• Economic and Environmental Geology
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• v.32 no.4
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• pp.385-398
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• 1999

The Narim gold mine is located approimately 200km southeast of Seoul within the Muju mineralized district of the Sobaegsan gneiss complex, Korea. Environmental geochemistry were undertaken for various kinds of water (surface, ground and mine water) collected of April, September and November in 1998 from the narim mine creek. Hydrogeochemical compositions of water samples are characterized by the relatively significant enrichment of Na+K, alkali ions, $HCO_{3}$, $NO_{3}$, Cl and F in groundwater, wheras the mine and surface waters are relatively enriched in Ca+Mg, hea표 metals and $SO_{4}$. Therefore, the groundwaters belong to the (Na+Ca)-( $HCO_{3}+SO_{4}$) type, respectively. The pH and EC values of the non-mining creek surfers are relatively lower compared with those of the surface water of the mine and ore dump area. The d values ($\delta$D-8$\delta^{18}$O) of all kinds of water from the Narim mine creek are 5.8 to 13.1 The range of $\delta$D and $\delta^{18}$O values (relative to SMOW) are shown in distinct two groups as follows: for the April waters of -64.8 to -67.8$\textperthousand$ and -9.6 to -10.0$\textperthousand$(d value=10.1 to 13.1), and for the November waters of -65.9 to -70.2$\textperthousand$ and -9.3 to -9.6$\textperthousand$ (d value=5.8 to 7.9), respectively. This range variation indicates that two group water were composed of distinct waters with seasonal difference. Geochemical modeling showed that mostly toxic metals (As, Fe, Mn, Ni, Pb, Zn) may exist largery in the from of metal $(M2^+)$ and metal-sulfate $(MSO_4\;^{2-$\mid$),\; and \;SO_4^{2-$\mid$}$ concentration influenced the speciation of heavy metals in the meteoric water. These metals in the groundwater could be formed of $CO_3 \;and \;(OH)_3$ complex ions. Using computer program, saturation index of albite, calcite, dolomite in meteoric water show undersaturated and progreddively evolved toward the saturation state, however, ground and mine water are nearly saturated. The gibbsited water-mineral reaction and stabilities suggest that the weathering of silicate minerals may be stable kaolinite, illite and Nasmectite. The clay minerals will be transformed to more stable kaolinite owing to the contiunous reaction.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.5
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• pp.543-553
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• 2010

Almost five million citizens a day are using subways as a means of traffic communication in the Seoul metropolitan. As the subway system is typically a closed environment, indoor air pollution problems frequently occurs and passengers complain of mal-health impact. Especially $PM_{10}$ is well known as one of the major pollutants in subway indoor environments. The purpose of this study was to compare the indoor air quality in terms of $PM_{10}$ and to quantitatively compare its source contributions in a Seoul subway platform before and after installing platform screen doors (PSD). $PM_{10}$ samples were collected on the J station platform of Subway Line 7 in Seoul metropolitan area from Jun. 12, 2008 to Jan. 12, 2009. The samples collected on membrane filters using $PM_{10}$ mini-volume portable samplers were then analyzed for trace metals and soluble ions. A total of 18 chemical species (Ba, Mn, Cr, Cd, Si, Fe, Ni, Al, Cu, Pb, Ti, $Na^+$, $NH_4^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, and ${SO_4}^{2-}$) were analyzed by using an ICP-AES and an IC after performing proper pre-treatments of each sample filter. Based on the chemical information, positive matrix factorization (PMF) model was applied to identify the source of particulate matters. $PM_{10}$ for the station was characterized by three sources such as ferrous related source, soil and road dust related source, and fine secondary aerosol source. After installing PSD, the average $PM_{10}$ concentration was decreased by 20.5% during the study periods. Especially the contribution of the ferrous related source emitted during train service in a tunnel route was decreased from 59.1% to 43.8% since both platform and tunnel areas were completely blocked by screen doors. However, the contribution of the fine secondary aerosol source emitted from various outside combustion activities was increased from 14.8% to 29.9% presumably due to ill-managed ventilation system and confined platform space.

