• Title/Summary/Keyword: Cell entry

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Design and Implementation of Location Utility Service for LBS

  • Kim, K.S.;Kim, J.C.;Lee, J.W.;Park, J.H.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.849-851
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    • 2003
  • A location-based service or LBS in a cellular telephone network is a service provided to the subscriber based on his current geographic location. This position can be known by user entry or a GPS receiver that he carries with him, but most often the term implies the use of a function built into the cell network that uses the known geographic coordinates of the base stations through which the communication takes place. One implication is that knowledge of the coordinates is owned and controlled by the network operator, and not by the end user. Location utility service provides two kinds of functions, geocoder and reverse geocoder. Geocoder converts an address into a coordinate and reverse geocoder changes a coordinate into an address. Because location utility service is the first step to progress LBS, various servises such as directory, routing, presentation, and etc require to access that. In this paper, we will describe the architecture of LBS platform and the concept and the role of location utility service.

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Evaluation of the Potential Risk of Porcine Endogenous Retrovirus (PERV) Infection in Nude Mice

  • Bae, Eun-Hye;Jung, Yong-Tae
    • Journal of Microbiology and Biotechnology
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    • v.21 no.4
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    • pp.387-390
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    • 2011
  • Nude mice (BALB/c) were grafted with human 293 cells and PERV (porcine endogenous retrovirus)-IRES-EGFP (a packageable retroviral vector plasmid containing an internal ribosome entry site-enhanced green fluorescent protein)-producing pig PK15 cells in order to determine whether the pig cells could transmit PERV-IRES-EGFP to mice and human 293 cells in vivo. None of the transplanted human 293 cell lines were infected by PERV, but PCR analysis identified PERV-B provirus integration into both the heart and salivary gland of the inoculated nude mice. Our data indicate that hearts and salivary glands can be used to identify PERV-B receptors.

Enhancement of Gene Delivery to Cancer Cells by a Retargeted Adenovirus

  • Oh Kwang Seok;Engler Jeffrey A.;Joung In Sil
    • Journal of Microbiology
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    • v.43 no.2
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    • pp.179-182
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    • 2005
  • The inefficiency of in vivo gene transfer using currently available vectors reflects a major hurdle in cancer gene therapy. Both viral and non-viral approaches that improve gene transfer efficiency have been described, but suffer from a number of limitations. Herein, a fiber-modified adenovirus, carrying the small peptide ligand on the capsid, was tested for the delivery of a transgene to cancer cells. The fiber-modified adenovirus was able to mediate the entry and expression of a $\beta$-galactosidase into cancer cells with increased efficiency compared to the unmodified adenovirus. Particularly, the gene transfer efficiency was improved up to 5 times in OVCAR3 cells, an ovarian cancer cell line. Such transduction systems hold promise for delivering genes to transferrin receptor overexpressing cancer cells, and could be used for future cancer gene therapy.

Analysis of the hematopoiesis process in mammalian bone using homotopy perturbation method

  • Akano, Theddeus T.;Nwoye, Ephraim O.;Adeyemi, Segun
    • Biomaterials and Biomechanics in Bioengineering
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    • v.5 no.1
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    • pp.51-64
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    • 2020
  • In this study, the mathematical model that describes blood cell development in the bone marrow (i.e., hematopoiesis) has been studied via the Homotopy Perturbation Method (HPM). The results from the present work compared very well with the numerical solutions from published literature. This work has shown that the HPM is viable for solving delay differential equations born from hematopoiesis problem. The influence of the proliferating cells loss rate, time delay rate and the phase re-entry rate on the population densities of both the proliferating and resting cells were also determined through the underlined procedure.

Decentralized Frequency Allocation Scheme in Vehicle-mounted Mobile Relay System (차량 탑재형 이동 중계기의 분산 주파수 분할 기법)

  • Shin, Yun-Jae;Lee, Jung-Ryun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.7C
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    • pp.592-600
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    • 2012
  • In this paper, we proposed that decentralized frequency allocation scheme(DFAS) without network entry procedure between relays in mobile relay system. Frequency Indicator(FI) signal which is the reference signal of frequency division of each relay and Energy Detection(ED) region are defined. In addition, the mobile connected to the relay transmits the FI signal to neighbor relays in order to facilitate communication between relays. Finally, by using this scheme, the cell throughput improvement is confirmed.

A Blood-brain Barrier Permeable Derivative of 5-Fluorouracil: Preparation, Intracellular Localization, and Mouse Tissue Distribution

  • Im, Jung-Kyun;Biswas, Goutam;Kim, Wan-Il;Kim, Kyong-Tai;Chung, Sung-Kee
    • Bulletin of the Korean Chemical Society
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    • v.32 no.3
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    • pp.873-879
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    • 2011
  • 5-Fluorouracil (5-FU), an anticancer agent was covalently attached to the recently developed sorbitol-based G8 transporter, and the conjugate (7) with FITC was found to have an affinity toward mitochondria and to readily cross BBB to gain an entry into mouse brain. Measured by $IC_{50}$, the conjugate (9) without the fluorophore showed enhanced cytotoxic activity toward two types of multidrug-resistant cell lines. These results strongly suggest that the sorbitol-based G8 transporter can be utilized as a good CNS delivery vector.

