• Journal of the Korean Applied Science and Technology
• /
• v.34 no.3
• /
• pp.443-450
• /
• 2017

This study was done to investigate the protective effects of ethanol extract puerariae radix(Pr) on carbon tetrachloride($CCl_4$) intoxicated rats. Male sprague Dawley rats(200~210g)was used. experimental groups were divided into normal group, $CCl_4$-control group, and ethanol extract $CCl_4$-treated group. $CCl_4$-treated groups were injected with $CCl_4$ 0.6mg/kg.b.w(i.p). The activities of Alanine aminotransferase(ALT), Aspartate aminotransferase(AST), Alkaline phosphatase(ALP), Glutamyltranspeptidase(${gamma}$-GT), Lactate dehydrogenase(LDH) in extract pretrated group was significantly decreased(p<0.05) compared to the $CCl_4$-control group. The contents of triglyceride, cholesterol and lipid peroxide were significantly decreased(p<0.05). whereas content of HDL-choresterol was significantly increased.(p<0.05). In addition, activities of hepatic catalase(CAT), glutathione peroxidase(GSH-Px) in the extract pretreated rats were significantly decreased(p<0.05) compared to the $CCl_4$-control group. but the content of glutathione(GSH) was significantly increased(p<0.05). These results suggest that extract of puerariae radix(Pr) has hepatoprotective effect in the $CCl_4$-intoxicated rats.

• Journal of the Korean Institute of Gas
• /
• v.19 no.2
• /
• pp.29-36
• /
• 2015

This study is an 1-D numerical study prior to modification of diesel engine for power plants to natural gas/diesel dual fuel engine using GT-Power with 1.5MW diesel engine for power generation. Natural gas injector was installed to intake manifold for dual fuel engine model. Effects on engine performance and characteristics were investigated when dual fuel is used in unmodified diesel engine. The analysis was done under 5 conditions from 0% to 40% of mixing rate on 720RPM engine speed. As a result of research, the engine performance was decreased as increasing ratio of natural gas. Engine brake power was decreased by 18.4% under 40% mixing rate condition. To clarify the reason, effects of injection timing and period were evaluated with DOE method. Considering this result, optimization was done for these parameters. Also, comparison between performances of dual fueled engine and diesel engine was made after optimizing the timing of injection by DOE method. As a result, engine brake power was decreased by 8.55% under mixing rate 40% condition showing 12.5% improvement.

• Journal of applied mathematics & informatics
• /
• v.31 no.5_6
• /
• pp.669-676
• /
• 2013

Let $a$ and $b$ be two even integers with $2{\leq}a<b$, and let k be a nonnegative integer. Let G be a graph of order $n$ with $n{\geq}\frac{(a+b-1)(a+b-2)+bk-2}{b}$. A graph G is called an ($a,b,k$)-critical graph if after deleting any $k$ vertices of G the remaining graph of G has an [$a,b$]-factor. In this paper, it is proved that G is an ($a,b,k$)-critical graph if $${\mid}N_G(X){\mid}&gt;\frac{(a-1)n+{\mid}X{\mid}+bk-2}{a+b-1}$$ for every non-empty independent subset X of V (G), and $${\delta}(G)>\frac{(a-1)n+a+b+bk-3}{a+b-1}$$. Furthermore, it is shown that the result in this paper is best possible in some sense.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.8
• /
• pp.1139-1147
• /
• 2014

