• Journal of the Korean Society of Safety
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• v.10 no.3
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• pp.68-80
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• 1995

A series of parametric calculations have been performed in order to investigate the short-term and short-range plume and puff behavior of toxic gaseous and solid pollutant dispersion in an open atmosphere. The simulation is made by the use of the computer program developed by this laboratory, in which a control-volume based finite-difference method is used together with the SIMPLEC algorithm for the resolution of the pressure-velocity coupling appeared In Wavier-Stokes equation. The Reynolds stresses are solved by the standard two-equation k-$\varepsilon$ model modified for buoyancy together with the RNG(Renormalization Group) k-$\varepsilon$ model. The major parameters considered in this calculation are pollutant gas density and temperature, the relative velocity of pollutants to that of the surrounding atmospheric air, and particulate size and density together with the height released. The flow field is typically characterized by the formation of a strong recirculation region for the case of the low density gases such as $CH_4$ and air due to the strong buoyancy, while the flow is simply declining pattern toward the downstream ground for the case of heavy molecule like the $CH_2C1_2$and $CCl_4$, even for the high temperature, $200^{\circ}C$. The effect of gas temperature and velocity on the flow field together with the particle trajectory are presented and discussed in detail. In general, the results are physically acceptable and consistent.

• Journal of Hydrogen and New Energy
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• v.22 no.5
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• pp.579-584
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• 2011

Sulfonated poly (ether sulfone)s containing BFBN were prepared from 2,3-bis(4-fluorophenyl)-2-butenedinitrile , 4,4-sulfonyldiphenol and sulfonated 4,4'-difluorodiphenylsulfone sodium salt using potassium carbonate, and followed acidification reaction with 1M $H_2SO_4$. BFBN was prepared from 4-fluorobenzylcyanide, $CCl_4$, NaOH using trimethylbenzylammoniumchloride . Sulfonated poly(ether sulfone)s containing BFBN were studied by FT-IR, $^1H$-NMR spectroscopy, and thermo gravimetric analysis (TGA). The water uptake of synthesized S-PBFBN membranes exhibit 31~62% compared with 28% of Nafion 211. The S-PBFBN membranes exhibit proton conductivities ($80^{\circ}C$, RH 100) of 53.8~117.4 mS/cm compared with 137.4 mS/cm of Nafion 211.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1512-1514
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• 2001

In this work, PZT thin films were etched as a function of $Cl_2$/Ar and additive $CF_4$ into $Cl_2$(80%)/Ar(20%). The etch rates of PZT films were 1600 $\AA$/min at $Cl_2$(80%)/Ar(20%) gas mixing ratio and 1973 $\AA$/min at 30% additive $CF_4$ into $Cl_2$(80%)/Ar(20%). Therefore the etch rate of PZT in $CF_4/Cl_2/Ar$ plasma is faster than in $Cl_2$/Ar. From XPS and SIMS analysis, metal halides and C-O, FCI and $CClF_2$ were detected. The etching of PZT films in Cl-based plasma is primarily chemically assisted ion etching and the remove of nonvolatile etch byproducts is the dominant step. Consequently, we suggest that the increase of Cl radicals and the volatile oxy-compound such as $CO_y$ are made by adding $CF_4$ into $Cl_2$/Ar plasma. Therefore, the etch rate of PZT in $CF_4/Cl_2/Ar$ plasma is faster than in $Cl_2$/Ar. The etched profile of PZT films was obtained above 70$^{\circ}$ by the SEM micrograph.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.4
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• pp.369-377
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• 2018

