• Journal of Microbiology and Biotechnology
• /
• v.20 no.3
• /
• pp.510-512
• /
• 2010

A series of thiobarbituric acid derivatives were constructed and evaluated for inhibitory activity on hepatitis C virus NS5B polymerase. In biochemical assays using purified viral polymerase and RNA template, the $IC_{50}$ value was improved to 0.41 ${\mu}M$ from the original compound's 1.7 ${\mu}M$ value. In HCV sub genomic replicon assay, the $EC_{50}$ value was improved to 3.7 ${\mu}M$ from the original compound's 12.3 ${\mu}M$ value. $CC_{50}$ was higher than 77 ${\mu}M$ for all compounds tested, suggesting that they are useful candidates for anti-HCV therapy.

• Korean Journal Plant Pathology
• /
• v.10 no.2
• /
• pp.119-122
• /
• 1994

Effects of organophosphorus fungicides on cutinase activity from Glomerella cingulata causing apple anthracnose and infection of apple were investigated. Diisoprophylfluorophosphate (DFP) inhibited the enzyme activity indicating that catalysis involves an active serine. In inhibition of the enzyme activity by organophosphorus fungicides, I50 (molar concentration of fungicide at which the enzyme activity is inhibited 50%) of Hinosan and Kitazin P were 26.3 $\mu$M and 427.7 $\mu$M, respectively. At concentration of 10-3 M DFP and organophosphorus fungicides, the infection of G. cingulata was inhibited to 5% in comparison with 15% infection at the unwounded healthy control, but increased to 30% when added with 1 mg/ml of cutinase. Mycelial growth was 36 mm in colony diameter on the medium added with 10-4M of hinosan in comparison with 90 mm of the untreated control, but was 90 mm on the medium added with 10-4M of kitazin P showing lower inhibition than hinosan. The spore germination was more than 60% at all the concentrations of both fungicides.

• Journal of Ginseng Research
• /
• v.33 no.4
• /
• pp.311-315
• /
• 2009

Potassium phosphonate inhibited less mycelial growth of Phytophthora cactorum in vitro than metalaxyl-M. But the net protection rate in leaflet test and whole plant pot test was greater in potassium phosphonate than metalaxyl-M. P. ginseng appeared to have an induced resistance against P. cactorum with phosphonate around 50~100 ppm.

• Natural Product Sciences
• /
• v.11 no.3
• /
• pp.119-122
• /
• 2005

In the course of searching for hepatoprotective agents from natural products, four compounds were isolated from the MeOH extract of Sanguisorbae Radix, as guided by their DPPH free radical scavenging activity. The structures were determined as 4,5-dimethoxy-3-hydroxybenzoic acid methyl ester (1), (+)-gallocatechin (2), methyl $6-O-galloyl-{\beta}-D-glucopyranoside$ (3), and pomolic acid $3-O-[{\alpha}-L-arabinopyranoside]-28-O-[{\beta}-D-glucopyranosyl]$ ester (ziyu-glycoside I) (4). Compounds 2 and 3 showed significant DPPH free radical scavenging effects, exhibiting $IC_{50}$ values of 11.4 and $13.0\;{\mu}M$, respectively. L-Ascorbic acid was used as a positive control and exhibited the $IC_{50}$ value of $50.3\;{\mu}M$. In evaluation of the hepatoprotective activity of the isolated compounds on drug-induced cytotoxicity, compound 2 showed the significant hepatoprotective effect with the $EC_{50}$ value of $91.84\;{\pm}\;11.0\;{\mu}M$ on tacrine-induced cytotoxicity in Hep G2 cells, while silybin, a positive control, exhibited $EC_{50}$ value of $122.4\;{\pm}\;12.5\;{\mu}M$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.8
• /
• pp.737-743
• /
• 2006

