• Title/Summary/Keyword: delay cell

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Mobile Agent Based Route Search Method Using Genetic Algorithm (유전 알고리즘을 이용한 이동 에이전트 기반의 경로 탐색 기법)

  • Ji, Hong-il;Moon, Seok-hwan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.10a
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    • pp.599-602
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    • 2014
  • Proposal algorithm in this thesis introduced cells, units of router group, for distributed processing of previous genetic algorithm. This thesis presented ways to reduce search delay time of overall network through cell-based genetic algorithm. With regard to procedures of proposal algorithm, duplicated agents were transferred to the point, where the second, third, and fourth cells were created in order, after the first cell was made, and the agents were engineered to search the shortest path to each cell, and then find the most efficient element through competition.

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Clear cell odontogenic carcinoma: a mini review

  • Kim, Young Hwan;Seo, Eun Jin;Park, Jae Kyung;Jang, Il Ho
    • International Journal of Oral Biology
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    • v.44 no.3
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    • pp.77-80
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    • 2019
  • Clear cell odontogenic carcinoma (CCOC), a very rare neoplasm located mostly in the mandible, has been regarded as a benign tumor. However, due to the accumulation of case reports, CCOC has been reclassified as a malignant entity by the World Health Organization. Patients with CCOC present with regional swelling and periodontal indications with variable pain, often remaining misdiagnosed for a long period. CCOC has slow growth but aggressive behavior, requiring radical resection. Histologic analysis revealed the monophasic, biphasic, and ameloblastic types of CCOC with clear cells and a mixed combination of polygonal and palisading cells. At the molecular level, CCOC shows the expression of cytokeratin and epithelial membrane antigen, along with markers that assign CCOC to the sarcoma family. At the genetic level, Ewing sarcoma breakpoint region 1-activating transcription factor 1 fusion is regarded as the key feature for identification. Nevertheless, the scarcity of cases and dependence on histological data delay the development of an efficient therapy. Regarding the high recurrence rate and the potential of distant metastasis, further characterization of CCOC is necessary for an early and accurate diagnosis.

Genotoxicity and Interference with Cell Cycle Activities by an Ethanolic Extract from Thai Plumbago indica Roots in Human Lymphocytes in vitro

  • Thitiorul, Sumon;Ratanavalachai, Treetip;Tanuchit, Sermkiat;Itharat, Arunporn;Sakpakdeejaroen, Intouch
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.4
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    • pp.2487-2490
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    • 2013
  • In Thai traditional medicine, Plumbago indica or Jetamul-Pleung-Dang in Thai is known to have health benefit especially for anti-inflammatory, antibacterial, and antitumor activities. However, the mechanisms of its action are still uncertain. One of which might be genotoxic effects. In the present study, we investigated the genotoxicity of an ethanolic extract of Plumbago indica root (EEPIR) by sister chromatid exchange (SCE) assay in human lymphocytes. Results have shown that all treatments with EEPIR ($12.5-100{\mu}g/ml$) could induce cell cycle delay as shown by significant increase in the number of metaphase cells in the first cell cycle but neither in the second nor the third cell cycle. Only at concentrations of 25, 50, and $100{\mu}g/ml$ were SCE levels significantly increased above that of the control (p<0.05). EEPIR at a concentration of $500{\mu}g/ml$ induced cell death as few mitotic cells were shown. Accordingly, EEPIR ($25-100{\mu}g/ml$) is genotoxic in human lymphocytes and cytotoxic at concentrations of ${\geq}500{\mu}g/ml$ in vitro. Therefore, these activities of the EEPIR could serve its potential therapeutic effects, especially as an anticancer agent. Further study of EEPIR in vivo is now needed to support this in vitro evidence.

Traffic Flow Control of B-NT for Prevention of Congestion in B-ISDN UNI (B-ISDN UNI에서 폭주를 예방하기 위한 B-NT의 트래픽 흐름 제어)

  • 이숭희;최흥문
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.6
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    • pp.1085-1094
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    • 1994
  • We propose a traffic flow control scheme of B-NT with temporary cell buffering and selective cell discarding to prevent congestion state of the network nodes in B-ISDN systems to reduce or suppress output cell strams towards T interface. We define the states of the network nodes as normal, pre-congestion, and congestion. In a pre-congestion state, the loss-sensitive traffic is temporarily buffered to slow down the rate of the output traffic streams. In a congestion state, the delay-sensitive traffic is selectively discarded to suppress the output traffic streams as possible in addition to the cell buffering. We model the input cell streams and the states of the network nodes with Interrupted Bernoulli Process and 3-state Markov chain to analyze the performance of the proposed scheme in the B-NT system. The appropriate size of the cell buffer is explored by means of simulation and the influence on the performance of the proposed scheme by the network node state is discussed. As results, more than 2,00 cells of buffer size is needed for the control of medium of lower than the medium, degree of congestion occurrence in the network node while the control of high degree of congestion occurrence is nearly impossible.