We investigated whether or not Schisandra chinensis (SC), a traditional herbal medicine, has protective effects against alcohol-induced fatty liver and blood alcohol clearance. Two tests focused on acute intoxication and chronic ethanol treatment were carried out. For the chronic ethanol treatment test, rats were fed ethanol by intragastric administration everyday for 8 weeks to induce alcoholic fatty liver. Ethanol treatment significantly increased blood alcohol concentration at 90 min after acute ethanol intoxication. Compared with the two ethanol-treated groups, rats administered ethanol along with SC extracts showed an approximately 13% increased blood alcohol clearance rate at 360 min. Chronic ethanol treatment significantly increased serum and hepatic triglyceride (TG) levels, and caused fatty degeneration of liver. Ethanol treatment also elevated the serum total-cholesterol (TC) level. However, after feeding of ethanol plus SC extracts, ethanol-induced elevation of hepatic TG levels reversed, whereas elevation of serum TG and TC levels was not observed after treatment with SC extracts. Ethanol treatment significantly increased ${\gamma}$-GT, aspartate aminotransferase, and alanine aminotransferase activities after 8 weeks. Compared with the ethanol-fed group, rats administered ethanol plus SC extracts for 4 weeks showed attenuated fatty degeneration as well as decreased hepatic function test values. SC administration also significantly increased intracellular lipid accumulation in hepatocytes and reduced steatosis score and hepatic TG levels, as measured by biochemical and histolopathological analyses. Our results indicate that the protective effects of SC are accompanied by a significant decrease in hepatic TG levels, thereby suggesting SC has the ability to prevent ethanol-induced fatty liver, by reducing hepatic TG and enzyme levels in alcoholic rats.

• Journal of applied mathematics & informatics
• /
• v.31 no.5_6
• /
• pp.747-767
• /
• 2013

In this paper we have constructed a mathematical model of alcohol abuse which consists of four compartments corresponding to four population classes, namely, moderate and occasional drinkers, heavy drinkers, drinkers in treatment and temporarily recovered class. Basic reproduction number $R_0$ has been determined and sensitivity analysis of $R_0$ indicates that ${\beta}1$ (the transmission coefficient from moderate and occasional drinker to heavy drinker) is the most useful parameter for preventing drinking habit. Stability analysis of the model is made using the basic reproduction number. The model is locally asymptotically stable at disease free or problem free equilibrium (DFE) $E_0$ when $R_0&lt;1$. It is found that, when $R_0=1$, a backward bifurcation can occur and when $R_0&gt;1$, the endemic equilibrium $E^*$ becomes stable. Further analysis gives the global asymptotic stability of DFE under some conditions. Our important analytical findings are illustrated through computer simulation. Epidemiological implications of our analytical findings are addressed critically.

• 한국해양학회지
• /
• v.22 no.4
• /
• pp.271-278
• /
• 1987

Attempts were made to elucidate the responsible toxin in mussel Mytilus sp. which caused a food pisoning incident in March 1986 in Pusan, Korea. Two persons were dead and 15 persons intoxicated in the incident. The mid-gut glands of the mussel collected were extracted with dichlorlmethane, filtered through a Diaflo ulteafiltration membrane, and then purified by chromatography on Bio-Gel P-2 and Bio-Rex 70. The toxic fractions obtained were analysed by electrophoresis, TLC and ion-pairing reversed phase HPLC analyses. The results showed that the fractions contained GTW$\_$1-4/ as the major component, along with neoSTX, PX$\_$1,2/ as the minor. It was concluded from these results that the causative mussel toxin of the above food poisoning was PSP.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 1999.11a
• /
• pp.34-50
• /
• 1999

A cDNA encoding chicken interferon-gamma (chIFN-${\gamma}$) was amplified from P34, a CD4$^{+}$ T-cell hybridoma by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into pUC18. THe sequences of cloned PCR products were determined to confirm the correct cloning. Using this cDNA as probe, chicken genomic library from White Leghorn spleen was screened. Phage clones harboring chicken interferon-gamma (chIFN-${\gamma}$) were isolated and their genomic structure elucidated. The chIFN-${\gamma}$ contains 4 exons and 3 introns spanning over 14 kb, and follows the GT/AG rule for correct splicing at the exon/intron boundaries. The four exons encode 41, 26, 57 and 40 amino acids, respectively, suggesting that the overall structure of IFN-${\gamma}$ is evolutionairly conserved in mammalian and avian species. The 5’-untranslated region and signal sequences are located in exon 1. Several AT-rich sequences located in the fourth exon may indicate a role in mRNA turnover. The 5’-flanking region contains sequences homologous to the potential binding sites for the mammalian transcription factors, activator protein-1(AP-1) activator protein-2(AP-2) cAMP-response element binding protein(CREB), activating transcription factor(ATF), GATA-binding fator(GATA), upstream stimulating factor(USF), This suggests that the mechanisms underlying transcriptional regulation of chicken and mammalian IFN-${\gamma}$ genes may be similar.r.

