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      • Thiamethoxam Induces Meiotic Arrest and Affects Embryo Developmental Potential of Bovine Oocytes

        Zheng-Wen Nie,Ying-Jie Niu,Wenjun Zhou,Yong-Han Kim,Kyung-Tae Shin,Xiang-Shun Cui 한국수정란이식학회 2018 한국수정란이식학회 학술대회 Vol.2018 No.11

        Thiamethoxam (TMX) is a neonicotinoid insecticide. Residues of TMX have been detected in various crops. Although it has specific high toxicity to insects and is designed to exterminate them, the toxicity has also found in mammals recently. Differ from acetylcholine toxicity, TMX has peroxide toxicity in mammals. Matured oocytes have the capacity of fertilization, but oocytes own abundant mitochondria and its maturation is vulnerable to reactive oxygen species (ROS). Excessive production of reactive oxygen species (ROS) can override antioxidant defenses, produce oxidative stress and DNA damage that triggers apoptosis and necrosis in organisms. However little is known about the harm of ROS induced by TMX during oocytes maturation. Here, bovine germ-vesicle (GV) oocytes were cultured to metaphase of the second meiosis (MII) stage in vitro with or without TMX. During this process, oocytes were evaluated by various methods. Microscopic examination showed that 1.6 mM TMX significantly inhibited the maturation process in which oocytes were arrested before MI stage or between MI and MII stage. Correspond to this two periods, immunofluorescence staining and enzyme activity analysis showed that active CDC25 and CDC2 reduced in TMX group compared to control; time lapse and immunofluorescence staining gave results that Cyclin B could not be degraded, actin cap could not form, and Bub3 could not be removed from kinetochores. In addition, MII oocytes exposed to TMX showed disordered chromosomes and spindle. To study further, oocytes cultured for 24 h were analyzed. On the one hand, these oocytes in TMX group accumulated more ROS and produced significantly decreased mitochondrial membrane potential and increased apoptotic signal compared to control by methods of quantities for dichlorodihydrofluorescein diacetate (DCHFDA), 5,5′,6,6′-Tetrachloro-1,1′,3,3′-tetraethyl-imidacarbocyanine iodide and Annexin-V, but the level of γH2AX protein in TMX group did not decline significantly compared with control. On the another hand, these oocytes were activated to be parthenogenetic embryos and cultured. Assessment for embryo development showed decreased rates of cleavage, morula and blastocyst in TMX group compared to control in vitro. In conclusion, these results suggest that ROS induced by TMX results in dysfunction of mitochondria and apoptosis, which block bovine oocytes to MI stage, trap them at AI/TI stage and trigger disordered chromosomes and spindle at MII stage. Additionally, MII oocytes with poor qualities result from TMX lose abilities to cleavage and develop to be morulae and blastocysts.

      • Function and Regulation Mechanism of Cyclin E1 during Development of Early Porcine Embryos

        Zheng-Wen Nie,Jing Guo,Duk-Jung Kim,Nam-Hyung Kim,Xiang-Shun Cui 한국동물생명공학회(구 한국동물번식학회) 2017 발생공학 국제심포지엄 및 학술대회 Vol.2017 No.10

        Cyclin E1 (CCNE1) is a core component of cell cycle regulation that drives the transition into the S phase. CCNE1 plays critical roles in cell cycle, cell proliferation, and cellular functions. However, the function of CCNE1 in early embryonic development is limited. In the present study, the function and expression of Ccne1 in porcine early parthenotes were examined. Immunostaining experiments showed that CCNE1 localized in the nucleus, starting at the four-cell stage. Knockdown of Ccne1 by double-stranded RNA resulted in the failure of blastocyst formation and induced blastocyst apoptosis. Ccne1 depletion increased expression of the pro-apoptotic gene Bax, and decreased the expression of Oct4 and the rate of inner cell mass (ICM)/trophectoderm formation. The results indicated that CCNE1 affects blastocyst formation by inducing cell apoptosis and ICM formation during porcine embryonic development.

      • SCIESCOPUS

        Numerical and experimental study of multi-bench retained excavations

        Zheng, Gang,Nie, Dongqing,Diao, Yu,Liu, Jie,Cheng, Xuesong Techno-Press 2017 Geomechanics & engineering Vol.13 No.5

