• The Korean Journal of Food And Nutrition
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• v.16 no.1
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• pp.60-65
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• 2003

An antioxidant compound was obtained from the water extract of the stem bark from Rhus verniciflua, which has been used in traditional folk remedies. The compound was purified by HPLC, using DEAE, CN and ODS columns. The chemical structure of the compound was identified as gallic acid (3,4,5-hydroxylbenzoic acid) by spectral data including UV, IR, EI (HR)-MS, $^1$H-NMR, $\^$13/C-NMR and elemental analyzer. This compound was found show cytotoxicity against HeLa cell ( IC$\_$50/ : 8.5$\mu\textrm{g}$/$m\ell$).

• International Journal of Aeronautical and Space Sciences
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• v.18 no.1
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• pp.154-164
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• 2017

This work conducts a validation study for the XH-59A helicopter using a rigid coaxial rotor system in order to establish the techniques of the conceptual design and performance analysis for the lift-offset compound rotorcraft. As a tool for conceptual design and performance analysis, NDARC (NASA Design and Analysis of Rotorcraft) is used for the present study. An assumed mission profile is considered for the conceptual design of the XH-59A. As a validation result of the design, the dimensions and weight of the XH-59A are appropriately designed when compared to the target values since the relative error is less than 0.5%. Then, performance analyses are conducted for the designed XH-59A model with and without auxiliary propulsion in hover and forward flight conditions. The present analyses show good validity since the prediction results compare well with both the flight test and previous analyses. Therefore, the techniques for the conceptual design and performance analysis of the lift-offset compound helicopter are overall considered to be appropriately established. In addition, this study investigates the influence of the lift-offset on the rotor effective lift-to-drag ratio of the XH-59A helicopter with auxiliary propulsion. As a result, the improvement of the rotor effective lift-to-drag ratio can be obtained by appropriately increasing the lift-offset in high-speed flight.

• Journal of Ocean Engineering and Technology
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• v.23 no.5
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• pp.54-60
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• 2009

Exposed to various environments, concrete confronts degradation by a lot of physical and chemical reaction. Though so many experiments and theorizations on the single condition of concrete degradation have been carried out by constant studies, the truth for now is that there are few studies on the compound phenomenon of degradation related with marine environments. Accordingly, this study measured the degree of degradation in the change of external shape, the change of unit weight and compressive strength, ultrasonic velocity test, and the change of length, etc. after exposing the specimen of cement mortar to the environment between 0 cycle and the maximum of 300 cycles under the condition of aquatic curing, freezing and thawing, and compound degradation, using mineral admixture effective for concrete degradation as a binder. The result indicated that the case of adding mineral admixture showed greater resistance than that of using OPC only, and specifically, the specimen with the additive of slag powder and three component system showed very excellent resistance to freezing and thawing, and compound degradation.

• Archives of Pharmacal Research
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• v.15 no.1
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• pp.52-57
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• 1992

The molecular structure of a natural compound was determined by single crystal X-ray diffraction analysis. The compound was isolated by methanol extraction and repeated chromatography from the stem of Paulownia tomentosa. Yellow prismatic crystals of the compound, which were recrystallized from tetrahydrofuran, are triclinic, with a = 7.310 (6), b = 10.753(6), c = 11.586(5) ${\AA}.\;\alpha= 93.30(6),\;\beta=105.62(10),\;\gamma=109.49(7)^\circ,\;D_x=1.514,\;D_m=1.51 g/cm^3$, space group P1 and Z = 2. The structure was solved by direct method, and refined by least-squares procedure to the final R-value of 0.032 for 1271 independent reflections $(F\le3\sigma{(F))}$. The compound is one of new furanquinone analogue. The molecule has a nearly planar conformation with an intramolecular hydrogen bond. In the crystal, the planar molecules are arranged as a prallel sheet-like pattern, and these stackings are stabilized by the O-H...O type intermolecular hydrogen bonds. The other intermolecular contacts appear to be the normal van der Waals interactions.

• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.591-599
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• 2015

Cercidiphyllum japonicum leaves were collected, air-dried and extracted with 70% aqueous acetone, then concentrated and sequentially fractionated using n-hexane, methylene chloride ($CH_2Cl_2$), ethylacetate (EtOAc), and $H_2O$. A portion of EtOAc fraction (10 g) was chromatographed on a Sephadex LH-20 column, by the successively elution with various aqueous $MeOH-H_2O$ (1:9, fraction $1-2{\rightarrow}3:7$, fraction $3-5{\rightarrow}1:1$, fraction $6-9{\rightarrow}7:3$, fraction $10-13{\rightarrow}9:1$, fraction 14-16). Compound 2 was isolated from fraction 6 and compound 1 was separated from fraction 11 and 12. Compound 3 and 4 were purified from fraction 13. The isolated compounds were elucidated as quercetin-3-O-${\alpha}$-L-rhamnopyranoside (1), chlorogenic acid (2), quercetin-3-O-${\alpha}$-L-arabinofuranoside (3) and quercetin-3-O-${\beta}$-D-xylopyranoside (4) by the spectral and literature data, and by comparison with the authentic samples. These compounds were reported, for the first time, from the extracts of C. japonicum leaves. Also chlorogenic acid (2) has never been reported before in domestic tree species and can be used as an index compound for C. japonicum.

