• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.1
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• pp.105-115
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• 2014

A numerical analysis on the smoke behavior and evacuee safety has been performed with computational fluid dynamics. The purpose of this study is to build computational processes for an evacuation and prevention of a fire disaster of a 3 km-length tunnel in Korea. To save computational cost, 1.5 km of the tunnel that can include a few cross-passing tunnels is considered. We are going to assess the fire safety in a road tunnel according to the smoke level, which consists of the smoke density and the height from the floor. The smoke density is obtained in detail from three-dimensional unsteady CFD analysis. To obtain proper temperature distributions on the tunnel wall, one-dimensional conduction equation is considered instead of an adiabatic wall boundary or a constant heat flux. The tunnel considered in this study equips the cross passing tunnels for evacuees every 250 m. The distance is critical in both safety and economy. The more cross passing tunnels, the more safe but the more expensive. Three different jet fan operations can be considered in this study; under- and over-critical velocities for normal traffic condition and 0-velocoty operation for the traffic congestion. The SE (smoke environment) level maps show a smoke environment and an evacuating behavior every moment.

• Fisheries and Aquatic Sciences
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• v.5 no.3
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• pp.229-234
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• 2002

Possibility of raising sunshine bass during the winter season in Korea was investigated. Also, the effect of feed on growth and body composition of sunshine bass was compared at the various salinity. Twenty sunshine bass $(Mean\;weight\;\pm S.D.\: :\;53.9 \pm 0.24 g)$ were stocked into the eighteen circular flow-through tanks. A 2 (feed) $\times$ 3 (salinity) factorial design with triplicate was used for this study. Feed was prepared into the 2 groups: the raw fish-based me>ist pellet (MP) containing $59.5\%$ crude protein and $9.4\%$ crude lipid, and commercial sinking red sea bream feed (CF) containing $49.9\%$ crude protein and $9.4\%$ crude lipid, respectively. And salinity was prepared into the 3 groups: freshwater $(0\%)$, brackishwater $(15\%)$, and seawater $(32\%)$. Fish were fed to satiation twice daily for 6 days a week. Fish were all survived at the end of the 8-week feeding trial. Weight gain (WG) and specific growth rate (SGR) of sunshine bass were significantly (P<0.05) affected by both feed and salinity. WG and SGR of sunshine bass fed the MP were significantly (P<0.05) higher than those of fish fed the CF in the same salinity. Amount of dry feed fed was significantly (P<0.05) affected by both feed and salinity. Feed consumption by sunshine bass fed on the MP was significantly (P<0,05) higher than by fish fed on the CF in the same salinity. Feed efficiency ratio (FER) was significantly (P<0,05) affected by salinity, but not by feed. Protein efficiency ratio (PER) was significantly (P<0.05) affected by both feed and salinity. Moisture and protein content of the whole-body of fish was not significantly (P>0.05) affected by either feed or salinity. However, lipid and ash content of the whole-body of fish was significantly (P<0.05) affected by salinity, but not by feed. In conclusion, the MP was superior to CF for growth of sunshine bass during the winter season in Korea and no mortality occurred. And sunshine bass seemed to grow better in freshwater $(0\%)$ and brac-kishwater $(15\%)$ than seawater $(32\%)$ under these experimental conditions, in terms of improvement in FER and PER in freshwater or brackishwater.

• YAKHAK HOEJI
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• v.51 no.2
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• pp.133-139
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• 2007