• The Journal of Internal Korean Medicine
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• v.31 no.4
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• pp.857-869
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• 2010

Objectives : The aim of this study was to evaluate whether rats with non-obstructive antral dilation could be a useful tool resembling functional dyspeptic patients. We also investigated the effect of Bojoongikki-tang (BJ), and Youngkaechulgam-tang (YK) in antral dilated rats. Methods : Non-obstructive antral dilation was performed by first wrapping a non-absorbable rubber ring (D:6mm, W:4mm, T:1mm) around the 1st portion of the duodenum causing pyloric obstruction (PO). After 12 weeks, except for some PO group rats used for the control, the rubber ring was removed by performing another operation. The antral dilated rats (AD) were then divided into three groups, a non-treatment group (AD-NT), and two herbal medicine groups each given an extract solution containing 125 mg/kg of Youngkaechulgam-tang (AD-YK) or Bojoongikki-tang (AD-BJ) for 4 weeks. Then gastric contractility was evaluated by bowel sound measurement, and afterwards the changes of the weight, and morphologic changes of the stomach were evaluated for each group including the normal intact group (NI). Results : Loss of weight and enlargement of the stomach surface area was seen in the PO group. Decrease of gastric motility index was observed in the AD-NT group, while the increased surface area of the stomach was not significantly different from the PO group. Youngkaechulgam-tang seemed to increase gastric contraction, whereas Bojoongikki-tang showed no effect. Weight gain of rats was observed in both the AD-YK and AD-BJ groups, but there seemed to be no change of the dilated stomach surface area. Conclusions : The non-obstructive antral dilated rat seems to be an experimental pathologic model that reflects the gastric dysmotility similar to functional dyspeptic patients with antral dilation. Therefore patients with dysmotility-like dyspepsia with antral function disorders should be treated efficiently. As Youngkaechulgam-tang is shown to increase both gastric contraction and weight in antral dilated rats, it may be used for treating functional dyspepsia. However, Bojoongikki-tang should be used with caution in patients with gastric dysmotility.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.1 no.1
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• pp.89-99
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• 1991

The metal concentrations in lungs from 12 coal workers' pneumoconiosis(CWP) patients and 6 controls, who were not exposed occupationally to coal mine dust and metals during their life time, were analyzed by atomic absorption spectrophotometry. 1. Copper, lead, nickel, magnesium, manganese, zinc and iron concentrations in lungs of CWP patients were $1.10{\pm}0.088$, $1.12{\pm}0.068$, $0.22{\pm}0.020$, $113.7{\pm}1.31$, $0.19{\pm}0.012$, $10.2{\pm}1.54$, $426.7{\pm}2.63{\mu}g/g$ wet weight. 2. Copper, lead, nickel, magnesium, manganese, zinc and iron concentrations in lungs of controls were $1.10{\pm}0.013$, $0.85{\pm}0.007$, $0.10{\pm}0.008$, $87.6{\pm}1.29$, $0.18{\pm}0.005$, $10.6{\pm}1.44$, $164.9{\pm}3.29{\mu}g/g$ wet weight. 3. The ratios of concentrations for copper, lead, nickel, magnesium, manganese, zinc, and iron in lungs for CWP patients and controls were 1 : 1, 1.32 : 1, 2.20 : 1, 1.30 : 1, 1.06 : 1, 0.92 : 1, 2.58 : 1, respectively. There were significant differences in concentrations of lead, nickel, magnesium, iron by group(p<0.05). 4. There was no significant difference in metal concentrations of right upper lobe, right lower lobe, left upper lobe and left lower lobe for both CWP patients and controls (p>0.05, p>0.05). 5. In CWP patients lead was well correlated with nickel showing a rank correlation coefficient of 0.533, and zinc was correlated with copper showing a rank correlation coefficient of 0.476. 6. The concentrations of copper, nickel, maganese, and zinc in Korean CWP patients were lower than those in foreign CWP patients.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.4
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• pp.439-454
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• 2008