• Korean Journal of Veterinary Research
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• v.56 no.2
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• pp.85-89
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• 2016

We tested a set of conditions for obtaining optimal tissue quality in preparation for histology in samples of mouse brain. C57BL/6J mice were sacrificed and perfused with 4% paraformaldehyde, after which the brains were removed and dehydrated in 30% sucrose solution. The brains were then divided into four groups according to freezing temperature and usage of optimal cutting temperature (OCT) compound. Next, we stained the sectioned brain tissues with Harris hematoxylin and eosin Y and immunohistochemistry was performed for doublecortin. The best quality tissue was obtained at $-25^{\circ}C$ and by not embedding with the OCT compound. When frozen at $-25^{\circ}C$, the embedded tissue was significantly damaged by crystals, while at $-80^{\circ}C$ there were no meaningful differences between qualities of embedded- and non-embedded tissues. Overall, we identified a set of conditions to obtain quality frozen brain sections. Our developed protocol will help resolve matters associated with damage caused to sectioned brain tissue by crystal formation during freezing.

• Journal of Applied Biological Chemistry
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• v.42 no.3
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• pp.146-150
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• 1999

As a part of the integrated disease system in greenhouse, an antifungal fungus(AF1) was isolated from greenhouse soil. It exhibited strong inhibitory activites against Pythium ultimum, Phytophtora capsici, Rhizoctonia solani, Botrytis cinerea, and Fusarium oxysporum based on dual culture on 1/5 strength of potato dextrose agar between antagonistic fungus and several plant pathogens. The antagonistic fungus was identified as Chaetomium cochliodes, based on morphological characteristics; the body of the perithecium bears straight or slightly wavy, unbranched hairs, whilst the apex bears a group of spirally coiled hairs. To investigate antagonistic principles, antifungal compound was extracted and fractionated by different solvent systems. An antifungal compound was isolated as pure crystal from is culture filtrate using organic solvent extraction and column chromatography, followed by preparative thin layer chromatography. The chemical structure of the purified antifungal compound was identified as chaetoglobosin A based on the data obtained form $^1H-NMR$, $^{13}C-NMR$, DEPT 90, 135, $^1H-^1H$ COSY, $^1H-^{13}C$ COSY and EI/MS. $ED_{50}$ values of the chaetoglobosin A against P. ultimum, P. capsici, R. solani, B. cinerea and F. oxysporum were 1.98, 4.01, 4.16, 2.67 and 35.14 ppm, respectively.

• Journal of Biomedical Engineering Research
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• v.30 no.3
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• pp.233-240
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• 2009

Using a spatial compound imaging technique in a medical ultrasound imaging system, the average speed of sound in a medium of interest is measured, and imaging of its distribution is implemented. When the brightness reaches the highest level in an ultrasonic image obtained as the speed of sound used in focusing is varied, it turns out that the focusing has been accomplished satisfactorily and that the speed of sound which has been adopted becomes the sought-after average speed of sound. Because spatial compound imaging provides many different views of the same object, the adverse effect of erroneous speed-of-sound estimation tends to be more severe in compound imaging than in plain B-mode imaging. Thus, in compound imaging, the average speed of sound even in the case of speckled images can be accurately estimated by observing the brightness change due to different speeds of sound employed. Using this new method that offers spatial diversity, we can construct an image of the speed of sound distribution in a phantom embedded with a 10-mm diameter plastic cylinder whose speed of sound is different from that of the background. The speed of sound in the cylinder is found to be different from that of the surrounding medium.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.3
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• pp.217-222
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• 2013

We reported that ailanthoidol, a neolignan from Zanthoxylum ailanthoides and Salvia miltiorrhiza Bunge, inhibited inflammatory reactions by macrophages and protected mice from endotoxin shock. We examined the anti-inflammatory activity of six synthetic ailanthoidol derivatives (compounds 1-6). Among them, compound 4, 2-(4-hydroxyphenyl)-5-(3-hydroxypropenyl)-7-methoxybenzofuran, had the lowest $IC_{50}$ value concerning nitric oxide (NO) release from lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Compound 4 suppressed the generation of prostaglandin (PG) $E_2$ and the expression of inducible NO synthase and cyclooxygenase (COX)-2 induced by LPS, and inhibited the release of LPS-induced pro-inflammatory cytokines from RAW264.7 cells. The underlying mechanism of compound 4 on anti-inflammatory action was correlated with the down-regulation of mitogen-activated protein kinase and activator protein-1 activation. Compound 4 is potentially an effective functional chemical candidate for the prevention of inflammatory diseases.

• Journal of the Korean institute of surface engineering
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• v.40 no.6
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• pp.250-253
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• 2007

Plasma nitrocarburizing and plasma oxidizing treatments were performed to improve the wear and corrosion resistance of SKD 11 steel. Plasma nitrocarburizing was conducted for 12 h at $520^{\circ}C$ in the nitrogen, hydrogen and methane atmosphere to produce the $\varepsilon-Fe_{2-3}(N,C)$ phase. It was found that the compound layer produced by plasma nitrocarburising was predominantly composed of $\varepsilon-phase$, with a small proportion of $\gamma'-Fe_4(N,C)$ phase. The thickness of the compound layer was about $5{\mu}m$ and the diffusion layer was about $150{\mu}m$ in thickness, respectively. Plasma post oxidation was performed on the nitrocarburized samples with various oxygen/hydrogen ratio at constant temperature of $500^{\circ}C$ for 1 hour. The very thin magnetite($Fe_3O_4$) layer $1-2{\mu}m$ in thickness on top of the compound layer was obtained by plasma post oxidation. It was confirmed that the corrosion characteristics of the nitrocarburized compound layer could be further improved by the application of the superficial magnetite layer.