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An Efficient Broadcast Technique for Vehicular Networks

  • Ho, Ai Hua;Ho, Yao H.;Hua, Kien A.;Villafane, Roy;Chao, Han-Chieh
    • Journal of Information Processing Systems
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    • v.7 no.2
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    • pp.221-240
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    • 2011
  • Vehicular networks are a promising application of mobile ad hoc networks. In this paper, we introduce an efficient broadcast technique, called CB-S (Cell Broadcast for Streets), for vehicular networks with occlusions such as skyscrapers. In this environment, the road network is fragmented into cells such that nodes in a cell can communicate with any node within a two cell distance. Each mobile node is equipped with a GPS (Global Positioning System) unit and a map of the cells. The cell map has information about the cells including their identifier and the coordinates of the upper-right and lower-left corner of each cell. CB-S has the following desirable property. Broadcast of a message is performed by rebroadcasting the message from every other cell in the terrain. This characteristic allows CB-S to achieve an efficient performance. Our simulation results indicate that messages always reach all nodes in the wireless network. This perfect coverage is achieved with minimal overhead. That is, CB-S uses a low number of nodes to disseminate the data packets as quickly as probabilistically possible. This efficiency gives it the advantage of low delay. To show these benefits, we give simulations results to compare CB-S with four other broadcast techniques. In practice, CB-S can be used for information dissemination, or to reduce the high cost of destination discovery in routing protocols. By also specify the radius of affected zone, CB-S is also more efficient when broadcast to a subset of the nodes is desirable.

Analysis of Cell Stream Scheme and Service Transmission using Time-Stamp Method in the Wireless ATM (무선 ATM에서 타임스탬프 방식을 이용한 셀 스트림 구조와 서비스전송 해석)

  • Kim, Jeong-Ho
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.8
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    • pp.2179-2187
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    • 1999
  • To privide multimedia mobile communication services for the users in scattered locations, the application ATM cells efficiently in wireless communications, it is effective to the use TDMA method. However, it is necessary to have methods to compensate the CDV(cell delay variation) caused by the difference between TDMA-ATM and cell stream multiplexing of the users. This paper optimizes the cell control time(Tc) when VBR traffic inputs have MMPP by applying CDV characteristics of time stamp method, which has the most advantages among compensation methods of CDV. This paper suggests a cell stream multiplex method employing time stamp techniques to reduce CDV for wireless suggest method shows that CDV distribution and cell stream multiples rangd can be controlled to 1.2${\times}$Tc which reduced over the VBR service in the TDMA-WATM transmission. This paper also presents evaluation of the suggested architecture obtained simulation.

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N-Acetyl-D-Glucosamine Kinase Interacts with Dynein-Lis1-NudE1 Complex and Regulates Cell Division

  • Sharif, Syeda Ridita;Islam, Md. Ariful;Moon, Il Soo
    • Molecules and Cells
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    • v.39 no.9
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    • pp.669-679
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    • 2016
  • N-acetyl-D-glucosamine kinase (GlcNAc kinase or NAGK) primarily catalyzes phosphoryl transfer to GlcNAc during amino sugar metabolism. Recently, it was shown NAGK interacts with dynein light chain roadblock type 1 (DYNLRB1) and upregulates axo-dendritic growth, which is an enzyme activity-independent, non-canonical structural role. The authors examined the distributions of NAGK and NAGK-dynein complexes during the cell cycle in HEK293T cells. NAGK was expressed throughout different stages of cell division and immunocytochemistry (ICC) showed NAGK was localized at nuclear envelope, spindle microtubules (MTs), and kinetochores (KTs). A proximity ligation assay (PLA) for NAGK and DYNLRB1 revealed NAGK-dynein complex on nuclear envelopes in prophase cells and on chromosomes in metaphase cells. NAGK-DYNLRB1 PLA followed by Lis1/NudE1 immunostaining showed NAGK-dynein complexes were colocalized with Lis1 and NudE1 signals, and PLA for NAGK-Lis1 showed similar signal patterns, suggesting a functional link between NAGK and dynein-Lis1 complex. Subsequently, NAGK-dynein complexes were found in KTs and on nuclear membranes where KTs were marked with CENP-B ICC and nuclear membrane with lamin ICC. Furthermore, knockdown of NAGK by small hairpin (sh) RNA was found to delay cell division. These results indicate that the NAGK-dynein interaction with the involvements of Lis1 and NudE1 plays an important role in prophase nuclear envelope breakdown (NEB) and metaphase MT-KT attachment during eukaryotic cell division.

