogenicity    

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Augmentation of natural convective heat transfer by acoustic cavitation

Jun CAI, Xiulan HUAI, Shiqiang LIANG, Xunfeng LI,

《能源前沿（英文）》 2010年 第4卷 第3期   页码 313-318 doi: 10.1007/s11708-009-0064-3

摘要： An experimental study was conducted to investigate the effects of acoustic cavitation on natural convective heat transfer from a horizontal circular tube. The experimental results indicated that heat transfer could be enhanced by acoustic cavitation and had the best effect when the head of the ultrasonic transducer was over the midpoint of the circular tube, and the distance between the head and the tube equaled 15 mm. The augmentation at low heat flux was better than that in the case of high heat flux. Based on experimental results, the correlation formula of Nusselt number for water was obtained.

关键词： heat transfer enhancement     augmentation     acoustic cavitation     acoustic streaming     convective heat transfer    

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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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Effects of DNA damage on oocyte meiotic maturation and early embryonic development

Shen YIN,Junyu MA,Wei SHEN

《农业科学与工程前沿（英文）》 2014年 第1卷 第3期   页码 185-190 doi: 10.15302/J-FASE-2014035

摘要： DNA damage is one of the most common threats to meiotic cells. It has the potential to induce infertility and genetic abnormalities that may be passed to the embryo. Here, we reviewed exogenous factors which could induce DNA damage. Specially, we addressed the different effects of DNA damage on mouse oocytes and embryonic development. Complex DNA damage, double-strand breaks, represents a more difficult repair process and involves various repair pathways. Understanding the mechanisms involved in DNA damage responses may improve therapeutic strategies for ovarian cancer and fertility preservation.

关键词： DNA damage     double-strand breaks (DSBs)     oocyte     embryo    

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Experimental study of heat transfer coefficient with rectangular baffle fin of solar air heater

Foued CHABANE,Nesrine HATRAF,Noureddine MOUMMI

《能源前沿（英文）》 2014年 第8卷 第2期   页码 160-172 doi: 10.1007/s11708-014-0321-y

摘要： This paper presents an experimental analysis of a single pass solar air collector with, and without using baffle fin. The heat transfer coefficient between the absorber plate and air can be considerably increased by using artificial roughness on the bottom plate and under the absorber plate of a solar air heater duct. An experimental study has been conducted to investigate the effect of roughness and operating parameters on heat transfer. The investigation has covered the range of Reynolds number from 1259 to 2517 depending on types of the configuration of the solar collectors. Based on the experimental data, values of Nusselt number have been determined for different values of configurations and operating parameters. To determine the enhancement in heat transfer and increment in thermal efficiency, the values of Nusselt have been compared with those of smooth duct under similar flow conditions.

关键词： Nusselt number     flow rate     heat transfer     heat transfer coefficient     thermal efficiency     forced convection    

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Effect of heat transfer space non-uniformity of combustion chamber components on in-cylinder heat transfer

Jizu LV, Minli BAI, Long ZHOU, Jian ZHOU,

《能源前沿（英文）》 2010年 第4卷 第3期   页码 392-401 doi: 10.1007/s11708-009-0066-1

摘要： Combustion chamber components (cylinder head-cylinder liner-piston assembly-oil film) were treated as a coupled body. Based on the three-dimensional numerical simulation of the heat transfer of the coupled body, a coupled three-dimensional calculation model for the in-cylinder working process and the combustion chamber components was built with domain decomposition and boundary coupling method, which adopts the coupled three-dimensional simulation of in-cylinder working process and the combustion chamber components. The model was applied in the investigation of the influence of space non-uniformity in heat transfer among combustion chamber components on in-cylinder heat transfer. The results show that the effect of wall temperature space non-uniform distribution of combustion chamber components on heat transfer happens mainly at the end of the compression stroke and expansion stroke. Therefore, it can be concluded that wall temperature space non-uniform distribution of combustion chamber components would influence heat transfer during the intake and exhaust stroke obviously.

关键词： heat transfer     space non-uniformity     soot emission     in-cylinder     diesel    

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Heat transfer coefficient of wheel rim of large capacity steam turbines

SHI Jinyuan, DENG Zhicheng, YANG Yu, JUN Ganwen

《能源前沿（英文）》 2008年 第2卷 第1期   页码 20-24 doi: 10.1007/s11708-008-0015-4

摘要： A way of calculating the overall equivalent heat transfer coefficient of wheel rims of large capacity steam turbines is presented. The method and formula to calculate the mean forced convection heat-transfer coefficient of the surface of the blade and for the bottom wall of the blade passage, are introduced. The heat transmission from the blade to the rim was simplified by analogy to heat transmission in the fins. A fin heat transfer model was then used to calculate the equivalent heat transfer coefficient of the blade passage. The overall equivalent heat transfer coefficient of the wheel rim was then calculated using a cylindrical surface model. A practical calculation example was presented. The proposed method helps determine the heat transfer boundary conditions in finite element analyses of temperature and thermal stress fields of steam turbine rotors.