A simple and sensitive HPLC-MS method for quantitation of 10${\alpha}$-methoxy-9,10-dihydrolysergol (MDL), the main metabolite of nicergoline, in human plasma was developed and the bioavailability parameters of MDL was assessed in Korean healthy male volunteers. Clomipramine was used as an internal standard. MDL and internal standard in plasma sample were extracted using ethyl acetate. A centrifuged upper layer was then evaporated and reconstituted with mobile phase of 10 mM ammonium acetate-acetonitrile (10 : 90, v/v). The reconstituted samples were injected into a Zorbax SB-C8 column (2.1${\times}$150 mm,5 ${\mu}$m) at a flow-rate of 0.3 ml/min. Using MS with selected ion monitoring (SIM) mode, MDL and clomipramine were detected without severe interference from human plasma matrix. MDL produced a protonated molecular ion ([M+H]$^+$) at m/z 287. Internal standard produced a protonated molecular ion ([M+H]$^+$) at m/z 315. A linear relationship for MDL was found in the range of 2.5${\sim}$100 ng/ml. The lower limit of quantitation (LLOQ) was 2.5 ng/ml with acceptable precision and accuracy. The intra- and inter-day validation for all coefficients of variation (R.S.D.%) were found less than 15%. Main pharmacokinetic parameters of 30 mg of nicergoline were revealed as follows: AUC$_t$ 321.1${\pm}$64.5 ng${\cdot}$hr/ml, C$_{max}$, 51.2${\pm}$25.3 ng/ml, T$_{max}$ 3.6${\pm}$1.5 hr, K$_{el}$ 0.12${\pm}$0.07 hr$^{-1}$ and t$_{1/2}$ 7.6${\pm}$3.4 hr. Inter subject variations and race differences were shown in comparison with the published data in the literature.

• Journal of Korean Society of Transportation
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• v.35 no.3
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• pp.220-233
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• 2017

Traffic volumes are fundamental data widely used in various traffic analysis, such as origin-and-destination establishment, total traveled kilometer distance calculation, congestion evaluation, and so on. The low number of links collecting the traffic-volume data in a large urban highway network has weakened the quality of the analyses in practice. This study proposes a method to estimate the traffic volume data on a highway link where no collection device is available by introducing a spatial statistic technique with (1) the traffic-volume data from TOPIS, and National Transport Information Center in the Ministry of Land, Infrastructure, and (2) the navigation data from private navigation. Two different component models were prepared for the interrupted and the uninterrupted flows respectively, due to their different traffic-flow characteristics: the piecewise constant function and the regression kriging. The comparison of the traffic volumes estimated by the proposed method against the ones counted in the field showed that the level of error includes 6.26% in MAPE and 5,410 in RMSE, and thus the prediction error is 20.3% in MAPE.

• The Journal of Internal Korean Medicine
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• v.30 no.1
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• pp.107-118
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• 2009

Objectives : This study was aimed to investigated the effect of Yijin-tang on gastric motility and its mechanism of action in normal intact and partial pyloric obstructed rats. Methods : Gastric emptying was measured by the number of glass beads expelled from the stomach (containing one hundred of glass beads. ${\phi}1mm$) in 1 hour or 2 hours after glass beads and test drugs (normal saline. Yijin-tang 90mg/kg. Yijin-tang 270mg/kg) administration in normal intact and partial pyloric obstructed rats. In another series of experiments to evaluate the mechanism of Yijin-tang 270mg/kg under delayed conditions, normal intact rats were treated with atropine sulfate (1mg/kg,s.c.), cisplatin (10mg/kg,i.p.), quinpirole HCI (0.3mg/kg,i.p.) and NAME (NG-nitro-L-arginine methyl ester. 75mg/ kg,s.c.), respectively. Partial pyloric obstructed rats were modified by wrapping the nonabsorbable rubber ring (D :6mm, W:4mm, T: 1mm) around the 1st portion of the duodenum for 8 weeks. The myoelectrical activity of the gastric smooth muscle was recorded by a bipolar electrode placed at the abdominal surface in normal intact and partial pyloric obstructed rats. The gastric myoelectrical activity was measured for 30 minutes before and after orogastric administration of each solution (normal saline, Yijin-tang 270mg/kg) and expressed as dominant frequency, percent of normogastria and power ratio. Results : Yijin-tang improved gastric emptying more than normal saline in normal intact(p<0.001) and partial pyloric obstructed rats(p=0.002). Under the delayed gastric emptying induced by atropine sulfate, cisplatin, quinpirole HCI and NAME. Yijin-tang enhanced gastric emptying significantly in the cisplatin treated group(p<0.001). but didn't in other treated groups. Administration of Yijin-tang 270mg/kg has no significant effect on the myoelectrical activity of the gastric smooth muscle in both normal intact rats and partial pyloric obstructed rats. Conclusions : Yijin-tang seems to stimulate the gastric motility through suppressing the 5HT3 receptor and promoting the antroduodenal flow. We expect that Yijin-tang would be effective especially in dysmotility-like functional dyspepsia with partial pyloric obstruction or the side effects of cisplatin such as nausea, vomiting, abdominal discomfort, and delay of gastric emptying.