The purpose of this study was to extensively identify $PM_{10}$ sources and to estimate their contributions to the study area, based on the analysis of the $PM_{10}$ mass concentration and the associated inorganic elements, ions, and total carbon. The contribution of $PM_{10}$ sources was estimated by applying a receptor method because identifying air emission sources were effective way to control the ambient air quality. $PM_{10}$ particles were collected from May to November 2007 in the Yongin-Suwon bordering area. $PM_{10}$ samples were collected on quartz filters by a $PM_{10}$ high-volume air sampler. The inorganic elements (Al, Mn, V, Cr, Fe, Ni, Cu, Zn, Cd, Pb, Si, Ba, Ti and Ag) were analyzed by an ICP-AES after proper pre-treatments of each sample. The ionic components of these $PM_{10}$ samples ($Cl^_$, $NO_3^-$, $SO_4^{2-}$, $Na^+$, $NH_4^+$, $K^+$, $Ca^{2+}$, and $Mg^{2+}$) were analyzed by an IC. The carbon components (OC1, OC2, OC3, OC4, OP, EC1, EC2 and EC3) were also analyzed by DRI/OGC analyzer. Source apportionment of $PM_{10}$ was performed using a positive matrix factorization (PMF) model. After performing PMF modeling, a total of 8 sources were identified and their contribution were estimated. Contributions from each emission source were as follows: 13.8% from oil combustion and industrial related source, 25.4% from soil source, 22.1% from secondary sulfate, 12.3% from secondary nitrate, 17.7% from auto emission including diesel (12.1%) and gasoline (5.6%), 3.1% from waste incineration and 5.6% from Na-rich source. This study provides information on the major sources affecting air quality in the receptor site, and therefore it will help us maintain and manage the ambient air quality in the Yongin-Suwon bordering area by establishing reliable control strategies for the related sources.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.606-612
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• 2018

The enzyme xylose isomerase (E.C. 5.3.1.5, XI) is responsible for the conversion of an aldose to ketose, especially xylose to xylulose. Owing to the ability of XI to isomerize glucose to fructose, this enzyme is used in the food industry to prepare high-fructose corn syrup. Therefore, we studied the characteristics of XI from Anoxybacillus kamchatkensis G10, a thermophilic bacterium. First, the gene coding for XI (xylA) was inserted into the pET-21a(+) expression vector and the construct was transformed into the Escherichia coli competent cell BL21 (DE3). The expression of recombinant XI was induced in the absence of isopropyl-thio-${\beta}$-galactopyranoside and purified using Ni-NTA affinity chromatography. The optimum temperature of recombinant XI was $80^{\circ}C$ and measurement of the heat stability indicated that 55% of residual activity was maintained after 2 h incubation at $60^{\circ}C$. The optimum pH was found to be 7.5 in sodium phosphate buffer. Magnesium, manganese, and cobalt ions were found to increase the enzyme activity; manganese was the most effective. Additionally, recombinant XI was resistant to the presence of $Ca^{2+}$ and $Zn^{2+}$ ions. The kinetic properties, $K_m$ and $V_{max}$, were calculated as 81.44 mM and $2.237{\mu}mol/min/mg$, respectively. Through redundancy analysis, XI of A. kamchatkensis G10 was classified into a family containing type II XIs produced by the genera Geobacillus, Bacillus, and Thermotoga. These results suggested that the thermostable nature of XI of A. kamchatkensis G10 may be advantageous in industrial applications and food processing.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.1
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• pp.74-85
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• 2013

Since the underground transportation system is a closed environment, indoor air quality problems may seriously affect many passengers' health. The purpose of this study was to understand $PM_{10}$ characteristics in the underground air environment and further to quantitatively estimate $PM_{10}$ source contributions in a Seoul Metropolitan subway station. The $PM_{10}$ was intensively collected on various filters with $PM_{10}$ aerosol samplers to obtain sufficient samples for its chemical analysis. Sampling was carried out in the M station on the Line-4 from April 21 to 28, July 13 to 21, and October 11 to 19 in the year of 2010 and January 11 to 17 in the year of 2011. The aerosol filter samples were then analyzed for metals, water soluble ions, and carbon components. The 29 chemical species (OC1, OC2, OC3, OC4, CC, PC, EC, Ag, Al, Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Si, Ti, V, Zn, $Cl^-$, $NO_3{^-}$, $SO_4{^{2-}}$, $Na^+$, $NH_4{^+}$, $K^+$, $Mg^{2+}$, $Ca^{2+}$) were analyzed by using ICP-AES, IC, and TOR after proper pretreatments of each sample filter. Based on the chemical information, positive matrix factorization (PMF) model was applied to identify the $PM_{10}$ sources and then six sources such as biomass burning, outdoor, vehicle, soil and road dust, secondary aerosol, ferrous, and brakewear related source were classified. The contributions rate of their sources in tunnel are 4.0%, 5.8%, 1.6%, 17.9%, 13.8% and 56.9% in order.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.23 no.3
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• pp.154-160
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• 2012

