• International Journal of Internet, Broadcasting and Communication
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• 제15권1호
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• pp.1-7
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• 2023

TCP is considered a major candidate transport protocol even for constrained IoT networks due to its ability to integrate into the existing network infrastructures. Since TCP implementations such as uIP TCP often allow only a single TCP segment per connection to be unacknowledged at any given time due to resource constraints, the congestion control relies only on RTO management. In our previous work, to address the problem that uIP TCP performs poorly particularly when a radio duty cycling mechanism is enabled and the hidden terminal problem is severe, we proposed a RTO scheme for uIP TCP and validated the performance through Cooja simulation. In this study, we investigate the effect of other factors that were not considered in our previous work. More specifically, the effect of traffic intensity, the degree of the hidden terminal problem, and RDC is investigated by varying the offered load and the transmission range, and the RDC channel check rate. Simulation results imply that we need to further investigate how to improve TCP performance when the radio duty cycling mechanism is used.

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1197-1205
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• 2013

Urokinase (uPA) and its receptor (uPAR) play an important role in tumor growth and metastasis. Targeting the excessive activation of this system as well as the proliferation of the tumor vascular endothelial cell would be expected to prevent tumor neovasculature and halt the tumor development. In this regard, the amino-terminal fragment (ATF) of urokinase has been confirmed as effective to inhibit the proliferation, migration, and invasiveness of cancer cells via interrupting the interaction of uPA and uPAR. Previous studies indicated that ATF expressed in Escherichia coli was mainly contained in inclusion bodies and also lacked posttranslational modifications. In this study, the biologically active and soluble ATF was cloned and expressed in Pichia pastoris. The recombinant protein was purified to be homogenous and confirmed to be biologically active. The yield of the active ATF was about 30 mg/l of the P. pastoris culture medium. The recombinant ATF (rATF) could efficiently inhibit angiogenesis, endothelial cell migration, and tumor cell invasion in vitro. Furthermore, it could inhibit in vivo xenograft tumor growth and prolong the survival of tumor-bearing mice significantly by competing with uPA for binding to cell surfaces. Therefore, P. pastoris is a highly efficient and cost-effective expression system for large-scale production of biologically active rATFs for potential therapeutic application.

• 약학회지
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• 제52권2호
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• pp.125-130
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• 2008

The long terminal repeat (LTR) of retroviral DNA genome plays an important role in the integration process by providing substrate recognition site for viral integrase (IN). The dinucleotide CA near the 3'-end of the LTR termini is completely conserved among retoviruses. In order to study specificity of interaction between prototype foamy virus (PFV) IN and its U5 LTR DNA, the effect of mutagenesis of the CA sequence was investigated by studying reactivity of PFV IN to the mutant LTR substrates. Replacement of only the C or the A allowed 60 to 100% of the reactivity of the wild type LTR substrate. In addition, replacement of the C and the A showed 50 to 80% of the reactivity of the wild type LTR substrate, indicating that PFV IN has less specificity on the conserved CA sequence when it is compared to the other retroviral INs. Therefore it is suggested that PFV IN is less dependent on the conserved sequence of LTR termini for its enzymatic reaction.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1596-1602
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• 2010

The government have plans to improve the railway transport capacity and transport hub for the sustainable national transport and logistics system. Specially, there are much efforts to improve transportation capacity such as high speed transportation of rail freight, enlargement of BT train, development of double stack train, etc. between railway transport hubs. If the transport capacity between railway logistics hubs is increased as planned, we must increase the handling capacity of railway hub terminals. But there are limits to enlarge the terminal infrastructure because of investment scale, location circumstances and urban development plans. To ensure the capacity, with the minimum required enlargement of infrastructure, it is necessary to extremely increase the efficiency of terminal operations. For improving the efficiency, we have to introduce the efficient terminal operation systems based on u-IT and operation optimize technologies. In this paper, we analyse the issues and problems of railway terminals(including ICD) and suggest the concept of intelligent railway terminal and the construction components of technology.

