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Reconstitution of Gametogenesis In Vitro:Meiosis Is the Biggest Obstacle

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Journal of Genetics and Genomics 2014年第3期41卷 87-95页

作者： yuan-chao Sun Shun-Feng cheng Rui Sun Yong Zhao Wei Shen Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong Qingdao Agricultural University National Laboratory for Physical Sciences at Microscale School of Life SciencesUniversity of Science and Technology of China

Germ-line cells are responsible for transmitting genetic and epigenetic information across generations, and ensuring the creation of new individuals from one generation to the next. Gametogenesis process requires several rigorous steps, including primordial germ cell （PGC） specification, proliferation, migration to the gonadal ridges and differentiation into mature gametes such as sperms and oocytes. But this process is not clearly explored because a small number of PGCs are deeply embedded in the developing embryo. In the attempt to establish an in vitro model for understanding gametogenesis process well, several groups have made considerable progress in differen- tiating embryonic stem cells （ESCs） and adult stem cells （ASCs） into germ-like cells over the past ten years. These stem cell-derived germ cells appear to he capable of undergoing meiosis and generating both male and female gametes. But most of gametes turn out to be not fully functional due to their abnormal meiosis process compared to endogenous germ cells. Therefore, a robust system of differentiating stem cells into germ cells would enable us to investigate the genetic, epigenetic and environmental factors associated with germ cell development. Here, we review the stem cell-derived germ cell development, and discuss the potential and challenges in the differentiation of functional germ cells from stem cells.

关键词： Stem cells Germ cells Gametogenesis Differentiation Meiosis

Late Mesozoic Ore-forming Events in the Ningwu Ore District, Middle-Lower Yangtze River Polymetallic Ore Belt, East China: Evidence from Zircon U-Pb Geochronology and Hf Isotopic Compositions of the Granodioritic Stocks

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Acta Geologica Sinica(English Edition) 2012年第3期86卷 719-736页

作者： DUAN chao LI Yanhe HOU Kejun yuan Shunda LIU Jialin ZHANG cheng State Key laboratory of Geological Processes and Mineral Resources School of the Earth Sciences and Resources China University of Geosciences Beijing 100083 China MLR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 100037 China

Late Mesozoic volcanic-subvolcanic rocks and related iron deposits, known as porphyry iron deposits in China, are widespread in the Ningwu ore district （Cretaceous basin） of the middle-lower Yangtze River polymetallic ore belt, East China. Two types of Late Mesozoic magmatic rocks are exposed： one is dioritic rocks closely related to iron mineralization as the hosted rock, and the other one is granodioritic （-granitic） rocks that cut the ore bodies. To understand the age of the iron mineralization and the ore-forming event, detailed zircon U-Pb dating and Hf isotope measurement were performed on granodioritic stocks in the Washan, Gaocun-Nanshan, Dongshan and Heshangqiao iron deposits in the basin. Four emplacement and crystallization （typically for zircons） ages of granodioritic rocks were measured as 126.1±0.5 Ma, 126.8±0.5 Ma, 127.3±0.5 Ma and 126.3±0.4 Ma, respectively in these four deposits, with the LA-MC-ICP-MS zircon U-Pb method. Based on the above results combined with previous dating, it is inferred that the iron deposits in the Ningwu Cretaceous basin occurred in a very short period of 131-127 Ma. In situ zircon Hf compositions of εHf（t） of the granodiorite are mainly from -3 to -8 and their corresponding 176Hf/177Hf ratio are from 0.28245 to 0.28265, indicating similar characteristics of dioritic rocks in the basin. We infer that granodioritic rocks occurring in the Ningwu ore district have an original relationship with dioritic rocks. These new results provide significant evidence for further study of this ore district so as to understand the ore-forming event in the study area.

关键词： Zircon U-Pb age Hf isotope porphyry iron deposit Ningwu ore district Middle–Lower Yangtze River polymetallic ore belt

Wideband high gain millimeter wave antenna based on wavy power divider for millimeter wave radar sensor

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The Journal of China Universities of Posts and Telecommunications 2025年

作者： Zhang Shuanggen Yu Tao Wang Yulan Zhou Ran cheng Zhihua School of Integrated Circuit Science and Engineering， Tianjin University of Technology

In this paper， a broadband high gain millimeter wave radar array antenna based on a wavy power divider is proposed. The radar antenna comprises a wavy power divider and a 10-element array antenna. By adjusting the wavy radius of the power divider， the surface current of the power divider is altered， resulting in better impedance matching with the antenna. This ultimately leads to a significant improvement in bandwidth performance. The 410 millimeter wave radar antenna loaded with wavy power divider exhibits an approximate enhancement of 3 GHz compared to traditional microstrip power divider antennas， and an average gain increase of 2.42 dB within the vehicle millimeter wave radar frequency band relative to the improved gradient power divider structure. The 410 millimeter wave radar antenna loaded with wavy power divider possesses the characteristics of high gain and broad bandwidth.

