• Macromolecular Research
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• v.14 no.5
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• pp.559-564
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• 2006

The improvement of spatial resolution is a fundamental issue in the two-photon, polymerization-based, laser writing. In this study, a voxel tuning method using a radical quencher was proposed to increase the resolution, and the quenching effect according to the amount of radical quencher was experimentally investigated. Employing the proposed method, the lateral resolution of the line patterns was improved almost to 100 nm. However, a shortcoming of the quenching effect was the low mechanical strength of polymerized structures due to their short chain lengths. Nano-indentation tests were conducted to evaluate quantitatively the relationship between mechanical strength and the mixture ratio of the radical quencher into the resins. The elastic modulus was dramatically reduced from an average value of 3.015 to 2.078 GPa when 5 wt% of radical quencher was mixed into the resin. Three-dimensional woodpile structures were fabricated to compare the strength between the resin containing radical quencher and the original resin.

• Journal of Applied Biological Chemistry
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• v.56 no.3
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• pp.137-139
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• 2013

Free radical scavengers in the bisdemethoxycurcumin (BDMC), demethoxycurcumin (DMC) and curcumin of turmeric (Curcuma longa) were screened, identified, quantified and isolation using coupled off-line-2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and on-line screening high-performance liquid chromatography (HPLC)-ABTS assay. There was a very small margin of error between the off-line-ABTS method and the on-line screening HPLC-ABTS method.

• Journal of the Korean Magnetic Resonance Society
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• v.4 no.2
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• pp.91-102
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• 2000

The photoproduced cation radical of N-methylphenothiazine doped in the different kind of matrices of phenyltriethoxysilane (PhiTEOS), vinyltriethoxysilane (VTEOS), and methyloiethoxysilane (METOS) was comparatively studied with electron spin resonance (ESR) and electron nuclear double resonance (ENDOR). The photoinduced charge separation efficiency was determined by integration of ESR spectra which correspond to the amount of photoproduced cation radical in the matrices. This was correlatively studied with the polarity and pore size of the gel matrices. The polarity of the matrices was comparatively determined by measuring λ$\sub$max/ values of PC$_1$ in the different matrices. The relative pore size among the matrices was determined by measuring relative proton matrix ENDOR line widths of the photoproduced cation radical of PCI. The decay kinetic constants of the cation radical of PCI in the different matrices was relatively studied with fitting the biexponential decay curves after exposure into the ambient condition. This is correlatively interpreted with the polarity and pore size of the matrices.

• Journal of the Korean Magnetic Resonance Society
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• v.6 no.2
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• pp.103-112
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• 2002

The photoproduced cation radical of N-methylphenothiazine $(PC_1)$ doped into phenyltriehtoxysilane (PhiTEOS), vinyltriethoxysilane (VTEOS) and methyltriethoxysilane (METOS) was studied with electron spin resonance (ESR) and electron nuclear double resonance (ENDOR). The photoinduced charge separation efficiency was determined by integration of ESR spectra which correspond to the amount of photoproduced cation radical in the matrices. This was correlatively studied with the polarity and pore size of the gel matrices. The relative polarity of the matrices was determined by measuring ${\lambda}_{max}$ values of $PC_1$ in the different matrices. The relative pore size among the matrices was determined by measuring relative proton matrix ENDOR line widths of the photoproduced cation of $PC_1$. The decay kinetic constants of the cation radical of $PC_1$ in the different matrices with relatively studied with fitting the biexponential decay curves after exposure at the ambient condition. This is correlatively interpreted with the polarity and pore size of the matrices.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.2
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• pp.710-719
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• 1996

Laser applied combustion diagnostic techniques-laser induced fluorescence (LIF) and coherent anti-Stokes Ramann spectroscopy (CARS)-are demonstrated. The profiles of hydroxyl radical (OH) and temperature in the counterflow burner are measured and compared with the numerical results. OH radical is excited on the Q$_1$(6) line of the $A^2$$\sum^+$$\leftarrow$$X^2{\prod}$(1, 0) band transition (281.1 nm) and LIF signal is measured at the the bands of (0, 0) and (1, 1) transition (306~326 nm). Absolute OH radical is obtained by using the laser absorption technique. The quenching effects are considered. Temperature is measured using broadband CARS system. Two dimensional OH radical profile is also obtained. The profiles of OH radical and temperature are found to agree well with those of numerical calculation.

• The Korean Journal of Food And Nutrition
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• v.37 no.2
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• pp.80-87
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• 2024

This study examined the quality characteristics of 10 different lines of native peppers collected from organic farms in Chungbuk province. The study found a strong correlation between the redness (a*) and ASTA values, which both contribute to the perceived quality of peppers. The highest values were observed in the Iyugsa line. The content of capsaicinoid and beta-carotene also showed a positive correlation, with Chilsungcho having the highest statistically significant value. While the total polyphenol content did not correlate with the other indicators, Chilsungcho again had the highest levels. The Yuwolcho line exhibited the highest ABTS radical scavenging ability, while the Eumseongcho line showed the highest DPPH radical scavenging ability. Taking into account the overall bioactivity quality, Chilsungcho had the highest values in terms of total polyphenol, beta-carotene, capsaicinoid, and redness. It also had the second highest total flavonoid content, ABTS, and DPPH radical scavenging activity, all statistically significant. Therefore, Chilsungcho can be considered an excellent choice when considering physiological activity. Furthermore, this study provides valuable information about the unique characteristics of these 10 native pepper lines, which can assist in selecting the appropriate pepper for food manufacturing and serve as a helpful resource for future research.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1135-1139
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• 2017