[ $Li[Co_{0.50}Li_{0.17}Mn_{0.33}]O_2$ ] powder was prepared using a simple combustion method. specially, ratio of 2:1, 3:2, 1:1, 2:3, 1:2 was adopted as acetate source/nitrate source. The diffraction pattern of $Li[Co_{0.50}Li_{0.17}Mn_{0.33}]O_2$ powder showed that this compound could be classified as hexagonal $a-NaFeO_2$ structure (space group : $R\bar{3}m$). The size of powder was less than $1{\mu}m$. Small particle size of cathode powder would give a good ionic and electronic conductivity to cathode electrode, which made of cathode powder. As the increase of nitrate source-ratio, discharge capacity of $Li[Co_{0.50}Li_{0.17}Mn_{0.33}]O_2$ at high charge-discharge rate was increased. When the ratio of acetate source/nitrate source was 1:2, discharge capacity at 10 C rate (2000 mA/g) was 180 mAh/g. It was $10{\sim}15%$ larger than that of powder, which have 2:1 as acetate source/nitrate ratio.

• Journal of Haehwa Medicine
• /
• v.10 no.1
• /
• pp.109-114
• /
• 2001

To evaluate the antitumor activity of Paridis Rhizoma(PR), studies were done experimentally. The results were obtained as follows: 1. In cytotoxicity against MCF-7, SK-OV-3, HCT15, concentration inhibiting cell growth up to below 50% of control was recognized at $100-200{\mu}g/m{\ell}$ of PR and also against A549, XF498 was recognized at $50-100{\mu}g/m{\ell}$. 2. In Inhibitory effect on activity of DNA topoisomerase I, the $IC_{50}$ was shown $50-100{\mu}g/m{\ell}$ of PR. 3. The concentration inhibiting adhesion of A549 and SK-OV-3 to complex extracellular matrix up to below 50% of control was recognized at $10-100{\mu}g/m{\ell}$ of PR. 4. The T/C% was 137.9 in PR-treated group in S-180 bearing ICR mice. From above results it was concluded that PR could be usefully applied for the prevention and treatment of cancer.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.15 no.2
• /
• pp.171-177
• /
• 1982

Optical properties of sea water were studied in the western channel of the Korea Strait, based on the data obtained from fifteen oceanographic stations in July, 1980. Submarine daylight intensity was measured at intervals of 5m depth in the upper 70m layer by using the underwater irradiameter (Kahlsico $\#268_{WA}360$). The mean absorption coefficients of the sea water were shown as $0.098(0.063\sim0.183),\;0.129(0.090\sim0.270), 0.081(0.044\sim0.142),\;and 0.087(0.036\sim0,142)$ for clear, red, green, and blue color respectively. The transparency ranged from 11.5 to 24m(mean 18.3m). The mean water color in this area was $3.5(3\sim4)$ in Forel scales. The relation between absorption coefficient $(\kappa)$ and transparency (D) was $\kappa=1.72/D,\;\kappa=2.33/D,\;\kappa=1.41/D,\;and \kappa=1.44/D$ for clear, red, green, and blue color respectively. The rates of light penetration for clear, red, green, and blue color in four different depths were computed with reference to the surface light intensity respectively. The mean rates of light penetration in proportion to depths were as follows; clear : $57.90\% (5m),\;23.40\%\;(15m),\;6.23\%\;(30m),\;1.00\%\;(50m).$ $red\;:\;48.95\%\;(5m),\;14,81\%\;(15m),\;2.76\%\;(30m),\;0.28\%\;(50m).$ $green:\;63.20\%\;(5m),\;30.47\%\;(15m),\;10.03\%\;(30m),\;2.24\%\;(50m).$ $blue\;:\;62.70\%\;(5m),\;30.00\%\;(15m),\;9.75\%\;(30m),\;1.70\%\;(50m)$