Performances of wireless ATM cell transmission with partial concatenated coding (무선 ATM셀 전송을 위한 부분 연쇄 부호화 기법의 성능분석)

  • 이진호;김태중;이동도;안재영;황금찬
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.9
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    • pp.2014-2026
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    • 1997
  • In this paper, the performances of wireless asynchronous transfer mode (ATM) cell transmission in mobile work are analyzed. We adopt 16Star QAM as amodulation technique in wireless channel and considered Reed-Solomon, convolutional, and concatenated coding to improve the error rate performances, and also proposed the Partial Concatenated Coding (PCC) technique as UEP(unequal error protection) code for efficient transmission of ATM cell in the air interface. We consider Doppler's effect, Rician fading, and diversity technique of maximal-ratio combining (MRC) for mobile channel model. For performance measure, we analyze bit error rate, ATM cell loss probability, ATM cell error probability, and network performances of ATM cell transmission delay and throughput. The numerical results show that the adoption of PCC is a prospective way for the evolution of future wireless ATM network on mobile environment.

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A study of the development of a simple driver for the Pockels cell Q-switch and Its characteristics (단순화된 Pockels cell Q-switch용 구동기 개발 및 특성에 관한 연구)

  • Park, K.R.;Joung, J.H.;Hong, J.H.;Kim, B.G.;Moon, D.S.;Kim, W.Y.;Kim, H.J.;Cho, J.S.
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.2116-2118
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    • 2000
  • In the technique of Q-switching, very fast electronically controlled optical shutters can be made by using the electro-optic effect in crystals or liquids. The driver for the Pockels cell must be a high-speed, high-voltage switch which also must deliver a sizeable current. Common switching techniques include the use of vacuum tubes, cold cathode tubes, thyratrons, SCRs, and avalanche transistors. Semiconductor devices such as SCRs, avalanche transistors, and MOSFETs have been successfully employed to drive Pockels cell Q-switch. In this study, a simple driver for the Pockels cell Q-switch was developed by using SCRs, pulse transformer and TTL ICs. The Pockels cell Q-switch which was operated by this driver was employed in pulsed Nd:YAG laser system to investigate the operating characteristics of this Q-switch. And we have investigated the output characteristics of this Q-switch as a function of the Q-switch delay time to Xe flashlamp current on.

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Effects of Pahs and Pcbs and Their Toxic Metabolites on Inhibition of Gjic and Cell Proliferation in Rat Liver Epithelial Wb-F344 Cells

  • Miroslav, Machala;Jan, Vondracek;Katerina, Chramostova;Lenka, Sindlerova;Pavel, Krcmar;Martina, Pliskova;Katerina, Pencikova;Brad, Upham
    • Environmental Mutagens and Carcinogens
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    • v.23 no.2
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    • pp.56-62
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    • 2003
  • The liver progenitor cells could form a potential target cell population fore both tumor-initiating and -promoting chemicals. Induction of drug-metabolizing and antioxidant enzymes, including AhR-dependent CYP1A1, NQO-1 and AKR1C9, was detected in the rat liver epithelial WB-F344 "stem-like" cells. Additionally, WB-F344 cells express a functional, wild-type form of p53 protein, a biomarker of genotoxic events, and connexin 43, a basic structural unit of gap junctions forming an important type of intercellular communication. In this cellular model, two complementary assays have been established for detection of the modes of action associated with tumor promotion: inhibition of gap junctional intercellular communication (GJIC) and proliferative activity in confluent cells. We found that the PAHs and PCBs, which are AhR agonists, released WB-F344 cells from contact inhibition, increasing both DNA synthesis and cell numbers. Genotoxic effects of some PAHs that lead to apoptosis and cell cycle delay might interfere with the proliferative activity of PAHs. Contrary to that, the nongenotoxic low-molecular-weight PAHs and non-dioxin-like PCB congeners, abundant in the environment, did not significantly affect cell cycle and cell proliferation; however both groups of compounds inhibited GJIC in WB-F344 cells. The release from contact inhibiton by a mechanism that possibly involves the AhR activation, inhibition of GJIC and genotoxic events induced by environmental contaminants are three important modes of action that could play an important role in carcinogenic effects of toxic compounds. The relative potencies to inhibit GJIC, to induce AhR-mediated activity, and to release cells from contact inhibition were determined for a large series of PAHs and PCBs and their metabolites. In vitro bioassays based on detection of events on cellular level (deregulation of GJIC and/or proliferation) or determination of receptor-mediated activities in both ?$stem-like^{\circ}{\times}$ and hepatocyte-like liver cellular models are valuable tools for detection of modes of action of polyaromatic hydrocarbons. They may serve, together with concentration data, as a first step in their risk assessment.

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