• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.373-380
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• 1996

Recently we reported that GS 386, 1-(4'-methoxybenzyl)-6,7-dimethoxy-3,4-dihydroisoquinoline, inhibited amplitude of the $Ca^{2+}$ current by reducing the probability of $Ca^{2+}$ channel opening without changing channel kinetics in isolated rabbit atrial myocyte. In the present study, further investigation of the mechanism of action of GS 386 was performed using isolated rat trachealis. GS 386 concentration-dependently relaxed rat trachealis contracted by carbachol $(0.3{\mu}M)$ and high $K^+$(65.4 mM) with $IC_{50}$ 5.24 and 5.67 ${\mu}M$, respectively. Verapamil inhibited more effectively the high $K^+-contracted$ tissues than those with carbachol in the rat trachealis muscle. In $Ca^{2+}-free$ media, $Ca^{2+}-induced$ contraction was inhibited by GS 386. Furthermore, high concentration of GS 386 $(100{\mu}M)$ but not verapamil, attenuated a phasic contraction induced not only by carbachol but also caffeine, indicating that GS386 can enter into the cytoplasm where it may exert secondary actions on internal sites of the muscle, such as sarcoplasmic reticulum. Moreover, GS 386 showed verapamil-resistant component of relaxation and increased cAMP levels in rat trachal smooth muscle. These results suggest that the mechanism of action of GS 386 attributes to not only $Ca^{2+}$ antagonistic action but also weak phosphodiesterase inhibitory action.

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.285-290
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• 1995

This study was undertaken to define the varying responses of vascular smooth muscle to different wavelengths of ultraviolet radiation and to relate them to the changes in cyclic GMP contents. The ring preparations of rat thoracic aorta with intact or removed endothelium were irradiated with the ultraviolet or visible light (UVR) of wavelengths in step of 10 nm between 250 and 500 nm from xenon lamp of a spectrofluorometer, and the changes in vascular tension were recorded. For cyclic GMP assay, the preparations, pretreated with phenylephrine as in the tension experinents, were frozen after irradiation and homogenated in trichloroacetic acid. The supernatant was extracted with ether and the cyclic GMP contents were measured with radioimmunoassay. In the endothelium-intact preparations, biphasic responses, vasoconstriction (UVR-contraction) followed by vasodilatation (UVR-dilatation), were observed. The maximal UVR-contraction was observed at 320 nm, while the maximal vasodilatation was elicited at 420 nm. In the endothelium-removed rings, however, only vasodilatation was observed, with the maximal vasodilatation taking place at 370 nm. The cyclic GMP contents were not affected by the Irradiation with 320 nm for 30 sec or 1 min in the endothelium-intact preparations, while it was significantly increased by 380 and 420 nm. In the endothelium-removed preparations, UVR of 370 nm markedly increased the cyclic GMP contents. The present study indicates that the increase in cyclic GMP is closely related to vasodilatation induced by UVR of 420 nm in the endothelium-intact or 370 nm in the denuded preparations, whereas it is not involved in the vasoconstriction induced by UVR of 320 nm in the intact rings, and the mechanism leading to UVR-contraction remains to be clarified. These observations suggest that nitric oxide-cyclic GMP system is closely related to the UVR-dilatation in rat aortic preparation, while it is not involved in the UVR contraction.

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.291-297
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• 1995

The objectives of this study is to compare the inhibitory mechanism of sodium nitroprusside and forskolin on the phorbol ester, activator of protein kinase C (PKC), -induced contractions in rat aorta. $0.1\;{\mu}M$ phorbol dibutyrate (PDBu) induced sustained contractions and increased phosphorylations of myosin light chain (MLC) time-dependently. At 30 min, the contractions and phosphorylations of MLC by PDBu were augmented maximally and remained constant. Moreover, $^{45}Ca^{2+}$ uptake was increased 30 min after PDBu stimulation from resting values. Sodium nitroprusside which activates guanylyl cyclase followed by increasing cGMP, inhibited the PDBu-induced contractions concentration-dependently. On the other hand, forskolin which activates adenylyl cyclase followed by increasing cAMP, also inhibited the PDBu-induced contractions concentration-dependently. However, sodium nitroprusside was more potent to inhibition of the PDBu-induced contractions than forskolin. Sodium nitroprusside inhibited $^{45}Ca^{2+}$ uptake by PDBu stimulation. Forskolin also inhibited $^{45}Ca^{2+}$ uptake by PDBu stimulation. Sodium nitroprusside and forskolin inhibited the phosphorylations of MLC by PDBu, respectively. However, sodium nitroprusside was more potent to inhibition of phosphorylations of MLC by PDBu than forskolin. From these results, Sodium nitroprusside via cGMP or forskilin via cAMP may reduce myoplasmic $Ca^{2+}$ followed by suppression of phosphorylations of MLC of PKC-mediated contractions, which results in vasodilation. However, cGMP may play a role more importantly than cAMP on the regulation of protein kinase C-mediated contraction in vascular smooth muscle.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.429-433
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• 2014