• Clinical and Experimental Pediatrics
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• 제52권8호
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• pp.843-850
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• 2009

A recent High Court's decision regarding the withdrawal of life supporting medical treatment (artificial ventilator) from an elderly female patient in the terminal stage has opened up a new era of the "euthanasia dispute" in Korea. With this decision, the legitimate withdrawal of life supporting treatment became possible under certain conditions and the Korean Medical Association is working toward the establishment of practical guidelines for the terminal-stage patients. However, there are still very few debates on the cases of pediatric patients in the terminal stage or suffering from fatal diseases. For pediatric patients, the core principle of autonomy and following procedure of "advance directives" are hardly kept due to the immaturity of the patients themselves. Decisions for their lives usually are in the hands of the parents, which may often bring out tragic disputes around "child abuse", especially in Korea where parents have exclusive control of the destiny of their children. Some developed countries such as the U.S.A., the U.K. and Canada have already established guidelines or a legal framework for ensuring the rights of the healthcare system regarding children suffering from severe illness, permitting the withdrawal of Life supporting medical treatment (LSMT) in very specific conditions when the quality of life of the children is severely threatened. For the protection of the welfare and interest of the children, we should discuss this issue and develop guidelines for the daily practice of pediatricians.

• Molecules and Cells
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• 제45권8호
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• pp.522-530
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• 2022

Transposable elements (TEs) account for approximately 45% of the human genome. TEs have proliferated randomly and integrated into functional genes during hominoid radiation. They appear as right-handed B-DNA double helices and slightly elongated left-handed Z-DNAs. Human endogenous retrovirus (HERV) families are widely distributed in human chromosomes at a ratio of 8%. They contain a 5'-long terminal repeat (LTR)-gag-pol-env-3'-LTR structure. LTRs contain the U3 enhancer and promoter region, transcribed R region, and U5 region. LTRs can influence host gene expression by acting as regulatory elements. In this review, we describe the alternative promoters derived from LTR elements that overlap Z-DNA by comparing Z-hunt and DeepZ data for human functional genes. We also present evidence showing the regulatory activity of LTR elements containing Z-DNA in GSDML. Taken together, the regulatory activity of LTR elements with Z-DNA allows us to understand gene function in relation to various human diseases.

• 한국자원식물학회지
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• 제17권3호
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• pp.289-296
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• 2004

더덕의 뿌리로부터 aluminum스트레스와 관련이 있는 aluminum induce protein(ClAIP)유전자를 분리하였다. ClAIP 유전자의 염기서열를 분석한 결과 906 bp 길이로, 236개의 아미노산으로 번역되는 711bp의 ORF를 가지고 있으며, A. marina(84%), G. hirsutum(84%), V. radiata(83%), A. thaliana(80%), B. hapus(78%), T. aestivum(68%) 등 다른 식물에서 밝혀져 있는 aluminum induce protein과 높은 상동성을 나타내었고, N-terminal에는 Asn synthetase영역이 존재하고 있다. 더덕에서 분리한 aluminum induced protein(ClAIP)을 aluminum처리 농도와 시간에 따른 ClAIP유전자의 발현양상을 알아보고자 50uM $Al^{3+}$ 를 처리 후 시간대별로 RT-PCR을 수행한 결과 시간이 지남에 따라 ClAIP유전자의 발현이 증가되는 것으로 나타났다 중금속, 염 , 온도에 대한 유전자의 발현양상을 조사하기 위 해 50uM CdCl,$_2$, 20 uM CuSO$_4$, 50uM Fe$_2$O$_3$, 100 uM NaCl를 2일과 42$^{\circ}C$에서 4시간 처리 후 발현량을 조사한 결과 카드뮴(Cd)에 대해서 특이적으로 반응하는 것으로 나타났다.

• 산업공학
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• 제1권1호
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• pp.49-62
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• 1988

This paper deals with the case study that determines the best operating system of a container terminal using computer simulation techniques. For the simulation, SIMAN simulation language is used. The simulation model developed circumvents the dimensional restrictions imposed by the SIMAN package. Non-terminating simulation experiments are conducted for the 90 days' work on the basis of operation practices of real terminals.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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• pp.37-37
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• 1999

The influenza A viruses which are the most severe and common among the influenza viruses have 8 segmented RNA genomes Each RNA segment has highly conserved 3' and 5' terminal sequence except a single U\longrightarrowC variation especially in the 4 position of the 3' terminal of the 3 segments encoding own RNA polymerase.(omitted)

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2004년도 춘계 학술발표대회 논문집
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• pp.8-9
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• 2004