        Earth berms are often left in place to support retaining walls or piles in order to eliminate horizontal struts in excavations of soft soil areas. However, if the excavation depth is relatively large, an earth berm-supported retaining system may not be applicable and could be replaced by a multi-bench retaining system. However, studies on multi-bench retaining systems are limited. The goal of this investigation is to study the deformation characteristics, internal forces and interaction mechanisms of the retaining structures in a multi-bench retaining system and the failure modes of this retaining system. Therefore, a series of model tests of a two-bench retaining system was designed and conducted, and corresponding finite difference simulations were developed to back-analyze the model tests and for further analysis. The tests and numerical results show that the distance between the two rows of retaining piles (bench width) and their embedded lengths can significantly influence the relative movement between the piles; this relative movement determines the horizontal stress distribution in the soil between the two rows of piles (i.e., the bench zone) and thus determines the bending moments in the retaining piles. As the bench width increases, the deformations and bending moments in the retaining piles decrease, while the excavation stability increases. If the second retaining piles are longer than a certain length, they will experience a larger bending moment than the first retaining piles and become the primary retaining structure. In addition, for varying bench widths, the slip surface formation differs, and the failure modes of two-bench retained excavations can be divided into three types: integrated failure, interactive failure and disconnected failure.

      • Dynamic Characteristic Simulation of Helicopter Tail Drive Shaft System

        Nie Junfeng,Yu Guangbin,Song Ye,Qu Zhigang,Zheng Minli,Zhao Xingfu 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.6

        Helicopter with the advantage of light, flexible and hovering in the air, is widely used. In both military and civilian domain, it gets more and more attention. It becomes the main subject of research in the world. In the power transmission system of helicopter, the tail rotor shaft is an important part. It is one of the key technologies to predict the dynamic characteristics of the shaft accurately for improving the overall performance of the helicopter. Based on the theory of elastic mechanics, rotor dynamics and the finite element analysis, the former main drive shaft is taken as an example. The dynamic characteristics of the transmission shaft is calculated by the multi/few degrees of freedom finite element method. The validity of the finite element method with few degrees of freedom is determined. Then the structure characteristics of the helicopter tail drive shaft are analyzed, and the dynamic characteristics of the helicopter tail rotor shaft are calculated by using the finite element method with few degrees of freedom. The research results provide the basis and guidance for the design of the helicopter tail drive system.

      • Stable and Active Oxidation Catalysis by Cooperative Lattice Oxygen Redox on SmMn<sub>2</sub>O<sub>5</sub> Mullite Surface

        Zheng, Yongping,Thampy, Sampreetha,Ashburn, Nickolas,Dillon, Sean,Wang, Luhua,Jangjou, Yasser,Tan, Kui,Kong, Fantai,Nie, Yifan,Kim, Moon J.,Epling, William S.,Chabal, Yves J.,Hsu, Julia W. P.,Cho, Kye American Chemical Society 2019 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.141 No.27

        <P>The correlation between lattice oxygen (O) binding energy and O oxidation activity imposes a fundamental limit in developing oxide catalysts, simultaneously meeting the stringent thermal stability and catalytic activity standards for complete oxidation reactions under harsh conditions. Typically, strong O binding indicates a stable surface structure, but low O oxidation activity, and <I>vice</I><I>versa</I>. Using nitric oxide (NO) catalytic oxidation as a model reaction, we demonstrate that this conflicting correlation can be avoided by cooperative lattice oxygen redox on SmMn<SUB>2</SUB>O<SUB>5</SUB> mullite oxides, leading to stable and active oxide surface structures. The strongly bound neighboring lattice oxygen pair cooperates in NO oxidation to form bridging nitrate (NO<SUB>3</SUB><SUP>-</SUP>) intermediates, which can facilely transform into monodentate NO<SUB>3</SUB><SUP>-</SUP> by a concerted rotation with simultaneous O<SUB>2</SUB> adsorption onto the resulting oxygen vacancy. Subsequently, monodentate NO<SUB>3</SUB><SUP>-</SUP> species decompose to NO<SUB>2</SUB> to restore one of the lattice oxygen atoms that act as a reversible redox center, and the vacancy can easily activate O<SUB>2</SUB> to replenish the consumed one. This discovery not only provides insights into the cooperative reaction mechanism but also aids the design of oxidation catalysts with the strong O binding region, offering strong activation of O<SUB>2</SUB>, high O activity, and high thermal stability in harsh conditions.</P> [FIG OMISSION]</BR>

      • Research on Nonlinear Vibration Characteristics of Spiral Bevel Gear

        Nie Junfeng,Yu Guangbin,Song Ye,Qu Zhigang,Zheng Minli,Zhao Xingfu 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.2

        Based on the concentrated parameters theory, a 7-freedom coupled vibration dynamic model of the spiral bevel gear transmission system is established, which includes transmission error, time-varying mesh stiffness and the tooth backlash clearance. In the model, the axial vibration, the torsion oscillation of the gear pair aroused by tooth meshing force and the lateral oscillations resulting from flexional deformation of the gear shaft are taken into account. The mesh stiffness fluctuation is developed as 5-order Fourier series and the tooth backlash clearance is fitted by 7-order polynomial function. Through the Gear method, the dynamic response of the system is obtained, and the vibration characteristics are analyzed.

