• 전자공학회논문지SC
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• 제44권3호
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• pp.58-63
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• 2007

GPS 신호는 수신 전력이 매우 낮으며, 민간용 신호의 경우에는 신호 구조가 잘 알려져 있어서 고의적 혹은 비고의적인 간섭에 취약하다. 많은 간섭 제거 기법이 연구되고 있으며 그 중에서 ATF가 상관전 처리 기법으로 널리 사용되고 있다. 그러나 ATF는 노치 폭과 관련된 설계 변수가 없어서 간섭을 제거하더라도 주변 주파수에 스펙트럼 손실을 가져온다. 반면 IIR 노치 필터는 노치 폭과 관련된 설계 변수가 있어서 CW 간섭에 대하여 매우 예리한 노치를 생성할 수 있으므로 스펙트럼 손실을 줄일 수 있다. 본 논문에서는 적응 알고리즘을 적용할 수 있는 구조의 IIR 노치 필터를 제시하고, 소프트웨어 신호발생기와 실제 측정치를 이용하여 성능을 평가하였으며, IIR 필터의 SNR 손실이 FiR 필터에 비하여 5dB 정도 작은 것을 확인하였다.

• 생명과학회지
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• 제30권3호
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• pp.285-290
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• 2020

구제역바이러스(FMDV)는 Picornaviridae 과의 Aphthovirus 속의 한 종류이며, 야생과 가축의 소와 돼지에 감염한다. FMDV는 감염 조직에서 중증의 염증반응을 포함한 다양한 임상적 증후들을 일으킨다. FMDV 게놈 RNA는 약 8.3 kb 길이의 양성-단일 가닥을 가지고 있으며, 하나의 긴 단백질 번역틀(ORF)을 만든다. 이 ORF는 바이러스의 단백질가수분해효소에 의해서 구조단백질과 비구조단백질로 나누어진다. FMDV의 FMDV 2C 단백질은 FMDV 유전자에서 만들어지는 비구조단백질로서 염증과 세포사를 포함한 FMD 병리 과정과 바이러스 복제에서 중요한 역할을 한다. 이 연구에서 우리는 FMDV 2C가 염증 유도 사이토카인인 tumor necrosis factor alpha (TNFα)의 세포내 발현을 유도하는 가능성을 검토하였다. FMDV 2C의 돼지 세포인 IBRS-2 세포내 발현은 TNFα의 유전자 발현 조절 부위인 프로모터의 활성화를 이용하여 전사수준에서 TNFα의 mRNA와 단백질 생성을 증가시켰다. 추가적으로, 소포체 스트레스를 감소시키는 화학물질인 4-phenylbutyric acid (4-PBA) 처리는 FMDV 2C에 의해 유도된 TNFα 발현을 감소시켰다. 소포체 스트레스 반응을 매개하는 전사인자의 한 종류인 ATF4는 TNFα 프로모터의 활성을 유도하고, TNFα의 mRNA와 단백질 발현을 증가시켰다. 하지만, ATF4의 기능 결핍 돌연변이체 단백질의 발현은 FMDV 2C에 의한 TNFα 생성을 유도하지 못하였다. 이들 결과들은 FMDV FMDV 2C 단백질이 ATF4-매개 TNFα 발현을 통해 임상적 염증반응을 증가시키고, 이는 소포체 스트레스의 유도와 연관되어있음을 제시한다.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2008년도 춘계학술발표회
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• pp.148-149
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• 2008

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2008년도 춘계학술발표회
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• pp.150-151
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• 2008

• Tribology and Lubricants
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• 제21권3호
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• pp.142-148
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• 2005

In order to improve the fuel economy by design change of automatic transmission, various technologies such as increased shift stages, slip control of lock-up clutch and compact and low-weight design have been developed. And also many OEMs have developed their own ATFs as a part of these automatic transmissions. In this study, to investigate the effects of ATF characteristics on fuel economy, we got the worldwide OEM ATFs and made some reference fluids. And physical properties, frictional characteristics and fuel economy using dynamometer test for these fluids were evaluated. From the investigation, it was found that viscosities of ATFs are correlated with fuel economy in dynamometer test and reducing the viscosities made it possible to obtain fuel economy.

• Journal of Ginseng Research
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• 제41권2호
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• pp.127-133
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• 2017

Background: Ginsenoside Rc (G-Rc) is one of the major protopanaxadiol-type saponins isolated from Panax ginseng, a well-known medicinal herb with many beneficial properties including anticancer, anti-inflammatory, antiobesity, and antidiabetic effects. In this study, we investigated the effects of G-Rc on inflammatory responses in vitro and examined the mechanisms of these effects. Methods: The in vitro inflammation system used lipopolysaccharide-treated macrophages, tumor necrosis $factor-{\alpha}/interferon-{\gamma}-treated$ synovial cells, and HEK293 cells transfected with various inducers of inflammation. Results: G-Rc significantly inhibited the expression of macrophage-derived cytokines, such as tumor necrosis $factor-{\alpha}$ and $interleukin-1{\beta}$. G-Rc also markedly suppressed the activation of TANK-binding kinase $1/I{\kappa}B$ kinase ${\varepsilon}/interferon$ regulatory factor-3 and p38/ATF-2 signaling in activated RAW264.7 macrophages, human synovial cells, and HEK293 cells. Conclusion: G-Rc exerts its anti-inflammatory actions by suppressing TANK-binding kinase $1/I{\kappa}B$ kinase ${\varepsilon}/interferon$ regulatory factor-3 and p38/ATF-2 signaling.

