• 대한기계학회논문집A
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• 제34권4호
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• pp.467-474
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• 2010

용접이음부의 신뢰성 확보는 구조물의 건전성과 내구성에 직접적인 영향을 미치기 때문에 가스용접 이음재의 피로설계기준(fatigue design criterion)을 정하기 위해서는 피로시험을 수행하여 ${\Delta}P$-Nf 관계를 이용하는 것이 일반적이다. 그러나 피로데이터를 장시간 획득하는 과정에서 여러 가지 변동인자에 의해서 피로데이터가 영향을 받기 때문에 피로데이터의 신뢰도가 떨어진다. 또한, 이음재의 재질 및 접합형태가 달라질 때마다, 각각의 경우에 대해서 새로운 피로시험이 요구됨으로 많은 시간과 비용이 소모된다. 따라서 이러한 문제점들을 개선하고 신뢰성 있는 설계를 하기 위해서 필렛 가스용접 이음재를 적용, 반복피로시험을 통한 데이터를 통계적으로 분석하여, 다양한 가스용접 이음재의 피로수명을 예측함과 동시에 실제 피로시험데이터와 비교 분석하여 예측된 수명의 신뢰도(reliability)와 신뢰구간(confidence interval)을 추정함으로서 새로운 피로설계기준 방법을 제시하고자 하였다.

• 멤브레인
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• 제28권4호
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• pp.286-295
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• 2018

폴리에틸렌이민(분자량 800)에 다가이온을 갖는 정삼투용 새로운 유도용질을 합성하고 특성을 분석하였다. 폴리에틸렌이민과 메틸 아크릴레이트의 중화반응으로 중간체를 합성하고, KOH로 가수분해하여 수용성의 카복실산 금속염 형태의 폴리에틸렌이민을 합성하였다. NMR, 점도, 삼투압을 측정하여 유도용질의 특성을 평가하였다. 그 염이 유도용질로서 사용할 수 있는지의 여부를 정삼투 실험을 통하여 알아보았다. 유도용질로서 수투과도와 역염 투과도를 측정하여 NaCl과 비교하였다. 정삼투와 나노여과의 혼성공정을 통하여 유도용질의 회수가능성을 보였다.

• 한국식품조리과학회지
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• 제14권4호
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• pp.375-379
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• 1998

Some Physico-chemical properties of korean red pepper seed oil were evaluated to find available method to utilize red pepper seeds used as useful cooking oil resources. Samples of red pepper seeds used as oil meterials were native, improved species and they were named such as NS (native spicies dried under sunlight), IS (improved spicies dried under sunlight), NF (native spicies dried by heating), and IF(improved spicies dried by heating), respectively. Moisture, ash, crude protein and crude fat contents of all red pepper seeds were 6.6%∼7.7%, 3.3∼3.5%, 18.25∼19.4% and 26.8∼27.5% in all samples, showing the specially high crude fat and crude protein content in NS. Capsaicin contents in crude red pepper seed oils were shown from 0.06 to 0.08% but after refining process, capsaicin contents were mostly tossed as 0∼0.006%. The types of tocopherol found in crude and refined red pepper seed oils were ${\gamma}$-, ${\alpha}$-, $\delta$-analogues, the amount of total tocopherol in IF was 2.10 mg/g oil which were the highest value of all red pepper seeds. In all red pepper seeds oils main fatty acids were linoleic acid (68∼70%), palmitic acid (14∼16%), oleic acid (10∼11%), and linolenic acid were extemely small amounts. The specific gravity (SG) 0.916∼0.919, refractive index (RI) 1.4724, acid value (AV) 0.26∼0.36, peroxide value (POV) 0.73∼1.19 and Iodine value (IV) 134.35∼134.92 were measured in all red pepper seed oils.

