• Biomolecules & Therapeutics
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• 제32권2호
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• pp.214-223
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• 2024

Metabolic abnormalities in the liver are closely associated with diverse metabolic diseases such as non-alcoholic fatty liver disease, type 2 diabetes, and obesity. The aim of this study was to evaluate the ameliorating effect of robinetin (RBN) on the significant pathogenic features of metabolic failure in the liver and to identify the underlying molecular mechanism. RBN significantly decreased triglyceride (TG) accumulation by downregulating lipogenesis-related transcription factors in AML-12 murine hepatocyte cell line. In addition, mice fed with Western diet (WD) containing 0.025% or 0.05% RBN showed reduced liver mass and lipid droplet size, as well as improved plasma insulin levels and homeostatic model assessment of insulin resistance (HOMA-IR) values. CD38 was identified as a target of RBN using the BioAssay database, and its expression was increased in OPA-treated AML-12 cells and liver tissues of WD-fed mice. Furthermore, RBN elicited these effects through its anti-histone acetyltransferase (HAT) activity. Computational simulation revealed that RBN can dock into the HAT domain pocket of p300, a histone acetyltransferase, which leads to the abrogation of its catalytic activity. Additionally, knock-down of p300 using siRNA reduced CD38 expression. The chromatin immunoprecipitation (ChIP) assay showed that p300 occupancy on the promoter region of CD38 was significantly decreased, and H3K9 acetylation levels were diminished in lipid-accumulated AML-12 cells treated with RBN. RBN improves the pathogenic features of metabolic failure by suppressing the p300-CD38 axis through its anti-HAT activity, which suggests that RBN can be used as a new phytoceutical candidate for preventing or improving this condition.

• Asian Pacific Journal of Cancer Prevention
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• 제13권6호
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• pp.2629-2633
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• 2012

Background: Raw betel nut (RBN) chewing is an important contributing factor for esophageal squamous cell carcinoma (ESCC), although associated genomic changes remain unclear. One difficulty in assessing the effects of exclusively RBN induced genetic alterations has been that earlier studies were performed with samples of patients commonly using tobacco and alcohol, in addition to betel-quid. Both CDKN2A (at 9p21) and Rb1 gene (at 13q14.2) are regarded as tumor suppressors involved in the development of ESCC. Therefore, the present study aimed to verify the RBN's ability to induce ESCC and assess the involvement of CDKN2A and Rb1 genes. Methods: A panel of dinucelotide polymorphic markers were chosen for loss of heterozygosity studies in 93 samples of which 34 were collected from patients with only RBN-chewing habit. Promoter hypermethylation was also investigated. Results: Loss in microsatellite markers D9S1748 and D9S1749, located close to exon $1{\beta}$ of CDKN2A/ARF gene at 9p21, was noted in 40% ESCC samples with the habit of RBN-chewing alone. Involvement of a novel site in the 9p23 region was also observed. Promoter hypermethylation of CDKN2A gene in the samples with the habit of only RBN-chewing alone was significantly higher (p=0.01) than Rb1 gene, also from the samples having the habit of use both RBN and tobacco (p=0.047). Conclusions: The data indicate that the disruption of 9p21 where CDKN2A gene resides, is the most frequent critical genetic event in RBN-associated carcinogenesis. The involvement of 9p23 as well as 13q14.2 could be required in later stages in RBN-mediated carcinogenesis.

• 한국항해학회지
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• 제24권3호
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• pp.157-165
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• 2000

When the GPS system was come to the operation, the U.S Coast Guard initiated development of differential GPS system based on a marine radiobeacon. It has rapidly been spread out to many countries. DGPS equals to P(Y) code in a positioning accuracy. USA has recently determined to expand the coverage of DGPS to inland in order to install a nationwide DGPS chain. Korea is under processing for improving the DGPS as a nationwide positioning system. Before expanding the service area inside Korea, we need to verify the relation between the field strength and DGPS accuracy for the service area. The Japanese DGPS data is received in the southern Part of the Korean peninsula. The Korean DGPS was not a complete system, so we selected the Japanese DGPS data as a model for the study. This paper investigate accuracy and reliability characteristics of RBN/DGPS over the effective service area. Through the experimental and simulation study, we obtained the reliable and stable positioning accuracy in the southern part of the Korean peninsula. In addition, the characteristics of RBN/DGPS were examined in the land over the effective coverage from Japan. The results would be a basic reference to research the RBN/NDGPS in Korea.

