• 제목/요약/키워드: Ping

검색결과 1,340건 처리시간 0.029초

Scour below pipelines due to random waves alone and random waves plus currents on mild slopes

  • Myrhaug, Dag;Fu, Ping;Ong, Muk Chen
    • Ocean Systems Engineering
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    • 제7권3호
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    • pp.275-298
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    • 2017
  • This paper provides a practical stochastic method by which the maximum equilibrium scour depth below a pipeline exposed to random waves plus a current on mild slopes can be derived. The approach is based on assuming the waves to be a stationary narrow-band random process, adopting the Battjes and Groenendijk (2000) wave height distribution for mild slopes including the effect of breaking waves, and using the empirical formulas for the scour depth on the horizontal seabed by Sumer and Fredsøe (1996). The present approach is valid for wave-dominant flow conditions. Results for random waves alone and random wave plus currents have been presented and discussed by varying the seabed slope and water depth. An approximate method is also proposed, and comparisons are made with the present stochastic method. For random waves alone it appears that the approximate method can replace the stochastic method, whereas the stochastic method is required for random waves plus currents. Tentative approaches to related random wave-induced scour cases for random waves alone are also suggested.

Effects of Monoclonal Antibodies against Human Stathmin Combined with Paclitaxel on Proliferation of the QG-56 Human Lung Carcinoma Cell Line

  • Yuan, Shao-Fei;Chen, Wen-Jun;Zhu, Lin-Jia;Zheng, Wei-E.;Chen, Hua;Xiong, Jian-Ping
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권6호
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    • pp.2967-2971
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    • 2012
  • Objective: To explore whether monoclonal antibodies against stathmin and the chemotherapuetic agent paclitaxel have synergenic effects in inhibiting growth and inducing apoptosis in human QG-56 cells. Methods: QG-56 cells were treated with monoclonal antibodies against stathmin or paclitaxel alone or in combination, with untreated cells used as controls. After 24, 48, 72 and 96 hours the cell growth condition was observed under an inverted microscope and inhibition was studied by MTT assay; apoptosis was analyzed by flow cytometry. Results: The populations decreased and cell shape and size changed after the various treatments. Monoclonal antibodies against stathmin and paclitaxel used alone or incombination inhibited the proliferation of QG-56 cells, especially in combination with synergism (P<0.05). Combined treatment also resulted in a significantly higher apoptosis rate than in the other groups (P<0.05). Conclusions: Monoclonal antibodies against stathmin and paclitaxel used alone or in combination can inhibit proliferation of QG-56 cells and induce apoptosis when applied together. The observed synergistic effects may have important implications for clinical application.

miR-124 Inhibits Growth and Invasion of Gastric Cancer by Targeting ROCK1

  • Hu, Cong-Bing;Li, Qiao-Lin;Hu, Jian-Fei;Zhang, Qiang;Xie, Jian-Ping;Deng, Li
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권16호
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    • pp.6543-6546
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    • 2014
  • MicroRNAs (miRNAs) act as critical regulators of genes involved in many biological processes. Aberrant alteration of miRNAs have been found in many cancers, including gastric cancer (GC), but the molecular mechanisms are not well understood. Herein, we investigated the role of miR-124 in GC. We found that its expression was significantly reduced in both GC tissue samples and cell lines. Forced expression of miR-124 suppressed GC cell proliferation, migration, and invasion. Furthermore, the Rho-associated protein kinase (ROCK1) was identified as a direct target of miR-124 in GC cells. Finally, silencing of ROCK1 showed similar effects as miR-124 overexpression, while supplementation of ROCK1 remarkably restored the cell growth and invasion inhibited by miR-124. Together, our data demonstrate that miR-124 acts as a tumor suppressor by targeting ROCK1, and posit miR-124 as a novel strategy for GC treatment.

