• 분석과학
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• 제30권4호
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• pp.159-166
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• 2017

Exposure to UV light, i.e., UV-A (320-400 nm) or UV-B (290-320 nm) radiation, can cause skin cancer. Titanium dioxide ($TiO_2$) effectively disperses UV light. Therefore, it is used as a physical UV filter in many UV light blockers. Usually, the $TiO_2$ content in commercialized UV blockers is 25 % at most. To block UV-B, a chemical UV blocker, octyl-methoxy cinnamate (OMC) is used. OMC is commonly used in combination with $TiO_2$. In this study, $TiO_2$ and OMC were mixed in different proportions to produce UV blockers with different compositions. Also the changes in the sun protection factor (SPF) based on the composition and $TiO_2$ particle sizes were investigated. In order to analyze the $TiO_2$ particle size, dynamic light scattering (DLS) and asymmetrical flow field-flow fractionation (AsFlFFF) were used. The results showed that the SPF was influenced by the proportion of $TiO_2$ and OMC, where the proportion of $TiO_2$ induced a more significant influence. In addition, changes in the $TiO_2$ particle size based on the proportion of OMC were observed.

• 한국해양바이오학회지
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• 제2권2호
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• pp.86-93
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• 2007

만성염증은 치주염, 대장염, 간염 및 관절염과 밀접한 관련성이 있다고 알려져 있다. 최근에 항염증제가 해양자원으로부터 개발되고 있다. 본 연구에서는 감태 (EC)가 항염증효과가 있다는 것이 발견되었다. 갈조류에 속하는 감태의 에탄올 추출물이 RAW 264.7 세포에서 tumor necrosis factor-${\alpha}$ interleukin-$1{\beta}$, interleukin-6 and prostaglandin $E_2$와 같은 염증매개체의 생성에 탁월한 효과를 나타내었다. 더욱이 reporter gene assay 및 western blot 분석 에 서 감태추출물은 대식세포에서 염증매개체의 발현을 조절하는 NF-${\kappa}B$ 전사인자의 불활성화를 통하여 항염증효과를 나타내었다. 뿐만 아니라 감태추출물은 만성염증에 중요한 역할을 하는 기질금속단백질의 활성을 억제 하였다. 이러한 결과는 갑태추출물이 만성염증을 억제하는데 잠재적으로 이용될 수 있다는 것을 암시하고 있다.

• Journal of Applied Biological Chemistry
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• 제64권3호
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• pp.263-268
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• 2021

7-Hydroxy-4-methylcoumarin (7H-4MC) inhibits hyaluronan production in multiple cell lines and tissue types both in vitro and in vivo. It is a commercially available drug approved for human use, called hymecromone, in European and Asian countries to prevent biliary spasms. Nevertheless, as the pharmacological efficacy of 7H-4MC has not yet been reported in macrophages, this study investigated its anti-inflammatory effects and mechanism of action using lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. LPS-induced RAW 264.7 cells were treated with various concentrations of 7H-4MC (62.5, 125, 250, and 500 μM). The application of 7H-4MC significantly reduced nitric oxide and prostaglandin E₂ production without cytotoxic effects. Additionally, 7H-4MC strongly decreased the expression of inducible nitric oxide synthase and cyclooxygenase. Furthermore, 7H-4MC reduced the production of proinflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. Finally, 7H-4MC exerted its potent anti-inflammatory actions via the upregulation of IκB-α production, which led to the inhibition of nuclear factor-κB (NF-κB) activity. These results, obtained in macrophage cell lines, suggest that 7H-4MC prevents inflammatory diseases via the NF-κB signaling pathway and that its use could be beneficial for human health. Ultimately, this is the first report describing the anti-inflammatory activity of 7H-4MC in a macrophage cell line.

• 한국자기공명학회:학술대회논문집
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• 한국자기공명학회 2002년도 International Symposium on Magnetic Resonance
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• pp.29-29
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• 2002

• Corrosion Science and Technology
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• 제16권3호
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• pp.151-159
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• 2017

The MA8 alloy (formula Mg-Mn-Се) has been shown to have greater corrosion stability than the VMD10 magnesium alloy (formula Mg-Zn-Zr-Y) in chloride-containing solutions by Scanning Vibrating Electrode Technique (SVET) and by optical microscopy, gravimetry, and volumetry. It has been established that the crucial factor for the corrosion activity of these samples is the occurrence of microgalvanic coupling at the sample surface. The peculiarities of the kinetics and mechanism of the corrosion in the local heterogeneous regions of the magnesium alloy surface were investigated by localized electrochemical techniques. The stages of the corrosion process in artificial defects in the coating obtained by plasma electrolytic oxidation (PEO) at the surface of the MA8 magnesium alloy were also studied. The analysis of the experimental data enabled us to determine that the corrosion process in the defect zone develops predominantly at the magnesium/coating interface. Based on the measurements of the corrosion rate of the samples with PEO and composite polymer-containing coatings, the best anticorrosion properties were displayed by the composite polymer-containing coatings.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.132-135
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• 2003