• Journal of Plant Biotechnology
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• v.50
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• pp.19-26
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• 2023

Korean ginseng (Panax ginseng Meyer) is an economically important plant because of it is rich in saponins. It is mainly cultivated in Asia, including Korea and China. Since ginseng requires a long breeding period due to juvenility, homozygote production techniques, such as anther culture, must be urgently established. In the present study, callus induction and embryogenesis through anther culture were observed in P. ginseng. Murashige and Skoog medium was used as the basal medium suitable for callus induction. When the medium was supplemented with 3% sucrose, the callus induction rate was high and the callus size was large. Cold pretreatment did not significantly affect callus induction and embryogenesis. Embryogenesis was the most efficient when the embryo-formation medium was supplemented with 1.0 or 3.0 mg/L 2,4-dichlorophenoxyacetic acid. Cultivar significantly affected anther culture efficiency. Specifically, 'Cheongseon' showed the highest embryo-formation efficiency, whereas no embryogenesis occurred in 'Sunun'. Ploidy assessment revealed the haploid status of the induced calli. Embryos derived from anther culture formed shoots upon transfer to germination medium, although no difference in ploidy was noted between the induced callus and control. Overall, the anther culture conditions established in the present study may contribute to the production of homozygous P. ginseng plants in the future.

• The Journal of Korean Medicine
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• v.44 no.4
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• pp.87-103
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• 2023

Backgrounds and objectives: Cardiotonic Pills^® (CP) are used for vascular diseases such as coronary diseases, atherosclerosis, and cerebral infarction. This study aimed to determine the transient effects of CP on cerebrovascular CO₂ reactivity (CVR) and erythrocyte deformability in normal subjects. Methods: This study had a crossover design and included 10 participants who were randomly allocated to 2 groups. The experimental group was given CP with water, while the control group was given only water. CVR was measured by hyperventilation-induced CVR of the middle cerebral artery (MCA) using transcranial Doppler (TCD). Erythrocyte deformability was measured using a Rheoscan-D microfluidic ektacytometer. All measurements were performed prior to and 1, 2, and 3 hours after CP or water administration. Blood pressure and heart rate were also measured before and after administration. Results: CP significantly improved CVR 3 hours after administration in the experimental group compared to the control group (p = 0.042). The corrected blood flow velocity at partial pressure of end-tidal carbon dioxide (PETCO₂) = 40mmHg (CV40) was also significantly improved 2 and 3 hours after administration in the CP group compared to the control group (p = 0.036 and p = 0.021, respectively). CP significantly improved erythrocyte deformability 3 hours after administration in the experimental group compared to the control group (p = 0.027). Mean heart rate and mean blood pressure showed no change. Conclusions: This study demonstrated that CP increases CVR and erythrocyte deformability. These results suggested that CP improves cerebral microcirculation which provide evidence for the future use of CP for prevention of ischemic stroke and neurodegenerative diseases.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7849-7855
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• 2014

Purpose: To investigate the effect of deacetylase inhibitory trichostatin A (TSA) on anti HepG2 liver carcinoma cells and explore the underlying mechanisms. Materials and Methods: HepG2 cells exposed to different concentrations of TSA for 24, 48, or 72h were examined for cell growth inhibition using CCK8, changes in cell cycle distribution with flow cytometry, cell apoptosis with annexin V-FTIC/PI double staining, and cell morphology changes under an inverted microscope. Expression of ${\beta}$-catenin, HDAC1, HDAC3, H3K9, CyclinD1 and Bax proteins was tested by Western blotting. Gene expression for ${\beta}$-catenin, HDAC1and HDAC3 was tested by q-PCR. ${\beta}$-catenin and H3K9 proteins were also tested by immunofluorescence. Activity of Renilla luciferase (pTCF/LEF-luc) was assessed using the Luciferase Reporter Assay system reagent. The activity of total HDACs was detected with a HDACs colorimetric kit. Results: Exposure to TSA caused significant dose-and time-dependent inhibition of HepG2 cell proliferation (p<0.05) and resulted in increased cell percentages in G0/G1 and G2/M phases and decrease in the S phase. The apoptotic index in the control group was $6.22{\pm}0.25%$, which increased to $7.17{\pm}0.20%$ and $18.1{\pm}0.42%$ in the treatment group. Exposure to 250 and 500nmol/L TSA also caused cell morphology changes with numerous floating cells. Expression of ${\beta}$-catenin, H3K9and Bax proteins was significantly increased, expression levels of CyclinD1, HDAC1, HDAC3 were decreased. Expression of ${\beta}$-catenin at the genetic level was significantly increased, with no significant difference in HDAC1and HDAC3 genes. In the cytoplasm, expression of ${\beta}$-catenin fluorescence protein was not obvious changed and in the nucleus, small amounts of green fluorescence were observed. H3K9 fluorescence protein were increased. Expression levels of the transcription factor TCF werealso increased in HepG2 cells following induction by TSA, whikle the activity of total HDACs was decreased. Conclusions: TSA inhibits HDAC activity, promotes histone acetylation, and activates Wnt/${\beta}$-catenin signaling to inhibit proliferation of HepG2 cell, arrest cell cycling and induce apoptosis.