Objectives : The purpose of this study was to investigate clinical characteristics of children and adolescents with autism spectrum disorders (ASDs) using methylphenidate (MPH). Methods : Retrospective review of the charts of 79 children and adolescents with ASDs, who visited the Department of Child and Adolescent Psychiatry of Seoul National Hospital, from July 2010 to July 2011, was conducted. Changes in illness severity and improvement were measured using the Clinical Global Impression-Severity of illness (CGI-S) and Clinical Global Impression-Improvement (CGI-I) Scales. Results : We found that MPH was prescribed in 23 (29.1%) children and adolescents. Of the 23 patients on MPH, 4 patients (17.4%) were on MPH monotherapy and 18 patients (78.3%) were using risperidone concomitantly. MPH was prescribed primarily for symptoms of hyperactivity and impulsivity in ASDs patients. The mean dosage of MPH was $26.2{\pm}11.1$mg/day and mean duration of treatment was $31.9{\pm}28.7$ months. Mean CGI-S score improved significantly from baseline to endpoint (from $5.4{\pm}0.6$ to $4.1{\pm}0.9$ ; p<.01). MPH was reported to be effective in 17 patients (17/23, 73.9%), and 10 patients (10/23, 43.5%) reported side effects. Side effects included decreased appetite (4/23, 17.4%), tic (2/23, 8.6%), sleep disturbances (2/23, 8.6%), headache (1/23, 4.3%) and irritability (1/23, 4.3%). Conclusion : The results of this study demonstrate that MPH may be used effectively and safely in children and adolescents with ASDs with hyperactivity and impulsivity. Future controlled trials are needed to confirm these findings.

• Journal of Environmental Health Sciences
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• v.43 no.3
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• pp.233-239
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• 2017

Objectives: The pollution status of heavy metals within the soil was investigated with an aim to establishing a sustainable soil environment within parks and amusement facilities installed in urban areas of Gyeonggi-do Province. Methods: As sampling sites, 14 locations were selected from a city with a number of factories near a residential area, a residential area, and a children's park in a city with mixed green areas. Seven kinds of heavy metals, including Cd, Pb, and Hg, and the pH of soil were analyzed three times by inductively coupled plasma optical emission spectroscopy (ICP-OES) and atomic absorption spectrometer (AAS). Results: In this study, the pH of the samples from the residential park and industrial park showed 5.7-6.5 and 5.9-7.0, respectively. The overall mean concentration (mg/kg) of heavy metals was Zn (132.8), Ni (73.0), Cu (47.4), Pb (35.9), As (4.84), Cd (0.39), and Hg (0.07), indicating that these concentrations of heavy metals were lower than those for the area 1 standard of soil pollution concern criteria. In addition, the sampling sites in the residential area and the industrial area also showed the same tendency for concentration distribution. Conclusions: We found that the soil pollution class (SPC) of some spots were over 200, which are third and fourth classes. In order to manage a sustainable soil environment in a city park, it is suggested that local governments, the management bodies for these parks, need to manage, supervise, and investigate soil pollution and quickly replace contaminated soil.

• Journal of Soil and Groundwater Environment
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• v.17 no.3
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• pp.1-9
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• 2012

According to the agreement on WTO/TBT, we are under the situation to adopt international standard (ISO standard) as a national standard if it exists. However, in case of environmental area, it is a domestic legal obligation to use Korean environmental standard method(KESM) for analyzing various contaminants. Therefore it is necessary to assess the comparability between KEM and ISO standard prior to apply ISO standard to soil conservation law in Korea. The main purpose of this study is to assess the comparability of both methods for analyzing heavy metals in soil. We looked over various aspects like pre-treatment, calibration curve range, detection wavelength, soil organic matter content and so on. Apparently, the procedure of both methods is almost same. However in details, both methods are different in stationary time before aqua-regia extraction using reflux system, calibration curve range for Cu, Pb, Ni and measuring wavelength for Pb. According to the results of comparison test, the results were significantly different when the different calibration range was used. In case that all the extracts independent of methods were reanalyzed with the same calibration range of each method, both methods showed statistically same results. Other conditions like different stationary time, measuring wavelength of AAS and soil organic matter content did not have any influence on the analytical result. Therefore, we suggest to extend the calibration curve range to 0~8 mg/L which is used in KS I ISO standard(Korean standard related with environment which is translation version of ISO standard without any technical change). In case of $Cr^{6+}$, the results showed no significant differences between two methods even though the pretreatment, instrumentation and other analysis conditions were different. In addition to UV/Visble spectrometry of KESM for soil contamination, we suggest to adopt ion chromatography of ISO 15192(US EPA method 7199) for analyzing $Cr^{6+}$ with the consideration of laboratory work efficiency.