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有机载体对正面银浆印刷性能及电极形貌影响

电工材料 2017年第3期 11-14页

作者：韩向超张愿成刘玉杰潘熠霄贾巍上海太阳能工程技术研究中心有限公司上海200241

有机载体中加入触变剂可以改善浆料的流变性能和印刷性能。有机载体中加入流平剂和定型剂可以改善电极印刷形貌,同时使电极截面呈梯形状并提高电极的高宽比。当触变剂、流平剂和定型剂在有机载体中所占质量百分比分别为4%、11%、7%时,... 详细信息

有机载体中加入触变剂可以改善浆料的流变性能和印刷性能。有机载体中加入流平剂和定型剂可以改善电极印刷形貌,同时使电极截面呈梯形状并提高电极的高宽比。当触变剂、流平剂和定型剂在有机载体中所占质量百分比分别为4%、11%、7%时,浆料印刷性能最佳,电极线形最好。

关键词：丝网印刷正面银浆有机载体触变剂流平剂定型剂

Printing perovskite and graphene parallel structure-based optical-mechanical sensors for human-machine interaction

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Science China Technological Sciences 2025年

作者： Sisi CHEN Jiemin ZHANG Nan cheng Wenbo LI Jing LIU Hongfei XIE Jie ZHANG Yueying cheng Xiaotong ZHAO Meng SU Yanlin SONG Key Laboratory of Green Printing CAS Research/Education Center for Excellence in Molecular Sciences Institute of ChemistryChinese Academy of Sciences (ICCAS) University of Chinese Academy of Sciences Weiyang College Tsinghua University Department of Cardiovascular Surgery First Medical Center PLA General Hospital AECC Beijing Institute of Aeronautical Materials Beijing Institute of Graphene Technology Beijing Engineering Research Centre of Graphene Application School of Integrated Circuit & Beijing National Research Center for Information Science and Technology (BNRist) Tsinghua University

Surgical robots are designed to provide enhanced precision and dexterity compared to manual surgical procedures,which mainly rely on multimodal sensing technologies for the surgeon to seamlessly operate the robotic arms and *** with single-mode sensors, optical and mechanical bi-modal sensors provide improved precision, enhanced safety,and robustness of human-machine interaction systems. Here, the template-guided and pneumatic printing technologies are combined to construct perovskite and graphene parallel structures with both optical and mechanical sensing capabilities. The printed uniformly crystallized perovskite microstructure exhibits fast and sensitive photoelectric response characteristics,enabling shadow recognition functionality. The combination of graphene and elastic rubber endows the great printability to prepare parallel structures near the perovskite arrays for force sensing capabilities. Thus, the printed perovskite and graphene structures possess non-contact optical sensing capabilities to detect hand position by recognizing shadows between the hand and the sensor, as well as contact mechanical sensing capabilities to detect touch force applied by the hand. It provides a synergistic platform for real-time and multidimensional feedback to improve human-machine interaction.

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Phase saddle point transformation-enabled mode-adaptive detection of acoustic orbital angular momentum with high efficiency and low crosstalk

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Science China(Physics,Mechanics & Astronomy) 2025年

作者： Kai Wu Yang Tan Jingjing Liu Bin Liang Jianchun cheng Collaborative Innovation Center of Advanced Microstructures and Key Laboratory of Modern Acoustics MOE Institute of AcousticsDepartment of Physics Nanjing University

Acoustic orbital angular momentum (OAM) provides an infinite set of orthogonal bases in Hilbert space and significantly boosts the link capacity and data transmission rate. High-capacity and low-crosstalk OAM detection within compact physical space is highly desired to effectively harness this spatial dimension of sound wave, but the existing mechanisms generally either operate only for finite OAMs with predetermined mode orders or rely on complicated active devices. Here, we propose a phase saddle point (PSP) transformation mechanism for distinguishing and demultiplexing acoustic OAM modes in a passive, mode-adaptive,high-efficiency, and high-accuracy paradigm. The phase mask characterized by a PSP in the specific area is created through the single-pass log-polar transformation without prior information of incident modes, whose interaction with incident vortex beams of different OAM modes will yield the translation of the stationary phase point and thereby generate the corresponding focused line spots at distinct lateral positions. We theoretically elucidate the mode-adaptive response of PSP transformation by deriving the quantitative relationship between the OAM order and line spot offset. This mode adaptability enables our mechanism to detect OAM of arbitrary mode orders and mode numbers with the inter-mode crosstalk being effectively suppressed, beyond attainable with the existing methods. The effectiveness of our proposed mechanism is validated by demonstrating several distinct examples of single-mode OAM sorting and multi-mode synthesized vortex beam demultiplexing. We anticipate this modeadaptive methodology, designed for compact dimensions and featuring with low crosstalk and uniform efficiency, will find important applications in OAM information processing.

