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foxl2l is a germ cell-intrinsic gatekeeper of oogenesis in zebrafish

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Zoological Research 2024年第5期45卷 1116-1130页

作者： Zhiqin Ren ding Ye Naike Su Chaofan Wang Lijia He Houpeng Wang Mudan He yonghua Sun Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture Hubei Hongshan LaboratoryInstitute of HydrobiologyInnovation Academy for Seed DesignChinese Academy of SciencesWuhanHubei 430072China School of Marine Biology and Fisheries Hainan UniversityHaikouHainan 570228China College of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijing 100049China College of Fisheries and Life Science Dalian Ocean UniversityDalianLiaoning 116023China

Zebrafish serve as a valuable model organism for studying germ cell biology and reproductive *** AB strain of zebrafish is proposed to exhibit a polygenic sex determination system,where most males initially develop juvenile ovaries before committing to male *** species with chromosomal sex determination,gonadal somatic cells are recognized as key determinants of germ cell ***,the loss of germ cells in zebrafish leads to masculinization,implying that germ cells harbor an intrinsic feminization ***,the specific signal triggering oogenesis in zebrafish remains *** the present study,we identified foxl2l as an oocyte progenitor-specific gene essential for initiating oogenesis in germ *** showed that foxl2l-knockout zebrafish bypassed the juvenile ovary stage and exclusively developed into fertile *** analysis revealed that loss of foxl2l hindered the initiation of oocyte-specific meiosis and prevented entry into oogenesis,leading to premature spermatogenesis during early gonadal ***,while mutation of the pro-male gene dmrt1 led to fertile female differentiation,simultaneous disruption of foxl2l in dmrt1 mutants completely blocked oogenesis,with a large proportion of germ cells arrested as germline stem cells,highlighting the crucial role of foxl2l in ***,this study highlights the unique function of foxl2l as a germ cell-intrinsic gatekeeper of oogenesis in zebrafish.

关键词： foxl2l dmrt1 Oogenesis Sex determination Meiosis

Endogenous biosynthesis of docosahexaenoic acid(DHA)regulates fish oocyte maturation by promoting pregnenolone production

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Zoological Research 2024年第1期45卷 176-188页

作者： Yi Li Xuehui Li ding Ye Ru Zhang Chengjie Liu Mudan He Houpeng Wang Wei Hu yonghua Sun State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyInnovation Academy for Seed DesignChinese Academy of SciencesWuhanHubei 430072China College of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijing 100049China Hubei Hongshan Laboratory WuhanHubei 430070China

Omega-3 polyunsaturated fatty acids(n-3 PUFAs),particularly docosahexaenoic acid(22:6n-3,DHA),play crucial roles in the reproductive health of vertebrates,including ***,the underlying mechanism related to this phenomenon remains largely *** this study,we employed two zebrafish genetic models,i.e.,elovl2^(-/-)mutant as an endogenous DHAdeficient model and fat1(omega-3 desaturase encoding gene)transgenic zebrafish as an endogenous DHA-rich model,to investigate the effects of DHA on oocyte maturation and *** show that the elovl2^(-/-)mutants had much lower fecundity and poorer oocyte quality than the wild-type controls,while the fat1 zebrafish had higher fecundity and better oocyte quality than wildtype *** deficiency in elovl2^(-/-)embryos led to defects in egg activation,poor microtubule stability,and reduced pregnenolone *** study revealed that DHA promoted pregnenolone synthesis by enhancing transcription of cyp11a1,which encodes the cholesterol side-chain cleavage enzyme,thereby stabilizing microtubule assembly during *** turn,the hypothalamic-pituitary-gonadal axis was enhanced by *** conclusion,using two unique genetic models,our findings demonstrate that endogenously synthesized DHA promotes oocyte maturation and quality by promoting pregnenolone production via transcriptional regulation of cyp11a1.