In 2012, a pink mold rot was observed on apple (Malus pumila var. dulcissima Koidz.) at the Wholesale Market for Agricultural Products, Jinju, Korea. The first symptom of pink mold rot on apple fruit is a water-soaked appearance of the affected tissue and surface fruit formed pink mold rot, then became brown and produced a mass of powdery pink conidia spores. Colony was fast growing colonies, pinksh, zonate in diurnal rhythm, powdery from conidia. Optimum temperature for mycelial growth was $25^{\circ}C$. Conidia were hyaline, smooth, two-celled, thick-walled conidia with truncate bases, ellipsoidal to pyriform, and characteristically held together zig-zag chains and $12-26{\times}8-12{\mu}m$ in size. Conidiophore was erect, colorless, unbranched, and $4-5{\mu}m$ wide. On the basis of mycological characteristics, pathogenicity test, and molecular identification with the ITS region, the causal fungus was identified as Trichothecium roseum (Pers.) Link ex Gray.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.4
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• pp.194-204
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• 2011

This study was carried out to compare the histopathological differences of liver lesions in carbon tetrachloride ($CCI_4$), dimethylnitrosamine (DMN), thioacetamide (TAA) and bile duct ligation (BDL)-induced rats. $CCl_4$, DMN and TAA were administered intraperitoneally and conducted bile duct ligation for 4 weeks to induce hepatic fibrosis. Indices of liver cell injury (steatosis, hydropic degeneration, bile duct hyperplasia, hemorrhage & hemosiderin deposition), the extent of liver fibrosis (fibrotic area) and the rate of regeneration (number of PCNA-positive cells) were investigated in each group. Liver tissues were stained with hematoxylin-eosin (HE), sirius red, prussian blue and immunostained with ${\alpha}$-smooth muscle actin (${\alpha}$-SMA), transforming growth factor-${\beta}1$ (TGF-${\beta}1$), proliferative cell nuclear antigen (PCNA), and quantified using a computerized image analysis system. Liver cell steatosis was significantly increased in $CCl_4$ and TAA groups, and hydropic degeneration and bile duct hyperplasia were significantly increased in TAA and BDL groups when compared with that in normal control, respectively. Fibrosis area was significantly increased in all four groups, especially in $CCl_4$ group. Correlation between ${\alpha}$-SMA and TGF-${\beta}1$ expressions in four groups was good. Hemorrhage area in liver parenchyma was significantly increased in DMN group only when compared with that in normal control, while hemosiderin deposition area was significantly increased in TAA and BDL groups as well as DMN group. The Number of PCNA-positive cells was significantly increased in all four groups, especially in TAA group. These results indicate that the duration and methods of hepatotoxic drug treatment are very important factors to make plans for animal experimentation on the induction of hepatic fibrogenesis in rats.

• Journal of Food Hygiene and Safety
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• v.13 no.3
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• pp.252-257
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• 1998

Bamboo salt has been used as a traditional remedy for gastric ulcer and gastro-intestinal disorders. It is produced by baking the salt packed in bamboo cylinder nine times under the fire of pine tree. Three of commercially available bamboo salt products (bamboo salt A, B, and C) were characterized by qualitative and quantitative analyses using inductively coupled plasma (ICP) spectrometer, ion chromatograph (IC), X-ray diffractometer (XRD), and electron microscope (EM). Compared with crude salt, the contents of iron, silicon, potassium, and phosphate in the bamboo salt products were higher whereas the sulfate content was lower. Water-insoluble fraction of bamboo salts contained the following compounds; MgO, $SiO_2,\;Mg_2Si0_4,\;and\;CaMgSi0_4$. The study on the microscopic structures of the bamboo salts were shown to have smooth surface and fused shape compared with crude salt. Among the three bamboo salt products, product A was used to test a possible inhibitory effect on gastric acid secretion. Each test material (bamboo salt A, crude salt, and reagent-grade NaCl) was given orally to Sprague-Dawley rats at doses of 0.2, 1.0, and 2.0 g/kg for 28 days before pyrolus ligation. Twenty four hours after the last administration of the test materials, volume, pH, total acidity, and pepsin activity of gastric juice were measured by the Shay-ligation method. No significant differences were observed in the secretion of gastric acid between treated groups (bamboo salt-, crude salt- and reagent-grade NaCI-treated groups) and control group (distilled water-treated group). This result demonstrated that bamboo salt did not exert anti-ulcer activities in experimental animals used in the present study.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.5
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• pp.543-550
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• 2011

