• Title/Summary/Keyword: large-cell

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Induced Epidermal Cell Turnover in the Seawater-Adopted Guppy, Poecilia reticulata

  • Wha Sun Kang;Young Wha Moon;Ji Won Han;No Gi Park;Han Hwa Kim
    • Animal cells and systems
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    • v.2 no.4
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    • pp.521-527
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    • 1998
  • The turnover of epidermal cells after seawater adaptation of the freshwater fishwas studied in the guppy (Poecilia reticulata) by means of Proliferating cell nucleus antigen (PCNA) immunocytochemistry and transmission electron microscopy. The number of PCNA-immunoreactive cells in the epidermis of the seawater-adapted guppies, which becomes thinner than that in the fresh-water, generally increases four times as much. Degeneration of filament-containing cells by necrosis or apoptosis occurs mainly in epidermal cells. Apoptotic filament-containing cells seem to be shed into the water in the environment instead of phagocytosis by adjacent macrophages. The apoptotic chloride cell has a highly condensed cytoplasm and the lumen of tubular system is distended. The apoptotic mucous cell, which has an electron-dense cytoplasm, is characterized by the presence of a large multivesicular body of different electron densities. Macrophages contain many electron-dense lysosomal bodies and large vesicles filled with cellular debris. It is concluded that mitosis and apoptosis of epidermal cells are greatly stimulated when fish are adapting to seawater. This result reflects an increase in epidermal cell turnover by change of environmental salinity.

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On the Multiuser Diversity in SIMO Interfering Multiple Access Channels: Distributed User Scheduling Framework

  • Shin, Won-Yong;Park, Dohyung;Jung, Bang Chul
    • Journal of Communications and Networks
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    • v.17 no.3
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    • pp.267-274
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    • 2015
  • Due to the difficulty of coordination in the cellular uplink, it is a practical challenge how to achieve the optimal throughput scaling with distributed scheduling. In this paper, we propose a distributed and opportunistic user scheduling (DOUS) that achieves the optimal throughput scaling in a single-input multiple-output interfering multiple-access channel, i.e., a multi-cell uplink network, with M antennas at each base station (BS) and N users in a cell. In a distributed fashion, each BS adopts M random receive beamforming vectors and then selects M users such that both sufficiently large desired signal power and sufficiently small generating interference are guaranteed. As a main result, it is proved that full multiuser diversity gain can be achieved in each cell when a sufficiently large number of users exist. Numerical evaluation confirms that in a practical setting of the multi-cell network, the proposed DOUS outperforms the existing distributed user scheduling algorithms in terms of sum-rate.

Simulation of Containment Pressurization in a Large Break-Loss of Coolant Accident Using Single-Cell and Multicell Models and CONTAIN Code

  • Noori-Kalkhoran, Omid;Shirani, Amir Saied;Ahangari, Rohollah
    • Nuclear Engineering and Technology
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    • v.48 no.5
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    • pp.1140-1153
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    • 2016
  • Since the inception of nuclear power as a commercial energy source, safety has been recognized as a prime consideration in the design, construction, operation, maintenance, and decommissioning of nuclear power plants. The release of radioactivity to the environment requires the failure of multiple safety systems and the breach of three physical barriers: fuel cladding, the reactor cooling system, and containment. In this study, nuclear reactor containment pressurization has been modeled in a large break-loss of coolant accident (LB-LOCA) by programming single-cell and multicell models in MATLAB. First, containment has been considered as a control volume (single-cell model). In addition, spray operation has been added to this model. In the second step, the single-cell model has been developed into a multicell model to consider the effects of the nodalization and spatial location of cells in the containment pressurization in comparison with the single-cell model. In the third step, the accident has been simulated using the CONTAIN 2.0 code. Finally, Bushehr nuclear power plant (BNPP) containment has been considered as a case study. The results of BNPP containment pressurization due to LB-LOCA have been compared between models, final safety analysis report, and CONTAIN code's results.

Isolation and Identification of Nonpolar Taxane Derivatives from the Plant Cell Culture of Taxus chinensis

  • Gi, Un-Sook;Min, Bumchan;Hong, Seung-Suh;Lee, Hyun-Soo;Kim, Jin-Hyun
    • Journal of Applied Biological Chemistry
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    • v.43 no.3
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    • pp.176-179
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    • 2000
  • Nonpolar taxoides extracted from a large-scale cell culture of Taxus chinensis were isolated through the normal and reverse phase column chromatographies, and their compounds were identified via NMR spectroscopy. The complete separation method was systematically established and described. In dichloromethane, dissolved paclitaxel and other taxoids with hexane were precipitated during the purification of paclitaxel from the plant cell culture of T. chinensis through a large-scale process while the relatively nonpolar taxane derivatives remained dissolved in the hexane phase. 13-Deoxy baccatin III (I), baccatin VI (II), taxchinin I (III), $2{\alpha}$, $5{\alpha}$, $10{\beta}$, $14{\beta}$-tetraacetoxy-4(20), 11-taxadiene(IV), 1-deoxy baccatinVI(V), and taxayuntin C (VI) were isolated through column chromatography and identified via NMR spectroscopy. Compounds I and IV were found to the major components, aside from paclitaxel, in the plant cell culture of T. chinensis. The concentrations of I and IV were compared with the that concentration of the paclitaxel in each of plant cell culture. The possible applications of compounds I, II, IV, and V were discussed.