关键词： Docosahexaenoic acid Oocyte maturation Oocyte quality Pregnenolone Microtubule

Power supply for generating frequency-variable resonant magnetic perturbations on the J-TEXT tokamak

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Plasma Science and Technology 2018年第8期20卷 96-103页

作者： Guo XU Bo RAO yonghua ding Mao LI Da LI Ruo JIA Minxiong YAN Xinke JI Nengchao WANG Zhuo HUANG Daojing GUO Lai PENG State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhan 430074People＇s Republic of China School of Electrical and Electronic Engineering Huazhong University of Science and TechnologyWuhan 430074People＇s Republic of China

To further research the response of the tearing mode（TM） to dynamic resonant magnetic perturbation（DRMP） on the J-TEXT tokamak, a modified series resonant inverter power supply（MSRIPS） with a function of discrete variable frequency is designed for DRMP coils in this study. The MSRIPS is an AC–DC–AC converter, including a phase-controlled rectifier, an LC filter, an insulated gate bipolar transistor（IGBT） full bridge, a matching transformer, three resonant capacitors with different capacitance values, and three corresponding silicon controlled rectifier（SCR） switches. The function of discrete variable frequency is realized by switching over different resonant capacitors with corresponding SCR switches while matching the corresponding driving frequency of the IGBT full bridge. A detailed switching strategy of the SCR switch is put forward to obtain sinusoidal current waveform and realize current waveform smooth transition during frequency conversion. In addition, a resistor and thyristor bleeder is designed to protect the SCR switch from overvoltage. Manufacturing of the MSRIPS is completed, and the MSRIPS equipment can output current with an amplitude of 1.5 kA when its working frequency jumps among different frequencies. Moreover, the current waveform is sinusoidal and can smoothly transition during frequency conversion. Furthermore, the transition time when the current amplitude rises from zero to a steady state is less than 2 ms during frequency conversion. By using the MSRIPS, the expected discrete variable frequency DRMP is generated, and the phenomenon of the TM being locked to the discrete variable frequency DRMP is observed on the J-TEXT tokamak.

关键词： tearing mode J-TEXT series resonant inverter discrete variable frequency silicon controlled rectifier

Machine learning application to predict the electron temperature on the J-TEXT tokamak

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Plasma Science and Technology 2021年第8期23卷 47-52页

作者： Jiaolong DONG Jianchao LI yonghua ding Xiaoqing ZHANG Nengchao WANG Da LI Wei YAN Chengshuo SHEN Ying HE Xiehang REN Donghui XIA International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People's Republic of China Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of TechnologyWuhan 430205People's Republic of China

The reliability of diagnostic systems in tokamak plasma is of great significance for physics researches or fusion *** some diagnostics fail to detect information about the plasma status,such as electron temperature,they can also be obtained by another method:fitted by other diagnostic signals through machine *** paper herein is based on a machine learning method to predict electron temperature,in case the diagnostic systems fail to detect plasma *** fully-connected neural network,utilizing back propagation with two hidden layers,is utilized to estimate plasma electron temperature approximately on the *** input parameters consist of soft x-ray emission intensity,electron density,plasma current,loop voltage,and toroidal magnetic field,while the targets are signals of electron temperature from electron cyclotron emission and x-ray imaging crystal ***,the temperature profile is reconstructed by other diagnostic signals,and the average errors are within 5%.In addition,generalized regression neural network can also achieve this function to estimate the temperature profile with similar *** electron temperature by neural network reveals that machine learning can be used as backup means for plasma information so as to enhance the reliability of diagnostics.

关键词： neural network plasma electron temperature J-TEXT tokamak

SiO_(2)气凝胶隔热材料的制备及其导热性能研究

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功能材料 2022年第9期53卷 9122-9126页

作者：丁勇花庞玉玲郑州工业应用技术学院建筑工程学院河南新郑451100 郑州升达经贸管理学院建筑工程学院郑州451191

选择MTMS为硅源,以0.5 mol/L的草酸溶液作为酸催化剂,不同浓度(1,3,5和7 mol/L)的氨水作为碱催化剂,采用酸碱两步溶胶-凝胶法和常压干燥工艺制备出一系列不同氨水浓度的SiO_(2)气凝胶隔热材料。通过XRD、SEM、FT-IR等研究了氨水浓度对Si... 详细信息