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Identification methods for anomalous stress region in coal roadways based on microseismic information and numerical simulation

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International Journal of Mining Science and Technology 2017年第3期27卷 525-530页

作者： Liu chao Li Shugang cheng cheng cheng Xiaoyu College of Safety Science and Engineering Xi'an University of Science & Technology Xi'an 710054 China Key Laboratory of Western Mine Exploitation and Hazard Prevention Ministry of Education Xi'an University of Science & Technology Xi'an 710054 China

It is believed that the microseismicity induced by mining effect and gas gradient disturbance stress is a precursor to the essential characteristics of roadway unstability. In order to effectively identify and evaluate the stability of coal roadways in the process of mine development and extraction, a microseismic monitoring system was deployed for the study of the stress evolution process, damage degree and distribution characteristics in the tailgate and headgate. The mine under study is the 62113 outburst working face of Xin Zhuangzi coalmine in Huainan mining area. The whole process of microfractures initiation,extension, interaction and coalescence mechanisms during the progressive failure processes of the coal rock within the delineated and typical event clusters were investigated by means of a two dimensional realistic failure process analysis code(RFPA2D-Flow). The results show that the microseismic events gradually create different-sized event clusters. The microseismicity of the tailgate is significantly higher than that of the headgate. The study indicates that the greater anomalous stress region matches the area where microfractures continuously develop and finally connect to each other and form a fissure *** to the mine layout and stress concentration, the ruptured area is mainly located on the left shoulder of the tailgate roof. The potential anomalous stress region of the coal roadway obtained by numerical simulation is relatively in good agreement with the trend of spatial macro evolution of coal rock microfractures captured by the microseismic monitoring system. The research results can provide important basis for understanding instability failure mechanism of deep roadway and microseismic activity law in complex geologic conditions, and it ultimately can be used to guide the selection and optimization of reinforcement and protection scheme.

关键词： Microseismic monitoring technology Numerical simulation Anomalous stress region Event clusters Microcracks

Mutual regulation of microglia and astrocytes after Gas6 inhibits spinal cord injury

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Neural Regeneration Research 2025年第2期20卷 557-573页

作者： Jiewen Chen Xiaolin Zeng Le Wang Wenwu Zhang Gang Li Xing cheng Peiqiang Su Yong Wan Xiang Li Department of Spine Surgery The First Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Guangdong Province Key Laboratory of Orthopedics and Traumatology GuangzhouGuangdong ProvinceChina

Invasive inflammation and excessive scar formation are the main reasons for the difficulty in repairing nervous tissue after spinal cord *** and astrocytes play key roles in the spinal cord injury micro-environment and share a close ***,the mechanisms involved remain *** this study,we found that after spinal cord injury,resting microglia(M0)were polarized into pro-inflammatory phenotypes(MG1 and MG3),while resting astrocytes were polarized into reactive and scar-forming *** expression of growth arrest-specific 6(Gas6)and its receptor Axl were significantly down-regulated in microglia and astrocytes after spinal cord *** vitro experiments showed that Gas6 had negative effects on the polarization of reactive astrocytes and pro-inflammatory microglia,and even inhibited the cross-regulation between *** further demonstrated that Gas6 can inhibit the polarization of reactive astrocytes by suppressing the activation of the Yes-associated protein signaling ***,in turn,inhibited the polarization of pro-inflammatory microglia by suppressing the activation of the nuclear factor-κB/p65 and Janus kinase/signal transducer and activator of transcription signaling *** vivo experiments showed that Gas6 inhibited the polarization of pro-inflammatory microglia and reactive astrocytes in the injured spinal cord,thereby promoting tissue repair and motor function ***,Gas6 may play a role in the treatment of spinal cord *** can inhibit the inflammatory pathway of microglia and polarization of astrocytes,attenuate the interaction between microglia and astrocytes in the inflammatory microenvironment,and thereby alleviate local inflammation and reduce scar formation in the spinal cord.

关键词： astrocytes Axl cell polarization Gas6 Hippo signal inflammatory micro-environment intercellular interaction microglia single-cell sequencing spinal cord injury

Kineto-elastodynamic analysis of hose cutting mechanism of an aluminum electrolytic capacitor casing machine

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Journal of Central South University 2017年第5期24卷 1217-1224页

作者： XIA Bi-zhong REN Shi-yuan LIU Xin-cheng XU chao Division of Advanced Manufacturing Graduate School at ShenzhenTsinghua UniversityShenzhen 518055China

The kineto-elastodynamic(KED) model of a hose cutting mechanism used in the aluminum electrolytic capacitor(AEC) casing machine is developed to investigate the dynamic characteristics. According to the composition characteristics, the cutting mechanism is divided into cam-roller and linkage two substructures. And the dynamic models of the two substructures are established using the lumped parameter method and finite element method(FEM), respectively. In the model, the compliances of the camshaft and the links are taken into consideration. The elastic displacement of the links, angular error of the cutter and the dynamic stress of the links are analyzed based on the KED model. The results provide important information for structure optimization and vibration control of the mechanism.

关键词： cutting mechanism kineto-elastodynamic lumped parameter method finite element method dynamic stress