Solution chemistry, sorbate chemistry, and sorbent chemistry were widely investigated to find important factors that affect PAH sorption on mineral surfaces and to elucidate its microscopic mechanism. The solution chemistry, pH and ionic strength caused measurable change of HOC sorption reaction to minerals. The detectable change of Ka occurred at a pH region crossing the PZC (Point of Zero Charge) of each mineral. The PAH hydrophobicity, one of sorbate chemistry, was observed to have a strong correlation with PAM sorption to mineral. Mineral surface area was not found to be a predominant factor controlling PAH sorption. The mineral type might be more likely to play a crucial role in controlling the PAH sorption behavior. The CEC (Cation Exchange Capacity) of mineral, representing surface charge density, has meaningful correlation with regression slope of sorption coefficients (log $K_{d}$) versus aqueous activity coefficients (log Υ$_{w}$).).).

• Bulletin of the Korean Chemical Society
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• 제35권1호
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• pp.83-86
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• 2014

Poly(A) polymerase (PAP) play an essential role for maturation of mRNA by adding the adenylate residues at the 3' end. PAP functions are regulated through protein-protein interaction at its C-terminal region. In this study, cyclophilin A (CypA), a member of the peptidyl-prolyl cis-trans isomerase family, was identified as a partner protein interacting with the C-terminal region PAP. The interaction between PAP and CypA was inhibited by the immunosuppressive drug cyclosporine A. Deletion analysis revealed that the N-terminal 56 residues of CypA are sufficient for the interaction with PAP. Interestingly, we observed that PAP and CypA colocalize in the nucleus during SDF-1-induced chemotaxis, implying that CypA could be involved in the regulation of polyadenylation by PAP in the chemotactic cells.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.186.3-186.3
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• 2003

The three-dimensional quantitative structure-activity relationship (3D-QSAR) study using the comparative molecular field analysis (CoMFA) was performed on indolinones derivatives as an inhibitor of the protein tyrosine kinase of fibroblast growth factor receptor (FGFR). In the training set, twenty-four indolinone derivatives were aligned based on the indole fragment and the steric and electrostatic fields were included in the analysis. The best predicted model showed the cross-validated coefficient (r$^2$$\sub$cv/) of 0.804 and bib-cross validated coefficient (r$^2$) of 0.942. The CoMFA study can be used to predict several new inhibitors of the FGFR.

• Journal of Ginseng Research
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• 제44권4호
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• pp.593-602
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• 2020

Background: Heat stress orchestrates neurodegenerative disorders and results in the formation of reactive oxygen species that leads to cell death. Although the immunomodulatory effects of ginseng are well studied, the mechanism by which ginseng alleviates heat stress in the brain remains elusive. Methods: Rats were exposed to intermittent heat stress for 6 months, and brain samples were examined to elucidate survival and antiinflammatory effect after Korean Red Ginseng (KRG) treatment. Results: Intermittent long-term heat stress (ILTHS) upregulated the expression of cyclooxygenase 2 and inducible nitric oxide synthase, increasing infiltration of inflammatory cells (hematoxylin and eosin staining) and the level of proinflammatory cytokines [tumor necrosis factor α, interferon gamma (IFN-γ), interleukin (IL)-1β, IL-6], leading to cell death (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay) and elevated markers of oxidative stress damage (myeloperoxidase and malondialdehyde), resulting in the downregulation of antiapoptotic markers (Bcl-2 and Bcl-x_L) and expression of estrogen receptor beta and brain-derived neurotrophic factor, key factors in regulating neuronal cell survival. In contrast, KRG mitigated ILTHS-induced release of proinflammatory mediators, upregulated the mRNA level of the antiinflammatory cytokine IL-10, and increased myeloperoxidase and malondialdehyde levels. In addition, KRG significantly decreased the expression of the proapoptotic marker (Bax), did not affect caspase-3 expression, but increased the expression of antiapoptotic markers (Bcl-2 and Bcl-x_L). Furthermore, KRG significantly activated the expression of both estrogen receptor beta and brain-derived neurotrophic factor. Conclusion: ILTHS induced oxidative stress responses and inflammatory molecules, which can lead to impaired neurogenesis and ultimately neuronal death, whereas, KRG, being the antioxidant, inhibited neuronal damage and increased cell viability.

• 대한화학회지
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• 제36권5호
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• pp.720-726
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• 1992

겹쳐 나타나는 X-선 형광 스펙트라에서 얻은 다변수 데이타를 해석하기 위하여 다변수분석법인 인자분석법을 적용하였다. Pb와 As의 피크가 겹쳐 있는 11개 표준시료의 X-선 형광 스펙트라를 파장분산형기기로 $33.50∼34.50^{\circ}$에서 측정하였다. 8개 시료의 피크세기로 데이타 매트릭스를 구성하고 AFA(Abstract Factor Analysis)를 수행하였다. 그 결과 인자의 수가 3으로 나타났으며 표준시료에 함유된 8개 원소를 타겟트 테스트한 결과 Pb, As 및 Cu로 판명되었다. 농도 기지인 시험시료에서 상기 원소들의 농도를 피크의 겹침에 무관하게 TTFA(Target Transformation Factor Analysis)에 의해 결정하였다.