• 한국신뢰성학회지:신뢰성응용연구
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• 제6권2호
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• pp.187-194
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• 2006

In this paper, We presented the algorithm for estimating a reliability between nodes in wireless communication network such as RBN and MANET To estimate the reliability between nodes, we first modeled RNB and MANET as probability graph. Branches of the graph are always reliable and the probability of node failure is independent. After all possible simple path which can be established between two nodes are examined, we perform sharp arithmetic to remove repetition event between two nodes. Using probability for each variable of the minimized Boolean equation, we present the reliability formula.

• 한국정보과학회논문지:정보통신
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• 제36권5호
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• pp.369-375
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• 2009

주택내 광대역통신망(Residential Broadband Network: RBN)은 xDSL/Cable 망에서 점차 100Mbps급의 FTTH로 발전하고 있다. 사용자들은 고속의 인터넷서비스를 이용하여 웹, 멀티미디어, 게임, 및 파일 공유 등 다양한 인터넷 응용들을 사용하고 있다. 따라서, 주택내 초고속 인터넷 망의 성능은 사용자의 만족도에 중요한 영향을 끼치게 된다. 일반적으로 ISP들은 특정 서버와 소프트웨어를 통해 사용자의 접속을 유도하여 망 성능 측정 결과를 공개하고 있다. 이러한 방법은 사용자의 적극적인 참여를 통한 측정이기 때문에 많은 시간과 비용이 들게 되며, 사용자의 참여를 적극적으로 유도해야한다. 본 논문은 최소한의 테스트 트래픽을 특정 서버에서 생성하여 주택내 광대역통신망의 성능 측정 방법인 Monarch라는 툴을 활용하여 국내의 대표적인 3개 ISP의 FTTH 인터넷 성능을 측정하고 분석한 결과를 제시하였다. 300개 이상의 유효 국내 FTTH 가입자들에 대한 광범위한 실험을 통하여 사용자가 직접 측정한 결과와 비교할 때 큰 오차를 보이지 않음을 확인하였고, 국내 ISP의 FTTH 망 $80{\sim}90Mbps$의 대역폭과 30ms 이내의 RTT를 관찰할 수 있었다.

• 한국물환경학회지
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• 제37권1호
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• pp.10-19
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• 2021

In the flotation process to remove microplastic (MP) particles, the attachment and separation efficiency is determined by the basic physicochemical characteristics of MP particles as well as bubbles. To evaluate the flotation characteristics of MP particles, we carried out a series of simulations using the population balance (PB) model. The initial attachment coefficient (αo) of MP particles was in the range of 0.2-0.275, and it was slightly lower than that of typical particles, such as clay, debris and algae particles, which exist in water bodies, αo, 0.3-0.4. The relative bubble number (RBN) attached to the surface of the typical number of bubbles was 0.30 and 0.32 for MP 30 ㎛ and MP 58 ㎛, respectively. In comparison, the RBN of larger MP particles (138 ㎛) was as high as 0.53. Furthermore, smaller microbubbles were required to separate properly or additional treatment needed to be applied to enhance collision and attachment efficiency since the flotation of MP particles was found to be difficult to treat as high-rate. As a result of comparing the removal rate (experimental value) of MP particles obtained from the batch-type flotation apparatus and the flotation removal rate (predicted value) of MP obtained through the PB model, the final particles by the particle size of MP overall except for the initial separation time area. With respect to the removal efficiency, the observed and predicted values were similar, and it was confirmed that the floating separation characteristics and evaluation of the MP particles through the PB model could be possible.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 춘계종합학술대회
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• pp.732-736
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• 2001

DGPS는 미 군사용 신호를 이용한 정밀도 수준을 제공할 수 있는 위성항법 시스템으로써 30여개 국가에서 해양용 국가망 위주로 구축되고 있다. 특히 미국은 해양용 DGPS 국가망을 내륙으로 확장한 NDGPS(Nationwide DGPS)체계 구축을 2002년까지 완성할 예정이다. 우리나라도 해양용 국가망을 운영하여 해양활동을 하는 사용자에게 3차원 고정밀 위치정보를 제공하고 있다. 근래에 우리나라 연안에 구축되어 사용중인 해양용 라디오비이콘형 DGPS망을 육상으로 연계한 서비스범위 확대방안이 논의되고 있다. 본 연구는 NDGPS에 대한 기초연구로서 운용중인 DGPS 기준국신호를 모델로 하여 해상 전파 설계치 대비 거리 및 지형변화에 따른 전계강도 변화를 분석하였다.