Cinobufacin Suppresses Cell Proliferation via miR-494 in BGC-823 Gastric Cancer Cells

  • Zhou, Rong-Ping;Chen, Gang;Shen, Zhi-Li;Pan, Li-Qun
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권3호
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    • pp.1241-1245
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    • 2014
  • Cinobufacin is used clinically to treat patients with many solid malignant tumors. However, the mechanisms underlying action remain to be detailed. Our study focused on miRNAs involved in cinobufacin inhibition of GC cell proliferation. miRNA microarray analysis and real time PCR identified miR-494 as a significant cinobufacin-associated miRNA. In vivo, ectopic expression of miR-494 inhibited the proliferation and induced apoptosis of BGC-823 cells on CCK-8 and flow cytometry analysis. Further study verified BAG-1 (anti-apoptosis gene) to bea target of miR-494 by luciferase reporter assay and Western blotting. In summary, our study demonstrated that cinobufacin may inhibit the proliferation and promote the apoptosis of BGC-823 cells. Cinobufacin-associated miR-494 may indirectly be involved in cell proliferation and apoptosis by targeting BAG-1, pointing to use as a potential molecular target of cinobufacin in gastric cancer therapy.

Capability for Change at Community Health Centers Serving Asian Pacific Islanders: An Exploratory Study of a Cancer Screening Evidence-based Intervention

  • Sohng, Hee Yon;Kuniyuki, Alan;Edelson, Jane;Weir, Rosy Chang;Song, Hui;Tu, Shin-Ping
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권12호
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    • pp.7451-7457
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    • 2013
  • Background: Understanding and enhancing change capabilities, including Practice Adaptive Reserve (PAR), of Community Health Centers (CHCs) may mitigate cancer-related health disparities. Materials and Methods: Using stratified random sampling, we recruited 232 staff from seven CHCs serving Asian Pacific Islander communities to complete a self-administered survey. We performed multilevel regression analyses to examine PAR composite scores by CHC, position type, and number of years worked at their clinic. Results: The mean PAR score was 0.7 (s.d. 0.14). Higher scores were associated with a greater perceived likelihood that clinic staff would participate in an evidence-based intervention (EBI). Constructs such as communication, clinic flow, sensemaking, change valence, and resource availability were positively associated with EBI implementation or trended toward significance. Conclusions: PAR scores are positively associated with perceived likelihood of clinic staff participation in cancer screening EBI. Future research is needed to determine PAR levels most conducive to implementing change and to developing interventions that enhance Adaptive Reserve.

Myosin VI contributes to malignant proliferation of human glioma cells

  • Xu, Rong;Fang, Xu-hao;Zhong, Ping
    • The Korean Journal of Physiology and Pharmacology
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    • 제20권2호
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    • pp.139-145
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    • 2016
  • Previously characterized as a backward motor, myosin VI (MYO6), which belongs to myosin family, moves toward the minus end of the actin track, a direction opposite to all other known myosin members. Recent researches have illuminated the role of MYO6 in human cancers, particularly in prostate cancer. However, the role of MYO6 in glioma has not yet been determined. In this study, to explore the role of MYO6 in human glioma, lentivirus-delivered short hairpin RNA (shRNA) targeting MYO6 was designed to stably down-regulate its endogenous expression in glioblastoma cells U251. Knockdown of MYO6 significantly inhibited viability and proliferation of U251 cells in vitro. Moreover, the cell cycle of U251 cells was arrested at G0/G1 phase with the absence of MYO6, which could contribute to the suppression of cell proliferation. In conclusion, we firstly identified the crucial involvement of MYO6 in human glioma. The inhibition of MYO6 by shRNA might be a potential therapeutic method in human glioma.