      • An Energy-efficient Transmission Scheme for Wireless Sensor Network with DSC and virtual MIMO

        Guoqiang Zheng,Fangge Nie,Bing Li,Huahong Ma,Jishun Li,Yujun Xue,Peipei Li 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.10

        Energy efficiency is one of the primary performance parametersin wireless sensor network (WSN). The data collected by neighboring nodesin the high density WSN tend to have a high correlation which isdirectly transmitted to the sink node (DGN) will seriously reduce the energy efficiency of wireless sensor networks.For improving the energy efficiency of high node density WSN, We introduce distributed source coding (DSC) which can compress the high correlation source data into WSNbased on virtual MIMO. In the simulationresults indicate thatDSC can effectively reduce the energy consumption in data transmission and improve the energy efficiencyof the whole WSN.

      • KCI등재

        Incidence and Risk Factors of the Caudal Screw Loosening after Pelvic Fixation for Adult Spinal Deformity: A Systematic Review and Meta-analysis

        Zhao Jian,Nie Zheng,Zhou Jiangjun,Liao Dongfa,Liu Da 대한척추외과학회 2024 Asian Spine Journal Vol.18 No.1

        The purpose of this study was to assess the factors affecting caudal screw loosening after spinopelvic fixation for adult patients with spinal deformity. This meta-analysis calculated the weighted mean difference (WMD) and odds ratio (OR) using Review Manager ver. 5.3 (RevMan; Cochrane, London, UK). The loosening group was older than the control group (WMD, 2.17; 95% confidence interval [CI], 0.48–3.87; <i>p</i>=0.01). The S2 alar-iliac (S2AI) could prevent the caudal screw from loosening (OR, 0.43; 95% CI, 0.20–0.94; <i>p</i>=0.03). However, gender distribution (<i>p</i>=0.36), the number of fusion segments (<i>p</i>=0.24), rod breakage (<i>p</i>=0.97), T-score (<i>p</i>=0.10), and proximal junctional kyphosis (<i>p</i>=0.75) demonstrated no difference. Preoperatively, only pelvic incidence (PI) in the loosening group was higher (WMD, 5.08; 95% CI, 2.71–7.45; <i>p</i><0.01), while thoracic kyphosis (<i>p</i>=0.09), lumbar lordosis (LL) (<i>p</i>=0.69), pelvic tilt (PT) (<i>p</i>=0.31), pelvic incidence minus lumbar lordosis (PI–LL) (<i>p</i>=0.35), sagittal vertical axis (SVA) (<i>p</i>=0.27), and T1 pelvic angle (TPA) demonstrated no difference (<i>p</i>=0.10). PI–LL (WMD, 6.05; 95% CI, 0.96–11.14; <i>p</i>=0.02), PT (WMD, 4.12; 95% CI, 0.99–7.26; <i>p</i>=0.01), TPA (WMD, 4.72; 95% CI, 2.35–7.09; <i>p</i><0.01), and SVA (WMD, 13.35; 95% CI, 2.83–3.87; <i>p</i>=0.001) were higher in the screw loosening group immediately postoperatively. However, TK (<i>p</i>=0.24) and LL (<i>p</i>=0.44) demonstrated no difference. TPA (WMD, 8.38; 95% CI, 3.30–13.47; <i>p</i><0.01), PT (WMD, 6.01; 95% CI, 1.47–10.55; <i>p</i>=0.01), and SVA (WMD, 23.13; 95% CI, 12.06–34.21; <i>p</i><0.01) were higher in the screw loosening group at the final follow-up. However, PI–LL (<i>p</i>=0.17) demonstrated no significant difference. Elderly individuals were more susceptible to the caudal screw loosening, and the S2AI screw might better reduce the caudal screw loosening rate than the iliac screws. The lumbar lordosis and sagittal alignment should be reconstructed properly to prevent the caudal screw from loosening. Measures to block sagittal alignment deterioration could also prevent the caudal screw from loosening.

      • Gust Response and Active Suppress based on Reduced Order Models

        Yang, Guowei,Nie, Xueyuan,Zheng, Guannan The Society for Aerospace System Engineering 2015 International Journal of Aerospace System Engineer Vol.2 No.2

        A gust response analyses method based on Reduced Order Models (ROMs) was developed in the paper. Firstly, taken random signal as the input signal and adopt Single Input-Multi-Output (SIMO) training fashion, a ROM based on Auto-Regressive and Moving Average model (ARMA) was established and validated with the comparison of CFD/CSD and experiment. Then, by introducing control surface deflection and control laws, flutter active suppress was studied. Lastly, through filtering and transferring function, the gust temporal signal is obtained based on Dryden gust model, and gust response and suppress were simulated.

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