关键词： convection heat-transfer     capacity     heat-transfer coefficient     bottom     transmission    

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Review of the LNG intermediate fluid vaporizer and its heat transfer characteristics

《能源前沿（英文）》 2022年 第16卷 第3期   页码 429-444 doi: 10.1007/s11708-021-0747-y

摘要： The intermediate fluid vaporizer (IFV), different from other liquefied natural gas (LNG) vaporizers, has many advantages and has shown a great potential for future applications. In this present paper, studies of IFV and its heat transfer characteristics in the LNG vaporization unit E2 are systematically reviewed. The research methods involved include theoretical analysis, experimental investigation, numerical simulation, and process simulation. First, relevant studies on the overall calculation and system design of IFV are summarized, including the structural innovation design, the thermal calculation model, and the selection of different intermediate fluids. Moreover, studies on the fluid flow and heat transfer behaviors of the supercritical LNG inside the tubes and the condensation heat transfer of the intermediate fluid outside the tubes are summarized. In the thermal calculations of the IFV, the selections of the existing heat transfer correlations about the intermediate fluids are inconsistent in different studies, and there lacks the accuracy evaluation of those correlations or comparison with experimental data. Furthermore, corresponding experiments or numerical simulations on the cryogenic condensation heat transfer outside the tubes in the IFV need to be further improved, compared to those in the refrigeration and air-conditioning temperature range. Therefore, suggestions for further studies of IFV are provided as well.

关键词： intermediate fluid vaporizer     design of structure and intermediate fluid     condensation heat transfer    

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Improving hole transfer of boron nitride quantum dots modified PDI for efficient photodegradation

《化学科学与工程前沿（英文）》 2023年 第17卷 第11期   页码 1718-1727 doi: 10.1007/s11705-023-2319-7

摘要： In recent years, organic photocatalyst under visible-light absorption has shown significant potential for solving environmental problems. However, it is still a great challenge for constructing a highly active organic photocatalyst due to the low separation efficiency of photogenerated carriers. Herein, an effective and robust photocatalyst perylene-3,4,9,10-tetracarboxylic diamide/boron nitride quantum dots (PDI/BNQDs), consisting of self-assemble PDI with π–π stacking structure and BNQDs, has been constructed and researched under visible light irradiation. The PDI/BNQDs composite gradually increases organic pollutant photodegradation with the loading amount of BNQDs. With 10 mL of BNQDs solution added (PDI/BNQDs-10), the organic pollutant photodegradation performance reaches a maximum, about 6.16 times higher with methylene blue and 1.68 times higher with ciprofloxacin than that of pure PDI supramolecular. The enhancement is attributed to improved separation of photogenerated carriers from self-assembled PDI by BNQDs due to their preeminent ability to extract holes. This work is significant for the supplement of PDI supramolecular composite materials. We believe that this photocatalytic design is capable of expanding organic semiconductors’ potential for their applications in photocatalysis.

关键词： PDI     boron nitride     quantum dots     photocatalysis     hole transfer    

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Cryopreservation of farm animal gametes and embryos: recent updates and progress

Zhengyuan HUANG, Lei GAO, Yunpeng HOU, Shien ZHU, Xiangwei FU

《农业科学与工程前沿（英文）》 2019年 第6卷 第1期   页码 42-53 doi: 10.15302/J-FASE-2018231

摘要：

Cryopreservation has undergone tremendous advances and is widely used in animal production based on decades of study of cellular permeability, freezability and empirical generalization. Several improvement are particularly important: the cryopreservation protocol has been continuously refined over the years to achieve greater reproductive performance; cryoprotective agents are more effective and less toxic than previously; there has been significant innovation in advanced cryopreservation systems and carriers. Despite this, there are still problems that urgently require practical solutions, such as remedies for cryodamage and encouraging the use of frozen–thawed porcine sperm in pig production.

关键词： vitrification     gametes     embryo     animal production     cryoprotective agent     freezability    

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标题 作者 时间 类型 操作

加速胚胎移植技术产业化促进我国养牛业发展

郭志勤

期刊论文

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

null

期刊论文

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

Yanna DANG, Kun ZHANG

期刊论文

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

null

期刊论文

Embryo-mediated genome editing for accelerated genetic improvement of livestock

Zachariah MCLEAN, Björn OBACK, Götz LAIBLE

期刊论文

Reproductive toxicity study with a novel deoxyguanosine analogue (Metacavir) in pregnant SD rats

null

期刊论文

Augmentation of natural convective heat transfer by acoustic cavitation

Jun CAI, Xiulan HUAI, Shiqiang LIANG, Xunfeng LI,

期刊论文

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

Linlin LIANG, Bei XU, Guijin ZHU

期刊论文

Effects of DNA damage on oocyte meiotic maturation and early embryonic development

Shen YIN,Junyu MA,Wei SHEN

期刊论文

Experimental study of heat transfer coefficient with rectangular baffle fin of solar air heater

Foued CHABANE,Nesrine HATRAF,Noureddine MOUMMI

期刊论文

Effect of heat transfer space non-uniformity of combustion chamber components on in-cylinder heat transfer

Jizu LV, Minli BAI, Long ZHOU, Jian ZHOU,

期刊论文

Heat transfer coefficient of wheel rim of large capacity steam turbines

SHI Jinyuan, DENG Zhicheng, YANG Yu, JUN Ganwen

期刊论文

Review of the LNG intermediate fluid vaporizer and its heat transfer characteristics

期刊论文

Improving hole transfer of boron nitride quantum dots modified PDI for efficient photodegradation

期刊论文

Cryopreservation of farm animal gametes and embryos: recent updates and progress

Zhengyuan HUANG, Lei GAO, Yunpeng HOU, Shien ZHU, Xiangwei FU

期刊论文