Spinal tuberculosis (ST) is the tuberculosis caused by Mycobacterium tuberculosis (Mtb) infections in spinal curds. Isoliquiritigenin (4,2',4'-trihydroxychalcone, ISL) is an anti-inflammatory flavonoid derived from licorice (Glycyrrhiza uralensis), a Chinese traditional medicine. In this study, we evaluated the potential of ISL in treating ST in New Zealand white rabbit models. In the model, rabbits (n=40) were infected with Mtb strain H37Rv or not in their $6^{th}$ lumbar vertebral bodies. Since the day of infection, rabbits were treated with 20 mg/kg and 100 mg/kg of ISL respectively. After 10 weeks of treatments, the adjacent vertebral bone tissues of rabbits were analyzed through Hematoxylin-Eosin staining. The relative expression of Monocyte chemoattractant protein-1 (MCP-1/CCL2), transcription factor ${\kappa}B$ ($NF-{\kappa}B$) p65 in lymphocytes were verified through reverse transcription quantitative real-time PCR (RT-qPCR), western blotting and enzyme-linked immunosorbent assays (ELISA). The serum level of interleukin (IL)-2, IL-4, IL-10 and interferon ${\gamma}$ ($IFN-{\gamma}$) were evaluated through ELISA. The effects of ISL on the phosphorylation of $I{\kappa}B{\alpha}$, $IKK{\alpha}/{\beta}$ and p65 in $NF-{\kappa}B$ signaling pathways were assessed through western blotting. In the results, ISL has been shown to effectively attenuate the granulation inside adjacent vertebral tissues. The relative level of MCP-1, p65 and IL-4 and IL-10 were retrieved. $NF-{\kappa}B$ signaling was inhibited, in which the phosphorylation of p65, $I{\kappa}B{\alpha}$ and $IKK{\alpha}/{\beta}$ were suppressed whereas the level of $I{\kappa}B{\alpha}$ were elevated. In conclusion, ISL might be an effective drug that inhibited the formation of granulomas through downregulating MCP-1, $NF-{\kappa}B$, IL-4 and IL-10 in treating ST.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.203-217
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• 2021

Background: Sea turtles, which are globally endangered species, have been stranded and found as bycatch on the Korean shore recently. More studies on sea turtles in Korea are necessary to aid their conservation. To investigate the spatio-temporal occurrence patterns of sea turtles on the Korean shore, we recorded sampling locations and dates, identified species and sexes and measured sizes (maximum curved carapace length; CCL) of collected sea turtles from the year 2014 to 2020. For an analysis of diets through stomach contents, we identified the morphology of the remaining food and extracted DNA, followed by amplification, cloning, and sequencing. Results: A total of 62 stranded or bycaught sea turtle samples were collected from the Korean shores during the study period. There were 36 loggerhead turtles, which were the dominant species, followed by 19 green turtles, three hawksbill turtles, two olive ridley turtles, and two leatherback turtles. The highest numbers were collected in the year 2017 and during summer among the seasons. In terms of locations, most sea turtles were collected from the East Sea, especially from Pohang. Comparing the sizes of collected sea turtles according to species, the average CCL of loggerhead turtles was 79.8 cm, of green turtles was 73.5 cm, and of the relatively large leatherback turtle species was 126.2 cm. In most species, the proportion of females was higher than that of males and juveniles, and was more than 70% across all the species. Food remains were morphologically identified from 19 stomachs, mainly at class level. Seaweeds were abundant in stomachs of green turtles, and Bivalvia was the most detected food item in loggerhead turtles. Based on DNA analysis, food items from a total of 26 stomachs were identified to the species or genus level. The gulfweed, Sargassum thunbergii, and the kelp species, Saccharina japonica, were frequently detected from the stomachs of green turtles and the jellyfish, Cyanea nozakii, the swimming crab, Portunus trituberculatus, and kelps had high frequencies of occurrences in loggerhead turtles. Conclusions: Our findings support those of previous studies suggesting that sea turtles are steadily appearing in the Korean sea. In addition, we verified that fish and seaweed, which inhabit the Korean sea, are frequently detected in the stomach of sea turtles. Accordingly, there is a possibility that sea turtles use the Korean sea as feeding grounds and habitats. These results can serve as basic data for the conservation of globally endangered sea turtles.

• Korean Journal of Oriental Medicine
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• v.14 no.1
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• pp.137-143
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• 2008

In this research, as a method for verifying the efficacy of Ssangwhatang and fungus-fermentated Ssangwhatang, a comparative study on the liver protection effect was conducted using animal experiments by inducing the liver toxicity with the $CC_{l4}$ treatment. Inducing the liver damage resulted in the increase in the serum AST and ALP activity, and one day administration of the test material($CCI_4$: 0.5 ml/kg/day) caused 520 IU/L of the ASP activity leading to 29% enhancement in comparison with the normal group and 93% and 81% reductions in the fungus-fermentated Ssangwhatang-administered groups, BFST1 and BFST2, respectively. ALT is 42 IU/L for the normal group and 99 IU/L for the negative control group leading to 135% enhancement. 15 ml/kg/day and 30 ml/kg/day administrations of fungus-fermented Ssangwhatang(BFST) resulted in 51% and 45% decreases in the ALT concentration, respectively. One day administration of 30 ml/kg Ssangwhatang and fungus-fermentated Ssangwhatang caused the LDH in the plasma to tend to decrease. $CCI_4$(1.0 ml/kg/day) administered at the 0th and 4th days led to the observation of the tendency toward the decrease in AST, ALT, and LDH contents. The results indicate that the function of Ssangwhatang is partly reinforced under the fungus-fermentated Ssangwhatang performed in order to verify the efficacy of Ssangwhatang' s effect on the recovery from fatigues.