• Preventive Nutrition and Food Science
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• 제8권4호
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• pp.390-394
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• 2003

In the post-genome period, the technique for identifying gene expression has been progressed to high throughput screening. In the field of molecular nutrition, the use of screening techniques to clarify molecular function of specific nutrients would be very advantageous. In this study, we have evaluated Zn-regulated gene expression in Zn-deficient, homocystein-treated EA.hy926 cells, using cDNA microarray, which can be used to screen the expression of many genes simultaneously. The information obtained can be used for preliminary assessment of molecular and signaling events modulated by Zn under pro-atherogenic conditions. EA.hy926 cells derived from human umbilical vein endothelial cells were cultured in Zn-adequate (control, 15 $\mu$M Zn) or Zn-deficient (experimental, 0 $\mu$M Zn) Dulbecco's MEM media under high homocysteine level (100 $\mu$M) for 3 days of post-confluency. Cells were harvested and RNA was extracted. Total RNA was reverse-transcribed and the synthesized cDNA was labeled with Cy3 or Cy5. Fluorescent labeled cDNA probe was applied to microarray slides for hybridization, and the slide was then scanned using a fluorescence scanner. The expression of seven genes was found to be significantly decreased, and one significantly increased, in response to treatment of EA.hy926 cells with Zn-deficient medium, compared with Zn-supplemented medium. The upregulated genes were oncogenes and tumor suppressor genes, cell cycle-related genes and transporter genes. The down-regulated gene was RelB, a component of the NF-kappaB complex of transcription factors. The results of this study imply the effectiveness of cDNA microarray for expression profiling of a singly nutrient deficiency, namely Zn. Furthur study, using tailored-cDNA array and vascular endothelial cell lines, would be beneficial to clarify the molecular function of Zn in atherosclerosis, more in detail.

• 한국지능시스템학회논문지
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• 제15권4호
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• pp.425-430
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• 2005

많은 문제가 그래프로 모델링될 수 있고, 그래프 이론에 기반한 방법에 의해서 해결될 수 있다. 이 논문에서는 분산되고 중첩된 대사경로 네트워크들에 대해서 경로를 찾는 방법에 대해서 다룬다. 제안한 방법은 분산된 그래프를 통합하지 않은 채, 다중 에이전트의 협동작업을 통해서 경로를 찾는 방법이다. 각 그래프에는 해당 그래프를 책임지고 있는 에이전트가 하나씩 있어서, 해당 그래프에서 시작되는 경로검색을 주도하고, 다른 에이전트로부터 경로에 대한 정보 요청에 응답하도록 한다. 제안한 방법에서는 우선 전체 분산된 그래프에 대해서 뷰그래프라고 하는 추상화된 그래프를 형성하고, 이를 이용하여 경로를 찾기 위해 에이전트간에 어떤 방법으로 협력을 할지 알 수 있게 한다. 각 에이전트는 해당 그래프에 대한 최단경로 정보를 관리하고 있다. 어떤 에이전트가 해당 그래프의 어떤 노드에서 시작하는 경로를 찾으라는 요구를 받게 되면, 다른 에이전트로부터 정보를 받아서 목적지까지는 가는 경로를 찾게 된다.

• Journal of Ginseng Research
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• 제41권4호
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• pp.513-523
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• 2017

Background: Korean Red Ginseng extracts (RGE) have been suggested as effective immune modulators, and we reported that ginsenosides possess anti-inflammasome properties. However, the properties of nonsaponin components of RGE have not been well studied. Methods: To assess the roles of nonsaponin fractions (NS) in NLRP3 inflammasome activation, we treated murine macrophages with or without first or second inflammasome activation signals with RGE, NS, or saponin fractions (SF). The first signal was nuclear factor kappa-light-chain-enhancer of activated B cells (NF-${\kappa}B$)-mediated transcription of pro-interleukin (IL)-$1{\beta}$ and NLRP3 while the second signal triggered assembly of inflammasome components, leading to IL-$1{\beta}$ maturation. In addition, we examined the role of NS in IL-6 production and IL-$1{\beta}$ maturation in mice. Results: NS induced IL-$1{\beta}$ and NLRP3 transcription via toll-like receptor 4 signaling, whereas SF blocked expression. During the second signal, SF attenuated NLRP3 inflammasome activation while NS did not. Further, NS-injected mice presented increased IL-$1{\beta}$ maturation and IL-6 production. Conclusion: SF and NS of RGE play differential roles in the NLRP3 inflammasome activation. Hence, RGE can be suggested as an NLRP3 inflammasome modulator.