The gravity anomaly is a basic geophysical data applied in various fields such as geophysics, geodesy and national defense. In general, the gravity anomaly is used through a interpolation process based on the constructed database. The gravity variation, however, is appeared in various shapes depending on the topography and the density of the underground structures. Therefore, the interpolation could lead to a large differences if the gravity fields do not satisfy the assumptions on the signal behavior like linear or a certain degree polynomials. Furthermore, the interpolation does not reflect the physical characteristics of the gravity such as the harmonic condition. In this study, the gravity modeling using the plane Fourier series and radial basis functions are performed to overcome the problems in the usual interpolation. The results of the modeling is analyzed for the case of the gravity referenced navigation focused on the signal characteristics. Based on the study, it was found that the results from modeling are not much different to that from the interpolation in a smoothly varied area. In case of the highly varied area, however, a large differences are appeared among the three methods. Especially, the Fourier series shows the most smooth variations in the modeled gravity values while the highest variations appeared in the interpolation. Applying to the gravity referenced navigation, it was found that the modeling is more effective in calculation cost. It is considered that the results from this study provides a basis on effective modeling of the gravity fields in terms of the signal characteristics and resolution for various application fields.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.619-626
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• 2020

The development of new antifreeze mixtures containing non-amine-type corrosion inhibitors, which considers environmental protection, has become a major issue. In this study, four non-amine-type corrosion inhibitors were synthesized and used to produce five kinds of new antifreeze for automobiles to evaluate the rate of copper corrosion. The effects were evaluated by the weight change, surface observation, roughness measurement, and measurement of copper elution in the solution. The amount of copper eluted measured by ICP from Sample 4 was small, and the elution rate was prolonged. Sample 4 showed the best anti-corrosion performance owing to a corrosion suppression effect by passivating copper because the metal surface was smooth after the test, and the corrosion product layer was formed evenly on the surface as small local corrosion was observed. The major corrosion inhibitor added to Sample 4 was 1-aminomethyl(N',N'-di(2-hydroxyethyl)benzotrazole, which contained a certain amount in Sample 5 to show relatively high local corrosion but passivation in progress. Therefore, among the four corrosion inhibitors, 1-aminomethyl(N',N'-di(2-hydroxyethyl)benzotrazole had the highest corrosion inhibitory effect. This corrosion inhibitor prevents corrosion by promoting the passivation of copper on the antifreeze.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.4
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• pp.321-336
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• 2012

The shear behavior at the particle/surface interface such as rock joint can determine the mechanical behavior of whole structure. Therefore, a fundamental understanding of the mechanisms governing its behavior and accurately estimation of the interface strength is essential. In this paper, PFC, a numerical analysis program of discrete element method was used to investigate the effects of the surface roughness crushing on interface strength. The surface roughness was characterized by smooth, intermediate, and rough surface, respectively. Particle shape was classified into one ball model of circular shape and 3 ball model of triangular shape. The surface shape was modelled by wall model of non-crushing surface and ball model of crushing surface. The results showed that as the bonding strength of ball model decreases, lower interface strength is induced. After the surface roughness crushing was occurred, the interface strength tended to converge and higher bonding strength induced lower surface roughness crushing. Higher friction angle was induced in wall model and higher surface roughness induced the higher friction angle. From these findings, it is verified that the surface roughness and surface roughness crushing effect on the particle/surface interface shear behavior.

• Journal of Microbiology and Biotechnology
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• v.30 no.4
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• pp.526-532
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• 2020

A bacterial strain, designated B301^T and isolated from raw chicken meat obtained from a local market in Korea, was characterized and identified using a polyphasic taxonomic approach. Cells were gram-negative, non-motile, obligate-aerobic coccobacilli that were catalase-positive and oxidase-negative. The optimum growth conditions were 30℃, pH 7.0, and 0% NaCl in tryptic soy broth. Colonies were round, convex, smooth, and cream-colored on tryptic soy agar. Strain B301^T has a genome size of 3,102,684 bp, with 2,840 protein-coding genes and 102 RNA genes. The 16S rRNA gene analysis revealed that strain B301^T belongs to the genus Acinetobacter and shares highest sequence similarity (97.12%) with A. celticus ANC 4603^T and A. sichuanensis WCHAc060041^T. The average nucleotide identity and digital DNA-DNA hybridization values for closely related species were below the cutoff values for species delineation (95-96% and 70%, respectively). The DNA G+C content of strain B301^T was 37.0%. The major respiratory quinone was Q-9, and the cellular fatty acids were primarily summed feature 3 (C_16:1 ω6c/C_16:1 ω7c), C_16:0, and C_18:1 ω9c. The major polar lipids were phosphatidylethanolamine, diphosphatidyl-glycerol, phosphatidylglycerol, and phosphatidyl-serine. The antimicrobial resistance profile of strain B301^T revealed the absence of antibiotic-resistance genes. Susceptibility to a wide range of antimicrobials, including imipenem, minocycline, ampicillin, and tetracycline, was also observed. The results of the phenotypic, chemotaxonomic, and phylogenetic analyses indicate that strain B301^T represents a novel species of the genus Acinetobacter, for which the name Acinetobacter pullorum sp. nov. is proposed. The type strain is B301^T (=KACC 21653^T = JCM 33942^T).