选择MTMS为硅源,以0.5 mol/L的草酸溶液作为酸催化剂,不同浓度(1,3,5和7 mol/L)的氨水作为碱催化剂,采用酸碱两步溶胶-凝胶法和常压干燥工艺制备出一系列不同氨水浓度的SiO_(2)气凝胶隔热材料。通过XRD、SEM、FT-IR等研究了氨水浓度对SiO_(2)气凝胶晶体结构、微观形貌、物理性能和导热性能的影响。结果表明,制备的SiO_(2)气凝胶隔热材料均为无定型非晶结构,其二级粒子尺寸约为200 nm左右;氨水浓度的适量增加会提高SiO_(2)气凝胶颗粒分布的均匀性,而氨水浓度过大后,会出现团聚板结现象;随着氨水浓度的增加,SiO_(2)气凝胶的孔径变化较小,凝胶时间、孔隙率和孔体积先减少后增加,密度先升高后降低,导热系数先降低后升高。当氨水浓度为5 mol/L时,SiO_(2)气凝胶的凝胶时间最短为13.2 min,密度最大为0.14 g/cm^(3),孔隙率最小为92.34%,导热系数最低为0.021 W/(m·K),且颗粒分布均匀、形貌最佳,具有良好的隔热保温性能,在节能建筑材料方面具有广阔的应用前景。

关键词： SiO_(2)气凝胶隔热材料溶胶-凝胶法导热系数节能

The spectrum analysis of RMP coils with multiple connection modes and the design of high field side coils on J-TEXT

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Plasma Science and Technology 2022年第12期24卷 224-231页

作者： Zhengkang REN Da Li Nengchao WANG Feiyue MAO Zhuo HUANG Song ZHOU Ruo JIA Ying HE Chengshuo SHEN Abba Alhaji BALA Bo RAO yonghua ding the J-TEXT Team International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People's Republic of China College of Computer Science South-Central Minzu UniversityWuhan 430074People's Republic of China Physics Department Federal University DutseDutse 720101Nigeria

The phase difference Δξ between locked islands(2/1 and 3/1) has been found to influence the heat transport on the thermal quench during disruptions by numerical modeling [Hu Q et al *** 59,016005].To verify this experimentally,a set of resonant magnetic perturbation(RMP) coils is required to excite coupled magnetic islands with different Δξ.The spectrum analysis shows that the current RMP coils on J-TEXT can only produce sufficient 2/1 and 3/1RMP fields with a limited phase difference of Δξ∈[-75°,75°].In order to broaden the adjustable range of Δξ,a set of coils on the high field side(HFS) is proposed to generate 2/1 and 3/1 RMP fields with Δξ=180°.As a result,RMPs with adjustable Δξ∈[-180°,180°] and sufficient amplitudes could be achieved by applying the HFS coils and the low field side(LFS)*** work provides a feasible solution for flexible adjustment of the phase difference between m and m+1 RMP,which might facilitate the study of major disruptions and their control.

关键词： resonant magnetic perturbation spectrum analysis phase difference between 2/1 and 3/1 islands

Overview of runaway current suppression and dissipation on J-TEXT tokamak

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Plasma Science and Technology 2022年第12期24卷 115-125页

作者： Zhongyong CHEN Zhifang LIN Wei YAN Duwei HUANG Yunong WEI You LI Nianheng CAI Jie HU yonghua ding Yunfeng LIANG Zhonghe JIANG J-TEXT Team International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People's Republic of China School of Electrical Engineering&Automation Jiangsu Normal UniversityXuzhou 221116People's Republic of China