Design and Implementation of Providing Conditional Access Broadcasting Service System (수신 제한된 방송 서비스 제공 시스템 설계 및 구현)

  • Kim, Dong-Ok;Shin, Ik-Ryong
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.8 no.2
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    • pp.64-71
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    • 2009
  • In this paper, This thesis is cell phone for make CAS service be for hand joining broadcasting Create a way CAS Chip. PerSam issue card inside use Seed Key and algorithm make CID Key and record CAS Chip. PerSam member Card inside use Seed Key and algorithm make Subscriber Key after include Subscriber. Key CAS Chip for record CID Key register EMM. make CAS CHIP in accordance with issue CAS Chip. broadcast service entry be for hand treatment so make low bandwidth for joining massage and make increase a member.

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A Study on the Enhancement of Detection Performance of Space Situational Awareness Radar System

  • Choi, Eun-Jung;Lee, Jonghyun;Cho, Sungki;Moon, Hyun-Wook;Yum, Jea-Myong;Yu, Jiwoong;Park, Jang-Hyun;Jo, Jung Hyun
    • Journal of Astronomy and Space Sciences
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    • v.35 no.4
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    • pp.279-286
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    • 2018
  • Radar sensors are used for space situational awareness (SSA) to determine collision risk and detect re-entry of space objects. The capability of SSA radar system includes radar sensitivity such as the detectable radar cross-section as a function of range and tracking capability to indicate tracking time and measurement errors. The time duration of the target staying in a range cell is short; therefore, the signal-to-noise ratio cannot be improved through the pulse integration method used in pulse-Doppler signal processing. In this study, a method of improving the signal-to-noise ratio during range migration is presented. The improved detection performance from signal processing gains realized in this study can be used as a basis for comprehensively designing an SSA radar system.

Synthesis and $BK_{ca}$-channel Opening Activity of Substituted l0-H-Benzo[4-5]furo[3,2-b]indole-carboxylic acids

  • Gormemis, Ahmet-Erkam;Soo, Ha-Tal;Park, Chul-Seung;Kim, Yong-Chul
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.188.2-188.2
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    • 2003
  • Large-conductance $Ca^{2+}$ activated potassium channels $(BK_{ca})$ are widely distributed and play key roles in various cell functions. In nerve cells, B $K_{ca}$ channels shorten the duration of action potentials and block $Ca^{2+}$ entry thereby repolarizing excitable cells after excitation. $(BK_{ca})$ channel opening has been postulated to confer neuroprotection during stroke and has attracted attention as a means for therapeutic intervention in asthma, hypertension, convulsion, and traumatic brain injury. (omitted)

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Oxidized Low-density Lipoprotein- and Lysophosphatidylcholine-induced $Ca^{2+}$ Mobilization in Human Endothelial Cells

  • Kim, Moon-Young;Liang, Guo-Hua;Kim, Ji-Aee;Choi, Soo-Seung;Choi, Shin-Ku;Suh, Suk-Hyo
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.1
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    • pp.27-32
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    • 2009
  • The effects of oxidized low-density lipoprotein(OxLDL) and its major lipid constituent lysophosphatidylcholine(LPC) on $Ca^{2+}$ entry were investigated in cultured human umbilical endothelial cells(HUVECs) using fura-2 fluorescence and patch-clamp methods. OxLDL or LPC increased intracellular $Ca^{2+}$ concentration($[Ca^{2+}]_i$), and the increase of $[Ca^{2+}]_i$ by OxLDL or by LPC was inhibited by $La^{3+}$ or heparin. LPC failed to increase $[Ca^{2+}]_i$ in the presence of an antioxidant tempol. In addition, store-operated $Ca^{2+}$ entry(SOC), which was evoked by intracellular $Ca^{2+}$ store depletion in $Ca^{2+}$-free solution using the sarcoplasmic reticulum $Ca^{2+}$ pump blocker, 2, 5-di-t-butyl-l,4-benzohydroquinone(BHQ), was further enhanced by OxLDL or by LPC. Increased SOC by OxLDL or by LPC was inhibited by U73122. In voltage-clamped cells, OxLDL or LPC increased $[Ca^{2+}]_i$ and simultaneously activated non-selective cation(NSC) currents. LPC-induced NSC currents were inhibited by 2-APB, $La^{3+}$ or U73122, and NSC currents were not activated by LPC in the presence of tempol. Furthermore, in voltage-clamped HUVECs, OxLDL enhanced SOC and evoked outward currents simultaneously. Clamping intracellular $Ca^{2+}$ to 1 ${\mu}M$ activated large-conductance $Ca^{2+}$-activated $K^+(BK_{ca})$ current spontaneously, and this activated $BK_{ca}$ current was further enhanced by OxLDL or by LPC. From these results, we concluded that OxLDL or its main component LPC activates $Ca^{2+}$-permeable $Ca^{2+}$-activated NSC current and $BK_{ca}$ current simultaneously, thereby increasing SOC.