• Korean Journal of Pharmacognosy
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• v.15 no.2
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• pp.91-97
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• 1984

The investigation was aimed to study the effect of ginseng ethanol extract on the hepatic ethanol-metabolizing enzyme activity in vivo. The extract (100mg/kg/day) was administered orally to Sprague-Dawley rats for $7{\sim}10$ days and their microsomal ethanol oxidizing system(MEOS) and catalase activities were measured. The MEOS activity in the rat treated with the extract was not significantly different from that of the normal group. Microsomal fraction containing MEOS was separated and the MEOS activity was measured after preincubation for 5, 60 and 180 min, respectively. There were no significant differences in MEOS activities between the normal and treated groups preincubated for 5, 60 and 180 min. The activity in the rat treated with single i.p. injection of 95% $CCl_4$ (0.5ml/kg) was decreased by 48%, compared to the normal group and in the rat treated with the extract (100mg/kg) for $7{\sim}10$ days, the decrease of the MEOS activity was potentiated. Catalase activity in the rat treated with the extract (100mg/kg) was similar to that obtained from the normal group.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1274-1274
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• 2001

An anharmonicity is a fundamental quantity shaping the potential for stretching OH vibration in phenol and its derivatives. The phenomenon is examined both by experimental and theoretical methods. FT-IR and NIR spectra of series of phenols derivatives were measured in the range of fundamental and first two Overtones of $_{s}(OH)$ Vibrations in $CCl_4$ solutions. The electronic influence of substituents on the analyzed frequencies is discussed and correlated with $pK_{a}$ parameters. Ab initio MP2/6-31G(d,p) and B3LYP/6-31G(g,p) calculations of the potential for proton movement in OH group were performed. Equilibrium structures were also determined. The frequencies of fundamental and overtones were calculated by Numerov-type procedure. The results of calculations are compared with the experimental data. The best linear correlations were obtained for the results of MP2/6-31G(d,p) calculations. It was shown that some structural parameters are especially sensitive on substitution. The linear correlations were found between those parameters and spectroscopic data. The results of calculation are compared with available crystallographic data.

• Korean Journal of Pharmacognosy
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• v.31 no.1
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• pp.45-50
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• 2000

The root of Pseudostellaria heterophylla Pax et Hoffm. (Caryophyllaceae) is a herbal medicine called Taejasam(太子蔘) and used as a good tonic in China that strengthens the functions of the lung and the stomach like Ginseng in Korea. It has been known to have the antitussive activity for tuberculosis, appetizing effect and antifatigue activity, and so on. Especially it has been known to generate body fluids for the severe thirst and the shortage of water in body after a febrile disease for a long time. Recently some components of cyclic peptides, pseudostellarins A,B,C,D,E,F,G, that inhibit the activity of tyrosinase, were separated from this root. In this report several biological activities including acute toxicity, analgesic activity, antifatigue activity, bile juice increasing activity, hepatoprotective activity and antiinflammatory activity were investigated. These results showed as such; $LD_{50}$ of methanol extracts was above 10,000 mg/kg. The analgesic effect was revealed in the writhing test using rats. The BuOH fractions showed a prominent antifatigue effect against immobilized stress, significant hepatoprotective activities against $CCl_4$ intoxication and inhibitory effect on carrageenin-induced edema in rat's paw.

• Journal of Food Hygiene and Safety
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• v.16 no.1
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• pp.41-47
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• 2001

The purpose of this study was to elucidate the effects of green tea catechins (GTC) on the lipid peroxidation and superoxide dismutase (SOD). GTC showed the high SOD activity, while sitgnificantly inhibited the peroxide value of linoleic acid (93%) and lipid peroxidation (84%) from rat liver microsomal fraction induced by Fe$^{2+}$ascorbate system. The effects of GTC on the SOD and catalase activities, and lipid peroxidation after oral administration were investigated. GTC (50 mg/kg) significantly increased SOD (62%) and catalase activities (75%), while significantly inhibited the lipid peroxidation (52%) of rat liver microsome in a dose-dependent manner. These results suggest that GTC has the antioxidative effect which is rotated to the prevention of aging and cancer.r.