ON THE m-POTENT RANKS OF CERTAIN SEMIGROUPS OF ORIENTATION PRESERVING TRANSFORMATIONS

  • Zhao, Ping;You, Taijie;Hu, Huabi
    • 대한수학회보
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    • 제51권6호
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    • pp.1841-1850
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    • 2014
  • It is known that the ranks of the semigroups $\mathcal{SOP}_n$, $\mathcal{SPOP}_n$ and $\mathcal{SSPOP}_n$ (the semigroups of orientation preserving singular self-maps, partial and strictly partial transformations on $X_n={1,2,{\ldots},n}$, respectively) are n, 2n and n + 1, respectively. The idempotent rank, defined as the smallest number of idempotent generating set, of $\mathcal{SOP}_n$ and $\mathcal{SSPOP}_n$ are the same value as the rank, respectively. Idempotent can be seen as a special case (with m = 1) of m-potent. In this paper, we investigate the m-potent ranks, defined as the smallest number of m-potent generating set, of the semigroups $\mathcal{SOP}_n$, $\mathcal{SPOP}_n$ and $\mathcal{SSPOP}_n$. Firstly, we characterize the structure of the minimal generating sets of $\mathcal{SOP}_n$. As applications, we obtain that the number of distinct minimal generating sets is $(n-1)^nn!$. Secondly, we show that, for $1{\leq}m{\leq}n-1$, the m-potent ranks of the semigroups $\mathcal{SOP}_n$ and $\mathcal{SPOP}_n$ are also n and 2n, respectively. Finally, we find that the 2-potent rank of $\mathcal{SSPOP}_n$ is n + 1.

연료 활성화를 위한 디젤 미립화 장치의 수치해석 연구 (Numerical Study of Diesel Atomization Device for Fuel Activation)

  • 최상인;;서호석;김상범;조영민
    • 한국대기환경학회지
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    • 제33권4호
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    • pp.306-318
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    • 2017
  • Heavy diesel vehicles are one of major sources of urban fine dust in Korea and other developing countries. In this study, an auxiliary device assisting fuel atomization, which is called FAD (Fuel Activation Device), was closely reviewed through numerical simulation. As calculated, the diesel flow velocity passing across FAD increased up to 1.68 times, and it enhanced the cavitation effect which could improve the injected fuel atomization. Super cavitation phenomenon, which is the most important effect on nozzle injection, has occurred until the cavitation number (${\sigma}$) decreased from 1.15 to 1.09, and atomized droplets via a nozzle of which opening was $500{\mu}m$ distributed less than $200{\mu}m$ in sauter mean diameter (SMD).

Molecular Modeling and its Experimental Verification for the Catalytic Mechanism of Candida antarctica Lipase B

  • Kwon, Cheong-Hoon;Shin, Dae-Young;Lee, Jong-Ho;Kim, Seung-Wook;Kang, Jeong-Won
    • Journal of Microbiology and Biotechnology
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    • 제17권7호
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    • pp.1098-1105
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    • 2007
  • Quantum mechanical and molecular dynamics simulation analysis has been performed on the model system for CALB (Candida antarctica lipase B) with esters to study the reaction mechanism and conformational preference of catalytic hydrolysis and the esterification reaction. Using quantum mechanical analysis, the ping-pong bi-bi mechanism was applied and energies and 3-dimensional binding configurations of the whole reaction pathways were calculated. Further molecular dynamics simulation analysis was performed on the basis of the transition state obtained from quantum mechanical study to observe the effect of structures of the substrates. Calculation results using substrates of different chain length and chiral configurations were compared for conformational preference. The calculated results showed very small influence on chain length, whereas chiral conformation showed big differences. Calculated results from molecular modeling studies have been compared qualitatively with the experimental data using racemic mixtures of (${\pm}$)-cis-4-acetamido-cyclopent-2-ene-1-ethyl acetate as substrates.

Line-Interactive UPS for Low-Voltage Microgrids

  • Zhang, Ping;Cai, Huanyu;Zhao, Hengyang;Shi, Jianjiang;He, Xiangning
    • Journal of Power Electronics
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    • 제15권6호
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    • pp.1628-1639
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    • 2015
  • Line-interactive uninterruptible power supply (UPS) systems are good candidates for providing energy storage within a microgrid. In this paper, a control scheme for a line-interactive UPS system applied in a low-voltage microgrid is presented. It is based on the Q-w and P-E droop control to achieve a seamless transition between grid-connected and stand-alone operation modes. Moreover, a new model for designing the controllers is built in the dq-frame based on the instantaneous power definition. The new-built model takes into account the dynamic performance of the output impedance of the inverter in the dq-frame and can be evaluated in the time domain. Compared to the traditional model based on the instantaneous power definition, the new-built model is more accurate to describe the dynamic performance of the system. Simulation and experimental results obtained with a microgrid consisting of two 40-kW line-interactive UPS systems are given to validate the control strategy of the line-active UPS system and the accuracy of the new-built model.