• The Korean Journal of Physiology and Pharmacology
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• 제26권6호
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• pp.469-478
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• 2022

WNT signaling plays an important role in cardiac development, but abnormal activity is often associated with cardiac hypertrophy, myocardial infarction, remodeling, and heart failure. The effect of WNT signaling on regulation of atrial natriuretic peptide (ANP) secretion is unclear. Therefore, the purpose of this study was to investigate the effect of Wnt agonist 1 (Wnta1) on ANP secretion and mechanical dynamics in beating rat atria. Wnta1 treatment significantly increased atrial ANP secretion and pulse pressure; these effects were blocked by U73122, an antagonist of phospholipase C. U73122 also abolished the effects of Wnta1-mediated upregulation of protein kinase C (PKC) β and γ expression, and the PKC antagonist Go 6983 eliminated Wnta1-induced secretion of ANP. In addition, Wnta1 upregulated levels of phospho-transforming growth factor-β activated kinase 1 (p-TAK1), TAK1 banding 1 (TAB1) and phospho-activating transcription factor 2 (p-ATF2); these effects were blocked by both U73122 and Go 6983. Wnta1-induced ATF2 was abrogated by inhibition of TAK1. Furthermore, Wnta1 upregulated the expression of T cell factor (TCF) 3, TCF4, and lymphoid enhancer factor 1 (LEF1), and these effects were blocked by U73122 and Go 6983. Tak1 inhibition abolished the Wnta1-induced expression of TCF3, TCF4, and LEF1 and Wnta1-mediated ANP secretion and changes in mechanical dynamics. These results suggest that Wnta1 increased the secretion of ANP and mechanical dynamics in beating rat atria by activation of PKC-TAK1-ATF2-TCF3/LEF1 and TCF4/LEF1 signaling mainly via the WNT/Ca²⁺ pathway. It is also suggested that WNT-ANP signaling is implicated in cardiac physiology and pathophysiology.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2578-2590
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• 2023

In this work, a 24-month two-batch fuel management strategy for the APR1400 using LEU + has been investigated, where enrichments of 5.9 and 5.2 w/o are utilized in lieu of the conventional 4-5 w/o UO₂ fuel. In addition, an Accident Tolerant Fuel (ATF) clad based on the swaging technology is applied to APR1400 fuel assemblies. In this special ATF clad design, both outer and inner SS316 layers protect the conventional zircaloy clad. Erbia (Er₂O₃) is introduced as a burnable absorber with two-fold goals to lower the critical boron concentration in the long-cycle LEU + loaded core as well as to handle the LEU + fuel in the existing front-end fuel facilities without renewing the license. Two types of fuel assemblies with different loading of gadolinia (Gd₂O₃) are considered to control both the reactivity and the core radial power distribution. The erbia burnable absorber is uniformly admixed with UO₂ in all fuel pins except for the gadolinia-bearing ones. In this study, two core designs were devised with different erbia loading, and core performance and safety parameters were evaluated for each case in comparison with a core design without any burnable absorbers. The core analysis was done using the two-step method. First, cross-sections are generated by the SERPENT 2 Monte Carlo code, and the 3-D neutronic analysis is performed with an in-house multi-physics nodal code KANT.

• 한국미생물·생명공학회지
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• 제38권4호
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• pp.442-447
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• 2010

본 연구에서는 마늘성분 allicin에 의한 항암 기전 및 화학적 암 예방법의 분자 생물학적 기전을 이해하기 위한 연구의 일환으로, 마늘성분 중의 하나인 allicin이 인체 대장암 세포주 HCT116의 증식에 미치는 영향을 확인하였다. allicin의 처리에 따라 세포사멸이 나타나며 생존율이 감소함을 확인하였다. 또한 oligo DNA microarray 실험을 통하여 allicin에 의해 발현되는 유전자 중 발현양의 차이를 보인 유전자중 2배 이상 up-regulation된 유전자는 7,840개, 2배 이상 down-regulation 된 유전자는 10,010개로 각각 분류 되었다. 이 중, ATF3유전자의 발현을 확인하였고, 또 다른 항암유전자인 NAG-1 유전자의 발현을 RT-PCR로 확인하였다. 그 결과, allicin처리에 의해 항암유전자인 ATF3의 발현과 NAG1 유전자의 발현이 증가함을 확인하였다. 또한 p53 HCT116 세포주를 이용하여 allicin에 의한 NAG1 단백질의 발현을 확인한 결과, allicin은 p53 유전자 의존적으로 NAG-1 단백질을 발현함을 확인하였다. 결론적으로 allicin은 세포주기나 세포사멸에 관련된 많은 유전자들의 발현 변화를 유도함으로써 암세포 성장억제 활성을 갖는 것으로 사료된다.

• 한국정밀공학회지
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• 제33권4호
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• pp.279-286
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• 2016

To enhance the safety of nuclear reactors after the Fukushima accident, researchers are developing various types of accident tolerant fuel (ATF) to increase the coping time and reduce the generation of hydrogen by oxidation. Coated cladding, an ATF concept, can be a promising technology in view of its commercialization. We applied 3D printing technology to the fabrication of coated cladding as well as of coated pellets. Direct metal tooling (DMT) in 3D printing technologies can create a coated layer on the tubular cladding surface, which maintains stability during corrosion, creep, and wear in the reactor. A 3D laser coating apparatus was built, and parameter studies were carried out. To coat pellets with erbium using this apparatus, we undertook preliminary experiments involving metal pellets. The adhesion test showed that the coated layer can be maintained at near fracture strength.