• 한국전자파학회논문지
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• 제27권2호
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• pp.220-223
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• 2016

본 논문에서는 캐스코드(cascode) 구조에 트랜지스터를 추가하여 잡음 특성을 유지하면서 높은 선형성을 갖는 저잡음 증폭기 구조를 제안하고 설계하였다. 제안한 구조는 트랜지스터의 사이즈 최적화를 통해 잡음원을 최소화 했으며, 전류원분리(current bleeding) 효과를 주어 선형성을 개선하였다. 저잡음 특성에 유리한 $0.5{\mu}m$ pHEMT 공정을 이용해 제작된 저잡음 증폭기는 1.8~2.6 GHz의 동작 대역에서 30.8 dBm의 $OIP_3$, 15.0 dB의 이득, 1.1 dB의 NF, 11.6 dB/10.4 dB의 입출력 반사 손실 특성을 보였다.

• KSBB Journal
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• 제30권4호
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• pp.182-190
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• 2015

The Zostera marina ethanolic extract (ZMEE) was tested in this study to investigate the anti-inflammatory activity in LPS-induced RAW 264.7 cells and mouse model. Nitric oxide production and inducible nitiric oxide synthase expression in cells treated with ZMEE was reduced significantly in a dose-dependent manner. Similarly, the secretion of pro-inflammatory cytokines such as interleukin (IL)-6, IL-$1{\beta}$, and TNF-${\alpha}$ was inhibited markedly. In addition, the expression of nuclear factor kappa B (NF-${\kappa}B$) and the phosphorylation of JNK, ERK, and p38 MAPKs was suppressed by ZMEE as well. In vivo test, ZMEE attenuated the croton oil-induced mouse ear edema and there were no mortalities in mice administered 5,000 mg/kg body weight of ZMEE during the observation periods. The results in photomicrograph of mice ear tissue showed the reduction of dermal thickness and the number of infiltrated mast cells. These results indicate that ZMEE inhibits the production of LPS-induced pro-inflammatory mediators, suggesting that ZMEE may be a potential material for anti-inflammatory therapies.

• BMB Reports
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• 제51권4호
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• pp.188-193
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• 2018

Caffeoylserotonin (CaS), one derivative of serotonin (5-HT), is a secondary metabolite produced in pepper fruits with strong antioxidant activities. In this study, we investigated the effect of CaS on proliferation and migration of human keratinocyte HaCaT cells compared to that of 5-HT. CaS enhanced keratinocyte proliferation even under serum deficient condition. This effect of CaS was mediated by serotonin 2B receptor (5-HT2BR) related to the cell proliferation effect of 5-HT. We also confirmed that both CaS and 5-HT induced G1 progression via 5-HT2BR/ERK pathway in HaCaT cells. However, Akt pathway was additionally involved in upregulated expression levels of cyclin D1 and cyclin E induced by CaS by activating 5-HT2BR. Moreover, CaS and 5-HT induced cell migration in HaCaT cells via 5-HT2BR. However, 5-HT regulated cell migration only through ERK/AP-1/MMP9 pathway while additional Akt/NF-${\kappa}B$/MMP9 pathway was involved in the cell migration effect of CaS. These results suggest that CaS can enhance keratinocyte proliferation and migration. It might have potential as a reagent beneficial for wound closing and cell regeneration.

• Journal of Ginseng Research
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• 제33권2호
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• pp.93-98
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• 2009

To understand the anti-allergic mechanism of compound K, which is a metabolite of ginsenoside Rb1, a main constituent of the root of Panax ginseng C.A. Meyer (family Araliaceae), its inhibitory effect against IgE-antigen complex IAC)-induced passive cutaneous anaphylaxis (PCA) reaction in mice and mRNA and protein expressions of allergic cytokines in lAC-stimulated RBL-2H3 cells were investigated. Orally administered ginsenoside Rb1 more potently inhibited PCA reaction when administered at 5 h prior to the lAC treatment than when administered at I h before. However, compound K orally administered 1 h before lAC treatment showed a more potent anti-PCA reaction effect than when treated at 5 h before. Orally administered ginsenoside Rb1 more potently inhibited PCA reaction induced by lAC in mice than intraperitoneally treated one, apart from orally administered its metabolite, compound K, which was more potent than the orally administered one. The compound K, a metabolite of ginsenoside Rb1, inhibited mRNA and protein expressions of IL-4 and TNF-${\alpha}$ and the activation of their transcription factor NF-$\kappa$B and MAPK in lAC-stimulated RBL-2H3 cells. These findings suggest that orally administered ginsenoside Rb1 may be dependent on its metabolism by intestinal microflora in the intestine and the compound K may improve allergic diseases by the inhibition of IL-4 and TNF-${\alpha}$ expresseion.