The main works on disruption mitigation including suppression and mitigation of runaway current on the J-TEXT tokamak are summarized in this *** strategies for the mitigation of runaway electron(RE) beams are applied in *** first strategy enables the REs to be completely suppressed by means of supersonic molecular beam injection and resonant magnetic perturbation which can enhance RE loss,magnetic energy transfer which can reduce the electric field,and secondary massive gas injection(MGI) which can increase the collisional *** the second strategy,the runaway current is allowed to form but should be dissipated or soft landed within *** is observed that the runaway current can be significantly dissipated by MGI,and the dissipation rate increases with the injected impurity particle number and eventually stabilizes at 28 MA s^(-1).The dissipation rate of the runaway current can be up to 3 MA s^(-1)by ohmic *** pellet injection has been chosen as the main disruption mitigation method,which has the capability of injecting material deeper into the plasma for higher density assimilation when compared to ***,simulation works show that the RE seeds in the plasma are strongly influenced under different phases and sizes of 2/1 mode locked islands during thermal *** robust runaway suppression and runaway current dissipation provide an important insight on the disruption mitigation for future large tokamaks.

关键词： tokamak disruption mitigation runaway electron runaway current

Recent progress of the ECRH system and initial experimental results on the J-TEXT tokamak

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Plasma Science and Technology 2022年第12期24卷 127-137页

作者： Donghui XIA Xixuan CHEN Dengfeng XU Jiangang FANG Junli ZHANG Nengchao WANG Zhoujun YANG Zhongyong CHEN yonghua ding Wei ZHENG Shaoxiang MA Zhijiang WANG Yuan PAN International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People's Republic of China

In order to broaden the range of the plasma parameters and provide experimental conditions for physical research into high-performance plasma,the development of the electron cyclotron resonance heating(ECRH) system for the J-TEXT tokamak was initiated in *** the first stage,the ECRH system operated successfully with one 105 GHz/500 kW/1 s gyrotron in *** than 400 kW electron cyclotron(EC) wave power has been injected into the plasma successfully,raising the core electron temperature to 1.5 *** 2022,another 105 GHz/500 kW/1 s gyrotron completed commissioning tests which signifies that the ECRH system could generate an EC wave power of 1 MW in *** the support of the ECRH system,various physical experiments have been carried out on *** electron thermal transport in ECRH plasmas has been *** ECRH is turned on,the electron thermal diffusivity significantly *** runaway current is elevated when a disruption occurs during ECRH *** the injected EC wave power is 400 kW,the conversion efficiency of runaway current increases from 35% to 75%.Fast electron behavior is observed in electron cyclotron current drive(ECCD) plasma by the fast electron bremsstrahlung diagnostic(FEB).The increase in the FEB intensity implies that ECCD could generate fast electrons.A successful startup with a 200 kW ECW is *** the upgrade of the ECRH system,the J-TEXT operational range could be expanded and further relevant research could be conducted.

关键词： ECRH J-TEXT tokamak electron thermal transport runaway electron current assisted start-up

Development of the pellet injection system on the J-TEXT tokamak

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Plasma Science and Technology 2022年第9期24卷 127-133页

作者： Yingzhou JIANG Zhongyong CHEN You LI Wei YAN A LUKIN I VINYAR Feng LI Xin XU Zhipeng CHEN Zhoujun YANG Nengchao WANG yonghua ding Yuan PAN the J-TEXT Team International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China PELIN LLC Saint-Petersburg 190031Russia

Pellet injection is an attractive technology for core-fueling and magnetohydrodynamic study in magnetic-conflnement fusion devices like tokamaks and *** can inject solid hydrogen/deuterium pellets into the plasma with deeper density deposition compared with other fueling methods,such as gas pufflng.A three-barrel H_(2)pellet injection system was installed on the J-TEXT tokamak and experiments were carried *** pellets are formed in three barrels cooled by a cryocooler and compressor system at around 9 K,and are 0.8 mm/1 mm diameter and 0.8 mm *** pellet is launched by helium propellant gas and injected from the lowfleld side of the *** normal range of pellet speed is 210–310 m s^(-1)for different propellant gas *** to the three-barrel structure,the number of injected pellets can be adjusted between one and *** can be launched sequentially with arbitrary time intervals,which enables flexible *** results of the experiments show that pellet fueling efflciency can reach 50%.The energy conflnement time increased by about 7.5–10 ms after pellet injection.

关键词： J-TEXT pellet injection system pellet fueling