• Korean Journal of Applied Biomechanics
• /
• v.23 no.1
• /
• pp.19-24
• /
• 2013

The aim of the study was a quantitative analysis of elite athlete's $540^{\circ}$ Dwihuryeochagi and effects of ground movements to the jumping height and kicking velocity. Eleven elite players(Taekwondo demonstration team) participated in this study. In order to get the kinetic and kinematic variables, ten Vicon cameras and a force plate were used. Foot segment velocity(FSV), vertical ground reaction force(GRF), impulse, ground time(GT) in phase 1, trunk angular velocity(TAV), vertical center of gravity(COG), flight time(FT) in phase 2 and kicking leg segment velocity(KSV) in phase 3 were measured and analyzed. Results indicated that there were similar patterns of variables among phases between subjects. Non-significant correlation(r=.145) between flight time(FT) and impulse was found. Also non-significant correlation(r=.119) between center of gravity(COG) and impulse was found. In conclusions, there were similar strategies in phase 1, phase 2, and phase 3 between subjects.

• Restorative Dentistry and Endodontics
• /
• v.29 no.5
• /
• pp.446-453
• /
• 2004

The aim of this study was to evaluate the shaping abilities of four different rotary nickel-titanium instruments with anticurvature motion to prepare root canal at danger zone by measuring the change of dentin thickness in order to have techniques of safe preparation of canals with nickel-titanium files. Mesiobuccal and mesiolingual canals of forty mesial roots of extracted human lower molars were instrumented using the crown-down technique with ProFile, $GT^{TM}$ Rotary file, Quantec file and $ProTaper^{TM}$. In each root, one canal was prepared with a straight up-and-down motion and the other canal was with an anticurvature motion. Canals were instrumented until apical foramens were up to size of 30 by one operator. The muffle system was used to evaluate the root canal preparation. After superimposing the pre- and post-instrumentation canal. change in root dentin thickness was measured at the inner and outer sides of the canal at 1. 3, and 5 mm levels from the furcation. Data were analyzed using two-way ANOVA. Root dentin thickness at danger zone was significantly thinner than that at safe zone at all levels (p < 0.05). There was no significant difference in the change of root dentin thickness between the straight up-and-down and the anticurvature motions at both danger and safe zones in all groups (p > 0.05). ProTaper removed significantly more dentin than other files especially at furcal 3 mm level of danger and safe zones (p < 0.05) Therefore, it was concluded that anticurvature motion with nickel-titanium rotary instruments does not seem to be effective in danger zone of lower molars.

• The Korean Journal of Mycology
• /
• v.41 no.1
• /
• pp.14-20
• /
• 2013

We already reported four groups which contains some similar strains based on URP-PCR in the previous paper. The objective of this study was to confirm those strains by the amplified fragment length polymorphism (AFLP) and vegetative compatibility group (VCG). AFLP analysis showed no difference among these strains except ASI 2595 and 2183 in Weonhyeong group and ASI 2829 in Suhan group. They showed specific DNA bands only in the result of P + AG/M + AAG and P + GT/M + ATG primer combinations out of eight different combinations. The AFLP primers produced a total of 330 fragments between 80 and 1000 bp in length for 31 Pleurotus ostreatus strains. At a genetic similarity of 0.96, the UPGMA analysis separated the isolates into four distinct clusters. Each group was classified by similar strains. Confrontation test by vegetative compatibility groups (VCGs) also showed distinct line between strains from different groups, but no line between similar strains within the cluster. Our results indicate that most of similar strains was not distinctness. Thus, similar strains are considered to be very close on the genealogy of their parent or same strain with different name.