• Journal of Pharmacopuncture
• /
• v.19 no.4
• /
• pp.329-335
• /
• 2016

Objectives: Safranal is a pharmacologically active component of saffron and is responsible for the unique aroma of saffron. The hypotensive effect of safranal has been shown in previous studies. This study evaluates the mechanism for the vasodilatory effects induced by safranal on isolated rat aortas. Methods: To study the vasodilatory effects of safranal (0.2, 0.4 and 0.8 mM), we contracted isolated rat thoracic aorta rings by using $10^{-6}-M$ phenylephrine (PE) or 80-mM KCl. Dimethyl sulfoxide (DMSO) was used as a control. The vasodilatory effect of safranal was also evaluated both on intact and denuded endothelium aortic rings. Furthermore, to study the role of nitric oxide and prostacyclin in the relaxation induced by safranal, we incubated the aortic rings by using L-NAME ($10^{-6}M$) or indomethacin ($10^{-5}M$), each for 20 minutes. Results: Safranal induced relaxation in endothelium-intact aortic rings precontracted by using PE or KCl in a concentration-dependent manner, with a maximum relaxation of more than 100%. The relaxant activity of safranal was not eliminated by incubating the aortic rings with L-NAME ($EC_{50}=0.29$ vs. $EC_{50}=0.43$) or with indomethacin ($EC_{50}=0.29$ vs. $EC_{50}=0.35$), where $EC_{50}$ is the half maximal effective concentration. Also, the vasodilatory activity of safranal was not modified by endothelial removal. Conclusion: This study indicated that relaxant activity of safranal is mediated predominantly through an endothelium-independent mechanism.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.13 no.2
• /
• pp.31-39
• /
• 1993

It has not been performed to inspect the underclad cracking of nuclear pressure vessel in Korea since there is no code requirements for inspection. However, underclad cracks in nuclear pressure vessels have been reported since the early 1970s. The aim of this experiment is to find the suitable ultrasonic inspection techniques for underclad cracking. The various transducers, for example $70_{\backprime}$ refracted longitudinal wave, 50/70 multibeam, SLIC-40, SLIC-50, are used in this investigation. Experiments on prescreening blocks and a demonstration block under the same condition as in the nuclear power pressure vessels show that the $70_{\backprime}$ refracted longitudinal wave method is the best one for the length evaluation and also gives a good signal pattern for detection of the crack, while the 50/70 multibeam transducer is more effective for the detection of underclad cracking. On the other hand, the SLIC-50 transducer using M-SPOT(Satellite Pulse Observation Technique) and M-PET (Peak-Echo Technique) methods is the most effective one for the depth of underclad crack estimation.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.41 no.1
• /
• pp.1-6
• /
• 2008

The changes in osmolality and the gene expression profiles of prolactin (PRL) and growth hormone (GH) with rapid changes in salinity were compared in the eel (Anguilla japonica), crucian carp (Carassius carassius), and masu salmon (Oncorhynchus masou). Fish stocked in freshwater (FW) were abruptly transferred to experimental tanks containing FW, 50% seawater (50% SW), or 100% SW (SW). Blood samples and pituitary glands were collected 2 and 24 hrs after the exposure. No mortality was observed in SW eel (n=6), whereas all of the crucian carp (n=6) and two masu salmon (n=6) exposed to SW died after land 24 hrs, respectively. The PRL mRNA levels of the eel and masu salmon decreased in 50% SW and SW compared to those of the fish kept in FW after 24 hrs, whereas the PRL levels of crucian carp were higher in 50% SW than in FW. Unlike the PRL mRNA levels, the GH mRNA levels of the eel did not differ significantly among three different salinities, while the GH mRNA levels of crucian carp and masu salmon increased significantly in 50% SW and SW after 24 hrs. The serum osmolalities increased marginally in the eel and masu salmon in 50% SW at 24 hrs (19% and 9%, respectively), whereas those of crucian carp increased abruptly in 50% SW (50% increase). These results suggest that the synthesis of PRL and GH is important in relation to the osmoregulatory system with environmental changes in salinity.