Spatial distribution of chemical species in flame is a important indicator understanding the flame structure and combustion characteristics, and optical emission spectroscopy has been widely used for the measurement because of its simple and non-intrusive methodology. In this study, we suggest the feasibility of the measurement of chemical species (OH radical) distribution in rocket plume using optical emission spectrometer which was developed for the spatially resolved measurement along the line-of-sight. In order to predict the ground state concentration of species from the measured emission intensity by optical emission spectrometer, we consider thermal and chemical excitation mechanisms in flame, and assume thermodynamic equilibrium for the thermally excited species. We also present the spatial resolution and the correction of collection characteristics of the optical emission spectrometer depending on object distance.

• Journal of Pharmacopuncture
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• v.14 no.3
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• pp.55-61
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• 2011

Objectives: Reactive Oxygen Species(ROS) are continuously produced at a high rate as a by-product of aerobic metabolism. Since tissue damage by free radical, ROS such as hydrogen peroxide($H_2O_2$), nitric oxide(NO) increases with age. Several lines of evidence provided that ROS appears to cause to develop aging-related various diseases such as cancer, arthritis, cardiovascular disease. In this study, we have conducted to investigate the pharmacological effects of red ginseng for the development possibility to pharmacopuncture drug sources or healthy aid foods. Methods: For our aims, it was investigated the biological activities of Red Ginseng ethanol extracts (RGEE) by measuring total polyphenol contents, total flavonoid contents, DPPH radical scavenging activity, ABTS radical scavenging activity and cell viability of MCF 10A and SK-MEL-2 in vitro with MTT assay method. Results: The total polyphenol contents of RGEE was 3.06${\pm}$0.11mg/g in 10mg/ml, the total flavonoid contents of RGEE was 1.35${\pm}$0.01mg/g in same concentration. The ABTS radical scavenging activity was about 80% and that of DPPH activity was 65% in 50mg/ml of RGEE. The cell viability of SKMEL-2, skin cancer cell line was decreased and that of MCF 10A, skin normal cell line was increased. Conclusions: We conclude that RGEE may be useful as potential functional foods or pharmacopuncture drug sources on the diseases induced by oxidant stress.

• The Journal of Korean Obstetrics and Gynecology
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• v.21 no.4
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• pp.69-89
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• 2008

Purpose: This study was performed to evaluate anti-oxidant activities and anti-inflammatory effects of Sungyoutanggagambang(SYTG). Methods: In the study of anti-oxidant activities. SYTG was investigated by DPPH radical scavenger activity. superoxide dismutase activity and superoxide anion radical scavenger activity. In the study of anti-inflammatory effects. SYTG was investigated using cultured cells and murine models. As for the parameters of inflammation. levels of several inflammatory cytokines and chemical mediators which are known to be related to inflammation were measured in mouse lung fibroblast cells(mLFCs) and RAW264.7 cells. Results: Prior to the experiment. we investigated the security of SYTG by measuring GOT and GPT in serum. 1. SYTG showed high antioxidant activity in a concentration-dependent degree by measured scavenging activity of DPPH free radical, superoxide dismutase and superoxide anion radical. 2. SYTG inhibited IL-1$\beta$, IL-6. TNF-$\alpha$, COX-2 and NOS-II mRNA expression as compared with the control group in a concentration-dependent degree in RAW264.7 cell line. 3. SYTG inhibited IL-1$\beta$, IL-6 production significantly at 100 ${\mu}g/ml$ and TNF-$\alpha$ production significantly at 50, 100 ${\mu}g/ml$ as compared with the control group in RA W264.7 cell line. 4. SYTG inhibited IL-1$\beta$, and IL-6 production significantly as compared with the control group in serum of acute inflammation-induced mice. and decreased IL-1$\beta$, IL-6 production in spleen tissue. and also decreased IL-1$\beta$, IL-6 production in liver tissue. Conclusion: These results suggest that SYTG can be useful in treating diverse female diseases caused by inflammation such as endometrosis, myoma, pelvic congestion. chronic cervicitis, chronic pelvic inflammatory disease and so on.

• Korean Journal of Pharmacognosy
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• v.34 no.4 s.135
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• pp.324-326
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• 2003

The methanol (MeOH) extract and ist fractions of Taraxacum mongolicum (Compositae) were examined for their scavenging effects on 1,1-diphenyl-2- phenylhydrazyl (DPPH) and superoxide radicals, and hepatoprotective effects on tacrine-induced cytotoxicity in human hepatoma cell line, Hep G2 cells. Both methylene chloride $(CH_2Cl_2)$ and butanol (n-BuOH) soluble fractions of the MeOH extract showed the free radicals scavenging and hepatoprotective effects. From these results, it is suggested that hepatoprotective effect of these fractions partly relies on their free radical scavenging activity.