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Creative Design of Large-Angle Pin Type Load Cell for the Overload Limiter of a Movable Crane (이동식크레인의 과부하방지장치용 광각도 핀형 로드셀의 창의적 설계)

  • Han, Dong Seop;Ha, Jeong Min;Han, Geun Jo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.9 no.1
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    • pp.35-41
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    • 2010
  • An overload limiter is used to prevent its overturning accident during an operation of a movable crane. Recently the indirect measuring method, which measures hoisting load and overturning moment of overload limiter, demands instead of the existing method, which measures only hoisting load. The indirectly measuring method is how to conduct the hoisting load and overturning moment as measuring the load of hydraulic cylinder for a luffing driving of boom. So we need to develop the multi-angular pin type load cell with the measuring angle of ${\pm}10$ degree instead of the existing load cell with the measuring angle of ${\pm}2$ degree. In this study the finite element analysis is conducted to evaluate the effect of the aspect ratio of measuring cross section on the measuring limit of the load cell to develop the many-angular pin type load cell. For this investigation, the aspect ratio of measuring cross section and load applying angle were adopted as design parameters and the stresses of measuring part were evaluated for each parameter.

Optical-Electronic Method for Statistical Evaluation of Human Corneal Endothelial Patterns (Human Corneal Endothelial 패턴의 통계적 분석을 위한 광전자적 방법)

  • Lee, Yim-Kul
    • Proceedings of the KOSOMBE Conference
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    • v.1992 no.11
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    • pp.58-62
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    • 1992
  • Hybrid optical-electronic procedures are introduced for the automated estimation of cell parameters (e.g., size, size variation, and shape). Two different optical Fourier analysis procedures are applied to high contrast cell boundary patterns obtained from specular micrographs of the endothelial layer. In one case, a large number of cell patterns are illuminated to extract average cell size information. Once the average cell size information has been obtained, individual cells are illuminated to extract shape information.

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Elementary School Teachers에 Conceptions on Cell (초등학교 교사들의 세포에 대한 개념)

  • 장명덕;송남희
    • Journal of Korean Elementary Science Education
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    • v.17 no.2
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    • pp.79-90
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    • 1998
  • The purpose of this study is to investigate degree of the concept formation on cell in elementary school teachers and to clarify the patterns of their misconceptions. Data were collected by interview with 120 elementary school teachers, ranged from twenties to fifties in age, working in Taegu city. The instrument was developed by researchers and was categorized into four: cell as the basic units of life, morphology of cell, function of cell, growth of individual from the viewpoint of cell. The results are as follows: First, about 80% of teachers had two perspective outcome of cell: Cells are the basic units of life on earth. But the potato and meat, which we used to eat as food, are not constructed of cells but aggregated of nutrients. Second, most of elementary school teachers recognized that shapes of the cell in organisms were diverse, but some of them only could present several kinds of shape on cell. The 35% of teachers had misconception that shape of cell is all the same in a individual. It shows that this result is caused by lack of opportunity to observe the various kinds of cells. Third, most teachers understood tell can be seen only through a microscope. Yet in comparison with relative size, it was revealed that misconception of cell size was induced by the term of 'basic unit'. In addition, they thought that large organisms are built from large cells, and small organisms from small cells. Fourth, Elementary school teachers used to confuse the terms between chloroplast and chlorophyll, and believed that the genetic material was contained only in the reproductive cells and seeds. It was also revealed that they thought the nutrients such as starch and fat are located at intercellular space. Fifth, the 60% of teachers conceived correctly that growth of individual depends on mitosis and increase in cell number. The rest of them, however, misunderstood that it is due to the increase of tell volume.

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A Study on Inter Band Interference and PAPR Reduction in Multi-Cell System based on OFDM Techniques (OFDM 기법에 기반한 Multi-Cell 시스템에서 PAPR 감소와 대역간 간섭에 관한 연구)

  • Kim, Wan-Tae;Yoo, Sun-Yong;Jo, Sung-Joon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.10a
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    • pp.693-696
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    • 2008
  • The systems for mobile communication services of fourth generation use OFDM (Orthogonal Frequency Division Multiplexing) scheme that ran transmit large amounts of data to support the multimedia services, and consist of several types of cell, such as Macro Cell, Pico Cell, Femto Cell to improve the qualify of service. According to subdivision of communication region, superposition of cells in co-channel different from conventional single cell is used, but it cause inter band interference between systems. In particular, an OFDM signal consists of a number of independently modulated subcarriers, and superposition of these subcarriers causes a problem that ran give a large PAPR. Increased PAPR induces signal distortion passing through components such as power amplifier so that inter band interference is caused by out-of-band spectrum radiation. In order to minimize the inter band interference, this paper applies PAPR reduction scheme and analyzes the out-of-band spectrum radiation when the signal passes through nonlinear components such an power amplifier.

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