• Journal of Chest Surgery
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• v.31 no.7
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• pp.674-678
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• 1998

The conventional surgical treatment of isolated critical stenosis of the left main coronary artery restores a less physiologic perfusion of the myocardium, leads to occlusion of the left coronary ostium, and consumes an appreciable length of bypass material. From June 1994 to February 1996, eleven patients, three male and eight female, underwent patch angioplasty and additional bypass graft to left anterior descending artery (10 internal mammary artery, 1 saphenous vein) in isolated critical left main coronary artery stenosis. Their ages ranged from 34 to 62 years, mean 44 years. All had 60% to 90% stenosis of the left main coronary artery and Class III angina. The angiogram showed nine osteal lesion and three main stem stenosis. The operation was performed with conventional cardiopulmonary bypass and cold blood cardioplegia. We approached anteriorly and used bovine pericardium as onlay patch in all patients. There were one leg wound dehiscence, but no operative deaths and infarctions. All patients are free of symptoms after a mean follow-up of 15.5 months. Angiographic restudy at an average 14.4 months was obtained in five patients and showed widely patent left main coronary artery with excellent runoff. But additional graft to left anterior descending coronary artery were stenosed in two patients and showed diminutive flow in others. Our preliminary results suggest that angioplasty of the left main coronary artery can be carried out with low operative risks. But additional bypass graft to left anterior descending coronary artery may be unnecessary. The technique appears to be a promising alternative to conventional coronary artery bypass grafting in isolated left main coronary artery stenosis.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.2
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• pp.85-94
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• 1997

The study is aimed to find out the causes of rapidly increasing chloride (Cl$^{－}$) concentration of the Samyang 3rd pumping station originated from coastal springs of Cheju since January 1996. The study results show that it was caused by following complicated natural and anthropogenic effects. Due to severe draught in 1996 with total rainfall of only 41.7% of annual mean of the last 36 years (1991 to 1995), it creates firstly), significant decrease of the spring discharges as well decline of the groundwater level at the site . Sea water level was in general 4.4 cm to 12.4 cm higher than the groundwater level of the site during 2 to 3.8 hours at each high tide. Those higher potential head of sea water motivates the sea water intrusion into the fresh water lens through the permeable clinkers and fracture zones situated beneath the existing grouted zone which was installed to a maximum 10 m below the ground water surface, The repeated expansion and contraction of the fresh water lens occurred by periodic changes of the sea water level at high and low tide accelerates secondly the enlargement of the transition zone between the fresh and sea water at the site. The decrease of recharge amount by rainfall shortage creates thirdly the reverse flow at the interface of sea water and groundwater. The repeated groundwater extraction of 2790${\pm}$450 $m^3$d$^{－1}$ at the time of low tide, when the fresh water lens of the sire is under the contraction stare, makes additional drawdown of the ground water level and induces the upconing of salt water into the fresh water lens. The duration of spring discharge whose Cl concentration is less than 150 mg/1 at the low tide measured at the nearby springs was about two hours with discharge rate of 532 $m^3$d$^{－1}$ and after that Cl$^{－}$ concentration is increased up to more than 1900 mg/ι.eased up to more than 1900 mg/L.